Power semiconductor device

• US 9,064,925 B2
• Filed: 09/24/2012
• Issued: 06/23/2015
• Est. Priority Date: 03/23/2010
• Status: Active Grant

• Current Assignee: Hitachi Energy Limited
• Original Assignee: ABB Technology AG (ABB Limited)
• Inventors: Rahimo, Munaf, Kopta, Arnost, Von Arx, Christoph, Andenna, Maxi
• Primary Examiner(s): Montalvo, Eva Y
• Assistant Examiner(s): LAIR, SAMUEL L
• Application Number:
  US13/625,591
• Publication Number:
  US 20130026537A1
• Time in Patent Office: 1,002 Days
• Field of Search: 257/139, 257/140, 257/141, 257/142, 257/143, 257/144, 257/145, 257/E29.027, 257/E29.066, 257/E29.197, 257/E29.198, 257/E29.2, 257/E21.382, 257/E21.383, 257/E21.384, 257/E21.385, 438/133, 438/134, 438/135, 438/136, 438/137, 438/138, 438/139, 438/140
• US Class Current: 1/1
• CPC Class Codes: H01L 29/4232 with insulated gate
• CPC Class Codes: H01L 29/7395 Vertical transistors, e.g. vertical IGBT
• 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 power semiconductor device is disclosed with layers of different conductivity types between an emitter electrode on an emitter side and a collector electrode on a collector side. The device can include a drift layer, a first base layer in direct electrical contact to the emitter electrode, a first source region embedded into the first base layer which contacts the emitter electrode and has a higher doping concentration than the drift layer, a first gate electrode in a same plane and lateral to the first base layer, a second base layer in the same plane and lateral to the first base layer, a second gate electrode on top of the emitter side, and a second source region electrically insulated from the second base layer, the second source region and the drift layer by a second insulating layer.

Claims

1. A power semiconductor, comprising:

a drift layer of a first conductivity type arranged between an emitter electrode on an emitter side and a collector electrode on a collector side of the device;

a first base layer of a second conductivity type arranged between the drift layer and the emitter electrode, which first base layer is in direct electrical contact to the emitter electrode;

a first source region of the first conductivity type arranged at the emitter side embedded into the first base layer in contact with the emitter electrode, which first source region has a higher doping concentration than the drift layer;

a plurality of first gate electrodes, each electrically insulated from the first base layer, the first source region and the drift layer by a first insulating layer, which first gate electrode is arranged in a same plane and lateral to the first base layer and extends deeper into the drift layer than the first base layer, a channel being formable between the emitter electrode, the first source region, the first base layer and the drift layer; and

a second base layer of the second conductivity type, a second source region of the first conductivity type and a second gate electrode, wherein;

the second gate electrode is arranged outside an area between the emitter side and the collector side, the second gate electrode is electrically insulated from the second base layer, the second source region and the drift layer by a second insulating layer;

wherein;

the second source region is arranged at the emitter side embedded into the second base layer and extends into a region past the second gate electrode, which second source region has a higher doping concentration than the drift layer;

wherein;

the second base layer is arranged in a same plane and lateral to the first base layer; and

wherein the first and second source regions are connected to each other by a connection source region, which is arranged between two such first gate electrodes and thereby separates said two first gate electrodes.

2. Device according to claim 1, wherein the second source region is separated from the emitter electrode so as to preclude charge carrier flow directly from the emitter electrode, through the second source region and the second base layer, to the drift layer.

3. Device according to claim 1, wherein the first and second gate electrodes are electrically connected.

4. Device according to claim 1, comprising:

a buffer layer of the first conductivity type with a higher doping concentration than the drift layer, arranged between the drift layer and the collector electrode.

5. Device according to claim 1, comprising:

a collector layer of the second conductivity type arranged on the collector side between the drift layer and the collector electrode;

or comprising;

a buffer layer of the first conductivity type with a higher doping concentration than the drift layer, which buffer layer is arranged on the collector side between the drift layer and the collector electrode; and

a collector layer of the second conductivity type, which is arranged on the collector side between the buffer layer and the collector electrode.

6. Device according to claim 1, wherein the second source region extends to the first insulating layer.

7. Device according to claim 1, wherein the second source region is separated from the first insulating layer by the second base layer.

8. Device according to claim 1, wherein the second source region is electrically connected to the emitter electrode.

9. Device according to claim 1, wherein the second source region is electrically insulated from the emitter electrode.

10. Device according to claim 1, comprising:

a first region of the first conductivity type arranged on the collector side lateral to the collector layer, which first region has a higher doping concentration than the drift layer.

11. Device according to claim 1, comprising:

an enhancement layer of the first conductivity type arranged between and thereby separating the drift layer and at least one or both of the first and second base layer.

12. Device according to claim 10, comprising:

a third base layer of the second conductivity type arranged between and thereby separating the drift layer and the enhancement layer below the first base layer, the second base layer or both of the first and second base layer.

13. Device according to claim 1, comprising:

a plurality of first gate electrodes, wherein the first and second base layers are connected to each other by a connection base layer arranged between two such first gate electrodes to thereby separate said two first gate electrodes.

14. Device according to claim 1, comprising:

a bar of the second conductivity type with a higher doping concentration than the first and second base layers, which bar is arranged at the emitter side and at which bar the first and second source regions, the base layers and the first gate electrode terminate.

15. Device according to claim 14, wherein the bar is at least partly or completely covered by the second gate electrode.

16. Device according to claim 1, wherein the second source region is separated from any electrode on the emitter side by a third insulating layer covering the second source region in a first area, and wherein the connection source region is connected to the emitter electrode either directly or via the first source region.

17. Device according to claim 2, comprising:

a buffer layer of the first conductivity type with a higher doping concentration than the drift layer, arranged between the drift layer and the collector electrode.

18. Device according to claim 17, wherein the second source region extends to the first insulating layer.

19. Device according to claim 18, wherein the second source region is electrically connected to the emitter electrode.

20. Device according to claim 19, comprising:

a first region of the first conductivity type arranged on the collector side lateral to the collector layer, which first region has a higher doping concentration than the drift layer.

21. Device according to claim 20, comprising:

an enhancement layer of the first conductivity type arranged between and thereby separating the drift layer and at least one or both of the first and second base layer.

22. Device according to claim 21, comprising:

a plurality of first gate electrodes, wherein the first and second base layers are connected to each other by a connection base layer arranged between two such first gate electrodes to thereby separate said two first gate electrodes.

23. Device according to claim 22, comprising:

a bar of the second conductivity type with a higher doping concentration than the first and second base layers, which bar is arranged at the emitter side and at which bar the first and second source regions, the base layers and the first gate electrode terminate.