TMR magnetic sensor

Abstract

The application relates to a TMR magnetic sensor, comprising: a plurality of inclined structures, each inclined structure being arranged along a first axis and comprising a first inclined surface and a second inclined surface symmetrically arranged along the first axis; the first magnetic induction pairs are used for inducing a third-axis magnetic field, each first magnetic induction pair comprises a first magnetic resistance element and a second magnetic resistance element, and the first magnetic resistance elements and the second magnetic resistance elements are formed by combining the same number of magnetic tunnel junctions in the same mode; the magnetic tunnel junctions of the first magnetic resistance element and the second magnetic resistance element are respectively arranged on a first inclined surface and a second inclined surface which are of an inclined structure and have the same axis; the magnetic tunnel junctions of the first magnetoresistive element and the second magnetoresistive element have initial magnetization directions along a first axis and have the same positive and negative, the magnetic tunnel junctions of the first magnetoresistive element and the second magnetoresistive element have pinning directions along the inclined planes, the components of the pinning directions on the second axis are opposite in positive and negative, and the components of the pinning directions on the third axis are the same in positive and negative. The cross-axis interference can be reduced, and the detection anti-interference capability is improved.

Description

Technical Field

[0001] This application relates to the technical field of magnetic field induction devices, and particularly to a TMR magnetic sensor. Background Art

[0002] Magnetic sensors based on magnetic tunnel junctions (MTJs) have the advantages of large resistance change rate, high sensitivity, low power consumption, good temperature characteristics, and strong anti-interference ability. They mainly utilize the tunnel magnetoresistance (TMR) effect of multi-layer magnetic film materials to achieve the effect that the film resistance changes with the magnitude and direction of the external magnetic field. However, TMR magnetoresistive elements can only perform in-plane magnetic field induction. In order to enable TMR magnetoresistive elements to detect out-of-plane magnetic fields, traditional magnetic sensors usually need to deposit TMR magnetic thin films on slopes and then etch to form magnetic tunnel junctions, but there will be cross-axis interference due to process errors, resulting in low anti-interference ability for detection. Summary of the Invention

[0003] Based on this, it is necessary to provide a TMR magnetic sensor that can improve the anti-interference ability of detection in view of the above problems.

[0004] A TMR magnetic sensor includes:

[0005] A plurality of inclined structures, each of the inclined structures is arranged along a first axis, and includes a first inclined surface and a second inclined surface that are symmetrically arranged along the first axis;

[0006] A plurality of first magnetic induction pairs for sensing the magnetic field of a third axis, each of the first magnetic induction pairs includes a first magnetoresistive element and a second magnetoresistive element. The first magnetoresistive element and the second magnetoresistive element are formed by combining the same number of magnetic tunnel junctions in the same manner. The magnetic tunnel junctions of the first magnetoresistive element and the second magnetoresistive element are respectively arranged on the first inclined surface and the second inclined surface of the inclined structures on the same axis; the magnetic tunnel junctions of the first magnetoresistive element and the second magnetoresistive element have an initial magnetization direction along the first axis and the same positive and negative, and the magnetic tunnel junctions of the first magnetoresistive element and the second magnetoresistive element have a pinning direction along the inclined surface where they are located, and the components of the pinning direction in the second axis are opposite in positive and negative, and the components in the third axis are the same in positive and negative;

[0007] Wherein, the first axis, the second axis, and the third axis are perpendicular to each other in pairs, and the third axis is also perpendicular to the plane of the substrate where the inclined structure is located.

[0008] In one embodiment, the magnetic tunnel junctions of the first magnetoresistive element and the magnetic tunnel junctions of the second magnetoresistive element are annealed along a second axis in the plane of the substrate with opposite positive and negative directions; or, the magnetic tunnel junctions of the first magnetoresistive element and the magnetic tunnel junctions of the second magnetoresistive element are annealed along a third axis out of the plane of the substrate with the same positive and negative directions.

[0009] In one embodiment, the TMR magnetic sensor further includes a reset coil. The reset coil includes a plurality of coil strips extending along the second axis. The reset coil is configured to perform an operation of resetting the initial magnetization direction of the free layer of each magnetic tunnel junction when energized. The reset currents in the coil strips corresponding to the magnetic tunnel junctions of the first magnetoresistive element and the second magnetoresistive element are all along the second axis and have the same positive and negative directions.

[0010] In one embodiment, a plurality of the first magnetic induction pairs form a bridge. The bridge includes a first arm, a second arm, a third arm, and a fourth arm. One end of the first arm is connected to a voltage input terminal, and the other end is connected to a first signal output terminal; one end of the second arm is connected to the first signal output terminal, and the other end is connected to a ground terminal; one end of the third arm is connected to the ground terminal, and the other end is connected to a second signal output terminal; one end of the fourth arm is connected to the second signal output terminal, and the other end is connected to the voltage input terminal;

[0011] The first arm, the second arm, the third arm, and the fourth arm are formed by combining the same number of first magnetic induction pairs in the same manner; the initial magnetization directions of the magnetic tunnel junctions of the first magnetoresistive element and the second magnetoresistive element of the first magnetic induction pairs constituting the first arm and the fourth arm are the same, and are opposite in positive and negative on the first axis to the initial magnetization directions of the magnetic tunnel junctions of the first magnetoresistive element and the second magnetoresistive element of the first magnetic induction pairs constituting the second arm and the third arm; the resistance value changes generated by the first arm and the third arm in response to a magnetic field along the third axis are the same, and are equal in magnitude and opposite in positive and negative to the resistance value changes generated by the second arm and the fourth arm in response to a magnetic field along the third axis.

[0012] In one embodiment, the first magnetoresistive element and the second magnetoresistive element of the first magnetic induction pair are connected in series or in parallel.

[0013] In one embodiment, the number of the first magnetic induction pairs in the first arm, the second arm, the third arm, and the fourth arm is two or more, and they are combined in the same series and / or parallel manner.

[0014] In one embodiment, the TMR magnetic sensor further includes a plurality of second magnetic induction pairs for sensing the magnetic field of the third axis. Each of the second magnetic induction pairs includes a third magnetoresistive element and a fourth magnetoresistive element. The number and combination mode of the magnetic tunnel junctions of the third magnetoresistive element and the fourth magnetoresistive element are the same as those of the magnetic tunnel junctions of the first magnetoresistive element and the second magnetoresistive element. The magnetic tunnel junctions of the third magnetoresistive element and the fourth magnetoresistive element are respectively disposed on the first inclined surface and the second inclined surface of another inclined structure on the same axis. The pinning direction of the magnetic tunnel junction of the third magnetoresistive element is the same as the pinning direction of the magnetic tunnel junction of the first magnetoresistive element, and the pinning direction of the magnetic tunnel junction of the fourth magnetoresistive element is the same as the pinning direction of the magnetic tunnel junction of the second magnetoresistive element;

[0015] The initial magnetization directions of the magnetic tunnel junctions of the third magnetoresistive element and the fourth magnetoresistive element are the same as those of the magnetic tunnel junctions of the first magnetoresistive element and the second magnetoresistive element; the first magnetoresistive element and the fourth magnetoresistive element correspond to the same coil strip, and the second magnetoresistive element and the third magnetoresistive element correspond to another same coil strip.

[0016] In one embodiment, a plurality of the first magnetic induction pairs and a plurality of the second magnetic induction pairs form a bridge. The bridge includes a first bridge arm, a second bridge arm, a third bridge arm, and a fourth bridge arm. One end of the first bridge arm is connected to the voltage input terminal, and the other end is connected to the first signal output terminal. One end of the second bridge arm is connected to the first signal output terminal, and the other end is connected to the ground terminal; one end of the third bridge arm is connected to the ground terminal, and the other end is connected to the second signal output terminal; one end of the fourth bridge arm is connected to the second signal output terminal, and the other end is connected to the voltage input terminal;

[0017] The first bridge arm, the second bridge arm, the third bridge arm, and the fourth bridge arm are formed by the same number of first magnetic induction pairs and second magnetic induction pairs and are combined in the same way; the initial magnetization directions of the magnetic tunnel junctions of the first magnetoresistive element, the second magnetoresistive element of the first magnetic induction pair and the third magnetoresistive element, the fourth magnetoresistive element of the second magnetic induction pair that constitute the first bridge arm and the fourth bridge arm are the same, and are opposite in sign on the first axis to the initial magnetization directions of the magnetic tunnel junctions of the first magnetoresistive element, the second magnetoresistive element of the first magnetic induction pair and the third magnetoresistive element, the fourth magnetoresistive element of the second magnetic induction pair that constitute the second bridge arm and the third bridge arm;

[0018] The resistance value changes generated by the first bridge arm and the third bridge arm in sensing the magnetic field of the third axis are the same, and are equal in magnitude and opposite in sign to the resistance value changes generated by the second bridge arm and the fourth bridge arm in sensing the magnetic field of the third axis.

