Magnetic sensor

Abstract

To provide a magnetic sensor which can prevent short-circuiting between electrodes.SOLUTION: A magnetic sensor 1 comprises: a substrate 301 including a top surface 301a; an insulating layer 305 disposed on the substrate 301, the insulating layer having first and second inclined surfaces 305a, 305b each inclined with respect to the top surface 301a of the substrate 301; and an MR element structure 70. The MR element structure 70 is disposed on the first inclined surface 305a or the second inclined surface 305b. The MR element structure 70 has: a bottom surface 70a facing the first inclined surface 305a or the second inclined surface 305b; a top surface 70b; and a first surface 70c connecting the bottom surface 70a to the top surface 70b, and including two steps.SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] The present invention relates to a magnetic sensor including a magnetoresistive element disposed on an inclined surface.

Background Art

[0002] In recent years, magnetic sensors using magnetoresistive elements have been used in various applications. In a system including a magnetic sensor, there are cases where it is desired to detect a magnetic field including a component in a direction perpendicular to the surface of a substrate by a magnetoresistive element provided on the substrate. In this case, by providing a soft magnetic material that converts a magnetic field in a direction perpendicular to the surface of the substrate into a magnetic field in a direction parallel to the surface of the substrate, or by disposing the magnetoresistive element on an inclined surface formed on the substrate, it is possible to detect a magnetic field including a component in a direction perpendicular to the surface of the substrate.

[0003] Patent Documents 1 and 2 disclose magnetic sensors including magnetoresistive elements formed on inclined surfaces. In the magnetic sensor disclosed in Patent Document 2, the side surface of the magnetoresistive element has a forward-tapered shape with respect to the inclined surface.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] Examples of magnetoresistive elements include TMR (tunnel magnetoresistance) elements and GMR (giant magnetoresistance) elements. In TMR elements, current flows in a direction approximately perpendicular to the plane of each layer constituting the TMR element. As for GMR elements, CPP (Current Perpendicular to Plane) type GMR elements are known, in which current flows in a direction approximately perpendicular to the plane of each layer constituting the GMR element. When TMR elements or CPP type GMR elements are used as magnetoresistive elements, multiple magnetoresistive elements are connected in series by multiple lower electrodes and multiple upper electrodes.

[0006] As described above, in TMR elements or CPP-type GMR elements, a magnetoresistive element is placed between the lower electrode and the upper electrode. Because the thickness of the magnetoresistive element is relatively small, the distance between the lower electrode and the upper electrode is also relatively small, and there is a risk of a short circuit between the lower electrode and the upper electrode. This problem becomes more pronounced when the magnetoresistive element is placed on an inclined surface.

[0007] The present invention has been made in view of the above problems, and its objective is to provide a magnetic sensor equipped with a magnetoresistive element arranged on an inclined surface that can prevent short circuits between electrodes. [Means for solving the problem]

[0008] The magnetic sensor of the present invention comprises a substrate having a reference plane, a support member disposed on the substrate and having an inclined surface tilted with respect to the reference plane, and a magnetic detection element structure disposed on the inclined surface and having a lower surface facing the inclined surface, an upper surface on the opposite side of the lower surface, and a first surface connecting the lower surface and the upper surface and including two steps. [Effects of the Invention]

[0009] In the magnetic sensor of the present invention, the magnetic detection element structure has a lower surface, an upper surface, and a first surface that connects the lower and upper surfaces and includes two steps. As a result, according to the present invention, in a magnetic sensor equipped with a magnetoresistive element placed on an inclined surface, it is possible to prevent the electrodes from short-circuiting. [Brief explanation of the drawing]

[0010] [Figure 1] This is a perspective view showing a magnetic sensor according to the first embodiment of the present invention. [Figure 2] This is a functional block diagram showing the configuration of a magnetic sensor device including a magnetic sensor according to the first embodiment of the present invention. [Figure 3] This is a circuit diagram showing the circuit configuration of the first detection circuit in the first embodiment of the present invention. [Figure 4] This is a circuit diagram showing the circuit configuration of the second detection circuit in the first embodiment of the present invention. [Figure 5] This is a plan view showing a part of a magnetic sensor according to the first embodiment of the present invention. [Figure 6] This is a cross-sectional view showing a part of a magnetic sensor according to the first embodiment of the present invention. [Figure 7] This is a side view showing a magnetoresistive element in the first embodiment of the present invention. [Figure 8] This is a cross-sectional view showing a first example MR element structure in the first embodiment of the present invention. [Figure 9] Figure 8 is a cross-sectional view showing the magnetoresistive element and lower electrode of the MR element structure. [Figure 10] This is a cross-sectional view showing a first example of the fourth side surface of the lower electrode in the first embodiment of the present invention. [Figure 11] This is a cross-sectional view showing a second example of the fourth side surface of the lower electrode in the first embodiment of the present invention. [Figure 12] This is a cross-sectional view showing an MR element structure of a second example in the first embodiment of the present invention. [Figure 13]It is a cross-sectional view showing a MR element structure in a first modification of a magnetic sensor according to a first embodiment of the present invention. [Figure 14] It is a cross-sectional view showing a magnetoresistive effect element and a lower electrode of the MR element structure shown in FIG. 13. [Figure 15] It is a cross-sectional view showing a MR element structure in a second modification of a magnetic sensor according to a first embodiment of the present invention. [Figure 16] It is a cross-sectional view showing a part of a magnetic sensor according to a second embodiment of the present invention.

Embodiments for Carrying Out the Invention

[0011] [First Embodiment] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. First, referring to FIGS. 1 and 2, the configuration of a magnetic sensor according to a first embodiment of the present invention will be described. FIG. 1 is a perspective view showing the magnetic sensor according to the present embodiment. FIG. 2 is a functional block diagram showing the configuration of a magnetic sensor device including the magnetic sensor according to the present embodiment.

[0012] As shown in FIG. 1, the magnetic sensor 1 has the form of a rectangular parallelepiped chip. The magnetic sensor 1 has an upper surface 1a and a lower surface located on opposite sides of each other, and four side surfaces connecting the upper surface 1a and the lower surface. Further, the magnetic sensor 1 has a plurality of electrode pads provided on the upper surface 1a.

[0013] Here, referring to FIG. 1, the reference coordinate system in the present embodiment will be described. The reference coordinate system is a coordinate system based on the magnetic sensor 1 and is an orthogonal coordinate system defined by three axes. In the reference coordinate system, the X direction, the Y direction, and the Z direction are defined. The X direction, the Y direction, and the Z direction are orthogonal to each other. In particular, in the present embodiment, the direction perpendicular to the upper surface 1a of the magnetic sensor 1 and the direction from the lower surface of the magnetic sensor 1 toward the upper surface 1a is defined as the Z direction. Also, the direction opposite to the X direction is defined as the -X direction, the direction opposite to the Y direction is defined as the -Y direction, and the direction opposite to the Z direction is defined as the -Z direction. The three axes defining the reference coordinate system are an axis parallel to the X direction, an axis parallel to the Y direction, and an axis parallel to the Z direction.

[0014] Hereinafter, a position ahead in the Z direction with respect to the reference position is referred to as "above", and a position on the opposite side of "above" with respect to the reference position is referred to as "below". Also, regarding the components of the magnetic sensor 1, the surface located at the end in the Z direction is referred to as the "upper surface", and the surface located at the end in the -Z direction is referred to as the "lower surface". Also, the expression "when viewed from the Z direction" means viewing the object from a position distant in the Z direction.

[0015] As shown in FIG. 2, the magnetic sensor 1 includes a first detection circuit 20 and a second detection circuit 30. Each of the first and second detection circuits 20, 30 includes a plurality of magnetic detection elements and is configured to detect a target magnetic field and generate at least one detection signal. In particular, in the present embodiment, the plurality of magnetic detection elements are a plurality of magnetoresistive effect elements. Hereinafter, the magnetoresistive effect element will be referred to as an MR element.

[0016] Multiple detection signals generated by the first and second detection circuits 20 and 30 are processed by the processor 40. The magnetic sensor 1 and the processor 40 constitute the magnetic sensor device 100. The processor 40 is configured to generate a first detection value and a second detection value that correspond to the components of the magnetic field at a predetermined reference position in two different directions by processing the multiple detection signals generated by the first and second detection circuits 20 and 30. In particular, in this embodiment, the two different directions are one direction parallel to the XY plane and one direction parallel to the Z direction. The processor 40 is configured, for example, by an application-specific integrated circuit (ASIC).

