Giant magnetoresistance current sensor

Abstract

The utility model provides a giant magnetoresistance current sensor. The giant magnetoresistance current sensor comprises a current-carrying conductor; the giant magnetoresistance sensor is located on one side of the current-carrying conductor, a nanorod of the giant magnetoresistance sensor is designed to be circular so that a free layer can form a vortex state, magnetic hysteresis is small, current detection repeatability is good, and precision is high.

Description

TECHNICAL FIELD

[0001] The utility model relates to a current sensor especially to a giant magnetoresistance current sensor.

BACKGROUND TECHNIQUE

[0002] The nanometer column of the traditional giant magnetoresistance sensor adopts the design of long strip shape, utilizes the shape anisotropy of the free layer or the free layer of the antiferromagnetic pinning to realize the detection of the magnetic field or the current, and the shortcoming is that the magnetic hysteresis is big, thereby leading to the poor repeatability and precision of the detection of the magnetic field or the current.

[0003] Therefore, it is necessary to provide a kind of scheme to solve the above problems.

UTILITY MODEL CONTENTS

[0004] One of the purposes of the utility model is to provide a kind of giant magnetoresistance current sensor, and the repeatability of its detection of current is good, and precision is high.

[0005] To solve the above problems, the utility model provides a kind of giant magnetoresistance current sensor, it includes: current-carrying conductor;And giant magnetoresistance sensor located at the one side of the current-carrying conductor, wherein the nanometer column of the giant magnetoresistance sensor adopts circular design to make free layer form vortex state.

[0006] Further, the current-carrying conductor includes first leg, second leg and the connecting part of connecting first leg and second leg;The giant magnetoresistance sensor includes first magnetic sensitive area and second magnetic sensitive area, first magnetic sensitive area is located at the one side of first leg, and second magnetic sensitive area is located at the one side of second leg.

[0007] Further, first magnetic sensitive area includes first giant magnetoresistance sensor unit and second giant magnetoresistance sensor unit, second magnetic sensitive area includes third giant magnetoresistance sensor unit and fourth giant magnetoresistance sensor unit, first giant magnetoresistance sensor unit, second giant magnetoresistance sensor unit, third giant magnetoresistance sensor unit and fourth giant magnetoresistance sensor unit are interconnected to form a wheatstone bridge, and the wheatstone bridge only senses the magnetic field generated by the current flowing in the current-carrying conductor.

[0008] Further, each giant magnetoresistance sensor unit includes several circular nanometer columns and several connecting conductors.

[0009] Further, the extension direction of each giant magnetoresistance sensor unit is parallel to the leg of the current-carrying conductor, and several circular nanometer columns and several connecting conductors are alternately arranged.

[0010] Further, each circular nanometer column includes in turn from bottom to top: buffer layer, antiferromagnetic layer, ferromagnetic layer, interlayer, ferromagnetic reference layer, spacing layer, free interlayer, free layer and cover layer.

[0011] Compared with the prior art, the giant magnetoresistance current sensor in the utility model adopts the circular nanometer column design, so that the free layer forms a vortex state, the hysteresis is small, the repeatability of current detection is good, and the precision is high. BRIEF DESCRIPTION OF DRAWINGS

[0012] In order to more clearly illustrate the technical scheme of the embodiments of the utility model, the drawings needed to be used in the embodiment description will be briefly introduced, and obviously, the drawings in the following description are only some embodiments of the utility model, and for those skilled in the art, other drawings can be obtained according to these drawings without creative labor. Among them:

[0013] Figure 1 It is the structure schematic diagram of the giant magnetoresistance current sensor related to the utility model.

[0014] Figure 2 It is the giant magnetoresistance current sensor related to the utility model Figure 1 It is the cross-sectional structure schematic diagram along AA of the giant magnetoresistance current sensor.

[0015] Figure 3 It is the dependence relationship curve of the current range and sensitivity of the giant magnetoresistance current sensor related to the utility model along with the free layer NiFe thickness.

DETAILED DESCRIPTION

[0016] In order to make the above purpose, features and advantages of the utility model more obvious and easy to understand, the utility model will be further described in detail in the following with the drawings and specific embodiments.

[0017] In the description of the utility model, it is understood that the orientation or position relationship indicated by the terms "upper", "lower", "front", "rear", "positive", "back", "left", "right", "vertical", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like is based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, therefore it cannot be understood as a limitation to the utility model.

