Improved Electrical Performance of SiO₂-Doped Indium Zinc Oxide Thin-Film Transistor.

In this study, we investigated the effect of oxygen content on the stability and the role of silicon in amorphous SiO₂-doped indium-zinc-oxide thin film transistor. The SiO₂-doped IZO (SIZO) thinfilms were deposited at room temperature by radio-frequency magnetron co-sputtering. To optimize stability and electrical performance, we changed the amount of oxygen by changing oxygen gas ratio in reactive sputtering (11%, 12%, and 13%) and used SiO₂ target to deposit SIZO active layer. By adjusting the parameters of SIZO thin-film transistor (TFT) preparation, we found that the best performance was obtained when the oxygen ratio of a-SIZO films was 11%. The optimized a-SIZO TFT exhibited an on/off current ratio (/) of 2.1×10, saturation mobility () of 53.6 cm²/V . s, threshold voltage () of -7.3 V, and subthreshold swing (S.S.) of 1.7 V/decade. Compared to a-IZO films, the a-SIZO film showed better stability and electrical performance because it had fewer oxygen vacancies and defects.