Modeling electromigration as a fluid-gas system

In this paper two problems in modeling electromigration are addressed. The first problem is an issue of principle concerning counting the number of va riables and the number of equations for formulating a well-posed mathematic al problem. The second problem deals with setting up a system of equations which are sufficiently detailed for performing computer simulations of the local dynamics governing electromigration phenomena, and which also keep th e CPU consumption within acceptable limits. A model for electromigration, w hich is based on a fluid-gas picture for the material transport, is propose d for dealing with bath questions. The flow of matter is described as a com bined flow of lattice sites and a flow of vacancies. The gas component is u sed to describe the vacancy flux. (C) 1999 Elsevier Science Ltd. All rights reserved.