Fabrication of three-dimensional microstructures using standard ultraviolet and electron-beam lithography

Abstract

We have designed and fabricated shape-controlled three-dimensional structures combining electron- beam and ultraviolet (UV) lithography. Starting with a tiff file format, a gray scale pattern using a high energy beam sensitive mask is produced with electron-beam direct writing. In only a one step UV exposure, an optical lens and a photonic band gap structure in 16.5 μm thick AZ 4562 positive photoresist, with controlled profile and smooth resist surface, were fabricated. A three-dimensional grid structure was also transferred to a 100 μm thick SU-8 negative photoresist.