SiC growth substrate, CVD reactor and SiC production method

Abstract

The present invention relates to a SiC growth substrate for growing SiC in a CVD reactor. The SiC growth substrate includes a body having a body length, a first power connection configured to conduct power into the body to heat the body, and a second power connection configured to conduct power into the body to heat the body, the body length (ML) extending between the first power connection and the second power connection. And the second power connection is configured to conduct power conducted into the body through the first power connection out of the body, the body forming a deposition surface for depositing SiC to grow the SiC shell, the body being configured to resist a force generated by the SiC shell during growth of a minimum thickness of at least 1 cm, in this way, the body is prevented from cracking at least in the defined volume portion of the body due to the generated force. Wherein the defined volume portion is formed between a first plane and a second plane, the first plane being orthogonal to the body length, the second plane being orthogonal to the body length, the distance between the first plane and the second plane being at least 5% of the body length.

Description

Technical Field

[0001] The invention relates to a SiC growth substrate according to claim 1 , a CVD reactor according to claim 12 and a method for producing SiC according to claims 14 and 17 . Background Art

[0002] Power electronics based on silicon carbide (SiC) wafers outperform those based on traditional silicon (Si) wafers, primarily because SiC has a wider bandgap, enabling it to operate at higher voltages, temperatures, and frequencies. As the global transition to electric vehicles (EVs) gains momentum, interest in high-performance power electronics based on silicon carbide is growing, but the price of SiC wafers remains much higher than that of Si wafers.

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

[0004] Currently, SiC source materials used in industry are produced by the commercial Acheson process and then further purified by powdering and acid leaching. The Acheson process is the only known method for producing SiC source materials on an industrial scale. Acid leaching is used to extract trace metals from SiC, but it can only penetrate to a depth of less than about 1 micron from the surface of the particles. Therefore, the particles need to be small enough so that this penetration layer accounts for a large enough proportion of the total volume of the particles. Therefore, the average particle size of the powdered SiC particles usually needs to reach 200 to 300 microns. At this average particle size, the purity of this material can only reach about 99.99% or 99.999% (referred to as 4N or 5N purity, respectively).

[0005] In some cases, SiC source materials are produced by using silicon powder (especially mixed with graphite powder and sintered). Powdered SiC materials increase the surface area and are easily contaminated when handled and exposed to air. The main contaminants are trace metals, nitrogen and oxygen.

[0006] Although these acid-leached or sintered SiC materials have only a moderate 4N or 5N purity, they are expensive and significantly increase the overall cost of SiC wafers. The moderate purity also leads to high wafer costs because impurities cause crystal defects, and defective crystals must be discarded instead of being cut into wafers. In other words, impurities in the source material result in low crystal yields.

[0007] Trace metals present in SiC source materials are believed to be the main cause of crystal defects in single-crystal SiC boules grown using the PVT method. Currently, the quality of single-crystal SiC boules is several orders of magnitude lower than that of other semiconductor crystals such as silicon or gallium arsenide (GaAs) in terms of crystal defects (such as dislocations). These crystal defects can cause unnecessary electrical shorts in SiC electrical devices (vertical devices in most cases) and reduce the yield of electrical devices. Therefore, better solutions must be found to prevent crystal defects caused by impurities in the source materials.

[0008] In addition, metal impurities in SiC wafers made from single-crystal SiC ingots can interact with subsequent implantation and doping techniques to create SiC electrical devices, which can cause device failure and reduce the yield of electrical devices.

[0009] In addition, impurity (especially nitrogen) concentrations or impurity bands will appear in the crystal rod, resulting in wafers at different heights in the same crystal rod having conductivity that may be outside the required range, or differences between one side of the wafer and the other. For semi-insulating SiC wafers for RF applications, extremely low conductivity is required, so trace metals and nitrogen at very low concentrations are allowed in the wafer. For conductive SiC wafers for power applications, a certain amount of conductivity is required. But by providing nitrogen to the PVT crucible during the entire growth time, this conductivity can be uniformly achieved throughout the SiC crystal rod.

[0010] The shape factor of the SiC source material is also important in PVT growth. Powder source materials provide a high initial surface area for sublimation and therefore have a high initial sublimation rate. A high sublimation rate may be uneconomical if all the sublimated SiC species cannot be incorporated into the crystal and becomes a polycrystalline deposit that parasitizes on other parts of the crucible. Worse, a high concentration of SiC species in front of the crystal growth face may cause gas phase nucleation and form amorphous or polycrystalline inclusions in the single crystal ingot. Over time, powder source materials tend to sinter together to form a single piece of material with a greatly reduced surface area, so the sublimation rate decreases. The spiking and tailing phenomena that occur during the sublimation of powder source materials can lead to a slower overall rate of crystal growth and increase the likelihood of defects in the crystal. Finally, the tap density of powder source materials is low, about 1.2g / cm 3 , 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] Document GB1128757 discloses a method for depositing a thin SiC coating. However, the teaching of GB1128757 does not involve a method for mass production of SiC as a PVT source material.

[0012] DE1184738 (B) discloses a method for producing silicon carbide crystals in single crystal and polycrystalline form by reacting silicon halide with carbon tetrachloride in a molar ratio of 1:1 on a heated graphite body in the presence of hydrogen. In this process, a mixture of 1 volume fraction of silicon chloroform, 1 volume fraction of carbon tetrachloride and hydrogen is first flowed through the graphite body at a flow rate of 400 to 600 liters / hour until a dense silicon carbide layer is formed on the graphite body, and then flows through the deposition body at a flow rate of 250 to 350 liters / hour at a temperature of 1500 to 1600°C.

[0013] The downside of this existing technology is that it does not meet today's demand for cheap production of high-purity SiC in a large-scale industrial process. SiC is used in many areas of technology, especially in power applications and / or electric vehicles, to improve efficiency. In order for products requiring SiC to reach the mass market, manufacturing costs must be reduced and / or quality improved. Summary of the invention

[0014] It is therefore an object of the present invention to provide a low cost supply of silicon carbide (SiC). Additionally or alternatively, high purity SiC should be provided. Additionally or alternatively, SiC should be provided very quickly. Additionally or alternatively, SiC should be able to be produced very efficiently. Additionally or alternatively, single crystal SiC should be produced with advantageous properties.

[0015] The aforementioned objects are achieved by a SiC growth substrate according to claim 1. Such a SiC growth substrate is preferably configured for growing SiC in a CVD reactor and preferably comprises at least a body, preferably a first power connection and preferably a second power connection, wherein the body has a body length, wherein the body length extends between the first power connection and the second power connection, wherein the first power connection is configured for conducting power into the body for heating the body, and wherein the second power connection is configured for conducting power conducted into the body via the first power connection out of the body, wherein the body is formed or represented as a physical structure, or the body is a physical structure, wherein the physical structure (or body structure) forms a deposition surface for depositing SiC for growing a SiC shell, wherein the physical structure (or body structure) is configured to resist forces generated during the growth of the SiC shell to a thickness of at least 1 cm, or is configured to prevent the generation of these forces during the growth of the SiC shell to a thickness of at least 1 cm, so as to prevent the physical structure (or body structure) from being broken at least in a defined volume portion of the physical structure (or body structure) due to the generated forces. The defined volume portion is preferably formed between a first plane and a second plane, wherein the first plane is perpendicular to the body length, and wherein the second plane is perpendicular to the body length, wherein the distance between the first plane and the second plane is preferably at least 5% of the body length.

[0016] This solution is beneficial because it has been found that the greater the distance between the center of the SiC growth substrate and the deposition surface, the greater the temperature difference between the deposition surface and the center of the SiC growth substrate. Due to the large temperature difference, the physical difference affects the mechanical stability. Therefore, the present invention provides a solution to compensate for the physical difference and / or avoid the physical difference.

[0017] Further preferred embodiments of the present invention will be described in the following description.

[0018] According to a preferred embodiment of the present invention, the physical structure is configured to resist the forces generated during the growth of the SiC shell to a minimum thickness of at least 3 cm to prevent the physical structure from being broken due to the generated forces. This embodiment is beneficial because the temperature difference between the center of the SiC growth substrate and the deposition surface is greater than when the thickness of the SiC shell is 1 cm.

[0019] According to another preferred embodiment of the present invention, the physical structure is configured to resist the forces generated during the growth of the SiC shell to a minimum thickness of at least 5 cm to prevent the physical structure from being broken due to the generated forces. This embodiment is beneficial because the temperature difference between the center of the SiC growth substrate and the deposition surface is greater than when the thickness of the SiC shell is 3 cm.

[0020] According to another preferred embodiment of the present invention, the physical structure comprises carbon fiber. This embodiment is beneficial because the carbon fiber can be heated to a temperature above 1500°C or above 1800°C or between 1400°C and 2000°C. In addition, the carbon fiber can withstand high tensile loads. Carbon fiber has multiple advantages, including high stiffness, high tensile strength, high strength-to-weight ratio, high chemical resistance, high temperature resistance and low thermal expansion. The atomic structure of carbon fiber is similar to that of graphite, consisting of sheets of carbon atoms (graphene sheets) arranged in a regular hexagonal pattern, except that the sheets are staggered in a certain manner. Graphite is a crystalline material in which the sheets are stacked parallel to each other in a regular manner. The intermolecular forces between the sheets are relatively weak van der Waals forces, which make graphite soft and brittle.

[0021] According to another preferred embodiment of the invention, the physical structure is formed of a carbon fiber composite material. This embodiment is beneficial because the fiber orientation of the carbon fiber composite material covers at least two directions, thus also allowing compensation of forces in multiple directions. An example of a preferred carbon fiber composite material is SIGRABOND Standard produced by SGL Carbon GmbH.

[0022] In a preferred embodiment of the present invention, the physical structure formed by the carbon fiber composite material has a tensile strength higher than 50 MPa (see DIN IEC 60413 / 501) and / or a flexural strength higher than 50 MPa. This embodiment is advantageous in that the high tensile loads caused by the high temperature difference generated by the thick SiC shell can be compensated.

[0023] According to a preferred embodiment of the invention, the physical structure has a ribbon-like shape at least partially and preferably along more than 50% of the length of the physical structure and most preferably completely, wherein the ribbon-like shape forms a cross section with a width W and a depth D, wherein the width W is at least 2 times, preferably at least 3 times, more preferably at least 5 times, most preferably up to 10 times or exactly 10 times or more than 10 times the depth D. This embodiment is beneficial because the size of the deposition surface is significantly larger compared to a cylinder. Therefore, SiC deposition can be performed faster compared to a smaller deposition surface. The width W is preferably less than 1.5 cm, in particular less than 1 cm or less than 0.5 cm, in particular less than 3 mm or less than 2 mm or less than 1 mm, and the depth D is greater than 3 cm, in particular greater than 5 cm or greater than 8 cm.

[0024] According to a preferred embodiment of the invention, the physical structure at least partially and preferably along more than 50% of the length of the physical structure and most preferably completely has a tubular shape, wherein the tubular shape forms a cross section with an average wall thickness of less than 5 cm, preferably less than 2 cm, particularly preferably less than 1 cm. This embodiment is beneficial because less energy is required to heat the deposition surface to the same temperature compared to a solid rod.

[0025] According to a preferred embodiment of the present invention, the physical structure is formed by a SiC element (particularly a rod or a tube or a blade, particularly a polycrystalline SiC element). This embodiment is advantageous in that the SiC element and the SiC shell have the same or very close thermal expansion coefficients, thereby being able to reduce or prevent forces due to temperature differences.

[0026] According to a preferred embodiment of the present invention, the SiC element contains more than 75 mass %, preferably more than 95 mass %, more preferably more than 99 mass % SiC. This embodiment is advantageous in that the more SiC the SiC element contains, the closer its thermal expansion coefficient is to that of the SiC shell.

[0027] According to another preferred embodiment of the present invention, the SiC of the SiC growth substrate has a thermal conductivity of less than 5.7×10 - 6 K -1 The thermal expansion coefficient is 5.6x10 -6 K -1 Up to 5.7x10 -6 K -1 The coefficient of thermal expansion.

[0028] According to a preferred embodiment of the present invention, the impurity content of substance N in the SiC growth substrate is less than 10 ppm (weight), and the impurity content of each substance of B, Al, P, Ti, V, Fe, and Ni is less than 1000 ppb (weight), especially less than 500 ppb (weight). Preferably, the impurity content of substance N in the SiC growth substrate is less than 2 ppm (weight), and the impurity content of each substance of B, Al, P, Ti, V, Fe, and Ni is less than 100 ppb (weight). Additionally or alternatively, the impurity content of substance Ti in the SiC growth substrate is less than 10 ppb (weight). Alternatively, the impurity content of substance N in the SiC growth substrate is less than 10 ppm (weight), and the impurity content of all metal Ti, V, Fe, and Ni substances is less than 1000 ppb (weight), especially less than 500 ppb (weight). The benefit of this embodiment is that the produced SiC can be used as a raw material for the PVT process for producing single crystal SiC.

