JP2003008108A - Magnetic detecting element and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a CPP type magnetic detecting element that generates high reproduction outputs and has not been able to be manufactured by the conventional lithographic technique. SOLUTION: A current limiter layer 27 in which conductive sections and insulating sections mixedly exist is provided on the sense current reaching surface side (upper surface side) of a free magnetic layer 26. Since the effective element area of the CPP magnetic detecting element can be reduced even when the optical element area of the element is increased, the element can be manufactured easily by using a lithographic technique having precision equivalent to that of the conventional lithographic technique and, at the same time, the reproduction output of the element can be increased.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to CPP (current
perpendicular to the plane) type magnetic detection element, in particular, even if the optical element size is large, the effective element size can be made small, and the reproduction output can be effectively and easily improved. And a manufacturing method thereof.

[0002]

2. Description of the Related Art FIG. 23 is a partial cross-sectional view of the structure of a conventional magnetic detecting element as seen from the side facing a recording medium.

Reference numeral 1 shown in FIG. 23 is an underlayer of Ta or the like, on which an antiferromagnetic layer 2 of PtMn or the like is formed. Further, a fixed magnetic layer 3 made of NiFe or the like is formed on the antiferromagnetic layer 2, and a nonmagnetic intermediate layer 4 made of Cu or the like is formed on the fixed magnetic layer 3. A free magnetic layer 5 made of NiFe or the like is formed on the non-magnetic intermediate layer 4. A protective layer 6 made of Ta or the like is formed on the free magnetic layer 5. The multilayer film 9 is composed of the base layer 1 to the protective layer 6.

The magnetization of the pinned magnetic layer 3 is pinned in the Y direction shown by the exchange anisotropic magnetic field with the antiferromagnetic layer 2.

The magnetization of the free magnetic layer 5 is aligned in the X direction shown by the longitudinal bias magnetic fields from the hard bias layers 7 formed on both sides of the free magnetic layer 5 in the track width direction (X direction shown in the drawing). To be

As shown in FIG. 23, electrode layers 8 and 8 are formed on the hard bias layers 7 and 7. The track width Tw is determined by the length of the upper surface of the free magnetic layer 5 in the track width direction (X direction in the drawing).

The direction of flow of the sense current of the magnetic detecting element shown in FIG. 23 is called a CIP (current in the plane) type which flows in a direction substantially parallel to each film surface of the multilayer film 9, and its pattern is shown. The diagram is shown in FIG.

As shown in FIG. 24, the width of the upper surface of the free magnetic layer of the multilayer film composed of the layers from the antiferromagnetic layer to the free magnetic layer is the track width Tw, and the film thickness of the multilayer film is T, the length of the multilayer film in the height direction (Y direction in the drawing) is MRh.

Here, for example, the current density (J = I / (MRh
XT)) and the film thickness T are constant, and the track width Tw and the height length MRh are reduced to 1 / S, the resistance value R of the multilayer film is constant and therefore the resistance change amount ΔR is also constant. Is. Further, the sense current I becomes 1 / S times. Therefore, the output ΔV (= ΔR × I) becomes 1 / S times smaller.

On the other hand, assuming that the heat generation amount P is constant and the track width Tw and the height length MRh are reduced to 1 / S, the resistance value R of the multilayer film is constant and therefore the resistance change amount ΔR is also constant. And the sense current I is also constant, the output ΔV has a constant value.

On the other hand, a CPP (currentperpendicular to) flow of a sense current from a direction perpendicular to each film surface of the multilayer film.
In the case of the plane) type magnetic detection element, the output (ΔV) changes as follows.

FIG. 25 is a schematic view of a CPP type magnetic sensing element. Similar to FIG. 24, the track width determined by the width of the upper surface of the free magnetic layer of the multilayer film of the magnetic detection element is Tw.
The thickness of the multilayer film is T, and the length of the multilayer film in the height direction (Y direction in the drawing) is MRh.

As in the case of the CIP type described above,
The current density (J = I / (Tw × MRh)) and the film thickness T are constant, and the track width Tw and the height length MRh are 1 / S.
If it is reduced by a factor of two, the resistance value R of the multilayer film becomes S2 times, and the resistance change amount ΔR also becomes S2 times. Further, the sense current I becomes 1 / S2 times. Therefore, the output ΔV
(= ΔR × I) is constant.

On the other hand, assuming that the heat generation amount P is constant and the track width Tw and the height length MRh are reduced by 1 / S times, the resistance value R of the multilayer film becomes S2 times, and the resistance change amount ΔR also becomes S2. Doubled. Further, since the sense current I becomes 1 / S times, the output ΔV becomes S times larger.

As the element size becomes narrower in this way,
It is expected that the CPP type can increase the reproduction output ΔV more than the CIP type, and the CPP type can appropriately cope with the narrowing of the element size accompanying the future increase in recording density.

[0016]

However, in the CPP type magnetic sensing element, the track width Tw and the length MRh in the height direction must be 0.1 μm or less (that is, the element area must be 0.01 μm 2 or less). ), CI
It was found that a higher reproduction output could not be obtained effectively than the P type.

It is considered that the element size will gradually decrease with the increase in recording density in the future.
Forming a magnetic detection element having an element area of m square is extremely difficult with the accuracy of the photolithography technology at the present time, and even if the element size is made too small, the leakage magnetic field from the recording medium is effectively made. It is considered that the magnetic field cannot be detected by the magnetic detection element, resulting in a decrease in reproduction output and a decrease in reproduction waveform stability.

Therefore, the present invention is intended to solve the above-mentioned conventional problems. The effective element size can be reduced without reducing the optical element size, and the reproduction output can be improved effectively and easily. An object of the present invention is to provide a magnetic detection element that can be made to operate and a method for manufacturing the same.

[0019]

The present invention provides an antiferromagnetic layer,
In a magnetic sensing element provided with a multilayer film having a pinned magnetic layer, a non-magnetic intermediate layer and a free magnetic layer, and a current flows in a direction perpendicular to the film surface of each layer of the multilayer film, at least the upper surface or the lower surface of the free magnetic layer On the other hand, the present invention is characterized in that a current limiting layer in which an insulating portion and a conductive portion are mixed is provided directly or through another layer.

The present invention is a CPP type magnetic sensing element,
The sense current flows in the direction perpendicular to the film surface of each layer of the multilayer film.

Therefore, the sense current flows vertically in the current limiting layer, but in the present invention, the current limiting layer provided directly on the upper surface or at least one of the free magnetic layers or through another layer is insulated. Since the part and the conductive part are mixed, the sense current flows only in the conductive part.

Therefore, the sense current flowing from the electrode layer into the free magnetic layer through the current limiting layer locally flows in the free magnetic layer only in the portion facing the conductive portion (current density in this portion). Will be locally high).

Therefore, according to the present invention, even if the element area of the free magnetic layer in the direction parallel to the film surface (this element area is called an optical element area) is formed to be as large as the conventional one, the free magnetic layer is actually free. A sense current flows in the magnetic layer, and the element area involved in the magnetoresistive effect (this element area is called the effective element area) can be reduced. Even if the magnetic detection element having a large element size is formed, a CPP type magnetic detection element having a high reproduction output can be easily formed.

Further, since the element size can be made as large as the conventional one, the external magnetic field from the recording medium can be effectively detected by the magnetic detection element, the reproduction output is improved, and the reproduction waveform stability is improved. Can be improved.

Further, in the present invention, it is preferable that a noble metal material layer is formed on one or both of the lower surface and the upper surface of the current limiting layer. In the present invention, the current limiting layer has a vertical cross section (a plane cut in the film thickness direction).
In view of the above, it is necessary that the contrast of the conductivity of the opening (that is, the portion that becomes the current path of the sense current) and the non-opening is high.

FIG. 26 is an example of the above-mentioned poor contrast. As shown in FIG. 26, an insulating film (insulating portion) having irregularities is formed on the entire surface of the GMR film. The formation of such an insulating film is, for example, when the oxidation proceeds more than necessary. Then, a conductive film is formed on the insulating film, and the insulating film and the conductive film form a current limiting layer. However, in the example shown in FIG. 26, since the insulating film is formed on one surface of the GMR film, the current (indicated by the arrow) passing through the current limiting layer is the same as that of the thin insulating film. Although the current can easily flow to the portion, the current path cannot be narrowed down appropriately, and the contact resistance value only increases, so that the apparent ΔR * A (resistance change amount * element area) is not appropriately improved.

On the other hand, FIG. 27 is an example in which the above-mentioned contrast is good, and as shown in FIG. 27, on the GMR film,
A current limiting layer is formed on the base layer made of a noble metal.

The insulating film (insulating portion) forming the current limiting layer is formed on the base layer in a scattered island shape,
A plurality of holes are formed from the lower surface to the upper surface between the insulating films, and these holes serve as openings. A conductive film (conductive portion) fills the inside of this hole. In the example shown in FIG. 27, the contrast between the opening (hole) and the non-opening (insulating portion) is good, and the current flowing through the current limiting layer (indicated by the arrow) is concentrated in the opening. Then, the current path is appropriately narrowed. Therefore, apparent ΔR * A (resistance change amount * element area) can be improved as compared with the example of FIG. 26, and reproduction characteristics such as reproduction output can be appropriately improved.

In order to improve the above-mentioned contrast, it is preferable to lay a noble metal underlayer as shown in FIG. The noble metal underlayer has a small surface energy (γs), and an island-shaped insulating film, for example, can be appropriately grown on the underlayer. Such island-shaped film growth is called Volmer-Weber (VW) type growth.
For details of this VW-type growth, see "Approach to Thin Film Growth Process" Vol. 14, No. 3,1
990 (P527-P531).

Further, by laying the noble metal underlayer, for example, a thin metal film is grown in an island shape on the underlayer,
When this thin film is oxidized, this oxidation does not reach the GMR film formed under the underlayer. When the GMR film is oxidized, the contrast is deteriorated as shown in FIG. 26. However, since the GMR film is not oxidized, the contrast between the opening and the non-opening can be kept good.

By providing a layer (protective layer) made of the noble metal element on the current limiting layer, the current limiting layer is formed on the current limiting layer by a heat treatment performed during a manufacturing process. Oxygen does not diffuse into the layer, and good contrast can still be maintained.

In the present invention, the noble metal material layer is made of Ru,
It is preferable to be formed of one or more precious metal materials selected from Pt, Au, Rh, Ir, Pd, Os, and Re. Or, instead of the noble metal material layer, C
A u layer may be formed.

Further, in the present invention, it is preferable that the current limiting layer is provided at least on the current reaching surface side of the free magnetic layer, either directly or through another layer. As a result, the current path of the sense current can be appropriately narrowed down, and the effective element area can be reduced.
It becomes possible to manufacture the magnetic type magnetic sensing element.

Further, in the present invention, the insulating portion of the current limiting layer is an insulating material film provided with a plurality of holes communicating at least from the upper surface to the lower surface of the current limiting layer, and the conductive portion is provided in the holes. It is preferable that a conductive material film that becomes

Alternatively, in the present invention, the insulating portion of the current limiting layer has a groove that extends continuously when viewed from a plane parallel to the film surface, and the groove extends from the upper surface to the lower surface of the current limiting layer. It is preferable that a conductive material serving as the conductive portion is embedded in the groove.

Alternatively, in the present invention, the insulating portion of the current limiting layer extends continuously from a hole extending from the upper surface to the lower surface of the current limiting layer when seen from a plane parallel to the film surface, It is preferable that it is an insulating material film in which a groove communicating from the upper surface to the lower surface of the limiting layer is mixed, and a conductive material to be the conductive portion is embedded in the hole and the groove.

Further, in the present invention, the insulating material film is preferably formed of an oxide film or a nitride film. At this time, the oxide film is formed of Ag, Cu, Zn, Ge, Pb, A.
l, Ti, Zr, Hf, Cr, Ta, V, Nb, Mo,
It is preferably formed of an insulating material made of an oxide of one or more of W, Fe, Co, Si, Ni, and a rare earth element.

The nitride film is made of Ag, Cu, Zn, G
e, Pb, Al, Ti, Zr, Hf, Cr, Ta, V,
It is preferable to use an insulating material made of a nitride of any one or more of Nb, Mo, W, Fe, Co, Si, Ni, and a rare earth element.

Alternatively, in the present invention, it is preferable that the conductive portion of the current limiting layer is a conductive particle, and the conductive particle is dispersed in an insulating material layer that serves as the insulating portion.

As a specific example, the current limiting layer is
The fine crystal grains mainly composed of Fe and serving as the conductive portion are
i, Zr, Hf, Nb, Ta, Mo, W, and one or more elements M selected from rare earth elements and O or N dispersed in an amorphous material serving as the insulating portion. It is preferable that the film has a different film structure.

In the above case, the current limiting layer is made of Fe.
It has a composition formula of aMbOc, and composition ratios a, b and c are atomic%
40 ≦ a ≦ 50, 10 ≦ b ≦ 30, 20 ≦ c ≦ 40
And it is preferable to satisfy the relationship of a + b + c = 100.

In the present invention, the current limiting layer is Fe.
It has a composition formula of dMeNf and the composition ratios d, e, and f are atomic%.
, 60 ≦ d ≦ 70, 10 ≦ e ≦ 15, 19 ≦ f ≦ 25
And it is preferable to satisfy the relationship of d + e + f = 100.

Further, in the present invention, the insulating material film is a layer in which Co is mainly oxidized, and R is contained in the insulating material film.
u, Pt, Au, Rh, Ir, Pd, Os, Re, C
Conductive particles formed of a metal material of one or more of u and Ag may be dispersed.

Alternatively, in the present invention, the insulating portion of the current limiting layer may be insulating particles, and the insulating particles may be dispersed in a conductive material film to be the conductive portion.

In each of the above current limiting layers, a film structure in which an insulating portion and a conductive portion are appropriately mixed can be used,
It is possible to appropriately reduce the effective element size.

