Method for producing at least one crack-free SiC component

Abstract

The invention relates to a SiC carrier wafer (2322), in particular a crack-free SiC carrier wafer (2322), where the diameter of the SiC carrier wafer (2322) is at least 7.5 cm, where the height of the SiC carrier wafer (2322) is between 200 [mu] m and 500 [mu] m, where the SiC carrier wafer (2322) comprises at least one or exactly one inner portion (2600), in particular one central inner portion (2600), and where the SiC carrier wafer (2322) comprises an outer portion (2602), where the outer portion (2602) comprises at least one or exactly one inner portion (2600), in particular one central inner portion (2600). Wherein the outer portion (2602) surrounds the inner portion (2600), where the inner portion (2600) consists of a portion of the SiC growth substrate (857), where the inner portion (2600) is formed of a crystal structure, where the crystal structure of the inner portion (2600) is formed of a 3C crystal structure, and where the outer portion (2602) is formed of a crystal structure, where the crystal structure of the outer portion (2602) is formed of a 3C crystal structure, where the crystal structure of the inner portion (2600) is formed of a portion of the SiC growth substrate (857). The carrier wafer (2322) comprises crystallites (2414) extending more than 5 [mu] m, in particular more than 10 [mu] m, preferably more than 20 [mu] m, particularly preferably more than 50 [mu] m, most preferably up to 500 [mu] m or up to 300 [mu] m in the length direction of the individual crystallites (2414), the curvature of the carrier wafer (2322) being preferably lower than 50 [mu] m, in particular lower than 20 [mu] m, and / or the warpage of the carrier wafer (2322) being preferably lower than 50 [mu] m, in particular lower than 20 [mu] m. Wherein the crystal structure of the inner part (2600) and the crystal structure of the outer part (2602), in particular the 3C crystal structure of the inner part (2600) and the 3C crystal structure of the outer part (2602), are doped with nitrogen, in particular more than 2000 ppba nitrogen, and the electrical resistivity is less than 0.03 Ohm cm, preferably less than 0.02 Ohm cm, most preferably less than 0.01 Ohm cm.

Description

Technical Field

[0001] The present invention relates to a SiC carrier wafer according to claim 1, a composite substrate according to claim 12, a method for producing at least one SiC carrier wafer according to claim 13, a method for producing at least one large SiC component according to claim 38, a method for producing a plurality of crack-free workpieces according to claim 60, a method for producing a SiC carrier wafer according to claim 62, a method for producing a composite substrate according to claim 66, an electronic device according to claim 71, and a SiC production reactor according to claim 72. Background Art

[0002] Document WO 2022 / 123078 discloses a beneficial CVD process for producing PVT source materials.

[0003] US3030189A and US3011877A disclose methods for producing small SiC components, but none of the above documents discloses a method for producing a thin and large-sized SiC carrier wafer.

[0004] The cost of producing carrier wafers made of SiC is high. In addition, the bow and warp of the wafer are also key factors, because the bow and warp will increase with the increase of the wafer surface size due to internal stress, especially for thin wafers, because the structural compensation of the internal tension of the wafer is less, the bow and warp will be larger.

[0005] Furthermore, the parameters disclosed in US Pat. No. 3,030,189 A and US Pat. No. 3,011,877 A do not describe the production of a large ingot comprising a crack-free portion from which a SiC carrier wafer can be taken.

[0006] Furthermore, US Pat. No. 3,030,189 A and US Pat. No. 3,011,877 A disclose the growth of SiC in a temperature range between 1300° C. and 1400° C., wherein such a temperature range allows only a slow growth rate and thus the formation of short crystallites.

[0007] Therefore, thin and large SiC carrier wafers are produced by epitaxy, which is slow and costly. Summary of the invention

[0008] It is therefore an object of the present invention to provide a large-sized, inexpensive and thin SiC carrier wafer with a bow or warp below 50 μm.

[0009] The SiC carrier wafer according to claim 1 achieves the aforementioned object.

[0010] The SiC carrier wafer, in particular the crack-free SiC carrier wafer, according to the invention has a diameter of at least 7.5 cm, wherein the SiC carrier wafer has a height between 200 μm and 500 μm, wherein the SiC carrier wafer comprises at least one inner portion or exactly one inner portion, in particular one central inner portion, and wherein the SiC carrier wafer comprises an outer portion, wherein the outer portion surrounds the inner portion, wherein the inner portion consists of a portion of the SiC growth substrate, wherein the inner portion is formed by a crystal structure, wherein the crystal structure of the inner portion is mainly formed by a 3C crystal structure, and wherein the outer portion is formed by a crystal structure, wherein the crystal structure of the outer portion is mainly formed by a 3C crystal structure. The structure is formed and includes crystallites extending in the length direction of a single crystallite for more than 5 μm, in particular more than 10 μm and preferably more than 20 μm and particularly preferably more than 50 μm and most preferably up to 500 μm or up to 300 μm, wherein the curvature of the SiC carrier wafer is less than 50 μm, in particular less than 20 μm, and / or wherein the warp of the SiC carrier wafer is less than 50 μm, in particular less than 20 μm, wherein the crystal structure of the inner part and the crystal structure of the outer part, in particular the 3C crystal structure of the inner part and the 3C crystal structure of the outer part are both doped with nitrogen, in particular nitrogen doped with more than 2000 ppba, and have a resistivity of less than 0.03 Ohm cm, preferably less than 0.02 Ohm cm and most preferably less than 0.01 Ohm cm.

[0011] This solution has the additional advantage that, since the length of the crystallites is greater than 5 μm, in particular greater than 10 μm, preferably greater than 20 μm, particularly preferably greater than 50 μm, most preferably up to 500 μm or up to 300 μm, the conductivity is enhanced and the doping amount can be smaller to achieve the same resistivity, in particular to achieve a resistivity of less than 0.03 Ohm cm, preferably less than 0.02 Ohm cm, most preferably less than 0.01 Ohm cm. The doping amount is preferably less than 10 19 Nitrogen atoms / cm 3 , especially less than 10 18 Nitrogen atoms / cm 3. Doping is preferably carried out during the growth of the second substrate, in particular by adding nitrogen and / or ammonium to the reaction chamber of the CVD reactor used. B. Jayant Baliga in "Wide Bandgap Semiconductor Power Devices; Materials, Physics, Design, and Applications; A volume in Woodhead Publishing Series in Electronic and Optical Materials; Book; 2019; ISBN: 978-0-08-102306-8" discloses that the specific resistivity is affected by doping, in particular nitrogen doping.

[0012] This solution is beneficial because the substrate is at least partially grown radially (in particular by a CVD process). Such a CVD process is described, for example, in patent application EP22173970.9, filed with the European Patent Office on May 18, 2022. The subject matter of EP22173970.9 is incorporated herein by reference in its entirety. Therefore, the growth starting surface extends in more than two dimensions, surrounding or covering a three-dimensional structure, respectively. Growing large SiC ingots by a CVD process allows the removal of multiple polycrystalline SiC wafers in a very cost-effective manner. Therefore, the production cost of the radially grown second substrate is much lower than that of conventional epitaxial processes. In addition, since there is no uniform microcrystalline orientation in the radially grown polycrystalline SiC wafer, the tension that causes bending and / or warping can be compensated by heterogeneous microcrystalline orientation. Therefore, fewer post-processing steps are required, so the resulting polycrystalline SiC wafer (second substrate) can be produced more cheaply.

[0013] According to a preferred embodiment of the present invention, every 1 mm of the outer part 3 There are more than 5 crystallites, in particular more than 10 crystallites, more preferably more than 100 crystallites, most preferably more than 500 crystallites, or up to 10,000 crystallites, and these crystallites extend in the length direction of a single crystallite for more than 5 μm, in particular more than 10 μm, preferably more than 20 μm, particularly preferably more than 50 μm, more preferably up to 300 μm, and most preferably up to 500 μm. The benefit of this embodiment is that the more large-sized crystallites there are, the stronger the stabilizing effect of large crystallites.

[0014] According to a preferred embodiment of the present invention, the inner portion comprises crystallites extending in the length direction of the individual crystallites for more than 5 μm, in particular for more than 10 μm, preferably for more than 20 μm, particularly preferably for more than 50 μm, more preferably up to 300 μm, and most preferably up to 500 μm. Of all crystallites having a length of more than 5 μm, more than 50% of the crystallites have an extension in the width direction (orthogonal to the length direction of the individual crystallites) of less than 0.8 times the length extension, preferably less than 0.5 times the length extension, and more preferably less than 0.3 times the length extension.

[0015] The present embodiment is advantageous in that the compensation of tension occurs in both the inner and outer parts. The growth of crystallites having a length greater than 5 μm, in particular greater than 10 μm, preferably greater than 20 μm, particularly preferably greater than 50 μm, more preferably up to 300 μm, and most preferably up to 500 μm requires fast material growth or high deposition rates, so that the deposition surface temperature of the growth surface is greater than 1400°C.

[0016] According to a preferred embodiment of the present invention, every 1 mm of the inner part 3 There are more than 5 crystallites, especially more than 10 crystallites, more preferably more than 100 crystallites, most preferably more than 500 crystallites, or up to 10,000 crystallites, and these crystallites extend in the length direction of a single crystallite by more than 5 μm, especially more than 10 μm, preferably more than 20 μm, particularly preferably more than 50 μm, more preferably up to 300 μm, and most preferably up to 500 μm.

[0017] The benefit of this embodiment is that the more large-sized crystallites there are, the stronger the stabilizing effect of the large crystallites is.

[0018] According to a preferred embodiment of the present invention, of all the crystallites in the inner part extending more than 5 μm, in particular more than 10 μm, preferably more than 20 μm, particularly preferably more than 50 μm, more preferably up to 300 μm, and most preferably up to 500 μm in the length direction of a single crystallite, more than 50%, preferably at least 60%, and most preferably at least 70% of the crystallites are inclined at an angle less than + / - 22.5° to the middle direction of extension of the crystallite in the inner part.

[0019] This embodiment is advantageous in that the inner portion is removed from a portion of the ingot which is at a distance from the centerline of the ingot. Thus, the size of the ingot is such that the multiple components are removable so that a single wafer can be taken from each component, wherein the orientation of the crystallites preferably varies from component to component. Thus, one ingot provides material for producing a large number of SiC carrier wafers.

[0020] According to a preferred embodiment of the present invention, of all the crystallites in the outer part extending more than 5 μm, in particular more than 10 μm, preferably more than 20 μm, particularly preferably more than 50 μm, more preferably up to 300 μm, and most preferably up to 500 μm in the length direction of a single crystallite, more than 25%, preferably at least 50% and / or most preferably up to 75% of the crystallites are inclined at an angle greater than + / - 22.5° to the middle direction of extension of the inner part.

[0021] This embodiment is beneficial in that a large number of crystallites of the outer portion tend to be in the extended middle direction of the inner portion, thereby causing a beneficial compensation of the tension.

[0022] According to a preferred embodiment of the present invention, the chemical composition included in the interface between the external part and the internal part is the same as the chemical composition of a part in the external part, which is located between the interface (between the external part and the internal part) and the surrounding surface of the external part, and / or is the same as the chemical composition of a part of the internal part, which is located between the interface (between the external part and the internal part) and the center of the internal part.

[0023] This embodiment is advantageous in that no oxide layer is present. Therefore, an etching step must be performed before depositing SiC on the SiC growth substrate. The surface layer of the SiC growth substrate reacts with air and thus forms an oxide layer. If this oxide layer is not desired, it needs to be removed. Since the SiC carrier wafer should have a uniform conductivity, it is not desired that the inner part has a different chemical composition. Therefore, etching, in particular H etching or H plasma etching, is preferably performed as part of the production method.

[0024] According to a preferred embodiment of the present invention, the inner portion has a cross-sectional area orthogonal to the circumferential direction, which cross-sectional area is at least 0.5 cm 2 , preferably at least 2 cm 2 , most preferably at least 5 cm 2 or up to 50cm 2 .

[0025] The benefit of this embodiment is that the surface of the SiC growth substrate with a large cross-sectional area is much larger than that of the SiC growth substrate with a small cross-sectional area. Therefore, more material can be deposited from the beginning on the SiC growth substrate with a large cross-sectional area compared to the SiC growth substrate with a small cross-sectional area. In addition, the SiC growth substrate with a large cross-sectional area is more stable mechanically, so it does not require much attention during processing.

[0026] According to a preferred embodiment of the present invention, the cross-sectional area of ​​the SiC growth substrate has a circular or rectangular shape, or the cross-sectional area of ​​the SiC growth substrate has a strip-like shape. In the case of the strip-like shape, the SiC growth substrate preferably has two large surface portions connected by a small surface portion, wherein the surface size of the large surface portion is larger than the surface size of the small surface portion, in particular, the surface size of the large surface portion is more than 5 times or more than 50 times or up to 1000 times the surface size of the small surface portion.

[0027] The benefit of this embodiment is that this "ribbon" shape can provide a larger growth surface compared to a circle.

[0028] According to a preferred embodiment of the invention, the SiC carrier wafer comprises a treated surface, wherein the treated surface is produced by mechanical singulation, in particular by cleaving or sawing, of a preferably crack-free SiC component having a thickness of at least 1 cm.

[0029] The benefit of this embodiment is that the SiC carrier wafer is taken out from a SiC solid (especially a crystal ingot or a crystal rod). The cost of taking out multiple SiC carrier wafers from a crystal ingot or a crystal rod is much lower than the cost of epitaxially growing a carrier wafer.

[0030] According to a preferred embodiment of the present invention, the treated surface is a mechanically structured surface, wherein the mechanically structured surface is ground and / or finely ground and / or polished, in particular, the surface roughness R A Reduced to below 5 nm, particularly below 3 nm, most preferably below or equal to 1 nm.

[0031] The benefit of this embodiment is that a single crystal wafer can be bonded to the surface.

[0032] The aforementioned object is also achieved by the composite substrate according to claim 12. The composite substrate according to the present invention comprises at least the SiC carrier wafer according to the present invention (in particular the SiC carrier wafer according to any one of claims 10 or 11) and a single-crystalline SiC wafer, wherein the single-crystalline SiC wafer is bonded to the processed surface of the carrier wafer.

[0033] The present solution is advantageous in that it provides a cheap and stable composite substrate.

[0034] The aforementioned object is also achieved by a method for producing at least one SiC carrier wafer, in particular a crack-free SiC carrier wafer, according to claim 13. According to the present invention, the method comprises at least the following steps: a CVD reactor is provided, at least one SiC growth substrate is provided in the CVD reactor, wherein the SiC growth substrate forms a deposition surface surrounding the SiC growth substrate in a circumferential direction of the SiC growth substrate, wherein the deposition surface preferably extends in a 3D space, and a SiC solid is grown by depositing SiC on the deposition surface in the CVD reactor, in particular to a diameter of at least 7.5 cm or a cross-sectional area orthogonal to the length direction of the SiC growth substrate of at least 44.17 cm 2 The invention relates to a SiC solid, mechanically removing at least one SiC component from the SiC solid, in particular by sawing, and mechanically removing at least one SiC carrier wafer from the SiC component.

[0035] The present solution is beneficial in that it provides a lower cost approach compared to large SiC carrier wafer sizes produced by epitaxy.

[0036] According to a preferred embodiment of the present invention, the step of growing SiC solid comprises setting the deposition rate (especially setting the vertical deposition rate) to be greater than 200 μm / h, particularly greater than 250 μm / h, preferably greater than 300 μm / h, more preferably greater than 400 μm / h, most preferably greater than 500 μm / h or up to 2000 μm / h. The benefit of this embodiment is that the output can be increased. This is preferably achieved by simultaneously performing defined heating of the physical structure and defined feeding of the feed gas and the cooling unit.

[0037] 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.

[0038] According to a preferred embodiment of the present invention, a step of analyzing the SiC solid to determine the crack-free portion of the SiC solid is performed, wherein the step of analyzing the SiC solid is performed before the step of mechanically removing at least one SiC component from the SiC solid, in particular by sawing. This embodiment is advantageous in that the crack-free volume of the SiC solid can be identified and used for SiC carrier wafer production.

[0039] According to a preferred embodiment of the present invention, at least one SiC component is taken out from the crack-free portion of the SiC solid, or wherein the crack-free portion of the SiC solid is taken out as at least one SiC component.

[0040] According to a preferred embodiment of the present invention, the step of analyzing the SiC solid to determine the crack-free portion of the SiC solid is performed by optical inspection, in particular by caliper or threshold detection. The advantages of this embodiment are that the optical inspection does not damage the SiC solid, and the optical inspection method has been perfected and can provide high-quality information.

[0041] According to a preferred embodiment of the present invention, a step of analyzing the SiC component or SiC carrier wafer to determine defects, in particular cracks, is performed. This embodiment is advantageous in that further processing of defective wafers can be avoided, thereby reducing overall costs.

[0042] According to a preferred embodiment of the present invention, the step of analyzing the SiC component or SiC carrier wafer to determine defects is performed by a bending test (in particular a 2-point bending test, a 3-point bending test or a 4-point bending test), an eddy current test and / or an optical analysis method (in particular a caliper test or a threshold test or a transmission test). The benefit of this embodiment is that the mentioned detection method has been perfected and can provide high-quality information. The test method and system are described in https: / / www.isravision.com / en / semiconductor / applications / back-end-of-line / internal-cracks / crack-detection-for-semiconductor-wafers / ; https: / / www.hindawi.com / journals / amse / 2013 / 950791 / ; https: / / cjme.springeropen.com / articles / 10.1186 / s10033-018-0229-2.

[0043] According to a preferred embodiment of the present invention, a step of conducting a current from the first power connection to the second power connection or from the second power connection to the first power connection is performed so that the current passes through the SiC growth substrate to heat the SiC growth substrate. This embodiment is advantageous in that the power supply can be controlled and therefore the temperature can be adjusted very accurately.

[0044] According to a preferred embodiment of the invention, the SiC growth substrate, in particular the growth surface of the deposited SiC, is heated to a temperature exceeding 1400° C. This embodiment is advantageous in that the deposition rate is higher compared to a temperature range below 1400° C. Due to the high deposition rate, the crystallites grow into the extension direction of the SiC growth substrate, wherein the extension direction describes the direction in which the SiC is deposited on the SiC growth substrate.

[0045] According to a preferred embodiment of the present invention, the growth surface of the deposited SiC is heated to a temperature below 1700° C., and the center of the SiC growth substrate is heated to a temperature above 1400° C. The advantages of this embodiment are that the diameter (greater than 7.5 cm) or the cross-sectional area (greater than 44.17 cm) of the SiC solid (inner part plus outer part) is 2 ) is larger, the power required to heat the growth surface to a temperature above 1400°C increases, thereby increasing the temperature at the center of the SiC growth substrate. It is found that a temperature difference exceeding 300K causes tension inside the SiC solid, wherein the tension causes cracks inside the SiC solid. Therefore, the present embodiment can avoid the occurrence of cracks.

[0046] According to a preferred embodiment of the present invention, the electric current is provided in the form of an alternating current. This embodiment is advantageous in that, due to the effect of the alternating current, the electric power is directed along the outer surface of the growing SiC, so that the center is heated to a lower degree than with a direct current. This is advantageous because the temperature of the center is preferably lower than the temperature of the outer surface. This is very beneficial in forming a uniform temperature distribution between the center and the outer surface, so that the temperature difference between the outer surface and the center is preferably less than 300K, more preferably 200K, particularly preferably less than 100K, and most preferably less than 50K. This is beneficial in growing SiC at low tension levels to avoid cracking of the SiC.

[0047] According to a preferred embodiment of the invention, 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. Preferably, the frequency of the alternating current can be modified during SiC production to better meet the requirements of SiC solids with small growth surfaces and SiC solids with large growth surfaces. This embodiment is beneficial in that higher growth rates and smaller temperature differences can be established.

[0048] According to another preferred embodiment of the present invention, the grown SiC solid is heated for a defined time after the growth is completed. The defined time is preferably greater than 1 hour, in particular greater than 2 hours, preferably greater than 3 hours, particularly preferably greater than 5 hours, most preferably greater than 10 hours or up to 24 hours. The electrical energy (in particular alternating current) used to heat the SiC solid is preferably reduced continuously and / or gradually during the defined time, in particular cut off at the end.

[0049] The deposited SiC has a minimum thickness of at least 1 cm, wherein at least one SiC component is formed between a first plane and a second plane, wherein the first plane is orthogonal to the length of the body, wherein the second plane is orthogonal to the length of the body, wherein the distance between the first plane and the second plane is at least 1%, preferably at least 2%, more preferably at least 5% of the length of the body, wherein the deposited SiC is polycrystalline SiC, wherein the deposited SiC forms volume portions with different crystal structures, wherein mainly 3C crystal structures are formed (mass and / or volume), wherein the volume and / or mass of SiC formed in the 3C crystal structure accounts for more than 50% (volume and / or mass) of the deposited SiC, and wherein the SiC carrier wafer is crack-free.

[0050] According to another preferred embodiment of the present invention, at least one SiC component has a cross-sectional dimension of at least 4 cm 2 , preferably at least 8cm 2 , more preferably at least 12 cm 2 , with a thickness of at least 0.1 cm, preferably at least 1 cm, more preferably at least 2 cm, and / or wherein the volume (V) of at least one SiC component is greater than 2 cm 3 , preferably greater than 4cm 3 , most preferably greater than 8cm 3 , wherein at least one SiC component is crack-free. This embodiment is advantageous in that SiC components or SiC carrier wafers can be produced quickly and cheaply.

[0051] According to another preferred embodiment of the present invention, the SiC growth substrate includes a body, a first power connection and 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 to conduct power into the body to heat the body, and wherein the second power connection is configured to conduct power conducted into the body through the first power connection out of the body.

[0052] According to another preferred embodiment of the present invention, before the SiC growth substrate is placed in the CVD reactor, a step of etching the surface of the SiC growth substrate is performed, wherein the etching step is performed by hydrofluoric acid etching, and / or after the SiC growth substrate is provided in the CVD reactor and before the step of growing a SiC solid by depositing SiC on the deposition surface of the SiC growth substrate in the CVD reactor, a step of etching the surface of the SiC growth substrate is performed. This embodiment is beneficial in that the oxide layer originally present on the surface of the SiC growth substrate can be removed, thereby avoiding the oxide layer from existing inside the growing SiC solid, because during the growth process, SiC will be deposited on the oxide layer, thereby affecting the electrical properties of the SiC carrier wafer taken out from the SiC solid.

