Patent DE-102009016132-A1 (DE)
Title: Producing silicon carbide volume single crystal, by disposing seed crystal in crystal growth region of growth crucible with initial growth surface and center central longitudinal axis and producing growth gas phase in crystal growth region
Inventor: STRAUBINGER THOMAS
IPC: C30B29/36
Filed: 2009-04-03
Abstract: The process comprises disposing a seed crystal in a crystal growth region (5) of a growth crucible (3) with initial growth surface and a center central longitudinal axis, where the seed diameter is 10% less than a crystal diameter of the volume single crystal to be produced, producing a growth gas phase in the crystal growth region and growing the volume single crystal by deposition from the growth gas phase, and feeding the growth gas phase partially from a powdered source material (6) made of silicon carbide or aluminum nitride present in a storage region (4) of the growth crucible. The process comprises disposing a seed crystal in a crystal growth region (5) of a growth crucible (3) with initial growth surface and a center central longitudinal axis, where the seed diameter is 10% less than a crystal diameter of the volume single crystal to be produced, producing a growth gas phase in the crystal growth region and growing the volume single crystal by deposition from the growth gas phase, feeding the growth gas phase partially from a powdered source material (6) made of silicon carbide or aluminum nitride present in a storage region (4) of the growth crucible, transferring the source material portion of the source material to the crystal growth region using a silicon carbide volume intermediate block (7) made of silicon carbide or aluminum nitride, acting as gas barrier and arranged between the storage region and the crystal growth region, and depositing the source material portion on a lower side of the silicon carbide volume intermediate block turned to the storage region and later again sublimating on an upper side of the silicon carbide volume intermediate block turned to the crystal growth region. A thickness of 10-50 mm measured in a growth direction of the growing-up volume single crystal oriented parallel to the central longitudinal axis is provided for the volume intermediate block. The crystal growth region and the storage region are heated independent of each other. A polycrystalline material structure is provided for the volume intermediate block. The volume intermediate block is kept in a constant distance to a growth boundary surface of the growing-up silicon carbide volume single crystal during the growth process, is secured against the slippage in the direction of the source material, and is used with a surface adapted to the growth boundary surface of the growing-up silicon carbide volume single crystal. The initial growth surface of the seed crystal is adapted to a driving force for the growth of the silicon carbide volume single crystal at a surface distribution adjusting itself to begin the growth of the silicon carbide volume single crystal. A growth rate of 2 mm/h is adjusted for the grown-up volume single crystal. An independent claim is included for a volume single crystal made of silicon carbide and aluminum nitride produced after a sublimation growth process.