Patent ID: 8637404

Claim:
The method of chemically-mechanically polishing a substrate comprising tantalum, comprising: (a) providing a substrate, (b) contacting thesubstrate with a polishing pad and a chemical-mechanical polishing composition comprising: (i) about 0.05 wt. % to about 0.75 wt. % of silica abrasive, based on the total weight of the polishing composition, (ii) about 0.5 to about 50 mmol/kg of cesium ions, based on the total weight of the polishing composition, and (iii) a liquid carrier comprising water, wherein the composition has a pH of about 8 to about 14, and wherein the composition further comprises an oxidizing agent selected from the group consisting of bromates, bromites, chlorates, chlorites, hydrogen peroxide, hypochlorites, iodates, monoperoxy sulfate, monoperoxy sulfite, monoperoxyphosphate, monoperoxyhypophosphate, monoperoxypyrophosphate, organo-halo-oxy compounds, periodates, permanganate, peroxyacetic acid, benzoquinones, naphthoquinones, anthraquinones, thionines, indigos, and mixtures thereof, (c) moving the polishing pad relative to the substrate with the chemical-mechanical polishing composition therebetween, and (d) abrading at least a portion of the tantalum from the substrate to polish the substrate.