Reflection Electron Microscopy and Reflection Electron Diffraction in the Electron Microscope

Abstract

If the transmission electron microscope is used, not in transmission but in reflection (that is with the electron beam incident at near-grazing incidence onto the surface), images and diffraction patterns of the surface can be obtained. The results are dramatic and informative. In the images, surface steps one atom high can be clearly seen. The diffraction patterns are essentially the same as RHEED patterns except that there is better control of the illuminating conditions and camera length. Diffraction patterns can be obtained from small areas of the specimen, correlated with specific areas in the image. Similar results can be obtained at lower resolution in scanning electron microscopes. This field has been slower to develop than normal transmission microscopy but, with the development of UHV microscopes, is now advancing rapidly.