CN116829770A

CN116829770A - Method and device for producing SiC solid material

Info

Publication number: CN116829770A
Application number: CN202180089271.7A
Authority: CN
Inventors: I·克罗斯曼; F·夏福; H·R·提费; K·赛兰
Original assignee: Zadiante Technology Co ltd
Current assignee: Zadiante Technology Co ltd
Priority date: 2020-12-11
Filing date: 2021-12-13
Publication date: 2023-09-29
Also published as: WO2022123072A1; EP4259863A1

Abstract

The present invention relates to a method of manufacturing a SiC solid, preferably an elongated SiC solid, in particular polytype 3C SiC solid. The method of the present invention preferably comprises at least the steps of: introducing at least one first source gas into the 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; supplying power to at least one separator assembly disposed in the process chamber to heat the separator assembly, setting the deposition rate to be in excess of 200 μm/h, wherein a pressure in excess of 1 bar is generated in the process chamber by introducing the first source gas and/or the second source gas, and wherein the deposition assembly surface is heated to a temperature in the range between 1300 ℃ and 1700 ℃.

Description

Method and device for producing SiC solid material

Technical Field

The present invention relates to a method according to claims 1 and 3, respectively, for producing a preferably elongated SiC solid, in particular a polytype 3C SiC solid, to a device according to claims 12 and 13, respectively, for producing a preferably elongated SiC solid, in particular a polytype 3C SiC solid, in particular for carrying out the method, to a SiC solid material according to claim 14, in particular a 3C-SiC solid material, and to the use of a SiC solid material according to claim 15 in a PVT reactor for producing monocrystalline SiC.

Background

DE1184738 (B) discloses a process for producing silicon carbide crystals in single and polycrystalline form by reacting silicon halide in a molar ratio of carbon tetrachloride to 1:1 on a heated graphite body in the presence of hydrogen. In this process, a mixture of 1 volume percent chloroform and 1 volume percent carbon tetrachloride with hydrogen is first conveyed through the graphite body at a flow rate of 400 to 600l/h until a compacted silicon carbide layer is formed on the graphite body, and then through the deposition body at 1500 to 1600 ℃ at a flow rate of 250 to 350 l/h.

This prior art is disadvantageous in that it does not meet the current demand for inexpensive usable and high purity SiC. SiC is used in many technical fields, especially in electrical applications and/or in electric vehicles, to increase efficiency. In order for SiC-requiring products to be available in the mass market, manufacturing costs must be reduced and/or quality must be improved.

It is therefore an object of the present invention to provide a low cost silicon carbide (SiC) supply. In addition or alternatively, high purity SiC must be provided. In addition or alternatively SiC must be provided very rapidly. In addition or alternatively SiC must be manufactured very efficiently. In addition or alternatively, single crystal SiC having advantageous properties has to be produced.

Disclosure of Invention

The above object is solved according to the invention by a method for producing preferably elongated SiC solids, in particular polytype 3C, according to claim 1. The method of the present invention preferably comprises at least the steps of:

introducing at least a first source gas into the process chamber, the first source gas comprising Si; introducing at least a second source gas into the process chamber, the second source gas comprising C; charging at least one deposition assembly disposed in the process chamber to heat the deposition assembly; and setting a deposition rate to be more than 200 μm/h, wherein a pressure of more than 1 bar is generated in the process chamber by introducing the first source gas and/or the second source gas, and wherein the surface of the deposition assembly is heated to a temperature in a range between 1300 ℃ and 1700 ℃.

This solution is advantageous because the deposition assembly can grow very fast due to the parameters chosen. This rapid growth has a significant impact on the overall cost, and SiC can be manufactured at significantly lower cost compared to the prior art.

According to a preferred embodiment of the present invention, the method of the present invention comprises the step of introducing at least one carrier gas into the process chamber, wherein the carrier gas preferably comprises H.

This embodiment is advantageous because the carrier gas can be used to create an advantageous gas flow in the process chamber.

The above object is also solved according to the invention by a method for manufacturing preferably elongated SiC solids, in particular polytype 3C, according to claim 3. The method of the present invention preferably comprises the steps of:

at least one source gas, in particular a first source gas, in particular SiCl ₃ (CH ₃ ) Introducing into the process chamber, the source gas comprising Si and C; introducing at least one carrier gas into the process chamber, the carrier gas preferably comprising H; charging at least one deposition assembly disposed in the process chamber to heat the deposition assembly; setting the deposition rate to exceed200 μm/h, wherein a pressure of more than 1 bar is generated in the process chamber by introducing the source gas and/or carrier gas, and wherein the deposition assembly surface is heated to a temperature in the range between 1300 ℃ and 1700 ℃ or between 1300 ℃ and 1700 ℃.

In accordance with a preferred embodiment of the present invention, the method also includes the step of introducing at least a second source gas into the process chamber, wherein the second source gas includes C.

Further preferred embodiments of the invention are the subject matter of the following description of the invention and/or of the dependent claims.

According to a further preferred embodiment of the invention, the first source gas and/or the second source gas is introduced to generate a pressure in the process chamber of between 2 and 10 bar, preferably the first source gas and/or the second source gas is introduced to generate a pressure in the process chamber of between 4 and 8 bar, particularly preferably the first source gas and/or the second source gas is introduced to generate a pressure in the process chamber of between 5 and 7 bar, especially 6 bar.

This embodiment is advantageous because the pressure increase provides more starting material, which is arranged on or through the deposition assembly in the form of SiC.

According to another preferred embodiment of the invention, the surface of the deposition assembly is heated to a temperature in the range between 1450 and 1700 ℃, in particular between 1500 and 1600 ℃, or between 1490 and 1680 ℃.

This embodiment is advantageous because an environment is established in which very pure SiC is deposited on the deposition assembly. In particular, it has been recognized that too low a temperature increases the proportion of Si deposited on the deposition assembly, and too high a temperature increases the proportion of C deposited on the deposition assembly. However, siC is the purest in the above temperature range.

According to another preferred embodiment of the present invention, a first source gas is introduced into the process chamber through a first supply means, and a second source gas is introduced into the process chamber through a second supply means; or mixing the first source gas and the second source gas before introducing the first source gas into the processing chamber and introducing the first source gas into the processing chamber through a supply device, wherein the source gases are mixed and introduced into the processing chamber in a Si to C mole ratio of Si=1 and C=0.8 to 1.1 and/or a Si to C atomic ratio of Si=1 and C=0.8 to 1.1. This is advantageous because it allows very precise adjustment of the Si: C ratio=1:1 in the SiC solid material via the molar ratio of the two gases.

This embodiment is advantageous because it produces a gaseous composition in the process chamber that deposits very pure SiC on the deposition assembly.

According to another preferred embodiment of the invention, the carrier gas comprises H, wherein the source gas and the carrier gas are present in Si: C: H molar ratios of si=1 and c=0.8 to 1.1 and h=2 to 10, in particular Si: C: H molar ratios of si=1 and c=0.9 to 1 and h=3 to 5, and/or Si: C: H atomic ratios of si=1 and c=0.8 to 1.1 and h=2 to 10, in particular Si: C: H atomic ratios of si=1 and c=0.9 to 1 and h=3 to 5, are introduced into the process chamber.

The following atomic or molar ratios are preferred for the deposition: h ₂ :SiCl ₄ :CH ₄ =5:1:1, or H ₂ :SiCl ₄ :CH ₄ =6:1:1, or H ₂ :SiCl ₄ :CH ₄ =7:1:1, or H ₂ :SiCl ₄ :CH ₄ =8:1:1, or H ₂ :SiCl ₄ :CH ₄ =9:1:1, or H ₂ :SiCl ₄ :CH ₄ ＝10:1:1。

Thus, during deposition H ₂ :SiCl ₄ :CH ₄ The atomic ratio or molar ratio between them is preferably between 5:1:1 and 10:1:1.

Preferably a fixed set of atomic or molar ratios is maintained during deposition, which may also be better suited for varying flow rates. It is particularly preferred that the total pressure or the pressure in the process chamber is also kept fixed during deposition.

This embodiment is advantageous in that the gas composition generated in the process chamber and the advantageous gas transport in the process chamber are produced, by which very pure SiC is deposited very rapidly on the deposition assembly.

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

This embodiment is advantageous because it can very much more desirably transform the manufacture of SiC materials.

According to another preferred embodiment of the present invention, the first source gas is SiCl ₄ 、SiHCl ₃ Or SiCl ₄ And the second source gas is CH ₄ Or C ₃ H ₈ Wherein the first source gas is preferably SiCl ₄ The second source gas is CH ₄ Or wherein the preferred first source gas is SiHCl ₃ The second source gas is CH ₄ Or wherein the first source gas is preferably SiCl ₄ The second source gas is C ₃ H ₈ 。

This embodiment is advantageous because these source gases can provide optimal Si and C for deposition.

Preferably the source gas or the source gas and/or carrier gas are of a purity that excludes at least 99.9999% (weight ppm) of impurities, especially substance B, al, P, ti, V, fe, ni.

Thus, preferably less than 1 ppm by weight of impurities, particularly substance B, al, P, ti, V, fe, ni, are components of the expanding gas and/or carrier gas; or less than 0.1 ppm by weight of impurities, particularly substance B, al, P, ti, V, fe, ni, as a component of the expanding gas and/or carrier gas; or less than 0.01 ppm by weight of foreign substances, especially substance B, al, P, ti, V, fe, ni, are components of the expanding gas and/or carrier gas.

Particularly preferably less than 1 ppm by weight of substance B is a component of the expanding gas and/or carrier gas. Particularly preferably less than 1 ppm by weight of Al is a component of the expanding gas and/or carrier gas. Particularly preferably less than 1 ppm by weight of substance P is a component of the expanding gas and/or carrier gas. Particularly preferably less than 1 ppm by weight of the substance Ti is a component of the source gas and/or carrier gas. Particularly preferably less than 1 ppm by weight of substance V is a component of the expanding gas and/or carrier gas. Particularly preferably less than 1 ppm by weight of Fe as a component of the expanding gas and/or carrier gas. Particularly preferably less than 1 ppm by weight of Ni as a constituent of the expanding gas and/or carrier gas.

Particularly preferably less than 0.1 ppm by weight of substance B is a component of the expanding gas and/or carrier gas. Particularly preferably less than 0.1 ppm by weight of Al as a component of the source gas and/or carrier gas. Particularly preferably less than 0.1 ppm by weight of substance P is a component of the expanding gas and/or carrier gas. Particularly preferably less than 0.1 ppm by weight of the substance Ti is a component of the source gas and/or carrier gas. Particularly preferably less than 0.1 ppm by weight of substance V is a component of the expanding gas and/or carrier gas. Particularly preferably less than 0.1 ppm by weight of Fe as a component of the source gas and/or carrier gas. Particularly preferably less than 0.1 ppm by weight of Ni as a component of the source gas and/or carrier gas.

Particularly preferably less than 0.01 ppm by weight of substance B is a component of the source gas and/or carrier gas. Particularly preferably less than 0.01 ppm by weight of Al as a component of the source gas and/or carrier gas. Particularly preferably less than 0.01 ppm by weight of substance P is a component of the source gas and/or carrier gas. Particularly preferably less than 0.01 ppm by weight of the substance Ti is a component of the source gas and/or carrier gas. Particularly preferably less than 0.01 ppm by weight of substance V is a component of the source gas and/or carrier gas. Particularly preferably less than 0.01 ppm by weight of Fe as a component of the source gas and/or carrier gas. Particularly preferably less than 0.01 ppm by weight of Ni as a component of the source gas and/or carrier gas.

According to a further preferred embodiment of the invention, the surface temperature of the deposition assembly is measured using a temperature measuring device, in particular a pyrometer. Preferably the temperature measuring device outputs a temperature signal and/or temperature data. Particularly preferred is a control device modification, in particular an increase, of the electrical load of the separator assembly as a function of the temperature signal and/or the temperature data.

This embodiment is advantageous in that it compensates for the adverse effects caused by growth. In particular as a result of SiC formation or deposition, the mass of the deposited component increases, as a result of which the temperature of the deposited component changes, in particular decreases, at the same electrical load. This results in an increase in Si content. By modifying, in particular increasing, the supply, in particular increasing, the current, temperature variations can be compensated or reversed.

According to a further preferred embodiment of the invention, the temperature measuring device performs temperature measurements and outputs temperature signals and/or temperature data at time intervals of less than 5 minutes, in particular less than 3 minutes, or less than 2 minutes, or less than 1 minute, or less than 30 seconds. Preferably defining a target temperature or target temperature range. The control means preferably controls the power supply increase as long as the temperature signal and/or the temperature data indicate that the surface temperature is below a defined critical temperature, which is a temperature below a defined value below the set temperature, or a lower limit of a set temperature range. The defined value is preferably less than 10 ℃, or less than 5 ℃, or less than 3 ℃, or less than 2 ℃, or less than 1.5 ℃, or less than 1 ℃.

This embodiment is advantageous in that very accurate temperature changes can be detected and compensated or reversed. As a result, very high purity can be obtained. The current or amperage may thus preferably be increased by a factor of up to 1.1, or 1.5, or 1.8, or 2, or 2.3, or 2.5, or 2.8, or 3, or 3.5, or 5, or 10 during the deposition time. The current or amperage may thus preferably be increased by at least a factor of 1.1, or 1.5, or 1.8, or 2, or 2.3, or 2.5, or 2.8, or 3, or 3.5, or 5, or 10 over the deposition time.

According to a further preferred embodiment of the invention, more source gases, in particular the first source gas and/or the second source gas, are introduced into the process chamber continuously or stepwise, in particular in defined proportions, per unit time. Preferably more source gas, in particular the first source gas and/or the second source gas, is introduced into the process chamber as a function of time and/or more source gas, in particular the first source gas and/or the second source gas, is introduced into the process chamber as an electrical load function.

This embodiment is advantageous because the source gas quality can accommodate the increased surface area of the deposition assembly. As a result, the optimum amounts (mass) of Si and C are preferably maintained in the chamber throughout the process.