The method for manufacturing a magnetic sensing element according to the present invention is characterized by including the following steps. (A) From the bottom, a first electrode layer, an antiferromagnetic layer, a pinned magnetic layer,
A non-magnetic intermediate layer and a free magnetic layer are laminated in this order, and an insulating material film is sputtered on the upper surface of the free magnetic layer. At this time, the insulating material film is formed on the upper surface of the insulating material film from the upper surface. A step of forming a plurality of holes extending to the lower surface, and (b) forming a conductive material film on the insulating material film by sputtering, and forming the conductive material film inside the holes formed in the insulating material film at this time. And (c) forming a second electrode layer on the current limiting layer composed of the insulating material film and the conductive material film.

By the steps described above, the free magnetic layer is composed of an insulating material film in which a plurality of holes easily communicating, for example, from the lower surface to the upper surface, and a conductive material layer embedded in the holes are easily formed. It is possible to easily form the current limiting layer.

Further, in the present invention, it is preferable that in the step (a), a base layer made of a noble metal element is formed, and then the insulating material film is formed on the base layer. At this time, the underlayer is made of Ru, Pt, Au, Rh, Ir, Pd,
It is preferable to form the noble metal material of at least one of Os and Re.

Alternatively, in the step (a), an underlayer made of Cu may be formed, and then the insulating material film may be formed on the underlayer.

In the present invention, when the insulating material film is formed by sputtering in the step (a), the insulating material film may be formed as a discontinuous film on the free magnetic layer or the underlayer. preferable. This makes it easy to form a plurality of holes in the insulating material film, for example, from the lower surface to the upper surface. In order to make the insulating material film a discontinuous film, material selection and sputtering conditions are important. The sputtering conditions include the substrate temperature, Ar gas pressure, the distance between the substrate and the target, and the like.

Further, as described above, when the underlayer made of the noble metal element is laid, the insulating material film is particularly easy to form as a discontinuous film. The reason is that the surface energy of the underlayer is lower than that of the surface of the GMR film, and the elements tend to aggregate to form nuclei.

In the present invention, the insulating material film is
l, Si, Ti, Zr, Hf, Cr, Ta, V, Nb,
Mo, W, Fe, Ni, Co any one kind or two or more kinds of the insulating material consisting of an oxide is sputter-deposited.
At this time, it is preferable to stop the sputtering in a state in which a plurality of holes communicating from the lower surface to the upper surface or grooves continuously extending when viewed from a plane parallel to the film surface are left in the insulating material film.

In the present invention, when forming the insulating material film in the step (a), first, Ag, Cu, Zn, Ge,
Pb, Al, Ti, Zr, Hf, Cr, Ta, V, N
b, Mo, W, Fe, Co, Si, Ni, or one or more metal elements selected from rare earth elements are formed by sputtering, and a plurality of metal elements that pass from the lower surface to the upper surface are formed in the film made of the metal elements. Stopping sputtering in the state where a hole or a groove extending continuously when viewed from a plane parallel to the film surface is left, then oxidizing the film made of the metal element, and using this oxide film as an insulating material film. Is preferred.

As mentioned above, when an oxidation step is required,
In particular, by laying an underlayer formed of a noble metal element under the current limiting layer, it is possible to appropriately prevent the oxidation from reaching the GMR film formed under the underlayer. It is possible to maintain good contrast between the opening and the non-opening of the current limiting layer.

In the present invention, the insulating material film is
l, Si, Ti, Zr, Hf, Cr, Ta, V, Nb,
Sputter deposition is performed using an insulating material composed of one or more nitrides of Mo, W, Fe, Ni and Co.
At this time, it is preferable to stop the sputtering in a state in which a plurality of holes communicating from the lower surface to the upper surface or grooves continuously extending when viewed from a plane parallel to the film surface are left in the insulating material film.

Alternatively, in the present invention, when forming the insulating material film in the step (a), first, Ag, Cu, Zn and G are formed.
e, Pb, Al, Ti, Zr, Hf, Cr, Ta, V,
Nb, Mo, W, Fe, Co, Si, Ni, and one or more metal elements selected from the rare earth elements are formed by sputtering, and a plurality of metal elements that pass from the lower surface to the upper surface of the film made of the metal elements are formed. Stopping sputtering in a state where a hole or a groove extending continuously when viewed from a plane parallel to the film surface is left, and then nitriding the film made of the metal element, and using this nitride film as an insulating material film. Is preferred.

The method of manufacturing a magnetic sensing element according to the present invention is characterized by including the following steps. (D) A first electrode layer, an antiferromagnetic layer, a pinned magnetic layer, a nonmagnetic intermediate layer, and a free magnetic layer are laminated in this order from the bottom, and FeaMbO is further formed on the upper surface of the free magnetic layer.
c (However, element M is Ti, Zr, Hf, Nb, Ta, M
O, W and one or more elements selected from rare earth elements), and the composition ratios a, b and c are atomic%
40 ≦ a ≦ 50, 10 ≦ b ≦ 30, 20 ≦ c ≦ 40
Where a + b + c = 100 is satisfied, and fine crystal grains containing Fe as a main component are dispersed in an amorphous material containing a compound of elements M and O to form a current limiting layer by sputtering. A step of forming a film, and (e) a second layer on the current limiting layer.
Forming an electrode layer of.

In the present invention, the above-mentioned current limiting layer is heat-treated, and this heat treatment promotes the oxidation of the element that is easily oxidized in the film to adjust the ratio of the openings of the current limiting layer. preferable. The ratio of the openings is preferably about 10% to 30% of the whole.

Alternatively, in the present invention, F in the step (d) is
Instead of eaMbOc, FedMeNf (provided that the element M is T
i, Zr, Hf, Nb, Ta, Mo, W, and one or more elements selected from rare earth elements), and the composition ratios d, e, and f are atomic% and 60 ≦ d ≦ 7
0, 10 ≦ e ≦ 15, 19 ≦ f ≦ 25, and d + e + f =
Even if the current limiting layer is formed by sputtering, the relationship of 100 is satisfied, and fine crystal grains containing Fe as a main component are dispersed in an amorphous material containing a compound of the elements M and N. Good.

In the above manufacturing method, fine crystal grains containing Fe as a main component are formed on the upper surface of the free magnetic layer as Ti, Zr, and H.
Easily forming a current limiting layer dispersed in an amorphous material containing a compound of one or more elements M selected from f, Nb, Ta, Mo, W and rare earth elements and O or N. be able to.

Further, in the present invention, Fea in the step (d) is
Instead of MbOc, the current limiting layer is made of Co, Ru, Pt,
It is formed by sputtering Co by oxidizing a material containing a metal element of one or more of Au, Rh, Ir, Pd, Os, Re, Cu and Ag, and then oxidizing the Co by heat treatment. May be.

In the present invention, in the step (d), it is preferable to form an underlayer made of a noble metal material on the upper surface of the free magnetic layer before forming the current limiting layer.

In particular, when using the manufacturing process in which the current limiting layer is subjected to the heat treatment to advance the ratio of the oxide layer as described above, by providing an underlayer made of a noble metal element under the current limiting layer, GM formed under the underlayer
It is possible to prevent the R film from being oxidized.

The base layer is made of Ru, Pt, Au, R
It is preferable to use any one or more of noble metal materials selected from h, Ir, Pd, Os and Re. Alternatively, in the step (d), it is preferable to form an underlayer made of Cu on the upper surface of the free magnetic layer before forming the current limiting layer.

Further, in the present invention, after forming the current limiting layer, Pt, Au, Rh and I are formed on the upper surface of the current limiting layer.
It is preferable to form a protective layer made of one or more precious metal materials selected from r, Pd, Os, and Re. Alternatively, after forming the current limiting layer, it is preferable to form a protective layer made of Cu on the upper surface of the current limiting layer. In the manufacturing process of the magnetic sensing element, heat treatment may be performed after the current limiting layer is formed. However, by providing the protective layer made of the noble metal element, it is possible to appropriately prevent the diffusion of oxygen into the layer formed on the current limiting layer. In such a case, the protective layer can be the second electrode layer.

In the present invention, from the bottom, the first electrode layer,
A multilayer film may be laminated in the order of the current limiting layer, the free magnetic layer, the non-magnetic intermediate layer, the pinned magnetic layer and the antiferromagnetic layer.

[0067]

FIG. 1 is a partial cross-sectional view of the entire structure of a magnetic detection element (single spin valve type magnetoresistive effect element) according to a first embodiment of the present invention, as viewed from the side facing a recording medium. . In FIG. 1, only the central portion of the element extending in the X direction is cut away.

Shield layers (not shown) are provided above and below the magnetic detection element shown in FIG. 1 via a gap layer (not shown), and the magnetic detection element, the gap layer and the shield layer are combined. Is called an MR head.

The electrode layers 20 and 33 shown in FIG. 1 may also serve as the gap layer, or the electrode layer 2
When 0 and 33 are made of a magnetic material, they may also serve as a shield layer.

The MR head is for reproducing the external signal recorded on the recording medium. Further, in the present invention, an inductive head for recording may be laminated on the MR head. The shield layer (upper shield layer) formed on the upper side of the magnetic detection element may also serve as the lower core layer of the inductive head.

The MR head is made of, for example, alumina-
It is formed on the trailing end surface of a slider made of titanium carbide (Al2O3-TiC). The slider is joined to an elastically deformable support member made of stainless steel or the like on the side opposite to the surface facing the recording medium to form a magnetic head device.

Reference numeral 20 shown in FIG. 1 is a first electrode layer. The first electrode layer 20 is formed of, for example, α-Ta, Au,
It is formed of Cr, Cu (copper), W (tungsten), or the like.

A base layer 21 is formed in the center of the upper surface of the first electrode layer 20. The underlayer 21 is made of Ta, H
It is preferably formed of at least one of f, Nb, Zr, Ti, Mo and W. The base layer 21 is 5
It is formed with a film thickness of about 0 Å or less. The underlayer 21
May not be formed.

Next, a seed layer 22 is formed on the base layer 21. The seed layer 22 is mainly made of face-centered cubic crystal, and the (111) plane is preferentially oriented in a direction parallel to the interface with the antiferromagnetic layer 23 described next. The seed layer 22 is made of a NiFe alloy or a Ni-Fe-Y alloy (where Y is Cr, Rh, Ta,
It is preferably formed of at least one selected from Hf, Nb, Zr, and Ti). The seed layer 22 formed of these materials is the base layer 2 formed of Ta or the like.
By being formed on 1, the (111) plane is likely to be preferentially oriented in the direction parallel to the interface with the antiferromagnetic layer 23. The seed layer 22 is formed, for example, with a thickness of about 30Å.

Since the magnetic sensing element according to the present invention is of the CPP type in which the sense current flows in the direction perpendicular to the film surface of each layer, it is necessary to appropriately flow the sense current also in the seed layer 22. Therefore, it is preferable that the seed layer 22 is not made of a material having a high specific resistance. That is, in the CPP type, the seed layer 22 is preferably formed of a material having a low specific resistance such as a NiFe alloy. The seed layer 22 may not be formed.

Next, an antiferromagnetic layer 23 is formed on the seed layer 22. The antiferromagnetic layer 23 contains the element X
It is preferable that the antiferromagnetic material contains Mn (where X is one or more elements selected from Pt, Pd, Ir, Rh, Ru, and Os) and Mn. Alternatively, the antiferromagnetic layer 23 includes the elements X and X '(wherein the element X'is Ne, Ar, Kr, Xe, Be, B, C,
N, Mg, Al, Si, P, Ti, V, Cr, Fe, C
o, Ni, Cu, Zn, Ga, Ge, Zr, Nb, M
o, Ag, Cd, Sn, Hf, Ta, W, Re, Au,
It is preferably formed of an antiferromagnetic material containing Pb and one or more of rare earth elements) and Mn.

These antiferromagnetic materials are excellent in corrosion resistance and have a high blocking temperature, and the pinned magnetic layer 2 described below is used.
A large exchange anisotropic magnetic field can be generated at the interface with 4. The antiferromagnetic layer 23 is preferably formed with a film thickness of 80 Å or more and 300 Å or less.

Next, a pinned magnetic layer 24 is formed on the antiferromagnetic layer 23. In this embodiment, the pinned magnetic layer 24 has a three-layer structure.

The layers 51 and 53 forming the pinned magnetic layer 24 are magnetic layers, for example, Co, CoFe, N.
It is formed of iFe, CoFeNi, or the like. The magnetic layer 5
An intermediate layer 52 made of Ru or the like is interposed between the magnetic layers 51 and 53. With this configuration, the magnetic layer 51 and the magnetic layer 53 are formed.
The magnetization directions of are made antiparallel to each other. This is called a so-called artificial ferri structure.

The antiferromagnetic layer 23 and the pinned magnetic layer 2
An exchange anisotropic magnetic field is generated between the magnetic layer 51 and the magnetic layer 51 in contact with the antiferromagnetic layer 23, and the magnetization of the magnetic layer 51 is fixed in the height direction (Y direction in the drawing). In this case, the other magnetic layer 53 is magnetized and fixed in the direction opposite to the height direction (the direction opposite to the Y direction in the drawing) by the RKKY interaction. With this configuration, the magnetization of the pinned magnetic layer 24 can be stabilized, and the exchange anisotropic magnetic field generated at the interface between the pinned magnetic layer 24 and the antiferromagnetic layer 23 can be apparently increased.

For example, the magnetic layers 51 and 53 are each formed to have a film thickness of about 10 to 70 Å. Further, the film thickness of the intermediate layer 52 is formed in the range of 3Å to 10Å.

The magnetic layers 51 and 53 are made of different materials and have different thicknesses so that the magnetic moments per unit area are different. The magnetic moment is set by saturation magnetization Ms × film thickness t,
For example, when both the magnetic layers 51 and 53 are made of the same material and the same composition, the magnetic moments of the magnetic layers 51 and 53 can be made different by making the film thicknesses of the magnetic layers 51 and 53 different. it can. This allows the magnetic layers 51 and 53 to have an artificial ferri structure appropriately.

