High-resolution X-ray diffraction was used to investigate the structures of Ga1-xInxAs epitaxial layers which had been grown under tension on (100) InP substrates. A nominal x-value of 0.42 corresponded to a small lattice mismatch and a 2-dimensional growth mode. Two samples were also grown under compression. The results showed that the residual strain, and the asymmetry in strain relaxation along <011> directions, were always greater for layers which were under tension. This was attributed to a difference in dislocation glide velocity that was caused by a difference in In content, to the dissociation of perfect dislocations, and partly to a difference in thermal expansion coefficient between substrate and epilayer. A larger asymmetry in strain relaxation for tensile-strained layers was attributed to the existence of micro-cracks that were aligned along the [011] direction.

P.Maigné, M.Gendry, T.Venet, Y.Tahri, G.Hollinger: Applied Physics Letters, 1996, 69[5], 682-4