Design and fabrication of a torsional z-axis capacitive accelerometer with novel comb capacitor

A novel comb capacitor, in which the fixed and movable fingers have different height at one side, is proposed. The comb capacitor can be used to measure torsional out-of-plane movement through a differential method. Using this kind of comb capacitor, a bulk micromachined torsional z-axis accelerometer is designed. The accelerometer is fabricated using a silicon/glass wafer bonding and deep reactive ion etching process, in which a composite etching mask technique is used to realize the novel comb structure.