Characterization of anodic aluminium oxide pores fabricated on aluminium templates

Abstract

Highly ordered anodic aluminium oxide (AAO) pores were successfully fabricated on aluminium template using a two-step anodization method. During the first anodization process, the diameter and density of AAO pores strongly depend on the anodization time. These disordered AAO pores must be removed by chemical etching. The concentration and temperature of phosphoric acid (H 3PO 4) solution are optimized, as is the etching time. A 6 wt% H 3PO 4 etching solution at 60 ∘C yields a smooth concave surface of the aluminium templates. Experimental data demonstrate that highly ordered AAO pores can be easily formed on the aluminium template with a highly concave surface. Finally, AAO pores (100 nm in diameter) with a pore density of 1.23×10 10/cm 2 are well defined across the whole aluminium template after the second anodization for 10 h.