Method and Device for Producing a SiC Solid Material

Abstract

The present invention relates to a method for producing a preferably elongated SiC solid, in particular of polytype 3C. The method according to the invention preferably includes at least the following steps: introducing at least a first source gas into a process chamber, said first source gas including Si, introducing at least one second source gas into the process chamber, the second source gas including C, electrically energizing at least one separator element disposed in the process chamber to heat the separator element, setting a deposition rate of more than 200 μm/h, where a pressure in the process chamber of more than 1 bar is generated by the introduction of the first source gas and/or the second source gas, and where the surface of the deposition element is heated to a temperature in the range between 1300° C. and 1800° C.

1 - 60 . (canceled) 
     
     
         61 . SiC production reactor ( 850 ),
 at least comprising   a process chamber ( 856 ), wherein the process chamber ( 856 ) is at least surrounded by   a base plate ( 862 ), a side wall section ( 864   a ) and a top wall section ( 864   b ),   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 one feed-medium source ( 851 ), 
 wherein a Si and C feed-medium source ( 851 ) provides at least Si and C, in particular SiCl3(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 coupled with at least two feed-medium sources ( 851 ,  852 ), 
 wherein a Si feed medium source ( 851 ) provides 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 ) 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 first power connection ( 859   a ) and a second power connection ( 859   b ),   wherein the first power connections ( 859   a ) are first metal electrodes ( 206   a ) and wherein the second power connections ( 859   b ) are second metal electrodes ( 206   b ),   wherein the first metal electrodes ( 206   a ) and the second metal electrodes ( 206   b ) are preferably shielded from the reaction space,   wherein each SiC growth substrate ( 857 ) is coupled between at least one first metal electrode ( 206   a ) and at least one second metal electrode ( 206   b ) 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 base plate ( 862 ) comprises at least one cooling element ( 868 ,  870 ,  880 ), in particular a base cooling element, for preventing heating of the base plate ( 862 ) above a defined temperature 
 and/or 
 wherein the side wall section ( 864   a ) comprises at least one cooling element ( 868 ,  870 ,  880 ), in particular a bell jar cooling element, for preventing heating the side wall section ( 864   a ) above a defined temperature 
 and/or 
 wherein the top wall section ( 864   b ) comprises at least one cooling element ( 868 ,  870 ,  880 ), in particular a bell jar cooling element, for preventing heating the top wall section ( 864   b ) above a defined temperature. 
   
     
     
         62 . SiC production reactor according to  claim 61   characterized in that   the cooling element ( 868 ) is an active cooling element ( 870 ).   
     
     
         63 . SiC production reactor according to  claim 62   characterized in that   the base plate ( 862 ) and/or side wall section ( 864   a ) and/or top wall section ( 864   b ) 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 to limit heating of the base plate ( 862 ) and/or side wall section ( 864   a ) and/or top wall section ( 864   b ) to a temperature below 1000° C., wherein   a base plate and/or side wall section and/or top wall section sensor unit ( 890 ) is provided to detect temperature of the base plate ( 862 ) and/or side wall section ( 864   a ) and/or top wall section ( 864   b ) and to output a temperature signal or temperature data and/or a cooling fluid temperature sensor is provided to detect the temperature of the cooling fluid,   and   a fluid forwarding unit ( 873 ) is 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 ),   wherein the cooling fluid is water or oil.   
     
     
         64 . SiC production reactor according to  claim 61   characterized in that   the cooling element ( 868 ) is a passive cooling element ( 880 ).   
     
     
         65 . SiC production reactor according to  claim 64 ,
 characterized in that   the cooling element ( 868 ) is at least partially formed by a polished steel surface ( 865 ) of the base plate ( 862 ), the side wall section ( 864   a ) and/or the top wall section ( 864   b ),   wherein   the cooling element ( 868 ) is a coating ( 867 ), wherein the coating is ( 867 ) formed on top of the polished steel surface ( 865 ) and wherein the coating ( 867 ) is configured to reflect heat, wherein   the coating ( 867 ) is a metal coating or a comprises metal, in particular silver or gold or chrome, or alloy coating, in particular a CuNi alloy, wherein   the emissivity of the polished steel surface ( 865 ) and/or of the coating ( 867 ) is below 0.3, in particular below 0.1 or below 0.03.   
     