[0029] According to a preferred embodiment of the present invention, the physical structure is a single component. This embodiment is advantageous in that a very uniform SiC shell can be formed.

[0030] According to a preferred embodiment of the present invention, the physical structure is formed by a plurality of components, wherein at least some of the plurality of components, more preferably most of the components, most preferably all of the components, are preferably connected to each other by form fit and / or force fit. This embodiment is beneficial because the individual components are less expensive than a single component. In addition, it is also easy to handle the individual components before forming the SiC growth substrate.

[0031] According to a preferred embodiment of the present invention, the physical structure is formed of a plurality of components, wherein at least some of the plurality of components, and preferably most of the components, and most preferably all of the components are made of a material having a first coefficient of thermal expansion (CTE), wherein the first coefficient of thermal expansion is different from the coefficient of thermal expansion of polycrystalline SiC. The first coefficient of thermal expansion differs from the coefficient of thermal expansion of polycrystalline SiC by at least 0.1x10 -6 K -1 , preferably with a difference of 0.5x10 -6 K -1 , most preferably differ by at least 0.1x10 -6 K -1 The present embodiment is advantageous in that the SiC growth substrate can be made of different materials (eg, tungsten or graphite).

[0032] According to a preferred embodiment of the invention, the plurality of components comprises at least two components of the main component type and at least one component of the connecting component type, wherein the at least two main components are coupled by at least one connecting component, wherein the components of the main component type have a tubular or rod-like or blade-like shape, and wherein at least most of the components of the main component type are longer than the components of the connecting component type. This embodiment is advantageous in that the maximum thermal expansion of each part is below a defined limit even in the case of forming a SiC shell having a thickness greater than 1 cm, or preferably greater than 3 cm, or most preferably greater than 5 cm, and even if the temperature difference between the deposition surface and the center of the SiC growth substrate is greater than 10°C, or greater than 30°C, or greater than 50°C, or greater than 100°C, or between 50°C and 400°C, in particular between 70°C and 250°C.

[0033] According to a preferred embodiment of the present invention, the length of each of the at least two main component types is less than 100 cm and more than 5 cm, and preferably less than 90 cm and more than 10 cm, and particularly preferably less than 85 cm and more than 15 cm, and most preferably less than 80 cm and more than 20 cm.

[0034] According to a preferred embodiment of the invention, at least two components of the main component type, preferably most of the components of the main component type and most preferably all components of the main component type are made of graphite.

[0035] According to a preferred embodiment of the invention, a first component of at least two components of the main component type has a first central axis, and a second component of at least two components of the main component type has a second central axis, wherein the first central axis and the second central axis are arranged parallel to each other and more preferably are not coaxial. More preferably, the distance between the first central axis and the second central axis is greater than 5 cm, preferably greater than 8 cm, particularly preferably greater than 12 cm, most preferably greater than 15 cm or between 10 cm and 30 cm, in particular between 11 cm and 25 cm or between 12 cm and 20 cm. This embodiment is advantageous in that the thermal expansion of the individual components is independent of each other.

[0036] According to a preferred embodiment of the present invention, the physical structure forms a U-shape. This embodiment is advantageous in that the electrodes can be arranged on one side of a wall member or a bottom member, respectively.

[0037] The above object is also achieved by a CVD reactor according to claim 18. The CVD reactor according to the present invention preferably comprises a process chamber, wherein the process chamber is at least surrounded by a bottom plate, a side wall portion and a top wall portion; a gas inlet unit for feeding one or more feed media into a reaction space of the process chamber to produce a source medium, wherein the gas inlet unit is coupled to at least one feed medium source, wherein the Si and C feed medium sources provide at least Si and C, in particular SiCl3 (CH3), and wherein the carrier gas feed medium source provides a carrier gas, in particular H2, or wherein the gas inlet unit is coupled to at least two feed medium sources, wherein the Si feed medium source provides at least Si, and wherein the C feed medium source provides at least C, in particular natural gas, methane, ethane, propane, butane and / or acetylene, and wherein the carrier gas medium source provides a carrier gas, in particular H2, arranged inside the process chamber for depositing a source medium of SiC. One or more SiC growth substrates according to claims 1 to 18, in particular more than 3 or more than 4 or more than 6 or more than 8 or more than 16 or more than 32 or more than 64 or up to 128 or up to 256 SiC growth substrates, wherein each SiC growth substrate preferably comprises a first power connection and a second power connection, wherein the first power connection is a first metal electrode, and wherein the second power connection is a second metal electrode, wherein the first metal electrode and the second metal electrode are preferably isolated from the reaction space, wherein each SiC growth substrate is coupled between at least one first metal electrode and at least one second metal electrode for heating the outer surface of the SiC growth substrate or the surface of the deposited SiC, in particular by resistive heating and preferably by internal resistive heating, to a temperature between 1300° C. and 1800° C.

[0038] According to a preferred embodiment of the present invention, at least one first metal electrode and at least one second metal electrode (wherein at least one first metal electrode and at least one second metal electrode are connected to the same SiC growth substrate) are connected to an alternating current source, wherein the alternating current source is configured to set the frequency of the alternating current to be higher than 5 Hz, or preferably higher than 20 Hz, or more preferably higher than 50 Hz, or most preferably higher than 500 Hz or up to 5000 Hz, in particular up to 2000 Hz or up to 1000 Hz or up to 500 kHz. This is beneficial because due to the effect of the alternating current, the power is guided along the outer surface of the growing SiC, so the heating degree of the center is lower compared to a direct current. This is beneficial because the temperature of the center is preferably lower than the temperature of the outer surface. This is very beneficial to form a uniform temperature distribution between the center and the outer surface, so the temperature difference between the outer surface and the center is preferably lower than 300K, more preferably 200K, particularly preferably lower than 100K, and most preferably lower than 50K. This is beneficial to grow SiC at low tension levels to avoid cracking of the SiC.

[0039] According to a preferred embodiment of the present invention, each SiC growth substrate comprises a first power connection and a second power connection, wherein the first power connection is a first metal electrode, and wherein the second power connection is a second metal electrode, wherein the first metal electrode and the second metal electrode are preferably isolated from the reaction space inside the process chamber, wherein each SiC growth substrate is coupled between at least one first metal electrode and at least one second metal electrode for heating the outer surface of the SiC growth substrate or the surface of the deposited SiC (particularly by resistive heating, preferably by internal resistive heating) to a temperature between 1300° C. and 1800° C. This embodiment is advantageous in that the SiC growth substrate can be heated very efficiently.

[0040] Since the flow current requires an inlet electrode and an outlet electrode, these electrodes are preferably arranged in pairs, for example, preferably 12 pairs or 18 pairs or 24 pairs or 36 pairs or more. Preferably, the deposition substrate or SiC growth substrate is attached to each electrode (particularly a metal electrode) of the electrode pair (the first and second metal electrodes), and the substrate is connected at the top by a cross member or bridge of the same material as the substrate to complete the circuit. The deposition substrate or SiC growth substrate is preferably attached to the electrode through an intermediate piece or a chuck. The chuck preferably has a reduced cross-sectional area extending from the electrode to the deposition substrate, so that the current is concentrated and the resistive heating is increased. The purpose of the chuck is to keep the temperature of the lower wider end below the deposition temperature and the temperature of the upper narrower end above the deposition temperature. The chuck is preferably conical. The chuck, deposition substrate and bridge are preferably made of graphite, or more preferably made of high-purity graphite, with a total ash content of less than 50000ppm, preferably less than 5000ppm, more preferably less than 500ppm. The deposition substrate is also preferably made of SiC. According to another aspect of the invention, the contact surface between the first metal electrode and the SiC growth substrate is different from the contact surface between the second metal electrode and the SiC growth substrate.The second electrode may preferably be arranged or disposed on the opposite side of the process chamber and / or as part of a bell jar.

[0041] According to a preferred embodiment of the present invention, the process chamber is surrounded by at least a bottom plate, a side wall portion and a top wall portion. This embodiment is beneficial because the process chamber can be isolated by the bottom plate, the side wall portion and the top wall portion, respectively. The bottom plate is also preferably provided with a plurality of gas inlet ports and a gas outlet port or a plurality of gas outlet ports. The arrangement of the gas inlet port and the outlet port enables an optimal feed gas flow to be generated in a CVD reactor or in a SiC production reactor (in particular, in a SiC PVT source material production reactor), so that fresh feed gas is continuously in contact with the deposition surface on the deposition substrate.

[0042] According to another preferred embodiment of the present invention, the gas inlet unit is coupled to at least one feed medium source, wherein one of the feed medium sources is a Si and C feed medium source, wherein the Si and C feed medium source provides at least Si and C, in particular SiCl3 (CH3), and wherein the carrier gas feed medium source provides a carrier gas, in particular H2, or wherein the gas inlet unit is coupled to at least two feed medium sources, wherein one of the two feed medium sources is a Si feed medium source, wherein the Si feed medium source provides at least Si, in particular Si gas conforming to the general formula SiH4-yXy (X=[Cl,F,Br,J] and y=[0..4]), and the other of the two feed medium sources is a C feed medium source, wherein the C feed medium source provides at least C, in particular natural gas, methane, ethane, propane, butane and / or acetylene, and wherein the carrier gas medium source provides a carrier gas, in particular H2.

[0043] Alternatively, the first feed medium is a Si feed medium, in particular a Si gas conforming to the general formula SiH4-y Xy (X = [Cl, F, Br, J] and y = [0..4]), wherein the gas inlet unit is coupled to at least one feed medium source, wherein a C feed medium source provides at least C, in particular a C feed medium source that provides a second feed medium, wherein the second feed medium is a C feed medium, in particular natural gas, methane, ethane, propane, butane and / or acetylene, and wherein a carrier gas medium source provides a third feed medium, wherein the third feed medium is a carrier gas, in particular H2.

[0044] Natural gas is preferably defined as a gas having multiple components, the largest component of which is methane, in particular more than 50 mass % methane, preferably more than 70 mass % methane, more preferably more than 90 mass % methane, most preferably more than 95 mass % or more than 99 mass % methane.

[0045] Therefore, the SiC production reactor or CVD SiC device is preferably also equipped with a feed gas unit or a medium supply unit for supplying feed gas to the gas inlet unit. The feed gas unit or the medium supply unit ensures that the feed gas is heated to a suitable temperature and mixed in a suitable proportion before being pumped into the CVD reactor or the SiC production reactor (especially the SiC PVT source material production reactor). The feed gas unit or the medium supply unit starts with a pipeline and a pump, which transports the feed gas from its respective source (especially a storage tank) to the vicinity of the CVD reactor or the SiC production reactor (especially the SiC PVT source material production reactor). In this article, the mass flow rate of each feed gas is preferably controlled by a separate mass flow meter, which is connected to the entire process control device so that the correct proportion of various feed gases can be achieved. Then, the separate feed gases are preferably mixed in a mixing unit (especially a mixing unit of a medium supply unit) and pumped into the CVD reactor or the SiC production reactor (especially the SiC PVT source material production reactor) through the gas inlet unit (especially through multiple gas inlets of the gas inlet unit). Preferably, the feed gas unit or the medium supply unit is capable of mixing three feed gases, including a Si-containing gas (e.g., STC and / or SiCl3H (wherein SiCl3H may be referred to as TCS)), a C-containing gas (e.g., methane), and a carrier gas (e.g., H). In another preferred embodiment of the present invention, there is a feed gas containing both Si and C (e.g., SiCl3(CH3)) (wherein SiCl3(CH3) may alternatively be referred to as MTCS), and the feed gas unit mixes two gases (i.e., MTCS and H) instead of three gases. It should be noted that STC, TCS, and MTCS are all liquid at room temperature. Therefore, a preheater may be required upstream of the gas inlet unit (particularly upstream of the feed gas unit or the medium supply device) to first heat these feed liquids to make them feed gases for mixing with other feed gases.

[0046] Preferably, the gases are mixed so that the atomic ratio between Si and C is 1:1. In some cases, it may be more preferable to mix the gases so that the atomic ratio between Si and C is different. Sometimes, it is desirable to keep the deposition surface at the higher end of the deposition temperature range of 1300°C to 1600°C to achieve a faster deposition rate. However, in this case, there may be excess C deposition in the SiC. This can be adjusted by mixing the feed gases so that the Si:C ratio is higher than 1:1, preferably 1:1.1 or 1:1.2 or 1:1.3. Conversely, it is sometimes desirable to keep the deposition surface at the lower end of the deposition temperature range to achieve slow stress-free deposition. In this case, there may be excess Si deposition in the SiC. This can be adjusted by mixing the feed gases so that the Si:C ratio is lower than 1:1, preferably 1:0.9 or 1:0.8 or 1:0.7.

[0047] Another important consideration for the feed gas mixture is the atomic ratio of H to Si and C. Excess H dilutes Si and C and reduces the deposition rate. Excess H also increases the amount of exhaust gas discharged from the CVD reactor or SiC production reactor (particularly the SiCPVT source material production reactor) and complicates the treatment and recovery of these exhaust gases. On the other hand, insufficient H slows down the chemical reaction chain that leads 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.

