WO2025051951A1

WO2025051951A1 - Method and system for sic production and improved vent gas recycling

Info

Publication number: WO2025051951A1
Application number: PCT/EP2024/074980
Authority: WO
Inventors: Ivo Crößmann; Michael Schley; Jörg Pfister; Friedrich Schaaff
Original assignee: Zadient Technologies SAS
Current assignee: Zadient Technologies SAS
Priority date: 2023-09-06
Filing date: 2024-09-06
Publication date: 2025-03-13
Anticipated expiration: 2026-03-06
Also published as: WO2025051359A1

Abstract

The present invention refers to a method for the production of SiC. The method at least comprises the steps: Providing a vent gas mixture (2400), wherein the vent gas mixture (2400) is preferably generated during SiC production and highly preferably generated during CVD SiC production, wherein at least one fraction of the vent gas mixture is HCl and/or STC, wherein further fractions (2401) of the vent gas mixture (2400) at least comprise H2 (2402) and a C-bearing-molecule, in particular methane, (2404), Generating Chlorosilanes (2394) by reacting the at least one fraction of the vent gas mixture and Si (2398), Forwarding at least the generated Chlorosilanes (2394) into a process chamber (856a) of the CVD SiC production reactor (850a), and Forwarding at least one C-bearing molecule into the CVD SiC production reactor (850a), Producing SiC inside the process chamber (856a) of the CVD SiC production reactor (850a) by depositing Si from the Chlorosilanes and C from the at least one C-bearing molecule on at least one deposition surface or Forwarding at least the generated Chlorosilanes (2394) into a process chamber (856b) of a further CVD SiC production reactor (850b), and Forwarding at least one C-bearing molecule into the further CVD SiC production reactor (850b), Producing SiC inside the process chamber (856) of the further CVD SiC production reactor (850b) by depositing Si from the Chlorosilanes and C from the at least one C- bearing molecule on at least one deposition surface.

Description

Method and system for SiC production and improved vent gas recycling

The present invention refers according to claims 1, 2 and 50 to methods for the production of SiC and according to claims 49 and 51 to systems comprising at least a CVD SiC production reactor and a bed reactor.

Document WO2022123083A2 discloses a method for the production of SiC as well as recycling of Chlorosilanes present inside the vent gas of the SiC CVD reactor. Document WO2019201439A1 discloses a system for the production of polycrystalline Si and a bed reactor for generating Chlorosilanes. Said bed reactor is hereby loaded with high-purity Si particles of defined particle size produced during the Si production.

Documents DE102010044108 and DE102004059191 B4 provide further methods and devices for producing chlorosilane from the reaction of silicon with hydrogen chloride.

It is the object of the present invention to provide an improved method and/or an improved system for the production of SiC (silicon carbide), preferably a more efficient method and/or system for the production of SiC is provided.

The above-mentioned object is solved by a method for the production of SiC according to claim 1. Said method for the production of SiC preferably comprises at least the steps:

Providing a vent gas mixture, wherein the vent gas mixture is preferably generated during SiC production and highly preferably generated during CVD SiC production, wherein at least a first fraction of the vent gas mixture is HCI, wherein a second fraction of the vent gas mixture consists of vent gas Chlorosilanes, in particular STC and/or TCS, or wherein a second fraction of the vent gas mixture comprises of vent gas Chlorosilanes, in particular STC and/or TCS, wherein a third fraction of the vent gas mixture comprises or consists of H2 and wherein a fourth fraction of the vent gas mixture comprises or consists of at least one C-bearing-molecule, in particular methane, Providing solid Si inside a reactor chamber, wherein the solid Si comprises metal impurities of more than 1000ppmw,

Forwarding at least the second fraction of the vent gas mixture into the reactor chamber and preferably the second fraction of the vent gas mixture and the third fraction of the vent gas mixture and one more fraction of the vent gas mixture and particular preferably at least the second fraction of the vent gas mixture and the first fraction of the vent gas mixture and most preferably all fractions of the vent gas mixture into the reactor chamber,

Generating Chlorosilanes inside the reactor chamber by reacting the second fraction of the vent gas mixture, in particular STC and/or TCS, and the solid Si and preferably by reacting at least the second fraction of the vent gas mixture and the first fraction of the vent gas mixture, Forwarding at least the generated Chlorosilanes into a process chamber of the CVD SiC production reactor, and Forwarding at least one C-bearing molecule into the CVD SiC production reactor, Producing SiC inside the process chamber of the CVD SiC production reactor by reacting the generated Chlorosilanes and C from the at least one C-bearing molecule on at least one deposition surface or Forwarding at least the generated Chlorosilanes into a process chamber of a further CVD SiC production reactor, and Forwarding at least one C- bearing molecule into the further CVD SiC production reactor, Producing SiC inside the process chamber of the further CVD SiC production reactor by reacting the generated Chlorosilanes and C from the at least one C-bearing molecule on at least one deposition surface.

This solution is beneficial since vent gas fractions can be used to generate Chlorosilanes. Thus, the overall output can be increased and less feed gas needs to be delivered from a feed gas production plant. Therefore, less resource consumption takes place since less transportation takes place and also risks for accidents and therefore pollution are reduced.

In view of the present disclosure the term “reacting” has to be understood in terms of a chemical vapor deposition step.

The above-mentioned object is also solved by a method for the production of SiC according to claim 1. Said method for the production of SiC preferably comprises at least the steps:

Providing a vent gas mixture, wherein the vent gas mixture is preferably generated during SiC production and highly preferably generated during CVD SiC production, wherein at least a first fraction of the vent gas mixture is HCI, wherein a second fraction of the vent gas mixture consists of vent gas Chlorosilanes, in particular STC and/or TCS, wherein a third fraction of the vent gas mixture comprises or consists of H2 and wherein a fourth fraction of the vent gas mixture comprises or consists of at least one C- bearing-molecule, in particular methane,

Providing solid Si inside a reactor chamber, wherein the solid Si comprises metal impurities of 1000ppmw or of less than 1000ppmw,

Forwarding at least the second fraction of the vent gas mixture and the third fraction of the vent gas mixture and the fourth fraction of the vent gas mixture and most preferably all fractions of the vent gas mixture into the reactor chamber,

Generating Chlorosilanes inside the reactor chamber by reacting the second fraction of the vent gas mixture, in particular STC and/or TCS, and the solid Si and preferably by reacting at least the second fraction of the vent gas mixture and the first fraction of the vent gas mixture, Forwarding at least the generated Chlorosilanes into a process chamber of the CVD SiC production reactor, and

Forwarding at least one C-bearing molecule into the CVD SiC production reactor, Producing SiC inside the process chamber of the CVD SiC production reactor by reacting the generated Chlorosilanes and C from the at least one C-bearing molecule on at least one deposition surface or

Forwarding at least the generated Chlorosilanes into a process chamber of a further CVD SiC production reactor, and

Forwarding at least one C-bearing molecule into the further CVD SiC production reactor, Producing SiC inside the process chamber of the further CVD SiC production reactor by reacting the generated Chlorosilanes and C from the at least one C-bearing molecule on at least one deposition surface.

Thus the above-mentioned object could also be solved by the following SiC production method: Providing a vent gas mixture, wherein the vent gas mixture is preferably generated during SiC production and highly preferably generated during CVD SiC production, wherein at least a first fraction of the vent gas mixture is HCI, wherein a second fraction of the vent gas mixture consists of vent gas Chlorosilanes, in particular STC and/or TCS, wherein a third fraction of the vent gas mixture comprises or consists of H2 and wherein a fourth fraction of the vent gas mixture comprises or consists of at least one C- bearing-molecule, in particular methane,

Providing solid Si inside a reactor chamber, wherein the solid Si comprises metal impurities of more than 1000ppmw or of 1000ppmw or of less than 1000ppmw,

Generating Chlorosilanes inside the reactor chamber by reacting the second fraction of the vent gas mixture, in particular STC and/or TCS, and the solid Si and preferably by reacting at least the second fraction of the vent gas mixture and the first fraction of the vent gas mixture,

Forwarding at least the generated Chlorosilanes into a process chamber of the CVD SiC production reactor, and

The term “STC and/or TCS” has preferably to be understood in the context of the present invention as STC alone or TCS together with STC.

This solution is advantageous because the overall system can be simplified by using pure Si, in particular PV-suitable silicon, which preferably has an iron content of <1000ppmw. In particular, shorter distillation steps or fewer distillation steps can be provided for the resulting chlorosilane gas. Particularly preferably, the distillation of high boilers (metal silanes) can be completely omitted. This results in less complexity (fewer devices, less measuring effort, fewer product controls, etc.) and the production process is also accelerated. Both lead to significantly lower costs. The pure Si (silicon) can, for example, be scrap from the production process for the manufacture of photovoltaic silicon. Metallurgical silicon usually has a purity of around 98-99%, while PV silicon requires purity levels of 99.9999% (6N) or higher. In order to achieve this level of purity, complex processes such as chemical vapor deposition (CVD) and other expensive purification processes are required.

As a starting material, PV silicon or silicon with an iron content of less than 1000ppmw leads to significant simplifications in the production of high-purity chlorosilanes in a fluidized bed reactor.

The present invention is highly beneficial due to a plurality of advantages.

On the one hand it was surprisingly found that C-bearing molecules do not negatively affect the chemical conditions inside the reactor chamber. That finding allows to significantly simplify the invention since an entire distillation step is obsolete.

On the other hand the remaining distillation steps can be configured in such a manner that less pure Si (>95% instead of >99%) can be used for the production of Chlorosilanes also causing a significant cost advantage. Further preferred embodiments of the present invention are described in the following specification parts and/or are subject-matter of the dependent claims.

It is possible according to a preferred embodiment of the present invention to separate the vent gas prior to supplying it into the reactor into two or more than two fractions, in particular into three or more than three fractions and highly preferably into four fractions. The first fraction of the vent gas mixture is preferably HCI or comprises HCI. The second fraction of the vent gas mixture preferably comprises or consists of vent gas Chlorosilanes, in particular STC and/or TCS. A third fraction of the vent gas mixture preferably comprises or consists of H2. A fourth fraction of the vent gas mixture preferably comprises or consists of at least one C-bearing- molecule, in particular methane. However, it is also possible to provide two fractions wherein the first fraction comprises or consists of HCI and vent gas Chlorosilanes, in particular STC and/or TCS and wherein the second fraction comprises or consists of H2 and a C-bearing- molecule, in particular methane.

Another preferred embodiment of the present invention comprises a step of reducing the amount of metal impurities, at least Fe impurities, Al impurities and/or all metal impurities, within the generated Chlorosilanes below 20ppmw and preferably below 10ppmw and highly preferably below 5ppmw and most preferably below 1ppmw. This embodiment is beneficial since SiC - without such metal impurities - can be used to produce a wide range of products, in particular in view of chips and power devices.

The step of reducing the amount of metal impurities within the generated Chlorosilanes below 20ppmw and preferably below 10ppmw and highly preferably below 5ppmw and most preferably below 1ppmw is according to a further preferred embodiment of the present invention carried out before the generated Chlorosilanes are forwarded into the process chamber of the CVD SiC production reactor or into the process chamber of the further CVD SiC production reactor. This embodiment is beneficial since contamination of the CVD SiC production reactor can be prevented. Thus, less downtime for cleaning or maintenance is necessary.

The step of reducing the amount of metal impurities, at least Fe impurities, Al impurities and/or all metal impurities, within the generated Chlorosilanes below 20ppmw and preferably below 10ppmw and highly preferably below 5ppmw and most preferably below 1ppmw is according to a further preferred embodiment of the present invention splitted into at least a first removal step and into a second removal step, wherein a first amount of metal impurities is removed in the first removal step and wherein a second amount of metal impurities is removed in a second removal step. This embodiment is beneficial since due to different metal impurities different conditions and/or techniques can be applied to remove the metal impurities, thus removing the metal impurities in multiple steps, in particular two or more than two steps, efficiency of the individual step can be increased.

According to a further preferred embodiment of the present invention a step of separating the generated Chlorosilanes and the third fraction of the vent gas mixture and the fourth fraction of the vent gas mixture into a first fluid and into a second fluid is carried out. This embodiment is beneficial since separated substances can be treated in more efficient manner.

In general it is possible that the mass of the third fraction of the vent gas mixture can be reduced due to the step of generating Chlorosilanes inside the reactor chamber by reacting the second fraction of the vent gas mixture, in particular STC, and the third fraction of the vent gas mixture and the solid Si.

The step of reducing the amount of metal impurities, at least Fe impurities, Al impurities and/or all metal impurities, within the generated Chlorosilanes below 20ppmw and preferably below 10ppmw and highly preferably below 5ppmw and most preferably below 1ppmw and the step of separating the generated Chlorosilanes and the third fraction of the vent gas mixture and the fourth fraction of the vent gas mixture into a first fluid and into a second fluid are according to a further preferred embodiment of the present invention carried out by a separating unit.

The first removal step and the step of separating the generated Chlorosilanes and the third fraction of the vent gas mixture and the fourth fraction of the vent gas mixture into a first fluid and into a second fluid are carried out by a separating unit.

The second removal step is according to a further preferred embodiment of the present invention carried out by another device, in particular a further separating unit, in particular a Chlorosilane distillation column.

The step of reducing the amount of metal impurities within the generated Chlorosilanes below 20ppmw and preferably below 10ppmw and highly preferably below 5ppmw is according to a further preferred embodiment of the present invention carried out after the step of separating the generated Chlorosilanes and the third fraction of the vent gas mixture and the fourth fraction of the vent gas mixture into the first fluid and into the second fluid.

The vent gas mixture is according to a further preferred embodiment of the present invention feed from the CVD SiC production reactor to the reactor chamber, wherein the reactor chamber is part of a bed reactor, and/or from at least one further CVD SiC production reactor to the reactor chamber, wherein the reactor chamber is part of the bed reactor, wherein the step of generating Chlorosilanes by reacting the first fraction of the vent gas mixture and Si is carried out inside the bed reactor, and/or the step of generating chlorosilanes by reacting the second fraction of the vent gas mixture, in particular STC, and the third fraction of the vent gas mixture and the solid Si is carried out inside the bed reactor, wherein the bed reactor is preferably a fixed bed reactor or a fluidized bed reactor. This embodiment is beneficial since multiple fractions of the vent gas can be used to generate Chlorosilanes, in particular at the same time. Thus, less HCI treatment and less providing of new Chlorosilane is possible, causing the method according to the present invention to be highly efficient.

It is preferred to feed the vent gas mixture without chemical treatment into the bed reactor. Chemical treatment is herewith understood as any treatment that removes one component respectively substance from the vent gas mixture, in particular by distillation.

However, it is also possible to remove HCI or STC or TCS prior to the step of generating Chlorosilanes by reacting at least one fraction of the vent gas mixture and Si from the vent gas mixture. Preferably HCI can be removed. In this case the at least one fraction of the vent gas mixture reacting with Si is preferably STC. Alternatively, STC can be removed from the vent gas mixture prior to the step of Generating Chlorosilanes by reacting at least one fraction of the vent gas mixture and Si. In this case the at least one fraction of the vent gas mixture reacting with Si is preferably STC.

The vent gas mixture is according to a further preferred embodiment of the present invention removed from the CVD SiC production reactor or from the at least one further CVD SiC production reactor in a heated configuration, wherein the vent gas mixture has a condensation temperature, wherein the vent gas mixture is kept above the condensation temperature.

Solid Si is according to a further preferred embodiment of the present invention feed during the step of generating Chlorosilanes by reacting HCI and Si into the bed reactor. This embodiment is beneficial since the bed reactor can be run in continuous manner and therefore could be coupled to multiple CVD SiC production reactors for generating Chlorosilanes based on the vent gas of said multiple CVD SiC production reactors.

The at least one C-bearing molecule is according to a further preferred embodiment of the present invention a fraction of the second fluid or the second fluid consists of the at least one C- bearing molecule, wherein the step of forwarding at least one C-bearing molecule into the process chamber comprises forwarding the second fluid into the process chamber. The second fluid preferably comprises methane. It is additionally possible that the step of forwarding at least one C-bearing molecule into the process chamber also comprises forwarding one C-bearing molecule, in particular the same C-bearing molecule, in particular methane, from another C- bearing molecule source, in particular from another methane source. This embodiment is beneficial since the C-bearing molecule from the vent gas can be used to produce SiC. However, in case that C-bearing molecule is not available in a sufficient mass or volume additional c-bearing molecule can be provided.

According to a further preferred embodiment of the present invention a step of removing HCI from the second fluid prior to the step of forwarding at least one C-bearing molecule into the process chamber is carried out. This embodiment is beneficial since the removed HCI can be used for the production of Chlorosilanes and therefore increases efficiency of the present invention.

According to a further preferred embodiment of the present invention a step of forwarding the first fluid from the separating unit to a further separating unit for separating the first fluid into at least a first part and a second part prior to the step of forwarding the Chlorosilanes into the process chamber. This embodiment is beneficial since undesired parts can be removed from the first fluid. Thus, according to a further preferred embodiment of the present invention the further separating unit preferably carries out the step of reducing the amount of metal impurities within the generated Chlorosilanes below 20ppmw and preferably below 10ppmw and highly preferably below 5ppmw, wherein the first part of said two parts comprises the Chlorosilanes and wherein the second part of said two parts comprises metal impurities removed during the step of reducing the amount of metal impurities within the generated Chlorosilanes below 20ppmw and preferably below 10ppmw and highly preferably below 5ppmw.

