Low-temperature fabrication of Sr–N co-doped In2O3 thin film by aqueous route and its application to high performance InSrNO thin film transistor

Abstract

This work explores a strategy of Sr3+ and N3− co-doping in InSrNO thin film to simultaneously improve stability and electrical performance of In2O3 thin film transistors (TFT). The aqueous route is proposed for low-temperature (<300 °C) thin film fabrication and accurate control of dopant composition. The influences of Sr–N co-doping on the chemical and structure of the InSrNO thin films are investigated by x-ray diffraction and x-ray photo electron spectroscopy measurements. The stability of InSrNO TFTs under the bias/illumination stress has been tested. The optimized InSrNO TFT (Sr: 0.5 mol%, N: 10 mol%) exhibits both the superior electrical performance and stability (a µ of 16.38 cm2 V−1 s−1, VTH of 2.91 V, SS of 0.24 V dec−1, a ΔVTH of 1.54 V under the positive bias stress, and a ΔVTH of −1.02 V under the negative bias illumination stress). The results demonstrate that Sr–N co-doping can improve electrical performance and stability of In2O3 TFT, which is attributed to the decrease of oxygen-related defects.