CN220671606U - Triaxial magnetic sensor - Google Patents

Abstract

The present utility model provides a triaxial magnetic sensor, comprising: an anisotropic magnetoresistive sensor for sensing external magnetic fields in an X-axis direction and a Y-axis direction orthogonal to each other to generate an X-axis sensing voltage and a Y-axis sensing voltage; a horizontal hall sensor for sensing an external magnetic field in a Z-axis direction to generate a Z-axis sensing voltage representing a magnetic field component in the Z-axis direction of the sensed external magnetic field, the Z-axis being orthogonal to the X-axis and the Y-axis; the signal processing circuit is electrically connected with the anisotropic magnetic resistance sensor and the horizontal Hall sensor and is used for converting the X-axis sensing voltage into a magnetic field component in the X-axis direction, converting the Y-axis sensing voltage into a magnetic field component in the Y-axis direction and converting the Z-axis sensing voltage into a magnetic field component in the Z-axis direction. Compared with the prior art, the utility model combines the magneto-resistance technology and the Hall technology, and adopts a complete planar technology to manufacture the triaxial magnetic sensor, thereby reducing the difficulty of technological manufacture.

Description

Triaxial magnetic sensor

[ field of technology ]

The utility model relates to the field of magnetic field sensors, in particular to a triaxial magnetic sensor.

[ background Art ]

Currently, the commonly used triaxial magnetic sensing is implemented by using technologies such as Hall (Hall), anisotropic Magnetoresistance (AMR), giant Magnetoresistance (GMR), tunneling Magnetoresistance (TMR), and the like. The sensor generally only shows the three-axis detection function, the three-axis magnetic sensor is one chip, and the magnetic switch is the other chip. In the processing technology, the existing triaxial magnetic sensor needs to be matched with additional designs and technological methods to realize triaxial. For example, a Hall sensor generally adopts a horizontal Hall technology, the initial magnetic field detection direction of the Hall sensor is perpendicular to the surface of a chip, and a magnetic field steering structure such as a magnetic flux collector is matched to realize three axes. The initial magnetic field detection direction of the magnetic resistance sensor is parallel to the surface of the chip, and the three-axis detection can be realized by introducing a magnetic field steering structure such as a magnetic flux collector or a slope construction method, so that the process manufacturing difficulty is increased.

If the magnetic switch of the Z axis is made by the magneto-resistance technology (AMR, GMR, TMR), the magnetic switch will saturate when the magnetic field increases to a certain value, the output will be reduced to zero, and the state of the zero magnetic field and the saturated magnetic field cannot be distinguished.

Therefore, a new solution is needed to solve the above problems.

[ utility model ]

One of the purposes of the present utility model is to provide a three-axis magnetic sensor, which combines the magneto-resistance technology with the hall technology, and adopts a complete planar technology to manufacture the three-axis magnetic sensor, thereby reducing the difficulty of manufacturing the technology.

According to one aspect of the present utility model, there is provided a triaxial magnetic sensor including: a two-axis anisotropic magnetoresistive sensor for sensing external magnetic fields in an X-axis direction and a Y-axis direction orthogonal to each other to generate an X-axis sensing voltage representing a magnetic field component in the X-axis direction of the sensed external magnetic field and a Y-axis sensing voltage representing a magnetic field component in the Y-axis direction of the sensed external magnetic field; a horizontal hall sensor for sensing an external magnetic field in a Z-axis direction to generate a Z-axis sensing voltage representing a magnetic field component in the Z-axis direction of the sensed external magnetic field, the Z-axis being mutually orthogonal to the X-axis and the Y-axis; the signal processing circuit is electrically connected with the two-axis anisotropic magneto-resistance sensor and the horizontal Hall sensor, and is used for converting the X-axis sensing voltage into a magnetic field component in the X-axis direction of the external magnetic field, converting the Y-axis sensing voltage into a magnetic field component in the Y-axis direction of the external magnetic field and converting the Z-axis sensing voltage into a magnetic field component in the Z-axis direction of the external magnetic field.

Further, the horizontal Hall sensor is used as a Z-axis magnetic switch; the signal processing circuit is also used for comparing the Z-axis sensing voltage with a preset switching threshold voltage so as to judge the switching state of the Z-axis magnetic switch.

Further, the two-axis anisotropic magneto-resistance sensor, the horizontal Hall sensor and the signal processing circuit are integrated in a single chip; the planes defined by the X axis and the Y axis are parallel to the single chip plane.

