| abstract |
The invention provides a chemical-mechanical polishing composition comprising (a) an abrasive comprising ceria particles, (b) a cationic polymer selected from a cationic homopolymer, a cationic copolymer comprising at least one cationic monomer and at least one nonionic monomer, and a combination thereof, (c) a quaternary ammonium salt or a quaternary phosphonium salt, and (d) water, wherein the polishing composition has a pH of about 5 to about 8. The invention also provides a method of chemically-mechanically polishing a substrate, especially a substrate comprising silicon oxide, silicon nitride and/or polysilicon by contacting the substrate with the inventive chemical-mechanical polishing composition. |