Search

Free standing metal screens have long been used as band pass filters in the infrared (IR) wavelength region. One adjusts the screens’ periodicity constant, its opening-to-periodicity aspect ratio and its thickness to achieve desired infrared transmission properties. Here we concentrate on thick screens in the near IR wavelength region (1–2 μm). In addition to experiments and simulations we have considered the role of screen imperfection on its transmission characteristics. Uneven surfaces, inclined and sometimes rough walls of the screen and waveguide channels may be the result of thick-film lithography which is used in the process for screen manufacturing. Understanding these effects is crucial to applications of these filters in the entire IR region.

With a view to meeting the requirements of high resolution microelectromechanical system applications, we studied high resolution (submicron scale) and high aspect ratio pattern fabrication through x-ray lithography. As a critical part of the x-ray lithography, an x-ray mask should have the properties of high resolution and being a thick absorber. To decrease the scattering effect, a 100 keV e-beam lithography system was used for the fabrication of the high resolution x-ray mask. 3 ?m thick PMMA (polymethylmethacrylate) resist was patterned and 2 ?m thick gold was electroplated onto the patterned resist to form the x-ray mask. Scanning electron microscopy analysis showed that the sidewall and pattern uniformity were sufficient and that the proximity effect did not play a significant role for the selected test patterns. 6 ?m thick PMMA resist was exposed by the x-ray mask; the experimental results proved the feasibility of reproducing submicron features. 0.5 ?m nested patterns with an aspect ratio of 12 were fabricated by this approach.

Thick capacitive meshes of nickel on substrates of thickness 25 lm have been produced by electroplating into a photoresist mould. The Micro-Stripes program by Flomerics has been used for the interpretation of the experimentally measured far infrared spectrum. The measured reflection resonance mode and the transmission wave guide mode agree well with the analytical predictions. 2003 Elsevier B.V. All rights reserved.

This paper presents a technology study for fabrication of ''V''-shaped silver nanoantennas with critical dimensions below 20nm. Two process sequences are investigated based on electron beam lithography, a lift off process using the positive resist polymethylmethacrylate (PMMA) and a novel process based on argon ion etching using the negative resist hydrogen silsesquioxane (HSQ). The fabrication processes are monitored by SEM investigations. Attenuated total reflection (ATR) measurements demonstrate the optical activity of the nanoantennas and allow the validation of the technology routes.