[0019] In one embodiment, the third magnetoresistive element and the fourth magnetoresistive element corresponding to the second magnetic induction are connected in series or in parallel.

[0020] In one embodiment, among the first bridge arm, the second bridge arm, the third bridge arm, and the fourth bridge arm, the number of the first magnetic induction pairs and the second magnetic induction pairs is respectively one, two, or more than two, and they are combined in the same series and / or parallel manner.

[0021] For the above TMR magnetic sensor, the two magnetoresistive elements constituting the magnetic induction pair are respectively arranged on two opposite inclined planes of the inclined structure on the same axis. By defining the initial magnetization direction and the pinning direction, the induction of the two magnetoresistive elements to the in-plane magnetic field can be cancelled out, thereby reducing the cross-axis interference and improving the anti-interference ability of the out-of-plane magnetic field detection. Description of the Drawings

[0022] Figure 1 It is a schematic structural diagram of a TMR magnetic sensor in one embodiment;

[0023] Figure 2 It is a schematic arrangement diagram of the ramp structure and the magnetic tunnel junction on a wafer in one embodiment;

[0024] Figure 3 It is a schematic diagram of the distribution and circuit connection of the first magnetic induction pair in one embodiment;

[0025] Figure 4 It is an equivalent circuit diagram of the bridge composed of the first magnetic induction pair in one embodiment;

[0026] Figure 5 It is an equivalent circuit diagram of the bridge composed of the first magnetic induction pair in another embodiment;

[0027] Figure 6 It is a schematic diagram of the distribution and circuit connection of the first magnetic induction pair in yet another embodiment;

[0028] Figure 7 It is an equivalent circuit diagram of the bridge composed of the first magnetic induction pair in yet another embodiment;

[0029] Figure 8 It is a schematic structural diagram of a TMR magnetic sensor in another embodiment;

[0030] Figure 9 It is a schematic diagram of the distribution and circuit connection of the first magnetic induction pair and the second magnetic induction pair in one embodiment;

[0031] Figure 10 It is an equivalent circuit diagram of the bridge composed of the first magnetic induction pair and the second magnetic induction pair in one embodiment;

[0032] Figure 11The equivalent circuit diagram of the bridge arm of the bridge in one embodiment;

[0033] Figure 12 The equivalent circuit diagram of the bridge arm of the bridge in another embodiment. Detailed implementation manners

[0034] In order to make the objectives, technical solutions and advantages of the present application more clear and understandable, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs. The terms used in the description of this application herein are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0036] It can be understood that in the following embodiments, "connection", if there is a transmission of electrical signals or data between the connected circuits, modules, units, etc., should be understood as "electrical connection", "communication connection", etc.

[0037] As used herein, the singular forms "a", "an" and "the" may also include the plural forms unless the context clearly dictates otherwise. It should also be understood that the terms "comprises / comprising" or "has / including" etc. specify the presence of the stated features, wholes, methods, operations, components, parts or combinations thereof, but do not preclude the presence or addition of one or more other features, wholes, methods, operations, components, parts or combinations thereof.

[0038] In one embodiment, as Figure 1As shown, a TMR magnetic sensor is provided, which includes a plurality of inclined structures 110 and a plurality of first magnetic induction pairs 120 for sensing the magnetic field of the third axis. Each inclined structure 110 is arranged along the first axis and includes a first inclined surface X1 and a second inclined surface X2 that are symmetrically arranged along the first axis. Each first magnetic induction pair 120 includes a first magnetoresistive element and a second magnetoresistive element. The first magnetoresistive element and the second magnetoresistive element are formed by combining the same number of magnetic tunnel junctions 130 in the same manner. The magnetic tunnel junctions 130 of the first magnetoresistive element and the second magnetoresistive element are respectively arranged on the first inclined surface X1 and the second inclined surface X2 of the inclined structure 110 on the same axis. The magnetic tunnel junctions 130 of the first magnetoresistive element and the second magnetoresistive element have an initial magnetization direction along the first axis and the same positive and negative. The magnetic tunnel junctions 130 of the first magnetoresistive element and the second magnetoresistive element have a pinning direction along the inclined surface where they are located, and the components of the pinning direction in the second axis are opposite in positive and negative, and the components in the third axis are the same in positive and negative. In addition, the TMR magnetic sensor further includes a substrate, and the inclined structure 110 is arranged on the substrate. The first axis, the second axis, and the third axis are perpendicular to each other in pairs, and the third axis is also perpendicular to the plane of the substrate where the inclined structure 110 is located.

[0039] Among them, the inclined structure 110 can be a boss or a groove structure. The number of magnetic tunnel junctions 130 in the first magnetoresistive element and the second magnetoresistive element can be one, two, or more. The magnetic tunnel junctions 130 in the first magnetoresistive element and the second magnetoresistive element are combined in the same manner, which means that the magnetic tunnel junctions 130 in the first magnetoresistive element and the second magnetoresistive element are combined in the same series and / or parallel manner. The inclined structures 110 on the same axis can be the same inclined structure 110, or two inclined structures 110 located in the same row (such as Figure 2As shown. That is, the magnetic tunnel junctions 130 of the first magnetoresistive element and the second magnetoresistive element are respectively disposed on the first inclined surface X1 and the second inclined surface X2 of the same inclined structure 110; alternatively, two inclined structures 110 in the same row have the same axis, and the magnetic tunnel junctions 130 of the first magnetoresistive element and the second magnetoresistive element are respectively disposed on the first inclined surface X1 of one of the inclined structures 110 and the second inclined surface X2 of the other inclined structure 110. The magnetic tunnel junctions 130 of the first magnetoresistive element and the second magnetoresistive element have an initial magnetization direction along the first axis and the same positive and negative signs, which means that the initial magnetization directions of the magnetic tunnel junctions 130 of the first magnetoresistive element and the second magnetoresistive element both point in the positive direction of the first axis, or both point in the negative direction of the first axis. The components of the pinning directions of the magnetic tunnel junctions 130 of the first magnetoresistive element and the second magnetoresistive element in the second axis have opposite positive and negative signs, which means that the component of the pinning direction of the magnetic tunnel junction 130 of one of the first magnetoresistive element and the second magnetoresistive element in the second axis points in the positive direction of the second axis, and the component of the pinning direction of the magnetic tunnel junction 130 of the other of the first magnetoresistive element and the second magnetoresistive element in the second axis points in the negative direction of the second axis. The components of the pinning directions of the magnetic tunnel junctions 130 of the first magnetoresistive element and the second magnetoresistive element in the third axis have the same positive and negative signs, which means that the components of the pinning directions of the magnetic tunnel junctions 130 of the first magnetoresistive element and the second magnetoresistive element in the third axis both point in the positive direction of the third axis, or both point in the negative direction of the third axis. In addition, the initial magnetization direction corresponds to the magnetic easy axis direction of the first magnetoresistive element and the second magnetoresistive element in the plane, and the component of the pinning direction in the second axis corresponds to the magnetic hard axis direction of the first magnetoresistive element and the second magnetoresistive element in the plane. The first axis and the second axis can be the X axis and the Y axis respectively, or can be the Y axis and the X axis respectively, the third axis is the Z axis, and the plane of the substrate where the inclined structure 110 is located is the X-Y plane.

