Patent ID: 7033409

Claim:
A method of chemical mechanical planarization of a substrate comprising a copper-containing structure, a dielectric, and a barrier layer disposed between the copper-containing structure and the dielectric, the barrier layer comprising tantalum, tantalum nitride, or both, comprising the steps of: a) providing a substrate comprising a copper-containing structure, a dielectric, and a barrier layer disposed between the copper-containing structure and the dielectric, the barrier layer comprising tantalum, tantalum nitride, or both, wherein the substrate has been chemically mechanically polished with a phase one slurry to planarize the copper; b) providing a chemical mechanical planarization composition between the substrate and a polishing pad, the composition comprising in aqueous solution, hydroxylamine nitrate, at least one nitrate which is not hydroxylamine nitrate, and at least one abrasive, wherein the chemical mechanical planarization composition is acidic; and c) planarizing said barrier layer by moving the polishing pad relative to said barrier layer while having said chemical mechanical planarization composition therebetween, wherein the planarizing step results in selective planarization of the barrier layer.