Impact of Source/Drain Metal Work Function on the Electrical Characteristics of Anatase TiO2-Based Thin Film Transistors

Thin film transistors (TFTs) with anatase-TiO 2 channel material deposited on an SiO 2 /Si substrate by atomic layer deposition are fabricated to investigate the effect of the source/drain (S/D) metal work function on the electrical characteristics of the TFTs. S/D materials such as aluminum, silver, and gold are selected for this study. From the measured current-voltage characteristic curves in the dark and at room temperature, it is demonstrated that the anatase TiO 2 -based TFT with Ag S/D material shows the highest on/off-current ratio (∼ 10 5 ), field effect mobility in the saturation regime ( μ sat = 5.17 cm 2 V −1 s −1 ), and saturation current (I DS,sat ∼ 0.47 mA).