Analysis of Sensitivity and Linearity of SiGe MEMS Piezoresistive Pressure Sensor

In this paper a surface micromachined MEMS Piezoresistive pressure sensor was designed. A simulation programs were developed to predict the sensitivity and linearity behavior of the piezoresistive pressure sensor. Based on the small and large deflection theory the diaphragm performances were analyzed. Different diaphragm shape, pressure range, placement of resistors and the properties of the resistors were considered during the analysis. The output response of the pressure sensor was also found as a function of temperature and pressure. It was found that silicon germanium gave better sensitivity and less linearity error. The analysis showed that sensitivity and linearity are influenced by diaphragm thickness and length of the sensing resistor used in the diaphragm of the Piezoresistive pressure sensor. It was found that the sensitivity of 5.2mV/V can be achieved for silicon germanium