Full-bridge reluctance sensor and electronic device

Abstract

The application provides a full-bridge magnetoresistance sensor and an electronic device. The circuit structure of the full-bridge magnetoresistance sensor is a full-bridge circuit structure, and the long axis directions of each sensing unit on adjacent bridge arms in the full-bridge circuit structure are parallel. The sensing unit comprises a flip function layer, a dielectric layer and a magnetoresistance thin film arranged from bottom to top. The flip function layers of the sensing units on two parallel bridge arms are connected to the same current input end, and the flip function layers of the sensing units on the other two parallel bridge arms are connected to the same ground end. By applying a single current to the current input end, the current flowing through the flip function layers of the adjacent bridge arms is opposite, so that the pinning direction of the anti-ferromagnetic layer of the sensing unit in which the heat generated by the flip function layer and the local magnetic field are reversed is opposite, and then the magnetization direction of the reference layer in the sensing unit on the adjacent bridge arm is opposite, so that a complete full-bridge structure is realized on a single chip, and the effect of flexibly setting or resetting the reference layer direction after production or during use can be achieved.

Description

Technical Field

[0001] This application relates to the field of magnetic electronic devices, and more particularly to a full-bridge magnetoresistive sensor and electronic device. Background Technology

[0002] Magnetoresistive sensors are widely used in position detection, current detection, navigation, and consumer electronics due to their advantages such as high sensitivity, small size, and ease of integration. Among them, magnetoresistive sensors based on magnetic tunnel junctions (MTJs) have attracted much attention in recent years. They detect magnetic fields by changing the direction of the free layer magnetization under the influence of an external magnetic field, thereby causing a change in resistance.

[0003] To achieve good linear output and high sensitivity, magnetoresistive sensors typically employ a Wheatstone full-bridge structure. This means the magnetoresistive sensor is a full-bridge magnetoresistive sensor, which uses multiple individual magnetic tunnel junction device units to form a full-bridge circuit. The magnetic layers in different bridge arms need to have different magnetization directions to obtain opposite resistance change trends, thereby achieving differential output.

[0004] However, in actual manufacturing, the orientation of the magnetic layer needs to be set through external magnetic field annealing or permanent magnets. This necessitates the assembly, packaging, or complex magnetic structure design of multiple individual magnetic tunnel junction device units to realize magnetoresistive sensors. The magnetization orientation of different bridge arms often depends on layout rotation or multiple magnetic field treatments, resulting in high process complexity and making it difficult to achieve a completely symmetrical full-bridge structure on a single chip. Furthermore, the pinning orientation of magnetoresistive sensors is usually set through overall magnetic field annealing, and once annealing is complete, the magnetization orientation of the reference layer is difficult to readjust. If bias drift or device mismatch occurs during device packaging or use, subsequent correction is difficult. Summary of the Invention

[0005] This application provides a full-bridge magnetoresistive sensor and electronic device that can realize a complete full-bridge structure on a single chip, and the reference layer orientation can be flexibly set or reset after fabrication or during use.

[0006] In a first aspect, this application provides a full-bridge magnetoresistive sensor. The circuit structure of the full-bridge magnetoresistive sensor is a full-bridge circuit structure. The four arms of the full-bridge circuit structure are each composed of one or more sensing units connected in series and parallel. The major axis directions of the sensing units on adjacent arms of the full-bridge circuit structure are parallel.

[0007] The sensing unit includes, from bottom to top, a flip-out functional layer, a dielectric layer, and a magnetoresistive thin film;

[0008] In the full-bridge circuit structure, the flip-flop functional layers of the sensing units on the two parallel bridge arms are connected to the same current input terminal, and the flip-flop functional layers of the sensing units on the other two parallel bridge arms are connected to the same ground terminal.

[0009] By applying a single current to the current input terminal, the current flowing through the flip-over functional layer of the adjacent bridge arm flows in opposite directions, so that the heat generated by the flip-over functional layer and the pinning direction of the antiferromagnetic layer in the sensing unit of the local magnetic field flip are opposite, thereby making the magnetization direction of the reference layer in the sensing unit of the adjacent bridge arm opposite.

[0010] In some possible implementations, the sensing unit consists of two sub-sensing units whose major axes are perpendicular to each other;

[0011] The ends of the flip-flop functional layers corresponding to the two sub-sensing units are connected and perpendicular to each other.

[0012] In some possible implementations, the flip-flop functional layers of the sensing units on the two tandem bridge arms are connected in series with each other; or,

[0013] The flip-over functional layers of the sensing units on the two diagonal bridge arms are connected in series with each other. When the number of full-bridge circuit structures is at least two, the flip-over functional layers of each diagonal bridge arm of the at least two full-bridge circuit structures are connected in series with each other.

[0014] Secondly, this application provides a full-bridge magnetoresistive sensor. The circuit structure of the full-bridge magnetoresistive sensor is a full-bridge circuit structure. The four arms of the full-bridge circuit structure are each composed of one or more sensing units connected in series and parallel. The major axis directions of the sensing units on adjacent arms of the full-bridge circuit structure are parallel.

[0015] The sensing unit includes, from bottom to top, a flip-out functional layer, a dielectric layer, and a magnetoresistive thin film;

[0016] In the full-bridge circuit structure, the flip-flop functional layers of the sensing units on the two diagonal bridge arms are connected to the same current input terminal and the same ground terminal.

[0017] By applying a single current to the current input terminal, the current flowing through the flip-over functional layer of the diagonal bridge arm is made to flow in the same direction, so that the heat generated by the flip-over functional layer and the pinning direction of the antiferromagnetic layer in the sensing unit of the local magnetic field flip are the same, thereby making the magnetization direction of the reference layer in the sensing unit of the adjacent bridge arm different.

[0018] In some possible implementations, the number of full-bridge circuit structures is at least two, and the flip-over functional layers of each diagonal bridge arm of the at least two full-bridge circuit structures are connected in series to change the magnetization direction of the reference layer on each diagonal bridge arm by applying a single current to the current input terminal.

[0019] The sensing units on each of the diagonal arms share the same flip function layer.

[0020] Thirdly, this application provides a full-bridge magnetoresistive sensor. The circuit structure of the full-bridge magnetoresistive sensor is a full-bridge circuit structure. The four arms of the full-bridge circuit structure are each composed of one or more sensing units connected in series and parallel. The major axis directions of the sensing units on adjacent arms in the full-bridge circuit structure are perpendicular.

[0021] The sensing unit includes, from bottom to top, a flip-out functional layer, a dielectric layer, and a magnetoresistive thin film;

[0022] In the full-bridge circuit structure, the flip-flop functional layers of the sensing units on the two parallel bridge arms are connected to the same current input terminal, and the flip-flop functional layers of the sensing units on the other two parallel bridge arms are connected to the same ground terminal.

[0023] By applying a single current to the current input terminal, the current flowing through the flip-over functional layer of the adjacent bridge arm is made perpendicular, so that the heat generated by the flip-over functional layer and the pinning direction of the antiferromagnetic layer in the sensing unit where the local magnetic field is flipped are perpendicular, thereby making the magnetization direction of the reference layer in the sensing unit on the adjacent bridge arm perpendicular.

[0024] In some possible implementations, the heat generated by the flip-over functional layer is greater than the heat required for the antiferromagnetic layer to rise to its barrier temperature, and less than the heat required for the reference layer to rise to its Curie temperature; and / or,

[0025] The materials of the flip-over functional layer include tantalum nitride, bismuth telluride, and bismuth selenide.

[0026] In some possible implementations, the magnetoresistive thin film includes an antiferromagnetic layer, a reference layer, a barrier layer, and a free layer arranged sequentially along a direction away from the flip-functional layer;

[0027] The magnetization direction of the free layer is perpendicular to the magnetization direction of the reference layer.

[0028] In some possible implementations, the magnetoresistive film is composed of a plurality of sub-magnetoresistive films connected in series.

[0029] Fourthly, embodiments of this application provide an electronic device including the aforementioned full-bridge magnetoresistive sensor.

