REAL SPACE IMAGING OF SURFACES BY MEANS OF BACKSCATTERED ELECTRONS

Abstract

Secondary electron imaging (SEI) is presented as a new method which allows the investigation of the near surface structure in real time. SEI is based on the observation that electrons backscattered from surfaces in the keV range show a strong enhancement of intensity along directions defined by atomic rows. The spatial imaging of such electrons reveals the symmetry of near surface regions in real space. Three-dimensional views of the solid are readily obtained which makes this method ideally suited for the study of any material system where there is a change of symmetry. SEI is especially useful for the investigation of surfaces with short range order, such as those with submonolayer coverages of growing films, and of quasicrystals possessing only rotational long range order.