9.3: Control of Threshold Voltage in Back Channel Etch Type Amorphous Indium Gallium Zinc Oxide Thin Film Transistors

Tuning the process pressure at the deposition of the passivation layers has been suggested in the way of controlling the threshold voltage of a-IGZO TFTs, making it possible to employ gate driver integration. It has showed that Vth linearly changes with the pressure ΔVth/ΔPressure∼3.5V/100Pa. A 3.2 inch WVGA AMLCD with integrated gate driver circuits were successfully demonstrated using the enhancement mode BCE type bottom gate a-IGZO TFTs.