Patent ID: 8623767

Claim:
A method of chemically-mechanically polishing a substrate comprising at least one layer of aluminum, titanium, or an alloy of aluminum and copper, which method comprises: (i) contacting the substrate with a polishing pad and a chemical-mechanical polishing composition consisting essentially of: (a) an abrasive consisting of alumina particles treated with an anionic polymer, wherein the anionic polymer is poly(2-acrylamido-2-methylpropane sulfonic acid) or polystyrenesulfonic acid, (b) an α-hydroxycarboxylic acid, (c) an oxidizing agent that oxidizes at least one metal, (d) about 0.01 wt. % to about 0.2 wt. % polyacrylic acid, (e) optionally, a calcium-containing compound, (f) optionally, a biocide, (g) optionally, a pH adjusting agent, and (h) water, wherein the polishing composition has a pH of about 2 to about 6, (ii) moving the polishing pad relative to the substrate with the chemical-mechanical polishing composition therebetween, and (iii) abrading at least a portion of the substrate to polish the substrate.