Three-axis magnetic sensor and manufacturing method therefor

Abstract

A three-axis magnetic sensor and a manufacturing method therefor. The three-axis magnetic sensor comprises: a substrate (110), in which a magnetic field steering member (180) is provided, wherein the magnetic field steering member (180) is inclined between a third direction and a first / second direction, and is used for steering a magnetic field in the third direction such that the magnetic field has a magnetic field component in the first / second direction; and first magnetic field sensitive regions (120), second magnetic field sensitive regions (130) and third magnetic field sensitive regions (140), which are arranged on the plane of the substrate (110), and are all formed by magnetic tunnel junctions (150) connected in series, in parallel, or in a combination of series and parallel, wherein the magnetic tunnel junctions (150) located in the first magnetic field sensitive regions (120) have a pinning direction in the first direction, the magnetic tunnel junctions (150) located in the second magnetic field sensitive regions (130) have a pinning direction in the second direction, the third magnetic field sensitive regions (140) are arranged on the plane of the substrate (110) at a position corresponding to the magnetic field steering member (180), and the magnetic tunnel junctions (150) located in the third magnetic field sensitive regions (140) have a pinning direction in the first / second direction.

Description

Tri-axial magnetic sensor and method of manufacturing the same

[0001] The present application claims priority to the Chinese patent application No. 202410673916.7, filed on May 28, 2024, and entitled "Tri-axial magnetic sensor and method of manufacturing the same", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the technical field of magnetic field sensing devices, and in particular to a tri-axial magnetic sensor and a method of manufacturing the same. BACKGROUND

[0003] With the development of technology and the continuous progress of society, more and more types of magnetic sensors appear in people's daily work and life. TMR (Tunnel Magnetoresistance Effect) magnetic sensor is a kind of magnetic sensitive element using tunnel magnetoresistance effect, which can detect external magnetic field by using the resistance change of TMR magnetic resistance element caused by external magnetic field. However, the TMR magnetic resistance element can only perform in-plane magnetic field sensing.

[0004] In order to enable the TMR magnetic resistance element to detect out-of-plane magnetic field, the conventional magnetic sensor usually needs to deposit TMR magnetic thin film on a slope, and then etch the TMR magnetic thin film on the slope to form a magnetic tunnel junction. The deposition and etching of TMR magnetic thin film on the slope are complex processes, and there is a disadvantage of low production yield. SUMMARY

[0005] According to various embodiments of the present application, a tri-axial magnetic sensor and a method of manufacturing the same are provided.

[0006] A tri-axial magnetic sensor, comprising:

[0007] a substrate, the substrate being built-in with a magnetic field turning piece, the magnetic field turning piece being inclined between a third direction and a first direction / second direction, for turning the magnetic field of the third direction to have a magnetic field component of the first direction / second direction;

[0008] A first magnetic field sensitive region, a second magnetic field sensitive region and a third magnetic field sensitive region are arranged on the plane of the substrate, and each of the first magnetic field sensitive region, the second magnetic field sensitive region and the third magnetic field sensitive region is composed of magnetic tunnel junctions in series, in parallel or in series and parallel combination; the magnetic tunnel junctions in the first magnetic field sensitive region have pinning directions along the first direction, the magnetic tunnel junctions in the second magnetic field sensitive region have pinning directions along the second direction; the third magnetic field sensitive region is arranged on the plane of the substrate at a position corresponding to the magnetic field turning piece, and the magnetic tunnel junctions in the third magnetic field sensitive region have pinning directions along the first direction / second direction.

[0009] 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.

[0010] A preparation method of a three-axis magnetic sensor, comprising:

[0011] A substrate is provided, and the substrate is internally provided with a magnetic field turning piece, the magnetic field turning piece is inclined between the third direction and the first direction / second direction, and is used for turning the magnetic field in the third direction to have a magnetic field component in the first direction / second direction;

[0012] Magnetic tunnel junctions are formed on the substrate; a first magnetic field sensitive region, a second magnetic field sensitive region and a third magnetic field sensitive region are arranged on the plane of the substrate, and each of the first magnetic field sensitive region, the second magnetic field sensitive region and the third magnetic field sensitive region is composed of magnetic tunnel junctions in series, in parallel or in series and parallel combination; the magnetic tunnel junctions in the first magnetic field sensitive region have pinning directions along the first direction, the magnetic tunnel junctions in the second magnetic field sensitive region have pinning directions along the second direction; the third magnetic field sensitive region is arranged on the plane of the substrate at a position corresponding to the magnetic field turning piece, and the magnetic tunnel junctions in the third magnetic field sensitive region have pinning directions along the first direction / second direction;

[0013] 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.

[0014] The details of one or more embodiments of the present application are presented in the following drawings and description. Other features, objects and advantages of the present application will become apparent from the description, drawings and claims. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the accompanying drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, the accompanying drawings in the following description only only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative labor on the basis of these drawings.

[0016] Fig. 1 is a schematic diagram of the structure of a three-axis magnetic sensor in an embodiment;

[0017] Fig. 2 is a schematic diagram of the cross-sectional structure of a first magnetic field sensitive region of the three-axis magnetic sensor in Fig. 1 along A-A';

[0018] Fig. 3 is a schematic diagram of the cross-sectional structure of a second magnetic field sensitive region of the three-axis magnetic sensor in Fig. 1 along B-B';

[0019] Fig. 4 is a schematic diagram of the cross-sectional structure of a third magnetic field sensitive region of the three-axis magnetic sensor in Fig. 1 along B-B';

[0020] Fig. 5 is another schematic diagram of the cross-sectional structure of the third magnetic field sensitive region of the three-axis magnetic sensor in Fig. 1 along B-B';

[0021] Fig. 6 is an equivalent circuit diagram of an X-axis magnetic tunnel junction array forming an electric bridge in an embodiment;

[0022] Fig. 7 is a schematic diagram of the distribution and circuit connection of an X-axis magnetic tunnel junction array in an embodiment;

[0023] Fig. 8 is an equivalent circuit diagram of a Y-axis magnetic tunnel junction array forming an electric bridge in an embodiment;

[0024] Fig. 9 is a schematic diagram of the distribution and circuit connection of a Y-axis magnetic tunnel junction array in an embodiment;

[0025] Fig. 10 and Fig. 11 are schematic diagrams of the principle of a Z-axis magnetic tunnel junction forming an electric bridge in an embodiment;

[0026] Fig. 12 and Fig. 13 are schematic diagrams of the principle of a Z-axis magnetic tunnel junction forming an electric bridge in another embodiment;

[0027] Fig. 14 and Fig. 15 are schematic diagrams of the principle of a Z-axis magnetic tunnel junction forming an electric bridge in yet another embodiment;

[0028] Fig. 16 is a schematic diagram of the structure of a Z-axis magnetic tunnel junction forming a magnetic resistance unit in an embodiment;

[0029] Fig. 17 is an equivalent circuit diagram of a Z-axis magnetic tunnel junction forming an electric bridge in an embodiment;

[0030] Fig. 18 is a schematic diagram of the distribution and circuit connection of a Z-axis magnetic tunnel junction array in an embodiment;

[0031] Fig. 19 is an equivalent circuit diagram of a bridge composed of Z-axis magnetic tunnel junctions in another embodiment;

[0032] Fig. 20 is a distribution and circuit connection diagram of a Z-axis magnetic tunnel junction array in another embodiment;

[0033] Fig. 21 is a schematic diagram of a principle of changing a magnetic field direction by using a magnetic field turning piece in an embodiment;

[0034] Fig. 22 is a schematic diagram of a structure of a Z-axis magnetic tunnel junction forming a magnetoresistance unit in another embodiment;

[0035] Figs. 23 to 38 are schematic diagrams of a structure of a preparation process of a three-axis magnetic sensor in an embodiment. DETAILED DESCRIPTION

[0036] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not used to limit the present application.

[0037] In an embodiment, as shown in Figs. 1 to 4, 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 a plane of the substrate 110, the substrate 110 being internally provided with a magnetic field turning piece 180, the magnetic field turning piece 180 being inclined between a third direction and a first direction / second direction, and being used to turn a magnetic field of the third direction so as to have a magnetic field component of the first direction / 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 in a way of series connection, parallel connection or combination of series connection and parallel connection; the magnetic tunnel junctions 150 located in the first magnetic field sensitive area 120 have a pinning direction along the first direction, the magnetic tunnel junctions 120 located in the second magnetic field sensitive area 130 have a pinning direction along the second direction; the third magnetic field sensitive area 140 is arranged at a position corresponding to the magnetic field turning piece 180 on the plane of the substrate 110, and the magnetic tunnel junctions 150 located in the third magnetic field sensitive area 140 have a pinning direction along the first direction / second direction. Wherein, 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.

