JP2003318462A - Magnetoresistance effect element and magnetic head and magnetic memory using the element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetoresistance effect element (MR element) including an antiferromagnetic layer, a fixed magnetic layer, a non-magnetic layer, and a free magnetic layer, capable of holding a high soft magnetic characteristic even when the MR element is miniaturized and having heat resistance corresponding to a manufacturing process of a high temperature and to provide a magnetic head of high sensitivity and high output and a magnetic memory (MRAM) of high density. <P>SOLUTION: A Ni-Fe-X alloy layer is laminated at least on one face of a multilayer film unit including the antiferromagnetic layer, the fixed magnetic layer, the non-magnetic layer, and the free magnetic layer to provide the MR element suppressing the deterioration of the soft magnetic characteristic of the free magnetic layer and having heat resistance. Further the magnetic head of high sensitivity and high output and the MRAM of high density can be provided by using the MR element. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetoresistive effect element (hereinafter referred to as "MR element"), a magnetic head and a magnetic memory which are magnetic devices using the same. The MR element of the present invention is suitable for high density magnetic recording / reproducing heads used for media such as magnetic disks, magneto-optical disks and magnetic tapes, magnetic sensors used for automobiles, and magnetic random access memories. ing.

[0002]

2. Description of the Related Art In recent years, the magnetoresistive effect (MR effect) based on the conduction phenomenon depending on the spin of electrons has been used in a magnetic head and a magnetic random access memory (MRA).
M)) etc. are being actively developed. The MR effect is a phenomenon in which a resistance value varies depending on the relative angle of the magnetization directions of the magnetic layers adjacent to each other in the multilayer film including the structure of [magnetic layer / nonmagnetic layer / magnetic layer]. . Generally, the resistance value is smallest when the magnetization directions are parallel, and conversely, the resistance value is largest when anti-parallel. An element utilizing such an MR effect is called an MR element. Among MR elements, those using a conductive material such as Cu as the non-magnetic layer are called GMR elements. The GMR element is one in which an electric current flows parallel to the film surface (CIP-GMR: Cu
rrent In Plane-GMR) and one that allows current to flow perpendicularly to the film surface (CPP-GMR: Current Perpendicular to Pla
ne-GMR). An MR element using an insulating material such as Al ₂ O _{3 for} the non-magnetic layer is called a TMR element. TMR
In the element, the higher the spin polarizability of the magnetic layers sandwiching the non-magnetic layer, the larger the magnetoresistance change rate (MR ratio) can be obtained. At present, this TMR element is expected as an MR element exhibiting a large MR ratio.

MR such as GMR element and TMR element
An MR element called a spin valve type has been proposed in order to use the element as a device that operates in a minute magnetic field. In the spin-valve MR element, the magnetization direction of one magnetic layer (fixed magnetic layer) sandwiching the non-magnetic layer is fixed by the exchange bias magnetic field from the antiferromagnetic layer containing the antiferromagnetic material. On the other hand, the other magnetic layer (free magnetic layer)
Since the magnetization direction of can move freely with respect to the external magnetic field, the relative angle of the magnetization direction between the fixed magnetic layer and the free magnetic layer can be easily changed. Such a spin-valve MR element has already been applied to a magnetic head in a GMR element, and a spin-valve MR element using a TMR element, which has a higher output than a GMR element, is used in a next-generation magnetic head or a high-density magnetic head. It is expected to be applied to MRAM and the like.

[0004]

In order to apply the spin valve MR element to a device such as a magnetic head or MRAM, it is necessary to further improve and stabilize the output. Further, the element is required to have heat resistance capable of withstanding the manufacturing process of the device. For example, in the process of manufacturing a magnetic head, heat treatment is generally performed at about 250 ° C to 300 ° C. When mounted on a hard disk drive (HDD), the operating environment temperature (for example, about 150 ℃)
It is required to operate stably for a long time. Further, researches are underway to manufacture MR elements on CMOS and apply them as MRAM devices, but in the CMOS manufacturing process, it is inevitable to perform heat treatment at a higher temperature (400 ° C. to 450 ° C.).

In order to improve the output of the device, reducing the film thickness of the free magnetic layer to reduce the amount of magnetization and improving the sensitivity to an external magnetic field are effective means. However, this method may cause problems such as deterioration of the soft magnetic properties (coercive force, anisotropic magnetic field, etc.) of the free magnetic layer.
Further, when high-temperature heat treatment is performed, interface diffusion occurs between the free magnetic layer and a layer adjacent to the free magnetic layer, or the fine structure of the magnetic film forming the free magnetic layer changes, Similarly, the soft magnetic properties of the free magnetic layer may deteriorate. When the soft magnetic characteristics of the free magnetic layer deteriorate, the output of the element decreases and it becomes difficult to apply it to a device.

In addition, miniaturization of the MR element is required to increase the capacity of the MRAM. However, when the element area is reduced, the coercive force of the free magnetic layer generally increases and the output of the element decreases. To do. In order to reduce the increased coercive force, it is effective to reduce the film thickness of the free magnetic layer to reduce the amount of magnetization, but when the film thickness is reduced, the same problem as in the above example occurs. there is a possibility.

As described above, when the spin-valve MR element is applied to a magnetic head or MRAM, the output of the element,
At the same time as the free magnetic layer becomes thinner due to improved sensitivity and miniaturization, heat resistance of the device becomes a major issue.

Therefore, an object of the present invention is to provide an MR element having good soft magnetic characteristics even when the thickness of the magnetic layer is thin, high output and excellent heat resistance. It is another object of the present invention to provide a magnetic head and a magnetic memory using the MR element.

[0009]

In order to achieve the above object, a magnetoresistive effect element of the present invention comprises an antiferromagnetic layer, a fixed magnetic layer magnetically coupled to the antiferromagnetic layer, and a nonmagnetic layer. A multi-layer unit including a layer and a free magnetic layer in which the magnetization direction is more easily rotated than the pinned magnetic layer, is formed on the substrate, and the pinned magnetic layer and the free magnetic layer are interposed via the non-magnetic layer. A magnetoresistive effect element including a structure in which and are laminated, wherein at least one surface of the multilayer film unit has a Ni
-It is characterized by including a structure in which Fe-X alloy layers are laminated. However, X is Cr, V, Nb, Pt, Pd, Rh, Ru, Ir, Cu
And at least one element selected from Au.

With the above-mentioned structure, it is possible to obtain an MR element having good soft magnetic characteristics, high output and excellent heat resistance even when the magnetic layer has a small thickness.

