Sensor

Abstract

To realize a sensor capable of suppressing generation of cracks.SOLUTION: A magnetic sensor 1 includes an insulating layer 305 including a protruding surface 305c, a first MR element 50B, and a second MR element 50C. The first MR element 50B is disposed on a first inclined surface 305a of the protruding surface 305c. The second MR element 50C is disposed on a second inclined surface 305b of the protruding surface 305c. The protruding surface 305c includes first to third curved surface portions 305c1 to 305c3. The second and third curved surface portions 305c2, 305c3 are curved surfaces, each protruding in a direction approaching an upper surface 301a of a substrate 301.SELECTED DRAWING: Figure 13

Description

[Technical Field]

[0001] The present invention relates to a sensor having a sensor element arranged on a convex surface. [Background technology]

[0002] In recent years, magnetic sensors using magnetoresistive elements have been used in a variety of applications. In systems including magnetic sensors, it is sometimes necessary to detect a magnetic field containing a component perpendicular to the surface of the substrate using a magnetoresistive element provided on a substrate. In this case, the magnetic field containing a component perpendicular to the surface of the substrate can be detected by providing a soft magnetic material that converts 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.

[0003] Patent Document 1 discloses a three-axis magnetic sensor in which an X-axis sensor, a Y1-axis sensor, and a Y2-axis sensor are provided on a substrate. The multiple magnetoresistance effect elements that make up the Y1-axis sensor and the Y2-axis sensor are formed on the slopes of multiple protrusions that have trapezoidal cross sections and are formed on the substrate. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-212275 Summary of the Invention [Problem to be solved by the invention]

[0005] In a support member for supporting a magnetoresistive element, such as the triaxial magnetic sensor disclosed in Patent Document 1, which has a structure in which multiple trapezoidal protrusions protrude from a flat portion, the surfaces of the protrusions and the flat portion are discontinuous at the boundaries between the protrusions and the flat portion. As a result, the surface of the support member is not smooth. In a magnetic sensor equipped with a support member having the above structure, cracks may occur in the support member near the boundaries between the protrusions and the flat portion during the manufacturing process or during use of the magnetic sensor.

[0006] The above problem is not limited to magnetic sensors, but applies to all sensors in which the sensor element is formed on an inclined surface.

[0007] The present invention has been made in consideration of such problems, and its purpose is to provide a sensor in which a functional layer of a sensor element is formed on an inclined convex surface, and which is capable of suppressing the occurrence of cracks. [Means for solving the problem]

[0008] The sensor of the present invention is configured to detect a predetermined physical quantity. The sensor of the present invention includes a substrate having an upper surface, a support member disposed on the substrate, and a sensor element configured to change physical properties in response to the predetermined physical quantity. The support member has a convex surface that protrudes away from the upper surface of the substrate and at least a portion of which is inclined relative to the upper surface of the substrate. The convex surface has an upper end furthest from the upper surface of the substrate. The sensor element includes a functional layer that constitutes at least a portion of the sensor element. The functional layer is disposed on the convex surface. The convex surface includes a first curved surface portion including the upper end, and a second curved surface portion that is continuous with the first curved surface portion and is located between the first curved surface portion and the upper surface of the substrate in a direction perpendicular to the upper surface of the substrate. The first curved surface portion is a curved surface that is convex in a direction away from the upper surface of the substrate. The second curved surface portion is a curved surface that is convex in a direction approaching the upper surface of the substrate. The radius of curvature of the second curved surface portion in a cross section perpendicular to the upper surface of the substrate is smaller than the radius of curvature of the first curved surface portion in a cross section perpendicular to the upper surface of the substrate and is 0.3 μm or more. The radius of curvature of the first curved surface portion in a cross section perpendicular to the upper surface of the substrate is 4.25 μm or more and 5.45 μm or less. [Effects of the Invention]

[0009] In the sensor of the present invention, the support member has a convex surface including a first curved surface portion and a second curved surface portion each having the above-mentioned characteristics, thereby achieving the effect of suppressing the occurrence of cracks in a sensor in which the functional layer of the sensor element is formed on an inclined convex surface. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a perspective view showing a magnetic sensor according to an embodiment of the present invention. [Figure 2] 1 is a functional block diagram showing a configuration of a magnetic sensor device including a magnetic sensor according to an embodiment of the present invention. [Figure 3] FIG. 2 is a circuit diagram showing a circuit configuration of a first detection circuit in one embodiment of the present invention. [Figure 4]FIG. 4 is a circuit diagram showing a circuit configuration of a second detection circuit in one embodiment of the present invention. [Figure 5] 1 is a plan view showing a part of a magnetic sensor according to an embodiment of the present invention. [Figure 6] 1 is a cross-sectional view showing a part of a magnetic sensor according to an embodiment of the present invention. [Figure 7] 1 is a side view showing a magnetoresistive effect element according to an embodiment of the present invention; [Figure 8] 5A to 5C are cross-sectional views showing a step in a method of manufacturing a magnetic sensor according to an embodiment of the present invention. [Figure 9] 9 is a cross-sectional view showing a step subsequent to the step shown in FIG. 8. [Figure 10] 10 is a cross-sectional view showing a step subsequent to the step shown in FIG. [Figure 11] FIG. 11 is a cross-sectional view showing a step subsequent to the step shown in FIG. [Figure 12] 5A and 5B are explanatory diagrams illustrating the shape of a support member according to an embodiment of the present invention. [Figure 13] 1 is an explanatory diagram for explaining the shape of a convex surface according to an embodiment of the present invention; [Figure 14] FIG. 10 is an explanatory diagram showing a graph of a function representing the shape of a convex surface according to an embodiment of the present invention. [Figure 15] FIG. 15 is an explanatory diagram showing a graph of the first derivative of the function shown in FIG. [Figure 16] FIG. 15 is an explanatory diagram showing a graph of the second derivative of the function shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0011] The embodiments of the present invention described below relate to a sensor configured to detect a predetermined physical quantity. In the embodiments, the sensor includes a sensor element configured to change its physical properties in response to the predetermined physical quantity. For example, the predetermined physical quantity may be at least one of the direction and intensity of a target magnetic field, which is a magnetic field to be detected. In this case, the sensor element may be a magnetic detection element configured to detect changes in at least one of the direction and intensity of the target magnetic field. A sensor including a magnetic detection element is also called a magnetic sensor. The magnetic sensor is configured to detect at least one of the direction and intensity of the target magnetic field. Below, the embodiments will be described in detail, taking as an example a case where the sensor is a magnetic sensor.

[0012] First, the configuration of a magnetic sensor according to an embodiment of the present invention will be described with reference to Fig. 1 and Fig. 2. Fig. 1 is a perspective view showing the magnetic sensor 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. The magnetic sensor 1 according to the present embodiment corresponds to the "sensor" in the present invention.

[0013] As shown in Fig. 1, the magnetic sensor 1 is in the form of a rectangular parallelepiped chip. The magnetic sensor 1 has an upper surface 1a and a lower surface located on opposite sides, and four side surfaces connecting the upper surface 1a and the lower surface. The magnetic sensor 1 also has a plurality of electrode pads provided on the upper surface 1a.

[0014] Here, with reference to FIG. 1, the reference coordinate system in this 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, an X direction, a Y direction, and a Z direction are defined. The X direction, the Y direction, and the Z direction are orthogonal to one another. In this embodiment, the direction perpendicular to the top surface 1a of the magnetic sensor 1 and the direction from the bottom surface of the magnetic sensor 1 toward the top surface 1a is particularly defined as the Z direction. Furthermore, 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 that define 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.

