TMR magnetic sensor and preparation method thereof

Abstract

The invention relates to a TMR magnetic sensor and a preparation method thereof, and the TMR magnetic sensor comprises the components of a substrate which comprises an inclined structure, and the inclined surface of the inclined structure is inclined between a second direction and a third direction; the first magnetic field sensitive area and the second magnetic field sensitive area are arranged on the substrate, and each of the first magnetic field sensitive area and the second magnetic field sensitive area is formed by connecting magnetic tunnel junctions in series or in parallel or in a mode of combining the series connection and the parallel connection; the magnetic tunnel junction located in the first magnetic field sensitive area is arranged on the plane of the substrate and has a pinning direction along the first direction; the magnetic tunnel junction located in the second magnetic field sensitive area is at least partially arranged on the inclined surface of the inclined structure, and the magnetic tunnel junction arranged on the inclined surface of the inclined structure has a pinning direction along the inclined surface of the inclined structure; the first direction, the second direction and the third direction are perpendicular to one another, and the third direction is further perpendicular to the plane of the substrate. A three-component magnetic field induction detection space magnetic field size and direction is formed, and three-axis magnetic field detection is realized.

Description

[0001] This application claims the priority of the Chinese patent application filed with the China Patent Office on January 31, 2024, with application number 202410140454.2, and invention name “TMR magnetic sensor and preparation method thereof”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the technical field of magnetic field sensing devices, and in particular to a TMR magnetic sensor and a preparation method thereof. Background Art

[0003] With the development of science and technology and the continuous progress of society, more and more types of magnetic sensors are appearing in people's daily work and life. TMR (Tunnel Magnetoresistance Effect) magnetic sensor is a magnetic sensitive element that uses the tunnel magnetoresistance effect. The external magnetic field can cause the resistance change of the TMR magnetoresistance element to detect the external magnetic field. However, the distribution of the external magnetic field is usually three-dimensional, and the TMR magnetoresistance element can only sense the magnetic field in the plane, which is difficult to meet the needs of measuring the three-axis magnetic field. Summary of the invention

[0004] Based on this, it is necessary to provide a TMR magnetic sensor and a preparation method thereof that can detect a three-axis magnetic field in order to address the above problems.

[0005] A TMR magnetic sensor, comprising:

[0006] a substrate, the substrate comprising an inclined structure, an inclined surface of the inclined structure being inclined between a second direction and a third direction;

[0007] A first magnetic field sensitive region and a second magnetic field sensitive region are arranged on the substrate, wherein the first magnetic field sensitive region and the second magnetic field sensitive region are both composed of magnetic tunnel junctions connected in series or in parallel or in combination of series and parallel; the magnetic tunnel junction located in the first magnetic field sensitive region is arranged in the plane of the substrate and has a pinning direction along a first direction; the magnetic tunnel junction located in the second magnetic field sensitive region is at least partially arranged on the inclined surface of the inclined structure, and the magnetic tunnel junction arranged on the inclined surface of the inclined structure has a pinning direction along the inclined surface of the inclined structure;

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

[0009] A method for preparing a TMR magnetic sensor, comprising:

[0010] Making an inclined structure on the substrate, wherein an inclined surface of the inclined structure is inclined between a second direction and a third direction;

[0011] A magnetic tunnel junction is formed on the substrate; the substrate is provided with a first magnetic field sensitive area and a second magnetic field sensitive area, and the first magnetic field sensitive area and the second magnetic field sensitive area are both composed of the magnetic tunnel junctions connected in series or in parallel or in a combination of series and parallel; the magnetic tunnel junction located in the first magnetic field sensitive area is arranged in the plane of the substrate and has a pinning direction along a first direction; the magnetic tunnel junction located in the second magnetic field sensitive area is at least partially arranged on the inclined surface of the inclined structure, and the magnetic tunnel junction arranged on the inclined surface of the inclined structure has a pinning direction along the inclined surface of the inclined structure;

[0012] The first direction, the second direction and the third direction are perpendicular to each other, and the third direction is also perpendicular to the plane of the substrate.

[0013] The above-mentioned TMR magnetic sensor and its preparation method, by providing a substrate with an inclined structure, the inclined surface of the inclined structure is inclined between the second direction and the third direction, and the magnetic tunnel junction of the first magnetic field sensitive area is arranged on the plane of the substrate, the magnetic tunnel junction of the second magnetic field sensitive area is at least partially arranged on the inclined surface of the inclined structure, the magnetic tunnel junction of the first magnetic field sensitive area has a pinning direction along the first direction, and the magnetic tunnel junction arranged on the inclined surface of the inclined structure has a pinning direction along the inclined surface of the inclined structure, forming a three-component magnetic field induction detection space magnetic field size and direction, to achieve three-axis magnetic field detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 A schematic diagram of the structure of a TMR magnetic sensor in one embodiment;

[0015] Figure 2 for Figure 1 Schematic diagram of the cross-sectional structure of the TMR magnetic sensor along A-A';

[0016] Figure 3 for Figure 1 Schematic diagram of the cross-sectional structure of the TMR magnetic sensor along B-B';

[0017] Figure 4 An equivalent circuit diagram of a full-bridge structure composed of an X-axis magnetic tunnel junction array in one embodiment;

[0018] Figure 5 A schematic diagram of the distribution and circuit connection of an X-axis magnetic tunnel junction array in one embodiment;

[0019] Figure 6 A schematic diagram of the arrangement of a Y-axis / Z-axis magnetic tunnel junction in one embodiment;

[0020] Figure 7An equivalent circuit diagram of a full-bridge structure composed of a Y-axis / Z-axis magnetic tunnel junction array in one embodiment;

[0021] Figure 8 A schematic diagram of the distribution and circuit connection of a Y-axis / Z-axis magnetic tunnel junction array in one embodiment;

[0022] Fig. 9 A schematic diagram of the structure of a TMR magnetic sensor in another embodiment;

[0023] Fig.10 for Fig. 9 Schematic diagram of the cross-sectional structure of the TMR magnetic sensor along A-A';

[0024] Fig.11 for Fig. 9 Schematic diagram of the cross-sectional structure of the TMR magnetic sensor along B-B';

[0025] Fig.12 An equivalent circuit diagram of a full-bridge structure composed of a Y-axis magnetic tunnel junction array in one embodiment;

[0026] Fig.13 A schematic diagram of the distribution and circuit connection of a Y-axis magnetic tunnel junction array in one embodiment;

[0027] Fig.14 A schematic diagram of the arrangement of a Z-axis magnetic tunnel junction in one embodiment;

[0028] Fig.15 An equivalent circuit diagram of a full-bridge structure composed of a Z-axis magnetic tunnel junction array in one embodiment;

[0029] Fig.16 A schematic diagram of the distribution and circuit connection of a Z-axis magnetic tunnel junction array in one embodiment;

[0030] Figure 17-Figure 31 Schematic diagram of the preparation process of a TMR magnetic sensor in one embodiment;

[0031] Figure 17-23 ,as well as Figure 32-Figure 43 FIG. 4 is a schematic structural diagram of the preparation process of a TMR magnetic sensor in another embodiment. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0034] In one embodiment, Figures 1 to 3 As shown, a TMR magnetic sensor is provided, including a substrate 110, and a first magnetic field sensitive area 120 and a second magnetic field sensitive area 130 arranged on the substrate 110. The substrate 110 includes an inclined structure, and the inclined surface of the inclined structure is inclined between the second direction and the third direction. The first magnetic field sensitive area 120 and the second magnetic field sensitive area 130 are both composed of magnetic tunnel junctions 140 connected in series or in parallel or in a combination of series and parallel; the magnetic tunnel junction 140 located in the first magnetic field sensitive area 120 is arranged on the plane of the substrate 110 and has a pinning direction along the first direction; the magnetic tunnel junction 140 located in the second magnetic field sensitive area 130 is at least partially arranged on the inclined surface of the inclined structure, and the magnetic tunnel junction 140 arranged on the inclined surface of the inclined structure has a pinning direction along the inclined surface of the inclined structure. Among them, the first direction, the second direction and the third direction are perpendicular to each other, and the third direction is also perpendicular to the plane of the substrate 110.

[0035] Specifically, the first direction and the second direction may be the X-axis direction and the Y-axis direction, or may be the Y-axis direction and the X-axis direction, respectively. The third direction is the Z-axis direction, and the plane of the substrate 110 is the XY plane. For ease of understanding, the following description is based on the example that the first direction, the second direction, and the third direction are the X-axis direction, the Y-axis direction, and the Z-axis direction, respectively.

