magnetic sensor

Abstract

To realize a magnetic sensor configured to apply a stable bias magnetic field to a yoke.SOLUTION: A magnetic sensor 1 includes: an MR element 50; two yokes 90, each yoke including a magnetic layer made of a soft magnetic material and being adjacent to the MR element 50 with a predetermined spacing; and two magnetic field generators 70, each magnetic field generator including a ferromagnetic part 72 made of a ferromagnetic material and an antiferromagnetic part 73 made of an antiferromagnetic material, the antiferromagnetic part 73 being exchange-coupled with the ferromagnetic part 72, for generating a magnetic field applied to the two yokes 90.SELECTED DRAWING: Figure 11

Description

[Technical Field]

[0001] The present invention relates to a magnetic sensor including a magnetoresistive element and a yoke adjacent to the magnetoresistive element. [Background technology]

[0002] In recent years, magnetic sensors have been used in a variety of applications. A known magnetic sensor uses a spin-valve magnetoresistive element provided on a substrate. The spin-valve magnetoresistive element has a fixed magnetization layer with a fixed magnetization direction, a free layer with a magnetization direction that can change depending on the direction of the target magnetic field, and a gap layer disposed between the fixed magnetization layer and the free layer.

[0003] Some magnetic sensors include a soft magnetic material that converges the magnetic field of the measurement target onto the magnetoresistive element to improve the sensor's sensitivity. These magnetic sensors may also include a bias magnetic field generator that applies a bias magnetic field to the soft magnetic material to reduce hysteresis in the output signal.

[0004] Patent document 1 discloses a magnetic sensor including a magnetoresistive element, two magnetic converging parts made of soft magnetic material and arranged to sandwich the magnetoresistive element, and two or four hard bias parts that apply a magnetic field to the two magnetic converging parts.

[0005] Patent document 2 discloses a magnetic sensor comprising a magnetoresistive element, two yoke portions made of soft magnetic material and arranged to sandwich the magnetoresistive element, and two bias magnetic field generating portions that apply a magnetic field to the two yoke portions. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2018-194534 [Patent Document 2] Japanese Patent Publication No. 2022-038821 Summary of the Invention [Problem to be solved by the invention]

[0007] A magnetic sensor using a bias magnetic field generating unit made of a hard magnetic material as a means for generating a bias magnetic field, as described in Patent Document 1, has the following problems. Such magnetic sensors are typically used under the condition that the strength of the magnetic field to be detected does not exceed the coercive force of the hard magnetic material. However, because magnetic sensors are used in a variety of environments, an external magnetic field whose strength exceeds the coercive force of the hard magnetic material may be temporarily applied to the bias magnetic field generating unit. When such an external magnetic field is temporarily applied to the bias magnetic field generating unit, the magnetization direction of the bias magnetic field generating unit may change from its original direction and remain changed from its original direction even after the external magnetic field is removed. In this case, the direction of the bias magnetic field changes from the desired direction.

[0008] The present invention has been made in view of the above problems, and an object of the present invention is to provide a magnetic sensor that can apply a stable bias magnetic field to the yoke. [Means for solving the problem]

[0009] The magnetic sensor of the present invention comprises a magnetoresistive element, at least one yoke including a magnetic layer made of a soft magnetic material and adjacent to the magnetoresistive element with a predetermined gap therebetween, and at least one magnetic field generator including a ferromagnetic portion made of a ferromagnetic material and an antiferromagnetic portion made of an antiferromagnetic material and exchange-coupled with the ferromagnetic portion, and configured to generate a magnetic field applied to the at least one yoke. [Effects of the Invention]

[0010] In the magnetic sensor of the present invention, at least one magnetic field generator includes a ferromagnetic portion made of a ferromagnetic material and an antiferromagnetic portion made of an antiferromagnetic material and exchange-coupled with the ferromagnetic portion, and is configured to generate a magnetic field to be applied to at least one yoke, thereby achieving the effect of applying a stable bias magnetic field to the yoke. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a perspective view showing a magnetic sensor device including a magnetic sensor according to a first embodiment of the present invention. [Figure 2] FIG. 1 is a functional block diagram showing a configuration of a magnetic sensor device according to a first embodiment of the present invention. [Figure 3] 1 is a circuit diagram showing a circuit configuration of a magnetic sensor according to a first embodiment of the present invention. [Figure 4] FIG. 2 is a perspective view showing a part of a first detection circuit according to the first embodiment of the present invention. [Figure 5] FIG. 2 is a plan view showing a part of a first detection circuit according to the first embodiment of the present invention. [Figure 6] FIG. 3 is a plan view showing a part of a second detection circuit in the first embodiment of the present invention. [Figure 7] 1 is a plan view showing a main part of a magnetic sensor according to a first embodiment of the present invention. [Figure 8] 1 is a plan view showing a magnetoresistive element, a yoke, a magnetic field generator, and an insulating layer according to a first embodiment of the present invention. [Figure 9] 9 is a cross-sectional view showing a part of a cross section taken along line 9-9 in FIG. 7. [Figure 10] 8 is a cross-sectional view showing a part of a cross section taken along line 10-10 in FIG. 7. [Figure 11] 11 is a cross-sectional view showing a part of a cross section taken along line 11-11 in FIG. 7. [Figure 12] FIG. 2 is a plan view showing a main part of a first modified example of the magnetic sensor according to the first embodiment of the present invention. [Figure 13] FIG. 10 is a cross-sectional view showing a main part of a second modified example of the magnetic sensor according to the first embodiment of the present invention. [Figure 14] FIG. 10 is a cross-sectional view showing a main part of a third modified example of the magnetic sensor according to the first embodiment of the present invention. [Figure 15] FIG. 10 is a cross-sectional view showing a main part of a fourth modified example of the magnetic sensor according to the first embodiment of the present invention. [Figure 16] FIG. 10 is a cross-sectional view showing a main part of a fifth modified example of the magnetic sensor according to the first embodiment of the present invention. [Figure 17] FIG. 10 is a plan view showing a main part of a magnetic sensor according to a second embodiment of the present invention. [Figure 18] 18 is a cross-sectional view showing a part of the cross section at the position indicated by line 18-18 in FIG. 17. [Figure 19] 19 is a cross-sectional view showing a part of a cross section taken along line 19-19 in FIG. 17. [Figure 20] 18 is a cross-sectional view showing a part of a cross section taken along line 20-20 in FIG. 17. [Figure 21] FIG. 10 is a cross-sectional view showing a main part of a first modified example of the magnetic sensor according to the second embodiment of the present invention. [Figure 22] FIG. 10 is a cross-sectional view showing a main part of a second modified example of the magnetic sensor according to the second embodiment of the present invention. [Figure 23] FIG. 10 is a cross-sectional view showing a main part of a third modified example of the magnetic sensor according to the second embodiment of the present invention. [Figure 24] FIG. 10 is a plan view showing a main part of a magnetic sensor according to a third embodiment of the present invention. [Figure 25] 25 is a cross-sectional view showing a part of the cross section at the position indicated by the line 25-25 in FIG. 24. [Figure 26] 26 is a cross-sectional view showing a part of the cross section at the position indicated by line 26-26 in FIG. 24. [Figure 27] FIG. 10 is a plan view showing a main part of a magnetic sensor according to a fourth embodiment of the present invention. [Figure 28] 28 is a cross-sectional view showing a part of the cross section at the position indicated by line 28-28 in FIG. 27. [Figure 29] 29 is a cross-sectional view showing a part of a cross section taken along line 29-29 in FIG. 27. [Figure 30] FIG. 10 is a perspective view showing a magnetic sensor system including a magnetic sensor according to a fifth embodiment of the present invention. [Figure 31] FIG. 10 is a circuit diagram showing a circuit configuration of a magnetic sensor according to a fifth embodiment of the present invention. [Figure 32] FIG. 10 is a perspective view showing a part of a magnetic sensor according to a fifth embodiment of the present invention. [Figure 33] FIG. 10 is a plan view showing a part of a magnetic sensor according to a fifth embodiment of the present invention. [Figure 34] FIG. 11 is a side view showing a part of a magnetic sensor according to a fifth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0012] [First embodiment] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. First, the configuration of a magnetic sensor device including a magnetic sensor according to a first embodiment of the present invention will be described with reference to Fig. 1 and Fig. 2. Fig. 1 is a perspective view showing the magnetic sensor device according to this embodiment. Fig. 2 is a functional block diagram showing the configuration of the magnetic sensor device according to this embodiment.

[0013] The magnetic sensor device 100 of this embodiment includes a magnetic sensor 1 according to this embodiment and a processor 2. The magnetic sensor 1 is configured to detect a target magnetic field, which is a magnetic field to be detected by the magnetic sensor 1, and generate at least one detection signal. The magnetic sensor 1 may be a geomagnetic sensor that detects geomagnetism, a magnetic sensor for an angle sensor or magnetic encoder that detects a rotating magnetic field, or a magnetic sensor for a current sensor that detects a magnetic field generated by a current to be detected.

[0014] The processor 2 is configured to generate at least one detection value corresponding to the target magnetic field based on the at least one detection signal. The processor 2 is configured, for example, by an application specific integrated circuit (ASIC).

[0015] The magnetic sensor 1 and the processor 2 each have the form of a rectangular parallelepiped chip. The magnetic sensor 1 has an upper surface 1a and a lower surface 1b located opposite each other, and four side surfaces connecting the upper surface 1a and the lower surface 1b. The processor 2 has an upper surface 2a and a lower surface 2b located opposite each other, 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, with the lower surface 1b of the magnetic sensor 1 facing the upper surface 2a of the processor 2. The magnetic sensor 1 is bonded to the processor 2, for example, by adhesive.

[0016] Here, the X direction, Y direction, and Z direction are defined as shown in FIG. 1. The X direction, Y direction, and Z direction are perpendicular to one another. In this embodiment, the Z direction is a direction perpendicular to the top surface 1a of the magnetic sensor 1, and is a direction from the bottom surface 1b of the magnetic sensor 1 toward the top surface 1a. The direction opposite the X direction is the -X direction, the direction opposite the Y direction is the -Y direction, and the direction opposite the Z direction is the -Z direction.

[0017] Hereinafter, a position further in the Z direction than the reference position will be referred to as "above," and a position on the opposite side of "above" than the reference position will be referred to as "below." Furthermore, with regard to the components of the magnetic sensor 1, the surface located at the end in the Z direction will be referred to as the "top surface," and the surface located at the end in the -Z direction will be referred to as the "bottom surface." Furthermore, the expression "when viewed from a specified direction (e.g., the Z direction)" means viewing the object from a position away from the specified direction or in one direction parallel to the specified direction.

