Polycrystalline Indium Gallium Tin Oxide Thin-Film Transistors With High Mobility Exceeding 100 cm2/Vs

This letter reports the fabrication of high performance polycrystalline InGaSnO (IGTO) thin-film transistors (TFTs) at a low temperature of 400 °C. The microstructure of IGTO films was analyzed using X-ray diffraction and high-resolution transmission electron microscopy. The fabricated polycrystalline IGTO TFTs exhibited an unexpected high mobility of 116.5 cm
²
/Vs, threshold voltage of 0.47 V, low subthreshold gate swing of 134 mV/decade, and
${I}_{ON/OFF}$
ratio of
$> 1\times 10^{9}$
. Moreover, the stable behavior against external gate bias stress was observed for crystalline IGTO TFTs, which was attributed to the high degree of metal-oxygen lattice ordering.