Renesas Electronics Corporation

Hitachi-kokusai Electric Inc.

Yoshiki Yonamoto

Hirotaka Hamamura

Tadashi Terasaki

Katsuhiko Yamamoto

A technique capable of improving the memory retention characteristics of a non-volatile memory is provided. In particular, a technique of fabricating a non-volatile semiconductor memory device is provided capable of enhancing the film quality of a silicon oxide film even when a silicon oxide film as a first potential barrier film is formed with a plasma oxidation method to improve the memory retention characteristics of the non-volatile memory. After a silicon oxide film, which is a main component of a first potential barrier film, is formed with a plasma oxidation method, plasma nitridation at a high temperature and a heat treatment in an atmosphere containing nitric oxide are performed in combination, thereby forming a silicon oxynitride film on the surface of the silicon oxide film, and segregating nitrogen to an interface between the silicon oxide film and a semiconductor substrate.

Method of fabricating non-volatile semiconductor memory device by using plasma film-forming method and plasma nitridation

The charge retention characteristics of a non-volatile memory, particularly, a MONOS-type non-volatile memory is improved. In a non-volatile memory cell including a tunnel silicon oxide film (), a silicon nitride film () serving as a charge storage film, a silicon oxide film (), and a gate electrode () which are sequentially formed on a semiconductor substrate, the tunnel silicon oxide film () has a stacked structure of a silicon oxynitride film () and a silicon oxide film (). Herein, it is configured such that a density of nitrogen atoms contained in the silicon oxynitride film () decreases as a distance from an interface with the semiconductor substrate increases in a film-thickness direction of the silicon oxynitride film ().

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Oyama, Japan

Yoshiki Yonamoto