Capacitive pressure microsensor fabricated by bulk micromachining and sacrificial layer etching

A new capacitive silicon pressure sensor fabricated by a combination of bulk and surface micromachining is presented. The sensor is composed of a polysilicon membrane that deflects due to the pressure difference applied over it. Its main advantages are a simple fabrication process and an efficient integrability with other devices. The behaviour of the sensor, obtained by mathematical modeling of the membrane deflection is presented, along with the numerical simulations that provide the characteristic curves. From these results, a study on how geometry affects sensor performance is deduced. Results obtained are in good agreement with previous similar devices