[0018] Figure 1 It is the structure schematic diagram of the giant magnetoresistance current sensor related to the utility model. Figure 2 It is the giant magnetoresistance current sensor related to the utility model Figure 1 It is the cross-sectional structure schematic diagram along AA of the giant magnetoresistance current sensor. Please refer to Figure 1 And Figure 2As shown, the giant magnetoresistive current sensor 100 includes a current-carrying conductor 102 and a giant magnetoresistive sensor 101 located above it. The current-carrying conductor 102 includes a first leg 102a, a second leg 102b, and a connecting portion 102c connecting the first leg 102a and the second leg 102b. The first leg 102a and the second leg 102b are parallel, and the current direction in the first leg 102a is opposite to the current direction in the second leg 102b. The giant magnetoresistive sensor 101 includes a first magnetically sensitive region 101a and a second magnetically sensitive region 101b. The first magnetically sensitive region 101a is located above the first leg 102a, and the second magnetically sensitive region 101b is located above the second leg 102b. The current-carrying conductor 102 can also be referred to as a U-shaped current-carrying conductor 102, and the U-shape in the current-carrying conductor 102 should be interpreted broadly.

[0019] Of course, depending on the placement Figure 2 The orientation of the giant magnetoresistive current sensor 100 can also be considered as follows: the giant magnetoresistive sensor 101 is located below, to the left, or to the right of the U-shaped current-carrying conductor 102; the first magnetically sensitive region 101a is located below, to the left, or to the right of the first leg 102a; and the second magnetically sensitive region 101b is located below, to the left, or to the right of the second leg 102b. Therefore, to avoid confusion, it can be considered that the giant magnetoresistive sensor 101 is located on one side of the U-shaped current-carrying conductor 102, the first magnetically sensitive region 101a is located on one side of the first leg 102a, and the second magnetically sensitive region 101b is located on one side of the second leg 102b. The giant magnetoresistive sensor 101 and the current-carrying conductor 102 are spaced apart, meaning that the giant magnetoresistive sensor 101 and the current-carrying conductor 102 are not in contact; the giant magnetoresistive sensor 101 and the current-carrying conductor 102 are separated by a predetermined distance or a certain distance.

[0020] The first magnetic sensitive region 101a comprises a first giant magnetoresistance sensor unit 1011a and a second giant magnetoresistance sensor unit 1012a, and the second magnetic sensitive region 101b comprises a third giant magnetoresistance sensor unit 1011b and a fourth giant magnetoresistance sensor unit 1012b. The first giant magnetoresistance sensor unit 1011a, the second giant magnetoresistance sensor unit 1012a, the third giant magnetoresistance sensor unit 1011b and the fourth giant magnetoresistance sensor unit 1012b are interconnected to form a Wheatstone bridge. The magnetic field generated by the current I flowing through the current-carrying conductor 102 in the first magnetic sensitive region 101a is H1, the magnetic field generated by the current-carrying conductor 102 in the second magnetic sensitive region 101b is -H1, and the common-mode magnetic field in the external environment in the first magnetic sensitive region 101a and the second magnetic sensitive region 101b is H0. The Wheatstone bridge only senses the magnetic field [(H1+H0)-(-H1+H0)] / 2=H1 generated by the current I flowing through the current-carrying conductor 102, and is completely insensitive to the external common-mode magnetic field H0.

[0021] Each giant magnetoresistance sensor unit comprises a plurality of circular nanometer pillars 103 and a plurality of connecting conductors 104. The extension direction of each giant magnetoresistance sensor unit is parallel to the leg of the current-carrying conductor 102. The plurality of circular nanometer pillars 103 and the plurality of connecting conductors 104 are arranged alternately.

[0022] The circular nanometer pillar 103 comprises, from bottom to top, a buffer layer 1031 (preferably Ta, Ru or TaN), an anti-ferromagnetic layer 1032 (preferably IrMn, PtMn or FeMn), a ferromagnetic layer 1033 (preferably CoFe), a sandwich layer 1034 (preferably Ru), a ferromagnetic reference layer 1035 (preferably CoFe), a spacer layer 1036 (preferably Cu), a free sandwich layer 1037 (preferably CoFe, with a thickness of 1nm-3nm), a free layer 1038 (preferably NiFe, with a thickness of 50nm-200nm), a cover layer 1039 (preferably Ta, Ru or TaN). The radius of the circular nanometer pillar 103 can be 0.25um-5um, the free layer 1038 forms a vortex state, has small hysteresis, good repeatability and high precision for current detection. The ferromagnetic layer 1033 forms an anti-ferromagnetic coupling with the ferromagnetic reference layer 1035 through the sandwich layer 1034 (as shown by the arrow in the figure).

