JP2018194534A - Magnetic sensor - Google Patents

Abstract

To provide a magnetic sensor that can increase the detection accuracy.SOLUTION: A magnetic sensor 1 according to an embodiment of the present invention includes: an element part 20 including a magnetization free layer 21, an insulating non-magnetic layer 22 formed on the magnetization free layer 21, and a magnetization fixing layer 23 on the non-magnetic layer 22; and a magnetism collecting part 30 electrically insulated from the element part 20. When the direction of the magnetism sensing shaft of the element part 20 is denoted by a first direction, the length LFC of the magnetism collecting part 30 in the first direction is 5 mm or larger, the thickness tFC of the magnetism collecting part 30 is 5 μm, and the relation of LFC>tFC is satisfied.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a magnetic sensor.

As a magnetic sensor for detecting a magnetic field, there is a spin valve MR magnetic sensor using a GMR (giant magnetoresistance) effect or a TMR (tunnel magnetoresistance) effect.
A spin valve MR magnetic sensor has a structure in which a nonmagnetic material is sandwiched between ferromagnetic materials (ferromagnetic material / nonmagnetic material / ferromagnetic material), and the magnetization of one magnetic material is fixed by an antiferromagnetic material (magnetization). In general, the magnetization of the other ferromagnetic material (magnetization free layer) can rotate freely with respect to an external magnetic field (spin valve structure). In the spin valve MR magnetic sensor, when the external magnetic field H is applied and the relative angle between the magnetization of the magnetization fixed layer and the magnetization of the magnetization free layer changes, the current flowing through the non-magnetic intermediate layer changes. It can be detected (see, for example, Patent Document 1).

  A spin-valve MR magnetic sensor is known to exhibit a large magnetoresistance (MR) change with a small magnetic field, and is mainly used for a magnetic head of a hard disk. In addition, it is known that a spin valve MR magnetic sensor is more sensitive than a magnetic sensor (Hall element) using the Hall effect, that is, can detect a minute magnetic field (for example, patents). Reference 2).

  There are other types of MR sensor, for example, an AMR magnetic sensor using the AMR (anisotropic magnetoresistance) effect. AMR magnetic sensors (AMR elements) are less sensitive than GMR magnetic sensors and TMR magnetic sensors, but have excellent noise characteristics, and the magnetic detection performance is comparable to GMR magnetic sensors and TMR magnetic sensors. Yes (see, for example, Patent Document 3).

JP 9-199769 A Japanese Patent Laid-Open No. 2005-221383 Japanese Patent No. 5044070

The spin valve MR magnetic sensor using the GMR effect or the TMR effect as described above has a feature that the magnetic sensitivity is higher than that of the Hall element or the AMR element. However, the sensitivity is insufficient to obtain a very small magnetic field such as a magnetic field generated from a living body.
Therefore, the present invention has been made in view of such circumstances, and an object thereof is to provide a magnetic sensor capable of improving detection accuracy.

  In order to solve the above problems, a magnetic sensor of one embodiment of the present invention includes a magnetization free layer, an insulating nonmagnetic layer formed on the magnetization free layer, and a magnetization fixed formed on the nonmagnetic layer. An element portion having a layer; and a magnetic concentrating portion electrically insulated from the element portion, and the first direction of the magnetic converging portion is defined as a first direction of a magnetosensitive axis direction of the element portion. The length LFC in the direction is 5 mm or more, the thickness tFC of the magnetic converging portion is 5 μm or more, and LFC> tFC is satisfied.

  ADVANTAGE OF THE INVENTION According to this invention, the magnetic sensor which can implement | achieve the more excellent sensitivity characteristic can be provided.

It is the top view (a) which shows the magnetic sensor which concerns on 1st embodiment of this invention, and its A-A 'sectional drawing (b). It is the top view (a) which shows the modification of the magnetic sensor which concerns on 1st embodiment of this invention, and its A-A 'sectional drawing (b). It is the top view (a) which shows the magnetic sensor which concerns on 2nd embodiment of this invention, and its A-A 'sectional drawing (b). It is the top view (a) which shows the magnetic sensor which concerns on 3rd embodiment of this invention, and its A-A 'sectional drawing (b). It is a figure explaining the magnetic sensor which has a hard bias part, (a) shows arrangement | positioning of the hard bias part which the magnetic sensor of 4th embodiment has. 3 is a plan view showing a magnetic converging part and an element part of the magnetic sensor of Example 1. FIG. It is a top view which shows the magnetic convergence part and element part of the magnetic sensor of Example 2. FIG. It is a top view which shows the magnetic convergence part and element part of the magnetic sensor of the comparative examples 1 and 2. 3 is a graph showing a magnetization curve obtained using the magnetic sensor of Example 1. It is the plane (a) which shows arrangement | positioning of the magnetic body group used in Examples 11-89 and Comparative Examples 11-77, and its A-A 'sectional drawing (b). It is a graph which shows the result obtained in Examples 11-55 and Comparative Examples 11-77. It is a graph which shows the result obtained in Example 11 and Examples 61-64. It is a graph which shows the result obtained in Examples 81-89 and Comparative Examples 81-82.

[Detailed Description of One Embodiment of the Present Invention]
<Magnetic sensor>
A magnetic sensor according to one embodiment of the present invention includes an element portion including a magnetization free layer, an insulating nonmagnetic layer formed on the magnetization free layer, and a magnetization fixed layer formed on the nonmagnetic layer, and an element portion And a magnetic convergence part electrically insulated. When the direction of the magnetosensitive axis of the element portion is the first direction, the length LFC in the first direction of the magnetic converging portion is 5 mm or more, the thickness tFC of the magnetic converging portion is 5 μm or more, and LFC> tFC Meet.

According to the magnetic sensor of one embodiment of the present invention, as shown in Examples, Comparative Examples, Table 1 and FIG. 11 described later, LFC is 5 mm or more, tFC is 5 μm or more, and LFC> tFC. As a result, the magnetization of the magnetization free layer of the element portion can be greatly amplified, and a magnetic sensor having excellent sensitivity characteristics can be realized.
Inside the magnetic material, a magnetic field opposite to the direction of magnetization is generated, which is called a demagnetizing field. When a magnetic field is applied to the magnetic material from the outside, the demagnetizing field is present, so that the effective magnetism inside the magnetic material is reduced by the amount of the demagnetizing field, and the magnetization is reduced accordingly. For example, with regard to the magnetic converging unit, the magnetic permeability directly connected to the magnetic amplification factor described later is determined by the ratio of magnetization with respect to the external magnetic field. Therefore, a small demagnetizing field is an important factor for realizing excellent sensitivity characteristics. Here, by setting LFC> tFC, it is possible to reduce the demagnetizing field in the direction of the magnetosensitive axis of the magnetic converging unit, and it is possible to improve the sensitivity characteristics of the magnetic sensor.

  The magnetic sensor of one embodiment of the present invention preferably includes a plurality of magnetic converging units, and the element unit is present between the plurality of magnetic converging units. Here, “between magnetic converging portions” means a gap formed between two magnetic converging portions in a top view (plan view). This gap may be filled with other members as long as it is made of a material other than the magnetic converging part. For example, even if a protective layer described later or a magnetization free layer is present in this gap Good. In FIG. 1 described later, the interval between the right end of the magnetic converging unit 30L and the left end of the magnetic converging unit 30R is “between magnetic converging units”.

A magnetic amplification effect can be obtained by bringing the element part closer to the magnetic converging part. However, by disposing the magnetic converging part on both sides of the element part, a magnetic sensor having better sensitivity characteristics can be realized.
Further, the interval DFC between the plurality of magnetic converging portions, the length LFMR in the first direction of the magnetization free layer, and the length LPMR in the first direction of the magnetization fixed layer satisfy LPMR / 4 ≦ DFC ≦ LFMR + 5 × tFC. It is preferable to satisfy. As shown in FIG. 12 and the like, by satisfying LPMR / 4 ≦ DFC ≦ LFMR + 5 × tFC, it becomes possible to amplify the magnetization of the magnetization free layer of the element part more greatly, and a magnetic sensor having excellent sensitivity characteristics is realized. it can.

