Mobility Enhancement in Amorphous In-Ga-Zn-O Thin-Film Transistor by Induced Metallic in Nanoparticles and Cu Electrodes

In this work, we fabricated a high-mobility amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film transistor (TFT) based on alumina oxide (Al [Formula: see text] O [Formula: see text]) passivation layer (PVL) and copper (Cu) source/drain electrodes (S/D). The mechanism of the high mobility for a-IGZO TFT was proposed and experimentally demonstrated. The conductivity of the channel layer was significantly improved due to the formation of metallic In nanoparticles on the back channel during Al [Formula: see text] O [Formula: see text] PVL sputtering. In addition, Ar atmosphere annealing induced the Schottky contact formation between the Cu S/D and the channel layer caused by Cu diffusion. In conjunction with high conductivity channel and Schottky contact, the a-IGZO TFT based on Cu S/D and Al [Formula: see text] O [Formula: see text] PVL exhibited remarkable mobility of 33.5–220.1 cm [Formula: see text] /Vs when channel length varies from 60 to 560 [Formula: see text] m. This work presents a feasible way to implement high mobility and Cu electrodes in a-IGZO TFT, simultaneously.