Semiconductor device

Patent metadata

Field	Value
Publication number	US-9478648-B2
Application number	US-201514959877-A
Country	US
Kind code	B2
Filing date	Dec 4, 2015
Priority date	Jan 19, 2015
Publication date	Oct 25, 2016
Grant date	Oct 25, 2016

Abstract

A shield electrode is formed above a floating p region in a semiconductor layer and connected to a gate electrode in a trench. The shield electrode is composed of a material having an electrical resistivity lower than that of the gate electrode.

First claim

What is claimed is:

1. A semiconductor device, comprising:
a first semiconductor layer of a first conductivity type;
a second semiconductor layer of a second conductivity type provided on one surface of the first semiconductor layer;
a third semiconductor layer of the first conductivity type selectively provided in the second semiconductor layer;
a fourth semiconductor layer of the second conductivity type selectively provided in the second semiconductor layer so as to be adjacent and connected to the third semiconductor layer;
trenches each penetrating the second semiconductor layer to reach the first semiconductor layer, dividing the second semiconductor layer into a base region and a floating region, the base region having the third and fourth semiconductor layers therein, one sidewall of each of the trenches abutting the third semiconductor layer;
a fifth semiconductor layer of the second conductivity type provided below and electrically connected to another surface of the first semiconductor layer;
an emitter electrode electrically connected to the third semiconductor layer and the fourth semiconductor layer and electrically insulated from the floating region of the second semiconductor layer;
a collector electrode electrically connected to the fifth semiconductor layer;
a gate electrode provided in each of the trenches;
a gate insulating film provided in each of the trenches between the corresponding gate electrode and the trench;
a shield electrode provided over the floating region of the second semiconductor layer, the shield electrode being made of a material having an electrical resistivity lower than that of the gate electrode and being electrically connected to the gate electrode; and
an insulating film provided between the shield electrode and the floating region of the second semiconductor layer.

2. The semiconductor device according to claim 1 ,
wherein the shield electrode is made of a conductive film including a single film or a multilayer film comprising one or more of a metal silicide, a metal having a high melting point, and a metallic nitride having a high melting point.

3. The semiconductor device according to claim 2 ,
wherein a film thickness of the shield electrode is 10 nm to 800 nm.

4. The semiconductor device according to claim 3 ,
wherein the shield electrode laterally extends above the trench to directly connect to the gate electrode.

5. The semiconductor device according to claim 4 ,
wherein the insulating film disposed between the shield electrode and the floating region has a thickness greater than that of the gate insulating film.

6. The semiconductor device according to claim 3 ,
wherein the insulating film disposed between the shield electrode and the floating region has a thickness greater than that of the gate insulating film.

7. The semiconductor device according to claim 2 ,
wherein the shield electrode laterally extends above the trench to directly connect to the gate electrode.

8. The semiconductor device according to claim 7 ,
wherein the insulating film disposed between the shield electrode and the floating region has a thickness greater than that of the gate insulating film.

9. The semiconductor device according to claim 2 ,
wherein the insulating film disposed between the shield electrode and the floating region has a thickness greater than that of the gate insulating film.

10. The semiconductor device according to claim 1 ,
wherein a film thickness of the shield electrode is 10 nm to 800 nm.

11. The semiconductor device according to claim 10 ,
wherein the shield electrode laterally extends above the trench to directly connect to the gate electrode.

12. The semiconductor device according to claim 11 ,
wherein the insulating film disposed between the shield electrode and the floating region has a thickness greater than that of the gate insulating film.

13. The semiconductor device according to claim 10 ,
wherein the insulating film disposed between the shield electrode and the floating region has a thickness greater than that of the gate insulating film.

14. The semiconductor device according to claim 1 ,
wherein the shield electrode laterally extends above the trench to directly connect to the gate electrode.

15. The semiconductor device according to claim 14 ,
wherein the insulating film disposed between the shield electrode and the floating region has a thickness greater than that of the gate insulating film.

16. The semiconductor device according to claim 1 ,
wherein the insulating film disposed between the shield electrode and the floating region has a thickness greater than that of the gate insulating film.

Assignees

• Fuji Electric Co Ltd

Inventors

• Ikura Yoshihiro

Classifications

• H10D84/641

  Combinations of only vertical BJTs (vertical complementary BJTs H10D84/673) · CPC title

• H10D64/111

  Field plates · CPC title

• H10D62/393

  Body regions of DMOS transistors or IGBTs  (cell layout of DMOS H10D62/127) · CPC title

• H10D62/137

  Collector regions of BJTs · CPC title

• H10D62/133

  Emitter regions of BJTs · CPC title