The atomic layer deposition array defined by etch-back technique: a new method to fabricate TiO2 nanopillars, nanotubes and nanochannel arrays

A novel fabrication method for nanostructures made of TiO2, 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 TiO2 nanopillar arrays as photonic crystals are also reported. (paper)