[0040] For ease of understanding, hereinafter, it is described by taking the inclined structure 110 as a groove structure, the number of magnetic tunnel junctions 130 in the first magnetoresistive element and the second magnetoresistive element being two and combined in series, and the first axis, the second axis and the third axis being the X axis, the Y axis and the Z axis respectively as an example.

[0041] The magnetic tunnel junction 130 generally includes a free layer / a tunnel barrier layer / a pinned layer. The change of the external magnetic field will cause the magnetization direction of the free layer to change. When the magnetization direction of the free layer is parallel to the pinning direction of the pinned layer in the positive direction, the magnetic tunnel junction 130 is in a low resistance state; when the magnetization direction of the free layer is parallel to the pinning direction of the pinned layer in the reverse direction, the magnetic tunnel junction 130 is in a high resistance state. Thus, it can be seen that the magnetic field component parallel to the pinning direction of the external magnetic field can cause the change of the magnetization direction of the free layer, and based on the parallel state with the pinning direction of the pinned layer, it can cause the resistance value change of the magnetic tunnel junction 130. The magnetoresistive element formed by combining the magnetic tunnel junctions 130 in series, in parallel or in a combination of series and parallel can sense the external magnetic field.

[0042] Please continue to refer to Figure 1 In this embodiment, the first magnetoresistive element R11 and the second magnetoresistive element R11' form a first magnetic induction pair 120, and the first magnetoresistive element R12' and the second magnetoresistive element R12 form another first magnetic induction pair 120. The magnetic tunnel junctions 130 of the first magnetoresistive element R11 and the second magnetoresistive element R11' are respectively disposed on the first inclined surface X1 and the second inclined surface X2 of the same inclined structure 110. The magnetic tunnel junctions 130 of the first magnetoresistive element R12' and the second magnetoresistive element R12 are also respectively disposed on the first inclined surface X1 and the second inclined surface X2 of the same inclined structure 110. The magnetic tunnel junctions 130 of the first magnetoresistive element R11, the first magnetoresistive element R12', the second magnetoresistive element R11', and the second magnetoresistive element R12 have an initial magnetization direction along the negative X-axis direction. The magnetic tunnel junctions 130 of the first magnetoresistive element R11, the second magnetoresistive element R11', the first magnetoresistive element R12', and the second magnetoresistive element R12 have a pinning direction along the inclined surface where they are located, and the components of the pinning direction of the magnetic tunnel junction 130 of the first magnetoresistive element R11 in the Y-axis and Z-axis directions are +y and +z respectively, the components of the pinning direction of the magnetic tunnel junction 130 of the second magnetoresistive element R11' in the Y-axis and Z-axis directions are -y and +z respectively, the components of the pinning direction of the magnetic tunnel junction 130 of the first magnetoresistive element R12' in the Y-axis and Z-axis directions are -y and -z respectively, and the components of the pinning direction of the magnetic tunnel junction 130 of the second magnetoresistive element R12 in the Y-axis and Z-axis directions are +y and -z respectively. It can be understood that since the inclined structures 110 are arranged along the X-axis and the first inclined surface X1 and the second inclined surface X2 of each inclined structure 110 are symmetrically arranged along the X-axis, the first inclined surface X1 and the second inclined surface X2 are inclined between the Y-axis and the Z-axis. Based on this, the pinning direction of the magnetic tunnel junction 130 of each magnetoresistive element has no component in the X-axis direction and only has components in the Y-axis and Z-axis directions.

[0043] Taking the first magnetic induction pair 120 formed by the first magnetoresistive element R11 and the second magnetoresistive element R11' as an example, when sensing an external magnetic field, R11 ∝ Hz * S, R11 ∝ Hy * C1; R11' ∝ Hz * S, R11' ∝ -Hy * C2, where S represents the out-of-plane magnetic field induction coefficient, C1 and C2 represent the in-plane magnetic field induction coefficients, Hy and Hz respectively represent the Y-axis component and Z-axis component of the external magnetic field, and the magnitudes of C1 and C2 are related to the slope of the inclined structure 110. It can be seen that when C1 and C2 are not equal, the first magnetic induction pair 120 formed by the first magnetoresistive element R11 and the second magnetoresistive element R11' senses the Z-axis component of the external magnetic field and also senses the Y-axis component of the external magnetic field while sensing the Z-axis component of the external magnetic field, that is, when the first magnetic induction pair 120 senses the Z-axis component of the external magnetic field, the Y-axis component of the external magnetic field generates a cross-axis interference on the induction of the first magnetic induction pair 120.

[0044] Each inclined structure 110 is arranged along the first axis, and the first inclined surface X1 and the second inclined surface X2 of each inclined structure 110 are symmetrically arranged along the first axis. When the manufacturing process is the same, the ramp slopes of the first inclined surface X1 and the second inclined surface X2 of each inclined structure 110, and the ramp slopes of each inclined structure 110 should be the same. However, in the actual manufacturing process, since the inclined structures 110 are arranged along the X-axis direction, the process errors between the inclined structures 110 in the Y-axis direction will be relatively large. The greater the process error between the inclined structures 110, the greater the gap between C1 and C2, resulting in a greater cross-axis interference on the induction of the first magnetic induction pair 120 by the Y-axis component of the external magnetic field. As Figure 2 shown, multiple inclined structures 110 can be fabricated on the wafer along the X-axis. The distance between the magnetoresistive elements on the first inclined surface X1 and the second inclined surface X2 of the inclined structures 110 located on the same axis in the Y-axis direction is d1, and the distance between the magnetoresistive elements on the first inclined surface X1 and the second inclined surface X2 of the inclined structures 110 located on different axes in the Y-axis direction is d2, where d1 < d2. In this embodiment, by arranging the magnetic tunnel junctions 130 of the first magnetoresistive element and the second magnetoresistive element on the first inclined surface X1 and the second inclined surface X2 of the inclined structures 110 on the same axis respectively, the distance between the first magnetoresistive element and the second magnetoresistive element in the Y-axis direction can be minimized, that is, the first inclined surface X1 and the second inclined surface X2 with relatively small process errors are selected. In this way, the ramp slopes of the first inclined surface X1 and the second inclined surface X2 are relatively close, making C1 and C2 relatively close as well. When the first magnetoresistive element and the second magnetoresistive element form the first magnetic induction pair 120, the inductions of the Y-axis component of the external magnetic field can be basically cancelled out, thereby reducing the cross-axis interference and the Z-axis noise.

[0045] The pinning direction of the magnetic tunnel junction 130 can be determined by the annealing magnetic field. The magnetic tunnel junctions 130 of the first magnetoresistive element and the second magnetoresistive element can be annealed along the second axis in the plane of the substrate with opposite positive and negative directions. Based on this in-plane annealing method, the first inclined surface X1 and the second inclined surface X2 are symmetrically arranged along the first axis, and the magnetic tunnel junctions 130 of the first magnetoresistive element and the second magnetoresistive element are located on the first inclined surface X1 and the second inclined surface X2 respectively, such that the components of the pinning directions of the magnetic tunnel junctions 130 of the first magnetoresistive element and the second magnetoresistive element in the second axis are opposite in sign and the components in the third axis are the same in sign. In this embodiment, as Figure 1As shown, the solid arrows represent the in-plane annealing directions. The magnetic tunnel junction 130 of the first magnetoresistive element is annealed in the positive Y-axis direction, and the magnetic tunnel junction 130 of the second magnetoresistive element is annealed in the negative Y-axis direction, such that the components of the pinning direction of the magnetic tunnel junction 130 of the first magnetoresistive element R11 along the Y-axis and Z-axis are +y and +z respectively, the components of the pinning direction of the magnetic tunnel junction 130 of the second magnetoresistive element R11' along the Y-axis and Z-axis are -y and +z respectively, the components of the pinning direction of the magnetic tunnel junction 130 of the first magnetoresistive element R12' along the Y-axis and Z-axis are -y and -z respectively, and the components of the pinning direction of the magnetic tunnel junction 130 of the second magnetoresistive element R12 along the Y-axis and Z-axis are +y and -z respectively. Alternatively, the magnetic tunnel junction 130 of the first magnetoresistive element and the magnetic tunnel junction 130 of the second magnetoresistive element can be annealed out-of-plane along the third axis of the substrate, and the positive and negative directions are the same. Similarly, based on this out-of-plane annealing method, the first inclined plane X1 and the second inclined plane X2 are symmetrically arranged along the first axis, and the magnetic tunnel junctions 130 of the first magnetoresistive element and the second magnetoresistive element are respectively located on the first inclined plane X1 and the second inclined plane X2, such that the components of the pinning directions of the magnetic tunnel junctions 130 of the first magnetoresistive element and the second magnetoresistive element along the second axis are opposite in sign, and the components along the third axis are the same in sign.