[0018] 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 of the plurality of first pads and the plurality of second pads are connected to each other by a bonding wire.

[0019] The magnetic sensor 1 includes a first detection circuit 10 and a second detection circuit 20. The first and second detection circuits 10, 20 are connected to the processor 2 via a plurality of first pads, a plurality of second pads, and a plurality of bonding wires.

[0020] Each of the first and second detection circuits 10 and 20 includes a plurality of magnetic detection elements. In this embodiment, the plurality of magnetic detection elements are particularly a plurality of magnetoresistive effect elements. Hereinafter, the magnetoresistive effect elements will be referred to as MR elements.

[0021] The first detection circuit 10 detects a component of the target magnetic field parallel to the X direction and generates at least one first detection signal corresponding to this component. The second detection circuit 20 detects a component of the target magnetic field parallel to the Y direction and generates at least one second detection signal corresponding to this component.

[0022] Next, the circuit configuration of the magnetic sensor 1 will be described with reference to Fig. 3. Fig. 3 is a circuit diagram showing the circuit configuration of the magnetic sensor 1.

[0023] The first detection circuit 10 includes four resistors R11, R12, R13, and R14, a power supply port V1, a ground port G1, and two output ports E11 and E12. The resistor R11 is provided between the power supply port V1 and the output port E11. The resistor R12 is provided between the output port E11 and the ground port G1. The resistor R13 is provided between the output port E12 and the ground port G1. The resistor R14 is provided between the power supply port V1 and the output port E12. A voltage or current of a predetermined magnitude is applied to the power supply port V1. The ground port G1 is connected to ground.

[0024] The second detection circuit 20 includes four resistors R21, R22, R23, and R24, a power supply port V2, a ground port G2, and two output ports E21 and E22. The resistor R21 is provided between the power supply port V2 and the output port E21. The resistor R22 is provided between the output port E21 and the ground port G2. The resistor R23 is provided between the output port E22 and the ground port G2. The resistor R24 ​​is provided between the power supply port V2 and the output port E22. A voltage or current of a predetermined magnitude is applied to the power supply port V2. The ground port G2 is connected to ground.

[0025] Next, the configuration of each of the first and second detection circuits 10, 20 will be described with reference to Figures 4 to 6. Figure 4 is a perspective view showing a portion of the first detection circuit 10. Figure 5 is a plan view showing a portion of the first detection circuit 10. Figure 6 is a plan view showing a portion of the second detection circuit 20.

[0026] The magnetic sensor 1 further includes a substrate 30. The magnetic sensor 1 is configured 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. Each of the resistor units R11 to R14 includes a plurality of MR elements 50A. Each of the resistor units R21 to R24 includes a plurality of MR elements 50B.

[0027] Each of the resistor sections R11 to R14 further includes a plurality of lower electrodes 61 and a plurality of upper electrodes 62. As shown in FIGS. 4 and 5, each of the plurality of MR elements 50A has a shape that is elongated in a direction parallel to the Y direction. Each of the plurality of lower electrodes 61 electrically connects two adjacent MR elements 50A in a direction parallel to the X direction. Each of the plurality of upper electrodes 62 is disposed on two lower electrodes 61 and electrically connects two adjacent MR elements 50A. As a result, the plurality of MR elements 50A lined up in a line in a direction parallel to the X direction are connected in series.

[0028] Each of the resistor units R11 to R14 further includes a plurality of connection electrodes (not shown). In each of the resistor units 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 a group of the plurality of MR elements 50A arranged in a row is connected in series. With this configuration, each of the resistor units R11 to R14 includes the plurality of MR elements 50A connected in series by the plurality of lower electrodes 61, the plurality of upper electrodes 62, and the plurality of connection electrodes.

[0029] The above description of the connection relationship of the plurality of MR elements 50A basically also applies to the plurality of MR elements 50B in each of the resistor units R21 to R24. As shown in Fig. 6, in each of the resistor units R21 to R24, each of the plurality of MR elements 50B has a shape that is elongated in a direction parallel to the X direction. If the plurality of MR elements 50A, X direction, and Y direction in the above description of the connection relationship of the plurality of MR elements 50A are replaced with the plurality of MR elements 50B, Y direction, and X direction, respectively, the description becomes the connection relationship of the plurality of MR elements 50B.

[0030] The magnetic sensor 1 further includes a plurality of yokes 90A and a plurality of yokes 90B, each including a magnetic layer made of a soft magnetic material. Examples of soft magnetic materials that can be used to form the magnetic layers include CoFe, CoNiFe, and NiFe.

[0031] The plurality of yokes 90A include a plurality of pairs of yokes 90A, each consisting of two yokes 90A. The two yokes 90A are arranged on both sides of one MR element 50A in a direction parallel to the X direction.

[0032] The plurality of yokes 90B includes a plurality of pairs of yokes 90B, each of which consists of two yokes 90B. The two yokes 90B are arranged on both sides of one MR element 50B in a direction parallel to the Y direction.

[0033] The magnetic sensor 1 further includes a plurality of magnetic field generators 70A and a plurality of magnetic field generators 70B. The plurality of magnetic field generators 70A include a plurality of pairs of magnetic field generators 70A, each consisting of two magnetic field generators 70A. The two magnetic field generators 70A are arranged at a predetermined interval in a direction parallel to the Y direction, sandwiching one MR element 50A and two yokes 90A adjacent to this one MR element 50A. The two magnetic field generators 70A are configured to apply a bias magnetic field to the one MR element 50A and the two yokes 90A located between them. This bias magnetic field mainly includes a component parallel to the Y direction.

[0034] The multiple magnetic field generators 70B include multiple pairs of magnetic field generators 70B, each consisting of two magnetic field generators 70B. The two magnetic field generators 70B are arranged at a predetermined interval in a direction parallel to the X direction, sandwiching one MR element 50B and two yokes 90B adjacent to this one MR element 50B. The two magnetic field generators 70B are configured to apply a bias magnetic field to the one MR element 50B and two yokes 90B located between them. This bias magnetic field mainly includes a component parallel to the X direction.

[0035] 4, each of the plurality of magnetic field generators 70A and each of the plurality of yokes 90A may be sandwiched between the lower electrode 61 and the upper electrode 62. Although not shown, each of the plurality of magnetic field generators 70B and each of the plurality of yokes 90B may be sandwiched between the lower electrode 61 and the upper electrode 62.

[0036] In this embodiment, each of the multiple MR elements 50A and the multiple MR elements 50B is a spin-valve MR element. This spin-valve MR element includes a magnetization pinned layer having a fixed magnetization direction, a free layer having a magnetization direction that can be changed depending on the direction of a target magnetic field, and a gap layer disposed between the magnetization pinned layer and the free layer. The spin-valve MR element may be a TMR (tunneling magnetoresistance) element or a GMR (giant magnetoresistance) element. In a TMR element, the gap layer is a tunnel barrier layer. In a GMR element, the gap layer is a nonmagnetic conductive layer. In a spin-valve MR element, the resistance value varies depending on the angle between the magnetization direction of the free layer and the magnetization direction of the magnetization pinned layer. When this angle is 0°, the resistance value is minimum, and when this angle is 180°, the resistance value is maximum. In each MR element, the free layer has shape anisotropy such that the easy axis of magnetization is perpendicular to the magnetization direction of the magnetization pinned layer.

[0037] The spin-valve MR element may further include an antiferromagnetic layer. The antiferromagnetic layer is made of an antiferromagnetic material and generates exchange coupling with the magnetization pinned layer to pin the magnetization direction of the magnetization pinned layer. The magnetization pinned layer may be a so-called self-pinned type pinned layer (synthetic ferri-pinned layer, SFP layer). The self-pinned type pinned layer has a synthetic ferri-structure in which a ferromagnetic layer, a non-magnetic intermediate layer, and a ferromagnetic layer are stacked, and the two ferromagnetic layers are antiferromagnetically coupled. When the magnetization pinned layer is a self-pinned type pinned layer, the antiferromagnetic layer may be omitted.

[0038] Next, the magnetization direction of the magnetization pinned layer and the direction of the bias magnetic field will be described with reference to FIG. 3. In FIG. 3, multiple solid arrows drawn to overlap the resistor units R11 to R14 and R21 to R24 respectively represent the magnetization direction of the magnetization pinned layer in each of the resistor units R11 to R14 and R21 to R24. In the example shown in FIG. 3, the direction of the main component of magnetization of the magnetization pinned layer in each of the resistor units R11 and R13 is the X direction. The direction of the main component of magnetization of the magnetization pinned layer in each of the resistor units R12 and R14 is the −X direction. The free layer in each of the resistor units R11 to R14 has shape anisotropy in which the easy axis of magnetization is parallel to the Y direction.

[0039] The direction of the main component of magnetization of the magnetization fixed layer in each of the resistor units R21 and R23 is the Y direction. The direction of the main component of magnetization of the magnetization fixed layer in each of the resistor units R22 and R24 is the -Y direction. The free layer in each of the resistor units R21 to R24 has shape anisotropy such that the direction of the easy axis of magnetization is parallel to the X direction.

[0040] 3, the arrows labeled M11, M12, M13, and M14 indicate the directions of the main components of the bias magnetic fields generated by the multiple magnetic field generators 70A at the resistor units R11, R12, R13, and R14, respectively. The direction of the main component of the bias magnetic field at the resistor units R11 and R12 is the Y direction. The direction of the main component of the bias magnetic field at the resistor units R13 and R14 is the -Y direction.

[0041] 3, the multiple white arrows drawn to overlap the resistor units R11 to R14 respectively represent the magnetization direction of the free layer in each of the resistor units R11 to R14 when no target 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 resistor units R11 and R12 is the Y direction, which is the same as the direction of the main component of the bias magnetic field in the resistor units R11 and R12. The direction of the main component of the magnetization of the free layer in each of the resistor units R13 and R14 is the -Y direction, which is the same as the direction of the main component of the bias magnetic field in the resistor units R13 and R14.

[0042] 3, the arrows labeled M21, M22, M23, and M24 indicate the directions of the main components of the bias magnetic fields generated by the multiple magnetic field generators 70B in the resistor units R21, R22, R23, and R24, respectively. The direction of the main component of the bias magnetic field in the resistor units R21 and R22 is the X direction. The direction of the main component of the bias magnetic field in the resistor units R23 and R24 is the -X direction.

[0043] 3, multiple open arrows drawn to overlap the resistor units R21 to R24 represent the magnetization direction of the free layer in each of the resistor units R21 to R24 when no target 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 resistor units R21 and R22 is the X direction, which is the same as the direction of the main component of the bias magnetic field in the resistor units R21 and R22. The direction of the main component of the magnetization of the free layer in each of the resistor units R23 and R24 is the −X direction, which is the same as the direction of the main component of the bias magnetic field in the resistor units R23 and R24.

