Nanofabrication with laser holographic lithography for nanophotonic structures

Abstract

Nanoscale periodic structures are gaining strong interests and finding more applications with their unique nanophotonic properties arising from photonic bandgap, plasmonic, and subwavelength structures. Integrating nanofabrication technologies from three dimensional laser holographic lithography, atomic layer deposition, nano machining, and nano desposition provides unique solutions by defining volumetric or surface nano structures, backfilling them with the active or passive materials of interest, and selectively creating functional aperiodic regions. We have demonstrated the fabrication of 3D photonic crystal templates in SU-8 on glass and Si substrates using laser holographic lithography. The voids in the photonic structures are filled with tungsten metal using atomic layer deposition. We have also investigated the feasibility of applying the laser lithograhically defined 2D structures to produce periodic nanoscale structures on a Si wafer using positive and negative photoresists. We have created functional defects in the template of periodic structures by focused ion beam milling to remove individual pillars or by direct write ion or e-beam deposition with gas injection system to fill holes or voids in the photonic structures. These device structures can lead to many photonic applications including lighting, display, sensor, and optical information processing.