This paper presents a high-sensitivity micromachined resonant differential pressure sensor based on bulk silicon. The sensor includes a sensing unit made of a SOI wafer, which is vacuum packaged by a glass-on-silicon (GOS) wafer. More specifically, two resonators located in the SOI device layer were coupled to the GOS glass layer and deployed on the central and side areas of the pressure-sensitive diaphragm respectively, enabling differential outputs. According to the relevant theory of elasticity, the differential pressure sensitivity is high, where the conversion efficiency of the differential pressure to resonators stress is improved by the special cap design, large pressure-sensitive diaphragm and narrow resonators. The developed differential pressure microsensors were manufactured leveraging well-established microfabrication steps including lithography, etching and boning. Characterization of the micromachined sensors was conducted, reporting averaged differential pressure sensitivities of 1) −143.17 Hz/kPa (~2051 ppm/kPa) and a linear correlation coefficient of 0.999992 under a static pressure of 110 kPa and a temperature range from −°C to 40°C; 2) −143.36 Hz/kPa (~2051 ppm/kPa) and a linear correlation coefficient of 0.999997 under a static pressure range from 110 kPa to 250 kPa and a temperature of 25°C. Compared to previous study, the high differential pressure sensitivity of the sensor can pave ways for the subsequent high-precision measurement of differential pressures, which can be used to measure micro differential pressure in the field of nuclear power.

中文翻译：

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基于体微加工的高灵敏度谐振压差微传感器

本文提出了一种基于体硅的高灵敏度微机械谐振压差传感器。该传感器包括一个由SOI晶片制成的传感单元，该传感单元由硅上玻璃（GOS）晶片真空封装。更具体地说，位于SOI器件层中的两个谐振器耦合到GOS玻璃层，并分别部署在压敏膜片的中央和侧面区域，从而实现差分输出。根据相关的弹性理论，压差灵敏度很高，通过特殊的盖设计，大的压敏膜片和窄的谐振器可以提高压差到谐振器应力的转换效率。开发的压差微传感器是利用完善的微制造步骤制造的，这些步骤包括光刻，蚀刻和去键合。对微机械传感器进行了表征，报告在110 kPa静压力和-°C的温度范围内，平均压差灵敏度为1）-143.17 Hz / kPa（〜2051 ppm / kPa），线性相关系数为0.999992。到40°C; 2）在110 kPa至250 kPa的静压范围和25°C的温度下，−143.36 Hz / kPa（〜2051 ppm / kPa）和线性相关系数为0.999997。与之前的研究相比，传感器的高差压灵敏度可以为后续的高精度差压测量铺平道路，