An Improved SOI Resonant Pressure Sensor using Atmospheric Packaging*

An improved atmospheric packaged SOI resonant pressure sensor is presented. A special anchor structure using suspended connecting truss is developed to suppress the vertical position shift of the resonator when the diaphragm deflects, and a stress isolating structure is introduced to improve the performance of the resonant pressure sensor. Experimental results show that the vertical position shift of the resonator is reduced to only 7.3% compared with conventional anchor design. Over the full scale pressure range of 3.5–280 kPa, the pressure sensitivity is 10.86 Hz/kPa, with the nonlinearity is 0.0138%FS, the hysteresis error is 0.0047%FS, the repeatability error is 0.0071%FS, and the accuracy is better than 0.02%FS.