InxAl1−xAs layers on InP substrate could be subjected to compressive as well as tensile strain due to lattice parameter differences induced by suitable alloy composition changes. The 2μm thick InxAl1−xAs (0.50 ≤ x ≤ 0.53) layers were grown on (001) oriented InP substrates by molecular beam epitaxy. They were investigated by using X-ray diffraction and chemical etching. X-ray studies were performed applying high-resolution diffractometry in double and triple axis configuration. It was found that the In0.53Al0.47As/InP layer under compressive strain relaxes partially along two <110> directions. On the other hand, the In0.50Al0.50As/InP layers, being under tensile strain, consist of 2 sub-layers; the first one, adjacent to the substrate was pseudomorphic whereas the upper sub-layer was partially relaxed and the relaxation was anisotropic. The upper sub-layer was fully strained in the [110] direction while partially relaxed in the [¯110] one.

Defect Structure of InAlAs/InP Layers. A.Shalimov, J.Bak-Misiuk, J.Kaniewski, J.Trela, W.Wierzchowski, K.Wieteska, W.Graeff: Journal of Alloys and Compounds, 2005, 401[1-2], 221-5