Three-axis magnetic sensor

Abstract

The present application relates to a three-axis magnetic sensor, comprising: a substrate in which a magnetic field steering member is built, the magnetic field steering member being inclined between a third direction and a first direction / second direction for steering a magnetic field in the third direction so that the magnetic field has a magnetic field component in the first direction / second direction; the first magnetic field sensitive area, the second magnetic field sensitive area and the third magnetic field sensitive area are arranged on the plane of the substrate and are respectively formed by connecting magnetic tunnel junctions in series, in parallel or in a mode of combining series connection and parallel connection; the magnetic tunnel junction located in the first magnetic field sensitive area has a pinning direction along a first direction, and the magnetic tunnel junction located in the second magnetic field sensitive area has a pinning direction along a second direction; the third magnetic field sensitive area is arranged at the position, corresponding to the magnetic field steering piece, on the plane of the substrate, and the magnetic tunnel junction located in the third magnetic field sensitive area has the pinning direction in the first direction / the second direction. The preparation process is simplified, and the preparation yield is improved.

Description

Technical Field

[0001] The present application relates to the technical field of magnetic field sensing devices, and in particular to a three-axis magnetic sensor. Background Art

[0002] With the development of science and technology and the continuous progress of society, more and more types of magnetic sensors are appearing in people's daily work and life. TMR (Tunnel Magnetoresistance Effect) magnetic sensor is a magnetic sensitive element that uses the tunnel magnetoresistance effect. The external magnetic field can cause the resistance change of the TMR magnetoresistance element to detect the external magnetic field. However, the TMR magnetoresistance element can only sense the magnetic field in the plane.

[0003] In order to enable the TMR magnetoresistive element to detect out-of-plane magnetic fields, traditional magnetic sensors usually need to deposit a TMR magnetic film on a slope and then etch the TMR magnetic film on the slope to form a magnetic tunnel junction. The deposition and etching of the TMR magnetic film on the slope is a complex process and has the disadvantage of low preparation yield. Utility Model Content

[0004] In view of the above problems, it is necessary to provide a three-axis magnetic sensor that can improve the manufacturing yield.

[0005] A three-axis magnetic sensor, comprising:

[0006] A substrate, wherein the substrate has a magnetic field steering member built therein, wherein the magnetic field steering member is inclined between the third direction and the first direction / the second direction, and is used to redirect the magnetic field in the third direction so that it has a magnetic field component in the first direction / the second direction;

[0007] A first magnetic field sensitive area, a second magnetic field sensitive area and a third magnetic field sensitive area are arranged on the plane of the substrate, wherein the first magnetic field sensitive area, the second magnetic field sensitive area and the third magnetic field sensitive area are all composed of magnetic tunnel junctions connected in series, in parallel or in combination of series and parallel; the magnetic tunnel junction located in the first magnetic field sensitive area has a pinning direction along the first direction, and the magnetic tunnel junction located in the second magnetic field sensitive area has a pinning direction along the second direction; the third magnetic field sensitive area is arranged at a position corresponding to the magnetic field steering element on the plane of the substrate, and the magnetic tunnel junction located in the third magnetic field sensitive area has a pinning direction along the first direction / the second direction;

[0008] The first direction, the second direction and the third direction are perpendicular to each other, and the third direction is also perpendicular to the plane of the substrate.

[0009] The above-mentioned three-axis magnetic sensor is provided with a first magnetic field sensitive area, a second magnetic field sensitive area and a third magnetic field sensitive area on the plane of the substrate. The magnetic tunnel junction of the first magnetic field sensitive area has a pinning direction along the first direction, and the magnetic tunnel junction of the second magnetic field sensitive area has a pinning direction along the second direction, which can be used to detect the magnetic field in the first direction and the second direction respectively; the third magnetic field sensitive area is provided at a position corresponding to the magnetic field steering element on the plane of the substrate, and the magnetic tunnel junction located in the third magnetic field sensitive area has a pinning direction along the first direction / second direction, which can detect the magnetic field component of the first direction / second direction after the transformation by the magnetic field steering element, thereby realizing the magnetic field detection in the third direction. By building a magnetic field steering element into the substrate, the magnetic field in the corresponding direction can be detected by providing the first magnetic field sensitive area, the second magnetic field sensitive area and the third magnetic field sensitive area on the plane of the substrate, respectively, so as to realize the detection of the three-axis magnetic field, simplify the preparation process and improve the preparation yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is a schematic structural diagram of a three-axis magnetic sensor in one embodiment;

[0011] Figure 2 for Figure 1 A schematic diagram of the cross-sectional structure of the first magnetic field sensitive area of ​​the central three-axis magnetic sensor along A-A';

[0012] Figure 3 for Figure 1 A schematic diagram of the cross-sectional structure of the second magnetic field sensitive area of ​​the central three-axis magnetic sensor along B-B';

[0013] Figure 4 for Figure 1 A schematic diagram of a cross-sectional structure of the third magnetic field sensitive area of ​​the central three-axis magnetic sensor along BB';

[0014] Figure 5 for Figure 1 Another schematic cross-sectional structure diagram of the third magnetic field sensitive area of ​​the central three-axis magnetic sensor along BB';

[0015] Figure 6 An equivalent circuit diagram of an X-axis magnetic tunnel junction array forming a bridge in one embodiment;

[0016] Figure 7 A schematic diagram of the distribution and circuit connection of an X-axis magnetic tunnel junction array in one embodiment;

[0017] Figure 8 An equivalent circuit diagram of a bridge composed of a Y-axis magnetic tunnel junction array in one embodiment;

[0018] Fig. 9 A schematic diagram of the distribution and circuit connection of a Y-axis magnetic tunnel junction array in one embodiment;

[0019] Fig.10 and Fig.11 A schematic diagram of the principle of a Z-axis magnetic tunnel junction forming a bridge in one embodiment;

[0020] Fig.12 and Fig.13 A schematic diagram of the principle of a Z-axis magnetic tunnel junction forming a bridge in yet another embodiment;

[0021] Fig.14 and Fig.15 It is a schematic diagram of the principle of forming a bridge using a Z-axis magnetic tunnel junction in another embodiment;

[0022] Fig.16 A schematic diagram of a structure in which a Z-axis magnetic tunnel junction forms a magnetoresistive unit in one embodiment;

[0023] Fig.17 An equivalent circuit diagram of a bridge composed of a Z-axis magnetic tunnel junction in one embodiment;

[0024] Fig.18 A schematic diagram of the distribution and circuit connection of a Z-axis magnetic tunnel junction array in one embodiment;

[0025] Fig.19 is an equivalent circuit diagram of a bridge composed of a Z-axis magnetic tunnel junction in another embodiment;

[0026] Fig. 20 A schematic diagram of the distribution and circuit connection of a Z-axis magnetic tunnel junction array in another embodiment;

[0027] Fig.21 A schematic diagram of the principle of changing the direction of a magnetic field by using a magnetic field steering member in one embodiment;

[0028] Fig. 22 FIG. 1 is a schematic diagram of a structure in which a magnetoresistive unit is formed by a Z-axis magnetic tunnel junction in another embodiment. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0031] In one embodiment, Figures 1 to 4As shown, a three-axis magnetic sensor is provided, including a substrate 110, and a first magnetic field sensitive area 120, a second magnetic field sensitive area 130 and a third magnetic field sensitive area 140 arranged on the plane of the substrate 110. The substrate 110 is built with a magnetic field steering member 180, and the magnetic field steering member 180 is inclined between the third direction and the first direction / the second direction, and is used to steer the magnetic field in the third direction so that it has a magnetic field component in the first direction / the second direction. The first magnetic field sensitive area 120, the second magnetic field sensitive area 130 and the third magnetic field sensitive area 140 are all composed of magnetic tunnel junctions 150 connected in series, in parallel or in combination of series and parallel; the magnetic tunnel junction 150 located in the first magnetic field sensitive area 120 has a pinning direction along the first direction, and the magnetic tunnel junction 120 located in the second magnetic field sensitive area 130 has a pinning direction along the second direction; the third magnetic field sensitive area 140 is arranged at a position corresponding to the magnetic field steering member 180 on the plane of the substrate 110, and the magnetic tunnel junction 150 located in the third magnetic field sensitive area 140 has a pinning direction along the first direction / the second direction. The first direction, the second direction and the third direction are perpendicular to each other, and the third direction is also perpendicular to the plane of the substrate 110 .

