Nucleation, growth and size distributions of Ge islands on Si(001): in-situ STM studies

摘要

Heteroepitaxial Ge/Si(001) growth has been investigated using in-situ scanning tunneling microscopy. Once the mismatch strain exceeds a critical value it is relieved either by the formation of coherent three-dimensional islands or pits, depending upon growth parameters. The kinetics of island growth have been measured in-situ to yield a power-law dependence of growth rate. Although late-stage island growth is often attributed to Ostwald ripening, in the case of Ge/Si(001), due to the energy barrier at the island base, other growth mechanisms are found to dominate at temperatures below 700 K.