A novel fabrication method for nanostructures made of TiO(2), a hard-to-etch material with very attractive optical, physical and chemical properties, is developed. This technique 'atomic layer deposition array defined by etch-back' (AARDE) enables the formation of a large area of perfectly ordered, high aspect ratio nanostructures, such as nanopillars, nanotubes and nanochannels. High quality functional surfaces and versatile structures with tunable dimensions on various substrates can be realized. With all the process steps being controllable and compatible with integrated circuits, high throughput and repeatability are achieved. To demonstrate the potential of this new technique, results for AARDE TiO(2) nanopillar arrays as photonic crystals are also reported.