Thin film transistors based on TiO2 fabricated by using radio-frequency magnetron sputtering Original Research Article

This study demonstrates that nanocrystalline TiO2 thin films were deposited on ITO/glass substrate by radio-frequency magnetron sputtering. Field-emission scanning electron microscope (FE-SEM) and atomic force microscopic (AFM) images showed the morphology of TiO2 channel layer with grain size and root-mean-square (RMS) roughness of 15 and 5.39 nm, respectively. TiO2 thin-film transistors (TFTs) with sputter-SiO2 gate dielectric layer were also fabricated. It was found that the devices exhibited enhancement mode characteristics with the threshold voltage of 7.5 V. With 8-μm gate length, it was also found that the Ion/off ratio and off-state current were around 1.45×102 and 10 nA, respectively.