Highly Stable Thin-Film Transistors Based on Indium Oxynitride Semiconductor

Abstract

In this study, the properties of indium oxynitride (InON) semiconductor films grown by reactive radio frequency sputtering were examined both experimentally and theoretically. Also, thin-film transistors (TFTs) incorporating InON as the active layer were evaluated for the first time. It is found that InON films exhibit high stability upon prolonged exposure to air and the corresponding TFTs are more stable when subjected to negative bias illumination stress, compared to devices based on indium oxide (In2O3) or zinc oxynitride (ZnON) semiconductors. X-ray photoelectron spectroscopy analyses of the oxygen 1s peaks suggest that as nitrogen is incorporated into In2O3 to form InON, the relative fraction of oxygen-deficient regions decreases significantly, which is most likely to occur by having the valence band maximum shifted up. Density functional theory calculations indicate that the formation energy of InN is much lower than Zn3N2, thus accounting for the higher stability of InON compared to ZnON in air.