Method and device for producing sic solid material

Abstract

To provide a method for producing a preferably elongated SiC solid, in particular of polytype 3C.SOLUTION: The method according to the invention preferably includes at least the following steps: introducing at least a first source gas into a process chamber, said first source gas including Si, introducing at least one second source gas into the process chamber, the second source gas including C, electrically energizing at least one separator element disposed in the process chamber to heat the separator element, setting a deposition rate of more than 200 μm / h, where a pressure in the process chamber of more than 1 bar is generated by the introduction of the first source gas and / or the second source gas, and where the surface of the deposition element is heated to a temperature in the range between 1300°C. and 1800°C.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method for the production of at least one SiC crystal, in particular a SiC single crystal, according to claim 1, to a SiC crystal according to claim 35, and to a system according to claim 41.

Background Art

[0002] Power electronic devices based on silicon carbide (SiC) wafers exhibit improved performance over those based on conventional silicon (Si) wafers mainly due to the wider bandgap of SiC which enables it to operate at higher voltages, temperatures, and frequencies. With the growing global shift towards electric vehicles (EVs), interest in high-performance SiC-based power electronic devices is increasing steadily, but SiC wafers remain considerably more expensive than Si wafers.

[0003] Currently, the dominant method for the commercial production of SiC single crystals is physical vapor transport (PVT).

[0004] At present, the industrial SiC source materials used are produced through the commercial Acheson process and are then further purified by pulverization and acid leaching. The Acheson process remains the only known process for the production of SiC source materials on an industrial scale. Acid leaching is used to extract trace metals from SiC but only penetrates to a depth of less than about 1 micron from the surface of the particles. That is, the particles need to be small enough such that this penetration layer constitutes a sufficient proportion of the total volume of the particles. As a result, the powdered SiC particles typically need to have an average particle size of 200 - 300 microns. At this average particle size, this material can only be purified up to about 99.99% or 99.999%, also known as 4N or 5N purity respectively.

[0005] In some cases, silicon powder that has been mixed with graphite powder and sintered is used to produce the SiC source material. Powdering the SiC material creates a large surface area for contamination during handling and exposure to air. The main contaminants of concern are trace metals, nitrogen, and oxygen.

[0006] Despite these acid-leached or sintered SiC materials having only moderate 4N or 5N purity, they are expensive and significantly contribute to the overall high cost of the resulting SiC wafers. The moderate purity also contributes to high wafer costs in that impurities cause defects within the crystal, which then have to be discarded rather than sliced into wafers. In other words, impurities in the source material contribute to low crystal yields.

[0007] The presence of trace metals in the SiC source material is thought to be the main root cause of crystal defects in the resulting single-crystalline SiC boules grown by PVT. Currently, the quality of single-crystalline SiC boules with respect to crystal defects such as dislocations is several orders of magnitude lower than that of other semiconductor crystals such as silicon or GaAs. These crystal defects lead to unwanted electrical short circuits within SiC electrical devices (mostly vertical devices in most cases) and reduce the electrical device yield. Therefore, it is essential to find a better solution to prevent crystal defects resulting from source material impurities.

[0008] Furthermore, metal impurities in SiC wafers manufactured from single-crystalline SiC boules interact with subsequent implant and doping technologies for manufacturing SiC electrical devices, which is thought to potentially lead to device failures and reduce the electrical device yield.

[0009] Furthermore, the concentration or band of impurities, especially nitrogen, increases within the boule, which can result in wafers having conductivity that is outside the required range or varies from one side of the wafer to the other within the same boule. In the case of semi-insulating SiC wafers for RF applications, very low conductivity is required, and thus very low concentrations of trace metals and nitrogen are acceptable within the wafer. In the case of conductive SiC wafers for power applications, a certain amount of conductivity is required. However, this conductivity is achieved uniformly throughout the SiC boule by providing nitrogen gas into the PVT crucible throughout the growth time.

[0010] The shape factor of the SiC source material is also important for PVT growth. Powder source materials provide a large initial surface area for sublimation and thus a high initial sublimation rate. A high sublimation rate can be uneconomical in the event that not all of the evaporated SiC species can be incorporated into the crystal and instead form parasitic polycrystalline deposits on other parts of the crucible. Worse yet, a high concentration of SiC species in front of the crystal growth face can lead to gas-phase nucleation and the formation of amorphous or polycrystalline inclusions within the single-crystalline boule. Over time, powder source materials tend to sinter together, producing a single block of material with a substantially reduced surface area and thus tailoring the sublimation rate. This spiking and tailoring sublimation curve for powder source materials results in overall slow growth with the potential for defects within the grown crystal. Ultimately, powder source materials have a low tap density of about 1.2 g / cm 3 which limits the mass of material that can be loaded into the crucible and thus the size of the crystal that can be grown.

[0011] Document GB1128757 discloses a method for the deposition of thin coatings of SiC. However, the teachings of GB1128757 are not related to methods for the production of large quantities of SiC as a PVT source material.

[0012] DE1184738(B) discloses a method for producing silicon carbide crystals in single-crystalline and polycrystalline forms by reacting silicon halide with carbon tetrachloride in a 1:1 molar ratio in the presence of hydrogen on a heated graphite body. In this process, a mixture of 1 volume percent trichlorosilane, 1 volume percent carbon tetrachloride and hydrogen is first passed over the graphite body at a flow rate of 400 to 600 l / h until a dense silicon carbide layer is formed on the graphite body, and then passed over the deposition body at a flow rate of 250 to 350 l / h at 1500 to 1600 °C.

[0013] This prior art is disadvantageous because it does not meet today's requirements for high-purity SiC that is produced inexpensively in large-scale industrial processes. SiC is used in many technical fields, especially for power applications and / or e-mobility, to increase efficiency. In order for products that require SiC to have access to large markets, the manufacturing costs must be reduced and / or the quality must be improved.

Prior Art Documents

Patent Documents

[0014]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0015] Accordingly, it is an object of the present invention to provide a low-cost supply of silicon carbide (SiC). In addition to or in place of this, high-purity SiC should be provided. In addition to or in place of this, SiC should be provided very quickly. In addition to or in place of this, SiC should be able to be produced very effectively. In addition to or in place of this, single-crystalline SiC having advantageous properties should be produced.

Means for Solving the Problems

[0016] The object mentioned above is preferably solved by a SiC production reactor for the production of a PVT source material, which is UPSiC. The SiC production reactor according to the present invention comprises at least a processing chamber, a gas inlet unit for feeding one or more feed media into the reaction space of the processing chamber for generating a source medium, and one or more SiC growth substrates arranged inside the processing chamber for depositing SiC, in particular up to 64 or more SiC growth substrates.

[0017] This solution is beneficial because the SiC material, in particular the PVT source material, can be produced on an industrial scale using this SiC production reactor.

[0018] According to a preferred embodiment of the present invention, each SiC growth substrate comprises a first power connection part and a second power connection part. The first power connection part is a first metal electrode, and the second power connection part is a second metal electrode. The first metal electrode and the second metal electrode are preferably isolated from the reaction space inside the processing chamber. Each SiC growth substrate is coupled between at least one first metal electrode and at least one second metal electrode for heating the outer surface of the SiC growth substrate or the surface of the deposited SiC to a temperature between 1300 °C and 1800 °C, in particular using resistive heating, preferably by internal resistive heating. This embodiment is beneficial because the SiC growth substrate can be heated in a very effective manner.

[0019] The flowing current requires an inlet electrode and an outlet electrode, and these electrodes are preferably arranged in a plurality of pairs, such as 12 pairs or 18 pairs or 24 pairs or 36 pairs or more. Each of the deposition substrate and the SiC growth substrate is preferably attached to each electrode of the electrode pair, particularly the metal electrodes (the first and second metal electrodes), and the substrate is connected by cross members, each of which is a bridge of the same material as the substrate, so as to complete an electrical circuit on its upper part. Each of the deposition substrate and the SiC growth substrate is preferably attached to the electrode through an intermediate component, each of which is a chuck. The chuck preferably has a reduced cross-sectional area extending from the electrode to the deposition substrate so that the current is concentrated and the resistive heating is enhanced. The purpose of the chuck is to maintain a temperature lower than the deposition temperature at the wider lower end and a temperature higher than the deposition temperature at the narrower upper end. The chuck preferably has a conical shape. The chuck, the deposition substrate, and the bridge are preferably made of graphite or, more preferably, high-purity graphite having a total ash content lower than 50000 ppm, preferably lower than 5000 ppm, and very preferably less than 500 ppm. The deposition substrate is also preferably made of SiC. According to yet another aspect of the present invention, the contact between the first metal electrode and the SiC growth substrate is in a different plane from the contact between the second metal electrode and the SiC growth substrate. The second electrode can preferably be arranged on the opposite side of the processing chamber and / or provided as part of the bell jar.

[0020] The processing chamber is at least surrounded by a base plate, a side wall section, and an upper wall section, according to a preferred embodiment of the present invention. This embodiment is beneficial because it can define, respectively, isolate the processing chamber by the base plate, the side wall section, and the upper wall section. The base plate is also preferably provided with a plurality of gas inlet ports and one or more gas outlet ports. The gas inlet ports and the outlet ports are arranged so as to generate an optimal flow of the feed gas inside the CVD reactor, respectively, the SiC production reactor, particularly the SiC PVT source material production reactor, so that the unused feed gas is constantly brought into contact with the deposition surface on the deposition substrate.

[0021] The gas inlet unit is coupled to at least one feed medium source, according to yet another preferred embodiment of the present invention. One feed medium source is an Si and C feed medium source, and the Si and C feed medium source provides at least Si and C, particularly SiCl3(CH3). The carrier gas feed medium source provides a carrier gas, particularly H2. Alternatively, the gas inlet unit is coupled to at least two feed medium sources. One of the two feed medium sources is an Si feed medium source, and the Si feed medium source provides at least Si, particularly an Si gas according to the general formula SiH4-yXy (X = [Cl, F, Br, J] and y = [0..4]). The other of the two feed medium sources is a C feed medium source, and the C feed medium source provides at least C, particularly natural gas, methane, ethane, propane, butane, and / or acetylene. The carrier gas medium source provides a carrier gas, particularly H2.

[0022] Alternatively, the first feed medium is a Si feed medium, in particular a Si gas according to the general formula SiH4-yXy (X = [Cl, F, Br, J] and y = [0..4]), the gas inlet unit is coupled to at least one feed medium source, the Si and C feed medium sources provide at least Si and C, in particular SiCl3(CH3), the carrier gas feed medium source provides a carrier gas, in particular H2, or the gas inlet unit is coupled to at least two feed medium sources, the Si feed medium source provides at least Si, in particular, the Si feed medium source provides the first feed medium, the first feed medium is a Si feed medium, in particular a Si gas according to the general formula SiH4-yXy (X = [Cl, F, Br, J] and y = [0...4]), the C feed medium source provides at least C, in particular, the C feed medium source provides the second feed medium, the second feed medium is a C feed medium, in particular natural gas, methane, ethane, propane, butane, and / or acetylene, and the carrier gas medium source provides the third feed medium, the third feed medium is a carrier gas, in particular H2.

[0023] Natural gas preferably defines a gas having a plurality of components, the largest component being methane, in particular more than 50% (by mass) being methane, preferably more than 70% (by mass) being methane, very preferably more than 90% (by mass) being methane, and most preferably more than 95% (by mass) or more than 99% (by mass) being methane.

[0024] That is, the SiC production reactor, the CVD SiC apparatus respectively, is also preferably equipped with a feed gas unit for feeding the feed gas to the gas inlet unit, the media supply unit respectively. The feed gas unit, the media supply unit respectively, ensures that the feed gas is heated to an appropriate temperature and mixed in an appropriate ratio before being pumped into the CVD reactor, the SiC production reactor respectively, especially the SiC PVT source material production reactor. The feed gas unit, the media supply unit respectively, starts with pipes and pumps that convey the feed gas from its respective source, especially the storage tank, to around the CVD reactor, the SiC production reactor respectively, especially the SiC PVT source material production reactor. Here, preferably the mass flow rate of each feed gas is controlled so that it can reach the appropriate ratio of the various feed gases by an individual mass flow meter preferably connected to the overall process control unit. Further, the separate feed gases are preferably mixed in the mixing unit of the media supply unit especially and pumped into the CVD reactor, the SiC production reactor respectively, especially the SiC PVT source material production reactor through the gas inlet unit, especially its plurality of gas inlet ports. Preferably, the feed gas unit, the media supply unit respectively, can mix three feed gases including an Si-containing gas such as STC and / or TCS, a C-containing gas such as methane, and a carrier gas such as H. In another preferred embodiment of the present invention, there is a feed gas containing both Si and C such as MTCS, and the feed gas unit mixes two gases instead of three, namely, MTCS and H. It should be noted that STC, TCS, and MTCS are liquids at room temperature. Therefore, a preheater for first heating these feed liquids may be required upstream of the gas inlet unit, especially upstream of the feed gas unit, the media supply unit respectively, so that these feed liquids become feed gases that can be immediately mixed with other feed gases.

[0025] Preferably, these gases are mixed such that an atomic ratio of 1:1 exists between Si and C. In some cases, it may be more preferable to mix these gases such that a different atomic ratio exists between Si and C. Sometimes, in order to achieve a higher deposition rate, it is desirable to maintain the deposition surface at the upper end of the deposition temperature range from 1300°C to 1600°C. However, under such conditions, there is a possibility of excessive C deposition into SiC. This excessive C deposition can be alleviated by mixing the feed gases such that the Si:C ratio is higher than 1:1, preferably 1:1.1, 1:1.2, or 1:1.3. Conversely, sometimes, in order to result in deposition without stress at a low speed, it is desirable to maintain the deposition surface at the lower end of the deposition temperature range. Under such conditions, there is a possibility of excessive Si deposition into SiC. The excessive Si deposition can be alleviated by mixing the feed gases such that the Si:C ratio is lower than 1:1, preferably 1:0.9, 1:0.8, or 1:0.7.

[0026] A further important consideration regarding the feed gas mixture is the atomic ratio of H to Si and C. Excessive H may dilute Si and C and reduce the deposition rate. Similarly, excessive H may increase the volume of the vent gas flowing out of the CVD reactor, respectively, the SiC production reactor, especially the SiC PVT source material production reactor, and may complicate the treatment and recirculation of any of these vent gases. On the other hand, insufficient H may delay the chemical chain reaction and result in SiC deposition. The molar ratio of H2 to Si is preferably in the range of 2:1 to 10:1, more preferably between 4:1 and 6:1.

[0027] According to yet another embodiment of the present invention, more than 4 or at most 4, preferably more than 6 or more than 8 or at most these numbers, very preferably more than 16, more than 32, or more than 64 or at most these numbers, most preferably at most 128 or at most 256 SiC growth substrates can be arranged inside one SiC production reactor.

[0028] This embodiment is beneficial because the output of the SiC reactor can be significantly increased by adding an additional SiC growth substrate.

[0029] According to yet another preferred embodiment of the present invention, a control unit is provided for setting a feed medium supply of one or more feed media into a processing chamber, the control unit being configured to set the feed medium supply between a minimum amount of feed medium supply (mass) per minute and a maximum amount of feed medium supply (mass) per minute, the minimum amount of feed medium supply (mass) per minute corresponding to a minimum deposition amount (mass) of Si and a minimum deposition amount (mass) of C at a determined mass growth rate, the determined mass growth rate being higher than 0.1 g per hour per 1 cm2 of the SiC growth surface, and the maximum amount of feed medium supply per minute being at most 30% (mass), at most 20% (mass), at most 10% (mass), at most 5% (mass), or at most 3% (mass) higher compared to the minimum amount of feed medium supply. This embodiment is beneficial because the feed medium supply can be controlled depending on desired SiC conditions.

[0030] According to yet another preferred embodiment of the present invention, the control unit is configured to control the current flowing through the SiC growth substrate to maintain the surface temperature of the SiC growth substrate or to set the surface temperature of the deposited SiC. This embodiment is beneficial because the deposition of SiC can be maintained by setting the required temperature conditions.

[0031] According to yet another preferred embodiment of the present invention, the control unit is configured to control the current amount and the feed medium supply for at least 1 hour, preferably at least 2 hours, 4 hours, or 6 hours, to continuously deposit SiC at a determined surface growth rate and / or a determined radial growth rate. This embodiment is beneficial because large SiC solids can be generated.

[0032] According to yet another preferred embodiment of the present invention, the control unit is a hardware arrangement configured to modify the current amount, and the modification of the current amount within a range of a first defined period from the start of the generation process is predefined. This embodiment can adapt the hardware to the defined process and is thus beneficial as no additional sensors are required. Preferably, the first period is 1 hour or longer, or up to 60% of the maximum duration of the generation process, up to 80% of the maximum duration of the generation process, up to 90% of the maximum duration of the generation process, or up to 100% of the maximum duration of the generation process. Preferably, the hardware arrangement is configured to modify the feed medium supply, and the modification of the feed medium supply within a range of a second defined period from the start of the generation process is predefined, and the second period is 1 hour or longer, or up to 60% of the maximum duration of the generation process, up to 80% of the maximum duration of the generation process, up to 90% of the maximum duration of the generation process, or up to 100% of the maximum duration of the generation process.

[0033] According to yet another preferred embodiment of the present invention, at least one sensor is provided, the sensor is coupled to the control unit to provide a sensor signal or sensor data to the control unit, the control unit controls the current amount and the feed medium supply depending on the sensor signal or sensor data of the at least one sensor, and the at least one sensor is a temperature sensor for monitoring the surface temperature of at least one of the substrates. The at least one temperature sensor is preferably a camera, particularly an IR camera. Preferably, a plurality of temperature sensors are provided, the number of temperature sensors corresponds to the number of SiC growth substrates, and at least one, particularly 2, 5, 10, or 20 temperature sensors are provided per 10 SiC growth substrates, or at least one, particularly 2, 5, 10, or 20 temperature sensors are provided per 5 SiC growth substrates, or at least one, particularly 2, 5, 10, or 20 temperature sensors are provided per 2 SiC growth substrates. Preferably, the temperature sensor outputs a temperature sensor signal or temperature sensor data representing the measured temperature, particularly the surface temperature. This embodiment is beneficial as it can immediately adjust the state inside the SiC generation reactor.

[0034] According to yet another preferred embodiment of the present invention, at least one substrate diameter measurement sensor is provided. Preferably, the substrate diameter measurement sensor is an IR camera for determining the growth of the substrate diameter. Preferably, it outputs a diameter measurement signal or diameter measurement data representing the measured substrate diameter or its variation, and / or resistance diameter means for determining a change in electrical resistance for determining the growth of the substrate diameter. Preferably, it outputs a diameter measurement signal or diameter measurement data representing the measured substrate diameter or its variation. This embodiment is beneficial because it can correct, particularly enhance, the dependency on measurement data or value parameters such as the current amount or feed medium supply.

[0035] According to yet another preferred embodiment of the present invention, one or more valves are provided. The one or more valves are configured to operate depending on the measured temperature, particularly depending on a temperature sensor signal or temperature sensor data, and / or depending on the measured substrate diameter, particularly depending on a diameter measurement signal or diameter measurement data. The one or more valves can be part of the gas inlet unit. This embodiment is beneficial because it can control the feed medium flow and / or the ventilation gas flow. Therefore, according to yet another preferred embodiment of the present invention, the control unit is configured to enhance the electrical activation of at least one SiC growth substrate over time, particularly to heat the surface of the deposited SiC to a temperature between 1300 °C and 1800 °C.

[0036] According to yet another preferred embodiment of the present invention, the power supply unit for providing current is configured to provide current depending on a diameter measurement signal or diameter measurement data. This embodiment is beneficial because it can control the feed medium flow and / or the ventilation gas flow.

[0037] That is, preferably, the control unit is configured to receive and process a temperature sensor signal or temperature sensor data, and / or a diameter measurement signal or diameter measurement data, and / or to control one or more valves and / or the power supply unit.

[0038] According to yet another preferred embodiment of the present invention, the control unit is configured to control the feed medium flow and the temperature of the surface of the deposited SiC to deposit SiC at a set deposition rate, in particular a vertical deposition rate, for a time longer than 2 hours, in particular longer than 3 hours or up to 3 hours, longer than 5 hours or up to 5 hours, longer than 8 hours or up to 8 hours, preferably longer than 10 hours or up to 10 hours, very preferably longer than 15 hours or up to 15 hours, most preferably longer than 24 hours or up to 24 hours, up to 72 hours, or up to 100 hours. This embodiment is beneficial because a large amount of SiC can be grown.

[0039] According to yet another preferred embodiment of the present invention, the base plate comprises at least one cooling element, in particular a base cooling element, for preventing it from being heated above a defined temperature, and / or the side wall section comprises at least one cooling element, in particular a bell-jar cooling element, for preventing it from being heated above a defined temperature, and / or the upper wall section comprises at least one cooling element, in particular a bell-jar cooling element, for preventing it from being heated above a defined temperature.

[0040] This embodiment is beneficial because the present invention discloses a SiC CVD apparatus for the mass commercial production of ultra-high purity bulk CVD SiC. The central equipment within the SiC CVD apparatus is the CVD unit, each a CVD reactor, each a SiC production reactor, in particular a SiC PVT source material production reactor. Preferably, each CVD reactor, each SiC production reactor, in particular each SiC PVT source material production reactor, comprises a cooling element, in particular a double-wall fluid cooling, in particular a water-cooled or oil-cooled lower housing, each a base plate, and a double-wall liquid-cooled upper housing, each a bell jar. Preferably, the inner wall of the base plate, in particular the bell jar, is manufactured from a material having an operating temperature adapted to the operating temperature of each CVD reactor, each SiC production reactor, in particular each SiC PVT source material production reactor. In particular, the inner wall of the bell jar can be manufactured from stainless steel. Preferably, this inner wall reflects radiant energy back, minimizes heat loss, and thus minimizes electricity costs, and in addition to or instead of this, is preferably coated with a reflective coating such as silver or preferably gold. Preferably, the bell jar and / or the base plate are manufactured from high-temperature resistant stainless steel. However, current high-temperature steels with added chromium, nickel, cerium, or yttrium have a resistance to temperatures up to 1300 °C (in air). As an example, steel EN1.4742 (X10CrAlSi18) has a heat resistance at a temperature of up to 1000 °C. In another example, alloy steel EN2.4816 (UNS N06600) withstands a temperature of 1250 °C and melts at temperatures higher than 1370 °C, but its tensile strength drops to a level lower than 10% of the room temperature value at temperatures higher than 1100 °C. Therefore, none of these steels can withstand the very high temperatures required for SiC absorption above 1300 °C.

[0041] Therefore, it is advantageous to provide a cooling element to reduce the temperature of the bell jar and / or the base plate to an acceptable level for the use of high-temperature stainless steel.

[0042] Preferably, one or more fluid-cooled, particularly water-cooled or oil-cooled electrodes are arranged on the base plate for resistively heating the deposition substrate and for providing electrical through-connections to the CVD reactor, respectively, the SiC production reactor, in particular the SiC PVT source material production reactor. According to yet another preferred embodiment of the invention, the cooling element is an active cooling element.

[0043] According to yet another preferred embodiment of the invention, the base plate, side wall section, and / or upper wall section comprises a cooling fluid guiding unit for guiding the cooling fluid, and the cooling fluid guiding unit is configured to limit the heating of the base plate, side wall section, and / or upper wall section to a temperature lower than 1300 °C. This embodiment is beneficial since it can provide a metal, particularly steel bell jar. The steel bell jar is beneficial since it can be produced significantly larger compared to a quartz bell jar.

[0044] According to yet another preferred embodiment of the invention, a base plate sensor unit, a side wall section sensor unit, and / or an upper wall section sensor unit are provided for detecting the temperature of the base plate, side wall section, and / or upper wall section and outputting a temperature signal or temperature data, and a fluid forward-feed unit is provided for feeding the cooling fluid forward through the fluid guiding unit. This embodiment is beneficial since it enables continuous cooling without losses or contamination of the cooling fluid and / or the processing chamber.

[0045] According to yet another preferred embodiment of the present invention, the fluid forward delivery unit is configured to be operated depending on temperature signals or temperature data provided by a base plate sensor unit, a side wall section sensor unit, and / or an upper wall section sensor unit. This embodiment is beneficial because metal impurities can be avoided when the bell jar and / or the base plate operate at a temperature lower than 1000°C, preferably lower than 800°C, and very preferably lower than 400°C, or when the bell jar and / or the base plate are cooled to a temperature lower than 1000°C, preferably lower than 800°C, and very preferably lower than 400°C.

[0046] According to yet another preferred embodiment of the present invention, the cooling fluid is oil or water, and preferably, the water comprises at least one additive, particularly a rust inhibitor and / or an antifouling agent (biocide). This embodiment is beneficial because the coolant can be modified to avoid defects or contamination in the SiC production reactor.

[0047] According to yet another preferred embodiment of the present invention, the cooling element is a passive cooling element. This embodiment is beneficial because the passive cooling element does not require a constant monitor.

[0048] According to yet another preferred embodiment of the present invention, the cooling element is at least partially formed by a polished steel surface of the base plate, the side wall section, and / or the upper wall section. According to yet another preferred embodiment of the present invention, the cooling element is a coating, and the coating is formed on the polished steel surface and configured to reflect heat. According to yet another preferred embodiment of the present invention, the coating is a metal coating or comprises a coating of metal, particularly silver, gold, chromium, or an alloy, particularly a CuNi alloy. According to yet another preferred embodiment of the present invention, the emissivity of the polished steel surface and / or the coating is less than 0.3, particularly less than 0.1 or less than 0.03. This embodiment is beneficial because a high amount of heat radiation can be reflected back to the SiC growth surface due to the polished surface and / or the coating.

[0049] That is, according to yet another preferred embodiment of the present invention, at least one section of the bell jar surface and / or at least one section of the base unit surface is provided with a coating, in particular a reflective coating, and this section of the bell jar surface and / or this section of the base unit surface forms the boundary of the reaction space, the coating is a metal coating, in particular comprising or consisting of gold, silver, aluminum, and / or platinum, and / or is configured to reflect at least 2%, at least 5%, at least 10%, or at least 20% of the radiant energy emitted during one production operation onto the coating.

[0050] According to yet another preferred embodiment of the present invention, the base plate comprises at least one active cooling element and one passive cooling element to prevent it from being heated above a defined temperature, and / or the side wall section comprises at least one active cooling element and one passive cooling element to prevent it from being heated above a defined temperature, and / or the upper wall section comprises at least one active cooling element and one passive cooling element to prevent it from being heated above a defined temperature.

[0051] According to yet another preferred embodiment of the present invention, the side wall section and the upper wall section are formed by a bell jar, and preferably, the bell jar is movable relative to the base plate. According to yet another preferred embodiment of the present invention, more than 50% (by mass) of the side wall section, more than 50% (by mass) of the upper wall section, and / or more than 50% (by mass) of the base plate are made of metal, particularly steel. This embodiment is beneficial because it can produce a large steel bell jar, resulting in a significant increase in the processing chamber volume and thus a significant increase in the potential SiC material. Therefore, according to yet another preferred embodiment of the present invention, preferably, a bell jar is provided with a contact area for forming an interface with the base unit, the interface is sealed to prevent leakage of gas-phase species, the bell jar is provided with a bell jar cooling unit, the bell jar cooling element forms at least one channel, trench, or recess for holding or guiding the bell jar coolant, and the bell jar cooling element is configured to cool at least one section of the bell jar, preferably the entire bell jar, to a temperature lower than a defined temperature or to remove a defined amount of heat per minute during production operation. Preferably, the bell jar cooling element and / or the base plate cooling element are controlled by a control unit. In addition or instead of this, the bell jar cooling element and / or the base cooling element are coupled to each other to form one main cooling unit.

[0052] According to yet another preferred embodiment of the present invention, the base unit comprises at least one base cooling element for cooling it, and the base cooling element forms at least one channel, trench, or recess for holding or guiding a base coolant. According to yet another preferred embodiment of the present invention, the base cooling element is arranged within at least one region of the first metal electrode, preferably also within at least one region of the second metal electrode, inside the reactor within at least one region of the first metal electrode, preferably also within at least one region of the second metal electrode, and is configured to cool the base unit until its defined surface temperature is lower, or to remove a defined amount of heat per minute from the base unit, or the base cooling element is configured to cool the entire base unit below its defined temperature during full production operation, or to remove a defined amount of heat per minute during production operation. This embodiment is beneficial because the electrodes can be operated at high current without damaging the SiC reactor.

[0053] According to yet another preferred embodiment of the present invention, the first metal electrode and the SiC growth substrate are connected to each other through a first graphite chuck, and / or the second metal electrode and the SiC growth substrate are connected to each other through a second graphite chuck. This embodiment is beneficial because the current can be introduced into the SiC growth substrate in an even manner. According to yet another preferred embodiment of the present invention, the first graphite chuck and / or the second graphite chuck are mounted on the base unit.

[0054] According to yet another preferred embodiment of the present invention, preferably, in order to avoid metal species contamination of the reaction chamber by the metal species of the first metal electrode and the second metal electrode entering the base unit from the first side of the base unit, the first metal electrode and the second metal electrode are sealed from the reaction chamber and preferably extend to the other side of the base unit, which is opposite to the first side, inside the base unit. The first metal electrode, preferably, and further the second metal electrode extend inside the base unit to a sealing level below the processing chamber surface of the base unit formed on the other side of the base unit. This embodiment is beneficial because it can avoid contamination of the reaction space.

[0055] According to yet another preferred embodiment of the present invention, a sealing wall member is formed between the sealing level and the processing chamber surface, and the sealing wall member separates the SiC growth substrate from the first metal electrode and preferably further from the second metal electrode. This embodiment is beneficial because it can prevent short circuits.

[0056] According to yet another preferred embodiment of the present invention, the control unit is configured to control the current flowing through the SiC growth substrate to maintain the surface temperature of the SiC growth substrate or set the surface temperature of the deposited SiC, and is coupled to a power supply unit for providing current, the power supply unit being configured to receive power data or a power signal provided by the control unit, and / or with respect to the supply of one or more feed media into the processing chamber, the control unit is coupled to a media supply unit for feeding one or more feed media to a gas inlet unit, the media supply unit being configured to receive media supply data or a media supply signal provided by the control unit, and / or with respect to the cooling of the base unit, the control unit is coupled to a base cooling element for cooling the base unit, the base cooling element being configured to receive base cooling data or a base cooling signal provided by the control unit, and / or with respect to the cooling of the bell jar, the control unit is coupled to a bell jar cooling element for cooling the bell jar, the bell jar cooling element being configured to receive bell jar cooling data or a bell jar cooling signal provided by the control unit, and / or the control unit is configured to set a deposition rate higher than 200 μm / h, in particular a vertical deposition rate, by controlling at least the power supply unit and the media supply unit. This embodiment is advantageous because the control unit can control a plurality of parameters and thus increase the output by operating the heating unit, the supply unit, and the cooling unit simultaneously.

[0057] According to yet another preferred embodiment of the present invention, the medium supply unit is configured to supply one or more feed media into the processing chamber at a pressure higher than 1 bar, particularly higher than 1.2 bar, preferably higher than 1.5 bar, very preferably higher than 2 bar, 3 bar, 4 bar, 5 bar respectively, and particularly up to a maximum of 10 bar or up to a maximum of 20 bar. According to yet another preferred embodiment of the present invention, in addition to or instead of this, the medium supply unit is configured to supply one or more feed media and carrier gas into the processing chamber at a pressure higher than 1 bar, particularly higher than 1.2 bar, 1.5 bar, 2 bar, 3 bar, 4 bar, or 5 bar. This embodiment is beneficial because the material density is high inside the processing chamber, whereby a large amount of Si material and C material reach the SiC growth surface, thus resulting in high-quality SiC growth.