In the present invention, the pinned magnetic layer 24 may be formed of a single layer film or a laminated film of NiFe alloy, NiFeCo alloy, CoFe alloy or the like instead of the ferri structure.

A non-magnetic intermediate layer 25 is formed on the fixed magnetic layer 24. The nonmagnetic intermediate layer 25 is formed of a conductive material having a low electric resistance, such as Cu. The nonmagnetic intermediate layer 25 is formed to have a film thickness of, for example, about 25Å.

Next, a free magnetic layer 26 is formed on the nonmagnetic intermediate layer 25. It is preferable that the free magnetic layer 26 has a two-layer structure and a Co film 54 is formed on the side facing the non-magnetic intermediate layer 25. This can prevent the diffusion of metal elements and the like at the interface with the non-magnetic intermediate layer 25 and increase the resistance change rate (ΔGMR). Further, on the Co film 54, a NiFe alloy,
It is preferable to form the magnetic layer 55 formed of a CoFe alloy, Co, a CoNiFe alloy, or the like. The total thickness of the free magnetic layer 26 is 10 Å or more.
It is preferably formed with a film thickness of approximately 0 Å or less.

The free magnetic layer 26 may be formed of a single layer structure using any of the above magnetic materials.

A current limiting layer 27 is formed on the free magnetic layer 26. The film structure of the current limiting layer 27 will be described later in detail.

In the present invention, the track width direction of the multilayer film 28 from the underlayer 21 to the current limiting layer 27 (X in the drawing).
Both end surfaces 28a, 28a in the direction) are continuous inclined surfaces, and the multilayer film 28 has a substantially trapezoidal shape.

As shown in FIG. 1, insulating layers 29 are formed on both sides of the multilayer film 28 in the track width direction. The insulating layer 29 is formed of a general insulating material such as Al ₂ O ₃ and SiO ₂ .

The upper surface 29a of the insulating layer 29 is preferably formed below the lower surface of the free magnetic layer 26 in the figure (the direction opposite to the Z direction in the figure).

A bias underlayer 30 is formed on the insulating layer 29. A hard bias layer 31 is formed on the bias base layer 30. The hard bias layers 31 are formed at positions facing both sides of the free magnetic layer 26. The hard bias layer 31
Is magnetized in the track width direction (X direction in the drawing),
The longitudinal bias magnetic field from the hard bias layer 31 aligns the magnetization of the free magnetic layer 26 in the X direction in the drawing.

The bias underlayer 30 is provided to improve the characteristics (coercive force Hc, squareness S) of the hard bias layer 31.

In the present invention, the bias underlayer 30 is
The crystal structure is preferably formed of a metal film having a body-centered cubic structure (bcc structure). At this time, the crystal orientation of the bias underlayer 30 is preferably such that the (100) plane is preferentially oriented.

The hard bias layer 31 is made of CoP.
It is formed of a t alloy, a CoPtCr alloy, or the like. The crystal structure of these alloys is a dense hexagonal structure (hcp) single phase or a mixed phase of a face-centered cubic structure (fcc) and a dense hexagonal structure (hcp).

Here, CoPt forming the bias underlayer 30 and the hard bias layer 31 formed of the above metal film.
Since the lattice constants of the hcp structure of system alloys are close to each other,
The CoPt-based alloy is difficult to form the fcc structure and is likely to be formed in the hcp structure. At this time, the c-axis of the hcp structure is C
It is preferentially oriented within the boundary surface between the oPt-based alloy and the bias underlayer. Since the hcp structure has a larger magnetic anisotropy in the c-axis direction than the fcc structure, the hard bias layer 31
The coercive force Hc when a magnetic field is applied to is increased. Furthermore, since the c-axis of hcp is preferentially oriented in the boundary surface between the CoPt-based alloy and the bias underlayer, the remanent magnetization increases, and the squareness ratio S determined by the remanent magnetization / saturation magnetic flux density increases. As a result, the hard bias layer 3
1 can be improved and the bias magnetic field generated from the hard bias layer 31 can be increased.

In the present invention, the crystal structure is the body-centered cubic structure (b
(cc structure) metal film is Cr, W, Mo, V, Mn, N
It is preferably formed of one or more of b and Ta.

Further, in the present invention, it is preferable that the bias underlayer 30 is formed only under the hard bias layer 31, but it is also slightly interposed between the both end surfaces 28a of the multilayer film 28 and the hard bias layer 31. You may. The bias underlayer 30 formed on both end surfaces 28a of the multilayer film 28 has a film thickness of 1 in the track width direction (X direction in the drawing).
It is preferably nm or less.

As a result, since the hard bias layer 31 and the free magnetic layer 26 can be magnetically formed into a continuous body, problems such as a buckling phenomenon in which an end portion of the free magnetic layer 26 is affected by a demagnetizing field also occur. Without the free magnetic layer 2
The magnetic domain control of 6 can be easily performed.

Further, as shown in FIG. 1, an insulating layer 32 is formed on the hard bias layer 31. The insulating layer 32 is formed of a general insulating material such as Al2O3 or SiO2.

In this embodiment, the upper surface of the insulating layer 32 and the upper surface of the current limiting layer 27 are flush with each other, but the upper surface of the insulating layer 32 and the current limiting layer 27 are flat.
Does not need to be flush with the top surface of.

The current limiting layer 2 is formed on the insulating layer 32.
The second electrode layer 33 is formed on the upper surface of the electrode 7. The second
Like the first electrode layer 20, the electrode layer 33 is formed of, for example, α-Ta, Au, Cr, Cu (copper), W (tungsten), or the like.

In this embodiment, the second electrode layer 33 is used.
From which a sense current flows toward the first electrode layer 20,
The sense current may flow from the first electrode layer 20 toward the second electrode layer 33. Therefore, the sense current flows in each layer in the multilayer film 28 in a direction perpendicular to the film surface, and such a flow direction of the sense current is called CPP type.

In this magnetic detecting element, the fixed magnetic layer 24,
When a detection current (sense current) is applied to the non-magnetic intermediate layer 25 and the free magnetic layer 26, the recording medium such as a hard disk runs in the Z direction, and a leakage magnetic field from the recording medium is applied in the Y direction. The magnetization of the magnetic layer 26 changes from one direction in the X direction in the figure toward the Y direction. Fluctuations in the direction of magnetization in the free magnetic layer 26 and the fixed magnetic layer 2
The electric resistance changes in relation to the fixed magnetization direction of No. 4 (this is called the magnetoresistive effect), and the leakage magnetic field from the recording medium is detected by the voltage change based on the change of the electric resistance value.

By the way, in the present invention, as shown in FIG. 1, the current limiting layer 27 is formed between the free magnetic layer 26 and the second electrode layer 33.

The current limiting layer 27 in the present invention has a film structure shown in FIG. 9, for example. FIG. 9 is a partial schematic diagram of the antiferromagnetic layer 23, the pinned magnetic layer 24, the nonmagnetic intermediate layer 25, the free magnetic layer 26, and the current limiting layer 27.

As shown in FIG. 9, the current limiting layer 27 is
An insulating material film (insulating portion) 57 having a plurality of holes 56 formed therein serves as a base material. At least part of the holes 56 penetrates the insulating material film 57 from the lower surface to the upper surface.

As shown in FIG. 9, a conductive material film (conductive portion) 58 is formed on the insulating material film 57. The conductive material film 58 is also formed in the hole 56 formed in the insulating material film 57, and the hole 56 is filled with the conductive material film 58. Note that in FIG. 9, in order to simplify the description on the drawing, the words "hole 56" and "conductive material film 58" are written only in some holes.

Here, the insulating material film 57 is preferably formed of an oxide film or a nitride film. The oxide film is made of Ag, Cu, Zn, Ge, Pd, Al, Ti, Z.
r, Hf, Cr, Ta, V, Nb, Mo, W, Fe, C
It is preferable to use an insulating material composed of an oxide of one or more of any one of o, Si, Ni, and a rare earth element. The nitride film is made of Ag, Cu, Zn, Ge, P.
d, Al, Ti, Zr, Hf, Cr, Ta, V, Nb,
It is preferably formed of an insulating material made of a nitride of any one or more of Mo, W, Fe, Co, Si, Ni, and a rare earth element.

When these oxide film and nitride film are thinly formed on the free magnetic layer 26, they are easily aggregated into a discontinuous film during sputtering film formation. When the discontinuous film is formed, holes 56 that penetrate from the upper surface to the lower surface as shown in FIG. 9 are easily formed in the insulating material film 57.

Whether or not the discontinuous film is formed is not only the selection of the material but also the sputtering condition is an important factor. The sputtering condition for forming the insulating material film 57 as a discontinuous film is to lower the substrate temperature to about 20 ° C. to 200 ° C.,
Ar gas pressure is 10 to 50 mTorr (1.3 to 6.7 P
For example, the height may be increased to about a) or the distance between the substrate and the target may be set to about 200 to 300 mm.

In the sputter film formation described above, for example,
Any of the RF sputtering method, the RF magnetron sputtering method, the DC magnetron sputtering method, the ion beam sputtering method, the long throw sputtering method, the collimation sputtering method, or a combination thereof can be used.

For the conductive material film 58, a general conductive material can be used. For example, similar to the electrode layers 20 and 33, α-Ta, Au, Cr, Cu (copper) and W (tungsten) are used. ) Or the like, but the conductive material film 58 is formed of Ru, Pt, Au, Rh, Ir, Pd, O.
It is preferable to be formed from one or more precious metal elements selected from s and Re. Note that Cu may be added.

The noble metal element itself is a material that is difficult to oxidize, and the conductive material film 58 made of the noble metal element is formed on the insulating material film 57 and in the holes 56 to diffuse oxygen by heat treatment or the like. Can be suppressed, and the contrast between the opening (hole) and the non-opening (insulating material layer) shown in FIG. 9 can be kept good.

As described above, in the present invention, the free magnetic layer 26
By providing the current limiting layer 27 in which the insulating portion and the conductive portion are mixed, the following effects can be expected.

That is, in the CPP type magnetic sensing element as in the present invention, the sense current flowing from the second electrode layer 33 flows in the current limiting layer 27 in the direction perpendicular to the film surface. Since the current limiting layer 27 has a structure in which the conductive material film (conductive portion) 58 is embedded in the hole 56 formed in the insulating material film (insulating portion) 57, the sense current is generated only in the conductive material film 58. Will flow to.

Therefore, the sense current flowing from the second electrode layer 33 into the free magnetic layer 26 through the current limiting layer 27 passes through the free magnetic layer 26 and the conductive material film 58.
Flows locally only in the portion facing (the current density in this portion is locally increased).

Therefore, according to the present invention, even if the element area of the free magnetic layer 26 in the direction parallel to the film surface (this element area is referred to as an optical element area) is formed to be as large as the conventional one, it is actually A sense current flows in the free magnetic layer 26, and the element area involved in the magnetoresistive effect (this element area is referred to as an effective element area) can be reduced. Even if the magnetic detection element having a large optical element size is formed, a CPP type magnetic detection element having a high reproduction output can be easily formed.

According to the present invention, as described above, the magnetic sensing element can be formed with the same element area as the conventional one, and specifically, the track width Tw shown in FIG. 9 can be formed to 0.15 to 0.3 μm. Further, the length MRh in the height direction is set to 0.15 to 0.3.
The optical element area is 0.02 to 0.02 μm.
It can be formed as large as 0.09 μm 2.

Further, in the present invention, the effective element area is preferably 0.01 μm 2 or less. The effective element area can be obtained, for example, by multiplying the optical element area (Tw × MRh) by the aperture ratio of the hole 56. This can be roughly obtained from the difference between the resistance value of the GMR film alone and the resistance value of the entire element including the electrodes.

When the current limiting layer 27 is viewed from a plane parallel to the film surface, the ratio of the openings (holes 56) is 10.
% To about 30% is preferable.

Further, in the present invention, since the optical element area is about the same as the conventional one, the external magnetic field from the recording medium can be effectively detected by the magnetic detecting element, and the reproducing characteristic with good sensitivity is excellent. A CPP type magnetic sensing element can be manufactured.

In the present invention, the film structure of the current limiting layer 27 is not limited to that shown in FIG. 9, and another film structure shown in FIG. 10 can be presented.

In the insulating material film 57 of the current limiting layer 27 shown in FIG. 10, a groove 68 that continuously extends is formed when the current limiting layer is viewed in a direction parallel to the film surface. Is formed from the upper surface to the lower surface of the current limiting layer 27. The planar shape of the groove 68 is an elongated curve or is branched in the middle, but may have any shape. A conductive material film 58 is formed in the groove 68 and on the insulating material layer 57. This Figure 9
The difference in the shape of the insulating material film 57 between FIG. The thin film (the insulating material film 57 or the layer on which the insulating material film 57 is based) is the free magnetic layer 2
First, grow up like an island on 6 and grow further,
When these islands start to stick to each other, a groove 68 extending continuously as shown in FIG. 10 is formed.

That is, the planar shape of the current limiting layer 27 changes depending on at which stage the growth of the thin film is stopped. What is important here is the hole 56 penetrating from the lower surface to the upper surface of the insulating material film 57 that constitutes the current limiting layer 27.
Alternatively, the groove 68 is appropriately formed. When the hole 56 or the groove 68 is formed so as to penetrate therethrough, the conductive material film 58 embedded in the hole 56 or the groove 68 serves as a path for flowing a current to the free magnetic layer 26, and an appropriate current path is provided. Can be narrowed down. This is as already described in FIGS. 26 and 27,
In the present invention, the insulating material film does not completely cover the free magnetic layer as shown in FIG. 27, but holes and grooves are formed in some places, and the conductive material layer is embedded in the holes and grooves. ing.

FIG. 27 shows an example in which a base layer made of a noble metal element is provided under the current limiting layer 27, and this embodiment will be described later in detail with reference to the drawings.

