A micromechanical model of surface steps

摘要

The surface of an epitaxial thin film typically consists of terraces separated by steps of atomic height and it evolves largely by the motion of steps. Steps are sources of stress that interact with other residual stress fields, and these interactions have a profound effect on surface evolution. A model of the elastic field arising from a two-dimensional step is presented as a departure form the commonly used half-plane point-multipole model. The field is calculated asymptotically for small step height up to second order in terms of 'structural' parameters that can be determined from empirical data or atomistic calculations.