Characteristics of Thin-Film-Transistors Based on Zn–In–Sn–O Thin Films Prepared by Co-Sputtering System

This study presents the growth of ZITO film by co-sputtering system. By adjusting the chemical composition and electrical properties of ZITO, an amorphous ZITO (a-ZITO) matrix with a semiconducting character was used to apply in active layer for thin-film transistors (TFTs) device. The proposed a-ZITO channel layer with SiNx dielectric layer exhibited depletion mode operation. The device exhibited a subthreshold swing (SS) of 1.65 V/dec, a field-effect mobility (μFE) of 2.57 cm2 V−1 s−1, and an on/off current ratio (Ion/Ioff) of 104. The small SS and an acceptable μFE were associated with a smaller roughness and stable composition of ZITO channel layer.