[0017] The processor 40 may be included, for example, in a support that supports the magnetic sensor 1. This support has a plurality of electrode pads. The first and second detection circuits 20, 30 and the processor 40 are connected, for example, via a plurality of electrode pads of the magnetic sensor 1, a plurality of electrode pads of the support, and a plurality of bonding wires. If the plurality of electrode pads of the magnetic sensor 1 are provided on the upper surface 1a of the magnetic sensor 1, the magnetic sensor 1 may be mounted on the upper surface of the support in a orientation where the lower surface of the magnetic sensor 1 faces the upper surface of the support.

[0018] Next, the first and second detection circuits 20 and 30 will be described with reference to Figures 3 to 6. Figure 3 is a circuit diagram showing the circuit configuration of the first detection circuit 20. Figure 4 is a circuit diagram showing the circuit configuration of the second detection circuit 30. Figure 5 is a plan view showing a part of the magnetic sensor 1. Figure 6 is a cross-sectional view showing a part of the magnetic sensor 1.

[0019] Here, as shown in Figure 5, the U and V directions are defined as follows: The U direction is the direction of rotation from the X direction toward the -Y direction. The V direction is the direction of rotation from the Y direction toward the X direction. In this embodiment, the U direction is specifically defined as the direction of rotation by α from the X direction toward the -Y direction, and the V direction is defined as the direction of rotation by α from the Y direction toward the X direction. Note that α is an angle greater than 0° and less than 90°. In one example, α is 45°. Furthermore, the direction opposite to the U direction is defined as the -U direction, and the direction opposite to the V direction is defined as the -V direction.

[0020] Furthermore, as shown in Figure 6, the W1 and W2 directions are defined as follows: The W1 direction is the direction of rotation from the V direction toward the -Z direction. The W2 direction is the direction of rotation from the V direction toward the Z direction. In this embodiment, the W1 direction is specifically defined as the direction of rotation by β from the V direction toward the -Z direction, and the W2 direction is defined as the direction of rotation by β from the V direction toward the Z direction. Note that β is an angle greater than 0° and less than 90°. The direction opposite to the W1 direction is defined as the -W1 direction, and the direction opposite to the W2 direction is defined as the -W2 direction. The W1 and W2 directions are orthogonal to the U direction, respectively.

[0021] The first detection circuit 20 is configured to detect a component of the target magnetic field parallel to the W1 direction and to generate at least one first detection signal corresponding to this component. The second detection circuit 30 is configured to detect a component of the target magnetic field parallel to the W2 direction and to generate at least one second detection signal corresponding to this component.

[0022] As shown in Figure 3, the first detection circuit 20 includes a power supply terminal V2, a ground terminal G2, signal output terminals E21 and E22, a first resistor R21, a second resistor R22, a third resistor R23, and a fourth resistor R24. The multiple MR elements of the first detection circuit 20 constitute the first to fourth resistors R21, R22, R23, and R24.

[0023] The first resistor R21 is located between the power supply terminal V2 and the signal output terminal E21. The second resistor R22 is located between the signal output terminal E21 and the ground terminal G2. The third resistor R23 is located between the signal output terminal E22 and the ground terminal G2. The fourth resistor R24 ​​is located between the power supply terminal V2 and the signal output terminal E22.

[0024] As shown in Figure 4, the second detection circuit 30 includes a power supply terminal V3, a ground terminal G3, signal output terminals E31 and E32, a first resistor R31, a second resistor R32, a third resistor R33, and a fourth resistor R34. The multiple MR elements of the second detection circuit 30 constitute the first to fourth resistors R31, R32, R33, and R34.

[0025] The first resistor R31 is located between the power supply terminal V3 and the signal output terminal E31. The second resistor R32 is located between the signal output terminal E31 and the ground terminal G3. The third resistor R33 is located between the signal output terminal E32 and the ground terminal G3. The fourth resistor R34 is located between the power supply terminal V3 and the signal output terminal E32.

[0026] A predetermined voltage or current is applied to each of the power supply terminals V2 and V3. Each of the ground terminals G2 and G3 is connected to ground.

[0027] Hereinafter, the multiple MR elements of the first detection circuit 20 will be referred to as multiple first MR elements 50B, and the multiple MR elements of the second detection circuit 30 will be referred to as multiple second MR elements 50C. Since the first and second detection circuits 20 and 30 are components of the magnetic sensor 1, it can also be said that the magnetic sensor 1 includes multiple first MR elements 50B and multiple second MR elements 50C. Furthermore, any MR element will be denoted by the reference numeral 50.

[0028] Figure 7 is a side view showing the MR element 50. The MR element 50 is a spin-valve type MR element that includes multiple magnetic layers. The MR element 50 has a magnetization fixed layer 51 having magnetization with a fixed direction, a free layer 53 having magnetization whose direction can change according to the direction of the target magnetic field, and a gap layer 52 disposed between the magnetization fixed layer 51 and the free layer 53. The MR element 50 may be a TMR (tunnel magnetoresistance) element or a GMR (giant magnetoresistance) element. In a TMR element, the gap layer 52 is a tunnel barrier layer. In a GMR element, the gap layer 52 is a non-magnetic conductive layer. In the MR element 50, the resistance value changes according to the angle that the direction of magnetization of the free layer 53 makes with respect to the direction of magnetization of the magnetization fixed layer 51. The resistance value is at its minimum when this angle is 0° and at its maximum when the angle is 180°. In each MR element 50, the free layer 53 has shape anisotropy such that its easy magnetization axis direction is perpendicular to the magnetization direction of the fixed magnetization layer 51. As a means of setting the easy magnetization axis of the free layer 53 in a predetermined direction, a magnet can be used to apply a bias magnetic field to the free layer 53. The fixed magnetization layer 51, gap layer 52, and free layer 53 are stacked in this order.

[0029] The MR element 50 may further have an antiferromagnetic layer located on the opposite side of the gap layer 52 in the magnetization fixed layer 51. The antiferromagnetic layer is made of an antiferromagnetic material and creates exchange coupling with the magnetization fixed layer 51 to fix the direction of magnetization of the magnetization fixed layer 51. Alternatively, the magnetization fixed layer 51 may be a so-called self-pinned fixed layer (Synthetic Ferri Pinned layer, SFP layer). The self-pinned fixed layer has a laminated ferri structure in which a ferromagnetic layer, a non-magnetic intermediate layer, and a ferromagnetic layer are stacked, and the two ferromagnetic layers are antiferromagnetically coupled.

[0030] Note that the arrangement of layers 51-53 in the MR element 50 may be reversed vertically from the arrangement shown in Figure 7.

[0031] In Figures 3 and 4, the filled-in arrows represent the direction of magnetization of the magnetization fixed layer 51 of the MR element 50. The open-circle arrows represent the direction of magnetization of the free layer 53 of the MR element 50 when no target magnetic field is applied to the MR element 50.

[0032] In the example shown in Figure 3, the magnetization direction of the magnetization fixed layer 51 in each of the first and third resistive sections R21 and R23 is in the W1 direction. The magnetization direction of the magnetization fixed layer 51 in each of the second and fourth resistive sections R22 and R24 is in the -W1 direction. Furthermore, each free layer 53 of the multiple first MR elements 50B has shape anisotropy such that the easy magnetization axis direction is parallel to the U direction. The magnetization direction of the free layer 53 in each of the first and second resistive sections R21 and R22 is in the U direction when no target magnetic field is applied to the first MR element 50B. In the above case, the magnetization direction of the free layer 53 in each of the third and fourth resistive sections R23 and R24 is in the -U direction.

[0033] In the example shown in Figure 4, the magnetization direction of the magnetization fixed layer 51 in each of the first and third resistive sections R31 and R33 is in the W2 direction. The magnetization direction of the magnetization fixed layer 51 in each of the second and fourth resistive sections R32 and R34 is in the -W2 direction. Furthermore, each free layer 53 of the multiple second MR elements 50C has shape anisotropy such that the easy magnetization axis direction is parallel to the U direction. The magnetization direction of the free layer 53 in each of the first and second resistive sections R31 and R32 is in the U direction when no target magnetic field is applied to the second MR element 50C. In the above case, the magnetization direction of the free layer 53 in each of the third and fourth resistive sections R33 and R34 is in the -U direction.

