Influence of implantation defects on the nucleation and growth of CoSi2 precipitates

The nucleation and growth of CoSi2 precipitates after 250 keV Co+ implantation into Si<111> with doses of 2.5 and 5x1016 cm-2 at 625 K have been investigated. For the low dose implantation the end-of-range defects act as effective centers for CoSi2 nucleation. During postannealing the preferred growth of these precipitates causes a shift of the Co profile towards the depth. At higher doses this effect is suppressed by an enhanced precipitate growth in the center of the implantation profile. Additional Si implantations with doses of (1-2)x1014 cm-2 proved the increased nucleation probability and growth of CoSi2 precipitates in regions with high defect density and offer the possibility to control actively the precipitate growth during postannealing. (orig.)