The invention generally provides methods and compositions for planarizing
a substrate surface having underlying dielectric materials. Aspects of
the invention provide compositions and methods using a combination of low
polishing pressures, polishing compositions, various polishing speeds,
selective polishing pads, and selective polishing temperatures, for
removing barrier materials by a chemical mechanical polishing technique
with minimal residues and minimal seam damage. Aspects of the invention
are achieved by employing a strategic multi-step process including
sequential CMP at low polishing pressure to remove the deposited barrier
materials.