Scalable Solution-Processed a-InZnSnO TFTs with UV-O₃-Assisted High-<i>k</i> GaZrO_<i>x</i> Gate Oxide for Low-Power Electronics

Metal-oxide thin-film transistors (MO TFTs) featuring high carrier mobility, low subthreshold swing, and excellent ON/OFF current ratios are emerging as strong contenders to conventional silicon-based TFTs for display technologies. In this study, we successfully fabricated and characterized amorphous indium zinc tin oxide (a-IZTO) TFTs using UV-O3-treated GaZrOx gate insulators annealed at different temperatures. Our results demonstrate that the treated GaZrOx films effectively suppress leakage currents and reduce surface roughness. To elucidate the underlying mechanisms, we thoroughly examined the spectroscopic, morphological, and electrical characteristics of the GaZrOx layers. Compared to devices incorporating untreated GaZrOx, the a-IZTO TFTs with treated gate dielectrics displayed markedly improved performance, including a saturation mobility (μSat) of 15.69 cm2/V·s, a subthreshold swing of 103 mV/decade, an ION/IOFF ratio of 108, zero hysteresis, and a minimal threshold voltage shift under positive bias temperature stress. Furthermore, the a-IZTO inverter exhibits a high voltage gain of 9.55 V/V at a low VDD. These enhancements are primarily attributed to the smoother interface and reduced trap states at the GaZrOx/a-IZTO interface. Our findings highlight the potential of UV/O3 treatment with thermal annealing to enable high-performance, solution-processed GaZrOx/a-IZTO TFTs for advanced display applications.