ABSTRACT

During the last decade, the importance of surface stress effects on crystal growth has been recognised. This paper is devoted to a review of some specific points about surface stress and epitaxial growth in order to settle some common confusion encountered in the recent literature. For this purpose, proper definitions of  surface stress and surface strain are given with a particular emphasis on thermodynamics  and numerical calculations. Such clear definitions allow to recover and justify the well-known (but still controversial) Shuttleworth equation connecting surface stress to surface energy. The various methods for measuring and calculating surface stress quantities are then described. At last, the various growth situations in which surface stress may play an important role are discussed. It is the case of two-dimensional (2D) and three-dimensional (3D) epitaxial growth where the deposited crystal is deformed before accommodation onto a lattice-mismatched substrate. In both cases the surface stress modifies the equilibrium properties, as for example the number of 2D layers at equilibrium as well as the Wulff theorem describing the equilibrium shape of 3D crystals.