[0038] Specifically, the first direction and the second direction can be respectively an X-axis direction and a Y-axis direction, or can be respectively a Y-axis direction and an X-axis direction, and the third direction is a Z-axis direction, and the plane of the substrate 110 is an X-Y plane. For the convenience of understanding, the following will be described by taking the first direction, the second direction and the third direction as the X-axis direction, the Y-axis direction and the Z-axis direction respectively as an example.

[0039] The magnetic tunnel junction 150 generally includes a free layer / tunnel barrier layer / pinned layer, and a change in an external magnetic field can cause a change in the magnetization direction of the free layer. When the magnetization direction of the free layer is 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. As can be seen, the 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 of the magnetic tunnel junction 150. By connecting the magnetic tunnel junction 150 in series or in parallel or in combination of series and parallel, an electrical signal corresponding to the component of the external magnetic field in the pinning direction can be output.

[0040] The magnetic tunnel junction 150 of the first magnetic field sensitive area 120 is arranged on the plane of the substrate 110 and has a pinning direction along the X-axis direction, so that the first magnetic field sensitive area 120 can be used to detect the magnetic field in the X-axis direction.

[0041] The magnetic tunnel junction 150 of the second magnetic field sensitive area 130 is arranged on the plane of the substrate 110 and has a pinning direction along the Y-axis direction, so that the second magnetic field sensitive area 130 can be used to detect the magnetic field in the Y-axis direction.

[0042] The specific pinning direction of the magnetic tunnel junction 150 in the third magnetic field sensitive area 140 corresponds to the inclination direction of the magnetic field turning piece 180. If the magnetic field turning piece 180 is inclined between the Z-axis direction and the X-axis direction to turn the magnetic field in the Z-axis direction to have a magnetic field component in the X-axis direction, the magnetic tunnel junction 150 of the third magnetic field sensitive area 140 has a pinning direction along the X-axis direction. If the magnetic field turning piece 180 is inclined between the Z-axis direction and the Y-axis direction to turn the magnetic field in the Z-axis direction to have a magnetic field component in the Y-axis direction, the magnetic tunnel junction 150 of the third magnetic field sensitive area 140 has a pinning direction along the Y-axis direction. Thus, the combination of the magnetic field turning piece 180 and the third magnetic field sensitive area 140 can be used to detect the magnetic field in the Z-axis direction.

[0043] By embedding the magnetic field turning piece 180 in the substrate 110, the magnetic field in the corresponding direction can be detected by arranging the first magnetic field sensitive area 120, the second magnetic field sensitive area 130 and the third magnetic field sensitive area 140 on the plane of the substrate 110, to realize the detection of the three-axis magnetic field. All the 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.

[0044] In one embodiment, the substrate 110 comprises a substrate 112, a tilted structure layer 114 and a medium layer 116 which are sequentially stacked, the magnetic field turning piece 180 is arranged on the inclined surface of the tilted structure layer 114, the inclined surface of the tilted structure layer 114 is inclined between the third direction and the first direction / second direction, and the magnetic tunnel junction 150 is arranged on the plane of the medium layer 116, so that the magnetic tunnel junction 150 is located above the magnetic field turning piece 180. It can be understood that in other embodiments, the magnetic tunnel junction 150 can also be located below the magnetic field turning piece 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 arranged on the upper surface of the substrate 112.

[0045] The material of the tilted structure layer 114 can be silicon oxide (SiO x The tilted structure layer 114 can be designed with a tilted structure, and the magnetic field turning piece 180 can be generated on the inclined surface of the tilted structure, so that the manufacturing process is simple. The tilted structure can be a groove or a protrusion, and the inclined surface of the tilted structure is the inclined surface of the groove or the inclined surface of the protrusion. As shown in FIGS. 4 and 5, the magnetic field turning piece 180 can be located entirely on the inclined surface of the tilted structure, or can be located mostly on the inclined surface of the tilted structure, and the remaining part extends to the top of the tilted structure. The magnetic tunnel junction 150 of the third magnetic field sensitive area 140 is located on the plane of the medium layer 116 close to the magnetic field turning piece 180, and can be arranged on both sides of the top of the magnetic field turning piece 180. For example, as shown in FIGS. 4 and 5, the magnetic tunnel junction 150 of the third magnetic field sensitive area 140 can be arranged on the left side and / or the right side of the top of the magnetic field turning piece 180, as long as the magnetic tunnel junction 150 is not located directly opposite the top of the magnetic field turning piece 180. As shown in FIG. 21, the top of the magnetic field turning piece 180 does not have a turning effect on the external magnetic field in the Z-axis direction, so arranging the magnetic tunnel junction 150 on both sides of the top of the magnetic field turning piece 180 can avoid the situation that the magnetic field converted by the magnetic field turning piece 180 cannot be detected.

[0046] The inclination angle of the inclined surface of the tilted structure layer 114 is not unique and can be set according to actual needs. If the inclination angle is too small, it is closer to parallel to the horizontal plane, and the turning effect on the out-of-plane magnetic field is weaker. If the inclination angle is too large, it is closer to perpendicular to the horizontal plane, which increases the process difficulty on the one hand, and is not conducive to the deposition of the magnetic field turning piece 114 on the other hand, which is not conducive to the formation of a relatively thick magnetic field turning piece 114, thereby affecting the turning effect. Therefore, in the present embodiment, the inclination angle of the inclined surface of the tilted structure layer 114 can be designed to be 15 degrees-85 degrees, and preferably can be designed to be 20 degrees-80 degrees.

[0047] The thickness of the tilted structure layer 114 is 3-5 microns, and a certain thickness is beneficial to the formation of the tilted structure.

[0048] The substrate 112 can include a CMOS wafer layer and a CMOS signal layer disposed on the CMOS wafer layer. The CMOS wafer layer has integrated circuits composed of a plurality of MOS tubes, which can process analog signals generated by the first magnetic field sensitive area 120, the second magnetic field sensitive area 130 and the third magnetic field sensitive area 140 in response to an external magnetic field to obtain digital signals. The CMOS signal layer can realize functions such as receiving analog signals and outputting digital signals. Further, the CMOS signal layer can be at least partially disposed in the form of a coil, which can serve as a self-checking coil to generate a self-checking magnetic field to check whether the sensor functions normally, or 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 in 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. The metal layer can be a copper layer, an aluminum layer, a copper alloy layer or an aluminum alloy layer. The substrate 112 integrated with the CMOS wafer layer and the CMOS signal layer enables the triaxial magnetic sensor to no longer need to additionally integrate a chip for signal processing, which is conducive to reducing the packaging size of the triaxial magnetic sensor.

[0049] Further, the substrate 112 can further include a protective layer disposed on the CMOS signal layer to protect the CMOS signal layer. The material of the protective layer can be silicon oxide (SiO x ), silicon nitride (SiN x ) or aluminum oxide (AlO x ), etc.

[0050] The medium layer 116 can be a single-layer or multi-layer medium layer structure. In this embodiment, the medium layer 116 includes a first medium layer and a second medium layer. The first medium layer is located between the inclined structure layer 114 and the second medium layer, and the array of the magnetic tunnel junction 150 is arranged on the plane of the second medium layer. The material of the first medium layer can be silicon nitride (SiN x ), and the material of the second medium layer can be silicon oxide (SiO x ) or aluminum oxide (AlO x ) with relatively low hardness, which is conducive to chemical mechanical polishing (CMP) to make the second medium layer have a flat surface, and finally form the magnetic tunnel junction 150 on the second medium layer with a flat surface.

[0051] In one embodiment, the magnetic tunnel junction 150 in the first magnetic field sensitive area 120, the second magnetic field sensitive area 130 and the third magnetic field sensitive area 140 can all be arranged in an array on the plane of the medium layer 116. The array arrangement can make the layout more compact, which is conducive to reducing the packaging size of the triaxial magnetic sensor and facilitating electrical connection between the magnetic tunnel junctions 150.

[0052] In one embodiment, the magnetic field turning piece 180 comprises a seed layer, a nickel-iron (NiFe) layer and a cap layer which are sequentially stacked. The material of the seed layer can be tantalum (Ta) or ruthenium (Ru). The material of the cap layer can be titanium nitride (TiN x ) or tantalum nitride (TaN x ), which protects the nickel-iron (NiFe) layer.

