Fabrication technology for three dimensional metallic photonic crystal slab

Optical resonances with light wave vectors in a photonic crystal (PhC) slabs depend on the shape, size, period, and thickness of the structures. In case of the metallic PhC, there has been a limitation to control the thickness of the metallic structures, more especially thick metallic structures. In this paper, the new fabrication technology for three dimensional metallic PhC with thick metallic structures has been demonstrated. To realize the thick metallic PhC, e-beam lithography with thick resist, gold sputtering with rotating tilted stage, and reactive ion etching with argon and tetrafuluoromethane were performed. The measured absolute reflectance spectra of fabricated three dimensional metallic PhC were studied as a function of the incident light wave angle from the visible region to near infrared region. It was found that fabricated three dimensional metallic PhCs show resonance peaks in the light wave region.