[0046] Furthermore, the TMR magnetic sensor further includes a reset coil 140. The reset coil 140 includes a plurality of coil strips extending along the second axis. The reset coil 140 is used to perform an initial magnetization direction reset operation on each magnetic tunnel junction 130 when energized. The reset currents in the coil strips corresponding to the magnetic tunnel junctions 130 of the first magnetoresistive element and the second magnetoresistive element are all along the second axis, and the positive and negative directions are the same. Specifically, after being energized, the coil strips of the reset coil 140 can transmit current in the positive direction along the second axis or in the negative direction along the second axis. In this embodiment, as Figure 1 shown, the dashed arrows represent the reset current directions. The coil strips of the reset coil 140 transmit current in the positive Y-axis direction after being energized, such that the magnetic tunnel junctions 130 of the first magnetoresistive element and the second magnetoresistive element have an initial magnetization direction along the negative X-axis direction. In addition, the magnetic tunnel junctions 130 of the first magnetoresistive element and the second magnetoresistive element are both arranged along the first axis. When the width of a coil strip in the first axis direction is not sufficient to cover the magnetic tunnel junctions 130 of the first magnetoresistive element and the second magnetoresistive element simultaneously, different magnetoresistive elements will correspond to different coil strips. For example, the first magnetoresistive element corresponds to the first coil strip, and the second magnetoresistive element corresponds to the second coil strip.

[0047] In one embodiment, in order to smoothly output the analog signals generated by multiple first magnetic sensors 120 in response to the third-axis magnetic field, multiple first magnetic sensors 120 can form a bridge circuit. The bridge circuit includes a first arm, a second arm, a third arm, and a fourth arm. One end of the first arm is connected to the voltage input terminal, and the other end is connected to the first signal output terminal. One end of the second arm is connected to the first signal output terminal, and the other end is connected to the ground terminal. One end of the third arm is connected to the ground terminal, and the other end is connected to the second signal output terminal. One end of the fourth arm is connected to the second signal output terminal, and the other end is connected to the voltage input terminal. The first arm to the fourth arm are formed by combining the same number of first magnetic sensors 120 in the same manner. The initial magnetization directions of the magnetic tunnel junctions 130 of the first magnetic resistance elements and the second magnetic resistance elements of the first magnetic sensors 120 that make up the first arm and the fourth arm are the same, and are opposite in sign on the first axis to the initial magnetization directions of the magnetic tunnel junctions 130 of the first magnetic resistance elements and the second magnetic resistance elements of the first magnetic sensors 120 that make up the second arm and the third arm. In addition, the resistance changes generated by the first arm and the third arm in response to the third-axis magnetic field are the same, and are equal in magnitude and opposite in sign to the resistance changes generated by the second arm and the fourth arm in response to the third-axis magnetic field.

[0048] Among them, the first magnetic resistance element and the second magnetic resistance element of the first magnetic sensor 120 can be connected in series or in parallel.

[0049] The number of first magnetic sensors 120 in the first arm to the fourth arm can be one, two, or more. When the number of first magnetic sensors 120 is two or more, the first magnetic sensors 120 in the first arm to the fourth arm are combined in the same series and / or parallel manner.

[0050] Such as Figure 3 and Figure 4As shown, in one of the embodiments, the first to fourth bridge arms are each formed by a first magnetic induction pair 120, and the first magnetoresistive element and the second magnetoresistive element of the first magnetic induction pair 120 are connected in series. Specifically, the first magnetoresistive element R11 and the second magnetoresistive element R11' are connected in series to form a first magnetic induction pair 120 and serve as the first bridge arm, the first magnetoresistive element R12' and the second magnetoresistive element R12 are connected in series to form a first magnetic induction pair 120 and serve as the fourth bridge arm, the first magnetoresistive element R13 and the second magnetoresistive element R13' are connected in series to form a first magnetic induction pair 120 and serve as the second bridge arm, and the first magnetoresistive element R14' and the second magnetoresistive element R14 are connected in series to form a first magnetic induction pair 120 and serve as the third bridge arm. The coil bars corresponding to the first magnetoresistive element R11, the first magnetoresistive element R12', and the second magnetoresistive element R11', the second magnetoresistive element R12 conduct a reset current in one of the positive direction or the negative direction of the second axis, and the coil bars corresponding to the first magnetoresistive element R13, the first magnetoresistive element R14', and the second magnetoresistive element R13', the second magnetoresistive element R14 conduct a reset current in the other of the positive direction or the negative direction of the second axis. The magnetic tunnel junctions 130 of the first magnetoresistive element R11, the first magnetoresistive element R14', and the second magnetoresistive element R12, the second magnetoresistive element R13' are annealed in one of the positive direction or the negative direction of the second axis, and the magnetic tunnel junctions 130 of the first magnetoresistive element R12', the first magnetoresistive element R13, and the second magnetoresistive element R11', the second magnetoresistive element R14 are annealed in the other of the positive direction or the negative direction of the second axis.

[0051] Further, in order to facilitate annealing of the magnetic tunnel junctions 130 of the first magnetoresistive element and the second magnetoresistive element to set the pinning direction, so that the resistance value changes generated by each bridge arm in response to the third-axis magnetic field meet the requirements, and to facilitate resetting by the reset current to set the initial magnetization direction. In the second-axis direction, the first magnetoresistive element R11 and the second magnetoresistive element R12 are disposed opposite to each other and correspond to the same coil bar, the first magnetoresistive element R12' and the second magnetoresistive element R11' are disposed opposite to each other and correspond to the same coil bar, the first magnetoresistive element R13 and the second magnetoresistive element R14 are disposed opposite to each other and correspond to the same coil bar, and the first magnetoresistive element R14' and the second magnetoresistive element R13' are disposed opposite to each other and correspond to the same coil bar.