[0053] In one embodiment, as shown in FIGS. 2-4, the tri-axial magnetic sensor further comprises an insulating layer 170, which can be made of silicon oxide (SiO x ) or aluminum oxide (AlO x ), etc. The insulating layer 170 covers the magnetic tunnel junction 150, which insulates and protects the magnetic tunnel junction 150.

[0054] In one embodiment, as shown in FIG. 1, the tri-axial magnetic sensor further comprises a coil 160 disposed on the substrate 110. The coil 160 is a multi-turn planar coil, which is used to reset each magnetic tunnel junction 150 in the first magnetic field sensitive region 120, the second magnetic field sensitive region 130 and the third magnetic field sensitive region 140 when energized, thereby reducing the noise of the magnetic sensor, improving the detection accuracy, and reducing the cross-axis interference and hysteresis.

[0055] Specifically, the part of the coil 160 along the X-axis direction for transmitting current is disposed corresponding to the first magnetic field sensitive region 120; the part of the coil 160 along the Y-axis direction for transmitting current is disposed corresponding to the second magnetic field sensitive region 130. When energized, the coil 160 can generate a magnetic field perpendicular to the direction of the current, that is, the part of the coil 160 along the X-axis direction for transmitting current can generate a magnetic field along the Y-axis direction, which resets the magnetization direction of the free layer of the magnetic tunnel junction 140 in the first magnetic field sensitive region 120, so that the magnetization direction is along the Y-axis direction; the part of the coil 160 along the Y-axis direction for transmitting current can generate a magnetic field along the X-axis direction, which resets the magnetization direction of the free layer of the magnetic tunnel junction 140 in the second magnetic field sensitive region 130, so that the magnetization direction is along the X-axis direction.

[0056] The distribution of the third magnetic field sensitive region 140 is different according to the inclination of the magnetic field turning piece 180. When the magnetic field turning piece 180 is inclined between the Z-axis direction and the X-axis direction, the third magnetic field sensitive region 140 can be disposed on the part of the coil 160 along the X-axis direction for transmitting current (i.e., close to the first magnetic field sensitive region 120) and corresponding to the position of the magnetic field turning piece 180; when the magnetic field turning piece 180 is inclined between the Z-axis direction and the Y-axis direction, the third magnetic field sensitive region 140 can be disposed on the part of the coil 160 along the Y-axis direction for transmitting current (i.e., close to the second magnetic field sensitive region 130) and corresponding to the position of the magnetic field turning piece 180.

[0057] For example, the magnetic field diverting piece 180 is inclined between the Z-axis direction and the Y-axis direction, as shown in FIG. 1, the current in the coil 160 can be clockwise or counterclockwise. And since the coil 160 is a planar coil composed of multiple turns of wire, the two parts of the coil 160 arranged opposite along the Y-axis direction have current transmitted along the X-axis direction, and the two parts of the coil 160 arranged opposite along the X-axis direction have current transmitted along the Y-axis direction. In combination with the above-mentioned corresponding relationship between the first magnetic field sensitive area 120, the second magnetic field sensitive area 130, the third magnetic field sensitive area 140 and the current transmission direction 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 on which 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 on which the two first magnetic field sensitive areas 120 are located. In this way, the part of the coil 160 transmitting current along the positive direction (+X) of the X-axis and the part of the coil 160 transmitting current along the negative direction (-X) of the X-axis correspond to one first magnetic field sensitive area 120 respectively, and the part of the coil 160 transmitting current along the positive direction (+Y) of the Y-axis and the part of the coil 160 transmitting current along the negative direction (-Y) of the Y-axis correspond to one second magnetic field sensitive area 130 and one third magnetic field sensitive area 140 respectively. After arranging the coil 160 on the substrate 110, energizing the coil 160 will generate a magnetic field component perpendicular to the current direction. The magnetic field component generated by the coil 160 generates a magnetic field in the positive and negative directions of the Y-axis in the first magnetic field sensitive area 120, and generates a magnetic field in the positive and negative directions of the X-axis in the second magnetic field sensitive area 130 and the third magnetic field sensitive area 140. After energizing the coil 160, the reset operation of the magnetic tunnel junction 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 performed by using the parts with different current directions, and the initial magnetization direction of the free layer of the magnetic tunnel junction 150 is determined, which is simple and fast.

[0058] It can be understood that in other embodiments, if the magnetic field diverting piece 180 is inclined between the Z-axis direction and the X-axis direction, then 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 distributed on both sides of the axis on which 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 distributed on both sides of the axis on which the two second magnetic field sensitive areas 130 are located.

[0059] The coil 160 can 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 can be used as the coil 160. When the coil 160 is arranged above the magnetic tunnel junction 150, a metal layer can be formed on the insulating layer 170 and etched to form the coil 160. Further, the insulating layer 170 can also have a multi-layer structure, and the coil 160 can also be wrapped by the layers to provide protection.

[0060] As shown in FIG. 6 and FIG. 7, the hollow arrows in FIG. 6 represent the pinning directions of the magnetic tunnel junction 150, the solid arrows represent the initial magnetization directions of the free layer of the magnetic tunnel junction 150, and the hollow arrows in FIG. 7 represent the current directions in the coil 160. The magnetic tunnel junction 150 located in the first magnetic field sensitive area 120 has a part with a pinning direction in the positive direction (+X) along the X-axis and another part with a pinning direction in the negative direction (-X) along the X-axis. The magnetic tunnel junction 150 with the pinning direction in the positive direction along the X-axis is partially connected in series to form the magnetic resistance unit R11 and partially connected in series to form the magnetic resistance unit R13; the magnetic tunnel junction 150 with the pinning direction in the negative direction along the X-axis is partially connected in series to form the magnetic resistance unit R12 and partially connected in series to form the magnetic resistance unit R14. The magnetic tunnel junction 150 included in the magnetic resistance unit R11, the magnetic resistance unit R12, the magnetic resistance unit R13, and the magnetic resistance unit R14 has the same number. The pinning direction of the magnetic tunnel junction 150 can be determined by an annealing magnetic field. Specifically, the magnetic tunnel junction 150 constituting the magnetic resistance unit R11 and the magnetic resistance unit R13 is annealed in the positive direction along the X-axis, and the magnetic tunnel junction 150 constituting the magnetic resistance unit R12 and the magnetic resistance unit R14 is annealed in the negative direction along the X-axis. The magnetic tunnel junction 150 that needs to be annealed in the same direction can be arranged in the same area, for example, the magnetic tunnel junction 150 constituting the magnetic resistance unit R11 and the magnetic resistance unit R13 is arranged in the same area, and the magnetic tunnel junction 150 constituting the magnetic resistance unit R12 and the magnetic resistance unit R14 is arranged in another same area. The magnetic tunnel junction 150 that needs to be annealed in different directions can also be arranged in the same area based on other requirements, for example, for the convenience of circuit connection or magnetic reset between the magnetic resistance units, for example, the magnetic tunnel junction 150 constituting the magnetic resistance unit R11 and the magnetic resistance unit R14 is arranged in the same area, and the magnetic tunnel junction 150 constituting the magnetic resistance unit R12 and the magnetic resistance unit R13 is arranged in another same area. When the same area needs to be annealed in different directions, local laser annealing can be used.

[0061] The magnetoresistance units R11 and R14 have the free layer initial magnetization direction along the positive direction of the Y axis, and the magnetoresistance units R12 and R13 have the free layer initial magnetization direction along the negative direction of the Y axis. By arranging the magnetic tunnel junction 150 constituting the magnetoresistance units R11 and R14 in the portion where the coil 160 transmits current along the positive direction (+X) of the X axis, and arranging the magnetic tunnel junction 140 constituting the magnetoresistance units R12 and R13 in the portion where the coil 160 transmits current along the negative direction (-X) of the X axis, the magnetization direction of the free layer of the magnetic tunnel junction 150 of the first magnetic field sensitive area 120 can be reset correspondingly when the coil 160 is energized.

[0062] 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.

[0063] When the external magnetic field has a component along the X axis direction during the operation of the sensor, the magnetization direction of the free layer of the magnetic tunnel junction 150 rotates by different angles according to the size of the magnetic field component, so that the resistance of the magnetoresistance unit R11 / magnetoresistance unit R13 increases or decreases. The resistance change of the magnetoresistance unit R12 / magnetoresistance unit R14 is opposite to the resistance change direction of the magnetoresistance unit R11 / magnetoresistance unit R13, and the change size is equal. The differential signal S1 of the X axis bridge has an approximately linear change relationship with the X axis component of the external magnetic field, as follows:

[0064] where MR and H k represent the intrinsic properties of the magnetic tunnel junction 150, and are the magnetic resistance and the anisotropy field, respectively; V P1 represents the output signal of the 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.

