Magnetic sensor

Abstract

The magnetic sensor includes a plurality of first MR elements and a plurality of second MR elements. Each of the plurality of first MR elements and the plurality of second MR elements has a resistance value change characteristic in which the resistance value changes in accordance with the steady state of the magnetic vortex structure when the intensity of the applied magnetic field is the same. The statistical distribution of the amount of change in resistance of the plurality of first MR elements becomes a first distribution centered on the first value. The statistical distribution of the amount of change in resistance of the plurality of second MR elements becomes a second distribution centered on the second value. A group including the plurality of first MR elements and the plurality of second MR elements has a characteristic in which a statistical distribution of the amount of change in resistance becomes a third distribution centered on a third value between the first value and the second value.

Description

Technical Field

[0001] This disclosure relates to a magnetic sensor having multiple magnetoresistive effect elements, each comprising a free layer configured to have a magnetic vortex structure. Background Technology

[0002] In recent years, magnetic sensors have been used in various applications. Among magnetic sensors, those using a spin-valve type magnetoresistive effect element disposed on a substrate are known. The spin-valve type magnetoresistive effect element has a magnetization fixed layer whose magnetization direction is fixed, a free layer whose magnetization direction can change according to the direction of the applied magnetic field, and a gap layer disposed between the magnetization fixed layer and the free layer.

[0003] U.S. Patent Application Publication No. 2023 / 0324477 discloses a magnetic sensor device having multiple TMR (tunneling magnetoresistive) elements. The TMR elements have a free layer with a disk-shaped structure. A magnetization pattern, also known as a vortex state, with closed magnetic flux is spontaneously formed in the free layer. In the magnetoresistive effect element containing a free layer with a magnetic vortex structure as described in U.S. Patent Application Publication No. 2023 / 0324477, the center of the magnetic vortex structure moves according to the magnetic field of the object being detected, thereby changing the resistance value of the magnetoresistive effect element.

[0004] In a free layer with a magnetic vortex structure, there are cases where the magnetization direction in the steady state is clockwise and cases where the magnetization direction in the steady state is counterclockwise. Ideally, the resistance value of a magnetoresistive element should change in the same way in both cases. However, in reality, due to the structure of the magnetoresistive element, its resistance value can sometimes differ.

[0005] Furthermore, sometimes an external magnetic field, which is not the magnetic field of the object being detected, is temporarily applied to the magnetic sensor, i.e., an external magnetic field that saturates the free layer. In a free layer with a magnetic vortex structure, the direction of magnetization in the steady state sometimes reverses after such an external magnetic field is applied. As a result, the characteristics of the magnetic sensor sometimes change before and after the application of the external magnetic field. Summary of the Invention

[0006] The purpose of this disclosure is to provide a magnetic sensor that can suppress variations in characteristics caused by the direction of magnetization of a free layer that is configured to have a magnetic vortex structure.

[0007] An embodiment of the first aspect of this disclosure discloses a magnetic sensor configured to include a plurality of first magnetoresistive elements and a plurality of second magnetoresistive elements, and to generate a detection signal by detecting the magnetic field of a detected object. The plurality of first magnetoresistive elements are electrically connected to the plurality of second magnetoresistive elements. Each of the plurality of first and second magnetoresistive elements includes a magnetization-fixed layer whose magnetization direction is fixed, and a free layer capable of having a magnetic vortex structure, wherein the center of the magnetic vortex structure can move according to an applied magnetic field, and has a resistance value variation characteristic where the resistance value changes according to the stable state of the magnetic vortex structure when the applied magnetic field strength is the same. A first group of multiple first magnetoresistive elements has a parameter corresponding to the resistance value variation characteristic, i.e., a statistical distribution of the resistance change, which is centered on a first value. A second group of multiple second magnetoresistive elements has a statistical distribution of the resistance change, which is centered on a second value different from the first value. A third group of multiple first and second magnetoresistive elements has a statistical distribution of the resistance change, which is centered on a third value between the first and second values.

[0008] An embodiment of the second aspect of this disclosure discloses a magnetic sensor configured to include multiple magnetoresistive elements, which detect the magnetic field of a target object and generate a detection signal. Each of the multiple magnetoresistive elements comprises a magnetized fixed layer whose magnetization direction is fixed, and a free layer capable of having a magnetic vortex structure, wherein the center of the magnetic vortex structure can move according to the applied magnetic field. Each element exhibits a resistance value variation characteristic where, when the applied magnetic field strength is the same, the resistance value changes according to the stable state of the magnetic vortex structure. The group of multiple magnetoresistive elements has a parameter corresponding to the resistance value variation characteristic, namely, a statistical distribution of the resistance change centered on a specific value. Each of the multiple magnetoresistive elements is configured such that, when the magnetic field strength of the target object is within a first range, the free layer does not magnetically saturate. When the magnetic field strength of the target object varies within the first range, the detection signal varies within a second range. The group has the following characteristic: as the number of multiple magnetoresistive elements increases, the statistical distribution of the resistance change of the resistive portion formed by the electrical connection of the multiple magnetoresistive elements approaches a normal distribution, and the standard deviation of the distribution decreases. The number of multiple magnetoresistive effect elements is the amount of change in the detection signal before and after a temporary external magnetic field that saturates the free layer is applied to the multiple magnetoresistive effect elements. That is, the amount of change in the detection signal when the strength of the magnetic field of the detected object is a specific strength within the first range is less than 5% of the difference between the maximum and minimum values ​​in the second range.

[0009] In the magnetic sensors of the first and second embodiments of this disclosure, the statistical distribution of the resistance change, which corresponds to the resistance value change characteristic, has specific characteristics. Therefore, according to this disclosure, it is possible to suppress variations in characteristics caused by the direction of magnetization of the free layer.

[0010] Other objects, features and advantages of this disclosure will become sufficiently clear from the following description. Attached Figure Description

[0011] Figure 1 This is a top view illustrating a magnetic sensor according to a first exemplary embodiment of the present disclosure.

[0012] Figure 2 This is a circuit diagram illustrating the circuit structure of a magnetic sensor according to a first exemplary embodiment of the present disclosure.

[0013] Figure 3 This is a top view showing a portion of the resistor section in a first exemplary embodiment of this disclosure.

[0014] Figure 4 This is a top view showing a portion of the array of elements in a first exemplary embodiment of this disclosure.

[0015] Figure 5 This is a perspective view showing a magnetoresistive element in a first exemplary embodiment of the present disclosure.

[0016] Figure 6 This is a top view showing the free layer of the magnetoresistive effect element in a first exemplary embodiment of the present disclosure.

[0017] Figure 7 This is a top view of the free layer when a magnetic field is applied to a magnetoresistive element in a first exemplary embodiment of this disclosure.

[0018] Figure 8 This is a top view of the free layer when a magnetic field is applied to a magnetoresistive element in a first exemplary embodiment of this disclosure.

[0019] Figure 9 This is an explanatory diagram showing the relationship between the strength of the magnetic field component and the magnitude of the overall magnetization of the free layer in a first exemplary embodiment of this disclosure.

[0020] Figure 10A , Figure 10B and Figure 10C This is a top view schematically illustrating the magnetization of a portion of the magnetized fixed layer and the magnetization of the free layer of the magnetoresistive effect element in a first exemplary embodiment of the present disclosure.

[0021] Figure 11This is an explanatory diagram showing the relationship between the strength of the magnetic field component and the resistance value of the magnetoresistive element in a first exemplary embodiment of this disclosure.

[0022] Figure 12 This is an explanatory diagram showing the statistical distribution of the resistance changes of the first to third groups in the first exemplary embodiment of this disclosure.

[0023] Figure 13 This is an explanatory diagram showing the statistical distribution of the resistance variation of the resistive portion in the first exemplary embodiment of this disclosure.

[0024] Figure 14 This is a top view illustrating an example of the configuration of a magnetoresistive element in a first exemplary embodiment of the present disclosure.

[0025] Figure 15 This is a top view showing a free layer with added structures in a first exemplary embodiment of this disclosure.

[0026] Figure 16 This is a top view of a free layer having a planar shape capable of controlling the direction of magnetization, as shown in a first exemplary embodiment of this disclosure.

[0027] Figure 17 This is a top view showing the MR element and the first structure controlling the direction of magnetization of the free layer in a first exemplary embodiment of this disclosure.

[0028] Figure 18 This is a top view showing the MR element and the second structure controlling the direction of magnetization of the free layer in a first exemplary embodiment of this disclosure.

[0029] Figure 19 This is an illustration schematically showing the direction of the current flowing through the magnetoresistive element in a first exemplary embodiment of the present disclosure.

[0030] Figure 20 This is an illustration schematically showing the magnetic field generated by the current flowing through the magnetoresistive element in a first exemplary embodiment of the present disclosure.

