Patent ID: 7104869

Claim:
A method of polishing a substrate having a dielectric material with a dielectric constant of 3.5 or less disposed thereon, at least one opening in the dielectric material, a barrier material disposed over the dielectric material, and a metal conductive material disposed over the barrier material, comprising: providing the substrate to an apparatus having at least one polishing platen; polishing the metal conductive material layer to expose the barrier material; polishing the barrier material at a polishing pressure between about 0.1 and about 2 psi, wherein polishing the barrier material further comprises: applying a first polishing composition to a first polishing pad on a first polishing platen; polishing the barrier material by a first polishing technique, wherein polishing the barrier material by the first polishing technique substantially removes the bulk portion of the barrier material at a removal rate of about 200 Å/min or higher and the selectivity of the first polishing composition is at a removal rate ratio of barrier material to metal conductive material to dielectric material of about 5:1:1 or higher; applying a second polishing composition to a second polishing pad on a second polishing platen; and polishing the barrier material by a second chemical mechanical polishing technique.