High-performance thin film transistors based on amorphous Al–N co-doped InZnO films prepared by RF magnetron sputtering

In this study, we developed bottom-gate thin film transistors (TFTs) using a novel amorphous Al–N co-doped InZnO thin film as an active layer and determined their electrical characteristics. The film achieved high transmittance in the visible region, and X-ray diffraction pattern confirmed the thin film’s amorphous nature. Scanning electron microscopy and atom force microscopy images revealed a thin film with a smooth and uniform surface and a low root mean square roughness. X-ray photoelectron spectroscopy confirmed that oxygen vacancies in the thin film increased after annealing. Moreover, the obtained TFT showed a saturation mobility of 31.8 cm2 V−1 s−1, a threshold voltage of 7.0 V, a subthreshold swing of 0.6 V/decade, and an on/off current ratio of 9.7 × 108.