High-performance zinc tin oxide thin-film transistors via hydrogen assisted metal capping structures

With the rapid development of extended reality such as augmented reality/virtual reality displays, the demand for high-mobility and low-temperature-processable thin-film transistors (TFTs) has grown significantly. Oxide semiconductors are promising candidates due to their excellent electrical and optical properties. Among them, zinc tin oxide (ZTO), an indium-free oxide semiconductor, offers advantages in material abundance and electrical performance. In this study, we demonstrate a low-temperature metal-induced crystallization (MIC) approach using aluminum (Al) capped ZTO films and investigate the role of hydrogen-assisted annealing in enhancing carrier mobility. The resulting ZTO TFTs achieved a field-effect mobility of 57.5 cm2V-1s-1 after thermal annealing and 107.3 cm2V-1s-1 with additional hydrogen annealing, both without a significant threshold voltage shift. Increasing the Al capping length promotes more extensive front-channel crystallization and enhances carrier mobility. TCAD simulations confirmed the formation of an additional high mobility current path in the crystallized front-channel region. These findings highlight the potential of combining MIC and hydrogen annealing for high-performance, thermally compatible oxide electronics. The rapid advancement of extended reality technologies has heightened the need for high-mobility, low-temperature-processable thin-film transistors. Here, the authors employ a metal-induced crystallization approach with aluminum-capped zinc tin oxide films, achieving enhanced carrier mobility through hydrogen-assisted annealing, underscoring the promise of this method for advanced oxide electronics.