[0031] Figure 21 This is a top view showing a first variant of a magnetic sensor according to a first exemplary embodiment of the present disclosure.

[0032] Figure 22 This is a top view showing a second variation of the magnetic sensor according to a first exemplary embodiment of the present disclosure.

[0033] Figure 23 This is a top view illustrating a third variation of a magnetic sensor according to a first exemplary embodiment of the present disclosure.

[0034] Figure 24 This is a side view showing the magnetoresistive element and shield in a second exemplary embodiment of the present disclosure.

[0035] Figure 25 This is an explanatory diagram showing the relationship between the intensity of the magnetic field component and the detection signal in a second exemplary embodiment of this disclosure. Detailed Implementation

[0036] [First Exemplary Implementation]

[0037] Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. First, referring to... Figure 1 and Figure 2 A schematic structure of a magnetic sensor according to a first exemplary embodiment of the present disclosure will be described. Figure 1 This is a top view of a magnetic sensor 1 illustrating an exemplary embodiment. Figure 2 This is a circuit diagram illustrating the circuit structure of a magnetic sensor 1 according to an exemplary embodiment.

[0038] In the exemplary embodiment, the magnetic sensor 1 includes a plurality of magnetoresistive elements (hereinafter referred to as MR elements) 50. Each MR element 50 is configured such that its resistance value varies according to the magnetic field of the object being detected by the magnetic sensor 1, i.e., the object's magnetic field. Furthermore, the MR elements 50 will be described later... Figure 3 As shown in the figure.

[0039] The magnetic sensor 1 also includes a power supply terminal 11, a ground terminal 12, a first output terminal 13, a second output terminal 14, a first resistor R1, a second resistor R2, a third resistor R3, and a fourth resistor R4. The power supply terminal 11, ground terminal 12, first output terminal 13, and second output terminal 14 are each composed of an electrode layer made of a conductive material. The first to fourth resistor sections R1 to R4 each contain multiple MR elements 50.

[0040] like Figure 2 As shown, the first resistor R1 is disposed between the power supply terminal 11 and the first output terminal 13 in the circuit structure. The second resistor R2 is disposed between the ground terminal 12 and the first output terminal 13 in the circuit structure. The third resistor R3 is disposed between the ground terminal 12 and the second output terminal 14 in the circuit structure. The fourth resistor R4 is disposed between the power supply terminal 11 and the second output terminal 14 in the circuit structure. Furthermore, in this application, the expression "in the circuit structure" is used to indicate the configuration on the circuit diagram, not the configuration in the physical structure.

[0041] A specific voltage or current is applied to power terminal 11. Ground terminal 12 is grounded.

[0042] like Figure 1 As shown, the magnetic sensor 1 also includes a substrate 10. A power supply terminal 11, a ground terminal 12, a first output terminal 13, and a second output terminal 14 are disposed on the substrate 10.

[0043] Here, as Figure 1 As shown, the X, Y, and Z directions are defined. The X, Y, and Z directions are orthogonal to each other. Furthermore, the direction opposite to the X direction is defined as the -X direction, the direction opposite to the Y direction as the -Y direction, and the direction opposite to the Z direction as the -Z direction. In the exemplary embodiment, the direction perpendicular to the surface of the substrate 10 is specifically defined as the Z direction.

[0044] Furthermore, hereinafter, the position in front of a reference point in the Z direction will be referred to as "above," and the position opposite to "above" relative to a reference point will be referred to as "below." Regarding the components of the magnetic sensor 1, the surface at the end in the Z direction will be referred to as the "upper surface," and the surface at the end in the -Z direction will be referred to as the "lower surface." Additionally, the expression "when viewed from a specific direction (e.g., the Z direction)" refers to viewing the object from a position away from the specific direction or a direction parallel to the specific direction.

[0045] The substrate 10 includes component placement regions A1, A2, A3, and A4. In an exemplary embodiment, component placement regions A1 to A4 are defined as planar regions parallel to the XY plane. A plurality of MR elements 50 are respectively configured to overlap any one of component placement regions A1 to A4 when viewed from the Z direction. In an exemplary embodiment, for convenience, component placement regions A1 to A4 are positioned above the upper surface of the substrate 10.

[0046] Multiple MR elements 50 are arranged separately in element arrangement regions A1 to A4. The multiple MR elements 50 constituting the first resistive section R1 are arranged in element arrangement region A1. The multiple MR elements 50 constituting the second resistive section R2 are arranged in element arrangement region A2. The multiple MR elements 50 constituting the third resistive section R3 are arranged in element arrangement region A3. The multiple MR elements 50 constituting the fourth resistive section R4 are arranged in element arrangement region A4.

[0047] exist Figure 1In the example shown, component configuration area A2 is positioned in front of component configuration area A1 in the X direction. Component configuration area A3 is positioned in front of component configuration area A2 in the -Y direction. Component configuration area A4 is positioned in front of component configuration area A3 in the -X direction and in front of component configuration area A1 in the -Y direction.

[0048] Furthermore, the arrangement of power supply terminal 11, ground terminal 12, first output terminal 13, second output terminal 14, and component arrangement areas A1 to A4 (first to fourth resistor sections R1 to R4) is not limited to... Figure 1 The example shown. For instance, component configuration areas A1 to A4 can also be configured in any order along a direction parallel to the X direction or parallel to the Y direction.

[0049] Next, refer to Figure 3 and Figure 4 The specific structures of the first to fourth resistor sections R1 to R4 will be described in detail. Here, the first resistor section R1 will be used as an example for explanation. Figure 3 This is a top view showing a portion of the first resistor section R1. Figure 4 This is a top view showing a portion of a column of components. Figure 3 and Figure 4 In the diagram, multiple circles represent multiple MR elements 50.

[0050] The first resistor section R1 may also include multiple element rows 55. Each element row 55 may also include wiring 40 and multiple MR elements 50 connected in series via wiring 40. The multiple element rows 55 may be connected in series or connected in parallel via two terminals (not shown).

[0051] Wiring 40 includes a plurality of lower electrodes 41 and a plurality of upper electrodes 42. Each lower electrode 41 has an elongated shape. A gap is formed between two adjacent lower electrodes 41 spaced apart. On the upper surface of the lower electrode 41, MR elements 50 are respectively disposed near both ends in the long side direction of the lower electrode 41. Each upper electrode 42 has an elongated shape and is configured to overlap with two adjacent MR elements 50 disposed on two adjacent lower electrodes 41 spaced apart when viewed from the Z direction.

[0052] exist Figure 3 and Figure 4In the example shown, at least a portion of each of the plurality of element rows 55 extends in a direction parallel to the X direction. Therefore, in at least a portion of each of the plurality of element rows 55, a plurality of MR elements 50 are arranged in a direction parallel to the X direction. Additionally, in at least a portion of each of the plurality of element rows 55, a plurality of lower electrodes 41 and a plurality of upper electrodes 42 each have a shape that is longer in a direction parallel to the X direction.

[0053] Furthermore, the shapes of the multiple element columns 55 are not limited to Figure 3 and Figure 4 The example shown. For instance, the multiple element columns 55 may also extend in any direction other than the direction parallel to the X direction. Alternatively, the multiple element columns 55 may each comprise multiple portions extending in mutually different directions.

[0054] Up to this point, the explanation has taken the first resistor R1 as an example. The above explanation regarding the first resistor R1 also applies to the second to fourth resistors R2 to R4.

[0055] Next, refer to Figure 5 and Figure 6 The structure of MR element 50 is described. Figure 5 This is a three-dimensional view of MR element 50. Figure 6 This is a top view showing the free layer of MR element 50.

[0056] The MR element 50 includes a magnetized fixed layer 51 with a fixed magnetization 51m, a free layer 53, and a gap layer 52 disposed between the magnetized fixed layer 51 and the free layer 53. The free layer 53 can be selected in terms of material and shape to have a magnetic vortex structure (also known as an eddy current structure). The gap layer 52 is a tunnel barrier layer or a non-magnetic conductive layer.

[0057] The free layer 53 has a cylindrical or approximately cylindrical shape. Furthermore, the free layer 53 has a magnetization 53m that forms a vortex around the center 53c of the magnetic vortex structure. In the absence of a magnetic field applied to the MR element 50, the center 53c of the magnetic vortex structure is aligned with or approximately aligned with the axis of the cylinder. The center 53c of the magnetic vortex structure in the free layer 53 can move according to the target magnetic field MF. Furthermore, in Figure 5 and Figure 6 In the example shown, the MR element 50 is cylindrical in shape.

[0058] The center 53c of the magnetic vortex structure moves when a component of the target magnetic field MF orthogonal to the Z direction is applied to the free layer 53. Within the range of variation in the intensity of this component, the free layer 53 preferably does not become magnetically saturated.