[0030] The full-bridge magnetoresistive sensor and electronic device provided in this application embodiment, by setting a flip-flop functional layer and a dielectric layer, utilizes the heat generated by the current in the flip-flop functional layer to trigger a local magnetic field, causing the pinning direction of the antiferromagnetic layer of the sensing unit on at least some bridge arms to flip, thereby changing the magnetization direction of the reference layer. This results in the magnetization directions of the reference layers of adjacent bridge arms being opposite or perpendicular, enabling the realization of a complete full-bridge magnetoresistive sensor structure on a single chip. This eliminates the need for splicing, packaging, or complex magnetic structure designs of multiple individual sensing units, and avoids the complex processes such as layout rotation or multiple magnetic field processing used when setting the magnetization direction of the reference layer for different bridge arms. This simplifies the manufacturing process of the full-bridge magnetoresistive sensor structure and allows for selective changing of the reference layer magnetization direction of a target bridge arm via current writing, supporting direction correction according to actual needs after manufacturing or during use. During the reference layer magnetization direction setting process, the current does not flow directly through the magnetoresistive film, reducing magnetoresistive film damage and improving the long-term reliability of the device. Furthermore, the magnetization direction of the reference layer can be reset by applying a single current to the flip function layer, making the reset convenient; and by combining the setting of the long axis direction of the sensing unit, single-axis magnetic field detection or dual-axis magnetic field detection can be achieved, improving detection accuracy. Attached Figure Description

[0031] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0032] Figure 1 A schematic diagram of a full-bridge circuit structure for realizing uniaxial magnetic field detection provided in this application;

[0033] Figure 2 for Figure 1 A schematic diagram of a flip-flop functional layer corresponding to the full-bridge circuit structure;

[0034] Figure 3 A schematic diagram of a sensing unit provided in this application;

[0035] Figure 4 Linear graph of the reference layer before flipping provided in this application;

[0036] Figure 5 Linear graph of the reference layer after flipping provided in this application;

[0037] Figure 6 for Figure 1 A schematic diagram of another flip-flop functional layer corresponding to the full-bridge circuit structure;

[0038] Figure 7 A schematic diagram of the current of the sensing units of the two diagonal arms provided in this application;

[0039] Figure 8A schematic diagram of the current of the sensing units for the other two diagonal arms of the bridge provided in this application;

[0040] Figure 9 A schematic diagram of a full-bridge circuit structure for realizing dual-axis magnetic field detection provided in this application;

[0041] Figure 10 for Figure 9 A schematic diagram of a flip-flop functional layer corresponding to the full-bridge circuit structure;

[0042] Figure 11 A schematic diagram of the magnetization direction of the sensing units of the two diagonal arms provided in this application;

[0043] Figure 12 for Figure 11 The corresponding current diagram;

[0044] Figure 13 A schematic diagram of the magnetization direction of the sensing units of the other two diagonal arms provided in this application;

[0045] Figure 14 for Figure 13 The corresponding current diagram;

[0046] Figure 15 for Figure 1 A schematic diagram of another type of flip-flop functional layer corresponding to the full-bridge circuit structure;

[0047] Figure 16 for Figure 1 A schematic diagram of another type of flip-flop functional layer corresponding to the full-bridge circuit structure;

[0048] Figure 17 A schematic diagram of another full-bridge circuit structure for realizing uniaxial magnetic field detection provided in this application;

[0049] Figure 18 for Figure 17 A schematic diagram of a flip-over functional layer corresponding to multiple full-bridge circuit structures in the diagram;

[0050] Figure 19 for Figure 17 A schematic diagram of another flip-functional layer corresponding to multiple full-bridge circuit structures in the diagram;

[0051] Figure 20 A schematic diagram of another full-bridge circuit structure for implementing dual-axis magnetic field detection provided in this application;

[0052] Figure 21 for Figure 20 A schematic diagram of the flip-flop functional layer corresponding to the full-bridge circuit structure in the diagram;

[0053] Figure 22 for Figure 20A schematic diagram of the sensing units on the two diagonal arms of the full-bridge circuit structure in the diagram;

[0054] Figure 23 for Figure 20 The schematic diagram of the sensing units on the other two diagonal arms of the full-bridge circuit structure.

[0055] Explanation of reference numerals in the attached figures:

[0056] 10-Bridge arm;

[0057] 20 - Sensing Units;

[0058] 20a-Sub-sensing unit;

[0059] 30 - Flip the functional layer;

[0060] 40 - Dielectric layer;

[0061] 50-Magnetoresistive thin film;

[0062] 50a-sub magnetoresistive film;

[0063] 51-Seed layer;

[0064] 52-Antiferromagnetic layer;

[0065] 53-Fixed layer;

[0066] 54-Coupling layer;

[0067] 55 - Reference layer;

[0068] 56 - Barrier layer;

[0069] 57-Free layer;

[0070] 58-Electrode layer;

[0071] 60 - Interconnect layer;

[0072] 70 - Current input terminal;

[0073] 80 - Grounding terminal.

[0074] The accompanying drawings have illustrated specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to specific embodiments. Detailed Implementation

[0075] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0076] Full-bridge magnetoresistive sensors are difficult to fabricate with a complete full-bridge structure on a single chip, and it is also difficult to flexibly set or reset the reference layer orientation after fabrication or during use. Inventors have attempted to change the state of the reference layer through spin-orbit torque or current heating, but these methods often require direct current application to the magnetic tunnel junction structure, which can easily lead to damage to the tunneling barrier layer or decreased reliability. Furthermore, while differential response can be achieved by placing permanent magnets or complex magnetic structures outside the chip, such solutions are not conducive to chip-level integration and increase system complexity. If the pinning direction of the magnetoresistive sensor reference layer is set through overall magnetic field annealing, once annealing is complete, if bias drift or device mismatch occurs during device packaging or use, the magnetization direction of the reference layer is difficult to readjust.

[0077] The full-bridge magnetoresistive sensor and electronic device provided in this application utilize the heat generated by the flip-function layer current to trigger a local magnetic field, causing the pinning direction of the antiferromagnetic layer of the sensing unit on at least some bridge arms to flip, thereby changing the magnetization direction of the reference layer. This results in the magnetization directions of the reference layers of adjacent bridge arms being opposite or perpendicular. A complete full-bridge magnetoresistive sensor structure can be realized on a single chip, eliminating the need for splicing, packaging, or complex magnetic structure designs of multiple individual sensing units. It also avoids the complex processes such as layout rotation or multiple magnetic field processing used when setting the magnetization direction of the reference layer of different bridge arms, simplifying the manufacturing process of the full-bridge magnetoresistive sensor structure. Furthermore, it can selectively change the magnetization direction of the reference layer of a target bridge arm through current writing, supporting direction correction according to actual needs after manufacturing or during use, thus improving the design flexibility of the full-bridge magnetoresistive sensor. During the setting of the reference layer magnetization direction, a dielectric layer is used to isolate the flip-function layer and the magnetoresistive film, preventing the current in the flip-function layer from flowing through the magnetoresistive film, reducing magnetoresistive film damage, and improving the long-term reliability of the device. The magnetization direction of the reference layer can be reset by applying a single current to the flip function layer, which is convenient for resetting; and by combining the setting of the long axis direction of the sensing unit, single-axis magnetic field detection or dual-axis magnetic field detection can be realized, thereby improving the detection accuracy.

[0078] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings.

[0079] In the first aspect, embodiments of this application provide a full-bridge magnetoresistive sensor, which refers to a detection device with a full-bridge circuit structure (Wheatstone bridge structure). The full-bridge circuit structure can realize the DC to AC inverter function and can be applied to angle measurement, current detection and position sensing, etc.

[0080] See Figures 1 to 14 The circuit structure of the full-bridge magnetoresistive sensor is a full-bridge circuit structure. The four bridge arms 10 of the full-bridge circuit structure are each composed of one or more sensing units 20 connected in series and parallel. In the full-bridge circuit structure, the long axis directions of the sensing units 20 on adjacent bridge arms 10 are parallel. The sensing unit 20 includes: a flip-flop functional layer 30, a dielectric layer 40 and a magnetoresistive thin film 50 arranged from bottom to top. In the full-bridge circuit structure, the flip-flop functional layers 30 of the sensing units 20 on two parallel bridge arms 10 are connected to the same current input terminal 70, and the flip-flop functional layers 30 of the sensing units 20 on the other two parallel bridge arms 10 are connected to the same ground terminal 80. By applying a single current to the current input terminal 70, the current flowing through the flip-flop functional layers 30 of adjacent bridge arms 10 flows in opposite directions, so that the heat generated by the flip-flop functional layer 30 and the pinning direction of the antiferromagnetic layer 52 in the sensing unit 20 with local magnetic field reversal are opposite, thereby making the magnetization direction of the reference layer 55 in the sensing unit 20 of adjacent bridge arms 10 opposite.

