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

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, μ
_FE
, sub-threshold swing, SS, and I
_on
/I
_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 μ
_FE
of 53.2 cm
²
/Vs, SS of 0.19 V/decade and I
_on
/I
_off
ratio of ~10
⁷
.