Method for manufacturing magnetic sensor

Abstract

The invention relates to a manufacturing method of a magnetic sensor. The magnetic sensor includes at least one MR element and at least one magnetic field generator. The at least one MR element includes a magnetization-fixed layer and a free layer. The at least one magnetic field generating body includes a ferromagnetic part and an antiferromagnetic part that is exchange-coupled to the ferromagnetic part. A method for manufacturing a magnetic sensor includes a step of forming at least one MR element, and a step of forming at least one magnetic field generator. The step of forming the at least one magnetic field generating body includes: a step of forming at least one initial magnetic field generating body including an initial ferromagnetic part and an antiferromagnetic part that later become a ferromagnetic part; and a step for fixing the direction of magnetization of the initial ferromagnetic part using the laser and the external magnetic field so that the initial ferromagnetic part becomes a ferromagnetic part.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a magnetic sensor configured to apply a bias magnetic field to a magnetoresistive element. Background Art

[0002] In recent years, magnetic sensors are used in various applications. Sometimes, a magnetic sensor is used in some applications, and the magnetic sensor uses a spin valve type magnetoresistive element provided on a substrate. The spin valve type magnetoresistive element has a magnetization fixed layer in which the direction of magnetization is fixed, a free layer in which the direction of magnetization can vary according to the direction of an object magnetic field, and a spacer layer disposed between the magnetization fixed layer and the free layer.

[0003] There is a case where a certain magnetic sensor includes a unit that applies a bias magnetic field to the magnetoresistive element.

[0004] Japanese Unexamined Patent Application Publication No. 2015-125020 and Chinese Patent Application Publication No. 105988092A disclose a magnetic sensor that includes a magnetoresistive element and two magnetic field generators configured to sandwich the magnetoresistive element.

[0005] However, in a magnetic sensor, there is a requirement that when there is no object magnetic field, the direction of magnetization of the free layer of one of two adjacent magnetoresistive elements is different from the direction of magnetization of the free layer of the other. Summary of the Invention

[0006] One object of the present invention is to provide a method for manufacturing a magnetic sensor capable of making the direction of magnetization of the free layer of at least one magnetoresistive element different.

[0007] The magnetic sensor manufactured by the manufacturing method according to one embodiment of the present invention includes: at least one magnetoresistive element including a magnetization-fixed layer having magnetization with a component in a first direction, that is, magnetization with a fixed direction, and a free layer whose magnetization direction can vary according to a magnetic field to be detected, that is, an object magnetic field; and at least one magnetic field generator including a ferromagnetic portion and an antiferromagnetic portion, and configured to generate a magnetic field applied to the at least one magnetoresistive element, the ferromagnetic portion including a ferromagnetic material and having magnetization with a component in a second direction different from the first direction, that is, magnetization with a fixed direction, and the antiferromagnetic portion including an antiferromagnetic material and being exchange-coupled with the ferromagnetic portion. The manufacturing method of the magnetic sensor according to one embodiment of the present invention includes: a step of forming at least one magnetoresistive element, and a step of forming at least one magnetic field generator. The step of forming at least one magnetic field generator includes: a step of forming at least one initial magnetic field generator including an initial ferromagnetic portion that will later become the ferromagnetic portion and the antiferromagnetic portion; and a step of fixing the magnetization direction of the initial ferromagnetic portion by using a laser and a first external magnetic field including a component in a first magnetic field direction so that the initial ferromagnetic portion becomes the ferromagnetic portion.

[0008] In the manufacturing method of the magnetic sensor according to one embodiment of the present invention, the magnetization direction of the initial ferromagnetic portion is fixed by using a laser and a first external magnetic field including a component in a first magnetic field direction so that the initial ferromagnetic portion becomes the ferromagnetic portion. Thus, according to the present invention, the magnetization directions of the free layers of the at least one magnetoresistive element can be made different.

[0009] Other objects, features, and advantages of the present invention will become fully clear from the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is a perspective view of a magnetic sensor device including the magnetic sensor according to the first embodiment of the present invention.

[0011] Figure 2 is a functional block diagram showing the structure of the magnetic sensor device in the first embodiment of the present invention.

[0012] Figure 3 is a circuit diagram showing the circuit structure of the magnetic sensor according to the first embodiment of the present invention.

[0013] Figure 4 is a perspective view of a part of the first detection circuit in the first embodiment of the present invention.

[0014] Figure 5 is a top view of a part of the first detection circuit in the first embodiment of the present invention.

[0015] Figure 6It is a top view showing a part of the second detection circuit in the first embodiment of the present invention.

[0016] Figure 7 It is a top view showing the main part of the magnetic sensor in the first embodiment of the present invention.

[0017] Figure 8 It is showing Figure 7 A cross-sectional view of a part of the cross-section at the position indicated by the line 8-8 in

[0018] Figure 9 It is a top view showing a process in the manufacturing method of the magnetic sensor in the first embodiment of the present invention.

[0019] Figure 10 It is showing the subsequent Figure 9 Process top view.

[0020] Figure 11 It is showing the subsequent Figure 10 Process top view.

[0021] Figure 12 It is showing the subsequent Figure 11 Process top view.

[0022] Figure 13 It is showing the subsequent Figure 12 Process top view.

[0023] Figure 14A It is a top view showing a second example of the configuration of the resistance portion and the magnetization direction of the ferromagnetic portion of the magnetic field generating body in the first embodiment of the present invention.

[0024] Figure 14B It is a top view showing a third example of the configuration of the resistance portion and the magnetization direction of the ferromagnetic portion of the magnetic field generating body in the first embodiment of the present invention.

[0025] Figure 14C It is a top view showing a fourth example of the configuration of the resistance portion and the magnetization direction of the ferromagnetic portion of the magnetic field generating body in the first embodiment of the present invention.

[0026] Figure 15A It is a top view showing a fifth example of the configuration of the resistance portion and the magnetization direction of the ferromagnetic portion of the magnetic field generating body in the first embodiment of the present invention.

[0027] Figure 15B It is a top view showing a sixth example of the configuration of the resistance portion and the magnetization direction of the ferromagnetic portion of the magnetic field generating body in the first embodiment of the present invention.

[0028] Figure 15CIt is a top view showing a seventh example of the arrangement of the resistance portion and the direction of magnetization of the ferromagnetic portion of the magnetic field generating body in the first embodiment of the present invention.

[0029] Figure 16A It is a top view showing an eighth example of the arrangement of the resistance portion and the direction of magnetization of the ferromagnetic portion of the magnetic field generating body in the first embodiment of the present invention.

[0030] Figure 16B It is a top view showing a ninth example of the arrangement of the resistance portion and the direction of magnetization of the ferromagnetic portion of the magnetic field generating body in the first embodiment of the present invention.

[0031] Figure 16C It is a top view showing a tenth example of the arrangement of the resistance portion and the direction of magnetization of the ferromagnetic portion of the magnetic field generating body in the first embodiment of the present invention.

[0032] Figure 17A It is a top view showing an eleventh example of the arrangement of the resistance portion and the direction of magnetization of the ferromagnetic portion of the magnetic field generating body in the first embodiment of the present invention.

[0033] Figure 17B It is a top view showing a twelfth example of the arrangement of the resistance portion and the direction of magnetization of the ferromagnetic portion of the magnetic field generating body in the first embodiment of the present invention.

[0034] Figure 18 It is a cross-sectional view of the main part of the first modification of the magnetic sensor according to the first embodiment of the present invention.

[0035] Figure 19 It is a cross-sectional view of the main part of the second modification of the magnetic sensor according to the first embodiment of the present invention.

[0036] Figure 20 It is a cross-sectional view of the main part of the third modification of the magnetic sensor according to the first embodiment of the present invention.

[0037] Figure 21 It is a cross-sectional view of the main part of the fourth modification of the magnetic sensor according to the first embodiment of the present invention.

[0038] Figure 22 It is a cross-sectional view of the main part of the fifth modification of the magnetic sensor according to the first embodiment of the present invention.

[0039] Figure 23 It is a top view of the main part of the magnetic sensor according to the second embodiment of the present invention.

[0040] Figure 24 It is showing Figure 23 A cross-sectional view of a part of the cross-section at the position indicated by line 24 - 24 in

[0041] Figure 25 It is a top view showing the main part of the magnetic sensor according to the third embodiment of the present invention.

[0042] Figure 26 It shows Figure 25 A cross-sectional view of a part of the cross-section at the position indicated by the line 26-26 in

[0043] Figure 27 It is a top view showing one process in the manufacturing method of the magnetic sensor according to the third embodiment of the present invention.

[0044] Figure 28 It shows the subsequent Figure 27 Process top view.

[0045] Figure 29 It shows the subsequent Figure 28 Process top view.

[0046] Figure 30 It shows the subsequent Figure 29 Process top view.

[0047] Figure 31 It is a cross-sectional view showing the main part of a modified example of the magnetic sensor according to the third embodiment of the present invention.

[0048] Figure 32 It is a top view showing the main part of the magnetic sensor according to the fourth embodiment of the present invention.

[0049] Figure 33 It shows Figure 32 A cross-sectional view of a part of the cross-section at the position indicated by the line 33-33 in

[0050] Figure 34 It is a top view showing the main part of the first modified example of the magnetic sensor according to the fourth embodiment of the present invention.

[0051] Figure 35 It is a cross-sectional view showing the main part of the second modified example of the magnetic sensor according to the fourth embodiment of the present invention.

[0052] Figure 36 It is a cross-sectional view showing the main part of the third modified example of the magnetic sensor according to the fourth embodiment of the present invention.

[0053] Figure 37 It is a perspective view showing a magnetic sensor system including the magnetic sensor according to the fifth embodiment of the present invention.

[0054] Figure 38 It is a circuit diagram showing the circuit structure of the magnetic sensor according to the fifth embodiment of the present invention.

[0055] Figure 39 It is a perspective view of a part of the magnetic sensor according to the fifth embodiment of the present invention.

[0056] Figure 40 It is a top view of a part of the magnetic sensor according to the fifth embodiment of the present invention.

[0057] Figure 41 It is a side view of a part of the magnetic sensor according to the fifth embodiment of the present invention.

[0058] Figure 42 It is a top view of the main part of the magnetic sensor according to the fifth embodiment of the present invention.

[0059] Figure 43 It represents Figure 42 A cross-sectional view of a part of the cross-section at the position indicated by the line 43-43 in.

[0060] Figure 44 It represents Figure 42 A cross-sectional view of a part of the cross-section at the position indicated by the line 44-44 in. Detailed Embodiments

[0061] [First Embodiment]

[0062] Hereinafter, with reference to the drawings, embodiments of the present invention will be described in detail. First, with reference to Figure 1 and Figure 2 , the structure of the magnetic sensor device including the magnetic sensor according to the first embodiment of the present invention will be described. Figure 1 It is a perspective view of the magnetic sensor device in the present embodiment. Figure 2 It is a functional block diagram showing the structure of the magnetic sensor device in the present embodiment.

[0063] The magnetic sensor device 100 in the present embodiment includes the magnetic sensor 1 and the processor 2 of the present embodiment. The magnetic sensor 1 is configured to detect the magnetic field of the detection object of the magnetic sensor 1, that is, the object magnetic field, and generate at least one detection signal. The magnetic sensor 1 may be a geomagnetic sensor for detecting geomagnetism, a magnetic sensor for an angle sensor or a magnetic encoder for detecting a rotational magnetic field, or a magnetic sensor for a current sensor for detecting the magnetic field generated by a detected current.

[0064] The processor 2 is configured to generate at least one detection value having a correspondence with the object magnetic field based on at least one detection signal. The processor 2 is constituted by, for example, an application specific integrated circuit (ASIC).

[0065] The magnetic sensor 1 and the processor 2 each have the form of a chip with a rectangular parallelepiped shape. The magnetic sensor 1 has an upper surface 1a and a lower surface 1b located on opposite sides, and four side surfaces connecting the upper surface 1a and the lower surface 1b. The processor 2 includes an upper surface 2a and a lower surface 2b located on opposite sides, and four side surfaces connecting the upper surface 2a and the lower surface 2b. The magnetic sensor 1 is mounted on the upper surface 2a of the processor 2 in a posture where the lower surface 1b of the magnetic sensor 1 faces the upper surface 2a of the processor 2. The magnetic sensor 1 is joined to the processor 2, for example, by an adhesive.

[0066] Here, as Figure 1 shown, the X direction, Y direction, and Z direction are defined. The X direction, Y direction, and Z direction are mutually orthogonal. In the present embodiment, the direction perpendicular to the upper surface 1a of the magnetic sensor 1, that is, the direction from the lower surface 1b of the magnetic sensor 1 toward the upper surface 1a, is set as the Z direction. In addition, the direction opposite to the X direction is set as the -X direction, the direction opposite to the Y direction is set as the -Y direction, and the direction opposite to the Z direction is set as the -Z direction.

[0067] Hereinafter, a position in front of the reference position in the Z direction is referred to as "above", and a position on the side opposite to "above" with respect to the reference position is referred to as "below". In addition, regarding the components of the magnetic sensor 1, the surface located at one end in the Z direction is referred to as the "upper surface", and the surface located at one end in the -Z direction is referred to as the "lower surface". In addition, an expression such as "when viewed from a specified direction (for example, the Z direction)" means observing an object from a position separated in a specified direction or a direction parallel to the specified direction.

[0068] The magnetic sensor 1 has a plurality of first pads (electrode pads) provided on the upper surface 1a. The processor 2 has a plurality of second pads (electrode pads) provided on the upper surface 2a. In the magnetic sensor 1, two corresponding pads among the plurality of first pads and the plurality of second pads are connected to each other by bonding wires.

[0069] The magnetic sensor 1 includes a first detection circuit 10 and a second detection circuit 20. The first and second detection circuits 10, 20 and the processor 2 are connected via the plurality of first pads, the plurality of second pads, and the plurality of bonding wires.

[0070] The first and second detection circuits 10, 20 each include a plurality of magnetic detection elements. In the present embodiment, in particular, the plurality of magnetic detection elements are a plurality of magnetoresistive effect elements. Hereinafter, the magnetoresistive effect element is referred to as an MR element.

[0071] The first detection circuit 10 detects the component of the magnetic field of the object in the direction parallel to the X direction, and generates at least one first detection signal having a corresponding relationship with this component. The second detection circuit 20 detects the component of the magnetic field of the object in the direction parallel to the Y direction, and generates at least one second detection signal having a corresponding relationship with this component.

[0072] Next, with reference to ​ the circuit structure of the magnetic sensor 1 will be described. ​ It is a circuit diagram showing the circuit structure of the magnetic sensor 1.

[0073] The first detection circuit 10 includes four resistor parts R11, R12, R13, R14, a power supply port V1, a ground port G1, and two output ports E11, E12. The resistor part R11 is disposed between the power supply port V1 and the output port E11. The resistor part R12 is disposed between the output port E11 and the ground port G1. The resistor part R13 is disposed between the output port E22 and the ground port G2. The resistor part R14 is disposed between the power supply port V1 and the output port E22. A voltage or current of a specified magnitude is applied to the power supply port V1. The ground port G1 is grounded.

[0074] The second detection circuit 20 includes four resistor parts R21, R22, R23, R24, a power supply port V2, a ground port G2, and two output ports E21, E22. The resistor part R21 is disposed between the power supply port V2 and the output port E21. The resistor part R22 is disposed between the output port E21 and the ground port G2. The resistor part R23 is disposed between the output port E22 and the ground port G2. The resistor part R24 is disposed between the power supply port V2 and the output port E22. A voltage or current of a specified magnitude is applied to the power supply port V2. The ground port G2 is grounded.

[0075] Next, with reference to ​ the structures of the first and second detection circuits 10 and 20 will be described respectively. ​ It is a perspective view showing a part of the first detection circuit 10. ​ It is a top view showing a part of the first detection circuit 10. ​ It is a top view showing a part of the second detection circuit 20.

[0076] The magnetic sensor 1 further includes a substrate 30. The magnetic sensor 1 is formed by forming a plurality of components other than the substrate 30 on the substrate 30. The first detection circuit 10 and the second detection circuit 20 are disposed on the substrate 30. The resistor parts R11 to R14 each include a plurality of MR elements 50A. The resistor parts R21 to R24 each include a plurality of MR elements 50B.

[0077] A plurality of MR elements 50A constituting the resistance part R11 are disposed between the power supply port V1 and the output port E11 in the circuit structure. A plurality of MR elements 50A constituting the resistance part R12 are disposed between the output port E11 and the ground port G1 in the circuit structure. A plurality of MR elements 50A constituting the resistance part R13 are disposed between the output port E12 and the ground port G1 in the circuit structure. A plurality of MR elements 50A constituting the resistance part R14 are disposed between the power supply port V1 and the output port E12 in the circuit structure.

[0078] A plurality of MR elements 50B constituting the resistance part R21 are disposed between the power supply port V2 and the output port E21 in the circuit structure. A plurality of MR elements 50B constituting the resistance part R22 are disposed between the output port E21 and the ground port G2 in the circuit structure. A plurality of MR elements 50B constituting the resistance part R23 are disposed between the output port E22 and the ground port G2 in the circuit structure. A plurality of MR elements 50B constituting the resistance part R24 are disposed between the power supply port V2 and the output port E22 in the circuit structure.

