Based On The Anisotropic Magnetoresistance Effect Of Integrated Sensor Design And Preparation

With the rapid development of the Internet of Things technology,the idea of the Internet of everything and related technologies of intelligent control have been widely applied in all walks of life.In the Internet of Things system,sensors are very important components,which can sense a variety of external signal changes.Nowadays,how to prepare high sensitivity,high stability and low cost sensor has become a key problem in sensor technology.Magnetic sensors based on anisotropic magnetoresistance(AMR)effect are widely used in a variety of applications because of their low cost,high sensitivity,ease of application,high stability,and integrability.This thesis focuses on the optimal growth process parameters of NiCo thin film,and uses these parameters to design and prepare a linear magnetic field sensor based on Ni Co thin film,and then builds an application system based on linear magnetic field sensor to realize the acquisition and further processing of magnetic field signals.The results show that when the thickness of NiCo thin films prepared by magnetron sputtering is 80 nm,the AMR effect is the strongest,and the corresponding AMR value is up to 2.96%.At the same time,it is found that growth under magnetic field and annealing under magnetic field can improve the performance of the film,and no annealing without magnetic field growth performance is better.In addition,the AMR effect of nanothick Pt intercalation can be increased from 2.83% to 3.31%.Dy intercalation can reduce the coercivity of Ni Co film from 10 Oe to 5 Oe.Secondly,the shape and size of Wheatstone bridge and barber electrode are also designed in this thesis.The bending period of a single arm of Wheatstone bridge is calculated to be 7,and the optimal barber electrode width and electrode spacing are obtained to be 5 μm by COMSOL Multiphysics simulation software.The optimal electrode Angle is 40° between the electrode and x axis.Then,according to the designed parameters,the corresponding linear magnetic field sensor is drawn and prepared.The sensor has a sensitivity of 0.114 m V/V/Gs and a linear interval width of 28 Oe.Finally,an application system based on linear magnetic field sensor is designed and built.The system processes the analog signal output by the sensor,and transmits the digital signal obtained from the processing to the Field Programmable Gate Array(FPGA),which is displayed by the digital tube.At the same time,it can also be displayed and stored through the upper computer,and the sensor parameters can be corrected to eliminate the error brought by different installation environment.In general,the research results of this thesis are of great significance for the preparation of high performance and low cost magnetic integrated sensor and its application system,and also provide a valuable reference for the research in related fields.