Tri-axial magnetic sensor and method of manufacturing the same

Abstract

A tri-axial magnetic sensor and a method for manufacturing the same. The tri-axial magnetic sensor comprises a substrate, two first giant magnetoresistance sensor elements, two second giant magnetoresistance sensor elements and a Hall sensor element. The Hall sensor element is located on a central region of the substrate. The two first giant magnetoresistance sensor elements are respectively located on opposite sides of the Hall sensor element. The two second giant magnetoresistance sensor elements are respectively located on the other opposite sides of the Hall sensor element. The magnetic moment of a first pinned layer of the first giant magnetoresistance sensor element is fixed in a first direction. The magnetic moment of a second pinned layer of the second giant magnetoresistance sensor element is fixed in a second direction. The tri-axial magnetic sensor integrates the giant magnetoresistance sensor and the Hall sensor on the same substrate, and realizes tri-axial magnetic field detection in a planar structure.

Description

Technical Field

[0001] This invention relates to the field of magnetic sensors, specifically to a triaxial magnetic sensor and its fabrication method. Background Technology

[0002] Magnetic sensors are widely used in consumer electronics, automotive electronics, industrial control, and aerospace. Triaxial magnetic sensors can simultaneously capture magnetic field information in three orthogonal directions (X, Y, and Z) in space, overcoming the directional blind spots of single-axis and dual-axis sensors. They enable full-dimensional magnetic field sensing and are a key foundation for modern equipment to achieve three-dimensional spatial perception and move towards intelligence and precision. Currently, the technical solutions for achieving triaxial magnetic field detection include the following two categories: The first approach uses 3D packaging technology to vertically package multiple uniaxial tunnel magnetoresistive (TMR) magnetic sensors in pairs, enabling magnetic field detection along the X, Y, and Z axes in space. However, this approach requires a complex 3D packaging structure; the Z-axis TMR magnetic sensor is vertically placed, making chip flattening impossible, and the packaging cost is also high.

[0003] The second approach involves fabricating a single-axis sensor on an inclined plane, enabling the sensor to respond to magnetic fields in multiple directions. The magnetic field strength components along the X, Y, and Z axes are then calculated using algorithms. However, this approach involves complex fabrication processes, and the magnetic field signals from different directions are prone to coupling, requiring sophisticated signal decoupling circuits to handle this, thus increasing the system design complexity. Summary of the Invention

[0004] The technical problem solved by the present invention is to provide a triaxial magnetic sensor and its fabrication method, which realizes triaxial magnetic field detection in a planar structure by integrating a giant magnetoresistive sensor and a Hall sensor on the same substrate.

[0005] To solve the above-mentioned technical problems, the present invention provides a triaxial magnetic sensor comprising: a substrate; two first giant magnetoresistive (GMR) sensor elements located on the substrate, each first GMR sensor element comprising, from bottom to top, a first antiferromagnetic layer, a first pinning layer, and a plurality of first fin structures arranged in an array, wherein the magnetic moment of the first pinning layer is fixed along a first direction, and the plurality of first fin structures are arranged along the first direction, the first direction being parallel to the surface of the substrate; two second GMR sensor elements located on the substrate, each second GMR sensor element comprising, from bottom to top, a second antiferromagnetic layer, a second pinning layer, and a plurality of second fin structures arranged in an array, wherein the magnetic moment of the second pinning layer is fixed along a second direction, and the plurality of second fin structures are arranged along the second direction, the second direction being parallel to the surface of the substrate and perpendicular to the first direction; and a Hall sensor element located in the central region of the substrate, wherein the two first GMR sensor elements are respectively located on opposite sides of the Hall sensor element, and the two second GMR sensor elements are respectively located on the other opposite sides of the Hall sensor element.

[0006] Optionally, the length-to-width ratio of the first fin structure is greater than 10:1, and the length-to-width ratio of the second fin structure is greater than 10:1.

