Method for manufacturing magnetic laminates and magnetic sensors, and apparatus for manufacturing magnetic laminates

Abstract

The apparatus for magnetizing the magnetized fixed layer and heating the antiferromagnetic layer is simplified. [Solution] A laminated film 601 is formed having a ferromagnetic layer 631 and an antiferromagnetic layer 66, with the ferromagnetic layer 631 and the antiferromagnetic layer 66 in contact with each other in a first direction Z (Step S1). Next, a magnetic field in the first direction Z is applied to the laminated film 601 to create a magnetization-fixed layer 63 from the ferromagnetic layer 631, in which the magnetization direction is fixed with respect to the external magnetic field (Step S2). After stopping the application of the magnetic field, the laminated film 601 is heated to a temperature above the blocking temperature of the antiferromagnetic layer 66 to create a magnetic laminate 6 (Step S3).

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a magnetic laminate and a magnetic sensor, and an apparatus for manufacturing a magnetic laminate.

Background Art

[0002] Patent Document 1 describes a magnetic sensor having a magnetization free layer whose magnetization direction changes with respect to an external magnetic field, a magnetization fixed layer whose magnetization direction is fixed with respect to an external magnetic field, and a nonmagnetic layer located between the magnetization free layer and the magnetization fixed layer. The magnetization direction of the magnetization fixed layer may reverse when it receives a strong magnetic field and remain fixed in the reversed state. To avoid this, as described in Patent Document 2, it is known to provide an antiferromagnetic layer and strongly fix the magnetization direction of the magnetization fixed layer by exchange coupling between the antiferromagnetic layer and the magnetization fixed layer.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] The magnetization fixed layer requires magnetization, and the antiferromagnetic layer needs to be heated at a temperature above the blocking temperature in order to obtain exchange coupling. In the magnetic sensor described in Patent Document 1, the magnetization direction of the magnetization fixed layer is oriented in the stacking direction of the magnetization free layer, the nonmagnetic layer, and the magnetization fixed layer. Therefore, it is necessary to perform magnetization of the magnetization fixed layer and heating of the antiferromagnetic layer from the same direction. However, since magnetization and heating are performed in the same process, the apparatus for magnetization and heating becomes complicated.

[0005] The present disclosure aims to provide a method for manufacturing a magnetic laminate that simplifies the apparatus for magnetizing the magnetized fixed layer and heating the antiferromagnetic layer. [Means for solving the problem]

[0006] The present disclosure is a method for manufacturing a magnetic laminate, comprising: forming a laminate film having a ferromagnetic layer and an antiferromagnetic layer, wherein the ferromagnetic layer and the antiferromagnetic layer are in contact with each other in a first direction; applying a magnetic field in the first direction to the laminate film to create a magnetization-fixed layer from the ferromagnetic layer whose magnetization direction is fixed with respect to an external magnetic field; and after stopping the application of the magnetic field, heating the laminate film to a temperature above the blocking temperature of the antiferromagnetic layer. [Effects of the Invention]

[0007] According to this disclosure, it is possible to provide a method for manufacturing a magnetic laminate that simplifies the apparatus for magnetizing the magnetized fixed layer and heating the antiferromagnetic layer. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic diagram of the magnetic sensor according to the first embodiment. [Figure 2] Figure 1 is a schematic diagram showing the magnetization method for the magnetized fixed layer and the heating method for the laminated film of the magnetic sensor. [Figure 3] Figure 1 is a schematic diagram of the magnetic field application heating device for the magnetic sensor. [Figure 4] This is a schematic diagram of the magnetic sensor according to the second embodiment. [Figure 5] This is a diagram showing the configuration of the laminated film in the second embodiment. [Figure 6] This is a schematic diagram of the magnetic sensor according to the third embodiment. [Figure 7] Figure 6 is a schematic diagram showing the magnetization method for the magnetized fixed layer and the heating method for the laminated film of the magnetic sensor. [Figure 8] This is a schematic diagram of the magnetic sensor according to the fourth embodiment. [Figure 9]Figure 8 is a schematic diagram showing the magnetization method for the magnetized fixed layer and the heating method for the laminated film of the magnetic sensor. [Figure 10] This figure shows the measurement results of the magnetization curves in the examples and comparative examples. [Modes for carrying out the invention]

[0009] Several embodiments of the present disclosure will be described with reference to the drawings. In the following description and drawings, the direction in which the multiple layers of the magnetic laminate 6 and the laminated film 601 are stacked (first direction) is referred to as the Z direction. The direction from the magnetic laminate 6 or laminated film 601 toward the upper electrode layer 5 is referred to as the +Z direction, and the direction from the magnetic laminate 6 or laminated film 601 toward the lower electrode layer 7 or substrate is referred to as the -Z direction, and the first direction means the +Z direction or the -Z direction. The direction perpendicular to the Z direction is referred to as the X direction. For convenience, the X direction is shown in the drawings, but the X direction may be any direction perpendicular to the Z direction. Unless otherwise specified, in the drawings, white arrows indicate the magnetization direction of the first magnetization fixed layer 63 and the second magnetization fixed layer 65, and thick lines with arrows indicate the magnetization direction of the magnetization free layer 61 in the absence of an external magnetic field (hereinafter referred to as the zero magnetic field state).

[0010] (First embodiment) Figure 1(a) shows a schematic configuration of a magnetic sensor 1 according to the first embodiment. The magnetic sensor 1 has a magnetic field sensing element 2. The magnetic field sensing element 2 has a silicon substrate (not shown), a magnetic laminate 6, and upper and lower electrode layers 5 and 7 that supply sense current to the magnetic laminate 6. The upper electrode layer 5, magnetic laminate 6, and lower electrode layer 7 are arranged on the substrate in the -Z direction in the order of upper electrode layer 5, magnetic laminate 6, and lower electrode layer 7. Although not shown, other layers are provided between the lower electrode layer 7 and the substrate, and the lower electrode layer 7 is separated from the substrate. The upper electrode layer 5 and the lower electrode layer 7 can be formed from a laminated film made of a conductor such as Ta, Cu, or Ru.

[0011] The magnetic laminate 6 has a magnetization free layer 61, a non-magnetic layer 62, a first magnetization fixed layer 63, and an antiferromagnetic layer 66. These layers are arranged in the -Z direction from the upper electrode layer 5 toward the lower electrode layer 7 in the order of magnetization free layer 61, non-magnetic layer 62, first magnetization fixed layer 63, and antiferromagnetic layer 66, and adjacent layers are in contact with each other. In other words, the first magnetization fixed layer 63 is a magnetization fixed layer that is in contact with the antiferromagnetic layer 66. These layers may also be stacked in the reverse direction, specifically, they may be arranged in the -Z direction from the upper electrode layer 5 toward the lower electrode layer 7 in the order of antiferromagnetic layer 66, first magnetization fixed layer 63, non-magnetic layer 62, and magnetization free layer 61.

