The diffusion coefficient of As in 260nm-thick polycrystalline Ni2Si layers was measured both in grains and in grain boundaries. As was implanted in Ni2Si layers prepared via the reaction between a Si layer and a Ni layer deposited by magnetron sputtering on a (100) Si substrate covered with a SiO2 film. The As concentration profiles in the samples were measured using secondary ion mass spectroscopy before and after annealing (400 to 700C). The diffusion coefficients in the grains and the grain boundaries were determined using two-dimensional finite element simulations based on the Fisher model geometry. In the case of grain boundary diffusion, the triple product of the As segregation coefficient, the grain boundary width and the diffusion coefficient was found to be given by:

sδDGB (cm3/s) = 9.0 x 10−3 exp[−3.07(eV)/kT]

I.Blum, A.Portavoce, D.Mangelinck, R.Daineche, K.Hoummada, J.L.Lábár, V.Carron, C.Perrin: Journal of Applied Physics, 2008, 104[11], 114312