magnetic sensor

Abstract

A magnetic sensor according to the present application includes an MR element and a support member. The support member has a facing surface including a first inclined portion and a lower surface. In any cross section, the first inclined portion is inclined at a first angle at a first position, and the first inclined portion is inclined at a second angle smaller than the first angle at a second position. An absolute value of a curvature of the first inclined portion at the first position is smaller than an absolute value of a curvature of the first inclined portion at the second position. The MR element is disposed on the first inclined portion in such a manner that a first end portion is located above the first position in any cross section.

Description

Technical Field

[0001] This invention relates to a magnetic sensor having a magnetoresistive element. Background Technology

[0002] In recent years, magnetic sensors utilizing magnetoresistive elements have been employed for various applications. In systems incorporating magnetic sensors, it is sometimes desirable to detect a magnetic field component that includes a direction perpendicular to the surface of the substrate using a magnetoresistive element mounted on a substrate. In this case, by incorporating a soft magnetic material that transforms the magnetic field perpendicular to the surface of the substrate into a magnetic field parallel to the surface of the substrate, or by placing the magnetoresistive element on an inclined surface formed on the substrate, it is possible to detect a magnetic field component that includes a direction perpendicular to the surface of the substrate.

[0003] Chinese Invention Patent Application Publication No. 101142494A discloses a first magnetic sensor and a second magnetic sensor, each having an X-axis sensor, a Y-axis sensor, and a Z-axis sensor disposed on a substrate. In the first magnetic sensor, a V-shaped groove is formed in a thick film on the substrate. At a flat location in the central portion of the inclined surface of this groove, a strip-shaped portion serving as a giant magnetoresistive element for the Z-axis sensor is disposed. This strip-shaped portion, which forms the main body of the giant magnetoresistive element, has an elongated, planar shape.

[0004] In the second magnetic sensor, a V-shaped groove with a first and a second inclined plane is formed on a thick film on a substrate. The second inclined plane forms the lower half of the inclined plane of the groove. The angle between the second inclined plane and the substrate is greater than the angle between the first inclined plane and the substrate. At a position with good flatness in the central part of the second inclined plane, a strip-shaped portion serving as a giant magnetoresistive element for a Z-axis sensor is provided. The strip-shaped portion has an elongated, planar shape.

[0005] In addition, Chinese invention patent application publication No. 101142494A describes that the inclined surface is actually a slightly outward-protruding curved surface in the manufacturing process.

[0006] Generally, magnetoresistive elements are formed by etching a stack of films that will become magnetoresistive elements using ion milling or reactive ion etching. In this etching process, a photoresist mask is used. The photoresist mask is formed at the desired location on the stacked films using photolithography. Furthermore, the photoresist mask has a planar shape corresponding to the planar shape of the magnetoresistive element. However, due to the precision of photolithography, deviations in the position and size of the photoresist mask may occur.

[0007] The effects of deviations in the position and size of the photoresist mask become significant when forming magnetoresistive elements on curved surfaces. Typically, when forming magnetoresistive elements on curved surfaces, so-called irregular film deposition apparatuses such as magnetron sputtering are used to form a stacked film in a curved surface configuration. Therefore, the thickness of the stacked film (the dimension in the direction perpendicular to the curved surface) decreases as the tilt angle of the curved surface increases.

[0008] In a curved surface of this protruding shape, the change in tilt angle when the position on the curved surface varies horizontally at predetermined intervals increases with distance from the top of the curved surface. Similarly, the change in the thickness of the stacked film also increases with distance from the top of the curved surface. Therefore, when the position or size of the photoresist mask changes, and the position of the wall of the photoresist mask located on the opposite side of the top of the curved surface changes, the thickness of the magnetoresistive element near the end located on the opposite side of the top of the curved surface changes significantly. As a result, problems arise where desired characteristics cannot be obtained.

[0009] The above-mentioned problem also arises in the case where a magnetoresistive element is formed on a concave curved surface. Summary of the Invention

[0010] The purpose of this invention is to provide a magnetic sensor that can suppress changes in the thickness of the magnetoresistive element located on the inclined portion due to deviations in the manufacturing process.

[0011] The magnetic sensor of the present invention comprises: a magnetoresistive element whose resistance value changes according to an external magnetic field; and a support member supporting the magnetoresistive element. The support member has: a facing surface opposite to the magnetoresistive element; and a lower surface formed by planes disposed on opposite sides of the facing surface. The facing surface includes an inclined portion that is inclined relative to the lower surface. As a cross-section of the magnetic sensor, in a specific cross-section perpendicular to the lower surface, the inclined portion is inclined at a first position relative to the lower surface at a first angle, and at a second position relative to the lower surface at a second angle smaller than the first angle.

[0012] The absolute value of the curvature of the inclined portion at the first position is less than the absolute value of the curvature of the inclined portion at the second position. The magnetoresistive element has a first end and a second end located at both ends in the width direction of the magnetoresistive element, and is arranged on the inclined portion such that the first end is located above the first position in the above cross-section.

[0013] In the magnetic sensor of the present invention, a magnetoresistive element may also be disposed on the inclined portion such that the second end is located above the second position in the above-described cross-section.

[0014] Furthermore, in the magnetic sensor of the present invention, the first position and the second position may be located within a range from the third position on the inclined portion closest to the lower surface in the aforementioned cross-section to the fourth position on the inclined portion furthest from the lower surface in the aforementioned cross-section. In this case, the inclined portion may be inclined relative to the lower surface in such a way that the first angle is the largest and the second angle is the smallest within the range from the first position to the second position. Furthermore, the absolute value of the curvature of the inclined portion may be the smallest at the first position and the largest at a predetermined position other than the first position within the range from the first position to the second position.

[0015] Furthermore, in the magnetic sensor of the present invention, the opposing surface may include a convex surface protruding in a direction separating from the lower surface. In this case, the inclined portion may be part of the convex surface. Alternatively, the opposing surface may include a concave surface recessed in a direction closer to the lower surface. In this case, the inclined portion may be part of the concave surface.

[0016] Furthermore, in the magnetic sensor of the present invention, the magnetoresistive element may include a magnetized magnetic layer whose orientation can change according to an external magnetic field. The magnetic layer may also have a first surface and a second surface disposed on the opposite side of the first surface, and a film thickness that is a dimension perpendicular to the first surface of the magnetic layer. The film thickness at the first end may be smaller than the film thickness at the second end. Furthermore, the film thickness may decrease as it approaches the first end from the second end. Additionally, both the first and second surfaces may have a shape that is elongated in a direction intersecting the aforementioned cross-section.

[0017] In the magnetic sensor of the present invention, the inclined portion of the opposing surface of the support member is inclined at a first position at a first angle relative to the lower surface, and at a second position at a second angle relative to the lower surface at a smaller angle than the first angle. The absolute value of the curvature of the inclined portion at the first position is less than the absolute value of the curvature of the inclined portion at the second position. The magnetoresistive element is disposed on the inclined portion with its first end located above the first position. Therefore, according to the present invention, it is possible to suppress changes in the thickness of the magnetoresistive element due to manufacturing process deviations.

[0018] Other objects, features and effects of the present invention will become fully apparent from the following description. Attached Figure Description

[0019] Figure 1 This is an explanatory diagram showing a schematic structure of the magnetic sensor system according to the first embodiment of the present invention.

[0020] Figure 2 This is a circuit diagram showing the circuit structure of the magnetic sensor according to the first embodiment of the present invention.

[0021] Figure 3 This is a schematic diagram illustrating a portion of the magnetic sensor according to the first embodiment of the present invention.

[0022] Figure 4 This is a cross-sectional view showing a portion of the magnetic sensor according to the first embodiment of the present invention.

[0023] Figure 5 This is a top view showing a portion of the magnetic sensor according to the first embodiment of the present invention.

[0024] Figure 6 This is a cross-sectional view showing the magnetoresistive effect element in the first embodiment of the present invention.

[0025] Figure 7 This is an explanatory diagram illustrating the shape of the inclined portion in the first embodiment of the present invention.

[0026] Figure 8 This is a cross-sectional view showing one step of the manufacturing method of the magnetic sensor according to the first embodiment of the present invention.

[0027] Figure 9 It shows the next step. Figure 8 The diagram shows a cross-sectional view of the process.