According to a further preferred embodiment of the present invention a step of forwarding the first fluid from the separating unit to a further separating unit for separating the first fluid into at least a first part and a second part prior to the step of forwarding the Chlorosilanes into the process chamber. The first part of said two parts preferably is or preferably comprises TCS (Trichlorosilane) and wherein the second part of said two parts preferably is or preferably comprises STC (Silicon tetrachloride).

The step of forwarding the Chlorosilanes into the process chamber comprises according to a further preferred embodiment of the present invention forwarding the first part of said two parts and/or forwarding the second part of said two parts into the process chamber or wherein the step of forwarding the Chlorosilanes into the process chamber consists of forwarding the first part of said two parts and/or forwarding the second part of said two parts into the process chamber. This embodiment is beneficial since Chlorosilanes provided by the vent gas and Chlorosilanes generated or produced inside the reactor chamber can be used to produce SiC. The first storage and/or conducting element connects according to a further preferred embodiment of the present invention the separating unit with the further separating unit, wherein the further separating unit is coupled with a STC storage and a TCS storage, wherein the STC storage and/or the TCS storage forms a section of a Chlorosilanes mass flux path for conducting STC and/or TCS into the process chamber. This embodiment is beneficial since supply of Chlorosilanes removed from the vent gas and produced by reacting one or multiple fraction/s of the vent gas with Si into the process chamber does not depend on the actual output from the reactor chamber, since the necessary mass or volume or Chlorosilanes can be removed from the respective storage, namely the STC storage and/or the TCS storage).

The further separating unit is according to a further preferred embodiment of the present invention a distillation column. This embodiment is beneficial since distillation columns are very reliable and are able to handle high troughput.

STC is according to a further preferred embodiment of the present invention feed from the further separating unit, in particular the distillation column, to the STC storage and wherein TCS is feed from the further separating unit, in particular distillation column, to the TCS storage. According to a further preferred embodiment of the present invention metal chlorides (such as FeCI3 or AICI3) leave the reactor chamber, in particular of the bed reactor, in the form of particles or in the gas phase, depending on the conditions. Particulate solid metal chlorides can be discharged e.g. via solid separation (cyclones, filters). It is herewith referred to document DE2161641 A1 , since document DE2161641 A1 discloses e.g. a separating device or a further separating device, in particular distillation column.

Gaseous metal chlorides are according to a further preferred embodiment of the present invention carried on towards condensation and form a solution and/or suspension that can be separated by distillation. The resulting metal-rich heavy-boiling fraction is preferably discharged. STC is according to a further preferred embodiment of the present invention feed from the STC storage to the CVD SiC production reactor, without feeding TCS from the TCS storage to the bed reactor. This embodiment is beneficial since the fractions of STC which are part of the vent gas can be reacted to TCS inside the bed reactor.

According to a further preferred embodiment of the present invention a buffer storage is arranged or provided in fluid flow direction before the reactor chamber, in particular of the bed reactor. This embodiment is beneficial since the buffer storage can store the vent gas outputted by the SiC CVD reactor for continuous supply to the reactor chamber. The vent gas inside the buffer storage is preferably heated or held above the condensation temperature of the vent gas respectively above the lowest condensation temperature of the individual fractions of the vent gas.

The distillation column separates according to a further preferred embodiment of the present invention one or multiple metallic components, in particular B, Al, Fe and/or P, from the first fluid, in particular prior to the separation of STC and TCS, wherein separated metallic component/s is/are preferably feed to a waste storage. This embodiment is beneficial since Si can be provided inside the bed reactor respectively inside the reaction chamber that comprises said metallic components.

TCS is according to a further preferred embodiment of the present invention feed from the TCS storage to the bed reactor for converting at least a fraction of TCS into STC or STC is according to a further preferred embodiment of the present invention feed from the STC storage to the bed reactor for converting at least a fraction of STC into TCS. This embodiment is beneficial since multiple reactions can be carried out inside the bed reactor, in particular at the same time. According to a further preferred embodiment of the present invention a step of generating Chlorosilanes is carried out inside the reactor chamber by reacting the first fraction of the vent gas mixture and the solid Si. This embodiment is beneficial since multiple fractions of the vent gas are used to react with Si for the production of Chlorosilanes. Thus, the overall efficiency of the present solution is very high.

A CVD SiC production reactor of the herein described system/s and/or methods preferably comprises one CVD SiC production reactor and preferably also at least one further CVD SiC production reactor, wherein CVD SiC production reactor and/or the at least one further CVD SiC production reactor at least comprises:

A CVD SiC production reactor process chamber, wherein the process chamber is at least surrounded by a bottom wall section, in particular a base plate wall section, a side wall section and a top wall section, a gas inlet unit for feeding one feed-medium or multiple feed-mediums into a reaction space of the process chamber for generating a source medium, wherein the gas inlet unit is coupled with at least two feed-medium sources, wherein a Si feed medium source is at least coupled with a Chlorosilanes mass flux path for feeding the Chlorosilanes into the process chamber, wherein the Chlorosilanes preferably comprise STC or TCS or consist of STC or TCS separated from the first fluid, and wherein a C feed medium source is configured to provide at least C-bearing molecule, in particular natural gas, Methane, Ethane, Propane, Butane and/or Acetylene, and wherein a carrier gas medium source provides a carrier gas, in particular H2, multiple SiC growth substrates, in particular more than 3 or 4 or 6 or 8 or 16 or 32 or 64 or up to 128 or up to 256, are arranged inside the process chamber for depositing SiC, wherein a first SiC growth substrate of said multiple SiC growth substrates comprises at least a first growth face section facing into a first directing and a second growth face section facing into a second direction, wherein the second direction is aligned less than 20°, in particular less than 10° or less than 5°, to the opposite direction of the first direction, wherein a second SiC growth substrate of said multiple SiC growth substrates comprises at least a third growth face section facing into a third direction, wherein the third direction is aligned less than 20°, in particular less than 10° or less than 5°, to the first direction and a fourth growth face section facing into a fourth direction, wherein a third SiC growth substrate of said multiple SiC growth substrates comprises at least a fifth growth face section facing into the fifth direction, wherein the fifth direction is aligned less than 20°, in particular less than 10° or less than 5°, to the third direction and a sixth growth face section facing into a sixth direction, wherein the fourth growth face section overlays in the first direction at least 50% of the first growth face section, wherein the size of the fourth growth face section is at least 80%, in particular more than 90% or more 95%, of the size of the first growth face section, wherein the sixth growth face section overlays in the fifth direction at least 50% of the third growth face section, wherein the size of the sixth growth face section is at least 80%, in particular more than 90% or more 95%, of the size of the third growth face section.

This solution is beneficial since said CVD SiC production reactor and preferably also at least one further CVD SiC production reactor (preferably of the same type) can be utilized in a method of the present invention.

This solution is also beneficial since large surfaces are already present at the beginning of a production run and therefore allows fast deposition of SiC. Furthermore, since the multiple growth faces have a significant overlap heat radiation radiated form one growth face heats the overlapping growth face. Thus, heat losses can be reduced and therefore the overall production process can be carried out with less energy.

The distance of the opposing surface is preferably a defined distance, wherein that distance allows both high energy savings that and high-volume production that favors a long growth rate that results in thick deposition and wider spacing. Thus, a preferred arrangement between the plates respectively the opposing or overlaying growth face section is in between 10cm and 50 cm, in particular between 10cm and 40cm and preferably between 10cm and 30cm or between 20cm and 50cm and preferably between 30cm and 50cm, and the deposition thickness of SIC is preferably up to 1/3 of the spacing on each side. This means that at the end of the run preferably up to 2/3 of the initial spacing is filled with SiC and preferably 1/3 is left open for gas supply. Other arrangement are possible as well to optimize the gas flow and the gas conversion rate during the process. Highly preferably the deposition of SiC is less than 1/3 on each side to cause beneficial gas flux and gas turbulence. Further preferred embodiments are subject-matter of the following specification parts and/or of the dependent claims.

According to a preferred embodiment of the present invention at least the first SiC growth substrate covers from at least two sides a first heating unit, wherein the first heating unit and the first SiC growth substrate are configured to be non-destructively separatable from each other. This embodiment is beneficial since the heating unit does not have to be part of the SiC growth substrate, thus heating can be carried out different to heating resulting from conducting electric energy through the SiC growth substrate. Electric heating requires an adequate electric infrastructure which is very expensive and therefore increases the overall production costs. Thus, due to the present invention significant capex reduction can be caused.

According to a further preferred embodiment of the present invention the first SiC growth substrate is formed by a hollow housing, wherein the heating unit is positioned inside the hollow housing. This embodiment is beneficial since the heating unit radiates heat to multiple wall sections of the hollow housing and therefore heats the walls of the hollow housing and thereby heats the outer surface sections of the hollow housing and causes them to act as SiC growth faces.

According to a further preferred embodiment of the present invention the first SiC growth substrate is formed by a foil or holds a SiC growth foil. This embodiment is beneficial since the SiC deposits on the foil and therefore increases stability of the foil. Due to deposition of SiC on the foil the SiC can be removed from the process chamber by removing the foil from the process chamber.

According to a further preferred embodiment of the present invention the foil is arranged around at least two surface sections of a hollow housing respectively of the hollow housing, wherein the heating unit is positioned inside the hollow housing. This embodiment is beneficial since the hollow housing on the one hand protects the heating unit from SiC and on the other hand holds the foil to allow defined deposition of SiC onto the foil. The heating unit is preferably arranged inside the hollow housing in such a manner that a defined temperature distribution is set or can be set. Due to the defined temperature distribution the outer surface sections of the hollow housing are heated which are overlayed by the foil. The remaining surface section of the hollow housing are preferably less heated, in particular more than 5°C less or more than 10°C less or more than 20°C less or more than 50°C less. The walls of the hollow housing can be thinner in sections where the foil has to be located compared to sections where the foil does not contact the hollow housing. Thinner preferably means more than 1 mm thinner and highly preferably more than 3mm thinner and most preferably more than 5mm or 9mm or 15mm thinner. According to a further preferred embodiment of the present invention the foil and/or the hollow housing is/are made of CFC (carbon fiber composite) material, in particular the foil and/or the hollow housing comprises more than 75%-mass CFC material or more than 90%-mass CFC material or more than 95%-mass CFC material or more than 99%-mass CFC material or up to 100%-mass CFC material. The CFC material preferably forms sheets, wherein the hollow housing and/or the foil is/are preferably formed by multiple sheets or a sheet-like structure. Alternatively, the foil and/or hollow housing can be made of molybdenum or can comprise molybdenum.

Thus, the hollow housing and/or the foil and/or wall member respectively SiC growth substrate comprises according to a further preferred embodiment of the present invention carbon fibers. This embodiment is beneficial since carbon fibers can heated to temperatures above 1500°C or above 1800°C or between 1400°C and 2000°C. Furthermore, high tensile loads can be applied to carbon fibers. Carbon fibers have several advantages including high stiffness, high tensile strength, high strength to weight ratio, high chemical resistance, high temperature tolerance and low thermal expansion. The atomic structure of carbon fiber is similar to that of graphite, consisting of sheets of carbon atoms arranged in a regular hexagonal pattern (graphene sheets), the difference being in the way these sheets interlock. Graphite is a crystalline material in which the sheets are stacked parallel to one another in regular fashion. The intermolecular forces between the sheets are relatively weak Van der Waals forces, giving graphite its soft and brittle characteristics.

The hollow housing and/or the foil and/or wall member respectively SiC growth substrate is according to a further preferred embodiment of the present invention formed by a carbon fiber composite material. This embodiment is beneficial since the fiber orientation with carbon fiber composite materials covers at least two directions and therefore allows also compensation forces in multiple directions. An example of a preferred carbon fiber composite material is e.g., SIGRABOND Standard from SGL Carbon GmbH.

The hollow housing and/or the foil and/or wall member respectively SiC growth substrate formed by the carbon fiber composite material is a preferred embodiment of the present invention and preferably has a tensile strength above 50 MPa (cf. DIN IEC 60413/501) and/or a flexural strength above 50 MPa. This embodiment is beneficial since high tensile loads resulting from high temperature differences resulting from thick SiC crusts can be compensated. According to a further preferred embodiment of the present invention a heating unit for non- electrically generation of heat is provided, wherein the heating unit is configured for heating the SiC growth substrate/s to a temperature above 1300°C and preferably between 1300°C and 2000°C or between 1300°C and 1800°C. This embodiment is beneficial since e.g., gas, in particular natural gas, H2 and/or biogas and/or methane, can be burned to generate heat. The flame, which results during burning gas, can be used to directly heat the wall member. Alternatively, the flame can be used to heat a heat transfer medium or to generate a heat transfer medium, which is guided to the wall member for heating the wall member. A heating unit which is based on burning gas causes significant smaller infrastructure cost, since no transistors, transformers, etc. are required. Furthermore, the costs for maintenance are smaller. According to a further preferred embodiment of the present invention the heating unit forms a fluid guide means for guiding fluid heated to a temperature above 1300°C and preferably between 1300°C and 2000°C or between 1300°C and 1800°C for heating the wall member for heating the wall surface section. This embodiment is beneficial since heat distribution can be adjusted in a very precise manner in case a fluid is heated and circulated through a heat guide means, wherein the heat guide means is preferably formed by at least one pipe, wherein the pipe preferably comprises graphite or CFC-material or molybdenum.

According to a further preferred embodiment of the present invention the heating unit forms a fluid guide means for guiding a gas to at least one defined combustion space for burning the guided gas and thereby heating the wall member for heating the wall surface section. This embodiment is beneficial since the wall member can be heated very fast.

A CVD SiC production reactor process chamber, wherein the process chamber is at least surrounded by a bottom wall section, in particular a base plate or base plate wall section, a side wall section and a top wall section, a gas inlet unit for feeding one feed-medium or multiple feed-mediums into a reaction space of the process chamber for generating a source medium, wherein the gas inlet unit is coupled with at least two feed-medium sources, wherein a Si feed medium source is at least coupled with a Chlorosilanes mass flux path for feeding the Chlorosilanes into the process chamber, wherein the Chlorosilanes preferably comprise STC or TCS or consist of STC or TCS separated from the first fluid, and wherein a C feed medium source is configured to provide at least a C-bearing molecule, in particular natural gas, Methane, Ethane, Propane, Butane and/or Acetylene, and wherein a carrier gas medium source provides a carrier gas, in particular H2, at least one SiC growth substrate surface is formed inside the process chamber by a wall surface section, a heating unit for non-electrically generation of heat is provided, wherein the heating unit is configured for heating at least the SiC growth substrate surface to a temperature above 1300°C and preferably between 1300°C and 2000°C or between 1300°C and 1800°C. This solution is beneficial since said CVD SiC production reactor and preferably also at least one further CVD SiC production reactor (preferably of the same type) can be utilized in a method of the present invention.

This solution is also beneficial since the infrastructure costs for electronic components like transformers, transistors, etc. can be significantly reduced. Furthermore, costs for maintenance are also smaller in case the heating unit causes a non-electrically generation of heat.

According to a further preferred embodiment of the present invention the heating unit is at least sectionally surrounded by a wall member forming the wall surface section. This embodiment is beneficial since the heating unit preferably transfers heat via radiation to the wall member. However, it is alternatively or additionally possible that the heating unit contacts the wall member for transferring heat via heat conduction to the wall member.

According to a further preferred embodiment of the present invention the wall surface section is part of the side wall section and/or top wall section or part of a wall member surrounded by the side wall section and top wall section. This embodiment is beneficial since multiple wall sections, in particular facing in different directions, can be heated and used for deposition of SiC. Thus, one or multiple heating unit/s can be operated at the same time to heat different surface sections.

According to a further preferred embodiment of the present invention the heating unit forms a fluid guide means for guiding fluid heated to a temperature above 1300°C and preferably between 1300°C and 2000°C or between 1300°C and 1800°C for heating the wall member for heating the wall surface section. This embodiment is beneficial since the heat distribution can be controlled precisely. Furthermore, the heated fluid stores some heat and allows compensation of gas flow interruption.

According to a further preferred embodiment of the present invention the heating unit forms a fluid guide means for guiding a gas to at least one defined combustion space for burning the guided gas and thereby heating the wall member for heating the wall surface section. This embodiment is beneficial since the temperature of the wall member can be increased rapidly, in particular in less than 5min or less than 2min or less than 1min.

