A y-axis SOI-MEMS gyroscope with a zigzag-shaped Z-electrode supported by three-dimensionally-intersected Z-beams

The present paper describes a novel y-axis SOI-MEMS gyroscope with a zigzag-shaped Z-electrode (ZSZ) for detecting the roll rate. The proposed gyroscope is three-dimensionally (3D) structured by fabricating double-sided bulk silicon layers of an SOI substrate. The ZSZ supported by 3D-intersected Z-beams has a parallel-plate structure for differentially sensing z-directional capacitive changes. As a proof mass, it is electrostatically vibrated by a 200·m-thick bottom-layer drive comb. The fabricated gyroscope was evaluated at 100 Pa. The measured sensitivity was 62.3 aF/(°/s) with a nonlinearity of less than 0.36% for a full scale of 360°/s. The test results demonstrate that the proposed y-axis gyroscope with the structurally differential ZSZ works for detecting the roll rate.