[0007] Optionally, the first fin structure includes a first non-magnetic metal layer and a first free layer stacked sequentially from bottom to top.

[0008] Optionally, the second fin structure includes a second non-magnetic metal layer and a second free layer stacked sequentially from bottom to top.

[0009] Optionally, the material of the first antiferromagnetic layer includes at least one of PtMn, NiMn, CrPt, and PdMn; the material of the second antiferromagnetic layer includes at least one of IrMn, FeMn, and RuMn.

[0010] Optionally, an insulating layer is also provided between the Hall sensor element and the substrate.

[0011] Accordingly, the technical solution of the present invention also provides a method for fabricating a triaxial magnetic sensor, comprising: providing a substrate; forming two first giant magnetoresistive sensor elements on the substrate, the first giant magnetoresistive sensor elements comprising a first antiferromagnetic layer, a first pinning layer, and a plurality of first fin structures arranged in an array, stacked sequentially from bottom to top, the magnetic moment of the first pinning layer being fixed along a first direction, the plurality of first fin structures being arranged along the first direction, the first direction being parallel to the surface of the substrate; forming two second giant magnetoresistive sensor elements on the substrate, the second giant magnetoresistive sensor elements comprising a second antiferromagnetic layer, a second pinning layer, and a plurality of second fin structures arranged in an array, stacked sequentially from bottom to top, the magnetic moment of the second pinning layer being fixed along a second direction, the plurality of second fin structures being arranged along the second direction, the second direction being parallel to the surface of the substrate and perpendicular to the first direction; forming a Hall sensor element in the central region of the substrate, the two first giant magnetoresistive sensor elements being located on opposite sides of the Hall sensor element, and the two second giant magnetoresistive sensor elements being located on the other opposite sides of the Hall sensor element.

[0012] Optionally, the method of forming the Hall sensor element includes: forming a Hall sensor functional film on the substrate; forming a first electrode pair and a second electrode pair on the surface of the Hall sensor functional film, wherein the first electrode pair is symmetrically distributed along a first direction with respect to the center of the Hall sensor functional film, and the second electrode pair is symmetrically distributed along a second direction with respect to the center of the Hall sensor functional film.

[0013] Optionally, the method of forming the plurality of first fin structures includes: forming a first non-magnetic metal layer and a first free layer stacked sequentially on the surface of the first pinned layer; forming a plurality of first grooves in the first non-magnetic metal layer and the first free layer, wherein the bottom of the first groove exposes the first pinned layer, so as to form the plurality of first fin structures.

[0014] Optionally, the method of forming the plurality of second fin structures includes: forming a second non-magnetic metal layer and a second free layer stacked sequentially on the surface of the second pinning layer; forming a plurality of second grooves in the second non-magnetic metal layer and the second free layer, wherein the bottom of the second grooves exposes the second pinning layer, so as to form the plurality of second fin structures.

[0015] Compared with the prior art, the technical solution of the present invention has the following beneficial effects: The triaxial magnetic sensor provided by this invention integrates the first giant magnetoresistive (GMMR) sensor elements, the second giant magnetoresistive (GMMR) sensor elements, and the Hall sensor element onto a substrate, thus achieving chip flattening. Since the first GMMR sensor element comprises a first antiferromagnetic layer and a first pinning layer stacked sequentially from bottom to top, and the magnetic moment of the first pinning layer is fixed along a first direction parallel to the substrate surface, the exchange bias effect between the first antiferromagnetic layer and the first pinning layer fixes the magnetic moment of the first pinning layer in the first direction, i.e., the X-axis direction. Furthermore, since several first fin-shaped structures arranged in an array are arranged along the first direction, the easy magnetization axis of the first GMMR sensor element is perpendicular to the magnetic moment direction of the first pinning layer. Therefore, the first GMMR sensor element exhibits high sensitivity to in-plane magnetic fields in the Y-axis direction. Similarly, by utilizing the exchange bias effect between the second antiferromagnetic layer and the second pinning layer, the magnetic moment of the second pinning layer is fixed in the second direction, i.e., the Y-axis direction. The easy magnetization axis of the second giant magnetoresistive sensor element is perpendicular to the direction of the magnetic moment of the second pinning layer. Therefore, the second giant magnetoresistive sensor element has a high sensitivity response to in-plane magnetic fields in the X-axis direction. Furthermore, since the Hall sensor element is located in the central region of the substrate for detecting out-of-plane Z-axis magnetic fields, and the two first giant magnetoresistive sensor elements are located on opposite sides of the Hall sensor element, and the two second giant magnetoresistive sensor elements are located on the other opposite sides of the Hall sensor, this invention integrates the first and second giant magnetoresistive sensor elements surrounding the Hall sensor element on the same substrate, enabling magnetic field detection along the Z, X, and Y axes respectively. This achieves triaxial magnetic field detection within a planar structure, avoids magnetic signal crosstalk, and realizes chip flattening.