[0012] The magnetization free layer 61 is a magnetic layer whose magnetization direction changes in response to an external magnetic field. The magnetization free layer 61 can be formed from ferromagnetic materials such as Ni, Fe, or Co, alloys consisting of two or more of these, or alloys obtained by adding B or Si to the alloy to make it amorphous. In a zero magnetic field state, the magnetization direction of the magnetization free layer 61 is perpendicular to the Z direction.

[0013] The non-magnetic layer 62 consists of an insulating layer such as MgO or Al2O3, and the magnetic field sensing element 2 in this embodiment operates as a tunnel magnetoresistance effect element (TMR element). The non-magnetic layer 62 may also consist of a non-magnetic metal layer such as copper or silver, in which case the magnetic field sensing element 2 operates as a giant magnetoresistance effect element (GMR element). TMR elements tend to produce higher output than GMR elements.

[0014] The first magnetization fixed layer 63 is a magnetic layer whose magnetization direction is fixed in the Z direction. The first magnetization fixed layer 63 can be formed from a multilayer film of Co and Pt, or from a material with high perpendicular magnetic anisotropy, such as a multilayer film of Co and Pd, or a multilayer film of Co and Ni. In Figure 1(a), the first magnetization fixed layer 63 is magnetized in the +Z direction, but it may also be magnetized in the -Z direction.

[0015] The antiferromagnetic layer 66 can be formed of IrMn, or can also be formed of an antiferromagnetic material such as PtMn or FeRh. The magnetization direction of the first magnetization fixing layer 63 in the zero magnetic field state is stabilized by the antiferromagnetic layer 66. Specifically, the first magnetization fixing layer 63 is exchange-coupled with the antiferromagnetic layer 66 and is fixed in the same direction as the magnetization direction during magnetization and annealing. When a strong Z-direction magnetic field is applied in the direction opposite to the magnetization direction of the first magnetization fixing layer 63, the magnetization direction of the first magnetization fixing layer 63 may be temporarily reversed. If the magnetization direction of the first magnetization fixing layer 63 remains reversed, the slope of the output may be reversed (for example, an upward-right output curve may become a downward-right output curve). However, when the zero magnetic field state is reached, the magnetization direction of the first magnetization fixing layer 63 returns to its original state. Therefore, the magnetization direction of the first magnetization fixing layer 63 in the zero magnetic field state is likely to be stable, and output inversion is also unlikely to occur.

[0016] When an external magnetic field having a Z-direction component is applied to the magnetization free layer 61, the magnetization direction of the magnetization free layer 61 tilts in the Z direction. As a result, the angle formed by the magnetization direction of the magnetization free layer 61 and the magnetization direction of the first magnetization fixing layer 63 changes, and the electrical resistance of the magnetic laminate 6 changes due to the magnetoresistance effect. By detecting the change in the electrical resistance of the magnetic laminate 6, the intensity of the Z-direction component of the external magnetic field can be measured. In this way, the magnetic sensor 1 of the present embodiment detects a magnetic field in the Z direction.

[0017] FIG. 1(b) shows a schematic configuration of a modified example of the magnetic sensor 1 according to the first embodiment. The magnetization direction of the magnetization free layer 61 may form a vortex shape in a plane orthogonal to the Z direction in the zero magnetic field state. The magnetization state of the magnetization free layer 61 in the zero magnetic field state is determined by the balance between the exchange energy and the magnetostatic energy of the magnetization free layer 61. Generally, when the saturation magnetization is large, a vortex shape is likely to occur. In the zero magnetic field state, the center of the vortex, called the core, is located at the center of the magnetization free layer 61, and the magnetization direction draws concentric circles centered on the core. When an external magnetic field in the Z direction is applied, the magnetization direction tilts in the Z direction as a whole, so the same magnetoresistance effect as in the first embodiment can be obtained. In this modified example, since the magnetization free layer 61 forms a vortex shape in the zero magnetic field state, it is easy to suppress fluctuations in sensitivity when receiving a magnetic field other than the Z direction.

[0018] (Method for manufacturing magnetic sensor 1) Next, the method for manufacturing the magnetic sensor 1 of the present embodiment will be described with reference to FIGS. 2 and 3. FIG. 2(a) is a schematic diagram showing a part of the manufacturing process of the magnetic sensor 1 according to the present embodiment, and FIG. 2(b) is a schematic diagram showing a part of the manufacturing process of the magnetic sensor of Comparative Example 1. In FIG. 2, the dashed arrow indicates a magnetic field, and the shaded arrow indicates local heating. Although FIG. 2 shows only one laminated film 601, the magnetic sensor 1 is manufactured in units of a wafer 8 on which a plurality of laminated films 601 are formed. The magnetic sensors of the present embodiment and Comparative Example 1 have the same configuration but different manufacturing processes.

[0019] To manufacture the magnetic sensor 1, first, a lower electrode layer 7, a laminated film 601, and an upper electrode layer 5 are sequentially formed on a wafer 8 (see FIG. 3) which is a substrate (step S1). The laminated film 601 is created by sequentially forming an antiferromagnetic layer 66, a ferromagnetic layer 631, a non-magnetic layer 62, and a magnetization-free layer 61 in the +Z direction on the lower electrode layer 7. The ferromagnetic layer 631 is magnetized to become the first magnetization-fixed layer 63, but since it is not magnetized at this stage, it is used separately from the first magnetization-fixed layer 63. The ferromagnetic layer 631 and the antiferromagnetic layer 66 are in contact with each other in the Z direction. The above steps are common to the present embodiment and Comparative Example 1.

