Semiconductor device and method of manufacturing semiconductor device

Patent metadata

Field	Value
Publication number	US-11476326-B2
Application number	US-201917423966-A
Country	US
Kind code	B2
Filing date	Jan 21, 2019
Priority date	Jan 21, 2019
Publication date	Oct 18, 2022
Grant date	Oct 18, 2022

Abstract

A semiconductor device includes a semiconductor base body, and a first main electrode and a second main electrode provided on the semiconductor base body. The semiconductor base body includes a drift region of a first conductivity type through which a main current flows, a column region of a second conductivity type arranged adjacent to the drift region in parallel to a current passage of the main current, a second electrode-connection region of the first conductivity type electrically connected to the second main electrode, and a low-density electric-field relaxation region of the first conductivity type having a lower impurity concentration than the drift region and arranged between the second electrode-connection region and the column region.

First claim

The invention claimed is:

1. A semiconductor device comprising:
a semiconductor base body; and
a first main electrode and a second main electrode provided on the semiconductor base body to serve as both ends of a current passage of a main current flowing in an ON state,
the semiconductor base body including:
a drift region of a first conductivity type through which the main current flows;
a column region of a second conductivity type arranged adjacent to the drift region in parallel to the current passage of the main current;
a second electrode-connection region of the first conductivity type electrically connected to the second main electrode and connected to the drift region;
a low-density electric-field relaxation region of the first conductivity type having a lower impurity concentration than the drift region, and arranged between the second electrode-connection region and the column region, the low-density electric-field relaxation region extending parallel to the drift region along the current passage of the main current; and

a high-density electric-field relaxation region having a higher impurity concentration than the low-density electric-field relaxation region, and arranged on the low-density electric-field relaxation region to be stacked together in a direction perpendicular to an extending direction of the column region so as to be in contact with an edge of the main surface of the column region in contact with the drift region.

2. The semiconductor device according to claim 1 , wherein an edge of an opposed main surface of the column region opposed to another main surface in contact with the drift region is in contact with the low-density electric-field relaxation region.

3. The semiconductor device according to claim 1 , wherein a part of the high-density electric-field relaxation region is provided between the drift region and the second electrode-connection region.

4. The semiconductor device according to claim 1 , further comprising a plurality of the drift regions and a plurality of the column regions, the structure having a super junction structure in which the plural drift regions and the plural column regions are alternately arranged in a direction perpendicular to the current passage of the main current.

5. The semiconductor device according to claim 1 , wherein the first main electrode and the second main electrode are arranged on a common main surface of a single substrate.

6. The semiconductor device according to claim 1 , wherein the first main electrode is provided on a first main surface of the semiconductor base body, and the second main electrode is provided on a second main surface of the semiconductor base body opposed to the first main surface.

7. The semiconductor device according to claim 1 , further comprising a plurality of the drift regions and a plurality of the column regions alternately stacked in a film thickness direction of the semiconductor base body.

8. The semiconductor device according to claim 1 , further comprising:
a first electrode-connection region of the second conductivity type deposited on the semiconductor base body between the first main electrode and the drift region; and
a control electrode provided to be opposed to the first electrode-connection region on the current passage of the main current,
the semiconductor device being configured to serve as a transistor for causing the control electrode to control the main current.

9. The semiconductor device according to claim 1 , wherein the semiconductor base body is a wide bandgap semiconductor.

10. The semiconductor device according to claim 1 , wherein a substrate on which the semiconductor base body is deposited is a semi-insulating substrate or an insulating substrate.

11. The semiconductor device according to claim 1 , wherein a substrate on which the semiconductor base body is deposited includes a common material used for the drift region.

12. The semiconductor device according to claim 1 , wherein a substrate on which the semiconductor base body is deposited is a silicon carbide substrate.

Assignees

• Nissan Motor
• Renault Sas

Inventors

• Marui Toshiharu
• Hayashi Tetsuya
• Numakura Keiichiro
• Ni Wei
• Tanaka Ryota
• Takemoto Keisuke

Classifications

• H10P30/2042

  into crystalline silicon carbide · CPC title

• H10P30/21

  of electrically active species · CPC title

• H10W10/031

  of isolation regions comprising PN junctions · CPC title

• H10W10/30

  Isolation regions comprising PN junctions · CPC title

• H10W10/01

  Manufacture or treatment · CPC title