[0081] The full-bridge circuit structure includes four bridge arms 10. Two adjacent bridge arms 10 are called adjacent bridge arms; bridge arms 10 connected to the same node and bearing the same voltage are called parallel bridge arms; and two bridge arms 10 located diagonally are called diagonal bridge arms (also opposite bridge arms). Figure 1 Taking the orientation shown as an example, the four bridge arms 10 are the upper bridge arm of the left half bridge, the lower bridge arm of the left half bridge, the upper bridge arm of the right half bridge, and the lower bridge arm of the right half bridge. Taking the upper bridge arm of the left half bridge as an example, the upper bridge arm of the left half bridge and the lower bridge arm of the left half bridge are adjacent bridge arms and are also connected in series. The upper bridge arm of the left half bridge and the upper bridge arm of the right half bridge are also adjacent bridge arms. The upper bridge arm of the left half bridge and the upper bridge arm of the right half bridge are parallel bridge arms. The upper bridge arm of the left half bridge and the lower bridge arm of the right half bridge are diagonal bridge arms.

[0082] Each of the four bridge arms 10 includes at least one sensing unit 20. When any bridge arm 10 includes two or more sensing units 20, the at least two sensing units 20 on the same bridge arm 10 are connected in series, in parallel, or in a mixed series-parallel connection. The major axes of the sensing units 20 in adjacent bridge arms 10 are parallel; for example, the major axes of the sensing units 20 in the four bridge arms 10 are parallel. The major axis of the sensing unit 20 can be a linear axis, such as... Figure 1 and Figure 3 As shown, the major axis of the sensing unit 20 extends along the X direction. The major axis of the sensing unit 20 can be a broken line axis, such as... Figure 9 , Figure 11 and Figure 13 As shown, the sensing unit 20 may have two sub-sensing units 20a with their major axes perpendicular to each other. The major axis of one sub-sensing unit 20a extends along the X direction, and the major axis of the other sub-sensing unit 20a extends along the Y direction. The major axes of the two sub-sensing units 20a are connected to form the major axis of the sensing unit 20.

[0083] The sensing unit 20 includes a flip-flop functional layer 30, a dielectric layer 40, and a magnetoresistive film 50, which are stacked from bottom to top. Current flowing through the flip-flop functional layer 30 generates heat and a local magnetic field, flipping the pinning direction of the antiferromagnetic layer 52 in the sensing unit 20. After the current is removed, the pinning direction of the antiferromagnetic layer 52 remains stable. That is, the change in pinning direction of the antiferromagnetic layer 52 after current is applied to the flip-flop functional layer 30 is not temporary but stable after the current is removed. This allows the exchange bias between the antiferromagnetic layer 52 and the ferromagnetic layer to pin the magnetization direction of adjacent ferromagnetic layers (reference layer 55 or fixed layer 53). The dielectric layer 40 separates the flip-flop functional layer 30 and the magnetoresistive film 50, making them insulated and preventing current from the flip-flop functional layer 30 from entering the magnetoresistive film 50 and affecting the resistive readout operation. The dielectric layer 40 is made of at least one of insulating materials such as silicon oxide, silicon nitride, magnesium oxide, aluminum oxide, and hafnium oxide. The magnetoresistive thin film 50 refers to a thin film exhibiting a magnetoresistive effect, whose resistance changes with the applied magnetic field. Magnetoresistive thin films 50 include, but are not limited to, giant magnetoresistive (GMR) films and tunnel magnetoresistive (TMR) films.

[0084] like Figures 1 to 4As shown, the flip-flop functional layers 30 of the sensing units 20 on the two parallel bridge arms 10 are connected to the same current input terminal 70, and the flip-flop functional layers 30 of the sensing units 20 on the other two parallel bridge arms 10 are connected to the same ground terminal 80. The current input terminal 70 refers to the current input terminal, and the ground terminal 80 refers to the current output terminal. The current flows from the current input terminal 70 to the ground terminal 80. In the initial state, the initial pinning directions of the antiferromagnetic layers 52 of the sensing units 20 on adjacent bridge arms 10 can be parallel, that is, the initial pinning directions of the antiferromagnetic layers 52 of each sensing unit 20 can be the same. Each sensing unit 20 can be annealed along a set direction (such as the minor axis direction) to ensure that the initial pinning directions of the antiferromagnetic layers 52 of each sensing unit 20 are the same.

[0085] A single current is applied to the current input terminal 70. A single current refers to a non-continuous, periodic current pulse that occurs only once. The current flowing through the flip-flop functional layer 30 of the adjacent bridge arm 10 flows in opposite directions. The flip-flop functional layer 30 generates heat and a local magnetic field, which uses a thermo-magnetic coupling mechanism to flip the pinning direction of the antiferromagnetic layer 52 of the sensing unit 20. This results in the pinning direction of the antiferromagnetic layer 52 in the sensing unit 20 of the adjacent bridge arm 10 being opposite, and consequently, the magnetization direction of the reference layer 55 in the sensing unit 20 of the adjacent bridge arm 10 being opposite.

[0086] Understandably, current flows through the flip-over functional layers 30 beneath all four bridge arms 10, and the current flows in opposite directions within the flip-over functional layers 30 of the sensing units 20 in adjacent bridge arms 10. At least some bridge arms 10 experience a reversal of the pinning direction of the antiferromagnetic layer 52 of the sensing unit 20, thereby reversing the magnetization direction of the reference layer 55 of the sensing unit 20 in adjacent bridge arms 10. Ultimately, this results in opposite magnetization directions of the reference layer 55 in any two adjacent bridge arms 10, allowing a complete full-bridge magnetoresistive sensor structure to be achieved with a single current application on the same chip. Furthermore, the current required to flip the reference layer 55 can be reduced by simultaneously applying an external magnetic field.

[0087] like Figure 4 and Figure 5 As shown in the schematic diagram of the sensing linear curves before and after the magnetization direction of the reference layer 55 is reversed, it can be seen that before and after applying current to the flipping functional layer 30, the polarity of the resistance R curves of the reference layer 55 before and after the flipping is opposite, that is, the magnetization direction of the reference layer 55 is opposite, and the response to the external magnetic field is opposite.

[0088] By setting a flip-over functional layer 30 and a reset current path, the magnetization direction of the reference layer 55 in the sensing unit 20 is selectively changed by the current, enabling its controllable flipping. This supports the resetting or correction of the bridge arm 10 direction after manufacturing or during use, improving device maintainability and reliability. The dielectric layer 40 and the thermo-magnetic coupling mechanism prevent the current from directly acting on the magnetoresistive film 50, thereby reducing or avoiding damage to the barrier layer 56 in the magnetoresistive film 50, improving device reliability and lifespan. Furthermore, the full-bridge magnetoresistive sensor structure does not rely on permanent magnets or complex magnetic structures, improving process compatibility. The aforementioned full-bridge magnetoresistive sensor can be implemented on the same chip and under the same manufacturing process, no longer relying on the combination of multiple independent devices or complex external magnetic structures, thereby improving device consistency and integration.

[0089] The heat generated by the flip-flop functional layer 30 is greater than the heat required for the antiferromagnetic layer 52 to reach its blocking temperature, but less than the heat required for the reference layer 55 to reach its Curie temperature. Because the heat generated by the flip-flop functional layer 30 is greater than the heat required for the antiferromagnetic layer 52 to reach its blocking temperature, the antiferromagnetic layer 52 loses its pinning effect. The antiferromagnetic layer 52 can respond to the local magnetic field generated by the current in the flip-flop functional layer 30 below it, causing its internal magnetic moments to rearrange according to the direction of the local magnetic field, thereby changing the pinning direction of the magnetic layer. As the heat dissipates and the temperature drops to the blocking temperature of the antiferromagnetic layer 52, the alignment of its internal magnetic moments tends to stabilize, and the new pinning direction is locked. The heat generated by the flip-flop functional layer 30 is less than the heat required for the reference layer 55 to reach its Curie temperature, which can prevent the reference layer 55 from losing its magnetism, thereby preventing device failure.

[0090] The flip-over functional layer 30 is made of materials including tantalum nitride, bismuth telluride, and bismuth selenide to give it good high-resistivity thermal conductivity. The flip-over functional layer 30 can utilize Joule heating to provide sufficient, localized heat and a localized magnetic field to the antiferromagnetic layer 52 within a time window, thereby changing the pinning direction of the antiferromagnetic layer 52 and shortening the response time for flipping the pinning direction. The choice of material for the flip-over functional layer 30 can improve the efficiency of the thermo-magnetic coupling mechanism.

