Anisotropy of the surface thermodynamic properties of silicon

Three main macroscopic quantities are necessary to describe the thermodynamic properties of a crystalline surface: its surface free energy, its surface stress and its surface stiffness. Obviously, for a crystal, these quantities depend upon the crystallographic direction. We report experimental measurements of the crystalline anisotropy of all these quantities for silicon crystal. Surface free energy and surface stiffness anisotropies are deduced from a careful study of the silicon equilibrium shape, whereas the surface-stress anisotropy is deduced from artificial destabilization of crystalline Si surfaces by means of electromigration.