Han Xiangguang, Mao Qi, Zhao Libo, Li Xuejiao, Wang Li, Yang Ping, Lu Dejiang, Wang Yonglu, Yan Xin, Wang Songli, Zhu Nan, Jiang Zhuangde
State Key Laboratory for Manufacturing Systems Engineering, International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technologies, Xi'an Jiaotong University, 710049 Xi'an, China.
School of Mechanical Engineering, Xi'an Jiaotong University, 710049 Xi'an, China.
Microsyst Nanoeng. 2020 Nov 16;6:95. doi: 10.1038/s41378-020-00207-0. eCollection 2020.
In this paper, a novel resonant pressure sensor is developed based on electrostatic excitation and piezoresistive detection. The measured pressure applied to the diaphragm will cause the resonant frequency shift of the resonator. The working mode stress-frequency theory of a double-ended tuning fork with an enhanced coupling beam is proposed, which is compatible with the simulation and experiment. A unique piezoresistive detection method based on small axially deformed beams with a resonant status is proposed, and other adjacent mode outputs are easily shielded. According to the structure design, high-vacuum wafer-level packaging with different doping in the anodic bonding interface is fabricated to ensure the high quality of the resonator. The pressure sensor chip is fabricated by dry/wet etching, high-temperature silicon bonding, ion implantation, and wafer-level anodic bonding. The results show that the fabricated sensor has a measuring sensitivity of ~19 Hz/kPa and a nonlinearity of 0.02% full scale in the pressure range of 0-200 kPa at a full temperature range of -40 to 80 °C. The sensor also shows a good quality factor >25,000, which demonstrates the good vacuum performance. Thus, the feasibility of the design is a commendable solution for high-accuracy pressure measurements.
本文基于静电激励和压阻检测开发了一种新型谐振压力传感器。施加在膜片上的被测压力会导致谐振器的谐振频率发生偏移。提出了一种带有增强耦合梁的双端音叉的工作模式应力-频率理论，该理论与仿真和实验结果相匹配。提出了一种基于处于谐振状态的小轴向变形梁的独特压阻检测方法，并且易于屏蔽其他相邻模式输出。根据结构设计，制造了在阳极键合界面具有不同掺杂的高真空晶圆级封装，以确保谐振器的高质量。压力传感器芯片通过干法/湿法蚀刻、高温硅键合、离子注入和晶圆级阳极键合制造而成。结果表明，在-40至80°C的全温度范围内，所制造的传感器在0-200kPa的压力范围内具有约19Hz/kPa的测量灵敏度和0.02%满量程的非线性度。该传感器还具有大于25,000的良好品质因数，这表明其具有良好的真空性能。因此，该设计的可行性是高精度压力测量的一个值得称赞的解决方案。