A magnetic head of the present invention comprises the magnetoresistive effect element described above and a magnetic shield for limiting introduction of a magnetic field other than the magnetic field to be detected by the magnetoresistive effect element into the element. Is characterized by. Further, the magnetic head of the present invention, the magnetoresistive effect element described above,
A yaw for introducing a magnetic field to be detected into the magnetoresistive effect element.
It may be characterized in that it is provided with ku.

With the above structure, it is possible to obtain a magnetic head having high heat resistance and high sensitivity and high output.

A magnetic memory according to the present invention includes the magnetoresistive effect element described above, an information recording conductor line for recording information on the magnetoresistive effect element, and an information reading conductor line for reading the information. It is characterized by having and.

With the above structure, a high-density magnetic memory having excellent heat resistance can be obtained.

[0015]

First, an MR element according to the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view showing an example of an MR element according to the present invention.

In the example shown in FIG. 1, the antiferromagnetic layer 10, the pinned magnetic layer 20, the nonmagnetic layer 30, the free magnetic layer 40, and the Ni—Fe—X alloy layer 50 are sequentially laminated from the substrate 60 side. . In this element, a Ni-Fe-X alloy layer is arranged so as to be in contact with the surface of the multilayer film unit including the antiferromagnetic layer, the pinned magnetic layer, the nonmagnetic layer and the free magnetic layer opposite to the substrate.

In the element shown in FIG. 1, the antiferromagnetic layer 1
The exchange bias magnetic field from 0 causes magnetic field anisotropy in one direction in the pinned magnetic layer 20, and its magnetization direction does not easily rotate with respect to the external magnetic field. On the other hand, the magnetization direction of the free magnetic layer 40 is relatively easy to rotate, and it is a spin valve type MR element.

As will be described later, when the MR element shown in FIG. 1 is used as an actual device, electrodes and the like are further provided if necessary. In addition, the nonmagnetic layer 30 shown in FIG.
Is made of an insulating material (TMR), but may be a layer made of a conductive material (GMR).
The same applies to the examples shown in FIGS. 2 to 5 below.

The free magnetic layer 40 has excellent soft magnetic characteristics.
Is important, for example the formula Ni _pCo_qFe_rIndicated by
A metal A having a composition can be used. p, q and
And r are 0 ≦ p ≦ 1, 0 ≦ q ≦ 1, 0 ≦ r ≦ 1, p + q + r =
It is adjusted according to the required characteristics in the range of 1.

When the metal A is a ternary system (p ≠ 0, q ≠
0, r ≠ 0), 0.6 ≦ p ≦ 0.9, 0 <q ≦ 0.4, 0 <r ≦ 0.3, or 0 <p ≦ 0.4, 0.2 ≦ q ≦ 0.95, 0 <
The range of r ≦ 0.5 is preferable. Metal A is Ni
And a binary system of Fe (p ≠ 0, q = 0, r ≠ 0),
The range of 0.6 ≦ p <1 is preferable. When the metal A is a binary system of Co and Fe (p = 0, q ≠ 0, r
≠ 0), and the range of 0.7 ≦ q ≦ 0.95 is preferable.

Alternatively, amorphous magnetic materials such as Co-Fe-B, Co-Mn-B, and Fe-Co-Si mainly containing 3d transition metals can be used because they have excellent soft magnetic characteristics. Further, a plurality of magnetic materials can be laminated if necessary.

As the free magnetic layer 40, a magnetic film having the above composition can be used. Further, it may be a laminated film of a plurality of the above magnetic films. The free magnetic layer 40
Is preferably 1 × 10 ⁻⁵ or less, which is a low magnetostrictive characteristic value required for sensors and MR heads.

As the pinned magnetic layer 20, it is preferable to use a magnetic film containing a magnetic material having large magnetic anisotropy. Examples of magnetic materials having large magnetic anisotropy include Co and Co-Fe.
Alloy or the like, or a high coercive force magnetic material having a composition represented by the formula MD represented by Co-Pt alloy and Fe-Pt alloy (where M is at least one element selected from Fe, Co and Ni) And D is Pt, Rh, Pd, Ru, Cr, R
(At least one element selected from e, Ir and Ta), and other magnetic element-rare earth element alloys represented by Co-Sm alloys can be used. However, in the spin-valve MR element, since the magnetization direction of the pinned magnetic layer 20 can be fixed by the antiferromagnetic layer 10, the above-mentioned magnetic material having excellent soft magnetic characteristics can also be used.

The antiferromagnetic layer 10 is represented by the formula Z-Mn (where Z is at least one element selected from Pt, Ni, Pd, Cr, Rh, Re, Ir, Ru and Fe). It is preferable to include an Mn alloy having a certain composition. Among them, as Mn alloys, Pt-Mn, Pd-Mn, Pd-Pt-Mn, Ni-Mn, Ir-Mn, Cr-P
Particularly preferred are t-Mn, Ru-Rh-Mn, Fe-Mn and the like. The exchange coupling energy that acts between the Mn alloy and the ferromagnetic material is larger than that when using other antiferromagnetic materials (NiO, CrAl, α-Fe ₂ O _3, etc.), and even under a small magnetic field, A stable MR element with a larger output can be obtained.

The nonmagnetic layer 30 may be made of either a conductive material or an insulating material (it can be used as both a GMR element and a TMR element).
As the conductive material, a material containing at least one element selected from Cu, Ag, Au, Cr and Ru is preferable because a large MR ratio can be obtained. In this case, the thickness of the nonmagnetic layer 30 is preferably 1.5 nm or more and 5.0 nm or less. As the insulating material, Mg—O or the like may be used, but a material containing at least one compound selected from oxides, nitrides and oxynitrides of Al, which has excellent insulating properties, is preferable. By using the above insulating material, a tunnel current flows in the nonmagnetic layer 30 and the TMR effect can be obtained. In this case, in order to obtain an effective TMR effect, the thickness of the nonmagnetic layer 30 is 0.4n.
It is preferably m or more and 5.0 nm or less.

As shown in FIG. 1, Ni is formed on the free magnetic layer 40.
-By stacking the Fe-X alloy layer 50, the stress and magnetostriction acting on the free magnetic layer 40 are suppressed, the coercive force and anisotropic magnetic field of the free magnetic layer 40 are suppressed from increasing, and the MR output is improved. For this reason, it is possible to suppress deterioration of the soft magnetic characteristics due to thinning. In addition, the Ni-Fe-X alloy layer 50 is
It also has a role as a protective layer of the free magnetic layer 40, and also has a function of restricting impurity diffusion and interface diffusion due to a high temperature heat treatment process and temperature rise during operation, and suppressing deterioration of the soft magnetic characteristics of the free magnetic layer 40. is there.