Further, the single chip comprises a substrate, and a first structural layer and a second structural layer which are laminated on the substrate, wherein the horizontal Hall sensor and the signal processing circuit are arranged in the first structural layer; the two-axis anisotropic magneto-resistance sensor is arranged in the second structural layer; the first structural layer is positioned on the substrate; the second structural layer is located above the first structural layer.

Further, the single chip further comprises an isolation layer and a third structural layer, wherein the isolation layer is positioned between the first structural layer and the second structural layer, and the two-axis anisotropic magneto-resistance sensor and the signal processing circuit are electrically connected through the isolation layer by via hole metal; the third structural layer is positioned above the second structural layer, and comprises the two-axis anisotropic magneto-resistance sensor protection layer and an electrode on the two-axis anisotropic magneto-resistance sensor protection layer, and the electrode is connected with the signal processing circuit through a via metal.

Further, the two-axis anisotropic magnetoresistive sensor comprises a first Wheatstone bridge and a second Wheatstone bridge which are orthogonally arranged, wherein the first Wheatstone bridge is used for sensing an external magnetic field in the X-axis direction so as to generate an X-axis sensing voltage; the second Wheatstone bridge is used for sensing an external magnetic field in the Y-axis direction to generate a Y-axis sensing voltage.

Further, the horizontal hall sensor includes: p-type silicon; and an N-type potential well formed by N-type silicon extending into the P-type silicon from the upper surface of the P-type silicon.

Further, the potential well is of a cross structure, which is called a Hall cross structure, and four ends of the Hall cross structure are sequentially a power supply end VDD, a first output end V+, a second output end negative V-and a ground end GND.

Further, the horizontal hall sensor comprises one hall cross structure; or the horizontal Hall sensor comprises four Hall cross structures, and the four Hall cross structures are sequentially rotated by 90 degrees in a plane parallel to the surface of the single chip; four power supply terminals VDD of the Hall cross structure are connected together, four first output terminals V+ are connected together, four second output terminals V-are connected together, and four grounding terminals GND are connected together.

Further, the switching threshold voltage is set according to the switching magnetic field value of the Z-axis magnetic switch; the switching threshold voltage is programmable; and/or the horizontal hall sensor is used as a unipolar trigger switch, a bipolar trigger switch or a latch switch.

Compared with the prior art, the utility model combines the magneto-resistance (AMR) technology and the Hall (Hall) technology, adopts a complete planar technology to manufacture the triaxial magnetic sensor, realizes the triaxial detection function by utilizing the respective initial magnetic field detection directions of the AMR technology and the Hall technology, and does not need to introduce a magnetic flux collector (or other magnetic conduction structures) or a slope structure, thereby reducing the manufacturing difficulty of the technology.

[ description of the drawings ]

In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the drawings that are needed in the description of the embodiments will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present utility model, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art. Wherein:

FIG. 1 is a schematic longitudinal cross-sectional view of a single-chip three-axis magnetic sensor with switching function according to an embodiment of the present utility model;

FIG. 2 is a schematic diagram of an equivalent bridge of a two-axis AMR sensor, such as that shown in FIG. 1, in accordance with one embodiment of the present utility model;

FIG. 3 is a schematic diagram of the structure of the magnetoresistive sensor unit according to the present utility model in one embodiment as illustrated in FIG. 2 in another embodiment;

FIG. 4 is a schematic view of a horizontal Hall sensor according to an embodiment of the present utility model, as shown in FIG. 1;

FIG. 5 is a schematic diagram of the output of the horizontal Hall sensor of FIG. 1 as a Hall magnetic switch in one embodiment of the present utility model;

FIG. 6 is a schematic diagram showing an output flow of the single-chip three-axis magnetic sensor with switching function shown in FIG. 1 according to an embodiment of the present utility model.

[ detailed description ] of the utility model

In order that the above-recited objects, features and advantages of the present utility model will become more readily apparent, a more particular description of the utility model will be rendered by reference to the appended drawings and appended detailed description.

Reference herein to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic may be included in at least one implementation of the utility model. The appearances of the phrase "in one embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Unless specifically stated otherwise, the terms connected, or connected herein denote an electrical connection, either directly or indirectly.

Fig. 1 is a schematic longitudinal sectional view of a single-chip tri-axial magnetic sensor with switching function according to an embodiment of the present utility model. The single-chip three-axis magnetic sensor having a switching function shown in fig. 1 includes a horizontal Hall (Hall) sensor, a two-axis AMR (anisotropic magnetoresistance) sensor, and a signal processing circuit formed based on the same silicon substrate (or semiconductor substrate) 110. For ease of description, a Cartesian coordinate system is defined in FIG. 1, wherein the X axis extends from left to right, the Z axis extends from bottom to top, the Y axis extends away from the viewer into the page, the Z axis meets the right hand rule with the X and Y axes, and the planes defined by the X and Y axes are parallel to the single chip plane.

