# US 10,312,133 B2 · Method of manufacturing silicon on insulator substrate

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- Number: US 10,312,133 B2
- Document ID: US10312133B2
- Status: Granted
- Kind: B2
- Application number: 15/459,404
- Filed: 2017-03-15
- Published: 2017-09-28
- Granted: 2019-06-04
- Earliest claimed: 2016-03-23
- Assignees: Toyota Jidosha Kabushiki Kaisha; Sumco Corporation
- Applicants: Toyota Jidosha Kabushiki Kaisha; Sumco Corporation
- Inventors: Tetsuya Yamada; Hiromichi Kinpara; Shinjirou Uchida; Masamitsu Fukuda
- Web page: https://patentgrep.com/patent/US10312133B2

## CPC

- H10P 90/1908: {using silicon implanted buried insulating layers, e.g. oxide layers [SIMOX]}
- H10P 30/209: {in silicon to make buried insulating layers}
- H10P 30/22: using masks
- H10P 90/1906: {Preparing SOI wafers}
- H10P 95/90: Thermal treatments, e.g. annealing or sintering
- H10W 10/031: {of isolation regions comprising PN junctions}
- H10W 10/181: {Semiconductor-on-insulator [SOI] isolation regions, e.g. buried oxide regions of SOI wafers}
- H10W 10/30: Isolation regions comprising PN junctions
- 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

A method of manufacturing a silicon on insulator substrate includes: preparing a semiconductor substrate including a rear side semiconductor layer, an insulating layer, and a front side semiconductor layer, a first surface of the insulating layer being in contact with a surface of the rear side semiconductor layer, and a first surface of the front side semiconductor layer being in contact with a second surface of the insulating layer; forming a high concentration region in which an impurity concentration is increased in the front side semiconductor layer, by injecting impurities into the front side semiconductor layer; heating the semiconductor substrate having the high concentration region; and epitaxially growing an additional semiconductor layer on a second surface of the front side semiconductor layer of the heated semiconductor substrate, the additional semiconductor layer having a lower impurity concentration than the high concentration region.

## Claims

### Claim 1

A method of manufacturing a silicon on insulator substrate, comprising:
(a) preparing a semiconductor substrate including a rear side semiconductor layer, an insulating layer, and a front side semiconductor layer, a first surface of the insulating layer being in contact with a surface of the rear side semiconductor layer, and a first surface of the front side semiconductor layer being in contact with a second surface of the insulating layer;
(b) forming a high concentration region in the front side semiconductor layer, including a plurality of regions arranged in a lateral direction of the front side semiconductor layer, in which an impurity concentration is increased, by repeatedly injecting impurities into the front side semiconductor layer while changing an area of the front side semiconductor layer into which the impurities are injected, one of the plurality of regions having a different impurity concentration than another of the plurality of regions, and the impurities being n-type impurities or p-type impurities;
(c) heating the semiconductor substrate having the high concentration region; and
(d) epitaxially growing an additional semiconductor layer on a second surface of the front side semiconductor layer of the heated semiconductor substrate, the additional semiconductor layer having a lower impurity concentration than the high concentration region;
wherein, in step (c), an average diffusion length of impurities in the front side semiconductor layer is twice a thickness of the front side semiconductor layer or more.

### Claim 2 (depends on 1)

The manufacturing method according to claim 1, wherein step (d) includes forming the additional semiconductor layer including a laminate of a plurality of epitaxial layers by repeating epitaxial growing an epitaxial layer and injection of impurities into the epitaxial layer.

### Claim 3 (depends on 1)

The manufacturing method according to claim 1, wherein
a thickness of the additional semiconductor layer is greater than a thickness of the front side semiconductor layer.

### Claim 4 (depends on 1)

The manufacturing method according to claim 1, further comprising
(e) forming a concave portion in the second surface of the front side semiconductor layer before step (b).

### Claim 5 (depends on 1)

The manufacturing method according to claim 1, wherein step (b) includes:
forming a resist mask having an opening on the second surface of the front side semiconductor layer; and
injecting impurities into the front side semiconductor layer through the opening.

### Claim 6 (depends on 5)

The manufacturing method according to claim 5, wherein
step (b) includes forming an oxide film on the second surface of the front side semiconductor layer before the resist mask is formed,
the resist mask is formed on the oxide film, and
the impurities are injected into the front side semiconductor layer through the oxide film.

### Claim 7

A method of manufacturing a silicon on insulator substrate, comprising:
(a) preparing a semiconductor substrate including a rear side semiconductor layer, an insulating layer, and a front side semiconductor layer, a first surface of the insulating layer being in contact with a surface of the rear side semiconductor layer, and a first surface of the front side semiconductor layer being in contact with a second surface of the insulating layer;
(b) forming a high concentration region in the front side semiconductor layer, including a plurality of regions arranged in a lateral direction of the front side semiconductor layer, in which an impurity concentration is increased, by repeatedly injecting impurities into the front side semiconductor layer while changing an area of the front side semiconductor layer into which the impurities are injected, one of the plurality of regions having a different impurity concentration than another of the plurality of regions, and the impurities being n-type impurities or p-type impurities;
(c) heating the semiconductor substrate having the high concentration region; and
(d) epitaxially growing an additional semiconductor layer on a second surface of the front side semiconductor layer of the heated semiconductor substrate, the additional semiconductor layer having a lower impurity concentration than the high concentration region.