  In addition, the magnetic sensor of one embodiment of the present invention preferably includes a plurality of element portions each including a plurality of magnetization fixed layers, and includes a wiring portion that electrically connects the plurality of element portions. When a plurality of magnetization fixed layers are electrically connected using this wiring portion, the voltage applied to one junction when driving the sensor can be reduced, so that voltage noise is reduced and better noise characteristics are obtained. Can do. In particular, when connected in series, an improvement in breakdown voltage can be expected. Therefore, a magnetic sensor having better characteristics can be realized.

In this case, the interval between the element portions is preferably set to 100 μm or less from the viewpoint of area efficiency of element fabrication. Further, the interval between the element portions is more preferably 50 μm or less, further preferably 10 μm or less, and further preferably 5 μm or less.
In this case, it is preferable that the plurality of element portions be arranged along a side that is substantially orthogonal to the magnetosensitive axis among the sides that define the magnetic converging unit. By arrange | positioning in this way, the space | interval between magnetic converging parts can be made small. When the interval between the magnetic converging portions is small, magnetic amplification can be performed more efficiently.

  Moreover, it is preferable that the center of the magnetic converging part in the thickness direction is shifted from the center of the element part in the thickness direction. The reason is as follows. In the magnetic sensor of one embodiment of the present invention, the thickness of the magnetic converging portion is 5 mm or more, and the thickness of the element portion is, for example, about 70 nm. In order to match, it is necessary to etch the substrate deeply (2.5 mm or more) by ion milling or the like, which takes time. On the other hand, if the center in the thickness direction of the magnetic converging portion is shifted from the center in the thickness direction of the element portion, it is not necessary to perform deep etching. Therefore, the magnetic sensor of one embodiment of the present invention can be more easily manufactured. It becomes possible.

The element portion has a magnetosensitive axis, and the length in the direction perpendicular to the first direction of the element portion is shorter than the length in the direction perpendicular to the first direction of the magnetic converging portion in a top view. Is preferred. With this configuration, the magnetically amplified magnetic field can be caused to flow into the entire element portion, so that magnetic amplification can be performed more efficiently.
Hereinafter, each component of the magnetic sensor according to one embodiment of the present invention will be described with examples.

(A) Element Unit The element unit includes a magnetization free layer, a nonmagnetic layer, and a magnetization fixed layer formed on the nonmagnetic layer, and has a magnetosensitive axis extending in the first direction.
As for the stacking order of the element portions, it is desirable that the magnetization free layer, the nonmagnetic layer, and the magnetization fixed layer are formed in this order, but the order is not limited. Further, from the viewpoint of improving sensitivity, the nonmagnetic layer is preferably formed of an insulating material.

The magnetosensitive axis of the element portion means a direction in which the sensitivity to an external magnetic field is maximized.
For example, when the application direction of the external magnetic field B and the magnetosensitive axis are inclined by an angle θ, the effective magnetic field Beff felt by the magnetic sensor is expressed by Beff = Bcos θ. When θ = 0, that is, when the application direction of the external magnetic field coincides with the direction of the magnetosensitive axis, the effective magnetic field is maximized, so that the external magnetic field can be detected with the highest sensitivity.

In a predetermined direction in the same plane as the magnetization free layer, an external magnetic field is applied to the magnetic sensor while increasing or decreasing it. The slope of the change in resistance value with respect to the external magnetic field at this time is defined as sensitivity in a predetermined direction.
The slope of the resistance value change is calculated with at least three points between the maximum resistance value and the minimum resistance value, and the direction in which the slope of the resistance value change (that is, sensitivity) becomes maximum is determined by the element portion of the magnetic sensor. It is regarded as the magnetosensitive axis.

Another layer may be inserted above or below the three layers (magnetization free layer, nonmagnetic layer, and magnetization pinned layer), or between the three layers.
It is preferable that a nonmagnetic cap layer is provided at the top of the element portion from the viewpoint of preventing oxidation. The nonmagnetic cap layer is preferably a conductive material such as Au or Ru from the viewpoint of connection with the wiring portion.

  From the viewpoint of adhesion, it is desirable to provide a metal layer such as Ti or Ta between the cap layer and the magnetization free layer or the magnetization fixed layer. The element portion can be formed by a known method. For example, the element portion can be formed by a sputtering method. In the case of forming a plurality of element portions, the stacked film formed on the substrate can be formed by dry etching or wet etching using a mask member formed by a photolithography method.

At this time, the shape of the element portion may be controlled by stopping the etching in the middle of the element portion. In this case, the layer above the etching stop point may be formed in a plurality of portions on the layer below the etching stop point.
Further, the etching stop point can be set arbitrarily. For example, the upper layer may include a magnetization free layer and a part of a nonmagnetic layer, and the lower layer may include a part of a nonmagnetic layer and a magnetization fixed layer.

The upper layer may include a magnetization free layer, a nonmagnetic layer, and a magnetization fixed layer, and the lower layer may be composed of other layers (for example, Ta, Ru, etc.).
Further, the position of the magnetization fixed layer is not limited. The magnetization distribution in the magnetization free layer changes depending on the shape of the magnetic converging portion, the shape of the magnetization free layer, and the positional relationship thereof. For example, as shown in FIGS. 1 and 4, a magnetization fixed layer can be disposed. In particular, when the magnetization free layer and the magnetic converging portion are very close and the area of the magnetization free layer is large, higher sensitivity can be obtained by arranging the magnetization fixed layer closer to the magnetic converging portion as shown in FIG. . On the other hand, when the distance between the magnetization free layer and the magnetic converging portion is long, or when the area of the magnetization free layer is small, as shown in FIG. 1, near the center of the magnetization free layer when the magnetization fixed layer is viewed in the direction of the magnetosensitive axis. Higher sensitivity can be obtained.

In order to determine the easy axis of magnetization of the laminated film, a magnetic field may be applied during film formation parallel to the direction desired to be the easy axis of magnetization.
Here, the easy magnetization axis means a direction that is easily magnetized due to the magnetic anisotropy characteristic of the magnetic material. Magnetic anisotropy is determined by shape magnetism determined by the shape of the magnetic material, shape magnetic anisotropy determined by crystal orientation, induced magnetic anisotropy caused by the arrangement of magnetic atoms, and the like.
Alternatively, the easy axis of magnetization may be determined by performing heat treatment in a magnetic field after forming the laminated film.

(A-2) Nonmagnetic layer The nonmagnetic layer is made of an insulating nonmagnetic material. In general, in the case of a TMR element, an insulating material such as Al ₂ O ₃ or MgO is used, but this is not restrictive. In order to increase the magnetic sensitivity, it is preferable to use MgO for the nonmagnetic layer. Note that the finely processed shape of the nonmagnetic layer does not matter.

(A-3) Magnetization fixed layer The magnetization fixed layer is mainly composed of a ferromagnetic material so that the magnetization direction is not easily changed by an external magnetic field. The magnetization fixed layer does not need to be composed of one material, and may be a multilayer film. As an example, the fixed magnetization layer has a structure in which a ferromagnetic material is pinned with an antiferromagnetic material. As the soft magnetic material, NiFe, CoFeB, CoFeSiB, CoFe and the like are used, but not limited thereto. In order to improve magnetic sensitivity, a multilayer film in which a nonmagnetic layer such as Ru or Ta is inserted in the magnetization fixed layer is preferable. In addition, IrMn, PtMn, or the like is used as an antiferromagnetic material, but is not limited to this configuration. The finely processed shape of the magnetization fixed layer is not limited.