The above object is also solved by a device for producing preferably elongated SiC solids, in particular polytype 3C, in particular for carrying out the aforementioned method, according to claim 12. The apparatus of the present invention preferably comprises at least one processing chamber for receiving a rechargeable deposition element; a first source gas, wherein the first source gas comprises Si; a second source gas, wherein the second source gas comprises C; the first feeding device and/or the second feeding device; first and/or second supply means for introducing the first and/or second source gases into the process chamber at a pressure exceeding 1 bar; a temperature measuring device for measuring a surface temperature of the deposition assembly; and control means for setting the deposition rate to be more than 200 μm/h. Preferably the control means is operable to adjust the power to the separator assembly, the power being adjustable from 1300 ℃ to 1700 ℃ to produce the surface temperature.

The above object is also solved by a device for producing preferably elongated SiC solids, in particular polytype 3C, in particular for carrying out the aforementioned method, according to claim 13. The apparatus of the present invention preferably comprises at least one processing chamber for receiving a rechargeable deposition element; at least one source gas, in particular SiCl ₃ (CH ₃ ) Wherein the source gas comprises Si and C; and a carrier gas, wherein the carrier gas preferably comprises H; first and/or second supply means for introducing source and/or carrier gases into the process chamber at a pressure exceeding 1 bar; a temperature measuring device for measuring a surface temperature of the deposition assembly; and control means for setting the deposition rate to be more than 200 μm/h. Preferably the control means is operable to adjust the power to the separator assembly, the power being adjustable from 1300 ℃ to 1700 ℃ to produce the surface temperature.

Within the scope of the invention, the separating element, which is preferably described in all embodiments, is preferably an elongated body, which preferably consists of graphite or carbon or SiC, or which has graphite or carbon or SiC. The separation element may also be made of graphite or carbon or SiC plates, in particular having a thickness of less than 5mm, or less than 2mm, or less than 1mm, or less than 0.1mm, arranged thereon or covered therewith. Alternatively, a SiC layer may be grown on graphite. The SiC plate and/or the grown SiC layer may be, for example, monocrystalline or polycrystalline. The deposition assembly is preferably coupled to the first electrical contact in the region of its longitudinally extending first end, particularly closer to the longitudinally extending first end than to its longitudinally extending second end. In addition, the deposition assembly is preferably coupled to the second electrical contact in the region of its longitudinally extending second end, particularly closer to its longitudinally extending second end than the first end. Preferably, to heat the separator element, an electric current is introduced into the separator element via one of the two contacts and discharged from the separator element via the other contact.

In addition, according to claim 14, substances B, al, P, ti, V, fe, ni of at least 99.9999% (weight ppm) and/or substances having a density of less than 3.21g/cm are excluded by purity for the above purposes ³ Is solved by the SiC solid material, in particular the 3C-SiC solid material.

The SiC solid material or deposition component (after the deposition process is terminated) preferably has a diameter of at least or exactly 4 inches, or at least or exactly or up to 6 inches, or at least or exactly or up to 8 inches, or at least or exactly or up to 10 inches.

Preferably the SiC solid state material of the invention is manufactured by a method according to any one of claims 1 to 11. Preferably the purity of the SiC solid material excludes at least 99.9999% (weight ppm) of substance B, al, P, ti, V, fe, ni. Such preferably less than 1 ppm by weight of substance B, al, P, ti, V, fe, ni is part of the SiC solid material, or less than 0.1 ppm by weight of substance B, al, P, ti, V, fe, ni is part of the SiC solid material, or less than 0.01 ppm by weight of substance B, al, P, ti, V, fe, ni is part of the SiC solid material.

Particularly preferably less than 1 ppm by weight of substance B is a component of the SiC material. Particularly preferably less than 1 ppm by weight of Al is a component of the SiC material. Particularly preferably less than 1 ppm by weight of substance P is a component of the SiC material. Particularly preferably less than 1 ppm by weight of Ti is a component of the SiC material. Particularly preferably less than 1 ppm by weight of substance V is a component of the SiC material. Particularly preferably less than 1 ppm by weight of Fe as a component of the SiC material. Particularly preferably less than 1 ppm by weight of Ni is a component of the SiC material.

Particularly preferably less than 0.1 ppm by weight of substance B is a component of the SiC material. Particularly preferably less than 0.1 ppm by weight of Al is a component of the SiC material. Particularly preferably less than 0.1 ppm by weight of substance P is a component of the SiC material. Particularly preferably less than 0.1 ppm by weight of Ti is a component of the SiC material. Particularly preferably less than 0.1 ppm by weight of substance V is a component of the SiC material. Particularly preferably less than 0.1 ppm by weight of Fe as a component of the SiC material. Particularly preferably less than 0.1 ppm by weight of Ni as a substance is a component of the SiC material.

Particularly preferably less than 0.01 ppm by weight of substance B is a component of the SiC material. Particularly preferably less than 0.01 ppm by weight of Al is a component of the SiC material. Particularly preferably less than 0.01 ppm by weight of substance P is a component of the SiC material. Particularly preferably less than 0.01 ppm by weight of Ti is a component of the SiC material. Particularly preferably less than 0.01 ppm by weight of substance V is a component of the SiC material. Particularly preferably less than 0.01 ppm by weight of Fe as a component of the SiC material. Particularly preferably less than 0.01 ppm by weight of Ni as a substance is a component of the SiC material.

In the context of the present patent specification, weight ppm (ppm wt) is preferably understood as weight ppm (wt ppm).

Furthermore, the above object is solved by the use of a SiC solid material according to claim 14 in a PVT reactor for manufacturing single crystal SiC.

Furthermore, the above object is solved by the use of the above SiC solid material or the SiC solid material according to claim 14 in a PVT reactor (pvt=physical vapor transport method) for manufacturing single crystal SiC.

This solution is advantageous because pure SiC solid material provides a very advantageous starting material for PVT processes. On the other hand, this material is advantageous because it can be obtained as a solid mass. This solid mass can then be crushed, for example, into pieces having a defined minimum size or mass or volume. Whereby preferably at least 50% by weight, or at least 70% by weight, or at least 80% by weight, or at least 90% by weight, or at least 950% by weight of the SiC solid material is disintegrated to a volume of more than 0.5cm ³ Or greater than 1cm ³ Or greater than 1.5cm ³ Or 2cm ³ Or 5cm ³ Is a fragment of (c).

Alternatively, the solid mass may be divided, in particular split or sawed, into a plurality of preferably at least substantially uniform pieces, in particular perpendicularly to its longitudinal axis or direction of extension. Preferably the cut pieces are cut pieces having a minimum thickness of 0.5cm, or 1cm, or 3cm, or 5cm, especially a thickness of at most 20cm, or 30cm, or 50 cm. Both cases (crushing or splitting) can provide solids with minimal size. This is advantageous because when SiC solid material (starting material) is heated, a significantly more uniform temperature distribution in the starting material is possible and results in a significantly more uniform vaporization of the starting material compared to very fine-grained starting materials used in PVT processes. In addition, in the case of very fine-grained starting materials, the relative movement between the individual material pieces occurs due to rising vapors and material removal of the individual material pieces, resulting in turbulence that negatively affects the crystal growth process. These disadvantages are precluded by the use of large fragments or portions.

This solution is more advantageous because the total surface area is significantly smaller due to the larger fragments or fractions than when very fine-grained starting materials are used. Therefore, the total surface area is easier to measure and serve as a parameter for PVT process adjustment.

This solution is more advantageous because, due to the low density of the SiC solid material produced by the present invention, the transition of the boundary layer can occur faster to form the surface of the solid material.

The SiC solid material produced according to the invention, in particular the 3C-SiC solid material, is preferably introduced into a reactor or furnace apparatus or PVT reactor as described above, having at least the following features: the novel reactor is preferably a reactor for crystal growth, in particular for SiC crystal growth or a PVT reactor. The reactor or furnace apparatus also comprises at least one or more or exactly one crucible or crucible unit, wherein the at least one crucible or crucible unit is arranged within the furnace volume. The crucible or crucible unit includes and has or forms a crucible enclosure forming an enclosure having an outer surface and an inner surface, the inner surface at least partially defining a crucible volume. A receiving space for receiving the starting material is arranged or formed within the crucible volume. Preferably also provided is a seed holder unit for receiving a defined wafer 18, which is arranged in particular within the crucible volume, or this seed holder unit may be arranged within the crucible volume. The reactor or oven device also has at least one heating unit, in particular for heating the starting material and/or the crucible shell of the crucible unit. If a seed holder unit is provided, a receiving space for receiving the starting material is preferably arranged at least partially between the heating unit and the seed holder unit.

This oven arrangement is advantageous in that it can be modified in one or more ways to accomplish at least one of the above-mentioned purposes, or several or all of the above-mentioned purposes.

Other preferred embodiments are the subject matter of other portions of the description and/or the dependent claims.

According to a preferred embodiment of the invention, the furnace apparatus further comprises at least one leak prevention means for preventing leakage of gaseous silicon from the interior of the crucible or crucible unit into a portion of the furnace volume surrounding the crucible unit during operation. This design is advantageous because it eliminates the drawbacks of leaky Si vapors.

According to another preferred embodiment of the present invention, the leakage preventing agent is selected from a group of leakage preventing agents. The set of leakage prevention means preferably comprises at least (a) a covering component for covering the surface portion and/or a density increasing component for increasing the density of the crucible shell volume section of the crucible unit; (b) a filter unit for collecting gaseous Si; and/or (c) a pressure unit for establishing a first pressure inside the crucible unit and a second pressure inside the furnace but outside the crucible unit, the second pressure being higher than the first pressure; (d) A seal arranged between the crucible unit housing parts. This embodiment is advantageous in that it provides improved furnace apparatus by providing a number of features. Which may provide one or more or all of the features of the set of leakage prevention means to the oven apparatus. The invention thus also provides a solution to different demands, in particular for different products, in particular crystals of different properties.

According to another preferred embodiment of the invention, the leakage preventing agent reduces the leakage of sublimation vapors, in particular Si vapors, generated during one run from the crucible volume through the crucible shell into the furnace volume, in particular by at least 50 mass%, or at least 80 mass%, or at least 90 mass%, or more than 99 mass%, or at least 99.9 mass%. This embodiment is advantageous because components such as the crucible housing and the heating unit may be reused many times, in particular more than 10 times, or more than 20 times, or more than 50 times, or more than 100 times, due to the significantly reduced leakage in the Si vapor furnace. Thus, the penetration force of the crucible shell, or crucible unit segment, or crucible shell segment is less than 10 ^-2 cm ² /s, or less than 10 ^-5 cm ² /s, or less than 10 ^-10 cm ² S, in particular for Si vapors.

According to a further preferred embodiment of the invention, the crucible shell comprises carbon, in particular at least 50% (by mass) of the crucible shell consists of carbon, and preferably at least 80% (by mass) of the crucible shell consists of carbon, and most preferably at least 90% (by mass) of the crucible shell consists of carbon, or the crucible shell consists entirely of carbon, in particular the crucible shell comprises or consists of at least 90% (by mass) of graphite, while being subjected to temperatures above 2000 ℃, in particular at least or at most 3000 ℃, or at most 3500 ℃, or at most 4000 ℃, or at least at most 4000 ℃. The crucible enclosure is preferably impermeable to silicon gas (Si vapor). This design is advantageous because it prevents Si vapor from penetrating through the crucible enclosure and damaging the crucible enclosure and components external to the crucible enclosure. Additionally or alternatively, the crucible unit or crucible housing structure or crucible housing has vitreous carbon coated graphite and/or solid vitreous carbon and/or thermal carbon coated (pyrocarbon coated) graphite and/or tantalum carbide coated graphite and/or solid tantalum carbide.

According to another preferred embodiment of the invention, the leakage protection device is a cover member for covering a surface of the housing, in particular an inner surface and/or an outer surface, or for covering a surface portion of the housing, in particular a surface portion of an inner surface of the housing and/or a surface portion of an outer surface of the housing. This embodiment is advantageous in that the cover element may be produced on the housing surface or may be attached to the housing surface. However, it can implement either of these two steps (creation/attachment) in a cost-effective and reliable manner.

According to another preferred embodiment of the present invention, the cover member is a sealing member, wherein the sealing member is a coating. The coating preferably consists of a material or a combination of materials which reduces the leakage of sublimation vapors, in particular Si vapors, generated during one operation from the crucible volume through the crucible shell into the furnace volume, in particular by at least 50% by mass, or at least 80% by mass, or at least 90% by mass, or more than 99% by mass, or at least 99.9% by mass.

The coating preferably withstands temperatures above 2000 ℃, in particular at least or up to 3000 ℃ or at least up to 3000 ℃, or up to 3500 ℃ or at least up to 3500 ℃, or up to 4000 ℃ or at least up to 4000 ℃. This embodiment is advantageous because the modified crucible unit has at least two layers of material, one forming the crucible shell and the other reducing the penetration of Si vapor. The coating is most preferably a material comprising one or more materials selected from the group comprising at least carbon, especially thermal carbon and vitreous carbon. The crucible unit, in particular the crucible housing or the housing of the crucible unit, is therefore preferably coated with hot carbon and/or vitreous carbon. The thickness of the layer of hot carbon is preferably more than or up to 10 μm, especially more than or up to 20 μm, or more than or up to 50 μm, or more than or up to 100 μm, or more than or up to 200 μm, or more than or up to 500 μm. The glassy carbon layer preferably has a thickness of more than or up to 10 μm, especially more than or up to 20 μm, or more than or up to 50 μm, or more than or up to 100 μm, or more than or up to 200 μm, or more than or up to 500 μm.

According to a further preferred embodiment of the invention, the coating is produced by chemical vapor deposition or wherein the coating is produced by brushing, in particular on a precursor material, in particular phenol formaldehyde, and pyrolysed after brushing. This embodiment is advantageous in that the coating can be produced in a reliable manner.