[0048] According to another embodiment of the present invention, more or up to 4, or preferably more or up to 6 or 8, more preferably more or up to 16 or 32 or 64, or most preferably up to 128 or up to 256 SiC growth substrates may be arranged inside the SiC production reactor.

[0049] The advantage of this embodiment is that the throughput of the SiC reactor can be significantly improved by adding an additional SiC growth substrate.

[0050] According to another preferred embodiment of the present invention, a control unit for setting the supply of one or more feed media into the process chamber is provided, wherein the control unit is configured to set the feed medium supply amount between a minimum feed medium supply amount [mass] per minute and a maximum feed medium supply amount [mass] per minute, wherein the minimum feed medium supply amount [mass] per minute corresponds to a minimum Si deposition amount [mass] and a minimum C deposition amount [mass] at a defined mass growth rate, wherein the defined mass growth rate is greater than a mass growth rate of the SiC growth surface of 0.1 g per square centimeter per hour, wherein the maximum feed medium supply amount per minute is at most 30 mass % or at most 20 mass % or at most 10 mass % or at most 5 mass % or at most 3 mass % higher than the minimum feed medium supply amount. This embodiment is advantageous in that the supply of the feed medium can be controlled according to the desired SiC conditions.

[0051] According to another preferred embodiment of the present invention, the control unit is configured to control the flow of current through the SiC growth substrate to maintain the surface temperature of the SiC growth substrate or set the surface temperature of the deposited SiC. This embodiment is beneficial in that the deposition of SiC can be maintained by setting the required temperature conditions.

[0052] According to another preferred embodiment of the present invention, the control unit is configured to control the current flow and the supply amount of the feed medium for at least one hour, preferably at least two hours or four hours or six hours, so as to continuously deposit SiC at a defined surface growth rate and / or a defined radial growth rate. This embodiment is beneficial in that a large amount of SiC solid can be generated.

[0053] According to another preferred embodiment of the present invention, the control unit is a hardware device configured to modify the flow of current, wherein the modification of the flow of current is predefined within a first defined time span from the start of the production run. The benefit of this embodiment is that the hardware can adapt to the defined process without the need for additional sensors. The first time span is preferably one hour or more, or up to 60% of the duration of the production run, or up to 80% of the duration of the production run, or up to 90% of the duration of the production run, or up to 100% of the duration of the production run. The hardware device is preferably configured to modify the supply of the feed medium, wherein the modification of the supply of the feed medium is predefined within a second defined time span from the start of the production run, wherein the second time span is one hour or more, or up to 60% of the duration of the production run, or up to 80% of the duration of the production run, or up to 90% of the duration of the production run, or up to 100% of the duration of the production run.

[0054] According to another preferred embodiment of the present invention, at least one sensor is provided, wherein the sensor is coupled to a control unit to provide a sensor signal or sensor data to the control unit, wherein the control unit controls the current flow and the supply of the feed medium according to the sensor signal or sensor data of the at least one sensor, wherein the at least one sensor is a temperature sensor for monitoring the surface temperature of at least one substrate. The at least one temperature sensor is preferably a camera (in particular an infrared camera), wherein preferably a plurality of temperature sensors are provided, wherein the number of temperature sensors corresponds to the number of SiC growth substrates, wherein at least one, in particular two or five, ten or twenty temperature sensors are provided for every ten SiC growth substrates, or wherein at least one, in particular two or five, ten or twenty temperature sensors are provided for every five SiC growth substrates, or wherein at least one, in particular two or five, ten or twenty temperature sensors are provided for every two SiC growth substrates, wherein the temperature sensor preferably outputs a temperature sensor signal or temperature sensor data representing the measured temperature, in particular the surface temperature. This embodiment is advantageous in that the conditions in the SiC production reactor can be adjusted immediately.

[0055] According to another preferred embodiment of the present invention, at least one substrate diameter measuring sensor is provided, wherein the substrate diameter measuring sensor is preferably an IR camera for determining the growth of the substrate diameter, wherein the substrate diameter measuring sensor preferably outputs a diameter measurement signal or diameter measurement data representing the measured substrate diameter or the measured change in the substrate diameter, and / or a resistance determination device for determining a change in resistance to determine the growth of the substrate diameter, wherein the substrate diameter measuring sensor preferably outputs a diameter measurement signal or diameter measurement data representing the measured substrate diameter or the measured change in the substrate diameter. This embodiment is advantageous in that parameters such as the current flow or the feed medium supply can be modified (in particular increased) based on the measured data or values.

[0056] According to another preferred embodiment of the present invention, one or more valves are provided, wherein the one or more valves are configured to be actuated according to a measured temperature, in particular according to a temperature sensor signal or temperature sensor data, and / or wherein the one or more valves are configured to be actuated according to a measured substrate diameter, in particular according to a diameter measurement signal or diameter measurement data. The one or more valves may be part of a gas inlet unit. The advantage of this embodiment is that the feed medium flow and / or the exhaust flow may be controlled. Therefore, according to another preferred embodiment of the present invention, the control unit is configured to increase the electrical energy of at least one SiC growth substrate over time, in particular to heat the surface of the deposited SiC to a temperature between 1300°C and 1800°C.

[0057] According to another preferred embodiment of the present invention, the power supply unit for providing current is configured to provide current according to the diameter measurement signal or the diameter measurement data. This embodiment is advantageous in that the feed medium flow and / or the exhaust gas flow can be controlled.

[0058] Therefore, the control unit is preferably configured to receive temperature sensor signals or temperature sensor data and / or diameter measurement signals or diameter measurement data, and to 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.

[0059] According to another preferred embodiment of the present invention, the control unit is configured to control the feed medium flow and the temperature of the surface on which SiC is deposited so as to deposit SiC at a set deposition rate (particularly a vertical deposition rate) for a deposition time of more than 2 hours, particularly more than or up to 3 hours, or more than or up to 5 hours, or more than or up to 8 hours, or preferably more than or up to 10 hours, or more preferably more than or up to 15 hours, or most preferably more than or up to 24 hours, or up to 72 hours, or up to 100 hours. The benefit of this embodiment is that a large amount of SiC can be grown.

[0060] According to another preferred embodiment of the present invention, the bottom plate includes at least one cooling element (in particular a bottom cooling element) for preventing the bottom plate from being heated to a temperature exceeding a defined temperature, and / or the side wall portion includes at least one cooling element (in particular a bell jar cooling element) for preventing the side wall portion from being heated to a temperature exceeding a defined temperature, and / or the top wall portion includes at least one cooling element (in particular a bell jar cooling element) for preventing the top wall portion from being heated to a temperature exceeding a defined temperature.

[0061] The benefit of this embodiment is that the present invention discloses a CVD SiC device for large-scale commercial production of ultrapure bulk CVD SiC. The central equipment in the CVD SiC device is a CVD unit or a CVD reactor or a SiC production reactor (especially a SiC PVT source material production reactor). The CVD reactor or the SiC production reactor (especially the SiC PVT source material production reactor) preferably includes a cooling element, which is especially a lower shell (or substrate) cooled by a double-walled fluid (especially water or oil) and an upper shell (or bell jar) cooled by a double-walled liquid. The inner wall of the bottom plate and especially the inner wall of the bell jar are preferably made of a material whose use temperature is compatible with the working temperature of the CVD reactor or the SiC production reactor (especially the SiCPVT source material production reactor). In particular, the inner wall of the bell jar can be made of stainless steel. Preferably, this inner wall is additionally or alternatively coated with a reflective coating (for example, preferably silver or preferably gold) to reflect back the radiant energy, minimize heat loss, and thus reduce electricity costs. The bell jar and / or the bottom plate are preferably made of high temperature resistant stainless steel. However, currently, high-temperature steels with added chromium, nickel, cerium or yttrium can only withstand temperatures up to 1300°C (in air). For example, steel EN 1.4742 (X10CrAlSi18) can withstand temperatures up to 1000°C. In another example, alloy steel EN 2.4816 (UNS N06600) can withstand temperatures of 1250°C and melts above 1370°C, but its tensile strength drops to less than 10% of the room temperature value above 1100°C. Therefore, these steels cannot withstand the high temperatures of more than 1300°C required to absorb SiC.

[0062] It would therefore be beneficial to provide a cooling element to reduce the temperature of the bell jar and / or base plate to a level that is acceptable when using high temperature stainless steel.

[0063] The base plate is preferably provided with one or more electrodes cooled by a fluid (particularly water or oil) for providing an electrical through-connection to a CVD reactor or a SiC production reactor (particularly a SiC PVT source material production reactor) for resistive heating of the deposition substrate. According to another preferred embodiment of the invention, the cooling element is an active cooling element.

[0064] According to another preferred embodiment of the invention, the bottom plate and / or the side wall portion and / or the top wall portion comprises a cooling fluid guiding unit for guiding the cooling fluid, wherein the cooling fluid guiding unit is configured to limit the heating of the bottom plate and / or the side wall portion and / or the top wall portion to a temperature below 1300° C. This embodiment is advantageous in that a metal bell jar (particularly a steel bell jar) can be provided. The steel bell jar is advantageous in that it can be produced in much larger sizes than a quartz bell jar.

[0065] According to another preferred embodiment of the present invention, a sensor unit for the bottom plate and / or the side wall portion and / or the top wall portion is provided to detect the temperature of the bottom plate and / or the side wall portion and / or the top wall portion and output a temperature signal or temperature data, and a fluid delivery unit for delivering the cooling fluid through the fluid guide unit is provided. This embodiment is advantageous in that continuous cooling can be performed without loss or contamination of the cooling liquid and / or the process chamber.

[0066] According to another preferred embodiment of the present invention, the fluid delivery unit is configured to operate according to the temperature signal or temperature data provided by the bottom plate and / or the side wall portion and / or the top wall portion sensor unit. This embodiment is beneficial in that: when the bell jar and / or the bottom plate are operated at a temperature below 1000°C, preferably below 800°C, more preferably below 400°C, respectively, or when the bell jar and / or the bottom plate are cooled to a temperature below 1000°C, preferably below 800°C, more preferably below 400°C, metal impurities can be avoided.

[0067] According to another preferred embodiment of the invention, the cooling fluid is oil or water, wherein the water preferably contains at least one additive, in particular a corrosion inhibitor and / or an antifouling agent (biocide). This embodiment is advantageous in that the cooling liquid can be modified to avoid defects or contamination of the SiC production reactor.

[0068] According to another preferred embodiment of the present invention, the cooling element is a passive cooling element. This embodiment is advantageous in that the passive cooling element does not require continuous monitoring.

[0069] According to another preferred embodiment of the present invention, the cooling element is at least partially formed by a polished steel surface of the bottom plate, the side wall portion and / or the top wall portion. According to another preferred embodiment of the present invention, the cooling element is a coating, wherein the coating is formed above the polished steel surface and the coating is configured to reflect heat. According to another preferred embodiment of the present invention, the coating is a metal coating or comprises a metal (especially silver or gold or chromium) or alloy (especially CuNi alloy) coating. According to another preferred embodiment of the present invention, the emissivity of the polished steel surface and / or the coating is lower than 0.3, especially lower than 0.1 or lower than 0.03. The benefit of this embodiment is that a large amount of thermal radiation can be reflected back to the SiC growth surface due to the polished surface and / or the coating.

[0070] Therefore, according to another preferred embodiment of the present invention, at least a portion of the bell jar surface and / or at least a portion of the base unit surface comprises a coating (in particular a reflective coating), wherein this portion of the bell jar surface and / or this portion of the base unit surface defines a reaction space, wherein the coating is a metal coating, in particular comprising or consisting of gold, silver, aluminum and / or platinum, and / or wherein the coating is configured to reflect at least 2% or at least 5% or at least 10% or at least 20% of the radiant energy radiated during a production run onto the coating.

[0071] According to another preferred embodiment of the present invention, the bottom plate includes at least one active cooling element and one passive cooling element for preventing the bottom plate from being heated to a temperature exceeding a defined temperature, and / or the side wall portion includes at least one active cooling element and one passive cooling element for preventing the side wall portion from being heated to a temperature exceeding a defined temperature, and / or the top wall portion includes at least one active cooling element and one passive cooling element for preventing the top wall portion from being heated to a temperature exceeding a defined temperature.

[0072] According to another preferred embodiment of the invention, the side wall portion and the top wall portion are formed by a bell jar, wherein the bell jar is preferably movable relative to the base plate. According to another preferred embodiment of the invention, more than 50% by mass of the side wall portion and / or more than 50% by mass of the top wall portion and / or more than 50% by mass of the base plate are made of metal, in particular steel. The benefit of this embodiment is that a large steel bell jar can be manufactured, thereby significantly increasing the process chamber volume and thus increasing the amount of potential SiC material. Therefore, a bell jar is preferably provided, wherein, according to another preferred embodiment of the invention, the bell jar comprises a contact area for forming an interface with the base unit, wherein the interface is sealed to prevent leakage of gaseous substances, wherein the bell jar comprises a bell jar cooling unit, wherein the bell jar cooling element forms at least one channel or groove or groove for accommodating or guiding a bell jar cooling liquid, wherein the bell jar cooling element is configured to cool at least one portion of the bell jar and preferably the entire bell jar to below a defined temperature to remove a defined amount of heat per minute respectively during a production run. The bell jar cooling element and / or the base plate cooling element are preferably controlled by a control unit. Additionally or alternatively, the bell jar cooling element and / or the base cooling element are coupled to each other to form one main cooling unit.