(B) Magnetic focusing portion In the magnetic sensor of one aspect of the present invention, the magnetic focusing portion has a length LFC in the first direction of 5 mm or more, a thickness tFC of 5 μm or more, and satisfies LFC> tFC. is there. The magnetic converging part is made of a soft magnetic material whose film thickness direction is the hard axis direction. Examples of the soft magnetic material include NiFe, CoFeSiB, NiFeCuMo, and CoZrNb, but are not limited thereto.

  The magnetic converging portion can be created by sputtering or plating. The magnetic converging portion can be formed by a known method. For example, a mask member formed by a photolithography method and a seed described later using a material such as Cu or NiFe on the entire surface of the laminated portion. It is possible to form a layer by forming a magnetic converging part by plating or forming a magnetic converging part by vapor deposition or sputtering, and further removing a mask member or an extra seed layer.

  In order to obtain higher sensitivity, it is desirable that the demagnetizing field in the direction of the magnetosensitive axis of the magnetic converging portion is small. Therefore, in a form in which the magnetic sensor includes a plurality of magnetic converging portions, when the direction perpendicular to the first direction and the second direction is the third direction, at least two of the plurality of magnetic converging portions are The length LFC in the first direction is preferably longer than the length WFC in the third direction. With this configuration, a magnetic sensor can be manufactured with a smaller area. Further, since the demagnetizing field is reduced, a higher magnetic amplification effect can be obtained.

Further, the value Hs of the external magnetic field when the magnetization of the magnetic converging portion is saturated preferably satisfies 0 <Hs ≦ 10 [Oe]. From the viewpoint of convenience during use, it is preferable not to be saturated by an environmental magnetic field. Therefore, 0.1 [Oe] ≦ Hs ≦ 10 [Oe] is more preferable, 0.5 [Oe] ≦ Hs ≦ 10 [Oe] is more preferable, and 1 [Oe] ≦ Hs ≦ 10 [Oe] is further preferable. .
In order to completely saturate the magnetization, a strong external magnetic field is actually required. In this specification, the value Hs of the external magnetic field when the magnetization is saturated is an extrapolation line in which the external magnetic field changes in a substantially linear manner with respect to the external magnetic field and the inclination of the saturation magnetization is near zero. The intersection with the value is defined as Hs.

  Here, when the magnetic converging part has a long shape in the direction (first direction) parallel to the magnetosensitive axis of the element part, this direction (first direction) tends to be the easy magnetization axis. The easy magnetization axis is an axial direction in which a magnetic material is easily magnetized, and changes depending on the shape, crystal orientation, and the direction of magnetic field application during film formation and heat treatment. Among these, the effect of the shape of the magnetic material is great, and the magnetic material has a feature (shape anisotropy) that the longitudinal direction of the magnetic material tends to be the easy axis of magnetization. When the direction (first direction) parallel to the magnetosensitive axis of the element portion becomes the easy magnetization axis, there is no value between the positively magnetized state and the negatively magnetized state, and the magnetic converging unit Magnetic convergence is not possible.

  That is, in the magnetic sensor of one embodiment of the present invention, when the dimensional relationship of the magnetic converging portion is LFC> WFC, the first direction is likely to be an easy magnetization axis due to the shape anisotropy described above. However, by forming the magnetic converging portion while applying a magnetic field in the short direction of the magnetic material, the value Hs of the external magnetic field when the magnetization of the magnetic converging portion is saturated because the first direction does not become the easy axis of magnetization. May satisfy 0 <Hs ≦ 10 [Oe]. That is, sufficient magnetic convergence can be realized.

  When the magnetic converging portion is formed by sputtering or the like, for example, after performing the first heat treatment while applying a magnetic field in the short direction, the temperature is lower than the first heat treatment temperature while applying the magnetic field in the longitudinal direction. Second heat treatment is performed. Specifically, the first heat treatment temperature can be about 350 ° C., the second heat treatment temperature can be about 300 ° C., etc., but the optimum temperature varies depending on the crystal state and material. For the heat treatment in a magnetic field, it is possible to employ a method of maintaining the above heat treatment temperature for about 1 hour, followed by gradual cooling and continuing to apply the magnetic field until the temperature is about 100 ° C. or lower.

(B-2) Seed layer The seed layer is necessary as a base for producing the magnetic converging portion by plating. When forming a film on a thermal oxide film, it is preferable to form Cu, NiFe, etc. after forming Ta, Ti, etc. from a viewpoint of adhesiveness. When the seed layer is a nonmagnetic material such as Cu, it does not react to an external magnetic field, but when the seed layer is a magnetic material such as NiFe, the seed layer also has a magnetic convergence effect. In this case, the seed layer and the magnetic converging portion are considered.

(C) Protective layer A protective layer is used in order to maintain insulation of an element part, a wiring part, a magnetic convergence part, etc. The material of the protective layer is not particularly limited as long as it can insulate the element portion, the wiring portion, and the magnetic converging portion, and examples thereof include silicon oxide, silicon nitride, and aluminum oxide. The protective layer is formed so as to cover the entire surface of the element portion, and there is an energization window (that is, an opening) on the junction between the element portion and the wiring portion and on the electrode. In the present invention, the position and shape of the energization window are not limited.

(D) Wiring part A wiring part connects an electrode and an element part through the electricity supply window formed on the insulating layer. Further, when a plurality of magnetic sensors are connected in series or in parallel, they are also used to electrically connect the element portions. From the viewpoint of adhesion, it is desirable to provide a layer such as Ti or Ta between the cap layer and the wiring portion.

The material of the wiring part is not particularly limited as long as it is a conductive material (for example, Au, Cu, Cr, Ni, Al, Ta, Ru, etc.) that can electrically connect the element parts to each other. . Further, the wiring portion may be made of a single material, or may be a mixture or a laminate of a plurality of materials. The wiring part can be formed by a known method, and as an example, a mask member formed by a photolithography method, and a conductive material is formed on the entire surface of the element part by vapor deposition or sputtering, Further, it can be formed by peeling the mask member using a peeling solution (ie, lift-off method).
Further, for the purpose of applying a bias magnetic field to the element part or the magnetic converging part, a wiring part that is not connected to the element part may be provided separately.

(E) Electrode An electrode is used for connection with an external circuit or the like. From the viewpoint of adhesion, it is desirable to provide a layer such as Ti or Ta between the substrate and the electrode. The element portion may be left on the substrate, and an electrode may be formed on the upper portion. The material of the electrode is not particularly limited as long as it is a conductive material (for example, Au, Cu, Cr, Ni, Al, Ta, Ru, etc.) as in the wiring portion. Au, Ru, etc.) are preferred.

  Further, the electrode may be made of a single material, or may be a mixture or a laminate of a plurality of materials. The electrode can be formed by a known method, for example, a mask member formed by a photolithography method, and a conductive material is formed on the entire surface of the stacked portion by an evaporation method or a sputtering method. It can be formed by peeling the mask member using a peeling solution (that is, lift-off method). From the viewpoint of process man-hours, it is desirable to make the same process as the wiring part.

(F) Hard Bias Unit By forming the hard bias unit so that the magnetic field from the hard bias unit is applied in the direction perpendicular to the magnetosensitive axis of the element unit, the Barkhausen noise suppression effect and the linearity improvement effect Is obtained. The magnetic sensor of one embodiment of the present invention may or may not include a hard bias portion. As the material of the hard bias portion, for example, a ferromagnetic material having a large hysteresis such as CoPt or CoPtCr is used, but the material is not limited to this.

