Highly-selective metal etchants

摘要

A highly selective metal wet etchant with an active ingredient comprising one or more types of molecules having two or more oxygen atoms is described. In one embodiment, the wet etchant is utilized to pattern a metal layer in a semiconductor structure. In another embodiment, a highly selective metal wet etchant with an active ingredient comprising one or more types of molecules having two or more oxygen atoms is used to pattern a metal gate electrode in a replacement gate processing scheme.