Figure 2
From: A Low-loss Metasurface Antireflection Coating on Dispersive Surface Plasmon Structure
Scanning electron microscope (SEM) images of three samples (MHA, a BCB layer coated MHA, MHA coated with an array of circular metal disks atop the BCB layer) and BCB coating condition.
(a) A periodic circular post photoresist (PR) pattern defined by standard photolithography. (b) E-beam deposition (5 nm of Ti and 50 nm of Au in sequence) and a liftoff processing, which leads to MHA structure. (c) Measured BCB thickness as a function of spin-coating speed and dilution ratio between BCB and rinse solvent. (d) BCB coated on MHA sample showing the flat-top surface. (e) A periodic circular hole PR pattern on the BCB layer shown in (d). Consecutive e-beam evaporations were used to deposit Ti (5 nm)/Au (50 nm) after (e), followed by a lift-off step. (f) Completed Meta-AR coated MHA (an array of circular metal disks atop the BCB coated MHA). Insets display the magnified MHA and MDA in Meta-AR coating.
