# US 10,865,500 B2 · SiC epitaxial wafer and method for manufacturing SiC epitaxial wafer

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- Number: US 10,865,500 B2
- Document ID: US10865500B2
- Status: Granted
- Kind: B2
- Application number: 15/553,248
- Filed: 2016-02-16
- Published: 2018-01-18
- Granted: 2020-12-15
- Earliest claimed: 2015-03-03
- Assignees: Showa Denko K.K.
- Applicants: Showa Denko K.K.
- Inventors: Jun Norimatsu; Akira Miyasaka; Yoshiaki Kageshima; Koji Kamei; Daisuke Muto
- Web page: https://patentgrep.com/patent/US10865500B2

## CPC

- H10P 14/2904: {Silicon carbide}
- C30B 25/165: {the flow of the reactive gases}
- C30B 25/186: {being specially pre-treated by, e.g. chemical or physical means}
- C30B 25/20: the substrate being of the same materials as the epitaxial layer
- C30B 29/36: Carbides
- H10P 14/20: of semiconductor materials
- H10P 14/24: using chemical vapour deposition [CVD]
- H10P 14/29: {characterised by the substrates}
- H10P 14/2926: {Crystal orientations}
- H10P 14/3408: {Silicon carbide}
- H10P 14/36: {characterised by treatments done before the formation of the materials}
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
- C30B: SINGLE-CRYSTAL GROWTH (by using ultra-high pressure, e.g. for the formation of diamonds, B01J3/06); UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL (zone-refining of metals or alloys C22B); PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE (casting of metals, casting of other substances by the same processes or devices B22D; working of plastics B29; modifying the physical structure of metals or alloys C21D, C22F); SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE (for producing semiconductor devices or parts thereof H10); APPARATUS THEREFOR

## Abstract

A SiC epitaxial wafer having a SiC epitaxial layer formed on a SiC single crystal substrate having an offset angle of 4 degrees or less in a<11-20>direction from a (0001) plane. A trapezoidal defect included in the SiC epitaxial wafer includes an inverted trapezoidal defect in which a length of a lower base on a downstream side of a step flow is equal to or less than a length of an upper base on an upstream side of the step flow. Also disclosed is a method for manufacturing the SiC epitaxial wafer.

## Claims

### Claim 1

A SiC epitaxial wafer comprising a SiC epitaxial layer formed on a SiC single crystal substrate having an offset angle of 4 degrees or less in a<11-20>direction from a (0001) plane,
wherein a trapezoidal defect included in the SiC epitaxial wafer comprises an inverted trapezoidal defect in which a length of a lower base on a downstream side of a step flow is equal to or less than a length of an upper base on an upstream side of the step flow,
wherein the trapezoidal defect is on the surface of the epitaxial layer and the upper base of the trapezoidal defect is a lined shape.

### Claim 2 (depends on 1)

The SiC epitaxial wafer according to claim 1, wherein a ratio of the inverted trapezoidal defect in the trapezoidal defect is 50% or more.

### Claim 3 (depends on 1)

The SiC epitaxial wafer according to claim 1, wherein the length of the lower base on the downstream side of the step flow of the inverted trapezoidal defect is 0 and the inverted trapezoidal defect becomes a triangular shape.

### Claim 4

A SiC epitaxial wafer comprising a SiC epitaxial layer formed on a SiC single crystal substrate having an offset angle of 4 degrees or less in a<11-20>direction from a (0001) plane,
wherein a trapezoidal defect included in the SiC epitaxial wafer comprises an inverted trapezoidal defect in which a length of a lower base on a downstream side of a step flow is equal to or less than a length of an upper base on an upstream side of the step flow,
wherein the trapezoidal defect is on the surface of the epitaxial layer and the upper base of the trapezoidal defect is a lined shape, and
wherein a ratio of the inverted trapezoidal defect in the trapezoidal defect is 75% or more.