Fabrication of high-density nanostructures by electron beam lithography

We demonstrate a fabrication method to define high-density, uniform nanostructures by electron beam lithography at conventional beam voltages (<40 kV). 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 dots with 25 nm period and 20 nm lines with 40 nm period were fabricated to show the resolution of this optimized process. (C) 1998 American Vacuum Society. [S0734-211X(98)19106-0].