The Ni-Fe-X alloy layer 50 has the formula Ni _a Fe _(1-ab) X _b
It is preferable to have a composition represented by However, a and b are numerical values that satisfy 0.4 <a <1, 0 <b <0.5, and a + b <1.

Among them, a and b are 0.5 ≦ a ≦ 0.9,
It is preferable that the numerical value satisfies 0.05 ≦ b ≦ 0.4. At this time, the Ni-Fe-X alloy layer 50 is an alloy containing Ni as a main component (here, the main component means a component showing an atomic composition ratio of 0.5 or more), and the above effect can be obtained even at higher temperatures. It can be stably obtained.

By adjusting the amount of addition of X, Ni-Fe
It is also possible to make the amount of saturation magnetization of the -X alloy layer 50 sufficiently smaller than that of the free magnetic layer 40 to make it substantially non-magnetic.

When at least one element selected from Cr, V and Nb is used as X, the specific resistance of the Ni-Fe-X alloy can be about 30 μΩcm or more. At this time, the resistance of the Ni-Fe-X alloy layer 50 can be made larger than that of the free magnetic layer 40, and even in the GMR element in which the nonmagnetic layer 30 is made of a conductive material such as Cu, it contributes to the magnetic resistance. Since the current shunt to the Ni-Fe-X alloy layer 50 which is not performed is suppressed, a larger MR ratio can be obtained.

As shown in FIG. 1, the film thickness of the Ni-Fe-X alloy layer 50 when laminated on the unit surface opposite to the substrate is 0.5.
nm to 10 nm is preferable. If the thickness is less than this range, the Ni-Fe-X alloy layer may not be a continuous film and the above effect may not be obtained. On the contrary, if the thickness is thicker, the TMR element is not particularly limited. Element, especially CIP-
In the GMR element, the obtained MR effect may be reduced.

On the Ni-Fe-X alloy layer 50, as a protective layer, T
a, Nb, Zr, a layer containing a high resistance metal such as W may be further arranged, or Pt, Pd which is a platinum group element excellent in corrosion resistance,
A layer containing Ru, Ir, Rh, Au, or the like can be arranged.

Further, in the example shown in FIG. 1, another layer may be added between the free magnetic layer 40 and the Ni—Fe—X alloy layer 50, if necessary. In this case, the layer from the antiferromagnetic layer to the added layer becomes a multilayer film unit.

FIG. 2 is a sectional view showing another example of the MR element according to the present invention.

In the example shown in FIG. 2, from the substrate 60 side, Ni-F
The eX alloy layer 50, the free magnetic layer 40, the nonmagnetic layer 30, the pinned magnetic layer 20, and the antiferromagnetic layer 10 are sequentially stacked. In this device, a Ni-F layer is provided between the substrate and the multilayer unit including the antiferromagnetic layer, the pinned magnetic layer, the nonmagnetic layer and the free magnetic layer.
An eX alloy layer is placed.

Also in the example shown in FIG. 2, the free magnetic layer 40 is used.
The Ni-Fe-X alloy layer 50 is laminated on the inner surface of the free magnetic layer 40. As with the example shown in FIG. 1, deterioration of the soft magnetic characteristics of the free magnetic layer 40 due to thinning can be suppressed.

Further, in the example shown in FIG. 2, since the Ni—Fe—X alloy layer 50 is arranged between the substrate and the multilayer film unit, the film structure and crystal orientation of the free magnetic layer 40 are controlled. It also has a function as a base layer. Ni-Fe-X alloy layer 50
Is generally face-centered cubic (fc
c) It becomes a crystal orientation film showing orientation. Therefore, if the Ni-Fe-X alloy layer is used as the underlayer, the main structure of the free magnetic layer 40 can be oriented in the fcc orientation from the initial film growth process stage. Here, the main structure is about the crystal structure of the alloy layer.
A structure that occupies 60 vol% or more. Since the free magnetic layer whose main structure has the fcc orientation has good soft magnetic characteristics, the free magnetic layer 40 can be thinned. Therefore, by stacking the Ni—Fe—X alloy films 50 as described above, it is possible to obtain a heat-resistant MR element with improved output.

In the MR element shown in FIG. 2, Ni-Fe-
The X alloy layer 50 may affect not only the free magnetic layer 40 but also the crystal structure of the nonmagnetic layer 30 as an underlayer. In particular, in the case of a TMR element using an insulating material for the non-magnetic layer 30, it is considered that the film quality of the non-magnetic layer is improved, for example, the crystallinity of Al ₂ O ₃ or the like used as the non-magnetic material is improved. A stable MR element having a large ratio can be obtained.

The film thickness of the Ni—Fe—X alloy layer 50 when it is arranged between the substrate and the multilayer film unit may be at least 1 nm or more. When the Ni-Fe-X alloy layer has a thickness of 1 nm or more
Since the fcc orientation is exhibited, the crystal orientation of the free magnetic layer 40 formed on this layer also becomes good from the initial state, and a free magnetic layer having excellent soft magnetic characteristics can be obtained.

Further, as in the example shown in FIG. 1, Ni-Fe-X
At least 1 selected from Cr, V and Nb as X of the alloy
When a seed element is used, a large MR ratio can be obtained even in a GMR element in which the nonmagnetic layer is a conductive material such as Cu.

A layer containing high resistance Ta, Nb, Zr, W, etc. may be further laminated between the Ni—Fe—X alloy layer 50 and the substrate 60 as a base layer, and may be corrosion resistant. It is also possible to stack layers containing Pt, Pd, Ru, Ir, Rh, Au and the like, which are excellent platinum group elements.

Further, in the example shown in FIG. 2, another layer may be arranged between the free magnetic layer 40 and the Ni—Fe—X alloy layer 50, if necessary. In this case, the layer from the arranged layer to the antiferromagnetic layer becomes a multilayer film unit. In addition,
The layer to be arranged is preferably made of a material that easily causes fcc orientation.

FIG. 3 is a sectional view showing another example of the MR element according to the present invention.

In the example shown in FIG. 3, from the substrate 60 side, Ni-F
The eX alloy layer 50, the antiferromagnetic layer 10, the pinned magnetic layer 20, the nonmagnetic layer 30, and the free magnetic layer 40 are sequentially stacked. In this element, a Ni-Fe- layer is formed between the substrate and the multilayer unit including the antiferromagnetic layer, the pinned magnetic layer, the nonmagnetic layer and the free magnetic layer.
X alloy layers are laminated.

