Particle-enhanced near-field optical effect and laser writing for nanostructure fabrication

Abstract

In this paper, we present a novel method of nanostucture fabrication using particle-enhanced near-field optical effect and lasers. For this purpose, spherical silica particles were deposited on a silicon surface. After laser illumination, hillocks with size of about 150 nm were obtained at the original position of the particles. The mechanism can be explained as the enhancement of light intensity near the contact area. Since the characteristic distance between particles and substrate is smaller than the radiation wavelength and the particle size is of the order of a wavelength, particle does not simply play the role of microfocusing lens as in far-field, but possess optical resonance effect in near-field. In our work, the light intensity on the surface under the spherical particle was calculated by solving the electromagnetic boundary problem "particle on suface".