INFLUENCE OF ADSORPTION ENERGIES ON ION IMPACT DESORPTION OF SURFACE-LAYERS

In sputtering theory it is usually assumed that the sputtering yield is inversely proportional to the binding energy between the topmost atoms and the surface. A similar relation is expected to be valid for ion impact desorption of adsorbed layers. This dependence was investigated by measuring desorption cross sections for helium ions bombarding oxygen and CO adsorption layers on various metals, i.e. systems with different binding energies. The results were compared with numerical calculations. The general trend of the desorption cross sections shows the expected binding energy dependence. Deviations are discussed in terms of other parameters which are changed by using these various substrates. © 1979.