Patent ID: 7723234

Claim:
A method for selectively removing polysilicon from a surface in preference to silicon dioxide and/or silicon nitride, the method comprising: a) providing a polishing slurry having a pH of from about 8 to about 11 that comprises colloidal silica abrasive particles dispersed in water and an additive compound selected from the group consisting of lysine, lysine monohydrochloride and arginine; b) disposing the polishing slurry between a polishing pad and the surface; and c) pressing the polishing pad and the surface into contact with each other while the polishing pad and surface are moving relative to each other with the polishing slurry disposed therebetween to remove polysilicon from the surface at a removal rate of 100 nm/min or greater while maintaining a selectivity ratio of polysilicon to silicon dioxide and/or of polysilicon to silicon nitride of 30 or greater.