Magnetoresistance effect element, magnetic sensor and camera module

Abstract

To suppress hysteresis by applying a large bias magnetic field to a magnetization free layer.SOLUTION: A magnetoresistance effect element 1 has a magnetization free layer 10 the magnetization direction of which rotates with an external magnetic field, a magnetization fixed layer the magnetization direction of which is fixed in a first direction X, a nonmagnetic spacer layer which is located between the magnetization free layer 10 and magnetization fixed layer, and two magnet layers 21, 22 between which the magnetization free layer 10 is sandwiched in a second direction Y different from the first direction X. When viewed from a third direction Z orthogonal to the first direction X and second direction Y, the magnetization free layer 10 has an end E1 opposed to one of two magnet layers 21, 22 and two linear sides S1, S2 connected to the end E1 and extending in mutually different directions, and the two sides S1, S2 are inclined from the second direction Y.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a magnetoresistive element, and a magnetic sensor and a camera module including the same. [Background technology]

[0002] A magnetoresistive effect element used in a magnetic sensor or the like has a magnetization free layer whose magnetization direction rotates in response to an external magnetic field, a magnetization fixed layer whose magnetization direction is fixed, and a spacer layer located between the magnetization free layer and the magnetization fixed layer and having a magnetoresistive effect. To stabilize the magnetization direction of the magnetization free layer when no external magnetic field is applied, a magnet layer that applies a bias magnetic field to the magnetization free layer may be provided. Patent Document 1 discloses a magnetoresistive effect element having a magnet layer surrounding the magnetization free layer. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-169613 Summary of the Invention [Problem to be solved by the invention]

[0004] It is known that when the magnetization free layer has a rectangular shape, the magnetization direction near the boundary between the magnetization free layer and the magnet layer is tilted relative to other parts of the magnetization free layer due to the influence of a demagnetizing field. The magnetization free layer described in Patent Document 1 has an elliptical shape, which reduces the influence of the demagnetizing field and therefore reduces output hysteresis. However, because the magnet layer surrounds the magnetization free layer, magnetic flux easily bypasses the magnetization free layer, making it difficult to apply a bias magnetic field to the magnetization free layer.

[0005] An object of the present disclosure is to provide a magnetoresistive element that can apply a large bias magnetic field to a magnetization free layer and can suppress hysteresis. [Means for solving the problem]

[0006] The magnetoresistive effect element of the present disclosure includes a magnetization free layer whose magnetization direction rotates due to an external magnetic field, a magnetization fixed layer whose magnetization direction is fixed in a first direction, a nonmagnetic spacer layer located between the magnetization free layer and the magnetization fixed layer, and two magnet layers sandwiching the magnetization free layer in a second direction different from the first direction. When viewed from a third direction perpendicular to the first and second directions, the magnetization free layer has an end facing either of the two magnet layers and two linear sides connected to the end and extending in different directions from each other, the two sides being inclined from the second direction. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to provide a magnetoresistive element capable of applying a large bias magnetic field to a magnetization free layer and suppressing hysteresis. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic configuration diagram of a magnetoresistive effect element according to a first embodiment of the present disclosure. [Figure 2] FIG. 2 is a plan view of the magnetization free layer and the magnet layer shown in FIG. [Figure 3] FIG. 10 is a diagram illustrating hysteresis in Comparative Example 1. [Figure 4] FIG. 10 is a diagram illustrating hysteresis in Comparative Example 2. [Figure 5] FIG. 2 is a conceptual diagram showing the relationship between a magnet layer and magnetic flux. [Figure 6] FIG. 10 is a diagram showing a calculation model used in a simulation of hysteresis. [Figure 7] 10 is a graph showing a simulation result of hysteresis. [Figure 8] FIG. 4 is a schematic configuration diagram of a magnetoresistive effect element according to a modified example of the first embodiment. [Figure 9] FIG. 10 is a plan view of a magnetization free layer and a magnet layer of a magnetic sensor according to a second embodiment of the present disclosure. [Figure 10]FIG. 10 is a schematic configuration diagram of a magnetic sensor according to a third embodiment of the present disclosure. [Figure 11] FIG. 10 is a schematic configuration diagram of a camera module according to a fourth embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0009] Embodiments of the magnetoresistive effect element, magnetic sensor, and camera module of the present disclosure will be described with reference to the drawings. In the following description and drawings, a first direction X is the magnetic detection direction of the magnetoresistive effect element 1 and coincides with the magnetization direction of the magnetization fixed layer. A second direction Y is the direction in which two magnet layers (hereinafter referred to as a first magnet layer 21 and a second magnet layer 22) are arranged, and a third direction Z coincides with the stacking direction of the laminate 4 described below. The first direction X and the second direction Y are parallel to the element mounting surface 2A of the substrate 2, and the first direction X, the second direction Y, and the third direction Z are perpendicular to each other. Note that the second direction Y does not have to be perpendicular to the first direction X, as long as it is a direction different from the first direction X.

