Optimizing the fabrication of aluminum-coated fiber probes and their application to optical near-field lithography

We report on routine fabrication of fiber probes suitable for metal coating. We have investigated how aperture sizes ranging from 75 to 300 nm can be produced using an appropriate set of pulling parameters in a combined heating/pulling process. The quality of the metal coating has been investigated in terms of roughness and the presence of leaking holes in the coating. We report on how the quality of the coating depends on parameters such as deposition rate and background pressure during evaporation. We have used aluminum-coated fiber probes in lithographical studies of different materials, like side-chain azobenzene polyesters and hydrogen-passivated silicon surfaces displaying linewidths as narrow as 20 nm.