Abstract: The invention provides a chemical mechanical polishing composition for chemical mechanical polishing of a chalcogenide phase change alloy substrate. The composition comprises by weight percent, water, 0.1 to 30 colloidal silica abrasive, at least one polishing agent selected from 0.05 to 5 halogen compound, 0.05 to 5 phthalic acid, 0.05 to 5 phthalic anhydride and salts, derivatives and mixtures thereof. The chemical mechanical polishing composition has a pH of 2 to less than 7.

Abstract: The invention provides a method for chemical mechanical polishing of a substrate. The invention comprises providing a substrate, wherein the substrate comprises a chalcogenide phase change alloy and providing a chemical mechanical polishing composition, wherein the chemical mechanical polishing composition comprises, by weight percent, water, 0.1 to 30 abrasive, at least one polishing agent selected from 0.05 to 5 halogen compound, 0.05 to 5 phthalic acid, 0.05 to 5 phthalic anhydride and salts, derivatives and mixtures thereof and wherein the chemical mechanical polishing composition has a pH of 2 to less than 7. A chemical mechanical polishing pad polishes the substrate with the chemical mechanical polishing pad and the chemical mechanical polishing composition to selectively or non-selectively remove the chalcogenide phase change alloy from the substrate.