Nanoscale silicon structures by using carbon nanotubes as reactive ion etch masks

We demonstrate that multiwalled carbon nanotubes can be used as etch masks in a reactive ion etch, yielding silicon structures defined by the size and orientation of the carbon nanotube. The relationship between etch profile and reactive ion etch parameters is optimized to yield an anisotropic etch with vertical sidewalls, supporting carbon nanotubes of diameters down to 25 nm, without apparent damage to the nanotube. We demonstrate that the etched structures can be used as thermal nanoimprint stamps and that the carbon nanotube remains on the etched ridge after imprinting. The method is a route for creating nanoscale structures with a resolution defined by the smoothness and width of a macromolecular structure.