[0032] Specifically, the first direction and the second direction may be the X-axis direction and the Y-axis direction, or may be the Y-axis direction and the X-axis direction, respectively. The third direction is the Z-axis direction, and the plane of the substrate 110 is the XY plane. For ease of understanding, the following description is based on the example that the first direction, the second direction, and the third direction are the X-axis direction, the Y-axis direction, and the Z-axis direction, respectively.

[0033] The magnetic tunnel junction 150 generally includes a free layer / tunnel barrier layer / pinned layer. Changes in the external magnetic field will cause changes in the magnetization direction of the free layer. When the magnetization direction of the free layer is positively parallel to the pinning direction of the pinned layer, the magnetic tunnel junction 150 is in a low resistance state; when the magnetization direction of the free layer is anti-parallel to the pinning direction of the pinned layer, the magnetic tunnel junction 150 is in a high resistance state. It can be seen that the magnetic field component of the external magnetic field parallel to the pinning direction can cause a change in the magnetization direction of the free layer, and the parallel state with the pinning direction of the pinned layer can cause a change in the resistance value of the magnetic tunnel junction 150. By connecting the magnetic tunnel junction 150 in series or in parallel or in a combination of series and parallel, an electrical signal corresponding to the component of the external magnetic field in the pinning direction can be output.

[0034] The magnetic tunnel junction 150 of the first magnetic field sensitive region 120 is arranged on the plane of the substrate 110 and has a pinning direction along the X-axis direction. Therefore, the first magnetic field sensitive region 120 can be used to detect the magnetic field in the X-axis direction.

[0035] The magnetic tunnel junction 150 of the second magnetic field sensitive region 130 is arranged on the plane of the substrate 110 and has a pinning direction along the Y-axis direction. Therefore, the second magnetic field sensitive region 130 can be used to detect the magnetic field in the Y-axis direction.

[0036] The specific pinning direction of the magnetic tunnel junction 150 in the third magnetic field sensitive area 140 corresponds to the tilting direction of the magnetic field steering element 180. If the magnetic field steering element 180 is tilted between the Z-axis direction and the X-axis direction, and is used to redirect the magnetic field in the Z-axis direction so that it has a magnetic field component in the X-axis direction, then the magnetic tunnel junction 150 in the third magnetic field sensitive area 140 has a pinning direction along the X-axis direction; if the magnetic field steering element 180 is tilted between the Z-axis direction and the Y-axis direction, and is used to redirect the magnetic field in the Z-axis direction so that it has a magnetic field component in the Y-axis direction, then the magnetic tunnel junction 150 in the third magnetic field sensitive area 140 has a pinning direction along the Y-axis direction. Therefore, the combination of the magnetic field steering element 180 and the third magnetic field sensitive area 140 can be used to detect the magnetic field in the Z-axis direction.

[0037] By building a magnetic field steering element 180 in the substrate 110, the first magnetic field sensitive area 120, the second magnetic field sensitive area 130 and the third magnetic field sensitive area 140 can be set on the plane of the substrate 110 to detect the magnetic field in the corresponding directions respectively, thereby realizing the detection of the three-axis magnetic field. All magnetic tunnel junctions 150 only need to be arranged on the plane of the substrate 110, which is compatible with the planar process, simplifies the preparation process and improves the preparation yield.

[0038] In one embodiment, the substrate 110 includes a substrate 112, an inclined structural layer 114, and a dielectric layer 116 which are stacked in sequence, the magnetic field steering member 180 is disposed on the inclined surface of the inclined structural layer 114, the inclined surface of the inclined structural layer 114 is inclined between the third direction and the first direction / the second direction, and the magnetic tunnel junction 150 is disposed on the plane of the dielectric layer 116, so that the magnetic tunnel junction 150 is located above the magnetic field steering member 180. It can be understood that in other embodiments, the magnetic tunnel junction 150 can also be located below the magnetic field steering member 180, for example, the upper surface of the substrate 112 can be used as the plane of the substrate 110, and the magnetic tunnel junction 150 can be disposed on the upper surface of the substrate 112.

[0039] The material of the inclined structure layer 114 can be silicon oxide (SiO x ), a magnetic field deflection member 180 can be generated on the inclined surface of the inclined structure by designing an inclined structure in the inclined structure layer 114, and the manufacturing process is simple. The inclined structure can be a groove or a protrusion, and accordingly, the inclined surface of the inclined structure is the inclined surface of the groove or the inclined surface of the protrusion. Figure 4 and Figure 5As shown, the magnetic field steering element 180 may be entirely located on the inclined surface of the inclined structure, or may be mostly located on the inclined surface of the inclined structure, with the remaining portion extending to the top of the inclined structure. The magnetic tunnel junction 150 of the third magnetic field sensitive region 140 is located on the plane of the dielectric layer 116 near the magnetic field steering element 180, and may be specifically arranged on both sides of the top of the magnetic field steering element 180, so as to Figure 4 and Figure 5 For example, the magnetic tunnel junction 150 of the third magnetic field sensitive region 140 can be arranged on the left and / or right side of the top of the magnetic field steering member 180, as long as the magnetic tunnel junction 150 is not located directly opposite to the top of the magnetic field steering member 180. Fig.21 As shown, the top of the magnetic field steering element 180 does not have a steering effect on the external magnetic field in the Z-axis direction. Therefore, the magnetic tunnel junction 150 is arranged on both sides of the top of the magnetic field steering element 180 to avoid failure to detect the magnetic field converted by the magnetic field steering element 180.

[0040] The inclination angle of the inclined surface of the inclined structural layer 114 is not unique and can be set according to actual needs. Considering that if the inclination angle is too small, the closer it is to parallel with the horizontal plane, the weaker the steering effect on the out-of-plane magnetic field; if the inclination angle is too large, the closer it is to perpendicular to the horizontal plane, on the one hand, the process difficulty increases, and on the other hand, it is not conducive to the deposition of the magnetic field steering member 114, and it is not conducive to the formation of a thicker magnetic field steering member 114, thereby affecting the steering effect. Based on this, in this embodiment, the inclination angle of the inclined surface of the inclined structural layer 114 can be specifically designed to be 15 degrees to 85 degrees, preferably, it can be designed to be 20 degrees to 80 degrees.

[0041] The thickness of the inclined structure layer 114 is 3-5 microns. A certain thickness is designed to facilitate the formation of an inclined structure.

[0042] Among them, the substrate 112 may include a CMOS wafer layer and a CMOS signal layer arranged on the CMOS wafer layer, and the CMOS wafer layer is integrated with an integrated circuit composed of several MOS tubes, which can process the analog signal generated by the first magnetic field sensitive area 120, the second magnetic field sensitive area 130 and the third magnetic field sensitive area 140 inducing the external magnetic field to obtain a digital signal, and the CMOS signal layer can realize the functions of receiving analog signals and outputting digital signals. Further, the CMOS signal layer can also be at least partially set in the form of a coil, which can be used as a self-test coil to generate a self-test magnetic field to check whether the sensor function is normal, and can also be used as a reset coil to generate a reset magnetic field to reset the magnetization direction of the free layer of the magnetic tunnel junction 150 of the first magnetic field sensitive area 120, the second magnetic field sensitive area 130 and the third magnetic field sensitive area 140. The CMOS signal layer can be in the form of a metal layer, an integrated circuit layer, etc., wherein the metal layer can be a copper layer, an aluminum layer, a copper alloy layer or an aluminum alloy layer. The substrate 112 of the three-axis magnetic sensor is integrated with a CMOS wafer layer and a CMOS signal layer, so that the three-axis magnetic sensor can be free of the need to integrate an additional chip for signal processing, which is conducive to reducing the package size of the three-axis magnetic sensor.

[0043] Furthermore, the substrate 112 may also include a protective layer disposed on the CMOS signal layer to protect the CMOS signal layer. The material of the protective layer may be silicon oxide (SiO x ), Silicon Nitride (SiN x ) or aluminum oxide (AlO x )wait.

[0044] The dielectric layer 116 may be a single-layer or multi-layer dielectric layer structure. In this embodiment, the dielectric layer 116 includes a first dielectric layer and a second dielectric layer. The first dielectric layer is located between the inclined structure layer 114 and the second dielectric layer. The magnetic tunnel junction 150 array is arranged on the plane of the second dielectric layer. The material of the first dielectric layer may be silicon nitride (SiN x ), the material of the second dielectric layer can be silicon oxide (SiO x ) or aluminum oxide (AlO x ) to facilitate chemical mechanical polishing (CMP) so that the second dielectric layer has a flat surface, and finally a magnetic tunnel junction 150 is formed on the second dielectric layer with the flat surface.