[0023] Specifically, the first connection end of the first giant magnetoresistance sensor unit 1011a and the first connection end of the third giant magnetoresistance sensor unit 1011b are connected to a power supply end VDD, the first connection end of the second giant magnetoresistance sensor unit 1012a and the first connection end of the fourth giant magnetoresistance sensor unit 1012b are connected to a ground end GND, the second connection end of the first giant magnetoresistance sensor unit 1011a and the second connection end of the fourth giant magnetoresistance sensor unit 1012b are connected to a first voltage output end Vout1, the second connection end of the second giant magnetoresistance sensor unit 1012a and the second connection end of the third giant magnetoresistance sensor unit 1011b are connected to a second voltage output end Vout2, the first connection end of each giant magnetoresistance sensor unit is located on the same side, and the second connection end of each giant magnetoresistance sensor unit is located on the same side. The working principle of each giant magnetoresistance sensor unit and the Wheatstone bridge can refer to the prior art, which is not the focus of the utility model, and will not be described again.

[0024] Please refer to Figure 3 As shown in the figure, the dependence relationship curve 300 of the current range and the sensitivity of the giant magnetoresistance current sensor of the utility model on the thickness of the free layer NiFe: wherein the coupling strength of the current flowing in the U-shaped current-carrying conductor 102 in the magnetic sensitive area is 1.5 G / A, and the radius of the circular nanometer column 103 is 1 um. It can be seen that the current range linearly increases with the increase of the thickness of the free layer NiFe, and the sensitivity decreases with the increase of the thickness of the free layer NiFe.

[0025] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In the present specification, the illustrative description of the above terms is not necessarily for the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, the person skilled in the art can combine and combine different embodiments or examples described in the present specification.

[0026] Although the embodiments of the utility model have been shown and described above, it can be understood that the above-mentioned embodiments are exemplary and cannot be understood as limiting the utility model, and the person skilled in the art can change, modify and modify the above-mentioned embodiments within the scope of the utility model.

Claims

1. A giant magnetoresistive current sensor, characterized in that, It includes: Current-carrying conductor; and A giant magnetoresistive sensor located on one side of the current-carrying conductor, wherein the nanopillars of the giant magnetoresistive sensor are designed in a circular shape so that the free layer forms a vortex state.

2. The giant magnetoresistive current sensor as described in claim 1, characterized in that, The current-carrying conductor includes a first leg, a second leg, and a connecting portion connecting the first leg and the second leg; The giant magnetoresistive sensor includes a first magnetically sensitive region and a second magnetically sensitive region, the first magnetically sensitive region being located on one side of the first leg and the second magnetically sensitive region being located on one side of the second leg.

3. The giant magnetoresistive current sensor as described in claim 2, characterized in that, The first magnetically sensitive region includes a first giant magnetoresistive sensor unit and a second giant magnetoresistive sensor unit, and the second magnetically sensitive region includes a third giant magnetoresistive sensor unit and a fourth giant magnetoresistive sensor unit. The first giant magnetoresistive sensor unit, the second giant magnetoresistive sensor unit, the third giant magnetoresistive sensor unit and the fourth giant magnetoresistive sensor unit are interconnected to form a Wheatstone bridge. The Wheatstone bridge only senses the magnetic field generated by the current flowing through the current-carrying conductor.

4. The giant magnetoresistive current sensor as described in claim 3, characterized in that, Each giant magnetoresistive sensor unit comprises several circular nanopillars and several connecting conductors.

5. The giant magnetoresistive current sensor as described in claim 4, characterized in that, Each giant magnetoresistive sensor unit extends parallel to the leg of the current-carrying conductor, with several circular nanopillars and several connecting conductors arranged alternately.

6. The giant magnetoresistive current sensor as described in claim 4, characterized in that, Each circular nanopillar, from bottom to top, comprises: a buffer layer, an antiferromagnetic layer, a ferromagnetic layer, an interlayer, a ferromagnetic reference layer, a spacer layer, a free interlayer, a free layer, and a capping layer.

7. The giant magnetoresistive current sensor as described in claim 6, characterized in that, The circular nanopillars have a radius of 0.25µm-5µm, and the free layer forms a vortex state with low magnetic hysteresis.

8. The giant magnetoresistive current sensor as described in claim 6, characterized in that, The ferromagnetic layer forms an antiferromagnetic coupling with the ferromagnetic reference layer through the interlayer.

9. The giant magnetoresistive current sensor as described in claim 6, characterized in that, The buffer layer is Ta, Ru, or TaN; the antiferromagnetic layer is IrMn, PtMn, or FeMn; the ferromagnetic layer is CoFe; the interlayer is Ru; the ferromagnetic reference layer is CoFe; the spacer layer is Cu; the free interlayer is CoFe; the thickness of the free interlayer is 1 nm-3 nm; the free layer is NiFe; and the capping layer is Ta, Ru, or TaN.

10. The giant magnetoresistive current sensor as described in claim 6, characterized in that, The thickness of the free layer is 50nm-200nm.

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