We demonstrate a fabrication method to define high-density, uniform nanostructures by electron beam lithography at conventional beam voltages ͑Ͻ40 kV͒. Here we optimize the exposure and development conditions needed to generate such nanostructure arrays using polymethylmethacrylate as positive resist and isopropyl alcohol as a developer. Arrays of 12 nm… (More)
We designed, fabricated, and characterized a binary diffractive lens with features less than 60 nm. The lens was designed for operation in the red portion of the spectrum. Experimental measurements of lens performance agree with predictions generated by rigorous models of diffraction.