Buried layers of CoSi2 have been successfully fabricated in (100) single crystal silicon by implanting 350 keV Co+ to doses in the range 2 - 7 × 1017 cm−2 at a temperature of ∼550°C. For doses ≥ 4 × 1017
59Co+ cm−2, a continuous buried layer of CoSi2 grows epitaxially, during implantation. After annealing (1000°C 30 minutes) continuous layers of stoichiometric CoSi2 which are coherent with the matrix are produced for doses ≥ 4 × 1017
59Co+ cm−2. For doses of ≤ 2 × 1017
59Co+, cm−2, discrete octahedral precipitates of monocrystalline CoSi2 are observed. Isochronal annealing (for 5s) at temperatures in the range 800–1200°C, shows that at temperatures ≥ 900°C there is significant redistribution of the Co from B-type or interstitial sites → substitutional A-type lattice sites. As the anneal temperature is increased there is a corresponding improvement in the crystallinity and coherency of the Si and CoSi2 lattices. This shows that at a given temperature much of the Co redistribution takes place within the first 5s of the anneal.