     
         66 . SiC production reactor according to  claim 61 ,
 characterized in that   the side wall section ( 864   a ) and the top wall section ( 864   b ) are formed by a bell jar ( 864 ), wherein the bell jar ( 864 ) is preferably movable with respect to the base plate ( 862 ), wherein   more than 50% [mass] of the side wall section ( 864   a ) and/or more than 50% [mass] of the top wall section ( 864   b ) and/or more than 50% [mass] of the base plate ( 862 ) is made of metal, in particular steel.   
     
     
         67 . SiC production reactor according to  claim 61 ,
 characterized in that   the SiC growth substrate ( 857 ) has an average perimeter of at least 5 cm around a cross-sectional area ( 218 ) orthogonal to the length direction of the SiC growth substrate ( 857 ) or multiple SiC growth substrates ( 857 ) have an average perimeter per SiC growth substrate ( 857 ) of at least 5 cm around a cross-sectional area ( 218 ) orthogonal to the length direction of the respective SiC growth substrate ( 857 ).   
     
     
         68 . SiC production reactor according to  claim 67 ,
 characterized in that   the SiC growth substrate ( 857 ) comprises or consists of SiC or C, in particular graphite, or wherein multiple SiC growth substrates ( 857 ) comprise or consist of SiC or C, in particular graphite and/or   the shape of the cross-sectional area ( 218 ) orthogonal to the length direction of the SiC growth substrate ( 857 ) differs at least in sections and preferably along more than 50% of the length of the SiC growth substrate ( 857 ) and highly preferably along more than 90% of the length of the SiC growth substrate ( 857 ) from a circular shape and/or   a ratio U/A between the cross-sectional area A ( 218 ) and the perimeter U ( 226 ) around the cross-sectional area ( 218 ) is higher than 1.2 1/cm and preferably higher than 1.5 1/cm and highly preferably higher than 2 1/cm and most preferably higher than 2.5 1/cm.   
     
     
         69 . SiC production reactor according to  claim 61 ,
 characterized in that   the SiC growth substrate ( 857 ) is formed by at least one carbon ribbon or plate ( 882 ), in particular graphite ribbon, wherein the at least one carbon ribbon ( 882 ) comprises a first ribbon end ( 884 ) and a second ribbon end ( 886 ), wherein the first ribbon end ( 882 ) is coupled with the first metal electrode ( 206   a ) and wherein the second ribbon end ( 886 ) is coupled with the second metal electrode ( 206   b )   or   wherein each of multiple the SiC growth substrates ( 857 ) is formed by at least one carbon ribbon or plate ( 882 ), in particular graphite ribbon, wherein the at least one carbon ribbon ( 882 ) per SiC growth substrate ( 857 ) comprises a first ribbon end ( 884 ) and a second ribbon end ( 886 ), wherein the first ribbon end ( 884 ) is coupled with the first metal electrode ( 206   a ) of the respective SiC growth substrate ( 857 ) and wherein the second ribbon end ( 886 ) is coupled with the second metal electrode ( 206   b ) of the respective SiC growth substrate ( 857 ).   
     
     
         70 . SiC production reactor according to  claim 61 ,
 characterized in that   the SiC growth substrate ( 857 ) is formed by multiple rods or plates ( 894 ,  896 ,  898 ), wherein each rod or plate ( 894 ,  896 ,  898 ) has a first rod or plate end ( 899 ) and a second rod or plate end ( 900 ), wherein all first rod or plate ends ( 899 ) are coupled with the same first metal electrode ( 206   a ) and wherein all second rod or plate ends ( 900 ) are coupled with the same second metal electrode ( 206   b )   or   wherein each of multiple SiC growth substrates ( 857 ) is formed by multiple rods or plates ( 894 ,  896 ,  898 ), wherein each rod or plate ( 894 ,  896 ,  898 ) has a first rod or plate end ( 899 ) and a second rod or plate end ( 900 ), wherein all first rod or plate ends ( 899 ) are coupled with the same first metal electrode ( 206   a ) of the respective SiC growth substrate ( 857 ) and wherein all second rod ends or plates ( 900 ) are coupled with the same second metal electrode ( 206   b ) of the respective SiC growth substrate ( 857 ).   
     
