Fabrication and Characteristics of a SOI Three-Axis Acceleration Sensor Based on MEMS Technology

• Main Authors: Xiaofeng Zhao, Ying Wang, Dianzhong Wen
• Format: Article
• Language: English
• Published: MDPI AG 2019-04-01
• Series: Micromachines
• Subjects: three-axis acceleration sensor; MEMS technology; sensitivity; L-shaped beam
• Online Access: https://www.mdpi.com/2072-666X/10/4/238

A silicon-on-insulator (SOI) piezoresistive three-axis acceleration sensor, consisting of four L-shaped beams, two intermediate double beams, two masses, and twelve piezoresistors, was presented in this work. To detect the acceleration vector (<i>a_x</i>, <i>a_y</i>, and <i>a_z</i>) along three directions, twelve piezoresistors were designed on four L-shaped beams and two intermediate beams to form three detecting Wheatstone bridges. A sensitive element simulation model was built using ANSYS finite element simulation software to investigate the cross-interference of sensitivity for the proposed sensor. Based on that, the sensor chip was fabricated on a SOI wafer by using microelectromechanical system (MEMS) technology and packaged on a printed circuit board (PCB). At room temperature and <i>V</i>_DD = 5.0 V, the sensitivities of the sensor along <i>x</i>-axis, <i>y</i>-axis, and <i>z</i>-axis were 0.255 mV/g, 0.131 mV/g, and 0.404 mV/g, respectively. The experimental results show that the proposed sensor can realize the detection of acceleration along three directions.