[0045] In one embodiment, the magnetic tunnel junctions 150 in the first magnetic field sensitive region 120 , the second magnetic field sensitive region 130 , and the third magnetic field sensitive region 140 may be arranged in an array on the plane of the dielectric layer 116 . By adopting an array layout, the layout can be made more compact, which is beneficial to reducing the packaging size of the three-axis magnetic sensor and is also beneficial to the electrical connection between the magnetic tunnel junctions 150 .

[0046] In one embodiment, the magnetic field deflector 180 includes a seed layer, a nickel iron (NiFe) layer and a cap layer stacked in sequence. The seed layer can be made of tantalum (Ta) or ruthenium (Ru). The cap layer can be made of titanium nitride (TiN x ) or Tantalum Nitride (TaN x ), which protects the nickel-iron (NiFe) layer.

[0047] In one embodiment, Figure 2-Figure 4 As shown, the three-axis magnetic sensor may further include an insulating layer 170, and the material of the insulating layer 170 may be silicon oxide (SiO x ) or aluminum oxide (AlO x ) etc. The insulating layer 170 covers the magnetic tunnel junction 150 to insulate and protect the magnetic tunnel junction 150 .

[0048] In one embodiment, Figure 1 As shown, the three-axis magnetic sensor also includes a coil 160 disposed on the substrate 110. The coil 160 is a multi-turn planar coil, which is used to reset the magnetic tunnel junctions 150 in the first magnetic field sensitive area 120, the second magnetic field sensitive area 130 and the third magnetic field sensitive area 140 when powered on, thereby reducing the noise of the magnetic sensor, improving the detection accuracy, and reducing cross-axis interference and hysteresis.

[0049] Specifically, the portion of the coil 160 that transmits current along the X-axis direction is arranged corresponding to the first magnetic field sensitive area 120; the portion of the coil 160 that transmits current along the Y-axis direction is arranged corresponding to the second magnetic field sensitive area 130. When powered on, the coil 160 can generate a magnetic field perpendicular to the current direction, that is, the portion of the coil 160 that transmits current along the X-axis direction can generate a magnetic field in the Y-axis direction, and reset the magnetization direction of the free layer of the magnetic tunnel junction 140 of the first magnetic field sensitive area 120, so that the magnetization direction is along the Y-axis direction; the portion of the coil 160 that transmits current along the Y-axis direction can generate a magnetic field in the X-axis direction, and reset the magnetization direction of the free layer of the magnetic tunnel junction 140 of the second magnetic field sensitive area 130, so that the magnetization direction is along the X-axis direction.

[0050] The distribution of the third magnetic field sensitive area 140 varies according to the different tilting modes of the magnetic field steering member 180. When the magnetic field steering member 180 is tilted in the Z-axis direction and the X-axis direction, the third magnetic field sensitive area 140 can be set at the portion of the coil 160 that transmits current along the X-axis direction (i.e., close to the first magnetic field sensitive area 120) and at a position corresponding to the magnetic field steering member 180; when the magnetic field steering member 180 is tilted between the Z-axis direction and the Y-axis direction, the third magnetic field sensitive area 140 can be set at the portion of the coil 160 that transmits current along the Y-axis direction (i.e., close to the second magnetic field sensitive area 130) and at a position corresponding to the magnetic field steering member 180.

[0051] Take the magnetic field deflection member 180 tilting between the Z-axis direction and the Y-axis direction as an example. Figure 1 As shown, the current in the coil 160 can be clockwise or counterclockwise. In addition, since the coil 160 is a planar coil composed of multiple turns of winding wire, the two parts of the coil 160 that are relatively arranged along the Y-axis direction have a current transmitted along the X-axis direction, and the two parts of the coil 160 that are relatively arranged along the X-axis direction have a current transmitted along the Y-axis direction. Combined with the correspondence between the first magnetic field sensitive area 120, the second magnetic field sensitive area 130, the third magnetic field sensitive area 140 and the direction of the current transmitted in the coil 160, and in order to make the layout more compact and effectively utilize the reset function of the coil 160, the number of the first magnetic field sensitive area 120 is two, distributed along the Y-axis direction, the number of the second magnetic field sensitive area 130 is two, distributed along the X-axis direction, and distributed on both sides of the axis where the two first magnetic field sensitive areas 120 are located. The number of the third magnetic field sensitive area 140 is two, distributed along the X-axis direction, and also distributed on both sides of the axis where the two first magnetic field sensitive areas 120 are located. In this way, the portion of the coil 160 that transmits current along the positive direction (+X) of the X axis and the portion that transmits current along the negative direction (-X) of the X axis correspond to a first magnetic field sensitive area 120, respectively, and the portion that transmits current along the positive direction (+Y) of the Y axis and the portion that transmits current along the negative direction (-Y) of the Y axis correspond to a second magnetic field sensitive area 130 and a third magnetic field sensitive area 140, respectively. After the coil 160 is arranged on the substrate 110, the coil 160 is energized to generate a magnetic field component perpendicular to the current direction. The magnetic field components generated by the coil 160 in the first magnetic field sensitive area 120 are in the positive direction and negative direction of the Y axis, and the magnetic field directions generated in the second magnetic field sensitive area 130 and the third magnetic field sensitive area 140 are in the positive direction and negative direction of the X axis. After the coil 160 is energized, the magnetic tunnel junctions 150 in the two first magnetic field sensitive areas 120, the two second magnetic field sensitive areas 130 and the two third magnetic field sensitive areas 140 can be reset by using the parts with different current directions to determine the initial magnetization direction of the free layer of the magnetic tunnel junction 150. The operation is simple and quick.

[0052] It can be understood that in other embodiments, if the magnetic field steering member 180 is tilted between the Z-axis direction and the X-axis direction, the two second magnetic field sensitive areas 130 can be distributed along the X-axis direction, the two first magnetic field sensitive areas 120 can be distributed along the Y-axis direction, and are distributed on both sides of the axis where the two second magnetic field sensitive areas 130 are located, and the two third magnetic field sensitive areas 140 can be distributed along the Y-axis direction, and are distributed on both sides of the axis where the two second magnetic field sensitive areas 130 are located.

[0053] The coil 160 may be arranged above or below the magnetic tunnel junction 150. When the coil 160 is arranged below the magnetic tunnel junction 150, at least part of the CMOS signal layer may be used as the coil 160. When the coil 160 is arranged above the magnetic tunnel junction 150, a metal layer may be provided on the insulating layer 170 and etched to form the coil 160. Furthermore, the insulating layer 170 may also adopt a multi-layer structure, and the coil 160 may also be wrapped by layered preparation to play a protective role.

[0054] like Figure 6 and Figure 7 As shown, Figure 6 The hollow arrow indicates the pinning direction of the magnetic tunnel junction 150 , and the solid arrow indicates the initial magnetization direction of the free layer of the magnetic tunnel junction 150 . Figure 7The hollow arrow indicates the direction of the current in the coil 160. A portion of the magnetic tunnel junction 150 located in the first magnetic field sensitive region 120 has a pinning direction along the positive direction (+X) of the X-axis direction, and another portion has a pinning direction along the negative direction (-X) of the X-axis direction. A portion of the magnetic tunnel junction 150 having a pinning direction along the positive direction of the X-axis direction is connected in series to form a magnetoresistive unit R11, and another portion is connected in series to form a magnetoresistive unit R13; a portion of the magnetic tunnel junction 150 having a pinning direction along the negative direction of the X-axis direction is connected in series to form a magnetoresistive unit R12, and another portion is connected in series to form a magnetoresistive unit R14. The magnetoresistive unit R11, the magnetoresistive unit R12, the magnetoresistive unit R13, and the magnetoresistive unit R14 contain the same number of magnetic tunnel junctions 150. The pinning direction of the magnetic tunnel junction 150 can be determined by the annealing magnetic field. Specifically, the magnetic tunnel junctions 150 constituting the magnetoresistance unit R11 and the magnetoresistance unit R13 are annealed in the positive direction of the X-axis direction, and the magnetic tunnel junctions 150 constituting the magnetoresistance unit R12 and the magnetoresistance unit R14 are annealed in the negative direction of the X-axis direction. The magnetic tunnel junctions 150 that need to be annealed in the same direction can be arranged in the same area, for example, the magnetic tunnel junctions 150 constituting the magnetoresistance unit R11 and the magnetoresistance unit R13 are arranged in the same area, and the magnetic tunnel junctions 150 constituting the magnetoresistance unit R12 and the magnetoresistance unit R14 are arranged in another same area. It is also possible to arrange the magnetic tunnel junctions 150 that need to be annealed in different directions in the same area based on other requirements, for example, in order to facilitate the circuit connection or magnetic reset between the magnetoresistance units, for example, the magnetic tunnel junctions 150 constituting the magnetoresistance unit R11 and the magnetoresistance unit R14 are arranged in the same area, and the magnetic tunnel junctions 150 constituting the magnetoresistance unit R12 and the magnetoresistance unit R13 are arranged in another same area. When the same area needs to be annealed in different directions, local laser annealing can be used.