[0058] According to yet another preferred embodiment of the present invention, at least one SiC growth substrate, preferably a plurality of SiC growth substrates or all SiC growth substrates, are formed in an I-shape, E-shape, or U-shape, and at least one SiC growth substrate, a plurality of SiC growth substrates, or all SiC growth substrates are connected to a first metal electrode through a base unit, particularly a sealing wall member, and / or at least one SiC growth substrate, preferably a plurality of SiC growth substrates or all SiC growth substrates, are formed in an I-shape, E-shape, or U-shape, and at least one SiC growth substrate, a plurality of SiC growth substrates, or all SiC growth substrates are connected to a second metal electrode through a base unit, particularly a sealing wall member. This embodiment is beneficial because the length of the SiC growth substrate can be approximately 2× or about 2× the length of the I-shape, particularly with respect to the U-shape. Furthermore, the electrodes of the U-shaped SiC growth substrate can be mounted on the same wall member, particularly the base plate.

[0059] According to yet another preferred embodiment of the present invention, the inlet unit comprises a plurality of orifices for causing a turbulent gas flow within a distance shorter than 20 mm, shorter than 10 mm, or shorter than 2 mm inside the processing chamber, particularly up to the surface of the SiC growth substrate or the surface of the SiC deposited thereon. Since the surface of the deposited SiC grows, particularly grows continuously, the region where the turbulence is maintained may change. This embodiment is beneficial because the deposition rate can be increased by more Si material and C material reaching the SiC growth substrate surface or the SiC growth surface due to the turbulence.

[0060] According to yet another preferred embodiment of the present invention, the control unit is configured to control the media supply unit to feed one or more feed media into the processing chamber, and the one or more feed media have a molar ratio Si:C of Si = 1 and C = 0.8 to 1.1, or an atomic ratio Si:C of Si = 1 and C = 0.8 to 1.1. This embodiment is beneficial because the desired material ratio can be controlled and set. That is, a control unit is provided for setting the feed media supply of one feed media and a carrier gas into the processing chamber. Preferably, the control unit is configured to control the media supply unit to feed one feed media having a defined molar ratio and / or a defined atomic ratio into the processing chamber. The one feed media and the carrier gas have a defined molar ratio Si:H of Si = 1 and H = 2 to 10, preferably 5 to 10, very preferably 5 to 7, or an atomic ratio Si:H of Si = 1 and H = 2 to 10, preferably 5 to 10, very preferably 5 to 7. Or in the control unit for setting the feed media supply of a plurality of feed media into the processing chamber, the control unit is configured to control the media supply unit to feed the plurality of feed media into the processing chamber at a defined molar ratio and / or a defined atomic ratio. The plurality of feed media have a defined molar ratio Si:C of Si = 1 and C = 0.8 to 1.1, or a defined atomic ratio Si:C of Si = 1 and C = 0.8 to 1.1.

[0061] According to yet another preferred embodiment of the present invention, the Si and C feed medium sources are coupled to at least one Si and C feed medium orifice of the inlet unit, and the carrier gas feed medium source is coupled to at least one carrier gas orifice of the inlet unit. Preferably, the Si and C feed medium orifice and the carrier gas orifice are different from each other, or the Si and C feed medium sources and the carrier gas feed medium source are coupled to at least one common mixing element and / or guiding element, in particular a pipe. The at least one common mixing element and / or guiding element is coupled to at least one orifice of the inlet unit.

[0062] According to yet another preferred embodiment of the present invention, there is provided an Si and C supply device for feeding the Si and C feed medium from the Si and C feed medium sources into the reaction space through at least one orifice of the inlet unit, and / or a carrier gas supply device for feeding the carrier gas feed medium from the carrier gas feed medium source into the reaction space through at least one orifice of the inlet unit, and / or a feed medium supply device for introducing a mixture of the Si and C feed medium and the carrier gas feed medium into the reaction space through at least one orifice of the inlet unit from a common mixing element and / or guiding element.

[0063] According to yet another preferred embodiment of the present invention, instead, the Si feed medium source is coupled to at least one Si feed medium source orifice of the inlet unit, the C feed medium source is coupled to at least one C feed medium source orifice of the inlet unit, the carrier gas medium source is coupled to at least one carrier gas feed medium source orifice of the inlet unit, the Si feed medium source orifice, the C feed medium source orifice, and / or the carrier gas feed medium source orifice are different from each other, or the Si feed medium source and the C feed medium source are coupled to at least one common mixing element and / or guiding element, particularly a pipe, and at least one common mixing element and / or guiding element is coupled to at least one orifice of the inlet unit, or the Si feed medium source and the carrier gas feed medium source are coupled to at least one common mixing element and / or guiding element, particularly a pipe, and at least one common mixing element and / or guiding element is coupled to at least one orifice of the inlet unit, or the C feed medium source and the carrier gas feed medium source are coupled to at least one common mixing element and / or guiding element, particularly a pipe, and at least one common mixing element and / or guiding element is coupled to at least one orifice of the inlet unit, or the Si feed medium source, the C feed medium source, and the carrier gas feed medium source are coupled to at least one common mixing element and / or guiding element, particularly a pipe, and at least one common mixing element and / or guiding element is coupled to at least one orifice of the inlet unit.

[0064] According to yet another preferred embodiment of the present invention, there is provided an Si supply device for feeding an Si feed medium from an Si feed medium source through at least one orifice of an inlet unit into the reaction space, and / or a C supply device for feeding a C feed medium from a C feed medium source through at least one orifice of the inlet unit into the reaction space, and / or a carrier gas supply device for feeding a carrier gas from a carrier gas feed medium source through at least one orifice of the inlet unit into the reaction space. The Si supply device, the C supply device, and / or the carrier gas supply device are preferably pumps, particularly pressure pumps.

[0065] According to yet another preferred embodiment of the present invention, at least one outlet unit or vent gas outlet for removing gas from the reaction space is provided as part of the bell jar and / or part of the base unit. This embodiment is beneficial because the used gas can be guided outside the processing chamber, and thus the amounts of Si and C are not significantly affected by the presence of the vent gas that is not discharged. According to yet another preferred embodiment of the present invention, a pump device is coupled to the outlet unit for removing gas from the reaction space, and the pump device is preferably a vacuum pump.

[0066] According to yet another preferred embodiment of the present invention, the Si feed medium source is configured to provide a Si feed medium having a purity of at least 6N, particularly 7N, preferably 8N, or very preferably 9N, the C feed medium source is configured to provide a C feed medium having a purity of at least 6N, particularly 7N, preferably 8N, or very preferably 9N, or the Si and C feed medium sources are configured to provide Si and C feed media having a purity of at least 6N, particularly 7N, preferably 8N, or very preferably 9N, and the carrier gas feed medium source is configured to provide a carrier gas feed medium having a purity of at least 6N, particularly 7N, preferably 8N, or very preferably 9N.Therefore, at least a first feed medium, in particular a first source gas, comprising Si and having a purity excluding at least 99.99999% (weight ppm) of substance B, Al, P, Ti, V, Fe, Ni, in particular one of these substances, preferably a plurality, very preferably most, or most preferably all, is introduced into the processing chamber; at least a second feed medium, in particular a second source gas, comprising C and having a purity excluding at least 99.99999% (weight ppm) of substance B, Al, P, Ti, V, Fe, Ni, in particular one of these substances, preferably a plurality, very preferably most, or most preferably all, is introduced into the processing chamber; and a carrier gas having a purity excluding at least 99.99999% (weight ppm) of substance B, Al, P, Ti, V, Fe, Ni, in particular one of these substances, preferably a plurality, very preferably most, or most preferably all, is introduced. Or a feed medium, in particular a source gas, comprising Si and C and having a purity excluding at least 99.99999% (weight ppm) of substance B, Al, P, Ti, V, Fe, Ni, in particular one of these substances, preferably a plurality, very preferably most, or most preferably all, is introduced into the processing chamber; and a carrier gas having a purity excluding at least 99.99999% (weight ppm) of substance B, Al, P, Ti, V, Fe, Ni, in particular one of these substances, preferably a plurality, very preferably most, or most preferably all, is introduced. Therefore, the present invention discloses a CVD reactor for the production of a SiC source material supplied in the form of granules or solids having a shape factor that is at least 8N or preferably 9N when first manufactured and that preferably minimizes surface contamination during subsequent handling and use. This ultra-high-purity SiC source material (UPSiC) is produced by a CVD reactor or process that can purify the feed gas used to a very high level using an effective technique such as distillation. SiC or PVT source material SiC, in particular UPSiC, is generally first deposited in the form of long, thick rods and then deaggregated, in particular cut or ground, into a shape or size for use in a PVT crucible.Preferably, the grinding equipment is made of materials that do not contaminate SiC. Furthermore, there may be another acid etching step to remove fine powder and guarantee surface purity. This embodiment is beneficial because it can produce large and very high-purity particles with advantageous sublimation characteristics. When the etching step is carried out, particularly a few atomic layers (thinner than 1 μm compared to 10 - 50 μm in Si etching) will be removed by HF / HNO3. This is beneficial because it can remove the bluish-brown color after annealing due to etching. In addition to or instead of this, for example, an acidic sorting acid composed of HCl:HF:H2O2 and / or a different acid mechanism can be used to remove the oxide layer.

[0067] Chemical vapor deposition occurs when the deposition substrate and each SiC growth substrate are heated to the deposition temperature range and the feed gas mixture is introduced into the CVD reactor, each SiC production reactor, particularly the SiC PVT source material production reactor. When the feed gas mixture contacts the heated deposition substrate, the given energy causes a series of forward and reverse chemical reactions, and the result is the deposition of solid SiC on the deposition substrate. When the feed gas mixture comprises STC and methane, the net reaction can be summarized by the following equation. SiCl4 + CH4 = SiC + 4HCl

[0068] It should be noted that not all Si-containing molecules and all C-containing molecules are in contact with the deposition surface and undergo deposition reactions. Therefore, it is preferable to pump the feed gas faster than it deposits on the substrate as SiC. For example, when X moles of SiC are deposited per hour per square centimeter of the deposition surface, it may be necessary to pump AX moles of Si and AX moles of C per hour into the CVD reactor, the SiC production reactor, especially the SiC PVT source material production reactor, respectively, when A is in the range between 8 and 10. The smaller this A, the higher the conversion efficiency from the feed gas to the deposited SiC. This efficiency is improved by optimizing the gas flow inside the CVD reactor, the SiC production reactor, especially the SiC PVT source material production reactor, to maximize the contact between the feed gas mixture and the deposition surface.

[0069] According to yet another preferred embodiment of the present invention, the surface of the base unit defining the boundary of the reaction space and the upper surface section of the bell jar surface defining the boundary of the reaction space are spaced apart by a first distance, and the upper surface section of the bell jar surface is arranged at the farthest distance in the height direction to the base unit surface. The first distance is the farthest distance, and one or more SiC growth substrates extend over a second distance in the height direction. The second distance is less than 90% of the height of the first distance, or less than 90% of the height of the first distance, or less than 80% of the height of the first distance, or less than 75% of the height of the first distance, or less than 70% of the height of the first distance. Or one or more SiC growth substrates extend over a second distance in the height direction, and the first distance is at most 10%, at most 20%, at most 30%, or at most 50% longer compared to the second distance. According to yet another preferred embodiment of the present invention, the first distance is longer than 100 cm, at most 100 cm, or exactly 100 cm, preferably longer than 130 cm, at most 130 cm, or exactly 130 cm, longer than 150 cm, at most 150 cm, or exactly 150 cm, very preferably longer than 170 cm, at most 170 cm, or exactly 170 cm, longer than 200 cm, at most 200 cm, or exactly 200 cm, longer than 250 cm, at most 250 cm, or exactly 250 cm, or longer than 300 cm, at most 300 cm, or exactly 300 cm, and / or the inner diameter of the reaction space is longer than 50 cm, longer than 70 cm, at most 70 cm, or exactly 70 cm, preferably longer than 100 cm, at most 100 cm, or exactly 100 cm, preferably longer than 120 cm, at most 120 cm, or exactly 120 cm, or very preferably longer than 150 cm, at most 150 cm, or exactly 150 cm. This embodiment is beneficial because large SiC growth substrates can be used inside the SiC production reactor, and the production efficiency can be increased as described above.

[0070] According to yet another preferred embodiment of the present invention, the interface between the bell jar and the base unit is provided with a sealing, and the sealing is configured to withstand a pressure not greater than 1 bar, in particular not greater than 2 bar or 5 bar, and very preferably between 1 bar and 20 bar. This embodiment is beneficial because it can generate a high feed medium density inside the processing chamber, resulting in an advantageous supply of Si and C to the SiC growth substrate.

[0071] According to yet another preferred embodiment of the present invention, the bell jar defining the boundary of the reaction space, in particular its surface, and / or the base unit defining the boundary of the reaction space, in particular its surface, are configured to withstand chemical treatment, in particular caustic soda, for at least 30 seconds, at least 60 seconds, or at least 5 minutes. This embodiment is beneficial because the bell jar can be cleaned or optimized for reuse.

[0072] According to yet another preferred embodiment of the present invention, the SiC growth substrate is configured to hold a SiC solid having a mass greater than 1 kg, in particular greater than 5 kg or up to 5 kg, preferably greater than 50 kg or up to 50 kg, or very preferably greater than 200 kg or up to 200 kg, most preferably greater than 500 kg or up to 500 kg, and a thickness of at least 1 cm, in particular greater than 2 cm or up to 2 cm, preferably greater than 5 cm or up to 5 cm, preferably greater than 10 cm or up to 10 cm, or very preferably greater than 20 cm or up to 20 cm or greater than 50 cm or up to 50 cm. This embodiment is beneficial because it can produce a large amount of SiC material or PVT source material.

[0073] According to yet another preferred embodiment of the present invention, the reaction space volume enables the generation of one SiC solid or the simultaneous generation of a plurality of Si container storage locations, and the SiC solid weighs more than 1 kg, particularly more than 5 kg or at most 5 kg, preferably more than 50 kg or at most 50 kg, or very preferably more than 200 kg or at most 200 kg, most preferably more than 500 kg or at most 500 kg in mass, and has a thickness of at least 1 cm, particularly greater than or at most 2 cm, preferably greater than or at most 5 cm, preferably greater than or at most 10 cm, very preferably greater than or at most 20 cm, or most preferably greater than or at most 50 cm, or a plurality or all of the SiC solids weigh more than 1 kg, particularly more than 5 kg or at most 5 kg, preferably more than 50 kg or at most 50 kg, or very preferably more than 200 kg or at most 200 kg, most preferably more than 500 kg or at most 500 kg in mass, and have a thickness of at least 1 cm, particularly greater than or at most 2 cm, preferably greater than or at most 5 cm, preferably greater than or at most 10 cm, very preferably greater than or at most 20 cm, or most preferably greater than or at most 50 cm. This embodiment is beneficial because it can produce large amounts of SiC material or PVT source material.

[0074] According to yet another preferred embodiment of the present invention, the SiC growth substrate is preferably an elongated single-structure substrate. Preferably, the single-structure substrate comprises a plurality of sections having the same or similar diameters and / or the same or similar cross-sectional shapes. The diameter, particularly the diameter perpendicular to the direction of current flow, is at least 50% of the length of the single-structure substrate, preferably at least 70% of the length of the single-structure substrate, very preferably at least 90% of the length of the single-structure substrate, and most preferably at least 95% of the length of the single-structure substrate, and being the same or similar along the length, where being similar means that the maximum diameter is less than 200% of the minimum diameter, preferably less than 150% of the minimum diameter, very preferably less than 110% of the minimum diameter, and most preferably less than 105% of the minimum diameter. According to yet another preferred embodiment of the present invention, the SiC growth substrate is a multi-structure substrate comprising at least two elongated substrate components, and these at least two elongated, particularly linear and / or curved substrate components are arranged in a row and are in contact with each other, particularly by their end faces, preferably directly. Preferably, at least one substrate component, preferably two or more substrate components, form a curve in the direction of current flow. The diameters of the substrate components, particularly the linear and / or curved substrate components, perpendicular to the direction of current flow are preferably the same, or the maximum diameter is less than 200% of the minimum diameter, preferably less than 150% of the minimum diameter, or very preferably less than 110% of the minimum diameter, and most preferably less than 105% of the minimum diameter. According to yet another preferred embodiment of the present invention, the SiC growth substrate comprises three or more substrate components, and the substrate component contact surfaces between the contacting substrate components have the same or similar shapes and / or the same or similar sizes, where similar sizes mean that the maximum surface size of the substrate component contact surface is less than 200% of the surface size of the minimum substrate component contact surface, preferably less than 150% of the surface size of the minimum substrate component contact surface, very preferably less than 110% of the surface size of the minimum substrate component contact surface, or very preferably less than 105% of the surface size of the minimum substrate component contact surface.

[0075] According to yet another preferred embodiment of the present invention, the SiC growth substrate has a length and is at least indirectly coupled to one or at least one first metal electrode through a first end, and further at least indirectly coupled to one or at least one second metal electrode through a second end. The distance between the first end of the SiC growth substrate and the first metal electrode is shorter than 20% of the length of the SiC growth substrate, preferably shorter than 10% of the length of the SiC growth substrate, and most preferably shorter than 5% of the length of the SiC growth substrate. Preferably, the length of the SiC growth substrate is the physical extension of the direction of the current flow at the center of the SiC growth substrate.

[0076] For CVD reactors, each of the SiC production reactors, especially the total deposition area inside the SiC PVT source material production reactor, more deposits accumulate on the SiC growth substrate, and it must be further noted that the circumference of the deposit grows over time as it grows. The SiC growth substrate preferably has a diameter of at least 1.0 cm and can be, for example, a slender rod with a maximum height of 250 cm. This SiC growth substrate has a total surface area 10 times larger in ratio than at the start when it reaches a diameter of, for example, 10 cm due to the deposited SiC. Therefore, it is also necessary to increase the total feed gas mixture flow rate to adapt to this increase in volume deposition rate during the deposition run.

[0077] The SiC growth substrate can accumulate this layer so that the deposited layer can reach a total diameter of, for example, 20 cm. At this point, the circumference is about 60 cm, and when the vertical deposition rate is 1 mm per hour, the volume deposition rate is 6 cm3 per hour per cm of rod height. However, the average volume deposition rate throughout the run is actually close to 3 cm3 per hour per cm because the slender rod starts with such a small diameter.

[0078] According to the present invention, the average volume deposition rate is increased by using deposition substrates having a large starting area and SiC growth substrates, respectively. A slender rod with a diameter of 1 cm has an area of about 3 cm per 1 cm in height, while a deposition substrate in the form of a thin 10-cm-wide ribbon has a starting area of 20 cm per 1 cm in height, substantially increasing the average volume deposition rate dramatically and enabling the deposition of the same amount of SiC in a considerably shorter execution time. Therefore, CVD reactors, respectively, SiC generation reactors, particularly SiC PVT source material generation reactors, can perform more processes in a year. As a result, fewer CVD reactors, respectively, SiC generation reactors, particularly SiC PVT source material generation reactors, are required to produce the same total tonnage of SiC. Therefore, using a deposition substrate having a large starting area is a preferred embodiment of the present invention.

[0079] According to yet another preferred embodiment of the present invention, the SiC growth substrate has an average perimeter of at least 5 cm, preferably at least 7 cm, very preferably at least 10 cm around a cross-sectional area perpendicular to the length direction of the SiC growth substrate, or a plurality of SiC growth substrates each have an average perimeter of at least 5 cm, preferably at least 7 cm, very preferably at least 10 cm around a cross-sectional area perpendicular to the length direction of each SiC growth substrate. Preferably, the SiC growth substrate has an average perimeter of at most 25 cm, preferably at most 50 cm, or very preferably at most 100 cm. Very preferably, the SiC growth substrate has an average perimeter between 5 cm and 100 cm, preferably between 6 cm and 50 cm, very preferably between 7 cm and 25 cm, most preferably between 7.5 cm and 15 cm or between 5 cm and 20 cm, preferably between 5 cm and 15 cm, very preferably between 5 cm and 12 cm. This embodiment is beneficial because it can generate high volume growth due to the large perimeter. Therefore, the same amount of SiC can be generated considerably faster.

[0080] According to yet another preferred embodiment of the present invention, the SiC growth substrate comprises, or is composed of, SiC or C, in particular graphite, or a plurality of SiC growth substrates comprise, or are composed of, SiC or C, in particular graphite. Thus, graphite and carbon-carbon composites are preferred materials for use as deposition substrates for SiC. These materials can be easily separated from SiC by mechanical means and combustion, and ppm levels of residual C on SiC are not harmful to the performance of SiC as a source material for the PVT growth of single crystal SiC. However, the residual C can be removed from the SiC surface.

[0081] According to yet another preferred embodiment of the present invention, the shape of a cross-section perpendicular or orthogonal to the length direction of the SiC growth substrate is, for at least each section, preferably along more than 50% of the length of the SiC growth substrate, very preferably along more than 90% of the length of the SiC growth substrate, different from a circular shape.

[0082] According to yet another preferred embodiment of the present invention, the ratio (U / A) between the cross-sectional area (A) and the perimeter (U) is greater than 1.2 1 / cm, preferably greater than 1.5 1 / cm, very preferably greater than 2 1 / cm, and most preferably greater than 2.5 1 / cm. This embodiment is beneficial because a high ratio (U / A) allows for higher volume growth.

[0083] According to yet another preferred embodiment of the present invention, the SiC growth substrate is formed by at least one carbon ribbon, particularly a graphite ribbon, and at least one carbon ribbon has a first ribbon end and a second ribbon end, the first ribbon end being coupled to a first metal electrode and the second ribbon end being coupled to a second metal electrode, or each of a plurality of SiC growth substrates is formed by at least one carbon ribbon, particularly a graphite ribbon, and for each SiC growth substrate, at least one carbon ribbon has a first ribbon end and a second ribbon end, the first ribbon end being coupled to the first metal electrode of the respective SiC growth substrate and the second ribbon end being coupled to the second metal electrode of the respective SiC growth substrate. This embodiment is beneficial because the carbon ribbon or graphite ribbon can have a large surface area and a small volume, and thus more SiC can be grown simultaneously using the volume of the processing chamber. According to yet another preferred embodiment of the present invention, the carbon ribbon, particularly the graphite ribbon, comprises a curing agent.

[0084] According to yet another preferred embodiment of the present invention, the SiC growth substrate is formed by a plurality of rods, each rod having a first rod end and a second rod end, all the first rod ends being coupled to the same first metal electrode and all the second rod ends being coupled to the same second metal electrode, or each of a plurality of SiC growth substrates is formed by a plurality of rods, each rod having a first rod end and a second rod end, all the first rod ends being coupled to the same first metal electrode of the respective SiC growth substrate and all the second rod ends being coupled to the same second metal electrode of the respective SiC growth substrate. According to yet another preferred embodiment of the present invention, the rods of the SiC growth substrate are in contact with each other or are arranged at a distance from each other. According to yet another preferred embodiment of the present invention, the SiC growth substrate comprises 3 or more rods, or each of a plurality of SiC growth substrates comprises 3 or more rods. This embodiment is beneficial because the rods used can be standard components and are thus less expensive, for example, compared to graphite ribbons.

[0085] According to yet another preferred embodiment of the present invention, the SiC growth substrate is formed by at least one metal rod, the metal rod having a first metal rod end and a second metal rod end, the first metal rod end being coupled to a first metal electrode and the second metal rod end being coupled to a second metal electrode, or each of a plurality of SiC growth substrates is formed by at least one metal rod, each metal rod having a first metal rod end and a second metal rod end, the first metal rod end being coupled to the first metal electrode of each respective SiC growth substrate and the second metal rod end being coupled to the second metal electrode of each respective SiC growth substrate. This embodiment is beneficial because the metal rods are inexpensive and can be supplied in a plurality of shapes, particularly with a high ratio (U / A).

[0086] According to yet another preferred embodiment of the present invention, the metal rod is provided with a coating, the coating preferably comprising SiC and / or preferably the coating having a thickness greater than 2 μm, preferably greater than 100 μm, or very preferably greater than 500 μm, or having a thickness between 2 μm and 5 mm, particularly between 100 μm and 1 mm. This embodiment is beneficial because the grown solid can be more reliably removed from the metal rod, or less metal particles remain on the SiC solid after removing the SiC solid from the metal rod. Deposition substrates made of metal or alloy, and each SiC growth substrate, are also preferred due to their suitability for multiple uses of these substrates in subsequent SiC generation processes. Here, it is considered possible to use one or more coatings (preferably a carbon layer thinner than 1000 μm thick, very preferably thinner than 500 μm thick, and most preferably thinner than 100 μm thick) to prevent the metal of the substrate from penetrating into the SiC material body during deposition.

[0087] During the deposition process, the feed gas mixture is preferably continuously pumped into each CVD reactor, specifically the SiC production reactor, particularly the SiC PVT source material production reactor, and the purge gas preferably continuously flows out of the reactor. Due to the deposition reaction, the composition of the purge gas is quite different from that of the feed gas mixture. First, as indicated by the net deposition reaction, a large amount of HCl is generated and present in the purge gas along with the unreacted feed gas. Second, side reactions occur that result in the formation of other Si-containing molecules. For example, when the feed gas mixture contains STC, some TCS will be formed as a side reaction in each CVD reactor, specifically the SiC production reactor, particularly the SiC PVT source material production reactor, and will flow out in the purge gas.

[0088] In small-scale production of SiC, even if a high molar ratio of Si-containing gas to C-containing gas is used compared to SiC deposited with a relatively high molar ratio of H, it may not be advantageous to recycle the purge gas. Thus, in one embodiment of the present invention, the purge gas is first sent to a scrubber where it is contacted with water to remove all Si-containing compounds and HCl. Next, the purge gas is sent to a flare where it is burned using natural gas. As a result, a small amount of harmless CO2 is exhausted into the air. On the other hand, the scrubbing liquid is sent to a recycling company for further treatment, utilization, and disposal.

[0089] According to yet another preferred embodiment of the present invention, there is provided a gas outlet unit for taking out the vent gas and a vent gas recirculation unit, the vent gas recirculation unit being connected to the gas outlet unit and comprising at least a separation unit for separating the vent gas into a first fluid and a second fluid, the first fluid being a liquid and the second fluid being a gas, the first storage element and / or conduction element for storing or conducting the first fluid being part of or coupled to the separation unit, and the second storage element and / or conduction element for storing or conducting the second fluid being part of or coupled to the separation unit. This embodiment is beneficial because it can significantly reduce the source material cost. Preferably, the separation unit is operated at a pressure higher than 5 bar and a temperature lower than -30°C. Therefore, preferably, the vent gas is fed into a separation unit which can be a low-temperature distillation column, where the Si-containing compound condenses from the gaseous form to the liquid form, descends the column and flows out from the bottom, while the remaining H gas, HCl gas, and methane gas rise in the column and flow out from the top. The liquid is the first fluid and preferably mainly comprises HCl and chlorosilane and has a low percentage of H2 gas and C gas. The gas preferably mainly comprises H2 and C gas and has a low percentage of HCl and chlorosilane.

[0090] According to yet another preferred embodiment of the present invention, the vent gas recirculation unit separates the first fluid into at least two parts, namely a mixture of chlorosilanes and a mixture of HCl, H2 and at least one C-containing molecule, preferably, it comprises yet another separation unit for separating into at least three parts, namely a mixture of chlorosilanes, HCl, a mixture of H2 and at least one C-containing molecule, and the first storage element and / or conduction element connects the separation unit to yet another separation unit. This embodiment is beneficial because HCl, H2, and at least one C-containing molecule can be directly fed into the processing chamber of the SiC reactor for the production of SiC material or PVT source material. Preferably, the yet another separation unit is configured to operate at a pressure higher than 5 bar and a temperature lower than -30°C and / or a temperature higher than 100°C.

[0091] According to yet another preferred embodiment of the present invention, the yet another separation unit is coupled to a storage element and / or conduction element for the chlorosilane mixture, a storage element and / or conduction element for HCl, and a storage element and / or conduction element for H2 and C.

[0092] In the context of the present invention, "C" can be understood as "at least one C-containing molecule", thus, the storage element and / or conduction element for H2 and C can instead be understood as the storage element and / or conduction element for H2 and at least one C-containing molecule.

[0093] According to yet another preferred embodiment of the present invention, the storage element and / or conduction element for the chlorosilane mixture forms a section of the chlorosilane mixture mass flux path for conducting the chlorosilane mixture into the processing chamber. This embodiment is beneficial because the chlorosilanes can be used as a mixture. Thus, there is no need to further process the chlorosilane mixture with respect to the separation of individual chlorosilanes.

[0094] Therefore, due to the present invention, SiC source materials of at least 6N, preferably 7N, or more preferably 8N can be produced on a large scale, and the feed gas supplied and used is recycled from the ventilation gas of the first SiC raw material production reactor. This recycling measures the atomic ratio of H to C in the mixture and supplies appropriate ratios of H hydrogen and C-containing gas to the CVD reactor together with this mixture so that the overall H to C molar ratio of hydrogen and carbon in the C-containing gas is within the required range. Under given conditions in both the CVD reaction and subsequent low-temperature distillation, any carbon is present as methane. Any by-products derived from methane in the CVD reaction will have a higher boiling point and will be separated from the gas phase in low-temperature distillation. Methane can be quantified by in-line or on-line measurements (PAT, process analytical technology) such as, for example, flame ionization detectors, infrared spectroscopy in any mode (e.g., FTIR or NIR), or cavity ring-down spectroscopy (which has the most susceptible detection limit), or any other in-line or on-line analytical method that provides results with the required accuracy within seconds. The hydrogen content can be calculated from the measured total mass flow rate of the gas mixture and the quantified methane concentration. To maintain the molar ratio of the original feed gas mixture, preferably the losses are compensated. This embodiment is beneficial because the purity of Si, C, and H2 recycled due to the recycling of the ventilation gas is further increased, and thus the purity of the SiC product is even better.

[0095] According to yet another preferred embodiment of the present invention, a Si mass flux measurement unit for measuring the amount of Si in a chlorosilanes mixture is provided as yet another Si feed medium source that preferably provides yet another Si feed medium as part of the mass flux path before the processing chamber, particularly before the mixing device. According to yet another preferred embodiment of the present invention, a storage element and / or a conducting element of the chlorosilanes mixture forms a section of the chlorosilanes mixture mass flux path for conducting the chlorosilanes mixture into another processing chamber of yet another SiC production reactor. This embodiment is beneficial because it can be accurately controlled when a feed medium from a feed source or a feed medium from a recirculation unit is used. In addition to or instead of this, when the feed medium of the recirculation unit is insufficient, the feed medium from the feed source can be added to the feed medium from the recirculation unit.

