The technological concept of a single chip three axes surface micromachined accelerometer, the sensor design and measurement results for the related single axes accelerometers are presented. The mechanical structure of the sensor was fabricated using polysilicon layers with a thickness of 10μm, deposited by a high rate deposition process. The complete fabrication process for the sensor realization was developed under consideration of the requirements for an integration into a commercial BiCMOS process. The sensors for detection of acceleration parallel to the chip surface (x and y direction) are designed as interdigital finger structures forming differential capacitors, where the moveable fingers are mounted on a movable mass and the fixed electrodes are anchored on the substrate. The z-axes sensor for detection of accelerations perpendicular to the chip surface is designed as a pendulum type structure.
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