Large-Area Bowtie Nanoantenna Arrays Fabricated with Economic Oxygen Plasma-Assisted Nanosphere Lithography

Bowtie nanoantenna arrays were fabricated using plasma-assisted nanosphere lithography. The gap of each bowtie nanoantenna was precisely controlled by tuning the oxygen plasma treatment time, and gap distance as small as 30 nm was successfully fabricated. The occurrence of plasmon coupling and the functionality of the bowtie nanoantenna arrays were experimentally and theoretically verified. The plasma treatments help to change the size and gap distance of the nanoparticle arrays to match a specific surface plasmon resonance wavelength. The fabricated nanoantenna array covered a large area (~1 cm²) and was suitable for large-scale fabrication with simple scale-up of the fabrication instruments, which should lead to novel new applications.