Effect of Annealing on Defect Elimination for High Mobility Amorphous Indium-Zinc-Tin-Oxide Thin-Film Transistor

Abstract

This letter studies the correlation of postannealing treatment on the electrical performance of amorphous In-Zn-Sn-O thin-film transistor (a-IZTO TFT). The 400 degrees C annealed a-IZTO TFT exhibits a superior performance with field-effect mobility of 39.6 cm(2)/Vs, threshold voltage (V-th) of -2.8 V, and subthreshold swing of 0.25 V/decade. Owing to the structural relaxation by 400 degrees C annealing, both trap states of a-IZTO film and the interface trap states at the a-IZTO/SiO2 interface decrease to 2.16x10(17) cm(-3)eV(-1) and 4.38x10(12) cm(-2) eV(-1), respectively. The positive bias stability of 400 degrees C annealed a-IZTO TFTs is also effectively improved with a Vth shift of 0.92 V.