Dependence of annealing on stability of transparent amorphous InGaZnO thin film transistor

Bottom-gate transparent IGZO–TFT had been successfully fabricated at relatively low temperature (200 °C). The devices annealing for 4 h at 200 °C exhibit good electrical properties with saturation mobility of 8.2 cm2V−1s−1, subthreshold swing of 1.0 V/dec and on/off current ratio of 5×106. The results revealed that the stability of TFT devices can be improved remarkably by post-annealing treatment. After applying positive gate bias stress of 20 V for 5000 s, the device annealing for 1 h shows a larger positive Vth shift of 4.7 V. However, the device annealing for 4 h exhibits a much smaller Vth shift of 0.04 V and more stable.