[0020] In this embodiment, the process then involves a magnetization step (step S2) in which a magnetic field is applied to the laminated film 601 to magnetize the ferromagnetic layer 631, and a local heating step (step S3) in which the laminated film 601 is locally heated. Specifically, a magnetic field in the +Z direction (or a magnetic field in the -Z direction) is applied to the laminated film 601 to create a first magnetization-fixed layer 63 from the ferromagnetic layer 631 whose magnetization direction is fixed relative to the external magnetic field, and then the application of the magnetic field is stopped (step S2). After that, the laminated film 601 is heated (annealed) to a temperature above the blocking temperature of the antiferromagnetic layer 66 to create a magnetic laminate 6 (step S3). The blocking temperature is determined by the material of the antiferromagnetic layer 66. By heating the antiferromagnetic layer 66 to a temperature above the blocking temperature of the antiferromagnetic layer 66, exchange coupling occurs between the antiferromagnetic layer 66 and the first magnetization-fixed layer 63. The magnetization process (step S2) and the local heating process (step S3) are not performed simultaneously or in overlapping time, but are performed at completely separate times. Note that the magnetization direction of the free magnetization layer 61 initially tilts in the Z direction in step S2, but in step S3, since no magnetic field is applied, it returns to the X direction, which is the easy magnetization direction.

[0021] Figure 3 shows a schematic configuration of the magnetization heating device 100 used in this embodiment. The magnetization heating device 100 is part of the manufacturing apparatus for the magnetic laminate 6. The magnetization heating device 100 includes a magnetic field application device 101, a heating device 102, and a transfer device 103. The magnetic field application device 101 applies a magnetic field in the Z direction to the laminated film 601 (ferromagnetic layer 631) and creates a first magnetization fixed layer 63 from the ferromagnetic layer 631 whose magnetization direction is fixed with respect to the external magnetic field. The magnetic field application device 101 includes a pair of magnets 104 for applying a magnetic field to the wafer 8 and a wafer 8 holding device (not shown). The pair of magnets 104 can be made of electromagnets or permanent magnets. In Figure 3, the wafer 8 is held vertically between the pair of magnets 104, but the orientation of the pair of magnets 104 and the wafer 8 is not limited to the illustrated configuration. For example, the pair of magnets 104 may be arranged vertically, and the wafer 8 may be held horizontally between the pair of magnets 104.

[0022] The heating device 102 heats the laminated film 601 to a temperature above the blocking temperature of the antiferromagnetic layer 66. The heating device 102 is preferably capable of locally heating the laminated film 601, and preferably includes, for example, a laser beam irradiation device 105 for heating the laminated film 601 with laser light. The heating device 102 includes a stage 106 for holding the wafer 8 in a lateral position, a laser beam irradiation device 105, a reflector 107 for converting the optical path of the laser beam, and an objective lens 108. The stage 106 is driven by a linear guide (not shown) driven by a motor 109 in two orthogonal directions parallel to the wafer holding surface of the stage 106.

[0023] The transfer device 103 transfers the wafer 8 (laminated film 601) between the magnetic field application device 101 and the heating device 102. The transfer device 103 has a base portion 110, a rotating shaft 111 supported by the base portion 110, an arm portion 112 connected approximately perpendicular to the rotating shaft 111, and a wafer holding portion 113 connected to the arm portion 112. The arm portion 112 is rotatable around the rotating shaft 111 and is extendable and retractable in the direction of its major axis 114. The wafer holding portion 113 is rotatable around the major axis 114 of the arm portion 112. As a result, the transfer device 103 can remove the vertically oriented wafer 8 from the magnetic field application device 101, change the orientation of the wafer 8, and place it horizontally on the stage 106 of the heating device 102. The configuration of the transfer device 103 is not limited to this, and for example, a conveyor for transporting the wafer 8 may be used in combination.

[0024] In Comparative Example 1 shown in Figure 2(b), a magnetic laminate 6 is created by applying a magnetic field in the +Z direction to the laminate 601 and heating (annealing) the laminate 601 to a temperature above the blocking temperature of the antiferromagnetic layer 66 (step S12). A first magnetization-fixed layer 63 with a magnetization direction fixed to the external magnetic field is created, and at the same time, exchange coupling occurs between the antiferromagnetic layer 66 and the first magnetization-fixed layer 63. The comparative example has fewer steps and takes less time. However, because the direction of magnetic field application and the heating direction (laser beam irradiation direction) are in the same direction (Z direction), one of the magnets 104 is more likely to interfere with the laser beam irradiation path 115. Specifically, in Figure 3, step S12 of the comparative example can be performed if the pair of magnets 104 are placed at the positions indicated by the dashed lines, but one of the magnets 104 needs to be placed further away from the stage 106 than the optical system such as the reflector 107 and objective lens 108, which increases the distance between the two magnets 104. To magnetize the ferromagnetic layer 631, it is preferable to apply a magnetic field of at least several thousand Oe (several hundred thousand A / m). If the distance between the two magnets 104 increases, the size of the magnets 104 will need to be increased, and in the case of electromagnets, the size of components such as coils will need to be increased, and power consumption will increase.

[0025] Furthermore, in Comparative Example 1, a relatively strong magnetic field is easily applied to the motor 109 used for position control of the stage 106. Since commercially available motors generally use iron (a ferromagnetic material), a strong magnetic field can generate an attractive force on the motor, potentially negatively affecting the positional accuracy of the laser beam irradiation. Motors that do not use iron are not practical. It is conceivable to place a perforated magnet between the reflector 107 or objective lens 108 and the stage 106 and use the hole in the magnet as the optical path for the laser beam, but the application of a magnetic field to the motor 109 would be the same.

[0026] In this embodiment, as described above, the magnetization process and the local heating process are performed at different timings, making it possible to provide the magnetic field application device 101 for the magnetization process and the heating device 102 for the local heating process as separate devices. Since interference between the laser beam irradiation path 115 and the magnet 104 does not occur in principle, and interference between the magnetic field application device 101 and the heating device 102 is also unlikely to occur, the configurations of the magnetic field application device 101 and the heating device 102 are simplified. Moreover, since the magnetic field application device 101 and the heating device 102 can be placed separately, the influence of the magnetic field from the magnetic field application device 101 on the heating device 102 is less likely to occur.

[0027] Furthermore, in this embodiment, since the ferromagnetic layer 631 is magnetized in the Z direction, it is easy to perform the magnetization process (step S2) and the local heating process (step S3) separately. When a magnetic field in the Z direction is applied to the ferromagnetic layer 631, the ferromagnetic layer 631 is magnetized in the Z direction, and even when the application of the magnetic field is stopped, the state of being magnetized in the Z direction is maintained. This is because the ferromagnetic layer 631 has a large magnetic anisotropy in the film thickness direction (Z direction), and the magnetization in the Z direction is stable and does not fluctuate easily. Therefore, by performing the local heating process in this state, a first magnetized fixed layer 63 that is magnetized in the Z direction can be obtained.

