An improved sub-threshold swing model for MIT virtual source GaN model

In this paper, the derivation of sub-threshold swing in the MIT model and its relationship to punch through factor are introduced. Then, an improved model of sub-threshold swing implementing the Fermi function in punch through factor is proposed. The improved model can well characterize both the linear and saturation behavior of sub-threshold swing in medium and high drain-to-source voltage regions respectively. Benchmarking results regarding sub-threshold swing performance and its impact on drain current in sub-threshold region are presented to validate this improved model.