[0052] Please continue to refer to Figure 3 and Figure 4, in this embodiment, the first magnetoresistive element R11 and the second magnetoresistive element R11' form the first bridge arm, the first magnetoresistive element R12' and the second magnetoresistive element R12 form the fourth bridge arm, the first magnetoresistive element R13 and the second magnetoresistive element R13' form the second bridge arm, and the first magnetoresistive element R14' and the second magnetoresistive element R14 form the third bridge arm; the first bridge arm is connected to the voltage input terminal VCC and the first signal output terminal Vn1, the second bridge arm is connected to the ground terminal GND and the first signal output terminal Vn1, the third bridge arm is connected to the ground terminal GND and the second signal output terminal Vp1, and the fourth bridge arm is connected to the voltage input terminal VCC and the second signal output terminal Vp1. The coil bars corresponding to the first magnetoresistive element R11, the first magnetoresistive element R12', the second magnetoresistive element R11', and the second magnetoresistive element R12 conduct a reset current in the positive Y-axis direction, and the coil bars corresponding to the first magnetoresistive element R13, the first magnetoresistive element R14', the second magnetoresistive element R13', and the second magnetoresistive element R14 conduct a reset current in the negative Y-axis direction (the direction of the reset current is as shown by the dashed arrow in Figure 3 ). In this way, the initial magnetization directions of the magnetic tunnel junctions 130 of the first magnetoresistive element R11, the first magnetoresistive element R12', the second magnetoresistive element R11', and the second magnetoresistive element R12 are along the negative X-axis direction, and the initial magnetization directions of the magnetic tunnel junctions 130 of the first magnetoresistive element R13, the first magnetoresistive element R14', the second magnetoresistive element R13', and the second magnetoresistive element R14 are along the positive X-axis direction (the initial magnetization directions are as shown by the solid arrow in Figure 4 ). Anneal the magnetic tunnel junctions 130 of the first magnetoresistive element R11, the first magnetoresistive element R14', the second magnetoresistive element R12, and the second magnetoresistive element R13' in the positive Y-axis direction, and anneal the magnetic tunnel junctions 130 of the first magnetoresistive element R12', the first magnetoresistive element R13, the second magnetoresistive element R11', and the second magnetoresistive element R14 in the negative Y-axis direction. In this way, the magnetic tunnel junctions 130 of the first magnetoresistive element R11 and the first magnetoresistive element R14' have a pinning direction that is directly upward along the first inclined plane X1 of the inclined structure 110, and the components in the Y-axis and Z-axis directions are +y and +z respectively. The magnetic tunnel junctions 130 of the second magnetoresistive element R11' and the second magnetoresistive element R14 have a pinning direction that is directly downward along the second inclined plane X2 of the inclined structure 110, and the components in the Y-axis and Z-axis directions are -y and +z respectively. The magnetic tunnel junctions 130 of the first magnetoresistive element R12' and the first magnetoresistive element R13 have a pinning direction that is directly downward along the first inclined plane X1 of the inclined structure 110, and the components in the Y-axis and Z-axis directions are -y and -z respectively. The magnetic tunnel junctions 130 of the second magnetoresistive element R12 and the second magnetoresistive element R13' have a pinning direction that is directly upward along the second inclined plane X2 of the inclined structure 110, and the components in the Y-axis and Z-axis directions are +y and -z respectively (the hollow arrow in Figure 4 represents the component of the pinning direction of the magnetic tunnel junction 130 in the Y-axis). The differential signal of the bridge is as follows:

[0053]

[0054] Among them, the differential signals of the bridge include Sz and Sy. Sz has an approximately linear variation relationship with the Z-axis component of the external magnetic field. That is, the Z-axis component of the external magnetic field can be detected through Sz; MR and Hk represent the inherent properties of the magnetic tunnel junction, which are magnetoresistivity and anisotropy field respectively; Hy and Hz represent the Y-axis component and Z-axis component of the external magnetic field respectively; S represents the out-of-plane magnetic field induction coefficient; C1 and C2 represent the in-plane induction coefficients.

[0055] Since the inclined surface of the inclined structure 110 is inclined between the Y-axis and the Z-axis, the Y-axis component of the external magnetic field will cause cross-axis interference to the detection of the Z-axis component. In order to avoid cross-axis interference, the smaller Sy generated by the Y-axis component of the external magnetic field is better. The magnitudes of C1 and C2 are related to the slope of the inclined surface of the inclined structure 110. In the direction of the hard magnetic axis, the smaller the distance between the magnetoresistive elements forming the magnetic induction pair, the smaller the process error, and the closer C1 and C2 are, so that the smaller Sy is, reducing cross-axis interference. It can be understood that if the inclined surface of the inclined structure 110 is inclined between the X-axis and the Z-axis, the X-axis component of the external magnetic field will cause cross-axis interference to the detection of the Z-axis component. In order to avoid cross-axis interference, it is better to make Sx generated by the X-axis component of the external magnetic field as small as possible.

[0056] As Figure 5 shown, in another embodiment, the first to fourth bridge arms are all formed by a first magnetic induction pair 120, and the first magnetic resistance element and the second magnetic resistance element of the first magnetic induction pair 120 are in parallel. Specifically, the first magnetic resistance element R11 and the second magnetic resistance element R11' are in parallel to form a first magnetic induction pair 120 and serve as the first bridge arm, the first magnetic resistance element R12' and the second magnetic resistance element R12 are in parallel to form a first magnetic induction pair 120 and serve as the fourth bridge arm, the first magnetic resistance element R13 and the second magnetic resistance element R13' are in parallel to form a first magnetic induction pair 120 and serve as the second bridge arm, and the first magnetic resistance element R14' and the second magnetic resistance element R14 are in parallel to form a first magnetic induction pair 120 and serve as the third bridge arm. The first bridge arm is connected to the voltage input terminal VCC and the first signal output terminal Vn2, the second bridge arm is connected to the ground terminal GND and the first signal output terminal Vn2, the third bridge arm is connected to the ground terminal GND and the second signal output terminal Vp2, and the fourth bridge arm is connected to the voltage input terminal VCC and the second signal output terminal Vp2.

[0057] As Figure 6 and Figure 7As shown, in yet another embodiment, the first to fourth bridge arms are each formed by connecting two first magnetic induction pairs 120 in series, and the first magnetoresistive element and the second magnetoresistive element of each first magnetic induction pair 120 are connected in series. Specifically, there are two first magnetoresistive elements R11 and two second magnetoresistive elements R11'. After being connected in series to form two first magnetic induction pairs 120, they are then connected in series to form the first bridge arm. There are two first magnetoresistive elements R12' and two second magnetoresistive elements R12. After being connected in series to form two first magnetic induction pairs 120, they are then connected in series to form the fourth bridge arm. There are two first magnetoresistive elements R13 and two second magnetoresistive elements R13'. After being connected in series to form two first magnetic induction pairs 120, they are then connected in series to form the second bridge arm. And there are two first magnetoresistive elements R14' and two second magnetoresistive elements R14. After being connected in series to form two first magnetic induction pairs 120, they are then connected in series to form the third bridge arm. The first bridge arm is connected to the voltage input terminal VCC and the first signal output terminal Vn3. The second bridge arm is connected to the ground terminal GND and the first signal output terminal Vn3. The third bridge arm is connected to the ground terminal GND and the second signal output terminal Vp3. The fourth bridge arm is connected to the voltage input terminal VCC and the second signal output terminal Vp3.

[0058] It can be understood that in other embodiments, the two first magnetic induction pairs 120 in each bridge arm can also be connected in parallel. In addition, each bridge arm can also include more first magnetic induction pairs 120, and the multiple first magnetic induction pairs 120 in each bridge arm are connected in series and / or in parallel.

[0059] As mentioned above, considering that in the second axis direction, the process error of the inclined structure 110 is relatively large. Therefore, by minimizing the distance d between the first magnetoresistive element and the second magnetoresistive element that make up the first magnetic induction pair 120 as much as possible, the process error of the inclined structure 110 can be reduced, so that the formed first magnetic induction pair 120 can reduce the cross-axis interference.

[0060] Based on the above, the magnetic tunnel junctions 130 of the first magnetoresistive element (such as R11) and the second magnetoresistive element (such as R11') are distributed along the first axis direction, while the coil strips of the reset coil 140 all extend along the second axis direction. The width of the coil strip in the first axis direction is not sufficient to cover the magnetic tunnel junctions 130 of the first magnetoresistive element and the second magnetoresistive element at the same time. That is, the first magnetoresistive element corresponds to the first coil strip, and the second magnetoresistive element corresponds to the second coil strip. When there are process errors in different coil strips, there are certain differences in the generated reset magnetic fields, resulting in certain differences in the initial magnetization directions of the free layers of the magnetic tunnel junctions 130. Therefore, in order to compensate for the differences caused by the coil process errors, a second magnetic induction pair can also be provided.

[0061] In one embodiment, as Figure 8As shown, the TMR magnetic sensor further includes a plurality of second magnetic induction pairs 150 for sensing the magnetic field of the third axis. Each second magnetic induction pair 150 includes a third magnetoresistive element and a fourth magnetoresistive element, such as the third magnetoresistive element R21 and the fourth magnetoresistive element R21'. The number and combination mode of the magnetic tunnel junctions 130 of the third magnetoresistive element and the fourth magnetoresistive element are the same as those of the magnetic tunnel junctions 130 of the first magnetoresistive element and the second magnetoresistive element. The magnetic tunnel junctions 130 of the third magnetoresistive element and the fourth magnetoresistive element are respectively disposed on the first inclined surface X1 and the second inclined surface X2 of another inclined structure 110 on the same axis. The pinning direction of the magnetic tunnel junction 130 of the third magnetoresistive element is the same as that of the magnetic tunnel junction 130 of the first magnetoresistive element, and the pinning direction of the magnetic tunnel junction 130 of the fourth magnetoresistive element is the same as that of the magnetic tunnel junction 130 of the second magnetoresistive element. The initial magnetization directions of the magnetic tunnel junctions 130 of the third magnetoresistive element and the fourth magnetoresistive element are the same as those of the magnetic tunnel junctions 130 of the first magnetoresistive element and the second magnetoresistive element. The first magnetoresistive element and the fourth magnetoresistive element correspond to the same coil strip, and the second magnetoresistive element and the third magnetoresistive element correspond to another same coil strip.

