Heavy oxynitridation technology for forming highly reliable flash-type EEPROM tunnel oxide films

Author

Fukuda, Hiroshi ; Uchiyama, Asami ; Kuramochi, T. ; Hayashi, Teruaki ; Iwabuchi, T.

Author_Institution

Oki Electric Industry Co. Ltd., Tokyo, Japan

Volume

28

Issue

19

fYear

1992

Firstpage

1781

Lastpage

1783

Abstract

For the first time, it is demonstrated that in flash-type EEPROMs, the endurance properties are dramatically improved by heavy oxynitridation (RTONO) of the tunnel oxide. The layer composition evaluated by SIMS measurement indicates that large amounts of N atoms (>10²⁰ atom/cm³) pile up at the SiO₂-Si interface, and are distributed in the bulk SiO₂. In addition, the RTONO film reduces the number of hydrogen atoms, which are the origin of electron traps. This oxynitridation causes a decrease of both electron and hole traps in the tunnel oxide, resulting in an improvement of the threshold voltage narrowing.

Keywords

EPROM; circuit reliability; electron traps; hole traps; insulating thin films; integrated memory circuits; metal-insulator-semiconductor structures; nitridation; oxidation; secondary ion mass spectra; semiconductor-insulator boundaries; tunnelling; EEPROM; RTONO film; RTP; SIMS measurement; SiO₂-Si interface; SiO₂-Si₃N₄-SiO₂; electron traps; endurance properties; flash-type; hole traps; layer composition; memory devices; oxynitridation technology; rapid thermal ONO film; threshold voltage narrowing; tunnel oxide films;

fLanguage

English

Journal_Title

Electronics Letters

Publisher

iet

ISSN

0013-5194

Type

jour

DOI

10.1049/el:19921136

Filename

256094