基于SOI-MEMS工艺的谐振式压力传感器研究

提出了一种电磁激励、差分检测的谐振式MEMS压力传感器，该器件采用低电阻率的SOI器件层单晶硅制作“H”型谐振梁，并作为激励和检测电极。根据对传感器数学模型的分析，利用有限元分析方法优化了传感器结构设计。采用等离子深刻蚀制作传感器结构，并用湿法腐蚀SOI二氧化硅层的方法释放。利用硅-玻璃阳极键合技术，实现了传感器的圆片级真空封装。采用开环扫描检测和闭环自激振荡方式，测定压力传感器的特性。实验结果表明：传感器一致性良好，在500~1100hPa的检测范围内，差分检测灵敏度为14.96Hz/hPa，线性相关系数为0.999996。

Research of a Micromachined Resonant Pressure Sensor Based on SOI Wafer

A micromachined resonant pressure sensor with H-type doubly-clamped beams was proposed based on electromagnetically driven and differentially detection methods. The beams were made of a SOI wafer''s single-crystal silicon device layer with low resistivity, which were also acted as the excited and sensed electrodes instead of commonly used metal layer electrodes. Finite element analysis was utilized to optimize the design of the pressure sensor. The sensor was fabricated by deep reactive ion etching process and buffered oxide etcher release process, and the vacuum package of the sensor was realized by anodic bonding. Experimental results show a sensitivity of 14.96Hz/hPa and linear correlation coefficient of 0.999996 in the range of 500 to 1100hPa.