Thin-film transistors fabricated by low-temperature process based on Ga- and Zn-free amorphous oxide semiconductor

We propose the use of indium tungsten oxide (IWO) as a channel material for thin-film transistors (TFTs). In the present study, an IWO film was deposited at room temperature by means of DC magnetron sputtering and then annealed at 100 °C in N2 prior to formation of Au source and drain electrodes. Analysis using X-ray diffraction and transmission electron microscopy revealed that the film remained amorphous even after the post-deposition annealing treatment. TFTs fabricated using a Si substrate as a back-gate electrode showed good performance, with a saturation field-effect mobility of 19.3 cm2 · V−1 · s−1, an on/off current ratio of 8.9 × 109.