The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 05, 1994
Filed:
Apr. 30, 1991
Atsushi Hachisuka, Hyogo, JP;
Masao Nagatomo, Hyogo, JP;
Ikuo Ogoh, Hyogo, JP;
Hideki Genjou, Hyogo, JP;
Yoshinori Okumura, Hyogo, JP;
Takayuki Matsukawa, Hyogo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
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.