Kinetics of growth of surface amorphous layers under irradiation of silicon with low-energy light ions

The damage buildup in Si single crystals irradiated with 10-keV Ne+ ions was studied by a method based on measurements of anisotropy in inelastic electron scattering. It is shown that disorder buildup occurs as a result of growth of an amorphous layer starting from the boundary between the native oxide and crystalline Si. It is ascertained that the growth rate of the amorphous layer is independent of the current density of ions and that a threshold dose for the defect accumulation exists. The results are explained in terms of a model based on diffusion of generated mobile point defects to the surface with their subsequent segregation; the assumption that there are saturable sinks in the as-grown single crystals is also used. The results of calculations based on this model are in good agreement with experimental data obtained both in this study and reported in available publications