Instability of Indium Zinc Oxide Thin-Film Transistors Under Transmission

The instability of indium zinc oxide thin film transistors (IZO TFTs) is investigated under transmission line pulsed (TLP) stress by applying repeated voltage pulses with different durations (50-200 ns) to the gate with grounded source and drain. Threshold voltage increases and then electron field effect mobility decreases after TLP stress. These results are due to electron trapping in the existing traps of gate oxide near the SiO2/IZO interface, which is verified by the subsequent annealing experiment. The instability behavior is also investigated by low- frequency noise measurements before and after TLP stress. Furthermore, influences of stress voltage and pulsewidth on the degradation effect of IZO TFT are discussed.