Title :
Determination of trapped oxide charge in flash-type EEPROMs with heavily oxynitrided tunnel oxide films
Author :
Fukuda, Hiroshi ; Hayashi, Teruaki ; Uchiyama, Asami ; Iwabuchi, T.
Author_Institution :
Oki Electric Industry Co. Ltd., Tokyo, Japan
fDate :
5/27/1993 12:00:00 AM
Abstract :
Flash-type EEPROMs with rapid thermal oxide (RTO) and rapid thermal oxynitrided oxide (RTONO) films are fabricated. The oxide trap density in the program and erase (P/E) cycles is determined by the shifts in I-V curves for the source-gate and drain-gate edges, respectively. The RTONO flash cell shows a drastically reduced trap density of less than 3*1012/cm2 after 104 P/E cycles. This value is one order smaller than that of the RTO flash cell. This smaller oxide trap density originates in the stable Si-N bond formation near the SiO2-Si interface, and results in lower threshold voltage shifts.
Keywords :
EPROM; electron traps; integrated memory circuits; interface electron states; rapid thermal processing; semiconductor-insulator boundaries; tunnelling; EEPROMs; I-V curves; ONO-film; RTO flash cell; RTONO flash cell; SiO 2-Si interface; SiO 2-Si 3N 4-SiO 2; erase cycle; flash-type; oxide trap density; oxide-nitride-oxide film; program cycle; rapid thermal oxide; rapid thermal oxynitrided oxide; stable Si-N bond formation; threshold voltage shifts; trapped oxide charge; tunnel oxide films;
Journal_Title :
Electronics Letters
DOI :
10.1049/el:19930631
