Design And Principle Of On-chip Temperature Sensitive Resonant Pressure Sensor Based On Dual-piezoresistive Differential Detection

MEMS micro-pressure sensor is one of the earliest commercial products,which has the highest precision for pressure measure instruments,it is used in aerospace aircraft atmospheric data collection,weather monitoring and industrial control and so on,because of its high precision,good stability,good anti-jamming,digital output and other advantages.At present,in view of the silicon micro-resonant pressure sensor of the many benefits and demand,it has been research focus of domestic laboratory.However,complex structural design and manufacturing processes often take a long time for the development of such sensors.At present,domestic has not yet been able to achieve such a mass production of sensors.Based on systematic study of various silicon resonant pressure sensor,this paper presents a novel double-membrane electronically excited and piezoresistive detected resonant pressure sensor,which can sensitive pressure and temperature information simultaneously and presents the whole scheme and stricture design of the sensor.In order to improve the overall performance of the sensor,we determine the optimal piezoresistive detection direction,and present an optimal design scheme to solve the problem of improving the pressure sensitivity and reducing the temperature sensitivity of the resonant pressure sensor.The performance of the sensor has been simulated by finite element simulation,including the pressure sensitivity response,the temperature response sensitivity response,the out-of-plane displacement and the impact load response of the sensor.Finally,based on the finite element simulation analysis,the surface about pressure,temperature and frequency is obtained,and the temperature compensation is carried out by the least squares method.The theoretical precision of the sensor can reach 0.0005%FS.On the basis design of the sensor,the whole process of the sensor is designed,the key technology in the sensor manufacturing is studied,and the related key technology is researched.The main research contents are as follows:The deep silicon etching process experiment is carried out to determine the best process parameters in sensor sensitive film's preparation.Dry and wet activation method for silicon and silicon oxide bonding with the bonding yield is more than 90 percentages and the bonding strength is better than 20 MPa.Finally,the chemical and mechanical methods are used to polish the resonant layer of the device,and the thickness of the resonant layer is precisely controlled.