Advanced Process and Structural Strategies for High Mobility a-IGZO TFTs

Amorphous indium-gallium-zinc oxide (a-IGZO) thin-film transistors (TFTs) have emerged as a promising next-generation technology for high-resolution displays and advanced electronics. While traditional amorphous silicon (a-Si) TFTs offer low-cost and large-area processing, their limited mobility (~ 1 cm 2 /V·s) restricts fast switching applications due to challenges such as carrier trapping, poor interface quality, and environmental instability, which degrade electrical performance and long-term reliability. Conversely, polycrystalline silicon (poly-Si) TFTs provide high mobility (80–150 cm 2 /V·s) but at the expense of high production costs and complex processes. a-IGZO TFTs bridge this gap, delivering moderate mobility (5–20 cm 2 /V·s) with low-temperature processing (150–400℃) and good stability. These superior electronic properties, combined with optical transparency, make a-IGZO particularly suitable for large-scale organic light-emitting diode (OLED) backplanes and high-performance system-on-panel integration. Mobility, a critical performance factor, is influenced by defects, impurities, and process conditions. This review examines factors impacting a-IGZO mobility, compares structural and process-based enhancements for future flexible and transparent electronic applications.