Effects of As2 pressure on InAs heteroepitaxial growth on vicinal GaSb(001) substrate by molecular beam epitaxy
The effects of As2 pressure on the InAs heteroepitaxial growth on a vicinal GaSb substrate by solid-source molecular beam epitaxy were investigated. Transition layers with small lattice constants compared with GaSb caused by As/Sb exchange were observed at various pressures. When the As2 pressure was high, misfit dislocations were observed at the interface transition layer. As the As2 pressure decreased, misfit dislocations disappeared with the reduction in transition layer thickness, whereas pits were formed. From the result of strain analysis, dislocations were found to accompany lattice relaxation, whereas pits were formed by excess As2 pressure. By further reducing the As2 pressure, a high-quality pseudomorphic InAs layer free from dislocations and pits was obtained.