Method for manufacturing SiC substrate

Patent metadata

Field	Value
Publication number	US-10559508-B2
Application number	US-201816208772-A
Country	US
Kind code	B2
Filing date	Dec 4, 2018
Priority date	May 21, 2018
Publication date	Feb 11, 2020
Grant date	Feb 11, 2020

Abstract

A method for manufacturing an SiC substrate includes: performing a CMP treatment on an SiC substrate; after the CMP treatment, capturing an image of a surface of the SiC substrate to detect a scratch; determining the SiC substrate as a good article when a length L of the scratch having a contrast value equal to or larger than a threshold value is not more than π(D/2)2/A×F/100, wherein the scratch having the contrast value equal to or larger than the threshold value in the image serves as a starting point of an epitaxial defect, a diameter of the SiC substrate is represented by D, a length of a long side of a device chip to be formed on the SiC substrate is represented by A, and an allowable defective rate caused by scratches is represented by F.

First claim

The invention claimed is:

1. A method for manufacturing an SiC substrate comprising:
performing a CMP treatment on an SiC substrate;
after the CMP treatment, capturing an image of a surface of the SiC substrate to detect a scratch;
determining the SiC substrate as a good article when a length L of the scratch having a contrast value equal to or larger than a threshold value is not more than π(D/2) 2 /A×F/100,
wherein the scratch having the contrast value equal to or larger than the threshold value in the image serves as a starting point of an epitaxial defect,
a diameter of the SiC substrate is represented by D,
a length of a long side of a device chip to be formed on the SiC substrate is represented by A, and
an allowable defective rate caused by scratches is represented by F.

2. The method for manufacturing an SiC substrate according to claim 1 , wherein the CMP treatment and the scratch detection are repeated until the SiC substrate is determined as a good article.

3. The method for manufacturing an SiC substrate according to claim 1 , further comprising epitaxially growing an SiC film on the SiC substrate determined as a good article.

4. The method for manufacturing an SiC substrate according to claim 2 , further comprising epitaxially growing an SiC film on the SiC substrate determined as a good article.

Assignees

• Mitsubishi Electric Corp

Inventors

• Kimura Yasuhiro

Classifications

• H10P74/203 Primary

  Structural properties, e.g. testing or measuring thicknesses, line widths, warpage, bond strengths or physical defects · CPC title

• H10P52/402

  of semiconductor materials · CPC title

• H10P14/2904

  Silicon carbide · CPC title

• H10P74/238 Primary

  comprising acting in response to an ongoing measurement without interruption of processing, e.g. endpoint detection or in-situ thickness measurement · CPC title

• H01L21/02378

  Electricity · mapped topic