An adaptive mixed scheme for energy-transport simulations of field-effect transistors

Energy-transport models are used in semiconductor simulations to account for thermal effects. The model consists of the continuity equations for the number and energy of the electrons, coupled to the Poisson equation for the electrostatic potential. The movement of the holes is modeled by drift-diffusion equations, and Shockley-Read-Hall recombination-generation processes are taken into account. The stationary equations are discretized using a mixed-hybrid finite-element method introduced by Marini and Pietra. The two-dimensional mesh is adaptively refined using an error estimator motivated by results of Hoppe and Wohlmuth. The numerical scheme is applied to the simulation of a two-dimensional double-gate MESFET and a deep submicron MOSFET device.