[0016] The method for preparing the triaxial magnetic sensor provided by the technical solution of the present invention is used to prepare the above-mentioned triaxial magnetic sensor, and therefore also has the above-mentioned technical effects, which will not be repeated here. Attached Figure Description

[0017] Figures 1 to 8 This is a schematic diagram of the structure of each step in the fabrication method of the triaxial magnetic sensor according to an embodiment of the present invention.

[0018] Explanation of reference numerals in the attached figures: 100, Substrate; 210, First antiferromagnetic layer; 220, First pinning layer; 230, First fin structure; 310, Second antiferromagnetic layer; 320, Second pinning layer; 330, Second fin structure; 400, Hall sensor functional thin film; 410, First electrode; 420, Second electrode; Mx, First direction; My, Second direction. Detailed Implementation

[0019] As mentioned in the background section, achieving triaxial magnetic field detection within a planar structure is a technical problem that needs to be solved.

[0020] To solve the above-mentioned technical problems, the present invention provides a triaxial magnetic sensor and its fabrication method, which realizes triaxial magnetic field detection in a planar structure by integrating a giant magnetoresistive sensor and a Hall sensor on the same substrate.

[0021] To make the above-mentioned objectives, features, and beneficial effects of the present invention more apparent and understandable, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification, claims, and drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a particular order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus. Additionally, directional terms such as above, below, up, down, upward, downward, left, right, etc., are used relative to exemplary embodiments as they are shown in the figures, with upward or upper directions pointing towards the top of the corresponding figure and downward or lower directions pointing towards the bottom of the corresponding figure.

[0023] Figures 1 to 8 This is a schematic diagram of the structure of each step in the fabrication method of the triaxial magnetic sensor according to an embodiment of the present invention.

[0024] Please refer to Figure 1 Substrate 100 is provided.

[0025] In this embodiment, the material of the substrate 100 may include Si. The size of the substrate 100 may be 6 inches, 8 inches, 12 inches, etc., and there is no limitation thereto.

[0026] Please refer to the reference. Figures 2 to 6 Two first giant magnetoresistive sensor elements are formed on the substrate 100; two second giant magnetoresistive magnetic sensor elements are formed on the substrate 100.

[0027] In this embodiment, the first giant magnetoresistive sensor element includes a first antiferromagnetic layer 210, a first pinning layer 220, and a plurality of first fin structures 230 arranged in an array, stacked sequentially from bottom to top.

[0028] In this embodiment, the second giant magnetoresistive sensor element includes a second antiferromagnetic layer 310, a second pinning layer 320, and a plurality of second fin structures 330 arranged in an array, stacked sequentially from bottom to top.

[0029] Please continue to refer to this. Figure 2 A first antiferromagnetic layer 210 is formed on the surface of the substrate 100.

[0030] In this embodiment, the first antiferromagnetic layer 210 is located on opposite sides of the substrate 100.