[0044] The direction of magnetization may be the same as the direction of the main component of magnetization described above, or may be slightly deviated from the direction of the main component of magnetization. Similarly, the direction of the bias magnetic field may be the same as the direction of the main component of the bias magnetic field described above, or may be slightly deviated from the direction of the main component of the bias magnetic field. In the following description, the direction of magnetization is assumed to be the same as the direction of the main component of magnetization, and the direction of the bias magnetic field is assumed to be the same as the direction of the main component of the bias magnetic field.

[0045] Next, the operation of the first and second detection circuits 10 and 20 will be described with reference to FIG. 3. In the first detection circuit 10, the potential at the connection point between the resistors R11 and R12, i.e., the potential at the output port E11, and the potential at the connection point between the resistors R13 and R14, i.e., the potential at the output port E12, change depending on the strength of the component of the target magnetic field parallel to the X-direction. The first detection circuit 10 may generate, as first detection signals, signals corresponding to the potential at the output port E11 and the potential at the output port E12. Alternatively, the first detection circuit 10 may generate, as the first detection signal, a signal corresponding to the potential difference between the output ports E11 and E12. In this case, the first detection circuit 10 may further include a differential amplifier (differential detector) that outputs, as the first detection signal, a signal corresponding to the potential difference between the output ports E11 and E12.

[0046] In the second detection circuit 20, the potential at the connection point of the resistor units R21 and R22, i.e., the potential at the output port E21, and the potential at the connection point of the resistor units R23 and R24, i.e., the potential at the output port E22, change depending on the strength of the component of the target magnetic field parallel to the Y direction. The second detection circuit 20 may generate, as the second detection signal, a signal corresponding to the potential at the output port E21 and a signal corresponding to the potential at the output port E22. Alternatively, the second detection circuit 20 may generate, as the second detection signal, a signal corresponding to the potential difference between the output ports E21 and E22. In this case, the second detection circuit 20 may further include a differential amplifier (differential detector) that outputs, as the second detection signal, a signal corresponding to the potential difference between the output ports E21 and E22.

[0047] Next, the configuration of the plurality of MR elements 50A, the plurality of MR elements 50B, the plurality of magnetic field generators 70A, the plurality of magnetic field generators 70B, the plurality of yokes 90A, and the plurality of yokes 90B will be described in detail with reference to FIGS. 7 to 11. FIG. 7 is a plan view showing a main part of the magnetic sensor 1. FIG. 8 is a plan view showing the MR elements, yokes, magnetic field generators, and insulating layers. FIG. 9 is a cross-sectional view showing a part of the cross section indicated by line 9-9 in FIG. 7. FIG. 10 is a cross-sectional view showing a part of the cross section indicated by line 10-10 in FIG. 7. FIG. 11 is a cross-sectional view showing a part of the cross section indicated by line 11-11 in FIG. 7.

[0048] 7 to 11, a first direction D1 and a second direction D2 are defined, each of which is perpendicular to the Z direction and perpendicular to each other. In the first detection circuit 10, the first direction D1 is parallel to the Y direction, and the second direction D2 is parallel to the X direction. In the second detection circuit 20, the first direction D1 is parallel to the X direction, and the second direction D2 is parallel to the Y direction.

[0049] Hereinafter, any MR element among the plurality of MR elements 50A and the plurality of MR elements 50B will be represented by the reference symbol 50, any magnetic field generator among the plurality of magnetic field generators 70A and the plurality of magnetic field generators 70B will be represented by the reference symbol 70, and any yoke among the plurality of yokes 90A and the plurality of yokes 90B will be represented by the reference symbol 90. The magnetic sensor 1 includes at least one MR element 50. In particular, in this embodiment, the magnetic sensor 1 includes a plurality of MR elements 50 as the at least one MR element 50.

[0050] Here, focusing on one MR element 50, the configurations of the MR element 50, the magnetic field generator 70, and the yoke 90 will be described. The MR element 50 includes multiple magnetic films. The stacking direction of the multiple magnetic films is parallel to the Z direction. The multiple magnetic films include the aforementioned magnetization fixed layer 52 and free layer 54. Each of the multiple MR elements 50 further includes the aforementioned gap layer 53, buffer layer 51, and cap layer 55. As shown in FIGS. 9 and 10 , the buffer layer 51, magnetization fixed layer 52, gap layer 53, free layer 54, and cap layer 55 are stacked in this order in the Z direction. The buffer layer 51 and cap layer 55 are each formed of a nonmagnetic metal material such as Ru, Ta, Cu, or Cr.

[0051] The MR element 50 has an upper surface 50a located at an end in the Z direction, a lower surface 50b located at an end in the -Z direction, two side surfaces 50c located at both ends in the first direction D1, and two side surfaces 50d located 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 multiple magnetic films (a direction parallel to the Z direction).

[0052] The magnetic sensor 1 further includes at least one yoke 90 adjacent to the MR element 50 at a predetermined interval. In particular, in this embodiment, the magnetic sensor 1 includes two yokes 90 arranged to sandwich the MR element 50. The MR element 50 is arranged between the two yokes 90 in the second direction D2.

[0053] The magnetic sensor 1 further includes an insulating layer 32 made of an insulating material such as Al2O3 or SiO2 and arranged around the MR element 50. The two yokes 90 are embedded in the insulating layer 32. The insulating layer 32 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 is spaced apart from the MR element 50 by the thickness of the insulating layer 32 interposed between the MR element 50 and the two yokes 90.

[0054] In addition to the magnetic layer, each of the two yokes 90 may include a buffer layer interposed between the magnetic layer and the insulating layer 32, and a cap layer disposed on the magnetic layer. The buffer layer and the cap layer may be formed of a non-magnetic metal material such as Ru, Ta, Cu, or Cr.

[0055] Each of the two yokes 90 is disposed so as to ride on a side surface 50d of the MR element 50. A portion of each of the two yokes 90 overlaps a portion of the MR element 50 when viewed from the Z direction.

[0056] The magnetic sensor 1 further includes at least one magnetic field generator 70 configured to generate a bias magnetic field that is applied to the two yokes 90. In particular, in this embodiment, the magnetic sensor 1 includes two magnetic field generators 70 arranged to sandwich the MR element 50 and the two yokes 90. The MR element 50 and the two yokes 90 are arranged between the two magnetic field generators 70 in the first direction D1. An insulating layer 32 is also arranged around the two magnetic field generators 70. The bias magnetic field generated by each of the two magnetic field generators 70 is also applied to the MR element 50.

[0057] Each of the two magnetic field generators 70 is disposed so as to ride on a side surface 50c of the MR element 50. A portion of each of the two magnetic field generators 70 overlaps a portion of the MR element 50 when viewed from the Z direction. Furthermore, each of the two magnetic field generators 70 is disposed so as to ride on each of the two yokes 90. A portion of each of the two magnetic field generators 70 overlaps a portion of each of the two yokes 90 when viewed from the Z direction.

[0058] Each of the two magnetic field generators 70 includes a ferromagnetic portion 72 made of a ferromagnetic material and an antiferromagnetic portion 73 made of an antiferromagnetic material. In this embodiment, the antiferromagnetic portion 73 is disposed on the ferromagnetic portion 72.

[0059] At least a portion of each of the two magnetic field generators 70 overlaps with the MR element 50 and the two yokes 90 when viewed from the first direction D1. In this embodiment, the ferromagnetic part 72 includes a ferromagnetic layer 72a made of a ferromagnetic material. The ferromagnetic layer 72a is arranged so as to overlap with the MR element 50 and the two yokes 90 when viewed from the first direction D1. The ferromagnetic layer 72a may also be arranged so as to overlap with the entire free layer 54 when viewed from the first direction D1.

[0060] The ferromagnetic layer 72a is made of a ferromagnetic material containing one or more elements of Co, Fe, and Ni, such as CoFe, CoFeB, and CoNiFe.

[0061] The ferromagnetic portion 72 may include, instead of the ferromagnetic layer 72a, a laminate of multiple ferromagnetic layers, with adjacent layers made of different ferromagnetic materials. Examples of such a laminate include a Co layer, a CoFe layer, and a Co layer, and a Co 70 Fe 30 Layer and Co 30 Fe 70 Layer and Co 70 Fe 30 The Co 70 Fe 30 represents an alloy consisting of 70 atomic % Co and 30 atomic % Fe, and Co 30 Fe 70 represents an alloy consisting of 30 atomic % Co and 70 atomic % Fe.

[0062] The antiferromagnetic portion 73 includes an antiferromagnetic layer 73a made of an antiferromagnetic material. The antiferromagnetic layer 73a is disposed on the ferromagnetic layer 72a and is in contact with the ferromagnetic layer 72a. The antiferromagnetic layer 73a is made of an antiferromagnetic material such as IrMn or PtMn.

[0063] The ferromagnetic layer 72a has magnetization as a whole. The magnetization of the ferromagnetic layer 72a as a whole is the volume-averaged vector sum of the magnetic moments of each unit, such as an atom or crystal lattice, in the entire ferromagnetic layer 72a. Hereinafter, the magnetization of the ferromagnetic layer 72a as a whole will simply be referred to as the magnetization of the ferromagnetic layer 72a. The antiferromagnetic layer 73a is in contact with the top surface of the ferromagnetic layer 72a and is exchange-coupled with the ferromagnetic layer 72a. This determines the direction of the magnetization of the ferromagnetic layer 72a.

[0064] In this embodiment, the ferromagnetic portion 72 is substantially entirely formed of the ferromagnetic layer 72a, and the antiferromagnetic portion 73 is substantially entirely formed of the antiferromagnetic layer 73a. The antiferromagnetic layer 73a is exchange-coupled with the ferromagnetic layer 72a, thereby causing the antiferromagnetic portion 73 to be exchange-coupled with the ferromagnetic portion 72. This determines the direction of magnetization of the ferromagnetic portion 72. The direction of magnetization of the ferromagnetic portion 72 coincides with the direction of magnetization of the ferromagnetic layer 72a. The ferromagnetic portion 72 and the antiferromagnetic portion 73 generate a bias magnetic field based on the magnetization of the ferromagnetic portion 72. The magnetic field generator 70 configured in this manner has high resistance to external disturbance magnetic fields.