[0028] Figure 10 It shows the next step. Figure 9 The diagram shows a cross-sectional view of the process.

[0029] Figure 11 It shows the next step. Figure 10 The diagram shows a cross-sectional view of the process.

[0030] Figure 12 It shows the next step. Figure 11 The diagram shows a cross-sectional view of the process.

[0031] Figure 13 This is a characteristic diagram showing the shape and curvature of the opposing surfaces of the support member according to the first embodiment of the present invention.

[0032] Figure 14 This is an explanatory diagram illustrating the magnetic charge of the magnetoresistive element in the comparative example.

[0033] Figure 15 This is an explanatory diagram illustrating the magnetic charge of the magnetoresistive effect element according to the first embodiment of the present invention.

[0034] Figure 16 This is a cross-sectional view showing a modified example of the magnetoresistive effect element according to the first embodiment of the present invention.

[0035] Figure 17This is a cross-sectional view showing a cross-section of the magnetic sensor according to the second embodiment of the present invention.

[0036] Figure 18 This is an explanatory diagram illustrating the shape of the inclined portion in the second embodiment of the present invention. Detailed Implementation

[0037] [First Implementation]

[0038] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. First, referring to... Figure 1 The general outline of a magnetic sensor system incorporating the magnetic sensor of the first embodiment of the present invention will be described below. The magnetic sensor system 100 of this embodiment includes: a magnetic sensor 1 of this embodiment; and a magnetic field generator 5 that generates a target magnetic field MF, which is the magnetic field (target magnetic field) that the magnetic sensor 1 should detect.

[0039] The magnetic field generator 5 is capable of rotating about a rotation axis C. The magnetic field generator 5 includes a pair of magnets 6A and 6B. Magnets 6A and 6B are arranged symmetrically about a virtual plane containing the rotation axis C. Each magnet 6A and 6B has a north pole and a south pole. Magnets 6A and 6B are arranged with the north pole of magnet 6A facing the south pole of magnet 6B. The magnetic field generator 5 generates an object magnetic field MF from the north pole of magnet 6A towards the south pole of magnet 6B.

[0040] Magnetic sensor 1 is positioned to detect the object magnetic field MF at a predetermined reference position. The object magnetic field MF at the reference position is a portion of the magnetic fields generated by magnets 6A and 6B respectively. The reference position can also be located on the rotation axis C. In the following description, the reference position is set on the rotation axis C. Magnetic sensor 1 detects the object magnetic field MF generated by magnetic field generator 5 and generates a detection value Vs. The detection value Vs corresponds to the relative position of magnetic field generator 5 with respect to magnetic sensor 1, particularly its rotational position.

[0041] The magnetic sensor system 100 can be used as a device to detect the rotational position of the movable part of a device having a rotatable movable part. Examples of such devices include the joints of industrial robots. Figure 1 An example of a magnetic sensor system 100 applied in an industrial robot 200 is shown.

[0042] Figure 1The industrial robot 200 shown includes: a movable part 201 and a support part 202 that supports the movable part 201 to allow it to rotate. The connection between the movable part 201 and the support part 202 is a joint. The movable part 201 rotates about a rotation axis C. When the magnetic sensor system 100 is applied to the joint of the industrial robot 200, for example, the magnetic sensor 1 can be fixed to the support part 202, and magnets 6A and 6B can be fixed to the movable part 201.

[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. In this embodiment, a direction parallel to the rotation axis C (in...) Figure 1 The direction from the inside towards the front is defined as the X direction. Figure 1 In this diagram, the Y direction is represented as the direction to the right, and the Z direction is represented as the direction upwards. Furthermore, the opposite direction of the X direction is defined as -X, the opposite direction of the Y direction as -Y, and the opposite direction of the Z direction as -Z. Additionally, below, the position in front of the reference position in the Z direction is referred to as "above," and the position opposite to "above" relative to the reference position is referred to as "below."

[0044] In this embodiment, the direction of the object magnetic field MF at the reference position is represented as the direction within the YZ plane, including the reference position on the rotation axis C. The direction of the object magnetic field MF at the reference position rotates within the aforementioned YZ plane about the reference position.

[0045] The magnetic sensor 1 includes a magnetoresistive element (hereinafter referred to as an MR element) whose resistance value changes according to an external magnetic field. In this embodiment, the resistance value of the MR element changes according to the direction of the target magnetic field MF. The magnetic sensor 1 generates a detection signal corresponding to the resistance value of the MR element, and generates a detection value Vs based on the detection signal.

[0046] Next, the structure of the magnetic sensor 1 in this embodiment will be described. First, referring to... Figure 2 An example of the circuit structure of magnetic sensor 1 will be explained. Figure 2 In the example shown, the magnetic sensor 1 includes: four resistive sections 11, 12, 13, and 14; two power supply terminals V1 and V2; two ground terminals G1 and G2; and two signal output terminals E1 and E2.

[0047] Each of the resistor sections 11 to 14 includes at least one MR element 30. When each of the resistor sections 11 to 14 includes multiple MR elements 30, the multiple MR elements 30 in each of the resistor sections 11 to 14 may also be connected in series.

[0048] Resistor 11 is disposed between power supply terminal V1 and signal output terminal E1. Resistor 12 is disposed between signal output terminal E1 and ground terminal G1. Resistor 13 is disposed between power supply terminal V2 and signal output terminal E2. Resistor 14 is disposed between signal output terminal E2 and ground terminal G2. A specified power supply voltage is applied to power supply terminals V1 and V2. Ground terminals G1 and G2 are grounded.

[0049] The potential at the connection point between resistor 11 and resistor 12 varies depending on the resistance value of at least one MR element 30 in resistor 11 and the resistance value of at least one MR element 30 in resistor 12. The signal output terminal E1 outputs a signal corresponding to the potential at the connection point between resistor 11 and resistor 12 as a detection signal S1.

[0050] The potential at the connection point between resistor 13 and resistor 14 varies depending on the resistance value of at least one MR element 30 in resistor 13 and the resistance value of at least one MR element 30 in resistor 14. The signal output terminal E2 outputs a signal corresponding to the potential at the connection point between resistor 13 and resistor 14 as a detection signal S2.

[0051] The magnetic sensor 1 also includes a detection value generation circuit 21 that generates a detection value Vs based on detection signals S1 and S2. The detection value generation circuit 21 is, for example, composed of an application-specific integrated circuit (ASIC) or a microcomputer.

[0052] Next, focusing on one MR element 30, the structure of the magnetic sensor 1 will be described in more detail. Figure 3 This is a schematic diagram showing a portion of the magnetic sensor 1. Figure 4 This is a cross-sectional view showing a portion of the magnetic sensor 1. Furthermore, Figure 4 The cross section is shown, which is parallel to the YZ plane and intersects with the MR element 30. Figure 5 This is a top view showing a portion of the magnetic sensor 1.

[0053] The magnetic sensor 1 also includes a support member 60. The support member 60 supports all the MR elements 30 contained in the resistive sections 11-14. For example... Figure 3 and Figure 4As shown, the support member 60 has: a facing surface 60a partially opposite to the MR element 30; and a lower surface 60b formed by a plane disposed on the opposite side of the facing surface 60a. The facing surface 60a is located at the end of the support member 60 in the Z direction. The lower surface 60b is located at the end of the support member 60 in the -Z direction. The lower surface 60b is parallel to the XY plane. The magnetic sensor 1 may, for example, be manufactured with the lower surface 60b or the surface corresponding to the lower surface 60b horizontally. Furthermore, the magnetic sensor 1 may, for example, be set based on the orientation or inclination of the lower surface 60b or the surface corresponding to the lower surface 60b. Thus, the lower surface 60b may also be a reference surface for at least one of the manufacturing and setting of the magnetic sensor 1.

[0054] The opposing surface 60a of the support member 60 includes an inclined portion that is inclined relative to the lower surface 60b. In this embodiment, the opposing surface 60a includes: a planar portion 60a1 parallel to the lower surface 60b, and at least one curved surface portion 60a2 not parallel to the lower surface 60b. Figure 4 As shown, the curved portion 60a2 is a convex surface protruding in a direction separating from the lower surface 60b. The aforementioned inclined portion is part of the convex surface. In any cross-section parallel to the YZ plane, the curved portion 60a2 has a curved shape (arch shape) that curves in a direction away from the lower surface 60b (Z direction). In any cross-section parallel to the YZ plane, the distance from the lower surface 60b to the curved portion 60a2 is greatest at the center of the curved portion 60a2 in a direction parallel to the Y direction (hereinafter simply referred to as the center of the curved portion 60a2).

