Magnetic Sensor and Method for Preparing the Magnetic Sensor

Abstract

The present invention relates to a magnetic sensor. The demagnetization of the shielding plate in the plane parallel to the X-Y plane is small, and the shielding plate is easily magnetized by the magnetic field in the X-Y plane, and an induced magnetic field with a direction opposite to the direction of the external magnetic field can be generated, so that the external magnetic field can be cancelled. However, the demagnetization of the shielding plate in the Z-axis is large, and it is not easily magnetized by the magnetic field in the Z-axis direction. Therefore, the external magnetic field in the Z-axis direction can be smoothly turned by the turning column for detection by the first TMR component. It can be seen that by setting the soft magnetic structure, while detecting the Z-axis magnetic field, it can also shield the magnetic field in the X-Y plane, thereby avoiding cross-axis interference in the detection of the Z-axis magnetic field. In addition, the shielding plate and the turning column are arranged at intervals, so that the first TMR component and the adjustment layer can be arranged as close as possible, improving the magnetic reset and calibration effects of the adjustment layer on the magnetic sensor. In addition, the present invention also provides a method for manufacturing a magnetic sensor.

Description

Technical Field

[0001] The present invention relates to the technical field of sensors, and particularly to a magnetic sensor and a method for manufacturing the magnetic sensor. Background Art

[0002] A magnetic sensor is a device that converts magnetic property changes caused by a magnetic field into an electrical signal to detect changes in the ambient magnetic field. Magnetic sensors have been widely used in national defense construction, science and technology, and other fields. A tunneling magnetoresistance (TMR, Tunnel Magnetoresistance) sensor utilizes the tunneling magnetoresistance effect of a magnetic multi-layer film material to sense a magnetic field, and has higher precision compared to traditional magnetic sensors. TMR sensors have gradually become the mainstream in high-end application fields.

[0003] The magnetic field distribution in space is three-dimensional. However, the TMR magnetoresistance unit is only sensitive to the magnetic field in a plane. If an external out-of-plane magnetic field to be detected is converted into an in-plane magnetic field for detection, the external in-plane magnetic field may interfere with the detection of the TMR magnetoresistance unit, thereby affecting the detection accuracy. Summary of the Invention

[0004] Based on this, it is necessary to provide a magnetic sensor and a method for manufacturing the magnetic sensor that can improve the detection accuracy in view of the above problems.

[0005] A magnetic sensor includes:

[0006] A substrate;

[0007] A soft magnetic structure disposed on one side of the substrate. The soft magnetic structure includes a steering column and a shielding plate. The steering column and the shielding plate are spaced apart and extend in a direction perpendicular to the shielding plate;

[0008] An adjustment layer disposed between the steering column and the shielding plate. At least a part of the adjustment layer is set as a coil layer, and a magnetic field can be generated when the coil layer of the adjustment layer is energized; and

[0009] A plurality of first TMR components are disposed between the steering column and the shielding plate. The first TMR components are parallel to the shielding plate, and the positive projections of the plurality of first TMR components and the steering column on the plane where the surface of the shielding plate is located are within the range of the shielding plate.

[0010] In one embodiment, the substrate includes a CMOS board and a signal layer disposed on the CMOS board.

[0011] In one embodiment, a first passivation layer is formed on the surface of the substrate, and a first blind hole that does not penetrate in the thickness direction is formed in the first passivation layer; a steering column is formed in the first blind hole by a soft magnetic body; a second passivation layer covering the steering column is formed on the surface of the first passivation layer.

[0012] In one embodiment, a metal substrate layer is formed on the surface of the second passivation layer, and a plurality of magnetic tunnel junctions are disposed on the metal substrate layer; a third passivation layer covering the metal substrate layer and exposing the plurality of magnetic tunnel junctions is further formed on the surface of the second passivation layer; a first metal layer is formed on the surface of the third passivation layer; the plurality of magnetic tunnel junctions are connected in series through the metal substrate layer and the first metal layer to form a plurality of the first TMR components.

[0013] In one embodiment, a fourth passivation layer is formed on the surface of the third passivation layer, and an adjustment layer is formed on the surface of the fourth passivation layer.

[0014] In one embodiment, a fifth passivation layer covering the adjustment layer is formed on the surface of the fourth passivation layer, and a shielding plate formed by a soft magnetic body is formed on the surface of the fifth passivation layer.

[0015] In one embodiment, a first through hole penetrating in the thickness direction is formed in the first passivation layer, a soft magnetic layer formed by a soft magnetic body and extending to the substrate is formed in the first through hole; a second through hole exposing the soft magnetic layer is formed in the second passivation layer, a third through hole exposing the second through hole is formed in the third passivation layer, the first metal layer extends to the soft magnetic layer through the third through hole and the second through hole, and the plurality of the first TMR components are electrically connected to the substrate through the first metal layer and the soft magnetic layer; a fourth through hole exposing the first metal layer is formed in the fourth passivation layer, a second metal layer stacked with the first metal layer is formed in the fourth through hole, and the second metal layer, the first metal layer and the soft magnetic layer together form a signal communication structure electrically connected to the plurality of the first TMR components.

[0016] In one embodiment, the magnetic sensor further includes a plurality of second TMR components, the plurality of second TMR components are disposed on one side of the substrate, and the orthographic projection of the plurality of second TMR components in the plane of the substrate is located outside the orthographic projection range of the soft magnetic structure in the plane of the substrate.

[0017] For the above magnetic sensor, the demagnetization of the shielding plate in the direction parallel to the first TMR component (X-Y plane) is small, and the shielding plate is easily magnetized by the magnetic field in the X-Y plane. After the external magnetic field in the X-Y plane magnetizes the shielding plate, an induced magnetic field opposite to the direction of the external magnetic field can be generated, which can cancel out the external magnetic field and play a shielding role. The demagnetization of the shielding plate in the direction perpendicular to the first TMR component (Z-axis) is large, and the shielding plate is not easily magnetized by the magnetic field in the Z-axis direction. Therefore, the shielding plate does not affect the external magnetic field in the Z-axis direction to be detected, that is, the external magnetic field in the Z-axis direction to be detected will not be shielded by the shielding plate and can be smoothly steered by the steering column. It can be seen that by setting the soft magnetic structure, while detecting the Z-axis magnetic field, it can also shield the magnetic field in the X-Y plane, thus avoiding cross-axis interference in the detection of the Z-axis magnetic field. Therefore, the above magnetic sensor can significantly improve the detection accuracy.

[0018] Furthermore, when current flows through the coil layer of the adjustment layer, a magnetic field can be generated. The magnetic field generated by the coil layer can magnetize the free layer of the magnetic tunnel junction in the first TMR component, thereby realizing the magnetic reset of the magnetic sensor. In addition, the theoretical value of the magnetic field intensity generated by the coil layer can be calculated through parameters such as the number of coil turns and the magnitude of the current. On the premise that the ambient magnetic field is zeroed, by comparing the measured value of the above magnetic sensor with the theoretical value, the magnetic sensor can also be self-tested, thereby ensuring the precise measurement accuracy of the magnetic sensor.

[0019] A method for manufacturing a magnetic sensor includes:

[0020] Step S201: Form a steering column formed of a soft magnet on one side of the substrate;

[0021] Step S202: Form an adjustment layer and a plurality of first TMR components on the side of the steering column facing away from the substrate, and at least part of the adjustment layer is set as a coil layer;

[0022] Step S203: Form a shielding plate formed of a soft magnet on the side of the plurality of first TMR components and the adjustment layer facing away from the steering column. The shielding plate is parallel to the plurality of first TMR components, the steering column extends in a direction perpendicular to the shielding plate, and the orthographic projections of the plurality of first TMR components and the steering column on the plane where the surface of the shielding plate is located are within the range of the shielding plate.