A CVD SiC production reactor process chamber, wherein the process chamber is at least surrounded by a base plate, a side wall section and a top wall section, a gas inlet unit for feeding one feed-medium or multiple feed-mediums into a reaction space of the process chamber for generating a source medium, wherein the gas inlet unit is coupled with at least two feed-medium sources, wherein a Si feed medium source is at least coupled with a Chlorosilanes mass flux path for feeding the Chlorosilanes into the process chamber, wherein the Chlorosilanes preferably comprise STC or TCS or consist of STC or TCS separated from the first fluid, and wherein a C feed medium source is configured to provide at least a C-bearing molecule, in particular natural gas, Methane, Ethane, Propane, Butane and/or Acetylene, and wherein a carrier gas medium source provides a carrier gas, in particular H2, one or multiple SiC growth substrate, in particular more than 3 or 4 or 6 or 8 or 16 or 32 or 64 or up to 128 or up to 256, are arranged inside the process chamber for depositing SiC, wherein each SiC growth substrate comprises: a main body for coupling with a first power connection and a second power connection, wherein the first power connection is configured to conduct power into the main body for heating the main body and wherein the second power connection is configured to conduct electric power conducted via the first power connection into the main body out of the main body, wherein the main body has a main body length (ML), wherein the main body forms a deposition surface for deposition of SiC for growing a SiC crust, wherein the main body comprises carbon fibers, wherein the main body is formed by a carbon fiber composite material wherein the main body formed by the carbon fiber composite material has a tensile strength above 50 MPa and/or a flexural strength above 50 MPa, wherein the main body has at least in sections and preferably along more than 50% of the length of the main body and most preferably entirely a band-like shape, wherein the band like shape forms a cross-section having a width and a depth, wherein width (W) is at least 2 times depth and preferably at least 3 times and highly preferably at least 5 times and most preferably up to or exactly or more than 10 times, wherein width is smaller than 1.5 cm and depth is larger than 3.0 cm wherein each SiC growth substrate is coupled between at least one first metal electrode and at least one second metal electrode for heating the outer surface of the SiC growth substrates or the surface of the deposited SiC to temperatures between 1300°C and 1800°C, in particular by means of resistive heating and preferably by internal resistive heating, wherein the first metal electrodes and the second metal electrodes are preferably shielded from the reaction space. This solution is beneficial since said CVD SiC production reactor and preferably also at least one further CVD SiC production reactor (preferably of the same type) can be utilized in a method of the present invention.

Thus, the physical structure is according to the present invention preferably formed by a carbon fiber composite material. This feature is beneficial since the fiber orientation with carbon fiber composite materials covers at least two directions and therefore allows also compensation forces in multiple directions. An example of a preferred carbon fiber composite material is e.g. SIGRABOND Standard from SGL Carbon GmbH.

Furthermore, the physical structure formed by the carbon fiber composite material preferably has a tensile strength above 50 MPa (cf. DIN IEC 60413/501) and/or a flexural strength above 50 MPa. This feature is beneficial since high tensile loads resulting from high temperature differences resulting from thick SiC crusts can be compensated.

Additionally, the physical structure preferably has at least in sections and preferably along more than 50% of the length of the physical structure and most preferably entirely a band-like shape, wherein the band like shape forms a cross-section having a width W and a depth D, wherein width W is at least 2 times depth D and preferably at least 3 times and highly preferably at least 5 times and most preferably up to or exactly or more than 10 times. This feature is beneficial since the size of the deposition surface is significantly larger compared to a cylindrical shape. Therefore, SiC deposition can be carried out much faster compared to a smaller deposition surface. Width W is preferably smaller than 1.5 cm, in particular smaller than 1 cm or smaller than 0,5 cm, in particular less than 3mm or less than 2mm or less than 1mm, and depth D is larger than 3cm, in particular larger than 5cm or larger than 8cm.

The defined volume section is according to a further preferred embodiment of the present invention preferably formed between a first plane and a second plane, wherein the first plane is perpendicular to the main body length (ML) and wherein the second plane is perpendicular to the main body length (ML), wherein the distance between the first plane and the second plane is at least 5% of the main body length and/or the main body is configured to resist forces generated during growth of the SiC crust having a minimal thickness of at least 3cm for preventing cracking of the main body due to the generated forces.

This embodiment is beneficial since it was found that a temperature difference between the temperature of the deposition surface and the center of the SiC growth substrate increases the larger the distance between the center of the SiC growth substrate and the deposition surface becomes. Due to a large temperature difference physical differences become relevant in view of mechanical stability. Therefore, the present invention provides a solution for compensating physical differences and/or for avoiding physical differences.

The main body is according to a further preferred embodiment of the present invention configured to resist forces generated during growth of the SiC crust having a minimal thickness of at least 3cm or of at least 5cm for preventing cracking of the main body due to the generated forces. This embodiment is beneficial since the temperature differences between the center of the SiC growth substrate and the deposition surface is larger compared to the case in which the thickness of the of the SiC crust 3 cm.

The main body has according to a further preferred embodiment of the present invention at least in sections and preferably along more than 50% of the length of the main body and most preferably entirely a tubular shape, wherein the tubular shape forms a cross-section having an average wall thickness respectively depth of less than 5cm and preferably of less than 2cm and particular preferably of less than 1cm and most preferably of less than 0,5cm, in particular less than 3mm or less than 2mm or less than 1 mm. This embodiment is beneficial since - compared to a solid rod - less energy is needed to heat the deposition surface to the same temperature.

The main body is according to a further preferred embodiment of the present invention a single piece. This embodiment is beneficial since the individual pieces are cheaper compared to a single piece. Furthermore, handling of the individual pieces before forming the SiC growth substrate is also easy.

The main body is according to a further preferred embodiment of the present invention formed by multiple pieces, wherein the multiple pieces are coupled to each other by means of a form closure and/or a force closure. This embodiment is beneficial since the individual pieces are cheaper compared to a single piece. Furthermore, handling of the individual pieces before forming the SiC growth substrate is also easy.

The main body is formed according to a further preferred embodiment of the present invention by multiple pieces, wherein at least some and preferably most and highly preferably all of the multiple pieces are made of a material having a first Coefficient of Thermal Expansion (CTE), wherein the first Coefficient of Thermal Expansion is different to a Coefficient of Thermal Expansion of polycrystalline SiC.

The first Coefficient of Thermal Expansion is at least 0,1 10'⁶ K'¹ and preferably 0,5 10'⁶ K'¹ and most preferably at least 0,1 10'⁶ K'¹ different from the Coefficient of Thermal Expansion of polycrystalline SiC. This embodiment is beneficial since the SiC growth substrate can be made of different material, e.g. tungsten or graphite.

The multiple pieces comprise according to a further preferred embodiment of the present invention at least two pieces of a main piece type and at least one piece of a connecting piece type, wherein the at least two main pieces are coupled by the at least one connecting piece, wherein the pieces of the main piece type have a tubular-like or rod-like or blade-like shape and wherein at least most of the pieces of the main piece type are longer compared to the pieces of the connecting piece type. This embodiment is beneficial since the maximal thermal expansion of each section is below a defined limit even in case a SiC crust of thickness of more than 1cm or preferably more than 3cm or most preferably more than 5cm is formed and even in case the temperature difference between the deposition surface and the center of the SiC growth substrate is more than 10°C or more than 30°C or more than 50°C or more than 100°C or between 50°C and 400°C, in particular between 70°C and 250°C.

The length of each of the at least two pieces of the main piece type is according to a preferred embodiment of the present invention below 100cm and above 5cm and preferably below 90cm and above 10cm and particular preferably below 85cm and above 15cm and most preferably below 80cm and above 20cm.

At least two pieces of the pieces of the main piece type and preferably most of the pieces of the main piece type and most preferably all of the pieces of the main piece type are according to a preferred embodiment of the present invention made of graphite.

A first piece of the at least two pieces of the main piece type has according to a preferred embodiment of the present invention a first central axis and a second piece of the at least two pieces of the main piece type has a second central axis, wherein the first central axis and the second central axis are arranged parallel to each other and highly preferably not coaxial. Highly preferably first central axis and the second central axis are arranged in a distance to each other of more than 5cm and preferably of more than 8cm and particular preferably of more than 12cm and most preferably of more than 15cm or between 10cm and 30cm, in particular between 11cm and 25cm or between 12cm and 20cm. This embodiment is beneficial since the thermal expansion of the individual pieces is decoupled from each other.

The main body forms according to a further preferred embodiment of the present invention a II- shape. This embodiment is beneficial since the electrodes can be arranged on one side respectively in one wall member respectively bottom member. The at least one first metal electrode and at least one second metal electrode are according to a further embodiment of the method according to the invention or according to a further embodiment of one or multiple of the herein disclosed CVD SiC production reactor/s connected to an alternating current source, wherein the alternating current source is configured to set up a frequency of the alternating current above 5Hz or preferably above 20Hz or highly preferably above 50Hz or most preferably above 500Hz or up to 5000Hz, in particular up to 2000Hz or up to 1000Hz or up to 500kHz or up to 2MHz.

This is beneficial, since due to the alternating current the electric power is guided along the outer surface of the growing SiC and therefore heats the center less compared to DC. This is beneficial since the temperature in the center is preferably below the temperature of the outer surface. This is highly beneficial to cause a homogeneous temperature profile between the center and the outer surface, thus the temperature difference between the outer surface and the center is preferably below 300K and more preferably 200K and particular preferably below 100K and most preferably below 50K. This is beneficial to grow the SiC with a low level of tensions to avoid cracking of the SiC.

The step of providing the vent gas mixture respectively the step of operating the CVD SiC production providing the vent gas mixture takes place according to a preferred embodiment of the present invention in the same facility and parallel to respectively at least temporarily at the same time the generating of Chlorosilanes inside the reactor chamber takes place.

The fourth fraction of the vent gas mixture that is forwarded into the reactor chamber comprises according to a preferred embodiment of the present invention more than 0.1 or 0.3 or 0.5 or 0.8 or 1 mass percent and highly preferably more than 2 or 3 or 4 or 5 mass percent and most preferably more than 10 mass percent of the mass sum of all vent gas mixture fractions which are forwarded into the reactor chamber.

The mass content of carbon in all vent gas mixture fractions forwarded into the reactor chamber is according to a preferred embodiment of the present invention larger than 1ppma or larger than 50ppma and preferably larger than 100ppma or larger than 300 ppma or larger than 500 ppma or larger than 700 ppma or larger than 900 ppma or larger than 1000 ppma and particular preferably larger than 3000 ppma or larger than 5000 ppma or larger than 7000 ppma most preferably larger than 10.000 ppma.

The above-mentioned object is also solved by a system according to claim 49. System comprising a CVD SiC production reactor , in particular as described in any of claims 27 to 31 or as described in any of claims 32 to 36 or as described in any of claims 37 to 48, for providing a vent gas mixture and for producing SiC and a bed reactor, in particular a fixed bed reactor or a fluidized bed reactor, for generating Chlorosilanes by reacting at least one fraction of the vent gas mixture and Si, wherein further fractions of the vent gas mixture preferably at least comprise a C-bearing molecule, in particular methane, and wherein Si is provided as solid inside the bed reactor and a separating unit, in particular a distillation column, for separating one or multiple metals, in particular B, Al, Fe and/or P, from generated Chlorosilanes, in particular STC and/or TCS. The at least one fraction of the vent gas mixture preferably consists of the second fraction and the third fraction of the vent gas mixture.

The above-mentioned object is also solved by a method for the production of SiC according to claim 49. Said method preferably comprises at least the steps:

Providing a vent gas mixture, wherein the vent gas mixture is preferably generated during SiC production and highly preferably generated during CVD SiC production,

Generating Chlorosilanes by reacting at least one fraction of the vent gas mixture and Cl (chlorine), wherein the at least one fraction of the vent gas mixture reacting with Cl is TCS, wherein further fractions of the vent gas mixture at least comprise H2 and methane, wherein Cl is provided inside the bed reactor, Forwarding the Chlorosilanes and the further fraction of the vent gas mixture to a separating unit for separating the Chlorosilanes and the further fraction of the vent gas mixture into a first fluid and into a second fluid, wherein the first fluid comprises the Chlorosilanes, wherein a first storage and/or conducting element for storing or conducting the first fluid is part of the separating unit or coupled with the separating unit and wherein a second storage and/or conducting element for storing or conducting the second fluid is part of the separating unit or coupled with the separating unit, Forwarding at least the Chlorosilanes into a process chamber of the CVD SiC production reactor, and Forwarding at least one C-bearing molecule into the CVD SiC production reactor, Producing SiC inside the process chamber of the CVD SiC production reactor by depositing Si from the Chlorosilanes and C from the at least one C-bearing molecule on at least one deposition surface.

The above-mentioned object is also solved by a system according to claim 51. Said system preferably comprises a CVD SiC production reactor, in particular as described in any of claims 27 to 31 or as described in any of claims 32 to 36 or as described in any of claims 37 to 48, for providing a vent gas mixture and for producing SiC and a bed reactor, in particular a fixed bed reactor or a fluidized bed reactor, for generating Chlorosilanes by reacting at least one fraction of the vent gas mixture and Cl, wherein TCS is provided as one fraction of a vent gas provided by the CVD SiC production reactor, wherein the further fractions of the vent gas mixture at least comprise H2 and methane and wherein Cl (chlorine) is provided inside the bed reactor.

It is possible to use the term “elements” in exchange to “substances” or “element” in exchange to “substance”.

Further advantages, objectives and features of the present invention are explained with reference to the following description of accompanying drawings, in which the device(s) according to the invention are shown by way of example. Components or elements of the device according to the invention, which at least substantially correspond in the figures with respect to their function, can be marked with the same reference signs, whereby these components or elements do not have to be numbered or explained in all figures.

Individual or all representations of the figures described in the following are preferably to be regarded as construction drawings, i.e. the dimensions, proportions, functional relationships and/or arrangements resulting from the figure or figures preferably correspond exactly or preferably substantially to those of the device according to the invention or the product according to the invention or the method according to the invention.

Therein show:

Fig. 1-8 schematically different setting of a system according to the present invention, Fig. 9 schematically a first example of a CVD reactor according to the present invention,

Fig. 10 schematically a second example of a CVD reactor according to the present invention,

Fig. 11 schematically a third example of a CVD reactor according to the present invention,

Fig. 12a-g schematically examples of SiC growth substrates, in particular of the CVD reactors of Fig. 9, 10 or 11 ,

Fig. 13a-e schematically examples of SiC growth substrates, in particular of the CVD reactors of Fig. 9, 10 or 11 ,

Fig. 14a/b schematically a blade shaped example of a SiC growth substrates, in particular of the CVD reactors of Fig. 9, 10 or 11 , Fig. 14c/d schematically a tube-shaped example of a SiC growth substrates, in particular of the CVD reactors of Fig. 9, 10 or 11 ,

Fig. 15a-c schematically examples of growth substrates having a crack-free area and Fig. 15d schematically an example of a cross-sectional view of a rod-shaped growth substrate and

Fig. 16a-17d schematically examples of carbon fiber composite elements.

Fig. 18a schematically an example of CVD reactor, wherein heat generation results from conducting electric energy through a SiC growth substrate to heat the SiC growth substrate by resistant heating,

Fig. 18b schematically shows an example of the present invention, wherein a wall is heated on one side by means of a flame and wherein the other side of said wall is arranged inside a reaction space or forms a reaction space,

Fig. 19a schematically a cross-sectional view of a CVD reactor according to the present invention,

Fig. 19b schematically a cross-sectional view of another CVD reactor according to the present invention,

Fig. 20 schematically an example of a further CVD reactor design according to the present invention,

Fig. 21a schematically an example of a gas guide for guiding a gas to be burned to one or multiple combustion outlet/s,

Fig. 21 b schematically a cross-sectional view of a further CVD reactor according to the present invention,

Fig. 21c the gas guide of fig. 21a, wherein flames burning the conducted gas are illustrated schematically,

Fig. 21 d schematically another cross-sectional of the CVD reactor of fig. 21b,

Fig. 22 schematically shows another type of heating unit, wherein the burned gases are guided through a pipe system to heat the SiC growth substrate/s,

Fig. 23a schematically shows a further type of heating unit, wherein a fluid is heated which is guided in a pipe, wherein another substance, in particular gas, is burned to provide heat for heating the fluid inside said pipe,

Fig. 23b schematically shows an example of a heat transfer arrangement for transferring heat from the burned gas to the fluid, in particular gas and/or liquid, inside the Pipe,

Fig. 23c schematically that the SiC growth substrate can have straight sections connected via one or more curved sections and can act as fluid, in particular gas and/or liquid, guide means,

Fig. 24a schematically a hollow housing that can act as SiC growth substrate or that can hold a SiC growth substrate, Fig. 24b schematically the hollow housing of Fig. 24a on an example of a holding and/or carrying structure,

Fig. 24c schematically a SiC growth substrate formed as foil, wherein the foil is positioned on the hollow housing,

Fig. 24d schematically a side view of the hollow housing of Fig. 24a and a heating unit, wherein the heating unit can be covered by the hollow housing,

Fig. 24e schematically a cross-section view showing SiC grown on a foil arranged on the hollow housing,

Fig. 25a schematically a further hollow housing,

Fig. 25b schematically an arrangement having a carrying member, in particular a rod-like element or a rod, positioned on top of the hollow housing for holding at least one foil,

Fig. 25c schematically a cross-section view showing SiC grown on a foil arranged on the hollow housing,

Fig. 26a schematically a further example of a CVD reactor according to the present invention,

Fig. 26b schematically the CVD according to Fig. 26a, wherein the CVD reactor comprises a cooling unit for cooling the housing,

Fig. 26c schematically a cross-sectional view of a further CVD reactor, wherein growth faces of multiple SiC growth substrates are parallel to each other or at least significantly overlay each other,

Fig. 26d schematically a side view of a SiC growth substrate respectively of a hollow housing, wherein one growth face faces into a first direction and a second growth face faces into a second direction,

Fig. 26e schematically a side view of a SiC growth substrate respectively of a hollow housing, wherein one growth face faces into a first direction and a second growth face faces into a second direction, wherein the second direction is aligned in an angle with respect to direction OD1 ,

Fig. 27 schematically a further CVD reactor design, wherein the individual Sic growth substrates are aligned with respect to each other,

Fig. 28a schematically a further CVD reactor design, wherein the individual SiC growth substrates overlap the neighboring SiC growth substrates,

Fig. 28b schematically shows a further example of the design of a SiC growth substrate, in particular of a hollow housing,

Fig. 28c schematically enhanced overlap in circular reactor design,

Fig. 29 schematically an example of a section of the CVD reactor according to fig. 27 or 28c in a perspective view. Fig. 1 shows an example of a system according to the present invention. Said system comprises at least one CVD SiC reactor 850 (reference numbers 850a and 850b in case of multiple CVD SiC reactors) and at least on reactor, in particular a bed reactor 2416, for reaction Si and one or more than one fractions of the vent gas of the CVD SiC reactor 850 to produce Chlorosilanes, in particular STC and/or TCS. It is possible to forward Chlorosilanes produced inside the reactor 2416 to the CVD SiC reactor 850a that provided the vent gas for the Chlorosilane production. Additionally or alternatively it is possible to forward the generated Chlorosilanes to another CVD SiC reactor 850b.

