JP2021152479A - Magnetic sensor and manufacturing method thereof - Google Patents

Abstract

To apply a magnetic bias to a magnetoresistive effect element without segmenting the magnetoresistive effect element.SOLUTION: A magnetic sensor 10 comprises: magnetoresistive effect elements R1-R4 extending in a y direction, with an x direction defined to be a fixed magnetization direction; and a magnetization direction control film 55 laminated on the magnetoresistive effect elements R1-R4 for giving a magnetic bias to the magnetoresistive effect elements R1-R4 in the x direction. Since the magnetization direction control film 55 for giving the magnetic bias to the magnetoresistive effect elements R1-R4 is laminated on the magnetoresistive effect elements R1-R4, the magnetoresistive effect elements R1-R4 are not needed to be segmented by a plurality of hard magnetic materials. Thereby, irregular noises superimposed on a detection signal can be reduced while an increase of noise density is suppressed.SELECTED DRAWING: Figure 5

Description

The present invention relates to a magnetic sensor and a method for manufacturing the same, and more particularly to a magnetic sensor for detecting an extremely weak magnetic field and a method for manufacturing the same.

As a magnetic sensor, as described in Patent Document 1, a type of magnetic sensor that detects the direction and strength of a magnetic field based on a change in the resistance value of a magnetoresistive element is known. The magnetic sensor described in Patent Document 1 secures a sufficient resistance value by bending the magnetoresistive element in a meander shape, and arranges a plurality of hard magnetic materials (magnets) that divide the magnetoresistive element. A magnetic bias is applied to the magnetoresistive sensor. If a magnetic bias is applied to the magnetoresistive element, the magnetoresistive element is ideally made into a single magnetic domain, so that irregular noise superimposed on the detection signal can be reduced.

Japanese Patent No. 50666579

However, in the magnetic sensor described in Patent Document 1, since the magnetoresistive element is divided in the longitudinal direction by a plurality of hard magnetic materials, the length of the magnetoresistive element is shortened by that amount. When the length of the magnetoresistive element is shortened, there is a problem that the noise density proportional to the square root of the area of the magnetoresistive element increases.

Therefore, an object of the present invention is to provide a magnetic sensor capable of applying a magnetic bias to a magnetoresistive element without dividing the magnetoresistive element, and a method for manufacturing the same.

The magnetic sensor according to the present invention is laminated with a magnetic resistance effect element extending in a first direction and having a second direction intersecting the first direction as a fixed magnetization direction, and a magnetic resistance effect. It is characterized by including a magnetization direction control layer that gives the element a magnetic bias in the first direction.

According to the present invention, since the magnetization direction control layer that gives a magnetic bias to the magnetoresistive sensor is laminated on the magnetoresistive element, it is not necessary to divide the magnetoresistive element by a plurality of hard magnetic materials. This makes it possible to reduce irregular noise superimposed on the detection signal while suppressing an increase in noise density.

In the present invention, the magnetic resistance effect element includes an antiferromagnetic layer, a magnetized fixed layer laminated on the antiferromagnetic layer, and a magnetized sensitive layer laminated on the magnetized fixed layer via a non-magnetic layer, and magnetizes. The direction control layer may be laminated on the magnetically sensitive layer. According to this, it is possible to give a sufficient magnetic bias to the magnetically sensitive layer. In this case, the magnetization direction control layer may be made of the same magnetic material as the antiferromagnetic layer and may have a different thickness from the antiferromagnetic layer. According to this, it is possible to magnetize the fixed magnetization directions of the antiferromagnetic layer and the magnetization direction control layer in different directions while reducing the manufacturing cost. Further, in this case, the magnetization direction control layer may be thinner than the antiferromagnetic layer. According to this, the antiferromagnetic layer can be magnetized more strongly than the magnetization direction control layer.

The magnetic sensor according to the present invention may further include a non-magnetic bias adjusting layer provided between the magnetoresistive element and the magnetization direction control layer. According to this, the magnetic bias can be adjusted by the film thickness of the bias adjusting layer. In this case, the magnetoresistive layer incompletely covers the magnetoresistive element, whereby the magnetization direction control layer passes through the first region covering the magnetoresistive element via the bias adjustment layer and the bias adjustment layer. It may include a second region covering the magnetoresistive element without fail. According to this, the magnetic bias can be finely adjusted by the area ratio of the first region and the second region.