The hard bias part may be formed so that a magnetic field is applied to both the element part and the magnetic converging part as shown in FIG. 5A, or the magnetic converging part as shown in FIG. 5B. The magnetic field may be applied only to the part, or the magnetic field may be applied only to the element part as shown in FIG.
In FIG. 5A, the upper hard bias portion of the element portion 20 and the magnetic converging portions 30L and 30R in FIG. 5 is the hard bias portion 60U, and the lower hard bias portion is the hard bias portion 60B. In FIG. 5B, the hard bias units 601U and 602U on the upper side of the magnetic converging units 30L and 30R in FIG. 5 are used as the hard bias units 601U and 602U, and the lower hard bias units are used as the hard bias units 601B and 602B. In FIG. 5C, the upper hard bias portion of the element portion 20 in FIG. 5 is the hard bias portion 60U, and the lower hard bias portion is the hard bias portion 60B.

[Embodiment]
Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description of the drawings, the same portions are denoted by the same reference numerals. However, the drawings are schematic, and the relationship between the thickness and the planar dimensions, the ratio of the thickness of each layer, and the like are different from the actual ones. Further, the present invention is not limited to the embodiment shown below. In the embodiment described below, a technically preferable limitation is made for carrying out the present invention, but this limitation is not an essential requirement of the present invention.

<First embodiment>
As shown in FIG. 1, the magnetic sensor 1 of the first embodiment is formed on a substrate 10, an element unit 20 disposed on the substrate 10, a protective layer 40 covering the element unit 20, and the protective layer 40. A wiring part 50 connected to the element part 20 through the energization window 40a, and a protective layer 41 covering the wiring part 50 and the protective layer 40, and further, a seed layer 31 and magnetic converging parts 30L, 30R on the protective layer 41. Is provided. The magnetic converging unit 30L is a magnetic converging unit on the left side of the element unit 20 on the paper surface of FIG. 1, and the magnetic converging unit 30R is a right magnetic converging unit. The magnetic flux concentrators 30L and 30R are arranged so as to sandwich the element unit 20 in a direction parallel to the magnetosensitive axis of the element unit 20.

The element unit 20 is formed by laminating a magnetization free layer 21, a nonmagnetic layer 22, and a magnetization fixed layer 23 in this order. From the nonmagnetic layer 22 and the magnetization fixed layer 23 on one magnetization free layer 21. The plurality of stacked bodies are arranged along a line that is substantially orthogonal to the first direction (the direction of the magnetosensitive axis of the element unit 20) among the sides that define the magnetic converging unit 30.
The length LFC in the first direction of the magnetic focusing portions 30L and 30R is 5 mm or more, the thickness tFC of the magnetic focusing portions 30L and 30R is 5 μm or more, and satisfies LFC> tFC. Further, the length LFC in the first direction of the magnetic flux concentrators 30L and 30R is longer than the length WFC in the third direction.

The distance DFC between the two magnetic focusing portions 30L and 30R, the length LFMR in the first direction of the magnetization free layer 21, the length LPMR in the first direction of the magnetization fixed layer 23, and the magnetic focusing portions 30L and 30R The thickness tFC satisfies LPMR / 4 ≦ DFC ≦ LFMR + 5 × tFC. The length LFMR in the first direction of the magnetization free layer 21 satisfies 50 μm ≦ LFMR ≦ 150 μm.
Further, the center of the magnetic flux concentrators 30L and 30R in the thickness direction is shifted from the center of the element unit 20 in the thickness direction.

  FIG. 2 shows a modification of the first embodiment. In this magnetic sensor 1, a part of the magnetization free layer 21 and part of the magnetic converging parts 30 </ b> L and 30 </ b> R constituting the element part 20 are viewed from above. It arrange | positions so that it may have an overlap part. The magnetic sensor 1 of FIG. 1 and the magnetic sensor 1 of FIG. 2 have the same distance DFC between the magnetic converging portions 30L and 30R, but the dimension LFMR of the magnetization free layer 21 in the first direction is the magnetic sensor 1 of FIG. 2 is larger than the magnetic sensor 1 in FIG.

The manufacturing method of the magnetic sensor of a first embodiment is shown. The manufacturing method shown below is an example, and it is not always necessary to manufacture the manufacturing method by the following method.
First, a laminated film composed of a ferromagnetic layer and a nonmagnetic layer is formed on the substrate 10 by a known method such as sputtering. Next, a mask member is formed on the laminated film by a photolithography method or the like. The mask member may be formed in a desired shape at a desired location on the laminated film.

Next, the portion of the laminated film not covered with the mask member is etched by a known method such as ion milling. Thereby, the laminated film on the substrate 10 is processed into a desired planar shape. At this time, there may be a plurality of laminated films (laminates) processed into a desired planar shape in the plane of the substrate 10.
Next, a mask member is formed on the laminated portion by a photolithography method or the like. At this time, the opening of the mask member is formed to be smaller than the plane area of the laminated portion. Next, the laminated portion not covered with the mask member is etched by a known method such as ion milling. At this time, etching is stopped in the vicinity of the nonmagnetic layer of the “ferromagnetic layer / nonmagnetic layer / ferromagnetic layer” structure present in the laminated film. At this time, the lower ferromagnetic layer may be partially etched. Thereby, the dimension in the first direction of the nonmagnetic layer / ferromagnetic layer on the side opposite to the substrate 10 is formed smaller than that of the ferromagnetic layer on the substrate 10 side. As a result, the element portion 20 including the magnetization free layer 21 made of a ferromagnetic layer, the nonmagnetic layer 22, and the magnetization fixed layer 23 made of a ferromagnetic layer is formed on the substrate 10.

Next, an insulating film is formed on the element portion 20 by a known method such as a CVD method. A mask member is formed on the insulating film by a photolithography method or the like. Further, the insulating film is etched by a known method such as RIE to form an opening for the energizing window 40a. Thereby, the protective layer 40 having the energization window 40a is formed.
Next, a mask member is formed on the protective layer 40 by a photolithography method or the like. Further, a metal thin film is formed by a known method such as sputtering, and the wiring member 50 and the electrode 51 are formed at the same time by removing the mask member and the metal thin film on the mask member.

Next, an insulating film for the protective layer 41 is formed by a known method such as a CVD method, and a seed layer 31 serving as a plating base is formed by a known method such as a sputtering method. Further, a mask member is formed on the seed layer 31 by a photolithography method or the like.
Next, by forming a plating film on the opening of the mask member by a known method such as electrolytic plating, the mask members are removed after the magnetic converging portions 30L and 30R are formed. Next, the seed layer 31 and the protective layer 41 (other than the portion existing between the magnetic focusing portions 30L and 30R and the protective layer 40) covering the entire surface are removed by a known method such as ion milling. Through the above steps, the magnetic sensor 1 of the present embodiment shown in FIGS. 1 and 2 can be obtained.

<Second embodiment>
As shown in FIG. 3, the magnetic sensor 1 of the second embodiment is formed on the substrate 10, the element unit 20 and the magnetic focusing units 300 </ b> L and 300 </ b> R disposed on the substrate 10, and the magnetic focusing units 300 </ b> L and 300 </ b> R, respectively. The magnetic convergence portions 30L and 30R, the protective layer 40, and the wiring portion 50 are provided. The magnetic converging units 300L and 300R and the magnetic converging units 30L and 30R are arranged so as to sandwich the element unit 20 in a direction parallel to the magnetosensitive axis of the element unit 20, and are insulated from the element unit 20. The magnetic converging units 30L and 300L are the magnetic converging units on the left side of the element unit 20 on the paper surface of FIG. 3, and the magnetic converging units 30R and 300R are the right magnetic converging units.

