Fabrication process for ultra high aspect ratio polysilazane-derived MEMS

We present a new process for fabricating polysilazane-derived MEMS components with ultra high aspect ratios. The width-to-height ratio of actual structures fabricated at this time is (/spl sim/20: 1), but shows promising results to achieve aspect ratios of 50: 1. Polysilazane-derived materials are a group of polymers and ceramics that can be functionalized to have a wide range of electronic, magnetic, dielectric, and optical properties. The fabrication process is based on contact lithography of a liquid photopolymer precursor, poly urea methyl vinyl silazane, PUMVS (Kion Corp.), with photoinitiator 2,2-dimethoxy 2-acetophenone, DMPA (Aldrich) for polysilazane. Contact lithography of aqueous photopolymers presents a substantial improvement in resolution, flatness of structures, and aspect ratio compared to microcasting and proximity printing for polysilazane-derived MEMS. In the future, this fabrication technique may be extended beyond polysilazane-derived materials to a wide variety of aqueous photopolymerizable sol-gels, preceramics, and photopolymers.