Sub-micrometre dielectric and metallic yablonovite structures fabricated from resist templates

Abstract

This paper reports the optical characterisation and numerical simulations of sub-micrometre yablonovite templates fabricated in poly-methyl methacrylate (PMMA) resist along with the pattern transfer to metals and other dielectrics. The fabrication is based on three consecutive exposures to an X-ray beam through a triangular lattice of holes. Up to seven (111) crystal periods are repeatedly obtained in thick PMMA layers. Optical characterisations of 1.3 μm period templates show well-defined stop-bands in the mid-infrared, in good agreement with the numerical simulations. Two simple and low-cost methods are used to replicate the yablonovite structures in other materials. The pattern transfers to a metal (copper) and a high-refractive-index dielectric (titanium dioxide) are obtained by electrodeposition and a sol–gel technique, respectively. Very regular yablonovite-type metallic structures of 2 μm lattice constant and 4.3 μm height are fabricated with metallic wires of 500 nm diameter over a surface of ∼150 × 150 μm2.