A method for forming anodic aluminum oxide (AAO) on a substrate includes disposing an Al layer on the substrate, there being a Cu layer between the substrate and the Al layer, and a TiW alloy layer between and in contact with the Cu layer and the Al layer, anodizing the Al layer to provide an AAO layer comprising nanopores extending into the AAO layer to a barrier layer of the AAO at a base of each nanopore and converting at least some of the TiW alloy layer to TiW oxide, over-anodizing the barrier layer to remove at least a portion of the AAO of the barrier layer at the base of each nanopore, and exposing the AAO layer, the TiW oxide, and the TiW to a chemical etchant sufficient to extend the nanopores through the AAO layer to a surface of the Cu layer.