[0028] In contrast, in the case of a ferromagnetic layer magnetized in the in-plane direction (X direction), if the magnetic field is stopped after magnetization in the in-plane direction, the magnetization direction of the ferromagnetic layer tends to vary within the plane. This is because, generally, the in-plane magnetization of an in-plane magnetized film is relatively unstable and prone to fluctuations compared to the magnetization in the film thickness direction of a perpendicular magnetized film magnetized in the film thickness direction. If a local heating process is performed in this state, the state of varying magnetization directions becomes fixed. To avoid this, it is desirable to continue applying a magnetic field to the ferromagnetic layer and perform the local heating process while maintaining the state in which the ferromagnetic layer is magnetized in the X direction. In other words, the method of this embodiment, in which the magnetization process and the local heating process are performed separately, is not very suitable for a magnetic sensor in which the first magnetization fixing layer 63 is magnetized in the in-plane direction, but it can be suitably applied to a magnetic sensor 1 in which the first magnetization fixing layer 63 is magnetized in the film thickness direction.

[0029] (Second embodiment) Figure 4(a) shows a schematic configuration of the magnetic sensor 1 according to the second embodiment. The configuration and effects, which are not described, are the same as those of the first embodiment. The magnetic laminate 6 has a magnetization free layer 61, a non-magnetic layer 62, a first magnetization fixed layer 63, an intermediate layer 64, a second magnetization fixed layer 65, and an antiferromagnetic layer 66. The magnetization free layer 61, the non-magnetic layer 62, the first magnetization fixed layer 63, and the antiferromagnetic layer 66 can be configured in the same way as in the first embodiment. The antiferromagnetic layer 66 provides the same effects as in the first embodiment. These layers are arranged in the -Z direction from the upper electrode layer 5 to the lower electrode layer 7 in the order of magnetization free layer 61, non-magnetic layer 62, first magnetization fixed layer 63, intermediate layer 64, second magnetization fixed layer 65, and antiferromagnetic layer 66, with adjacent layers touching each other. In other words, in this embodiment, the second magnetization-fixed layer 65 is a magnetization-fixed layer in contact with the antiferromagnetic layer 66, and the first magnetization-fixed layer 63 is an intermediate ferromagnetic layer. These layers may be stacked in opposite directions, and specifically, they may be arranged in the order of antiferromagnetic layer 66, second magnetization-fixed layer 65, intermediate layer 64, first magnetization-fixed layer 63, non-magnetic layer 62, and magnetization-free layer 61 in the -Z direction from the upper electrode layer 5 toward the lower electrode layer 7.

[0030] The first magnetization fixed layer 63 is magnetically coupled to the second magnetization fixed layer 65 by a synthetic antiferromagnetic coupling via an intermediate layer 64. The magnetization direction of the first magnetization fixed layer 63 is fixed in the opposite direction to the magnetization direction of the second magnetization fixed layer 65. The first magnetization fixed layer 63 and the second magnetization fixed layer 65 can be formed from multilayer films of Co and Pt, or from materials with high perpendicular magnetic anisotropy such as multilayer films of Co and Pd, or multilayer films of Co and Ni. The intermediate layer 64 is made of a non-magnetic metal such as ruthenium that produces RKKY (Ruderman-Kittel-Kasuya-Yosida) bonds. A multilayer film consisting of a first magnetization fixed layer 63, an intermediate layer 64, and a second magnetization fixed layer 65 is also called a SAF (Synthetic Antiferromagnetic) structure. Because the magnetization directions of the first magnetization fixed layer 63 and the second magnetization fixed layer 65 are oriented in opposite directions, the leakage magnetic field applied from the first magnetization fixed layer 63 to the magnetization free layer 61 can be suppressed. The magnitudes of the magnetic moments of the first magnetization fixed layer 63 and the second magnetization fixed layer 65 can be made to be approximately the same. In Figure 4, the first magnetization fixed layer 63 is magnetized in the -Z direction and the second magnetization fixed layer 65 is magnetized in the +Z direction, but the first magnetization fixed layer 63 may be magnetized in the +Z direction and the second magnetization fixed layer 65 may be magnetized in the -Z direction.

[0031] Figure 4(b) shows a schematic configuration of a modified example of the magnetic sensor 1 of the second embodiment. The magnetization direction of the magnetized free layer 61 may form a vortex shape in a plane perpendicular to the Z direction in a zero magnetic field state. For details, please refer to the description of the first embodiment.

[0032] (Manufacturing method for magnetic sensor 1) The magnetic sensor 1 of this embodiment can be manufactured in the same manner as in the first embodiment. To manufacture the magnetic sensor 1, first, a lower electrode layer 7, a laminated film 601, and an upper electrode layer 5 are sequentially formed on a wafer 8, which is a substrate (step S1). Figure 5 shows the configuration of the laminated film 601 in this embodiment. The laminated film 601 of this embodiment is created by sequentially forming an antiferromagnetic layer 66, a ferromagnetic layer 651, an intermediate layer 64, a ferromagnetic layer 631, a non-magnetic layer 62, and a magnetization-free layer 61 on the lower electrode layer 7 in the +Z direction. Next, a magnetization process (step S2) is performed in the same manner as in the first embodiment. The ferromagnetic layer 651 in contact with the antiferromagnetic layer 66 is magnetized to become a second magnetization-fixed layer 65, and the ferromagnetic layer 631 is magnetized to become a first magnetization-fixed layer 63. Next, a local heating process (step S3) is performed to firmly fix the magnetization direction of the second magnetization-fixed layer 65 in the Z direction. The apparatus used in the magnetization process and the local heating process is the same as in the first embodiment. For details, please refer to the description of the first embodiment.

[0033] In this embodiment, when a magnetic field is applied during the magnetization process (step S2) (for example, in the +Z direction), the ferromagnetic layer 651 and the ferromagnetic layer 631 are magnetized in the same direction (+Z direction). However, when the magnetic field is stopped, the SAF structure causes the magnetization directions of the ferromagnetic layer 651 and the ferromagnetic layer 631 to point in opposite directions. In other words, either the magnetization direction of the ferromagnetic layer 651 or the magnetization direction of the ferromagnetic layer 631 is reversed (the magnetization direction becomes -Z direction). Next, a local heating process (step S3) is performed to fix the magnetization directions of the ferromagnetic layer 651 and the ferromagnetic layer 631. Therefore, either the magnetization direction of the first magnetization-fixing layer 63 or the magnetization direction of the second magnetization-fixing layer 65 will be opposite to the direction in which the magnetic field was applied during magnetization. Functionally, there is no problem regardless of which ferromagnetic layer's magnetization direction is reversed. However, since magnetic sensors 1 are usually manufactured in large quantities on a wafer-by-wafer or lot-by-lot basis, variations in the magnetization direction of the first magnetization fixed layer 63 and the second magnetization fixed layer 65 within the same wafer and lot are undesirable because they result in variations in output within the same wafer and lot.

