Surface nanostructuring by nano-/femtosecond laser-assisted scanning force microscopy

Surface nanostructuring with lateral resolutions beyond the capabilities of conventional optical lithography techniques was demonstrated in this study. Various nanoscopic surface features, such as grids, craters, and curves, were produced on thin metal and semiconductor films and bulk silicon by using the enhanced electric field underneath a proximity scanning probe tip irradiated with a laser beam. Nanoscale melting and crystallization of amorphous silicon films illustrates the capacity of the present scheme to provide an effective nanolaser source. Numerical simulations yield insight into the spatial distribution of the enhanced field intensity underneath the tip and associated physical phenomena. Calculations of the temperature distribution in the microprobe tip and possible tip expansion show that the main reason for the highly localized nanostructuring achieved with this technique is the enhancement of the electric field in the tip-sample gap. Possible applications of the developed nanostructuring process are anticipated in various nanotechnology fields. (c) 2005 American Institute of Physics.