[0015] Hereinafter, the position further in the Z direction than the reference position will be referred to as "above," and the position opposite "above" the reference position will be referred to as "below." Furthermore, with regard to the components of the magnetic sensor 1, the surface located at the end in the Z direction will be referred to as the "top surface," and the surface located at the end in the -Z direction will be referred to as the "bottom surface." Furthermore, the expression "when viewed from the Z direction" means viewing the object from a position away in the Z direction.

[0016] 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 this embodiment, the plurality of magnetic detection elements are particularly a plurality of magnetoresistive effect elements. Hereinafter, the magnetoresistive effect elements will be referred to as MR elements.

[0017] The multiple detection signals generated by the first and second detection circuits 20, 30 are processed by a processor 40. The magnetic sensor 1 and the processor 40 constitute a magnetic sensor device 100. The processor 40 is configured to process the multiple detection signals generated by the first and second detection circuits 20, 30 to generate first and second detection values ​​that correspond to components of the magnetic field in two different directions at a predetermined reference position. 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).

[0018] The processor 40 may be included in, for example, 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 the plurality of electrode pads of the magnetic sensor 1, the plurality of electrode pads of the support, and a plurality of bonding wires. When 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 with the lower surface of the magnetic sensor 1 facing the upper surface of the support.

[0019] Next, the first and second detection circuits 20, 30 will be described with reference to Fig. 3 to Fig. 6. Fig. 3 is a circuit diagram showing the circuit configuration of the first detection circuit 20. Fig. 4 is a circuit diagram showing the circuit configuration of the second detection circuit 30. Fig. 5 is a plan view showing a part of the magnetic sensor 1. Fig. 6 is a cross-sectional view showing a part of the magnetic sensor 1.

[0020] As shown in FIG. 5, the U direction and V direction are defined as follows: The U direction is the direction rotated from the X direction toward the -Y direction. The V direction is the direction rotated from the Y direction toward the X direction. In this embodiment, the U direction is defined as the direction rotated by α from the X direction toward the -Y direction, and the V direction is defined as the direction rotated by α from the Y direction toward the X direction. Note that α is an angle greater than 0° and smaller than 90°. In one example, α is 45°. 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.

[0021] As shown in FIG. 6, the W1 direction and the W2 direction are defined as follows: The W1 direction is the direction rotated from the V direction toward the -Z direction; the W2 direction is the direction rotated from the V direction toward the Z direction. In this embodiment, the W1 direction is defined as the direction rotated by β from the V direction toward the -Z direction, and the W2 direction is defined as the direction rotated by β from the V direction toward the Z direction. Note that β is an angle greater than 0° and smaller than 90°. The direction opposite the W1 direction is defined as the -W1 direction, and the direction opposite the W2 direction is defined as the -W2 direction. The W1 direction and the W2 direction are each perpendicular to the U direction.

[0022] The first detection circuit 20 is configured to detect a component of the target magnetic field parallel to the W1 direction and generate at least one first detection signal corresponding to this component, while the second detection circuit 30 is configured to detect a component of the target magnetic field parallel to the W2 direction and generate at least one second detection signal corresponding to this component.

[0023] 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 unit R21, a second resistor unit R22, a third resistor unit R23, and a fourth resistor unit R24. The multiple MR elements of the first detection circuit 20 constitute the first to fourth resistor units R21, R22, R23, and R24.

[0024] The first resistor R21 is provided between the power supply terminal V2 and the signal output terminal E21. The second resistor R22 is provided between the signal output terminal E21 and the ground terminal G2. The third resistor R23 is provided between the signal output terminal E22 and the ground terminal G2. The fourth resistor R24 ​​is provided between the power supply terminal V2 and the signal output terminal E22.

[0025] 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 unit R31, a second resistor unit R32, a third resistor unit R33, and a fourth resistor unit R34. The multiple MR elements of the second detection circuit 30 constitute the first to fourth resistor units R31, R32, R33, and R34.

[0026] The first resistor R31 is provided between the power supply terminal V3 and the signal output terminal E31. The second resistor R32 is provided between the signal output terminal E31 and the ground terminal G3. The third resistor R33 is provided between the signal output terminal E32 and the ground terminal G3. The fourth resistor R34 is provided between the power supply terminal V3 and the signal output terminal E32.

[0027] A voltage or current of a predetermined magnitude is applied to each of the power supply terminals V2 and V3, and each of the ground terminals G2 and G3 is connected to the ground.

[0028] 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. Because 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 represented by the symbol 50.

[0029] FIG. 7 is a side view of an MR element 50. The MR element 50 is a spin-valve type MR element. The MR element 50 includes a magnetization pinned layer 52 having a fixed magnetization direction, a free layer 54 having a magnetization direction that can change depending on the direction of a target magnetic field, and a gap layer 53 disposed between the magnetization pinned layer 52 and the free layer 54. The MR element 50 may be a TMR (tunnel magnetoresistance) element or a GMR (giant magnetoresistance) element. In a TMR element, the gap layer 53 is a tunnel barrier layer. In a GMR element, the gap layer 53 is a nonmagnetic conductive layer. In the MR element 50, the resistance value varies depending on the angle between the magnetization direction of the free layer 54 and the magnetization direction of the magnetization pinned layer 52. When this angle is 0°, the resistance value is minimum, and when the angle is 180°, the resistance value is maximum. In each MR element 50, the free layer 54 has shape anisotropy in which the direction of the easy axis of magnetization is perpendicular to the direction of magnetization of the magnetization fixed layer 52. Note that a magnet that applies a bias magnetic field to the free layer 54 can also be used as a means for setting the easy axis of magnetization in a predetermined direction in the free layer 54.

[0030] The MR element 50 further includes an antiferromagnetic layer 51. The antiferromagnetic layer 51, the magnetization pinned layer 52, the gap layer 53, and the free layer 54 are stacked in this order. The antiferromagnetic layer 51 is made of an antiferromagnetic material and generates exchange coupling with the magnetization pinned layer 52 to pin the magnetization direction of the magnetization pinned layer 52. The magnetization pinned layer 52 may be a so-called self-pinned type pinned layer (synthetic ferri-pinned layer, SFP layer). The self-pinned type pinned layer has a synthetic ferri-structure in which a ferromagnetic layer, a non-magnetic intermediate layer, and a ferromagnetic layer are stacked, and the two ferromagnetic layers are antiferromagnetically coupled. When the magnetization pinned layer 52 is a self-pinned type pinned layer, the antiferromagnetic layer 51 may be omitted.

[0031] The layers 51 to 54 in the MR element 50 may be arranged upside down relative to the arrangement shown in FIG.

[0032] 3 and 4, the solid arrows represent the magnetization direction of the magnetization fixed layer 52 of the MR element 50. The open arrows represent the magnetization direction of the free layer 54 of the MR element 50 when no target magnetic field is applied to the MR element 50.

[0033] In the example shown in FIG. 3, the magnetization direction of the magnetization fixed layer 52 in each of the first and third resistor units R21 and R23 is the W1 direction. The magnetization direction of the magnetization fixed layer 52 in each of the second and fourth resistor units R22 and R24 is the −W1 direction. The free layer 54 of each of the multiple first MR elements 50B has shape anisotropy in which the magnetization easy axis direction is parallel to the U direction. When no target magnetic field is applied to the first MR element 50B, the magnetization direction of the free layer 54 in each of the first and second resistor units R21 and R22 is the U direction. In the above case, the magnetization direction of the free layer 54 in each of the third and fourth resistor units R23 and R24 is the −U direction.

