SiC single crystal, SiC wafer, SiC substrate, and SiC device

Patent metadata

Field	Value
Publication number	US-10125435-B2
Application number	US-201414650169-A
Country	US
Kind code	B2
Filing date	Feb 7, 2014
Priority date	Feb 20, 2013
Publication date	Nov 13, 2018
Grant date	Nov 13, 2018

Abstract

A SiC single crystal includes, in a plane substantially parallel to a c-plane thereof, a region (A) in which edge dislocations having a Burgers vector (A) in a specific direction are unevenly distributed, and a region (B) in which basal plane dislocations having a Burgers vector (B) in a specific direction are unevenly distributed. The region (A) is located in a <1-100> direction with respect to a facet portion, while the region (B) is located in a <11-20> direction with respect to the facet portion. A SiC substrate is produced by cutting a SiC wafer from the SiC single crystal in a direction substantially parallel to the c-plane, and cutting the SiC substrate from the SiC wafer such that the SiC substrate mainly contains one of the region (A) and the region (B). A SiC device is fabricated using the SiC substrate.

First claim

The invention claimed is:

1. A SiC single crystal, comprising:
in a plane substantially parallel to a c-plane,
(a) a region (A) in which a majority of edge dislocations have Burgers vectors pointing in a same direction, and
(b) a region (B) that is different from region (A) and in which a majority of basal plane dislocations have Burgers vectors pointing in a same direction.

2. The SiC single crystal according to claim 1 , further comprising:
a facet portion,
wherein the region (A) is located in a <1-100> direction with respect to the facet portion, and
the region (B) is located in a <11-20> direction with respect to the facet portion.

3. The SiC single crystal according to claim 2 , wherein the facet portion exists at an end of the SiC single crystal, and
one of the region (A) and the region (B) exists in a direction opposite to a direction of the facet portion.

4. The SiC single crystal according to claim 2 , wherein the facet portion exists substantially at a center of the SiC single crystal.

5. A SiC wafer, wherein the SiC wafer is a slice from the SiC single crystal according to claim 3 in a direction substantially parallel to a c-plane of the SiC single crystal,
a sliced plane has an offset direction of a <1-100> direction, and
the region (A) is provided at an end opposite to the facet portion.

6. A SiC wafer, wherein the SiC wafer is a slice from the SiC single crystal according to claim 3 in a direction substantially parallel to a c-plane of the SiC single crystal,
a sliced plane has an offset direction of a <11-20> direction, and
the region (B) is provided at an end opposite to the facet portion.

7. A SiC wafer, wherein the SiC wafer is a slice from the SiC single crystal according to claim 4 in a direction substantially parallel to a c-plane of the SiC single crystal, and
a sliced plane has an offset direction of a <1-100> direction.

8. A SiC wafer, wherein the SiC wafer is a slice from the SiC single crystal according to claim 4 in a direction substantially parallel to a c-plane of the SiC single crystal, and
a sliced plane has an offset direction of a <11-20> direction.

9. The SiC wafer according to claim 5 wherein an orientation flat portion (a deficient portion as a mark of wafer orientation) is provided in a direction of the region (B).

10. A SiC substrate, wherein the SiC substrate is produced by cutting a SiC wafer from the SiC single crystal according to claim 1 in a direction substantially parallel to a c-plane of the SiC single crystal, and
cutting the SiC substrate from the SiC wafer such that the SiC substrate mainly contains one of the region (A) and the region (B).

11. The SiC substrate according to claim 10 , wherein the SiC substrate contains the region (A), and
an offset direction is substantially perpendicular to the Burgers vectors of the majority of edge dislocations in region (A).

12. The SiC substrate according to claim 10 , wherein the SiC substrate contains the region (B), and
an offset direction is substantially perpendicular to the Burgers vectors of the majority of basal plane dislocations in region (B).

13. A SiC device, wherein the SiC device is fabricated using the SiC wafer according to claim 5 .

14. A SiC device, wherein the SiC device is fabricated using the SiC substrate according to claim 10 .

Assignees

• Toyota Chuo Kenkyusho Kk
• Denso Corp
• Showa Denko Kk

Inventors

• Gunjishima Itaru
• Kanzawa Yusuke
• Urakami Yasushi
• Kobayashi Masakazu

Classifications

• C30B23/025

  characterised by the substrate · CPC title

• C30B29/64

  Flat crystals, e.g. plates, strips or discs · CPC title

• H01L29/045

  Electricity · mapped topic

• C30B25/186

  being specially pre-treated by, e.g. chemical or physical means · CPC title

• C30B29/36 Primary

  Carbides · CPC title