Product Code: PIC2008_M205

Large Area Nanopatterning of Silicon Surface by Chemical Assisted Laser Processing using Near-Field Enhancement by Particle-Lens Arrays
Authors:
Wei Guo, 1Laser Processing Research Centre, School of Mechanical, Aerospace and Civil Engineering; Manchester Great Britain
ZENGBO WANG, Laser Processing Research Centre; Manchester Great Britain
Lukyanchuk Boris, Data Storage Institute, Dsi Building, 5 Engineering Drive 1, Singapore; Singapore Singapore
David Whitehead, 1Laser Processing Research Centre, School of Mechanical, Aerospace and Civil Engineering; Manchester Great Britain
Lin Li, 1Laser Processing Research Centre, School of Mechanical, Aerospace and Civil Engineering; Manchester Great Britain
Zhu Liu, Corrosion and Protection Centre, School of Materials; Manchester Great Britain
Presented at PICALO 2008

Nanopattering of silicon substrates using near-field enhancement by particle-lens arrays in a chemical solution is presented for the first time. Both experimental and theoretical investigations have been carried out to understand the properties of the nano-patterns produced. The obtained results proved that the developed nanofabrication technique is a flexible method for precise surface nanopatterning over large area surface. Novel nanostructures such as nano-bump and ring arrays, that previously not possible to be produed using the particle-lens arrays, have been demonstrated using this technique. A close-packed monolayer of silica spheres (r= 250 nm) was directly formed onto the silicon surface by self-assembly, and a 248nm wavelength KrF excimer laser was used to irradiate the samples. The theoretical modeling of the optical near-field is based on extended Mie theory. The effect of the laser fluence and assisted chemicals is studied. Due to the focusing of the particle lens, a reaction between the chemical solution and substrate can be induced in the locally high energy region. As a result, a lower laser fluence than the ablation threshold of bulk silicon can be used to generate nano-scale features.