Patent ID: 8841216

Claim:
A method for chemical mechanical planarization of a surface having at least one feature thereon comprising a metal, said method comprising the steps of: A) placing a substrate having the surface having the at least one feature thereon comprising the metal in contact with a polishing pad; B) delivering a polishing slurry comprising: a) an abrasive ranging from 10 ppm to about 100 ppm; b) an ionic liquid compound; and c) an oxidizing agent; and C) polishing the substrate with the polishing slurry, wherein the polishing comprises polishing metal; wherein the ionic liquid compound comprises an imidazolium salt having the general molecular structure: where R 1 is selected from H, normal-alkyl, branched alkyl, alkoxy, and alkyl thioether groups; R 2 is selected from H, normal-alkyl, branched alkyl, alkoxy, and alkyl thioether groups; R 3 is selected from normal-alkyl, branched alkyl, alkoxy, alkyl thioether, cyclic and non-aromatic rings, heterocyclic non-aromatic rings and other suitable organic groups; and anion is selected from a univalent and a multivalent anion.