[0023] In one embodiment, the step S201 includes: forming a first passivation layer on the surface of the substrate, and opening a first blind hole that does not penetrate in the thickness direction in the first passivation layer; depositing a soft magnet in the first blind hole to form the steering column in the first blind hole.

[0024] In one embodiment, the step S202 includes: forming a second passivation layer covering the steering column on the surface of the first passivation layer; sequentially forming a metal buffer layer and a TMR thin film on the surface of the second passivation layer; etching the TMR thin film to obtain a plurality of magnetic tunnel junctions; forming a third passivation layer covering the metal buffer layer and exposing the plurality of magnetic tunnel junctions on the surface of the second passivation layer; forming a first metal layer on the surface of the third passivation layer, and the plurality of magnetic tunnel junctions are connected in series through the metal buffer layer and the first metal layer to form a plurality of the first TMR components.

[0025] In one embodiment, the step S202 further includes: forming a fourth passivation layer on the surface of the third passivation layer; forming the adjustment layer on the surface of the fourth passivation layer.

[0026] In one embodiment, the step S203 includes: forming a fifth passivation layer covering the adjustment layer on the surface of the fourth passivation layer; depositing a soft magnetic body on the surface of the fifth passivation layer to form the shielding plate on the surface of the fifth passivation layer.

[0027] In one embodiment, when forming the first passivation layer on the surface of the substrate and forming a first blind hole that does not penetrate through in the thickness direction in the first passivation layer, a first through hole that penetrates through in the thickness direction is formed on the surface of the first passivation layer; when depositing a soft magnetic body in the first blind hole to form the steering column in the first blind hole, a soft magnetic layer extending to the substrate is formed by depositing a soft magnetic body in the first through hole; when forming the second passivation layer covering the steering column on the surface of the first passivation layer, a second through hole exposing the soft magnetic layer is formed in the second passivation layer; when forming the third passivation layer covering the metal buffer layer and exposing the plurality of magnetic tunnel junctions on the surface of the second passivation layer, a third through hole exposing the second through hole is formed in the third passivation layer; when forming the first metal layer on the surface of the third passivation layer, the first metal layer extends to the soft magnetic layer through the third through hole and the second through hole; when forming the fourth passivation layer on the surface of the third passivation layer, a fourth through hole exposing the first metal layer is formed in the fourth passivation layer; when forming the adjustment layer on the surface of the fourth passivation layer, a second metal layer stacked with the first metal layer is formed in the fourth through hole, and the second metal layer, the first metal layer, and the soft magnetic layer together form a signal communication structure.

[0028] In one embodiment, step S202 further includes: a plurality of the magnetic tunnel junctions are also connected in series through the metal substrate layer and the first metal layer to form a plurality of second TMR components, and the orthographic projections of the plurality of second TMR components in the plane of the substrate are located outside the range of the orthographic projection of the shielding plate in the plane of the substrate.

[0029] In the above method for manufacturing a magnetic sensor, the demagnetization of the shielding plate of the obtained magnetic sensor in the X-Y plane is small, and the shielding plate is easily magnetized by the magnetic field in the X-Y plane. When the external magnetic field in the X-Y plane magnetizes the shielding plate, an induced magnetic field opposite to the direction of the external magnetic field can be generated, so as to cancel the external magnetic field and play a shielding role. The demagnetization of the shielding plate in the Z-axis direction is large, and the shielding plate is not easily magnetized by the magnetic field in the Z-axis direction. Therefore, the shielding plate does not affect the external magnetic field in the Z-axis direction to be detected, that is, the external magnetic field in the Z-axis direction to be detected will not be shielded by the shielding plate and can be smoothly deflected by the steering column. It can be seen that by forming a steering column and a shielding plate made of a soft magnetic material, the magnetic sensor can shield the magnetic field in the X-Y plane while detecting the magnetic field in the Z-axis, thereby avoiding cross-axis interference in the detection of the magnetic field in the Z-axis.

[0030] Further, when current flows through the coil layer of the adjustment layer, a magnetic field can be generated. The magnetic field generated by the coil layer can magnetize the free layer of the magnetic tunnel junction in the first TMR component, thereby realizing the magnetic reset of the magnetic sensor. In addition, the theoretical value of the magnetic field intensity generated by the coil layer can be calculated through parameters such as the number of coil turns and the magnitude of the current. On the premise that the ambient magnetic field is zeroed, by comparing the measured value and the theoretical value of the above magnetic sensor, the magnetic sensor can be self-tested, thereby ensuring the precise measurement accuracy of the magnetic sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0032] Figure 1 is a schematic structural diagram of a magnetic sensor in an embodiment of the present invention;

[0033] Figure 2 is Figure 1 a simplified simulation schematic diagram of the magnetic sensor shown;

[0034] Figure 3 is a schematic flow chart of a method for manufacturing a magnetic sensor in an embodiment of the present invention;

[0035] Figure 4 For Figure 3 the schematic diagram of the scenario corresponding to step S201 in the method for manufacturing the magnetic sensor shown;

[0036] Figure 5 For Figure 3 the schematic diagram of the scenario corresponding to step S202 in the method for manufacturing the magnetic sensor shown;

[0037] Figure 6 For Figure 3 the schematic diagram of the scenario corresponding to step S203 in the method for manufacturing the magnetic sensor shown. Detailed implementation manners

[0038] To make the above objects, features, and advantages of the present invention more obvious and understandable, the following will describe the detailed implementation manners of the present invention with reference to the accompanying drawings. Many specific details are set forth in the following description to fully understand the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0039] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention.

[0040] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, "a plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0041] In the present invention, unless otherwise clearly defined or limited, terms such as "installed", "connected", "joined", "fixed", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0042] In the present invention, unless otherwise clearly defined or limited, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0043] It should be noted that when an element is referred to as "fixed to" or "disposed on" another element, it can be directly on the other element or there may also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used herein are only for the purpose of illustration and do not represent the only implementation.

[0044] Please refer to Figure 1 and Figure 2 , the magnetic sensor 100 in an embodiment of the present invention includes a substrate 110, a plurality of first TMR (Tunnel Magnetoresistance) components 120, a soft magnetic structure 130 and an adjustment layer 140.

[0045] The substrate 110 can support a plurality of first TMR components 120, a soft magnetic structure 130, and an adjustment layer 140. The plurality of first TMR components 120, the soft magnetic structure 130, and the adjustment layer 140 are all disposed on one side of the substrate 110. The first TMR component 120 can be composed of one or more series-connected magnetic tunnel junctions. A magnetic tunnel junction generally includes a ferromagnetic layer / a tunnel barrier layer / a ferromagnetic layer / an antiferromagnetic layer. The ferromagnetic layer below the tunnel barrier layer is also called the pinned layer, and the ferromagnetic layer above the tunnel barrier layer is also called the free layer. The exchange coupling effect between the pinned layer and the antiferromagnetic layer determines the magnetization direction of the pinned layer, and the change of the magnetic field in the environment will cause the magnetization direction of the free layer to change. When the magnetization directions of the two ferromagnetic layers are parallel to each other, the magnetic tunnel junction is in a low-resistance state; when the magnetization directions of the two ferromagnetic layers are antiparallel, the magnetic tunnel junction is in a high-resistance state. That is, the change of the magnetic field in the environment will cause the magnetization direction of the free layer to change, and then cause the resistance value of the magnetic tunnel junction to change, thereby causing the resistance value of the first TMR component 120 composed of the magnetic tunnel junction to change. The soft magnetic structure 130 cooperates with the plurality of first TMR components 120 to shield the external in-plane magnetic field and change the magnetic field direction of the external out-of-plane magnetic field to be detected to the in-plane direction for the plurality of first TMR components 120 to detect. The structures of the plurality of first TMR components 120 can be the same, and they can jointly detect the external out-of-plane magnetic field with the converted direction through series connection, parallel connection, or a combination of series connection and parallel connection. The adjustment layer 140 also cooperates with the plurality of first TMR components 120 to generate a magnetic field to adjust the plurality of first TMR components 120. The magnetic field can be a reset magnetic field to magnetically reset the plurality of first TMR components 120, or the magnetic field can be a self-test magnetic field to detect and calibrate the plurality of first TMR components 120.

