硅体微机械叉指电容式加速度传感器设计研究

SILICON BULK-MICROMACHINED INTERDIGITATED DIFFERENTIAL CAPACITIVE ACCELEROMETER

提出了一种硅体微机械加工叉指电容式加速度传感器结构，对其工作原理，器件性能优化设计与制作工艺流程进行了分析，得出优化的结构参数。本结构的电容值比ＡＤＸＬ５０加速度传感器大２０倍以上，同时可避免器件与衬底材料的寄生电容。这种结构的传感器对界面电路的要求较低，更便于制出集成化处理电路。

お kind of silicon bulk-micromachined interdigitated differential capacitive accelerometer structure is presented. The operation principle, optimization of the structure design and the fabrication sequence for this accelerometer are also discussed. On the basis of the discussion, a set of optimized structure design parameters is obtained. Compared with the surface micromachined capacitive accelerometer ADXL50, the differential capacitance of this accelerometer can be more than 20 times larger. At the same time, the parasitic capacitance between the device and the substrate can be also avoided with glass adopted as the substrate. Furthermore, there is barely any stress in this device for single crystalline silicon is used as the structure material. The requirements for signal detection circuit of this accelerometer are less demanding, so it is more convenient to fabricate. 