Method and device for producing SiC solid material

Abstract

The present invention aims to provide a low cost supply of silicon carbide (SiC). The invention relates to a method for producing preferably elongated SiC solids, in particular of polymorph 3C. The method according to the invention preferably comprises at least the following steps: introducing at least a first source gas comprising Si inside a processing chamber, introducing at least one second source gas comprising C inside the processing chamber, electrically activating at least one separation element arranged in the processing chamber in order to heat the separation element, and setting a deposition rate higher than 200 μm / h, wherein a pressure in the processing chamber higher than 1 bar is generated by the introduction of the first and / or second source gas, and the face of the deposition element is heated to a temperature in the range between 1300° C. and 1800° C.

Description

[Technical Field]

[0001] The present invention relates to a method for producing 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 technology]

[0002] Power electronics based on silicon carbide (SiC) wafers exhibit improved performance compared to those based on conventional silicon (Si) wafers, primarily due to SiC's wider bandgap, which allows it to operate at higher voltages, temperatures, and frequencies. While interest in high-performance SiC-based power electronics is growing as the global shift to electric vehicles (EVs) gains momentum, 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] Currently, industrial-grade SiC source materials are produced through the commercial Acheson process, which is then further refined by powdering and acid leaching. The Acheson process is still the only known process for producing SiC source materials on an industrial scale. Acid leaching is used to extract trace metals from SiC, but it 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 so that this penetration layer constitutes a sufficient proportion of the total volume of the particles. As a result, powdered SiC particles typically need to have an average particle size of 200-300 microns. At this average particle size, the material can only be refined to about 99.99% or 99.999%, respectively, which are referred to as 4N or 5N purities.

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

[0006] Despite their merely moderate 4N or 5N purity, these acid-leached or sintered SiC materials are expensive and significantly contribute to the overall high cost of the resulting SiC wafers. Moderate purity also contributes to high wafer costs, as impurities cause defects within the crystal, which must be discarded rather than subsequently sliced ​​into wafers. In other words, impurities in the source material contribute to a low crystal yield.

[0007] The presence of trace metals in SiC source materials is considered the primary root cause of crystal defects in single-crystal SiC Boules grown by PVT. Currently, the quality of single-crystal 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 undesirable electrical short circuits in SiC electrical devices (mostly vertical devices) and reduce electrical device yield. Therefore, finding better solutions to prevent crystal defects resulting from source material impurities is essential.

[0008] Furthermore, metallic impurities in SiC wafers manufactured from single-crystal SiC boules interact with subsequent implantation and doping techniques used to manufacture SiC electrical devices, which is thought to potentially lead to device failure and reduce electrical device yield.

[0009] Furthermore, the concentration or bandwidth of impurities, particularly nitrogen, increases within the boule, which may result in wafers with conductivity outside the required range or varying from one side of the wafer to the other, at different heights within the same boule. For semi-insulating SiC wafers for RF applications, very low conductivity is required, and therefore, very low concentrations of trace metals and nitrogen are acceptable within the wafer. For 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 in 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 offer a large initial surface area for sublimation and therefore a high initial sublimation rate. A high sublimation rate can be uneconomical in the event that not all evaporated SiC species are incorporated into the crystal, resulting in parasitic polycrystalline deposits on other parts of the crucible. Worse still, high concentrations of SiC species in front of the crystal growth surface can lead to nucleation in the gas phase and amorphous formation or polycrystalline inclusion within single-crystal boules. Over time, powder source materials tend to sinter with each other, producing single-block material with substantially reduced surface area and therefore tailing the sublimation rate. This spiking and tailing sublimation curve for powder source materials results in overall slow growth with the possibility of defects in the grown crystal. Ultimately, powder source materials yield approximately 1.2 g / cm³ 3 It has a low tap density, which limits the mass of material that can be loaded into the crucible and, therefore, the size of the crystals that can be grown.

[0011] Reference GB1128757 discloses a method for depositing thin coatings of SiC. However, the teachings in GB1128757 do not relate to a method for producing large quantities of SiC as a PVT source material.

[0012] DE1184738(B) discloses a method for producing single-crystalline and polycrystalline forms of silicon carbide crystals 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 silicon chloroform, 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 produced at low cost in large-scale industrial processes. SiC is used in many technical fields, especially in 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] Therefore, an object of the present invention is to provide a low-cost supply of silicon carbide (SiC). In addition to or instead of this, high-purity SiC should be provided. In addition to or instead of this, SiC should be provided very quickly. In addition to or instead of this, SiC should be very efficiently produced. In addition to or instead of this, single-crystal SiC with advantageous properties should be produced. [Means for solving the problem]

[0016] The objectives mentioned above are solved by a SiC generation reactor, particularly for the production of PVT source materials, preferably UPSiC. The SiC generation reactor according to the present invention comprises at least a processing chamber, a gas inlet unit for supplying one or more feed media into the reaction space of the processing chamber to generate a source medium, and one or more SiC growth substrates, particularly more or up to 64 SiC growth substrates, arranged inside the processing chamber for depositing SiC.

[0017] This solution is beneficial because it allows for the industrial-scale production of SiC materials, particularly PVT source materials, using this SiC production reactor.

[0018] In a preferred embodiment of the present invention, each SiC growth substrate comprises a first power connection and a second power connection, the first power connection being a first metal electrode, and the second power connection being a second metal electrode, the first and second metal electrodes preferably isolated from the reaction space inside the processing chamber, and each SiC growth substrate is coupled between at least one first metal electrode and at least one second metal electrode to heat the outer surface of the SiC growth substrate or the surface of the deposited SiC to a temperature between 1300°C and 1800°C, particularly using resistance heating, preferably by internal resistance heating. This embodiment is beneficial because it allows the SiC growth substrate to be heated in a very effective manner.

[0019] Since the flowing current requires inlet and outlet electrodes, these electrodes are preferably arranged in multiple pairs, such as 12, 18, 24, 36, or more. Each SiC growth substrate is preferably attached to each electrode of the electrode pairs, particularly the metal electrodes (first and second metal electrodes), and the substrates are connected by bridges, each made of the same material as the substrate, to complete the electrical circuit at their top. Each SiC growth substrate is preferably attached to the electrodes through intermediate components, each chuck. The chuck preferably has a reducing cross-sectional area extending from the electrode to the deposition substrate so that the current concentrates and 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 is preferably conical in shape. The chuck, deposition substrate, and bridge are preferably made from graphite, or more preferably from high-purity graphite having a total ash content lower than 50,000 ppm, preferably lower than 5,000 ppm, and very preferably lower than 500 ppm. The deposition substrate is also preferably made from SiC. In 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 may preferably be located on the opposite side of the processing chamber and / or provided as part of the bell jar.

[0020] The processing chamber is surrounded by at least 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 be defined that the processing chamber is isolated by the base plate, the side wall section, and the upper wall section, respectively. The base plate also preferably has a plurality of gas inlet ports and one or more gas outlet ports. The gas inlet and outlet ports are positioned to generate an optimal flow of feed gas inside the CVD reactor, the SiC production reactor, and in particular the SiC PVT source material production reactor, respectively, so that unused feed gas is constantly in contact with the deposition surface on the deposition substrate.

[0021] The gas inlet unit is coupled with at least one feed medium source, one of which is a Si and C feed medium source, which provides at least Si and C, in particular SiCl3(CH3), and the transport gas feed medium source provides a transport gas, in particular H2; or the gas inlet unit is coupled with at least two feed medium sources, one of which is a Si feed medium source, which provides at least Si, in particular Si gas conforming to the general formula SiH4-yXy(X=[Cl, F, Br, J] and y=[0..4]), the other of which is a C feed medium source, which provides at least C, in particular natural gas, methane, ethane, propane, butane, and / or acetylene, and the transport gas feed medium source provides a transport gas, in particular H2.

[0022] Alternatively, the first feeding medium may be a Si feeding medium, in particular a Si gas conforming to the general formula SiH4-yXy(X=[Cl, F, Br, J] and y=[0..4]), where the gas inlet unit is coupled with at least one feeding medium source, where the Si and C feeding medium source provides at least Si and C, in particular SiCl3(CH3), and the transport gas feeding medium source provides a transport gas, in particular H2, or the gas inlet unit may be coupled with at least two feeding medium sources, where the Si feeding medium source provides at least Si, in particular S i. The supply medium source provides a first supply medium, the first supply medium being a Si supply medium, in particular a Si gas conforming to the general formula SiH4-yXy(X=[Cl, F, Br, J] and y=[0...4]); the C supply medium source provides at least C, in particular a second supply medium, the second supply medium being a C supply medium, in particular natural gas, methane, ethane, propane, butane, and / or acetylene; and the carrier gas medium source provides a third supply medium, the third supply medium being a carrier gas, in particular H2.

[0023] The natural gas is preferably defined as a gas having multiple components, the most abundant of which is methane, particularly more than 50% (by mass) of methane, preferably more than 70% (by mass) of methane, very preferably more than 90% (by mass) of methane, and most preferably more than 95% (by mass) or more than 99% (by mass) of methane.

[0024] That is, each SiC production reactor, each CVD SiC apparatus, is also preferably equipped with a feed gas unit, each medium supply unit, for supplying feed gas to a gas inlet unit. Each feed gas unit, each medium supply unit ensures that the feed gas is heated to the appropriate temperature and mixed in the appropriate ratio before being pumped into the CVD reactor, each SiC production reactor, in particular the SiC PVT source material production reactor. Each feed gas unit, each medium supply unit begins with pipes and pumps that transport the feed gas from its respective source, in particular the storage tank, to around the CVD reactor, each SiC production reactor, in particular the SiC PVT source material production reactor. Here, preferably the mass flow rate of each feed gas is controlled, preferably by individual mass flow meters connected to the overall processing control unit, so that the appropriate ratios of various feed gases can be achieved. Furthermore, separate feed gases are preferably mixed, particularly in a mixing unit of a medium supply unit, and pumped through a gas inlet unit, particularly its multiple gas inlet ports, into the CVD reactors, each a SiC production reactor, particularly a SiC PVT source material production reactor. Preferably, the feed gas unit, each a medium supply unit, can mix three feed gases, each containing a 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, a feed gas containing both Si and C, such as MTCS, is present, 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, preheaters may be required upstream of the gas inlet unit, particularly in the feed gas unit, each upstream of the medium supply unit, to initially heat these feed liquids so that they become feed gases that mix immediately with the other feed gases.

[0025] Preferably, these gases are mixed so that there is a 1:1 atomic ratio between Si and C. In some cases, it may be more preferable to mix these gases so that there is a different atomic ratio between Si and C. Sometimes, to achieve a higher deposition rate, it is desirable to maintain the deposition surface at the higher end of the deposition temperature range of 1300°C to 1600°C. However, under such conditions, there is a possibility of excess C deposition in the SiC. This excess C deposition can be mitigated by mixing the feed gas so that the Si:C ratio is higher than 1:1, preferably 1:1.1, 1:1.2, or 1:1.3. Conversely, sometimes, to result in slow, stress-free deposition, 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 excess Si deposition in the SiC. This excess Si deposition can be mitigated by mixing the feed gas so that the Si:C ratio is lower than 1:1, preferably 1:0.9, 1:0.8, or 1:0.7.

[0026] A more important consideration regarding the feed gas mixture is the atomic ratio of H to Si and C. Excess H can dilute Si and C, reducing the deposition rate. Similarly, excess H may increase the volume of vent gas flowing out of the CVD reactor, the SiC production reactor, and especially the SiC PVT source material production reactor, respectively, complicating the treatment and recirculation of any of these vent gases. Insufficient H, on the other hand, may delay the chemical chain reaction, leading to 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] In yet another embodiment of the present invention, more than four or up to four, preferably more than six or more than eight or up to these numbers, very preferably more than 16, more than 32, or more than 64 or up to these numbers, most preferably up to 128 or up to 256 SiC growth substrates can be arranged inside a single SiC generation reactor.

[0028] This embodiment is beneficial because it allows for a significant increase in the output of the SiC reactor by adding an additional SiC growth substrate.

[0029] In 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 (mass) of feed medium supply (mass) per minute and a maximum amount (mass) of feed medium supply (mass) per minute, the minimum amount (mass) of feed medium supply (mass) per minute corresponding to the minimum amount (mass) of Si and C deposited at a given mass growth rate, the given mass growth rate being higher than 0.1 g per hour per cm² of SiC growth surface, and the maximum amount (mass) of feed medium supply (mass) being up to 30% (mass), up to 20% (mass), up to 10% (mass), up to 5% (mass), or up to 3% (mass) higher than 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] In yet another preferred embodiment of the present invention, the control unit is configured to control the amount of current passing 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 it is possible to maintain SiC deposition by setting the required temperature conditions.

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

[0032] In yet another preferred embodiment of the present invention, the control unit is a hardware arrangement configured to modify the amount of current, wherein the modification of the amount of current over a first defined period from the start of the generation process is predetermined. This embodiment is beneficial because the hardware can be adapted to a predetermined process and therefore no additional sensors are required. Preferably, the first period is one hour or longer, or up to 60% of the duration of the generation process, up to 80% of the duration of the generation process, up to 90% of the duration of the generation process, or up to 100% of the duration of the generation process. Preferably, the hardware arrangement is configured to modify the feed medium supply, wherein the modification of the feed medium supply over a second defined period from the start of the generation process is predetermined, wherein the second period is one hour or longer, or up to 60% of the duration of the generation process, up to 80% of the duration of the generation process, up to 90% of the duration of the generation process, or up to 100% of the duration of the generation process.

[0033] In yet another preferred embodiment of the present invention, at least one sensor is provided, which is coupled with a control unit to provide a sensor signal or sensor data to the control unit, which controls the amount of current and the supply medium depending on the sensor signal or sensor data of at least one sensor, and 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, in particular an IR camera, and preferably a plurality of temperature sensors are provided, the number of temperature sensors corresponding to the number of SiC growth substrates, with at least one, in particular two, five, ten, or twenty temperature sensors provided for every ten SiC growth substrates, or at least one, in particular two, five, ten, or twenty temperature sensors provided for every five SiC growth substrates, or at least one, in particular two, five, ten, or twenty temperature sensors provided for every two SiC growth substrates, preferably the temperature sensor outputs a temperature sensor signal or temperature sensor data representing the measured temperature, in particular surface temperature. This embodiment is beneficial because it allows for immediate adjustment of the internal conditions of the SiC production reactor.

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

[0035] In yet another preferred embodiment of the present invention, one or more valves are provided, each configured to act 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 may be part of a gas inlet unit. This embodiment is beneficial because it can control the feed medium flow and / or the aeration gas flow. Accordingly, in yet another preferred embodiment of the present invention, the control unit is configured to heat the surface of the deposited SiC, particularly to a temperature between 1300°C and 1800°C, in order to increase the electroactivation of at least one SiC growth substrate over time.

[0036] In 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 flow of the feed medium and / or the flow of the aeration gas.

[0037] In other words, preferably, the control unit is configured to receive and process temperature sensor signals or temperature sensor data and / or diameter measurement signals or diameter measurement data, and / or to control one or more valves and / or power supply units.

[0038] In 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 in order to deposit SiC at a set deposition rate, particularly at a vertical deposition rate, for longer than 2 hours, especially 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 it allows for the growth of large quantities of SiC.

[0039] In 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 heating above a specified temperature, and / or the side wall section comprises at least one cooling element, in particular a bell jar cooling element, for preventing it from heating above a specified temperature, and / or the top wall section comprises at least one cooling element, in particular a bell jar cooling element, for preventing it from heating above a specified temperature.

[0040] This embodiment is useful because the present invention discloses a SiC CVD apparatus for the mass commercial production of ultra-high purity bulk CVD SiC. The central components within the SiC CVD apparatus are CVD units, each consisting of a CVD reactor, each consisting of a SiC production reactor, and in particular a SiC PVT source material production reactor. Preferably, each CVD reactor, each consisting of a SiC production reactor, and in particular a SiC PVT source material production reactor comprises a cooling element, each consisting of a base plate, and each consisting of a double-walled fluid-cooled, particularly water-cooled or oil-cooled lower housing, and each consisting of a double-walled liquid-cooled upper housing, and each consisting of a bell jar. Preferably, the inner wall of the base plate, and in particular the bell jar, is made of a material having a usage temperature that is suitable for the operating temperature of each CVD reactor, each consisting of a SiC production reactor, and in particular a SiC PVT source material production reactor. In particular, the inner wall of the bell jar can be made of stainless steel. Preferably, this inner wall is coated with a reflective coating, preferably silver or preferably gold, in addition to or instead of this, in order to reflect and return radiant energy, minimize heat loss, and thus minimize electricity costs. Preferably, the bell jar and / or base plate are made of stainless steel that can withstand high temperatures. However, current high-temperature steels with added chromium, nickel, cerium, or yttrium can withstand temperatures up to 1300°C (in air). As an example, steel EN1.4742 (X10CrAlSi18) has a heat resistance of up to 1000°C. In another example, alloy steel EN2.4816 (UNS N06600) can withstand temperatures up to 1250°C and melts above 1370°C, but its tensile strength drops to below 10% of room temperature values ​​at temperatures above 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 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 to provide through-connections to CVD reactors, SiC-producing reactors, and SiC PVT source material-producing reactors, respectively, for resistance heating of the deposited substrate. In yet another preferred embodiment of the present invention, the cooling element is an active cooling element.

[0043] In yet another preferred embodiment of the present invention, the base plate, side wall section, and / or top wall section are provided with a cooling fluid guide unit for guiding a cooling fluid, the cooling fluid guide unit being configured to limit the heating of the base plate, side wall section, and / or top wall section to a temperature lower than 1300°C. This embodiment is beneficial because it can provide a bell jar made of metal, particularly steel. Steel bell jars are beneficial because they can be produced significantly larger than quartz bell jars.

[0044] In yet another preferred embodiment of the present 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 sections, and / or upper wall sections and outputting a temperature signal or temperature data, and a fluid forwarding unit is provided for forwarding the cooling fluid through a fluid guide unit. This embodiment is beneficial because it allows for continuous cooling without loss or contamination of the cooling fluid and / or processing chamber.

[0045] In yet another preferred embodiment of the present invention, the fluid forwarding unit is configured to operate in reliance 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 it can avoid metallic impurities when the bell jar and / or base plate are operated at temperatures below 1000°C, preferably below 800°C, and very preferably below 400°C, or when the bell jar and / or base plate are cooled to temperatures below 1000°C, preferably below 800°C, and very preferably below 400°C.

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

[0047] In yet another preferred embodiment of the present invention, the cooling element is a passive cooling element. This embodiment is advantageous because the passive cooling element does not require constant monitoring.

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

[0049] That is, in 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 a boundary of the reaction space, and the coating is a metallic coating, in particular comprising or composed of gold, silver, aluminum and / or platinum, and / or configured to reflect at least 2%, at least 5%, at least 10%, or at least 20% of the radiant energy emitted during a single production operation onto the coating.

[0050] In 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 heating above a specified temperature, and / or the side wall section comprises at least one active cooling element and one passive cooling element to prevent it from heating above a specified temperature, and / or the top wall section comprises at least one active cooling element and one passive cooling element to prevent it from heating above a specified temperature.

[0051] In yet another preferred embodiment of the present invention, the side wall section and the top wall section are formed by bell jars, preferably the bell jars are movable relative to a base plate. In 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 top 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 larger steel bell jars, resulting in a significant increase in processing chamber volume and therefore a significant increase in potential SiC material. Accordingly, in yet another preferred embodiment of the present invention, preferably a bell jar is provided having a contact area for forming an interface with a base unit, the interface being sealed to prevent leakage of gaseous chemical species, the bell jar comprising a bell jar cooling unit, the bell jar cooling element forming at least one channel, trench, or recess for holding or guiding bell jar coolant, the bell jar cooling element being configured to cool at least one section of the bell jar, preferably the entire bell jar, to a temperature below a specified temperature, or to remove a specified amount of heat per minute during generation operation. Preferably, the bell jar cooling elements and / or base plate cooling elements are controlled by a control unit. In addition to or instead of this, the bell jar cooling elements and / or base cooling elements are coupled together to form a single main cooling unit.

[0052] In yet another preferred embodiment of the present invention, the base unit comprises at least one base cooling element for cooling it, the base cooling element forming at least one channel, trench, or recess for holding or guiding the base coolant. In yet another preferred embodiment of the present invention, the base cooling element is located within at least one area of ​​the first metal electrodes, preferably within the area of ​​at least one second metal electrode, and is configured to cool the base unit, particularly its surface, to a temperature below a specified temperature, or to remove a specified amount of heat per minute from the base unit, or the base cooling element is configured to cool the entire base unit to a temperature below a specified temperature, or to remove a specified amount of heat per minute during full production operation. This embodiment is beneficial because it allows the electrodes to be operated at high currents without damaging the SiC reactor.

[0053] In 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 it allows for the uniform introduction of current into the SiC growth substrate. In yet another preferred embodiment of the present invention, the first graphite chuck and / or the second graphite chuck are mounted on a base unit.

[0054] In yet another preferred embodiment of the present invention, preferably to avoid metal species contamination of the reaction chamber by metal species of the first and second metal electrodes entering the base unit from the first side of the base unit, the first and second metal electrodes are sealed from the reaction chamber and preferably extend inside the base unit to the other side of the base unit opposite to the first side, and the first metal electrode, preferably the second metal electrode, extends 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] In 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 from the second metal electrode as well. This embodiment is beneficial because it can prevent short circuits.