[0010] (First embodiment) FIG. 1 is a cross-sectional view showing a schematic configuration of a magnetoresistive effect element 1 according to a first embodiment, and FIG. 2 is a plan view of a magnetization free layer 10 and a magnet layer taken along line AA in FIG. 1. Referring to FIG. 1, the magnetoresistive effect element 1 has a substrate 2, a lower electrode layer 3, a stacked body 4, and an upper electrode layer 11. The stacked body 4 has an antiferromagnetic layer 5, an outer magnetization pinned layer 6, a nonmagnetic intermediate layer 7, an inner magnetization pinned layer 8, a spacer layer 9, and a magnetization free layer 10, and these layers 5 to 10 are stacked in the above order from the lower electrode layer 3 to the upper electrode layer 11 in a third direction Z. A sense current flows through the stacked body 4 in the third direction Z by the lower electrode layer 3 and the upper electrode layer 11.

[0011] The magnetization free layer 10 is a magnetic layer whose magnetization direction rotates in response to an external magnetic field, and may be made of, for example, NiFe. The spacer layer 9 is a non-magnetic layer located between the magnetization free layer 10 and the magnetization fixed layer 8. The spacer layer 9 may be made of a non-magnetic insulator such as Al2O3 or MgO, or a non-magnetic conductor such as Cu. When the spacer layer 9 is a non-magnetic insulator, the magnetoresistive element 1 functions as a tunneling magnetoresistive (TMR) element. When the spacer layer 9 is a non-magnetic conductor, the magnetoresistive element 1 functions as a giant magnetoresistive (GMR) element. The TMR element has a larger MR change rate than the GMR element, and can increase the output voltage of the magnetic sensor 100, which will be described later.

[0012] The inner magnetization pinned layer 8 is a ferromagnetic layer sandwiched between the outer magnetization pinned layer 6 and a spacer layer 9. The inner magnetization pinned layer 8 is antiferromagnetically coupled to the outer magnetization pinned layer 6 via a nonmagnetic intermediate layer 7 made of Ru, Rh, or the like. The outer magnetization pinned layer 6 is a ferromagnetic layer exchange-coupled with the antiferromagnetic layer 5. The antiferromagnetic layer 5 can be made of PtMn, IrMn, NiMn, or the like. The magnetization directions of the inner magnetization pinned layer 8 and the outer magnetization pinned layer 6 are fixed, and are antiparallel to each other. In this specification, the inner magnetization pinned layer 8 may be simply referred to as the magnetization pinned layer 8.

[0013] The magnetoresistive element 1 has first and second magnet layers 21 and 22 that sandwich the magnetization free layer 10 in the second direction Y and apply a bias magnetic field to the magnetization free layer 10. The first and second magnet layers 21 and 22 face each other in the second direction Y across a gap G. The first and second magnet layers 21 and 22 have the same configuration and shape and are symmetrical about a second axis C2 (described later). The magnetization direction of the magnetization free layer 10 preferably faces the second direction Y when no external magnetic field to be detected is applied (hereinafter referred to as a zero magnetic field). The first and second magnet layers 21 and 22 are magnetized in the same direction in the second direction Y (to the right in FIGS. 1 and 2 ), and apply a bias magnetic field generally in the second direction Y to the magnetization free layer 10. The first and second magnet layers 21 and 22 are made of a hard magnetic material such as CoPt or CoCrPt. 1, the first and second magnet layers 21, 22 are provided over almost the entire area of ​​the laminate 4 in the third direction Z, but they only need to be provided on the sides of the magnetization free layer 10 in the second direction Y. An insulating layer 31 made of Al2O3 or the like is provided between the first and second magnet layers 21, 22 and the laminate 4. The insulating layer 31 prevents the sense current flowing through the laminate 4 from leaking to the first and second magnet layers 21, 22, and in particular prevents a short circuit between the magnetization free layer 10 and the magnetization fixed layer 8. Note that the insulating layer 31 is not shown in FIG. 2.

