Formation of TiO2 and ZrO2 Nanotubes Using Atomic Layer Deposition with Ultraprecise Control of the Wall Thickness

Nanotubes of TiO2 and ZrO2 (see Figure) with diameters of ca. 30–200 nm have been successfully fabricated by atomic layer deposition in a one-step process utilizing nanoporous membranes (commercial polycarbonate filters) as templates. Sub-angstrom wall thickness control and high aspect ratios can be achieved by this method.