Simulation Analysis Of SOI Pressure Sensor Structure

The pressure sensor is used to measure the ambient pressure or external pressure value,it can be converted to an electrical signal output,at present,the sensors have many applications in the field of biomedical,aerospace control,and industrial detection.Pressure sensors can be divided into two major categories of piezoresistive pressure sensor and capacitive pressure sensor.A piezoresistive pressure sensor is by using converting the changing of resistance caused by the outside pressure value into electrical signals,a capacitive pressure sensor is by converting capacitance variations under the outside pressure value into electrical signals,each has advantages and disadvantages.As a result of the piezoresistive pressure sensor technology simple,convenient,it widely used at present.The traditional piezoresistive pressure sensor is using top-down technique.Firstly,implanting ion into the top surface of monocrystalline silicon to form the pizeoresistors,then anisotropic etching the silicon substrate from the bottom to form a thin movable membrane.The simulation analysis plays an important role in a whole flow of the design work for the sensor.The simulations have been given to analyze the performance of the pressure sensor.Based on the results,the theoretical model and the measurement results can be verified,the design of the structure can be optimized.The simulation results show that the simulation results can verify the theoretical model.This simulation model is suitable for MEMS piezoresistive pressure sensor,especially for SOI high temperature pressure sensor.The main jobs are as follows.Firstly,the basic structure and theoretical model of the piezoresistive pressure sensor has been proposed.Secondly,the modeling and simulation analysis with ANSYS finite element software has been carried out on the structure of the sensor,the relationship between the loaded pressure and the stress distribution and displacement of the membrane under different structure dimensions has been analyzed.Thirdly,the output of the pressure sensor of the structure is modeled and simulated,and the relationships between the output of the Wheatstone bridge with the loaded pressure have been simulated.Fourthly,the relationship between the output of the Wheatstone bridge with the loaded pressure under the different temperatures and structural dimensions have been simulated.