Magnetic sensor

Abstract

The invention relates to a magnetic sensor. This magnetic sensor is provided with: at least one MR element; a ferromagnetic layer configured to overlap the at least one MR element when viewed from the first direction; insulating layers disposed on both sides of the at least one MR element in the second direction; a base layer disposed on the at least one MR element, the ferromagnetic layer, and the insulating layer; and an antiferromagnetic layer disposed on the base layer. The antiferromagnetic layer includes an antiferromagnetic portion opposed to the ferromagnetic layer via the base layer, and a non-opposed portion opposed to the at least one MR element and the insulating layer but not to the ferromagnetic layer via the base layer.

Description

Technical Field

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

[0002] In recent years, magnetic sensors have been used in various applications. As a magnetic sensor, a magnetic sensor using a spin valve type magnetoresistive effect element provided on a substrate is known. The spin valve type magnetoresistive effect element has: a magnetization fixed layer whose magnetization direction is fixed; a free layer whose magnetization direction 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] Among magnetic sensors, there are magnetic sensors having a mechanism for applying a bias magnetic field to a magnetoresistive effect element. The bias magnetic field is used, for example, to make the magnetoresistive effect element linearly respond to the intensity change of the object magnetic field. In addition, in a magnetic sensor using a spin valve type magnetoresistive effect element, the bias magnetic field is also used to single-domainize the free layer and make the magnetization direction of the free layer face a certain direction when there is no object magnetic field.

[0004] As a mechanism for generating a bias magnetic field, a magnetic field generating body formed by laminating an antiferromagnetic layer and a ferromagnetic layer is known. Japanese Unexamined Patent Application Publication No. 2015-125020 and Chinese Patent Application Publication No. 105988092A disclose a magnetic sensor including a magnetoresistive effect element and two magnetic field generating bodies configured to sandwich the magnetoresistive effect element.

[0005] In order to increase the intensity of the bias magnetic field applied to the magnetoresistive effect element, it is preferable to reduce the interval between the magnetoresistive effect element and the magnetic field generating body. As a method of forming the magnetic field generating body in such a manner that the interval between the magnetoresistive effect element and the magnetic field generating body becomes small, for example, it is considered to form a thin insulating film on the side surface of the magnetoresistive effect element and form the magnetic field generating body so as to be adjacent to the side surface of the magnetoresistive effect element via the insulating film.

[0006] Generally, the side surface of the magnetoresistive effect element is tapered. Therefore, when the magnetic field generating body is formed by the above method, the magnetic field generating body is formed to rise to the side surface of the magnetoresistive effect element. In this case, the film thickness of the portion of each layer constituting the magnetic field generating body that rises to the side surface of the magnetoresistive effect element becomes smaller as it approaches the magnetoresistive effect element. As a result, there is a problem that each layer constituting the magnetic field generating body cannot be effectively used and the desired characteristics cannot be achieved. Summary of the Invention

[0007] An object of the present invention is to provide a magnetic sensor that can effectively use a functional layer formed near a magnetoresistive effect element and having a specified function and achieve a desired function.

[0008] The magnetic sensor of the present invention includes: at least one magnetoresistive element including a plurality of stacked magnetic films; a first ferromagnetic layer including a ferromagnetic material and configured to overlap with at least one magnetoresistive element when viewed from a first direction orthogonal to the stacking direction of the plurality of magnetic films; an insulating layer including an insulating material and disposed on both sides of at least one magnetoresistive element in a second direction orthogonal to the stacking direction and the first direction, respectively; a base layer disposed above at least one magnetoresistive element, the first ferromagnetic layer, and the insulating layer; and an antiferromagnetic layer disposed above the base layer. The antiferromagnetic layer includes: a first antiferromagnetic portion facing the first ferromagnetic layer via the base layer, and a non-facing portion facing at least one magnetoresistive element and the insulating layer via the base layer but not facing the first ferromagnetic layer.

[0009] In the magnetic sensor of the present invention, the base layer is disposed above at least one magnetoresistive element, the first ferromagnetic layer, and the insulating layer, and the antiferromagnetic layer is disposed above the base layer. The antiferromagnetic layer includes: a first antiferromagnetic portion facing the first ferromagnetic layer via the base layer, and a non-facing portion facing at least one magnetoresistive element and the insulating layer via the base layer but not facing the first ferromagnetic layer. Thus, according to the present invention, the antiferromagnetic layer as a functional layer can be effectively used to achieve a desired function.

[0010] Other objects, features, and advantages of the present invention will become fully apparent from the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 is a perspective view of a magnetic sensor device including the magnetic sensor according to the first embodiment of the present invention.

[0012] Figure 2 is a functional block diagram showing the structure of the magnetic sensor device according to the first embodiment of the present invention.

[0013] Figure 3 is a circuit diagram showing the circuit structure of the magnetic sensor according to the first embodiment of the present invention.

[0014] Figure 4 is a perspective view of a part of the first detection circuit according to the first embodiment of the present invention.

[0015] Figure 5 is a top view of a part of the first detection circuit according to the first embodiment of the present invention.

[0016] Figure 6 is a top view of a part of the second detection circuit according to the first embodiment of the present invention.

[0017] Figure 7This is a top view of the main part of the magnetic sensor according to the first embodiment of the present invention.

[0018] Figure 8 This is a top view of the magnetoresistive effect element, magnetic field generating body, and insulating layer in the first embodiment of the present invention.

[0019] Figure 9 This is a view showing Figure 7 a partial cross-sectional view of the position indicated by line 9-9 in

[0020] Figure 10 This is a view showing Figure 7 a partial cross-sectional view of the position indicated by line 10-10 in

[0021] Figure 11 This is a cross-sectional view showing the formation method of the magnetic field generating body of the comparative example.

[0022] Figure 12A This is a cross-sectional view showing the formation method of the magnetic field generating body in the first embodiment of the present invention.

[0023] Figure 12B This is a cross-sectional view showing the formation method of the magnetic field generating body in the first embodiment of the present invention.

[0024] Figure 13 This is a top view of the main part of the first modified example of the magnetic sensor according to the first embodiment of the present invention.

[0025] Figure 14 This is a top view of the main part of the second modified example of the magnetic sensor according to the first embodiment of the present invention.

[0026] Figure 15 This is a top view of the main part of the third modified example of the magnetic sensor according to the first embodiment of the present invention.

[0027] Figure 16 This is a cross-sectional view of the main part of the fourth modified example of the magnetic sensor according to the first embodiment of the present invention.

[0028] Figure 17 This is a cross-sectional view of the main part of the fifth modified example of the magnetic sensor according to the first embodiment of the present invention.

[0029] Figure 18 This is a cross-sectional view of the main part of the sixth modified example of the magnetic sensor according to the first embodiment of the present invention.

[0030] Figure 19 This is a cross-sectional view of the main part of the seventh modified example of the magnetic sensor according to the first embodiment of the present invention.

[0031] Figure 20 It is a cross-sectional view showing the main part of the eighth modification of the magnetic sensor according to the first embodiment of the present invention.

[0032] Figure 21 It is a perspective view showing a magnetic sensor system including the magnetic sensor according to the second embodiment of the present invention.

[0033] Figure 22 It is a circuit diagram showing the circuit structure of the magnetic sensor according to the second embodiment of the present invention.

[0034] Figure 23 It is a perspective view showing a part of the magnetic sensor according to the second embodiment of the present invention.

[0035] Figure 24 It is a top view showing a part of the magnetic sensor according to the second embodiment of the present invention.

[0036] Figure 25 It is a side view showing a part of the magnetic sensor according to the second embodiment of the present invention.

[0037] Figure 26 It is a top view showing the main part of the magnetic sensor according to the second embodiment of the present invention.

[0038] Figure 27 It is showing Figure 26 A cross-sectional view of a part of the cross-section at the position indicated by line 27-27 in

[0039] Figure 28 It is showing Figure 26 A cross-sectional view of a part of the cross-section at the position indicated by line 28-28 in

[0040] Figure 29 It is a top view showing the main part of the magnetic sensor according to the third embodiment of the present invention.

[0041] Figure 30 It is showing Figure 29 A cross-sectional view of a part of the cross-section at the position indicated by line 30-30 in

[0042] Figure 31 It is showing Figure 29 A cross-sectional view of a part of the cross-section at the position indicated by line 31-31 in Detailed Embodiments

[0043] [First Embodiment]

[0044] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. First, refer to Figure 1 and Figure 2, the structure of a 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 showing the magnetic sensor device of the present embodiment. Figure 2 It is a functional block diagram showing the structure of the magnetic sensor device of the present embodiment.

[0045] The magnetic sensor device 100 of the present embodiment includes the magnetic sensor 1 of the present embodiment and a processor 2. The magnetic sensor 1 is configured to detect a magnetic field to be detected by the magnetic sensor 1, that is, an object magnetic field, and generate at least one detection signal. The magnetic sensor 1 can be a geomagnetic sensor that detects geomagnetism, a magnetic sensor for an angle sensor or a magnetic encoder that detects a rotating magnetic field, or a magnetic sensor for a current sensor that detects a magnetic field generated by a detected current.

[0046] The processor 2 is configured to generate at least one detection value having a corresponding relationship 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).

[0047] The magnetic sensor 1 and the processor 2 each have a form of a rectangular parallelepiped-shaped chip. 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 by, for example, an adhesive.

[0048] Here, as Figure 1 shown, the X direction, the Y direction, and the Z direction are defined. The X direction, the Y direction, and the Z direction are orthogonal to each other. In the present embodiment, the direction perpendicular to the upper surface 1a of the magnetic sensor 1 and 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.