[0034] The magnetic sensor 1 includes a magnetic field generator configured to apply a magnetic field in a predetermined direction to the free layer 53 of each of the multiple first MR elements 50B and multiple second MR elements 50C. In this embodiment, the magnetic field generator includes a coil 80 that applies a magnetic field in a predetermined direction to the free layer 53 of each of the multiple first MR elements 50B and multiple second MR elements 50C.

[0035] Furthermore, the direction of magnetization of the fixed magnetization layer 51 and the direction of the easy magnetization axis of the free layer 53 may be slightly deviated from the above-mentioned direction from the viewpoint of the accuracy of fabrication of the MR element 50. Also, the magnetization of the fixed magnetization layer 51 may be configured to include a magnetization component whose main component is the direction described above. In this case, the direction of magnetization of the fixed magnetization layer 51 will be the direction described above or approximately the direction described above.

[0036] In this embodiment, the MR element 50 is configured such that current flows in the stacking direction of multiple magnetic layers, namely the magnetized fixed layer 51 and the free layer 53. As will be described later, the magnetic sensor 1 is equipped with a lower electrode and an upper electrode for supplying current to the MR element 50. The MR element 50 is positioned between the lower electrode and the upper electrode.

[0037] The specific structure of the magnetic sensor 1 will be described in detail below with reference to Figures 5 and 6. Figure 6 shows a portion of the cross-section at the position indicated by line 6-6 in Figure 5.

[0038] The magnetic sensor 1 includes a substrate 301 having an upper surface 301a, insulating layers 302, 303, 304, 305, 307, 308, 309, 310, a plurality of lower electrodes 61B, a plurality of lower electrodes 61C, a plurality of upper electrodes 62B, a plurality of upper electrodes 62C, a plurality of lower coil elements 81, and a plurality of upper coil elements 82. The upper surface 301a of the substrate 301 is assumed to be parallel to the XY plane. The Z direction is also a direction perpendicular to the upper surface 301a of the substrate 301. Note that a coil element is a part of the winding of a coil.

[0039] The insulating layer 302 is placed on the substrate 301. Multiple lower coil elements 81 are placed on the insulating layer 302. The insulating layer 303 is placed on the insulating layer 302 around the multiple lower coil elements 81. Insulating layers 304 and 305 are laminated in this order on the multiple lower coil elements 81 and insulating layer 303.

[0040] Multiple lower electrodes 61B and multiple lower electrodes 61C are arranged on an insulating layer 305. An insulating layer 307 is arranged on the insulating layer 305 around the multiple lower electrodes 61B and multiple lower electrodes 61C. Multiple first MR elements 50B are arranged on the multiple lower electrodes 61B. Multiple second MR elements 50C are arranged on the multiple lower electrodes 61C. An insulating layer 308 is arranged on the multiple lower electrodes 61B, multiple lower electrodes 61C and insulating layer 307 around the multiple first MR elements 50B and multiple second MR elements 50C. Multiple upper electrodes 62B are arranged on the multiple first MR elements 50B and insulating layer 308. Multiple upper electrodes 62C are arranged on the multiple second MR elements 50C and insulating layer 308. An insulating layer 309 is arranged on the insulating layer 308 around the multiple upper electrodes 62B and multiple upper electrodes 62C.

[0041] The insulating layer 310 is positioned on a plurality of upper electrodes 62B, a plurality of upper electrodes 62C, and an insulating layer 309. A plurality of upper coil elements 82 are positioned on the insulating layer 310. The magnetic sensor 1 may further include an insulating layer (not shown) covering the plurality of upper coil elements 82 and the insulating layer 310.

[0042] The magnetic sensor 1 includes a support member that supports a plurality of first MR elements 50B and a plurality of second MR elements 50C. The support member has at least one inclined surface that is inclined with respect to the upper surface 301a of the substrate 301. In this embodiment in particular, the support member is composed of an insulating layer 305. Figure 5 shows the insulating layer 305, the plurality of first MR elements 50B, the plurality of second MR elements 50C, and the plurality of upper coil elements 82 among the components of the magnetic sensor 1.

[0043] The insulating layer 305 has a plurality of convex surfaces 305c that protrude in the direction away from the upper surface 301a of the substrate 301 (Z direction). Each of the plurality of convex surfaces 305c extends in a direction parallel to the U direction. The overall shape of the convex surface 305c is a semi-cylindrical curved surface formed by moving the curved shape (arch shape) of the convex surface 305c shown in Figure 6 along a direction parallel to the U direction. Furthermore, the plurality of convex surfaces 305c are arranged at predetermined intervals in a direction parallel to the V direction.

[0044] Each of the multiple convex surfaces 305c has an upper end that is furthest from the upper surface 301a of the substrate 301. In this embodiment, the upper end of each of the multiple convex surfaces 305c is assumed to extend in a direction parallel to the U direction. Now, let us focus on any one of the multiple convex surfaces 305c. The convex surface 305c includes a first inclined surface 305a and a second inclined surface 305b. The first inclined surface 305a is the surface of the convex surface 305c that is on the V direction side of the upper end of the convex surface 305c. The second inclined surface 305b is the surface of the convex surface 305c that is on the -V direction side of the upper end of the convex surface 305c. In Figure 5, the boundary between the first inclined surface 305a and the second inclined surface 305b is shown by a dotted line.

[0045] The upper end of the convex surface 305c may be the boundary between the first inclined surface 305a and the second inclined surface 305b. In this case, the dotted line shown in Figure 5 indicates the upper end of the convex surface 305c.

[0046] The upper surface 301a of the substrate 301 is parallel to the XY plane. The first inclined surface 305a and the second inclined surface 305b are each inclined with respect to the upper surface 301a of the substrate 301, i.e., the XY plane. In a cross section perpendicular to the upper surface 301a of the substrate 301, the distance between the first inclined surface 305a and the second inclined surface 305b decreases as the distance from the upper surface 301a of the substrate 301 increases.

[0047] In this embodiment, since there are multiple convex surfaces 305c, there are also multiple first inclined surfaces 305a and multiple second inclined surfaces 305b. The insulating layer 305 has multiple first inclined surfaces 305a and multiple second inclined surfaces 305b.

[0048] The insulating layer 305 further has flat surfaces 305d surrounding the plurality of convex surfaces 305c. The flat surfaces 305d are parallel to the upper surface 301a of the substrate 301. Each of the plurality of convex surfaces 305c protrudes from the flat surfaces 305d in the Z direction. In this embodiment, the plurality of convex surfaces 305c are arranged with a predetermined interval between them. Therefore, a flat surface 305d exists between two adjacent convex surfaces 305c in the V direction.

[0049] The insulating layer 305 includes a plurality of protrusions projecting in the Z direction and flat portions surrounding the plurality of protrusions. Each of the plurality of protrusions extends in a direction parallel to the U direction and has a convex surface 305c. The plurality of protrusions are arranged at predetermined intervals in a direction parallel to the V direction. The thickness (dimension in the Z direction) of the flat portions is substantially constant. The insulating layer 304 has a substantially constant thickness (dimension in the Z direction) and is formed along the lower surface of the insulating layer 305.

[0050] Multiple lower electrodes 61B are arranged on multiple first inclined surfaces 305a. Multiple lower electrodes 61C are arranged on multiple second inclined surfaces 305b. As described above, since each of the first inclined surface 305a and the second inclined surface 305b is inclined with respect to the upper surface 301a of the substrate 301, i.e., the XY plane, the upper surfaces of each of the multiple lower electrodes 61B and each of the multiple lower electrodes 61C are also inclined with respect to the XY plane. Therefore, it can be said that the multiple first MR elements 50B and the multiple second MR elements 50C are arranged on inclined surfaces that are inclined with respect to the XY plane. The insulating layer 305 is a member for supporting each of the multiple first MR elements 50B and the multiple second MR elements 50C so that they are inclined with respect to the XY plane.

