Integrated lithography to produce complex structures for spectral engineering

TL;DR

This paper introduces an integrated lithography method combining interference and colloid sphere techniques to create complex, tunable plasmonic nanostructures with customizable symmetry, periodicity, and sub-structures for spectral engineering.

Contribution

The paper presents a novel integrated lithography approach (IICL) that enables independent control of multiple nanostructure parameters for advanced plasmonic applications.

Findings

Finite element simulations demonstrate the method's capability.

Complex plasmonic patterns significantly influence spectral properties.

Unique rectangular arrays of hole-doublets can be fabricated.

Abstract

An integrated interference and colloid sphere lithography (IICL) is presented to produce complex plasmonic structures consisting of wavelength-scaled periodic arrays of nano-objects with arbitrary array symmetry and controllable nano-scaled sub-structure. The IICL method is based on illumination of colloid sphere monolayers by interference patterns synchronized with sphere arrays along arbitrary crystallographic directions. This nano-kaleidoscope method enables to tune four structure parameters independently: the symmetry and characteristic periodicity of the interference pattern might be varied by the wavelength, number and angle of incidence of the interfering beams; the colloid-spheres' diameter-scaled distance between the nano-objects is controllable by the relative orientation of the interference pattern with respect to the hexagonal lattice of colloid spheres; the size of individual nano-objects is determined by the colloid-spheres diameter and by the light wavelength and is influenced by power density; the sub-structure size-parameter sensitively depends on the polarization state and can be tuned with the nano-object size simultaneously. Finite element method is applied to demonstrate the capabilities of IICL, and the impact of the resulted complex plasmonic patterns on spectral properties of thin gold films. The possibility to realize spectral engineering with predesigned rectangular arrays of hole-doublets that may be produced uniquely by IICL is shown.