[0036] The magnetic tunnel junction 140 generally includes a free layer / tunnel barrier layer / pinned layer. Changes in the external magnetic field will cause changes in the magnetization direction of the free layer. When the magnetization direction of the free layer is positively parallel to the pinning direction of the pinned layer, the magnetic tunnel junction 140 is in a low resistance state; when the magnetization direction of the free layer is anti-parallel to the pinning direction of the pinned layer, the magnetic tunnel junction 140 is in a high resistance state. It can be seen that the magnetic field component of the external magnetic field parallel to the pinning direction can cause a change in the magnetization direction of the free layer, and the parallel state with the pinning direction of the pinned layer can cause a change in the resistance value of the magnetic tunnel junction 140. By connecting the magnetic tunnel junction 140 in series or in parallel or in a combination of series and parallel, an electrical signal corresponding to the component of the external magnetic field in the pinning direction can be output.

[0037] The magnetic tunnel junction 140 of the first magnetic field sensitive region 120 is arranged on the plane of the substrate 110 and has a pinning direction along the X-axis direction. Therefore, the first magnetic field sensitive region 120 can be used to detect the magnetic field in the X-axis direction.

[0038] The magnetic tunnel junction 140 of the second magnetic field sensitive area 130 may be partially disposed on the plane of the substrate 110 and partially disposed on the inclined surface of the inclined structure; the magnetic tunnel junction 140 of the second magnetic field sensitive area 130 may also be entirely disposed on the inclined surface of the inclined structure. Since the inclined surface of the inclined structure is inclined between the Y-axis direction and the Z-axis direction, and the magnetic tunnel junction 140 disposed on the inclined surface of the inclined structure has a pinning direction along the inclined surface, the magnetic tunnel junction 140 disposed on the inclined surface of the inclined structure can sense an external magnetic field whose magnetic field direction is parallel to the inclined surface of the inclined structure. The external magnetic field whose magnetic field direction is parallel to the inclined surface of the inclined structure has a magnetic field component along the Y-axis direction and a magnetic field component along the Z-axis direction. Based on this, the magnetic tunnel junction 140 of the second magnetic field sensitive area 130 can detect magnetic fields in the Y-axis direction and the Z-axis direction.

[0039] The TMR magnetic sensor of the present embodiment is provided with a substrate 110 having an inclined structure, wherein the inclined surface of the inclined structure is inclined between the second direction and the third direction, and the magnetic tunnel junction 140 of the first magnetic field sensitive area 120 is provided on the plane of the substrate, and the magnetic tunnel junction 140 of the second magnetic field sensitive area 130 is at least partially provided on the inclined surface of the inclined structure, the magnetic tunnel junction 140 of the first magnetic field sensitive area 120 has a pinning direction along the first direction, and the magnetic tunnel junction 140 provided on the inclined surface of the inclined structure has a pinning direction along the inclined surface of the inclined structure, so that the first magnetic field sensitive area 120 can detect the magnetic field in the X-axis direction, and the second magnetic field sensitive area 130 can detect the magnetic field in the Y-axis direction and the Z-axis direction, that is, the TMR magnetic sensor of the present embodiment can realize the detection of the three-axis magnetic field.

[0040] The substrate 110 may include a substrate 112. The substrate 112 may include a CMOS wafer layer and a CMOS signal layer disposed on the CMOS wafer layer. The CMOS wafer layer is integrated with an integrated circuit composed of a plurality of MOS tubes, which can process the analog signal generated by the first magnetic field sensitive area 120 and the second magnetic field sensitive area 130 inducing the external magnetic field to obtain a digital signal, and the CMOS signal layer can realize functions such as receiving analog signals and outputting digital signals. The CMOS signal layer may be in the form of a metal layer, an integrated circuit layer, etc., wherein the metal layer may be a copper layer, an aluminum layer, a copper alloy layer or an aluminum alloy layer. By making the TMR magnetic sensor integrated with the substrate 112 having the CMOS wafer layer and the CMOS signal layer, the TMR magnetic sensor can be free of the need to integrate an additional chip for signal processing, which is conducive to reducing the package size of the TMR magnetic sensor.

[0041] Furthermore, the substrate 112 may also include a protective layer disposed on the CMOS signal layer to protect the CMOS signal layer. The material of the protective layer may be silicon oxide (SiO2) or aluminum oxide (AlO x )wait.

[0042] The inclined structure of the substrate 110 may be a groove or a protrusion, and accordingly, the inclined surface of the inclined structure is the inclined surface of the groove or the inclined surface of the protrusion.

[0043] The substrate 110 may further include a first passivation layer 114 disposed on the substrate 112, and the inclined structure is disposed on the first passivation layer 114. The material of the first passivation layer 114 may be silicon oxide (SiO2) or aluminum oxide (AlO x ) etc. A flat first passivation layer 114 may be first formed on the substrate 112, and then a groove may be formed on the first passivation layer 114 by etching; or a flat first passivation layer 114 may be first formed on the substrate 112, and then a protrusion may be formed on the first passivation layer 114 by etching, deposition or mounting.

[0044] The magnetic tunnel junctions 140 located in the first magnetic field sensitive region 120 can be arranged in an array, and the magnetic tunnel junctions 140 located in the second magnetic field sensitive region 130 can also be arranged in an array. The array layout can be made more compact, which is conducive to reducing the package size of the TMR magnetic sensor.

[0045] The magnetic tunnel junction 140 is disposed on the first passivation layer 114. Specifically, the magnetic tunnel junction 140 located in the first magnetic field sensitive region 120 is arranged on the plane of the first passivation layer 114; the magnetic tunnel junction 140 located in the second magnetic field sensitive region 130 is at least partially arranged on the inclined surface of the groove or protrusion.

[0046] A first metal layer may be provided on the side of the magnetic tunnel junction 140 close to the substrate 110, and a second metal layer may be provided on the side of the magnetic tunnel junction 140 away from the substrate 110. The first metal layer and the second metal layer are used to connect the magnetic tunnel junctions 140 in series to form a magnetoresistive unit, to be used for series / parallel connection between the magnetoresistive units, to connect the magnetoresistive unit to a power supply terminal or a ground setting, and to transmit the output signal (analog signal) of the bridge composed of the magnetoresistive units to the substrate 110.

[0047] Furthermore, if Figure 2 and Figure 3 As shown, the TMR magnetic sensor may further include a second passivation layer 180, and the material of the second passivation layer 180 may be the same as that of the first passivation layer 114. The second passivation layer 180 covers the magnetic tunnel junction 140, and the second passivation layer 180 serves as an insulating layer and protects the magnetic tunnel junction 140.

[0048] like Figures 1 to 3As shown, the TMR magnetic sensor also includes a coil 150 disposed on the substrate 110. The coil 150 is a multi-turn planar coil, which is used to reset each magnetic tunnel junction 140 in the first magnetic field sensitive area 120 and the second magnetic field sensitive area 130 when powered on, thereby reducing the noise of the TMR magnetic sensor, improving the detection accuracy, and reducing cross-axis interference and hysteresis.

[0049] Specifically, the portion of the coil 150 that transmits current along the X-axis direction is arranged corresponding to the first magnetic field sensitive area 120; the portion of the coil 150 that transmits current along the Y-axis direction is arranged corresponding to the second magnetic field sensitive area 130. When powered on, the coil 150 can generate a magnetic field perpendicular to the current direction, that is, the portion of the coil 150 that transmits current along the X-axis direction can generate a magnetic field in the Y-axis direction, and reset the magnetization direction of the free layer of the magnetic tunnel junction 140 of the first magnetic field sensitive area 120, so that the magnetization direction is along the Y-axis direction; the portion of the coil 150 that transmits current along the Y-axis direction can generate a magnetic field in the X-axis direction, and reset the magnetization direction of the free layer of the magnetic tunnel junction 140 of the second magnetic field sensitive area 130, so that the magnetization direction is along the X-axis direction.

