Patent ID: 8883034

Claim:
A chemical-mechanical polishing composition consisting essentially of: (a) about 0.5 wt. % to about 20 wt. % of silica, (b) about 0.02 wt. % to about 5 wt. % of one or more organic carboxylic acids, (c) about 0.05 wt. % to about 2 wt. % of one or more aminophosphonic acids, (d) about 0.1 wt. % to about 5 wt. % of one or more tetraalkylammonium salts selected from the group consisting of tetraalkylammonium hydroxide, chloride, bromide, sulfate, and hydrogensulfate salts, (e) potassium bicarbonate, (f) optionally potassium hydroxide, and (g) water, wherein the polishing composition has a pH of about 8 to about 11.