[0055] The curved portion 60a2 extends along the X direction. For example... Figure 3 As shown, the overall shape of the curved surface portion 60a2 is... Figure 4 The curved shape shown (arch shape) is a semi-cylindrical surface formed by moving along the X direction.

[0056] MR element 30 is disposed on the curved surface portion 60a2. Here, the portion of the curved surface portion 60a2 from its end located at the -Y direction end to the center of the curved surface portion 60a2 is referred to as the first inclined portion, denoted by reference numeral SL1. Furthermore, the portion of the curved surface portion 60a2 from its end located at the Y direction end to the center of the curved surface portion 60a2 is referred to as the second inclined portion, denoted by reference numeral SL2. Figure 3 In the diagram, the boundary between the first inclined portion SL1 and the second inclined portion SL2 is indicated by a dashed line. Both the first inclined portion SL1 and the second inclined portion SL2 are inclined relative to the lower surface 60b. In this embodiment, the MR element 30 is disposed entirely on the first inclined portion SL1 or the second inclined portion SL2. Figure 3 and Figure 4 The MR element 30 is shown configured on the first inclined portion SL1.

[0057] The MR element 30 has a shape that is elongated in the X direction. Here, the direction of the shorter side of the MR element 30 is referred to as the width direction of the MR element 30, or simply the width direction. The planar shape of the MR element 30 (the shape viewed from the Z direction) can also be a shape like a rectangle, containing a constant width portion whose width dimension is constant or approximately constant regardless of its position in the X direction; or it can be a shape like an ellipse, not containing a constant width portion. Examples of planar shapes of the MR element 30 containing a constant width portion include, besides a rectangle with straight lines at both ends of the longer side, shapes with semicircles at both ends of the longer side, and shapes with polygons at both ends of the longer side. Figure 3 and Figure 5 The diagram shows an example where the planar shape of the MR element 30 is rectangular. In this example, the MR element 30 has: a lower surface 30a opposite to the curved surface portion 60a2, an upper surface 30b located on the opposite side of the lower surface 30a, a first end portion 30c and a second end portion 30d located at both ends in the width direction, and a third end portion 30e and a fourth end portion 30f located at both ends in the long side direction. The dimension in the width direction of the MR element 30 is constant or approximately constant regardless of its position in the X direction.

[0058] The support member 60 includes a substrate 61 and an insulating layer 62 disposed on the substrate 61. The substrate 61 is, for example, a semiconductor substrate made of a semiconductor such as Si. The substrate 61 has an upper surface at an end located in the Z direction and a lower surface at an end located in the -Z direction. The lower surface 60b of the support member 60 is formed by the lower surface of the substrate 61. The thickness (dimension in the Z direction) of the substrate 61 is constant.

[0059] The insulating layer 62 is made of an insulating material such as SiO2. The insulating layer 62 has an upper surface at its end in the Z direction. The opposing surface 60a of the support member 60 is formed by the upper surface of the insulating layer 62. The insulating layer 62 has a cross-sectional shape in which a curved portion 60a2 is formed on the opposing surface 60a. Specifically, the insulating layer 62 has a cross-sectional shape that protrudes in the Z direction in any cross-section parallel to the YZ plane.

[0060] The magnetic sensor 1 also includes: a lower electrode 41, an upper electrode 42, and insulating layers 63, 64, and 65. Furthermore, in... Figure 3 In this design, the lower electrode 41, the upper electrode 42, and the insulating layers 63-65 are omitted. Additionally, in... Figure 5 The insulation layers 63-65 are omitted in the text.

[0061] The lower electrode 41 is disposed on the opposite surface 60a (the upper surface of the insulating layer 62) of the support member 60. The insulating layer 63 is disposed around the lower electrode 41 on the opposite surface 60a of the support member 60. The MR element 30 is disposed on the lower electrode 41. The insulating layer 64 is disposed around the MR element 30 on the lower electrode 41 and the insulating layer 63. The upper electrode 42 is disposed on the MR element 30 and the insulating layer 64. The insulating layer 65 is disposed around the upper electrode 42 on the insulating layer 64.

[0062] The magnetic sensor 1 also includes an insulating layer (not shown) covering the upper electrode 42 and the insulating layer 65. The lower electrode 41 and the upper electrode 42 are formed, for example, of a conductive material such as Cu. The insulating layers 63-65 and the insulating layer (not shown) are formed, for example, of an insulating material such as SiO2.

[0063] Here, the substrate 61 and the portion stacked on the substrate 61 in the magnetic sensor 1 are collectively referred to as the detection unit. Figure 4 It can be said that the diagram includes a detection section. Figure 2 The detection value generation circuit 21 shown can be integrated with the detection unit or separate from the detection unit.

[0064] Here, refer to Figure 6 The structure of the MR element 30 will be described in detail below. In this embodiment, in particular, the MR element 30 is a spin valve type MR element. Figure 6 As shown, the MR element 30 includes: a magnetized fixed layer 32 with a fixed orientation, a free layer 34 with a magnetized orientation that can change according to the direction of the applied magnetic field, and a gap layer 33 disposed between the magnetized fixed layer 32 and the free layer 34. The MR element 30 can also be a TMR (tunneling magnetoresistance) element or a GMR (giant magnetoresistance) element. In a TMR element, the gap layer 33 is a tunnel barrier layer. In a GMR element, the gap layer 33 is a non-magnetic conductive layer. In the MR element 30, the resistance value changes according to the angle formed by the magnetization direction of the free layer 34 relative to the magnetization direction of the magnetized fixed layer 32; the resistance value is at its minimum when the angle is 0° and at its maximum when the angle is 180°.

[0065] The magnetization layer 32, the gap layer 33, and the free layer 34 are stacked sequentially from the lower electrode 41 side in the direction from the lower electrode 41 to the upper electrode 42. The MR element 30 also includes a base layer 31 between the magnetization layer 32 and the lower electrode 41, and a capping layer 35 between the free layer 34 and the upper electrode 42. Furthermore, the arrangement of the magnetization layer 32, the gap layer 33, and the free layer 34 of the MR element 30 can also be... Figure 6 The configuration shown is reversed from top to bottom.

[0066] The magnetization direction of the magnetization fixing layer 32 is preferably orthogonal to the long side direction of the MR element 30. In this embodiment, the MR element 30 is disposed on a first inclined portion SL1 or a second inclined portion SL2 that is inclined relative to the lower surface 60b. Therefore, the magnetization direction of the magnetization fixing layer 32 is also inclined relative to the lower surface 60b.

[0067] In this embodiment, for ease of explanation, the magnetization direction of the magnetization fixing layer 32 disposed on the first inclined portion SL1 is set to the U direction or the -U direction. The U direction is a direction rotated from the Y direction toward the Z direction by a predetermined angle. The -U direction is a direction opposite to the U direction. Furthermore, in this embodiment, for ease of explanation, the magnetization direction of the magnetization fixing layer 32 disposed on the second inclined portion SL2 is set to the V direction or the -V direction. The V direction is a direction rotated from the Y direction toward the -Z direction by a predetermined angle. The -V direction is a direction opposite to the V direction.

[0068] exist Figure 2 The X, U, and V directions are shown. Furthermore, in... Figure 2 For ease of explanation, the same arrow is used to indicate the U and V directions. Figure 2 In the diagram, solid arrows indicate the magnetization direction of the magnetization fixing layer 32 of the MR element 30 included in each of the resistor sections 11 to 14. The magnetic sensor 1 may also be configured such that the magnetization direction of the magnetization fixing layer 32 of the MR element 30 in resistor sections 11 and 14 is the U direction, and the magnetization direction of the magnetization fixing layer 32 of the MR element 30 in resistor sections 12 and 13 is the -U direction. Alternatively, the magnetic sensor 1 may also be configured such that the magnetization direction of the magnetization fixing layer 32 of the MR element 30 in resistor sections 11 and 14 is the V direction, and the magnetization direction of the magnetization fixing layer 32 of the MR element 30 in resistor sections 12 and 13 is the -V direction.

