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

Nanomaterials (Basel). 2023 Feb 10;13(4):694. doi: 10.3390/nano13040694.

Abstract

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 µFE of 9 cm2 V-1 s-1, a high ION/IOFF 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 (VTH) 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.

Keywords: HfO2 thin films; high-k; sol-gel; thin-film transistors (TFTs); water-driven (WD) routine.