[0062] Specifically, as Figure 8 shown, the third magnetoresistive element R21 and the fourth magnetoresistive element R21' form a second magnetic induction pair 150. The magnetic tunnel junctions 130 of the third magnetoresistive element R21 and the fourth magnetoresistive element R21' are respectively disposed on the first inclined surface X1 and the second inclined surface X2 of the same inclined structure 110. The magnetic tunnel junctions 130 of the third magnetoresistive element R21 and the fourth magnetoresistive element R21' have a pinning direction along the inclined surface where they are located. The components of the pinning direction of the magnetic tunnel junction 130 of the third magnetoresistive element R21 on the Y-axis and the Z-axis are +y and +z respectively, and the components of the pinning direction of the magnetic tunnel junction 130 of the fourth magnetoresistive element R21' on the Y-axis and the Z-axis are -y and +z respectively. The magnetic tunnel junctions 130 of the third magnetoresistive element R21 and the fourth magnetoresistive element R21' have an initial magnetization direction along the negative X-axis direction. The first magnetoresistive element R11 and the fourth magnetoresistive element R21' correspond to the first coil strip, and the second magnetoresistive element R11' and the third magnetoresistive element R21 correspond to the second coil strip.

[0063] The initial magnetization directions of the free layers of the magnetic tunnel junctions 130 of the third magnetoresistive element and the fourth magnetoresistive element are the same as those of the free layers of the magnetic tunnel junctions 130 of the first magnetoresistive element and the second magnetoresistive element. The first coil strip and the second coil strip have the same current transmission direction. In this embodiment, the first coil strip and the second coil strip have a reset current along the positive Y-axis direction. Additionally, the magnetic tunnel junctions 130 of the first magnetoresistive element and the fourth magnetoresistive element are covered by the first coil strip (the coil strip can be above or below the magnetic tunnel junction 130, as long as its projection in the plane covers the magnetic tunnel junction 130), and the magnetic tunnel junctions 130 of the second magnetoresistive element and the third magnetoresistive element are covered by the second coil strip.

[0064] The annealing direction of the magnetic tunnel junction 130 of the third magnetoresistive element is the same as that of the magnetic tunnel junction 130 of the first magnetoresistive element; the annealing direction of the magnetic tunnel junction 130 of the fourth magnetoresistive element is the same as that of the magnetic tunnel junction 130 of the second magnetoresistive element. Similarly, the magnetic tunnel junctions 130 of the third magnetoresistive element and the fourth magnetoresistive element can be annealed along the second axis in the plane of the substrate with opposite positive and negative directions; or the magnetic tunnel junctions 130 of the third magnetoresistive element and the fourth magnetoresistive element can be annealed along the third axis outside the plane of the substrate with the same positive and negative directions, such that the components of the pinning directions of the magnetic tunnel junctions 130 of the third magnetoresistive element and the fourth magnetoresistive element along the second axis have opposite positive and negative values, and the components along the third axis have the same positive and negative values.

[0065] In one embodiment, in order to smoothly output the analog signals generated by multiple first magnetic induction pairs 120 and multiple second magnetic induction pairs 150 sensing the magnetic field in the third axis, multiple first magnetic induction pairs 120 and multiple second magnetic induction pairs 150 can form a bridge. The bridge includes a first arm, a second arm, a third arm, and a fourth arm. One end of the first arm is connected to the voltage input terminal, and the other end is connected to the first signal output terminal. One end of the second arm is connected to the first signal output terminal, and the other end is connected to the ground terminal; one end of the third arm is connected to the ground terminal, and the other end is connected to the second signal output terminal; one end of the fourth arm is connected to the second signal output terminal, and the other end is connected to the voltage input terminal. The first arm to the fourth arm are formed by the same number of first magnetic induction pairs 120 and second magnetic induction pairs 150, and are combined in the same way. The initial magnetization directions of the magnetic tunnel junctions 130 of the first magnetoresistive element, the second magnetoresistive element of the first magnetic induction pair 120, and the third magnetoresistive element, the fourth magnetoresistive element of the second magnetic induction pair 150 that make up the first arm and the fourth arm are the same, and are opposite in sign on the first axis to the initial magnetization directions of the magnetic tunnel junctions 130 of the first magnetoresistive element, the second magnetoresistive element of the first magnetic induction pair 120, and the third magnetoresistive element, the fourth magnetoresistive element of the second magnetic induction pair 150 that make up the second arm and the third arm. In addition, the resistance value changes generated by the first arm and the third arm sensing the magnetic field in the third axis are the same, and are equal in magnitude and opposite in sign to the resistance value changes generated by the second arm and the fourth arm sensing the magnetic field in the third axis.

[0066] Among them, the third magnetoresistive element and the fourth magnetoresistive element in the second magnetic induction pair 150 can be in series or in parallel. The number of first magnetic induction pairs 120 and second magnetic induction pairs 150 in the first arm to the fourth arm can be one, two, or more. The first magnetic induction pairs 120 and second magnetic induction pairs 150 in each arm are combined in the same series and / or parallel manner.

[0067] Such as Figure 9As shown, in one of the embodiments, the first to fourth bridge arms are each formed by a first magnetic induction pair 120 and a second magnetic induction pair 150, and the first magnetic induction pair 120 and the second magnetic induction pair 150 are connected in series. The first magnetic resistance element and the second magnetic resistance element in the first magnetic induction pair 120 are connected in series, and the third magnetic resistance element and the fourth magnetic resistance element in the second magnetic induction pair 150 are connected in series. Specifically, the first magnetic resistance element R11 and the second magnetic resistance element R11' are connected in series to form a first magnetic induction pair 120, and the third magnetic resistance element R21 and the fourth magnetic resistance element R21' are connected in series to form a second magnetic induction pair 150. The two magnetic induction pairs are then connected in series as the first bridge arm. The first magnetic resistance element R12' and the second magnetic resistance element R12 are connected in series to form a first magnetic induction pair 120, and the third magnetic resistance element R22' and the fourth magnetic resistance element R22 are connected in series to form a second magnetic induction pair 150. The two magnetic induction pairs are then connected in series as the fourth bridge arm. The first magnetic resistance element R13 and the second magnetic resistance element R13' are connected in series to form a first magnetic induction pair 120, and the third magnetic resistance element R23 and the fourth magnetic resistance element R23' are connected in series to form a second magnetic induction pair 150. The two magnetic induction pairs are then connected in series as the second bridge arm. Also, the first magnetic resistance element R14' and the second magnetic resistance element R14 are connected in series to form a first magnetic induction pair 120, and the third magnetic resistance element R24' and the fourth magnetic resistance element R24 are connected in series to form a second magnetic induction pair 150. The two magnetic induction pairs are then connected in series as the third bridge arm. The coil bars corresponding to the first magnetic resistance element R11, the first magnetic resistance element R12', the second magnetic resistance element R11', the second magnetic resistance element R12, the third magnetic resistance element R21, the third magnetic resistance element R22', and the fourth magnetic resistance element R21', the fourth magnetic resistance element R22 are passed with a reset current in one of the positive direction or the negative direction of the second axis. The coil bars corresponding to the first magnetic resistance element R13, the first magnetic resistance element R14', the second magnetic resistance element R13', the second magnetic resistance element R14, the third magnetic resistance element R23, the third magnetic resistance element R24', and the fourth magnetic resistance element R23', the fourth magnetic resistance element R24 are passed with a reset current in the other of the positive direction or the negative direction of the second axis. The magnetic tunnel junctions 130 of the first magnetic resistance element R11, the first magnetic resistance element R14', the second magnetic resistance element R12, the second magnetic resistance element R13', the third magnetic resistance element R21, the third magnetic resistance element R24', and the fourth magnetic resistance element R22, the fourth magnetic resistance element R23' are annealed in one of the positive direction or the negative direction of the second axis. The magnetic tunnel junctions 130 of the first magnetic resistance element R12', the first magnetic resistance element R13, the second magnetic resistance element R11', the second magnetic resistance element R14, the third magnetic resistance element R22', the third magnetic resistance element R23, and the fourth magnetic resistance element R21', the fourth magnetic resistance element R24 are annealed in the other of the positive direction or the negative direction of the second axis.