The magnetic sensor according to the present invention has an insulating layer that covers the magnetoresistive sensor and the magnetization direction control layer, and a second arrangement that is provided on the insulating layer and is arranged in a second direction via a magnetic gap that overlaps with the magnetoresistive element. It may further include the first and second ferromagnetic layers. According to this, the detection magnetic field can be effectively applied to the magnetoresistive element in the second direction. In this case, at least one of the first and second ferromagnetic layers may have an overlap with the magnetoresistive element via the insulating layer. According to this, the detection magnetic field can be applied more effectively to the magnetoresistive element.

In the present invention, the magnetic resistance effect element includes the first and second magnetic resistance effect elements, and the magnetization direction control layer is the first and second magnetization laminated on the first and second magnetic resistance effect elements, respectively. The direction control layer is included, the first magnetic resistance effect element and the second magnetic resistance effect element are bridge-connected, and the directions of the magnetic bias applied to the first and second magnetic resistance effect elements are the same as each other. Yes, the directions of the currents flowing through the first and second magnetic resistance effect elements may be the same as each other. According to this, the relationship between the direction of the magnetic bias and the direction in which the current flows becomes constant. As a result, irregular noise is significantly reduced, so that an extremely weak magnetic field can be detected.

The method for manufacturing a magnetic sensor according to the present invention includes a film forming step of laminating a magnetization direction control film made of a magnetoresistive element and an anti-ferrometric material, and annealing at a first temperature while applying a magnetic field in a second direction. As a result, the first annealing step of orienting the fixed magnetization direction of the magnetoresistive sensor in the second direction is different from the first temperature while applying a magnetic field in the first direction intersecting the second direction. It is characterized by comprising a second annealing step of magnetizing the magnetization direction control film in the first direction by annealing at the second temperature.

According to the present invention, the magnetoresistive element and the magnetization direction control film can be magnetized in different directions.

In the film forming process, the antiferromagnetic layer, the magnetization fixing layer, the non-magnetic film and the magnetization fixing layer are formed in this order to form a magnetic resistance effect element, and then the magnetic material is the same as that of the antiferromagnetic layer. Moreover, the magnetization direction control film having a thickness thinner than the antiferromagnetic layer may be formed, and the second annealing temperature may be lower than the first annealing temperature. According to this, the antiferromagnetic layer can be magnetized more strongly than the magnetization direction control film.

As described above, according to the present invention, it is possible to apply a magnetic bias to the magnetoresistive element without dividing the magnetoresistive element. This makes it possible to reduce irregular noise superimposed on the detection signal while suppressing an increase in noise density.

FIG. 1 is a schematic perspective view showing the appearance of the magnetic sensor 10 according to a preferred embodiment of the present invention. FIG. 2 is a schematic plan view for explaining the structure of the sensor chip 20 on the element forming surface 21. FIG. 3 is a schematic cross-sectional view taken along the line AA shown in FIG. FIG. 4 is a circuit diagram for explaining the connection relationship between the magnetoresistive elements R1 to R4. FIG. 5 is a schematic cross-sectional view for explaining a first example of the layer structure of the magnetoresistive elements R1 to R4. FIG. 6 is a schematic cross-sectional view for explaining a second example of the layer structure of the magnetoresistive elements R1 to R4. FIG. 7 is a graph showing the relationship between the film thickness of the bias adjusting film 57 and the anisotropic magnetic field (Hk) of the magnetically sensitive layer 54. FIG. 8 is a schematic plan view showing a state in which the bias adjusting film 57 is an incomplete film.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic perspective view showing the appearance of the magnetic sensor 10 according to a preferred embodiment of the present invention.

As shown in FIG. 1, the magnetic sensor 10 according to the present embodiment includes a substrate 2 whose surface constitutes an xz surface, a sensor chip 20 mounted on the surface of the substrate 2, and magnetic collectors 30 to 32. .. The sensor chip 20 has an element forming surface 21 forming an xy surface, and one end of the magnetic collector 30 in the z direction and the element forming surface 21 face each other. The magnetic collectors 31 and 32 are provided on the back surface side of the sensor chip 20. The magnetic collectors 30 to 32 are blocks made of a soft magnetic material having a high magnetic permeability such as ferrite.

As shown in FIG. 1, in the present embodiment, the sensor chip 20 is mounted so that the element forming surface 21 of the sensor chip 20 is perpendicular to the surface of the substrate 2. That is, the sensor chip 20 is mounted in a state of being laid 90 ° with respect to the substrate 2. Therefore, even when the length of the magnetic collector 30 in the z direction is long, the magnetic collector 30 can be stably fixed to the substrate 2.