     
         71 . SiC production reactor according to  claim 61 ,
 characterized in that   the SiC growth substrate ( 857 ) is formed by at least one metal rod ( 902 ), wherein the metal rod ( 902 ) has a first metal rod end ( 904 ) and a second metal rod end ( 906 ), wherein the first metal rod end ( 904 ) is coupled with the first metal electrode ( 206   a ) and wherein the second metal rod end ( 906 ) is coupled with the second metal electrode ( 206   b )   or   wherein each of multiple SiC growth substrates ( 857 ) is formed by at least one metal rod ( 902 ), wherein each metal rod ( 902 ) has a first metal rod end ( 904 ) and a second metal rod end ( 906 ), wherein the first metal rod end ( 904 ) is coupled with the first metal electrode ( 206   a ) of the respective SiC growth substrate ( 857 ) and wherein the second metal rod end ( 906 ) is coupled with the second metal electrode ( 206   b ) of the respective SiC growth substrate ( 857 ).   
     
     
         72 . SiC production reactor according to any of  claim 61 ,
 characterized by   a gas outlet unit for outputting vent gas   a vent gas recycling unit,   wherein the vent gas recycling unit is connected to the gas outlet unit,   wherein the vent gas recycling unit comprises at least   a separator unit for separating the vent gas into a first fluid and into a second fluid,   wherein the first fluid is a liquid and wherein the second fluid is a gas,   wherein a first storage and/or conducting element for storing or conducting the first fluid is part of the separator unit or coupled with the separator unit   and   wherein a second storage and/or conducting element for storing or conducting the second fluid is part of the separator unit or coupled with the separator unit.   
     
     
         73 . SiC production reactor according to  claim 72 ,
 characterized in that   the vent gas recycling unit comprises a further separator unit for separating the first fluid into   at least two parts, wherein the two parts are
 a mixture of chlorosilanes and 
 a mixture of HCl, H2 and at least one C-bearing molecule, 
   and preferably into at least three parts, wherein the three parts are
 a mixture of chlorosilanes and 
 HCl and 
 a mixture of H2 and at least one C-bearing molecule, 
   wherein the first storage and/or conducting element connects the separator unit with the further separator unit,   wherein the further separator unit is coupled with a mixture or chlorosilanes storage and/or conducting element and with a HCl storage and/or conducting element and with a H2 and C storage and/or conducting element,   wherein the mixture of chlorosilanes storage and/or conducting element forms a section of a mixture of chlorosilanes mass flux path for conducting the mixture of chlorosilanes into the process chamber,   wherein a Si mass flux measurement unit for measuring an amount of Si of the mixture of chlorosilanes is provided as part of the mass flux path prior to the process chamber, in particular prior to a mixing device ( 854 ), and preferably as further Si feed-medium source providing a further Si feed medium.   
     
     
         74 . PVT source material production method for the production of PVT source material consisting of SiC, in particular of polytype 3C, at least comprising the steps of:
 Providing a source medium inside a process chamber ( 856 ), wherein the process chamber ( 856 ) is at least surrounded by a base plate ( 862 ), a side wall section ( 864   a ) and a top wall section ( 864   b ),
 wherein the base plate ( 862 ) comprises at least one cooling element ( 868 ,  870 ,  880 ) for preventing heating the base plate ( 862 ) above a defined temperature 
 and/or 
 wherein the side wall section ( 864   a ) comprises at least one cooling element ( 868 ,  870 ,  880 ) for preventing heating the side wall section above a defined temperature 
 and/or 
 wherein the top wall section ( 864   b ) comprises at least one cooling element ( 868 ,  870 ,  880 ) for preventing heating the top wall section ( 864   b ) above a defined temperature 
   Electrically energizing at least one SiC growth substrate ( 857 ) and preferably a plurality of SiC growth substrates ( 857 ), disposed in the process chamber ( 856 ) to heat the SiC growth substrate/s ( 857 ) to a temperature in the range between 1300° C. and 2000° C.,
 wherein each SiC growth substrate ( 857 ) comprises a first power connection ( 859   a ) and a second power connection ( 859   b ),
 wherein the first power connections ( 859   a ) are first metal electrodes ( 206   a ) and wherein the second power connections ( 859   b ) are second metal electrodes ( 206   b ),
 wherein the first metal electrodes ( 206   a ) and the second metal electrodes ( 206   b ) are preferably shielded from a reaction space of the process chamber ( 857 ), 
 
 
   and   Setting a deposition rate, in particular of more than 200 μm/h, for removing Si and C from the source medium and for depositing the removed Si and C as SiC, in particular as polycrystalline SiC, on the SiC growth substrate/s ( 857 ) and thereby forming a SiC solid ( 921 )   and   preventing heating of the base plate ( 862 ) and/or the side wall section ( 864   a ) and/or the top wall section ( 864   b ) above a defined temperature, in particular 1000° C.   
     
