Unique degradation under AC stress in high-mobility amorphous In–W–Zn–O thin-film transistors

Abstract

We report the existence of a degradation mode under AC stress in high-mobility amorphous In–W–Zn–O (IWZO) thin-film transistors (TFTs). The application of gate pulse to the IWZO-TFT reduced the on-current of the transfer characteristics, increased the subthreshold swing (SS) values, and resulted in photon emission around the source and drain electrodes of the TFT. We considered that the degradation is attributed to the breaking of the weak metal-oxygen bonds by hot carriers around the electrode edges. We expect an understanding of this degradation phenomenon to contribute to the materials design toward high-mobility and high-stability oxide semiconductors.