Three dimensional fabrication by inclined rotary exposure

Arrays of micro overhanging structures were fabricated with very high uniformity by negative-tone photoresist of SU-8 and novel lithography technique, inclined rotary stage and backside exposure. Conventional chrome mask with an array of apertures was used as a substrate, and photoresist was directly spun on the mask. Rotational symmetric structures of SU-8 were obtained by irradiating through the apertures from the backside of the mask, inclining and rotating the stage. It is also possible to fabricate more elaborate and multilevel structures by using another photomask which partially blocks the rays at desired phase of rotation. In addition, light-guiding device with uniform draft angle was prototyped with this technique by using positive-tone photoresist of PMER P-CA1000PM and molding technique.