SIMULATION OF DEPOSITION AND DENSIFICATION IN AN ION-BEAM ENVIRONMENT

We studied the role played by the incident ion beam in ion-beam-assisted deposition by first investigating the morphology of a vapor-deposited nickel film onto an Ni(100) surface using three-dimensional molecular dynamics. Ion-beam-induced void reduction was then modeled for the case of argon ions onto a germanium film using MARLOWE. The diffusion of residual vacancies and interstitials was taken into account. The nickel films exhibited columnar ribbon-like voids and an average packing fraction of 80%. Void volume loss as a function of depth, initial void volume and beam energy was determined. Void collapse occurred at depths well beyond the incident beam range; an increase in void size at shallow depths and higher beam energies was seen. The depth of the peak void loss rate was insensitive to beam energy.