# US 10,246,793 B2 · Semiconductor manufacturing method and SiC substrate

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- Number: US 10,246,793 B2
- Document ID: US10246793B2
- Status: Granted
- Kind: B2
- Application number: 15/476,327
- Filed: 2017-03-31
- Published: 2017-07-20
- Granted: 2019-04-02
- Earliest claimed: 2015-04-17
- Assignees: Fuji Electric Co., Ltd.
- Applicants: Fuji Electric Co., Ltd.
- Inventors: Katsunori Suzuki
- Web page: https://patentgrep.com/patent/US10246793B2

## CPC

- C30B 23/025: {characterised by the substrate}
- C30B 25/186: {being specially pre-treated by, e.g. chemical or physical means}
- C30B 29/36: Carbides
- H10D 8/00: Diodes (variable-capacitance diodes H10D1/64; gated diodes H10D12/00)
- H10D 8/045: {of PN junction diodes}
- H10D 8/422: {PN diodes having the PN junctions in mesas}
- H10D 62/106: {having supplementary regions doped oppositely to or in rectifying contact with regions of the semiconductor bodies, e.g. guard rings with PN or Schottky junctions}
- H10D 62/405: {Orientations of crystalline planes}
- H10D 62/8325: {Silicon carbide}
- H10P 14/20: of semiconductor materials
- H10P 14/2904: {Silicon carbide}
- H10P 14/2925: {Surface structures}
- H10P 14/2926: {Crystal orientations}
- H10P 14/3408: {Silicon carbide}
- H10P 14/36: {characterised by treatments done before the formation of the materials}
- H10D 8/051: {of Schottky diodes}
- 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
- H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10

## Abstract

A semiconductor device is provided in which a front surface of an SiC substrate is treated before epitaxial growth so as to reduce crystal defects such as stacking faults. In an aspect, an epitaxial layer is deposited on an SiC substrate in which a periodic texture is formed in a direction perpendicular to a <−1100> direction of the SiC substrate and in which an angle between a basal plane of the SiC substrate and a surface of the formed texture is smaller than an off angle.

## Claims

### Claim 1

A method of manufacturing semiconductor, comprising:
periodically forming textures, each texture being arranged along a direction perpendicular to a <−1100> direction of an SiC substrate, and having a first inclination surface that has an inclination angle ϕ to a front surface of the SiC substrate, wherein an angle between a basal plane of the SiC substrate and the first inclination surface of said each texture is smaller than an off angle θ, and the angle |θ−ϕ| between the basal plane and the first inclination surface of said each texture is 3° or less; and
depositing an epitaxial film on the SiC substrate.

### Claim 2 (depends on 1)

The method according to claim 1, wherein said each texture is formed by bringing a processing tool having a surface coat layer on a front surface of the processing tool into contact with the SiC substrate and reciprocating the processing tool in the <−1100> direction of the SiC substrate.

### Claim 3 (depends on 1)

The method according to claim 1, wherein a pitch in a direction perpendicular to the <−1100> direction of the SiC substrate is 200 nm or less.

### Claim 4 (depends on 1)

The method according to claim 1, wherein said each texture is a line pattern-like texture.

### Claim 5 (depends on 1)

The method according to claim 1, wherein the periodically forming textures includes forming the textures each having the first inclination surface and a second inclination surface, when a valley angle subtended between the first and second inclination surfaces of each said texture is denoted as ψ, the valley angle ψ, satisfies:
ψ=90°+|θ−ϕ|.

### Claim 6 (depends on 2)

The method according to claim 2, wherein the surface coat layer is one of Pt, Ir, Re, Pd, Rh, Os, Au, and Ag.

### Claim 7

An SiC substrate, comprising:
a front surface on which an epitaxial film is deposited; and
textures formed on the front surface, each texture being arranged along a direction perpendicular to a <−1100> direction of the SiC substrate and having a first inclination surface that has an inclination angle ϕ to a front surface of the SiC substrate, wherein an angle between a basal plane of the SiC substrate and the first inclination surface of the formed texture is smaller than an off angle θ, and the angle |θ−ϕ| between the basal plane and said each texture is 3° or less.

### Claim 8 (depends on 7)

The SiC substrate according to claim 7, wherein a pitch of adjacent two textures in the direction perpendicular to the <−1100> direction of the SiC substrate is 200 nm or less.

### Claim 9 (depends on 7)

The SiC substrate according to claim 7, wherein, said each texture has a second inclination surface, and when a valley angle subtended between first and second inclination surfaces of each said texture is denoted as ψ, the valley angle ψ satisfies:
ψ=90°+|θ−ϕ|.

### Claim 10 (depends on 7)

The SiC substrate according to claim 7, wherein said each texture is a line pattern-like texture.