[0068] Further, in order to facilitate annealing of the magnetic tunnel junctions 130 of the first magnetoresistive element, the second magnetoresistive element, the third magnetoresistive element, and the fourth magnetoresistive element to set the pinning direction, so that the resistance changes generated by each bridge arm in response to the third-axis magnetic field meet the requirements, and to facilitate resetting by a reset current to set the initial magnetization direction. In the second-axis direction, the first magnetoresistive element R11 and the second magnetoresistive element R12 are disposed opposite to each other, the third magnetoresistive element R22' and the fourth magnetoresistive element R21' are disposed opposite to each other, and the first magnetoresistive element R11, the second magnetoresistive element R12, the third magnetoresistive element R22', and the fourth magnetoresistive element R21' correspond to the same coil bar. The first magnetoresistive element R12' and the second magnetoresistive element R11' are disposed opposite to each other, the third magnetoresistive element R21 and the fourth magnetoresistive element R22 are disposed opposite to each other, and the first magnetoresistive element R12', the second magnetoresistive element R11', the third magnetoresistive element R21, and the fourth magnetoresistive element R22 correspond to the same coil bar. The first magnetoresistive element R13 and the second magnetoresistive element R14 are disposed opposite to each other, the third magnetoresistive element R24' and the fourth magnetoresistive element R23' are disposed opposite to each other, and the first magnetoresistive element R13, the second magnetoresistive element R14, the third magnetoresistive element R24', and the fourth magnetoresistive element R23' correspond to the same coil bar. The first magnetoresistive element R14' and the second magnetoresistive element R13' are disposed opposite to each other, the third magnetoresistive element R23 and the fourth magnetoresistive element R24 are disposed opposite to each other, and the first magnetoresistive element R14', the second magnetoresistive element R13', the third magnetoresistive element R23, and the fourth magnetoresistive element R24 correspond to the same coil bar.

[0069] Such as Figure 9 And Figure 10As shown, in this embodiment, the first magnetoresistive element R11, the second magnetoresistive element R11', the third magnetoresistive element R21, and the fourth magnetoresistive element R21' form the first bridge arm; the first magnetoresistive element R12', the second magnetoresistive element R12, the third magnetoresistive element R22', and the fourth magnetoresistive element R22 form the fourth bridge arm; the first magnetoresistive element R13, the second magnetoresistive element R13', the third magnetoresistive element R23, and the fourth magnetoresistive element R23' form the second bridge arm; the first magnetoresistive element R14', the second magnetoresistive element R14, the third magnetoresistive element R24', and the fourth magnetoresistive element R24 form the third bridge arm. The first bridge arm is connected to the voltage input terminal VCC and the first signal output terminal Vn4; the second bridge arm is connected to the ground terminal GND and the first signal output terminal Vn4; the third bridge arm is connected to the ground terminal GND and the second signal output terminal Vp4; the fourth bridge arm is connected to the voltage input terminal VCC and the second signal output terminal Vp4. The coil bars corresponding to the first magnetoresistive element R11, the first magnetoresistive element R12', the second magnetoresistive element R11', the second magnetoresistive element R12, the third magnetoresistive element R21, the third magnetoresistive element R22', and the fourth magnetoresistive element R21', the fourth magnetoresistive element R22 conduct a reset current in the positive Y-axis direction. The coil bars corresponding to the first magnetoresistive element R13, the first magnetoresistive element R14', the second magnetoresistive element R13', the second magnetoresistive element R14, the third magnetoresistive element R23, the third magnetoresistive element R24', and the fourth magnetoresistive element R23', the fourth magnetoresistive element R24 conduct a reset current in the negative Y-axis direction (the direction of the reset current is as shown by the dashed arrow in Figure 9 . In this way, the initial magnetization directions of the magnetic tunnel junctions 130 of the first magnetoresistive element R11, the first magnetoresistive element R12', the second magnetoresistive element R11', the second magnetoresistive element R12, the third magnetoresistive element R21, the third magnetoresistive element R22', and the fourth magnetoresistive element R21', the fourth magnetoresistive element R22 are along the negative X-axis direction. The initial magnetization directions of the magnetic tunnel junctions 130 of the first magnetoresistive element R13, the first magnetoresistive element R14', the second magnetoresistive element R13', the second magnetoresistive element R14, the third magnetoresistive element R23, the third magnetoresistive element R24', and the fourth magnetoresistive element R23', the fourth magnetoresistive element R24 are along the positive X-axis direction (the initial magnetization direction is as shown in Figure 10(as indicated by the solid arrows). Anneal the magnetic tunnel junctions 130 of the first magnetoresistive element R11, the first magnetoresistive element R14', the second magnetoresistive element R12, the second magnetoresistive element R13', the third magnetoresistive element R21, the third magnetoresistive element R24', the fourth magnetoresistive element R22, and the fourth magnetoresistive element R23' in the positive Y-axis direction, and anneal the magnetic tunnel junctions 130 of the first magnetoresistive element R12', the first magnetoresistive element R13, the second magnetoresistive element R11', the second magnetoresistive element R14, the third magnetoresistive element R22', the third magnetoresistive element R23, the fourth magnetoresistive element R21', and the fourth magnetoresistive element R24 in the negative Y-axis direction. In this way, the magnetic tunnel junctions 130 of the first magnetoresistive element R11, the first magnetoresistive element R14', the third magnetoresistive element R21, and the third magnetoresistive element R24' have a pinning direction upward along the first inclined surface X1 of the inclined structure 110, and the components in the Y-axis and Z-axis directions are +y and +z respectively. The magnetic tunnel junctions 130 of the second magnetoresistive element R11', the second magnetoresistive element R14, the fourth magnetoresistive element R21', and the fourth magnetoresistive element R24 have a pinning direction downward along the second inclined surface X2 of the inclined structure 110, and the components in the Y-axis and Z-axis directions are -y and +z respectively. The magnetic tunnel junctions 130 of the first magnetoresistive element R12', the first magnetoresistive element R13, the third magnetoresistive element R22', and the third magnetoresistive element R23 have a pinning direction downward along the first inclined surface X1 of the inclined structure 110, and the components in the Y-axis and Z-axis directions are -y and -z respectively. The magnetic tunnel junctions 130 of the second magnetoresistive element R12, the second magnetoresistive element R13', the fourth magnetoresistive element R22, and the fourth magnetoresistive element R23' have a pinning direction upward along the second inclined surface X2 of the inclined structure 110, and the components in the Y-axis and Z-axis directions are +y and -z respectively ( Figure 10 (the hollow arrows indicate the components of the pinning direction of the magnetic tunnel junction 130 in the Y-axis).

[0070] It can be understood that in other embodiments, the first magnetic induction pair 120 and the second magnetic induction pair 150 can also be connected in parallel. In addition, each bridge arm can include more first magnetic induction pairs 120 and second magnetic induction pairs 150. The number of the first magnetic induction pairs 120 and the second magnetic induction pairs 150 is equal, and multiple first magnetic induction pairs 120 and second magnetic induction pairs 150 are connected in series and / or in parallel.