[0079] ​ Shows a first example of the arrangement of the resistance parts R11 to R14 in the substrate 30. In this example, the resistance part R12 is disposed in front of the resistance part R11 in the X direction. The resistance part R13 is disposed in front of the resistance part R12 in the Y direction. The resistance part R14 is disposed in front of the resistance part R11 in the Y direction.

[0080] ​ Shows a first example of the arrangement of the resistance parts R21 to R24 in the substrate 30. In this example, the resistance part R22 is disposed in front of the resistance part R21 in the Y direction. The resistance part R23 is disposed in front of the resistance part R22 in the -X direction. The resistance part R24 is disposed in front of the resistance part R21 in the -X direction.

[0081] Subsequent descriptions are made of other multiple examples of the arrangements of the resistance parts R11 to R14 and R21 to R24 in the substrate 30.

[0082] Each of the resistance parts R11 to R14 further includes a plurality of lower electrodes 61 and a plurality of upper electrodes 62. As ​ shown, each of the plurality of lower electrodes 61 electrically connects two adjacent MR elements 50A in a direction parallel to the X direction. Each of the plurality of upper electrodes 62 is disposed above the two lower electrodes 61 and electrically connects two adjacent MR elements 50A. Thus, a plurality of MR elements 50A arranged in a row in a direction parallel to the X direction are connected in series.

[0083] Each of the resistance portions R11 to R14 also includes a plurality of connection electrodes (not shown). In each of the resistance portions R11 to R14, the plurality of connection electrodes electrically connect the plurality of lower electrodes 61 or the plurality of upper electrodes 62 so that groups of the plurality of MR elements 50A arranged in a column are connected in series. With this structure, each of the resistance portions R11 to R14 includes the plurality of lower electrodes 61, the plurality of upper electrodes 62, and the plurality of MR elements 50A connected in series by the plurality of connection electrodes.

[0084] The above description of the connection relationship of the plurality of MR elements 50A basically also applies to the plurality of MR elements 50B of each of the resistance portions R21 to R24. If, in the above description of the connection relationship of the plurality of MR elements 50A, the plurality of MR elements 50A, the X direction, and the Y direction are respectively replaced with the plurality of MR elements 50B, the Y direction, and the X direction, it becomes the description of the connection relationship of the plurality of MR elements 50B.

[0085] The magnetic sensor 1 also includes a plurality of magnetic field generators 70A and a plurality of magnetic field generators 70B. The plurality of magnetic field generators 70A includes pairs of the plurality of magnetic field generators 70A each composed of two magnetic field generators 70A. The above two magnetic field generators 70A are arranged at a predetermined interval in a direction parallel to the Y direction so as to sandwich one MR element 50A. The two magnetic field generators 70A are configured to apply a bias magnetic field to one MR element 50A located therebetween. The bias magnetic field is a part of the magnetic field generated by the magnetic field generator 70A and includes, as a main component, a component in a direction parallel to the Y direction. At least the main component of the bias magnetic field is applied to the MR element 50A.

[0086] The plurality of magnetic field generators 70B includes pairs of the plurality of magnetic field generators 70B each composed of two magnetic field generators 70B. The above two magnetic field generators 70B are arranged at a predetermined interval in a direction parallel to the X direction so as to sandwich one MR element 50B. The two magnetic field generators 70B are configured to apply a bias magnetic field to one MR element 50B located therebetween. The bias magnetic field is a part of the magnetic field generated by the magnetic field generator 70B and includes, as a main component, a component in a direction parallel to the X direction. At least the main component of the bias magnetic field is applied to the MR element 50B.

[0087] As ​ shown, each of the plurality of magnetic field generators 70A may also be sandwiched between the lower electrode 61 and the upper electrode 62. Although not shown, each of the plurality of magnetic field generators 70B may also be sandwiched between the lower electrode 61 and the upper electrode 62.

[0088] In the present embodiment, each of the plurality of MR elements 50A and the plurality of MR elements 50B is a spin valve type MR element. The spin valve type MR element may also include a magnetization fixing layer in which the direction of magnetization is fixed, a free layer in which the direction of magnetization can vary according to the direction and intensity of the target magnetic field, and a spacer layer disposed between the magnetization fixing layer and the free layer. The spin valve type MR element may be a TMR (tunnel magnetoresistance effect) element or a GMR (giant magnetoresistance effect) element. In the TMR element, the spacer layer is a tunnel barrier layer. In the GMR element, the spacer layer is a non-magnetic conductive layer. In the spin valve type MR element, the resistance value varies according to the angle formed by the direction of magnetization of the free layer with respect to the direction of magnetization of the magnetization fixing layer. When this angle is 0°, the resistance value becomes the minimum, and when the angle is 180°, the resistance value becomes the maximum. In each MR element, the free layer has shape anisotropy in which the direction of the easy magnetization axis becomes orthogonal to the direction of magnetization of the magnetization fixing layer.

[0089] The bias magnetic field is used, for example, to make the MR element linearly respond to changes in the intensity of the target magnetic field. In addition, in a magnetic sensor using a spin valve type MR element, the bias magnetic field is also used to single-domainize the free layer and make the direction of magnetization of the free layer face a certain direction when there is no target magnetic field. However, in a magnetic sensor, there is a requirement that when there is no target magnetic field, the direction of magnetization of the free layer of one of the two adjacent MR elements is different from the direction of magnetization of the free layer of the other. Conventionally, for such a requirement, the application of a magnetic field generating body formed by laminating an antiferromagnetic layer and a ferromagnetic layer has not been considered.

[0090] Next, with reference to ​ 、 ​ and ​ the direction of magnetization of the magnetization fixing layer and the direction of the bias magnetic field will be described. In ​ , a plurality of solid arrows respectively depicted so as to overlap with the resistance portions R11 to R14, R21 to R24 represent the direction of magnetization of the magnetization fixing layer in each of the resistance portions R11 to R14, R21 to R24. In ​ , a plurality of arrows depicted so as to overlap with the plurality of MR elements 50A of each of the resistance portions R11 to R14 represent the direction of magnetization of the magnetization fixing layer in each of the resistance portions R11 to R14. In ​ , a plurality of arrows depicted so as to overlap with the plurality of MR elements 50B of each of the resistance portions R21 to R24 represent the direction of magnetization of the magnetization fixing layer in each of the resistance portions R21 to R24.

[0091] In ​ and ​In the example shown, the direction of the main component of the magnetization of the magnetization fixing layer in each of the resistance units R11 and R13 is the X direction. The direction of the main component of the magnetization of the magnetization fixing layer in each of the resistance units R12 and R14 is the -X direction. Each of the free layers in the resistance units R11 to R14 has shape anisotropy in which the direction of the easy magnetization axis is parallel to the Y direction.

[0092] In ​ and ​ In the example shown, the direction of the main component of the magnetization of the magnetization fixing layer in each of the resistance units R21 and R23 is the Y direction. The direction of the main component of the magnetization of the magnetization fixing layer in each of the resistance units R22 and R24 is the -Y direction. Each of the free layers in the resistance units R21 to R24 has shape anisotropy in which the direction of the easy magnetization axis is parallel to the X direction.

[0093] In ​ the arrows marked with symbols M11, M12, M13, and M14 respectively indicate the directions of the main components of the bias magnetic fields generated by the plurality of magnetic field generators 70A in the resistance units R11, R12, R13, and R14. In ​ the directions of the main components of the bias magnetic fields generated by the plurality of magnetic field generators 70A are indicated by a plurality of arrows drawn so as to overlap with the plurality of magnetic field generators 70A. The direction of the main component of the bias magnetic field in the resistance units R11 and R12 may also be the Y direction. The direction of the main component of the bias magnetic field in the resistance units R13 and R14 may also be the -Y direction.

[0094] In ​ the plurality of hollow arrows drawn so as to overlap with the resistance units R11 to R14 respectively indicate the directions of the magnetization of the free layers in the resistance units R11 to R14 when no object magnetic field is applied to the magnetic sensor 1. The direction of the main component of the magnetization of the free layers in the resistance units R11 and R12 may be the Y direction, or may be the same as the direction of the main component of the bias magnetic field in the resistance units R11 and R12. The direction of the main component of the magnetization of the free layers in the resistance units R13 and R14 may be the -Y direction, or may be the same as the direction of the main component of the bias magnetic field in the resistance units R13 and R14.

[0095] In ​ the arrows marked with symbols M21, M22, M23, and M24 respectively indicate the directions of the main components of the bias magnetic fields generated by the plurality of magnetic field generators 70B in the resistance units R21, R22, R23, and R24. In ​Among them, the directions of the main components of the bias magnetic fields generated by the plurality of magnetic field generating bodies 70B are indicated by a plurality of arrows drawn so as to overlap with the plurality of magnetic field generating bodies 70B. The direction of the main component of the bias magnetic field in the resistance units R21 and R22 may also be the -X direction. The direction of the main component of the bias magnetic field in the resistance units R23 and R24 may also be the X direction.

[0096] In ​ Among them, a plurality of hollow arrows drawn so as to overlap with the resistance units R21 to R24 respectively indicate the magnetization directions of the free layers in the resistance units R21 to R24 when no object magnetic field is applied to the magnetic sensor 1. The direction of the main component of the magnetization in the resistance units R21 and R22 may be the -X direction, or may be the same as the direction of the main component of the bias magnetic field in the resistance units R21 and R22. The direction of the main component of the magnetization in the resistance units R23 and R24 may be the X direction, or may be the same as the direction of the main component of the bias magnetic field in the resistance units R23 and R24.

[0097] In addition, the direction of magnetization may coincide with the direction of the main component of the magnetization described above, or may deviate slightly from the direction of the main component of the magnetization. Similarly, the direction of the bias magnetic field may coincide with the direction of the main component of the bias magnetic field described above, or may deviate slightly from the direction of the main component of the bias magnetic field. In the following description, the direction of magnetization is made to coincide with the direction of the main component of the magnetization, and the direction of the bias magnetic field is made to coincide with the direction of the main component of the bias magnetic field.

[0098] Next, with reference to ​ The operations of the first and second detection circuits 10 and 20 will be described. In the first detection circuit 10, the potential of the connection point of the resistance units R11 and R12, that is, the potential of the output port E11, and the potential of the connection point of the resistance units R13 and R14, that is, the potential of the output port E12, change according to the intensity of the component of the object magnetic field parallel to the X direction. The first detection circuit 10 may also generate a signal corresponding to the potential of the output port E11 and a signal corresponding to the potential of the output port E12 as first detection signals, respectively. Alternatively, the first detection circuit 10 may generate a signal corresponding to the potential difference between the output ports E11 and E12 as a first detection signal. In this case, the first detection circuit 10 may further include a differential amplifier (differential detector) that outputs a signal corresponding to the potential difference between the output ports E11 and E12 as a first detection signal.

[0099] In the second detection circuit 20, the potential at the connection point of the resistor sections R21 and R22, i.e., the potential of the output port E21, and the potential at the connection point of the resistor sections R23 and R24, i.e., the potential of the output port E22, vary according to the intensity of the component of the target magnetic field in the direction parallel to the Y direction. The second detection circuit 20 may also generate a signal corresponding to the potential of the output port E21 and a signal corresponding to the potential of the output port E22 as the second detection signals, respectively. Alternatively, the second detection circuit 20 may generate a signal corresponding to the potential difference between the output ports E21 and E22 as the second detection signal. In this case, the second detection circuit 20 may further include a differential amplifier (differential detector) that outputs a signal corresponding to the potential difference between the output ports E21 and E22 as the second detection signal.

[0100] Next, with reference to ​ and ​ the structures of the plurality of MR elements 50A, the plurality of MR elements 50B, the plurality of magnetic field generators 70A, and the plurality of magnetic field generators 70B will be described in detail. ​ is a top view showing the main part of the magnetic sensor 1. ​ is showing ​ a cross-sectional view of a part of the cross-section at the position indicated by the line 8-8 in

[0101] Here, as ​ and ​ shown, a first direction D1 and a second direction D2 that are orthogonal to each other and orthogonal to the Z direction are defined, respectively. In the first detection circuit 10, the first direction D1 is the direction parallel to the Y direction, and the second direction D2 is the direction parallel to the X direction. In the second detection circuit 20, the first direction D1 is the direction parallel to the X direction, and the second direction D2 is the direction parallel to the Y direction.

[0102] Hereinafter, any MR element among the plurality of MR elements 50A and the plurality of MR elements 50B is represented by the symbol 50, and any magnetic field generator among the plurality of magnetic field generators 70A and the plurality of magnetic field generators 70B is represented by the symbol 70. The magnetic sensor 1 includes at least one MR element 50. In the present embodiment, in particular, as the at least one MR element 50, the magnetic sensor 1 includes a plurality of MR elements 50.

[0103] Here, focusing on one MR element 50, the structures of the MR element 50 and the magnetic field generator 70 will be described. The MR element 50 includes a plurality of magnetic films. The stacking direction of the plurality of magnetic films is the direction parallel to the Z direction. The plurality of magnetic films include a magnetization fixed layer 52 and a free layer 54. Each of the plurality of MR elements 50 further includes a gap layer 53, a buffer layer 51, and a cover layer 55. As ​As shown, a buffer layer 51, a magnetization-fixed layer 52, a spacer layer 53, a free layer 54, and a capping layer 55 are stacked in sequence in the Z direction. Each of the buffer layer 51 and the capping layer 55 is formed of a nonmagnetic metal material such as Ru, Ta, Cu, and Cr. The free layer 54 is formed of a soft magnetic material such as CoFe, CoFeB, NiFe, and CoNiFe.

[0104] The magnetization-fixed layer 52 may also include an antiferromagnetic layer 521 disposed on the buffer layer 51 and a ferromagnetic layer 522 disposed on the antiferromagnetic layer 521. The antiferromagnetic layer 521 is in contact with the lower surface of the ferromagnetic layer 522, and an exchange coupling is generated between the antiferromagnetic layer 521 and the ferromagnetic layer 522 to fix the magnetization direction of the ferromagnetic layer 522. The magnetization direction of the magnetization-fixed layer 52 is the same direction as the magnetization direction of the ferromagnetic layer 522.

[0105] The antiferromagnetic layer 521 is formed of an antiferromagnetic material such as IrMn and PtMn. The antiferromagnetic layer 73a of the antiferromagnetic portion 73 of the magnetic field generating body 70 and the antiferromagnetic layer 521 may also contain at least one identical element. The ferromagnetic layer 522 is formed of a ferromagnetic material containing one or more elements of Co, Fe, and Ni.

[0106] The MR element 50 has an upper surface 50a at one end in the Z direction, a lower surface 50b at one end in the -Z direction, two side surfaces 50c at both ends in the first direction D1, and two side surfaces 50d at both ends in the second direction D2. The lower surface 50b of the MR element 50 is in contact with the lower electrode 61. Each of the two side surfaces 50c and the two side surfaces 50d is inclined with respect to the lamination direction of the plurality of magnetic films (the direction parallel to the Z direction).

[0107] The magnetic sensor 1 further includes at least one magnetic field generating body 70 configured to generate a bias magnetic field applied to the MR element 50. In the present embodiment, in particular, the magnetic sensor 1 includes two magnetic field generating bodies 70 configured to sandwich the MR element 50. The MR element 50 is disposed between the two magnetic field generating bodies 70 in the first direction D1.

[0108] In the present embodiment, each of the two magnetic field generating bodies 70 is disposed at a predetermined interval from the MR element 50. When viewed from the Z direction, each of the two magnetic field generating bodies 70 does not overlap with the MR element 50.

[0109] Each of the two magnetic field generating bodies 70 includes a ferromagnetic portion 72 made of a ferromagnetic material and an antiferromagnetic portion 73 made of an antiferromagnetic material. In the present embodiment, in particular, the antiferromagnetic portion 73 is disposed on the ferromagnetic portion 72.

[0110] At least a part of each of the two magnetic field generating bodies 70 overlaps with the MR element 50 when viewed from the first direction D1. In the present embodiment, the ferromagnetic portion 72 includes a ferromagnetic layer 72a made of a ferromagnetic material. The ferromagnetic layer 72a is configured to overlap with the MR element 50 when viewed from the first direction D1. The ferromagnetic layer 72a may also be configured to overlap with the entire free layer 54 when viewed from the first direction D1.

[0111] The ferromagnetic layer 72a is formed of a ferromagnetic material containing one or more elements of Co, Fe, and Ni. Examples of such ferromagnetic materials include CoFe, CoFeB, and CoNiFe.

[0112] In addition, instead of the ferromagnetic layer 72a, the ferromagnetic portion 72 may include a laminate composed of a plurality of stacked ferromagnetic layers, that is, a laminate composed of ferromagnetic materials that are different from each other in two adjacent layers. Examples of such laminates include a laminate of a Co layer, a CoFe layer, and a Co layer, Co 70 Fe 30 layer, Co 30 Fe 70 layer, and Co 70 Fe 30 layer laminate. In addition, Co 70 Fe 30 represents an alloy composed of 70 atomic% Co and 30 atomic% Fe, and Co 30 Fe 70 represents an alloy composed of 30 atomic% Co and 70 atomic% Fe.

