Fabrication of ideally ordered anodic porous alumina with 63 nm hole periodicity using sulfuric acid

Abstract
Nanochannel arrays with an ideally ordered hole configuration with a 63 nm hole periodicity and 15–40 nm hole diameter were fabricated using anodization of the pretextured Al in sulfuric acid solution. The SiC mold with an array of convexes, which was prepared by electron beam lithography, was used for the nanoindentation of the Al. The periodicity of convexes was adjusted to the self-organized periodicity in sulfuric acid solution. The obtained concaves on Al initiated the hole development during the anodization and generated the ideally ordered hole configuration with a 63 nm period. Under the appropriate anodization conditions, anodic porous alumina with an aspect ratio of over 20 was obtained.