The lattice diffusion of boron implanted into cobalt disilicide was studied. The bulk CoSi2 substrate, prepared by solidification from the melt, had grain sizes in the mm range; thus minimizing interference from grain boundary diffusion. Boron was introduced into the CoSi2 substrate by ion implantation and, after heat treatments ranging from 450 to 700C, the boron distribution was monitored by secondary ion mass spectrometry. The diffusion coefficient was deduced from the shape of the resultant boron profile by means of numerical fitting, where the actual shape of the as-implanted profile was taken into account. An activation energy of 2.1eV was found for the lattice diffusion of boron in CoSi2, and the lattice diffusion coefficient could be represented by:

D(cm2/s) = 9 x 10-1exp[-2.1/kT]

Lattice Diffusion of Boron in Bulk Cobalt Disilicide. C.Zaring, P.Gas, B.G.Svensson, M.Östling, H.J.Whitlow: Thin Solid Films, 1990, 193-194[1], 244-7