[0056] In yet another preferred embodiment of the present invention, the control unit is configured to control the amount of current passing 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, and is coupled to a power supply unit for supplying the current, the power supply unit is configured to accept power data or power signals 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 medium supply unit for supplying one or more feed media to a gas inlet unit, the medium supply unit is configured to accept medium supply data or medium supply signals 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, and the base cooling element is configured to accept 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, and the bell jar cooling element is configured to accept 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 medium supply unit. This embodiment is beneficial because the control unit can control multiple parameters and therefore can increase output by operating the heating unit, the supply unit and the cooling unit simultaneously.

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

[0058] In yet another preferred embodiment of the present invention, at least one SiC growth substrate, preferably a plurality of SiC growth substrates or all of the SiC growth substrates, is formed in an I-shape, E-shape, or U-shape, and at least one SiC growth substrate, preferably a plurality of SiC growth substrates or all of the SiC growth substrates is 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 of the SiC growth substrates, is formed in an I-shape, E-shape, or U-shape, and at least one SiC growth substrate, preferably a plurality of SiC growth substrates or all of the SiC growth substrates is connected to a second metal electrode through a base unit, particularly a sealing wall member. This embodiment is advantageous in that 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 a base plate.

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

[0060] In yet another preferred embodiment of the present invention, the control unit is configured to control a medium supply unit to supply one or more feeding media into a processing chamber, wherein the one or more feeding 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 it allows for the control and setting of desired material ratios. That is, a control unit is provided for setting up a feeding media supply of one feeding media and a transport gas into a processing chamber, preferably the control unit is configured to control a medium supply unit to supply one feeding media having a defined molar ratio and / or defined atomic ratio into the processing chamber, wherein the feeding media and transport 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 Si=1 and H=2 to 10, preferably In a control unit for setting up a supply of multiple feeding media into a processing chamber, the control unit is configured to control a media supply unit to feed multiple feeding media into the processing chamber in a predetermined molar ratio and / or predetermined atomic ratio, wherein the multiple feeding media have a predetermined molar ratio Si:C of Si=1 and C=0.8 to 1.1, or a predetermined atomic ratio Si:C of Si=1 and C=0.8 to 1.1.

[0061] In yet another preferred embodiment of the present invention, a Si and C supply medium source is coupled to at least one Si and C supply medium orifice of an inlet unit, and a transport gas supply medium source is coupled to at least one transport gas orifice of an inlet unit, preferably the Si and C supply medium orifice and the transport gas orifice are different from each other, or the Si and C supply medium source and the transport gas supply medium source are coupled to at least one common mixing element and / or guide element, particularly a pipe, and the at least one common mixing element and / or guide element is coupled to at least one orifice of an inlet unit.

[0062] In yet another preferred embodiment of the present invention, a Si and C supply device is provided for supplying a Si and C supply medium from a Si and C supply medium source through at least one orifice of an inlet unit into a reaction space, and / or a transport gas supply device is provided for supplying a transport gas supply medium from a transport gas supply medium source through at least one orifice of an inlet unit into a reaction space, and / or a supply medium supply device is provided for introducing a mixture of the Si and C supply medium and the transport gas supply medium into the reaction space from a common mixing element and / or guide element through at least one orifice of an inlet unit.

[0063] In yet another preferred embodiment of the present invention, instead, a Si supply medium source is coupled to at least one Si supply medium source orifice of the inlet unit, a C supply medium source is coupled to at least one C supply medium source orifice of the inlet unit, a transport gas medium source is coupled to at least one transport gas supply medium source orifice of the inlet unit, the Si supply medium source orifice, the C supply medium source orifice, and / or the transport gas supply medium source orifice are different from each other, or the Si supply medium source and the C supply medium source are coupled to at least one common mixing element and / or guide element, in particular a pipe, and the at least one common mixing element and / or guide element is coupled to at least one orifice of the inlet unit, or the Si supply medium The body source and the conveying gas supply medium source are coupled to at least one common mixing element and / or guide element, particularly a pipe, and at least one common mixing element and / or guide element is coupled to at least one orifice of the inlet unit; or the C supply medium source and the conveying gas supply medium source are coupled to at least one common mixing element and / or guide element, particularly a pipe, and at least one common mixing element and / or guide element is coupled to at least one orifice of the inlet unit; or the Si supply medium source, the C supply medium source and the conveying gas supply medium source are coupled to at least one common mixing element and / or guide element, particularly a pipe, and at least one common mixing element and / or guide element is coupled to at least one orifice of the inlet unit.

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

[0065] In yet another preferred embodiment of the present invention, at least one outlet unit or aeration gas outlet for removing gas from the reaction space is provided as part of the bell jar and / or as part of the base unit. This embodiment is beneficial because the used gas can be guided out of the processing chamber, and thus the amounts of Si and C are less affected by the presence of unexhausted aeration gas. In 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] In yet another preferred embodiment of the present invention, a Si feeding medium source is configured to provide a Si feeding medium having a purity of at least 6N, particularly 7N, preferably 8N, or very preferably 9N; a C feeding medium source is configured to provide a C feeding medium having a purity of at least 6N, particularly 7N, preferably 8N, or very preferably 9N; or a Si and C feeding medium source is configured to provide a Si and C feeding medium having a purity of at least 6N, particularly 7N, preferably 8N, or very preferably 9N; and a transport gas feeding medium source is configured to provide a transport gas feeding medium having a purity of at least 6N, particularly 7N, preferably 8N, or very preferably 9N.Therefore, the process involves introducing at least a first feeding medium, particularly a first source gas, comprising Si and having a purity excluding at least 99.99999% (ppm by weight) of substances B, Al, P, Ti, V, Fe, Ni, in particular one of these substances, preferably more, very preferably most, or most preferably all of them, into a processing chamber; and introducing at least a second feeding medium, particularly a second source gas, comprising C and having a purity excluding at least 99.99999% (ppm by weight) of substances B, Al, P, Ti, V, Fe, Ni, in particular one of these substances, preferably more, very preferably most, or most preferably all of them, into a processing chamber; and introducing at least a second feeding medium, particularly a second source gas, comprising C and having a purity excluding at least 99.99999% (ppm by weight) of substances B, Al, P, Ti, V, Fe, Ni, in particular one of these substances, preferably more, non The present invention can be carried out by introducing a conveying gas having a purity that excludes at least 99.99999% (ppm by weight), which is always preferable, mostly, or most preferable, all of the above; or by introducing a feeding medium, particularly a source gas, comprising Si and C, and containing substances B, Al, P, Ti, V, Fe, Ni, in particular one, preferably more, very preferably, mostly, or most preferably, all of the above, with a purity that excludes at least 99.99999% (ppm by weight), into a processing chamber; and by introducing a conveying gas having a purity that excludes at least 99.99999% (ppm by weight), which is particularly, one, preferably more, very preferably, mostly, or most preferably, all of the above. Accordingly, the present invention discloses a CVD reactor for producing SiC source material that is at least 8N or preferably 9N when first produced, and preferably supplied in the form of granules or solids to minimize 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 effective techniques such as distillation. SiC or PVT source material SiC, especially UPSiC, is generally first deposited in the form of long, thick rods, and then deaggregated, in particular cut or pulverized, into shapes or sizes for use in PVT crucibles.Preferably, the grinding equipment is manufactured from a material that does not contaminate SiC, and there may be an additional acid etching step to remove fine particles and ensure surface purity. This embodiment is beneficial because it can produce large, very high-purity particles with favorable sublimation properties. When an etching step is carried out, a small number of atomic layers (thinner than 1 μm compared to 10-50 μm in Si etching) will be removed, particularly 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, the oxide layer can be removed using, for example, an acidic selection acid composed of HCl:HF:H2O2 and / or a different acid mechanism.

[0067] Chemical vapor deposition (CVD) occurs when the SiC growth substrate is heated to the deposition temperature range and the feed gas mixture is introduced into the CVD reactor, specifically the SiC production reactor, and particularly the SiC PVT source material production reactor. When the feed gas mixture comes into contact with the heated deposition substrate, the energy supplied causes a series of forward and reverse chemical reactions, resulting in the deposition of solid SiC onto the deposition substrate. When the feed gas mixture comprises STC and methane, the net reaction can be summarized as follows: SiCl4 + CH4 = SiC + 4HCl

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

[0069] According to yet another preferred embodiment of the present invention, the surface of a base unit defining the boundary of the reaction space and the upper section of a bell jar surface defining the boundary of the reaction space are spaced apart by a first distance, the upper section of the bell jar surface being located at the furthest distance from the base unit surface in the height direction, the first distance being the furthest distance, and one or more SiC growth substrates extending over a second distance in the height direction, the second distance having 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 extending over a second distance in the height direction, the first distance being up to 10%, up to 20%, up to 30%, or up to 50% longer than the second distance. In yet another preferred embodiment of the present invention, the first distance is longer than 100 cm, up to 100 cm, or exactly 100 cm, preferably longer than 130 cm, up to 130 cm, or exactly 130 cm, longer than 150 cm, up to 150 cm, or exactly 150 cm, very preferably longer than 170 cm, up to 170 cm, or exactly 170 cm, longer than 200 cm, up to 200 cm, or exactly 200 cm, longer than 250 cm, up to 250 cm The diameter of the reaction space is longer than 50 cm, longer than 70 cm, longer than 70 cm, longer than 70 cm, longer than 100 cm, longer than 100 cm, longer than 100 cm, preferably longer than 120 cm, longer than 120 cm, or very preferably longer than 150 cm, longer than 150 cm. This embodiment is beneficial because it allows the use of a large SiC growth substrate inside the SiC production reactor, thereby increasing the production efficiency.

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

[0071] In yet another preferred embodiment of the present invention, the bell jar defining the boundary of the reaction space, particularly its surface, and / or the base unit defining the boundary of the reaction space, particularly its surface, is configured to withstand chemical treatment, particularly 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] In yet another preferred embodiment of the present invention, the SiC growth substrate is configured to hold a SiC solid having a mass of more than 1 kg, particularly more than 5 kg or up to 5 kg, preferably more than 50 kg or up to 50 kg, or very preferably more than 200 kg or up to 200 kg, most preferably more than 500 kg or up to 500 kg, and a thickness of at least 1 cm, particularly 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 large quantities of SiC material or PVT source material.

[0073] In yet another preferred embodiment of the present invention, the reaction space volume allows for the production of one SiC solid or the simultaneous production of multiple Si container storage locations, and the SiC solid has a mass of more than 1 kg, particularly more than 5 kg or up to 5 kg, preferably more than 50 kg or up to 50 kg, or very preferably more than 200 kg or up to 200 kg, most preferably more than 500 kg or up to 500 kg, and a depth of at least 1 cm, particularly 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, very preferably greater than 20 cm or up to 20 cm, or most preferably 5 The SiC solids have a thickness greater than 0 cm or up to 50 cm, or more or all of the SiC solids have a mass greater than 1 kg, particularly greater than 5 kg or up to 5 kg, preferably greater than 50 kg or up to 50 kg, 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, particularly 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, very preferably greater than 20 cm or up to 20 cm, or most preferably greater than 50 cm or up to 50 cm. This embodiment is beneficial because it can produce large quantities of SiC material or PVT source material.

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

[0075] In 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 at least indirectly coupled to one or at least one second metal electrode through a second end, wherein the distance between the first end of the SiC growth substrate and the first metal electrode is less than 20% of the length of the SiC growth substrate, preferably less than 10% of the length of the SiC growth substrate, and most preferably less than 5% of the length of the SiC growth substrate. Preferably, the length of the SiC growth substrate is the physical extension of the SiC growth substrate in the direction of current flow at its center.

[0076] In each CVD reactor, the total deposit area inside the SiC production reactor, particularly the SiC PVT source material production reactor, will grow over time as more deposits accumulate on the SiC growth substrate and the circumference of the deposits grows. The SiC growth substrate can preferably be a slender rod with a diameter of at least 1.0 cm and a height of, for example, up to 250 cm. When this SiC growth substrate reaches a diameter of, for example, 10 cm due to the accumulation of SiC, it will have a total area that is proportionally 10 times larger than at the start. Therefore, it is also necessary to increase the total feed gas mixture flow rate to accommodate this increase in volume deposition rate during the deposition process.

[0077] A SiC growing substrate can accumulate a layer so that it can reach a total diameter of, for example, 20 cm. At this point, the circumference is approximately 60 cm, and if the vertical deposition rate is 1 mm per hour, the volume deposition rate is 6 cm³ per hour per 1 cm of rod height. However, the average volume deposition rate throughout the run is actually closer 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 can be increased by using deposition substrates, each SiC growth substrate, that have a large starting area. A deposition substrate in the form of a thin 10 cm wide ribbon has a starting area of ​​20 cm per cm height, compared to a slender rod with a diameter of 1 cm having an area of ​​approximately 3 cm per cm height, substantially and dramatically increases the average volume deposition rate, making it possible to deposit the same amount of SiC in a considerably shorter run time. Consequently, CVD reactors, each SiC production reactor, and especially SiC PVT source material production reactors, can carry out more processes in a year. As a result, fewer CVD reactors, each SiC production reactor, and especially SiC PVT source material production reactors are required to produce the same total tonnage of SiC. Therefore, using deposition substrates with a large starting area is a preferred embodiment of the present invention.

[0079] In 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 longitudinal direction of the SiC growth substrate, or, if there are multiple SiC growth substrates, each 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 longitudinal direction of each SiC growth substrate. Preferably, the SiC growth substrate has an average perimeter of up to 25 cm, preferably up to 50 cm, or very preferably up to 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 produced at a considerably faster rate.

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

[0081] In yet another preferred embodiment of the present invention, the shape of the cross-section orthogonal to or perpendicular to the longitudinal 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.

[0082] In 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 higher ratio (U / A) allows for higher volume growth.

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

[0084] In 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 first rod ends coupled to the same first metal electrode, and all second rod ends coupled to the same second metal electrode, or 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 first rod ends coupled to the same first metal electrode of each SiC growth substrate, and all second rod ends coupled to the same second metal electrode of each SiC growth substrate. In yet another preferred embodiment of the present invention, the rods of the SiC growth substrate are arranged in contact with each other or at a distance from each other. In yet another preferred embodiment of the present invention, the SiC growth substrate comprises 3 or more rods, or each of the plurality of SiC growth substrates comprises 3 or more rods. This embodiment is advantageous because the rod used can be a standard component, and therefore it is less expensive compared to, for example, graphite ribbon.

[0085] In 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 a first metal electrode of the respective SiC growth substrate and the second metal rod end being coupled to a second metal electrode of the respective SiC growth substrate. This embodiment is advantageous because the metal rods are inexpensive and can be supplied in multiple shapes, particularly in high ratios (U / A).

[0086] In yet another preferred embodiment of the present invention, the metal rod is provided with a coating, which is preferably made of SiC, and / or preferably the coating has a thickness greater than 2 μm, preferably greater than 100 μm, or very preferably greater than 500 μm, or 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 because fewer metal particles remain on the SiC solid after the SiC solid is removed from the metal rod. Deposition substrates made of metal or alloy, respectively, and SiC growth substrates are also preferred due to their suitability for multiple uses in subsequent SiC production processes. Here, it is conceivable that one or more coatings (preferably thinner than 1000 μm, very preferably thinner than 500 μm, and most preferably thinner than 100 μm, such as a carbon layer) can be used to prevent the metal of the substrate from penetrating into the SiC material during deposition.

[0087] During the deposition process, the feed gas mixture is preferably continuously pumped into the CVD reactors, specifically the SiC production reactors, and in particular the SiC PVT source material production reactors, while the vent gas is preferably continuously flowing out of the reactors. Due to the deposition reaction, the composition of the vent gas differs considerably from that of the feed gas mixture. Firstly, a large amount of HCl is generated, as shown by the net deposition reaction, and is present in the vent gas along with the unreacted feed gas. Secondly, side reactions occur that lead to the formation of other Si-containing molecules. For example, if the feed gas mixture contains STC, some TCS will be formed as a side reaction in the CVD reactors, specifically the SiC production reactors, and in particular the SiC PVT source material production reactors, and will flow out into the vent gas.

[0088] In small-scale SiC production, conversion efficiency is relatively low, and even when a large molar ratio of Si-containing gas to C-containing gas is used compared to SiC deposited with a high molar ratio of H, recirculating the vent gas may not be advantageous. Therefore, in one embodiment of the present invention, the vent gas is first sent to a scrubber, where it is contacted with water to remove all Si-containing compounds and HCl. Next, the vent 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. Meanwhile, the scrubbing solution is sent to a recycling company for further processing, utilization, and disposal.

[0089] In yet another preferred embodiment of the present invention, a gas outlet unit and a vent gas recirculation unit are provided for extracting vent gas, 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, a first storage element and / or conduction element for storing or conducting the first fluid being part of or coupled to the separation unit, and a 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 source material costs. Preferably, the separation unit is operated at a pressure higher than 5 bar and a temperature lower than -30°C. Therefore, preferably, the aeration gas is fed into a separation unit which can be a low-temperature distillation column, where the Si-containing compound condenses from gaseous to liquid form and flows down the column out from the bottom, while the remaining H gas, HCl gas, and methane gas flow up the column out from the top. The liquid is a first fluid, preferably comprising mainly HCl and chlorosilane, with low percentages of H2 gas and C gas. The gas preferably comprises mainly H2 and C gas, with low percentages of HCl and chlorosilane.

[0090] In yet another preferred embodiment of the present invention, the aeration gas recirculation unit comprises yet another separation unit for separating the first fluid into at least two parts, namely a chlorosilane mixture and a mixture of HCl, H2 and at least one C-containing molecule, preferably at least three parts, namely a chlorosilane mixture and a mixture of HCl, H2 and at least one C-containing molecule, wherein 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 a SiC production reactor toward the production of a 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] In yet another preferred embodiment of the present invention, yet another separation unit is coupled with a storage element and / or conduction element for a chlorosilane mixture, a storage element and / or conduction element for HCl, and storage elements and / or conduction elements for H2 and C.

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

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

[0094] Accordingly, according to the present invention, SiC source material 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 recirculated back from the vent gas of the first SiC raw material production reactor. This recirculation is achieved by measuring the atomic ratio of H-pair C in the mixture and supplying a hydrogen-carbon-hydrogen gas with the mixture to the CVD reactor in an appropriate composition ratio so that the overall H-pair C molar ratio of hydrogen to carbon in the carbon-containing gas is within the required range. Under given conditions in both the CVD reaction and subsequent low-temperature distillation, both carbons exist as methane. In the CVD reaction, any by-products derived from methane 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 online measurements (PAT, process analysis techniques) such as, for example, flame ionization detection, infrared spectroscopy of either type (e.g., FTIR or NIR), or cavity ring-down spectroscopy (which has the most sensitive detection limits), or by any other in-line or online analytical method that yields 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. Preferably, losses are compensated to maintain the molar ratio of the original feed gas mixture. This embodiment is beneficial because the purity of Si, C, and H2 recirculated due to the recirculation of the feed gas is further increased, and therefore the purity of the SiC product is even better.

[0095] In yet another preferred embodiment of the present invention, a Si mass flux measuring unit for measuring the amount of Si in a chlorosilane 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, providing yet another Si feed medium. In yet another preferred embodiment of the present invention, a storage element and / or conduction element of the chlorosilane mixture forms a section of the chlorosilane mixture mass flux path for conducting the chlorosilane mixture into yet another processing chamber of yet another SiC production reactor. This embodiment is beneficial because it can be precisely 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, if the feed medium from the recirculation unit is insufficient, a feed medium from the feed source can be added to the feed medium from the recirculation unit.

[0096] In yet another preferred embodiment of the present invention, H2 and C storage elements and / or conduction elements form a section of the H2 and C mass flux pathway for conducting H2 and at least one C-containing molecule into a processing chamber. Furthermore, HCl may be present. In yet another preferred embodiment of the present invention, a C mass flux measuring unit for measuring the amount of C in a mixture of H2 and at least one C-containing molecule is provided as yet another C feeding medium source, preferably as part of the H2 and C mass flux pathway before the processing chamber, particularly before the mixing device, providing yet another C feeding medium. In yet another preferred embodiment of the present invention, H2 and C storage elements and / or conduction elements form a section of the H2 and C mass flux pathway for conducting H2 and at least one C-containing molecule into yet another processing chamber of yet another SiC production reactor. In yet another preferred embodiment of the present invention, a second storage element and / or conduction element forms a section of an H2 and C mass flux path for conducting a second fluid comprising H2 and at least one C-containing molecule into a processing chamber, and the second storage element and / or conduction element and the H2 and C storage element and / or conduction element are preferably fluid-coupled. In yet another preferred embodiment of the present invention, a second storage element and / or conduction element forms yet another section of an H2 and C mass flux path for conducting a second fluid comprising H2 and at least one C-containing molecule into a processing chamber. In yet another preferred embodiment of the present invention, yet another C mass flux measuring unit for measuring the amount of C in the second fluid is provided as part of yet another H2 and C mass flux path before the processing chamber, particularly before 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 recirculated, and therefore the overall efficiency is increased.