As shown in FIG. 10, the current limiting layer 27 is
In the insulating material film 57, a hole 56 communicating from the upper surface to the lower surface of the current limiting layer 27 and continuously extending when viewed from a plane parallel to the film surface are provided from the upper surface to the lower surface of the current limiting layer 27. The groove 68 leading up to may be mixed.

Next, the current limiting layer 27 shown in FIG. 9 is composed of an insulating material film 57 having a plurality of holes 56 formed therein and a conductive material film 58 filling the holes 56. Alternatively, the current limiting layer 27 having the following film structure may be used.

In the present invention, for example, a target made of an insulating material and a target made of a conductive material are prepared, and these two targets are sputtered at the same time so that particles of the insulating material and the conductive material are formed on the free magnetic layer 26. The current limiting layer 27 in which particles are mixed can be formed.

Specifically, it is possible to provide a film structure in which the conductive part of the current limiting layer 27 is a conductive particle, and the conductive particle is dispersed in an insulating material film to be an insulating part.

As an example of the current limiting layer 27 having the above-mentioned film structure, in the current limiting layer 27, fine crystal grains which are a conductive portion containing Fe as a main component are Ti, Zr, Hf, Nb and T.
1 or 2 selected from a, Mo, W and rare earth elements
It has a film structure in which it is dispersed in an amorphous material that serves as an insulating portion containing a compound of at least one element M and O or N.

The current limiting layer 27 has a composition formula of FeaMbOc, and the composition ratios a, b, and c are atomic%, and 40 ≦ a.
≦ 50, 10 ≦ b ≦ 30, 20 ≦ c ≦ 40, and a +
It is preferable to satisfy the relationship of b + c = 100.

Alternatively, in the current limiting layer 27, Fed
Has a composition formula of MeNf, and the composition ratios d, e, and f are atomic%,
It is preferable that 60 ≦ d ≦ 70, 10 ≦ e ≦ 15, 19 ≦ f ≦ 25, and the relationship of d + e + f = 100 is satisfied.

The formation of the current limiting layer 27 is performed by, for example, F
Two targets, an e target and a HfO2 target, are prepared, and these two targets are sputtered. As a result, the current limiting layer 27 in which a large number of fine crystal grains containing bccFe as a main component are deposited inside the amorphous phase matrix
Can be formed.

In the sputter film formation described above, for example,
Any of the RF sputtering method, the RF magnetron sputtering method, the DC magnetron sputtering method, the ion beam sputtering method, the long throw sputtering method, the collimation sputtering method, or a combination thereof can be used.

Alternatively, in the present invention, the current limiting layer 27
The insulating material film forming the is a layer in which Co is mainly oxidized, and Ru, Pt, Au, Rh,
Any one of Ir, Pd, Os, Re, Cu, Ag
It is possible to form the current limiting layer 27 in which the conductive particles formed of one kind or two or more kinds of noble metal materials are dispersed.

Alternatively, the insulating portion of the current limiting layer 27 may be insulating particles, and the insulating particles may have a film structure in which they are dispersed in a conductive material film to be a conductive portion.

A general conductive material such as Cu can be used for the above-mentioned conductive particles, and Al 2 can be used for the insulating particles.
Common insulating materials such as O3 can also be used.

When the current limiting layer 27 is formed of a so-called granular film in which conductive particles are mixed as described above, the current limiting layer 27 is formed according to the particle size of the conductive particles.
If the film thickness is not thin, the conductive particles do not properly function as a current path for the sense current, and the reproduction characteristics such as reproduction output are deteriorated.

Next, the film thickness of the magnetic sensing element of the present invention will be described below.

In the present invention, the fixed magnetic layer 24 (however, in the case of FIG. 1, the magnetic layer 5 that substantially contributes to the magnetoresistive effect) is used.
3), the total film thickness T2 (see FIG. 1) of the nonmagnetic intermediate layer 25 and the free magnetic layer 26 is preferably 60 Å or more and 300 Å or less. For example, the pinned magnetic layer 24 has a thickness of about 20Å, the non-magnetic intermediate layer 25 has a thickness of about 20Å, and the free magnetic layer 26 has a thickness of about 30Å.

From the fixed magnetic layer 24 to the free magnetic layer 26
If the total film thickness T2 up to 60 Å or more and 300 Å or less, the total film thickness T2 is about the same as or slightly smaller than the mean free path of conduction electrons.
Therefore, the conduction electrons can freely pass through the free magnetic layer 26 without being scattered.
It is possible to improve the resistance change rate (ΔMR) of the magnetic detection element. When the total film thickness T2 is 60 Å or less, the reproduction output is lowered, which is not preferable.

In the magnetic sensing element shown in FIG. 1, the sense current flows from the second electrode layer 33 toward the first electrode layer 20 (or vice versa), and the current limiting layer 27 is the free magnetic layer 26. The side on which the sense current reaches (in FIG. 1, the sense current changes from the second electrode layer 33 to the first electrode layer 2).
When flowing toward 0, the upper surface of the free magnetic layer 26 is formed on the arrival surface side of the conduction electrons of the sense current, and the lower surface is formed on the passage surface side of the conduction electrons of the sense current. As a result, the sense current can be effectively narrowed down in the current limiting layer 27, and the effective element area can be reduced, so that a CPP type magnetic detection element having a high reproduction output can be manufactured.

Next, the features of the film structure of the magnetic sensing element shown in FIG. 1 will be described below. In the magnetic sensing element shown in FIG. 1, the free magnetic layer 26 has a track width direction (X in the drawing).
The hard bias layer 31 is provided on both sides of the (direction), and the upper and lower sides thereof are surrounded by the insulating layers 29 and 32.

Therefore, the sense current flowing between the first electrode layer 20 and the second electrode layer 33 becomes difficult to be shunted to both side regions of the multilayer film 28 from the base layer 21 to the current limiting layer 27, Therefore, the sense current can properly flow in the multilayer film 28 and a high reproduction output can be obtained.

When the total film thickness T2 is smaller than the mean free path of the conduction electrons, the conduction electrons directly flow in the vertical direction without reaching the other direction and reach the other electrode layer. In this case, one of the insulating layers 29 and 32 may be omitted.

The film structure other than the magnetic detecting element shown in FIG. 1 will be described below. FIG. 2 is a partial cross-sectional view of the structure of the magnetic sensing element according to the second embodiment of the present invention as seen from the side facing the recording medium. The layers given the same reference numerals as in FIG. 1 are shown as the same layers as in FIG.

In the embodiment shown in FIG. 2, the current limiting layer 27, the free magnetic layer 26, the nonmagnetic intermediate layer 25, the pinned magnetic layer 24, and the antiferromagnetic layer are formed on the central upper surface of the first electrode layer 20 from the bottom. A multilayer film 34 is formed by stacking 23 layers in this order.

The track width direction of the multilayer film 34 (X in the drawing)
Both end surfaces 34a, 34a in the direction) are continuous inclined surfaces and have a substantially trapezoidal shape.

Insulating layer 35, bias base layer 30, and hard bias layer 3 are formed on both sides of the multilayer film 34 from the bottom.
1 and the insulating layer 36 are laminated in this order.

A second electrode layer 33 is formed on the insulating layer 36 and the antiferromagnetic layer 23.

The stacking order of the multilayer film 34 of the embodiment shown in FIG. 2 is opposite to the stacking order of the multilayer film 28 of the embodiment shown in FIG.

Also in this embodiment, the current limiting layer 2
7 is a structure in which an insulating portion and a conductive portion are mixed.

That is, the insulating portion of the current limiting layer 27 is an insulating material film 57 provided with a plurality of holes 56 that communicate at least from the upper surface to the lower surface of the current limiting layer 27. Material conductive film 58
Are embedded film configurations (see FIG. 9). Alternatively, the insulating portion of the current limiting layer 27 has a groove 68 that continuously extends when viewed from a plane parallel to the film surface, and the groove 68 is formed from the lower surface to the upper surface of the current limiting layer. The groove 68 is filled with the conductive material film 58 serving as the conductive portion (see FIG. 10).

Alternatively, the conductive portion of the current limiting layer 27 is a conductive particle, and the conductive particle has a film structure in which it is dispersed in an insulating material layer serving as the insulating portion.

Alternatively, the insulating portion of the current limiting layer 27 is an insulating particle, and the insulating particle has a film structure in which a conductive material film serving as the conductive portion is dispersed.

Also in this embodiment, the insulating layers 35 and 3 are formed above and below the hard bias layer 31 formed on both sides of the multilayer film 34 in the track width direction (X direction in the drawing).
6 is formed to prevent the sense current flowing between the first electrode layer 20 and the second electrode layer 33 from being shunted to the both side regions, so that the sense current mainly flows in the multilayer film 34. Therefore, it is possible to improve the reproduction output.

In the embodiment shown in FIG. 2, the sense current flows from the first electrode layer 20 to the second electrode layer 33 (or vice versa), so that the current limiting layer 27 is free. It is provided directly on the side of the magnetic layer 26 where the sense current reaches.

Next, FIG. 3 is a partial cross-sectional view of the structure of the magnetic sensing element of the third embodiment of the present invention as seen from the side facing the recording medium. Note that the layers denoted by the same reference numerals as in FIG. 1 indicate the same layers as in FIG. In addition, the sense current flows from the second electrode layer 33 toward the first electrode layer 20 (or vice versa).

In this embodiment, the first electrode layer 20
The film structure of the multilayer film 28 formed between the second electrode layer 33 and the second electrode layer 33 is the same as in FIG.

In this embodiment, the first electrode layer 20
Track width direction of the multilayer film 28 from above (X direction in the drawing)
Specular films (also referred to as specular reflection layers) 37, 37 are formed on both end faces 28a, 28a.

The specular film 37 is made of Fe--O, N.
iO, CoO, CoFeO, CoFeNiO, Al-
O, Al-Q-O (where Q is B, Si, N, Ti,
One or more selected from V, Cr, Mn, Fe, Co and Ni), RO (where R is Cu, Ti, V, Cr, Z)
oxides such as r, Nb, Mo, Hf, Ta and W), Al-N, Al-Q-N (where Q is B, Si, O, Ti, V, Cr, Mn, Fe, Co, N
i, one or more selected from i), RN (where R is C
u, Ti, V, Cr, Zr, Nb, Mo, Hf, Ta,
Nitride such as one or more selected from W), NiMnS
b, PtMnSb or other semi-metal whistler metal or the like.

An insulating layer 2 is formed on the specular film 37.
9, a bias base layer 30, a hard bias layer 31, and an insulating layer 32 are laminated. The second electrode layer 33 extends from the insulating layer 32 to the current limiting layer 27.
Are formed.

In this embodiment, since the specular films 37 are formed on both end faces 28a of the multilayer film 28,
Even if the optical element area (Tw × MRh) of the multilayer film 28 becomes small, the conduction electrons can be specularly reflected by the specular film 37, and the conduction electrons can be prevented from being scattered at the both end surfaces 28a. be able to. Therefore, the mean free path (spin diffusion length) of the conduction electrons can be extended, and the rate of resistance change can be further improved.

FIG. 4 is a partial cross-sectional view of the structure of the magnetic sensing element of the fourth embodiment of the present invention as seen from the side facing the recording medium. Note that the layers denoted by the same reference numerals as in FIG. 1 indicate the same layers as in FIG. The sense current is the second
Flowing from the electrode layer 33 toward the first electrode layer 20 (or vice versa).

In the embodiment shown in FIG. 4, a hard bias layer 39 is formed on the free magnetic layer 26 with an intermediate layer 38 interposed therebetween.
Is provided. The current limiting layer 27 is provided on the hard bias layer 39.

In this embodiment, the free magnetic layer 26 is used.
Hard bias layer 3 formed on the intermediate layer 38
A longitudinal bias magnetic field is supplied to the free magnetic layer 26 from both side ends of 9 (indicated by an arrow), so that the magnetization of the free magnetic layer 26 is directed in the X direction in the drawing.

The intermediate layer 38 is preferably made of a non-magnetic conductive material. Specifically, Ru, Rh, I
It is preferably formed of an alloy of one or more of r, Cr, Re and Cu. Also, the intermediate layer 3
8 can also serve as the current limiting layer in the present invention.
The embodiment is FIG.

In the embodiment shown in FIG. 5, a current limiting layer 27 is formed on the free magnetic layer 26. The film structure and material of the current limiting layer 27 are the same as those described in FIG. 1, so please refer to that.

A hard bias layer 39 is formed on the current limiting layer 27. In this embodiment, since it is not necessary to separately form the intermediate layer 38 and the current limiting layer 27 as shown in FIG. 4, the manufacturing process can be facilitated.

However, in FIG. 5, the current limiting layer 27 may be provided between the hard bias layer 39 and the second electrode layer 33.

Further, in FIG. 4, the intermediate layer 38 may be formed of an insulating material such as Al 2 O 3 or SiO 2, but in such a case, the intermediate layer 38 is formed thin and
It is necessary to prevent the sense current flowing between the first electrode layer 20 and the second electrode layer 33 from being blocked by the intermediate layer 38. The thickness of the intermediate layer 38 is 20
It is preferably formed by -100 Å.

Further, unlike the present embodiment, the current limiting layer 27 is provided not directly on the surface (top surface side) where the sense current reaches the free magnetic layer 26, but it is provided via another layer. May be.

The current limiting layer 27 may be formed between the free magnetic layer 26 and the intermediate layer 38 and directly formed on the surface of the free magnetic layer 26 where the sense current reaches.

When the free magnetic layer 26 is formed below the antiferromagnetic layer 23 as in the embodiment shown in FIG. 2, the current limiting layer is formed on the first electrode layer 20. Two
7, the hard bias layer 39, the intermediate layer 38, and the free magnetic layer 26 are stacked in this order.

Alternatively, the hard bias layer 39, the current limiting layer 27, and the free magnetic layer 26 are formed in this order on the first electrode layer 20. In such a case, the sense current is the first
Flowing from the electrode layer 20 toward the second electrode layer 33, and the lower surface side of the free magnetic layer 26 becomes the arrival surface side of the conduction electrons of the sense current. The conduction electrons of the sense current are
It may flow from the electrode layer 33 toward the first electrode layer 20.

