IP Library › Granted Patent US 12,315,729
Granted Patent B1
US 12,315,729 · App. 18/661,994 · Granted May 27, 2025

Laser-based processing for semiconductor wafers

Inventor: Devon Michael Diehl (Durham, NC)
Assignee: WOLFSPEED, INC.
H01L21/268B23K26/38B23K26/40H10D62/8325
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Quick Facts
Patent No.
US 12,315,729
App. No.
18/661,994
Granted
May 27, 2025
Kind
B1
Abstract

An example method includes providing a first semiconductor workpiece including a first portion and a second portion. The example method includes providing emission of one or more lasers through a thickness of the first semiconductor workpiece to remove the first portion of the first semiconductor workpiece from the second portion. In some implementations, the second portion has a shape corresponding to a second semiconductor workpiece of a different diameter relative to the first semiconductor workpiece.

Claims (27)

1. A method for fabricating a semiconductor workpiece, comprising:

providing a first semiconductor workpiece comprising a first portion and a second portion;

identifying the first portion of the semiconductor workpiece based on a workpiece property present in the first portion of the semiconductor workpiece; and

providing emission of one or more lasers through a thickness of the first semiconductor workpiece to remove the first portion of the first semiconductor workpiece from the second portion;

wherein the second portion has a shape corresponding to a second semiconductor workpiece of a different diameter relative to the first semiconductor workpiece;

wherein providing emission of one or more lasers comprises determining a cut line separating the first portion from the second portion based at least in part on the identification of the first portion.

2. The method of claim 1 , wherein providing emission of the one or more lasers through the thickness of the first semiconductor workpiece comprises ablating semiconductor material of the first semiconductor workpiece separating the first portion and the second portion with the one or more lasers.

3. The method of claim 1 , wherein the first semiconductor workpiece comprises a wide bandgap semiconductor.

4. The method of claim 1 , wherein the first semiconductor workpiece comprises silicon carbide.

5. The method of claim 1 , wherein the first semiconductor workpiece comprises a Group III-nitride.

6. The method of claim 1 , wherein the first semiconductor workpiece is a semiconductor wafer.

7. The method of claim 1 , wherein the first semiconductor workpiece is a semiconductor boule.

8. The method of claim 1 , wherein after providing emission of the one or more lasers through the thickness of the first semiconductor workpiece, an outer surface of the second semiconductor workpiece has a flared edge.

9. The method of claim 8 , further comprising: grinding the outer surface of the second semiconductor workpiece after providing emission of the one or more lasers through the thickness of the first semiconductor workpiece.

10. The method of claim 9 , wherein grinding the outer surface of the second semiconductor workpiece reduces a diameter of the second semiconductor workpiece to a finished workpiece diameter.

11. The method of claim 1 , wherein the first portion comprises a crystal growth defect.

12. The method of claim 1 , wherein the first portion comprises an edge chip defect.

13. The method of claim 1 , wherein the first portion comprises an over-edge grind defect.

14. The method of claim 1 , wherein providing emission of the one or more lasers through the thickness of the first semiconductor workpiece comprises imparting relative motion between the first semiconductor workpiece and the one or more lasers.

15. The method of claim 1 , further comprising:

obtaining data indicative of a workpiece property;

determining one or more laser parameters based on data indicative of the workpiece property; and

providing emission of the one or more lasers through the thickness of the first semiconductor workpiece based at least in part on the one or more laser parameters.

16. The method of claim 15 , wherein the one or more laser parameters comprise one or more of laser power, laser wavelength, laser pulse energy, laser pulse duration, or translation speed.

17. The method of claim 15 , wherein the one or more laser parameters are specified as a function of position on the first semiconductor workpiece.

18. The method of claim 1 , wherein the first semiconductor workpiece has a diameter of about 200 mm and the second semiconductor workpiece has a diameter of about 150 mm.

19. The method of claim 1 , wherein the first semiconductor workpiece has a diameter of about 200 mm and the second semiconductor workpiece has a diameter of about 100 mm.

Assignments (8)
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 →
RELEASE OF SECURITY INTEREST IN INTELLECTUAL PROPERTY COLLATERAL AT REEL/FRAME NO. 69180/0437 Recorded Sep 30, 2025
From: U.S. BANK TRUST COMPANY, NATIONAL ASSOCIATION, AS COLLATERAL AGENT
To: WOLFSPEED, INC.
Reel/Frame 072989/0088 →
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 →
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 072992/0467 →
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 →
SECURITY INTEREST Recorded Oct 17, 2024
From: WOLFSPEED, INC.
To: U.S. BANK TRUST COMPANY, NATIONAL ASSOCIATION, AS COLLATERAL AGENT
Reel/Frame 069180/0437 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Sep 5, 2024
From: DIEHL, DEVON MICHAEL
To: WOLFSPEED, INC.
Reel/Frame 068500/0643 →
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