[0091] like Figure 1 , Figure 2 and Figure 6As shown, the flip-flop functional layers 30 of the sensing units 20 on the two parallel bridge arms 10 are connected to the same current input terminal 70, and the flip-flop functional layers 30 of the sensing units 20 on the other two parallel bridge arms 10 are connected to the same ground terminal 80. In this way, only the current input terminal 70 and the ground terminal 80 need to be set to supply current to the flip-flop functional layers 30, and a single current (i.e., a single current) can make the magnetization direction of the reference layers 55 of the four bridge arms 10 opposite.

[0092] In one possible implementation, the sensing units 20 of each bridge arm 10 have independent flip-flop functional layers 30, and each sensing unit 20 of each bridge arm 10 is connected to one flip-flop functional layer 30, that is, there are at least four flip-flop functional layers 30. The current input terminal 70 connected to each flip-flop functional layer 30 is the same terminal, and the ground terminal 80 connected to each flip-flop functional layer 30 is the same terminal.

[0093] A single current is applied to the current input terminal 70, and this current flows through four independent switching functional layers 30. Furthermore, the current flowing through the switching functional layers 30 of adjacent bridge arms 10 flows in opposite directions, while the current flowing through the switching functional layers 30 of diagonal bridge arms 10 flows in the same direction. This ensures that the pinning directions of the antiferromagnetic layers 52 in the sensing units 20 of adjacent bridge arms 10 are opposite, and the pinning directions of the antiferromagnetic layers 52 in the sensing units 20 of diagonal bridge arms 10 are the same. Consequently, the magnetization directions of the reference layers 55 in the sensing units 20 of adjacent bridge arms 10 are opposite, and the magnetization directions of the reference layers 55 in the sensing units 20 of diagonal bridge arms 10 are the same, thus realizing a full-bridge circuit structure.

[0094] As another possible implementation, such as Figure 1 and Figure 2 As shown, the sensing units 20 on two series-connected bridge arms 10 have their flip-flop functional layers 30 connected in series and sequentially. The flip-flop functional layer 30 of one of these two series-connected bridge arms 10 is connected to the current input terminal 70, and the flip-flop functional layer 30 of the other series-connected bridge arm 10 is connected to the ground terminal 80. Similarly, the sensing units 20 on two other series-connected bridge arms 10 have their flip-flop functional layers 30 connected in series and sequentially. The current input terminal 70 connected to each flip-flop functional layer 30 is the same, and the ground terminal 80 connected to each flip-flop functional layer 30 is the same.

[0095] A single current is applied to the current input terminal 70, and this current flows through two independent switching function layers 30. Furthermore, as... Figure 7 and Figure 8 As shown, the current flowing through the flip-flop functional layer 30 of adjacent bridge arms 10 flows in opposite directions, while the current flowing through the flip-flop functional layer 30 of diagonal bridge arms 10 flows in the same direction. This makes the pinning direction of the antiferromagnetic layer 52 in the sensing unit 20 of adjacent bridge arms 10 opposite, and the pinning direction of the antiferromagnetic layer 52 in the sensing unit 20 of diagonal bridge arms 10 the same. This makes the magnetization direction of the reference layer 55 in the sensing unit 20 of adjacent bridge arms 10 opposite, and the magnetization direction of the reference layer 55 in the sensing unit 20 of diagonal bridge arms 10 the same, thus realizing a full-bridge circuit structure.

[0096] As another possible implementation method, such as Figure 1 and Figure 6 As shown, the sensing units 20 on the two diagonal bridge arms 10 are connected in series with each other and sequentially connected to the flip-flop functional layer 30. The flip-flop functional layer 30 of the sensing unit 20 in one of the two diagonal bridge arms 10 is connected to the current input terminal 70, and the flip-flop functional layer 30 of the sensing unit 20 in the other diagonal bridge arm 10 is connected to the ground terminal 80. Similarly, the sensing units 20 on the other two diagonal bridge arms 10 are connected in series with each other and sequentially connected to the flip-flop functional layer 30. The flip-flop functional layer 30 of the sensing unit 20 in one of the two diagonal bridge arms 10 is connected to the current input terminal 70, and the flip-flop functional layer 30 of the sensing unit 20 in the other diagonal bridge arm 10 is connected to the ground terminal 80. For example, the sensing units 20 in the two diagonal bridge arms 10 share one flip-flop functional layer 30, and the sensing units 20 in the other two diagonal bridge arms 10 also share one flip-flop functional layer 30. The current input terminal 70 connected to each of the flip-flop functional layers 30 is the same terminal, and the ground terminal 80 connected to each of the flip-flop functional layers 30 is the same terminal.

[0097] A single current is applied to the current input terminal 70, and this current flows through two independent switching function layers 30. Furthermore, as... Figure 7 and Figure 8 As shown, the current flowing through the flip-flop functional layer 30 of adjacent bridge arms 10 flows in opposite directions, while the current flowing through the flip-flop functional layer 30 of diagonal bridge arms 10 flows in the same direction. This makes the pinning direction of the antiferromagnetic layer 52 in the sensing unit 20 of adjacent bridge arms 10 opposite, and the pinning direction of the antiferromagnetic layer 52 in the sensing unit 20 of diagonal bridge arms 10 the same. This makes the magnetization direction of the reference layer 55 in the sensing unit 20 of adjacent bridge arms 10 opposite, and the magnetization direction of the reference layer 55 in the sensing unit 20 of diagonal bridge arms 10 the same, thus realizing a full-bridge circuit structure.

[0098] When there are at least two full-bridge circuit structures, the flip-flop functional layers 30 of each diagonal bridge arm 10 of the at least two full-bridge circuit structures are connected in series. By applying a single current to the current input terminal 70, the magnetization direction of the reference layer 55 on each diagonal bridge arm 10 is changed simultaneously. In this way, a shared flip-flop functional layer 30 can be designed across the entire wafer level, allowing sensing units 20 with the same reference layer 55 magnetization direction to share the same flip-flop functional layer 30, thus reducing structural complexity.

[0099] In another possible implementation, the sensing units 20 on the two series-connected bridge arms 10 are connected in series with their flip-flop functional layers 30, sequentially. The flip-flop functional layer 30 of one of the two series-connected bridge arms 10 is connected to a current input terminal 70, and the flip-flop functional layer 30 of the sensing unit 20 on the other series-connected bridge arm 10 is connected to a ground terminal 80. The sensing units 20 on the other two series-connected bridge arms 10 are each connected to a flip-flop functional layer 30. For example, the sensing units 20 in the two series-connected bridge arms 10 share a single flip-flop functional layer 30, while the sensing units 20 in the other two series-connected bridge arms 10 each correspond to a single flip-flop functional layer 30. The current input terminal 70 connected to each flip-flop functional layer 30 is the same terminal, and the ground terminal 80 connected to each flip-flop functional layer 30 is the same terminal.

[0100] A single current is applied to the current input terminal 70, and this current flows through three independent switching function layers 30. Furthermore, as... Figure 7 and Figure 8 As shown, the current flowing through the flip-flop functional layer 30 of adjacent bridge arms 10 flows in opposite directions, while the current flowing through the flip-flop functional layer 30 of diagonal bridge arms 10 flows in the same direction. This makes the pinning direction of the antiferromagnetic layer 52 in the sensing unit 20 of adjacent bridge arms 10 opposite, and the pinning direction of the antiferromagnetic layer 52 in the sensing unit 20 of diagonal bridge arms 10 the same. This makes the magnetization direction of the reference layer 55 in the sensing unit 20 of adjacent bridge arms 10 opposite, and the magnetization direction of the reference layer 55 in the sensing unit 20 of diagonal bridge arms 10 the same, thus realizing a full-bridge circuit structure.

[0101] In another possible implementation, the sensing units 20 on the two diagonal bridge arms 10 are connected in series with their flip-flop functional layers 30, and are sequentially connected. The flip-flop functional layer 30 of one of the two diagonal bridge arms 10 is connected to a current input terminal 70, and the flip-flop functional layer 30 of the sensing unit 20 on the other diagonal bridge arm 10 is connected to a ground terminal 80. The sensing units 20 on the other two diagonal bridge arms 10 are each connected to a flip-flop functional layer 30. For example, the sensing units 20 in the two diagonal bridge arms 10 share a single flip-flop functional layer 30, while the sensing units 20 in the other two diagonal bridge arms 10 each correspond to a single flip-flop functional layer 30. The current input terminal 70 connected to each flip-flop functional layer 30 is the same terminal, and the ground terminal 80 connected to each flip-flop functional layer 30 is the same terminal.