[0113] The antiferromagnetic portion 73 includes an antiferromagnetic layer 73a made of an antiferromagnetic material. The antiferromagnetic layer 73a is disposed above the ferromagnetic layer 72a and is in contact with the ferromagnetic layer 72a. The antiferromagnetic layer 73a is formed of an antiferromagnetic material such as IrMn or PtMn, for example.

[0114] The ferromagnetic layer 72a has magnetization as a whole of the ferromagnetic layer 72a. The magnetization as a whole of the ferromagnetic layer 72a is the magnetization obtained by volume-averaging the vector sum of the magnetic moments per unit of atoms, crystal lattices, etc. in the entire ferromagnetic layer 72a. Hereinafter, the magnetization as a whole of the ferromagnetic layer 72a will be simply referred to as the magnetization of the ferromagnetic layer 72a. The antiferromagnetic layer 73a is in contact with the upper surface of the ferromagnetic layer 72a and is exchange-coupled with the ferromagnetic layer 72a. Thereby, the direction of the magnetization of the ferromagnetic layer 72a is defined.

[0115] In the present embodiment, the entire ferromagnetic portion 72 is substantially composed of the ferromagnetic layer 72a, and the entire antiferromagnetic portion 73 is substantially composed of the antiferromagnetic layer 73a. The antiferromagnetic portion 73 and the ferromagnetic portion 72 are exchange-coupled through the exchange coupling between the antiferromagnetic layer 73a and the ferromagnetic layer 72a. Thereby, the direction of magnetization of the ferromagnetic portion 72 is defined. The direction of magnetization of the ferromagnetic portion 72 is consistent with the direction of magnetization of the ferromagnetic layer 72a. The ferromagnetic portion 72 and the antiferromagnetic portion 73 generate a bias magnetic field based on the magnetization of the ferromagnetic portion 72. The magnetic field generating body 70 configured in this way has high resistance to an interfering magnetic field.

[0116] The two magnetic field generating bodies 70 cooperate to apply a bias magnetic field to the MR element 50. The direction of magnetization of the ferromagnetic portion 72 of one of the two magnetic field generating bodies 70 and the direction of magnetization of the ferromagnetic portion 72 of the other of the two magnetic field generating bodies 70 may also be the same. In this case, the direction of the bias magnetic field generated by one of the two magnetic field generating bodies 70 and the direction of the bias magnetic field generated by the other of the two magnetic field generating bodies 70 become the same direction.

[0117] Each of the two magnetic field generating bodies 70 further includes a buffer layer 71 disposed on the lower surface side (-Z direction side) of the ferromagnetic layer 72a and a cover layer 74 disposed above the antiferromagnetic layer 73a. The buffer layer 71 and the cover layer 74 are formed of nonmagnetic metal materials such as Ru, Ta, Cu, and Cr, for example.

[0118] The magnetic sensor 1 further includes an insulating layer 32 made of an insulating material such as Al2O3 or SiO2 and disposed around the MR element 50 and the two magnetic field generating bodies 70. The insulating layer 32 is interposed between the MR element 50 and the two magnetic field generating bodies 70.

[0119] The magnetic sensor 1 further includes an insulating layer 31 made of an insulating material and interposed between the substrate 30 (refer to ​ ) and the lower electrode 61, and an insulating layer 33 made of an insulating material and interposed between the insulating layer 32 and the two magnetic field generating bodies 70. The insulating layer 33 is also interposed between the two magnetic field generating bodies 70 and the lower electrode 61. The insulating layers 31 and 33 are formed of insulating materials such as Al2O3 or SiO2, for example.

[0120] The upper electrode 62 is disposed above the MR element 50, the two magnetic field generating bodies 70, and the insulating layer 32. The upper surface 50a of the MR element 50 and the upper surfaces of the cover layers 74 of the two magnetic field generating bodies 70 are in contact with the upper electrode 62. The magnetic sensor 1 further includes an unillustrated insulating layer made of an insulating material and disposed above the upper electrode 62.

[0121] So far, the structures of the MR element 50 and the magnetic field generator 70 have been described with respect to one MR element 50. In the present embodiment, the magnetic sensor 1 includes a plurality of MR elements 50. Therefore, the magnetic sensor 1 includes a plurality of magnetic field generators 70.

[0122] ​ The plurality of arrows depicted in a manner overlapping with the plurality of magnetic field generators 70A, and ​ The plurality of arrows depicted in a manner overlapping with the plurality of magnetic field generators 70B substantially represent the magnetization directions of the ferromagnetic portions 72 of the plurality of magnetic field generators 70. Here, the magnetic field generator 70 configured to apply a bias magnetic field to each of the plurality of MR elements 50 of an arbitrary resistance portion is referred to as the magnetic field generator 70 corresponding to the arbitrary resistance portion. In ​ the example shown, the magnetization directions of the ferromagnetic portions 72 of the plurality of magnetic field generators 70A corresponding to the resistance portions R11 and R12 are in the Y direction. The magnetization directions of the ferromagnetic portions 72 of the plurality of magnetic field generators 70A corresponding to the resistance portions R13 and R14 are in the -Y direction.

[0123] In ​ the example shown, the magnetization directions of the ferromagnetic portions 72 of the plurality of magnetic field generators 70B corresponding to the resistance portions R21 and R22 are in the -X direction. The magnetization directions of the ferromagnetic portions 72 of the plurality of magnetic field generators 70B corresponding to the resistance portions R23 and R24 are in the X direction.

[0124] ​ and ​ represent a first example of the magnetization direction of the ferromagnetic portion 72 of the magnetic field generator 70. Other multiple examples of the magnetization direction of the ferromagnetic portion 72 of the magnetic field generator 70 will be described later.

[0125] Next, a method for manufacturing the magnetic sensor 1 of the present embodiment will be described. The method for manufacturing the magnetic sensor 1 includes a step of forming at least one MR element 50 and a step of forming at least one magnetic field generator 70. In the present embodiment, in particular, the step of forming at least one MR element 50 is a step of forming a plurality of MR elements 50, and the step of forming at least one magnetic field generator 70 is a step of forming a plurality of magnetic field generators 70.

[0126] First, the step of forming a plurality of MR elements 50 will be described. In the step of forming a plurality of MR elements 50, first, a plurality of initial MR elements that will later become the plurality of MR elements 50 may be formed. Each of the plurality of initial MR elements includes an initial magnetization fixing layer that will later become the magnetization fixing layer 52, a buffer layer 51, a spacer layer 53, a free layer 54, and a cover layer 55. The initial magnetization fixing layer includes an antiferromagnetic layer 521 and a ferromagnetic layer 522.

[0127] Next, a laser and an external magnetic field containing a component having a specified direction can also be used to fix the direction of magnetization of the initial magnetization fixing layer to the above-mentioned specified direction. Hereinafter, this process will be referred to as the process of fixing the direction of magnetization of the initial magnetization fixing layer or the process of fixing the direction of magnetization of the magnetization fixing layer 52. The specified direction may be the same as the direction of magnetization of the magnetization fixing layer 52. For example, among a plurality of initial MR elements of the plurality of MR elements 50A that will later become the resistance portions R11 and R13 of the first detection circuit 10, a laser is irradiated to the plurality of initial MR elements while applying an external magnetic field in the X direction. The laser is irradiated in such a manner that the temperature of the plurality of initial MR elements irradiated with the laser becomes equal to or higher than the blocking temperature of the antiferromagnetic layer 521 of the initial magnetization fixing layer. The temperature of the plurality of initial MR elements can be adjusted, for example, by the intensity or pulse width of the laser. After the laser is irradiated, when the temperature of the plurality of initial MR elements is lower than the blocking temperature, the direction of magnetization of the initial magnetization fixing layer is fixed to the X direction. Thus, the initial magnetization fixing layer becomes the magnetization fixing layer 52.

[0128] In addition, among a plurality of initial MR elements of the plurality of MR elements 50A that will later become the resistance portions R12 and R14 of the first detection circuit 10, by using an external magnetic field in the -X direction, the direction of magnetization of the initial magnetization fixing layer of each of the plurality of initial MR elements can be fixed to the -X direction. The direction of magnetization of the magnetization fixing layer 52 of each of the plurality of MR elements 50B that form the resistance portions R21 to R24 of the second detection circuit 20 is also fixed by the same method as the magnetization fixing layer 52 of each of the plurality of MR elements 50A.

[0129] The MR element 50 is completed as follows: After fixing the direction of magnetization of the magnetization fixing layer 52, the laminated film is patterned by etching so as to form two side surfaces 50c and two side surfaces 50d in the laminated film. In addition, after the two side surfaces 50c and the two side surfaces 50d are formed in the laminated film, the process of fixing the direction of magnetization of the initial magnetization fixing layer may be performed.

[0130] Next, the process of forming a plurality of magnetic field generating bodies 70 will be described. First, focusing on one MR element 50, the outline of the process of forming two magnetic field generating bodies 70 will be described. First, a photoresist mask is formed on the MR element 50 and the insulating layer 32. Next, the insulating layer 32 is etched. Next, in a state where the photoresist mask remains, an insulating layer 33 and two initial magnetic field generating bodies 70P that will later become two magnetic field generating bodies 70 are sequentially formed. Each of the two initial magnetic field generating bodies 70P includes an initial ferromagnetic portion that will later become the ferromagnetic portion 72, a buffer layer 71, an antiferromagnetic portion 73, and a covering layer 74. The buffer layer 71, the initial ferromagnetic portion, the antiferromagnetic portion 73, and the covering layer 74 are sequentially stacked. Next, the photoresist mask is removed.

[0131] Next, using a laser and an external magnetic field including a component in a specified direction, the magnetization direction of the initial ferromagnetic portion is fixed to the above-specified direction. Hereinafter, this process will be referred to as the process of fixing the magnetization direction of the initial ferromagnetic portion, or the process of fixing the magnetization direction of the ferromagnetic portion 72. The specified direction may be the same as the magnetization direction of the ferromagnetic portion 72. The method of fixing the magnetization direction of the initial ferromagnetic portion is the same as the method of fixing the magnetization direction of the initial magnetization fixing layer. That is, while applying an external magnetic field, each of the two initial magnetic field generating bodies 70P is irradiated with a laser. The laser is irradiated in such a manner that the temperature of the two initial magnetic field generating bodies 70P irradiated with the laser becomes equal to or higher than the blocking temperature of the antiferromagnetic portion 73. The temperature of the two initial magnetic field generating bodies 70P can be adjusted, for example, by the intensity or pulse width of the laser. After the laser is irradiated, when the temperature of the two initial magnetic field generating bodies 70P is lower than the blocking temperature, the magnetization direction of the initial ferromagnetic portion is fixed to the above-specified direction. Thereby, the initial ferromagnetic layer becomes the ferromagnetic portion 72, and the two initial magnetic field generating bodies 70P become two magnetic field generating bodies 70.

[0132] In addition, the intensity of the laser used to fix the magnetization direction of the initial ferromagnetic portion may be smaller than the intensity of the laser used to fix the magnetization direction of the initial magnetization fixing layer. Further, the intensity of the laser used to fix the magnetization direction of the initial ferromagnetic portion is preferably an intensity that suppresses the change in the ratio of the magnetoresistance change to the resistance of the MR element 50, that is, the magnetoresistance change rate.

[0133] Further, in the case where each of the two magnetic field generating bodies 70 has a plurality of side surfaces formed by etching, the process of fixing the magnetization direction of the initial ferromagnetic portion may be performed before forming at least one of the plurality of side surfaces, or may be performed after forming at least one of the plurality of side surfaces.

[0134] In addition, in the present embodiment, the ferromagnetic portion 72 is substantially a ferromagnetic layer 72a. Therefore, the initial ferromagnetic portion is substantially an initial ferromagnetic layer that later becomes the ferromagnetic layer 72a. The process of forming the plurality of magnetic field generators 70 can be described by replacing the ferromagnetic portion 72 and the initial ferromagnetic portion with the ferromagnetic layer 72a and the initial ferromagnetic layer, respectively.

[0135] Next, with reference to ​ the process of fixing the magnetization direction of the initial ferromagnetic layer will be described in more detail. In ​ , the four resistance portions R11 to R14 of the first detection circuit 10 or the four resistance portions R21 to R24 of the second detection circuit 20 are schematically shown. In ​ , the symbol R1 represents the resistance portion corresponding to the resistance portion R11 or the resistance portion R21. The symbol R2 represents the resistance portion corresponding to the resistance portion R12 or the resistance portion R22. The symbol R3 represents the resistance portion corresponding to the resistance portion R13 or the resistance portion R23. The symbol R4 represents the resistance portion corresponding to the resistance portion R14 or the resistance portion R24.

[0136] In ​ , in each of the resistance portions R1 to R4, one MR element 50 is shown representing a plurality of MR elements 50. In addition, a plurality of initial magnetic field generators 70P or a plurality of magnetic field generators 70 configured to sandwich one MR element 50 of each of the resistance portions R1 to R4 are shown representing a plurality of initial magnetic field generators 70P or a plurality of magnetic field generators 70. In addition, in ​ , the first direction D1 and the second direction D2 are also shown. In addition, in the same plurality of figures used in the following description as ​ , the same representation method as ​ is also used.

[0137] ​ The resistance portions R1 to R4 after forming the plurality of initial magnetic field generators 70P are shown. ​ The next process is shown. In this process, while applying a magnetic field component MF1 in one direction (in ​ , the upward direction from bottom to top) parallel to the first direction D1 to the magnetic sensor 1, the plurality of initial magnetic field generators 70P corresponding to the resistance portions R1 and R2 are selectively irradiated with laser light. After the laser light irradiation, the magnetization direction of the initial ferromagnetic layer of each of the irradiated plurality of initial magnetic field generators 70P is fixed in the same direction as the direction of the magnetic field component MF1. As a result, as ​ shows, the plurality of irradiated initial magnetic field generators 70P become the plurality of magnetic field generators 70.

[0138] For example, a laser can also be selectively irradiated onto a plurality of initial magnetic field generating bodies 70P using a mask 101. The mask 101 has a plurality of openings 101a that expose some or all of the plurality of initial magnetic field generating bodies 70P corresponding to the resistance portions R1 and R2. The plurality of MR elements 50 of the resistance portions R1 to R4 and the plurality of initial magnetic field generating bodies 70P corresponding to the resistance portions R3 and R4 are covered by the mask 101. Through the plurality of openings 101a, some or all of the plurality of initial magnetic field generating bodies 70P are irradiated with the laser. In the case of irradiating some of the plurality of initial magnetic field generating bodies 70P with the laser, for example, while moving the magnetic sensor 1 using a stage, all of the initial magnetic field generating bodies 70P corresponding to the resistance portions R1 and R2 are irradiated with the laser.

[0139] In addition, the laser is not irradiated onto the plurality of MR elements 50, but the temperature of the plurality of MR elements 50 may also increase during the laser irradiation. However, the temperature of the plurality of MR elements 50 does not exceed the blocking temperature of the antiferromagnetic layer 521.

[0140] ​ Indicates the next process. In this process, while applying a magnetic field component MF2 in another direction (in ​ , the direction from top to bottom) parallel to the first direction D1 to the magnetic sensor 1, a plurality of initial magnetic field generating bodies 70P corresponding to the resistance portions R3 and R4 are selectively irradiated with the laser. After the laser irradiation, the magnetization directions of the initial ferromagnetic layers of the irradiated plurality of initial magnetic field generating bodies 70P are fixed in the same direction as the direction of the magnetic field component MF2. Thus, as ​ shown, the irradiated plurality of initial magnetic field generating bodies 70P become a plurality of magnetic field generating bodies 70.

[0141] Same as the process shown in ​ For example, a mask 102 can also be used to selectively irradiate a plurality of initial magnetic field generating bodies 70P with the laser. The mask 102 has a plurality of openings 102a that expose some or all of the plurality of initial magnetic field generating bodies 70P corresponding to the resistance portions R3 and R4. The plurality of MR elements 50 of the resistance portions R1 to R4 and the plurality of magnetic field generating bodies 70 corresponding to the resistance portions R1 and R2 are covered by the mask 102. Through the plurality of openings 102a, some or all of the plurality of initial magnetic field generating bodies 70P are irradiated with the laser. In the case of irradiating some of the plurality of initial magnetic field generating bodies 70P with the laser, for example, while moving the magnetic sensor 1 using a stage, all of the initial magnetic field generating bodies 70P corresponding to the plurality of MR elements 50 of the resistance portions R3 and R4 are irradiated with the laser.

[0142] In addition, no laser is irradiated on the resistance portions R1 and R2. However, during the laser irradiation, the temperatures of the plurality of magnetic field generators 70 corresponding to the resistance portions R1 and R2 may also increase. However, the temperatures of the plurality of magnetic field generators 70 corresponding to the resistance portions R1 and R2 are not higher than the blocking temperature of the antiferromagnetic portion 73.