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

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

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

[0100] This embodiment is advantageous 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 further from any heavy contaminants such as trace metals, by conventional distillation methods and distillation apparatus. 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 proceeds towards the bottom of the column, and nitrogen is gaseous and proceeds towards the top of the column.

[0101] In 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 a SiC production reactor, and the multiple feed media comprises a first medium, a second medium, and a third medium, and further Si feed media and / or further C feed media are supplied into the processing chamber through a gas inlet unit. Preferably, the further Si feed media consists of a mixture of chlorosilanes in an amount 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, another C-supplying medium comprises at least one C-containing molecule, H2, HCl, and a chlorosilane mixture, comprising 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, comprising 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, comprising more than 5% (by mass), preferably more than 10% (by mass) or very preferably more than 25% (by mass) of H2, and further comprising more than 0.01% (by mass), preferably more than 1% (by mass), very preferably between 0.001% (by mass) and 10% (by mass) of a chlorosilane mixture.

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

[0103] The purpose mentioned above is also at least the following stages: The process involves providing a source medium inside a processing chamber, which is at least surrounded by a base plate, a side wall section, and an upper wall section, and preferably a processing chamber of a SiC production reactor according to the present invention; electrically activating at least one SiC growth substrate, preferably a plurality of SiC growth substrates, placed in the processing chamber and heating them to a temperature in the range of 1300°C to 2000°C; and setting a deposition rate particularly higher than 200 μm / h, preferably higher than 300 μm / h, and very preferably higher than 500 μm / h, in order to extract Si and C from the source medium and deposit the extracted Si and C as SiC onto the SiC growth substrate, thereby forming a SiC solid preferably composed of polycrystalline SiC. This is solved by a PVT source material production method for producing PVT source materials, particularly those composed of polymorphic 3C SiC, which are equipped with [specific features / features].

[0104] In yet another preferred embodiment of the present invention, each SiC growth substrate comprises a first power connection and a second power connection, the first power connection being a first metal electrode and the second power connection being a second metal electrode, and preferably the first and second metal electrodes are isolated from the reaction space of the processing chamber.

[0105] Preferably, the PVT source material production method includes a step of preventing the base plate, side wall sections, and / or top wall sections from heating to a predetermined temperature, particularly above 1300°C.

[0106] This method is beneficial because it can produce ultra-high purity bulk CVD SiC. In this invention, bulk CVD SiC refers to CVD SiC in an independent form, not a coating on another material. Therefore, "bulk" CVD SiC does not mean that it exhibits the maximum density compared to other forms of SiC, such as sintered SiC. This invention produces SiC, in particular polycrystalline SiC, especially the 3C crystalline polymorph.

[0107] It should be noted that the PVT source material production method can be understood as an alternative to a SiC production method, particularly a SiC production method carried out by a CVD reactor.

[0108] The object mentioned above is addressed by the present invention, in particular by a method for producing polymorphic 3C, preferably elongated, SiC solids, according to claim 1. Preferably, the method according to the present invention comprises at least the following steps: Steps include: 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 deposit element placed in the processing chamber for heating; 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 and / or second source gases, and heating the surface of the deposit element to a temperature in the range of 1300°C to 1700°C. It is equipped with.

[0109] This solution is beneficial because it allows for extremely rapid growth of deposited elements due to the selected parameters. This rapid growth has a significant impact on the overall cost, making it possible to produce SiC at a significantly lower cost compared to conventional techniques.

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

[0111] This embodiment is advantageous because it can generate a favorable gas flow within the processing chamber using a transport gas.

[0112] The object mentioned above is addressed by the present invention, in particular by a method for producing polymorphic 3C, preferably elongated, SiC solids, according to claim 3. Preferably, the present method according to the present invention comprises the following steps: The steps include: 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 transport gas comprising H into the processing chamber; charging at least one deposition element placed in the processing chamber for heating; 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 transport gas, and heating the surface of the deposition element to a temperature between 1300°C and 1700°C or in the range between 1300°C and 1700°C. It is equipped with.

[0113] This solution is beneficial because it allows for extremely rapid growth of deposited elements due to the selected parameters. This rapid growth has a significant impact on the overall cost, making it possible to produce SiC at a significantly lower cost compared to conventional techniques.

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

[0115] Further preferred embodiments of the present invention are the subject matter of the following descriptive portion and / or dependent claims.

[0116] In yet another preferred embodiment of the present invention, the introduction of a first source gas and / or a 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, and especially 6 bar.

[0117] This embodiment is advantageous because increasing pressure provides more starting material to be placed on the deposition element in the form of SiC or to grow the deposition element through it.

[0118] In another preferred embodiment of the present invention, the surface of the deposition element is heated to a temperature in the range of 1450°C to 1700°C, particularly in the range of 1500°C to 1600°C or 1490°C to 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 is recognized that at excessively low temperatures, the proportion of Si deposited on the deposition element increases, and at excessively high temperatures, the proportion of C deposited on the deposition element increases. However, within the temperature range mentioned, the SiC is at its purest.

[0120] In another preferred embodiment of the present invention, a first source gas is introduced into the processing chamber through a first supply means, a second source gas is introduced into the processing chamber through a second supply means, or the first and second source gases are mixed before being introduced into the processing chamber and then introduced into the processing chamber through a supply means, and the source gases are mixed in a molar ratio of Si=1 and C=0.8 to 1.1 Si:C and / or an atomic ratio of Si=1 and C=0.8 to 1.1 Si:C and then introduced into the processing chamber. These ratios are advantageous because they allow the Si:C=1:1 ratio of the SiC solid material to be adjusted very precisely 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] In another preferred embodiment of the present invention, the transport gas comprises H, and the source gas and transport gas exist in a molar ratio Si:C:H of Si=1, C=0.8 to 1.1, and H=2 to 10, particularly a molar ratio Si:C:H of Si=1, C=0.9 to 1, and H=3 to 5, and / or atomic ratio Si:C:H of Si=1, C=0.8 to 1.1, and H=2 to 10, particularly an atomic ratio Si:C:H of Si=1, C=0.9 to 1, and H=3 to 5, and are introduced into the processing chamber.

[0123] Preferably, the atomic ratios or molar ratios of H2:SiCl4:CH4=5:1:1, or alternatively, H2:SiCl4:CH4=6:1:1, H2:SiCl4:CH4=7:1:1, H2:SiCl4:CH4=8:1:1, H2:SiCl4:CH4=9:1:1, or H2:SiCl4:CH4=10:1:1 exist in the deposition.

[0124] Therefore, the atomic ratio or molar ratio between H2, SiCl4, and CH4 in the 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, and this can also be applied when the flow rate is changed. Particularly preferably, the total pressure or the pressure in the processing chamber is also kept constant during deposition.

[0126] This embodiment provides a gas composition that allows very high-purity SiC to be deposited on the deposition element at very high speed, and is advantageous because favorable gas transport is achieved within the processing chamber.

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

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

[0129] In another preferred embodiment of the present invention, the first source gas is SiCl4, SiHCl3, or SiCl4, and 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 the supply of Si and C that are optimal for deposition.

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

[0132] In other words, preferably, impurities in amounts less than 1 ppm by weight, particularly substances B, Al, P, Ti, V, Fe, and Ni, are components of one or more expanding gases and / or transport gases, or impurities in amounts less than 0.1 ppm by weight, particularly substances B, Al, P, Ti, V, Fe, and Ni, are components of one or more expanding gases and / or transport gases, or inclusions in amounts less than 0.01 ppm by weight, particularly substances B, Al, P, Ti, V, Fe, and Ni, are components of one or more expanding gases and / or transport gases.

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

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

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

[0136] In 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, a control device modifies, in particular increases, the electrical load of the isolation element as a function of the temperature signal and / or temperature data.

[0137] This embodiment is advantageous because it can compensate for undesirable effects resulting from growth. In particular, as a result of the formation or deposition of SiC, the mass of the deposited element increases, and consequently, the temperature of the deposited element changes, especially decreases, under the same electrical load. This temperature decrease is thought to result in an increase in Si content. The temperature change can be compensated for or reversed by modifying, especially increasing, the applied electrical load, especially increasing the current.

[0138] In yet another preferred embodiment of the present invention, the temperature measuring device performs a temperature measurement for a period of time shorter than 5 minutes, particularly shorter than 3 minutes, shorter than 2 minutes, shorter than 1 minute, or shorter than 30 seconds, and outputs a temperature signal and / or temperature data. Preferably, a target temperature or target temperature range is defined. Preferably, the control device controls the increase in electrical application as soon as the temperature signal and / or temperature data represents a surface temperature lower than a defined threshold temperature, so that the threshold temperature is a temperature or lower limit of a set temperature range that is a predetermined value lower than the set temperature. 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 temperature changes with very high precision. As a result, very high purity can be obtained. This very high purity preferably allows the current amount or current intensity to 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. This very high purity preferably allows the current amount or current intensity to 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] In yet another preferred embodiment of the present invention, a larger amount of source gas, particularly a first source gas and / or a second source gas, is introduced into the processing chamber continuously or stepwise per unit time, in a particularly defined ratio. Preferably, the larger amount of source gas, particularly the first source gas and / or the second source gas, is introduced into the processing chamber as a function of time and / or as a function of electrical load.

[0141] This embodiment is advantageous because the mass of the source gas can be adapted to the increase in the surface area of ​​the deposited elements. As a result, it is preferable to maintain an optimal amount (mass) of Si and C in the processing chamber throughout the production process.

[0142] The objectives mentioned above are also particularly aimed at producing polymorphic 3C, preferably elongated, SiC solids, which are particularly addressed by a device for carrying out the above method according to claim 12. Preferably, the device according to the present 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; a first supply means and / or a second supply means for introducing the first source gas and / or the second source gas into the processing chamber at a pressure greater than 1 bar; a temperature measuring means for measuring the surface temperature of the deposition element; and a control means for setting a deposition rate greater than 200 μm / h. Preferably, the control device can adjust the electrical application to a separation element that is adjustable from 1300°C to 1700°C to generate a surface temperature.

[0143] The objectives mentioned above are also aimed at producing polymorphic 3C, preferably elongated, SiC solids, and are particularly addressed by a device for carrying out the above-described method according to claim 13. Preferably, the device according to the present invention comprises at least one processing chamber for receiving a chargeable deposition element; at least one source gas comprising Si and C, particularly SiCl3(CH3) and preferably H; a first supply means and / or a second supply means for introducing the source gas and / or the transport gas into the processing chamber at a pressure higher than 1 bar; a temperature measuring means for measuring the surface temperature of the deposition element; and a 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 separation element that is adjustable from 1300°C to 1700°C to bring about a surface temperature.

[0144] Particularly preferably, in all embodiments, the separation element described herein is preferably composed of graphite, carbon, or SiC, or is preferably an elongated body having graphite or carbon and / or SiC. The separation element may be manufactured from graphite or carbon and a SiC plate having a thickness of particularly less than 5 mm, less than 2 mm, less than 1 mm, or less than 0.1 mm may be placed on or covered therewith. Alternatively, the SiC layer may be grown on graphite. The SiC plate and / or SiC growth layer may be, for example, single crystal or polycrystalline. Preferably, the deposited element is coupled to the first electrical contact within the region of the first end of its longitudinal extension, particularly closer to the first end of its longitudinal extension than to the second end of its longitudinal extension. In addition, preferably, the deposited element is coupled to the first electrical contact within the region of the second end of its longitudinal extension, particularly closer to the second end of its longitudinal extension than to the first end of its longitudinal extension. Preferably, in order to heat the isolation element, current is introduced into the isolation element through one of these two contacts and discharged from the isolation element through the other contact.

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

[0146] Preferably, the SiC solid material or deposited element (after the completion of the deposition process) has a diameter of at least or exactly 4 inches, at least or exactly or up to 6 inches, at least or exactly or up to 8 inches, or at least or exactly or up to 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 at least 99.9999% (ppm by weight) of substance B, Al, P, Ti, V, Fe, and Ni. Therefore, preferably, substance B, Al, P, Ti, V, Fe, and Ni are present in amounts less than 1 ppm by weight, less than 0.1 ppm by weight, or less than 0.01 ppm by weight.

[0148] Particularly preferred is component B in an amount less than 1 ppm by weight of the SiC material. Particularly preferred is component Al in an amount less than 1 ppm by weight of the SiC material. Particularly preferred is component P in an amount less than 1 ppm by weight of the SiC material. Particularly preferred is component Ti in an amount less than 1 ppm by weight of the SiC material. Particularly preferred is component V in an amount less than 1 ppm by weight of the SiC material. Particularly preferred is component Fe in an amount less than 1 ppm by weight of the SiC material. Particularly preferred is component Ni in an amount less than 1 ppm by weight of the SiC material.

[0149] Particularly preferred is component B in an amount less than 1 ppm by weight of the SiC material. Particularly preferred is component Al in an amount less than 1 ppm by weight of the SiC material. Particularly preferred is component P in an amount less than 1 ppm by weight of the SiC material. Particularly preferred is component Ti in an amount less than 1 ppm by weight of the SiC material. Particularly preferred is component V in an amount less than 1 ppm by weight of the SiC material. Particularly preferred is component Fe in an amount less than 1 ppm by weight of the SiC material. Particularly preferred is component Ni in an amount less than 1 ppm by weight of the SiC material.

[0150] Particularly preferred is component B in amounts less than 0.1 ppm by weight of the SiC material. Particularly preferred is component Al in amounts less than 0.1 ppm by weight of the SiC material. Particularly preferred is component P in amounts less than 0.1 ppm by weight of the SiC material composition. Particularly preferred is component Ti in amounts less than 0.1 ppm by weight of the SiC material. Particularly preferred is component V in amounts less than 0.1 ppm by weight of the SiC material composition. Particularly preferred is component Fe in amounts less than 0.1 ppm by weight of the SiC material. Particularly preferred is component Ni in amounts less than 0.1 ppm by weight of the SiC material.

[0151] Particularly preferred is component B in amounts less than 0.01 ppm by weight of the SiC material. Particularly preferred is component Al in amounts less than 0.01 ppm by weight of the SiC material. Particularly preferred is component P in amounts less than 0.01 ppm by weight of the SiC material composition. Particularly preferred is component Ti in amounts less than 0.01 ppm by weight of the SiC material. Particularly preferred is component V in amounts less than 0.01 ppm by weight of the SiC material composition. Particularly preferred is component Fe in amounts less than 0.01 ppm by weight of the SiC material. Particularly preferred is component Ni in amounts less than 0.01 ppm by weight of the SiC material composition.

[0152] In the context of this patent specification, ppm is preferably understood to mean ppm by weight.

[0153] In addition, nitrogen is incorporated from the SiC source material into the PVT SiC crystal, altering its electrical properties, so a low nitrogen (N) content is preferable. In some cases, the SiC crystal is doped with nitrogen during the PVT process, and this doping is preferably carried out by adding 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 resolved by using a source gas of a particularly specified quality according to the method described herein. Thus, the resulting SiC source material has an elemental N content of less than 30,000 ppba (atoms), which corresponds to less than 10.5 ppm (weight) when measured by elemental analysis.

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

[0156] Particularly preferred is a composition of SiC material where substance N is lower than 2000 ppb by weight.

[0157] Particularly preferred is a composition of SiC material where substance N is less than 1000 ppb by weight.

[0158] Particularly preferred is a composition of SiC material where substance N is lower than 500 ppb by weight.

[0159] In addition, the present invention, as 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] Table 1

[0161] Table 1 above shows the impurity levels of one SiC sample produced by the present 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 favorable according to the purity of the SiC of the present invention.

[0162] [Table 2] Table 2

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

[0164] Furthermore, the objectives mentioned above are achieved by using the SiC solid-state material according to claim 14 in a PVT reactor for producing single-crystal SiC.

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

[0166] This solution is advantageous because high-purity SiC solid-state material provides a very favorable starting material for the PVT process. On the other hand, this material is advantageous because it can be used as a solid-state block. This solid block can then be broken into fragments having a specified 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 greater than 2 cm³ or 5 cm³.

[0167] Alternatively, the solid block can be divided into several, preferably at least, substantially uniform pieces, particularly perpendicular to the longitudinal axis or elongation direction of the solid block, in particular by splitting or sawing. Preferably, the divided pieces are thin flakes having a minimum thickness of 0.5 cm, 1 cm, 3 cm, or 5 cm, particularly up to a maximum thickness of 20 cm, 30 cm, or 50 cm. In both cases (crushing or splitting), a solid with a minimum size can be provided. The supply of solids of these sizes allows for a larger and more uniform temperature distribution within the SiC solid material (starting material) when heating, compared to ultrafine starting material for the PVT process, resulting in larger and more uniform evaporation of the starting material. Furthermore, in the case of ultrafine starting material, relative movement between individual material fragments occurs due to the increasing vapor and material extraction in individual material fragments, resulting in turbulence that adversely affects the crystal growth process. These drawbacks can be eliminated by using larger fragments or pieces.

[0168] This solution is further advantageous because the total area is significantly smaller than when ultrafine material is used due to larger fragments or pieces. Therefore, the total area is easily determined and used as a parameter for adjustment during the PVT process.

[0169] This solution is further advantageous because, due to the low density of the SiC solid-state material produced by the present invention, the transition of the boundary layer forming the surface of the solid-state material can occur more rapidly.

[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 features as described below. Such a new reactor is preferably a reactor or PVT reactor for crystal growth, particularly for SiC crystal growth. The reactor or furnace device further comprises at least one, two or more, or exactly one crucible or crucible unit, the at least one crucible or crucible unit being placed in the furnace volume. The crucible or crucible unit comprises, has, or forms a crucible housing having an outer surface and an inner surface that at least partially defines the crucible volume. A receiving space for receiving starting material is arranged or formed in the crucible volume. Preferably, a seed holder unit for receiving a defined seed wafer 18 is also provided, particularly placed in the crucible volume, or such a seed holder unit can be placed in the crucible volume. The reactor or oven device further includes, in particular, at least one heating unit for heating the starting material and / or the crucible housing of the crucible unit. Where a seed holder unit is provided, a receiving space for receiving the starting material is preferably located 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 eliminate at least one of the purposes mentioned above, or some or all of these purposes.

[0172] Further preferred embodiments are the subject matter of yet another part of the specification and / or dependent claims.

[0173] In a preferred embodiment of the present invention, the furnace apparatus further includes at least one leak prevention device for preventing the leakage of silicon gas from inside the crucible or crucible unit into a portion of the furnace volume surrounding the crucible unit during operation. This design is advantageous because it eliminates the drawbacks of easily leaking Si vapor.

[0174] In another preferred embodiment of the present invention, a leak inhibitor is selected from a group of leak inhibitors. Preferably, the group of leak inhibitors comprises 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 volumetric 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 a second pressure inside the furnace but outside the crucible unit that is higher than the first pressure, and (d) a seal disposed between the housing portions of the crucible unit. This embodiment is advantageous because it provides several features that result in improvements to the furnace device. Such an oven device may be provided with one or more or all of the features of the above group of leak inhibitors. Thus, the present invention further provides solutions for different needs, particularly for different products, especially crystals having different properties.

[0175] In another preferred embodiment of the present invention, the leak inhibitor reduces the leakage of sublimation vapors, particularly Si vapors, from the crucible volume through the crucible housing into the furnace volume by at least 50% (mass), at least 80% (mass), at least 90% (mass), 99% (mass), or at least 99.9% (mass). This embodiment is advantageous because components such as the crucible housing and heating unit, which result in a significantly reduced amount of easily leakable Si vapors, can be reused multiple times, particularly more than 10 times, or more than 20 times, or more than 50 times, or more than 100 times. Thus, the crucible unit, crucible housing, each section of the crucible unit, or each section of the crucible housing has a permeability of less than 10⁻² cm² / s, or less than 10⁻⁵ cm² / s, or less than 10⁻¹⁰ cm² / s, particularly with respect to Si vapors.

[0176] In yet another preferred embodiment of the present invention, to withstand temperatures higher than 2000°C, particularly at least or up to 3000°C, or at least up to 3000°C, or at least up to 3500°C, or at least up to 3500°C, or at least up to 4000°C, the crucible housing comprises carbon, particularly 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 all of the crucible housing is composed of carbon, particularly the crucible housing comprises or is composed of at least 90% (by mass) 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 its external components. In addition to or instead thereof, the crucible unit, crucible housing structure, or crucible housing comprises glassy carbon-coated graphite, solid glassy carbon, pyrocarbon-coated graphite, tantalum carbide-coated graphite, and / or solid tantalum carbide.

[0177] In another preferred embodiment of the present invention, the leakage prevention means is a cover element for covering the surfaces of the housing, particularly the inner and / or outer surfaces, or for covering multiple surface portions of the housing, particularly multiple surface portions of the inner surface of the housing and / or multiple 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, both of these steps (generation step / attachment step) can be carried out using cost-effective and reliable methods.

[0178] In another preferred embodiment of the present invention, the cover element is a sealing element, and the sealing element is a coating. Preferably, the coating is made of a material or combination thereof that reduces the leakage of sublimation vapor, particularly Si vapor, generated during the process and entering the furnace volume from the crucible volume through the crucible housing by at least 50% (mass), at least 80% (mass), at least 90% (mass), 99% (mass), or at least 99.9% (mass).