     
         75 . PVT source material production method according to  claim 74 ,
 characterized in that   more than 50% [mass] of the side wall section ( 864   a ) and more than 50% [mass] of the top wall section ( 864   b ) and more than 50% [mass] of the base plate ( 862 ) is made of metal, in particular steel, wherein   a base plate and/or side wall section and/or top wall section sensor unit ( 890 ) is provided to detect temperature of the base plate ( 862 ) and/or side wall section ( 864   a ) and/or top wall section ( 864   b ) and to output a temperature signal or temperature data and/or a cooling fluid temperature sensor is provided to detect the temperature of the cooling fluid,   and   a fluid forwarding unit ( 873 ) is provided for forwarding the cooling fluid through the fluid guide unit ( 872 ,  874 ,  876 ),wherein the fluid forwarding unit ( 873 ) is 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 ), wherein   the step of providing a source medium inside a process chamber ( 856 ) comprises introducing at least a first feed-medium, in particular a first source gas, into the process chamber, said first feed medium comprises Si, wherein the first-feed medium has a purity which excludes at least 99.9999% (ppm wt) of the substances B, Al, P, Ti, V, Fe, Ni,
 and 
   introducing at least a second feed-medium, in particular a second source gas, into the process chamber ( 856 ), the second feed medium comprises C, in particular natural gas, Methane, Ethane, Propane, Butane and/or Acetylene, wherein the second-feed medium has a purity which excludes at least 99.9999% (ppm wt) of the substances B, Al, P, Ti, V, Fe, Ni, and   introducing a carrier gas, wherein the carrier gas has a purity which excludes at least 99.9999% (ppm wt) of the substances B, Al, P, Ti, V, Fe, Ni,   or   introducing one feed-medium in particular a source gas, into the process chamber ( 856 ), said feed medium comprises Si and C, in particular SiCl3(CH3), wherein the feed medium has a purity which excludes at least 99.9999% (ppm wt) of the substances B, Al, P, Ti, V, Fe, Ni, and   introducing a carrier gas, wherein the carrier gas has a purity which excludes at least 99.9999% (ppm wt) of the substances B, Al, P, Ti, V, Fe, Ni.   
     
     
         76 . PVT source material production method,
 characterized by   setting a pressure inside the process chamber ( 856 ) above 1 bar by introducing a defined amount of a mixture of the first source gas, which provides Si, and the second source gas, which provides C, into the process chamber, wherein the defined amount is an amount between
 0.32 g of the mixture per hour and per cm2 of a SiC growth surface and 10 g of the mixture per hour and per cm2 of the SiC growth surface 
   or   setting a pressure inside the process chamber ( 856 ) above 1 bar by introducing a defined amount of a Si and C containing source gas into the process chamber, wherein the defined amount is an amount between
 0.32 g of the Si and C containing source gas per hour and per cm2 of the SiC growth surface and 10 g of the Si and C containing source gas per hour and per cm2 of the SiC growth surface. 
   
     
     
         77 . PVT source material production method according to  claim 74 ,
 characterized in that   the SiC growth substrate ( 857 ) has an average perimeter of at least 5 cm around a cross-sectional area ( 218 ) orthogonal to the length direction of the SiC growth substrate ( 857 ) or multiple SiC growth substrates ( 857 ) have an average perimeter per SiC growth substrate ( 857 ) of at least 5 cm around a cross-sectional area ( 218 ) orthogonal to the length direction of the respective SiC growth substrate ( 857 ), wherein   the SiC depositing on the SiC growth substrate ( 857 )   has impurities of less than 10 ppm (weight) of the substance N and of less than 1000 ppb (weight), in particular of less than 500 ppb (weight), of one or preferably multiple or highly preferably a majority or most preferably all of the substances B, Al, P, Ti, V, Fe, Ni, wherein the SiC depositing on the SiC growth substrate ( 857 ) has impurities of less than 2 ppm (weight) of the substance N and of less than 1000 ppb (weight), in particular of less than 500 ppb (weight), of the sum of all of the metals Ti, V, Fe, Ni.   
     