[0065] As shown in FIG. 8 and FIG. 9, the hollow arrows in FIG. 8 represent the pinning directions of the magnetic tunnel junctions 150, the solid arrows represent the initial magnetization directions of the free layers of the magnetic tunnel junctions 150, and the hollow arrows in FIG. 9 represent the current directions in the coil 160. The magnetic tunnel junctions 150 located in the second magnetic field sensitive area 130 have a part with the pinning direction in the positive direction (+Y) along the Y axis and another part with the pinning direction in the negative direction (-Y) along the Y axis. The magnetic tunnel junctions 150 with the pinning direction in the positive direction along the Y axis are connected in series to form a part of the magnetic resistance unit R21 and another part of the magnetic resistance unit R23; the magnetic tunnel junctions 150 with the pinning direction in the negative direction along the Y axis are connected in series to form a part of the magnetic resistance unit R22 and another part of the magnetic resistance unit R24. The magnetic resistance unit R21, the magnetic resistance unit R22, the magnetic resistance unit R23 and the magnetic resistance unit R24 contain the same number of magnetic tunnel junctions 150. The pinning direction of the magnetic tunnel junction 150 can be determined by an annealing magnetic field. The magnetic tunnel junctions 150 constituting the magnetic resistance unit R21 and the magnetic resistance unit R23 are annealed in the positive direction along the Y axis, and the magnetic tunnel junctions 150 constituting the magnetic resistance unit R22 and the magnetic resistance unit R24 are annealed in the negative direction along the Y axis.

[0066] The magnetic resistance unit R23 and the magnetic resistance unit R24 have the initial magnetization direction of the free layer in the positive direction along the X axis, and the magnetic resistance unit R21 and the magnetic resistance unit R22 have the initial magnetization direction of the free layer in the negative direction along the X axis. By arranging the magnetic tunnel junctions 150 constituting the magnetic resistance unit R23 and the magnetic resistance unit R24 in the part of the coil 160 transmitting current in the negative direction (-Y) along the Y axis, and arranging the magnetic tunnel junctions 150 constituting the magnetic resistance unit R21 and the magnetic resistance unit R22 in the part of the coil 160 transmitting current in the positive direction (+Y) along the Y axis, the magnetization direction of the free layer of the magnetic tunnel junction 150 in the second magnetic field sensitive area 130 can be reset when the coil 160 is energized.

[0067] One end of the magnetic resistance unit R21 is connected to the output terminal P2, the other end of the magnetic resistance unit R21 is connected to the power supply terminal VCC2, one end of the magnetic resistance unit R22 is connected to the output terminal N2, and the other end of the magnetic resistance unit R22 is connected to the power supply terminal VCC2; one end of the magnetic resistance unit R24 is connected to the output terminal P2, the other end of the magnetic resistance unit R24 is connected to the ground terminal GND, one end of the magnetic resistance unit R23 is connected to the output terminal N2, and the other end of the magnetic resistance unit R23 is connected to the ground terminal GND.

[0068] When the sensor works, 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 with the size of the magnetic field component, so that the resistance of the magnetoresistance unit R21 / magnetoresistance unit R23 becomes larger or smaller. The resistance change of the magnetoresistance unit R22 / magnetoresistance unit R24 is opposite to the resistance change direction of the magnetoresistance unit R21 / magnetoresistance unit R23, and the change size is equal. The differential signal S2 of the Y-axis bridge has an approximately linear change relationship with the Y-axis component of the external magnetic field, as follows:

[0069] Wherein, MR and H k represent the intrinsic properties of the magnetic tunnel junction 150, which are the magnetic resistance and the anisotropy field, respectively; V P2 represents the output signal of the output end P2, V N2 represents the output signal of the output end N2; Hy represents the Y-axis component of the external magnetic field.

[0070] The magnetic tunnel junction 150 in the third magnetic field sensitive area 140 forms a magnetoresistance unit, and the way of connecting the magnetoresistance unit to form a Z-axis bridge for magnetic field detection is not unique.

[0071] In one embodiment, as shown in FIGS. 10-15, the magnetic field turning piece 180 includes a first soft magnetic body 182 and a second soft magnetic body 184 which are mirror-symmetrically arranged; in the magnetic tunnel junction 150 located in the third magnetic field sensitive area 140, a plurality of first magnetic tunnel junctions arranged close to the first soft magnetic body 182 and a plurality of second magnetic tunnel junctions arranged close to the second soft magnetic body 184 are mirror-symmetrically arranged one by one. The first soft magnetic body 182 and the second soft magnetic body 184 distort the external Z-axis direction magnetic field, so that it generates a component perpendicular to the Z-axis direction (for example, the X-axis direction or the Y-axis direction), to constitute the to-be-detected magnetic field of the third magnetic field sensitive area 140. At least part of the first magnetic tunnel junctions and the second magnetic tunnel junctions have 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 number of magnetic tunnel junctions 150 included in the first magnetoresistance units and the second magnetoresistance units is equal. 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.

[0072] As shown in FIG. 10, when the symmetry plane of the mirror image symmetry of the first soft magnet 182 and the second soft magnet 184 is consistent with the symmetry plane of the mirror image symmetry of the first magnetic tunnel junction and the second magnetic tunnel junction, under the turning action of the first soft magnet 182 and the second soft magnet 184, the magnetic field directions of the to-be-detected magnetic field at the positions of the first magnetic tunnel junction and the second magnetic tunnel junction are opposite, and the magnetic field sizes are equal, that is, the magnetic field directions of the to-be-detected magnetic field at the positions of the first magnetic resistance unit and the second magnetic resistance unit are opposite, and the magnetic field sizes are equal. Because the sensitivity directions of the first magnetic tunnel junction constituting the first magnetic resistance unit and the second magnetic tunnel junction constituting the second magnetic resistance unit are both the first sensitivity direction, under the action of the to-be-detected magnetic field, the resistance of the first magnetic resistance unit becomes larger or smaller, and the resistance of the second magnetic resistance unit changes in the opposite direction and has the same size as the resistance of the first magnetic resistance unit. In this way, the first magnetic resistance unit and the second magnetic resistance unit can be connected to constitute a Z-axis bridge to detect the magnetic field converted by the magnetic field turning piece 180, thereby realizing detection of the external Z-axis direction magnetic field. Because the magnetic tunnel junctions constituting the first magnetic resistance unit and the second magnetic resistance unit both have the first sensitivity direction, that is, the same pinning direction, the same direction of the annealing magnetic field can be used, which is beneficial to simplify the preparation process.

[0073] In the embodiment, the substrate 110 can be designed to have a plurality of inclined structures, and the first soft magnet 182 and the second soft magnet 184 can be arranged on the inclined structures. In the embodiment, the inclined structures can be designed to include a first inclined surface and a second inclined surface arranged in mirror image symmetry, and the first soft magnet 182 and the second soft magnet 184 can be arranged on the first inclined surface and the second inclined surface respectively, so that the first soft magnet 182 and the second soft magnet 184 are arranged in mirror image symmetry. In addition, it can be understood that the inclined structure can be one or a plurality of structures with the same structure, and correspondingly, the first soft magnet 182 and the second soft magnet 184 can be arranged in one pair or a plurality of pairs based on the number of the inclined structures.

[0074] As shown in FIGS. 10, 12 and 14, the side of the first soft magnet 182 away from the second soft magnet 184 can be regarded 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 regarded 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 regarded 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 regarded as the outer side of the second soft magnet 184.

[0075] In one embodiment, as shown in FIG. 10 and FIG. 11, the first magnetoresistance unit includes a plurality of first magnetic tunnel junctions with the first sensitivity direction in series and / or in parallel to form the first magnetoresistance unit R31 outside the first soft magnetic body 182, the second magnetoresistance unit includes a plurality of second magnetic tunnel junctions with the first sensitivity direction in series and / or in parallel to form the second magnetoresistance unit R34 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 shown in FIG. 11, one first magnetoresistance unit R31 is connected to the output terminal N3 and the power supply terminal VCC3, and the free layer initial magnetization direction 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 free layer initial magnetization direction is the positive direction of the X-axis; one second magnetoresistance unit R34 is connected to the output terminal P3 and the power supply terminal VCC3, and the free layer initial magnetization direction is the negative direction of the X-axis; and another second magnetoresistance unit R34 is connected to the output terminal N3 and the ground terminal GND, and the free layer initial magnetization direction is the positive direction of the X-axis. As shown in FIG. 10 and FIG. 11, 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, 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 magnetic field sizes are equal, under the action of the magnetic field to be detected, the resistance of the first magnetoresistance unit R31 increases or decreases, 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 size is equal, the first magnetoresistance unit R31 and the second magnetoresistance unit R34 can form a Z-axis bridge, and the differential signal S3 of the Z-axis bridge has an approximately linear change relationship with the Z-axis component of the external magnetic field, as follows:

[0076] wherein MR and H k represent the intrinsic properties of the magnetic tunnel junction 150, and are the magnetic resistance and the anisotropy field, respectively; V P3 represents the output signal of the 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 proportion factor of the magnetic field size at the positions of 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 turning piece 150.

