Semiconductor manufacturing method including patterning a capacitor lower electrode by chemical etching

Abstract

Sputter etching of silicon oxide films is performed with an etching gas such as C F . Since a silicon nitride film is little etched at this time, when the etching is performed under a condition of sufficient overetching for the silicon oxide films, the silicon nitride film serves as an etching stopper, and the silicon oxide film on a platinum film and the silicon oxide film other than a portion below the platinum film are completely removed and the silicon oxide film remains only below the platinum film, to form a protrusion of a layer consisting of the silicon oxide film and the platinum film from a surface of the silicon nitride film. Thus, in patterning, a capacitor lower electrode by chemical etching, a nonuniform etching caused by temperature distribution on a substrate or among a plurality of substrates can be solved.