[0050] like Figure 1As shown, the current in the coil 150 can be clockwise or counterclockwise. In addition, since the coil 150 is a planar coil composed of multiple turns of winding wire, the two parts of the coil 150 that are relatively arranged along the Y-axis direction have a current transmitted along the X-axis direction, and the two parts of the coil 150 that are relatively arranged along the X-axis direction have a current transmitted along the Y-axis direction. Combined with the corresponding relationship between the first magnetic field sensitive area 120, the second magnetic field sensitive area 130 and the direction of the current transmitted in the coil 150, and in order to make the layout more compact and effectively utilize the reset function of the coil 150, the number of the first magnetic field sensitive areas 120 is two, distributed along the Y-axis direction, and the number of the second magnetic field sensitive areas 130 is two, distributed along the X-axis direction, and distributed on both sides of the axis where the two first magnetic field sensitive areas 120 are located. In this way, the portion of the coil 150 that transmits current along the positive direction (+X) of the X axis and the portion that transmits current along the negative direction (-X) of the Y axis correspond to a first magnetic field sensitive area 120, respectively, and the portion that transmits current along the positive direction (+Y) of the Y axis and the portion that transmits current along the negative direction (-Y) of the Y axis correspond to a second magnetic field sensitive area 130, respectively. After the coil 150 is arranged on the substrate 110, the coil 150 is energized to generate a magnetic field component perpendicular to the current direction. The magnetic field component generated by the coil 150 in the first magnetic field sensitive area 120 is in the positive direction and negative direction of the Y axis, and the magnetic field component generated in the second magnetic field sensitive area 130 is in the positive direction and negative direction of the X axis. After the coil 150 is energized, the magnetic tunnel junctions 140 in the two first magnetic field sensitive areas 120 and the two second magnetic field sensitive areas 130 can be reset by using the portions with different current directions to determine the initial magnetization direction of the free layer of the magnetic tunnel junction 140, and the operation is simple and quick.

[0051] The coil 150 may be disposed above or below the magnetic tunnel junction 140. When the coil 150 is disposed below the magnetic tunnel junction 140, at least a portion of the CMOS signal layer may be used as the coil 150. When the coil 150 is disposed above the magnetic tunnel junction 140, a metal layer may be disposed on the second passivation layer 180 and etched to form the coil 150.

[0052] like Figure 4 and Figure 5As shown, a portion of the magnetic tunnel junction 140 located in the first magnetic field sensitive region 120 has a pinning direction along the positive direction (+X) of the X-axis, and another portion has a pinning direction along the negative direction (-X) of the X-axis. A portion of the magnetic tunnel junction 140 having a pinning direction along the positive direction (+X) of the X-axis is connected in series to form a magnetoresistive unit R11, and another portion is connected in series to form a magnetoresistive unit R13; a portion of the magnetic tunnel junction 140 having a pinning direction along the negative direction (-X) of the X-axis is connected in series to form a magnetoresistive unit R12, and another portion is connected in series to form a magnetoresistive unit R14. The pinning direction of the magnetic tunnel junction 140 can be determined by the annealing magnetic field. Specifically, the magnetic tunnel junction 140 constituting the magnetoresistive unit R11 and the magnetoresistive unit R13 is annealed in the positive direction of the X-axis, and the magnetic tunnel junction 140 constituting the magnetoresistive unit R12 and the magnetoresistive unit R14 is annealed in the negative direction of the X-axis. The magnetic tunnel junctions 140 that need to be annealed in the same direction can be arranged in the same area. For example, the magnetic tunnel junctions 140 constituting the magnetoresistive unit R11 and the magnetoresistive unit R13 are arranged in the same area, and the magnetic tunnel junctions 140 constituting the magnetoresistive unit R12 and the magnetoresistive unit R14 are arranged in another same area. The magnetic tunnel junctions 140 that need to be annealed in different directions can also be arranged in the same area based on other requirements, for example, to facilitate the circuit connection or magnetic reset between the magnetoresistive units, for example, the magnetic tunnel junctions 140 constituting the magnetoresistive unit R11 and the magnetoresistive unit R14 are arranged in the same area, and the magnetic tunnel junctions 140 constituting the magnetoresistive unit R12 and the magnetoresistive unit R13 are arranged in another same area. When the same area needs to be annealed in different directions, local laser annealing can be used.

[0053] The magnetoresistance units R11 and R14 have initial magnetization directions of the free layers in the positive direction of the Y-axis direction, and the magnetoresistance units R12 and R13 have initial magnetization directions of the free layers in the negative direction of the Y-axis direction. By arranging the magnetic tunnel junctions 140 constituting the magnetoresistance units R11 and R14 at the portion of the coil 150 that transmits current in the positive direction (+X) of the X-axis, and arranging the magnetic tunnel junctions 140 constituting the magnetoresistance units R12 and R13 at the portion of the coil 150 that transmits current in the negative direction (-X) of the X-axis, when the coil 150 is powered on, the magnetization direction of the free layer of the magnetic tunnel junctions 140 of the first magnetic field sensitive region 120 can be magnetically reset accordingly.

[0054] One end of the magnetoresistance unit R11 is connected to the output terminal P1, and the other end of the magnetoresistance unit R11 is connected to the power supply terminal VCC1; one end of the magnetoresistance unit R14 is connected to the output terminal N1, and the other end of the magnetoresistance unit R14 is connected to the power supply terminal VCC1; one end of the magnetoresistance unit R12 is connected to the output terminal P1, and the other end of the magnetoresistance unit R12 is connected to the ground terminal GND; one end of the magnetoresistance unit R13 is connected to the output terminal N1, and the other end of the magnetoresistance unit R13 is connected to the ground terminal GND.

[0055] Specifically, Figure 4 The hollow arrow indicates the pinning direction of the magnetic tunnel junction 140, and the solid arrow indicates the initial magnetization direction of the free layer of the magnetic tunnel junction 140. When preparing the magnetic tunnel junction 140, the magnetic tunnel junction 140 used to form the magnetoresistive unit R11 and the magnetoresistive unit R13 is annealed along the positive direction of the X-axis to generate a pinning direction along the positive direction of the X-axis; the magnetic tunnel junction 140 used to form the magnetoresistive unit R12 and the magnetoresistive unit R14 is annealed along the negative direction of the X-axis to generate a pinning direction along the negative direction of the X-axis. Figure 5 As shown, when the sensor is working, the direction of the coil current in the area where the magnetoresistance unit R11 and the magnetoresistance unit R14 are located is along the positive direction of the X-axis, generating a setting magnetic field along the positive direction of the Y-axis. The direction of the coil current in the area where the magnetoresistance unit R12 and the magnetoresistance unit R13 are located is along the negative direction of the X-axis, generating a setting magnetic field along the negative direction of the Y-axis. Therefore, the magnetoresistance unit R11 and the magnetoresistance unit R14 have the same initial magnetization direction of the free layer, both in the positive direction of the Y-axis, and the magnetoresistance unit R12 and the magnetoresistance unit R13 have the same initial magnetization direction of the free layer, both in the negative direction of the Y-axis.

[0056] When the sensor is working, when the external magnetic field has a component along the X-axis, the magnetization direction of the free layer of the magnetic tunnel junction 140 produces different rotation angles depending on the magnitude of the magnetic field component, causing the resistance of the magnetoresistive unit R11 / magnetoresistive unit R13 to increase or decrease. The resistance change of the magnetoresistive unit R12 / magnetoresistive unit R14 is opposite to the resistance change of the magnetoresistive unit R11 / magnetoresistive unit R13. The differential signal S1 of the X-axis bridge produces an approximately linear change relationship with the X-axis component of the external magnetic field, as shown in the following formula:

[0057]

[0058] Among them, MR and H k represents the intrinsic properties of the magnetic tunnel junction 140, which are magnetoresistivity and anisotropy field; V P1 Represents the output signal of output terminal P1, V N1 represents the output signal of the output terminal N1; Hx represents the X-axis component of the external magnetic field.

[0059] In one embodiment, all magnetic tunnel junctions 140 in the second magnetic field sensitive region 130 are arranged on the inclined surface of the inclined structure. All magnetic tunnel junctions 140 in the second magnetic field sensitive region 130 are arranged on the inclined surface of the groove / protrusion of the substrate 110 to detect the magnetic field of the Y axis and the Z axis.

[0060] like Figures 6 to 8As shown, the magnetic tunnel junction 140 located in the second magnetic field sensitive area 130 has a pinning direction along the inclined surface of the inclined structure, wherein the magnetic tunnel junction 140 with the pinning direction along the inclined surface of the inclined structure in the positive upward direction is partially connected in series to form a magnetoresistance unit R21 and partially connected in series to form a magnetoresistance unit R23, the magnetic tunnel junction 140 with the pinning direction along the inclined surface of the inclined structure in the negative downward direction is partially connected in series to form a magnetoresistance unit R22 and partially connected in series to form a magnetoresistance unit R24, the magnetic tunnel junction 140 with the pinning direction along the inclined surface of the inclined structure in the positive downward direction is partially connected in series to form a magnetoresistance unit R31 and partially connected in series to form a magnetoresistance unit R33, and the magnetic tunnel junction 140 with the pinning direction along the inclined surface of the inclined structure in the negative upward direction is partially connected in series to form a magnetoresistance unit R32 and partially connected in series to form a magnetoresistance unit R34. The magnetoresistance units R22, R23, R32 and R33 have free layer initial magnetization directions in the positive direction of the X-axis direction, and the magnetoresistance units R21, R24, R31 and R34 have free layer initial magnetization directions in the negative direction of the X-axis direction.

