Mitsubishi Denki Kabushiki Kaisha

Hideki Genjou

Yoshinori Okumura

Atsushi Hachisuka

Masao Nagatomo

Ikuo Ogoh

Takayuki Matsukawa

A semiconductor memory device comprising memory cells having stacked capacitors has a stacked structure formed by the selective removal of a polycrystalline silicon film (15; 20) and a silicon oxide film (18a; 18), employing the same mask (14). A field effect transistor connected to a stacked capacitor has a gate electrode (20) formed of the above described polycrystalline silicon film. This polycrystalline silicon film (20) is formed on the major surface of a semiconductor substrate. The above described silicon oxide film (18) as an upper layer insulating film formed on the gate electrode (20) has a residual stress not more than 10.sup.9 dyn/cm.sup.2. No notches occur in the polycrystalline silicon film (20) in the process of selectively removing the polycrystalline silicon film (15) and the silicon oxide film (18a) deposited thereon, employing the same mask (14), thereby not decreasing the operation speed of the field effect transistor having the gate electrode (20) formed of the polycrystalline silicon film.

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Hyogo, Japan

Hideki Genjou