Semiconductor device

• US 20050263852A1
• Filed: 10/28/2004
• Published: 12/01/2005
• Est. Priority Date: 05/28/2004
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Yamaguchi, Masakazu, Inoue, Tomoki, Sugiyama, Koichi, Ogura, Tsuneo, Ninomiya, Hideaki
• Granted Patent: US 7,456,487 B2
• Time in Patent Office: Days
• US Class Current: 257/565
• CPC Class Codes: H01L 29/0834 Anode regions of thyristors or gated bipolar-mode devices, e.g. supplementary regions surrounding anode regions
• CPC Class Codes: H01L 29/1095 Body region, i.e. base region, of DMOS transistors or IGBTs cell layout H01L29/0696
• CPC Class Codes: H01L 29/7397 and a gate structure lying on a slanted or vertical surface or formed in a groove, e.g. trench gate IGBT

Abstract

A semiconductor device comprises a first base layer of a first conductivity type; a plurality of second base layers of a second conductivity type, provided on a part of a first surface of the first base layer; trenches formed on each side of the second base layers, and formed to be deeper than the second base layers; an emitter layer formed along the trench on a surface of the second base layers; a collector layer of the second conductivity type, provided on a second surface of the first base layer opposite to the first surface; an insulating film formed on an inner wall of the trench, the insulating film being thicker on a bottom of the trench than on a side surface of the trench; a gate electrode formed within the trench, and isolated from the second base layers and the emitter layer by the insulating film; and a space section provided between the second base layers adjacent to each other, the space section being deeper than the second base layers and being electrically isolated from the emitter layer and the second base layers.

Claims

1. A semiconductor device comprising:

a first base layer of a first conductivity type;

a plurality of second base layers of a second conductivity type, provided on a part of a first surface of the first base layer;

trenches formed on each side of the second base layers, and formed to be deeper than the second base layers;

an emitter layer formed along the trench on a surface of the second base layers;

a collector layer of the second conductivity type, provided on a second surface of the first base layer opposite to the first surface;

an insulating film formed on an inner wall of the trench, the insulating film being thicker on a bottom of the trench than on a side surface of the trench;

a gate electrode formed within the trench, and isolated from the second base layers and the emitter layer by the insulating film; and

a space section provided between the second base layers adjacent to each other, the space section being deeper than the second base layers and being electrically isolated from the emitter layer and the second base layers.

2. The semiconductor device according to claim 1, wherein the space section includes a semiconductor layer of the second conductivity type, the semiconductor layer being provided between the trenches adjacent to each other.

3. The semiconductor device according to claim 1, wherein a bottom semiconductor layer of the second conductivity type is provided on a bottom of the trench, the bottom semiconductor layer being electrically isolated from the emitter layer and the second base layers.

4. The semiconductor device according to claim 1, wherein a bottom semiconductor layer of the first conductivity type is provided on a bottom of the trench, the bottom semiconductor layer being electrically isolated from the emitter layer and the second base layers, and being higher in impurity concentration than the first base layer.

5. The semiconductor device according to claim 1, wherein the gate electrode is formed above the semiconductor layer through an insulating film.

6. The semiconductor device according to claim 1, wherein the space section includes a semiconductor layer of the first conductivity type, the semiconductor layer being provided between the trenches adjacent to each other and being higher in impurity concentration than the first base layer.

7. The semiconductor device according to claim 1, wherein,

the insulating film being formed to be thicker on a sidewall opposite to a second base layer-side sidewall than the insulating film on the second base layer-side sidewall.

8. A semiconductor device comprising:

a first base layer of a first conductivity type;

a plurality of second base layers of a second conductivity type, provided on a part of a first surface of the first base layer;

trenches formed on each side of the second base layers, and formed to be deeper than the second base layers;

an emitter layer formed along the trench on a surface of the second base layers;

a collector layer of the second conductivity type, provided on a second surface of the first base layer opposite to the first surface;

an insulating film formed on an inner wall of the trench, the insulating film being formed to be thicker on a sidewall opposite to a second base layer-side sidewall than the insulating film on the second base layer-side sidewall;

a gate electrode formed within the trench, and isolated from the second base layers and the emitter layer by the insulating film; and

a space section provided between the second base layers adjacent to each other, the space section being deeper than the second base layers and being electrically isolated from the emitter layer and the second base layers.

9. A semiconductor device comprising:

a first base layer of a first conductivity type;

a plurality of second base layers of a second conductivity type, provided on a part of a first surface of the first base layer;

trenches formed on each side of the second base layers, and formed to be deeper than the second base layers;

an emitter layer formed along the trench on a surface of the second base layers;

a collector layer of the second conductivity type, provided on a second surface of the first base layer opposite to the first surface;

an insulating film formed on an inner wall of the trench;

a gate electrode formed within the trench, and isolated from the second base layers and the emitter layer by the insulating film;

a space section provided between the second base layers adjacent to each other, the space section being electrically isolated from the emitter layer and the second base layers; and

a bottom semiconductor layer of the second conductivity type, provided on a bottom of the trench, and electrically isolated from the emitter layer and the second base layers.

10. The semiconductor device according to claim 9, wherein the insulating film is thicker on a bottom of the trench than on a side surface of the trench.

11. The semiconductor device according to claim 9, wherein the insulating film is formed to be thicker on a sidewall opposite to a second base layer-side sidewall than the insulating film on the second base layer-side sidewall.

