An effective method for the catalyst-free selective-area growth of single-crystalline zinc oxide nanowires on patterned substrates defined by e-beam lithography and treated by chemical etching with increased surface roughness is reported. The nanowire growth is realized via a surface-roughness-assisted vapor solid mechanism by thermal evaporation. The nanowires are vertically aligned on sapphire and randomly oriented on silicon substrates. (c) 2008 Elsevier B.V. All rights reserved.