Growth Sustainability of Nanopore Channels in Anodic Aluminum Oxide Guided with Prepatterns

Abstract

Nanoporous anodic aluminum oxide (AAO) has been widely used as a template for fabricating various nanostructured materials; however, the self-organization mechanism that governs the growth stability of nanopore channels has not been clearly understood. In this work, by a comparison of the growth sustainability of nanopore channels guided with focused-ion-beam patterning with numerical simulations based on a kinetics model, we demonstrated that as the acid concentration increases, the pore channel growth can transform from a barrier-type film mode to unstable growth, back to stable growth, and then to unstable growth again, with the growth rate increasing and the barrier layer thickness decreasing. The agreement between experiment and simulation indicates that an electric field alone can be the key driving force for self-organization in AAO.