[0061] One end of the magnetoresistance unit R21 is connected to the output terminal P2, and the other end of the magnetoresistance unit R21 is connected to the power supply terminal VCC2. One end of the magnetoresistance unit R24 is connected to the output terminal N2, and the other end of the magnetoresistance unit R24 is connected to the power supply terminal VCC2. One end of the magnetoresistance unit R22 is connected to the output terminal P2, and the other end of the magnetoresistance unit R22 is connected to the ground terminal GND. One end of the magnetoresistance unit R23 is connected to the output terminal N2, and the other end of the magnetoresistance unit R23 is connected to the ground terminal GND. One end of the magnetoresistance unit R31 is connected to the output terminal P3, and the other end of the magnetoresistance unit R31 is connected to the power supply terminal VCC3. One end of the magnetoresistance unit R34 is connected to the output terminal N3, and the other end of the magnetoresistance unit R34 is connected to the power supply terminal VCC3. One end of the magnetoresistance unit R32 is connected to the output terminal P3, and the other end of the magnetoresistance unit R32 is connected to the ground terminal GND. One end of the magnetoresistance unit R33 is connected to the output terminal N3, and the other end of the magnetoresistance unit R33 is connected to the ground terminal GND.

[0062] Specifically, Figure 6 and Figure 8 As shown, taking the inclined structure as an example of a groove arranged in the substrate 110, along the positive direction of the Y axis, the magnetic tunnel junction 140 for constituting the magnetoresistive unit R31 (magnetoresistive unit R33) and the magnetoresistive unit R32 (magnetoresistive unit R34) is arranged on the downslope of the groove, and the magnetic tunnel junction 140 for constituting the magnetoresistive unit R21 (magnetoresistive unit R23) and the magnetoresistive unit R22 (magnetoresistive unit R24) is arranged on the upslope of the groove, and the downslope of the groove ( Figure 8 The slope shown 2) and the uphill slope ( Figure 8The slopes of the inclined surfaces 1) shown in the figure are the same. The magnetic tunnel junctions 140 used to form the magnetoresistive unit R31 (magnetoresistive unit R33) and the magnetoresistive unit R21 (magnetoresistive unit R23) are annealed along the positive direction of the Y axis, so that the pinning direction generated by the magnetoresistive unit R31 (magnetoresistive unit R33) includes the positive direction component of the Y axis and the negative direction component of the Z axis, and the pinning direction generated by the magnetoresistive unit R21 (magnetoresistive unit R23) includes the positive direction component of the Y axis and the positive direction component of the Z axis. The magnetic tunnel junctions 140 used to form the magnetoresistive unit R22 (magnetoresistive unit R24) and the magnetoresistive unit R32 (magnetoresistive unit R34) are annealed along the negative direction of the Y axis, so that the pinning direction generated by the magnetoresistive unit R22 (magnetoresistive unit R24) includes the negative direction component of the Y axis and the negative direction component of the Z axis, and the pinning direction generated by the magnetoresistive unit R32 (magnetoresistive unit R34) includes the negative direction component of the Y axis and the positive direction component of the Z axis.

[0063] Figure 7 The hollow arrow indicates the component of the pinning direction of the magnetic tunnel junction 140 in the Y-axis, and the solid arrow indicates the initial magnetization direction of the free layer of the magnetic tunnel junction 140. The pinning directions of the magnetoresistive unit R21 / magnetoresistive unit R23 / magnetoresistive unit R31 / magnetoresistive unit R33 have a component along the positive direction of the Y-axis; the pinning directions of the magnetoresistive unit R22 / magnetoresistive unit R24 / magnetoresistive unit R32 / magnetoresistive unit R34 have a component along the negative direction of the Y-axis. In this way, the induction outputs of the two bridges for the Y-axis magnetic field are the same.

[0064] Furthermore, Figure 7 In the left bridge, the pinning directions of magnetoresistance unit R21 / magnetoresistance unit R24 / magnetoresistance unit R22 / magnetoresistance unit R23 have components along +Z / -Z / +Z / -Z respectively. In the right bridge, the pinning directions of magnetoresistance unit R31 / magnetoresistance unit R34 / magnetoresistance unit R32 / magnetoresistance unit R33 have components along -Z / +Z / -Z / +Z respectively. In this way, the induced outputs of the two bridges for the Z-axis magnetic field are the same in magnitude but opposite in direction.

[0065] like Figure 8 As shown, when the sensor is working, the coil current direction of the area where the magnetoresistance unit R21 / magnetoresistance unit R24 / magnetoresistance unit R31 / magnetoresistance unit R34 is located is along the positive direction of the Y axis, generating a setting magnetic field along the negative direction of the X axis, and the coil current direction of the area where the magnetoresistance unit R23 / magnetoresistance unit R22 / magnetoresistance unit R33 / magnetoresistance unit R32 is located is along the negative direction of the Y axis, generating a setting magnetic field along the positive direction of the X axis. Therefore, the magnetoresistance unit R21 / magnetoresistance unit R24 / magnetoresistance unit R31 / magnetoresistance unit R34 have the same initial magnetization direction of the free layer, which is the negative direction of the X axis, and the magnetoresistance unit R23 / magnetoresistance unit R22 / magnetoresistance unit R33 / magnetoresistance unit R32 have the same initial magnetization direction of the free layer, which is the positive direction of the X axis.

[0066] When the sensor is working, when the external magnetic field has a component along the Y axis and / or the Z axis, the magnetization direction of the free layer of the magnetic tunnel junction 140 produces different rotation angles depending on the magnitude of the magnetic field component. Under the action of the Y axis magnetic field, the resistance of the magnetoresistive unit R21 / magnetoresistive unit R23 and the magnetoresistive unit R31 / magnetoresistive unit R33 increases or decreases, and the resistance of the magnetoresistive unit R22 / magnetoresistive unit R24 and the magnetoresistive unit R32 / magnetoresistive unit R34 changes, which are respectively related to the magnetoresistive unit R21 / magnetoresistive unit R23 and the magnetoresistive unit R31 / magnetoresistive unit R33. The resistance changes of magnetoresistance unit R23 and magnetoresistance unit R31 / magnetoresistance unit R33 are opposite; under the action of the Z-axis magnetic field, the resistance of magnetoresistance unit R21 / magnetoresistance unit R23 and magnetoresistance unit R32 / magnetoresistance unit R34 increases or decreases, and the resistance changes of magnetoresistance unit R22 / magnetoresistance unit R24 and magnetoresistance unit R31 / magnetoresistance unit R33 are opposite to the resistance changes of magnetoresistance unit R21 / magnetoresistance unit R23 and magnetoresistance unit R32 / magnetoresistance unit R34, respectively. Figure 7 In the figure, the differential signal S2 of the left Y / Z-axis bridge and the differential signal S3 of the right Y / Z-axis bridge have an approximately linear relationship with the Y-axis component and the Z-axis component of the external magnetic field, as shown in the following formula:

[0067]

[0068] Among them, MR and H k represents the intrinsic properties of the magnetic tunnel junction 140, which are magnetoresistivity and anisotropy field; V P2 、V P3 Respectively represent the output signals of output terminal P2 and output terminal P3, V N2 、V N3 They represent the output signals of the output terminal N2 and the output terminal N3 respectively; Hy and Hz represent the Y-axis component and the Z-axis component of the external magnetic field respectively; and θ represents the inclination angle of the inclined surface of the inclined structure relative to the plane of the substrate 110 .

[0069] As can be seen from the above, the signal of S2+S3 has a linear change relationship with the Y-axis magnetic field component, and the signal of S2-S3 has a linear change relationship with the Z-axis magnetic field component. That is, the Y-axis magnetic field component can be analyzed according to the sum of the differential signal S2 and the differential signal S3, and the Z-axis magnetic field component can be analyzed according to the difference between the differential signal S2 and the differential signal S3.

