Fundamental processes in Si/Si and Ge/Si epitaxy studied by scanning tunneling microscopy during growth

Experimental results on the epitaxy of Si and Ge on Si(0 0 1) and Si(1 1 1) surfaces, which are obtained by scanning tunneling microscopy (STM) imagin g during growth, are reviewed. Techniques for simultaneous epitaxial growth and STM measurements at high temperature are described. The ability to acc ess the evolution of the growth morphology during growth down to the atomic level enables the study of the influence of surface reconstruction on the growth. The relatively complete characterization of the growth process faci litates comparison to theoretical models and allows the identification of f undamental growth processes. For instance, the observed transition between different growth modes can be explained by specific growth processes includ ed in a model. The influence of strain on the growth morphology is reviewed for the case of heteroepitaxial growth of Ge on Si. With the method of com bining STM imaging and epitaxial growth, the transition from two-dimensiona l to three-dimensional growth as well as the evolution of size and shape of three-dimensional islands can be studied. (C) 2001 Elsevier Science B.V. A ll rights reserved.