STRAIN-DRIVEN SELF-ORGANIZATION OF NANOSTRUCTURES ON SEMICONDUCTOR SURFACES

Theoretical concepts and experimental results on spontaneous formation of periodically ordered nanometer-scale structures on crystal surface s are reviewed. Thermodynamic theory of the formation is considered fo r various classes of spontaneously ordered nanostructures, namely for periodically faceted surfaces, for periodic surface structures of plan ar domains, and for ordered arrays of three-dimensional coherently str ained islands. All these structures are described as equilibrium struc tures of elastic domains. Despite the fact that driving forces of the instability of a homogeneous phase are different in each case, the com mon driving force for the long-range ordering of the inhomogeneous pha se is the elastic interaction. The theory of the formation of multiple -sheet structures of islands is reviewed, which is governed by both eq uilibrium ordering and kinetically controlled ordering. For the island s of the first sheets, an equilibrium structure is formed, and for the next sheets, the structure of the surface islands meets the equilibri um under the constraint of the fixed structures of the buried islands. The experimental situation for the fabrication technology of ordered arrays of semiconductor quantum dots is analyzed where both single-she et and multiple-sheet ordered arrays are discussed.