Simulation of AlGaN/GaN-HFETs including spontaneous and piezoelectric polarization charges

The influence of spontaneous and piezoelectric polarization charges on static and dynamic device characteristics of AlGaN/GaN-HFETs has been studied by numerical simulations. For the simulation a 2D-microscopic/macroscopic algorithm was used which consists of the solution of the effective mass Schrodinger equation together with the Poisson equation and a self-consistent coupling of the macroscopic transport and continuity equations. The polarization effects are included by a positive interlayer charge at the heterojunction interface, a negative surface charge and a negative interlayer charge at the AlN/GaN buffer heterojunction.