[0069] Alternatively, the magnetic sensor 1 may also include a first circuit portion and a second circuit portion, each comprising resistive portions 11 to 14. In the first circuit portion, the magnetization direction of the magnetization fixing layer 32 of the MR element 30 of the resistive portions 11 and 14 may be the U direction, and the magnetization direction of the magnetization fixing layer 32 of the MR element 30 of the resistive portions 12 and 13 may be the -U direction. In the second circuit portion, the magnetization direction of the magnetization fixing layer 32 of the MR element 30 of the resistive portions 11 and 14 may be the V direction, and the magnetization direction of the magnetization fixing layer 32 of the MR element 30 of the resistive portions 12 and 13 may be the -V direction.

[0070] The free layer 34 corresponds to the magnetic layer of the present invention. The free layer 34 has shape magnetic anisotropy where the easy magnetization axis direction intersects the magnetization direction of the magnetization fixed layer 32. In this embodiment, the MR element 30 is patterned into a shape that is elongated in the X direction. Therefore, the free layer 34 has shape magnetic anisotropy where the easy magnetization axis direction is parallel to the X direction.

[0071] Up to this point, the structure of the magnetic sensor 1 has been described with reference to a single MR element 30. In this embodiment, each of the resistive sections 11 to 14 includes at least one MR element 30. Therefore, the magnetic sensor 1 includes multiple MR elements 30, multiple lower electrodes 41, and multiple upper electrodes 42. Figure 5 As shown, each lower electrode 41 has an elongated shape. An MR element 30 is disposed near one end along its long side on the upper surface of the lower electrode 41. Each upper electrode 42 has an elongated shape and electrically connects the two MR elements 30 disposed adjacent to the two lower electrodes 41.

[0072] The number of curved surface portions 60a2 of the opposing surfaces 60a of the support member 60 can be one or more. When there is only one curved surface portion 60a2, multiple MR elements 30 are disposed on that single curved surface portion 60a2. In this case, the multiple MR elements 30 can be disposed on either the first inclined portion SL1 or the second inclined portion SL2, or on both the first inclined portion SL1 and the second inclined portion SL2.

[0073] When there are multiple curved surface portions 60a2, one MR element 30 or multiple MR elements 30 can be configured on each curved surface portion 60a2. In addition, in this case, the multiple curved surface portions 60a2 can be arranged in a manner that is arranged along one direction, or they can be arranged in multiple columns in the X and Y directions respectively.

[0074] Next, refer to Figure 6 and Figure 7 The tilted portion and MR element 30 will be described in more detail. Here, the first tilted portion SL1 will be used as an example. Figure 7 This is an explanatory diagram illustrating the shape of the first inclined portion SL1. Furthermore, in Figure 7 In this paper, the base layer 31 and capping layer 35 of the MR element 30 are omitted.

[0075] Figure 7A specific cross-section is shown that intersects the MR element 30 and is perpendicular to the lower surface 60b of the support member 60. Hereinafter, this cross-section will be designated by reference numeral S. Cross-section S intersects the long side direction of the MR element 30. To illustrate the shape of the first inclined portion SL1, first positions P1, second positions P2, third positions P3, and fourth positions P4 on the first inclined portion SL1 in any cross-section S are defined. First position P1 is the position where the first inclined portion SL1 is inclined relative to the lower surface 60b at a first angle θ1. Second position P2 is the position where the first inclined portion SL1 is inclined relative to the lower surface 60b at a second angle θ2 smaller than the first angle θ1. In this embodiment, specifically, first position P1 is closer to the lower surface 60b than second position P2. Furthermore, in the following description, the angle formed by a specific surface relative to the lower surface 60b is expressed as an angle of 0° to 90°.

[0076] Position P3 is the position closest to the lower surface 60b in the first inclined portion SL1. Specifically, position P3 is the end of the first inclined portion SL1 in the -Y direction, located at the boundary between the curved portion 60a2 and the planar portion 60a1. Position P4 is the position furthest from the lower surface 60b in the first inclined portion SL1. Specifically, position P4 is the end of the first inclined portion SL1 in the Y direction, located at the boundary between the first inclined portion SL1 and the second inclined portion SL2, i.e., the center of the curved portion 60a2. Positions P1 and P2 are within the range from position P3 to position P4.

[0077] The angles formed by the first inclined portion SL1 relative to the lower surface 60b at position 3 P3 and position 4 P4 are both 0°. The first angle θ1 and the second angle θ2 are both greater than 0° and less than 90°. In this embodiment, specifically, the first inclined portion SL1 is inclined relative to the lower surface 60b in such a manner that the first angle θ1 is at its maximum and the second angle θ2 is at its minimum within the range from position 1 P1 to position 2 P2.

[0078] The profile of the first inclined portion SL1 in any cross section S is composed of multiple curves with different curvatures. The absolute value of the curvature k1 of the first inclined portion SL1 at the first position P1 is less than the absolute value of the curvature k2 of the first inclined portion SL1 at the second position P2. In other words, the first inclined portion SL1 at the first position P1 is closer to a straight line than the first inclined portion SL1 at the second position P2, and is a gentle curve.

[0079] exist Figure 7In the diagram, the arc marked C1 represents a portion of the circle approximating the first inclined portion SL1 at position P1, i.e., the first circle of curvature. Similarly, the arc marked C2 represents a portion of the circle approximating the first inclined portion SL1 at position P2, i.e., the second circle of curvature. For example... Figure 7 As shown, the radius of the first curvature circle (symbol C1) is greater than the radius of the second curvature circle (symbol C2).

[0080] Within the range from position 1 P1 to position 2 P2, the absolute value of the curvature of the first inclined portion SL1 is maximized at a predetermined position on the first inclined portion SL1 other than position 1 P1. This predetermined position can be position 2 P2, or any position other than positions 1, 2, P1, and P2. Furthermore, the absolute value of the curvature of the first inclined portion SL1, from position 1 P1 to position 2 P2, can either increase monotonically or repeatedly increase and decrease but increase overall.

[0081] In addition, Figure 7 In the example shown, the profile of the first inclined portion SL1 in any cross-section S is a smooth curve from position P1 to position P2. However, the profile of the first inclined portion SL1 may also include points where the curvature becomes substantially infinite. In this case, the profile of the first inclined portion SL1 bends at the points where the curvature becomes substantially infinite. Furthermore, at the bend point, the angle θb of the first inclined portion SL1 relative to the lower surface 60b is defined as follows. For points on the first inclined portion SL1 near the bend point and further from the bend point than the bend point on the lower surface 60b, the angle of the first inclined portion SL1 relative to the lower surface 60b is denoted as θa. For points on the first inclined portion SL1 near the bend point and further from the bend point than the bend point on the lower surface 60b, the angle of the first inclined portion SL1 relative to the lower surface 60b is denoted as θc. Angle θb is an angle less than angle θa and greater than angle θc. Angle θb can also be the average of angles θa and θc.

[0082] The MR element 30 is disposed on the first inclined portion SL1 such that its first end 30c is located above the first position P1 in any cross-section S. In this embodiment, the MR element 30 is further disposed on the first inclined portion SL1 such that its second end 30d is located above the second position P2 in any cross-section S. Therefore, in this embodiment, the MR element 30 is disposed on the region of the first inclined portion SL1 from the first position P1 to the second position P2.

[0083] In addition, such as Figure 6 and Figure 7As shown, the free layer 34 of the MR element 30 has: a first surface 34a, a second surface 34b opposite to the first surface 34a, and an outer peripheral surface connecting the first surface 34a and the second surface 34b. The first surface 34a is located further away from the opposite surface 60a of the support member 60 than the second surface 34b. The first surface 34a is in contact with the capping layer 35. The second surface 34b is in contact with the gap layer 33.

[0084] In this embodiment, the MR element 30 is patterned into a shape that is elongated in the X direction. Therefore, the first surface 34a and the second surface 34b each have a shape that is elongated in the X direction. The first surface 34a has a first end point Ed1 and a second end point Ed2 located at both ends in the short side direction of the first surface 34a. The first end point Ed1 is located at the first end point 30c of the MR element 30. The second end point Ed2 is located at the second end point 30d of the MR element 30.

[0085] Here, the angle formed by the first surface 34a relative to the lower surface 60b of the supporting member 60 is called the tilt angle, denoted by the symbol . Indicated. Face 1, 34a, at an inclined angle. The angle is greater than 0°, and it is inclined relative to the lower surface 60b of the support member 60.