[0049] Hereinafter, a position in front of the reference position in the Z direction will be referred to as "above", and a position on the opposite side of the "above" with respect to the reference position will be referred to as "below". In addition, regarding the constituent elements of the magnetic sensor 1, the surface located at one end in the Z direction will be referred to as the "upper surface", and the surface located at one end in the -Z direction will be referred to as the "lower surface". In addition, the expression "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.

[0050] 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.

[0051] 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.

[0052] 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 elements. Hereinafter, the magnetoresistive element will be referred to as an MR element.

[0053] The first detection circuit 10 detects a component of the target magnetic field in a direction parallel to the X direction and generates at least one first detection signal having a corresponding relationship with the component. The second detection circuit 20 detects a component of the target magnetic field in a direction parallel to the Y direction and generates at least one second detection signal having a corresponding relationship with the component.

[0054] Next, with reference to Figure 3 the circuit structure of the magnetic sensor 1 will be described. Figure 3 is a circuit diagram showing the circuit structure of the magnetic sensor 1.

[0055] The first detection circuit 10 includes four resistor portions R11, R12, R13, R14, a power supply port V1, a ground port G1, and two output ports E11, E12. The resistor portion R11 is provided between the power supply port V1 and the output port E11. The resistor portion R12 is provided between the output port E11 and the ground port G1. The resistor portion R13 is provided between the output port E22 and the ground port G2. The resistor portion R14 is provided 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.

[0056] The second detection circuit 20 includes four resistor portions R21, R22, R23, R24, a power supply port V2, a ground port G2, and two output ports E21, E22. The resistor portion R21 is provided between the power supply port V2 and the output port E21. The resistor portion R22 is provided between the output port E21 and the ground port G2. The resistor portion R23 is provided between the output port E22 and the ground port G2. The resistor portion R24 is provided 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.

[0057] Next, with reference to Figures 4 to 6The structures of the first and second detection circuits 10 and 20 are described respectively. Figure 4 It is a perspective view showing a part of the first detection circuit 10. Figure 5 It is a top view showing a part of the first detection circuit 10. Figure 6 It is a top view showing a part of the second detection circuit 20.

[0058] 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 provided 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.

[0059] The resistor parts R11 to R14 each further include a plurality of lower electrodes 61 and a plurality of upper electrodes 62. As Figure 4 and Figure 5 shown, the plurality of MR elements 50A each have a long shape in a direction parallel to the Y direction. The plurality of lower electrodes 61 each electrically connect two adjacent MR elements 50A in a direction parallel to the X direction. The plurality of upper electrodes 62 are respectively disposed above the two lower electrodes 61 and electrically connect the adjacent two MR elements 50A. Thus, the plurality of MR elements 50A arranged in a row in the direction parallel to the X direction are connected in series.

[0060] The resistor parts R11 to R14 each further include a plurality of connection electrodes (not shown). In each of the resistor parts 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 the groups of the plurality of MR elements 50A arranged in a row are connected in series. With such a structure, the resistor parts R11 to R14 each include a plurality of lower electrodes 61, a plurality of upper electrodes 62, and a plurality of MR elements 50A connected in series by the plurality of connection electrodes.

[0061] 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 resistor parts R21 to R24. As Figure 6 shown, in each of the resistor parts R21 to R24, the plurality of MR elements 50B each have a long shape in a direction parallel to the X direction. If the plurality of MR elements 50A, the X direction, and the Y direction in the above description of the connection relationship of the plurality of MR elements 50A 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.

[0062] The resistor sections R11 to R14 each further include a plurality of magnetic field generators 70A. The plurality of magnetic field generators 70A each include pairs of a 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 with one MR element 50A interposed therebetween. The two magnetic field generators 70A are configured to apply a bias magnetic field to one MR element 50A located therebetween. This bias magnetic field may also include a component in the direction parallel to the Y direction as a main component.

[0063] The resistor sections R21 to R24 each further include a plurality of magnetic field generators 70B. The plurality of magnetic field generators 70B each include pairs of a 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 with one MR element 50B interposed therebetween. The two magnetic field generators 70B are configured to apply a bias magnetic field to one MR element 50B located therebetween. This bias magnetic field may also include a component in the direction parallel to the X direction as a main component.

[0064] As Figure 4 shown, the plurality of magnetic field generators 70A may also be respectively clamped between the lower electrode 61 and the upper electrode 62. Although not shown, the plurality of magnetic field generators 70B may also be respectively clamped between the lower electrode 61 and the upper electrode 62.

[0065] In the present embodiment, the plurality of MR elements 50A and the plurality of MR elements 50B are each a spin valve type MR element. This spin valve type MR element includes: a magnetization fixed layer with a fixed magnetization direction, a free layer whose magnetization direction can change according to the direction of the target magnetic field, and a spacer layer disposed between the magnetization fixed 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 a TMR element, the spacer layer is a tunnel barrier layer. In a GMR element, the spacer layer is a non-magnetic conductive layer. In the spin valve type MR element, the resistance value changes according to the angle formed between the magnetization direction of the free layer and the magnetization direction of the magnetization fixed 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 such that the direction of the easy magnetization axis becomes orthogonal to the magnetization direction of the magnetization fixed layer.

[0066] The MR element of the spin valve type may also include an antiferromagnetic layer. The antiferromagnetic layer is composed of an antiferromagnetic material, generates an exchange coupling with the magnetization fixing layer, and fixes the magnetization direction of the magnetization fixing layer. In addition, the magnetization fixing layer may also be a so-called self-pinned type fixing layer (Synthetic Ferri Pinned layer, SFP layer). The self-pinned type fixing layer has a stacked ferrite structure formed by laminating a ferromagnetic layer, a nonmagnetic intermediate layer, and a ferromagnetic layer, and is formed by antiferromagnetically coupling two ferromagnetic layers. When the magnetization fixing layer is a self-pinned type fixing layer, the antiferromagnetic layer may be omitted.

[0067] Next, refer to Figure 3 to explain the magnetization direction of the magnetization fixing layer and the direction of the bias magnetic field. In Figure 3 , a plurality of solid arrows respectively drawn so as to overlap with the resistance portions R11 to R14, R21 to R24 indicate the magnetization direction of the magnetization fixing layer in each of the resistance portions R11 to R14, R21 to R24. In Figure 3 the example shown, the direction of the main component of the magnetization of the magnetization fixing layer in each of the resistance portions 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 portions R12 and R14 is the -X direction. Each of the free layers in the resistance portions R11 to R14 has shape anisotropy in which the direction of the easy magnetization axis is parallel to the Y direction.

[0068] The direction of the main component of the magnetization of the magnetization fixing layer in each of the resistance portions 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 portions R22 and R24 is the -Y direction. Each of the free layers in the resistance portions R21 to R24 has shape anisotropy in which the direction of the easy magnetization axis is parallel to the X direction.

[0069] In Figure 3 , the arrows marked with symbols M11, M12, M13, and M14 respectively indicate the direction of the main component of the bias magnetic field generated by the plurality of magnetic field generators 70A in the resistance portions R11, R12, R13, and R14. The direction of the main component of the bias magnetic field in the resistance portions R11 and R12 may also be the Y direction. The direction of the main component of the bias magnetic field in the resistance portions R13 and R14 may also be the -Y direction.

[0070] In Figure 3Among them, multiple hollow arrows depicted in a manner overlapping with the resistance portions R11 to R14 respectively represent the magnetization directions of the free layers in each of the resistance portions 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 layer in each of the resistance portions 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 portions R11 and R12. The direction of the main component of the magnetization of the free layer in each of the resistance portions 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 portions R13 and R14.

[0071] In Figure 3 Among them, the arrows marked with symbols M21, M22, M23, and M24 respectively represent the directions of the main components of the bias magnetic fields generated by the multiple magnetic field generating bodies 70B in the resistance portions R21, R22, R23, and R24. The direction of the main component of the bias magnetic field in the resistance portions R21 and R22 may be the X direction. The direction of the main component of the bias magnetic field in the resistance portions R23 and R24 may be the -X direction.

[0072] In Figure 3 Among them, multiple hollow arrows depicted in a manner overlapping with the resistance portions R21 to R24 respectively represent the magnetization directions of the free layers in each of the resistance portions R21 to R24 when no object magnetic field is applied to the magnetic sensor 1. The direction of the main component of the magnetization of the free layer in each of the resistance portions 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 portions R21 and R22. The direction of the main component of the magnetization of the free layer in each of the resistance portions 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 portions R23 and R24.

[0073] In addition, the magnetization direction may be consistent 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 be consistent 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, it is assumed that the magnetization direction is consistent with the direction of the main component of the magnetization, and it is assumed that the direction of the bias magnetic field is consistent with the direction of the main component of the bias magnetic field.

[0074] Next, referring to Figure 3The functions of the first and second detection circuits 10 and 20 will be described. In the first detection circuit 10, the potential at the connection point of the resistor sections R11 and R12, i.e., the potential of the output port E11, and the potential at the connection point of the resistor sections R13 and R14, i.e., the potential of the output port E12, vary according to the intensity of the component of the target magnetic field in the direction parallel to the X direction. The first detection circuit 10 can 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 the first detection signals, respectively. Alternatively, the first detection circuit 10 can also generate a signal corresponding to the potential difference between the output ports E11 and E12 as the first detection signal. In this case, the first detection circuit 10 can also further include a differential amplifier (differential detector) that outputs a signal corresponding to the potential difference between the output ports E11 and E12 as the first detection signal.

[0075] 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 can 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 can also 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 can also 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.

