Stress control in polycrystalline thin films-reduction in adatoms diffusion into grain boundaries via surfactants

摘要

The diffusion of adatoms into grain boundaries (GBs) of polycrystalline thin film during vapor deposition affects the stress that develops and the film's subsequent performance. This Letter reports a proposed mechanism of modifying the stress by controlling adatom diffusion into GBs through the use of surfactants. Based on polycrystalline kinetic Monte Carlo simulations of Cu<111> thin films with In surfactant, the authors demonstrate that the proposed mechanism is feasible. Further, the authors show that the reduction is due to the decrease in effective adatom diffusivity, which dominates over the increase in adatom concentration.