Modeling and Analysis of Thin Film PolySi Diaphragm Pressure Sensor

Abstract

Micromachining technology has greatly benefited from the success of developments in implantable biomedical micro devices. In this paper, a simulation solution of micro-electro mechanical systems (MEMS) capacitive pressure sensor operating for biomedical applications in the range of 20–400 mmHg was designed. Employing the micro electro mechanical systems (MEMS) technology, high sensor sensitivities and resolutions have been achieved. This paper provides initial data on the design and simulation of such a sensor. Capacitive sensing uses the diaphragm deformation-induced capacitance change. The sensor composed of a rectangular Polysilicon diaphragm that deflects due to pressure applied over it. Applied pressure deflects the 2 μm diaphragm changing the capacitance between the Polysilicon diaphragm and gold flat electrode deposited on a glass pyrex substrate. The simulation of the MEMS capacitive pressure sensor achieves good linearity and large operating pressure range. The static and thermo electro mechanical analysis was performed. The FEA modeling and simulated data results were generated. The capacitive response of the sensor performed as expected according to the relationship of the spacing of the plates. Intellisuite software is used for modeling and simulation of MEMS capacitive pressure sensor to optimize the design, improve the performance and to reduce the time of fabricating process of the device.