According to another preferred embodiment of the invention, the leakage protection agent is a density increasing component or sealing component for increasing the density of the crucible shell volume portion of the crucible unit, wherein the density increasing component is arranged or generated in the inner structure of the crucible shell, wherein the density increasing component is a sealing component, wherein the sealing component prevents leakage of sublimation vapors, in particular Si vapors, generated during one operation from the crucible volume through the crucible shell into the furnace volume, in particular leakage of at least 50 mass%, or at least 80 mass%, or at least 90 mass%, or more than 99 mass%, or at least 99.9 mass%. This embodiment is advantageous because the dimensions of the crucible unit remain the same or similar or are not affected by the modification. The seal assembly is preferably created inside the crucible enclosure by dipping or deposition.

According to another preferred embodiment of the invention, the leakage prevention means is a filter unit for collecting gaseous Si. The filter unit includes a filter body having a filter input surface or section for introducing a gas containing SiC species vapor, si vapor, and process gas into the filter body, and an output section or filter output surface for outputting filtered process gas. A filter assembly is disposed between the filter input surface and the filter output surface, the filter assembly forming a trap section for absorbing and condensing SiC species vapors, particularly Si vapors. Therefore, the filter material is preferably adapted to cause Si vapor to flow in the filterAbsorption and condensation on the surface of the material. This design is advantageous because the total amount of Si vapor inside the crucible unit can be significantly reduced by means of the filter unit. It also significantly reduces the amount of Si vapor that can escape. Most and preferably all of the Si vapors are preferably collected as a film of condensed liquid on the inner surface of the filter. Additionally or alternatively, a section is defined in the uppermost part of the filter at a temperature below the melting point of Si and where the condensed vapors are substantially solidified. Preferably, the Si vapor does not solidify into particles, and preferably a solid film is produced on the filter inner surface. The film may be amorphous or polycrystalline. Excessive Si ₂ C and SiC ₂ The vapor preferably also reaches the lower region of the filter and is deposited thereon, preferably as solid polycrystalline deposits on the inner surface.

In accordance with a preferred embodiment of the present invention, the filter assembly forms or defines a gas flow path from the filter inlet surface to the outlet surface. The filter assembly has a height S1 and wherein the gas flow path through the filter assembly has a length S2, wherein S2 is preferably at least 10 times longer than S1, especially S2 is at least 100 times longer than S1, or S2 is at least or at most 1000 times longer than S1, or S2 is at least or at most 10000 times longer than S1. This embodiment is advantageous in that the filter unit has the ability to absorb or trap more than or at most 50 mass%, in particular more than or at most 50 mass%, or more than or at most 70 mass%, or more than or at most 90 mass%, or more than or at most 95 mass%, or more than or at most 99 mass% of the Si vapor generated by the vaporization of the raw material, in particular the vaporization of the raw material used or required during one run. "one run" preferably means the production or production of crystals, in particular SiC crystals or SiC cakes or SiC embryoid bodies.

According to another preferred embodiment of the invention, the filter unit is arranged between the first part of the crucible unit housing and the second part of the crucible unit housing, in particular between the crucible cover or the filter cover. At least 50% by volume, in particular at least 80% by volume or at least 90% by volume of the first part of the crucible unit housing is arranged vertically below the seed holder unit, wherein a first crucible volume is present between the first part of the crucible unit housing and the seed holder, wherein the first crucible volume can be operated in such a way that at least 80%, or preferably 90%, or even more preferably 100% of the first crucible volume is above the condensation temperature Tc of silicon at ordinary pressure. In addition, at most 50% by volume, or at most 20% by volume, or at most 10% by volume of the first portion of the crucible unit housing is arranged vertically higher than the seed holder unit. Alternatively, at least 50% by volume, in particular at least 80% by volume or 90% by volume of the second housing part of the crucible unit is arranged vertically higher than the seed holder unit. Preferably there is a second crucible volume between the second portion of the crucible unit housing and the seed holder unit. At least 60%, or preferably 80%, or more preferably 90% of the filter assembly is below the condensation temperature Tc. Thus, the thermal conditions of the filter assembly of the filter unit may condense the Si vapor. Thus, the filter assembly can very effectively condense or trap Si.

According to another preferred embodiment of the invention, the filter unit is arranged between a first wall portion of the first part of the housing and a further wall portion of the second part of the housing, the filter body forming a filter outer surface connecting the first wall portion of the first part of the housing and the further wall portion of the second part of the housing, the filter outer surface forming a part of the outer surface of the intersection unit. This embodiment is advantageous because a large filter unit can be used without increasing the amount of material of the crucible housing of the crucible unit.

According to another preferred embodiment of the present invention, the filter outer surface comprises a filter surface covering element. The filter surface covering component is preferably a sealing component, wherein the sealing component is preferably a coating, wherein the coating is preferably manufactured on or attached to or forms the filter surface. The coating preferably consists of a material or a combination of materials which reduces the leakage of sublimated vapors, in particular Si vapors, generated during one operation from the crucible volume through the crucible shell into the furnace volume, in particular by at least 50% by mass, or at least 80% by mass, or at least 90% by mass, or more than 99% by mass, or at least 99.9% by mass, and which is subjected to temperatures above 2000 ℃, in particular at least or at most 3000 ℃ or at most 3500 ℃ or at most 4000 ℃ or at least at most 4000 ℃.

The coating has one or more materials selected from the group of materials comprising at least carbon, especially hot carbon and glassy carbon. Thus, the coating is preferably a glass-carbon coating, or a thermal carbon coating, or a glass-carbon primer and a thermal carbon topcoat, or a thermal carbon primer and a glass-carbon topcoat. Thus, the filter unit, and in particular the outer surface of the filter unit, is preferably coated with hot carbon and/or glassy carbon. The thickness of the thermal carbon layer is preferably more than or up to 10 μm, especially more than or up to 20 μm, or more than or up to 50 μm, or more than or up to 100 μm, or more than or up to 200 μm, or more than or up to 500 μm. The thickness of the glassy carbon layer is preferably more than or up to 10 μm, especially more than or up to 20 μm, or more than or up to 50 μm, or more than or up to 100 μm, or more than or up to 200 μm, or more than or up to 500 μm.

In accordance with another preferred embodiment of the present invention, the filter body forms an inner filter surface. The filter inner surface is preferably arranged coaxially with the filter outer surface. The filter body is preferably annular. The outer filter surface is preferably cylindrical and/or wherein the inner filter surface is preferably cylindrical. The filter outer surface and the filter inner surface extend in a vertical direction. This embodiment is advantageous in that the filter unit may be used for a round crucible unit and/or a crucible unit having a round crucible volume. Thus, the filter unit or the furnace equipment in which the filter unit is located does not need any substantial modification, so that the furnace equipment of the present invention can be manufactured at low cost.

According to a further preferred embodiment of the invention, the filter inner surface comprises a further filter inner surface covering element. The further filter inner surface covering assembly is preferably a sealing assembly, wherein the sealing assembly is preferably a coating. The coating is preferably produced on the filter surface, or attached to the filter surface, or forms the filter surface. The coating preferably has a material or a combination of materials which reduces the leakage of sublimation vapors, in particular Si vapors, generated during one run from the crucible volume through the crucible shell into the furnace volume, in particular by at least 50% by mass, or at least 80% by mass, or at least 90% by mass, or more than 99% by mass, or at least 99.9% by mass.

The coating is preferably resistant to temperatures above 2000 ℃, especially above 2200 ℃ or above 2000 ℃, especially at least or up to 3000 ℃ or at least up to 3000 ℃, or up to 3500 ℃ or at least up to 3500 ℃, or up to 4000 ℃ or at least up to 4000 ℃. The coating is preferably of one or more materials selected from the group of materials comprising at least carbon, especially thermal carbon and glassy carbon. Thus, the filter unit, and in particular the inner surface of the filter unit, is preferably coated with hot carbon and/or glassy carbon. The thickness of the thermal carbon layer is preferably more than or up to 10 μm, especially more than or up to 20 μm, or more than or up to 50 μm, or more than or up to 100 μm, or more than or up to 200 μm, or more than or up to 500 μm. The thickness of the glassy carbon layer is preferably more than or up to 10 μm, especially more than or up to 20 μm, or more than or up to 50 μm, or more than or up to 100 μm, or more than or up to 200 μm, or more than or up to 500 μm.

According to another preferred embodiment of the invention, the filter assembly comprises a filter assembly member, wherein the filter assembly member comprises filter particles and a binder. The filter particles comprise or consist of carbon, wherein the binder holds the filter particles in a fixed relative position to each other. The filter particles are resistant to temperatures above 2000 ℃, in particular at least or up to 3000 ℃ or at least up to 3000 ℃, or up to 3500 ℃ or at least up to 3500 ℃, or up to 4000 ℃ or at least up to 4000 ℃. The adhesive is resistant to temperatures above 2000 ℃, especially at least or up to 3000 ℃ or at least up to 3000 ℃, or up to 3500 ℃ or at least up to 3500 ℃, or up to 4000 ℃ or at least up to 4000 ℃. This embodiment is advantageous in that a filter unit is provided which can withstand the conditions within the crucible unit during operation of the furnace apparatus. In addition, the combination of filter particles and binder forms a substantially larger surface area compared to the outer surface area of the filter unit, in particular at most or at least 10 times larger, or at most or at least 100 times larger, or at most or at least 1000 times larger, or at most or at least 10000 times larger. This embodiment is further advantageous in that the filter unit has the capacity to absorb or capture more than or at most 50% by mass, in particular more than or at most 50% by mass, or more than or at most 70% by mass, or more than or at most 90% by mass, or more than or at most 95% by mass, or more than or at most 99% by mass of the Si vapor generated by the vaporization of the starting material, in particular the starting material required in each case once.

According to another preferred embodiment of the invention, the binder comprises starch or wherein the binder comprises modified starch.

This embodiment is advantageous in that the adhesive is resistant to temperatures above 2000 ℃, in particular above or at most 2000 ℃, in particular at least or at most 3000 ℃ or at least at most 3000 ℃, or at most 3500 ℃ or at least at most 3500 ℃, or at most 4000 ℃ or at least at most 4000 ℃. The binder is jointly resistant to temperatures above 2000 ℃, in particular at least or up to 3000 ℃ or at least up to 3000 ℃, or up to 3500 ℃ or at least up to 3500 ℃, or up to 4000 ℃ or at least up to 4000 ℃.

According to a further preferred embodiment of the invention, the gas inlet is arranged between the receiving space and the seed holder unit, preferably closer to the receiving space than the seed holder unit in the vertical direction, in particular the vertical distance between the seed holder unit and the gas inlet is preferably more than 2 times the vertical distance between the receiving space and the gas inlet, in particular more than 5 times the vertical distance between the receiving space and the gas inlet, or more than 8 times the vertical distance between the receiving space and the gas inlet, or more than 10 times the vertical distance between the receiving space and the gas inlet, or more than 20 times the vertical distance between the receiving space and the gas inlet. This embodiment is advantageous because a flow of gas may be established that causes the vaporized starting material to reach the wafer 18 or the growth front of the crystal uniformly.

According to a further preferred embodiment of the invention, the gas inlet is covered by a gas guiding assembly or a gas distribution assembly. The gas distribution assembly preferably extends parallel to the bottom surface of the crucible unit, and in particular the inner bottom surface of the crucible unit. Additionally or alternatively, the gas distribution assembly extends in a horizontal plane. This embodiment is advantageous in that the introduced gas is evenly distributed to the annular receiving space, thus to the starting material present in the receiving space or to the vaporized starting material flowing out of the receiving space. The vaporized feedstock material is moved by thermally driven diffusion. Additionally or alternatively, the vaporised feedstock material is produced by injection of a gas, in particular Ar and/or N ₂ Is moved by convection of (a).

According to a further preferred embodiment of the invention, the gas distribution assembly is arranged at a defined distance from the bottom surface of the crucible unit, in particular the inner bottom surface of the crucible unit. The defined distance in the vertical direction between the bottom side of the gas distribution assembly and the bottom surface of the crucible unit is preferably less than 0.5x of the vertical distance between the receiving space and the gas inlet (i.e. less than half the vertical distance between the receiving space and the gas inlet), or less than 0.3x of the vertical distance between the receiving space and the gas inlet, or less than 0.1 times the vertical distance between the receiving space and the gas inlet, or less than 0.05x of the vertical distance between the receiving space and the gas inlet.

According to another preferred embodiment of the present invention, the gas distribution assembly is a gas baffle. The gas baffle preferably forms a lower surface and an upper surface. The lower and upper surfaces preferably extend parallel to each other at least in sections. The distance between the lower surface and the upper surface is preferably less than 0.5x of the distance between the receiving space and the gas inlet, or less than 0.3x of the distance between the receiving space and the gas inlet, or less than 0.1x of the distance between the receiving space and the gas inlet, or less than 0.05x of the distance between the receiving space and the gas inlet. This embodiment is advantageous because a substantially thin gas distribution plate may be used. This embodiment is advantageous because the gas distribution plate does not require a large amount of material. In addition, the gas distribution plate does not affect heat radiation radiated from the lower portion covered by the gas distribution plate.

According to another preferred embodiment form of the invention, the means for preventing leakage are pressure units for accumulating a first pressure inside the crucible unit and a second pressure inside the furnace but outside the crucible unit, wherein the second pressure is higher than the first pressure, and wherein the second pressure is lower than 200 torr, in particular lower than 100 torr, or lower than 50 torr, in particular between 0.01 torr and 30 torr. The second pressure is preferably at most 10 torr, or at most 20 torr, or at most 50 torr, or at most 100 torr, or at most 180 torr, higher than the first pressure. This embodiment is advantageous because Si vapor leakage due to the higher pressure surrounding the crucible unit is prevented.

According to another preferred embodiment of the invention, the pipe system is part of the furnace installation. The piping system preferably comprises a first piping or crucible piping connecting the crucible volume to a vacuum unit, and a second piping or furnace piping connecting a furnace section surrounding the crucible unit to the vacuum unit. The vacuum unit preferably has a control assembly for controlling the pressure inside the volume of the crucible and the pressure of the furnace section surrounding the crucible unit. The vacuum unit preferably reduces the pressure inside the crucible volume via the crucible tube or the furnace section surrounding the crucible unit via the furnace tube if the control assembly determines that the pressure inside the crucible volume is above a first threshold value and/or if the control assembly determines that the pressure inside the furnace section surrounding the crucible unit is above a second threshold value. This embodiment is advantageous in that a pressure difference between the pressure inside the crucible volume and the pressure inside the furnace surrounding the crucible volume can be reliably maintained.