[0143] The method for manufacturing the magnetic sensor 1 may further include a step of annealing the stack of the plurality of MR elements 50 in which the magnetization directions of the magnetization fixing layers 52 are respectively fixed and the plurality of magnetic field generators 70 in which the magnetization directions of the ferromagnetic portions 72 are respectively fixed by heating at a specified temperature. The annealing treatment can also be performed using an electric furnace, for example. By performing the annealing treatment, the magnetization directions of the magnetization fixing layer 52 and the ferromagnetic portion 72 can be stabilized. As a result, the characteristic variations of the magnetic sensor 1 after the magnetic sensor 1 is completed can be suppressed.

[0144] Next, the effects of the magnetic sensor 1 of the present embodiment will be described. As ​ shown, in the present embodiment, several of the plurality of MR elements 50A of the resistance portion R11 and several of the plurality of MR elements 50A of the resistance portion R14 are adjacent to each other without other MR elements 50A capable of detecting the magnetoresistive effect interposed therebetween. Here, the group of the plurality of magnetic field generators 70A that apply a bias magnetic field to several of the plurality of MR elements 50A of the resistance portion R11 and several of the plurality of MR elements 50A of the resistance portion R11 is referred to as the first group. In addition, the group of the plurality of magnetic field generators 70A that apply a bias magnetic field to several of the plurality of MR elements 50A of the resistance portion R14 and several of the plurality of MR elements 50A of the resistance portion R14 is referred to as the second group. There is no group of other MR elements 50 and other magnetic field generators 70 capable of detecting the magnetoresistive effect interposed between the first group and the second group.

[0145] In addition, the MR element 50 connected to an arbitrary electrode and capable of detecting the resistance value corresponds to other MR elements 50 capable of detecting the magnetoresistive effect. On the other hand, as an MR element that does not correspond to the MR element 50 capable of detecting the magnetoresistive effect, for example, there are the following first to third MR elements. The first MR element is an MR element that is not connected to any electrode and cannot detect the resistance value of the MR element. The second MR element is a CIP (Current In Plane) type GMR element in which current flows in a direction substantially parallel to the plane of each layer constituting the MR element, that is, a GMR element having a thick conductive film formed thereon. The third MR element is an MR element in which the structure of the MR element is incomplete, and therefore, even if the direction or intensity of the applied magnetic field changes, the resistance value does not change. As such an MR element, for example, a TMR element or a GMR element in which the magnetization direction of the magnetization fixing layer is not fixed.

[0146] In the magnetic sensor 1, there is a requirement that the magnetization directions of the free layers 54 in the first group and the magnetization directions of the free layers 54 in the second group are different from each other when there is no target magnetic field. In contrast, in the present embodiment, the magnetization direction of the ferromagnetic portion 72 of the magnetic field generating body 70A in the first group and the magnetization direction of the ferromagnetic portion 72 of the magnetic field generating body 70A in the second group are different from each other. In the present embodiment, in particular, the magnetization direction of the ferromagnetic portion 72 of the magnetic field generating body 70A in the first group and the magnetization direction of the ferromagnetic portion 72 of the magnetic field generating body 70A in the second group may also be in opposite directions. Therefore, the direction of the main component of the bias magnetic field generated by the magnetic field generating body 70A in the first group and the direction of the main component of the bias magnetic field generated by the magnetic field generating body 70A in the second group are also in opposite directions. Thus, according to the present embodiment, when there is no target magnetic field, the magnetization directions of the free layers 54 in the first group and the magnetization directions of the free layers 54 in the second group can be made different from each other.

[0147] In addition, as ​ shown, in the present embodiment, several of the plurality of MR elements 50A of the resistance portion R12 and several of the plurality of MR elements 50A of the resistance portion R13 are adjacent to each other without interposing other MR elements 50A capable of detecting the magnetoresistive effect. Here, a group of a plurality of magnetic field generating bodies 70A that apply a bias magnetic field to several of the plurality of MR elements 50A of the resistance portion R12 and several of the plurality of MR elements 50A of the resistance portion R12 is referred to as a third group. In addition, a group of a plurality of magnetic field generating bodies 70A that apply a bias magnetic field to several of the plurality of MR elements 50A of the resistance portion R13 and several of the plurality of MR elements 50A of the resistance portion R13 is referred to as a fourth group. There is no group of other MR elements 50 and other magnetic field generating bodies 70 capable of detecting the magnetoresistive effect interposed between the third group and the fourth group. The third group may be adjacent to one of the first group and the second group with a predetermined interval therebetween. The fourth group may be adjacent to the other of the first group and the second group with a predetermined interval therebetween.

[0148] The above description regarding the plurality of magnetic field generating bodies 70A corresponding to the resistance portions R11 and R14 is also applicable to the plurality of magnetic field generating bodies 70A corresponding to the resistance portions R12 and R13. In addition, the above description regarding the resistance portions R11 to R14 is also applicable to the resistance portions R21 to R24.

[0149] In addition, although not shown, one or two of the resistance portions R11 to R14 (hereinafter referred to as the first resistance portion) are adjacent to one or two of the resistance portions R21 to R24 (hereinafter referred to as the second resistance portion). In the magnetic sensor 1, there may be a requirement that, when there is no target magnetic field, the magnetization directions of the free layers 54 of the plurality of MR elements 50A in the first resistance portion are different from the magnetization directions of the free layers 54 of the plurality of MR elements 50B in the second resistance portion.

[0150] In the present embodiment, the magnetization directions of the ferromagnetic portions 72 of the plurality of magnetic field generating bodies 70A corresponding to the first resistance portion and the magnetization directions of the ferromagnetic portions 72 of the plurality of magnetic field generating bodies 70B corresponding to the second resistance portion are different from each other. In the present embodiment, in particular, the magnetization directions of the ferromagnetic portions 72 of the plurality of magnetic field generating bodies 70A corresponding to the first resistance portion and the magnetization directions of the ferromagnetic portions 72 of the plurality of magnetic field generating bodies 70B corresponding to the second resistance portion may be orthogonal. Therefore, the directions of the main components of the bias magnetic fields generated by the plurality of magnetic field generating bodies 70A corresponding to the first resistance portion and the directions of the main components of the bias magnetic fields generated by the plurality of magnetic field generating bodies 70B corresponding to the second resistance portion are also orthogonal to each other. Thus, according to the present embodiment, when there is no target magnetic field, the magnetization directions of the free layers 54 of the plurality of MR elements 50A in the first resistance portion and the magnetization directions of the free layers 54 of the plurality of MR elements 50B in the second resistance portion can be made different from each other.

[0151] Next, a second to twelfth example of the arrangement of the resistance portions R11 to R14 and R21 to R24 in the substrate 30 and the magnetization directions of the ferromagnetic portions 72 of the magnetic field generating body 70 will be described.

[0152] ​ The second example is shown. In ​ resistance portions R1 to R4 shown in ​ are used to represent the resistance portions R11 to R14 and R21 to R24. In the second example, the arrangement of the resistance portions R1 to R4 is the same as the first example of the arrangement of the resistance portions R11 to R14 shown in ​ and the first example of the arrangement of the resistance portions R21 to R24 shown in ​ . That is, ​ shows that the arrangement of the resistance portions R1 to R4 is the same as the arrangement of the resistance portions R11 to R14 shown in ​ and the arrangement of the resistance portions R21 to R24 shown in ​ .

[0153] In addition, in ​ , a plurality of arrows respectively depicted so as to overlap the resistance portions R1 to R4 indicate the magnetization directions of the magnetization fixing layers 52 in the respective resistance portions R1 to R4.​ Indicates that the magnetization directions of the magnetization fixed layers 52 in the respective resistance portions R1 to R4 are the same as ​ the magnetization directions of the magnetization fixed layers in the respective resistance portions R11 to R14 shown and ​ the magnetization directions of the magnetization fixed layers in the respective resistance portions R21 to R24 shown. That is, as described above, the magnetization directions of the magnetization fixed layers 52 in the respective resistance portions R11 and R13 are in the X direction, and the main component directions of the magnetization of the magnetization fixed layers in the respective resistance portions R21 and R23 are in the Y direction. In ​ , an arrow in one direction parallel to the second direction D2 (in ​ , the direction from the resistance portion R1 toward the resistance portion R2) indicates the magnetization direction of the magnetization fixed layer 52 in each of the resistance portions R1 and R3 corresponding to the resistance portions R11, R13 or the resistance portions R21, R23.

[0154] In addition, as described above, the magnetization directions of the magnetization fixed layers in the respective resistance portions R12 and R14 are in the -X direction, and the magnetization directions of the magnetization fixed layers in the respective resistance portions R22 and R24 are in the -Y direction. In ​ , an arrow in the other direction parallel to the second direction D2 (in ​ , the direction from the resistance portion R2 toward the resistance portion R1) indicates the magnetization direction of the magnetization fixed layer 52 in each of the resistance portions R2 and R4 corresponding to the resistance portions R12, R14 or the resistance portions R22, R24.

[0155] In addition, in ​ , a plurality of arrows depicted so as to overlap with the plurality of magnetic field generating bodies 70 respectively indicate the magnetization directions of the ferromagnetic portions 72 of the respective magnetic field generating bodies 70. In the second example, the magnetization directions of the ferromagnetic portions 72 of the respective magnetic field generating bodies 70 corresponding to the resistance portions R1 and R4 are in one direction parallel to the first direction D1 (in ​ , the direction from the resistance portion R4 toward the resistance portion R1). That is, the magnetization directions of the ferromagnetic portions 72 of the respective magnetic field generating bodies 70A corresponding to the resistance portions R11 and R14 are in the -Y direction, and the magnetization directions of the ferromagnetic portions 72 of the respective magnetic field generating bodies 70B corresponding to the resistance portions R21 and R24 are in the X direction.

[0156] In addition, in the second example, the magnetization directions of the ferromagnetic portions 72 of the respective magnetic field generating bodies 70 corresponding to the resistance portions R2 and R3 are in the other direction parallel to the first direction D1 (in ​In (the direction from the resistance part R2 toward the resistance part R3). That is, the magnetization directions of the ferromagnetic parts 72 of the plurality of magnetic field generating bodies 70A corresponding to the resistance parts R12 and R13 are in the Y direction, and the magnetization directions of the ferromagnetic parts 72 of the plurality of magnetic field generating bodies 70B corresponding to the resistance parts R22 and R23 are in the -X direction.

[0157] As described above, in the second example, the arrangements of the resistance parts R1 to R4 are the same as those in ​ and ​ shown in the first example, but the magnetization directions of the ferromagnetic parts 72 of the magnetic field generating bodies 70 are different from those in the first example.

[0158] In addition, in the same plurality of figures used in the following descriptions as ​ the same, the arrangements of the resistance parts R1 to R4 (resistance parts R11 to R14, R21 to R24) and the magnetization directions of the ferromagnetic parts 72 of the magnetic field generating bodies 70 also use the same representation method as ​ the same. In addition, in the following descriptions, the description of the correspondence between the resistance parts R1 to R4 and the resistance parts R11 to R14, R21 to R24, and the correspondence between the first and second directions D1 and D2 and the X and Y directions is omitted.

[0159] ​ Figure 3 shows the third example. In the third example, the magnetization directions of the ferromagnetic parts 72 of the magnetic field generating bodies 70 are the same as those in ​ and ​ shown in the first example, but the arrangements of the resistance parts R3 and R4 are different from those in the first example. That is, in the third example, the resistance parts R3 and R4 are respectively arranged in front of one direction parallel to the first direction D1 with respect to the resistance parts R1 and R2.

[0160] ​ Figure 4 shows the fourth example. In the fourth example, the arrangements of the resistance parts R1 to R4 and the magnetization directions of the ferromagnetic parts 72 of the plurality of magnetic field generating bodies 70 corresponding to the resistance parts R1 and R3 are the same as those in ​ shown in the third example, but the magnetization directions of the ferromagnetic parts 72 of the plurality of magnetic field generating bodies 70 corresponding to the resistance parts R2 and R4 are different from those in the third example. That is, in the fourth example, the magnetization directions of the ferromagnetic parts 72 of the plurality of magnetic field generating bodies 70 corresponding to the resistance part R2 are the same as the magnetization directions of the ferromagnetic parts 72 of the plurality of magnetic field generating bodies 70 corresponding to the resistance part R3, and are in the opposite direction to the third example. In addition, the magnetization directions of the ferromagnetic parts 72 of the plurality of magnetic field generating bodies 70 corresponding to the resistance part R4 are the same as the magnetization directions of the ferromagnetic parts 72 of the plurality of magnetic field generating bodies 70 corresponding to the resistance part R1, and are in the opposite direction to the third example.

[0161] ​ Represents the fifth example. In the fifth example, the direction of magnetization of the ferromagnetic portion 72 of the magnetic field generating body 70 is the same as that in ​ and ​ the first example shown, but the arrangement of the resistance portions R1 to R4 is different from that in the first example. That is, in the fifth example, the resistance portions R1 to R4 are arranged in sequence in one direction parallel to the second direction D2.

[0162] ​ Represents the sixth example. In the sixth example, the arrangement of the resistance portions R1 to R4 is the same as that in ​ the fifth example shown, and the direction of magnetization of the ferromagnetic portion 72 of the magnetic field generating body 70 is the same as that in ​ the fourth example shown.

[0163] ​ Represents the seventh example. In the seventh example, the arrangement of the resistance portions R1 and R2 and the direction of magnetization of the ferromagnetic portion 72 of the magnetic field generating body 70 are the same as those in ​ the fifth example shown, but the arrangement of the resistance portions R3 and R4 is different from that in the fifth example. That is, in the seventh example, the resistance portion R4 is arranged in the second direction D2 at a position sandwiching the resistance portion R2 between it and the resistance portion R1. The resistance portion R3 is arranged in the second direction D2 at a position sandwiching the resistance portion R4 between it and the resistance portion R2.

[0164] ​ Represents the eighth example. In the eighth example, the arrangement of the resistance portions R1 to R4 is the same as that in ​ the seventh example shown, and the direction of magnetization of the ferromagnetic portion 72 of the magnetic field generating body 70 is the same as that in ​ the sixth example shown.

[0165] ​ Represents the ninth example. In the ninth example, the arrangement of the resistance portions R1 and R4 and the direction of magnetization of the ferromagnetic portion 72 of the magnetic field generating body 70 are the same as those in ​ the fifth example shown, but the arrangement of the resistance portions R2 and R3 is different from that in the fifth example. That is, in the ninth example, the resistance portions R2 and R3 are arranged between the resistance portions R1 and R4. The resistance portion R2 is arranged at a position closer to the resistance portion R4 than the resistance portion R1. The resistance portion R3 is arranged at a position closer to the resistance portion R1 than the resistance portion R4.

[0166] ​ Represents the tenth example. In the tenth example, the direction of magnetization of the ferromagnetic portion 72 of the magnetic field generating body 70 is the same as that in ​ the sixth example shown, but the arrangement of the resistance portions R1 to R4 is different from that in the sixth example. That is, in the tenth example, the resistance portions R1 to R4 are arranged in the order of the resistance portion R1, the resistance portion R3, the resistance portion R4, and the resistance portion R2 in one direction parallel to the second direction D2.

[0167] ​ Denotes the eleventh example. In the eleventh example, the arrangement of the resistance portions R1 to R4 is the same as that in ​ the ninth example shown, and the magnetization direction of the ferromagnetic portion 72 of the magnetic field generating body 70 is the same as that in ​ the sixth example shown.

[0168] ​ Denotes the twelfth example. In the twelfth example, the arrangement of the resistance portions R1 to R4 is the same as that in ​ the tenth example shown, and the magnetization direction of the ferromagnetic portion 72 of the magnetic field generating body 70 is the same as that in ​ the fifth example shown.

[0169] [Modified Example]

[0170] Next, first to fifth modified examples of the magnetic sensor 1 of the present embodiment will be described. First, with reference to ​ the first modified example will be described. ​ is a cross-sectional view showing the main part of the first modified example of the magnetic sensor 1. In the first modified example, the magnetization fixing layer 52 of the MR element 50 does not include ​ the antiferromagnetic layer 521 shown. In the first modified example, the magnetization fixing layer 52 may also include a soft magnetic layer made of a ferromagnetic material containing one or more elements of Co, Fe, and Ni. In this case, by using a specific material such as Ta for the buffer layer 51 and reducing the thickness of the soft magnetic layer, the coercive force of the magnetization fixing layer 52 can also be increased. Alternatively, the magnetization fixing layer 52 may be made of a hard magnetic material containing elements such as Pt, Sm, and Nd.

[0171] In the process of fixing the magnetization direction of the magnetization fixing layer 52 in the first modified example, a laser and an external magnetic field including a component having a specified direction are used to fix the magnetization direction of the initial magnetization fixing layer to the above-mentioned specified direction. Among a plurality of initial MR elements of a plurality of MR elements 50A that will later become the resistance portions R11 and R13 constituting the first detection circuit 10, while applying an external magnetic field in the X direction, a laser is irradiated to the plurality of initial MR elements. By irradiating the laser, the coercive force of the magnetization fixing layer 52 of each of the plurality of initial MR elements is reduced, and the magnetization direction of the magnetization fixing layer 52 is inclined toward the X direction. After irradiating the laser, the magnetization direction of the initial magnetization fixing layer is fixed to the X direction. Thus, the initial magnetization fixing layer becomes the magnetization fixing layer 52. In addition, the coercive force of the magnetization fixing layer 52 of each of the plurality of initial MR elements that are not irradiated with the laser is maintained at such a level that the magnetization direction of the magnetization fixing layer 52 does not tilt due to the external magnetic field.