[0014] The magnetoresistive effect element 1 is generally formed so that the second direction Y is longer and narrower than the first direction X. Therefore, as shown in FIG. 2, when viewed from the third direction Z, the magnetization free layer 10 is longer and narrower in the second direction Y than the first direction X, and the shape anisotropy effect makes it easier for the magnetization direction to be oriented in the second direction Y. Furthermore, as described above, a bias magnetic field is applied to the magnetization free layer 10 in the second direction Y by the first and second magnet layers 21 and 22. For the above reasons, the magnetization free layer 10 is generally magnetized in the second direction Y in a zero magnetic field state. In contrast, the magnetization fixed layer 8 is generally magnetized in the first direction X. When an external magnetic field is applied in the first direction X, which is the magnetically sensitive direction, the magnetization direction of the magnetization free layer 10 rotates clockwise or counterclockwise in FIG. 2 depending on the strength of the external magnetic field. This changes the relative angle between the magnetization direction of the magnetization fixed layer 8 and the magnetization direction of the magnetization free layer 10, changing the electrical resistance to the sense current of the magnetoresistive element 1. Based on this change in electrical resistance, the magnetoresistive element 1 detects the strength of the external magnetic field in the detection direction.

[0015] Next, the configuration of the magnetization free layer 10 and the first and second magnet layers 21 and 22 will be described in more detail with reference to FIG. 2. When viewed from the third direction Z, the magnetization free layer 10 has two ends (hereinafter referred to as the first end E1 and the second end E2) facing the first and second magnet layers 21 and 22, a first axis C1, and a second axis C2. The first axis C1 passes through the first and second ends E1 and E2 and is parallel to the second direction Y. The second axis C2 passes through a point on the first axis C1 equidistant from the first end E1 and the second end E2 and is perpendicular to the first axis C1. The first axis C1 coincides with the central axis of the magnetization free layer 10 in the second direction Y. The magnetization free layer 10 is symmetrical with respect to the first axis C1 and the second axis C2.

[0016] When viewed from the third direction Z, the magnetization free layer 10 is roughly hexagonal in shape and has two straight sides (hereinafter referred to as the first side S1 and the second side S2) connected to the first end E1 and extending in different directions, two straight sides (hereinafter referred to as the third side S3 and the fourth side S4) connected to the second end E2 and extending in different directions, a straight fifth side S5 connecting the first side S1 and the third side S3, and a straight sixth side S6 connecting the second side S2 and the fourth side S4.

[0017] The second side S2, the fourth side S4, and the sixth side S6 are symmetrical to the first side S1, the third side S3, and the fifth side S5, respectively, with respect to the first axis C1. The third side S3, the fourth side S4, and the second end E2 are symmetrical to the first side S1, the second side S2, and the first end E1, respectively, with respect to the second axis C2. The first side S1, the third side S3, and the fifth side S5 extend on one side of the first axis C1 with respect to the first direction X, and the second side S2, the fourth side S4, and the sixth side S6 extend on the other side of the first axis C1 with respect to the first direction X. That is, the first side S1 and the second side S2 connected to the first end E1 extend on both sides of the first axis C1 in the first direction X, and the third side S3 and the fourth side S4 connected to the second end E2 also extend on both sides of the first axis C1 in the first direction X. The first to fourth sides S1 to S4 are inclined with respect to the first direction X and the second direction Y. The fifth side S5 and the sixth side S6 are parallel to the second direction Y, but may be curved in the first direction X, for example. Since the shape of the first end E1 side and the shape of the second end E2 side of the magnetization free layer 10 are the same, the shape of the first end E1 side will be described below.

[0018] By providing the first end E1 and the second end E2 in the magnetization free layer 10 in this manner, hysteresis in the output of the magnetoresistive effect element 1 can be suppressed. In FIGS. 3(a) to 3(f), the magnetization direction of the magnetization free layer 50 of Comparative Example 1 when an external magnetic field is applied is indicated by an arrow, and FIG. 3(g) shows the states of FIGS. 3(a) to 3(f) as the relationship between the external magnetic field and the output. The magnetization free layer 50 of Comparative Example 1 is rectangular, and here, the first and second magnet layers 51 and 52 are also rectangular. The positive direction in the first direction X is the +X direction, and the negative direction is the -X direction. An external magnetic field was applied so as to change from the +X direction to the -X direction, and then so as to change from the -X direction to the +X direction. The bias magnetic field By is oriented to the right in FIGS. 3(a) to 3(f).

