Modeling of Porous Alumina Template Formation under Constant Current Conditions

Abstract

Anodized alumina templates have emerged as an important material system for the low-cost fabrication of semiconductor and metal nanostructure arrays. This material system uses natural self-organization for the creation of periodic arrays of nanoscale structures. In spite of the extensive experimental investigations reported in the literature, the theoretical mechanisms, and their dependence on process parameters such as current density and electrolytes, are not well understood. In this article, we propose a theoretical model based on the rate equation approach in which both the alumina formation and etching are considered. This model employs a minimal number of parameters and yet captures the essence of the experimental observations with sulfuric acid as the electrolyte and can be used as a predictive tool for process selection.

Revisiting anodic alumina templates: from fabrication to applications

“…The illustrations above portray the evolution of the undergrowing porous oxide film at each stage. Under galvanostatic conditions, in the profile of the recorded potential-time transient curve (not shown here), these same stages can be identified 127 . Chemical reactions involved along all the different stages of the anodization process in acidic media between the metal/oxide interface and oxide/electrolyte interface are as follow:…”

Highly Ordered Anodic Porous Alumina Formation by Self‐Organized Anodizing

“…The potential-time transients recorded during anodizing was studied carefully by Kanankala et al [334]. The theoretical model describing the potential-time behavior at the initial stage of anodizing conducted under the constant current regime in 0.21 M H 2 SO 4 or 0.3 M C 2 H 2 O 4 was developed.…”

“…The morphology of anodic porous alumina membranes was simulated using a radial function of distribution of cells in the triangular network [396], rate equations for competitive processes of alumina formation and etching [334,397], or linear stability analysis showing instability of oxide layer with respect to perturbations with a welldefined wavelength [398]. An electrical bridge model based on the analysis of ion transport in the oxide film and electrical field distribution was also proposed in an attempt to elucidate the self-organized growth of anodic porous alumina [399].…”

Alumina Porous Membranes Obtained by One-Step Anodizing Process in H2SO4 for MEMS Packaging

“…The pores are formed by partial dissolution of the oxidized aluminum during anodization (17). Dissolution is electrochemically enhanced at the bottom of the pores by the high electric field.…”