Hydrodynamic hot-electron transport model with Monte Carlo-generated transport parameters

Abstract

A unique hot-electron transport model suitable for studying submicron GaAs device structures is presented. The model is based on the semiclassical “hydrodynamic” conservation equations for the average electron density, momentum, and energy. The model includes electron relaxation times, momentum relaxation times, energy relaxation times, electron temperature tensors and heat flow vectors as a function of average electron energy for the Γ, X and L valleys of GaAs. The relaxation times represent rates of exchange of electrons between valleys and rates of loss of average momentum and average energy between and within the individual valleys. The electron temperature tensor and heat flow vector depend on the electron velocity distribution about the average electron velocity and ultimately affect transport when spatial variations in average velocity and average energy exist. Transport parameters are calculated using the Monte Carlo method and the ergodic principle applied directly to the integral definitions for the parameters. Therefore, the model includes nonequilibrium transport effects such as velocity overshoot and nonuniform average electron energy. The new model should prove instrumental in optimizing electron transport through submicron structures for high-speed device applications.