[0059] In an exemplary embodiment, the magnetization 51m of the magnetization fixing layer 51 includes a component in a direction parallel to the X direction. Furthermore, if the magnetization 51m of the magnetization fixing layer 51 includes a component in a specific direction, that specific direction component may also be the principal component of the magnetization 51m of the magnetization fixing layer 51. In an exemplary embodiment, if the magnetization 51m of the magnetization fixing layer 51 includes a component in a specific direction, the direction of the magnetization 51m of the magnetization fixing layer 51 becomes a specific direction or a substantially specific direction.

[0060] The MR element 50 may further include an antiferromagnetic layer. The antiferromagnetic layer, made of an antiferromagnetic material, generates exchange coupling with the magnetization fixation layer 51, fixing the direction of magnetization 51m of the magnetization fixation layer 51. Alternatively, the magnetization fixation layer 51 may also be a so-called self-pinned fixation layer (SFP layer). A self-pinned fixation layer has a stacked ferristructure consisting of a stacked ferromagnetic layer, a non-magnetic intermediate layer, and a ferromagnetic layer, where the two ferromagnetic layers are antiferromagnetically coupled.

[0061] Here, taking the case where the magnetization direction of the magnetization 51m of the magnetization fixation layer 51 is the -X direction as an example, the resistance value of the MR element 50 will be explained. Figure 7 and Figure 8 The term "free layer 53" refers to the free layer 53 when the magnetic field component MFx in the direction parallel to the X direction of the object magnetic field MF is applied.

[0062] Figure 7 This represents the free layer 53 when the direction of the magnetic field component MFx is in the X direction. In this case, the center 53c of the magnetic vortex structure moves through the magnetic field component MFx, and the amount of magnetization 53m in the X direction is greater than the amount of magnetization 53m in the -X direction. In this case, the resistance value of the MR element 50 increases.

[0063] Figure 8 This represents the free layer 53 when the direction of the magnetic field component MFx is in the -X direction. In this case, the center 53c of the magnetic vortex structure moves through the magnetic field component MFx, and the amount of magnetization 53m in the -X direction is greater than the amount of magnetization 53m in the X direction. In this case, the resistance value of the MR element 50 decreases.

[0064] The change in resistance of MR element 50 depends on the strength of the magnetic field component MFx. When the direction of the magnetic field component MFx is the X direction, as the strength of the magnetic field component MFx increases, the amount of magnetization 53m in the X direction increases. The resistance of MR element 50 increases with the increase in the amount of magnetization 53m in the X direction. Conversely, when the direction of the magnetic field component MFx is the -X direction, as the strength of the magnetic field component MFx increases, the amount of magnetization 53m in the -X direction increases. The resistance of MR element 50 decreases with the increase in the amount of magnetization 53m in the -X direction. When the strength of the magnetic field component MFx increases, the resistance of MR element 50 changes in the direction in which its increase or decrease both increase. When the strength of the magnetic field component MFx decreases, the resistance of MR element 50 changes in the direction in which its increase or decrease both decrease. In exemplary embodiments, the relationship between the strength of the magnetic field component MFx and the resistance of MR element 50 is linear or substantially linear, provided that the technical requirement of unsaturation of the free layer 53 is met.

[0065] Next, refer to Figure 9 The relationship between the strength of the magnetic field component MFx and the overall magnetization of the free layer 53 is explained. Figure 9 This is a characteristic diagram schematically showing the relationship between the strength of the magnetic field component MFx and the overall magnetization of the free layer 53. Figure 9 In the diagram, the horizontal axis represents the strength Hx of the magnetic field component MFx, and the vertical axis represents the magnitude Mx of the overall magnetization of the free layer 53. Figure 9 In the diagram, a positive value represents the intensity Hx when the direction of the magnetic field component MFx is the X direction, and a negative value represents the intensity Hx when the direction of the magnetic field component MFx is the -X direction. When the direction of the magnetic field component MFx is the X direction, as the amount of magnetization 53m in the X direction increases, the magnitude Mx of the overall magnetization of the free layer 53 increases. When the direction of the magnetic field component MFx is the -X direction, as the amount of magnetization 53m in the -X direction increases, the magnitude Mx of the overall magnetization of the free layer 53 decreases.

[0066] First, let's explain the case where the intensity Hx is increased from 0. As the intensity Hx is gradually increased from 0, the magnitude of magnetization Mx gradually increases. When the intensity Hx becomes greater than or equal to Hx1, the magnitude of magnetization Mx becomes constant, and the free layer 53 becomes magnetically saturated.

[0067] Next, the case where the intensity Hx is decreased from 0 will be explained. As the intensity Hx is gradually decreased from 0, the magnitude of magnetization Mx also gradually decreases. When the intensity Hx becomes below Hx2, the magnitude of magnetization Mx becomes constant, and the free layer 53 becomes magnetically saturated.

[0068] like Figure 9As shown, within a specific range where the intensity Hx is greater than Hx2 and less than Hx1, the magnitude of magnetization Mx changes linearly with respect to the intensity Hx. Furthermore, "linearly" means that in the characteristic graph representing the relationship between intensity Hx and the magnitude of magnetization Mx, the magnitude of magnetization Mx changes linearly or approximately linearly with respect to the intensity Hx.

[0069] In an exemplary embodiment, within the range of variation of intensity Hx, it is preferable that the free layer 53 does not become magnetically saturated, and more preferably the magnitude of magnetization Mx varies linearly with respect to the variation of intensity Hx.

[0070] Furthermore, after the intensity Hx is greater than the value Hx1 and the free layer 53 is magnetically saturated, when the intensity Hx is reduced from a value Hx3 (which is greater than Hx1) to a value Hx4 (which is less than Hx1), the magnitude of magnetization Mx remains almost unchanged. When the intensity Hx is less than Hx4, similar to the case where the intensity Hx is varied within a specific range where the intensity Hx is greater than Hx2 and less than Hx1, the magnitude of magnetization Mx changes linearly with respect to the intensity Hx.

[0071] Similarly, after the ratio of intensity Hx to Hx2 decreases and the free layer 53 becomes magnetically saturated, increasing the intensity Hx from a value Hx5 (smaller than the ratio Hx2) until it reaches a value Hx6 (larger than the ratio Hx2) results in almost no change in the magnitude of magnetization Mx. When the ratio of intensity Hx to Hx6 is large, similar to the case where the intensity Hx varies within a specific range where the ratio Hx2 is large and the ratio Hx1 is small, the magnitude of magnetization Mx changes linearly relative to the change in intensity Hx.

[0072] Although not illustrated, the relationship between intensity Hx and the resistance of MR element 50 is the same as the relationship between intensity Hx and the overall magnetization of free layer 53.

[0073] Next, refer to Figure 2 The directions of the magnetization 51m of the magnetization fixing layer 51 in each of the first to fourth resistive sections R1 to R4 will be explained. In the first resistive section R1, the magnetization 51m of the magnetization fixing layer 51 of each of the plurality of MR elements 50 includes a component of a first magnetization direction. In the second resistive section R2, the magnetization 51m of the magnetization fixing layer 51 of each of the plurality of MR elements 50 includes a component of a second magnetization direction opposite to the first magnetization direction. In the third resistive section R3, the magnetization 51m of the magnetization fixing layer 51 of each of the plurality of MR elements 50 includes a component of the first magnetization direction. In the fourth resistive section R4, the magnetization 51m of the magnetization fixing layer 51 of each of the plurality of MR elements 50 includes a component of the second magnetization direction. Figure 2 In the diagram, two arrows depicting the first and third resistive sections R1 and R3 respectively indicate the first magnetization direction. Figure 2In the diagram, two arrows depicting the second and fourth resistive sections R2 and R4 respectively indicate the second magnetization direction. In an exemplary embodiment, the first magnetization direction is specifically the X direction, and the second magnetization direction is the -X direction.

[0074] Next, refer to Figure 2 At least one detection signal generated by the magnetic sensor 1 will be explained. When the direction of the magnetic field component MFx is the X direction, compared with the state where the magnetic field component MFx is absent, the resistance values ​​of each of the plurality of MR elements 50 in the first and third resistive sections R1 and R3 decrease, while the resistance values ​​of each of the plurality of MR elements 50 in the second and fourth resistive sections R2 and R4 increase. As a result, the resistance values ​​of each of the first and third resistive sections R1 and R3 decrease, while the resistance values ​​of each of the second and fourth resistive sections R2 and R4 increase.

[0075] When the direction of the magnetic field component MFx is in the -X direction, the change in resistance value of the first to fourth resistive parts R1 to R4 is opposite to that when the direction of the magnetic field component MFx is in the X direction.