[0019] As shown in FIG. 3(a), when a large external magnetic field is applied in the +X direction, the magnetization direction of the magnetization free layer 50 is generally oriented in the +X direction (point A in FIG. 3(g)). As shown in FIG. 3(b), when the external magnetic field strength in the +X direction decreases, the contribution of the bias magnetic field increases, and the magnetization direction of the magnetization free layer 50 rotates clockwise, but the magnetization direction of the magnetization free layer 50 generally remains in the same direction (point B in FIG. 3(g)). As shown in FIG. 3(c), when the external magnetic field strength in the X direction becomes zero, the magnetization direction of the magnetization free layer 50 in the part away from the first and second magnet layers 51 and 52 is oriented in the same direction as the bias magnetic field, but the influence of the demagnetizing field becomes relatively strong at the end facing the first and second magnet layers 51 and 52. Because the demagnetizing field acts to prevent the rotation of the magnetic field direction of the magnetization free layer 50, the magnetization direction at the end face of the magnetization free layer 50 tilts upward. As a result, the magnetization direction of the magnetization free layer 50 points slightly upward on average (point C in FIG. 3(g)). As shown in FIG. 3(d), when an external magnetic field is applied in the -X direction, the magnetization direction of the magnetization free layer 50 rotates clockwise, but the magnetization direction of the magnetization free layer 50 points in the same direction overall (point D in FIG. 3(g)). As shown in FIG. 3(e), when a large external magnetic field is applied in the -X direction, the magnetization direction of the magnetization free layer 50 points in the -X direction overall (point E in FIG. 3(g)).

[0020] As the external magnetic field is changed from the -X direction to the +X direction, the state returns from that shown in FIG. 3(e) to that shown in FIG. 3(d). However, as shown in FIG. 3(f), when the external magnetic field strength in the X direction becomes zero, the magnetization direction at the end face of the magnetization free layer 50 tilts downward due to the influence of the demagnetizing field (point F in FIG. 3(g)). As a result, the magnetization direction of the magnetization free layer 50 points slightly downward on average. When an external magnetic field is applied in the +X direction, the state returns to that shown in FIG. 3(a) via the state shown in FIG. 3(b). The magnetization direction of the magnetization free layer 50 is determined so that the sum of the magnetostatic energy and the exchange energy is minimized. However, the sum of the magnetostatic energy and the exchange energy is the same at points C and F. Therefore, in a zero magnetic field, the magnetization state of the magnetization free layer 50 differs when the magnetic field changes from the +X direction to the -X direction and when it changes from the -X direction to the +X direction. As a result, the output of the magnetoresistive effect element 1 can selectively take two values ​​in a zero magnetic field, resulting in hysteresis.

[0021] In contrast, in this embodiment, the magnetization free layer 10 is provided with a first end E1 as shown in FIG. 2, which suppresses the influence of the demagnetizing field and reduces hysteresis. Since a sharp first end E1 reduces hysteresis, the first end E1 is preferably an edge, but may be somewhat rounded. For the same reason, since a tip region of the magnetization free layer 10 in the Y direction has an elongated shape, hysteresis is reduced. Therefore, the angle θ1 between the first side S1 and the second side S2 is preferably 20 degrees or more and 120 degrees or less, and more preferably 20 degrees or more and 100 degrees or less.

[0022] FIG. 4 is a plan view of the magnetization free layer 60 and the first and second magnet layers 61 and 62 of the magnetoresistive effect element of Comparative Example 2. When viewed from the third direction Z, the side of the magnetization free layer 60 facing the first and second magnet layers 61 and 62 is a straight line that is inclined with respect to the second axis C2 of the magnetization free layer 60. The bias magnetic field By faces to the right. Compared to the present embodiment, Comparative Example 2 does not have the first side S1 and the second side S2 that extend in different directions on both sides of the first axis C1. The surfaces of the first and second magnet layers 61 and 62 facing the magnetization free layer 10 are also inclined with respect to the second axis C2 of the magnetization free layer 10. As shown in FIG. 4(a), when an external magnetic field in the +Y direction is applied, the magnetization direction along the side of the magnetization free layer 60 facing the first and second magnet layers 61 and 62 is downward. However, when the magnetization direction of the magnetization free layer 60 is reversed as shown in Figure 4(b), the magnetization direction of the boundary also moves upward, which causes hysteresis in the output, making it difficult to ensure the reliability of the magnetoresistive effect element.

[0023] In contrast, in this embodiment, the first side S1 and the second side S2 extend on both sides of the first axis C1 and are inclined from the second direction Y, so the X-direction components of the magnetization along the first side S1 and the second side S2 cancel each other out. This makes it possible to suppress large hysteresis. In particular, when the first side S1 and the second side S2 are symmetrical with respect to the first axis C1, the magnetic flux along the first side S1 and the second side S2 cancel each other out more effectively in the X-direction, making it possible to suppress large hysteresis.

[0024] 2, the first magnet layer 21 facing the first end E1 has a first recess 23 that accommodates the first side S1 and the second side S2 of the magnetization free layer 10 on the surface facing the second magnet layer 22. The second magnet layer 22 facing the second end E2 has a second recess 24 that accommodates the third side S3 and the fourth side S4 of the magnetization free layer 10 on the surface facing the first magnet layer 21. Since the first magnet layer 21 and the second magnet layer 22 have the same configuration and shape, the configuration of the first magnet layer 21 will be described below. When viewed from the third direction Z, the first recess 23 has a shape complementary to the first and second sides S1 and S2. Specifically, as viewed from the third direction Z, the first recess 23 has a bottom 25 that faces the first end E1 in the second direction Y, and two linear side portions 26 that are connected to the bottom 25 and face the first and second sides S1 and S2 in the second direction Y. The angle θ2 formed by the two side portions 26 is preferably the same as the angle θ1 formed between the first side S1 and the second side S2. The bottom 25 is ideally the intersection of the first side S1 and the second side S2, but may be slightly rounded.