[0076] Next, with reference to Figures 7 to 10 The structures of the multiple MR elements 50A, the multiple MR elements 50B, the multiple magnetic field generators 70A, and the multiple magnetic field generators 70B will be described in detail. Figure 7 It is a top view showing the main part of the magnetic sensor 1. Figure 8 It is a top view showing the MR element, the magnetic field generator, and the insulating layer. Figure 9 It shows Figure 7 A partial cross-sectional view of the position indicated by the line 9-9 in Figure 10 It shows Figure 7 A partial cross-sectional view of the position indicated by the line 10-10 in

[0077] Here, as Figures 7 to 10As shown, a first direction D1 and a second direction D2 that are orthogonal to each other and orthogonal to the Z direction are respectively defined. In the first detection circuit 10, the first direction D1 is a direction parallel to the Y direction, and the second direction D2 is a direction parallel to the X direction. In the second detection circuit 20, the first direction D1 is a direction parallel to the X direction, and the second direction D2 is a direction parallel to the Y direction.

[0078] Hereinafter, any one of the plurality of MR elements 50A and the plurality of MR elements 50B is represented by the symbol 50, and any one of 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, the magnetic sensor 1 includes a plurality of MR elements 50 as at least one MR element 50.

[0079] 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 a direction parallel to the Z direction. The plurality of magnetic films include the magnetization fixing layer 52 and the free layer 54 described above. Each of the plurality of MR elements 50 further includes the gap layer 53, the buffer layer 51, and the cover layer 55 described above. As Figure 9 and Figure 10 shown, the buffer layer 51, the magnetization fixing layer 52, the gap layer 53, the free layer 54, and the cover layer 55 are stacked in this order along the Z direction. The buffer layer 51 and the cover layer 55 are each formed of a non-magnetic metal material such as Ru, Ta, Cu, and Cr, for example.

[0080] 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 stacking direction of the plurality of magnetic films (the direction parallel to the Z direction).

[0081] The magnetic sensor 1 further includes: at least one ferromagnetic layer 72 made of a ferromagnetic material; and an insulating layer 32 made of an insulating material such as Al2O3 and SiO2. The at least one ferromagnetic layer 72 is disposed to overlap the MR element 50 when viewed from the first direction D1. In the present embodiment, in particular, the at least one ferromagnetic layer 72 is disposed to overlap the entire free layer 54 when viewed from the first direction D1.

[0082] In addition, at least one ferromagnetic layer 72 is configured to rise to the side surface 50c of the MR element 50. When viewed from the Z direction, a part of at least one ferromagnetic layer 72 overlaps with a part of the MR element 50. The insulating layer 32 is disposed on both sides of the MR element 50 in the second direction D2.

[0083] In the present embodiment, in particular, the MR element 50 is disposed between two ferromagnetic layers 72 that are disposed at a predetermined interval in the first direction D1. The insulating layer 32 is disposed around the MR element 50 and the two ferromagnetic layers 72.

[0084] The ferromagnetic layer 72 is formed of a ferromagnetic material containing one or more elements of Co, Fe, and Ni. Examples of such a ferromagnetic material include CoFe, CoFeB, and CoNiFe. The ferromagnetic layer 72 may also be composed of a laminate of multiple layers and a laminate in which two adjacent layers are made of different ferromagnetic materials. Examples of such a ferromagnetic layer 72 include a laminate of a Co layer, a CoFe layer, and a Co layer, Co 70 Fe 30 layer, Co 30 Fe 70 layer, Co 70 Fe 30 layer laminate. In addition, Co 70 Fe 30 represents an alloy composed of 70 atomic% Co and 30 atomic% Fe, Co 30 Fe 70 represents an alloy composed of 30 atomic% Co and 70 atomic% Fe.

[0085] The magnetic sensor 1 further includes two buffer layers 71 respectively disposed on the lower surface side (-Z direction side) of the plurality of two ferromagnetic layers 72. The two buffer layers 71 are formed of a non-magnetic metal material such as Ru, Ta, Cu, and Cr, for example.

[0086] The magnetic sensor 1 further includes: a base layer 73 disposed above the MR element 50, the two ferromagnetic layers 72, and the insulating layer 32; an antiferromagnetic layer 74 disposed above the base layer 73; and a cover layer 75 disposed above the antiferromagnetic layer 74. The antiferromagnetic layer 74 includes two antiferromagnetic portions 74a facing the two ferromagnetic layers 72 via the base layer 73, and a non-facing portion 74b facing the MR element 50 and the insulating layer 32 via the base layer 73 but not facing the two ferromagnetic layers 72. The two antiferromagnetic portions 74a are connected to each other by the non-facing portion 74b.

[0087] The base layer 73 includes two intervening portions 73a interposed between two ferromagnetic layers 72 and two antiferromagnetic portions 74a. The cover layer 75 includes two protective portions 75a disposed above the two antiferromagnetic portions 74a.

[0088] The base layer 73 is formed of a metallic material. In the present embodiment, in particular, the base layer 73 is formed of a ferromagnetic metallic material. In the case where the base layer 73 is formed of a ferromagnetic metallic material, the base layer 73 may also be formed of the same material as the ferromagnetic layer 72. Further, at least the intervening portion 73a of the base layer 73 may have magnetism. The portion of the base layer 73 interposed between the MR element 50 and the insulating layer 32 and the antiferromagnetic layer 74 may or may not have magnetism. The antiferromagnetic layer 74 is formed of an antiferromagnetic material such as IrMn or PtMn, for example. The cover layer 75 is formed of a nonmagnetic metallic material such as Ru, Ta, Cu, and Cr, for example.

[0089] The buffer layer 71 and the ferromagnetic layer 72 constitute a first laminate 701. The base layer 73, the antiferromagnetic layer 74, and the cover layer 75 constitute a second laminate 702. The MR element 50 is disposed between the two first laminates 701. The second laminate 702 is disposed above the MR element 50, the insulating layer 32, and the two first laminates 701.

[0090] The second laminate 702 includes two laminated portions 702a disposed above the two first laminates 701. The two laminated portions 702a each include an intervening portion 73a, an antiferromagnetic portion 74a, and a protective portion 75a.

[0091] The ferromagnetic layer 72 has magnetization as a whole of the ferromagnetic layer 72. The magnetization as a whole of the ferromagnetic layer 72 is obtained by volume-averaging the vector sum of the magnetic moments per unit of atoms, crystal lattices, etc. in the whole of the ferromagnetic layer 72. Hereinafter, the magnetization of the ferromagnetic layer 72 as a whole will be simply referred to as the magnetization of the ferromagnetic layer 72. In the laminate formed of the first laminate 701 and the laminated portion 702a disposed above the first laminate 701, the antiferromagnetic portion 74a is exchange-coupled with the ferromagnetic layer 72. Thereby, the magnetization direction of the ferromagnetic layer 72 is defined. The ferromagnetic layer 72 and the antiferromagnetic portion 74a may also constitute a magnetic field generating body 70 that generates a bias magnetic field applied to the MR element 50 based on the magnetization of the ferromagnetic layer 72. The magnetic field generating body 70 configured in this way has high resistance to an interfering magnetic field.

[0092] The ferromagnetic layer 72 is part of the first laminate 701, and the antiferromagnetic part 74a is part of the laminated part 702a. Therefore, it can also be said that the first laminate 701 and the laminated part 702a constitute the magnetic field generating body 70. The magnetic field generating body 70 includes a buffer layer 71, a ferromagnetic layer 72, an intervening part 73a, an antiferromagnetic part 74a, and a protective part 75a. The MR element 50 is disposed between two magnetic field generating bodies 70. The two magnetic field generating bodies 70 cooperatively apply a bias magnetic field to the MR element 50. The magnetization directions of the ferromagnetic layers 72 of one of the two magnetic field generating bodies 70 and the magnetization directions of the ferromagnetic layers 72 of the other of the two magnetic field generating bodies 70 may also be the same. In this case, the directions of the bias magnetic fields generated by one of the two magnetic field generating bodies 70 and the directions of the bias magnetic fields generated by the other of the two magnetic field generating bodies 70 become the same direction.

[0093] In the case where the base layer 73 is formed of the same material as the ferromagnetic layer 72, the ferromagnetic layer 72 and the intervening part 73a actually constitute a single ferromagnetic layer. The antiferromagnetic part 74a is in contact with the upper surface of the single ferromagnetic layer and is exchange-coupled with the single ferromagnetic layer.

[0094] The maximum size of the ferromagnetic layer 72 in the stacking direction (the direction parallel to the Z direction) of the plurality of magnetic films may also be larger than the maximum size of the base layer 73 in the stacking direction. In addition, the maximum size of the free layer 54 in the stacking direction may also be larger than the maximum size of the base layer 73 in the stacking direction.

[0095] The upper surface 50a of the MR element 50 faces the non-opposing part 74b of the antiferromagnetic layer 74. The interval between the non-opposing part 74b and the lower surface 50b of the MR element 50 may also be larger than the interval between the upper surface 50a and the lower surface 50b. The interval between the antiferromagnetic part 74a of the antiferromagnetic layer 74 and the upper surface of the lower electrode 61 may be the same as the interval between the non-opposing part 74b and the lower surface 50b, or may be different from the interval between the non-opposing part 74b and the lower surface 50b. In the latter case, the maximum interval between the antiferromagnetic part 74a and the upper surface of the lower electrode 61 may be larger than the interval between the non-opposing part 74b and the lower surface 50b, or may be smaller than the interval between the non-opposing part 74b and the lower surface 50b.

[0096] The ferromagnetic layer 72 has a side surface 72a facing the side surface 50c of the MR element 50. The side surface 72a includes an inclined portion 72a1 that faces the free layer 54 of the MR element 50 and is inclined with respect to the stacking direction (the direction parallel to the Z direction) of the plurality of magnetic films. The angle formed by the inclined portion 72a1 and the stacking direction may also be in the range of 20° or more and 90° or less.