The antiferromagnetic property of the antiferromagnetic layer is generally greatly affected by the crystallinity of the underlying layer. Therefore, FIG.
As shown in FIG. 3, Ni-Fe-X is used as a base layer of the antiferromagnetic layer 10.
When the alloy layer 50 is laminated, the Ni-Fe-X alloy is 1 as described above.
Since it becomes a good fcc alignment film at a film thickness of nm or more,
It is possible to obtain excellent antiferromagnetic properties by orienting the antiferromagnetic layer 10 in the fcc orientation. That is, the anti-ferromagnetic layer 10 having a large exchange bias magnetic field with respect to the pinned magnetic layer 20 and thermally stable can be obtained, and an MR element having excellent heat resistance can be obtained.

Further, in each of the pinned magnetic layer 20, the non-magnetic layer 30, and the free magnetic layer 40, a material that easily causes fcc orientation (for example, a pinned magnetic layer is a Co—Fe alloy or the like, a free magnetic layer is a Co—Fe alloy). Alloy or Ni-Fe alloy)
The pinned magnetic layer 20 and the free magnetic layer 40 having the fcc orientation can be obtained. Since the fcc-oriented free magnetic layer has excellent soft magnetic characteristics, it is expected that the free magnetic layer can be thinned to improve the MR output.

Further, similarly to the example shown in FIG. 2, the nonmagnetic layer 3
In the case of a TMR element using an insulating material as 0, the crystal quality of Al ₂ O ₃ used as a non-magnetic material is improved and the film quality of the non-magnetic layer is improved. It is possible to obtain an MR element having excellent mechanical stability.

Further, in the example shown in FIG. 3, another layer may be added between the antiferromagnetic layer 10 and the Ni—Fe—X alloy layer 50, if necessary. In this case, the layer from the added layer to the free magnetic layer becomes a multilayer film unit. In addition,
As the layer to be added, a material that easily causes fcc orientation is preferable.

FIG. 4 is a sectional view showing another example of the MR element according to the present invention.

In the example shown in FIG. 4, from the substrate 60 side, Ni-F
eX alloy layer 50a, antiferromagnetic layer 10, pinned magnetic layer 20,
Non-magnetic layer 30, free magnetic layer 40, Ni-Fe-X alloy layer 50b
Are sequentially stacked. In this element, Ni-Fe-X alloy layers are laminated on both surfaces of a multilayer film unit including an antiferromagnetic layer, a pinned magnetic layer, a nonmagnetic layer and a free magnetic layer.

In the example shown in FIG. 4, the Ni-Fe-X alloy layer 5
Reference numeral 0a is a base layer of the antiferromagnetic layer 10, and as with the example shown in FIG. 3, the antiferromagnetic layer 1 having excellent antiferromagnetic properties.
The free magnetic layer 40 exhibiting 0 and excellent soft magnetic characteristics can be obtained. Further, in this example, the Ni-Fe-X alloy layer 50
Since b is stacked on the free magnetic layer 40, deterioration of the soft magnetic characteristics of the free magnetic layer 40 due to stress or magnetostriction generated at the interface with the nonmagnetic layer 30 can be suppressed. At this time, Ni
As the protective layer, the -Fe-X alloy layer 50b also has an effect of preventing the soft magnetic characteristics of the free magnetic layer 40 from deteriorating due to interface diffusion or impurity diffusion caused by heat treatment at high temperature or increase in operating temperature. .

The film thickness of the Ni-Fe-X alloy layer 50a which is the underlayer is preferably 1 nm or more. In addition, the Ni-Fe-X alloy layer 50b
The film thickness of is preferably in the range of 0.5 nm to 10 nm.

In the example shown in FIG. 4, similar to the examples up to now, a high-resistance material containing Ta, Nb, Zr, W, etc. as an underlayer between the Ni—Fe—X alloy layer 50a and the substrate. Additional layers may be added, and Pt and P which are platinum group elements with excellent corrosion resistance
A layer containing d, Ru, Ir, Rh, Au or the like may be added. Ni-Fe-X alloy layer 50b laminated on the free magnetic layer 40
Similar layers can be added on top.

In the MR element of the present invention, in order to obtain a larger and stable MR effect, a laminated ferri pinned magnetic layer 21 as shown in FIG. 5 can be used instead of the pinned magnetic layer. This will be described below with reference to FIG.

The laminated ferrimagnetic pinned magnetic layer 21 is composed of the non-magnetic film 2
It is a pinned magnetic layer including a laminated film in which two magnetic films (the first magnetic film 211 and the second magnetic film 213) are laminated with 12 in between. Both of the magnetic films are in an antiferromagnetic exchange coupling state via the non-magnetic film 212, and substantially the same effect can be obtained as when the exchange coupling magnetic field of the pinned magnetic layer is increased (the film thickness is increased). it can. Further, a plurality of non-magnetic films may be present as long as the magnetic films are in contact with both surfaces thereof.

As the non-magnetic film 212, Ru, Ir, Rh, Re
A film containing at least one element selected from Cr and Cr is preferable, and its film thickness is preferably 0.4 to 1.5 nm.

Further, as the first magnetic film 211 and the second magnetic film 213 that sandwich the non-magnetic film 212, Co and Co-F are used.
Co-based alloys such as e, Co-Pt, and Co-Cr-Pt are preferable.

In the MR element of the present invention,
In order to obtain a larger MR ratio, a high spin polarizability layer containing a magnetic material having a high spin polarizability in at least one of the interfaces between the free magnetic layer or the pinned magnetic layer (or the laminated ferri pinned magnetic layer) and the non-magnetic layer. Can be inserted.

As the magnetic material having a large spin polarizability, for example, Co--Fe alloy (Co atomic composition ratio is 0 to 0.9), Ni--Fe alloy (Ni atomic composition ratio is 0 to 0.65) and the formula ME are shown. Alloy material having the following composition (where M is Fe, Co and Ni)
At least one magnetic element selected from, E is Pt, Pd, I
At least one element selected from r, Ru and Rh, and the atomic composition ratio of M is 0.5 to 1) and the like can be used. Others, Fe ₃ O ₄ , CrO ₂ , LaSrMnO, LaCaSrMnO
Half metal materials such as NiMnS
Heusler alloys such as b and PtMnSb can be used.

As the high spin polarizability layer, a single layer film or a laminated film of the above magnetic material can be used. The film thickness of the high spin polarizability layer is preferably at least 0.5 nm or more. When used at the interface between the pinned magnetic layer (or the laminated ferrimagnetic pinned magnetic layer) and the non-magnetic layer, the upper limit of the film thickness is not particularly limited. When used at the interface between the free magnetic layer and the non-magnetic layer, if the soft magnetic characteristics are not better than those of the magnetic material used for the free magnetic layer, the film thickness is preferably 2 nm or less, and 1 nm or less. Is more preferable. The high spin polarizability layer is particularly effective for improving the MR ratio in the TMR element in which the nonmagnetic layer is made of an insulating material.

