Constant current tress characteristics of Ti doped Ta2O5 on silicon

Electrical behavior of Ti doped Ta₂O₅ films under constant current stress was studied. It was found that during the current flow, electrons get trapped on pre-existing traps as well as on newly generated traps. Higher current levels are more efficient in creating new traps, but less efficient in filling up the preexisting traps. The presence of Ti atoms inhibits the positive charge generation, occurring in pure Ta₂O₅ films. A simple physical model, based on Ti-induced compensation of existing oxygen vacancies in Ta₂O₅, is presented to account for the observed phenomenon.