[0031] Specifically, the process of forming the first antiferromagnetic layer 210 may include an annealing process, wherein the annealing temperature of the first antiferromagnetic layer 210 is greater than the annealing temperature of the second antiferromagnetic layer 310, and the annealing temperature of the first antiferromagnetic layer 210 is higher than 300°C.

[0032] Specifically, the material of the first antiferromagnetic layer 210 may include at least one of PtMn, NiMn, CrPt and PdMn.

[0033] Please refer to Figure 3 A first pinning layer 220 is formed on the surface of the first antiferromagnetic layer 210.

[0034] In this embodiment, the magnetic moment of the first pinning layer 220 is fixed along the first direction Mx.

[0035] Specifically, the first direction Mx is parallel to the surface of the substrate 100.

[0036] Specifically, the material of the first pinning layer 220 may include an iron-nickel alloy.

[0037] Specifically, the method for fixing the magnetic moment of the first pinning layer 220 along the first direction Mx may include: applying an external magnetic field during annealing at 500°C, and fixing the direction of the magnetic moment of the first pinning layer 220 by the exchange biasing effect of the first antiferromagnetic layer 210.

[0038] Please refer to Figure 4 A second antiferromagnetic layer 310 is formed on the surface of the substrate 100.

[0039] In this embodiment, the second antiferromagnetic layer 310 is located on the other opposite sides of the substrate 100.

[0040] Specifically, the process of forming the second antiferromagnetic layer 310 may include an annealing process, wherein the annealing temperature of the second antiferromagnetic layer 310 is below 300°C.

[0041] Specifically, the material of the second antiferromagnetic layer 310 may include at least one of IrMn, FeMn and RuMn.

[0042] Please refer to Figure 5 A second pinning layer 320 is formed on the surface of the second antiferromagnetic layer 310.

[0043] In this embodiment, the magnetic moment of the second pinning layer 320 is fixed along the second direction My.

[0044] Specifically, the second direction My is parallel to the surface of the substrate 100 and perpendicular to the first direction Mx.

[0045] Specifically, the material of the second pinning layer 320 may include an iron-nickel alloy.

[0046] Specifically, the method for fixing the magnetic moment of the second pinning layer 320 along the second direction My may include: applying an external magnetic field during annealing at 200°C, and fixing the direction of the magnetic moment of the second pinning layer 320 by the exchange biasing effect of the second antiferromagnetic layer 310.

[0047] Please refer to Figure 6 A plurality of first fin structures 230 arranged in an array are formed on the first pinning layer 220, and a plurality of second fin structures 330 arranged in an array are formed on the second pinning layer 320.

[0048] Specifically, several first fin-shaped structures 230 are arranged along the first direction Mx.

[0049] Specifically, several second fin-shaped structures 330 are arranged along the second direction My.

[0050] Specifically, the length-to-width ratio of the first fin structure 230 is greater than 10:1, and the length-to-width ratio of the second fin structure 330 is greater than 10:1.

[0051] Specifically, the length of the first fin structure 230 refers to the dimension parallel to the second direction My, the width of the first fin structure 230 refers to the dimension parallel to the first direction Mx, the length of the second fin structure 330 refers to the dimension parallel to the first direction Mx, and the width of the second fin structure 330 refers to the dimension parallel to the second direction My.

[0052] In this embodiment, the method of forming a plurality of first fin structures 230 may include: forming a first non-magnetic metal layer and a first free layer stacked sequentially on the surface of the first pinning layer 220; forming a plurality of first grooves in the first non-magnetic metal layer and the first free layer, wherein the bottom of the first groove exposes the first pinning layer 220, so as to form a plurality of first fin structures 230.

[0053] In this embodiment, the method of forming a plurality of second fin structures 330 may include: forming a second non-magnetic metal layer and a second free layer stacked in sequence on the surface of the second pinning layer 320; forming a plurality of second grooves in the second non-magnetic metal layer and the second free layer, the bottoms of the second grooves exposing the second pinning layer 320, so as to form the plurality of second fin structures 330.

