Claims
- 1. An etching solution comprising citric acid and an oxidizing agent.
- 2. The etching solution of claim 1, wherein the oxidizing agent is hydrogen peroxide.
- 3. The etching solution of claim 1, wherein the solution has a pH of greater than about 1.0.
- 4. The etching solution of claim 1, wherein the solution has a pH of about 1.5.
- 5. The etching solution of claim 1, wherein the solution comprises about 0.5% to about 10% by weight citric acid and about 1% to about 10% by weight hydrogen peroxide.
- 6. The etching solution of claim 1, wherein the solution comprises about 4.5% to about 8% by weight citric acid and about 3% to about 5% by weight hydrogen peroxide.
- 7. The etching solution of claim 1, wherein the solution comprises about 8% by weight citric acid and about 5% by weight hydrogen peroxide.
- 8. An etching solution, comprising citric acid and hydrogen peroxide.
- 9. The etching solution of claim 8, wherein the solution has a pH of greater than about 1.0.
- 10. The etching solution of claim 8, wherein the solution has a pH of about 1.5.
- 11. The etching solution of claim 8, wherein the solution comprises about 4.5% to about 8% by weight citric acid and about 3% to about 5% by weight hydrogen peroxide.
- 12. The etching solution of claim 8, wherein the solution comprises about 8% by weight citric acid and about 5% by weight hydrogen peroxide.
- 13. A method of processing a substrate, comprising:
providing a substrate to an edge bead removal system; and applying a chemical etchant comprising citric acid and an oxidizing agent to the substrate.
- 14. The method of claim 13, further comprising rinsing the substrate with water.
- 15. The method of claim 14, further comprising spin-drying the substrate.
- 16. The method of claim 13, wherein the oxidizing agent is hydrogen peroxide.
- 17. The method of claim 13, wherein the chemical etchant has a pH of greater than about 1.0.
- 18. The method of claim 13, wherein the chemical etchant has a pH of about 1.5.
- 19. The method of claim 13, wherein the chemical etchant has a temperature of about 20° C. to about 60° C.
- 20. The method of claim 13, wherein the chemical etchant has a temperature of 55° C.
- 21. The method of claim 13, wherein the chemical etchant comprises about 0.5% to about 10% by weight citric acid and about 1% to about 10% by weight hydrogen peroxide.
- 22. The method of claim 13, wherein the chemical etchant comprises about 4.5% to about 8% by weight citric acid and about 3% to about5% by weight hydrogen peroxide.
- 23. The method of claim 13, wherein the chemical etchant comprises about 8% by weight citric acid and about 5% by weight hydrogen peroxide.
BACKGROUND OF THE INVENTION
[0001] This application claims benefit of U.S. provisional patent application Ser. No 60/212,059, filed Jun. 16, 2000, which is herein incorporated by reference.
Provisional Applications (1)
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Number |
Date |
Country |
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60212059 |
Jun 2000 |
US |