[0055] The magnetoresistance units R11 and R14 have initial magnetization directions of the free layers in the positive direction of the Y-axis direction, and the magnetoresistance units R12 and R13 have initial magnetization directions of the free layers in the negative direction of the Y-axis direction. By arranging the magnetic tunnel junctions 150 constituting the magnetoresistance units R11 and R14 at the portion of the coil 160 that transmits current in the positive direction (+X) of the X-axis, and arranging the magnetic tunnel junctions 140 constituting the magnetoresistance units R12 and R13 at the portion of the coil 160 that transmits current in the negative direction (-X) of the X-axis, when the coil 160 is powered on, the magnetization direction of the free layer of the magnetic tunnel junction 150 of the first magnetic field sensitive region 120 can be magnetically reset accordingly.

[0056] One end of the magnetoresistance unit R11 is connected to the output terminal P1, and the other end of the magnetoresistance unit R11 is connected to the power supply terminal VCC1; one end of the magnetoresistance unit R14 is connected to the output terminal N1, and the other end of the magnetoresistance unit R14 is connected to the power supply terminal VCC1; one end of the magnetoresistance unit R12 is connected to the output terminal P1, and the other end of the magnetoresistance unit R12 is connected to the ground terminal GND; one end of the magnetoresistance unit R13 is connected to the output terminal N1, and the other end of the magnetoresistance unit R13 is connected to the ground terminal GND.

[0057] When the sensor is working, when the external magnetic field has a component along the X-axis direction, the magnetization direction of the free layer of the magnetic tunnel junction 150 produces different rotation angles depending on the magnitude of the magnetic field component, causing the resistance of the magnetoresistive unit R11 / magnetoresistive unit R13 to increase or decrease. The resistance change of the magnetoresistive unit R12 / magnetoresistive unit R14 is opposite to the resistance change of the magnetoresistive unit R11 / magnetoresistive unit R13, and the change magnitude is equal. The differential signal S1 of the X-axis bridge produces an approximately linear change relationship with the X-axis component of the external magnetic field, as shown in the following formula:

[0058]

[0059] Among them, MR and H k represents the intrinsic properties of the magnetic tunnel junction 150, which are magnetoresistivity and anisotropy field; V P1 Represents the output signal of output terminal P1, V N1 represents the output signal of the output terminal N1; Hx represents the X-axis component of the external magnetic field.

[0060] like Figure 8 and Fig. 9 As shown, Figure 8 The hollow arrow indicates the pinning direction of the magnetic tunnel junction 150 , and the solid arrow indicates the initial magnetization direction of the free layer of the magnetic tunnel junction 150 . Fig. 9The hollow arrow indicates the direction of the current in the coil 160. A portion of the magnetic tunnel junction 150 located in the second magnetic field sensitive region 130 has a pinning direction along the positive direction (+Y) of the Y-axis direction, and another portion has a pinning direction along the negative direction (-Y) of the Y-axis direction. A portion of the magnetic tunnel junction 150 having a pinning direction along the positive direction of the Y-axis direction is connected in series to form a magnetoresistive unit R21, and another portion is connected in series to form a magnetoresistive unit R23; a portion of the magnetic tunnel junction 150 having a pinning direction along the negative direction of the Y-axis direction is connected in series to form a magnetoresistive unit R22, and another portion is connected in series to form a magnetoresistive unit R24. The magnetoresistive unit R21, the magnetoresistive unit R22, the magnetoresistive unit R23, and the magnetoresistive unit R24 contain the same number of magnetic tunnel junctions 150. The pinning direction of the magnetic tunnel junction 150 can be determined by the annealing magnetic field. The magnetic tunnel junction 150 constituting the magnetoresistance unit R21 and the magnetoresistance unit R23 is annealed along the positive direction of the Y-axis direction, and the magnetic tunnel junction 150 constituting the magnetoresistance unit R22 and the magnetoresistance unit R24 is annealed along the negative direction of the Y-axis direction.

[0061] The magnetoresistance units R23 and R24 have initial magnetization directions of the free layers in the positive direction of the X-axis direction, and the magnetoresistance units R21 and R22 have initial magnetization directions of the free layers in the negative direction of the X-axis direction. By arranging the magnetic tunnel junctions 150 constituting the magnetoresistance units R23 and R24 at the portion of the coil 160 that transmits current in the negative direction (-Y) of the Y-axis, and arranging the magnetic tunnel junctions 150 constituting the magnetoresistance units R21 and R22 at the portion of the coil 160 that transmits current in the positive direction (+Y) of the Y-axis, when the coil 160 is powered on, the magnetization direction of the free layer of the magnetic tunnel junctions 150 of the second magnetic field sensitive region 130 can be magnetically reset accordingly.

[0062] One end of the magnetoresistance unit R21 is connected to the output terminal P2, and the other end of the magnetoresistance unit R21 is connected to the power supply terminal VCC2, one end of the magnetoresistance unit R22 is connected to the output terminal N2, and the other end of the magnetoresistance unit R22 is connected to the power supply terminal VCC2; one end of the magnetoresistance unit R24 is connected to the output terminal P2, and the other end of the magnetoresistance unit R24 is connected to the ground terminal GND, one end of the magnetoresistance unit R23 is connected to the output terminal N2, and the other end of the magnetoresistance unit R23 is connected to the ground terminal GND.

[0063] When the sensor is working, when the external magnetic field has a component along the Y-axis direction, the magnetization direction of the free layer of the magnetic tunnel junction 150 produces different rotation angles depending on the magnitude of the magnetic field component, causing the resistance of the magnetoresistive unit R21 / magnetoresistive unit R23 to increase or decrease. The resistance change of the magnetoresistive unit R22 / magnetoresistive unit R24 is opposite to the resistance change of the magnetoresistive unit R21 / magnetoresistive unit R23, and the change magnitude is equal. The differential signal S2 of the Y-axis bridge produces an approximately linear change relationship with the Y-axis component of the external magnetic field, as shown in the following formula:

[0064]

[0065] Among them, MR and H k represents the intrinsic properties of the magnetic tunnel junction 150, which are magnetoresistivity and anisotropy field; V P2 Represents the output signal of output terminal P2, V N2 represents the output signal of the output terminal N2; Hy represents the Y-axis component of the external magnetic field.

[0066] The method of forming a magnetoresistive unit by the magnetic tunnel junction 150 in the third magnetic field sensitive region 140 and then connecting the magnetoresistive units to form a Z-axis bridge for magnetic field detection is not the only one.

[0067] In one embodiment, Figure 10-15 As shown, the magnetic field steering member 180 includes a first soft magnet 182 and a second soft magnet 184 arranged in mirror symmetry; the magnetic tunnel junction 150 located in the third magnetic field sensitive area 140 includes a plurality of first magnetic tunnel junctions arranged near the first soft magnet 182, and a plurality of second magnetic tunnel junctions arranged near the second soft magnet 184, and the first magnetic tunnel junction and the second magnetic tunnel junction are arranged in mirror symmetry. The first soft magnet 182 and the second soft magnet 184 distort the magnetic field in the external Z-axis direction, so that it generates a component perpendicular to the Z-axis direction (for example, the X-axis direction or the Y-axis direction) to form a magnetic field to be detected in the third magnetic field sensitive area 140. At least part of the first magnetic tunnel junction and the second magnetic tunnel junction has a first sensitivity direction, and the first magnetic tunnel junction with the first sensitivity direction is connected in series and / or in parallel to form a plurality of first magnetoresistance units, and the second magnetic tunnel junction with the first sensitivity direction is connected in series and / or in parallel to form a plurality of second magnetoresistance units, and the number of magnetic tunnel junctions 150 included in the first magnetoresistance unit and the second magnetoresistance unit is equal. Among them, the sensitivity direction of the first magnetic tunnel junction and the second magnetic tunnel junction can be determined by the pinning direction of the magnetic tunnel junction 150. For example, when the magnetic tunnel junction 150 has a pinning direction along the positive direction of the Y axis, the magnetic tunnel junction 150 has a sensitivity direction along the positive direction of the Y axis.