[0097] The magnetic sensor 1 further includes an insulating material and is interposed between the substrates 30 (refer toFigures 4 to 6 ) and the insulating layer 31 between the lower electrode 61, and the insulating layer 33 made of an insulating material and interposed between the MR element 50 and the two first stacked bodies 701. The insulating layers 31 and 33 are formed of an insulating material such as Al2O3 or SiO2, for example.

[0098] The upper surface of the second stacked body 702, that is, the upper surface of the covering layer 75, is in contact with the upper electrode 62. The planar shape of the second stacked body 702 (the shape viewed from the Z direction) 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. The magnetic sensor 1 further includes an insulating layer (not shown) made of an insulating material and disposed above the upper electrode 62.

[0099] So far, focusing on one MR element 50, the structures of the MR element 50 and the magnetic field generating body 70 have been described. In the present embodiment, the magnetic sensor 1 includes a plurality of MR elements 50. As Figure 7 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 Figure 7 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.

[0100] The two MR elements 50 are also electrically connected through the antiferromagnetic layer 74 of the second stacked body 702. In addition, the two MR elements 50 may be connected in series through the antiferromagnetic layer 74.

[0101] In addition, in the present embodiment, since the magnetic sensor 1 includes a plurality of MR elements 50 and a plurality of magnetic field generating bodies 70, the magnetic sensor 1 includes a plurality of buffer layers 71, a plurality of ferromagnetic layers 72, a plurality of base layers 73, a plurality of antiferromagnetic layers 74, and a plurality of covering layers 75.

[0102] Next, the operation and effects of the magnetic sensor 1 of the present embodiment will be described. In the present embodiment, the base layer 73 is disposed above the MR element 50, the two ferromagnetic layers 72, and the insulating layer 32, and the antiferromagnetic layer 74 is disposed above the base layer 73. The antiferromagnetic layer 74 includes an antiferromagnetic portion 74a that is exchange-coupled with the ferromagnetic layer 72 and defines the magnetization direction of the ferromagnetic layer 72. As will be described later, in the present embodiment, the base portion of the antiferromagnetic layer 74 is flat or substantially flat, and the antiferromagnetic layer 74 can be formed in a state where no structure is provided above the base portion. Thus, according to the present embodiment, a decrease in the film thickness of the antiferromagnetic portion 74a can be suppressed. Thus, according to the present embodiment, the antiferromagnetic portion 74a can be effectively utilized, and as a result, the above-described functions of the antiferromagnetic portion 74a and the function of the magnetic field generating body 70 can be achieved.

[0103] In addition, in the present embodiment, a cover layer 75 is formed above the antiferromagnetic layer 74. The cover layer 75 includes a protection portion 75a that protects the antiferromagnetic portion 74a. According to the present embodiment, by forming the cover layer 75 above the antiferromagnetic layer 74, a decrease in the film thickness of the protection portion 75a can be suppressed. Thus, according to the present embodiment, the protection portion 75a can be effectively used, and as a result, the above-described function of the protection portion 75a can be achieved.

[0104] Hereinafter, the above effects will be described in detail in comparison with a magnetic sensor of a comparative example including a magnetic field generating body of a comparative example. First, the structure of the magnetic sensor of the comparative example will be described. The magnetic sensor of the comparative example includes a magnetic field generating body 170 of the comparative example instead of the magnetic field generating body 70 in the present embodiment.

[0105] The magnetic field generating body 170 includes a buffer layer 171, a ferromagnetic layer 172, an antiferromagnetic layer 173, and a cover layer 174. The buffer layer 171, the ferromagnetic layer 172, the antiferromagnetic layer 173, and the cover layer 174 respectively correspond to the buffer layer 71, the ferromagnetic layer 72, the antiferromagnetic layer 74, and the cover layer 75 in the present embodiment. In the comparative example, the antiferromagnetic layer 173 is in contact with the upper surface of the ferromagnetic layer 172 and is exchange-coupled with the ferromagnetic layer 172. Thus, the magnetization direction of the ferromagnetic layer 172 is defined.

[0106] Figure 11 It is a cross-sectional view showing a method of forming the magnetic field generating body of the comparative example. The magnetic field generating body 170 of the comparative example is formed as follows. First, the stacked film that will later become the MR element 50 is patterned, and two side surfaces 50d (see Figure 10 ) are formed on the stacked film. Next, an insulating layer 32 (see Figure 8 and Figure 10 ) is formed around the stacked film.

[0107] Next, asFigure 11 As shown, a photoresist mask 81 is formed on the laminated film. Next, using the photoresist mask 81, the laminated film is patterned by etching in such a way that two side surfaces 50c are formed on the laminated film. Thus, the laminated film becomes the MR element 50.

[0108] Next, with the photoresist mask 81 remaining, an insulating layer 131, a buffer layer 171, a ferromagnetic layer 172, an antiferromagnetic layer 173, and a cover layer 174 are sequentially formed. Thus, the magnetic field generating body 170 is completed. Next, the photoresist mask 81 is removed. In addition, the photoresist mask 81 may also be formed after patterning the MR element 50.

[0109] As Figure 11 shown, due to the influence of the shadow of the photoresist mask 81, the film thickness of the antiferromagnetic layer 173 becomes smaller as it approaches the photoresist mask 81. Therefore, near the corner where the upper surface 50a and the side surface 50c of the MR element 50 intersect, the blocking temperature of the antiferromagnetic layer 173 decreases, and the heat resistance of the antiferromagnetic layer 173 decreases. Therefore, in an environment where the temperature temporarily or permanently becomes high, the functions of the antiferromagnetic layer 173 and the magnetic field generating body 170 cannot be exerted.

[0110] Similarly, due to the influence of the shadow of the photoresist mask 81, the film thickness of the cover layer 174 becomes smaller as it approaches the photoresist mask 81. Therefore, near the above-mentioned corner, the antiferromagnetic layer 173 cannot be sufficiently protected, and the antiferromagnetic layer 173 may be corroded. If the antiferromagnetic layer 173 is corroded, the functions of the antiferromagnetic layer 173 and the magnetic field generating body 170 cannot be exerted.

[0111] In contrast, in the present embodiment, it is possible to suppress the reduction in the film thickness of each of the antiferromagnetic portion 74a and the protection portion 75a. FIG. 12 is a cross-sectional view showing a method of forming the magnetic field generating body 70 in the present embodiment. The magnetic field generating body 70 in the present embodiment is formed as follows. First, the laminated film that will later become the MR element 50 is patterned to form two side surfaces 50d on the laminated film (refer to Figure 10 ). Next, an insulating layer 32 is formed around the laminated film (refer to Figure 8 and Figure 10 ).

[0112] Next, as Figure 12A shown, a photoresist mask 82 is formed on the laminated film. Next, using the photoresist mask 82, the laminated film is patterned by etching in such a way that two side surfaces 50c are formed on the laminated film. Thus, the laminated film becomes the MR element 50. Next, with the photoresist mask 82 remaining, an insulating layer 33, a buffer layer 71, and a ferromagnetic layer 72 are sequentially formed.

[0113] Next, as Figure 12B shown, the photoresist mask 82 is removed. Next, a base layer 73, an antiferromagnetic layer 74, and a cover layer 75 are sequentially formed on the MR element 50, the ferromagnetic layer 72, and the insulating layer 32. Next, a process of fixing the magnetization direction of the ferromagnetic layer 72 is performed. Thus, the magnetic field generating body 70 is completed. The process of fixing the magnetization direction of the ferromagnetic layer 72 will be described in detail later.

[0114] As Figure 12B shown, in the present embodiment, the antiferromagnetic layer 74 and the cover layer 75 are formed on the laminate of the MR element 50, the ferromagnetic layer 72, the insulating layer 32, and the base layer 73. The upper surface of this laminate is flat or substantially flat. In addition, when forming the antiferromagnetic layer 74 and the cover layer 75, there are no structures such as a photoresist mask on the laminate. Therefore, in the present embodiment, the film thicknesses of the antiferromagnetic layer 74 and the cover layer 75 are constant or substantially constant regardless of the distance from the MR element 50. Thus, according to the present embodiment, it is possible to suppress the film thicknesses of the antiferromagnetic portion 74a and the protection portion 75a from becoming smaller. As a result, according to the present embodiment, the antiferromagnetic portion 74a and the protection portion 75a can be effectively utilized.

[0115] Next, other effects of the present embodiment will be described. The base layer 73 is provided to eliminate the influence of the MR element 50, the ferromagnetic layer 72, and the insulating layer 32, and to improve the crystal orientation of the layers formed on the base layer 73. In the present embodiment, by forming the antiferromagnetic layer 74 on the base layer 73, the crystal orientation of the antiferromagnetic layer 74 can be improved as compared with the case where the base layer 73 does not exist. Accordingly, according to the present embodiment, the antiferromagnetic portion 74a can also be effectively utilized.

[0116] In addition, in the present embodiment, the insulating layer 32 has a function of suppressing the film thickness variation of the layers formed on the MR element 50. That is, if the insulating layer 32 does not exist, a part of each of the base layer 73, the antiferromagnetic layer 74, and the cover layer 75 is formed along the two side surfaces 50d of the MR element 50. In this case, the film thickness of the layers formed along the two side surfaces 50d of the MR element 50 may be different from the film thickness of the layers formed along the upper surface 50a of the MR element 50 and the upper surface of the ferromagnetic layer 72. In contrast, according to the present embodiment, by forming the base layer 73, the antiferromagnetic layer 74, and the cover layer 75 along the upper surface 50a of the MR element 50, the upper surface of the ferromagnetic layer 72, and the upper surface of the insulating layer 32, respectively, the film thickness variation of each layer can be suppressed. Furthermore, by forming the base layer 73, the antiferromagnetic layer 74, and the cover layer 75 by a method with good step coverage, the film thickness variation of each layer can be suppressed more effectively. Accordingly, according to the present embodiment, the antiferromagnetic portion 74a and the protection portion 75a can also be effectively utilized.

