| US 7,531,105 B2 | ||
| Polishing composition and method for high silicon nitride to silicon oxide removal rate ratios | ||
| Jeffrey M. Dysard, St. Charles, Ill. (US); and Timothy P. Johns, Naperville, Ill. (US) | ||
| Assigned to Cabot Microelectronics Corporation, Aurora, Ill. (US) | ||
| Filed on Dec. 06, 2005, as Appl. No. 11/294,853. | ||
| Application 11/294853 is a continuation in part of application No. 10/982486, filed on Nov. 05, 2004. | ||
| Prior Publication US 2006/0108326 A1, May 25, 2006 | ||
| Int. Cl. C09K 13/00 (2006.01) | ||
| U.S. Cl. 252—79.1 [438/692] | 11 Claims |
| 1. A chemical-mechanical polishing (CMP) composition suitable for polishing a substrate comprising silicon, silicon nitride,
and silicon dioxide, the composition comprising:
(a) a cationic abrasive present in the composition at about 2% by weight or less;
(b) a cationic polymer wherein the cationic polymer is a polydiallyldimethylammonium halide;
(c) an inorganic halide salt; and
(d) an aqueous carrier; the composition having a pH of less than 7.
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