Method of fabricating semiconductor device

摘要

A method of fabricating a semiconductor device which includes: (1) a step of forming an opening in a silicon substrate using a first silicon oxide film and a first silicon nitride film formed on the silicon substrate as masks, (2) a step of forming a second silicon oxide film and a second silicon nitride film on the side wall of the opening by the reduced pressure CVD method and anisotropic etching method, (3) a step of performing isotropic dry etching using the first and second silicon oxide films as masks, and (4) a step of performing heat treatment in an oxidizing atmosphere using the first and second silicon nitride films as masks. Thereby, uniform isotropic etching may be accomplished by use of the dry etching method.