Electromigration-Induced Flow of Islands and Voids on the Cu(001) Surface

摘要

Electromigration-induced flow of islands and voids on the Cu(001) surface isstudied at the atomic scale. The basic drift mechanisms are identified using acomplete set of energy barriers for adatom hopping on the Cu(001) surface,combined with kinetic Monte Carlo simulations. The energy barriers arecalculated by the embedded atom method, and parameterized using a simple model.The dependence of the flow on the temperature, the size of the clusters, andthe strength of the applied field is obtained. For both islands and voids it isfound that edge diffusion is the dominant mass-transport mechanism. The ratelimiting steps are identified. For both islands and voids they involvedetachment of atoms from corners into the adjacent edge. The energy barriersfor these moves are found to be in good agreement with the activation energyfor island/void drift obtained from Arrhenius analysis of the simulationresults. The relevance of the results to other FCC(001) metal surfaces andtheir experimental implications are discussed.