ON THE PHENOMENON OF DIRECT EMISSION OF SMALL SI-N(+) (N=2, 3) CLUSTERS FROM AN AR+ BOMBARDED SI SURFACE

Very few works till now support the direct emission phenomenon for sma ll clusters (ions or neutrals) from an ion-bombarded surface, and more over, all such works present only evidences but do not actually probe into the possible processes behind such emission. Our previous work on this line evaluates the experimental conditions under which the direc t emission mechanism predominates over recombination phenomena. The ex perimental results also suggest that the concerned cluster ions are em itted ''as such'' (directly) from the ion-bombarded surface. The prese nt work is actually a follow-up of the previous work, and strengthens the above concept from a different angle. Moreover, in the light of so me very recent concepts, the possible processes leading to such emissi on are suggested. The phenomenon highlights the importance of evaporat ion effects from the impact zone at increased target current densities (J(p)).