Modeling of MEMS capacitive differential pressure sensor

In this paper, modeling of high sensitive capacitive differential pressure sensor (CDPS) structure was proposed. The-working principle of CDPS was explained. Different types of CDPS structure for aircraft altimeter were designed. Polymide square diaphragm membrane is used to sense the pressure. Simulation was carried out for the range of pressure from 116 mbar to 1100 mbar, which is equivalent to aircraft flying altitude. Analysis was done with simulation results for centre deflection sensitivity and capacitive sensitivity for different models of CDPS structure. From the simulated results an improved CDPS models with bossed diaphragm membrane shows linear characteristics. The deflection sensitivity and capacitive sensitivity are 10.912nm/mbar and 3.025fF/mbar respectively.