[0068] like Fig.10As shown, when the mirror-symmetric symmetric planes of the first soft magnetic body 182 and the second soft magnetic body 184 are consistent with the mirror-symmetric symmetric planes of the first magnetic tunnel junction and the second magnetic tunnel junction, under the steering action of the first soft magnetic body 182 and the second soft magnetic body 184, the magnetic field directions of the magnetic field to be detected at the positions of the first magnetic tunnel junction and the second magnetic tunnel junction are opposite and the magnitudes of the magnetic field are equal, that is, the magnetic field directions of the magnetic field to be detected at the positions of the first magnetic resistance unit and the second magnetic resistance unit are opposite and the magnitudes of the magnetic field are equal. Because the sensitivity direction of the first magnetic tunnel junction constituting the first magnetic resistance unit and the sensitivity direction of the second magnetic tunnel junction constituting the second magnetic resistance unit are both the first sensitivity direction, under the action of the magnetic field to be detected, the resistance of the first magnetic resistance unit increases or decreases, and the resistance of the second magnetic resistance unit changes in the opposite direction and the same magnitude as the resistance of the first magnetic resistance unit, so that the first magnetic resistance unit and the second magnetic resistance unit can be connected to form a Z-axis bridge to detect the magnetic field converted by the magnetic field steering member 180, thereby realizing the detection of the external Z-axis direction magnetic field. Since the magnetic tunnel junctions constituting the first magnetoresistance unit and the second magnetoresistance unit both have the first sensitivity direction, that is, the same pinning direction, the annealing magnetic field in the same direction can be uniformly adopted, which is conducive to simplifying the preparation process.

[0069] The inclined structure in the substrate 110 may be designed to include a first inclined plane and a second inclined plane that are arranged in mirror symmetry, and a first soft magnetic body 182 and a second soft magnetic body 184 are formed on the first inclined plane and the second inclined plane, respectively, so that the first soft magnetic body 182 and the second soft magnetic body 184 are arranged in mirror symmetry. In addition, it can be understood that the inclined structure may be one or multiple inclined structures with the same structure, and accordingly, the first soft magnetic body 182 and the second soft magnetic body 184 may be arranged in one or more pairs based on the number of inclined structures.

[0070] like Fig.10 , Fig.12 as well as Fig.14 As shown, the side of the first soft magnet 182 away from the second soft magnet 184 can be used as the outer side of the first soft magnet 182, and the side of the first soft magnet 182 close to the second soft magnet 184 can be used as the inner side of the first soft magnet 182; the side of the second soft magnet 184 close to the first soft magnet 182 can be used as the inner side of the second soft magnet 184, and the side of the second soft magnet 184 away from the first soft magnet 182 can be used as the outer side of the second soft magnet 184.

[0071] In one embodiment, Fig.10 and Fig.11As shown, the first magnetoresistance unit includes a first magnetoresistance unit R31 formed by connecting in series and / or in parallel a plurality of first magnetic tunnel junctions with a first sensitivity direction located outside the first soft magnetic body 182, and the second magnetoresistance unit includes a second magnetoresistance unit R34 formed by connecting in series and / or in parallel a plurality of second magnetic tunnel junctions with a first sensitivity direction located outside the second soft magnetic body 184, and the first magnetoresistance unit R31 and the second magnetoresistance unit R34 are connected to form a Z-axis bridge. Specifically, as Fig.11 As shown, a first magnetoresistance unit R31 is connected to the output terminal N3 and the power supply terminal VCC3, and the initial magnetization direction of the free layer is the negative direction of the X axis. Another first magnetoresistance unit R31 is connected to the output terminal P3 and the ground terminal GND, and the initial magnetization direction of the free layer is the positive direction of the X axis. A second magnetoresistance unit R34 is connected to the output terminal P3 and the power supply terminal VCC3, and the initial magnetization direction of the free layer is the negative direction of the X axis. Another second magnetoresistance unit R34 is connected to the output terminal N3 and the ground terminal GND, and the initial magnetization direction of the free layer is the positive direction of the X axis. Fig.10 and Fig.11 As shown, since the pinning direction of the first magnetic tunnel junction constituting the first magnetoresistance unit R31 and the pinning direction of the second magnetic tunnel junction constituting the second magnetoresistance unit R34 are both along the negative direction of the Y-axis direction, and the magnetic field directions of the magnetic field to be detected at the positions of the first magnetoresistance unit R31 and the second magnetoresistance unit R34 are opposite and the magnitudes of the magnetic field are equal, under the action of the magnetic field to be detected, the resistance of the first magnetoresistance unit R31 increases or decreases, and the resistance change of the second magnetoresistance unit R34 is opposite to the resistance change direction of the first magnetoresistance unit R31, and the change magnitude is equal, the first magnetoresistance unit R31 and the second magnetoresistance unit R34 can constitute a Z-axis bridge, and the differential signal S3 of the Z-axis bridge produces an approximately linear change relationship with the Z-axis component of the external magnetic field, as shown in the following formula:

[0072]

[0073] Among them, MR and H k represents the intrinsic properties of the magnetic tunnel junction 150, which are magnetoresistivity and anisotropy field; V P3 Represents the output signal of output terminal P3, V N3 represents the output signal of the output terminal N3; Hz represents the Z-axis component of the external magnetic field; γ1 represents the proportional factor of the magnetic field size at the positions of the first magnetic resistance unit R31 and the second magnetic resistance unit R34 after the Z-axis component of the external magnetic field is twisted by the magnetic field steering member 150.

[0074] It should be noted that the component of the external magnetic field along the Y-axis direction is in the same direction at the locations of the first magnetoresistance unit R31 and the second magnetoresistance unit R34, and the pinning direction of the first magnetic tunnel junction constituting the first magnetoresistance unit R31 and the pinning direction of the second magnetic tunnel junction constituting the second magnetoresistance unit R34 are both along the negative direction of the Y-axis direction, so the change in resistance caused by the component of the external magnetic field along the Y-axis direction is consistent, so that the Z-axis bridge has no signal output for the component of the external magnetic field along the Y-axis direction.

[0075] In one embodiment, Fig.12 and Fig.13 As shown, the first magnetoresistance unit includes a first magnetoresistance unit R32 formed by connecting in series and / or in parallel a plurality of first magnetic tunnel junctions with a first sensitivity direction located inside the first soft magnetic body 182, and the second magnetoresistance unit includes a second magnetoresistance unit R33 formed by connecting in series and / or in parallel a plurality of second magnetic tunnel junctions with a first sensitivity direction located inside the second soft magnetic body 184, and the first magnetoresistance unit R32 and the second magnetoresistance unit R33 are connected to form a Z-axis bridge. Specifically, as Fig.13 As shown, a first magnetoresistance unit R32 is connected to the output terminal N4 and the power supply terminal VCC4, and the initial magnetization direction of the free layer is the negative direction of the X axis. Another first magnetoresistance unit R32 is connected to the output terminal P4 and the ground terminal GND, and the initial magnetization direction of the free layer is the positive direction of the X axis. A second magnetoresistance unit R33 is connected to the output terminal P4 and the power supply terminal VCC4, and the initial magnetization direction of the free layer is the negative direction of the X axis. Another second magnetoresistance unit R33 is connected to the output terminal N4 and the ground terminal GND, and the initial magnetization direction of the free layer is the positive direction of the X axis. Fig.12 and Fig.13 As shown, since the pinning direction of the first magnetic tunnel junction constituting the first magnetoresistance unit R32 and the pinning direction of the second magnetic tunnel junction constituting the second magnetoresistance unit R33 are both along the negative direction of the Y-axis direction, and the magnetic field directions of the magnetic field to be detected at the positions of the first magnetoresistance unit R32 and the second magnetoresistance unit R33 are opposite and the magnitudes of the magnetic field are equal, under the action of the magnetic field to be detected, the resistance of the first magnetoresistance unit R32 increases or decreases, and the resistance change of the second magnetoresistance unit R33 is opposite to the resistance change direction of the first magnetoresistance unit R32, and the change magnitude is equal, the first magnetoresistance unit R32 and the second magnetoresistance unit R33 can constitute a Z-axis bridge, and the differential signal S4 of the Z-axis bridge produces an approximately linear change relationship with the Z-axis component of the external magnetic field, as shown in the following formula:

[0076]

[0077] Among them, MR and H k represents the intrinsic properties of the magnetic tunnel junction 150, which are magnetoresistivity and anisotropy field; V P4 Represents the output signal of output terminal P4, VN4 represents the output signal of the output terminal N4; Hz represents the Z-axis component of the external magnetic field; γ2 represents the proportional factor of the magnetic field size at the positions of the first magnetic resistance unit R32 and the second magnetic resistance unit R33 after the Z-axis component of the external magnetic field is twisted by the magnetic field steering member 150.

