Formation of Self-assembled Nanostructure on Noble Metal Islands Based on Anodized Aluminum Oxide

摘要

Anodized aluminum oxide(AAO)has been considered an attractive template for simple fabrication of highly-ordered nanostructures.It provides a 2-dimensional array of hexagonal cells with pores of uniform diameter and inter-pore distance that are adjustable in the range of a few tens to hundreds of nanometers.It can be easily grown on an aluminum sheet with high purity by a sequence of several electrochemical steps;electro-polishing,the 1st anodization,etching,and the 2nd anodization.The pores are grown vertically with respect to the AAO surface.The regularity of the pore structure is usually limited by the inherent grain domain in the aluminum sheet to a few micrometers,but can be improved to cover many millimeters of monodomain by pre-indenting the aluminum sheet with SiC or Si_3N_4 molds.Although fabrication of such molds requires elaborate and costly processes with e-beam nanolithography,such potentially superb regularity can be practically applied to fabrication of nanoscale devices in electronics,optics,biosensors,etc.