Improved Electrical Performance of In₂O₃ Thin-Film Transistor by UV/Ozone Treatment

Abstract

In this work, the effect of a UV/ozone source composed of two monochromatic wavelengths of 184 nm and 254 nm irradiated upon the indium oxide film (In2O3) at the different irradiation times together with annealing at high temperature is explored. The results showed that the developed In2O3 thin-film transistors (TFTs) exposed to UV/ozone for the 40 s and annealed at 250 °C for 2 h exhibited a significantly high performance, i.e., saturation mobility of 6.1 ± 0.2 cm $^{2}/$ Vs, $\text{I}_{\mathrm{ on}}/\text{I}_{\mathrm{ off}}$ ratio of $1.4\times10$ 7, low threshold voltage (1.5 ± 0.9 V), and a small subthreshold swing (0.25 V/dec). The in-depth analysis of the developed devices through electrical characteristics, surface morphology, and practical aspect of inverter function confirm that UV/ozone irradiation improves the surface trap density, thereby increasing the mobility, and eventually improves the gate-bias stress stability and time-dependent environmental stability. The current work supports the fact that UV/ozone can improve the electrical properties of In2O3 TFTs and can be used for the fabrication of cost-effective, low-temperature, and reliable electronic devices.

Keywords

• In₂O₃ TFTs
• solution process
• UV/ozone
• gate bias stress stability
• C-V measurement