Origin of thickness oscillations in nucleated thin-film silicides

A theory of the origin of thickness oscillations in nucleated metal silicide thin films is presented. It is shown that under certain conditions the uniformly growing state is unstable against small perturbations, and that the interface velocity oscillates periodically in time once the steady state is perturbed. These oscillations lead to the observed thickness and grain size modulations. A morphological instability can also occur, resulting in patterns of concentric rings with wavy perimeters.