抄録
Surfaces of KCl crystals irradiated uniformly by scanning of 5 keV beam of electrons collimated with one direction are observed by an atomic force microscope (AFM). The irradiation doses are in the range up to 1016 cm-2. The surfaces remain many overlapped terraces of sub-micron with random orientations. They are hard to be associated with the square pits observed in well known layer by layer desorption measurements in the dose range of 1014 cm-2. The desorption process is simulated by a model based on the assumption that the low-coordinated sites act as the precursors for desorption. We have introduced parameters into this model to reproduce the oscillating structure of the particle-yields of the layer by layer desorption. The resulting final morphology in the dose range of 1016 cm-2 shows that many overlapped terraces are created with random orientations, whose terrace-lengths are small compared with that observed. The morphologies show that the process assumed to reproduce the layer by layer desorption can lead the multi-layer steps on the surface.
