We have fabricated hafnium indium zinc-oxide (HfInZnO) thin film transistors (TFT) with indium tinoxide (ITO) interlayer. Compared with conventional HfinZnO-TFT, the electrical performance and bias stability of HfinZnO-TFTs with ITO interlayer are improved. HfinZnO-TFT with 4-nm-thick ITO interlayer shows a high mobility of 7.2 cm(2)/V s, a low threshold voltage of 0.13 V and a better bias stability. The performance enhancement is attributed to a decrease in interface trap state and an increase in carrier concentration. It suggests that introducing ITO interlayer at the ALD Al2O3/HfinZnO interface is an effective way to improve the electrical performance and bias stability. (C) 2014 Elsevier B.V. All rights reserved.