[0077] It should be noted that the component of the external magnetic field along the Y-axis direction is in the same direction at the positions of the first magnetic resistance unit R31 and the second magnetic resistance unit R34, and the pinning directions of the first magnetic tunnel junctions constituting the first magnetic resistance unit R31 and the second magnetic tunnel junctions constituting the second magnetic resistance unit R34 are both along the negative direction of the Y-axis direction, so the resistance changes caused by the component of the external magnetic field along the Y-axis direction are consistent, thereby making the Z-axis bridge have no signal output for the component of the external magnetic field along the Y-axis direction.

[0078] In one embodiment, as shown in FIGS. 12 and 13, the first magnetic resistance unit includes a plurality of first magnetic tunnel junctions with a first sensitivity direction in series and / or in parallel to form a first magnetic resistance unit R32 inside the first soft magnetic body 182, the second magnetic resistance unit includes a plurality of second magnetic tunnel junctions with a first sensitivity direction in series and / or in parallel to form a second magnetic resistance unit R33 inside the second soft magnetic body 184, and the first magnetic resistance unit R32 and the second magnetic resistance unit R33 are connected to constitute a Z-axis bridge. Specifically, as shown in FIG. 13, one first magnetic resistance unit R32 is connected between the output end N4 and the power supply end VCC4, and the initial magnetization direction of the free layer is the negative direction of the X-axis, and another first magnetic resistance unit R32 is connected between the output end P4 and the ground end GND, and the initial magnetization direction of the free layer is the positive direction of the X-axis; one second magnetic resistance unit R33 is connected between the output end P4 and the power supply end VCC4, and the initial magnetization direction of the free layer is the negative direction of the X-axis, and another second magnetic resistance unit R33 is connected between the output end N4 and the ground end GND, and the initial magnetization direction of the free layer is the positive direction of the X-axis. As shown in FIGS. 12 and 13, since the pinning directions of the first magnetic tunnel junctions constituting the first magnetic resistance unit R32 and the second magnetic tunnel junctions constituting the second magnetic resistance unit R33 are both along the negative direction of the Y-axis direction, and the magnetic field directions of the to-be-detected magnetic field at the positions of the first magnetic resistance unit R32 and the second magnetic resistance unit R33 are opposite and the magnetic field sizes are equal, under the action of the to-be-detected magnetic field, the resistance of the first magnetic resistance unit R32 increases or decreases, the resistance change of the second magnetic resistance unit R33 is opposite to that of the first magnetic resistance unit R32 in direction and equal in size, the first magnetic resistance unit R32 and the second magnetic resistance unit R33 can constitute a Z-axis bridge, and the differential signal S4 of the Z-axis bridge has an approximately linear change relationship with the Z-axis component of the external magnetic field, as follows:

[0079] wherein MR and H k represent the intrinsic properties of the magnetic tunnel junction 150, and are the magnetic resistance and the anisotropy field, respectively; V P4 represents the output signal of the output end P4, V N4represents the output signal of the output terminal N4; Hz represents the Z-axis component of the external magnetic field; γ2 represents the ratio of the Z-axis component of the external magnetic field after being twisted by the magnetic field turning piece 150 to the magnetic field size at the positions of the first magnetic resistance unit R32 and the second magnetic resistance unit R33.

[0080] In one embodiment, as shown in FIGS. 14 and 15, the first magnetic resistance unit includes a plurality of first magnetic tunnel junctions with a first sensitivity direction in series and / or in parallel to form a first magnetic resistance unit R31 located outside the first soft magnetic body 182, and a plurality of first magnetic tunnel junctions with the first sensitivity direction in series and / or in parallel to form a first magnetic resistance unit R32 located inside the first soft magnetic body 182; the second magnetic resistance unit includes a plurality of second magnetic tunnel junctions with the first sensitivity direction in series and / or in parallel to form a second magnetic resistance unit R33 located inside the second soft magnetic body, and a plurality of second magnetic tunnel junctions with the first sensitivity direction in series and / or in parallel to form a second magnetic resistance unit R34 located outside the second soft magnetic body; 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 are connected to form a Z-axis bridge. Specifically, as shown in FIG. 15, one first magnetic resistance unit R31 and one second magnetic resistance unit R33 are connected in series or in parallel to the output terminal N5 and the power supply terminal VCC5, and the initial magnetization directions of the free layers are both in the negative direction of the X-axis; another first magnetic resistance unit R31 and another second magnetic resistance unit R33 are connected in series or in parallel to the output terminal P5 and the ground terminal GND, and the initial magnetization directions of the free layers are both in the positive direction of the X-axis; one first magnetic resistance unit R32 and one second magnetic resistance unit R34 are connected in series or in parallel to the output terminal N5 and the ground terminal GND, and the initial magnetization directions of the free layers are both in the positive direction of the X-axis; another first magnetic resistance unit R32 and another second magnetic resistance unit R34 are connected in series or in parallel to the output terminal P5 and the power supply terminal VCC5, and the initial magnetization directions of the free layers are both in the negative direction of the X-axis. As shown in FIGS. 14 and 15, according to the pinning directions of the magnetic tunnel junctions 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, and the magnetic field directions and the magnetic field sizes of the to-be-detected magnetic field at the positions, under the action of the to-be-detected magnetic field, the resistance of the whole formed by the first magnetic resistance unit R31 and the second magnetic resistance unit R33 increases or decreases, and the resistance of the whole formed by the first magnetic resistance unit R32 and the second magnetic resistance unit R34 changes in the opposite direction and with the same size as the resistance change of the whole formed by the first magnetic resistance unit R31 and the second magnetic resistance unit R33, so that the differential signal S5 of the Z-axis bridge formed by 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 has an approximately linear change relationship with the Z-axis component of the external magnetic field, as follows:

[0081] wherein MR and Hk represent the intrinsic properties of the magnetic tunnel junction 150, respectively, the magnetic resistance and the anisotropy field; V P5 represent the output signal of the output terminal P5, V N5 represent the output signal of the output terminal N5; Hz represents the Z-axis component of the external magnetic field; γ1 represents the proportion 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 turning piece 150; γ2 represents the proportion 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 turning piece 150.

[0082] In this embodiment, by connecting the first magnetic resistance unit R31 and the second magnetic resistance unit R33 in series or in parallel to form a whole, and connecting the first magnetic resistance unit R32 and the second magnetic resistance unit R34 in series or in parallel to form a whole, and then constructing the Z-axis electric bridge, the power consumption of the Z-axis electric bridge can be reduced.

[0083] In one embodiment, as shown in FIGS. 16-22, at least part of the first magnetic tunnel junction and the second magnetic tunnel junction have a second sensitivity direction, the directions of the first sensitivity direction and the second sensitivity direction are opposite; the first magnetic tunnel junction with the second sensitivity direction is connected in series and / or in parallel to form a plurality of third magnetic resistance units, the second magnetic tunnel junction with the second sensitivity direction is connected in series and / or in parallel to form a plurality of fourth magnetic resistance units, and the first magnetic resistance unit, the second magnetic resistance unit, the third magnetic resistance unit and the fourth magnetic resistance unit include equal number of magnetic tunnel junctions 150.

[0084] When the symmetry plane of the mirror symmetry of the first soft magnet 182 and the second soft magnet 184 is consistent with the symmetry plane of the mirror symmetry of the first magnetic tunnel junction and the second magnetic tunnel junction, under the turning effect of the first soft magnet 182 and the second soft magnet 184, the magnetic field directions of the to-be-detected magnetic field at the positions of the first magnetic tunnel junction and the second magnetic tunnel junction are opposite, and the magnetic field sizes are equal, that is, the magnetic field directions of the to-be-detected magnetic field at the positions of the first magnetic resistance unit and the second magnetic resistance unit are opposite, and the magnetic field sizes are equal, the magnetic field directions of the to-be-detected magnetic field at the positions of the third magnetic resistance unit and the fourth magnetic resistance unit are opposite, and the magnetic field sizes are equal, and the magnetic field directions of the to-be-detected magnetic field at the positions of the first magnetic resistance unit and the third magnetic resistance unit are the same, and the magnetic field sizes 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, the sensitivity direction of the first magnetic tunnel junction constituting the third magnetic resistance unit and the sensitivity direction of the second magnetic tunnel junction constituting the fourth magnetic resistance unit are both the second sensitivity direction opposite to the first sensitivity direction, under the action of the to-be-detected magnetic field, the resistances of the first magnetic resistance unit and the fourth magnetic resistance unit are both increased or decreased, the resistances of the second magnetic resistance unit and the third magnetic resistance unit are opposite to the resistances of the first magnetic resistance unit and the fourth magnetic resistance unit in the change direction, and the change sizes are equal, in this way, the first magnetic resistance unit, the second magnetic resistance unit, the third magnetic resistance unit and the fourth magnetic resistance unit can be connected to constitute a Z-axis bridge, and the magnetic field converted by the magnetic field turning piece 180 is detected, so that the detection of the external Z-axis direction magnetic field is realized.