[0046] In this embodiment, the magnetic sensor 100 further includes a signal communication structure 150. The plurality of first TMR components 120 are electrically connected to the signal communication structure 150. The analog signals generated by the plurality of first TMR components 120 detecting the external out-of-plane magnetic field with the converted direction can be output through the signal communication structure 150 to further process and generate digital signals. In addition, the adjustment layer 140 can also be electrically connected to the signal communication structure 150 and generate a corresponding magnetic field based on the adjustment signals transmitted by the signal communication structure 150.

[0047] In this embodiment, the substrate 110 includes a CMOS board 111 and a signal layer 112 covering the CMOS board 111. An integrated circuit composed of a number of MOS transistors is integrated in the CMOS board 111, which can process analog signals. The signal layer 112 can realize functions such as receiving analog signals and outputting digital signals. The signal layer 112 can be in the form of a metal layer, an integrated circuit layer, etc. Among them, the metal layer can be a copper layer, an aluminum layer, a copper alloy layer or an aluminum alloy layer. In this way, the analog signal can be transmitted to the substrate 110 and processed by the substrate 110 to obtain a digital signal reflecting the external out-of-plane magnetic field to be detected, thereby completing the detection of the external out-of-plane magnetic field. This digital signal can also be conducted to the outside of the magnetic sensor 100 through the signal communication structure 150 for convenient reading or calling.

[0048] By integrating the substrate 110 with the CMOS board 111 and the signal layer 112 in the magnetic sensor 100, the magnetic sensor 100 can be formed in a single-chip manner without the need to additionally integrate an ASIC chip for signal processing, which is beneficial to reducing the package size of the magnetic sensor 100.

[0049] Furthermore, in this embodiment, at least a part of the signal layer 112 is set as a coil layer. When a current flows through the coil layer, the coil layer can generate a magnetic field. The magnetic field of the coil layer can magnetize the free layer of the magnetic tunnel junction in the first TMR component 120, thereby realizing the magnetic reset of the magnetic sensor 100. Moreover, the theoretical value of the magnetic field intensity generated by the coil layer can be calculated through parameters such as the number of coil turns and the magnitude of the current. Therefore, by comparing the measured value of the magnetic sensor 100 with the theoretical value, the magnetic sensor 100 can also be self-checked to ensure the accuracy of the magnetic sensor 100.

[0050] Considering that multiple first TMR components 120 can only detect the in-plane magnetic field parallel to them and cannot detect the out-of-plane magnetic field perpendicular to them, therefore, the soft magnetic structure 130 is used to change the magnetic field direction of the external out-of-plane magnetic field to be detected to the in-plane direction for multiple first TMR components 120 to detect. Also, the soft magnetic structure 130 shields the external in-plane magnetic field to avoid the detection output caused by the external in-plane magnetic field. That is to say, the interference of the external in-plane magnetic field can be removed or greatly reduced by the soft magnetic structure 130, and the detection outputs generated by multiple first TMR components 120 only correspond to or basically correspond to the external out-of-plane magnetic field to be detected.

[0051] The soft magnetic structure 130 is formed of a soft magnetic material such as iron, iron-silicon alloy, ferrite, iron-nickel alloy, etc., and is easy to magnetize and demagnetize. The soft magnetic structure 130 includes a steering column 131 and a shielding plate 132. The steering column 131 is used to change the magnetic field direction of the external out-of-plane magnetic field to be detected to the in-plane direction, and the shielding plate 132 is used to shield the external in-plane magnetic field. The steering column 131 and the shielding plate 132 are arranged at intervals, and the adjustment layer 140 and a plurality of first TMR components 120 are arranged between the steering column 131 and the shielding plate 132. Among them, the steering column 131 extends in a direction perpendicular to the shielding plate 132, that is, perpendicular to the direction of the plurality of TMR components 120, and the shielding plate 132 is parallel to the plurality of first TMR components 120. The orthographic projections of the steering column 131 and the plurality of first TMR components 120 on the plane where the surface of the shielding plate 132 is located are within the range of the shielding plate 132.

[0052] The direction perpendicular to the first TMR component 120 is defined as the Z-axis direction, and the two directions parallel to the first TMR component 120 and perpendicular to each other are defined as the X-axis direction and the Y-axis direction. That is, the shielding plate 132 is parallel to the X-Y plane, the steering column 131 extends along the Z-axis direction, the orthographic projections of the steering column 131 and the plurality of first TMR components 120 in the X-Y plane are within the range of the orthographic projection of the shielding plate 132 in the X-Y plane, and the adjustment layer 140 and the plurality of first TMR components 120 are located between the shielding plate 132 and the steering column 131 in the Z-axis direction.

[0053] The steering column 131 has a three-dimensional shape and can be cylindrical, cuboid, or prismatic. For example Figure 2 As shown, the steering column 131 can change the magnetic field direction of the external out-of-plane magnetic field to be detected to the in-plane direction. Specifically, it can change the magnetic field direction of the external magnetic field in the Z-axis direction to be detected to the X-axis direction or the Y-axis direction. Since the deflection of the magnetic induction lines is more obvious at the edge position of the steering column 131, the plurality of first TMR components 120 are generally distributed along the circumference of the steering column 131 and are opposite to the edge of the steering column 131.

[0054] The thickness dimension of the shielding plate 132, that is, the dimension in the Z-axis direction, is small, generally less than 10 microns; while the length and width dimensions of the shielding plate 132, that is, the dimensions in the X-axis and Y-axis directions, are large, generally more than 100 microns. Therefore, the shielding plate 132 can be considered as a relatively large thin sheet. In this way, the demagnetization of the shielding plate 132 in the X-Y plane is small, and the shielding plate 132 is easily magnetized by the magnetic field in the X-Y plane; the demagnetization of the shielding plate 132 in the Z-axis direction is large, and the shielding plate 132 is not easily magnetized by the magnetic field in the Z-axis direction.

[0055] Based on the fact that the shielding plate 132 is easily magnetized by the magnetic field in the X-Y plane, the shielding plate 132 can shield the external magnetic field in the X-Y plane. Taking the example that an external magnetic field in the positive X-axis direction is applied above the shielding plate 132, the shielding plate 132 is easily magnetized by this magnetic field. After magnetization, the direction of the magnetic induction lines inside the shielding plate 132 is also in the positive X-axis direction. Considering that the magnetic induction lines are in a closed state, therefore, the direction of the magnetic induction lines below the shielding plate 132 should be in the negative X-axis direction. That is to say, an induced magnetic field with a direction opposite to the external magnetic field direction is generated below the shielding plate 132, so that it can cancel out the external magnetic field and play a shielding role. In addition, based on the fact that the shielding plate 132 is not easily magnetized by the magnetic field in the Z-axis direction, the shielding plate 132 does not affect the external magnetic field in the Z-axis direction to be detected. That is, the external magnetic field in the Z-axis direction to be detected will not be shielded by the shielding plate 132 and can be smoothly turned by the steering column 131.

