Comprehensive Study on the Transport Mechanism of Amorphous Indium-Gallium-Zinc Oxide Transistors

High-performance thin-film transistors (TFTs), in which the channel material consisted of amorphous indium-gallium-zinc oxide (a-IGZO) with a bottom gate architecture, were fabricated for array applications. It was found that the dependence of the field-effect mobility on the channel length was greatly affected by the value of the contact resistance . A high contact resistance resulted in a significant drop in the normalized field-effect mobility for the short channel device , while contact-limited behavior was hardly seen for the device with a low contact resistance . The difference in the channel length dependence of the field-effect mobility was comprehensively investigated based on the conduction mechanism. The fabricated n-channel a-IGZO TFTs with exhibited a field-effect mobility of , threshold voltage of , on/off ratio of , and subthreshold gate swing of .