[0078] In one embodiment, Fig.14 and Fig.15 As shown, the first magnetoresistance unit includes a first magnetoresistance unit R31 formed by a plurality of first magnetic tunnel junctions with a first sensitivity direction connected in series and / or in parallel on the outside of the first soft magnet 182, and a first magnetoresistance unit R32 formed by a plurality of first magnetic tunnel junctions with a first sensitivity direction connected in series and / or in parallel on the inside of the first soft magnet 182; the second magnetoresistance unit includes a second magnetoresistance unit R33 formed by a plurality of second magnetic tunnel junctions with a first sensitivity direction connected in series and / or in parallel on the inside of the second soft magnet, and a second magnetoresistance unit R34 formed by a plurality of second magnetic tunnel junctions with a first sensitivity direction connected in series and / or in parallel on the outside of the second soft magnet; the first magnetoresistance unit R31, the first magnetoresistance unit R32, the second magnetoresistance unit R33 and the second magnetoresistance unit R34 are connected to form a Z-axis bridge. Specifically, as Fig.15 As shown, a first magnetoresistance unit R31 and a second magnetoresistance unit R33 are connected in series or in parallel to the output terminal N5 and the power supply terminal VCC5, and the initial magnetization direction of the free layer is the negative direction of the X axis. Another first magnetoresistance unit R31 and another second magnetoresistance unit R33 are connected in series or in parallel to the output terminal P5 and the ground terminal GND, and the initial magnetization direction of the free layer is the positive direction of the X axis. A first magnetoresistance unit R32 and a second magnetoresistance unit R34 are connected in series or in parallel to the output terminal N5 and the ground terminal GND, and the initial magnetization direction of the free layer is the positive direction of the X axis. Another first magnetoresistance unit R32 and another second magnetoresistance unit R34 are connected in series or in parallel to the output terminal P5 and the power supply terminal VCC5, and the initial magnetization direction of the free layer is the negative direction of the X axis. Fig.14 and Fig.15As shown, it can be known from the pinning direction of the magnetic tunnel junction 150 constituting the first magnetoresistance unit R31, the first magnetoresistance unit R32, the second magnetoresistance unit R33 and the second magnetoresistance unit R34 and the magnetic field direction and magnitude of the magnetic field to be detected at the location that under the action of the magnetic field to be detected, the resistance of the whole formed by the first magnetoresistance unit R31 and the second magnetoresistance unit R33 increases or decreases, and the resistance change of the whole formed by the first magnetoresistance unit R32 and the second magnetoresistance unit R34 is opposite to the resistance change direction of the whole formed by the first magnetoresistance unit R31 and the second magnetoresistance unit R33, and the change magnitude is equal. Therefore, the differential signal S5 of the Z bridge formed by the first magnetoresistance unit R31, the first magnetoresistance unit R32, the second magnetoresistance unit R33 and the second magnetoresistance unit R34 produces an approximately linear change relationship with the Z-axis component of the external magnetic field, as shown in the following formula:

[0079]

[0080] Among them, MR and H k represents the intrinsic properties of the magnetic tunnel junction 150, which are magnetoresistivity and anisotropy field; V P5 Represents the output signal of output terminal P5, V N5 Represents the output signal of the output terminal N5; Hz represents the Z-axis component of the external magnetic field; γ1 represents the proportional factor of the magnetic field size at the first magnetoresistance unit R31 and the second magnetoresistance unit R34 after the Z-axis component of the external magnetic field is twisted by the magnetic field steering device 150; γ2 represents the proportional factor of the magnetic field size at the first magnetoresistance unit R32 and the second magnetoresistance unit R33 after the Z-axis component of the external magnetic field is twisted by the magnetic field steering device 150.

[0081] In this embodiment, the power consumption of the Z-axis bridge can be reduced by connecting the first magnetoresistance unit R31 and the second magnetoresistance unit R33 in series or in parallel to form a whole, and connecting the first magnetoresistance unit R32 and the second magnetoresistance unit R34 in series or in parallel to form a whole, and then constructing the Z-axis bridge.

[0082] In one embodiment, Figure 16-Figure 22 As shown, at least part of the first magnetic tunnel junction and the second magnetic tunnel junction has a second sensitivity direction, and the first sensitivity direction and the second sensitivity direction are opposite; the first magnetic tunnel junctions with the second sensitivity direction are connected in series and / or in parallel to form a plurality of third magnetoresistance units, and the second magnetic tunnel junctions with the second sensitivity direction are connected in series and / or in parallel to form a plurality of fourth magnetoresistance units, and the first magnetoresistance unit, the second magnetoresistance unit, the third magnetoresistance unit and the fourth magnetoresistance unit include an equal number of magnetic tunnel junctions 150.

[0083] When the mirror-symmetrical symmetry planes of the first soft magnet 182 and the second soft magnet 184 are consistent with the mirror-symmetrical symmetry planes of the first magnetic tunnel junction and the second magnetic tunnel junction, under the steering action of the first soft magnet 182 and the second soft magnet 184, the magnetic field directions of the magnetic fields to be detected at the locations of the first magnetic tunnel junction and the second magnetic tunnel junction are opposite and the magnetic field magnitudes are equal, that is, the magnetic field directions of the magnetic fields to be detected at the locations of the first magnetoresistance unit and the second magnetoresistance unit are opposite and the magnetic field magnitudes are equal, the magnetic field directions of the magnetic fields to be detected at the locations of the third magnetoresistance unit and the fourth magnetoresistance unit are opposite and the magnetic field magnitudes are equal, and the magnetic field directions of the magnetic fields to be detected at the locations of the first magnetoresistance unit and the third magnetoresistance unit are the same and the magnetic field magnitudes are equal. Furthermore, because the sensitivity direction of the first magnetic tunnel junction constituting the first magnetoresistance unit and the sensitivity direction of the second magnetic tunnel junction constituting the second magnetoresistance unit are both the first sensitivity direction, the sensitivity direction of the first magnetic tunnel junction constituting the third magnetoresistance unit and the sensitivity direction of the second magnetic tunnel junction constituting the fourth magnetoresistance unit are both the second sensitivity direction opposite to the first sensitivity direction, thus, under the action of the magnetic field to be detected, the resistance of the first magnetoresistance unit and the fourth magnetoresistance unit both increases or decreases, and the resistance change direction of the second magnetoresistance unit and the third magnetoresistance unit is opposite to that of the first magnetoresistance unit and the fourth magnetoresistance unit, and the change magnitude is equal, so that the first magnetoresistance unit, the second magnetoresistance unit, the third magnetoresistance unit and the fourth magnetoresistance unit can be connected to form a Z-axis bridge to detect the magnetic field converted by the magnetic field steering member 180, thereby realizing the detection of the external Z-axis direction magnetic field.

[0084] It is understandable that in the actual process, there may be process errors, which may cause the mirror-symmetric symmetry planes of the first soft magnetic body 182 and the second soft magnetic body 184 to be inconsistent with the mirror-symmetric symmetry planes of the first magnetic tunnel junction and the second magnetic tunnel junction. Fig. 22As shown, the symmetry planes of the first magnetic tunnel junction and the second magnetic tunnel junction are offset toward the negative direction of the Y axis relative to the symmetry planes of the first soft magnet 182 and the second soft magnet 184, and the magnetic field to be detected at the positions where the first magnetoresistance unit, the second magnetoresistance unit, the third magnetoresistance unit and the fourth magnetoresistance unit are located changes due to the offset. Because of the offset, the changes of the magnetic field to be detected at the first magnetoresistance unit and the corresponding fourth magnetoresistance unit are the same, while the sensitivity directions of the magnetic tunnel junctions 150 of the first magnetoresistance unit and the corresponding fourth magnetoresistance unit are opposite. Similarly, the changes of the magnetic field to be detected at the second magnetoresistance unit and the corresponding third magnetoresistance unit are the same, while the sensitivity directions of the magnetic tunnel junctions 150 of the second magnetoresistance unit and the corresponding third magnetoresistance unit are opposite. In this way, a Z-axis bridge is formed by the first magnetoresistance unit, the second magnetoresistance unit, the third magnetoresistance unit and the fourth magnetoresistance unit. In the case of inconsistent symmetry planes due to process errors, the detection of the external Z-axis direction magnetic field can still be achieved, and by connecting the first magnetoresistance unit and the corresponding fourth magnetoresistance unit in series or in parallel, and connecting the second magnetoresistance unit and the corresponding third magnetoresistance unit in series or in parallel, the zero point offset and sensitivity change caused by the process alignment error can be effectively offset or reduced.