[0034] In the example shown in FIG. 4, the magnetization direction of the magnetization fixed layer 52 in each of the first and third resistor units R31 and R33 is the W2 direction. The magnetization direction of the magnetization fixed layer 52 in each of the second and fourth resistor units R32 and R34 is the −W2 direction. The free layer 54 of each of the second MR elements 50C has shape anisotropy such that the magnetization easy axis direction is parallel to the U direction. When no target magnetic field is applied to the second MR element 50C, the magnetization direction of the free layer 54 in each of the first and second resistor units R31 and R32 is the U direction. In the above case, the magnetization direction of the free layer 54 in each of the third and fourth resistor units R33 and R34 is the −U direction.

[0035] The magnetic sensor 1 includes a magnetic field generator configured to apply a magnetic field in a predetermined direction to the free layers 54 of each of the plurality of first MR elements 50B and the plurality of 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 layers 54 of each of the plurality of first MR elements 50B and the plurality of second MR elements 50C.

[0036] The direction of magnetization of the magnetization fixed layer 52 and the direction of the easy axis of magnetization of the free layer 54 may be slightly deviated from the above-mentioned directions in terms of the accuracy of manufacturing the MR element 50. The magnetization of the magnetization fixed layer 52 may be configured to include a magnetization component whose main component is in the above-mentioned direction. In this case, the direction of magnetization of the magnetization fixed layer 52 is the above-mentioned direction or approximately the above-mentioned direction.

[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 part of the cross section taken along 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, 306, 307, 308, 309, and 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 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 portion of a coil winding.

[0039] An insulating layer 302 is disposed on a substrate 301. A plurality of lower coil elements 81 are disposed on the insulating layer 302. An insulating layer 303 is disposed on the insulating layer 302 around the plurality of lower coil elements 81. Insulating layers 304, 305, and 306 are stacked in this order on the plurality of lower coil elements 81 and the insulating layer 303.

[0040] The plurality of lower electrodes 61B and the plurality of lower electrodes 61C are disposed on an insulating layer 306. An insulating layer 307 is disposed on the insulating layer 306 around the plurality of lower electrodes 61B and the plurality of lower electrodes 61C. The plurality of first MR elements 50B are disposed on the plurality of lower electrodes 61B. The plurality of second MR elements 50C are disposed on the plurality of lower electrodes 61C. An insulating layer 308 is disposed on the plurality of lower electrodes 61B, the plurality of lower electrodes 61C, and the insulating layer 307 around the plurality of first MR elements 50B and the plurality of second MR elements 50C. The plurality of upper electrodes 62B are disposed on the plurality of first MR elements 50B and the insulating layer 308. The plurality of upper electrodes 62C are disposed on the plurality of second MR elements 50C and the insulating layer 308. An insulating layer 309 is disposed on the insulating layer 308 around the plurality of upper electrodes 62B and the plurality of upper electrodes 62C.

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

[0042] The magnetic sensor 1 includes a support member that supports the plurality of first MR elements 50B and the 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, the support member is particularly formed of an insulating layer 305. Note that FIG. 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, which are components of the magnetic sensor 1.

[0043] The insulating layer 305 has a plurality of convex surfaces 305c each protruding in a direction (Z direction) away from the upper surface 301a of the substrate 301. 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 shifting the curved shape (arch shape) of the convex surface 305c shown in FIG. 6 along a direction parallel to the U direction. The plurality of convex surfaces 305c are also arranged at predetermined intervals in a direction parallel to the V direction.

[0044] Each of the multiple convex surfaces 305c has an upper end farthest from the upper surface 301a of the substrate 301. In this embodiment, the upper end of each of the multiple convex surfaces 305c extends in a direction parallel to the U direction. Here, attention is focused 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 closer to the V direction than the upper end of the convex surface 305c. The second inclined surface 305b is the surface of the convex surface 305c that is closer to the -V direction than the upper end of the convex surface 305c. In FIG. 5, the boundary between the first inclined surface 305a and the second inclined surface 305b is indicated by a dotted line.

[0045] The upper end of convex surface 305c may be the boundary between first inclined surface 305a and second inclined surface 305b. In this case, the dotted line shown in Figure 5 indicates the upper end of 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 with increasing distance from the upper surface 301a of the substrate 301.

[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. Insulating layer 305 has multiple first inclined surfaces 305a and multiple second inclined surfaces 305b.

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

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

[0050] Insulating layer 304 has a substantially constant thickness (dimension in the Z direction) and is formed along the lower surface of insulating layer 305. Insulating layer 306 has a substantially constant thickness (dimension in the Z direction) and is formed along the upper surface of insulating layer 305.

[0051] Particularly in this embodiment, insulating layer 305 includes a first layer 3051 disposed on insulating layer 304 and a second layer 3052 disposed on first layer 3051. Second layer 3052 includes a plurality of portions separated from each other. Insulating layer 306 is disposed on a portion of the upper surface of first layer 3051 where second layer 3052 is not disposed, and on the upper surface of second layer 3052. Each of the plurality of first inclined surfaces 305a and the plurality of second inclined surfaces 305b is formed across first layer 3051 and second layer 3052.

[0052] The plurality of lower electrodes 61B are disposed on the plurality of first inclined surfaces 305a. The plurality of lower electrodes 61C are disposed on the plurality of second inclined surfaces 305b. As described above, 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. Therefore, the upper surface of each of the plurality of lower electrodes 61B and each of the plurality of lower electrodes 61C are also inclined with respect to the XY plane. Therefore, it can be said that the plurality of first MR elements 50B and the plurality of second MR elements 50C are disposed on inclined surfaces inclined with respect to the XY plane. The insulating layer 305 is a member for supporting each of the plurality of first MR elements 50B and the plurality of second MR elements 50C so that they are inclined with respect to the XY plane.

[0053] In this embodiment, the first inclined surface 305a is a curved surface. Therefore, the first MR element 50B is curved along the curved surface (first inclined surface 305a). In this embodiment, for convenience, the magnetization direction of the magnetization fixed layer 52 of the first MR element 50B is defined as a linear direction as described above. The W1 direction and −W1 direction, which are the magnetization directions of the magnetization fixed layer 52 of the first MR element 50B, are also directions in which tangents that contact a portion of the first inclined surface 305a near the first MR element 50B extend.

[0054] Similarly, in this embodiment, the second inclined surface 305b is a curved surface. Therefore, the second MR element 50C is curved along the curved surface (second inclined surface 305b). In this embodiment, for convenience, the magnetization direction of the magnetization fixed layer 52 of the second MR element 50C is defined as a linear direction as described above. The W2 direction and −W2 direction, which are the magnetization directions of the magnetization fixed layer 52 of the second MR element 50C, are also directions in which tangents that contact a portion of the second inclined surface 305b near the second MR element 50C extend.

[0055] As shown in FIG. 5, the multiple first MR elements 50B are arranged in a row in the U direction and a row in the V direction. The multiple first MR elements 50B are arranged in a row on one first inclined surface 305a. Similarly, the multiple second MR elements 50C are arranged in a row in the U direction and a row in the V direction. The multiple second MR elements 50C are arranged in a row on one second inclined surface 305b. In this embodiment, the rows of the multiple first MR elements 50B and the rows of the multiple second MR elements 50C are arranged alternately in a direction parallel to the V direction.