The two-axis AMR sensor is configured to sense an external magnetic field (or magnetic field) in an X-axis direction and a Y-axis direction orthogonal to each other to generate an X-axis sensing voltage (or X-axis linear signal) and a Y-axis sensing voltage (or Y-axis linear signal). Wherein, the X-axis sensing voltage represents the sensed magnetic field component of the external magnetic field in the X-axis direction (or the magnetic induction intensity of the X-axis direction), and the Y-axis sensing voltage represents the sensed magnetic field component of the external magnetic field in the Y-axis direction (or the magnetic induction intensity of the Y-axis direction).

The horizontal hall sensor is used for sensing an external magnetic field in the Z-axis direction to generate a Z-axis sensing voltage (or a Z-axis linear signal), and the Z-axis sensing voltage represents a sensed magnetic field component in the Z-axis direction (or magnetic induction intensity in the Z-axis direction) of the external magnetic field.

The signal processing circuit is electrically connected with the two-axis anisotropic magnetic resistance sensor and the horizontal Hall sensor, and is used for converting the X-axis sensing voltage into a magnetic field component in the X-axis direction of the external magnetic field, converting the Y-axis sensing voltage into a magnetic field component in the Y-axis direction of the external magnetic field and converting the Z-axis sensing voltage into a magnetic field component in the Z-axis direction of the external magnetic field.

If the magnetic switch of the Z axis is made by the magneto-resistance technology (AMR, GMR, TMR), the magnetic switch will saturate when the magnetic field increases to a certain value, the output will probably drop to zero, so that the state of the zero magnetic field and the saturated magnetic field cannot be distinguished, and the Hall sensor will not have the situation, thus being suitable as a magnetic switch sensor. Therefore, the horizontal hall sensor shown in fig. 1 of the present utility model can be used as a Z-axis magnetic switch, and the signal processing circuit is also configured to compare the Z-axis sensing voltage generated by the horizontal hall sensor with a preset switching threshold voltage (or switching threshold signal) to determine the switching state of the Z-axis magnetic switch. In one embodiment, the switching threshold voltage may be set according to the magnetic field value of the switching of the Z-axis magnetic switch, and may be programmable.

The horizontal hall sensor and the signal processing circuit are disposed on the first structural layer 120, the two-axis AMR sensor is disposed on the second structural layer 140, and the first structural layer 120 and the second structural layer 140 are stacked on the silicon substrate 110. Wherein a first structural layer 120 provided with a horizontal hall sensor and a signal processing circuit is located on the substrate 110; the second structure layer 140 provided with the two-axis AMR sensor is located above the first structure layer 110, and the signal processing circuit and the two-axis AMR sensor are electrically connected through a via metal (not shown). The structural layers 120, 140 are formed of multiple semiconductor process layers for performing a function, and are a complete functional structural layer, not a single layer. In one embodiment, the horizontal hall sensors and signal processing circuitry in the first structural layer 120 are fabricated using standard CMOS processes, which includes a multi-layer structure.

In the embodiment shown in fig. 1, the single-chip tri-axial magnetic sensor with switching function further includes an isolation layer 130 and a third structural layer 150. Wherein the isolation layer 130 is located between the first structural layer 120 and the second structural layer 140; the third structural layer 150 is located above the second structural layer 140. The isolation layer 130 is provided with a via (not shown) through its thickness, through which via metal (not shown) passes (or through which via metal passes) to electrically connect the two-axis AMR sensor and the signal processing circuit. The isolation layer 130 may be made of silicon nitride, silicon dioxide, etc., and the via metal may be Al, cu, etc. The roughness of the upper surface of the isolation layer 130 is small enough that it can be planarized by chemical mechanical polishing or the like to reduce the roughness. The third structural layer 150 includes a two-axis AMR sensor protection layer and electrodes thereon, the electrodes being connected to a signal processing circuit by via metal, and an output signal of the signal processing circuit being transmitted to the electrodes of the third structural layer 150 through the via metal.

The single-chip three-axis magnetic sensor with the switching function shown in fig. 1 is completely integrated by a single chip, and the final package body adopts wafer level package, and can also adopt plastic package.

