Simulation and Modeling of a High Sensitivity Micro-electro-mechanical Systems Capacitive Pressure Sensor with Small Size and Clamped Square Diaphragm

This paper proposes a Micro-electro-mechanical (MEMS) capacitive pressure sensor that relies on the movable electrode displaced like a flat plate equal to the maximum center deflection of diaphragm. The diaphragm, movable electrode and mechanical coupling are made of polysilicon, gold and Si3N4, respectively. The fixed electrode is gold and the substrate is Pyrex glass. This proposed method increased the effective surface of capacitor and the displacement of movable electrode. The size of this sensor is 250×250 µm2 and the thickness of diaphragm is 1µm with 1 µm air gap. According to the results the sensitivity of sensor is 58.5