The appearance of quantum wirelike morphology on InGaAs single quantum well structures grown by molecular beam epitaxy on (100)InP vicinal surfaces is reported. The results of transmission electron microscopy reveal that the misorientation of the substrate drives the development of a lateral contrast modulation related to In‐rich or Al‐rich regions oriented along {133} or {122} planes that initiate on the InAlAs tensile buffer layer and propagate across the structure, giving rise to an anisotropic rippling of the InGaAs well. Conversely, a misfit dislocation network at the InAlAs/InP interface was observed for the same layers grown on exact (100) surface. A comparison of the two structures suggest that the development of such modulated configuration is apparently a strain relieving mechanism. ©1995 American Institute of Physics.