# US 10,612,157 B2 · Method for manufacturing SiC composite substrate, and method for manufacturing semiconductor substrate

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- Number: US 10,612,157 B2
- Document ID: US10612157B2
- Status: Granted
- Kind: B2
- Application number: 15/757,879
- Filed: 2016-09-07
- Published: 2018-11-22
- Granted: 2020-04-07
- Earliest claimed: 2015-09-11
- Assignees: Shin-Etsu Chemical Co., Ltd.; Cusic Inc.
- Applicants: Shin-Etsu Chemical Co., Ltd.; CUSIC Inc.
- Inventors: Yoshihiro Kubota; Shoji Akiyama; Hiroyuki Nagasawa
- Web page: https://patentgrep.com/patent/US10612157B2

## CPC

- C30B 25/20: the substrate being of the same materials as the epitaxial layer
- C30B 25/186: {being specially pre-treated by, e.g. chemical or physical means}
- C30B 29/36: Carbides
- C30B 29/68: Crystals with laminate structure, e.g. "superlattices"
- H10P 14/22: using physical deposition, e.g. vacuum deposition or sputtering
- H10P 14/24: using chemical vapour deposition [CVD]
- H10P 14/3208: {Silicon carbide}
- H10P 14/3238: {being insulating materials}
- H10P 14/3248: {consisting of two layers}
- H10P 14/3408: {Silicon carbide}
- H10P 14/36: {characterised by treatments done before the formation of the materials}
- H10P 52/00: Grinding, lapping or polishing of wafers, substrates or parts of devices
- H10P 90/00: Preparation of wafers not covered by a single main group of this subclass, e.g. wafer reinforcement
- H10P 90/1904: {Preparing vertically inhomogeneous wafers}
- H10P 90/1916: {with separation or delamination along an ion implanted layer, e.g. Smart-cut}
- H10P 95/11: {Separation of active layers from substrates}
- H10W 10/181: {Semiconductor-on-insulator [SOI] isolation regions, e.g. buried oxide regions of SOI wafers}
- H10P 14/20: of semiconductor materials
- H10P 14/2905: {Silicon, silicon germanium or germanium}
- H10P 14/3456: {Polycrystalline}
- 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
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
- H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10

## Abstract

Provided is a method for manufacturing an SiC composite substrate 10 having a single-crystal SiC layer 12 on a polycrystalline SiC substrate 11, wherein: the single-crystal SiC layer 12 is provided on one surface of a holding substrate 21 comprising Si, and a single-crystal SiC-layer carrier 14 is prepared; polycrystalline SiC is then accumulated on the single-crystal SiC layer 12 by a physical or chemical means, and an SiC laminate 15 is prepared in which the single-crystal SiC layer 12 and the polycrystalline SiC substrate 11 are laminated on the holding substrate 21; and the holding substrate 21 is then physically and/or chemically removed. With the present invention, an SiC composite substrate having a single-crystal. SiC layer with good crystallinity is obtained with a simple manufacturing process.

## Claims

### Claim 1

A method for manufacturing an SiC composite substrate having a single-crystal SiC layer on a polycrystalline SiC substrate, comprising:
providing a single-crystal SiC layer on one surface of a holding substrate made of Si to prepare a single-crystal SiC layer carrier, thereafter
(i) causing warp in the single-crystal SiC layer carrier by applying physical damage to a surface opposite to the single-crystal SiC layer-carrying surface of the holding substrate in the single-crystal SiC layer carrier, and then depositing polycrystalline SiC on the single-crystal SiC layer by a physical or chemical means to prepare an SiC laminate in which the single-crystal SiC layer and the polycrystalline SiC substrate are laminated on the holding substrate, or
(ii) depositing polycrystalline SiC on the single-crystal SiC layer by physical or chemical means to prepare an SiC laminate in which the single-crystal SiC layer and the polycrystalline SiC substrate are laminated on the holding substrate, and then applying physical damage to a surface opposite to a surface of the polycrystalline SiC substrate abutting with the single-crystal SiC layer in the SiC laminate to prepare an SiC laminate in which the single-crystal SiC layer and the polycrystalline SiC substrate are laminated on the holding substrate,
and thereafter
removing the holding substrate physically and/or chemically.

### Claim 2 (depends on 1)

The method for manufacturing an SiC composite substrate according to claim 1, wherein the physical damage is applied by at least one processing method selected from sandblasting, grinding, cutting, laser processing and electric discharge machining.

### Claim 3 (depends on 1)

The method for manufacturing an SiC composite substrate according to claim 1, wherein the single-crystal SiC layer is provided on the one surface of the holding substrate with an intermediate layer made of silicon oxide, silicon nitride or silicon oxynitride interposed therebetween.

### Claim 4 (depends on 1)

The method for manufacturing an SiC composite substrate according to claim 1, wherein a single-crystal SiC thin film peeled from a single-crystal SiC substrate by an ion implantation peeling method is transferred onto the holding substrate to provide the single-crystal SiC layer.

### Claim 5 (depends on 1)

The method for manufacturing an SiC composite substrate according to claim 1, wherein the polycrystalline SiC is deposited on the single-crystal SiC layer by chemical vapor deposition.

### Claim 6 (depends on 1)

A method for manufacturing a semiconductor substrate, comprising: manufacturing an SiC composite substrate by the method for manufacturing an SiC composite substrate according to claim 1, and by using the SiC composite substrate as a template, growing SiC single crystal on the single-crystal SiC layer heteroepitaxially to laminate single-crystal SiC.

### Claim 7 (depends on 1)

The method for manufacturing an SiC composite substrate according to claim 1, wherein the step (i) further comprises after depositing the polycrystalline SiC on the single-crystal SiC layer, applying physical damage to a surface opposite to a surface of the polycrystalline SiC substrate abutting with the single-crystal SiC layer in the SiC laminate.

### Claim 8 (depends on 1)

The method for manufacturing an SiC composite substrate according to claim 1, wherein the amount of the physical damage is adjusted so as to cancel out the internal stress of the deposited polycrystalline SiC substrate and the degree of the warp of the SiC laminate.

### Claim 9 (depends on 1)

The method for manufacturing an SiC composite substrate according to claim 1, wherein the physical damage is applied by sandblasting, laser processing or electric discharge machining.