A Physically Based Compact Model for IGZO Transistors

A thin film transistor (TFT) model applicable to circuit design is presented. The model is based on a general solution of the vertical 1-D Poisson equation, valid for asymmetric and independent top and bottom gates and for doped semiconductor films, with no restrictive approximations. The solution is necessarily numerical, but we describe a discretization strategy on a reduced and highly nonuniform grid, resulting in a computationally efficient model. The resulting long-channel model is complemented with empirical short-channel effect corrections. The model results are validated against measured c-axis aligned crystalline indium-gallium-zinc oxide (CAAC-IGZO) MOSFET data.