The element unit 20 and the magnetic flux concentrators 300L and 300R are covered with a protective layer 40. The magnetic converging portions 30L and 30R are covered with the protective layer 40 on the magnetic converging portions 300L and 300R side, and the other portions protrude from the protective layer 40. The wiring part 50 is connected to the element part 20 through an energization window 40 a formed in the protective layer 40.
The element unit 20 is formed by laminating a magnetization free layer 21, a nonmagnetic layer 22, and a magnetization fixed layer 23 in this order. From the nonmagnetic layer 22 and the magnetization fixed layer 23 on one magnetization free layer 21. A plurality of stacked bodies are arranged along a line that is substantially orthogonal to the first direction among the sides defining the magnetic flux concentrator 30.

  The length LFC in the first direction of the magnetic focusing portions 30L and 30R is 5 mm or more, and the total thickness tFC of the magnetic focusing portions 30L and 30R and the magnetic focusing portions 300L and 300R is 5 μm or more and satisfies LFC> tFC. The length LFC in the first direction of the magnetic flux concentrators 30L and 30R is longer than the length WFC in the third direction. Moreover, the length of the magnetic convergence parts 300L and 300R in the first direction is longer than the length in the third direction. In addition, the length of the magnetic converging portions 300L and 300R in the first direction is slightly longer than the length LFC of the magnetic converging portions 30L and 30R in the first direction. The length in the third direction of the magnetic converging portions 300L and 300R is slightly shorter than the length of the magnetic converging portions 30L and 30R in the third direction.

The distance DFC between the two magnetic focusing portions 30L and 30R, the length LFMR in the first direction of the magnetization free layer 21, the length LPMR in the first direction of the magnetization fixed layer 23, and the thickness tFC of the magnetic focusing portion are: LPMR / 4 ≦ DFC ≦ LFMR + 5 × tFC is satisfied. The length LFMR in the first direction of the magnetization free layer 21 satisfies 50 μm ≦ LFMR ≦ 150 μm.
Further, the center of the magnetic flux concentrators 30L and 30R in the thickness direction is shifted from the center of the element unit 20 in the thickness direction.

The magnetic sensor of the second embodiment can be manufactured by the same method as the magnetic sensor of the first embodiment.
However, in the magnetic sensor of the second embodiment, a desired plane is obtained by etching a laminated film composed of a ferromagnetic layer and a nonmagnetic layer, which is created by a known method such as sputtering, by a known method such as ion milling. When processing into a shape, the element part 20 and the magnetic converging parts 300L and 300R are formed simultaneously.

Specifically, first, a stacked portion for the element portion 20 and a stacked portion for the magnetic convergence portions 300L and 300R are formed by the first etching. Next, the ferromagnetic layers that are the same layer as the magnetization free layer 21 are left on the left and right sides of the magnetization free layer 21 of the element portion 20 by etching with respect to each stacked portion. This ferromagnetic layer becomes the magnetic convergence portions 300L and 300R.
Thereafter, the magnetic converging portions 30L and 30R are formed on the magnetic converging portions 300L and 300R.

<Third embodiment>
As shown in FIG. 4, the magnetic sensor 1 of the third embodiment has a larger area of the magnetization free layer 21 than the magnetic sensor 1 shown in FIG. The interval DFC is also large. A plurality of nonmagnetic layers 22 / magnetization pinned layers 23 formed on one magnetization free layer 21 are arranged along a line substantially parallel to the first direction among the sides defining the magnetic converging portion 30. ing. The rest is the same as the magnetic sensor 1 shown in FIG. 1 of the first embodiment.

<Fourth embodiment>
The magnetic sensor 1 of the fourth embodiment has hard bias units 60U and 60B in the arrangement shown in FIG. That is, the hard bias portions 60U and 60B are in a direction (third direction) orthogonal to the magnetosensitive axis (first direction) of the element portion 20 and the thickness direction (second direction) of the magnetic converging portions 30L and 30R. Thus, they are arranged so as to sandwich the element part 20 and the magnetic converging parts 30L and 30R. The rest is the same as the magnetic sensor 1 of the first embodiment.

  When manufacturing this magnetic sensor, first, the magnetic converging portions 30L and 30R are formed by the same process as the magnetic sensor of the first embodiment. Thereafter, a mask member having openings at positions on both sides of the element portion 20 and the magnetic converging portions 30L and 30R in the third direction is formed by a photolithography method or the like, and a known method such as sputtering is formed on the mask member. Then, a ferromagnetic thin film is formed. Next, by removing this mask member, the ferromagnetic thin film remains on both sides of the element portion 20 and the magnetic converging portions 30L and 30R. Thereby, the hard bias portions 60U and 60B are formed. At the time of film formation, the magnetization direction of the hard bias portion can be determined by applying a magnetic field in a desired direction.

Hereinafter, examples and comparative examples will be described. In the following examples and comparative examples, magnetic sensors were formed by changing the length and thickness of the magnetic converging unit 30, and the magnetic sensitivity was examined.
In addition, the magnetic simulation was performed by changing the length and thickness of the magnetic converging portion 30, and the magnetic gain corresponding to the magnetic sensitivity was examined.

[Examination of magnetic sensitivity]
[Production of magnetic sensor]
<Example 1>
As the magnetic sensor 1 having the structure shown in FIG. 1, the magnetic converging portions 30L and 30R and the element portion 20 in a plan view having the arrangement shown in FIG. 6 were manufactured through the following film forming and microfabrication processes.

First, Ta as a seed layer, NiFe, Ru, CoFeB as a magnetization free layer 21, MgO as a nonmagnetic layer 22, and CoFeB, Ru as a magnetization fixed layer 23 on a substrate 10 having a surface of about ₂ μm of SiO ₂ formed thereon. By laminating CoFe, IrMn, and Ta and Ru as a cap layer in this order, a laminated film was formed.
Next, a first mask member having a plurality of openings for forming a laminated portion for the element portion 20 was formed on the laminated film by photolithography. Next, using the ECR plasma etching apparatus, the laminated film not covered with the first mask member was removed, and a plurality of laminated parts for the element part 20 were formed. Thereafter, the first mask member was removed.

  Next, a second mask member having two openings for forming the magnetization fixed layer 23 was formed on all the stacked portions by photolithography. Next, the laminated film not covered with the second mask member was removed up to the nonmagnetic layer 22 using an ECR plasma etching apparatus. Thereby, a plurality of element portions 20 were formed on the substrate 10. Thereafter, the second mask member was removed.

Next, a protective film 40 made of SiO ₂ was formed on the substrate 10 on which the plurality of element portions 20 were formed. Next, in order to manufacture the energization window 40a, a third mask member was formed on the protective film 40 by photolithography to expose only the vicinity of the center of all the magnetization fixed layers 23 and cover the other regions. And the part exposed from the 3rd mask member of the protective film 40 was etched using the RIE etching apparatus. Thereby, the energization window 40a for connection with a wiring part was formed in the protective layer 40. Thereafter, the third mask member was removed.

  Next, a fourth mask member that exposes a region where a wiring portion that connects each energization window 40a in series and a region where an electrode is formed is exposed by photolithography and covers the other region Was formed on the protective layer 40. Next, a metal film was laminated on the entire surface using a magnetron sputtering apparatus. Thereafter, the fourth mask member was removed by a lift-off method, and the wiring part 50 and the electrode 51 were formed from the metal film.

Next, using a heat treatment apparatus in a magnetic field, heat treatment was performed at 325 ° C. for 1 hour (first heat treatment) while applying a magnetic field in a plane direction perpendicular to the magnetosensitive axis, and the temperature was cooled to 100 ° C. while the magnetic field was applied. Thereafter, heat treatment (second heat treatment) was performed at 325 ° C. for 1 hour while applying a magnetic field in a direction parallel to the magnetosensitive axis, and the temperature was cooled to 100 ° C. or less while the magnetic field was applied.
Next, after forming a protective layer 41 made of SiO _{2 on} the entire surface, a seed layer 31 made of Ta / Cu was laminated using a magnetron sputtering apparatus. Further, a fifth mask member that covers a region other than the regions where the magnetic converging portions 30R and 30L are formed (regions on both sides of the element portion 20) is formed on the seed layer 31 by photolithography.