According to the present invention a CVD SiC reactor 850a/b preferably comprises at least one process chamber 856a/b and at least one and preferably multiple SiC growth substrates 857a/b arranged respectively arrangeable inside the CVD SiC reactor 850a/b. The CVD SiC reactor 850/a/b preferably comprises at least or exactly one vent gas outlet 216, wherein said vent gas outlet 216 is preferably directly or indirectly coupled via a vent gas conduit 2400 with a gas inlet 2417 of reactor 2416. Reactor 2416 comprises a reactor chamber 2419, wherein solid Si 2398 is provided inside the reactor chamber 2419. The solid Si 2398 is preferably provided in form of particles.

The solid Si 2398 particles preferably have a length between 1mm and 50mm and preferably between 1mm and 40mm and highly preferably between 1mm and 15mm and most preferably between 1mm and 5mm or 10mm. The solid Si 2398 is preferably crushed by means of a crusing device (not shown). The crushing device can be part of the present system. The crushing device is preferably a jaw crusher or a water pulse crusher. The crushing device preferably continuously provides Si particles. This also applies to following figures.

With respect to fig. 1 and the remaining figures it must be noted that fluid outlet 216 and fluid inlet 2417 are schematically shown only, other fluid inlets and/or outlets do not have to be explicitly mentioned and/or shown.

The reactor 2416 preferably outputs at least Chlorosilanes 2394. The arrows indicate that the Chlorosilanes 2394 can be fed into CVD SiC reactor 850a and/or 850b.

Additionally the dotted arrow shows that further substances can be optionally fed into the CVD SiC reactor 850a (the same applies to the further CVD SiC reactor 850b). The further substances can be e.g. a c-bearing molecule, in particular CH4 (methane), and/or H2 (hydrogen). It is also possible to feed the further substance/s via the same inlet via which the Chlorosilanes are fed into the CVD SiC reactor 850. According to a further preferred embodiment of the present invention an exchange device 2460 is optionally provided for exchanging 3-15% Vol. of the second fluid 626. The second fluid 626 preferably comprises H2, Methane, HCI, Chlorosilane, wherein the ration of the composition ((H2:Methane:HCI:Chlorosilane) of the second liquid is preferably between 3:1 :0, 1 :0,1 Vol. and 7:1:0, 1 :0,1 Vol. it is alternatively possible to provide an absorber device (cf. fig. 8 ref. 2436) for removing further impurities, e.g. phosphor, dust and/or metal/s. Both the exchange device 2460 and the absorber device 2436 are optional but could be also part of the following figures. With respect to the exchange device 2460 it is also possible to establish that functionality by removing 3-15% Vol of the second fluid 626 and adding the same amount of the removed substances via one or more other input devices, in particular input path 2462. Thus, it is possible that the exchange device 2460 is only a removing device for removing 3-15% Vol. of the second fluid 626. This also applies to following figures.

Fig. 2 shows a further detailed example of the system according to the present invention. According to fig. 2 a separating unit 602 is provided downstream the reactor 2416. The separating unit 602 is preferably configured for separating the generated Chlorosilanes 2394 and the third fraction 2401 of the vent gas mixture 2400 and the fourth fraction of the vent gas mixture 2400 into a first fluid 624 and into a second fluid 626. The first fluid 624 is preferably fed to a storage unit, in particular a first fluid storage unit 2412, or to the CVD SiC reactor 850a and/or to another CVD SiC reactor 850b. The second fluid 626 is preferably fed to another storage unit, in particular a second fluid storage unit 2414, or to the CVD SiC reactor 850a and/or to another CVD SiC reactor 850b.

Additionally the separating unit 602 could be configured according to a further preferred embodiment for reducing the amount of metal impurities within the generated Chlorosilanes below 20ppmw and preferably below 10ppmw and highly preferably below 5ppmw and most preferably below 1ppmw. The removed metal impurities are preferably feedable to a waste storage 2426.

Additionally the dotted arrow 2462 shows that further substances can be optionally fed into the CVD SiC reactor 850a (the same applies to the further CVD SiC reactor 850b). The further substances can be e.g. a c-bearing molecule, in particular CH4 (methane), and/or H2 (hydrogen). Additionally, it is possible to feed the Chlorosilanes and the second fluid via a common gas inlet into the CVD SiC reactor. It is also possible to feed the further substance/s via the same inlet via which the Chlorosilanes and/or the second liquid is/are fed into the CVD SiC reactor 850. This also applies to following figures. Fig. 3 shows a further detailed example of the system according to the present invention. The further CVD SiC reactor 850b is not shown in this figure, however it has to understood that the treated vent gas fraction could be additionally or alternatively provided to such a further CVD SiC reactor 850b in case such a further CVD SiC reactor 850b is desired (this also applies to the further figures).

Even if a waste storage 2426 is provided after the metal removing device 2425 it is still possible that separating unit 602 is also connected to said waste storage 2426 or to another waste storage.

The further separating unit 612 preferably comprises a metal removing device 2425, wherein the metal removing device 2425 preferably removes remaining metal impurities from the first fluid 624. The first fluid 624 is preferably fed from the metal removing device 2425 to a STC and TCS dividing device 2421. Alternatively, the first fluid could be fed into the CVD SiC reactor 850a. STC is preferably stored in a STC storage 2422 and TCS is preferably stored in a TCS storage 2424.

The further separating unit 612 could be configured according to a further preferred embodiment for reducing the amount of metal impurities, in particular B, Al, P, Ti, V, Fe and/or Ni, within the first fluid 624, in particular the Chlorosilanes below 20ppmw, in particular of one or multiple or all of the metals B, Al, P, Ti, V, Fe and/or Ni, and preferably below 10ppmw, in particular of one or multiple or all of the metals B, Al, P, Ti, V, Fe and/or Ni, and highly preferably below 5ppmw, in particular of one or multiple or all of the metals B, Al, P, Ti, V, Fe and/or Ni, and most preferably below 1ppmw, in particular of one or multiple or all of the metals B, Al, P, Ti, V, Fe and/or Ni. The removed metal impurities are preferably feedable to a waste storage 2426.

TCS and/or STC can be fed from STC storage 2422 and/or TCS storage 2424 into the CVD SiC reactor 850. Volume or mass of the STC and/or TCS which is fed into the CVD SiC reactor is preferably controlled, in particular by means of a mass flux controller respectively one mass flux controller for STC and /or one mass flux controller for TCS.

Fig. 4 schematically indicates that the separating unit 602 is not or not directly coupled with a waste storage 2426, in particular it is possible that the separating unit 602 is not configured for separating or removing metal impurities. Alternatively it is possible to remove the amount of metal impurities within the generated Chlorosilanes only with the further separating unit 612 below 20ppmw and preferably below 10ppmw and highly preferably below 5ppmw and most preferably below 1 ppmw.

Fig. 5 schematically shows that a Si supply unit 2432 can be part of the inventive system. The Si supply unit 2432 is preferably a Si storage for storing and providing Si particles. Alternatively the Si supply unit 2432 can be a crushing device, in particular a jaw crusher and/or a water pulse crusher. However, it is also possible that the Si supply unit 2432 comprises a Si storage for storing and providing Si particles and a crusher device, in particular a jaw crusher and/or a water pulse crusher, for crushing Si.

Fig. 6 schematically shows that - additionally to the Si supply unit 2432- a HCI supply unit 2434 can be provided for supplying HCI, in particular from a HCI storage, into the reactor 2416. It is also possible that the HCI supply 2434 is present in case no Si supply unit 2432 is provided. The HCI supply unit 2434 can be used to add the amount of HCI removed from the system, in particular removed by the exchange device 2460 (cf. Fig. 2) respectively removing device.

Fig. 7 shows Si supply unit 2432, HCI supply unit 2434 and a vent gas storage unit 2450 coupled to the reactor 2416. It has to be understood that the Si supply unit 2432, the HCI supply unit 2434 and the vent gas storage unit 2450 are optional. However, it is possible to have one of them or two of them or all of them present according to the invention. The vent gas storage unit 2450 is configured to store vent gas and to provide vent gas, in particular above the condensation temperature of the vent gas. This embodiment is beneficial since during start up and/or shut down of the CVD SiC reactor 850 a continuous vent gas supply to the reactor 2416 can be established. Thus, the production of Chlorosilanes can take place even if the CVD SiC reactor does not provide vent gas.

Additionally or alternatively, HCI can be supplied during start up and/or shut down of the CVD SiC reactor 850. Since HCI reacts with Si to Chlorosilanes.

Additionally or alternatively Chlorosilanes, in particular TCS, are supplied to the reactor 2416, in particular from TCS storage 2422.

A combined supply of Chlorosilanes, in particular TCS, preferably from TCS storage 2422, and HCI, preferably from HCI supply 2434, to the reactor 2416 is also possible.

Furthermore, in the case of HCI, vent gas or Chlorosilane supply further Chlorosilanes are produced. It is further possible to supply a c-bearing molecule, in particular methane, and H2 into the reactor, in particular for holding the reactor in an idle state. It is herewith beneficial to also heat the reactor 2416, in particular the reactor chamber 2419.

All that optional or additional supply steps are beneficial since the reactor 2416 does not have to shut down during start up or shut down of the CVD SiC reactor.

Reference number 2428 indicates a paused/reduced vent gas mixture feeding from the CVD SiC reactor e.g. due to start up or shut down phase.

Fig. 8 shows that the second fluid 626 can be fed through an absorber device 2436 for removing phosphor, dust and/or metal impurities. The removed substances are preferably fed into a washer 2438 and the resulting substances can be burned in a combustion unit 2440, in particular a flare. The combustion unit 2440 is preferably used to provide heat for heating the reactor 2416, in particular in case no exothermic reaction takes place inside the reactor 2416 or in case the reactor is in a start up phase.

The systems described with respect to Fig. 1 to 8 are able to carry out a preferred method of the present invention for the production of SiC. Said method preferably comprises at least the steps:

Providing a vent gas mixture 2400, wherein the vent gas mixture 2400 is preferably generated during SiC production and highly preferably generated during CVD SiC production, wherein at least a first fraction of the vent gas mixture is HCI, wherein a second fraction of the vent gas mixture consists of vent gas Chlorosilanes, in particular STC and/or TCS, wherein a third fraction 2401 of the vent gas mixture 2400 comprises or consists of H2 2402 and wherein a fourth fraction of the vent gas mixture 2400 comprises or consists of at least one C-bearing- molecule, in particular methane, 2404. The method preferably also comprises a step of providing solid Si inside a reactor chamber, wherein the solid Si comprises metal impurities of more than lOOOppmw. The method preferably also comprises a step of forwarding at least the second fraction of the vent gas mixture 2400 and the third fraction of the vent gas mixture 2400 into the reactor chamber and/or the first fraction of the vent gas mixture 2400. The method preferably also comprises a step of generating Chlorosilanes inside the reactor chamber by reacting the second fraction of the vent gas mixture, in particular STC and/or TCS, and the third fraction 2401 of the vent gas mixture 2400 and the solid Si and/or by reacting the first fraction of the vent gas mixture 2400 and the solid Si. The method preferably also comprises the steps: Forwarding at least the generated Chlorosilanes 2394 into a process chamber 856a of the CVD SiC production reactor 850a, and forwarding at least one C-bearing molecule into the CVD SiC production reactor 850a, and producing SiC inside the process chamber 856a of the CVD SiC production reactor 850a by reacting the generated Chlorosilanes and C from the at least one C-bearing molecule on at least one deposition surface. Alternatively the method preferably also comprises the steps: Forwarding at least the generated Chlorosilanes 2394 into a process chamber 856b of a further CVD SiC production reactor 850b, and forwarding at least one C-bearing molecule into the further CVD SiC production reactor 850b, and producing SiC inside the process chamber 856 of the further CVD SiC production reactor 850b by reacting the generated Chlorosilanes and C from the at least one C-bearing molecule on at least one deposition surface.

With respect to the before mentioned figures the process according to the present invention can be divided into a phase “during operation of the CVD SiC reactor” and a phase “ during start up or shutdown”. By means of example, both phases are described in the following with additional or alternative features (with respect to the description of Fig. 1-8).

During operation of the SiC CVD reactors under deposition of SiC, the process gas preferably comprises or consisting of STC, TCS, H2, CH4 and HCI. The process gas leaves the SiC CVD reactor chamber as “vent gas” and is preferably cooled down to a temperature of about 200°C, in particular by means of heat exchangers. This vent gas stream remains completely in gas phase. The complete vent gas stream is then continuously fed into the reactor, in particular bed reactor and preferably fixed bed reactor. The reactor preferably comprises a steel vessel, in particular with dimensions of more than 5m height and preferably of 8 m height or of more than 8m height and highly preferably of 10m or more than 10m height, and a diameter of 1m or of more than 1 m, in particular of 1 ,5m or of more than 1 ,5m or preferably of 2m or of more than 2m or between 1 ,7m and 2,3m. In the reactor there is a bed of silicon. The vent gas is introduced in the lower part of the reactor, which allows the vent gas to flow optimally through the silicon bed. The contact of the gas phase with silicon leads to an exothermic chemical reaction with the formation of a new STC, TCS, H2, CH4 and HCI gas mixture, in which the HCI content is significantly reduced and the chlorosilane content, comprising or consisting of STC and/or TCS, is increased. The silicon bed is preferably kept at a temperature of 400-450°C and a pressure between 1 ,2 and 2 bar, in particular 1.5 bar, which ensures optimum HCI conversion. The proportion of chlorosilanes in gas phase increases in the reactor with degradation of silicon. To cool the reactor chamber in the reactor, the reactor is preferably operated with a cooling water jacket. Furthermore, liquid chlorosilane mixture of STC and/or TCS can be introduced in the upper part of the reactor. On the one hand, this process serves to cool the reaction chamber and thus to control the reaction temperature, and on the other hand, metal chloride constituents, such as ferric chloride and aluminum chloride, are thereby transferred from the gas phase to a solid particle form.

After vent gas leaves the reactor, the solid components formed are preferably separated from the gaseous fluid, in particular by means of a solids separation system preferably using cyclones and/or filters.

In addition, a downstream gas scrubber can be provided, which is preferably operated with liquid chlorosilane. This embodiment is beneficial since it ensures that even very small solid components can be washed out of the gas stream, thus further reducing the metal chloride content of the fluid.

After separation of the solid components from the gas stream, the condensable components of the process gas are preferably liquefied by cooling. The liquid phase is preferably separated and contains mainly the chlorosilanes STC and TCS as well as dissolved portions of HCI, H2 and CH4 and trace components of chlorosilane boilers, such as hexachlorodisilane, and metal chlorides.

The gas phase preferably comprises or consists predominantly of H2, CH4 and minor amounts of HCI, STC and TCS.

For further purification of the chlorosilanes from metal chlorides and separation into the individual components STC and TCS, the liquid phase is preferably subjected to one or multiple further distillation steps and purified STC and/or TCS is/are collected individually in tanks. The gas phase is preferably returned to the CVD SiC reactor or another CVD SiC reactor or a storage unit, in particular a tank, after separation of liquid components.

Preferably no process gas leaves the SiC CVD reactor chamber during start up or shut down phases of the SiC CVD reactor/s. No CVD SiC reactor vent gas flow can be continuously introduced into the reactor if taken directly from the CVD SiC reactor.

The reactor preferably is a steel vessel with dimensions of 10m in height and a diameter of about 2m. In the reactor 2416 there is a bulk of silicon 2398. Gas comprising or consisting mainly of H2 and CH4 and small amounts of STC, TCS and HCI is introduced in the reactor, in particular in the lower part of the reactor 2416. The bulk silicon 2398 is preferably maintained at a temperature of 400-450°C and a pressure of 1.5 bar. Due to the lack of exothermic reaction between silicon, HCI and chlorosilanes, to heat the bulk of silicon 2398 in the reactor, the gas is preferably heated up to 800°C or to a temperature between 700°C and 900, in particular to a temperature between 750°C and 850°C, in particular at the gas inlet or prior to the gas inlet. After vent gas leaves the reactor, the solid components formed are preferably separated from the gaseous fluid, in particular by means of a solids separation system preferably using cyclones and/or filters.