[0051] In this embodiment, the first inclined surface 305a is a curved surface. Therefore, the first MR element 50B curves along the curved surface (first inclined surface 305a). In this embodiment, for convenience, the direction of magnetization of the magnetization fixed layer 51 of the first MR element 50B is defined as a linear direction as described above. The W1 direction and -W1 direction, which are the directions of magnetization of the magnetization fixed layer 51 of the first MR element 50B, are also the directions in which the tangents that are in contact with the portion of the first inclined surface 305a near the first MR element 50B extend.

[0052] Similarly, in this embodiment, the second inclined surface 305b is a curved surface. Therefore, the second MR element 50C curves along the curved surface (second inclined surface 305b). In this embodiment, for convenience, the direction of magnetization of the magnetization fixed layer 51 of the second MR element 50C is defined as a linear direction as described above. The W2 direction and -W2 direction, which are the directions of magnetization of the magnetization fixed layer 51 of the second MR element 50C, are also the directions in which the tangents that are in contact with the portion of the second inclined surface 305b near the second MR element 50C extend.

[0053] As shown in Figure 5, the multiple first MR elements 50B are arranged so that multiple elements are lined up in the U direction and multiple elements are lined up in the V direction. Multiple first MR elements 50B are lined up in a row on one first inclined surface 305a. Similarly, the multiple second MR elements 50C are arranged so that multiple elements are lined up in the U direction and multiple elements are lined up in the V direction. Multiple second MR elements 50C are lined up in a row on one second inclined surface 305b. In this embodiment, the rows of multiple first MR elements 50B and rows of multiple second MR elements 50C are arranged alternately in a direction parallel to the V direction.

[0054] Furthermore, an adjacent first MR element 50B and a second MR element 50C may or may not be offset in a direction parallel to the U direction when viewed from the Z direction. Also, two first MR elements 50B adjacent to each other with one second MR element 50C in between may or may not be offset in a direction parallel to the U direction when viewed from the Z direction. Also, two second MR elements 50C adjacent to each other with one first MR element 50B in between may or may not be offset in a direction parallel to the U direction when viewed from the Z direction.

[0055] Multiple first MR elements 50B are connected in series by multiple lower electrodes 61B and multiple upper electrodes 62B. The connection method of the multiple first MR elements 50B will now be described in detail with reference to Figure 7. In Figure 7, reference numeral 61 indicates a lower electrode corresponding to any MR element 50, and reference numeral 62 indicates an upper electrode corresponding to any MR element 50. As shown in Figure 7, each lower electrode 61 has an elongated shape. A gap is formed between two adjacent lower electrodes 61 in the longitudinal direction. On the upper surface of the lower electrode 61, MR elements 50 are positioned near both ends in the longitudinal direction. Each upper electrode 62 also has an elongated shape and is positioned on two adjacent lower electrodes 61 in the longitudinal direction to electrically connect two adjacent MR elements 50.

[0056] Although not shown, one MR element 50 located at the end of a row of multiple MR elements 50 arranged in a single line is connected to another MR element 50 located at the end of an adjacent row of multiple MR elements 50 in a direction intersecting the longitudinal direction of the lower electrode 61. These two MR elements 50 are connected to each other by electrodes (not shown). The electrodes (not shown) may be electrodes connecting the lower surfaces of the two MR elements 50 or the upper surfaces of the two MR elements 50.

[0057] If the MR element 50 shown in Figure 7 is the first MR element 50B, then the lower electrode 61 shown in Figure 7 corresponds to the lower electrode 61B, and the upper electrode 62 shown in Figure 7 corresponds to the upper electrode 62B. In this case, the longitudinal direction of the lower electrode 61 is parallel to the U direction.

[0058] Similarly, multiple second MR elements 50C are connected in series by multiple lower electrodes 61C and multiple upper electrodes 62C. The explanation of the connection method for multiple first MR elements 50B described above also applies to the connection method for multiple second MR elements 50C. When the MR element 50 shown in Figure 7 is a second MR element 50C, the lower electrode 61 shown in Figure 7 corresponds to the lower electrode 61C, and the upper electrode 62 shown in Figure 7 corresponds to the upper electrode 62C. In this case, the longitudinal direction of the lower electrode 61 is parallel to the U direction.

[0059] Each of the multiple upper coil elements 82 extends in a direction parallel to the Y direction. Furthermore, the multiple upper coil elements 82 are arranged so as to be aligned in the X direction. In this embodiment in particular, when viewed from the Z direction, two upper coil elements 82 overlap each of the multiple first MR elements 50B and the multiple second MR elements 50C.

[0060] Each of the multiple lower coil elements 81 extends in a direction parallel to the Y direction. Furthermore, the multiple lower coil elements 81 are arranged so as to be aligned in the X direction. The shape and arrangement of the multiple lower coil elements 81 may be the same as or different from the shape and arrangement of the multiple upper coil elements 82. In the examples shown in Figures 5 and 6, the X-direction dimension of each of the multiple lower coil elements 81 is smaller than the X-direction dimension of each of the multiple upper coil elements 82. Also, the distance between two adjacent lower coil elements 81 in the X direction is smaller than the distance between two adjacent upper coil elements 82 in the X direction.

[0061] In the examples shown in Figures 5 and 6, the multiple lower coil elements 81 and the multiple upper coil elements 82 are electrically connected to form a coil 80 that applies a magnetic field parallel to the X direction to the free layers 53 of each of the multiple first MR elements 50B and the multiple second MR elements 50C. The coil 80 may also be configured to apply a magnetic field in the X direction to the free layers 53 of the first and second resistors R21, R22 of the first detection circuit 20 and the first and second resistors R31, R32 of the second detection circuit 30, and to apply a magnetic field in the -X direction to the free layers 53 of the third and fourth resistors R23, R24 of the first detection circuit 20 and the third and fourth resistors R33, R34 of the second detection circuit 30. The coil 80 may also be controlled by the processor 40.

[0062] Next, the first and second detection signals will be described. First, the first detection signal will be described with reference to Figure 3. When the intensity of the component of the target magnetic field parallel to the W1 direction changes, the resistance values ​​of each of the resistors R21 to R24 of the first detection circuit 20 change such that the resistance values ​​of resistors R21 and R23 increase while the resistance values ​​of resistors R22 and R24 decrease, or the resistance values ​​of resistors R21 and R23 decrease while the resistance values ​​of resistors R22 and R24 increase. As a result, the potentials of the signal output terminals E21 and E22 change. The first detection circuit 20 is configured to generate a signal corresponding to the potential of the signal output terminal E21 as the first detection signal S21, and a signal corresponding to the potential of the signal output terminal E22 as the first detection signal S22.

[0063] Next, the second detection signal will be described with reference to Figure 4. When the intensity of the component of the target magnetic field parallel to the W2 direction changes, the resistance values ​​of the resistors R31 to R34 of the second detection circuit 30 change such that the resistance values ​​of resistors R31 and R33 increase while the resistance values ​​of resistors R32 and R34 decrease, or the resistance values ​​of resistors R31 and R33 decrease while the resistance values ​​of resistors R32 and R34 increase. As a result, the potentials of the signal output terminals E31 and E32 change. The second detection circuit 30 is configured to generate a signal corresponding to the potential of the signal output terminal E31 as the second detection signal S31, and a signal corresponding to the potential of the signal output terminal E32 as the second detection signal S32.

[0064] Next, the operation of the processor 40 will be described. The processor 40 is configured to generate a first detection value and a second detection value based on the first detection signals S21, S22 and the second detection signals S31, S32. The first detection value is the detection value corresponding to the component of the target magnetic field in the direction parallel to the V direction. The second detection value is the detection value corresponding to the component of the target magnetic field in the direction parallel to the Z direction. Hereafter, the first detection value will be denoted by the symbol Sv and the second detection value will be denoted by the symbol Sz.

[0065] The processor 40 generates the first and second detection values ​​Sv and Sz, for example, as follows: First, the processor 40 generates the value Sa by performing a calculation that includes finding the difference S21-S22 between the first detection signal S21 and the first detection signal S22, and then generates the value Sb by performing a calculation that includes finding the difference S31-S32 between the second detection signal S31 and the second detection signal S32. Next, the processor 40 calculates the values ​​Sc and Sd using the following equations (1) and (2).

