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

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 (In
₂
O
₃
) at the different irradiation times together with annealing at high temperature is explored. The results showed that the developed In
₂
O
₃
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 In
₂
O
₃
TFTs and can be used for the fabrication of cost-effective, low-temperature, and reliable electronic devices.