[0172] In addition, among a plurality of initial MR elements of the plurality of MR elements 50A that later become the resistance portions R12 and R14 constituting the first detection circuit 10, by using an external magnetic field in the -X direction, the magnetization directions of the initial magnetization fixing layers of the plurality of initial MR elements can be fixed to the -X direction. The magnetization directions of the magnetization fixing layers 52 of the respective MR elements 50B of each of the resistance portions R21 to R24 constituting the second detection circuit 20 are also fixed by the same method as the magnetization fixing layers 52 of the respective MR elements 50A.

[0173] Next, refer to ​ and explain the second modification example. ​ FIG. is a cross-sectional view showing a main part of a second modification example of the magnetic sensor 1. In the second modification example, an antiferromagnetic layer 73a, a ferromagnetic layer 72a, and a cover layer 74 are sequentially arranged on the buffer layer 71. In the second modification example, the antiferromagnetic layer 73a is in contact with the lower surface of the ferromagnetic layer 72a and exchange-couples with the ferromagnetic layer 72a. Thereby, the magnetization direction of the ferromagnetic layer 72a is specified.

[0174] Next, refer to ​ and explain the third modification example. ​ FIG. is a cross-sectional view showing a main part of a third modification example of the magnetic sensor 1. In the third modification example, the antiferromagnetic portion 73 includes, in addition to the antiferromagnetic layer 73a, an antiferromagnetic layer 73b. The antiferromagnetic layer 73b is disposed between the buffer layer 71 and the ferromagnetic layer 72a. The antiferromagnetic layer 73b is formed of an antiferromagnetic material such as IrMn or PtMn, for example.

[0175] The antiferromagnetic layer 73b is in contact with the lower surface of the ferromagnetic layer 72a and exchange-couples with the ferromagnetic layer 72a. In addition, as described above, the antiferromagnetic layer 73a is in contact with the upper surface of the ferromagnetic layer 72a and exchange-couples with the ferromagnetic layer 72a. In the third modification example, the magnetization direction of the ferromagnetic layer 72a is specified by the exchange coupling of the antiferromagnetic layer 73a and the antiferromagnetic layer 73b with the ferromagnetic layer 72a.

[0176] Next, refer to ​ and explain the fourth modification example. ​ FIG. is a cross-sectional view showing a main part of a fourth modification example of the magnetic sensor 1. In the fourth modification example, the ferromagnetic portion 72 includes, in addition to the ferromagnetic layer 72a, a ferromagnetic layer 72b. The ferromagnetic layer 72b is disposed between the buffer layer 71 and the ferromagnetic layer 72a. The ferromagnetic layer 72b is formed of a ferromagnetic material containing one or more elements of Co, Fe, and Ni. In the fourth modification example, the ferromagnetic layer 72b has magnetization in the same direction as the magnetization of the ferromagnetic layer 72a.

[0177] In the fourth modification example, the ferromagnetic layer 72a can also be formed of a ferromagnetic material capable of increasing the exchange coupling energy with the antiferromagnetic layer 73a, and the ferromagnetic layer 72b can be formed of a ferromagnetic material having a saturation magnetic flux density larger than that of the ferromagnetic material constituting the ferromagnetic layer 72a. In this case, it is possible to increase the exchange coupling energy between the ferromagnetic portion 72 composed of the ferromagnetic layers 72a and 72b and the antiferromagnetic layer 73a, increase the intensity of the bias magnetic field generated by the magnetic field generating body 70, and miniaturize the magnetic field generating body 70. As an example of the ferromagnetic layer 72a, Co 70 Fe 30 layer can be cited. As an example of the ferromagnetic layer 72b, Co 30 Fe 70 layer can be cited. In addition, Co 70 Fe 30 represents an alloy composed of 70 atomic% Co and 30 atomic% Fe, and Co 30 Fe 70 represents an alloy composed of 30 atomic% Co and 70 atomic% Fe.

[0178] Next, a description will be given with reference to ​ the fifth modification example. ​ is a cross-sectional view showing the main part of the fifth modification example of the magnetic sensor 1. In the fifth modification example, the ferromagnetic portion 72 includes, in addition to the ferromagnetic layer 72a, a ferromagnetic layer 72b. The ferromagnetic layer 72b is disposed between the buffer layer 71 and the ferromagnetic layer 72a. The ferromagnetic layer 72b is formed of a ferromagnetic material containing one or more elements of Co, Fe, and Ni. The ferromagnetic layer 72a and the ferromagnetic layer 72b may be formed of the same ferromagnetic material or different ferromagnetic materials.

[0179] In addition, in the fifth modification example, the magnetic field generating body 70 further includes a nonmagnetic layer 75 disposed between the ferromagnetic layer 72a and the ferromagnetic layer 72b. The nonmagnetic layer 75 is formed of a nonmagnetic metal material such as Ru, for example.

[0180] In the fifth modification example, the ferromagnetic layer 72a and the ferromagnetic layer 72b can also be ferromagnetically exchange-coupled via the nonmagnetic layer 75 so that the directions of their magnetizations are the same. In this case, the ferromagnetic layer 72a and the ferromagnetic layer 72b have magnetizations in the same direction. The thickness of the nonmagnetic layer 75 is set to a thickness such that the exchange coupling between the ferromagnetic layer 72a and the ferromagnetic layer 72b does not disappear. By providing the nonmagnetic layer 75, it is possible to adjust the coercive force of the ferromagnetic portion 72 or adjust the surface roughness of the substrate of the ferromagnetic layer 72a.

[0181] Alternatively, the ferromagnetic layers 72a and 72b can also be antiferromagnetically exchange-coupled via the nonmagnetic layer 75 by the RKKY interaction. In this case, the magnetization directions of the ferromagnetic layer 72a and the ferromagnetic layer 72b become opposite to each other. The magnetization direction of the ferromagnetic portion 72 is the same as the magnetization direction of the ferromagnetic layer 72a. When the ferromagnetic layers 72a and 72b are antiferromagnetically exchange-coupled, the net moment of the ferromagnetic portion 72 becomes smaller. Therefore, in the ferromagnetic portion 72, the Zeeman energy, which is the energy generated when an external magnetic field acts on the magnetic moment, becomes smaller. As a result, even when an external magnetic field is applied, it is more difficult for the magnetization direction of the ferromagnetic portion 72 to tilt than when the Zeeman energy is large.

[0182] The thickness of the nonmagnetic layer 75 is set such that the magnetization directions of the ferromagnetic layers 72a and 72b based on the RKKY interaction become assumed directions, and the strength of the exchange coupling based on the RKKY interaction becomes an assumed strength.

[0183] [Second Embodiment]

[0184] Next, with reference to ​ and ​ a second embodiment of the present invention will be described. ​ is a top view showing the main part of the magnetic sensor of the present embodiment. ​ is showing ​ a cross-sectional view of a part of the cross-section at the position indicated by the line 24-24 in

[0185] The magnetic sensor 1 of the present embodiment includes a plurality of magnetic field generators 700 instead of the plurality of magnetic field generators 70 in the first embodiment. The functions of the plurality of magnetic field generators 700 and the positional relationship of the plurality of magnetic field generators 700 with respect to the plurality of MR elements 50 are the same as those in the first embodiment.

[0186] Hereinafter, focusing on one MR element 50, the structure of the magnetic field generator 700 will be described. The magnetic sensor 1 of the present embodiment includes two magnetic field generators 700 configured to sandwich the MR element 50. Each of the two magnetic field generators 700 includes a ferromagnetic portion 712 made of a ferromagnetic material.

[0187] The ferromagnetic portion 712 includes a ferromagnetic layer 712a made of a ferromagnetic material. The ferromagnetic layer 712a is configured to overlap with the MR element 50 when viewed from the first direction D1. In the present embodiment, in particular, the ferromagnetic layer 712a is configured to overlap with the entire free layer 54 when viewed from the first direction D1. Further, the MR element 50 is disposed between two ferromagnetic layers 712a that are disposed at a predetermined interval in the first direction D1. The ferromagnetic layer 712a may also be formed of the same material as the ferromagnetic layer 72a in the first embodiment, for example.

[0188] Each of the two magnetic field generating bodies 700 further includes a buffer layer 711 disposed on the lower surface side of the ferromagnetic portion 712. The buffer layer 711 may also be formed of the same material as the buffer layer 71 in the first embodiment, for example.

[0189] The magnetic sensor 1 of the present embodiment further includes a base layer 713 disposed above the MR element 50, the two ferromagnetic layers 712a, and the insulating layer 32, an antiferromagnetic layer 714 disposed above the base layer 713, and a cover layer 715 disposed above the antiferromagnetic layer 714. The antiferromagnetic layer 714 includes two opposing portions 714a that face the two ferromagnetic layers 712a via the base layer 713, and a non-opposing portion 714b that faces the MR element 50 and the insulating layer 32 via the base layer 713 but does not face the two ferromagnetic layers 712a. The two opposing portions 714a are connected to each other by the non-opposing portion 714b.

[0190] The base layer 713 includes two intervening portions 713a interposed between the two ferromagnetic layers 712a and the two opposing portions 714a. The cover layer 715 includes two protective portions 715a disposed above the two opposing portions 714a.

[0191] The base layer 713 is formed of a metal material. In the present embodiment, in particular, the base layer 713 is formed of a ferromagnetic metal material. When the base layer 713 is formed of a ferromagnetic metal material, the base layer 713 may also be formed of the same material as the ferromagnetic layer 712a. Further, in the base layer 713, at least the intervening portion 713a may have magnetism. The portion of the base layer 713 interposed between the MR element 50 and the insulating layer 32 and the antiferromagnetic layer 714 may or may not have magnetism.

[0192] The antiferromagnetic layer 714 may also be formed of the same material as the antiferromagnetic layer 73a in the first embodiment, for example. The cover layer 715 may also be formed of the same material as the cover layer 74 in the first embodiment, for example.

[0193] The buffer layer 711 and the ferromagnetic layer 712a form a first laminate 701. The base layer 713, the antiferromagnetic layer 714, and the cover layer 715 form a second laminate 702. The MR element 50 is disposed between two first laminates 701. The second laminate 702 is disposed above the MR element 50, the insulating layer 32, and two first laminates 701.

[0194] The second laminate 702 includes two laminated portions 702a disposed above two first laminates 701. The two laminated portions 702a each include an intervening portion 713a, an opposing portion 714a, and a protective portion 715a.

[0195] In the laminate formed by the first laminate 701 and the laminated portion 702a disposed above the first laminate 701, the opposing portion 714a is exchange-coupled with the ferromagnetic layer 712a via the intervening portion 713a. Thereby, the direction of magnetization of the ferromagnetic layer 712a is defined.

[0196] Each of the two magnetic field generators 700 further includes an antiferromagnetic portion made of an antiferromagnetic material. In the present embodiment, the entirety of the antiferromagnetic portion is substantially constituted by the opposing portion 714a. Further, in the present embodiment, the entirety of the ferromagnetic portion 712 is substantially constituted by the ferromagnetic layer 712a. By the exchange coupling between the opposing portion 714a and the ferromagnetic layer 712a, the antiferromagnetic portion is exchange-coupled with the ferromagnetic portion 712. Thereby, the direction of magnetization of the ferromagnetic portion 712 is defined. The direction of magnetization of the ferromagnetic portion 712 is the same as the direction of magnetization of the ferromagnetic layer 712a. The ferromagnetic portion 712 and the antiferromagnetic portion generate a bias magnetic field based on the magnetization of the ferromagnetic portion 712. A bias magnetic field is applied to the MR element 50.

[0197] Since the ferromagnetic layer 712a is a part of the first laminate 701 and the opposing portion 714a is a part of the laminated portion 702a, it can also be said that the first laminate 701 and the laminated portion 702a constitute the magnetic field generator 700. The magnetic field generator 700 includes the buffer layer 711, the ferromagnetic layer 712a, the intervening portion 713a, the opposing portion 714a, and the protective portion 715a.

[0198] The MR element 50 is disposed between two magnetic field generators 700. The two magnetic field generators 700 cooperatively apply a bias magnetic field to the MR element 50. The direction of magnetization of the ferromagnetic layer 712a of one of the two magnetic field generators 700 and the direction of magnetization of the ferromagnetic layer 712a of the other of the two magnetic field generators 700 may be the same. In this case, the direction of the bias magnetic field generated by one of the two magnetic field generators 700 and the direction of the bias magnetic field generated by the other of the two magnetic field generators 700 become the same direction.

[0199] In the case where the base layer 713 is formed of the same material as the ferromagnetic layer 712a, the ferromagnetic layer 712a and the intermediate layer portion 713a substantially constitute a single ferromagnetic layer. The opposing portion 714a is in contact with the upper surface of the single ferromagnetic layer and is exchange-coupled with the single ferromagnetic layer.

[0200] The maximum dimension of the ferromagnetic layer 712a in the stacking direction (the direction parallel to the Z direction) of the plurality of magnetic films is larger than the maximum dimension of the base layer 713 in the stacking direction. Further, the maximum dimension of the free layer 54 in the stacking direction is larger than the maximum dimension of the base layer 713 in the stacking direction.

[0201] The upper surface 50a of the MR element 50 faces the non-opposing portion 714b of the antiferromagnetic layer 714. The distance between the non-opposing portion 714b and the lower surface 50b of the MR element 50 is larger than the distance between the upper surface 50a and the lower surface 50b. The distance between the opposing portion 714a of the antiferromagnetic layer 714 and the upper surface of the lower electrode 61 may be the same as the distance between the non-opposing portion 714b and the lower surface 50b, or may be different from the distance between the non-opposing portion 714b and the lower surface 50b. In the latter case, the maximum distance between the opposing portion 714a and the upper surface of the lower electrode 61 may also be larger than the distance between the non-opposing portion 714b and the lower surface 50b.

[0202] The upper surface of the second stacked body 702, that is, the upper surface of the covering layer 715, is in contact with the upper electrode 62. The planar shape (the shape observed from the Z direction) of the second stacked body 702 may be the same as the planar shape of the upper electrode 62, may be smaller than the planar shape of the upper electrode 62, or may be larger than the planar shape of the upper electrode 62.

[0203] So far, the structure of the magnetic field generating body 700 has been described with an eye to one MR element 50. In the present embodiment, the magnetic sensor 1 includes a plurality of MR elements 50. As ​ shown, the plurality of MR elements 50 include two MR elements 50 arranged along the second direction D2. A second stacked body 702 is interposed between the two MR elements 50 and the upper electrode 62 that electrically connects the two MR elements 50. In ​ the example shown, the second stacked body 702 is disposed above the two MR elements 50 and the four first stacked bodies 701. In this example, the second stacked body 702 includes four stacked portions 702a.

[0204] The two MR elements 50 are also electrically connected through the antiferromagnetic layer 714 of the second stacked body 702. Further, the two MR elements 50 are connected in series through the antiferromagnetic layer 714.

[0205] In addition, in the present embodiment, since the magnetic sensor 1 includes a plurality of MR elements 50 and a plurality of magnetic field generators 700, the magnetic sensor 1 includes a plurality of base layers 713, a plurality of antiferromagnetic layers 714, and a plurality of cover layers 715.

[0206] Next, the process of forming the plurality of magnetic field generators 700 in the present embodiment will be described. Here, focusing on one MR element 50, the process of forming two magnetic field generators 700 will be described. First, a photoresist mask is formed over the MR element 50 and the insulating layer 32. Next, the insulating layer 32 is etched. Next, with the photoresist mask remaining, an insulating layer 33, a buffer layer 711, and an initial ferromagnetic layer that will later become the ferromagnetic layer 712a are sequentially formed. Next, the photoresist mask is removed. Next, a base layer 713, an antiferromagnetic layer 714, and a cover layer 715 are sequentially formed over the MR element 50, the ferromagnetic layer 712a, and the insulating layer 32. Next, a process of fixing the magnetization direction of the initial ferromagnetic layer is performed. The process of fixing the magnetization direction of the initial ferromagnetic layer is the same as the process of fixing the magnetization direction of the ferromagnetic portion 72 in the first embodiment. By fixing the magnetization direction of the initial ferromagnetic layer, the initial ferromagnetic layer becomes the ferromagnetic layer 712a, and the magnetic field generator 700 is completed.

[0207] In addition, the ferromagnetic portion 712 of the magnetic field generator 700 in the present embodiment may also be the same as the fourth and fifth modification examples in the first embodiment and include two ferromagnetic layers. In the case where the ferromagnetic portion 712 includes two ferromagnetic layers, similar to the fifth modification example in the first embodiment, the magnetic field generator 700 may also include a non-magnetic layer disposed between the two ferromagnetic layers.

