Nanopatterning on Nonplanar and Fragile Substrates with Ice Resists

Anpan Han†, Aaron Kuan‡, Jene Golovchenko†‡, and Daniel Branton*§

^†Department of Physics, ^‡School of Engineering and Applied Sciences, and ^§Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 02138, United States

Nano Lett., Article ASAP

DOI: 10.1021/nl204198w

Publication Date (Web): January 9, 2012

Copyright © 2012 American Chemical Society

Electron beam (e-beam) lithography using polymer resists is an important technology that provides the spatial resolution needed for nanodevice fabrication. But it is often desirable to pattern nonplanar structures on which polymeric resists cannot be reliably applied. Furthermore, fragile substrates, such as free-standing nanotubes or thin films, cannot tolerate the vigorous mechanical scrubbing procedures required to remove all residual traces of the polymer resist. Here we demonstrate several examples where e-beam lithography using an amorphous ice resist eliminates both of these difficulties and enables the fabrication of unique nanoscale device structures in a process we call ice lithography.(1, 2) We demonstrate the fabrication of micro- and nanostructures on the tip of atomic force microscope probes, microcantilevers, transmission electron microscopy grids, and suspended single-walled carbon nanotubes. Our results show that by using amorphous water ice as an e-beam resist, a new generation of nanodevice structures can be fabricated on nonplanar or fragile substrates.