JP2016058609A - Magnetic sensor and method of manufacturing magnetic sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a magnetic sensor that can achieve compaction thereof.SOLUTION: A method of manufacturing a magnetic sensor has a deposition step for depositing a pinned layer constituting a part of magnetoresistance effect elements X1A, X1B, ..., Y1A, Y1B, ... on an inclined plane inclining for the flat surface of a substrate 1W, and a magnetization step for applying an external magnetic field having a component perpendicular to the flat surface of a substrate 1W, and fixing the azimuth of magnetization of a pinned layer based on the perpendicular component.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a magnetic sensor using a magnetoresistive effect element and a method for manufacturing the magnetic sensor.

  Conventionally, giant magnetoresistive elements (GMR (Giant Magneto Resistance) elements) are known as elements used in magnetic sensors. A so-called spin-valve magnetoresistive element includes a pinned layer whose magnetization is fixed (pinned) in a predetermined direction and a free layer whose magnetization direction changes according to an external magnetic field, and the magnetization direction of the pinned layer And the resistance value changes according to the relative relationship between the magnetization direction of the free layer. By electrically detecting the change in the resistance value, the strength of the external magnetic field (magnetic field) can be grasped.

  Further, as a method of manufacturing a magnetic sensor using such a magnetoresistive effect element, a regularized heat treatment is performed in which a heat treatment is performed while a magnet array in which permanent magnets are arranged in a matrix on a predetermined surface is superimposed on a semiconductor wafer (substrate). The process is known (for example, Patent Document 1). By superimposing a magnet array on a semiconductor wafer, an external magnetic field having regularity in a horizontal direction with respect to the flat surface can be applied to each of the matrix-like sections (that is, magnetic sensors) on the flat surface of the semiconductor wafer. it can. Accordingly, the magnetization direction of the pinned layer can be fixed to a desired direction based on the horizontal direction component of the external magnetic field for each of the plurality of magnetoresistive elements constituting the magnetic sensor.

JP 2007-212275 A

  As described above, the magnetic sensor is formed in a matrix on the flat surface of the semiconductor wafer. In the magnet array, permanent magnets are arranged so as to correspond to each section (magnetic sensor) of the matrix. Here, when downsizing the magnetic sensor, it is necessary to reduce the lattice arrangement of the permanent magnets in the magnet array in accordance with the reduction of the section formed on the flat surface of the semiconductor wafer.

  However, when the pitch (interval) of the permanent magnets arranged in a matrix in the magnet array is narrowed, the magnetic field generated between the permanent magnets having different polarities is curved and travels more than the component traveling straight between the permanent magnets. Becomes dominant. Therefore, it becomes difficult to apply the horizontal component of the external magnetic field to the flat surface of the semiconductor wafer as desired. Also, the smaller the compartment, the more difficult it is to manufacture the magnet array. Therefore, the ordering heat treatment process becomes a bottleneck, and it is difficult to reduce the size of the magnetic sensor.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a magnetic sensor and a method of manufacturing the magnetic sensor that can realize downsizing of the magnetic sensor.

One embodiment of the present invention is a film formation step of forming a multilayer film including a magnetoresistive element and including at least a pinned layer on an inclined surface provided on a flat surface of a substrate, and orthogonal to the flat surface of the substrate A magnetic step of applying an external magnetic field having a component to be fixed and fixing the magnetization direction of the pinned layer based on the orthogonal component.
According to such a configuration, since the horizontal component in which the curved component becomes stronger as the pitch of the magnets to which the external magnetic field is applied becomes narrower is used, the pinned layer of the pinned layer can be arranged even if the gap between the magnetoresistive effect elements is narrowed. The direction of magnetization can be fixed to a desired direction.

In one aspect of the present invention, in the magnetizing step, an external magnetic field in one direction perpendicular to the flat surface is applied in a predetermined first region included in one section of the flat surface of the substrate. Applying an external magnetic field in a predetermined region included in the section and different from the first region in a direction orthogonal to the flat surface and opposite to the one direction. Features.
According to such a configuration, a pinned layer having magnetization directions opposite to each other can be formed in one section. Therefore, a magnetic sensor having a small size and high detection accuracy can be manufactured by combining a magnetoresistive effect element having pinned layers whose magnetization directions are opposite to each other to form a bridge circuit.

Further, according to one aspect of the present invention, in the magnetizing step, a first magnet that makes one polar surface face the first region and a second magnet that makes the other region face the second region. Magnets are arranged on the same plane and the external magnetic field is applied.
Applying an external magnetic field having a component orthogonal to the flat surface by simply superimposing a jig (magnet array) arranged on the same plane so that the first magnet and the second magnet are aligned with each section on the substrate. As a result, the work of the magnetizing step can be simplified.

Further, according to one aspect of the present invention, in the magnetizing step, one of the first magnets is arranged so as to face four adjacent first regions while sharing one vertex of the rectangular section. In addition, one of the second magnets is disposed so as to face the four adjacent second regions while sharing another vertex located at the diagonal of the one vertex in the section. It is characterized by.
By adopting such a configuration, a single magnet can apply an external magnetic field to each of four adjacent sections sharing one apex, so that for a certain magnet size and arrangement pitch. The size of the compartment can be reduced efficiently.

According to another aspect of the present invention, in the magnetizing step, a magnetic body is disposed so as to sandwich each flat surface of the substrate with each of the first magnet and the second magnet.
By adopting such a configuration, among the directional components of the external magnetic field, the component orthogonal to the flat surface is stronger than the other directional components, so that the accuracy of the magnetization direction of the pinned layer to be fixed can be improved. it can.

According to another aspect of the present invention, in the film forming step, the pinned layer is provided with a first inclined surface provided so as to be in contact with the flat surface along a first direction in an in-plane direction of the flat surface; The film is formed on both the second inclined surface provided so as to be in contact with the flat surface along a second direction different from the first direction.
With such a configuration, in the magnetic sensor to be manufactured, a plurality of magnetoresistive elements having different sensitivity directions in the in-plane direction of the flat surface are formed. A magnetic sensor that can be separately measured can be manufactured.

One embodiment of the present invention includes a rectangular plate-shaped main body portion and at least a pinned layer, and an inclined surface of a first inclined surface provided along a first orientation in an in-plane direction of the flat surface of the main body portion. Further, the first magnetoresistive element formed with the first orientation as the longitudinal direction, and at least a pinned layer, is an orientation in the in-plane direction of the flat surface of the main body and is different from the first orientation. A second magnetoresistive element formed on the inclined surface of the second inclined surface provided along the two directions and having the second direction as the longitudinal direction. A first region defined by two points on each side of two sides that touch each other at the vertex, and another vertex located at a diagonal of the one vertex and each side of the two sides touched by the other vertex In each of the second regions partitioned by two points, the first magnetoresistance A magnetic sensor, wherein each of the fruit element and the second magnetoresistance effect element is disposed.
In this way, in the magnetic sensor manufacturing process, when a plurality of rectangular plate-like main body portions are arranged on the substrate as one section, each of the four adjacent sections sharing one vertex is shared. Since an external magnetic field can be applied with a single magnet facing each other, the size of the partition can be efficiently reduced with respect to a certain magnet size and arrangement pitch.

In one embodiment of the present invention, in the above-described magnetic sensor, the first magnetoresistive element and the second magnetoresistive element arranged in the first region have at least a magnetization direction of the pinned layer. The first magnetoresistive element and the second magnetoresistive element that have a component facing one direction perpendicular to the flat surface and are arranged in the second region have a magnetization direction of the pinned layer, It has a component that faces at least another direction orthogonal to the flat surface.
By doing so, a bridge circuit is configured by combining magnetoresistive effect elements having pinned layers whose magnetization directions are opposite to each other in one section, so that the magnetic sensor is small and has high detection accuracy. Can be produced.

  According to the magnetic sensor and the method for manufacturing the magnetic sensor described above, it is possible to reduce the size of the magnetic sensor.