[0208] In addition, the antiferromagnetic portion of the magnetic field generator 700 in the present embodiment may, in addition to including the opposing portion 714a, also include an antiferromagnetic layer disposed between the buffer layer 711 and the ferromagnetic layer 712a, which is the same as the third modification example in the first embodiment.

[0209] Other structures, operations, and effects in the present embodiment are the same as those in the first embodiment.

[0210] [Third Embodiment]

[0211] Next, with reference to ​ and ​ the third embodiment of the present invention will be described. ​ is a top view showing the main part of the magnetic sensor of the present embodiment. ​ is showing ​ a partial cross-sectional view of the cross-section at the position indicated by line 26-26 in

[0212] Hereinafter, focusing on one MR element 50, the points where the structure of the magnetic sensor 1 of the present embodiment is different from that of the first embodiment will be described. In the present embodiment, compared with the first embodiment, the two magnetic field generators 70 are respectively arranged closer to the MR element 50. In the present embodiment, in particular, the two magnetic field generators 70 are respectively arranged so as to straddle the side surface 50c of the MR element 50. A part of each of the two magnetic field generators 70 overlaps with a part of the MR element 50 when viewed from the Z direction. An insulating layer 33 is interposed between the MR element 50 and the two magnetic field generators 70.

[0213] In addition, ​ An example in which the structures of the two magnetic field generators 70 are the same as the structures described with reference to ​ in the first embodiment is shown. However, the structures of the two magnetic field generators 70 may also be the same as any of the multiple modification examples of the first embodiment. In particular, when the structures of the two magnetic field generators 70 are the same as those of the fifth modification example of the first embodiment described with reference to ​ the following effects are achieved in the case where the ferromagnetic layer 72a and the ferromagnetic layer 72b are antiferromagnetically exchange-coupled via the nonmagnetic layer 75. The intensity of the bias magnetic field based on the ferromagnetic layer 72a or the ferromagnetic layer 72b is greater than the intensity of the bias magnetic field based on the entire ferromagnetic portion 72. In the present embodiment, the distance between the free layer 54 of the MR element 50 and the ferromagnetic layer 72a or the ferromagnetic layer 72b is smaller than ​ the example shown. Therefore, a bias magnetic field based on the ferromagnetic layer 72a or the ferromagnetic layer 72b, that is, a bias magnetic field having an intensity greater than the intensity of the bias magnetic field based on the entire ferromagnetic portion 72, can be applied to the free layer 54.

[0214] Next, the process of forming the multiple magnetic field generators 70 in the present embodiment will be described. Here, focusing on one MR element 50, the process of forming the two magnetic field generators 70 will be described. First, a first photoresist mask is formed on the laminated film that will later become the MR element 50. Next, using the first photoresist mask, the laminated film is patterned by etching so as to form two side surfaces 50d (refer to ​ ). Next, with the first photoresist mask remaining, an insulating layer 32 is formed around the laminated film. Next, the first photoresist mask is removed.

[0215] Next, a second photoresist mask is formed on the laminated film and the insulating layer 32. Next, in order to form two side surfaces 50c (refer to ​)In the following manner, a second photoresist mask is used to pattern the stacked film by etching. In this etching, the insulating layer 32 is also etched. By forming two side surfaces 50c on the stacked film, the stacked film becomes the MR element 50. Next, with the second photoresist mask remaining, the insulating layer 33 and two initial magnetic field generators 70P which will later become two magnetic field generators 70 are sequentially formed. The structure of the two initial magnetic field generators 70P is the same as that of the first embodiment. Next, the second photoresist mask is removed.

[0216] Next, the magnetization directions of the initial ferromagnetic portions of the two initial magnetic field generators 70P are fixed. The method of fixing the magnetization directions of the initial ferromagnetic portions in this embodiment is basically the same as that of the first embodiment.

[0217] Hereinafter, with reference to ​ the method of fixing the magnetization directions of the initial ferromagnetic portions in this embodiment will be described in detail. First, as ​ shown, while applying a magnetic field component MF1 in a direction parallel to the first direction D1 (in ​ this case, the upward direction from bottom to top) to the magnetic sensor 1, a laser is selectively irradiated to a plurality of initial magnetic field generators 70P corresponding to the resistance portions R1, R2. After the laser irradiation, the magnetization directions of the initial ferromagnetic portions of the irradiated plurality of initial magnetic field generators 70P are fixed to the same direction as the direction of the magnetic field component MF1. Thus, as ​ shown, the irradiated plurality of initial magnetic field generators 70P become a plurality of magnetic field generators 70.

[0218] For example, a mask 103 can also be used to selectively irradiate a laser to the plurality of initial magnetic field generators 70P. The mask 103 has at least one opening 103a that exposes several or all of the plurality of initial magnetic field generators 70P corresponding to the resistance portions R1, R2. In this embodiment, in particular, several or all of the plurality of MR elements 50 of the resistance portions R1, R2 are also exposed from the at least one opening 103a. The plurality of MR elements 50 of the resistance portions R3, R4 and the plurality of initial magnetic field generators 70P corresponding to the resistance portions R3, R4 are covered by the mask 103. Through the at least one opening 103a, a laser is irradiated to several or all of the plurality of initial magnetic field generators 70P.

[0219] A laser is also irradiated onto a plurality of MR elements 50 of resistance units R1 and R2. Accordingly, the temperature of the plurality of MR elements 50 of resistance units R1 and R2 also rises during the laser irradiation. However, the magnetization directions of the magnetization fixing layers 52 of the respective MR elements 50 of resistance units R1 and R2 are maintained so as not to be inclined by the magnetic field component MF1. In order to maintain the magnetization direction of the magnetization fixing layer 52, a structure in which the magnetization fixing layer 52 is not higher than the blocking temperature of the antiferromagnetic layer 521 may be used, or the blocking temperature of the antiferromagnetic layer 521 may be made higher than the blocking temperature of the antiferromagnetic portion 73. Alternatively, in order to maintain the magnetization direction of the magnetization fixing layer 52, the intensity of the magnetic field component MF1 may be suppressed to a magnitude such that the magnetization direction of the magnetization fixing layer 52 does not incline, or a structure for increasing the coercive force of the magnetization fixing layer 52 or a structure in which the magnetization direction of the magnetization fixing layer 52 is difficult to change may be used.

[0220] ​ represents the following process. In this process, while applying a magnetic field component MF2 in another direction (in ​ , the direction from top to bottom) parallel to the first direction D1 to the magnetic sensor 1, a laser is selectively irradiated onto a plurality of initial magnetic field generating bodies 70P corresponding to the resistance units R3 and R4. After the laser irradiation, the magnetization directions of the initial ferromagnetic portions of the respective irradiated initial magnetic field generating bodies 70P are fixed in the same direction as the direction of the magnetic field component MF2. As a result, as ​ shown, the plurality of irradiated initial magnetic field generating bodies 70P become a plurality of magnetic field generating bodies 70.

[0221] Similar to ​ the process shown, for example, a mask 104 may be used to selectively irradiate a laser onto the plurality of initial magnetic field generating bodies 70P. The mask 104 has at least one opening 104a that exposes some or all of the plurality of initial magnetic field generating bodies 70P corresponding to the resistance units R3 and R4. In the present embodiment, in particular, some or all of the plurality of MR elements 50 of the resistance units R3 and R4 are also exposed from the at least one opening 104a. The plurality of MR elements 50 of the resistance units R1 and R2 and the plurality of magnetic field generating bodies 70 corresponding to the resistance units R1 and R2 are covered by the mask 104. A laser is irradiated onto some or all of the plurality of initial magnetic field generating bodies 70P through the at least one opening 104a.

[0222] The laser is also irradiated onto a plurality of MR elements 50 of the resistance units R3 and R4. Therefore, during the laser irradiation, the temperature of the plurality of MR elements 50 of the resistance units R3 and R4 also rises. However, the magnetization directions of the magnetization fixing layers 52 of the plurality of MR elements 50 of the resistance units R3 and R4 are the same as those of the magnetization fixing layers 52 of the plurality of MR elements 50 of the resistance units R1 and R2, and are maintained without being tilted by the magnetic field component MF2.

[0223] Other structures, operations, and effects in the present embodiment are the same as those in the first embodiment.

[0224] [Modification Example]

[0225] Next, refer to ​ A modification example of the magnetic sensor 1 of the present embodiment will be described. ​ FIG. is a cross-sectional view showing a main part of a modification example of the magnetic sensor 1 of the present embodiment. In the modification example, the magnetization fixing layer 52 of the MR element 50 may include an antiferromagnetic layer 521 disposed on the buffer layer 51, a ferromagnetic layer 523 disposed on the antiferromagnetic layer 521, a nonmagnetic layer 524 disposed on the ferromagnetic layer 523, and a ferromagnetic layer 525 disposed on the nonmagnetic layer 524. The ferromagnetic layers 523 and 525 are formed of a ferromagnetic material containing one or more elements of Co, Fe, and Ni. The nonmagnetic layer 524 is formed of a nonmagnetic metal material such as Ru, for example.

[0226] The antiferromagnetic layer 521 may also be formed of the same material as the antiferromagnetic layer 521 shown in the first embodiment, for example. In addition, as in the first embodiment, the antiferromagnetic layer 73a of the antiferromagnetic portion 73 of the magnetic field generating body 70 and the antiferromagnetic layer 521 may contain the same elements. ​

[0227] The antiferromagnetic layer 521 generates an exchange coupling with the ferromagnetic layer 523 to fix the magnetization direction of the ferromagnetic layer 523. The ferromagnetic layer 523 and the ferromagnetic layer 525 are antiferromagnetically exchange-coupled via the nonmagnetic layer 524. The magnetization directions of the ferromagnetic layer 523 and the ferromagnetic layer 525 are in opposite directions. The magnetization direction of the magnetization fixing layer 52 is the same as the magnetization direction of the ferromagnetic layer 525.

[0228] ​In a modified example, since the magnetization directions of the ferromagnetic layer 523 and the ferromagnetic layer 525 are opposite to each other, the net moment of the magnetization fixing layer 52 becomes smaller. Therefore, in the magnetization fixing layer 52, the energy generated by the external magnetic field acting on the magnetic moment, that is, the Zeeman energy, becomes smaller. Thus, as in the present embodiment, even if the temperature of the plurality of MR elements 50 rises due to the laser for irradiating the initial magnetic field generating body 70P, the magnetization direction of the magnetization fixing layer 52 is less likely to tilt toward the direction of the magnetic field component MF1 or the magnetic field component MF2 than in the case where the Zeeman energy is large.

[0229] In addition, in the modified example, the magnetization amount per unit area Mst1 of the ferromagnetic layer 523 may also be different from the magnetization amount per unit area Mst2 of the ferromagnetic layer 525. In the modified example, it is particularly preferable that the magnetization amount Mst1 is set to be equal to or less than the magnetization amount Mst2. In the case where Mst1 > Mst2, when the temperature of the plurality of MR elements 50 rises due to the laser for irradiating the initial magnetic field generating body 70P, regardless of the magnitudes of the intensities of the magnetic field component MF1 or the magnetic field component MF2, the magnetization direction of the ferromagnetic layer 523 may tilt toward the direction of the magnetic field component MF1 or the magnetic field component MF2.

[0230] On the other hand, in the case where Mst1 ≤ Mst2, when the temperature of the plurality of MR elements 50 rises due to the laser for irradiating the initial magnetic field generating body 70P, in the case where the intensity of the magnetic field component MF1 or the magnetic field component MF2 is small, the magnetization direction of the ferromagnetic layer 523 tilts in the direction opposite to the direction of the magnetic field component MF1 or the magnetic field component MF2. In addition, in this case, in the case where the intensity of the magnetic field component MF1 or the magnetic field component MF2 is large, the magnetization direction of the ferromagnetic layer 523 tilts toward the direction of the magnetic field component MF1 or the magnetic field component MF2. Therefore, in the case where Mst1 ≤ Mst2, by adjusting the intensities of the magnetic field components MF1 and MF2 to an appropriate magnitude, the magnetization direction of the ferromagnetic layer 523 can be made to hardly change. Thus, a change in the magnetization direction of the magnetization fixing layer 52 can be suppressed.

[0231] Furthermore, even in the case where Mst1 > Mst2, when the coercive force of the ferromagnetic layer 523 is large, the magnetization direction of the magnetization fixing layer 52 is less likely to tilt toward the direction of the magnetic field component MF1 or the magnetic field component MF2. In addition, even in the case where Mst1 > Mst2, depending on the magnetostriction of the ferromagnetic layer 523 and the state of the stress around the MR element 50, the magnetization direction of the magnetization fixing layer 52 is less likely to tilt toward the direction of the magnetic field component MF1 or the magnetic field component MF2.

[0232] [Fourth Embodiment]

[0233] Next, with reference to ​ and ​ the fourth embodiment of the present invention will be described. ​ is a top view showing the main part of the magnetic sensor of this embodiment. ​ is a sectional view showing a part of the cross-section at the position indicated by the line 33-33 in ​ .

[0234] Hereinafter, focusing on one MR element 50, the points where the structure of the magnetic sensor 1 in this embodiment is different from that of the second embodiment will be described. In this embodiment, compared with the second embodiment, the two magnetic field generators 700 are respectively arranged closer to the MR element 50. In this embodiment, in particular, the ferromagnetic layer 712a of the ferromagnetic portion 712 of each of the two magnetic field generators 700 is arranged to straddle the side surface 50c of the MR element 50. A part of the ferromagnetic layer 712a overlaps a part of the MR element 50 when viewed from the Z direction. An insulating layer 33 is interposed between the MR element 50 and the two magnetic field generators 700.

[0235] Next, the process of forming the plurality of magnetic field generators 700 in this embodiment will be described. Here, focusing on one MR element 50, the process of forming the two magnetic field generators 700 will be described. First, a photoresist mask is formed on the stacked film that will later become the MR element 50, that is, the stacked film having two side surfaces 50d (refer to ​ ) and the insulating layer 32. Next, using the photoresist mask, the stacked film is patterned by etching so as to form two side surfaces 50c (refer to ​ ) in the stacked film. In this etching, the insulating layer 32 is also etched. By forming two side surfaces 50c in the stacked film, the stacked film becomes the MR element 50.

[0236] Next, in the state where the photoresist mask remains, the insulating layer 33, the buffer layer 711, and the initial ferromagnetic layer that will later become the ferromagnetic layer 712a are sequentially formed. Next, the photoresist mask is removed. Next, a base layer 713, an antiferromagnetic layer 714, and a cover layer 715 are sequentially formed on the MR element 50, the initial ferromagnetic layer, and the insulating layer 32. Next, the process of fixing the magnetization direction of the initial ferromagnetic layer is performed. The process of fixing the magnetization direction of the initial ferromagnetic layer is the same as that of the second embodiment. By fixing the magnetization direction of the initial ferromagnetic layer, the initial ferromagnetic layer becomes the ferromagnetic layer 712a, and the magnetic field generator 700 is completed.

[0237] Other structures, operations, and effects in this embodiment are the same as those in the second embodiment.

[0238] [Modification Example]

[0239] Next, first to third modification examples of the magnetic sensor 1 of the present embodiment will be described. First, refer to ​ to describe the first modification example. ​ is a top view showing the main part of the first modification example of the magnetic sensor 1.

[0240] In the first modification example, each of the plurality of lower electrodes 61 electrically connects two MR elements 50 adjacent in the first direction D1. Each of the plurality of upper electrodes 62 electrically connects two MR elements 50 that are adjacent and disposed above the two lower electrodes 61. Thus, the plurality of MR elements 50 arranged in a row in the first direction D1 are connected in series. In the first modification example, a plurality of connection electrodes electrically connect the plurality of lower electrodes 61 or the plurality of upper electrodes 62 so that the groups of the plurality of MR elements 50 arranged in a row are connected in series.

[0241] In addition, in the first modification example, a second laminate 702 is interposed between two MR elements 50 arranged along the first direction D1 and the upper electrode 62. The two MR elements 50 are also electrically connected through the antiferromagnetic layer 714 (refer to ​ ) of the second laminate 702. In addition, the two MR elements 50 are connected in series through the antiferromagnetic layer 714.

[0242] Next, refer to ​ to describe the second modification example. ​ is a cross-sectional view showing the main part of the second modification example of the magnetic sensor 1. In the second modification example, the first laminate 701 includes a ferromagnetic portion 721A made of a ferromagnetic material instead of the ferromagnetic layer 712a. The ferromagnetic portion 721A has the same function as the ferromagnetic portion 712. The shape and arrangement of the ferromagnetic portion 721A may also be the same as the shape and arrangement of the ferromagnetic layer 712a.

[0243] The second laminate 702 includes a base portion 721B instead of the base layer 713. The shape and arrangement of the base portion 721B may also be the same as the shape and arrangement of the base layer 713. In addition, the base portion 721B includes an interposed portion 721Ba interposed between the ferromagnetic portion 721A and the opposing portion 714a, and a non-interposed portion 721Bb other than the interposed portion 721Ba. The laminated portion 702a includes the interposed portion 721Ba instead of the interposed portion 713a.

