Method of manufacturing silicon carbide semiconductor device

Patent metadata

Field	Value
Publication number	US-10056247-B2
Application number	US-201515527619-A
Country	US
Kind code	B2
Filing date	Oct 7, 2015
Priority date	Nov 19, 2014
Publication date	Aug 21, 2018
Grant date	Aug 21, 2018

Abstract

In accordance with the following step of a method of manufacturing a MOSFET, a first cutting step of cutting a silicon carbide wafer along a plane substantially parallel to a {11-20} plane is performed. After the first cutting step, a second cutting step of cutting the silicon carbide wafer along a plane substantially perpendicular to the {11-20} plane and substantially perpendicular to the first main surface is performed.

First claim

The invention claimed is:

1. A method of manufacturing a silicon carbide semiconductor device, comprising:
preparing a silicon carbide wafer having a first main surface and a second main surface opposite to the first main surface;
a first cutting step of cutting the silicon carbide wafer along a plane substantially parallel to a {11-20} plane;
after the first cutting step, a second cutting step of cutting the silicon carbide wafer along a plane substantially perpendicular to the {11-20} plane and substantially perpendicular to the first main surface; and
after the preparing a silicon carbide wafer and before the first cutting step, affixing an adhesive tape to one of the first main surface and the second main surface, wherein
the adhesive tape has an adhesive portion in contact with the one of the surfaces, and a base material located opposite to the one of the surfaces as seen from the adhesive portion, and
in each of the first cutting step and the second cutting step, an incision having a depth of not less than 15% and not more than 50% of a thickness of the base material is formed in the base material.

2. The method of manufacturing a silicon carbide semiconductor device according to claim 1 , wherein
the first main surface is a plane angled off by not less than 3° and not more than 5° relative to a {0001} plane toward an off direction, and
in the second cutting step, the silicon carbide wafer is cut substantially toward the off direction.

3. The method of manufacturing a silicon carbide semiconductor device according to claim 1 , wherein
in each of the first cutting step and the second cutting step, a cutting speed of the silicon carbide wafer in a direction parallel to the first main surface is not less than 1 mm/second and not more than 40 mm/second.

4. The method of manufacturing a silicon carbide semiconductor device according to claim 1 , wherein
in each of the first cutting step and the second cutting step, the silicon carbide wafer is cut by a rotating blade, and
a rotational speed of the blade is not less than 5000 rpm and not more than 50000 rpm.

5. The method of manufacturing a silicon carbide semiconductor device according to claim 1 , wherein
in the first cutting step, the entire silicon carbide wafer is cut at a prescribed interval to form a plurality of strip-like pieces as seen along a direction perpendicular to the first main surface, and
in the second cutting step, all of the plurality of pieces are cut at a prescribed interval to form a plurality of chips.

6. The method of manufacturing a silicon carbide semiconductor device according to claim 1 , wherein
the first cutting step and the second cutting step are alternately repeated.

7. A method of manufacturing a silicon carbide semiconductor device, comprising:
preparing a silicon carbide wafer having a first main surface and a second main surface opposite to the first main surface;
after the preparing a silicon carbide wafer, affixing an adhesive tape to the second main surface;
after the affixing an adhesive tape to the second main surface, a first cutting step of cutting the silicon carbide wafer along a plane substantially parallel to a {11-20} plane;
after the first cutting step, a second cutting step of cutting the silicon carbide wafer along a plane substantially perpendicular to the {11-20} plane and substantially perpendicular to the first main surface; and
after the second cutting step, removing the adhesive tape from the silicon carbide wafer,
the adhesive tape having an adhesive portion in contact with the second main surface, and a base material located opposite to the second main surface as seen from the adhesive portion,
in each of the first cutting step and the second cutting step, an incision being formed in the base material.

Assignees

• Sumitomo Electric Industries

Inventors

• Sakai Mitsuhiko
• Kitabayashi Hiroyuki

Classifications

• H10P72/7416

  used during dicing or grinding · CPC title

• H10P72/744

  Details of chemical or physical process used for separating the auxiliary support from a device or a wafer · CPC title

• H10P72/7402

  Wafer tapes, e.g. grinding or dicing support tapes · CPC title

• H10P72/0428

  Apparatus for mechanical treatment or grinding or cutting · CPC title

• H10P54/00 Primary

  Cutting or separating of wafers, substrates or parts of devices · CPC title