Achieving High Field-Effect Mobility Exceeding 90 cm2/Vs in a-IGZTO Transistors With Excellent Reliability

In this letter, amorphous indium-gallium-zinc-tin oxide (
${a}$
-IGZTO) thin-film transistors (TFTs) were characterized with a bottom gate structure, where a single target with three cation composition ratios were used to deposit the a-IGZTO channel layer. Remarkably,
${a}$
-In
$_{{0.60}}$
Ga
$_{{0.14}}$
Zn
$_{{0.20}}$
Sn
$_{{0.06}}\text{O}$
TFTs exhibited exceptional performance, featuring a significantly high field-effect mobility of 90.2 cm2/Vs, a low subthreshold swing of 0.10 V/decade, a threshold voltage (
${V} _{\text {TH}}$
) of −0.40 V, and an
${I} _{\text {ON/OFF}}$
ratio of
$3\times 10^{{8}}$
. Furthermore, the TFTs demonstrated excellent bias temperature stress (BTS) reliability, with minimal variations in
${V} _{\text {TH}}$
(
$\Delta {V}_{\text {TH}}$
) less than ±0.08 V under negative and positive bias temperature stress at 60 °C for 1 hour. The impressive performance and reliability observed in these TFTs can be attributed to the synergistic percolation of In
$^{\text {3+}}$
and Sn
$^{\text {4+}}$
and the beneficial hydrogen-doping effect near Sn cations.