[0086] Here, the tilt angle of the first end Ed1 is... denoted as tilt angle The tilt angle of the second end Ed2 denoted as tilt angle In any cross section S, the inclination angle of the first end Ed1 greater than the tilt angle of the second end Ed2 In any cross section S, it can also be the tilt angle. It increases as it moves from the second end Ed2 closer to the first end Ed1.

[0087] Inclination angle at any position on face 34a It varies depending on the angle θ formed by the first inclined portion SL1 relative to the lower surface 60b. Specifically, the inclination angle at any position on the first surface 34a... The angle θ between this position and the position on the first inclined portion SL1 below this arbitrary position is approximately equal. Therefore, the tilt angle... It increases as the angle θ increases.

[0088] The free layer 34 has a film thickness T as a dimension in the direction perpendicular to the first surface 34a. Film thickness T is also the interval between the first surface 34a and the second surface 34b in the direction perpendicular to the first surface 34a. Here, the film thickness T of the first end Ed1 is denoted as film thickness T1, and the film thickness T of the second end Ed2 is denoted as film thickness T2. Film thickness T1 is also the film thickness T of the first end 30c of the MR element 30. Film thickness T2 is also the film thickness T of the second end 30d of the MR element 30. Furthermore, regarding film thickness T2, for ease of explanation, it is assumed that the second surface 34b is a virtual surface extending along the curved portion 60a2, and the interval between the first surface 34a and the virtual surface in the direction perpendicular to the first surface 34a is defined as film thickness T2.

[0089] In any cross section S, the film thickness T1 at the first end Ed1 is less than the film thickness T2 at the second end Ed2. Alternatively, in any cross section S, the film thickness T may decrease as it moves closer to the first end Ed1 from the second end Ed2.

[0090] The film thickness T at any location on the first surface 34a varies depending on the angle θ. Specifically, the film thickness T at any location on the first surface 34a decreases as the angle θ of the location on the first inclined portion SL1 closest to that arbitrary location increases.

[0091] Additionally, based on the tilt angle The relationship between the film thickness T and the angle θ, and the relationship between the film thickness T and the angle θ, the film thickness T with the tilt angle It gets bigger and smaller.

[0092] Up to this point, the description has taken the first inclined portion SL1 as an example. The first inclined portion SL1 and the second inclined portion SL2 have shapes that are symmetrical or substantially symmetrical about the XZ plane containing the central curved surface portion 60a2. Therefore, the description of the first inclined portion SL1 also applies to the second inclined portion SL2. Furthermore, the description of the MR element 30 also applies to the MR element 30 disposed on the second inclined portion SL2.

[0093] Next, refer to Figures 8 to 12 The manufacturing method of the magnetic sensor 1 according to this embodiment will be described. The manufacturing method of the magnetic sensor 1 includes: forming a magnetic sensor 1... Figures 3 to 5 The part shown is the process of the detection unit and the process of using the detection unit to complete the magnetic sensor 1. Figures 8 to 12 The process for forming the inspection section is shown. Furthermore, Figures 8 to 12 Focusing on the MR element 30 formed on the first inclined portion SL1.

[0094] like Figure 8As shown, in the process of forming the detection unit, firstly, an insulating layer 62 is formed on the substrate 61. The insulating layer 62 can be formed by forming an insulating film after forming a photoresist mask on the substrate 61, or it can be formed by etching a portion of the insulating film after forming an insulating film on the substrate 61. The support member 60 is completed by forming the insulating layer 62.

[0095] Figure 9 The following steps are shown. In this step, a lower electrode 41 and an insulating layer 63 are formed on the insulating layer 62, i.e., on the support member 60. The lower electrode 41 and the insulating layer 63 are formed, for example, as follows: First, a metal film is formed on the insulating layer 62. Next, an etching mask is formed on the metal film. The etching mask can also be formed by patterning a photoresist layer using photolithography. Next, the metal film is etched using the etching mask, with the metal film serving as the lower electrode 41. Next, the remaining etching mask is retained, and the insulating layer 63 is formed. Next, the etching mask is removed.

[0096] Figure 10 The following steps are shown. In this step, the layers that will later constitute the MR element 30 are formed sequentially, and a multilayer film 30P that will become the MR element 30 is formed on the lower electrode 41 and the insulating layer 63. Next, an etching mask 81 is formed on the multilayer film 30P. The etching mask 81 is formed by patterning a photoresist layer using photolithography. The etching mask 81 has a planar shape corresponding to the planar shape (shape viewed from above) of the MR element 30. The etching mask 81 has a first wall surface 81a that defines the position of the first end 30c of the MR element 30, and a second wall surface 81b that defines the position of the second end 30d of the MR element 30.

[0097] Figure 11 The next step is shown. In this step, the laminate 30P is etched using an etching mask 81, for example by ion milling or reactive ion etching. Thus, the laminate 30P becomes the MR element 30.

[0098] Figure 12 The following steps are shown. In this step, firstly, the residual etch mask 81 is retained, and an insulating layer 64 is formed. Next, the etch mask 81 is removed. Then, an upper electrode 42 and an insulating layer 65 are formed on the MR element 30 and the insulating layer 64. The method for forming the upper electrode 42 and the insulating layer 65 is the same as the method for forming the lower electrode 41 and the insulating layer 63.

[0099] Next, an insulating layer (not shown) is formed to cover the upper electrode 42 and the insulating layer 65. Then, the formation of multiple terminals constituting power supply terminals V1, V2, etc., is performed to complete the detection section of the magnetic sensor 1.

[0100] Next, refer to Figure 13 An example of the shape and curvature of the opposite surface 60a of the support member 60 will be described. Figure 13 It is a characteristic diagram showing the shape and curvature of the opposite face 60a of the support member 60 in the specified cross section S. Figure 13 This was obtained by measuring the opposing surfaces 60a of the actually manufactured support member 60 using an atomic force microscope. Figure 13 In the diagram, the horizontal axis represents the position in the direction parallel to the Y direction. The vertical axis on the left represents the curvature of the opposite surface 60a. Furthermore, Figure 13 The curvature shown is defined as a positive value when the opposing surface 60a is a convex surface protruding in the direction separating from the lower surface 60b. The vertical axis on the right represents the height of the opposing surface 60a. Furthermore, in Figure 13 In this context, the position in the direction parallel to the Z direction is set as the height of the opposite surface 60a. Furthermore, in... Figure 13 In this diagram, the height of the planar portion 60a1 of the opposing surface 60a is set to 0. Furthermore, the solid line marked with reference numeral 71 represents the curvature of the opposing surface 60a. The thick solid line marked with reference numeral 72 represents the height of the opposing surface 60a.

[0101] exist Figure 13 In the diagram, the points marked P1L and P2L represent the positions corresponding to the first end 30c and the second end 30d of the MR element 30 disposed on the first inclined portion SL1, respectively. The MR element 30 is disposed on the region in the first inclined portion SL1 from point P1L to point P2L. Points P1L and P2L essentially represent the first position P1 and the second position P2 on the first inclined portion SL1. Figure 13 As shown, the angle between the opposite surface 60a and the lower surface 60b at point P1L is greater than the angle between the opposite surface 60a and the lower surface 60b at point P2L. The absolute value of the curvature of the opposite surface 60a at point P1L is less than the absolute value of the curvature of the opposite surface 60a at point P2L. Within the range from point P1L to point P2L, the absolute value of the curvature of the opposite surface 60a is minimum at point P1L and maximum at specified locations other than point P1L.

[0102] Similarly, in Figure 13 In the diagram, the points marked P1R and P2R represent the positions corresponding to the first end 30c and the second end 30d of the MR element 30 disposed on the second inclined portion SL2, respectively. The MR element 30 is disposed on the region in the second inclined portion SL2 from point P1R to point P2R. Points P1R and P2R essentially represent the first position P1 and the second position P2 on the second inclined portion SL2. Figure 13As shown, the angle between the opposing surface 60a and the lower surface 60b at point P1R is greater than the angle between the opposing surface 60a and the lower surface 60b at point P2R. The absolute value of the curvature of the opposing surface 60a at point P1R is less than the absolute value of the curvature of the opposing surface 60a at point P2R. Within the range from point P1R to point P2R, the absolute value of the curvature of the opposing surface 60a is minimum at point P1R and maximum at specified locations other than point P1R.