[0053] According to another preferred embodiment of the present invention, the etching step after the SiC growth substrate is arranged in the CVD reactor is carried out by gas etching (particularly hydrogen etching) and / or plasma etching (particularly hydrogen plasma etching). Preferably, the etching gas (particularly H) is sent into the reaction chamber where the SiC growth substrate has been placed. The etching gas can exist in the reaction chamber for a limited time (particularly up to 5 minutes or more than 5 minutes or up to 10 minutes or more than 10 minutes or up to 20 minutes or more than 20 minutes). However, the etching gas or part thereof can be renewed once or multiple times. A continuous etching gas flow entering and leaving the reaction chamber can also be established. The benefit of this embodiment is that hydrogen (H) can be used for etching as well as for carrier gas. Therefore, the reactor already includes the features required for the etching step.

[0054] According to another preferred embodiment of the present invention, the step of growing SiC solid includes realizing crystallites with a length greater than 5 μm, in particular greater than 10 μm, preferably greater than 20 μm, particularly preferably greater than 50 μm, most preferably up to 500 μm or up to 300 μm. Among all crystallites with a length greater than 5 μm, more than 50% of the crystallites have an extension in the width direction (orthogonal to the length direction of a single crystallite) less than 0.8 times the length extension, preferably less than 0.5 times the length extension, and more preferably less than 0.3 times the length extension. The benefit of this embodiment is that when the length of the crystallites exceeds 5 μm, the tension inside the SiC carrier wafer is compensated, so the resulting curvature or warping is preferably less than 50 μm, most preferably less than 20 μm.

[0055] According to another preferred embodiment of the present invention, every 1mm 3More than 5 crystallites, in particular more than 10 crystallites, more preferably more than 100 crystallites, most preferably more than 500 crystallites, or up to 10,000 crystallites are grown, and these crystallites extend in the length direction of a single crystallites for more than 5 μm, in particular more than 10 μm, preferably more than 20 μm, particularly preferably more than 50 μm, more preferably up to 300 μm, and most preferably up to 500 μm. The advantage of this embodiment is that due to a large number of long crystallites, the tension inside the SiC carrier wafer is compensated, so the resulting curvature or warp is preferably less than 50 μm, most preferably less than 20 μm.

[0056] According to another preferred embodiment of the present invention, the SiC growth substrate comprises crystallites extending in the length direction of a single crystallite for more than 5 μm, in particular more than 10 μm, preferably more than 20 μm, particularly preferably more than 50 μm, more preferably up to 300 μm, and most preferably up to 500 μm. Among all crystallites with a length of more than 5 μm, more than 50% of the crystallites have an extension in the width direction (orthogonal to the length direction of the single crystallite) of less than 0.8 times the length extension, preferably less than 0.5 times the length extension, and more preferably less than 0.3 times the length extension. The benefit of this embodiment is that the long crystallites within the SiC carrier wafer reduce the tension that can cause bending and warping. In addition, since the crystallites are larger and the conductivity is enhanced, less doping is required compared to SiC with short crystallites.

[0057] According to another preferred embodiment of the present invention, at every 1 mm of the SiC growth substrate, 3 There are more than 5 crystallites, in particular more than 10 crystallites, more preferably more than 100 crystallites, most preferably more than 500 crystallites, or up to 10,000 crystallites, and these crystallites extend in the length direction of a single crystallite for more than 5 μm, in particular more than 10 μm, preferably more than 20 μm, particularly preferably more than 50 μm, more preferably up to 300 μm, and most preferably up to 500 μm. The benefit of this embodiment is that the more large-sized crystallites there are, the stronger the stabilizing effect of large crystallites.

[0058] According to a preferred embodiment of the present invention, of all the crystallites of the SiC growth substrate extending in the length direction of a single crystallite over 5 μm, in particular over 10 μm, preferably over 20 μm, particularly preferably over 50 μm, more preferably up to 300 μm, and most preferably up to 500 μm, over 50%, preferably at least 60%, and most preferably at least 70% of the crystallites are inclined at an angle of less than + / - 22.5° to the extension middle direction of the crystallite of the SiC growth substrate. The advantage of this embodiment is that the inner part is removed from a part of the ingot, which is at a certain distance from the center line of the ingot. Therefore, the size of the ingot is such that multiple components are detachable so that a single wafer is taken out from each component, wherein the orientation of the crystallites preferably varies from component to component. Therefore, one ingot provides material for producing a large number of SiC carrier wafers.

[0059] According to another preferred embodiment of the present invention, of all the growing crystallites extending in the length direction of a single crystallite over 5 μm, in particular over 10 μm, preferably over 20 μm, particularly preferably over 50 μm, more preferably up to 300 μm, most preferably up to 500 μm, more than 25%, preferably at least 50%, most preferably up to 75% of the crystallites are inclined at an angle greater than + / - 22.5° to the extending middle direction of the inner part. This embodiment is advantageous in that a large number of crystallites of the outer part tend to the extending middle direction of the inner part, thereby causing a beneficial compensation of tension.

[0060] According to another preferred embodiment of the present invention, SiC is deposited until the SiC solid has a minimum thickness of at least 1 cm, wherein due to the deposition of SiC, at least one SiC component is formed between a first plane and a second plane, wherein the first plane is orthogonal to the length of the body, wherein the second plane is orthogonal to the length of the body, wherein the distance between the first plane and the second plane is at least 1%, preferably at least 2%, more preferably at least 5% of the length of the body, wherein the deposited SiC is polycrystalline SiC, wherein the SiC forms volume portions with different crystal structures due to the deposition, wherein mainly 3C crystal structure (mass and / or volume) is formed due to the deposition of SiC, wherein the volume and / or mass of SiC formed with 3C crystal structure due to the deposition of SiC accounts for more than 50% (volume and / or mass) of the deposited SiC, and wherein the SiC carrier wafer is crack-free.

[0061] The cross-sectional dimension of at least one SiC component is preferably at least 4 cm 2 , preferably at least 8cm 2 , more preferably at least 12 cm 2 , with a thickness of at least 0.1 cm, preferably at least 1 cm, more preferably at least 2 cm, and / or wherein the volume (V) of at least one SiC component is greater than 2 cm 3, preferably greater than 4cm 3 , most preferably greater than 8cm 3 , wherein at least one SiC component is crack-free.

[0062] This embodiment is advantageous in that SiC components or SiC carrier wafers can be produced quickly and cheaply.

[0063] The above object is also achieved by a method for producing at least one large SiC component, in particular an ingot or a rod, according to claim 38. According to the invention, the method for producing at least one large SiC component preferably comprises at least the following steps:

[0064] A CVD reactor is provided, wherein the CVD reactor is provided with at least one SiC growth substrate in the CVD reactor, wherein the SiC growth substrate forms a deposition surface surrounding the SiC growth substrate in a circumferential direction of the SiC growth substrate, and a polycrystalline SiC solid is grown by depositing SiC on the deposition surface in the CVD reactor, wherein the deposition is performed until the SiC solid grows to a diameter of at least 1 cm, or preferably at least 5 cm, or particularly preferably at least 10 cm, or most preferably at least 20 cm or up to 100 cm, wherein the deposition is performed until the SiC solid grows to a cross-sectional size of at least 40 cm 2 , especially at least 50cm 2 Or at least 200cm 2 Or at least 500cm 2 and / or up to 1000cm 2 or preferably up to 2000cm 2 And most preferably up to 8000cm 2 , orthogonal to the current conduction path inside the SiC growth substrate, analyze the SiC solid to determine that the internal cross-sectional size of the SiC solid is at least 4 cm 2 The solution is advantageous in that at least one crack-free SiC component can be produced using a CVD process, wherein the SiC component can be used, for example, to remove a plurality of carrier wafers therefrom, in particular to remove two or more or five or more or up to ten or ten or more or up to twenty or twenty or more or up to fifty or fifty or more or up to one hundred or one hundred or more carrier wafers.

[0065] According to another preferred embodiment of the present invention, the step of analyzing the SiC solid to determine the crack-free portion of the SiC solid is performed by optical inspection, in particular by caliper or threshold detection. This embodiment is advantageous in that the optical analysis can be performed quickly and cheaply without the risk of damaging the SiC solid.

[0066] According to another preferred embodiment of the present invention, the SiC solid is analyzed by determining the position and / or orientation of defects (especially cracks) inside the SiC component to determine the cross-sectional size of the SiC solid inside at least 4 cm 2 The step of determining the position of at least one crack-free SiC component. This embodiment is advantageous in that an optimum value of crack-free SiC can be determined and removed from the remaining material.

[0067] According to another preferred embodiment of the present invention, the step of analyzing the SiC component to determine the location and / or orientation of the defect is performed by a bending test (in particular a 2-point bending test, a 3-point bending test or a 4-point bending test), an eddy current test and / or an optical analysis method (in particular a caliper test or a threshold test). The benefit of this embodiment is that the mentioned detection method has been perfected and can provide high-quality information. The test method and system are described in https: / / www.isravision.com / en / semiconductor / applications / back-end-of-line / internal-cracks / crack-detection-for-semiconductor-wafers / ; https: / / www.hindawi.com / journals / amse / 2013 / 950791 / ; https: / / cjme.springeropen.com / articles / 10.1186 / s10033-018-0229-2.

[0068] According to another preferred embodiment of the present invention, a step is performed in which a current is conducted from the first power connection to the second power connection or from the second power connection to the first power connection so that the current passes through the SiC growth substrate to heat the SiC growth substrate. This embodiment is advantageous in that the power supply can be controlled and therefore the temperature can be adjusted very accurately.

[0069] According to another preferred embodiment of the invention, the SiC growth substrate, in particular the growth surface of the deposited SiC, is heated to a temperature of more than 1400° C. This embodiment is advantageous due to the higher deposition rates compared to the temperature range below 1400° C. Due to the high deposition rate, the crystallites grow into the extension direction of the SiC growth substrate, wherein the extension direction describes the direction in which the SiC is deposited on the SiC growth substrate.

[0070] According to another preferred embodiment of the present invention, the growth surface of the deposited SiC is heated to a temperature below 1700° C., and the center of the SiC growth substrate is heated to a temperature above 1400° C. This embodiment is beneficial in that the diameter (greater than 7.5 cm) or the cross-sectional area (greater than 44.17 cm) of the SiC solid (inner part plus outer part) is greater than 1700° C. 2 ) is larger, the power required to heat the growth surface to a temperature above 1400°C increases, thereby increasing the temperature at the center of the SiC growth substrate. It is found that a temperature difference exceeding 300K causes tension inside the SiC solid, wherein the tension causes cracks inside the SiC solid. Therefore, the present embodiment can avoid the occurrence of cracks.

[0071] According to another preferred embodiment of the present invention, the electric current is provided in the form of an alternating current. This is beneficial because due to the effect of the alternating current, the power is directed along the outer surface of the growing SiC, so that the center is heated to a lower degree compared to a direct current. This is beneficial because the temperature in 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 below 300K, more preferably 200K, particularly preferably below 100K, and most preferably below 50K. This is beneficial to grow SiC at low tension levels to avoid cracking of the SiC.

[0072] According to another preferred embodiment of the invention, 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. Preferably, the frequency of the alternating current can be modified during SiC production to better meet the requirements of SiC solids with small growth surfaces and SiC solids with large growth surfaces. This embodiment is beneficial in that higher growth rates and smaller temperature differences can be established.

[0073] According to another preferred embodiment of the invention, the step of growing the SiC component comprises setting a deposition rate, in particular setting a vertical deposition rate, greater than 200 μm / h, in particular greater than 250 μm / h, preferably greater than 300 μm / h, more preferably greater than 400 μm / h, most preferably greater than 500 μm / h or up to 2000 μm / h. This embodiment is advantageous because the throughput can be increased. This is preferably achieved by simultaneously defining heating of the physical structure and defining feeding of the feed gas and the cooling unit.

[0074] According to another preferred embodiment of the present invention, the SiC growth substrate includes a body, a first power connection and 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 to conduct power into the body to heat the body, and wherein the second power connection is configured to conduct power conducted into the body through the first power connection out of the body.

[0075] According to another preferred embodiment of the present invention, before providing the SiC growth substrate into the CVD reactor, the step of etching the surface of the SiC growth substrate is performed by hydrofluoric acid etching, and / or after providing the SiC growth substrate into the CVD reactor and before the step of growing a SiC solid by depositing SiC on the deposition surface of the SiC growth substrate in the CVD reactor, the step of etching the surface of the SiC growth substrate is performed.

[0076] The benefit of this embodiment is that it can remove the oxide layer originally present on the surface of the SiC growth substrate, thereby preventing the oxide layer from existing inside the growing SiC solid, because during the growth process, SiC will be deposited on the oxide layer, which will affect the electrical properties of the SiC carrier wafer taken out from the SiC solid.

[0077] According to another preferred embodiment of the present invention, the step of etching is carried out by gas etching (particularly hydrogen etching) and / or plasma etching (particularly hydrogen plasma etching). Preferably, etching gas (particularly H) is sent into the reaction chamber where the SiC growth substrate has been placed. The etching gas can exist in the reaction chamber for a limited time (particularly up to 5 minutes or more than 5 minutes or up to 10 minutes or more than 10 minutes or up to 20 minutes or more than 20 minutes). However, the etching gas or its part can be updated once or multiple times. A continuous etching gas flow entering and leaving the reaction chamber can also be established. The benefit of this embodiment is that hydrogen (H) can be used for etching as well as for carrier gas. Therefore, the reactor has included the features required for performing the etching step.

[0078] The step of growing SiC solid includes achieving crystallites (2414) with a length greater than 5 μm, in particular greater than 10 μm, preferably greater than 20 μm, particularly preferably greater than 50 μm, most preferably up to 500 μm or up to 300 μm. Among all crystallites with a length greater than 5 μm, more than 50% of the crystallites preferably have an extension in the width direction (orthogonal to the length direction of the individual crystallites) less than 0.8 times the length extension, preferably less than 0.5 times the length extension, and more preferably less than 0.3 times the length extension. The benefit of this embodiment is that since the length of the crystallites exceeds 5 μm, the tension inside the SiC carrier wafer is compensated, so the resulting curvature or warping is preferably less than 50 μm, most preferably less than 20 μm.

[0079] According to another preferred embodiment of the present invention, the growing step comprises: 3 More than 5 crystallites, in particular more than 10 crystallites, more preferably more than 100 crystallites, most preferably more than 500 crystallites, or up to 10,000 crystallites are grown, and these crystallites extend in the length direction of a single crystallites for more than 5 μm, in particular more than 10 μm, preferably more than 20 μm, particularly preferably more than 50 μm, more preferably up to 300 μm, and most preferably up to 500 μm. The advantage of this embodiment is that due to a large number of long crystallites, the tension inside the SiC carrier wafer is compensated, so the resulting curvature or warp is preferably less than 50 μm, most preferably less than 20 μm.

[0080] According to another preferred embodiment of the present invention, the SiC growth substrate comprises crystallites extending in the length direction of a single crystallite for more than 5 μm, in particular more than 10 μm, preferably more than 20 μm, particularly preferably more than 50 μm, more preferably up to 300 μm, and most preferably up to 500 μm. Among all crystallites with a length of more than 5 μm, more than 50% of the crystallites have an extension in the width direction (orthogonal to the length direction of the single crystallite) of less than 0.8 times the length extension, preferably less than 0.5 times the length extension, and more preferably less than 0.3 times the length extension. The benefit of this embodiment is that the long crystallites within the SiC carrier wafer reduce the tension that can cause bending and warping. In addition, since the crystallites are larger and the conductivity is enhanced, less doping is required compared to SiC with short crystallites.

[0081] According to another preferred embodiment of the present invention, at every 1 mm of the SiC growth substrate, 3 There are more than 5 crystallites, in particular more than 10 crystallites, more preferably more than 100 crystallites, most preferably more than 500 crystallites, or up to 10,000 crystallites, and these crystallites extend in the length direction of a single crystallite for more than 5 μm, in particular more than 10 μm, preferably more than 20 μm, particularly preferably more than 50 μm, more preferably up to 300 μm, and most preferably up to 500 μm. The benefit of this embodiment is that the more large-sized crystallites there are, the stronger the stabilizing effect of large crystallites.

[0082] According to a preferred embodiment of the present invention, of all the crystallites of the SiC growth substrate extending in the length direction of a single crystallite over 5 μm, in particular over 10 μm, preferably over 20 μm, particularly preferably over 50 μm, more preferably up to 300 μm, and most preferably up to 500 μm, over 50%, preferably at least 60%, and most preferably at least 70% of the crystallites are inclined at an angle less than + / - 22.5° to the middle direction of the extension of the crystallites of the SiC growth substrate. The benefit of this embodiment is that the inner part is removed from a part of the ingot which is at a certain distance from the centerline of the ingot. Thus, the size of the ingot is such that a plurality of components are detachable so as to take out a single wafer from each component, wherein the orientation of the crystallites preferably varies from component to component. Thus, one ingot provides material for producing a large number of SiC carrier wafers.

[0083] According to another preferred embodiment of the present invention, of all crystallites extending in the length direction of a single crystallite over 5 μm, in particular over 10 μm, preferably over 20 μm, particularly preferably over 50 μm, more preferably up to 300 μm, and most preferably up to 500 μm, over 25%, preferably at least 50%, and most preferably up to 75% of the crystallites grow at an angle greater than + / - 22.5° to the middle direction of extension of the inner part. The benefit of this embodiment is that a large number of crystallites in the outer part tend to the middle direction of extension of the inner part, thereby causing a beneficial compensation of tension.

[0084] According to another preferred embodiment of the present invention, the SiC solid grows to a diameter of at least 7.5 cm. This embodiment is advantageous in that a large SiC carrier wafer can be taken out from an ingot or a crystal rod with a diameter of 7.5 cm or more.

[0085] According to another preferred embodiment of the present invention, during the growth step, the SiC (particularly the deposited SiC) is doped with nitrogen, in particular with nitrogen exceeding 2000 ppba and / or with nitrogen below 10 18 Nitrogen atoms / cm 3 The advantage of this embodiment is that fewer doping atoms can be used to establish the necessary conductivity compared to known processes. This is due to the large crystallites grown by the present invention.

[0086] According to another preferred embodiment of the present invention, the SiC solid is mainly grown in a 3C crystal structure. The advantage of this embodiment is that the characteristics of the SiC carrier wafer mainly having a 3C crystal structure are better than those of other crystal structures.

[0087] The above object is also achieved by a method for producing a plurality of crack-free workpieces according to claim 60. According to the present invention, the method for producing a plurality of crack-free workpieces preferably comprises at least one method for producing at least one large SiC component disclosed herein, in particular the method according to claims 38 to 59, and a step of dividing the at least one crack-free SiC component into a plurality of predetermined components. The dividing step preferably comprises cutting a defined volume portion using at least one wire saw or weakening a defined volume structure with laser radiation, thereby generating a defined laser division plane, and introducing an external force so that the crack propagates along the defined laser division plane, or implanting ions into a defined volume structure, thereby generating a defined ion division plane, and increasing the pressure in the defined volume by increasing the volume of implanted ions, in particular by heating the defined volume, so that the crack propagates along the defined ion division plane. The advantage of this embodiment is that the SiC carrier wafer taken out of the SiC component is much cheaper than the epitaxially grown SiC carrier wafer.

[0088] According to another preferred embodiment of the present invention, the predetermined components are wafers, in particular SiC carrier wafers, wherein the height of each wafer is between 200 μm and 1000 μm, preferably between 200 μm and 500 μm, most preferably between 300 μm and 450 μm, wherein "height" is preferably defined as the distance between two planes parallel to each other.

[0089] The above object is also achieved by a method for producing a SiC carrier wafer according to claim 62. According to the invention, the method for producing a SiC carrier wafer preferably comprises at least one of the methods disclosed herein for producing a plurality of crack-free workpieces, in particular the method according to claim 60 or 61, and a step of processing at least one cut surface or split surface of the wafer (in particular grinding and / or fine grinding and / or polishing) to produce a processed surface with at least one defined surface property. The cut surface is produced by cutting (in particular sawing) or the split surface is produced by splitting a SiC solid (in particular an ingot or a rod) into exactly or at least two parts.

[0090] According to another preferred embodiment of the invention, the height of the carrier wafer is reduced by machining at least one cutting or separating surface to a height between 200 μm and 500 μm, most preferably between 300 μm and 450 μm.

[0091] According to another preferred embodiment of the invention, the method comprises the step of analyzing the SiC carrier wafer to determine defects, in particular to determine cracks. This embodiment is advantageous in that further processing of damaged wafers or wafers with defects can be avoided.

[0092] According to another preferred embodiment of the invention, the step of analyzing the SiC component or the SiC carrier wafer to determine defects is performed by a bend test (particularly a 2-point bend test, a 3-point bend test or a 4-point bend test), an eddy current test and / or an optical analysis method (particularly a caliper test or a threshold test). This embodiment is advantageous in that well-established methods can be applied quickly and inexpensively.

[0093] The above object is also achieved by a method for producing a composite substrate according to claim 66. The method for producing a composite substrate according to the present invention preferably comprises at least one method for producing a carrier wafer disclosed herein, in particular the method according to claims 62, 63, 64 and / or 65, and the following step: bonding a single crystal SiC wafer to the treated surface. This embodiment is advantageous in that the composite substrate can be produced in a cheap and fast manner.

[0094] According to another preferred embodiment of the present invention, a single crystal SiC wafer is formed by a crystal structure, wherein the crystal structure defines a c-axis, wherein the crystal structure grows perpendicular to the c-axis, wherein the single crystal SiC crystal has a preferably flat top surface, a preferably flat bottom surface, and a connecting surface connecting the top surface and the bottom surface, wherein the c-axis is at an angle between 0° and 8°, preferably between 2° and 6° relative to the normal of the top surface, wherein the single crystal SiC wafer is preferably composed of 4H-type SiC. This embodiment is beneficial in that the produced composite wafer can be further processed to produce a device.

[0095] According to another preferred embodiment of the present invention, the method comprises the step of growing a single crystal SiC layer on a single crystal SiC wafer by epitaxy, wherein the thickness of the single crystal SiC layer is between 1 μm and 50 μm, in particular between 2 μm and 40 μm, or between 3 μm and 30 μm, or between 4 μm and 20 μm, or between 5 μm and 10 μm. This embodiment is beneficial in that the formed composite wafer can be used to produce at least one, preferably multiple products.

