Selective etch chemistry for gate electrode materials

摘要

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.

主权项

1. A method of forming a microelectronic device comprising:
forming at least one cavity in a dielectric material layer over a semiconductor substrate; forming a gate dielectric along sidewalls and a bottom surface of said at least one cavity; depositing at least one metallic material within said at least one cavity and on said gate dielectric; and removing a portion of said at least one metallic material by an etch process employing a chemical composition, wherein said chemical composition comprises: an aqueous solution; a pH stabilizer selected from quaternary ammonium salts and quaternary ammonium alkali; and an oxidizing agent selected from peroxides and oxidants.