FIG. 2 is a schematic plan view for explaining the structure of the sensor chip 20 on the element forming surface 21. Further, FIG. 3 is a schematic cross-sectional view taken along the line AA shown in FIG.

As shown in FIGS. 2 and 3, four magnetoresistive elements R1 to R4 extending in the y direction and three ferromagnetic films M1 to M3 are provided on the element forming surface 21 of the sensor chip 20. ing. The fixed magnetization directions of the magnetoresistive elements R1 to R4 are all aligned in the x direction (+ x direction or −x direction). Further, as will be described later, a magnetic bias in the y direction (+ y direction or −y direction) is applied to all of the magnetoresistive effect elements R1 to R4.

The magnetoresistive elements R1 to R4 are formed on the surface of the sensor substrate 22 that constitutes the element forming surface 21. As the material of the sensor substrate 22, silicon or alumina titanium carbide (ALTIC) can be used. The magnetoresistive elements R1 to R4 are _{covered with an insulating film 23 made of Al 2} O ₃ or the like, and the ferromagnetic films M1 to M3 are formed on the insulating film 23. The ferromagnetic films M1 to M3 are made of a soft magnetic film having a high magnetic permeability such as permalloy. The ferromagnetic films M1 to M3 may be a ferromagnetic layer in which a plurality of films are laminated. The ferromagnetic films M1 to M3 are _{covered with an insulating film 24 made of Al 2} O ₃ or the like, and the magnetic collector 30 is arranged on the insulating film 24. The insulating film 24 may be an insulating layer in which a plurality of films are laminated. FIG. 2 also shows the planar position of the magnetic collector 30 on the element forming surface 21.

The ferromagnetic films M1 to M3 form magnetic gaps G1 to G4 extending in the y direction, so that the magnetoresistive elements R1 to R4 overlap with the magnetic gaps G1 to G4 in a plan view from the z direction, respectively. Is placed in. Although not particularly limited, in the present embodiment, the width Gx of the magnetic gaps G1 to G4 in the x direction is narrower than the width Rx of the magnetic resistance effect elements R1 to R4 in the x direction, and therefore, in the z direction. The ferromagnetic film M1 has an overlap with the magnetic resistance effect elements R1 to R4, the ferromagnetic film M2 has an overlap with the magnetic resistance effect elements R1 and R3, and the ferromagnetic film M3 has an overlap with the magnetic resistance effect element R2. , R4 overlaps. As a result, the detection magnetic field from the ferromagnetic film M1 to the ferromagnetic films M2 and M3 or the detection magnetic field from the ferromagnetic films M2 and M3 toward the ferromagnetic film M1 is in the x direction with respect to the magnetic resistance effect elements R1 to R4. Is applied to.

FIG. 4 is a circuit diagram for explaining the connection relationship between the magnetoresistive elements R1 to R4.

As shown in FIG. 4, the magnetoresistive element R1 is connected between the terminal electrodes 41 and 42, the magnetoresistive element R2 is connected between the terminal electrodes 41 and 43, and the magnetoresistive element R3 is connected between the terminal electrodes 43 and 44. The magnetoresistive element R4 is connected between the terminal electrodes 42 and 44. A power supply potential Vcc is given to the terminal electrode 41, and a ground potential GND is given to the terminal electrode 44. Therefore, a current flows through the magnetoresistive elements R1 to R4 in the directions indicated by arrows I11 to I14, respectively. That is, currents flow in the magnetoresistive elements R1 to R4 in the same direction.

As described above, the magnetoresistive elements R1 to R4 all have the same magnetization fixing direction. Therefore, when the magnetic flux collected by the magnetic collector 30 is applied to the magnetoresistive elements R1 to R4, the magnetoresistive elements R1 and R3 located on one side (−x direction side) of the magnetoresistive body 30. There is a difference between the amount of change in resistance and the amount of change in resistance of the magnetoresistive effect elements R2 and R4 located on the other side (+ x direction side) of the magnetic collector 30. Since the magnetoresistive elements R1 to R4 form a differential bridge circuit, changes in the electrical resistance of the magnetoresistive elements R1 to R4 according to the magnetic flux density appear on the terminal electrodes 42 and 44. ..

The differential signals output from the terminal electrodes 42 and 43 are input to the substrate 2 or the differential amplifier 47 provided outside the substrate 2. The output signal of the differential amplifier 47 is fed back to the terminal electrode 45. As shown in FIG. 4, a compensation coil C is connected between the terminal electrode 45 and the terminal electrode 46, whereby the compensation coil C generates a canceling magnetic field corresponding to the output signal of the differential amplifier 47. .. The compensation coil C can be integrated on the sensor chip 20.

