The interfacial reactions of thin Co films with BF2+-implanted (001) samples were studied by using cross-sectional and plan-view transmission electron microscopy, and sheet resistance measurements. Implantation-amorphized samples were found to encourage the formation of CoSi2 at 400C; and its lateral growth at higher temperatures. The residual interstitial defects in implanted samples were completely annihilated by CoSi2 formation at temperatures of between 800 and 900C. The elimination of all of the interstitial defects was attributed to the injection of a high density of the vacancies which were produced during silicide formation. Two discrete layers of F bubbles were observed in the silicides when they were annealed at temperatures of between 400 and 800C. When they were annealed at temperatures of between 800 and 900C, large bubbles were often distributed near to CoSi2 grain boundaries. It was concluded that F atoms diffused rapidly at temperatures as low as 400C, and that appreciable amounts of F were present after annealing at temperatures of between 400 and 900C.

W.Lur, L.J.Chen: Journal of Applied Physics, 1988, 64[7], 3505-11