High Mobility Bilayer Metal–Oxide Thin Film Transistors Using Titanium-Doped InGaZnO

We report a high performance indium-gallium-zinc oxide (IGZO)/IGZO:Ti bilayer metal–oxide thin-film transistor (TFT) with a low drive voltage of ${<}{\rm 2}~{\rm V}$. Compared with conventional IGZO TFTs, the novel bilayer metal–oxide TFTs through IGZO thickness modulation can reach the lowest off current of $1.6\times 10^{-11}~{\rm A}$, smallest sub-threshold swing of 73 mV/decade, and highest mobility of 63 ${\rm cm}^{2}$/Vs, which may create the potential application for high resolution display.