Strain relaxation in InAs/GaSb heterostructures

Lattice strain relaxation in InAs/GaSb heterostructures was investigated by x-ray diffraction. Two types of structures, grown by molecular beam epitax y, are compared. In the first, GaSb buffer layers were grown on GaAs substr ates, followed by 0.05-1.0 mu m thick InAs layers. In the second, InAs laye rs were grown directly on GaSb substrates. For a given thickness, the InAs layers retain significantly more strain when grown on GaSb substrates, refl ecting the lower threading dislocation density in the GaSb substrates relat ive to the GaSb buffer layers grown on GaAs. [S0003-6951(98)02251-7].