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1. (WO2017169085) SILICON CARBIDE SEMICONDUCTOR DEVICE

Pub. No.:    WO/2017/169085    International Application No.:    PCT/JP2017/003712
Publication Date: Fri Oct 06 01:59:59 CEST 2017 International Filing Date: Fri Feb 03 00:59:59 CET 2017
IPC: H01L 29/78
H01L 29/12
H01L 29/739
Applicants: SUMITOMO ELECTRIC INDUSTRIES, LTD.
住友電気工業株式会社
Inventors: HIYOSHI, Toru
日吉 透
Title: SILICON CARBIDE SEMICONDUCTOR DEVICE
Abstract:
This silicon carbide semiconductor device is provided with: a silicon carbide substrate; a first silicon carbide layer which is arranged on the silicon carbide substrate and has a first conductivity type; a second silicon carbide layer which is arranged on the first silicon carbide layer and has the first conductivity type; a third silicon carbide layer which is arranged on the second silicon carbide layer and has a second conductivity type that is different from the first conductivity type; a fourth silicon carbide layer which is arranged on the third silicon carbide layer and has the first conductivity type; and a first impurity region which is formed so as to penetrate the second silicon carbide layer, the third silicon carbide layer and the fourth silicon carbide layer, and which has the second conductivity type. This silicon carbide semiconductor device is provided with a trench which penetrates the fourth silicon carbide layer and the third silicon carbide layer and reaches the second silicon carbide layer. This silicon carbide semiconductor device is also provided with: a gate insulating film which is in contact with a wall of the trench; a gate electrode which is in contact with the gate insulating film and fills the trench; a second impurity region which is arranged below the trench at a distance from the bottom of the trench, and which has the second conductivity type; a third impurity region which is formed below the first impurity region so as to be in contact with the first impurity region and has the second conductivity type, and which is electrically connected to the second impurity region; and a fourth impurity region which is formed between the second impurity region and the third impurity region and has the first conductivity type.