[0096] The above object is also achieved by an electronic device according to claim 71. The electronic device according to the present invention preferably comprises at least one composite substrate, in particular a composite substrate disclosed herein, such as a composite substrate according to claim 12 or 70, wherein at least one electronic component is grown or produced on or in a single-crystal SiC crystal layer, and wherein the thickness of the SiC carrier wafer is greater than 50 μm, in particular greater than 60 μm or greater than 80 μm or greater than 100 μm or greater than 150 μm or up to 350 μm. The electronic device may be a MOSFET or a Schottky diode. The advantage of this embodiment is that the electronic device can be produced at a lower cost and with higher quality.

[0097] The above objects are also achieved by a SiC production reactor according to claim 72, in particular for carrying out the method disclosed herein for producing at least one large SiC component, in particular the method according to any one of claims 38 to 59. The SiC production reactor preferably comprises: at least one process chamber; a gas inlet unit for supplying one or more feed media into a reaction space of the process chamber, wherein the gas inlet unit is coupled to at least one feed medium source, or wherein the gas inlet unit is coupled to at least two feed medium sources; one or more SiC growth substrates (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), which are arranged in the process chamber for depositing SiC, wherein each SiC growth substrate is coupled to 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 connected to the first power connection. The metal electrodes 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 SiC growth surface of the deposited SiC (particularly by resistive heating and preferably by internal resistive heating) to a temperature between 1400°C and 1700°C; an AC current source, wherein at least one first metal electrode and at least one second metal electrode are connected to the AC current source, wherein the AC current source is configured to set the frequency of the AC current to above 5 Hz or preferably to above 20 Hz or more preferably to above 50 Hz or most preferably to above 500 Hz or up to 5000 Hz, particularly up to 2000 Hz or up to 1000 Hz or up to 500 kHz. The process chamber is preferably enclosed by at least a bottom plate, a side wall portion and a top wall portion, wherein the bottom plate preferably comprises at least one cooling element, in particular a base cooling element, for preventing the bottom plate from heating up above a defined temperature, and / or wherein the side wall portion preferably comprises at least one cooling element, in particular a bell jar cooling element, for preventing the side wall portion from heating up above a defined temperature, and / or wherein the top wall portion preferably comprises at least one cooling element, in particular a bell jar cooling element, for preventing the top wall portion from heating up above a defined temperature. Preferably, at least one cooling element is a passive cooling element, wherein at least one 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, wherein the cooling element is preferably a coating, wherein the coating is preferably formed on top of the preferably polished steel surface, and wherein the coating is preferably configured to reflect heat, wherein the coating is preferably a metal coating or comprises a metal, in particular silver or gold or chromium, or an alloy coating, in particular a CuNi alloy. The emissivity of the polished steel surface and / or the coating is preferably below 0.3, in particular below 0.1 or below 0.03.

[0098] The solution is advantageous in that one or more SiC solids can be produced, each with a low tension level due to the small temperature difference between the core temperature of the SiC growth substrate and the temperature of the growth surface. This low tension level results in the SiC solid having only a small number of cracks, in particular 5 or 10 or 20 cracks at most, and can thus be used to produce SiC carrier wafers with low warpage and / or bow, in particular below 50 μm, preferably below 20 μm.

[0099] According to another preferred embodiment of the present invention, an exhaust gas outlet unit and an exhaust gas recovery unit for outputting exhaust gas are provided, wherein the exhaust gas recovery unit is connected to the exhaust gas outlet unit, wherein the exhaust gas recovery unit comprises at least one separator unit for separating the exhaust gas into a first fluid and a second fluid, wherein the first fluid is a liquid, wherein the second fluid is a gas, wherein a first storage and / or conduction element for storing or conducting the first fluid is part of the separator unit or coupled to the separator unit, wherein a second storage and / or conduction element for storing or conducting the second fluid is part of the separator unit or coupled to the separator unit. The benefit of this embodiment is that the cost of source materials can be significantly reduced. The separator unit is preferably operated at a pressure above 5 bar and a temperature below -30°C. Therefore, the exhaust gas is preferably fed into a separation unit, which can be a cold distillation tower, wherein Si-containing compounds are condensed from the gas into liquid form and flow down the tower and are discharged from the bottom, while the remaining H, HCl and methane gases flow up the tower and are discharged from the top. The liquid is the first fluid, preferably mainly comprising HCl and chlorosilane, and a small amount of H2 and C gas. The gas is the second fluid, preferably comprising mainly H2 and C gases, and small amounts of HCl and chlorosilanes.

[0100] According to another preferred embodiment of the present invention, the exhaust gas recovery unit comprises a further separator unit for separating the first fluid into at least two parts, wherein the two parts are a mixture of chlorosilanes and a mixture of HCl, H2 and at least one C-containing molecule, and preferably into at least three parts, wherein the three parts are a mixture of chlorosilanes, HCl and a mixture of H2 and at least one C-containing molecule, wherein the first storage and / or conducting element connects the separator unit to the further separator unit. This embodiment is advantageous in that HCl and H2 and at least one C-containing molecule can be fed directly into the process chamber of the SiC production reactor for the production of SiC material, in particular for the production of material for the manufacture of SiC carrier wafers or PVT source materials. The further separator unit is preferably configured to operate at a pressure above 5 bar and a temperature below -30°C and / or at a temperature above 100°C.

[0101] According to another preferred embodiment of the present invention, a further separator unit is coupled to the mixture or the chlorosilane storage and / or conducting element, the HCl storage and / or conducting element and the H2 and C storage and / or conducting element.

[0102] In the context of the present invention, "C" may be understood as "at least one C-containing molecule", and thus H2 and C storage and / or conduction elements may also be understood as storage and / or conduction elements of H2 and at least one C-containing molecule.

[0103] According to another preferred embodiment of the present invention, the storage and / or conducting element of the chlorosilane mixture forms part of the mass flux path of the chlorosilane mixture for conducting the chlorosilane mixture to the process chamber. This embodiment is advantageous in that the chlorosilanes can be used as a mixture. Therefore, no further processing of the chlorosilane mixture is required with respect to the separation of the individual chlorosilanes.

[0104] Therefore, according to the present invention, it is also possible to manufacture SiC materials on a large scale, in particular to manufacture materials for the production of SiC carrier wafers, or to manufacture SiC source materials having at least 6N or preferably 7N or more preferably 8N on a large scale, wherein the feed gas provided is recovered from the exhaust gas of the first SiC source production reactor. This is achieved by measuring the atomic ratio of H to C in the mixture and providing the appropriate proportion of supplementary H hydrogen and C-containing gas to the CVD reactor together with the mixture, so that the total H to C molar ratio of hydrogen and carbon in the C-containing gas is within the desired range. Under the given conditions, any carbon is present in the form of methane in the CVD reaction and the subsequent cold distillation. In the CVD reaction, any byproducts produced by methane will have a higher boiling point and will be separated from the gas phase in the cold distillation. Methane can be quantified by online or real-time measurement (PAT, process analytical technology), such as flame ionization detectors, any type of infrared spectroscopy (such as FTIR or NIR) or cavity ring-down spectroscopy (with the most sensitive detection limit), or any other online or on-line analytical method that can provide results with the required accuracy within seconds. The hydrogen content can be calculated from the measured total mass flow of the gas mixture and the quantified methane concentration. The losses are preferably compensated to maintain the molar ratio of the original feed gas mixture. The benefit of this embodiment is that due to the recycling of the exhaust gas, the purity of the recycled Si, C and H2 is further improved, so that the purity of the produced SiC is even better.

[0105] According to another preferred embodiment of the present invention, a Si mass flux measuring unit for measuring the Si content in the chlorosilane mixture is provided as part of a mass flux path before the process chamber (in particular before the mixing device), and preferably as another Si feed medium source for providing another Si feed medium. According to another preferred embodiment of the present invention, a storage and / or conducting element of the chlorosilane mixture forms part of the chlorosilane mixture mass flux path for conducting the chlorosilane mixture to another process chamber of another SiC production reactor. The advantage of this embodiment is that it is possible to control very accurately whether the feed medium from the feed source or the feed medium from the recovery unit is used. Additionally or alternatively, if the feed medium of the recovery unit is insufficient, the feed medium from the feed source can be added to the feed medium from the recovery unit.

[0106] According to another preferred embodiment of the present invention, the H2 and C storage and / or conduction element forms part of an H2 and C mass flux path for conducting H2 and at least one C-containing molecule to a process chamber. HCl may also be present. According to another preferred embodiment of the present invention, a C mass flux measurement unit for measuring the C content in a mixture of H2 and at least one C-containing molecule is provided as part of the H2 and C mass flux path before the process chamber, in particular before the mixing device, and preferably as a further C feed medium source for providing a further C feed medium. According to another preferred embodiment of the present invention, the H2 and C storage and / or conduction element forms part of an H2 and C mass flux path for conducting H2 and at least one C-containing molecule to another process chamber of another SiC production reactor. According to another preferred embodiment of the present invention, a second storage and / or conduction element forms part of an H2 and C mass flux path for conducting a second fluid comprising H2 and at least one C-containing molecule to a process chamber, wherein the second storage and / or conduction element is preferably fluidically coupled to the H2 and C storage and / or conduction element. According to another preferred embodiment of the present invention, the second storage and / or conducting element forms part of another H2 and C mass flux path for conducting a second fluid comprising H2 and at least one C-containing molecule to the process chamber. According to another preferred embodiment of the present invention, another C mass flux measuring unit for measuring the C content in the second fluid is provided as part of another H2 and C mass flux path before the process chamber, in particular before the mixing device. This embodiment is advantageous in that, in addition to using chlorosilane, H2 and at least one C-containing molecule can be recycled, thereby improving the overall efficiency.

[0107] According to a further preferred embodiment of the invention, the second storage and / or conducting element is coupled to a flare unit for burning the second fluid.

[0108] According to another preferred embodiment of the present invention, a first compressor is provided for compressing the exhaust gas to a pressure higher than 5 bar, as part of the separator unit, or provided in the gas flow path between the gas outlet unit and the separator unit. According to another preferred embodiment of the present invention, another compressor is provided for compressing the first fluid to a pressure higher than 5 bar, as part of another separator unit, or provided in the gas flow path between the separator unit and another separator unit.

[0109] The further separator unit preferably comprises a cryogenic distillation unit, wherein according to another preferred embodiment of the present invention, the cryogenic distillation unit is preferably configured to operate at a temperature between -180°C and -40°C.

[0110] This embodiment is beneficial because TCS has a boiling point of 31.8°C and STC has a boiling point of 57.7°C. With such low but very different boiling points, TCS and STC can be effectively and economically separated from each other and from any heavy contaminants (such as trace metals) by conventional distillation methods and equipment. On the other hand, purifying methane from N requires more complex cryogenic distillation. Methane boils at -161.6°C and N boils at -195.8°C. Therefore, the distillation column can be operated at a temperature somewhere in between the two, so that the methane is liquid and flows to the bottom of the column, while the nitrogen is gaseous and flows to the top of the column.

[0111] According to another preferred embodiment of the present invention, a control unit is provided for controlling the fluid flow of one or more feed media as part of a SiC production reactor, wherein the plurality of feed media comprises a first medium, a second medium, a third medium and an additional Si feed medium and / or an additional C feed medium entering the process chamber via a gas inlet unit. The additional Si feed medium preferably consists of a mixture of chlorosilanes of at least 95 mass %, or at least 98 mass %, or at least 99 mass %, or at least 99.9 mass %, or at least 99.99 mass %, or at least 99.999 mass %. The additional C feed medium preferably comprises at least one C-containing molecule, H2, HCl and a mixture of chlorosilanes, wherein the additional C feed medium comprises at least 3 mass%, or preferably at least 5 mass%, or more preferably at least 10 mass% of at least one C-containing molecule; wherein the additional C feed medium comprises HCl up to 10 mass%, or preferably between 0.001 mass% and 10 mass%, more preferably between 1 mass% and 5 mass%; wherein the additional C feed medium comprises H2 in excess of 5 mass%, or preferably in excess of 10 mass%, or more preferably in excess of 25 mass%; and wherein the additional C feed medium comprises a mixture of chlorosilanes in excess of 0.01 mass%, or preferably in excess of 1 mass%, more preferably between 0.001 mass% and 10 mass%.

[0112] According to another preferred embodiment of the present invention, a heating unit is arranged along the fluid flow direction between the other separator unit and the gas inlet unit for heating the chlorosilane mixture to convert the chlorosilane mixture from a liquid state to a gaseous state.

[0113] According to another preferred embodiment of the invention, the bottom plate comprises at least one additional cooling element, in particular a base cooling element, for preventing the bottom plate from heating up above a defined temperature, in particular for preventing the bottom plate from heating up above 1100° C., preferably for preventing it from heating up above 1000° C., most preferably for preventing it from heating up above 900° C. Additionally or alternatively, the side wall portion comprises at least one additional cooling element, in particular a bell jar cooling element, for preventing the side wall portion from heating up above a defined temperature, in particular for preventing the bottom plate from heating up above 1100° C., preferably for preventing it from heating up above 1000° C., most preferably for preventing it from heating up above 900° C.

[0114] Additionally or alternatively, the top wall portion comprises at least one additional cooling element, in particular a bell cooling element, for preventing the top wall portion from heating up to above a defined temperature, in particular for preventing the bottom plate from heating up to above 1100° C., preferably to above 1000° C., most preferably to above 900° C. The additional cooling element is preferably an active cooling element. 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 a 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 1000° C. This embodiment is advantageous in that metal parts can be used, in particular the bell can be made of metal.

[0115] According to another preferred embodiment of the present invention, a bottom plate and / or side wall portion and / or top wall portion sensor unit is provided to detect the temperature of the bottom plate and / or side wall portion and / or top wall portion and output a temperature signal or temperature data, and / or a cooling fluid temperature sensor is provided to detect the temperature of the cooling fluid, and a fluid delivery unit is provided to deliver the cooling fluid through the fluid guiding unit, wherein the fluid delivery unit is preferably configured to operate according to the temperature signal or temperature data provided by the bottom plate and / or side wall portion and / or top wall portion sensor unit and / or the cooling fluid temperature sensor. The benefit of this embodiment is that the bottom plate, the side wall portion and the top wall portion can be made of metal (especially steel). The metal bottom plate, the side wall portion and the top wall portion allow the production of larger reactors, thus helping to increase production or reduce costs.

[0116] According to another preferred embodiment of the present invention, the cooling fluid is water. According to another preferred embodiment of the present 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.

[0117] 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.

[0118] 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 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 part of the bell jar and preferably the entire bell jar, respectively, to below a defined temperature to remove a defined amount of heat per minute 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.

[0119] According to another preferred embodiment of the present invention, the carrier gas medium source provides a third feed medium (particularly H2). This embodiment is advantageous in that the carrier gas can also be used to etch the surface of the SiC growth substrate before SiC deposition.

[0120] According to another preferred embodiment of the present invention, the Si and C feed medium source provides at least Si and C, in particular, provides SiCl3 (CH3). The advantage of this embodiment is that in the case of one source gas, the ratio of Si to C is fixed.

[0121] According to another preferred embodiment of the present invention, the Si feed medium source provides at least Si, in particular the Si feed medium source provides a first feed medium, wherein the first feed medium is a Si feed medium, in particular a SiH 4-y X y (X = [Cl, F, Br, J] and y = [0..4] Si gas. Additionally, the C feed medium source provides at least C, in particular the C feed medium source 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). The advantage of this embodiment is that the source gases can be purchased separately and therefore the cost can be reduced. In addition, the mixture can be modified during the production run.

[0122] According to another preferred embodiment of the present invention, the carrier gas medium source provides a third feed medium, wherein the third feed medium is a carrier gas (particularly H 2 ).

[0123] SiC components can be used for different applications, in particular as brake wheels or PVT source material or carrier wafers. However, carrier wafers are produced according to the prior art by depositing thin layers on a substrate in a CVD process. The process is very slow and therefore costly.

[0124] Therefore, an object of the present invention is to provide a method for producing SiC for use as a SiC component at a lower cost.

[0125] The aforementioned objects can also be achieved by a method for producing at least one crack-free SiC component. The method preferably comprises at least the following steps: providing a CVD reactor, wherein the CVD reactor comprises at least one SiC growth substrate, wherein the at least one SiC growth substrate comprises a body, a first power connection and 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 to conduct power into the body to heat the body, wherein the second power connection is configured to conduct power conducted into the body through the first power connection out of the body, wherein the body forms a physical structure, wherein the physical structure forms a deposition surface for depositing SiC. The method preferably also comprises the step of growing a SiC solid by depositing SiC on the physical structure in the CVD reactor, wherein the at least one crack-free SiC component is a portion of the SiC solid, wherein the deposited SiC has a minimum thickness of at least 1 cm, wherein the at least one SiC component is formed between a first plane and a second plane, wherein the first plane is orthogonal to the body length, and wherein the second plane is orthogonal to the body length, wherein the distance between the first plane and the second plane is at least 1%, preferably at least 2%, more preferably at least 5% of the body length. Preferably, the method further comprises the step of removing at least one crack-free SiC component from the SiC solid, wherein the cross-sectional size of the at least one crack-free SiC component is at least 4 cm 2 , preferably at least 8 cm 2 , more preferably at least 12 cm 2 , and a thickness of at least 0.1 cm, preferably at least 1 cm, more preferably at least 2 cm.

[0126] This embodiment is advantageous in that crack-free SiC can be produced, thereby producing a SiC solid that can be used in different applications, in particular applications with high mechanical, thermal and / or electrical loads.

[0127] The mentioned CVD reactor (in particular each mentioned CVD reactor of the present invention) may be a modification of a CVD reactor according to PCT / EP2021 / 085479. The subject matter of PCT / EP2021 / 085479 is fully incorporated into the present subject matter by reference.

[0128] Removal can be performed by different techniques (for example according to WO2021191511, WO2016162428 or US2014038392).

[0129] According to a preferred embodiment of the present invention, the volume of at least one crack-free SiC component is greater than 2 cm 3 , preferably greater than 4cm 3 , most preferably greater than 8cm 3The present embodiment is advantageous in that the large crack-free volume allows the production of large SiC solids, in particular large carrier wafers.

[0130] According to a preferred embodiment of the present invention, at least one crack-free SiC component extends more in a first direction than in a second direction, wherein the second direction is orthogonal to the first direction. This embodiment is advantageous in that the SiC component can be a defined SiC block, in particular, can be used as a PVT source material.

[0131] According to a preferred embodiment of the present invention, the first direction is parallel to the length of the body or coaxial with the length of the body or is at an angle of less than 50°, in particular less than 30°, preferably less than 10°, most preferably less than 5° or 0° relative to the length of the body. The first direction is preferably at an angle between 120° and 60°, in particular between 110° and 70°, preferably between 100° and 80°, most preferably between 95° and 85° or 90° relative to the length of the body. The advantage of this embodiment is that the SiC solid can be at an angle different from 0° or 90° relative to the length direction.

[0132] According to a preferred embodiment of the present invention, at least one crack-free SiC component is formed at a distance from the physical structure. This embodiment is advantageous in that the physical structure can be reused because the crack-free SiC component can be taken out from the growth shell.

[0133] According to a preferred embodiment of the present invention, the physical structure comprises less than 5 mass % SiC, preferably less than 2 mass % SiC, more preferably less than 1 mass % SiC. The advantage of this embodiment is that the physical structure can be made of a material that is mainly (mass) or completely (mass) different from SiC.

[0134] According to a preferred embodiment of the present invention, the physical structure comprises more than 90% by mass of graphite, tungsten or carbon fiber composite (CFC) material, preferably more than 95% by mass of graphite, tungsten or carbon fiber composite (CFC) material, more preferably more than 99% by mass of graphite, tungsten or carbon fiber composite (CFC) material, and most preferably more than 99.9% by mass of graphite, tungsten or carbon fiber composite (CFC) material. The advantage of this embodiment is that the physical structure made of graphite, tungsten or carbon fiber composite (CFC) material can be reused and is easy to manufacture.

[0135] According to a preferred embodiment of the invention, at least one crack-free SiC component is at least partially formed as part of the physical structure. This embodiment is advantageous in that the size of the crack-free SiC component is much larger than a SiC component simply removed from the shell.

[0136] According to a preferred embodiment of the present invention, the physical structure comprises more than 90 mass %, preferably more than 95 mass %, particularly preferably more than 99 mass %, and most preferably more than 99.99 mass % SiC, which is in particular polycrystalline SiC, in particular 3C crystal structure. According to a preferred embodiment of the present invention, the deposited SiC is polycrystalline SiC, wherein the deposited SiC forms a volume portion with different crystal structures, wherein the 3C crystal structure (mass and / or volume) is mainly formed. According to a preferred embodiment of the present invention, the volume and / or mass proportion of SiC formed with the 3C crystal structure exceeds the volume and / or 50 mass %, preferably 90 mass %, particularly preferably 99 mass %, and most preferably 99.9 mass % of the deposited SiC. The benefit of this embodiment is that since the shell and the physical structure preferably have the same crystal structure or mainly have the same crystal structure or at least similar crystal structures, the SiC component consisting of the physical structure and part of the shell has very uniform mechanical, electrical and / or chemical properties, so that the SiC component can be used in a wide range of applications. Homogeneous mechanical, electrical and / or chemical properties are understood to mean differences of preferably less than 10%, particularly preferably less than 5%, most preferably less than 1%.

[0137] According to a preferred embodiment of the invention, the method comprises a step of controlled cooling of the deposited SiC and the physical structure. According to a preferred embodiment of the invention, the current through the physical structure is reduced in a defined manner, in particular over a defined time (in particular over 1 hour or preferably over 2 hours or particularly preferably over 3 hours or most preferably over 4 hours). This embodiment is advantageous in that the controlled cooling can limit or reduce the tension caused by the thermal difference. The reduction in thermally induced tension can reduce the initiation and / or propagation of cracks.

[0138] According to a preferred embodiment of the present invention, the deposited SiC comprises less than 2000 ppba of nitrogen, in particular less than 100 ppba of nitrogen. The advantage of this embodiment is that the deposited SiC or SiC component can be used as a source material in a PVT reactor without nitrogen being required, and the single crystal SiC will not be contaminated by nitrogen.

[0139] According to a preferred embodiment of the invention, the method comprises the step of feeding nitrogen into the CVD reactor during deposition to dope the SiC. This embodiment is advantageous in that SiC components with defined electrical properties can be manufactured, for example for use as carrier wafers.

