# US 10,312,330 B2 · Method for fabricating semiconductor substrate, semiconductor substrate, and semiconductor device

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- Number: US 10,312,330 B2
- Document ID: US10312330B2
- Status: Granted
- Kind: B2
- Application number: 15/905,984
- Filed: 2018-02-27
- Published: 2018-07-05
- Granted: 2019-06-04
- Earliest claimed: 2014-03-19
- Assignees: Kabushiki Kaisha Toshiba
- Applicants: Kabushiki Kaisha Toshiba
- Inventors: Johji Nishio; Ryosuke Iijima; Kazuto Takao; Takashi Shinohe
- Web page: https://patentgrep.com/patent/US10312330B2

## CPC

- H10D 62/8325: {Silicon carbide}
- H10D 8/045: {of PN junction diodes}
- H10D 8/051: {of Schottky diodes}
- H10D 8/422: {PN diodes having the PN junctions in mesas}
- H10D 12/031: {of IGBTs}
- H10D 62/53: the imperfections being within the semiconductor body
- H10P 14/24: using chemical vapour deposition [CVD]
- H10P 14/2904: {Silicon carbide}
- H10P 14/2926: {Crystal orientations}
- H10P 14/3208: {Silicon carbide}
- H10P 14/3408: {Silicon carbide}
- H10P 14/3442: {N-type}
- H10P 14/36: {characterised by treatments done before the formation of the materials}
- H10P 30/204: {into Group IV semiconductors}
- H10P 30/208: {of electrically inactive species}
- H10D 12/032: {of vertical IGBTs}
- H10D 12/441: {Vertical IGBTs}
- H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10

## Abstract

In a method for fabricating a semiconductor substrate according to an embodiment, an SiC substrate is formed by vapor growth and C (carbon) is introduced into the surface of the SiC substrate to form an n-type SiC layer on the SiC substrate by an epitaxial growth method.

## Claims

### Claim 1

A semiconductor device comprising:
an SiC substrate having a first region and a second region, the first region provided on a first part of an SiC substrate surface, the second region provided on a second part of the SiC substrate surface, a Z1/2 level density measured by DLTS (Deep Level Transient Spectroscopy) in the first region being 1×1011 cm−3 or less, a Z1/2 level density measured by DLTS in the second region being more than 1×1011 cm−3; and
an n-type SiC layer provided on the SiC substrate, the n-type SiC layer having an impurity concentration of an n-type impurity lower than an impurity concentration of the n-type impurity or a p-type impurity of the SiC substrate,
wherein the first region and the second region are in direct contact with the SiC layer, and
wherein the impurity concentration of the n-type or p-type impurity in the SiC substrate is 5×1018 cm−3 or more.

### Claim 2 (depends on 1)

The device according to claim 1, wherein a thickness of the n-type SiC layer is 50 μm or more.

### Claim 3 (depends on 1)

The device according to claim 1, wherein the first region is selectively provided on a side of the SiC substrate of an interface between the SiC substrate and the n-type SiC layer.