From 2D TCAD Model to a Physical 1D Equivalent Circuit Model for a GaN HEMT

This paper presents a physics-based one-dimensional model calibrated from two-dimensional technology computer-aided design (TCAD) simulations for AlGaN/GaN HEMT devices. The proposed model formulation is based on the integration of the Poisson equation along the transversal direction of the channel current, and assumes that the diffusion current in the continuity equation (drift-diffusion model) can be neglected. The model was implemented in a commercial circuit simulator by discretizing the Poisson and transport equations. The model is able to predict all important physical characteristics of the HEMT along its longitudinal direction, making it very useful for understanding the device operation and thus providing valuable information for the derivation of accurate equivalent circuit models. The model predictions are compared with similar TCAD simulations.