Laser assisted nanofabrications on metal surfaces with optical near field effects

Abstract

Laser directly writing of nanostrucrures on metal film surfaces with optical near field effects has been investigated. Spherical silica particles (500 - 1000 nm) were placed on metal films. After laser illumination with a pulsed ultraviolet laser, naoholes were obtained at the original position of the particles. The mechanism of the formation of nanostructure pattern was investigated and found to be the near-field optical resonance effect induced by particles on the surface. The size of the nanohole has been studied as a function of laser fluence and silica particle size. A comparison with relative theoretical calculations of near-field light intensity distribution showed good agreement with the experiment results. The method of particle enhanced laser irradiation allows the study of field enhancement effects as well as its potential applications for nanolithography.