It is a figure showing the whole magnetic sensor composition concerning a 1st embodiment. It is a 1st figure which shows the structure of the magnetic sensor which concerns on 1st Embodiment. It is a 2nd figure which shows the structure of the magnetic sensor which concerns on 1st Embodiment. It is a figure explaining the outline | summary of the ordered heat treatment process which concerns on 1st Embodiment. It is a figure which shows the arrangement | positioning relationship between the division on a board | substrate and the magnet array in the regularization heat treatment process which concerns on 1st Embodiment. It is a 1st figure explaining the mode of the external magnetic field applied in the regularization heat treatment process which concerns on 1st Embodiment. It is a 2nd figure explaining the mode of the external magnetic field applied in the regularization heat treatment process which concerns on 1st Embodiment. It is a 3rd figure explaining the mode of the external magnetic field applied in the ordered heat treatment process which concerns on 1st Embodiment. It is a figure explaining the azimuth | direction of magnetization of the pinned layer of the magnetic sensor which concerns on 1st Embodiment. It is a figure explaining the circuit structure of the magnetic sensor which concerns on 1st Embodiment. It is a 1st figure explaining the manufacturing method of the magnetic sensor which concerns on the comparison of 1st Embodiment. It is a 2nd figure explaining the manufacturing method of the magnetic sensor which concerns on the comparison of 1st Embodiment. It is a figure explaining the outline | summary of the regularization heat treatment process which concerns on the modification of 1st Embodiment.

<First Embodiment>
[Magnetic sensor structure]
Hereinafter, the magnetic sensor and the manufacturing method thereof according to the first embodiment will be described.
FIG. 1 is a diagram illustrating an overall configuration of the magnetic sensor according to the first embodiment.
The magnetic sensor 1 shown in FIG. 1 measures the magnetic field strength of an external magnetic field applied from the outside for each component (Hx, Hy, Hz) of three axes (± X direction, ± Y direction, ± Z direction) orthogonal to each other. A possible three-axis magnetic sensor.
One magnetic sensor 1 is formed in one section 1a of the flat surface of the substrate 1W (semiconductor wafer). In addition, although illustration is abbreviate | omitted in FIG. 1, the some division containing the division 1a is arranged in the matrix form so that it may mutually adjoin on the flat surface of the board | substrate 1W. The magnetic sensor 1 is cut out from the substrate 1W by dividing the substrate 1W into the plurality of sections at a certain stage of the manufacturing process. In the present embodiment, the plurality of sections including the section 1a are about 1 mm square.

As shown in FIG. 1, the magnetic sensor 1 includes 16 magnetoresistive elements X1A, X1B, X1C, X1D, X2A, X2B, X2C, X2D, Y1A, in a rectangular plate-shaped main body (section 1a). Y1B, Y1C, Y1D, Y2A, Y2B, Y2C, Y2D are provided.
Each of the 16 magnetoresistive elements X1A to Y2D is formed on an inclined surface (inclined surfaces 10a, 10b, 10c, 10d) provided on a flat surface of the substrate 1W.

In FIG. 1, the magnetoresistive elements X1A, X1B, X1C, X1D, X2A, X2B, X2C, and X2D (first magnetoresistive elements) are in the first direction (± Y direction) in the in-plane direction of the flat surface of the substrate 1W. ) On the first inclined surface provided so as to be in contact with the flat surface. The magnetoresistive elements X1A to X2D (first magnetoresistive elements) are all formed such that the first direction (± Y direction) is the longitudinal direction on the first inclined surface.
On the other hand, the magnetoresistive effect elements Y1A, Y1B, Y1C, Y1D, Y2A, Y2B, Y2C, and Y2D (second magnetoresistive effect elements) are different from the first orientation and are along the second orientation (± X direction) orthogonal to each other. And formed on a second inclined surface provided in contact with the flat surface. The magnetoresistive elements Y1A to Y2D (second magnetoresistive elements) are all formed such that the second direction (± X direction) is the longitudinal direction on the second inclined surface.

Further, the magnetoresistive effect elements X1A, X1B, X1C, and X1D are on the inclined surface 10a that is inclined so as to rise from the −X direction side to the + X direction side (go to the + Z direction side) among the first inclined surfaces. It is formed. On the other hand, the magnetoresistive effect elements X2A, X2B, X2C, and X2D are on the inclined surface 10b that is inclined so as to descend from the −X direction side to the + X direction side (proceed to the −Z direction side) among the first inclined surfaces. Formed.
Similarly, the magnetoresistive effect elements Y1A, Y1B, Y1C, Y1D are inclined surfaces 10c that incline so as to descend from the −Y direction side to the + Y direction side (go to the −Z direction side) among the second inclined surfaces. Formed on top. On the other hand, the magnetoresistive elements Y2A, Y2B, Y2C, and Y2D are on the inclined surface 10d that is inclined so as to rise from the -Y direction side to the + Y direction side (go to the + Z direction side) among the second inclined surfaces. It is formed.

Further, as shown in FIG. 1, the magnetoresistive elements X1A, X1C, X2A, X2C, Y1A, Y1C, Y2A, and Y2C are all at the apex P1 on the upper left (−X direction, + Y direction) of the section 1a. It is arranged in a predetermined area in the vicinity (second area AS). On the other hand, the magnetoresistive elements X1B, X1D, X2B, X2D, Y1B, Y1D, Y2B, and Y2D are all in a predetermined region near the apex P2 in the lower right side (+ X direction, −Y direction) of the section 1a ( It is arranged in the first area AN).
Specifically, as shown in FIG. 1, the first area AN is an area defined by a vertex P2 of the main body (section 1a) and two points R21 and R22 on each side of the two sides that are in contact with the vertex P2. It is. Further, the second area AS is an area defined by two points R11 and R12 on each side of the vertex P1 that is the vertex of the partition 1a and is located at the opposite corner of the vertex P2 and the two sides that are in contact with the vertex P1. .

FIG. 2 is a first diagram illustrating the structure of the magnetic sensor according to the first embodiment.
Specifically, FIG. 2 is a diagram schematically showing a cross-sectional structure of α-α ′ in FIG. As shown in FIG. 2, a bank portion 10 is formed on the flat surface of the substrate 1W. The bank portion 10 is formed by processing a part of the flat surface of the substrate 1W through a predetermined manufacturing process (film formation, resist coating, patterning, and etching steps).
As shown in FIG. 2, the bank portion 10 has inclined surfaces 10a and 10b inclined at a predetermined inclination angle θ (for example, θ = 45 °) with respect to the flat surface of the substrate 1W. The bank portion 10 (that is, the inclined surfaces 10a and 10b) extends along the ± Y direction (the depth direction on the paper surface), the magnetoresistive element X1A is inclined on the inclined surface 10a, and the magnetoresistive element X2A is inclined. On the surface 10b, each is formed so that the ± Y direction is the longitudinal direction.
In addition to the magnetoresistive effect element X1A and the magnetoresistive effect element X2A shown in FIG. 2, the magnetoresistive effect elements X1B, X1C, and X1D and the magnetoresistive effect elements X2B, X2C, and X2D are similarly inclined surfaces 10a and 10b, respectively. Formed on top.

  Although detailed illustration is omitted, the inclined surfaces 10 c and 10 d shown in FIG. 1 are formed by a bank portion similar to the bank portion 10. The bank portions (that is, the inclined surfaces 10c and 10d) are formed so as to extend along the ± X directions, and the magnetoresistive elements Y1A, Y1B, Y1C, and Y1D have a magnetoresistive effect on the inclined surface 10c. The effect elements Y2A, Y2B, Y2C, and Y2D are formed on the inclined surface 10d so that the ± X directions are the longitudinal directions, respectively (see FIG. 1).

  In the following description, the inclination direction of the inclined surface 10a is defined as ± X ′ axis, and the normal direction of the inclined surface 10a is defined as ± Z ′ axis.

