TCAD modelling of current dispersion in a 0.25 µm gate length GaN HEMT

Abstract

Current dispersion due to acceptor-type defects acting as electron traps are studied using 2D TCAD transient simulations. High and low drain pulse voltages are applied to study a dynamic picture of trapping and de-trapping of electrons using Drift Diffusion and Hydrodynamic transport models. In addition, Schottky electron tunnelling is employed to transient simulations in the presence of different densities of traps in the barrier to investigate how tunnelling affects the drain current at off-state.