Contrast of scanning ion microscope images compared with scanning electron microscope images for metals†

Abstract

The contrast of secondary electron images in scanning electron microscopy (SEM) is compared with that in scanning ion microscopy (SIM) for metals. The dependence of the secondary electron yield on atomic number in SEM is opposite to that in SIM. The secondary electron yields for electron bombardment increase with atomic number for metals, whereas those for ion bombardment decrease with increasing atomic number. The origin of these phenomena is discussed on the basis of the range profiles of these particles with respect to the surface.