Transient characteristics of BCB encapsulated surface micromachined aluminum micro-mechanical resonators

In this contribution, the transient characteristics of benzo cyclo butene (BCB) encapsulated aluminum (Al) micro mechanical resonators as a function of time varying pressure are studied. The quality factor of encapsulated Al resonator showed a drastic change with time of more than 200% reduction. The estimated transient leak rate spans over several orders of magnitude (10⁵ to 10^-9 atm cm³ s^-1). A theoretical description of Al micro mechanical resonator and the leak rate are presented. Possible causes for the leak rate and the potential solutions are also outlined.