STRAIN EFFECTS ON SI(001)

There has been considerable progress in our understanding of the steps and their configuration on the Si(001) surface. Much of this has come from the realization of the role of the intrinsic surface stress of t he reconstructed surface. LEED and STM experiments have given us infor mation about the microscopic and statistical properties of the steps o n this surface. First-principles theory has been able to calculate sur face stresses and treat the elasticity problem. From these, statistica l mechanical calculations can describe the surface step morphology. Th is paper is an overview of some of these developments.