[0025] FIG. 5(a) schematically illustrates the magnetic flux flowing between the first magnet layer 21 and the second magnet layer 22 of this embodiment. Region 29 is the region between the first recess 23 and the second recess 24. The magnetization free layer 10 is indicated by a dashed line. By providing the first recess 23 in the first magnet layer 21 and the second recess 24 in the second magnet layer 22, the magnetic flux near the first axis C1 bends slightly inward to approach the first axis C1. This makes it easier to apply a magnetic field in the Y direction to the magnetization free layer 10 uniformly, further suppressing hysteresis in the output of the magnetoresistive effect element 1. The configuration shown in FIG. 5(b) is a modified example of this embodiment. The first and second magnet layers 21 and 22 are rectangular when viewed from the third direction Z, and no recesses are provided. The magnetic flux near the first axis C1 bends outward to move away from the first axis C1. Although the bias magnetic field is less likely to align in the Y direction compared to the present embodiment, the shape of the magnetization free layer 10 allows for suppression of hysteresis in the output of the magnetoresistive element 1. The configuration shown in FIG. 5(c) is another variation of the present embodiment. When viewed from the third direction Z, the first magnet layer 21 has a first recess 23, the second magnet layer 22 has a second recess 24, and the magnetization free layer 10 is rectangular. Because the bias magnetic field is generated in the same manner as in FIG. 5(a), this configuration also allows for suppression of hysteresis in the output of the magnetoresistive element 1. FIG. 5(d) shows a magnet layer 70 of Comparative Example 3. A diamond-shaped opening 71 is provided in the center, and the magnetization free layer 10 of the present embodiment is disposed in the diamond-shaped opening 71. A magnetic field is applied in the Y direction near the first axis C1, but the bias magnetic field applied to the magnetization free layer 10 is weak because the magnetic flux mainly flows to the sides of the magnetization free layer 10.

[0026] As can be understood from the above explanation, in order to effectively apply a magnetic field in the Y direction to the magnetization free layer 10, it is preferable to provide two independent magnet layers 21 and 22 on both sides of the magnetization free layer 10 in the Y direction. Furthermore, since magnetic flux that is relatively aligned in the Y direction is generated in the region 29 between the first recess 23 and the second recess 24 (see FIG. 5(a)), it is preferable that the magnetization free layer 10 be completely contained in the region 29 in order to apply this magnetic flux to the magnetization free layer 10. To achieve this, referring to FIG. 2, it is preferable that the dimension of the opening 27 of the first recess 23 in the first direction X is larger than the dimension of the magnetization free layer 10 at the opening 27 in the first direction X. Furthermore, it is preferable that the surface of the first magnet layer 21 where the opening 27 is provided has surfaces 28 facing the second magnet layer 22 on both sides of the opening 27. In this embodiment, the first recess 23 is larger than the triangular end region 30 of the magnetization free layer 10. Specifically, the two linear sides 26 are longer than the first side S1 and the second side S2, and the first recess 23 accommodates a part of the fifth side S5 and a part of the sixth side S6. The same is true for the second magnet layer 22.

[0027] To confirm the effect of this embodiment, a hysteresis simulation was performed using the calculation model shown in FIG. 6. The simulation was performed using the simulation program "Mumax3," and reference was made to "Vansteenkiste et al., AIP Adv. 4,107133 (2014)" and "Exlet al., J. Appl. Phys. 115, 17D118 (2014)." FIG. 6(a) is a plan view of the magnetization free layer 80 and the first and second magnet layers 81 and 82 of Comparative Example 4, as viewed from the third direction Z, and FIG. 6(b) is a plan view of the magnetization free layer 10 and the first and second magnet layers 21 and 22 of the example, as viewed from the third direction Z. The saturation magnetization of the magnetization free layers 10 and 80 and the magnet layers 21, 22, 81, and 82 is 1 [T], and the exchange stiffness coefficient of the magnetization free layers 10 and 80 is 1×10 -11[J / m], and the film thickness of the magnetization free layers 10, 80 and the magnet layers 21, 22, 81, 82 was 10 [nm]. The magnet layers 21, 22, 81, 82 were permanent magnet layers with a single magnetic domain structure, and the magnetization direction was fixed in the second direction Y. The external magnetic field Bx in the first direction X was decreased from +20 [mT] to -20 [mT] in 2 [mT] steps, and then the external magnetic field Bx was increased from -20 [mT] to +20 [mT] in 2 [mT] steps. The external magnetic field By in the second direction Y and the external magnetic field Bz in the third direction Z were set to 0.

