Wafer-Scale Ni Imprint Stamps for Porous Alumina Membranes Based on Interference Lithography

摘要

In recent years, nanoporous anodic aluminum oxide (AAO) has been intensively exploited as a template material for the preparation of multifunctional nanostructures, which have applications in various scientific and technological fields.[1] In template-based materials synthesis, it is desirable to use a template with long-range order, so that structurally well-defined materials can be subsequently produced. In a typical anodization process, a self-ordered close-packed array of oxide nanopores forms with domain size (ordering length) on a scale of a few micrometers.[2] To achieve a long-range-ordered pore arrangement over a larger area, Masuda and co-workers first developed a pretexturing process that uses a SiC mold to produce ordered arrays of dimples on the Al substrate by nanoindentation prior to anodization.[3] Shallow indentations on an Al substrate initiate pore nucleation during anodization and lead to a long-range-ordered pore arrangement within the stamped area (e.g., 4? mm). This work has sparked considerable interest within the growing community of research groups using porous alumina, which is evident from the several hundred citations of these publications within a few years. However, few groups have been able to fabricate large-area, long-range-ordered alumina membranes due to the high processing costs of the imprint stamps, which can be a few thousand US