FIG. 3 is a second diagram illustrating the structure of the magnetic sensor according to the first embodiment.
Specifically, FIG. 3 is a diagram illustrating a specific structure of the magnetoresistive element X1A shown in FIG. The structure of the other 15 magnetoresistive elements X1B to Y2D is also the same as that of the magnetoresistive element X1A, and the description thereof is omitted.

3A is a schematic diagram when the magnetoresistive element X1A is viewed in plan from the + Z ′ direction side (see FIG. 2), and FIG. 3B is a diagram of β-β ′ in FIG. FIG.
As shown in FIG. 3A, the magnetoresistive effect element X1A has a rectangular shape in plan view, and is arranged such that its longitudinal direction is along the ± Y direction. The magnetoresistive element X1A is electrically connected to an external circuit by the wiring layers 31a and 31b. For example, positive and negative electrodes of a constant voltage source (not shown) are connected to the wiring layers 31a and 31b, respectively. In response to application of a predetermined power supply voltage Vin + (for example, 3V) and ground voltage Vin− (for example, 0V) by the constant voltage source, the wiring layer 31a (wiring layer 31b) via the magnetoresistive effect element X1A A current flows to 31b (wiring layer 31a).

As shown in FIG. 3B, the magnetoresistive element X1A includes a pinning layer 30a made of an antiferromagnetic material, a pinned layer 30b whose magnetization direction is fixed by the pinning layer 30a, and a spacer layer 30c made of a nonmagnetic material. , And a free layer 30d in which the direction of magnetization changes according to an external magnetic field is laminated to form a spin valve structure.
With this spin valve structure, the magnetoresistive effect element X1A can detect the strength of the external magnetic field by changing the resistance value between the wiring layer 31a and the wiring layer 31b according to the external magnetic field.
Note that the structure of the magnetoresistive effect element X1A shown in FIGS. 3A and 3B is an example, and the structure can be appropriately changed as long as the function of the spin valve can be exhibited. For example, the film formation order of the free layer 30d, the pinned layer 30b, and the pinning layer 30a can be interchanged, and further layers other than those described above may be inserted to improve characteristics as a magnetoresistive effect element. .
In addition, as for materials, film forming conditions, and the like used for each of the pinning layer 30a, the pinned layer 30b, the spacer layer 30c, and the free layer 30d, a detailed description is omitted because known manufacturing techniques can be applied. The ordering heat treatment process for fixing the magnetization direction of the pinned layer to a desired direction will be described later.

The magnetoresistive effect element X1A is manufactured by a predetermined manufacturing method (ordering heat treatment step) to be described later so that the magnetization direction of the pinned layer 30b is fixed in a predetermined direction (−X ′ direction). (FIG. 3A).
Further, in the magnetoresistive effect element X1A, in a state where no external magnetic field exists (hereinafter, also referred to as “initial state”), the magnetization direction of the free layer 30d is a specific direction (+ Y direction) based on the shape of the free layer 30d. ). Specifically, the free layer 30d is formed into a rectangular shape in plan view, and the magnetization anisotropy of the free layer 30d is aligned with the longitudinal direction (+ Y direction) of the rectangular shape using the shape anisotropy. (See FIGS. 3A and 3B).

[Regularized heat treatment process]
FIG. 4 is a diagram for explaining the outline of the ordered heat treatment process according to the first embodiment.
The ordered heat treatment step is a step of fixing the magnetization direction of the pinned layer 30b (FIG. 3) of the magnetoresistive elements X1A to Y2D (FIG. 1) to a desired direction.
Here, the process before the regularized heat treatment process will be briefly described. First, a bank part (the bank part 10 etc. (see FIG. 2)) is formed for each section (section 1a etc.) of the flat surface of the substrate 1W. The forming step is performed. For example, in the formation step, first, an oxide film (for example, a film thickness of 5 μm) made of a SiO ₂ film is formed by CVD (Chemical Vapor Deposition) or the like, and then a resist is applied to the upper layer to form a resist film (for example, , A film thickness of 5 μm) is formed. Then, the resist film is subjected to pattern cut according to the arrangement pattern of the bank portion 10 and the like, and then the resist film is formed into a tapered shape (tapered) by heat treatment or the like. Thereafter, dry etching is performed under conditions where the oxide film and the resist film are etched at substantially the same ratio. Thereby, as shown in FIG. 2, the bank part 10 which has the inclined surfaces 10a and 10b is formed. Similarly, bank portions having inclined surfaces 10c and 10d are also formed.
Thereafter, the multilayer film constituting the magnetoresistive elements X1A to Y2D (FIG. 1), that is, the pinning layer 30a, the pinned layer 30b, the spacer layer 30c, and the free layer 30d (FIG. 3) is formed on the inclined surface by using a sputtering method or the like. A film forming step for sequentially forming films on 10a to 10d (FIG. 1) is performed.
In addition, the specific process of the formation step described above is merely an example, and any other mode is possible as long as a desired inclined surface can be formed on the flat surface of the semiconductor wafer (substrate 1W). It doesn't matter. For example, in the above-described formation step, it has been described that the inclined surfaces 10a to 10d are formed by providing a bank portion (the bank portion 10 or the like) protruding upward (+ Z direction) from the flat surface. May be configured to form the inclined surfaces 10a to 10d by providing a groove portion recessed downward (−Z direction) from the flat surface.

Next, a regularized heat treatment step (magnetization step) for fixing the magnetization direction of the pinned layer 30b is performed.
As shown in FIG. 4, a substrate 1 </ b> W in which a multilayer film such as a pinned layer 30 b is formed on the inclined surfaces 10 a to 10 d after the formation step and the film formation step in the ordered heat treatment step is prepared in advance. Overlay the magnet array 20. In the magnet array 20, permanent bar magnets (first magnet 20N and second magnet 20S to be described later) are regularly arranged on the same plane so as to correspond to the respective sections (section 1a and the like) arranged on the flat surface of the substrate 1W. It is a jig arranged on the top.
In the ordering heat treatment step, as shown in FIG. 4, the back surface of the substrate 1W (a surface different from the flat surface on which the magnetoresistive effect elements X1A to Y2D are formed) is opposed to the flat surface of the magnet array 20. Overlay and fix both. At this time, the alignment is performed so that each section on the flat surface of the substrate 1W corresponds to the arrangement pattern of the permanent bar magnets (first magnet 20N, second magnet 20S) in the magnet array 20.
While maintaining this state, by heating in a vacuum and leaving it to stand, the direction of magnetization of each pinned layer 30b is fixed to the direction according to the external magnetic field applied by each permanent bar magnet (precisely, By the heat treatment, the magnetization direction of the pinning layer 30a is fixed, and the magnetization direction of the pinned layer 30b is fixed based on the interaction with the pinning layer 30a whose magnetization is fixed.

FIG. 5 is a diagram showing an arrangement relationship between the partitions on the substrate and the magnet array in the ordered heat treatment process according to the first embodiment.
As shown in FIG. 5, the magnet array 20 includes a first magnet 20 </ b> N that makes the N-polar surface (one polar surface) face the back surface of the substrate 1 </ b> W, and an S-pole surface (others) The second magnets 20S that are opposed to each other in the polar plane) are alternately arranged in a matrix. The first magnet 20N and the second magnet 20S are arranged in a direction inclined by 45 ° with respect to the arrangement direction of the sections (section 1a and the like) on the flat surface of the substrate 1W.