[0028] FIG. 7(a) shows the results of Comparative Example 4, and FIG. 7(b) shows the results of the Example. The horizontal axis represents the magnetic field Bx in the first direction X, and the vertical axis represents the value obtained by normalizing the X component of the total magnetic moment of the magnetization free layer by the saturation magnetic moment of the magnetization free layer, which corresponds to the resistance of the magnetoresistive effect element. In Comparative Example 4, large hysteresis is observed near zero magnetic field. This hysteresis is thought to occur because the magnetization direction of the magnetization free layer 80 is tilted from the second direction Y near the boundary between the magnetization free layer 80 and the first and second magnet layers 81 and 82. In the Example, in zero magnetic field, the magnetization direction of the magnetization free layer 10 is not tilted from the second direction Y near the boundary between the magnetization free layer 10 and the first and second magnet layers 21 and 22. As a result, it is thought that the occurrence of hysteresis is suppressed.

[0029] FIG. 8 is a cross-sectional view showing a schematic configuration of a magnetoresistive effect element 1 according to another modification of the first embodiment. The first and second magnet layers 21 and 22 each include a ferromagnetic layer 32 and an antiferromagnetic layer 33. The ferromagnetic layer 32 faces the magnetization free layer 10 in the second direction Y. The ferromagnetic layer 32 is made of CoFe. The antiferromagnetic layer 33 is made of an alloy such as IrMn, Fe—Mn, Ni—Mn, Pt—Mn, or Pd—Pt—Mn, and is strongly exchange-coupled with the adjacent ferromagnetic layer 32. The ferromagnetic layer 32 applies a bias magnetic field to the magnetization free layer 10, similar to the first and second magnet layers 21 and 22 in the first embodiment. The magnetization direction of the ferromagnetic layer 32 is firmly fixed in the second direction Y by the antiferromagnetic layer 33, thereby suppressing hysteresis in the first and second magnet layers 21 and 22 in zero magnetic field.

[0030] (Second embodiment) FIG. 9 is a diagram similar to FIG. 2 of the magnetic sensor 1 according to the second embodiment, showing a plan view of the magnetization free layer and the magnet layers. The configuration and effects omitted are the same as those of the first embodiment. In this embodiment, the dimension L1 of the first magnet layer 21 in the second direction Y is larger than the dimension W1 of the first direction X, and the dimension L2 of the second magnet layer 22 in the second direction Y is larger than the dimension W2 of the first direction X. This allows the direction in which the shape anisotropy effect of the first magnet layer 21 and the second magnet layer 22 occurs to be aligned with the second direction Y. As a result, the bias magnetic field can be stably applied to the magnetization free layer 10, and hysteresis in the first and second magnet layers 21 and 22 at zero magnetic field is further suppressed. By magnetizing the first magnet layer 21 and the second magnet layer 22 in the second direction Y, the magnetization directions of the first magnet layer 21 and the second magnet layer 22 are more likely to be aligned with the second direction Y. Furthermore, when the magnetization free layer 10 is elongated in the second direction Y, the shape anisotropy of the magnetization free layer 10 also faces the second direction Y, making the output of the magnetic sensor 1 more stable. Although not shown, this embodiment can also be combined with the first embodiment and its modifications, as well as the third and fourth embodiments. In particular, the modification shown in FIG. 8 can be suitably combined with this embodiment because stability due to the shape anisotropy of the first and second magnet layers 21 and 22 is important.

[0031] (Third embodiment) A schematic configuration of a magnetic sensor 100 including the magnetoresistive effect element 1 of the present disclosure will be described with reference to FIG. 10. FIG. 10 shows a schematic circuit diagram of the magnetic sensor 100. The magnetic sensor 100 has four magnetoresistive effect elements (hereinafter referred to as first to fourth magnetoresistive effect elements 101 to 104), which are connected to each other by a bridge circuit (Wheatstone bridge). All four magnetoresistive effect elements 101 to 104 are the magnetoresistive effect elements 1 of the first embodiment. The four magnetoresistive effect elements 101 to 104 are divided into two sets 101, 102 and 103, 104, and the magnetoresistive effect elements 101, 102 and the magnetoresistive effect elements 103, 104 of each set are connected in series. One end of each of the sets 101, 102 and 103, 104 of magnetoresistive effect elements is connected to a power supply voltage Vcc, and the other end is grounded (GND).