[0056] Note that adjacent first MR elements 50B and adjacent second MR elements 50C may or may not be misaligned in a direction parallel to the U direction when viewed from the Z direction. Furthermore, two adjacent first MR elements 50B sandwiching one second MR element 50C may or may not be misaligned in a direction parallel to the U direction when viewed from the Z direction. Furthermore, two adjacent second MR elements 50C sandwiching one first MR element 50B may or may not be misaligned in a direction parallel to the U direction when viewed from the Z direction.

[0057] The plurality of first MR elements 50B are connected in series by a plurality of lower electrodes 61B and a plurality of upper electrodes 62B. Here, with reference to FIG. 7, a method of connecting the plurality of first MR elements 50B will be described in detail. In FIG. 7, reference numeral 61 denotes a lower electrode corresponding to any one of the MR elements 50, and reference numeral 62 denotes an upper electrode corresponding to any one of the MR elements 50. As shown in FIG. 7, each of the lower electrodes 61 has an elongated shape. A gap is formed between two of the lower electrodes 61 adjacent in the longitudinal direction of the lower electrode 61. On the upper surface of the lower electrode 61, an MR element 50 is disposed near each end in the longitudinal direction. Furthermore, each of the upper electrodes 62 has an elongated shape and is disposed on two of the lower electrodes 61 adjacent in the longitudinal direction of the lower electrode 61 to electrically connect the two adjacent MR elements 50 to each other.

[0058] Although not shown, one MR element 50 located at the end of a row of a plurality of MR elements 50 lined up in a line is connected to another MR element 50 located at the end of the row of a plurality of other MR elements 50 adjacent to it in a direction intersecting the longitudinal direction of the lower electrode 61. These two MR elements 50 are connected to each other by an electrode not shown. The electrode not shown may be an electrode connecting the bottom surfaces or top surfaces of the two MR elements 50 to each other.

[0059] 7 corresponds to the lower electrode 61B, and the upper electrode 62 corresponds to the upper electrode 62B. In this case, the longitudinal direction of the lower electrode 61 is parallel to the U direction.

[0060] Similarly, the plurality of second MR elements 50C are connected in series by the plurality of lower electrodes 61C and the plurality of upper electrodes 62C. The above description of the method for connecting the plurality of first MR elements 50B also applies to the method for connecting the plurality of second MR elements 50C. When the MR element 50 shown in FIG. 7 is the second MR element 50C, the lower electrode 61 shown in FIG. 7 corresponds to the lower electrode 61C, and the upper electrode 62 shown in FIG. 7 corresponds to the upper electrode 62C. In this case, the longitudinal direction of the lower electrode 61 is parallel to the U direction.

[0061] In this embodiment, the MR element 50 is described as a stacked film including an antiferromagnetic layer 51, a magnetization fixed layer 52, a gap layer 53, and a free layer 54. However, the MR element of this embodiment may also include this stacked film, a lower electrode 61, and an upper electrode 62. The stacked film includes multiple magnetic films. The lower electrode 61 is a non-magnetic metal layer disposed between the convex surface 305c and the multiple magnetic films. The MR element may also include multiple stacked films, multiple lower electrodes 61, and multiple upper electrodes 62.

[0062] Each of the multiple upper coil elements 82 extends in a direction parallel to the Y direction. The multiple upper coil elements 82 are also arranged side by side in the X direction. In particular, in this embodiment, 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.

[0063] Each of the multiple lower coil elements 81 extends in a direction parallel to the Y direction. The multiple lower coil elements 81 are also arranged so as to line up 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 example shown in FIGS. 5 and 6, the dimension in the X direction of each of the multiple lower coil elements 81 is smaller than the dimension in the X direction of each of the multiple upper coil elements 82. The distance between two lower coil elements 81 adjacent in the X direction is also smaller than the distance between two upper coil elements 82 adjacent in the X direction.

[0064] 5 and 6 , the plurality of lower coil elements 81 and the plurality of 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 54 of each of the plurality of first MR elements 50B and the plurality of second MR elements 50C. The coil 80 may be configured to apply a magnetic field in the X direction to the free layers 54 of the first and second resistor units R21 and R22 of the first detection circuit 20 and the first and second resistor units R31 and R32 of the second detection circuit 30, and to apply a magnetic field in the −X direction to the free layers 54 of the third and fourth resistor units R23 and R24 of the first detection circuit 20 and the third and fourth resistor units R33 and R34 of the second detection circuit 30. The coil 80 may be controlled by the processor 40.

[0065] Next, the first and second detection signals will be described. First, the first detection signal will be described with reference to FIG. 3. When the intensity of the component of the target magnetic field parallel to the W1 direction changes, the resistance values ​​of the resistors R21 to R24 of the first detection circuit 20 change such that the resistance values ​​of the resistors R21 and R23 increase while the resistance values ​​of the resistors R22 and R24 decrease, or the resistance values ​​of the resistors R21 and R23 decrease while the resistance values ​​of the resistors R22 and R24 increase. This causes a change in the potential of each of the signal output terminals E21 and E22. 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 generate a signal corresponding to the potential of the signal output terminal E22 as the first detection signal S22.

[0066] Next, the second detection signal will be described with reference to FIG. 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 the resistors R31 and R33 increase while the resistance values ​​of the resistors R32 and R34 decrease, or the resistance values ​​of the resistors R31 and R33 decrease while the resistance values ​​of the resistors R32 and R34 increase. This causes a change in the potential of each of the signal output terminals E31 and E32. 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.

[0067] 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 a detection value corresponding to a component of the target magnetic field in a direction parallel to the V direction. The second detection value is a detection value corresponding to a component of the target magnetic field in a direction parallel to the Z direction. Hereinafter, the first detection value will be represented by the symbol Sv, and the second detection value will be represented by the symbol Sz.

[0068] The processor 40 generates the first and second detection values ​​Sv and Sz, for example, as follows: The processor 40 first generates a value S1 by an operation that includes determining the difference S21-S22 between the first detection signal S21 and the first detection signal S22, and also generates a value S2 by an operation that includes determining the difference S31-S32 between the second detection signal S31 and the second detection signal S32. Next, the processor 40 calculates the values ​​S3 and S4 using the following equations (1) and (2).

[0069] S3 = (S2 + S1) / (2cosα) … (1) S4 = (S2 - S1) / (2 sin α) ... (2)

[0070] The first detection value Sv may be the value S3 itself, or may be the value S3 to which predetermined corrections such as gain adjustment and offset adjustment have been made. Similarly, the second detection value Sz may be the value S4 itself, or may be the value S4 to which predetermined corrections such as gain adjustment and offset adjustment have been made.

[0071] Next, a method for manufacturing the magnetic sensor 1 according to this embodiment will be described with reference to Fig. 8 to Fig. 11. Fig. 8 to Fig. 11 show a laminate in the manufacturing process of the magnetic sensor 1. In the method for manufacturing the magnetic sensor 1, first, as shown in Fig. 8, an insulating layer 302 is formed on a substrate 301. Next, a plurality of lower coil elements 81, a connecting layer 83 made of a conductive material, and an insulating layer 303 are formed on the insulating layer 302. Next, an insulating layer 304 is formed on the plurality of lower coil elements 81, the connecting layer 83, and the insulating layer 303.

