Gettering of Pd and Cu by nanocavities and dislocations in Si

Previous workers have assumed that the metallic precipitates observed in the regions where nanocavities are found were the result of the metal filling the nanocavities, either as bulk metal or as a silicide phase. Recent TEM observations have demonstrated that many of these precipitates appear to be concentrated along lattice dislocations, rather than randomly distributed as would be expected for precipitates formed by the filling of nanocavities. Consequently, the gettering contribution of dislocations in the lattice that are caused by nanocavity formation must be considered. In some cases, such as that of Pd, the dislocations are the preferred sites for the bulk precipitation of metals, rather than nanocavities. Our investigations compare the results of gettering by preformed nanocavities and dislocations for Pd and Cu in order to determine which structure is the dominant influence for the formation of bulk precipitates of these metals.