[0076] Thus, when the direction and intensity of the magnetic field component MFx change, the resistance values ​​of the first to fourth resistors R1 to R4 change such that the resistance values ​​of the first and third resistors R1 and R3 increase while the resistance values ​​of the second and fourth resistors R2 and R4 decrease, or the resistance values ​​of the first and third resistors R1 and R3 decrease while the resistance values ​​of the second and fourth resistors R2 and R4 increase. Consequently, the potential at the connection point of the first and second resistors R1 and R2 (i.e., the potential of the first output terminal 13) and the potential at the connection point of the third and fourth resistors R3 and R4 (i.e., the potential of the second output terminal 14) change. The magnetic sensor 1 may also generate a signal corresponding to the potential of the first output terminal 13 and a signal corresponding to the potential of the second output terminal 14 as detection signals, respectively. Alternatively, the magnetic sensor 1 may also generate a signal corresponding to the potential difference between the first output terminal 13 and the second output terminal 14 as a detection signal. In this case, the magnetic sensor 1 may further include a differential amplifier (differential detector) that outputs a signal corresponding to the potential difference between the first output terminal 13 and the second output terminal 14 as a detection signal.

[0077] Next, a method for manufacturing a magnetic sensor 1 according to an exemplary embodiment will be briefly described. The method for manufacturing a magnetic sensor 1 includes a step of forming a plurality of MR elements 50 on a substrate 10. In the step of forming the plurality of MR elements 50, firstly, a plurality of initial MR elements that will later become the plurality of MR elements 50 are formed. Each of the plurality of initial MR elements includes at least an initial magnetization fixing layer that will later become a magnetization fixing layer 51, a free layer 53, and a gap layer 52.

[0078] Next, using a laser and an external magnetic field in a specific direction, the magnetization direction of the initial magnetization fixing layer is fixed to the aforementioned specific direction. For example, among the multiple initial MR elements of the multiple MR elements 50 that will later become the first and third resistive sections R1 and R3, a laser is applied to the multiple initial MR elements while an external magnetic field in the first magnetization direction (X direction) is applied. If the initial MR element contains an antiferromagnetic layer, the laser is applied such that the temperature of the multiple initial MR elements irradiated with the laser is above the blocking temperature of the antiferromagnetic layer. The temperature of the multiple initial MR elements can be adjusted, for example, by the intensity and pulse width of the laser. After laser irradiation, when the temperature of the multiple initial MR elements is below the blocking temperature, the magnetization direction of the initial magnetization fixing layer is fixed to the first magnetization direction. Thus, the initial magnetization fixing layer becomes the magnetization fixing layer 51, and the multiple initial MR elements become the multiple MR elements 50 of the first and third resistive sections R1 and R3.

[0079] Furthermore, among the other initial MR elements that subsequently become the second and fourth resistive sections R2 and R4, by setting the direction of the external magnetic field to the second magnetization direction (-X direction), the magnetization direction of the initial magnetization fixing layer of each of the other initial MR elements can be fixed to the second magnetization direction. In this way, the multiple MR elements 50 forming the second and fourth resistive sections R2 and R4 are formed.

[0080] Next, the direction of magnetization 53m of the free layer 53 and the characteristics based on the direction of magnetization 53m will be explained with reference to FIG10. Here, the case in which the magnetization 51m of the magnetized fixed layer 51 includes a component of the first magnetization direction, i.e., the X direction, will be used as an example. Figure 10A This is an explanatory diagram schematically showing the magnetization of a portion of the magnetization fixing layer 51. Figure 10B and Figure 10C This is an illustrative diagram schematically representing the magnetization 53m of the free layer 53.

[0081] like Figure 10B and Figure 10C As shown, there are two stable states in the free layer 53. Figure 10B The free layer 53 shown can also be viewed from the Z direction, the stacking direction of the magnetized fixed layer 51 and the free layer 53. The direction of magnetization 53m is along the first direction around the center 53c of the magnetic vortex structure. Figure 10B It is stable in the counterclockwise direction. Figure 10C The free layer 53 shown can also be viewed from the Z direction, with the magnetization 53m in a second direction that is opposite to the first direction and surrounds the center 53c of the magnetic vortex structure. Figure 10CThe free layer 53 is stable in the clockwise direction. Hereinafter, the state of the free layer 53 when it is stable in the first direction along the magnetization direction 53m of the free layer 53 will be referred to as the first state, and the state of the free layer 53 when it is stable in the second direction along the magnetization direction 53m of the free layer 53 will be referred to as the second state.

[0082] but, Figure 10A This indicates that the magnetization 51m of the magnetization fixed layer 51 includes a component with a first magnetization direction, namely the X direction. Ideally, when the direction of the magnetization 51m of the entire magnetization fixed layer 51 is the X direction, the direction of the magnetization 51ma in each of the multiple local portions of the magnetization fixed layer 51 should also be the X direction. However, in reality, due to deviations in the crystallization state, crystal magnetic anisotropy, or shape magnetic anisotropy at the interface, the direction of the magnetization 51ma is dispersed to some extent. Therefore, the magnetization 51m of the magnetization fixed layer 51 actually contains multiple components with different directions. Furthermore, when the direction of the magnetization 51ma is dispersed, the resistance value of the MR element 50 may differ depending on whether the stable state of the free layer 53 is in the first or second state.

[0083] Additionally, sometimes an external magnetic field that is not the magnetic field of the object being detected is temporarily applied to the magnetic sensor 1, i.e., an external magnetic field that saturates the free layer 53. After such an external magnetic field is applied, the magnetization 53m of the free layer 53 can be directed in any direction between the first and second directions. That is, after such an external magnetic field is applied, sometimes the stable state of the free layer 53 changes from one of the first and second states to the other.

[0084] Figure 11 This is an explanatory diagram showing the relationship between the intensity Hx of the magnetic field component MFx and the resistance value of the MR element 50. Figure 11 In the diagram, the horizontal axis represents the strength Hx of the magnetic field component MFx, and the vertical axis represents the resistance R of the MR element 50. Additionally, in... Figure 11 In the diagram, the arrows indicate the tendency of the resistance value to change when the intensity Hx is altered. Figure 11 The diagram schematically illustrates the resistance value of the MR element 50 when the stable state of the free layer 53 changes from one of the first and second states to the other after increasing the intensity Hx until the free layer 53 becomes magnetically saturated and then decreasing the intensity Hx. For example... Figure 11 As shown, the resistance value of MR element 50 varies with the stable state of free layer 53 when MR element 50 has the same strength Hx.

[0085] Here, the resistance change ΔR is defined as a parameter corresponding to the resistance value change characteristic. The resistance change ΔR is a parameter defined for each MR element 50. In an exemplary embodiment, when the strength Hx of the magnetic field component MFx is set to a specific strength (e.g., zero), the resistance change ΔR is the value obtained by subtracting the resistance value when the free layer 53 is in a state other than the current state (e.g., the first state) (e.g., the second state) from the current resistance value.

[0086] Ideally, the resistance change ΔR should be zero. However, due to the dispersion of the magnetization direction 51ma mentioned above, the resistance change ΔR is sometimes not zero. Furthermore, the dispersion of the magnetization direction 51ma may vary for each MR element 50. Therefore, the resistance change ΔR may sometimes differ for each MR element 50.

[0087] Figure 12 This is an explanatory graph showing the statistical distribution of the resistance change ΔR. In Figure 12 In the diagram, the horizontal axis represents the resistance change ΔR, and the vertical axis represents the number N of MR elements 50. Hereinafter, the MR element 50 in the first state of the free layer 53 will be referred to as the first MR element 50A, and the MR element 50 in the second state of the free layer 53 will be referred to as the second MR element 50B. Figure 12 In the figure, the curve labeled 81 represents the statistical distribution (first distribution) of the resistance change ΔR of the first group, which is a group of multiple first MR elements 50A. The curve labeled 82 represents the statistical distribution (second distribution) of the resistance change ΔR of the second group, which is a group of multiple second MR elements 50B. The curve labeled 83 represents the statistical distribution (third distribution) of the resistance change ΔR of the third group, which includes the first MR elements 50A and the second MR elements 50B.

[0088] like Figure 12 As shown, the statistical distribution of the first group of resistance changes ΔR is characterized by a first distribution 81 centered on a first value ΔR1. The statistical distribution of the second group of resistance changes ΔR is characterized by a second distribution 82 centered on a second value ΔR2. The first value ΔR1 can also be the average value of the resistance changes ΔR in the first group. Similarly, the second value ΔR2 can also be the average value of the resistance changes ΔR in the second group.

[0089] exist Figure 12 The example shown assumes that the first value ΔR1 is positive, and the second value ΔR2 is negative, and ΔR2 is equal to or approximately equal to -ΔR1. The following is based on... Figure 12 The assumptions shown are explained.

