Direct copper nanofabrication on silicon substrate by atomic force microscope lithography

Desired copper patterns were directly fabricated through the electrochemical reduction by applying an electrical bias between an atomic force microscope (AFM) tip and a spin coated copper ion containing molecular resist film. A conductive and water soluble resist containing a mixture of copper nitrate hydrate and poly(sodium 4-styrenesulfonate) was used and the unexposed area was easily removed in development process. The negative sample bias strongly reduced copper ion at the point where an AFM tip was localized, and fabricated copper dot arrays and line patterns. The properties of the patterns were electrically and physically analyzed.