Up to date, electromagnetic metamaterials (EM₃) have been mostly fabricated by primary pattern generation via electron beam or laser writer. Such an approach is time-consuming and may have limitations of the area filled with structures. Especially, electron beam written structures are typically confined to areas of a few 100×100 μm². However, for meaningful technological applications, larger quantities of good quality materials are needed. Lithography, in particular X-ray deep lithography, is well suited to accomplish this task. Singapore Synchrotron Light Source (SSLS) has been applying its LIGA process that includes primary pattern generation via electron beam or laser writer, X-ray deep lithography and electroplating to the micro/nano-manufacturing of high-aspect ratio structures to produce a variety of EM³ structures. Starting with Pendry's split ring resonators, we have pursued structure designs suitable for planar lithography since 2002 covering a range of resonance frequencies from 1 to 216 THz. More recently, string-like structures have also been included. Latest progress made in the manufacturing and characterization of quasi 3D metamaterials having either split ring or string structures over areas of about ≈1 cm² extension will be described.

Date Published: 4 September 2008
PDF: 12 pages
Proc. SPIE 7029, Metamaterials: Fundamentals and Applications, 70290E (4 September 2008);

Published in SPIE Proceedings Vol. 7029:
Metamaterials: Fundamentals and Applications
Mikhail A. Noginov; Nikolay I. Zheludev; Allan D. Boardman; Nader Engheta, Editor(s)