[0244] In the second modification example, in particular, the ferromagnetic portion 721A and the base portion 721B are formed of a single ferromagnetic layer 721. In ​ , the boundary between the ferromagnetic portion 721A and the base portion 721B is indicated by a dashed line.

[0245] Next, refer to​ A description will be given of a third modified example. ​ FIG. is a cross-sectional view showing a main part of a third modified example of the magnetic sensor 1. In the third modified example, the base layer 713 is not provided, and the antiferromagnetic layer 714 is disposed on the MR element 50, the two ferromagnetic layers 712a, and the insulating layer 32.

[0246] [Fifth Embodiment]

[0247] Next, a description will be given of a fifth embodiment of the present invention. First, refer to ​ A description will be given of the structure of a magnetic sensor system including the magnetic sensor of this embodiment. ​ FIG. is a perspective view showing the magnetic sensor system 200 in this embodiment.

[0248] The magnetic sensor system 200 includes the magnetic sensor 201 of this embodiment and a magnetic field generation unit 202 that generates a prescribed magnetic field. In this embodiment, the magnetic field generation unit 202 is a magnet configured to apply a part of the generated magnetic field, i.e., a partial magnetic field, to the magnetic sensor 201. This partial magnetic field includes a first magnetic field component Hz parallel to the Z direction and a second magnetic field component Hy parallel to the Y direction.

[0249] As ​ shown, in this embodiment, the magnetization direction of the magnetic field generation unit 202 is the Y direction, and the direction of the second magnetic field component Hy is the -Y direction. When the magnetic field generation unit 202 moves in the Y direction from a prescribed position, the direction of the first magnetic field component Hz becomes the Z direction, and when the magnetic field generation unit 202 moves in the -Y direction from the prescribed position, the direction of the first magnetic field component Hz becomes the -Z direction.

[0250] Next, refer to ​ A description will be given of the schematic structure of the magnetic sensor 201 of this embodiment. ​ FIG. is a circuit diagram showing the circuit structure of the magnetic sensor 201.

[0251] The magnetic sensor 201 includes four resistor parts R31, R32, R33, R34, a power supply port V3, a ground port G3, and two output ports E31, E32. The resistor part R31 is provided between the power supply port V3 and the output port E31. The resistor part R32 is provided between the output port E31 and the ground port G3. The resistor part R33 is provided between the output port E32 and the ground port G3. The resistor part R34 is provided between the power supply port V3 and the output port E32. A prescribed voltage or current is applied to the power supply port V3. The ground port G3 is grounded.

[0252] The resistance units R31 to R34 each include a plurality of MR elements 50. The plurality of MR elements 50 constituting the resistance unit R31 are disposed between the power supply port V3 and the output port E31 in the circuit structure. The plurality of MR elements 50 constituting the resistance unit R32 are disposed between the output port E31 and the ground port G3 in the circuit structure. The plurality of MR elements 50 constituting the resistance unit R33 are disposed between the output port E32 and the ground port G3 in the circuit structure. The plurality of MR elements 50 constituting the resistance unit R34 are disposed between the power supply port V3 and the output port E32 in the circuit structure.

[0253] The structure of the plurality of MR elements 50 is the same as that of the third embodiment. That is, as in the third embodiment ​ shown, the plurality of MR elements 50 each include a buffer layer 51, a magnetization fixed layer 52, a spacer layer 53, a free layer 54, and a cover layer 55.

[0254] In ​ , a plurality of solid arrows respectively drawn so as to overlap with the resistance units R31 to R34 indicate the directions of magnetization of the magnetization fixed layers 52 in the respective resistance units R31 to R34. In ​ the example shown, the directions of the main components of the magnetization of the magnetization fixed layers 52 in the resistance units R31 and R34 are in the X direction. The directions of the main components of the magnetization of the magnetization fixed layers 52 in the resistance units R32 and R33 are in the -X direction. The free layers 54 in the respective resistance units R31 to R34 have shape anisotropy in which the direction of the easy magnetization axis is parallel to the Y direction.

[0255] The magnetic sensor 201 further includes a plurality of magnetic field generators 70. The structure of the plurality of magnetic field generators 70 is the same as that of the third embodiment. The plurality of magnetic field generators 70 include pairs of a plurality of magnetic field generators 70 each composed of two magnetic field generators 70. The above two magnetic field generators 70 are arranged at a predetermined interval in a direction parallel to the Y direction with one MR element 50 interposed therebetween. The two magnetic field generators 70 are configured to apply a bias magnetic field to one MR element 50 located therebetween. The bias magnetic field includes a component in a direction parallel to the Y direction as a main component.

[0256] In ​ , the arrows marked with symbols M31, M32, M33, and M34 respectively indicate the directions of the main components of the bias magnetic fields generated by the plurality of magnetic field generators 70 in the resistance units R31, R32, R33, and R34. The directions of the main components of the bias magnetic fields in the resistance units R31 and R34 are in the Y direction. The directions of the main components of the bias magnetic fields in the resistance units R32 and R33 are in the -Y direction.

[0257] The direction of the bias magnetic field substantially represents the direction of magnetization of the ferromagnetic portions 72 of the plurality of magnetic field generating bodies 70. The direction of magnetization of the ferromagnetic portions 72 of the plurality of magnetic field generating bodies 70 corresponding to the resistance portions R31 and R34 is the Y direction. The direction of magnetization of the ferromagnetic portions 72 of the plurality of magnetic field generating bodies 70 corresponding to the resistance portions R32 and R33 is the -Y direction.

[0258] In ​ , a plurality of hollow arrows respectively depicted so as to overlap with the resistance portions R31 to R34 indicate the directions of magnetization of the free layers in the respective resistance portions R31 to R34 when no partial magnetic field is applied to the magnetic sensor 201. The direction of the main component of the magnetization of the free layers in the resistance portions R31 and R34 may be the Y direction or the same as the direction of the main component of the bias magnetic field in the resistance portions R31 and R34. The direction of the main component of the magnetization of the free layers in the resistance portions R32 and R33 may be the -Y direction or the same as the direction of the main component of the bias magnetic field in the resistance portions R32 and R33.

[0259] Next, with reference to ​ the structure of the magnetic sensor 201 will be specifically described. ​ is a perspective view showing a part of the magnetic sensor 201. ​ is a top view showing a part of the magnetic sensor 201. ​ is a side view showing a part of the magnetic sensor 201.

[0260] The magnetic sensor 201 further includes a substrate 230. The magnetic sensor 201 is formed by forming a plurality of components other than the substrate 230 on the substrate 230.

[0261] The magnetic sensor 201 further includes at least one magnetic yoke made of a soft magnetic material. When viewed from the Z direction, at least one magnetic yoke has a shape that is long in the Y direction. In addition, at least one magnetic yoke generates a magnetic field component in a direction parallel to the X direction based on ​ the first magnetic field component Hz shown.

[0262] As ​ shown, in the present embodiment, particularly as at least one magnetic yoke, the magnetic sensor 201 includes a plurality of magnetic yokes 250 arranged along the X direction. Each of the plurality of magnetic yokes 250 has, for example, a rectangular parallelepiped shape that is long in the Y direction. The shapes of the plurality of magnetic yokes 250 are the same. Each of the plurality of magnetic yokes 250 has a first end face 250a and a second end face 250b located at both ends in a direction parallel to the X direction. In each of the plurality of magnetic yokes 250, the first end face 250a is located at one end in the -X direction, and the second end face 250b is located at one end in the X direction.

[0263] Each of the plurality of MR elements 50 is disposed at a position where the magnetic field component generated by the plurality of magnetic yokes 250 is applied. In the present embodiment, in particular, each of the MR elements 50 is disposed near the -Z direction end of each of the plurality of magnetic yokes 250. Further, the plurality of MR elements 50 are arranged in plural numbers along each of the first end faces 250a or the second end faces 250b of the plurality of magnetic yokes 250. Hereinafter, the plurality of MR elements 50 arranged along the first end face 250a are denoted by the symbol 50C, and the plurality of MR elements 50 arranged along the second end face 250b are denoted by the symbol 50D. The directions of the magnetic field components received by the plurality of MR elements 50C and the directions of the magnetic field components received by the plurality of MR elements 50D are opposite to each other.

[0264] When viewed from the Z direction, the plurality of MR elements 50C and the plurality of MR elements 50D may or may not overlap with the plurality of magnetic yokes 250. In ​ the example shown, the plurality of MR elements 50C and the plurality of MR elements 50D are arranged so as not to overlap with the plurality of magnetic yokes 250 when viewed from the Z direction.

[0265] As ​ and ​ shown, the plurality of magnetic field generators 70 configured to sandwich the MR element 50C are denoted by the symbol 70C, and the plurality of magnetic field generators configured to sandwich the MR element 50D are denoted by the symbol 70D. The magnetic sensor 201 further includes a plurality of magnetic yokes 90C and a plurality of magnetic yokes 90D each including a magnetic layer made of a soft magnetic material. The plurality of magnetic yokes 90C include pairs of the plurality of magnetic yokes 90C each composed of two magnetic yokes 90C. The two magnetic yokes 90C are disposed on both sides of one MR element 50C in a direction parallel to the X direction. The plurality of magnetic yokes 90D include pairs of the plurality of magnetic yokes 90D each composed of two magnetic yokes 90D. The two magnetic yokes 90D are disposed on both sides of one MR element 50D in a direction parallel to the X direction.

[0266] The plurality of magnetic yokes 90C have a function of guiding the magnetic field component generated by the plurality of magnetic yokes 250 to the plurality of MR elements 50C. The plurality of magnetic yokes 90D have a function of guiding the magnetic field component generated by the plurality of magnetic yokes 250 to the plurality of MR elements 50D.

[0267] The magnetic sensor 201 further includes a wiring portion 211 that electrically connects the plurality of MR elements 50C and a wiring portion 212 that electrically connects the plurality of MR elements 50D. The wiring portions 211 and 212 are each composed of a plurality of lower electrodes 61, a plurality of upper electrodes 62, and a plurality of connection electrodes. Further, the lower electrodes 61 and the upper electrodes 62 are shown in ​ described later.

[0268] The wiring section 211 includes a first wiring that electrically connects a plurality of MR elements 50C in which the direction of the main component of the magnetization of the magnetization fixing layer 52 is in the X direction, and a second wiring that electrically connects a plurality of MR elements 50C in which the direction of the main component of the magnetization of the magnetization fixing layer 52 is in the -X direction. The resistance section R31 is formed by the plurality of MR elements 50C electrically connected by the first wiring. The resistance section R32 is formed by the plurality of MR elements 50C electrically connected by the second wiring.

[0269] The wiring section 212 includes a third wiring that electrically connects a plurality of MR elements 50D in which the direction of the main component of the magnetization of each magnetization fixing layer 52 is in the -X direction, and a fourth wiring that electrically connects a plurality of MR elements 50D in which the direction of the main component of the magnetization of each magnetization fixing layer 52 is in the X direction. The resistance section R33 is formed by the plurality of MR elements 50D electrically connected by the third wiring. The resistance section R34 is formed by the plurality of MR elements 50D electrically connected by the fourth wiring.

[0270] Next, the operation of the magnetic sensor 201 will be described. When the first magnetic field component Hz does not exist, as a result, in a state where the magnetic field component generated by the plurality of magnetic yokes 250 also does not exist, the magnetization directions of the free layers 54 of the plurality of MR elements 50C and the plurality of MR elements 50D each become parallel to the Y direction.

[0271] When the direction of the first magnetic field component Hz is in the Z direction, the direction of the magnetic field component received by each of the plurality of MR elements 50C constituting the resistance sections R31 and R32 becomes the X direction, and the direction of the magnetic field component received by each of the plurality of MR elements 50D constituting the resistance sections R33 and R34 becomes the -X direction. In this case, the magnetization directions of the free layers 54 of the plurality of MR elements 50C each tilt from the direction parallel to the Y direction toward the X direction, and the magnetization directions of the free layers 54 of the plurality of MR elements 50D each tilt from the direction parallel to the Y direction toward the -X direction. As a result, compared with the state where the magnetic field component does not exist, the resistance values of the plurality of MR elements 50C constituting the resistance section R31 and the resistance values of the plurality of MR elements 50D constituting the resistance section R33 decrease, and the resistance values of the plurality of MR elements 50C constituting the resistance section R32 and the resistance values of the plurality of MR elements 50D constituting the resistance section R34 increase. As a result, the resistance values of the resistance sections R31 and R33 decrease, and the resistance values of the resistance sections R32 and R34 increase.

[0272] When the direction of the first magnetic field component Hz is in the -Z direction, the direction of the magnetic field component and the change in the resistance value of each of the resistance sections R31 to R34 are opposite to those in the case where the direction of the first magnetic field component Hz is in the Z direction described above.

[0273] The change amounts of the respective resistance values of the resistor portions R31 to R34 depend on the intensities of the magnetic field components received by the respective ones of the plurality of MR elements 50C and the plurality of MR elements 50D. When the intensity of the magnetic field component becomes larger, the respective resistance values of the resistor portions R31 to R34 change in the directions in which their increase amounts or their decrease amounts become larger, respectively. When the intensity of the magnetic field component becomes smaller, the respective resistance values of the resistor portions R31 to R34 change in the directions in which their increase amounts or their decrease amounts become smaller, respectively. The intensity of the magnetic field component depends on the intensity of the first magnetic field component Hz.

[0274] Thus, when the direction and intensity of the first magnetic field component Hz change, the respective resistance values of the resistor portions R31 to R34 change such that the respective resistance values of the resistor portions R32 and R34 decrease as the respective resistance values of the resistor portions R31 and R33 increase, or the respective resistance values of the resistor portions R32 and R34 increase as the respective resistance values of the resistor portions R31 and R33 decrease. Thereby, the potential at the connection point of the resistor portions R31 and R32, that is, the potential of the output port E3, and the potential at the connection point of the resistor portions R33 and R34, that is, the potential of the output port E32, change. The magnetic sensor 201 may also generate a signal corresponding to the potential of the output port E31 and a signal corresponding to the potential of the output port E32 as detection signals, respectively. Alternatively, the magnetic sensor 201 may generate a signal corresponding to the potential difference between the output ports E31 and E32 as a detection signal. In this case, the magnetic sensor 201 may further include a differential amplifier (differential detector) that outputs a signal corresponding to the potential difference between the output ports E31 and E32 as a detection signal.

[0275] The magnetic sensor system 200 may further include the ​ and ​ processor 2 shown in the first embodiment. The processor 2 may also be configured to receive one detection signal or two detection signals output from the magnetic sensor 201 and generate a detection value corresponding to the intensity of the first magnetic field component Hz or a detection value corresponding to the position of the magnetic field generation unit 202 (see ​ ).

[0276] Next, the plurality of magnetic yokes 90C and the plurality of magnetic yokes 90D will be described in detail with reference to ​ . ​ is a top view showing the main part of the magnetic sensor 201. ​ is showing ​ a cross-sectional view of a part of the cross-section at the position indicated by the line 43-43 in ​ is showing ​ a cross-sectional view of a part of the cross-section at the position indicated by the line 44-44 in

[0277] Hereinafter, any one of the plurality of magnetic yokes 90C and 90D is represented by the symbol 90. The configurations and shapes of the MR element 50 and the magnetic field generator 70, and the positional relationship between the MR element 50 and the magnetic field generator 70 are the same as those in the third embodiment.

[0278] Here, focusing on one MR element 50, the structure of the magnetic yoke 90 will be described. The two magnetic yokes 90 are arranged on both sides of the MR element 50 in a direction parallel to the X direction. The two magnetic yokes 90 are embedded in the insulating layer 32. The insulating layer 32 is interposed between the MR element 50 and the two magnetic yokes 90, and between the lower electrode 61 and the two magnetic yokes 90. Each of the two magnetic yokes 90 may include, in addition to the magnetic layer, a buffer layer interposed between the magnetic layer and the insulating layer 32 and a covering layer disposed on the magnetic layer. The buffer layer and the covering layer may be formed of a non-magnetic metal material, for example. In addition, the two magnetic yokes 90 are respectively arranged to straddle the side surface 50d of the MR element 50. A part of each of the two magnetic yokes 90 overlaps a part of the MR element 50 when viewed from the Z direction.

[0279] The two magnetic yokes 90 are arranged between two magnetic field generators 70 arranged at a predetermined interval in a direction parallel to the Y direction. The ferromagnetic layer 72a of the magnetic field generator 70 is arranged to overlap the two magnetic yokes 90 when viewed from the Y direction or the -Y direction.

[0280] The ferromagnetic layer 72a is arranged to straddle the magnetic yoke 90. A part of the ferromagnetic layer 72a overlaps a part of the magnetic yoke 90 when viewed from the Z direction. The insulating layer 33 is interposed between the ferromagnetic layer 72a and the magnetic yoke 90. A part of the buffer layer 71 of the magnetic field generator 70 is interposed between the ferromagnetic layer 72a and the insulating layer 33.

[0281] In the present embodiment, the upper electrode 62 is arranged above the MR element 50, the two magnetic field generators 70, the two magnetic yokes 90, and the insulating layer 32.

