SiC WAFER AND MANUFACTURING METHOD OF SiC WAFER
In a SiC wafer, a difference between a threading dislocation density of threading dislocations exposed on a first surface and a threading dislocation density of threading dislocations exposed on a second surface is 10% or less of the threading dislocation density of the surface with a higher threading dislocation density among the first surface and the second surface, and 90% or more of the threading dislocations exposed on the surface with a higher threading dislocation density among the first surface and the second surface extend to the surface with a lower threading dislocation density.
1 . A SiC wafer, wherein
a difference between a threading dislocation density of threading dislocations exposed on a first surface and a threading dislocation density of threading dislocations exposed on a second surface is 10% or less of the threading dislocation density of the surface with a higher threading dislocation density among the first surface and the second surface, and
90% or more of the threading dislocations exposed on the surface with a higher threading dislocation density among the first surface and the second surface extend to the surface with a lower threading dislocation density.
2 . The SiC wafer according to claim 1 ,
wherein the numbers of the threading dislocations of the first surface and the second surface are substantially the same.
3 . The SiC wafer according to claim 1 ,
wherein a density of the threading dislocations exposed on the surface with a higher threading dislocation density among the first surface and the second surface is 1.5 threading dislocations/mm 2 or less.
4 . The SiC wafer according to claim 1 ,
wherein the difference between the threading dislocation density exposed on the first surface and the threading dislocation density exposed on the second surface is 0.02 threading dislocations/mm 2 or less.
5 . A manufacturing method of a SiC wafer, comprising:
a preparation step of producing a seed crystal having a surface density of threading dislocations of 1.5 threading dislocations/mm 2 or less;
a crystal growth step of performing crystal growth so that a diameter of a crystal does not increase from the seed crystal in a crucible and a crystal growth surface and an isotherms in the crucible are parallel to each other; and
a cutting step of slicing a SiC ingot obtained in the crystal growth step.
6 . The SiC wafer according to claim 2 ,
wherein a density of the threading dislocations exposed on the surface with a higher threading dislocation density among the first surface and the second surface is 1.5 threading dislocations/mm 2 or less.
7 . The SiC wafer according to claim 2 ,
wherein the difference between the threading dislocation density exposed on the first surface and the threading dislocation density exposed on the second surface is 0.02 threading dislocations/mm 2 or less.
8 . The SiC wafer according to claim 6 ,
wherein the difference between the threading dislocation density exposed on the first surface and the threading dislocation density exposed on the second surface is 0.02 threading dislocations/mm 2 or less.