Further, as shown in FIG. 1 and FIGS.
In the MR element including the multilayer unit in which the antiferromagnetic layer is located on the substrate side, it is preferable to dispose the underlayer between the antiferromagnetic layer and the substrate. As shown in FIGS. 3 to 5, Ni-F
When the eX alloy layer is placed between the multilayer unit and the substrate, it may be placed between the Ni-Fe-X alloy layer and the antiferromagnetic layer or between the Ni-Fe-X alloy layer and the substrate. You can place it. The structure of the antiferromagnetic layer is controlled by the underlayer, and good exchange coupling can be generated between the antiferromagnetic layer and the pinned magnetic layer.

For example, as the antiferromagnetic layer, Ir-Mn, Rh-M
n, Ru-Mn and Rh-Ru-Mn when using an antiferromagnetic material having a main structure of fcc orientation, Ta, Nb, Ti, as the underlayer,
By using Hf and Zr, the antiferromagnetic layer exhibits better antiferromagnetic properties. Further, it is preferable to further provide a Ni—Fe buffer layer having an fcc orientation between the underlying layer and the antiferromagnetic layer. When Ni-Mn, Pt-Mn, Pd-Pt-Mn, etc. are used for the antiferromagnetic layer, the main structure of the above materials changes from fcc orientation to fct (face centered tetragonal) orientation during heat treatment. By doing so, an exchange coupling magnetic field is generated between the fixed magnetic layer. However, even in this case, since the main structure is fcc orientation during film formation, the T
Use of a, Nb, Ti, Hf, Zr and the like makes it possible to obtain better antiferromagnetic properties. Similarly, it is preferable to further provide a Ni-Fe buffer layer.

Next, a method of manufacturing the MR element according to the present invention will be described.

For forming each thin film constituting the MR element in the present invention, pulse laser deposition (PLD), ion beam deposition (IBD), cluster ion beam, and RF, DC, ECR, helicon, inductively coupled plasma are used. (ICP), various sputtering methods such as opposed targets, MBE, ion plating method, etc. can be applied. In addition to the PVD method, a CVD method, a plating method, a sol-gel method, or the like can be used.

When a nonmagnetic layer (tunnel insulating layer) made of an insulating material such as Al ₂ O ₃ , Al—N, Al—ON, or Mg—O is prepared, for example, a thin film precursor of Al or Mg. Make O
Alternatively, the thin film precursor may be reacted with O or N in an atmosphere containing N as molecules, ions, radicals, etc. while controlling the temperature and time. The thin film precursor can be almost completely oxidized or nitrided to obtain a tunnel insulating layer. Further, as the thin film precursor, a nonstoichiometric compound containing O or N in an amount less than the stoichiometric ratio may be prepared.

For example, when Al ₂ O ₃ is formed as the tunnel insulating layer by using the sputtering method, Al or AlO _x
A film of (x ≦ 1.5) may be formed in an Ar or Ar + O ₂ atmosphere, and this may be oxidized in O ₂ or O ₂ + inert gas. ECR is used for plasma and radical production.
Normal means such as discharge, glow discharge, RF discharge, helicon, inductively coupled plasma (ICP) may be used.

A device using the MR element of the present invention will be described below.

In order to manufacture a magnetic device including an MR element for passing a current in the direction perpendicular to the film surface, a semiconductor process or GMR is used.
Combining photolithography techniques using physical or chemical etching methods such as ion milling, RIE, FIB, etc., which are generally used in the head manufacturing process, steppers for forming fine patterns, EB methods, etc. Fine processing is sufficient.

An example of an MR element manufactured by such a method is shown in FIG. In the device shown in FIG. 6, on the substrate 504,
A lower electrode 503, an MR element 505, and an upper electrode 502 are sequentially stacked, and an interlayer insulating film 501 is arranged between the electrodes around the MR element 505. The interlayer insulating film 501 has a function of preventing an electrical short circuit between the upper electrode 502 and the lower electrode 503. In this element, a current is passed through the MR element 505 sandwiched between the upper electrode 502 and the lower electrode 503 to read the voltage between the electrodes. With such an element structure, a current flows in the direction perpendicular to the film surface of the MR element 505,
The MR output can be read. Note that CMP, cluster ion beam etching, or the like can be used to planarize the surface of the electrode or the like.

The materials of the electrodes 502 and 503 are Pt and
A low resistance material having a resistivity of 100 μΩcm or less such as Au, Cu, Ru, Al or TiN may be used. As the interlayer insulating film 501, a material having an excellent insulating property such as Al ₂ O ₃ or SiO ₂ may be used.

FIG. 7 shows an example of a magnetic head using the MR element of the present invention. Note that FIG. 7 is a diagram in which a part of the magnetic head (for example, a part of the upper shield 512) is removed for easy understanding. In this magnetic head, the MR element 511 and the magnetic field other than the magnetic field to be detected are M
It is provided with two magnetic shields (upper shield 512 and lower shield 513) made of a magnetic material that restrict introduction into the R element. In addition, this magnetic head has an upper recording core 514, a coil 515, and a lead portion 5.
16, shield gap 517, hard bias portion 51
Eight and so on.

FIG. 8 is a sectional view of the vicinity of the MR element 511 of the magnetic head shown in FIG. 7, as seen from the direction of arrow A.
FIG. 8 is a schematic view using a cross section cut along a plane indicated by a dotted line B in FIG. 7. First, the structure around the MR element will be described with reference to FIG.

As shown in FIG. 8, the MR element 521 comprises an upper shield gap 522 and a lower shield gap 52.
It is arranged between 3 and 3. As a material for the shield gap, for example, an insulating film such as Al ₂ O ₃ , AlN and SiO ₂ may be used.

Outside the upper shield gap 522 and the lower shield gap 523, an upper shield 524 and a lower shield 525 are provided, respectively. As the material of the shield, for example, Ni-Fe alloy, F
Soft magnetic materials such as e-Al-Si alloys and Co-Nb-Zr alloys can be used.

In order to control the magnetization direction of the free magnetic layer of the MR element 521, the hard bias unit 526 is used to control the magnetization direction.
A bias magnetic field may be applied to the R element 521. A Co—Pt alloy or the like can be used as the material of the hard bias portion. Note that instead of the hard bias unit 526,
An antiferromagnetic material such as Fe-Mn can also be used.

The MR element 521 has a shield gap 52.
It is insulated from the shields 524 and 525 by 2 and 523, and the resistance change of the MR element 521 can be read by passing a current through the lead portion 527.

