Granted Patent B2

US 12,234,571 · App. 18/326,109 · Granted Feb 25, 2025

Inventor: Tomohiro Shonai (Tokyo, JP)

Assignee: Resonac Corporation

C30B29/06C30B29/60C30B33/10H01L29/1608

Abstract

Claims (11)

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 )}).

2. The SiC single crystal substrate according to claim 1 , wherein the density of etch pits, which are identified as the non-MP defects, is in a range of 0.1/cm 2 to 50/cm 2 .

3. The SiC single crystal substrate according to claim 2 , wherein the density of etch pits, which are identified as the non-MP defects, is in a range of0.9/cm 2 to 50/cm 2 .

4. The SiC single crystal substrate according to claim 3 , wherein the diameter of the SiC single crystal substrate is in a range of 145 mm to 155 mm.

5. The SiC single crystal substrate according to claim 3 , wherein the diameter of the SiC single crystal substrate is in a range of 190 mm to 205 mm.

6. The SiC single crystal substrate according to claim 2 , wherein the diameter of the SiC single crystal substrate is in a range of 145 mm to 155 mm.

7. The SiC single crystal substrate according to claim 2 , wherein the diameter of the SiC single crystal substrate is in a range of 190 mm to 205 mm.

8. A SiC single crystal substrate, wherein the 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 the 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, the area of an observed etch pit of the 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 the micropipe (MP), and a transmission X-ray topography image of the non-MP defect is distinguishable from the transmission X-ray topography image of the micropipe (MP), wherein a density of the etch pits, which are identified as the non-MP defects, is in a range of 0.01/cm 2 to 50/cm 2 , and 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 )}).

Assignments (2)

Priority Claims (1)

Continuity (1)

References Cited (29)