In accordance with another preferred embodiment of the present invention, the furnace system includes two or more leak prevention devices selected from the group consisting of leak prevention devices. This embodiment is advantageous in that the furnace apparatus comprises at least the cover element and/or the density increasing element and a filter unit for collecting gaseous Si; or because the furnace apparatus comprises at least the covering element and/or the density increasing element, and a pressure unit for accumulating a first pressure inside the crucible unit, and a second pressure inside the furnace but outside the crucible unit; or because the furnace device comprises at least a pressure unit for accumulating a first pressure inside the crucible unit and a second pressure inside the furnace but outside the crucible unit and the filter unit.

However, the furnace device may also comprise at least the covering element and/or the density increasing element and a filter unit for collecting gaseous Si, and a pressure unit for setting a first pressure inside the crucible unit and a second pressure inside the furnace but outside the crucible unit.

This embodiment is advantageous because the leakage of Si vapor can be prevented in various ways so that it can be installed with the furnace unit of the present invention to meet various needs.

According to a further preferred embodiment of the invention, the heating unit comprises at least one, in particular horizontal, heating element, wherein the heating element is arranged vertically below the receiving space. Thus, the heating element preferably at least partially and preferably mostly or completely overlaps the receiving space. This design is advantageous because the receiving space and the part of the crucible volume or crucible shell enclosed by the receiving space can be heated from below the crucible volume. This is advantageous because for wafers 18 having a small diameter or having a larger diameter, the height of the receiving space is the same as the height of the crucible volume or the part of the crucible housing enclosed by the receiving space. The starting materials can thus be heated homogeneously. The heating unit preferably also has at least one further, in particular vertical, heating element, which is preferably arranged next to the crucible unit, in particular next to the crucible unit side wall surrounding the crucible unit. The heating element and/or the further heating element are preferably arranged inside the furnace insert and outside the crucible unit, in particular outside the crucible volume.

According to a further preferred embodiment of the invention, the receiving space is formed in a wall portion of the crucible unit or is arranged on a wall or bottom portion of the interior of the crucible unit. The receiving space preferably extends around a central axis, which is preferably coaxial with the central axis of the seed holder unit. The receiving space is preferably arranged at a defined distance from the central axis.

According to a further preferred embodiment of the invention a gas pipe or gas guiding means is provided to introduce gas into the crucible unit. The gas pipe or gas guiding means, or a part of the gas pipe or gas guiding means, or a gas inlet to which the gas pipe or gas guiding means is attached, or a part of the gas pipe or gas guiding means is at least partially, and preferably mostly or completely surrounded by the receiving space. The gas pipe or gas guiding means preferably extends at least partially in the direction of the central axis. The gas tube or gas conduction means preferably enters the crucible volume through the bottom portion of the crucible unit or through the bottom portion of the crucible enclosure of the crucible unit. This embodiment is advantageous in that gas may be provided into the crucible volume via a gas line or gas guiding means. Furthermore, since the gas inlet is surrounded by the receiving volume, the gas introduced via the gas inlet can be distributed, in particular uniformly, to different parts of the receiving volume. In this way a mixture of injected gas and vaporized raw material can be produced, in particular in a homogeneous manner.

According to another preferred embodiment of the invention, the receiving space is annular. The receiving space is preferably shaped or formed as a channel, in particular a circular channel, or a plurality of grooves, in particular circular grooves. The plurality of grooves are preferably arranged along a predetermined profile, which is preferably circular in shape. This embodiment is advantageous because the wafer 18 is preferably circular in shape. In this way, the vaporized starting material advantageously reaches the growth surface of the wafer 18 or the growth surface of the growing in-process crystal.

According to a further preferred embodiment of the invention, the defined distance between the receiving space and the central axis is at most 30%, or at most 20%, or at most 10%, or at most 5%, or at most 1% shorter than the diameter of the defined wafer 18. Or the defined distance between the receiving space and the central axis is at most 1%, or at most 5%, or at most 10%, or at most 20%, or at most 30% longer than the diameter of the defined wafer 18. Or the defined distance between the receiving space and the central axis corresponds to the diameter of the defined wafer 18. This embodiment is advantageous because it further supports uniform distribution of vaporized starting material over the growth surface of the wafer 18 or over the growth surface of the growing in-growth crystal.

According to another preferred embodiment of the invention, the receiving space encloses the bottom part of the housing or a part higher than the bottom part of the housing. The bottom section is a solid material section. The height (in the vertical direction) or wall thickness of the solid material section or crucible thick bottom section is preferably greater than 0.3x of the minimum distance of the receiving space from the central axis, or greater than 0.5x of the minimum distance of the receiving space from the central axis, or greater than 0.7x of the minimum distance between the receiving space and the central axis, or greater than 0.9x of the minimum distance between the receiving space and the central axis, or greater than 1.1x of the minimum distance between the receiving space and the central axis, or greater than 1.5x of the minimum distance between the receiving space and the central axis. This design is advantageous because the lower part or the surrounding lower part can be heated by the heating unit. If the lower portion is heated, it heats the spaces between the wafers 18 as well as the wafers 18. If the lower portion is heated, it heats the spaces between the wafers 18 as well as the wafers 18. Because the lower portion is preferably a solid mass of material and/or a crucible-shaped solid bottom section, heating of the space between the wafer 18 and the bottom section, and heating of the wafer 18 or the waxy surface of the growing crystal is carried out in a uniform manner. The bottom portion preferably has an outer surface portion, preferably a surface portion of the crucible body, and an inner surface portion, preferably parallel to the outer surface portion. This is advantageous because the bottom portion can be heated uniformly. The inner surface portion of the bottom portion is preferably a flat surface, wherein the flat surface is preferably arranged in a horizontal plane. The inner surface portion is preferably arranged parallel to the surface of the wafer 18. This embodiment is advantageous because the space between the wafer 18 and the bottom part, and the growth surface of the wafer 18 and/or the growing crystals can be heated uniformly.

The bottom portion thus has an inner surface which is disposed within the crucible volume and preferably parallel to the seed holder unit. The center of the inner surface and the center of the seed holder unit are preferably arranged on the same vertical axis, wherein the distance between the inner surfaces of the bottom sections is preferably arranged at a defined distance from the seed holder unit. The distance is preferably 0.5x greater than the minimum distance between the receiving space and the central axis, or 0.7x greater than the minimum distance between the receiving space and the central axis, or 0.8x greater than the minimum distance between the receiving space and the central axis, or 1x greater than the minimum distance between the receiving space and the central axis, or 1.2x greater than the minimum distance between the receiving space and the central axis, or 1.5x greater than the minimum distance between the receiving space and the central axis, or 2x greater than the minimum distance between the receiving space and the central axis, or 2.5x greater than the minimum distance between the receiving space and the central axis. This embodiment is advantageous because large (wide and/or long) crystals can be grown.

The filter unit is arranged perpendicularly above the receiving chamber. This embodiment is advantageous in that the filter unit is preferably arranged in the gas flow path, as the vaporized raw material and/or injected gas flows from the lower crucible section to the upper crucible section.

According to another preferred embodiment of the invention, the filter unit and the receiving space are preferably arranged coaxially. This embodiment is advantageous because the vaporisation starting material and/or the introduced gas, or the mixture of vaporisation starting material and introduced gas, may be uniform through a preferably cylindrical side wall (sei-den wall). In this way, the accumulation of vaporized starting material and/or introduced gas can be inflated beforehand. This embodiment is advantageous because it allows for a uniform growth of crystals. Uniform growth preferably means that the growth rate over the entire surface portion of the crystalline growth region is within a defined range and/or that the accumulation of defects and/or doping is uniformly distributed, the term "uniform distribution" defining a permissible deviation range.

According to a further preferred embodiment of the invention, the outer diameter of the filter unit corresponds to the outer diameter of the receiving space and/or wherein the inner diameter of the filter unit preferably corresponds to the inner diameter of the receiving space. This embodiment is advantageous because the shape of the housing does not cause any significant complexity, thus allowing for low cost manufacturing. The outer diameter of the filter unit is preferably at least or at most 1.05x larger than the outer diameter of the receiving space, or wherein the outer diameter of the filter unit is preferably at least or at most 1.1x larger than the outer diameter of the receiving space, or wherein the outer diameter of the filter unit is preferably at least or at most 1.3x larger than the outer diameter of the receiving space, or wherein the outer diameter of the filter unit is preferably at least or at most 1.5x larger than the outer diameter of the receiving space. Or the outer diameter of the receiving space is preferably at least or at most 1.05x larger than the outer diameter of the filter unit, or wherein the outer diameter of the receiving space is preferably at least or at most 1.1x larger than the outer diameter of the filter unit, or wherein the outer diameter of the receiving space is preferably at least or at most 1.3x larger than the outer diameter of the filter unit, or wherein the outer diameter of the receiving space is preferably at least or at most 1.5x larger than the outer diameter of the filter unit. Additionally or alternatively, the inner diameter of the receiving space is preferably at least or at most 1.05x larger than the inner diameter of the filter unit, or wherein the inner diameter of the receiving space is preferably at least or at most 1.1x larger, or wherein the inner diameter of the receiving space is preferably at least or at most 1.3x larger than the inner diameter of the filter unit, or wherein the inner diameter of the receiving space is preferably at least or at most 1.5x larger than the inner diameter of the filter unit. Or the inner diameter of the filter unit is preferably at least or at most 1.05x larger than the inner diameter of the receiving space, or wherein the inner diameter of the filter unit is preferably at least or at most 1.1x larger than the inner diameter of the receiving space, or wherein the inner diameter of the filter unit is preferably at least or at most 1.3x larger than the inner diameter of the receiving space, or wherein the inner diameter of the filter unit is preferably at least or at most 1.5x larger than the inner diameter of the receiving space.

According to another preferred embodiment of the present invention, a growth guide assembly is arranged or provided in a vertical direction above the receiving space to guide the vaporized starting material and/or introduced gas into the space between the seed holder unit and the inner bottom surface of the crucible unit. This embodiment is advantageous because the growth guide assembly preferably performs a number of functions. In one aspect, the growth guide assembly guides vaporized starting material to the wafer 18 or to the growing crystal. On the other hand, the growth guide assembly affects the shape of the growing crystals by limiting its radial expansion.

According to another preferred embodiment of the present invention, the growth guide assembly comprises a first wall section or first growth guide section, and a second wall section or second growth guide section. The first growth guide section is preferably shaped to match a corresponding wall section of the crucible housing. Preferably, matching means in this context that the wall portion of the crucible housing and the growth guide member are preferably coupled by a shell-and/or crimp connection. The second portion of the growth guide is preferably shaped to manipulate the shape of the growing crystal. According to another preferred embodiment of the present invention, the first portion of the growth guide and the second portion of the growth guide are coaxially aligned. The first segment growth guide is arranged at a first diameter relative to the central shaft, and wherein the second segment growth guide is arranged at a second diameter relative to the central shaft, the first diameter being larger than the second diameter. The first growth guide section and the second growth guide section are connected with each other through a third wall section and a third growth guide section respectively, and the third growth guide section extends at least partially in a horizontal direction. The first and third growth guide segments form an arc-shaped segment and a fourth growth guide segment, respectively, and/or wherein the second and third growth guide segments are arranged at an angle between 60 ° and 120 °, in particular at an angle between 70 ° and 110 °, in particular at an angle of 90 °. The fourth growth guide section may have, for example, a convex shape or a concave shape or a conical shape. The first wall section, the second section growth aid, and the third section growth aid are preferably integral parts of the growth aid. Preferably the growth aid is made of graphite. This embodiment is advantageous because the growth guide assembly has a simple but efficient shape. Thus, the growth guide assembly may be manufactured in a cost-effective manner.

According to another preferred embodiment of the invention, the outer diameter of the filter unit is at least or at most 1.05x larger than the first diameter of the growth guide assembly, or wherein the outer diameter of the filter unit is preferably at least or at most 1.1x larger than the first diameter of the growth guide assembly, or wherein the outer diameter of the filter unit is preferably at least or at most 1.3x larger than the first diameter of the growth guide, or wherein the outer diameter of the filter unit is preferably at least or at most 1.5x larger than the first diameter of the growth guide; and/or wherein the second outer diameter of the growth guide is preferably at least or at most 1.05x larger than the inner diameter of the filter unit, or wherein the second outer diameter of the growth guide is preferably at least or at most 1.1x larger than the inner diameter of the filter unit, or wherein the second outer diameter of the growth guide is preferably at least or at most 1.3x larger than the inner diameter of the filter unit, or wherein the second outer diameter of the growth guide is preferably at least or at most 1.5x larger than the inner diameter of the filter unit.

Wherein the upper vertical end of the growth guide of the second stage growth guide forms a gas flow channel with the seed holding unit, wherein a minimum distance between the upper vertical end of the growth guide of the second stage growth guide and the seed holding unit is less than 0.3x of the second diameter of the growth guide, or less than 0.1x of the second diameter of the growth guide, or less than 0.08x of the second diameter of the growth guide, or less than 0.05x of the second diameter of the growth guide, or less than 0.03x of the second diameter of the growth guide, or less than 0.01x of the second diameter of the growth guide.

According to a further preferred embodiment of the invention, the coating is preferably applied to the receiving space, in particular to the surface of the receiving space within the crucible volume and/or to the growth guide element or growth guide plate or gas distribution plate. The coating preferably has a reduced permeability of Si vapor to 10 through the wall portion adjoining the receiving space and/or through the wall portion adjoining the growth guide member ^-3 m ² /s, or preferably 10 ^-11 m ² /s, or more preferably 10 ^-12 m ² Materials or material combinations of/s.

