Ultrafast Laser-Induced Two-Photon Photopolymerization of SU-8 High-Aspect-Ratio Structures and Nanowire

A three-dimensional microstructure with several tens of nanometer resolution can be fabricated using the ultrafast laser-induced two-photon photopolymerizing fabrication technique. In this fabricating technique, SCR-500 (urethane acrylate) and SU-8 (epoxy) are used as two-photon absorbing photopolymerizable resins. SCR-500 has been used widely to fabricate a 3-D microstructure with highly precise details, but its high-aspect-ratio structure is naturally excessively. On the other hand, SU-8 is rigid, so a high-aspect-ratio microstructure can be fabricated with SU-8. In this report, various aspect-ratio microstructures with SCR-500 and SU-8 were fabricated and the viability of the structures was investigated. Also a 70 nm-linewidth nanowire, which connects between two high-aspect-ratio structures, was fabricated.