Rim morphology of nanopore for studying single biomolecule

The fabrication and application of micro- and nanoscale containers and devices are recently attracted much attention. The top profiles of these nanoscale patterns are very important for nano-devices integration. The morphologies of small containers, nanopit and nanopore fabricated with focused ion beam (FIB) milling tool, are explored by atomic force microscopy (AFM). The topography of every pattern looks like a volcano. The protruded ring-shaped structures surrounding the crater are attributed to the swelling due to the amorphization when FIB processed the crystal silicon nitride (Si3N4) substrate. In addition, the morphologies of anodic alumina oxide (AAO) membranes fabricated by anodizing of metallic aluminum are discussed.