Growth modes in homo- and heteroepitaxial growth

Abstract

Due to scientific and technological interest many studies are concerned with growth modes for the first monolayers of epitaxial growth. By combination of microscopy (like STM) and diffraction (like spot profile analysis of LEED) the important steps of film formation via deposition, migration, nucleation and film completion are studied. Temperature, deposition rate and defects of substrate and of the growing film influence drasticly the growth modes in homoepitaxial systems of metals and semiconductors. For heteroepitaxial growth the misfit has to be accommodated during growth. For different systems the processes are quite different. For metals on metals the film is more or less floating where only the orientation is provided by the substrate. For metals on semiconductors some influence on the lattice constant is seen, which depends on the temperature of deposition. For semiconductors on semiconductors a one-to-one correspondence of film atoms to substrate atoms requires a clear transition from pseudomorphic to relaxed growth of the film by dislocations at the interface. The wide variety of growth modes may be well distinguished by a careful analysis of diffraction spot profiles, which should be recorded during deposition with varying scattering conditions.