Formation of nanostructures on the surface of metal films by the probe of an atomic-force microscope during the action of laser pulses

Abstract

When the probe of an atomic-force microscope is irradiated with pulses from a titanium-sapphire laser, nanostructures with characteristic diameter 30-70 nm and depth 5-15 nm are obtained on the surface of metal films. The formation thresholds of the structures have been measured, and studies have been made of how the thresholds depend on the polarization of the laser radiation, the widths of the laser pulse, and the distance between the point of the probe and the sample surface. It is found that the main cause for the formation of the nanostructures is the mechanical pressure of the probe on the sample when it elongates because of being heated by absorbed laser radiation. The use of pulses of femtosecond width made it possible to extend the range of materials subject to processing. © 2004 Optical Society of America