Investigation of lateral modulation in antimonide superlattices

Lateral structure is investigated in two antimonide superlattices using x-ray diffraction. We report periodic lateral modulation in AlSb/AlAs digital superlattices, while no lateral modulation is observed in similar InAs/Al(In)Sb digital superlattices. By fitting the diffraction data with dynamical diffraction theory we are able to determine the strain in each layer and at the interfaces. The findings are consistent with recent predictions of the critical thickness for three-dimensional growth.