Interference Lithography and Nanoimprint Lithography for Nanooptic Devices over Wafer-scale Area

Abstract

Deterministic fabrication of nanoscale structures over large area is crucial to practical applications of nanooptic devices, including plasmonic sensors, optical metamaterials and metasurface, structural color displays, just to name a few. Large-area fabrication of 1-D and 2-D gratings with sub-micron features is also important to many fundamental science and defense applications. This presentation will introduce our effort on developing innovative reconfigurable interference lithography techniques to create periodic gratings and pillar/hole array over waferscale area. Periodic lines and dots with sub-50 nm feature size and sub200 nm pitch are achieved. Combined with nanoimprint lithography and a series of nanofabrication processing, elementary patterns like lines and dots can be converted into more complex nanoscale structures that can play versatile functions. In addition to demonstrating large-area uniform nanopatterning, we will also showcase our deterministic fabrication of gradient nanostructures with feature sizes varying continuously with spatial position. Enabled by the advanced nanofabrication techniques, wafer-scale nanooptic devices have been developed as ultraviolet light filters, surface-enhanced spectroscopic sensors, gradient colorimetric sensors, etc.