[0066] Sc = (Sb + Sa) / (2cosα) …(1) Sd = (Sb - Sa) / (2sinα) …(2)

[0067] The first detected value Sv may be the value Sc itself, or it may be the value Sc to which predetermined corrections such as gain adjustment and offset adjustment have been applied. Similarly, the second detected value Sz may be the value Sd itself, or it may be the value Sd to which predetermined corrections such as gain adjustment and offset adjustment have been applied.

[0068] Next, the structural features of the magnetic sensor 1 according to this embodiment will be described. Here, the MR element 50 and the lower electrode 61 together are referred to as the MR element structure and are denoted by reference numeral 70. The MR element structure 70 includes the lower electrode 61 and the MR element 50 disposed on the lower electrode 61. The MR element 50 includes a magnetization fixed layer 51 and a free layer 53. The MR element structure 70 is configured such that current flows in the stacking direction of the lower electrode 61 and the MR element 50.

[0069] First, the MR element structure 70 of the first example will be described. Figure 8 is a cross-sectional view showing the MR element structure 70 of the first example. Figure 9 is a cross-sectional view showing the MR element 50 and the lower electrode 61 of the MR element structure 70 shown in Figure 8.

[0070] Figure 8 shows a cross-section that intersects with an MR element 50 placed on an arbitrary inclined surface 305e, and is parallel to the VZ plane. Hereinafter, a cross-section parallel to the VZ plane will be referred to as a VZ cross-section. The VZ cross-section shown in Figure 8 may also be a VZ cross-section viewed from a position at the end of the U direction, similar to Figure 6. In this case, the MR element 50, the lower electrode 61, and the inclined surface 305e correspond to the first MR element 50B, the lower electrode 61B, and the first inclined surface 305a, respectively. Alternatively, the VZ cross-section shown in Figure 8 may also be a VZ cross-section viewed from a position at the end of the -U direction. In this case, the MR element 50, the lower electrode 61, and the inclined surface 305e correspond to the second MR element 50C, the lower electrode 61C, and the second inclined surface 305b, respectively.

[0071] Here, as shown in Figures 8 and 9, we define a first direction D1 and a second direction D2 parallel to the VZ plane. The first direction D1 is the direction along the inclined surface 305e and away from the reference plane. In this embodiment, the upper surface 301a of the substrate 301 (see Figure 6) is the reference plane. The Z direction is a single direction perpendicular to the reference plane (upper surface 301a of the substrate 301). The second direction D2 is the direction along the inclined surface 305e and approaching the reference plane (upper surface 301a of the substrate 301).

[0072] Furthermore, in the following explanation, the direction that is along the inclined surface 305e and parallel to the first direction D1 (parallel to the second direction D2) is simply referred to as the direction along the inclined surface 305e. This direction is both the direction along the inclined surface 305e and the direction in which the distance from the reference plane (the upper surface 301a of the substrate 301) changes.

[0073] The MR element 50 has a lower surface 50a facing the inclined surface 305e, an upper surface 50b opposite to the lower surface 50a, a first side surface 50c, and a second side surface 50d. The first side surface 50c connects the end of the lower surface 50a in the first direction D1 to the end of the upper surface 50b in the first direction D1. The second side surface 50d is located ahead of the first side surface 50c in the second direction D2. The second side surface 50d connects the end of the lower surface 50a in the second direction D2 to the end of the upper surface 50b in the second direction D2.

[0074] In Figure 8, the symbol P1 indicates a virtual plane that intersects the MR element 50 and is perpendicular to the inclined surface 305e. In this embodiment, the upper surface 50b of the MR element 50 is particularly curved. The virtual plane P1 includes the central axis C1 of the cylindrical surface when the upper surface 50b of the MR element 50 shown in Figure 8 is considered as part of a cylindrical surface, and intersects the MR element 50. Furthermore, the virtual plane P1 intersects the center of the upper surface 50b in the direction along the inclined surface 305e.

[0075] As shown in Figure 8, a portion of the first side surface 50c is inclined such that the distance between the portion of the first side surface 50c and the virtual plane P1 increases as it approaches the lower electrode 61. Similarly, the second side surface 50d is inclined such that the distance between the second side surface 50d and the virtual plane P1 increases as it approaches the lower electrode 61. Furthermore, the distance between the first side surface 50c and the second side surface 50d increases as it approaches the lower electrode 61.

[0076] In any cross-section parallel to the VZ plane, the second side surface 50d of the MR element 50 has a different shape from the first side surface 50c of the MR element 50. Specifically, the second side surface 50d has a shape asymmetrical with respect to the first side surface 50c with respect to the virtual plane P1. In any cross-section parallel to the inclined surface 305e, the distance between the first side surface 50c and the virtual plane P1 is greater than the distance between the second side surface 50d and the virtual plane P1 in the vicinity of the upper surface 61b of the lower electrode 61. In parts other than the vicinity of the upper surface 61b of the lower electrode 61, the distance between the first side surface 50c and the virtual plane P1 may be equal to the distance between the second side surface 50d and the virtual plane P1.

[0077] As shown in Figure 9, the first side surface 50c includes a first portion S1 and a second portion S2 that have different angles with respect to the inclined surface 305e. In particular, in the first example, the angle that the first portion S1 makes with respect to the inclined surface 305e is 0 or nearly 0. The first portion S1 extends along the upper surface 61b of the lower electrode 61.

[0078] The second portion S2 is positioned further from the inclined surface 305e than the first portion S1. The angle that the second portion S2 makes with the inclined surface 305e is greater than the angle that the first portion S1 makes with the inclined surface 305e. Also, the angle that the second portion S2 makes with respect to the direction parallel to the Z direction is smaller than the angle that the first portion S1 makes with respect to the direction parallel to the Z direction. Furthermore, the second portion S2 is inclined such that the distance between the second portion S2 and the virtual plane P1 (see Figure 8) increases as it approaches the lower electrode 61. The distance between the second portion S2 and the virtual plane P1 is less than or equal to the minimum distance between the first portion S1 and the virtual plane P1.

[0079] In the example shown in Figure 9, the first part S1 and the second part S2 are both curved surfaces. The angle that the first part S1 makes with the inclined surface 305e may be the angle between a first tangent line and a second tangent line, both parallel to the VZ plane. The first tangent line is tangent to any first point on the first part S1. The second tangent line is tangent to the inclined surface 305e in the vicinity of the first point. If the first and second tangent lines are parallel to each other, the angle that the first part S1 makes with the inclined surface 305e is 0. The angle that the second part S2 makes with the inclined surface 305e may be defined in the same way as the angle that the first part S1 makes with the inclined surface 305e. Note that the first part S1 and the second part S2 are not limited to curved surfaces, but may also be planes.

[0080] As described above, the MR element 50 includes a magnetized fixed layer 51, which is a first magnetic layer, and a free layer 53, which is a second magnetic layer. In this embodiment in particular, the magnetized fixed layer 51 is interposed between the inclined surface 305e and the free layer 53. At least a portion of the first portion S1 is made up of the side surface of the magnetized fixed layer 51. At least a portion of the second portion S2 is made up of the side surface of the free layer 53. In particular, in the first example, the second portion S2 is made up of the side surface of the magnetized fixed layer 51 in addition to the side surface of the free layer 53. That is, the second portion S2 is formed from the magnetized fixed layer 51 to the free layer 53.

[0081] The first side surface 50c further includes a third portion S3. The third portion S3 is located closer to the inclined surface 305e than the first portion S1. The third portion S3 is also located ahead of the first direction D1 when viewed from the first portion S1.

[0082] As shown in Figure 9, the second side surface 50d includes a fourth portion S4 and a fifth portion S5, each having different angles with respect to the inclined surface 305e. The fifth portion S5 is located further from the inclined surface 305e than the fourth portion S4. The angle that the fifth portion S5 makes with respect to the inclined surface 305e is greater than the angle that the fourth portion S4 makes with respect to the inclined surface 305e. Also, the angle that the fifth portion S5 makes with respect to the direction parallel to the Z direction is smaller than the angle that the fourth portion S4 makes with respect to the direction parallel to the Z direction.