[0065] The two magnetic field generators 70 cooperate to apply a bias magnetic field to the MR element 50 and the two yokes 90. The magnetization direction of the ferromagnetic portion 72 of one of the two magnetic field generators 70 may be the same as the magnetization direction of the ferromagnetic portion 72 of the other of the two magnetic field generators 70. In this case, the direction of the bias magnetic field generated by one of the two magnetic field generators 70 will be the same as the direction of the bias magnetic field generated by the other of the two magnetic field generators 70.

[0066] Each of the two magnetic field generators 70 further includes a buffer layer 71 disposed on the lower surface (-Z direction side) of the ferromagnetic layer 72a and a cap layer 74 disposed on the antiferromagnetic layer 73a. The buffer layer 71 and the cap layer 74 are made of a nonmagnetic metal material such as Ru, Ta, Cu, or Cr.

[0067] The magnetic sensor 1 further includes an insulating layer 31 made of an insulating material and interposed between the substrate 30 (see FIGS. 4 to 6) and the lower electrode 61, and an insulating layer 33 made of an insulating material and interposed between the MR element 50, the two yokes 90, and the two magnetic field generators 70. The insulating layer 33 is also interposed between the two magnetic field generators 70 and the lower electrode 61. The insulating layers 31 and 33 are formed of an insulating material such as Al2O3 or SiO2.

[0068] The upper electrode 62 is disposed on the MR element 50, the two magnetic field generators 70, the two yokes 90, and the insulating layer 32. The upper surface 50a of the MR element 50, the upper surfaces of the two magnetic field generators 70, i.e., the upper surface of the cap layer 74, and the upper surfaces of the two yokes 90, are in contact with the upper electrode 62. The magnetic sensor 1 further includes an insulating layer (not shown) made of an insulating material and disposed on the upper electrode 62.

[0069] Up to this point, the configurations of the MR element 50 and the magnetic field generator 70 have been described, focusing on one MR element 50. In this embodiment, the magnetic sensor 1 includes a plurality of MR elements 50. Therefore, the magnetic sensor 1 includes a plurality of magnetic field generators 70 and a plurality of yokes 90.

[0070] Next, a method for forming the plurality of MR elements 50 according to the present embodiment will be described. In the process of forming the plurality of MR elements 50, first, a plurality of initial MR elements are formed, which will later become the plurality of MR elements 50. Each of the plurality of initial MR elements includes an initial magnetization fixed layer, which will later become the magnetization fixed layer 52, a buffer layer 51, a gap layer 53, a free layer 54, and a cap layer 55.

[0071] Next, the magnetization direction of the initial magnetization fixed layer is fixed in the predetermined direction using laser light and an external magnetic field containing a component in the predetermined direction. For example, for the initial MR elements that will later become the MR elements 50A that constitute the resistor units R11 and R13 of the first detection circuit 10, laser light is irradiated onto the initial MR elements while applying an external magnetic field in the X direction. When the irradiation of the laser light is completed, the magnetization direction of the initial magnetization fixed layer is fixed in the X direction. As a result, the initial magnetization fixed layer becomes the magnetization fixed layer 52.

[0072] Furthermore, in the initial MR elements that will later become the MR elements 50A that constitute the resistor units R12, R14 of the first detection circuit 10, the magnetization direction of the initial magnetization fixed layer of each of the initial MR elements can be fixed in the −X direction by using an external magnetic field in the −X direction. The magnetization direction of the magnetization fixed layer 52 of each of the MR elements 50B that constitute each of the resistor units R21 to R24 of the second detection circuit 20 is also fixed in the same manner as the magnetization fixed layer 52 of each of the MR elements 50A.

[0073] The MR element 50 is completed by fixing the direction of magnetization of the magnetization fixed layer 52, and then patterning the laminated film by etching so that two side surfaces 50c and two side surfaces 50d are formed in the laminated film.

[0074] Next, a method for forming a plurality of magnetic field generators 70 and a plurality of yokes 90 in this embodiment will be described. Here, focusing on one MR element 50, a method for forming two magnetic field generators 70 and two yokes 90 will be described. First, a first photoresist mask is formed on the laminated film that will later become the MR element 50. Next, using the first photoresist mask, the laminated film is patterned by etching so that two side surfaces 50d (see FIG. 11) are formed in the laminated film. Next, with the first photoresist mask remaining, an insulating layer 32 (see FIGS. 8 and 11) is formed around the laminated film. Next, the first photoresist mask is removed.

[0075] Next, a second photoresist mask is formed on the stacked film and the insulating layer 32. Next, two grooves for accommodating the two yokes 90 are formed in the insulating layer 32 using the second photoresist mask. Next, the two yokes 90 are formed in the two grooves while leaving the second photoresist mask in place. Next, the second photoresist mask is removed. Note that before forming the two yokes 90, an insulating film (not shown) may be formed in the two grooves.

[0076] Next, a third photoresist mask is formed on the laminated film, the two yokes 90, and the insulating layer 32. Next, the laminated film is patterned by etching so that two side surfaces 50c (see FIG. 9) are formed in the laminated film. This etching also etches the two yokes 90 and the insulating layer 32. By forming the two side surfaces 50c in the laminated film, the laminated film becomes the MR element 50. Next, with the third photoresist mask remaining, the insulating layer 33 and two magnetic field generators 70 are formed in this order. Next, the third photoresist mask is removed.

[0077] The process of forming the two magnetic field generators 70 includes sequentially forming a buffer layer 71, a ferromagnetic layer 72a, an antiferromagnetic layer 73a, and a cap layer 74, and fixing the magnetization direction of the ferromagnetic layer 72a. The process of fixing the magnetization direction of the ferromagnetic layer 72a will be described in detail below. The magnetization direction of the ferromagnetic layer 72a is fixed in the same manner as the magnetization fixed layer 52 of the MR element 50. That is, after first forming the cap layer 74, the magnetization direction of the ferromagnetic layer 72a is fixed in the predetermined direction using a laser beam and an external magnetic field containing a component in a predetermined direction. For example, a plurality of magnetic field generators 70 arranged near a plurality of MR elements 50A that will later constitute the resistors R11 and R12 of the first detection circuit 10 are irradiated with laser light while applying an external magnetic field in the Y direction. When the irradiation of the laser light is completed, the direction of magnetization of the ferromagnetic layer 72a of each of the plurality of magnetic field generators 70 is fixed in the Y direction.

[0078] Furthermore, for the plurality of magnetic field generators 70 arranged near the plurality of MR elements 50A that subsequently constitute the resistor portions R13, R14 of the first detection circuit 10, the magnetization direction of the ferromagnetic layer 72a of each of the plurality of magnetic field generators 70 can be fixed in the -Y direction by using an external magnetic field in the -Y direction. The magnetization direction of each of the ferromagnetic layers 72a of the plurality of magnetic field generators 70 arranged near the plurality of MR elements 50B that respectively constitute the resistor portions R21 to R24 of the second detection circuit 20 is also fixed in the same manner as above.

[0079] The intensity of the laser light used to fix the magnetization direction of the ferromagnetic layer 72a may be smaller than the intensity of the laser light used to fix the magnetization direction of the magnetization fixed layer 52. Furthermore, the intensity of the laser light used to fix the magnetization direction of the ferromagnetic layer 72a is preferably an intensity that suppresses changes in the magnetoresistance change rate, which is the ratio of magnetoresistance change to the resistance of the MR element 50.

[0080] Next, the operation and effect of the magnetic sensor 1 according to this embodiment will be described. The magnetic sensor 1 according to this embodiment includes an MR element 50 and two yokes 90 adjacent to the MR element 50 with a predetermined distance between them. Depending on the environment in which the magnetic sensor 1 is used, a strong disturbance magnetic field may be temporarily applied to the magnetic sensor 1. In this case, the two yokes 90 are magnetized in a predetermined direction according to the direction of the disturbance magnetic field. As a result, the output signal of the magnetic sensor 1 may change when no target magnetic field is applied.

[0081] In contrast, the magnetic sensor 1 according to this embodiment further includes two magnetic field generators 70 configured to generate a bias magnetic field to be applied to the two yokes 90. According to this embodiment, the bias magnetic field makes it possible to align the magnetization directions of the two yokes 90 in a predetermined direction, and it is possible to suppress changes in the output signal of the magnetic sensor 1 when no target magnetic field is applied.

[0082] In particular, in this embodiment, each of the two magnetic field generators 70 includes a ferromagnetic portion 72 and an antiferromagnetic portion 73 exchange-coupled with the ferromagnetic portion 72. The magnetic field generator 70 configured in this manner has higher resistance to disturbance magnetic fields than a magnetic body made of a hard magnetic material such as a magnet. Therefore, this embodiment can more effectively suppress changes in the output signal of the magnetic sensor 1 when no target magnetic field is applied.

[0083] [Variations] Next, first to fifth modified examples of the magnetic sensor 1 according to the present embodiment will be described. First, the first modified example will be described with reference to Fig. 12. Fig. 12 is a plan view showing a main part of the first modified example of the magnetic sensor 1.

[0084] In the first modification, two MR elements 50, three magnetic field generators 70, and four yokes 90 are arranged between a lower electrode 61 and an upper electrode 62. Here, the three magnetic field generators 70 are referred to as "first," "second," and "third" to distinguish them from one another. The first magnetic field generator 70 is arranged between two MR elements 50 aligned along the first direction D1. The second magnetic field generator 70 is arranged in a position sandwiching one of the two MR elements 50 between itself and the first magnetic field generator 70. The third magnetic field generator 70 is arranged in a position sandwiching the other of the two MR elements 50 between itself and the first magnetic field generator 70.

[0085] Two yokes 90 are arranged between the first magnetic field generator 70 and the second magnetic field generator 70. Two other yokes 90 are arranged between the first magnetic field generator 70 and the third magnetic field generator 70.

[0086] The two MR elements 50 shown in FIG. 12 are connected to the same lower electrode 61 and the same upper electrode 62. These two MR elements 50 are connected in parallel in the circuit configuration. Here, two MR elements 50 connected in parallel in the circuit configuration are referred to as an element pair. Each of the multiple lower electrodes 61 electrically connects two adjacent element pairs in the second direction D2. Each of the multiple upper electrodes 62 is disposed on two lower electrodes 61 and electrically connects two adjacent element pairs. As a result, the multiple element pairs aligned in a row in the second direction D2 are connected in series.

[0087] Next, a second modified example will be described with reference to FIG. 13. FIG. 13 is a cross-sectional view showing a main portion of the second modified example of the magnetic sensor 1. In the second modified example, an antiferromagnetic layer 73a, a ferromagnetic layer 72a, and a cap layer 74 are sequentially disposed on a buffer layer 71. In the second modified example, the antiferromagnetic layer 73a is in contact with the lower surface of the ferromagnetic layer 72a and exchange-coupled with the ferromagnetic layer 72a. This defines the direction of magnetization of the ferromagnetic layer 72a.

