Effects of Gamma Ray Radiation on the Performance of Microelectromechanical Resonators
While much radiation test data is available for metal oxide semiconductor (MOS) devices, research into the effects of radiation on microelectromechanical systems (MEMS) is in its relative infancy. Piezoelectrically transduced MEMS resonators have broad applications in signal processing, environmental monitoring, and navigation. Aluminum nitride (AlN), in particular, is an attractive piezoelectric because of its favorable fabrication characteristics and ease of integration into the complementary MOS (CMOS) manufacturing process. The utility of these devices in space and nuclear systems necessitates research into their performance in radiation environments. Resiliency and an established relationship between radiation dose and device behavior provide a critical tool for engineers in their design process. We create multiple AlN-based MEMS resonator designs and expose the devices to 1 Mrad(Si) gamma irradiation from a Cobalt-60 source while measuring scattering (S-) parameters in situ. The experimental data is matched to a theoretical model to describe the change in frequency as a function of radiation-induced displacement damage. We also demonstrate that the AlN-based resonators are resilient against radiation-induced charge-trapping effects. Furthermore, we present a new method of permanent frequency trimming MEMS resonators up to 30% of their bandwidth without modifying quality factor or motional resistance.
Advanced Engineering Materials
Lynes, D. D., Chandrahalim, H., Bevins, J. E., & Petrosky, J. C. (2023). Effects of gamma ray radiation on the performance of microelectromechanical resonators. Advanced Engineering Materials, 25(14), 2201837. https://doi.org/10.1002/adem.202201837