The compensation coil C has a section C1 extending in the y direction along the magnetoresistive sensor R1, a section C2 extending in the y direction along the magnetoresistive element R2, and y along the magnetoresistive element R3. A section C3 extending in the direction and a section C4 extending in the y direction along the magnetoresistive sensor R4 are included. Then, when a current is passed from the terminal electrode 45 toward the terminal electrode 46, a current flows in the sections C1 to C4 in the directions indicated by arrows I21 to I24, respectively. That is, currents flow in the sections C1 and C3 and the sections C2 and C4 in opposite directions. This makes it possible for the compensation coil C to cancel the detection magnetic fields applied to the magnetoresistive elements R1 and R3 and the magnetoresistive elements R2 and R4 in opposite directions. Then, if the current output from the differential amplifier 47 is converted into current and voltage by the detection circuit 48, the strength of the external magnetic flux can be detected.

FIG. 5 is a schematic cross-sectional view for explaining the layer structure of the magnetoresistive elements R1 to R4.

In the first example shown in FIG. 5, on the surface of the sensor substrate 22 constituting the element forming surface 21, the buffer layer 50, the antiferromagnetic layer 51, the magnetization fixing layer 52, the non-magnetic layer 53, the magnetic sensitive layer 54, The magnetization direction control film 55 and the protective layer 56 are laminated in this order. Of these, the antiferromagnetic layer 51, the magnetization fixing layer 52, the non-magnetic layer 53, and the magnetically sensitive layer 54 constitute the magnetoresistive effect elements R1 to R4.

The buffer layer 50 is made of, for example, a NiCr film having a thickness of about 50 angstroms. The antiferromagnetic layer 51 is made of, for example, an IrMn film having a thickness of about 70 angstroms. The magnetization fixing layer 52 has a structure in which, for example, CoFe films 52A and 52C having a thickness of about 15 angstroms are sandwiched between Ru films 52B having a thickness of about 8 angstroms. The non-magnetic layer 53 is made of, for example, a Cu film of about 20 angstroms. The magnetic sensitive layer 54 is composed of, for example, a laminated film of a CoFe film 54A having a size of about 10 angstroms and a NiFe film 54B having a size of about 70 angstroms. The magnetization direction control film 55 is made of, for example, an IrMn film having a thickness of about 50 angstroms. The protective layer 56 is made of, for example, Ru, Ta or a laminated film thereof.

As used herein, the term "layer" means a film made of a single material or a laminated body of a plurality of films made of different materials, which collectively realizes one function. Therefore, the magnetization direction control film 55 may be a magnetization direction control layer in which a plurality of films are laminated.

Here, the antiferromagnetic layer 51 is magnetized in the x direction, so that the fixed magnetization direction of the magnetized fixed layer 52 is the x direction. On the other hand, the magnetization direction control film 55 is magnetized in the y direction, whereby a magnetic bias in the y direction is applied to the magnetic sensitive layer 54. Here, as a method of magnetizing the antiferromagnetic layer 51 and the magnetization direction control film 55 in different directions, the antiferromagnetic layer is formed after the buffer layer 50 to the protective layer 56 are formed by using a sputtering method or the like. Examples thereof include a method of separately performing an annealing step of magnetizing 51 in the x direction and an annealing step of magnetizing the magnetization direction control film 55 in the y direction. Here, even when the antiferromagnetic layer 51 and the magnetization direction control film 55 are made of the same antiferromagnetic material, if the film thicknesses of the antiferromagnetic layer 51 and the magnetization direction control film 55 are different from each other, the orientation of the soft magnetic material films adjacent to them is broken. temperature (blocking temperature: T _B) is different, it is possible to magnetized in different directions the magnetization direction control film 55 and the antiferromagnetic layer 51 by two annealing steps each other.