[0070] In another embodiment, Figure 9-11As shown, the magnetic tunnel junction 140 for detecting the magnetic field in the second direction in the second magnetic field sensitive area 130 is arranged on the plane of the substrate 110; the magnetic tunnel junction 140 for detecting the magnetic field in the third direction in the second magnetic field sensitive area 130 is arranged on the inclined surface of the inclined structure. Specifically, the magnetic tunnel junction 140 of the first magnetic field sensitive area 120 is arranged on the plane of the substrate 110, has a pinning direction along the X-axis direction, and detects the magnetic field in the X-axis direction. The second magnetic field sensitive area 130 can be divided into a Y-sensitive area and a Z-sensitive area. The magnetic tunnel junction 140 in the Y-sensitive area is arranged on the plane of the substrate 110, has a pinning direction along the Y-axis direction, and detects the magnetic field in the Y-axis direction. The magnetic tunnel junction 140 in the Z-sensitive area is arranged on the inclined surface of the inclined structure, has a pinning direction along the inclined surface of the inclined structure, and detects the magnetic field in the Z-axis direction.

[0071] In one embodiment, Fig.12 and Fig.13 As shown, in the magnetic tunnel junction 140 located in the second magnetic field sensitive area 130 for detecting the magnetic field in the Y-axis direction, a part of the magnetic tunnel junction 140 having a pinning direction along the positive direction of the Y-axis direction is connected in series to form a magnetoresistance unit R25, and another part is connected in series to form a magnetoresistance unit R27; a part of the magnetic tunnel junction 140 having a pinning direction along the negative direction of the Y-axis direction is connected in series to form a magnetoresistance unit R26, and another part is connected in series to form a magnetoresistance unit R28; the magnetoresistance unit R25 and the magnetoresistance unit R28 have the initial magnetization direction of the free layer along the positive direction of the X-axis direction, and the magnetoresistance unit R26 and the magnetoresistance unit R27 have the initial magnetization direction of the free layer along the negative direction of the X-axis direction. One end of the magnetoresistance unit R25 is connected to the output terminal P4, and the other end of the magnetoresistance unit R25 is connected to the power supply terminal VCC4; one end of the magnetoresistance unit R28 is connected to the output terminal N4, and the other end of the magnetoresistance unit R28 is connected to the power supply terminal VCC4; one end of the magnetoresistance unit R26 is connected to the output terminal P4, and the other end of the magnetoresistance unit R26 is connected to the ground terminal GND; one end of the magnetoresistance unit R27 is connected to the output terminal N4, and the other end of the magnetoresistance unit R27 is connected to the ground terminal GND.

[0072] Specifically, Fig.12 The hollow arrow indicates the pinning direction of the magnetic tunnel junction 140, and the solid arrow indicates the initial magnetization direction of the free layer of the magnetic tunnel junction 140. When preparing the magnetic tunnel junction 140, the magnetic tunnel junctions 140 constituting the magnetoresistive unit R25 and the magnetoresistive unit R27 are subjected to regional annealing along the positive direction of the Y axis to generate a pinning direction along the positive direction of the Y axis; the magnetic tunnel junctions 140 constituting the magnetoresistive unit R26 and the magnetoresistive unit R28 are subjected to regional annealing along the negative direction of the Y axis to generate a pinning direction along the negative direction of the Y axis. Fig.13As shown, when the sensor is working, the coil current direction of the area where the magnetoresistance unit R25 and the magnetoresistance unit R28 are located is along the negative direction of the Y axis, generating a setting magnetic field along the positive direction of the X axis, and the coil current direction of the area where the magnetoresistance unit R27 and the magnetoresistance unit R26 are located is along the positive direction of the Y axis, generating a setting magnetic field along the negative direction of the X axis. Therefore, the magnetoresistance unit R25 and the magnetoresistance unit R28 have the same initial magnetization direction of the free layer, both in the positive direction of the X axis, and the magnetoresistance unit R27 and the magnetoresistance unit R26 have the same initial magnetization direction of the free layer, both in the negative direction of the X axis.

[0073] When the sensor is working, when the external magnetic field has a component along the Y axis, the magnetization direction of the free layer of the magnetic tunnel junction 140 produces different rotation angles depending on the magnitude of the magnetic field component, causing the resistance of the magnetoresistive unit R25 / magnetoresistive unit R27 to increase or decrease. The resistance change of the magnetoresistive unit R26 / magnetoresistive unit R28 is opposite to the resistance change of the magnetoresistive unit R25 / magnetoresistive unit R27. The differential signal S4 of the Y-axis bridge produces an approximately linear change relationship with the Y-axis component of the external magnetic field, as shown in the following formula:

[0074]

[0075] Among them, MR and H k represents the intrinsic properties of the magnetic tunnel junction 140, which are magnetoresistivity and anisotropy field; V P4 Represents the output signal of output terminal P4, V N4 represents the output signal of the output terminal N4; Hy represents the Y-axis component of the external magnetic field.

[0076] In one embodiment, Figures 14 to 16 As shown, in the magnetic tunnel junction 140 located in the second magnetic field sensitive area 130 for detecting the magnetic field in the Z-axis direction, along the positive direction of the Y-axis, the magnetic tunnel junctions 140 having a pinning direction along the inclined surface of the inclined structure in the positive upward direction are partially connected in series to form a magnetoresistive unit R35 and partially connected in series to form a magnetoresistive unit R37, and the magnetic tunnel junctions 140 having a pinning direction along the inclined surface of the inclined structure in the positive downward direction are partially connected in series to form a magnetoresistive unit R36 and partially connected in series to form a magnetoresistive unit R38. The magnetoresistive unit R35 and the magnetoresistive unit R38 have the initial magnetization direction of the free layer in the negative direction of the X-axis direction, and the magnetoresistive unit R36 and the magnetoresistive unit R37 have the initial magnetization direction of the free layer in the positive direction of the X-axis direction.

[0077] One end of the magnetoresistance unit R35 is connected to the output terminal P5, and the other end of the magnetoresistance unit R35 is connected to the power supply terminal VCC5. One end of the magnetoresistance unit R38 is connected to the output terminal N5, and the other end of the magnetoresistance unit R38 is connected to the power supply terminal VCC5. One end of the magnetoresistance unit R36 is connected to the output terminal P5, and the other end of the magnetoresistance unit R36 is connected to the ground terminal GND. One end of the magnetoresistance unit R37 is connected to the output terminal N5, and the other end of the magnetoresistance unit R37 is connected to the ground terminal GND.

[0078] Specifically, Fig.14 As shown, taking the example that the inclined structure is arranged in the groove of the substrate 110, along the positive direction of the Y axis, the magnetic tunnel junction 140 used to form the magnetoresistive unit R36 (magnetoresistive unit R38) is arranged on the downslope of the groove, and the magnetic tunnel junction 140 used to form the magnetoresistive unit R35 (magnetoresistive unit R37) is arranged on the upslope of the groove, and the downslope and upslope of the groove have the same slope. The magnetic tunnel junctions 140 used to form the magnetoresistive unit R36 (magnetoresistive unit R38) and the magnetoresistive unit R35 (magnetoresistive unit R37) are annealed along the positive direction of the Y axis, so that the pinning direction generated by the magnetoresistive unit R36 (magnetoresistive unit R38) includes the positive direction component of the Y axis and the negative direction component of the Z axis, and the pinning direction generated by the magnetoresistive unit R35 (magnetoresistive unit R37) includes the positive direction component of the Y axis and the positive direction component of the Z axis.

[0079] Fig.15 The hollow arrow indicates the component of the pinning direction of the magnetic tunnel junction 140 in the Y-axis, and the solid arrow indicates the initial magnetization direction of the free layer of the magnetic tunnel junction 140. The pinning directions of the magnetoresistive unit R35, the magnetoresistive unit R36, the magnetoresistive unit R37, and the magnetoresistive unit R38 all have components along the positive direction of the Y-axis. In this way, the induction output of the Z-axis bridge for the Y-axis magnetic field is zero.

[0080] Furthermore, the pinning directions of the magnetoresistance units R36 and R38 include the negative direction component of the Z axis, and the pinning directions of the magnetoresistance units R35 and R37 include the positive direction component of the Z axis, so that the Z-axis bridge has an inductive output for the Z-axis magnetic field.

[0081] like Fig.16 As shown, when the sensor is working, the coil current direction of the area where the magnetoresistance unit R35 and the magnetoresistance unit R38 are located is along the positive direction of the Y axis, generating a setting magnetic field along the negative direction of the X axis, and the coil current direction of the area where the magnetoresistance unit R36 and the magnetoresistance unit R37 are located is along the negative direction of the Y axis, generating a setting magnetic field along the positive direction of the X axis. Therefore, the magnetoresistance unit R35 and the magnetoresistance unit R38 have the same initial magnetization direction of the free layer, both of which are in the negative direction of the X axis, and the magnetoresistance unit R36 and the magnetoresistance unit R37 have the same initial magnetization direction of the free layer, both of which are in the positive direction of the X axis.