As shown in FIG. 4, the free magnetic layer 26 is provided with the hard bias layer 39 via the intermediate layer 38. Alternatively, as shown in FIG. 5, the free magnetic layer 26 is provided via the current limiting layer 27. With the structure in which the hard bias layer 39 is provided, as compared with the case where the hard bias layers are provided on both sides of the free magnetic layer 26, the free magnetic layer 26 is not strongly magnetized and the magnetic domain of the free magnetic layer 26 is not. It is possible to optimize the control and improve the variation in magnetization of the free magnetic layer 26 with respect to the external magnetic field.

In the embodiment shown in FIGS. 4 and 5, the multilayer film 41 extending from the underlayer 21 to the current limiting layer 27 (hard bias layer 39 in FIG. 5) in the track width direction (X direction in the drawing). Only the insulating layer 40 is formed on both side regions.

Therefore, in the embodiment shown in FIGS. 4 and 5, the sense current flowing between the first electrode layer 20 and the second electrode layer 33 effectively flows only in the multilayer film 41, and the sense current It is possible to reduce the diversion loss.

FIG. 6 is a partial cross-sectional view of the structure of the magnetic sensing element of the sixth embodiment of the present invention as seen from the side facing the recording medium.

In the embodiment shown in FIG. 6, the free magnetic layer 26 has a three-layer artificial ferri structure.

Reference numeral 65 that constitutes the free magnetic layer 26.
The layers 67 and 67 are magnetic layers, such as Co, CoFe,
It is formed of NiFe, CoFeNi, or the like. An intermediate layer 66 made of Ru or the like is interposed between the magnetic layers 65 and 67. With this structure, the magnetic layer 65 and the magnetic layer 6 are formed.
The magnetization directions of 7 are made antiparallel to each other by RKKY interaction. This is called a so-called artificial ferri state.

The thickness of each of the magnetic layers 65 and 67 is 1
It is formed in the range of 0 to 70Å. The thickness of the intermediate layer 66 is about 3Å to 10Å.

The magnetic layers 65 and 67 are made of different materials and have different thicknesses so that the magnetic moments per unit area are different. The magnetic moment is set by saturation magnetization Ms × film thickness t,
For example, when both the magnetic layers 65 and 67 are formed of the same material and the same composition, the magnetic moments of the magnetic layers 65 and 67 can be made different by making the thicknesses of the magnetic layers 65 and 67 different. it can. This allows the magnetic layers 65 and 67 to have an artificial ferri structure appropriately.

By forming the free magnetic layer 26 into an artificial ferri structure as shown in FIG. 6, the free magnetic layer 26 can be appropriately formed into a single magnetic domain, a Barkhausen noise is small, and a magnetic detection element having a high reproduction output is manufactured. It is possible to
Of the magnetic layers 65 and 67 of the free magnetic layer 26,
The layer involved in the magnetoresistive effect is the magnetic layer 65 in contact with the nonmagnetic intermediate layer 25.

As shown in FIG. 6, insulating layers 29 are formed on both sides of the multilayer film 42 from the base layer 21 to the current limiting layer 27 in the track width direction (X direction in the drawing). The upper surface of the layer 29 may be formed to the same level as the upper surface of the intermediate layer 66 of the free magnetic layer 26.
That is, the hard bias layer 31 formed on the insulating layer 29 via the bias underlayer 30 may be bonded only to both sides of one magnetic layer 67 forming the free magnetic layer 26.

When the magnetic layer 67, which has been subjected to the longitudinal bias magnetic field from the hard bias layer 31, is magnetized in the X direction in the drawing, the magnetic layer 65 causes the magnetic layer 67 to undergo the RKKY interaction between the magnetic layers 67. It is magnetized antiparallel to the magnetization direction of 67.

The free magnetic layer 26 of the three-layer ferri structure shown in FIG. 6 is applicable to each of the embodiments shown in FIGS.

Further, as shown in FIG. 3, the structure in which the specular films 37 are formed on both sides of the multilayer film, and as shown in FIG. 4, the free magnetic layer 26 has an intermediate surface on the side opposite to the surface in contact with the nonmagnetic intermediate layer 25. The structure in which the hard bias layer 39 is formed via the layer 38, and the current limiting layer 27 on the surface of the free magnetic layer 26 opposite to the surface in contact with the nonmagnetic intermediate layer 25 as shown in FIG.
Any of the structures in which the hard bias layer 39 is formed via the above is applicable to the embodiment of FIG.

FIG. 7 is a partial cross-sectional view of the structure of the magnetic sensing element of the seventh embodiment of the present invention as seen from the side facing the recording medium.

The magnetic sensing element shown in FIG. 7 is a so-called dual type spin valve thin film element. The layers denoted by the same reference numerals as in FIG. 1 indicate the same layers as in FIG.

On the central upper surface of the first electrode layer 20, from the bottom, the underlayer 21, the seed layer 22, the antiferromagnetic layer 23, the fixed magnetic layer 24 of the three-layer ferri structure, the nonmagnetic intermediate layer 25, and the free magnetic layer. 26 is formed. The laminated structure up to this point is the same as in FIG.

Further, in this embodiment, a Co film 54 is formed on the upper surface of the free magnetic layer 26, and a nonmagnetic intermediate layer 59, magnetic layers 60 and 62 and an intermediate layer such as Ru formed between them are formed on the Co film 54. A pinned magnetic layer 63 having a three-layer ferri structure 61, an antiferromagnetic layer 64, and a current limiting layer 27 are sequentially stacked.

In the case of the dual spin-valve type thin film element having the structure shown in FIG. 7, of the pinned magnetic layer 24 formed below the free magnetic layer 26, the magnetic layer 53 involved in the magnetoresistive effect is, for example, in the height direction. When fixed in the Y direction in the drawing, the magnetic layer 60, which is involved in the magnetoresistive effect, of the fixed magnetic layer 63 formed above the free magnetic layer 26 is also fixed in the height direction (Y direction in the drawing). To be done.

In this embodiment, the free magnetic layer 26 may have the three-layer ferri structure shown in FIG. 6, and in such a case, the fixed magnetic layer 26 below the free magnetic layer 26 contributes to the magnetoresistive effect. When the magnetic layer 53 of the magnetic layer 24 is magnetized in the Y direction in the drawing, the magnetic layer 6 of the pinned magnetic layer 63 that contributes to the magnetoresistive effect above the free magnetic layer 26.
0 is magnetized in the direction opposite to the Y direction in the drawing.

As shown in FIG. 7, an insulating layer 29, a bias underlayer 30, and a hard bias layer are provided on both sides of the multilayer film 43 from the underlayer 21 to the current limiting layer 27 in the track width direction (X direction in the drawing). The layer 31 and the insulating layer 32 are sequentially stacked.

Also in this embodiment, a mode using the specular film 37 as shown in FIG. 3 can be used.

Further, in this embodiment, the sense current is the second
Flowing from the electrode layer 33 toward the first electrode layer 20 (or vice versa), and the upper surface side of the free magnetic layer 26 is the arrival surface side of the sense current. The current limiting layer 27 is formed on the upper surface of the antiferromagnetic layer 64 formed above the free magnetic layer 26. The current limiting layer 27 is formed between the free magnetic layer 26 and the nonmagnetic intermediate layer 59. And the current limiting layer 27 is formed on the free magnetic layer 26.
It may be provided directly on the arrival surface (upper surface) of the sense current.

Also in the embodiments shown in FIGS. 2 to 7, the following effects are obtained by providing the current limiting layer 27 in which the insulating portion and the conductive portion are mixed on the free magnetic layer 26 as in the case of FIG. Can be expected.

That is, in the CPP type magnetic sensing element as in the present invention, the sense current flowing from the second electrode layer 33 toward the first electrode layer 20 (the first electrode layer 2 in the case of FIG. 2).
(A sense current flowing from 0 to the second electrode layer 33)
Flows through the current limiting layer 27 in a direction perpendicular to the film surface, but in the present invention, the current limiting layer 27 is filled with a conductive material film (conductive material) in a hole 56 formed in an insulating material film (insulating portion) 57. Since the part 58 is embedded, the sense current flows only in the conductive material film 58.

Therefore, the sense current flowing from the second electrode layer 33 into the free magnetic layer 26 through the current limiting layer 27 passes through the free magnetic layer 26 and the conductive material film 58.
Flows locally only in the portion facing (the current density in this portion is locally increased).

Therefore, according to the present invention, even if the element area of the free magnetic layer 26 in the direction parallel to the film surface (this element area is referred to as an optical element area) is formed to be as large as that in the conventional case, the above-mentioned A sense current flows in the free magnetic layer 26, and the element area involved in the magnetoresistive effect (this element area is referred to as an effective element area) can be reduced. Therefore, a photolithography technique having the same degree of accuracy as the conventional one is used. Even if the magnetic detection element having a large optical element size is formed, a CPP type magnetic detection element having a high reproduction output can be easily formed.

Further, in the present invention, since the optical element area is about the same as the conventional one, the external magnetic field from the recording medium can be effectively detected by the magnetic detecting element, and the reproducing characteristic with good sensitivity is excellent. A CPP type magnetic sensing element can be manufactured.

In any of the embodiments shown in FIGS. 1 to 7, the current limiting layer 27 is the free magnetic layer 26.
Of the free magnetic layer 26, the current limiting layer 27 may be provided directly or through another layer on the side opposite to the sense current reaching surface of the free magnetic layer 26. Good. However, when the current limiting layer 27 is provided on the side closer to T2 (see FIG. 1) which is a portion that substantially produces the magnetoresistive effect, the current path of the sense current can be narrowed down more appropriately, Therefore, it is possible to effectively reduce the element area and manufacture a CPP type magnetic detection element having a high reproduction output.

The current limiting layer 27 may be provided directly above or below the free magnetic layer 26 or via another layer.

FIG. 8 is a partial cross-sectional view of the magnetic sensing element of the eighth embodiment of the present invention as seen from the side facing the recording medium.

FIG. 8 shows a film structure more preferable than that of the magnetic sensor of FIGS. 1 to 7. In FIG. 8, an underlayer 70 made of a noble metal element is formed on the free magnetic layer 26, and a current limiting layer 27 is formed on the underlayer 70. A protective layer 71 made of a precious metal element is formed on the current limiting layer 27.

As described with reference to FIG. 27, in the present invention, it is important that the contrast of the conductivity between the opening (hole) and the non-opening (insulating material film) formed in the current limiting layer 27 is high. . Otherwise, the sense current flowing from the electrode layer cannot be properly narrowed down by the opening, and the apparent ΔR * A
This is because (resistance change amount * element area) cannot be improved.

That is, when the insulating material film forming the current limiting layer 27 is formed, it is necessary to form the insulating material film by aggregating like an island shape. It is necessary for the above-mentioned openings to be mixed randomly and uniformly with a fine size, but one important factor for performing such control is the material and spatter already explained in FIG. The other condition is the surface energy (γs) of the underlayer formed under the current limiting layer 27.

When the surface energy of the underlayer is high, the growth mode of the thin film is likely to be the complete wetting mode and the single layer growth (FM mode) is likely to occur. Journal of Applied Magnetics, "Introduction to Thin Film Growth Process" Vol. 14, No. 3,199
On page 528 of 0, “γs> γfs + γf” (where γ
It is described that when the relational expression of fs is the interfacial energy between the substrate and the thin film and γf is the surface energy of the thin film), a complete wetting mode is achieved and single layer growth occurs.

Therefore, in order to make it difficult to grow a single layer, that is, to form the thin film formed on the substrate in a scattered manner like islands, it is necessary to lower the substrate energy (γs). is necessary.

In view of this point, in the present invention, the underlayer 70 made of a noble metal element having a low surface energy is laid under the current limiting layer 27. The underlayer 70
It is necessary that the surface energy of the magnetic field is lower than the surface energy of the surface of the magnetic detection element formed thereunder.

When the current limiting layer 27 is formed on the underlayer 70, the insulating material film (or the layer to be the insulating material film) forming the current limiting layer 27 is the underlayer 70.
At the top, it grows by aggregating like islands. This growth mode is called Volmer-Weber (VW) type growth.

By laying a base layer 70 made of a noble metal element, for example, when a metal film is aggregated on the base layer 70 in an island shape and the metal film is oxidized to form an oxide insulating material film. The influence of the oxidation is stopped at the portion of the base layer 70, and the influence of the oxidation does not reach the layers below it.

Therefore, the insulating material film forming the current limiting layer 27 can be appropriately kept in, for example, an island shape, and the contrast between the opening and the non-opening can be kept high.

The protective layer 71 made of a noble metal element is formed on the current limiting layer 27.
By providing the current limiting layer 27, in the heat treatment step after forming the current limiting layer 27, oxygen does not diffuse into the layer on the current limiting layer 27 even if the heat treatment is performed, and an opening portion of the current limiting layer 27 is formed. The contrast with the non-opening portion can be kept high.

As described above, according to the embodiment shown in FIG.
By sandwiching the upper and lower sides of the current limiting layer 27 with layers made of a noble metal element, the contrast between the opening and the non-opening of the current limiting layer 27 can be kept high, and thus ΔR * A can be improved. Therefore, it becomes possible to manufacture a magnetic detection element having a high reproduction output and excellent reproduction characteristics.

The base layer 70 or the protective layer 71 formed above and below the current limiting layer 27 may be formed on only one of them.

Further, in the embodiment shown in FIG. 8, a protective layer 71 made of a noble metal element is formed on the current limiting layer 27.
Can also function as the second electrode layer 33, and in such a case, the second electrode layer 33 shown in FIG. 8 need not be formed.

In the present invention, the base layer 70 and / or the protective layer 71 are made of Ru, Pt, Au, Rh, Ir, P.
It is preferable that the noble metal material is formed of one or more of d, Os and Re. Alternatively, the base layer 70 and / or the protective layer 71 may be formed of Cu.

