Fabrication of arrays of sub–wavelength nano–apertures in an optically thick gold layer on glass slides for optical studies
Résumé
We report on the fabrication of two-dimensional arrays of nano-optical apertures in gold layers by electron beam lithography (EBL) on a transparent glass substrate. 30 × 30 µm2 large arrays of high aspect ratio sub-wavelength cylinders (400 nm diameter with period of 1.81 µm) and annular apertures (diameters 250/330 nm and 310/330 nm inner/outer with period of 600 nm) were patterned in a 750 nm thick resist layer using a high contrast negative tone resist. The resist structures show sharp and vertical edges after development. The 150 nm thick deposited gold layer ensures optical transmission of less than 1.1 × 10-4 at 633 nm wavelength. White light based optical characterizations agreed with theory predictions and prove the good quality of the structures.