[0090] The third group, with its statistical distribution of resistance change ΔR, exhibits the characteristics of a third distribution 83 centered on a third value between the first value ΔR1 and the second value ΔR2. The third value can also be the average of the resistance change ΔR in the third group. The third value is a value smaller than (ideally, zero) the absolute values ​​of the first value ΔR1 | and the absolute values ​​of the second value ΔR2 |.

[0091] In an exemplary embodiment, the first to fourth resistor sections R1 to R4 are constructed based on the characteristics of the third group described above. The first to fourth resistor sections R1 to R4 each include a plurality of first MR elements 50A and a plurality of second MR elements 50B. The plurality of first MR elements 50A and the plurality of second MR elements 50B constituting the first resistor section R1 may also be located in the element configuration area A1 (see reference). Figure 1 They are configured and electrically connected in a mixed manner. In the first resistor section R1, the total number of the first MR element 50A and the plurality of second MR elements 50B can also be even.

[0092] The above description of the first resistor R1 also applies to the second to fourth resistors R2 to R4. If we replace the first resistor R1 and component placement area A1 in the above description of the first resistor R1 with the second resistor R2 and component placement area A2, then this becomes a description of the second resistor R2. Furthermore, if we replace the first resistor R1 and component placement area A1 in the above description of the first resistor R1 with the third resistor R3 and component placement area A3, then this becomes a description of the third resistor R3. Furthermore, if we replace the first resistor R1 and component placement area A1 in the above description of the first resistor R1 with the fourth resistor R4 and component placement area A4, then this becomes a description of the fourth resistor R4.

[0093] Next, the operation and effects of the magnetic sensor 1 in the exemplary embodiment will be explained. As described above, in the exemplary embodiment, a plurality of first MR elements 50A and a plurality of second MR elements 50B are electrically connected in the first to fourth resistive sections R1 to R4. Therefore, according to the exemplary embodiment, it is possible to suppress variations in characteristics caused by the direction of magnetization 53m of the free layer 53. This effect will be explained in detail below.

[0094] When an external magnetic field that temporarily saturates the free layer 53 is applied to a plurality of first MR elements 50A of the first resistor section R1, the following first, second, and third cases are assumed. The first case is when the stable state of the free layer 53 changes from a first state to a second state in all or almost all of the plurality of first MR elements 50A. In the first case, the stable state of the free layer 53 changes from a second state to a first state in all or almost all of the plurality of second MR elements 50B of the first resistor section R1. That is, in the first case, all or almost all of the plurality of first MR elements 50A are replaced by second MR elements 50B, and all or almost all of the plurality of second MR elements 50B are replaced by first MR elements 50A.

[0095] The second scenario involves a certain number of first MR elements 50A among a plurality of first MR elements 50A, where the stable state of the free layer 53 changes from a first state to a second state. In this second scenario, among the plurality of second MR elements 50B of the first resistor R1, in a number of second MR elements 50B that are the same as or approximately the same as the number of first MR elements 50A whose stable state of the free layer 53 changes from the first state to the second state, the stable state of the free layer 53 changes from the second state to the first state. That is, in this second scenario, the same number of first MR elements 50A and second MR elements 50B are used interchangeably.

[0096] The third case is where the stable state of the free layer 53 does not change from the first state in all or almost all of the plurality of first MR elements 50A. In the third case, the stable state of the free layer 53 does not change from the second state in all or almost all of the plurality of second MR elements 50B of the first resistor section R1.

[0097] As described above, in any of the first to third cases, ideally, the number of the plurality of first MR elements 50A and the plurality of second MR elements 50B remain unchanged or almost unchanged before and after the application of an external magnetic field that temporarily saturates the free layer 53, as a whole, in the first resistive section R1. In the exemplary embodiment, the stable state of the free layer 53 is controlled, and the number of the plurality of first MR elements 50A and the plurality of second MR elements 50B are controlled. Thus, in the exemplary embodiment, compared with the case where the stable state of the free layer 53 is not controlled, both the change in the number of the plurality of first MR elements 50A and the change in the number of the plurality of second MR elements 50B are reduced. Therefore, in the exemplary embodiment, the statistical distribution change of the resistance change ΔR of the plurality of first MR elements 50A and the plurality of second MR elements 50B constituting the first resistive section R1 is smaller before and after the application of an external magnetic field that temporarily saturates the free layer 53. Therefore, in the exemplary embodiment, before and after the temporary application of an external magnetic field that magnetically saturates the free layer 53, the average change in the resistance change ΔR of the plurality of first MR elements 50A and the plurality of second MR elements 50B constituting the first resistive section R1 also becomes smaller.

[0098] The average resistance change ΔR of the plurality of first MR elements 50A and the plurality of second MR elements 50B constituting the first resistive section R1 corresponds to the change in resistance value of the first resistive section R1 when an external magnetic field that temporarily saturates the free layer 53 is applied. Specifically, the change in resistance value of the first resistive section R1 decreases as the average resistance change ΔR decreases. Therefore, according to the exemplary embodiment, the change in resistance value of the first resistive section R1 can be reduced.

[0099] The above description of the first resistor R1 also applies to the second to fourth resistors R2 to R4. Therefore, according to the exemplary embodiment, the variation in the resistance values ​​of each of the second to fourth resistors R2 to R4 can be reduced.

[0100] Furthermore, according to the exemplary embodiment, the variation in the resistance values ​​of the first to fourth resistive sections R1 to R4 can be reduced. Therefore, the variation in at least one detection signal before and after the application of an external magnetic field that temporarily saturates the free layer 53 can be reduced; that is, the variation in at least one detection signal when the strength Hx of the magnetic field component MFx is at a specific strength. Thus, according to the exemplary embodiment, the variation in characteristics caused by the direction of magnetization 53m of the free layer 53 can be suppressed.

[0101] Furthermore, it is preferable that the number of MR elements 50 constituting each of the first to fourth resistive sections R1 to R4 is relatively large. Here, similar to the MR elements 50, the overall resistance value of any one of the first to fourth resistive sections R1 to R4 is also defined as the resistance change ΔR. Figure 13 This is an explanatory diagram showing the statistical distribution of the resistance change ΔR of a resistor section. The curve indicated by reference numeral 84 represents the distribution when the number of MR elements 50 in the resistor section is relatively small, while the curve indicated by reference numeral 85 represents the distribution when the number of MR elements 50 in the resistor section is relatively large. Compared to distribution 84, the width of distribution 85 is smaller. According to the so-called central limit theorem, as the number of MR elements 50 increases, the statistical distribution of the resistance change ΔR of a resistor section approaches a normal distribution centered at zero, and the standard deviation of the distribution decreases.

[0102] When the free layer 53 is not magnetically saturated when the intensity Hx of the magnetic field component MFx is within a first range, and the intensity Hx of the magnetic field component MFx varies within the first range, at least one detection signal varies within a second range. The number of MR elements 50 constituting each of the first to fourth resistive sections R1 to R4 is preferably, for example, a number whose variation in at least one detection signal before and after the application of an external magnetic field that temporarily saturates the free layer 53, i.e., when the intensity Hx of the magnetic field component MFx is at a specific intensity, is less than 5% of the difference between the maximum and minimum values ​​within the second range, and more preferably less than 1%.

[0103] Next, a method for controlling the stable state of the free layer 53 will be described. As described above, in an exemplary embodiment, a first MR element 50A, in which the stable state of the free layer 53 is a first state, and a second MR element 50B, in which the stable state of the free layer 53 is a second state, are mixed together. In an exemplary embodiment, the stable state of the free layer 53 is controlled by employing at least one of the multiple control methods described below.

[0104] First, refer to Figure 14 The first control method will be explained. Figure 14 This is a top view showing an example of the configuration of MR element 50. Figure 14 In the X-direction, two MR elements 50 are adjacent to each other with a gap D1, and a group of the two MR elements 50 is adjacent to each other with a gap D2. Additionally, in the Y-direction, two MR elements 50 are adjacent to each other with a gap D3.

[0105] In the first control method, the interval D1 is set as a distance at which the free layers 53 can magnetically couple and interact with each other. Thus, regardless of the stable state of the free layers 53 of the two MR elements 50, after temporarily applying an external magnetic field that magnetically saturates the free layers 53, the free layer 53 of one of the two MR elements 50 can be controlled to be in a first state, and the free layer 53 of the other of the two MR elements 50 can be controlled to be in a second state.

[0106] In the first control method, by further setting the interval D3 to be equal to or approximately equal to the interval D1, it is possible to control the system so that the stable states of two adjacent MR elements 50 in the Y direction are different from each other.