The presence of the underlayer 70 and the protective layer 71 can be seen with a transmission electron microscope (TEM).

Next, a method of manufacturing the magnetic sensing element shown in FIG. 1 will be described below with reference to the manufacturing steps shown in FIGS. 11 and 22 are partial cross-sectional views of the magnetic sensing element being manufactured as seen from the surface facing the recording medium, and FIGS. 12 to 21 show the current limiting layer formed on the free magnetic layer. It is a partial schematic diagram which shows the state etc. of the said free magnetic layer upper surface.

In the step shown in FIG. 11, the first electrode layer 20 is used.
On top, a base layer 21 made of Ta or the like, NiFeCr
A seed layer 22 formed of, for example, an antiferromagnetic layer 23 formed of PtMn, magnetic layers 51 and 53 formed of Co, and an intermediate layer 52 such as Ru formed between the magnetic layers 51 and 53. Pinned magnetic layer 2 having a three-layer ferri structure
4, non-magnetic intermediate layer 25 made of Cu or the like, Co film 5
4 and a free magnetic layer 26 formed of a magnetic layer 55 such as NiFe, and a current limiting layer 27 in which an insulating portion and a conductive portion are mixed are sequentially laminated.

Now, a method of manufacturing the current limiting layer 27 will be described with reference to FIGS.

To form the current limiting layer 27, first, an oxide film such as Al ₂ O ₃ or SiO ₂ or a nitride film such as AlN is sputter-deposited on the free magnetic layer 26. In the present invention, the oxide film may be Al, Si, Ti, Zr, H.
f, Cr, Ta, V, Nb, Mo, W, Fe, Ni, C
It is preferable to use an insulating material made of any one or two or more kinds of oxides of o.

As the nitride film, Al, Si, Ti,
Zr, Hf, Cr, Ta, V, Nb, Mo, W, Fe,
It is preferable to use an insulating material made of a nitride of one or more of Ni and Co.

These oxide film and nitride film are insulating materials which are unlikely to become a continuous film on the free magnetic layer 26, that is, can easily become a discontinuous film, depending on the film forming conditions. As shown in FIG.
As shown in (4), it means that the particles of the insulating material are likely to aggregate in the free magnetic layer 26 and easily form nuclei.

Further, in order to further improve the cohesiveness, it is important to appropriately adjust the sputtering conditions during the sputtering film formation of the insulating material.

First, the substrate temperature is lowered to about 20 to 200.degree. In addition, the distance between the substrate and the target is 200 to 30.
Separate to about 0 mm. Moreover, the gas pressure of Ar gas is 10 to 50.
It is increased to about mTorr (1.3 to 6.7 Pa).

Under the sputtering conditions described above, the atoms of the insulating material in the free magnetic layer 26 are not sufficiently surface-migrated and tend to aggregate to form nuclei.

The state in which the nuclei have grown is shown in FIG. 13. In the insulating material film thus formed on the free magnetic layer 26, a plurality of layers extending from the upper surface to the lower surface of the insulating material film are formed. A hole is formed. When the insulating material film is viewed from a plane parallel to the film surface as shown in FIG. 10,
A groove extending continuously may be formed.

Next, in the step shown in FIG. 14, a conductive material is sputter-deposited from above the insulating material film into the inside of the hole. As a result, a conductive material layer is formed in the hole from above the insulating material film, and the hole is filled with the conductive material layer.

The conductive material is α-Ta, A
Although u, Cr, Cu (copper), W (tungsten), etc. can be used, Ru, Pt, Au, Rh, Ir, Pd, O
It is preferable to use one or more precious metal materials selected from s and Re. Alternatively, Cu may be used. When a noble metal material is used, the noble metal material itself is a material that is difficult to be oxidized, and therefore it can also function as a protective layer that prevents diffusion of oxygen due to heat treatment or the like, and the opening of the current limiting layer. It is possible to maintain a high contrast between the (hole) and the non-opening portion (insulating film).

Under the sputtering conditions for the conductive material,
For example, the substrate temperature is set to about 20 to 100 ° C. Further, the distance between the substrate and the target is set to about 40 to 100 mm.
Further, the gas pressure of Ar gas is 0.5 to 10 mTorr (0.
07 to 1.3 Pa).

The current limiting layer 27 can be formed by the above manufacturing method.

In the present invention, first, Ag, Cu, Z
n, Ge, Pb, Al, Ti, Zr, Hf, Cr, T
a, V, Nb, Mo, W, Fe, Co, Si, Ni, a rare earth element, or a film made of one or more metal elements is formed by sputtering. At this time, the metal film has a lower surface. The sputtering is stopped in a state where a plurality of holes extending from the top to the top surface or a groove that continuously extends when viewed from a plane parallel to the film surface are appropriately left. Next, this metal film is oxidized. For the oxidation, natural oxidation, plasma oxidation, radical oxidation or anodic oxidation can be used.

By this oxidation step, the metal film is oxidized to become an insulating material film. Then, in a step shown in FIG. 14, a conductive material is deposited by sputtering from above the insulating material film into the inside of the hole. As a result, a conductive material layer is formed in the hole from above the insulating material film, and the hole is filled with the conductive material layer.

However, the layer under the current limiting layer is also susceptible to the oxidation due to the above-mentioned oxidation step. If, for example, the free magnetic layer is oxidized by the above-mentioned oxidation process, an oxide film is formed over the entire film surface direction, and the same problem of deterioration of contrast as described with reference to FIG. 26 occurs, which is not preferable. .

In the formation of agglomerated nuclei shown in FIG. 12, if the surface energy of the layer (free magnetic layer in FIG. 12) formed thereunder is high, the complete wetting mode is likely to occur,
Single layer growth (FM mode) is facilitated. Therefore, it is preferable to lay an underlayer made of a material having low surface energy and being hard to be oxidized before forming the current limiting layer 27.

The manufacturing method is shown in the steps shown in FIGS. As shown in FIG. 15, first, an underlayer made of a noble metal element is sputtered on the free magnetic layer.

At this time, the underlayer is made of Ru, Pt, Au,
It is preferable to use a noble metal material of one or more of Rh, Ir, Pd, Os and Re. Alternatively, the underlayer may be formed of Cu. The underlayer formed of the noble metal element has a surface energy lower than that of the surface of the free magnetic layer and is a material that is not easily oxidized.

Next, as shown in FIG. 15, Ag, Cu, Z
n, Ge, Pb, Al, Ti, Zr, Hf, Cr, T
A metal element of one or more of a, V, Nb, Mo, W, Fe, Co, Si, Ni, and a rare earth element is formed by sputtering. The metal element easily aggregates on the surface of the underlayer made of a noble metal element to form nuclei.
As shown in FIG. 5, for example, the metal film is formed by aggregating in an island shape, and the metal film is provided with a plurality of holes communicating from the lower surface to the upper surface.

Next, as shown in FIG. 16, the metal film is oxidized. For the oxidation, existing methods such as natural oxidation, plasma oxidation, radical oxidation and anodic oxidation can be used. As a result, the metal film is changed to an oxide insulating material film. At this time, since the underlayer made of a noble metal element which is difficult to be oxidized is formed under the metal film, the oxidation is stopped at the position of the underlayer, and the layers below the underlayer are not oxidized.

Then, in the step shown in FIG. 17, a conductive film made of a metal element is formed by sputtering from above the insulating material film to the holes. At this time, it is preferable that the metal element is the same precious metal element as the underlayer. That is, the conductive layer shown in FIG. 17 is formed of Ru, Pt, Au, Rh, Ir, Pd, O.
It is preferable to form the noble metal material of one or more of s and Re. Alternatively, the conductive layer may be formed of Cu.

When the conductive layer is formed using an element other than the above-mentioned noble metal element, oxygen is moved from the insulating material film to the second electrode layer or the like by the heat treatment or the like performed thereafter, and the distribution of oxygen is blurred and the opening is formed. This is because the contrast between the portion and the non-opening portion deteriorates.

Alternatively, in the present invention, a target made of an insulating material and a target made of a conductive material are prepared, and these two targets are sputtered. Thereby, the current limiting layer 27 in which the particles of the insulating material and the particles of the conductive material are mixed can be formed on the free magnetic layer 26. Although the above-mentioned materials may be used as the insulating material and the conductive material, in the present invention, the current limiting layer 27 having a film structure in which conductive particles are dispersed in the insulating material film is formed by the following materials. You can

Specifically, in the present invention, FeaMbOc (provided that the element M is Ti or Z is formed on the upper surface of the free magnetic layer 26).
r, Hf, Nb, Ta, Mo, W and one or more elements selected from rare earth elements),
The composition ratios a, b, and c are atomic%, and 40 ≦ a ≦ 50, 10 ≦
When b ≦ 30 and 20 ≦ c ≦ 40, the relationship of a + b + c = 100 is satisfied, and the film structure has fine crystal grains mainly composed of Fe dispersed in an amorphous material containing a compound of elements M and O. The current limiting layer 27 having the above described film structure is formed by sputtering.

Alternatively, on the upper surface of the free magnetic layer 26,
FedMeNf (where the element M is Ti, Zr, Hf, N
b, Ta, Mo, W, and one or more elements selected from rare earth elements), and the composition ratios d, e, and f are atomic%, and 60 ≦ d ≦ 70, 10 ≦ e ≦ 1
5, 19 ≦ f ≦ 25, the relationship of d + e + f = 100 was satisfied, and the film structure was such that fine crystal grains containing Fe as a main component were dispersed in an amorphous material containing a compound of elements M and N. The current limiting layer 27 having a film structure may be formed by sputtering.

To form these FeMO and FeMN alloys, for example, a target of Fe and a target of MO and MN are prepared, and these two targets are sputtered to obtain the above composition ratio and film structure. The current-limiting layer 27 that it has can be formed.

Alternatively, in the present invention, the current limiting layer 27 is
Co, Ru, Pt, Au, Rh, Ir, Pd, Os,
After sputter-deposition of one or more metal materials of Re, Cu, and Ag, heat treatment is performed to form C
It may be formed by oxidizing o.

However, the formation of the current limiting layer 27 made of the above-mentioned mixture of Co and the noble metal element, and FeMO and Fe
Even during the formation of the MN alloy, there is a step of performing a heat treatment to accelerate the oxidation, so that the layer below the current limiting layer 27 may be oxidized by this heat treatment.

Therefore, even when the current limiting layer 27 made of a mixture of Co and a noble metal element or the current limiting layer 27 made of FeMO or FeMN alloy, that is, the current limiting layer 27 made of these so-called granular films is formed, the steps shown in FIG. As described above, it is preferable to first form an underlayer made of a noble metal element on the free magnetic layer 27. It is preferable that the underlayer is formed of one or more precious metal materials selected from Ru, Pt, Au, Rh, Ir, Pd, Os, and Re. Alternatively, the underlayer may be formed of Cu. However, it is preferable to use a noble metal.

In the step shown in FIG. 18, a current limiting layer 27 made of FeMO or FeMN alloy is formed by sputtering on the underlayer made of the noble metal element. Further, it is preferable to form a protective layer made of a noble metal element on the current limiting layer 27, like the underlayer. When the heat treatment is performed after forming the underlayer, the current limiting layer and the protective layer, granular phase separation of the current limiting layer proceeds, and the contrast between the oxidized portion and the non-oxidized portion is increased. At this time, since the upper and lower sides of the current limiting layer are sandwiched by the layers made of a noble metal element, the oxidation does not reach the upper and lower layers of the current limiting layer.

In the step shown in FIG. 19, an underlayer made of a noble metal element is sputter-deposited on the free magnetic layer, and C is formed thereon.
o, Ru, Pt, Au, Rh, Ir, Pd, Os, R
A material obtained by mixing any one of e, Cu, and Ag or a mixture of two or more kinds of metallic materials is formed by sputtering. afterwards,
Anneal to promote phase separation. In the step shown in FIG. 20, natural oxidation, plasma oxidation, radical oxidation, etc. are performed to oxidize mainly Co portion composed of a base substance. On the other hand, the noble metal particles formed of Au or the like are not oxidized and remain as conductive particles.

Even during this heat treatment and oxidation, since the underlayer made of a noble metal element is provided below the current limiting layer, the oxidation does not reach the layer below the current limiting layer.

In the step shown in FIG. 21, a protective layer made of a noble metal element is formed on the current limiting layer by sputtering. By thus capping the current limiting layer also with the protective layer made of a noble metal element, oxygen is diffused into the layer formed on the current limiting layer even if heat treatment or the like is subsequently performed. Therefore, it is possible to maintain a good contrast between the oxidized portion and the non-oxidized portion of the current limiting layer.

What can be said in both of the steps shown in FIGS. 18 and 19 is that the film thickness of the current limiting layer is smaller than the particle size of the conductive particles contained therein. Otherwise, the current path through which the sense current flows from the upper surface to the lower surface of the current limiting layer is not properly formed, and the current path of the sense current cannot be satisfactorily narrowed to improve the reproduction output.

When a protective layer made of a noble metal element is provided on the current limiting layer as in the step shown in FIGS. 18 and 21, this protective layer itself can function as the second electrode layer. In the above step, the formation of the second electrode layer is not necessary and the manufacturing process can be simplified.

In the steps shown in FIGS. 15 to 21,
Although the insulating material film made of oxide is formed by performing the oxidation step, it may be nitrided.

Next, in the step shown in FIG. 11, a resist layer 44 is formed on the current limiting layer 27. The resist layer 44 may be a lift-off resist layer.

The area of the lower surface 44a of the resist layer 44 is formed to be about the same as or slightly smaller than the optical element area of the magnetic detection element. In the present invention, the track width Tw determined by the width dimension of the upper surface of the free magnetic layer 26 in the track width direction (X direction in the drawing) is 0.15 to 0.3 μm.
And the length MRh in the height direction (Y direction in the drawing) is set to 0.1.
5 to 0.3 .mu.m, so that the optical element area can be increased to 0.02 to 0.09 .mu.m @ 2.

