METHOD FOR PATTERNING A SUBSTARATE USING A LAYER WITH MULTIPLE MATERIALS

摘要

A method of patterning a substrate includes forming mandrels on a target layer of a substrate, the mandrels being comprised of at least two layers of material, the mandrels including a bottom layer comprised of a first material, and a top layer comprised of a second material, the target layer being comprised of a fifth material. The method includes forming sidewall spacers on sidewalls of the mandrels, the sidewall spacers comprised of a third material. The method includes depositing a fill material on the substrate that at least partially fills open spaces defined between the sidewall spacers, the fill material being comprised of a fourth material. The method includes executing a chemical-mechanical polishing step that uses the bottom layer of the mandrels as a planarization stop material layer, the chemical-mechanical polishing step removing the third material above a top surface of the bottom layer of the mandrels.