EFFECT OF IN SITU THERMAL ANNEALING ON CRYSTALLINE QUALITY OF Ge LAYERS GROWN BY MOLECULAR BEAM EPITAXY ON Si (100).

Recent studies have shown that the crystalline quality of the Ge layers grown on Si substrates by molecular beam epitaxy (MBE) can be improved by thermal annealing during their deposition. In order to investigate the effect of the thermal annealing, the Ge/Si interfaces of samples grown under a variety of conditions have been studied with transmission electron microscopy (TEM). The TEM results revealed that the relaxation process of the lattice mismatch between the Ge and the Si was not straightforward. The dislocations generated during the Ge deposition were irregularly distributed in the Ge layer, and were changed into a regular array of misfit dislocations lying on the Ge/Si interface by the thermal annealing.