[0140] According to a preferred embodiment of the present invention, the impurity content of substance N in the deposited SiC and / or physical structure is less than 10 ppm (weight), and the impurity content of each B, Al, P, Ti, V, Fe, Ni substance is less than 1000 ppb (weight), especially less than 500 ppb (weight). Preferably, the impurity content of substance N in the deposited SiC and / or physical structure is less than 2 ppb (weight), and the impurity content of each B, Al, P, Ti, V, Fe, Ni is less than 100 ppb (weight). The impurity content of substance Ti in the deposited SiC and / or physical structure is preferably less than 10 ppb (weight). Most preferably, the impurity content of substance N in the deposited SiC and / or physical structure is less than 10 ppm (weight), and the impurity content of all metal Ti, V, Fe, Ni substances is less than 1000 ppb (weight), especially less than 500 ppb (weight). The benefit of this embodiment is that the SiC component or multiple SiC components can be used as a high-quality PVT source material for producing single-crystal SiC crystals with very small amounts of one or more of the substances B, Al, P, Ti, V, Fe, and Ni.

[0141] The above-mentioned object is also achieved by a method for producing a plurality of crack-free workpieces. The method preferably comprises at least one method for producing at least one crack-free SiC component as disclosed herein and a step of dividing at least one crack-free SiC component into a plurality of predetermined components. The benefit of this embodiment is that a plurality of carrier wafers, in particular two or more, preferably five or more, particularly preferably ten or more or up to 50 carrier wafers, can be taken out from one SiC component. The benefit of this embodiment is that the carrier wafers can be taken out much faster than growing each single polycrystalline SiC wafer in a CVD process, so the cost can be significantly reduced by the present invention.

[0142] According to a preferred embodiment of the present invention, the segmentation step preferably includes cutting a defined volume portion using at least one wire saw or weakening a defined volume structure with laser radiation, thereby generating a defined laser segmentation plane, and introducing an external force so that the crack propagates along the defined laser segmentation plane, or implanting ions into a defined volume structure, thereby generating a defined ion segmentation plane, and increasing the pressure in the defined volume by increasing the volume of implanted ions, in particular by heating the defined volume, so that the crack propagates along the defined ion segmentation plane. The benefit of this embodiment is that different segmentation methods can be applied. Therefore, a matching segmentation method can be selected according to the required characteristics. For example, in the case where the contaminants should be very small, a defined laser segmentation plane can be used. If the cost is as low as possible, a wire saw can be used.

[0143] Therefore, segmentation can be performed by different techniques (for example according to WO2021191511, WO2016162428 or US2014038392).

[0144] According to a preferred embodiment of the present invention, the predetermined components are wafers, wherein the height of each wafer is greater than 200 μm, in particular greater than 250 μm, and preferably up to 1000 μm or greater than 1000 μm. The benefit of this embodiment is that the resulting wafer has a high mechanical strength and can therefore be used as a carrier wafer for carrying very small single crystal wafers, in particular very small single crystal SiC wafers. Very small is preferably defined as a thickness of less than 100 μm, and preferably less than 50 μm, and most preferably less than 40 μm.

[0145] According to a preferred embodiment of the present invention, the minimum length of the diameter of the body is 100 mm, preferably 150 mm, particularly preferably 250 mm, and most preferably the minimum length or maximum length is 300 mm. This embodiment is advantageous in that large SiC components can be produced.

[0146] The above object is also achieved by a method for producing a composite substrate. The method preferably comprises at least one method for producing a plurality of crack-free workpieces disclosed herein and the following steps: treating at least one surface of a wafer, in particular grinding and / or fine grinding and / or polishing, to produce a treated surface having at least one defined surface characteristic, and bonding a single crystal SiC wafer to the treated surface. The benefit of this embodiment is that the composite substrate can be produced at low cost, and the production cost of the carrier wafer is significantly reduced.

[0147] 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 1400° C. and 1700° C. This embodiment is advantageous in that the SiC growth substrate can be heated very efficiently.

[0148] 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 chuck. The chuck preferably has a smaller 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.

[0149] According to a preferred embodiment of the present invention, the process chamber is at least surrounded by a bottom plate, a side wall portion and a top wall portion. The advantage of this embodiment is that 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 (particularly 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.

[0150] 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 a carrier gas conforming to the general formula SiH 4-y X y(X=[Cl,F,Br,J] and y=[0..4] of Si gas, 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.

[0151] Alternatively, the first feed medium is a Si feed medium, in particular a feed medium according to the general formula SiH 4-y X y (X = [Cl, F, Br, J] and y = [0..4] Si gas, wherein the gas inlet unit is coupled to at least one 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 the Si feed medium source provides at least Si, in particular the Si feed medium source provides a first feed medium, wherein the first feed medium is a Si feed medium, in particular a carrier gas according to the general formula SiH 4-y X y (X = [Cl, F, Br, J] and y = [0..4] Si gas, and wherein the C feed medium source provides at least C, in particular the C feed medium source 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, wherein the carrier gas medium source provides a third feed medium, wherein the third feed medium is a carrier gas, in particular H2.

[0152] 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.

[0153] 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 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., 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 (especially upstream of the feed gas unit or the medium supply device) to first heat these feed liquids to make them feed gases so as to be mixed with other feed gases.

[0154] 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 1400°C to 1700°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.

[0155] 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.

[0156] 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.

[0157] The advantage of this embodiment is that the throughput of the SiC reactor can be significantly improved by adding an additional SiC growth substrate.

[0158] 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 higher than the minimum feed medium supply amount by at most 30 mass %, at most 20 mass %, at most 10 mass %, at most 5 mass %, or at most 3 mass %. This embodiment is advantageous in that the supply of the feed medium can be controlled according to the desired SiC conditions.

[0159] 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.

[0160] According to another preferred embodiment of the present invention, the control unit is configured to control the supply of the current and 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 because a large amount of SiC solid can be generated.

[0161] 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.

[0162] 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.

[0163] 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.

[0164] 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 1400°C and 1700°C.

[0165] 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.

[0166] 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.

[0167] 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.

[0168] According to another preferred embodiment of the present invention, the bottom plate includes at least one cooling element (in particular a base 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.

[0169] 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 base 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 SiC PVT source material production reactor). In particular, the inner wall of the bell jar can be made of stainless steel. Preferably, this inner wall is 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 base 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.

[0170] 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.

[0171] 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.

[0172] 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.

[0173] 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 the cooling liquid and / or the process chamber can be continuously cooled without loss or contamination.

[0174] 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.

[0175] 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.

[0176] 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.

[0177] 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.

[0178] 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.

[0179] 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.

[0180] 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.

[0181] 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 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.

[0182] 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.

[0183] 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 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 a 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 located 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 level can avoid contamination of the reaction space.

[0184] 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.

[0185] 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.

[0186] 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.

[0187] The above object is also achieved by using a wafer produced according to the method for producing a plurality of crack-free workpieces disclosed herein as a carrier wafer, the carrier wafer being used to carry a single crystal SiC wafer, wherein the height of the single crystal SiC wafer is less than 50 μm. The benefit of this embodiment is that the production cost of the carrier wafer is very low.

[0188] The above objects can also be achieved by a carrier wafer, in particular a carrier wafer produced according to the method for producing a plurality of crack-free workpieces disclosed herein, wherein the predetermined components are preferably wafers, wherein the height of each wafer is greater than 200 μm, in particular greater than 250 μm, and preferably up to 1000 μm or greater than 1000 μm, and / or wherein the diameter of the body has a minimum length of 100 mm, preferably a minimum length of 150 mm, particularly preferably a minimum length of 250 mm, and most preferably a minimum or maximum length of 300 mm, wherein the carrier wafer has a diameter of at least 7.5 cm, a height of at least 200 μm, and wherein the carrier wafer is mainly formed of a 3C crystal structure. The advantage of this embodiment is that the carrier wafer can have a large size, thereby allowing it to be bonded to a single crystal wafer of the same size.

[0189] According to a preferred embodiment of the present invention, the 3C crystal structure is doped with nitrogen, in particular with nitrogen doping exceeding 2000 ppba, and has a resistivity of less than 0.01 Ohm cm. This embodiment is advantageous in that it can provide preferred mechanical and electrical properties to allow the use of the carrier wafer in a variety of different use cases.

[0190] According to a preferred embodiment of the present invention, the grain orientation of the 3C crystal structure varies between 0° and 80°. The advantage of this embodiment is that the SiC component or carrier wafer is taken out from the growth shell or from one quarter of the growth shell.

[0191] According to a preferred embodiment of the present invention, the grain orientation of the 3C crystal structure varies by more than 80°. This embodiment is advantageous in that the SiC component or carrier wafer is taken out from at least two quarters of the growth shell, preferably also from the center of the physical structure.

[0192] The above objects can also be achieved by a crack-free SiC component, in particular by a crack-free SiC component produced according to the method for producing at least one crack-free SiC component disclosed herein. The crack-free SiC component is mainly formed of a 3C crystal structure, wherein the size of the crack-free SiC component is at least 2 cm×2 cm×1 cm. The advantage of this embodiment is that the crack-free component can be used to produce multiple or different or large components or devices.

[0193] According to a preferred embodiment of the present invention, the grain orientation of the 3C crystal structure varies between 0° and 80°, preferably below 70°, most preferably below 60°, or above 90°, preferably above 120°, or particularly preferably above 160°, most preferably above 220°. This embodiment is beneficial in that one or more SiC components can be taken out according to the desired grain orientation.

[0194] According to a preferred embodiment of the present invention, the density of the crack-free SiC component is greater than 3 g / cm 3 The present embodiment is beneficial in that the mechanical and / or electrical and / or chemical properties of the crack-free SiC component are enhanced. Due to the better mechanical stability, the carrier wafer can be thinner, thus reducing energy consumption.

[0195] The above-mentioned object can also be achieved by a method for producing a predefined PVT source material component, which is used to fill a source material receiving space of a PVT reactor. The PVT source material is SiC, wherein the SiC mainly has a 3C crystal structure. The method preferably includes at least the following steps: setting up a CVD reactor, wherein the CVD reactor includes at least one SiC growth substrate, wherein the at least one SiC growth substrate includes a body, a first power connection and 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 to conduct electricity into the body to heat the body, wherein the second power connection is configured to conduct electricity conducted into the body through the first power connection out of the body, wherein the body forms a physical structure, wherein the physical structure forms a deposition surface for depositing SiC. The method preferably also includes the step of growing a SiC solid by depositing SiC on the physical structure in the CVD reactor, wherein at least one SiC component is a part of the SiC solid, wherein the minimum thickness of the deposited SiC is at least 1 cm. The method preferably also includes the step of removing at least one SiC component from the SiC solid, wherein the cross-sectional size of at least one SiC component is at least 4 cm 2 , preferably at least 8cm 2 , more preferably at least 12 cm 2 , with a thickness of at least 0.1 cm, preferably at least 1 cm, and more preferably at least 2 cm, wherein the shape of at least one SiC component is configured to fill at least 75% of the volume of a defined source material receiving space in a defined PVT reactor, or wherein the shape of at least one SiC component is configured to fill at least 75% of the volume of a defined source material receiving space in a defined PVT reactor together with at least one other SiC component having the same shape. The benefit of this embodiment is that due to the block shape of the SiC component, more mass of SiC can be provided within the defined receiving space of the PVT reactor compared to powder as source material, thereby allowing more single crystal SiC crystals to be grown during a single production run.

[0196] The above-mentioned purpose can also be achieved by a SiC component, in particular, a SiC component produced according to a method for producing a predefined PVT source material component, which is used to fill the source material receiving space of a PVT reactor, wherein the SiC component is mainly formed by a 3C crystal structure, and wherein the size of the crack-free SiC component is at least 2cm×2cm×1cm.

[0197] According to a preferred embodiment of the present invention, the grain orientation of the 3C crystal structure varies between 0° and 80°, preferably below 70°, most preferably below 60°, or above 90°, preferably above 120°, or particularly preferably above 160°, most preferably above 220°. This embodiment is beneficial in that one or more SiC components can be taken out according to the desired grain orientation.

[0198] According to a preferred embodiment of the present invention, the density of the SiC component is greater than 3g / cm 3 The present embodiment is beneficial in that the mechanical and / or electrical and / or chemical properties of the crack-free SiC component are enhanced. Due to the better mechanical stability, the carrier wafer can be thinner, thus reducing energy consumption.

[0199] The above objects are also achieved by a method for producing SiC material. The method preferably comprises the following steps: providing at least one furnace device for growing SiC crystals, wherein the furnace device comprises a furnace unit, wherein the furnace unit comprises a furnace shell having an outer surface and an inner surface; at least one crucible unit, wherein the crucible unit is arranged inside the furnace shell, wherein the crucible unit comprises a crucible shell, wherein the shell has an outer surface and an inner surface, wherein the inner surface at least partially defines a crucible volume, wherein a receiving space for receiving a solid SiC source material is arranged or formed inside the crucible volume, wherein a seed holder for fixing a specific seed wafer is arranged inside the crucible volume unit), wherein the furnace shell inner wall and the crucible shell outer wall jointly define the furnace volume; at least one heating unit for heating source material, wherein a receiving space for receiving the source material is at least partially arranged below the seed clamping unit; arranging the source material in the receiving space in the crucible shell, wherein the source material is made of exactly one SiC component, wherein the source material fills at least 75% and preferably at least 90%, more preferably at least 95%, most preferably at least 98% of the volume of the receiving space, or wherein the source material is made of a plurality of SiC components, which are preferably produced according to the method for producing predefined PVT source material components disclosed herein, so as to fill the source material receiving space of the PVT reactor, wherein at least a plurality of SiC components, preferably all SiC components, have the same shape, wherein the source material fills at least 75%, preferably at least 90%, more preferably at least 95%, most preferably at least 98% of the volume of the receiving space; heating the source material, and feeding a carrier gas into the crucible shell. This solution is beneficial in that a larger single-crystal SiC crystal can be produced in one run, since a greater mass of SiC can be arranged in the receiving space compared to the source material in the prior art.

[0200] Document PCT / EP2021 / 082340 discloses a furnace device that can be used to implement the above method according to the present invention. The subject matter of PCT / EP2021 / 082340 is fully incorporated into the present subject matter by reference.

[0201] 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.

[0202] 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. BRIEF DESCRIPTION OF THE DRAWINGS

[0203] Figure 1 A first example of a CVD reactor according to the invention is schematically shown,

[0204] Figure 2 A second example of a CVD reactor according to the invention is schematically shown,

[0205] Figure 3 A third example of a CVD reactor according to the invention is schematically shown,

[0206] Figure 4a Schematic diagram of the CVD reactor before production operation and

[0207] Figure 4b Schematic diagram of a CVD reactor after a production run,

[0208] Figure 5 Schematic diagram of the production process of SiC components, SiC carrier wafers and composite wafers,

[0209] Figure 6 A PVT reactor is shown which can be operated using source materials produced according to the invention,

[0210] Figure 7 shows a PVT reactor filled with large solid SiC source material components,

[0211] and

[0212] Figure 8a / Figure 8bshows the different locations of SiC components within the overall CVD SiC structure,

[0213] Figure 9a-9d shows the production steps of the composite wafer according to the present invention,

[0214] Fig.9e The optional further step of growing an epitaxial layer on the composite wafer is further shown,

[0215] Figure 10a-Figure 10d Shown with Figure 9a-9d A similar approach, where Figure 9a-9d The thin substrate layer is thicker than the thin substrate layer to provide a composite wafer that can be used for device production without the need for an epitaxial layer production step.

[0216] Fig.11 A high-resolution photograph showing the crystal structure of the second substrate,

[0217] Fig.12 Shows the improved Fig.11 , to represent the main growth direction (radial direction) and multiple orientations of large crystals,

[0218] Fig.13a shows the conventional growth of a carrier wafer,

[0219] Figure 13b-Figure 13d shows the growth direction in a particular cross section,

[0220] Fig.14 Shows Figure 3 A magnified cross section of a crystallite with the length and boundaries highlighted.

[0221] Fig.15a / Fig.15b shows the linear elements produced during the growth process,

[0222] Fig.16 An example of a CVD SiC device according to the present invention is shown, wherein an exhaust gas treatment unit is also shown,

[0223] Fig.17 An example of a CVD SiC apparatus according to the present invention is shown, wherein an exhaust gas recovery unit is also shown,

[0224] Fig.18 An example of a feed gas unit according to the invention with three gases is shown,

[0225] Fig.19 An example of a feed gas unit according to the invention with two gases is shown,

[0226] Fig. 20shows an example of an exhaust gas treatment unit according to the invention,

[0227] Fig.21 An example of an exhaust gas recovery unit according to the present invention is shown,

[0228] Fig. 22 An example of a preferred system arrangement according to the present invention is shown,

[0229] Fig.23 shows an example of a comminution unit, and

[0230] Fig.24 An example of an etching unit is shown,

[0231] Figure 25a-Figure 25c shows the orientation of crystallites inside different SiC growth substrates,

[0232] Fig.26a / Figure 26b shows the orientation of the crystallites inside and outside the SiC solid,

[0233] Fig. 27 Another example of a grown SiC solid is shown. DETAILED DESCRIPTION

[0234] Figure 1 An example of a manufacturing device 850 for producing SiC material, in particular 3C-SiC material, is shown. This device 850 or reactor 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 of a first source fluid (in particular a first source liquid or a first source gas), wherein the first source fluid preferably includes Si, in particular includes, for example, silane / chlorosilane with a general composition of SiH4-mClm or an organochlorosilane 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 of a second source fluid (in particular 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.

[0235] 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.

[0236] 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 or a SiC growth substrate is arranged in the process chamber 856, and preferably a plurality of deposition elements 857 are arranged, wherein Si and C are deposited from the evaporated fluid mixture at the deposition element 857 and form SiC.

[0237] 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) in terms of data and / or signal technology.

[0238] 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 via 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.

[0239] 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.

[0240] Figure 2A 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, which can be pressurized to a pressure of at least 6 bar, particularly 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 bottom plate 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.

[0241] 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 1400°C to 1700°C, preferably in the temperature range of 1400°C to 1650°C, and most preferably in the temperature range of 1400°C to 1600°C). The chuck 208 preferably achieves this temperature gradient by continuously reducing the cross-sectional area for 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.

[0242] 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 856. 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 by the incoming feed gas mixture 1160 through the exhaust outlet.

[0243] 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.

[0244] 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 .

[0245] Therefore, if Figure 1 , 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 supplying 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).

[0246] 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.

[0247] 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.

[0248] 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.

[0249] Figure 4a Shown according to Figures 1 to 3 850, wherein the reactor 850 comprises at least one SiC growth substrate 857, in particular two or more SiC growth substrates 857. The SiC growth substrate 857 is preferably made of SiC (in particular polycrystalline 3C SiC). The reactor 850 may preferably include an optional nitrogen inlet for supplying nitrogen to the process chamber 856 for doping the SiC solid during growth, in particular doping the SiC shell or "outer part 2602" (see Fig.26a / b).

[0250] Figure 4b Shows the production run and after cooling Figure 4a Reference numeral 2299 refers to the entire structure including the SiC growth substrate 857 and the growth shell 211 .

[0251] according to Figures 1 to 4aThe CVD reactor is used to grow SiC material (especially SiC solid) to produce SiC carrier wafer 2322. Such SiC carrier wafer 2322 preferably has a height between 200 μm and 500 μm, a diameter of at least 7.5 cm, preferably at least 10 cm, and most preferably at least 12 cm or 15 cm. Additionally or alternatively, the SiC material (especially SiC solid, especially SiC carrier wafer 2322) is mainly formed of a 3C crystal structure, wherein the SiC carrier wafer 2322 is preferably doped, especially doped with nitrogen, especially doped with more than 2000 ppba, but preferably less than 10 19 Nitrogen atoms / cm 3 , particularly preferably less than 10 18 Nitrogen atoms / cm 3 , most preferably less than 10 17 Nitrogen atoms / cm 3 The resistivity of the SiC carrier wafer 2322 is preferably less than 0.03 Ohm cm, preferably less than 0.02 Ohm cm, and most preferably less than 0.01 Ohm cm.

[0252] The SiC carrier wafer 2322 preferably includes at least one or exactly one inner portion 2600 (see Fig.26a or Figure 26b ), in particular a central inner portion, and wherein the SiC carrier wafer 2322 preferably includes an outer portion 2602 (see Fig.26a or Figure 26b ), wherein the outer portion 2602 surrounds the inner portion 2600. The inner portion is composed of a portion of the SiC growth substrate 857, wherein the inner portion 2600 is preferably formed mainly of a 3C crystal structure. The outer portion 2602 is preferably formed mainly of a 3C crystal structure and includes crystallites 2414 extending in the length direction of a single crystallite for more than 5 μm, in particular for more than 10 μm, preferably for more than 20 μm, particularly preferably for more than 50 μm, most preferably up to 500 μm or up to 300 μm (see Figures 9a-10d and Fig.26a / b). The curvature of the carrier wafer is preferably less than 50 μm, in particular less than 20 μm, and / or wherein the curvature of the carrier wafer is preferably less than 50 μm, in particular less than 20 μm.

[0253] Figure 5Also shown is the entire structure 2299 including one or more crack-free regions 2305. The crack-free region 2305 or the crack-free SiC component 2300 is preferably formed between the first plane 2302 and the second plane 2304, wherein the first plane 2302 and the second plane 2304 are preferably parallel to each other and are arranged at a distance of more than 200 μm or preferably more than 500 μm or particularly preferably more than 2500 μm or more preferably more than 5000 μm or most preferably more than 10000 μm or up to 10000 μm or at a distance between 500 μm and 50000 μm. Arrow 2328 indicates a rough sawing step for removing the crack-free SiC component 2300 from the structure 2299 and / or removing the crack-free SiC component 2300 from the shell 211. In a further step 2330, the crack-free SiC component 2300 is cut into multiple wafers 2322, in particular SiC carrier wafers, and preferably into more than two wafers 2322, and particularly preferably into more than 5 or at most 5 wafers 2322, or more preferably into more than 10 or at most 10 wafers 2322, or most preferably into more than 15 or at most 15 wafers 2322, or into 2 to 50 wafers 2322.