[0085] It can be understood that in the actual process, there can be process errors, so that the symmetry plane of the first soft magnet 182 and the second soft magnet 184 is inconsistent with the symmetry plane of the first magnetic tunnel junction and the second magnetic tunnel junction. For example, as shown in FIG. 22, the symmetry plane of the first magnetic tunnel junction and the second magnetic tunnel junction is offset to the negative direction of the Y axis relative to the symmetry plane of the first soft magnet 182 and the second soft magnet 184, and the to-be-detected magnetic field at the positions of the first magnetic resistance unit, the second magnetic resistance unit, the third magnetic resistance unit and the fourth magnetic resistance unit changes due to the offset. Because of the offset, the changes of the to-be-detected magnetic field at the first magnetic resistance unit and the corresponding fourth magnetic resistance unit are the same, and the sensitivity directions of the magnetic tunnel junction 150 of the first magnetic resistance unit and the corresponding fourth magnetic resistance unit are opposite. Similarly, the changes of the to-be-detected magnetic field at the second magnetic resistance unit and the corresponding third magnetic resistance unit are the same, and the sensitivity directions of the magnetic tunnel junction 150 of the second magnetic resistance unit and the corresponding third magnetic resistance unit are opposite. In this way, the Z-axis bridge is formed by the first magnetic resistance unit, the second magnetic resistance unit, the third magnetic resistance unit and the fourth magnetic resistance unit, and in the case that the symmetry plane is inconsistent due to the process error, the detection of the external Z-axis direction magnetic field can still be realized, and by connecting the first magnetic resistance unit and the corresponding fourth magnetic resistance unit in series or parallel, and connecting the second magnetic resistance unit and the corresponding third magnetic resistance unit in series or parallel, the zero point offset and the sensitivity change caused by the process alignment error can be effectively offset or reduced.

[0086] In one embodiment, as shown in FIG. 16 and FIG. 17, the first magnetoresistance unit includes a plurality of first magnetic tunnel junctions with the first sensitivity direction in series and / or in parallel to form the first magnetoresistance unit R31 outside the first soft magnet 182, and a plurality of first magnetic tunnel junctions with the first sensitivity direction in series and / or in parallel to form the first magnetoresistance unit R32 inside the first soft magnet 182, the second magnetoresistance unit includes a plurality of second magnetic tunnel junctions with the first sensitivity direction in series and / or in parallel to form the second magnetoresistance unit R33 inside the second soft magnet 184, and a plurality of second magnetic tunnel junctions with the first sensitivity direction in series and / or in parallel to form the second magnetoresistance unit R34 outside the second soft magnet 184; the third magnetoresistance unit includes a plurality of first magnetic tunnel junctions with the second sensitivity direction in series and / or in parallel to form the third magnetoresistance unit R33' inside the first soft magnet 182, and a plurality of first magnetic tunnel junctions with the second sensitivity direction in series and / or in parallel to form the third magnetoresistance unit R34' outside the first soft magnet 182, the fourth magnetoresistance unit includes a plurality of second magnetic tunnel junctions with the second sensitivity direction in series and / or in parallel to form the fourth magnetoresistance unit R31' outside the second soft magnet 184, and a plurality of second magnetic tunnel junctions with the second sensitivity direction in series and / or in parallel to form the fourth magnetoresistance unit R32' inside 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.

[0087] Specifically, as shown in FIG. 17 and FIG. 18, the first magnetoresistance unit R31 and the second magnetoresistance unit R33 are connected in series or in parallel to form a first resistance, the first magnetoresistance unit R32 and the second magnetoresistance unit R34 are connected in series or in parallel to form a second resistance, the third magnetoresistance unit R34' and the fourth magnetoresistance unit R32' are connected in series or in parallel to form a third resistance, and the third magnetoresistance unit R33' and the fourth magnetoresistance unit R31' are connected in series or in parallel to form a fourth resistance. One first resistance and one fourth resistance are connected in parallel to the output end N6 and the power supply end VCC6, and the other first resistance and the other fourth resistance are connected in parallel to the output end P6 and the ground end GND; one second resistance and one third resistance are connected in parallel to the output end P6 and the power supply end VCC6, and the other second resistance and the other third resistance are connected in parallel to the output N6 and the ground end GND.

[0088] When the symmetry plane of the mirror symmetry of the first soft magnet 182 and the second soft magnet 184 is consistent with the symmetry plane of the mirror symmetry of the first magnetic tunnel junction and the second magnetic tunnel junction, the to-be-detected magnetic field at the first magnetic resistance unit R31 and the third magnetic resistance unit R34' is γ1 Hz, the to-be-detected magnetic field at the first magnetic resistance unit R32 and the third magnetic resistance unit R33' is γ2 Hz, the to-be-detected magnetic field at the second magnetic resistance unit R33 and the fourth magnetic resistance unit R32' is -γ2 Hz, and the to-be-detected magnetic field at the second magnetic resistance unit R34 and the fourth magnetic resistance unit R31' is -γ1 Hz. Because 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 to-be-detected magnetic field, the resistance of the whole formed by the parallel connection of the first resistance and the fourth resistance increases or decreases, the resistance change of the whole formed by the parallel connection of the second resistance and the third resistance is opposite to the resistance change direction of the whole formed by the parallel connection of the first resistance and the fourth resistance, and the change size is equal, so the first resistance, the second resistance, the third resistance and the fourth resistance can constitute a Z-axis bridge.

[0089] When there is a process error, taking the bridge arm formed by the first resistance and the fourth resistance as an example, that is, taking 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. As shown in FIG. 22, because of the process error, the to-be-detected magnetic field at the position of the first magnetic resistance unit R31 is (γ1+Δγ1) Hz, and the to-be-detected magnetic field at the position of the fourth magnetic resistance unit R31' is -(γ1-Δγ1) Hz. Because the sensitivity directions of the magnetic tunnel junction 150 constituting the first magnetic resistance unit R31 and the fourth magnetic resistance unit R31' are opposite, by connecting the first magnetic resistance unit R31 and the fourth magnetic resistance unit R31' in parallel, the zero point offset and the sensitivity change caused by the process alignment error can be effectively offset or reduced. Similarly, by connecting the second magnetic resistance unit R33 and the third magnetic resistance unit R33' in parallel, the zero point offset and the sensitivity change caused by the process alignment error can also be effectively offset or reduced.

[0090] In another embodiment, as shown in FIG. 19 and FIG. 20, the first magnetic resistance unit R31 and the second magnetic resistance unit R33 are connected in series or in parallel to form a first resistance, the first magnetic resistance unit R32 and the second magnetic resistance unit R34 are connected in series or in parallel to form a second resistance, the third magnetic resistance unit R34' and the fourth magnetic resistance unit R32' are connected in series or in parallel to form a third resistance, 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 resistance. One first resistance and one fourth resistance are connected in series to the output end N6 and the power supply end VCC6, and the other first resistance and the other fourth resistance are connected in series to the output end P6 and the ground end GND; one second resistance and one third resistance are connected in series to the output end P6 and the power supply end VCC6, and the other second resistance and the other third resistance are connected in series to the output N6 and the ground end GND.

[0091] Similarly, when the symmetry plane of the mirror image symmetry of the first soft magnetic body 182 and the second soft magnetic body 184 is consistent with the symmetry plane of the mirror image symmetry 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 γ1 Hz, the magnetic field to be measured at the first magnetic resistance unit R32 and the third magnetic resistance unit R33' is γ2 Hz, the magnetic field to be measured at the second magnetic resistance unit R33 and the fourth magnetic resistance unit R32' is -γ2 Hz, and the magnetic field to be measured at the second magnetic resistance unit R34 and the fourth magnetic resistance unit R31' is -γ1 Hz. Because 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 resistance and the fourth resistance connected in series increases or decreases, and the resistance change of the whole formed by the second resistance and the third resistance connected in series is opposite to the resistance change of the whole formed by the first resistance and the fourth resistance connected in series in direction and equal in size, so that the first resistance, the second resistance, the third resistance, and the fourth resistance can form a Z-axis bridge. It can be understood that the Z-axis bridge in the embodiment can also effectively offset or reduce the zero point shift and sensitivity change caused by the process alignment error, which will not be described here.

