Semiconductor device having means for diverting short circuit current arranged in trench and method for producing same

• US 7,989,885 B2
• Filed: 02/26/2009
• Issued: 08/02/2011
• Est. Priority Date: 02/26/2009
• Status: Active Grant

• Current Assignee: Infineon Technologies Austria Ag (Infineon Technologies AG)
• Original Assignee: Infineon Technologies Austria Ag (Infineon Technologies AG)
• Inventors: Pfirsch, Frank Dieter, Hirler, Franz
• Primary Examiner(s): Smoot; Stephen W
• Application Number:
  US12/393,210
• Publication Number:
  US 20100213505A1
• Time in Patent Office: 887 Days
• Field of Search: 257/161, 257/490, 257/E27.022, 257/E27.079, 438/336
• US Class Current: 257/330
• CPC Class Codes: H01L 27/0727 in combination with diodes, or capacitors or resistors
• CPC Class Codes: H01L 27/0761 Vertical bipolar transistor in combination with diodes only
• 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 29/0839 Cathode regions of thyristors
• CPC Class Codes: H01L 29/4236 within a trench, e.g. trench gate electrode, groove gate electrode
• CPC Class Codes: H01L 29/66348 with a recessed gate
• 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
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

A semiconductor device has a first semiconductor layer of a first conductivity type and a second semiconductor layer of a second conductivity type complementary to the first conductivity type arranged in or on the first semiconductor layer. The semiconductor device has a region of the first conductivity type arranged in the second semiconductor layer. A first electrode contacts the region of the first conductivity type and the second semiconductor layer. A trench extends into the first semiconductor layer, and a voltage dependent short circuit diverter structure has a highly-doped diverter region of the second conductivity type. This diverter region is arranged via an end of a channel region and coupled to a diode arranged in the trench.

Claims

1. A semiconductor device, comprising:

a first semiconductor layer of a first conductivity type,

a second semiconductor layer of a second conductivity type complementary to the first conductivity type arranged in or on the first semiconductor layer,

a region of the first conductivity type arranged in the second semiconductor layer,

a first electrode contacting the region of the first conductivity type and the second semiconductor layer,

a trench extending into the first semiconductor layer, and

a voltage dependent short circuit diverter structure including a highly-doped diverter region of the second conductivity type arranged via an end of a channel region and coupled to a diode arranged in the trench.

2. The semiconductor device according to claim 1, wherein the highly-doped diverter region is coupled to the first electrode via the diode.

3. The semiconductor device according to claim 1, wherein the diode comprises a region of the first conductivity type and a region of the second conductivity type forming a junction there between.

4. The semiconductor device according to claim 3, wherein the region of the second conductivity type of the diode is in contact with the highly-doped diverter region.

5. The semiconductor device according to claim 1, wherein an insulating layer extends along side walls of the trench and is discontinuous along the base of the trench.

6. The semiconductor device according to claim 1, wherein the trench further comprises a gate electrode, the gate electrode being electrically insulated from the regions of the first conductivity type and the second semiconductor layer and the first semiconductor layer.

7. The semiconductor device according to claim 6, wherein the diode is arranged underneath the gate electrode.

8. The semiconductor device according to claim 1, further comprising a second trench including a gate electrode, the diode being arranged in a trench different from the second trench.

9. The semiconductor device according to claim 1, further comprising a plurality of cells, each cell including a voltage dependent short circuit structure.

10. The semiconductor device according to claim 1, wherein gate electrodes and a voltage dependent short circuit structure are arranged spaced apart to each other in one single trench.

11. The semiconductor device according to claim 1, wherein the highly-doped diverter region is arranged in the vicinity of, and spaced at a distance from, the end of the channel region.

12. The semiconductor device according to claim 1, wherein the semiconductor device provides an insulated gate bipolar transistor.

13. A semiconductor device including a MOS-controlled semiconductor device, comprising:

a channel region;

a trench; and

a voltage dependent short circuit diverter structure including a voltage limiting device arranged in the trench and coupled to a diverter region arranged at an end of the channel region.

14. The semiconductor device according to claim 13, wherein the diverter region is coupled via the voltage limiting device to an electrode of the MOS-controlled semiconductor device.

15. The semiconductor device according to claim 14, wherein the voltage limiting device is a forward-biased diode or a varistor or thyristor or a reverse-biased Zener diode.

16. The semiconductor device according to claim 14, wherein the MOS-controlled device is an insulated gate bipolar transistor.

17. An electronic component including a MOS-controlled semiconductor device, comprising:

a channel;

a trench;

a diverter region arranged at an end of the channel; and

means for diverting a short circuit current arranged in the trench and coupled to the diverter region and to an electrode of the MOS-controlled semiconductor device.

18. The semiconductor device according to claim 17, wherein the means for diverting a short circuit current is a forward-biased pn diode or a varistor or thyristor or a reverse-biased Zener diode.

19. A method for producing a semiconductor device, comprising:

providing a semiconductor substrate including a first semiconductor layer of a first conductivity type, a second semiconductor layer of a second conductivity type complementary to the first conductivity type arranged in or on the first semiconductor layer, a region of the first conductivity type arranged in the second semiconductor layer, a first electrode contacting the region of the first conductivity type and the second semiconductor layer, and a trench extending into the first semiconductor layer,

producing a highly-doped region of the second conductivity type at an end of a channel region,

depositing a layer of the second conductivity type in the trench onto the highly-doped region of the second conductivity type, and

depositing a layer of the first conductivity type in the trench onto the layer of the second conductivity type in the trench producing a junction there between.

20. The method according to claim 19, wherein an insulating layer is deposited in the trench onto the layer of the first conductivity type and a gate electrode is deposited onto the insulating layer.

21. The method according to claim 19, wherein the highly-doped region of the second conductivity type surrounds a base of the trench.

22. The method according to claim 19, wherein the highly-doped region of the second conductivity type is coupled to the first electrode via the layer of the second conductivity type arranged in the trench and the layer of the first conductivity type arranged in the trench.