[0254] It has been found that large crystallites, especially large crystallites with a length of more than 5 μm, more than 10 μm, more than 30 μm, or more than 50 μm, can increase the stability of the structure, thereby compensating for tension. However, due to a small thermal mismatch (especially a temperature difference of less than 300K inside the SiC solid), the tension is further reduced, resulting in a crack-free area inside the SiC solid. When an alternating current is applied, the temperature difference between the SiC solid core and the growth surface can be minimized. Additionally or alternatively, the growing SiC solid is preferably heated for a defined time after the growth is completed, wherein the defined time is greater than 1 h, particularly greater than 2 h, preferably greater than 3 h, particularly preferably greater than 5 h, most preferably greater than 10 h or at most 24 h, wherein within the defined time, the electrical energy used to heat the SiC solid is continuously and / or gradually reduced. Therefore, due to the above-mentioned measures, the tension inside the SiC solid is reduced or compensated, so that a larger crack-free area can be formed inside the SiC solid or as part of the SiC solid. "Larger crack-free areas" preferably describe one or more areas within the SiC solid that are large enough to allow the removal of at least two, preferably at least five, most preferably at least 10 or 20 or at most 50 or 100 SiC carrier wafers having a diameter greater than 6 cm, in particular greater than 7.5 cm or greater than 10 cm and a height of up to 500 μm.

[0255] In step 2332, one, more than one or all SiC carrier wafers 2322 are preferably processed, in particular finely ground. After the finely grinding step, a polishing step (reference numeral 2336) is preferably performed. Reference numeral 2317 denotes a SiC single crystal, wherein according to reference numeral 2334, a wafer, in particular a single-crystalline wafer having a thickness of less than 50 μm, is removed from the SiC single crystal 2317. Reference numeral 2338 denotes a bonding step for bonding the single-crystalline SiC wafer 2334 to the SiC carrier wafer 2322 and thereby generating a bonded structure 2320. The height of the SiC carrier wafer 2322 is preferably between 200 μm and 500 μm, and the diameter is at least 7.5 cm, preferably at least 10 cm, and most preferably at least 12 cm or 15 cm. Additionally or alternatively, the SiC carrier wafer 2322 is mainly formed of a 3C crystal structure, wherein the SiC carrier wafer 2322 is preferably doped, in particular doped with nitrogen, in particular doped with more than 2000 ppba, but preferably less than 10 19 Nitrogen atoms / cm 3 , particularly preferably less than 10 18 Nitrogen atoms / cm 3 , most preferably less than 10 17 Nitrogen atoms / cm 3 The resistivity of the SiC carrier wafer 2322 is preferably less than 0.03 Ohm cm, preferably less than 0.02 Ohm cm, and most preferably less than 0.01 Ohm cm.

[0256] The SiC carrier wafer 2322 preferably includes at least one or exactly one inner portion 2600 (see Fig.26a or Figure 26b ), in particular a central inner portion, and wherein the SiC carrier wafer 2322 preferably includes an outer portion 2602 (see Fig.26a or Figure 26b ), wherein the outer portion 2602 surrounds the inner portion 2600. The inner portion is composed of a portion of the SiC growth substrate 857, wherein the inner portion 2600 is preferably formed mainly of a 3C crystal structure. The outer portion 2602 is preferably formed mainly of a 3C crystal structure and includes crystallites 2414 extending in the length direction of a single crystallite for more than 5 μm, in particular for more than 10 μm, preferably for more than 20 μm, particularly preferably for more than 50 μm, most preferably up to 500 μm or up to 300 μm (see Figures 9a-10d and Fig.26a / b). The curvature of the carrier wafer is preferably less than 50 μm, in particular less than 20 μm, and / or wherein the curvature of the carrier wafer is preferably less than 50 μm, in particular less than 20 μm.

[0257] Therefore, the present invention preferably relates to a method for producing at least one crack-free SiC component, the method comprising at least the following steps: setting up a CVD reactor 850, wherein the CVD reactor 850 includes at least one SiC growth substrate 857, a first power connection 859a and a second power connection 859b, wherein the SiC growth substrate 857 has a SiC growth substrate 857 length ML, wherein the SiC growth substrate 857 length ML extends between the first power connection 859a and the 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 through the first power connection 859a into and out of the SiC growth substrate 857, wherein the SiC growth substrate 857 forms a deposition surface 861 for depositing SiC. Additionally, it involves the step of growing SiC solid 211 by depositing SiC on deposition surface 861 in CVD reactor 850, wherein at least one crack-free SiC component 2300 is a part of SiC solid 211, wherein the deposited SiC has a minimum thickness of at least 1 cm, wherein at least one SiC component 2300 is formed between a first plane 2302 and a second plane 2304, wherein the first plane 2302 is orthogonal to the length ML of SiC growth substrate 857, and wherein the second plane 2304 is orthogonal to the length ML of SiC growth substrate 857, wherein a distance D between the first plane 2302 and the second plane 2304 is at least 1%, preferably at least 2%, and more preferably at least 5% of the length ML of SiC growth substrate 857. Additionally, it involves the step of removing at least one crack-free SiC component 2300 from SiC solid 211, wherein the cross-sectional dimension of the at least one crack-free SiC component is at least 4 cm 2 , preferably at least 8 cm 2 , more preferably at least 12 cm 2 , and a thickness of at least 0.1 cm, preferably at least 1 cm, more preferably at least 2 cm. The first power connection 859a and the second power connection 859b preferably connect the SiC growth substrate 857 to a power source, particularly an electrical power source, particularly an alternating current source.

[0258] Figure 6A furnace unit 102 is shown. The furnace unit 102 preferably comprises a furnace shell 108 having an outer surface 242 and an inner surface 240, at least one crucible unit 106, and at least one heating unit 124 for heating a source material 120. The crucible unit 106 is preferably arranged within the furnace shell 108, wherein the crucible unit 106 comprises a crucible shell 110, wherein the shell 110 has an outer surface 112 and an inner surface 114, wherein the inner surface 114 at least partially defines a crucible volume 116, wherein a receiving space 118 for receiving a solid SiC source material 120 is arranged or formed within the crucible volume 116, wherein a seed holding unit 122 for fixing a defined seed wafer 18 is arranged within the crucible volume 116, wherein the furnace shell inner wall 240 and the crucible shell outer wall 112 define the furnace volume 104, wherein the receiving space 118 for receiving the source material 120 is at least partially arranged below the seed holding unit 122. The receiving space 118 preferably has a defined volume to receive a maximum volume of source material 120. Using a source material 120 having a higher density to operate the furnace unit 102, in particular a PVT reactor, allows larger SiC crystals to be produced in one run compared to a source material having a lower density. Therefore, it is very beneficial to use a source material 120 made of exactly one SiC component 2300 according to the present invention, in the case where the source material fills at least 75%, preferably at least 90%, more preferably at least 95%, and most preferably at least 98% of the volume of the receiving space 118. Alternatively, it is beneficial to use a plurality of SiC components, in the case where at least a plurality, preferably all a plurality of SiC components 2300 have the same shape, in which the source material 120 fills at least 75%, preferably at least 90%, more preferably at least 95%, and most preferably at least 98% of the volume of the receiving space 118.

[0259] Figure 7 The entire CVD SiC structure 2299 is shown, as well as the step of rough sawing 2328 the CVD SiC structure 2299. The rough sawing 2328 results in the formation of SiC components 2301 in a defined shape, wherein the defined shape is such that more than 80% by volume, preferably more than 90% by volume, or more preferably more than 95% by volume of a receiving space of a PVT reactor can be filled with one or more SiC components 2301, wherein the volume of each SiC component is greater than 1 cm×1 cm×1 cm, preferably greater than 2 cm×1 cm×1 cm, and more preferably greater than 2 cm×2 cm×1 cm.

[0260] The source material 120 is divided into different components by the "dashed white lines" representing the SiC components 2301. The SiC components 2301 may be crack-free, but need not be.

[0261] Therefore, the entire CVD SiC structure 2299 can be divided into a crack-free SiC component 2300 and a cracked SiC component 2301, wherein the crack-free SiC component 2300 can be used to produce SiC devices (such as carrier wafers 2322), while the cracked SiC component 2301 can be used as a high-density source material (especially in a PVT reactor) to produce single crystal SiC.

[0262] Figure 8a and Figure 8b The location of crack-free SiC components within the overall CVD SiC structure 2299 is schematically shown.

[0263] according to Figure 8a , the component 2300 is arranged in the shell 211 of the CVD SiC structure 2299. Therefore, most of the grain orientations are arranged at an angle less than 90°, preferably less than 100°.

[0264] Reference numeral 2326 schematically represents a first "quarter" angle. Thus, the CVD SiC structure 2299 can actually be divided into four quarters. In the case where the grain orientation of the SiC component 2300 is less than 90°, it is preferred to take the SiC component 2300 out of one quarter.

[0265] Figure 8b It is shown that most of the grains are oriented at angles greater than 90°, preferably greater than 180°, and most preferably greater than 270°. Figure 8a and Figure 8b The SiC component 2300 shown in FIG. 2 can be used as a SiC growth substrate 857 for use in any of the CVD reactors 850 described herein.

[0266] Figure 9a A polycrystalline SiC component 2300 (particularly a crystal ingot or a crystal rod) is shown. Reference numeral 2414 schematically denotes a crystallite oriented at least mainly in a radial direction (R), wherein the length of the crystallite 2414 is greater than 5 μm, particularly greater than 10 μm, most preferably greater than 30 μm. Line 2416 schematically shows a splitting plane along which the SiC component 2300 is divided into two components. In the example shown, the smaller part of the SiC component 2300, i.e. the part above the line 2416, forms a "second substrate" 2322 or a SiC carrier wafer 2322 according to the invention.

[0267] Figure 9bA first substrate 2317 and a second substrate 2322 according to the present invention are shown. The first substrate 2317 is preferably a single crystal SiC crystal, and the second substrate is preferably a polycrystalline SiC structure or a SiC carrier wafer 857, wherein both the first substrate 2317 and the second substrate 2322 are at least partially (volume) and preferably mainly (volume) or most preferably completely grown in the radial direction.

[0268] The first substrate 2317 preferably includes ions arranged on the layer 2418 for separating the thin substrate layer 2318 from the first substrate 2317. The ions can expand during subsequent heating and locally cause the crystal structure to break, thereby dividing the first substrate 2317 into several parts. This segmentation is called a "smart cutting process".

[0269] Fig.9c The first substrate 2317 and the second substrate 2322 bonded together are shown. Arrow "H" indicates the height direction, that is, the direction in which the top surface 2406 of the second substrate 2322 and the bottom surface of the second substrate 2408 are arranged spaced apart from each other, and the direction in which the top surface of the first substrate 2400 and the bottom surface of the first substrate 2402 are arranged spaced apart from each other.

[0270] Figure 9d The composite wafer 2320 of the present invention is shown after the thin substrate layer 2318 has been singulated from the first substrate 2317.

[0271] Fig.9e An optional step of growing an epitaxial layer 2319 on top of the thin substrate layer 2318 is shown.

[0272] The epitaxial layer 2319 is a single crystal SiC crystal layer 2319 produced on a thin substrate layer 2318, wherein the single crystal SiC crystal layer 2319 is grown by an epitaxial method, wherein the thickness of the thin substrate layer 2318 is less than 1 μm, and the thickness of the single crystal SiC crystal layer 2319 is preferably 0.5 μm to 20 μm, in particular 1 μm to 15 μm or 1 μm to 12 μm, or preferably 2 μm to 15 μm or 2 μm to 12 μm.

[0273] Therefore, given that Figure 9a -Figure d and Fig.10a- Figure d, the method for producing a compound (or composite wafer) or a multi-substrate wafer 2320 according to the present invention preferably includes the following steps: providing a first substrate, providing a second substrate 2322, and bonding the first substrate 2317 to the second substrate 2322. The first substrate 2317 is preferably a single-crystal SiC crystal, wherein the single-crystal SiC crystal 2317 is formed by a crystal structure, wherein the crystal structure defines a c-axis, wherein the crystal structure grows perpendicular to the c-axis, wherein the single-crystal SiC crystal 2317 has a preferably flat top surface 2400, a preferably flat bottom surface 2402, and a connecting surface 2404 connecting the top surface 2400 and the bottom surface 2402, wherein the c-axis is at an angle between 0° and 8°, preferably between 2° and 6°, relative to a normal on the top surface 2400. The second substrate 2322 preferably comprises or consists of polycrystalline SiC, in particular 3C-SiC, wherein at least 60% by volume of the polycrystalline SiC is grown in the radial direction, wherein the second substrate 2322 has a resistivity of less than 15 mOhm cm, bonding the first substrate 2317 and the second substrate 2322 together. The height of the second substrate or SiC carrier wafer 2322 is preferably between 200 μm and 500 μm, and the diameter is at least 7.5 cm, preferably at least 10 cm, most preferably at least 12 cm or 15 cm. Additionally or alternatively, the SiC carrier wafer 2322 is mainly formed of a 3C crystal structure, wherein the SiC carrier wafer 2322 is preferably doped, in particular doped with nitrogen, in particular doped with more than 2000 ppba nitrogen, but preferably less than 10 19 Nitrogen atoms / cm 3 , particularly preferably less than 10 18 Nitrogen atoms / cm 3 , most preferably less than 10 17 Nitrogen atoms / cm 3 The resistivity of the SiC carrier wafer is preferably less than 0.03 Ohm cm, preferably less than 0.02 Ohm cm, most preferably less than 0.01 Ohm cm.

[0274] The SiC carrier wafer 2322 preferably includes at least one or exactly one inner portion 2600 (see Fig.26a or Figure 26b ), in particular a central inner portion, and wherein the SiC carrier wafer 2322 preferably includes an outer portion 2602 (see Fig.26a or Figure 26b), wherein the outer part 2602 surrounds the inner part 2600. The inner part consists of a portion of the SiC growth substrate 857, wherein the inner part 2600 is preferably mainly formed of a 3C crystal structure. The outer part 2602 is preferably mainly formed of a 3C crystal structure and includes crystallites 2414 extending in the length direction of a single crystallite for more than 5 μm, in particular more than 10 μm, preferably more than 20 μm, particularly preferably more than 50 μm, most preferably up to 500 μm or up to 300 μm. The curvature of the carrier wafer is preferably less than 50 μm, in particular less than 20 μm, and / or wherein the warpage of the carrier wafer is preferably less than 50 μm, in particular less than 20 μm.

[0275] The method preferably also includes the step of converting the first substrate 2317 into a thin substrate layer 2318 by reducing the thickness of the first substrate 2317 to less than 20 μm, wherein the step of reducing the thickness of the first substrate 2317 to less than 20 μm is performed after the first and second substrates 2322 are bonded together.

[0276] Therefore, the present invention relates to a multi-substrate wafer 2320. The multi-substrate wafer 2320 comprises at least a first substrate 2317 and a second substrate, wherein the first substrate 2317 and the second substrate 2322 are bonded together, wherein the first substrate 2317 is a single-crystalline SiC crystal 2317, wherein the second substrate 2322 comprises polycrystalline 3C-SiC, wherein at least 30% by volume, in particular at least 50% by volume, preferably at least 70% by volume of the polycrystalline 3C-SiC grows in a radial direction around at least one or exactly one central element 857, wherein the central element 857 preferably comprises SiC or consists of SiC, wherein the second substrate 2322 has a resistivity of less than 15 mOhm cm, wherein the second substrate 2322 is at least doped with nitrogen, wherein greater than 10% by volume of the second substrate 2322 exists inside the second substrate 2322 due to doping. 17 Nitrogen atoms / cm 3 of nitrogen.

[0277] Fig.10a and Figure 9a correspond.

[0278] Fig.10b A first substrate 2317 is shown, which includes an ion layer 2418 for removing a thin layer 2318, wherein Figure 9b In comparison, the arrangement distance of ion layer 2418 is larger.

[0279] Fig.10a - Figure d shows that the thickness of the thin substrate layer 2318 is preferably between 2 μm and 20 μm, in particular between 5 μm and 12 μm, wherein more preferably, the thickness of the thin substrate layer 2318 is between 1 μm and 2 μm. 3 Includes 1015 -10 16 Therefore, in the case of an electronic device such as a Schottky diode, the substrate layer 2318 can be used as an n-type drift region, and the second substrate can be used as an n+ substrate.

[0280] Fig.11 A high-resolution photograph of a cross section of the second substrate 2322 is shown. Reference numeral 2414 refers to crystallites having a length extension (preferably in the image plane) greater than 5 μm, whereas reference numeral 2415 refers to crystallites having a length extension (preferably in the image plane) less than 5 μm.

[0281] Fig.12 A modified version of system 11 is shown. A plurality of large crystallites 2414 are identified (preferably in the image plane) and their length directions are indicated by dashed lines. The general radial direction R indicates the direction of expansion of the polycrystalline SiC during growth.

[0282] Fig.13a A prior art carrier wafer 2500 is shown. The carrier wafer 2500 is grown by epitaxy in a flat growth substrate 2502. The growth direction 2504 is in one direction only or perpendicular to the plane of the growth substrate 2502. Figure 5 a also schematically shows that the length direction of a plurality of large crystallites 2506 is mainly oriented in one direction. Most or all crystallites in the SiC carrier wafer 2500 are oriented in the growth direction and are therefore parallel to the height direction, wherein the two main surfaces 2508 and 2510 are more than 300 μm apart from each other in the height direction, wherein the main surfaces 2508 and 2510 are flat and parallel to each other.

[0283] Fig.13b It is shown that the central element or SiC growth substrate 857 provides a growth surface extending in 3D space, so the growth surface does not only extend in 2D space.

[0284] Fig.13b and Fig.13c / Figure d shows that the central element / SiC growth substrate 857 can have a variety of shapes.

[0285] about Fig.13b , Fig.13c and Fig.13d, it must be understood that "radial" applies not only to the case where the central element / SiC growth substrate 857 has a circular shape (cross-section), but also to the case where a "radius" is present. In the context of the present invention, "radial" describes the growth direction of the polycrystalline structure along the side surface or growth plane during expansion. Therefore, the radial direction R of the polycrystalline structure 2322 can preferably be determined for a plurality of portions of the polycrystalline structure 2322, wherein each portion 2420 preferably includes the radial direction R of the respective portion 2420 at its center, wherein the width of the respective portion 2420 is preferably less than 500 μm, in particular less than 300 μm, preferably less than 100 μm, wherein the alignment between the radial direction R of the polycrystalline structure 2322 and the length direction L of a single crystallite 2414 (the length direction L extending for more than 5 μm, in particular more than 10 μm, preferably more than 20 μm) is limited to the crystallites 2414 present in the respective portion 2420 and the radial direction R of the respective portion 2420.

[0286] The central element / SiC growth substrate 857 is preferably also grown in a radial direction, in particular taken from a radially grown portion of the SiC component 2300 (in particular an ingot or a rod).

[0287] Fig.13d The variation in the orientation of large crystallites 2414 along the circumferential direction of the polycrystalline crystal structure 2322 is shown.

[0288] Fig.14 Shows Fig.11 24. The portion shows a crystallite 2414, wherein a boundary 2422 of the crystallite 2414 is marked with a thin white line. A straight white line connects two points of the crystallite 2414 that are arranged at the greatest distance from each other in their respective planes. Thus, the white line represents the length direction L of the crystallite 2414. The definition of the length direction L of the crystallite 2414 applies to all embodiments of the present invention.

[0289] Fig.15a and Fig.15b It is schematically shown that there may be ribbon-like or line-like or straight elements 2412 representing growth rings or growth lines in the grown SiC component 2300. A plurality of line-like, in particular at least partially curved, in particular at least partially circular or at least partially arcuate and / or at least partially straight elements 2412 are preferably formed at least 1 nm inside the preferably planar top surface 2406, the preferably planar bottom surface 2408 and the connecting surface 2410.

[0290] The length of at least one, preferably at least two, curved, circular, straight and / or arcuate elements 2412 in the circumferential direction of the second substrate 2322 is at least 10 nm, in particular at least 20 nm or 50 nm or 100 nm. Preferably, at least one or two curved, circular, straight and / or arcuate elements 2412 extend completely around the central element / SiC growth substrate 857.

[0291] The thread-like or strip-like or straight-line elements are preferably generated by changes in the growth surface temperature and / or feed gas composition.

[0292] In a preferred embodiment of the present invention, Fig.16 A preferred main unit of a SiC (particularly UPSiC (Ultra Pure SiC)) production reactor 850 is shown, in particular for the production of SiC, wherein, according to this embodiment, the SiC production reactor 850 comprises a SiC exhaust gas treatment device. The separated feed gases 98 are pumped from their respective storage units to a feed gas unit 1000, where they are mixed in the desired mass ratio to form a feed gas mixture 198. The feed gas mixture 198 is sent to a CVD unit or CVD reactor or SiC production reactor 850 (particularly a SiC PVT source material production reactor), and a deposition reaction takes place therein, thereby producing SiC rods 298 and exhaust gas 296. The exhaust gas 296 is conveyed to an exhaust gas treatment unit 500, in which scrubber inlet water 496 is preferably used to remove Si-containing compounds and HCl from the exhaust gas 296. The scrubber outlet water 598 containing the absorbed Si-containing compounds and HCl is discharged, and the scrubbed exhaust gas is preferably sent to a flare for combustion. The flare may utilize a flare combustion gas 497 (e.g., natural gas) to achieve combustion of the scrubbed exhaust gas and discharge the resulting flare exhaust gas. Figure 1 , Figure 2 , Figure 3 The CVD reactor 850 of FIG. 4 may also be equipped with or coupled to an exhaust gas treatment device or recovery unit disclosed herein.

[0293] The SiC rods 298 are preferably conveyed to a comminution unit 300, where they are comminuted and reduced to a desired form factor, such as particles. In addition, any foreign material (such as graphite seed rods) is preferably separated from the SiC material in order to minimize any residual contamination from the material, for example by heating the SiC to at least 1500°C to burn off any residual graphite. The SiC particles (especially UPSiC particles) 398 are preferably conveyed to an acid etching unit 400, where they are preferably subjected to an additional or alternative surface cleaning step, namely acid etching in an acid bath. Finally, the SiC (especially UPSiC) etched particles 498, which have been cleaned and dried after the acid bath treatment, can be packaged and shipped.

[0294] Alternatively, follow Figure 5 The method described processes SiC rod 298 .

[0295] In another preferred embodiment of the present invention, Fig.17 The main units of the entire CVD SiC (especially UPSiC) device 850 are shown, especially according to Figure 1 , 2 , 3, and 4, in which case the unit has an exhaust gas recovery function. Here, the exhaust gas 296 is discharged from the CVD unit or CVD reactor or SiC production reactor (particularly the SiC PVT source material production reactor 850) and is transported to the exhaust gas recovery unit 600. HCl is preferably separated from the exhaust gas 296 and discharged from the exhaust gas recovery unit 600 as HCl discharge 696. The recovered exhaust gas 698 is then fed back to the CVD unit or CVD reactor or SiC production reactor (particularly the SiC PVT source material production reactor 850), thereby reducing the amount of fresh feed gas mixture 198 required and reducing production costs.