[0072] 9 shows the next step. In this step, first, the insulating layer 304 is selectively etched to form an opening in the insulating layer 304 that exposes the upper surface of the connection layer 83. Next, a metal film 84 made of a conductive material is formed on the upper surface of the connection layer 83. Next, a connection layer 85 made of a conductive material is formed on the metal film 84. Next, a first layer 3051 of the insulating layer 305 is formed around the connection layer 85.

[0073] 10 shows the next step. In this step, first, a metal film 86 made of a conductive material is formed on the upper surface of the connection layer 85. Next, a second layer 3052 of the insulating layer 305 is formed on the metal film 86 and the first layer 3051 of the insulating layer 305.

[0074] FIG. 11 illustrates the next step. In this step, the first layer 3051 and the second layer 3052 are etched to form multiple convex surfaces 305c on the insulating layer 305. The multiple convex surfaces 305c are formed, for example, by forming multiple etching masks on the second layer 3052 and then etching the first layer 3051, the second layer 3052, and the multiple etching masks so that the multiple etching masks are removed. The multiple etching masks have shapes corresponding to the multiple convex surfaces 305c. Portions of the first layer 3051 not covered by the multiple etching masks become flat surfaces 305d. During this etching, the metal film 86 functions as an etching stopper to protect the connection layer 85.

[0075] The connection layer 85 is a structure embedded in the first layer 3051. The connection layer 85 has an end face, i.e., an upper face, that is farthest from the upper face 301a of the substrate 301. The end face (upper face) of the connection layer 85 is located at substantially the same position as the interface between the first layer 3051 and the second layer 3052 in a direction perpendicular to the upper face 301a of the substrate 301, i.e., in a direction parallel to the Z direction.

[0076] 6, the steps after etching the first layer 3051 and the second layer 3052 will be described. First, the insulating layer 306 is formed on the first layer 3051 and the second layer 3052. Next, on the insulating layer 306, a plurality of lower electrodes 61B, a plurality of lower electrodes 61C, a plurality of first MR elements 50B, a plurality of second MR elements 50C, a plurality of upper electrodes 62B, a plurality of upper electrodes 62C, and insulating layers 307 to 309 are formed.

[0077] Next, the insulating layer 310 is formed on the plurality of upper electrodes 62B, the plurality of upper electrodes 62C, and the insulating layer 309. Next, the plurality of upper coil elements 82 are formed on the insulating layer 310. In this way, the magnetic sensor 1 is completed.

[0078] The connection layers 83, 85 may be used as connection portions that connect the plurality of lower coil elements 81 and the plurality of upper coil elements 82. In this case, for example, after forming the insulating layer 310 and before forming the plurality of upper coil elements 82, the insulating layers 306-310 may be selectively etched to form openings that expose the metal film 86, and a connection layer (not shown) made of a conductive material may be formed in this opening. After the connection layer (not shown) is formed, the plurality of upper coil elements 82 are formed so as to be connected to the connection layer (not shown).

[0079] Alternatively, the metal film 86 may be used as any electrode pad (e.g., an electrode pad of the coil 80). In this case, for example, after etching the first layer 3051 and the second layer 3052 and before forming the insulating layer 306, a photoresist layer covering the metal film 86 may be formed. The photoresist layer is removed, for example, after forming the upper coil element 82.

[0080] Next, structural features of the magnetic sensor 1 according to this embodiment will be described. The magnetic sensor 1 includes a substrate 301 having an upper surface 301a, a support member disposed on the substrate 301, a first MR element 50B, and a second MR element 50C. In this embodiment, the insulating layer 305 particularly corresponds to the support member. A plurality of lower coil elements 81 and insulating layers 302 to 304 are interposed between the substrate 301 and the insulating layer 305. The insulating layer 305 has a first inclined surface 305a and a second inclined surface 305b.

[0081] Each of the first and second MR elements 50B and 50C includes at least two magnetic films: a magnetization fixed layer 52 and a free layer 54. The two magnetic films of the first MR element 50B constitute a part (main part) of the first MR element 50B. The two magnetic films of the second MR element 50C constitute a part (main part) of the second MR element 50C. Hereinafter, these two magnetic films will be referred to as functional layers. The functional layer of the first MR element 50B is disposed on the first inclined surface 305a. The functional layer of the second MR element 50C is disposed on the second inclined surface 305b. The insulating layer 305 includes a first layer 3051 and a second layer 3052 disposed on the first layer 3051. The first layer 3051 and the second layer 3052 are each formed of an insulating material such as SiO2.

[0082] The features of the first inclined surface 305a, the second inclined surface 305b, the first layer 3051, and the second layer 3052 will be described in detail below with reference to Fig. 12. Fig. 12 is an explanatory diagram for explaining the shape of the support member, i.e., the insulating layer 305.

[0083] The first inclined surface 305a and the second inclined surface 305b are each formed across the first layer 3051 and the second layer 3052. The first inclined surface 305a and the second inclined surface 305b face in different directions. In one convex surface 305c, the first inclined surface 305a and the second inclined surface 305b may be symmetrical with respect to a virtual UZ plane perpendicular to the upper surface 301a of the substrate 301.

[0084] From the viewpoint of reducing the height of the magnetic sensor 1, it is preferable that the dimensions of each of the first inclined surface 305a and the second inclined surface 305b in a direction perpendicular to the upper surface 301a of the substrate 301, i.e., in a direction parallel to the Z direction, be in the range of 1.4 μm or more and 3.0 μm or less.

[0085] The first inclined surface 305a has a first edge 305a1 closest to the top surface 301a of the substrate 301 and a second edge 305a2 farthest from the top surface 301a of the substrate 301. The first edge 305a1 is located on the first layer 3051. The second edge 305a2 is located on the second layer 3052.

[0086] The second inclined surface 305b has a first edge 305b1 closest to the upper surface 301a of the substrate 301 and a second edge 305b2 farthest from the upper surface 301a of the substrate 301. The first edge 305b1 is located on the first layer 3051. The second edge 305b2 is located on the second layer 3052. In the example shown in FIG. 12, the second edge 305b2 of the second inclined surface 305b coincides with the second edge 305a2 of the first inclined surface 305a.

[0087] The first layer 3051 has a bottom end 3051a closest to the top surface 301a of the substrate 301 and a top end 3051b farthest from the top surface 301a of the substrate 301. The second layer 3052 has a bottom end 3052a closest to the top surface 301a of the substrate 301 and a top end 3052b farthest from the top surface 301a of the substrate 301. The distance from the interface between the first layer 3051 and the second layer 3052 to the bottom end 3051a of the first layer 3051 is shorter than the distance from the interface between the first layer 3051 and the second layer 3052 to the top end 3052b of the second layer 3052.

[0088] A first edge 305a1 of the first inclined surface 305a is disposed between the lower end 3051a and the upper end 3051b of the first layer 3051 in a direction perpendicular to the upper surface 301a of the substrate 301, i.e., in a direction parallel to the Z direction. A first edge 305b1 of the second inclined surface 305b is disposed between the lower end 3051a and the upper end 3051b of the first layer 3051 in a direction parallel to the Z direction.

[0089] The functional layer of the first MR element 50B is disposed along the surface of the second layer 3052, but is not disposed along the surface of the first layer 3051. In addition, the functional layer of the second MR element 50C is disposed along the surface of the second layer 3052, but is not disposed along the surface of the first layer 3051.