[0103] Next, the function and effects of the magnetic sensor 1 in this embodiment will be explained. For example... Figure 7 As shown, in this embodiment, in any cross-section S, the first inclined portion SL1 is inclined at a first position P1 relative to the lower surface 60b at a first angle θ1, and at a second position P2 relative to the lower surface 60b at a second angle θ2 smaller than the first angle θ1. The absolute value of the curvature k1 of the first inclined portion SL1 at the first position P1 is less than the absolute value of the curvature k2 of the first inclined portion SL1 at the second position P2.

[0104] The MR element 30, disposed on the first inclined portion SL1, is positioned such that its first end 30c is located above the first position P1 in any cross-section S. In this embodiment, the MR element 30 is further disposed on the first inclined portion SL1 such that its second end 30d is located above the second position P2 in any cross-section S.

[0105] For reference Figures 8 to 12 As explained, the MR element 30 is formed by etching the laminated film 30P. In this etching, an etching mask 81 is used. The etching mask 81 is formed on the laminated film 30P at the desired location by patterning the photoresist layer using photolithography.

[0106] The etching mask 81 has a first wall surface 81a that defines the position of the first end 30c of the MR element 30, and a second wall surface 81b that defines the position of the second end 30d of the MR element 30. In design, the first wall surface 81a is located above a predetermined first position P1, and the second wall surface 81b is located above a predetermined second position P2. However, in actual manufacturing processes, due to the precision of photolithography, the position and dimensions of the etching mask 81 may deviate. As a result, the positions of the first wall surface 81a and the second wall surface 81b change, and the positions of the first end 30c and the second end 30d of the MR element 30 deviate from their designed positions.

[0107] Here, the deviation of the angle formed by the first inclined portion SL1 at a predetermined position P relative to the lower surface 60b will be explained. Here, the symbol θ represents the angle formed by the first inclined portion SL1 at the predetermined position P relative to the lower surface 60b, and the symbol k represents the curvature of the first inclined portion SL1 at the predetermined position P. Furthermore, the symbol Δθ represents the deviation of the angle formed by the first inclined portion SL1 relative to the lower surface 60b when the predetermined position P deviates by an amount Δy in a direction parallel to the Y direction. When Δy is sufficiently small, the deviation Δθ can be expressed by the following equation (1). Furthermore, the curvature k is assumed to remain unchanged.

[0108] Δθ=k*Δy / cosθ …(1)

[0109] According to equation (1), the larger the curvature k, the larger the deviation Δθ becomes. Furthermore, the larger the angle θ, the larger the deviation Δθ becomes.

[0110] As mentioned above, the film thickness T of the free layer 34 of the MR element 30 varies depending on the angle θ. Therefore, according to equation (1), it can be said that the greater the curvature k, the greater the change in film thickness T, and the greater the angle θ, the greater the change in film thickness T.

[0111] In this embodiment, the first angle θ1 is greater than the second angle θ2. Therefore, if the profile of the first inclined portion SL1 is assumed to have a constant curvature k, such as an arc, and the same Δy, then the deviation Δθ near the first position P1 is greater than the deviation Δθ near the second position P2. As a result, the change in film thickness T at the first end 30c is greater than the change in film thickness T at the second end 30d.

[0112] In contrast, in this embodiment, the absolute value of the curvature k1 of the first inclined portion SL1 at the first position P1 is made smaller than the absolute value of the curvature k2 of the first inclined portion SL1 at the second position P2. That is, in this embodiment, the curvature k of the first inclined portion SL1 is made relatively smaller at positions where the change in the film thickness T of the free layer 34 is relatively large. Therefore, according to this embodiment, compared to the case where the curvature k of the first inclined portion SL1 is constant, or the case where the absolute value of curvature k1 is greater than the absolute value of curvature k2, the change in the film thickness T of the free layer 34 near the first end 30c due to manufacturing process deviations can be suppressed.

[0113] Furthermore, according to this embodiment, for layers other than the free layer 34 constituting the MR element 30, changes in film thickness near the first end 30c due to manufacturing process deviations can also be suppressed. As a result, according to this embodiment, changes in the thickness (dimension in the direction perpendicular to the first inclined portion SL1) of the MR element 30 near the first end 30c due to manufacturing process deviations can be suppressed.

[0114] Furthermore, in this embodiment, the MR element 30 is positioned above a second position P2 where the change in the film thickness T of the free layer 34 is relatively small at the second end 30d. Therefore, according to this embodiment, changes in the film thickness T of the free layer 34 near the second end 30d and the thickness of the MR element 30 near the second end 30d due to manufacturing process variations can be suppressed. As a result, according to this embodiment, changes in the overall film thickness T of the free layer 34 and the overall thickness of the MR element 30 can be suppressed.

[0115] Next, other effects of this embodiment will be explained. In this embodiment, the film thickness T of the free layer 34 at any position on the first surface 34a decreases as the angle θ of the position on the first inclined portion SL1 closest to that arbitrary position increases. This relationship between film thickness T and angle θ can be achieved by forming a stacked film 30P using a so-called informal film deposition apparatus such as a magnetron sputtering apparatus.

[0116] In this embodiment, in particular, in any cross-section S, the film thickness T1 of the first end Ed1 is less than the film thickness T2 of the second end Ed2. Therefore, according to this embodiment, it is possible to suppress the concentration of magnetic charge towards the first end Ed1 and its vicinity in the free layer 34.

[0117] The following section will explain in detail the effect of suppressing magnetic charge concentration while comparing it with the comparative example MR element 230. First, referring to... Figure 14 The MR element 230 of the comparative example will be described. Figure 14 This is an explanatory diagram illustrating the magnetic charge of the MR element 230 in the comparative example. Figure 14 The cross section corresponding to section S is shown. The comparative example MR element 230, like the MR element 30 in this embodiment, includes: a magnetized fixing layer 232, a gap layer 233 and a free layer 234, a base layer and a capping layer (not shown).

[0118] In the comparative example, the MR element 230 is disposed on a plane parallel to the lower surface 60b of the support member 60. Furthermore, the MR element 230, like the MR element 30 in this embodiment, is patterned in a shape that is elongated in the X direction. Thus, the free layer 234 has shape magnetic anisotropy with its easy magnetization axis direction parallel to the X direction.

[0119] The free layer 234 has: a first surface 234a located at one end in the Z direction, a second surface 234b on the opposite side of the first surface 234a, and an outer peripheral surface connecting the first surface 234a and the second surface 234b. Both the first surface 234a and the second surface 234b are planes parallel to the lower surface 60b. Both the first surface 234a and the second surface 234b have a shape that is elongated in the X direction. The first surface 234a has a first end Ed11 and a second end Ed12 located at both ends in the short side direction of the first surface 234a, i.e., in the direction parallel to the Y direction. In a comparative example, specifically, the first end Ed11 is the end located at the -Y direction end of the first surface 234a, and the second end Ed12 is the end located at the Y direction end of the first surface 234a.

[0120] When an external magnetic field is applied to the MR element 230, the direction of the magnetic moment inside the free layer 234 rotates according to the direction and strength of the external magnetic field, resulting in a rotation of the magnetization direction of the free layer 234. Furthermore, in this case, magnetic charges are generated on the outer peripheral surface of the free layer 234.

[0121] Here, we consider the case where an external magnetic field in the Y direction is applied to the MR element 230. When an external magnetic field in the Y direction is applied, positive magnetic charges concentrate near the second end Ed12 on the outer peripheral surface of the free layer 234, while negative magnetic charges concentrate near the first end Ed11 on the outer peripheral surface of the free layer 234. Figure 14 In the diagram, the "+" sign represents a positive magnetic charge, and the "-" sign represents a negative magnetic charge. These magnetic charges generate a counter-magnetic field in the -Y direction within the free layer 234. The closer to the magnetic charge, the stronger the counter-magnetic field. Therefore, the counter-magnetic field is stronger near the first end Ed11 and the second end Ed12 of the free layer 234, and weaker in the central part of the free layer 234.

[0122] Without an applied external magnetic field, the magnetization direction of the free layer 234 and the direction of the magnetic moment inside the free layer 234 are parallel to the X direction. When the strength of the external magnetic field is small, the direction of the magnetic moment begins to rotate towards the Y direction in the central part of the free layer 234. However, in the vicinity of the first end Ed11 and the second end Ed12 of the free layer 234, the direction of the magnetic moment does not rotate or hardly rotates.

