Fabrication of multi-layered SiCN ceramic MEMS using photo-polymerization of precursor

This paper describes the use of photo-polymerization of precursor as a versatile and cost-effective means of fabricating SiCN ceramic MEMS. SiCN is a new class of polymer-derived ceramics whose starting material is a liquid-phase polymer. By adding a photo-initiator to the precursor, photolithographical patterning of the precursor can lie accomplished by UV exposure. The resulting solid polymer structures are then crosslinked under isostatic pressure, and pyrolyzed. Thermal decomposition transforms the polymer to an amorphous ceramic capable of withstanding over 1500/spl deg/C. By adding and curing successive layers of liquid polymer precursor on top of one another, multi-layered ceramic structures can be easily fabricated. The use of photo-polymerization can also be used to make thin, membrane-like ceramic structures. By combining photo-polymerization with other in-house developed techniques such as polymer-based bonding and flip-chip bonding, three SiCN MEMS devices for high temperature applications have been fabricated: an electrostatic actuator, a pressure transducer, and a combustion chamber. These represent a wide range of MEMS, demonstrating the versatility of this technique.