The coating preferably withstands temperatures above 2000 ℃, in particular at least or up to 3000 ℃ or at least up to 3000 ℃, or up to 3500 ℃ or at least up to 3500 ℃, or up to 4000 ℃ or at least up to 4000 ℃. This embodiment is advantageous because the modified containment and/or growth guide assembly has at least two layers of material, one layer forming the structure of the containment and/or growth guide assembly and the other layer reducing or excluding the penetration of Si vapor. Most preferably the coating has one or more materials selected from the group of materials comprising at least carbon, especially hot carbon and glassy carbon. Thus, the receiving space and/or growth directing component is preferably coated with hot carbon and/or vitreous carbon. The thickness of the layer of hot carbon is preferably more than or up to 10 μm, especially more than or up to 20 μm, or more than or up to 50 μm, or more than or up to 100 μm, or more than or up to 200 μm, or more than or up to 500 μm. The thickness of the glassy carbon layer is preferably more than or up to 10 μm, especially more than or up to 20 μm, or more than or up to 50 μm, or more than or up to 100 μm, or more than or up to 200 μm, or more than or up to 500 μm. According to a further preferred embodiment of the invention, the coating is produced by chemical vapor deposition or wherein the coating is produced by brushing, in particular on a precursor material, in particular phenol formaldehyde, and pyrolysed after brushing. This embodiment is advantageous in that the coating can be produced in a reliable manner.

According to another preferred embodiment of the present invention, the heating unit comprises at least one heating element. The heating element is preferably arranged perpendicularly below the receiving space and/or perpendicularly below the bottom portion of the crucible unit, which is surrounded by the receiving space. This design is advantageous because the receiving space and/or the bottom section enclosed by the receiving space can be heated by the heating element. The heating element preferably at least partially and preferably more than 50%, or more than 70%, or at most 90%, or completely overlaps the receiving space and/or the bottom section surrounded by the receiving space. This design is advantageous because a uniform temperature distribution can be set, in particular a uniform temperature level can be produced.

According to a further preferred embodiment of the invention, the furnace apparatus comprises a gas flow unit. The gas flow cell preferably has a gas inlet for conducting gas into the crucible cell or into the crucible volume, and a gas outlet for withdrawing gas from the crucible cell or from the crucible volume. The gas inlet is preferably arranged closer to the bottom of the crucible unit than the gas outlet. The gas inlet and gas outlet are preferably arranged within the crucible volume. This design is advantageous because conditions within the volume of the crucible and/or vapor composition and/or liquid flow (direction and/or velocity) within the crucible can be affected or controlled.

According to another preferred embodiment of the invention, the gas outlet comprises a gas carrying means, in particular a tube. The gas outlet preferably has a sensor, in particular a temperature and/or pressure sensor, which is preferably arranged inside the conducting means, in particular the tube, or is part of the conducting means, in particular the tube, or is attached to the conducting means, in particular the outer wall of the tube. This embodiment is advantageous because temperature and/or pressure conditions may be monitored.

Additionally or alternatively, according to a further preferred embodiment of the invention, the gas inlet comprises gas conducting means, in particular a pipe. The gas inlet preferably has a sensor, in particular a temperature and/or pressure sensor, which is preferably arranged inside the conduit means, in particular the tube, or is part of the conduit means, in particular the tube, or is attached to the outer wall of the conduit means, in particular the tube. This embodiment is advantageous because temperature and/or pressure conditions may be monitored.

According to a further preferred embodiment of the invention, the sensor in the gas inlet and/or the gas outlet is a pyrometer. This embodiment is advantageous because the pyrometer can withstand high temperatures. This embodiment is advantageous because the pyrometer may be used multiple times, making it a very cost effective solution.

According to another preferred embodiment of the invention, the sensors in the gas inlet and/or the gas outlet are connected to a control unit. This embodiment is advantageous in that the control unit receives sensor signals or sensor data. Thus, the control unit may output conditions within the crucible unit, such as, inter alia, a time stamp function, to an operator to monitor the manufacturing or growth process. Additionally or alternatively, the control unit may have control rules to control oven apparatus in accordance with the control rules, time and/or sensor output.

According to another preferred embodiment of the invention, the receiving space is formed by one or at least one continuous channel or a plurality of grooves. The channel or groove preferably at least partially and preferably substantially or preferably completely encloses a surface arranged or provided or present inside the crucible unit, in particular an inner surface of a wall and/or bottom section of the crucible unit, wherein the receiving space is preferably annular. The heating element preferably covers at least 30%, or at least 40%, or at least 50%, or at least 60%, or at least 70%, or at least 80%, or at least 90%, or at least 95% of the bottom surface of the receiving space, and at least 20%, or at least 30%, or at least 40%, or at least 50%, or at least 60%, or at least 70%, or at least 80%, or at least 90%, or at least 95% of the surface is at least partially surrounded by the receiving space. The region at least partially surrounded by the receiving space preferably belongs to a solid wall or a crucible bottom section, respectively, which extends in the vertical direction at least over a distance V1, wherein in the receiving space a distance V2 extends in the vertical direction between the bottom surface of the receiving space and the top surface of the lowest side wall portion of the receiving space, wherein V2> V1 (i.e. the distance V2 is larger in the vertical direction, i.e. the distance V2 is larger compared to the distance V1), in particular V2>1.1xv1, or V2>1.2xv1, or V2>1.5xv1, or V2>2xv1, or v2=v1, or V2< V1, in particular V2<1.1xv1, or V2<1.5xv1, or V2<2xv1.

The receiving space thus preferably encloses the lower part of the housing and in particular has a surface surrounded by the receiving space. The bottom portion is preferably a solid material portion. The height (vertical direction) of the bottom portion of the solid crucible is preferably greater than 0.3x of the minimum distance between the receiving space and the central axis, or greater than 0.5x of the minimum distance between the receiving space and the central axis, or greater than 0.7x of the minimum distance between the receiving space and the central axis, or greater than 0.9x of the minimum distance between the receiving space and the central axis, or greater than 1.1x of the minimum distance between the receiving space and the central axis, or greater than 1.5x of the minimum distance between the receiving space and the central axis.

According to another preferred embodiment of the invention, the bottom part has an inner surface or a surface surrounded by the receiving space. The inner surface of the bottom portion is arranged within the crucible volume, and preferably parallel to the seed holder unit. The center of the inner surface is preferably arranged on the same vertical axis as the center of the seed holder and/or the center of the wafer 18 held by the seed holder unit. The lower inner surface is preferably arranged at a defined distance from the seed holder unit. The distance is preferably 0.5x greater than the minimum distance between the receiving space and the central axis, or 0.7x greater than the minimum distance between the receiving space and the central axis, or 0.8x greater than the minimum distance between the receiving space and the central axis, or 1x greater than the minimum distance between the receiving space and the central axis, or 1.2x greater than the minimum distance between the receiving space and the central axis, or 1.5x greater than the minimum distance between the receiving space and the central axis, or 2x greater than the minimum distance between the receiving space and the central axis, or 2.5x greater than the minimum distance between the receiving space and the central axis. This embodiment is advantageous because the crucible volume is at least in sections and preferably predominantly or entirely rotationally symmetrical in shape, which supports uniform distribution of vaporized starting material over the wafer 18 or growing crystal.

According to a further preferred embodiment of the invention, the area enclosed by the receiving space has a size of at least 0.5x of the size of the top surface of the defined wafer 18, or a size of at least 0.8x of the size of the top surface of the defined wafer 18, or a size of at least 0.9x of the size of the top surface of the defined wafer 18, or a size of at least 1x of the size of the top surface of the defined wafer 18, or a size of at least 1.1x of the size of the top surface of the defined wafer 18. Additionally or alternatively, the center of the surface surrounded by the receiving space and the center of the top surface of the defined wafer 18 are preferably disposed on the same vertical axis. Additionally or alternatively, the surface surrounded by the receiving space and the upper surface of the defined wafer 18 are preferably arranged parallel to each other. This embodiment is advantageous in that the heat distribution can be carried out uniformly over the surface enclosed by the receiving space.

According to another preferred embodiment of the invention a control unit is provided for controlling the degree of pressure in the crucible unit and/or furnace and/or for controlling the flow of gas into the crucible unit and/or for controlling the heating unit. The heating unit is preferably controlled to produce an isothermal profile parallel to the support unit or orthogonal to the vertical or horizontal. This embodiment is advantageous because the control unit may use predefined rules and/or sensor data or sensor signals to monitor the growth process and alter one or more of the operating parameters of the above-described units to control crystal growth.

According to another preferred embodiment of the present invention, a filter unit is provided. The filter unit preferably surrounds the seed holder unit and/or wherein the filter unit is preferably arranged at least partly above the seed holder unit, in particular at least 60% by volume of the filter unit is arranged above the seed holder unit. The filter unit comprises a filter body, wherein the filter body comprises a filter input surface for introducing a gas containing Si vapor into the filter body, and an output surface for discharging the filtered gas, wherein the filter input surface is preferably arranged with a vertical height below the height of the output surface. At least one or exactly one filter assembly is arranged between the filter input surface and the output surface. The filter assembly may form a filter input surface and/or an output surface. Preferably the filter assembly forms a separation zone for adsorbing and condensing Si vapor. This design is advantageous because Si vapor can be trapped inside the filter assembly, thus reducing defects caused by Si vapor. Preferably the separation zone has at least or at most 50% by volume of the filter element volume, or at least or at most 80% by volume of the filter element volume, or at least or at most 90% by volume of the filter element volume. Thus, 1% to 50% by volume, or 10% to 50% by volume, or 1% to 30% by volume of the filter assembly may be a vapor segment, or a segment in which the vaporized feedstock is in a vapor configuration.

In accordance with another preferred embodiment of the present invention, the filter assembly forms a gas flow path from the filter input surface to the output surface. The filter assembly preferably has a height S1 and the length of the gas flow path through the filter assembly is S2, wherein S2 is at least 10 times longer than S1, especially S2 is 100 times longer than S1, or S2 is 1000 times longer than S1. This design is advantageous because the filter assembly has a capacity sufficient to absorb all Si vapors generated during flow or during growth of crystals, especially SiC crystals. Thus, the filter assembly preferably forms a porous, large surface area for trapping Si sublimation vapors during PVT growth, particularly SiC single crystal growth. The filter assembly preferably has a surface area of at least 100m ² /g or at least 1000m ² Material/g.

According to another preferred embodiment of the invention, the filter unit is arranged between the first part of the crucible unit housing and the second part of the crucible unit housing. At least 50% by volume, in particular at least 80% by volume or 90% by volume of the first housing part of the crucible unit is arranged in a vertical direction below the seed holder unit. A first crucible volume is provided between the first housing portion of the crucible unit and the seed holder, wherein the first crucible volume is operable such that at least 80%, or preferably 90%, or even more preferably 100% of the first crucible volume is above the condensation temperature Tc of silicon at ordinary pressure. In addition, at most 50% by volume, or at most 20% by volume, or at most 10% by volume of the first portion of the crucible unit housing is arranged vertically higher than the seed holder unit. Alternatively, at least 50% by volume, in particular at least 80% by volume or 90% by volume of the second housing part of the crucible unit is arranged vertically higher than the seed holder unit. Preferably a second crucible volume is provided between the second housing part of the crucible unit and the seed holder. At least 60%, or preferably 80%, or more preferably 90% of the filter assembly is below the condensation temperature Tc. This embodiment is advantageous because the output material is vaporized or vaporized at or above Tc and condensed at or below Tc. Thus, the fact that Si vapor condenses below a certain temperature can be used to trap condensed Si in the filter assembly. Thus, the filter assembly is very efficient.

According to another preferred embodiment of the invention, the filter unit is arranged between the first wall portion of the first housing portion and the further wall portion of the second housing portion. The filter body preferably forms the filter outer surface. The filter outer surface is preferably a further wall portion connecting the first wall portion of the first housing portion with the second housing portion. The filter outer surface preferably forms a portion of the outer surface of the crucible unit. This embodiment is advantageous in that arranging the filter unit increases the volume of the crucible unit without requiring one or more additional crucible housing parts.

According to another preferred embodiment of the present invention, the filter outer surface comprises a filter outer surface covering assembly. The filter outer surface covering assembly is preferably a sealing assembly. The seal assembly is preferably a coating. The coating is preferably produced on the filter surface, or attached to the filter surface, or forms the filter surface. The coating preferably has a material or a combination of materials which reduces the leakage of sublimated vapors, in particular Si vapors, generated during one operation from the crucible volume through the crucible shell into the furnace volume, in particular by at least 50% by mass, or at least 80% by mass, or at least 90% by mass, or more than 99% by mass, or at least 99.9% by mass.

The coating preferably withstands temperatures above 2000 ℃, in particular at least or up to 3000 ℃ or at least up to 3000 ℃, or up to 3500 ℃ or at least up to 3500 ℃, or up to 4000 ℃ or at least up to 4000 ℃. The coating preferably comprises one or more materials selected from the group of materials comprising at least carbon, especially hot carbon and glassy carbon. This embodiment is advantageous in that the filter unit may also form an outer barrier of the crucible unit. Thus, the filter unit preferably absorbs or traps Si and preferably also prevents Si vapor from escaping. The ash content of the filter assembly is preferably less than 5% by mass or less than 1% by mass. Which means that less than 5% or less than 1% of the mass of the filter assembly is ash.

In accordance with another preferred embodiment of the present invention, the filter body forms an inner filter surface. The filter inner surface is preferably coaxial with the filter outer surface. The filter body is preferably annular. The filter outer surface is preferably cylindrical and/or the filter inner surface is preferably cylindrical. The filter outer surface and/or the filter inner surface has the longest extension in the vertical direction or in the circumferential direction. This embodiment is advantageous in that the filter unit can be arranged in a simple manner due to its shape. Additionally or alternatively, the filter inner surface encloses a space above the seed holder unit. The space surrounded by the seed holder unit may serve as a cooling space for cooling the filter assembly and/or for cooling the seed holder unit. It may provide a cooling unit, wherein the cooling unit is preferably at least one cooling tube for guiding a cooling liquid. This cooling tube may be arranged to at least partly or at least mainly (over 50% in circumferential direction) surround or completely surround the crucible unit. Additionally or alternatively, the cooling tube may be arranged inside the crucible volume, in particular in the space enclosed by the filter inner surface. However, the cooling tube may also extend from outside the crucible unit through the wall of the crucible unit and/or the wall of the filter unit into the crucible volume, in particular into the space enclosed by the inner surface of the filter. In addition, the cooling tube may extend outside the furnace. This embodiment is advantageous in that the temperature inside the crucible unit can be advantageously controlled. In addition, the temperature profile in the crucible volume can be set to a much steeper gradient than in the case without the cooling unit.