[0092] It can be understood that, in other embodiments, the Z-axis bridge composed of the first magnetic resistance unit R31 and the second magnetic resistance unit R34 shown in FIG. 11 can also be offset or reduced by the process alignment error to bring about zero point shift and sensitivity change by connecting or connecting in parallel the corresponding fourth magnetic resistance unit R31' and the corresponding third magnetic resistance unit R34' in series. Specifically, the whole formed by connecting or connecting in parallel the first magnetic resistance unit R31 and the fourth magnetic resistance unit R31' in series as a bridge arm, and the whole formed by connecting or connecting in parallel the second magnetic resistance unit R34 and the third magnetic resistance unit R34' in series as a bridge arm to form the Z-axis bridge.

[0093] It can be understood that, in other embodiments, the Z-axis bridge composed of the first magnetic resistance unit R32 and the second magnetic resistance unit R33 shown in FIG. 13 can also be offset or reduced by the process alignment error to bring about zero point shift and sensitivity change by connecting or connecting in parallel the corresponding fourth magnetic resistance unit R32' and the corresponding third magnetic resistance unit R33' in series. Specifically, the whole formed by connecting or connecting in parallel the first magnetic resistance unit R32 and the fourth magnetic resistance unit R32' in series as a bridge arm, and the whole formed by connecting or connecting in parallel the second magnetic resistance unit R33 and the third magnetic resistance unit R33' in series as a bridge arm to form the Z-axis bridge.

[0094] In one embodiment, a preparation method of a three-axis magnetic sensor is also provided, comprising:

[0095] A substrate is provided, the substrate is built-in with a magnetic field turning piece, the magnetic field turning piece is inclined between the third direction and the first direction / second direction, and is used for turning the magnetic field of the third direction to have a magnetic field component of the first direction / second direction;

[0096] A magnetic tunnel junction is formed on the substrate; the plane of the substrate is provided with a first magnetic field sensitive area, a second magnetic field sensitive area and a third magnetic field sensitive area, and the first magnetic field sensitive area, the second magnetic field sensitive area and the third magnetic field sensitive area are all composed of the magnetic tunnel junction in series, in parallel or in series and parallel combination; the magnetic tunnel junction located in the first magnetic field sensitive area has a pinning direction along the first direction, 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 turning piece 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. Wherein, 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.

[0097] It should be noted that the specific structure of the substrate, and the arrangement and connection relationship of the magnetic tunnel junctions in the first magnetic field sensitive area, the second magnetic field sensitive area and the third magnetic field sensitive area are explained and described in detail in the above three-axis magnetic sensor, which will not be repeated here.

[0098] Specifically, the preparation process of the three-axis magnetic sensor is as follows:

[0099] As shown in FIG. 23, a substrate 112 is provided first, which includes a CMOS wafer layer 1122 and a CMOS signal layer 1124 disposed on the CMOS wafer layer 1122. The CMOS wafer layer 1122 has integrated circuits composed of a plurality of MOS transistors, which can process analog signals generated by the first magnetic field sensitive region, the second magnetic field sensitive region and the third magnetic field sensitive region in response to an external magnetic field to obtain digital signals. The CMOS signal layer 1124 can realize functions such as receiving of the analog signals and outputting of the digital signals. The CMOS signal layer 1124 can be in the form of a metal layer, an integrated circuit layer or the like. The CMOS signal layer 1124 can also be in the form of a coil, which can be used as a self-checking coil to generate a self-checking magnetic field to check whether the sensor functions normally, or 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 region 120, the second magnetic field sensitive region 130 and the third magnetic field sensitive region 140. Further, the substrate 112 can further include a protective layer 1126 disposed on the CMOS signal layer 1124, which can protect the CMOS signal layer 1124. The material of the protective layer 1126 can be silicon oxide (SiO x ) or aluminum oxide (AlO x ) or the like.

[0100] As shown in FIG. 24, an inclined structure layer 114 is formed on the surface of the substrate 112, which can be a silicon oxide layer. As shown in FIG. 25, the inclined structure layer 114 is etched to form grooves as inclined structures, and the etching stops at the CMOS signal layer 1124. As shown in FIG. 26, a thin film is deposited on the bottom of the grooves, and the thin film on part of the bottom of the grooves is etched to expose part of the CMOS signal layer 1124. The material of the thin film can be one or both of silicon oxide (SiO x ) and silicon nitride (SiN x ). As shown in FIG. 27, a thin film 180a is deposited on the inclined structure layer 114, which includes a seed layer (Ta / Ru), a nickel-iron layer and a cap layer (TiN x / TaN x ) in sequence, which protects the nickel-iron layer. As shown in FIG. 28, the thin film 180a is etched to retain the thin film on the inclined surfaces on both sides of the grooves of the inclined structure layer 114, which is used as a magnetic field turning piece 180 to change the direction of the magnetic field, and to retain the thin film in the grooves of the inclined structure layer 114, which is used as a thin film 180b for electrical connection and is in contact with the CMOS signal layer 1124.

[0101] As shown in FIG. 29, the medium layer 116 is deposited twice on the inclined structure layer 114, the first medium layer 1162 is silicon nitride, and the second medium layer 1164 is silicon oxide or aluminum oxide with lower hardness. The first medium layer 1162 and the second medium layer 1164 form the medium layer 116. The substrate 112, the inclined structure layer 114, and the medium layer 116 form the substrate 110. As shown in FIG. 30, the TMR magnetic multilayer film 150a is deposited on the plane of the medium layer 116. The TMR magnetic multilayer film 150a is a multilayer structure, which includes the structure of the magnetic tunnel junction 150 and the first metal layer 190. As shown in FIG. 31, the TMR magnetic multilayer film 150a is etched to reserve the part for the first metal layer 190 and the magnetic tunnel junction 150. As shown in FIG. 32, the photoresist 190a is coated on the substrate 110 and is subjected to photolithography to reserve the part of the photoresist 190a on the TMR magnetic multilayer film 150a for the magnetic tunnel junction 150. Then, the magnetic tunnel junction 150 is etched to stop at the bottom metal of the TMR magnetic multilayer film 150a, to obtain the magnetic tunnel junction 150 and the first metal layer 190. The first metal layer 190 is used to connect the magnetic tunnel junctions 150.

[0102] As shown in FIG. 33, the first part of the insulating layer 170 is deposited on the substrate 110 to cover the medium layer 116, the magnetic tunnel junction 150, the first metal layer 190, and the remaining photoresist 190a. The material of the insulating layer 170 can be silicon oxide or aluminum oxide. As shown in FIG. 34, the insulating layer 170 covering the magnetic tunnel junction 150 and the photoresist 190a are removed by photolithography to expose the magnetic tunnel junction 150. Meanwhile, the insulating layer 170 and the medium layer 116 are also subjected to photolithography to form the through hole 170a to expose the film 180b for electrical connection. As shown in FIG. 35, the second metal layer 200 is formed by metal plating and etching on the substrate 110. The second metal layer 200 connects the magnetic tunnel junctions 150 and extends to the film 180b for electrical connection through the through hole 170a, to electrically connect the magnetic tunnel junction 140 and the film 180b to receive the output signal of the bridge composed of the magnetic tunnel junction 150. As shown in FIG. 36, the second part of the insulating layer 170 is deposited on the substrate 110 to cover the second metal layer 200, and then is etched to expose the part of the second metal layer 200 in the through hole 170a for subsequent electrical connection.

[0103] As shown in Fig. 37, after the metal deposition and etching of the substrate 110, the top metal layer 210 is obtained. Part of the top metal layer 210 is used to form the coil 160, and part of the top metal layer 210 is used to connect with the exposed part of the second metal layer 200. Finally, as shown in Fig. 38, the third part of the insulating layer 170 is deposited on the substrate 110 and the conductive solder opening 170b is formed to expose the part of the top metal layer 210 connected with the second metal layer 200, so as to obtain the complete insulating layer 170, which protects the top metal layer 210 and also can be used to electrically connect the part of the top metal layer 210 connected with the second metal layer 200 with external devices through the conductive solder opening 170b.

