Dislocation in SiC semiconductor substrate

Patent metadata

Field	Value
Publication number	US-9450054-B2
Application number	US-201414535642-A
Country	US
Kind code	B2
Filing date	Nov 7, 2014
Priority date	Dec 22, 2011
Publication date	Sep 20, 2016
Grant date	Sep 20, 2016

Abstract

A semiconductor substrate has a main surface and formed of single crystal silicon carbide. The main surface includes a central area, which is an area other than the area within 5 mm from the outer circumference. When the central area is divided into square areas of 1 mm×1 mm, in any square area, density of dislocations of which Burgers vector is parallel to <0001> direction is at most 1×10 5 cm −2 . Thus, a silicon carbide semiconductor substrate enabling improved yield of semiconductor devices can be provided.

First claim

What is claimed is:

1. A semiconductor substrate having a main surface, formed of single crystal silicon carbide, said main surface comprising:
an outer circumferential area within 5 mm from an outer circumference; and
a central area as an area other than the outer circumferential area, wherein
when said central area is divided into square areas of 1 mm × 1 mm, in any said square area, density of dislocations of which Burgers vector is parallel to <0001> direction is at most 1 × 10 4 cm −2 , wherein
in said central area, density of dislocations of which Burgers vector is parallel to the <0001> direction is lower than density of dislocations of which Burgers vector includes components in the <0001> direction and <11-20> direction.

2. The semiconductor substrate according to claim 1 , including a dislocation branched to a plurality of dislocation lines inside said semiconductor substrate and of which Burgers vector is parallel to the <0001> direction.

3. The semiconductor substrate according to claim 1 , of which diameter is at least 4 inches.

4. The semiconductor substrate according to claim 1 , wherein the single crystal silicon carbide forming said semiconductor substrate has polytype of 4H.

5. A semiconductor substrate having a main surface, formed of single crystal silicon carbide, said main surface comprising:
an outer circumferential area within 5 mm from an outer circumference; and
a central area as an area other than the outer circumferential area, wherein
when said central area is divided into square areas of 1 mm×1 mm, in any said square area, density of dislocations of which Burgers vector is parallel to <11-20> direction, with dislocation line existing in the basal plane and the dislocation line exposed at the main surface of the semiconductor substrate, is at most 1×10 4 cm −2 , wherein
in said central area, density of dislocations of which Burgers vector is parallel to the <11-20> direction is lower than density of dislocations of which Burgers vector includes components in the <0001> direction and the <11-20> direction.

6. The semiconductor substrate according to claim 5 , including a dislocation branched to a plurality of dislocation lines inside said semiconductor substrate and having Burgers vector parallel to the <11-20> direction.

7. The semiconductor substrate according to claim 5 , of which diameter is at least 4 inches.

8. The semiconductor substrate according to claim 5 , wherein the single crystal silicon carbide forming said semiconductor substrate has polytype of 4H.

9. A semiconductor substrate having a main surface, formed of single crystal silicon carbide, said main surface comprising:
an outer circumferential area within 5 mm from an outer circumference; and
a central area as an area other than the outer circumferential area, wherein
when said central area is divided into square areas of 1 mm×1 mm, in any said square area, density of dislocations of which Burgers vector includes components parallel to <0001> direction and <11-20> direction is at most 1×10 4 cm −2 .

10. The semiconductor substrate according to claim 9 , wherein
in said central area, density of dislocations of which Burgers vector is parallel to the <0001> direction is lower than density of dislocations of which Burgers vector includes components in the <0001> direction and the <11-20> direction.

11. The semiconductor substrate according to claim 9 , wherein
in said central area, density of dislocations of which Burgers vector is parallel to the <11-20> direction is lower than density of dislocations of which Burgers vector includes components in the <0001> direction and the <11-20> direction.

12. The semiconductor substrate according to claim 9 , including a dislocation branched to a plurality of dislocation lines inside said semiconductor substrate and having Burgers vector including components in the <0001> direction and the <11-20> direction.

13. The semiconductor substrate according to claim 9 , of which diameter is at least 4 inches.

14. The semiconductor substrate according to claim 9 , wherein the single crystal silicon carbide forming said semiconductor substrate has polytype of 4H.

Assignees

• Sumitomo Electric Industries

Inventors

• Nishiguchi Taro
• Harada Shin
• Fujiwara Shinsuke

Classifications

• H10D12/032

  of vertical IGBTs · CPC title

• H10D30/0291

  of vertical DMOS [VDMOS] FETs · CPC title

• H10D30/66 Primary

  Vertical DMOS [VDMOS] FETs · CPC title

• H10D62/8325

  Silicon carbide · CPC title

• H10D62/405

  Orientations of crystalline planes · CPC title