[0056] In addition, it should be noted that the closer to the edge of the shielding plate 132, the weaker the shielding effect on the external magnetic field in the X-Y plane. In order to ensure the shielding effect on the external magnetic field in the X-Y plane, the distance between the edge of the orthographic projection of each first TMR component 120 on the surface of the shielding plate 132 and the edge of the shielding plate 132 is greater than or equal to 10 micrometers.

[0057] The adjustment layer 140 is at least partially arranged as a coil layer, and when the coil layer of the adjustment layer 140 is energized, a magnetic field can be generated. The magnetic field can be a reset magnetic field. The magnetic field of the coil layer of the adjustment layer 140 can magnetize the free layer of the magnetic tunnel junction in the first TMR component 120, so as to realize the magnetic reset of the magnetic sensor 100. The magnetic field can be a self-check magnetic field. The theoretical value of the magnetic field intensity generated by the coil layer can be calculated through parameters such as the number of coil turns and the magnitude of the current. Therefore, by comparing the measured value of the magnetic sensor 100 with the theoretical value, the magnetic sensor 100 can also be self-checked to ensure the accuracy of the magnetic sensor 100.

[0058] Moreover, both the adjustment layer 140 and the first TMR component 120 are located between the shielding plate 132 and the steering column 131. Therefore, the distance between the adjustment layer 140 and the first TMR component 120 is relatively close and the shielding is less. Therefore, the effect of magnetically resetting and calibrating the magnetic sensor 100 through the adjustment layer 140 is better.

[0059] In this embodiment, the adjustment layer 140 is located on the side of the plurality of first TMR components 120 facing away from the steering column 131, that is, the adjustment layer 140 is located between the plurality of first TMR components 120 and the shielding plate 132.

[0060] Such as Figure 4As shown, in this embodiment, a first passivation layer 160 is formed on the surface of the substrate 110. The first passivation layer 160 is provided with a first blind hole 161 that extends along the thickness direction of the first passivation layer 160 but does not penetrate; a steering column 131 is formed by a soft magnetic material within the first blind hole 161; a second passivation layer 170 covering the steering column 131 is formed on the surface of the first passivation layer 160.

[0061] The first passivation layer 160 serves as an insulating layer and protects the signal layer 112; the material and forming method of the second passivation layer 160 are generally the same as those of the first passivation layer 150, serving as an insulating layer and capable of protecting the steering column 131. The material of the first passivation layer 160 can be silicon oxide (SiO2), polyimide (PI), fluorine-containing silicon oxide (F-SiO2), aluminum oxide (AlOx), etc., and the first passivation layer 160 can be formed on the substrate 110 by means such as coating, physical vapor deposition (PVD), and chemical vapor deposition (CVD).

[0062] Furthermore, in this embodiment, the first passivation layer 160 is provided with a first through hole 162 that penetrates along the thickness direction. A soft magnetic layer 152 formed by a soft magnetic material and extending to the substrate 110 is formed within the first through hole 162; the second passivation layer 170 is provided with a second through hole 171 that exposes the soft magnetic layer 152.

[0063] Specifically, the soft magnetic layer 152 and the steering column 131 can be formed simultaneously. First, a seed layer is deposited, and then electroplating deposition of the soft magnetic material is carried out based on the seed layer. After electroplating deposition, the excess seed layer and soft magnetic material are etched away, such that the soft magnetic material filled within the first blind hole 161 constitutes the steering column 131, and the soft magnetic material filled within the first through hole 162 constitutes the soft magnetic layer 152. The soft magnetic layer 152 can be part of the signal communication structure 150 and can achieve electrical connection with the substrate 110.

[0064] As Figure 5 As shown, in this embodiment, a metal underlayer 121 is formed on the surface of the second passivation layer 170, and a plurality of magnetic tunnel junctions are disposed on the metal underlayer 121; a third passivation layer 180 covering the metal underlayer 121 and exposing the plurality of magnetic tunnel junctions is further formed on the surface of the second passivation layer 170; a first metal layer 151 is formed on the surface of the third passivation layer 180; the plurality of magnetic tunnel junctions are connected in series through the metal underlayer 121 and the first metal layer 151 to form a plurality of first TMR components 120.

[0065] The deposition of the metal underlayer 121 on the second passivation layer 170 can be formed by deposition followed by etching. The deposition of the first metal layer 151 on the third passivation layer 180 can also be formed by deposition followed by etching. The multiple magnetic tunnel junctions are connected in series through the metal underlayer 121 and the first metal layer 141 to form the first TMR component 120, and the series / parallel connection between the multiple TMR components 120 is also realized through the metal underlayer 121 and the first metal layer 141.

[0066] Furthermore, in this embodiment, the third passivation layer 180 is provided with a third through hole 181 that exposes the second through hole 171. The first metal layer 151 extends to the soft magnetic layer 152 through the third through hole 181 and the second through hole 171, and the multiple first TMR components 120 are electrically connected to the substrate 110 through the first metal layer 151 and the soft magnetic layer 152. It can be seen that a part of the first metal layer 151 is used to realize the series connection of the multiple magnetic tunnel junctions and the series / parallel connection of the multiple first TMR components 120, and the other part can be used as a part of the signal communication structure 150.

[0067] In this way, the analog signal generated by the magnetic field detection of the first TMR component 120 can be transmitted to the substrate 110 and processed by the substrate 110 to obtain a digital signal reflecting the external out-of-plane magnetic field to be detected, thereby completing the detection of the external out-of-plane magnetic field.

[0068] In this embodiment, a fourth passivation layer 190 is formed on the surface of the third passivation layer 180, and an adjustment layer 140 is formed on the surface of the fourth passivation layer 190. The fourth passivation layer 190 can be used for insulation and can protect the multiple first TMR components 120.

[0069] As Figure 6 shown, in this embodiment, a fifth passivation layer 1100 covering the adjustment layer 140 is formed on the surface of the fourth passivation layer 190, and a shielding plate 132 formed of a soft magnetic material is formed on the surface of the fifth passivation layer 1100.

[0070] The fifth passivation layer 1100 is also used for insulation and can protect the adjustment layer 140. Specifically, a seed layer is deposited on the surface of the fifth passivation layer 1100 first, and then electroplating deposition of the soft magnetic material is carried out based on the seed layer. After electroplating deposition, the redundant seed layer and soft magnetic material are etched away, so that the shielding plate 132 formed of the soft magnetic material is located on the surface of the fifth passivation layer 1100.

[0071] Further, in the present embodiment, the fourth passivation layer 190 is provided with a fourth through hole 191 exposing the first metal layer 151, and a second metal layer 153 stacked with the first metal layer 151 is formed in the fourth through hole 191. The second metal layer 153, the first metal layer 151, and the soft magnetic layer 152 together constitute a signal communication structure 150 electrically connected to the plurality of first TMR components 120.

[0072] When forming the adjustment layer 140 on the surface of the fourth passivation layer 190, the same process can be used to form the second metal layer 153 in the fourth through hole 191. That is to say, the material and forming method of the second metal layer 153 can be the same as those of the adjustment layer 140. After the same metal layer is deposited and then patterned, part of it constitutes the adjustment layer 140 and part of it constitutes the second metal layer 153. It can be seen that since the second metal layer 153 and the soft magnetic layer 152 can be formed in the same process as the adjustment layer 140 and the steering column 131 respectively, the forming of the signal communication structure 150 does not require additional processes, which helps to reduce the processing cost of the magnetic sensor 100.

[0073] Obviously, in other embodiments, the substrate 110 can also be provided with a connector for digital signal output by itself, so as to serve as the signal communication structure 150.