[0034] When the magnetic field is removed, the direction of magnetization of either the ferromagnetic layer 651 or the ferromagnetic layer 631 reverses depending on the magnetic properties of the ferromagnetic layers 651 and 631. For example, a ferromagnetic layer with a small magnetic moment is more likely to reverse its magnetization direction than a ferromagnetic layer with a large magnetic moment. Therefore, to suppress variations in magnetization direction, it is preferable to create a certain difference in the magnetic moments of the ferromagnetic layers 651 and 631. For example, if the ferromagnetic layers 651 and 631 are formed from the same material, a difference in film thickness or volume can be created. A ferromagnetic layer with a larger film thickness or volume will also have a larger magnetic moment. If the film thickness or volume of the ferromagnetic layers 651 and 631 are similar, materials with different magnetic moments per unit volume can be used. However, if the difference in magnetic moments between the ferromagnetic layers 651 and 631 is too large, the leakage magnetic field from the ferromagnetic layer 631 will have a greater influence on the magnetization-free layer 61. Therefore, when the magnetic moment of the first magnetization fixed layer 63 is M1 and the magnetic moment of the second magnetization fixed layer 65 is M2, it is preferable that |M2-M1| / M1 is 3% or more and 20% or less.

[0035] Furthermore, since ferromagnetic layers with low perpendicular magnetic anisotropy are more prone to magnetization direction reversal than ferromagnetic layers with high perpendicular magnetic anisotropy, it is possible to create a difference in the magnitude of perpendicular magnetic anisotropy between the first magnetization fixed layer 63 and the second magnetization fixed layer 65. For example, when the first magnetization fixed layer 63 and the second magnetization fixed layer 65 are formed as multilayer films (e.g., Co film and Pt film), a difference in the magnitude of perpendicular magnetic anisotropy can be created by varying the film thickness ratio of the films constituting the multilayer film (e.g., Co film and Pt film). This method is preferable for suppressing the influence of leakage magnetic fields because the magnetic moments of the first magnetization fixed layer 63 and the second magnetization fixed layer 65 may be the same.

[0036] (Third embodiment) Figure 6 shows a schematic configuration of the magnetic sensor 1 according to the third embodiment. The magnetic sensor 1 of this embodiment combines the magnetic field detection elements 2 of the first and second embodiments described above as a half-bridge. The magnetic sensor 1 has first and second element units 11 and 12, each containing at least one magnetic field detection element 2. In one embodiment, the first and second element units 11 and 12 each contain an array in which multiple magnetic field detection elements 2 are connected in series. The first element unit 11 and the second element unit 12 form a set 15 connected in series, with one end of the set 15 connected to the power supply VDD and the other end connected to ground (GND). The voltage drop across the first and second element units 11 and 12 is approximately proportional to the electrical resistance of the first and second element units 11 and 12. Therefore, if the electrical resistances of the first and second element units 11 and 12 are R1 and R2, respectively, the midpoint voltage V1 is V1 = R2 / (R1 + R2) × VDD. The magnetic sensor 1 has an output unit 17 located between the first element unit 11 and the second element unit 12, and the output unit 17 outputs a midpoint voltage V1.

[0037] The magnetization direction of the magnetization fixed layer in contact with the antiferromagnetic layer 66 of the first element unit 11 and the magnetization direction of the magnetization fixed layer in contact with the antiferromagnetic layer 66 of the second element unit 12 are opposite to each other. In the first embodiment, the magnetization fixed layer in contact with the antiferromagnetic layer 66 is the first magnetization fixed layer 63, and in the second embodiment, it is the second magnetization fixed layer 65.

[0038] (Manufacturing method for magnetic sensor 1) The magnetic sensor 1 according to the third embodiment is a combination of multiple magnetic field sensing elements 2, and each magnetic field sensing element 2 can be manufactured by the manufacturing method of each embodiment described above. Here, with reference to Figure 7, the magnetization process and local heating process of each element unit 11, 12 will be mainly described. The magnetic field sensing element 2 has the magnetic laminate 6 of the first embodiment, but a magnetic field sensing element 2 equipped with the magnetic laminate 6 of the second embodiment can be manufactured in the same manner. The symbols indicating the +Z direction and -Z direction in Figure 7 indicate the magnetization direction of the ferromagnetic layer 631 or the first magnetization fixing layer 63 in Figure 2.

[0039] First, as shown in Figure 7(a), a first magnetic field H1 in the -Z direction is applied to the first and second element units 11 and 12, and then the application of the first magnetic field H1 is stopped. The ferromagnetic layer 631 of the first element unit 11 is magnetized in the -Z direction and becomes the first magnetization fixed layer 63. At this time, the ferromagnetic layer 631 of the second element unit 12 is also magnetized in the -Z direction. Next, as shown in Figure 7(b), the first element unit 11 is irradiated with laser light and heated to a temperature above the blocking temperature of the antiferromagnetic layer 66 of the first element unit 11, fixing the magnetization direction of the first magnetization fixed layer 63 by exchange coupling with the antiferromagnetic layer 66. Because local heating is performed with laser light, the heating of the second element unit 12 is kept to a sufficiently low level.

[0040] Next, as shown in Figure 7(c), a second magnetic field H2 in the +Z direction is applied to the first and second element units 11 and 12, and then the application of the second magnetic field H2 is stopped. The second magnetic field H2 is in the opposite direction to the first magnetic field H1 (the direction is 180° different), but it is sufficient that it has at least a component in the opposite direction to the first magnetic field H1. The ferromagnetic layer 631 of the second element unit 12 is already magnetized in the -Z direction, but when a magnetic field in the +Z direction is applied, it is magnetized in the +Z direction and becomes the first magnetization fixed layer 63. At this time, the magnetization direction of the first magnetization fixed layer 63 of the first element unit 11 may be reversed temporarily, but when the application of the magnetic field is stopped, the magnetization direction returns to the -Z direction due to exchange coupling with the antiferromagnetic layer 66. Next, as shown in Figure 7(d), the second element unit 12 is irradiated with laser light to heat it to a temperature above the blocking temperature of the antiferromagnetic layer 66 of the second element unit 12, thereby fixing the magnetization direction of the first magnetization fixing layer 63 through exchange coupling with the antiferromagnetic layer 66. The laser light is irradiated at multiple positions, but considering the formation accuracy of the element unit, it is preferable that the spacing between the laser light irradiation positions be about 5 μm or more, preferably about 10 μm or more.