[0296] Since product purity is very beneficial, Fig.16 In the apparatus described in, particular care is preferably taken to avoid introducing any contaminants (particularly trace metals and nitrogen or oxygen) into the feed gas or any intermediate and final product. Almost all equipment and piping are made of metal (particularly various steel alloys), but these equipment and piping are preferably maintained within a temperature range that minimizes the entry of metal particles into the feed gas and product. The feed gas and product are preferably further isolated from any moisture or air that may cause nitrogen and / or oxygen contamination. Although nitrogen can be used as a blanket gas and purge gas in storage tanks, pipelines and containers, it is preferably removed from any liquid raw materials using degassing equipment, and any nitrogen purge gas is preferably used with hydrogen to minimize the possibility of nitrogen contamination.

[0297] Fig.18An example of preparing three separate feed gases into a feed gas mixture 1160 in a feed gas unit 1000 is shown. First, preferably the industrial C-containing gas 1040 (preferably natural gas) needs to be purified of excess nitrogen to produce a C-containing gas 111 of sufficient purity for the manufacture of SiC (particularly UPSiC). Therefore, the industrial C-containing gas 1040 is preferably transported to a cryogenic distillation unit 105, where the low temperature condenses the industrial C-containing gas 1040 into a liquid state. Any contaminated nitrogen remains in its gaseous state and is discharged from the top of the cryogenic distillation unit 105 as a N gas effluent 1070. At the same time, the C-containing liquid 1130 is preferably discharged from the bottom of the cryogenic distillation device 105, preferably pumped to a C-containing liquid evaporator 1090, and evaporated therein into a C-containing gas 111. The mass flow rate of the C-containing gas 111 is adjusted by a mass flow meter 1120, and then the correct C-containing gas flow rate is preferably transported to a mixer or mixing device 854.

[0298] The purified hydrogen 102 is preferably also passed through a mass flow meter 1120 and is supplied to a mixer or mixing device 854 with the C-containing gas 111 in a correct ratio or a defined ratio. Finally, the purified Si-containing liquid 106 (preferably silicon tetrachloride (STC)) is supplied to a Si-containing liquid evaporator 1080 and evaporated into a Si-containing gas 110. The Si-containing gas 110 is preferably also supplied to a mass flow meter 1120 and is preferably delivered to a mixer 114 in a correct mass flow ratio or a defined mass flow ratio with the hydrogen 102 and / or the C-containing gas 111. The mixer 114 ensures that the three gases are evenly mixed and outputs a feed gas mixture 1160.

[0299] exist Fig.19 In another preferred embodiment of the present invention shown, a single C / Si-containing liquid 1180 is evaporated in a Si-containing liquid evaporator 1080 to become a C / Si-containing gas 1200. The C / Si-containing gas 1200 is preferably sent to a mass flow meter 1120, and its mass flow rate is preferably adjusted in the mass flow meter 1120 to form a desired or defined mass ratio with the hydrogen gas 102 which preferably also passes through the mass flow meter 1120. The two gases are preferably mixed into a uniform mixture in a mixer or mixing device 854 and discharged as a feed gas mixture 1160.

[0300] Fig. 20An exhaust treatment unit 500 of a CVD SiC (particularly UPSiC) device 850 in a preferred embodiment of the present invention is shown, wherein the exhaust gas 296 is treated and discharged, rather than being recycled. The exhaust gas 296 is conveyed from the CVD unit or CVD reactor or SiC production reactor (particularly SiC PVT source material production reactor) 850 to a filter unit 502 of the exhaust treatment unit 500, where any particles that may have formed in the gas are removed. The filtered exhaust gas 504 is then preferably conveyed to a scrubber unit 506, where it is preferably absorbed into the scrubber inlet fluid (particularly water 496). The scrubber outlet water 598, preferably containing any Si-containing compounds and HCl, is then discharged from the scrubber, particularly for treatment and disposal. The scrubbed exhaust gas 512 is then preferably conveyed to a flare unit 514, where it is combusted with a flare combustion gas 497 (preferably natural gas), and the resulting flare exhaust gas 596 is suitable for discharge.

[0301] Fig.21 An example of an exhaust gas recovery unit 600 of a CVD SiC (particularly UPSiC) device 850 in another preferred embodiment of the present invention is shown, in which the exhaust gas 296 is recovered instead of being treated and discharged. The exhaust gas 296 is conveyed from the CVD unit or CVD reactor or SiC production reactor (particularly SiC PVT source material production reactor 850) to a cold distillation unit 602, which preferably operates in a temperature range of -30°C to -196°C. In this temperature range, any Si-containing gas will condense and be discharged from the bottom of the distillation unit 602 as a Si-containing liquid mixture 604. This Si-containing liquid mixture 604 is periodically conveyed to a HMW distillation unit 606, which operates in a temperature range that evaporates the Si-containing liquid 604, while any heavy molecular weight compounds remain in liquid form and are discharged from the bottom of the HMW distillation unit 606 as a HMW liquid discharge 608.

[0302] At the same time, the Si-containing gas mixture 620 is discharged from the top of the HMW distillation unit 606 and passes through the Si detection unit 622 which determines the mass of Si. The Si detection unit 622 transmits this information to the central process control unit of the CVD SiC (particularly UPSiC) device 850, which then adjusts the mass flow meter 1120 on the Si-containing gas 110 pipeline to achieve the desired ratio of the total mass of Si from the Si-containing gas mixture 620 and the Si-containing gas 110 to the total mass of C from the H / C-containing gas mixture 616 and the C-containing gas 111. At the same time, the cold distillation gas 610 is discharged from the top of the cold distillation unit 602 and is sent to a cryogenic distillation unit, which is preferably operated in a temperature range of -140°C to -40°C. In this temperature range, the H / C-containing gas mixture 616 remains in a gaseous state, but HCl condenses and is removed from the bottom of the cryogenic distillation unit 612 as a liquid HCl discharge 696 for further processing and disposal.

[0303] The H / C containing gas mixture 616 passes through an H / C detection unit which determines the masses of H and C present. The H / C detection unit transmits this information to the central process control unit of the CVD SiC (particularly UPSiC) device 850, which then adjusts the mass flow meters 1120 on the hydrogen 102 line and the C containing gas 111 line to keep the mass ratios of H, C and Si within the desired range.

[0304] Fig. 22 An example of a system 999 according to the present invention is shown. The system 999 of the present invention comprises at least one SiC production reactor 850 and a PVT reactor 100, wherein the SiC production reactor 850 produces SiC source material for producing single crystal SiC in the PVT reactor 100.

[0305] according to Fig. 22 Additionally or alternatively, multiple SiC production reactors 850, 950 may be provided. Additionally or alternatively, multiple PVT reactors 100 may be provided. Furthermore, the SiC production reactor 850 may include an exhaust gas recovery unit 600. Alternatively, multiple SiC production reactors 850, 950 may be connected via an exhaust gas recovery unit 600. Thus, the exhaust gas of a first SiC production reactor 850 may be recovered and used as a source material for another SiC production reactor 950. Thus, at least some of the output of the exhaust gas recovery unit 600 (particularly Si, C and H2 components) may be used as a feed gas for the same or another SiC production reactor 850. Arrow 972 alternatively indicates that the output of the exhaust gas recovery unit 600 may be used for a CVD reactor 850 that discharges the exhaust gas.

[0306] Thus, due to the aforementioned system, the present invention provides a method for producing at least one SiC crystal. The method preferably comprises the following steps: setting up a CVD reactor 850 for producing a first type of SiC, introducing at least one source gas, in particular a first source gas, in particular SiCl3 (CH3), into a process chamber 856 to produce a source medium, wherein the source medium comprises Si and C, introducing at least one carrier gas into the process chamber 856, the carrier gas preferably comprising H, electrically exciting at least one SiC growth substrate 857 arranged in the process chamber 856 to heat the SiC growth substrate 857, wherein the surface of the SiC growth substrate 857 is heated to a temperature between 1400° C. and 1700° C., depositing the first type of SiC, in particular at a deposition rate greater than 200 μm / h, The SiC is deposited onto a SiC growth substrate 857, wherein the deposited SiC is preferably polycrystalline SiC, the deposited first type SiC is taken out from the CVD reactor 850, and the taken out SiC is preferably converted into first type fragmented SiC or into one or more first type solid SiC, a PVT reactor 100 is set up for producing a second type of SiC, and the first type fragmented SiC or one or more first type SiC solids are preferably added as source material 120 into a receiving space 118 of the PVT reactor 100, the first type SiC is sublimated inside the PVT reactor 100, and the sublimated SiC is deposited on the seed wafer 18 as the second type SiC.

[0307] The PVT reactor 100 preferably comprises a furnace unit 102, wherein the furnace unit 102 comprises a furnace shell 108 having an outer surface 242 and an inner surface 240; at least one crucible unit 106, wherein the crucible unit 106 is arranged in the furnace shell 108, wherein the crucible unit 106 comprises a crucible shell 110, wherein the crucible shell 110 has an outer surface 112 and an inner surface 114, wherein the inner surface 114 at least partially defines a crucible volume 116, wherein a receiving space 118 for receiving a source material 120 is arranged A furnace volume 104 is disposed or formed in the crucible volume 116, wherein a seed clamping unit 122 for fixing a specific seed wafer 18 is arranged in the crucible volume 116, wherein the seed clamping unit 122 fixes the seed wafer 18, wherein the furnace shell inner wall 240 and the crucible shell outer wall 112 define the furnace volume 104, at least one heating unit 124 for heating the source material 120, wherein a receiving space 118 for receiving the source material 120 is at least partially arranged above the heating unit 124 and below the seed clamping unit 122.

[0308] Fig.23 A comminution unit 699 is shown.

[0309] At the end of the deposition process, after the reactor has been purged and made inert, the bell jar can be lifted and the thick rod removed from the CVD reactor. This process is widely known as harvesting.

[0310] The collected rods must be processed into a shape suitable for PVT processing. This can be cut rod segments or broken pieces and blocks of various sizes.

[0311] Various methods are known for crushing hard and brittle solids, such as silicon carbide, into smaller fragments. The most common are mechanical methods. The SiC rods or their larger fragments are fed into a crusher, which is preferably a jaw crusher or a roller crusher. Adjustable machine parameters, such as gap distance, rotation speed or oscillation amplitude, determine the final particle size distribution. To avoid a large amount of fine particles and / or high contamination, multi-stage crushers can be used. The crushers are arranged in a series sequence, with the outlet of one crusher being connected directly or indirectly via a conveying device, such as a belt conveyor or a vibrating chute, to the feed inlet of a subsequent crusher with different machine parameters. Finally, the crushed fragments must be sorted to remove undersized material and return oversized material to the crushing process.

[0312] Other fragmentation methods are also possible. One known method is thermal cracking. A rod of hard, brittle material is heated and cooled at a high temperature gradient (e.g. by rapid immersion in a cold fluid).

[0313] Typically, mechanically driven screening machines are used to sort irregular solid material fragments into different size categories. An overview of the screening machines used is described in US2018169704. A more flexible optoelectronic method is disclosed in US2009 / 120848, which can extend the mechanical method of sorting solid material fragments.

[0314] If graphite is used as the starting material, the pulverization process digs out the starting substrate, because the interface between the starting substrate and the silicon carbide growth layer acts as a predetermined breaking point. This property can be used to easily remove the graphite substrate from the product by an annealing / heating treatment at a temperature of at least 900°C to 1400°C and carried out in air or an oxygen-rich gas mixture. The surface color changes from gray to blue-brown, which is due to the formation of a thin layer of silicon oxide (100nm-300nm) on the surface. This thin layer of silicon oxide can be easily removed by acid treatment.

[0315] Fig.24 An etching unit 799 is shown. The etching unit preferably comprises the following units:

[0316] Etching basin 800, water basin (water cascade) 801, drying unit 802, packaging unit 803. Reference numeral 810 indicates etched SiC, reference numeral 811 indicates acid-free SiC, reference numeral 812 indicates dried SiC, and reference numeral 813 indicates packaged SiC, in particular SiC packaged according to specifications.

[0317] The present invention therefore relates to a method for producing a preferably elongated SiC solid, in particular a SiC solid of the polytype 3C. The method according to the invention preferably comprises at least the following steps: introducing at least one first source gas into a process chamber, the first source gas comprising Si; introducing at least one second source gas into the process chamber, the second source gas comprising C; electrically exciting at least one separation element arranged in the process chamber to heat the separation element, setting a deposition rate of more than 200 μm / h, wherein a pressure of more than 1 bar is generated in the process chamber by the introduction of the first source gas and / or the second source gas, and wherein the surface of the deposition element is heated to a temperature between 1400° C. and 1700° C.

[0318] Fig.25a Schematically shows a cross-sectional view of a SiC solid 2605 for removing SiC growth substrates 2606, 2608. In this example, only one SiC growth substrate 2606 is grown in the center of the SiC solid, but multiple SiC growth substrates 2608 are grown at a certain distance from the center of the SiC solid.

[0319] Fig.25b Schematically illustrates a cross-sectional view of a SiC solid growing around a SiC growth substrate 2608 that is grown at a distance from the center of the SiC solid.

[0320] Fig.25c Schematically illustrates a cross-sectional view of a SiC solid growing around a SiC growth substrate 2608 that is grown at the center of the SiC solid.

[0321] Fig.26a The orientation of crystals 2414 in an inner portion 2600 of SiC carrier wafer 2322 is schematically shown.

[0322] In the length direction of a single microcrystal 2414 (see Fig.14Of all the crystallites 2414 of the inner portion 2600 extending more than 5 μm, in particular more than 10 μm, preferably more than 20 μm, particularly preferably more than 50 μm, more preferably up to 300 μm, most preferably up to 500 μm in a longitudinal direction (defined as “length direction” in the definition of “length direction” in the above description), more than 50%, preferably at least 60%, most preferably at least 70% of the crystallites 2414 are inclined at an angle 2614, an angle 2615, in particular at an angle less than + / - 22.5° to a middle direction 2604 in which the crystallites 2414 of the inner portion 2600 extend.

[0323] Figure 26b The orientation of crystals 2414 in the outer portion 2602 of the SiC carrier wafer 2322 is schematically shown.

[0324] In the length direction of a single microcrystal 2414 (see Fig.14 Of all the crystallites 2414 of the outer portion 2602 extending more than 5 μm, in particular more than 10 μm, preferably more than 20 μm, particularly preferably more than 50 μm, more preferably up to 300 μm, most preferably up to 500 μm in the length direction (defined as “length direction” in the above description), more than 25%, preferably at least 50%, most preferably up to 75% of the crystallites 2414 are inclined to the extension middle direction 2604 of the inner portion 2600 at an angle 2614, an angle 2615, in particular at an angle greater than + / - 22.5°.

[0325] Fig.26a and Figure 26b An example of a common embodiment is preferably shown, wherein two figures are provided for explanation purposes only. Fig.26a / Figure 26b The SiC carrier wafer 2322 is beneficial because it includes crystallites having a length greater than 5 μm, particularly greater than 10 μm, preferably greater than 20 μm, particularly preferably greater than 50 μm, more preferably up to 300 μm, and most preferably up to 500 μm, so that tension inside the SiC carrier wafer 2322 can be compensated, thereby reducing bending and warping, and reducing cracks. Fig.26a / Figure 26b The embodiment is further beneficial because a SiC growth substrate 2608 grown at a distance from the center of the SiC solid is used. Since more than one SiC growth substrate 2608 can be grown at a distance from the center of the SiC solid and can be removed from the SiC, the cost of such SiC growth substrates 2608 is low compared to the cost of a SiC growth substrate 2606 grown at the center of the SiC solid.

[0326] Fig. 27Another example of a SiC solid grown according to the present invention is shown and used to remove a SiC growth substrate 857 and / or SiC carrier wafer 2322 therefrom. The dashed line represents the surface of the SiC growth substrate 857 prior to SiC deposition. The surface of the SiC growth substrate 857 is preferably etched.

[0327] The etching of the surface of the SiC growth substrate 857 is preferably performed before the SiC growth substrate 857 is placed in the CVD reactor 850 (particularly any CVD reactor 850 described herein, particularly according to Figure 1 , Figure 2 , Figure 3 4) and before the step of growing SiC solid 211 by depositing SiC on the deposition surface of SiC growth substrate 857 in CVD reactor 850. The etching step after placing SiC growth substrate 857 in CVD reactor 850 is preferably performed by gas etching (especially hydrogen etching) and / or plasma etching (especially hydrogen plasma etching). The same applies to Figure 25a-Figure 26b .

[0328] Fig. 27 It is further shown that in the length direction of a single microcrystal 2414 (see Fig.14 Of all the crystallites 2414 of the outer portion 2602 extending more than 5 μm, in particular more than 10 μm, preferably more than 20 μm, particularly preferably more than 50 μm, more preferably up to 300 μm, most preferably up to 500 μm in the length direction (defined as “length direction” in the above description), more than 25%, preferably at least 50%, most preferably up to 75% of the crystallites 2414 are inclined to the extension middle direction 2604 of the inner portion 2600 at an angle 2614, an angle 2615, in particular at an angle greater than + / - 22.5°.

[0329] Therefore, the present invention preferably provides a useful SiC carrier wafer 2322, in particular a crack-free SiC carrier wafer 2322. The diameter of the SiC carrier wafer 2322 is preferably at least 7.5 cm. The height of the SiC carrier wafer 2322 is preferably between 200 μm and 500 μm. The SiC carrier wafer 2322 preferably includes at least one or exactly one inner portion 2600, in particular a central inner portion 2600, wherein the SiC carrier wafer 2322 preferably includes an outer portion 2602, wherein the outer portion 2602 surrounds the inner portion 2600, wherein the inner portion 2600 consists of a portion of a SiC growth substrate 857, wherein the inner portion 2600 is mainly formed by a 3C crystal structure, and wherein the outer portion 2602 is mainly formed by a 3C crystal structure and includes microcrystals 2414 extending along the length direction of a single microcrystal 2414 by more than 5μm, in particular more than 10μm and preferably more than 20μm and particularly preferably more than 50μm and most preferably up to 500μm or up to 300μm, wherein the curvature 2322 of the SiC carrier wafer is preferably lower than 50μm, in particular lower than 20μm, and / or wherein the warpage of the SiC carrier wafer 2322 is preferably lower than 50μm, in particular lower than 20μm. The crystal structure of the inner part and the crystal structure of the outer part, in particular the 3C crystal structure of the inner part 2600 and the 3C crystal structure of the outer part 2602 are preferably doped, in particular doped with nitrogen, in particular doped with more than 2000 ppba of nitrogen, and have a resistivity less than 0.03 Ohm cm, preferably less than 0.02 Ohm cm, and most preferably less than 0.01 Ohm cm.

[0330] List of reference numerals

[0331] 18 seed wafers

[0332] 100 Furnace Installation

[0333] 102 Furnace Unit

[0334] 104 Furnace volume

[0335] 106 Crucible Unit

[0336] 107 Filter cover or crucible cover

[0337] 108 Furnace shell

[0338] 110 Crucible Shell

[0339] 112 Crucible shell outer surface

[0340] 114 Inner surface of crucible shell

[0341] 116 Crucible volume

[0342] 117 bottom surface of receiving space

[0343] 118 Receiving Space

[0344] 120 Source Material

[0345] 122 Seed clamping unit

[0346] 123 Diameter of the seed holding unit

[0347] 124 Heating unit

[0348] 202 Upper shell

[0349] 203 Transverse member

[0350] 206a First electrode

[0351] 206b Second electrode

[0352] 208 Chuck

[0353] 209 Temperature measurement path

[0354] 211SiC shell / SiC solid

[0355] 213 Viewing mirror

[0356] 240 Inner surface of furnace shell

[0357] 242 outer surface of furnace shell

[0358] 278 Source Material Carrier Plate

[0359] 280 Gas guide clearance

[0360] 282 Through Holes

[0361] 296 Exhaust

[0362] 298UPSIC Rod

[0363] 300 crushing unit

[0364] 370 Upper surface of the source material carrier plate

[0365] 372 Lower surface of source material carrier plate

[0366] 398UPSiC particles

[0367] 400 Acid Etching Unit

[0368] 496 Scrubber Inlet Water

[0369] 497 Flare Gas

[0370] 498UPSiC Etching Particles

[0371] 500 Exhaust Treatment Unit

[0372] 502 Exhaust Filter Unit

[0373] 504 Filtered exhaust

[0374] 506 Scrubber Unit

[0375] 512 Exhaust after washing

[0376] 514 Flare Unit

[0377] 596 Flare exhaust

[0378] 598 Scrubber outlet water

[0379] 600 Exhaust Recovery Unit

[0380] 602 Cold distillation unit or separation unit

[0381] 604 Si-containing liquid mixture

[0382] 606 HMW distillation unit

[0383] 608 HMW liquid discharge

[0384] 610 Cold distilled gas

[0385] 612 Cryogenic distillation unit or other separation device

[0386] 616 H / C gas mixture

[0387] 618H / C detector unit or C mass flux measurement unit

[0388] 620 Si-containing mixed gas

[0389] 622Si detector unit or Si mass flux measurement unit

[0390] 624 first storage and / or conduction element

[0391] 626 Second storage and / or conduction element

[0392] 628 Storage and / or conducting elements for chlorosilane mixtures

[0393] 630HCl storage and / or conduction element

[0394] 632H2 and C storage and / or conduction elements

[0395] 634 First Compressor

[0396] 636 Another compressor

[0397] 696 HCl Liquid Discharge

[0398] 698 Recycled Exhaust

[0399] 699 Crushing Unit

[0400] 700 Pre-crusher

[0401] 701 Crusher

[0402] 702 Screening Machine (screen removal)

[0403] 703 Screening Machine (Sieve Oversize Removal)

[0404] 704 annealing furnace

[0405] 710 Pre-crushed SiC

[0406] 711 Crushed SiC (all particle sizes)

[0407] 712 Crushed SiC, excluding small particles (1mm to 30mm)

[0408] 713 Small size SiC (0mm to 1mm)

[0409] 714 Large size SiC, return to crush (greater than 12mm)

[0410] 715SiC products (1mm to 12mm)

[0411] 716 Annealed SiC (without graphite; 1mm to 12mm)