[0074] One end (soft magnetic layer 152) of the signal communication structure 150 is electrically connected to the substrate 110, and the other end (second metal layer 153) is exposed outside the magnetic sensor 100. Therefore, the digital signal reflecting the external out-of-plane magnetic field to be detected can also be conducted to the outside of the magnetic sensor 100 through the signal communication structure 150 for convenient reading or calling. Specifically, the fifth passivation layer 1100 is provided with a fifth through hole 1101 exposing the second metal layer 153.

[0075] In addition, in the present embodiment, a sixth passivation layer 1120 is formed on the surface of the fifth passivation layer 1100. The sixth passivation layer 1120 covers the shielding plate 132 and exposes the second metal layer 153. The sixth passivation layer 1120 can provide a protection effect on the shielding plate 132.

[0076] In the present embodiment, the magnetic sensor 100 further includes a plurality of second TMR components (not shown in the figure). The plurality of second TMR components are disposed on one side of the substrate 110, and the orthographic projection of the plurality of second TMR components in the plane of the substrate 110 is located outside the range of the orthographic projection of the soft magnetic structure 130 in the plane of the substrate 110.

[0077] The second TMR component is also composed of one or more magnetoresistive tunnel junctions connected in series. It can be understood that the second TMR component can be formed by the same process as the first TMR component 120. That is, multiple magnetoresistive tunnel junctions can be formed, with a part of the magnetoresistive tunnel junctions forming the first TMR component 120 and the other part forming the second TMR component. By setting the orthographic projection of the multiple second TMR components in the plane of the substrate 110 to be outside the range of the orthographic projection of the soft magnetic structure 130 in the plane of the substrate 110, the soft magnetic structure 130 has no effect on the multiple second TMR components, and thus the multiple second TMR components can detect the magnetic field in the external plane. Further, a part of the second TMR components is used to detect the X-axis magnetic field, and the other part is used to detect the Y-axis magnetic field.

[0078] The second TMR component is also electrically connected to the signal communication structure 150. The analog signal of the magnetic field in the external plane detected by the second TMR component can also be transmitted to the substrate 110 through the signal communication structure 150 and processed by the substrate 110 to obtain a digital signal reflecting the magnetic field in the external plane to be detected, thereby completing the detection of the magnetic field in the external plane. Moreover, the digital signal can also be conducted to the outside of the magnetic sensor 100 through the signal communication structure 150 for convenient reading or calling.

[0079] In the above magnetic sensor 100, the demagnetization of the shielding plate 132 in the direction parallel to the first TMR component 120 (X-Y plane) is small, and the shielding plate 132 is easily magnetized by the magnetic field in the X-Y plane. When the external magnetic field in the X-Y plane magnetizes the shielding plate 132, an induced magnetic field with a direction opposite to the external magnetic field direction can be generated, so as to cancel the external magnetic field and play a shielding role. The demagnetization of the shielding plate 132 in the direction perpendicular to the first TMR component 120 (Z axis) is large, and the shielding plate 132 is not easily magnetized by the magnetic field in the Z-axis direction. Therefore, the shielding plate 132 does not affect the external magnetic field in the Z-axis direction to be detected. That is, the external magnetic field in the Z-axis direction to be detected will not be shielded by the shielding plate 132 and can be smoothly deflected by the steering column 131. It can be seen that by setting the soft magnetic structure 130, while detecting the Z-axis magnetic field, it can also shield the magnetic field in the X-Y plane, thereby avoiding cross-axis interference in the detection of the Z-axis magnetic field. Therefore, the above magnetic sensor 100 can significantly improve the detection accuracy.

[0080] Further, when current flows through the coil layer of the adjustment layer 140, a magnetic field can be generated. The magnetic field can be a reset magnetic field. The magnetic field of the coil layer of the adjustment layer 140 can magnetize the free layer of the magnetic tunnel junction in the first TMR component 120, thereby realizing the magnetic reset of the magnetic sensor 100. The magnetic field can be a self-check magnetic field. The theoretical value of the magnetic field intensity generated by the coil layer can be obtained by calculating parameters such as the number of coil turns and the magnitude of the current. On the premise that the ambient magnetic field is zeroed, by comparing the measured value and the theoretical value of the magnetic sensor 100, the magnetic sensor 100 can be self-checked, thereby ensuring the precise measurement accuracy of the magnetic sensor 100.

[0081] In addition, the present invention also provides a method for manufacturing a magnetic sensor, which is used to process Figure 1 the magnetic sensor 100 shown.

[0082] Please refer to Figure 3 , the method for manufacturing a magnetic sensor in an embodiment of the present invention includes steps S201 to S203. Among them:

[0083] Step S201: Form a steering column 131 formed of a soft magnet on one side of the substrate 110.

[0084] Step S202: Form an adjustment layer 140 and a plurality of first TMR components 120 on the side of the steering column 131 facing away from the substrate 110. At least a part of the adjustment layer 140 is set as a coil layer.

[0085] Step S203: Form a shielding plate 132 formed of a soft magnet on the side of the plurality of first TMR components 120 and the adjustment layer 140 facing away from the steering column 131. The shielding plate 132 is parallel to the plurality of first TMR components 120. The steering column 131 extends in a direction perpendicular to the shielding plate 132. The orthographic projections of the plurality of first TMR components 120 and the steering column 131 on the plane where the surface of the shielding plate 132 is located are within the range of the shielding plate 132.

[0086] It should be noted that the above steps S201 to S203 can be executed sequentially, or can be executed synchronously under allowable conditions, or the execution order can be adjusted under allowable conditions.

[0087] The substrate 110 can support a plurality of first TMR components 120, a steering column 131, a shielding plate 132, and an adjustment layer 140. The steering column 131 and the shielding plate 132 together form a soft magnetic structure 130. The plurality of first TMR components 120, the soft magnetic structure 130, and the adjustment layer 140 are all disposed on one side of the substrate 110. The soft magnetic structure 130 cooperates with the plurality of first TMR components 120 to shield the external in-plane magnetic field and change the magnetic field direction of the external out-of-plane magnetic field to be detected to the in-plane direction for detection by the plurality of first TMR components 120. The structures of the plurality of first TMR components 120 can be the same, and they can jointly detect the external out-of-plane magnetic field with the changed direction by means of series connection, parallel connection, or a combination of series and parallel connections. The adjustment layer 140 also cooperates with the plurality of first TMR components 120 to generate a magnetic field to adjust the plurality of first TMR components 120. The magnetic field can be a reset magnetic field to magnetically reset the plurality of first TMR components 120, or it can be a self-test magnetic field to detect and calibrate the plurality of first TMR components 120.

[0088] In this embodiment, the substrate 110 includes a CMOS board 111 and a signal layer 112 covering the CMOS board 111. An integrated circuit composed of several MOS transistors is integrated in the CMOS board 111, which can process analog signals, and the signal layer 112 can realize functions such as receiving analog signals and outputting digital signals. The signal layer 112 can be in the form of a metal layer, an integrated circuit layer, etc. Among them, the metal layer can be a copper layer, an aluminum layer, a copper alloy layer, or an aluminum alloy layer.

[0089] In this way, the analog signal generated by the first TMR component 120 detecting the magnetic field can be transmitted to the substrate 110 and processed by the substrate 110 to obtain a digital signal reflecting the external out-of-plane magnetic field to be detected, thereby completing the detection of the external out-of-plane magnetic field. This digital signal can also be conducted outside the magnetic sensor 100 for convenient reading or calling.

[0090] By integrating the substrate 110 with the CMOS board 111 and the signal layer 112 on the magnetic sensor 100, the magnetic sensor 100 can be formed in a single-chip manner without the need to additionally integrate an ASIC chip for signal processing, which is beneficial to reducing the package size of the magnetic sensor 100.