[0054] In this embodiment, the first grooves penetrate through the first free layer and extend into the first non-magnetic metal layer, the plurality of first fin structures 230 are composed of the first free layer and the first non-magnetic metal layer, the second grooves penetrate through the second free layer and extend into the second non-magnetic metal layer, and the plurality of second fin structures 330 are composed of the second free layer and the second non-magnetic metal layer.

[0055] In this embodiment, the exchange bias effect is used to respectively fix the magnetic moment directions of the pinning layers of the two giant magnetoresistive sensor elements located on the four sides of the substrate 100, and at the same time, a shape anisotropy easy magnetization axis is formed through the plurality of first fin structures 230 and the plurality of second fin structures 330, so that the first giant magnetoresistive sensor element and the second giant magnetoresistive sensor element are sensitive to the magnetic fields in the Y-axis and X-axis directions respectively, thereby realizing the decoupling of the magnetic field signals in the X-axis and Y-axis directions at multiple levels including the physical mechanism, the easy magnetization axis direction and the structural layout.

[0056] Please refer to Figure 7 and Figure 8 , a Hall sensor element is formed on the central region of the substrate 100.

[0057] In this embodiment, the two first giant magnetoresistive sensor elements are respectively located on two opposite sides of the Hall sensor element, and the two second giant magnetoresistive sensor elements are respectively located on the other two opposite sides of the Hall sensor element.

[0058] Specifically, both the two first giant magnetoresistive sensor elements and the two second giant magnetoresistive sensor elements have a rectangular structure. The four giant magnetoresistive sensor elements are arranged in a centrally symmetric edge-adjacent layout with the Hall sensor element as the center, and the four giant magnetoresistive sensor elements are arranged in a "loop" shape or a frame shape on the horizontal plane. The long sides and short sides of the four giant magnetoresistive sensor elements are respectively attached to each other to form a closed rectangular outer frame, and the inner boundary of the rectangular outer frame encloses a square central area, in which the Hall sensor element is exactly filled and located. Preferably, the inner edges of the four giant magnetoresistive sensor elements are in contact with each other or keep a very small gap, so as to ensure that the boundary of the central square space is clear and regular.

[0059] In this embodiment, the Hall sensor element includes a Hall sensor functional thin film 400, a first electrode 410, and a second electrode 420.

[0060] In this embodiment, the method of forming a Hall sensor element may include: forming a Hall sensor functional film 400 on a central region of a substrate 100; after forming the Hall sensor functional film 400, the method further includes forming a first electrode pair 410 and a second electrode pair 420 on the surface of the Hall sensor functional film 400, wherein the first electrode pair 410 is symmetrically distributed along a first direction Mx with respect to the center of the Hall sensor functional film 400, and the second electrode pair 420 is symmetrically distributed along a second direction Mx with respect to the center of the Hall sensor functional film 400, and both the first electrode pair 410 and the second electrode pair 420 are parallel to the surface of the substrate 100 for measuring the magnetic field in the Z-axis direction.

[0061] Specifically, the Hall sensor functional thin film 400 can be rectangular.

[0062] Specifically, the material of the Hall sensor functional thin film 400 may include InSb.

[0063] Specifically, the materials of the first electrode pair 410 and the second electrode pair 420 may both include Au.

[0064] In this embodiment, before forming the Hall sensor element, an insulating layer is formed on the surface of the central region of the substrate 100, and the insulating layer is located between the Hall sensor element and the substrate 100.

[0065] Specifically, the material of the insulating layer can include SiO2.

