Performance Enhancement of Solution‐Derived Zinc–Tin–Oxide Thin Film Transistors by Low‐Temperature Microwave Irradiation

In this work, high-performance solution-derived zinc–tin–oxide (ZTO) thin-film transistors (TFTs) are developed by employing low-temperature microwave irradiation (MWI) for post-deposition annealing (PDA). The MWI-treated ZTO TFTs exhibit electrical properties superior to those of the ZTO TFTs treated using conventional thermal annealing despite the relatively lower temperature and shorter processing time. A large drain current on/off ratio of 1.7 × 108, small hysteresis of 0.96 V, steep subthreshold swing of 194 mV/dec, and high field-effect mobility of 13.6 cm2 V −1 s−1 were obtained from the MWI-treated TFTs. In addition, the instability of the solution-derived ZTO TFTs is significantly reduced by MWI treatment. We also analyze the ZTO films before and after PDA using X-ray photoelectron spectroscopy to determine the dependences of the electrical properties and instability on the chemical bonding and defect structures.