[0073] According to another preferred embodiment of the present invention, the base unit comprises at least one base cooling element for cooling the base unit, wherein the base cooling element forms at least one channel or groove or recess for accommodating or guiding the base cooling liquid. According to another preferred embodiment of the present invention, the base cooling element is arranged in the region of at least one first metal electrode, and preferably also in the region of at least one second metal electrode, wherein the base cooling element is configured to cool the base unit (in particular the surface of the base unit arranged inside the reactor) in the region of at least one first metal electrode and preferably also in the region of at least one second metal electrode to below a defined temperature to remove a defined amount of heat from the base unit respectively per minute, or the base cooling element is configured to cool the entire base unit to below a defined temperature during the entire production run to remove a defined amount of heat respectively per minute during the production run. The benefit of this embodiment is that the electrode can be operated at high currents without damaging the SiC reactor.

[0074] According to another preferred embodiment of the present invention, the first metal electrode and the SiC growth substrate are connected to each other via a first graphite chuck, and / or the second metal electrode and the SiC growth substrate are connected to each other via a second graphite chuck. This embodiment is advantageous in that current can be introduced into the SiC growth substrate in a uniform manner. According to another preferred embodiment of the present invention, the first graphite chuck and / or the second graphite chuck are mounted on a base unit.

[0075] According to another preferred embodiment of the present invention, the first metal electrode and the second metal electrode are sealed with the reaction chamber to avoid the metal substances of the first metal electrode and the second metal electrode from causing metal substance contamination to the reaction chamber, the first metal electrode and the second metal electrode preferably enter the base unit from the first side of the base unit, wherein the first metal electrode and the second metal electrode preferably extend in the base unit to the other side of the base unit, wherein the other side of the base unit is opposite to the first side, wherein the first metal electrode and preferably the second metal electrode extend in the base unit to a sealing level below the process chamber surface of the base unit, wherein the process chamber surface is formed on the other side of the base unit. The benefit of this embodiment is that contamination of the reaction space can be avoided.

[0076] According to another preferred embodiment of the present invention, a sealing wall member is formed between the sealing level and the process chamber surface, wherein the sealing wall member separates the SiC growth substrate from the first metal electrode and preferably from the second metal electrode. This embodiment is advantageous in that short circuits can be prevented.

[0077] According to another preferred embodiment of the present invention, the control unit is configured to control the flow of current 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, wherein the control unit is coupled to a power supply unit to provide the current, wherein the power supply unit is configured to receive power supply data or a power supply signal provided by the control unit; and / or to supply a feed medium of one or more feed media into the process chamber, wherein the control unit is coupled to a medium supply unit to provide one or more feed media to the gas inlet unit, wherein the medium supply unit is configured to receive medium supply data or a medium supply signal provided by the control unit; and / or cooling of the base unit, wherein the control unit is coupled to a base cooling element to cool the base unit, wherein the base cooling element is configured to receive base cooling data or a base cooling signal provided by the control unit, and / or cooling of the bell jar, wherein the control unit is coupled to a bell jar cooling element for cooling the bell jar, wherein the bell jar cooling element is configured to receive bell jar cooling data or a bell jar cooling signal provided by the control unit, and / or the control unit is configured to set a deposition rate (especially a vertical deposition rate) greater than 200 μm / h, in particular by controlling at least the power supply unit and the medium supply unit. This embodiment is beneficial in that the control unit can control multiple parameters and the output can be increased by operating the heating, feeding and cooling units simultaneously.

[0078] According to another preferred embodiment of the present invention, the medium supply unit is configured to supply one or more feed media into the process chamber at a pressure greater than 1 bar, in particular a pressure greater than 1.2 bar, or preferably a pressure greater than 1.5 bar, or more preferably a pressure greater than 2 bar or 3 bar or 4 bar or 5 bar, or a pressure up to 10 bar, or a pressure up to 20 bar. Additionally or alternatively, according to another preferred embodiment of the present invention, the medium supply unit is configured to supply one or more feed media and carrier gas into the process chamber at a pressure greater than 1 bar, in particular a pressure greater than 1.2 bar or 1.5 bar or 2 bar or 3 bar or 4 bar or 5 bar. The benefit of this embodiment is that the material density in the process chamber is high, and a large amount of Si and C materials will reach the SiC growth surface, thereby promoting the growth of SiC.

[0079] According to another preferred embodiment of the present invention, at least one SiC growth substrate and preferably multiple SiC growth substrates or all SiC growth substrates are formed into an I-shape, an E-shape or a U-shape, wherein at least one SiC growth substrate or multiple SiC growth substrates or all SiC growth substrates are connected to a first metal electrode via a base unit (particularly a sealing wall member), and / or at least one SiC growth substrate and preferably multiple SiC growth substrates or all SiC growth substrates are formed into an I-shape, an E-shape or a U-shape, wherein at least one SiC growth substrate or multiple SiC growth substrates or all SiC growth substrates are connected to a second metal electrode via a base unit (particularly a sealing wall member). The benefit of this embodiment is that (particularly in terms of the U-shaped substrate): the length of the SiC growth substrate can be close to or approximately twice the length of the I-type substrate. In addition, the electrodes of the U-type SiC growth substrate can be mounted on the same wall member, in particular, on a base plate.

[0080] According to another preferred embodiment of the present invention, the inlet unit includes a plurality of holes for establishing a turbulent gas flow inside the process chamber (particularly within a distance of less than 20 mm, less than 10 mm, or less than 2 mm from the surface of the SiC growth substrate or the surface of SiC deposited on the SiC growth substrate). Due to the growth (particularly continuous growth) of the silicon carbide deposition surface, the area where turbulence must be maintained will change. The benefit of this embodiment is that turbulence can increase the deposition rate, and more Si and C materials can reach the surface of the SiC growth substrate or the SiC growth surface.

[0081] According to another preferred embodiment of the present invention, the control unit is configured to control the medium supply unit to supply one or more feed media into the process chamber, wherein the one or more feed media include the following molar ratio: Si:C, wherein Si=1 and C=0.8 to 1.1, or wherein the one or more feed media include the following atomic ratio: Si:C, wherein Si=1 and C=0.8 to 1.1. The advantage of this embodiment is that the required material ratio can be controlled and set. Therefore, a control unit is provided for setting the feed medium supply for feeding a feed medium and a carrier gas into the process chamber, wherein the control unit is preferably configured to control the medium supply unit to feed a feed medium into the process chamber at a defined molar ratio and / or a defined atomic ratio, wherein a feed medium and a carrier gas include the following defined molar ratio: Si:H, wherein Si=1 and H=2 to 10, preferably 5 to 10, more preferably 5 to 7, or wherein a feed medium and a carrier gas include the following defined atomic ratio: Si:H, wherein Si=1 and H= 2 to 10, preferably 5 to 10, more preferably 5 to 7, or a control unit for setting a feed medium supply of multiple feed media to the process chamber, wherein the control unit is configured to control the medium supply unit to supply the multiple feed media to the process chamber in a defined molar ratio and / or a defined atomic ratio, wherein the multiple feed media include the following defined molar ratio: Si:C, wherein Si=1 and C=0.8 to 1.1, or wherein the multiple feed media include the following defined atomic ratio: Si:C, wherein Si=1 and C=0.8 to 1.1.

[0082] According to another preferred embodiment of the present invention, the Si and C feed medium sources are coupled to at least one Si and C feed medium orifice of the inlet unit, and the carrier gas feed medium source is coupled to at least one carrier gas orifice of the inlet unit, wherein the Si and C feed medium orifice and the carrier gas orifice are preferably different from each other, or the Si and C feed medium source and the carrier gas feed medium source are coupled to at least one common mixing and / or guiding element (in particular a pipeline), wherein at least one common mixing and / or guiding element is coupled to at least one orifice of the inlet unit.

[0083] According to another preferred embodiment of the present invention, a Si and C supply device is provided for supplying Si and C feed media from Si and C feed medium sources through at least one orifice of the gas inlet unit into the reaction space, and / or a carrier gas supply device is provided for supplying carrier gas feed media from a carrier gas feed medium source through at least one orifice of the inlet unit into the reaction space, and / or a feed medium supply device is provided for supplying a mixture of Si and C feed media and carrier gas feed media from a common mixing and / or guiding element through at least one orifice of the inlet unit into the reaction space.

[0084] Alternatively, according to another preferred embodiment of the present invention, the Si feed medium source is coupled to at least one Si feed medium source orifice of the inlet unit, and wherein the coupled C feed medium source provides at least one C feed medium source orifice of the inlet unit, and wherein the carrier gas medium source is coupled to at least one carrier gas feed medium source orifice of the inlet unit, wherein the Si feed medium source orifice and / or the C feed medium source orifice and / or the carrier gas feed medium source orifice are different from each other, or the Si feed medium source and the C feed medium source are coupled to at least one common mixing and / or guiding element (in particular a pipe), wherein at least one common mixing and / or guiding element is coupled to at least one orifice of the inlet unit, or the Si feed medium source is coupled to at least one C feed medium source orifice of the inlet unit. The mass source and the carrier gas feed medium source are coupled to at least one common mixing and / or guiding element (especially a pipeline), wherein at least one common mixing and / or guiding element is coupled to at least one orifice of the inlet unit, or the C feed medium source and the carrier gas feed medium source are coupled to at least one common mixing and / or guiding element (especially a pipeline), wherein at least one common mixing and / or guiding element is coupled to at least one orifice of the inlet unit, or the Si feed medium source and the C feed medium source and the carrier gas feed medium source are coupled to at least one common mixing and / or guiding element (especially a pipeline), wherein at least one common mixing and / or guiding element is coupled to at least one orifice of the inlet unit.

[0085] According to another preferred embodiment of the present invention, a Si supply device is provided for supplying Si feed medium from a Si feed medium source through at least one orifice of the inlet unit into the reaction space, and / or a C supply device is provided for supplying C feed medium from a C feed medium source through at least one orifice of the inlet unit into the reaction space, and / or a carrier gas supply device is provided for supplying carrier gas from a carrier gas feed medium source through at least one orifice of the inlet unit into the reaction space. The Si supply device and / or the C supply device and / or the carrier gas supply device are preferably pumps, in particular pressure pumps.

[0086] According to another preferred embodiment of the present invention, at least one outlet unit or exhaust outlet is provided as part of the bell jar and / or as part of the base unit for removing gas from the reaction space. This embodiment is advantageous in that used gas can be exhausted from the process chamber and the content of Si and C is less affected by the exhaust gas that is not exhausted. According to another preferred embodiment of the present invention, a pump device is coupled to the outlet unit for removing gas from the reaction space, wherein the pump device is preferably a vacuum pump.

[0087] According to another preferred embodiment of the present invention, the Si feed medium source is configured to provide a Si feed medium with a purity of at least 6N, particularly 7N or preferably 8N or more preferably 9N, the C feed medium source is configured to provide a C feed medium with a purity of at least 6N, particularly 7N or preferably 8N or more preferably 9N, or the Si and C feed medium sources are configured to provide Si and C feed medium with a purity of at least 6N, particularly 7N or preferably 8N or more preferably 9N, and the carrier gas feed medium source is configured to provide a carrier gas feed medium with a purity of at least 6N, particularly 7N or preferably 8N or more preferably 9N. Therefore, at least a first feed medium (particularly a first source gas) is introduced into the process chamber, the first feed medium comprising Si, wherein the purity of the first feed medium excludes at least 99.99999% (ppm wt) of the following substances: B, Al, P, Ti, V, Fe, Ni (particularly excluding one or preferably multiple or more preferably most or most preferably all of the following substances: B, Al, P, Ti, V, Fe, Ni), and at least a second feed medium (particularly a second source gas) is introduced into the process chamber, the second feed medium comprising C, wherein the purity of the second feed medium excludes at least 99.99999% (pp mwt) of the following substances: B, Al, P, Ti, V, Fe, Ni (particularly excluding one or preferably multiple or more preferably most or most preferably all of the following substances: B, Al, P, Ti, V, Fe, Ni), and a carrier gas is introduced, wherein the purity of the carrier gas excludes at least 99.99999% (ppm wt) of the following substances: B, Al, P, Ti, V, Fe, Ni (especially excluding one or preferably multiple or more preferably most or most preferably all of the following substances: B, Al, P, Ti, V, Fe, Ni), or introducing a feed medium (especially source gas) into the process chamber, the feed medium comprising Si and C, wherein the purity of the feed medium excludes at least 99.99999% (ppm wt) of the following substances: B, Al, P, Ti, V, Fe, Ni (especially excluding one or preferably multiple or more preferably most or most preferably all of the following substances: B, Al, P, Ti, V, Fe, Ni), and introducing a carrier gas, wherein the purity of the carrier gas excludes at least 99.99999% (ppm wt) of the following substances: B, Al, P, Ti, V, Fe, Ni (especially excluding one or preferably multiple or highly preferably most or most preferably all of the following: substances B, Al, P, Ti, V, Fe, Ni). Thus, the present invention discloses a CVD reactor for producing SiC source material having a purity of at least 8N or preferably 9N when initially manufactured and preferably provided in particulate or solid form to minimize subsequent surface contamination during handling and use.This ultrapure SiC source material (UPSiC) is made by a CVD reactor process, in which the feed gas used can be purified to extremely high levels using effective techniques such as distillation. SiC or PVT source material SiC (especially UPSiC) is usually first deposited in the form of long and thick rods, and then decomposed (especially cut or crushed) to form a shape or size suitable for use in a PVT crucible. The crushing equipment is preferably made of a material that will not contaminate the SiC, and an etching step can be further performed to remove fine particles and ensure surface purity. The benefit of this embodiment is that large and high-purity particles with favorable sublimation properties can be produced. If an etching step is used, only a few atomic layers (less than 1μm, while 10-50μm in Si etching) will be removed, especially under the action of HF / HNO3. This is beneficial because the bluish brown color after annealing can be removed due to etching. In addition or alternatively, an acidic pickling acid (for example composed of HCl:HF:H2O2 and / or different acid mechanisms) can also be used to remove the oxide layer.