[0117] Next, a method for forming the plurality of MR elements 50 in the present embodiment will be briefly described. In the process of forming the plurality of MR elements 50, first, a plurality of initial MR elements that will become the plurality of MR elements 50 are formed. Each of the plurality of initial MR elements includes an initial magnetization fixing layer that will become the magnetization fixing layer 52, a buffer layer 51, a spacer layer 53, a free layer 54, and a cover layer 55.

[0118] Next, the magnetization direction of the initial magnetization fixing layer is fixed to the above-described specified direction by using a laser and an external magnetic field including a component in a specified direction. For example, in the plurality of initial MR elements that will become the plurality of MR elements 50A that constitute the resistance portions R11 and R13 of the first detection circuit 10, while applying an external magnetic field in the X direction, the plurality of initial MR elements are irradiated with a laser. When the irradiation of the laser is completed, 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, and the initial MR element becomes the MR element 50A.

[0119] In addition, in the plurality of initial MR elements that will become the plurality of MR elements 50A that constitute the resistance portions R12 and R14 of the first detection circuit 10, by using an external magnetic field in the -X direction, the magnetization direction of the initial magnetization fixing layer of each of the plurality of initial MR elements can be fixed to the -X direction. In this way, the plurality of MR elements 50A are formed. The plurality of MR elements 50B that constitute each of the resistance portions R21 to R24 of the second detection circuit 20 are also formed by the same method as the plurality of MR elements 50A.

[0120] Next, the process of fixing the magnetization direction of the fixed ferromagnetic layer 72 will be described. The magnetization direction of the ferromagnetic layer 72 is fixed by the same method as that of the magnetization fixing layer 52 of the MR element 50. That is, first, as described with reference to Figure 12A and Figure 12B , after forming the base layer 73, the antiferromagnetic layer 74, and the cover layer 75, the magnetization direction of the ferromagnetic layer 72 is fixed to the above-described specified direction by using a laser and an external magnetic field containing components in a specified direction. For example, for a plurality of ferromagnetic layers 72 respectively disposed near a plurality of MR elements 50A that will later constitute the resistance portions R11 and R12 of the first detection circuit 10, while applying an external magnetic field in the Y direction, the plurality of ferromagnetic layers 72 are irradiated with a laser. When the irradiation of the laser is completed, the magnetization direction of the ferromagnetic layer 72 is fixed in the Y direction.

[0121] In addition, for a plurality of ferromagnetic layers 72 respectively disposed near a plurality of MR elements 50A that will later constitute the resistance portions R13 and R14 of the first detection circuit 10, by using an external magnetic field in the -Y direction, the magnetization directions of the plurality of ferromagnetic layers 72 can be fixed in the -Y direction respectively. The magnetization directions of the plurality of ferromagnetic layers 72 respectively disposed near a plurality of MR elements 50B that constitute the resistance portions R21 to R24 of the second detection circuit 20 are also fixed by the same method as described above.

[0122] In addition, the intensity of the laser used to fix the magnetization direction of the ferromagnetic layer 72 may be smaller than the intensity of the laser used to fix the magnetization direction of the magnetization fixing layer 52. In addition, the intensity of the laser used to fix the magnetization direction of the ferromagnetic layer 72 is preferably such 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.

[0123] [Modification Example]

[0124] Next, the first to eighth modification examples of the magnetic sensor 1 of the present embodiment will be described. First, with reference to Figure 13 the first modification example will be described. Figure 13 is a top view showing the main part of the first modification example of the magnetic sensor 1. In the first modification example, each of the plurality of lower electrodes 61 electrically connects two adjacent MR elements 50 in the first direction D1. Each of the plurality of upper electrodes 62 is disposed above two lower electrodes 61 and electrically connects two adjacent MR elements 50. As a result, a plurality of MR elements 50 arranged in a line in the first direction D1 are connected in series. In the first modification example, the plurality of connection electrodes electrically connect the plurality of lower electrodes 61 or the plurality of upper electrodes 62 in such a manner as to connect in series a group of a plurality of MR elements 50 arranged in a line.

[0125] In addition, in the first modification, a second laminate 702 is interposed between the 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 74 (see Figure 9 and Figure 10 ) of the second laminate 702. In addition, the two MR elements 50 are also connected in series through the antiferromagnetic layer 74.

[0126] Next, a description will be given with reference to Figure 14 the second modification. Figure 14 FIG. is a plan view showing the main part of the second modification of the magnetic sensor 1. In the second modification, two MR elements 50 and three magnetic field generators 70 are arranged between the lower electrode 61 and the upper electrode 62. Here, in order to distinguish the three magnetic field generators 70 from each other, "first", "second", and "third" are used. The first magnetic field generator 70 is arranged between the two MR elements 50 arranged along the first direction D1. The second magnetic field generator 70 is arranged at a position sandwiching one of the two MR elements 50 between the first magnetic field generator 70. The third magnetic field generator 70 is arranged at a position sandwiching the other of the two MR elements 50 between the first magnetic field generator 70.

[0127] Figure 14 The two MR elements 50 shown are connected to the same lower electrode 61 and the same upper electrode 62. The two MR elements 50 may also be connected in parallel in the circuit structure. Here, the two MR elements 50 connected in parallel in the circuit structure are referred to as an element pair. Each of the plurality of lower electrodes 61 electrically connects two adjacent element pairs in the second direction D2. Each of the plurality of upper electrodes 62 is arranged above the two lower electrodes 61 and electrically connects two adjacent element pairs. Thus, a plurality of element pairs arranged in a row in the second direction D2 are connected in series.

[0128] A second laminate 702 is interposed between the two element pairs and the upper electrode 62 that electrically connects the two element pairs. In the second modification, the second laminate 702 is arranged above the four MR elements 50 and the six first laminates 701. In the second modification, the second laminate 702 includes six laminated portions 702a.

[0129] Next, a description will be given with reference to Figure 15 the third modification. Figure 15 FIG. is a plan view showing the main part of the third modification of the magnetic sensor 1. In the third modification, two MR elements 50 arranged along the second direction D2 are arranged between two magnetic field generators 70 arranged along the first direction D1.

[0130] Figure 15The two MR elements 50 shown are connected to the same lower electrode 61 and the same upper electrode 62. The two MR elements 50 are a pair of elements connected in parallel in the circuit structure. Each of the plurality of lower electrodes 61 electrically connects two pairs of elements adjacent in the second direction D2. Each of the plurality of upper electrodes 62 is disposed above two lower electrodes 61 and electrically connects two adjacent pairs of elements. Thus, a plurality of pairs of elements arranged in a line in the second direction D2 are connected in series.

[0131] A second laminate 702 is interposed between the two pairs of elements and the upper electrode 62 that electrically connects the two pairs of elements. In the third modification, the second laminate 702 is disposed above the four MR elements 50 and the four first laminates 701. In the third modification, the second laminate 702 includes four laminated portions 702a.

[0132] Next, refer to Figure 16 to describe a fourth modification. Figure 16 It is a cross-sectional view showing the main part of a fourth modification of the magnetic sensor 1. In the fourth modification, the first laminate 701 includes an antiferromagnetic layer 76 disposed between the buffer layer 71 and the ferromagnetic layer 72 in addition to the buffer layer 71 and the ferromagnetic layer 72. The antiferromagnetic layer 76 is formed of an antiferromagnetic material such as IrMn or PtMn, for example.

[0133] The antiferromagnetic layer 76 is in contact with the lower surface of the ferromagnetic layer 72 and exchanges coupling with the ferromagnetic layer 72. In addition, as described above, the antiferromagnetic portion 74a exchanges coupling with the ferromagnetic layer 72. In the fourth modification, the magnetization direction of the ferromagnetic layer 72 is specified by the exchange coupling between the antiferromagnetic portion 74a and the antiferromagnetic layer 76 with the ferromagnetic layer 72.

[0134] Next, refer to Figure 17 to describe a fifth modification. Figure 17 It is a cross-sectional view showing the main part of a fifth modification of the magnetic sensor 1. In the fifth modification, the first laminate 701 includes a ferromagnetic layer 77 disposed between the buffer layer 71 and the ferromagnetic layer 72 in addition to the buffer layer 71 and the ferromagnetic layer 72. The ferromagnetic layer 77 is formed of a ferromagnetic material containing one or more elements of Co, Fe, and Ni. In the fifth modification, the ferromagnetic layer 77 has magnetization in the same direction as the magnetization of the ferromagnetic layer 72.

[0135] In the fifth modification example, the ferromagnetic layer 72 can also be formed of a ferromagnetic material capable of increasing the exchange coupling energy with the antiferromagnetic portion 74a, and the ferromagnetic layer 77 can be formed of a ferromagnetic material having a saturation magnetic flux density larger than that of the ferromagnetic material constituting the ferromagnetic layer 72. In this case, it is possible to increase the exchange coupling energy between the ferromagnetic body portion composed of the ferromagnetic layers 72 and 77 and the antiferromagnetic portion 74a, 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 72, Co 70 Fe 30 layer can be cited. As an example of the ferromagnetic layer 77, Co 30 Fe 70 layer can be cited.

