High-Performance Amorphous Zinc–Tin–Oxide Thin-Film Transistors With Low Tin Concentration

Abstract

In this paper, we present thin-film transistors (TFTs) with a zinc–tin–oxide (ZTO) layer achieved through magnetron co-sputtering. Amorphous ZTO TFTs with an Sn concentration of 2.49%, 6.95%, 7.11%, 11.95%, and 16.47% were fabricated, to investigate the effect of low-doped Sn. With a doping of 2.49% Sn, the electrical characteristics of TFTs can be obviously improved. After annealing at 440 °C, the optimal TFTs displayed a field-effect mobility of 8.71 cm2/ $\text{V}\cdot \text{s}$ , a high $\text{I}_{\mathrm{ on/off}}$ ratio of over $10^{8}$ , a subthreshold swing of 0.17 V/decade, and a turn-on voltage of −0.4 V, even with an Sn concentration of only 11.95%. Meanwhile, the shift of turn-on voltage under negative gate bias stress was only −0.4 V.