The migration of Si on the (001) surface was investigated by analyzing the number density of islands which was formed during deposition. By comparing these data with the predictions of various models, it was deduced that diffusion in the fast direction (along surface dimer rows) was described by:

D (cm2/s) = 1.0 x 10-3 exp[-0.67(eV)/kT]

Y.W.Mo, J.Kleiner, M.B.Webb, M.G.Lagally: Physical Review Letters, 1991, 66[15], 1998-2001