ION BEAM CRYSTALLOGRAPHY OF SURFACES AND INTERFACES

The current status of Rutherford Backscattering Spectrometry (RBS) of surfaces and interfaces is reviewed. The reader is made familiar with the use of shadowing and blocking techniques for surface crystallography and with instrumental aspects of RBS. A formal theory of shadowing and blocking is presented, along with a variety of Monte Carlo methods for computer simulation of the shadowing and blocking experiments. The atomic geometries of various relaxed and reconstructed surfaces - clean and adsorbate covered - are surveyed and the performance of RBS on these surfaces is evaluated in comparison with other techniques for structure determination, Some attention is given to RBS investigations of adsorbate geometries and surface dynamical properties. The results are discussed in the light of recent theoretical predictions of surface structure and dynamics. The review further treats in-depth analysis of thin films and interfaces, prepared under UHV conditions. Topics to be addressed are (1) the growth mode of strained heteroepitaxial films, (2) the composition and morphology of thin metal films on silicon surfaces, (3) the initial stages of silicide formation, (4) the growth of oxide films, and (5) the atomic structure of bicrystal interfaces. The use of (near)-monolayer depth resolving power is shown to be essential in most of these studies. Emphasis is placed on fundamental aspects of interface formation, but possible technological applications are briefly mentioned too.