All-Water-Driven High-k HfO₂ Gate Dielectrics and Applications in Thin Film Transistors

In this article, we used a simple, non-toxic, environmentally friendly, water-driven route to fabricate the gate dielectric on the Si substrate and successfully integrate the In₂O₃/HfO₂ thin film transistor (TFT). All the electrical properties of In₂O₃ based on HfO₂ were systematically analyzed. The In₂O₃/HfO₂ device exhibits the best electrical performance at an optimized annealing temperature of 500 °C, including a high µ_FE of 9 cm² V^-1 s^-1, a high I_ON/I_OFF of 10⁵, a low threshold voltage of 1.1 V, and a low sub-threshold of 0.31 V dec^-1. Finally, test the stability of the bias under positive bias stress (PBS) and negative bias stress (NBS) with threshold shifts (V_TH) of 0.35 and 0.13 V while these optimized properties are achieved at a small operating voltage of 2 V. All experimental results demonstrate the potential application of aqueous solution technology for future low-cost, energy-efficient, large-scale, and high-performance electronics.