IP Library Granted Patent US 11,869,948
Granted Patent B2
US 11,869,948 · App. 17/177,641 · Granted Jan 9, 2024

Power semiconductor device with reduced strain

Inventors: Daniel Jenner Lichtenwalner (Raleigh, NC); Edward Robert Van Brunt (Raleigh, NC); Thomas E. Harrington, III (Carrollton, TX); Shadi Sabri (Apex, NC); Brett Hull (Raleigh, NC); Brice McPherson (Fayetteville, AR); Joe W. McPherson (Plano, TX)
Assignee: Wolfspeed, Inc.
H01L29/404H01L29/1608
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Quick Facts
Patent No.
US 11,869,948
App. No.
17/177,641
Granted
Jan 9, 2024
Kind
B2
Abstract

Strategic placement and patterning of electrodes, vias, and metal runners can significantly reduce strain in a power semiconductor die. By modifying the path defining electrodes, vias, and metal runners, as well as patterning the material layers thereof, strain can be better managed to increase reliability of a power semiconductor die.

Claims (53)

1. A semiconductor device comprising:

a drift layer that includes an active region;

a runner electrode on the drift layer that extends along a runner electrode path;

and

a runner electrode strain relief region that comprises a closed region in which electrically conductive material is not provided that is surrounded by the runner electrode when the runner electrode is viewed from above.

2. The semiconductor device of claim 1 further comprising:

a runner via that extends along a runner via path, wherein the runner via is an opening in the insulating layer through which the runner electrode is exposed;

an additional runner via that extends along an additional runner via path, wherein the additional runner via is an opening in the insulating layer; and

an additional metal runner along an additional metal runner path, the additional metal runner within the additional runner via to electrically contact the drift layer.

3. The semiconductor device of claim 2 wherein the additional runner via is segmented to provide a plurality of segmented additional runner vias that are separated by a portion of the insulating layer.

4. The semiconductor device of claim 3 wherein the additional runner via path is not the same as the additional metal runner path.

5. The semiconductor device of claim 3 wherein one or more of the plurality of segmented additional runner vias comprise a first via portion that intersects a second via portion.

6. The semiconductor device of claim 1 further comprising an electrode mesh over the active region and coupled to the runner electrode, the electrode mesh comprising a grid of electrode mesh runners running between opposing sides of inner edges of the runner electrode.

7. The semiconductor device of claim 6 wherein the runner electrode strain relief region is not positioned so that it is intersected by a line defining the path of any one of the grid of electrode mesh runners.

8. The semiconductor device of claim 1 wherein the insulating layer fills the runner electrode strain relief region.

9. The semiconductor device of claim 2 wherein the runner via includes a serpentine segment.

10. The semiconductor device of claim 2 wherein the runner via is at least partly in a cross-hatched pattern where a first via portion overlaps a second via portion.

11. The semiconductor device of claim 10 wherein the first via portion is perpendicular to the second via portion.

12. The semiconductor device of claim 1 wherein the metal runner includes curved corners.

13. The semiconductor device of claim 1 wherein a portion of the insulating layer is in between the drift layer and the runner electrode.

14. The semiconductor device of claim 2 wherein the additional metal runner is positioned outside the runner electrode.

15. A semiconductor device comprising:

an active region;

an insulating layer on the active region;

a runner electrode that has curved corners;

a runner via on the runner electrode; and

a metal runner along a metal runner path such that the metal runner fills the runner via.

16. The semiconductor device of claim 15 wherein the runner via is segmented to provide a plurality of segmented runner vias.

17. The semiconductor device of claim 16 wherein one or more of the plurality of segmented runner vias comprise a first via portion that intersects a second via portion.

18. The semiconductor device of claim 15 wherein the runner electrode includes one or more closed runner electrode strain relief regions that do not include an electrically conductive material.

19. The semiconductor device of claim 15 wherein the runner via includes a serpentine segment.

20. The semiconductor device of claim 17 wherein the first via portion is perpendicular to the second via portion.

21. The semiconductor device of claim 16 wherein the segmented runner vias are separated by respective portions of the insulating layer.

22. The semiconductor device of claim 16 further comprising an additional runner via that is segmented to provide a plurality of additional segmented runner vias, wherein the additional runner via is not electrically connected to the runner via.

23. The semiconductor device of claim 15 wherein a width of the metal runner is less than a width of the runner electrode.