[0032] A midpoint voltage V1 between the first magnetoresistive element 101 and the second magnetoresistive element 102 and a midpoint voltage V2 between the third magnetoresistive element 103 and the fourth magnetoresistive element 104 are extracted. The voltage drop across each magnetoresistive element 101-104 is approximately proportional to the electrical resistance of the magnetoresistive element 101-104. Therefore, if the electrical resistances of the first to fourth magnetoresistive elements 101-104 are R1-R4, respectively, the midpoint voltage V1 is V1 = R2 / (R1 + R2) × Vcc, and the midpoint voltage V2 is V2 = R3 / (R3 + R4) × Vcc. By detecting the difference V1-V2 between the midpoint voltages V1 and V2, twice the sensitivity can be achieved compared to detecting the midpoint voltages V1 and V2. Furthermore, even if the midpoint voltages V1 and V2 are offset, detecting the difference can eliminate the effect of the offset. Furthermore, the hysteresis of the outputs of the magnetoresistive elements 101 to 104 included in the magnetic sensor 100 is suppressed, improving the stability of the output signals.

[0033] (Fourth embodiment) With reference to FIG. 11 , a schematic configuration of a camera module 200 including a magnetic sensor 100 according to the present disclosure will be described. The camera module 200 is capable of autofocusing and optical image stabilization. The camera module 200 includes a lens 201 and four drive magnet layers 202 arranged around the lens 201. A first coil 205 is provided below each drive magnet layer 202 in the Z direction. The lens 201 is held by a holding member 204, to which a plurality of second coils 206 are attached so as to surround the lens 201. A sense magnet layer 203 is disposed on the holding member 204. Although not shown, another sense magnet layer having a configuration similar to that of the sense magnet layer 203 is disposed on the opposite side of the lens 201 from the sense magnet layer 203. The magnetic sensor 100 is disposed on a substrate (not shown) of the camera module 200. All elements other than the holding member 204 are stationary. The sense magnet layer 203 moves relative to the magnetic sensor 100 , but the drive magnet layer 202 is stationary relative to the magnetic sensor 100 .

[0034] For autofocus operation, current is passed through the second coil 206. The Lorentz force causes the lens 201 to move in the Z direction relative to the drive magnet layer 202. For optical image stabilization operation, current is passed through the first coil 205. The Lorentz force causes the lens 201 to move in the X direction and / or Y direction relative to the drive magnet layer 202. A composite magnetic field of the external magnetic field generated by the drive magnet layer 202 and the external magnetic field generated by the sense magnet layer 203 is applied to the magnetic sensor 100. The magnetic sensor 100 detects this composite magnetic field, enabling control of autofocus operation and optical image stabilization operation. As described above, the magnetic sensor 100 included in the camera module 200 has improved stability in its output signal, thereby improving the positional accuracy of the camera module 200.

[0035] (Additional Note) This specification includes the following disclosure. [Configuration 1] a magnetization free layer whose magnetization direction rotates in response to an external magnetic field; a magnetization fixed layer whose magnetization direction is fixed in a first direction; a nonmagnetic spacer layer located between the magnetization free layer and the magnetization fixed layer; two magnet layers sandwiching the magnetization free layer in a second direction different from the first direction; A magnetoresistive effect element, wherein when viewed from a third direction perpendicular to the first direction and the second direction, the magnetization free layer has an end facing one of the two magnet layers and two straight sides connected to the end and extending in different directions, the two sides being inclined from the second direction. [Configuration 2] The magnetoresistive element according to configuration 1, wherein the two sides pass through the end portions and extend on either side of an axis parallel to the second direction. [Configuration 3] 3. The magnetoresistive element according to configuration 2, wherein the angle formed by the two sides is equal to or greater than 20 degrees and equal to or less than 120 degrees. [Configuration 4] 4. The magnetoresistive element according to configuration 2 or 3, wherein the two sides are symmetrical with respect to the axis. [Configuration 5] 5. The magnetoresistive element according to any one of configurations 1 to 4, wherein the lengths of the two magnet layers in the first direction are longer than the length of the magnetization free layer in the first direction. [Configuration 6] 6. The magnetoresistive element according to any one of configurations 1 to 5, wherein the magnetization free layer is elongated in the second direction. [Configuration 7] 7. The magnetoresistive element according to any one of configurations 1 to 6, wherein each of the two magnet layers has a ferromagnetic layer and an antiferromagnetic layer. [Configuration 8] 8. The method for manufacturing a magnetic sensor according to any one of configurations 1 to 7, wherein the length of the two magnet layers in the second direction is longer than the length of the two magnet layers in the first direction. [Configuration 9] 9. The magnetoresistive element according to any one of configurations 1 to 8, wherein the magnetic layer facing the end portion has a recess that accommodates the two sides. [Configuration 10] A magnetoresistive effect element as described in configuration 9, wherein, when viewed from the third direction, the recess has a bottom that faces the end in the second direction and two linear side portions that face the two sides in the second direction. [Configuration 11] 11. The magnetoresistive element of claim 10, wherein the two linear sides are longer than the two edges. [Configuration 12] 12. The magnetoresistive element according to any one of configurations 8 to 11, wherein the dimension of the opening of the recess in the first direction is larger than the dimension of the opening of the magnetization free layer in the first direction. [Configuration 13] a magnetization free layer whose magnetization direction rotates in response to an external magnetic field; a magnetization fixed layer whose magnetization direction is fixed in a first direction; a nonmagnetic spacer layer located between the magnetization free layer and the magnetization fixed layer; two magnet layers sandwiching the magnetization free layer in a second direction different from the first direction; A magnetoresistive effect element, wherein, when viewed from a third direction perpendicular to the first direction and the second direction, the magnetization free layer has an end facing one of the two magnet layers, the magnet layer has a recess facing the end, and the recess has a bottom and two linear side portions connected to the bottom. [Configuration 14] 14. A magnetic sensor comprising the magnetoresistive element according to any one of configurations 1 to 13. [Configuration 15] A camera module having the magnetic sensor according to configuration 14. [Explanation of symbols]

