Process for fabricating a semiconductor memory device including a

Abstract

A process for fabricating a semiconductor device having a capacitor is disclosed. The process comprises the steps of: providing a semiconductor substrate having a transistor formed therein; forming an interlayer insulating film over a surface of the semiconductor substrate; forming in sequence a first polysilicon film and a first insulating film on a surface of the interlayer insulating film; selectively removing the first insulating film and the first polysilicon film to define a core made of the first insulating film and a bottom electrode made of the first polysilicon film; forming in sequence an undoped second polysilicon film and a second insulating film over the core and the bottom electrode; selectively removing the second insulating film to leave a part of the second insulating film, the part of the second insulating film serving as a cylindrical spacer which surrounds sidewalls of the core and the bottom electrode with intervention of the second polysilicon film; selectively removing a portion the second polysilicon film using the cylindrical spacer as a mask to form an undoped-polysilicon-film spacer interposed between the core and the cylindrical spacer; removing the cylindrical spacer and the core with leaving the bottom electrode and the undoped-polysilicon-film spacer; and introducing an impurity into the undoped-polysilicon-film spacer to form a cylindrical electrode, and to form a storage node electrode comprising the cylindrical electrode and the bottom electrode, the storage node electrode serves as one electrode of the capacitor.