[0091] Further, in this embodiment, at least a part of the signal layer 112 is set as a coil layer. When current flows through the coil layer, the coil layer can generate a magnetic field, and the magnetic field of the coil layer can magnetize the free layer of the magnetic tunnel junction in the first TMR component 120, thereby realizing the magnetic reset of the magnetic sensor 100. Moreover, the theoretical value of the magnetic field intensity generated by the coil layer can be obtained by calculating parameters such as the number of coil turns and the magnitude of the current. Therefore, by comparing the measured value of the magnetic sensor 100 with the theoretical value, the magnetic sensor 100 can also be self-checked to ensure the accuracy of the magnetic sensor 100.

[0092] The soft magnetic structure 130 is formed of a soft magnetic material such as iron, iron-silicon alloy, ferrite, iron-nickel alloy, etc., and is easy to magnetize and demagnetize. The steering column 131 constituting the soft magnetic structure 130 is disposed at an interval from the shielding plate 132, and the adjustment layer 140 and the plurality of first TMR components 120 are disposed between the steering column 131 and the shielding plate 132.

[0093] Please refer to Figure 4 simultaneously. The above step S201 includes: forming a first passivation layer 160 on the surface of the substrate 110, and opening a first blind hole 161 that does not penetrate in the thickness direction in the first passivation layer 160; depositing a soft magnetic body in the first blind hole 161 to form a steering column 131 in the first blind hole 161.

[0094] Specifically, the first passivation layer 160 can be formed on the substrate 110 by means such as coating, physical vapor deposition (PVD), chemical vapor deposition (CVD), etc. The material of the first passivation layer 160 can be silicon oxide (SiO2), polyimide (PI), fluorine-containing silicon oxide (F-SiO2), aluminum oxide (AlOx), etc. The first passivation layer 160 serves as an insulating layer and plays a protective role for the signal layer 112.

[0095] The formed steering column 131 has a three-dimensional shape and can be cylindrical, cuboid, or prismatic. As Figure 2 shown, the steering column 131 can change the magnetic field direction of the external out-of-plane magnetic field to be detected to the in-plane direction. Specifically, it can change the magnetic field direction of the external magnetic field in the Z-axis direction to be detected to the X-axis direction or the Y-axis direction. Since the deflection of the magnetic induction line is more obvious at the edge position of the steering column 131, generally, the plurality of first TMR components 120 are arranged in a circumferential distribution along the steering column 131 and are opposite to the edge of the steering column 131.

[0096] Further, in this embodiment, during the process of forming the first passivation layer 160 on the surface of the substrate 110 and forming the first blind hole 161 that does not penetrate through in the thickness direction in the first passivation layer 160, a first through hole 162 that penetrates through in the thickness direction is formed on the surface of the first passivation layer 160; during the process of depositing the soft magnetic material in the first blind hole 161 to form the steering column 131 in the first blind hole 161, the soft magnetic material is deposited in the first through hole 162 to form the soft magnetic layer 152 extending to the substrate 110 in the first through hole 162.

[0097] Specifically, the first through hole 162 can be formed in the same process as the first blind hole 161, or the first blind hole 161 and the second blind hole can be formed in the same process, and then the second blind hole is further penetrated through in the thickness direction to form the first through hole 162. The soft magnetic layer 152 can be formed in the same process as the steering column 131. When the soft magnetic layer 152 and the steering column 131 are formed simultaneously, first, the seed layer is deposited, and then electroplating deposition of the soft magnetic material is carried out based on the seed layer. After the electroplating deposition, the redundant seed layer and soft magnetic material are etched away, so that the soft magnetic material filled in the first blind hole 161 constitutes the steering column 131, and the soft magnetic material filled in the first through hole 162 constitutes the soft magnetic layer 152, and the soft magnetic layer 152 can achieve electrical connection with the substrate 110.

[0098] Please refer to Figure 5 simultaneously. In this embodiment, the above step S202 includes: forming a second passivation layer 170 covering the steering column 131 on the surface of the first passivation layer 160; sequentially forming a metal underlayer 121 and a TMR thin film 120a on the surface of the second passivation layer 170; etching the TMR thin film 120a to obtain a plurality of magnetic tunnel junctions; forming a third passivation layer 180 covering the metal underlayer 121 and exposing the plurality of magnetic tunnel junctions on the surface of the second passivation layer 170; forming a first metal layer 151 on the surface of the third passivation layer 180, and the plurality of magnetic tunnel junctions are connected in series through the metal underlayer 121 and the first metal layer 151 to form a plurality of first TMR components 120.

[0099] Specifically, the TMR thin film 120a is a multi-layer structure, generally including a ferromagnetic layer / tunnel barrier layer / ferromagnetic layer / antiferromagnetic layer, which is consistent with the layered structure of the magnetic tunnel junction. Among them, the antiferromagnetic layer is deposited on the metal underlayer, and then the ferromagnetic layer, the tunnel barrier layer, and the ferromagnetic layer are sequentially deposited. After the TMR thin film 120a is formed, patterning treatment is performed on the TMR thin film 120a to obtain a plurality of magnetic tunnel junctions.

[0100] The deposition of the metal underlayer 121 on the second passivation layer 170 can be formed by a method of first depositing and then etching. The deposition of the first metal layer 151 on the third passivation layer 180 can also be formed by a method of first depositing and then etching. Multiple magnetic tunnel junctions are connected in series through the metal underlayer 121 and the first metal layer 141 to form the first TMR component 120. Moreover, the series / parallel connection between multiple TMR components 120 is also realized through the metal underlayer 121 and the first metal layer 141. It can be seen that the processing efficiency of the first TMR component 120 is relatively high and the consistency between multiple first TMR components 120 is relatively good.

[0101] It should be noted that in other embodiments, multiple pre-formed first TMR components 120 can also be disposed on the second passivation layer 170 in a chip mounting manner.

[0102] Furthermore, in this embodiment, during the process of forming the second passivation layer 170 covering the steering column 131 on the surface of the first passivation layer 160, a second through hole 171 exposing the soft magnetic layer 152 is formed in the second passivation layer 170; during the process of forming the third passivation layer 180 covering the metal underlayer 121 and exposing multiple magnetic tunnel junctions on the surface of the second passivation layer 170, a third through hole 181 exposing the second through hole 171 is formed in the third passivation layer 180; during the process of forming the first metal layer 151 on the surface of the third passivation layer 180, the first metal layer 151 extends to the soft magnetic layer 152 through the third through hole 181 and the second through hole 171.

[0103] That is to say, a part of the first metal layer 151 is used to realize the series connection of multiple magnetic tunnel junctions and the series / parallel connection of multiple first TMR components 120, and the other part can serve as a bridge between multiple first TMR components 120 and the substrate 110, and electrically connect multiple first TMR components 120 to the substrate 110 through the first metal layer 151 and the soft magnetic layer 152. In this way, the analog signal generated by the magnetic field detection of the first TMR component 120 can be transmitted to the substrate 110 and processed by the substrate 110 to obtain a digital signal reflecting the external out-of-plane magnetic field to be detected, thereby completing the detection of the external out-of-plane magnetic field.

[0104] Before forming the third passivation layer 180, a photoresist 300 can be covered at the positions corresponding to the first TMR component 120 and the second through hole 171 by means of exposure, development and etching. After the third passivation layer 180 is formed, the photoresist is removed, and the first TMR component 120 and the second through hole 171 can be exposed.

[0105] In this embodiment, the above step S202 further includes: forming a fourth passivation layer 190 on the surface of the third passivation layer 180; forming an adjustment layer 140 on the surface of the fourth passivation layer 190. Specifically, the fourth passivation layer 190 can be used for insulation and can protect the plurality of first TMR components 120.