In an actual magnetic head, the portion shown in FIG. 8 is a reproducing head portion, and usually a recording head portion is further arranged. FIG. 10 shows an example of a magnetic head in which a recording head unit is further arranged. As shown in FIG. 10, the reproducing head unit 5
The recording head unit 552 may be further arranged on the 51.
The recording head unit 552 includes an upper recording core 554 and an upper shield 556, and a gap between the two serves as a recording gap 553.

Although the magnetic head structure based on the abutted junction is shown in FIGS. 8 and 10, the track width 528 and 555 can be further reduced to an overlaid structure. It may be a magnetic head structure based on the above.

Next, the recording / reproducing mechanism of the magnetic head according to the present invention will be described with reference to FIG. When recording information, a current may be passed through the coil 532 of the recording head unit 531. The magnetic flux generated by passing the current leaks from the recording gap 535 between the upper recording core 533 and the upper shield 534 and can be recorded in the recording magnetized portion 537 of the magnetic recording medium 536. In reproduction, the magnetic flux 538 leaked from the recording magnetizing unit 537 causes the upper shield 534 and the lower shield 540 of the reproducing head unit 539.
This is performed by acting on the MR element 542 through the reproduction gap 541 between them and changing the resistance of the MR element.

Another example of the magnetic head using the MR element of the present invention is shown in FIG. In the example shown in FIG. 11, a yoke (upper yoke 563 and lower yoke 564) for guiding the signal magnetic field to be detected to the MR element 561 and an insulating layer portion 562 are provided. The upper yoke 563 and the lower yoke 564 are generally made of a soft magnetic material. The signal magnetic field from the recording medium is transferred to the upper yoke 5
It is guided to the MR element 561 by 63. Upper yoke 56
3 has a gap 565, and the MR element 561 has
MR element 561, upper yoke 563 and lower yoke 5
It may be arranged between the gap 565 and the lower yoke 564 so that 64 is magnetically connected.

In the example shown in FIG. 11, the upper yoke 563,
A magnetic circuit is formed by the MR element 561 and the lower yoke 564, and the signal magnetic field from the recording medium detected by the reproducing gap 566 can be detected by the MR element 561 as an electric signal. The reproduction gap 56
The length of 6 (reproduction gap length) is preferably 0.2 μm or less.

MR element 561 of the magnetic head shown in FIG.
12 and 13 are cross-sectional views of a cut surface of the portion including the line taken along the dotted line I-I '. MR element 5 shown in FIG.
An example of the structure around 61 will be described in more detail with reference to FIGS. 12 and 13. FIG. 12 shows an example of using a CIP-GMR element, and FIG. 13 shows CPP-GMR or T
This is an example of using an MR element.

In the example shown in FIG. 12, the lead portion 567 is arranged so that the current flows in parallel to the film surface of the MR element 561. In the example shown in FIG. 13, the current is perpendicular to the film surface of the MR element 561. The lead portion 567 is arranged so that the current flows. In the example shown in FIG. 13, the lead portion 567 is the insulating layer portion 5.
Although it is electrically insulated from the yoke by 62, the lead portion and the yoke may be electrically connected.
In that case, the yoke and the lead portion can be combined.

In each example, the MR element 5
A hard bias portion 568 for controlling the magnetization direction of the free magnetic layer 61 is further arranged. In the example shown in FIG. 12, the hard bias section 568 is preferably arranged so as to be in contact with the MR element 561. In the example shown in FIG. 13, when a TMR element is used as the MR element 561,
It is preferable that the hard bias portion 568 be electrically insulated from the MR element 561 in order to stably pass the tunnel current through the element.

As the material of the insulating layer portion 562, Al ₂ O ₃ and A are used.
1N and SiO ₂ can be used. Upper yoke 5
The material used for 63 and the lower yoke 564 is Fe.
-Si-Al, Ni-Fe, Ni-Fe-Co, Co-Nb-Zr, Co-Ta-Zr, Fe-Ta
Soft magnetic materials such as -N are preferred. It is also possible to use a laminated film of a film made of the soft magnetic material and a non-magnetic film made of Ta, Ru, Cu or the like. As a material for the hard bias portion 568, a Co—Pt alloy or the like can be used. The lead portion 567 is a material having a general low electric resistance,
Cu, Au, Pt or the like may be used. The lower yoke 56
As the substrate 4, a substrate made of a magnetic material (for example, a Mn-Zn ferrite substrate) can be used.

In the case of a magnetic head having a yoke as shown in FIG. 11, it is preferable that the free magnetic layer of the MR element 561 be arranged on the side of the upper yoke 563.

By using the MR element of the present invention in the above-mentioned yoke type magnetic head, a high output magnetic head excellent in heat resistance can be obtained.

Incidentally, such a yoke type magnetic head is
Generally, the sensitivity is inferior to that of the shield type magnetic head as shown in FIG. 7, but it is advantageous to narrow the gap because it is not necessary to dispose the MR element in the shield gap. Further, since the MR element is not exposed to the recording medium, the head is not damaged or worn due to contact between the recording medium and the magnetic head, which is excellent in reliability. Therefore, the yoke type magnetic head is
It can be said that it is particularly excellent when it is used for a streamer whose recording medium is a magnetic tape.

FIG. 14 shows an example of an MRAM using the MR element of the present invention as a memory element. MR element 601 is Cu
Are arranged in a matrix at intersections of bit (sense) lines 602 and word lines 603 made of Al or Al. The bit line corresponds to the information reproducing conductor line, and the word line corresponds to the information recording conductor line. A signal is recorded in the MR element 601 by the combined magnetic field generated when a signal current is passed through these lines. The signal is recorded in the element (MR element 601a in FIG. 14) arranged at the position where the lines in the on state intersect (two current coincidence method).

The operation of the MRAM will be further described with reference to FIGS. These figures show basic examples of write and read operations. Figure 15
In the MRAM shown in (1), a switch element 705 such as a FET is arranged for each element in order to read the magnetization state of the MR element 701 individually. This MRAM is CMOS
Suitable for fabrication on a substrate. In the MRAM shown in FIG. 15, the non-linear element 706 is arranged for each element. As the non-linear element 706, a varistor, a tunnel element, or the like, or the above-mentioned three-terminal switch element or the like can be used. A rectifying element may be used instead of the non-linear element. This MRAM can be formed on an inexpensive glass substrate by using a diode film forming process. In the MRAM shown in FIG. 17, the MR element 701 is directly arranged at the intersection of the word line 704 and the bit line 703 without using the switch element or the non-linear element shown in FIGS. In this MRAM, since a current flows through a plurality of elements during reading, it is preferable to limit the number of elements to 10,000 or less in terms of reading accuracy.