Next, the magnetic converging portions 30R and 30L made of NiFe are formed on the seed layer 31 in the opening of the fifth mask member by electrolytic plating while applying a magnetic field in a direction perpendicular to the magnetosensitive axis in a top view. did. At this time, the average value of the thickness of the magnetic converging portion is 10 μm, the length LFC in the first direction (the direction parallel to the magnetosensitive axis) is 10 mm, and the length WFC in the third direction is 1.5 mm. Formed.
Thereafter, the fifth mask member was removed by a lift-off method, and the excess seed layer 31 was removed using an etching apparatus, whereby the magnetic sensor 1 was obtained.
While applying a voltage of 1 V to the obtained magnetic sensor 1, it was applied while changing the external magnetic field from the magnetosensitive axis direction, and the change in magnetoresistance was measured.

<Example 2>
The magnetic sensor 1 having the structure shown in FIG. 1 has three magnetic converging portions 30L, 30R, and 30C and two element portions 20L and 20R, and the magnetic converging portions 30L, 30R, and 30C and the element portion 20L in plan view. The arrangement of 20R shown in FIG. 7 was produced in the same manner as in Example 1. The average value of the thickness of the magnetic converging portion was 10 μm, the length LFC in the first direction (the direction parallel to the magnetosensitive axis) was 5 mm, and the length WFC in the third direction was 1.4 mm. The magnetic resistance change of the obtained magnetic sensor 1 was measured by the same method as in Example 1.

<Comparative Example 1>
A magnetic sensor having the same structure as that of FIG. 1 was produced in the same manner as in Example 1 except that the arrangement of the magnetic focusing portions 30L and 30R and the element portion 20 in plan view is shown in FIG. The average value of the thickness of the magnetic converging portion was 10 μm, the length LFC in the first direction (the direction parallel to the magnetosensitive axis) was 0.85 mm, and the length WFC in the third direction was 1.4 mm. . The magnetic resistance change of the obtained magnetic sensor 1 was measured by the same method as in Example 1.

<Comparative Example 2>
A magnetic sensor having the same structure as that of FIG. 1 was produced in the same manner as in Example 1 except that the arrangement of the magnetic focusing portions 30L and 30R and the element portion 20 in plan view is shown in FIG. The average value of the thickness of the magnetic converging portion was 10 μm, the length LFC in the first direction (the direction parallel to the magnetosensitive axis) was 0.55 mm, and the length WFC in the third direction was 0.96 mm. . The magnetic resistance change of the obtained magnetic sensor 1 was measured by the same method as in Example 1.

<Comparative Example 3>
The magnetic sensor of Comparative Example 3 is shown in FIG. 8 in which the arrangement of the element part and the two magnetic converging parts in plan view is the same as in Comparative Example 1, but the magnetic converging part is directly formed on the substrate 10. Have That is, the magnetic sensor of Comparative Example 2 is the magnetic sensor 1 of FIG. 3 and does not have the magnetic focusing portions 30L and 30R, but has a cross-sectional shape in which the upper surfaces of the magnetic focusing portions 300L and 300R are covered with the protective layer 40. . The length LFC in the first direction of the magnetic flux concentrators 300L and 300R of the magnetic sensor of Comparative Example 3 is 0.55 mm, the thickness is 0.07 μm, and the length WFC in the third direction is 0.96 mm.

The magnetic sensor of Comparative Example 3 was produced by the following method.
First, after forming the laminated film on the substrate 10 in the same manner as in Example 1, a first mask member was formed on the laminated film by photolithography. This mask member has an opening for forming a stacked portion for the plurality of element portions 20 and an opening for forming a stacked portion for a magnetic converging portion. Next, using the ECR plasma etching apparatus, the laminated film not covered with the first mask member was removed, and a laminated part for the plurality of element parts 20 and a laminated part for the magnetic convergence part were formed at the same time. Thereafter, the first mask member was removed.

  Next, a second mask member having two openings for forming the magnetization fixed layer 23 was formed on all the stacked portions for the element portions 20 by photolithography. Next, the multilayer film not covered with the second mask member was removed to the nonmagnetic layer using an ECR plasma etching apparatus. As a result, a plurality of element portions 20 and magnetic converging portions 300L and 300R were formed on the substrate 10. Thereafter, the second mask member was removed.

Next, a protective film 40 made of SiO ₂ was formed on the substrate 10 on which the element unit 20 and the magnetic flux concentrators 300L and 300R were formed. Next, a third mask member was formed on the protective film 40 to expose only the vicinity of the center of all the magnetization fixed layers 23 and cover other regions by photolithography for the production of the energization window 40a. Then, the portion of the protective film 40 not covered with the third mask member was etched using an RIE etching apparatus. Thereby, the energization window 40a for connection with a wiring part was formed in the protective layer 40. Thereafter, the third mask member was removed.

  Next, a fourth mask member that exposes a region where a wiring portion that connects each energization window 40a in series and a region where an electrode is formed is exposed by photolithography and covers the other region Was formed on the protective layer 40. Next, a metal film was laminated on the entire surface using a magnetron sputtering apparatus. Thereafter, the fourth mask member was removed by a lift-off method, and the wiring portion 50 and the electrode were formed from the metal film.

Next, using a heat treatment apparatus in a magnetic field, heat treatment was performed at 325 ° C. for 1 hour (first heat treatment) while applying a magnetic field in a plane direction perpendicular to the magnetosensitive axis, and the temperature was cooled to 100 ° C. while the magnetic field was applied. Thereafter, a heat treatment (second heat treatment) is performed at 325 ° C. for 1 hour while applying a magnetic field in a direction parallel to the magnetosensitive axis, and the magnetic field of Comparative Example 2 is reduced by cooling to 100 ° C. or less while the magnetic field is applied. A sensor was obtained.
While applying a voltage of 1 V to the obtained magnetic sensor, it was applied while changing the external magnetic field from the magnetosensitive axis direction, and the change in magnetoresistance was measured.

[Sensitivity comparison]
The principle of the resistance change of the magnetic sensor is based on the TMR effect (Tunnel Magneto Resistance effect) which is already known. The change in resistance value due to the TMR effect is due to a change in the relative angle between the magnetization of the magnetization free layer and the magnetization of the magnetization fixed layer, and the resistance changes at these interfaces. As is well known, the sensitivity of a TMR sensor or the like is defined as follows. When the relative angle of magnetization is 0 °, the resistance value is Rp, the resistance value when it is 180 ° is Rap, and the resistance change range is 2Hk. Is expressed by the following equation (1).

実施例１の磁気センサの感度は８６９［％／Ｏｅ］、実施例２の磁気センサの感度は６３８［％／Ｏｅ］、比較例１の磁気センサの感度は１１８［％／Ｏｅ］、比較例２の磁気センサの感度は７７［％／Ｏｅ］、比較例３の磁気センサの感度は２５[％／Ｏｅ]となった。

The sensitivity of the magnetic sensor of Example 1 is 869 [% / Oe], the sensitivity of the magnetic sensor of Example 2 is 638 [% / Oe], the sensitivity of the magnetic sensor of Comparative Example 1 is 118 [% / Oe], and the Comparative Example The sensitivity of the magnetic sensor No. 2 was 77 [% / Oe], and the sensitivity of the magnetic sensor of Comparative Example 3 was 25 [% / Oe].

  The length LFC in the first direction of the magnetic converging portion is 10 mm in the magnetic sensor of the first embodiment and 5 mm in the magnetic sensor of the second embodiment, whereas it is 0 in the magnetic sensors of the first, second, and third comparative examples. .85 mm and 0.55 mm (less than 5 mm). This difference seems to have caused a large difference in the sensitivity of the magnetic sensor.

