Bulk micromachined angular rate sensor based on the 'butterfly'-gyro structure

Abstract

The principle of the butterfly-gyro was first demonstrated with a large anisotropically etched structure in bulk silicon. Now the same principle has been used to develop a much smaller structure (9.6 mm/sup 2/). The new sensor chip is ICP-etched in bulk silicon and anodically bonded to form a triple stack (glass/Si/glass) structure. Together with an ASIC the sensor typically shows a noise level of 0.3 /sup o///sub s/ over 50 Hz bandwidth and a zero-rate offset (ZRO) less than 50 /sup o///sub s/.