[0041] In this embodiment, the first or second element units 11 and 12 are locally heated using laser annealing. However, the heating method is not limited to laser light, as long as it is possible to locally heat the first or second element unit 11 or the second element unit 12. For example, heating wiring may be provided near the first and second element units 11 and 12, and the heating wiring may be energized to generate heat, thereby selectively heating the first and second element units 11 and 12.

[0042] (Fourth embodiment) Figure 8 shows a schematic configuration of the magnetic sensor 1 according to the fourth embodiment. The magnetic sensor 1 of this embodiment combines the magnetic field detection elements 2 of the first and second embodiments described above as a full bridge. The magnetic sensor 1 has first to fourth element units 11 to 14, each containing at least one magnetic field detection element 2. In one embodiment, the first to fourth element units 11 to 14 each contain an array in which multiple magnetic field detection elements 2 are connected in series. The first element unit 11 and the second element unit 12 form a first set 16A connected in series, and the third element unit 13 and the fourth element unit 14 form a second set 16B connected in series, with one end of the first set 16A and the second set 16B connected to the power supply VDD and the other end connected to ground (GND). The first element unit 11 and the fourth element unit 14 are located on the side of the power supply VDD, and the second element unit 12 and the third element unit 13 are located on the ground side (GND). The magnetic sensor 1 has a differencer 18 that calculates the difference between the output V1 between the first element unit 11 and the second element unit 12 and the output V2 between the third element unit 13 and the fourth element unit 14.

[0043] The magnetization direction of the magnetization fixed layer in contact with the antiferromagnetic layer 66 of the first element unit 11 and the third element unit 13 is the same, while the magnetization direction of the magnetization fixed layer in contact with the antiferromagnetic layer 66 of the second element unit 12 and the fourth element unit 14 is opposite to the magnetization direction of the magnetization fixed layer in contact with the antiferromagnetic layer 66 of the first element unit 11 and the third element unit 13. In the first embodiment, the magnetization fixed layer in contact with the antiferromagnetic layer 66 is the first magnetization fixed layer 63, and in the second embodiment, it is the second magnetization fixed layer 65.

[0044] The voltage drop across each element unit 11-14 is approximately proportional to the electrical resistance of the element units 11-14. Therefore, if the electrical resistances of the first to fourth element units 11-14 are R1-R4 respectively, then the midpoint voltage V1 is V1 = R2 / (R1+R2) × VDD, and the midpoint voltage V2 is V2 = R3 / (R3+R4) × VDD. By calculating the difference V1-V2 between the midpoint voltages V1 and V2 using the differencer 18, twice the sensitivity can be obtained compared to detecting the midpoint voltages V1 and V2 directly. Furthermore, even if the midpoint voltages V1 and V2 are offset, the effect of the offset can be eliminated by detecting the difference.

[0045] (Manufacturing method for magnetic sensor 1) Since the magnetic sensor 1 according to the fourth embodiment is a combination of multiple magnetic field sensing elements 2, each magnetic field sensing element 2 can be manufactured by the manufacturing method of each embodiment described above. Here, referring to Figure 9, the magnetization process and local heating process of each element unit 11 to 14 will be mainly described, but these processes are basically the same as those of the third embodiment. The magnetic field sensing element 2 has the magnetic laminate 6 of the first embodiment, but a magnetic field sensing element 2 equipped with the magnetic laminate 6 of the second embodiment can be manufactured in the same manner. The symbols indicating the +Z direction and -Z direction in Figure 9 indicate the magnetization direction of the ferromagnetic layer 631 or the first magnetization fixing layer 63 in Figure 2.

[0046] First, as shown in Figure 9(a), a first magnetic field H1 in the -Z direction is applied to the first to fourth element units 11 to 14, and then the application of the first magnetic field H1 is stopped. The ferromagnetic layers 631 of the first and third element units 11 and 13 are magnetized and become the first magnetization fixed layer 63. Next, as shown in Figure 9(b), laser light is irradiated onto the first and third element units 11 and 13, heating them to a temperature above the blocking temperature of the antiferromagnetic layers 66 of the first and third element units 11 and 13, and fixing the magnetization direction of the first magnetization fixed layer 63 by exchange coupling with the antiferromagnetic layer 66. Next, as shown in Figure 9(c), a second magnetic field H2 in the +Z direction is applied to the first to fourth element units 11 to 14, and then the application of the second magnetic field H2 is stopped. The ferromagnetic layers 631 of the second and fourth element units 12 and 14 are magnetized in the +Z direction to form the first magnetization-fixing layer 63. Next, as shown in Figure 9(d), the second and fourth element units 12 and 14 are irradiated with laser light to heat them to a temperature above the blocking temperature of the antiferromagnetic layers 66 of the second and fourth element units 12 and 14, thereby fixing the magnetization direction of the first magnetization-fixing layer 63 through exchange coupling with the antiferromagnetic layers 66. In this embodiment as well, it is preferable that the distance between the laser light irradiation positions be about 5 μm or more, preferably about 10 μm or more.

[0047] (Examples) Samples were prepared by laminating an antiferromagnetic layer and a ferromagnetic layer, and their magnetization curves were determined. In the example, a magnetic field perpendicular to the film surface of the ferromagnetic layer was applied to the prepared sample, and the sample was heated after the magnetic field was removed. In Comparative Example 2, the sample was heated while a magnetic field perpendicular to the film surface of the ferromagnetic layer was applied to the prepared sample. The example corresponds to the first to fourth embodiments, and Comparative Example 2 corresponds to Comparative Example 1. Figure 10(a) shows the magnetization curve of the example, and Figure 10(b) shows the magnetization curve of Comparative Example 2. The horizontal axis of the magnetization curve represents the external magnetic field strength, and the vertical axis represents the magnetic moment. The ranges of the horizontal and vertical axes are the same in Figures 10(a) and 10(b). The magnetization curves of the example and Comparative Example 2 are almost the same shape, and the center of the magnetization curve is at almost the same position on the horizontal axis. From this, it was found that there is almost no difference in exchange coupling strength between annealing while applying a magnetic field, as in the conventional technique, and annealing after applying a magnetic field, as in the example. In other words, even in the example, an exchange coupling strength sufficient to fix the magnetization direction of the magnetization-fixing layer in contact with the antiferromagnetic layer can be obtained.

