Patent ID: 7316976
Filing Date: 2008-01-08
Classification: B24B,C09G,H01L

Abstract:
1. A method of polishing a substrate surface having thereon a metal comprising tungsten and a dielectric material, comprising: A) providing a substrate having a surface comprising tungsten and a dielectric material; B) introducing a polishing composition to the surface of the substrate, said polishing composition having a pH between about 1.5 to about 3.5 and, based on the weight of the polishing composition, comprising water and about 0.05% to about 0.8% by weight of periodic acid; C) movably applying a polishing pad over the polishing composition-covered substrate and thereby removing both tungsten and dielectric material, wherein the polishing pad exerts a pressure on the substrate, wherein the polishing composition comprises a silica abrasive, the pad comprises a silica abrasive, or both, and wherein at a 41000 Pa polishing pressure the tungsten polishing rate is between 1000 to 5000 Å/min and the tungsten/dielectric removal rate selectivity is between about 1:2 to about 2:1; and D) rinsing the polishing slurry from the substrate.