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

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 mum 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 mum thick SU-8 negative photoresist. (C) 2004 American Vacuum Society.