[0088] Next, a third modified example will be described with reference to FIG. 14. FIG. 14 is a cross-sectional view showing a main part of the third modified example of the magnetic sensor 1. In the third modified example, the antiferromagnetic part 73 includes an antiferromagnetic layer 73b in addition to an antiferromagnetic layer 73a. The antiferromagnetic layer 73b is disposed between the buffer layer 71 and the ferromagnetic layer 72a. The antiferromagnetic layer 73b is formed of an antiferromagnetic material such as IrMn or PtMn.

[0089] The antiferromagnetic layer 73b is in contact with the lower surface of the ferromagnetic layer 72a and exchange-coupled to the ferromagnetic layer 72a. As described above, the antiferromagnetic layer 73a is in contact with the upper surface of the ferromagnetic layer 72a and exchange-coupled to the ferromagnetic layer 72a. In the third modification, the antiferromagnetic layers 73a and 73b are exchange-coupled to the ferromagnetic layer 72a, thereby defining the direction of magnetization of the ferromagnetic layer 72a.

[0090] Next, a fourth modified example will be described with reference to FIG. 15. FIG. 15 is a cross-sectional view showing a main portion of the fourth modified example of the magnetic sensor 1. In the fourth modified example, the ferromagnetic part 72 includes a ferromagnetic layer 72b in addition to the ferromagnetic layer 72a. The ferromagnetic layer 72b is disposed between the buffer layer 71 and the ferromagnetic layer 72a. The ferromagnetic layer 72b is formed of a ferromagnetic material containing one or more elements of Co, Fe, and Ni. In the fourth modified example, the ferromagnetic layer 72b has a magnetization in the same direction as the magnetization of the ferromagnetic layer 72a.

[0091] In a fourth modification, the ferromagnetic layer 72a may be formed of a ferromagnetic material capable of increasing the exchange coupling energy with the antiferromagnetic layer 73a, and the ferromagnetic layer 72b may be formed of a ferromagnetic material having a higher saturation magnetic flux density than the ferromagnetic material constituting the ferromagnetic layer 72a. In this case, the exchange coupling energy between the ferromagnetic part 72 consisting of the ferromagnetic layers 72a and 72b and the antiferromagnetic layer 73a is increased, while the strength of the bias magnetic field generated by the magnetic field generator 70 can be increased and the magnetic field generator 70 can be made smaller. An example of the ferromagnetic layer 72a is Co. 70 Fe 30 An example of the ferromagnetic layer 72b is a Co layer. 30 Fe 70 layers.

[0092] Next, a fifth modified example will be described with reference to FIG. 16. FIG. 16 is a cross-sectional view showing a main portion of the fifth modified example of the magnetic sensor 1. In the fifth modified example, the ferromagnetic part 72 includes a ferromagnetic layer 72b in addition to a ferromagnetic layer 72a. The ferromagnetic layer 72b is disposed between the buffer layer 71 and the ferromagnetic layer 72a. The ferromagnetic layer 72b is made of a ferromagnetic material containing one or more elements of Co, Fe, and Ni. The ferromagnetic layers 72a and 72b may be made of the same ferromagnetic material or different ferromagnetic materials.

[0093] In the fifth modification, the magnetic field generator 70 further includes a non-magnetic layer 75 disposed between the ferromagnetic layers 72 a and 72 b. The non-magnetic layer 75 is made of a non-magnetic metal material such as Ru.

[0094] In the fifth modification, the ferromagnetic layers 72a and 72b are ferromagnetically exchange-coupled via a nonmagnetic layer 75 so that their magnetizations are in the same direction. The ferromagnetic layers 72a and 72b have magnetizations in the same direction. The thickness of the nonmagnetic layer 75 is set so as not to eliminate the exchange coupling between the ferromagnetic layers 72a and 72b.

[0095] [Second embodiment] Next, a second embodiment of the present invention will be described with reference to Figs. 17 to 20. Fig. 17 is a plan view showing a main part of a magnetic sensor according to this embodiment. Fig. 18 is a cross-sectional view showing a part of a cross section taken along line 18-18 in Fig. 17. Fig. 19 is a cross-sectional view showing a part of a cross section taken along line 19-19 in Fig. 17. Fig. 20 is a cross-sectional view showing a part of a cross section taken along line 20-20 in Fig. 17.

[0096] The magnetic sensor 1 according to the present embodiment includes a plurality of magnetic field generators 700 instead of the plurality of magnetic field generators 70 in the first embodiment. The functions of the plurality of magnetic field generators 700 and the positional relationship of the plurality of magnetic field generators 700 with respect to the plurality of MR elements 50 and the plurality of yokes 90 are the same as those in the first embodiment.

[0097] The configuration of the magnetic field generator 700 will be described below, focusing on one MR element 50. The magnetic sensor 1 according to this embodiment includes two magnetic field generators 700 arranged to sandwich the MR element 50 and two yokes 90. Each of the two magnetic field generators 700 includes a ferromagnetic portion 712 made of a ferromagnetic material.

[0098] The ferromagnetic part 712 includes a ferromagnetic layer 712a made of a ferromagnetic material. The ferromagnetic layer 712a is arranged to overlap the MR element 50 and the two yokes 90 when viewed from the first direction D1. In particular, in this embodiment, the ferromagnetic layer 712a is arranged to overlap the entire free layer 54 when viewed from the first direction D1. The MR element 50 is arranged between the two ferromagnetic layers 712a arranged at a predetermined interval in the first direction D1. The ferromagnetic layer 712a may be formed of, for example, the same material as the ferromagnetic layer 72a in the first embodiment.

[0099] Each of the two magnetic field generators 700 further includes a buffer layer 711 disposed on the lower surface side of the ferromagnetic portion 712. The buffer layer 711 may be formed of, for example, the same material as the buffer layer 71 in the first embodiment.

[0100] The magnetic sensor 1 according to this embodiment further includes an underlayer 713 disposed on the MR element 50, the two ferromagnetic layers 712a, the two yokes 90, and the insulating layer 32, an antiferromagnetic layer 714 disposed on the underlayer 713, and a cap layer 715 disposed on the antiferromagnetic layer 714. The antiferromagnetic layer 714 includes two facing portions 714a that face the two ferromagnetic layers 712a via the underlayer 713, and a non-facing portion 714b that faces the MR element 50, the two yokes 90, and the insulating layer 32 via the underlayer 713 but does not face the two ferromagnetic layers 712a. The two facing portions 714a are connected to each other by the non-facing portion 714b.

[0101] The underlayer 713 includes two intermediate portions 713a interposed between the two ferromagnetic layers 712a and the two opposing portions 714a, and the cap layer 715 includes two protective portions 715a disposed on the two opposing portions 714a.

[0102] The underlayer 713 is formed of a metal material. In particular, in this embodiment, the underlayer 713 is formed of a ferromagnetic metal material. When the underlayer 713 is formed of a ferromagnetic metal material, the underlayer 713 may be formed of the same material as the ferromagnetic layer 712a. At least the intervening portion 713a of the underlayer 713 may be magnetic. Portions of the underlayer 713 that are intervening between the MR element 50, the two yokes 90, and the insulating layer 32 and the antiferromagnetic layer 714 may or may not be magnetic.

[0103] The antiferromagnetic layer 714 may be made of, for example, the same material as the antiferromagnetic layer 73a in the first embodiment. The cap layer 715 may be made of, for example, the same material as the cap layer 74 in the first embodiment.

[0104] The buffer layer 711 and the ferromagnetic layer 712a constitute a first stacked structure 701. The underlayer 713, the antiferromagnetic layer 714, and the cap layer 715 constitute a second stacked structure 702. The MR element 50 is disposed between the two first stacked structures 701. The second stacked structure 702 is disposed on the MR element 50, the two yokes 90, the insulating layer 32, and the two first stacked structures 701.

[0105] The second laminate 702 includes two laminate portions 702a disposed on the two first laminate portions 701. Each of the two laminate portions 702a includes an intervening portion 713a, an opposing portion 714a, and a protective portion 715a.

[0106] In a stack consisting of the first stack 701 and the stack portion 702a disposed on the first stack 701, the facing portion 714a is exchange-coupled with the ferromagnetic layer 712a, thereby defining the direction of magnetization of the ferromagnetic layer 712a.

[0107] Each of the two magnetic field generators 700 further includes an antiferromagnetic portion made of an antiferromagnetic material. In this embodiment, the antiferromagnetic portion is substantially entirely formed by the facing portion 714a. Furthermore, in this embodiment, the ferromagnetic portion 712 is substantially entirely formed by the ferromagnetic layer 712a. The facing portion 714a is exchange-coupled with the ferromagnetic layer 712a, thereby causing the antiferromagnetic portion to be exchange-coupled with the ferromagnetic portion 712. This defines the direction of magnetization of the ferromagnetic portion 712. The direction of magnetization of the ferromagnetic portion 712 coincides with the direction of magnetization of the ferromagnetic layer 712a. The ferromagnetic portion 712 and the antiferromagnetic portion generate a bias magnetic field based on the magnetization of the ferromagnetic portion 712. The bias magnetic field is applied to the MR element 50 and the two yokes 90.

[0108] Since the ferromagnetic layer 712a is part of the first laminate 701 and the facing portion 714a is part of the laminate portion 702a, it can be said that the first laminate 701 and the laminate portion 702a constitute the magnetic field generator 700. The magnetic field generator 700 includes a buffer layer 711, a ferromagnetic layer 712a, an intervening portion 713a, a facing portion 714a, and a protective portion 715a.

[0109] The MR element 50 and the two yokes 90 are disposed between two magnetic field generators 700. The two magnetic field generators 700 cooperate to apply a bias magnetic field to the MR element 50 and the two yokes 90. The magnetization direction of the ferromagnetic layer 712 a of one of the two magnetic field generators 700 may be the same as the magnetization direction of the ferromagnetic layer 712 a of the other of the two magnetic field generators 700. In this case, the direction of the bias magnetic field generated by one of the two magnetic field generators 700 will be the same as the direction of the bias magnetic field generated by the other of the two magnetic field generators 700.

[0110] When the underlayer 713 is made of the same material as the ferromagnetic layer 712a, the ferromagnetic layer 712a and the intermediate portion 713a essentially form a single ferromagnetic layer. The facing portion 714a contacts the top surface of the single ferromagnetic layer and is exchange-coupled to the single ferromagnetic layer.

[0111] The maximum dimension of the ferromagnetic layer 712a in the stacking direction of the multiple magnetic films (direction parallel to the Z direction) is larger than the maximum dimension in the stacking direction of the underlayer 713. Also, the maximum dimension of the free layer 54 in the stacking direction is larger than the maximum dimension in the stacking direction of the underlayer 713.