[0096] According to yet another preferred embodiment of the present invention, the storage element and / or conduction element for H2 and C forms a section of the mass flux path for H2 and C for conducting H2 and at least one C-containing molecule into the processing chamber. Further, it is possible for HCl to be present. According to yet another preferred embodiment of the present invention, the C mass flux measurement unit for measuring the amount of C in the mixture of H2 and at least one C-containing molecule is preferably provided as yet another C feed medium source that provides yet another C feed medium as part of the mass flux path of H2 and C in front of the processing chamber, particularly in front of the mixing device. According to yet another preferred embodiment of the present invention, the storage element and / or conduction element for H2 and C forms a section of the mass flux path for H2 and C for conducting H2 and at least one C-containing molecule into yet another processing chamber of yet another SiC reactor. According to yet another preferred embodiment of the present invention, the second storage element and / or conduction element forms a section of the mass flux path for H2 and C for conducting a second fluid comprising H2 and at least one C-containing molecule into the processing chamber, and the second storage element and / or conduction element and the storage element and / or conduction element for H2 and C are preferably fluidly coupled. According to yet another preferred embodiment of the present invention, the second storage element and / or conduction element forms yet another section of the mass flux path for H2 and C for conducting a second fluid comprising H2 and at least one C-containing molecule into the processing chamber. According to yet another preferred embodiment of the present invention, yet another C mass flux measurement unit for measuring the amount of C in the second fluid is provided as part of yet another mass flux path of H2 and C in front of the processing chamber, particularly in front of the mixing device. This embodiment is beneficial because, in addition to the use of chlorosilane, H2 and at least one C-containing molecule are also recycled, thus enhancing the overall efficiency.

[0097] According to yet another preferred embodiment of the present invention, the second storage element and / or conduction element is coupled to a flare unit for combusting the second fluid.

[0098] According to yet another preferred embodiment of the present invention, a first compressor for compressing the vent gas to a pressure higher than 5 bar is provided as part of the separation unit or in the gas flow path between the gas outlet unit and the separation unit. According to yet another preferred embodiment of the present invention, another compressor for compressing the first fluid to a pressure higher than 5 bar is provided as part of another separation unit or in the gas flow path between the separation unit and another separation unit.

[0099] Another separation unit preferably comprises a cryogenic distillation unit, and according to yet another preferred embodiment of the present invention, the cryogenic distillation unit is preferably configured to operate at a temperature between -180°C and -40°C.

[0100] This embodiment is beneficial because TCS has a boiling point of 31.8°C and STC has a boiling point of 57.7°C. Having such low but substantially different boiling points allows TCS and STC to be effectively and economically separated from each other and from any heavy contaminants such as trace metals by conventional distillation methods and distillation apparatuses. On the other hand, the purification of methane from N requires more complex cryogenic distillation. The boiling point of methane is -161.6°C and the boiling point of N is -195.8°C. Thus, the distillation column can be operated at any temperature between these temperatures such that methane is liquid and progresses towards the bottom of the column and nitrogen is gaseous and progresses towards the top of the column.

[0101] According to yet another preferred embodiment of the present invention, a control unit for controlling the fluid flow of one or more feed media is part of the SiC production reactor, the plurality of feed media comprising a first medium, a second medium, and a third medium, and yet another Si feed medium and / or yet another C feed medium being supplied into the processing chamber through the gas inlet unit. Preferably, the yet another Si feed medium is composed of a chlorosilanes mixture of at least 95% (by mass), at least 98% (by mass), at least 99% (by mass), at least 99.9% (by mass), at least 99.99% (by mass), or at least 99.999% (by mass). Preferably, the yet another C feed medium comprises at least one C-containing molecule, H2, HCl, and a chlorosilanes mixture, and comprises at least 3% (by mass), preferably at least 5% (by mass), or very preferably at least 10% (by mass) of C or at least one C-containing molecule, comprises up to 10% (by mass), preferably between 0.001% (by mass) and 10% (by mass), very preferably between 1% (by mass) and 5% (by mass) of HCl, comprises more than 5% (by mass), preferably more than 10% (by mass), or very preferably more than 25% (by mass) of H2, and further comprises more than 0.01% (by mass), preferably more than 1% (by mass), very preferably between 0.001% (by mass) and 10% (by mass) of the chlorosilanes mixture.

[0102] According to yet another preferred embodiment of the present invention, a heating unit is arranged between yet another separation unit and the gas inlet unit in the fluid flow direction to heat the chlorosilanes mixture to transfer it from the liquid form to the gaseous form.

[0103] The object mentioned above is also achieved by at least the following steps: At least surrounded by a base plate, a side wall section, and an upper wall section, preferably, a source medium is provided inside a processing chamber, which is a processing chamber of a SiC generation reactor according to the present invention, at least one SiC growth substrate disposed in the processing chamber, preferably, a plurality of SiC growth substrates are electrically activated and heated to a temperature in the range between 1300 °C and 2000 °C, and in order to extract Si and C from the source medium and deposit the extracted Si and C as SiC on the SiC growth substrate, thereby forming a SiC solid preferably composed of polycrystalline SiC, in particular, setting a deposition rate higher than 200 μm / h, preferably, higher than 300 μm / h, very preferably, higher than 500 μm / h. It is solved by a PVT source material generation method for generating a PVT source material, particularly composed of polymorphic 3C SiC.

[0104] According to yet another preferred embodiment of the present invention, each SiC growth substrate includes a first power connection part and a second power connection part, the first power connection part is a first metal electrode, the second power connection part is a second metal electrode, and preferably, the first metal electrode and the second metal electrode are blocked from the reaction space of the processing chamber.

[0105] Preferably, the PVT source material generation method includes a step of preventing heating of a defined temperature of the base plate, the side wall section, and / or the upper wall section, particularly higher than 1300 °C.

[0106] This method is beneficial because it can produce ultra-high purity bulk CVD SiC. In the present invention, bulk CVD SiC means CVD SiC in an independent form and not a coating on another material. Therefore, bulk CVD SiC does not mean that "bulk" exhibits the densest properties compared to other forms of SiC such as sintered SiC. According to the present invention, SiC, particularly polycrystalline SiC, particularly 3C crystal polymorph, is produced.

[0107] It should be noted that the PVT source material generation method can instead be understood as a SiC generation method, particularly a SiC generation method implemented by a CVD reactor.

[0108] According to the present invention, the above-mentioned object is solved by a method for producing preferably elongated SiC solids of polymorph 3C according to claim 1. Preferably, the method according to the present invention comprises at least the following steps: introducing at least a first source gas comprising Si into the processing chamber, introducing at least one second source gas comprising C into the processing chamber, charging at least one deposition element arranged in the processing chamber in order to heat it, setting a deposition rate higher than 200 μm / h, and generating a pressure higher than 1 bar in the processing chamber by introducing the first source gas and / or the second source gas, and heating the surface of the deposition element to a temperature in the range between 1300 °C and 1700 °C; comprises.

[0109] This solution is beneficial because it enables very fast growth of the deposition element due to the selected parameters. This rapid growth has a significant impact on the overall cost and makes it possible to produce SiC at a significantly lower cost compared to the prior art.

[0110] According to a preferred embodiment of the present invention, the method according to the present invention preferably comprises the step of introducing at least one carrier gas comprising H into the processing chamber.

[0111] This embodiment is beneficial because it can generate a favorable gas flow in the processing chamber using the carrier gas.

[0112] According to the present invention, the above-mentioned object is solved by a method for producing preferably elongated SiC solids of polymorph 3C according to claim 3. Preferably, the method according to the present invention comprises the following steps: Introducing at least one source gas comprising Si and C, in particular a first source gas, in particular SiCl3(CH3), into the processing chamber, preferably introducing at least one carrier gas comprising H into the processing chamber, charging it to heat at least one deposition element disposed in the processing chamber, setting a deposition rate higher than 200 μm / h, and generating a pressure higher than 1 bar in the processing chamber by introducing the source gas and / or the carrier gas, and heating the surface of the deposition element to a temperature in the range between 1300 °C and 1700 °C or between 1300 °C and 1700 °C. comprises.

[0113] This solution is beneficial because it enables very fast growth of the deposition element due to the selected parameters. This rapid growth has a significant impact on the overall cost and enables SiC to be produced at a significantly lower cost compared to the prior art.

[0114] According to a preferred embodiment of the present invention, the above method further comprises introducing at least a second source gas comprising C into the processing chamber.

[0115] Another preferred embodiment of the present invention is the subject matter of the following description part and / or the dependent claims.

[0116] According to yet another preferred embodiment of the present invention, the introduction of the first source gas and / or the second source gas generates a pressure in the processing chamber between 2 bar and 10 bar, preferably between 4 bar and 8 bar, particularly preferably between 5 bar and 7 bar, especially 6 bar.

[0117] This embodiment is advantageous because the increase in pressure provides more starting materials that are deposited in the form of SiC on the deposition element or through which the deposition element grows.

[0118] According to another preferred embodiment of the present invention, the surface of the deposition element is heated to a temperature in the range between 1450 °C and 1700 °C, in particular to a temperature in the range between 1500 °C and 1600 °C or between 1490 °C and 1680 °C.

[0119] This embodiment is advantageous because it provides an environment in which very pure SiC is deposited on the deposition element. In particular, it has been recognized that at overly low temperatures, the ratio of Si deposited on the deposition element increases, and at overly high temperatures, the ratio of C deposited on the deposition element increases. However, within the temperature ranges mentioned, the SiC is the purest.

[0120] According to another preferred embodiment of the present invention, the first source gas is introduced into the processing chamber through the first supply means, the second source gas is introduced into the processing chamber through the second supply means, or the first source gas and the second source gas are mixed before being introduced into the processing chamber and then introduced into the processing chamber through the supply means, and the source gas is mixed in a molar ratio of Si:C of Si = 1 and C = 0.8 to 1.1 and / or an atomic ratio of Si:C of Si = 1 and C = 0.8 to 1.1 and introduced into the processing chamber. These ratios are advantageous because they make it possible to very precisely adjust the ratio of Si:C = 1:1 of the SiC solid material by the molar ratio of these two gases.

[0121] This embodiment is advantageous because it provides a gas composition in which very high-purity SiC is deposited on the deposition element.

[0122] According to another preferred embodiment of the present invention, the carrier gas comprises H, and the source gas and the carrier gas are present in a molar ratio of Si:C:H of Si = 1 and C = 0.8 to 1.1 and H = 2 to 10, in particular a molar ratio of Si:C:H of Si = 1 and C = 0.9 to 1 and H = 3 to 5, and / or an atomic ratio of Si:C:H of Si = 1 and C = 0.8 to 1.1 and H = 2 to 10, in particular an atomic ratio of Si:C:H of Si = 1 and C = 0.9 to 1 and H = 3 to 5, and are introduced into the processing chamber.

[0123] During deposition, preferably, the atomic ratio or molar ratio of H2:SiCl4:CH4 = 5:1:1, alternatively, H2:SiCl4:CH4 = 6:1:1, alternatively, H2:SiCl4:CH4 = 7:1:1, alternatively, H2:SiCl4:CH4 = 8:1:1, alternatively, H2:SiCl4:CH4 = 9:1:1, alternatively, H2:SiCl4:CH4 = 10:1:1 exists.

[0124] Therefore, the atomic ratio or molar ratio between H2, SiCl4, and CH4 during deposition is preferably between 5:1:1 and 10:1:1.

[0125] Preferably, the set atomic ratio or molar ratio is kept constant during deposition, which can also be applied when changing the flow rate. Particularly preferably, the total pressure or the pressure inside the processing chamber is also kept constant during deposition.

[0126] This embodiment is advantageous because it provides a gas composition for depositing very high-purity SiC on the deposition element very rapidly, and favorable gas transport is achieved within the processing chamber.

[0127] According to another preferred embodiment of the present invention, the deposition rate is set in the range between 300 μm / h and 2500 μm / h, particularly in the range between 350 μm / h and 1200 μm / h, particularly in the range between 400 μm / h and 1000 μm / h, especially between 420 μm / h and 800 μm / h.

[0128] This embodiment is advantageous because the production of the SiC material can be conveniently changed.

[0129] According to another preferred embodiment of the present invention, the first source gas is SiCl4, SiHCl3, or SiCl4, the second source gas is CH4 or C3H8, preferably, the first source gas is SiCl4 and the second source gas is CH4, or preferably, the first source gas is SiHCl3 and the second source gas is CH4, or preferably, the first source gas is SiCl4 and the second source gas is C3H8.

[0130] This embodiment is advantageous because these source gases enable an optimal supply of Si and C for deposition.

[0131] Preferably, one or more source gases and / or carrier gases have a purity of at least 99.9999% (weight ppm) of impurities, in particular excluding substances B, Al, P, Ti, V, Fe, Ni.

[0132] That is, preferably, impurities less than 1 weight ppm, in particular substances B, Al, P, Ti, V, Fe, Ni, are components of the expanding one or more gases and / or carrier gases, or impurities less than 0.1 weight ppm, in particular substances B, Al, P, Ti, V, Fe, Ni, are components of the expanding one or more gases and / or carrier gases, or admixtures less than 0.01 weight ppm, in particular substances B, Al, P, Ti, V, Fe, Ni, are compositions of the expanding one or more gases and / or carrier gases.

[0133] Particularly preferably, the substance B that is less than 1 weight ppm is a composition of one or more expanding gases and / or carrier gases. Particularly preferably, the substance Al that is less than 1 weight ppm is a composition of one or more expanding gases and / or carrier gases. Particularly preferably, the substance P that is less than 1 weight ppm is a composition of one or more expanding gases and / or carrier gases. Particularly preferably, the substance Ti that is less than 1 weight ppm is a composition of one or more source gases and / or carrier gases. Particularly preferably, the substance V that is less than 1 weight ppm is a composition of one or more expanding gases and / or carrier gases. Particularly preferably, the substance Fe that is less than 1 weight ppm is a composition of one or more expanding gases and / or carrier gases. Particularly preferably, the substance Ni that is less than 1 weight ppm is a composition of one or more expanding gases and / or carrier gases.

[0134] Particularly preferably, the substance B that is less than 0.1 weight ppm is a composition of one or more expanding gases and / or carrier gases. Particularly preferably, the substance Al that is less than 0.1 weight ppm is a composition of one or more source gases and / or carrier gases. Particularly preferably, the substance P that is less than 0.1 weight ppm is a composition of one or more expanding gases and / or carrier gases. Particularly preferably, the substance Ti that is less than 0.1 weight ppm is a composition of one or more source gases and / or carrier gases. Particularly preferably, the substance V that is less than 0.1 weight ppm is a composition of one or more expanding gases and / or carrier gases. Particularly preferably, the substance Fe that is less than 0.1 weight ppm is a composition of one or more source gases and / or carrier gases. Particularly preferably, the substance Ni that is less than 0.1 weight ppm is a composition of one or more source gases and / or carrier gases.

[0135] Particularly preferably, the substance B that is less than 0.01 weight ppm is a composition of one or more source gases and / or carrier gases. Particularly preferably, the substance Al that is less than 0.01 weight ppm is a composition of one or more source gases and / or carrier gases. Particularly preferably, the substance P that is less than 0.01 weight ppm is a composition of one or more source gases and / or carrier gases. Particularly preferably, the substance Ti that is less than 0.01 weight ppm is a composition of one or more source gases and / or carrier gases. Particularly preferably, the substance V that is less than 0.01 weight ppm is a composition of one or more source gases and / or carrier gases. Particularly preferably, the substance Fe that is less than 0.01 weight ppm is a composition of one or more source gases and / or carrier gases. Particularly preferably, the substance Ni that is less than 0.01 weight ppm is a composition of one or more source gases and / or carrier gases. Particularly preferably, the nitrogen (N) of the substance that is less than 1 weight ppm is a composition of one or more source gases and / or carrier gases.

[0136] According to yet another preferred embodiment of the present invention, the surface temperature of the deposition element is measured using a temperature measuring device, particularly a pyrometer. Preferably, the temperature measuring device outputs a temperature signal and / or temperature data. Particularly preferably, the control device modifies, particularly increases, the electrical load of the separation element as a function of the temperature signal and / or temperature data.

[0137] This embodiment is advantageous because it can compensate for the adverse effects resulting from growth. In particular, as a result of the formation or deposition of SiC, the mass of the deposition element increases, and as a result, the temperature of the deposition element changes, particularly decreases, at the same electrical load. This temperature decrease is considered to result in an increase in the Si content. By modifying the electrical application, particularly increasing it, particularly increasing the current amount, the temperature change can be compensated for or reversed.

[0138] According to yet another preferred embodiment of the present invention, the temperature measurement device performs temperature measurement in a period shorter than 5 minutes, particularly shorter than 3 minutes, or shorter than 2 minutes, or shorter than 1 minute, or shorter than 30 seconds to output a temperature signal and / or temperature data. Preferably, a target temperature or a target temperature range is defined. Preferably, the control device controls an increase in the electrical application as soon as the temperature signal and / or temperature data represents a surface temperature lower than a defined threshold temperature. Thus, the threshold temperature is a temperature that is lower than the set temperature by a predetermined value or the lower limit of the set temperature range. Preferably, the predetermined value is lower than 10 °C, or lower than 5 °C, or lower than 3 °C, or lower than 2 °C, or lower than 1.5 °C, or lower than 1 °C.

[0139] This embodiment is advantageous because it can detect, compensate for, or reverse very precise temperature changes. As a result, it can bring about very high purity. With this very high purity, preferably, the current amount or current intensity can increase by up to 1.1 times, 1.5 times, 1.8 times, 2 times, 2.3 times, 2.5 times, 2.8 times, 3 times, 3.5 times, 5 times, or 10 times over the deposition period. With this very high purity, preferably, the current amount or current intensity can increase by at least 1.1 times, 1.5 times, 1.8 times, 2 times, 2.3 times, 2.5 times, 2.8 times, 3 times, 3.5 times, 5 times, or 10 times over the deposition period.

[0140] According to yet another preferred embodiment of the present invention, more amount per unit time of a source gas, particularly a first source gas and / or a second source gas, is introduced continuously or stepwise into the processing chamber, particularly in a defined ratio. Preferably, more source gas, particularly a first source gas and / or a second source gas, is introduced into the processing chamber as a function of time and / or as a function of the electrical load.

[0141] This embodiment is advantageous because it can adapt the mass of the source gas to the surface increase of the deposition element. As a result, preferably, an optimal amount (mass) of Si and C can be maintained in the processing chamber throughout the production process.

[0142] The object mentioned above is also solved, in particular for the purpose of producing preferably elongated SiC solids of polytype 3C, by a device for carrying out the method described above in accordance with claim 12. Preferably, this device according to the invention comprises at least one processing chamber for receiving a chargeable deposition element, a first source gas comprising Si, a second source gas comprising C, a first supply device and / or a second supply device, first supply means and / or second supply means for introducing the first source gas and / or the second source gas into the processing chamber at a pressure higher than 1 bar, temperature measuring means for measuring the surface temperature of the deposition element, and control means for setting a deposition rate higher than 200 μm / h. Preferably, the control device can adjust the electrical application to a separating element which can be adjusted from 1300 °C to 1700 °C in order to generate the surface temperature.

[0143] The object mentioned above is also solved, in particular for the purpose of producing preferably elongated SiC solids of polytype 3C, by a device for carrying out the method described above in accordance with claim 13. Preferably, this device according to the invention comprises at least one processing chamber for receiving a chargeable deposition element, at least one source gas comprising Si and C, in particular SiCl3(CH3) and preferably a carrier gas comprising H, first supply means and / or second supply means for introducing the source gas and / or the carrier gas into the processing chamber at a pressure higher than 1 bar, temperature measuring means for measuring the surface temperature of the deposition element, and control means for setting a deposition rate higher than 200 μm / h. Preferably, the control means has the function of adjusting the electrical application to a separating element which can be adjusted from 1300 °C to 1700 °C in order to bring about the surface temperature.

[0144] Particularly preferably, in all embodiments, the separation elements described within the scope of the present invention are preferably composed of graphite, carbon, or SiC, or are preferably elongated bodies having graphite or carbon and / or SiC. It is also possible to manufacture the separation element from graphite or carbon and to arrange or cover it with a SiC plate having a thickness of particularly less than 5 mm or less than 2 mm or less than 1 mm or less than 0.1 mm. Instead of this, it is also possible to grow a SiC layer on the graphite. The SiC plate and / or the SiC growth layer can be, for example, single-crystalline or polycrystalline. Preferably, the deposition element is coupled to the first electrical contact in the region of the first end of its longitudinal extension, particularly at a location closer to the first end of the longitudinal extension than to the second end of the longitudinal extension. In addition to this, preferably, the deposition element is coupled to the first electrical contact in the region of the second end of its longitudinal extension, particularly at a location closer to the second end of the longitudinal extension than to the first end of the longitudinal extension. Preferably, in order to heat the separation element, an electric current is introduced into the separation element through one of these two contacts and discharged from the separation element through the other contact.

[0145] Furthermore, the above-mentioned object is solved by a SiC solid-state material having a purity of at least or exactly 99.9999% (weight ppm) excluding the substances B, Al, P, Ti, V, Fe, Ni according to claim 14 and / or a density of 3.21 g / cm3, particularly a 3C-SiC solid-state material.

[0146] Preferably, the SiC solid material or the deposition element (after the end of the deposition process) has a diameter of at least or exactly 4 inches, at least or exactly or at most 6 inches, at least or exactly or at most 8 inches, or at least or exactly or at most 10 inches.

[0147] Preferably, the SiC solid-state material according to the present invention is produced by the method according to any one of claims 1 to 11. Preferably, the SiC solid-state material has a purity excluding substances B, Al, P, Ti, V, Fe, Ni of at least 99.9999% (weight ppm). Thus, preferably, substances B, Al, P, Ti, V, Fe, Ni that are less than 1 weight ppm or less than 0.1 weight ppm or less than 0.01 weight ppm are part of the SiC solid material.

[0148] Particularly preferred is a substance B component in the SiC material that is less than 1 weight ppm. Particularly preferred is a substance Al component in the SiC material that is less than 1 weight ppm. Particularly preferred is a substance P component in the SiC material that is less than 1 weight ppm. Particularly preferred is a substance Ti component in the SiC material that is less than 1 weight ppm. Particularly preferred is a substance V component in the SiC material that is less than 1 weight ppm. Particularly preferred is a substance Fe component in the SiC material that is less than 1 weight ppm. Particularly preferred is a substance Ni component in the SiC material that is less than 1 weight ppm.

[0149] Particularly preferred is a substance B component in the SiC material that is less than 1 weight ppm. Particularly preferred is a substance Al component in the SiC material that is less than 1 weight ppm. Particularly preferred is a substance P component in the SiC material that is less than 1 weight ppm. Particularly preferred is a substance Ti component in the SiC material that is less than 1 weight ppm. Particularly preferred is a substance V component in the SiC material that is less than 1 weight ppm. Particularly preferred is a substance Fe component in the SiC material that is less than 1 weight ppm. Particularly preferred is a substance Ni component in the SiC material that is less than 1 weight ppm.

[0150] Particularly preferred is a component B of a substance that is less than 0.1 weight ppm of the SiC material. Particularly preferred is a component Al of a substance that is less than 0.1 weight ppm of the SiC material. Particularly preferably, a substance P that is less than 0.1 weight ppm is a composition of the SiC material. Particularly preferred is a component Ti of a substance that is less than 0.1 weight ppm of the SiC material. Particularly preferably, a substance V that is less than 0.1 weight ppm is a composition of the SiC material. Particularly preferred is a component Fe of a substance that is less than 0.1 weight ppm of the SiC material. Particularly preferred is a component Ni of a substance that is less than 0.1 weight ppm of the SiC material.

[0151] Particularly preferred is a component B of a substance that is less than 0.01 weight ppm of the SiC material. Particularly preferred is a component Al of a substance that is less than 0.01 weight ppm of the SiC material. Particularly preferably, a substance P that is less than 0.01 weight ppm is a composition of the SiC material. Particularly preferred is a component Ti of a substance that is less than 0.01 weight ppm of the SiC material. Particularly preferably, a substance V that is less than 0.01 weight ppm is a composition of the SiC material. Particularly preferred is a component Fe of a substance that is less than 0.01 weight ppm of the SiC material. Particularly preferably, a substance Ni that is less than 0.01 weight ppm is a composition of the SiC material.

[0152] In the context of this patent specification, it is preferably understood that ppm is weight ppm.

[0153] In addition to this, since nitrogen is incorporated into the PVT SiC crystal from the SiC source material and changes the electrical properties, a low nitrogen (N) content is preferred. In some cases, during the PVT process, the SiC crystal is doped with nitrogen, and this doping is preferably carried out by the addition of N gas during the PVT process. Even in this case, a high nitrogen content in the source material may result in a non-uniform nitrogen distribution within the SiC crystal. Therefore, according to the present invention, it is also beneficial to keep the nitrogen content of the SiC source material at a very low level.

[0154] This is solved by using a source gas of specifically defined quality by the method of this description according to the invention. Thus, the resulting SiC source material has an elemental N content of less than 30,000 ppba (atomic), which almost corresponds to less than 10.5 ppm (by weight) when measured by elemental analysis.

[0155] Particularly preferably, the substance N is less than 10 ppm by weight and is a composition of the SiC material.

[0156] Particularly preferably, the substance N is lower than 2000 ppm by weight and is a composition of the SiC material.

[0157] Particularly preferably, the substance N is lower than 1000 ppm by weight and is a composition of the SiC material.

[0158] Particularly preferably, the substance N is lower than 500 ppm by weight and is a composition of the SiC material.

[0159] In addition to this, the invention mentioned above also further suppresses other impurities of many other elements. Table 1 below shows typical measurement results using glow discharge mass spectrometry.

[0160]

Table 1

[0161] Table 1 above shows the impurity levels of one SiC sample produced by the invention and measured by glow discharge mass spectrometry. In particular, the elements Na, Mg, S, K, Ca, and Pb have concentrations less than 0.1 ppm by weight, which is advantageous according to the purity of the SiC of the invention.

[0162]

Table 2

[0163] Table 2 above shows the elemental analysis of different SiC samples generated using different processing parameters by the method according to the present invention. The nitrogen content is indeterminate and can be kept below 1 weight ppm in all cases. In particular, the nitrogen content can be kept below 100 weight ppb under more favorable process conditions.

[0164] Furthermore, the object mentioned above is solved by using the SiC solid state material according to claim 14 in a PVT reactor for producing single crystal SiC.

[0165] Furthermore, the object mentioned above is solved by using the above-mentioned SiC solid state material or the SiC solid state material according to claim 14 in a PVT (PVT = Physical Vapor Transport) reactor for the production of single crystal SiC.

[0166] This solution is advantageous because the high-purity SiC solid state material provides a very advantageous starting material for the PVT process. On the other hand, this material is advantageous because it is available as a solid state block. Next, this solid block can be crushed into fragments having a defined minimum size, mass, or volume. Preferably, at least 50 (weight)%, at least 70 (weight)%, at least 80 (weight)%, at least 90 (weight)%, or at least 950 (weight)% of the SiC solid material is broken into fragments having a volume greater than 0.5 cm3, or greater than 1 cm3, or greater than 1.5 cm3, or 2 cm3 or 5 cm3.

[0167] Alternatively, the solid block can be divided, in particular split or sawn, into a plurality of preferably at least substantially equal small pieces, in particular at right angles to the longitudinal axis or the direction of extension of the solid block. Preferably, the divided small pieces are flakes having a minimum thickness of 0.5 cm, 1 cm, 3 cm, or 5 cm and in particular a thickness of at most 20 cm, 30 cm, or 50 cm. In both cases (crushing or dividing), solids with a minimum size can be provided. The supply of solids of these sizes enables a much more uniform temperature distribution within the starting material during heating of the SiC solid material (starting material) compared to the ultrafine starting material for the PVT process, resulting in a much more uniform evaporation of the starting material. Furthermore, in the case of the ultrafine starting material, relative movement between the individual material fragments occurs due to the increasing vapor and material extraction at the individual material fragments, resulting in a turbulent flow that adversely affects the crystal growth process. These drawbacks are eliminated by using larger fragments or pieces.

[0168] This solution is further advantageous in that the total surface area is significantly smaller than when ultrafine materials are used due to the larger fragments or pieces. Thus, the total surface area is determined as a parameter for adjustment during the PVT process and is easy to use.

[0169] This solution is further advantageous in that it can cause a more rapid transition of the boundary layer forming the surface of the solid-state material due to the low density of the SiC solid-state material produced according to the invention.

[0170] The SiC solid-state material produced by the present invention, particularly the 3C-SiC solid-state material, is preferably introduced into a reactor, furnace device, or PVT reactor having at least the following characteristics described below. Such a new reactor is preferably a reactor or PVT reactor for crystal growth, particularly for SiC crystal growth. This reactor or furnace device further comprises at least one or two or more or exactly one crucible or crucible unit, and at least one crucible or crucible unit is arranged in the furnace volume. The crucible or crucible unit comprises, has, or forms a crucible housing that forms a housing having an outer surface and an inner surface that at least partially defines the crucible volume. An acceptance space for receiving starting materials is arranged or formed in the crucible volume. Preferably, a seed holder unit for receiving a defined seed wafer 18 is also provided, particularly arranged in the crucible volume, or such a seed holder unit is arrangeable in the crucible volume. The reactor or oven device further has at least one heating unit for heating the starting materials and / or the crucible housing of the crucible unit. When a seed holder unit is provided, the acceptance space for receiving the starting materials is preferably arranged at least partially between the heating unit and the seed holder unit.

[0171] This oven device is advantageous in that it can be modified in one or more ways to resolve at least one or some or all of the purposes mentioned above.

[0172] Yet another preferred embodiment is the subject matter of yet another specification part and / or the dependent claims.

[0173] According to a preferred embodiment of the present invention, the furnace device further includes at least one leakage prevention device for preventing leakage of silicon gas from the inside of the crucible or crucible unit into a part of the furnace volume surrounding the crucible unit during operation. This design is advantageous because the drawback of easily leaking Si vapor is eliminated.

[0174] According to another preferred embodiment of the present invention, the leak prevention agent is selected from the group of leak prevention agents. Preferably, the group of leak prevention means includes at least (a) a cover element for covering a plurality of surface portions and / or a density increasing element for increasing the density of the volume section of the crucible housing of the crucible unit, (b) a filter unit for recovering Si gas, and / or (c) a pressure unit for establishing a first pressure inside the crucible unit and establishing a second pressure higher than the first pressure outside the crucible unit but inside the furnace, and (d) a seal disposed between the housing portions of the crucible unit. This embodiment is advantageous because several features are provided that result in an improvement of the furnace device. Such an oven device can provide one or more or all of the features of the above-described group of leak prevention means. Accordingly, the present invention further provides a solution for different products, particularly for different requirements for crystals having different properties.

[0175] According to another preferred embodiment of the present invention, the leak prevention agent reduces the leakage of sublimation vapor of Si vapor, in particular, from the crucible volume through the crucible housing into the furnace volume by at least 50% (by mass), at least 80% (by mass), at least 90% (by mass), more than 99% (by mass), or at least 99.9% (by mass). This embodiment is advantageous because components such as the crucible housing and the heating unit can be reused a plurality of times, particularly more than 10 times, or more than 20 times, or more than 50 times, or more than 100 times, due to the furnace in which the easily leaking Si vapor is significantly reduced. Accordingly, the crucible unit, the crucible housing, each section of the crucible unit, or each section of the crucible housing has a transmittance lower than 10−2 cm2 / s, or lower than 10−5 cm2 / s, or lower than 10−10 cm2 / s, particularly with respect to Si vapor.

[0176] According to yet another preferred embodiment of the present invention, in order to withstand temperatures higher than 2000 °C, in particular at least or up to 3000 °C, or at least up to 3000 °C, or up to 3500 °C, or at least up to 3500 °C, or up to 4000 °C, or at least up to 4000 °C, the crucible housing comprises carbon, in particular at least 50% (by mass) of the crucible housing is composed of carbon, preferably at least 80% (by mass) of the crucible housing is composed of carbon, most preferably at least 90% (by mass) or the whole of the crucible housing is composed of carbon, in particular the crucible housing comprises at least 90% (by mass) of graphite or is composed of graphite. Preferably, the crucible housing is impermeable to silicon gas (Si vapor). This design is advantageous because it prevents Si vapor from penetrating through the crucible housing and damaging the crucible housing and the components outside it. In addition to or instead of this, the crucible unit, the crucible housing structure, or the crucible housing has glassy carbon-coated graphite, solid glassy carbon, pyrocarbon-coated graphite, tantalum carbide-coated graphite, and / or solid tantalum carbide.