[0088] Chemical vapor deposition occurs when a deposition substrate or SiC growth substrate is heated to a deposition temperature range and a feed gas mixture is introduced into a CVD reactor or SiC production reactor (particularly a SiC PVT source material production reactor). When the feed gas mixture contacts the heated deposition substrate, the energy provided initiates a series of forward and reverse chemical reactions, with the net result being the deposition of solid SiC on the deposition substrate. In the case where the feed gas mixture includes SiCl4 (where SiCl4 may be named STC) and methane, the net reaction may be summarized as follows:

[0089] SiCl4+CH4=SiC+4HCl

[0090] It should be noted that not every Si-containing molecule and C-containing molecule will contact the deposition surface and undergo a deposition reaction. Therefore, it is preferred to pump the feed gas at a higher rate than the feed gas is deposited as SiC on the substrate. For example, if X moles of SiC are deposited per square centimeter of deposition surface per hour, it may be necessary to pump AX moles of Si and AX moles of C into the CVD reactor or SiC production reactor (particularly SiC PVT source material production reactor) per hour, respectively, where A is in the range of between 8 and 10. The lower A is, the higher the conversion efficiency from feed gas to deposited SiC. By optimizing the gas flow in the CVD reactor or SiC production reactor (particularly SiC PVT source material production reactor), the feed gas mixture is maximized in contact with the deposition surface, thereby improving efficiency.

[0091] According to another preferred embodiment of the present invention, the surface of the base unit defining the reaction space and the top surface portion of the bell jar surface defining the reaction space are arranged at a first distance interval, wherein the top surface portion of the bell jar surface is arranged at the farthest distance from the base unit surface in the height direction, wherein the first distance is the farthest distance, and wherein the SiC growth substrate or the SiC growth substrate extends a second distance in the height direction, wherein the second distance is less than 90% of the height of the first distance, or the second distance is less than 85% of the height of the first distance, or the second distance is less than 80% of the height of the first distance, or the second distance is less than 75% of the height of the first distance, or the second distance is less than 70% of the height of the first distance, or wherein the SiC growth substrate or the SiC growth substrate extends a second distance in the height direction, wherein, compared with the second distance, the first distance is at most 10% higher, or at most 20% higher, or at most 30% higher, or at most 50% higher. According to another preferred embodiment of the present invention, the first distance is greater than or up to or exactly 100 cm or preferably greater than or up to or exactly 130 cm or greater than or up to or exactly 150 cm or more preferably greater than or up to or exactly 170 cm or greater than or up to or exactly 200 cm or greater than or up to or exactly 250 cm or greater than or up to or exactly 300 cm, and / or the inner diameter of the reaction space is greater than 50 cm or greater than or up to or exactly 70 cm or greater than or up to or exactly 100 cm or preferably greater than or up to or exactly 120 cm or more preferably greater than or up to or exactly 150 cm. This embodiment is beneficial in that large SiC growth substrates can be used in the SiC production reactor, thereby improving production efficiency.

[0092] According to another preferred embodiment of the present invention, the interface between the bell jar and the base unit comprises a seal, wherein the seal is configured to withstand a pressure of more than 1 bar, in particular more than 2 bar or more than 5 bar, more preferably between 1 and 20 bar. This embodiment is beneficial in that a high feed medium density can be generated in the process chamber, thereby providing a beneficial Si and C supply for the SiC growth substrate.

[0093] According to another preferred embodiment of the present invention, the bell jar (in particular the surface of the bell jar defining the reaction space) and / or the base unit (in particular the surface of the bottom plate defining the reaction space) are configured to withstand chemical treatment (in particular caustic soda), in particular chemical treatment for at least 30 seconds or at least 60 seconds or at least 5 minutes. This embodiment is beneficial in that the bell jar can be cleaned separately for reuse.

[0094] According to another preferred embodiment of the present invention, the SiC growth substrate is configured to accommodate a SiC solid having a mass greater than 1 kg, in particular greater than or up to 5 kg, or preferably greater than or up to 50 kg, or more preferably greater than or up to 200 kg, and most preferably greater than or up to 500 kg, and a thickness of at least 1 cm, in particular greater than or up to 2 cm, or preferably greater than or up to 5 cm, or preferably greater than or up to 10 cm, or more preferably greater than or up to 20 cm, or most preferably greater than or up to 50 cm. This embodiment is advantageous in that a large amount of SiC material or PVT source material can be produced.

[0095] According to another preferred embodiment of the present invention, the reaction space volume allows the simultaneous production of one or more SiC solids, wherein the mass of the SiC solid is greater than 1 kg, in particular greater than or up to 5 kg, or preferably greater than or up to 50 kg, or more preferably greater than or up to 200 kg, most preferably greater than or up to 500 kg, and the thickness of the SiC solid is at least 1 cm, in particular greater than or up to 2 cm, or preferably greater than or up to 5 cm, or preferably greater than or up to 10 cm, or more preferably greater than or up to 20 cm, or most preferably greater than or up to 50 cm, or wherein the mass of multiple or all SiC solids is greater than 1 kg, in particular greater than or up to 5 kg, or preferably greater than or up to 50 kg, or more preferably greater than or up to 200 kg, most preferably greater than or up to 500 kg, and the thickness of multiple or all SiC solids is at least 1 cm, in particular greater than or up to 2 cm, or preferably greater than or up to 5 cm, or preferably greater than or up to 10 cm, or more preferably greater than or up to 20 cm, or most preferably greater than or up to 50 cm. The advantage of this embodiment is that a large amount of SiC material or PVT source material can be produced.

[0096] According to another preferred embodiment of the present invention, the SiC growth substrate is preferably an elongated single-component substrate. The single-component substrate preferably comprises a plurality of parts having the same or similar diameter and / or the same or similar cross-sectional shape. The diameter (particularly the diameter orthogonal to the current flow direction) is the same or similar along at least 50% of the length of the single-component substrate, preferably at least 70% along the length of the single-component substrate, more preferably at least 90% along the length of the single-component substrate, and most preferably at least 95% along the length of the single-component substrate. Here, similar means that the maximum diameter is less than 200% of the minimum diameter, preferably the maximum diameter is less than 150% of the minimum diameter, more preferably the maximum diameter is less than 110% of the minimum diameter, and most preferably the maximum diameter is less than 105% of the minimum diameter. According to another preferred embodiment of the present invention, the SiC growth substrate is a multi-component substrate, wherein the multi-component substrate comprises at least two elongated substrate parts, wherein at least two elongated (particularly straight and / or curved) substrate parts are arranged in a row and preferably in direct contact with each other (particularly via end face contact). At least one substrate portion is preferably curved along the current flow direction, and more preferably two or more substrate portions are curved. The diameters of the substrate portions (especially the straight and / or curved substrate portions) perpendicular to the current flow direction are preferably the same, or the maximum diameter is less than 200% of the minimum diameter, or preferably less than 150% of the minimum diameter, or more preferably less than 110% of the minimum diameter, and most preferably less than 105% of the minimum diameter. According to another preferred embodiment of the present invention, the SiC growth substrate comprises three or more substrate portions, wherein the substrate portion contact surfaces between the contacting substrate portions have the same or similar shape and / or the same or similar size, wherein similar size means that the maximum surface size of the substrate portion contact surface is less than 200% of the surface size of the minimum substrate portion contact surface, or preferably the maximum surface size of the substrate portion contact surface is less than 150% of the surface size of the minimum substrate portion contact surface, or more preferably the maximum surface size of the substrate portion contact surface is less than 110% of the surface size of the minimum substrate portion contact surface, or more preferably the maximum surface size of the substrate portion contact surface is less than 105% of the surface size of the minimum substrate portion contact surface.

[0097] According to another preferred embodiment of the present invention, the SiC growth substrate has a certain length, wherein the SiC growth substrate is at least indirectly coupled to one or at least one first metal electrode through a first end, and is 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. The length of the SiC growth substrate is preferably defined as the physical extension of the center of the SiC growth substrate in the direction of current flow.

[0098] It should be noted that the total deposition surface area within a CVD reactor or SiC production reactor (particularly a SiC PVT source material production reactor) will gradually increase over time as the deposits on the SiC growth substrate increase and the circumference of the SiC growth substrate increases. The SiC growth substrate can be a thin rod, preferably at least 1.0 cm in diameter and up to 250 cm in height, for example. For example, when the diameter of the SiC growth substrate reaches 10 cm due to the deposited SiC, their total surface area will be proportionally 10 times larger than when it was initially. Therefore, it is also necessary to increase the total feed gas mixture flow rate to match the increase in volume deposition rate during the deposition process.

[0099] The SiC growth substrate can accumulate a layer of deposits to a total diameter of, say, 20 cm. At this point the circumference is about 60 cm, and if the vertical deposition rate is 1 mm per hour, the volumetric deposition rate per 1 cm of rod height is 6 cubic centimeters per hour. However, because the starting diameter of the thin rods is so small, the average volumetric deposition rate over the entire run is actually closer to 3 cubic centimeters per centimeter per hour.

[0100] According to the present invention, the average volume deposition rate can be increased by using a deposition substrate or SiC growth substrate with a larger starting surface area. The surface area per centimeter height of a thin rod with a diameter of 1 cm is about 3 square centimeters, while the starting surface area per centimeter height of a thin strip-shaped deposition substrate with a width of 10 cm is 20 square centimeters, which greatly increases the average volume deposition rate and can deposit the same amount of SiC in a shorter operating time. Therefore, the CVD reactor or SiC production reactor (especially the SiC PVT source material production reactor) can perform more operations per year. Therefore, fewer CVD reactors or SiC production reactors (especially the SiC PVT source material production reactor) are required to manufacture the same total tonnage of SiC. Therefore, a preferred embodiment of the present invention is to use a deposition substrate with a high starting surface area.

[0101] According to another preferred embodiment of the present invention, the average perimeter of the SiC growth substrate around the cross-sectional area orthogonal to the length direction of the SiC growth substrate is at least 5 cm, preferably at least 7 cm, more preferably at least 10 cm, or the average perimeter of each SiC growth substrate around the cross-sectional area orthogonal to the length direction of the respective SiC growth substrate is at least 5 cm, preferably at least 7 cm, more preferably at least 10 cm. The average perimeter of the SiC growth substrate is preferably up to 25 cm, or preferably up to 50 cm, or more preferably up to 100 cm. The average perimeter of the SiC growth substrate is preferably between 5 cm and 100 cm, preferably between 6 cm and 50 cm, more preferably between 7 cm and 25 cm, most preferably between 7.5 cm and 15 cm, or wherein the average perimeter of the SiC growth substrate is between 5 cm and 20 cm, preferably between 5 cm and 15 cm, more preferably between 5 cm and 12 cm. The benefit of this embodiment is that a longer perimeter can produce a higher volume growth. Therefore, the same amount of SiC can be produced faster.

[0102] According to another preferred embodiment of the present invention, the SiC growth substrate comprises or consists of SiC or C (especially graphite), or a plurality of SiC growth substrates comprise or consist of SiC or C (especially graphite). Therefore, graphite and carbon-carbon composite materials are preferred materials for deposition substrates of SiC. Graphite and carbon-carbon composite materials can be easily separated from SiC by mechanical means and combustion, and the residual C on SiC will not impair the performance of SiC as a single crystal SiC PVT growth source material at the ppm level. However, the residual C on the surface of SiC can also be removed.

[0103] According to another preferred embodiment of the present invention, the shape of the cross section of the SiC growth substrate in a direction orthogonal or perpendicular to the length direction is different from a circle at least partially and preferably within a range of 50% along the length of the SiC growth substrate, and more preferably within a range of 90% along the length of the SiC growth substrate.

