A method and apparatus for polishing or planarizing a pre-metal dielectric layer by a chemical mechanical polishing process are provided. The method comprises providing a semiconductor substrate having feature definitions formed thereon, forming a pre-metal dielectric layer over the substrate, wherein the as-deposited pre-metal dielectric layer has an uneven surface topography, and planarizing the uneven surface topography of the pre-metal dielectric layer using chemical mechanical polishing techniques, wherein planarizing the uneven surface topography comprises polishing the pre-metal dielectric layer with a fixed abrasive polishing pad and a first polishing composition to remove a bulk portion of the pre-metal dielectric layer and achieve a first predetermined planarity, and polishing the pre-metal dielectric layer with a non-abrasive polishing pad and high selectivity slurry to remove a residual portion of the pre-metal dielectric and achieve a second predetermined planarity.