[0083] The fourth portion S4 is inclined such that the distance between the fourth portion S4 and the virtual plane P1 (see Figure 8) increases as it approaches the lower electrode 61. Similarly, the fifth portion S5 is inclined such that the distance between the fifth portion S5 and the virtual plane P1 (see Figure 8) increases as it approaches the lower electrode 61. The distance between the fifth portion S5 and the virtual plane P1 is less than or equal to the minimum distance between the fourth portion S4 and the virtual plane P1.

[0084] In the example shown in Figure 9, the fourth portion S4 and the fifth portion S5 are both curved surfaces. However, the fourth portion S4 and the fifth portion S5 may also be planes.

[0085] At least a portion of the fourth portion S4 is composed of the sides of the magnetization fixed layer 51. At least a portion of the fifth portion S5 is composed of the sides of the free layer 53. The entire fourth portion S4 may be composed of the sides of the magnetization fixed layer 51, and the entire fifth portion S5 may be composed of the sides of the free layer 53. Alternatively, a portion of each of the fourth portion S4 and the fifth portion S5 may be composed of the sides of the gap layer 52. In this case, the boundary between the first portion S1 and the second portion S2 may be located on the sides of the gap layer 52.

[0086] As shown in Figure 8, the lower electrode 61 has a lower surface 61a facing the inclined surface 305e, an upper surface 61b opposite to the lower surface 61a, a third side surface 61c, and a fourth side surface 61d. The third side surface 61c connects the end of the lower surface 61a in the first direction D1 to the end of the upper surface 61b in the first direction D1.

[0087] The fourth side surface 61d is located along the upper surface of the insulating layer 305, away from the third side surface 61c. Hereinafter, first and second examples of the fourth side surface 61d will be described. First, the first example of the fourth side surface 61d will be described with reference to Figure 10. Figure 10 is a cross-sectional view showing the first example of the fourth side surface 61d. In the first example, the lower electrode 61 is formed from the inclined surface 305e to the flat surface 305d. The fourth side surface 61d is located above the flat surface 305d and connects the end of the lower surface 61a and the end of the upper surface 61b above the flat surface 305d.

[0088] Next, a second example of the fourth side surface 61d will be described with reference to Figure 11. Figure 11 is a cross-sectional view showing the second example of the fourth side surface 61d. In the second example, the lower electrode 61 is entirely positioned on the inclined surface 305e. The fourth side surface 61d is located above the inclined surface 305e. The fourth side surface 61d connects the end of the lower surface 61a in the second direction D2 to the end of the upper surface 61b in the second direction D2.

[0089] Note that Figure 6 shows the lower electrode 61 having the fourth side surface 61d shown in Figure 11. However, the lower electrode 61 in Figure 6 may also have the fourth side surface 61d shown in Figure 10.

[0090] The MR element structure 70 has a lower surface 70a facing the inclined surface 305e and an upper surface 70b opposite to the lower surface 70a. The lower surface 70a of the MR element structure 70 is formed by the lower surface 61a of the lower electrode 61. The upper surface 70b of the MR element structure 70 is formed by the upper surface 50b of the MR element 50.

[0091] The MR element structure 70 further has a first surface 70c that connects the lower surface 70a and the upper surface 70b. The first surface 70c is composed of the first side surface 50c of the MR element 50, the third side surface 61c of the lower electrode 61, and a portion of the upper surface 61b of the lower electrode 61 that is not covered by the MR element 50C.

[0092] The first surface 70c includes two steps. Specifically, the first surface 70c includes a first step between the first portion S1 and the third portion S3 of the first side surface 50c, and a second step between the third portion S3 of the first side surface 50c and the third side surface 61c of the lower electrode 61. The first step exists on the MR element 50 of the MR element structure 70. The second step exists between the MR element 50 and the lower electrode 61.

[0093] The MR element structure 70 further has a second surface 70d that connects the lower surface 70a and the upper surface 70b in the direction away from the first surface 70c along the upper surface of the insulating layer 305. The second surface 70d is composed of the second side surface 50d of the MR element 50, the fourth side surface 61d of the lower electrode 61, and the remaining portion of the upper surface 61b of the lower electrode 61 that is not covered by the MR element 50C. The second surface 70d contains fewer steps than the first surface 70c. That is, the second surface 70d contains one step between the second side surface 50d and the fourth side surface 61d.

[0094] In any cross-section parallel to the VZ plane, the second surface 70d has a different shape from the first surface 70c. Specifically, the second surface 70d has a shape that is asymmetrical with respect to the first surface 70c with respect to the virtual plane P1 as the center.

[0095] Next, we will describe the MR element structure 70 of the second example. Figure 12 is a cross-sectional view showing the MR element structure 70 of the second example.

[0096] In the second example, the shape of the first side surface 50c of the MR element 50 is different from that of the first example. In the second example, the first side surface 50c of the MR element 50 does not include the third portion S3 (see Figure 9). Also, in the second example, in any cross section parallel to the VZ plane, the first side surface 50c and the second side surface 50d of the MR element 50 have substantially symmetric or nearly symmetric shapes. Specifically, the first side surface 50c has a shape that is symmetric or nearly symmetric with respect to the second side surface 50d with respect to the virtual plane P1. In any cross section parallel to the inclined surface 305e, the distance between the first side surface 50c and the virtual plane P1 is equal to or approximately equal to the distance between the second side surface 50d and the virtual plane P1.

[0097] Furthermore, in the second example, the descriptions of the fourth and fifth parts S4 and S5 of the second side 50d in the first example also apply to the first and second parts S1 and S2 of the first side 50c in the second example (see Figure 9). If we replace the fourth and fifth parts S4 and S5 in the descriptions of the fourth and fifth parts S4 and S5 of the second side 50d in the first example with the first and second parts S1 and S2, respectively, we get the descriptions of the first and second parts S1 and S2 of the first side 50c in the second example.

[0098] In the second example, the upper surface 61b of the lower electrode 61 includes a first portion 61b1, a second portion 61b2, and a third portion 61b3. The MR element 50 is positioned on the first portion 61b1. The second portion 61b2 is connected to the third side surface 61c of the lower electrode 61. Each of the first and second portions 61b1 and 61b2 extends along the inclined surface 305e. The second portion 61b2 is positioned closer to the inclined surface 305e than the first portion 61b1. The third portion 61b3 connects the first portion 61b1 and the second portion 61b2.

[0099] In the second example, the first surface 70c of the MR element structure 70 is composed of the first side surface 50c of the MR element 50, a portion of the first part 61b1 of the upper surface 61b that is not covered by the MR element 50, the second and third parts 61b2 and 61b3 of the upper surface 61b, and the third side surface 61c. The first surface 70c includes a first step between the first side surface 50c of the MR element 50 and the third part 61b3 of the upper surface 61b of the lower electrode 61, and a second step between the third side surface 61c of the lower electrode 61 and the third part 61b3 of the upper surface 61b of the lower electrode 61. The first step exists between the MR element 50 and the lower electrode 61. The second step exists on the lower electrode 61.

[0100] Next, the operation and effects of the magnetic sensor 1 according to this embodiment will be described. In this embodiment, the first surface 70c of the MR element structure 70 includes first and second steps. In the first example, the first step exists on the MR element 50 of the MR element structure 70. If the first step does not exist, the first side surface 50c of the MR element 50 changes smoothly from the lower surface 50a to the upper surface 50b of the MR element 50. If the dimensions of the lower surface 50a and the upper surface 50b of the MR element 50 are made the same and compared in the direction along the inclined surface 305e, the distance between the first side surface 50c of the MR element 50 and the upper electrode 62 becomes larger than when the first step does not exist. As a result, according to this embodiment, it is possible to suppress short circuits between the first side surface 50c and the upper electrode 62.

[0101] In the second example, the second step is formed on the lower electrode 61. This allows the distance between the lower electrode 61 and the upper electrode 62 to be increased compared to the case where the second step does not exist. As a result, according to this embodiment, it is possible to suppress short circuits between the lower electrode 61 and the upper electrode 62.