[0112] The top surface 50a of the MR element 50 and the top surfaces of the two yokes 90 face the non-facing portions 714b of the antiferromagnetic layer 714. The distance between the non-facing portions 714b and the bottom surface 50b of the MR element 50 is greater than the distance between the top surface 50a and the bottom surface 50b. The distance between the facing portions 714a of the antiferromagnetic layer 714 and the top surface of the lower electrode 61 may be the same as the distance between the non-facing portions 714b and the bottom surface 50b, or may be different from the distance between the non-facing portions 714b and the bottom surface 50b. In the latter case, the maximum distance between the facing portions 714a and the top surface of the lower electrode 61 may be greater or smaller than the distance between the non-facing portions 714b and the bottom surface 50b.

[0113] In this embodiment, the insulating layer 33 is interposed between the MR element 50, the two yokes 90, and the two first laminates 701.

[0114] The upper surface of the second stacked body 702, i.e., the upper surface of the cap layer 715, 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, or 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.

[0115] Up to this point, the configuration of the magnetic field generator 700 has been described, focusing on one MR element 50. In this embodiment, the magnetic sensor 1 includes a plurality of MR elements 50. As shown in FIG. 17 , the plurality of MR elements 50 includes two MR elements 50 aligned along the second direction D2. A second laminate 702 is interposed between the two MR elements 50 and the upper electrode 62 that electrically connects the two MR elements 50. In the example shown in FIG. 17 , the second laminate 702 is disposed on the two MR elements 50, four yokes 90, and four first laminates 701. In this example, the second laminate 702 includes four laminate portions 702a.

[0116] The two MR elements 50 are also electrically connected by the antiferromagnetic layer 714 of the second stack 702. The two MR elements 50 are also connected in series by the antiferromagnetic layer 714.

[0117] In addition, in this embodiment, since the magnetic sensor 1 has multiple MR elements 50 and multiple magnetic field generators 700, the magnetic sensor 1 has multiple underlayers 713, multiple antiferromagnetic layers 714, and multiple cap layers 715.

[0118] Next, a method for forming the magnetic field generator 700 in this embodiment will be briefly described. Here, two magnetic field generators 700 will be described, focusing on one MR element 50. As in the first embodiment, after forming two yokes 90, a photoresist mask is formed on the laminated film that will later become the MR element 50, the two yokes 90, and the insulating layer 32. Next, using the photoresist mask, the laminated film is patterned by etching so that two side surfaces 50c are formed in the laminated film. This etching also etches the two yokes 90 and the insulating layer 32. With the two side surfaces 50c formed in the laminated film, the laminated film becomes the MR element 50. Next, with the photoresist mask remaining, the insulating layer 33, buffer layer 711, and ferromagnetic layer 712a are formed in this order.

[0119] Next, the photoresist mask is removed. Next, an underlayer 713, an antiferromagnetic layer 714, and a cap layer 715 are formed in this order on the MR element 50, the two yokes 90, the ferromagnetic layer 712a, and the insulating layer 32. Next, a step of fixing the magnetization direction of the ferromagnetic layer 712a is performed. The step of fixing the magnetization direction of the ferromagnetic layer 712a is the same as the step of fixing the magnetization direction of the ferromagnetic layer 72a in the first embodiment. By fixing the magnetization direction of the ferromagnetic layer 712a, the magnetic field generator 700 is completed.

[0120] The ferromagnetic part 712 of the magnetic field generator 700 in this embodiment may include two ferromagnetic layers, as in the fourth and fifth modifications of the first embodiment. When the ferromagnetic part 712 includes two ferromagnetic layers, the magnetic field generator 700 may include a non-magnetic layer disposed between the two ferromagnetic layers, as in the fifth modification of the first embodiment.

[0121] Furthermore, the antiferromagnetic portion of the magnetic field generator 700 in this embodiment may include, in addition to the opposing portion 714a, an antiferromagnetic layer arranged between the buffer layer 711 and the ferromagnetic layer 712a, as in the third modified example of the first embodiment.

[0122] Other configurations, actions, and effects of this embodiment are the same as those of the first embodiment.

[0123] [Variations] Next, first to third modified examples of the magnetic sensor 1 according to the present embodiment will be described. First, the first modified example will be described with reference to Fig. 21. Fig. 21 is a plan view showing a main part of the first modified example of the magnetic sensor 1.

[0124] In the first modification, 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 on two lower electrodes 61 and electrically connects two adjacent MR elements 50. This connects the plurality of MR elements 50 lined up in a row in the first direction D1 in series. In the first modification, the plurality of connecting electrodes electrically connects the plurality of lower electrodes 61 or the plurality of upper electrodes 62 so that a group of the plurality of MR elements 50 lined up in a row is connected in series.

[0125] In the first modification, a second stacked body 702 is interposed between the two MR elements 50 aligned in the first direction D1 and the upper electrode 62. The two MR elements 50 are also electrically connected by an antiferromagnetic layer 714 (see FIGS. 18 to 20) of the second stacked body 702. The two MR elements 50 are also connected in series by the antiferromagnetic layer 714.

[0126] Next, a second modified example will be described with reference to FIG. 22. FIG. 22 is a cross-sectional view showing a main part of the second modified example of the magnetic sensor 1. In the second modified example, the first laminate 701 includes a ferromagnetic part 721A made of a ferromagnetic material instead of the ferromagnetic layer 712a. The ferromagnetic part 721A has the same function as the ferromagnetic part 712. The shape and arrangement of the ferromagnetic part 721A may be the same as the shape and arrangement of the ferromagnetic layer 712a.

[0127] The second laminate 702 includes an underlying portion 721B instead of the underlying layer 713. The shape and arrangement of the underlying portion 721B may be the same as those of the underlying layer 713. The underlying portion 721B also includes an intermediate portion 721Ba interposed between the ferromagnetic portion 721A and the facing portion 714a, and a non-interposed portion 721Bb other than the intermediate portion 721Ba. The laminate portion 702a includes the intermediate portion 721Ba instead of the intermediate portion 713a.

[0128] In particular, in the second modified example, the ferromagnetic portion 721A and the underlying portion 721B are configured by one ferromagnetic layer 721. In Fig. 22, the boundary between the ferromagnetic portion 721A and the underlying portion 721B is indicated by a dashed line.

[0129] Next, a third modified example will be described with reference to Fig. 23. Fig. 23 is a cross-sectional view showing a main part of the third modified example of the magnetic sensor 1. In the third modified example, the underlayer 713 is not provided, and the antiferromagnetic layer 714 is disposed on the MR element 50, the two yokes 90, the two ferromagnetic layers 712a, and the insulating layer 32.

[0130] [Third embodiment] Next, a third embodiment of the present invention will be described with reference to Fig. 24 to Fig. 26. Fig. 24 is a plan view showing a main part of a magnetic sensor according to this embodiment. Fig. 25 is a cross-sectional view showing a part of a cross section indicated by line 25-25 in Fig. 24. Fig. 26 is a cross-sectional view showing a part of a cross section indicated by line 26-26 in Fig. 24.

[0131] Hereinafter, the differences in the configuration of the magnetic sensor 1 according to this embodiment from the first embodiment will be described, focusing on one MR element 50. In this embodiment, each of the two magnetic field generators 70 is disposed at a predetermined interval from the MR element 50. When viewed from the Z direction, each of the two magnetic field generators 70 does not overlap with the MR element 50.

[0132] In this embodiment, each of the two magnetic field generators 70 is disposed at a predetermined interval from the two yokes 90. When viewed from the Z direction, each of the two magnetic field generators 70 does not overlap with the two yokes 90.

[0133] In this embodiment, the insulating layer 33 is interposed between the magnetic field generator 70 and the lower electrode 61 and insulating layer 32. The magnetic sensor 1 according to this embodiment includes an insulating layer 34 made of an insulating material such as Al2O3 or SiO2 and interposed between the two yokes 90 and the lower electrode 61 and insulating layer 32.

[0134] Other configurations, actions, and effects of this embodiment are the same as those of the first embodiment.

[0135] [Fourth embodiment] Next, a fourth embodiment of the present invention will be described with reference to Fig. 27 to Fig. 29. Fig. 27 is a plan view showing a main part of a magnetic sensor according to this embodiment. Fig. 28 is a cross-sectional view showing a part of a cross section taken along line 28-28 in Fig. 27. Fig. 29 is a cross-sectional view showing a part of a cross section taken along line 29-29 in Fig. 27.

[0136] Hereinafter, the differences in the configuration of the magnetic sensor 1 according to this embodiment from the second embodiment will be described, focusing on one MR element 50. In this embodiment, each of the two magnetic field generators 700 is disposed at a predetermined distance from the MR element 50. Therefore, the ferromagnetic layer 712a of each of the two magnetic field generators 700 is disposed at a predetermined distance from the MR element 50. When viewed from the Z direction, each of the two magnetic field generators 700 does not overlap with the MR element 50.

[0137] Furthermore, each of the two magnetic field generators 700 is disposed at a predetermined distance from the two yokes 90. Therefore, the ferromagnetic layer 712a of each of the two magnetic field generators 700 is disposed at a predetermined distance from the two yokes 90. When viewed from the Z direction, each of the two magnetic field generators 700 does not overlap with the two yokes 90.

[0138] In this embodiment, the insulating layer 33 is interposed between the ferromagnetic layer 712a and the lower electrode 61 and insulating layer 32. The magnetic sensor 1 further includes an insulating layer 35 made of an insulating material such as Al2O3 or SiO2 and interposed between the two yokes 90 and the lower electrode 61 and insulating layer 32.

[0139] Other configurations, actions, and effects of this embodiment are the same as those of the second embodiment.

[0140] [Fifth embodiment] Next, a fifth embodiment of the present invention will be described. First, the configuration of a magnetic sensor system including a magnetic sensor according to this embodiment will be described with reference to Fig. 30. Fig. 30 is a perspective view showing a magnetic sensor system 200 according to this embodiment.

[0141] The magnetic sensor system 200 includes a magnetic sensor 201 according to 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 so that a partial magnetic field, which is a part of the magnetic field that it generates, is applied to the magnetic sensor 201. This partial magnetic field includes a first magnetic field component Hz parallel to the Z direction and a second magnetic field component Hy parallel to the Y direction.

[0142] 30, in this 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. The direction of the first magnetic field component Hz becomes the Z direction when the magnetic field generating unit 202 moves in the Y direction from a predetermined position, and becomes the -Z direction when the magnetic field generating unit 202 moves in the -Y direction from a predetermined position.

