OSCILLATIONS OF STEP VELOCITY AT SPUTTERING OF SI(111) VICINAL SURFACES BY LOW-ENERGY XE IONS

The evolution of a vicinal Si(111) surface at layer-by-layer sputterin g by low-energy Xe ion irradiation is simulated at various temperature s (500-650 degrees C) and ion fluxes (10(12)-6 x 10(12) cm(-2) s(-1)). The spatial distribution of ion-induced surface: defects was found to be responsible for the oscillations of step velocity and surface cove rage at some temperature range depending on the ion-bean flux. The per iod of oscillations is defined by the time needed for the removal of o ne monolayer. The oscillations damp out when the steady state of the s urface is reached.