The above-mentioned optical element area is about the same as the conventional one, and in the present invention, the magnetic detection element can be manufactured by using the photolithography technique having the same accuracy as the conventional one.

Next, as shown in FIG. 11, the underlying layer 21 to the current limiting layer 27 which are not covered with the resist layer 44.
The multilayer film 28 up to is removed by ion milling or the like from the direction of arrow F (dotted line portion shown in FIG. 11). As a result, in the center of the upper surface of the first electrode layer 20, the multilayer film 28 including the base layer 21 to the current limiting layer 27 is left in a substantially trapezoidal shape. After the ion milling, a part of the substance removed by the milling is redeposited on both end faces of the multilayer film 28. Therefore, it is preferable to remove the redeposited substance by the side milling.

Next, in the step shown in FIG. 22, an insulating layer 29 made of Al 2 O 3 or the like, a bias layer made of Cr or the like is formed from above the first electrode layer 20 to both end faces 28 a of the multilayer film 28. A ground layer 30, a hard bias layer 31 formed of CoPtCr, and an insulating layer 32 formed of Al2O3 are formed by sputtering.

As shown in FIG. 22, the insulating layer 29 is
To the insulating layer 32, the irradiation angle of the sputtered particles during the sputter deposition of each layer is substantially perpendicular to the substrate in the direction G.
It is preferable that

As shown in FIG. 22, the insulating layer 29b and the bias base material layer 30 are also formed on the resist layer 44.
a, the bias material layer 31a, and the insulating material film 32a are laminated.

After laminating the insulating layers 29 to 32 on both side regions of the multilayer film 28, the resist layer 44 is removed, but the entire surface of the resist layer 44 is
When the resist layer 44 is covered with the above-mentioned insulating layer 29b or the like, the resist layer 44 cannot be properly removed. Therefore, for example, scrub cleaning, specifically, dry ice particles or the like covers the surface of the resist layer 44. Part of the insulating layer 29b is removed by colliding with each layer such as the insulating layer 29b.
After partially exposing the surface of No. 4, the resist layer 44 may be dipped in a solvent to dissolve and remove the resist layer 44.

After the resist layer 44 is removed, unnecessary burrs such as the insulating layer 29b may remain on the upper surface of the current limiting layer 27 from the insulating layer 32. It is preferable to scrub the current limiting layer 27, for example, to remove the burrs and form a clean surface. For the scrub cleaning, for example, a method of causing dry ice particles to collide with the burr can be considered.

Then, a second electrode layer 33 is formed by sputtering from the insulating layer 32 to the current limiting layer 27 (see FIG. 1).

A method of manufacturing another magnetic detection element will be briefly described. In the magnetic sensing element shown in FIG. 2, after the current limiting layer 27, the free magnetic layer 26, the nonmagnetic intermediate layer 25, the pinned magnetic layer 24, and the antiferromagnetic layer 23 are formed on the first electrode layer 20 by sputtering. 11, a resist layer 44 is formed on the antiferromagnetic layer 23, and the multilayer film 34 not covered with the resist layer 44 is removed by ion milling. Next, an insulating layer 35, a bias underlayer 30, a hard bias layer 31, and an insulating layer 36 are formed by sputtering from above the first electrode layer 20 to both end faces 34a of the multilayer film 34, and the resist layer 44 is removed. To do. A second layer is formed from the insulating layer 36 to the antiferromagnetic layer 23.
The electrode layer 33 is formed.

In the magnetic sensing element shown in FIG. 3, the underlayer 21, the seed layer 22, the antiferromagnetic layer 23, the pinned magnetic layer 24, the nonmagnetic intermediate layer 25, and the free magnetic layer 26 are provided on the first electrode layer 20. , And after forming the current limiting layer 27, the same resist layer 44 as in FIG. 11 is formed on the current limiting layer 27, and the multilayer film 28 not covered with the resist layer 44 is removed by ion milling. To do. Next, the re-deposited matter attached to both end surfaces 28a of the multilayer film 28 by the ion milling is scraped off by the side milling.

Next, from the top of the first electrode layer 20 to the both end surfaces 28a of the multilayer film 28, the specular film 3 is formed.
7 is formed by sputtering. The specular film 37 is formed by sputtering from an oblique direction with respect to the substrate. It is preferable that the irradiation angle of the sputtered particles at the time of the sputtering is inclined by about 20 to 70 ° from the direction perpendicular to the substrate surface.

Next, an insulating layer 29, a bias underlayer 30, a hard bias layer 31, and an insulating layer 32 are formed by sputtering on the specular film 37, the resist layer 44 is removed, and the insulating layer 32 is further removed. From the current limiting layer 2
The second electrode layer 33 is formed on the upper surface of the electrode 7.

In the method of manufacturing the magnetic sensing element shown in FIG. 4, first, the underlying layer 21 and the seed layer 2 are formed on the first electrode layer 20.
2, antiferromagnetic layer 23, pinned magnetic layer 24, non-magnetic intermediate layer 2
5, after continuously forming the free magnetic layer 26, the intermediate layer 38, the hard bias layer 39, and the current limiting layer 27 by sputtering,
By using the resist layer 44 shown in FIG.
The multilayer film 41 not covered with 4 is removed by ion milling. Next, the re-deposited matter attached to both end surfaces 41a of the multilayer film 41 by the ion milling is scraped off by the side milling.

Next, from the top of the first electrode layer 20 to both end faces 41a of the multilayer film 41, the specular film 3 is formed.
7 is formed by sputtering. The specular film 37 is formed by sputtering from an oblique direction with respect to the substrate. It is preferable that the ion irradiation angle at the time of sputtering is inclined by about 20 to 70 ° from the direction perpendicular to the substrate surface.

Next, after the insulating layer 40 is formed by sputtering on the specular film 37, the resist layer 44 is removed, and the second electrode layer 33 is formed from the insulating layer 40 to the current limiting layer 27. To form.

In the method of manufacturing the magnetic sensing element shown in FIG. 5, first, the underlayer 21 and the seed layer 2 are formed on the first electrode layer 20.
2, antiferromagnetic layer 23, pinned magnetic layer 24, non-magnetic intermediate layer 2
5, the free magnetic layer 26, the current limiting layer 27, and the hard bias layer 39 are continuously sputtered, and then the resist layer 44 shown in FIG. 11 is used to ionize the multilayer film 41 not covered with the resist layer 44. Remove by milling.

Next, from the top of the first electrode layer 20 to both end faces 41a of the multilayer film 41, the specular film 3 is formed.
7 is formed by sputtering. And the specular film 37
After the insulating layer 40 is sputtered thereon, the resist layer 44 is removed, and the second electrode layer 33 is formed from the insulating layer 40 to the hard bias layer 39.

In the method of manufacturing the magnetic sensing element shown in FIG. 6, first, the underlying layer 21 and the seed layer 2 are formed on the first electrode layer 20.
2, antiferromagnetic layer 23, pinned magnetic layer 24, non-magnetic intermediate layer 2
After the free magnetic layer 26 having a five- and three-layer ferri structure and the current limiting layer 27 are continuously sputtered, the resist layer 44 shown in FIG. 11 is used to form the multilayer film 42 not covered with the resist layer 44. Remove by ion milling.

Next, after the insulating layer 29, the bias underlayer 30, the hard bias layer 31, and the insulating layer 32 are continuously sputtered from the first electrode layer 20 to the both end surfaces 42a of the multilayer film 42, The resist layer 44 is removed, and a second electrode layer 33 is formed on the insulating layer 32 and the current limiting layer 27.

In the method of manufacturing the magnetic sensing element shown in FIG. 7, first, the underlying layer 21 and the seed layer 2 are formed on the first electrode layer 20.
2, antiferromagnetic layer 23, pinned magnetic layer 24, non-magnetic intermediate layer 2
5, the free magnetic layer 26, the non-magnetic intermediate layer 59, the pinned magnetic layer 63, the antiferromagnetic layer 64, and the current limiting layer 27 are continuously sputtered, and then the resist layer 44 shown in FIG.
The multilayer film 43 not covered with the resist layer 44 is removed by ion milling.

Next, an insulating layer 29, a bias underlayer 30, a hard bias layer 31, and an insulating layer 32 are continuously sputtered from the first electrode layer 20 to both end faces of the multilayer film 43, and then The resist layer 44 is removed, and then the second electrode layer 33 is formed on the insulating layer 32 and the current limiting layer 27.

In the method of manufacturing the magnetic sensing element shown in FIG. 8, first, the underlying layer 21 and the seed layer 2 are formed on the first electrode layer 20.
2, antiferromagnetic layer 23, pinned magnetic layer 24, non-magnetic intermediate layer 2
5, free magnetic layer 26, underlayer 7 made of a noble metal element
0, the current limiting layer 27, and the protective layer 71 made of a noble metal element are continuously sputtered, and then the resist layer 44 shown in FIG.
Is used to remove the multilayer film 41 not covered with the resist layer 44 by ion milling. The method for forming the underlayer 70, the current limiting layer 27, and the protective layer 71 made of a noble metal element has been described in detail with reference to FIGS. 15 to 21, so please refer to that.

Next, an insulating layer 29, a bias underlayer 30, a hard bias layer 31, and an insulating layer 32 are continuously sputtered from above the first electrode layer 20 to both end faces of the multilayer film 43, and then the above-mentioned process is performed. The resist layer 44 is removed, and a second layer is formed on the insulating layer 32 and the protective layer 71.
The electrode layer 33 is formed.

In the method for manufacturing a magnetic sensing element according to the present invention described above, the current limiting layer 27 can be easily formed, the effective element size can be effectively narrowed, and the reproduction output can be improved. It is possible to manufacture a magnetic detection element capable of improving the magnetic field. In particular, the current limiting layer 2
By providing an underlayer made of a noble metal element under 7, the nuclei can be formed in a more aggregated manner, so that the contrast between the openings and non-openings of the insulating material film can be increased, and at the same time, oxidation by heat treatment or the like can be performed. Even if the process is performed, the oxidation can be stopped by the underlayer, and the influence of the oxidation on the layer below can be prevented. Further, it is preferable to provide a protective layer made of a noble metal element also on the current limiting layer 27 because it is possible to prevent the influence of oxidation on the layer above the current limiting layer.

Further, in the manufacturing method of the present invention, the track width Tw and the length MRh in the height direction of the magnetic detection element can be made the same as in the conventional case, so that the photolithography technique having the same accuracy as in the conventional case can be used. By using this, it is possible to easily form a magnetic detection element having a small effective element size.

The magnetic detecting element according to the present invention can be used not only for the thin film magnetic head mounted in the hard disk device, but also for the magnetic head for tape, the magnetic sensor and the like.

[0287]

According to the present invention described in detail above, a current limiting layer in which an insulating portion and a conductive portion are mixed is provided at least on the surface of the free magnetic layer on which the sense current reaches, either directly or through another layer. It is provided.

Therefore, the sense current flows vertically in the current limiting layer, but in the present invention, the current provided directly to the surface of the free magnetic layer on which the sense current reaches or through another layer. Since the limiting layer has a structure in which the insulating portion and the conductive portion are mixed, the sense current flows only in the conductive portion.

Therefore, the sense current flowing from the electrode layer into the free magnetic layer through the current limiting layer locally flows only in the portion of the free magnetic layer facing the conductive portion (current density in this portion). Will be locally high).

Therefore, according to the present invention, even if the element area of the free magnetic layer in the direction parallel to the film surface (this element area is referred to as an optical element area) is formed to be as large as the conventional one, the free magnetic layer is actually free. A sense current flows in the magnetic layer, and the element area involved in the magnetoresistive effect (this element area is called the effective element area) can be reduced. Even if the magnetic detection element having a large element size is formed, a CPP type magnetic detection element having a high reproduction output can be easily formed.

Further, since the element size can be formed to be as large as the conventional one, it is possible to effectively detect the external magnetic field from the recording medium by the magnetic detection element, improve the reproduction output, and stabilize the reproduction waveform. Can be improved.

Further, in the present invention, by providing an underlayer made of a noble metal element under the current limiting layer, the nuclei can be more aggregated and formed. Therefore, the contrast between the opening and the non-opening of the insulating material film can be improved. At the same time, it is possible to prevent the oxidation from being stopped by the base layer even when a process such as heat treatment is performed, and to prevent the underlying layer from being affected by the oxidation. Further, it is preferable to provide a protective layer made of a noble metal element also on the current limiting layer, since it is possible to prevent the layer above the current limiting layer from being affected by oxidation.

Since the contrast between the opening and the non-opening of the current limiting layer can be increased in this way, the current path of the sense current can be appropriately narrowed down by the current limiting layer, and the reproduction output can be effectively obtained. It becomes possible to manufacture a large magnetic detection element.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of a magnetic detection element according to a first embodiment of the present invention as viewed from a side facing a recording medium,

FIG. 2 is a partial cross-sectional view of a magnetic detection element according to a second embodiment of the present invention as seen from the side facing a recording medium,

FIG. 3 is a partial cross-sectional view of a magnetic detection element according to a third embodiment of the present invention as seen from a side facing a recording medium,

FIG. 4 is a partial cross-sectional view of a magnetic detection element according to a fourth embodiment of the present invention as viewed from the side facing a recording medium,

FIG. 5 is a partial cross-sectional view of a magnetic detection element according to a fifth embodiment of the present invention as viewed from the side facing a recording medium,

FIG. 6 is a partial cross-sectional view of a magnetic detection element according to a sixth embodiment of the present invention as seen from the side facing a recording medium,

FIG. 7 is a partial cross-sectional view of a magnetic detection element according to a seventh embodiment of the present invention as seen from the side facing a recording medium,

FIG. 8 is a partial cross-sectional view of a magnetic detection element according to an eighth embodiment of the present invention as seen from the side facing a recording medium,

FIG. 9 is a partial schematic view showing a film configuration of a multilayer film and a current limiting layer in the present invention,

FIG. 10 is a partial schematic view showing a film structure of another multilayer film and a current limiting layer in the present invention,

FIG. 11 is a process chart showing the method of manufacturing the thin film magnetic head shown in FIG.

