Thin-Film Transistors With Amorphous Indium–Gallium-Oxide Bilayer Channel

Abstract

The authors report the deposition of amorphous indium–gallium-oxide (a-IGO) films on glass substrate by co-sputtering and the fabrication of thin film transistors (TFTs) with a-IGO bilayer channel. It was found that the electron mobility, $\mu _\text{FE}$ , sub-threshold swing, SS, and $\text{I}_{\text {on}}/\text{I}_{\text {off}}$ ratio of the fabricated TFTs were all better than those reported previously from the TFTs with single a-IGO channel. By properly controlling the sputtering powers, we achieved TFTs with $\mu _{\text {FE}}$ of 53.2 cm 2/Vs, SS of 0.19 V/decade and $\text{I}_{\text {on}}/\text{I}_{\text {off}}$ ratio of ~107.