Methods for planarizing a substrate using a combined wet etch and chemical mechanical polishing (cmp) process

Abstract

The present disclosure combines chemical mechanical polishing (CMP), wet etch and deposition processes to provide improved processes and methods for planarizing an uneven surface of a material layer deposited over a plurality of structures formed on a substrate. A CMP process is initially used to smooth the uneven surface and provide complete local planarization of the material layer above the plurality of structures. After achieving complete local planarization, a wet etch process is used to etch the material layer until a uniform recess is formed between the plurality of structures and the material layer is provided with a uniform thickness across the substrate. In some embodiments, an additional material layer may be deposited and a second CMP process may be used to planarize the additional material layer to provide the substrate with a globally planarized surface.