[0090] In this embodiment, first inclined surface 305a is a generally smooth curved surface. There is no step at the boundary between first layer 3051 and second layer 3052 on first inclined surface 305a. Similarly, in this embodiment, second inclined surface 305b is a generally smooth curved surface. There is no step at the boundary between first layer 3051 and second layer 3052 on second inclined surface 305b.

[0091] Next, the characteristics of the support member, i.e., the convex surface 305c of the insulating layer 305, will be described with reference to FIG. 13. FIG. 13 is an explanatory diagram for explaining the shape of the convex surface 305c. The insulating layer 305 has the convex surface 305c. The convex surface 305c protrudes in a direction away from the upper surface 301a of the substrate 301. At least a portion of the convex surface 305c is inclined with respect to the upper surface 301a of the substrate 301. In this embodiment in particular, the convex surface 305c includes a first inclined surface 305a and a second inclined surface 305b.

[0092] The convex surface 305c has an upper end E1 that is farthest from the upper surface 301a of the substrate 301. The upper end E1 may coincide with the second edge 305a2 of the first inclined surface 305a and the second edge 305b2 of the second inclined surface 305b shown in FIG.

[0093] The dimension of convex surface 305c in a direction perpendicular to upper surface 301a of substrate 301, i.e., a direction parallel to the Z direction, is the same as the dimension of each of first and second inclined surfaces 305a, 305b in a direction parallel to the Z direction. That is, the dimension of convex surface 305c in a direction parallel to the Z direction is preferably in the range of 1.4 μm to 3.0 μm. Furthermore, the dimension of convex surface 305c in a direction parallel to the V direction is preferably, for example, in the range of 3 μm to 16 μm.

[0094] The convex surface 305c includes a first curved surface portion 305c1 including an upper end portion E1, a second curved surface portion 305c2, and a third curved surface portion 305c3. The second curved surface portion 305c2 is continuous with the first curved surface portion 305c1 at a position on the V-direction side of the first curved surface portion 305c1 and is located between the first curved surface portion 305c1 and the upper surface 301a of the substrate 301 in the direction perpendicular to the upper surface 301a of the substrate 301. The third curved surface portion 305c3 is continuous with the first curved surface portion 305c1 at a position opposite the second curved surface portion 305c2, i.e., on the −V-direction side of the first curved surface portion 305c1, and is located between the first curved surface portion 305c1 and the upper surface 301a of the substrate 301 in the direction perpendicular to the upper surface 301a of the substrate 301. Additionally, the second curved surface portion 305c2 and the third curved surface portion 305c3 are each continuous with the flat surface 305d.

[0095] First curved surface portion 305c1 is a curved surface that is convex in a direction away from top surface 301a of substrate 301. Second curved surface portion 305c2 and third curved surface portion 305c3 are each a curved surface that is convex in a direction approaching top surface 301a of substrate 301.

[0096] Here, a cross section perpendicular to the upper surface 301a of the substrate 301 and parallel to the VZ plane is referred to as a reference cross section. The first curved surface portion 305c1 can be approximated by a circular arc in the reference cross section. In FIG. 13, the radius of curvature of the first curved surface portion 305c1 in the reference cross section, i.e., the radius of curvature of the circular arc approximating the entire first curved surface portion 305c1, is indicated by the symbol R1. The radius of curvature R1 is preferably 4.25 μm or more and 5.45 μm or less.

[0097] Similarly, second curved surface portion 305c2 and third curved surface portion 305c3 can each be approximated by a circular arc in the reference cross section. In Fig. 13, the radius of curvature of second curved surface portion 305c2 in the reference cross section, i.e., the radius of curvature of the circular arc approximating second curved surface portion 305c2, is indicated by symbol R2, and the radius of curvature of third curved surface portion 305c3 in the reference cross section, i.e., the radius of curvature of the circular arc approximating third curved surface portion 305c3, is indicated by symbol R3. Each of curvature radii R2 and R3 is preferably smaller than curvature radius R1 and is 0.3 µm or greater.

[0098] Here, the shape of the convex surface 305c in the reference cross section is regarded as function Z, whose independent variable is the position on an imaginary line parallel to both the reference cross section and the upper surface 301a of the substrate 301. The imaginary line is parallel to the V direction. Hereinafter, the imaginary line will be referred to as the V axis, and the position on the V axis will be represented by the symbol v. The function Z is a function whose independent variable is v. The value of the function Z corresponds to the position of the convex surface 305c in a direction parallel to the Z direction. Figure 14 shows a graph of the function Z. In Figure 14, the horizontal axis represents the position on the V axis, and the vertical axis represents the value of the function Z. Figure 14 essentially shows the shape of the convex surface 305c in the reference cross section.

[0099] 14, the position on the V axis corresponding to the upper end E1 of the convex surface 305c is set as the origin (0 μm) on the horizontal axis, and positions on the V side of the origin are represented by positive values, and positions on the −V side of the origin are represented by negative values. Also, in FIG. 14, the position of the flat surface 305d in a direction parallel to the Z direction is set as 0 μm.

[0100] FIG. 15 shows a graph of the first derivative Z' (dZ / dv) obtained by differentiating the function Z once with the variable v. In FIG. 15, the horizontal axis indicates the position on the V axis, and the vertical axis indicates the value of the first derivative Z'. Also, FIG. 16 shows the second derivative Z'' (d 2 Z / dv 2 15. In FIG. 15, the horizontal axis represents the position on the V axis, and the vertical axis represents the value of the second derivative Z″.

[0101] The two positions where the second derivative Z" is 0 represent the position on the V axis corresponding to the boundary between the first curved surface portion 305c1 and the second curved surface portion 305c2 and the position on the V axis corresponding to the boundary between the first curved surface portion 305c1 and the third curved surface portion 305c3. Therefore, by referring to Figure 16, the positions of each of the first to third curved surface portions 305c1 to 305c3 can be determined. Figures 14 to 16 show the approximate ranges of each of the first to third curved surface portions 305c1 to 305c3.

[0102] As shown in Figure 16, at the position on the V axis corresponding to the first curved surface portion 305c1, the value of the second derivative Z'' is less than or equal to 0. Furthermore, at the position on the V axis corresponding to the second curved surface portion 305c2 and the position on the V axis corresponding to the second curved surface portion 305c3, the value of the second derivative Z'' is positive.

[0103] Here, as shown in FIG. 16, the first curved surface portion 305c1 is divided into a first portion c11, a second portion c12, and a third portion c13. The first portion c11 is a portion including the upper end portion E1 of the convex surface 305c. The second portion c12 is a portion that is located away from the upper end portion E1 of the convex surface 305c and continues to the first portion c11 on the V-direction side of the first portion c11. The third portion c13 is a portion that is located away from the upper end portion E1 of the convex surface 305c and continues to the first portion c11 on the −V-direction side of the first portion c11. The second portion c12 is located below (on the −Z-direction side of) the first MR element 50B. The third portion c13 is located below (on the −Z-direction side of) the second MR element 50C. The first and second MR elements 50B and 50C are not present above (on the Z-direction side of) the first portion c11. FIG. 16 shows the approximate range of each of the first to third portions c11 to c13.

[0104] The average value of the absolute values ​​of the second derivative Z" of the function Z corresponding to the first portion c11 is smaller than the average value of the absolute values ​​of the second derivative Z" of the function Z corresponding to the second portion c12. Similarly, the average value of the absolute values ​​of the second derivative Z" of the function Z corresponding to the first portion c11 is smaller than the average value of the absolute values ​​of the second derivative Z" of the function Z corresponding to the third portion c13.