12. A semiconductor device comprising:

a first base layer of a first conductivity type;

a plurality of second base layers of a second conductivity type, provided on a part of a first surface of the first base layer;

trenches formed on each side of the second base layers, and formed to be deeper than the second base layers;

an emitter layer formed along the trench on a surface of the second base layers;

a collector layer of the second conductivity type, provided on a second surface of the first base layer opposite to the first surface;

an insulating film formed on an inner wall of the trench;

a gate electrode formed within the trench, and isolated from the second base layers and the emitter layer by the insulating film;

a space section provided between the second base layers adjacent to each other, the space section being electrically isolated from the emitter layer and the second base layers; and

a bottom semiconductor layer of the first conductivity type, provided on a bottom of the trench, the bottom semiconductor layer being electrically isolated from the emitter layer and the second base layers, and being higher in impurity concentration than the first base layer.

13. A semiconductor device comprising:

a first base layer of a first conductivity type;

a plurality of second base layers of a second conductivity type, provided on a part of a first surface of the first base layer;

trenches formed entirely between the second base layers adjacent to each other so as to be wider than the second base layers and to be deeper than the second base layers;

an emitter layer formed along the trench on a surface of the second base layers;

a collector layer of the second conductivity type, provided on a second surface of the first base layer opposite to the first surface;

an insulating film formed on an inner wall of the trench, the insulating film being thicker on the bottom of the trench than on the side surface of the trench; and

a space section including a gate electrode formed within the trench, the gate electrode being isolated from the second base layers and the emitter layer by the insulating film.

14. The semiconductor device according to claim 13, wherein the gate electrode is filled between the insulating films provided on the each side of the trench.

15. The semiconductor device according to claim 13, wherein the gate electrode is provided on the insulating films on each side of the trench,

wherein a insulating-film is, further, filled inside the gate electrode.

16. The semiconductor device according to claim 13 further comprising:

an emitter electrode formed on the insulating film over the gate electrode.

17. A semiconductor device comprising:

a first base layer of a first conductivity type;

a plurality of second base layers of a second conductivity type, provided on a part of a first surface of the first base layer;

trenches formed entirely between the second base layers adjacent to each other so as to be wider than the second base layers and to be deeper than the second base layers;

an emitter layer formed along the trench on a surface of the second base layers;

a collector layer of the second conductivity type, provided on a second surface of the first base layer opposite to the first surface;

an insulating film formed on an inner wall of the trench;

a gate electrode formed within the trench, the gate electrode being isolated from the second base layers and the emitter layer by the insulating film; and

a bottom semiconductor layer of the second conductivity type, provided on a bottom of the trench, the bottom semiconductor layer being electrically isolated from the emitter layer and the second base layers.

18. A semiconductor device comprising:

a first base layer of a first conductivity type;

a plurality of second base layers of a second conductivity type, provided on a part of a first surface of the first base layer;

trenches formed entirely between the second base layers adjacent to each other so as to be wider than the second base layers and to be deeper than the second base layers;

an emitter layer formed along the trench on a surface of the second base layer;

a collector layer of the second conductivity type, provided on a second surface of the first base layer opposite to the first surface;

an insulating film formed on an inner wall of the trench;

a gate electrode formed within the trench, the gate electrode being isolated from the second base layers and the emitter layer by the insulating film; and

a bottom semiconductor layer of the first conductivity type, provided on a bottom of the trench, the bottom semiconductor layer being electrically isolated from the emitter layer and the second base layers, and being higher in impurity concentration than the first base layer.

19. A semiconductor device comprising:

a first base layer of a first conductivity type;

a plurality of second base layers of a second conductivity type, provided on a part of a first surface of the first base layer;

trenches formed on each side of the second base layers, and formed to be deeper than the second base layers;

an emitter layer formed along the trench on a surface of the second base layers;

a collector layer of the second conductivity type, provided on a second surface of the first base layer opposite to the first surface;

an insulating film formed on an inner wall of the trench;

a gate electrode formed within the trench, and isolated from the second base layers and the emitter layer by an insulating film; and

a space section including a semiconductor layer of the first conductivity type, the semiconductor layer being provided between the second base layers adjacent to each other and being electrically isolated from the emitter layer and the second base layers, the semiconductor layer being higher in impurity concentration than the first base layer.

20. The semiconductor device according to claim 19, wherein a bottom semiconductor layer of the second conductivity type is provided on a bottom of the trench, the bottom semiconductor layer being electrically isolated from the emitter layer and the second base layers.

21. The semiconductor device according to claim 19, wherein a bottom semiconductor layer of the first conductivity type is provided on a bottom of the trench, the bottom semiconductor layer being electrically isolated from the emitter layer and the second base layers, and being higher in impurity concentration than the first base layer.

22. The semiconductor device according to claim 19, wherein the insulating film is thicker on a bottom of the trench than on a side surface of the trench.

23. The semiconductor device according to claim 19, wherein the insulating film is formed to be thicker on a sidewall opposite to the second base layer-side sidewall than the insulating film on the second base layer-side sidewall.

24. The semiconductor device according to claim 19, wherein the semiconductor layer is deeper than the second base layers.

25. The semiconductor device according to claim 19 further comprising:

a semiconductor layer of the second conductivity type being provided between the second base layers adjacent to each other and being electrically isolated from the emitter layer and the second base layers, the semiconductor layer being higher in impurity concentration than the first base layer;

wherein the semiconductor layer of the first conductivity type is provided below the semiconductor layer of the second conductivity type.