Patent ID: 7442645

Claim:
A method of polishing a substrate comprising: (i) contacting a substrate comprising a silicon dioxide layer and a silicon nitride layer with a chemical-mechanical polishing system comprising: (a) an inorganic abrasive, (b) a polishing additive bearing a functional group with a pK a of about 3 to about 9, wherein the polishing additive is selected from the group consisting of aniline and arylamines having one or more substituents selected from the group consisting of carboxylic acids, sulfonic acids, phosphonic acids, thiol groups, sulfonamides, salts thereof, and combinations thereof, and (c) a liquid carrier, wherein the polishing system has a pH of about 7 or less and does not contain a significant amount of cross-linked polymer abrasive particles that are electrostatically associated with the inorganic abrasive, and (ii) abrading at least a portion of the silicon dioxide layer to polish the substrate.