New experimental findings on SILC and SBD of ultra-thin gate oxides

Abstract

It is widely believed that stress-induced leakage current (SILC) and soft breakdown (SBD) of ultra-thin (tox<5 nm) gate oxides are due to trap-assisted tunneling (TAT). In this paper, through the use of carrier separation method and annealing experiments, we argue that SILC is not only contributed by trap-assisted tunneling of conduction band electrons but also by trap-assisted tunneling of valence band electrons. It is proposed in this paper that the traps are mainly donor-like.