Table of Contents
VLSI Design
Volume 13, Issue 1-4, Pages 281-285

Investigation of the Local Force Approximation in Numerical Device Simulation by Full-band Monte Carlo Simulation

Institut für Theoretische Elektrotechnik und Mikroelektronik, Universität Bremen, Kufsteiner Strasse, Postfach 33 04 40, Bremen 28334, Germany

Copyright © 2001 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The critical assumptions in the drift-diffusion model are the local force approximation and the use of the Einstein relation under nonequilibrium conditions. The validity of these two approximations is investigated by full-band Monte Carlo simulation for a SiGe-HBT. It is found that neither the local force approximation nor the Einstein relation holds. Even Einstein relations generalized with the local temperature fail under quasiballistic transport conditions, indicating that the energy transport and hydrodynamic approach are also problematic.