For further purification of the chlorosilanes from metal chlorides and separation into the individual components STC and TCS, the liquid phase is preferably subjected to one or multiple further distillation steps and purified STC and/or TCS is/are collected individually in tanks.

The gas phase is preferably returned to the CVD SiC reactor or another CVD SiC reactor or a storage unit, in particular a tank, after separation of liquid components.

Fig. 9 shows an example of a manufacturing device 850 for producing SiC material, in particular 3C-SiC material. This device 850 comprises a first feeding device 851, a second feeding device 852 and a third feeding device 853. The first feed device 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 e.g. silanes/chlorosilanes of the general composition SiH4-mClm or organochlorosilanes of the general composition SiR4-mClm (where 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, e.g. hydrocarbons or chlorohydrocarbons, preferably with a boiling point < 100 °C, particularly preferably methane. 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 H2, respectively, or mixtures of hydrogen and inert gases.

The reference sign 854 indicates a mixing device or a mixer by which the source fluids and/or the carrier fluid can be mixed with one another, in particular in predetermined ratios. The reference sign 855 indicates an evaporator device or an evaporator by which the fluid mixture which can be supplied from the mixing device 854 to the evaporator device 855 can be evaporated.

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

The reference sign 858 indicates a temperature measuring device, which is preferably provided for determining the surface temperature of the deposition element 857 and is preferably connected to a control device (not shown) by data and/or signal technology.

The reference sign 859 indicates an energy source, in particular for introducing electrical energy into the separating element 857 for heating the separating element. The energy source 859 is thereby preferably also connected to the control device in terms of signals and/or data.

Preferably, the control device controls the energy supply, in particular power supply, through the deposition element 857 depending on the measurement signals and/or measurement data output by the temperature measurement device 858. The energy source 859 preferably provides alternating current.

Furthermore, a pressure holding device is indicated by the reference sign 860. The pressure holding device 860 can preferably be implemented by a pressure-regulated valve or the working pressure of a downstream exhaust gas treatment system.

Fig. 10 shows the CVD unit respectively CVD reactor respectively SiC production reactor, in particular SiC PVT source material production reactor, 850 of one preferred embodiment of the present invention. The CVD unit respectively CVD reactor respectively SiC production reactor, in particular SiC PVT source material production reactor, 850 preferably comprises a fluid, in particular oil or water, cooled steel upper housing 202 or bell jar which seals, in particular by means of one or multiple gaskets, against a preferably fluid, in particular oil or water, cooled lower housing 2040 or base plate creating a deposition chamber respectively process chamber 856 which can be pressurized preferably to at least 6 bar, in particular to a pressure between 2 bar and 15bar. The feed gas mixture 1160 preferably enters the deposition chamber respectively process chamber 856 through a plurality of feed gas inlets 2140 and the vent gas 2120 preferably exists through the gas outlet unit respectively vent gas outlet 216. Inside the deposition chamber preferably a plurality of resistively self-heated deposition substrates respectively SiC growth substrate 857 preferably made of graphite or silicon carbide or metal are provided which are connected to chucks 208 which are preferably made of graphite. The chucks 208 are in turn connected to water cooled electrodes 206 preferably made of copper which pass through the baseplate so that they can be connected to an external source of electrical power. The deposition substrates respectively SiC growth substrate 857 are preferably arranged as pairs via cross members 203 to complete an electrical circuit for resistive heating.

The purpose of the chucks 208 is to create a temperature gradient between the electrodes 206 which are in a temperature range of preferably between 850 and 400°C and the deposition substrate respectively SiC growth substrate 857 which is preferably in temperature range of 1300 and 1600°C. The chuck 208 preferably achieves this by having a continuously reducing current flow cross section area resulting in higher and higher resistive heating. Thus, the chuck

208 preferably has a conical shape. In this manner the starting point for the deposition of CVD SiC crust 211 can be controlled preferably to a point for example midway up the chuck 208 such that the final deposition substrate respectively SiC growth substrate 857 with the deposited CVD SiC crust 211 has a structurally strong connection at the bottom and will not break or fall over. The plurality of feed gas inlets 2140 is preferably designed to create a turbulent gas flow pattern inside the deposition chamber respectively process chamber 856 so as to maximize the contact of fresh feed gas with the surface of the CVD SiC crust 211 being deposited on the deposition substrates respectively SiC growth substrate 857. Additionally, or alternatively it is possible to provide a gas turbulence generating apparatus, in particular inside the process chamber. The gas turbulence generating apparatus can be a ventilator or circulator pump. This ensures that a minimum excess of feed gas mixture 1160 is used to produce a given quantity of CVD SiC crust 211. The vent gas 2120 which contains unreacted feed gas mixture as well as altered Si- bearing gas and HCI gas is forced out of the deposition chamber respectively process chamber 856 through the vent gas outlet by the incoming feed gas mixture 1160.

Fig. 11 shows examples of the temperature and pressure control methods for the CVD unit. A temperature control unit respectively temperature measuring device 858 is positioned such that to measure the temperature of the CVD SiC crust 211 along the temperature measurement path

209 preferably through the sight glass 213 which is preferably fluid, in particular oil or water, cooled. The temperature control unit respectively temperature measuring device 858 preferably measures the temperature of the surface of the CVD SiC crust and sends a signal to the power supply unit respectively energy source 859 to increase or decrease power to the deposition substrates respectively SiC growth substrate 857 depending on whether the temperature is below or above the desired temperature respectively. The power supply unit respectively energy source 859 is wired to the fluid, in particular oil or water-cooled electrodes 206 and adjusts voltage and/or current to the fluid, in particular oil or water, cooled electrodes 206 accordingly. The energy source 859 preferably provides alternating current. The deposition substrates respectively SiC growth substrate 857 are wired in pairs and have connecting cross members at the top so as to form a complete electrical circuit for the flow of current.

Pressure inside the deposition chamber respectively process chamber 856 is adjusted by means of a pressure control unit respectively pressure maintaining device 860 which senses the pressure and decreases or increases the flowrate of vent gas 2120 from the deposition chamber respectively process chamber 856.

Thus, as shown in fig. 10 and 11 the SiC production reactor 850 according to the present invention preferably comprises at least a process chamber 856, wherein the process chamber 856 is at least surrounded by a base plate 862, a side wall section 864a and a top wall section 864b. the reactor 850 preferably comprises a gas inlet unit 866 for feeding one feed-medium or multiple feed-mediums into a reaction space of the process chamber 856 for generating a source medium inside the process chamber 856. The base plate 862 preferably comprises at least one cooling element 868, 870, 880, in particular a base cooling element, for preventing heating the base plate 862 above a defined temperature and/or wherein the side wall section 864a preferably comprises at least one cooling element 868, 870, 880, in particular a bell jar cooling element, for preventing heating the side wall section 864a above a defined temperature and/or wherein the top wall section 864b preferably comprises at least one cooling element 868, 870, 880, in particular a bell jar cooling element, for preventing heating the top wall section 864b above a defined temperature. The cooling element 868 can be an active cooling element 870, thus the base plate 862 and/or side wall section 864a and/or top wall section 864b preferably comprises a cooling fluid guide unit 872, 874, 876 for guiding a cooling fluid, wherein the cooling fluid guide unit 872, 874, 876 is configured limit heating of the base plate 862 and/or side wall section 864a and/or top wall section 864b to a temperature below 1000°C. It is additionally possible that a base plate and/or side wall section and/or top wall section sensor unit 890 is provided to detect the temperature of the base plate 862 and/or side wall section 864a and/or top wall section 864b and to output a temperature signal or temperature data. The at least one base plate and/or side wall section and/or top wall section sensor unit 890 can be arranged as part of a surface or on a surface inside the process chamber, in particular on a surface of the base plate 862 or the side wall section 864a or the top wall section 864b.

Additionally or alternatively it is possible to provide one or more base plate and/or side wall section and/or top wall section sensor unit/s 890 inside the base plate 862 or inside the side wall section 864a or inside the top wall section 864b. Additionally or alternatively it is possible to provide a cooling fluid temperature sensor 820 to detect the temperature of the cooling fluid guided through the cooling fluid guide unit 870. A fluid forwarding unit 873 can be provided for forwarding the cooling fluid through the fluid guide unit 872, 874, 876, wherein the fluid forwarding unit 873 is preferably configured to be operated in dependency of the temperature signal or temperature data provided by the base plate and/or side wall section and/or top wall section sensor unit 890 and/or cooling fluid temperature sensor 892. The cooling fluid can be oil or preferably water, wherein the water preferably comprises at least one additive, in particular corrosion inhibiter/s and/or antifouling agent/s (biocides).

Additionally, or alternatively the cooling element 868 is a passive cooling element 880. Thus, the cooling element 868 can be at least partially formed by a polished steel surface 865 of the base plate 862, the side wall section 864a and/or the top wall section 864b, preferably by a polished steel surface 865 of the base plate 862, the side wall section 864a and the top wall section 864b. The passive cooling element 868 can be a coating 867, wherein the coating 867 is preferably formed above the polished steel surface 865 and wherein the coating 867 is configured to reflect heat. The coating 867 can be a metal coating or a comprises metal, in particular silver or gold or chrome, or can be an alloy coating, in particular a CuNi alloy. The emissivity of the polished steel surface 865 and/or of the coating 867 is 0.3, in particular below 0.1 and highly preferably below 0.03.

The base plate 862 can comprise at least one active cooling element 870 and one passive cooling element 880 for preventing heating the base plate 862 above a defined temperature and/or the side wall section 864a can comprise at least one active cooling element 870 and one passive cooling element 880 for preventing heating the side wall section 864a above a defined temperature and/or the top wall section 864b can comprises at least one active cooling element 870 and one passive cooling element 880 for preventing heating the top wall section 864b above a defined temperature.

The side wall section 864a and the top wall section 864b are preferably formed by a bell jar 864, wherein the bell jar 864. The bell jar 864 is preferably movable with respect to the base plate 862.

Fig. 12a shows a first multi-piece SiC growth substrate 857. Thus, it is possible to have at least or exactly two pieces 2224a of a first type defining the length of the SiC growth substrate 857. The SiC growth substrate 857 is preferably formed in a “U-shape”. Such a “U-shape” is preferably characterized by a first leg 2232 and a second leg 2234 and a connecting part 2236 for connecting the first leg 2232 and the second leg 2234. The first leg 2232 is preferably formed negative to the second leg 2234. However, it is also possible to have the first leg 2232 formed by main pieces of a first type and the second leg by main pieces of a second type. It is additionally or alternatively possible that the first leg 2232 comprises a first number of pieces 2224a and/or 2224b and that the second leg 2234 comprises a second number of pieces 2224a and/or 2224b. The same applies for the other multi piece SiC substrates 857 disclosed herein. Fig. 12b shows a further example of a further multi-piece SiC growth substrate 857. Thus, contrary to the SiC growth substrate 857 of Fig. 12a the present SiC growth substrate 857 comprises a first leg 2232 and a second leg 2234, wherein each leg 2232/2234 comprises more than two pieces 2224a of a first type and more than two pieces 2224b of a second type.

Fig. 12c shows a further example of a further multi-piece SiC growth substrate 857. According to this example the individual pieces 2224a can be arranged in angles different than 90° or 180°.

Fig. 12d shows schematically that two pieces 2224a of a first type preferably can be arranged in such a manner that a central axis 2226 of one piece and a central axis 2228 of the other piece are arranged in a distance to each other, in particular in a distance of ore than 8cm or more than 12cm or more than 15cm. The central axes 2226, 2228 are preferably arranged in parallel to each other.

Fig. 12e shows a further example of a multi-piece SiC growth substrate 857. The pieces 2224a of the first type can be coupled via pieces 2224b of a second type, wherein the diameter of the pieces 2224b of the second type is preferably so large that at least one section of the surface surrounding the central axis of the pieces 2224b of the second type surrounds the central axis in a distance of 0,5 x diameter. This embodiment is beneficial since depositing of SiC is prevented or limited to avoid forming of a SiC crust on the circumferential surface of the connecting piece 2224b.

Fig. 12f schematically shows an example of how two pieces 2224a can be coupled by a large diameter connecting piece 2224b.

Fig. 12g schematically shows an example of a long none-SiC-substrate 2223, e.g. graphite, wherein a surface temperature lowering element 2238 is coupled to the long-none-SiC- substrate 2223. The long none-SiC-substrate 2223 preferably has a length of more than 25cm and particular preferably of more than 50cm and highly preferably of 75cm and most preferably of more than 100cm or a length between 50cm and 200cm, in particular between 60cm and 150cm. The diameter of the surface temperature lowering element 2238 is preferably larger than 1.3 x diameter of long-none-SiC-substrate 2223 and preferably larger than 1.5 x diameter of long-none-SiC-substrate 2223 and highly preferably larger than 2 x diameter of long-none- SiC-substrate 2223 and most preferably larger than 2.5 x diameter of long-none-SiC-substrate 2223. The surface temperature lowering element 2238 is preferably made of graphite or preferably comprises graphite. The surface temperature lowering element 2238 can be a one- piece element or can be made of multiple pieces, in particular two or more than two pieces. The surface temperature lowering element 2238 can be attached to the long none-SiC-substrate 2223 by means of an adhesive connection and/or force closure and/or form closure.

Fig. 13a-d show that the SiC growth substrates 857 shown in fig. 12a, b, c and e do not have to be shaped in the form of an “II” since it is also possible to shape them in different forms. One further example if a preferred form is a “I” form. According to the “I” the electrical connections are arranged on opposing sides of the reaction space 966. Furthermore, the SiC growth substrates 857 can be formed in “N”, “M” or “W” shape, wherein preferably only two electrical connections are provided per SiC growth substrate, in particular at the end of the respective substrate (in analog manner to the “II” shape).

Fig. 13e shows a SiC growth substrate 857 which is a single piece 2222. The single piece SiC growth substrate 857 can be solid or hollow. Thus, the single piece SiC growth substrate 857 can be formed as a solid rod 2218 or tube. The single piece SiC growth substrate 857 can be made of SiC or graphite.

Fig. 14a schematically shows an example of a blade or band like 2214 SiC growth substrate 857. Said SiC growth substrate 857 can be a single piece or formed by multiple pieces. The SiC growth substrate 857 preferably comprises graphite respectively carbon fibers. Highly preferably the SiC growth substrate 857 is made of one or multiple carbon fiber composite elements 2242.

Fig. 14b schematically shows a cross-sectional view of the blade or band like 2214 SiC growth substrate 857 of Fig. 14a. It can be understood from fig. 14b that width W is multiple times larger compared to depth D. Depth D is preferably smaller than 0,5cm, in particular smaller than 0,2cm or is between 0,01cm and 0,15cm. Width W is preferably above 3cm and highly preferably above 10cm and most preferably above 15cm. Such a W/D ratio is highly beneficial since a significant amount of SiC can be deposited immediately after a start of a production run. Fig. 14c schematically shows an example of a tube like 2220 SiC growth substrate 857. Said SiC growth substrate 857 can be a single piece or formed by multiple pieces. The SiC growth substrate 857 preferably comprises graphite respectively carbon fibers. Highly preferably the SiC growth substrate 857 is made of one or multiple carbon fiber composite elements 2242. Fig. 14d schematically shows a cross-sectional view of the blade or band like 2220 SiC growth substrate 857 of Fig. 14c. It can be understood from fig. 14d that a diameter of the tube is preferably multiple times, in particular more than 2,5 times or preferably more than 3 times or highly preferably more than 4 times and most preferably more than 5 times, larger compared to the thickness of the tube wall.

Fig. 15a-c schematically show different examples of SiC growth substrates 857 according to the present invention. In each of said figures a region is defined in which crack-free material is formed. That region is formed between a first plane 2204 and a second plane 2206, wherein the first plane 2204 and the second plane 2206 are parallel to each other and in a distance 2208 to each other. The distance 2208 is preferably lager than 1cm and preferably larger than 2cm and highly preferably larger than 5cm and most preferably larger than 10cm or the distance is between 1 ,5cm and 50cm, in particular between 2cm and 25cm or between 2,2cm and 15cm.

Fig. 15a shows carbon fibers 2210, wherein said carbon fibers 2210 are preferably arranged in different directions and thereby form a carbon fiber composite material 2212.

Fig. 15d schematically shows an example of a cross-sectional view through rod shaped 2218 SiC growth substrate 857 of fig. 15c.

