RESIDUAL RESISTIVITY DIPOLES IN ELECTROMIGRATION

In the presence of an electric field a driving force is exerted by the surrounding electron gas on the impurity atoms. The contribution from this term is usually referred to as the Bosvieux-Friedel term who related it to the residual resistivity of the impurity. It has been suggested that the residual resistivity of the impurity causes a dipolar buildup around the impurity resulting in the so-called residual resistivity dipoles (RRD's) which in turn contribute a term to the driving force, in addition to the Boxvieux-Friedel term. We discuss the nature of this term for an impurity in a jellium matrix using nonlinear screening theory. It is found to vanish if it is identified with the third order terms in the impurity potential representing contribution from the RRD's.