High-Performance Single-Side Fabricated (111)-Silicon Dual-Cantilever Accelerometer with Squeeze-Film Air Damping Modulation

• Published in: Shanghai jiao tong da xue xue bao Vol. 28; no. 2; pp. 197 - 206
• Main Authors: Jiao, Ding, Ni, Zao, Wang, Jiachou, Li, Xinxin
• Format: Journal Article
• Language: English
• Published: Shanghai Shanghai Jiaotong University Press 01.04.2023; Springer Nature B.V; State Key Laboratory of Transducer Technology,Shanghai Institute of Microsystem and Information Technology,Chinese Academy of Sciences,Shanghai 200050,China%School of Microelectronics,University of Chinese Academy of Sciences,Beijing 100049,China
• Subjects: Accelerometers; Architecture; Cantilever bridges; Cantilevers; Computer Science; Damping; Electrical Engineering; Engineering; Life Sciences; Materials Science; Micromachining; Modulation; Nonlinear systems; Original Paper; Resonant frequencies; Sensitivity; Silicon; Stress concentration; Wheatstone bridges; micromachining; 悬臂梁; 微机械; A; 压膜阻尼; cantilever; 加速度计; squeeze-film damping; 压阻效应; accelerometer; piezoresistance; TN 389
• ISSN: 1007-1172; 1674-8115; 1995-8188
• DOI: 10.1007/s12204-021-2288-2

This study proposes a novel design and micromachining process for a dual-cantilever accelerometer. Comb and curved-surface structures are integrated into the sensing structure to modulate the squeeze-film damping, thus effectively optimizing the response frequency bandwidth. Owing to the high stress concentration on the dual-cantilever integrated with a fully sensitive piezoresistive Wheatstone bridge, a high sensitivity to acceleration is achieved. In addition, the dual-cantilever accelerometer is fabricated using a specifically developed low-cost and high-yield (111)-silicon single-side bulk-micromachining process. The test results show that the proposed dual-cantilever accelerometer exhibits a sensitivity of 0.086–0.088 mV/ g /3.3 V and a nonlinearity of ±(0.09%–0.23%) FS (full-scale). Based on dynamic characterization, an adequate frequency bandwidth of 2.64 kHz is verified. Furthermore, a resonant frequency of 4.388 kHz is measured, and a low quality factor ( Q ) of 7.62 is obtained, which agrees well with the design for air-damping modulation. The achieved high performance renders the proposed dual-cantilever accelerometer promising in applications such as automotive and consumer electronics.