[0048] (Note) This specification includes the following disclosures. [Manufacturing method 1] A laminated film is formed having a ferromagnetic layer and an antiferromagnetic layer, wherein the ferromagnetic layer and the antiferromagnetic layer are in contact with each other in a first direction, Applying a magnetic field in the first direction to the laminated film, a magnetization-fixed layer is created from the ferromagnetic layer in which the magnetization direction is fixed with respect to the external magnetic field. After stopping the application of the magnetic field, the laminated film is heated to a temperature above the blocking temperature of the antiferromagnetic layer to create a magnetic laminate. A method for manufacturing a magnetic laminate having the following characteristics. [Manufacturing method 2] The manufacturing method according to claim 1, wherein the laminated film is heated by laser light. [Manufacturing method 3] The manufacturing method according to manufacturing method 1 or 2, wherein after stopping the application of the magnetic field, the laminated film is transferred for heating of the laminated film. [Manufacturing method 4] The manufacturing method according to any one of the manufacturing methods 1 to 3, wherein the laminated film has a magnetization-free layer whose magnetization direction changes with respect to an external magnetic field, and a non-magnetic layer, and the ferromagnetic layer, the antiferromagnetic layer, the magnetization-free layer, and the non-magnetic layer are arranged in the order of the magnetization-free layer, the non-magnetic layer, the ferromagnetic layer, and the antiferromagnetic layer in the first direction. [Manufacturing method 5] The manufacturing method according to any one of the manufacturing methods 1 to 3, wherein the laminated film comprises a magnetization-free layer whose magnetization direction changes with respect to an external magnetic field, a non-magnetic layer, an intermediate ferromagnetic layer, and an intermediate layer made of a non-magnetic metal, and the ferromagnetic layer, the antiferromagnetic layer, the magnetization-free layer, the non-magnetic layer, the intermediate ferromagnetic layer, and the intermediate layer are arranged in the order of the magnetization-free layer, the non-magnetic layer, the intermediate ferromagnetic layer, the intermediate layer, the ferromagnetic layer, and the antiferromagnetic layer in the first direction. [Manufacturing method 6] The manufacturing method according to manufacturing method 5, wherein when the magnetic moment of the intermediate ferromagnetic layer is M1 and the magnetic moment of the ferromagnetic layer is M2, |M2-M1| / M1 is 3% or more and 20% or less. [Manufacturing method 7] The manufacturing method according to manufacturing method 5, wherein the magnitude of perpendicular magnetic anisotropy of the intermediate ferromagnetic layer and the ferromagnetic layer are different from each other. [Manufacturing method 8] The manufacturing method according to any one of the manufacturing methods 4 to 7, wherein the magnetization direction of the magnetized free layer forms a vortex shape in a plane perpendicular to the first direction in the absence of the external magnetic field. [Manufacturing method 9] The manufacturing method according to any one of the manufacturing methods 4 to 8, wherein the non-magnetic layer consists of an insulating layer. [Manufacturing method 10] A ferromagnetic layer, a magnetization-free layer whose magnetization direction changes with respect to an external magnetic field, a non-magnetic layer, and an antiferromagnetic layer are arranged in a first direction in the order of the magnetization-free layer, the non-magnetic layer, the ferromagnetic layer, and the antiferromagnetic layer, and each of the first and second element units each includes a laminated film in which the ferromagnetic layer and the antiferromagnetic layer are in contact with each other. The first and second element units are connected in series to form a set, with one end of the set connected to a power source and the other end grounded. Applying a first magnetic field in the first direction to the first element unit, and creating a magnetization-fixed layer from the ferromagnetic layer of the first element unit in which the magnetization direction is fixed with respect to the external magnetic field, After stopping the application of the first magnetic field, the first element unit is heated to a temperature above the blocking temperature of the antiferromagnetic layer of the first element unit, A second magnetic field having a component opposite to the first direction is applied to the second element unit, and a magnetization-fixed layer is created from the ferromagnetic layer of the second element unit, in which the magnetization direction is fixed with respect to the external magnetic field. After stopping the application of the second magnetic field, the second element unit is heated to a temperature above the blocking temperature of the antiferromagnetic layer of the second element unit, A method for manufacturing a magnetic sensor having [Manufacturing method 11] The first to fourth element units each include a laminated film in which a ferromagnetic layer, a magnetization-free layer whose magnetization direction changes with respect to an external magnetic field, a non-magnetic layer, and an antiferromagnetic layer are arranged in a first direction in the order of the magnetization-free layer, the non-magnetic layer, the ferromagnetic layer, and the antiferromagnetic layer, and the ferromagnetic layer and the antiferromagnetic layer are in contact with each other. The first and second element units are connected in series to form a first set, and the third and fourth element units are connected in series to form a second set. One end of the first and second sets is connected to a power supply and the other end is grounded. The first and fourth element units are positioned on the side of the power supply, and the second and third element units are positioned on the grounded side. To create a differencer that calculates the difference between the output between the first element unit and the second element unit and the output between the third element unit and the fourth element unit, Applying a first magnetic field in the first direction to the first and third element units, and creating a magnetization-fixed layer from the ferromagnetic layer of the first and third element units, in which the magnetization direction is fixed with respect to the external magnetic field, After stopping the application of the first magnetic field, the first and third element units are heated to a temperature above the blocking temperature of the antiferromagnetic layer of the first and third element units, A second magnetic field having a component opposite to the first direction is applied to the second and fourth element units, and a magnetization-fixed layer is created from the ferromagnetic layer of the second and fourth element units, in which the magnetization direction is fixed with respect to the external magnetic field. After stopping the application of the second magnetic field, the second and fourth element units are heated to a temperature above the blocking temperature of the antiferromagnetic layer of the second and fourth element units, A method for manufacturing a magnetic sensor having [Manufacturing method 12] The manufacturing method according to manufacturing method 10 or 11, wherein the second magnetic field is in the opposite direction to the first magnetic field. [Configuration 1] A magnetic field application device that applies a magnetic field in the first direction to a laminated film of a wafer containing a ferromagnetic layer and an antiferromagnetic layer in contact with each other in a first direction, and creates a magnetization-fixed layer from the ferromagnetic layer in which the magnetization direction is fixed with respect to an external magnetic field, A heating device for heating the laminated film to a temperature above the blocking temperature of the antiferromagnetic layer, A transfer device for transferring the wafer between the magnetic field application device and the heating device, A manufacturing apparatus for magnetic laminates having the following features. [Configuration 2] The manufacturing apparatus according to configuration 1, wherein the heating device has a laser light irradiation device for heating the laminated film with laser light. [Explanation of Symbols]

[0049] 1. Magnetic sensor 2 Magnetic field detection element 6 Magnetic Laminate 7 Lower electrode layer 11-14 Element Units 1-4 61 Magnetization free layer 62 First non-magnetic layer 63 First magnetization fixed layer 64 Middle Class 65 Second magnetization fixed layer 66 Antiferromagnetic layer 100 Magnetization heating device 101 Magnetic field application device 102 Heating device 103 Transfer device

Claims

1. A laminated film is formed having a ferromagnetic layer and an antiferromagnetic layer, wherein the ferromagnetic layer and the antiferromagnetic layer are in contact with each other in a first direction, Applying a magnetic field in the first direction to the laminated film, a magnetization-fixed layer is created from the ferromagnetic layer in which the magnetization direction is fixed with respect to the external magnetic field. After stopping the application of the magnetic field, the laminated film is heated to a temperature above the blocking temperature of the antiferromagnetic layer to create a magnetic laminate. A method for manufacturing a magnetic laminate having the following characteristics.

