In this study, the quality of thin film diode (TFD) as a switching device for active-matrix liquid-crystal-displays (AM-LCDs) was enhanced by low temperature annealing conditions with high reliability and good electrical properties. Device was composed with Ta as bottom electrode, anodic Ta2O5 as insulator layer and top electrode. Two types of material such as Ti and Cr were evaluated as a top electrode of the TFD device to optimize the symmetry of current-voltage characteristic curve, respectively. The annealing was done at low temperature conditions below 350°C. The low temperature annealing improved the TFD device with nearly perfect symmetry under high electric field.