AC Stress-Induced Degradation of Amorphous InGaZnO Thin Film Transistor Inverter

The degradation of amorphous indium–gallium–zinc–oxide (a-IGZO) thin film transistor (TFT) inverter operation is investigated under AC pulse stresses. From the extraction of subgap density of states (DOSs), the dominant mechanism of the pulse stress-induced degradation of driver TFT is considered as the increase of acceptor-like deep states, while that of the load TFT is attributed to the increased number of electrons trapped into the interface and/or a-IGZO thin films. We also observe that the rising and falling time of the induced pulse affects each TFT of the inverter in a different manner, and discuss the related mechanism of this phenomenon.