[0107] In an exemplary embodiment, the planar shapes of the free layer 53 and the MR element 50, when viewed from the stacking direction (Z direction) of the magnetized fixed layer 51 and the free layer 53, can also be circular or approximately circular. Here, the notation D represents the diameter of the planar shape of the MR element 50, and the notation T represents the size of the MR element 50, i.e., the film thickness, in the stacking direction. The interval D1 (interval D3) can also be an estimated interval or less based on the diameter D and the film thickness T. In addition, the estimated interval can also be the interval at which the free layers 53 interact with each other at least (the maximum interval at which the free layers 53 can magnetically couple with each other), that is, an interval where the strength of the magnetic field acting on the free layer 53 is several to ten times that of the Earth's magnetism. In one example, the estimated interval X can be expressed using the diameter D and the film thickness T, as shown in the following formula (1). Furthermore, in formula (1), the estimated interval X is set to be an interval where the strength of the magnetic field acting on the free layer 53 is 10 times that of the Earth's magnetism.

[0108]

[0109] As indicated by equation (1), the estimated interval X is proportional to the 2 / 3 power of the diameter D and the 1 / 3 power of the film thickness T. The interval D1 (interval D3) is preferably less than or equal to the estimated interval X. The interval D2 may be equal to or greater than the interval D1.

[0110] Next, refer to Figure 15 The second control method will be explained. Figure 15This is a top view of the free layer 53, which has an attached structure for controlling the direction of the magnetization 53m of the free layer 53. In the second control method, the first MR element 50A has a structure 531 for orienting the magnetization 53m of the free layer 53 toward a first direction. The second MR element 50B has a structure 532 for orienting the magnetization 53m of the free layer 53 toward a second direction. Structures 531 and 532 may also be at least one protruding structure attached to the outer edge of the free layer 53. Structures 531 and 532 may also satisfy the following technical requirement: when the planar shape of structure 531 is rotated 180° around the center 53c of the magnetic vortex structure, it becomes the planar shape of structure 532.

[0111] In the MR element 50 with structure 531, after temporarily applying an external magnetic field that magnetically saturates the free layer 53, the stable state of the free layer 53 can become a first state. In the MR element 50 with structure 532, after temporarily applying an external magnetic field that magnetically saturates the free layer 53, the stable state of the free layer 53 can become a second state.

[0112] Furthermore, the functions of structures 531 and 532 are not absolute; they can also be relative functions where the direction of magnetization of 53m is determined by the direction of the external magnetic field.

[0113] Next, refer to Figure 16 The third control method will be explained. Figure 16 This is a top view of a free layer 53 having a planar shape capable of controlling the direction of magnetization 53m of the free layer 53. In the third control method, the free layer 53 has a planar shape capable of controlling the direction of magnetization 53m of the free layer 53, that is, a planar shape that satisfies the following technical requirement. That is, in the third control method, the first MR element 50A and the second MR element 50B satisfy the following technical requirement: when the planar shape of the first MR element 50A is rotated 180° around the center 53c of the magnetic vortex structure, it becomes the planar shape of the second MR element 50B. Figure 16 In the example shown, the first MR element 50A and the second MR element 50B each have a pentagonal planar shape.

[0114] Furthermore, the planar shapes of the first MR element 50A and the second MR element 50B are not absolute functions, but can also be relative functions where the direction of magnetization 53m is determined by the direction of the external magnetic field. Additionally, the planar shapes of the first MR element 50A and the second MR element 50B can also be polygons other than pentagons (e.g., polygons of 24 or more).

[0115] Next, refer to Figure 17 The fourth control method will be explained. Figure 17This is a top view showing the first structure that controls the direction of magnetization 53m of the MR element 50 and the free layer 53. In the fourth control method, the magnetic sensor 1 may also have a first structure 70 that controls the direction of magnetization 53m of the free layer 53. The first structure 70 may also be a magnetic yoke made of magnetic material disposed between the two MR elements 50.

[0116] In the fourth control method, when an external magnetic field that temporarily saturates the free layer 53 is applied to the MR element 50 and the first structure 70, the first structure 70 is magnetized. Figure 17 The diagram illustrates an example of applying an external magnetic field in the Y direction. This generates a magnetic field from the first structure 70 that controls the direction of magnetization 53m of the free layer 53. Consequently, the stable state of the free layer 53 of one of the two MR elements 50 can be a first state, and the stable state of the free layer 53 of the other of the two MR elements 50 can be a second state.

[0117] Furthermore, the function of the first structure 70 is not absolute, but can also be a relative function where the direction of magnetization 53m is determined by the direction of the external magnetic field.

[0118] Next, refer to Figure 18 The fifth control method will be explained. Figure 18 This is a top view showing the second structure that controls the direction of the magnetization 53m of the MR element 50 and the free layer 53. In the fifth control method, the magnetic sensor 1 includes second structures 70A and 70B that control the direction of the magnetization 53m of the free layer 53. The second structure 70A is a magnetic yoke made of magnetic material and disposed around the free layer 53, and may also have a structure for orienting the magnetization 53m of the free layer 53 toward a first direction. The second structure 70B is a magnetic yoke made of magnetic material and disposed around the free layer 53, and has a structure for orienting the magnetization 53m of the free layer 53 toward a second direction. The second structures 70A and 70B may also satisfy the following technical requirement: when the planar shape of the second structure 70A is rotated 180° around the center 53c of the magnetic vortex structure, it becomes the planar shape of the second structure 70B.

[0119] Furthermore, the functions of the second structures 70A and 70B are not absolute, but can also be relative functions determined by the direction of the external magnetic field, which determines the direction of magnetization at 53m.

[0120] Next, refer to Figure 19 and Figure 20 The sixth control method will be explained. Figure 19 This is an explanatory diagram schematically showing the direction of the current flowing through the MR element 50. Figure 20This is an illustration schematically showing the magnetic field generated by the current flowing through the MR element 50. In an exemplary embodiment, the direction of the current I flowing through the MR element 50 is the Z direction from the lower electrode 41 to the upper electrode 42, and the -Z direction from the upper electrode 42 to the lower electrode 41.

[0121] When a current I in the Z direction flows into the MR element 50, a magnetic field Ha is generated in the MR element 50 due to the current I, that is, the first direction around the center 53c of the magnetic vortex structure when viewed from the Z direction. Figure 20 A magnetic field Ha (in the counterclockwise direction) is generated in the MR element 50 when a current I in the -Z direction is passed through it. This generates a magnetic field Hb in the MR element 50 due to the current I, i.e., a second direction (viewed from the Z direction) around the center 53c of the magnetic vortex structure, opposite to the first direction. Figure 20 The magnetic field Hb (clockwise direction) in the middle. In the sixth control method, the stable state of the free layer 53 can become the first state through the magnetic field Ha, and the stable state of the free layer 53 can become the second state through the magnetic field Hb.

[0122] In the sixth control method, in particular, the number of MR elements 50 in each of the first to fourth resistor sections R1 to R4 is set to an even number, and the number of MR elements 50 with current I flowing in the Z direction and the number of MR elements 50 with current I flowing in the -Z direction are set to be the same, so that the number of the first MR element 50A and the number of the second MR element 50B can be set to be the same.

[0123] In addition, in the sixth control method, the first MR element 50A and the second MR element 50B can be directly connected to a lower electrode 41, or the first MR element 50A and the second MR element 50B can be directly connected to an upper electrode 42.

[0124] [Variation Example]

[0125] Next, the first to third modifications of the magnetic sensor 1 according to the exemplary embodiment will be described. First, referring to... Figure 21 The first variation will be explained. Figure 21 This is a top view showing a first modified example of the magnetic sensor 1. In this first modified example, multiple lower electrodes 41 and multiple upper electrodes 42 are connected to multiple MR elements 50, so that the shape of the multiple MR elements 50, multiple lower electrodes 41, and multiple upper electrodes 42 when viewed from above is a meandering shape. Figure 21In the example shown, multiple lower electrodes 41 extend in a direction parallel to the Y direction, and multiple upper electrodes 42 extend in a direction parallel to the X direction. However, the extension directions of the multiple lower electrodes 41 and the multiple upper electrodes 42 are not limited to... Figure 21 The example shown can be achieved simply by extending along two intersecting directions.

[0126] Next, refer to Figure 22 The second variation will be explained. Figure 22 This is a top view showing a second modification of the magnetic sensor 1. In the second modification, multiple MR elements 50 are arranged such that the interval between two adjacent MR elements 50 in any direction is D4. Specifically, when viewed from the Z direction, multiple MR elements 50 are arranged such that the shape connecting the centroids of three MR elements 50 arranged at their closest positions forms an equilateral triangle. When comparing cases where the area of ​​the element arrangement region is set to be the same, according to the second modification, the number of MR elements can be increased by approximately 15% compared to the case where multiple elements are arranged in a grid pattern in both the direction parallel to the X direction and the direction parallel to the Y direction.

