Nanopatterning on non-planar and fragile substrates with ice resists

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 non-planar 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 lithography1,2. We demonstrate the fabrication of micro and nanostructures on the tip of atomic force microscope probes, micro cantilevers, 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 non-planar or fragile substrates.