[0104] According to another preferred embodiment of the present invention, the ratio (U / A) between the cross-sectional area (A) and the perimeter (U) around the cross-sectional area is higher than 1.2 1 / cm, preferably higher than 1.5 1 / cm, more preferably higher than 2 1 / cm, and most preferably higher than 2.5 1 / cm. The benefit of this embodiment is that the high ratio (U / A) enables a higher volume growth.

[0105] The above object is also achieved by a method according to claim 20. The method according to claim 20 is a method of growing SiC, in particular growing SiC on a SiC growth substrate, in particular growing SiC on a SiC growth substrate according to claims 1 to 17. The method preferably comprises the steps of increasing the current flowing through the SiC growth substrate over time to keep the temperature of the growth face within a defined temperature range, depositing SiC on the SiC growth substrate to form a SiC shell, growing the SiC shell to a thickness greater than 1 cm, in particular greater than 3 cm or greater than 5 cm or more preferably greater than 10 cm, preventing the defined volume portion of the SiC growth substrate from cracking during the growing step by means of the physical structure of the body.

[0106] According to another preferred embodiment of the aforementioned method, a step of providing a source medium in the process chamber is provided, wherein the step of providing a source medium in the process chamber comprises: introducing at least a first feed medium (particularly a first source gas) into the process chamber, wherein the first feed medium comprises Si, wherein the purity of the first feed medium excludes at least 99.9999% (ppm wt) of the following substances: B, Al, P, Ti, V, Fe, Ni; and introducing at least a second feed medium (particularly a second source gas) into the process chamber, wherein the second feed medium comprises C, particularly natural gas, methane, ethane, propane, butane and / or acetylene, wherein the purity of the second feed medium excludes at least 99.9999% (ppm wt) of the following substances: B, Al, P, Ti, V, Fe, Ni; and introducing a carrier gas, wherein the purity of the carrier gas excludes at least 99.9999% (ppm wt) of the following substances: wt) of the following substances: B, Al, P, Ti, V, Fe, Ni, or a feed medium (especially source gas) is introduced into the process chamber, wherein the feed medium includes Si and C, especially includes SiCl3 (CH3), wherein the purity of the feed medium excludes at least 99.9999% (ppmwt) of the following substances: B, Al, P, Ti, V, Fe, Ni, and a carrier gas is introduced, wherein the purity of the carrier gas excludes at least 99.9999% (ppmwt) of the following substances: B, Al, P, Ti, V, Fe, Ni.

[0107] Further advantages, objects and features of the invention will be explained with reference to the following description of the drawings, in which the device according to the invention is shown by way of example. Parts or elements of the device or reactor or system or SiC growth substrate according to the invention, which at least substantially correspond in function in the drawings, may be marked with the same reference numerals, so that these parts or elements do not have to be numbered or explained in all drawings.

[0108] Each or all of the figures described below are preferably regarded as structural drawings, that is, the dimensions, proportions, functional relationships and / or arrangements in one or more figures preferably completely correspond or preferably basically correspond to the dimensions, proportions, functional relationships and / or arrangements of the device according to the present invention, the product according to the present invention, or the method according to the present invention.

[0109] The above object is also achieved by a method for growing SiC according to claim 17, in particular by a method for growing SiC on a SiC growth substrate according to claims 1 to 12. The method according to the present invention preferably comprises at least the following steps:

[0110] increasing over time an alternating current through the SiC growth substrate to maintain the temperature of the growth face within a defined temperature range, wherein the frequency of the alternating current is higher than 5 Hz or preferably higher than 20 Hz or more preferably higher than 50 Hz or most preferably higher than 500 Hz or up to 5000 Hz, in particular up to 2000 Hz or up to 1000 Hz or up to 500 kHz,

[0111] Depositing SiC on a SiC growth substrate to form a SiC shell,

[0112] The SiC shell is grown to a thickness of more than 1 cm, and the defined volume portion of the SiC growth substrate is prevented from cracking during the growth step by the body. The body is preferably formed of a carbon fiber composite material, wherein the body formed of the carbon fiber composite material has a tensile strength higher than 20 MPa and / or a flexural strength higher than 20 MPa, in particular higher than 20 MPa but lower than 50 MPa or lower than 70 MPa, wherein the body is at least partially and preferably more than 50% along the length (ML) of the body and most preferably completely in a ribbon-like shape, wherein the ribbon-like shape forms a cross-section with a width (W) and a depth (D), wherein the width (W) is at least 2 times and preferably at least 3 times and more preferably at least 5 times and most preferably up to 10 times or exactly 10 times or more than 10 times the depth (D), wherein the width (W) is less than 1.5 cm and the depth (D) is greater than 3.0 cm. The benefit of this solution is that the use of an alternating current reduces the thermal mismatch during growth to less than 300 K, thereby greatly reducing the tension inside the shell or body. Therefore, the tensile strength and / or flexural strength of the body can be lower. This is beneficial because lower tensile strength and / or flexural strength can reduce costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0113] The figure shows:

[0114] Figure 1 A first example of a CVD reactor according to the invention is schematically shown,

[0115] Figure 2 A second example of a CVD reactor according to the invention is schematically shown,

[0116] Figure 3 A third example of a CVD reactor according to the invention is schematically shown,

[0117] Figure 4a-4g The SiC growth substrate is schematically shown, in particular Figure 1 , Figure 2 or Figure 3 Example of SiC growth substrate in a CVD reactor,

[0118] Figure 5a-5e The SiC growth substrate is schematically shown, in particular Figure 1 , Figure 2 or Figure 3 Example of SiC growth substrate for CVD reactor,

[0119] Figure 6a / Figure 6b Schematically shows an example of a blade-shaped SiC growth substrate, in particular Figure 1 , Figure 2 or Figure 3 Example of blade-shaped SiC growth substrate for CVD reactor,

[0120] Figure 6c / Figure 6d Schematically shows an example of a tubular SiC growth substrate, in particular Figure 1 , Figure 2 or Figure 3 Example of a tubular SiC growth substrate for a CVD reactor.

[0121] Figure 7a-7c schematically shows an example of a growth substrate with crack-free regions, and

[0122] Figure 7d schematically shows an example of a cross-sectional view of a rod-shaped growth substrate, and

[0123] Figure 8a-9d An example of a carbon fiber composite element is schematically shown. DETAILED DESCRIPTION

[0124] Figure 1An example of a manufacturing device 850 for producing SiC material, especially 3C-SiC material is shown. This device 850 includes a first feed device 851, a second feed device 852 and a third feed device 853. The first feed device 851 is preferably designed as a first mass flow controller, which is particularly used to control the mass flow rate of a first source fluid (especially a first source liquid or a first source gas), wherein the first source fluid preferably includes Si, especially includes, for example, silane / chlorosilane with a general composition of SiH4-mClm, or an organic chlorosilane with a general composition of SiR4-mClm (wherein R = hydrogen, hydrocarbon or chlorocarbon). The second feed device 852 is preferably designed as a second mass flow controller, which is particularly used to control the mass flow rate of a second source fluid (especially a second source liquid or a second source gas), wherein the second source fluid preferably includes C, such as a hydrocarbon or a chlorocarbon, preferably with a boiling point of less than 100°C, and particularly preferably methane. The third feeding device 853 is preferably designed as a third mass flow controller, which is particularly used to control the mass flow rate of the carrier fluid (especially the carrier gas), wherein the carrier fluid or the carrier gas preferably includes H or H2, or a mixture of hydrogen and an inert gas, respectively.

[0125] Reference numeral 854 denotes a mixing device or mixer, by which a source fluid and / or a carrier fluid can be mixed with one another, in particular in a predetermined ratio. Reference numeral 855 denotes an evaporator device or evaporator, by which a fluid mixture supplied from the mixing device 854 to the evaporator device 855 can be evaporated.

[0126] The evaporated fluid mixture is then transported to a process chamber 856 or a separation container, which is designed as a pressure vessel. At least one deposition element 857, preferably a plurality of deposition elements 857, is arranged in the process chamber 856, wherein Si and C are deposited from the evaporated fluid mixture at the deposition element 857 and form SiC.

[0127] Reference numeral 858 denotes a temperature measuring device which is preferably used to determine the surface temperature of the deposition element 857 and which is preferably connected to a control device (not shown) via data and / or signal technology.

[0128] Reference numeral 859 denotes an energy source, which is used in particular to introduce electrical energy into the separation element 857 to heat the separation element. The energy source 859 is preferably also connected to the control device in terms of signals and / or data. Preferably, the control device controls the energy supply (in particular the power supply) through the deposition element 857 based on the measurement signal and / or measurement data output by the temperature measuring device 858. The energy source 859 preferably provides an alternating current.

[0129] Furthermore, a pressure maintaining device is indicated by reference numeral 860. The pressure maintaining device 860 can preferably be realized by a pressure regulating valve or the operating pressure of a downstream exhaust gas treatment system.

[0130] Figure 2 A CVD unit or CVD reactor or SiC production reactor (particularly SiC PVT source material production reactor 850) of a preferred embodiment of the present invention is shown. The CVD unit or CVD reactor or SiC production reactor (particularly SiCPVT source material production reactor 850) preferably comprises a steel upper shell 202 or bell jar cooled by a fluid (particularly oil or water), which is sealed with a lower shell 2040 or bottom plate preferably cooled by a fluid (particularly oil or water) by one or more gaskets, thereby forming a deposition chamber or process chamber 856, and the pressure of the deposition chamber or process chamber 856 is preferably at least 6 bar, especially between 2 bar and 15 bar. The feed gas mixture 1160 preferably enters the deposition chamber or process chamber 856 through a plurality of feed gas inlets 2140, and the exhaust gas 2120 is preferably discharged through a gas outlet unit or exhaust outlet 216. A plurality of resistive self-heating deposition substrates or SiC growth substrates 857 (preferably made of graphite or silicon carbide or metal) are preferably arranged in the deposition chamber, and the deposition substrates or SiC growth substrates 857 are connected to a chuck 208 preferably made of graphite. The chuck 208 is also connected to a water-cooled electrode 206, which is preferably made of copper passing through the substrate so that they can be connected to an external power source. The deposition substrates or SiC growth substrates 857 are preferably arranged in pairs through a cross member 203 to complete the resistive heating circuit.

[0131] The purpose of the chuck 208 is to form a temperature gradient between the electrode 206 (preferably in the temperature range of 850°C to 400°C) and the deposition substrate or SiC growth substrate 857 (preferably in the temperature range of 1300°C to 1600°C). The chuck 208 preferably achieves this temperature gradient by continuously reducing the cross-sectional area of ​​current flow, thereby generating increasingly higher resistance heating. Therefore, the chuck 208 preferably has a conical shape. In this way, the starting point of the deposition of the CVD SiC shell 211 can be preferably controlled (e.g., the middle of the chuck 208), so that the final deposition substrate or SiC growth substrate 857 has a structurally strong connection with the deposited CVD SiC shell 221 at the bottom and does not crack or collapse.

[0132] The plurality of feed gas inlets 2140 are preferably designed to produce a turbulent gas flow pattern within the deposition chamber or process chamber 856 so as to maximize the contact of fresh feed gas with the surface of the CVD SiC shell 211 deposited on the deposition substrate or SiC growth substrate 857. Additionally or alternatively, a gas turbulence generating device may be provided, particularly within the process chamber. The gas turbulence generating device may be a ventilator or a circulation pump. This ensures that a given amount of CVD SiC shell 211 is produced using a minimum excess of feed gas mixture 1160. The exhaust gas 2120, which contains the unreacted feed gas mixture and the changed Si-containing gas and HCl gas, is forced out of the deposition chamber or process chamber 856 through the exhaust outlet by the incoming feed gas mixture 1160.

[0133] Figure 3 An example of a method for controlling temperature and pressure of a CVD cell is shown. A temperature control unit or temperature measuring device 858 is positioned to measure the temperature of the CVD SiC shell 211 along the temperature measurement path 209, preferably through a sight glass 213, which is preferably cooled by a fluid (particularly oil or water). The temperature control unit or temperature measuring device 858 preferably measures the surface temperature of the CVD SiC shell and sends a signal to a power supply unit or energy source 859 to increase or decrease the power of the deposition substrate or SiC growth substrate 857, depending on whether the temperature is below or above the required temperature. The power supply unit or energy source 859 is wired to the electrode 206 cooled by the fluid (particularly oil or water) and adjusts the voltage and / or current of the electrode 206 cooled by the fluid (particularly oil or water) accordingly. The energy source 859 preferably provides an alternating current. The deposition substrates or SiC growth substrates 857 are wired in pairs, respectively, and have connecting cross members at the top to form a complete circuit for current flow.

[0134] The pressure within the deposition or process chamber 856 is regulated by a pressure control unit or pressure maintaining device 860 , which senses the pressure and reduces or increases the flow rate of the exhaust gas 2120 from the deposition or process chamber 856 .