2. The manufacturing method according to claim 1, wherein the laminated film is heated by laser light.

3. The manufacturing method according to claim 1, wherein after stopping the application of the magnetic field, the laminated film is transferred for heating of the laminated film.

4. The manufacturing method according to any one of claims 1 to 3, wherein the laminated film has a magnetization-free layer whose magnetization direction changes with respect to an external magnetic field, and a non-magnetic layer, and the ferromagnetic layer, the antiferromagnetic layer, the magnetization-free layer, and the non-magnetic layer are arranged in the first direction in the order of the magnetization-free layer, the non-magnetic layer, the ferromagnetic layer, and the antiferromagnetic layer.

5. The manufacturing method according to any one of claims 1 to 3, wherein the laminated film comprises a magnetization-free layer whose magnetization direction changes with respect to an external magnetic field, a non-magnetic layer, an intermediate ferromagnetic layer, and an intermediate layer made of a non-magnetic metal, and the ferromagnetic layer, the antiferromagnetic layer, the magnetization-free layer, the non-magnetic layer, the intermediate ferromagnetic layer, and the intermediate layer are arranged in the order of the magnetization-free layer, the non-magnetic layer, the intermediate ferromagnetic layer, the intermediate layer, the ferromagnetic layer, and the antiferromagnetic layer in the first direction.

6. The manufacturing method according to claim 5, wherein when the magnetic moment of the intermediate ferromagnetic layer is M1 and the magnetic moment of the ferromagnetic layer is M2, |M2 - M1| / M1 is 3% or more and 20% or less.

7. The manufacturing method according to claim 5, wherein the magnitude of perpendicular magnetic anisotropy of the intermediate ferromagnetic layer and the ferromagnetic layer are different from each other.

8. The manufacturing method according to claim 5, wherein the magnetization direction of the magnetized free layer forms a vortex shape in a plane perpendicular to the first direction in the absence of the external magnetic field.

9. The manufacturing method according to claim 5, wherein the non-magnetic layer is an insulating layer.

10. A ferromagnetic layer, a magnetization-free layer whose magnetization direction changes with respect to an external magnetic field, a non-magnetic layer, and an antiferromagnetic layer are arranged in a first direction in the order of the magnetization-free layer, the non-magnetic layer, the ferromagnetic layer, and the antiferromagnetic layer, and each of the first and second element units each includes a laminated film in which the ferromagnetic layer and the antiferromagnetic layer are in contact with each other. The first and second element units are connected in series to form a set, with one end of the set connected to a power source and the other end grounded. An output unit is provided between the first element unit and the second element unit, Applying a first magnetic field in the first direction to the first element unit, and creating a magnetization-fixed layer from the ferromagnetic layer of the first element unit in which the magnetization direction is fixed with respect to the external magnetic field, After stopping the application of the first magnetic field, the first element unit is heated to a temperature above the blocking temperature of the antiferromagnetic layer of the first element unit, A second magnetic field having a component opposite to the first direction is applied to the second element unit, and a magnetization-fixed layer is created from the ferromagnetic layer of the second element unit, in which the magnetization direction is fixed with respect to the external magnetic field. After stopping the application of the second magnetic field, the second element unit is heated to a temperature above the blocking temperature of the antiferromagnetic layer of the second element unit, A method for manufacturing a magnetic sensor having

11. The first to fourth element units each include a laminated film in which a ferromagnetic layer, a magnetization-free layer whose magnetization direction changes with respect to an external magnetic field, a non-magnetic layer, and an antiferromagnetic layer are arranged in a first direction in the order of the magnetization-free layer, the non-magnetic layer, the ferromagnetic layer, and the antiferromagnetic layer, and the ferromagnetic layer and the antiferromagnetic layer are in contact with each other. The first and second element units are connected in series to form a first set, and the third and fourth element units are connected in series to form a second set. One end of the first and second sets is connected to a power source and the other end is grounded. The first and fourth element units are positioned on the side of the power source, and the second and third element units are positioned on the grounded side. To create a differencer that calculates the difference between the output between the first element unit and the second element unit and the output between the third element unit and the fourth element unit, Applying a first magnetic field in the first direction to the first and third element units, and creating a magnetization-fixed layer from the ferromagnetic layer of the first and third element units, in which the magnetization direction is fixed with respect to the external magnetic field, After stopping the application of the first magnetic field, the first and third element units are heated to a temperature above the blocking temperature of the antiferromagnetic layer of the first and third element units, A second magnetic field having a component opposite to the first direction is applied to the second and fourth element units, and a magnetization-fixed layer is created from the ferromagnetic layer of the second and fourth element units, in which the magnetization direction is fixed with respect to the external magnetic field. After stopping the application of the second magnetic field, the second and fourth element units are heated to a temperature above the blocking temperature of the antiferromagnetic layer of the second and fourth element units, A method for manufacturing a magnetic sensor having

12. The manufacturing method according to claim 10 or 11, wherein the second magnetic field is in the opposite direction to the first direction.

13. A magnetic field application device that applies a magnetic field in the first direction to a laminated film of a wafer containing a ferromagnetic layer and an antiferromagnetic layer in contact with each other in a first direction, and creates a magnetization-fixed layer from the ferromagnetic layer in which the magnetization direction is fixed with respect to an external magnetic field, A heating device for heating the laminated film to a temperature above the blocking temperature of the antiferromagnetic layer, A transfer device for transferring the wafer between the magnetic field application device and the heating device, A manufacturing apparatus for magnetic laminates having the following features.

14. The manufacturing apparatus according to claim 13, wherein the heating device has a laser light irradiation device for heating the laminated film with laser light.

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