[0177] According to another preferred embodiment of the present invention, the leakage prevention means is a cover element for covering the surface of the housing, in particular the inner surface and / or the outer surface, or a plurality of surface portions of the housing, in particular a plurality of surface portions of the inner surface of the housing and / or a plurality of surface portions of the outer surface of the housing. This embodiment is advantageous because the cover element can be generated on the surface of the housing or attached to the surface of the housing. On the other hand, either of these two steps (generation step / attachment step) can be implemented using a cost-effective and highly reliable method.

[0178] According to another preferred embodiment of the present invention, the cover element is a sealing element, and the sealing element is a coating. Preferably, the coating reduces the leakage of sublimation vapor, especially Si vapor, which is generated during the process and enters the furnace volume from the crucible volume through the crucible housing, by at least 50% (mass), at least 80% (mass), at least 90% (mass), more than 99% (mass), or at least 99.9% (mass). It is composed of a material or a combination thereof.

[0179] Preferably, the coating withstands a temperature higher than 2000 °C, especially at least or up to 3000 °C, or at least up to 3000 °C, or up to 3500 °C, or at least up to 3500 °C, or up to 4000 °C, or at least up to 4000 °C. This embodiment is advantageous because the modified crucible unit has at least two material layers, one layer forms the crucible outer skin, and the other layer reduces the permeability of Si vapor. Most preferably, the coating comprises one or more materials selected from the group of materials comprising at least carbon, especially pyrolytic carbon and vitreous carbon. Therefore, the crucible unit, especially the crucible housing or the housing of the crucible unit, is preferably coated with pyrolytic carbon and / or vitreous carbon. Preferably, the pyrolytic carbon layer has a thickness greater than 10 μm or up to 10 μm, especially greater than 20 μm or up to 20 μm, greater than 50 μm or up to 50 μm, greater than 100 μm or up to 100 μm, greater than 200 μm or up to 200 μm, or greater than 500 μm or up to 500 μm. Preferably, the vitreous carbon layer has a thickness greater than 10 μm or up to 10 μm, especially greater than 20 μm or up to 20 μm, greater than 50 μm or up to 50 μm, greater than 100 μm or up to 100 μm, greater than 100 μm or up to 100 μm, greater than 200 μm or up to 200 μm, or greater than 500 μm or up to 500 μm.

[0180] According to yet another preferred embodiment, the coating is produced by chemical vapor deposition or is produced in particular by printing phenolic formaldehyde on a precursor material and subsequent pyrolysis. This embodiment is advantageous since the coating can be generated in a reliable manner.

[0181] According to another preferred embodiment of the present invention, the leak prevention agent is a density increasing element or a sealing element for increasing the density of the volume portion of the crucible housing of the crucible unit, the density increasing element being arranged or achieved in the internal structure of the crucible housing, and the density increasing element being a sealing element. The coating is generated during the process and prevents the leakage of sublimation vapor, in particular Si vapor, which enters from the crucible volume through the crucible housing into the furnace volume, by at least 50% (by mass), at least 80% (by mass), at least 90% (by mass), more than 99% (by mass), or at least 99.9% (by mass). This embodiment is advantageous since the dimensions of the crucible unit remain the same or similar or are not affected by the modification. Preferably, the sealing element is achieved by impregnation or deposition on the inside of the crucible housing.

[0182] According to another preferred embodiment of the present invention, the leakage prevention means is a filter unit for recovering Si gas. The filter unit includes a filter body, and the filter body has a filter input surface or filter input section for introducing a gas containing SiC chemical species vapor, Si vapor, and a processing gas into the filter body, and an output section or filter output surface for outputting the filtered processing gas. Between the filter input surface and the filter output surface, filter elements are arranged to form a capture section for adsorbing and condensing SiC chemical species vapor, particularly Si vapor. Therefore, preferably, the material of the filter is adapted to cause absorption and condensation of Si vapor on its surface. This design is advantageous because the total amount of Si vapor inside the crucible unit can be significantly reduced using the filter unit. This also significantly reduces the amount of Si vapor that may leak. Most preferably, all of the Si vapor is preferably recovered as a condensate film on the inner surface of the filter. In addition to or instead of this, a section where the temperature is below the melting point of Si and the vapor condensate actually solidifies is defined within the uppermost part of the filter. Preferably, the Si vapor does not solidify into particles, and preferably a solid film is formed on the inner surface of the filter. This film may be amorphous or polycrystalline. The excess vapor of Si2C and SiC2 preferably also reaches the lower region of the filter and is preferably deposited as a solid polycrystalline deposit on its inner surface.

[0183] According to a preferred embodiment of the present invention, the filter element forms or defines a gas flow path from the inlet surface to the outlet surface of the filter. The filter element has a height S1, and the gas flow path through the filter element has a length S2, where S2 is preferably at least 10 times longer than S1, in particular at least 100 times longer than S1, or at least or at most 1000 times longer than S1, or at least or at most 10000 times longer than S1. This embodiment is advantageous because the filter unit absorbs or captures more than or at most 50% (by mass), in particular more than or at most 50% (by mass), more than or at most 70% (by mass), more than or at most 90% (by mass), more than or at most 95% (by mass), more than or at most 99% (by mass) of the Si vapor generated by the evaporation of raw materials, especially raw materials used or required during operation. Preferably, "one operation" means the generation or production of crystals, especially SiC crystals, SiC blocks, or SiC boules.

[0184] According to another preferred embodiment of the present invention, the filter unit is arranged between a first part of the crucible unit housing and a second part of the crucible unit housing, in particular a crucible lid or a filter lid. At least 50% (by volume), in particular at least 80% (by volume), or at least 90% (by volume) of the first part of the crucible unit housing is arranged vertically below the seed holder unit, and a first crucible volume exists between the first part of the crucible unit housing and the seed holder, and at least 80%, preferably 90%, or more preferably 100% of the first crucible volume can be operated to be higher than the condensation temperature Tc of silicon under normal pressure. Further, at most 50% (by volume), at most 20% (by volume), or at most 10% (by volume) of the first part of the crucible unit housing is arranged vertically above the seed holder unit. Instead of this, at least 50% (by volume), in particular at least 80% (by volume) or 90% (by volume) of the first housing part of the crucible unit is arranged vertically above the seed holder unit. Preferably, a second crucible volume is arranged between the second part of the crucible unit housing and the seed holder unit. At least 60%, preferably 80%, or more preferably 90% of the filter elements are lower than the condensation temperature Tc. Therefore, the thermal conditions in the filter elements of the filter unit enable the condensation of Si vapor. Therefore, the filter elements can very substantially condense or capture Si.

[0185] According to another preferred embodiment of the present invention, the filter unit is arranged between a first wall part of the first part of the housing and yet another wall part of the second part of the housing, the filter body forms a filter outer surface, the filter outer surface connects the first wall part of the first part of the housing and yet another wall part of the second part of the housing, and the filter outer surface forms part of the outer surface of this cross-linking unit. This embodiment is advantageous because a large-sized filter unit can be used without increasing the amount of material of the crucible housing of the crucible unit.

[0186] According to another preferred embodiment of the present invention, the filter outer surface comprises a filter surface covering element. The filter surface covering element is preferably a sealing element, and the sealing element is preferably a coating, and the coating is preferably generated on the filter surface, or attached to the filter surface, or forms the filter surface. Preferably, the coating reduces the leakage of sublimated vapor, especially Si vapor, which occurs during the process and enters the furnace volume through the crucible volume into the crucible housing, by at least 50% (by mass), at least 80% (by mass), at least 90% (by mass), more than 99% (by mass), or at least 99.9% (by mass). The coating withstands temperatures higher than 2000 °C, especially at least or up to 3000 °C, or at least up to 3000 °C, or up to 3500 °C, or at least up to 3500 °C, or up to 4000 °C, or at least up to 4000 °C.

[0187] The coating has one or more materials selected from the group of materials comprising at least carbon, especially pyrolytic carbon and vitreous carbon. Thus, preferably, the coating is a glass-carbon coating, a pyrolytic carbon coating, a glass-carbon undercoat and a pyrolytic carbon topcoat, or a pyrolytic carbon undercoat and a glass-carbon topcoat. Thus, the filter unit, especially its outer surface, is preferably coated with pyrolytic carbon and / or vitreous carbon. Preferably, the pyrolytic carbon layer has a thickness greater than 10 μm or up to 10 μm, especially greater than 20 μm or up to 20 μm, greater than 50 μm or up to 50 μm, greater than 100 μm or up to 100 μm, greater than 200 μm or up to 200 μm, or greater than 500 μm or up to 500 μm. Preferably, the vitreous carbon layer has a thickness greater than 10 μm or up to 10 μm, especially greater than 20 μm or up to 20 μm, greater than 50 μm or up to 50 μm, greater than 100 μm or up to 100 μm, greater than 200 μm or up to 200 μm, or greater than 500 μm or up to 500 μm.

[0188] According to another preferred embodiment of the present invention, the filter body forms an inner filter surface. The inner filter surface or the inner filter surface is preferably arranged coaxially with the outer filter surface. The filter body preferably has an annular shape. The outer filter surface preferably has a cylindrical shape, and / or the inner filter surface preferably has a cylindrical shape. The outer filter surface and the inner filter surface extend in the vertical direction. This embodiment is advantageous because it can be used for a filter unit in a circular crucible unit and / or a crucible unit having a circular crucible volume. Therefore, neither the filter unit nor the furnace device in which it is located requires any substantial modification, and thus the furnace device according to the present invention can be manufactured at low cost.

[0189] According to yet another preferred embodiment of the present invention, the inner filter surface further comprises another inner filter surface covering element. The another inner filter surface covering element is preferably a sealing element, and the sealing element is preferably a coating. Preferably, the coating is coated on the filter surface, or attached to the filter surface, or forms the filter surface. Preferably, the coating is a material or a combination thereof that reduces the leakage of sublimated vapor, particularly Si vapor, generated during the process and reaching from the crucible volume through the crucible housing into the furnace volume by at least 50% (by mass), at least 80% (by mass), at least 90% (by mass), more than 99% (by mass), or at least 99.9% (by mass).

[0190] Preferably, the coating withstands a temperature higher than 2000 °C, in particular higher than 2200 °C, or higher than 2000 °C, in particular at least or at most 3000 °C, or at least at most 3000 °C, at most 3500 °C, at least at most 3500 °C, at most 4000 °C, or at least at most 4000 °C. Preferably, the coating has one or more materials selected from the group of materials comprising at least carbon, in particular pyrolytic carbon and vitreous carbon. Thus, the filter unit, in particular its inner surface, is preferably coated with pyrolytic carbon and / or vitreous carbon. Preferably, the pyrolytic carbon layer has a thickness greater than 10 μm or at most 10 μm, in particular greater than 20 μm or at most 20 μm, greater than 50 μm or at most 50 μm, greater than 100 μm or at most 100 μm, greater than 200 μm or at most 200 μm, or greater than 500 μm or at most 500 μm. Preferably, the vitreous carbon layer has a thickness greater than 10 μm or at most 10 μm, in particular greater than 20 μm or at most 20 μm, greater than 50 μm or at most 50 μm, greater than 100 μm or at most 100 μm, greater than 200 μm or at most 200 μm, or greater than 500 μm or at most 500 μm.

[0191] According to another preferred embodiment of the present invention, the filter element comprises a filter element member comprising filter particles and a binder. The filter particles comprise or are composed of carbon, and the binder holds the filter particles in a fixed relative position to each other. The filter particles withstand a temperature higher than 2000 °C, in particular higher than 2000 °C, in particular higher than 2000 °C, in particular at least or at most 3000 °C, or at least at most 3000 °C, at most 3500 °C, at least at most 3500 °C, at most 4000 °C, or at least at most 4000 °C. The binder withstands a temperature higher than 2000 °C, in particular 2000 °C, in particular at least or at most 3000 °C, or at least at most 3000 °C, or at most 3500 °C, or at least at most 3500 °C, or at most 4000 °C, or at least at most 4000 °C. This embodiment is advantageous because it provides a filter unit that can withstand the conditions within the crucible unit during operation of the furnace device. Furthermore, the combination of the filter particles and the binder forms an area that is substantially larger, in particular at most or at least 10 times, at most or at least 100 times, at most or at least 1000 times, or at most or at least 10000 times larger compared to the outer surface area of the filter unit. This embodiment is further advantageous in that the filter unit has the function of absorbing or incorporating more than 50% (by mass) or at most 50% (by mass), in particular more than 50% (by mass) or at most 50% (by mass), more than 70% (by mass) or at most 70% (by mass), more than 90% (by mass) or at most 90% (by mass), more than 95% (by mass) or at most 95% (by mass), more than 99% (by mass) or at most 99% (by mass) of the Si vapor generated by the evaporation of the starting material, in particular the starting material required for each pass in one pass.

[0192] According to another preferred embodiment of the present invention, the binder comprises starch or modified starch.

[0193] This embodiment is advantageous because the binder can withstand temperatures higher than 2000 °C, in particular higher than or up to 2000 °C, in particular at least or up to 3000 °C, or at least up to 3000 °C, up to 3500 °C, at least up to 3500 °C, up to 4000 °C, or at least up to 4000 °C. The binder can withstand temperatures higher than 2000 °C, in particular 2000 °C, in particular at least or up to 3000 °C, or at least up to 3000 °C, up to 3500 °C, at least up to 3500 °C, up to 4000 °C, or at least up to 4000 °C.

[0194] According to yet another preferred embodiment of the present invention, the gas inlet is arranged between the receiving space and the seed holder unit. Preferably, the gas inlet is arranged closer to the receiving space than the seed holder unit in the vertical direction. In particular, the vertical distance between the seed holder unit and the gas inlet is preferably greater than twice the vertical distance between the receiving space and the gas inlet, in particular greater than five times the vertical distance between the receiving space and the gas inlet, or greater than eight times the vertical distance between the receiving space and the gas inlet, or greater than ten times the vertical distance between the receiving space and the gas inlet, or greater than twenty times the vertical distance between the receiving space and the gas inlet. This embodiment is advantageous because it can establish a gas flow that allows the vapor of the starting material to reach the seed wafer 18 or the crystal growth front evenly.

[0195] According to yet another preferred embodiment of the present invention, the gas inlet is covered by a gas guiding element or a gas distributing element. Preferably, the gas distributing element extends parallel to the bottom surface of the crucible unit, in particular the inner bottom surface of the crucible unit. In addition to or instead of this, the gas distributing element extends in a horizontal plane. This embodiment is advantageous because it can evenly distribute the introduced gas to the annular receiving space and thus to the starting material present in the receiving space or the vapor of the starting material flowing out of the receiving space. The evaporated raw material moves by thermally driven diffusion. In addition to or instead of this, the evaporated raw material moves by the convection of the injected gas, in particular Ar and / or N2.

[0196] According to yet another preferred embodiment of the present invention, the gas distribution element is arranged at a defined distance from the bottom surface of the crucible unit, in particular from the inner bottom surface of the crucible unit. The defined vertical distance between the bottom side of the gas distribution element and the bottom surface of the crucible unit is preferably less than 0.5×, i.e., shorter than half of the vertical distance between the receiving space and the gas inlet, or shorter than 0.3× of the vertical distance between the receiving space and the gas inlet, or shorter than 0.1× of the vertical distance between the receiving space and the gas inlet, or shorter than 0.05× of the vertical distance between the receiving space and the gas inlet.

[0197] According to another preferred embodiment of the present invention, the gas distribution element is a gas baffle. Preferably, the gas baffle forms a lower surface and an upper surface. Preferably, the lower surface and the upper surface extend parallel to each other at least for each section. Preferably, the distance between the lower surface and the upper surface is shorter than 0.5× of the distance between the receiving space and the gas inlet, or shorter than 0.3× of the distance between the receiving space and the gas inlet, or shorter than 0.1× of the distance between the receiving space and the gas inlet, or shorter than 0.05× of the distance between the receiving space and the gas inlet. This embodiment is advantageous because a truly thin gas distribution plate can be used. This thin gas distribution plate is advantageous because it does not require a large amount of material. Further, this gas distribution plate does not affect the radiant heat radiated from the lower portion covered thereby.

[0198] According to another preferred embodiment of the present invention, the means for preventing leakage is a pressure unit for establishing a first pressure inside the crucible unit and a second pressure higher than the first pressure inside the furnace but outside the crucible unit. The second pressure is below 200 Torr, in particular below 100 Torr, or below 50 Torr, in particular between 0.01 Torr and 30 Torr. Preferably, the second pressure is at most 10 Torr, at most 20 Torr, at most 50 Torr, at most 100 Torr, or at most 180 Torr higher than the first pressure. This embodiment is advantageous because the leakage of Si vapor is prevented due to the higher pressure around the crucible unit.

[0199] According to another preferred embodiment of the present invention, the pipe system is part of a furnace device. Preferably, the pipe system comprises a first pipe or crucible pipe connecting the crucible volume to the vacuum unit and a second pipe or furnace pipe connecting the part of the furnace surrounding the crucible unit to the vacuum unit. Preferably, the vacuum unit has a control element for controlling the pressure inside the crucible volume and the pressure inside the part of the furnace surrounding the crucible unit. Preferably, when the control element determines that the pressure inside the crucible volume exceeds a first threshold value and / or the pressure inside the part of the furnace surrounding the crucible unit exceeds a second threshold value, the vacuum unit reduces the pressure inside the crucible volume through the crucible tube or the pressure inside the part of the furnace surrounding the crucible unit through the furnace tube. This embodiment is advantageous because it can reliably maintain the pressure difference between the pressure inside the crucible volume and the pressure inside the furnace and around the crucible volume.

[0200] According to another preferred embodiment of the present invention, the furnace system comprises two or more leakage prevention means selected from the group consisting of leakage prevention means. This embodiment is advantageous because the furnace device can comprise at least a cover element and / or a density increasing element and a filter unit for collecting Si gas, the furnace device can comprise at least a cover element and / or a density increasing element and a pressure unit for establishing a first pressure inside the crucible unit and a second pressure inside the furnace but outside the crucible unit, or the furnace device can comprise at least a pressure unit for establishing a first pressure inside the crucible unit and a second pressure inside the furnace but outside the crucible unit and a filter unit.

[0201] However, it is also possible for the furnace device to comprise at least a cover element and / or a density increasing element, a filter unit for collecting Si gas, and a pressure unit for setting a first pressure inside the crucible unit and a second pressure inside the furnace but outside the crucible unit.

[0202] This embodiment is advantageous because the leakage of Si vapor can be prevented in various ways so that the furnace unit according to the invention can meet requirements depending on various needs.

[0203] According to yet another preferred embodiment of the invention, the heating unit comprises at least one particularly horizontal heating element, which is arranged below the receiving space in the vertical direction. Thus, preferably, the heating element at least partially, preferably mostly or completely overlaps the receiving space. This design is advantageous because the receiving space and the crucible volume or the part of the crucible housing surrounded by the receiving space can be heated from below the crucible volume. This heating from below is advantageous because the height of the receiving space and the height of the crucible volume or the part of the crucible housing surrounded by the receiving space are the same for a seed wafer 18 with a small diameter or a seed wafer 18 with a larger diameter. This enables the starting material to be heated evenly. Preferably, the heating unit further has at least one further particularly vertical heating element, and preferably the further heating element is arranged adjacent to the crucible unit, particularly adjacent to the side wall of the crucible unit surrounding the crucible unit. Preferably, the heating element and / or the further heating element is arranged inside a furnace insert outside the crucible unit, particularly outside the crucible volume.

[0204] According to yet another preferred embodiment of the invention, the receiving space is formed in a wall portion of the crucible unit or an inner wall portion or bottom portion inside the crucible unit. Preferably, the receiving space extends around a central axis, preferably coaxial with the central axis of the seed holder unit. Preferably, the receiving space is arranged at a distance defined from the central axis.

[0205] According to yet another preferred embodiment of the present invention, a gas tube or a gas guiding device for introducing gas into the crucible unit is provided. The gas tube or gas guiding means, a part of the gas tube or gas guiding means, a gas inlet attached to the gas tube or gas guiding means, or a part of the gas tube or gas guiding means is at least partially, preferably mostly or completely surrounded by the receiving space. Preferably, the gas tube or gas guiding means extends at least partially in the direction of the central axis. Preferably, the gas tube or gas conducting means enters through the bottom part of the crucible unit or the bottom part of the crucible housing of the crucible unit. This embodiment is advantageous because the gas can be supplied into the crucible volume through the gas pipeline or gas guiding device. Further, since the gas inlet is surrounded by the receiving volume, the gas introduced through the gas inlet can be particularly evenly distributed to different parts of the receiving volume. In this way, a mixture of the injected gas and the vaporized raw material can be generated in a particularly even manner.

[0206] According to another preferred embodiment of the present invention, the receiving space has an annular shape. Preferably, the receiving space is formed or shaped by a trench, particularly a circular trench or a plurality of recesses, particularly circular recesses. Preferably, these plurality of recesses are arranged along a predetermined contour, preferably circular in shape. This embodiment is advantageous because the shape of the seed wafer 18 is preferably circular. Therefore, the starting material vapor preferably approaches the growth surface of the seed wafer 18 or the growth surface of the growing crystal.

[0207] According to yet another preferred embodiment of the present invention, the defined distance between the receiving space and the central axis is at most 30%, at most 20%, at most 10%, at most 5%, or at most 1% shorter than the diameter of the defined seed wafer 18. Alternatively, the defined distance between the receiving space and the central axis is at most 1%, at most 5%, at most 10%, at most 20%, or at most 30% longer than the diameter of the defined seed wafer 18. Alternatively, the defined distance between the receiving space and the central axis coincides with the diameter of the defined seed wafer 18. This embodiment is advantageous because it further aids in the uniform distribution of the starting material vapor across the growth surface of the seed wafer 18 or across the growth surface of the growing crystal.

[0208] According to another preferred embodiment of the present invention, the receiving space surrounds the housing bottom portion or a portion above the housing bottom. The bottom section is a solid material section. Preferably, the solid material section or the thick bottom section of the crucible is greater than 0.3× the minimum distance of the receiving space from the central axis, or greater than 0.5× the minimum distance of the receiving space from the central axis, or 0.7× the minimum distance between the receiving space and the central axis, or 0.9× the minimum distance between the receiving space and the central axis, or 1.1× the minimum distance between the receiving space and the central axis, or 1.5× the height (in the vertical direction) or wall thickness of the minimum distance between the receiving space and the central axis. This design is advantageous because the lower portion or the surrounding lower portion can be heated by the heating unit. When the lower portion is heated, this heating also heats the space between the seed wafers 18 and the seed wafers 18. When the lower portion is heated, this heating also heats the space between the seed wafers 18 and the seed wafers 18. Since the lower portion is preferably a solid material block and / or a crucible-shaped solid bottom section, the heating of the space between the seed wafer 18 and the bottom section and the heating of the growth surface of the seed wafer 18 or the growing crystal are carried out in an even manner. Preferably, the bottom portion preferably has an outer surface portion that is a surface portion of the crucible body and an inner surface portion that is preferably parallel to the outer surface portion. This is advantageous because the bottom portion can be heated evenly. The inner surface portion of the bottom portion is preferably a preferably flat surface arranged in a horizontal plane. Preferably, the inner surface portion is arranged parallel to the surface of the seed wafer 18. This embodiment is advantageous because it can evenly heat the space between the seed wafer 18 and the bottom portion, as well as the growth surface of the seed wafer 18 and / or the growing crystal.

[0209] Therefore, the bottom part is arranged within the crucible volume and preferably has an inner surface parallel to the seed holder unit. The center of the inner surface and the center of the seed holder unit are preferably arranged on the same vertical axis, and the inner surface of the bottom section is preferably arranged at a distance defined from the seed holder unit. Preferably, this distance is greater than 0.5× the minimum distance between the receiving space and the central axis, or greater than 0.7× the minimum distance between the receiving space and the central axis, or greater than 0.8× the minimum distance between the receiving space and the central axis, or greater than 1× the minimum distance between the receiving space and the central axis, or greater than 1.2× the minimum distance between the receiving space and the central axis, or greater than 1.5× the minimum distance between the receiving space and the central axis, or greater than 2× the minimum distance between the receiving space and the central axis, or greater than 2.5× the minimum distance between the receiving space and the central axis. This embodiment is advantageous because large (wide and / or long) crystals can be grown.

[0210] The filter unit is arranged vertically above the receiving chamber. This embodiment is advantageous because the evaporation raw material and / or the injection gas flow from the lower crucible section to the upper crucible section, and thus preferably the filter unit is arranged in the gas flow path.

[0211] According to another preferred embodiment of the present invention, the filter unit and the receiving space are preferably arranged coaxially. This embodiment is advantageous because the starting material vapor and / or the introduced gas or a mixture of the starting material vapor and the introduced gas can preferably pass evenly through the cylindrical side wall. In this way, the deposits of the starting material vapor and / or the introduced gas can be pre-aerated. This pre-aeration is advantageous because it enables the crystals to grow uniformly. Preferably, uniform growth means that the growth rate is within a defined range at all surface parts of the crystal growth area, and / or the accumulation of defects and / or doping is evenly distributed, and the term "evenly distributed" defines an acceptable range of deviation.

[0212] According to yet another preferred embodiment of the present invention, the outer diameter of the filter unit corresponds to the outer diameter of the receiving space, and / or the inner diameter of the filter unit preferably corresponds to the inner diameter of the receiving space. This embodiment is advantageous because it does not cause any significant complexity in the shape of the housing and thus enables inexpensive manufacturing. The outer diameter of the filter unit is preferably at least or at most 1.05×, or preferably at least or at most 1.1×, or preferably at least or at most 1.3×, or preferably at least or at most 1.5× compared to the outer diameter of the receiving space. Alternatively, the outer diameter of the receiving space is preferably at least or at most 1.05×, or preferably at least or at most 1.1×, or preferably at least or at most 1.3×, or preferably at least or at most 1.5× compared to the outer diameter of the filter unit. In addition or alternatively, the inner diameter of the receiving space is preferably at least or at most 1.05× larger, or preferably at least or at most 1.1× larger, or preferably at least or at most 1.3× larger, or preferably at least or at most 1.5× larger compared to the inner diameter of the filter unit. Alternatively, the inner diameter of the filter unit is preferably at least or at most 1.05× larger, preferably at least or at most 1.1× larger, preferably at least or at most 1.3× larger, preferably at least or at most 1.5× larger compared to the inner diameter of the receiving space.

[0213] According to another preferred embodiment of the present invention, a growth guiding element for guiding the starting material vapor and / or the introduced gas into the space between the seed holder unit and the inner bottom surface of the crucible unit is arranged or provided above the vertical receiving space. This embodiment is advantageous because the growth guiding element preferably performs several functions. On the one hand, the growth guiding element guides the starting material vapor to the seed wafer 18 or the growing crystal. On the other hand, the growth guiding element affects the shape of the crystal by restricting the radial expansion of the growing crystal.

[0214] According to another preferred embodiment of the present invention, the growth guiding element comprises a first wall section or a first growth guiding section and a second wall section or a second growth guiding section. Preferably, the first growth guiding section is shaped to match the corresponding wall section of the crucible housing. Preferably, the matching in this situation means that the wall part of the crucible housing and the growth guiding member are preferably joined by a tight connection and / or a press fit connection. The second part of the growth guide is preferably shaped to manipulate the shape of the growing crystal. According to another preferred embodiment of the present invention, the first part of the growth guide and the second part of the growth guide are arranged coaxially. The first section of the growth guide is arranged at a location of a first diameter with respect to the central axis, and the second section of the growth guide is arranged at a location of a second diameter with respect to the central axis, and the first diameter is larger compared to the second diameter. The first growth guiding section and the second growth guiding section are interconnected by a third wall section and a third growth guiding section respectively, and the third growth guiding section extends at least partially horizontally. The first growth guiding section and the third growth guiding section form an arcuate section and a fourth growth guiding section respectively, and / or the second growth guiding section and the third growth guiding section are arranged at an angle between 60° and 120°, in particular between 70° and 110°, in particular at an angle of 90°. The fourth growth guiding section can have, for example, a convex shape, a concave shape, or a conical shape. The first wall section, the second section of the growth assisting device, and the third section of the growth assisting device are preferably an integral part of the growth assisting device. Preferably, the growth assisting device is made of graphite. This embodiment is advantageous because the growth guiding element has a simple but effective shape. Thus, the growth guiding element can be manufactured in a cost-effective manner.

[0215] According to another preferred embodiment of the present invention, the outer diameter of the filter unit is at least or at most 1.05× larger than the first diameter of the growth guiding element, or preferably at least or at most 1.1× larger than the first diameter of the growth guiding element, or preferably at least or at most 1.3× larger than the first diameter of the growth guiding vessel, or preferably at least or at most 1.3× larger than the first diameter of the growth guiding vessel, or preferably at least or at most 1.5× larger than the first diameter of the growth guiding vessel, and / or the second diameter of the growth guiding vessel is preferably at least or at most 1.05× larger compared to the inner diameter of the filter unit, or preferably at least or at most 1.1× larger compared to the inner diameter of the filter unit, or preferably at least or at most 1.3× larger compared to the inner diameter of the filter unit, or preferably at least or at most 1.5× larger compared to the inner diameter of the filter unit.

[0216] The upper vertical end of the growth guiding vessel of the second section of the growth guiding vessel and the seed holding unit form a gas flow channel, and the minimum distance between the upper vertical end of the growth guiding vessel of the second section of the growth guiding vessel and the seed holding unit is smaller than 0.3× of the second diameter of the growth guiding vessel, or smaller than 0.1× of the second diameter of the growth guiding vessel, or smaller than 0.08× of the second diameter of the growth guiding vessel, or smaller than 0.05× of the second diameter of the growth guiding vessel, or smaller than 0.03× of the second diameter of the growth guiding vessel, or smaller than 0.01× of the second diameter of the growth guiding vessel.

[0217] According to yet another preferred embodiment of the present invention, preferably, the coating is added to the receiving space within the crucible volume, in particular its surface, and / or to the growth guiding element, the growth guiding plate, or the gas distribution plate. Preferably, the coating has a material or a combination thereof that reduces the permeability of Si vapor through the wall portion defining the boundary of the receiving space and / or the wall portion defining the boundary of the growth guiding element to 10-3 m2 / s, preferably 10-11 m2 / s, or more preferably 10-12 m2 / s.

