US 11,862,684 B2
Recycle wafer of silicon carbide and method for manufacturing silicon carbide semiconductor device
Tsubasa Honke, Osaka (JP); and Kyoko Okita, Osaka (JP)
Assigned to Sumitomo Electric Industries, Ltd., Osaka (JP)
Appl. No. 17/420,416
Filed by SUMITOMO ELECTRIC INDUSTRIES, LTD., Osaka (JP)
PCT Filed Sep. 26, 2019, PCT No. PCT/JP2019/037837
§ 371(c)(1), (2) Date Jul. 2, 2021,
PCT Pub. No. WO2020/144900, PCT Pub. Date Jul. 16, 2020.
Claims priority of application No. 2019-001173 (JP), filed on Jan. 8, 2019.
Prior Publication US 2022/0085172 A1, Mar. 17, 2022
Int. Cl. H01L 29/16 (2006.01); H01L 21/02 (2006.01)
CPC H01L 29/1608 (2013.01) [H01L 21/02002 (2013.01); H01L 21/02378 (2013.01)] 6 Claims
OG exemplary drawing
 
1. A recycle wafer of silicon carbide comprising:
a silicon carbide substrate having a first main surface and a second main surface opposite to the first main surface; and
a first silicon carbide layer in contact with the first main surface, wherein
the silicon carbide substrate includes a substrate region that is within 10 μm from the first main surface toward the second main surface, and
in a direction perpendicular to the first main surface, a value obtained by subtracting a value that is three times a standard deviation of a nitrogen concentration in the substrate region from an average value of the nitrogen concentration in the substrate region is greater than a minimum value of a nitrogen concentration in the first silicon carbide layer.