Large-Signal Modeling of GaN HEMTs using Fermi Kinetics and Commercial Hydrodynamics Transport

This work compares the current-voltage characteristics and convergence of two technology computer aided design (TCAD) solvers, a commercial hydrodynamic transport (CHT) solver, Sentaurus by Synopsys (Version R-2020.09), and the Fermi kinetics transport (FKT) solver developed at the Air Force Research Laboratory. These solvers are used to simulate and determine the convergence properties of the large-signal response of a conventional gallium nitride (GaN) high-electron mobility transistor (HEMT) at 1 GHz using drift-diffusion transport with constant electron mobility. We show that the large signal response of the HEMT is virtually the same in CHT and FKT with minor differences in their rate of convergence. This contrasts previous work in static simulations [1] where FKT had better convergence, showing that transient simulations are more computationally robust than static ones.