Electrical Performance and Stability Improvement of In2O3 Thin-Film Transistors Engendered by Oxygen-Free Focused Plasma Treatment

Abstract

In the last decade, interest in solution-processed transparent oxide semiconductors has been increasing. Specifically, indium oxide (In₂O₃) films have been researched due to their processability using aqueous solutions without organic additives. However, the film quality of as-deposited layers might be suboptimal, which requires some type of post-deposition treatment. In this work, the effect of the treatment by a focused plasma (FP) under both N₂ (FP-N) and N₂:H₂ (FP-H) gases on In₂O₃ thin-film transistors (TFTs) is explored. The In₂O₃ TFTs with optimized device performance were fabricated using a volatile nitrate precursor at an annealing temperature of 250 °C. The FP-N In₂O₃ devices achieved saturation mobility (µ_sat) of 3.83 ± 0.14 cm²/Vs, and the threshold voltage was about 3 V. The FP-H devices with a µ_sat of 2.56 ± 0.15 cm²/Vs, on/off current ratio of 4.3 × 10⁶, exhibited stable electrical characteristics with improved gate bias stress stability and time-dependent environmental stability. These results demonstrate that FP treatment of solution processed In₂O₃ semiconductors effectively enhances carrier transport performance and improves bias stability.

Graphical Abstract

Han-Lin Zhao et al., Indium oxide semiconductors prepared based on solution-processes have many advantages, such as the ability to be prepared at low temperatures, but the performance of the prepared devices is poor. This work has shown that the performance of the devices can be improved by subjecting the devices to an oxygen-free focused plasma treatment for different gas