TiO2-Based Thin Film Transistors with Amorphous and Anatase Channel Layer

In this study, TiO 2 films were deposited on FTO (fluorine-doped tin oxide)/glass substrate by radio frequency magnetron sputtering. Amorphous and anatase structure of TiO 2 were achieved without and with thermal process, respectively. Further, TiO 2 -based thin-film transistors (TFTs) with different structure were fabricated. After the electrical characteristics measurement, it was found that the amorphous TiO 2 TFTs can be operated in the enhancement mode with a threshold voltage of 3.8 V. It was also found that the field-effect mobility and on/off current of the TiO 2 TFT with amorphous channel layer were 0.087 cm 2 V −1 s −1 and 10 3 , respectively. On the other hand, the TiO 2 TFTs with anatase structure were also tested. It was found that the anatase TiO 2 TFTs have the lower threshold voltage of 2.3 V than amorphous one. Besides, it was also found that the field effect mobility and on/off current ratio of the anatase TiO 2 TFTs were both increased to 10.7 cm 2 V −1 s −1 and 10 4 , respectively. In other words, the performance of TiO 2 TFTs was related to the structure of the channel layer.