[0085] In one embodiment, Fig.16 and Fig.17As shown, the first magnetoresistance unit includes a first magnetoresistance unit R31 formed by a plurality of first magnetic tunnel junctions with a first sensitivity direction located outside the first soft magnet 182 and connected in series and / or in parallel, and a first magnetoresistance unit R32 formed by a plurality of first magnetic tunnel junctions with a first sensitivity direction located inside the first soft magnet 182 and connected in series and / or in parallel, and the second magnetoresistance unit includes a second magnetoresistance unit R33 formed by a plurality of second magnetic tunnel junctions with a first sensitivity direction located inside the second soft magnet 184 and connected in series and / or in parallel, and a second magnetoresistance unit R34 formed by a plurality of second magnetic tunnel junctions with a first sensitivity direction located outside the second soft magnet 184 and connected in series and / or in parallel; The third magnetoresistance unit includes a third magnetoresistance unit R33' formed by connecting several first magnetic tunnel junctions with a second sensitivity direction in series and / or in parallel on the inner side of the first soft magnet 182, and a third magnetoresistance unit R34' formed by connecting several first magnetic tunnel junctions with a second sensitivity direction in series and / or in parallel on the outer side of the first soft magnet 182. The fourth magnetoresistance unit includes a fourth magnetoresistance unit R31' formed by connecting several second magnetic tunnel junctions with a second sensitivity direction in series and / or in parallel on the outer side of the second soft magnet 184, and a fourth magnetoresistance unit R32' formed by connecting several second magnetic tunnel junctions with a second sensitivity direction in series and / or in parallel on the inner side of the second soft magnet 184. The first magnetoresistance unit R31, the first magnetoresistance unit R32, the second magnetoresistance unit R33, the second magnetoresistance unit R34, the fourth magnetoresistance unit R31', the fourth magnetoresistance unit R32', the third magnetoresistance unit R33' and the third magnetoresistance unit R34' are connected to form a Z-axis bridge.

[0086] Specifically, Fig.17 and Fig.18 As shown, the first magnetic resistance unit R31 and the second magnetic resistance unit R33 are connected in series or in parallel to form a first resistor, the first magnetic resistance unit R32 and the second magnetic resistance unit R34 are connected in series or in parallel to form a second resistor, the third magnetic resistance unit R34' and the fourth magnetic resistance unit R32' are connected in series or in parallel to form a third resistor, and the third magnetic resistance unit R33' and the fourth magnetic resistance unit R31' are connected in series or in parallel to form a fourth resistor. A first resistor and a fourth resistor are connected in parallel to the output terminal N6 and the power supply terminal VCC6, another first resistor and another fourth resistor are connected in parallel to the output terminal P6 and the ground terminal GND; a second resistor and a third resistor are connected in parallel to the output terminal P6 and the power supply terminal VCC6, and another second resistor and another third resistor are connected in parallel to the output N6 and the ground terminal GND.

[0087] When the mirror-symmetrical symmetry plane of the first soft magnet 182 and the second soft magnet 184 is consistent with the mirror-symmetrical symmetry plane of the first magnetic tunnel junction and the second magnetic tunnel junction, the magnetic field to be measured at the first magnetoresistance unit R31 and the third magnetoresistance unit R34' is γ1Hz, the magnetic field to be measured at the first magnetoresistance unit R32 and the third magnetoresistance unit R33' is γ2Hz, the magnetic field to be measured at the second magnetoresistance unit R33 and the fourth magnetoresistance unit R32' is -γ2Hz, and the magnetic field to be measured at the second magnetoresistance unit R34 and the fourth magnetoresistance unit R31' is -γ1Hz. Furthermore, because the sensitivity direction of the magnetic tunnel junction 150 constituting the first magnetoresistance unit R31, the first magnetoresistance unit R32, the second magnetoresistance unit R33 and the second magnetoresistance unit R34 is opposite to the sensitivity direction of the magnetic tunnel junction 150 constituting the third magnetoresistance unit R34', the third magnetoresistance unit R33', the fourth magnetoresistance unit R32' and the fourth magnetoresistance unit R31', under the action of the magnetic field to be detected, the resistance of the whole formed by the first resistor and the fourth resistor in parallel increases or decreases, and the resistance change of the whole formed by the second resistor and the third resistor in parallel is opposite to the resistance change of the whole formed by the first resistor and the fourth resistor in parallel, and the change size is equal, so the first resistor, the second resistor, the third resistor and the fourth resistor can form a Z-axis bridge.

[0088] When there is a process error, take the bridge arm formed by the first resistor and the fourth resistor as an example, that is, take the bridge arm formed by the first magnetic resistance unit R31, the second magnetic resistance unit R33, the third magnetic resistance unit R33' and the fourth magnetic resistance unit R31' as an example. Fig. 22 As shown, due to process errors, the magnetic field to be detected at the position of the first magnetoresistance unit R31 is (γ1+Δγ1) Hz, and the magnetic field to be detected at the position of the fourth magnetoresistance unit R31' is -(γ1-Δγ1) Hz. Because the sensitivity directions of the magnetic tunnel junctions 150 constituting the first magnetoresistance unit R31 and the fourth magnetoresistance unit R31' are opposite, the zero point offset and sensitivity change caused by the process alignment error can be effectively offset or reduced by connecting the first magnetoresistance unit R31 and the fourth magnetoresistance unit R31' in parallel. Similarly, the zero point offset and sensitivity change caused by the process alignment error can be effectively offset or reduced by connecting the second magnetoresistance unit R33 and the third magnetoresistance unit R33' in parallel.

[0089] In another embodiment, Fig.19 and Fig. 20As shown, the first magnetic resistance unit R31 and the second magnetic resistance unit R33 are connected in series or in parallel to form a first resistor, the first magnetic resistance unit R32 and the second magnetic resistance unit R34 are connected in series or in parallel to form a second resistor, the third magnetic resistance unit R34' and the fourth magnetic resistance unit R32' are connected in series or in parallel to form a third resistor, and the third magnetic resistance unit R33' and the fourth magnetic resistance unit R31' are connected in series or in parallel to form a fourth resistor. A first resistor and a fourth resistor are connected in series to the output terminal N6 and the power supply terminal VCC6, another first resistor and another fourth resistor are connected in series to the output terminal P6 and the ground terminal GND; a second resistor and a third resistor are connected in series to the output terminal P6 and the power supply terminal VCC6, and another second resistor and another third resistor are connected in series to the output N6 and the ground terminal GND.

[0090] Similarly, when the mirror-symmetric symmetry plane of the first soft magnetic body 182 and the second soft magnetic body 184 is consistent with the mirror-symmetric symmetry plane of the first magnetic tunnel junction and the second magnetic tunnel junction, the magnetic field to be measured at the first magnetic resistance unit R31 and the third magnetic resistance unit R34' is γ1Hz, the magnetic field to be measured at the first magnetic resistance unit R32 and the third magnetic resistance unit R33' is γ2Hz, the magnetic field to be measured at the second magnetic resistance unit R33 and the fourth magnetic resistance unit R32' is -γ2Hz, and the magnetic field to be measured at the second magnetic resistance unit R34 and the fourth magnetic resistance unit R31' is -γ1Hz. In addition, the sensitivity direction of the magnetic tunnel junction 150 constituting the first magnetic resistance unit R31, the first magnetic resistance unit R32, the second magnetic resistance unit R33, and the second magnetic resistance unit R34 is opposite to the sensitivity direction of the magnetic tunnel junction 150 constituting the third magnetic resistance unit R34', the third magnetic resistance unit R33', the fourth magnetic resistance unit R32', and the fourth magnetic resistance unit R31'. Under the action of the magnetic field to be detected, the resistance of the whole formed by the first resistor and the fourth resistor in series increases or decreases, and the resistance change of the whole formed by the second resistor and the third resistor in series is opposite to the resistance change of the whole formed by the first resistor and the fourth resistor in series, and the change size is equal, so the first resistor, the second resistor, the third resistor and the fourth resistor can form a Z-axis bridge. It can be understood that the Z-axis bridge in this embodiment can also effectively offset or reduce the zero point offset and sensitivity change caused by the process alignment error, which will not be repeated here.

