Analytical Current and Capacitance Models for Amorphous Indium-Gallium-Zinc-Oxide Thin-Film Transistors

We propose analytical current and capacitance models for amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film transistors (TFTs) for the simulation of a-IGZO TFT-based-circuits. The proposed models are composed of physical parameters including the subgap density of states and confirmed by comparing the calculated current-voltage and capacitance-voltage characteristics with measured ones. The proposed models are expected to be useful for the optimization of fabrication processes and for the prospective estimation of the effect of process conditions on the circuit performances. Through the circuit simulation implemented with the proposed models, we verify that the proposed analytical model and simulation methodology can be applicable to the expectation of the complicated circuit behaviors. The simulation framework with proposed analytical models is expected to be a powerful tool in the optimization process and circuit design with amorphous oxide semiconductor TFTs including a-IGZO TFTs.