Focusing of Laser Radiation in the Near-field of a Tip (FOLANT) for Applications in Nanostructuring

Abstract

Current research work has shown that ‘focusing’ of laser radiation down to a few nanometres can be achieved by using near-field technology, e.g. scanning tunnelling microscopy (STM) or atomic force microscopy (AFM), in combination with a laser. Lateral external illumination of a probe tip with laser radiation can cause a tremendous intensity enhancement of up to 5×105 in the near-field underneath the probe tip. This effect can be explained by different electrostatic as well as electrodynamic effects known from surface-enhanced raman spectroscopy (SERS). This enhancement effect was utilized to concentrate laser radiation with high intensity between a tip and a substrate. This FOLANT (focusing of laser radiation in the near-field of a tip) technique can be applied for material processing on a nanometre scale. Using an STM/laser combination, hillocks, pits and grooves with lateral dimensions down to 10 nm have been obtained on gold substrates. The AFM/laser combination enabled nanostructures down to 20 nm to be established on dielectric materials such as polycarbonate.© 1997 John Wiley & Sons, Ltd.