Semiconductor device having trench shield electrode structure

• US 7,915,672 B2
• Filed: 11/14/2008
• Issued: 03/29/2011
• Est. Priority Date: 11/14/2008
• Status: Active Grant

• Current Assignee: Semiconductor Components Industries LLC (ON Semiconductor Corporation)
• Original Assignee: Semiconductor Components Industries LLC (ON Semiconductor Corporation)
• Inventors: Venkatraman, Prasad
• Primary Examiner(s): Pham; Hoai v
• Application Number:
  US12/271,041
• Publication Number:
  US 20100123188A1
• Time in Patent Office: 865 Days
• Field of Search: 257/330, 257/331, 257/332, 257/E27.091
• US Class Current: 257/330
• CPC Class Codes: H01L 29/407 Recessed field plates, e.g. trench field plates, buried field plates
• CPC Class Codes: H01L 29/41741 for vertical or pseudo-vertical devices
• CPC Class Codes: H01L 29/41766 with at least part of the source or drain electrode having contact below the semiconductor surface, e.g. the source or drain electrode formed at least partially in a groove or with inclusions of conductor inside the semiconductor H01L29/41733 - H01L29/41758 take precedence
• CPC Class Codes: H01L 29/4238 characterised by the surface lay-out
• CPC Class Codes: H01L 29/4925 with a multiple layer structure, e.g. several silicon layers with different crystal structure or grain arrangement with only a vertical doping structure or vertical doping variation H01L29/4916
• CPC Class Codes: H01L 29/4933 with a silicide layer contacting the silicon layer, e.g. Polycide gate with a barrier layer between the silicide and silicon layers H01L29/4941
• CPC Class Codes: H01L 29/66727 with a step of recessing the source electrode
• CPC Class Codes: H01L 29/66734 with a step of recessing the gate electrode, e.g. to form a trench gate electrode
• 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 29/7813 with trench gate electrode, e.g. UMOS transistors trench gate electrodes per se H01L29/4236
• 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

In one embodiment, a structure for a semiconductor device having a trench shield electrode includes a control pad, control runners, shield runners, and a control/shield electrode contact structure. The structure is configured to use a single level of metal to connect the various components. In another embodiment, a shield runner is placed in an offset from center configuration.

Claims

1. A semiconductor device structure comprising:

a region of semiconductor material including a major surface, first and second opposing edges, and a first corner;

a first trench structure formed in an active area of the semiconductor device, wherein the first trench structure includes a first control electrode and a first shield electrode;

a first source region formed adjacent the first trench structure in the active area;

a first contact structure formed adjacent the first edge, wherein the first control electrode and the first shield electrode terminate in the first contact structure, and wherein the first trench structure extends from the active area to the first contact structure;

a control pad formed overlying the major surface;

a first control runner formed overlying the major surface and coupled to the control pad and the first control electrode in the first contact structure, wherein the first control runner has a first end portion;

a first shield electrode runner formed overlying the major surface and coupled to the first shield electrode in the first contact structure; and

a first conductive layer coupled to the first source region in the active area and coupled to the first shield electrode runner, wherein the first conductive layer further includes a first portion that wraps around the first end portion.

2. The structure of claim 1, wherein the control pad is formed adjacent the first corner and the first edge, the structure further comprising a contact region for making contact to the first shield electrode in the active area, wherein the contact region is placed closer to the second edge than the first edge.

3. The structure of claim 1, wherein the first control runner, the first shield electrode runner and the first conductive layer do not overlap.

4. The structure of claim 1, wherein the first control runner, the first shield electrode runner and the first conductive layer comprise the same conductive material.

5. The structure of claim 1 further comprising:

a second contact structure formed adjacent the second edge, wherein the first shield electrode further extends from the active area to the second contact structure and terminates in the second contact structure;

a second control runner formed overlying the major surface and coupled to the control pad and terminating in the second contact structure with a second end portion; and

a second shield electrode runner formed overlying the major surface and coupled to the first shield electrode in the second contact structure, wherein the first conductive layer is coupled to the second shield electrode runner, and wherein the first conductive layer further includes a second portion that wraps around the second end portion.

6. The structure of claim 5 further comprising a third control runner formed overlying the major surface adjacent a third edge, wherein the third control runner connects the control pad to the second control runner.

