Mechanism of establishment of the steady state regime of silicon sputtering by oxygen ions

The cratering rate relaxation process and the establishment of the steady state sputtering regime for silicon bombarded by oxygen ions have been investigated by a computer simulated method. It is found that in the case of primary ions incidence angle lower than αcrit the cratering rate dependence on the ion dose is nonmonotonic and can attain the negative value. In the opposite case it has a monotonic fast behaviour. The αcrit dependence on the primary ion energy is studied. The mechanism of the process proposed is concerned with the physico-chemical modification of sample subsurface layers during the initial sputtering period. The data obtained are in good agreement with the experimental results