Nanofabrication of Plasmonic Structures

Nanofabrication technology is essential to create surface plasmonics that are generated by the interaction of nanostructures with light, and to exploit these plasmonics in photonic devices. Surface plasmonics properties are sensitive to the surface properties of the nanostructures, so great care must be taken when manufacturing them. With advances in nanofabrication technology, research in plasmonics has accelerated; for example, application of high-quality thin film growth methods has resulted in the properties of surface plasmonics approaching theoretical values. Top-down nanofabrication, represented by electron beam lithography or ion-beam milling technology, can produce sophisticated nanostructures such as bowtie-shaped nanoantennas or split-ring resonators, which achieve theoretically-proven optical properties and enable development of ultrasensitive bio-sensors and metamaterial devices. Bottom-up nanofabrication that exploits self-assembly synthesis enables the implementation of three-dimensional (3D) structures or active plasmonic devices that are difficult to implement using top-down processes and has increased the feasibility of mass production.