[0127] exist Figure 22 In the example shown, the lower electrode 41 extends in a direction parallel to the direction after rotating 60° from the X direction toward the Y direction. The upper electrode 42 extends in a direction parallel to the direction after rotating 30° from the Y direction toward the -X direction.

[0128] Next, refer to Figure 23 The third variation will be explained. Figure 23 This is a top view showing a third modification of the magnetic sensor 1. In this third modification, the plurality of MR elements 50 may also comprise multiple pairs, each pair comprising two MR elements 50. The multiple pairs are connected in series via multiple lower electrodes 41 and multiple upper electrodes 42. That is, the two MR elements 50 of each of the multiple pairs are connected in parallel via a lower electrode 41 and an upper electrode 42.

[0129] [Second Exemplary Implementation]

[0130] Next, refer to Figure 24 A second exemplary embodiment of this disclosure will be described. Figure 24 This is a side view showing the MR element and shielding in an exemplary embodiment. The magnetic sensor 1 in the exemplary embodiment may also include a shielding member 60 made of magnetic material. The shielding member 60 may also be configured to cover the first to fourth resistive portions R1 to R4 (see reference). Figure 1 The shielding element 60 can be a single magnetic body or a magnetic body divided into multiple magnetic bodies.

[0131] The shield 60 is configured to reduce the strength of the applied magnetic field applied to the multiple MR elements 50. Figure 24 An example of applying a magnetic field component MFx to magnetic sensor 1 is shown. Figure 24 In the example shown, a magnetic field component MFx is applied to magnetic sensor 1 in a decaying state.

[0132] Next, refer to Figure 25 The effect of shielding component 60 is explained. Figure 25 This is a characteristic graph showing the relationship between the intensity Hx of the magnetic field component MFx and the detection signal. Figure 25 In the diagram, the horizontal axis represents the intensity Hx, and the vertical axis represents the magnitude of the detected signal. Figure 25 In particular, the magnitude of the detection signal indicates the relationship between the first output terminal 13 and the second output terminal 14 (see reference). Figure 2 The potential difference dVout. Additionally, reference numeral 91 indicates the relationship between the intensity Hx and the detection signal when shielding member 60 is present, and reference numeral 92 indicates the relationship between the intensity Hx and the detection signal when shielding member 60 is absent.

[0133] like Figure 25 As shown, according to an exemplary embodiment, the shielding member 60 can be used to increase the range (first range) of the strength Hx of the magnetic field component MFx that can be changed without causing the free layer 53 to become magnetically saturated.

[0134] Other structures, functions, and effects in the exemplary embodiments are the same as in the first exemplary embodiment.

[0135] Furthermore, this disclosure is not limited to the exemplary embodiments described above, and various modifications are possible. For example, the configuration of the first to fourth resistor sections R1 to R4 is not limited to the examples shown in the exemplary embodiments, and is arbitrary, as long as the technical requirements of the claims are met.

[0136] As explained above, the magnetic sensor of one embodiment of the first aspect of this disclosure is configured to include a plurality of first magnetoresistive elements and a plurality of second magnetoresistive elements, and generates a detection signal by detecting the magnetic field of the detected object. The plurality of first magnetoresistive elements are electrically connected to the plurality of second magnetoresistive elements. Each of the plurality of first and second magnetoresistive elements includes a magnetization-fixed layer whose magnetization direction is fixed, and a free layer capable of having a magnetic vortex structure, wherein the center of the magnetic vortex structure can move according to the applied magnetic field, and has a resistance value variation characteristic where the resistance value changes according to the stable state of the magnetic vortex structure when the applied magnetic field strength is the same. The first group of the plurality of first magnetoresistive elements has a parameter corresponding to the resistance value variation characteristic, i.e., a statistical distribution of the resistance change, which is a first distribution centered on a first value. The second group of the plurality of second magnetoresistive elements has a statistical distribution of the resistance change, which is a second distribution centered on a second value different from the first value. The third group, which comprises multiple first magnetoresistive elements and multiple second magnetoresistive elements, has a statistical distribution of resistance change, which is characterized by a third distribution centered on a third value between the first and second values.

[0137] In a magnetic sensor according to one embodiment of this disclosure, the plurality of first magnetoresistive elements and the plurality of second magnetoresistive elements may each be configured such that the free layer does not become magnetically saturated when the strength of the magnetic field of the detected object is within a first range. When the strength of the magnetic field of the detected object changes within the first range, the detection signal may also change within a second range. The third group may also have the following characteristics: as the number of magnetoresistive elements included in the third group increases, the statistical distribution of the resistance change of the resistive portion formed by the electrical connection of the magnetoresistive elements included in the third group approaches a normal distribution, and the standard deviation of the distribution decreases. The number of magnetoresistive elements included in the third group is the number of the change in the detection signal before and after temporarily applying an external magnetic field that causes magnetic saturation of the free layer to the plurality of first magnetoresistive elements and the plurality of second magnetoresistive elements, i.e., the change in the detection signal when the strength of the magnetic field of the detected object is within a specific strength within the first range, is less than 5% of the difference between the maximum and minimum values ​​in the second range.

[0138] Furthermore, in a magnetic sensor according to one embodiment of this disclosure, the free layers of each of the plurality of first magnetoresistive elements can be stabilized in a state where, viewed from the stacking direction of the magnetized fixed layer and the free layers, the magnetization direction of the free layers is along a first direction around the center of the magnetic vortex structure. The free layers of each of the plurality of second magnetoresistive elements can also be stabilized in a state where, viewed from the stacking direction of the magnetized fixed layer and the free layers, the magnetization direction of the free layers is along a second direction opposite to the first direction around the center of the magnetic vortex structure. The magnetization of the free layers can also be directed in either the first or second direction after a temporary external magnetic field saturating the free layers is applied. Each of the plurality of first magnetoresistive elements can also have a first structure for magnetizing the free layers in the first direction. Each of the plurality of second magnetoresistive elements can also have a second structure for magnetizing the free layers in the second direction. The magnetic sensor of the first embodiment of this disclosure may further include: a plurality of structures configured to magnetize the free layers in either the first or second direction.

[0139] Furthermore, in the magnetic sensor of one embodiment of this disclosure, the third group may also include multiple element columns. Each of the multiple element columns may also include multiple magnetoresistive effect elements connected in series. The multiple element columns may also be connected in parallel. Additionally, the magnetic sensor of the first embodiment of this disclosure may also include electrodes. The multiple first magnetoresistive effect elements may also include specific first magnetoresistive effect elements directly connected to the electrodes. The multiple second magnetoresistive effect elements may also include specific second magnetoresistive effect elements directly connected to the electrodes.

[0140] In addition, in one embodiment of the magnetic sensor disclosed herein, the third group may also include multiple pairs of magnetoresistive effect elements connected in parallel.

[0141] Furthermore, in one embodiment of the magnetic sensor disclosed herein, the plurality of first magnetoresistive elements may also include specific first magnetoresistive elements. The plurality of second magnetoresistive elements may also include specific second magnetoresistive elements that are spaced apart from and adjacent to the specific first magnetoresistive elements. The planar shape of the free layer, viewed from the stacking direction of the magnetized fixed layer and the free layer, may also be circular. The specific first magnetoresistive element and the specific second magnetoresistive element may also each have a diameter of their planar shape viewed from the stacking direction and a dimension in the stacking direction, i.e., a film thickness. The spacing between the specific first magnetoresistive elements and the specific second magnetoresistive elements may also be an estimated spacing or less based on the diameter and film thickness.

[0142] Furthermore, the magnetic sensor of one embodiment of this disclosure may also include a substrate having a component configuration region. A plurality of first magnetoresistive elements and a plurality of second magnetoresistive elements may also be configured to coexist in the component configuration region.

[0143] Furthermore, in a magnetic sensor according to one embodiment of this disclosure, the total number of the plurality of first magnetoresistive effect elements and the plurality of second magnetoresistive effect elements may also be an even number.

[0144] Furthermore, in a magnetic sensor according to one embodiment of this disclosure, the number of magnetoresistive effect elements in the third group that carry current in one direction parallel to the stacking direction of the magnetized fixed layer and the free layer, and the number of magnetoresistive effect elements that carry current in the opposite direction, may also be the same.

[0145] Furthermore, in a magnetic sensor according to an embodiment of the first aspect of this disclosure, the magnetization of the magnetization fixing layer may also include multiple components with different directions.

[0146] In addition, the magnetic sensor of one embodiment of the present disclosure may further include a shielding member configured to reduce the strength of the applied magnetic field.