[0066] In this embodiment, since the two first giant magnetoresistive (GMMR) sensor elements, the two second GMMR sensor elements, and the Hall sensor element are all located on the substrate 100, the first GMMR sensor elements, the second GMMR sensor elements, and the Hall element are integrated on the same plane, achieving chip flattening. Because the first GMMR sensor element includes a first antiferromagnetic layer 210 and a first pinning layer 220 stacked sequentially from bottom to top, and the magnetic moment of the first pinning layer 220 is fixed along a first direction parallel to the surface of the substrate 100, the magnetic moment of the first pinning layer 220 is fixed in the first direction, i.e., the X-axis direction, by utilizing the exchange bias effect between the first antiferromagnetic layer 210 and the first pinning layer 220. Furthermore, because the array of several first fin structures 230 is arranged along the first direction, the easy magnetization axis of the first GMMR sensor element is perpendicular to the magnetic moment direction of the first pinning layer 220. Therefore, the first GMMR sensor element has a high sensitivity response to in-plane magnetic fields in the Y-axis direction. Similarly, by utilizing the exchange bias effect between the second antiferromagnetic layer 310 and the second pinning layer 320, the magnetic moment of the second pinning layer 320 is fixed in the second direction, i.e., the Y-axis direction. The easy magnetization axis of the second giant magnetoresistive sensor element is perpendicular to the direction of the magnetic moment of the second pinning layer 320. Therefore, the second giant magnetoresistive sensor element has a high sensitivity response to in-plane magnetic fields in the X-axis direction. Furthermore, since the Hall sensor element is located in the central region of the substrate 100 for detecting out-of-plane Z-axis magnetic fields, and the two first giant magnetoresistive sensor elements are located on opposite sides of the Hall sensor element, and the two second giant magnetoresistive sensor elements are located on the other opposite sides of the Hall sensor, this invention integrates the first and second giant magnetoresistive sensor elements surrounding the Hall sensor element on the same substrate 100, respectively performing magnetic field detection along the Z, Y, and X axes. This achieves triaxial magnetic field detection within a planar structure, avoids magnetic signal crosstalk, and realizes chip flattening.

[0067] Accordingly, this embodiment of the invention also provides a triaxial magnetic sensor prepared by the above-described method for preparing a triaxial magnetic sensor, comprising: a substrate 100, two first giant magnetoresistive sensor elements, two second giant magnetoresistive sensor elements, and a Hall sensor element.

[0068] Specifically, two first giant magnetoresistive sensor elements are located on the substrate 100. The first giant magnetoresistive sensor elements include a first antiferromagnetic layer 210, a first pinning layer 220, and a plurality of first fin structures 230 arranged in an array, which are stacked sequentially from bottom to top. The magnetic moment of the first pinning layer 220 is fixed along a first direction, and the plurality of first fin structures 230 are arranged along a first direction, which is parallel to the surface of the substrate 100.

[0069] Specifically, two second giant magnetoresistive sensor elements are located on the substrate 100. The second giant magnetoresistive sensor elements include a second antiferromagnetic layer 310, a second pinning layer 320, and a plurality of second fin structures 330 arranged in an array, which are stacked sequentially from bottom to top. The magnetic moment of the second pinning layer 320 is fixed along a second direction, and the plurality of second fin structures 330 are arranged along a second direction, which is parallel to the surface of the substrate 100 and perpendicular to the first direction.

[0070] Specifically, the Hall sensor element is located in the central region of the substrate 100, two first giant magnetoresistive sensor elements are located on opposite sides of the Hall sensor element, and two second giant magnetoresistive sensor elements are located on the other opposite sides of the Hall sensor element.

[0071] The materials, forming process, working principle, specific implementation method and beneficial effects of the triaxial magnetic sensor in the embodiments of the present invention can be found in the preparation method of the triaxial magnetic sensor in the embodiments of the present invention, and will not be repeated here.

