Scalable Solution-Processed a-InZnSnO TFTs with UV-O₃-Assisted High-k GaZrO_x 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-O 3 -treated GaZrO x gate insulators annealed at different temperatures. Our results demonstrate that the treated GaZrO x 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 GaZrO x layers. Compared to devices incorporating untreated GaZrO x, the a-IZTO TFTs with treated gate dielectrics displayed markedly improved performance, including a saturation mobility (μ Sat ) of 15.69 cm 2 /V·s, a subthreshold swing of 103 mV/decade, an I ON / I OFF ratio of 10 8, 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 V DD . These enhancements are primarily attributed to the smoother interface and reduced trap states at the GaZrO x /a-IZTO interface. Our findings highlight the potential of UV/O 3 treatment with thermal annealing to enable high-performance, solution-processed GaZrO x /a-IZTO TFTs for advanced display applications.