From Transparent Particle Light Enhancement to Laser Nanoimprinting

Laser beam, electron beam & focused ion beam are attracting much research interests in functional nanostructure fabrication. Laser irradiation under near field is one of the effective ways to break light diffraction limit and push patterning feature size down to dozens of nanometers. In this paper, nano-hole array patterning by a parallel particle mask is described. Transparent nanoparticles were self-assembled on phase change GST thin film surfaces. Following with the pulsed laser irradiation, nano-hole arrays were formed uniformly on the surfaces. Laser fluence effect and angle dependence of the nanostructures are investigated. Physics behind this laser nanostructuring shows that these transparent nanoparticles serve as "nano-lenses" to induce light intensity enhancement under the transparent particles. Theoretical simulations indicates that light intensity enhancement is related to particle size and light wavelength. To extend this technique application, the feasibility of laser nanoimprinting for next generation nanodevice fabrication is also studied.