[0412] 799 Etching Unit

[0413] 800 Etching Basin

[0414] 801 Basin (Water Cascade)

[0415] 802 Drying Unit

[0416] 803 Packaging Unit

[0417] 810 Etched SiC

[0418] 811 Acid-free SiC

[0419] 812 Dry SiC

[0420] 813SiC packaged according to specifications

[0421] 850 Manufacturing device or CVD unit or CVD reactor or SiC production reactor, especially SiC PVT source material production reactor

[0422] 851 first feeding device or first feeding medium source

[0423] 852 second feeding device or second feeding medium source

[0424] 853 third feeding device or third feeding medium source or carrier gas feeding medium source

[0425] 854 Mixing device

[0426] 855 Evaporator unit

[0427] 856 Craft Room

[0428] 857 SiC growth substrate

[0429] 858 Temperature measuring device or temperature control unit

[0430] 859 Energy, especially power supply

[0431] 859a First power connection

[0432] 859b Second power supply connection

[0433] 860 Pressure holding device or pressure control unit

[0434] 861Outer surface of SiC growth substrate or SiC growth surface

[0435] 862 Base Plate

[0436] 864 Bell Jar

[0437] 864a Side wall section

[0438] 864b Top wall part

[0439] 865 Metal surface

[0440] 866 Gas Inlet Unit

[0441] 867 Reflective coating

[0442] 868 Cooling element

[0443] 870 Active Cooling Element

[0444] 873 Fluid Transfer Unit

[0445] 892 Cooling Fluid Temperature Sensor

[0446] 966 Reaction Space

[0447] 972 Arrow

[0448] 999 System

[0449] 1000 Feed Gas Unit

[0450] 1040 Industrial C-containing gas

[0451] 1070N gas discharge

[0452] 1080 Si-containing liquid evaporator

[0453] 1090 C liquid evaporator

[0454] 1120 Mass Flow Meter

[0455] 1130 Liquid containing C

[0456] 1160 Feed gas mixture

[0457] 1180 C / Si containing liquid

[0458] 1200 containing C / Si gas

[0459] 2040 Lower shell

[0460] 2120 Exhaust

[0461] 2140 Feed gas inlet

[0462] 2200 Main Body

[0463] 2299 CVD SiC with physical structure

[0464] 2300SiC parts / crack-free SiC parts

[0465] 2301 SiC parts that may have cracks

[0466] 2302 First Plane

[0467] 2304 Second Plane

[0468] 2305 Crack

[0469] 2306 First Direction

[0470] 2308 Second Direction

[0471] 2314 Crack-free sub-components / predefined components / wafers

[0472] 2316 Wafer surface / processed surface

[0473] 2317 First substrate / single crystal SiC crystal

[0474] 2318 Single Crystal SiC Wafer / Thin Substrate

[0475] 2319 epitaxial layer

[0476] 2320 Multi-substrate wafer / composite substrate

[0477] 2322 Second substrate / carrier wafer / polycrystalline SiC structure

[0478] 2324 Grain Orientation

[0479] 2326 A quarter of an angle

[0480] 2328 Rough sawing

[0481] 2330 Wafer Slicing

[0482] 2332 Wafer grinding

[0483] 2334Removing a thin layer of single crystal SiC

[0484] 2336 Wafer Polishing

[0485] 2338 Wafer Bonding

[0486] 2400 Top surface of the first substrate

[0487] 2402 bottom surface of the second substrate

[0488] 2404 Connection surface of first substrate

[0489] 2406 top surface of the second substrate

[0490] 2408 Bottom surface of second substrate

[0491] 2410 connection surface of the second substrate

[0492] 2412 ribbon or line or straight line elements

[0493] 2414 Large Crystallite

[0494] 2415 Small Microcrystal

[0495] 2416 Cutting plane

[0496] 2418 Ion implantation layer

[0497] 2420 parts

[0498] 2500 Prior art carrier wafers

[0499] 2502 Growth substrate for epitaxial growth of carrier wafers of the prior art

[0500] 2504 Growth direction of carrier wafer in prior art

[0501] 2506 Prior Art Carrier Wafer for Large Microcrystals

[0502] 2508 First main surface

[0503] 2510 Second main surface

[0504] 2600 Internal part

[0505] 2602 External part

[0506] 2604 Extend the intermediate direction (in the image plane)

[0507] 2605SiC solid, used to remove SiC growth substrate

[0508] 2606SiC growth substrate, grown in the center of SiC solid 2608SiC growth substrate, grown at a certain distance from the center of SiC solid

[0509] 2610SiC solid, preferably used to produce SiC carrier wafers

[0510] 2612 The angle between the surface 2614 of the SiC growth substrate 2606 and the middle direction of the microcrystal extension of the inner part is preferably less than +22.5° 2615 The angle between the surface 2614 of the SiC growth substrate 2606 and the middle direction of the microcrystal extension of the inner part is preferably less than -22.5° 2616 The angle between the surface 2614 of the SiC growth substrate 2606 and the middle direction of the microcrystal extension of the inner part is preferably greater than +22.5° 2618 The angle between the surface 2614 of the SiC growth substrate 2606 and the middle direction of the microcrystal extension of the inner part is preferably greater than -22.5° 2620 The interface between the inner part and the outer part

[0511] H Height direction

[0512] L is the length direction of the crystallite

[0513] R Radial direction of the polycrystalline structure

Claims

1. A SiC carrier wafer (2322), in particular a crack-free SiC carrier wafer (2322), in, The diameter of the SiC carrier wafer (2322) is at least 7.5 cm, The height of the SiC carrier wafer (2322) is between 200 μm and 500 μm. wherein the SiC carrier wafer (2322) comprises at least one or exactly one inner portion (2600), in particular a central inner portion (2600), and wherein the SiC carrier wafer (2322) includes an outer portion (2602), wherein the outer portion (2602) surrounds the inner portion (2600), wherein the inner portion (2600) is composed of a portion of a SiC growth substrate (857), wherein the inner portion (2600) is formed of a crystal structure, wherein the crystal structure of the inner portion (2600) is mainly formed of a 3C crystal structure, and wherein the outer portion (2602) is formed of a crystal structure, wherein the crystal structure of the outer portion (2602) is mainly formed of a 3C crystal structure and comprises crystallites (2414) extending in a length direction of a single crystallite (2414) for more than 5 μm, in particular for more than 10 μm, preferably for more than 20 μm, particularly preferably for more than 50 μm, most preferably up to 500 μm or up to 300 μm, wherein the curvature of the SiC carrier wafer (2322) is less than 50 μm, in particular less than 20 μm, and / or wherein the warpage of the SiC carrier wafer (2322) is less than 50 μm, in particular less than 20 μm, Wherein, the crystal structure of the inner part (2600) and the crystal structure of the outer part (2602), especially the 3C crystal structure of the inner part (2600) and the 3C crystal structure of the outer part (2602), are doped with nitrogen, especially doped with nitrogen exceeding 2000ppba, and have a resistivity less than 0.03Ohm cm, preferably less than 0.02Ohm cm, and most preferably less than 0.01Ohmcm.

2. The SiC carrier wafer (2322) according to claim 1, It is characterized in that Every 1mm of the outer part (2602) 3 There are more than 5, particularly more than 10, more preferably more than 100, most preferably more than 500, or up to 10,000 crystallites (2414), and these crystallites extend in the length direction of a single crystallite (2414) for more than 5 μm, particularly more than 10 μm, preferably more than 20 μm, particularly preferably more than 50 μm, more preferably up to 300 μm, and most preferably up to 500 μm.

3. The SiC carrier wafer (2322) according to claim 1 or 2, It is characterized in that The inner portion (2600) includes crystallites (2414) extending along the length direction of a single crystallite (2414) for more than 5 μm, particularly more than 10 μm, preferably more than 20 μm, particularly preferably more than 50 μm, more preferably up to 300 μm, and most preferably up to 500 μm.

4. The SiC carrier wafer (2322) according to claim 3, It is characterized in that Every 1mm in the inner part (2600) 3 There are more than 5, particularly more than 10, more preferably more than 100, most preferably more than 500, or up to 10,000 crystallites (2414), and these crystallites extend in the length direction of a single crystallite (2414) for more than 5 μm, particularly more than 10 μm, preferably more than 20 μm, particularly preferably more than 50 μm, more preferably up to 300 μm, and most preferably up to 500 μm.

5. The SiC carrier wafer (2322) according to claim 3 or 4, It is characterized in that Of all the crystallites (2414) in the inner portion (2600) extending more than 5 μm, particularly more than 10 μm, preferably more than 20 μm, particularly preferably more than 50 μm, more preferably up to 300 μm, and most preferably up to 500 μm in the length direction of a single crystallite (2414), more than 50%, preferably at least 60%, and most preferably at least 70% of the crystallites (2414) are inclined at an angle less than + / - 22.5° to the extension middle direction (2604) of the crystallite (2414) of the inner portion (2600).

6. The SiC carrier wafer (2322) according to any one of claims 1 to 5, It is characterized in that Of all the crystallites (2414) in the outer portion (2602) extending more than 5 μm, particularly more than 10 μm, preferably more than 20 μm, particularly preferably more than 50 μm, more preferably up to 300 μm, and most preferably up to 500 μm in the length direction of a single crystallite (2414), more than 25%, preferably at least 50%, and most preferably up to 75% of the crystallites (2414) are inclined at an angle greater than + / - 22.5° to the extension middle direction (2604) of the inner portion (2600).

7. The SiC carrier wafer (2322) according to any one of claims 1 to 6, It is characterized in that The chemical composition of the interface (2620) between the outer portion (2602) and the inner portion (2600) is the same as the chemical composition of a portion in the outer portion (2602), which is located between the interface (2620) between the outer portion (2602) and the inner portion (2600) and the surrounding surface of the outer portion (2602), and / or the chemical composition of the interface (2620) between the outer portion (2602) and the inner portion (2600) is the same as the chemical composition of a portion in the inner portion (2600), which is located between the interface (2602) between the outer portion (2602) and the inner portion and the center of the inner portion (2600).

8. The SiC carrier wafer (2322) according to claim 7, It is characterized in that The inner portion (2600) has a cross-sectional area orthogonal to the circumferential direction, the cross-sectional area being at least 0.5 cm 2 , preferably at least 2 cm 2 , most preferably at least 5 cm 2 or up to 50cm 2 .

9. The SiC carrier wafer (2322) according to claim 8, It is characterized in that The cross-sectional area of ​​the SiC growth substrate (857) has a circular or rectangular shape, or The cross-sectional area of ​​the SiC growth substrate (857) is in the shape of a ribbon. The SiC growth substrate (857) preferably has two large surface portions connected by a small surface portion, wherein the surface size of the large surface portion is larger than the surface size of the small surface portion, in particular the surface size of the large surface portion is more than 5 times or more than 50 times or up to 1000 times the surface size of the small surface portion.

10. The SiC carrier wafer (2322) according to any one of the preceding claims, It is characterized in that The SiC carrier wafer (2322) comprises a treated surface, wherein the treated surface is produced by mechanical separation, in particular by cleaving or sawing, of a crack-free SiC component (2300) preferably having a thickness of at least 1 cm.

11. The SiC carrier wafer (2322) according to claim 10, It is characterized in that The treated surface is a mechanically structured surface, wherein the mechanically structured surface is ground and / or finely ground and / or polished, in particular, the surface roughness R A Reduced to below 5 nm, particularly below 3 nm, most preferably below or equal to 1 nm.

12. A composite substrate (2320), At least comprising a SiC carrier wafer according to any one of claims 10 or 11, And single crystal SiC wafer (2318), in, A single crystal SiC wafer (2318) is bonded to the processed surface of a SiC carrier wafer (2322).

13. A method for producing at least one SiC carrier wafer, in particular a crack-free SiC carrier wafer, comprising at least the following steps: Setting up a CVD reactor (850), At least one SiC growth substrate (857) is arranged in a CVD reactor (850), Wherein, the SiC growth substrate (857) is formed: Growing a SiC solid (211) to a diameter of at least 7.5 cm by depositing SiC on the deposition surface (861) in a CVD reactor (850) around the deposition surface (861) of the SiC growth substrate (857) in a circumferential direction of the SiC growth substrate (857), or The SiC solid (211) is grown to a cross-sectional area orthogonal to the length direction of the SiC growth substrate (857) of at least 44.17 cm 2 , removing at least one SiC component from the SiC solid (211) by mechanical means, in particular by sawing, and At least one SiC carrier wafer (2322) is removed from the SiC component (2300) mechanically, in particular by sawing.

14. The method according to claim 13, It is characterized in that The step of growing a SiC solid (211) comprises setting a deposition rate, in particular a vertical deposition rate, greater than 200 μm / h, in particular greater than 250 μm / h, preferably greater than 300 μm / h, more preferably greater than 400 μm / h, most preferably greater than 500 μm / h or up to 2000 μm / h.

15. The method according to claim 13 or 14, Features The step of analyzing the SiC solid (211) to determine the crack-free portion of the SiC solid (211), wherein the step of analyzing the SiC solid (211) is performed before the step of mechanically removing at least one SiC component from the SiC solid, in particular by sawing.

16. The method according to claim 15, It is characterized in that At least one SiC component is removed from the crack-free portion of the SiC solid (211), or the crack-free portion of the SiC solid (211) is removed as at least one SiC component.

17. The method according to claim 15 or 16, It is characterized in that The step of analyzing the SiC solid (211) to determine the crack-free portion of the SiC solid (211) is performed by optical inspection, in particular by caliper or threshold detection.

18. The method according to claims 13 to 17, Features Step of analyzing a SiC component or a SiC carrier wafer to determine defects, in particular cracks.

19. The method according to claim 18, It is characterized in that The step of analyzing the SiC component or the SiC carrier wafer to determine defects is performed by a bend test, in particular by a 2-point bend test, a 3-point bend test or a 4-point bend test, an eddy current test and / or an optical analysis method, in particular a caliper test or a threshold test or a transmission test.

20. The method according to claims 13 to 19, It is characterized in that The step of heating the SiC growth substrate (857) by passing current through the SiC growth substrate (857) by conducting the current from the first power connection to the second power connection or from the second power connection to the first power connection.

21. The method according to claim 20, It is characterized in that The SiC growth substrate (857), in particular the growth surface of the deposited SiC, is heated to a temperature above 1400°C.

22. The method according to claim 21, It is characterized in that The growth surface of the deposited SiC is heated to a temperature below 1700°C, and the center of the SiC growth substrate (857) is heated to a temperature above 1400°C.

23. The method according to claim 20, 21 or 22, It is characterized in that The current is alternating current.

24. The method according to claim 23, 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.

25. The method according to claims 13 to 24, It is characterized in that The minimum thickness of the deposited SiC is at least 1 cm, and wherein at least one SiC component (2300) is formed between a first plane (2302) and a second plane (2304), and wherein the first plane (2302) is orthogonal to the body length (ML), and wherein the second plane (2304) is orthogonal to the body length (ML), wherein the distance (D) between the first plane (2302) and the second plane (2304) is at least 1%, preferably at least 2%, and more preferably at least 5% of the length (ML) of the body, and Among them, the deposited SiC is polycrystalline SiC, Therein, the deposited SiC forms a volume portion with a different crystal structure, Among them, 3C crystal structure is mainly formed in terms of mass and / or volume, wherein the volume and / or mass of SiC formed with a 3C crystal structure accounts for more than 50% of the volume and / or mass of the deposited SiC, Among them, the SiC carrier wafer has no cracks.

26. The method according to claim 25, It is characterized in that The at least one SiC component (2300) has a cross-sectional dimension of at least 4 cm 2 , preferably at least 8 cm 2 , more preferably at least 12 cm 2 , and a thickness of at least 0.1 cm, preferably at least 1 cm, more preferably at least 2 cm, and / or Wherein, the volume (V) of the at least one SiC component (2300) is greater than 2 cm 3 , preferably greater than 4cm 3 , most preferably greater than 8cm 3 , wherein at least one of the SiC components (2300) is crack-free.

27. The method according to any one of claims 13 to 26, in, The SiC growth substrate (857) comprises: Main 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), wherein the first power connection (859a) is configured to conduct electricity into the body (2200) to heat the body (2200), and wherein the second power connection (859b) is configured to conduct electricity conducted into the body (2200) through the first power connection (859a) out of the body (2200).

28. The method according to any one of claims 13 to 27, It is characterized in that Before placing the SiC growth substrate (857) in the CVD reactor, a step of etching the surface of the SiC growth substrate (857) is performed, wherein the etching step is performed using hydrofluoric acid etching, and / or After the SiC growth substrate (857) is disposed in a CVD reactor and before the step of growing a SiC solid (211) by depositing SiC on the deposition surface of the SiC growth substrate (857) in the CVD reactor (850), a step of etching the surface of the SiC growth substrate (857) is performed.

29. The method according to claim 28, It is characterized in that The etching step after the SiC growth substrate (857) is arranged in the CVD reactor is performed by gas etching, especially hydrogen etching and / or by plasma etching, especially hydrogen plasma etching.

30. The method according to any one of claims 13 to 29, It is characterized in that The step of growing a SiC solid (211) comprises achieving crystallites (2414) having a length greater than 5 μm, in particular greater than 10 μm, preferably greater than 20 μm, particularly preferably greater than 50 μm, most preferably up to 500 μm or up to 300 μm.

31. The method according to claim 30, It is characterized in that Every 1mm 3 More than 5 microcrystals (2414), in particular more than 10 microcrystals (2414), more preferably more than 100, most preferably more than 500 microcrystals (2414), or up to 10,000 microcrystals (2414) are grown, and these microcrystals extend in the length direction of a single microcrystal (2414) by more than 5 μm, in particular more than 10 μm, preferably more than 20 μm, particularly preferably more than 50 μm, more preferably up to 300 μm, and most preferably up to 500 μm.

32. The method according to any one of claims 13 to 31, It is characterized in that The SiC growth substrate (857) includes crystallites (2414) extending along the length direction of a single crystallite (2414) for more than 5 μm, in particular more than 10 μm, preferably more than 20 μm, particularly preferably more than 50 μm, more preferably up to 300 μm, and most preferably up to 500 μm.

33. The method according to claim 32, It is characterized in that Every 1mm of SiC growth substrate (857) 3 There are more than 5, especially more than 10, more preferably more than 100, most preferably more than 500, or up to 10,000 microcrystals (2414), and these microcrystals extend in the length direction of a single microcrystal (2414) for more than 5 μm, especially more than 10 μm, preferably more than 20 μm, particularly preferably more than 50 μm, more preferably up to 300 μm, and most preferably up to 500 μm.

34. The method according to any one of claims 32 to 33, It is characterized in that Of all the crystallites (2414) of the SiC growth substrate (857) extending in the length direction of a single crystallite (2414) for more than 5 μm, in particular more than 10 μm, preferably more than 20 μm, particularly preferably more than 50 μm, more preferably up to 300 μm, and most preferably up to 500 μm, more than 50%, preferably at least 60%, and most preferably at least 70% of the crystallites (2414) are inclined at an angle less than + / - 22.5° to the extension middle direction (2604) of the SiC growth substrate (857).

35. The method according to claim 34, It is characterized in that Of all grown crystallites (2414) extending in the length direction of a single crystallite (2414) over a length exceeding 5 μm, in particular exceeding 10 μm, preferably exceeding 20 μm, particularly preferably exceeding 50 μm, more preferably up to 300 μm, and most preferably up to 500 μm, over 25%, preferably at least 50%, and most preferably up to 75% of the crystallites (2414) are inclined at an angle greater than + / - 22.5° to the extension middle direction (2604) of the inner portion (2600).

36. A method according to any one of claims 13 or 27 to 35, It is characterized in that SiC is deposited until the minimum thickness of the SiC solid (211) is at least 1 cm, and wherein, due to the deposition of SiC, at least one SiC component (2300) is formed between the first plane (2302) and the second plane (2304), and wherein the first plane (2302) is orthogonal to the body length (ML), and wherein the second plane (2304) is orthogonal to the body length (ML), wherein the distance (D) between the first plane (2302) and the second plane (2304) is at least 1%, preferably at least 2%, and more preferably at least 5% of the length (ML) of the body, and Among them, the deposited SiC is polycrystalline SiC, Among them, SiC forms a volume part with a different crystal structure due to deposition, Among them, since the deposition of SiC mainly forms a 3C crystal structure in terms of mass and / or volume, wherein the volume and / or mass of SiC formed in a 3C crystal structure due to SiC deposition accounts for more than 50% of the volume and / or mass of the deposited SiC, Among them, the SiC carrier wafer has no cracks.

37. The method according to claim 36, It is characterized in that At least one SiC component (2300) has a cross-sectional dimension of at least 4 cm 2 , preferably at least 8 cm 2 , more preferably at least 12 cm 2 , and a thickness of at least 0.1 cm, preferably at least 1 cm, more preferably at least 2 cm, and / or Wherein, at least one SiC component (2300) has a volume (V) greater than 2 cm 3 , preferably greater than 4cm 3 , most preferably greater than 8cm 3 , wherein at least one SiC component (2300) is crack-free.

38. A method for producing at least one large SiC component, in particular an ingot or a rod, comprising at least the following steps: A CVD reactor (850) is provided, wherein the CVD reactor (850) At least one SiC growth substrate (857) is arranged in a CVD reactor (850), Wherein, the SiC growth substrate (857) is formed: growing a polycrystalline SiC solid (211) by depositing SiC on the deposition surface (861) in a CVD reactor (850) around a deposition surface (861) of the SiC growth substrate (857) in a circumferential direction of the SiC growth substrate (857), wherein the deposition is carried out until the SiC solid (211) grows to a diameter of at least 1 cm, or preferably at least 5 cm, or particularly preferably at least 10 cm, or most preferably at least 20 cm or up to 100 cm, wherein the deposition is performed until the SiC solid (211) grows to a cross-sectional size of at least 40 cm 2 , especially at least 50cm 2 or at least 200cm 2 or at least 500cm 2 and / or up to 1000cm 2 or preferably up to 2000cm 2 , preferably up to 8000cm 2 , the cross section is orthogonal to the current conduction path within the SiC growth substrate (857), The SiC solid (211) is analyzed to determine that the cross-sectional dimension within the SiC solid (211) is at least 4 cm 2 the position of at least one crack-free SiC component (2300), At least one crack-free SiC component (2300) is removed from the SiC solid (211).

39. The method according to claim 38, It is characterized in that The step of analyzing the SiC solid (211) to determine the crack-free portion of the SiC solid (211) is performed by optical inspection, in particular by caliper or threshold detection.

