It was found that the Cu diffusivity at between 300 and 700C could be described by:

D(cm2/s) = 4.7 x 10-3exp[-0.43(eV)/kT]

Diffusion and Solubility of Copper in Extrinsic and Intrinsic Germanium, Silicon, and Gallium Arsenide. R.N.Hall, J.H.Racette: Journal of Applied Physics, 1964, 35, 379