Molecular dynamics simulation of electromigration under electric field

Abstract

A molecular dynamics simulation has been made for a nano-sized metal line on a refractory metal film by taking a local dynamic electric field into consideration. In order to consider the electric field, the local electrical conductivity in the metal line was calculated by the Cloud in Cell method. Current direction and local current density were determined from the electric field by solving Laplace equations. The forces originated from the electric field and the atomic interaction potential were applied to atoms in the simulation. The simulation showed a generation of void from the cathode and a movement of atoms to the anode followed by the formation of extrusion. This simulation method was found to be a promising one to make clear the mechanism of generation and growth of voids and the extrusion and hillock formations due to electromigration.