[0179] Preferably, the coating can withstand temperatures higher than 2000°C, particularly at least or up to 3000°C, or at least up to 3000°C, or at least up to 3500°C, or at least up to 3500°C, or at most 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 forming the crucible skin and the other layer reducing the transmission of Si vapor. Most preferably, the coating comprises one or more materials selected from the group of materials comprising at least carbon, particularly pyrocarbon and glassy carbon. Thus, the crucible unit, particularly the crucible housing or the housing of the crucible unit, is preferably coated with pyrocarbon and / or glassy carbon. Preferably, the pyrocarbon layer has a thickness greater than or up to 10 μm, particularly greater than or up to 20 μm, greater than or up to 50 μm, greater than or up to 100 μm, greater than or up to 200 μm, or greater than or up to 500 μm. Preferably, the glassy carbon layer has a thickness greater than or up to 10 μm, particularly greater than or up to 20 μm, greater than or up to 50 μm, greater than or up to 100 μm, greater than or up to 100 μm, greater than or up to 200 μm, or greater than or up to 500 μm.

[0180] In yet another preferred embodiment, the coating is produced by chemical vapor deposition, or in particular by printing phenol formaldehyde onto a precursor material and subsequent thermal decomposition. This embodiment is advantageous because it allows the coating to be generated in a reliable manner.

[0181] In another preferred embodiment of the present invention, the leak inhibitor is a density-increasing element or sealing element for increasing the density of the volume portion of the crucible housing of the crucible unit, wherein the density-increasing element is arranged in or achieved within the internal structure of the crucible housing, and the density-increasing element is a sealing element. The coating prevents leakage of sublimation vapor, particularly Si vapor, generated during the process and entering the furnace volume from the crucible volume through the crucible housing, by at least 50% (mass), at least 80% (mass), at least 90% (mass), 99% (mass), or at least 99.9% (mass). This embodiment is advantageous because the dimensions of the crucible unit remain the same or similar or are not affected by modifications. Preferably, the sealing element is achieved by impregnation or deposition inside the crucible housing.

[0182] In another preferred embodiment of the present invention, the leak prevention means is a filter unit for recovering Si gas. The filter unit comprises a filter body, which has a filter input surface or filter input section for introducing a gas containing SiC chemical seed vapor, Si vapor, and a process gas into the filter body, and an output section or filter output surface for outputting the filtered process gas. Between the filter input surface and the filter output surface, a filter element is arranged to form a capture section for adsorbing and condensing SiC chemical seed vapor, particularly Si vapor. Preferably, the filter material is such that it allows for the absorption and condensation of Si vapor onto its surface. This design is advantageous because the total amount of Si vapor inside the crucible unit can be significantly reduced by utilizing the filter unit. This also significantly reduces the amount of Si vapor that could leak out. Most preferably, all of the Si vapor is recovered, preferably as a condensate film on the inner surface of the filter. In addition to or instead of this, a section is defined within the uppermost part of the filter where the temperature is below the melting point of Si and the vapor condensate actually solidifies. Preferably, the Si vapor does not solidify into particles, and a solid film is preferably formed on the inner surface of the filter. This film may be amorphous or polycrystalline. Excess Si2C and SiC2 vapors preferably also reach the lower region of the filter and are deposited on its inner surface, preferably as a solid polycrystalline deposit.

[0183] In 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 up to 1000 times longer than S1, or at least or up to 10000 times longer than S1. This embodiment is advantageous because the filter unit has the function of absorbing or capturing more than 50% (by mass) or up to 50% (by mass), in particular more than 50% (by mass) or up to 50% (by mass), more than 70% (by mass) or up to 70% (by mass), more than 90% (by mass) or up to 90% (by mass), more than 95% (by mass) or up to 95% (by mass), more than 99% (by mass) or up to 99% (by mass). Preferably, "operation" means the generation or formation of crystals, particularly SiC crystals, SiC blocks, or SiC boules.

[0184] In another preferred embodiment of the present invention, the filter unit is positioned between a first portion of the crucible unit housing and a second portion of the crucible unit housing, particularly the crucible lid or filter lid. At least 50% (volume), particularly at least 80% (volume), or at least 90% (volume) of the first portion of the crucible unit housing is positioned vertically below the seed holder unit, and a first crucible volume exists between the first portion of the crucible unit housing and the seed holder, and the first crucible volume can be operated such that at least 80%, preferably 90%, or more preferably 100%, of which it is higher than the silicon condensation temperature Tc under general pressure. Furthermore, up to 50% (volume), up to 20% (volume), or up to 10% (volume) of the first portion of the crucible unit housing is positioned vertically above the seed holder unit. Alternatively, at least 50% (volume), particularly at least 80% (volume) or 90% (volume) of the first housing portion of the crucible unit is positioned vertically above the seed holder unit. Preferably, the second crucible volume is positioned between the second portion of the housing of the crucible unit and the seed holder unit. At least 60%, preferably 80%, or more preferably 90%, of the filter elements is below the condensation temperature Tc. Thus, the thermal conditions within the filter elements of the filter unit allow for the condensation of Si vapor. Consequently, the filter elements can very substantially condense or capture Si.

[0185] In another preferred embodiment of the present invention, the filter unit is positioned between a first wall portion of a first part of the housing and yet another wall portion of a second part of the housing, the filter body forming the filter outer surface, the filter outer surface connecting the first wall portion of the first part of the housing and yet another wall portion of the second part of the housing, and the filter outer surface forming part of the outer surface of this bridging unit. This embodiment is advantageous because it allows the use of a larger size filter unit without increasing the amount of material of the crucible housing of the crucible unit.

[0186] In another preferred embodiment of the present invention, the outer surface of the filter comprises a filter surface cover element. The filter surface cover element is preferably a sealing element, the sealing element is preferably a coating, the coating is preferably generated on the filter surface, attached to the filter surface, or forms the filter surface. Preferably, the coating consists of a material or combination thereof that reduces the leakage of sublimation vapor, particularly Si vapor, generated during the process and entering the furnace volume from the crucible volume through the crucible housing by at least 50% (mass), at least 80% (mass), at least 90% (mass), 99% (mass), or at least 99.9% (mass). The coating is withstands temperatures higher than 2000°C, particularly at least or up to 3000°C, or at least up to 3000°C, or at least up to 3500°C, or at least up to 4000°C, or at least up to 4000°C.

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

[0188] In another preferred embodiment of the present invention, the filter body forms an inner filter surface. The inner surface of the filter or the inner surface of the filter is preferably arranged coaxially with the outer surface of the filter. The filter body is preferably annular in shape. The outer filter surface is preferably cylindrical, and / or the inner filter surface is preferably cylindrical. The outer and inner surfaces of the filter extend vertically. This embodiment is advantageous because the filter unit can be used in a circular crucible unit and / or a crucible unit having a circular crucible volume. Therefore, the filter unit, or the furnace apparatus in which it is positioned, does not require any substantial modifications, and thus the furnace apparatus according to the present invention can be manufactured at low cost.

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

[0190] Preferably, the coating can withstand temperatures higher than 2000°C, particularly higher than 2200°C, or higher than 2000°C, particularly 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. Preferably, the coating has at least carbon, and more particularly one or more materials selected from the group of materials comprising pyrocarbon and glassy carbon. Thus, the filter unit, particularly its inner surface, is preferably coated with pyrocarbon and / or glassy carbon. Preferably, the pyrocarbon layer has a thickness greater than or up to 10 μm, particularly greater than or up to 20 μm, greater than or up to 50 μm, greater than or up to 100 μm, greater than or up to 200 μm, or greater than or up to 500 μm. Preferably, the glassy carbon layer has a thickness greater than or up to 10 μm, particularly greater than or up to 20 μm, greater than or up to 50 μm, greater than or up to 100 μm, greater than or up to 200 μm, or greater than or up to 500 μm.

[0191] In another preferred embodiment of the present invention, the filter element comprises a filter element member comprising filter particles and a binder. The filter particles are made of or composed of carbon, and the binder holds the filter particles in fixed relative positions. The filter particles are resistant to temperatures above 2000°C, particularly above 2000°C, particularly above 2000°C, particularly at least or up to 3000°C, or at least at least at least 3000°C, up to 3500°C, at least at least at least 3500°C, up to 4000°C, or at least This embodiment is advantageous because it provides a filter unit that can withstand the conditions inside the crucible unit during the operation of the furnace apparatus. Furthermore, the combination of filter particles and binder forms a substantially larger area compared to the outer area of ​​the filter unit, in particular by up to or at least 10 times, up to or at least 100 times, up to or at least 10,000 times, or up to or at least 10,000 times larger. This embodiment is further advantageous because the filter unit has the ability to absorb or incorporate more than 50% (by mass) or up to 50% (by mass) of the starting material, in particular more than 50% (by mass) or up to 50% (by mass), more than 70% (by mass) or up to 70% (by mass), more than 90% (by mass) or up to 90% (by mass), more than 95% (by mass) or up to 95% (by mass), more than 99% (by mass) or up to 99% (by mass).

[0192] In 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, particularly higher than 2000°C or up to 2000°C, particularly 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, particularly 2000°C, particularly 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] In yet another preferred embodiment of the present invention, the gas inlet is located between the receiving space and the seed holder unit, preferably the gas inlet is located closer to the receiving space than the seed holder unit in the vertical direction, and 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, and 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 evenly delivers the vapor of the starting material to the seed wafer 18 or the crystal growth front.

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

[0196] In yet another preferred embodiment of the present invention, the gas distribution element is positioned at a predetermined distance from the bottom surface of the crucible unit, particularly the inner bottom surface of the crucible unit. The predetermined 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 × the vertical distance between the receiving space and the gas inlet (i.e., less than half the vertical distance between the receiving space and the gas inlet), or less than 0.3 × the vertical distance between the receiving space and the gas inlet, or less than 0.1 × the vertical distance between the receiving space and the gas inlet, or less than 0.05 × the vertical distance between the receiving space and the gas inlet.

[0197] In another preferred embodiment of the present invention, the gas distribution element is a gas baffle. Preferably, the gas baffle forms a bottom surface and an top surface. Preferably, the bottom surface and the top surface extend parallel to each other at least in sections. Preferably, the distance between the bottom surface and the top surface is less than 0.5 × the distance between the receiving space and the gas inlet, or less than 0.3 × the distance between the receiving space and the gas inlet, or less than 0.1 × the distance between the receiving space and the gas inlet, or less than 0.05 × the distance between the receiving space and the gas inlet. This embodiment is advantageous because it can use a truly thin gas distribution plate. This thin gas distribution plate is advantageous because it does not require a large amount of material. Furthermore, this gas distribution plate does not affect the radiant heat emitted from the lower portion covered by it.

[0198] In 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 inside the furnace but outside the crucible unit that is higher than the first pressure, wherein the second pressure is below 200 Torr, particularly below 100 Torr, or below 50 Torr, particularly between 0.01 Torr and 30 Torr. Preferably, the second pressure is up to 10 Torr, up to 20 Torr, up to 50 Torr, up to 100 Torr, or up to 180 Torr higher than the first pressure. This embodiment is advantageous because leakage of Si vapor is prevented due to the higher pressure around the crucible unit.

[0199] In another preferred embodiment of the present invention, the pipe system is part of the furnace apparatus. Preferably, the pipe system comprises a first pipe or crucible pipe connecting the crucible volume to a vacuum unit and a second pipe or furnace pipe connecting the portion of the furnace surrounding the crucible unit to the vacuum unit. Preferably, the vacuum unit has control elements for controlling the pressure inside the crucible volume and the pressure inside the portion of the furnace surrounding the crucible unit. Preferably, the vacuum unit reduces the pressure inside the crucible volume through the crucible tube or the pressure inside the portion of the furnace surrounding the crucible unit through the furnace tube when the control elements determine that the pressure inside the crucible volume has exceeded a first threshold and / or the pressure inside the portion of the furnace surrounding the crucible unit has exceeded a second threshold. 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] In another preferred embodiment of the present invention, the furnace system comprises two or more leak prevention means selected from the group comprising leak prevention means. This embodiment is advantageous because the furnace apparatus comprises at least a cover element and / or density-increasing element and a filter unit for collecting Si gas, the furnace apparatus may comprise at least a cover element and / or 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 may 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, the furnace device may also include 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 it can prevent Si vapor leakage in various ways, allowing the furnace unit according to the present invention to be equipped to satisfy requirements depending on various needs.

[0203] In yet another preferred embodiment of the present invention, the heating unit comprises at least one particularly horizontal heating element, the heating element positioned vertically below the receiving space. Preferably, the heating element overlaps the receiving space at least partially, preferably mostly or completely. This design is advantageous because the receiving space and the portion of the crucible volume or 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 portion of the crucible volume or crucible housing surrounded by the receiving space are the same for seed wafers 18 having a small diameter or seed wafers 18 having a larger diameter. This allows for uniform heating of the starting material. Preferably, the heating unit further comprises at least one yet another particularly vertical heating element, preferably the yet another heating element positioned next to the crucible unit, particularly next to the sidewalls of the crucible unit surrounding the crucible unit. Preferably, the heating element and / or further heating elements are located outside the crucible unit, particularly inside the furnace insert which is outside the crucible volume.

[0204] In yet another preferred embodiment of the present invention, the receiving space is formed within the wall portion of the crucible unit or within the inner wall portion or bottom portion of the crucible unit. Preferably, the receiving space extends around a central axis coaxial with the central axis of the seed holder unit. Preferably, the receiving space is located at a predetermined distance from the central axis.

[0205] In yet another preferred embodiment of the present invention, a gas tube or gas guide device for introducing gas into a crucible unit is provided. The gas tube or gas guide means, a portion of the gas tube or gas guide means, a gas inlet attached to the gas tube or gas guide means, or a portion of the gas tube or gas guide means is at least partially, preferably mostly or completely, surrounded by a receiving space. Preferably, the gas tube or gas guide means extends at least partially in the direction of the central axis. Preferably, the gas tube or gas guide means enters through the bottom portion of the crucible unit or the bottom portion 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 guide device. Furthermore, since the gas inlet is surrounded by the receiving volume, the gas introduced through the gas inlet can be distributed particularly evenly to different portions of the receiving volume. In this way, a mixture of the injected gas and the evaporating raw material can be generated in a particularly uniform manner.

[0206] In another preferred embodiment of the present invention, the receiving space has an annular shape. Preferably, the receiving space is formed or created as a trench, particularly a circular trench, or by a plurality of recesses, particularly circular recesses. Preferably, these plurality of recesses are arranged along a predetermined contour, preferably having a circular shape. This embodiment is advantageous because the seed wafer 18 is preferably circular in shape. Thus, the starting material vapor is advantageously approached by the growth surface of the seed wafer 18 or the growth surface of the crystal being grown.

[0207] In yet another preferred embodiment of the present invention, the defined distance between the receiving space and the central axis is up to 30%, up to 20%, up to 10%, up to 5%, or up to 1% shorter than the diameter of the defined seed wafer 18. Alternatively, the defined distance between the receiving space and the central axis is up to 1%, up to 5%, up to 10%, up to 20%, or up to 30% longer than the diameter of the defined seed wafer 18. Alternatively, the defined distance between the receiving space and the central axis is equal to the diameter of the defined seed wafer 18. This embodiment is advantageous because it further facilitates the even distribution of the starting material vapor across the growth surface of the seed wafer 18 or across the growth surface of the crystal being grown.

[0208] In another preferred embodiment of the present invention, the receiving space surrounds the bottom portion of the housing or the upper portion of the housing bottom. The bottom section is a solid material section. Preferably, the solid material section or the heavy bottom section of the crucible has a height (vertical) or wall thickness 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 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 a heating unit. When the lower portion is heated, this heating also heats the space between the seed wafers 18, as well as the seed wafers 18. The lower portion is preferably a solid material block and / or a crucible-shaped solid bottom section, so that heating of the space between the seed wafer 18 and the bottom section, and heating of the seed wafer 18 or the growth surface of the growing crystal are carried out in an even manner. Preferably, the bottom portion has an outer surface portion which is preferably the surface portion of the crucible body, and preferably an inner surface portion which is parallel to the outer surface portion. This is advantageous because it allows the bottom portion to be heated evenly. The inner surface portion of the bottom portion is preferably a flat surface which is arranged in a horizontal plane. Preferably, the inner surface portion is arranged which is parallel to the surface of the seed wafer 18. This embodiment is advantageous because it allows the space between the seed wafer 18 and the bottom portion, as well as the seed wafer 18 and / or the growth surface of the growing crystal to be heated evenly.

[0209] Accordingly, the bottom section is positioned 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 aligned on the same vertical axis, and the inner surface of the bottom section is preferably positioned at a predetermined distance 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 it allows for the growth of large (wide and / or long) crystals.

[0210] The filter unit is positioned vertically above the receiving chamber. This embodiment is advantageous because the evaporating raw material and / or the injected gas flows from the lower crucible section to the upper crucible section, and therefore, preferably, the filter unit is positioned in the gas flow path.

[0211] In 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 introduction gas or a mixture of the starting material vapor and the introduction gas can preferably pass evenly through the cylindrical side wall. In this way, the accumulation of starting material vapor and / or the introduction gas can be pre-aerated. This pre-aeration is advantageous because it allows for uniform crystal growth. Preferably, uniform growth means that the growth rate on all face portions of the crystal growth area is within a defined range and / or the accumulation of defects and / or doping is uniformly distributed, where the term “uniformly distributed” defines an acceptable range of deviation.

[0212] In 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 the shape of the housing does not cause any significant complexity and therefore 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 space, 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 to or instead of the above, the inner diameter of the receiving space is preferably at least 1.05 × larger, preferably at least 1.1 × larger, preferably at least 1.3 × larger, or preferably at least 1.5 × larger compared to the inner diameter of the filter unit. Alternatively, the inner diameter of the filter unit is preferably at least 1.05 × larger, preferably at least 1.1 × larger, preferably at least 1.3 × larger, or preferably at least 1.5 × larger compared to the inner diameter of the receiving space.

[0213] In another preferred embodiment of the present invention, a growth guide element is positioned or provided vertically above the receiving space to guide the starting material vapor and / or introduction gas into the space between the seed holder unit and the inner bottom surface of the crucible unit. This embodiment is advantageous because the growth guide element preferably performs several functions. On the one hand, the growth guide element guides the starting material vapor to the seed wafer 18 or the crystal under growth. On the other hand, the growth guide element influences the shape of the crystal by limiting the radial expansion of the crystal under growth.

[0214] In another preferred embodiment of the present invention, the growth guide element comprises a first wall section or first growth guide section and a second wall section or second growth guide section. Preferably, the first growth guide section is molded to align with a corresponding wall section of the crucible housing. Preferably, the alignment in this context means that the wall portion of the crucible housing and the growth guide member are joined preferably by a tight fit and / or press fit. The second portion of the growth guide is preferably molded to manipulate the shape of the crystal during growth. In another preferred embodiment of the present invention, the first portion of the growth guide and the second portion of the growth guide are coaxially arranged. The first section of the growth guide is located at a location of a first diameter with respect to the central axis, and the second section of the growth guide is located at a location of a second diameter with respect to the central axis, where the first diameter is larger than the second diameter. The first growth guide section and the second growth guide section are interconnected by a third wall section and the third growth guide section, respectively, where the third growth guide section extends at least partially horizontally. The first growth guide section and the third growth guide section form an arc-shaped section and a fourth growth guide section, respectively, and / or the second growth guide section and the third growth guide section are positioned at an angle between 60° and 120°, particularly between 70° and 110°, and especially at an angle of 90°. The fourth growth guide section may have, for example, a convex, concave, or 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 manufactured from graphite. This embodiment is advantageous because the growth guide elements have a simple but effective shape. Therefore, the growth guide elements can be manufactured in a cost-effective manner.

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

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

[0217] In yet another preferred embodiment of the present invention, the coating is preferably applied to the receiving space within the crucible volume, particularly its surfaces, and / or to the growth guide element, growth guide plate, or gas distribution plate. Preferably, the coating has a material or combination thereof that reduces the transmission rate of Si vapor through the wall portions defining the boundaries of the receiving space and / or the wall portions defining the boundaries of the growth guide element to 10⁻³ m² / s, preferably 10⁻¹¹ m² / s, or more preferably 10⁻¹² m² / s.

[0218] Preferably, the coating can withstand temperatures higher than 2000°C, particularly at least or up to 3000°C, or at least up to 3000°C, or at least up to 3500°C, or at least up to 4000°C, or at least up to 4000°C. This embodiment is advantageous because the modified suppression element and / or growth guide element has at least two material layers, one of which forms the structure of the suppression element and / or growth guide element, and the other which reduces or avoids the transmission of Si vapor. Most preferably, the coating has at least carbon, particularly one or more materials selected from the group of materials comprising pyrocarbon and glassy carbon. Therefore, preferably, the receiving space and / or growth conduction element is coated with pyrocarbon and / or glassy carbon. Preferably, the pyrocarbon layer has a thickness greater than or up to 10 μm, particularly greater than or up to 20 μm, greater than or up to 50 μm, greater than or up to 100 μm, greater than or up to 200 μm, or greater than or up to 500 μm. Preferably, the glassy carbon layer has a thickness greater than or up to 10 μm, particularly greater than or up to 20 μm, greater than or up to 50 μm, greater than or up to 100 μm, greater than or up to 200 μm, or greater than or up to 500 μm. Furthermore, in a preferred embodiment, the coating is produced by chemical vapor deposition, or in particular by printing phenol formaldehyde onto a precursor material and subsequent thermal decomposition. This embodiment is advantageous because it allows the coating to be generated in a reliable manner.