[0082] When the sensor is working, when the external magnetic field has a component along the Z axis, the magnetization direction of the free layer of the magnetic tunnel junction 140 rotates at different angles depending on the magnitude of the magnetic field component, causing the resistance of the magnetoresistive unit R35 / magnetoresistive unit R37 to increase or decrease, and the resistance of the magnetoresistive unit R36 / magnetoresistive unit R38 to change, which is opposite to the resistance change of the magnetoresistive unit R35 / magnetoresistive unit R37. The differential signal S5 of the Z-axis bridge has an approximately linear change relationship with the Z-axis component of the external magnetic field, as shown in the following formula:

[0083]

[0084] Among them, MR and H k represents the intrinsic properties of the magnetic tunnel junction 140, which are magnetoresistivity and anisotropy field; V P5 Represents the output signal of output terminal P5, V N5 represents the output signal of the output terminal N5; Hz represents the Z-axis component of the external magnetic field, and θ represents the inclination angle of the inclined surface of the inclined structure relative to the plane of the substrate 110.

[0085] From the above, it can be seen that the components of the pinning direction of the magnetoresistive unit in the Z-axis bridge in the Y-axis direction are in the same direction, so the changes in resistance caused by the Y-axis magnetic field are consistent, resulting in the constructed bridge having no signal output in the Y-axis direction, while the components of the pinning direction of the magnetoresistive unit in the Z-axis direction are both positive and negative. Therefore, the Z-axis magnetic field component can be analyzed based on the differential signal S5.

[0086] In one embodiment, a method for preparing a TMR magnetic sensor is also provided, comprising:

[0087] Making an inclined structure on the substrate, wherein an inclined surface of the inclined structure is inclined between a second direction and a third direction;

[0088] A magnetic tunnel junction is formed on a substrate; the substrate is provided with a first magnetic field sensitive area and a second magnetic field sensitive area, both of which are composed of magnetic tunnel junctions connected in series or in parallel or in combination of series and parallel; the magnetic tunnel junction located in the first magnetic field sensitive area is arranged in the plane of the substrate and has a pinning direction along a first direction; the magnetic tunnel junction located in the second magnetic field sensitive area is at least partially arranged on an inclined surface of an inclined structure, and the magnetic tunnel junction arranged on the inclined surface of the inclined structure has a pinning direction along the inclined surface of the inclined structure; the first direction, the second direction and the third direction are perpendicular to each other, and the third direction is also perpendicular to the plane of the substrate.

[0089] In one embodiment, manufacturing an inclined structure on a substrate includes: providing a substrate; forming a first passivation layer on a surface of the substrate, wherein the substrate and the first passivation layer constitute the substrate; and arranging the inclined structure on the first passivation layer.

[0090] In one embodiment, forming a magnetic tunnel junction on a substrate includes: forming a TMR magnetic multilayer film on a plane of the substrate and on an inclined surface of an inclined structure; applying a release adhesive on the substrate and etching the TMR magnetic multilayer film to form a first metal layer and a magnetic tunnel junction; and performing metal coating and etching on the substrate to form a second metal layer connecting each magnetic tunnel junction.

[0091] In one embodiment, applying a stripping glue on a substrate and etching the TMR magnetic multilayer film to form a first metal layer and a magnetic tunnel junction includes: applying a stripping glue on the substrate for the first time, and etching the TMR magnetic multilayer film located on the plane of the substrate / the inclined surface of the inclined structure, to form the first metal layer and the magnetic tunnel junction located on the plane of the substrate / the inclined surface of the inclined structure; applying a stripping glue on the substrate for the second time, and etching the TMR magnetic multilayer film located on the inclined surface of the inclined structure / the plane of the substrate, to form the first metal layer and the magnetic tunnel junction located on the inclined surface of the inclined structure / the plane of the substrate.

[0092] It should be noted that the specific type of the inclined structure, as well as the arrangement and connection relationship of the magnetic tunnel junctions in the first magnetic field sensitive region and the second magnetic field sensitive region, have been explained in detail in the above-mentioned TMR magnetic sensor and will not be repeated here.

[0093] Specifically, the preparation process of the TMR magnetic sensor is as follows:

[0094] like Fig.17 As shown, first, a substrate 112 is provided, and the substrate 112 includes a CMOS wafer layer 1122 and a CMOS signal layer 1124 covering the CMOS wafer layer 1122. An integrated circuit composed of a plurality of MOS tubes is integrated in the CMOS wafer layer 1122, which can process the analog signals generated by the first magnetic field sensitive area and the second magnetic field sensitive area inducing the external magnetic field to obtain digital signals, and the CMOS signal layer 1124 can realize functions such as receiving analog signals and outputting digital signals, and the CMOS signal layer 1124 can be in the form of a metal layer, an integrated circuit layer, etc. Furthermore, the substrate 112 may also include a protective layer 1126 arranged on the CMOS signal layer 1124, which is used to protect the CMOS signal layer 1124. The material of the protective layer 1126 can specifically be silicon oxide (SiO2) or aluminum oxide (AlO x )wait.

[0095] like Fig.18 As shown, a first passivation layer 114 is formed on the surface of the substrate 112, and the substrate 112 and the first passivation layer 114 constitute the base plate 110. The first passivation layer 114 can be a silicon dioxide layer with a thickness of 3um to 5um. The first passivation layer 114 can be formed on the substrate 112 by coating, physical vapor deposition (PVD), chemical vapor deposition (CVD), etc. Fig.19As shown, the first passivation layer 114 is etched to form a groove, and the etching stops at the CMOS signal layer 1124. Fig. 20 As shown, a thin film is re-deposited on the substrate 110 to cover the CMOS signal layer 1124 exposed in the groove. The material of the thin film can be one or both of silicon oxide and silicon nitride.

[0096] like Fig.21 As shown, a TMR magnetic multilayer film 140a is deposited on the substrate 110. The TMR magnetic multilayer film 140a covers the plane and groove parts of the substrate 110. The TMR magnetic multilayer film 140a is a multilayer structure, specifically including the structure of the subsequent magnetic tunnel junction and the first metal layer. Fig. 22 As shown, the TMR magnetic multilayer film 140a is etched to the bottom metal wire, and a portion is reserved for the subsequent production of the first metal layer and the magnetic tunnel junction 140. In addition, the TMR magnetic multilayer film 140a on at least one groove is etched away to be used as a connection groove later. Fig.23 As shown, a connection hole 140 b is etched along the thickness direction at the bottom of the connection groove of the substrate 110 to expose the CMOS signal layer 1124 for subsequently connecting the second metal layer to the CMOS signal layer 1124 .

[0097] like Fig.24 As shown, a stripping glue 160 is applied to the substrate 110 and photolithography is performed, and the portion of the stripping glue 160 covering the connection hole 140b is retained, and the portion of the stripping glue 160 used for making a magnetic tunnel junction and supporting the second metal layer is retained on the TMR magnetic multilayer film 140a. Fig.25 As shown, the TMR magnetic multilayer film 140a is pattern-etched, and the portion of the TMR magnetic multilayer film 140a not covered with the stripping glue 160 is etched to form a first metal layer 170 and a magnetic tunnel junction 140. The first metal layer 170 is used to connect each magnetic tunnel junction 140. Fig.26 As shown, a portion of the second passivation layer 180 is deposited on the substrate 110 and the stripping glue 160 is removed, and the deposited portion of the second passivation layer 180 exposes the magnetic tunnel junction 140, the connection hole 140b, and the portion of the TMR magnetic multilayer film 140a used to support the second metal layer. The material of the second passivation layer 180 can be aluminum oxide or silicon oxide.

[0098] like Fig. 27 As shown, metal plating and etching are performed on the substrate 110 to form a second metal layer 190. The second metal layer 190 connects each magnetic tunnel junction 140 and extends to the substrate 110 through the connection hole 140b, electrically connecting the magnetic tunnel junction 140 and the substrate 110, so as to receive the output signal of the bridge formed by the magnetic tunnel junction 140. Fig.28As shown, another portion of the second passivation layer 180 is deposited on the second metal layer 190 to cover the second metal layer 190, thereby obtaining a complete second passivation layer 180. Fig.29 and Fig.30 As shown, the second passivation layer 180 is etched to obtain a top-layer connection hole 180a exposing the second metal layer 190, and then metal deposition and etching are performed to obtain a top-layer metal layer 200. A portion of the top-layer metal layer 200 is used to form the coil 150, and a portion is used to connect to the second metal layer 190 through the top-layer connection hole 180a. Finally, as shown in FIG. Fig.31 As shown, a third passivation layer 210 is deposited on the top metal layer 200 and a conductive solder joint opening 210a is formed. While protecting the top metal layer 200, the portion of the top metal layer 200 used to connect the second metal layer 190 can be electrically connected to an external device through the conductive solder joint opening 210a. The third passivation layer 210 can also be aluminum oxide or silicon oxide.