[0218] Preferably, the coating withstands temperatures higher than 2000 °C, in particular at least or maximally 3000 °C, or at least maximally 3000 °C, or maximally 3500 °C, or at least maximally 3500 °C, or maximally 4000 °C, or at least maximally 4000 °C. This embodiment is advantageous since the modified suppression element and / or growth guiding element has at least two material layers, one forming the structure of the suppression element and / or growth guiding element and the other reducing or avoiding the transmittance of Si vapor. Most preferably, the coating has one or more materials selected from the group of materials comprising at least carbon, in particular pyrolytic carbon and vitreous carbon. Thus, preferably, the receiving space and / or the growth conducting element is coated with pyrolytic carbon and / or vitreous carbon. Preferably, the pyrolytic carbon layer has a thickness greater than 10 μm or maximally 10 μm, in particular greater than 20 μm or maximally 20 μm, greater than 50 μm or maximally 50 μm, greater than 100 μm or maximally 100 μm, greater than 200 μm or maximally 200 μm, or greater than 500 μm or maximally 500 μm. Preferably, the vitreous carbon layer has a thickness greater than 10 μm or maximally 10 μm, in particular greater than 20 μm or maximally 20 μm, greater than 50 μm or maximally 50 μm, greater than 100 μm or maximally 100 μm, greater than 200 μm or maximally 200 μm, or greater than 500 μm or maximally 500 μm. Further, according to a preferred embodiment, the coating is produced by chemical vapor deposition or in particular by printing a precursor material, in particular phenol formaldehyde, and subsequent pyrolysis. This embodiment is advantageous since the coating can be generated in a reliable manner.

[0219] According to another preferred embodiment of the present invention, the heating unit comprises at least one heating element. Preferably, the heating element is arranged below the receiving space vertically and / or below the bottom part of the crucible unit, and the bottom part of the crucible unit is surrounded by the receiving space. This design is advantageous because the receiving space and / or the bottom section surrounded thereby can be heated by the heating element. Preferably, the heating element at least partially preferably overlaps more than 50%, more than 70%, or up to 90% at most, or completely with the receiving space and / or the bottom section surrounded thereby. This design is advantageous because an even temperature distribution can be set, and in particular an even temperature level can be generated.

[0220] According to yet another preferred embodiment of the present invention, the furnace device comprises a gas flow unit. Preferably, the gas flow unit has a gas inlet for conducting gas into the crucible unit or into the crucible volume, and a gas outlet for drawing gas out of the crucible unit or the crucible volume. Preferably, the gas inlet is arranged closer to the bottom of the crucible unit than the gas outlet. Both the gas inlet and the gas outlet are preferably arranged within the crucible volume. This design is advantageous because it can affect or control the conditions within the crucible volume, the composition of the vapor, and / or the flow (direction and / or speed) of the liquid within the crucible.

[0221] According to another preferred embodiment of the present invention, the gas outlet comprises gas conveying means, in particular a tube. Preferably, the gas outlet preferably has a sensor, in particular a temperature sensor and / or a pressure sensor, arranged inside the guiding means, in particular the tube, or arranged as part of the guiding means, in particular the tube, or attached to the outer wall of the guiding means, in particular the tube. This embodiment is advantageous because the temperature conditions and / or the pressure conditions can be monitored.

[0222] In addition to or instead of this, according to yet another preferred embodiment of the present invention, the gas inlet comprises gas conducting means, in particular a pipe. Preferably, the gas inlet preferably has a sensor, in particular a temperature sensor and / or a pressure sensor, arranged inside the conduit means, in particular the tube, or as part of the conduit means, in particular the tube, or attached to the outer wall of the conduit means, in particular the tube. This embodiment is advantageous since the temperature conditions and / or the pressure conditions can be monitored.

[0223] According to yet another preferred embodiment of the present invention, the sensor in the gas inlet and / or the gas outlet is a pyrometer. This embodiment is advantageous since the pyrometer can withstand high temperatures. Similarly, this embodiment is advantageous since multiple pyrometers can be used to make it a very cost-effective solution.

[0224] According to another preferred embodiment of the present invention, the sensor in the gas inlet and / or the gas outlet is in connection with a control unit. This embodiment is advantageous since the control unit receives the sensor signal or the sensor data. Thus, the control unit can output the conditions in the crucible unit to the operator, in particular as a function of the time stamp, in order to monitor the production or growth process. In addition to or instead of this, the control unit can be given control rules to control the oven device depending on the control rules, time, and / or the sensor output.

[0225] According to another preferred embodiment of the present invention, the receiving space is formed by one or at least one continuous trench or a plurality of recesses. The trench or recess preferably at least partially, preferably substantially, or preferably completely surrounds the crucible unit, particularly the surfaces arranged or provided on the inner surface of its wall and / or the inner side of the bottom section, and preferably the receiving space has an annular shape. Preferably, the heating element covers at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 70%, at least 80%, at least 90%, at least 90%, or at least 95% of the bottom surface of the receiving space and at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 70%, at least 80%, at least 90%, or at least 95% of the surface at least partially surrounded by the receiving space. The area at least partially surrounded by the receiving space preferably belongs to each of the solid wall, the crucible bottom wall, or the crucible bottom section extending vertically over at least a distance V1. Within the receiving space, a distance V2 extends vertically between the bottom surface of the receiving space and the upper surface of the lowermost wall portion of the receiving space, and V2 > V1 (i.e., the distance V2 is larger in the vertical direction). That is, the distance V2 is larger compared to the distance V1. In particular, V2 > 1.1×V1, V2 > 1.2×V1, V2 > 1.5×V1, V2 > 2×V1, V2 = V1, V2 < V1, particularly V2 < 1.1×V1, V2 < 1.2×V1, V2 < 1.5×V1, or V2 < 2×V1.

[0226] Accordingly, preferably, the receiving space surrounds the lower part of the housing and has a surface, in particular, surrounded by the receiving space. The bottom part is preferably a solid material part. Preferably, the solid crucible bottom part is larger than 0.3× the minimum distance between the receiving space and the central axis, or larger than 0.5× the minimum distance between the receiving space and the central axis, or larger than 0.7× the minimum distance between the receiving space and the central axis, or larger than 0.9× the minimum distance between the receiving space and the central axis, or larger than 1.1× the minimum distance between the receiving space and the central axis, or larger than 1.5× the minimum distance between the receiving space and the central axis and has a height (in the vertical direction).

[0227] According to another preferred embodiment of the present invention, the bottom part has an inner surface or a surface surrounded by the receiving space. The inner surface of the bottom part is preferably arranged parallel to the seed holder unit within the crucible volume. The center of the inner surface, the center of the seed holder, and / or the center of the seed wafer 18 held by the seed holder unit are preferably arranged on the same vertical axis. Preferably, the inner surface of the lower part is arranged at a distance determined from the seed holder unit. Preferably, this distance is larger than 0.5× the minimum distance between the receiving space and the central axis, or larger than 0.7× the minimum distance between the receiving space and the central axis, or larger than 0.8× the minimum distance between the receiving space and the central axis, or larger than 1× the minimum distance between the receiving space and the central axis, or larger than 1.2× the minimum distance between the receiving space and the central axis, or larger than 1.5× the minimum distance between the receiving space and the central axis, or larger than 2× the minimum distance between the receiving space and the central axis, or larger than 2.5× the minimum distance between the receiving space and the central axis. This embodiment is advantageous because it has a rotationally symmetric shape that supports the even distribution of the starting material vapor onto the seed wafer 18 or the growing crystal, at least for each section, preferably for most or completely.

[0228] According to yet another preferred embodiment of the present invention, the area surrounded by the receiving space has a size of at least 0.5× the size of the upper surface of the defined seed wafer 18, at least 0.8× the size of the upper surface of the defined seed wafer 18, at least 0.9× the size of the upper surface of the defined seed wafer 18, at least 1× the size of the upper surface of the defined seed wafer 18, at least 1.1× the size of the upper surface of the defined seed wafer 18. In addition to or instead of this, the center of the surface surrounded by the receiving space and the center of the upper surface of the defined seed wafer 18 are preferably arranged on the same vertical axis. In addition to or instead of this, the surface surrounded by the receiving space and the upper surface of the defined seed wafer 18 are preferably arranged parallel to each other. This embodiment is advantageous because heat distribution can be carried out evenly over the surface surrounded by the receiving space.

[0229] According to another preferred embodiment of the present invention, a control unit is provided for controlling the pressure level in the crucible unit and / or in the furnace, for controlling the gas flow into the crucible unit, and / or for controlling the heating unit. Preferably, the heating unit is controlled to generate an isothermal temperature profile parallel to the support unit, perpendicular to the vertical direction, or horizontally. This embodiment is advantageous because it is considered possible to monitor the growth process using predetermined rules and / or sensor data or sensor signals and to control crystal growth by changing one or more operating parameters of one or more of the above-mentioned units.

[0230] According to another preferred embodiment of the present invention, a filter unit is provided. Preferably, the filter unit surrounds the seed crystal holder unit and / or is preferably arranged at least partially above the seed crystal holder unit, in particular at least 60% (by volume) of the filter unit is arranged above the seed crystal holder unit. The filter unit comprises a filter body, the filter body having a filter input surface for introducing a gas containing Si vapor into the filter body and an output surface for discharging the filtered gas, preferably the filter input surface is arranged at a level vertically below the level of the output surface. At least one or exactly one filter element is arranged between the filter input surface and the output surface. The filter element can form the filter input surface and / or the output surface. Preferably, the filter element forms a separation zone for the adsorption and condensation of Si vapor. This design is advantageous because it can trap Si vapor inside the filter element and thus reduce defects caused by Si vapor. Preferably, the separation zone has at least or at most 50% (by volume), at least or at most 80% (by volume), or at least or at most 90% (by volume) of the filter element volume. That is, 1% - 50% (by volume), 10% - 50% (by volume), or 1% - 30% (by volume) of the filter element volume can be a vapor section or a section where the evaporation raw material is in a vapor configuration.

[0231] According to another preferred embodiment of the present invention, the filter element forms a gas flow path from the filter input surface to the output surface. Preferably, the filter element has a height S1, and the gas flow path through the filter element has a length S2, and S2 is at least 10 times longer than S1, in particular, 100 times or 1000 times longer than S1. This design is advantageous because the filter element has sufficient capacity to absorb all Si vapor generated during flow or during crystal growth, especially SiC crystal growth. Therefore, preferably, the filter element forms a highly porous area for incorporating Si sublimation vapor during PVT growth, especially during SiC single crystallization. Preferably, the filter element has a material with an area of at least 100 m2 / g or at least 1000 m2 / g.

[0232] According to another preferred embodiment of the present invention, the filter unit is arranged between a first part of the crucible unit housing and a second part of the crucible unit housing. At least 50% (by volume), in particular at least 80% (by volume) or 90% (by volume) of the first housing part of the crucible unit is arranged vertically below the seed holder unit. A first crucible volume is provided between the first housing part of the crucible unit and the seed holder, and the first crucible volume can be operated such that at least 80%, preferably 90%, or more preferably 100% of the first crucible volume is higher than the condensation temperature Tc of silicon under normal pressure. Furthermore, at most 50% (by volume), at most 20% (by volume), or at most 10% (by volume) of the first part of the crucible unit housing is arranged vertically above the seed holder unit. Instead of this, at least 50% (by volume), in particular at least 80% (by volume) or 90% (by volume) of the first housing part of the crucible unit is arranged vertically above the seed holder unit. Preferably, a second crucible volume is provided between the second housing part of the crucible unit and the seed holder. At least 60%, preferably 80%, or more preferably 90% of the filter elements are lower than the condensation temperature Tc. This embodiment is advantageous because the output material evaporates or is caused to evaporate at a temperature of Tc or higher, or condenses or is caused to condense at a temperature of Tc or lower. Therefore, Si condensate can be captured in the filter element by using the fact that the Si vapor condenses at a temperature lower than a predetermined temperature. Therefore, the filter element is very effective.

[0233] According to another preferred embodiment of the present invention, the filter unit is arranged between a first wall portion of the first housing part and yet another wall portion of the second housing part. Preferably, the filter body forms the filter outer surface. Preferably, the filter outer surface connects the first wall portion of the first housing part and yet another wall portion of the second housing part. Preferably, the filter outer surface forms part of the outer surface of the crucible unit. This embodiment is advantageous because the filter unit can be arranged to increase the volume of the crucible unit without the need for one or two or more additional crucible housing parts.

[0234] According to another preferred embodiment of the present invention, the filter outer surface comprises a filter outer surface covering element. The filter outer surface covering element is preferably a sealing element. The sealing element is preferably a coating. Preferably, the coating is achieved on, or attached to, or forms the filter surface. Preferably, the coating has a material or a combination thereof that reduces the leakage of sublimation vapor, particularly Si vapor, which is generated during the process and enters the furnace volume through the crucible housing from the crucible volume, by at least 50% (mass), at least 80% (mass), at least 90% (mass), more than 99% (mass), or at least 99.9% (mass).

[0235] Preferably, the coating withstands temperatures higher than 2000 °C, in particular at least or at most 3000 °C, or at least at most 3000 °C, or at most 3500 °C, or at least at most 3500 °C, or at most 4000 °C, or at least at most 4000 °C. Preferably, the coating comprises one or more materials selected from the group of materials comprising at least carbon, in particular pyrolytic carbon and vitreous carbon. This embodiment is advantageous since the filter unit can form the outer barrier of the crucible unit. Thus, preferably, the filter unit absorbs or traps Si and preferably prevents Si vapor from leaking. The ash content of the filter element is preferably lower than 5% (by mass) or lower than 1% (by mass). This means that less than 5% or less than 1% of the mass of the filter element is ash.

[0236] According to another preferred embodiment of the present invention, the filter body forms an inner filter surface. The inner filter surface is preferably coaxial with the outer filter surface. The filter body preferably has an annular shape. The outer filter surface preferably has a cylindrical shape and / or the inner filter surface preferably has a cylindrical shape. The outer filter surface and / or the inner filter surface have the longest extension in the vertical or circumferential direction. This embodiment is advantageous because the filter unit can be arranged in a simple manner due to its shape. In addition to or instead of this, the inner filter surface surrounds the space above the seed holder unit. The space surrounded by the seed holder unit can function as a cooling space for cooling the filter element and / or for cooling the seed holder unit. Preferably, a cooling unit comprising at least one cooling tube for guiding a coolant can be provided. This cooling tube can be arranged to at least partially, at least mostly (more than 50% in the circumferential direction), or completely surround the crucible unit. In addition to or instead of this, the cooling tube can be arranged inside the crucible volume, particularly in the space surrounded by the inner filter surface. However, the cooling tube can also extend into the crucible volume, particularly into the space surrounded by the inner filter surface, through the wall of the crucible unit and / or the wall of the filter unit from the outside of the crucible unit. Furthermore, the cooling tube can extend to the outside of the furnace. This embodiment is advantageous because it can advantageously control the temperature inside the crucible unit. Furthermore, it is possible to set a temperature distribution profile with a considerably steeper gradient in the crucible volume compared to a situation without using a cooling unit.

[0237] According to yet another preferred embodiment of the present invention, the inner surface of the filter has yet another filter inner surface covering element. The yet another filter inner surface covering element is preferably a sealing element. The sealing element is preferably a coating, and preferably the coating is achieved on, or attached to, or forms the filter surface. Preferably, the coating has a material or a combination thereof that resists leakage of at least 50% (by mass), at least 80% (by mass), at least 90% (by mass), or more than 99% (by mass), or at least 99.9% (by mass) of the sublimation vapor generated during the process, particularly Si vapor, from the crucible volume through the crucible housing back into the furnace volume.

[0238] Preferably, the coating withstands a temperature higher than 2000 °C, particularly at least or up to 3000 °C, or at least up to 3000 °C, or up to 3500 °C, or at least up to 3500 °C, or up to 4000 °C, or at least up to 4000 °C. Preferably, the coating has one or more materials selected from the group of materials comprising at least carbon, particularly pyrolytic carbon and vitreous carbon. This solution is advantageous because it prevents the leakage of Si vapor into the space surrounded by the inner surface of the filter.

[0239] Preferably, the filter element is composed of activated carbon blocks and / or one or more particularly different graphite foams, including those made of carbonized bread, rigid graphite insulators, and / or flexible graphite insulators.

[0240] According to another preferred embodiment of the present invention, the filter element comprises a filter element member. The filter element preferably comprises filter particles and a binder. Preferably, the filter particles comprise carbon or are composed of a carbon material. Preferably, the binder holds the filter particles in a fixed relative position to each other. Preferably, the filter particles withstand a temperature higher than 2000 °C, in particular at least or at most 3000 °C, or at least at most 3000 °C, or at most 3500 °C, or at least at most 3500 °C, or at most 4000 °C, or at least at most 4000 °C. Preferably, the filter particles withstand a temperature higher than 2000 °C, in particular at least or at most 3000 °C, or at least at most 3000 °C, or at most 3500 °C, or at least at most 3500 °C, or at most 4000 °C, or at least at most 4000 °C. Preferably, the filter particles withstand a temperature higher than 1700 °C, in particular a temperature higher than 2000 °C, in particular at most 2000 °C, or higher than 2000 °C, in particular at least or at most 3000 °C, or at least at most 3000 °C, or at most 3500 °C, or at least at most 3500 °C, or at most 4000 °C, or at least at most 4000 °C. This solution is advantageous because the solid filter element does not have toxic materials. In addition to this, the solid filter element can be manufactured at low cost. The filter unit, in particular the filter element, is preferably a disposable unit or element.

[0241] According to yet another preferred embodiment of the present invention, the binder comprises starch, or the binder comprises starch.

[0242] According to yet another preferred embodiment of the present invention, the furnace system comprises a gas flow unit. Preferably, the gas flow unit has a gas inlet for conducting gas into the crucible unit and a gas outlet for discharging gas from the crucible unit through the furnace to the outside of the furnace. Preferably, the gas inlet is arranged upstream of the filter unit in the gas flow direction, particularly upstream of the receiving space in the gas flow direction, and the gas outlet is arranged downstream of the filter unit in the gas flow direction. Accordingly, preferably, the gas inlet is arranged in the transition zone within the crucible unit. Preferably, the transition zone further includes a seed holder unit and a receiving space. The starting material can be transferred from a solid configuration to a vapor configuration and further from the vapor configuration to the solid target body. The starting material can be deposited in the receiving space, and the solid target body can be held by the seed holder unit. The solid target body is a crystal, particularly a SiC crystal. The gas introduced through the gas inlet preferably mixes and / or reacts with the starting material in the vapor configuration and / or during solidification. Preferably, the gas outlet is arranged in a capture zone, the capture zone further comprises an outlet surface of the filter unit, and the gas composition within the capture zone is preferably free of Si vapor or has no Si vapor. The temperature within the capture zone is preferably lower than the solidification temperature of Si gas or Si vapor. This embodiment is advantageous because the crystal growth process can be manipulated. For example, it is possible to add one or more gases for doping the crystal. In addition to or instead of this, it is possible to modify, particularly accelerate, the vapor transport from the receiving space to the seed wafer 18 or the crystal. Preferably, uniform growth means that the growth rate at all surface portions of the growth region of the crystal is within a defined range, and / or the accumulation of defects and / or doping is uniformly distributed, and the term "uniformly distributed" defines an acceptable range of deviation.

[0243] According to yet another preferred embodiment of the present invention, the outer diameter of the filter unit corresponds to the outer diameter of the receiving space, and / or the inner diameter of the filter unit preferably corresponds to the inner diameter of the receiving space. This embodiment is advantageous because it does not cause any significant complexity in the shape of the housing and thus enables inexpensive manufacturing. The outer diameter of the filter unit is preferably at least or at most 1.05× compared to the outer diameter of the receiving chamber, or preferably at least or at most 1.1× compared to the outer diameter of the receiving space, or preferably at least or at most 1.3× compared to the outer diameter of the receiving space, or preferably at least or at most 1.5× compared to the outer diameter of the receiving space. Alternatively, the outer diameter of the receiving space is preferably at least or at most 1.05× compared to the outer diameter of the filter unit, or preferably at least or at most 1.1× compared to the outer diameter of the filter unit, or preferably at least or at most 1.3× compared to the outer diameter of the filter unit, or preferably at least or at most 1.5× compared to the outer diameter of the filter unit. In addition or alternatively, the inner diameter of the receiving space is preferably at least or at most 1.05× larger compared to the inner diameter of the filter unit, or preferably at least or at most 1.1× larger, or preferably at least or at most 1.3× larger compared to the inner diameter of the filter unit, or preferably at least or at most 1.5× larger compared to the inner diameter of the filter unit. Alternatively, the inner diameter of the filter unit is preferably at least or at most 1.05× larger compared to the inner diameter of the receiving space, preferably at least or at most 1.1× larger compared to the inner diameter of the receiving space, preferably at least or at most 1.3× larger compared to the inner diameter of the receiving space, and preferably at least or at most 1.5× larger compared to the inner diameter of the receiving space.

[0244] According to another preferred embodiment of the present invention, a growth guiding element for guiding the starting material vapor and / or the introduction gas into the space between the seed holder unit and the inner bottom surface of the crucible unit is arranged or provided above the vertical receiving space. This embodiment is advantageous because the growth guiding element preferably performs several functions. On the one hand, the growth guiding element guides the starting material vapor to the seed wafer 18 or the growing crystal. On the other hand, the growth guiding element affects the shape of the crystal by restricting the radial extension of the growing crystal.

[0245] According to another preferred embodiment of the present invention, the growth guiding element comprises a first wall section or a first growth guiding section and a second wall section or a second growth guiding section. Preferably, the first growth guiding section is shaped to match the corresponding wall section of the crucible housing. Preferably, the matching in this situation means that the wall portion of the crucible housing and the growth guiding member are preferably joined by a snug fit and / or a press fit. The second part of the growth guide is preferably shaped to manipulate the shape of the growing crystal. According to another preferred embodiment of the present invention, the first part of the growth guide and the second part of the growth guide are coaxially arranged. The first section of the growth guide is arranged at a location of a first diameter with respect to the central axis, and the second section of the growth guide is arranged at a location of a second diameter with respect to the central axis, and the first diameter is larger compared to the second diameter. The first growth guiding section and the second growth guiding section are interconnected by a third wall section and a third growth guiding section respectively, and the third growth guiding section extends at least partially horizontally. The first growth guiding section and the third growth guiding section form an arcuate section and a fourth growth guiding section respectively, and / or the second growth guiding section and the third growth guiding section are arranged at an angle between 60° and 120°, particularly between 70° and 110°, particularly at an angle of 90°. The fourth growth guiding section can have, for example, a convex shape, a concave shape, or a conical shape. The first wall section, the second section of the growth support, and the third section of the growth support are preferably an integral part of the growth support. Preferably, the growth support is made of graphite. This embodiment is advantageous because the growth guiding element has a simple but effective shape. Therefore, the growth guiding element can be manufactured in a cost-effective manner.

[0246] According to another preferred embodiment of the present invention, the outer diameter of the filter unit is at least or at most 1.05× larger than the first diameter of the growth guiding element, or preferably at least or at most 1.1× larger than the first diameter of the growth guiding element, or preferably at least or at most 1.3× larger than the first diameter of the growth guiding vessel, or preferably at least or at most 1.3× larger than the first diameter of the growth guiding vessel, or preferably at least or at most 1.5× larger than the first diameter of the growth guiding vessel, and / or the second diameter of the growth guiding vessel is preferably at least or at most 1.05× larger compared to the inner diameter of the filter unit, or preferably at least or at most 1.1× larger compared to the inner diameter of the filter unit, or preferably at least or at most 1.3× larger compared to the inner diameter of the filter unit, or preferably at least or at most 1.5× larger compared to the inner diameter of the filter unit.

[0247] The upper vertical end of the second section of the growth guiding vessel and the seed holder unit form a gas flow channel, and the minimum distance between the upper vertical end of the second section of the growth guiding vessel and the seed holder unit is less than 0.3× of the second diameter of the growth guiding vessel, or less than 0.1× of the second diameter of the growth guiding vessel, or less than 0.08× of the second diameter of the growth guiding vessel, or less than 0.05× of the second diameter of the growth guiding vessel, or less than 0.03× of the second diameter of the growth guiding vessel, or less than 0.01× of the second diameter of the growth guiding vessel.

[0248] According to yet another preferred embodiment of the present invention, preferably, the coating is applied to the receiving space within the crucible volume, in particular its surface, and / or to the growth guiding element, the growth guiding plate, or the gas distribution plate. Preferably, the coating has a material or a combination thereof that reduces the transmission rate of Si vapor through the wall portion defining the boundary of the receiving space and / or the wall portion defining the boundary of the growth guiding element to 10-3 m2 / s, preferably 10-11 m2 / s, or more preferably 10-12 m2 / s.

[0249] Preferably, the coating withstands temperatures higher than 2000 °C, in particular at least or maximally 3000 °C, or at least maximally 3000 °C, or maximally 3500 °C, or at least maximally 3500 °C, or maximally 4000 °C, or at least maximally 4000 °C. This embodiment is advantageous because the modified suppression element and / or growth guiding element has at least two material layers, one forming the structure of the suppression element and / or growth guiding element and the other reducing or avoiding the permeability of Si vapor. Most preferably, the coating has one or more materials selected from the group of materials comprising at least carbon, in particular pyrolytic carbon and vitreous carbon. Accordingly, preferably, the receiving space and / or growth conducting element is coated with pyrolytic carbon and / or vitreous carbon. Preferably, the pyrolytic carbon layer has a thickness greater than 10 μm or maximally 10 μm, in particular greater than 20 μm or maximally 20 μm, greater than 50 μm or maximally 50 μm, greater than 100 μm or maximally 100 μm, greater than 200 μm or maximally 200 μm, or greater than 500 μm or maximally 500 μm. Preferably, the vitreous carbon layer has a thickness greater than 10 μm or maximally 10 μm, in particular greater than 20 μm or maximally 20 μm, greater than 50 μm or maximally 50 μm, greater than 100 μm or maximally 100 μm, greater than 200 μm or maximally 200 μm, or greater than 500 μm or maximally 500 μm. Further, according to a preferred embodiment, the coating is produced by chemical vapor deposition, or in particular by printing a precursor material, in particular phenol formaldehyde, thereon and subsequent pyrolysis. This embodiment is advantageous because the coating can be generated in a reliable manner.

[0250] According to another preferred embodiment of the present invention, the heating unit comprises at least one heating element. Preferably, the heating element is arranged below the receiving space vertically and / or below the bottom part of the crucible unit, and the bottom part of the crucible unit is surrounded by the receiving space. This design is advantageous because the receiving space and / or the bottom section surrounded thereby can be heated by the heating element. Preferably, the heating element at least partially overlaps with the receiving space and / or the bottom section surrounded thereby, preferably more than 50%, more than 70%, or up to 90% at most, or completely. This design is advantageous because an even temperature distribution can be set, and in particular an even temperature level can be generated.

[0251] According to yet another preferred embodiment of the present invention, the furnace device comprises a gas flow unit. Preferably, the gas flow unit has a gas inlet for conducting gas into the crucible unit or into the crucible volume, and a gas outlet for drawing gas out of the crucible unit or the crucible volume. Preferably, the gas inlet is arranged closer to the bottom of the crucible unit than the gas outlet. Both the gas inlet and the gas outlet are preferably arranged within the crucible volume. This design is advantageous because it can affect or control the conditions within the crucible volume, the composition of the vapor, and / or the flow (direction and / or velocity) of the liquid within the crucible.

[0252] According to another preferred embodiment of the present invention, the gas outlet comprises gas conveying means, in particular a tube. Preferably, the gas outlet preferably has a sensor, in particular a temperature sensor and / or a pressure sensor, arranged inside the conveying means, in particular the tube, or arranged as part of the conveying means, in particular the tube, or attached to the outer wall of the conveying means, in particular the tube. This embodiment is advantageous because the temperature conditions and / or the pressure conditions can be monitored.

[0253] According to yet another preferred embodiment of the present invention, in addition to or instead of this, the gas inlet comprises gas conducting means, in particular a pipe. Preferably, the gas inlet preferably has a sensor, in particular a temperature sensor and / or a pressure sensor, arranged inside the conduit means, in particular the tube, or as part of the conduit means, in particular the tube, or attached to the outer wall of the conduit means, in particular the tube. This embodiment is advantageous because the temperature conditions and / or pressure conditions can be monitored.

[0254] According to yet another preferred embodiment of the present invention, the sensor in the gas inlet and / or gas outlet is a pyrometer. This embodiment is advantageous because the pyrometer can withstand high temperatures. Similarly, this embodiment is advantageous because multiple pyrometers can be used to make it a very cost-effective solution.

[0255] According to another preferred embodiment of the present invention, the sensor in the gas inlet and / or gas outlet is in a connected state with the control unit. This embodiment is advantageous because the control unit receives the sensor signal or sensor data. Therefore, the control unit can output the conditions in the crucible unit to the operator, in particular as a function of the time stamp, in order to monitor the production or growth process. In addition to or instead of this, the control unit can be given control rules to control the oven device depending on the control rules, time, and / or sensor output.

[0256] According to another preferred embodiment of the present invention, the receiving space is formed by one or at least one continuous trench or a plurality of recesses. The trench or recess preferably at least partially, preferably substantially, or preferably completely surrounds a crucible unit, particularly a surface disposed or provided on the inner surface of its wall and / or the inner side of the bottom section, and preferably, the receiving space has an annular shape. Preferably, the heating element covers at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 70%, at least 80%, at least 90%, at least 90%, or at least 95% of the bottom surface of the receiving space and at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 70%, at least 80%, at least 90%, or at least 95% of the surface at least partially surrounded by the receiving space. The area at least partially surrounded by the receiving space preferably belongs to a solid wall, a crucible bottom wall, or a crucible bottom section that extends vertically over at least a distance V1, and within the receiving space, a distance V2 extends vertically between the bottom surface of the receiving space and the upper surface of the lowermost wall portion of the receiving space, and V2 > V1 (i.e., the distance V2 is greater in the vertical direction). That is, the distance V2 is greater compared to the distance V1, in particular, V2 > 1.1×V1, V2 > 1.2×V1, V2 > 1.5×V1, V2 > 2×V1, V2 = V1, V2 < V1, in particular V2 < 1.1×V1, V2 < 1.2×V1, V2 < 1.5×V1, or V2 < 2×V1.

[0257] Accordingly, preferably, the receiving space surrounds the lower part of the housing and has a surface, in particular, surrounded by the receiving space. The bottom part is preferably a solid material part. Preferably, the solid crucible bottom part is larger than 0.3× the minimum distance between the receiving space and the central axis, or larger than 0.5× the minimum distance between the receiving space and the central axis, or larger than 0.7× the minimum distance between the receiving space and the central axis, or larger than 0.9× the minimum distance between the receiving space and the central axis, or larger than 1.1× the minimum distance between the receiving space and the central axis, or larger than 1.5× the minimum distance between the receiving space and the central axis, and has a height (in the vertical direction).

[0258] According to another preferred embodiment of the present invention, the bottom part has an inner surface or a surface surrounded by the receiving space. The inner surface of the bottom part is preferably arranged parallel to the seed holder unit within the crucible volume. The center of the inner surface, the center of the seed holder, and / or the center of the seed wafer 18 held by the seed holder unit are preferably arranged on the same vertical axis. Preferably, the inner surface of the lower part is arranged at a distance determined from the seed holder unit. Preferably, this distance is larger than 0.5× the minimum distance between the receiving space and the central axis, or larger than 0.7× the minimum distance between the receiving space and the central axis, or larger than 0.8× the minimum distance between the receiving space and the central axis, or larger than 1× the minimum distance between the receiving space and the central axis, or larger than 1.2× the minimum distance between the receiving space and the central axis, or larger than 1.5× the minimum distance between the receiving space and the central axis, or larger than 2× the minimum distance between the receiving space and the central axis, or larger than 2.5× the minimum distance between the receiving space and the central axis. The shape of this embodiment is advantageous because it has a rotationally symmetric shape, at least for each section, preferably mostly or completely, that aids in the even distribution of the starting material vapor onto the seed wafer 18 or the growing crystal.