40. The method according to claim 39, It is characterized in that The SiC solid (211) is analyzed by determining defects inside the SiC component (2300), in particular determining the location and / or orientation of cracks to determine that the cross-sectional dimensions inside the SiC solid (211) are at least 4 cm 2 The step of positioning at least one crack-free SiC component (2300).

41. The method according to claim 40, It is characterized in that The step of analyzing the SiC component to determine the location and / or orientation of defects is performed by a bend test, in particular a 2-point bend test, a 3-point bend test or a 4-point bend test, an eddy current test and / or an optical analysis method, in particular a caliper test or a threshold test.

42. The method according to claims 38 to 41, It is characterized in that The step of heating the SiC growth substrate (857) by passing current through the SiC growth substrate (857) by conducting the current from the first power connection to the second power connection or from the second power connection to the first power connection.

43. The method according to claim 42, It is characterized in that The SiC growth substrate (857), in particular the growth surface of the deposited SiC, is heated to a temperature above 1400°C.

44. The method according to claim 43, It is characterized in that The growth surface of the deposited SiC is heated to a temperature below 1700°C, and the center of the SiC growth substrate (857) is heated to a temperature above 1400°C.

45. The method according to claim 42, 43 or 44, It is characterized in that The current is alternating current.

46. ​​The method according to claim 45, 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.

47. The method according to claims 38 to 46, It is characterized in that The step of growing the SiC component comprises setting a deposition rate, in particular a vertical deposition rate, greater than 200 μm / h, in particular greater than 250 μm / h, preferably greater than 300 μm / h, more preferably greater than 400 μm / h, most preferably greater than 500 μm / h or up to 2000 μm / h.

48. The method according to any one of claims 38 to 47, in, The SiC growth substrate (857) comprises: Main 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), wherein the first power connection (859a) is configured to conduct electricity into the body (2200) to heat the body (2200), and wherein the second power connection (859b) is configured to conduct electricity conducted into the body (2200) through the first power connection (859a) out of the body (2200).

49. The method according to any one of claims 38 to 48, It is characterized in that Before placing the SiC growth substrate (857) in the CVD reactor, a step of etching the surface of the SiC growth substrate (857) is performed, wherein the etching step is performed using hydrofluoric acid etching, and / or After the SiC growth substrate (857) is disposed in a CVD reactor and before the step of growing a SiC solid (211) by depositing SiC on the deposition surface of the SiC growth substrate (857) in the CVD reactor (850), a step of etching the surface of the SiC growth substrate (857) is performed.

50. The method according to claim 49, It is characterized in that The etching step is performed by gas etching, in particular hydrogen etching, and / or by plasma etching, in particular hydrogen plasma etching.

51. The method according to any one of claims 38 to 50, It is characterized in that The step of growing a SiC solid (211) comprises achieving crystallites (2414) having a length greater than 5 μm, in particular greater than 10 μm, preferably greater than 20 μm, particularly preferably greater than 50 μm, most preferably up to 500 μm or up to 300 μm.

52. The method according to claim 51, It is characterized in that Every 1mm 3 More than 5 microcrystals (2414), in particular more than 10 microcrystals (2414), more preferably more than 100, most preferably more than 500 microcrystals (2414), or up to 10,000 microcrystals (2414) are grown, and these microcrystals extend in the length direction of a single microcrystal (2414) by more than 5 μm, in particular more than 10 μm, preferably more than 20 μm, particularly preferably more than 50 μm, more preferably up to 300 μm, and most preferably up to 500 μm.

53. The method according to any one of claims 38 to 52, It is characterized in that The SiC growth substrate (857) includes crystallites (2414) extending along the length direction of a single crystallite (2414) for more than 5 μm, in particular more than 10 μm, preferably more than 20 μm, particularly preferably more than 50 μm, more preferably up to 300 μm, and most preferably up to 500 μm.

54. The method according to claim 53, It is characterized in that Every 1mm of SiC growth substrate (857) 3 There are more than 5 microcrystals (2414), especially more than 10 microcrystals (2414), more preferably more than 100, most preferably more than 500 microcrystals (2414), or up to 10,000 microcrystals (2414), and these microcrystals extend in the length direction of a single microcrystal (2414) for more than 5 μm, especially more than 10 μm, preferably more than 20 μm, particularly preferably more than 50 μm, more preferably up to 300 μm, and most preferably up to 500 μm.

55. The method according to any one of claims 53 to 54, It is characterized in that Of all the crystallites (2414) of the SiC growth substrate (857) extending in the length direction of a single crystallite (2414) for more than 5 μm, in particular more than 10 μm, preferably more than 20 μm, particularly preferably more than 50 μm, more preferably up to 300 μm, and most preferably up to 500 μm, more than 50%, preferably at least 60%, and most preferably at least 70% of the crystallites (2414) are inclined at an angle less than + / - 22.5° to the extension middle direction (2604) of the SiC growth substrate (857).

56. The method according to claim 55, It is characterized in that Of all grown crystallites (2414) extending in the length direction of a single crystallite (2414) over a length exceeding 5 μm, in particular exceeding 10 μm, preferably exceeding 20 μm, particularly preferably exceeding 50 μm, more preferably up to 300 μm, and most preferably up to 500 μm, over 25%, preferably at least 50%, and most preferably up to 75% of the crystallites (2414) are inclined at an angle greater than + / - 22.5° to the extension middle direction (2604) of the inner portion (2600).

57. The method according to any one of claims 38 to 56, It is characterized in that The SiC solid (211) is grown to a diameter of at least 7.5 cm.

58. The method according to any one of claims 38 to 57, It is characterized in that The SiC is doped with nitrogen during the growth step, in particular with nitrogen greater than 2000 ppba and / or less than 10 18 Nitrogen atoms / cm 3 .

59. The method according to any one of claims 38 to 58, It is characterized in that SiC solid (211) mainly grows with 3C crystal structure.

60. A method of producing a plurality of crack-free workpieces, At least comprising the method according to claims 38 to 59, as well as a step of dividing at least one crack-free SiC component (2300) into a plurality of predetermined components, Among them segmentation The steps preferably include: Cutting the defined volume portion using at least one wire saw or Use laser radiation to weaken the structure of a limited volume, thereby generating a limited laser cutting plane, and introduce external force to cause the crack to propagate along the limited laser cutting plane or Ions are implanted into a structure of a defined volume to generate a defined ion segmentation plane, and the pressure in the defined volume is increased by increasing the volume of implanted ions, in particular by heating the defined volume, so that cracks propagate along the defined ion segmentation plane.

61. The method according to claim 60, It is characterized in that The predetermined components (2314) are wafers, wherein the height of each wafer is between 200 μm and 1000 μm.

62. A method for producing a SiC carrier wafer, At least comprising the method according to claim 60 or 61, and comprising: A step of processing at least one cut or separated surface (2316) of the wafer, in particular grinding and / or lapping and / or polishing, to produce a processed surface having at least one defined surface property.

63. The method for producing a SiC carrier wafer according to claim 62, It is characterized in that The height of the SiC carrier wafer is reduced by processing at least one cutting surface or dividing surface (2316) so that the height of the at least one cutting surface or dividing surface (2316) is between 200 μm and 500 μm.

64. The method according to claim 62 or 63, Features Steps for analyzing SiC carrier wafers to identify defects, in particular cracks.

65. The method according to claim 64, It is characterized in that The step of analyzing the SiC component or the SiC carrier wafer to determine defects is performed by a bend test, in particular by a 2-point bend test, a 3-point bend test or a 4-point bend test, an eddy current test and / or an optical analysis method, in particular a caliper test or a threshold test.

66. A method for manufacturing a composite substrate (2320) At least comprising the method according to claim 62, 63, 64 and / or 65 and the following steps: A single crystal SiC wafer (2318) is bonded to the treated surface.

67. The method according to claim 66, It is characterized in that The single crystal SiC wafer is formed of a crystal structure, wherein the crystal structure defines a c-axis, wherein the crystal structure grows perpendicular to the c-axis, wherein the single-crystal SiC crystal has a preferably flat top surface, a preferably flat bottom surface, and a connecting surface connecting the top surface and the bottom surface, The angle of the c-axis relative to the normal to the top surface is between 0° and 8°, preferably between 2° and 6°, wherein the single crystal SiC wafer is preferably composed of 4H SiC.

68. The method according to claim 66 or 67, It is characterized in that A single crystal SiC layer is grown on a single crystal SiC wafer by an epitaxial method, wherein the single crystal SiC layer has a thickness between 1 μm and 50 μm, in particular between 2 μm and 40 μm, or between 3 μm and 30 μm, or between 4 μm and 20 μm, or between 5 μm and 10 μm.

69. The method of claim 66, 67 or 68, It is characterized in that A single crystal SiC crystal is formed from a crystal structure, wherein the crystal structure defines a c-axis, wherein the crystal structure grows perpendicular to the c-axis, wherein the single-crystal SiC crystal has a preferably flat top surface, a preferably flat bottom surface, and a connecting surface connecting the top surface and the bottom surface, The angle of the c-axis relative to the normal to the top surface is between 0° and 8°, preferably between 2° and 6°.

70. The composite substrate (2320) of claim 12, It is characterized in that Polycrystalline SiC crystals are composed of 4H-type SiC.

71. An electronic device, At least: The composite substrate (2320) according to claim 12 or 70, wherein at least one electronic component is grown or produced on or in a single-crystal SiC crystal layer as well as Therein, the thickness of the SiC carrier wafer is greater than 50 μm, in particular greater than 60 μm or greater than 80 μm or greater than 100 μm or greater than 150 μm or up to 350 μm.

72. A SiC production reactor for implementing the method according to any one of claims 38 to 59, At least: Craft Room (856), a gas inlet unit (866) for introducing one or more feed media into the reaction space of the process chamber (856), wherein the gas inlet unit (866) is coupled to at least one feed medium source (851), or The gas inlet unit (866) is coupled to at least two feed medium sources (851, 852). as well as one or more SiC growth substrates (857) for depositing SiC arranged in the process chamber (856), 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), wherein each SiC growth substrate (857) is coupled to a first power connection (859a) and a second power connection (859b), wherein the first power connection (859a) is a first metal electrode (206a), and wherein the second power connection (859b) is a second metal electrode (206b), The first metal electrode (206a) and the second metal electrode (206b) are preferably isolated from the reaction space in the process chamber (856). wherein 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 SiC growth surface (861) of the deposited SiC, in particular by resistive heating and preferably by internal resistance heating to a temperature between 1400° C. and 1700° C., AC current source, wherein 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 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, The process chamber (856) is at least surrounded by a bottom plate (862), a side wall portion (864a) and a top wall portion (864b). The bottom plate (862) comprises at least one cooling element (868, 870, 880), in particular a bottom cooling element, for preventing the bottom plate (862) from heating up to a temperature exceeding a defined temperature. and / or wherein the side wall portion (864a) comprises at least one cooling element (868, 870, 880), in particular a bell cooling element, for preventing the side wall portion (864a) from heating up above a defined temperature, and / or wherein the top wall portion (864b) comprises at least one cooling element (868, 870, 880), in particular a bell cooling element, for preventing the top wall portion (864b) from heating up to a temperature exceeding a defined temperature, wherein at least one cooling element (868) is a passive cooling element (880), wherein at least one cooling element (868) is 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), wherein the cooling element (868) is a coating (867), wherein the coating (867) is formed on top of the polished steel surface (865), and wherein the coating (867) is configured to reflect heat, The coating (867) is a metal coating or includes a metal, in particular silver, gold or chromium, or an alloy coating, in particular a CuNi alloy coating. Therein, the emissivity of the polished steel surface (865) and / or the coating (867) is below 0.3, in particular below 0.1 or below 0.

03.

73. The SiC production reactor according to claim 72, It is characterized in that A gas outlet unit (216) for outputting exhaust gas Exhaust gas recovery unit (600), The exhaust gas recovery unit (600) is connected to the gas outlet unit. The exhaust gas recovery unit (600) at least comprises: a separator unit (602) for separating the exhaust gas into a first fluid and a second fluid, The first fluid is a liquid, the second fluid is a gas, wherein the first storage and / or conduction element for storing or conducting the first fluid (624) is part of the separator unit (602) or is coupled to the separator unit (602), and Therein, a second storage and / or conduction element for storing or conducting a second fluid (626) is a part of the separator unit (602) or is coupled to the separator unit (602).

74. The SiC production reactor according to claim 73, It is characterized in that The exhaust gas recovery unit (600) comprises another separator unit (612) for separating the first fluid into: At least two parts, two of which are: - Chlorosilane mixtures, and - a mixture of HCl, H2 and at least one C-containing molecule, And preferably divided into at least three parts, wherein the three parts are: - a mixture of chlorosilanes, and -HCl and - a mixture of H2 and at least one C-containing molecule, Therein, a first storage and / or conducting element (624) connects the separator unit (602) to another separator unit (612).

75. The SiC production reactor of claim 74, It is characterized in that Another separator unit (612) is coupled to the chlorosilane mixture storage and / or conduction element (628), the HCl storage and / or conduction element (630), and the H2 and C storage and / or conduction element (632).

76. The SiC production reactor of claim 75, It is characterized in that The chlorosilane mixture storage and / or conducting element (628) forms part of a chlorosilane mixture mass flux path for conducting the chlorosilane mixture to the process chamber (856).

77. The SiC production reactor of claim 76, It is characterized in that A Si mass flux measurement unit (622) is provided for measuring the Si content of the chlorosilane mixture, the Si mass flux measurement unit (622) being part of a mass flux path before the process chamber (856), in particular before the mixing device (854), and preferably being another Si feed medium source for providing another Si feed medium.

78. The SiC production reactor of claim 75, It is characterized in that The chlorosilane mixture storage and / or conducting element (628) forms part of a chlorosilane mixture mass flux path for conducting the chlorosilane mixture to another process chamber (952) of another SiC production reactor (950).

79. The SiC production reactor according to claim 75, It is characterized in that The H2 and C storage and / or conduction element (632) forms part of a H2 and C mass flux path for conducting H2 and at least one C-containing molecule to the process chamber (850).

80. The SiC production reactor of claim 79, It is characterized in that A C mass flux measurement unit (618) is provided for measuring the C content in a mixture of H2 and at least one C-containing molecule, the C mass flux measurement unit being part of the H2 and C mass flux path before the process chamber (856), in particular before the mixing device (854), and preferably being another C feed medium source for providing another C feed medium.

81. The SiC production reactor of claim 75, It is characterized in that The H2 and C storage and / or conduction element (632) forms part of a H2 and C mass flux path for conducting H2 and at least one C-containing molecule to another process chamber (856) of another SiC production reactor (950).

82. The SiC production reactor according to any one of claims 75 to 81, It is characterized in that The second storage and / or conduction element (626) forms part of the H2 and C mass flux path for conducting a second fluid comprising H2 and at least one C-containing molecule to the process chamber (856), Wherein, the second storage and / or conduction element (626) is preferably fluidically coupled to the H2 and C storage and / or conduction element (632).

83. The SiC production reactor according to any one of claims 75 to 81, It is characterized in that The second storage and / or conduction element (626) forms part of another H2 and C mass flux path for conducting a second fluid comprising H2 and at least one C-containing molecule to the process chamber (856).

84. The SiC production reactor according to claim 83, It is characterized in that Another C mass flux measurement unit is provided for measuring the C content in the second fluid, and the other C mass flux measurement unit is provided as part of another H2 and C mass flux path before the process chamber (856), in particular before the mixing device (854).

85. The SiC production reactor according to any one of claims 75 to 81, It is characterized in that The second storage and / or conduction element (626) is coupled to a flare unit for combusting the second fluid.

86. The SiC production reactor according to any one of claims 75 to 85, It is characterized in that The separator unit (602) is configured to operate at a pressure above 5 bar and a temperature below -30°C.

87. The SiC production reactor according to claim 86, It is characterized in that A first compressor (634) is provided for compressing the exhaust gas to a pressure above 5 bar, wherein the first compressor (634) is a part of the separator unit (602) or is provided in the gas flow path between the gas outlet unit (216) and the separator unit (602).

88. The SiC production reactor according to any one of claims 75 to 85, It is characterized in that The other separator unit (612) is configured to operate at a pressure above 5 bar and a temperature below -30°C and / or a temperature above 100°C.

89. The SiC production reactor according to claim 88, It is characterized in that A further compressor (636) is provided for compressing the first fluid to a pressure above 5 bar, the further compressor (636) being part of the further separator unit (612) or being provided in the gas flow path between the separator unit (602) and the further separator unit (612).

90. The SiC production reactor according to claim 88 or 89, It is characterized in that Another separator unit (612) comprises a cryogenic distillation unit, wherein the cryogenic distillation unit is preferably configured to operate at a temperature between -180°C and -40°C.

91. The SiC production reactor according to claims 75 to 90, It is characterized in that A control unit (929) is provided for controlling the fluid flow of one or more feed media, wherein the control unit (929) is part of a SiC production reactor (850), wherein the multiple feed media include a first medium, a second medium, a third medium, and additional Si feed media and / or additional C feed media entering the process chamber (856) through a gas inlet unit.

92. The SiC production reactor according to claim 91, It is characterized in that The further Si feed medium consists of at least 95% by mass, or at least 98% by mass, or at least 99% by mass, or at least 99.9% by mass, or at least 99.99% by mass, or at least 99.999% by mass of the chlorosilane mixture.

93. The SiC production reactor according to claim 91 or 92, It is characterized in that The additional C feed medium comprises at least one C-containing molecule, HCl, H2 and a chlorosilane mixture, wherein the additional C feed medium comprises at least 3 mass % or preferably at least 5 mass % or more preferably at least 10 mass % of at least one C-containing molecule, and wherein the additional C feed medium comprises up to 10 mass % or preferably 0.001 to 10 mass %, more preferably 1 to 5 mass % HCl, and wherein the additional C feed medium contains more than 5 mass % or preferably more than 10 mass % or more preferably more than 25 mass % H2, and Therein, the additional C feed medium contains more than 0.01% by mass or preferably more than 1% by mass, more preferably 0.001% by mass to 10% by mass of the chlorosilane mixture.

94. The SiC production reactor according to claims 75 to 93, It is characterized in that The heating unit (954) is arranged along the fluid flow direction between the other separator unit and the gas inlet unit, and is used to heat the chlorosilane mixture to convert the chlorosilane mixture from a liquid state to a gas state.

95. The SiC production reactor according to claim 94 It is characterized in that The bottom plate (862) comprises at least one additional cooling element (868, 870, 880), in particular a bottom cooling element, for preventing the bottom plate (862) from heating up above a defined temperature, and / or wherein the side wall portion (864a) comprises at least one additional cooling element (868, 870, 880), in particular a bell cooling element, for preventing the side wall portion (864a) from heating up above a defined temperature, and / or wherein the top wall portion (864b) comprises at least one additional cooling element (868, 870, 880), in particular a bell cooling element, for preventing the top wall portion (864b) from heating up to a temperature exceeding a defined temperature, Therein, the additional cooling element is an active cooling element (870).

96. The SiC production reactor of claim 95, It is characterized in that The bottom plate (862) and / or the side wall portion (864a) and / or the top wall portion (864b) include cooling fluid guiding units (872, 874, 876) for guiding cooling fluid, 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.

97. The SiC production reactor of claim 96, It is characterized in that A bottom plate and / or side wall portion and / or top wall portion sensor unit (890) is provided to detect the temperature of the bottom plate (862) and / or side wall portion (864a) and / or top wall portion (864b) and output a temperature signal or temperature data, and / or a cooling fluid temperature sensor is provided to detect the temperature of the cooling fluid, and A fluid delivery unit (873) is provided for delivering cooling fluid through the fluid guiding units (872, 874, 876), Wherein, the fluid delivery unit (873) is preferably configured to operate according to the temperature signal or temperature data provided by the bottom plate and / or side wall part and / or top wall part sensor unit (890) and / or the cooling fluid temperature sensor (892).

98. The SiC production reactor of claim 97, It is characterized in that The cooling fluid is water.

99. The SiC production reactor according to any one of claims 90 to 98, It is characterized in that The bottom plate (862) includes at least one active cooling element (870) and one passive cooling element (880) for preventing the bottom plate (862) from heating up to a temperature exceeding a limit. and / or The side wall portion (864a) includes at least one active cooling element (870) and one passive cooling element (880) for preventing the side wall portion (864a) from heating up to a temperature exceeding a defined temperature. and / or The top wall portion (864b) includes at least one active cooling element (870) and one passive cooling element (880) for preventing the top wall portion (864b) from heating above a defined temperature.

100. The SiC production reactor according to any one of claims 90 to 99, It is characterized in that The side wall portion (864a) and the top wall portion (864b) are formed by a bell jar (864), wherein the bell jar (864) is preferably movable relative to the base plate (862).

101. The SiC production reactor according to claim 100, It is characterized in that More than 50% by mass of the side wall portion (864a) and / or more than 50% by mass of the top wall portion (864b) and / or more than 50% by mass of the bottom plate (862) are made of metal, in particular steel.

102. The SiC production reactor of claim 72, It is characterized in that The carrier gas medium source (853) provides a third feed medium, in particular, H2.

103. The SiC production reactor according to claim 72 or 102, It is characterized in that The Si and C feed medium source (851) provides at least Si and C, and in particular provides SiCl3 (CH3).

104. The SiC production reactor according to claim 72 It is characterized in that in, The Si feed medium source (851) provides at least Si, In particular, a Si feed medium source (851) provides a first feed medium, The first feed medium is a Si feed medium, in particular a feed medium according to the general formula SiH 4-y X y (X = [Cl, F, Br, J] and y = [0..4] Si gas, and Wherein, the C feed medium source (852) provides at least C, In particular, the C feed medium source (852) provides a second feed medium, The second feed medium is a C feed medium, in particular natural gas, methane, ethane, propane, butane and / or acetylene.

105. The SiC production reactor according to claim 72 or 104, It is characterized in that The carrier gas medium source (853) provides a third feed medium, The third feed medium is a carrier gas, in particular H2.

106. The method according to any one of claims 13 to 58, It is characterized in that After the growth is completed, the grown SiC solid (211) is heated for a defined time. Wherein, the defined time is greater than 1 hour, in particular greater than 2 hours, preferably greater than 3 hours, particularly preferably greater than 5 hours, most preferably greater than 10 hours or up to 24 hours, Therein, the electrical energy used to heat the SiC solid (211) is reduced continuously and / or stepwise within a limited time.

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