Lattice-strain relaxation in heterostructures was investigated by means of X-ray diffraction. Two types of structure, which had been grown using molecular-beam epitaxy, were compared. In one of them, GaSb buffer layers were grown onto GaAs substrates followed by 0.05 to 1μ-thick InAs layers. In the other, InAs layers were grown directly onto GaSb substrates. For a given thickness, the InAs layers retained significantly more strain when grown onto GaSb substrates; thus indicating a lower threading dislocation density in GaSb substrates as compared with GaSb buffer layers which had been grown on GaAs.

Strain relaxation in InAs/GaSb heterostructures B.R.Bennett: Applied Physics Letters, 1998, 73[25], 3736-8