FIG. 12 is a schematic view showing a state of the upper surface of the free magnetic layer when an electrode limiting layer is formed on the free magnetic layer,

13 is a partial schematic diagram showing the next state of FIG. 12,

FIG. 14 is a partial schematic diagram showing the next state of FIG. 13;

FIG. 15 is a schematic diagram showing a state of the upper surface of the free magnetic layer when an underlayer is formed on the free magnetic layer and an electrode limiting layer is formed on the underlayer;

16 is a partial schematic diagram showing the next state of FIG. 15,

FIG. 17 is a partial schematic diagram showing the next state of FIG. 16;

FIG. 18 is a view showing an upper surface of the free magnetic layer when an underlayer is formed on the free magnetic layer, a current limiting layer (granular film) is formed on the underlayer, and a protective layer is further formed on the current limiting layer. A schematic diagram showing the state,

FIG. 19 is a view showing an upper surface of the free magnetic layer when an underlayer is formed on the free magnetic layer, a current limiting layer (granular film) is formed on the underlayer, and a protective layer is further formed on the current limiting layer. A schematic diagram showing the state,

FIG. 20 is a partial schematic diagram showing the next state of FIG. 19;

FIG. 21 is a partial schematic diagram showing the next state of FIG. 20;

22 is a process chart performed after the step of FIG. 11,

FIG. 23 is a partial cross-sectional view of a conventional magnetic detection element seen from the side facing a recording medium,

FIG. 24 is a partial schematic view of a CIP type magnetic sensing element,

FIG. 25 is a partial schematic view of a CPP type magnetic sensing element,

FIG. 26 is a partial schematic view showing an example in which the contrast between the opening and the non-opening of the current limiting layer is poor.

FIG. 27 is a partial schematic diagram showing an example in which the contrast between the opening and the non-opening of the current limiting layer is good,

[Explanation of symbols]

20 First electrode layer 21 Underlayer 22 Seed layer 23 Antiferromagnetic layer 24, 63 pinned magnetic layer 25 Non-magnetic intermediate layer 26 Free magnetic layer 27 Current limiting layer 28, 34, 41, 42, 43 Multilayer film 29, 32, 40 Insulation layer 31, 39 Hard bias layer 33 Second electrode layer 37 Specular membrane 38 Middle class 44 resist layer 56 holes 57 Insulating material film 58 Conductive material film 68 groove 70 Underlayer 71 Protective layer

Claims (37)

[Claims] 1. A magnetic sensing element comprising a multilayer film having an antiferromagnetic layer, a pinned magnetic layer, a non-magnetic intermediate layer and a free magnetic layer, wherein a current flows in a direction perpendicular to the film surface of each layer of the multilayer film. A magnetic detection element, wherein a current limiting layer in which an insulating portion and a conductive portion are mixed is provided on at least one of the upper surface and the lower surface of the free magnetic layer directly or via another layer. 2. The magnetic detecting element according to claim 1, wherein a noble metal material layer is formed on either one or both of the lower surface and the upper surface of the current limiting layer. 3. The noble metal material layer is made of Ru, Pt, A
3. A noble metal material containing at least one of u, Rh, Ir, Pd, Os and Re.
The magnetic detection element described. 4. The magnetic detection element according to claim 2, wherein a Cu layer is formed instead of the noble metal material layer. 5. The magnetic sensing element according to claim 1, wherein the current limiting layer is provided at least on the current reaching surface side of the free magnetic layer, either directly or via another layer. 6. The insulating portion of the current limiting layer is an insulating material film provided with a plurality of holes communicating at least from the upper surface to the lower surface of the current limiting layer, and the conductive portion serving as the conductive portion is provided in the holes. The magnetic detection element according to claim 1, wherein a film of a permeable material is embedded. 7. The insulating portion of the current limiting layer has a groove that extends continuously when viewed from a plane parallel to the film surface, and the groove extends from the upper surface to the lower surface of the current limiting layer. The magnetic detection element according to claim 1, wherein the magnetic detection element is formed, and a conductive material serving as the conductive portion is embedded in the groove. 8. The insulating portion of the current limiting layer extends continuously from a hole extending from the upper surface to the lower surface of the current limiting layer when viewed from a plane parallel to the film surface, The magnetic detection element according to claim 1, wherein the magnetic material is an insulating material film in which a groove communicating from an upper surface to a lower surface is mixed, and a conductive material serving as the conductive portion is embedded in the hole and the groove. . 9. The magnetic sensing element according to claim 6, wherein the insulating material film is formed of an oxide film or a nitride film. 10. The oxide film is made of Ag, Cu, Zn, G
e, Pb, Al, Ti, Zr, Hf, Cr, Ta, V,
The magnetic sensing element according to claim 9, which is formed of an insulating material made of an oxide of any one or more of Nb, Mo, W, Fe, Co, Si, Ni, and a rare earth element. 11. The nitride film is made of Ag, Cu, Zn, G
e, Pb, Al, Ti, Zr, Hf, Cr, Ta, V,
The magnetic sensing element according to claim 9, wherein the magnetic sensing element is made of an insulating material made of a nitride of any one or more of Nb, Mo, W, Fe, Co, Si, Ni, and a rare earth element. 12. The conductive part of the current limiting layer is a conductive particle, and the conductive particle is dispersed in an insulating material layer serving as the insulating part. Magnetic detection element. 13. The current limiting layer comprises fine particles of Ti, Zr, Hf, and N containing Fe as a main component and serving as the conductive portion.
A film structure in which a film is dispersed in an amorphous material that forms the insulating portion and contains a compound of one or more elements M selected from b, Ta, Mo, W and rare earth elements and O or N. Item 12. The magnetic sensor according to item 12. 14. The current limiting layer has a composition formula of FeaMbOc, and composition ratios a, b, and c are atomic% and 40 ≦ a ≦.
50, 10 ≦ b ≦ 30, 20 ≦ c ≦ 40, and a + b
The magnetic detection element according to claim 12, wherein the relationship of + c = 100 is satisfied. 15. The current limiting layer has a composition formula of FedMeNf, and composition ratios d, e, and f are atomic%, and 60 ≦ d ≦.
70, 10 ≦ e ≦ 15, 19 ≦ f ≦ 25, and d + e
The magnetic detection element according to claim 12, wherein the relationship of + f = 100 is satisfied. 16. The insulating material film is a layer in which Co is mainly oxidized, and Ru, Pt, A is contained in the insulating material film.
The magnetic detection element according to claim 12, wherein conductive particles formed of a metal material of one or more of u, Rh, Ir, Pd, Os, Re, Cu, and Ag are dispersed. 17. The insulating part of the current limiting layer is an insulating particle, and the insulating particle is dispersed in a conductive material film to be the conductive part. The magnetic detection element described. 18. A method of manufacturing a magnetic sensing element, comprising the following steps. (A) From the bottom, a first electrode layer, an antiferromagnetic layer, a pinned magnetic layer,
A non-magnetic intermediate layer and a free magnetic layer are laminated in this order, and an insulating material film is sputtered on the upper surface of the free magnetic layer. At this time, the insulating material film is formed on the upper surface of the insulating material film from the upper surface. A step of forming a plurality of holes extending to the lower surface, and (b) forming a conductive material film on the insulating material film by sputtering, and forming the conductive material film inside the holes formed in the insulating material film at this time. And (c) forming a second electrode layer on the current limiting layer composed of the insulating material film and the conductive material film. 19. The method of manufacturing a magnetic sensing element according to claim 18, wherein in the step (a), a base layer made of a noble metal element is formed, and then the insulating material film is formed on the base layer. 20. The underlayer is made of Ru, Pt, Au, R
20. The method for manufacturing a magnetic sensing element according to claim 19, wherein the magnetic sensing element is formed of one or more precious metal materials selected from h, Ir, Pd, Os, and Re. 21. The method of manufacturing a magnetic sensing element according to claim 18, wherein in the step (a), an underlayer made of Cu is formed, and then the insulating material film is formed on the underlayer. 22. When the insulating material film is formed by sputtering in the step (a), the insulating material film is formed as a discontinuous film on the free magnetic layer or the underlying layer. A method for manufacturing a magnetic detection element according to any one of 1. 23. The insulating material film is formed of Al, Si, T
i, Zr, Hf, Cr, Ta, V, Nb, Mo, W, F
e, Ni, Co is sputter-deposited with an insulating material composed of one or more oxides, and at this time, a plurality of holes or film planes communicating from the lower surface to the upper surface are formed in the insulating material film. 23. The method of manufacturing a magnetic detection element according to claim 22, wherein the sputtering is stopped in a state where a groove extending continuously when viewed from a plane is left. 24. When forming the insulating material film in the step (a), first, Ag, Cu, Zn, Ge, Pb, Al,
Ti, Zr, Hf, Cr, Ta, V, Nb, Mo, W,
Any one of Fe, Co, Si, Ni, and rare earth elements
A film formed of one kind or two or more kinds of metal elements is formed by sputtering, and a plurality of holes extending from the lower surface to the upper surface of the film formed of the metal element or grooves that continuously extend when viewed from a plane parallel to the film surface 23. The method of manufacturing a magnetic sensing element according to claim 22, wherein the sputtering is stopped in the state where the oxide is left, the film made of the metal element is then oxidized, and the oxide film is used as an insulating material film. 25. The insulating material film is formed of Al, Si, T
i, Zr, Hf, Cr, Ta, V, Nb, Mo, W, F
e, Ni, Co are sputter-deposited with an insulating material composed of one or more nitrides, and at this time, the insulating material film has a plurality of holes extending from the lower surface to the upper surface or parallel to the film surface. 23. The method of manufacturing a magnetic detection element according to claim 22, wherein the sputtering is stopped in a state where a groove extending continuously when viewed from a plane is left. 26. When forming the insulating material film in the step (a), first, Ag, Cu, Zn, Ge, Pb, Al,
Ti, Zr, Hf, Cr, Ta, V, Nb, Mo, W,
Any one of Fe, Co, Si, Ni, and rare earth elements
A film formed of one kind or two or more kinds of metal elements is formed by sputtering, and a plurality of holes extending from the lower surface to the upper surface of the film formed of the metal element or grooves that continuously extend when viewed from a plane parallel to the film surface 23. The method for manufacturing a magnetic sensing element according to claim 22, wherein the sputtering is stopped in the state where the metal is left, and then the film made of the metal element is nitrided, and the nitride film is used as an insulating material film. 27. A method of manufacturing a magnetic sensing element, comprising the following steps. (D) From the bottom, the first electrode layer, the antiferromagnetic layer, the pinned magnetic layer,
A multilayer film is laminated in the order of a non-magnetic intermediate layer and a free magnetic layer, and FeaMbOc is further formed on the upper surface of the free magnetic layer.
(However, the element M is Ti, Zr, Hf, Nb, Ta, M
O, W and one or more elements selected from rare earth elements), and the composition ratios a, b and c are atomic%
40 ≦ a ≦ 50, 10 ≦ b ≦ 30, 20 ≦ c ≦ 40
Where a + b + c = 100 is satisfied, and fine crystal grains containing Fe as a main component are dispersed in an amorphous material containing a compound of elements M and O to form a current limiting layer by sputtering. A step of forming a film, and (e) a second layer on the current limiting layer.
Forming an electrode layer of. 28. The heat treatment of the current limiting layer.
7. The method for manufacturing the magnetic detection element according to 7. 29. Instead of FeaMbOc in the step (d), FedMeNf (provided that the element M is Ti, Zr, H
f, Nb, Ta, Mo, W, and one or more elements selected from rare earth elements), and the composition ratios d, e, and f are atomic%, 60 ≦ d ≦ 70, 10 ≦ e
In the case of ≦ 15, 19 ≦ f ≦ 25, a relationship of d + e + f = 100 is satisfied, and fine crystal grains containing Fe as a main component are dispersed in an amorphous material containing a compound of the elements M and N. 29. The method for manufacturing a magnetic sensing element according to claim 27, wherein the current limiting layer is formed by sputtering. 30. In place of FeaMbOc in the step (d), the current limiting layer is made of Co, Ru, Pt, Au, Rh,
Any one of Ir, Pd, Os, Re, Cu, Ag
28. The method for producing a magnetic sensing element according to claim 27, wherein the film is formed by sputtering a material containing one kind or two or more kinds of metal elements and then oxidizing the Co by heat treatment. 31. The magnetic layer according to claim 27, wherein in the step (d), an underlayer made of a noble metal material is formed on the upper surface of the free magnetic layer before forming the current limiting layer. Manufacturing method of detection element. 32. The base layer is made of Ru, Pt, Au, R
32. The method of manufacturing a magnetic sensing element according to claim 31, wherein the method is formed of a noble metal material of at least one of h, Ir, Pd, Os, and Re. 33. The magnetic detection according to claim 27, wherein in the step (d), an underlayer made of Cu is formed on the upper surface of the free magnetic layer before forming the current limiting layer. Device manufacturing method. 34. After forming the current limiting layer, Pt, Au, Rh, Ir, Pd, Os, and
34. The method for manufacturing a magnetic sensing element according to claim 18, wherein a protective layer made of one or more precious metal materials of Re is formed. 35. After forming the current limiting layer, a protective layer made of Cu is formed on the upper surface of the current limiting layer.
38. A method for manufacturing a magnetic detection element according to any one of 8 to 33. 36. The method for manufacturing a magnetic sensing element according to claim 34, wherein the protective layer is a second electrode layer. 37. From the bottom, a first electrode layer, a current limiting layer,
37. The method for manufacturing a magnetic sensing element according to claim 18, wherein a multilayer film is laminated in the order of a free magnetic layer, a non-magnetic intermediate layer, a pinned magnetic layer and an antiferromagnetic layer.