Method for etching PT film

摘要

A method for etching a Pt film of the present invention includes the steps of: forming an etching resistant film on a Pt film, followed by patterning; etching the Pt film by using as an etching mask the etching resistant film and by using, as an etching gas, a mixed gas containing oxygen gas and chlorine gas or chloride gas, during which layers made of PtClxOy or a mixture containing PtClx and PtOy are formed on side walls of the etching resistant film and the Pt film; and removing the layers made of PtClxOy or the mixture containing PtClx and PtOy with an acid by wet etching after the etching step.