Vertical aligned ZnO nanowires were grown by metal-organic chemical vapor deposition technique on Si substrate. X-ray diffraction patterns and the high-resolution transmission electron microscopy confirmed the single crystalline growth of the ZnO nanowires along [0 0 0 1] direction. In another experiment, BaF2 films were deposited on silicon substrate by thermal evaporation. The BaF2 films show polycrystalline nature along with a granular surface morphology. Based on the solubility of BaF2 film in cold water, BaF2 layer was used as a sacrificial layer for the patterning of ZnO nanowire arrays. A sharp edge was obtained between the hexagonal pattern and the surrounding nanowires, which is suitable for micropatterning of ZnO nanowires for electronic devices. (C) 2009 Elsevier B.V. All rights reserved.