Superlens-enhanced laser interference lithography

A one-step lithography method based on a superlens is proposed to fabricate diffraction-unlimited metallic patterns. By controlling the material parameters and the distribution of the impinging energy, various phenomena, such as periodic nanonetworks, ultrathin nanowires (sub-50-nm feature size), and variable-sized nanoparticles (ranging from sub-10nm to several hundreds of nanometers), are fabricated using a 1,064-nm nanosecond laser. The evolution pathway of such phenomena is explained by the dewetting process of metallic films. The direct-writing performance of a transparent material with a superlens is studied, and the maximum etching depth of Si gratings can reach 2 μm under a single laser pulse, with fine profiles. © 2018 The Japan Society of Applied Physics