# US 2014/0190399 A1 · REDUCTION OF BASAL PLANE DISLOCATIONS IN EPITAXIAL SiC USING AN IN-SITU ETCH PROCESS

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- Number: US 2014/0190399 A1
- Document ID: US20140190399A1
- Status: Published application
- Kind: A1
- Application number: 14/204,045
- Filed: 2014-03-11
- Published: 2014-07-10
- Earliest claimed: 2009-08-20
- Assignees: The Government of the United States of America, as represented by the Secretary of the Navy
- Inventors: Rachael L. Myers-Ward; David Kurt Gaskill; Charles R. Eddy, JR.; Robert E. Stahlbush; Nadeemmullah A. Mahadik; Virginia D. Wheeler
- Web page: https://patentgrep.com/patent/US20140190399A1

## CPC

- H10P 14/3408: {Silicon carbide}
- C30B 25/183: {being provided with a buffer layer, e.g. a lattice matching layer}
- C30B 25/20: the substrate being of the same materials as the epitaxial layer
- C30B 29/36: Carbides
- H10D 62/8325: {Silicon carbide}
- H10P 14/2904: {Silicon carbide}
- H10P 14/2926: {Crystal orientations}
- H10P 14/3208: {Silicon carbide}
- H10P 14/36: {characterised by treatments done before the formation of the materials}
- H10D 8/50: PIN diodes
- H10P 50/242: {of Group IV 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
- H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES

## Abstract

A method of: providing an off-axis silicon carbide substrate, and etching the surface of the substrate with a dry gas, hydrogen, or an inert gas.

## Claims

### Claim 1

A method comprising:
providing an off-axis silicon carbide substrate; and
etching the surface of the substrate with a dry gas, hydrogen, or an inert gas.

### Claim 2 (depends on 1)

The method of claim 1, wherein the substrate is a 4H-SiC substrate.

### Claim 3 (depends on 1)

The method of claim 1, wherein the substrate is a 6H-SiC substrate

### Claim 4 (depends on 1)

The method of claim 1, wherein the substrate is a 0-8° off-axis 4H-SiC substrate.

### Claim 5 (depends on 1)

The method of claim 1, wherein the etching is performed with hydrogen.

### Claim 6 (depends on 1)

The method of claim 1, wherein the etching is performed with silane.

### Claim 7 (depends on 1)

The method of claim 1, wherein the etching is performed with argon.

### Claim 8 (depends on 1)

The method of claim 1, wherein the etching is performed at 1450-1800° C.

### Claim 9 (depends on 1)

The method of claim 1, wherein the etching is performed at 30-500 mbar of the dry gas.

### Claim 10 (depends on 1)

The method of claim 1, wherein the etching is performed for up to 90 minutes.

### Claim 11 (depends on 1)

The method of claim 1, further comprising:
growing a doped buffer layer on the substrate after the etching.

### Claim 12 (depends on 11)

The method of claim 11, wherein the doped buffer layer is doped with N+.

### Claim 13 (depends on 11)

The method of claim 11, wherein the doped buffer layer is doped with P+.

### Claim 14 (depends on 11)

The method of claim 11, wherein the doped buffer layer is about 0.5-30 μm thick.

### Claim 15 (depends on 11)

The method of claim 11, further comprising:
growing an epitaxial silicon carbide layer on the doped buffer layer.