Nec Corporation

Sadayuki Ohnishi

Hirohito Watanabe

Koichi Ando

A stacked storage capacitor of a dynamic random access memory cell has a p-type polysilicon layer forming an upper part of an accumulating electrode, a dielectric film structure and a p-type polysilicon counter electrode, and boron difluoride is ion implanted into a non-doped polysilicon layer for the counter electrode so as to decrease leakage current density rather than a boron-implanted polysilicon counter electrode.

Process of fabricating semiconductor device having capacitor electrode

A thermal oxidation method for producing a semiconductor device having a capacitor insulating film structure capable of making a thin film having a small leakage current and small temperature dependence of the leakage current. In the insulating film, a silicon nitride film with a small electron mobility and a silicon oxide film with a small hole mobility are alternately laminated in order of the nitride film/oxide film/nitride film/oxide film from a lower electrode side. A current component such as electrons flowing in this insulating film structure is limited by the layer with the smaller mobility to reduce the leakage current. An oxide film thickness of approximately several .ANG. can thus be strictly controlled. By forming the silicon nitride film between the high dielectric oxide film and the electrode, the reaction of the silicon electrode and the high dielectric oxide film can be prevented.

Growing community of inventors

Tokyo, Japan

Sadayuki Ohnishi