Migration into an underlying Si substrate, from CoSi2 layers which had been implanted with B ions, was studied by using a high-resolution carrier delineation technique. In the early stages of diffusion, the junction shape followed the silicide/silicon interface. By using 2-step annealing, or a thin silicide diffusion source, a laterally uniform junction was obtained with As-implanted CoSi2. The diffusion coefficients of B (table 24) could be measured by using this technique. The activation energy for B diffusion was 3.8eV.

Arsenic and Boron Diffusion in Silicon from Implanted Cobalt Silicide Layers. F.La Via, C.Spinella, E.Rimini: Semiconductor Science and Technology, 1995, 10[10], 1362-7

Table 24

Diffusivity of B in Si