[0136] Next, a sixth modification example will be described with reference to Figure 18 FIG. Figure 18 FIG. is a cross-sectional view showing the main part of a sixth modification example of the magnetic sensor 1. In the sixth modification example, the first laminate 70,1 includes, in addition to the buffer layer 71 and the ferromagnetic layer 72, a ferromagnetic layer 78 disposed between the buffer layer 71 and the ferromagnetic layer 72, and a nonmagnetic layer 79 disposed between the ferromagnetic layer 72 and the ferromagnetic layer 78. The ferromagnetic layer 78 is formed of a ferromagnetic material containing one or more elements of Co, Fe, and Ni. The ferromagnetic layer 72 and the ferromagnetic layer 78 may be formed of the same ferromagnetic material or different ferromagnetic materials. The nonmagnetic layer 79 is formed of a nonmagnetic metal material such as Ru, for example.

[0137] In the sixth modification example, the ferromagnetic layer 72 and the ferromagnetic layer 78 are ferromagnetically exchange-coupled via the nonmagnetic layer 79 in such a manner that their magnetization directions are the same. The ferromagnetic layer 72 and the ferromagnetic layer 78 have the same-direction magnetization. The thickness of the nonmagnetic layer 79 is set to a thickness such that the exchange coupling between the ferromagnetic layer 72 and the ferromagnetic layer 78 does not disappear.

[0138] Next, a seventh modification example will be described with reference to Figure 19 FIG. Figure 19 FIG. is a cross-sectional view showing the main part of a seventh modification example of the magnetic sensor 1. In the seventh modification example, the first laminate 701 includes a ferromagnetic portion 272A made of a ferromagnetic material instead of the ferromagnetic layer 72. The shape and arrangement of the ferromagnetic portion 272A may be the same as those of the ferromagnetic layer 72.

[0139] The second laminate 702 includes a base portion 272B instead of the base layer 73. The shape and configuration of the base portion 272B may be the same as those of the base layer 73. Further, the base portion 272B includes an intervening portion 272Ba interposed between the ferromagnetic portion 272A and the antiferromagnetic portion 74a, and a non-intervening portion 272Bb other than the intervening portion 272Ba. The laminated portion 702a includes the intervening portion 272Ba instead of the intervening portion 73a.

[0140] In the seventh modification, in particular, the ferromagnetic portion 272A and the base portion 272B are constituted by a single ferromagnetic layer 272. In Figure 19 , the boundary between the ferromagnetic portion 272A and the base portion 272B is indicated by a dashed line.

[0141] Next, Figure 20 the eighth modification will be described. In the eighth modification, two side surfaces 50c of the MR element 50 are formed by etching at least the spacer layer 53, the free layer 54, and the capping layer 55 in the process of patterning the laminated film described with reference to Figure 12A . In this process, a part of the magnetization fixing layer 52 may or may not be etched.

[0142] In the eighth modification, the ferromagnetic layer 72 is disposed so as to rise above the side surface 50c of the MR element 50 and the magnetization fixing layer 52. The insulating layer 33 is formed along the upper surfaces of the side surface 50c of the MR element 50 and the magnetization fixing layer 52.

[0143] In addition, the first to eighth modifications can be arbitrarily combined. For example, the Figure 13 first modification shown in Figure 14 may be combined with the Figure 15 second modification or the

[0144] [Second Embodiment]

[0145] Next, a second embodiment of the present invention will be described. First, the structure of a magnetic sensor system including the magnetic sensor of this embodiment will be described with reference to Figure 21 . Figure 21 is a perspective view showing the magnetic sensor system 200 in this embodiment.

[0146] The magnetic sensor system 200 includes the magnetic sensor 201 of this embodiment and a magnetic field generating unit 202 that generates a predetermined magnetic field. In this embodiment, the magnetic field generating unit 202 is a magnet configured to apply a partial magnetic field, which is a part of the generated magnetic field, to the magnetic sensor 201. The 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.

[0147] As shown Figure 21 in the present embodiment, the magnetization direction of the magnetic field generating unit 202 is the Y direction, and the direction of the second magnetic field component Hy is the -Y direction. When the magnetic field generating unit 202 moves in the Y direction from a specified position, the direction of the first magnetic field component Hz becomes the Z direction, and when the magnetic field generating unit 202 moves in the -Y direction from the specified position, the direction of the first magnetic field component Hz becomes the -Z direction.

[0148] Next, with reference to Figure 22 the schematic structure of the magnetic sensor 201 of the present embodiment will be described. Figure 22 is a circuit diagram showing the circuit structure of the magnetic sensor 201.

[0149] 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 voltage or current of a specified magnitude is applied to the power supply port V3. The ground port G3 is grounded.

[0150] The resistor parts R31 to R34 each include a plurality of MR elements 50. The structure of the plurality of MR elements 50 is the same as that of the first embodiment. That is, as in the first embodiment Figure 9 and Figure 10 shown, the plurality of MR elements 50 each include a buffer layer 51, a magnetization fixing layer 52, a spacer layer 53, a free layer 54, and a cover layer 55.

[0151] In Figure 22 , a plurality of solid arrows depicted so as to overlap the resistor parts R31 to R34 respectively indicate the magnetization directions of the magnetization fixing layers 52 in the resistor parts R31 to R34. In the example shown in Figure 22 , the directions of the main components of the magnetization of the magnetization fixing layers 52 in the resistor parts R31 and R34 are the X direction. The directions of the main components of the magnetization of the magnetization fixing layers 52 in the resistor parts R32 and R33 are the -X direction. The free layers 54 in the resistor parts R31 to R34 each have a shape anisotropy in which the direction of the easy magnetization axis becomes parallel to the Y direction.

[0152] The resistance units R31 to R34 each further include a plurality of magnetic field generators 70. The structure of the plurality of magnetic field generators 70 is the same as that of the first embodiment. The plurality of magnetic field generators 70 includes pairs of the plurality of magnetic field generators 70 each constituted by two magnetic field generators 70. The two magnetic field generators 70 described above 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 the direction parallel to the Y direction as a main component.

[0153] In Figure 22 , 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 the Y direction. The directions of the main components of the bias magnetic fields in the resistance units R32 and R33 are the -Y direction.

[0154] In Figure 22 , the plurality of hollow arrows depicted so as to overlap with the resistance units R31 to R34 respectively indicate the magnetization directions of the free layers in each of the resistance units R31 to R34 when a partial magnetic field is not applied to the magnetic sensor 201. The directions of the main components of the magnetization of the free layers in each of the resistance units R31 and R34 are the Y direction, which is the same as the direction of the main component of the bias magnetic field in the resistance units R31 and R34. The directions of the main components of the magnetization of the free layers in each of the resistance units R32 and R33 are the -Y direction, which is the same as the direction of the main component of the bias magnetic field in the resistance units R32 and R33.

[0155] Next, with reference to Figures 23 to 25 , the structure of the magnetic sensor 201 will be specifically described. Figure 23 is a perspective view showing a part of the magnetic sensor 201. Figure 24 is a top view showing a part of the magnetic sensor 201. Figure 25 is a side view showing a part of the magnetic sensor 201.

[0156] The magnetic sensor 201 further includes a substrate 230. The magnetic sensor 201 is constituted by forming a plurality of elements other than the substrate 230 on the substrate 230.

[0157] The magnetic sensor 201 further includes at least one magnetic yoke made of a soft magnetic material. When viewed from the Z direction, the at least one magnetic yoke has a shape that is long in the Y direction. In addition, the at least one magnetic yoke generates a magnetic field component in the direction parallel to the X direction based on Figure 21 the first magnetic field component Hz shown.

[0158] AsFigures 23 to 25 As shown, in the present embodiment, in particular, the magnetic sensor 201 includes a plurality of magnetic yokes 250 configured to be arranged in the X direction as at least one magnetic yoke. The plurality of magnetic yokes 250 each have, for example, a rectangular parallelepiped shape that is longer in the Y direction. The shapes of the plurality of magnetic yokes 250 are the same. The plurality of magnetic yokes 250 each have 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.

[0159] The plurality of MR elements 50 are respectively arranged at positions where the magnetic field components generated by the plurality of magnetic yokes 250 are applied. In the present embodiment, in particular, the MR elements 50 are respectively arranged near the -Z direction ends of the plurality of magnetic yokes 250. In addition, the plurality of MR elements 50 are arranged such that a plurality of them are arranged along the first end face 250a or the second end face 250b of each of the plurality of magnetic yokes 250. Hereinafter, a plurality of MR elements 50 arranged along the first end face 250a are denoted by the symbol 50C, and a 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.

[0160] When viewed from the Z direction, the plurality of MR elements 50C and the plurality of MR elements 50D may overlap with the plurality of magnetic yokes 250 or may not overlap with the plurality of magnetic yokes 250. In Figures 23 to 25 the example shown, when viewed from the Z direction, 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.

[0161] As Figure 23 and Figure 24 shown, a plurality of magnetic field generators 70 configured to sandwich the MR element 50C are denoted by the symbol 70C, and a plurality of magnetic field generators 70 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 above two magnetic yokes 90C are arranged 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 above two magnetic yokes 90D are arranged on both sides of one MR element 50D in a direction parallel to the X direction.

[0162] The plurality of magnetic yokes 90C have the function of guiding the magnetic field components generated by the plurality of magnetic yokes 250 to the plurality of MR elements 50C. The plurality of magnetic yokes 90D have the function of guiding the magnetic field components generated by the plurality of magnetic yokes 250 to the plurality of MR elements 50D.

[0163] 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. In addition, the lower electrode 61 and the upper electrode 62 are shown in Figures 26 to 28 as described later.

[0164] The wiring portion 211 includes: a first wiring that electrically connects the 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 the 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 portion R31 is composed of the plurality of MR elements 50C electrically connected by the first wiring. The resistance portion R32 is composed of the plurality of MR elements 50C electrically connected by the second wiring.

[0165] The wiring portion 212 includes: a third wiring that electrically connects the 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 the 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 portion R33 is composed of the plurality of MR elements 50D electrically connected by the third wiring. The resistance portion R34 is composed of the plurality of MR elements 50D electrically connected by the fourth wiring.