[0099] It should be noted that the preparation process of the above-mentioned TMR magnetic sensor adopts a method of applying a stripping glue once and then simultaneously pattern-etching the TMR magnetic multilayer film 140a located on the plane of the substrate 110 and the inclined surface of the inclined structure, so as to form the magnetic tunnel junction 140 on the plane of the substrate 110 and the inclined surface of the inclined structure. In other embodiments, the stripping glue may be applied twice, and the TMR magnetic multilayer film 140a located on the plane of the substrate 110 and the inclined surface of the inclined structure may be pattern-etched respectively to form the magnetic tunnel junction 140 at the corresponding position. For example, the stripping glue may be applied for the first time, and the TMR magnetic multilayer film 140a located on the plane of the substrate 110 / the inclined surface of the inclined structure may be pattern-etched to form the magnetic tunnel junction 140 located on the plane of the substrate 110 / the inclined surface of the inclined structure, and then the stripping glue may be applied for the second time, and the TMR magnetic multilayer film 140a located on the inclined surface of the inclined structure / the plane of the substrate 110 may be pattern-etched to form the magnetic tunnel junction 140 located on the inclined surface of the inclined structure / the plane of the substrate 110.

[0100] Specifically, after Figures 17 to 23 In the preparation process, after the connection hole 140b is etched along the thickness direction at the bottom of the connection groove of the substrate 110, as shown in FIG. Fig.32 As shown, firstly, the substrate 110 is coated with a release glue 160a for the first time, and the release glue 160a located on the plane of the substrate 110 is exposed and developed, so that the part of the TMR magnetic multilayer film 140a located on the plane of the substrate 110 for making the magnetic tunnel junction is covered, and the surrounding part is exposed. Fig.33 As shown, the exposed portion of the TMR magnetic multilayer film 140a located on the plane of the substrate 110 is ion-beam etched to form the first metal layer 170 and the magnetic tunnel junction 140 on the plane of the substrate 110, and the stripping glue 160a is retained. Fig.34 As shown, a second passivation layer 180 is deposited on a portion of the substrate 110 plane, and then the stripping glue 160a is removed. The deposited portion of the second passivation layer 180 in this step covers the planar first metal layer 170, exposing the planar magnetic tunnel junction 140. The second passivation layer 180 can be made of aluminum oxide or silicon oxide.

[0101] like Fig.35 As shown, the stripping glue 160b is coated on the substrate 110 for the second time, and the stripping glue 160b located in the groove of the substrate 110 is exposed and developed, so that the part of the TMR magnetic multilayer film 140a located in the groove of the substrate 110 for making the magnetic tunnel junction is covered, and the surrounding part is exposed. Fig.36 As shown, the exposed portion of the TMR magnetic multilayer film 140a located in the groove of the substrate 110 is ion-beam etched to form the first metal layer 170 and the magnetic tunnel junction 140 in the groove, and the stripping glue 160b is retained. The first metal layer 170 is used to connect each magnetic tunnel junction 140. Fig.37 As shown, the second passivation layer 180 is deposited on the substrate 110 at a portion of the groove, and then the stripping glue 160b is removed. The portion of the second passivation layer 180 deposited in this step is connected to the portion of the second passivation layer 180 on the plane of the substrate 110, and the portion of the second passivation layer 180 deposited in this step covers the first metal layer 170 of the groove, exposing the magnetic tunnel junction 140 of the groove. The second passivation layer 180 is not deposited on the connection groove provided with the connection hole 140b and the portion of the TMR magnetic multilayer film 140a used to support the second metal layer.

[0102] like Fig.38 As shown, metal plating and etching are performed on the substrate 110 to form a second metal layer 190. The second metal layer 190 connects each magnetic tunnel junction 140 and extends to the substrate 110 through the connection hole 140b, electrically connecting the magnetic tunnel junction 140 and the substrate 110, so as to receive the output signal of the bridge formed by the magnetic tunnel junction 140. Fig.39 As shown, the remaining portion of the second passivation layer 180 is deposited on the second metal layer 190 to cover the second metal layer 190, thereby obtaining a complete second passivation layer 180. Fig.40 and Fig.41 As shown, the second passivation layer 180 is etched to obtain a top-layer connection hole 180a exposing the second metal layer 190, and then metal deposition and etching are performed to obtain a top-layer metal layer 200. A portion of the top-layer metal layer 200 is used to form the coil 150, and a portion is used to connect to the second metal layer 190 through the top-layer connection hole 180a. Finally, as shown in FIG. Fig.42 and Fig.43As shown, a third passivation layer 210 is deposited on the top metal layer 200 and a conductive solder joint opening 210a is formed. While protecting the top metal layer 200, the portion of the top metal layer 200 used to connect the second metal layer 190 can be electrically connected to an external device through the conductive solder joint opening 210a. The third passivation layer 210 can also be aluminum oxide or silicon oxide.

[0103] Since the stripping adhesive has fluidity, the stripping adhesive easily forms a morphology with uneven thickness distribution on the inclined surface of the inclined structure, which makes it difficult to form an ideal stripping adhesive morphology on both the plane of the substrate 110 and the inclined surface of the inclined structure at one time, and thus it is impossible to obtain an ideal magnetic tunnel junction structure. By applying the stripping adhesive twice for pattern etching, that is, applying the stripping adhesive to the plane and the inclined surface respectively, so that the stripping adhesive forms a relatively good morphology on the plane and the inclined surface respectively, and then forming the magnetic tunnel junctions on the plane and the inclined surface respectively, the photolithography process of the magnetic tunnel junction structure on the plane and the inclined surface is separated, so that the desired structural pattern can be obtained, and the preparation reliability can be improved.

[0104] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0105] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A TMR magnetic sensor, characterized in that: include: a substrate, the substrate comprising an inclined structure, an inclined surface of the inclined structure being inclined between a second direction and a third direction; A first magnetic field sensitive region and a second magnetic field sensitive region are arranged on the substrate, wherein the first magnetic field sensitive region and the second magnetic field sensitive region are both composed of magnetic tunnel junctions connected in series or in parallel or in combination of series and parallel; the magnetic tunnel junction located in the first magnetic field sensitive region is arranged in the plane of the substrate and has a pinning direction along a first direction; the magnetic tunnel junction located in the second magnetic field sensitive region is at least partially arranged on the inclined surface of the inclined structure, and the magnetic tunnel junction arranged on the inclined surface of the inclined structure has a pinning direction along the inclined surface of the inclined structure; The first direction, the second direction and the third direction are perpendicular to each other, and the third direction is also perpendicular to the plane of the substrate.

2. The TMR magnetic sensor according to claim 1, characterized in that: The invention also includes a coil disposed on the substrate, and the coil is used to reset each magnetic tunnel junction in the first magnetic field sensitive area and the second magnetic field sensitive area when powered on.

3. The TMR magnetic sensor according to claim 2, characterized in that: The coil is a multi-turn planar coil; the portion of the coil that transmits current along the first direction is arranged corresponding to the first magnetic field sensitive area; the portion of the coil that transmits current along the second direction is arranged corresponding to the second magnetic field sensitive area; the number of the first magnetic field sensitive areas is two, and they are distributed along the second direction; the number of the second magnetic field sensitive areas is two, and they are distributed along the first direction, and are respectively located on both sides of the axis where the two first magnetic field sensitive areas are located.

4. The TMR magnetic sensor according to any one of claims 1 to 3, characterized in that: Among the magnetic tunnel junctions located in the first magnetic field sensitive region, a portion of the magnetic tunnel junctions having a pinning direction along the positive direction of the first direction are connected in series to form a magnetoresistance unit R11, and another portion are connected in series to form a magnetoresistance unit R13; a portion of the magnetic tunnel junctions having a pinning direction along the negative direction of the first direction are connected in series to form a magnetoresistance unit R12, and another portion are connected in series to form a magnetoresistance unit R14; the magnetoresistance units R11 and R14 have initial magnetization directions of the free layers along the positive direction of the second direction, and the magnetoresistance units R12 and R13 have initial magnetization directions of the free layers along the negative direction of the second direction; One end of the magnetoresistance unit R11 is connected to the output terminal P1, and the other end of the magnetoresistance unit R11 is connected to the power supply terminal VCC1; one end of the magnetoresistance unit R14 is connected to the output terminal N1, and the other end of the magnetoresistance unit R14 is connected to the power supply terminal VCC1; one end of the magnetoresistance unit R12 is connected to the output terminal P1, and the other end of the magnetoresistance unit R12 is connected to the ground terminal; one end of the magnetoresistance unit R13 is connected to the output terminal N1, and the other end of the magnetoresistance unit R13 is connected to the ground terminal.

