Radiation effects on microelectromechanical systems
Liao, Wenjun
:
2018-08-23
Abstract
The effects of ionizing radiation and displacement damage are two significant reliability
concerns for transducer applications in radiation environments. Microelectromechanical systems
(MEMS) are considered as potential transducer candidates for space systems and nuclear
reactors. The successful application of MEMS in radiation environments requires that these
reliability issues be thoroughly explored and understood. The total-ionizing-dose (TID) effects
on piezoelectric micromachined acoustic transducers (pMUTs) and electrothermal microscanners
were studied by using experimental characterization of mechanical and electronic property
changes due to radiation exposure and calculation of parametric changes. The radiation induced
charge accumulation changes the stress distribution in pMUTs and leads to resonant frequency
shifts. Also, the charge can move the electrothermal microscanner structures through the
electrostatic force and generate additional displacement offset. A new Monte Carlo modeling
approach is proposed for analyzing and calculating the defect density generated in suspended
monolayer graphene by energetic ion bombardment. The results help the understanding of
displacement damage in two dimensional materials.