High-Mobility IGZO TFTs by Infrared Radiation Activated Low-Temperature Solution Process

Abstract

This letter presents high-mobility thin-film transistors (TFTs) based on InGaZnO by a novel infrared (IR) radiation activated low-temperature solution process. A high mobility of over 60 cm2V−1s−1, an ${I}_{\mathrm{\scriptscriptstyle ON}}/{I}_{\mathrm{\scriptscriptstyle OFF}}$ ratio of 106, and a decreased operating voltage of 4 V were achieved at 230 °C. This mobility was four times higher than that of a device by high-temperature (450 °C) annealing, and was comparable to those of oxide TFTs previously produced via vacuum or high-temperature processes. The synergistic IR radiation and thermal energy mechanism resulted in more effective removal of precursor impurities, a more extensive metal-oxygen lattice, and more oxygen vacancies to serve as charge carriers, which contributed to the much higher performance achieved with IR radiation. Moreover, the IR-processed devices exhibited excellent operational stability with a small ${V}_{\textsf {th}}$ shift under bias stress. Our results may provide new low-temperature solution routes to high-performance TFTs.