[0102] Furthermore, in this embodiment, the magnetization fixed layer 51 is interposed between the inclined surface 305e and the free layer 53. When comparing the dimensions of the upper surface 50b of the MR element 50 in the direction along the inclined surface 305e, the dimensions of the magnetization fixed layer 51 in the direction along the inclined surface 305e are larger than when the first side surface 50c does not include the first portion S1. As a result, according to this embodiment, the volume of the magnetization fixed layer 51 can be increased, and deviation in the direction of magnetization of the magnetization fixed layer 51 can be suppressed.

[0103] Furthermore, in this embodiment, the second side surface 50d includes a fourth portion S4 and a fifth portion S5, which have different angles with respect to the inclined surface 305e. In particular, in this embodiment, the angle that the fifth portion S5 makes with respect to the inclined surface 305e is greater than the angle that the fourth portion S4 makes with respect to the inclined surface 305e. If the second side surface 50d does not include the fifth portion S5, that is, if the entire second side surface 50d is substantially the fourth portion S4, the angle that the second side surface 50d makes with respect to the inclined surface 305e becomes smaller overall. In this case, the second side surface 50d has a gentle taper shape. The area where the upper electrode 62 and the second side surface 50d face each other increases as the taper becomes gentler.

[0104] In contrast, in this embodiment, the second side surface 50d includes a fifth portion S5 in addition to the fourth portion S4. When comparing the dimensions of the lower surface 50a of the MR element 50 in the direction along the inclined surface 305e, the area where the upper electrode 62 and the second side surface 50d face each other is smaller than when the second side surface 50d does not include the fifth portion S5. Thus, according to this embodiment, 2nd side 50d This prevents a short circuit between the upper electrode 62 and the lower electrode 62.

[0105] Furthermore, in this embodiment, at least a portion of the fourth portion S4 belongs to the magnetization fixed layer 51. At least a portion of the fifth portion S5 belongs to the free layer 53. When comparing the dimensions of the upper surface 50b of the MR element 50 in the direction along the inclined surface 305e, the dimensions of the free layer 53 in the direction along the inclined surface 305e are smaller than when the second side surface 50d does not include the fifth portion S5. The direction along the inclined surface 305e is perpendicular to the longitudinal direction (parallel to the U direction) of the MR element 50 and is the short-side direction of the MR element 50. Therefore, according to this embodiment, the dimensions of the MR element 50 in the short-side direction can be reduced, thereby suppressing a decrease in the shape anisotropy (shape magnetic anisotropy) of the free layer 53.

[0106] Furthermore, the shape anisotropy (shape magnetic anisotropy) of the free layer 53 also changes depending on the angle that the side surface of the free layer 53 (part of the second side surface 50d) makes with respect to the inclined surface 305e. That is, as the above angle decreases, the shape anisotropy (shape magnetic anisotropy) of the free layer 53 decreases. In this embodiment, since a fifth portion S5 is formed in the free layer 53, the above angle becomes larger than when the fifth portion S5 does not exist. As a result, according to this embodiment, it is possible to suppress the decrease in the shape anisotropy (shape magnetic anisotropy) of the free layer 53.

[0107] Furthermore, in this embodiment, when comparing the dimensions of the upper surface 50b of the MR element 50 in the direction along the inclined surface 305e, the dimensions of the magnetization fixed layer 51 in the direction along the inclined surface 305e are larger than when the second side surface 50d does not include the fourth portion S4. As a result, according to this embodiment, the volume of the magnetization fixed layer 51 can be increased, and the shift in the direction of magnetization of the magnetization fixed layer 51 can be suppressed.

[0108] Here, the MR element structure 70 of the third example will be briefly described. The MR element structure 70 of the third example includes the MR element 50 of the second example and the lower electrode 61 of the first example. In this embodiment, the set of the MR element 50 of the first or second example and the MR element 50 of the third example can be the set of the first MR element 50B and the second MR element 50C in this embodiment. For example, the first MR element 50B may be the MR element 50 of the first or second example, and the second MR element 50C may be the MR element 50 of the third example. In this case, each of the first and second surfaces 70c, 70d of the MR element structure 70 that includes the second MR element 50C includes one step.

[0109] Alternatively, the first MR element 50B and the second MR element 50C may both be the MR element 50 of the first or second example.

[0110] [Differentiation] Next, first and second modifications of the magnetic sensor 1 according to this embodiment will be described. First, the first modification will be described with reference to Figures 13 and 14. Figure 13 is a cross-sectional view showing the MR element structure in the first modification. Figure 14 is a cross-sectional view showing the magnetoresistive element and lower electrode of the MR element structure shown in Figure 13.

[0111] Figure 13 shows a VZ cross-section intersecting an MR element 50 placed on an arbitrary inclined surface 305f. This VZ cross-section may be a VZ cross-section of the MR element 50 viewed from a position at the end of the U direction, similar to Figure 6. In this case, the MR element 50, the lower electrode 61, and the inclined surface 305f correspond to the second MR element 50C, the lower electrode 61C, and the second inclined surface 305b, respectively. Alternatively, the VZ cross-section shown in Figure 13 may be a VZ cross-section of the MR element 50 viewed from a position at the end of the -U direction. In this case, the MR element 50, the lower electrode 61, and the inclined surface 305f correspond to the first MR element 50B, the lower electrode 61B, and the first inclined surface 305a, respectively.

[0112] Here, as shown in Figures 13 and 14, we define a third direction D3 and a fourth direction D4 parallel to the VZ plane. The third direction D3 is the direction along the inclined surface 305f and is the direction away from the reference plane (the upper surface 301a of the substrate 301). The fourth direction D4 is the direction along the inclined surface 305f and is the direction approaching the reference plane (the upper surface 301a of the substrate 301).

[0113] Furthermore, in the following explanation, the direction that is along the inclined surface 305f and parallel to the third direction D3 (parallel to the fourth direction D4) is simply referred to as the direction along the inclined surface 305f. This direction is both the direction along the inclined surface 305f and the direction in which the distance from the reference plane (the upper surface 301a of the substrate 301) changes.

[0114] In Figure 13, the symbol P2 represents a virtual plane that intersects the MR element 50 and is perpendicular to the inclined surface 305f. The virtual plane P2 includes the central axis C2 of the cylindrical surface when the upper surface 50b of the MR element 50 shown in Figure 13 is considered as part of a cylindrical surface, and intersects the MR element 50. Furthermore, the virtual plane P2 intersects the center of the upper surface 50b in the direction along the inclined surface 305f.

[0115] The description of the MR element structure 70 in the first example also applies to the MR element structure 70 in the first modified example, with the exception of several points described below. By replacing the inclined surface 305e, the first direction D1, the second direction D2, and the virtual plane P1 in the description of the MR element structure 70 in the first example with the inclined surface 305f, the third direction D3, the fourth direction D4, and the virtual plane P2, respectively, the description becomes that of the MR element structure 70 in the first modified example.

[0116] In the first modification, the shape of the first side surface 50c of the MR element 50 is different from that of the first example. In the first modification, the first side surface 50c does not include the third portion S3.

[0117] In the first modified example, the first surface 70c of the MR element structure 70 is composed of the first side surface 50c of the MR element 50 and the third side surface 61c of the lower electrode 61. The first surface 70c includes a step between the second portion S2 of the first side surface 50c and the third side surface 61c of the lower electrode 61.

[0118] Next, a second modified example will be described with reference to Figure 15. Figure 15 is a cross-sectional view showing the MR element structure in the second modified example.

[0119] In the second modification, the shape of the first side surface 50c of the MR element 50 is different from that of the first modification. In the second modification, the first portion S1 of the first side surface 50c is composed of the side surface of the free layer 53 in addition to the side surface of the magnetization fixed layer 51. That is, the first portion S1 is formed from the magnetization fixed layer 51 to the free layer 53.

[0120] [Second Embodiment] Next, with reference to Figure 16, a magnetic sensor 1 according to a second embodiment of the present invention will be described. Figure 16 is a cross-sectional view showing a part of the magnetic sensor 1 according to this embodiment.

[0121] In this embodiment, the overall shape of each of the multiple convex surfaces 305c of the insulating layer 305 is a triangular roof shape formed by moving the triangular shape of the convex surface 305c shown in Figure 16 along a direction parallel to the U direction. Furthermore, each of the multiple first inclined surfaces 305a and the multiple second inclined surfaces 305b of the insulating layer 305 is a plane. Each of the multiple first inclined surfaces 305a is a plane parallel to the U direction and the W1 direction. Each of the multiple second inclined surfaces 305b is a plane parallel to the U direction and the W2 direction.