Thus, the present invention refers to a SiC growth substrate 857 for growing SiC in a CVD reactor 850. Said SiC growth substrate 857 preferably comprises at least a main body 2200, a first power connection 859a and a second power connection 859b, wherein the main body 2200 has a main body length ML, wherein the main body length ML extends between the first power connection 859a and the second power connection 859b. The first power connection 859a is preferably configured to conduct power into the main body 2200 for heating the main body 2200 and wherein the second power connection 859b is preferably configured to conduct electric power conducted via the first power connection 859a into the main body 2200 out of the main body 2200. The first power connection 859a and/or the second power connection 859b is/are preferably coupled to an alternating current source. The main body 2200 forms a physical structure, wherein the physical structure preferably forms a deposition surface 861 for deposition of SiC for growing a SiC crust 211 . The physical structure is preferably configured to resist forces generated during growth of the SiC crust 211 having a minimal thickness of at least 1cm. Alternatively the physical structure is preferably configured to prevent generating of forces during growth of the SiC crust 211 having a minimal thickness of at least 1cm. Both (resisting/preventing) preferably allows or causes preventing of cracking of the physical structure due to the generated forces at least in a defined volume section of the physical structure. The defined volume section 2202 is preferably formed between a first plane 2204 and a second plane 2206, wherein the first plane 2204 is highly preferably perpendicular to the main body length ML and wherein the second plane 2206 is perpendicular to the main body length ML or perpendicular to a main extension direction of a connecting part 2236. The distance 2208 between the first plane 2204 and the second plane 2206 is preferably at least 5% of the main body length ML.

Fig. 16a-16c schematically show examples of carbon fiber composite elements 2242 for forming a SiC growth substrate 857. The carbon fiber composite element 2242 are preferably very thin or comprise very thin sections, in particular less than 1cm thick or less than 0,5cm thick or less than 0,2cm or less than 0,1cm. The carbon fiber composite elements 2242 preferably have a shape, in particular a bend or sharp bend, that gives the carbon fiber composite elements 2242 a mechanical stability for allowing upright positioning.

Fig. 16d schematically shows an example according to which a first carbon fiber composite element 2242a, a second carbon fiber composite element 2242b and a third carbon fiber composite element 2242c are coupled to each other to form a SiC growth substrate 857. In the present example the carbon fiber composite elements 2242a/b and carbon fiber composite element 2242b/c form overlapping areas 2230 for coupling the respective carbon fiber composite elements 2242a/b or 2242b/c. In the present example coupling is carried out be means of coupling elements 2230, wherein said coupling elements 2230 can be e.g. screws or pins or studs. The coupling elements 2230 are preferably made of graphite. However, it is additionally or alternatively possible to couple the carbon fiber composite elements 2242a/b and/or carbon fiber composite elements 2242b/c by means of a force closure and/or form closure and/or adhesive closure. In the present example the carbon fiber composite elements 2242a/b and carbon fiber composite elements 2242b/c are having the same or similar shapes, however it is possible that some or all of the carbon fiber composite elements can have different shapes respectively a shape different from the shape of at least one further carbon fiber composite element.

Fig. 17a-c schematically show further examples of carbon fiber composite elements 2242. Said carbon fiber composite elements 2242 can be manufactured to allow form and/or force closure.

Fig. 17d schematically shows an example of a further SiC growth substrate 857 formed by multiple carbon fiber composite elements 2242. Fig. 18a schematically shows an example of a CVD reactor 850. Said CVD reactor 850 comprises a process chamber 856 a gas inlet unit 866, in particular a pipe, for feeding gas into the process chamber 856 and a gas outlet unit 216, in particular a pipe, for removing remaining gas from the process chamber 856. Inside the process chamber 856 a SiC growth substrate 2200 is provided, wherein said SiC growth substrate 2200 is coupled with a first end with a first electrode 206a and with a second end with a second electrode 206b. Electric energy is conducted form one electrode 206a to the other electrode 206b and therefore through the SiC growth substrate 2200 for heating the SiC growth substrate 2200. A CVD reactor similar to the CVD reactor 850 is described in detail by PCT/EP2021/085513, which is entirely incorporated by reference into the subject-matter of the present disclosure.

Fig. 18b shows an example of a SiC production reactor 850 according to the present invention. Said SiC production reactor 850 preferably comprises a process chamber 856, wherein the process chamber 856 is at least surrounded by a bottom wall section, in particular a base plate 862 or base plate wall section, a side wall section 864a and a top wall section 864b, a gas inlet unit 866 for feeding one feed-medium or multiple feed-mediums into a reaction space of the process chamber 856 for generating a source medium. The gas inlet unit 866 is preferably coupled with at least one feed-medium source 851, wherein preferably a Si and C feed-medium source 851 is configured to provide at least Si and C, in particular SiCI3(CH3), and wherein a carrier gas feed-medium source 853 provides a carrier gas, in particular H2, or wherein the gas inlet unit 866 is preferably coupled with at least two feed-medium sources 851, 852, wherein a Si feed medium source 851 is preferably configured to provide at least Si and wherein a C feed medium source 852 provides at least C, in particular natural gas, Methane, Ethane, Propane, Butane and/or Acetylene, and wherein a carrier gas medium source 853 is configured to provide a carrier gas, in particular H2. The reactor 850 preferably also comprises at least one SiC growth substrate surface 2205 is formed inside the process chamber 856 by a wall surface section 2270, and a heating unit 2314 for non-electrically generation of heat is provided, wherein the heating unit 2314 is configured for heating at least the SiC growth substrate surface 2205 to a temperature above 1300°C.

The heating unit 2314 comprises according to the present example at one or multiple combustion guide element/s 2282 for causing a flame 2280 for heating the wall member 864a. It is also possible that one or multiple flames 2280 can be caused to directly heat one or multiple further wall sections, in particular an opposing wall section and/or one or multiple neighboring wall section and/or a top wall section 864b and/or a bottom wall section 862. Fig. 19a shows that at least one flame 2280 heats up wall member 2271 form one side and SiC deposits on the other side - which can be understood as SiC growth face of said wall member 2271. The dotted lines schematically indicate that one or multiple further wall member/s can be heated with flames 2280. Burning of gas is a reliable and cheap method for heating the wall member 2271.

According to Fig. 19b cooling elements 2274 can be provided for cooling down the SiC growth face 2203 to a temperature below the lowest deposition temperature. Thus, growth of SiC can be limited to a defined surface section 2271 of the first SiC growth face 2203. Deposition of SiC is thus prevented in colder sections 2272.

Fig. 20 schematically shows an example of a reactor design, according to which heat radiation 2284 from one growth face radiates to an overlaying growth face. Fig. 20 additionally shows that a reactor 850 according to the present invention can comprise more than four SiC growth substrates 2200a-d and preferably six or more than six SiC growth substrates2200a-f.

Fig. 21a shows an example of a SiC growth substrate 2200 having at least one growth face 2205, wherein a heat guide or gas guide 2282, in particular pipe, for heating the at least one growth face 2205 to a temperature above 1300°C is provided. The gas guide 2282 preferably comprises at least one or multiple outlets 2283 for letting out the guided gas for burning said gas and thereby preferably causing at least one flame 2280.

Fig. 21b shows that multiple SiC growth substrates 2200a-d can be arranged inside a CVD reactor 850 according to the present invention. Each SiC growth substrate 2200a-d preferably forms at least one growth face section 2203, 2205, 2207 and 2209. Furthermore, preferably each SiC growth substrate 2200a-d surrounds a fluid guide passage for heating the respective SiC growth substrate 2200a-d. According to the described kind of SiC growth substrates 2200a- d a fast SiC deposition takes place since the available surface size is already large at the beginning of a production run (compared to resistive heating rods).

Fig. 21c shows one SiC growth substrate 2200a heated from the inside, in particular by burning a fluid provided via fluid guide 2282.

Fig. 21 d schematically shows how multiple of said SiC growth substrates 2200a-b are heated during a production run. Reference number 926 refers to a control unit for controlling one or multiple parameters of the production process, e.g., heating and/or gas flow into the process chamber and/or cooling, etc. Fig. 22 shows a further preferred example of a SiC production reactor 850 according to the present invention. Said production reactor preferably comprises at least a process chamber 856, a gas inlet unit 866 for feeding one feed-medium or multiple feed-mediums into a reaction space of the process chamber 856 for generating a source medium. The reactor 850 preferably also comprises at least one SiC growth substrate surface 2205 which is formed inside the process chamber 856 by a wall surface section 2270, wherein the wall surface section 2270 is preferably a wall section of a SiC growth substrate 2200a. Additionally the reactor preferably comprises a heating unit 2314 for non-electrically generation of heat, wherein the heating unit 2314 is configured for heating at least the SiC growth substrate surface 2205 to a temperature above 1300°C, wherein the heating unit 2314 preferably forms a fluid guide means 2288 for guiding fluid heated to a temperature above 1300°C for heating the wall member 2271 , in particular the SiC growth substrate, for heating the wall surface section 2270, in particular of the SiC growth substrate respectively the growth face of the deposited SiC. The fluid is preferably generated respectively heated by burning an energy liquid, in particular natural gas or H2 or biogas or methane etc.

The process chamber 856 is preferably at least surrounded by a bottom wall section, in particular a base plate 862 or base plate wall section, a side wall section 864a and a top wall section 864b. The gas inlet unit 866 is preferably coupled with at least one feed-medium source 851 , wherein preferably a Si and C feed-medium source 851 is preferably configured to provide at least Si and C, in particular SiCI3(CH3), and wherein a carrier gas feed-medium source 853 provides a carrier gas, in particular H2. Alternatively, it is possible that the gas inlet unit 866 is preferably coupled with at least two feed-medium sources 851, 852, wherein a Si feed medium source 851 is preferably configured to provide at least Si and wherein a C feed medium source 852 preferably provides at least C, in particular natural gas, Methane, Ethane, Propane, Butane and/or Acetylene, and wherein a carrier gas medium source 853 is preferably configured to provide a carrier gas, in particular H2,

Fig. 23a and b schematically disclose alternative heating units 2314. According to the heating unit 2314 of fig. 23a and 23b the fluid, in particular natural gas, methane, biogas or H2, is burned to heat a further fluid which is arranged inside a fluid guide 2288, in particular a pipe. Reference number 2298 indicates an outlet for removing the burned fluid from the combustion compartment 2286. The small arrow 2292 indicates a low fluid temperature inside the fluid guide 2288 and the larger arrows 2294 indicate an increased fluid temperature. Fig. 23b shows a surface increased (compared to fig. 23a) heat exchanger 2296.

Fig. 23c schematically shows that the heated fluid, in particular a gas, travels through the SiC growth substrate 2200a for increasing the temperature of the growth face section above 1300°C.

Fig. 24a schematically shows a hollow housing 2320, wherein the hollow housing 2320 is preferably made of graphite or CFC material, in particular thin sheets of CFC material. The average wall thickness of the hollow housing 2320 is preferably smaller than 5cm and particular preferably smaller than 3cm and highly preferably smaller than 1cm and most preferably smaller than 0,5cm.

Fig. 24b schematically shows the hollow housing 2320 of fig. 24a positioned on a carrying and/or holding unit 2260.

According to fig. 24c a SiC growth substrate 2200a, in particular a thin and/or flexible SiC growth substrate 2200a, is arranged on at least sections of the outer surface of the hollow housing 2320. The SiC growth substrate 2200a is preferably configured as thin sheets of CFC material, wherein “thin” means a thickness of less than 3cm and preferably of less than 1cm and highly preferably of less than 0,5cm and most preferably of less than 0,25cm (per sheet).

Fig. 24d shows a side view of the hollow housing 2320 and schematically an example of a heating unit 2314. The heating unit 2314 can be a resistive heating unit 2314, wherein electric energy is conducted via electrodes 2232 through a heat emitting element, in particular at least one electric resistor, or a heating unit analog to any of figures 21a-d, 22 or 23a-c.

Fig. 24e schematically shows a situation during or after a production run, wherein a crust 2252 of SiC is deposited onto the SiC growth substrate 2200a, in particular the hollow housing 2320 or the foil 2250.

Fig. 25a schematically shows a further example of a hollow housing 2320.

Fig. 25b schematically shows a SiC growth substrate, in particular foil 2250, holding member 2322 arrange on or above the hollow housing 2320. A SiC growth substrate 2200a, in particular a foil and/or one or multiple sheets of CFC material, is arranged on the SiC growth substrate holding member 2322 and overlaps preferably more than 50% of the outer surface of the hollow housing 2320 and preferably more than 75% of the outer surface of the hollow housing 2320 and most preferably more than 85% of the outer surface of the hollow housing 2320. The SiC growth substrate, in particular foil, holding member 2322 can be separated from the hollow housing 2320 without damaging or destroying the hollow housing 2320. Thus, after a production run the grown SiC can be easily removed by means of the SiC growth substrate, in particular foil, holding member 2322.

Fig. 25c schematically shows a side view of the arrangement of fig. 25b.

Fig. 26a schematically shows an example of a further SiC production reactor 850, in particular for the production of 3C-SiC material, according to the present invention. The reactor 850 preferably comprises one or multiple, in particular more than 2 or more than 4 or more than 10 or up to 20 or up to 50 or up to 100, hollow housings 2320 (e.g., as described with respect to fig. 10a-e and/or fig. 25a-c), wherein at least some of the hollow housings 2320 and preferably 50% or more than 50% of the hollow housings 2320 cover heating units 2314.

A source gas or source gas mixture can be feed into the reaction space via one or multiple gas inlet units 866, wherein preferably at least one gas inlet unit 866 is preferably arranged between two hollow housings 2320. The gas, which is feed into the reaction space, is preferably further heated. It is possible to remove heat from the heated gas by means of a heat exchanger 2299, in particular positioned below the hollow housings 2320.

Fig. 26b further shows another example of a SiC production reactor 850 according to the present invention, wherein a cooling guide 872 is provided, in particular in or on a wall which forms the process chamber 856, for actively removing heat from the wall. Thus, due to the cooling the wall, which forms the process chamber 856, can be made of metal, in particular steel. Reference number 2302 indicates a cooling fluid inlet for feeding cooling fluid into the cooling fluid guide 872 and reference number 2304 indicates a cooling fluid outlet for removing the cooling fluid from the cooling fluid guide 872.

Fig. 26c schematically shows a further example of a SiC reactor 850 of the present invention. The SiC reactor 850 comprises multiple SiC growth substrates 2200a, 2200b and 2200c. The growth faces 2203 and 2209 are arranged opposite to each other. The same applies to growth faces 2207 and 2213. This embodiment is beneficial since heat radiation radiated from one of said growth faces 2203, 2209, 2207 and 2213 heats the overlapping growth face.

The fourth growth face section 2209 preferably overlays in a first direction D1 at least 50% of the first growth face section 2203, wherein the size of the fourth growth face section 2209 is at least 80%, in particular more than 90% or more 95%, of the size of the first growth face section 2209.

The sixth growth face section 2213 preferably overlays in a fifth direction D5 at least 50% of the third growth face section 2207, wherein the size of the sixth growth face section 2213 is at least 80%, in particular more than 90% or more 95%, of the size of the third growth face section 2207.

Fig. 26d schematically shows an example of a SiC growth substrate 2200a having a first growth face section 2203 and a second growth face section 2205. The direction D1 indicates a normal of the first growth face section 2203. The direction D2 indicates a normal of the second growth face section 2205. OD1 indicates a direction opposite to D1. According to fig. 23d D2 and OD1 are parallel to each other. Thus, the second direction D2 is aligned less than 20°, in particular less than 10° or less than 5°, to the opposite direction OD1 of the first direction D1.

Fig. 26e schematically shows a further example of a SiC growth substrate 2200a having a first growth face section 2203 and a second growth face section 2205. The direction D1 indicates a normal of the first growth face section 2203. The direction D2 indicates a normal of the second growth face section 2205. OD1 indicates a direction opposite to D1. According to fig. 23e D2 and OD1 are inclined to each other. According to the present invention the angle between D2 and OD1 is preferably less than 20°, in particular less than 10° or less than 5°.

Fig. 27 schematically shows an example of a further SiC reactor 850 of the present invention. The SiC reactor 850 comprises a plurality of SiC growth substrates 2200a-x. Said SiC growth substrates 2200a-x are preferably formed in a plate-shaped manner and/or form hollow housings 2320. The SiC growth substrates 2200a-x can be electrically heated, in particular by conducting current through the SiC growth substrates 2200a-x. In case at least some or all of the SiC growth substrates 2200a-x are hollow housings 2320 the hollow housings 2320 preferably cover heating units 2314 for heating the SiC growth substrates 2200a-x.

The first SiC growth substrate 2200a of said multiple SiC growth substrates 2200a-x comprises at least a first growth face section 2203 facing into a first directing D1 and a second growth face section 2205 facing into a second direction D2, wherein the second direction D2 is aligned less than 20°, in particular less than 10° or less than 5°, to the opposite direction OD1 of the first direction D1. The second SiC growth substrate 2200b of said multiple SiC growth substrates 2200a-x comprises at least a third growth face section 2207 facing into a third direction D3, wherein the third direction D3 is aligned less than 20°, in particular less than 10° or less than 5°, to the first direction D1 and a fourth growth face section 2209 facing into a fourth direction D4.

The third SiC growth substrate 2200c of said multiple SiC growth substrates 2200a-x comprises at least a fifth growth face section 2211 facing into the fifth direction D5, wherein the fifth direction D5 is aligned less than 20°, in particular less than 10° or less than 5°, to the third direction D3 and a sixth growth face section 2213 facing into a sixth direction D6. The same applies for all remaining SiC growth substrates 2200d-x, which are not described in the following.

The features described with respect to fig. 24a-26e can be applied in analogous manner and vice versa.

