Effect of the gas flow rate in the focused-oxygen plasma treatment of solution-processed indium oxide thin film transistors

Abstract

In2O3 is a transparent semiconductor layer due to its transparency, high mobility, and solution processability. In this paper, we study the effect of focused oxygen plasma treatment on solution processed indium oxide films annealed at 250 °C and analyze the effect of the gas flow rate. Thin film transistor devices were prepared based on pristine In2O3 films and films treated with oxygen plasma using flow rates of 3, 6, and 9 sccm. The results show that controlling the plasma flow rate can be used to finetune the device characteristics, and the selecting the optimal flow rate is important to improve the electron mobility, threshold voltage, on/off current ratio, and the electrical stability of the devices. The In2O3 TFTs treated at 6 sccm showed the best performance with mobility of 2.19 cm2V−1s−1, threshold voltage of of 4.25 V, and on/off current ratio of 2.13 × 106. The successful fabrication of high-performance, low-temperature solution deposited indium oxide transistors using the focused oxygen plasma treatment for electrical device applications demonstrates the practical potential of this treatment method for future transparent electronics.