| US 7,452,481 B2 | ||
| Polishing slurry and method of reclaiming wafers | ||
| Tetsuo Suzuki, Kobe (Japan); and Satoru Takada, Foster City, Calif. (US) | ||
| Assigned to Kabushiki Kaisha Kobe Seiko Sho, Kobe-shi (Japan); and Kobe Precision Inc., Hayward, Calif. (US) | ||
| Filed on May 16, 2005, as Appl. No. 11/129,444. | ||
| Prior Publication US 2006/0255314 A1, Nov. 16, 2006 | ||
| Int. Cl. C09K 13/00 (2006.01); C09K 13/06 (2006.01); H01L 21/461 (2006.01) | ||
| U.S. Cl. 252—79.1 [252/79.4; 438/691; 438/692] | 20 Claims |
| 1. A polishing slurry having a pH of 9 to 12 and being essentially free from an organic amine, comprising:
monoclinic zirconium oxide particles having a crystallite size of 10 to 1,000 nm and an average particle diameter of 30 to
2,000 nm in an amount of 1 to 20 weight %;
at least one carboxylic acid having four or more carboxyl groups in the molecule; and
at least one quaternary alkylammonium hydroxide.
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