A method was developed for determining the surface diffusion coefficient and activation energy of Ge adatoms on (001). That is, Ge self-assembled quantum dots which were grown on a relaxed SiGe buffer-layer nucleated preferentially over a network of buried 60° dislocations. The surface sites over the buried dislocations acted as sinks for Ge adatoms. The pre-exponential term in the diffusion constant could also be determined by using Fick’s first law, and the observation that the total incident flux of Ge adatoms which impinged on the denuded zones equaled the average rate of volume increase of self-assembled quantum dots over dislocations. The diffusion of Ge adatoms on Si (001) could be described by:

D (cm2/s) = 2.53 x 10-7 exp[-0.676(eV)/kT]

at 650 to 725C.

H.J.Kim, Z.M.Zhao, J.Liu, V.Ozolins, J.Y.Chang, Y.H.Xie: Journal of Applied Physics, 2004, 95[11], 6065-71