[0036] 1. Magnetoresistive element 8 Magnetization fixed layer 9 Spacer Layer 10 Magnetization free layer 21, 22 First and second magnet layers 23, 24 First and second recesses 25 Bottom 26 Side 32 Ferromagnetic layer 33 Antiferromagnetic layer 100 Magnetic Sensor 200 Camera Module C1, C2 First and second axes E1, E2 First and second ends S1~S6 1st to 6th sides X first direction Y Second direction Z third direction

Claims

1. a magnetization free layer whose magnetization direction rotates in response to an external magnetic field; a magnetization fixed layer whose magnetization direction is fixed in a first direction; a nonmagnetic spacer layer located between the magnetization free layer and the magnetization fixed layer; two magnet layers sandwiching the magnetization free layer in a second direction different from the first direction; A magnetoresistive effect element, wherein when viewed from a third direction perpendicular to the first direction and the second direction, the magnetization free layer has an end facing either of the two magnet layers and two straight sides connected to the end and extending in different directions, the two sides being inclined from the second direction.

2. 2. The magnetoresistive element according to claim 1, wherein said two sides extend on both sides of an axis that passes through said end portion and is parallel to said second direction.

3. 3. The magnetoresistive element according to claim 2, wherein the angle formed by the two sides is equal to or greater than 20 degrees and equal to or less than 120 degrees.

4. 3. The magnetoresistive element according to claim 2, wherein said two sides are symmetrical with respect to said axis.

5. 2. The magnetoresistive element according to claim 1, wherein the lengths of the two magnet layers in the first direction are longer than the length of the magnetization free layer in the first direction.

6. The magnetoresistive element according to claim 1 , wherein the magnetization free layer is elongated in the second direction.

7. 2. The magnetoresistive element according to claim 1, wherein each of said two magnet layers has a ferromagnetic layer and an antiferromagnetic layer.

8. The method for manufacturing a magnetic sensor according to claim 1 , wherein the length of the two magnet layers in the second direction is longer than the length of the two magnet layers in the first direction.

9. The magnetoresistive element according to claim 1 , wherein the magnetic layer facing the end portion has a recess for accommodating the two sides.

10. 10. The magnetoresistive effect element of claim 9, wherein, when viewed from the third direction, the recess has a bottom that faces the end in the second direction and two linear side portions that face the two sides in the second direction.

11. The magnetoresistive element according to claim 10 , wherein the two linear sides are longer than the two edges.

12. 10. The magnetoresistive element according to claim 9, wherein a dimension of the opening of the recess in the first direction is larger than a dimension of the magnetization free layer in the opening in the first direction.

13. a magnetization free layer whose magnetization direction rotates in response to an external magnetic field; a magnetization fixed layer whose magnetization direction is fixed in a first direction; a nonmagnetic spacer layer located between the magnetization free layer and the magnetization fixed layer; two magnet layers sandwiching the magnetization free layer in a second direction different from the first direction; A magnetoresistive effect element, wherein, when viewed from a third direction perpendicular to the first direction and the second direction, the magnetization free layer has an end facing either of the two magnet layers, the magnet layer has a recess facing the end, and the recess has a bottom and two linear side portions connected to the bottom.

14. A magnetic sensor comprising the magnetoresistive element according to claim 1 .

15. A camera module comprising the magnetic sensor of claim 14.

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