Hitachi, Ltd.

Mitsumasa Koyanagi

Yoshio Sakai

Hideo Sunami

Tokuo Kure

Katsuhiro Shimohigashi

Toshiaki Masuhara

Osamu Minato

Yoshifumi Kawamoto

Shinji Shimizu

Masanobu Miyao

Norikazu Hashimoto

Kikuji Sato

A semiconductor memory comprises a capacitor with a data storage portion, and an insulated-gate field-effect transistor. The capacitor is formed by a plate which is made up of the side walls and base of a groove formed in a semiconductor substrate, and by a capacitor electrode formed on the side walls and the base, over an insulation film, and which is connected electrically to the source or drain of the insulated-gate field-effect transistor. Various embodiments are provided for reducing size and preventing leakage between other memory cells, including forming stacked capacitors, forming the transistor over the capacitor, using a silicon-over-insulator arrangement for the transistor, forming a common capacitor plate and providing high impurity layers within the substrate.

Semiconductor memory

A semiconductor memory comprising a memory cell disposed on a p-type semiconductor substrate and including an insulated-gate field effect transistor and a storage capacitor. The storage capacitor comprises: an insulator capacitor including a first electrode disposed on the substrate, a film of Si.sub.3 N.sub.4 disposed on the first electrode, and a second electrode disposed on the Si.sub.3 N.sub.4 film; and a pn junction capacitor including a first n-type impurity region for constituting either the source or drain of the insulated-gate field effect transistor, and a second p-type impurity region disposed in contact with the first impurity region and having a higher impurity concentration than the substrate.

Semiconductor memory device

A semiconductor memory device consisting of a storage capacitance and an insulated gate field-effect transistor, wherein over a first conductive substance which lies in contact with a source of drain region constituting the transistor and which becomes a gate of the transistor through a first insulating film, a second conductive substance is deposited so that at least a part thereof may be stacked over the first conductive substance, and wherein a second insulating film and a third conductive substance are successively deposited on the second conductive substance, whereby the second conductive substance, the second insulating film and the third conductive substance constitute the storge capacitance.

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Cupertino, CA, United States of America

Mitsumasa Koyanagi