# US 2019/0355629 A1 · METHOD FOR MANUFACTURING SiC SUBSTRATE

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- Number: US 2019/0355629 A1
- Document ID: US20190355629A1
- Status: Published application
- Kind: A1
- Application number: 16/208,772
- Filed: 2018-12-04
- Published: 2019-11-21
- Earliest claimed: 2018-05-21
- Assignees: Mitsubishi Electric Corporation
- Applicants: Mitsubishi Electric Corporation
- Inventors: Yasuhiro Kimura
- Web page: https://patentgrep.com/patent/US20190355629A1

## CPC

- H10P 74/238: {comprising acting in response to an ongoing measurement without interruption of processing, e.g. endpoint detection or in-situ thickness measurement}
- H10D 62/8325: {Silicon carbide}
- H10P 14/2904: {Silicon carbide}
- H10P 52/402: {of semiconductor materials}
- H10P 74/203: {Structural properties, e.g. testing or measuring thicknesses, line widths, warpage, bond strengths or physical defects}
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
- H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES

## 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.

## Claims

### Claim 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.

### Claim 2 (depends on 1)

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.

### Claim 3 (depends on 1)

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.

### Claim 4 (depends on 2)

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.