7. The structure of claim 6, wherein the control pad is formed adjacent the first corner and the first edge, the structure further comprising a contact region for making contact to the first shield electrode in the active area, wherein the contact region is placed closer to the second edge than the first edge.

8. The structure of claim 1, wherein the semiconductor device comprises a MOSFET.

9. The structure of claim 1 further comprising a second control runner formed overlying the major surface, wherein the second control runner is connected to the control pad and further connected to the first control runner at a substantially central location.

10. The structure of claim 1, wherein the first control runner makes contact to the first control electrode inside of the first trench structure in the first contact structure.

11. A semiconductor device structure comprising:

a region of semiconductor material having a major surface and first and second opposing edges;

a trench extending in a first direction from the first edge to the second edge;

a shield electrode formed in the trench;

a first contact to the shield electrode formed adjacent the first edge;

a second contact to the shield electrode formed adjacent the second edge; and

a third contact to the shield electrode offset from a center of the trench along the first direction so that the third contact is closer to the first edge than the second edge.

12. The structure of claim 11 further comprising a first gate electrode formed in the trench extending from adjacent the first edge and terminating before the third contact.

13. The structure of claim 12 further comprising a first gate runner contacting the first gate electrode adjacent the first edge, wherein the first gate runner has a first end portion, and wherein the first contact further wraps around the first end portion.

14. The structure of claim 12 further comprising a second gate electrode formed in the trench extending from adjacent the second edge and terminating before the third contact.

15. The structure of claim 11, wherein the semiconductor comprises a trench MOSFET.

16. A semiconductor device structure comprising:

a region of semiconductor material including a major surface, first and second opposing edges, and a first corner;

a first trench structure formed in an active area of the semiconductor device, wherein the first trench structure includes a first control electrode and a first shield electrode;

a first source region formed adjacent the first trench structure in the active area;

a first contact structure formed adjacent the first edge, wherein the first control electrode and the first shield electrode terminate in the first contact structure, and wherein the first trench structure extends from the active area to the first contact structure;

a control pad formed overlying the major surface adjacent the first corner and the first edge;

a first control runner formed overlying the major surface and coupled to the control pad and the first control electrode in the first contact structure, wherein the first control runner has a first end portion;

a first shield electrode runner formed overlying the major surface and coupled to the first shield electrode in the first contact structure;

a first conductive layer coupled to the first source region in the active area and coupled to the first shield electrode runner, the first conductive layer further including a first portion that wraps around the first end portion; and

a contact region for making contact to the first shield electrode in the active area, wherein the contact region is placed closer the second edge than the first edge.

17. The structure of claim 16, wherein the first control runner, the first shield electrode runner and the first conductive layer do not overlap.

18. The structure of claim 16, wherein the first control runner, the first shield electrode runner and the first conductive layer comprise the same conductive material.

19. The structure of claim 16 further comprising:

a second trench structure formed in the active area of the semiconductor device, wherein the second trench structure includes a second control electrode and a second shield electrode;

a second source region formed adjacent the second trench structure in the active area;

a second contact structure formed adjacent the second edge, wherein the second control electrode and the second shield electrode terminate in the second contact structure, and wherein the second trench structure extends from the active area to the second contact structure;

a second control runner formed overlying the major surface and coupled to the control pad and the second control electrode in the second contact structure, wherein the second control runner has a second end portion; and

a second shield electrode runner formed overlying the major surface and coupled to the second shield electrode in the second contact structure, wherein the first conductive layer is coupled to the second source region in the active area and coupled to the second shield runner, and wherein the first conductive layer further includes a second portion that wraps around the second end portion.

20. The structure of claim 16 further comprising a second control runner formed overlying the major surface, wherein the second control runner is connected to the control pad and further connected to the first control runner at a substantially central location.

21. A semiconductor device structure comprising:

a region of semiconductor material having a major surface, first and second opposing edges, and an interior portion;

a trench extending in a first direction from the first edge to the second edge;

a shield electrode formed in the trench;

a control electrode formed in a portion of the trench and extending to the first edge;

a first contact contacting the control electrode adjacent the first edge; and

a second contact contacting the shield electrode at the interior portion.