Here is the abstract you requested from the IMAPS_2011 technical program page. This is the original abstract submitted by the author. Any changes to the technical content of the final manuscript published by IMAPS or the presentation that is given during the event is done by the author, not IMAPS.
|AUTHOR WITHDREW 8-20-11: Reliable Vacuum Sealing of Silicon MEMS with Measured Q-Factors of 1 Million|
|Keywords: MEMS, vacuum, reliable|
|AUTHOR WITHDREW 8-20-11: This paper details the continued efforts in sub-mTorr vacuum packaging of ultra-high performance MEMS timing and navigation sensors with measured Q-factors of 1 million. Improving the performance of vibratory MEMS such as clock resonators, gyroscopes, and resonant accelerometers is directly related to maximization of the mechanical structure Q-factors. Viscous damping, loss of energy through the substrate, and thermoelastic dissipation are the main mechanisms limiting Q-factors in vibratory MEMS. The UCI MicroSystems Laboratory is developing novel architectures of silicon resonators, FM accelerometers, and gyroscopes which eliminate substrate dissipation and minimize thermoelastic dissipation through the use of proprietary lever mechanisms. Typical measured performance includes 50 ppb frequency stability for resonators, sub-mg bias for accelerometers, and sub-deg/hour bias stability for gyroscopes. A reliable, easily customizable, sub-mTorr vacuum sealing process is being developed in collaboration with SST International to enable practical realization of stand-alone ultra-high performance timing and navigation sensors. First iteration prototypes of vacuum sealed dual mass tuning fork gyroscopes demonstrated Q-factors exceeding 0.5 million after 18 months since the sealing. New, improved designs are currently in work, with sealing and experimental characterization to be completed by Q2 2011. Contained in this paper will be a review of the MEMS transducers design approach, a brief review of the assembly procedure, and the final measured performance results including thermal cycling and accelerated aging measurements. Unique to our sealing approach is a custom glass lid with patterned getter material for ultra-high vacuum sealing. This approach is well suited for a broad range of substrate materials of different die sizes and layouts.|
|Brenton R. Simon, Graduate Student Researcher
University of California, Irvine