Fig. 28a shows the reactor shown in fig. 27 and indicates that the the fourth growth face section 2209 overlays in the first direction D1 at least 50% of the first growth face section 2203, wherein the size of the fourth growth face section 2209 is at least 80%, in particular more than 90% or more 95%, of the size of the first growth face section 2203 and wherein the sixth growth face section 2213 overlays in the fifth direction D5 at least 50% of the third growth face section 2207, wherein the size of the sixth growth face section 2213 is at least 80%, in particular more than 90% or more 95%, of the size of the third growth face section 2207, etc. This embodiment is beneficial since radiated heat heats an opposing growth face and therefore significantly reduces radiation losses.

Fig. 28b schematically shows a SiC growth substrate 2200a, which can be provided as hollow housing, respectively a hollow housing 2320 for folding a SiC growth substrate 2200a, in particular a foil 2250. In particular in case of a circular reactor a SiC growth substrate 2200a respectively a hollow housing 2314 having a triangular or cone shape can be beneficial to increase the overlap between overlapping growth face sections.

Fig. 28c schematically shows an enhanced overlap of overlapping growth face sections 2203 and 2209 and/or 2207 and 2213.

Fig. 29 schematically shows a section of the reactor of fig. 27 and 28 in a perspective view.

Thus, the present invention refers to a SiC production reactor 850, at least comprising a process chamber 856, wherein the process chamber 856 is at least surrounded by a bottom wall section 862, in particular a base plate 862 wall section, a side wall section 864a and a top wall section 864b, a gas inlet unit 866 for feeding one feed-medium or multiple feed-mediums into a reaction space of the process chamber 856 for generating a source medium, wherein the gas inlet unit 866 is preferably coupled with at least one feed-medium source 851, wherein preferably a Si and C feed-medium source 851 is configured to provide at least Si and C, in particular SiCI3(CH3), and wherein a carrier gas feed-medium source 853 is configured to provide a carrier gas, in particular H2, or wherein the gas inlet unit 866 is preferably coupled with at least two feed-medium sources 851, 852, wherein a Si feed medium source 851 is preferably configured to provide at least Si and wherein a C feed medium source 852 is configured to provide at least C, in particular natural gas, Methane, Ethane, Propane, Butane and/or Acetylene, and wherein a carrier gas medium source 853 provides a carrier gas, in particular H2, multiple SiC growth substrates 2200a-x, in particular more than 3 or 4 or 6 or 8 or 16 or 32 or 64 or up to 128 or up to 256, are arranged inside the process chamber 856 for depositing SiC, wherein a first SiC growth substrate 2200a of said multiple SiC growth substrates 2200a-x comprises at least a first growth face section 2203 facing into a first directing D1 and a second growth face section 2205 facing into a second direction D2, wherein the second direction D2 is aligned less than 20°, in particular less than 10° or less than 5°, to the opposite direction OD1 of the first direction D1, wherein a second SiC growth substrate 2200b of said multiple SiC growth substrates 2200a-x comprises at least a third growth face section 2207 facing into a third direction D3, wherein the third direction D3 is aligned less than 20°, in particular less than 10° or less than 5°, to the first direction D1 and a fourth growth face section 2209 facing into a fourth direction D4, wherein a third SiC growth substrate 2200c of said multiple SiC growth substrates 2200a-x comprises at least a fifth growth face section 2211 facing into the fifth direction D5, wherein the fifth direction D5 is aligned less than 20°, in particular less than 10° or less than 5°, to the third direction D3 and a sixth growth face section 2213 facing into a sixth direction D6, wherein the fourth growth face section 2209 overlays in the first direction D1 at least 50% of the first growth face section 2203, wherein the size of the fourth growth face section 2209 is at least 80%, in particular more than 90% or more 95%, of the size of the first growth face section 2209, wherein the sixth growth face section 2213 overlays in the fifth direction D5 at least 50% of the third growth face section 2207, wherein the size of the sixth growth face section 2213 is at least 80%, in particular more than 90% or more 95%, of the size of the third growth face section 2207.

Thus, the present invention refers to a SiC production reactor 850, wherein the SiC production reactor 850 at least comprises: A process chamber 856, wherein the process chamber 856 is at least surrounded by a bottom wall section, in particular a base plate 862 or base plate wall section, a side wall section 864a and a top wall section 864b, a gas inlet unit 866 for feeding one feed-medium or multiple feed-mediums into a reaction space of the process chamber 856 for generating a source medium, wherein the gas inlet unit 866 is preferably coupled with at least one feed-medium source 851, wherein preferably a Si and C feed-medium source 851 is configured to provide at least Si and C, in particular SiCI3(CH3), and wherein a carrier gas feedmedium source 853 provides a carrier gas, in particular H2, or wherein the gas inlet unit 866 is preferably coupled with at least two feed-medium sources 851, 852, wherein a Si feed medium source 851 is preferably configured to provide at least Si and wherein a C feed medium source 852 provides at least C, in particular natural gas, Methane, Ethane, Propane, Butane and/or Acetylene, and wherein a carrier gas medium source 853 is configured to provide a carrier gas, in particular H2, at least one SiC growth substrate surface 2205 is formed inside the process chamber 856 by a wall surface section 2270, a heating unit 2314 for non-electrically generation of heat is provided, wherein the heating unit 2314 is configured for heating at least the SiC growth substrate surface 2205 to a temperature above 1300°C.

List of reference numbers

202 Upper housing respectively carrier gas feed-medium

203 Cross member source

206a first electrode 854 mixing device

206b second electrode 855 evaporator device

208 Chuck 856 process chamber

209 Temperature measurement path 857 SiC growth substrate

211 SiC crust 858 temperature measuring device or

213 Sight glass temperature control unit

216 gas outlet unit 859 Energy source, especially power

602 separating unit supply

859a first power connection

612 further separating unit 859b second power connection

624 first fluid 860 Pressure maintaining device or

626 second fluid pressure control unit

861 outer surface of SiC growth

850 manufacturing device or CVD unit or substrate or SiC growth surface CVD reactor respectively CVD SiC 862 base plate production reactor, in particular SiC 864 bell jar PVT source material production 864a side wall section reactor 864b top wall section

851 first feeding device respectively first 865 metal surface feed-medium source 866 gas inlet unit

852 second feeding device respectively 867 reflective coating second feed-medium source 868 cooling element

853 third feeding device respectively 870 active cooling element third feed-medium source 872 cooling fluid guide

873 fluid forwarding unit 892 cooling fluid temperature sensor 2223 long-non-SiC-substrate

926 control device or control unit 2224 multi piece

2224a first piece I main piece

966 reaction space 2224b second piece I connecting piece

1160 Feed gas mixture 2226 first central axis

2040 Lower housing 2228 second central axis

2120 Vent gas 2230 overlap area

2140 Feed gas inlet 2232 first leg

2200 main body 2234 second leg

2200a-xSiC growth substrates 2236 connecting part

2200a first SiC growth substrate 2238 surface temperature lowering

2200b second SiC growth substrate element

2200c third SiC growth substrate 2240 lateral surface I circumferential

2202 defined volume section surface

2242 carbon fiber composite element

2203 first growth face section 2242a first carbon fiber composite element

2242b second carbon fiber composite

2204 first plane element

2205 second growth face section 2242c third carbon fiber composite element

2244 coupling element

2206 second plane 2250 foil - thin and/or flexible substrate

2207 third growth face section 2252 SiC grown on SiC growth substrate

2260 carrying and/or holding unit

2208 distance 2270 wall surface section of the wall

2209 fourth growth face section member

2270a side wall section

2210 carbon fibers 2270b top wall section

2211 fifth growth face section 2271 wall member

2272 cooler section of the wall member

2212 carbon fiber composite material 2274 cooling element

2213 sixth growth face section 2280 flame

2282 energy source I combustion fluid

2214 band like shape I blade like shape 2283 combustion gas outlet

2216 graphite element 2284 heat radiation

2218 solid SiC rod 2286 combustion compartment

2220 tubular shape 2288 hot gas channel I combustion gas

2222 single piece guide / fluid guide means 2290 deflector member 2420 second part

2292 cold fluid 2421 STC and TCS dividing device

2294 hot fluid 2422 STC storage

2296 heat exchanger 2424 TCS storage

2298 exhaust pipe 2425 metals removing device

2299 heat exchanger 2426 waste storage

2300 overlayed surface section 2428 paused/reduced vent gas mixture

2302 cooling fluid inlet feeding

2304 cooling fluid outlet 2430 TCS storage to bed reactor path

2306 angle between D1 and D3 2432 SI supply unit

2308 angle between D3 and D5 2434 HCI supply unit

2310 angle between D2 and D4 2436 second fluid treatment unit I

2312 angle between D4 and D6 absorber

2314 heating unit 2438 washer

2316 electrodes 2440 combustion unit I flare

2318 heat emitting element 2450 vent gas storage

2320 hollow housing 2460 exchange device

2322 foil holding member, in particular foil 2462 dotted arrow I input path holding rod

2394 Chlorosilanes D1 first direction

2398 Si OD1 opposite to first direction

2400 vent gas mixture D2 second direction

2401 further fraction of vent gas mixture D3 third direction

2400 vent gas conduit D4 fourth direction

2412 first storage and/or conducting D5 fifth direction element D6 sixth direction

2414 second storage and/or conducting element D Depth

2416 bed reactor ML Main body length

2417 gas inlet W Width

2418 first part

Claims

1. Method for the production of SiC

At least comprising the steps:

Providing a vent gas mixture (2400), wherein the vent gas mixture (2400) is preferably generated during SiC production and highly preferably generated during CVD SiC production, wherein at least a first fraction of the vent gas mixture is HCI, wherein a second fraction of the vent gas mixture consists of vent gas Chlorosilanes, in particular STC and/or TCS, wherein a third fraction (2401) of the vent gas mixture (2400) comprises or consists of H2 (2402) and wherein a fourth fraction of the vent gas mixture (2400) comprises or consists of at least one C-bearing-molecule, in particular methane, (2404),

Providing solid Si inside a reactor chamber, wherein the solid Si comprises metal impurities of more than 1000ppmw,

Forwarding at least the second fraction of the vent gas mixture (2400) and the third fraction of the vent gas mixture (2400) and the fourth fraction of the vent gas mixture and most preferably all fractions of the vent gas mixture (2400) into the reactor chamber,

Forwarding at least the generated Chlorosilanes (2394) into a process chamber (856a) of the CVD SiC production reactor (850a), and

Forwarding at least one C-bearing molecule into the CVD SiC production reactor (850a),

Producing SiC inside the process chamber (856a) of the CVD SiC production reactor (850a) by reacting the generated Chlorosilanes and C from the at least one C-bearing molecule on at least one deposition surface or

Forwarding at least the generated Chlorosilanes (2394) into a process chamber (856b) of a further CVD SiC production reactor (850b), and

Forwarding at least one C-bearing molecule into the further CVD SiC production reactor (850b), Producing SiC inside the process chamber (856) of the further CVD SiC production reactor (850b) by reacting the generated Chlorosilanes and C from the at least one C- bearing molecule on at least one deposition surface.

2. Method for the production of SiC

At least comprising the steps:

Forwarding at least the generated Chlorosilanes (2394) into a process chamber (856b) of a further CVD SiC production reactor (850b), and Forwarding at least one C-bearing molecule into the further CVD SiC production reactor (850b),

Producing SiC inside the process chamber (856) of the further CVD SiC production reactor (850b) by reacting the generated Chlorosilanes and C from the at least one C- bearing molecule on at least one deposition surface.

3. Method according to claim 1 or 2, characterized by a step of reducing the amount of metal impurities within the generated Chlorosilanes below 20ppmw and preferably below 10ppmw and highly preferably below 5ppmw and most preferably below 1 ppmw.

4. Method according to claim 3, characterized in that the step of reducing the amount of metal impurities within the generated Chlorosilanes below 20ppmw and preferably below 10ppmw and highly preferably below 5ppmw and most preferably below 1 ppmw is carried out before the generated Chlorosilanes (2394) are forwarded into the process chamber (856a) of the CVD SiC production reactor (850a) or into the process chamber (856b) of the further CVD SiC production reactor (850b).

5. Method according to claim 4, characterized in that the step of reducing the amount of metal impurities within the generated Chlorosilanes below 20ppmw and preferably below 10ppmw and highly preferably below 5ppmw and most preferably below 1 ppmw is splitted into at least a first removal step and into a second removal step, wherein a first amount of metal impurities is removed in the first removal step and wherein a second amount of metal impurities is removed in a second removal step.

6. Method according to claim 4 or 5 characterized by the step of separating the generated Chlorosilanes (2394) and the third fraction (2401) of the vent gas mixture (2400) and the fourth fraction of the vent gas mixture (2400) into a first fluid (624) and into a second fluid (626).

7. Method according to claim 6, characterized in that the step of reducing the amount of metal impurities within the generated Chlorosilanes below 20ppmw and preferably below 10ppmw and highly preferably below 5ppmw and most preferably below 1ppmw and the step of separating the generated Chlorosilanes (2394) and the third fraction (2401) of the vent gas mixture (2400) and the fourth fraction of the vent gas mixture (2400) into a first fluid (624) and into a second fluid (626) are carried out by a separating unit.

8. Method according to claim 5, characterized in that the first removal step and the step of separating the generated Chlorosilanes (2394) and the third fraction (2401) of the vent gas mixture (2400) and the fourth fraction of the vent gas mixture (2400) into a first fluid (624) and into a second fluid (626) are carried out by a separating unit.

9. Method according to claim 8, characterized in that the second removal step is carried out by another device, in particular a further separating unit, in particular a Chlorosilane distillation column.

10. Method according to claim 5, characterized in that the step of reducing the amount of metal impurities within the generated Chlorosilanes below 20ppmw and preferably below 10ppmw and highly preferably below 5ppmw is carried out after the step of separating the generated Chlorosilanes (2394) and the third fraction (2401) of the vent gas mixture (2400) and the fourth fraction of the vent gas mixture (2400) into the first fluid (624) and into the second fluid (626).

11. Method according to any of the preceding claims characterized in that the vent gas mixture (2400) is feed from the CVD SiC production reactor (850) to the reactor chamber, wherein the reactor chamber is part of a bed reactor (2416), and/or from at least one further CVD SiC production reactor (850) to the reactor chamber, wherein the reactor chamber is part of the bed reactor (2416), wherein the step of generating Chlorosilanes (2394) by reacting the first fraction of the vent gas mixture and Si is carried out inside the bed reactor (2416), and/or the step of generating chlorosilanes by reacting the second fraction of the vent gas mixture, in particular STC, and the third fraction (2401) of the vent gas mixture (2400) and the solid Si is carried out inside the bed reactor (2416), wherein the bed reactor is preferably a fixed bed reactor or a fluidized bed reactor.

12. Method according to claim 11 , characterized in that the vent gas mixture (2400) is removed from the CVD SiC production reactor (850) or from the at least one further CVD SiC production reactor (850) in a heated configuration, wherein the vent gas mixture (2400) has a condensation temperature, wherein the vent gas mixture (2400) is kept above the condensation temperature.

13. Method according to any of claims 11 to 12, characterized in that solid Si (2398) is feed during the step of generating Chlorosilanes (2394) by reacting HCI and Si into the bed reactor (2416).

14. Method according to any of claims 6 to 13, characterized in that the at least one C-bearing molecule is a fraction of the second fluid (626) or the second fluid (626) consists of the at least one C-bearing molecule, wherein the step of forwarding at least one C-bearing molecule into the process chamber (856) comprises forwarding the second fluid (626) into the process chamber (856).

15. Method according to claim 14, characterized by a step of removing HCI from the second fluid (626) prior to the step of forwarding at least one C-bearing molecule into the process chamber (856).

16. Method according to any of claims 6 to 15, characterized by the step of forwarding the first fluid (624) from the separating unit (602) to a further separating unit (612) for separating the first fluid (624) into at least a first part and a second part (2418, 2420) prior to the step of forwarding the Chlorosilanes (2394) into the process chamber (856).

17. Method according to claim 16, characterized in that the further separating unit carries out the step of reducing the amount of metal impurities within the generated Chlorosilanes below 20ppmw and preferably below 10ppmw and highly preferably below 5ppmw, wherein the first part of said two parts comprises the Chlorosilanes (2394) and wherein the second part of said two parts comprises metal impurities removed during the step of reducing the amount of metal impurities within the generated Chlorosilanes below 20ppmw and preferably below 10ppmw and highly preferably below 5ppmw.

18. Method according to claim 16, characterized in that the first part (2418) of said two parts (2418, 2420) is or comprises TCS (Trichlorosilane) and wherein the second part (2420) of said two parts (2418, 2420) is or comprises STC (Silicon tetrachloride).

19. Method according to claim 18, characterized in that the step of forwarding the Chlorosilanes (2394) into the process chamber (856) comprises forwarding the first part (2418) of said two parts (2418, 2420) and/or forwarding the second part (2420) of said two parts (2418, 2420) into the process chamber (856) or wherein the step of forwarding the Chlorosilanes (2394) into the process chamber (856) consists of forwarding the first part (2418) of said two parts (2418, 2420) and/or forwarding the second part (2420) of said two parts (2418, 2420) into the process chamber (856).