[Magnetization characteristics]
VSM measurement was performed on the magnetic sensor of Example 1. The magnetization was calibrated with a Ni plate, and the dependence of the magnetization of the magnetic sensor 1 when a magnetic field of ± 50 Oe was applied was measured. Since the magnetic converging unit 30 occupies 99.9% or more of the volume of the magnetic material constituting the magnetic sensor 1, the measurement result can be regarded as the magnetization characteristic of the magnetic converging unit 30.

The obtained magnetization curve is shown in FIG. 9 with the vertical axis indicating magnetization [emu / cc] and the horizontal axis indicating external magnetic field [Oe]. The magnetization increased rapidly after the external magnetic field increased rapidly to around 6 [Oe], and the magnetization value was saturated at 1750 [emu / cc]. When the value of the saturation magnetic field was approximately calculated from the extrapolation line of the magnetization gradient of 1 to 2 [Oe] and the saturation magnetization value, it was 7.4 [Oe].
Here, the magnetic permeability that determines the magnetic amplification factor is expressed by magnetic flux density / external magnetic field. The magnetic permeability of the magnetic converging unit 30 of the magnetic sensor 1 was a maximum value of 2800 in the vicinity of 6 [Oe].

[Magnetic simulation]
In Examples 11 to 92 and Comparative Examples 11 to 82 shown below, a magnetic field analysis simulation by a finite element method was performed.
In the magnetic field analysis simulation, a magnetic body having an arbitrary shape and magnetic permeability can be produced on a computer. When a magnetic material having a defined shape is divided into small regions of arbitrary size and a magnetic field is applied, the magnetization state of each small region in the magnetic material can be calculated. The magnitude of the magnetization value of the magnetic material corresponds to the sensitivity gain.

  Then, the arrangement of the magnetic body groups is shown in FIG. 10 with respect to the magnetic bodies 30L ′ and 30R ′ corresponding to the magnetic converging portions 30L and 30R, the magnetic body 21 ′ corresponding to the magnetization free layer 21, and the magnetization fixed layer 23. It is defined as an arrangement composed of corresponding magnetic sensitive areas, and the magnetization of the magnetic sensitive area when the magnetic converging portions 30L ′ and 30R ′ are present is the magnetization of the magnetic sensitive area when the magnetic converging portions 30L ′ and 30R ′ are absent. On the other hand, we investigated how many times it was. This value is defined as “amplification factor” in this specification.

[Analysis 1]
<Example 11 to Example 15>
In the following, the side extending in the magnetic field application direction is described as “length”, the side in the thickness direction is referred to as “thickness”, and the side extending in the direction perpendicular to both the length and thickness is described as “width”. The magnetic body 21 ′ corresponding to the magnetization free layer 21 of the magnetic sensor 1 was arranged with a length of 100 μm, a width of 140 μm, a thickness of 0.1 μm, and a magnetic permeability of 2000. The magnetic bodies 30L ′ and 30R ′ corresponding to the magnetic converging portions 30L and 30R of the magnetic sensor 1 are arranged on a plane that is 1 μm away from the center of the magnetic body 21 ′ in the thickness direction, the width is 750 μm, the thickness is 5 μm, and the magnetic permeability. 2000, respectively, on the left side and the right side of the magnetic body 21 ′. Further, the magnetic sensitive area was defined with a length of 60 μm and a width of 14 μm at the center in the magnetic body 21 ′.

Here, the length of the magnetic body 30 ′ (magnetic bodies 30L ′, 30R ′) varies depending on each embodiment, and is 5 mm in Example 11, 7.5 mm in Example 12, 10 mm in Example 13, and in Example 14. 15 mm and 20 mm in Example 15.
At this time, the gap between the left end of the magnetic body 21 ′ and the right end of the magnetic body 30L ′ and the gap between the right end of the magnetic body 21 ′ and the left end of the magnetic body 30R ′ are arranged 5 μm apart.

  A magnetic field of 0.1 nT was applied from the left side to the magnetic body 21 ′ and the magnetic bodies 30 </ b> L ′ and 30 </ b> R ′ arranged as described above to obtain the amplification factor.

<Examples 21 to 25>
In Examples 21 to 25, the amplification factor was obtained in the same manner as in Example 11 except that the thickness of the magnetic body 30 ′ was 10 μm and the length of the magnetic body 30 ′ was as follows.
The length of the magnetic body 30 ′ was 5 mm in Example 21, 7.5 mm in Example 22, 10 mm in Example 23, 15 mm in Example 24, and 20 mm in Example 25.

<Examples 31-35>
In Examples 31 to 35, the amplification factor was obtained in the same manner as in Example 11 except that the thickness of the magnetic body 30 ′ was 30 μm and the length of the magnetic body 30 ′ was as follows.
The length of the magnetic body 30 ′ was 5 mm in Example 31, 7.5 mm in Example 32, 10 mm in Example 33, 15 mm in Example 34, and 20 mm in Example 35.

<Examples 41 to 45>
In Examples 41 to 45, the amplification factor was obtained in the same manner as in Example 11 except that the thickness of the magnetic body 30 ′ was 50 μm and the length of the magnetic body 30 ′ was as follows.
The length of the magnetic body 30 ′ was 5 mm in Example 41, 7.5 mm in Example 42, 10 mm in Example 43, 15 mm in Example 44, and 20 mm in Example 45.

<Examples 51-55>
In Examples 51 to 55, the amplification factor was obtained in the same manner as in Example 11 except that the thickness of the magnetic body 30 ′ was 100 μm and the length of the magnetic body 30 ′ was as follows.
The length of the magnetic body 30 ′ was 5 mm in Example 51, 7.5 mm in Example 52, 10 mm in Example 53, 15 mm in Example 54, and 20 mm in Example 55.

<Examples 61 to 64>
In Examples 61 to 64, the amplification factor was obtained in the same manner as in Example 11 except that the width of the magnetic body 30 ′ was changed as follows.
The width of the magnetic body 30 ′ was 3 mm in Example 61, 5 mm in Example 62, 7 mm in Example 63, and 10 mm in Example 64.

<Comparative Examples 11-12>
In Comparative Examples 11 to 12, the thickness of the magnetic body 30 ′ was 5 μm, and the length of the magnetic body 30 ′ was 1 mm in Comparative Example 11 and 2.5 mm in Comparative Example 12, except that it was the same as Example 11. The amplification factor was obtained by the method.
<Comparative Examples 21-22>
In Comparative Examples 21 to 22, the thickness of the magnetic body 30 ′ was 10 μm, and the length of the magnetic body 30 ′ was 1 mm in Comparative Example 21 and 2.5 mm in Comparative Example 22 except that it was the same as Example 11 The amplification factor was obtained by the method.

<Comparative Examples 31-32>
Comparative Examples 31 to 32 are the same as Example 11 except that the thickness of the magnetic body 30 ′ is 30 μm, and the length of the magnetic body 30 ′ is 1 mm in Comparative Example 31 and 2.5 mm in Comparative Example 32. The amplification factor was obtained by the method.
<Comparative Examples 41-42>
In Comparative Examples 41 to 42, the thickness of the magnetic body 30 ′ was 50 μm, and the length of the magnetic body 30 ′ was 1 mm in Comparative Example 41 and 2.5 mm in Comparative Example 42, as in Example 11. The amplification factor was obtained by the method.

