Abstract:

Surfactant-mediated epitaxy allows the growth of smooth, continuous, and relaxed Ge films on Si(111). The key process is the formation of an ordered array of misfit dislocations, which are confined to the Ge/Si interface and accommodate most of the lattice mismatch of 4.2%. Its formation crucially depends on the mobility and reactivity of the dislocations, which sets a lower limit to the possible growth temperature. Below 550 °C, the mobility of the dislocations is so low that their arrangement is disordered, causing a low film quality with a high number of threading defects.