Laser precision engineering: from microfabrication to nanoprocessing

Laser precision engineering is being extensively applied in industries for device microfabrication due to its unique advantages of being a dry and noncontact process, coupled with the availability of reliable light sources and affordable system cost. To further reduce the feature size to the nanometer scale, the optical diffraction limit has to be overcome. With the combination of advanced processing tools such as SPM, NSOM, transparent and metallic particles, feature sizes as small as 20 nm have been achieved by near-field laser irradiation, which has extended the application scope of laser precision engineering significantly. Meanwhile, parallel laser processing has been actively pursued to realize large-area and high-throughput nanofabrication by the use of microlens arrays (MLA). Laser thermal lithography using a DVD optical storage process has also been developed to achieve low-cost and high-speed nanofabrication. Laser interference lithography, another large area nano fabrication technique, is also capable of fabricating sub-100 nm periodic structures. To further reduce the feature size to the atomic scale, atomic lithography using laser cooling to localize atoms is being developed, bringing laser-processing technology to a new era of atomic engineering. [GRAPHICS] 20-nm nanoline fabricated by 400-nm/100-fs laser irradiation through a near-field scanning microscope. (C) 2010 by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim