In this study, indium oxynitride (InON) semiconductor is studied by both experimental and theoretical calculations to evaluate as a channel layer for display backplane for the first time. InON thin-films were deposited by reactively RF sputtering using In metal and reactive O₂, N₂ gas. It is found that InON thin-film and the resulting thin-film transistor (TFT) have a superior air and illumination stability compared to In₂O₃ TFT and ZnON thin-films. X-ray photoelectron spectroscopy (XPS) analyses of the oxygen 1s peaks in In₂O₃ and InON suggest that as the nitrogen incorporated, the relative fraction oxygen vacancy bonds is significantly decreased by increasing valence band maxima (VBM). In addition, density functional theory (DFT) calculation revealed that the formation energy of InN is much lower than Zn₃N₂.