Effects of a bottom electrode on feed-through capacitance and electrical transmission of an MEMS resonator

This paper reports on the effects of a bottom electrode on the feed-through capacitance and a performance of a folded-beam MEMS resonator with a push-pull configuration. Generally, feed-through capacitance between driving and sensing ports should be minimized to reduce parasitic signals transmitted from driving ports to sensing ports. However, we found that a folded-beam MEMS resonator with a bottom electrode on a glass substrate has lower performance than a resonator without a bottom electrode, even though feed-through capacitance was reduced. The results of this paper showed that the reduction of the feed-through capacitance of a MEMS resonator is not always proportional to the resonator's performance.