Linear anisotropic magnetoresistive sensor and realization method thereof

Abstract

The invention relates to a linear anisotropic magnetoresistive sensor and a realization method thereof, and belongs to the technical field of a magnetic material and a device. The anisotropic magnetoresistive sensor sequentially comprises a bottom electrode, a substrate, a top electrode and an anisotropic magnetoresistive sensing unit film from bottom to top. The linear anisotropic magnetoresistive sensor is characterized in that the substrate is a piezoelectric substrate; through the voltage exertion between the bottom electrode and the top electrode, the piezoelectric substrate generates thestress and realizes the magnetostriction effect through the magnetic film; the goal of forming a 45-degree included angle between the initial magnetic moment direction of the anisotropic magnetoresistive sensing unit and the current is achieved. On the basis of the magnetoelectric coupling effect, the stress generated by the piezoelectric substrate is used for achieving the magnetostriction effect through the magnetic film; the goal of forming the 45-degree included angle between the initial magnetic moment direction of the linear anisotropic magnetoresistive sensing unit and the current is finally achieved; the advantages of simple structure, low process difficulty, low power consumption and the like are realized; the preparation of the linear sensor can be simplified.

Description

technical field [0001] The invention belongs to the technical field of magnetic materials and components, and relates to magnetic sensing technology, in particular to a linear anisotropic magnetoresistance sensor and a realization method thereof. Background technique [0002] Anisotropic magnetoresistance sensors are various sensors based on the anisotropic magnetoresistance (AMR) effect of magnetic metal films. Because of the advantages of simple materials, low price, and high stability, AMR magnetoresistive sensors are currently the most important member of the magnetic sensor family, and have a wide range of applications and markets in the detection of magnetic fields, currents, and positions. [0003] The size of the anisotropic magnetoresistance can be expressed as: R=R ⊥ +ΔRcos 2 α, where ΔR=R / / -R ⊥ (R / / is the resistance value when the magnetic moment of the magnetic material is parallel to the current; R ⊥ is the resistance value when the magnetic moment of ...

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Problems solved by technology

From the above analysis, it can be seen that when the Baber electrode is used, it is necessary to carry out the photolithography preparation of the Baber electrode on the basis of the completion of the magnetic metal film plating, which requires high alignment accuracy of the photolithography, and increases the sensor design. The process is difficult; when using permanent magnet bias, it is necessary to add a permanent magnet to the sensor, which increases the overall volume and weight of the device, which is not conducive to the miniaturization of the device; while the current bias method needs to be plated on the film surface of the magnetoresistive element The insulation layer is prepared with a layer of metal conductive film, which not only increases the difficulty of the preparation process, but also because when the shape anisotropy field of the magnetic metal film is large, the magnetic field generated by the current bias layer is small and cannot make the magnetic moment deflect to 45° position, it is difficult to reach the optimal operating point, and because the output signal is shunted, the signal amplitude is reduced, which reduces the AMR effect

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