IP Library Granted Patent US 7,531,431
Granted Patent B2
US 7,531,431 · App. 11/437,934 · Granted May 12, 2009

Methods for reducing contamination of semiconductor devices and materials during wafer processing

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Quick Facts
Patent No.
US 7,531,431
App. No.
11/437,934
Granted
May 12, 2009
Kind
B2
Abstract

Methods of processing a semiconductor structure including a metal layer in the presence of organic material include flowing an aqueous mixture including an oxidizing agent over the semiconductor structure during processing of the semiconductor structure. Processing the semiconductor structure may include sawing the semiconductor structure and/or scrubbing the semiconductor structure with pressurized water. The oxidizing agent may include a peroxide, such as hydrogen peroxide, or another oxidizing agent.

Claims (48)

1. A method of operating a dicing saw including a rotary saw blade and configured to saw a semiconductor substrate, the method comprising:

flowing a mixture of water and an oxidizing agent over the semiconductor substrate, wherein the mixture further comprises a catalyst or oxidation enhancing agent; and

sawing the semiconductor substrate with the dicing saw; wherein sawing the semiconductor substrate is performed while flowing the mixture over the semiconductor substrate.

2. The method of claim 1 , wherein flowing the mixture over the semiconductor substrate comprises flowing the mixture over the semiconductor substrate at a location where the saw blade contacts the semiconductor substrate.

3. The method of claim 1 , wherein the dicing saw is configured to saw through the semiconductor substrate.

4. The method of claim 1 , wherein the dicing saw is configured to saw into, but not through, the semiconductor substrate.

5. The method of claim 1 , wherein the substrate comprises a conductive material.

6. The method of claim 5 , wherein the substrate comprises silicon carbide, silicon, gallium arsenide, germanium, aluminum and/or copper.

7. The method of claim 1 , wherein the substrate includes a metal layer thereon.

8. The method of claim 7 wherein the metal layer comprises a metal that is susceptible to ionization by an ionizing agent.

9. The method of claim 8 , wherein the metal layer comprises gold, palladium and/or platinum.

10. The method of claim 1 , wherein the oxidizing agent comprises hydrogen peroxide and the mixture comprises about 20 to about 250 ppm by volume of hydrogen peroxide.

11. The method of claim 10 , wherein the mixture comprises about 100ppm by volume of hydrogen peroxide.

12. The method of claim 1 , wherein the oxidizing agent comprises sodium peroxide, calcium peroxide, magnesium peroxide, and/or urea hydrogen peroxide.

13. The method of claim 1 , wherein the oxidizing agent comprises potassium monopersulfate, ammonium permanganate, a chlorate, ammomum iodate and/or other iodates having a concentration of about 20 to about 400 ppm by volume.

14. The method of claim 1 , wherein the oxidizing agent is included in the aqueous mixture at a concentration that produces a concentration of O − ions of between about 20 and about 250 ppm by volume.

15. The method of claim 1 , wherein the oxidizing agent comprises ozonated water having a concentration of at least about 1 ppm by volume.

16. The method of claim 1 , wherein the catalyst comprises tetraacetylethylenediamine.

17. The method of claim 1 , further comprising:

exposing the mixture to light having a wavelength of between about 254 nm and about 360 nm.

18. The method of claim 17 wherein exposing the mixture to light is performed after the mixture has been flowed over the substrate.

19. A method of processing a semiconductor structure including a metal layer in the presence of organic material, the method comprising:

flowing an aqueous mixture comprising an oxidizing agent over the semiconductor structure during processing of the semiconductor structure, wherein the mixture further comprises a catalyst or oxidation enhancing agent, wherein processing the semiconductor structure comprises sawing the semiconductor structure while flowing the mixture over the semiconductor substrate.

20. The method of claim 19 , wherein processing the semiconductor structure comprises scrubbing the semiconductor structure with pressurized water.

21. The method of claim 19 , wherein the oxidizing agent comprises peroxide.

22. The method of claim 21 , wherein the oxidizing agent comprises hydrogen peroxide.

23. The method of claim 21 , wherein the oxidizing agent comprises sodium peroxide, calcium peroxide, magnesium peroxide, and/or urea hydrogen peroxide.

24. The method of claim 19 wherein the oxidizing agent comprises potassium monopersulfate, ammonium permanganate, a chlorate, ammonium iodate and/or other iodates having a concentration of 20 to 400 ppm by volume.

25. The method of claim 19 , wherein the oxidizing agent is included in the aqueous mixture at a concentration that produces a concentration of O − ions of between about 20 and about 250 ppm by volume.

26. The method of claim 19 , wherein the oxidizing agent comprises ozonated water having a concentration of at least 2 ppm by volume.

27. A method of forming a semiconductor device, comprising:

forming a semiconductor device precursor structure on a substrate; and

separating the semiconductor device precursor from the substrate while flowing a mixture of water and an oxidizing agent over the substrate, wherein the mixture further comprises a catalyst or oxidation enhancing agent.

28. The method of claim 27 , wherein separating the semiconductor device precursor comprises sawing the substrate.

29. The method of claim 27 , further comprising:

mounting the substrate on a mounting film.

30. The method of claim 29 , wherein the mounting film comprises a flexible adhesive tape.

31. The method of claim 27 , wherein the semiconductor device precursor comprises a light emitting device precursor.

32. The method of claim 27 , wherein the substrate comprises silicon carbide, silicon, gallium arsenide, germanium, aluminum and/or copper.

33. The method of claim 27 , wherein the semiconductor device precursor comprises a metal layer.

34. The method of claim 33 , wherein the metal layer comprises gold, platinum and/or palladium.

35. The method of claim 27 , wherein the oxidizing agent comprises hydrogen peroxide and the mixture comprises about 20 to about 250 ppm by volume of hydrogen peroxide.

36. The method of claim 35 , wherein the mixture comprises about 100ppm by volume of hydrogen peroxide.

37. The method of claim 27 , wherein the oxidizing agent comprises a peroxide.

38. The method of claim 37 , wherein the oxidizing agent comprises sodium peroxide, calcium peroxide, magnesium peroxide, and/or urea hydrogen peroxide.

39. The method of claim 27 , wherein the oxidizing agent comprises potassium monopersulfate, ammonium permanganate, a chlorate, ammonium iodate and/or other iodates having a concentration of about 20 to about 400 ppm by volume.

40. The method of claim 27 , wherein the oxidizing agent is included in the aqueous mixture at a concentration that produces a concentration of O − ions of between about 20 and about 250 ppm by volume.

41. The method of claim 27 , wherein the oxidizing agent comprises ozonated water having a concentration of at least about 2 ppm by volume.

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. 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 →
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 Jun 30, 2023
From: WOLFSPEED, INC.
To: U.S. BANK TRUST COMPANY, NATIONAL ASSOCIATION
Reel/Frame 064185/0755 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jun 15, 2007
From: RAYFIELD, BARRY; JACKSON, MITCH; FANELLI, CHRIS
To: CREE, INC.
Reel/Frame 019435/0188 →