[0219] In another preferred embodiment of the present invention, the heating unit comprises at least one heating element. Preferably, the heating element is positioned vertically below the receiving space and / or below the bottom portion of the crucible unit, the bottom portion of the crucible unit being surrounded by the receiving space. This design is advantageous because the receiving space and / or the bottom section surrounded by it can be heated by the heating element. Preferably, the heating element overlaps the receiving space and / or the bottom section surrounded by it by at least partially, preferably more than 50%, more than 70%, or up to 90%, or completely. This design is advantageous because it can establish a uniform temperature distribution and, in particular, can generate a uniform temperature level.

[0220] In yet another preferred embodiment of the present invention, the furnace apparatus comprises a gas flow unit. Preferably, the gas flow unit has a gas inlet for conducting gas into the crucible unit or crucible volume and a gas outlet for drawing gas out of the crucible unit or crucible volume. Preferably, the gas inlet is located closer to the bottom of the crucible unit than the gas outlet. Preferably, both the gas inlet and gas outlet are located within the crucible volume. This design is advantageous because it can influence 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.

[0221] In another preferred embodiment of the present invention, the gas outlet comprises a gas transport means, particularly a tube. Preferably, the gas outlet has a sensor, particularly a temperature sensor and / or pressure sensor, which is disposed inside the tube or as part of the tube or attached to the outer wall of the tube. This embodiment is advantageous because it allows monitoring of temperature and / or pressure conditions.

[0222] In addition to or instead of the above, in yet another preferred embodiment of the present invention, the gas inlet comprises a gas conduction means, in particular a pipe. Preferably, the gas inlet has a conduit means, in particular inside the tube or disposed as part of the conduit means or attached to the outer wall of the conduit means, in particular a temperature sensor and / or a pressure sensor. This embodiment is advantageous because it allows monitoring of temperature and / or pressure conditions.

[0223] In 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 the pyrometer can be used multiple times, making it a very cost-effective solution.

[0224] In another preferred embodiment of the present invention, sensors in the gas inlet and / or gas outlet are connected to a control unit. This embodiment is advantageous because the control unit receives sensor signals or sensor data. Thus, the control unit can output conditions within the crucible unit to the operator, particularly as a function of timestamps, in order to monitor the generation or growth process. In addition to or instead of this, the control unit can be given control rules, and the oven apparatus can be controlled depending on these control rules, time, and / or sensor outputs.

[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, crucible bottom wall, or crucible bottom section extending at least a distance V1 in the vertical direction. 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, particularly, 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, V, < ., or V2 < 2×V1.

[0226] Therefore, preferably, the receiving space surrounds the lower portion of the housing and has a surface that is particularly surrounded by the receiving space. The bottom portion is preferably a solid material portion. Preferably, the bottom portion of the solid crucible has a height (vertical) greater than 0.3 × the minimum distance between the receiving space and the central axis, or 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 0.9 × the minimum distance between the receiving space and the central axis, or greater than 1.1 × 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.

[0227] In another preferred embodiment of the present invention, the bottom portion has a surface surrounded by an inner surface or a receiving space. The inner surface of the bottom portion is preferably positioned parallel to the seed holder unit within the crucible volume. The center of the inner surface and the center of the seed holder, and / or the center of the seed wafer 18 held by the seed holder unit are preferably positioned on the same vertical axis. Preferably, the inner surface of the lower portion is positioned at a predetermined distance 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 it has a rotationally symmetric shape at least in each section, preferably mostly or completely, that facilitates the even distribution of the starting material vapor onto the seed wafer 18 or the growing crystal.

[0228] In 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 top surface of the defined seed wafer 18, a size of at least 0.8 × the size of the top surface of the defined seed wafer 18, a size of at least 0.9 × the size of the top surface of the defined seed wafer 18, a size of at least 1 × the size of the top surface of the defined seed wafer 18, and a size of at least 1.1 × the size of the top surface of the defined seed wafer 18. In addition or alternatively, the centers of the surface surrounded by the receiving space and the centers of the top surface of the defined seed wafer 18 are preferably located on the same vertical axis. In addition or alternatively, the surface surrounded by the receiving space and the top surface of the defined seed wafer 18 are preferably located parallel to each other. This embodiment is advantageous because heat distribution can be carried out evenly across the surface surrounded by the receiving space.

[0229] In another preferred embodiment of the present invention, a control unit is provided for controlling the pressure level in the crucible unit and / or 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, 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 control crystal growth by changing one or more operating parameters of the above-mentioned units.

[0230] Another preferred embodiment of the present invention provides a filter unit. Preferably, the filter unit surrounds a seed crystal holder unit and / or preferably at least partially above the seed crystal holder unit, and in particular at least 60% (by volume) of the filter unit is positioned above the seed crystal holder unit. The filter unit comprises a filter body, the filter body comprising a filter input surface for introducing a gas containing Si vapor into the filter body and an output surface for releasing the filtered gas, preferably the filter input surface being positioned vertically at a level below the level of the output surface. At least one or exactly one filter element is positioned 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 the Si vapor inside the filter element and thus reduce defects caused by the Si vapor. Preferably, the separation zone comprises at least or up to 50% (volume), at least or up to 80% (volume), or at least or up to 90% (volume) of the filter element volume. That is, 1% to 50% (volume), 10% to 50% (volume), or 1% to 30% (volume) of the filter element volume can be a steam section or a section in which the evaporating raw material is in a steam configuration.

[0231] In 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, where S2 is at least 10 times longer than S1, and in particular 100 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 crystal growth, particularly during SiC crystal growth. Therefore, preferably, the filter element forms a highly porous area for incorporating Si sublimation vapor during PVT growth, particularly SiC single crystallization. Preferably, the filter element has a material having an area of ​​at least 100 m² / g or at least 1000 m² / g.

[0232] In another preferred embodiment of the present invention, the filter unit is positioned between a first portion of the crucible unit housing and a second portion of the crucible unit housing. At least 50% (volume), particularly at least 80% (volume) or 90% (volume) of the first housing portion of the crucible unit is positioned vertically below the seed holder unit. A first crucible volume is provided between the first housing portion 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 above the silicon condensation temperature Tc under typical pressure. Furthermore, up to 50% (volume), up to 20% (volume), or up to 10% (volume) of the first portion of the crucible unit housing is positioned vertically above the seed holder unit. Alternatively, at least 50% (volume), particularly at least 80% (volume) or 90% (volume) of the first housing portion of the crucible unit is positioned vertically above the seed holder unit. Preferably, a second crucible volume is provided between the second housing portion of the crucible unit and the seed holder. At least 60%, preferably 80%, or more preferably 90% of the filter element is below the condensation temperature Tc. This embodiment is advantageous because the output material is evaporated or made to evaporate at or above Tc, or condensed or made to condense at or below Tc. Thus, the Si condensate can be captured within the filter element by using the fact that Si vapor condenses at a temperature below a predetermined temperature. Therefore, the filter element is very effective.

[0233] In another preferred embodiment of the present invention, the filter unit is positioned between a first wall portion of a first housing portion and yet another wall portion of a second housing portion. Preferably, the filter body forms the filter outer surface. Preferably, the filter outer surface connects the first wall portion of the first housing portion and yet another wall portion of the second housing portion. 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 positioned to increase the volume of the crucible unit without requiring one or more additional crucible housing portions.

[0234] In another preferred embodiment of the present invention, the outer surface of the filter 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 the filter surface, attached to the filter surface, or forms the filter surface. Preferably, the coating has a material or combination thereof that reduces the leakage of sublimation vapor, particularly Si vapor, generated during the process and entering the furnace volume from the crucible volume through the crucible housing by at least 50% (mass), at least 80% (mass), at least 90% (mass), 99% (mass), or at least 99.9% (mass).

[0235] Preferably, the coating can withstand temperatures higher than 2000°C, particularly at least or up to 3000°C, or at least up to 3000°C, or at least up to 3500°C, or at least 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 pyrocarbon and glassy carbon. This embodiment is advantageous because the filter unit can form an outer barrier of the crucible unit. Therefore, preferably, the filter unit absorbs or captures Si, and preferably prevents Si vapor from leaking. The ash content of the filter element is preferably less than 5% (by mass) or less than 1% (by mass). This means that less than 5% or less than 1% of the mass of the filter element is ash.

[0236] In another preferred embodiment of the present invention, the filter body forms an inner filter surface. The inner surface of the filter is preferably coaxial with the outer surface of the filter. The filter body is preferably annular in shape. The outer surface of the filter is preferably cylindrical, and / or the inner surface of the filter is preferably cylindrical. The outer surface of the filter and / or the inner surface of the filter have their longest extensions 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 surface of the filter 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 the seed holder unit. Preferably, a cooling unit can be provided comprising at least one cooling tube for guiding a coolant. This cooling tube can be arranged to surround the crucible unit at least partially, at least mostly (greater than 50% in the circumferential direction), or completely. In addition to or instead of this, the cooling tube can be arranged inside the crucible volume, in particular in the space surrounded by the inner surface of the filter. However, the cooling tube can also extend from the outside of the crucible unit through the walls of the crucible unit and / or the walls of the filter unit into the crucible volume, particularly into the space surrounded by the inner surface of the filter. Furthermore, the cooling tube can extend to the outside of the furnace. This embodiment is advantageous because it allows for favorable control of the temperature inside the crucible unit. Moreover, it is possible to set a temperature distribution profile within the crucible volume with a considerably steeper gradient compared to a situation without a cooling unit.

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

[0238] Preferably, the coating can withstand temperatures higher than 2000°C, particularly at least or up to 3000°C, or at least up to 3000°C, or at least up to 3500°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 pyrocarbon and glassy 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 consists of activated carbon blocks and / or one or more particularly different graphite foams, including those made of carbonized pan, rigid graphite insulators, and / or flexible graphite insulators.

[0240] In 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 fixed relative positions. Preferably, the filter particles can withstand temperatures higher than 2000°C, particularly at least or up to 3000°C, or at least at most 3000°C, or at most at most 3500°C, or at most at most 3500°C, or at most at most 4000°C. Preferably, the filter particles can withstand temperatures higher than 2000°C, particularly at least or up to 3000°C, or at least at most 3000°C, or at most at most 3500°C, or at least at most at most 4000°C. Preferably, the filter particles can withstand temperatures higher than 1700°C, particularly higher than 2000°C, particularly up to 2000°C, or higher than 2000°C, particularly 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 elements do not contain toxic materials. In addition, the solid filter elements can be manufactured at low cost. The filter unit, particularly the filter elements, are preferably disposable units or elements.

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

[0242] In 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 a crucible unit and a gas outlet for releasing gas from the crucible unit through the furnace to the outside of the furnace. Preferably, the gas inlet is located 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 located downstream of the filter unit in the gas flow direction. Thus, preferably, the gas inlet is located in a 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 transitioned 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 is preferably mixed and / or reacted with the starting material in the vapor configuration and / or during solidification. Preferably, the gas outlet is located in a capture zone, which further comprises the outlet surface of the filter unit, and the gas composition in the capture zone is preferably Si vapor-free or does not contain Si vapor. The temperature in the intake 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, in particular accelerate, the vapor transport from the receiving space to the seed wafer 18 or the crystal. Preferably, uniform growth means that the growth rate on all face portions of the crystal growth area is within a defined range, and / or defect accumulation and / or doping is uniformly distributed, where the term “uniformly distributed” defines an acceptable range of deviation.

[0243] In 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 the shape of the housing does not cause any significant complexity and therefore enables inexpensive manufacturing. The outer diameter of the filter unit is preferably at least or up to 1.05 × compared to the outer diameter of the receiving chamber, or preferably at least or up to 1.1 × compared to the outer diameter of the receiving space, or preferably at least or up to 1.3 × compared to the outer diameter of the receiving space, or preferably at least or up to 1.5 × compared to the outer diameter of the receiving space. Alternatively, the outer diameter of the receiving space is preferably at least or up to 1.05 × compared to the outer diameter of the filter unit, or preferably at least or up to 1.1 × compared to the outer diameter of the filter unit, or preferably at least or up to 1.3 × compared to the outer diameter of the filter unit, or preferably at least or up to 1.5 × compared to the outer diameter of the filter unit. In addition to or instead of the above, the inner diameter of the receiving space is preferably at least 1.05 × larger, preferably at least 1.1 × larger, preferably at least 1.3 × larger, or preferably at least 1.5 × larger compared to the inner diameter of the filter unit. Alternatively, the inner diameter of the filter unit is preferably at least 1.05 × larger, preferably at least 1.1 × larger, preferably at least 1.3 × larger, or preferably at least 1.5 × larger compared to the inner diameter of the receiving space.

[0244] In another preferred embodiment of the present invention, a growth guide element is positioned or provided vertically above the receiving space for guiding the starting material vapor and / or introduction gas into the space between the seed holder unit and the inner bottom surface of the crucible unit. This embodiment is advantageous because the growth guide element preferably performs several functions. On the one hand, the growth guide element guides the starting material vapor to the seed wafer 18 or the crystal under growth. On the other hand, the growth guide element influences the shape of the crystal by limiting the radial elongation of the crystal under growth.

[0245] In another preferred embodiment of the present invention, the growth guide element comprises a first wall section or first growth guide section and a second wall section or second growth guide section. Preferably, the first growth guide section is molded to align with a corresponding wall section of the crucible housing. Preferably, the alignment in this context means that the wall portion of the crucible housing and the growth guide member are joined preferably by a tight fit and / or press-fit connection. The second portion of the growth guide is preferably molded to manipulate the shape of the crystal during growth. In another preferred embodiment of the present invention, the first portion of the growth guide and the second portion of the growth guide are coaxially arranged. The first section of the growth guide is located at a location of a first diameter with respect to the central axis, and the second section of the growth guide is located at a location of a second diameter with respect to the central axis, where the first diameter is larger than the second diameter. The first and second growth guide sections are interconnected by a third wall section and the third growth guide section, respectively, where the third growth guide section extends at least partially horizontally. The first and third growth guide sections form an arc-shaped section and a fourth growth guide section, respectively, and / or the second and third growth guide sections are arranged at an angle between 60° and 120°, particularly between 70° and 110°, particularly at an angle of 90°. The fourth growth guide section may have, for example, a convex, concave, or conical shape. The first wall section, the second section of the growth support, and the third section of the growth support are preferably integral parts of the growth support. Preferably, the growth support is manufactured from graphite. This embodiment is advantageous because the growth guide elements have a simple but effective shape. Thus, the growth guide elements can be manufactured in a cost-effective manner.

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

[0247] The upper vertical end of the second section of the growth guide 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 guide and the seed holder unit is less than 0.3 × the second diameter of the growth guide, or less than 0.1 × the second diameter of the growth guide, or less than 0.08 × the second diameter of the growth guide, or less than 0.05 × the second diameter of the growth guide, or less than 0.03 × the second diameter of the growth guide, or less than 0.01 × the second diameter of the growth guide.

[0248] In yet another preferred embodiment of the present invention, the coating is preferably applied to the receiving space within the crucible volume, particularly its surfaces, and / or to the growth guide element, growth guide plate, or gas distribution plate. Preferably, the coating has a material or combination thereof that reduces the transmission rate of Si vapor through the wall portions defining the boundaries of the receiving space and / or the wall portions defining the boundaries of the growth guide element to 10⁻³ m² / s, preferably 10⁻¹¹ m² / s, or more preferably 10⁻¹² m² / s.

[0249] Preferably, the coating can withstand temperatures higher than 2000°C, particularly at least or up to 3000°C, or at least up to 3000°C, or at least up to 3500°C, or at least up to 4000°C, or at least up to 4000°C. This embodiment is advantageous because the modified suppression element and / or growth guide element has at least two material layers, one of which forms the structure of the suppression element and / or growth guide element, and the other which reduces or avoids the transmission of Si vapor. Most preferably, the coating has at least carbon, particularly one or more materials selected from the group of materials comprising pyrocarbon and glassy carbon. Therefore, preferably, the receiving space and / or growth conduction element is coated with pyrocarbon and / or glassy carbon. Preferably, the pyrocarbon layer has a thickness greater than or up to 10 μm, particularly greater than or up to 20 μm, greater than or up to 50 μm, greater than or up to 100 μm, greater than or up to 200 μm, or greater than or up to 500 μm. Preferably, the glassy carbon layer has a thickness greater than or up to 10 μm, particularly greater than or up to 20 μm, greater than or up to 50 μm, greater than or up to 100 μm, greater than or up to 200 μm, or greater than or up to 500 μm. Furthermore, in a preferred embodiment, the coating is produced by chemical vapor deposition, or in particular by printing phenol formaldehyde onto a precursor material and subsequently by thermal decomposition. This embodiment is advantageous because it allows the coating to be generated in a reliable manner.

[0250] In another preferred embodiment of the present invention, the heating unit comprises at least one heating element. Preferably, the heating element is positioned vertically below the receiving space and / or below the bottom portion of the crucible unit, the bottom portion of the crucible unit being surrounded by the receiving space. This design is advantageous because the receiving space and / or the bottom section surrounded by it can be heated by the heating element. Preferably, the heating element overlaps the receiving space and / or the bottom section surrounded by it at least partially, preferably more than 50%, more than 70%, or up to 90%, or completely. This design is advantageous because it can establish a uniform temperature distribution and, in particular, generate a uniform temperature level.

[0251] In yet another preferred embodiment of the present invention, the furnace apparatus comprises a gas flow unit. Preferably, the gas flow unit has a gas inlet for conducting gas into the crucible unit or crucible volume and a gas outlet for drawing gas out of the crucible unit or crucible volume. Preferably, the gas inlet is located closer to the bottom of the crucible unit than the gas outlet. Preferably, both the gas inlet and gas outlet are located within the crucible volume. This design is advantageous because it can influence 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] In another preferred embodiment of the present invention, the gas outlet comprises a gas transport means, particularly a tube. Preferably, the gas outlet has a sensor, particularly a temperature sensor and / or pressure sensor, preferably a sensor disposed inside or as part of the tube, or a sensor attached to the outer wall of the tube. This embodiment is advantageous because it allows monitoring of temperature and / or pressure conditions.

[0253] In yet another preferred embodiment of the present invention, in addition to or instead of the gas inlet, the gas inlet comprises gas conduction means, particularly a pipe. Preferably, the gas inlet has conduit means, particularly inside the tube or disposed as part of the tube or attached to the outer wall of the tube, particularly a sensor, particularly a temperature sensor and / or a pressure sensor. This embodiment is advantageous because it allows monitoring of temperature and / or pressure conditions.

[0254] In 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 the pyrometer can be used multiple times, making it a very cost-effective solution.

[0255] In another preferred embodiment of the present invention, sensors in the gas inlet and / or gas outlet are connected to a control unit. This embodiment is advantageous because the control unit receives sensor signals or sensor data. Thus, the control unit can output conditions within the crucible unit to the operator, particularly as a function of timestamps, in order to monitor the generation or growth process. In addition to or instead of this, the control unit can be given control rules, and the oven apparatus can be controlled depending on these control rules, time, and / or sensor outputs.

[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 the crucible unit, particularly the surface disposed or provided inside the inner surface of its wall and / or 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 at least a distance V1 in the vertical direction. In 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 (that is, the distance V2 is larger in the vertical direction). That is, the distance V2 is larger compared to the distance V1, particularly, 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.

[0257] Therefore, preferably, the receiving space surrounds the lower portion of the housing and has a surface that is particularly surrounded by the receiving space. The bottom portion is preferably a solid material portion. Preferably, the bottom portion of the solid crucible has a height (vertical) greater than 0.3 × the minimum distance between the receiving space and the central axis, or 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 0.9 × the minimum distance between the receiving space and the central axis, or greater than 1.1 × 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.

[0258] In another preferred embodiment of the present invention, the bottom portion has a surface surrounded by an inner surface or a receiving space. The inner surface of the bottom portion is preferably positioned parallel to the seed holder unit within the crucible volume. The center of the inner surface and the center of the seed holder and / or the center of the seed wafer 18 held by the seed holder unit are preferably positioned on the same vertical axis. Preferably, the inner surface of the lower portion is positioned at a predetermined distance 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. The shape of this embodiment is advantageous because it has a rotationally symmetric shape at least in each section, preferably mostly or completely, that facilitates the even distribution of the starting material vapor onto the seed wafer 18 or the growing crystal.

[0259] In 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 top surface of the defined seed wafer 18, a size of at least 0.8 × the size of the top surface of the defined seed wafer 18, a size of at least 0.9 × the size of the top surface of the defined seed wafer 18, a size of at least 1 × the size of the top surface of the defined seed wafer 18, or a size of at least 1.1 × the size of the top surface of the defined seed wafer 18. In addition or alternatively, the center of the surface surrounded by the receiving space and the center of the top surface of the defined seed wafer 18 are preferably located on the same vertical axis. In addition or alternatively, the surface surrounded by the receiving space and the top surface of the defined seed wafer 18 are preferably located parallel to each other. This embodiment is advantageous because heat distribution can be carried out evenly across the surface surrounded by the receiving space.

[0260] In another preferred embodiment of the present invention, a control unit is provided for controlling the pressure level in the crucible unit and / or 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, 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 control crystal growth by changing one or more operating parameters of the above-mentioned units.