[0135] Therefore, if Figure 2 and Figure 3As shown, the SiC production reactor 850 according to the present invention preferably includes at least one process chamber 856, wherein the process chamber 856 is surrounded by at least a bottom plate 862, a side wall portion 864a and a top wall portion 864b. The reactor 850 preferably includes a gas inlet unit 866 for feeding one or more feed media into the reaction space of the process chamber 856 to generate a source medium in the process chamber 856. The bottom plate 862 preferably includes at least one cooling element 868, 870, 880 (particularly a base cooling element) for preventing the bottom plate 862 from being heated to a temperature exceeding a defined temperature, and / or wherein the side wall portion 864a preferably includes at least one cooling element 868, 870, 880 (particularly a bell cooling element) for preventing the side wall portion 864a from being heated to a temperature exceeding a defined temperature, and / or wherein the top wall portion 864b preferably includes at least one cooling element 868, 870, 880 (particularly a bell cooling element) for preventing the top wall portion 864b from being heated to a temperature exceeding a defined temperature. The cooling element 868 may be an active cooling element 870, so the bottom plate 862 and / or the side wall portion 864a and / or the top wall portion 864b preferably include a cooling fluid guiding unit 872, 874, 876 for guiding the cooling fluid, wherein the cooling fluid guiding unit 872, 874, 876 is configured to limit the heating of the bottom plate 862 and / or the side wall portion 864a and / or the top wall portion 864b to a temperature below 1000° C. In addition, a bottom plate and / or side wall portion and / or top wall portion sensor unit 890 may be provided to detect the temperature of the bottom plate 862 and / or the side wall portion 864a and / or the top wall portion 864b and output a temperature signal or temperature data. At least one bottom plate and / or side wall portion and / or top wall portion sensor unit 890 may be arranged as part of a surface or on a surface within the process chamber, in particular on a surface of the bottom plate 862 or the side wall portion 864a or the top wall portion 864b. Additionally or alternatively, one or more bottom plate and / or side wall portion and / or top wall portion sensor units 890 may be provided in the bottom plate 862 or in the side wall portion 864a or in the top wall portion 864b. Additionally or alternatively, a cooling fluid temperature sensor 820 may be provided to detect the temperature of the cooling fluid guided by the cooling fluid guiding unit 870. A fluid delivery unit 873 may be provided to deliver the cooling fluid through the fluid guiding units 872, 874, 876, wherein the fluid delivery unit 873 is preferably configured to operate according to a temperature signal or temperature data provided by the bottom plate and / or side wall portion and / or top wall portion sensor unit 890 and / or the cooling fluid temperature sensor 892. The cooling fluid may be oil or preferably water, wherein the water preferably comprises at least one additive, in particular a corrosion inhibitor and / or an antifouling agent (biocide).

[0136] Additionally or alternatively, the cooling element 868 is a passive cooling element 880. Thus, the cooling element 868 may be at least partially formed by a polished steel surface 865 of the bottom plate 862, the side wall portion 864a and / or the top wall portion 864b, preferably by a polished steel surface 865 of the bottom plate 862, the side wall portion 864a and the top wall portion 864b. The passive cooling element 868 may be a coating 867, wherein the coating 867 is preferably formed over the polished steel surface 865 and the coating 867 is configured to reflect heat. The coating 867 may be a metal coating or include a metal, in particular silver or gold or chromium, or may be an alloy coating, in particular a CuNi alloy coating. The emissivity of the polished steel surface 865 and / or the coating 867 is 0.3, in particular lower than 0.1, more preferably lower than 0.03.

[0137] The base plate 862 may include at least one active cooling element 870 and one passive cooling element 880 for preventing the base plate 862 from being heated above a defined temperature, and / or the side wall portion 864a may include at least one active cooling element 870 and one passive cooling element 880 for preventing the side wall portion 864a from being heated above a defined temperature, and / or the top wall portion 864b may include at least one active cooling element 870 and one passive cooling element 880 for preventing the top wall portion 864b from being heated above a defined temperature.

[0138] The side wall portion 864a and the top wall portion 864b are preferably formed by a bell 864, wherein the bell 864 is preferably movable relative to the bottom plate 862.

[0139] Figure 4a A first multi-component SiC growth substrate 857 is shown. Thus, there may be at least two or exactly two first type components 2224a, which define the length of the SiC growth substrate 857. The SiC growth substrate 857 is preferably formed in a "U-shape". This "U-shape" is preferably characterized by a first leg 2232 and a second leg 2234 and a connecting portion 2236 for connecting the first leg 2232 and the second leg 2234. The first leg 2232 is preferably formed opposite to the second leg 2234. However, it is also possible that the first leg 2232 is formed by a first type of main component and the second leg is formed by a second type of main component. Additionally or alternatively, the first leg 2232 includes a first number of components 2224a and / or 2224b, and the second leg 2234 includes a second number of components 2224a and / or 2224b. The same applies to other multi-component SiC substrates 857 disclosed herein.

[0140] Figure 4b Another example of another multi-component SiC growth substrate 857 is shown. Figure 4aIn contrast to the SiC growth substrate 857 , the present SiC growth substrate 857 includes a first leg 2232 and a second leg 2234 , wherein each leg 2232 / 2234 includes two or more first type components 2224 a and two or more second type components 2224 b .

[0141] Figure 4c Another example of another multi-component SiC growth substrate 857 is shown. According to this example, the various components 2224a can be arranged at angles other than 90° or 180°.

[0142] Figure 4d Schematically showing two components 2224a of the first type, preferably, the two components 2224a can be arranged so that the central axis 2226 of one component and the central axis 2228 of the other component are at a certain distance from each other, in particular, greater than 8cm or greater than 12cm or greater than 15cm. The central axes 2226, 2228 are preferably arranged parallel to each other.

[0143] Figure 4e Another example of a multi-component SiC growth substrate 857 is shown. A first type component 2224a can be coupled by a second type component 2224b, wherein the diameter of the second type component 2224b is preferably large enough so that at least a portion of the surface around the central axis of the second type component 2224b surrounds the central axis at a distance of 0.5 times the diameter. This embodiment is beneficial in that the deposition of SiC can be prevented or limited to avoid the formation of a SiC shell on the circumferential surface of the connecting component 2224b.

[0144] Figure 4f An example of how two components 2224a are coupled via a large diameter connecting component 2224b is schematically shown.

[0145] Figure 4gAn example of an elongated non-SiC substrate 2223 (e.g., graphite) is schematically shown, wherein a surface cooling element 2238 is coupled to the elongated non-SiC substrate 2223. The length of the elongated non-SiC substrate 2223 is preferably greater than 25 cm, particularly preferably greater than 50 cm, more preferably 75 cm, and most preferably greater than 100 cm, or the length is between 50 cm and 200 cm, especially between 60 cm and 150 cm. The diameter of the surface cooling element 2238 is preferably greater than 1.3 times the diameter of the elongated non-SiC substrate 2223, preferably greater than 1.5 times the diameter of the elongated non-SiC substrate 2223, more preferably greater than 2 times the diameter of the elongated non-SiC substrate 2223, and most preferably greater than 2.5 times the diameter of the elongated non-SiC substrate 2223. The surface cooling element 2238 is preferably made of graphite or preferably includes graphite. The surface cooling element 2238 can be a single-component element or can be made of multiple components (especially two or more components). The surface cooling element 2238 may be attached to the elongated non-SiC substrate 2223 by adhesive connection and / or force fit and / or form fit.

[0146] Figure 5a-5d Shows Figure 4a , Figure 4b , Figure 4c and Figure 4e The SiC growth substrate 857 shown in the does not have to be in a "U" shape, as it can also be made into different shapes. Another preferred form is an example of an "I" shape. According to the "I", the electrical connections are arranged on opposite sides of the reaction space 966. In addition, the SiC growth substrate 857 can be formed in an "N" shape, an "M" shape, or a "W" shape, wherein preferably each SiC growth substrate provides only two electrical connections, which are particularly located at the ends of the corresponding substrate (in a manner similar to the "U" shape).

[0147] Figure 5e A SiC growth substrate 857 is shown as a single component 2222. The single component SiC growth substrate 857 can be solid or hollow. Thus, the single component SiC growth substrate 857 can be formed as a solid rod 2218 or tube. The single component SiC growth substrate 857 can be made of SiC or graphite.

[0148] Figure 6a An example of a blade-shaped or ribbon-shaped 2214 SiC growth substrate 857 is schematically shown. The SiC growth substrate 857 can be a single component or formed from multiple components. The SiC growth substrate 857 preferably includes graphite or carbon fiber. The SiC growth substrate 857 is more preferably made of one or more carbon fiber composite elements 2242.

[0149] Figure 6b Schematically shows Figure 6aA cross-sectional view of a blade-shaped or ribbon-shaped 2214SiC growth substrate 857. Figure 6b As can be seen from the figure, the width W is several times the depth D. The depth D is preferably less than 0.5 cm, in particular less than 0.2 cm, or between 0.01 cm and 0.15 cm. The width W is preferably greater than 3 cm, more preferably greater than 10 cm, and most preferably greater than 15 cm. Such a W / D ratio is very beneficial because a large amount of SiC can be deposited immediately after starting a production run.

[0150] Figure 6c An example of a tubular 2220 SiC growth substrate 857 is schematically shown. The SiC growth substrate 857 can be a single component or formed from multiple components. The SiC growth substrate 857 preferably comprises graphite or carbon fiber. The SiC growth substrate 857 is more preferably made of one or more carbon fiber composite elements 2242.

[0151] Figure 6d Schematically shows Figure 6c A cross-sectional view of a blade-shaped or ribbon-shaped 2220SiC growth substrate 857. Figure 6d It can be seen that the diameter of the tube is preferably several times the thickness of the tube wall, in particular greater than 2.5 times, or preferably greater than 3 times, or more preferably greater than 4 times, most preferably greater than 5 times.

[0152] Figure 7a-7c Different examples of SiC growth substrates 857 according to the present invention are shown. In each of the figures, a region where crack-free material is formed is defined. The region is formed between a first plane 2204 and a second plane 2206, wherein the first plane 2204 and the second plane 2206 are parallel to each other and are at a distance 2208 from each other. The distance 2208 is preferably greater than 1 cm, preferably greater than 2 cm, more preferably greater than 5 cm, most preferably greater than 10 cm, or the distance is between 1.5 cm and 50 cm, in particular between 2 cm and 25 cm or between 2.2 cm and 15 cm.

[0153] Figure 7a Carbon fibers 2210 are shown, wherein the carbon fibers 2210 are preferably aligned in different directions to form a carbon fiber composite material 2212 .

[0154] Figure 7d Schematically shows Figure 7c An example of a cross-sectional view of a rod-shaped 2218SiC growth substrate 857 in FIG.

[0155] Thus, the present invention relates to a SiC growth substrate 857 for growing SiC in a CVD reactor 850. The SiC growth substrate 857 preferably includes at least a body 2200, a first power connection 859a and a second power connection 859b, wherein the body 2200 has a body length ML, wherein the body length ML extends between the first power connection 859a and the second power connection 859b. The first power connection 859a is preferably configured to conduct power into the body 2200 to heat the body 2200, and wherein the second power connection 859b is preferably configured to conduct power conducted into the body 2200 by the first power connection 859a out of the body 2200. The first power connection 859a and / or the second power connection 859b are preferably coupled to an alternating current source. The body 2200 forms a physical structure, wherein the physical structure preferably forms a deposition surface 861 for depositing SiC to grow a SiC shell 211. The physical structure is preferably configured to resist the forces generated during the growth of the SiC shell 211 to a minimum thickness of at least 1 cm. Alternatively, the physical structure is preferably configured to prevent the SiC shell 211 from generating forces during growth to a minimum thickness of at least 1 cm. Both (resistance / prevention) preferably allow or enable the physical structure to at least prevent rupture due to forces generated in a defined volume portion of the physical structure. The defined volume portion 2202 is preferably formed between a first plane 2204 and a second plane 2206, wherein the first plane 2204 is more preferably orthogonal to the body length ML, and wherein the second plane 2206 is orthogonal to the body length ML or to the main extension direction of the connecting portion 2236. The distance 2208 between the first plane 2204 and the second plane 2206 is preferably at least 5% of the body length ML.

[0156] Figure 8a-8c An example of a carbon fiber composite element 2242 for forming a SiC growth substrate 857 is schematically shown. The carbon fiber composite element 2242 is preferably very thin or comprises very thin portions, in particular portions having a thickness of less than 1 cm or a thickness of less than 0.5 cm or a thickness of less than 0.2 cm or less than 0.1 cm. The carbon fiber composite element 2242 preferably has a certain shape, in particular a curved or sharply curved shape, which gives the carbon fiber composite element 2242 mechanical stability to allow upright positioning.