[0259] According to another preferred embodiment of the present invention, the area surrounded by the receiving space has a size of at least 0.5× the size of the upper surface of the defined seed wafer 18, at least 0.8× the size of the upper surface of the defined seed wafer 18, at least 0.9× the size of the upper surface of the defined seed wafer 18, at least 1× the size of the upper surface of the defined seed wafer 18, or at least 1.1× the size of the upper surface of the defined seed wafer 18. In addition to or instead of this, the center of the surface surrounded by the receiving space and the center of the upper surface of the defined seed wafer 18 are preferably arranged on the same vertical axis. In addition to or instead of this, the surface surrounded by the receiving space and the upper surface of the defined seed wafer 18 are preferably arranged parallel to each other. This embodiment is advantageous because heat distribution can be carried out evenly over the surface surrounded by the receiving space.

[0260] According to another preferred embodiment of the present invention, a control unit is provided to control the pressure level in the crucible unit and / or in the furnace, to control the gas flow into the crucible unit, and / or to control the heating unit. Preferably, the heating unit is controlled to generate an isothermal temperature profile parallel to the support unit, perpendicular to the vertical direction, or horizontally. This embodiment is advantageous because it is considered possible to monitor the growth process using predefined rules and / or sensor data or sensor signals and to control crystal growth by changing one or more operating parameters of one or more of the above-mentioned units.

[0261] According to another preferred embodiment of the present invention, a filter unit is provided. Preferably, the filter unit surrounds the seed holder unit and / or is preferably arranged at least partially above the seed holder unit, in particular at least 60% (by volume) of the filter unit is arranged above the seed holder unit. The filter unit comprises a filter body, the filter body having a filter input surface for introducing a gas containing Si vapor into the filter body and an output surface for discharging the filtered gas, preferably the filter input surface is arranged at a level vertically below the level of the output surface. At least one or exactly one filter element is arranged between the filter input surface and the output surface. The filter element can form the filter input surface and / or the output surface. Preferably, the filter element forms a separation region for the adsorption and condensation of Si vapor. This design is advantageous as it can capture Si vapor inside the filter element and thus reduce defects caused by Si vapor. Preferably, the uptake region has at least or at most 50% (by volume), at least or at most 80% (by volume), or at least or at most 90% (by volume) of the filter element volume. Thus, 1% - 50% (by volume), 10% - 50% (by volume), or 1% - 30% (by volume) of the filter element volume can be a vapor section or a section where the starting material vapor is in a vapor configuration.

[0262] According to another preferred embodiment of the present invention, the filter element forms a gas flow path from the filter input surface to the output surface. Preferably, the filter element has a height S1, the gas flow path through the filter element has a length S2, and S2 is at least 10 times longer than S1, in particular 100 times or 1000 times longer than S1. This design is advantageous because the filter element has sufficient capacity to absorb all Si vapor generated during flow or during crystal growth, especially SiC crystal growth. Thus, preferably, the filter element forms a highly porous area for incorporating Si sublimation vapor during PVT growth, especially during SiC single crystallization. Preferably, the filter element has a material with an area of at least 100 m2 / g or at least 1000 m2 / g.

[0263] According to another preferred embodiment of the present invention, the filter unit is arranged between a first part of the crucible unit housing and a second part of the crucible unit housing. At least 50% (by volume), in particular at least 80% (by volume) or 90% (by volume) of the first housing part of the crucible unit is arranged vertically below the seed holder unit. A first crucible volume is provided between the first housing part of the crucible unit and the seed holder unit, and the first crucible volume can be operated such that at least 80%, preferably 90%, or more preferably 100% of the first crucible volume is higher than the condensation temperature Tc of silicon under normal pressure. Further, at most 50% (by volume), at most 20% (by volume), or at most 10% (by volume) of the first part of the crucible unit housing is arranged vertically above the seed holder unit. Instead of this, at least 50% (by volume), in particular at least 80% (by volume) or 90% (by volume) of the first housing part of the crucible unit is arranged vertically above the seed holder unit. Preferably, a second crucible volume is provided between the second housing part of the crucible unit and the seed holder. At least 60%, preferably 80%, or more preferably 90% of the filter elements are lower than the condensation temperature Tc. This embodiment is advantageous because the starting material evaporates or is caused to evaporate at a temperature of Tc or higher, or condenses or is caused to condense at a temperature of Tc or lower. Therefore, Si condensate can be captured in the filter element by using the fact that the Si vapor condenses at a temperature lower than a predetermined temperature. Therefore, the filter element is very effective.

[0264] According to another preferred embodiment of the present invention, the filter unit is arranged between a first wall portion of the first housing part and yet another wall portion of the second housing part. Preferably, the filter body forms the filter outer surface. Preferably, the filter outer surface connects a first wall portion of the first housing part and yet another wall portion of the second housing part. Preferably, the filter outer surface forms part of the outer surface of the crucible unit. This embodiment is advantageous because the filter unit can be arranged to increase the volume of the crucible unit without the need for one or two or more additional crucible housing parts.

[0265] According to another preferred embodiment of the present invention, the filter outer surface comprises a filter outer surface cover element. The filter outer surface cover element is preferably a sealing element. The sealing element is preferably a coating. Preferably, the coating is achieved on, or attached to, or forms the filter surface. Preferably, the coating has a material or a combination thereof that reduces the leakage of sublimation vapor, particularly Si vapor, which occurs during the process and enters the furnace volume through the crucible housing from the crucible volume, by at least 50% (mass), at least 80% (mass), at least 90% (mass), more than 99% (mass), or at least 99.9% (mass).

[0266] Preferably, the coating withstands temperatures higher than 2000°C, in particular at least or at most 3000°C, or at least at most 3000°C, or at most 3500°C, or at least at most 3500°C, or at most 4000°C, or at least at most 4000°C. Preferably, the coating comprises one or more materials selected from the group of materials comprising at least carbon, in particular pyrolytic carbon and vitreous carbon. This embodiment is advantageous since the filter unit can form the outer barrier of the crucible unit. Thus, preferably, the filter unit absorbs or traps Si and preferably prevents the leakage of Si vapor. The ash content of the filter element is preferably lower than 5% (by mass) or lower than 1% (by mass). This means that less than 5% or less than 1% of the mass of the filter element is ash.

[0267] According to another preferred embodiment of the present invention, the filter body forms an inner filter surface. The inner filter surface is preferably coaxial with the outer filter surface. The filter body preferably has an annular shape. The outer filter surface preferably has a cylindrical shape and / or the inner filter surface preferably has a cylindrical shape. The outer filter surface and / or the inner filter surface have the longest extension in the vertical or circumferential direction. This embodiment is advantageous because the filter unit can be arranged in a simple manner due to its shape. In addition to or instead of this, the inner filter surface surrounds the space above the seed holder unit. The space surrounded by the seed holder unit can function as a cooling space for cooling the filter element and / or for cooling the seed holder unit. Preferably, a cooling unit comprising at least one cooling tube for guiding a coolant can be provided. This cooling tube can be arranged to at least partially, at least mostly (more than 50% in the circumferential direction), or completely surround the crucible unit. In addition to or instead of this, the cooling tube can be arranged in the crucible volume, particularly in the space surrounded by the inner filter surface. However, it is also possible for the cooling tube to extend from the outside of the crucible unit through the wall of the crucible unit and / or the wall of the filter unit into the crucible volume, particularly into the space surrounded by the inner filter surface. Furthermore, it is possible for the cooling tube to extend to the outside of the furnace. This embodiment is advantageous because it can advantageously control the temperature inside the crucible unit. Furthermore, it is possible to set a temperature distribution profile with a considerably steep gradient in the crucible volume compared to a situation without using a cooling unit.

[0268] According to yet another preferred embodiment of the present invention, the inner surface of the filter has yet another inner surface cover element of the filter. The yet another inner surface cover element of the filter is preferably a sealing element. The sealing element is preferably a coating, and preferably the coating is achieved on the filter surface, or attached to the filter surface, or forms the filter surface. Preferably, the coating has a material or a combination thereof that resists leakage of sublimation vapor generated during the process, particularly Si vapor, from the crucible volume through the crucible housing back into the furnace volume, especially at least 50% (by mass), at least 80% (by mass), at least 90% (by mass), or more than 99% (by mass), or at least 99.9% (by mass).

[0269] Preferably, the coating withstands a temperature higher than 2000 °C, particularly at least or up to 3000 °C, or at least up to 3000 °C, or up to 3500 °C, or at least up to 3500 °C, or up to 4000 °C, or at least up to 4000 °C. Preferably, the coating comprises one or more materials selected from the group of materials comprising at least carbon, particularly pyrolytic carbon and vitreous carbon. This solution is advantageous because it prevents the leakage of Si vapor into the space surrounded by the inner surface of the filter.

[0270] Preferably, the filter element comprises an activated carbon block and / or one or more particularly different graphite foams, including those made of carbonized pan, rigid graphite insulator, and / or flexible graphite insulator.

[0271] According to another preferred embodiment of the present invention, the filter element comprises a filter element member. The filter element preferably comprises filter particles and a binder. Preferably, the filter particles comprise carbon or are composed of a carbon material. Preferably, the binder holds the filter particles in a fixed relative position to each other. Preferably, the filter particles withstand a temperature higher than 2000 °C, in particular at least or at most 3000 °C, or at least at most 3000 °C, or at most 3500 °C, or at least at most 3500 °C, or at most 4000 °C, or at least at most 4000 °C. Preferably, the filter particles withstand a temperature higher than 2000 °C, in particular at least or at most 3000 °C, or at least at most 3000 °C, or at most 3500 °C, or at least at most 4000 °C. Preferably, the filter particles withstand a temperature higher than 1700 °C, in particular a temperature higher than 2000 °C, in particular at most 2000 °C, or higher than 2000 °C, in particular at least or at most 3000 °C, or at least at most 3000 °C, or at most 3500 °C, or at least at most 3500 °C, or at most 4000 °C, or at least at most 4000 °C. This solution is advantageous because the solid filter element does not have toxic materials. Furthermore, the solid filter element can be manufactured at low cost. The filter unit, in particular the filter element, is preferably a disposable unit or element.

[0272] According to yet another preferred embodiment of the present invention, the binder comprises starch or the binder comprises starch.

[0273] According to yet another preferred embodiment of the present invention, the furnace system comprises a gas flow unit. Preferably, the gas flow unit has a gas inlet for conducting gas into the crucible unit and a gas outlet for discharging gas from the crucible unit through the furnace to the outside of the furnace. Preferably, the gas inlet is arranged upstream of the filter unit in the gas flow direction, particularly upstream of the receiving space in the gas flow direction, and the gas outlet is arranged downstream of the filter unit in the gas flow direction. Accordingly, preferably, the gas inlet is arranged in the transition zone within the crucible unit. Preferably, the transition zone further includes a seed holder unit and a receiving space. The starting material can transition from a solid configuration to a vapor configuration and further from the vapor configuration to a solid target body. The starting material can be deposited in the receiving space, and the solid target body can be held by the seed holder unit. The solid target body is a crystal, particularly a SiC crystal. The gas introduced through the gas inlet preferably mixes and / or reacts with the starting material in the vapor configuration and / or during solidification. Preferably, the gas outlet is positioned within a capture zone and further comprises an outflow surface of the filter unit, and the gas composition within the capture zone is preferably free of Si vapor or has no Si vapor. The temperature within the capture zone is preferably lower than the solidification temperature of Si gas or Si vapor. This embodiment is advantageous because the crystal growth process can be manipulated. For example, it is possible to add one or more gases for doping the crystal. In addition to or instead of this, it is possible to modify, particularly accelerate, the vapor transport from the receiving space to the seed wafer 18 or the crystal. In addition to or instead of this, the gas can be supplied at a defined temperature or temperature range.

[0274] An inert gas, particularly argon, or a gas mixture, particularly argon and nitrogen, can be introduced through the gas inlet into the crucible unit, into the crucible volume, or into the conversion zone, or these gases are introduced.

[0275] According to another preferred embodiment of the present invention, the size of the crucible housing is configurable or changeable. The crucible housing surrounds a first volume VI in the crystal growth configuration and surrounds a second volume VII in the coating regeneration configuration. The crystal growth configuration represents a configuration or setting that exists during the growth of the crystal or during the solidification of the starting material vapor at the growth front of the crystal growing on or above the seed wafer 18. The regeneration configuration represents a setting that exists when the seed holder unit 18 is removed and crystal growth is impossible due to its absence. In the regeneration configuration, preferably, the filter unit is not part of the crucible unit, and the lid disposed above the filter unit in the crystal growth configuration preferably contacts the side wall portion of the crucible housing that contacts the lower end of the filter unit during the crystal growth configuration. The volume VI is preferably larger than the volume VII, and the volume VI is at least 10%, at least or at most 20%, at least or at most 30%, at least or at most 40%, at least or at most 50%, at least or at most 60%, at least or at most 70%, at least or at most 80%, at least or at most 100%, at least or at most 100%, at least or at most 120%, at least or at most 150%, at least or at most 200%, or at least or at most 250% larger than the volume VII. This embodiment is advantageous because the crucible unit can be readjusted after use, particularly after one or several processes, particularly at most or at least 3 times, at most or at least 5 times, or at most or at least 10 times. Therefore, the overall service life of the crucible unit is very long. Since the heating unit can also be used multiple times, these provide a very cost-effective furnace device.

[0276] Preferably, the housing has at least one further wall element in the crystal growth configuration compared to the layer regeneration configuration. The at least one further wall element is preferably a certain filter unit or the filter unit described above. In the layer regeneration configuration, the filter unit is removed. The lower housing wall sub-member of the housing in contact with the filter unit in the crystal growth configuration and the upper housing wall sub-member of the housing in contact with the filter unit in the crystal growth configuration are in contact with each other in the coating regeneration configuration. In the coating regeneration configuration, preferably, at least one seal is arranged between the lower housing wall sub-member and the upper housing wall sub-member. In the crystal growth configuration, preferably, at least one seal is arranged between the filter unit and the upper housing wall element, and preferably, at least one seal is arranged between the filter unit and the lower housing wall element. This embodiment is advantageous because gas or vapor leakage is prevented in any configuration.

[0277] According to another preferred embodiment of the present invention, the crucible unit comprises one or at least one receiving space gas guiding element in the coating regeneration configuration. The receiving space gas guiding element extends into the receiving space to guide gas into the receiving space. This embodiment is advantageous because the gas introduced during the coating regeneration configuration comes into reliable contact with the surface of the receiving space.

[0278] According to another preferred embodiment of the present invention, the gas inlet is arranged in a conversion zone within the crucible unit. The conversion zone preferably comprises a seed holder unit and / or a receiving space. This embodiment is advantageous because it can modify the flow of starting material vapor and / or liquid composition flowing upward from the receiving space to the seed wafer 18 and / or the growing crystal.

[0279] Preferably, the receiving space gas guiding element is at least partially placed on each gas distribution element, and preferably, the gas distribution element holds the receiving space gas guiding element, in particular by a precise connection. This embodiment is advantageous because the attachment can be carried out quickly and easily.

[0280] The receiving space gas guiding element preferably has an annular or circular shape. This embodiment is advantageous because the amount of starting material vapor more reliably matches the amount of material vapor that solidifies on the seed wafer 18 of the crystal compared to another shape such as a rectangular receiving space shape. The receiving space gas guiding member is preferably made of carbon or made of carbon and / or graphite.

[0281] According to yet another preferred embodiment of the present invention, the first section of the growth conductor and the third section of the growth conductor particularly form the fourth section of the growth conductor on the lower side, and / or the second section of the growth conductor and the third section of the growth conductor are arranged at an angle between 60° and 120°, particularly between 70° and 110°, and particularly at an angle of 90°.

[0282] Preferably, a growth plate gas guiding member for guiding gas is provided on the upper surface of the third section of the gas guiding member. The growth plate gas guiding member preferably has an annular or circular shape. The growth plate gas guiding member is preferably arranged on the upper side or the upper wall portion of the housing. The growth plate gas guiding element is preferably made of carbon or made of carbon and / or graphite.

[0283] That is, a method and a reactor or furnace device or apparatus for the PVT growth of a SiC single crystal preferably provide a furnace volume having a function of receiving a crucible unit and a heater, having a lid, and / or having a seed holder incorporated in or attached to the lid, and / or having a SiC single crystal seed attached to the seed holder, and / or having an axial heater disposed below the crucible unit to insulate and / or provide inside the vacuum chamber so as to generate a radially flat isotherm in the growing crystal, and / or disposing the source material in the crucible unit so that no source material exists between the axial heat source and the seed, and / or generating a vacuum in the crucible unit, heating and sublimating each source material of the SiC solid material (generated from the method according to the present invention), and growing a crystal, particularly a SiC single crystal.

[0284] The above-mentioned object is also solved, in particular, preferably by a SiC production reactor for the production of a PVT source material which is preferably UPSiC. The SiC production reactor comprises at least a processing chamber and a gas inlet unit for feeding one or more feed media into the reaction space of the processing chamber, the gas inlet unit being coupled to at least one feed media source, the Si and C feed media sources providing at least Si and C, in particular SiCl3(CH3), and the carrier gas feed media source providing a carrier gas, in particular H2. Alternatively, the gas inlet unit is coupled to at least two feed media sources, the Si feed media source providing at least Si, in particular a first feed media, i.e., a Si feed media, in particular of the general formula SiH 4-y X y(Provide Si gas according to X = [Cl, F, Br, J] and y = [0...4], the C feed medium source provides at least C, especially the second feed medium, that is, the C feed medium, especially natural gas, methane, ethane, propane, butane, and / or acetylene, and further the carrier gas medium source is coupled to the gas inlet unit to provide a third feed medium, that is, the carrier gas, especially H2. The SiC production reactor includes one or more, especially 3, 4, 6, 8, 16, 32, or more than 64, up to 128, or up to 256 SiC growth substrates arranged inside the processing chamber for depositing SiC, each SiC growth substrate includes a first power connection part and a second power connection part, the first power connection part is the first metal electrode, the second power connection part is the second metal electrode, the first metal electrode and the second metal electrode are preferably blocked from the reaction space, and in order to heat the outer surface of each SiC growth substrate or the surface of the deposited SiC to a temperature between 1300 °C and 1800 °C, especially using resistive heating, preferably internal resistive heating, the SiC growth substrate is coupled between at least one first metal electrode and at least one second metal electrode. Preferably, the SiC production reactor further includes a gas outlet unit for outputting the vent gas and a vent gas recirculation unit, the vent gas recirculation unit is connected to the gas outlet unit and includes at least one separation unit for separating the vent gas into a first fluid and a second fluid, the first fluid is a liquid, the second fluid is a gas, the first storage element and / or conduction element for storing or conducting the first fluid is part of or coupled to the separation unit, and the second storage element and / or conduction element for storing or conducting the second fluid is part of or coupled to the separation unit.)

[0285] This solution can reuse the vent gas, so it is advantageous because the recycled amounts of Si, C, or at least one C-containing molecule, and H2 can be reused for the production of SiC materials, especially PVT source materials. Therefore, based on the initial source gas amount, a considerably larger amount of SiC can be produced compared to a SiC production reactor that does not recirculate the vent gas.)

[0286] Preferably, the vent gas recirculation unit comprises yet another separation unit for separating the first fluid into at least two parts, namely a chlorosilanes mixture and a mixture of HCl, H2 and at least one C-containing molecule. Alternatively, yet another separation unit separates the first fluid into at least three parts, namely a chlorosilanes mixture, HCl, H2 and a mixture of at least one C-containing molecule, and the first storage element and / or conducting element connects the separation unit to yet another separation unit. Preferably, yet another separation unit is coupled to a storage element and / or conducting element for the chlorosilanes mixture, a storage element and / or conducting element for HCl, and a storage element and / or conducting element for H2 and C. Preferably, the storage element and / or conducting element for the chlorosilanes mixture forms a section of the chlorosilanes mass flux path for conducting the chlorosilanes mixture into the processing chamber. Preferably, a Si mass flux measurement unit for measuring the amount of Si in the chlorosilanes mixture is provided as yet another Si feed medium source, preferably as part of the mass flux path before the processing chamber, particularly before the mixing device, which preferably provides yet another Si feed medium. Preferably, the storage element and / or conducting element for the chlorosilanes mixture forms a section of the chlorosilanes mass flux path for conducting the chlorosilanes mixture into yet another processing chamber of yet another SiC production reactor. Preferably, the storage element and / or conducting element for H2 and C forms a section of the H2 and C mass flux path for conducting H2 and at least one C-containing molecule into the processing chamber. Preferably, a C mass flux measurement unit for measuring the amount of C in the mixture of H2 and at least one C-containing molecule is provided as yet another C feed medium source, preferably as part of the H2 and C mass flux path before the processing chamber, particularly before the mixing device, which preferably provides yet another C feed medium. Preferably, the storage element and / or conducting element for H2 and C forms a section of the H2 and C mass flux path for conducting H2 and at least one C-containing molecule into yet another processing chamber of yet another SiC production reactor.Preferably, the second storage element and / or conduction element forms a section of the mass flux path of H2 and C for conducting a second fluid comprising H2 and at least one C-containing molecule into the processing chamber, and the second storage element and / or conduction element and the storage element and / or conduction element of H2 and C are preferably fluidly coupled. Preferably, the second storage element and / or conduction element forms yet another section of the mass flux path of H2 and C for conducting a second fluid comprising H2 and at least one C-containing molecule into the processing chamber. Preferably, yet another C mass flux measurement unit for measuring the amount of C in the second fluid is provided as part of yet another mass flux path of H2 and C in front of the processing chamber, in particular in front of the mixing device. Alternatively, the second storage element and / or conduction element is coupled to a flare unit for combusting the second fluid. Preferably, the separation unit is configured to operate at a pressure higher than 5 bar and a temperature lower than -30°C. Preferably, a first compressor for compressing the vent gas to a pressure higher than 5 bar is provided as part of the separation unit or in the gas flow path between the gas outlet unit and the separation unit. Preferably, yet another separation unit is configured to operate at a pressure higher than 5 bar and a temperature lower than -30°C and / or higher than 100°C. Preferably, yet another compressor for compressing the first fluid to a pressure higher than 5 bar is provided as part of yet another separation unit or in the gas flow path between the separation unit and yet another separation unit. Yet another separation unit preferably comprises a cryogenic distillation unit, which is preferably configured to operate at a temperature between -180°C and -40°C. A control unit for controlling the fluid flow of one or more feed media is preferably part of the SiC production reactor, the plurality of feed media comprising a first medium, a second medium, and a third medium, and yet another Si feed media and / or yet another C feed media is supplied into the processing chamber through the gas inlet unit.Preferably, yet another Si feed medium is composed of a chlorosilanes mixture of at least 95% (by mass), at least 98% (by mass), at least 99% (by mass), at least 99.9% (by mass), at least 99.99% (by mass), or at least 99.999% (by mass), and even more preferably, at least 99.99999% (by mass). Preferably, yet another C feed medium comprises at least one C-containing molecule, HCl, H2, and a chlorosilanes mixture, and comprises at least 3% (by mass), preferably at least 5% (by mass), or very preferably at least 10% (by mass) of C or at least one C-containing molecule, and comprises HCl of up to 10% (by mass), preferably between 0.001% (by mass) and 10% (by mass), very preferably between 1% (by mass) and 5% (by mass), and comprises H2 of more than 5% (by mass), preferably more than 10% (by mass), or very preferably more than 25% (by mass), and further comprises a chlorosilanes mixture of more than 0.01% (by mass), preferably more than 1% (by mass), very preferably between 0.001% (by mass) and 10% (by mass).

[0287] Preferably, a heating unit is arranged between yet another separation unit and a gas inlet unit in the flow direction of the fluid to heat the chlorosilanes mixture to transfer it from a liquid form to a gaseous form.

[0288] The processing chamber is at least surrounded by a base plate, a side wall section, and an upper wall section. Preferably, the base plate comprises at least one cooling element, particularly a base cooling element, to prevent it from being heated above a defined temperature, and / or preferably the side wall section comprises at least one cooling element, particularly a baffle cooling element, to prevent it from being heated above a defined temperature, and / or preferably the upper wall section comprises at least one cooling element, particularly a baffle cooling element, to prevent it from being heated above a defined temperature. The cooling element is preferably an active cooling element. Preferably, the base plate, the side wall section, and / or the upper wall section comprise a cooling fluid guiding unit for guiding the cooling fluid, and the cooling fluid guiding unit is configured to limit the heating of the base plate, the side wall section, and / or the upper wall section to a temperature lower than 1000°C. Preferably, a base plate sensor unit, a side wall section sensor unit, and / or an upper wall section sensor unit are provided for detecting the temperature of the base plate, the side wall section, and / or the upper wall section and outputting a temperature signal or temperature data, and / or a cooling fluid temperature sensor is provided for detecting the temperature of the cooling fluid. Further, preferably, a fluid forwarding unit is provided for forwarding the cooling fluid through the fluid guiding unit. Preferably, the fluid forwarding unit is configured to operate depending on the temperature signal or temperature data provided by the base plate sensor unit, the side wall section sensor unit, and / or the upper wall section sensor unit and / or the cooling fluid temperature sensor. Preferably, the cooling fluid is oil or water, and preferably the water comprises at least one additive, particularly a rust inhibitor and / or an antifouling agent (biocide). The cooling element can be, in addition to or instead of this, a passive cooling element. Preferably, the cooling element is at least partially formed by the polished steel surface of the base plate, the side wall section, and / or the upper wall section. The cooling element is preferably a coating, and the coating is formed on the polished steel surface and is configured to reflect heat.Preferably, the coating is a metal coating or comprises a coating of metal, in particular silver, gold, chromium, or an alloy, in particular a CuNi alloy. The emissivity of the polished steel surface and / or the coating is preferably less than εe 0.3, in particular less than 0.1 or less than 0.03. Preferably, the base plate comprises at least one active cooling element and one passive cooling element to prevent it from being heated above a defined temperature, and / or preferably the side wall section comprises at least one active cooling element and one passive cooling element to prevent it from being heated above a defined temperature, and / or preferably the upper wall section comprises at least one active cooling element and one passive cooling element to prevent it from being heated above a defined temperature. The side wall section and the upper wall section are preferably formed by a bell jar, and preferably the bell jar is movable relative to the base plate. Preferably, more than 50% (by mass) of the side wall section, more than 50% (by mass) of the upper wall section, and / or more than 50% (by mass) of the base plate is formed of metal, in particular steel.

[0289] Preferably, the SiC growth substrate has an average perimeter of at least 5 cm, preferably at least 7 cm, and very preferably at least 10 cm around a cross-sectional area orthogonal to its length direction, or a plurality of SiC growth substrates each have an average perimeter of at least 5 cm, preferably at least 7 cm, and very preferably at least 10 cm per SiC growth substrate around a cross-sectional area orthogonal to the length direction of each SiC growth substrate. This solution is advantageous because the volume deposition rate is significantly higher compared to small SiC growth substrates, and thus it is possible to deposit the same amount of SiC material in a shorter time. This solution helps to shorten the process time and thus increase the efficiency of the SiC production reactor. Preferably, the SiC growth substrate comprises or consists of SiC or C, particularly graphite, or a plurality of SiC growth substrates comprise or consist of SiC or C, particularly graphite. The shape of the cross-sectional area orthogonal to the length direction of the SiC growth substrate is different from a circular shape, at least for each section, preferably along more than 50% of the length of the SiC growth substrate, and very preferably along more than 90% of the length of the SiC growth substrate. The ratio U / A between the cross-sectional area A and the perimeter U around the cross-sectional area is preferably higher than 1.2 1 / cm, preferably higher than 1.5 1 / cm, very preferably higher than 2 1 / cm, and most preferably higher than 2.5 1 / cm. Preferably, the SiC growth substrate is formed by at least one carbon ribbon, particularly a graphite ribbon, and at least one carbon ribbon comprises a first ribbon end and a second ribbon end, the first ribbon end being coupled to a first metal electrode and the second ribbon end being coupled to a second metal electrode. Alternatively, each of the plurality of SiC growth substrates is formed by at least one carbon ribbon, particularly a graphite ribbon, and at least one carbon ribbon per SiC growth substrate comprises a first ribbon end and a second ribbon end, the first ribbon end being coupled to the first metal electrode of each SiC growth substrate and the second ribbon end being coupled to the second metal electrode of each SiC growth substrate. The carbon ribbon, particularly the graphite ribbon, preferably comprises a curing agent.Preferably, the SiC growth substrate is formed by a plurality of rods, each rod having a first rod end and a second rod end, all the first rod ends being coupled to the same first metal electrode, and all the second rod ends being coupled to the same second metal electrode. Alternatively, each of the plurality of SiC growth substrates is formed by a plurality of rods, each rod having a first rod end and a second rod end, all the first rod ends being coupled to the same first metal electrode of the respective SiC growth substrate, and all the second rod ends being coupled to the same second metal electrode of the respective SiC growth substrate. Preferably, the rods of the SiC growth substrate are in contact with each other or are spaced apart from each other. The SiC growth substrate preferably comprises 3 or more rods. Alternatively, each of the plurality of SiC growth substrates comprises 3 or more rods. Preferably, the SiC growth substrate is formed by at least one metal rod, the metal rod having a first metal rod end and a second metal rod end, the first metal rod end being coupled to the first metal electrode, and the second metal rod end being coupled to the second metal electrode. Alternatively, each of the plurality of SiC growth substrates is formed by at least one metal rod, each metal rod having a first metal rod end and a second metal rod end, the first metal rod end being coupled to the first metal electrode of the respective SiC growth substrate, and the second metal rod end being coupled to the second metal electrode of the respective SiC growth substrate. The metal rod preferably comprises a coating, the coating preferably comprising SiC and / or preferably having a thickness greater than 2 μm, preferably greater than 100 μm, very preferably greater than 500 μm, or a thickness between 2 μm and 5 mm, particularly between 100 μm and 1 mm, or less than 500 μm.

[0290] The object mentioned above is also solved by an SiC production facility. This SiC production facility comprises at least a plurality of SiC production reactors, in particular SiC production reactors according to the invention, each SiC production reactor comprising at least a processing chamber, a gas inlet unit for feeding one or more feed media into the processing chamber, an SiC growth substrate arranged inside the processing chamber, a first power connection part and a second power connection part to which the SiC growth substrate is connected therebetween for heating the SiC growth substrate by means of resistive heating, preferably using internal resistive heating, and a gas outlet unit for outputting a ventilation gas.

[0291] The SiC production facility also preferably comprises a ventilation gas recirculation unit, the ventilation gas recirculation unit being fluidly connected to the gas outlet of the SiC production reactor and comprising a separation unit for separating the ventilation gas into a first liquid-phase fluid and a second gas-phase fluid.

