IP Library Granted Patent US 12,610,767
Granted Patent B2
US 12,610,767 · App. 18/598,859 · Granted Apr 21, 2026

Additives for grinding semiconductor workpieces

Inventors: Simon Bubel (Carrboro, NC); Dinusha Priyadarshani Karunaratne (Cary, NC)
Assignee: Wolfspeed, Inc.
H01L21/30625B24B1/00B24B7/228B24B57/02
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Quick Facts
Patent No.
US 12,610,767
App. No.
18/598,859
Granted
Apr 21, 2026
Kind
B2
Abstract

Systems and methods for grinding semiconductor workpieces are provided. In one example, a method includes providing a surface of the semiconductor workpiece against a grinding apparatus. The grinding apparatus includes an abrasive surface. The method further includes imparting relative motion between the abrasive surface and the semiconductor workpiece to implement a grinding operation on the semiconductor workpiece. The method further includes providing a fluid to the surface of the semiconductor workpiece or the abrasive surface during the grinding operation. The fluid includes an additive. The additive includes one or more of an oxidizing agent, an etchant, a surfactant, or a lubricant.

Claims (35)

1 . A method for grinding a silicon carbide semiconductor workpiece, comprising:

providing a surface of the silicon carbide semiconductor workpiece against a grinding apparatus, the grinding apparatus comprising a grind wheel comprising an abrasive surface, the abrasive surface comprising abrasive elements comprising one or more of diamond, ceramic, metal nitride, metal oxide, metal carbide, metalloid nitride, metalloid oxide, metalloid carbide, carbon group nitride, carbon group oxide, or carbon group carbide;

imparting relative motion between the abrasive surface and the silicon carbide semiconductor workpiece to implement a grinding operation on the silicon carbide semiconductor workpiece; and

providing a fluid to the surface of the silicon carbide semiconductor workpiece or the abrasive surface during the grinding operation;

wherein the fluid comprises an additive, the additive comprising one or more of an oxidizing agent, an etchant, a surfactant, or a lubricant,

wherein the grinding operation reduces a thickness of the silicon carbide semiconductor workpiece by about 0.5 microns or greater, and

wherein the fluid does not contain abrasive particles.

2 . The method of claim 1 , wherein the additive comprises the oxidizing agent.

3 . The method of claim 2 , wherein the oxidizing agent is operable to oxidize one or more grind products during the grinding operation.

4 . The method of claim 2 , wherein the oxidizing agent comprises one or more of hydrogen peroxide, urea peroxide, potassium hypochlorite, sodium hypochlorite, ammonium persulfate, potassium permanganate, potassium periodate, and/or potassium persulfate.

5 . The method of claim 2 , wherein the oxidizing agent comprises an organic peroxide.

6 . The method of claim 5 , wherein the organic peroxide comprises one or more of benzoyl peroxide or dimethyl peroxide.

7 . The method of claim 2 , wherein the oxidizing agent comprises hydrogen peroxide and the fluid comprises one or more Fe+2 compounds.

8 . The method of claim 1 , wherein the additive comprises the etchant.

9 . The method of claim 8 , wherein the etchant is operable to etch one or more of the silicon carbide semiconductor workpiece or the abrasive surface of the grinding apparatus.

10 . The method of claim 8 , wherein the etchant is a caustic compound.

11 . The method of claim 8 , wherein the etchant comprises potassium hydroxide, calcium hydroxide, or sodium hydroxide.

12 . The method of claim 1 , wherein a concentration of the additive in the fluid is in a range of 0.1% by volume to about 20% by volume.

13 . The method of claim 1 , wherein the fluid comprises a coolant.

14 . The method of claim 13 , wherein the coolant comprises deionized water.

15 . The method of claim 1 , wherein the additive is an actuatable additive, wherein the method comprises controlling an actuator to activate the actuatable additive during the grinding operation.

16 . The method of claim 15 , wherein the actuator comprises one or more of an electrostatic actuator, electrochemical actuator, acoustic actuator, ultrasonic actuator, optical actuator, thermal actuator, or plasma-based actuator.

17 . The method of claim 1 , wherein the grinding operation reduces the thickness of the silicon carbide semiconductor workpiece by about 3 microns or greater.

18 . The method of claim 1 , wherein the grinding operation reduces the thickness of the silicon carbide semiconductor workpiece by about 5 microns or greater.

19 . The method of claim 1 , wherein the grinding operation reduces the thickness of the silicon carbide semiconductor workpiece by about 20 microns or greater.

20 . The method of claim 1 , wherein the grind wheel comprises a plurality of grinding teeth arranged in an annular configuration about a center of the grind wheel, wherein there is a space between each of the grinding teeth.

21 . The method of claim 1 , wherein the additive is an actuatable additive, wherein the method comprises controlling an actuator to activate the actuatable additive during the grinding operation, and wherein the actuator comprises one or more of an electrostatic actuator, electrochemical actuator, acoustic actuator, ultrasonic actuator, thermal actuator, or plasma-based actuator.

22 . A method for grinding a silicon carbide semiconductor workpiece, comprising:

providing a surface of the silicon carbide semiconductor workpiece against a grinding apparatus, the grinding apparatus comprising a grind wheel with a plurality of grinding teeth comprising an abrasive surface, the abrasive surface comprising abrasive elements comprising one or more of diamond, ceramic, metal nitride, metal oxide, metal carbide, metalloid nitride, metalloid oxide, metalloid carbide, carbon group nitride, carbon group oxide, or carbon group carbide;

imparting relative motion between the abrasive surface and the silicon carbide semiconductor workpiece to implement a grinding operation on the silicon carbide semiconductor workpiece; and

providing a fluid to the surface of the silicon carbide semiconductor workpiece or the abrasive surface during the grinding operation;

wherein the fluid comprises an additive, the additive comprising one or more of an oxidizing agent, an etchant, a surfactant, or a lubricant,

wherein the fluid does not contain abrasive particles,

wherein the grinding operation reduces a thickness of the silicon carbide semiconductor workpiece by about 0.5 microns or greater, and

wherein (a) the grind wheel comprises a plurality of grinding teeth arranged in a concentric ring about a center of the grind wheel, wherein there is a space between each of the grinding teeth; or (b) the additive is an actuatable additive, wherein the method comprises controlling an actuator to activate the actuatable additive during the grinding operation, and wherein the actuator comprises one or more of an electrostatic actuator, electrochemical actuator, acoustic actuator, ultrasonic actuator, thermal actuator, or plasma-based actuator.

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 Aug 16, 2024
From: BUBEL, SIMON; KARUNARATNE, DINUSHA PRIYADARSHANI
To: WOLFSPEED, INC.
Reel/Frame 068307/0338 →
Continuity (1)
Related Publication 20250285873A1 · Sep 11, 2025
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