Investigation of zinc-tin-oxide thin-film transistors with varying SnO2 contents

Zinc tin oxide (ZTO) thin-film transistors (TFTs) were prepared on a glass substrate by deposition using radio frequency (RF) magnetron co-sputtering, followed by annealing at 300°C for 20 min. The properties of ZTO thin films were found to be dependent on the atomic compositional ratio of Zn:Sn; the device performance and operational stability of the fabricated ZTO TFTs, including the mobility, on-off current ratio, threshold voltage, and subthreshold slope, were strongly influenced by the Sn content. Better TFT performance was achieved when the Sn content in the ZTO thin film was low, and the optimal mobility was 18 cm 2 V −1 s −1 , threshold voltage was 0.5 V, and subthreshold slope was 0.227 V·dec −1 . Notably, the device performance and operational stability of the RF magnetron co-sputtered ZTO TFTs could be improved by optimizing the Zn:Sn atomic compositional ratio in the films.