Theoretical and experimental studies on the parylene diaphragms for microdevices

In this paper, parylene diaphragms with planar and corrugated shapes are fabricated and tested. Although, recently in MEMS, parylene has been used for a diaphragm material due to its excellent property, no theoretical and analytical studies of the parylene diaphragm have been performed. Therefore, the characterization of the parylene diaphragms is studied through both experiments and simulations. Thermal and load-deflection analyses for diaphragms are carried out to find the effect of residual stress on the behavoir of the diaphragm. The measured deflections are compared with both analytical calculations and FEM simulations that considers the influence of the thermal stress. Those results show excellent agreement. In order to find an optimum shape of the corrugated diaphragm, the influence of the corrugation number and the corrugation depth on the mechanical sensitivity of the corrugated diaphragm is studied parametrically.The authors would like to thanks to Dr. Sang Sik Yang and coworkers in the Microsystems Lab., School of Electronics Engineering, Ajou University for the help with device processing. This research was sponsored by Institute for Applied Science and Technology of Sogang University.