Vibrating micromechanical resonators with solid dielectric capacitive transducer gaps
Vibrating micromechanical resonators with solid dielectric capacitive transducer gaps
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DOI：
10.1109/freq.2005.1573914
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发表时间：
2005-08
期刊：
影响因子：
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通讯作者：
Yu-Wei Lin;Sheng-Shian Li;Yuan Xie;Z. Ren;C. Nguyen
中科院分区：
文献类型：
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作者：
Yu-Wei Lin;Sheng-Shian Li;Yuan Xie;Z. Ren;C. Nguyen
基于VHF和UHF MEMS的振动微机械谐振器配备有新的固体电介质（即，在160 MHz频率下，已经证明了电容式换能器间隙取代先前使用的气隙，Q值约为20，200，与气隙谐振器相当，在类似频率和偏置条件下，动电阻（Rx）小8倍以上。这种程度的动态电阻降低不仅通过由固体填充的电极到谐振器间隙提供的更高的介电常数来实现，而且通过实现比空气间隙更小的固体间隙的能力来实现。正确的介电材料的这些优点现在可以允许电容转换的谐振器与片外组件（例如，天线）而不需要高电压。除了较低的动电阻之外，使用填充的介电换能器间隙提供了优于气隙变化的许多其他益处，因为它（a）更好地稳定谐振器结构以抵抗冲击和颤噪;（B）消除了颗粒进入电极到谐振器气隙的可能性，该颗粒进入电极到谐振器气隙会造成潜在的可靠性问题;（c）通过消除气隙器件所需的困难的牺牲释放步骤而大大提高了制造成品率;以及（d）潜在地允许更大的微机械电路（例如，由互连的谐振器组成的带通滤波器）通过稳定组成的谐振器
VHF and UHF MEMS-based vibrating micromechanical resonators equipped with new solid dielectric (i.e., filled) capacitive transducer gaps to replace previously used air gaps have been demonstrated at 160 MHz, with Q's ~ 20,200 on par with those of air-gap resonators, and motional resistances (Rx's) more than 8times smaller at similar frequencies and bias conditions. This degree of motional resistance reduction comes about via not only the higher dielectric constant provided by a solid-filled electrode-to-resonator gap, but also by the ability to achieve smaller solid gaps than air gaps. These advantages with the right dielectric material may now allow capacitively-transduced resonators to match to the 50-377 Omega impedances expected by off-chip components (e.g., antennas) in many wireless applications without the need for high voltages. In addition to lower motional resistance, the use of filled-dielectric transducer gaps provides numerous other benefits over the air gap variety, since it (a) better stabilizes the resonator structure against shock and microphonics; (b) eliminates the possibility of particles getting into an electrode-to-resonator air gap, which poses a potential reliability issue; (c) greatly improves fabrication yield, by eliminating the difficult sacrificial release step needed for air gap devices; and (d) potentially allows larger micromechanical circuits (e.g., bandpass filters comprised of interlinked resonators) by stabilizing constituent resonators as the circuits they comprise grow in complexity