Titanium doped Zinc-oxide based Thin Film Transistors: Optimization of the source/drain materials

This paper aims at improving the performances of Titanium-doped Zinc-oxide (TZO) Thin-Film-Transistors (TFTs) by optimizing the source/drain materials. We successfully fabricate TZO TFTs with different source/drain materials, such as Al, Mo, Cr, Mo/Al/Mo and Cr/Al/Cr. No intentional substrate-heating is performed during each deposition step and the highest process temperature is 80°C. The results show that TFTs adopting Cr/Al/Cr as source/drain exhibit improved electrical properties with a high saturation mobility (μ_sat) of 171.4 cm²V^-1S^-1, a low subthreshold swing (SS) of 0.25 V/decade, a high I_on/I_off ratio of 2×108 and a threshold voltage (V_th) of 3.0V.