Fabrication of Nonperiodic Metasurfaces by Microlens Projection Lithography

Abstract

This paper describes a strategy that uses template-directed self-assembly of µm-scale microspheres to fabricate arrays of microlenses for projection photolithography of periodic, quasiperiodic, and aperiodic infrared metasurfaces. This method of “template-encoded microlens projection lithography” (TEMPL) enables rapid prototyping of planar, multi-scale patterns of similarly shaped structures with critical dimensions down to ~ 400 nm. Each of these structures is defined by local projection lithography, with a single microsphere acting as a lens. This paper explores the use of TEMPL for the fabrication of a broad range of two-dimensional lattices with varying types of non-periodic spatial distribution. The matching optical spectra of the fabricated and simulated metasurfaces confirm that TEMPL can produce structures that conform to expected optical behavior.