Dislocation Reduction Of Gasb On Gaas By Metalorganic Chemical Vapor Deposition With Epitaxial Lateral Overgrowth

摘要

Dislocations of GaSb on GaAs substrates stripe-patterned with SiO_2 were reduced by using epitaxial lateral overgrowth (ELO) method. The properties of ELO GaSb layers were studied by means of transmission electron microscopy (TEM) and X-ray diffraction (XRD). In the TEM image with magnification of 15,000, dislocations were not observed with ELO GaSb, while its density was estimated to be 5×10~8 cm~(-2) in seed region. Interfacial misfit arrays were formed at the openings of the mask with space of 54 A, which is close to the value expected from 7.8% lattice mismatch between GaSb and GaAs substrate. The XRD rocking curves also indicate the superior crystalline quality of ELO GaSb layers.