[0071] Furthermore, the way of connecting the first magnetic induction pair 120 and the second magnetic induction pair 150 in parallel is not unique. It can be that in each bridge arm, after the first magnetoresistive element and the second magnetoresistive element are connected in series / parallel, they are connected in parallel with the third magnetoresistive element and the fourth magnetoresistive element connected in series / parallel; or, in each bridge arm, after the first magnetoresistive element and the fourth magnetoresistive element are connected in series / parallel, they are connected in parallel with the second magnetoresistive element and the third magnetoresistive element connected in series / parallel. As Figure 11As shown, in each bridge arm, the first magnetoresistive element R11 and the second magnetoresistive element R11' are connected in series and then connected in parallel with the series-connected third magnetoresistive element R21 and fourth magnetoresistive element R21'. As Figure 12 shown, in each bridge arm, the first magnetoresistive element R11 and the fourth magnetoresistive element R21' are connected in series and then connected in parallel with the series-connected second magnetoresistive element R11' and third magnetoresistive element R21.

[0072] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered to be within the scope described in this specification.

[0073] The above-described embodiments only represent several implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the appended claims.

Claims

1. A TMR magnetic sensor, characterized in that, Comprising: A plurality of inclined structures, each of the inclined structures being arranged along a first axis and including a first inclined surface and a second inclined surface symmetrically arranged along the first axis; A plurality of first magnetic induction pairs for sensing a magnetic field along a third axis, each of the first magnetic induction pairs including a first magnetoresistive element and a second magnetoresistive element, the first magnetoresistive element and the second magnetoresistive element being formed by combining the same number of magnetic tunnel junctions in the same manner, the magnetic tunnel junctions of the first magnetoresistive element and the second magnetoresistive element being respectively disposed on the first inclined surface and the second inclined surface of the inclined structure on the same axis; the magnetic tunnel junctions of the first magnetoresistive element and the second magnetoresistive element have an initial magnetization direction along the first axis and the same sign, the magnetic tunnel junctions of the first magnetoresistive element and the second magnetoresistive element have a pinning direction along the inclined surface where they are located, and the components of the pinning direction in the second axis have opposite signs, and the components in the third axis have the same sign; Wherein, the first axis, the second axis and the third axis are perpendicular to each other in pairs, and the third axis is also perpendicular to the plane of the substrate where the inclined structure is located.

2. The TMR magnetic sensor according to claim 1, wherein The magnetic tunnel junctions of the first magnetoresistive element and the second magnetoresistive element are annealed along the second axis in the plane of the substrate and have opposite positive and negative directions; or, the magnetic tunnel junctions of the first magnetoresistive element and the second magnetoresistive element are annealed along the third axis outside the plane of the substrate and have the same positive and negative directions.

3. The TMR magnetic sensor according to claim 1, characterized in that It further includes a reset coil, the reset coil including a plurality of coil strips extending along the second axis, the reset coil being used for, when energized, performing a reset operation on the initial magnetization direction of the free layer of each magnetic tunnel junction, and the reset currents in the coil strips corresponding to the magnetic tunnel junctions of the first magnetoresistive element and the second magnetoresistive element are all along the second axis and have the same positive and negative directions.

4. The TMR magnetic sensor according to claim 1, characterized in that, A plurality of the first magnetic induction pairs form a bridge, the bridge including a first bridge arm, a second bridge arm, a third bridge arm and a fourth bridge arm, one end of the first bridge arm being connected to a voltage input terminal and the other end being connected to a first signal output terminal; one end of the second bridge arm being connected to the first signal output terminal and the other end being connected to a ground terminal; one end of the third bridge arm being connected to the ground terminal and the other end being connected to a second signal output terminal; one end of the fourth bridge arm being connected to the second signal output terminal and the other end being connected to the voltage input terminal; The first bridge arm, the second bridge arm, the third bridge arm and the fourth bridge arm are formed by combining the same number of first magnetic induction pairs in the same manner; the initial magnetization directions of the magnetic tunnel junctions of the first magnetoresistive element and the second magnetoresistive element of the first magnetic induction pairs constituting the first bridge arm and the fourth bridge arm are the same, and are opposite in sign on the first axis to the initial magnetization directions of the magnetic tunnel junctions of the first magnetoresistive element and the second magnetoresistive element of the first magnetic induction pairs constituting the second bridge arm and the third bridge arm; the resistance value changes generated by the first bridge arm and the third bridge arm in sensing the magnetic field along the third axis are the same, and are equal in magnitude and opposite in sign to the resistance value changes generated by the second bridge arm and the fourth bridge arm in sensing the magnetic field along the third axis.

5. The TMR magnetic sensor according to claim 1 or 4, characterized in that, The first magnetoresistive element and the second magnetoresistive element of the first magnetic induction pair are connected in series or in parallel.

6. The TMR magnetic sensor according to claim 4, wherein The number of the first magnetic induction pairs in the first bridge arm, the second bridge arm, the third bridge arm and the fourth bridge arm is two or more, and they are combined in the same series and / or parallel manner.

7. The TMR magnetic sensor according to claim 3, wherein It further includes a plurality of second magnetic induction pairs for sensing the magnetic field of the third axis. Each of the second magnetic induction pairs includes a third magnetoresistive element and a fourth magnetoresistive element. The number and combination mode of the magnetic tunnel junctions of the third magnetoresistive element and the fourth magnetoresistive element are the same as those of the magnetic tunnel junctions of the first magnetoresistive element and the second magnetoresistive element. The magnetic tunnel junctions of the third magnetoresistive element and the fourth magnetoresistive element are respectively arranged on the first inclined surface and the second inclined surface of another inclined structure on the same axis. The pinning direction of the magnetic tunnel junction of the third magnetoresistive element is the same as that of the magnetic tunnel junction of the first magnetoresistive element, and the pinning direction of the magnetic tunnel junction of the fourth magnetoresistive element is the same as that of the magnetic tunnel junction of the second magnetoresistive element; The initial magnetization directions of the magnetic tunnel junctions of the third magnetoresistive element and the fourth magnetoresistive element are the same as those of the magnetic tunnel junctions of the first magnetoresistive element and the second magnetoresistive element; the first magnetoresistive element and the fourth magnetoresistive element correspond to the same coil bar, and the second magnetoresistive element and the third magnetoresistive element correspond to another same coil bar.

8. The TMR magnetic sensor according to claim 7, wherein A plurality of the first magnetic induction pairs and a plurality of the second magnetic induction pairs form a bridge. The bridge includes a first bridge arm, a second bridge arm, a third bridge arm and a fourth bridge arm. One end of the first bridge arm is connected to the voltage input terminal, and the other end is connected to the first signal output terminal. One end of the second bridge arm is connected to the first signal output terminal, and the other end is connected to the ground terminal; one end of the third bridge arm is connected to the ground terminal, and the other end is connected to the second signal output terminal; one end of the fourth bridge arm is connected to the second signal output terminal, and the other end is connected to the voltage input terminal; The first bridge arm, the second bridge arm, the third bridge arm and the fourth bridge arm are formed by the same number of first magnetic induction pairs and second magnetic induction pairs, and are combined in the same way; the initial magnetization directions of the magnetic tunnel junctions of the first magnetoresistive element, the second magnetoresistive element, the third magnetoresistive element and the fourth magnetoresistive element of the first magnetic induction pairs constituting the first bridge arm and the fourth bridge arm are the same, and are opposite in sign on the first axis to the initial magnetization directions of the magnetic tunnel junctions of the first magnetoresistive element, the second magnetoresistive element, the third magnetoresistive element and the fourth magnetoresistive element of the first magnetic induction pairs constituting the second bridge arm and the third bridge arm; The resistance value changes generated by the first bridge arm and the third bridge arm sensing the magnetic field of the third axis are the same, and are equal in magnitude and opposite in sign to the resistance value changes generated by the second bridge arm and the fourth bridge arm sensing the magnetic field of the third axis.

9. The TMR magnetic sensor according to claim 7 or 8, characterized in that, The third magnetoresistive element and the fourth magnetoresistive element of the second magnetic induction pair are connected in series or in parallel.

10. The TMR magnetic sensor according to claim 8, characterized in that, Among the first bridge arm, the second bridge arm, the third bridge arm, and the fourth bridge arm, the number of the first magnetic induction pairs and the second magnetic induction pairs is respectively one, two, or more than two, and they are combined in the same series and / or parallel manner.

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