Method for manufacturing a semiconductor device

Abstract

A manufacturing process which enables the opening of a downwardly protruding window for a dual damascene structure, etc. both easily and in a well-controlled fashion even in a case where the opening is small. After a depression constituted by a silicon nitride film, etc. has been configured above an interlayer insulating film, a mask is obtained by configuring a window on a portion of it in such a way that said interlayer insulating film will become bared to its bottom. Next, this mask is etched back, followed by the etching of the interlayer insulating film underneath, as a result of the interlayer insulating film becomes etched while the thickness disparity within the mask is being reflected by the corresponding attribute of the interlayer insulating film underneath, and accordingly, a downwardly protruding window (e.g., dual damascene structure, etc.) can be easily formed within said interlayer insulating film. The window which has been formed as a result of such a process is useful not only as a wire layer but also as a capacitor.