A Complete Charge-Based Capacitance Model for IGZO TFTs

Abstract

We present a new complete capacitance model for the amorphous indium-gallium-zinc-oxide (IGZO) thin-film-transistor (TFT), valid in the above-threshold and subthreshold regime (Fermi level in the tail and deep states, respectively). The parameters applied in the model are analytically extracted from the current-voltage characteristics of the devices, using a previously developed unified model and parameter extraction method. The good agreement between our capacitance model and 3D numerical TCAD simulations proves the validity of this letter, which is expected to be useful for the optimization of fabrication processes and for the prospective estimation of the effect of process conditions on circuit performances.