The fabrication of mono-domain highly ordered nanoporous alumina on a wafer scale by a guided electric field

Abstract

This paper describes the formation of mono-domain highly ordered nanoporous alumina on the scale of a 2 inch diameter silicon wafer by anodization of aluminium evaporated on a patterned SiO(2) mask on a silicon substrate. The position of the ordered pores correlates with holes in the SiO(2) mask, which guide the electric field during anodization and initiates pore nucleation. The technique is suitable for the production of ordered nanoporous alumina on a wafer scale and overcomes the time, cost and scale limitations of existing processes.

Porous Anodic Aluminum Oxide: Anodization and Templated Synthesis of Functional Nanostructures

“…silicon wafer has been also realized by directly anodizing thin aluminum films deposited on a lithographically generated SiO 2 mask, in which ordered SiO 2 holes underneath the aluminum film define the position of pore growth by effectively guiding the electric field during anodization. 332 Most of these techniques have demonstrated their effectiveness in fabrications of ideally ordered porous AAOs with tunable interpore distance (D int ) on brittle substrates over an extended dimension. However, they are inherently incapable of generating multiple copies of surface pre-patterns on aluminum.…”

Alumina Templates on Silicon Wafers with Hexagonally or Tetragonally Ordered Nanopore Arrays via Soft Lithography

“…23 Planting electric field guide under Al layer is also reported to be valid for well ordered nanoporous AAO. 24 Among those methods, prepatterning with direct imprint lithography would be attractive, since master mold can be repeatedly used and the method itself should be simple. Moreover, as shown by Masuda and coworkers, unusual packing symmetry such as tetragonal ordering can be produced.…”

In Situ Investigation of the Early-Stage Growth of Nanoporous Alumina

“…To improve the control of the formation of AAO arrays, various top-down methods have been proposed in the literature to prepattern the aluminum surface prior to the electrochemical treatment. Among them, focused ion beam lithography [8], holographic lithography [9], block copolymer micelles [10], soft imprinting [11], mould-assisted chemical etching [12], colloidal lithography [13], nanoindentation [14], nanoimprint lithography (NIL) [15,16], and guided electric field [17] can be cited. Such approaches are not only very interesting in terms of pores positioning and control of pore's size distribution but also allow the use of a micrometer-thick initial aluminum layer supported by a silicon wafer.…”