Design and characterization of an integrated multifunction micro sensor

This paper describes the design and characterization of an integrated sensor fabricated on the silicon on insulator wafer by micro electro mechanical systems technology. The integrated sensor is comprised of a tri-axis accelerometer, an absolute pressure sensor and a spreadingresistance temperature (SRT) sensor. The optimal size of the sensor structure, natural frequency and cross interference of these three sensors were simulated and determined by finite element analysis. The accelerometer with the cross structure has high sensitivity, good linearity and high response frequency proved by the static and dynamic experiments. The zero-drift, thermal zero-drift and thermal sensitivity of the accelerometer and absolute pressure sensor were also tested. The arrangement of SRT sensor with the wave structure was designed in detail. The optimal location of the SRT sensor was at the edge of chip to avoid stress interference. The integrated sensor with low cost, low mutual interference, smaller volume and good performance can be applied in mobile device, small military plane without driver and some other situations for environmental monitoring.