[0292] The object mentioned above is also solved, in particular, by a method for producing a PVT source material for the production of a PVT source material composed of polymorphic 3C SiC in particular, using a SiC production reactor according to the invention. The method for producing a PVT source material comprises at least the following steps, namely, providing a source medium inside a processing chamber, wherein a gas outlet unit for outputting a ventilation gas from the processing chamber and a ventilation gas recirculation unit are provided, the ventilation gas recirculation unit is connected to the gas outlet unit, and at least one separation unit for separating the ventilation gas into a first fluid and a second fluid is provided. Further, the first fluid is separated into at least two parts, namely, a mixture of chlorosilanes and a mixture of HCl, H2 and at least one C-containing molecule, or alternatively, in place of this, into at least three parts, namely, a mixture of chlorosilanes, HCl, H2 and a mixture of at least one C-containing molecule, by means of a further separation unit. The first storage element and / or conduction element is connected to the separation unit by means of a further separation unit, and the further separation unit is combined with a storage element and / or conduction element for the chlorosilanes mixture, preferably a storage element and / or conduction element for HCl, and preferably a storage element and / or conduction element for H2 and C. The storage element and / or conduction element for the chlorosilanes mixture forms a section of a chlorosilanes mixture mass flux path for conducting the chlorosilanes mixture inside the processing chamber in the above-mentioned providing step, feeding a chlorosilanes mixture through a chlorosilanes mixture mass flux path into the inside of the processing chamber to provide at least one part of the source medium; At least one SiC growth substrate disposed in the processing chamber, preferably a plurality of SiC growth substrates, each SiC growth substrate comprising a first power connection portion and a second power connection portion, the first power connection portion being a first metal electrode and the second power connection portion being a second metal electrode, the first metal electrode and the second metal electrode preferably electrically activating the plurality of SiC growth substrates shielded from the reaction space and heating it to a temperature in the range between 1300 °C and 2000 °C, removing Si and C from the source medium, and setting a deposition rate of more than 200 μm / h in particular to deposit the removed Si and C as SiC, in particular polycrystalline SiC, on the SiC growth substrate. Comprising.

[0293] The step of measuring the Si mass flux of the chlorosilane mixture is a further preferred step, and the Si mass flux measurement is carried out by an Si mass flux measurement unit provided as part of the chlorosilane mixture mass flux path before the processing chamber, particularly before the mixing device. The step of controlling the supply of the chlorosilane mixture to the mixing device depending on the output of the Si mass flux measurement unit is another preferred step of the method. The step of conducting a second fluid comprising H2 and C inside the processing chamber is another preferred step, and the second fluid is flowed into the inside of the processing chamber through a second storage element and / or a conducting element forming a section of the mass flux paths of H2 and C. The step of measuring the C mass flux is another preferred step, and the C mass flux measurement is carried out by a C mass flux measurement unit provided as part of the mass flux paths of H2 and C before the processing chamber, particularly before the mixing device. The step of controlling the step of supplying the second fluid depending on the output of the C mass flux measurement unit is another preferred step of the method. The step of measuring the Si mass flux of the chlorosilane mixture is another preferred step, and the Si mass flux measurement is carried out by an Si mass flux measurement unit provided as part of the chlorosilane mixture mass flux path before the processing chamber, particularly before the mixing device. The step of conducting a second fluid comprising H2 and C inside the processing chamber is another preferred step, and the second fluid is flowed into the inside of the processing chamber through a second storage element and / or a conducting element forming a section of the mass flux paths of H2 and C. The step of measuring the C mass flux is another preferred step, and the C mass flux measurement is carried out by a C mass flux measurement unit provided as part of the mass flux paths of H2 and C before the processing chamber, particularly before the mixing device. The step of controlling the supply of the chlorosilane mixture to the mixing device depending on the output of the Si mass flux measurement unit is another preferred step, and further, the step of controlling the supply of the second fluid depending on the output of the C mass flux measurement unit is another preferred step. Preferably, the processing chamber is at least surrounded by a base plate, a side wall section, and an upper wall section.Preferably, more than 50% (by mass) of the side wall section, more than 50% (by mass) of the upper wall section, and more than 50% (by mass) of the base plate are formed of metal, particularly steel. Preferably, the base plate comprises at least one cooling element for preventing it from being heated above a defined temperature, and / or the side wall section comprises at least one cooling element for preventing it from being heated above a defined temperature, and / or the upper wall section comprises at least one cooling element for preventing it from being heated above a defined temperature. Preferably, a base plate sensor unit, a side wall section sensor unit, and / or an upper wall section sensor unit for detecting the temperature of the base plate, side wall section, and / or upper wall section and outputting a temperature signal or temperature data is provided, and / or a cooling fluid temperature sensor for detecting the temperature of the cooling fluid is provided, and further preferably, a fluid feeding unit for feeding the cooling fluid forward through a fluid guiding unit is provided. Preferably, the fluid feeding unit is configured to operate depending on the temperature signal or temperature data provided by the base plate sensor unit, the side wall section sensor unit, and / or the upper wall section sensor unit, and / or the cooling fluid temperature sensor. Preferably, the step of providing a source medium inside the processing chamber further includes introducing at least a first feed medium, particularly a first source gas, having a purity of at least 99.9999% (weight ppm) excluding substances B, Al, P, Ti, V, Fe, Ni and comprising Si into the inside of the processing chamber, introducing at least a second feed medium, particularly a second source gas, having a purity of at least 99.9999% excluding substances B, Al, P, Ti, V, Fe, Ni and comprising C, particularly natural gas, methane, ethane, propane, butane, and / or acetylene into the inside of the processing chamber, and introducing a carrier gas having a purity of at least 99.9999% (weight ppm) excluding substances B, Al, P, Ti, V, Fe, Ni.Instead, the step of providing the source medium inside the processing chamber includes introducing into the inside of the processing chamber a single feed medium, in particular a source gas, having a purity of at least 99.9999% (weight ppm) excluding substances B, Al, P, Ti, V, Fe, Ni and comprising Si and C, in particular SiCl3(CH3), and introducing a carrier gas having a purity of at least 99.9999% (weight ppm) excluding substances B, Al, P, Ti, V, Fe, Ni.

[0294] A mixture of a first source gas providing Si and a second source gas providing C is introduced into the inside of the processing chamber in a defined amount that is between 0.32 g per hour per cm2 of the SiC growth surface and 10 g per hour per cm2 of the SiC growth surface, whereby a step of setting a pressure higher than 1 bar inside the processing chamber is another preferred step. The Si- and C-containing source gas is introduced into the inside of the processing chamber in a defined amount that is the amount (g / (h cm 2 )) of one or more Si- and C-containing source gases between 0.32 g per hour per cm2 of the SiC growth surface and 10 g per hour per cm2 of the SiC growth surface, whereby a step of setting a pressure higher than 1 bar inside the processing chamber is an alternative step. 2 Preferably, the SiC growth substrate has an average perimeter of at least 5 cm around a cross-sectional area orthogonal to its length direction, or a plurality of SiC growth substrates each have an average perimeter of at least 5 cm around a cross-sectional area orthogonal to the length direction of each respective SiC growth substrate. 2

[0295]

[0296] ​​Preferably, the SiC deposited on the SiC growth substrate has an impurity of substance N lower than 10 ppm (by weight) and one, preferably a plurality, very preferably most, or most preferably all of the impurities of substances B, Al, P, Ti, V, Fe, Ni lower than 1000 ppb (by weight), particularly lower than 500 ppb (by weight), or very preferably, an impurity of substance N lower than 2 ppm (by weight) and each of the impurities of substances B, Al, P, Ti, V, Fe, Ni lower than 100 ppb (by weight), or very preferably an impurity of substance Ti lower than 10 ppb (by weight). Alternatively, the SiC deposited on the SiC growth substrate has an impurity of substance N lower than 10 ppm (by weight) and the total impurities of all of metals Ti, V, Fe, Ni lower than 1000 ppb (by weight), particularly lower than 500 ppb (by weight).

[0297] The method preferably further comprises a step of deaggregating the SiC solid into SiC particles, and the SiC particles are deaggregated to an average length longer than 100 μm.

[0298] The object mentioned above is characterized by a mass heavier than 1 kg, a thickness of at least 1 cm, and a length larger than 50 cm, and is also solved by a PVT source material that forms a SiC solid having an impurity of substance N lower than 10 ppm (by weight) and each of the impurities of substances B, Al, P, Ti, V, Fe, Ni lower than 1000 ppb (by weight), particularly lower than 500 ppb (by weight).

[0299] This solution is beneficial because a large amount of SiC source material solid has significant advantages as a PVT source material.

[0300] Preferably, the SiC solid has an impurity of substance N lower than 2 ppm (by weight) and an impurity of each of substances B, Al, P, Ti, V, Fe, Ni lower than 100 ppb (by weight), and very preferably an impurity of substance Ti lower than 10 ppb (by weight). In addition to or instead of this, the SiC solid has an impurity of substance N lower than 10 ppm (by weight) and a total impurity of all of metals Ti, V, Fe, Ni lower than 1000 ppb (by weight), particularly lower than 500 ppb (by weight).

[0301] Preferably, the SiC solid forms an interface at a distance from the central axis of the SiC solid, the SiC solid forms an outer surface, the outer surface and the interface are formed at a distance from each other, this distance extends perpendicular to the central axis, and the average distance between the outer surface and the interface is larger compared to the average distance between the interface and the central axis. The average distance between the outer surface and the interface is calculated by the following method: (shortest distance (radial direction) + longest distance (radial direction)) / 2. Preferably, the average distance between the outer surface and the interface is at least twice as large compared to the average distance between the interface and the central axis. Preferably, the average distance between the outer surface and the interface is at least five times as large compared to the average distance between the interface and the central axis. Preferably, the interface has an average circumference of at least 5 cm, preferably at least 7 cm, and very preferably at least 10 cm around the cross-section perpendicular to the central axis.

[0302] Preferably, the SiC solid has an excess C lower than 30% (by mass) compared to the ideal stoichiometric ratio of Si and C, preferably an excess C lower than 20% (by mass), very preferably an excess C lower than 10% (by mass), or most preferably an excess C lower than 5% (by mass), and / or preferably an excess Si lower than 30% (by mass) compared to the ideal stoichiometric ratio of Si and C, preferably an excess Si lower than 20% (by mass), very preferably an excess Si lower than 10% (by mass), or most preferably an excess Si lower than 5% (by mass).

[0303] Preferably, the PVT source material is polytype 3C SiC and / or polycrystalline SiC.

[0304] Preferably, the shape of the cross-section orthogonal to the central axis is different from a circular shape, at least for each section, preferably along more than 50% of the extension of the SiC solid in the central axis direction, very preferably along more than 90% of the extension of the SiC solid in the central axis direction, and most preferably along 100% of the extension of the SiC solid in the central axis direction.

[0305] The ratio U / A between the cross-sectional area A and the perimeter U around the cross-sectional area is preferably higher than 1.2 1 / cm, preferably higher than 1.5 1 / cm, very preferably higher than 2 1 / cm, and most preferably higher than 2.5 1 / cm. The boundary surface preferably surrounds the solid core member. Preferably, the core member comprises or consists of graphite. Alternatively, the core member consists of or comprises SiC. Preferably, the SiC of the core member and the SiC between the outer surface and the boundary surface differ with respect to or at least with respect to the excess C amount per unit volume or the excess Si amount per unit volume. Preferably, the front line between the SiC core member and the boundary surface forms a region having different optical properties compared to the central section of the core member and / or the central section of the SiC solid.

[0306] Since the PVT source material is produced in a CDV reactor, alternatively, this material can be named "material produced in a CDV reactor" or simply "SiC material".

[0307] The object mentioned above is also solved by a PVT source material production method for the production of a PVT source material according to the present invention. The PVT source material production method comprises at least the following steps, namely, the step of providing a source medium inside a processing chamber, in particular of the general formula SiH 4-y X y(A first feed medium, in particular a first source gas, comprising Si according to X = [Cl, F, Br, J] and y = [0...4] and having a purity of at least 99.9999% (weight ppm) excluding substances B, Al, P, Ti, V, Fe, Ni, is introduced into the inside of the processing chamber; a second feed medium, in particular a second source gas, comprising C, in particular natural gas, methane, ethane, propane, butane, and / or acetylene and having a purity of at least 99.9999% excluding substances B, Al, P, Ti, V, Fe, Ni, is introduced into the inside of the processing chamber; and a carrier gas having a purity of at least 99.9999% (weight ppm) excluding substances B, Al, P, Ti, V, Fe, Ni is introduced; or a single feed medium, in particular a source gas, comprising Si and C, in particular SiCl3(CH3) and having a purity of at least 99.9999% (weight ppm) excluding substances B, Al, P, Ti, V, Fe, Ni, is introduced into the inside of the processing chamber, and a carrier gas having a purity of at least 99.9999% (weight ppm) excluding substances B, Al, P, Ti, V, Fe, Ni is introduced; and at least one SiC growth substrate, preferably a plurality of SiC growth substrates, disposed in the processing chamber, each SiC growth substrate comprising a first power connection portion and a second power connection portion, the first power connection portion being a first metal electrode, the second power connection portion being a second metal electrode, the first metal electrode and the second metal electrode preferably electrically activating the SiC growth substrate shielded from the reaction space inside the processing chamber and heating it to a temperature in the range between 1300 °C and 2000 °C; and setting a deposition rate, in particular higher than 200 μm / h, to output Si and C from the source medium and deposit the extracted Si and C as SiC, in particular polycrystalline SiC, on the SiC growth substrate, thereby forming a SiC solid.)

[0308] Setting a pressure higher than 1 bar inside the processing chamber is yet another preferred step of the method. Introducing a mixture of a first source gas providing Si and a second source gas providing C into the inside of the processing chamber in a defined amount that is between 0.32 g per hour per cm2 of the SiC growth surface and 10 g per hour per cm2 of the SiC growth surface is another preferred step of the method. Introducing a Si- and C-containing source gas into the inside of the processing chamber in a defined amount that is between 0.32 g per hour per cm2 of the SiC growth surface and 10 g per hour per cm2 of the SiC growth surface is another preferred step of the method. By introducing a mixture of a first source gas providing Si and a second source gas providing C into the inside of the processing chamber in a defined amount that is between 0.32 g per hour per cm2 of the SiC growth surface and 10 g per hour per cm2 of the SiC growth surface, setting a pressure higher than 1 bar inside the processing chamber is another preferred step of the method. By introducing a Si- and C-containing source gas into the inside of the processing chamber in a defined amount that is between 0.32 g per hour per cm2 of the SiC growth surface and 10 g per hour per cm2 of the SiC growth surface, setting a pressure higher than 1 bar inside the processing chamber is another preferred step of the method. Strengthening the electrical activation of at least one SiC growth substrate over time, in particular heating the surface of the deposited SiC to a temperature between 1300 °C and 1800 °C, is another preferred step of the method. Preferably, the deposition rate is set higher than 200 μm / h, very preferably higher than 500 μm / h, and most preferably higher than 800 μm / h.

[0309] Depositing Si and C at a set deposition rate for longer than 5 hours, in particular longer than 8 hours or up to 8 hours, longer than 12 hours or up to 12 hours, longer than 18 hours or up to 18 hours, preferably longer than 24 hours or up to 24 hours, very preferably longer than 48 hours or up to 48 hours, or most preferably longer than 72 hours or up to 72 hours is another preferred step of the method.

[0310] During the deposition of C and Si, the stage of growing the SiC solid to be heavier than 5 kg, particularly heavier than 25 kg or up to a maximum of 25 kg, preferably heavier than 50 kg or up to a maximum of 50 kg, very preferably heavier than 200 kg or up to a maximum of 200 kg, and most preferably heavier than 500 kg or up to a maximum of 500 kg, and / or during the deposition of C and Si, the stage of growing the SiC solid to a thickness of at least 5 cm, particularly larger than 7 cm or up to a maximum of 7 cm, preferably larger than 10 cm or up to a maximum of 10 cm, preferably larger than 15 cm or up to a maximum of 15 cm, very preferably larger than 20 cm or up to a maximum of 20 cm, and most preferably larger than 50 cm or up to a maximum of 50 cm is another preferred stage of the method.

[0311] Preferably, a control unit is provided for setting the feed medium supply of one or more feed media into the processing chamber, and the control unit is configured to set the feed medium supply between the minimum amount (mass) of the feed medium per minute and the maximum amount (mass) of the feed medium per minute, and preferably, the minimum amount (mass) of the feed medium per minute corresponds to the minimum amount (mass) of the Si deposit and the minimum amount (mass) of the C deposit at a determined growth rate.

[0312] Preferably, the maximum amount of the feed medium supply per minute is at most 30% (mass), at most 20% (mass), at most 10% (mass), at most 5% (mass), or at most 3% (mass) higher compared to the minimum amount of the feed medium supply.

[0313] The processing chamber is at least surrounded by a base plate, a side wall section, and an upper wall section. Preferably, the base plate is provided with at least one cooling element, particularly a base cooling element, for preventing it from being heated above a defined temperature, and / or preferably, the side wall section is provided with at least one cooling element, particularly a bellows cooling element, for preventing it from being heated above a defined temperature, and / or preferably, the upper wall section is provided with at least one cooling element, particularly a bellows cooling element, for preventing it from being heated above a defined temperature. The cooling element is preferably an active cooling element. Preferably, the base plate, the side wall section, and / or the upper wall section are provided with a cooling fluid guiding unit for guiding the cooling fluid, and the cooling fluid guiding unit is configured to limit the heating of the base plate, the side wall section, and / or the upper wall section to a temperature lower than 1300°C. Preferably, a base plate sensor unit, a side wall section sensor unit, and / or an upper wall section sensor unit for detecting the temperature of the base plate, the side wall section, and / or the upper wall section and outputting a temperature signal or temperature data is provided, and / or a cooling fluid temperature sensor for detecting the temperature of the cooling fluid is provided. Further, preferably, a fluid forward feeding unit for feeding the cooling fluid forward through the fluid guiding unit is provided, and preferably, the fluid forward feeding unit is configured to operate depending on the temperature signal or temperature data provided by the base plate sensor unit, the side wall section sensor unit, and / or the upper wall section sensor unit, and / or the cooling fluid temperature sensor. Preferably, the cooling fluid is oil or water, and preferably, the water comprises at least one additive, particularly a rust inhibitor and / or an antifouling agent (biocide). The cooling element can be, in addition to or instead of this, a passive cooling element. Preferably, the cooling element is at least partially formed by a polished steel surface of the base plate, the side wall section, and / or the upper wall section. The cooling element is preferably a coating, and the coating is formed on the polished steel surface and is configured to reflect heat.Preferably, the coating is a metal coating or comprises a coating of metal, in particular silver, gold, chromium, or an alloy, in particular a CuNi alloy. The emissivity of the polished steel surface and / or the coating is preferably less than εe 0.3, in particular less than 0.1 or less than 0.03. Preferably, the base plate comprises at least one active cooling element and one passive cooling element to prevent it from being heated above a defined temperature, and / or preferably, the side wall section comprises at least one active cooling element and one passive cooling element to prevent it from being heated above a defined temperature, and / or preferably, the upper wall section comprises at least one active cooling element and one passive cooling element to prevent it from being heated above a defined temperature. The side wall section and the upper wall section are preferably formed by a bell jar, and preferably, the bell jar is movable relative to the base plate. Preferably, more than 50% (by mass) of the side wall section, more than 50% (by mass) of the upper wall section, and / or more than 50% (by mass) of the base plate are made of metal, in particular steel.

[0314] Preferably, a gas outlet unit for outputting ventilation gas and a ventilation gas recirculation unit are provided, and preferably, they are operated according to the above-described method. The ventilation gas recirculation unit is connected to the gas outlet unit and includes at least one separation unit for separating the ventilation gas into a first fluid and a second fluid, the first fluid being a liquid and the second fluid being a gas. The first storage element and / or conduction element for storing or conducting the first fluid is part of or coupled to the separation unit, and the second storage element and / or conduction element for storing or conducting the second fluid is part of or coupled to the separation unit. Preferably, the step of providing the source medium inside the processing chamber includes the step of feeding the first fluid from the ventilation gas recirculation unit inside the processing chamber, and the first fluid includes at least a chlorosilanes mixture. Preferably, the ventilation gas recirculation unit separates the first fluid into at least two parts, namely, a chlorosilanes mixture and a mixture of HCl, H2, and at least one C-containing molecule, and preferably, further includes another separation unit for separating it into at least three parts, namely, a chlorosilanes mixture, HCl, and a mixture of H2 and at least one C-containing molecule. The first storage element and / or conduction element is connected to another separation unit, and the another separation unit is coupled to the storage element and / or conduction element of the chlorosilanes mixture, the storage element and / or conduction element of HCl, and the storage element and / or conduction element of H2 and C. The storage element and / or conduction element of the chlorosilanes mixture forms a section of the chlorosilanes mixture mass flux path for conducting the chlorosilanes mixture inside the processing chamber. The Si mass flux measurement unit for measuring the amount of Si in the chlorosilanes mixture is preferably provided as another Si feed medium source for providing another Si feed medium as part of the mass flux path before the processing chamber, particularly before the mixing device.

[0315] Preferably, the SiC growth substrate has an average perimeter of at least 5 cm around a cross-sectional area orthogonal to its length direction, or a plurality of SiC growth substrates each have an average perimeter of at least 5 cm around a cross-sectional area orthogonal to the length direction of each respective SiC growth substrate.

[0316] Since the PVT source material is produced in a CDV reactor, instead, the PVT source material production method can be named as "SiC material production method carried out using a CVD reactor" or simply "SiC material production method".

[0317] The above-mentioned object is also solved by a PVT source material composed of SiC particles having an average length longer than 100 μm, an impurity of substance N lower than 10 ppm (by weight), and an impurity of each of substances B, Al, P, Ti, V, Fe, Ni lower than 1000 ppb (by weight), particularly lower than 500 ppb (by weight).

[0318] This solution is beneficial because very high-purity particles with a size (length) larger than 100 μm have particularly advantageous properties as a PVT source material.

[0319] Preferably, the SiC particles have an impurity of substance N lower than 2 ppm (by weight) and an impurity of each of substances B, Al, P, Ti, V, Fe, Ni lower than 100 ppb (by weight), and very preferably, an impurity of substance Ti lower than 10 ppb (by weight). In addition to or instead of this, preferably, the SiC particles have an impurity of substance N lower than 10 ppm (by weight) and a total impurity of all of metals Ti, V, Fe, Ni lower than 1000 ppb (by weight), particularly lower than 500 ppb (by weight).

[0320] The apparent density of the SiC particles is preferably higher than 1.4 g / cm3, and very preferably higher than 1.6 g / cm3. The tap density of the SiC particles is preferably higher than 1.6 g / cm3, and very preferably higher than 1.8 g / cm3. Here, the apparent density is measured in accordance with ISO697, and the tap density is measured in accordance with ISO787.

[0321] Preferably, the PVT source material is produced according to a PVT source material production method for the production of the PVT source material, and the PVT source material production method is a step of supplying a source medium inside a processing chamber, particularly a general formula SiH 4-y X y(Introducing at least a first feed medium, in particular a first source gas, having a purity of at least 99.9999% (weight ppm) excluding substances B, Al, P, Ti, V, Fe, Ni and comprising Si according to X = [Cl, F, Br, J] and y = [0...4] into the inside of the processing chamber; introducing at least a second feed medium, in particular a second source gas, having a purity of at least 99.9999% (weight ppm) excluding substances B, Al, P, Ti, V, Fe, Ni and comprising C, in particular natural gas, methane, ethane, propane, butane, and / or acetylene into the inside of the processing chamber; introducing a carrier gas having a purity of at least 99.9999% (weight ppm) excluding substances B, Al, P, Ti, V, Fe, Ni; or introducing one feed medium, in particular a source gas, having a purity of at least 99.9999% (weight ppm) excluding substances B, Al, P, Ti, V, Fe, Ni and comprising Si and C, in particular SiCl3(CH3) into the inside of the processing chamber; introducing a carrier gas having a purity of at least 99.9999% (weight ppm) excluding substances B, Al, P, Ti, V, Fe, Ni; electrically activating at least one SiC growth substrate, preferably a plurality of SiC growth substrates, arranged in the processing chamber and heating it to a temperature in the range between 1300 °C and 2000 °C; setting a deposition rate, in particular higher than 200 μm / h, in order to output Si and C from the source medium and deposit the extracted Si and C on the SiC growth substrate as SiC, in particular polycrystalline SiC, thereby forming a SiC solid; and de-aggregating the SiC solid into SiC particles having an average length longer than 100 μm. Preferably, the PVT source material is polytype 3C SiC and / or polycrystalline SiC. The average length of the SiC particles is preferably longer than 500 μm, very preferably longer than 1000 μm, and most preferably longer than 2000 μm. Preferably, the SiC particles comprise an excess C lower than 30% (mass), preferably lower than 20% (mass), very preferably lower than 10% (mass), or most preferably lower than 5% (mass) compared to the ideal stoichiometric ratio of Si and C.)Preferably, the SiC particles have an excess Si of less than 30% (by mass), preferably less than 20% (by mass), more preferably less than 10% (by mass), or most preferably less than 5% (by mass) compared to the ideal stoichiometric ratio of Si and C.

[0322] Since the PVT source material is produced in a CDV reactor, instead, this material can be named "material produced in a CDV reactor" or simply "SiC material".

[0323] The above-mentioned object is also solved by a PVT source material lot. This PVT source material lot comprises at least 1 kg of the PVT source material according to the present invention.

[0324] The above-mentioned object is also solved by a PVT source material production method for producing the PVT source material according to the present invention. Preferably, the PVT source material production method is a step of supplying a source medium inside a processing chamber, particularly of the general formula SiH 4-y X y(A first feed medium, in particular a first source gas, having Si according to X = [Cl, F, Br, J] and y = [0...4] and having a purity of at least 99.9999% (weight ppm) excluding substances B, Al, P, Ti, V, Fe, Ni, is introduced into a processing chamber (856); a second feed medium, in particular a second source gas, having C, in particular natural gas, methane, ethane, propane, butane, and / or acetylene and having a purity of at least 99.9999% excluding substances B, Al, P, Ti, V, Fe, Ni, is introduced inside the processing chamber; and a carrier gas having a purity of at least 99.9999% (weight ppm) excluding substances B, Al, P, Ti, V, Fe, Ni is introduced. Alternatively, a single feed medium, in particular a source gas, having Si and C, in particular SiCl3(CH3) and having a purity of at least 99.99999% (weight ppm) excluding substances B, Al, P, Ti, V, Fe, Ni, is introduced into the processing chamber (856); and a carrier gas having a purity of at least 99.99999% (weight ppm) excluding substances B, Al, P, Ti, V, Fe, Ni is introduced. The above-providing step includes electrically activating at least one SiC growth substrate disposed in the processing chamber, preferably a plurality of SiC growth substrates, each SiC growth substrate having a first power connection portion and a second power connection portion, the first power connection portion being a first metal electrode and the second power connection portion being a second metal electrode, the first metal electrode and the second metal electrode preferably being electrically isolated from the reaction space inside the processing chamber, and heating it to a temperature in the range between 1300 °C and 2000 °C; setting a deposition rate, in particular higher than 200 μm / h, to output Si and C from the source medium and deposit the extracted Si and C as SiC, in particular polycrystalline SiC, on the SiC growth substrate, thereby forming a SiC solid; and deaggregating the SiC solid into SiC particles having an average length longer than 100 μm. This method is beneficial because it can produce very high-purity SiC materials on an industrial scale.)

[0325] (Setting a pressure higher than 1 bar inside the processing chamber is a preferred step of the method.)

[0326] Another preferred step of the method is to introduce into the inner side of the processing chamber a mixture of a first source gas providing Si and a second source gas providing C in a defined amount which is between 0.32 g per hour per 1 cm2 of the SiC growth surface and 10 g per hour per 1 cm2 of the SiC growth surface. Alternatively, another preferred step of the method is to introduce into the inner side of the processing chamber a defined amount of a Si- and C-containing source gas which is between 0.32 g per hour per 1 cm2 of the SiC growth surface and 10 g per hour per 1 cm2 of the SiC growth surface. Alternatively, another preferred step of the method is to set a pressure higher than 1 bar inside the processing chamber by introducing into the inner side of the processing chamber a mixture of a first source gas providing Si and a second source gas providing C in a defined amount which is between 0.32 g per hour per 1 cm2 of the SiC growth surface and 10 g per hour per 1 cm2 of the SiC growth surface. The alternative step is to set a pressure higher than 1 bar inside the processing chamber by introducing into the inner side of the processing chamber a defined amount of a Si- and C-containing source gas which is between 0.32 g per hour per 1 cm2 of the SiC growth surface and 10 g per hour per 1 cm2 of the SiC growth surface.

[0327] Another preferred step of the method is to enhance the electrical activation of at least one SiC growth substrate over time, in particular to heat the surface of the deposited SiC to a temperature between 1300 °C and 1800 °C. Preferably, the deposition rate is set higher than 200 μm / h, very preferably higher than 500 μm / h, and most preferably higher than 800 μm / h.

[0328] The step of depositing Si and C at a set deposition rate for longer than 5 hours, in particular longer than 8 hours or up to 8 hours, longer than 12 hours or up to 12 hours, longer than 18 hours or up to 18 hours, preferably longer than 24 hours or up to 24 hours, very preferably longer than 48 hours or up to 48 hours, or most preferably longer than 72 hours or up to 72 hours is another preferred step of the method.

[0329] The step of growing SiC solid heavier than 5 kg, in particular heavier than 25 kg or up to 25 kg, preferably heavier than 50 kg or up to 50 kg, very preferably heavier than 200 kg or up to 200 kg, most preferably heavier than 500 kg or up to 500 kg during the deposition of C and Si, and the step of growing SiC solid to a thickness of at least 5 cm, in particular larger than 7 cm or up to 7 cm, preferably larger than 10 cm or up to 10 cm, preferably larger than 15 cm or up to 15 cm, very preferably larger than 20 cm or up to 20 cm, most preferably larger than 50 cm or up to 50 cm during the deposition of C and Si are another preferred steps of the method.

[0330] Preferably, a control unit is provided for setting the feed medium supply of one or more feed media into the processing chamber, and the control unit can be configured to set the feed medium supply between the minimum amount (mass) of the feed medium supply per minute and the maximum amount (mass) of the feed medium supply per minute. Preferably, the minimum amount (mass) of the feed medium supply per minute corresponds to the minimum amount (mass) of the Si deposit and the minimum amount (mass) of the C deposit at a defined growth rate.

[0331] Preferably, the maximum amount of the feed medium supply per minute is at most 30% (mass), at most 20% (mass), at most 10% (mass), at most 5% (mass), or at most 3% (mass) higher compared to the minimum amount of the feed medium supply.

[0332] The processing chamber is at least surrounded by a base plate, a side wall section, and an upper wall section. Preferably, the base plate includes at least one cooling element, particularly a base cooling element, to prevent it from being heated above a defined temperature, and / or preferably, the side wall section includes at least one cooling element, particularly a baffle cooling element, to prevent it from being heated above a defined temperature, and / or preferably, the upper wall section includes at least one cooling element, particularly a baffle cooling element, to prevent it from being heated above a defined temperature. The cooling element is preferably an active cooling element. Preferably, the base plate, the side wall section, and / or the upper wall section include a cooling fluid guiding unit for guiding a cooling fluid, and the cooling fluid guiding unit is configured to limit the heating of the base plate, the side wall section, and / or the upper wall section to a temperature lower than 1300 °C. Preferably, a base plate sensor unit, a side wall section sensor unit, and / or an upper wall section sensor unit are provided for detecting the temperature of the base plate, the side wall section, and / or the upper wall section and outputting a temperature signal or temperature data, and / or a cooling fluid temperature sensor is provided for detecting the temperature of the cooling fluid. Further, preferably, a fluid forward feeding unit is provided for feeding the cooling fluid forward through the fluid guiding unit. Preferably, the fluid forward feeding unit is configured to operate depending on the temperature signal or temperature data provided by the base plate sensor unit, the side wall section sensor unit, and / or the upper wall section sensor unit and / or the cooling fluid temperature sensor. Preferably, the cooling fluid is oil or water, and preferably, the water includes at least one additive, particularly a rust inhibitor and / or an antifouling agent (biocide). The cooling element can be, in addition to or instead of this, a passive cooling element. Preferably, the cooling element is at least partially formed by a polished steel surface of the base plate, the side wall section, and / or the upper wall section. The cooling element is preferably a coating, and the coating is formed on the polished steel surface and configured to reflect heat.Preferably, the coating is a metal coating or comprises a coating of metal, in particular silver, gold, chromium, or an alloy, in particular a CuNi alloy. The emissivity of the polished steel surface and / or the coating is preferably less than εe 0.3, in particular less than 0.1 or less than 0.03. Preferably, the base plate comprises at least one active cooling element and one passive cooling element to prevent it from being heated above a defined temperature, and / or preferably, the side wall section comprises at least one active cooling element and one passive cooling element to prevent it from being heated above a defined temperature, and / or preferably, the upper wall section comprises at least one active cooling element and one passive cooling element to prevent it from being heated above a defined temperature. The side wall section and the upper wall section are preferably formed by a bell jar, and preferably, the bell jar is movable relative to the base plate. Preferably, more than 50% (by mass) of the side wall section, more than 50% (by mass) of the upper wall section, and / or more than 50% (by mass) of the base plate are made of metal, in particular steel.

