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Posted: Jun 01, 2017
Metamaterial allows for ultraviolet nanolithography below the diffraction limit
(Nanowerk News) Reporting their work in ACS Applied Materials & Interfaces ("Optically Patternable Metamaterial Below Diffraction Limit"), researchers in Korea report an optically patternable metamaterial comprised of monolayered silver nanoislands embedded within a photosensitive polymer resin for ultraviolet nanolithography.
This metamaterial exhibits the excitation of surface plasmons under ultraviolet exposure and defines clear subdiffraction limited image patterns to overcome the physical limit of the characteristic distance of diffraction.
The silver nanoislands also effectively facilitate the rapid removal of unexposed regions during the development process because they allow a developing solution to rapidly permeate through the polymer resin.
In conjunction with a conventional contact mask aligner, the OPM with monolayered Ag nanoislands embedded in an ultrathin photosensitive polymeric (SU-8) layer effectively served as a new class of photoresist for the ultraviolet nanolithography of arbitrary nanopatterns, with a minimum line width of 70 nm (< λ/5), beyond the near-field zone, under one-shot UV exposure.
Unlike conventional nanolithographic methods such as electron beam, scanning probe, or nanoimprint lithography, this new material provides a large-area, high-throughput, and low-cost nanopatterning method, and provides new insights for optical nanolithography below the diffraction limit.