As shown in FIG. 5, the polar surface of the first magnet 20N facing the N-pole surface is arranged so that the center thereof overlaps the apex P2 of the section 1a. Similarly, the polar surface of the second magnet 20S facing the surface of the south pole is arranged so that the center thereof overlaps the vertex P1 (vertex located at the diagonal of the vertex P2) of the section 1a.
Also, one first magnet 20N shares one vertex (vertex P2) of the partition 1a and is adjacent to all four regions (first regions AN included in each of the partitions 1a, 1b, 1c, and 1d). It is arranged so as to face. Similarly, one second magnet 20S is included in each of four adjacent regions (sections 1a, 1e, 1f, and 1g) sharing the vertex P1 (vertex located on the diagonal of the vertex P2 in the section 1a). The second region AS) is arranged so as to face all of the second region AS). Thereby, in the regularization heat treatment step, in all the sections arranged on the flat surface of the substrate 1W, the region where the N-pole surface of the first magnet 20N faces and the surface of the S-pole of the second magnet 20S face each other. And a region to be used.
In addition, in the magnet array 20 mentioned above, although the shape of each polar surface of the 1st magnet 20N and the 2nd magnet 20S shall be formed in the rectangular shape, the magnet array 20 which concerns on other embodiment is this It is not limited to an aspect. For example, each polar surface of the first magnet 20N and the second magnet 20S may be circular.

FIG. 6 is a first diagram for explaining a state of an external magnetic field applied in the ordered heat treatment process according to the first embodiment.
As shown in FIG. 6, in the ordered heat treatment step, the magnet array 20 is disposed below the substrate 1W (in the −Z direction). The first magnet 20N provided in the magnet array 20 is arranged so that the polar surface of the N pole faces the back surface of the substrate 1W, and the second magnet 20S makes the polar surface of the S pole face the back surface of the substrate 1W. Is arranged. In the section 1a on the flat surface of the substrate 1W, inclined surfaces 10a to 10d (FIG. 1) on which the magnetoresistive effect elements X1A to Y2D are formed through the manufacturing process are formed (in FIG. 6, as an example, Only the inclined surfaces 10a and 10d are shown).

Adjacent first magnet 20N and second magnet 20S have polar surfaces with different polarities (N pole, S pole) opposed to substrate 1W. As a result, an external magnetic field H that travels from the polar face of the N pole of the first magnet 20N to the polar face of the S pole of the second magnet 20S is applied to the substrate 1W (see FIG. 6). Specifically, the external magnetic field H travels upward (+ Z direction) from the polar face of the N pole of the first magnet 20N and draws an arc so that the polarity of the S pole of the adjacent second magnet 20S is drawn. The light enters the surface downward (−Z direction).
Thereby, in a predetermined first area AN included in the section 1a, an external magnetic field in one direction (+ Z direction) orthogonal to the flat surface of the substrate 1W is applied, and the second area is different from the first area AN. In the AS, an external magnetic field in another direction (−Z direction) orthogonal to the flat surface of the substrate 1W is applied.

FIG. 7 is a second diagram for explaining the state of the external magnetic field applied in the ordered heat treatment process according to the first embodiment.
FIG. 7 shows, in detail, the vicinity of the bank portion 10 where the magnetoresistive effect elements X1A and X2A are formed in the section 1a on the flat surface of the substrate 1W. Below the position where the magnetoresistive effect elements X1A and X2A are arranged (in the −Z direction), since the polar face of the S pole of the second magnet 20S is arranged, the magnetoresistive effect elements X1A and X2A include An external magnetic field H facing downward (−Z direction) is applied (see FIG. 7). The pinned layer 30b (not shown in FIG. 7) of the magnetoresistive effect elements X1A and X2A formed on the inclined surfaces 10a and 10b is heated in a state where an external magnetic field H directed downward is applied, Each magnetization orientation is fixed so as to have a component in the -Z direction.

Specifically, the orientation of magnetization of the pinned layer 30b (that is, the pinned layer 30b constituting the magnetoresistive effect element X1A) formed on the inclined surface 10a is the in-plane direction of the inclined surface 10a and the −Z direction. It is fixed in the direction c1 (−X ′ direction) having the following components. Similarly, the magnetization direction of the pinned layer 30b (that is, the pinned layer 30b constituting the magnetoresistive effect element X2A) formed on the inclined surface 10b is the in-plane direction of the inclined surface 10b and the component in the −Z direction. Is fixed in the direction c2 (−Z ′ direction). Here, the pinned layer 30b formed on the inclined surface 10a is inclined so as to descend from the + X direction to the -X direction (toward the -Z direction). Therefore, the magnetization direction c1 of the pinned layer 30b has a component in the -Z direction and a component in the -X direction. In contrast to the inclined surface 10a, the pinned layer 30b formed on the inclined surface 10b is inclined so as to descend from the −X direction to the + X direction (toward the −Z direction). Therefore, the magnetization direction c2 of the pinned layer 30b has a −Z direction component and a + X direction component.
The other magnetoresistive elements X1C, X2C, Y1A, Y2A, Y1C, and Y2C to which the lower external magnetic field H is applied are formed as in the magnetoresistive elements X1A and X2A shown in FIG. The magnetization is fixed in the in-plane direction of each of the inclined surfaces 10a to 10d (FIG. 1) and having the −Z direction component.

FIG. 8 is a third diagram illustrating the state of the external magnetic field applied in the ordered heat treatment process according to the first embodiment.
FIG. 8 shows in detail the vicinity of the bank portion 10 where the magnetoresistive effect elements X1B and X2B are formed in the flat surface (section 1a) of the substrate 1W. Below the position where the magnetoresistive effect elements X1B and X2B are arranged (in the −Z direction), the N-polar polarity surface of the first magnet 20N is arranged, so that the magnetoresistive effect elements X1B and X2B include An external magnetic field H facing upward (+ Z direction) is applied (see FIG. 8). The pinned layer 30b (not shown in FIG. 8) of the magnetoresistive effect elements X1B and X2B formed on the inclined surfaces 10a and 10b is heated in a state where an external magnetic field H facing upward is applied, The direction of magnetization is fixed so as to have a component in the + Z direction.

Specifically, the orientation of magnetization of the pinned layer 30b (that is, the pinned layer 30b constituting the magnetoresistive effect element X1B) formed on the inclined surface 10a is the in-plane direction of the inclined surface 10a and is in the + Z direction. It is fixed in the direction c3 (+ X ′ direction) having the component. Similarly, the magnetization direction of the pinned layer 30b (that is, the pinned layer 30b constituting the magnetoresistive effect element X2B) formed on the inclined surface 10b is the in-plane direction of the inclined surface 10b and has a component in the + Z direction. It is fixed to the bearing c4 (+ Z ′ direction). Here, the pinned layer 30b formed on the inclined surface 10a is inclined so as to rise from the −X direction to the + X direction (toward the + Z direction). Therefore, the magnetization direction c3 of the pinned layer 30b has a component in the + Z direction and a component in the + X direction. In contrast to the inclined surface 10a, the pinned layer 30b formed on the inclined surface 10b is inclined so as to rise from the + X direction to the -X direction (toward the + Z direction). Therefore, the magnetization direction c4 of the pinned layer 30b has a + Z direction component and a -X direction component.
The other magnetoresistive elements X1D, X2D, Y1B, Y2B, Y1D, and Y2D to which the upper external magnetic field H is applied are formed as in the magnetoresistive elements X1B and X2B shown in FIG. The magnetization is fixed in the in-plane direction of each of the inclined surfaces 10a to 10d (FIG. 1) and having a + Z direction component.

FIG. 9 is a diagram for explaining the magnetization orientation of the pinned layer of the magnetic sensor according to the first embodiment.
As shown in FIGS. 6 to 8, the magnetization direction of the pinned layer 30b in each of the magnetoresistive effect elements X1A to Y2D that has undergone the regularization heat treatment step is the direction of the external magnetic field H applied by the magnet array 20, and , Each is fixed based on the orientation of the inclined surfaces 10a to 10d (FIG. 1) to be formed.