[0282] In addition, the structure of the magnetic field generator 70 in the present embodiment is not limited to ​ , ​ , ​ and ​ the examples shown. The magnetic sensor 201 of the present embodiment may also include a plurality of magnetic field generators having the same structure as any one of the first, second, third, or fourth embodiments, instead of the plurality of magnetic field generators 70 in the present embodiment. The other structures, operations, and effects in the present embodiment are the same as those in any one of the first to fourth embodiments.

[0283] In addition, the present invention is not limited to the above-described embodiments, and various modifications can be made. For example, the magnetic sensor of the present invention may also be a magnetic sensor including the first and second detection circuits 10 and 20 in the first embodiment and the magnetic sensor 201 of the fifth embodiment as the third detection circuit. In this magnetic sensor, the third detection circuit (magnetic sensor 201) may also be configured to detect a component in a direction parallel to the Z direction of the magnetic field to be detected. This magnetic sensor may also be a geomagnetic sensor for which the target magnetic field is geomagnetism.

[0284] Alternatively, the MR element 50 may also be formed by laminating in order from the lower electrode 61 side with a buffer layer 51, a free layer 54, a spacer layer 53, a magnetization fixing layer 52, and a cover layer 55.

[0285] In addition, the modification example of the magnetic sensor 1 of the third embodiment is not limited to the third embodiment, and may also be applied to embodiments other than the third embodiment.

[0286] In addition, in the case where a first magnetic field generating body including a ferromagnetic portion having magnetization in a first direction and a second magnetic field generating body including a ferromagnetic portion having magnetization in a second direction different from the first direction are formed in sequence, when irradiating a first initial magnetic field generating body that will later become the first magnetic field generating body with a laser, the second initial magnetic field generating body that will later become the second magnetic field generating body may also be irradiated with a laser. In this case, after fixing the direction of the magnetization of the ferromagnetic portion of the first magnetic field generating body, only the second initial magnetic field generating body is irradiated with a laser to fix the direction of the magnetization of the ferromagnetic portion of the second magnetic field generating body.

[0287] As described above, the magnetic sensor manufactured by the manufacturing method of the present invention includes: at least one magnetoresistive effect element including a magnetization fixing layer having magnetization with a component including a first direction, that is, magnetization with a fixed direction, and a free layer whose magnetization direction can change according to a magnetic field to be detected, that is, a target magnetic field; and at least one magnetic field generating body including a ferromagnetic portion and an antiferromagnetic portion and configured to generate a magnetic field applied to the at least one magnetoresistive effect element, the ferromagnetic portion including a ferromagnetic material and having magnetization with a component including a second direction different from the first direction, that is, magnetization with a fixed direction, and the antiferromagnetic portion including an antiferromagnetic material and being exchange-coupled with the ferromagnetic portion. The manufacturing method of the magnetic sensor of the present invention includes a step of forming at least one magnetoresistive effect element and a step of forming at least one magnetic field generating body. The step of forming at least one magnetic field generating body includes: a step of forming at least one initial magnetic field generating body including an initial ferromagnetic portion that will later become the ferromagnetic portion and the antiferromagnetic portion; and a step of using a laser and a first external magnetic field including a component in a first magnetic field direction to fix the direction of the magnetization of the initial ferromagnetic portion in such a manner that the initial ferromagnetic portion becomes the ferromagnetic portion. The first magnetic field direction may also be the same as the second direction.

[0288] In the method for manufacturing a magnetic sensor according to the present invention, the step of forming at least one magnetoresistive effect element may also include: a step of forming at least one initial magnetoresistive effect element including an initial magnetization fixing layer that will later become a magnetization fixing layer and a free layer; and a step of fixing the magnetization direction of the initial magnetization fixing layer by using a laser and a second external magnetic field including a component in a second magnetic field direction such that the initial magnetization fixing layer becomes a magnetization fixing layer. The second magnetic field direction may also be the same as the first direction. The step of fixing the magnetization direction of the initial magnetization fixing layer may also be performed before the step of fixing the magnetization direction of the initial ferromagnetic portion.

[0289] In addition, in the method for manufacturing a magnetic sensor according to the present invention, the magnetization fixing layer may also include: a first ferromagnetic layer including a ferromagnetic material; a second ferromagnetic layer including a ferromagnetic material; a nonmagnetic layer including a nonmagnetic metal material and interposed between the first ferromagnetic layer and the second ferromagnetic layer; and an antiferromagnetic layer including an antiferromagnetic material and in contact with the first ferromagnetic layer. The magnetization amount per unit area of the first ferromagnetic layer may also be less than or equal to the magnetization amount per unit area of the second ferromagnetic layer.

[0290] In addition, in the method for manufacturing a magnetic sensor according to the present invention, the magnetization fixing layer may also include: a ferromagnetic layer including a ferromagnetic material; and an antiferromagnetic layer including an antiferromagnetic material and in contact with the ferromagnetic layer. The antiferromagnetic portion and the antiferromagnetic layer may also contain at least one same element.

[0291] In addition, in the method for manufacturing a magnetic sensor according to the present invention, in the step of fixing the magnetization direction of the initial ferromagnetic portion, a laser may not be irradiated to at least one magnetoresistive effect element. Alternatively, in the step of fixing the magnetization direction of the initial ferromagnetic portion, a laser may be irradiated to at least one magnetoresistive effect element.

[0292] In addition, the method for manufacturing a magnetic sensor according to the present invention may further include a step of annealing the laminate including at least one magnetoresistive effect element and at least one magnetic field generating body by heating at a prescribed temperature after the step of fixing the magnetization direction of the initial ferromagnetic portion.

[0293] In addition, in the method for manufacturing a magnetic sensor according to the present invention, at least one magnetoresistive element may also be a first magnetoresistive element and a second magnetoresistive element. At least one magnetic field generating body may also be a first magnetic field generating body configured to generate a magnetic field applied to the first magnetoresistive element and a second magnetic field generating body configured to generate a magnetic field applied to the second magnetoresistive element. A group including the first magnetoresistive element and the first magnetic field generating body and a group including the second magnetoresistive element and the second magnetic field generating body may not have, interposed therebetween, a group of other magnetoresistive elements capable of detecting a magnetoresistive effect and other magnetic field generating bodies. The direction of magnetization of the ferromagnetic portion of the first magnetic field generating body and the direction of magnetization of the ferromagnetic portion of the second magnetic field generating body may also be different from each other. The step of forming at least one magnetic field generating body may also be a step of forming the first magnetic field generating body and the second magnetic field generating body. The step of forming at least one initial magnetic field generating body may also be a step of forming a first initial magnetic field generating body including a first initial ferromagnetic portion that will later become the ferromagnetic portion of the first magnetic field generating body and an antiferromagnetic portion of the first magnetic field generating body, and a second initial magnetic field generating body including a second initial ferromagnetic portion that will later become the ferromagnetic portion of the second magnetic field generating body and an antiferromagnetic portion of the second magnetic field generating body. The step of fixing the direction of magnetization of the initial ferromagnetic portion may also be a step of irradiating the first initial magnetic field generating body and the second initial magnetic field generating body with laser light in sequence and fixing the direction of magnetization of the first initial ferromagnetic portion and the direction of magnetization of the second initial ferromagnetic portion. When irradiating the second initial magnetic field generating body with laser light, the temperature of the ferromagnetic portion of the first initial magnetic field generating body may not rise above the blocking temperature.

[0294] In addition, in the method for manufacturing a magnetic sensor according to the present invention, at least one magnetoresistive element may also be a first magnetoresistive element and a second magnetoresistive element. At least one magnetic field generating body may also be a first magnetic field generating body configured to generate a magnetic field applied to the first magnetoresistive element and a second magnetic field generating body configured to generate a magnetic field applied to the second magnetoresistive element. The direction of magnetization of the ferromagnetic portion of the first magnetic field generating body and the direction of magnetization of the ferromagnetic portion of the second magnetic field generating body may also be the same direction. The step of forming at least one magnetic field generating body may also be a step of forming the first magnetic field generating body and the second magnetic field generating body. The step of forming at least one initial magnetic field generating body may also be a step of forming a first initial magnetic field generating body including a first initial ferromagnetic portion that will later become the ferromagnetic portion of the first magnetic field generating body and an antiferromagnetic portion of the first magnetic field generating body, and a second initial magnetic field generating body including a second initial ferromagnetic portion that will later become the ferromagnetic portion of the second magnetic field generating body and an antiferromagnetic portion of the second magnetic field generating body. The step of fixing the direction of magnetization of the initial ferromagnetic portion may also be a step of irradiating the first initial magnetic field generating body and the second initial magnetic field generating body with laser light simultaneously and fixing the direction of magnetization of the first initial ferromagnetic portion and the direction of magnetization of the second initial ferromagnetic portion.

[0295] In addition, in the method for manufacturing a magnetic sensor according to the present invention, at least one magnetoresistive element may also be a plurality of magnetoresistive elements. At least one magnetic field generating body may also be a plurality of magnetic field generating bodies. The step of forming at least one magnetic field generating body may also be a step of forming a plurality of magnetic field generating bodies. The step of forming at least one initial magnetic field generating body may also be a step of forming a plurality of initial magnetic field generating bodies each including an initial ferromagnetic portion and an antiferromagnetic portion that will later become ferromagnetic portions. The step of fixing the magnetization direction of the initial ferromagnetic portion may also be a step of sequentially irradiating one or more of the plurality of initial magnetic field generating bodies with laser light and fixing the magnetization directions of the initial ferromagnetic portions of the plurality of initial magnetic field generating bodies.

[0296] Based on the above description, it can be seen that various embodiments and modifications of the present invention can be implemented. Therefore, within the equivalent scope of the claims, the present invention can be implemented even in ways other than the above-described best mode.

Claims

1. A method for manufacturing a magnetic sensor, characterized in that, The magnetic sensor includes: At least one magnetoresistive effect element, which includes a magnetization fixing layer having a magnetization with a component in a first direction and a fixed direction, and a free layer whose magnetization direction can change according to an object magnetic field that is a magnetic field to be detected; And At least one magnetic field generating body, which includes a ferromagnetic part and an antiferromagnetic part, and is configured to generate a magnetic field applied to the at least one magnetoresistive effect element. The ferromagnetic part includes a ferromagnetic material and has a magnetization with a component in a second direction different from the first direction and a fixed direction. The antiferromagnetic part includes an antiferromagnetic material and is exchange-coupled with the ferromagnetic part, The manufacturing method includes: A step of forming the at least one magnetoresistive effect element; and A step of forming the at least one magnetic field generating body, The step of forming the at least one magnetic field generating body includes: A step of forming at least one initial magnetic field generating body including an initial ferromagnetic part that will later become the ferromagnetic part and the antiferromagnetic part; and A step of using a laser and a first external magnetic field including a component in a first magnetic field direction to fix the magnetization direction of the initial ferromagnetic part so that the initial ferromagnetic part becomes the ferromagnetic part.

2. The method for manufacturing a magnetic sensor according to claim 1, characterized in that, The step of forming the at least one magnetoresistive effect element includes: A step of forming at least one initial magnetoresistive effect element including an initial magnetization fixing layer that will later become the magnetization fixing layer and the free layer; and A step of using a laser and a second external magnetic field including a component in a second magnetic field direction to fix the magnetization direction of the initial magnetization fixing layer so that the initial magnetization fixing layer becomes the magnetization fixing layer.

3. The method for manufacturing a magnetic sensor according to claim 2, characterized in that, The step of fixing the magnetization direction of the initial magnetization fixing layer is performed before the step of fixing the magnetization direction of the initial ferromagnetic part.

4. The method for manufacturing a magnetic sensor according to claim 1, characterized in that, The magnetization fixing layer includes: a first ferromagnetic layer containing a ferromagnetic material; a second ferromagnetic layer containing a ferromagnetic material; a non-magnetic layer containing a non-magnetic metal material and interposed between the first ferromagnetic layer and the second ferromagnetic layer; and an antiferromagnetic layer containing an antiferromagnetic material and in contact with the first ferromagnetic layer.

5. The method for manufacturing a magnetic sensor according to claim 4, characterized in that, The magnetization per unit area of the first ferromagnetic layer is less than or equal to the magnetization per unit area of the second ferromagnetic layer.

6. The method for manufacturing a magnetic sensor according to claim 1, characterized in that, The magnetization fixing layer includes: a ferromagnetic layer containing a ferromagnetic material; and an antiferromagnetic layer containing an antiferromagnetic material and in contact with the ferromagnetic layer, The antiferromagnetic part and the antiferromagnetic layer contain at least one same element.

7. The method for manufacturing a magnetic sensor according to claim 1, characterized in that, In the process of fixing the magnetization direction of the initial ferromagnetic portion, the laser is not irradiated to the at least one magnetoresistive effect element.

8. The method for manufacturing a magnetic sensor according to claim 1, wherein: In the process of fixing the magnetization direction of the initial ferromagnetic portion, the laser is irradiated to the at least one magnetoresistive effect element.

9. The method for manufacturing a magnetic sensor according to claim 1, wherein: It further includes: after the process of fixing the magnetization direction of the initial ferromagnetic portion, an annealing process of heating the laminate including the at least one magnetoresistive effect element and the at least one magnetic field generating body at a prescribed temperature.

10. The method for manufacturing a magnetic sensor according to claim 1, wherein: The at least one magnetoresistive effect element is a first magnetoresistive effect element and a second magnetoresistive effect element, The at least one magnetic field generating body is a first magnetic field generating body configured to generate a magnetic field applied to the first magnetoresistive effect element and a second magnetic field generating body configured to generate a magnetic field applied to the second magnetoresistive effect element, Between the group of the first magnetoresistive effect element and the first magnetic field generating body and the group of the second magnetoresistive effect element and the second magnetic field generating body, there is no group of other magnetoresistive effect elements capable of detecting the magnetoresistive effect and other magnetic field generating bodies, The magnetization direction of the ferromagnetic portion of the first magnetic field generating body and the magnetization direction of the ferromagnetic portion of the second magnetic field generating body are different from each other.

11. The method for manufacturing a magnetic sensor according to claim 10, wherein: The process of forming the at least one magnetic field generating body is a process of forming the first magnetic field generating body and the second magnetic field generating body, The process of forming the at least one initial magnetic field generating body is a process of forming a first initial magnetic field generating body including a first initial ferromagnetic portion that becomes the ferromagnetic portion of the first magnetic field generating body later and an antiferromagnetic portion of the first magnetic field generating body, and a second initial magnetic field generating body including a second initial ferromagnetic portion that becomes the ferromagnetic portion of the second magnetic field generating body later and an antiferromagnetic portion of the second magnetic field generating body, The process of fixing the magnetization direction of the initial ferromagnetic portion is a process of sequentially irradiating the first initial magnetic field generating body and the second initial magnetic field generating body with the laser and fixing the magnetization direction of the first initial ferromagnetic portion and the magnetization direction of the second initial ferromagnetic portion, When irradiating the second initial magnetic field generating body with the laser, the temperature of the ferromagnetic portion of the first initial magnetic field generating body does not rise above the blocking temperature.

12. The method for manufacturing a magnetic sensor according to claim 1, wherein: The at least one magnetoresistive effect element is a first magnetoresistive effect element and a second magnetoresistive effect element, The at least one magnetic field generating body is a first magnetic field generating body configured to generate a magnetic field applied to the first magnetoresistive effect element and a second magnetic field generating body configured to generate a magnetic field applied to the second magnetoresistive effect element, The magnetization directions of the ferromagnetic portions of the first magnetic field generating body and the ferromagnetic portions of the second magnetic field generating body are in the same direction. The step of forming the at least one magnetic field generating body is the step of forming the first magnetic field generating body and the second magnetic field generating body. The step of forming the at least one initial magnetic field generating body is the step of forming a first initial magnetic field generating body including a first initial ferromagnetic portion that later becomes the ferromagnetic portion of the first magnetic field generating body and an antiferromagnetic portion of the first magnetic field generating body, and a second initial magnetic field generating body including a second initial ferromagnetic portion that later becomes the ferromagnetic portion of the second magnetic field generating body and an antiferromagnetic portion of the second magnetic field generating body. The step of fixing the magnetization direction of the initial ferromagnetic portion is the step of simultaneously irradiating the first initial magnetic field generating body and the second initial magnetic field generating body with the laser and fixing the magnetization directions of the first initial ferromagnetic portion and the second initial ferromagnetic portion.

13. The method for manufacturing a magnetic sensor according to claim 1, wherein: The at least one magnetoresistive effect element is a plurality of magnetoresistive effect elements. The at least one magnetic field generating body is a plurality of magnetic field generating bodies. The step of forming the at least one magnetic field generating body is the step of forming the plurality of magnetic field generating bodies. The step of forming the at least one initial magnetic field generating body is the step of forming a plurality of initial magnetic field generating bodies each including an initial ferromagnetic portion that later becomes the ferromagnetic portion and an antiferromagnetic portion. The step of fixing the magnetization direction of the initial ferromagnetic portion is the step of sequentially irradiating one or more of the plurality of initial magnetic field generating bodies with the laser and fixing the magnetization directions of the initial ferromagnetic portions of the plurality of initial magnetic field generating bodies.

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