US 12,234,571 B2
SiC single crystal substrate
Tomohiro Shonai, Tokyo (JP)
Assigned to Resonac Corporation, Tokyo (JP)
Filed by Resonac Corporation, Tokyo (JP)
Filed on May 31, 2023, as Appl. No. 18/326,109.
Claims priority of application No. 2022-090472 (JP), filed on Jun. 2, 2022.
Prior Publication US 2023/0392285 A1, Dec. 7, 2023
Int. Cl. H01L 29/16 (2006.01); C30B 29/06 (2006.01); C30B 29/60 (2006.01); C30B 33/10 (2006.01)
CPC C30B 29/06 (2013.01) [C30B 29/60 (2013.01); C30B 33/10 (2013.01); H01L 29/1608 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A SiC single crystal substrate, wherein a main plane of the SiC single crystal substrate has an off angle of 0° to 6° to the (0001) plane in the <11-20> direction and an off angle of 0° to 0.5° to the (0001) plane in the <1-100> direction, and includes non-MP defects wherein when a Si surface is etched in molten KOH at 500° C. for 15 minutes, the non-MP defects that appear by etching are hexagonal and have no core, an area of an observed etch pit of a non-MP defect is more than 10% larger than that of an observed etch pit of a threading screw dislocation (TSD) and is less than 110% of that of an observed etch pit of a micropipe (MP), and a transmission X-ray topography image of the non-MP defect is distinguishable from a transmission X-ray topography image of the micropipe (MP),
wherein when the substrate is divided into a central region within the range of r/2 (where r is the radius of the substrate) from the center of the substrate and an outer region located outside the central region, the density (NA) of etch pits, which are identified as the non-MP defects in the central region, and the density (NB) of etch pits, which are identified as the non-MP defects in the outer region, satisfy the following relationship:
0.01<NP<0.5(where NP={NA/(NA+NB)}).