Embodiments of the present disclosure generally relate to planarization of surfaces on substrates and on layers formed on substrates. More specifically, embodiments of the present disclosure relate to planarization of surfaces on substrates for advanced packaging applications, such as surfaces of polymeric material layers. In one implementation, the method includes mechanically grinding a substrate surface against a polishing surface in the presence of a grinding slurry during a first polishing process to remove a portion of a material formed on the substrate; and then chemically mechanically polishing the substrate surface against the polishing surface in the presence of a polishing slurry during a second polishing process to reduce any roughness or unevenness caused by the first polishing process.