Challenges in barrier thinning of home-grown anodic aluminum oxide template on aluminum foil

Home-grown AAO templates allow for tuning the pore diameter and length and also ensure that the pores are uniform in size resulting in nanowires that have smooth surfaces. The biggest challenge with home-grown templates is the dissolution of the barrier layer. Depending on the anodizing potential, a thin barrier exists at the metal-dielectric interface. There are several strategies to thin and remove this barrier layer including: (i) a controlled voltage reduction process, (ii) chemical etching of the barrier after the AAO template is released from the aluminum foil and (iii) reverse anodization to thin the barrier layer. The removal or thinning of this barrier layer is critical for the use of the AAO template in applications, such as template growth of uniform arrays of nanowires and nanotubes on the aluminum host substrate. Results will be presented to show the growth of Co-InSb multi-layers in home-made anodic alumina oxide (AAO) templates that were prepared by critically controlling the barrier thinning and subsequent removal. The as-grown nanowires were characterized to study their electrical and structural properties.