High-Performance InGaZnO Thin-Film Transistors Using HfLaO Gate Dielectric

Abstract—In this letter, we report a low-voltage-driven amor-phous indium–gallium–zinc oxide thin-film transistor with a high-κ-value HfLaO gate dielectric. Good characteristics were achieved including a low VT of 0.22 V, small subthreshold swing of 76 mV/dec, high mobility of 25 cm2/V · s, and large Ion/Ioff ratio of 5 × 107. These good performances are obtained at an operation voltage as low as 2 V. These characteristics are attractive for high-switching-speed and low-power applications. Index Terms—Amorphous indium–gallium–zinc oxide (a-IGZO), equivalent oxide thickness, HfLaO, high-κ, thin-film transistors. I