# US 6,284,629 B1 · Method of fabricating an SOI wafer and SOI wafer fabricated by the method

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- Number: US 6,284,629 B1
- Document ID: US6284629B1
- Status: Granted
- Kind: B1
- Application number: 09/343,074
- Filed: 1999-06-29
- Granted: 2001-09-04
- Earliest claimed: 1998-07-07
- Assignees: Shin-Etsu Handotai Co., Ltd.
- Inventors: Isao Yokokawa; Naoto Tate; Kiyoshi Mitani
- Web page: https://patentgrep.com/patent/US6284629B1

## CPC

- H10P 90/1914: {using bonding}
- 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}
- Y10S 156/942: with reorientation means
- Y10S 438/977: Thinning or removal of substrate
- Y10T 156/1978: Delaminating bending means
- 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
- Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

There is disclosed a method of fabricating an SOI wafer wherein an oxide film is formed on at least one of two single crystal silicon wafers; hydrogen ions or rare gas ions are implanted into the upper surface of one of the two silicon wafers in order to form an ion implanted layer; the ion-implanted surface is brought into close contact with the surface of the other silicon wafer via the oxide film; heat treatment is performed to separate a thin film from the silicon wafer with using the ion implanted layer as a delaminating plane to fabricate the SOI wafer having an SOI layer; and then an epitaxial layer is grown on the SOI layer to form a thick SOI layer. There is provided an SOI wafer which has a thick SOI layer with good thickness uniformity and good crystallinity and which is useful for a bipolar device or a power device.

## Claims

### Claim 1

A method of fabricating an SOI wafer wherein an oxide film is formed on at least one of two single crystal silicon wafers; hydrogen ions or rare gas ions are implanted into the upper surface of one of the two silicon wafers in order to form an ion implanted layer; the ion-implanted surface is brought into close contact with the surface of the other silicon wafer via the oxide film; heat treatment is performed to separate a thin film from the silicon wafer with using the ion implanted layer as a delaminating plane to fabricate the SOI wafer having an SOI layer; and then an epitaxial layer is grown on the SOI layer to form a thick SOI.

### Claim 2 (depends on 1)

The method of fabricating an SOI wafer according to claim 1 wherein the SOI wafer before the growth of the epitaxial layer is subjected to a heat treatment in a reducing atmosphere including hydrogen or in an atmosphere including hydrogen chloride gas.

### Claim 3 (depends on 1)

The method of fabricating an SOI wafer according to claim 1 wherein the thickness of the SOI layer of the SOI wafer before growth of the epitaxial layer is 0.2 μm or more.

### Claim 4 (depends on 2)

The method of fabricating an SOI wafer according to claim 2 wherein the thickness of the SOI layer of the SOI wafer before growth of the epitaxial layer is 0.2 μm or more.

### Claim 5 (depends on 1)

The method of fabricating an SOI wafer according to claim 1 wherein the thickness of the thick SOI layer after the epitaxial growth is 2 μm or more.

### Claim 6 (depends on 2)

The method of fabricating an SOI wafer according to claim 2 wherein the thickness of the thick SOI layer after the epitaxial growth is 2 μm or more.

### Claim 7 (depends on 3)

The method of fabricating an SOI wafer according to claim 3 wherein the thickness of the thick SOI layer after the epitaxial growth is 2 μm or more.

### Claim 8 (depends on 1)

A method for reusing a delaminated wafer produced as a by-product in the method according to claim 1 as a silicon wafer after reprocessing it.

### Claim 9 (depends on 2)

A method for reusing a delaminated wafer produced as a by-product in the method according to claim 2 as a silicon wafer after reprocessing it.

### Claim 10 (depends on 3)

A method for reusing a delaminated wafer produced as a by-product in the method according to claim 3 as a silicon wafer after reprocessing it.

### Claim 11 (depends on 5)

A method for reusing a delaminated wafer produced as a by-product in the method according to claim 5 as a silicon wafer after reprocessing it.