[0261] Another preferred embodiment of the present invention provides a filter unit. Preferably, the filter unit surrounds a seed holder unit and / or preferably at least partially above the seed holder unit, and in particular at least 60% (by volume) of the filter unit is positioned above the seed holder unit. The filter unit comprises a filter body, the filter body comprising a filter input surface for introducing a gas containing Si vapor into the filter body and an output surface for releasing the filtered gas, preferably the filter input surface being positioned vertically at a level below the level of the output surface. Between the filter input surface and the output surface, at least one or exactly one filter element is positioned. 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 because it can trap the Si vapor inside the filter element and thus reduce defects caused by the Si vapor. Preferably, the intake area comprises at least or up to 50% (volume), at least or up to 80% (volume), or at least or up to 90% (volume) of the filter element volume. Thus, 1% to 50% (volume), 10% to 50% (volume), or 1% to 30% (volume) of the filter element volume can be a steam section or a section in which the starting material steam is in the steam configuration.

[0262] In 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, where S2 is at least 10 times longer than S1, and in particular 100 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 crystal growth, particularly during SiC crystal growth. Therefore, preferably, the filter element forms a highly porous area for incorporating Si sublimation vapor during PVT growth, particularly SiC single crystallization. Preferably, the filter element has a material having an area of ​​at least 100 m² / g or at least 1000 m² / g.

[0263] In another preferred embodiment of the present invention, the filter unit is positioned between a first portion of the crucible unit housing and a second portion of the crucible unit housing. At least 50% (volume), particularly at least 80% (volume) or 90% (volume) of the first housing portion of the crucible unit is positioned vertically below the seed holder unit. A first crucible volume is provided between the first housing portion 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 above the silicon condensation temperature Tc under typical pressure. Furthermore, up to 50% (volume), up to 20% (volume), or up to 10% (volume) of the first portion of the crucible unit housing is positioned vertically above the seed holder unit. Alternatively, at least 50% (volume), particularly at least 80% (volume) or 90% (volume) of the first housing portion of the crucible unit is positioned vertically above the seed holder unit. Preferably, a second crucible volume is provided between the second housing portion of the crucible unit and the seed holder. At least 60%, preferably 80%, or more preferably 90% of the filter element is below the condensation temperature Tc. This embodiment is advantageous because the starting material is evaporated or made to evaporate at or above Tc, or condensed or made to condense at or below Tc. Thus, the Si condensate can be captured within the filter element by using the fact that Si vapor condenses at a temperature below a predetermined temperature. Therefore, the filter element is very effective.

[0264] In another preferred embodiment of the present invention, the filter unit is positioned between a first wall portion of a first housing portion and yet another wall portion of a second housing portion. Preferably, the filter body forms the filter outer surface. Preferably, the filter outer surface connects the first wall portion of the first housing portion and yet another wall portion of the second housing portion. 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 positioned to increase the volume of the crucible unit without requiring one or more additional crucible housing portions.

[0265] In another preferred embodiment of the present invention, the outer surface of the filter 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 the filter surface, attached to the filter surface, or forms the filter surface. Preferably, the coating has a material or combination thereof that reduces the leakage of sublimation vapor, particularly Si vapor, generated during the process and entering the furnace volume from the crucible volume through the crucible housing by at least 50% (mass), at least 80% (mass), at least 90% (mass), 99% (mass), or at least 99.9% (mass).

[0266] Preferably, the coating can withstand temperatures higher than 2000°C, particularly at least or up to 3000°C, or at least up to 3000°C, or at least up to 3500°C, or at least 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 pyrocarbon and glassy carbon. This embodiment is advantageous because the filter unit can form an outer barrier of the crucible unit. Therefore, preferably, the filter unit absorbs or captures Si, and preferably prevents Si vapor from leaking. The ash content of the filter element is preferably less than 5% (by mass) or less than 1% (by mass). This means that less than 5% or less than 1% of the mass of the filter element is ash.

[0267] In another preferred embodiment of the present invention, the filter body forms an inner filter surface. The inner surface of the filter is preferably coaxial with the outer surface of the filter. The filter body is preferably annular in shape. The outer surface of the filter is preferably cylindrical, and / or the inner surface of the filter is preferably cylindrical. The outer surface of the filter and / or the inner surface of the filter have their longest extensions 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 surface of the filter 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 the seed holder unit. Preferably, a cooling unit can be provided comprising at least one cooling tube for guiding a coolant. This cooling tube can be arranged to surround the crucible unit at least partially, at least mostly (more than 50% in the circumferential direction), or completely. In addition to or instead of this, the cooling tube can be arranged in the crucible volume, in particular in the space surrounded by the inner surface of the filter. However, the cooling tube can also extend from the outside of the crucible unit through the walls of the crucible unit and / or the walls of the filter unit into the crucible volume, particularly into the space surrounded by the inner surface of the filter. Furthermore, the cooling tube can extend to the outside of the furnace. This embodiment is advantageous because it allows for favorable control of the temperature inside the crucible unit. Moreover, it is possible to set a temperature distribution profile with a considerably steeper gradient within the crucible volume compared to a situation without a cooling unit.

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

[0269] Preferably, the coating can withstand temperatures higher than 2000°C, particularly at least or up to 3000°C, or at least up to 3000°C, or at least up to 3500°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 pyrocarbon and glassy 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 insulators, and / or flexible graphite insulators.

[0271] In 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 fixed relative positions. Preferably, the filter particles can withstand temperatures higher than 2000°C, particularly at least or up to 3000°C, or at least at most 3000°C, or at most at most 3500°C, or at most at most 4000°C. Preferably, the filter particles can withstand temperatures higher than 2000°C, particularly at least or up to 3000°C, or at least at most at most 3000°C, or at most Preferably, the filter particles can withstand temperatures higher than 1700°C, particularly higher than 2000°C, particularly up to 2000°C, or higher than 2000°C, particularly 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 elements do not contain toxic materials. Furthermore, the solid filter elements can be manufactured at low cost. The filter unit, particularly the filter elements, are preferably disposable units or elements.

[0272] In 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. Thus, 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 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 positioned within a capture zone and further includes 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] In another preferred embodiment of the present invention, the size of the crucible housing is configurable or modifiable. The crucible housing surrounds a first volume VI in the crystal growth configuration and a second volume VII in the coating regeneration configuration. The crystal growth configuration represents a configuration or setting that exists during crystal growth or on the seed wafer 18 or during the solidification of the starting material vapor at the growth front of the crystal growing on the seed wafer 18. The regeneration configuration represents a setting that exists when the seed holder unit 18 has been 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, which is located on top of the filter unit in the crystal growth configuration, preferably contacts a side wall portion of the crucible housing that is in contact with the lower end of the filter unit in the crystal growth configuration. Volume VI is preferably larger than Volume VII, and Volume VI is at least 10%, at least or up to 20%, at least or up to 30%, at least or up to 40%, at least or up to 50%, at least or up to 60%, at least or up to 70%, at least or up to 80%, at least or up to 100%, at least or up to 100%, at least or up to 120%, at least or up to 150%, at least or up to 200%, or at least or up to 250% larger than Volume VII. This embodiment is advantageous because the crucible unit can be readjusted after use, particularly after one or several processes, especially up to or at least three times, up to or at least five times, or up to or at least ten times. Thus, the overall service life of the crucible unit is very long. The heating unit can also be used multiple times, thus providing a very cost-effective furnace apparatus.

[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 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 for guiding 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 guide element rests at least partially on each gas distribution element, and preferably, the gas distribution element holds the receiving space gas guide element particularly by a tight connection. This embodiment is advantageous because it allows for quick and easy installation.

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

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

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

[0283] That is, a method and reactor or furnace apparatus or apparatus for PVT growth of SiC single crystals preferably comprises the steps of insulating and / or providing an interior vacuum chamber so that radially flat isotherms can be generated in the growing crystal, the crucible unit having a furnace volume capable of receiving a crucible unit and a heater, and having a lid, and / or a seed holder incorporated in or attached to the lid, and / or a SiC single crystal seed attached to the seed holder, and / or an axial heater located below the crucible unit, and / or arranging the source material in the crucible unit so that no source material is present between the axial heat source and the seed, and / or generating a vacuum in the crucible unit and heating and sublimating each source material, a SiC solid material (generated from the method according to the present invention), to grow a crystal, in particular a SiC single crystal.

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

[0285] This solution is advantageous because the vent gas can be reused, and therefore the recycled amount of Si, C, or at least one C-containing molecule, and H2 can be reused in the production of SiC material, particularly PVT source material. Thus, based on the initial amount of source gas, a considerably larger amount of SiC can be produced compared to a SiC production reactor that does not recycle the vent gas.

[0286] Preferably, the aeration gas recirculation unit comprises yet another separation unit for separating the first fluid into at least two parts, namely, a chlorosilane 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 chlorosilane mixture and a mixture of HCl, 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. Preferably, yet another separation unit is coupled with 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. Preferably, the storage element and / or conduction element for the chlorosilane mixture forms a section of a chlorosilane mixture mass flux path for conducting the chlorosilane mixture into the processing chamber. Preferably, a Si mass flux measuring unit for measuring the amount of Si in a chlorosilane 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, providing yet another Si feed medium. Preferably, storage elements and / or conduction elements for the chlorosilane mixture form a section of the chlorosilane mixture mass flux path for conducting the chlorosilane mixture into yet another processing chamber of yet another SiC production reactor. Preferably, storage elements and / or conduction elements for H2 and C form 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 measuring unit for measuring the amount of C in a 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, providing yet another C feed medium. Preferably, the H2 and C storage elements and / or conduction elements form sections of H2 and C mass flux pathways 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 H2 and C mass flux path 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 H2 and C storage element and / or conduction element are preferably fluid-coupled. Preferably, the second storage element and / or conduction element forms yet another section of the H2 and C mass flux path for conducting a second fluid comprising H2 and at least one C-containing molecule into the processing chamber. Preferably, yet another C mass flux measuring unit for measuring the amount of C in the second fluid is provided as part of yet another H2 and C mass flux path before the processing chamber, particularly before the mixing device. Alternatively, the second storage element and / or conduction element is coupled with a flare unit for burning 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 a separation unit or in a gas flow path between a gas outlet unit and a 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 a gas flow path between a 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 a SiC production reactor, and the multiple feed media comprise a first medium, a second medium and a third medium, and yet another Si feed medium and / or yet another C feed medium are supplied into the processing chamber through a gas inlet unit.Preferably, the Si feeding medium further comprises a mixture of chlorosilanes in an amount 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 more preferably at least 99,99999% (by mass). Preferably, another C-supplying medium comprises at least one C-containing molecule, HCl, H2, and a chlorosilane mixture, comprising 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, comprising 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, comprising more than 5% (by mass), preferably more than 10% (by mass), or very preferably more than 25% (by mass) of H2, and further comprising more than 0.01% (by mass), preferably more than 1% (by mass), very preferably between 0.001% (by mass) and 10% (by mass) of a chlorosilane mixture.

[0287] Preferably, a heating unit is positioned between another separation unit and a gas inlet unit in the direction of fluid flow in order to heat the chlorosilane mixture and transition it from liquid to gaseous form.

[0288] The processing chamber is surrounded by at least a base plate, a side wall section, and an upper wall section, preferably the base plate having at least one cooling element, particularly a base cooling element, to prevent it from heating above a specified temperature, and / or preferably the side wall section having at least one cooling element, particularly a bell jar cooling element, to prevent it from heating above a specified temperature, and / or preferably the upper wall section having at least one cooling element, particularly a bell jar cooling element, to prevent it from heating above a specified temperature. The cooling elements are preferably active cooling elements. Preferably the base plate, the side wall section, and / or the upper wall section are provided with a cooling fluid guide unit for guiding a cooling fluid, the cooling fluid guide unit being 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, side wall sections, and / or upper wall sections 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, and further preferably, a fluid forwarding unit is provided for forwarding the cooling fluid through a fluid guide 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, preferably water comprising at least one additive, in particular a rust inhibitor and / or an antifouling agent (biocide). The cooling element may be a passive cooling element in addition to or instead of the above. Preferably, the cooling element is at least partially formed by the polished steel surfaces of the base plate, side wall sections, and / or upper wall sections. The cooling element is preferably a coating, which is formed on the polished steel surface and configured to reflect heat.Preferably, the coating is a metallic coating, or a coating of metal, in particular silver, gold, chromium, or an alloy, in particular CuNi alloy, of a polished steel surface and / or coating. emissivity Preferably, εe is less than 0.3, particularly 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 heating above a specified temperature, and / or preferably the side wall section comprises at least one active cooling element and one passive cooling element to prevent it from heating above a specified temperature, and / or preferably the top wall section comprises at least one active cooling element and one passive cooling element to prevent it from heating above a specified temperature. The side wall section and the top wall section are preferably formed by bell jars, preferably the bell jars are movable relative to the base plate. Preferably, more than 50% (mass) of the side wall section, more than 50% (mass) of the top wall section, and / or more than 50% (mass) of the base plate are made of metal, particularly steel.

[0289] Preferably, a SiC growth substrate has an average circumference of at least 5 cm, preferably at least 7 cm, and very preferably at least 10 cm around a cross-sectional area perpendicular to its longitudinal direction, or multiple SiC growth substrates have an average circumference of at least 5 cm, preferably at least 7 cm, and very preferably at least 10 cm around a cross-sectional area perpendicular to the longitudinal direction of each SiC growth substrate. This solution is advantageous because it has a significantly higher volume deposition rate compared to smaller SiC growth substrates, and therefore allows the same amount of SiC material to be deposited in a shorter time. This solution helps to reduce process time and therefore increase the efficiency of the SiC production reactor. Preferably, a SiC growth substrate comprises or is composed of SiC or C, particularly graphite, or multiple SiC growth substrates comprise or are composed of SiC or C, particularly graphite. The shape of the cross-section perpendicular to the longitudinal direction of the SiC growth substrate is different from a circular shape, 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, at least in each section. The ratio U / A between the cross-sectional area A and the perimeter U around the cross-section 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 of at least one carbon ribbon, particularly a graphite ribbon, the at least one carbon ribbon having 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 a plurality of SiC growth substrates is formed of at least one carbon ribbon, particularly a graphite ribbon, the at least one carbon ribbon for each SiC growth substrate having a first ribbon end and a second ribbon end, the first ribbon end being coupled to a first metal electrode of each SiC growth substrate and the second ribbon end being coupled to a second metal electrode of each SiC growth substrate. Carbon ribbons, particularly graphite ribbons, preferably contain 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 first rod ends coupled to the same first metal electrode, and all second rod ends 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 first rod ends coupled to the same first metal electrode of each SiC growth substrate, and all second rod ends coupled to the same second metal electrode of each SiC growth substrate. Preferably, the rods of the SiC growth substrate are in contact with each other or 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 a first metal electrode, and the second metal rod end being coupled to a 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 a first metal electrode of the respective SiC growth substrate, and the second metal rod end being coupled to a second metal electrode of the respective SiC growth substrate. The metal rod is preferably provided with 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 between 2 μm and 5 mm, particularly between 100 μm and 1 mm, or less than 500 μm.

[0290] The objectives mentioned above are also addressed by a SiC production facility. This SiC production facility comprises at least a plurality of SiC production reactors, in particular a SiC production reactor according to the present invention, each SiC production reactor comprising at least a processing chamber, a gas inlet unit for supplying one or more feed media into the processing chamber, a SiC growth substrate disposed inside the processing chamber, a first power connection and a second power connection between which the SiC growth substrate is coupled for heating the SiC growth substrate by resistance heating, preferably using internal resistance heating, and a gas outlet unit for outputting aeration gas.

[0291] The SiC production facility also preferably includes a vent gas recirculation unit, which is fluidly connected to the gas outlet of the SiC production reactor and includes a separation unit for separating the vent gas into a first liquid phase fluid and a second gas phase fluid.

[0292] The objectives mentioned above are also addressed by a PVT source material production method for producing PVT source materials, particularly polymorphic 3C SiC, using a SiC production reactor 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, wherein a gas outlet unit for outputting a vent gas from the processing chamber and a vent gas recirculation unit are provided, the vent gas recirculation unit being connected to the gas outlet unit and comprising at least one separation unit for separating the vent gas into a first fluid and a second fluid, and further separating the first fluid into at least two parts, namely a chlorosilane mixture and a mixture of HCl, H2 and at least one C-containing molecule, or alternatively, at least three parts, namely a chlorosilane mixture and HCl, The first storage and / or conduction element is connected to yet another separation unit for separating a mixture of H2 and at least one C-containing molecule, and the first storage and / or conduction element is connected to yet another separation unit, and the yet another separation unit is coupled to the storage and / or conduction element for the chlorosilane mixture, preferably a storage and / or conduction element for HCl, and preferably a storage and / or conduction element for H2 and C, and the storage and / or conduction element for the chlorosilane mixture forms a section of a chlorosilane mixture mass flux path for conducting the chlorosilane mixture into the inside of the processing chamber, A step of supplying a chlorosilane mixture to the inside of a processing chamber through a chlorosilane mixture mass flux path in order to provide at least one portion of the source medium, The process involves electrically activating the plurality of SiC growth substrates, which are arranged in a processing chamber, preferably a plurality of SiC growth substrates, each of which has a first power connection and a second power connection, the first power connection being a first metal electrode, the second power connection being a second metal electrode, and preferably the first and second metal electrodes being isolated from the reaction space, heating them to a temperature in the range of 1300°C to 2000°C, and setting a deposition rate particularly higher than 200 μm / h in order to output Si and C from the source medium and to deposit the extracted Si and C onto the SiC growth substrate as SiC, particularly polycrystalline SiC. It is equipped with.

[0293] A further preferred step is to measure the Si mass flux of the chlorosilane mixture, which is performed by a Si mass flux measuring unit provided as part of the chlorosilane mixture mass flux path before the processing chamber, particularly before the mixing device. Another preferred step of the method is to control the supply of the chlorosilane mixture to the mixing device depending on the output of the Si mass flux measuring unit. Another preferred step is to conduct a second fluid comprising H2 and C into the processing chamber, which is flowed into the processing chamber through second storage and / or conduction elements forming a section of the H2 and C mass flux path. Another preferred step is to measure the C mass flux, which is performed by a C mass flux measuring unit provided as part of the H2 and C mass flux path before the processing chamber, particularly before the mixing device. Another preferred step of the method is to control the step of supplying the second fluid depending on the output of the C mass flux measuring unit. Another preferred step is to measure the Si mass flux of the chlorosilane mixture, which is performed by a Si mass flux measuring unit provided as part of the chlorosilane mixture mass flux path before the processing chamber, particularly before the mixing device. Another preferred step is to conduct a second fluid comprising H2 and C into the processing chamber, which is flowed into the processing chamber through second storage and / or conduction elements forming a section of the H2 and C mass flux path. Another preferred step is to measure the C mass flux, which is performed by a C mass flux measuring unit provided as part of the H2 and C mass flux path before the processing chamber, particularly before the mixing device. Another preferred step is to control the supply of the chlorosilane mixture to the mixing device depending on the output of the Si mass flux measuring unit, and furthermore, another preferred step is to control the step of giving a second degree of Kah depending on the output of the C mass flux measuring unit. Preferably, the processing chamber is surrounded by at least a base plate, a side wall section, and an upper wall section.Preferably, more than 50% (by mass) of the side wall sections, more than 50% (by mass) of the top wall sections, and more than 50% (by mass) of the base plate are made of metal, particularly steel. Preferably, the base plate is provided with at least one cooling element to prevent it from heating above a specified temperature, and / or the side wall sections are provided with at least one cooling element to prevent them from heating above a specified temperature, and / or the top wall section is provided with at least one cooling element to prevent it from heating above a specified temperature. Preferably, a base plate sensor unit, a side wall section sensor unit, and / or a top wall section sensor unit are provided for detecting the temperature of the base plate, the side wall sections, and / or the top wall sections 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, and further preferably, a fluid forwarding unit is provided for forwarding the cooling fluid through a fluid guide unit. Preferably, the fluid forwarding unit is configured to operate in reliance 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, and / or a cooling fluid temperature sensor. Preferably, the step of supplying a source medium to the inside of the processing chamber further includes introducing at least a first feeding medium, particularly a first source gas, comprising Si and having a purity of at least 99.9999% (ppm by weight) excluding substances B, Al, P, Ti, V, Fe, and Ni, into the inside of the processing chamber; introducing at least a second feeding medium, particularly a second source gas, comprising C, particularly 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, and Ni, into the inside of the processing chamber; and introducing a transport gas, particularly a purity of at least 99.9999% (ppm by weight) excluding substances B, Al, P, Ti, V, Fe, and Ni.Alternatively, the step of supplying the source medium to the inside of the processing chamber comprises introducing a single feeding medium, particularly a source gas, into the inside of the processing chamber, which comprises Si and C, especially SiCl3(CH3), and has a purity of at least 99.9999% (ppm by weight) excluding substances B, Al, P, Ti, V, Fe, and Ni; and introducing a transport gas having a purity of at least 99.9999% (ppm by weight) excluding substances B, Al, P, Ti, V, Fe, and Ni.

