# US 8,541,769 B2 · Formation of a graphene layer on a large substrate

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- Number: US 8,541,769 B2
- Document ID: US8541769B2
- Status: Granted
- Kind: B2
- Application number: 12/942,490
- Filed: 2010-11-09
- Published: 2012-05-10
- Granted: 2013-09-24
- Earliest claimed: 2010-11-09
- Assignees: International Business Machines Corporation
- Applicants: Jack O. Chu; Christos D. Dimitrakopoulos; Marcus O. Freitag; Alfred Grill; Timothy J. McArdle; Robert L. Wisnieff
- Inventors: Jack O. Chu; Christos D. Dimitrakopoulos; Marcus O. Freitag; Alfred Grill; Timothy J. McArdle; Robert L. Wisnieff
- Web page: https://patentgrep.com/patent/US8541769B2

## CPC

- H10P 14/3208: {Silicon carbide}
- H10D 62/82: Heterojunctions
- H10D 62/882: {Graphene}
- H10P 14/20: of semiconductor materials
- H10P 14/24: using chemical vapour deposition [CVD]
- H10P 14/2904: {Silicon carbide}
- H10P 14/2921: {being crystalline insulating materials}
- H10P 14/3406: {Carbon, e.g. diamond-like carbon}
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
- H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES

## Abstract

A single crystalline silicon carbide layer can be grown on a single crystalline sapphire substrate. Subsequently, a graphene layer can be formed by conversion of a surface layer of the single crystalline silicon layer during an anneal at an elevated temperature in an ultrahigh vacuum environment. Alternately, a graphene layer can be deposited on an exposed surface of the single crystalline silicon carbide layer. A graphene layer can also be formed directly on a surface of a sapphire substrate or directly on a surface of a silicon carbide substrate. Still alternately, a graphene layer can be formed on a silicon carbide layer on a semiconductor substrate. The commercial availability of sapphire substrates and semiconductor substrates with a diameter of six inches or more allows formation of a graphene layer on a commercially scalable substrate for low cost manufacturing of devices employing a graphene layer.

## Claims

### Claim 1

A method of forming a graphene layer on a sapphire substrate, said method comprising:
forming a single crystalline semiconductor-carbon alloy layer on a sapphire substrate, wherein a (110) surface of a cubic crystal structure of said single crystalline semiconductor-carbon alloy layer is epitaxially aligned to a (1102) surface of said sapphire substrate; and
forming a graphene layer directly on another (110) surface of said single crystalline semiconductor-carbon alloy layer.

### Claim 2 (depends on 1)

The method of claim 1, wherein said graphene layer is formed by conversion of a top layer of said single crystalline semiconductor-carbon alloy layer.

### Claim 3 (depends on 2)

The method of claim 2, wherein said conversion is effected by evaporating semiconductor atoms from said top layer at an elevated temperature from 800° C. to 2,000° C.

### Claim 4 (depends on 1)

The method of claim 1, wherein said graphene layer is formed by deposition of carbon atoms that form said graphene layer on a top surface of said single crystalline semiconductor-carbon alloy layer.

### Claim 5 (depends on 4)

The method of claim 4, wherein said graphene layer is formed by decomposition of a carbon-containing precursor at said top surface of said single crystalline semiconductor-carbon alloy layer.

### Claim 6 (depends on 1)

The method of claim 1, wherein said single crystalline semiconductor-carbon alloy layer is a single crystalline silicon carbide layer having a hexagonal or cubic crystal structure.