Investigation of the anomalous hump phenomenon in amorphous InGaZnO thin-film transistors.

• Positive charges from H 2 O molecule induced the parasitic current path, resulting in anomalous hump in subthreshold region at elevated temperature, which disappeared after N 2 annealing. • Hump still existed under PBS, while weakened hump were observed under NBS due to positive charges trapping. In this work, we investigated an anomalous hump in the bottom-gate amorphous-InGaZnO thin-film transistors. The hump in the subthreshold region appeared at elevated temperature and disappeared after N 2 atmosphere annealing. The anomalous hump phenomenon is attributed to the existence of both main current path composed by electron and parasitic current path induced by positive charges formed by adsorbed H 2 O molecules. With the increase of the testing temperature, the hump effect becomes significant since the formation of positive charges is strengthened by heat. This hump can be weakened by negative bias temperature instability stress at high temperature due to the charge-trapping mechanism. [ABSTRACT FROM AUTHOR]