Seed crystal holders and seed crystals for fabricating silicon carbide crystals and methods of fabricating silicon carbide crystals
AssigneeCree, Inc.
InventorStephan Mueller
Life of this patent
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Abstract
Methods for producing silicon carbide crystals, seed crystal holders and seed crystal for use in producing silicon carbide crystals and silicon carbide crystals are provided. Silicon carbide crystals are produced by forcing nucleation sites of a silicon carbide seed crystal to a predefined pattern and growing silicon carbide utilizing physical vapor transport (PVT) so as to provide selective preferential growth of silicon carbide corresponding to the predefined pattern. Seed holders and seed crystals are provided for such methods. Silicon carbide crystals having regions of higher and lower defect density are also provided.
Claims54
A method of producing silicon carbide crystals, comprising:
- forcing nucleation sites of a silicon carbide seed crystal to a predefined pattern;
- and
- growing silicon carbide utilizing physical vapor transport (PVT) so as to provide selective preferential growth of silicon carbide corresponding to the predefined pattern.
A seed crystal holder for growing silicon carbide using physical vapor transport, comprising:
- a body section configured to hold a silicon carbide seed crystal;
- and
- a plurality of regions of differing thermal conductivity in the graphite body section, the regions of differing thermal conductivity having a predefined pattern.
A silicon carbide seed crystal, comprising:
- a silicon carbide crystal having a first surface and a second surface, opposite the first surface;
- and
- a pattern in the second surface so as to provide a plurality of regions of silicon carbide which extend a first distance form the first surface of the silicon carbide crystal and a plurality of other regions which extend a second distance, different from the first distance, from the first surface of the silicon carbide crystal.
A silicon carbide seed crystal, comprising:
- a silicon carbide crystal having a first surface and a second surface, opposite the first surface;
- and
- regions of a material other than silicon carbide on the second surface of the silicon carbide crystal, the material other than silicon carbide having a sticking coefficient associated with vapor phase transport growth of silicon carbide which is less than a sticking coefficient of precursors of silicon carbide.
A silicon carbide crystal comprising:
- first regions of silicon carbide having a first defect density;
- and
- second regions of silicon carbide having a second defect density, the second defect density being less that the first defect density.
Dependencies are inferred from the claim text.