Referring to FIG. 2, an equivalent bridge diagram of a two-axis AMR sensor according to an embodiment of the present utility model is shown in FIG. 1. A rectangular coordinate system is defined in fig. 2, in which the x-axis extends from left to right and the y-axis extends from bottom to top. The two-axis AMR sensor shown in fig. 2 includes a first wheatstone bridge 200a and a second wheatstone bridge 200b, wherein the first wheatstone bridge 200a is configured to sense an external magnetic field in an X-axis direction to generate an X-axis sensing voltage; the second Wheatstone bridge 200b is used for sensing an external magnetic field in the Y-axis direction to generate a Y-axis sensing voltage.

The first wheatstone bridge 200a includes magnetoresistive sensor units (or legs) 210a, 210b, 210c, and 210d, the magnetoresistive sensor units (or legs) 210a, 210b, 210c, and 210d being interconnected to form a wheatstone bridge, wherein the magnetoresistive sensor unit 210a is connected between a power supply terminal VDD and a signal positive terminal v+; the magnetoresistive sensor unit 210b is connected between the signal positive terminal v+ and the ground terminal GND; the magnetoresistive sensor unit 210c is connected between the negative signal terminal V-and ground GND; the magnetoresistive sensor unit 210d is connected between the power supply terminal VDD and the negative signal terminal V-; the output terminals of the first Wheatstone bridge 200a are a positive signal terminal V+ and a negative signal terminal V-, i.e., the positive signal terminal V+ and the negative signal terminal V of the first Wheatstone bridge 200a are used for generating the X-axis sensing voltage. For example, when a magnetic field in the X positive direction is applied, the resistances of magnetoresistive sensor units (or legs) 210a and 210c decrease, and the resistances of magnetoresistive sensor units (or legs) 210b and 210d increase.

In the first Wheatstone bridge 200a, each magnetoresistive sensor unit 210a, 210b, 210c, 210d includes a magnetoresistive strip 230 and a plurality of conductive strips 220 parallel to each other, the long-side direction of the magnetoresistive strip 230 is parallel to the magnetically easy axis of the magnetoresistive sensor unit, and the plurality of conductive strips 220 parallel to each other are formed on the magnetoresistive strip 230 and form a predetermined angle with the magnetoresistive strip 230. The conductive strip 220 is a high conductivity metal, and a portion of the structure of the conductive strip 220 acts as a shorting strip over the magnetoresistive strip 230 to direct the direction of current flow.

The second Wheatstone bridge 200b is configured identically to the first Wheatstone bridge 200a, and the second Wheatstone bridge 200b is rotated 90 degrees, in the schematic diagram 220b, counter-clockwise or clockwise by 90 degrees, as compared to the first Wheatstone bridge 200 a. It can also be said that the first wheatstone bridge 200a and the second wheatstone bridge 200b are arranged orthogonally.

Referring to FIG. 3, a schematic diagram of a magnetoresistive sensor unit according to an embodiment of the utility model as shown in FIG. 2 is shown. The magnetoresistive sensor unit (or bridge arm) shown in fig. 3 includes a plurality of magnetoresistive strips 230 arranged in parallel, wherein a plurality of conductive strips 220 parallel to each other are formed on each magnetoresistive strip 230, and the resistance values of the magnetoresistive sensor unit (or bridge arm) are matched by connecting the magnetoresistive strips 230 end to end.

In summary, the two-axis AMR sensor can be manufactured by adopting a complete planarization process, and other structures are not needed, so that the process difficulty is reduced.

Referring to fig. 4, a schematic structural diagram of a horizontal hall sensor according to an embodiment of the present utility model, as shown in fig. 1, is shown, and the structure is implemented by implanting an N-well on a P-type semiconductor substrate using a standard CMOS process, wherein the detection direction of the horizontal hall sensor is the Z-axis, and no other structure is needed. The horizontal hall sensor shown in fig. 4 includes: p-type silicon; an N-type potential well formed of N-type silicon extending from an upper surface of the P-type silicon into the P-type silicon.

The horizontal hall sensor shown in fig. 4a includes an N-type potential well, which is a cross structure, and is called a hall cross structure, and four ends of the hall cross structure are sequentially a power supply end VDD, a first output end v+, a second output end negative V-and a ground end GND. When a magnetic field in the Z-axis direction is applied, the difference output between the output terminals v+ and V-, i.e., the Z-axis sensing voltage, is proportional to the magnetic field, and 310a is the direction of the current in the horizontal hall-cross structure.

