Research On MEMS Magnetic Sensor Based On Magnetostrictive/Piezoelectric Effect

Magnetoelectric sensors have a good application prospect in magnetic field detection,magnetic imaging technology,and microwave technology because of low fabrication cost,high sensitivity,high resolution,and easy integration.After years of development,significant progress has been made.Piezoelectric materials used in magnetoelectric sensors are usually insulating materials with poor electronic conductivity.So their application is limited for electronic sensors.In recent years,piezoelectric semiconductors represented by zinc oxide and gallium nitride have attracted much attention due to the excellent performance of combining piezoelectric and semiconductor properties.Two magnetoelectric sensors based on piezoelectric semiconductor materials are proposed in this study.One is a Schottky junction magnetoelectric sensor,and the other is a piezoelectric tunnel magnetoelectric sensor.Meanwhile,the performance of two-dimensional material SnS₂,which also has piezoelectric semiconductor properties,is studied in this paper.In this study,the performance of the two sensors was simulated using the COMSOL Multiphysics coupling simulation software.The characteristics of the magnetoelectric sensor under invariable magnetic field,alternating magnetic field and resonance state were simulated,respectively.The magnetoelectric sensor was optimized based on the simulated results.Then fabrication process was determined.The response of piezoelectric tunneling magnetoelectric sensors to the magnetic field was characterized with the built test platform.The results show that magnetoelectric sensor with the thinner the insulating layer has better response in the magnetic field.The maximum current change rate of piezoelectric tunneling magnetoelectric sensor is0.12μA/m T and 1.27μA/m T for Schottky junction magnetoelectric sensor,respectively.Therefore,both sensors had an apparent response to the magnetic field.The response of the device to the magnetic field was enhanced with the increased bias voltage,especially for Schottky junction sensors.Mn-doped SnS₂ nanopowders with different Mn concentrations were synthesized by hydrothermal method.The structure,morphology,and magnetism of the as-obtained samples were thoroughly described.For Mn-doped SnS₂,the enhanced paramagnetic ordering and weak ferromagnetic ordering were observed,which may be caused by Mn atoms in and between layers.This work suggests that the two-dimensional SnS₂ doped with Mn atom has potential applications electronic sensors.Two types of sensors were designed and fabricated after simulations in the study.And the result shows the current has response to magnetic field,which provides reference for the application of piezoelectric semiconductors in magnetic sensors.