Simulation of longitudinal instabilities in filamentary current flow during low-temperature impurity breakdown in semiconductors

摘要

Nonlinear semiconductor transport simulations based on the WIAS-TeSCA code are presented. Various regimes of low-temperature breakdown and current filamentation in n-GaAs are investigated using a drift-diffusion model with nonlinear generation-recombination kinetics, Nonlinear charge density waves are found in two-dimensional simulations of a point contact geometry with and without an additional perpendicular magnetic field. The numerical simulations of the nonlinear spatio-temporal dynamics are complemented by a linear stability analysis which reveals the possibility of undamped longitudinal fluctuations in the filamentary regime. (c) 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim