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/Vs, a high Ion/off ratio of over 108, 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.