Low Temperature Plasma Etching of Copper, Silver and Gold Films

摘要

Copper, silver and gold films possess unique electrical and optical properties that render them suitable for various device structures as employed in integrated circuits and plasmonic devices. Traditional etching of these metal films in halogenated plasmas is difficult due to the low vapor pressure of halogenated metal species. Reasonable etch rates of Cu, Ag, and Au films are obtained with hydrogen-based plasmas. Pattern formation with hydrogen and methane plasmas yields excellent selectivity to barrier materials such as Ta and Ti and generates metal wall slopes of ～80°.