title: Three-dimensional deep sub-diffraction optical beam lithography with 9 nm feature size.
abstract: The current nanofabrication techniques including electron beam lithography provide fabrication resolution in the nanometre range. The major limitation of these techniques is their incapability of arbitrary three-dimensional nanofabrication. This has stimulated the rapid development of far-field three-dimensional optical beam lithography where a laser beam is focused for maskless direct writing. However, the diffraction nature of light is a barrier for achieving nanometre feature and resolution in optical beam lithography. Here we report on three-dimensional optical beam lithography with 9 nm feature size and 52 nm two-line resolution in a newly developed two-photon absorption resin with high mechanical strength. The revealed dependence of the feature size and the two-line resolution confirms that they can reach deep sub-diffraction scale but are limited by the mechanical strength of the new resin. Our result has paved the way towards portable three-dimensional maskless laser direct writing with resolution fully comparable to electron beam lithography.
authors.affiliation: Centre for Micro-Photonics and CUDOS, Faculty of Engineering and Industrial Sciences, Swinburne University of Technology, Hawthorn, Victoria 3122, Australia.
authors.forename: Zongsong
authors.initials: Z
authors.lastname: Gan
authors.forename: Yaoyu
authors.initials: Y
authors.lastname: Cao
authors.forename: Richard A
authors.initials: RA
authors.lastname: Evans
authors.forename: Min
authors.initials: M
authors.lastname: Gu