Facile Electron-Beam Lithography Technique for Irregular and Fragile Substrates

A facile technique is presented which enables high-resolution electron beam lithography on irregularly-shaped, non-planar or fragile substrates such as the edges of a silicon chip, thin and narrow suspended beams and bridges, or small cylindrical wires. The method involves a spin-free dry-transfer of pre-formed uniform-thickness polymethyl methacrylate, followed by conventional electron beam writing, metal deposition, and lift-off. High-resolution patterning is demonstrated for challenging target substrates. The technique should find broad application in micro- and nano-technology research arenas.

This research was supported in part by the Director, Office of Energy Research, Office of Basic Energy Sciences, Materials Sciences and Engineering Division, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231 under the sp2–bonded Materials Program, which provided for postdoctoral support, design and execution of the experiment, and e-beam writing and characterization instrumentation; and by the National Science Foundation under Grant DMR-1206512 which was provided for postdoctoral support and bridge test devices. We thank the Berkeley Marvell Nanofabrication Laboratory for providing additional specialized equipment for device fabrication.