     
         78 . PVT source material production method according to  claim 74 ,
 characterized by   a gas outlet unit for outputting vent gas   a vent gas recycling unit,   wherein the vent gas recycling unit is connected to the gas outlet unit,   wherein the vent gas recycling unit comprises at least   a separator unit for separating the vent gas into a first fluid and into a second fluid,   wherein the first fluid is a liquid and wherein the second fluid is a gas,   wherein a first storage and/or conducting element for storing or conducting the first fluid is part of the separator unit or coupled with the separator unit   and   wherein a second storage and/or conducting element for storing or conducting the second fluid is part of the separator unit or coupled with the separator unit, wherein the step of providing a source medium inside a process chamber, comprises feeding the first fluid from the vent gas recycling unit into the process chamber, wherein the first fluid comprises at least a mixture of chlorosilanes.   
     
     
         79 . PVT source material production method according to  claim 74 ,
 characterized by   disaggregating the SiC solid ( 211 ) into SiC particles ( 920 ) having an average length of more than 100 μm.   
     
     
         80 . PVT source material produced by method according to  claim 79 , wherein the PVT source material ( 922 ) consists of SiC particles ( 920 ),
 wherein the average length of the SiC particles ( 920 ) is more than 100 μm and preferably more than 500 μm and highly preferably more than 1 mm and most preferably more than 2 mm,   wherein the SiC particles ( 920 ) have impurities of less than 10 ppm (weight) of the substance N and of less than 1000 ppb (weight), in particular of less than 500 ppb (weight), of each of the substances B, Al, P, Ti, V, Fe, Ni.   Ti.   
     
     
         81 . PVT source material ( 922 ) according to  claim 80 ,
 wherein the SiC particles have impurities of less than 10 ppm (weight) of the substance N and of less than 1000 ppb (weight), in particular of less than 500 ppb (weight), of the sum of all of the metals Ti, V, Fe, Ni.   
     
     
         82 . PVT source material according to  claim 80 ,
 characterized in that   the tapped density of the SiC particles ( 920 ) is above 1.8 g/cm3.   
     
     
         83 . PVT source material ( 922 ) produced according to  claim 74 , wherein the PVT source material forms a SiC solid ( 921 ), wherein the SiC solid ( 921 ) is
 characterized by   a mass of more than 1 kg,   a thickness of at least 1 cm,   a length of more than 50 cm   wherein the SiC solid has impurities of less than 10 ppm (weight) of the substance N and of less than 1000 ppb (weight), in particular of less than 500 ppb (weight), of the sum of all of the metals Ti, V, Fe, Ni,   wherein the SiC is SiC of polytype 3C and/or polycrystalline SiC.   
     
     
         84 . Method for the production of at least one SiC crystal ( 17 )
 comprising the steps   providing a PVT reactor ( 100 ) for the production of at least one SiC crystal ( 17 ),
 wherein the PVT reactor ( 100 ) comprises 
 a furnace unit ( 102 ), 
 wherein the furnace unit ( 102 ) comprises a furnace housing ( 108 ) with an outer surface ( 242 ) and an inner surface ( 240 ), 
 at least one crucible unit ( 106 ) 
 wherein the crucible unit ( 106 ) is arranged inside the furnace housing ( 108 ), 
 wherein the crucible unit ( 106 ) comprises a crucible housing ( 110 ), 
 wherein the crucible housing ( 110 ) has an outer surface ( 112 ) and an inner surface ( 114 ), wherein the inner surface ( 114 ) at least partially defines a crucible volume ( 116 ), 
 wherein a receiving space ( 118 ) for receiving a source material ( 120 ) is arranged or formed inside the crucible volume ( 116 ), 
 wherein a seed holder unit ( 122 ) for holding a defined seed wafer ( 18 ) is arranged inside the crucible volume ( 116 ), wherein the seed wafer holder ( 122 ) holds a seed wafer ( 18 ), 
 wherein the furnace housing inner wall ( 240 ) and the crucible housing outer wall ( 112 ) define a furnace volume ( 104 ), 
 at least one heating unit ( 124 ) for heating the source material ( 120 ), 
 wherein the receiving space ( 118 ) for receiving the source material ( 120 ) is at least in parts arranged above the heating unit ( 124 ) and below the seed holder unit ( 122 ), 
   adding PVT source material ( 922 ) according to claim  23  as source material ( 120 ) into the receiving space ( 118 ),   sublimating the added PVT source material ( 922 ) and   depositing the sublimated SiC on the seed wafer ( 18 ) and thereby forming the at least one or exactly one SiC crystal ( 17 ).