[0102] A single current is applied to the current input terminal 70, and this current flows through three independent switching function layers 30. Furthermore, as... Figure 7 and Figure 8 As shown, the current flowing through the flip-flop functional layer 30 of adjacent bridge arms 10 flows in opposite directions, while the current flowing through the flip-flop functional layer 30 of diagonal bridge arms 10 flows in the same direction. This makes the pinning direction of the antiferromagnetic layer 52 in the sensing unit 20 of adjacent bridge arms 10 opposite, and the pinning direction of the antiferromagnetic layer 52 in the sensing unit 20 of diagonal bridge arms 10 the same. This makes the magnetization direction of the reference layer 55 in the sensing unit 20 of adjacent bridge arms 10 opposite, and the magnetization direction of the reference layer 55 in the sensing unit 20 of diagonal bridge arms 10 the same, thus realizing a full-bridge circuit structure.

[0103] In an example where the sensing unit 20 includes two sub-sensing units 20a with their major axes perpendicular to each other, see [reference needed]. Figure 9 and Figure 10 The ends of the flip-flop functional layers 30 corresponding to the two sub-sensing units 20a are connected and perpendicular to each other. In this way, each sensing unit 20 can independently sense changes in magnetic fields in different directions, achieving dual-axis detection without the need for additional combinations. For example, as... Figures 11 to 14 As shown, one sub-sensing unit 20a in the sensing unit 20 responds to the magnetic field in the X direction, and the other sub-sensing unit 20a responds to the magnetic field in the Y direction. Combined with the controllable reversal of the magnetization direction of the reference layer 55, dual-axis magnetic field detection can be achieved in a single full-bridge magnetoresistive sensor, avoiding the area and complexity issues caused by combinations of multiple bridge arms 10 or multiple sensing units 20. Simultaneously, the detection accuracy is improved through the vertical magnetic field separation capability, providing a more efficient implementation path for single-chip dual-axis detection.

[0104] See Figure 3The magnetoresistive thin film 50 includes an antiferromagnetic layer 52, a reference layer 55, a barrier layer 56, and a free layer 57 sequentially disposed along a direction away from the flip-over functional layer 30; the magnetization direction of the free layer 57 is perpendicular to the magnetization direction of the reference layer 55. The antiferromagnetic layer 52, reference layer 55, barrier layer 56, and free layer 57 are stacked and constitute the core component of the magnetoresistive thin film 50. The magnetization direction of the free layer 57 is perpendicular to the magnetization direction of the reference layer 55, as shown below. Figure 3 As shown, the magnetization direction of the reference layer 55 is the X direction, and the magnetization direction of the free layer 57 is perpendicular to the plane of the paper, so as to achieve an orthogonal configuration, thereby realizing magnetic field sensing, etc.

[0105] In this design, the magnetization direction of the free layer 57 can be altered by external factors, exhibiting low coercivity and easy flipping. The barrier layer 56 contacts both the reference layer 55 and the free layer 57, serving to separate them while allowing quantum tunneling current to pass through, generating a tunneling magnetoresistance effect. The reference layer 55 provides a fixed magnetization direction as a reference. Under the pinning effect of the antiferromagnetic layer 52, the magnetization direction of the reference layer 55 remains essentially unchanged during normal operation. The antiferromagnetic layer 52 is used to pin the magnetization direction of the reference layer 55; after exchanging bias coupling with the reference layer 55, it fixes the magnetization direction of the reference layer 55, making it less susceptible to change by external factors.

[0106] The antiferromagnetic layer 52 can be made of an antiferromagnetic material, such as a manganese alloy, and may include at least one of platinum manganese, iridium manganese, nickel manganese, and iron manganese. The reference layer 55 and the free layer 57 are both made of ferromagnetic materials, including at least one of cobalt iron boron, cobalt iron, iron boron, cobalt boron, and nickel iron. The reference layer 55 and the free layer 57 can be a single layer or multiple layers; for example, the free layer 57 can be a composite film of cobalt iron boron / tantalum / nickel iron. The barrier layer 56 can be made of an insulating material, such as an oxide, and may include at least one of aluminum oxide and magnesium oxide.

[0107] In some possible examples, other layers may also be present between the antiferromagnetic layer 52 and the reference layer 55. For example, a fixed layer 53 and a coupling layer 54 may be disposed between the antiferromagnetic layer 52 and the reference layer 55. The antiferromagnetic layer 52, fixed layer 53, coupling layer 54, and reference layer 55 are stacked sequentially to form a synthetic antiferromagnetic (SAF) structure. The magnetization direction of the fixed layer 53 is firmly fixed by the antiferromagnetic layer 52 through the exchange bias effect. The coupling layer 54 is used to provide strong interlayer exchange coupling, making the magnetization directions of the fixed layer 53 and the reference layer 55 strictly parallel or antiparallel. The magnetization direction of the reference layer 55 is antiparallel to that of the fixed layer 53, and the magnetic fields generated by the reference layer 55 and the fixed layer 53 cancel each other out, avoiding interference with the free layer 57.

[0108] The fixing layer 53 is made of a ferromagnetic material, including at least one of cobalt-iron-boron, cobalt-iron, iron-boron, cobalt-boron, and nickel-iron. The fixing layer 53 can be a single layer or multiple layers; for example, it can be a composite film of cobalt-iron-boron / tantalum / nickel-iron. The coupling layer 54 is made of a metal, including at least one of ruthenium, tantalum, iridium, molybdenum, and tungsten. By adjusting the thickness of the coupling layer 54, parallel or antiparallel coupling of the magnetization direction between the fixing layer 53 and the reference layer 55 can be achieved.

[0109] In some possible examples, a seed layer 51 is further disposed between the antiferromagnetic layer 52 and the dielectric layer 40; and / or, an electrode layer 58 is further disposed on the side of the free layer 57 facing away from the barrier layer 56. The seed layer 51 is used to enhance the crystal phase of the antiferromagnetic layer 52, and the material of the seed layer 51 includes at least one of tantalum, ruthenium, platinum, and nickel-iron. The electrode layer 58 is used to conduct current into the magnetoresistive thin film 50, and the material of the electrode layer 58 can be a metal, including at least one of tungsten, tantalum, titanium nitride, and ruthenium.

[0110] See Figure 3 , Figure 7 and Figure 8 The magnetoresistive film 50 is composed of several sub-magnetoresistive films 50a connected in series to improve the equivalent resistance of the magnetoresistive unit, reduce circuit power consumption, and increase the output signal amplitude. The several sub-magnetoresistive films 50a of the magnetoresistive film 50 can be reset through the same flip-flop functional layer 30. Each sub-magnetoresistive film 50a includes an antiferromagnetic layer 52, a reference layer 55, a barrier layer 56, and a free layer 57. The antiferromagnetic layers 52 of two adjacent sub-magnetoresistive films 50a can be an integral structure, spaced apart from the antiferromagnetic layers 52 of adjacent sub-magnetoresistive films 50a; and / or, the reference layers 55 of two adjacent sub-magnetoresistive films 50a can be an integral structure, spaced apart from the reference layers 55 of adjacent sub-magnetoresistive films 50a. The barrier layers 56 of these two sub-magnetoresistive films 50a are independent of each other, and the free layers 57 are independent of each other.

[0111] For example, the magnetoresistive film 50 on one bridge arm 10 includes six sub-magnetoresistive films 50a connected in series. Of course, the number of sub-magnetoresistive films 50a on one bridge arm 10 is not limited to this; it can be more or less, and its structural form can refer to the case of six sub-magnetoresistive films 50a. For ease of description, these six sub-magnetoresistive films 50a are respectively the first sub-magnetoresistive film, the second sub-magnetoresistive film, the third sub-magnetoresistive film, the fourth sub-magnetoresistive film, the fifth sub-magnetoresistive film, and the sixth sub-magnetoresistive film. The first to sixth sub-magnetoresistive films all include an antiferromagnetic layer 52, a reference layer 55, a barrier layer 56, and a free layer 57.

