The diffusion of elements implanted into layers of CoSi2 (nominal thickness of 800nm), grown by metal-silicon reaction, was studied using secondary ion mass spectroscopy. It was found that B had much the highest mobility. It was totally homogenized by heat treatment (0.5h, 800C) and displayed evidence of grain-boundary diffusion at 400C and of lattice diffusion at 450C. The elements, gallium, phosphorus and germanium (used as a proxy Si tracer) diffused much less rapidly, and remained unhomogenized after annealing at 800C. The lattice diffusion of arsenic and antimony was not detectable using present means; even after heat treatment at the same relatively-high temperature. Low-temperature effects, and effects far from the implanted region, were dominated by grain-boundary diffusion. The lattice diffusion increased from boron to phosphorus and germanium; with activation energies of 2.0 and 2.7eV for boron and phosphorus, respectively.

The Diffusion of Elements Implanted in Films of Cobalt Disilicide. O.Thomas, P.Gas, A.Charai, F.K.LeGoues, A.Michel, G.Scilla, F.M.d’Heurle: Journal of Applied Physics, 1988, 64, 2973