Effects of In/Zn composition on the Performance of Ultra-thin Atomic Layer Deposited InxZnl-xO Channel Thin-Film Transistors

This study focuses on the fabrication of high-performance thin-film transistors (TFTs) using an atomic layer deposited (ALD) ultra-thin (4 nm) amorphous
$\text{In}_{\mathrm{X}}\text{Zn}_{1-\mathrm{X}}\mathrm{O}$
(IZO) channel. We investigated the impact of composition and annealing on the performance of TFTs with
$\text{In}_{\mathrm{x}}\text{Zn}_{1-\mathrm{x}}\mathrm{O}$
channel layers
$(\mathrm{x}=0.3,0.5,0.8$
, and
$1)$
. Among the various compositions, the TFT with
$\text{In}_{0.5}\text{Zn}_{0.5}\mathrm{O}$
channel demonstrated optimal electrical characteristics for normally-off operation and integration with complementary metal-oxide-semiconductor (CMOS) technology. These characteristics include a high mobility of 52
$\text{cm}^{2}/\mathrm{V}\cdot \mathrm{s}$
, a positive threshold voltage of 0.1 V, a low subthreshold gate swing of 83 mV/decade, and an
$\mathrm{I}_{\text{ON}}/\mathrm{I}_{\text{OFF}}$
current ratio over
$10^{9}$
.