Flattening of a passivated solid surface due to capillarity

We considered flattening of a nearly plane solid surface covered with a thin, inert and fully elastic passivation layer. We demonstrated that instead of relaxing to a planar state the passivated surface retains some residual roughness. We determined the kinetics of surface flattening controlled by self-diffusion along the solid-passivation layer interface. The passivation layer slows down the flattening process, if compared with the behavior of unpassivated surface. This slowing down becomes more severe with increasing passivation layer thickness.