Equilibrium island ridge arrays in strained solid films

The equilibrium shape and chemical potential of an array of island ridges in an epitaxially strained solid film are determined from a continuum model describing the Stranski-Krastonow morphology of a thin layer on a substrate. This model incorporates the conditions for mechanical and chemical equilibrium, isotropic surface energy, and misfit strain. Solutions corresponding to periodic arrays of island ridges separated by wetting layers are found in the limit of island height much less than the island width. Our results describe how the island width, shape, and chemical potential vary as the distance between the ridges varies. The scaled island shape is shown to remain relatively constant as the distance between the islands increases.