[0123] When the strength of the external magnetic field increases to a certain level, in the central portion of the free layer 234, the direction of the magnetic moment is aligned with or nearly aligned with the Y direction. On the other hand, in the vicinity of the first end Ed11 and the second end Ed12 of the free layer 234, the direction of the magnetic moment begins to rotate towards the Y direction. When the strength of the external magnetic field increases further, in the vicinity of the first end Ed11 and the second end Ed12 of the free layer 234, the direction of the magnetic moment is also aligned with or nearly aligned with the Y direction.

[0124] Thus, in the comparative example MR element 230, the direction of the overall magnetic moment of the free layer 234 does not change in the same way due to the opposing magnetic field. As a result, the magnetization of the free layer 234 changes non-linearly with respect to the change in the strength of the external magnetic field. Consequently, the detection signal generated by the magnetic sensor equipped with the comparative example MR element 230 changes non-linearly with respect to the change in the strength of the external magnetic field.

[0125] Next, the magnetic charge of the MR element 30 in this embodiment will be described. Figure 15 This is an explanatory diagram used to illustrate the magnetic charge in MR element 30. Figure 15 The cross section corresponding to section S is shown. In Figure 15 In Chinese, the "+" symbol represents a positive magnetic charge, and the "-" symbol represents a negative magnetic charge.

[0126] In the MR element 30 of this embodiment, the film thickness T1 of the first end Ed1 is smaller than the film thickness T2 of the second end Ed2. Here, we consider the case where an external magnetic field in the Y direction is applied to the MR element 30. In this case, similar to the comparative example, positive magnetic charges are concentrated in the portion near the second end Ed2 on the outer peripheral surface of the free layer 34. On the other hand, negative magnetic charges are not concentrated in the portion near the first end Ed1 on the outer peripheral surface of the free layer 34, but extend to the first surface 34a. As a result, the difference between the strength of the countermagnetic field near the first end Ed1 of the free layer 34 and the strength of the countermagnetic field in the central portion of the free layer 34 becomes smaller. As this difference decreases, the direction of the magnetic moment in the portion near the first end Ed1 of the free layer 34 rotates in the same manner as the magnetic moment in the central portion of the free layer 34. Therefore, according to this embodiment, it is possible to suppress the nonlinear change in magnetization of the free layer 34 relative to the strength of the external magnetic field. As a result, according to this embodiment, it is possible to expand the range in which the detection signal generated by the magnetic sensor 1 changes linearly.

[0127] However, in order to suppress the thickness deviation of the MR element 30 caused by manufacturing process variations, it is considered to reduce the curvature k of the first inclined portion SL1 as a whole. However, if this is done, the difference between the first angle θ1 and the second angle θ2 becomes smaller, and the difference between the film thickness T1 of the first end Ed1 and the film thickness T2 of the second end Ed2 also becomes smaller. In particular, when the curvature k of the first inclined portion SL1 is made to be 0, that is, when the first inclined portion SL1 is made to be planar as a whole, the first angle θ1 and the second angle θ2 become the same, and the film thickness T1 of the first end Ed1 and the film thickness T2 of the second end Ed2 become the same. As a result, the effect of suppressing the concentration of magnetic charge towards the first end Ed1 and its vicinity cannot be obtained.

[0128] In contrast, in this embodiment, the absolute value of the curvature k2 of the first inclined portion SL1 at the second position P2, where the angle θ is relatively smaller, is relatively larger. Therefore, according to this embodiment, the difference between the first angle θ1 and the second angle θ2 is increased, and the difference between the film thickness T1 of the first end Ed1 and the film thickness T2 of the second end Ed2 is also increased. Thus, according to this embodiment, changes in the film thickness T1 of the first end Ed1 due to manufacturing process deviations can be suppressed, and the concentration of magnetic charge towards the first end Ed1 and its vicinity in the free layer 34 can be suppressed.

[0129] Furthermore, up to this point, the effects of this embodiment have been explained using the MR element 30 disposed on the first inclined portion SL1 as an example. However, since the first inclined portion SL1 and the second inclined portion SL2 have symmetrical shapes, the above explanation can also be applied to the MR element 30 disposed on the second inclined portion SL2.

[0130] [Variation Example]

[0131] Next, refer to Figure 16 A variation of this embodiment will now be described. In this variation, the MR element 30 is an AMR (anisotropic magnetoresistive) element. In this variation, the MR element 30 includes a magnetic layer 36 configured to be magnetically anisotropic, instead of... Figure 6 The magnetized fixed layer 32, gap layer 33, and free layer 34 are shown. The magnetic layer 36 has a magnetization whose direction can change according to the direction of the external magnetic field. As previously described, the MR element 30 is patterned into a shape that is elongated in the X direction. Thus, the magnetic layer 36 has a magnetic anisotropy with its easy magnetization axis parallel to the X direction.

[0132] The magnetic layer 36 has: a first surface 36a that is elongated in the X direction, a second surface 36b opposite to the first surface 36a, and an outer peripheral surface connecting the first surface 36a and the second surface 36b. (See reference...) Figure 6 and Figure 7The description of the shape of the MR element 30 also applies to the modified examples. If the free layer 34, the first surface 34a, and the second surface 34b in the description of the shape of the MR element 30 are replaced with the magnetic layer 36, the first surface 36a, and the second surface 36b, respectively, then it becomes a description of the shape of the modified examples.

[0133] [Second Implementation]

[0134] Next, the second embodiment of the present invention will be described. First, referring to... Figure 17 The structure of the magnetic sensor in this embodiment will be described. Figure 17 This is a cross-sectional view showing a portion of the magnetic sensor according to this embodiment.

[0135] The structure of the magnetic sensor 101 in this embodiment differs from that of the magnetic sensor 1 in the first embodiment in the following aspects. The magnetic sensor 101 in this embodiment has an MR element 130 instead of the MR element 30 in the first embodiment. Figure 17 The cross section is shown, which is parallel to the YZ plane and intersects with MR element 130.

[0136] The opposing surface 60a of the support member 60, instead of the curved surface portion 60a2 in the first embodiment, includes at least one curved surface portion 60a3 that is not parallel to the lower surface 60b. For example... Figure 17 As shown, the curved surface portion 60a3 is a concave surface that is recessed towards the lower surface 60b. As described later, the opposing surface 60a includes an inclined portion that is part of the aforementioned concave surface (curved surface portion 60a3). In any cross-section parallel to the YZ plane, the curved surface portion 60a3 has a curved shape (arch shape) that bends in a direction towards the lower surface 60b (-Z direction). In any cross-section parallel to the YZ plane, the distance from the lower surface 60b to the curved surface portion 60a3 is minimized at the center of the curved surface portion 60a3 in a direction parallel to the Y direction (hereinafter simply referred to as the center of the curved surface portion 60a3).

[0137] The curved portion 60a3 extends along the X direction. The overall shape of the curved portion 60a3 is... Figure 17 The curved shape shown is a semi-cylindrical surface formed by moving along the X direction. Furthermore, the insulating layer 62 of the supporting member 60 has a cross-sectional shape such that a curved portion 60a3 is formed on the opposing surface 60a. Specifically, the insulating layer 62 has a cross-sectional shape that is concave in the -Z direction in any cross-section parallel to the YZ plane.

[0138] Here, the portion of the curved surface 60a3 from its end in the Y direction to its center is referred to as the first inclined portion, denoted by reference numeral SL11. The portion of the curved surface 60a3 from its end in the -Y direction to its center is referred to as the second inclined portion, denoted by reference numeral SL12. Both the first inclined portion SL11 and the second inclined portion SL12 are inclined relative to the lower surface 60b. In this embodiment, the MR element 130 is entirely disposed on either the first inclined portion SL11 or the second inclined portion SL12. Figure 17 The image shows an MR element 130 disposed on the first inclined portion SL11.

[0139] MR element 130 has a shape that is elongated in the X direction. The planar shape of MR element 130 is rectangular. Here, the direction of the shorter side of MR element 130 is referred to as the width direction of MR element 130, or simply the width direction. MR element 130 has: a lower surface 130a opposite to the curved surface portion 60a3, an upper surface 130b located on the opposite side of the lower surface 130a, a first end 130c and a second end 130d located at both ends in the width direction, and a third end and a fourth end located at both ends in the longer side direction. The dimension of the width direction of MR element 130 is constant or approximately constant regardless of its position in the X direction.

