Effect of Oxygen Partial Pressure on Electrical Characteristics of Amorphous Zinc-Tin-Oxide Thin-Film Transistors

Abstract

We fabricated and studied the electrical characteristics of thin-film transistors with an amorphous zinc-tin–oxide (a-ZTO) channel, which was deposited by radio frequency magnetron co-sputtering under different oxygen partial pressures. The effect of varying the oxygen concentration on the electrical properties and device performance of the a-ZTO TFTs was investigated. A positive shift observed in the threshold voltage with increasing oxygen suggests that the number of oxygen vacancies in the a-ZTO film decreased. With an oxygen flow rate of 4 %, a threshold voltage of 2.25 V, an on-off current ratio of 2.1 × 103, and a subthreshold slope of 0.8 V·dec−1were obtained.