On-chip Feedthrough Cancellation Technique for Enhanced Electrical Characterization of a Piezoelectric MEMS Resonator in Water

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• 作者：Abid Ali^a ; ^{abidali2-c@my.cityu.edu.hk} ; Joshua E.-Y. Lee^a ; ^b
• 关键词：AlN-on-silicon ; MEMS resonator ; Feedthrough cancellation ; Quality factor ; Differential inputs
• 刊名：Procedia Engineering
• 出版年：2016
• 出版时间：2016
• 年：2016
• 卷：168
• 期：Complete
• 页码：1573-1576
• 全文大小：493 K
• 卷排序：168

文摘

In this work, we report a unique on-chip approach of cancelling feedthrough applied to a Thin-film Piezoelectric-on-Silicon (TPoS) MEMS resonator fully immersed in deionized (DI) water to enhance the signal-to-background ratio (SBR) in the context of full electrical characterization. We experimentally validate the proposed technique by demonstrating an SBR as high as 25dB despite a reasonably low quality factor (Q) of 162 and high dielectric constant of water from a reference SBR of 3.45dB. The proposed technique employs a pair of differential inputs where one input actuates the device while the other input cancels feedthrough and targets package-level parasitic elements associated with measuring in water. The resulting net feedthrough capacitance is reduced from 185fF to just 2.04fF in DI water. These results are based on a simple practical setup where the fabricated device is interfaced with a customized printed circuit board (PCB) by wire-bonds.