Ion implantation of H or He into Si, followed by annealing could create a band of nanocavities. Such nanocavities could exhibit a range of interesting and often non-equilibrium interactions with defects and metals during subsequent implantation and annealing. This paper gave an overview of such interactions, concentrating on cavities produced by H-implantation. The evolution of cavities during annealing was briefly treated, followed by illustrations of the very efficient gettering ability of cavities for fast diffusing metals. For low metal concentrations introduced into the near-surface by implantation, the metal atoms decorate the cavity walls during annealing but could be displaced by O under certain conditions. At high metal concentrations, precipitation and second phase (silicide) formation could occur at cavities but silicide formation and dissolution were found to be controlled by the availability or removal of Si interstitials, leading to non-equilibrium behaviour. When Si that contains cavities was irradiated with Si ions, irradiation-induced defects interact with cavities, leading to preferential amorphization at certain temperatures. Continued irradiation leads to cavity shrinkage during bombardment, which was most efficient when the region around the cavities was amorphized.

Interaction of Defects and Metals with Nanocavities in Silicon. J.S.Williams, M.C.Ridgway, M.J.Conway, J.Wong-Leung, X.F.Zhu, M.Petravic, F.Fortuna, M.O.Ruault, H.Bernas, A.Kinomura, Y.Nakano, Y.Hayashi: Nuclear Instruments and Methods in Physics Research B, 2001, 178[1-4], 33-43