Semiconductor device having junction-termination structure of resurf type

• US 6,765,239 B2
• Filed: 07/02/2002
• Issued: 07/20/2004
• Est. Priority Date: 07/06/2001
• Status: Expired due to Term

• Current Assignee: North Plate Semiconductor, LLC
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Hiyoshi, Michiaki, Hasegawa, Shigeru, Inoue, Naoyuki, Harada, Tatsuo
• Primary Examiner(s): Pham, Long
• Assistant Examiner(s): Farahani, Dana
• Application Number:
  US10/187,369
• Publication Number:
  US 20030006497A1
• Time in Patent Office: 749 Days
• Field of Search: 257/168, 257/169, 257/170, 257/171, 257/172, 257/119, 257/120, 257/121, 257/122, 257/123, 257/124, 257/125, 257/128, 257/131, 257/688, 257/129, 257/155, 257/62, 257/126, 257/130, 257/132, 257/133, 257/134, 257/135, 257/141, 257/142
• US Class Current: 257/107
• CPC Class Codes: H01L 29/405 Resistive arrangements, e.g. resistive or semi-insulating field plates
• CPC Class Codes: H01L 29/7395 Vertical transistors, e.g. vertical IGBT

Abstract

A semiconductor device includes an active region with a main semiconductor device section, and a junction-termination region therearound. A first diffusion layer of a second conductivity type is formed in a surface of a first semiconductor layer of a first conductivity type, and extends from the active region into the junction-termination region. A second diffusion layer of the second conductivity type is formed in contact with the first diffusion layer, and extends in the junction-termination region. A first contact electrode is disposed in the active region and in contact with the first diffusion layer, and electrically connected to a first main electrode of the main semiconductor device section. A second contact electrode is disposed in the junction-termination region and in contact with the first diffusion layer, and surrounds the active region. A connection electrode electrically connects the first and second contact electrodes to each other.

Claims

1. A semiconductor device including an active region where a main semiconductor device section is disposed, and a junction-termination region located around the active region, the device comprising:

a semiconductor layer of a first conductivity type, disposed as a semiconductor active layer common to the active region and the junction-termination region;

a first diffusion layer of a second conductivity type formed in a surface of the semiconductor layer, and extending from the active region into the junction-termination region;

a second diffusion layer of the second conductivity type formed in a surface of the semiconductor layer and in contact with the first diffusion layer, the second diffusion layer extending in the junction-termination region, and having a carrier impurity concentration lower than that of the first diffusion layer;

a first contact electrode disposed in the active region and in contact with the first diffusion layer, and electrically connected to a first main electrode of the main semiconductor device section;

a second contact electrode disposed in the junction-termination region and in contact with the first diffusion layer, and surrounding the active region; and

a connection electrode electrically connecting the first and second contact electrodes to each other,

wherein the main semiconductor device section comprises a second main electrode extending from the active region into the junction-termination region, and, when the main semiconductor device section is turned off, a current flows in the junction-termination region from the second main electrode, through the semiconductor layer and the first diffusion layer, into the second contact electrode.

2. A device according to claim 1, wherein the junction-termination region comprises a plurality of linear side portions extending along a contour of the active region and a plurality of corner portions connecting the side portions, and the connection electrode is not disposed at the side portions, but disposed at the corner portions.

3. A device according to claim 1, wherein the main semiconductor device section comprises:

a first base layer of the first conductivity type, which is part of the semiconductor layer;

a second base layer of the second conductivity type disposed on the first base layer;

an emitter layer of the first conductivity type disposed on the second base layer;

a collector layer of the second conductivity type disposed on the first base layer and separated from the second base layer;

a gate electrode facing, through a gate insulating film, a portion of the second base layer sandwiched between the first base layer and the emitter layer,

the first main electrode disposed in contact with the second base layer and the emitter layer, and electrically connected to the first contact electrode; and

the second main electrode in contact with the collector layer.

4. A device according to claim 3, wherein the second base layer is formed in a surface of the first base layer reverse to the collector layer, and the emitter layer is formed in a surface of the second base layer.

5. A device according to claim 4, wherein the second base layer and the first diffusion layer have substantially the same carrier impurity concentration.

6. A device according to claim 3, wherein the collector layer and the second main electrode extend from the active region into the junction-termination region.

7. A device according to claim 1, wherein the connection electrode is disposed in contact with the first diffusion layer.

8. A device according to claim 1, wherein the first contact electrode, the second contact electrode, and the connection electrode are integrally formed.

9. A device according to claim 1, wherein, in a first direction connecting the active region to the junction-termination region with a shortest distance, a distance between an innermost position where the first contact electrode is in contact with the first diffusion layer, and an outermost position where the second contact electrode is in contact with the first diffusion layer is set to fall in a range of from 10 to 300 μ

m.