The horizontal hall sensor shown in fig. 4b comprises four hall cross structures shown in fig. 4a, wherein the four hall cross structures are sequentially rotated by 90 degrees in a plane parallel to the surface of a single chip (namely, the ports of the four hall cross structures are sequentially rotated by 90 degrees to form a structure that the current included angle of two adjacent hall cross structures is 90 degrees); the four power supply terminals VDD of the four Hall cross structures are connected together, the four first output terminals V+ are connected together, the four second output terminals V-are connected together, and the four grounding terminals GND are connected together. Wherein 310b, 310c, 310d, 310e are the directions of the respective currents in the four hall crosses respectively.

Referring to fig. 5, a schematic diagram of the output of the horizontal Hall sensor of fig. 1 as a Hall magnetic switch according to an embodiment of the present utility model is shown. In the embodiment shown in fig. 5, the Hall magnetic switch can be output in three manners 400a, 400b and 400c, that is, the horizontal Hall sensor shown in fig. 1 can be used as a single-pole trigger switch, a full-pole trigger switch or a latch switch. Wherein 400a is N-pole triggering and releasing, which is monopole Hall output, when the magnetic field is larger than N-pole triggering magnetic field BopN, the signal processing circuit outputs low level (L); when the magnetic field is smaller than the N-pole release magnetic field BrpN, the signal processing circuit outputs a high level (H), and the monopole output can be triggered by the S pole. 400b is a full pole Hall output, and when the magnetic field is greater than the triggering magnetic field (BopN or BopS), the signal processing circuit outputs a low level (L); when the magnetic field is smaller than the release magnetic field (BrpN or BrpS), the signal processing circuit outputs a high level (H), and the N pole and the S pole can trigger and release. 400c is the output of the Hall latch switch, when the magnetic field of the N pole is larger than the triggering magnetic field BopN, the signal processing circuit outputs a low level (L), when the magnetic field of the S pole is larger than the releasing magnetic field BrpS, the signal processing circuit outputs a high level (H), and of course, the Hall latch switch can also be configured as S pole triggering and N pole releasing.

Fig. 6 is a schematic diagram showing an output flow of the single-chip tri-axial magnetic sensor with switching function shown in fig. 1 according to an embodiment of the present utility model, which includes the following steps.

Step 610, input, i.e. apply a magnetic field to be measured (or external magnetic field) B, whose magnetic field components in the x-axis, y-axis and z-axis are Bx, by and Bz, respectively.

Step 620, a two-axis AMR sensor is used to detect the X-axis and Y-axis magnetic fields and outputs proportional voltage signals Vx and Vy (or sense voltages Vx and Vy).

Step 630, the horizontal hall sensor is used to detect the magnetic field of the Z-axis and output a proportional voltage signal Vz (or sensing voltage Vz).

In step 640, the signal processing circuit amplifies, digitizes, and outputs magnetic field values Bx, by, and Bz the voltage signals Vx, vy, and Vz.

Step 650, the signal processing circuit compares the voltage signal Vz with the on-off threshold voltage inside the circuit, thereby outputting a low level or high level signal,

in step 660, the signal processing circuit determines the on/off state of the magnetic switch based on the low or high level signal.

In summary, the triaxial magnetic sensor with the switch function provided by the utility model has the following advantages:

1. the detection function of the triaxial magnetic sensor and the magnetic switch function are integrated together, and the triaxial detection and the opening and closing detection of the magnetic switch are simultaneously realized by using one chip.

The X and Y axes adopt AMR technology, and the detection of X and Y axis magnetic fields is realized by preparing AMR full bridges; the Z axis is prepared by adopting a horizontal Hall technology and adopting a standard CMOS (complementary metal oxide semiconductor) process, and has the function of a magnetic switch in the direction vertical to the surface of the chip while realizing the linear output of a Z axis magnetic field. The utility model can be applied to the fields of electronic consumer such as mobile phones, tablets and the like

3. The manufacturing method combines the magneto-resistance technology and the Hall technology, adopts a complete planar technology to manufacture the triaxial magnetic sensor with the magnetic switch function, utilizes the magneto-resistance technology and the Hall technology to detect the initial magnetic field respectively, does not need to introduce a magnetic flux collector (or other magnetic conduction structures) or a slope structure, and reduces the difficulty of the process manufacturing.

The 4.Z axis integrated magnetic switch can be an all-pole trigger switch, a single-pole trigger switch or a Hall latch switch.

In the present utility model, "connected", and the like mean electrically connected words, and unless otherwise indicated, mean directly or indirectly electrically connected.

