Fabrication of ordered anodic alumina oxide for imprinting templates

Abstract

Porous Anodic Aluminum Oxide (AAO) has been widely known for its ability to form hexagonally packed nanostructured arrays. AAO assisted approach also provides many advantages over conventional lithographic techniques for the fabrication of simple sub-100 nm nanostructure arrays. Nanostructured arrays fabricated on surfaces have wide range of potential applications in areas such as micro and nanoelectronics, photoelectronics, information storage, sensing, etc. In this project, soft-imprinting method by using Reactive Ion Etching (RIE) to transfer the hexagonal arrays pattern of the AAO mask onto another substrate will be demonstrated. First of all, the method to fabricate free standing AAO mask will be proposed. The term free standing here refers to mechanically reinforced AAO templates (e.g. using PMMA coating as the mechanical support) so that large areas of very thin layer AAO templates (< 1 μm) could be fabricated and easily handled during the process. Next, soft imprinting method on SiO2 substrates by RIE using a free-standing AAO mask will be proposed and demonstrated. Removal of PMMA coating before the RIE was critical, so two methods of PMMA removal will be studied in this project. The main focus of this project was to study the feasibility of transferring the hexagonal array pattern from the AAO mask onto the SiO2 substrate.