Simulation of Epitaxial Growth under Ion-Beam Sputtering

Models of thin-film growth under ion-beam sputtering in a vacuum are reviewed. The direct molecular-dynamics simulation of atom flux deposition, as well as the simulation of the single-atom dynamics on the Ag/Cu(001) surface, are discussed. The component mixing effect at the film-substrate interface due to impact substitution is shown to take place for incident ion energies between 3 and 10 eV. Exchange processes are statistically studied, and their probabilities are estimated. Atomic mechanisms and the energy characteristics of surface diffusion near atomic steps are considered for the Cu/Cu(001) system. The dynamics of surface diffusion is investigated by the method of molecular statics. With step roughness taken into account, the activation barriers lower. Texture formation in a growing film under ion bombardment is analyzed in terms of the kinetic Monte Carlo model. This model allows us to explain the enhanced evolution of the axial texture at low substrate temperatures by introducing a concept of competitive growth of variously oriented grains under ion bombardment.