Medium-Volume GaN Metasurface Manufacturing Using Nanoimprint Lithography

In recent years, metasurfaces have emerged as a ubiquitous tool to control and manipulate the properties of electromagnetic waves by tuning the geometry and changing the composition of individual sub-wavelength unit cells. Their manufacturing, however, often requires methods that are expensive and difficult to scale such as Electron Beam Lithography (EBL) and deep UV lithography. The development of nanoimprint lithography (NIL), which provides in a table-top system the replication of nanoscale patterns, enables simple and accessible medium-volume metasurface manufacturing capabilities. NIL involves the replication of a nanopatterned master surface by stamping it into a UV- or thermally-curable material. In this work, a compact nanoimprinting (CNI) tool, supplied by NIL Technology, is characterized and proven as a viable manufacturing method for UV-NIL. NIL parameterization and testing for pattern replicability is presented, followed by an assessment of plasma deep reactive ion etching recipes for GaN metasurface manufacturing for visible wavelength applications, including imaging and sensing. Improving the manufacturability of metasurfaces using this NIL technique will allow for further testing of nanoscale optical components, as it facilitates the fabrication of many identical samples, which can be useful for the characterization of fabrication processes and studying reconfigurable metasurfaces