In accordance with a further preferred embodiment of the present invention the filter inner surface has a further filter inner surface covering element. The further filter inner surface covering assembly is preferably a sealing assembly. The seal assembly is preferably a coating, wherein the coating is preferably fabricated on, attached to, or formed on the filter surface. The coating preferably has a material or a combination of materials which blocks leakage of sublimation vapors, in particular Si vapors, generated during one run, from the crucible volume back into the furnace volume through the crucible shell, in particular at least 50% by mass, or at least 80% by mass, or at least 90% by mass, or more than 99% by mass, or at least 99.9% by mass.

The coating preferably withstands temperatures above 2000 ℃, in particular at least or up to 3000 ℃ or at least up to 3000 ℃, or up to 3500 ℃ or at least up to 3500 ℃, up to 4000 ℃ or at least up to 4000 ℃. The coating is preferably a material having one or more materials selected from the group consisting of at least carbon, especially thermal carbon and glassy carbon. This solution is advantageous because Si vapor is prevented from leaking into the space enclosed by the inner surface of the filter.

The filter assembly preferably consists of: activated carbon blocks and/or one or more, especially different, graphite foam bodies, including those made from carbonized particles and/or rigid graphite insulators and/or flexible graphite insulators.

In accordance with another preferred embodiment of the present invention, the filter assembly includes a filter assembly member. The filter assembly preferably comprises filter particles and a binder. The filter particles preferably comprise or consist of carbon. The binder preferably holds the filter particles in a fixed relative position to each other. The filter particles are preferably subjected to temperatures above 2000 ℃, in particular at least or up to 3000 ℃ or at least up to 3000 ℃, or up to 3500 ℃ or at least up to 3500 ℃, or up to 4000 ℃ or at least up to 4000 ℃. The filter particles are preferably resistant to temperatures above 2000 ℃, especially at least or up to 3000 ℃ or at least up to 3000 ℃, or up to 3500 ℃, or at least up to 4000 ℃. The filter particles are preferably subjected to temperatures above 1700 ℃, especially above 2000 ℃, especially up to or above 2000 ℃, especially at least or up to 3000 ℃ or at least up to 3000 ℃, or up to 3500 ℃ or at least up to 3500 ℃, or up to 4000 ℃ or at least up to 4000 ℃. This solution is advantageous because the solid filter assembly is free of toxic materials. In addition, the solid filter assembly can be manufactured at low cost. The filter unit, in particular the filter assembly, is preferably a disposable unit or assembly.

According to a further preferred embodiment of the invention, the binder comprises starch or wherein the binder comprises starch.

According to a further preferred embodiment of the invention, the furnace system comprises a gas flow unit. The gas flow unit preferably has a gas inlet for conducting gas into the crucible unit, and a gas outlet for discharging gas from the crucible unit into the furnace or through the furnace to the outside of the furnace. The gas inlet is preferably arranged upstream of the gas flow direction of the filter unit, in particular upstream of the gas flow direction of the receiving space, and wherein the gas outlet is arranged downstream of the gas flow direction of the filter unit. Thus, the gas inlet is preferably arranged in a transition zone within the crucible unit. The transition zone preferably also includes a seed holder unit and a receiving space. The starting material may be converted from a solid configuration to a vapor configuration, and from the vapor configuration to a solid target. The starting material may be disposed within the receiving space, and the solid target may be held by the seed holder unit. The solid target is crystalline, especially SiC. The gas introduced through the gas inlet is preferably mixed and/or reacted with the starting material of the steam configuration and/or during solidification. The gas outlet is preferably arranged in a trap zone, wherein the trap zone also comprises the outlet surface of the filter unit, wherein the gas composition in the trap zone is preferably purged of Si vapor or Si-free vapor. The temperature in the trapping region is preferably below the solidification temperature of the gaseous Si or Si vapor. This embodiment is advantageous because the crystal growth process can be manipulated. For example, it may add one or more gases to dope the crystals. Additionally or alternatively, it may modify, in particular accelerate, the transport of the vapor from the receiving space to the wafer 18 or crystallization. Uniform growth preferably means that the growth rate over the entire surface portion of the crystalline growth region is within a defined range and/or that the accumulation of defects and/or doping is uniformly distributed, the term "uniform distribution" defining a permissible deviation range.

According to a further preferred embodiment of the invention, the outer diameter of the filter unit corresponds to the outer diameter of the receiving space and/or wherein the inner diameter of the filter unit preferably corresponds to the inner diameter of the receiving space. This embodiment is advantageous because the shape of the housing does not cause any significant complexity, thus allowing for low cost manufacturing. The outer diameter of the filter unit is preferably at least or at most 1.05x larger than the outer diameter of the receiving chamber, or wherein the outer diameter of the filter unit is preferably at least or at most 1.1x larger than the outer diameter of the receiving space, or wherein the outer diameter of the filter unit is preferably at least or at most 1.3x larger than the outer diameter of the receiving space, or wherein the outer diameter of the filter unit is preferably at least or at most 1.5x larger than the outer diameter of the receiving space. Or the outer diameter of the receiving space is preferably at least or at most 1.05x larger than the outer diameter of the filter unit, or wherein the outer diameter of the receiving space is preferably at least or at most 1.1x larger than the outer diameter of the filter unit, or wherein the outer diameter of the receiving space is preferably at least or at most 1.3x larger than the outer diameter of the filter unit, or wherein the outer diameter of the receiving space is preferably at least or at most 1.5x larger than the outer diameter of the filter unit. Additionally or alternatively, the inner diameter of the receiving space is preferably at least or at most 1.05x larger than the inner diameter of the filter unit, or wherein the inner diameter of the receiving space is preferably at least or at most 1.1x larger, or wherein the inner diameter of the receiving space is preferably at least or at most 1.3x larger than the inner diameter of the filter unit, or wherein the inner diameter of the receiving space is preferably at least or at most 1.5x larger than the inner diameter of the filter unit. Or the inner diameter of the filter unit is preferably at least or at most 1.05x larger than the inner diameter of the receiving space, or wherein the inner diameter of the filter unit is preferably at least or at most 1.1x larger than the inner diameter of the receiving space, or wherein the inner diameter of the filter unit is preferably at least or at most 1.3x larger than the inner diameter of the receiving space, or wherein the inner diameter of the filter unit is preferably at least or at most 1.5x larger than the inner diameter of the receiving space.

According to another preferred embodiment of the present invention, a growth guiding member is arranged or provided over the receiving space perpendicularly to guide the vaporized starting material and/or introduced gas into the space between the seed holder unit and the inner bottom surface of the crucible unit. This embodiment is advantageous because the growth guide assembly preferably performs a number of functions. In one aspect, the growth guide assembly guides vaporized starting material to the wafer 18 or to the growing crystal. On the other hand, the growth guide assembly affects the shape of the growing crystal by limiting its radial direction.

Wherein the upper vertical end of the growth guide of the second segment forms a gas flow channel with the seed holder unit, wherein a minimum distance between the upper vertical end of the growth guide of the second segment and the seed holder unit is less than 0.3x of the second diameter of the growth guide, or less than 0.1x of the second diameter of the growth guide, or less than 0.08x of the second diameter of the growth guide, or less than 0.05x of the second diameter of the growth guide, or less than 0.03x of the second diameter of the growth guide, or less than 0.01x of the second diameter of the growth guide.

According to another preferred embodiment of the invention, the bottom part has an inner surface or a surface surrounded by the receiving space. The inner surface of the bottom portion is arranged within the crucible volume, and preferably parallel to the seed holder unit. The center of the inner surface is preferably arranged on the same vertical axis as the center of the seed holder and/or the center of the wafer 18 held by the seed holder unit. The lower inner surface is preferably arranged at a defined distance from the seed holder unit. The distance is preferably 0.5x greater than the minimum distance between the receiving space and the central axis, or 0.7x greater than the minimum distance between the receiving space and the central axis, or 0.8x greater than the minimum distance between the receiving space and the central axis, or 1x greater than the minimum distance between the receiving space and the central axis, or 1.2x greater than the minimum distance between the receiving space and the central axis, or 1.5x greater than the minimum distance between the receiving space and the central axis, or 2x greater than the minimum distance between the receiving space and the central axis, or 2.5x greater than the minimum distance between the receiving space and the central axis. The shape of this embodiment is advantageous because the crucible volume is at least in sections and preferably predominantly or entirely rotationally symmetric in shape, which supports uniform distribution of vaporized starting material over the wafer 18 or growing crystal.

According to another preferred embodiment of the invention, the area enclosed by the receiving space is at least 0.5x in size of the top surface of the defined wafer 18, or at least 0.8x in size of the top surface of the defined wafer 18, or at least 0.9x in size of the top surface of the defined wafer 18, or at least 1x in size of the top surface of the defined wafer 18, or at least 1.1x in size of the top surface of the defined wafer 18. Additionally or alternatively, the center of the surface surrounded by the receiving space and the center of the top surface of the defined wafer 18 are preferably disposed on the same vertical axis. Additionally or alternatively, the surface surrounded by the receiving space and the upper surface of the defined wafer 18 are preferably arranged parallel to each other. This embodiment is advantageous in that the heat distribution can be carried out uniformly over the surface enclosed by the receiving space.

According to another preferred embodiment of the present invention, a filter unit is provided. The filter unit preferably surrounds the seed holder unit and/or wherein the filter unit is preferably arranged at least partly above the seed holder unit, in particular at least 60% by volume of the filter unit is arranged above the seed holder unit. The filter unit comprises a filter body, wherein the filter body comprises a filter input surface for introducing a gas containing Si vapor into the filter body, and an output surface for discharging the filtered gas, wherein the filter input surface is preferably arranged with a vertical height below the height of the output surface. At least one or exactly one filter assembly is arranged between the filter input surface and the output surface. The filter assembly may form a filter input surface and/or an output surface. Preferably the filter assembly forms a separation zone for adsorbing and condensing Si vapor. This design is advantageous because Si vapor can be trapped inside the filter assembly, thus reducing defects caused by Si vapor. The capture zone preferably has at least or at most 50% by volume of the filter element volume, or at least or at most 80% by volume of the filter element volume, or at least or at most 90% by volume of the filter element volume. Thus, 1% to 50% by volume, or 10% to 50% by volume, or 1% to 30% by volume of the filter element volume may be a vapor segment, or a segment in which the vaporized starting material is in a vapor configuration.

According to another preferred embodiment of the invention, the filter unit is arranged between the first part of the crucible unit housing and the second part of the crucible unit housing. At least 50% by volume, in particular at least 80% by volume or 90% by volume of the first housing part of the crucible unit is arranged in a vertical direction below the seed holder unit. A first crucible volume is provided between the first housing portion of the crucible unit and the seed holder unit, wherein the first crucible volume is operable such that at least 80%, or preferably 90%, or more preferably 100% of the first crucible volume is above the condensation temperature Tc of silicon at ordinary pressure. In addition, at most 50% by volume, or at most 20% by volume, or at most 10% by volume of the first portion of the crucible unit housing is disposed vertically above the seed holder unit. Alternatively, at least 50% by volume, in particular at least 80% by volume or 90% by volume of the second housing part of the crucible unit is arranged vertically higher than the seed holder unit. Preferably a second crucible volume is provided between the second housing part of the crucible unit and the seed holder unit. At least 60%, or preferably 80%, or more preferably 90% of the filter assembly is below the condensation temperature Tc. This embodiment is advantageous because the starting material is vaporized or vaporized at or above Tc and condensed at or below Tc. Thus, the fact that Si vapor condenses below a certain temperature can be used to trap condensed Si in the filter assembly. Thus, the filter assembly is very efficient.

In accordance with another preferred embodiment of the present invention, the filter body forms an inner filter surface. The filter inner surface is preferably coaxial with the filter outer surface. The filter body is preferably annular. The filter outer surface is preferably cylindrical and/or the filter inner surface is preferably cylindrical. The filter outer surface and/or the filter inner surface has the longest extension in the vertical direction or in the circumferential direction. This embodiment is advantageous in that the filter unit can be arranged in a simple manner due to its shape. Additionally or alternatively, the filter inner surface encloses a space above the seed holder unit. The space surrounded by the seed holder unit may serve as a cooling space for cooling the filter assembly and/or for cooling the seed holder unit. It may provide a cooling unit, wherein the cooling unit is preferably at least one cooling tube for guiding a cooling liquid. This cooling tube may be arranged to at least partly or at least mainly (over 50% in circumferential direction) surround or completely surround the crucible unit. Additionally or alternatively, the cooling tube may be arranged within the crucible volume, in particular in a space enclosed by the filter inner surface. However, the cooling tube may also extend from outside the crucible unit through the wall of the crucible unit and/or the wall of the filter unit into the crucible volume, in particular into the space enclosed by the inner surface of the filter. In addition, the cooling tube may extend outside the furnace. This embodiment is advantageous in that the temperature inside the crucible unit can be advantageously controlled. In addition, the temperature profile in the crucible volume can be set to a much steeper gradient than in the case without the cooling unit.

The coating preferably withstands temperatures above 2000 ℃, in particular at least or up to 3000 ℃ or at least up to 3000 ℃, or up to 3500 ℃ or at least up to 3500 ℃, or up to 4000 ℃ or at least up to 4000 ℃. The coating is preferably of one or more materials selected from the group of materials comprising at least carbon, especially thermal carbon and glassy carbon. This solution is advantageous because it prevents Si vapor from leaking into the space enclosed by the inner surface of the filter.

The filter element preferably comprises activated carbon blocks and/or one or more, especially different, graphite foam bodies, including those made of carbonized particles and/or rigid graphite insulation and/or flexible graphite insulation.