Specifically, the magnetoresistive elements X1A, X1C, X2A, X2C, Y1A, Y1C, Y2A, and Y2C arranged in the vicinity of the apex P1 of the section 1a are components orthogonal to the flat surface of the substrate 1W in the −Z direction. Belongs to a region (second region AS) to which an external magnetic field H is applied. Therefore, after the ordering heat treatment step, as shown in FIG. 9, the magnetoresistive elements X1A and X1C are in-plane directions of the inclined surface 10a and have a −X direction component and a −Z direction component. It is fixed in the direction c1. In addition, the magnetoresistive elements X2A and X2C are fixed in the in-plane direction of the inclined surface 10b and in the direction c2 having a + X direction component and a −Z direction component. In addition, the magnetoresistive elements Y1A and Y1C are fixed in the in-plane direction of the inclined surface 10c and in the direction d1 having a + Y direction component and a −Z direction component. In addition, the magnetoresistive elements Y2A and Y2C are fixed in the in-plane direction of the inclined surface 10d and in the direction d2 having a −Y direction component and a −Z direction component.
Thus, all the magnetoresistive effect elements (the first magnetoresistive effect element and the second magnetoresistive effect element) arranged in the second region AS have the magnetization direction of the pinned layer at least on the flat surface of the section 1a. It has a component facing one orthogonal direction (−Z direction).

On the other hand, the magnetoresistive elements X1B, X1D, X2B, X2D, Y1B, Y1D, Y2B, and Y2D arranged in the vicinity of the vertex P2 of the section 1a are external magnetic fields having a component orthogonal to the + Z direction on the flat surface of the substrate 1W. It belongs to the region to which H is applied (first region AN). Therefore, after the ordering heat treatment step, as shown in FIG. 9, the magnetoresistive effect elements X1B and X1D are in the in-plane direction of the inclined surface 10a, and have an orientation c3 having a + X direction component and a + Z direction component. Fixed to. In addition, the magnetoresistive effect elements X2B and X2D are fixed in an in-plane direction of the inclined surface 10b and in an orientation c4 having a −X direction component and a + Z direction component. In addition, the magnetoresistive elements Y1B and Y1D are fixed in an in-plane direction of the inclined surface 10c and in an orientation d3 having a −Y direction component and a + Z direction component. In addition, the magnetoresistive elements Y2B and Y2D are fixed in an in-plane direction of the inclined surface 10d and in an orientation d4 having a + Y direction component and a + Z direction component.
As described above, all the magnetoresistive effect elements (the first magnetoresistive effect element and the second magnetoresistive effect element) arranged in the first region AN have the magnetization direction of the pinned layer at least on the flat surface of the section 1a. It has a component that faces another perpendicular direction (+ Z direction).

  As described above, in the ordered heat treatment step, the external magnetic field H in the + Z direction and −Z direction having components orthogonal to the flat surface of the substrate 1W is applied, and the orthogonal components (± Z direction components) are applied. Based on this, the magnetization orientation of the pinned layer 30b formed on the flat surface of the substrate 1W is fixed.

  Although not shown in FIG. 9, the magnetization directions (directions My and Mx described later) of the free layers 30d of the magnetoresistive elements X1A to Y2D are directions along the respective longitudinal directions (FIG. 3). reference). For example, the magnetization directions of the magnetoresistive elements X1A, X1B, X1C, X1D, X2A, X2B, X2C, and X2D are all aligned so as to face the + Y direction by applying a separate external magnetic field. Similarly, the magnetization directions of the magnetoresistive elements Y1A, Y1B, Y1C, Y1D, Y2A, Y2B, Y2C, and Y2D are all aligned so as to face the + X direction by applying a separate external magnetic field.

[Circuit configuration]
FIG. 10 is a diagram illustrating the circuit configuration of the magnetic sensor according to the first embodiment.
Next, a circuit configuration constituted by the magnetoresistive elements X1A to Y2D shown in FIG. 9 will be described with reference to FIG.
In the manufacturing process of the magnetic sensor 1 according to the present embodiment, in the wiring forming step performed after the ordering heat treatment process, wirings (for example, the wiring layer 31a shown in FIG. 3) that electrically connects the magnetoresistive elements X1A to Y2D and the like. , 31b, etc.). Specifically, the magnetoresistive elements X1A to Y2D are connected by wiring as shown in FIGS. Here, as shown in FIG. 9, the first inclined surfaces (inclined surfaces 10a and 10b) and the second inclined surfaces (inclined surfaces 10c and 10d) are provided in both the first area AN and the second area AS, respectively. Is formed. In the wiring formation step, a bridge in which each magnetoresistive effect element belonging to the first area AN and each magnetoresistive effect element belonging to the second area AS are assembled together having the same inclined surfaces 10a to 10d. Form a circuit.

For example, as shown in FIG. 10A, in the bridge circuit BX1, the magnetoresistive effect element X1A and the magnetoresistive effect element X1B are connected in series between the power supply terminal Q1 and the ground terminal Q2. At this time, one end of the magnetoresistive effect element X1A is connected to the power supply terminal Q1, and one end of the magnetoresistive effect element X1B is connected to the ground terminal Q2. Similarly, the magnetoresistive effect element X1D and the magnetoresistive effect element X1C are connected in series between the power supply terminal Q1 and the ground terminal Q2. At this time, one end of the magnetoresistive effect element X1D is connected to the power supply terminal Q1, and one end of the magnetoresistive effect element X1C is connected to the ground terminal Q2. Here, a positive terminal and a negative terminal of a constant voltage source (not shown) are connected to the power supply terminal Q1 and the ground terminal Q2, respectively, a power supply voltage Vin + (for example, 3V) is applied to the power supply terminal Q1, and a ground voltage is applied to the ground terminal Q2. Vin− (for example, 0V) is applied.
As shown in FIG. 10A, the bridge circuit BX1 includes a potential between the magnetoresistive effect element X1A and the magnetoresistive effect element X1B, and between the magnetoresistive effect element X1D and the magnetoresistive effect element X1C. An output voltage Vx1 which is a potential difference between the potential and the potential is output.

  The magnetization directions c1 and c3 of the pinned layer 30b (FIG. 3) of each of the magnetoresistive elements X1A to X1D are fixed in the in-plane direction of the inclined surface 10a and opposite to each other. Further, the magnetization direction My of the free layer 30d (FIG. 3) of each of the magnetoresistive effect elements X1A to X1D changes in the in-plane direction of the inclined surface 10a according to the applied external magnetic field. That is, the bridge circuit BX1 changes the output voltage Vx1 according to the combined component of the + X direction and the + Z direction in the applied external magnetic field.

On the other hand, as shown in FIG. 10B, in the bridge circuit BX2, the magnetoresistive effect element X2A and the magnetoresistive effect element X2B are connected in series between the power supply terminal Q1 and the ground terminal Q2. At this time, one end of the magnetoresistive effect element X2A is connected to the power supply terminal Q1, and one end of the magnetoresistive effect element X2B is connected to the ground terminal Q2. Similarly, the magnetoresistive element X2D and the magnetoresistive element X2C are connected in series between the power supply terminal Q1 and the ground terminal Q2. At this time, one end of the magnetoresistive effect element X2D is connected to the power supply terminal Q1, and one end of the magnetoresistive effect element X2C is connected to the ground terminal Q2.
10B, the bridge circuit BX2 includes a potential between the magnetoresistive effect element X2A and the magnetoresistive effect element X2B, and between the magnetoresistive effect element X2D and the magnetoresistive effect element X2C. An output voltage Vx2 that is a potential difference between the potential and the potential is output.

  The magnetization directions c2 and c4 of the pinned layer 30b (FIG. 3) of the magnetoresistive effect elements X2A to X2D are fixed in the in-plane direction of the inclined surface 10b and opposite to each other. Further, the magnetization direction My of the free layer 30d (FIG. 3) of each of the magnetoresistive effect elements X2A to X2D changes in the in-plane direction of the inclined surface 10b according to the applied external magnetic field. That is, the bridge circuit BX2 changes the output voltage Vx2 according to the combined component of the + X direction and the −Z direction in the applied external magnetic field.

