Two-Dimensional Drift-Diffusion Simulation on GaN HFETs

摘要

The electron transport properties of AlGaN/GaN heterojunction field effect transistors (HFETs) were studied by two-dimensional drift-diffusion (DD) modeling method. The model performs self-consistent numerical computation on the Poisson equation, carrier statistics and current and continuity equations. The spontaneous and piezoelectircal polarization charges uniquely for GaN material was taken into account, which influences significantly the electron distribution and current density. Sliced ID Schrodinger equation along c direction was solved to obtain electron distribution. The electrical field at the 2DEG channel was found to have a peak position locates at the gate edge towards the drain side, reaching 10~6 V/cm at high bias condition. The surface potential boundary conditions also were found to have profound influence to the simulation results.