In the example shown in FIGS. 15 to 17, the bit line 7
Reference numeral 03 is also used as a sense line for reading a resistance change by passing a current through the element. However, the sense line and the bit line may be separately arranged in order to prevent malfunction and element destruction due to the bit current. In this case, the bit line is preferably arranged in parallel with the sense line while maintaining electrical insulation from the element. From the viewpoint of power consumption during writing, the distance between the word line, bit line and MR element is preferably 500 nm or less.

[0093]

EXAMPLES The present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples.

On the Si substrate with thermal oxide film (3 inch φ), the MR element having the film constitution described in each of the examples was prepared by using the magnetron sputtering method, and the MR characteristics were examined. As the MR characteristics of the element, the MR ratio, the coercive force H _{c of} the free magnetic layer, the anisotropic magnetic field H _k of the free magnetic layer and the exchange bias magnetic field H _ex of the fixed magnetic layer were obtained.

The MR characteristics were calculated by measuring the magnetic resistance of the device. Magnetoresistance was measured up to 4.0 in the same direction as the easy axis of magnetization of the pinned magnetic layer (the direction of the magnetic field applied during the heat treatment performed to generate the exchange coupling magnetic field between the antiferromagnetic layer and the pinned magnetic layer). An external magnetic field of × 10 ⁵ A / m was applied to the device to perform the direct current four-terminal method.

First, the MR ratio was calculated by the following equation (1), where R _{max is} the maximum resistance value and R _min is the minimum resistance value obtained by measuring the magnetic resistance.

MR ratio = {(R _max −R _min ) / R _min } × 100 (%) (1)

Next, a method of calculating the exchange bias magnetic field H _ex will be described with reference to FIG. FIG. 21A shows the MR
It is a schematic diagram which shows an example of a major curve (major loop) of an element. The major curve can be obtained by measuring the magnetic resistance of the device. In the major loop shown in FIG. 21A, the change in the MR ratio recorded when the externally applied magnetic field H is near the zero magnetic field corresponds to the magnetization rotation of the free magnetic layer. The value of the applied magnetic field H is shown in FIG.
The change in MR ratio recorded near H _ex shown in (a) corresponds to the magnetization rotation of the pinned magnetic layer exchange-coupled with the antiferromagnetic layer. A magnetic field corresponding to the magnetization rotation of the pinned magnetic layer is called an exchange bias magnetic field H _ex, and its magnitude is half the maximum value (M ₀ ) of the MR ratio of the element as shown in FIG. Is given by the applied magnetic field H. When the exchange bias magnetic field H _ex is large, the magnetization rotation of the pinned magnetic layer is hard to occur, and the stability of the element is further improved.

Next, a method of calculating the coercive force H _c and the anisotropic magnetic field H _k of the free magnetic layer will be described with reference to FIG. FIG. 21B is an example of a minor curve of the MR element, which is an enlarged view of a portion corresponding to the magnetization rotation of the free magnetic layer in the major curve shown in FIG. In the curve shown in FIG. 21A, it seems that the magnetization rotation of the free magnetic layer occurs at the same magnitude of the applied magnetic field regardless of whether the applied magnetic field H is increased or decreased.
However, in reality, since the element has a hysteresis with respect to the applied magnetic field, as shown in FIG. 21B, the free magnetic layer is magnetized depending on whether the applied magnetic field H is increased or decreased. The magnitude of the rotating applied magnetic field H is different. In each of the case where the applied magnetic field H is increased and the case where the applied magnetic field H is decreased, the applied magnetic field at which the MR ratio of the element is half the maximum value (M ₀ ) is H ₁ and H ₂ , and the magnetization rotation of the free magnetic layer of the element When the applied magnetic field to be completed is H ₃ and H ₄ , the coercive force H _c and the anisotropic magnetic field H _k can be _obtained by the following equations (2) and (3).

Coercive force H _c = | H ₁ −H ₂ | / 2 (A / m) (2) Anisotropic magnetic field H _k = | H ₃ −H ₄ | / 2 (A / m) (3)

(Example 1) Si substrate with thermal oxide film / Ta (3)
/ Cu (50) / Ta (3) / Pt-Mn (20) / Co-Fe (5) / Al-O
(1.0) / Co-Fe (1) / Ni-Fe (3) / Ni-Fe-Pt alloy layer (2)

Here, the numerical value in the parentheses indicates the film thickness. The unit is nm, and hereinafter, the film thickness is similarly displayed. However, the value of the film thickness of Al-O indicates the design film thickness value (total value) of Al before the oxidation treatment (the same applies below including the nitriding treatment of Al-N). Al-O is 0.3-0.7 nm for Al
After the film formation, the film was formed by repeating the oxidation for 1 minute in the oxygen-containing atmosphere of 200 Torr (26.3 kPa).

Ta (3) / Cu (50) on the substrate is a lower electrode, and Ta (3) between the lower electrode and the Pt-Mn layer is a base layer. The Pt-Mn layer is an antiferromagnetic layer and its composition is Pt _0.5.
It was Mn _0.5 . In addition, Co-Fe (1) / N, which is a free magnetic layer
The composition of each i-Fe (3) layer and Co-Fe (5), which is the pinned magnetic layer, were Co _0.75 Fe _0.25 and Ni _0.8 Fe _0.2 , respectively. Ni-F
The e-Pt alloy layer corresponds to the Ni-Fe-X alloy layer in the present invention.

The film formation of the above sample was 1 × 10^-8Torr (1.3
× 10^-6After evacuation to less than Pa), Ar gas is about 0.
The temperature is adjusted so that the atmosphere is 8 mTorr (about 0.1 Pa).
I went inside the room. At this time, 100 Oe (8.0 x
Ten³A / m) magnetic field is applied parallel to the sample surface
While forming a film. After that, the above sample Ni-Fe-Pt alloy
Ta (15) / Pt (5) was laminated on the layer. Ta (15) / P
t (5) is a protective layer, but also partly serves as the upper electrode
It Next, photolithography and ion milling
Is used to perform microfabrication into a mesa type as shown in FIG.
Al as insulating film₂O ₃After insulating the surroundings using
Open a through hole and place Cu (50) / Ta (3) on this
A partial electrode was formed to produce an MR element. Made MR element
280 ℃, 5kOe (4.0 × 10^FiveA / m) in a vacuum magnetic field
Hold for 1.5 hours and magnetically change Pt-Mn (20) / Co-Fe (5)
It has been given a tortoise.