[0104] The technical features of the above embodiments can be combined in any manner. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described, however, as long as the combinations of the technical features do not contradict each other, they should be considered as falling within the scope of the present disclosure.

[0105] The above embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the scope of the patent. It should be pointed out that for those skilled in the art, some modifications 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 present application should be subject to the appended claims.

Claims

1. A triaxial magnetic sensor, characterized in that, include: A substrate, wherein the substrate has a built-in magnetic field deflector, the magnetic field deflector being inclined between a third direction and a first / second direction, for deflecting the magnetic field in the third direction so that it has magnetic field components in the first / second direction. A first magnetic field sensitive region, a second magnetic field sensitive region, and a third magnetic field sensitive region are disposed on the plane of the substrate. Each of the three magnetic field sensitive regions is composed of magnetic tunnel junctions connected in series, in parallel, or in a combination of series and parallel connections. The magnetic tunnel junction in the first magnetic field sensitive region has a pinning direction along a first direction, and the magnetic tunnel junction in the second magnetic field sensitive region has a pinning direction along a second direction. The third magnetic field sensitive region is disposed on the plane of the substrate at a position corresponding to the magnetic field deflector, and the magnetic tunnel junction in the third magnetic field sensitive region has a pinning direction along the first / second direction. Wherein, 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 triaxial magnetic sensor according to claim 1, characterized in that, The magnetic field deflector comprises a seed layer, a nickel-iron layer, and a capping layer stacked sequentially.

3. The triaxial magnetic sensor according to claim 2, characterized in that, The seed layer is made of tantalum or ruthenium, and the capping layer is made of titanium nitride or tantalum nitride.

4. The triaxial magnetic sensor according to claim 1, characterized in that, The substrate includes a substrate, an inclined structure layer and a dielectric layer stacked sequentially. The magnetic field deflector is disposed on the inclined surface of the inclined structure layer. The inclined surface of the inclined structure layer is inclined between a third direction and a first / second direction. The magnetic tunnel junction is disposed on the plane of the dielectric layer.

5. The triaxial magnetic sensor according to claim 4, characterized in that, The inclined structure in the inclined structure layer is a groove or a protrusion; the magnetic field deflector is entirely located on the inclined surface of the inclined structure, or most of the magnetic field deflector is located on the inclined surface of the inclined structure, with the remaining part extending to the top of the inclined structure.

6. The triaxial magnetic sensor according to claim 4, characterized in that, The magnetic tunnel junction of the third magnetic field sensitive region is located on the plane of the dielectric layer and is disposed on both sides of the top of the magnetic field deflector.

7. The triaxial magnetic sensor according to claim 4, characterized in that, The inclination angle of the inclined surface of the inclined structural layer is 15 degrees to 85 degrees.

8. The triaxial magnetic sensor according to claim 4, characterized in that, The thickness of the inclined structural layer is 3-5 micrometers.

9. The triaxial magnetic sensor according to claim 4, characterized in that, The dielectric layer includes a first dielectric layer and a second dielectric layer, with the first dielectric layer located between the inclined structure layer and the second dielectric layer, and the magnetic tunnel junction array arranged on the plane of the second dielectric layer.

10. The triaxial magnetic sensor according to claim 9, characterized in that, The first dielectric layer is made of silicon nitride, and the second dielectric layer is made of silicon oxide or aluminum oxide, which have relatively low hardness.

11. The triaxial magnetic sensor according to any one of claims 1 to 10, characterized in that, The magnetic field deflector includes a first soft magnet and a second soft magnet arranged in a mirror-symmetric manner; 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, wherein the first magnetic tunnel junction and the second magnetic tunnel junction are arranged in a mirror-symmetric manner. The first and second soft magnets cause the external third-direction magnetic field to be distorted, generating a component perpendicular to the third direction, to form the magnetic field to be detected in the third magnetic field sensitive area; at least a portion of the first and second magnetic tunnel junctions have 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 magnetoresistive 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 magnetoresistive units, and the number of magnetic tunnel junctions included in the first and second magnetoresistive units is equal.

12. The triaxial magnetic sensor according to claim 11, characterized in that, The first magnetoresistive unit includes a first magnetoresistive unit R31 formed by a plurality of first magnetic tunnel junctions connected in series and / or in parallel located outside the first soft magnet; the second magnetoresistive unit includes a second magnetoresistive unit R34 formed by a plurality of second magnetic tunnel junctions connected in series and / or in parallel located outside the second soft magnet; and / or, the first magnetoresistive unit includes a first magnetoresistive unit R32 formed by a plurality of first magnetic tunnel junctions connected in series and / or in parallel located inside the first soft magnet; the second magnetoresistive unit includes a second magnetoresistive unit R33 formed by a plurality of second magnetic tunnel junctions connected in series and / or in parallel located inside the second soft magnet.

13. The triaxial magnetic sensor according to claim 12, characterized in that, The first magnetoresistive unit R31 and the second magnetoresistive unit R34 are connected to form a Z-axis bridge.

14. The triaxial magnetic sensor according to claim 12, characterized in that, The first magnetoresistive unit R32 and the second magnetoresistive unit R33 are connected to form a Z-axis bridge.

15. The triaxial magnetic sensor according to claim 12, characterized in that, The first magnetoresistive unit R31, the first magnetoresistive unit R32, the second magnetoresistive unit R33, and the second magnetoresistive unit R34 are connected to form a Z-axis bridge.

16. The triaxial magnetic sensor according to claim 12, characterized in that, The first magnetic tunnel junction and the second magnetic tunnel junction each have at least a second sensitivity direction, and the first sensitivity direction and the second sensitivity direction are opposite in direction; the first magnetic tunnel junctions with the second sensitivity direction are connected in series and / or in parallel to form a plurality of third magnetoresistive 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 magnetoresistive units, and the first magnetoresistive unit, the second magnetoresistive unit, the third magnetoresistive unit and the fourth magnetoresistive unit include the same number of magnetic tunnel junctions; The third magnetoresistive unit includes a third magnetoresistive unit R33' formed by a plurality of first magnetic tunnel junctions connected in series and / or in parallel located inside the first soft magnet; the fourth magnetoresistive unit includes a fourth magnetoresistive unit R32' formed by a plurality of second magnetic tunnel junctions connected in series and / or in parallel located inside the second soft magnet; and / or, the third magnetoresistive unit includes a third magnetoresistive unit R34' formed by a plurality of first magnetic tunnel junctions connected in series and / or in parallel located outside the first soft magnet; the fourth magnetoresistive unit includes a fourth magnetoresistive unit R31' formed by a plurality of second magnetic tunnel junctions connected in series and / or in parallel located outside the second soft magnet.

17. The triaxial magnetic sensor according to claim 16, characterized in that, The first magnetoresistive unit R31, the second magnetoresistive unit R34, the third magnetoresistive unit R34', and the fourth magnetoresistive unit R31' are connected to form a Z-axis bridge.

18. The triaxial magnetic sensor according to claim 16, characterized in that, The first magnetoresistive unit R32, the second magnetoresistive unit R33, the third magnetoresistive unit R33', and the fourth magnetoresistive unit R32' are connected to form a Z-axis bridge.

19. The triaxial magnetic sensor according to claim 16, characterized in that, The first magnetoresistive unit R31, the first magnetoresistive unit R32, the second magnetoresistive unit R33, the second magnetoresistive unit R34, the third magnetoresistive unit R34', the third magnetoresistive unit R33', the fourth magnetoresistive unit R32', and the fourth magnetoresistive unit R31' are connected to form a Z-axis bridge.

20. A method for fabricating a triaxial magnetic sensor, characterized in that, include: A substrate is provided, wherein a magnetic field deflector is built into the substrate, the magnetic field deflector being inclined between a third direction and a first / second direction for deflecting the magnetic field in the third direction so that it has a magnetic field component in the first / second direction. A magnetic tunnel junction is formed on the substrate; a first magnetic field sensitive region, a second magnetic field sensitive region, and a third magnetic field sensitive region are provided on the plane of the substrate, and the first magnetic field sensitive region, the second magnetic field sensitive region, and the third magnetic field sensitive region are all composed of magnetic tunnel junctions connected in series, in parallel, or in a combination of series and parallel; the magnetic tunnel junction located in the first magnetic field sensitive region has a pinning direction along a first direction, and the magnetic tunnel junction located in the second magnetic field sensitive region has a pinning direction along a second direction; the third magnetic field sensitive region is located on the plane of the substrate at a position corresponding to the magnetic field deflector, and the magnetic tunnel junction located in the third magnetic field sensitive region has a pinning direction along the first direction / second direction; Wherein, 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.

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