As an example, as described above, when the antiferromagnetic layer 51 is made of an IrMn film having a thickness of about 70 angstrom and the magnetization direction control film 55 is made of an IrMn film having a thickness of about 50 angstrom, while applying a magnetic field in the x direction. The antiferromagnetic layer 51 and the magnetization direction control film 55 are magnetized in the x direction by annealing at about 280 ° C., and then the magnetization direction control film is annealed at about 240 ° C. while applying a magnetic field in the y direction. The magnetization direction of 55 is changed in the y direction. In the second annealing step, the magnetization direction of the thick antiferromagnetic layer 51 does not change and is maintained in the x direction. As described above, if the antiferromagnetic layer 51 and the magnetization direction control film 55 are made of the same antiferromagnetic material, the manufacturing cost can be reduced. Further, by making the thickness of the magnetization direction control film 55 thinner than the thickness of the antiferromagnetic layer 51, the magnetic bias in the y direction becomes weaker than the fixed magnetization component in the x direction applied to the magnetic sensitive layer 54. Therefore, it is possible to prevent a decrease in detection sensitivity due to an excessive magnetic bias.

Alternatively, the antiferromagnetic layer 51 and the magnetization direction control film 55 may be made of different directional antiferromagnetic materials. According to this, even if the film thicknesses of both are the same, they can be magnetized in different directions due to the difference in blocking temperature. The antiferromagnetic material which can be used for the antiferromagnetic layer 51 and the magnetization direction control film _{55, IrMn (T B = 280} ℃), NiMn (T B = 375 ℃), PtMn (T B = 340 ℃) _{, α-Fe 2 O 3 (} T B = 320 ℃), PtPdMn (T B = 300 ℃), CrMnPt (T B = 280 ℃), RuRhMn (T B = 225 ℃), NiO (T B = 210 ℃) , like _{FeMn (T B = 180 ℃)} . Above the blocking temperature T _B varies with the film thickness.

The strength of the magnetic bias applied to the magnetically sensitive layer 54 by the magnetization direction control film 55 can be adjusted by the type and film thickness of the antiferromagnetic material constituting the magnetization direction control film 55. Further, as shown in FIG. 6, the magnetic bias applied to the magnetically sensitive layer 54 may be adjusted by providing a non-magnetic bias adjusting film 57 between the magnetically sensitive layer 54 and the magnetization direction control film 55. No. As the material of the bias adjusting film 57, for example, Ru can be used. The bias adjusting film 57 may be a bias adjusting layer in which a plurality of films are laminated.

FIG. 7 is a graph showing the relationship between the film thickness of the bias adjusting film 57 and the anisotropic magnetic field (Hk) of the magnetically sensitive layer 54. The anisotropic magnetic field is the strength of the magnetic field required when trying to align the magnetization directions in a certain direction. Therefore, the larger the anisotropic magnetic field, the stronger the magnetic bias by the magnetization direction control film 55, and the lower the magnetic field sensitivity of the magnetic sensitive layer 54.

As shown in FIG. 7, the anisotropic magnetic field of the magnetic sensitive layer 54 in the absence of the magnetization direction control film 55 is about 4 Oe. On the other hand, by providing the magnetization direction control film 55 made of IrMn having a thickness of 50 angstroms, the anisotropic magnetic field of the magnetic sensitive layer 54 increases to about 67 Oe. When the bias adjusting film 57 is provided between the magnetic sensing layer 54 and the magnetization direction control film 55, the anisotropic magnetic field of the magnetic sensing layer 54 decreases as the film thickness of the bias adjusting film 57 increases, and the film thickness increases. At 5 angstroms, the anisotropic magnetic field of the magnetically sensitive layer 54 drops to about 7 Oe. As described above, the magnetic field sensitivity of the magnetic sensitive layer 54 can be adjusted by the film thickness of the bias adjusting film 57.

The bias adjusting film 57 does not have to be a complete film covering the entire surface of the magnetic sensitive layer 54, and is a partial film that completely covers the magnetic sensitive layer 54 as shown in FIG. 8 which is a schematic plan view. It doesn't matter. When the bias adjusting film 57 is an incomplete film, the magnetization direction control film 55 includes a region covering the magnetic sensitive layer 54 via the bias adjusting film 57 and a magnetic sensitive layer 54 without passing through the bias adjusting film 57. There is an area to cover. Therefore, the magnetic bias applied to the magnetically sensitive layer 54 can be adjusted by the ratio of these regions. The incomplete bias adjusting film 57 can be formed by adjusting film forming conditions such as sputtering conditions.

