Thermal Annealing Improved Stability of Amorphous InGaZnO Thin-Film Transistors Under AC Bias Stresses

Amorphous InGaZnO (a-IGZO) thin-film transistors (TFTs) severely degrade under AC gate bias stress and AC drain bias stress, whose transfer curves respectively undergo positive shifts of 6.3 and 14.2 V after a stress time of 3000 s with a stress amplitude of 20 V. In this study, annealing at 400 degrees C in O-2 atmosphere is performed to effectively reduce the acceptor-like trap states in the a-IGZO channel and the electric field in the etching-stop layer under the extended drain electrode, which participate in dynamic and DC degradation mechanisms, respectively. Thus, a-IGZO TFTs exhibiting excellent stability without any shift of the transfer curve under the same AC gate bias stress and AC drain bias stress are experimentally demonstrated simultaneously.

Automated summary

The study demonstrates that annealing at 400 degrees C in O-2 atmosphere can effectively reduce trap states in the a-IGZO channel, improving the stability of TFTs.