According to a further preferred embodiment of the invention, the furnace system comprises a gas flow unit. The gas flow unit preferably has a gas inlet for conducting gas into the crucible unit, and a gas outlet for discharging gas from the crucible unit into the furnace or through the furnace to the outside of the furnace. The gas inlet is preferably arranged upstream of the gas flow direction of the filter unit, in particular upstream of the gas flow direction of the receiving space, and wherein the gas outlet is arranged downstream of the gas flow direction of the filter unit. Thus, the gas inlet is preferably arranged in a transition zone within the crucible unit. The transition zone preferably also includes a seed holder unit and a receiving space. The starting material may be converted from a solid configuration to a vapor configuration, and from the vapor configuration to a solid target. The starting material may be disposed within the receiving space, and wherein the solid target may be held by the seed holder unit. The solid target is crystalline, especially SiC. The gas introduced through the gas inlet is preferably mixed and/or reacted with the starting material of the steam configuration and/or during solidification. The gas outlet is preferably located in a capture zone which also comprises the outlet surface of the filter unit, wherein the gas composition in the capture zone is preferably purged of Si vapor or no Si vapor. The temperature in the trapping region is preferably below the solidification temperature of the gaseous Si or Si vapor. This embodiment is advantageous because the crystal growth process can be manipulated. For example, it may add one or more gases to dope the crystals. Additionally or alternatively, it may modify, in particular accelerate, the transport of the vapor from the receiving space to the wafer 18 or crystallization. Additionally or alternatively, the gas may be provided at a defined temperature or temperature range.

An inert gas, in particular argon, or a gas mixture, in particular argon and nitrogen, can be introduced into the crucible unit or into the crucible volume or into the conversion zone via the gas inlet.

According to another preferred embodiment of the invention, the size of the crucible housing is programmable or changeable. The crucible enclosure encloses a first volume VI in a crystal growth configuration and the crucible enclosure encloses a second volume VII in a coating regeneration configuration. The crystal growth configuration refers to a configuration or setting that occurs on the wafer 18, or at the growth front of crystals grown on the wafer 18, during the period of crystallization or during solidification of the evaporated starting material. The regeneration configuration represents a setting that occurs when the seed holder unit is removed and no crystal growth is possible because of the absence of the wafer 18. In the regeneration configuration, the filter unit is preferably not part of the crucible unit, and the lid disposed on top of the filter unit in the crystal growth configuration preferably contacts a sidewall portion of the crucible housing that contacts a lower end of the filter unit during the crystal growth configuration. Volume VI is preferably larger than volume VII, wherein volume VI is at least 10%, or at least or at most 20%, or at least or at most 30%, or at least or at most 40%, or at least or at most 50%, or at least or at most 60%, or at least or at most 70%, or at least or at most 80%, or at least or at most 100%, or at least or at most 120%, or at least or at most 150%, or at least or at most 200%, or at least or at most 250% larger than volume VII. This embodiment is advantageous in that the crucible unit can be readjusted after use, in particular after one run or after a plurality of runs, in particular at most or at least 3 times, at most or at least 5 times, or at most or at least 10 times. The overall service life of the crucible unit is therefore very long. This provides a very cost-effective furnace apparatus, since more than one heating unit can be used.

The housing preferably has at least one further wall element in a crystal growth configuration compared to a layer regeneration configuration. The further wall element is preferably a filter unit or the filter unit. In the layer regeneration configuration, the filter unit is removed. The lower housing wall member contacting the housing of the filter unit in the crystal growth configuration and the upper housing wall member contacting the housing of the filter unit in the crystal growth configuration are in contact with each other in the coating regeneration configuration. In the coating regeneration configuration, preferably at least one seal is disposed between the lower housing wall member and the upper housing wall member. In the crystal growth configuration, at least one seal is preferably arranged between the filter unit and the upper housing wall assembly, and wherein at least one seal is preferably arranged between the filter unit and the lower housing wall assembly. This embodiment is advantageous in that leakage of gas or steam is prevented in any configuration.

According to another preferred embodiment of the invention, the crucible unit comprises one or at least one receiving space gas guiding element in a coating regeneration configuration. The receiving space gas directing assembly extends into the receiving space to direct gas into the receiving space. This embodiment is advantageous because the gas introduced during the coating regeneration configuration preferably contacts the surface of the receiving space.

According to another preferred embodiment of the invention, the gas inlet is arranged in the conversion zone of the crucible unit. The conversion zone preferably comprises a seed holder unit and/or a receiving space. This embodiment form is advantageous because the flow of vaporized starting material and/or the flow of composition of liquid flowing upward from the receiving space to the wafer 18 and/or growing crystal can be modified.

The receiving space gas guiding elements are preferably located at least partially on the respective gas distribution element, wherein the gas distribution element preferably holds the receiving space gas guiding elements, in particular by a shell-type connection. This embodiment is advantageous in that the setting can be performed quickly and easily.

The receiving space gas guiding assembly is preferably annular or circular. This embodiment is advantageous because the amount of vaporized starting material preferably matches the amount of vaporized material that solidifies on the crystallized wafer 18 compared to other shapes, such as rectangular receiving space shapes. The receiving space gas guiding member is preferably provided with or made of carbon and/or graphite.

According to a further preferred embodiment of the invention, the first and third segment-grown conductors form a fourth segment-grown conductor, in particular on the bottom side; and/or wherein the second and third segment-grown conductors are arranged at an angle between 60 ° and 120 °, in particular at an angle between 70 ° and 110 °, in particular at an angle of 90 °.

Preferably a growth plate gas directing member is provided to direct gas to the surface of the top of the third stage growth directing member. The growth plate gas guiding member is preferably annular or circular. The growth plate gas directing member is preferably disposed in the upper or top wall portion of the housing. The growth plate gas guiding assembly is preferably of carbon or made of carbon and/or graphite.

Accordingly, a method and reactor or furnace apparatus for PVT growth of SiC single crystals preferably comprises the following: providing a furnace volume that can accommodate the crucible unit and the heater and is insulated; and/or providing a crucible unit having a lid inside the vacuum chamber and/or having a seed holder integrated to or attached to the lid and/or having a SiC single crystal attached to the seed holder and/or having an axial heater located below the crucible unit such that a radially flat temperature isothermicity can be produced in the growing crystal; and/or placing source material into the crucible unit such that there is no source material between the axial heat source and the seed crystal; and/or creating a vacuum in the crucible unit, heating and sublimating the source material (originating from the method of the invention) for the SiC solid material, and growing crystals, in particular SiC single crystals.

Drawings

Other advantages, objects and features of the invention will be explained with reference to the following description of the drawings, in which the device of the invention is shown by way of example. Elements or components of the inventive device, which correspond at least substantially in function to each other in the figures, may be identified by the same reference numerals, wherein these elements or components are not numbered or explained in all figures.

The figures described below are preferably each and every representation of the drawings, preferably taken as a structural drawing, i.e., the dimensions, proportions, functional relationships, and/or arrangements, generated by the drawings are preferably true or preferably substantially correspond to the apparatus or the product of the present invention or the method of the present invention.

Wherein the following are displayed:

FIG. 1 schematically shows an example of an apparatus for carrying out the method of the invention, and

fig. 2 schematically shows an example of a PVT reactor in which the SiC solid material of the present invention is introduced as a starting material.

Detailed Description

Fig. 1 shows an example of a manufacturing apparatus 850 for manufacturing SiC materials, particularly 3C-SiC materials. The apparatus 850 includes a first feed device 851, a second feed device 852, and a third feed device 853. The first feed means 851 is preferably designed as a first mass flow controller, in particular for controlling 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 comprises Si, in particular for example the general composition SiH _4- _m Cl _m Silane/chlorosilane or general composition SiR _4-m Cl _m Organochlorosilanes of (wherein r=hydrogen, hydrocarbon or chlorohydrocarbon). The second feed device 852 is preferably designed as a second mass flow controller, in particular for controlling 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 comprises C, such as hydrocarbons or chlorohydrocarbons, preferably boiling point<Methane is particularly preferred at 100 ℃. The third feed device 853 is preferably designed as a third mass flow controller, in particular for controlling the mass flow of a carrier fluid, in particular a carrier gas, wherein the carrier fluid or carrier gas preferably comprises H or H, respectively ₂ Or a mixture of hydrogen and an inert gas.

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

The vaporized fluid mixture is then fed to a process chamber 856 or separator vessel, which is designed as a pressure vessel. At least one deposition assembly 857 and preferably a plurality of deposition assemblies 857 are arranged in the process chamber 856, wherein Si and C are deposited and SiC is formed from the vaporized fluid mixture at the deposition assembly 857.

Reference numeral 858 designates a temperature measuring device, which is preferably provided for determining the surface temperature of the deposition assembly 857, and which is preferably connected to a control device (not shown) by data and/or signal technology.

Reference numeral 859 indicates an energy source, in particular for introducing electrical energy into the separation assembly 857 for heating the separation assembly. The energy source 859 is thus preferably also connected to control means based on signals and/or data. Preferably, the control device controls the supply of energy, in particular the supply of electricity, through the deposition assembly 857 in dependence on the measurement signals and/or measurement data output by the temperature measurement device 858.

Further, the pressure retention device is indicated by reference numeral 860. The pressure maintenance device 860 may preferably be implemented by a pressure regulator valve or operating pressure of the downstream exhaust treatment system.

Fig. 2 shows an embodiment of a furnace or furnace apparatus 100 or PVT furnace or PVT reactor according to the principles of the present invention, wherein SiC solid material, in particular 3C-SiC, manufactured according to the present invention is introduced into this PVT furnace or PVT reactor as starting material for manufacturing preferably monocrystalline SiC solid material. The furnace 100 is cylindrical and includes a lower furnace unit or lower furnace housing 2, and an upper furnace unit or upper furnace housing 3, both of which are generally of double wall water cooled stainless steel construction, defining a furnace volume 104. The lower furnace shell 2 has a furnace gas inlet 4 and the upper furnace shell 3 has a furnace vacuum outlet 204. Inside the furnace volume 104 is a crucible unit supported by crucible legs 13. Below the crucible unit is an axial heating assembly 214 and around the sides of the crucible unit is a radial heating assembly 212. Below the axial heating assembly 214 is the bottom insulator 8 and around the radial heating assembly 212 is the side insulator 9. The lower crucible housing 152 has a solid central portion surrounded by an annular channel in which the feedstock 50 is loaded. The crucible gas inlet tube 172 seals off the lower central portion of the lower crucible housing 152 and process gases, such as argon and nitrogen, flow through the solid central portion well and are distributed into the crucible volume by the gas distribution plate 190. A crucible gas inlet pipe or crucible gas inlet line 172 connects to an adjustable crucible gas inlet 5 extending through the lower furnace housing 2.

The lower crucible enclosure 152 also includes a growth guide assembly 230 for adjusting the thermal field and vapor flow around the sides of the crystal 17. Crystallization 17 atGrown on the wafer 18 to which the seed holder 122 is attached. Seed holder 122 seals off the lower inner edge of thick-walled tubular filter or filter unit 130. The lower crucible housing 152 seals off the lower periphery of this filter 130. The filter includes filter grooves 22 to add for removal of excess SiC ₂ With Si ₂ C surface area of sublimated vapor. The filter 130 also includes filter outer surface coatings 158, 164 on its inner and outer walls to minimize the permeability to Si vapor.

The upper peripheral edge of the filter 130 seals off the crucible cover or filter cover 107 or crucible upper housing 154, which in turn seals off the crucible vacuum outlet tube 174. The crucible vacuum outlet pipe 174 connects to the adjustable crucible vacuum outlet 26 that extends through the upper furnace housing 3. All sealing surfaces have a sealing body 20.

Crucible gas inlet tube 172, crucible unit, seed holder unit 122, filter 130, filter cover 107, and crucible vacuum outlet tube 174 define crucible volume 116. The bottom temperature of the gas distribution plate 190 is measured by the pyrometer along the lower pyrometer line of sight 7. The top temperature of the seed holder 122 is measured with a pyrometer along the upper pyrometer line of sight 28.

Oven 100 is operated at high temperature and low pressure. Oven volume 104 and crucible volume 116 are first purged with an inert gas (e.g., argon) to prevent oxidation. The axial heating element 214 and the radial heating element 212 are then used to create a thermal field within the crucible volume 116 such that the bottom temperature of the gas distribution plate 190 is typically in the range of 2200 to 2400 c and the temperature of the crystal growth surface is typically in the range of 2000 to 2200 c with a flat radial isothermal throughout the crystal 17. The lower temperature of the crystal 17 is obtained with little or no insulation above the seed holder 122, so that heat is passed through the crystal 17 and seed holder 122 and radiated to the water cooled inner wall of the upper furnace housing 3.

During crystal growth, the pressure inside the crucible volume 116 is typically in the range of 0.1 to 50 torr and slightly lower than the pressure inside the furnace volume 104. This negative relative pressure inside the crucible volume 116 minimizes leakage of sublimated vapor into the furnace volume 104.

At the position ofUnder the conditions of temperature and pressure, the starting material sublimates to release Si and SiC ₂ With Si ₂ And C, steam. The temperature gradient between the starting material 50 and the cooler crystals 17 drives these sublimated vapors towards the crystals 17, here SiC ₂ With Si ₂ The C vapor is incorporated into the crystal 17 and causes it to grow. Excess of SiC ₂ With Si ₂ The C vapor forms polycrystalline deposits on the side surfaces of the seed holder unit 122, the lower surface of the filter 130, and the upper inner wall of the crucible unit. In one embodiment, the low flow rate of argon and/or nitrogen convectively aids in thermally driven diffusion of the sublimated vapor to the crystals 17. In another embodiment, a low flow rate of nitrogen is added to dope the crystal 17 and modify its electrical properties. The gas flows radially outward from the gas distribution plate 190 and mixes with the sublimated vapor rising from the starting material 50.

All components within the furnace volume 104 are made of materials compatible with operating temperatures and pressures and that do not contaminate the crystal 17. In one embodiment, the bottom insulator 8 and the side insulator 9 may be made of graphite felt or graphite foam. The axial heating element 214 and the radial heating element 212 may be made of graphite, as may the crucible foot 13 and the crucible gas inlet tube 172.