<Comparative Examples 51-52>
In Comparative Examples 51 to 52, the thickness of the magnetic body 30 ′ was set to 100 μm, and the length of the magnetic body 30 ′ was set to 1 mm in Comparative Example 51 and 2.5 mm in Comparative Example 52. The amplification factor was obtained by the method.
<Comparative Examples 61-67>
In Comparative Examples 61 to 67, the amplification factor was obtained in the same manner as in Example 11 except that the thickness of the magnetic body 30 ′ was 0.1 μm and the length of the magnetic body 30 ′ was as follows.
The length of the magnetic body 30 ′ is 1 mm in Comparative Example 61, 2.5 mm in Comparative Example 62, 5 mm in Comparative Example 63, 7.5 mm in Comparative Example 64, 10 mm in Comparative Example 65, 15 mm in Comparative Example 66, In Example 67, it was 20 mm.

<Comparative Examples 71-77>
In Comparative Examples 71 to 77, the amplification factor was obtained in the same manner as in Example 11 except that the thickness of the magnetic body 30 ′ was 1 μm and the length of the magnetic body 30 ′ was as follows.
The length of the magnetic body 30 ′ is 1 mm in Comparative Example 71, 2.5 mm in Comparative Example 72, 5 mm in Comparative Example 73, 7.5 mm in Comparative Example 74, 10 mm in Comparative Example 75, 15 mm in Comparative Example 76, Comparative In Example 77, it was 20 mm. Next, Comparative Examples 71 to 77 will be described.

<Comparison of gain depending on length and thickness of magnetic convergence part>
The length (referred to as LFC) of the magnetic body 30 ′ of Examples 11 to 55 and Comparative Examples 11 to 77, the thickness of the magnetic body 30 ′ (referred to as tFC), and the feeling of the magnetic body 21 ′. Table 1 summarizes the relationship between the gains in the magnetic area.
The obtained results are shown in the graph of FIG. 11 in which the length of the magnetic body 30 ′ in the magnetosensitive axis direction is the horizontal axis and the gain is the vertical axis. In FIG. 11, the plot mark is changed for each thickness in the comparative example and the example.

Next, the width (WFC) of the magnetic body 30 ′, the length (LFC) of the magnetic body 30 ′ in the magnetic axis direction, and the magnetic sensitive area of the magnetic body 21 ′ in Example 11 and Examples 61 to 64. Table 2 shows the amplification factor.
Further, the obtained results are shown in the graph of FIG. 12 in which the width of the magnetic body 30 ′ is the horizontal axis and the gain is the vertical axis.

表１および図１１から、実施例では比較例に対して効果を示していることが分かる。

From Table 1 and FIG. 11, it can be seen that the example shows an effect over the comparative example.

表２および図１２から、幅ＷＦＣが５ｍｍよりも小さい時、すなわち、幅ＷＦＣ＜長さＬＦＣであるとき、より高い感度増幅効果が得られることが分かる。

From Table 2 and FIG. 12, it can be seen that when the width WFC is smaller than 5 mm, that is, when the width WFC <the length LFC, a higher sensitivity amplification effect can be obtained.

[Analysis 2]
<Examples 81-92>
In Examples 81-92, amplification factors were obtained in the same manner as in Example 11 except that the interval between the magnetic body 30L ′ and the magnetic body 30R ′ was changed as follows.
The distance between the magnetic body 30L ′ and the magnetic body 30R ′ is 15 μm in Example 81, 20 μm in Example 82, 30 μm in Example 83, 40 μm in Example 84, 50 μm in Example 85, and 60 μm in Example 86. Example 87 was 70 μm, Example 88 was 80 μm, Example 89 was 100 μm, Example 90 was 110 μm, Example 91 was 120 μm, and Example 92 was 125 μm.

<Comparative Examples 81-82>
In Comparative Examples 81 to 82, amplification factors were obtained in the same manner as in Example 11 except that the interval between the magnetic body 30L ′ and the magnetic body 30R ′ was 10 μm in Comparative Example 81 and 130 μm in Comparative Example 82.

また、得られた結果を、ＤＦＣを横軸、増幅率を縦軸とした図１３のグラフに示す。
表３および図１３より、ＤＦＣが１５（ＬＰＭＲ／４）以上１２５（ＬＦＭＲ＋５×ｔＦＣ）以下の範囲の中央値に近いほど、得られる効果が大きいことが分かる。 <Comparison of gain depending on magnetic converging part spacing and magnetization free layer length>
Table 3 summarizes the relationship between the distance between the magnetic bodies 30L ′ and 30R ′ (referred to as DFC) in Examples 81 to 92 and Comparative Examples 81 to 82 and the gain in the magnetic sensitive area of the magnetic body 21 ′.

The obtained results are shown in the graph of FIG. 13 with DFC as the horizontal axis and amplification factor as the vertical axis.
From Table 3 and FIG. 13, it can be seen that the closer the DFC is to the median value in the range of 15 (LPMR / 4) to 125 (LFMR + 5 × tFC), the greater the effect obtained.

DESCRIPTION OF SYMBOLS 1 Magnetic sensor 10 Board | substrate 20 Element part 21 Magnetization free layer 21 'Magnetic body 22 corresponding to a magnetization free layer 22 Nonmagnetic layer 23 Magnetization fixed layer 30 Magnetic convergence part 30L Magnetic convergence part (left side)
30R Magnetic convergence part (right side)
30L 'Magnetic body 30R' corresponding to magnetic converging part 30L Magnetic body 31 corresponding to magnetic converging part 30R Seed layer 40 Protective layer 41 Protective layer 40a Conducting window 50 Wiring part 51 Electrode 60 Hard bias part 60U Hard bias part (upper side)
60B Hard bias section (lower side)

Claims (11)

An element portion having a magnetization free layer, an insulating nonmagnetic layer formed on the magnetization free layer, and a magnetization fixed layer formed on the nonmagnetic layer;
A magnetic converging part electrically insulated from the element part,
When the direction of the magnetosensitive axis of the element portion is the first direction,
The length LFC in the first direction of the magnetic converging part is 5 mm or more,
The thickness tFC of the magnetic converging part is 5 μm or more,
Magnetic sensor satisfying LFC> tFC.   The magnetic sensor according to claim 1, comprising a plurality of the magnetic converging units, wherein the element unit exists between the plurality of magnetic converging units.   The distance DFC between the plurality of magnetic focusing portions, the length LFMR of the magnetization free layer in the first direction, the length LPMR of the magnetization fixed layer in the first direction, and the thickness tFC of the magnetic focusing portion The magnetic sensor according to claim 2, wherein LPMR / 4 ≦ DFC ≦ LFMR + 5 × tFC is satisfied. When the thickness direction of the magnetic converging portion is the second direction, and the first direction and the direction perpendicular to the second direction are the third direction,
4. The magnetic sensor according to claim 2, wherein two or more of the plurality of magnetic converging portions have a length LFC in the first direction longer than a length WFC in the third direction.   The magnetic sensor according to claim 1, wherein an area of the magnetization free layer is larger than an area of the magnetization fixed layer in a top view. A plurality of the element portions having a plurality of the magnetization fixed layers,
The magnetic sensor as described in any one of Claims 1-5 which has a wiring part which electrically connects the said some element part.   The magnetic sensor according to claim 6, wherein the plurality of element portions are arranged along a side that is substantially orthogonal to the first direction among the sides that define the magnetic convergence unit.   The magnetic sensor according to claim 1, wherein a length LFMR of the magnetization free layer in the first direction satisfies 50 μm ≦ LFMR ≦ 150 μm.   The magnetic sensor according to claim 1, wherein a center in the thickness direction of the magnetic converging portion and a center in the thickness direction of the element portion are deviated.   10. The length of the element unit in a direction orthogonal to the first direction is shorter than a length of the magnetic focusing unit in a direction orthogonal to the first direction. Magnetic sensor. 11. The magnetic sensor according to claim 1, wherein the value Hs of the external magnetic field when the magnetization in the first direction of the magnetic focusing unit is saturated satisfies 0 <Hs ≦ 10 [Oe].

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