[0166] Next, the operation of the magnetic sensor 201 will be described. In a state where the first magnetic field component Hz does not exist, and as a result, in a state where the magnetic field components generated by the plurality of magnetic yokes 250 also do 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 a direction parallel to the Y direction.

[0167] When the direction of the first magnetic field component Hz is the Z direction, the direction of the magnetic field component received by each of the plurality of MR elements 50C constituting the resistance units 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 units 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 no magnetic field component exists, the resistance values of the plurality of MR elements 50C constituting the resistance unit R31 and the resistance values of the plurality of MR elements 50D constituting the resistance unit R33 decrease, and the resistance values of the plurality of MR elements 50C constituting the resistance unit R32 and the resistance values of the plurality of MR elements 50D constituting the resistance unit R34 increase. As a result, the resistance values of the resistance units R31 and R33 decrease, and the resistance values of the resistance units R32 and R34 increase.

[0168] When the direction of the first magnetic field component Hz is the -Z direction, the direction of the magnetic field component and the change in the resistance value of each of the resistance units R31 to R34 are opposite to those in the case where the direction of the first magnetic field component Hz is the Z direction described above.

[0169] The amount of change in the resistance value of each of the resistance units R31 to R34 depends on the intensity of the magnetic field component received by each of the plurality of MR elements 50C and the plurality of MR elements 50D. When the intensity of the magnetic field component increases, the resistance values of the resistance units R31 to R34 change in the direction in which their increase amounts or decrease amounts respectively increase. When the intensity of the magnetic field component decreases, the resistance values of the resistance units R31 to R34 change in the direction in which their increase amounts or decrease amounts respectively decrease. The intensity of the magnetic field component depends on the intensity of the first magnetic field component Hz.

[0170] Thus, when the direction and intensity of the first magnetic field component Hz change, the resistance values of the resistance portions R31 to R34 change in such a manner that the resistance values of the resistance portions R31 and R33 increase and the resistance values of the resistance portions R32 and R34 decrease, or the resistance values of the resistance portions R31 and R33 decrease and the resistance values of the resistance portions R32 and R34 increase. As a result, the potential at the connection point of the resistance portions R31 and R32, i.e., the potential of the output port E31, and the potential at the connection point of the resistance portions R33 and R34, i.e., 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 also 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.

[0171] The magnetic sensor system 200 may also include the Figure 1 and Figure 2 processor 2 shown in the first embodiment. The processor 2 may 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 generating unit 202 (see Figure 21 ).

[0172] Next, a detailed description will be given of the plurality of magnetic yokes 90C and the plurality of magnetic yokes 90D with reference to Figures 26 to 28 . Figure 26 is a top view showing the main part of the magnetic sensor 201. Figure 27 is a view showing Figure 26 a partial cross-sectional view of the position indicated by the line 27-27 in Figure 28 is a view showing Figure 26 a partial cross-sectional view of the position indicated by the line 28-28 in

[0173] Hereinafter, any one of the plurality of magnetic yokes 90C and the plurality of magnetic yokes 90D will be denoted by the symbol 90. The structures and shapes of the MR element 50 and the magnetic field generating body 70, and the positional relationship between the MR element 50 and the magnetic field generating body 70 are the same as those in the first embodiment. In addition, the structures and shapes of the first and second laminated bodies 701 and 702, and the positional relationship between the MR element 50 and the first and second laminated bodies 701 and 702 are also the same as those in the first embodiment.

[0174] Here, focusing on an MR element 50, the structure of the yoke 90 will be described. Two yokes 90 are arranged on both sides of the MR element 50 in a direction parallel to the X direction. The magnetic sensor 201 also includes an insulating layer 232 made of an insulating material such as Al2O3 or SiO2. The insulating layer 232 is arranged on both sides of the MR element 50 in a direction parallel to the X direction. In the present embodiment, in particular, the insulating layer 232 is arranged around the MR element 50 and the ferromagnetic layer 72 of the magnetic field generating body 70.

[0175] The two yokes 90 are embedded in the insulating layer 232. An insulating layer 232 is interposed between the MR element 50 and the two yokes 90, and between the lower electrode 61 and the two yokes 90. Each of the two yokes 90 may further include a buffer layer interposed between the magnetic layer and the insulating layer 232, and a covering layer arranged on the magnetic layer, in addition to 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 yokes 90 are respectively arranged to rise to the side surface 50d of the MR element 50. When viewed from the Z direction, a part of each of the two yokes 90 overlaps with a part of the MR element 50.

[0176] The two yokes 90 are arranged between two magnetic field generating bodies 70 arranged at a predetermined interval in a direction parallel to the Y direction. The ferromagnetic layer 72 of the magnetic field generating body 70 (the first laminate 701) is arranged to overlap with the two yokes 90 when viewed from the Y direction or the -Y direction.

[0177] The ferromagnetic layer 72 is arranged to rise to the yoke 90. When viewed from the Z direction, a part of the ferromagnetic layer 72 overlaps with a part of the yoke 90. The magnetic sensor 201 also includes an insulating layer 233 made of an insulating material such as Al2O3 or SiO2 and interposed between the ferromagnetic layer 72 and the yoke 90. A part of the buffer layer 71 of the magnetic field generating body 70 (the first laminate 701) is interposed between the ferromagnetic layer 72 and the insulating layer 233.

[0178] In the present embodiment, the base layer 73 is arranged above the MR element 50, the two ferromagnetic layers 72, the two yokes 90, and the insulating layer 232. The upper surface of each of the two yokes 90 may be in contact with the base layer 73. The magnetic sensor 201 also includes: an insulating layer 231 made of an insulating material such as Al2O3 or SiO2 and interposed between the substrate 230 (refer to Figure 24 ) and the lower electrode 61; and an insulating layer (not shown) made of an insulating material and arranged above the upper electrode 62.

[0179] Other structures, operations, and effects in the present embodiment are the same as those in the first embodiment.

[0180] [Third Embodiment]

[0181] Next, refer to Figures 29 to 31 A third embodiment of the present invention will be described. Figure 29 It is a plan view showing the main part of the magnetic sensor according to this embodiment. Figure 30 Yes Figure 29 A sectional view of a portion of the cross section at the position indicated by line 30-30. Figure 31 Yes Figure 29 A sectional view of a portion of the cross section at the position indicated by line 31-31.

[0182] The following describes the differences in the structure of the magnetic sensor 201 of this embodiment from that of the second embodiment, focusing on a single MR element 50. In this embodiment, two magnetic field generators 70 are disposed at a predetermined distance from each MR element 50. Therefore, the ferromagnetic layers 72 of each of the two magnetic field generators 70 are disposed at a predetermined distance from each MR element 50.

[0183] The two magnetic field generators 70 are disposed at predetermined intervals from the two yokes 90 . Therefore, the ferromagnetic layers 72 of the two magnetic field generators 70 are disposed at predetermined intervals from the two yokes 90 .

[0184] In this embodiment, the insulating layer 233 is interposed between the ferromagnetic layer 72 and the lower electrode 61 and the insulating layer 232. The magnetic sensor 201 further includes an insulating layer 234 made of an insulating material such as Al2O3 or SiO2 and interposed between the two yokes 90 and the lower electrode 61 and the insulating layer 232.

[0185] The other structures, functions and effects in this embodiment are the same as those in the second embodiment.

[0186] Furthermore, the present invention is not limited to the above-described embodiments and is capable of various modifications. For example, the magnetic sensor of the present invention may include: the first and second detection circuits 10 and 20 of the first embodiment; and the magnetic sensor 201 of the second embodiment as a third detection circuit. In this magnetic sensor, the third detection circuit (magnetic sensor 201) may be configured to detect the component of the target magnetic field parallel to the Z direction. This magnetic sensor may also be a geomagnetic sensor in which the target magnetic field is the earth's magnetism.

[0187] Alternatively, the MR element 50 may be configured by stacking the buffer layer 51 , the free layer 54 , the gap layer 53 , the magnetization fixed layer 52 , and the cap layer 55 in this order from the lower electrode 61 side.

[0188] As described above, the magnetic sensor of the present invention includes: at least one magnetoresistive effect element including a plurality of stacked magnetic films; a first ferromagnetic layer including a ferromagnetic material and configured to overlap at least one magnetoresistive effect element when viewed in a first direction orthogonal to the stacking direction of the plurality of magnetic films; an insulating layer including an insulating material and disposed on both sides of at least one magnetoresistive effect element in a second direction orthogonal to the stacking direction and the first direction, respectively; a base layer disposed above at least one magnetoresistive effect element, the first ferromagnetic layer, and the insulating layer; and an antiferromagnetic layer disposed above the base layer. The antiferromagnetic layer includes: a first antiferromagnetic portion facing the first ferromagnetic layer via the base layer, and a non-facing portion facing at least one magnetoresistive effect element and the insulating layer via the base layer but not facing the first ferromagnetic layer.

[0189] In the magnetic sensor of the present invention, the first ferromagnetic layer and the first antiferromagnetic portion may also constitute a magnetic field generating body that generates a magnetic field applied to at least one magnetoresistive effect element. The base layer may also include a ferromagnetic material. A portion of the base layer located between the first ferromagnetic layer and the first antiferromagnetic portion may also constitute a magnetic field generating body together with the first ferromagnetic layer and the first antiferromagnetic portion.

[0190] In addition, in the magnetic sensor of the present invention, at least one magnetoresistive effect element may be a first magnetoresistive effect element and a second magnetoresistive effect element. The first magnetoresistive effect element and the second magnetoresistive effect element may be connected in series via the antiferromagnetic layer. The first magnetoresistive effect element and the second magnetoresistive effect element may be arranged along the first direction. Alternatively, the first magnetoresistive effect element and the second magnetoresistive effect element may be arranged along the second direction.