10. A semiconductor device including an active region, a junction-termination region located around the active region, and an intermediate region interposed between the active region and the junction-termination region, the device comprising:

a first semiconductor layer of a first conductivity type, disposed as a semiconductor active layer common to the active region, the intermediate region, and the junction-termination region;

a second semiconductor layer of a second conductivity type formed in one surface of the first semiconductor layer in the active region;

a third semiconductor layer of the first conductivity type formed in a surface of the second semiconductor layer;

a fourth semiconductor layer disposed on or in another surface of the first semiconductor layer in the active region;

a gate electrode facing, through a gate insulating film, a portion of the second semiconductor layer sandwiched between the first semiconductor layer and the third semiconductor layer;

a first main electrode disposed in contact with the second semiconductor layer and the third semiconductor layer;

a second main electrode disposed in contact with the fourth semiconductor layer;

a first diffusion layer of a second conductivity type formed in a surface of the first semiconductor layer on the same side as the second semiconductor layer, and extending from the active region through the intermediate region into the junction-termination region, the second semiconductor layer and the first diffusion layer having substantially the same carrier impurity concentration;

a second diffusion layer of the second conductivity type formed in a surface of the first semiconductor layer and in contact with the first diffusion layer, the second diffusion layer extending in the junction-termination region, and having a carrier impurity concentration lower than that of the first diffusion layer;

a first contact electrode disposed in the active region and in contact with the first diffusion layer, and electrically connected to the first main, electrode;

a second contact electrode disposed in the junction-termination region and in contact with the first diffusion layer, and surrounding the active region; and

a connection electrode disposed in the intermediate region, and electrically connecting the first and second contact electrodes to each other.

11. A device according to claim 10, wherein the fourth semiconductor layer and the second main electrode extend from the active region into the junction-termination region.

12. A device according to claim 10, wherein the first semiconductor layer comprises a high concentration layer disposed on the fourth semiconductor layer side, and a low concentration layer disposed on the second semiconductor layer side and having a carrier impurity concentration lower than that of the high concentration layer.

13. A device according to claim 10, wherein the junction-termination region comprises a plurality of linear side portions extending along a contour of the active region and a plurality of corner portions connecting the side portions, and the connection electrode is not disposed at the side portions, but disposed at the corner portions.

14. A device according to claim 13, further comprising a lead-out wiring layer connected to the gate electrode, and disposed between the first and second contact electrodes at each of the corner portions, while being insulated from the first and second contact electrodes.

15. A device according to claim 10, wherein the first, second, third, and fourth semiconductor layers are a first base layer, a second base layer, an emitter layer, and a collector layer, respectively.

16. A device according to claim 10, wherein the connection electrode is disposed in contact with the first diffusion layer.

17. A device according to claim 10, further comprising a high-resistance conductive film disposed on a surface of the second diffusion layer.

18. A device according to claim 10, wherein the first contact electrode, the second contact electrode, and the connection electrode are integrally formed.

19. A device according to claim 10, wherein, in a first direction connecting the active region to the junction-termination region with a shortest distance, a distance between an innermost position where the first contact electrode is in contact with the first diffusion layer, and an outermost position where the second contact electrode is in contact with the first diffusion layer is set to fall in a range of from 10 to 300 μ

m.

20. A semiconductor device including an active region where a main semiconductor device section is disposed, and a junction-termination region located around the active region, the device comprising:

a semiconductor layer of a first conductivity type, disposed as a semiconductor active layer common to the active region and the junction-termination region;

a first diffusion layer of a second conductivity type formed in a surface of the semiconductor layer, and extending from the active region into the junction-termination region;

a second diffusion layer of the second conductivity type formed in a surface of the semiconductor layer and in contact with the first diffusion layer, the second, diffusion layer extending in the junction-termination region, and having a carrier impurity concentration lower than that of the first diffusion layer;

a first contact electrode disposed in the active region and in contact with the first diffusion layer, and electrically connected to a first main electrode of the main semiconductor device section;

a second contact electrode disposed in the junction-termination region and in contact with the first diffusion layer, and surrounding the active region; and

a connection electrode electrically connecting the first and second contact electrodes to each other,

wherein the main semiconductor device section comprises;

a first base layer of the first conductivity type, which is part of the semiconductor layer;

a second base layer of the second conductivity type disposed on the first base layer;

an emitter layer of the first conductivity type disposed on the second base layer;

a collector layer of the second conductivity type disposed on the first base layer and separated from the second base layer;

a gate electrode facing, through a gate insulating film, a portion of the second base layer sandwiched between the first base layer and the emitter layer;

the first main electrode disposed in contact with the second base layer and the emitter layer, and electrically connected to the first contact electrode; and

a second main electrode in contact with the collector layer.

21. A device according to claim 20, wherein the junction-termination region comprises a plurality of linear side portions extending along a contour of the active region and a plurality of corner portions connecting the side portions, and the connection electrode is not disposed at the side portions, but disposed at the corner portions.

22. A device according to claim 20, wherein the connection electrode is disposed in contact with the first diffusion layer.

23. A device according to claim 20, wherein the first contact electrode, the second contact electrode, and the connection electrode are integrally formed.

24. A device according to claim 20, wherein, in a first direction connecting the active region to the junction-termination region with a shortest distance, a distance between an innermost position where the first contact electrode is in contact with the first diffusion layer, and an outermost position where the second contact electrode is in contact with the first diffusion layer is set to fall in a range of from 10 to 300 μ

m.