[0105] Furthermore, in this embodiment, the value of the first derivative Z' of the function Z corresponding to the first curved surface portion 305c1 decreases or increases as one approaches from one end of the first curved surface portion 305c1 in a direction parallel to the V direction to the other end of the first curved surface portion 305c1 in a direction parallel to the V direction. That is, the value of the first derivative Z' decreases as one approaches from the end of the first curved surface portion 305c1 on the -V direction side to the end of the first curved surface portion 305c1 on the V direction side. Alternatively, the value of the first derivative Z' increases as one approaches from the end of the first curved surface portion 305c1 on the V direction side to the end of the first curved surface portion 305c1 on the -V direction side.

[0106] Next, the operation and effects of the magnetic sensor 1 according to this embodiment will be described. In this embodiment, the support member, i.e., the insulating layer 305, includes a first layer 3051 and a second layer 3052, and has first and second inclined surfaces 305a and 305b formed across the first layer 3051 and the second layer 3052, respectively. Consider embedding a structure made of a metal material in a comparative support member consisting of only a single insulating layer. When the inclined surfaces are formed on the support member of the comparative support member by etching, the structure significantly protrudes from the surface formed by etching due to differences in etching rate. In this case, for example, the shadow of the structure can cause problems, such as making it difficult to pattern some of the electrodes and MR elements formed on the inclined surfaces.

[0107] In contrast to this, in the present embodiment, for example, first inclined surface 305a and second inclined surface 305b can be formed on insulating layer 305 in a state where a structure is embedded in first layer 3051 and no structure is embedded in second layer 3052. As a result, according to the present embodiment, the amount of protrusion of the structure can be reduced compared to the support member of the comparative example.

[0108] The insulating material of the first layer 3051 and the insulating material of the second layer 3052 may be the same or different from each other. The film formation conditions of the first layer 3051 and the second layer 3052 may be the same or different from each other. For example, by making at least one of the insulating material and the film formation conditions different between the first layer 3051 and the second layer 3052, it becomes possible to make the shape of a portion of the convex surface 305c formed on the first layer 3051 and the shape of another portion of the convex surface 305c formed on the second layer 3052 different from each other.

[0109] In this embodiment, convex surface 305c includes first to third curved surface portions 305c1 to 305c3, each having the aforementioned shape. If second and third curved surface portions 305c2 and 305c3 were not present, flat surface 305d and first curved surface portion 305c1 would be discontinuous at the boundary between flat surface 305d and first curved surface portion 305c1. Therefore, the surface of insulating layer 305 would not be smooth. In contrast, in this embodiment, convex surface 305c includes second and third curved surface portions 305c2 and 305c3, thereby smoothing the surface of insulating layer 305. This embodiment thus prevents cracks from occurring in insulating layer 305 near the boundary between convex surface 305c and flat surface 305d.

[0110] As described above, the radius of curvature R1 of the first curved surface portion 305c1 of the convex surface 305c is different from the radius of curvature R2 of the second curved surface portion 305c2 of the convex surface 305c and the radius of curvature R3 of the third curved surface portion 305c3 of the convex surface 305c. At least a portion of the first curved surface portion 305c1 is formed in the second layer 3052. At least a portion of each of the second and third curved surface portions 305c2 and 305c3 is formed in the first layer 3051. According to this embodiment, for example, by differentiating at least one of the insulating material and the film-forming conditions between the first layer 3051 and the second layer 3052, it is possible to separately adjust the etching rates of the first layer 3051 and the second layer 3052. As a result, according to this embodiment, it is easy to adjust the radii of curvature R2 and R3 within preferred ranges while maintaining the radius of curvature R1 within a preferred range.

[0111] In particular, in this embodiment, by setting the radii of curvature R2 and R3 within the aforementioned ranges, it is possible to suppress the occurrence of cracks in the insulating layer 305 near the boundary between the convex surface 305c and the flat surface 305d, compared to when the second and third curved surface portions 305c2 and 305c3 do not exist or when the radii of curvature are so small that the boundary between the convex surface 305c and the flat surface 305d can be considered discontinuous.

[0112] As can be seen from FIG. 16 , in this embodiment, the value of the second derivative Z″ of the function Z corresponding to the first curved surface portion 305c1 is not constant. Therefore, strictly speaking, the radius of curvature R1 changes depending on the position on the V axis. Particularly in this embodiment, the average value of the absolute values ​​of the second derivative Z″ of the function Z corresponding to the first portion c11 of the first curved surface portion 305c1 is smaller than the average value of the absolute values ​​of the second derivative Z″ of the function Z corresponding to the second portion c12 of the first curved surface portion 305c1 and the average value of the absolute values ​​of the second derivative Z″ of the function Z corresponding to the third portion c13 of the first curved surface portion 305c1. Therefore, in this embodiment, the radius of curvature R1 in the first portion c11 is larger than the radius of curvature R1 in the second portion c12 and the radius of curvature R1 in the third portion c13. As a result, according to this embodiment, the dimension of the convex surface 305c in a direction parallel to the Z direction can be reduced, i.e., the height of the convex surface 305c can be lowered, compared to when the radius of curvature R1 is constant regardless of the position on the V axis.

[0113] In addition, in this embodiment, the dimension of the convex surface 305c in the direction parallel to the Z direction is preferably within a range of 1.4 μm to 3.0 μm. According to an exemplary embodiment, by setting the dimension of the convex surface 305c to 1.4 μm or more, the inclination of each of the first inclined surface 305a and the second inclined surface 305b can be increased, thereby increasing the sensitivity of the magnetic sensor 1 to the component of the target magnetic field in a direction parallel to the Z direction. As a result, according to the exemplary embodiment, the second detection value Sz can be generated with high accuracy. Furthermore, according to the exemplary embodiment, by setting the dimension of the convex surface 305c to 3.0 μm or less, a photoresist mask made of a photoresist layer can be accurately formed on the first inclined surface 305a and the second inclined surface 305b during the manufacturing process of the magnetic sensor 1.

[0114] The present invention is not limited to the above-described embodiment and may be modified in various ways. For example, the magnetic detection element is not limited to an MR element, but may be an element for detecting a magnetic field other than an MR element, such as a Hall element.

[0115] Furthermore, the support member of the present invention, i.e., insulating layer 305, may be composed of only one insulating layer. The description of insulating layer 305, except for the description of first layer 3051 and second layer 3052, also applies to this single insulating layer.

[0116] Furthermore, the support member of the present invention may be formed by insulating layer 305 and insulating layer 306. In this case, the support member has multiple convex surfaces and a flat surface. The multiple convex surfaces and flat surface are formed by the upper surface of insulating layer 306. The upper surface of insulating layer 306 has a shape similar or nearly similar to that of the upper surface of insulating layer 305. Therefore, the multiple convex surfaces formed by the upper surface of insulating layer 306 have a shape similar or nearly similar to that of multiple convex surfaces 305c of insulating layer 305. The descriptions regarding the shape and arrangement of multiple convex surfaces 305c also apply to the multiple convex surfaces formed by the upper surface of insulating layer 306, except for the descriptions regarding first layer 3051 and second layer 3052. Specifically, the descriptions regarding the dimensions of convex surface 305c, the descriptions regarding radii of curvature R1 to R3, and the descriptions regarding function Z, first derivative Z', and second derivative Z'' also apply to the multiple convex surfaces formed by the upper surface of insulating layer 306.