[0122] The insulating layer 305 may include a plurality of protrusions that form a plurality of convex surfaces 305c, similar to the example shown in Figure 6. Alternatively, the insulating layer 305 may include a plurality of grooves arranged in a direction parallel to the V direction. Each of the plurality of grooves has a first wall surface corresponding to the first inclined surface 305a and a second wall surface corresponding to the second inclined surface 305b. A single convex surface 305c is formed by the first wall surface of one groove and the second wall surface of another groove adjacent to this groove on the -V direction side.

[0123] In the example shown in Figure 16, each of the multiple grooves further has a bottom surface corresponding to the flat surface 305d. However, each of the multiple grooves does not necessarily have to have a bottom surface.

[0124] Other configurations, operations, and effects in this embodiment are the same as those in the first embodiment.

[0125] It should be noted that 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 shapes of the first and second surfaces 70c and 70d of the MR element structure 70 are not limited to the examples shown in each embodiment, but are arbitrary. The first surface 70c may include three or more steps. In this case, the second surface 70d may include fewer steps than the number of steps on the first surface 70c.

[0126] Furthermore, the magnetic sensor 1 may also include a third detection circuit configured to detect a component of the target magnetic field in a direction parallel to the XY plane and to generate at least one third detection signal corresponding to this component. In this case, the processor 40 may be configured to generate a detection value corresponding to the component of the target magnetic field in a direction parallel to the U direction based on at least one third detection signal. The third detection circuit may be integrated with the first and second detection circuits 20, 30, or it may be included in a separate chip from the first and second detection circuits 20, 30.

[0127] As described above, the magnetic sensor of the present invention comprises a substrate having a reference plane, a support member disposed on the substrate and having an inclined surface tilted with respect to the reference plane, and a magnetic detection element structure disposed on the inclined surface and having a lower surface facing the inclined surface, an upper surface on the opposite side of the lower surface, and a first surface connecting the lower surface and the upper surface and including two steps.

[0128] In the magnetic sensor of the present invention, the magnetic detection element structure may further have a second surface connecting the lower surface and the upper surface at a point in the direction away from the first surface along the inclined surface. The second surface may have a shape asymmetrical with respect to the first surface with respect to a virtual plane that intersects the magnetic detection element structure and is perpendicular to the inclined surface. The second surface may include fewer steps than the first surface.

[0129] Furthermore, in the magnetic sensor of the present invention, the magnetic detection element structure may include a lower electrode and a magnetic detection element disposed on the lower electrode, and may be configured so that current flows in the stacking direction of the lower electrode and the magnetic detection element. The magnetic detection element may include a free layer having magnetization whose direction can change in response to an external magnetic field, and a magnetization-fixed layer having magnetization whose direction is fixed and interposed between the free layer and the inclined surface. One of the two steps may be located on the magnetic detection element, and the other step may be located between the magnetic detection element and the lower electrode. Alternatively, one of the two steps may be located between the magnetic detection element and the lower electrode, and the other step may be located on the lower electrode.

[0130] Furthermore, in the magnetic sensor of the present invention, the first surface may include a curved portion.

[0131] Furthermore, in the magnetic sensor of the present invention, the inclined surface may be a curved surface, or the inclined surface may be a flat surface.

[0132] Furthermore, the magnetic sensor of the present invention may further include an insulating layer and an upper electrode. The magnetic detection element structure may include a lower electrode and a magnetic detection element disposed on the lower electrode. The upper electrode may be positioned to sandwich the magnetic detection element between itself and the lower electrode. The insulating layer may be disposed around the magnetic detection element structure between the lower electrode and the upper electrode.

[0133] Furthermore, in the magnetic sensor of the present invention, the support member may have a convex surface that protrudes in a direction away from the reference plane. The convex surface may include an inclined surface and another inclined surface that is inclined with respect to the reference plane and oriented in a direction different from the inclined surface. In this case, the magnetic sensor of the present invention may further include another magnetic detection element structure that is positioned on the other inclined surface and has a lower surface facing the other inclined surface, an upper surface opposite to the lower surface, and two surfaces connecting the lower surface and the upper surface. Each of the two surfaces of the other magnetic detection element structure may include fewer steps than the first surface. [Explanation of symbols]

[0134] 1…Magnetic sensor, 20…First detection circuit, 30…Second detection circuit, 40…Processor, 50…MR element, 50B…First MR element, 50C…Second MR element, 51…Magnetic fixed layer, 52…Gap layer, 53…Free layer, 61,61B,61C…Lower electrode, 62,62B,62C…Upper electrode, 70…MR element structure, 70a…Bottom surface, 70b…Top surface, 70c…First surface, 70d…Second Surface, 80...coil, 81...lower coil element, 82...upper coil element, 100...magnetic sensor device, 301...substrate, 301a...top surface, 302~305,307~310...insulating layer, 305a...first inclined surface, 305b...second inclined surface, 305c...convex surface, 305d...flat surface, 305e,305f...inclined surfaces, S1...first part, S2...second part, S3...third part, S4...fourth part.

Claims

1. A substrate having a reference plane, A support member is placed on the substrate and has an inclined surface that is inclined with respect to the reference plane, A magnetic detection element structure is provided, which is positioned on the inclined surface and has a lower surface facing the inclined surface, an upper surface opposite to the lower surface, and a first surface connecting the lower surface and the upper surface and including two steps. Equipped with an upper electrode, The magnetic detection element structure includes a lower electrode and a magnetic detection element disposed on the lower electrode, and is configured such that current flows in the stacking direction of the lower electrode and the magnetic detection element. The upper electrode is positioned to sandwich the magnetic detection element between itself and the lower electrode. One of the two steps is present in the magnetic detection element. The other of the two steps is located between the magnetic detection element and the lower electrode. The magnetic detection element includes a free layer having magnetization whose direction can change in response to an external magnetic field, and a magnetization-fixing layer having magnetization whose direction is fixed and interposed between the free layer and the inclined surface. The magnetic detection element has a lower surface facing the inclined surface, an upper surface opposite to the lower surface, a first side surface that constitutes a part of the first surface, and a second side surface. The first side surface includes a first portion and a second portion, and a third portion, which have different angles with respect to the inclined surface. The second portion is positioned further from the inclined surface than the first portion and is formed from the magnetized fixed layer to the free layer, The third portion is positioned closer to the inclined surface than the first portion. One of the two steps is located between the first part and the third part. A magnetic sensor characterized in that the angle the first side surface makes with respect to the inclined surface changes substantially discontinuously between the first portion and the second portion and between the first portion and the third portion.

2. The magnetic sensor according to claim 1, further characterized in that the magnetic detection element structure has a second surface connecting the lower surface and the upper surface at a point in the direction away from the first surface along the inclined surface.

3. The magnetic sensor according to claim 2, characterized in that the second surface has a shape asymmetric with respect to the first surface, with respect to a virtual plane that intersects the magnetic detection element structure and is perpendicular to the inclined surface.

4. The magnetic sensor according to claim 3, characterized in that the second surface includes fewer steps than the first surface.

5. The magnetic sensor according to claim 1, characterized in that the first surface includes a curved portion.

6. The magnetic sensor according to claim 1, characterized in that the inclined surface is a curved surface.

7. The magnetic sensor according to claim 1, characterized in that the inclined surface is a flat surface.

8. Furthermore, it is equipped with an insulating layer, The magnetic sensor according to claim 1, characterized in that the insulating layer is disposed around the magnetic detection element structure between the lower electrode and the upper electrode.

9. The support member has a convex surface that protrudes in a direction away from the reference plane, The magnetic sensor according to claim 1, characterized in that the convex surface includes the inclined surface and another inclined surface that is inclined with respect to the reference plane and oriented in a direction different from the inclined surface.

10. Furthermore, the magnetic detection element structure is provided, which is positioned on the other inclined surface and has a lower surface facing the other inclined surface, an upper surface opposite to the lower surface, and two surfaces connecting the lower surface and the upper surface. The magnetic sensor according to claim 9, characterized in that each of the two surfaces of the other magnetic detection element structure includes fewer steps than the first surface.

Images