Fine gold grating fabrication on glass plate by imprint lithography

摘要

In this paper, fabrication of a fine gold grating on glass substrate is demonstrated using imprint lithography for optical elements. A Si mold with fine grating patterns is prepared using conventional IC's process. The line widths of the gratings are varied from 1.0μm to 200nm. About 20nm thick Si_3N_4 film is coated on the mold surface by LP-CVD to improve hardness of the mold. The Si mold is pressed to a gold film on a glass substrate at room temperature. To eliminate fatal fracture of the sample in pressing, the form of the sample is just aligned to the mold to avoid stress concentration at the mold edges. The gold film is plastically deformed and fine gold grating with 200nm in line width and 300nm in height is successfully fabricated on the glass plate. The cross sectional profile of the gold pattern is fine rectangular shape. Using room temperature direct imprint lithography, metal gratings are successfully fabricated on a glass plate. This method is a promising way to fabricate fine micro optical elements by low cost.