[0091] It is understood that in other embodiments, Fig.11The Z-axis bridge formed by the first magnetoresistance unit R31 and the second magnetoresistance unit R34 shown in the figure can also offset or reduce the zero point offset and sensitivity change caused by the process alignment error by connecting the corresponding fourth magnetoresistance unit R31' and the corresponding third magnetoresistance unit R34' in series or in parallel. Specifically, the first magnetoresistance unit R31 and the fourth magnetoresistance unit R31' are connected in series or in parallel as a whole as a bridge arm, and the second magnetoresistance unit R34 and the third magnetoresistance unit R34' are connected in series or in parallel as a whole as a bridge arm to form the Z-axis bridge.

[0092] It can be understood that in other embodiments, Fig.13 The Z-axis bridge formed by the first magnetoresistance unit R32 and the second magnetoresistance unit R33 shown in the figure can also offset or reduce the zero point offset and sensitivity change caused by the process alignment error by connecting the corresponding fourth magnetoresistance unit R32' and the corresponding third magnetoresistance unit R33' in series or in parallel. Specifically, the first magnetoresistance unit R32 and the fourth magnetoresistance unit R32' are connected in series or in parallel as a whole as a bridge arm, and the second magnetoresistance unit R33 and the third magnetoresistance unit R33' are connected in series or in parallel as a whole as a bridge arm to form the Z-axis bridge.

[0093] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0094] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the utility model patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A three-axis magnetic sensor, characterized in that: include: A substrate, wherein the substrate has a magnetic field steering member built therein, wherein the magnetic field steering member is inclined between the third direction and the first direction / the second direction, and is used to redirect the magnetic field in the third direction so that it has a magnetic field component in the first direction / the second direction; A first magnetic field sensitive area, a second magnetic field sensitive area and a third magnetic field sensitive area are arranged on the plane of the substrate, wherein the first magnetic field sensitive area, the second magnetic field sensitive area and the third magnetic field sensitive area are all composed of magnetic tunnel junctions connected in series, in parallel or in combination of series and parallel; the magnetic tunnel junction located in the first magnetic field sensitive area has a pinning direction along the first direction, and the magnetic tunnel junction located in the second magnetic field sensitive area has a pinning direction along the second direction; the third magnetic field sensitive area is arranged at a position corresponding to the magnetic field steering element on the plane of the substrate, and the magnetic tunnel junction located in the third magnetic field sensitive area has a pinning direction along the first direction / the second direction; The first direction, the second direction and the third direction are perpendicular to each other, and the third direction is also perpendicular to the plane of the substrate.

2. The three-axis magnetic sensor according to claim 1, characterized in that: The magnetic field deflection member comprises a seed layer, a nickel-iron layer and a cap layer which are stacked in sequence.

3. The three-axis magnetic sensor according to claim 1, characterized in that: The substrate comprises a substrate, an inclined structural layer and a dielectric layer which are stacked in sequence, the magnetic field steering element is arranged on the inclined surface of the inclined structural layer, the inclined surface of the inclined structural layer is inclined between a third direction and a first direction / a second direction, and the magnetic tunnel junction is arranged on the plane of the dielectric layer.

4. The three-axis magnetic sensor according to claim 3, characterized in that: The inclination angle of the inclined surface of the inclined structural layer is 15 degrees to 85 degrees.

5. The three-axis magnetic sensor according to any one of claims 1 to 4, characterized in that: The magnetic field steering element includes a first soft magnet and a second soft magnet arranged in mirror symmetry; the magnetic tunnel junction located in the third magnetic field sensitive area includes a plurality of first magnetic tunnel junctions arranged close to the first soft magnet and a plurality of second magnetic tunnel junctions arranged close to the second soft magnet, and the first magnetic tunnel junctions and the second magnetic tunnel junctions are arranged in mirror symmetry one by one; The first soft magnet and the second soft magnet cause the magnetic field in the external third direction to be distorted to produce a component perpendicular to the third direction, so as to constitute a magnetic field to be detected in the third magnetic field sensitive area; at least part of the first magnetic tunnel junction and the second magnetic tunnel junction has a first sensitivity direction, the first magnetic tunnel junctions with the first sensitivity direction are connected in series and / or in parallel to form a plurality of first magnetoresistance units, the second magnetic tunnel junctions with the first sensitivity direction are connected in series and / or in parallel to form a plurality of second magnetoresistance units, and the first magnetoresistance unit and the second magnetoresistance unit include an equal number of magnetic tunnel junctions.

6. The three-axis magnetic sensor according to claim 5, characterized in that: The first magnetoresistance unit includes a first magnetoresistance unit R31 formed by a plurality of the first magnetic tunnel junctions connected in series and / or in parallel outside the first soft magnetic body, and the second magnetoresistance unit includes a second magnetoresistance unit R34 formed by a plurality of the second magnetic tunnel junctions connected in series and / or in parallel outside the second soft magnetic body; and / or, The first magnetoresistance unit includes a first magnetoresistance unit R32 formed by a plurality of the first magnetic tunnel junctions connected in series and / or in parallel and located inside the first soft magnetic body, and the second magnetoresistance unit includes a second magnetoresistance unit R33 formed by a plurality of the second magnetic tunnel junctions connected in series and / or in parallel and located inside the second soft magnetic body.

7. The three-axis magnetic sensor according to claim 6, characterized in that: The first magnetic resistance unit R31 and the second magnetic resistance unit R34 are connected to form a Z-axis bridge; or, The first magnetic resistance unit R32 and the second magnetic resistance unit R33 are connected to form a Z-axis bridge; or, The first magnetoresistance unit R31 , the first magnetoresistance unit R32 , the second magnetoresistance unit R33 and the second magnetoresistance unit R34 are connected to form a Z-axis bridge.

8. The three-axis magnetic sensor according to claim 6, characterized in that: At least part of the first magnetic tunnel junction and the second magnetic tunnel junction has a second sensitivity direction, and the first sensitivity direction and the second sensitivity direction are opposite to each other; the first magnetic tunnel junctions with the second sensitivity direction are connected in series and / or in parallel to form a plurality of third magnetoresistance units, and the second magnetic tunnel junctions with the second sensitivity direction are connected in series and / or in parallel to form a plurality of fourth magnetoresistance units, and the first magnetoresistance unit, the second magnetoresistance unit, the third magnetoresistance unit and the fourth magnetoresistance unit include an equal number of magnetic tunnel junctions.

9. The three-axis magnetic sensor according to claim 8, characterized in that: The third magnetoresistance unit includes a third magnetoresistance unit R33' formed by a plurality of first magnetic tunnel junctions connected in series and / or in parallel located inside the first soft magnetic body, and the fourth magnetoresistance unit includes a fourth magnetoresistance unit R32' formed by a plurality of second magnetic tunnel junctions connected in series and / or in parallel located inside the second soft magnetic body; and / or, the third magnetoresistance unit includes a third magnetoresistance unit R34' formed by a plurality of first magnetic tunnel junctions connected in series and / or in parallel located outside the first soft magnetic body, and the fourth magnetoresistance unit includes a fourth magnetoresistance unit R31' formed by a plurality of second magnetic tunnel junctions connected in series and / or in parallel located outside the second soft magnetic body.

10. The three-axis magnetic sensor according to claim 9, characterized in that: The first magnetoresistance unit R31, the second magnetoresistance unit R34, the third magnetoresistance unit R34' and the fourth magnetoresistance unit R31' are connected to form a Z-axis bridge; or, The first magnetoresistance unit R32, the second magnetoresistance unit R33, the third magnetoresistance unit R33' and the fourth magnetoresistance unit R32' are connected to form a Z-axis bridge; or, The first magnetoresistance unit R31, the first magnetoresistance unit R32, the second magnetoresistance unit R33, the second magnetoresistance unit R34, the third magnetoresistance unit R34', the third magnetoresistance unit R33', the fourth magnetoresistance unit R32' and the fourth magnetoresistance unit R31' are connected to form a Z-axis bridge.

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