[0143] Next, a schematic configuration of the magnetic sensor 201 according to this embodiment will be described with reference to Fig. 31. Fig. 31 is a circuit diagram showing the circuit configuration of the magnetic sensor 201.

[0144] The magnetic sensor 201 includes four resistors R31, R32, R33, and R34, a power supply port V3, a ground port G3, and two output ports E31 and E32. The resistor R31 is provided between the power supply port V3 and the output port E31. The resistor R32 is provided between the output port E31 and the ground port G3. The resistor R33 is provided between the output port E32 and the ground port G3. The resistor R34 is provided between the power supply port V3 and the output port E32. A voltage or current of a predetermined magnitude is applied to the power supply port V3. The ground port G3 is connected to ground.

[0145] Each of the resistor units R31 to R34 includes a plurality of MR elements 50. The configuration of the plurality of MR elements 50 is the same as that of the first embodiment. That is, each of the plurality of MR elements 50 includes a buffer layer 51, a magnetization fixed layer 52, a gap layer 53, a free layer 54, and a cap layer 55, as shown in FIGS. 9 and 11 in the first embodiment.

[0146] 31, a plurality of solid arrows drawn to overlap the resistor units R31 to R34 respectively represent the magnetization direction of the magnetization fixed layer 52 in each of the resistor units R31 to R34. In the example shown in FIG. 31, the direction of the main component of the magnetization of the magnetization fixed layer 52 in each of the resistor units R31 and R34 is the X direction. The direction of the main component of the magnetization of the magnetization fixed layer 52 in each of the resistor units R32 and R33 is the −X direction. The free layer 54 in each of the resistor units R31 to R34 has shape anisotropy in which the direction of the easy axis of magnetization is parallel to the Y direction.

[0147] The magnetic sensor 201 further includes a plurality of magnetic field generators 70. The configuration of the plurality of magnetic field generators 70 is the same as that of the first embodiment. The plurality of magnetic field generators 70 are shown in Figs. 32 and 33, which will be described later.

[0148] The plurality of magnetic field generators 70 includes a plurality of pairs of magnetic field generators 70, each consisting of two magnetic field generators 70. The two magnetic field generators 70 are arranged at a predetermined interval in a direction parallel to the Y direction, sandwiching one MR element 50 therebetween. The two magnetic field generators 70 are configured to apply a bias magnetic field to the one MR element 50 located between them. This bias magnetic field contains a component parallel to the Y direction as its main component.

[0149] 31, the arrows labeled M31, M32, M33, and M34 indicate the directions of the main components of the bias magnetic fields generated by the multiple magnetic field generators 70 in the resistor units R31, R32, R33, and R34, respectively. The direction of the main component of the bias magnetic field in the resistor units R31 and R34 is the Y direction. The direction of the main component of the bias magnetic field in the resistor units R32 and R33 is the -Y direction.

[0150] 31, multiple open arrows drawn to overlap the resistor units R31 to R34 respectively represent the magnetization direction of the free layer in each of the resistor units R31 to R34 when no partial magnetic field is applied to the magnetic sensor 201. The direction of the main component of the magnetization of the free layer in each of the resistor units R31 and R34 is the Y direction, which is the same as the direction of the main component of the bias magnetic field in the resistor units R31 and R34. The direction of the main component of the magnetization of the free layer in each of the resistor units R32 and R33 is the -Y direction, which is the same as the direction of the main component of the bias magnetic field in the resistor units R32 and R33.

[0151] Next, the configuration of magnetic sensor 201 will be specifically described with reference to Fig. 32 to Fig. 34. Fig. 32 is a perspective view showing a portion of magnetic sensor 201. Fig. 33 is a plan view showing a portion of magnetic sensor 201. Fig. 34 is a side view showing a portion of magnetic sensor 201.

[0152] The magnetic sensor 201 further includes a substrate 230. The magnetic sensor 201 is configured by forming a plurality of components other than the substrate 230 on the substrate 230.

[0153] The magnetic sensor 201 further includes at least one yoke made of a soft magnetic material. When viewed from the Z direction, the at least one yoke has a shape that is elongated in the Y direction. The at least one yoke generates a magnetic field component parallel to the X direction based on the first magnetic field component Hz shown in FIG.

[0154] As shown in FIGS. 32 to 34 , in this embodiment, magnetic sensor 201 includes, as at least one yoke, a plurality of yokes 250 arranged side by side in the X direction. Each of the plurality of yokes 250 has, for example, a rectangular parallelepiped shape that is long in the Y direction. The plurality of yokes 250 have the same shape. Each of the plurality of yokes 250 has a first end face 250a and a second end face 250b located at both ends in a direction parallel to the X direction. In each of the plurality of yokes 250, first end face 250a is located at the end in the −X direction, and second end face 250b is located at the end in the X direction.

[0155] Each of the multiple MR elements 50 is disposed at a position where a magnetic field component generated by the multiple yokes 250 is applied. In particular, in this embodiment, each of the MR elements 50 is disposed near the end of each of the multiple yokes 250 in the -Z direction. The multiple MR elements 50 are also disposed so that multiple elements are lined up along the first end face 250a or the second end face 250b of each of the multiple yokes 250. Hereinafter, of the multiple MR elements 50, the multiple MR elements lined up along the first end face 250a will be denoted by reference symbol 50C, and the multiple MR elements lined up along the second end face 250b will be denoted by reference symbol 50D. The direction of the magnetic field component received by the multiple MR elements 50C and the direction of the magnetic field component received by the multiple MR elements 50D are opposite to each other.

[0156] When viewed from the Z direction, the multiple MR elements 50C and the multiple MR elements 50D may or may not overlap with the multiple yokes 250. In the examples shown in Figures 32 to 34, the multiple MR elements 50C and the multiple MR elements 50D are arranged so as not to overlap with the multiple yokes 250 when viewed from the Z direction.

[0157] As described above, the magnetic sensor 201 includes a plurality of magnetic field generators 70. As shown in Fig. 32 and Fig. 33, of the plurality of magnetic field generators 70, the plurality of magnetic field generators arranged to sandwich the MR element 50C are denoted by reference numeral 70C, and the plurality of magnetic field generators arranged to sandwich the MR element 50D are denoted by reference numeral 70D.

[0158] The magnetic sensor 201 further includes a plurality of yokes 90. The configuration of the plurality of yokes 90 is the same as that of the first embodiment. As shown in Fig. 32 and Fig. 33, of the plurality of yokes 90, the plurality of yokes arranged to sandwich the MR element 50C are denoted by reference numeral 90C, and the plurality of yokes arranged to sandwich the MR element 50D are denoted by reference numeral 90D.

[0159] The plurality of yokes 90C have a function of guiding the magnetic field components generated by the plurality of yokes 250 to the plurality of MR elements 50C. The plurality of yokes 90D have a function of guiding the magnetic field components generated by the plurality of yokes 250 to the plurality of MR elements 50D.

[0160] The magnetic sensor 201 further includes a wiring section 211 that electrically connects the plurality of MR elements 50C and a wiring section 212 that electrically connects the plurality of MR elements 50D. Each of the wiring sections 211 and 212 is configured with the plurality of lower electrodes 61, the plurality of upper electrodes 62, and the plurality of connection electrodes described in the first embodiment.

[0161] The wiring section 211 includes a first wiring that electrically connects the plurality of MR elements 50C whose magnetization fixed layer 52 has a main component of magnetization oriented in the X direction, and a second wiring that electrically connects the plurality of MR elements 50C whose magnetization fixed layer 52 has a main component of magnetization oriented in the −X direction. The resistor section R31 is composed of the plurality of MR elements 50C electrically connected by the first wiring. The resistor section R32 is composed of the plurality of MR elements 50C electrically connected by the second wiring.

[0162] The wiring section 212 includes a third wiring that electrically connects the plurality of MR elements 50D, each of which has a magnetization pinned layer 52 whose main component of magnetization is oriented in the −X direction, and a fourth wiring that electrically connects the plurality of MR elements 50D, each of which has a magnetization pinned layer 52 whose main component of magnetization is oriented in the X direction. The resistor section R33 is composed of the plurality of MR elements 50D electrically connected by the third wiring. The resistor section R34 is composed of the plurality of MR elements 50D electrically connected by the fourth wiring.

[0163] Next, we will explain the operation of the magnetic sensor 201. When the first magnetic field component Hz is not present, and as a result, when the magnetic field components generated by the plurality of yokes 250 are not present, the magnetization direction of the free layer 54 of each of the plurality of MR elements 50C and the plurality of MR elements 50D is parallel to the Y direction.

[0164] 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 multiple MR elements 50C constituting the resistor units R31 and R32 is the X direction, and the direction of the magnetic field component received by each of the multiple MR elements 50D constituting the resistor units R33 and R34 is the −X direction. In this case, the magnetization direction of the free layer 54 of each of the multiple MR elements 50C tilts from a direction parallel to the Y direction toward the X direction, and the magnetization direction of the free layer 54 of each of the multiple MR elements 50D tilts from a direction parallel to the Y direction toward the −X direction. As a result, compared to a state in which no magnetic field component is present, the resistance value of each of the multiple MR elements 50C constituting the resistor unit R31 and the resistance value of each of the multiple MR elements 50D constituting the resistor unit R33 decreases, and the resistance value of each of the multiple MR elements 50C constituting the resistor unit R32 and the resistance value of each of the multiple MR elements 50D constituting the resistor unit R34 increases. As a result, the resistance values ​​of the resistors R31 and R33 decrease, and the resistance values ​​of the resistors R32 and R34 increase.

[0165] 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 resistor portions R31 to R34 are opposite to when the direction of the first magnetic field component Hz is the Z direction.

[0166] The amount of change in the resistance value of each of the resistor units R31 to R34 depends on the strength of the magnetic field component that each of the MR elements 50C and 50D receives. As the strength of the magnetic field component increases, the resistance value of each of the resistor units R31 to R34 changes in a direction that increases the amount of increase or decrease, respectively. As the strength of the magnetic field component decreases, the resistance value of each of the resistor units R31 to R34 changes in a direction that decreases the amount of increase or decrease, respectively. The strength of the magnetic field component depends on the strength of the first magnetic field component Hz.

