The Design of a High Precision Capacitive Pressure Sensor Based on Comb Electrode

MEMS capacitive sensors promise wide applications in the field of high precision pressure sensing because of their low temperature drift, low power consumption and high precision. Based on the deformation principle of diaphragm under pressure, we present the design and fabrication process of a novel high precision MEMS capacitive pressure sensor, which consists of island-diaphragm composited structure and comb electrode. Furthermore, a finite element simulation analysis is conducted to demonstrate the excellent performance of the sensor. The simulation results show that the capacitance output non-linearity in load pressure range of 75-125 kPa and 125-200 kPa are 0.083%FS and 0.074%FS, with the sensitivities of 9.3 fF/kPa and 10.6 fF/kPa, respectively.