The magnetic sensor 1 separates and calculates the ± X direction component and the ± Z direction component of the applied external magnetic field by combining the output voltage Vx1 of the bridge circuit BX1 and the output voltage Vx2 of the bridge circuit BX2. Can do. Specifically, the component Hx in the ± X direction of the external magnetic field can be obtained by the following equation (1).
Hx = kx (Vx1 + Vx2) / cos θ (1)
Here, the inclination angle θ is an angle of the inclined surfaces 10a and 10b with respect to the flat surface of the substrate 1W (see FIG. 2). Further, the sensitivity coefficient kx is a proportional constant of the ± H direction component Hx (magnetic field strength in the ± X direction) of the external magnetic field with respect to the output voltages Vx1 and Vx2.

Further, as shown in FIG. 10C, in the bridge circuit BY1, the magnetoresistive effect element Y1A and the magnetoresistive effect element Y1B are connected in series between the power supply terminal Q1 and the ground terminal Q2. At this time, one end of the magnetoresistive effect element Y1A is connected to the power supply terminal Q1, and one end of the magnetoresistive effect element Y1B is connected to the ground terminal Q2. Similarly, the magnetoresistive element Y1D and the magnetoresistive element Y1C are connected in series between the power supply terminal Q1 and the ground terminal Q2. At this time, one end of the magnetoresistive effect element Y1D is connected to the power supply terminal Q1, and one end of the magnetoresistive effect element Y1C is connected to the ground terminal Q2.
Further, as shown in FIG. 10C, the bridge circuit BY1 includes a potential between the magnetoresistive effect element Y1A and the magnetoresistive effect element Y1B, and between the magnetoresistive effect element Y1D and the magnetoresistive effect element Y1C. An output voltage Vy1 which is a potential difference between the potential and the potential is output.

  The magnetization directions d1 and d3 of the pinned layer 30b (FIG. 3) of the magnetoresistive elements Y1A to Y1D are fixed in the in-plane direction of the inclined surface 10c and opposite to each other. Further, the magnetization direction Mx of the free layer 30d (FIG. 3) of each of the magnetoresistive elements Y1A to Y1D changes in the in-plane direction of the inclined surface 10c according to the applied external magnetic field. That is, the bridge circuit BY1 changes the output voltage Vy1 according to the combined component of the + Y direction and the −Z direction in the applied external magnetic field.

Similarly, as shown in FIG. 10D, in the bridge circuit BY2, the magnetoresistive effect element Y2A and the magnetoresistive effect element Y2B are connected in series between the power supply terminal Q1 and the ground terminal Q2. At this time, one end of the magnetoresistive effect element Y2A is connected to the power supply terminal Q1, and one end of the magnetoresistive effect element Y2B is connected to the ground terminal Q2. Similarly, the magnetoresistive element Y2D and the magnetoresistive element Y2C are connected in series between the power supply terminal Q1 and the ground terminal Q2. At this time, one end of the magnetoresistive element Y2D is connected to the power supply terminal Q1, and one end of the magnetoresistive element Y2C is connected to the ground terminal Q2.
Further, as shown in FIG. 10D, the bridge circuit BY2 includes a potential between the magnetoresistive effect element Y2A and the magnetoresistive effect element Y2B, and between the magnetoresistive effect element Y2D and the magnetoresistive effect element Y2C. An output voltage Vy2 which is a potential difference between the potential and the potential is output.

  The magnetization directions d2 and d4 of the pinned layer 30b (FIG. 3) of the magnetoresistive elements Y2A to Y2D are fixed in the in-plane direction of the inclined surface 10d and opposite to each other. Further, the magnetization direction Mx of the free layer 30d (FIG. 3) of each of the magnetoresistive elements Y2A to Y2D changes in the in-plane direction of the inclined surface 10d in accordance with the applied external magnetic field. That is, the bridge circuit BY2 changes the output voltage Vy2 according to the combined component of the + Y direction and the + Z direction in the applied external magnetic field.

The magnetic sensor 1 combines the output voltage Vy1 of the bridge circuit BY1 and the output voltage Vy2 of the bridge circuit BY2 to separately calculate the ± Y direction component and the ± Z direction component of the applied external magnetic field. Can do. Specifically, the ± Y direction component Hy of the external magnetic field can be obtained by the following equation (2).
Hy = ky (Vy1 + Vy2) / cos θ (2)
Here, the sensitivity coefficient ky is a proportional constant of the component Hy (magnetic field strength in the ± Y direction) of the external magnetic field with respect to the output voltages Vy1 and Vy2.

Further, the component Hz in the ± Z direction of the external magnetic field can be obtained by the following equation (3).
Hz = kz (Vy1-Vy2) / sin θ (3)
Here, the sensitivity coefficient kz is a proportionality constant of the component Hz (magnetic field strength in the ± Z direction) of the external magnetic field with respect to the output voltages Vy1 and Vy2.

The magnetic sensor 1 separately receives the output voltages Vx1, Vx2, Vy1, and Vy2 of the bridge circuits BX1, BX2, BY1, and BY2, and calculates a magnetic field that calculates each direction component (Hx, Hy, Hz) of the external magnetic field. An intensity calculation unit is provided. In this case, for example, the magnetic field intensity calculation unit inputs the output voltage Vx1 through the A / D conversion circuit and executes the step of acquiring the sampling value SVx1, and then similarly through the A / D conversion circuit. The steps of acquiring the sampling values SVx2, SVy1, SVy2 by sequentially inputting the output voltages Vx2, Vy1, Vy2 may be executed. Thereafter, the magnetic field intensity calculation unit performs the calculations of Expressions (1) to (3) based on the acquired sampling values SVx1 to SVy2, and calculates each direction component (Hx, Hy, Hz) of the external magnetic field.
In this case, each of the bridge circuits BX1, BX2, BY1, and BY2 is connected to the magnetic field strength calculation unit (A / D conversion circuit) via an amplifier (output amplifier) that amplifies the output voltages Vx1, Vx2, Vy1, and Vy2. It may be output.

[Function and effect]
FIG. 11 is a first diagram illustrating a method for manufacturing a magnetic sensor according to the comparison of the first embodiment. FIG. 12 is a second view for explaining the magnetic sensor manufacturing method according to the first embodiment.
Next, the effect of the manufacturing method of the magnetic sensor 1 mentioned above is demonstrated, comparing with the comparison shown to FIG. 11, FIG.

As shown in FIG. 11, the magnetic sensor 9 (FIG. 12) according to the comparison of the first embodiment is formed for each section (section 1a ′) arranged on the flat surface of the substrate 1W.
Here, also in the ordered heat treatment step according to the comparison, similarly to the ordered heat treatment step according to the first embodiment, a substrate 1W on which a multilayer film such as a pinned layer 30b is formed is prepared with a magnet prepared in advance. A predetermined heat treatment is performed on the array 20 (see FIG. 4).

  As shown in FIG. 11, the magnet array 20 includes a first magnet 20 </ b> N that makes the N-polar surface (one polar surface) face the substrate 1 </ b> W, and an S-polar surface (the other polar surface) to the substrate 1 </ b> W. The opposing second magnets 20S are alternately arranged in a matrix. However, unlike the first embodiment, the first magnet 20N and the second magnet 20S are arranged in a one-to-one correspondence with each section (section 1a ', etc.) on the flat surface of the substrate 1W.

  Specifically, as shown in FIG. 11, the polar surface of the first magnet 20N facing the N-pole surface is overlapped with the center of the section 1a ′, which is one section of the flat surface of the substrate 1W. It is arranged in. Similarly, the polar face of the second magnet 20S that faces the south pole face is arranged so that the center thereof overlaps the center of another section adjacent to the section 1a '. Therefore, in this case, the external magnetic field H ′ generated by the magnet array 20 emerges from the polar surface of the first magnet 20N, and the polar surfaces of the four second magnets 20S arranged in the ± X and ± Y directions. Head to each one.

