Achieving High Mobility and Excellent Stability in Amorphous In–Ga–Zn–Sn–O Thin-Film Transistors

This article reports the fabrication of high-performance amorphous indium gallium zinc tin oxide (a-IGZTO) thin-film transistors (TFTs) with superior bias stability. For comparison, amorphous indium gallium zinc oxide (a-IGZO) TFTs were also investigated to clarify the origin of the superior performance of IGZTO TFTs. It was found that the simultaneous heavy loading of In and Sn into the IGZTO system facilitated an effective mass densification, leading to a reduction in tail states and deep states. The fabricated a-IGZTO TFTs exhibited a high electron mobility (μ FE ) of 46.7 cm 2 /Vs, a subthreshold swing (SS) gate of 0.15 V/decade, and an ION/OFF ratio >1 × 10 8 . Furthermore, greater gate-bias stress stability was observed for the IGZTO TFTs compared with the IGZO TFTs.