ELECTROELASTIC SIMULATION OF A PIEZORESISTIVE PRESSURE SENSOR

The transport properties of the silicon crystal are sensitive, to some extent, to mechanical perturbations; this allows for integrating mechanical sensors, together with the sensing circuitry, within a silicon chip by using an almost standard IC technology. In this paper, the numerical simulation of a silicon pressure sensor, based on the piezoresistive effect, is described. The simulated transducer is made of a thin silicon diaphragm, on top of which a four-resistor bridge is diffused. For a given pressure, the distribution of the stress components over the diaphragm is fed to the program, which then computes the sensor response depending on its geometrical and physical features. To this purpose, an anisotropic, stress-dependent mobility model has been introduced into the device simulator HFIELDS-3D.