Trapping and trap creation studies on nitrided and reoxidized-nitrided silicon dioxide films on silicon

Abstract

Alternative gate insulators for silicon-based technologies involving nitridation or reoxidation-nitridation of silicon dioxide layers are shown to be inferior to as-grown oxide in terms of charge trapping over a wide range of fields under uniform electron-injection conditions. Although nitrided layers seem to suppress trap generation more effectively than does silicon dioxide, background trapping in the as-fabricated oxynitride layers formed near their interfaces is greatly increased. The apparent reduction in trapped charges universally reported in reoxidized-nitrided oxides under high-field injection conditions is shown to be due to a decrease in occupation of these sites at fields exceeding 8 MV/cm.