It was noted that surfactant-mediated epitaxy permitted the growth of smooth continuous and relaxed Ge films on Si(111). The key process was the formation of an ordered array of misfit dislocations which was confined to the Ge/Si interface and accommodated most of the lattice mismatch of 4.2%. Its formation depended crucially upon the mobility and reactivity of the dislocations, which set a lower limit on the possible growth temperature. Below 550C, the mobility of the dislocations was so low that their arrangement was disordered; thus leading to low film quality, with a high number of threading defects.

Thermal Activation of Dislocation Array Formation. E.Janzén, I.Dumkow, M.Horn-von Hoegen: Applied Physics Letters, 2001, 79[15], 2387-9