[0072] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A triaxial magnetic sensor, characterized in that, include: Substrate; Two first giant magnetoresistive sensor elements are located on the substrate. Each first giant magnetoresistive sensor element includes a first antiferromagnetic layer, a first pinning layer, and a plurality of first fin structures arranged in an array, which are stacked sequentially from bottom to top. The magnetic moment of the first pinning layer is fixed along a first direction, and the plurality of first fin structures are arranged along the first direction, which is parallel to the surface of the substrate. Two second giant magnetoresistive sensor elements are located on the substrate. Each second giant magnetoresistive sensor element includes a second antiferromagnetic layer, a second pinning layer, and a plurality of second fin structures arranged in an array, which are stacked sequentially from bottom to top. The magnetic moment of the second pinning layer is fixed along a second direction. The plurality of second fin structures are arranged along the second direction, which is parallel to the surface of the substrate and perpendicular to the first direction. A Hall sensor element is located on the central region of the substrate, two first giant magnetoresistive sensor elements are located on opposite sides of the Hall sensor element, and two second giant magnetoresistive sensor elements are located on the other opposite sides of the Hall sensor element.

2. The triaxial magnetic sensor as described in claim 1, characterized in that, The length-to-width ratio of the first fin structure is greater than 10:1, and the length-to-width ratio of the second fin structure is greater than 10:

1.

3. The triaxial magnetic sensor as described in claim 2, characterized in that, The first fin structure includes a first non-magnetic metal layer and a first free layer stacked from bottom to top.

4. The triaxial magnetic sensor as described in claim 2, characterized in that, The second fin structure includes a second non-magnetic metal layer and a second free layer stacked sequentially from bottom to top.

5. The triaxial magnetic sensor as described in claim 1, characterized in that, The material of the first antiferromagnetic layer includes at least one of PtMn, NiMn, CrPt, and PdMn; the material of the second antiferromagnetic layer includes at least one of IrMn, FeMn, and RuMn.

6. The triaxial magnetic sensor as described in claim 1, characterized in that, An insulating layer is also present between the Hall sensor element and the substrate.

7. A method for fabricating a triaxial magnetic sensor, characterized in that, include: Provide substrate; Two first giant magnetoresistive sensor elements are formed on the substrate. Each first giant magnetoresistive sensor element includes a first antiferromagnetic layer, a first pinning layer, and a plurality of first fin structures arranged in an array, which are stacked sequentially from bottom to top. The magnetic moment of the first pinning layer is fixed along a first direction, and the plurality of first fin structures are arranged along the first direction, which is parallel to the surface of the substrate. Two second giant magnetoresistive sensor elements are formed on the substrate. The second giant magnetoresistive sensor elements include a second antiferromagnetic layer, a second pinning layer, and a plurality of second fin structures arranged in an array, which are stacked sequentially from bottom to top. The magnetic moment of the second pinning layer is fixed along a second direction. The plurality of second fin structures are arranged along the second direction, which is parallel to the surface of the substrate and perpendicular to the first direction. A Hall sensor element is formed on the central region of the substrate, with two first giant magnetoresistive sensor elements located on opposite sides of the Hall sensor element, and two second giant magnetoresistive sensor elements located on the other opposite sides of the Hall sensor element.

8. The preparation method according to claim 7, characterized in that, The method of forming the Hall sensor element includes: A Hall sensor functional thin film is formed on the substrate; A first electrode pair and a second electrode pair are formed on the surface of the Hall sensor functional film. The first electrode pair is symmetrically distributed along a first direction with respect to the center of the Hall sensor functional film, and the second electrode pair is symmetrically distributed along a second direction with respect to the center of the Hall sensor functional film.

9. The preparation method according to claim 8, characterized in that, The method of forming the plurality of first fin structures includes: forming a first non-magnetic metal layer and a first free layer stacked sequentially on the surface of the first pinned layer; forming a plurality of first grooves in the first non-magnetic metal layer and the first free layer, wherein the bottom of the first groove exposes the first pinned layer, so as to form the plurality of first fin structures.

10. The preparation method according to claim 8, characterized in that, The method of forming the plurality of second fin structures includes: forming a second non-magnetic metal layer and a second free layer stacked sequentially on the surface of the second pinning layer; forming a plurality of second grooves in the second non-magnetic metal layer and the second free layer, wherein the bottom of the second grooves exposes the second pinning layer, so as to form the plurality of second fin structures.

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