Ab Initio Molecular Dynamics Simulation on the Aggregation of a Cu Monolayer on a WN(001) Surface

Abstract

We present a first-principles simulation study of copper aggregation on a WN(001) surface. Copper cluster formation energies and activation barriers were systematically evaluated, and the results indicate that these energies do not significantly vary with cluster size if the cluster grows two dimensionally. Moderately higher activation barriers but more favorable thermochemical energies are required for growing three dimensional clusters on the substrate. Ab initio molecular dynamics simulations were performed to examine the dynamic behavior of a copper monolayer originally commensurate with the WN substrate at several atomic layer deposition (ALD) operating temperatures as well as at room temperature. The results reveal that the copper film undergoes substantial agglomeration on the WN(001) surface at ALD operating temperatures, which is consistent with experimental observations, whereas the copper monolayer remains largely stable at room temperature.