The crucible base 152, gas distribution plate 190, wax-tumor (wax-tumor) conduction assembly 230, and seed holder 122 may all be made of materials that also minimize Si vapor permeation. These materials include glass-infiltrated graphite, vitreous carbon, thermally carbon coated graphite, tantalum carbide (tan-takarbide) ceramics, and coatings. Permeability of graphite of 10 ^-1 cm/s, whereas the glass-infiltrated graphite has a permeability of 10 ^-3 cm/s, permeability of glass carbon of 10 ^-11 cm/s, permeability of the thermal carbon-coated graphite of 10 ^-12 cm/s. Si vapor generated from the sublimated feedstock 50, which does not significantly penetrate these components or become embedded in the crystals 17, passes between the growth guide component 230 and the crystals 17 or growing crystals and enters the filter 130.

The filter 130 comprises a porous material having a large surface area. In one embodiment, the material is a bonded high temperature adhesive, such as a carbonized starch, having a unit surface area of about 2,000m ² Activated carbon powder/g. Inner and outer surfaces of filter 130The outer walls have filter outer surface coatings 158, 164 made of a material that minimizes Si vapor permeation. In one embodiment, the material is a glassy carbon coating. Because the Si vapor is substantially impermeable to the outer surface coatings 158, 164 of the filter, the Si vapor rises further into the filter 130 and eventually condenses on the upper portion of the filter 130 due to the lower temperature.

The invention may thus relate to a method or furnace apparatus or device for PVT growth of single crystals, in particular SiC single crystals, having many or all of the following features or steps:

a furnace enclosure is provided for housing the crucible unit, heating elements and insulators, the furnace enclosure also having an adjustable lower crucible gas inlet tube and an adjustable upper crucible vacuum outlet tube. A crucible unit and a growth guide are provided, both being substantially impermeable to Si vapor. The crucible unit is loaded with SiC source material.

A lid assembly for a crucible unit is provided, comprising: a high surface area annular porous filter for trapping Si sublimation vapor having outer and inner vertical tubular surfaces coated with a coating that is substantially impermeable to Si vapor and having upper and lower outer circumferential sealing shoulders; a seed holder. The filter comprises: a plurality of filter assemblies coated with a coating that is substantially impermeable to Si vapors and having upper and lower outer circumferential sealing shoulders; a seed holder that is also substantially impermeable to Si vapor and attaches to and seals the lower inner opening of the filter; a SiC single crystal seed attached to the seed holder; a filter cap sealing the upper outer circumferential sealing shoulder of the filter and also sealing the vacuum outlet tube of the crucible.

Raising the crucible gas inlet tube and lowering the crucible vacuum outlet tube such that the crucible gas inlet tube compresses and seals the crucible unit apart; the crucible unit presses and seals against a lower outer circumferential sealing shoulder of the filter, an upper outer circumferential sealing shoulder of the filter presses and seals against a filter cap, and the filter cap presses and seals against a crucible vacuum outlet tube. Seals are provided at all sealing interfaces to improve the hermeticity of the sealing interfaces.

An inert vacuum is established within the crucible volume defined by the crucible unit and filter assembly. An inert vacuum is established within the furnace volume via a respective furnace gas inlet and a respective furnace vacuum outlet.

The pressure of the crucible volume is maintained at a lower pressure than the furnace volume. The starting material is heated and sublimated.

The flow of carrier gas and dopant gas (if needed) into the crucible unit is actuated. The confinement of the Si vapors in the filter prevents the Si vapors from penetrating and coating the crucible unit, heating elements, insulators, and any other elements in the furnace volume, while allowing crystal growth.

Accordingly, it is preferable to provide a PVT furnace for producing SiC single crystal in which Si vapor is prevented from penetrating through the crucible housing wall, heating element, and insulator in sublimation. First, penetration of Si vapors into these components changes their thermal properties and it is difficult to grow good crystals because the thermal field is unstable. Second, the physical structure of these components is eventually destroyed by Si. The PVT oven of the present invention thus avoids this infiltration.

Preferably by making the wall, in particular the inner wall of the crucible housing, impermeable to Si vapor and/or removing Si vapor from the gas mixture inside the crucible volume, in particular by adsorption and condensation or deposition on a surface, which may be a filter. This surface may be located, for example, inside or outside the crucible unit, inside the furnace or even outside the entire furnace unit. Where the surface is located outside the crucible unit, it is preferred to provide fluid communication by at least one conduit or system of conduits that function to connect the surface to the volume of the crucible.

In this way, the heating element can be introduced into the furnace volume and generate the thermal field required for large diameter embryoid growth without fear of the heating element being destroyed by Si vapor. In this way the lifetime of the insulator and the crucible shell can be dramatically prolonged. In addition, since all of these materials have stable thermal properties, a higher embryo yield is possible that meets specifications.

In principle, the invention also relates to a furnace apparatus 100 for introducing SiC solid material, in particular 3C-SiC, produced according to the invention into a furnace apparatus 100, in particular for growing crystals, in particular for growing SiC crystals, in particular monocrystalline crystals. The furnace apparatus comprises a furnace unit 104, wherein the furnace unit 102 comprises a furnace housing 108; at least one crucible unit, wherein the crucible unit is arranged within the furnace housing 108, wherein the crucible unit comprises a crucible housing 110, wherein the housing 110 comprises 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 the starting material 50 is configured or formed within the crucible volume 116, wherein a seed holder unit 122 for holding the defined wafer 18 is configured within the crucible volume 116; and at least one heating unit 124 for heating the starting material 50, wherein a receiving space 118 for receiving the starting material 50 is at least partially arranged between the heating unit 124 and the seed holder unit 122.

Furthermore, the present invention relates to a reactor 100, and more particularly a reactor 100 for crystal growth, and more particularly for SiC crystal growth. The reactor comprises a furnace 102, the furnace 102 comprising a furnace chamber 104; at least one crucible arranged within the furnace chamber 104, the crucible comprising a frame structure 108, the frame structure 108 comprising an outer shell 110, the outer shell 110 comprising an outer surface 112 and an inner surface 114, the inner surface 114 at least partially forming a crucible chamber 116, wherein a receiving space 118 for receiving the source material 50 is configured or formed within the crucible chamber 116, wherein a seed holder unit 122 for holding a defined wafer is configured within the crucible chamber 116; and at least one heating unit 124 for heating the source material 50, wherein the receiving space 118 for receiving the source material 50 is at least partially arranged between the heating unit 124 and the seed holder unit 122.

The present invention is therefore directed to a method of making a preferably elongated SiC solid, especially polytype 3C. The method of the present invention preferably comprises at least the steps of:

introducing at least one first source gas into the 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,

Supplying power to at least one separator assembly disposed in the process chamber to heat the separator assembly,

the deposition rate was set to be over 200 μm/h,

wherein a pressure of more than 1 bar is generated in the process chamber by introducing a first source gas and/or a second source gas, and

wherein the deposition assembly surface is heated to a temperature in the range between 1300 ℃ and 1700 ℃.

List of reference numerals

1PVT reactor

2 furnace outer casing (lower part)

3 furnace shell (Upper)

4. Furnace gas inlet

5. Crucible gas inlet

7. Bottom insulator of crucible gas inlet connecting sheet 8

9. Side insulator

13. Crucible leg

17. Crystallization

18. Wafer with a plurality of wafers

20. Sealing body

22. Filter channels or holes

26. Crucible vacuum outlet

28. Pyrometer line of sight

50. Source material

100. Furnace with a heat exchanger

102. Hydrogen gas

104. Furnace volume

107. Crucible cover

122. Seed holder

130. Filter device

152. Crucible base

158. Filter outer surface coating 164 filter outer surface coating 172 crucible gas inlet tube 174 crucible vacuum outlet tube

204. Oven vacuum outlet

212. Radial heating assembly

214. Heating assembly

230. Growth guide assembly

231. Growth guide assembly top

850. Manufacturing apparatus

851. First feeding device

852. Second feeding device

853. Third feeding device

854. Mixing device

855. Evaporator device

856. Treatment chamber

857. Separation assembly

858. Temperature measuring device

859 energy source, especially power supply

860 pressure maintenance means.

Claims

1. A method of making a SiC solid, preferably an elongated SiC solid, particularly polytype 3C SiC solid,

at least comprises the following steps:

the deposition rate was set to be over 200 μm/h,

wherein the surface of the deposition assembly is heated to a temperature in the range between 1300 ℃ and 1700 ℃.

2. The method according to claim 1,

the method is characterized by comprising the following steps of:

at least one carrier gas, preferably comprising H, is introduced into the process chamber.

3. A method of making a SiC solid, preferably an elongated SiC solid, particularly polytype 3C SiC solid,

Comprising at least the following steps:

at least one source gas, in particular a first source gas, in particular SiCl ₃ (CH ₃ ) Introducing into a process chamber, the source gas comprising Si and C,

at least one carrier gas, preferably comprising H,

the deposition rate was set to be over 200 μm/h,

wherein a pressure of more than 1 bar is generated in the process chamber by introducing a source gas and/or carrier gas, an

4. The method according to any of the preceding claims,

it is characterized in that

The pressure in the process chamber is generated between 2 bar and 10 bar by introducing the first source gas and/or the second source gas, preferably between 4 bar and 8 bar by introducing the first source gas and/or the second source gas, particularly preferably between 5 bar and 7 bar, especially 6 bar by introducing the first source gas and/or the second source gas.

5. The method according to any of the preceding claims,

It is characterized in that

The surface of the deposition assembly is heated to a temperature in the range between 1450 and 1700 ℃, in particular in the range between 1500 and 1600 ℃.

6. The method according to any of the preceding claims,

it is characterized in that

Introducing a first source gas into the process chamber via a first supply means and introducing a second source gas into the process chamber via a second supply means,

or the first source gas and the second source gas are mixed before being introduced into the process chamber and introduced into the process chamber through the supply device,

wherein the source gases are mixed and introduced into the process chamber in Si: C molar ratios of si=1 and c=0.8 to 1.1 and/or Si: C atomic ratios of si=1 and c=0.8 to 1.1.

7. The method according to claim 6, wherein the method comprises,

it is characterized in that

The carrier gas comprises H

Wherein the source gas and the carrier gas are introduced into the process chamber in Si: C: H molar ratios of si=1 and c=0.8 to 1.1 and h=2 to 10, in particular Si: C: H molar ratios of si=1 and c=0.9 to 1 and h=3 to 5, and/or Si: C: H atomic ratios of si=1 and c=0.8 to 1.1 and h=2 to 10, in particular Si: C: H atomic ratios of si=1 and c=0.9 to 1 and h=3 to 5.

8. The method according to any of the preceding claims,

It is characterized in that

The deposition rate is set in the range between 300 μm/h and 2500 μm/h, in particular in the range between 350 μm/h and 2300 μm/h, in particular in the range between 400 μm/h and 2000 μm/h, in particular in the range between 450 μm/h and 1800 μm/h.

9. The method according to any of the preceding claims,

it is characterized in that

Measuring the surface temperature of a deposition assembly using a temperature measuring device, in particular a pyrometer, which outputs temperature signals and/or temperature data, an

The control means modifies, in particular increases, the electrical load of the separator assembly as a function of the temperature signal and/or the temperature data.

10. The method according to claim 9, wherein the method comprises,

it is characterized in that

The temperature measuring device performs temperature measurement and outputs a temperature signal and/or temperature data at time intervals of less than 5 minutes, in particular less than 3 minutes, or less than 2 minutes, or less than 1 minute, or less than 30 seconds,

wherein the target temperature is defined such that,

wherein the control means controls the power supply to increase as long as the temperature signal and/or the temperature data indicate that the surface temperature is below a defined critical temperature, wherein the critical temperature is a temperature below a defined value, preferably less than 10 ℃, or less than 5 ℃, or less than 3 ℃, or less than 2 ℃, or less than 1.5 ℃, or less than 1 ℃.

11. The method according to any of the preceding claims,

it is characterized in that

More source gas, in particular the first source gas and/or the second source gas, per unit time is introduced into the process chamber continuously or stepwise, in particular in defined proportions,

preferably more source gas, in particular the first source gas and/or the second source gas, is introduced into the process chamber as a function of time and/or more source gas, in particular the first source gas and/or the second source gas, is introduced into the process chamber as an electrical load function.

12. An apparatus for producing a preferably elongated SiC solid, in particular a polytype 3C SiC solid, in particular for carrying out the aforementioned method,

comprising at least

A process chamber for receiving a rechargeable deposition assembly, a first source gas comprising Si, a second source gas comprising C,

first supply means for supplying a first source gas into the process chamber at a pressure exceeding 1 bar and/or second supply means for supplying a second source gas into the process chamber at a pressure exceeding 1 bar,

a temperature measuring device for measuring the surface temperature of the deposition assembly,

Control means for setting the deposition rate to be more than 200 μm/h,

wherein the control means is capable of adjusting the power supply to the separator assembly, wherein the power supply is capable of being adjusted from 1300 ℃ to 1700 ℃ to produce the surface temperature.

13. An apparatus for producing a preferably elongated SiC solid, in particular a polytype 3C SiC solid, in particular for carrying out the aforementioned method,

comprising at least

A process chamber for receiving a rechargeable deposition assembly, at least one source gas, particularly SiCl, and a carrier gas into the process chamber ₃ (CH ₃ ) The source gas comprises Si and C, the carrier gas preferably comprises H,

a first feed device for introducing a source gas into the process chamber at a pressure exceeding 1 bar and/or a second feed device for introducing a carrier gas into the process chamber at a pressure exceeding 1 bar,

control means for setting the deposition rate to be more than 200 μm/h,

wherein the control means is capable of adjusting the power supply to the separator assembly, the power supply being capable of being adjusted from 1300 ℃ to 1700 ℃ to produce the surface temperature.

14. Purity excludes at least 99.9999% (weight ppm) of material B, al, P, ti, V, fe, ni and/or density less than 3.21g/cm ³ And especially a 3C-SiC solid material,

which is manufactured by the method according to any one of claims 1 to 11.

15. Use of the SiC solid material according to claim 14 in a PVT reactor for manufacturing single crystal SiC.