High-performance full transparent tin-doped zinc oxide thin-film transistors fabricated on glass at low temperatures

High-performance full transparent bottom-gate type tin-doped zinc oxide thin-film transistors (TZO TFTs) had been successfully fabricated by RF magnetron sputtering on glass substrates at low temperatures. The effect of O₂/Ar gas flow ratio during channel deposition on the electrical properties of TZO TFTs was investigated and an optimised growing condition (O₂/Ar gas flow ratio: 8/92) for TZO film as the channel layer was acheived. Excellent device performance was obtained, with a low off-state current (I_off) of 10^-12 A, a high on/off current ratio of 5 × 10⁷, a high saturation mobility (μ_s) of 57 cm²/Vs, a steep subthreshold slope of 0.507 V/decade and a threshold voltage (V_th) of 3.5 V. These results highlight that excellent device performance can be realised in TZO film and TZO TFT is a promising candidate for transparent flat panel display.