Effect of O2 plasma treatment on density-of-states in a-IGZO thin film transistors

This work reports an efficient route for enhancing the performance of amorphous InGaZnO (a-IGZO) thin film transistors (TFT). The mobility was greatly improved by about 38% by means of O-2 plasma treatment. Temperature-stress was carried out to investigate the stability and extract the parameters related to activation energy (E (a)) and density-of-states (DOS). The DOS was calculated on the basis of the experimentally obtained E (a), which can explain the experimental observation. A lower activation energy (E (a), similar to 0.72 eV) and a smaller DOS were obtained in the O-2 plasma treatment TFT based on the temperature-dependent transfer curves. The results showed that temperature stability and electrical properties enhancements in a-IGZO thin film transistors were attributed to the smaller DOS.