As described above, since the magnetic sensor 10 according to the present embodiment includes the magnetization direction control film 55 that applies a magnetic bias in the y direction to the magnetoresistive effect elements R1 to R4 having the x direction as the magnetization fixing direction. It is possible to reduce irregular noise superimposed on the detection signal. Moreover, since the magnetization direction control film 55 is formed on both sides of the magnetoresistive elements R1 to R4 without dividing them, the noise density increases in proportion to the square root of the area of the magnetoresistive elements R1 to R4. It is also possible to prevent. Further, in the magnetic sensor 10 according to the present embodiment, since the relationship between the direction of the current and the direction of the magnetic bias is constant in all the magnetoresistive elements R1 to R4, the effect of reducing irregular noise is very large. This makes it possible to detect an extremely weak magnetic field.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the gist of the present invention, and these are also the present invention. Needless to say, it is included in the range.

2 Substrate 10 Magnetic sensor 20 Sensor chip 21 Element forming surface 22 Sensor substrate 23,24 Insulation film 30 to 32 Magnetizer 31,32 Magnetizer 41-63 Terminal electrode 47 Differential amplifier 48 Detection circuit 50 Buffer layer 51 Anti-ferrospheric layer 52 Magnetized fixed layer 52A, 52C CoFe film 52B Ru film 53 Non-magnetic layer 54 Magnetically sensitive layer 54A CoFe film 54B NiFe film 55 Magnetization direction control film 56 Protective layer 57 Bias adjustment film C Compensation coil C1 to C4 Section G1 to G4 Magnetic gap I11 to I14, I21 to I24 Current direction M1 to M3 Magnetic film R1 to R4 Magnetic resistance effect element

Claims (11)

A magnetoresistive element extending in the first direction and having a second direction intersecting the first direction as a fixed magnetization direction.
A magnetic sensor including a magnetization direction control layer that is laminated on the magnetoresistive sensor and imparts a magnetic bias in the first direction to the magnetoresistive element. The magnetoresistive sensor includes an antiferromagnetic layer, a magnetization-fixing layer laminated on the antiferromagnetic layer, and a magnetic-sensitive layer laminated on the magnetization-fixing layer via a non-magnetic layer.
The magnetic sensor according to claim 1, wherein the magnetization direction control layer is laminated on the magnetosensitive layer. The magnetic sensor according to claim 2, wherein the magnetization direction control layer is made of the same magnetic material as the antiferromagnetic layer and has a thickness different from that of the antiferromagnetic layer. The magnetic sensor according to claim 3, wherein the magnetization direction control layer is thinner than the antiferromagnetic layer. The magnetic sensor according to any one of claims 1 to 4, further comprising a non-magnetic bias adjusting layer provided between the magnetoresistive element and the magnetization direction control layer. The bias adjusting layer incompletely covers the magnetoresistive element, whereby the magnetization direction control layer has a first region covering the magnetoresistive element via the bias adjusting layer and the bias adjusting. The magnetic sensor according to claim 5, further comprising a second region covering the magnetoresistive element without interposing a layer. An insulating layer covering the magnetoresistive element and the magnetization direction control layer,
A claim characterized by further comprising first and second ferromagnetic layers provided on the insulating layer and arranged in the second direction via a magnetic gap overlapping the magnetoresistive element. Item 6. The magnetic sensor according to any one of Items 1 to 6. The magnetic sensor according to claim 7, wherein at least one of the first and second ferromagnetic layers has an overlap with the magnetoresistive element via the insulating layer. The magnetoresistive element includes first and second magnetoresistive elements.
The magnetization direction control layer includes first and second magnetization direction control layers laminated on the first and second magnetoresistive elements, respectively.
The first magnetoresistive element and the second magnetoresistive element are bridge-connected.
The directions of the magnetic bias applied to the first and second magnetoresistive elements are the same as each other.
The magnetic sensor according to any one of claims 1 to 8, wherein the directions of the currents flowing through the first and second magnetoresistive elements are the same as each other. A film formation process in which a magnetoresistive element and a magnetization direction control film made of an antiferromagnetic material are laminated.
A first annealing step of orienting the fixed magnetization direction of the magnetoresistive element in the second direction by annealing at a first temperature while applying a magnetic field in the second direction.
The magnetization direction control film is magnetized in the first direction by annealing at a second temperature different from the first temperature while applying a magnetic field in the first direction intersecting the second direction. A method for manufacturing a magnetic sensor, which comprises a second annealing step. In the film forming step, the antiferromagnetic layer, the magnetization fixing layer, the non-magnetic film and the magnetization fixing layer are formed in this order to form the magnetic resistance effect element, and then the same magnetic material as the antiferromagnetic layer is formed. The magnetization direction control film is formed and is thinner than the antiferromagnetic layer.
The method for manufacturing a magnetic sensor according to claim 10, wherein the second annealing temperature is lower than the first annealing temperature.

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