[0191] In addition, the magnetic sensor of the present invention may further include: a second ferromagnetic layer including a ferromagnetic material and disposed at a position sandwiching at least one magnetoresistive effect element between the first ferromagnetic layer in the first direction. The antiferromagnetic layer may further include a second antiferromagnetic portion facing the second ferromagnetic layer via the base layer. The first ferromagnetic layer and the first antiferromagnetic portion may constitute a first magnetic field generating body that generates a first magnetic field applied to at least one magnetoresistive effect element. The second ferromagnetic layer and the second antiferromagnetic portion may constitute a second magnetic field generating body that generates a second magnetic field applied to at least one magnetoresistive effect element. At least one magnetoresistive effect element may be a first magnetoresistive effect element and a second magnetoresistive effect element. The first magnetoresistive effect element and the second magnetoresistive effect element may be connected in parallel in a circuit structure.

[0192] In addition, in the magnetic sensor of the present invention, the maximum size of the first ferromagnetic layer in the stacking direction may be greater than the maximum size of the base layer in the stacking direction.

[0193] In addition, in the magnetic sensor of the present invention, the plurality of magnetic films may also include a free layer whose magnetization direction can vary according to the target magnetic field. The maximum size of the free layer in the stacking direction may also be larger than the maximum size of the base layer in the stacking direction.

[0194] In addition, in the magnetic sensor of the present invention, the plurality of magnetic films may also include a free layer whose magnetization direction can vary according to the target magnetic field. The first ferromagnetic layer may also have a side surface facing at least one magnetoresistive effect element. The side surface may also include an inclined portion facing the free layer and inclined with respect to the stacking direction. The angle formed by the inclined portion and the stacking direction may also be in the range of 20° or more and 90° or less.

[0195] In addition, in the magnetic sensor of the present invention, at least one magnetoresistive effect element may also have a first surface facing a non-opposing portion and a second surface on the side opposite to the first surface. The distance between the non-opposing portion and the second surface may also be greater than the distance between the first surface and the second surface.

[0196] In addition, the magnetic sensor of the present invention may further include: two magnetic yokes, which are arranged on both sides of at least one magnetoresistive effect element in the second direction and each include a soft magnetic material. The base layer may also be arranged above at least one magnetoresistive effect element, the first ferromagnetic layer, the insulating layer, and the two magnetic yokes.

[0197] In addition, the magnetic sensor of the present invention may further include: a first port; a second port; a third port; a first resistance portion, which is arranged between the first port and the second port in the circuit structure; and a second resistance portion, which is arranged between the second port and the third port in the circuit structure. Each of the first resistance portion and the second resistance portion may include at least one magnetoresistive effect element, a first ferromagnetic layer, an insulating layer, a base layer, and an antiferromagnetic layer. The plurality of magnetic films may also include a free layer whose magnetization direction can vary according to the target magnetic field. In the first resistance portion, the first ferromagnetic layer and the first antiferromagnetic portion may also constitute a first magnetic field generating body that generates a first magnetic field applied to at least one magnetoresistive effect element. In the second resistance portion, the first ferromagnetic layer and the first antiferromagnetic portion may also constitute a second magnetic field generating body that generates a second magnetic field applied to at least one magnetoresistive effect element. The first magnetic field may also include a component in one direction parallel to the first direction, i.e., the first magnetic field direction, as the main component. The second magnetic field may also include a component in the second magnetic field direction opposite to the first magnetic field direction as the main component. In the first resistance portion, in the case where no target magnetic field is applied to the magnetic sensor, the magnetization of the free layer may also include a component in the first magnetic field direction. In the second resistance portion, in the case where no target magnetic field is applied to the magnetic sensor, the magnetization of the free layer may also include a component in the second magnetic field direction.

[0198] It is clear from the above description that the present invention can be implemented in various forms and modifications. Therefore, within the scope of the equivalents of the claims, the present invention can be implemented even in forms other than the best mode described above.

Claims

1. A magnetic sensor, characterized in that: It includes: At least one magnetoresistive effect element, which includes a plurality of stacked magnetic films; A first ferromagnetic layer, which includes a ferromagnetic material and is configured to overlap with the at least one magnetoresistive effect element when viewed from a first direction orthogonal to the stacking direction of the plurality of magnetic films; An insulating layer, which includes an insulating material and is disposed on both sides of the at least one magnetoresistive effect element in a second direction orthogonal to the stacking direction and the first direction respectively; A base layer, which is disposed above the at least one magnetoresistive effect element, the first ferromagnetic layer and the insulating layer; and An antiferromagnetic layer, which is disposed on the base layer, The antiferromagnetic layer includes: a first antiferromagnetic portion opposite to the first ferromagnetic layer via the base layer, and a non-opposite portion opposite to the at least one magnetoresistive effect element and the insulating layer via the base layer but not opposite to the first ferromagnetic layer.

2. The magnetic sensor according to claim 1, characterized in that: The first ferromagnetic layer and the first antiferromagnetic portion constitute a magnetic field generating body that generates a magnetic field applied to the at least one magnetoresistive effect element.

3. The magnetic sensor according to claim 2, characterized in that: The base layer includes a ferromagnetic material, A portion of the base layer located between the first ferromagnetic layer and the first antiferromagnetic portion constitutes the magnetic field generating body together with the first ferromagnetic layer and the first antiferromagnetic portion.

4. The magnetic sensor according to claim 1, characterized in that: The at least one magnetoresistive effect element is a first magnetoresistive effect element and a second magnetoresistive effect element, The first magnetoresistive effect element and the second magnetoresistive effect element are connected in series via the antiferromagnetic layer.

5. The magnetic sensor according to claim 4, characterized in that: The first magnetoresistive effect element and the second magnetoresistive effect element are arranged along the first direction.

6. The magnetic sensor according to claim 4, characterized in that: The first magnetoresistive effect element and the second magnetoresistive effect element are arranged along the second direction.

7. The magnetic sensor according to claim 1, characterized in that: It further includes: a second ferromagnetic layer, which includes a ferromagnetic material and is disposed at a position where the at least one magnetoresistive effect element is sandwiched between the first ferromagnetic layer in the first direction, The antiferromagnetic layer further includes a second antiferromagnetic portion opposite to the second ferromagnetic layer via the base layer, The first ferromagnetic layer and the first antiferromagnetic portion constitute a first magnetic field generating body that generates a first magnetic field applied to the at least one magnetoresistive effect element, The second ferromagnetic layer and the second antiferromagnetic portion constitute a second magnetic field generating body that generates a second magnetic field applied to the at least one magnetoresistive effect element.

8. The magnetic sensor according to claim 7, characterized in that: The at least one magnetoresistive effect element is a first magnetoresistive effect element and a second magnetoresistive effect element, The first magnetoresistive effect element and the second magnetoresistive effect element are connected in parallel in the circuit structure.

9. The magnetic sensor according to claim 1, wherein the maximum size of the first ferromagnetic layer in the stacking direction is larger than the maximum size of the base layer in the stacking direction.

10. The magnetic sensor according to claim 1, wherein the plurality of magnetic films include a free layer whose magnetization direction can vary according to the target magnetic field, the maximum size of the free layer in the stacking direction is larger than the maximum size of the base layer in the stacking direction.

11. The magnetic sensor according to claim 1, wherein the plurality of magnetic films include a free layer whose magnetization direction can vary according to the target magnetic field, the first ferromagnetic layer has a side surface opposite to the at least one magnetoresistive effect element, the side surface includes an inclined portion opposite to the free layer and inclined with respect to the stacking direction, the angle formed by the inclined portion and the stacking direction is in the range of 20° or more and 90° or less.

12. The magnetic sensor according to claim 1, wherein the at least one magnetoresistive effect element has a first surface opposite to the non-opposing portion and a second surface on the side opposite to the first surface, the distance between the non-opposing portion and the second surface is larger than the distance between the first surface and the second surface.

13. The magnetic sensor according to claim 1, wherein it further includes: two magnetic yokes, which are arranged on both sides of the at least one magnetoresistive effect element in the second direction and each include a soft magnetic material, the base layer is arranged above the at least one magnetoresistive effect element, the first ferromagnetic layer, the insulating layer, and the two magnetic yokes.

14. The magnetic sensor according to claim 1, wherein it further includes: a first port; a second port; a third port; a first resistor portion, which is arranged between the first port and the second port in the circuit structure; and a second resistor portion, which is arranged between the second port and the third port in the circuit structure, the first resistor portion and the second resistor portion each include the at least one magnetoresistive effect element, the first ferromagnetic layer, the insulating layer, the base layer, and the antiferromagnetic layer, the plurality of magnetic films include a free layer whose magnetization direction can vary according to the target magnetic field, in the first resistor portion, the first ferromagnetic layer and the first antiferromagnetic portion constitute a first magnetic field generating body that generates a first magnetic field applied to the at least one magnetoresistive effect element, in the second resistor portion, the first ferromagnetic layer and the first antiferromagnetic portion constitute a second magnetic field generating body that generates a second magnetic field applied to the at least one magnetoresistive effect element, the first magnetic field includes a component in the first magnetic field direction as the main component, and the first magnetic field direction is a direction parallel to the first direction, the second magnetic field includes a component in the second magnetic field direction opposite to the first magnetic field direction as the main component, in the first resistor portion, in the case where the target magnetic field is not applied to the magnetic sensor, the magnetization of the free layer includes a component in the first magnetic field direction, In the second resistance portion, in a case where the object magnetic field is not applied to the magnetic sensor, the magnetization of the free layer includes a component in the second magnetic field direction.

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