[0112] In this design, the first and second sub-magnetoresistive films share an antiferromagnetic layer 52 and / or a reference layer 55, meaning the antiferromagnetic layers 52 of the first and second sub-magnetoresistive films are integral structures and / or the reference layers 55 of the first and second sub-magnetoresistive films are integral structures. Barrier layers 56 of the first and second sub-magnetoresistive films are spaced apart, and free layers 57 of the first and second sub-magnetoresistive films are spaced apart. The third and fourth sub-magnetoresistive films share an antiferromagnetic layer 52 and / or a reference layer 55, with barrier layers 56 of the third and fourth sub-magnetoresistive films spaced apart, and free layers 57 of the third and fourth sub-magnetoresistive films spaced apart. The fifth and sixth sub-magnetoresistive films share an antiferromagnetic layer 52 and / or a reference layer 55, with barrier layers 56 of the fifth and sixth sub-magnetoresistive films spaced apart, and free layers 57 of the fifth and sixth sub-magnetoresistive films spaced apart.

[0113] Specifically, each of the first to sixth sub-magnetoresistive films further includes at least one of a seed layer 51, a fixing layer 53, a coupling layer 54, and an electrode layer 58. The electrode layers 58 of the first to sixth sub-magnetoresistive films are independent of each other. The first and second sub-magnetoresistive films may share the fixing layer 53 and / or the coupling layer 54 and / or the seed layer 51. The third and fourth sub-magnetoresistive films may share the fixing layer 53 and / or the coupling layer 54 and / or the seed layer 51. The fifth and sixth sub-magnetoresistive films may share the fixing layer 53 and / or the coupling layer 54 and / or the seed layer 51.

[0114] For example, the first and second sub-magnetoresistive films share a seed layer 51, an antiferromagnetic layer 52, a fixing layer 53, a coupling layer 54, and a reference layer 55; the third and fourth sub-magnetoresistive films share the same seed layer 51, antiferromagnetic layer 52, fixing layer 53, coupling layer 54, and reference layer 55; and the fifth and sixth sub-magnetoresistive films share the same seed layer 51, antiferromagnetic layer 52, fixing layer 53, coupling layer 54, and reference layer 55. The electrode layers 58 of the second and third sub-magnetoresistive films are connected through an interconnect layer 60, the electrode layers 58 of the fourth and fifth sub-magnetoresistive films are connected through an interconnect layer 60, and the electrode layers 58 of the first and sixth sub-magnetoresistive films are externally connected through an interconnect layer 60.

[0115] Combination Figure 7 and Figure 8In each of the four bridge arms 10, the magnetoresistive film 50 of the sensing unit 20 includes several sub-magnetoresistive films 50a connected in series. The sub-magnetoresistive films 50a of the same magnetoresistive film 50 share the same flip-flop functional layer 30 and dielectric layer 40. The current flow direction in the flip-flop functional layer 30 of the lower layers of two diagonal bridge arms 10 is the same, and the current flow direction in the magnetoresistive films 50 of the upper layers of these two diagonal bridge arms 10 is also the same. This is opposite to the current flow direction in the flip-flop functional layer 30 of the lower layers of the other two diagonal bridge arms 10, and the current flow direction in the magnetoresistive films 50 of the upper layers of these two diagonal bridge arms 10.

[0116] like Figure 7 and Figure 8 As shown, the magnetoresistive thin film 50 on the upper layer of the two diagonal bridge arms 10 includes multiple sub-magnetoresistive thin films 50a, and the two sub-magnetoresistive thin films 50a share a reference layer 55. The current flows through the reference layer 55 and the interconnect layer 60 in sequence through the multiple sub-magnetoresistive thin films 50a. The full-bridge circuit structure can sense the magnitude of the external magnetic field by reading the series resistance.

[0117] In the full-bridge magnetoresistive sensor provided in this application embodiment, the long axes of the sensing units 20 on adjacent bridge arms 10 are parallel, and the current flowing through the flip-flop functional layer 30 of adjacent bridge arms 10 flows in opposite directions. The current in the flip-flop functional layer 30 generates heat and triggers a local magnetic field, causing the pinning direction of the antiferromagnetic layer 52 of the sensing units 20 on the four bridge arms 10 to flip, thereby changing the magnetization direction of the reference layer 55. This results in the reference layers 55 of adjacent bridge arms 10 having opposite magnetization directions, enabling the realization of a complete full-bridge magnetoresistive sensor structure on a single chip. This eliminates the need for splicing, packaging, or complex magnetic structure designs of multiple individual sensing units 20, and avoids complex processes such as layout rotation or multiple magnetic field processing required when setting the magnetization direction of the reference layers 55 of different bridge arms 10. This simplifies the manufacturing process of the full-bridge magnetoresistive sensor structure and allows for selective changing of the magnetization direction of the reference layer 55 of a target bridge arm through current writing, supporting direction correction according to actual needs after manufacturing or during use. During the setting of the magnetization direction of the reference layer 55, the current does not flow directly through the magnetoresistive film 50, reducing damage to the magnetoresistive film 50 and improving the long-term reliability of the device. In addition, the magnetization direction of the reference layer 55 can be reset by applying a single current in the flip function layer 30, which is convenient for resetting; and by combining it with the setting of the long axis direction of the sensing unit 20, single-axis magnetic field detection or dual-axis magnetic field detection can be realized, improving the detection accuracy.

[0118] Secondly, embodiments of this application provide a full-bridge magnetoresistive sensor, see reference. Figure 1 , Figures 15 to 19The circuit structure of the full-bridge magnetoresistive sensor is a full-bridge circuit structure. The four bridge arms 10 of the full-bridge circuit structure are each composed of one or more sensing units 20 connected in series and parallel. The long axis directions of the sensing units 20 on adjacent bridge arms 10 are parallel. The sensing unit 20 includes: a flip-over functional layer 30, a dielectric layer 40 and a magnetoresistive film 50 arranged from bottom to top. In the full-bridge circuit structure, the flip-over functional layers 30 of the sensing units 20 on two diagonal bridge arms 10 are connected to the same current input terminal 70 and the same ground terminal 80. By applying a single current to the current input terminal 70, the current flowing through the flip-over functional layers 30 of the diagonal bridge arms 10 is made to flow in the same direction, so that the heat generated by the flip-over functional layer 30 and the pinning direction of the antiferromagnetic layer 52 in the sensing unit 20 with local magnetic field flipping are the same, thereby making the magnetization direction of the reference layer 55 in the sensing unit 20 of adjacent bridge arms 10 different. The meaning, materials, and structure of the full-bridge circuit structure, sensing unit 20, and flip-flop functional layer 30 can be referred to the first aspect above, and will not be repeated here.

[0119] See Figure 1 , Figure 15 and Figure 16 In the full-bridge circuit structure, the sensing units 20 on two diagonal bridge arms 10 are equipped with a flip-over function layer 30, while the sensing units 20 on the other two diagonal bridge arms 10 are not equipped with a flip-over function layer 30. That is, two diagonal bridge arms 10 form one group, and the other two diagonal bridge arms 10 form another group, one group equipped with a flip-over function layer 30, and the other group without a flip-over function layer 30. The flip-over function layers 30 of the sensing units 20 on the two diagonal bridge arms 10 are connected to the same current input terminal 70 and the same ground terminal 80. By applying a single current to the current input terminal 70, independent control of the local bridge arms 10 can be achieved, making the pinning directions of adjacent bridge arms 10 opposite or perpendicular, thereby realizing single-axis magnetic field detection or dual-axis magnetic field detection.

[0120] The current input terminal 70 refers to the current input terminal, and the grounding terminal 80 refers to the current output terminal. The current flows from the current input terminal 70 to the grounding terminal 80. A single current refers to a non-continuous, periodic pulse current that occurs only once. The current flowing through the flip-flop functional layer 30 of the diagonal bridge arm 10 flows in the same direction. The flip-flop functional layer 30 generates heat and a local magnetic field, which uses a thermo-magnetic coupling mechanism to flip the pinning direction of the antiferromagnetic layer 52 of the sensing unit 20. This results in different pinning directions of the antiferromagnetic layer 52 in the sensing unit 20 of adjacent bridge arms 10, and consequently, different magnetization directions of the reference layer 55 in the sensing unit 20 of adjacent bridge arms 10.

[0121] Specifically, considering the positional relationship of the major axes of the sensing units 20 on adjacent bridge arms 10, after applying a single current to the current inlet 70, the pinning directions of the antiferromagnetic layers 52 in the sensing units 20 on adjacent bridge arms 10 can be opposite, thereby making the magnetization directions of the reference layers 55 in the sensing units 20 on adjacent bridge arms 10 opposite; or, the pinning directions of the antiferromagnetic layers 52 in the sensing units 20 on adjacent bridge arms 10 can be perpendicular, thereby making the magnetization directions of the reference layers 55 in the sensing units 20 on adjacent bridge arms 10 perpendicular.

