一种具有“8悬臂梁-质量块”结构的新型硅微加速度计

Design and Fabrication of an Accelerometer with Novel “8-Beams/Mass” Structure

提出了一种具有“8悬臂梁-质量块”结构的新型三明治式硅微机械电容式加速度计,用微机械加工工艺在(111)硅片上制作出了具有信号输出的器件.该加速度计的惯性质量块由同一(111)硅片上下表面对称分布的8根悬臂梁支撑.这些悬臂梁是利用(111)硅在KOH溶液中的各向异性腐蚀特性结合深反应离子刻蚀(DRIE)实现的,其尺度精确可控,保证了结构的对称性.该加速度计的谐振频率为2·08kHz,品质因子Q为21·4,灵敏度为93·7mV/g.

A new micro-silicon capacitive accelerometer with novel ＂8-beams/mass＂ structure was designed and fabricated by applying a micro-machining process to （111） silicon wafer. The proof mass of this accelerometer is supported by eight suspension beams located symmetrically on the top/bottom surface of a （111） silicon wafer. By using an extremely slow rate of Si （111） plane etching in anisotropic KOH,along with DRIE and other MEMS processes,the dimension of these beams can be accurately controlled,and the symmetry of the ＂8-beams/mass＂ structure can be achieved. The performance of the accelerometer is measured with a typical resonance frequency of 2. 08kHz,quality factor of 21.4,and sensitivity of 93. 7mV/g.