[0106] When the coil layer of the adjustment layer 140 is energized, a magnetic field can be generated, so that the free layer of the magnetic tunnel junction in the first TMR component 120 can be magnetized to realize the magnetic reset of the magnetic sensor 100, and the magnetic sensor 100 can be self-tested. Moreover, only the fourth passivation layer 190 is separated between the adjustment layer 140 and the first TMR component 120. Therefore, the distance between the adjustment layer 140 and the first TMR component 120 is relatively close and the shielding is less. Therefore, the effect of magnetic reset and calibration of the magnetic sensor 100 by the adjustment layer 140 is better.

[0107] Please refer to Figure 6 simultaneously. In this embodiment, the above step S203 includes: forming a fifth passivation layer 1100 covering the adjustment layer 140 on the surface of the fourth passivation layer 190; depositing a soft magnetic body on the surface of the fifth passivation layer 1100 to form a shielding plate 132 on the surface of the fifth passivation layer 1100.

[0108] The fifth passivation layer 1100 is also used for insulation and can protect the adjustment layer 140.

[0109] Depositing a soft magnetic body on the surface of the fifth passivation layer 1100 to form a shielding plate 132 on the surface of the fifth passivation layer 1100. Specifically, first deposit a seed layer on the surface of the fifth passivation layer 1100, and then perform electroplating deposition of the soft magnetic body based on the seed layer. After the electroplating deposition, etch away the excess seed layer and soft magnetic body, so that the soft magnetic body located on the surface of the fifth passivation layer 1100 constitutes the shielding plate 132.

[0110] It can be seen that the thickness dimension of the obtained shielding plate 132, that is, the dimension in the Z-axis direction is small; while the length and width dimensions of the shielding plate 132, that is, the dimensions in the X-axis and Y-axis directions are large. Therefore, the shielding plate 132 can be regarded as a quite large thin sheet. In this way, the demagnetization of the shielding plate 132 in the X-Y plane is small, and the shielding plate 132 is easily magnetized by the magnetic field in the X-Y plane; the demagnetization of the shielding plate 132 in the Z-axis direction is large, and the shielding plate 132 is not easily magnetized by the magnetic field in the Z-axis direction. Based on the fact that the shielding plate 132 is easily magnetized by the magnetic field in the X-Y plane, the shielding plate 132 can shield the external magnetic field in the X-Y plane.

[0111] Further, in this embodiment, during the process of forming the fourth passivation layer 190 on the surface of the third passivation layer 180, a fourth via hole 191 exposing the first metal layer 151 is formed in the fourth passivation layer 190; during the process of forming the adjustment layer 140 on the surface of the fourth passivation layer 190, a second metal layer 153 stacked with the first metal layer 151 is formed in the fourth via hole 191; the second metal layer 153, the first metal layer 151, and the soft magnetic layer 152 together constitute the signal communication structure 150.

[0112] Specifically, when forming the adjustment layer 140 on the surface of the fourth passivation layer 190, the same process can be used to form the second metal layer 153 in the fourth via hole 191. That is to say, the material and forming method of the second metal layer 153 can be the same as those of the adjustment layer 140. After the same metal layer is deposited and then patterned, part of it constitutes the adjustment layer 140 and part constitutes the second metal layer 153. It can be seen that since the second metal layer 153 and the soft magnetic layer 152 can be formed in the same process as the adjustment layer 140 and the steering column 131 respectively, the formation of the signal communication structure 150 does not require additional processes, which helps to reduce the processing cost of the magnetic sensor 100.

[0113] During the process of forming the fifth passivation layer 1100 covering the adjustment layer 140 on the surface of the fourth passivation layer 190, a fifth via hole 1101 exposing the second metal layer 153 is formed in the fifth passivation layer 1100. Since one end (soft magnetic layer 152) of the signal communication structure 150 is electrically connected to the substrate 110 and the other end (second metal layer 153) is exposed outside the magnetic sensor 100 through the fifth via hole 1101. Therefore, the digital signal reflecting the external out-of-plane magnetic field to be detected can also be conducted to the outside of the magnetic sensor 100 through the signal communication structure 150 for convenient reading or calling.

[0114] Obviously, in other embodiments, the substrate 110 can also be provided with a connector for digital signal output by itself, thus serving as the signal communication structure 150.

[0115] The above step S203 generally further includes the step of forming a sixth passivation layer 1120 on the surface of the fifth passivation layer 1100. The sixth passivation layer 1120 covers the shielding plate 132 and exposes the second metal layer 153. The sixth passivation layer 1120 can provide a protective effect on the shielding plate 132.

[0116] In addition, in this embodiment, the above step S202 further includes: a plurality of magnetic tunnel junctions are also connected in series through the metal substrate layer 121 and the first metal layer 151 to form a plurality of second TMR components, and the orthographic projection of the plurality of second TMR components in the plane of the substrate 110 is located outside the orthographic projection range of the shielding plate 132 in the plane of the substrate 110.

[0117] Specifically, the second TMR component can be formed using the same process as the first TMR component 120. That is, multiple magnetic tunnel junctions can be formed, with a part of the magnetic tunnel junctions constituting the first TMR component 120 and another part of the magnetic tunnel junctions constituting the second TMR component. The second TMR component is also composed of one or more magnetic tunnel junctions connected in series. By setting the orthographic projection of multiple second TMR components in the plane of the substrate 110 to be outside the range of the orthographic projection of the soft magnetic structure 130 in the plane of the substrate 110, the soft magnetic structure 130 has no effect on the multiple second TMR components, and thus the multiple second TMR components can detect the magnetic field in the external plane. Further, a part of the second TMR components is used to detect the X-axis magnetic field, and another part is used to detect the Y-axis magnetic field.

[0118] The second TMR component can also be set to be electrically connected to the signal communication structure 150. The analog signal of the magnetic field in the external plane detected by the second TMR component can also be transmitted to the substrate 110 through the signal communication structure 150 and processed by the substrate 110 to obtain a digital signal reflecting the magnetic field in the external plane to be detected, thereby completing the detection of the magnetic field in the external plane. Moreover, this digital signal can also be conducted to the outside of the magnetic sensor 100 through the signal communication structure 150 for convenient reading or calling.

[0119] In the above method for manufacturing a magnetic sensor, the demagnetization of the shielding plate 132 of the obtained magnetic sensor 100 in the X-Y plane is small, and the shielding plate 132 is easily magnetized by the magnetic field in the X-Y plane. When the external magnetic field in the X-Y plane magnetizes the shielding plate 132, an induced magnetic field with a direction opposite to the external magnetic field direction can be generated, so as to cancel the external magnetic field and play a shielding role. The demagnetization of the shielding plate 132 in the Z-axis is large, and the shielding plate 132 is not easily magnetized by the magnetic field in the Z-axis direction. Therefore, the shielding plate 132 does not affect the external magnetic field in the Z-axis direction to be detected. That is, the external magnetic field in the Z-axis direction to be detected will not be shielded by the shielding plate 132 and can be smoothly deflected by the steering column 131. It can be seen that by forming the steering column 131 and the shielding plate 132 made of soft magnetic materials, the magnetic sensor 100 can shield the magnetic field in the X-Y plane while detecting the magnetic field in the Z-axis, thereby avoiding cross-axis interference in the detection of the magnetic field in the Z-axis.

