Single-crystal silicon carbide wafer, single-crystal silicon carbide ingot, and method for producing single-crystal silicon carbide
AssigneeCentral Glass Company, Limited
InventorsTomonori Umezaki, Kazuto Kumagai, Gaku Kono
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Abstract
A single-crystal silicon carbide wafer (31) of the present invention includes boron at a concentration of 1.0×1016 atoms/cm3 or less, and has a central region (33) whose basal plane dislocation density is 100/cm2 or less on the surface. The central region (33) includes the center of the surface of the single-crystal silicon carbide wafer (31). An area of the central region (33) is one fourth or more of an area of the surface of the single-crystal silicon carbide wafer (31).
Claims20
A single-crystal silicon carbide wafer,
- wherein boron is included at a concentration of 1.0×1016 atoms/cm3 or less in the single-crystal silicon carbide wafer,
- a region having a basal plane dislocation density of 100 counts/cm2 or less is present on a surface of the single-crystal silicon carbide wafer,
- the region includes a center of the surface, and
- an area of the region is one fourth or more of an area of the surface.
A single-crystal silicon carbide ingot having a substantially circular columnar shape or a substantially polygonal columnar shape, wherein
- boron is included at a concentration of 1.0×1016 atoms/cm3 or less in a wafer cut perpendicular to a crystal growth direction,
- a region having a basal plane dislocation density of 100 counts/cm2 or less is present on a surface of the wafer,
- the region includes a center of the surface, and
- an area of the region is one fourth or more of an area of the surface.
A method for producing a single-crystal silicon carbide, the method comprising bringing a seed crystal of silicon carbide into contact with a raw material solution including silicon and carbon from above to grow the crystal, wherein
- the method has a heating step of heating a member to be used in a step of growing the crystal before the step of growing the crystal, and
- in the step of growing the crystal, a temperature T1 of a crystal growth interface P1 and a temperature T2 of the solution at a point P2 having a distance of 5 mm from the growth interface satisfy T2>T1, and a temperature gradient between P1 and P2 is more than 0 K/cm and 40 K/cm or less.
Dependencies are inferred from the claim text.