We propose a batch fabrication method for a double-layer microscale metamaterial resonator operating in the terahertz (THz) region. The proposed method takes advantage of scalloping structures formed by a general deep etching process. The scalloping structures function as a shadow mask. The shadow mask structure allows for the simultaneous fabrication of multiple metal layers with only a one-time evaporation step. The evaporated metal layers are electrically isolated from each other. In this paper, we fabricated a double-layer split-ring resonator (SRR) on a silicon substrate. The typical length of an arm of the SRRs was 40 μm, and the interlayer distance was 4 μm. Using energy-dispersive X-ray analysis, we confirmed that there was a non-evaporation area between the two SRR layers. We also confirmed that the fabricated sample functioned as a metamaterial in the THz region by transmittance measurements and simulation. These results prove that our method could lead to the realization of multilayer metamaterials.

References :
Akihiro Isozaki, Tetsuo Kan, Keisuke Takano, Masanori Hangyo, Kiyoshi Matsumoto and Isao Shimoyama,“Double-Layer Split-Ring-Resonator Array Fabricated Using Scalloping Structure,” Optical MEMS & Nanophotonics Conference, pp. 47-48, Banff, Alberta, Canada, August 6-9, 2012.

Akihiro Isozaki, Tetsuo Kan, Keisuke Takano, Masanori Hangyo, Kiyoshi Matsumoto and Isao Shimoyama,“BATCH FABRICATION OF A DOUBLE-LAYER METAMATERIAL RESONATOR USING SCALLOPING STRUCTURES,” Journal of Micromechanics and Microengineering, Institute of Physics, vol.23, no. 8, article no. 085006, 2013.[Proceedings]