24. The semiconductor device of claim 15 wherein a portion of the insulating layer is in between the drift layer and the runner electrode.

25. The semiconductor device of claim 15 further comprising:

an additional runner via that extends along an additional runner via path, wherein the additional runner via is an opening in the insulating layer; and

an additional metal runner along an additional metal runner path, the additional metal runner filling the additional runner via to electrically contact the drift layer,

wherein the additional metal runner includes curved corners.

26. A semiconductor device comprising:

a drift layer that comprises an active region;

a runner electrode on the drift layer;

a metal runner that comprises an electrically conductive material, the metal runner extending along a metal runner path that follows a perimeter of the active region;

an insulating layer, where a portion of the insulating layer is in between the runner electrode and the metal runner;

wherein a width of the metal runner is less than a width of the runner electrode.

27. The semiconductor device of claim 26 wherein the runner electrode includes curved corners.

28. The semiconductor device of claim 26 wherein the additional metal runner includes curved corners.

29. The semiconductor device of claim 26 wherein the metal runner includes curved corners.

30. The semiconductor device of claim 26 , further comprising:

an additional runner via that extends along an additional runner via path, wherein the additional runner via is an opening in the insulating layer; and

an additional metal runner that fills the additional runner via to electrically contact the drift layer.

31. The semiconductor device of claim 26 wherein a portion of the insulating layer is in between the drift layer and the runner electrode.

Assignments (11)
NOTICE OF GRANT OF SECURITY INTEREST IN INTELLECTUAL PROPERTY Recorded Mar 26, 2026
From: WOLFSPEED, INC.
To: U.S. BANK TRUST COMPANY, NATIONAL ASSOCIATION, AS COLLATERAL AGENT
Reel/Frame 075280/0919 →
NOTICE OF GRANT OF SECURITY INTEREST IN INTELLECTUAL PROPERTY Recorded Sep 30, 2025
From: WOLFSPEED, INC.
To: U.S. BANK TRUST COMPANY, NATIONAL ASSOCIATION, AS COLLATERAL AGENT
Reel/Frame 072992/0381 →
NOTICE OF GRANT OF SECURITY INTEREST IN INTELLECTUAL PROPERTY Recorded Sep 30, 2025
From: WOLFSPEED, INC.
To: U.S. BANK TRUST COMPANY, NATIONAL ASSOCIATION, AS COLLATERAL AGENT
Reel/Frame 072992/0588 →
NOTICE OF GRANT OF SECURITY INTEREST IN INTELLECTUAL PROPERTY Recorded Sep 30, 2025
From: WOLFSPEED, INC.
To: U.S. BANK TRUST COMPANY, NATIONAL ASSOCIATION, AS COLLATERAL AGENT
Reel/Frame 072992/0467 →
RELEASE OF SECURITY INTEREST IN INTELLECTUAL PROPERTY COLLATERAL AT REEL/FRAME NO. 64185/0755 Recorded Sep 30, 2025
From: U.S. BANK TRUST COMPANY, NATIONAL ASSOCIATION, AS COLLATERAL AGENT
To: WOLFSPEED, INC.
Reel/Frame 072989/0001 →
NOTICE OF GRANT OF SECURITY INTEREST IN INTELLECTUAL PROPERTY Recorded Sep 30, 2025
From: WOLFSPEED, INC.
To: U.S. BANK TRUST COMPANY, NATIONAL ASSOCIATION, AS COLLATERAL AGENT
Reel/Frame 072992/0113 →
SECURITY INTEREST Recorded Jun 30, 2023
From: WOLFSPEED, INC.
To: U.S. BANK TRUST COMPANY, NATIONAL ASSOCIATION
Reel/Frame 064185/0755 →
CHANGE OF NAME Recorded Oct 22, 2021
From: CREE, INC.
To: WOLFSPEED, INC.
Reel/Frame 057891/0880 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Feb 17, 2021
From: LOU HUTTER CONSULTING LLC
To: CREE, INC.
Reel/Frame 055296/0652 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Feb 17, 2021
From: MCPHERSON, JOE W.
To: LOU HUTTER CONSULTING LLC
Reel/Frame 055296/0574 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Feb 17, 2021
From: LICHTENWALNER, DANIEL JENNER; VAN BRUNT, EDWARD ROBERT; HARRINGTON, THOMAS E., III; SABRI, SHADI; HULL, BRETT; MCPHERSON, BRICE
To: CREE, INC.
Reel/Frame 055296/0327 →