High-crystallinity and enhanced mobility in In2O3 thin-film transistors via metal-induced method

Abstract

Meeting the advanced demands of display technology, developing oxide semiconductor thin-film transistors (TFTs) with high mobility remains a significant challenge in current research. This paper reports the fabrication of high-crystallinity In2O3 thin films and high-mobility TFT devices through low-temperature annealing using aluminum (Al) and tantalum (Ta) for induced crystallization. In the control film, partial crystallization occurs only in the central region, with grain lateral dimensions around 50 nm, resulting in a reasonable field-effect mobility of 23.9 cm2/V s for the corresponding TFTs. In contrast, metal-induced films form In2O3 grains with lateral dimensions exceeding 100 nm, along with numerous spherical crystalline particles at the metal/In2O3 interface. The well-defined front-channel structure allows the Al- and Ta-induced In2O3 TFTs to achieve high field-effect mobilities of 65.2 and 101.0 cm2/V s, respectively. Additionally, Al induction improves the subthreshold swing and threshold voltage (Vth), enhancing overall electrical performance. This study investigates the crystallization behavior of induced technology in the In2O3 system, elucidates the mechanism of metal-induced crystallization, and demonstrates that Al-induced crystallization significantly enhances the performance of metal oxide TFTs under processing temperature constraints.