Selective etch chemistry for gate electrode materials

Abstract

A chemical solution including an aqueous solution, an oxidizing agent, and a pH stabilizer selected from quaternary ammonium salts and quaternary ammonium alkali can be employed to remove metallic materials in cavities for forming a semiconductor device. For example, metallic materials in gate cavities for forming a replacement gate structure can be removed by the chemical solution of the present disclosure with, or without, selectivity among multiple metallic materials such as work function materials. The chemical solution of the present disclosure provides different selectivity among metallic materials than known etchants in the art.

Dependencies are inferred from the claim text.