Claims
- 1. A composition for polishing a composite comprised of silica and silicon nitride comprising: an aqueous medium, abrasive particles, a surfactant, an organic polymer viscosity modifier which increases the viscosity of the slurry, and a compound which complexes with said silica and silicon nitride, said compound having two or more functional groups each having a dissociable proton, said functional groups being the same or different wherein the pH of said composition is adjusted to a range wherein the removal rate of silicon nitride is effectively shut down while the removal rate of silicon dioxide is not greatly affected.
- 2. A composition according to claim 1 wherein said compound which complexes with silica and silicon nitride contains a benzene ring.
- 3. A composition according to claim 1 wherein said compound which complexes with silica and silicon nitride is a straight chain mono- or di-carboxylic acid or salt which has a secondary hydroxyl group in an alpha position relative to a carboxylate group.
- 4. A composition according to claim 1 wherein said compound which complexes with silica and silicon nitride is a tri- or poly-carboxylic acid or salt which has a secondary or tertiary hydroxyl group in an alpha position relative to a carboxlate group.
- 5. A composition according to claim 1 wherein said abrasive particles comprise ceria.
- 6. A composition according to claim 1 wherein said surfactant comprises a fluorosurfactant.
- 7. A composition according to claim 2 wherein said compound which complexes with silica and silicon nitride is potassium hydrogen phthalate.
- 8. A composition according to claim 1 comprising: water, about 0.2% to about 5% ceria, about 0.5% to about 3.5% potassium hydrogen phthalate, about 0.1% to about 0.5% fluorosurfactant, all percentages by weight, and wherein the pH of said composition is adjusted from about 6 to about 7 by the addition of a base or an amine compound to said composition.
Parent Case Info
"This application is a Continuation-in-Part of and incorporates by reference prior application Ser. No. 09/037,668 filed Mar. 10, 1998, now U.S. Pat. No. 6,042,741, a Divisional application of Ser. No. 08/802,829 filed Feb. 19, 1997 now U.S. Pat. No. 5,738,800 which claims the benefit of U.S. Provisional Application No. 60/027,277 filed Sep. 27, 1996."
US Referenced Citations (12)
Foreign Referenced Citations (3)
Number |
Date |
Country |
63-161091 |
Jul 1988 |
JPX |
7-216345 |
Aug 1995 |
JPX |
102475 |
Mar 1979 |
PLX |
Divisions (1)
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Number |
Date |
Country |
Parent |
802829 |
Feb 1997 |
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Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
037668 |
Mar 1998 |
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