[0140] The MR element 130 can be a spin valve type MR element or an AMR element. Hereinafter, the case where the MR element 130 is a spin valve type MR element will be described as an example. The MR element 130, as in the first embodiment... Figure 6 The MR element 30 shown also has: a base layer 31, a magnetization fixation layer 32, a gap layer 33, a free layer 34, and a capping layer 35. The free layer 34 has a shape magnetic anisotropy with its easy magnetization axis parallel to the X-direction.

[0141] Next, refer to Figure 18 The tilted portion and MR element 130 will be described in detail. Here, the first tilted portion SL11 will be used as an example. Figure 18 This is an explanatory diagram used to illustrate the shape of the first inclined portion SL11. Figure 18 It is Figure 17 An enlarged view of a portion of the cross-section shown. Additionally, in Figure 18 In this paper, the base layer 31 and capping layer 35 of the MR element 130 are omitted.

[0142] Hereinafter, the cross-section intersecting the MR element 130 and perpendicular to the lower surface 60b of the support member 60 will be designated by reference numeral S. To illustrate the shape of the first inclined portion SL11, first positions P11, second positions P12, third positions P13, and fourth positions P14 on the first inclined portion SL11 in any cross-section S are defined. The first position P11 is the position where the first inclined portion SL11 is inclined relative to the lower surface 60b at a first angle θ11. The second position P12 is the position where the first inclined portion SL11 is inclined relative to the lower surface 60b at a second angle θ12 smaller than the first angle θ11. In this embodiment, specifically, the first position P11 is further away from the lower surface 60b than the second position P12.

[0143] Position 3, P13, is the position closest to the lower surface 60b in the first inclined portion SL11. Specifically, position 3, P13, is located at the center of the curved surface portion 60a3, which is the boundary between the first inclined portion SL11 and the second inclined portion SL12. Position 4, P14, is the position furthest from the lower surface 60b in the first inclined portion SL11. Specifically, position 4, P14, is located at the boundary between the curved surface portion 60a3 and the planar portion 60a1. Positions 1, P11, and 2, P12 fall within the range from position 3, P13, to position 4, P14.

[0144] The angles formed by the first inclined portion SL11 at position 3 P3 and the lower surface 60b, and the angles formed by the first inclined portion SL11 at position 4 P14 and the lower surface 60b, are both 0°. The first angle θ1 and the second angle θ2 are both greater than 0° and less than 90°.

[0145] The profile of the first inclined portion SL11 in any cross section S contains multiple curves with different curvatures. The absolute value of the curvature k11 of the first inclined portion SL11 at the first position P11 is less than the absolute value of the curvature k12 of the first inclined portion SL11 at the second position P12.

[0146] exist Figure 18 In the diagram, the arc marked C11 represents a portion of the circle approximating the first inclined portion SL11 at the first position P11, i.e., the first circle of curvature. Similarly, the arc marked C12 represents a portion of the circle approximating the first inclined portion SL11 at the second position P12, i.e., the second circle of curvature. For example... Figure 18 As shown, the radius of the first curvature circle (symbol C11) is greater than the radius of the second curvature circle (symbol C12).

[0147] The MR element 130 is disposed on the first inclined portion SL11 such that its first end 130c is located above the first position P11 in any cross section S. In this embodiment, the MR element 130 is further disposed on the first inclined portion SL11 such that its second end 130d is located above the second position P12 in any cross section S.

[0148] As described in the first embodiment, the free layer 34 has a first surface 34a, a second surface 34b, and an outer peripheral surface. The first surface 34a has a first end point Ed1 and a second end point Ed2 located at both ends in the short side direction of the first surface 34a. The first end point Ed1 is located at the first end point 130c of the MR element 130. The second end point Ed2 is located at the second end point 130d of the MR element 130.

[0149] Inclination angle of the first end Ed1 in any cross section S Inclination angle with the second end Ed2 The relationship is the same as in the first embodiment. Furthermore, the relationship between the film thickness T1 at the first end Ed1 and the film thickness T2 at the second end Ed2 in any cross-section S is the same as in the first embodiment. Additionally, regarding the film thickness T1, for ease of explanation, it is assumed that the second surface 34b is a virtual surface extended along the curved surface portion 60a3, and the distance between the first surface 34a and the virtual surface in a direction perpendicular to the first surface 34a is defined as the film thickness T1.

[0150] Up to this point, the description has taken the first inclined portion SL11 as an example. The first inclined portion SL11 and the second inclined portion SL12 have shapes that are symmetrical or substantially symmetrical about the XZ plane containing the central curved surface portion 60a3. Therefore, the description of the first inclined portion SL11 described above also applies to the second inclined portion SL12. Furthermore, the description of the MR element 130 described above also applies to the MR element 130 disposed on the second inclined portion SL12.

[0151] The other structures, functions, and effects in this embodiment are the same as in the first embodiment.

[0152] Furthermore, the present invention is not limited to the embodiments described above, and various modifications are possible. For example, as long as the requirements of the claims are met, the number and arrangement of MR elements and the number and arrangement of curved surface portions are not limited to the examples shown in the embodiments, and are arbitrary.

[0153] Furthermore, the first surface 34a and the second surfaces 34a and 34b of the free layer 34 of the present invention are not limited to a direction parallel to the X direction, and may also have a shape that is long in a direction intersecting any cross section S.

[0154] Furthermore, the second end of the MR element of the present invention may also be disposed on the portion of the planar portion 60a1 or the curved portion that is parallel to the lower surface 60b.

[0155] Based on the above description, it is obvious that various methods and variations of the present invention can be implemented. Therefore, within the same scope of the claims, the present invention can also be implemented in ways other than the preferred method described above.

Claims

1. A magnetic sensor, characterized in that: It comprises: a magnetoresistive element whose resistance changes according to an external magnetic field; and a support member supporting the magnetoresistive element. The support member has: a facing surface opposite to the magnetoresistive element; and a lower surface formed by planes disposed on opposite sides of the facing surface. The opposing surface includes an inclined portion that is tilted relative to the lower surface. As a cross-section of the magnetic sensor, in a specific cross-section perpendicular to the lower surface, the inclined portion is inclined at a first position relative to the lower surface at a first angle, and the inclined portion is inclined at a second position relative to the lower surface at a second angle smaller than the first angle. The absolute value of the curvature of the inclined portion at the first position is less than the absolute value of the curvature of the inclined portion at the second position. The magnetoresistive element has a first end and a second end located at both ends in the width direction of the magnetoresistive element, and is disposed on the inclined portion in such a way that the first end is above the first position in the cross section and the second end is above the second position in the cross section.

2. The magnetic sensor according to claim 1, characterized in that: The first position and the second position are located within a range from the third position on the inclined portion closest to the lower surface in the cross section to the fourth position on the inclined portion furthest from the lower surface in the cross section.

3. The magnetic sensor according to claim 2, characterized in that: The inclined portion, within the range from the first position to the second position, is inclined relative to the lower surface in such a manner that the first angle is the largest and the second angle is the smallest. The absolute value of the curvature of the inclined portion is minimum at the first position and maximum at a specified position other than the first position, within the range from the first position to the second position.

4. The magnetic sensor according to claim 1, characterized in that: The opposing surfaces include convex surfaces that project in a direction separating from the lower surface. The inclined portion is part of the convex surface.

5. The magnetic sensor according to claim 1, characterized in that: The opposing surface includes a concave surface that is recessed towards the lower surface. The inclined portion is part of the concave surface.

6. The magnetic sensor according to claim 1, characterized in that: The magnetoresistive element comprises a magnetized magnetic layer having an orientation that can change according to the external magnetic field. The magnetic layer has a first surface and a second surface disposed on the opposite side of the first surface, and has a film thickness that is a dimension in a direction perpendicular to the first surface of the magnetic layer. The film thickness at the first end is less than the film thickness at the second end.

7. The magnetic sensor according to claim 6, characterized in that: The film thickness decreases as it moves closer to the first end from the second end.

8. The magnetic sensor according to claim 6, characterized in that: The first surface and the second surface each have a shape that is elongated in the direction intersecting the cross section.

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