[0122] As one possible implementation method, such as Figure 1 , Figure 15 and Figure 16 As shown, in the full-bridge circuit structure, the major axes of the sensing units 20 on adjacent bridge arms 10 are parallel. A single current is applied to the current input terminal 70. The current flowing through the flip-flop functional layer 30 of the two diagonal bridge arms 10 flows in the same direction. The pinning direction of the antiferromagnetic layer 52 in the sensing unit 20 of the two diagonal bridge arms 10 is the same and opposite to the pinning direction of the sensing units 20 on the other two diagonal bridge arms 10. That is, the pinning direction of the antiferromagnetic layer 52 in the sensing unit 20 of the adjacent bridge arms 10 is opposite, thereby making the magnetization direction of the reference layer 55 in the sensing unit 20 of the adjacent bridge arms 10 opposite, realizing uniaxial magnetic field sensing.

[0123] As another possible implementation, in the full-bridge circuit structure, the long axis direction of each sensing unit 20 on adjacent bridge arms 10 is perpendicular. A single current is applied to the current input terminal 70, and the current flowing through the flip-flop functional layer 30 of the two diagonal bridge arms 10 has the same direction. The pinning direction of the antiferromagnetic layer 52 in the sensing unit 20 of the two diagonal bridge arms 10 is the same and perpendicular to the pinning direction of the sensing unit 20 on the other two diagonal bridge arms 10. That is, the pinning direction of the antiferromagnetic layer 52 in the sensing unit 20 of the adjacent bridge arms 10 is perpendicular, thereby making the magnetization direction of the reference layer 55 in the sensing unit 20 of the adjacent bridge arms 10 perpendicular, realizing dual-axis magnetic field sensing.

[0124] The heat generated by the flip-flop functional layer 30 is greater than the heat required for the antiferromagnetic layer 52 to reach its barrier temperature, but less than the heat required for the reference layer 55 to reach its Curie temperature. Because the heat generated by the flip-flop functional layer 30 is greater than the heat required for the antiferromagnetic layer 52 to reach its barrier temperature, the antiferromagnetic layer 52 loses its pinning effect. The antiferromagnetic layer 52 can respond to the local magnetic field generated by the current within the flip-flop functional layer 30 below it, causing its internal magnetic moments to rearrange according to the direction of the local magnetic field, thereby changing the pinning direction of the magnetic layer. As the heat dissipates and the temperature drops to the barrier temperature of the antiferromagnetic layer 52, the alignment of its internal magnetic moments tends to stabilize, and the new pinning direction is locked. The heat generated by the flip-flop functional layer 30 is less than the heat required for the reference layer 55 to reach its Curie temperature, which can prevent the reference layer 55 from losing its magnetism, thereby preventing device failure.

[0125] In some possible examples, such as Figure 15 and Figure 16 As shown, the flip-flop functional layers 30 of the sensing units 20 in the two diagonal bridge arms 10 are connected in series and sequentially. The flip-flop functional layer 30 of the sensing unit 20 in one of the two diagonal bridge arms 10 is connected to the current input terminal 70, and the flip-flop functional layer 30 of the sensing unit 20 in the other of the two diagonal bridge arms 10 is connected to the ground terminal 80. For example, the two diagonal bridge arms 10 share one flip-flop functional layer 30.

[0126] A single current is applied to the current input terminal 70. This current flows sequentially through the flip-flop functional layers 30 of the two diagonal bridge arms 10, and the current flows in the same direction. This makes the pinning direction of the antiferromagnetic layer 52 in the sensing unit 20 of the diagonal bridge arm 10 the same and opposite to the pinning direction of the antiferromagnetic layer 52 in the sensing unit 20 of the adjacent bridge arm 10. This makes the magnetization direction of the reference layer 55 in the sensing unit 20 of the adjacent bridge arm 10 opposite, and the magnetization direction of the reference layer 55 in the sensing unit 20 of the diagonal bridge arm 10 the same, thus realizing the full-bridge circuit structure.

[0127] See some possible examples. Figures 17 to 19 At least two full-bridge circuit structures have their flip-flop functional layers 30 connected in series in each diagonal bridge arm 10. By applying a single current to the current input terminal 70, the magnetization direction of the reference layer 55 on each diagonal bridge arm 10 is simultaneously changed. The sensing units 20 on each diagonal bridge arm 10 share the same flip-flop functional layer 30. This allows for the design of a shared flip-flop functional layer 30 across the entire wafer, enabling sensing units 20 with the same magnetization direction of the reference layer 55 to share the same flip-flop functional layer 30, thus reducing structural complexity.

[0128] In the full-bridge magnetoresistive sensor provided in this application embodiment, the long axes of the sensing units 20 on the opposite bridge arms 10 are parallel, and the current flowing through the flip-over functional layer 30 of the opposite bridge arms 10 flows in a parallel direction. The current in the flip-over functional layer 30 generates heat and triggers a local magnetic field, causing the pinning direction of the antiferromagnetic layer 52 of the sensing units 20 in the diagonal bridge arms 10 to flip, thereby changing the magnetization direction of the reference layer 55. This results in different magnetization directions of the reference layers 55 of adjacent bridge arms 10, thus realizing a complete full-bridge magnetoresistive sensor structure on the same chip. This eliminates the need for splicing, packaging, or complex magnetic structure designs of multiple individual sensing units 20, and avoids complex processes such as layout rotation or multiple magnetic field processing required when setting the magnetization direction of the reference layers 55 of different bridge arms 10. This simplifies the manufacturing process of the full-bridge magnetoresistive sensor structure and allows for selective changing of the magnetization direction of the reference layer 55 of a target bridge arm through current writing, supporting direction correction according to actual needs after manufacturing or during use. During the setting of the magnetization direction of the reference layer 55, the current does not flow directly through the magnetoresistive film 50, reducing damage to the magnetoresistive film 50 and improving the long-term reliability of the device. In addition, the magnetization direction of the reference layer 55 can be reset by applying a single current in the flip function layer 30, which is convenient for resetting; and by combining it with the setting of the long axis direction of the sensing unit 20, single-axis magnetic field detection or dual-axis magnetic field detection can be realized, improving the detection accuracy.

[0129] Thirdly, embodiments of this application also provide a full-bridge magnetoresistive sensor, see reference. Figures 20 to 23 The circuit structure of the full-bridge magnetoresistive sensor is a full-bridge circuit structure. The four bridge arms 10 of the full-bridge circuit structure are each composed of one or more sensing units 20 connected in series and parallel. The long axis directions of the sensing units 20 on adjacent bridge arms 10 are perpendicular. The sensing unit 20 includes: a flip-flop functional layer 30, a dielectric layer 40 and a magnetoresistive thin film 50 arranged from bottom to top. In the full-bridge circuit structure, the flip-flop functional layers 30 of the sensing units 20 on two parallel bridge arms 10 are connected to the same current input terminal 70, and the flip-flop functional layers 30 of the sensing units 20 on the other two parallel bridge arms 10 are connected to the same ground terminal 80. By applying a single current to the current input terminal 70, the current flowing through the flip-flop functional layers 30 of the adjacent bridge arms 10 is made perpendicular, so that the heat generated by the flip-flop functional layer 30 and the pinning direction of the antiferromagnetic layer 52 in the sensing unit 20 with local magnetic field flipping are perpendicular, thereby making the magnetization direction of the reference layer 55 in the sensing unit 20 of the adjacent bridge arms 10 perpendicular. The meaning, materials, and structure of the full-bridge circuit structure, sensing unit 20, and flip-flop functional layer 30 can be referred to the first aspect above, and will not be repeated here.

[0130] Among them, such as Figure 20As shown, the major axis of each sensing unit 20 on the four bridge arms 10 is a linear axis, that is, it extends along a straight line. The major axes of the sensing units 20 on adjacent bridge arms 10 are perpendicular. The major axis of the sensing unit 20 on one bridge arm 10 can be in the X direction, the major axis of the sensing unit 20 on another bridge arm 10 can be in the Y direction, and the major axes of the sensing units 20 on diagonal bridge arms 10 are parallel. Figure 21 , Figure 22 and Figure 23 As shown, the current flowing through the flip-up functional layer 30 of the adjacent bridge arm 10 is also perpendicular, and the sensing unit 20 of the adjacent bridge arm 10 can realize dual-axis magnetic field detection, reducing the complexity of a single sensing unit 20.

