SiC epitaxial wafer and method for producing same, and device for producing SiC epitaxial wafer

Patent metadata

Field	Value
Publication number	US-9768047-B2
Application number	US-201615260152-A
Country	US
Kind code	B2
Filing date	Sep 8, 2016
Priority date	Jul 19, 2011
Publication date	Sep 19, 2017
Grant date	Sep 19, 2017

Abstract

A SiC epitaxial wafer manufacturing method of the present invention includes: manufacturing a SiC epitaxial wafer including a SiC epitaxial layer on a surface of a SiC single crystal wafer while supplying a raw material gas into a chamber using a SiC epitaxial wafer manufacturing apparatus; and manufacturing a subsequent SiC epitaxial wafer after measuring a surface density of triangular defects originating from a material piece of an internal member of the chamber on the SiC epitaxial layer of the previously manufactured SiC epitaxial wafer.

First claim

What is claimed is:

1. A measurement method of a triangular defect, which is present in a SiC epitaxial layer formed on a SiC single crystal substrate in a SiC epitaxial wafer, by using an optical microscope or an optical surface inspection apparatus using a laser beam, comprising
shifting a position of focus in an optical image from a surface of the SiC epitaxial layer toward an interface between the SiC epitaxial layer and the SiC single crystal substrate, to thereby identify a starting point of the triangular defect, wherein
the triangular defect has a material piece of an internal member of a chamber as the starting point and
the triangular defect is a triangle-shaped defect which has the material piece of the internal member of the chamber as an apex and is formed along a step-flow growth direction in which the apex of a triangle and its opposite side (base) are sequentially arranged.

2. The measurement method according to claim 1 , further comprising: analyzing a composition of the triangular defect by using an energy dispersive X-ray spectroscopy.

3. A SiC epitaxial wafer manufacturing method comprising:
manufacturing a SiC epitaxial wafer including a SiC epitaxial layer on a surface of a SiC single crystal wafer while supplying a raw material gas into a chamber by using a SiC epitaxial wafer manufacturing apparatus;
manufacturing a subsequent SiC epitaxial wafer after a measurement of a surface density of a triangular defect, which has a material piece of an internal member of the chamber as a starting point, in the SiC epitaxial layer of the previously manufactured SiC epitaxial wafer; and
replacing the internal member of the chamber according to a result of the measurement of the surface density of the triangular defect, wherein
the measurement of the surface density of the triangular defect comprises shifting a position of focus in an optical image of an optical microscope or an optical surface inspection apparatus using a laser beam from a surface of the SiC epitaxial layer toward an interface between the SiC epitaxial layer and the SiC single crystal substrate, to thereby identify the starting point of the triangular defect.

4. The SiC epitaxial wafer manufacturing method according to claim 3 , wherein
the SiC epitaxial wafer manufacturing apparatus includes: a susceptor that includes a wafer placement unit on which a wafer is placed; a top plate that is disposed to face an upper surface of the susceptor so that a reaction space is formed between the susceptor and the top plate; and a shielding plate that is disposed to be close to a lower surface of the top plate to such an extent that a deposit is prevented from being attached to the lower surface of the top plate, and
the internal member of the chamber to be replaced is the shielding plate.

5. The SiC epitaxial wafer manufacturing method according to claim 3 , wherein
the SiC epitaxial wafer manufacturing apparatus includes: a susceptor that includes a wafer placement unit on which a wafer is placed; and a top plate that is disposed to face an upper surface of the susceptor so that a reaction space is formed between the susceptor and the top plate, and
the internal member of the chamber to be replaced is the top plate.

Assignees

• Showa Denko Kk

Inventors

• KAGESHIMA Yoshiaki
• Muto Daisuke
• Momose Kenji
• Miyasaka Yoshihiko

Classifications

• H10P14/3442

  N-type · CPC title

• H10P14/3408

  Silicon carbide · CPC title

• H10P14/2926

  Crystal orientations · CPC title

• H10P14/2904

  Silicon carbide · CPC title

• H10P14/24

  using chemical vapour deposition [CVD] · CPC title