Figure 5: Undercutting at step-edges
Patterned arrays of nanostructured trenches can be fabricated by the controlled undercutting of topographic features using isotropic wet etching, followed by deposition of a thin film. In this approach to nanofabrication, the initial step was to pattern a photoresist supported on a metal-coated substrate (e.g., chromium on silicon). The exposed metal film was isotropically wet etched with controlled undercutting of the photoresist.