AbstractIn this study, we deposited zinc oxide (ZnO) thin film by atomic layer deposition (ALD) as an active channel layer in thin film transistor (TFT) using two different oxidizers, water (H2O-ALD) and oxygen radical (PA-ALD). The fabricated TFTs were annealed at various temperatures, in an oxygen ambient gas. The electrical properties of TFTs with PA-ALD ZnO film annealed at the temperature up to 400[oC] improved without any degradation of the subthreshold swing or any large shift of the threshold voltage. Through this study, we found that the high performance ZnO TFTs is possibly obtained using PA-ALD at low temperature, and the electrical properties are dependent on the annealing temperature.