[0294] A mixture of a first source gas providing Si and a second source gas providing C is placed inside the processing chamber on a 1cm SiC growth surface. 2 Another preferred step is to set a pressure higher than 1 bar inside the processing chamber by introducing a predetermined amount of the mixture, which is between 0.32 g per hour per 1 cm² of SiC growth surface and 10 g per hour per 1 cm² of SiC growth surface. 2 Amount of one or more Si and C-containing source gases between 10 g per hour (g / (h cm) 2 The alternative step involves introducing a predetermined amount of [a specific substance] to set a pressure higher than 1 bar inside the processing chamber.

[0295] Preferably, the SiC growth substrate has an average circumference of at least 5 cm around a cross-sectional area perpendicular to its longitudinal direction, or, if there are multiple SiC growth substrates, each SiC growth substrate has an average circumference of at least 5 cm around a cross-sectional area perpendicular to the longitudinal direction of each SiC growth substrate.

[0296] Preferably, the SiC deposited on the SiC growth substrate has an impurity of substance N lower than 10 ppm (by weight) and an impurity of at least one, preferably a plurality, very preferably most, or most preferably all 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 an impurity of each 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). Instead of this, the SiC deposited on the SiC growth substrate 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).

[0297] This method preferably further comprises a step of deagglomerating the SiC solid into SiC particles, and the SiC particles are deagglomerated 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 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).

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

[0301] Preferably, the SiC solid forms an interface at a predetermined distance from the central axis of the SiC solid, and the SiC solid forms an outer surface. The outer surface and the interface are formed at a distance from each other, this distance extending perpendicular to the central axis, and the average distance between the outer surface and the interface is greater than the average distance between the interface and the central axis. The average distance between the outer surface and the interface is calculated using the following formula: (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 as 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 larger than 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 a cross section perpendicular to the central axis.

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

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

[0304] Preferably, the shape of the cross-section perpendicular 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 axial direction, very preferably along more than 90% of the extension of the SiC solid in the central axial direction, and most preferably along 100% of the extension of the SiC solid in the central axial direction.

[0305] The ratio U / A between the cross-sectional area A and the surrounding area U 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 interface preferably surrounds a solid core member. Preferably the core member comprises or is composed of graphite. Alternatively, the core member is composed of or comprises SiC. Preferably, the SiC of the core member and the SiC between the outer surface and the interface 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 interface 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 within the CDV reactor, it is possible to alternatively refer to this material as "material produced within the CDV reactor" or simply "SiC material."

[0307] The objectives mentioned above are also addressed by the PVT source material production method for producing 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 the general formula SiH 4-y X y(A step of introducing at least a first feeding medium, particularly a first source gas, into the processing chamber, comprising Si according to X=[Cl, F, Br, J] and y=[0...4] and having a purity of at least 99.9999% (ppm by weight) excluding substances B, Al, P, Ti, V, Fe, and Ni; and C, particularly natural gas, methane, ethane, propane, butane, and / or acetylene, having a purity of at least 99.9999% excluding substances B, Al, P, Ti, V, Fe, and Ni) The process comprises the steps of introducing at least a second feeding medium, particularly a second source gas, into the processing chamber, and introducing a transport gas having a purity of at least 99.9999% (ppm by weight) excluding substances B, Al, P, Ti, V, Fe, and Ni, or introducing a single feeding medium, particularly a source gas, comprising Si and C, particularly SiCl3(CH3), having a purity of at least 99.9999% (ppm by weight) excluding substances B, Al, P, Ti, V, Fe, and Ni, into the processing chamber. The above-mentioned providing step comprises the step of introducing into the side and introducing a transport gas having a purity of at least 99.9999% (ppm by weight) excluding substances B, Al, P, Ti, V, Fe, and Ni; the step of electrically activating the SiC growth substrate, preferably a plurality of SiC growth substrates, arranged in a processing chamber, wherein each SiC growth substrate is provided with a first power connection part and a second power connection part, the first power connection part being a first metal electrode and the second power connection part being a second metal electrode, and preferably the first and second metal electrodes electrically activating the SiC growth substrate, which is isolated from the reaction space inside the processing chamber, and heating it to a temperature in the range of 1300°C to 2000°C; and the step of setting a deposition rate particularly higher than 200 μm / h in order to output Si and C from the source medium and to deposit the extracted Si and C onto the SiC growth substrate as SiC, particularly polycrystalline SiC, thereby forming a SiC solid.

[0308] Another preferred step of this method is to set a pressure higher than 1 bar inside the processing chamber. Another preferred step of this method is to introduce a mixture of a first source gas that provides Si and a second source gas that provides C into the processing chamber in a predetermined amount, which is between 0.32 g per hour per 1 cm² of SiC growth surface and 10 g per hour per 1 cm² of SiC growth surface. Another preferred step of this method is to introduce a Si and C-containing source gas into the processing chamber in a predetermined amount, which is between 0.32 g per hour per 1 cm² of SiC growth surface and 10 g per hour per 1 cm² of SiC growth surface. Another preferred step of this method is to set a pressure higher than 1 bar inside the processing chamber by introducing a mixture of a first source gas that provides Si and a second source gas that provides C into the processing chamber in a predetermined amount, which is between 0.32 g per hour per 1 cm² of SiC growth surface and 10 g per hour per 1 cm² of SiC growth surface. Another preferred step of this method is to set a pressure higher than 1 bar inside the processing chamber by introducing a predetermined amount of Si and C-containing source gas into the processing chamber, which is between 0.32 g per hour per 1 cm² of SiC growth surface and 10 g per hour per 1 cm² of SiC growth surface. Another preferred step of this method is to increase the electroactivation 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. 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] Another preferred step of this method is to deposit Si and C at a set deposition rate for a longer period than 5 hours, particularly 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.

[0310] Another preferred step of this method is to grow the SiC solid to a weight greater than 5 kg, particularly greater than 25 kg or up to 25 kg, preferably greater than 50 kg or up to 50 kg, very preferably greater than 200 kg or up to 200 kg, most preferably greater than 500 kg or up to 500 kg, during the deposition of C and Si, and / or to a thickness greater than 5 cm, particularly greater than 7 cm or up to 7 cm, preferably greater than 10 cm or up to 10 cm, preferably greater than 15 cm or up to 15 cm, very preferably greater than 20 cm or up to 20 cm, most preferably greater than 50 cm or up to 50 cm.

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

[0312] Preferably, the maximum amount of the feeding medium supply per minute is up to 30% (by mass), up to 20% (by mass), up to 10% (by mass), up to 5% (by mass), or up to 3% (by mass) higher than the minimum amount of the feeding medium supply.

[0313] The processing chamber is surrounded by at least a base plate, a side wall section, and an upper wall section, preferably the base plate having at least one cooling element, particularly a base cooling element, to prevent it from heating above a specified temperature, and / or preferably the side wall section having at least one cooling element, particularly a bell jar cooling element, to prevent it from heating above a specified temperature, and / or preferably the upper wall section having at least one cooling element, particularly a bell jar cooling element, to prevent it from heating above a specified temperature. The cooling elements are preferably active cooling elements. Preferably the base plate, the side wall section, and / or the upper wall section are provided with a cooling fluid guide unit for guiding a cooling fluid, the cooling fluid guide unit being 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, side wall sections, and / or upper wall sections 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, and further preferably, a fluid forwarding unit is provided for forwarding the cooling fluid through a fluid guide 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, preferably water comprising at least one additive, in particular a rust inhibitor and / or an antifouling agent (biocide). The cooling element may be a passive cooling element in addition to or instead of the above. Preferably, the cooling element is at least partially formed by the polished steel surfaces of the base plate, side wall sections, and / or upper wall sections. The cooling element is preferably a coating, which is formed on the polished steel surface and configured to reflect heat.Preferably, the coating is a metallic coating, or comprises a coating of metal, particularly silver, gold, chromium, or an alloy, particularly a CuNi alloy. The emissivity of the polished steel surface and / or coating is preferably less than εe0.3, particularly 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 heating above a specified temperature, and / or preferably, the side wall section comprises at least one active cooling element and one passive cooling element to prevent it from heating above a specified temperature, and / or preferably, the top wall section comprises at least one active cooling element and one passive cooling element to prevent it from heating above a specified temperature. The side wall section and the top wall section are preferably formed by bell jars, which are preferably movable relative to the base plate. Preferably, more than 50% (by mass) of the side wall sections, more than 50% (by mass) of the top wall sections, and / or more than 50% (by mass) of the base plate are made of metal, particularly steel.

[0314] Preferably, a gas outlet unit for outputting a vent gas and a vent gas recirculation unit are provided, preferably operated according to the method described above. The vent gas recirculation unit is connected to the gas outlet unit and comprises at least one 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, and a first storage element and / or conduction element for storing or conducting the first fluid being part of or coupled to the separation unit, and a second storage element and / or conduction element for storing or conducting the second fluid being part of or coupled to the separation unit. Preferably, the step of supplying a source medium to the inside of the processing chamber comprises a step of supplying the first fluid from the vent gas recirculation unit to the inside of the processing chamber, the first fluid comprising at least a mixture of chlorosilanes. Preferably, the aeration gas recirculation unit comprises a further separation unit for separating a first fluid into at least two parts, namely a chlorosilane mixture and a mixture of HCl, H2 and at least one C-containing molecule, preferably at least three parts, namely a chlorosilane mixture and a mixture of HCl, H2 and at least one C-containing molecule, wherein the first storage element and / or conduction element connects the separation unit to yet another separation unit, which is coupled with 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, the storage element and / or conduction element for the chlorosilane mixture forming a section of a chlorosilane mixture mass flux path for conducting the chlorosilane mixture into the processing chamber, and a Si mass flux measuring unit for measuring the amount of Si in the chlorosilane mixture is provided as yet another Si feed medium source, preferably providing yet 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 circumference of at least 5 cm around a cross-sectional area perpendicular to its longitudinal direction, or, if there are multiple SiC growth substrates, each SiC growth substrate has an average circumference of at least 5 cm around a cross-sectional area perpendicular to the longitudinal direction of each SiC growth substrate.

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

[0317] The objectives mentioned above are also addressed by a PVT source material consisting of SiC particles having an average length longer than 100 μm and containing impurities of substance N at a level lower than 10 ppm (by weight), and impurities of each of the substances B, Al, P, Ti, V, Fe, and Ni at a level 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 possess particularly advantageous properties as PVT source materials.

[0319] Preferably, the SiC particles have impurities of substance N at a rate of less than 2 ppm (weight) and impurities of each of substances B, Al, P, Ti, V, Fe, and Ni at a rate of less than 100 ppb (weight), and very preferably, impurities of substance Ti at a rate of less than 10 ppb (weight). In addition to or instead of this, preferably, the SiC particles have impurities of substance N at a rate of less than 10 ppm (weight) and impurities of all of the metals Ti, V, Fe, and Ni combined at a rate of less than 1000 ppb (weight), and especially less than 500 ppb (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 according to ISO697, and the tap density is measured according to 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(A step of introducing at least a first feeding medium, particularly a first source gas, into the processing chamber, comprising Si according to X=[Cl, F, Br, J] and y=[0...4] and having a purity of at least 99.9999% (ppm by weight) excluding substances B, Al, P, Ti, V, Fe, and Ni; and a step of introducing at least a second feeding medium, particularly a second source gas, into the processing chamber, comprising C, particularly 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, and Ni.) The process comprises the steps of introducing a transport gas having a purity excluding at least 99.9999% (by weight ppm) of substances B, Al, P, Ti, V, Fe, and Ni, or introducing a single feeding medium, particularly a source gas, comprising Si and C, especially SiCl3(CH3), and having a purity excluding at least 99.9999% (by weight ppm) of substances B, Al, P, Ti, V, Fe, and Ni, into the processing chamber, and introducing a transport gas having a purity excluding at least 99.9999% (by weight ppm) of substances B, Al, P, Ti, V, Fe, and Ni. The process includes the steps of providing the above-mentioned material, electrically activating at least one SiC growth substrate, preferably a plurality of SiC growth substrates, placed in a processing chamber and heating them to a temperature in the range of 1300°C to 2000°C, setting a deposition rate particularly higher than 200 μm / h in order to extract Si and C from the source medium and deposit the extracted Si and C onto the SiC growth substrate as SiC, particularly polycrystalline SiC, thereby forming a SiC solid, and deaggregating the SiC solid into SiC particles having an average length longer than 100 μm. The process comprises the steps of: Preferably, the PVT source material is polymorphic 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 have excess carbon less than 30% (mass) of Si to C, preferably less than 20% (mass) of excess carbon, very preferably less than 10% (mass) of excess carbon, or most preferably less than 5% (mass) of excess carbon compared to the ideal stoichiometric ratio of Si to C.Preferably, the SiC particles have excess Si of less than 30% (by mass) compared to the ideal stoichiometric ratio of Si to C, preferably less than 20% (by mass), very preferably less than 10% (by mass), or most preferably less than 5% (by mass).

[0322] Since the PVT source material is produced within the CDV reactor, it is possible to alternatively refer to this material as "material produced within the CDV reactor" or simply "SiC material."

[0323] The objectives mentioned above are also addressed by a PVT source material lot, which comprises at least 1 kg of the PVT source material according to the present invention.

[0324] The objectives mentioned above are also addressed by the PVT source material production method for producing PVT source material according to the present invention. Preferably, the PVT source material production method is a step of providing a source medium inside a processing chamber, in particular a general formula SiH 4-y X y(A step of introducing at least a first feeding medium, in particular a first source gas, into a processing chamber (856), comprising Si according to X=[Cl, F, Br, J] and y=[0...4] and having a purity of at least 99.9999% (ppm by weight) excluding substances B, Al, P, Ti, V, Fe, and Ni; and at least a second feeding medium, in particular a second, 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, and Ni) The process comprises the steps of introducing a source gas into the processing chamber and introducing a transport gas having a purity excluding at least 99.9999% (ppm by weight) of substances B, Al, P, Ti, V, Fe, and Ni, or introducing a single feeding medium comprising Si and C, particularly SiCl3(CH3), having a purity excluding at least 99.99999% (ppm by weight) of substances B, Al, P, Ti, V, Fe, and Ni, particularly the source gas into the processing chamber (856), and introducing at least 99.99999% (ppm by weight) of substances B, Al The above-mentioned step of providing a transport gas having a purity excluding P, Ti, V, Fe, and Ni, and at least one SiC growth substrate, preferably a plurality of SiC growth substrates, arranged in a processing chamber, each SiC growth substrate having a first power connection part and a second power connection part, the first power connection part being a first metal electrode, the second power connection part being a second metal electrode, and the first metal electrode and the second metal electrode electrically activate the SiC growth substrate, which is preferably isolated from the reaction space inside the processing chamber. The method comprises the steps of: heating it to a temperature in the range of 1300°C to 2000°C; setting a deposition rate particularly higher than 200 μm / h in order to extract Si and C from the source medium and deposit the extracted Si and C as SiC, particularly polycrystalline SiC, onto a SiC growth substrate to form a SiC solid; and deaggregating the SiC solid into SiC particles having an average length of longer than 100 μm. This method is beneficial because it can produce SiC material of very high purity on an industrial scale.

[0325] A preferred step of the method is to set a pressure higher than 1 bar inside the processing chamber.

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

[0327] Another preferred step of this method is to increase the electroactivation of at least one SiC growth substrate over time, particularly heating the surface of the deposited SiC to a temperature between 1300°C and 1800°C. Preferably, the deposition rate is set to be higher than 200 μm / h, very preferably higher than 500 μm / h, and most preferably higher than 800 μm / h.

[0328] Another preferred step of this method is to deposit Si and C at a set deposition rate for a longer period than 5 hours, particularly 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.

[0329] Another preferred step of this method is to grow the SiC solid to a weight greater than 5 kg, particularly greater than 25 kg or up to 25 kg, preferably greater than 50 kg or up to 50 kg, very preferably greater than 200 kg or up to 200 kg, most preferably greater than 500 kg or up to 500 kg, during the deposition of C and Si; and to grow the SiC solid to a thickness of at least 5 cm, particularly greater than 7 cm or up to 7 cm, preferably greater than 10 cm or up to 10 cm, preferably greater than 15 cm or up to 15 cm, very preferably greater than 20 cm or up to 20 cm, most preferably greater than 50 cm or up to 50 cm, during the deposition of C and Si.

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

[0331] Preferably, the maximum amount of the feeding medium supply per minute is up to 30% (by mass), up to 20% (by mass), up to 10% (by mass), up to 5% (by mass), or up to 3% (by mass) higher than the minimum amount of the feeding medium supply.

[0332] The processing chamber is surrounded by at least a base plate, a side wall section, and an upper wall section, preferably the base plate having at least one cooling element, particularly a base cooling element, to prevent it from heating above a specified temperature, and / or preferably the side wall section having at least one cooling element, particularly a bell jar cooling element, to prevent it from heating above a specified temperature, and / or preferably the upper wall section having at least one cooling element, particularly a bell jar cooling element, to prevent it from heating above a specified temperature. The cooling elements are preferably active cooling elements. Preferably the base plate, the side wall section, and / or the upper wall section are provided with a cooling fluid guide unit for guiding a cooling fluid, the cooling fluid guide unit being 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, side wall sections, and / or upper wall sections 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, and further preferably, a fluid forwarding unit is provided for forwarding the cooling fluid through a fluid guide 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, preferably water comprising at least one additive, in particular a rust inhibitor and / or an antifouling agent (biocide). The cooling element may be a passive cooling element in addition to or instead of the above. Preferably, the cooling element is at least partially formed by the polished steel surfaces of the base plate, side wall sections, and / or upper wall sections. The cooling element is preferably a coating, which is formed on the polished steel surface and configured to reflect heat.Preferably, the coating is a metallic coating, or comprises a coating of metal, particularly silver, gold, chromium, or an alloy, particularly a CuNi alloy. The emissivity of the polished steel surface and / or coating is preferably less than εe0.3, particularly 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 heating above a specified temperature, and / or preferably, the side wall section comprises at least one active cooling element and one passive cooling element to prevent it from heating above a specified temperature, and / or preferably, the top wall section comprises at least one active cooling element and one passive cooling element to prevent it from heating above a specified temperature. The side wall section and the top wall section are preferably formed by bell jars, which are preferably movable relative to the base plate. Preferably, more than 50% (by mass) of the side wall sections, more than 50% (by mass) of the top wall sections, and / or more than 50% (by mass) of the base plate are made of metal, particularly steel.

[0333] Preferably, a gas outlet unit for outputting a vent gas and a vent gas recirculation unit are provided, preferably operated according to the method described above. The vent gas recirculation unit is connected to the gas outlet unit and comprises at least one 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, and a first storage element and / or conduction element for storing or conducting the first fluid being part of or coupled to the separation unit, and a second storage element and / or conduction element for storing or conducting the second fluid being part of or coupled to the separation unit. Preferably, the step of supplying a source medium to the inside of the processing chamber comprises a step of supplying the first fluid from the vent gas recirculation unit to the inside of the processing chamber, the first fluid comprising at least a mixture of chlorosilanes. Preferably, the aeration gas recirculation unit comprises a further separation unit for separating a first fluid into at least two parts, namely a chlorosilane mixture and a mixture of HCl, H2 and at least one C-containing molecule, preferably at least three parts, namely a chlorosilane mixture and a mixture of HCl, H2 and at least one C-containing molecule, wherein the first storage element and / or conduction element connects the separation unit to yet another separation unit, which is coupled with 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, the storage element and / or conduction element for the chlorosilane mixture forming a section of a chlorosilane mixture mass flux path for conducting the chlorosilane mixture into the processing chamber, and a Si mass flux measuring unit for measuring the amount of Si in the chlorosilane mixture is provided as yet another Si feed medium source, preferably providing yet 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 circumference of at least 5 cm around a cross-sectional area perpendicular to its longitudinal direction, or, if there are multiple SiC growth substrates, each SiC growth substrate has an average circumference of at least 5 cm around a cross-sectional area perpendicular to the longitudinal direction of each SiC growth substrate.

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

[0336] The objectives mentioned above are also addressed by a method for producing 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, particularly a first source gas, particularly SiCl3(CH3), into a processing chamber to generate a source medium comprising Si and C; preferably introducing at least one transport gas comprising H into the processing chamber; electrically activating at least one SiC growth substrate placed in the processing chamber to heat its surface to a temperature in the range of 1300°C to 1800°C; depositing the first type of SiC onto the SiC growth substrate at a deposition rate particularly higher than 200 μm / h, wherein the SiC deposit is preferably polycrystalline SiC; outputting the deposited first type of 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 having an outer surface and an inner surface, and at least one crucible unit comprising a crucible housing located inside the furnace housing, wherein the crucible housing has an outer surface and an inner surface, the inner surface at least partially defining the crucible volume, a receiving space for receiving source material arranged or formed inside the crucible volume, a seed holder unit for holding a defined seed wafer arranged inside the crucible volume, the seed wafer holder holding the seed wafer, and the inner wall of the furnace housing and the outer wall of the crucible housing defining the furnace volume of the crucible unit, and at least one heating unit for heating source material, wherein a receiving space for receiving source material is at least partially located above the heating unit and below the seed holder unit.This method further includes the steps of adding a first type of fragmented SiC to a receiving space or adding one or more solids of the first type of SiC as a source material; sublimating the first type of SiC inside a PVT reactor; and depositing the sublimated SiC as a second type of SiC on a seed wafer. This method is beneficial because both the PVT source material and the SiC crystals are produced in a highly efficient manner and of very high quality.

