Study of Ti addition in channel layers for In–Zn–O thin film transistors

Ti added In–Zn–O thin films and their application to thin film transistors were studied. The In–Zn–O films were deposited by pulsed plasma deposition using targets with various Ti contents added. High content of Ti in In–Zn–O films was found to induce a decrease in carrier concentration. The effect was attributed to suppression of oxygen vacancies by Ti incorporation. For thin film transistors with Ti added In–Zn–O as channel layer materials, threshold voltage showed positive shift as Ti content increases and field effect mobility was not decreased at the same time. Results of a bias stress experiment on device fabricated at room temperature are also given.