Citizen Watch Company, Ltd.

Research Development Corporation of Japan

Director-general of Agency of Industrial Science and Technology

Itsunari Hayabuchi

Fukuo Sekiya

Yutaka Hayashi

Seiichi Ishihara

Tatsuo Tsuchiya

In an MONOS type nonvolatile semiconductor memory comprising a channel forming semiconductor region between source and drain regions in a surface of a substrate; a tunnel insulating film formed on the channel forming semiconductor region in the surface of the substrate, the tunnel insulating film permitting charge-injection; a silicon nitride film formed as a second insulating film on the tunnel insulating film; a silicon oxide film formed as a third insulating film; and a conductive electrode formed on the silicon oxide film, the silicon nitride film has a composition close to a stoichiometric value of Si.sub.3 N.sub.4 at a portion near an interface with the tunnel insulating film and has a composition of excess silicon at a portion of the thickness of the same film except near the interface with the tunnel insulating film.

Nonvolatile semiconductor memory

A writable non-volatile memory circuit for use in portable electronic devices such as electronic timepiece, wherein there is improved the power consumption and there is provided a volatile memory with a serial input for writing the data into the non-volatile memory and for checking the data.

Non-volatile memory circuit for portable electronic devices

Growing community of inventors

Yokohama, Japan

Itsunari Hayabuchi