Furnace apparatus for crystal production

A furnace apparatus for growing SiC crystals,

• comprising
• a furnace unit,
• wherein the furnace unit comprises a furnace housing with an outer surface and an inner surface,
• at least one crucible unit
• wherein the crucible unit is arranged inside the furnace housing,
• wherein the crucible unit comprises a crucible housing,
• wherein the housing has an outer surface and an inner surface,
• wherein the inner surface at least partially defines a crucible volume,
• wherein a receiving space for receiving a solid SiC source material is arranged or formed inside the crucible volume,
• wherein a seed holder unit for holding a defined seed wafer is arranged inside the crucible volume,
• wherein the furnace housing inner wall and the crucible housing outer wall define a furnace volume,
• at least one heating unit for heating the source material,
• wherein the receiving space for receiving the source material is at least in parts arranged below the seed holder unit,
• characterized in that
• a crucible gas flow unit is provided for causing gas flow along a gas flow path inside the crucible volume, wherein the gas flow unit comprises a crucible gas inlet tube for conducting gas into the crucible volume and a crucible gas outlet tube for removing gas conducted into the crucible volume via the crucible gas inlet tube from the crucible volume,
• a filter unit is arranged inside the crucible volume between the crucible gas inlet tube and the crucible gas outlet tube for capturing at least Si2C sublimation vapor, SiC2 sublimation vapor and Si sublimation vapor,
• the gas flow path extends through the filter unit,
• the filter unit is arranged between a crucible lower housing and a crucible upper housing, wherein the filter body forms a filter outer surface, wherein the filter outer surface connects the crucible lower housing and the crucible upper housing, wherein the filter outer surface forms a portion of the outer surface of crucible housing, and
• the filter body forms a filter inner surface, wherein the filter inner surface forms a filter through hole.

A furnace apparatus for growing SiC crystals,

• comprising
• a furnace unit,
• wherein the furnace unit comprises a furnace housing with an outer surface and an inner surface,
• at least one crucible unit
• wherein the crucible unit is arranged inside the furnace housing,
• wherein the crucible unit comprises a crucible housing,
• wherein the housing has an outer surface and an inner surface,
• wherein the inner surface at least partially defines a crucible volume,
• wherein a receiving space for receiving a solid SiC source material is arranged or formed inside the crucible volume,
• wherein a seed holder unit for holding a defined seed wafer is arranged inside the crucible volume,
• wherein the furnace housing inner wall and the crucible housing outer wall define a furnace volume,
• at least one heating unit for heating the source material,
• wherein the receiving space for receiving the source material is at least in parts arranged below the seed holder unit,
• characterized in that
• a crucible gas flow unit is provided for causing gas flow along a gas flow path inside the crucible volume, wherein the gas flow unit comprises a crucible gas inlet tube for conducting gas into the crucible volume and a crucible gas outlet tube for removing gas conducted into the crucible volume via the crucible gas inlet tube from the crucible volume,
• a filter unit is arranged inside the crucible volume between the crucible gas inlet tube and the crucible gas outlet tube for capturing at least Si2C sublimation vapor, SiC2 sublimation vapor and Si sublimation vapor,
• the gas flow path extends through the filter unit,
• the receiving space is located between the crucible gas inlet tube and the seed holder unit for conducting gas flow around the receiving space and/or through the receiving space,
• a source material holding plate is provided, wherein the source material holding plate comprises an upper surface forming a bottom section of the receiving space and a lower surface forming a source-material-holding-plate-gas-flow-path-boundary-section,
• the source-material-holding-plate comprises multiple through holes, wherein the multiple through holes extend from the upper surface of the source-material-holding-plate through a main body of the source-material-holding-plate to the lower surface of source-material-holding-plate, wherein at least the majority of the multiple through holes has a diameter of less than 12 mm.