[0117] The magnetic sensor 1 may further include a third detection circuit configured to detect a component of the target magnetic field in one direction parallel to the XY plane and 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 the at least one third detection signal. The third detection circuit may be integrated with the first and second detection circuits 20 and 30, or may be included on a chip separate from the first and second detection circuits 20 and 30.

[0118] Furthermore, the sensor element of the present invention is not limited to a magnetic detection element, but may be a sensor element configured such that its physical properties change in response to a predetermined physical quantity. The predetermined physical quantity is not limited to a magnetic field, but may include any quantity of the state of a physical phenomenon that can be detected by the sensor element, such as an electric field, temperature, displacement, or force. The above description of the embodiment also applies to sensors other than magnetic sensors that include sensor elements other than magnetic detection elements, provided that the magnetic detection element is replaced with a sensor element. In this case, the functional layer may be a portion that constitutes at least a part of the sensor element and whose physical properties change in response to the predetermined physical quantity. Furthermore, in this case, the metal layer may be any wiring layer.

[0119] As described above, the sensor of the present invention is a sensor configured to detect a predetermined physical quantity. The sensor of the present invention includes a substrate having an upper surface, a support member disposed on the substrate, and a sensor element configured to change physical properties in response to the predetermined physical quantity. The support member has a convex surface that protrudes away from the upper surface of the substrate and at least a portion of which is inclined relative to the upper surface of the substrate. The convex surface has an upper end furthest from the upper surface of the substrate. The sensor element includes a functional layer that constitutes at least a portion of the sensor element. The functional layer is disposed on the convex surface. The convex surface includes a first curved surface portion including the upper end, and a second curved surface portion that is continuous with the first curved surface portion and is located between the first curved surface portion and the upper surface of the substrate in a direction perpendicular to the upper surface of the substrate. The second curved surface portion is a curved surface that is convex in a direction approaching the upper surface of the substrate.

[0120] In the sensor of the present invention, the radius of curvature of the second curved surface portion in a cross section perpendicular to the upper surface of the substrate may be smaller than the radius of curvature of the first curved surface portion in a cross section perpendicular to the upper surface of the substrate and may be 0.3 μm or more.

[0121] In the sensor of the present invention, the first curved surface portion may be a curved surface that is convex in a direction away from the upper surface of the substrate, and the radius of curvature of the first curved surface portion in a cross section perpendicular to the upper surface of the substrate may be 4.25 μm or more and 5.45 μm or less.

[0122] In the sensor of the present invention, the convex surface may further include a third curved surface portion that is continuous with the first curved surface portion on the side opposite to the second curved surface portion and is located between the first curved surface portion and the upper surface of the substrate in a direction perpendicular to the upper surface of the substrate. The third curved surface portion may be a curved surface that is convex toward the upper surface of the substrate. Furthermore, when the first curved surface portion is a curved surface that is convex away from the upper surface of the substrate, the radius of curvature of the third curved surface portion in a cross section perpendicular to the upper surface of the substrate may be smaller than the radius of curvature of the first curved surface portion in a cross section perpendicular to the upper surface of the substrate and may be 0.3 μm or greater.

[0123] In the sensor of the present invention, the support member may further have a flat surface that is continuous with the convex surface and is parallel to the upper surface of the substrate.

[0124] In the sensor of the present invention, the dimension of the convex surface in a direction perpendicular to the upper surface of the substrate may be 1.4 μm or more and 3.0 μm or less.

[0125] In the sensor of the present invention, the predetermined physical quantity may be at least one of the direction and strength of a target magnetic field. The sensor element may be a magnetic detection element configured to detect changes in at least one of the direction and strength of a target magnetic field. The magnetic detection element may be a magnetoresistive element. The functional layer may include a plurality of magnetic films. The magnetoresistive element may further include a non-magnetic metal layer disposed between the convex surface and the plurality of magnetic films. [Explanation of symbols]

[0126] 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...antiferromagnetic layer, 52...magnetization fixed layer, 53...gap layer, 54...free layer, 61, 61B, 61C...lower electrode, 62, 62B, 62C...upper electrode, 80...coil, 81...lower coil element, 82...upper Internal coil element, 100...magnetic sensor device, 301...substrate, 301a...upper surface, 302-310...insulating layer, 305a...first inclined surface, 305b...second inclined surface, 305c...convex surface, 305c1...first curved surface portion, 305c2...second curved surface portion, 305c3...third curved surface portion, 305d...flat surface, c11...first portion, c12...second portion, c13...third portion.

Claims

1. 1. A sensor configured to detect a predetermined physical quantity, comprising: a substrate having a top surface; a support member disposed on the substrate; a sensor element configured so that a physical property changes in response to the predetermined physical quantity, the support member has a convex surface that protrudes in a direction away from the upper surface of the substrate and at least a portion of which is inclined with respect to the upper surface of the substrate; the convex surface has an upper end furthest from the upper surface of the substrate; the sensor element includes a functional layer that constitutes at least a part of the sensor element; the functional layer is disposed on the convex surface; the convex surface includes a first curved surface portion including the upper end portion, and a second curved surface portion that is continuous with the first curved surface portion and is located between the first curved surface portion and the upper surface of the substrate in a direction perpendicular to the upper surface of the substrate, the first curved surface portion is a curved surface that is convex in a direction away from the top surface of the substrate, the second curved surface portion is a curved surface that is convex in a direction approaching the upper surface of the substrate, a radius of curvature of the second curved surface portion in a cross section perpendicular to the top surface of the substrate is smaller than a radius of curvature of the first curved surface portion in a cross section perpendicular to the top surface of the substrate and is 0.3 μm or more; The sensor, wherein the radius of curvature of the first curved surface portion in a cross section perpendicular to the upper surface of the substrate is 4.25 μm or more and 5.45 μm or less.

2. the convex surface further includes a third curved surface portion that is continuous with the first curved surface portion on the side opposite to the second curved surface portion and is located between the first curved surface portion and the upper surface of the substrate in a direction perpendicular to the upper surface of the substrate, the third curved surface portion is a curved surface that is convex in a direction approaching the upper surface of the substrate, 2. The sensor according to claim 1, wherein the radius of curvature of the third curved surface portion in a cross section perpendicular to the top surface of the substrate is smaller than the radius of curvature of the first curved surface portion in a cross section perpendicular to the top surface of the substrate and is 0.3 μm or more.

3. 2. The sensor according to claim 1, wherein the support member further has a flat surface that is continuous with the convex surface and is parallel to the upper surface of the substrate.

4. 2. The sensor according to claim 1, wherein the dimension of the convex surface in a direction perpendicular to the upper surface of the substrate is 1.4 μm or more and 3.0 μm or less.

5. the predetermined physical quantity is at least one of the direction and the intensity of the target magnetic field; 5. The sensor according to claim 1, wherein the sensor element is a magnetic detection element configured to detect a change in at least one of the direction and the intensity of the target magnetic field.

6. the magnetic detection element is a magnetoresistive element, 6. The sensor according to claim 5, wherein the functional layer includes a plurality of magnetic films.

7. 7. The sensor according to claim 6, wherein the magnetoresistive element further includes a non-magnetic metal layer disposed between the convex surface and the plurality of magnetic films.

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