Research On Two-dimensional Magnetic Field Sensor Based On Magnetoresistance Effect

In this paper,a magneto-resistive two-dimensional magnetic field sensor structure based on magnetron sputtering and stripping process is proposed.The structure is mainly composed of eight giant magnetoresistances connect to form two pairs of Wheatstone bridges.The magnetoresistive resistor is a multilayer film structure fabricated on a SiO₂/Si substrate by magnetron sputtering.Each multi-layer film structure consists of four parts:a substrate layer?SiO₂/Si?,a bottom electrode Al layer,a?Co/Cu/Co?_n multilayer film layer,and an Al top electrode layer.Based on the magnetoresistance effect of the multilayer film material,when a magnetic field is applied,the resistance of the resistance strip changes with the change of the magnetic field B,resulting in the Wheatstone bridge losing balance and generating an output signal to realize the detection of the magnetic field.On this basis,through the optimization of geometry and process parameters,the chip layout of four kinds of two-dimensional magnetic field sensors is designed using the integrated circuit layout design software L-Edit,and the high-resistance single-crystal silicon substrate is thermally oxidized by magnetron sputtering.The?Co/Cu/Co?n multi-layer film was prepared and the sensor chip was completed using a lift-off process.The non-magnetized package of the chip was achieved by the ultrasonic welding of inner leads.At room temperature,the magnetic properties of a two-dimensional magnetic field sensor based on magnetoresistance effect were studied by using a high-precision magnetic field generator.The results show that when the power supply voltage V=5.0V,the magnetic sensitivity in the x-direction and y-direction in the two-dimensional magnetic field sensor is 65?V/Gs and 35?V/Gs,respectively,in the magnetic field range of 0.1Gs¹Gs.The experimental results show that the magnetoresistance effect magnetic field sensor can measure two-dimensional magnetic field.