20. Method according to claim 16 to 19, characterized in that the first storage and/or conducting element (624) connects the separating unit (602) with the further separating unit (612), wherein the further separating unit (612) is coupled with a STC storage (2422) and a TCS storage (2424), wherein the STC storage (2422) and/or the TCS storage (2424) forms a section of a Chlorosilanes mass flux path for conducting STC and/or TCS into the process chamber (856).

21 . Method according to any of claims 16 to 20, characterized in that the further separating unit (612) is a distillation column.

22. Method according to claim 21, characterized in that

STC is feed from the distillation column (612) to the STC storage (2422) and wherein TCS is feed from the distillation (612) column to the TCS storage (2422).

23. Method according to any of claims 21 or 22, characterized in that

STC is feed from the STC storage (2422) to the CVD SiC production reactor (850), without feeding TCS from the TCS storage (2424) to the bed reactor (2416).

24. Method according to any of claims 16 to 23, characterized in that the distillation column (612) separates one or multiple metallic components, in particular B, Al, Fe and/or P, from the first fluid (624), in particular prior to the separation of STC and TCS, wherein separated metallic component/s is/are preferably feed to a waste storage (2426).

25. Method according to any of claims 1 to 24, characterized in that

TCS is feed from the TCS storage (2424) to the bed reactor (2416) for converting at least a fraction of TCS into STC.

26. Method according to any of claims 1 to 25, characterized by

Generating Chlorosilanes (2394) inside the reactor chamber by reacting the first fraction of the vent gas mixture and the solid Si.

27. Method according to any of claims 1 to 26, characterized in that the CVD SiC production reactor (850) and preferably also the further CVD SiC production reactor, at least comprises the process chamber (856), wherein the process chamber (856) is at least surrounded by a bottom wall section (862), in particular a base plate (862) wall section, a side wall section (864a) and a top wall section (864b), a gas inlet unit (866) for feeding one feed-medium or multiple feed-mediums into a reaction space of the process chamber (856) for generating a source medium, wherein the gas inlet unit (866) is coupled with at least two feed-medium sources (851, 852), wherein a Si feed medium source (851) is at least coupled with a Chlorosilanes mass flux path for feeding the Chlorosilanes into the process chamber, wherein the Chlorosilanes preferably comprise STC or TCS or consist of STC or TCS separated from the first fluid, and wherein a C feed medium source (852) is configured to provide at least C-bearing molecule, in particular natural gas, Methane, Ethane, Propane, Butane and/or Acetylene, and wherein a carrier gas medium source (853) provides a carrier gas, in particular H2, multiple SiC growth substrates (2200a-x), in particular more than 3 or 4 or 6 or 8 or 16 or 32 or 64 or up to 128 or up to 256, are arranged inside the process chamber (856) for depositing SiC, wherein a first SiC growth substrate (2200a) of said multiple SiC growth substrates (2200a-x) comprises at least a first growth face section (2203) facing into a first directing (D1) and a second growth face section (2205) facing into a second direction (D2), wherein the second direction (D2) is aligned less than 20°, in particular less than 10° or less than 5°, to the opposite direction (OD1) of the first direction (D1), wherein a second SiC growth substrate (2200b) of said multiple SiC growth substrates (2200a-x) comprises at least a third growth face section (2207) facing into a third direction (D3), wherein the third direction (D3) is aligned less than 20°, in particular less than 10° or less than 5°, to the first direction (D1) and a fourth growth face section (2209) facing into a fourth direction (D4), wherein a third SiC growth substrate (2200c) of said multiple SiC growth substrates (2200a- x) comprises at least a fifth growth face section (2211) facing into the fifth direction (D5), wherein the fifth direction (D5) is aligned less than 20°, in particular less than 10° or less than 5°, to the third direction (D3) and a sixth growth face section (2213) facing into a sixth direction (D6), wherein the fourth growth face section (2209) overlays in the first direction (D1) at least 50% of the first growth face section (2203), wherein the size of the fourth growth face section (2209) is at least 80%, in particular more than 90% or more 95%, of the size of the first growth face section (2209), wherein the sixth growth face section (2213) overlays in the fifth direction (D5) at least 50% of the third growth face section (2207), wherein the size of the sixth growth face section (2213) is at least 80%, in particular more than 90% or more 95%, of the size of the third growth face section (2207).

28. Method according to claim 27, characterized in that at least the first SiC growth substrate (2200a) covers from at least two sides a first heating unit (2314), wherein the first heating unit (2314) and the first SiC growth substrate (2200a) are configured to be non-destructively separable from each other.

29. Method according to claim 28, characterized in that the first SiC growth substrate (2200a) is formed by a hollow housing (2320), wherein the heating unit (2314) is positioned inside the hollow housing (2320).

30. Method according to claim 29, characterized in that the first SiC growth substrate (2200a) is formed by a foil (2250) or holds a SiC growth foil (2250).

31. Method according to claim 30, characterized in that the foil (2250) is arranged around at least two surface sections (2203, 2205) of a hollow housing (2320), wherein the heating unit (2314) is positioned inside the hollow housing (2320).

32. Method according to any of claims 1 to 26, characterized in that the CVD SiC production reactor (850) and preferably also the further CVD SiC production reactor, at least comprises the process chamber (856), wherein the process chamber (856) is at least surrounded by a bottom wall section, in particular a base plate (862) or base plate wall section, a side wall section (864a) and a top wall section (864b), a gas inlet unit (866) for feeding one feed-medium or multiple feed-mediums into a reaction space of the process chamber (856) for generating a source medium, wherein the gas inlet unit (866) is coupled with at least two feed-medium sources

(851, 852), wherein a Si feed medium source (851) is at least coupled with a Chlorosilanes mass flux path for feeding the Chlorosilanes into the process chamber, wherein the Chlorosilanes preferably comprise STC or TCS or consist of STC or TCS separated from the first fluid, and wherein a C feed medium source (852) is configured to provide at least a C-bearing molecule, in particular natural gas, Methane, Ethane, Propane, Butane and/or Acetylene, and wherein a carrier gas medium source (853) provides a carrier gas, in particular H2, at least one SiC growth substrate surface (2205) is formed inside the process chamber (856) by a wall surface section (2270), a heating unit (2314) for non-electrically generation of heat is provided, wherein the heating unit (2314) is configured for heating at least the SiC growth substrate surface (2205) to a temperature above 1300°C.

33. Method according to claim 32, characterized in that the heating unit (2314) is at least sectionally surrounded by a wall member forming the wall surface section.

34. Method according to claim 33, characterized in that the wall surface section (2270) is part of the side wall section (2270a) and/or top wall section (2270b) or part of a wall member (2271) surrounded by the side wall section (2270a) and top wall section (2270b).

35. Method according to claim 32 or 33 or 34, characterized in that the heating unit (2314) forms a fluid guide means (2288) for guiding fluid heated to a temperature above 1300°C for heating the wall member (2271) for heating the wall surface section (2270).

36. Method according to of claim 33 or 34 or 35, characterized in that the heating unit (2270) forms a fluid guide means (2288) for guiding a gas to at least one defined combustion space (2283) for burning the guided gas and thereby heating the wall member (2271) for heating the wall surface section (2270).

37. Method according to any of claims 1 to 26, characterized in that the CVD SiC production reactor (850) and preferably also the further CVD SiC production reactor, at least comprises the process chamber (856), wherein the process chamber (856) is at least surrounded by a base plate (862), a side wall section (864a) and a top wall section (864b), a gas inlet unit (866) for feeding one feed-medium or multiple feed-mediums into a reaction space of the process chamber (856) for generating a source medium, wherein the gas inlet unit (866) is coupled with at least two feed-medium sources (851, 852), wherein a Si feed medium source (851) is at least coupled with a Chlorosilanes mass flux path for feeding the Chlorosilanes into the process chamber, wherein the Chlorosilanes preferably comprise STC or TCS or consist of STC or TCS separated from the first fluid, and wherein a C feed medium source (852) is configured to provide at least a C-bearing molecule, in particular natural gas, Methane, Ethane, Propane, Butane and/or Acetylene, and wherein a carrier gas medium source (853) provides a carrier gas, in particular H2, one or multiple SiC growth substrate (857), in particular more than 3 or 4 or 6 or 8 or 16 or 32 or 64 or up to 128 or up to 256, are arranged inside the process chamber (856) for depositing SiC, wherein each SiC growth substrate (857) comprises: a main body (2200) for coupling with a first power connection (859a) and a second power connection (859b), wherein the first power connection (859a) is configured to conduct power into the main body (2200) for heating the main body (2200) and wherein the second power connection (859b) is configured to conduct electric power conducted via the first power connection (859a) into the main body (2200) out of the main body (2200), wherein the main body (2200) has a main body length (ML), wherein the main body (2200) forms a deposition surface (861) for deposition of SiC for growing a SiC crust (211), wherein the main body (2200) comprises carbon fibers (2210), wherein the main body (2200) is formed by a carbon fiber composite material (2212), wherein the main body (2200) formed by the carbon fiber composite material (2212) has a tensile strength above 50 MPa and/or a flexural strength above 50 MPa, wherein the main body (2200) has at least in sections and preferably along more than 50% of the length (ML) of the main body (2200) and most preferably entirely a bandlike shape (2214), wherein the band like shape (2214) forms a cross-section having a width (W) and a depth (D), wherein width (W) is at least 2 times depth (D) and preferably at least 3 times and highly preferably at least 5 times and most preferably up to or exactly or more than 10 times, wherein width (W) is smaller than 1.5 cm and depth (D) is larger than 3.0 cm wherein each SiC growth substrate (857) is coupled between at least one first metal electrode (206a) and at least one second metal electrode (206b) for heating the outer surface of the SiC growth substrates (857) or the surface of the deposited SiC to temperatures between 1300°C and 1800°C, in particular by means of resistive heating and preferably by internal resistive heating, wherein the first metal electrodes (206a) and the second metal electrodes (206b) are preferably shielded from the reaction space (966).

38. Method according to of claim 37, characterized in that the defined volume section (2202) is preferably formed between a first plane (2204) and a second plane (2206), wherein the first plane (2204) is perpendicular to the main body length (ML) and wherein the second plane (2206) is perpendicular to the main body length (ML), wherein the distance (2208) between the first plane (2204) and the second plane (2206) is at least 5% of the main body length (ML) and/or the main body (2200) is configured to resist forces generated during growth of the SiC crust (211) having a minimal thickness of at least 3cm for preventing cracking of the main body (2200) due to the generated forces.

39. Method according to of claim 38, characterized in that the main body (2200) is configured to resist forces generated during growth of the SiC crust (211) having a minimal thickness of at least 5cm for preventing cracking of the main body (2200) due to the generated forces.

40. Method according to of claim 38, characterized in that the main body (2200) has at least in sections and preferably along more than 50% of the length of the main body (2200) and most preferably entirely a tubular shape (2220), wherein the tubular shape (2220) forms a cross-section having an average wall thickness respectively depth (D) of less than 5cm and preferably of less than 2cm and particular preferably of less than 1cm and most preferably of less than 0,5cm, in particular less than 3mm or less than 2mm or less than 1mm.

41. Method according to any of claims 38 to 40, characterized in that the main body (2200) is a single piece (2222).

42. Method according to any of claims 38 to 41, characterized in that the main body (2200) is formed by multiple pieces (2224), wherein the multiple pieces are coupled to each other by means of a form closure and/or a force closure.

43. Method according to any of claims 38 to 42, characterized in that the main body (2200) is formed by multiple pieces (2224a, 2224b), wherein at least some and preferably most and highly preferably all of the multiple pieces (2224a, 2224b) are made of a material having a first Coefficient of Thermal Expansion (CTE), wherein the first Coefficient of Thermal Expansion is different to a Coefficient of Thermal Expansion of polycrystalline SiC.

44. Method according to claim 43, characterized in that the multiple pieces (2224) comprise at least two pieces (2224a) of a main piece type and at least one piece of a connecting piece type (2224b), wherein the at least two main pieces (2224a) are coupled by the at least one connecting piece (2224b), wherein the pieces of the main piece type (2224a) have a tubular-like (2220) or rod-like (2218) or blade-like shape (2214) and wherein at least most of the pieces (2224a) of the main piece type are longer compared to the pieces (2224b) of the connecting piece type.

45. Method according to claim 43, characterized in that the length of each of the at least two pieces (2224a) of the main piece type is below 100cm and above 5cm and that at least two pieces of the main piece type (2224a) are made of graphite.

46. Method according to claim 43 or 44 or 45, characterized in that a first piece (2224a) of the at least two pieces of the main piece type has a first central axis (2230) and a second piece (2224a) of the at least two pieces of the main piece type has a second central axis (2232), wherein the first central axis (2230) and the second central axis (2232) are arranged parallel to each other.

47. Method according to any of claims 37 to 46, characterized in that the main body (2200) forms a U-shape.

48. Method according to any of claims 37 to 47 characterized in that the at least one first metal electrode (206a) and at least one second metal electrode (206b) are connected to an alternating current source, wherein the alternating current source is configured to set up a frequency of the alternating current above 5Hz or preferably above 20Hz or highly preferably above 50Hz or most preferably above 500Hz or up to 5000Hz, in particular up to 2000Hz or up to 1000Hz or up to 500kHz or up to 2MHz.

49. System comprising a CVD SiC production reactor (850), in particular as described in any of claims 27 to 31 or as described in any of claims 32 to 36 or as described in any of claims 37 to 48, for providing a vent gas mixture and for producing SiC and a bed reactor, in particular a fixed bed reactor or a fluidized bed reactor, for generating Chlorosilanes by reacting at least one fraction of the vent gas mixture and Si, wherein further fractions of the vent gas mixture at least comprise H2 and a C-bearing molecule, in particular methane, and wherein Si is provided as solid inside the bed reactor and a separating unit (602), in particular a distillation column, for separating one or multiple metals, in particular B, Al, Fe and/or P, from generated Chlorosilanes, in particular STC and/or TCS.

50. Method for the production of SiC

At least comprising the steps: Providing a vent gas mixture (2400), wherein the vent gas mixture (2400) is preferably generated during SiC production and highly preferably generated during CVD SiC production,

Generating Chlorosilanes (2394) by reacting at least one fraction of the vent gas mixture and Cl (chlorine), wherein the at least one fraction of the vent gas mixture reacting with Cl is TCS, wherein further fractions (2401) of the vent gas mixture (2400) at least comprise H2 (2402) and methane (2404), wherein Cl is provided inside the bed reactor, Forwarding the Chlorosilanes (2394) and the further fraction (2401) of the vent gas mixture (2400) to a separating unit (602) for separating the Chlorosilanes (2394) and the further fraction (2401) of the vent gas mixture (2400) into a first fluid (624) and into a second fluid (626), wherein the first fluid (624) comprises the Chlorosilanes (2394), wherein a first storage and/or conducting element (2412) for storing or conducting the first fluid (624) is part of the separating unit (602) or coupled with the separating unit (602) and wherein a second storage and/or conducting element (2414) for storing or conducting the second fluid (626) is part of the separating unit (602) or coupled with the separating unit (602)

Forwarding at least the Chlorosilanes (2394) into a process chamber (856) of the CVD SiC production reactor (850), and

Forwarding at least one C-bearing molecule into the CVD SiC production reactor (850), Producing SiC inside the process chamber (856) of the CVD SiC production reactor (850) by depositing Si from the Chlorosilanes and C from the at least one C-bearing molecule on at least one deposition surface.

51. System comprising a CVD SiC production reactor (850), in particular as described in any of claims 27 to 31 or as described in any of claims 32 to 36 or as described in any of claims 37 to 48, for providing a vent gas mixture and for producing SiC and a bed reactor, in particular a fixed bed reactor or a fluidized bed reactor, for generating Chlorosilanes by reacting at least one fraction of the vent gas mixture and Cl, wherein TCS is provided as one fraction of a vent gas provided by the CVD SiC production reactor (850), wherein the further fractions of the vent gas mixture at least comprise H2 and methane and wherein Cl (chlorine) is provided inside the bed reactor.

52. Method according to any of claims 1 to 48 characterized in that

The step of providing the vent gas mixture (2400) respectively the step of operating the CVD SiC production providing the vent gas mixture takes place in the same facility and parallel to respectively at least temporarily at the same time the generating of Chlorosilanes (2394) inside the reactor chamber takes place.

53. Method according to any of claims 1 to 48 or 52, characterized in that the fourth fraction of the vent gas mixture (2400) that is forwarded into the reactor chamber comprises preferably more than 0.1 or 0.3 or 0.5 or 0.8 or 1 mass percent and highly preferably more than 2 or 3 or 4 or 5 mass percent and most preferably more than 10 mass percent of the mass sum of all vent gas mixture fractions which are forwarded into the reactor chamber.

54. Method according to any of claims 1 to 48 or 52 or 53, characterized in that the mass content of carbon in all vent gas mixture fractions forwarded into the reactor chamber is preferably larger than 1 ppma or larger than 50ppma and preferably larger than 100ppma or larger than 300 ppma or larger than 500 ppma or larger than 700 ppma or larger than 900 ppma or larger than 1000 ppma and particular preferably larger than 3000 ppma or larger than 5000 ppma or larger than 7000 ppma most preferably larger than 10.000 ppma.