Three-dimensional (3D) compound semiconductor architectures can be formed when strained semiconductor layers are released from the substrate by selective etching. These 3D nanostructures have potential applications in nanoclectronics, nanophotonics and nanomechanics. In this paper, we report on the formation of In0.2Ga0.8As/GaAs 3D structures using lithographically defined micron-size, open-ended rectangular stripe patterns on films grown by metalorganic chemical vapor deposition (MOCVD). The formation process of nanotubes with diameters smaller than theoretical values has been analyzed. Unambiguous strain direction and crystallographic orientation dependence have been demonstrated. A geometry effect with respect to the longer and shorter sides of the rectangular pattern has been observed, indicating a pathway for high-degree control over the number of turns for such tubes and their positioning by lithographically defined stripe arrays. (C) 2007 Elsevier B.V. All rights reserved.