The above description is merely of preferred embodiments of the present utility model, and the scope of the present utility model is not limited to the above embodiments, but all equivalent modifications or variations according to the present disclosure will be within the scope of the claims.

Claims (10)

1. A three-axis magnetic sensor, comprising:

a two-axis anisotropic magnetoresistive sensor for sensing external magnetic fields in an X-axis direction and a Y-axis direction orthogonal to each other to generate an X-axis sensing voltage representing a magnetic field component in the X-axis direction of the sensed external magnetic field and a Y-axis sensing voltage representing a magnetic field component in the Y-axis direction of the sensed external magnetic field;

a horizontal hall sensor for sensing an external magnetic field in a Z-axis direction to generate a Z-axis sensing voltage representing a magnetic field component in the Z-axis direction of the sensed external magnetic field, the Z-axis being mutually orthogonal to the X-axis and the Y-axis;

the signal processing circuit is electrically connected with the two-axis anisotropic magneto-resistance sensor and the horizontal Hall sensor, and is used for converting the X-axis sensing voltage into a magnetic field component in the X-axis direction of the external magnetic field, converting the Y-axis sensing voltage into a magnetic field component in the Y-axis direction of the external magnetic field and converting the Z-axis sensing voltage into a magnetic field component in the Z-axis direction of the external magnetic field.

2. The triaxial magnetic sensor according to claim 1,

the horizontal Hall sensor is used as a Z-axis magnetic switch;

the signal processing circuit is also used for comparing the Z-axis sensing voltage with a preset switching threshold voltage so as to judge the switching state of the Z-axis magnetic switch.

3. A triaxial magnetic sensor according to claim 1 or 2,

the two-axis anisotropic magneto-resistance sensor, the horizontal Hall sensor and the signal processing circuit are integrated in a single chip;

the planes defined by the X axis and the Y axis are parallel to the single chip plane.

4. A triaxial magnetic sensor according to claim 3,

the single chip comprises a substrate, a first structural layer and a second structural layer which are laminated on the substrate,

the horizontal Hall sensor and the signal processing circuit are arranged in the first structural layer;

the two-axis anisotropic magneto-resistance sensor is arranged in the second structural layer;

the first structural layer is positioned on the substrate;

the second structural layer is located above the first structural layer.

5. The triaxial magnetic sensor according to claim 4,

the single chip further comprises an isolation layer and a third structural layer,

the isolating layer is positioned between the first structural layer and the second structural layer, and the two-axis anisotropic magneto-resistance sensor and the signal processing circuit are electrically connected through the isolating layer by the via hole metal;

the third structural layer is positioned above the second structural layer, and comprises the two-axis anisotropic magneto-resistance sensor protection layer and an electrode on the two-axis anisotropic magneto-resistance sensor protection layer, and the electrode is connected with the signal processing circuit through a via metal.

6. A triaxial magnetic sensor according to claim 3,

the two-axis anisotropic magnetoresistive sensor comprises a first Wheatstone bridge and a second Wheatstone bridge which are orthogonally arranged,

the first Wheatstone bridge is used for sensing an external magnetic field in the X-axis direction to generate an X-axis sensing voltage;

the second Wheatstone bridge is used for sensing an external magnetic field in the Y-axis direction to generate a Y-axis sensing voltage.

7. The triaxial magnetic sensor according to claim 6,

the horizontal hall sensor includes:

p-type silicon;

and an N-type potential well formed by N-type silicon extending into the P-type silicon from the upper surface of the P-type silicon.

8. The triaxial magnetic sensor according to claim 7,

the potential well is a cross structure, which is called a hall cross structure,

the four ends of the Hall cross structure are sequentially provided with a power supply end VDD, a first output end V+ and a second output end negative V-and a ground end GND.

9. The three-axis magnetic sensor according to claim 8, wherein,

the horizontal Hall sensor comprises one Hall cross structure; or (b)

The horizontal Hall sensor comprises four Hall cross structures, and the four Hall cross structures are sequentially rotated by 90 degrees in a plane parallel to the surface of the single chip; four power supply terminals VDD of the Hall cross structure are connected together, four first output terminals V+ are connected together, four second output terminals V-are connected together, and four grounding terminals GND are connected together.

10. A triaxial magnetic sensor according to claim 2,

the switching threshold voltage is set according to the switching magnetic field value of the Z-axis magnetic switch;

the switching threshold voltage is programmable; and/or

The horizontal hall sensor is used as a unipolar trigger switch, a bipolar trigger switch or a latch switch.