Here, FIG. 12 shows the structure of the magnetic sensor 9 according to the comparison and the magnetization direction of the pinned layer 30b (not shown in FIG. 12) of each of the magnetoresistive elements X1A to Y2D.
As shown in FIG. 12, the magnetic sensor 9 includes twelve magnetoresistive elements X1A, X1B, X1C, X1D, Y1A, Y1B, Y1C, Y1D, Y2A, Y2B, Y2C in the rectangular plate-shaped section 1a ′. Y2D.
Among the twelve magnetoresistive elements X1A to Y2D, the magnetoresistive elements X1A, X1B, X1C, and X1D are formed on the flat surface of the substrate 1W so that the ± Y direction is the longitudinal direction. The magnetoresistive elements Y1A, Y1B, Y1C, Y1D, Y2A, Y2B, Y2C, and Y2D are all formed on inclined surfaces (inclined surfaces 10c and 10d) that are inclined with respect to the flat surface of the substrate 1W.

  Specifically, the magnetoresistive elements Y1A, Y1B, Y1C, and Y1D are formed on an inclined surface 10c that is inclined so as to descend from the −Y direction side to the + Y direction side (go to the −Z direction side). On the other hand, the magnetoresistive elements Y2A, Y2B, Y2C, and Y2D are formed on the inclined surface 10d that is inclined so as to rise from the −Y direction side to the + Y direction side (go to the + Z direction side).

  As shown in FIG. 12, the magnetoresistive elements X1A and X1C are arranged near the center of the side on the −X direction side of the section 1a ′, and the magnetoresistive elements X1B and X1D are in the + X direction of the section 1a ′. Arranged near the center of the side. Further, the magnetoresistive elements Y1A, Y1C, Y2B, Y2D are arranged near the center of the side on the + Y direction side of the section 1a ′, and the magnetoresistive elements Y1B, Y1D, Y2A, Y2C are −Y of the section 1a ′. Arranged near the center of the direction side.

  The magnetization direction of the pinned layer 30b in each of the magnetoresistive effect elements X1A to Y2D that has undergone the ordered heat treatment step is the horizontal component of the external magnetic field H ′ (FIG. 11) applied by the magnet array 20 (the surface of the flat surface of the substrate 1W). It is fixed based on the direction of the inward component.

  Specifically, the direction of magnetization of the pinned layer 30b of the magnetoresistive effect elements X1A and X1C arranged near the center of the side on the −X direction side of the section 1a ′ is the external magnetic field H ′ in the −X direction (FIG. 11). ), The orientation c1 ′ having only the component in the −X direction is fixed. Further, the magnetization direction of the pinned layer 30b of the magnetoresistive effect elements X1B and X1D arranged near the center of the side on the + X direction side of the section 1a ′ is determined in the + X direction by the external magnetic field H ′ (FIG. 11) in the + X direction. It is fixed to the direction c2 ′ having only the component.

Similarly, the magnetoresistive elements Y1A and Y1C have an in-plane direction of the inclined surface 10c and an orientation d1 having a + Y direction component and a −Z direction component due to the external magnetic field H ′ (FIG. 11) in the + Y direction. Fixed. In addition, the magnetoresistive elements Y2B and Y2D are fixed by the + Y direction external magnetic field H ′ in the in-plane direction of the inclined surface 10d and in the direction d4 having a + Y direction component and a + Z direction component.
Furthermore, the magnetoresistive effect elements Y1B and Y1D are in the in-plane direction of the inclined surface 10c by the external magnetic field H ′ (FIG. 11) in the −Y direction, and in the direction d3 having the −Y direction component and the + Z direction component. Fixed. In addition, the magnetoresistive elements Y2A and Y2C are fixed in the in-plane direction of the inclined surface 10d by the external magnetic field H ′ in the −Y direction, and the azimuth d2 having the −Y direction component and the −Z direction component. .

Of the twelve magnetoresistive effect elements X1A to Y2D of the magnetic sensor 9 according to the comparative example, the set of the magnetoresistive effect elements X1A, X1B, X1C, and X1D is connected to form a bridge circuit. Similarly, the set of magnetoresistive elements Y1A, Y1B, Y1C, and Y1D and the set of magnetoresistive elements Y2A, Y2B, Y2C, and Y2D are similarly wire-connected to form a bridge circuit (FIG. 10).
The magnetic sensor 9 according to the comparison is a three-axis magnetic sensor that can measure by three components (Hx, Hy, Hz) orthogonal to each other with the above configuration.

  Here, using the pitch of the magnet array 20 as a reference, the sizes of the magnetic sensor 1 according to the first embodiment and the magnetic sensor 9 according to the comparison (that is, the size of the section 1a and the section 1a ′) are compared. Then, the magnetic sensor 1 has a size of 1 / √2 compared to the magnetic sensor 9.

As described above, in the ordered heat treatment step (magnetization step) according to the first embodiment, the external magnetic field H having a component orthogonal to the flat surface of the semiconductor wafer (substrate 1W) is applied to the orthogonal component. Based on this, the magnetization orientation of the pinned layer is fixed.
Thereby, since the horizontal component in which the curved component becomes stronger as the pitch of the permanent magnets (the first magnet and the second magnet) becomes smaller in the external magnetic field H is not used, the distance between the magnetoresistive effect elements is reduced. In addition, the magnetization direction of the pinned layer can be fixed to a desired direction.

In the ordered heat treatment step according to the first embodiment, an external magnetic field H in one direction (+ Z direction) perpendicular to the flat surface is applied to the first region in the predetermined first region AN included in the section 1a. In the second region AS different from AN, an external magnetic field H is applied in the direction opposite to one direction (+ Z direction) (−Z direction).
Thereby, a pinned layer having magnetization directions opposite to each other can be formed in one section. Therefore, a magnetic sensor having a small size and high detection accuracy can be manufactured by combining a magnetoresistive effect element having pinned layers whose magnetization directions are opposite to each other to form a bridge circuit.

In the above ordered heat treatment process, the first magnet 20N having one polar face (N pole face) opposed to the first area AN and the other polar face (S pole) with respect to the second area AS. Are arranged on the same plane, and the external magnetic field H is applied.
As a result, the magnet array 20 which is a jig arranged on the same plane so that the first magnet 20N and the second magnet 20S are aligned with each section (section 1a, etc.) is simply overlapped on the semiconductor wafer (substrate 1W). Since the external magnetic field H having a component orthogonal to the flat surface can be applied, the work of the ordered heat treatment process can be simplified.

Furthermore, in the ordered heat treatment process according to the first embodiment, one first magnet 20N shares four apex P2 adjacent to one vertex P2 of one rectangular section (such as the section 1a). So that one second magnet 20S faces the four adjacent second regions AS sharing the other vertex P1 located diagonally to the vertex P1 in the section 1a. It is arranged in.
Thereby, since a single permanent magnet (1st magnet 20N, 2nd magnet 20S) can apply an external magnetic field to each of four divisions which share one vertex and adjoin, it is a fixed permanent magnet The partition size can be efficiently reduced with respect to the size and the arrangement pitch.

Furthermore, in the film forming step according to the first embodiment, the pinned layer is in contact with the flat surface along the first direction (± X direction) in the in-plane direction of the flat surface of the semiconductor wafer (substrate 1W). The first inclined surface (inclined surface 10a, 10b) provided on the second inclined surface (inclined surface) provided in contact with the flat surface along a second orientation (± Y direction) different from the first orientation. 10c, 10d).
Thus, in the magnetic sensor 1, a plurality of magnetoresistive elements having different sensitivity directions (directions in which the intensity of the external magnetic field can be mainly observed) are formed in the in-plane direction of the flat surface. It becomes possible to measure for each component of the direction.

  As mentioned above, according to the manufacturing method of the magnetic sensor which concerns on 1st Embodiment, size reduction of a magnetic sensor is realizable.

<Other variations>
In addition, the manufacturing method of the magnetic sensor 1 according to the first embodiment is not limited to the above-described aspect, and can be modified as follows as an example.