[0147] A magnetic sensor according to a second embodiment of this disclosure is configured to include multiple magnetoresistive elements and generate a detection signal by detecting the magnetic field of a target object. Each of the multiple magnetoresistive elements comprises a magnetized fixed layer whose magnetization direction is fixed, and a free layer capable of having a magnetic vortex structure, wherein the center of the magnetic vortex structure can move according to the applied magnetic field. Each element exhibits a resistance value variation characteristic where its resistance value changes according to the stable state of the magnetic vortex structure when the applied magnetic field strength is the same. The group of multiple magnetoresistive elements has a parameter corresponding to the resistance value variation characteristic, namely, a statistical distribution of the resistance change centered on a specific value. Each of the multiple magnetoresistive elements is configured such that, when the magnetic field strength of the target object is within a first range, the free layer does not magnetically saturate. When the magnetic field strength of the target object varies within the first range, the detection signal varies within a second range. The group has the following characteristics: as the number of multiple magnetoresistive elements increases, the statistical distribution of the resistance change of the resistive portion formed by the electrical connection of the multiple magnetoresistive elements approaches a normal distribution, and the standard deviation of the distribution decreases. The number of multiple magnetoresistive effect elements is the amount of change in the detection signal before and after a temporary external magnetic field that saturates the free layer is applied to the multiple magnetoresistive effect elements, that is, the amount of change in the detection signal when the strength of the magnetic field of the detected object is a specific strength within the first range is less than 5% of the difference between the maximum and minimum values ​​in the second range.

[0148] Based on the foregoing description, it is clear that various methods and variations of this disclosure can be implemented. Therefore, within the equivalent scope of the claims, this disclosure can be implemented even in ways other than the exemplary embodiments described above.

Claims

1. A magnetic sensor, characterized in that, It is a magnetic sensor configured to have multiple first magnetoresistive effect elements and multiple second magnetoresistive effect elements, and generates a detection signal by detecting the magnetic field of the object being detected. The plurality of first magnetoresistive effect elements are electrically connected to the plurality of second magnetoresistive effect elements. The plurality of first magnetoresistive effect elements and the plurality of second magnetoresistive effect elements each include a magnetization fixed layer whose magnetization direction is fixed, and a free layer that can have a magnetic vortex structure and whose center can move according to the applied magnetic field, and has a resistance value variation characteristic that varies according to the stable state of the magnetic vortex structure when the intensity of the applied magnetic field is the same. The first group of the plurality of first magnetoresistive effect elements has the characteristic that the statistical distribution of the resistance change, which is a parameter corresponding to the resistance value change characteristic, is a first distribution centered on a first value. The second group of the plurality of second magnetoresistive effect elements has the characteristic that the statistical distribution of the resistance change becomes a second distribution centered on a second value different from the first value. The third group, comprising the plurality of first magnetoresistive effect elements and the plurality of second magnetoresistive effect elements, has a statistical distribution of the resistance change that is centered on a third value between the first value and the second value.

2. The magnetic sensor according to claim 1, characterized in that, The plurality of first magnetoresistive effect elements and the plurality of second magnetoresistive effect elements are respectively configured such that when the strength of the magnetic field of the detected object is within a first range, the free layer does not magnetically saturate. When the strength of the magnetic field of the object being detected changes within the first range, the detection signal changes within the second range. The third group has the following characteristics: as the number of magnetoresistive effect elements included in the third group increases, the statistical distribution of the resistance change of the resistive portion formed by the electrical connection of the magnetoresistive effect elements included in the third group approaches a normal distribution, and the standard deviation of the distribution decreases. The number of magnetoresistive effect elements included in the third group is the number of the change in the detection signal before and after the application of an external magnetic field that saturates the free layer to the plurality of first magnetoresistive effect elements and the plurality of second magnetoresistive effect elements, where the magnetic field strength of the detection object is a specific strength within the first range, and the change in the detection signal is less than 5% of the difference between the maximum and minimum values ​​in the second range.

3. The magnetic sensor according to claim 1, characterized in that, The free layers of each of the plurality of first magnetoresistive effect elements are stable when viewed from the stacking direction of the magnetized fixed layer and the free layers, with the magnetization direction of the free layers along a first direction around the center of the magnetic vortex structure. The free layers of each of the plurality of second magnetoresistive effect elements are stable when viewed from the stacking direction of the magnetized fixed layer and the free layers, with the magnetization direction of the free layers along a second direction opposite to the first direction around the center of the magnetic vortex structure.

4. The magnetic sensor according to claim 3, characterized in that, The magnetization of the free layer can be directed in either the first direction or the second direction after a temporary external magnetic field that saturates the free layer is applied to it.

5. The magnetic sensor according to claim 3, characterized in that, The plurality of first magnetoresistive effect elements each have a first structure for orienting the magnetization of the free layer toward the first direction. The plurality of second magnetoresistive effect elements each have a second structure for oriented the magnetization of the free layer toward the second direction.

6. The magnetic sensor according to claim 3, characterized in that, It also includes: a plurality of structures, each configured to orient the magnetization of the free layer toward the first direction or the second direction.

7. The magnetic sensor according to claim 1, characterized in that, The third group contains multiple columns of components. The multiple element columns each contain multiple magnetoresistive effect elements connected in series.

8. The magnetic sensor according to claim 7, characterized in that, The multiple element columns are connected in parallel to each other.

9. The magnetic sensor according to claim 7, characterized in that, It also has electrodes. The plurality of first magnetoresistive effect elements includes specific first magnetoresistive effect elements that are directly connected to the electrodes. The plurality of second magnetoresistive effect elements includes specific second magnetoresistive effect elements that are directly connected to the electrodes.

10. The magnetic sensor according to claim 1, characterized in that, The third group comprises multiple pairs of magnetoresistive effect elements connected in parallel.

11. The magnetic sensor according to claim 1, characterized in that, The plurality of first magnetoresistive effect elements includes specific first magnetoresistive effect elements. The plurality of second magnetoresistive effect elements includes specific second magnetoresistive effect elements that are spaced apart from and adjacent to the specific first magnetoresistive effect element.

12. The magnetic sensor according to claim 11, characterized in that, When viewed from the stacking direction of the magnetized fixed layer and the free layer, the planar shape of the free layer is circular. The specific first magnetoresistive element and the specific second magnetoresistive element each have a diameter of planar shape when viewed from the stacking direction and a film thickness that is a dimension in the stacking direction. The spacing between the specific first magnetoresistive element and the specific second magnetoresistive element is a presumed spacing based on the diameter and the film thickness.

13. The magnetic sensor according to claim 1, characterized in that, It also has a substrate with a component configuration area. The plurality of first magnetoresistive effect elements and the plurality of second magnetoresistive effect elements are configured in a mixed manner in the element configuration region.

14. The magnetic sensor according to claim 1, characterized in that, The total number of the plurality of first magnetoresistive effect elements and the plurality of second magnetoresistive effect elements is an even number.

15. The magnetic sensor according to claim 1, characterized in that, The number of magnetoresistive effect elements in the third group that carry current in one direction parallel to the stacking direction of the magnetized fixed layer and the free layer is the same as the number of magnetoresistive effect elements that carry current in the opposite direction.

16. The magnetic sensor according to claim 1, characterized in that, The magnetization of the magnetized fixing layer comprises multiple components with different directions.

17. The magnetic sensor according to claim 1, characterized in that, It also includes a shielding element configured to reduce the strength of the applied magnetic field.

18. A magnetic sensor, characterized in that, It is a magnetic sensor configured with multiple magnetoresistive elements, which generates a detection signal by detecting the magnetic field of the object being detected. The plurality of magnetoresistive elements each include a magnetized fixed layer whose magnetization direction is fixed, and a free layer that can have a magnetic vortex structure and whose center can move according to the applied magnetic field. Furthermore, they possess a resistance value variation characteristic where, for the same applied magnetic field strength, the resistance value changes according to the stable state of the magnetic vortex structure. The group of multiple magnetoresistive elements has a statistical distribution of resistance change, which is a parameter corresponding to the resistance value change characteristic, and this distribution is centered around a specific value. The plurality of magnetoresistive elements are respectively configured such that when the strength of the magnetic field of the detected object is within a first range, the free layer does not become magnetically saturated. When the strength of the magnetic field of the object being detected varies within the first range, the detection signal varies within the second range. The group has the following characteristics: as the number of the plurality of magnetoresistive effect elements increases, the statistical distribution of the resistance change of the resistive portion formed by the electrical connection of the plurality of magnetoresistive effect elements approaches a normal distribution, and the standard deviation of the distribution decreases. The number of the plurality of magnetoresistive effect elements is the amount of change in the detection signal before and after the application of an external magnetic field that temporarily saturates the free layer to the plurality of magnetoresistive effect elements. The amount of change in the detection signal when the strength of the magnetic field of the detection object is a specific strength within the first range is less than 5% of the difference between the maximum and minimum values ​​in the second range.

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