[0167] In this way, when the direction and intensity of the first magnetic field component Hz change, the resistance values ​​of the resistors R31 to R34 change such that the resistance values ​​of the resistors R31 and R33 increase while the resistance values ​​of the resistors R32 and R34 decrease, or the resistance values ​​of the resistors R31 and R33 decrease while the resistance values ​​of the resistors R32 and R34 increase. This causes a change in the potential at the connection point between the resistors R31 and R32, i.e., the potential at the output port E31, and the potential at the connection point between the resistors R33 and R34, i.e., the potential at the output port E32. The magnetic sensor 201 may generate, as detection signals, a signal corresponding to the potential at the output port E31 and a signal corresponding to the potential at the output port E32. Alternatively, the magnetic sensor 201 may generate, as detection signals, a signal corresponding to the potential difference between the output ports E31 and E32. In this case, the magnetic sensor 201 may further include a differential amplifier (difference detector) that outputs a signal corresponding to the potential difference between the output ports E31 and E32 as a detection signal.

[0168] 1 and 2 in the first embodiment. The processor 2 may be configured to receive one 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 FIG. 30).

[0169] The magnetic sensor 201 according to the present embodiment may include the plurality of magnetic field generators 700 of the second embodiment instead of the plurality of magnetic field generators 70. Other configurations, actions, and effects of the present embodiment are the same as those of the first or second embodiment.

[0170] The present invention is not limited to the above-described embodiments and may be modified in various ways. For example, the magnetic sensor of the present invention may be a magnetic sensor including the first and second detection circuits 10 and 20 of the first embodiment and the magnetic sensor 201 of the fifth embodiment as a third detection circuit. In this magnetic sensor, the third detection circuit (magnetic sensor 201) may be configured to detect a component of the target magnetic field in a direction parallel to the Z direction. This magnetic sensor may also be a geomagnetic sensor in which the target magnetic field is the geomagnetism.

[0171] Alternatively, the MR element 50 may be configured by laminating 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.

[0172] Furthermore, one MR element 50 and two yokes 90 adjacent to this one MR element 50 may be arranged between two first magnetic field generators and two second magnetic field generators in the first direction D1. The two first magnetic field generators are arranged at a predetermined interval in the second direction D2. Similarly, the two second magnetic field generators are arranged at a predetermined interval in the second direction D2. When viewed from the first direction D1, the two first magnetic field generators overlap with the two yokes 90, respectively. Similarly, when viewed from the first direction D1, the two second magnetic field generators overlap with the two yokes 90, respectively. The two first magnetic field generators and the two second magnetic field generators may or may not overlap with the MR element 50 when viewed from the first direction D1.

[0173] As described above, the magnetic sensor of the present invention comprises a magnetoresistive element, at least one yoke including a magnetic layer made of a soft magnetic material and adjacent to the magnetoresistive element with a predetermined gap therebetween, and at least one magnetic field generator including a ferromagnetic portion made of a ferromagnetic material and an antiferromagnetic portion made of an antiferromagnetic material and exchange-coupled with the ferromagnetic portion, and configured to generate a magnetic field applied to the at least one yoke.

[0174] In the magnetic sensor of the present invention, the at least one magnetic field generator may be two magnetic field generators, and the magnetoresistive element and the at least one yoke may be disposed between the two magnetic field generators.

[0175] In the magnetic sensor of the present invention, the at least one yoke may be two yokes, and the magnetoresistive element may be disposed between the two yokes.

[0176] In the magnetic sensor of the present invention, the magnetic field generated by at least one magnetic field generator may be applied to the magnetoresistive element.

[0177] In addition, in the magnetic sensor of the present invention, a portion of at least one magnetic field generator may overlap at least one yoke when viewed from an orthogonal direction perpendicular to the direction in which the magnetoresistive effect element and at least one yoke are arranged.

[0178] In the magnetic sensor of the present invention, the ferromagnetic portion may include a ferromagnetic layer made of a ferromagnetic material and arranged so that a part of the ferromagnetic layer overlaps with the at least one yoke when viewed from a direction perpendicular to the direction in which the magnetoresistive element and the at least one yoke are arranged. The antiferromagnetic portion may include an antiferromagnetic layer made of an antiferromagnetic material and in contact with the ferromagnetic layer.

[0179] In the magnetic sensor of the present invention, the ferromagnetic portion may include a ferromagnetic layer made of a ferromagnetic material and arranged so that a part of the ferromagnetic layer overlaps with at least one yoke when viewed from a direction perpendicular to the direction in which the magnetoresistive element and the at least one yoke are arranged. anti The magnetic sensor may be made of a ferromagnetic material and may include an antiferromagnetic layer disposed on the magnetoresistive element, at least one yoke, and the ferromagnetic layer. The antiferromagnetic layer may include a facing portion facing the ferromagnetic layer and a non-facing portion facing the magnetoresistive element and the at least one yoke but not facing the ferromagnetic layer. The antiferromagnetic portion may include a facing portion. The magnetic sensor may further include an underlayer interposed between the ferromagnetic layer and the antiferromagnetic layer.

[0180] The magnetic sensor of the present invention may further include a lower electrode and an upper electrode, each made of a conductive material. The magnetoresistive element may be disposed on the lower electrode. The upper electrode may be disposed on the magnetoresistive element, at least one yoke, and at least one magnetic field generator.

[0181] In the magnetic sensor of the present invention, the magnetoresistive element may include a plurality of stacked magnetic films. A portion of at least one magnetic field generator may overlap a portion of at least one yoke when viewed in the stacking direction of the plurality of magnetic films. Alternatively, at least one magnetic field generator may not overlap at least one yoke when viewed in the stacking direction of the plurality of magnetic films.

[0182] The magnetic sensor of the present invention may further include a plurality of resistive units each including a magnetoresistive element. The at least one yoke may be a plurality of yokes. The at least one magnetic field generator may be a plurality of magnetic field generators. Each of the plurality of yokes may be adjacent to the magnetoresistive element of one of the plurality of resistive units. Each of the plurality of magnetic field generators may be configured so that a magnetic field is applied to one of the plurality of yokes. The plurality of magnetic field generators may include a first specific magnetic field generator whose magnetic field direction is a first direction and a second specific magnetic field generator whose magnetic field direction is a second direction. [Explanation of symbols]

[0183] 1...magnetic sensor, 2...processor, 10...first detection circuit, 20...second detection circuit, 30...substrate, 31-33...insulating layer, 50, 50A, 50B...MR element, 51...buffer layer, 52...magnetization fixed layer, 53...gap layer, 54...free layer, 55...cap layer, 61...lower electrode, 62...upper electrode, 70, 70A, 70B...magnetic field generator, 71...buffer layer, 72...ferromagnetic portion, 7 2a, 72b...ferromagnetic layer, 73...antiferromagnetic portion, 73a, 73b...antiferromagnetic layer, 74...cap layer, 75...non-magnetic layer, 90, 90A, 90B...yoke, 100...magnetic sensor device, D1...first direction, D2...second direction, E11, E12, E21, E22...output port, G1, G2...ground port, R11 to R14, R21 to R24...resistance portion, V1, V2...power supply port.

Claims

1. a magnetoresistive element; at least one yoke including a magnetic layer made of a soft magnetic material and adjacent to the magnetoresistive element with a predetermined gap therebetween; a magnetic sensor comprising at least one magnetic field generator configured to generate a magnetic field to be applied to the at least one yoke, the magnetic field generator including a ferromagnetic portion made of a ferromagnetic material and an antiferromagnetic portion made of an antiferromagnetic material and exchange-coupled with the ferromagnetic portion, the ferromagnetic portion includes a ferromagnetic layer made of a ferromagnetic material and arranged so that a portion of the ferromagnetic layer overlaps with the at least one yoke when viewed in a direction perpendicular to a direction in which the magnetoresistive element and the at least one yoke are arranged, the magnetic sensor further comprises an antiferromagnetic layer made of an antiferromagnetic material and disposed on the magnetoresistive element, the at least one yoke, and the ferromagnetic layer; the antiferromagnetic layer includes a facing portion facing the ferromagnetic layer and a non-facing portion facing the magnetoresistive element and the at least one yoke but not facing the ferromagnetic layer, The magnetic sensor is characterized in that the antiferromagnetic portion is entirely formed by the opposing portion of the antiferromagnetic layer.

2. the at least one magnetic field generator is two magnetic field generators; 2. The magnetic sensor according to claim 1, wherein the magnetoresistive element and the at least one yoke are disposed between the two magnetic field generators.

3. the at least one yoke is two yokes; 3. The magnetic sensor according to claim 1, wherein the magnetoresistive element is disposed between the two yokes.

4. 2. The magnetic sensor according to claim 1, wherein the magnetic field generated by the at least one magnetic field generator is applied to the magnetoresistive element.

5. 2. The magnetic sensor according to claim 1, wherein a portion of the at least one magnetic field generator overlaps with the at least one yoke when viewed from a direction perpendicular to the direction in which the magnetoresistive element and the at least one yoke are arranged.

6. The magnetic sensor of claim 1, wherein the antiferromagnetic layer is in contact with the ferromagnetic layer.

7. 2. The magnetic sensor according to claim 1, further comprising an underlayer interposed between the ferromagnetic layer and the antiferromagnetic layer.

8. Further, a lower electrode and an upper electrode each made of a conductive material are provided, the magnetoresistive element is disposed on the lower electrode, 2. The magnetic sensor according to claim 1, wherein the upper electrode is disposed on the magnetoresistive element, the at least one yoke, and the at least one magnetic field generator.

9. the magnetoresistive element includes a plurality of stacked magnetic films, 2. The magnetic sensor according to claim 1, wherein a portion of said at least one magnetic field generator overlaps a portion of said at least one yoke when viewed in the stacking direction of said plurality of magnetic films.

10. the magnetoresistive element includes a plurality of stacked magnetic films, 2. The magnetic sensor according to claim 1, wherein the at least one magnetic field generator does not overlap the at least one yoke when viewed in the stacking direction of the plurality of magnetic films.

11. A magnetoresistive element; at least one yoke including a magnetic layer made of a soft magnetic material and adjacent to the magnetoresistive element with a predetermined gap therebetween; at least one magnetic field generator configured to generate a magnetic field to be applied to the at least one yoke, the magnetic field generator including a ferromagnetic portion made of a ferromagnetic material and an antiferromagnetic portion made of an antiferromagnetic material and exchange-coupled with the ferromagnetic portion; a plurality of resistance units each including the magnetoresistive effect element; the at least one yoke is a plurality of yokes; the at least one magnetic field generator is a plurality of magnetic field generators; each of the plurality of yokes is adjacent to the magnetoresistive element of any one of the plurality of resistor portions; each of the plurality of magnetic field generators is configured so that the magnetic field is applied to one of the plurality of yokes; A magnetic sensor characterized in that the plurality of magnetic field generators include a first specific magnetic field generator whose magnetic field direction is a first direction, and a second specific magnetic field generator whose magnetic field direction is a second direction opposite to the first direction.

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