The first sub-deg/hr bias stability, silicon-microfabricated gyroscope

The first sub-deg/hr bias stability gyroscope is fabricated in single crystal silicon using the SBM (sacrificial bulk micromachining) process. The quadrature error is a major concern in MEMS gyroscopes for high performance. To minimize the quadrature error, the fabricated gyroscope has a very flat bottom surface, which gives a highly symmetrical proof mass, and springs, which, in turn, provide high performance levels with significantly reduced quadrature error. The fabricated gyroscope has a bandwidth of 58 Hz, and 4-hr bias stability of 0.3 deg/hr.