High-Performance Top-Gate and Self-Aligned In–Ga–Zn-O Thin-Film Transistor Using Coatable Organic Insulators Fabricated at 150 °C

We fabricated top-gate and self-aligned indium- gallium-zinc-oxide thin-film transistors (IGZO TFTs) at a maximum process temperature of 150 °C using a coatable organic gate insulator (OGI). By forming a damage and contaminationfree interface between the IGZO channel and OGI, and forming low-resistive source/drain regions by Al reaction method, we achieved good TFT properties, such as field effect mobility of 9.8 cm
²
/Vs, subthreshold swing of 0.21 V/decade, and hysteresis of 0.3 V, with minimizing a parasitic capacitance. Although the TFT showed an abnormal degradation behavior under positive gate bias stress testing in an ambient air, it was suppressed by forming an additional organic passivation layer.