Material Properties of Low Defect Al0.6Ga0.4Sb Layers grown on Si Substrates

Abstract

The extreme difficulties have been reported to directly grow InAs and AlSb material systems on silicon substrate because of large lattice mismatch greater than 12% as well as the anti-phase domain caused by polar-non-polar transition, leading to the production of deleterious defects, primarily high densities of threading dislocations. We have realized the high quality Al0.6Ga0.4Sb layers on largely lattice-mismatched Si substrates by inserting a thin InSb layer between Al0.6Ga0.4Sb layer and GaSb/AlSb/GaSb buffer layer. Great improvements in material properties such as surface morphology and defect density have been observed.