The Study Of The Different Substrate Conditions On The Impact Of Mems Piezoresistive Sensor Performance

In this paper, the develop and wide uses of mems were introduced, and the piezoresistivity was described particularly. Then,the principle of accelerometer was discussed in section 2.The structure of accelerometer was Simulated with ansys, also the modal of the membrane.The differences between different thickness of the membrane was simulated and discussed. The process of the sensor based on piezoresistivity was completed. Three kinds of substrates were used in this experiment. Sheet resistances of piezoresistive area, contact area and protecting area were tested and analysed after the high temperature steps. For piezoresistive areas, there was no difference between the sheet resistances of A# and B# substrates at the beginning of ions implantation, yet differences became obvious gradually after the impurities diffusing under high temperature condition, the dopant concentration of substrate had greater effect on Impurity distribution after diffusing. By comparing the sheet resistances of piezoresistive areas, the substrate of 20~40Ω·cm is the best for the design, this result have already been used in production.