Effects of N₂O plasma treatment on the performance and stability of high indium content InGaZnO thin-film transistors

Abstract This study investigates the effects of N 2 O plasma treatment on the electrical performance and stability of In (2%) GaZnO thin-film transistors (TFTs). The experimental results show that with increasing N 2 O plasma treatment time, the electrical performance of In (2%) GaZnO TFTs deteriorated, and the threshold voltage ( V th ) is positively shifted. Moreover, the optimized In (2%) GaZnO:N 2 O (4 min) TFTs exhibited the best electrical performance, which include a μ FE of 22.5 cm 2 Vs −1 , a small SS value of 0.31 V decade −1 , a small V th of 0.3 V, a low D it value of 8.5 × 10 11 cm −2 eV −1 , and a high I on / I off of 10 7 . Moreover, a small V th shift (0.4, 0.6, −0.5 and −0.7 V) in In (2%) GaZnO:N 2 O (4 min) TFT was observed under the gate bias and light illumination test. X-ray photoelectron spectroscopy and low-frequency noise analysis indicate that this enhanced performance is attributed to the appropriate N 2 O plasma treatment that can reduce the oxygen vacancy, interface trap density, and other bulk/surface defects due to the formation of metal–nitrogen bonds (especially Ga–N) and N–O bonds. Over all, the N 2 O plasma treatment simple method has provided a novel approach to achieve high performance and highly stable oxide In (2%) GaZnO TFTs for applications in flat panel displays.