[0131] A single current is applied to the current input terminal 70. The current flowing through the flip-flop functional layer 30 of the adjacent bridge arm 10 flows vertically. The flip-flop functional layer 30 generates heat and a local magnetic field. The thermo-magnetic coupling mechanism causes the pinning direction of the antiferromagnetic layer 52 of the sensing unit 20 to be flipped, thereby making the pinning direction of the antiferromagnetic layer 52 in the sensing unit 20 of the adjacent bridge arm 10 vertical. This, in turn, makes the magnetization direction of the reference layer 55 in the sensing unit 20 of the adjacent bridge arm 10 vertical.

[0132] In this configuration, the sensing units 20 of each bridge arm 10 have independent flip-flop functional layers 30, with each sensing unit 20 of each bridge arm 10 connected to a corresponding flip-flop functional layer 30. Alternatively, the sensing units 20 of two series-connected bridge arms 10 have their flip-flop functional layers 30 connected sequentially, with one bridge arm 10's sensing unit 20 flip-flop functional layer 30 connected to the current input terminal 70, and the other bridge arm 10's sensing unit 20 flip-flop functional layer 30 connected to the ground terminal 80. Or, the sensing units 20 of two series-connected bridge arms 10 have their flip-flop functional layers 30 connected sequentially, with one bridge arm 10's sensing unit 20 flip-flop functional layer 30 connected to the current input terminal 70, and the other bridge arm 10's sensing unit 20 flip-flop functional layer 30 connected to the ground terminal 80. The sensing units 20 of the other two series-connected bridge arms 10 are each connected to a corresponding flip-flop functional layer 30.

[0133] In the full-bridge magnetoresistive sensor provided in this application embodiment, the long axis of the sensing unit 20 on adjacent bridge arms 10 is perpendicular, and the current flowing through the flip-over functional layer 30 of the adjacent bridge arms 10 flows perpendicularly, enabling biaxial magnetic field detection and improving detection accuracy. By utilizing the current generated by the flip-over functional layer 30 to generate heat and trigger a local magnetic field, the pinning direction of the antiferromagnetic layer 52 of the sensing unit 20 in adjacent bridge arms 10 is flipped. This allows for the realization of a complete full-bridge magnetoresistive sensor structure on a single chip, eliminating the need for splicing, packaging, or complex magnetic structure designs of multiple individual sensing units 20. It also avoids the complex processes of layout rotation or multiple magnetic field processing required when setting the magnetization direction of the reference layer 55 of different bridge arms 10, simplifying the manufacturing process of the full-bridge magnetoresistive sensor structure. Furthermore, it allows for selective changing of the magnetization direction of the reference layer 55 of the target bridge arm through current writing, supporting direction correction according to actual needs after manufacturing or during use. During the magnetization orientation setting process of the reference layer 55, the current does not directly act on the magnetoresistive film 50, reducing damage to the magnetoresistive film 50 and improving the long-term reliability of the device. Furthermore, the magnetization orientation of the reference layer 55 can be reset by applying a single current in the flip function layer 30, making resetting convenient.

[0134] Finally, it should be noted that other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein, and is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A full-bridge magnetoresistive sensor, characterized in that, The circuit structure of the full-bridge magnetoresistive sensor is a full-bridge circuit structure. The four arms of the full-bridge circuit structure are each composed of one or more sensing units connected in series and parallel. The major axis directions of the sensing units on adjacent arms of the full-bridge circuit structure are parallel. The sensing unit includes, from bottom to top, a flip-out functional layer, a dielectric layer, and a magnetoresistive thin film; In the full-bridge circuit structure, the flip-flop functional layers of the sensing units on the two parallel bridge arms are connected to the same current input terminal, and the flip-flop functional layers of the sensing units on the other two parallel bridge arms are connected to the same ground terminal. By applying a single current to the current input terminal, the current flowing through the flip-over functional layer of the adjacent bridge arm flows in opposite directions, so that the heat generated by the flip-over functional layer and the pinning direction of the antiferromagnetic layer in the sensing unit of the local magnetic field flip are opposite, thereby making the magnetization direction of the reference layer in the sensing unit of the adjacent bridge arm opposite.

2. The full-bridge magnetoresistive sensor according to claim 1, characterized in that, The sensing unit consists of two sub-sensing units whose major axes are perpendicular to each other; The ends of the flip-flop functional layers corresponding to the two sub-sensing units are connected and perpendicular to each other.

3. The full-bridge magnetoresistive sensor according to claim 1, characterized in that, The flip-over functional layers of the sensing units on the two series bridge arms are connected in series with each other; or, The flip-over functional layers of the sensing units on the two diagonal bridge arms are connected in series with each other. When the number of full-bridge circuit structures is at least two, the flip-over functional layers of each diagonal bridge arm of the at least two full-bridge circuit structures are connected in series with each other.

4. A full-bridge magnetoresistive sensor, characterized in that, The circuit structure of the full-bridge magnetoresistive sensor is a full-bridge circuit structure. The four arms of the full-bridge circuit structure are each composed of one or more sensing units connected in series and parallel. The major axis directions of the sensing units on adjacent arms of the full-bridge circuit structure are parallel. The sensing unit includes, from bottom to top, a flip-out functional layer, a dielectric layer, and a magnetoresistive thin film; In the full-bridge circuit structure, the flip-flop functional layers of the sensing units on the two diagonal bridge arms are connected to the same current input terminal and the same ground terminal. By applying a single current to the current input terminal, the current flowing through the flip-over functional layer of the diagonal bridge arm is made to flow in the same direction, so that the heat generated by the flip-over functional layer and the pinning direction of the antiferromagnetic layer in the sensing unit of the local magnetic field flip are the same, thereby making the magnetization direction of the reference layer in the sensing unit of the adjacent bridge arm different.

5. The full-bridge magnetoresistive sensor according to claim 4, characterized in that, The number of full-bridge circuit structures is at least two, and the flip-over functional layers of each diagonal bridge arm of the at least two full-bridge circuit structures are connected in series to change the magnetization direction of the reference layer on each diagonal bridge arm by applying a single current to the current input terminal. The sensing units on each of the diagonal arms share the same flip function layer.

6. A full-bridge magnetoresistive sensor, characterized in that, The circuit structure of the full-bridge magnetoresistive sensor is a full-bridge circuit structure. The four arms of the full-bridge circuit structure are each composed of one or more sensing units connected in series and parallel. The major axis directions of the sensing units on adjacent arms of the full-bridge circuit structure are perpendicular. The sensing unit includes, from bottom to top, a flip-out functional layer, a dielectric layer, and a magnetoresistive thin film; In the full-bridge circuit structure, the flip-flop functional layers of the sensing units on the two parallel bridge arms are connected to the same current input terminal, and the flip-flop functional layers of the sensing units on the other two parallel bridge arms are connected to the same ground terminal. By applying a single current to the current input terminal, the current flowing through the flip-over functional layer of the adjacent bridge arm is made perpendicular, so that the heat generated by the flip-over functional layer and the pinning direction of the antiferromagnetic layer in the sensing unit where the local magnetic field is flipped are perpendicular, thereby making the magnetization direction of the reference layer in the sensing unit on the adjacent bridge arm perpendicular.

7. The full-bridge magnetoresistive sensor according to any one of claims 1 to 6, characterized in that, The heat generated by the flip-over functional layer is greater than the heat required for the antiferromagnetic layer to rise to its barrier temperature, but less than the heat required for the reference layer to rise to its Curie temperature. And / or, the material of the flip-functional layer includes tantalum nitride, bismuth telluride, and bismuth selenide.

8. The full-bridge magnetoresistive sensor according to any one of claims 1 to 6, characterized in that, The magnetoresistive thin film includes an antiferromagnetic layer, a reference layer, a barrier layer, and a free layer arranged sequentially along the direction away from the flip-functional layer. The magnetization direction of the free layer is perpendicular to the magnetization direction of the reference layer.

9. The full-bridge magnetoresistive sensor according to any one of claims 1 to 6, characterized in that, The magnetoresistive thin film is composed of several sub-magnetoresistive thin films connected in series.

10. An electronic device, characterized in that, Including the full-bridge magnetoresistive sensor as described in any one of claims 1 to 9.

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