[0157] Figure 8dAn example is shown, according to which a first carbon fiber composite element 2242a, a second carbon fiber composite element 2242b and a third carbon fiber composite element 2242c are coupled to each other to form a SiC growth substrate 857. In this example, the carbon fiber composite element 2242a / b and the carbon fiber composite element 2242b / c form an overlapping region 2230 for coupling the corresponding carbon fiber composite element 2242a / b or 2242b / c. In this example, the coupling is achieved by a coupling element 2230, wherein the coupling element 2230 can be, for example, a screw or a pin or a stud. The coupling element 2230 is preferably made of graphite. However, in addition or alternatively, the carbon fiber composite element 2242a / b and / or the carbon fiber composite element 2242b / c can be coupled by force fit and / or form fit and / or adhesive fit. In this example, carbon fiber composite elements 2242a / b and carbon fiber composite elements 2242b / c have the same or similar shapes, however, some or all of the carbon fiber composite elements may have different shapes or a shape different from at least one other carbon fiber composite element.

[0158] Figure 9a - Figure c schematically shows a further example of a carbon fiber composite element 2242. The carbon fiber composite element 2242 can be manufactured to allow a form fit and / or a force fit.

[0159] Figure 9d An example of a further SiC growth substrate 857 formed from a plurality of carbon fiber composite elements 2242 is schematically shown.

[0160] List of reference numerals

[0161] 202 upper shell

[0162] 203 horizontal member

[0163] 206a first electrode

[0164] 206b second electrode

[0165] 208 Chuck

[0166] 209 Temperature measurement path

[0167] 211SiC shell

[0168] 213 mirror

[0169] 850 Manufacturing device or CVD unit or CVD reactor or SiC production reactor, especially SiC PVT source material production reactor

[0170] 851 first feeding device or first feeding medium source

[0171] 852 second feeding device or second feeding medium source

[0172] 853 third feeding device or third feeding medium source or carrier gas feeding medium source

[0173] 854 Mixing device

[0174] 855 Evaporator Device

[0175] 856 Craft Room

[0176] 857SiC growth substrate

[0177] 858 Temperature measuring device or temperature control unit

[0178] 859 Energy, especially power supply

[0179] 859a First power connection

[0180] 859b Second power supply connection

[0181] 860 Pressure holding device or pressure control unit

[0182] 861 Outer surface of SiC growth substrate or SiC growth surface

[0183] 862 base plate

[0184] 864 bell jar

[0185] 864a side wall

[0186] 864b Top wall part

[0187] 865 Metal Surface

[0188] 866 Gas Inlet Unit

[0189] 867 reflective coating

[0190] 868 Cooling element

[0191] 870 Active Cooling Element

[0192] 873 Fluid Transfer Unit

[0193] 892 Cooling Fluid Temperature Sensor

[0194] 966 Reaction Space

[0195] 1160 Feed gas mixture

[0196] 2040 Lower shell

[0197] 2120 Exhaust

[0198] 2140 Feed gas inlet

[0199] 2200 Main body

[0200] 2202 Limited volume part

[0201] 2204 First Plane

[0202] 2206 Second Plane

[0203] 2208 Distance

[0204] 2210 Carbon Fiber

[0205] 2212 Carbon fiber composite materials

[0206] 2214 ribbon shape / leaf shape

[0207] 2216 graphite element

[0208] 2218 Solid SiC Rod

[0209] 2220 Tubular Shape

[0210] 2222 Single Components

[0211] 2223 Long Non-SiC Substrate

[0212] 2224 multiple parts

[0213] 2224a First component / main component

[0214] 2224b Second component / connecting component

[0215] 2226 First Central Axis

[0216] 2228 Second Central Axis

[0217] 2230 Overlapping Area

[0218] 2232 First Leg

[0219] 2234 Second leg

[0220] 2236 Connection part

[0221] 2238 surface cooling element

[0222] 2240 side surface / circumferential surface

[0223] 2242 Carbon fiber composite components

[0224] 2242a The first carbon fiber composite component

[0225] 2242b Second carbon fiber composite element

[0226] 2242c Third carbon fiber composite component

[0227] 2244 coupling element

[0228] D Depth

[0229] ML body length

[0230] WWidth

Claims

1. A SiC growth substrate (857) for growing SiC in a CVD reactor (850), At least: A body (2200) for coupling with a first power connection (859a) and a second power connection (859b), wherein the first power connection (859a) is configured to conduct power into the body (2200) to heat the body (2200), and wherein the second power connection (859b) is configured to conduct power conducted into the body (2200) through the first power connection (859a) out of the body (2200), wherein the body (2200) has a body length (ML), wherein the body (2200) forms a deposition surface (861) for depositing SiC to grow a SiC shell (211), wherein the body (2200) includes carbon fibers (2210), Wherein, the main body (2200) is formed of a carbon fiber composite material (2212). The main body (2200) formed of the carbon fiber composite material (2212) has a tensile strength of more than 50 MPa and / or a bending strength of more than 50 MPa. wherein the body (2200) at least partially and preferably along more than 50% of the length (ML) of the body (2200) and most preferably completely has a ribbon-like shape (2214), wherein the ribbon-like shape (2214) forms a cross-section having a width (W) and a depth (D), wherein the width (W) is at least 2 times and preferably at least 3 times and more preferably at least 5 times and most preferably up to 10 times or exactly 10 times or more than 10 times the depth (D), Wherein, the width (W) is less than 1.5 cm and the depth (D) is greater than 3.0 cm.

2. The SiC growth substrate according to claim 1, It is characterized in that The defined volume portion (2202) is preferably formed between a first plane (2204) and a second plane (2206), wherein the first plane (2204) is orthogonal to the body length (ML), and wherein the second plane (2206) is orthogonal to the body length (ML), wherein a distance (2208) between the first plane (2204) and the second plane (2206) is at least 5% of the body length (ML) and / or The body (2200) is configured to resist the force generated during the growth of the SiC shell (211) to a minimum thickness of at least 3 cm to prevent the body (2200) from being broken due to the generated force.

3. The SiC growth substrate according to claim 1, It is characterized in that The body (2200) is configured to resist the force generated during the growth of the SiC shell (211) to a minimum thickness of at least 5 cm to prevent the body (2200) from being broken due to the generated force.

4. The SiC growth substrate according to claim 1, It is characterized in that The body (2200) is at least partially and preferably along more than 50% of the length of the body (2200) and most preferably completely in a tubular shape (2220), wherein the average wall thickness or depth (D) of the cross-section formed by the tubular shape (2220) is less than 5 cm and preferably less than 2 cm and particularly preferably less than 1 cm and most preferably less than 0.5 cm, in particular less than 3 mm or less than 2 mm or less than 1 mm.

5. The SiC growth substrate according to claim 1 , It is characterized in that The body (2200) is a single component (2222).

6. The SiC growth substrate according to claims 1 to 4, It is characterized in that The main body (2200) is formed by a plurality of parts (2224), wherein the plurality of parts are coupled to each other by means of form fit and / or force fit.

7. The SiC growth substrate according to claims 1 to 3, It is characterized in that The body (2200) is formed by a plurality of components (2224a, 2224b), wherein at least some of the plurality of components, and preferably most of the components, and more preferably all of the components are made of a material having a first coefficient of thermal expansion (CTE), wherein the first coefficient of thermal expansion is different from the coefficient of thermal expansion of polycrystalline SiC.

8. The SiC growth substrate according to claim 7, It is characterized in that The plurality of components (2224) comprises at least two main component type components (2224a) and at least one connecting component type component (2224b), wherein the at least two main components (2224a) are coupled via at least one connecting component (2224b), wherein the main component type components (2224a) have a tubular (2220) or rod-like (2218) or blade-like shape (2214), and wherein at least most of the main component type components (2224a) are longer than the connecting component type components (2224b).

9. The SiC growth substrate according to claim 8, It is characterized in that The length of each of at least two components (2224a) of the main component type is less than 100 cm and greater than 5 cm as well as At least two components of the main component type (2224a) are made of graphite.

10. The SiC growth substrate according to claim 8 or 9, It is characterized in that A first component (2224a) of at least two components of the primary component type has a first central axis (2230) as well as The second part (2224a) of the at least two parts of the main part type has a second central axis (2232), The first central axis (2230) and the second central axis (2232) are arranged parallel to each other.

11. The SiC growth substrate according to claims 1 to 10, It is characterized in that The main body (2200) is formed in a U shape.

12. A CVD reactor (850), in, The CVD reactor (850) includes a process chamber (856), wherein the process chamber (856) is surrounded by at least a bottom plate (862), a side wall portion (864a) and a top wall portion (864b), a gas inlet unit (866) for introducing one or more feed media into the reaction space of the process chamber (856) to generate a source medium, wherein the gas inlet unit (866) is coupled to at least one feed medium source (851), wherein the Si and C feed medium source (851) provides at least Si and C, in particular SiCl3 (CH3), and wherein the carrier gas feed medium source (853) provides a carrier gas, in particular H2, or The gas inlet unit (866) is coupled to at least two feed medium sources (851, 852). wherein the Si feed medium source (851) provides at least Si, and wherein the C feed medium source (852) provides at least C, in particular natural gas, methane, ethane, propane, butane and / or acetylene, and wherein the carrier gas medium source (853) provides a carrier gas, in particular H2, one or more SiC growth substrates (857) according to claims 1 to 22, in particular more than 3 or more than 4 or more than 6 or more than 8 or more than 16 or more than 32 or more than 64 or up to 128 or up to 256 SiC growth substrates (857) arranged in the process chamber (856) for depositing SiC, Each SiC growth substrate (857) is coupled between at least one first metal electrode (206a) and at least one second metal electrode (206b) for heating the outer surface of the SiC growth substrate (857) or the surface of the deposited SiC, in particular by resistive heating and preferably by internal resistance heating to a temperature between 1300°C and 1800°C, wherein the first metal electrode (206a) and the second metal electrode (206b) are preferably isolated from the reaction space (966).

13. The CVD reactor according to claim 12, It is characterized in that At least one first metal electrode (206a) and at least one second metal electrode (206b) are connected to an alternating current source, wherein the alternating current source is configured to set the frequency of the alternating current to above 5 Hz, or preferably above 20 Hz, or more preferably above 50 Hz, or most preferably above 500 Hz or up to 5000 Hz, in particular up to 2000 Hz or up to 1000 Hz or up to 500 kHz.

14. A method for growing SiC, in particular a method for growing SiC on a SiC growth substrate (857) according to claims 1 to 12, At least the following steps are included: The current flowing through the SiC growth substrate (857) is increased over time to maintain the temperature of the growth surface within a defined temperature range, depositing SiC on a SiC growth substrate (857) to form a SiC shell (211), The SiC shell (211) is grown to a thickness greater than 1 cm, A defined volume portion of the SiC growth substrate (857) is prevented from fracturing during a growth step by the body (2200), wherein: The main body (2200) is formed of a carbon fiber composite material (2212). The main body (2200) formed of the carbon fiber composite material (2212) has a tensile strength of more than 50 MPa and / or a bending strength of more than 50 MPa. wherein the body (2200) at least partially and preferably along more than 50% of the length (ML) of the body (2200) and most preferably completely has a ribbon-like shape (2214), wherein the ribbon-like shape (2214) forms a cross-section having a width (W) and a depth (D), wherein the width (W) is at least 2 times and preferably at least 3 times and more preferably at least 5 times and most preferably up to 10 times or exactly 10 times or more than 10 times the depth (D), Wherein, the width (W) is less than 1.5 cm and the depth (D) is greater than 3.0 cm.

15. The method according to claim 14, It is characterized in that The current is alternating current.

16. The method according to claim 15, It is characterized in that The frequency of the alternating current is higher than 5 Hz or preferably higher than 20 Hz or more preferably higher than 50 Hz or most preferably higher than 500 Hz or up to 5000 Hz, in particular up to 2000 Hz or up to 1000 Hz or up to 500 kHz.

17. A method for growing SiC, in particular a method for growing SiC on a SiC growth substrate (857) according to claims 1 to 12, At least the following steps are included: increasing an alternating current through the SiC growth substrate (857) over time to maintain the temperature of the growth face within a defined temperature range, wherein the frequency of the alternating current is higher than 5 Hz or preferably higher than 20 Hz or more preferably higher than 50 Hz or most preferably higher than 500 Hz or up to 5000 Hz, in particular up to 2000 Hz or up to 1000 Hz or up to 500 kHz, depositing SiC on a SiC growth substrate (857) to form a SiC shell (211), The SiC shell (211) is grown to a thickness greater than 1 cm, A defined volume portion of the SiC growth substrate (857) is prevented from fracturing during a growth step by the body (2200), wherein: The main body (2200) is formed of a carbon fiber composite material (2212). The main body (2200) formed of the carbon fiber composite material (2212) has a tensile strength of more than 20 MPa and / or a bending strength of more than 20 MPa. wherein the body (2200) at least partially and preferably along more than 50% of the length (ML) of the body (2200) and most preferably completely has a ribbon-like shape (2214), wherein the ribbon-like shape (2214) forms a cross-section having a width (W) and a depth (D), wherein the width (W) is at least 2 times and preferably at least 3 times and more preferably at least 5 times and most preferably up to 10 times or exactly 10 times or more than 10 times the depth (D), Wherein, the width (W) is less than 1.5 cm and the depth (D) is greater than 3.0 cm.

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