# US 11,208,719 B2 · SiC composite substrate and method for manufacturing same

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 11,208,719 B2
- Document ID: US11208719B2
- Status: Granted
- Kind: B2
- Application number: 16/743,476
- Filed: 2020-01-15
- Published: 2020-05-14
- Granted: 2021-12-28
- Earliest claimed: 2015-09-14
- 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/US11208719B2

## CPC

- C23C 16/325: {Silicon carbide}
- C23C 16/01: on temporary substrates, e.g. substrates subsequently removed by etching
- C23C 16/42: Silicides
- C30B 25/18: characterised by the substrate
- C30B 29/36: Carbides
- C30B 33/06: Joining of crystals
- H10D 62/10: Shapes, relative sizes or dispositions of the regions of the semiconductor bodies; Shapes of the semiconductor bodies
- H10D 62/8325: {Silicon carbide}
- H10P 10/12: {Bonding of semiconductor wafers or semiconductor substrates to semiconductor wafers or semiconductor substrates (preparing SOI wafers using bonding H10P90/1914)}
- H10P 14/20: of semiconductor materials
- H10P 14/24: using chemical vapour deposition [CVD]
- H10P 14/2904: {Silicon carbide}
- H10P 14/3208: {Silicon carbide}
- H10P 14/3256: {Microstructure}
- H10P 14/3408: {Silicon carbide}
- H10P 14/3456: {Polycrystalline}
- H10P 14/3458: {Monocrystalline}
- H10P 14/36: {characterised by treatments done before the formation of the materials}
- H10P 30/20: into semiconductor materials, e.g. for doping
- 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}
- H10W 10/181: {Semiconductor-on-insulator [SOI] isolation regions, e.g. buried oxide regions of SOI wafers}
- C23C: COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL (making metal-coated products by extrusion B21C23/22; covering with metal by connecting pre-existing layers to articles, see the relevant places, e.g. B21D39/00, B23K; metallising of glass C03C; metallising mortars, concrete, artificial stone, ceramics or natural stone C04B41/00; enamelling of, or applying a vitreous layer to, metals C23D; treating metal surfaces or coating of metals by electrolysis or electrophoresis C25D; single-crystal film growth C30B; by metallising textiles D06M11/83; decorating textiles by locally metallising D06Q1/04)
- 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
- H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10

## Abstract

Provided is an SiC composite substrate 10 having a monocrystalline SiC layer 12 on a polycrystalline SiC substrate 11, wherein: some or all of the interface at which the polycrystalline SiC substrate 11 and the monocrystalline SiC layer 12 are in contact is an unmatched interface I12/11 that is not lattice-matched; the monocrystalline SiC layer 12 has a smooth obverse surface and has, on the side of the interface with the polycrystalline SiC substrate 11, a surface that has more pronounced depressions and projections than the obverse surface; and the close-packed plane (lattice plane 11p) of the crystals of the polycrystalline SiC in the polycrystalline SiC substrate 11 is randomly oriented with reference to the direction of a normal to the obverse surface of the monocrystalline SiC layer 12. The present invention improves the adhesion between the polycrystalline SiC substrate and the monocrystalline SiC layer.

## Claims

### Claim 1

An SiC composite substrate comprising a polycrystalline SiC substrate and a monocrystalline SiC layer thereon, wherein the entirety or a part of the interface of the polycrystalline SiC substrate in abutment with the monocrystalline SiC layer is a mismatch interface that is not lattice-matched, the monocrystalline SiC layer has a smooth front surface and a surface on the side of the interface with the polycrystalline SiC substrate that is more rugged than the front surface, said rugged surface of the monocrystalline SiC layer is composed of oblique surface segments randomly oriented with reference to a direction normal to the front surface of the monocrystalline SiC layer, and the close-packed planes of polycrystalline SiC crystals in the polycrystalline SiC substrate are parallel to said oblique surface segments and correspondingly randomly oriented with reference to a direction normal to the front surface of the monocrystalline SiC layer.

### Claim 2 (depends on 1)

The SiC composite substrate of claim 1 wherein, where the close-packed plane of the crystal lattice of each crystal grain in the polycrystalline SiC substrate is oriented at a deflection angle θ relative to the front surface of the monocrystalline SiC layer, the proportion of crystal grains satisfying θ≤−2° or 2°≤θ among all the crystal grains of the polycrystalline SiC substrate is at least 32%.

### Claim 3 (depends on 2)

The SiC composite substrate of claim 2 wherein said proportion of crystal grains satisfying θ≤−2° or 2°≤θ is at least 50%.

### Claim 4 (depends on 1)

The SiC composite substrate of claim 1 wherein the polycrystalline SiC substrate has a thickness of 100 μm to 650 μm.

### Claim 5 (depends on 1)

The SiC composite substrate of claim 1 wherein the monocrystalline SiC layer has a thickness of 100 nm to 1 μm.

### Claim 6 (depends on 1)

The SiC composite substrate of claim 1 wherein the close-packed plane of the crystal lattice of the monocrystalline SiC layer has a deflection angle of from more than 0° to 10° at its interface with the polycrystalline SiC substrate.

### Claim 7 (depends on 1)

The SiC composite substrate of claim 1 wherein the polycrystalline SiC in the polycrystalline SiC substrate is in the form of cubic crystals in which the close-packed plane is the {1 1 1} plane.