[0120] Further, a magnetic field can be generated when current flows through the coil layer of the adjustment layer 140. The magnetic field can be a reset magnetic field. The magnetic field of the coil layer of the adjustment layer 140 can magnetize the free layer of the magnetic tunnel junction in the first TMR component 120, thereby realizing the magnetic reset of the magnetic sensor 100. The magnetic field can be a self-check magnetic field. The theoretical value of the magnetic field intensity generated by the coil layer can be obtained by calculating parameters such as the number of coil turns and the magnitude of the current. On the premise that the ambient magnetic field is zeroed, by comparing the measured value and the theoretical value of the magnetic sensor 100, the magnetic sensor 100 can also be self-checked, so as to ensure the precise measurement accuracy of the magnetic sensor 100.

[0121] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered to be within the scope described in this specification.

[0122] The above-described embodiments merely represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent should be subject to the appended claims.

Claims

1. A magnetic sensor, characterized in that, Comprising: A substrate; A soft magnetic structure disposed on one side of the substrate, the soft magnetic structure including a steering column and a shielding plate, the steering column and the shielding plate being spaced apart and extending in a direction perpendicular to the shielding plate; An adjustment layer disposed between the steering column and the shielding plate, at least a part of the adjustment layer being configured as a coil layer, and a magnetic field being generated when the coil layer of the adjustment layer is energized; And A plurality of first TMR components disposed between the steering column and the shielding plate, the first TMR components being parallel to the shielding plate, and the positive projections of the plurality of first TMR components and the steering column in the plane of the surface of the shielding plate being within the range of the shielding plate. The distance between the edge of the positive projection of each first TMR component on the surface of the shielding plate and the edge of the shielding plate is greater than or equal to 10 micrometers.

2. The magnetic sensor according to claim 1, characterized in that, The substrate includes a CMOS board and a signal layer covering the CMOS board.

3. The magnetic sensor according to claim 1, wherein A first passivation layer is formed on the surface of the substrate, and a first blind hole that does not penetrate in the thickness direction is formed in the first passivation layer; the steering column is formed by a soft magnetic body in the first blind hole; a second passivation layer covering the steering column is formed on the surface of the first passivation layer.

4. The magnetic sensor according to claim 3, wherein A metal underlayer is formed on the surface of the second passivation layer, and a plurality of magnetic tunnel junctions are disposed on the metal underlayer; a third passivation layer covering the metal underlayer and exposing the plurality of magnetic tunnel junctions is further formed on the surface of the second passivation layer; A first metal layer is formed on the surface of the third passivation layer; the plurality of magnetic tunnel junctions are connected in series through the metal underlayer and the first metal layer to form the plurality of first TMR components.

5. The magnetic sensor according to claim 4, characterized in that, A fourth passivation layer is formed on the surface of the third passivation layer, and the adjustment layer is formed on the surface of the fourth passivation layer.

6. The magnetic sensor according to claim 5, characterized in that, A fifth passivation layer covering the adjustment layer is formed on the surface of the fourth passivation layer, and the shielding plate formed by a soft magnetic body is formed on the surface of the fifth passivation layer.

7. The magnetic sensor according to claim 5, wherein, A first through hole penetrating in the thickness direction is formed in the first passivation layer, and a soft magnetic layer formed by a soft magnetic body and extending to the substrate is formed in the first through hole; a second through hole exposing the soft magnetic layer is formed in the second passivation layer, a third through hole exposing the second through hole is formed in the third passivation layer, the first metal layer extends to the soft magnetic layer through the third through hole and the second through hole, and the plurality of first TMR components are electrically connected to the substrate through the first metal layer and the soft magnetic layer; a fourth through hole exposing the first metal layer is formed in the fourth passivation layer, and a second metal layer stacked with the first metal layer is formed in the fourth through hole. The second metal layer, the first metal layer, and the soft magnetic layer together constitute a signal communication structure electrically connected to the plurality of first TMR components.

8. The magnetic sensor according to any one of claims 1 to 7, characterized in that The magnetic sensor further includes a plurality of second TMR components, the plurality of second TMR components being disposed on one side of the substrate, and the positive projections of the plurality of second TMR components in the plane of the substrate being outside the range of the positive projection of the soft magnetic structure in the plane of the substrate.

9. A method for preparing a magnetic sensor, characterized in that, Comprising: Step S201: Form a steering column formed of a soft magnet on one side of the substrate; Step S202: Form an adjustment layer and a plurality of first TMR components on the side of the steering column facing away from the substrate, and at least part of the adjustment layer is provided as a coil layer; Step S203: Form a shielding plate formed of a soft magnet on the side of the plurality of first TMR components and the adjustment layer facing away from the steering column. The shielding plate is parallel to the plurality of first TMR components. The steering column extends in a direction perpendicular to the shielding plate. The positive projections of the plurality of first TMR components and the steering column in the plane of the surface of the shielding plate are within the range of the shielding plate.

10. The method for manufacturing a magnetic sensor according to claim 9, characterized in that, The step S201 includes: forming a first passivation layer on the surface of the substrate, and opening a first blind hole that does not penetrate in the thickness direction in the first passivation layer; depositing a soft magnet in the first blind hole to form the steering column in the first blind hole.

11. The method for manufacturing a magnetic sensor according to claim 10, wherein, The step S202 includes: forming a second passivation layer covering the steering column on the surface of the first passivation layer; sequentially forming a metal underlayer and a TMR thin film on the surface of the second passivation layer; etching the TMR thin film to obtain a plurality of magnetic tunnel junctions; forming a third passivation layer covering the metal underlayer and exposing the plurality of magnetic tunnel junctions on the surface of the second passivation layer; forming a first metal layer on the surface of the third passivation layer, and the plurality of magnetic tunnel junctions are connected in series through the metal underlayer and the first metal layer to form the plurality of first TMR components.

12. The method for manufacturing a magnetic sensor according to claim 11, wherein The step S202 further includes: forming a fourth passivation layer on the surface of the third passivation layer; forming the adjustment layer on the surface of the fourth passivation layer.

13. The method for preparing a magnetic sensor according to claim 12, wherein The step S203 includes: forming a fifth passivation layer covering the adjustment layer on the surface of the fourth passivation layer; depositing a soft magnet on the surface of the fifth passivation layer to form the shielding plate on the surface of the fifth passivation layer.

14. The method for manufacturing a magnetic sensor according to claim 13, wherein During the process of forming a first passivation layer on the surface of the substrate and opening a first blind hole that does not penetrate in the thickness direction in the first passivation layer, a first through hole that penetrates in the thickness direction is formed on the surface of the first passivation layer; during the process of depositing a soft magnet in the first blind hole to form the steering column in the first blind hole, a soft magnetic layer extending to the substrate is formed by depositing a soft magnet in the first through hole; during the process of forming a second passivation layer covering the steering column on the surface of the first passivation layer, a second through hole exposing the soft magnetic layer is opened on the second passivation layer; During the process of forming a third passivation layer covering the metal underlayer and exposing the plurality of magnetic tunnel junctions on the surface of the second passivation layer, a third through hole exposing the second through hole is opened on the third passivation layer; during the process of forming a first metal layer on the surface of the third passivation layer, the first metal layer extends to the soft magnetic layer through the third through hole and the second through hole; during the process of forming a fourth passivation layer on the surface of the third passivation layer, a fourth through hole exposing the first metal layer is opened on the fourth passivation layer; During the process of forming the adjustment layer on the surface of the fourth passivation layer, a second metal layer stacked with the first metal layer is formed in the fourth through hole, and the second metal layer, the first metal layer and the soft magnetic layer together constitute a signal communication structure.

15. The method for manufacturing a magnetic sensor according to claim 11, wherein The step S202 further includes: a plurality of the magnetic tunnel junctions are also connected in series through the metal substrate layer and the first metal layer to form a plurality of second TMR components, and the orthographic projections of the plurality of second TMR components on the plane where the substrate is located are outside the orthographic projection range of the shielding plate on the plane where the substrate is located.

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