5. The TMR magnetic sensor according to any one of claims 1 to 3, characterized in that: All magnetic tunnel junctions in the second magnetic field sensitive region are arranged on the inclined surface of the inclined structure.

6. The TMR magnetic sensor according to claim 5, characterized in that: The magnetic tunnel junction located in the second magnetic field sensitive area has a pinning direction along the inclined surface of the inclined structure, wherein the magnetic tunnel junctions having the pinning direction along the inclined surface of the inclined structure in a positive upward direction are partially connected in series to form a magnetoresistive unit R21 and partially connected in series to form a magnetoresistive unit R23, the magnetic tunnel junctions having the pinning direction along the inclined surface of the inclined structure in a negative downward direction are partially connected in series to form a magnetoresistive unit R22 and partially connected in series to form a magnetoresistive unit R24, the magnetic tunnel junctions having the pinning direction along the inclined surface of the inclined structure in a positive downward direction are partially connected in series to form a magnetoresistive unit R31 and partially connected in series to form a magnetoresistive unit R33, and the magnetic tunnel junctions having the pinning direction along the inclined surface of the inclined structure in a negative upward direction are partially connected in series to form a magnetoresistive unit R32 and partially connected in series to form a magnetoresistive unit R34; The magnetoresistance units R22, R23, R32 and R33 have initial magnetization directions of the free layers in the positive direction of the first direction, and the magnetoresistance units R21, R24, R31 and R34 have initial magnetization directions of the free layers in the negative direction of the first direction; One end of the magnetic resistance unit R21 is connected to the output terminal P2, and the other end of the magnetic resistance unit R21 is connected to the power supply terminal VCC2; one end of the magnetic resistance unit R24 is connected to the output terminal N2, and the other end of the magnetic resistance unit R24 is connected to the power supply terminal VCC2; one end of the magnetic resistance unit R22 is connected to the output terminal P2, and the other end of the magnetic resistance unit R22 is connected to the ground terminal; one end of the magnetic resistance unit R23 is connected to the output terminal N2, and the other end of the magnetic resistance unit R23 is connected to the ground terminal; One end of the magnetoresistance unit R31 is connected to the output terminal P3, the other end of the magnetoresistance unit R31 is connected to the power supply terminal VCC3, one end of the magnetoresistance unit R34 is connected to the output terminal N3, the other end of the magnetoresistance unit R34 is connected to the power supply terminal VCC3; one end of the magnetoresistance unit R32 is connected to the output terminal P3, the other end of the magnetoresistance unit R32 is connected to the ground terminal, one end of the magnetoresistance unit R33 is connected to the output terminal N3, the other end of the magnetoresistance unit R33 is connected to the ground terminal.

7. The TMR magnetic sensor according to any one of claims 1 to 3, characterized in that: The magnetic tunnel junction in the second magnetic field sensitive area for detecting the second direction magnetic field is arranged on the plane of the substrate; the magnetic tunnel junction in the second magnetic field sensitive area for detecting the third direction magnetic field is arranged on the inclined surface of the inclined structure.

8. The TMR magnetic sensor according to claim 7, characterized in that: In the magnetic tunnel junction located in the second magnetic field sensitive area for detecting the magnetic field in the second direction, a part of the magnetic tunnel junction having a pinning direction along the positive direction of the second direction is connected in series to form a magnetoresistance unit R25, and another part is connected in series to form a magnetoresistance unit R27; a part of the magnetic tunnel junction having a pinning direction along the negative direction of the second direction is connected in series to form a magnetoresistance unit R26, and another part is connected in series to form a magnetoresistance unit R28; the magnetoresistance unit R25 and the magnetoresistance unit R28 have a free layer initial magnetization direction along the positive direction of the first direction, and the magnetoresistance unit R26 and the magnetoresistance unit R27 have a free layer initial magnetization direction along the negative direction of the first direction; One end of the magnetoresistance unit R25 is connected to the output terminal P4, and the other end of the magnetoresistance unit R25 is connected to the power supply terminal VCC4; one end of the magnetoresistance unit R28 is connected to the output terminal N4, and the other end of the magnetoresistance unit R28 is connected to the power supply terminal VCC4; one end of the magnetoresistance unit R26 is connected to the output terminal P4, and the other end of the magnetoresistance unit R26 is connected to the ground terminal; one end of the magnetoresistance unit R27 is connected to the output terminal N4, and the other end of the magnetoresistance unit R27 is connected to the ground terminal.

9. The TMR magnetic sensor according to claim 7, characterized in that: In the magnetic tunnel junction located in the second magnetic field sensitive area for detecting the magnetic field in the third direction, a magnetic tunnel junction having a pinning direction along the inclined surface of the inclined structure in a positive upward direction is partially connected in series to form a magnetoresistance unit R35 and a magnetic tunnel junction having a pinning direction along the inclined surface of the inclined structure in a positive downward direction is partially connected in series to form a magnetoresistance unit R36 and a magnetic tunnel junction having a pinning direction along the inclined surface of the inclined structure in a positive downward direction is partially connected in series to form a magnetoresistance unit R38; the magnetoresistance unit R35 and the magnetoresistance unit R38 have an initial magnetization direction of the free layer in the negative direction of the first direction, and the magnetoresistance unit R36 and the magnetoresistance unit R37 have an initial magnetization direction of the free layer in the positive direction of the first direction; One end of the magnetic resistance unit R35 is connected to the output terminal P5, and the other end of the magnetic resistance unit R35 is connected to the power supply terminal VCC5; one end of the magnetic resistance unit R38 is connected to the output terminal N5, and the other end of the magnetic resistance unit R38 is connected to the power supply terminal VCC5; One end of the magnetoresistance unit R36 is connected to the output terminal P5, and the other end of the magnetoresistance unit R36 is connected to the ground terminal. One end of the magnetoresistance unit R37 is connected to the output terminal N5, and the other end of the magnetoresistance unit R37 is connected to the ground terminal.

10. A method for preparing a TMR magnetic sensor, characterized in that: include: Making an inclined structure on the substrate, wherein an inclined surface of the inclined structure is inclined between a second direction and a third direction; A magnetic tunnel junction is formed on the substrate; the substrate is provided with a first magnetic field sensitive area and a second magnetic field sensitive area, and the first magnetic field sensitive area and the second magnetic field sensitive area are both composed of the magnetic tunnel junctions connected in series or in parallel or in a combination of series and parallel; the magnetic tunnel junction located in the first magnetic field sensitive area is arranged in the plane of the substrate and has a pinning direction along a first direction; the magnetic tunnel junction located in the second magnetic field sensitive area is at least partially arranged on the inclined surface of the inclined structure, and the magnetic tunnel junction arranged on the inclined surface of the inclined structure has a pinning direction along the inclined surface of the inclined structure; The first direction, the second direction and the third direction are perpendicular to each other, and the third direction is also perpendicular to the plane of the substrate.

11. The method for preparing a TMR magnetic sensor according to claim 10, characterized in that: The manufacturing of the inclined structure on the substrate comprises: providing a substrate; forming a first passivation layer on the surface of the substrate, wherein the substrate and the first passivation layer constitute the base plate; The inclined structure is disposed on the first passivation layer.

12. The method for preparing a TMR magnetic sensor according to claim 10, characterized in that: The forming of a magnetic tunnel junction on the substrate comprises: forming a TMR magnetic multilayer film on the plane of the substrate and the inclined surface of the inclined structure; Applying a release adhesive on the substrate and etching the TMR magnetic multilayer film to form a first metal layer and the magnetic tunnel junction; Metal coating and etching are performed on the substrate to form a second metal layer connecting the magnetic tunnel junctions.

13. The method for preparing a TMR magnetic sensor according to claim 12, characterized in that: The step of applying a release glue on the substrate and etching the TMR magnetic multilayer film to form a first metal layer and a magnetic tunnel junction comprises: Applying a stripping glue on the substrate for the first time, and etching the TMR magnetic multilayer film located on the inclined surface of the plane / inclined structure of the substrate to form the first metal layer and the magnetic tunnel junction located on the inclined surface of the plane / inclined structure of the substrate; The substrate is coated with a stripping glue for the second time, and the TMR magnetic multilayer film located on the inclined surface of the inclined structure / the plane of the substrate is etched to form the first metal layer and the magnetic tunnel junction located on the inclined surface of the inclined structure / the plane of the substrate.

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