[0333] Preferably, a gas outlet unit for outputting ventilation gas and a ventilation gas recirculation unit are provided, and preferably, they are operated according to the above-described method. The ventilation gas recirculation unit is connected to the gas outlet unit and includes at least one separation unit for separating the ventilation gas into a first fluid and a second fluid, the first fluid is a liquid, the second fluid is a gas, the first storage element and / or conduction element for storing or conducting the first fluid is part of or coupled to the separation unit, and the second storage element and / or conduction element for storing or conducting the second fluid is part of or coupled to the separation unit. Preferably, the step of providing the source medium inside the processing chamber includes the step of feeding the first fluid from the ventilation gas recirculation unit to the inside of the processing chamber, and the first fluid includes at least a chlorosilanes mixture. Preferably, the ventilation gas recirculation unit separates the first fluid into at least two parts, namely, a chlorosilanes mixture and a mixture of HCl, H2, and at least one C-containing molecule, and preferably, further includes another separation unit for separating it into at least three parts, namely, a chlorosilanes mixture, HCl, and a mixture of H2 and at least one C-containing molecule. The first storage element and / or conduction element is connected to another separation unit, and the another separation unit is coupled to the storage element and / or conduction element of the chlorosilanes mixture, the storage element and / or conduction element of HCl, and the storage element and / or conduction element of H2 and C. The storage element and / or conduction element of the chlorosilanes mixture forms a section of the mass flux path of the chlorosilanes mixture for conducting it inside the processing chamber, and the Si mass flux measurement unit for measuring the amount of Si in the chlorosilanes mixture is preferably provided as another Si feed medium source that provides another Si feed medium as part of the mass flux path before the processing chamber, particularly before the mixing device.

[0334] Preferably, the SiC growth substrate has an average perimeter of at least 5 cm around a cross-sectional area orthogonal to its length direction, or a plurality of SiC growth substrates each have an average perimeter of at least 5 cm around a cross-sectional area orthogonal to the length direction of each SiC growth substrate.

[0335] Since the PVT source material is produced in a CDV reactor, instead, the PVT source material production method can be named as "SiC material production method implemented using a CVD reactor" or simply "SiC material production method".

[0336] The above-mentioned object is also solved by a method for the production of at least one SiC crystal. The method comprises the steps of providing a CVD reactor for the production of a first type of SiC, introducing at least one source gas, in particular a first source gas, in particular SiCl3(CH3), into the processing chamber to generate a source medium comprising Si and C, preferably introducing at least one carrier gas comprising H into the processing chamber, electrically activating at least one SiC growth substrate disposed in the processing chamber to heat its surface to a temperature within the range between 1300 °C and 1800 °C, depositing a first type of SiC on the SiC growth substrate, in particular at a deposition rate higher than 200 μm / h, wherein the SiC deposit is preferably polycrystalline SiC, outputting the first type of deposited SiC from the CVD reactor, transforming the extracted SiC into a first type of fragmented SiC or one or more first type of solid SiC, and providing a PVT reactor for the production of a second type of SiC. The PVT reactor comprises a furnace unit having a furnace housing with an outer surface and an inner surface, at least one crucible unit comprising a crucible housing disposed inside the furnace housing, the crucible housing having an outer surface and an inner surface, the inner surface at least partially defining a crucible volume, a receiving space for receiving a source material being disposed or formed inside the crucible volume, a seed holder unit for holding a defined seed wafer being disposed inside the crucible volume, the seed wafer holder holding the seed wafer, the inner wall of the furnace housing and the outer wall of the crucible housing defining the furnace volume together with the crucible unit, and at least one heating unit for heating the source material, the receiving space for receiving the source material being at least partially disposed above the heating unit and below the seed holder unit.The method further includes adding fragmented SiC of the first type into the receiving space or adding one or more solids of the first type of SiC as source material, sublimating the first type of SiC inside a PVT reactor, and depositing the sublimated SiC onto a seed wafer as the second type of SiC. The method is beneficial because both the PVT source material and the SiC crystal are produced with very high quality in a very efficient manner.

[0337] Preferably, the step of introducing at least one source gas and at least one carrier gas comprises a Si feed medium source that provides a Si gas having SiH 4-y X y (where X = [Cl, F, Br, J] and y = [0...4], and introducing at least a first feed medium, particularly the first source gas, having a purity of at least 99.9999% (weight ppm) excluding substances B, Al, P, Ti, V, Fe, Ni, into the inside of the processing chamber; a C, particularly natural gas, methane, ethane, propane, butane, and / or acetylene, and introducing at least a second feed medium, particularly the second source gas, having a purity of at least 99.9999% excluding substances B, Al, P, Ti, V, Fe, Ni, into the inside of the processing chamber; and introducing a carrier gas having a purity of at least 99.9999% (weight ppm) excluding substances B, Al, P, Ti, V, Fe, Ni). Alternatively, the step of introducing at least one source gas and at least one carrier gas preferably comprises introducing one feed medium, particularly a source gas, having a purity of at least 99.9999% (weight ppm) excluding substances B, Al, P, Ti, V, Fe, Ni and comprising Si and C, particularly SiCl3(CH3), into the inside of the processing chamber, and introducing a carrier gas having a purity of at least 99.9999% (weight ppm) excluding substances B, Al, P, Ti, V, Fe, Ni. Preferably, the fragmented SiC corresponds to SiC particles having an average length of at least 100 μm.

[0338] Preferably, the SiC particles have impurities of substance N lower than 10 ppm (by weight), and impurities of each of substances B, Al, P, Ti, V, Fe, Ni lower than 1000 ppb (by weight), particularly lower than 500 ppb (by weight). Very preferably, they have impurities of substance N lower than 2 ppm (by weight) and impurities of each of substances B, Al, P, Ti, V, Fe, Ni lower than 100 ppb (by weight) or impurities of substance Ti lower than 10 ppb (by weight). Alternatively, the SiC particles have impurities of substance N lower than 10 ppm (by weight), and the total impurities of all of metals Ti, V, Fe, Ni lower than 1000 ppb (by weight), particularly lower than 500 ppb (by weight). The apparent density of the SiC particles is preferably higher than 1.4 g / cm3, and very preferably higher than 1.6 g / cm3. The tap density of the SiC particles is preferably higher than 1.6 g / cm3, and very preferably higher than 1.8 g / cm3.

[0339] Preferably, each of one or more solids of SiC weighs more than 0.3 kg, preferably has a mass of at least 1 kg, a thickness of at least 1 cm, preferably at least 5 cm, a length longer than 10 cm, preferably at least 25 cm or at least 50 cm, and is characterized by impurities of substance N lower than 10 ppm (by weight) and impurities of each of substances B, Al, P, Ti, V, Fe, Ni lower than 1000 ppb (by weight), particularly lower than 500 ppb (by weight). Preferably, each of one or more solids of SiC has impurities of substance N lower than 2 ppm (by weight) and impurities of each of substances B, Al, P, Ti, V, Fe, Ni lower than 100 ppb (by weight) or impurities of substance Ti lower than 10 ppb (by weight). Alternatively, each of one or more solids of SiC has impurities of substance N lower than 10 ppm (by weight), and the total impurities of all of metals Ti, V, Fe, Ni lower than 1000 ppb (by weight), particularly lower than 500 ppb (by weight).

[0340] Setting a pressure higher than 1 bar inside the processing chamber is another preferred step of the method.

[0341] Another preferred step of the method is to introduce into the interior of the processing chamber a defined amount of a mixture of a first source gas providing Si and a second source gas providing C, the amount of the mixture being between 0.32 g per hour per cm² of the SiC growth surface and 10 g per hour per cm² of the SiC growth surface. Alternatively, another preferred step of the method is to introduce into the interior of the processing chamber a defined amount of a Si- and C-containing source gas, the amount of the Si- and C-containing source gas being between 0.32 g per hour per cm² of the SiC growth surface and 10 g per hour per cm² of the SiC growth surface. Alternatively, another preferred step of the method is to set a pressure higher than 1 bar in the interior of the processing chamber by introducing into the interior of the processing chamber a defined amount of a mixture of a first source gas providing Si and a second source gas providing C, the amount of the mixture being between 0.32 g per hour per cm² of the SiC growth surface and 10 g per hour per cm² of the SiC growth surface. Alternatively, another preferred step of the method is to set a pressure higher than 1 bar in the interior of the processing chamber by introducing into the interior of the processing chamber a defined amount of a Si- and C-containing source gas, the amount of the Si- and C-containing source gas being between 0.32 g per hour per cm² of the SiC growth surface and 10 g per hour per cm² of the SiC growth surface. Preferably, the processing chamber is surrounded by a base plate, a side wall section, and an upper wall section, and more than 50% of the side wall section, more than 50% of the upper wall section, and more than 50% of the base plate are made of metal, particularly steel. Preferably, a base plate sensor unit, a side wall section sensor unit, and / or an upper wall section sensor unit for detecting the temperature of the base plate, the side wall section, and / or the upper wall section and outputting a temperature signal or temperature data is provided, and / or a cooling fluid temperature sensor for detecting the temperature of the cooling fluid is provided, and further preferably, a fluid feeding unit for feeding the cooling fluid forward through a fluid guiding unit is provided. Preferably, the fluid feeding unit is configured to operate depending on the temperature signal or temperature data provided by the base plate sensor unit, the side wall section sensor unit, and / or the upper wall section sensor unit, and / or the cooling fluid temperature sensor.Preferably, the SiC growth substrate has an average perimeter of at least 5 cm around a cross-sectional area orthogonal to its length direction, or a plurality of SiC growth substrates each have an average perimeter of at least 5 cm around a cross-sectional area orthogonal to the length direction of each SiC growth substrate. The SiC deposited on the SiC growth substrate preferably has impurities of substance N lower than 10 ppm (by weight) and impurities of each of substances B, Al, P, Ti, V, Fe, Ni lower than 1000 ppb (by weight), particularly lower than 500 ppb (by weight), and very preferably has impurities of substance N lower than 2 ppm (by weight) and impurities of each of substances B, Al, P, Ti, V, Fe, Ni lower than 100 ppb (by weight) or impurities of substance Ti lower than 10 ppb (by weight). Alternatively, the SiC deposited on the SiC growth substrate has impurities of substance N lower than 10 ppm (by weight) and total impurities of all of metals Ti, V, Fe, Ni lower than 1000 ppb (by weight), particularly lower than 500 ppb (by weight). Preferably, the gas outlet unit for outputting the ventilation gas and the ventilation gas recirculation unit are provided as units operated according to a part of the method of the present invention, the ventilation gas recirculation unit is connected to the gas outlet unit, and includes at least one separation unit for separating the ventilation gas into a first fluid and a second fluid, the first fluid is a liquid, the second fluid is a gas, the first storage element and / or conduction element for storing or conducting the first fluid is part of or coupled to the separation unit, and the second storage element and / or conduction element for storing or conducting the second fluid is part of or coupled to the separation unit. Further, the method preferably includes a step of supplying a source medium inside the processing chamber, and preferably this step includes a step of feeding the first fluid from the ventilation gas recirculation unit inside the processing chamber, and the first fluid includes at least a chlorosilane mixture. Preferably, the gas introduced into the CVD reactor includes one, a plurality, or all of substances B (boron), Al (aluminum), P (phosphorus), Ti (titanium), V (vanadium), Fe (iron), Ni (nickel) lower than 99.9999% (by weight ppm).Preferably, a crucible gas flow unit for providing a gas flow inside the crucible volume is provided, the crucible gas flow unit comprising a crucible gas inlet tube for conducting gas into the crucible volume and a crucible gas outlet tube for conducting gas out of the crucible volume. Preferably, a growth guide is arranged inside the crucible housing, the growth guide forming a growth-guide-gas-path-section-boundary for guiding the gas flow in the direction of the seed holder unit, and the growth guide and the seed holder unit forming a gas flow path. Preferably, the method comprises establishing a gas flow through the crucible volume by conducting at least a carrier gas into the crucible volume through the crucible gas inlet tube and conducting a...

Claims

1. A method for generating at least one SiC crystal, comprising: providing a CVD reactor (850) for the production of a first type of SiC; introducing at least one source gas, in particular a first source gas, in particular SiCl3(CH3), into a processing chamber (856) to generate a source medium comprising Si and C; introducing at least one carrier gas, preferably comprising H, into the processing chamber (856); electrically activating at least one SiC growth substrate (857) disposed in the processing chamber (856) to heat the SiC growth substrate (857), wherein the surface of the SiC growth substrate (857) is heated to a temperature in the range between 1300 °C and 1800 °C; said electrically activating step; depositing the first type of SiC on the SiC growth substrate (857) at a deposition rate particularly higher than 200 μm / h, said deposited SiC being preferably polycrystalline SiC; removing the deposited SiC of the first type from the CVD reactor (850); transforming the removed SiC into fragmented SiC of the first type or into one or more solids of the first type of SiC; providing a PVT reactor (100) for the production of a second type of SiC, wherein the PVT reactor (100) comprises a furnace unit (102) comprising a furnace housing (108) having an outer surface (242) and an inner surface (240), at least one crucible unit (106), wherein the crucible unit (106) is disposed inside the furnace housing (108), the crucible housing (110) comprising a crucible housing (110), the crucible housing (110) having an outer surface (112) and an inner surface (114) at least partially defining a crucible volume (116), a receiving space (118) for receiving a source material (120) being disposed or formed inside the crucible volume (116), a seed holder unit (122) for holding a defined seed wafer (18) being disposed inside the crucible volume (116), the seed wafer holder (122) holding the seed wafer (18), wherein the inner wall (240) of the furnace housing and the outer wall (112) of the crucible housing define a furnace volume (104). the crucible unit (106), and at least one heating unit (124) for heating the source material (120), wherein the receiving space (118) for receiving the source material (120) is at least partially disposed above the heating unit (124) and below the seed holder unit (122), the heating unit (124), and comprising the providing step, the step of adding the fragmented SiC of the first type into the receiving space (118) or the step of adding one or more solids of the first type of SiC as the source material (120), the step of sublimating the first type of SiC inside the PVT reactor (100), the step of depositing the sublimated SiC onto the seed wafer (18) as the second type of SiC, A method characterized by comprising.

2. The step of introducing at least one source gas and at least one carrier gas At least a first feed medium, in particular, introducing the first source gas into the processing chamber (856), wherein the first feed medium comprises Si, in particular, the Si feed medium source has the general formula SiH 4-y X y (X = [Cl, F, Br, J] and y = [0 providing Si gas according to...4], and the introducing step in which the first feed medium has a purity excluding substances B, Al, P, Ti, V, Fe, Ni of at least 99.9999% (weight ppm), and introducing at least a second feed medium, in particular a second source gas, into the processing chamber (856), the second feed medium comprising C, in particular natural gas, methane, ethane, propane, butane, and / or acetylene, and the second feed medium having a purity excluding substances B, Al, P, Ti, V, Fe, Ni of at least 99.9999% (weight ppm), and introducing a carrier gas having a purity excluding substances B, Al, P, Ti, V, Fe, Ni of at least 99.9999% (weight ppm), or introducing one feed medium, in particular a source gas, into the processing chamber (856), the feed medium comprising Si and C, in particular SiCl3(CH3), and the introducing step in which the feed medium has a purity excluding substances B, Al, P, Ti, V, Fe, Ni of at least 99.9999% (weight ppm), and introducing a carrier gas having a purity excluding substances B, Al, P, Ti, V, Fe, Ni of at least 99.9999% (weight ppm), comprising The method according to claim 1, characterized by this.

3. The fragmented SiC represents SiC particles (920) having an average length of at least 100 μm, The method according to claim 2, characterized in that.

4. The SiC particles (920) have impurities of substance N lower than 10 ppm (by weight), and impurities of each of the substances B, Al, P, Ti, V, Fe, Ni lower than 1000 ppb (by weight), particularly lower than 500 ppb (by weight). The method according to claim 3, characterized in that.

5. The SiC particles (920) have impurities of substance N lower than 2 ppm (by weight), and impurities of each of the substances B, Al, P, Ti, V, Fe, Ni lower than 100 ppb (by weight). The method according to claim 4, characterized in that.

6. The SiC particles (920) have impurities of substance Ti lower than 10 ppb (by weight). The method according to claim 5, characterized in that.

7. The SiC particles have impurities of substance N lower than 10 ppm (by weight), and total impurities of all of the metals Ti, V, Fe, Ni lower than 1000 ppb (by weight), particularly lower than 500 ppb (by weight). The method according to claim 4, characterized in that.

8. The apparent density of the SiC particles (920) is higher than 1.4 g / cm3. The method according to any one of claims 5 to 7, characterized in that.

9. The apparent density of the SiC particles (920) is higher than 1.6 g / cm3. The method according to claim 8, characterized in that.

10. The tap density of the SiC particles (920) is higher than 1.6 g / cm3. The method according to claim 8 or claim 9, characterized in that.

11. The tap density of the SiC particles (920) is higher than 1.8 g / cm3. The method according to claim 10, characterized in that.

12. Each of the one or more solids of SiC is heavier than 0.3 kg, preferably having a mass of at least 1 kg, having a thickness of at least 1 cm, preferably at least 5 cm, longer than 10 cm, preferably having a length of at least 25 cm or at least 50 cm, having impurities of substance N lower than 10 ppm (by weight), and impurities of each of the substances B, Al, P, Ti, V, Fe, Ni lower than 1000 ppb (by weight), particularly lower than 500 ppb (by weight), characterized by The method according to claim 2, characterized in that...

13. Each of said one or more solids of SiC has impurities of said substance N lower than 2 ppm (by weight) and impurities of each of said substances B, Al, P, Ti, V, Fe, Ni lower than 100 ppb (by weight). The method according to claim 12, characterized in that...

14. Each of said one or more solids of SiC has impurities of said substance Ti lower than 10 ppb (by weight). The method according to claim 13, characterized in that...

15. Each of said one or more solids of SiC has impurities of said substance N lower than 10 ppm (by weight) and total impurities of all of said metals Ti, V, Fe, Ni lower than 1000 ppb (by weight), particularly lower than 500 ppb (by weight). The method according to claim 12, characterized in that...

16. A step of setting a pressure higher than 1 bar inside said processing chamber (856) by introducing a defined amount of a mixture of said first source gas providing Si and said second source gas providing C into said processing chamber, wherein the defined amount is 0.32 g of said mixture per hour and per cm2 of the SiC growth surface and 10 g of the Si- and C-containing source gas per hour and per cm2 of the SiC growth surface, and the amount is between them, said step of setting, or A step of setting a pressure higher than 1 bar inside said processing chamber (856) by introducing a defined amount of one or more Si- and C-containing source gases into said processing chamber, wherein the defined amount is 0.32 g of said one or more Si- and C-containing source gases per hour and per cm2 of the SiC growth surface and 10 g of the Si- and C-containing source gas per hour and per cm2 of the SiC growth surface, and the amount is between them, said step of setting, The method according to any one of claims 8 to 11 or any one of claims 14 to 15, characterized by...

17. A step of setting a pressure higher than 1 bar inside said processing chamber (856). The method according to any one of claims 8 to 11 or any one of claims 14 to 15, characterized by...

18. The processing chamber (856) is surrounded by a base plate (862), side wall sections (864a), and an upper wall section (864b), with more than 50% (by mass) of the side wall sections, more than 50% (by mass) of the upper wall section, and more than 50% (by mass) of the base plate made of metal, particularly steel. The method according to claim 17, characterized in that.

19. A base plate and / or side wall section sensor and / or upper wall section sensor unit is provided for detecting the temperature of the base plate and / or side wall section and / or upper wall section and for outputting a temperature signal or temperature data, and / or a cooling fluid temperature sensor is provided for detecting the temperature of the cooling fluid. A fluid feeding unit for feeding the cooling fluid forward through a fluid guiding unit is provided. The method according to claim 18, characterized in that.

20. The fluid feeding unit is configured to operate depending on the temperature signal or temperature data provided by the base plate and / or side wall section and / or upper wall section sensor unit and / or the cooling fluid temperature sensor. The method according to claim 19, characterized in that.

21. The SiC growth substrate has an average perimeter of at least 5 cm around a cross-sectional area orthogonal to the length direction of the SiC growth substrate, or a plurality of SiC growth substrates each have an average perimeter per SiC growth substrate of at least 5 cm around a cross-sectional area orthogonal to the length direction of each respective SiC growth substrate. The method according to any one of claims 14 to 20, characterized in that.

22. The SiC deposited on the SiC growth substrate (857) has impurities of the substance N lower than 10 ppm (by weight) and impurities of each of the substances B, Al, P, Ti, V, Fe, Ni lower than 1000 ppb (by weight), preferably lower than 500 ppb (by weight). The method according to any one of claims 14 to 21, characterized in that.

23. The SiC deposited on the SiC growth substrate (857) has impurities of the substance N lower than 2 ppm (by weight) and impurities of each of the substances B, Al, P, Ti, V, Fe, Ni lower than 100 ppb (by weight). The method according to claim 22, characterized in that.

24. The SiC deposited on the SiC growth substrate (857) has an impurity of the substance Ti that is lower than 10 ppb (by weight). The method according to claim 23, characterized in that.

25. The SiC deposited on the SiC growth substrate (857) has an impurity of the substance N that is lower than 10 ppm (by weight), and a total impurity of all of the metals Ti, V, Fe, Ni that is lower than 1000 ppb (by weight), particularly 500 ppb (by weight). The method according to claim 22, characterized in that.

26. A gas outlet unit for outputting a ventilation gas, A ventilation gas recirculation unit, The ventilation gas recirculation unit is connected to the gas outlet unit, The ventilation gas recirculation unit includes at least a separation unit for separating the ventilation gas into a first fluid and a second fluid, The first fluid is a liquid, and the second fluid is a gas, A first storage and / or conduction element for storing or conducting the first fluid is part of or coupled to the separation unit, and A second storage and / or conduction element for storing or conducting the second fluid is part of or coupled to the separation unit. The ventilation gas recirculation unit, The method according to any one of claims 14 to 25, characterized in that.

27. The step of providing the source medium inside the processing chamber includes the step of feeding a first fluid comprising at least a mixture of chlorosilanes from the ventilation gas recirculation unit into the processing chamber. The method according to claim 26, characterized in that.

28. The gas introduced into the CVD reactor 850 includes one, a plurality, or all of the following substances that are lower than 99.9999% (weight ppm), namely, B (boron), Al (aluminum), P (phosphorus), Ti (titanium), V (vanadium), Fe (iron), Ni (nickel). The method according to any one of claims 14 to 27, characterized in that.

29. A crucible gas flow unit (170) for causing a gas flow is provided inside the crucible volume, and the crucible gas flow unit (170) includes a crucible gas inlet tube (172) for conducting gas into the crucible volume (116) and a crucible gas outlet tube (174) for conducting gas out of the crucible volume (116). The method according to any one of claims 14 to 28, characterized in that.

30. A growth guide (231) is disposed inside the crucible housing (110). The growth guide (231) forms a growth-guide-gas-path-section-boundary (232) for guiding the gas flow into the direction of the seed holder unit (122). The growth guide (231) and the seed holder unit (122) form a gas flow passage (236). Characterized in that, and Establishing a gas flow through the crucible volume (116) by conducting at least a carrier gas into the crucible volume (116) through the crucible gas inlet tube (172) and conducting at least the carrier gas out of the crucible volume (116) through the crucible gas outlet tube (174). Establishing a defined gas flow rate through the gas flow passage by controlling the gas flow into the crucible volume (116) through the crucible gas inlet tube (172), and / or Establishing the defined gas flow rate through the gas flow passage by controlling the gas flow out of the crucible volume (116) through the crucible gas outlet tube (174), wherein The defined gas flow rate is between 1 cm / s and 10 cm / s, preferably between 2 cm / s and 6 cm / s. The step of establishing. The method according to any one of claims 14 to 29, characterized by the above.

31. The receiving space (118) is positioned between the crucible gas inlet tube (172) and the seed holder unit (122). Characterized in that, and Conducting a gas flow around and / or through the receiving space (118). The method according to any one of claims 14 to 30, characterized by the above.

32. At least Si 2 C sublimation vapor, SiC 2 A filter unit (130) for taking in the sublimation vapor and the Si sublimation vapor is disposed inside the crucible volume (116) between the seed holder unit (122) and the crucible gas outlet tube (174). The filter unit (130) forms a filter-unit-gas-flow-path (147) from the filter input surface (140) to the filter output surface (142), and the filter gas flow path is part of the gas flow path between the crucible gas inlet tube (172) and the crucible gas outlet tube (174). The filter unit (130) preferably has a height S1, and the filter-unit-gas-flow-path (147) through the filter unit (130) preferably has a length S2, and S2 is at least twice as long, particularly 10 times as long, as compared to S1. characterized in that, and guiding the gas from the gas flow passage to the filter input surface (140), from the filter input surface (140) through the filter unit (130) to the filter output surface (142), and from the filter output surface to the crucible gas outlet tube (174). The method according to any one of claims 14 to 31, characterized by the above.

33. A pressure unit (132) is provided for setting a crucible volume pressure (P1) inside the crucible volume (116), and the pressure unit (132) is configured to cause a crucible volume pressure (P1) that is higher than 2666.45 Pa, preferably higher than 5000 Pa, or in the range between 2666.45 Pa and 50000.00 Pa. characterized in that, and generating a crucible volume pressure (P1) inside the crucible volume that is higher than 2666.45 Pa, preferably higher than 5000 Pa, or in the range between 2666.45 Pa and 50000.00 Pa. The method according to any one of claims 14 to 32, characterized by the above.

34. A method for producing at least one SiC crystal (17) according to claim 33, wherein the PVT reactor (100) comprises a crucible gas flow unit (170), the crucible gas flow unit (170) comprises a crucible gas inlet tube (172) for conducting gas into the crucible volume (116), and the crucible gas inlet tube (172) is vertically arranged below the receiving space (118). characterized in that, and conducting gas into the crucible housing through the crucible gas flow unit (170). A method characterized by the above.

35. SiC crystal (17) produced according to claim 33 or claim 34. **Claim 36** The SiC crystal (17) according to claim 35, having each of the impurities of the substances B, Al, P, Ti, V, Fe, Ni that are lower than 1000 ppb (by weight), particularly lower than 500 ppb (by weight). **Claim 37** The SiC crystal (17) according to claim 36, having each of the impurities of the substances B, Al, P, Ti, V, Fe, Ni that are lower than 100 ppb (by weight). **Claim 38** The SiC crystal (17) according to claim 37, having an impurity of the substance Ti that is lower than 10 ppb (by weight). **Claim 39** The SiC crystal (17) according to claim 37, having a total impurity of all of the metals Ti, V, Fe, Ni that is lower than 1000 ppb (by weight), particularly lower than 500 ppb (by weight). **Claim 40** The SiC crystal (17) according to claim 37, claim 38, or claim 39. **Claim 41** A system for the production of SiC, comprising a CVD reactor (850) for the production of a first type of SiC as a PVT source material, a processing chamber (856) at least surrounded by a base plate (862), side wall sections (864a), and an upper wall section (864b), Greater than 400 cm 3 Greater than, preferably greater than 5000 cm 3 Greater than, most preferably greater than 10000 cm 3 A single crystal SiC crystal that forms a monolithic block having a volume greater than that a gas inlet unit (866) for feeding one or more feed media into the reaction space of the processing chamber (856) to generate a source medium, wherein the gas inlet unit (866) is coupled to at least one feed media source (851), the Si and C feed media source (851) provides at least Si and C, particularly SiCl3(CH3), and the carrier gas feed media source (853) provides a carrier gas, particularly H2, or wherein the gas inlet unit (866) is coupled to at least two feed media sources (851, 852), ... provides Si gas according to [.4], the C feed media source (852) provides at least C, particularly natural gas, methane, ethane, propane, butane, and / or acetylene, and the carrier gas media source (853) provides a carrier gas, particularly H2. The gas inlet unit (866) ​ ​ ​ The Si feed medium source (851) provides at least Si. In particular, the Si feed medium source has the general formula SiH 4-y X y (where X = [Cl, F, Br, J] and y = [0 ​ ​ One or more SiC growth substrates (857), particularly three or four or six or eight or sixteen or thirty-two or more than sixty-four, or up to one hundred and twenty-eight or up to two hundred and fifty-six, arranged inside the processing chamber (856) for depositing SiC, each SiC growth substrate (857) comprising a first power connection part (859a) and a second power connection part (859b), the first power connection part (859a) being a first metal electrode (206a) and the second power connection part (859b) being a second metal electrode (206b), each SiC growth substrate (857) being coupled between at least one first metal electrode (206a) and at least one second metal electrode (206b) for heating the outer surface of the SiC growth substrate (857) or the surface of the deposited SiC to a temperature between 1300 °C and 1800 °C, particularly by resistive heating, preferably internal resistive heating, such that the first type of SiC is deposited on the SiC growth substrate, the first type of the deposited SiC from the CVD reactor being used in a PVT reactor (100) for the production of a second type of SiC, the PVT reactor (100) comprising a furnace unit (102), and the furnace unit (102) comprising a furnace housing (108) having an outer surface (242) and an inner surface (240), the one or more SiC growth substrates (857), at least one crucible unit (106), the crucible unit (106) being arranged inside the furnace housing (108), the crucible unit (106) comprising a crucible housing (110), the crucible housing (110) having an outer surface (112) and an inner surface (114) at least partially defining a crucible volume (116), a receiving space (118) for receiving a source material (120) in the form of the first type of SiC from the CVD reactor being arranged or formed inside the crucible volume (116), a seed holder unit (122) for holding a defined seed wafer (18) being arranged inside the crucible volume (116), the seed wafer holder (122) holding the seed wafer (18), the furnace housing inner wall (240) and the crucible housing outer wall (112) defining a furnace volume (104), the at least one crucible unit (106), At least one heating unit (124) for heating the source material (120) in the form of the first type of SiC from the CVD reactor, wherein the receiving space (118) for receiving the source material (120) in the form of the first type of SiC from the CVD reactor is at least partially disposed above the heating unit (124) and below the seed holder unit (122), the at least one heating unit (124), adding the first type of SiC as a source material (120) from the CVD reactor into the receiving space (118), subliming the first type of SiC inside the PVT reactor (100), depositing the sublimed SiC as the second type of SiC onto the seed wafer (18), the CVD reactor (850) comprising at least, A system characterized by comprising.

42. The first metal electrode (206a) and the second metal electrode (206b) are preferably blocked from the reaction space. The system according to claim 41, characterized in that.

43. For implementing the method according to any one of claims 1 to 34, The system according to claim 41 or claim 42, characterized in that.

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