A lot of amorphous semiconductors have been studied for possible TFT applications, e.g., zinc oxide (ZnO) , indium zinc oxide (IZO) , zinc tin oxide (ZTO)  and indium gallium zinc oxide (IGZO) . Since Arai reported the amorphous indium zinc tin oxide (a-IZTO) with good field effect mobility in the range of ~30 cm2/Vs, it has attracted some attention to see if there exists the possibility of an alternative to a-IGZO . IZTO is a ternary oxide semiconductor which is known to exhibit good electrical conductivity, high transparency, and high mobility, making it a promising candidate for further enhancement of the performance of display technologies . In the IZTO system, both indium and tin have similar electron configurations with about the same conduction bands, which then allows electrons to move easier and faster, even in amorphous state .