FIG. 13 is a diagram for explaining the outline of the ordered heat treatment process according to the modification of the first embodiment.
In the regularization heat treatment process of the magnetic sensor 1 according to the first embodiment, the magnet array 20 has been described as being disposed so as to overlap one side (back side) of the substrate 1W (see FIG. 4). However, in the ordered heat treatment process according to another embodiment, for example, as shown in FIG. 13A, another magnet array 40 is also arranged on the other side (front side) of the substrate 1W. Also good. At this time, each permanent magnet (first magnet 20N, second magnet 20S) constituting the magnet array 20 and each permanent magnet (first magnet 40N, second magnet 40S) constituting the magnet array 40 are respectively It is assumed that the opposing polar surfaces have different polarities (see FIG. 13A).
With such a configuration, among the directional components of the external magnetic field H, the component orthogonal to the flat surface is stronger than the other directional components, so the magnetization orientation of the pinned layer 30b (FIG. 3) to be fixed Can improve the accuracy.

  Note that the same effect as in the case of FIG. 13A can also be obtained by arranging the yoke 50 shown in FIG. 13B instead of the magnet array 40. Here, the yoke 50 is made of a soft magnetic material such as iron, for example. Specifically, the yoke 50, which is a soft magnetic material, faces each of the first magnet 20N and the second magnet 20S of the magnet array 20, so that the facing portions have a polarity opposite to the facing polarity. Change. Thereby, the substrate 1W is substantially equivalent to a state of being sandwiched between the magnet array 20 and the magnet array 40 as shown in FIG. Therefore, it is possible to apply the external magnetic field H mainly including a component orthogonal to the flat surface of the substrate 1W, and to improve the accuracy of the magnetization direction of the pinned layer 30b (FIG. 3) to be fixed.

  As described above, by arranging the magnetic body so as to sandwich each of the first magnet 20N and the second magnet 20S of the magnet array 20 and the flat surface of the substrate 1W, components other than components orthogonal to the flat surface of the substrate 1W can be obtained. An external magnetic field in which other direction components are excluded can be applied. Therefore, the accuracy of the magnetization orientation of the pinned layer 30b (FIG. 3) to be fixed can be further improved.

  Further, the arrangement of the magnet array 20 shown in FIG. 5 is an example, and the arrangement is not limited to this. The magnet array 20 is arranged so that an external magnetic field having a component (± Z direction component) orthogonal to the flat surface can be applied. Any arrangement may be used. However, in this case, the pinned layer constituting the magnetoresistive effect element is arranged to be inclined with respect to the flat surface so that the direction of magnetization is fixed based on a component orthogonal to the flat surface.

In the first embodiment, the bridge circuit is configured by combining magnetoresistive elements having different magnetization directions. However, in the magnetic sensor according to another embodiment, the bridge circuit is not necessarily configured. Not necessary. For example, a bridge circuit may be configured by replacing some of the four sets of magnetoresistive effect elements constituting each bridge circuit BX1, BX2, BY1, BY2 (FIG. 10) with resistance elements having known resistance values. Good.
By doing in this way, since the number of the magnetoresistive effect elements which comprise the magnetic sensor 1 can be reduced, size reduction can be promoted further.

  Further, for the first magnet 20N, the phrase “one polar surface (N-polar surface) is opposed to the first region AN” means that the one polar surface faces the magnetoresistive elements X1A to X1A of the substrate 1W. Both the case where it opposes from the flat surface side in which Y2D is formed, and the case where it opposes from the back surface side different from the said flat surface of the board | substrate 1W are included. The same applies to the second magnet 20 </ b> S, “the other polar surface (surface of S pole) is opposed to the second region AS”.

  The magnetic field intensity calculation unit according to the first embodiment records a program for realizing the function on a computer-readable recording medium, and causes the computer system to read the program recorded on the recording medium, It may be an aspect realized by executing. The “computer system” here includes an OS and hardware such as peripheral devices. The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. In addition, a volatile memory (RAM) that holds a program for a certain period of time is also included.

  As mentioned above, although some embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the invention described in the claims and equivalents thereof, as long as they are included in the scope and gist of the invention.

  DESCRIPTION OF SYMBOLS 1 ... Magnetic sensor, 1W ... Board | substrate (semiconductor wafer), 1a ... division, 10 ... bank part, 10a, 10b, 10c, 10d ... inclined surface, 20, 40 ... magnet array, 20N, 40N ... 1st magnet, 20S, 40S ... second magnet, 30a ... pinning layer, 30b ... pinned layer, 30c ... spacer layer, 30d ... free layer, 31a, 31b ... wiring layer, 50 ... yoke, X1A, X1B, X1C, X1D, X2A, X2B, X2C , X2D, Y1A, Y1B, Y1C, Y1D, Y2A, Y2B, Y2C, Y2D ... magnetoresistive effect element, BX1, BX2, BY1, BY2 ... bridge circuit

Claims (8)

A film forming step of forming a multilayer film including at least a pinned layer on the inclined surface provided on the flat surface of the substrate by forming a magnetoresistive effect element;
Applying an external magnetic field having a component orthogonal to the flat surface of the substrate and fixing the magnetization direction of the pinned layer based on the orthogonal component; and
The manufacturing method of the magnetic sensor which has this. In the magnetizing step,
An external magnetic field in one direction orthogonal to the flat surface is applied to a predetermined first region included in one section of the flat surface of the substrate, and the predetermined region included in the section includes the first region. 2. The method of manufacturing a magnetic sensor according to claim 1, wherein in a second region different from the region, an external magnetic field that is perpendicular to the flat surface and opposite to the one orientation is applied. In the magnetizing step,
A first magnet that faces one polar surface to the first region and a second magnet that faces another polar surface to the second region are arranged on the same plane, and the external magnetic field is The magnetic sensor manufacturing method according to claim 2, wherein the magnetic sensor is applied. In the magnetizing step,
One of the first magnets is arranged so as to face one of the four adjacent first regions while sharing one vertex of the rectangular section, and one of the second magnets The method of manufacturing a magnetic sensor according to claim 3, wherein the other vertexes located opposite to each other of the one vertex are shared so as to face the four adjacent second regions. . In the magnetizing step,
5. The method of manufacturing a magnetic sensor according to claim 3, wherein a magnetic body is disposed so as to sandwich the flat surface of the substrate with each of the first magnet and the second magnet. In the film forming step,
The pinned layer includes a first inclined surface provided in contact with the flat surface along a first orientation in an in-plane direction of the flat surface, and the flat surface along a second orientation different from the first orientation. 5. The method of manufacturing a magnetic sensor according to claim 2, wherein the film is formed on both of the second inclined surface provided in contact with the second inclined surface. A rectangular plate-shaped body,
A first magnetic field including at least a pinned layer and formed on a slant surface of a first slant surface provided along a first direction in an in-plane direction of the flat surface of the main body with the first direction as a longitudinal direction. A resistance effect element;
On the inclined surface of the second inclined surface that includes at least a pinned layer and is provided along a second orientation different from the first orientation, in the in-plane direction of the flat surface of the main body portion. A second magnetoresistive element formed as a longitudinal direction,
With
A first region defined by two points on each side of one vertex of the main body part and two sides that are in contact with the one vertex, and another vertex located on a diagonal of the one vertex and the other Each of the first magnetoresistive effect element and the second magnetoresistive effect element is arranged in each of the second regions partitioned by two points on each of the two sides that contact each other at the apex. Magnetic sensor. The first magnetoresistive element and the second magnetoresistive element arranged in the first region have a component in which the magnetization direction of the pinned layer faces at least one direction orthogonal to the flat surface. ,
The first magnetoresistive element and the second magnetoresistive element arranged in the second region have a component in which the magnetization direction of the pinned layer faces at least another direction orthogonal to the flat surface. The magnetic sensor according to claim 7.

Images