Advanced Metal Lift-offs and Nanoimprint for Plasmonic Metal Patterns

An effective and reliable fabrication approach for silver nanostructure arrays was developed using UV nanoimprint with a lift-off resist and a Si-based etch mask for enhanced plasmonic resonance-driven device performance. Since a tapered nanopillar array is imprinted on the resist, by coating it with a Si-based etch mask layer and carrying out the etching procedure, a reverse-tapered nanohole array for metal deposition can be crated. Compared to the conventional lift-off process, a more tolerable window of life off process conditions is possible, and dot patterns with high-aspect-ratio thickness profiles and no rabbit ears can be fabricated. Simulation results corresponding to dot diameters of 150, 235, and 265 nm (twice those in their period) were qualitatively in good agreement with experimental results in terms of transmittance. This suggests that the proposed technique is a fairly reliable and accessible fabrication strategy for applications.