[0337] Preferably, the step of introducing at least one source gas and at least one transport gas is provided with Si, and in particular the general formula SiH 4-y X y A Si feeding medium source that provides Si gas according to X=[Cl, F, Br, J] and y=[0...4], comprising the steps of introducing at least a first feeding medium, particularly a first source gas, having a purity of at least 99.9999% (weight ppm) excluding substances B, Al, P, Ti, V, Fe, and Ni, into the processing chamber, and introducing at least a second feeding medium, particularly a second source gas, comprising C, particularly natural gas, methane, ethane, propane, butane, and / or acetylene, having a purity of at least 99.9999% excluding substances B, Al, P, Ti, V, Fe, and Ni, into the processing chamber, comprising at least 99.9999% (weight ppm) excluding substances B, Al, P, Ti The process comprises the steps of introducing a transport gas having a purity excluding V, Fe, and Ni. Alternatively, the step of introducing at least one source gas and at least one transport gas preferably comprises the steps of introducing a single feeding medium, particularly a source gas, into the processing chamber, which comprises Si and C, especially SiCl3(CH3), and has a purity of at least 99.9999% (weight ppm) excluding substances B, Al, P, Ti, V, Fe, and Ni, and introducing a transport gas having a purity excluding at least 99.9999% (weight ppm) excluding substances B, Al, P, Ti, V, Fe, and 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 at a level lower than 10 ppm (weight) and impurities of each of substances B, Al, P, Ti, V, Fe, and Ni at a level lower than 1000 ppb (weight), particularly lower than 500 ppb (weight). Very preferably, they have impurities of substance N at a level lower than 2 ppm (weight) and impurities of each of substances B, Al, P, Ti, V, Fe, and Ni at a level lower than 100 ppb (weight), or impurities of substance Ti at a level lower than 10 ppb (weight). Alternatively, the SiC particles have impurities of substance N at a level lower than 10 ppm (weight) and impurities of all of the metals Ti, V, Fe, and Ni combined at a level lower than 1000 ppb (weight), particularly lower than 500 ppb (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 SiC particles is preferably higher than 1.6 g / cm³, and very preferably higher than 1.8 g / cm³.

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

[0340] Another preferred step of this method is to set a pressure higher than 1 bar inside the processing chamber.

[0341] Another preferred step of this method is to introduce a mixture of a first source gas that provides Si and a second source gas that provides C into the processing chamber in a predetermined amount, which is between 0.32 g per hour per 1 cm² of SiC growth surface and 10 g per hour per 1 cm² of SiC growth surface. Alternatively, another preferred step of this method is to introduce a Si and C-containing source gas into the processing chamber in a predetermined amount, which is between 0.32 g per hour per 1 cm² of SiC growth surface and 10 g per hour per 1 cm² of SiC growth surface. Alternatively, another preferred step of this method is to set a pressure higher than 1 bar inside the processing chamber by introducing a mixture of a first source gas that provides Si and a second source gas that provides C into the processing chamber in a predetermined amount, which is between 0.32 g per hour per 1 cm² of SiC growth surface and 10 g per hour per 1 cm² of 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 a Si and C-containing source gas into the processing chamber at a predetermined amount, which is between 0.32 g per hour per cm² of SiC growth surface and 10 g per hour per cm² of SiC growth surface. Preferably, the processing chamber is surrounded by a base plate, side wall sections, and an upper wall section, and more than 50% of the side wall sections, more than 50% of the upper wall sections, 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 are provided for detecting the temperature of the base plate, the side wall sections, and / or the upper wall sections 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, and further preferably, a fluid progressive unit is provided for progressively moving the cooling fluid through a fluid guide unit. Preferably, the fluid forwarding unit is configured to operate in reliance 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, and / or a cooling fluid temperature sensor.Preferably, the SiC growth substrate has an average perimeter of at least 5 cm around a cross-sectional area perpendicular to its longitudinal direction, or, if there are multiple SiC growth substrates, each SiC growth substrate has an average perimeter of at least 5 cm around a cross-sectional area perpendicular to the longitudinal direction of each SiC growth substrate. The SiC deposited on the SiC growth substrate preferably has impurities of substance N at a rate of less than 10 ppm (weight) and impurities of each of substances B, Al, P, Ti, V, Fe, and Ni at a rate of less than 1000 ppb (weight), particularly less than 500 ppb (weight), and very preferably has impurities of substance N at a rate of less than 2 ppm (weight) and impurities of each of substances B, Al, P, Ti, V, Fe, and Ni at a rate of less than 100 ppb (weight) or impurities of substance Ti at a rate of less than 10 ppb (weight). Alternatively, the SiC deposited on the SiC growth substrate has impurities of substance N at a rate of less than 10 ppm (weight) and impurities of the total of all of the metals Ti, V, Fe, and Ni at a rate of less than 1000 ppb (weight), particularly less than 500 ppb (weight). Preferably, a gas outlet unit and a vent gas recirculation unit for outputting a vent gas are provided as units operated according to part of the method of the present invention, the vent gas recirculation unit being connected to the gas outlet unit and comprising at least one 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, a first storage element and / or conduction element for storing or conducting the first fluid being part of or coupled to the separation unit, and a second storage element and / or conduction element for storing or conducting the second fluid being part of or coupled to the separation unit. Furthermore, the method preferably comprises a step of supplying a source medium to the inside of the processing chamber, preferably a step of supplying a first fluid from a vent gas recirculation unit to the inside of the processing chamber, the first fluid comprising at least a chlorosilane mixture. Preferably, the gas introduced into the CVD reactor comprises one, more, or all of the following substances in a lower percentage (ppm by weight) than 99.9999%: B (boron), Al (aluminum), P (phosphorus), Ti (titanium), V (vanadium), Fe (iron), Ni (nickel).Preferably, a crucible gas flow unit is provided to bring a gas flow into the crucible volume, 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 positioned inside the crucible housing, the growth guide forming a growth-guide-gas-path-section-boundary for guiding the gas flow toward a seed holder unit, and the growth guide and seed holder unit together form a gas flow path. Preferably, the method comprises the steps of establishing a gas flow through the crucible volume by conducting at least a transport gas into the crucible volume through a crucible gas inlet tube and conducting at least this transport gas out of the crucible volume through a crucible gas outlet tube; establishing a predetermined gas flow velocity through the gas channel by controlling the gas flow entering the crucible volume through the crucible gas inlet tube; and / or establishing a predetermined gas flow velocity through the gas channel by controlling the gas flow leaving the crucible volume through a crucible gas outlet tube, wherein the predetermined gas flow velocity is between 1 cm / s and 10 cm / s, preferably between 2 cm / s and 6 cm / s.

[0342] Preferably, the receiving space is located between the crucible gas inlet and the seed holder unit. Preferably, the method comprises a step of conducting the gas flow around and / or through the receiving space.

[0343] Preferably, in order to take in at least Si2C sublimation vapor, SiC2 sublimation vapor, and Si sublimation vapor, a filter unit is positioned inside the crucible volume between a seed holder unit and a crucible gas outlet tube, the filter unit forming a filter unit gas flow path from the filter input surface to the filter output surface, the filter gas flow path being part of the gas flow path between the crucible gas inlet tube and the crucible gas outlet tube, the filter unit preferably having a height S1, and the filter unit gas flow path penetrating the filter unit preferably having a length S2, where S2 is at least twice, and particularly ten times, longer than S1. Preferably, the method comprises the step of guiding the gas from the gas flow path to the filter input surface, from the filter input surface through the filter unit to the filter output surface, and further from the filter output surface to the crucible gas outlet tube.

[0344] Preferably, a pressure unit is provided inside the crucible volume for setting the crucible volume pressure, and the pressure unit is configured to produce a crucible volume pressure that is higher than 2666.45 Pa, preferably higher than 5000 Pa, or in the range between 2666.45 Pa and 50000.00 Pa. Preferably, the method comprises a step of generating a crucible volume pressure 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.

[0345] Preferably, the PVT reactor comprises a crucible gas flow unit, the crucible gas flow unit comprising a crucible gas inlet tube for conducting gas into the crucible volume, the crucible gas inlet tube being positioned vertically below the receiving space. Preferably, the method comprises a step of conducting gas into the crucible housing through the crucible gas flow unit.

[0346] The objectives mentioned above are also addressed by a system for the production of SiC, comprising a CVD reactor for the production of a first type of SiC as a PVT source material. The CVD reactor comprises at least a processing chamber surrounded by a base plate, a side wall section and an upper wall section, and a gas inlet unit for feeding one or more feed media into the reaction space of the processing chamber to generate a source medium, wherein the feed media source is coupled with at least one feed media source, the Si and C feed media source provides at least Si and C, in particular SiCl3(CH3), and the transport gas feed media source provides a transport gas, in particular H2, or is coupled with at least two feed media sources, the Si feed media source provides at least Si, in particular SiH 4-y X yThe gas inlet unit provides a Si gas according to X=[Cl, F, Br, J] and y=[0...4], the C feeding medium source provides at least C, in particular natural gas, methane, ethane, propane, butane, and / or acetylene, and the transport gas medium source provides a transport gas, in particular H2, and one or more, in particular more than 3, 4, 6, 8, 16, 32, or 64, up to 128 or up to 256 SiC growth substrates arranged inside the processing chamber for depositing SiC, each SiC growth substrate having a first power connection The SiC growth substrate comprises a first power connection section and a second power connection section, the first power connection section being a first metal electrode and the second power connection section being a second metal electrode, and the SiC growth substrate is coupled between at least one first metal electrode and at least one second metal electrode to heat the outer surface of the SiC growth substrate or the surface of the deposited SiC to a temperature between 1300°C and 1800°C, particularly using resistance heating, preferably internal resistance heating, so that the first type of SiC is deposited on each SiC growth substrate, and the first type of deposited SiC from the CVD reactor is directed toward the generation of the second type of SiC The PVT reactor comprises a furnace unit having a furnace housing having an outer surface and an inner surface, and at least one crucible unit comprising a crucible housing located inside the furnace housing, the crucible housing having an outer surface and an inner surface, the inner surface at least partially defining the crucible volume, a receiving space located or formed inside the crucible volume for receiving source material in the form of a first type of SiC from the CVD reactor, a seed holder unit located inside the crucible volume for holding a defined seed wafer, the seed wafer holder holding the seed wafer, and the inner wall of the furnace housing and the outer wall of the crucible housing defining the furnace volume, and at least one heating unit for heating source material in the form of a first type of SiC from the CVD reactor, the heating unit comprising a receiving space located at least partially above the heating unit and below the seed holder unit for receiving source material in the form of a first type of SiC from the CVD reactor.Furthermore, the system brings about the steps of adding a first type of SiC from a CVD reactor as a source material into the receiving space, sublimating the first type of SiC inside the PVT reactor, and depositing the sublimated SiC as a second type of SiC on a seed wafer. Preferably, the first and second metal electrodes are isolated from the reaction space inside the processing chamber.

[0347] The objectives mentioned above are also addressed by a SiC generation reactor, particularly for the production of UPSiC as a PVT source material. Preferably, this SiC generation reactor comprises at least a processing chamber surrounded by a base plate, a side wall section, and an upper wall section, and a gas inlet unit for supplying one or more feed media into the reaction space of the processing chamber to generate a source medium, wherein the gas inlet unit is coupled to at least one feed media source, the Si and C feed media source providing at least Si and C, particularly SiCl3(CH3), and the transport gas feed media source providing a transport gas, particularly H2. Alternatively, the gas inlet unit may be coupled to at least two feed media sources, the Si feed media source providing at least Si, particularly SiH 4-y X yThe SiC production reactor provides a Si gas acc...

Claims

1. A method for producing at least one SiC crystal, A step of providing a CVD reactor (850) and a vent gas recirculation unit for the production of a first type of SiC, wherein the CVD reactor (850) comprises a processing chamber (856) and a gas outlet unit for outputting vent gas from the processing chamber (856), the vent gas recirculation unit is connected to the gas outlet unit, the vent gas recirculation unit comprises at least a separation unit for separating the vent gas into a first fluid and a second fluid, the separation unit being a low-temperature distillation column, the first fluid being a liquid containing a mixture of at least chlorosilanes, the second fluid being a gas containing H2 and at least one C-containing molecule, a first storage and / or conduction element for storing or conducting the first fluid being part of or coupled to the separation unit, and a second storage and / or conduction element for storing or conducting the second fluid being part of or coupled to the separation unit, A step of introducing one type of source gas into the processing chamber (856) as a source medium, or a step of introducing multiple source gases into the processing chamber (856) to generate a source medium containing Si and C, The steps include introducing at least one transport gas into the processing chamber (856), A step of electrically activating at least one SiC growth substrate (857) placed in the processing chamber (856) in order to heat the SiC growth substrate (857), The surface of the SiC growth substrate (857) is heated to a temperature within the range of 1300°C to 1800°C. The aforementioned step of electrically activating, The steps include depositing the first type of SiC onto the SiC growth substrate (857), The first step of removing the deposited SiC of the first type from the CVD reactor (850), A step of transforming the extracted SiC into the first type of fragmented SiC or into one or more solid objects of the first type of SiC, The step of providing a PVT reactor (100) for the production of a second type of SiC, The PVT reactor (100) 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), The crucible unit (106) is positioned inside the furnace housing (108), The crucible unit (106) comprises a crucible housing (110), The crucible housing (110) has an outer surface (112) and an inner surface (114) that at least partially defines the crucible volume (116), A receiving space (118) for receiving the source material (120) is located or formed inside the crucible volume (116). A seed holder unit (122) for holding a designated seed wafer (18) is positioned inside the crucible volume (116). The inner wall (240) of the furnace housing and the outer wall (112) of the crucible housing determine the furnace volume (104). The crucible unit (106) and, At least one heating unit (124) for heating the aforementioned source material (120), The receiving space (118) for receiving the source material (120) is at least partially located above the heating unit (124) and below the seed holder unit (122). The heating unit (124) and, The stage of having, The steps include adding the first type of fragmented SiC into the receiving space (118) or adding one or more solids of the first type of SiC as a source material (120), The first step of sublimating the SiC of the first type inside the PVT reactor (100), The steps include depositing the sublimated SiC as the second type of SiC onto the seed wafer (18), A method characterized by comprising:

2. The fragmented SiC represents SiC particles (920) having an average length of at least 100 μm. The method according to feature 1.

3. The SiC particles (920) have impurities of substance N at a level lower than 10 ppm (by weight), and impurities of each of the substances B, Al, P, Ti, V, Fe, and Ni at a level lower than 1000 ppb (by weight). The method according to feature 2.

4. The SiC particles (920) have impurities of substance N at a level lower than 2 ppm (by weight), and impurities of each of the substances B, Al, P, Ti, V, Fe, and Ni at a level lower than 100 ppb (by weight). The method according to feature 3.

5. The SiC particles (920) have an impurity of substance Ti at a level lower than 10 ppb (by weight). The method according to feature 4.

6. The SiC particles contain impurities of substance N at a level lower than 10 ppm (by weight), and impurities of all metals Ti, V, Fe, and Ni combined at a level lower than 1000 ppb (by weight). The method according to feature 3.

7. The apparent density of the SiC particles (920) is higher than 1.4 g / cm³. The method according to any one of claims 4 to 6, characterized by...

8. The apparent density of the SiC particles (920) is higher than 1.6 g / cm³. The method according to feature 7.

9. The tap density of the SiC particles (920) is higher than 1.6 g / cm³. The method according to claim 7 or 8, characterized by the features described herein.

10. The tap density of the SiC particles (920) is higher than 1.8 g / cm³. The method according to feature 9.

11. Each of the one or more solid materials of SiC is A mass heavier than 0.3 kg, At least 1 cm thick, A length longer than 10 cm, Impurities of substance N at a level lower than 10 ppm (by weight), and impurities of each of substances B, Al, P, Ti, V, Fe, and Ni at a level lower than 1000 ppb (by weight), Characterized by, The method according to feature 1.

12. Each of the one or more solid particles of SiC has an impurity of substance N at a level lower than 2 ppm (by weight) and an impurity of each of substances B, Al, P, Ti, V, Fe, and Ni at a level lower than 100 ppb (by weight). The method according to 11, characterized by the features described above.

13. Each of the one or more solid particles of SiC has an impurity of substance Ti at a level lower than 10 ppb (by weight). The method according to 12, characterized by the features described above.

14. Each of the one or more solid particles of SiC has an impurity of substance N at a level lower than 10 ppm (by weight) and an impurity of all of the metals Ti, V, Fe, and Ni combined at a level lower than 1000 ppb (by weight). The method according to 11, characterized by the features described above.

15. Steps include setting a pressure higher than 1 bar inside the processing chamber (856), A method according to any one of claims 7 to 10 or any one of claims 13 to 14, characterized by the above.

16. The processing chamber (856) is surrounded by a base plate (862), a side wall section (864a), and an upper wall section (864b), wherein more than 50% (mass) of the side wall section, more than 50% (mass) of the upper wall section, and more than 50% (mass) of the base plate are made of metal. The method according to the present invention, characterized by the present invention.

17. A base plate and / or side wall section sensor and / or top wall section sensor unit is provided for detecting the temperature of the base plate and / or side wall section and / or top 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 forwarding unit is provided for forwarding the cooling fluid through a fluid guide unit. The method according to 16, characterized by...

18. The fluid forwarding unit is configured to operate in accordance with the temperature signal or temperature data provided by the base plate and / or side wall section and / or top wall section sensor unit and / or cooling fluid temperature sensor. The method according to feature 17.

19. The SiC deposited on the SiC growth substrate (857) has an impurity of substance N at a level lower than 10 ppm (by weight), and an impurity of each of the substances B, Al, P, Ti, V, Fe, and Ni at a level lower than 1000 ppb (by weight). The method according to any one of claims 13 to 18, characterized by...

20. The SiC deposited on the SiC growth substrate (857) has an impurity of substance N at a level lower than 2 ppm (by weight), and an impurity of each of the substances B, Al, P, Ti, V, Fe, and Ni at a level lower than 100 ppb (by weight). The method according to feature 19.

21. The SiC deposited on the SiC growth substrate (857) has an impurity of substance Ti at a level lower than 10 ppb (by weight). The method according to the present invention, characterized by the present invention.

22. The SiC deposited on the SiC growth substrate (857) has impurities of substance N at a level lower than 10 ppm (by weight) and impurities of all of the metals Ti, V, Fe, and Ni in total at a level lower than 1000 ppb (by weight). The method according to feature 19.

23. The step of providing the source medium inside the processing chamber comprises the step of supplying the first fluid from the vent gas recirculation unit into the processing chamber. The method according to feature 1.

24. A crucible gas flow unit (170) is provided for causing a gas flow inside the crucible volume, the crucible gas flow unit (170) comprising a crucible gas inlet tube (172) for conducting a transport gas into the crucible volume (116) and a crucible gas outlet tube (174) for conducting the transport gas out of the crucible volume (116). The method according to any one of claims 1 to 23, characterized by...

25. The growth guide (231) is positioned inside the crucible housing (110). The growth guide (231) forms a gas path boundary (232) for guiding the gas flow in the direction of the seed holder unit (122). The growth guide (231) and the seed holder unit (122) form a gas flow passage (236). It is characterized by and A step of establishing a gas flow through the crucible volume (116) by conducting the transport gas into the crucible volume (116) through the crucible gas inlet tube (172), and by conducting the transport gas out of the crucible volume (116) through the crucible gas outlet tube (174), A step of establishing a predetermined gas flow velocity through the gas flow passage by controlling the gas flow into the crucible volume (116) through the crucible gas inlet tube (172), and / or In the step of establishing the predetermined gas flow velocity through the gas flow passage by controlling the gas flow out of the crucible volume (116) through the crucible gas outlet tube (174), The aforementioned gas flow velocity is between 1 cm / s and 10 cm / s. The aforementioned establishment stage, The method according to any one of claims 1 to 24, characterized by...

26. The receiving space (118) is located between the crucible gas inlet tube (172) and the seed holder unit (122). It is characterized by and The step of conducting the gas flow around and / or through the receiving space (118), The method according to any one of claims 1 to 25, characterized by...

27. At least Si 2 C sublimation vapor, SiC 2 A filter unit (130) for taking in sublimation vapor and Si sublimation vapor is positioned inside the crucible volume (116) between the seed holder unit (122) and the crucible gas outlet tube (174). The filter unit (130) forms a gas flow path (147) from the filter input surface (140) to the filter output surface (142), and this 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) has a height S1, and the gas flow path (147) passing through the filter unit (130) has a length S2, where S2 is at least twice as long as S1. It is characterized by and The steps include 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 1 to 26, characterized by...

28. 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 produce a crucible volume pressure (P1) that is higher than 2666.45 Pa or in the range between 2666.45 Pa and 50000.00 Pa. It is characterized by and A step of generating a crucible volume pressure (P1) inside the crucible volume that is higher than 2666.45 Pa, or in the range between 2666.45 Pa and 50000.00 Pa, The method according to any one of claims 1 to 27, characterized by...

29. A method for producing at least one SiC crystal (17) according to claim 28, The PVT reactor (100) comprises a crucible gas flow unit (170), the crucible gas flow unit (170) comprising a crucible gas inlet tube (172) for conducting gas into the crucible volume (116), the crucible gas inlet tube (172) being positioned vertically below the receiving space (118), It is characterized by and The step of conducting the gas into the crucible housing through the crucible gas flow unit (170), A method characterized by the following.

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