Using the above method, as an example, Ni-Fe-
The composition of the Pt alloy layer is Ni _0.55 Fe _0.1 Pt _{0.3 5} and Ni _0.7 Fe _0.15
Two types of Pt _0.15 were prepared, and as a comparative example, an element in which no Ni—Fe—Pt alloy layer was laminated (all other layers were the same as those in the example) was prepared. In addition, in each of the examples and the comparative examples, a plurality of samples having different element sizes were prepared. The shape of each sample was square when viewed from the surface direction.

As the MR characteristics of each sample, the coercive force H _c (A / m) and MR ratio (%) of the free magnetic layer were examined.

FIG. 18 shows the dependence of the coercive force H _{c on} the element size. The length of one side of the MR element, d (μm), was used as the element size (the element area is d × d (μm ² )).

As shown in FIG. 18, in the two samples of the embodiment in which the Ni—Fe—Pt alloy layer was laminated on the free magnetic layer, the Ni—Fe—
As compared with the comparative example having no Pt alloy layer, the coercive force H _c of the free magnetic layer was smaller in the same element size. Ni-
It is possible that the Fe-Pt alloy layer suppressed the increase in coercive force due to interface stress and magnetostriction.

Generally, as the element size decreases, the coercive force of the free magnetic layer tends to increase. However, since the Ni-Fe-Pt alloy layer can suppress the coercive force, the present invention can reduce the element size. Can be smaller. That is, it is possible to reduce the coercive force even if the element size is reduced. For example, when the MR element of the present invention is used for the MRAM, the current value required for writing information can be reduced, so that the MRAM has a high value. It is also very effective in terms of density and low power consumption.

In this example, the MR of all samples was examined regardless of the element size and the presence or absence of the Ni-Fe-Pt alloy layer.
The ratio was almost the same as about 40%.

Next, the samples of the above Examples and Comparative Examples were subjected to heat treatment at 400 ° C. for 1 hour in a non-magnetic field, and the change in coercive force of the free magnetic layer due to the heat treatment was examined.
In the comparative example, the coercive force was doubled, whereas
It was found that the two samples of the examples showed almost no increase in coercive force and were excellent in heat resistance.

Other than the Ni-Fe-Pt alloy layer, the formula Ni
-Fe-X (where X is Cr, V, Nb, Pt, Pd, Rh, Ru, I
Similar effects could be obtained when an alloy layer represented by (at least one element selected from r, Cu and Au) is used. At this time, if the composition ratio of Ni-Fe-X is in the range of more than 0.4 and less than 1 as Ni and more than 0 and less than 0.5 as X (however, the total atomic composition ratio of Ni, X and Fe is 1), The increase in coercive force of the magnetic layer can be further suppressed, and in particular, it was particularly effective when Ni was 0.5 to 0.9 and X was 0.05 to 0.4.

(Example 2) Using the same method as in Example 1, an MR element having the following film structure was produced.

Si substrate with thermal oxide film / Ta (3) / Cu (50) / T
a (3) / Ni-Fe-X alloy layer (3) / Ni-Fe (1) / Co-Fe (1)
/ Al-N (0.7) / Co-Fe (3.5) / Ir-Mn (10)

Ta (3) / Cu (50) on the substrate is the lower electrode, and Ta (3) between the lower electrode and the Ni—Fe—X alloy layer is the underlayer. The Ir-Mn layer is an antiferromagnetic layer and has a composition of Ir _0.8.
It was Mn _0.2 . In addition, the free magnetic layer Ni-Fe (1) / C
The composition of each layer of o-Fe (1) and Co-Fe (3.5) as the pinned magnetic layer were Ni _0.8 Fe _0.2 and Co _0.7 Fe _0.3 , respectively.

The Al-N layer is formed by depositing 0.7 nm of Al and then forming Ar and N
It was produced by nitriding Al using ICP in a mixed gas of ₂ . On the Ir-Mn layer, Ta (15) / Pt (5) is laminated as a protective layer (also partially serving as the upper electrode), and Cu (50) / Ta (3) is used for the upper electrode. Element size 0.2 μm
An MR element of 0.4 μm was prepared.

The manufactured MR element was tested at 250 ° C. and 5 kOe (4.0
In a vacuum magnetic field of × 10 ⁵ A / m), the magnetic field was applied in the longitudinal direction of the device and held for 3 hours to produce Co-Fe (3.5) / Ir-Mn (1
0) was given magnetic anisotropy.

Using the above method, as an example, Ni-Fe-
Five kinds of samples with different composition of X alloy layer were prepared (Table 1: Samples a01 to a05 below), and as a comparative example, Ni-Fe layer which is a normal soft magnetic material instead of Ni-Fe-X alloy layer was prepared. Two kinds of samples were prepared (Samples a06 to a07 below). The coercive force H _c (A / m) of the free magnetic layer was examined for each sample.

Table 1 shows the composition of the Ni—Fe—X alloy layer of each sample and the measurement result of the coercive force H _c .

[0120]

[Table 1]

As shown in Table 1, comparative examples a06 and a07.
Comparing the results of, it can be seen that the coercive force of a07 is smaller. This is because the Ni _0.8 Fe _0.2 layer laminated in place of the Ni-Fe-X alloy layer in a06 plays a role as a free magnetic layer, so the free magnetic layer in a06 becomes substantially thicker,
It is considered that the demagnetizing field is larger than that of a07.

Examples (a01-a05) and Comparative Examples (a06, a07)
Comparing with, it can be seen that the coercive force H _c is reduced in all the samples of the examples in which the Ni—Fe—X alloy layers are laminated. The reason is that the Ni-Fe-X alloy layer causes the Ni-Fe
The saturation magnetic field of the layer is reduced, the demagnetizing field of the free magnetic layer is reduced, the magnetostriction at the interface between the Ni-Fe-X alloy layer and the Ni-Fe layer is reduced, and other Ni-Fe-X alloys It is possible that the layer functions as a buffer layer of the free magnetic layer.

(Example 3) Using the same method as in Example 1, an MR element having the following film structure was produced. Two samples were prepared as examples and two samples were prepared as comparative examples.

Example b01: Si substrate with thermal oxide film / Ta (3) / Cu (50) / Ta (3) / Ni-F
e-Pt alloy layer (2) / Pt-Mn (15) / Co-Fe (3) / Al-O (2.
0) / Ni-Fe (5) / Ta (15) / Pt (10) Example b02: Si substrate with thermal oxide film / Ta (3) / Cu (50) / Ta (3) / Ni-F
e-Pt alloy layer (2) / Pt-Mn (15) / Co-Fe (3) / Ru (0.
7) / Co-Fe (3) / Al-O (2.0) / Ni-Fe (5) / Ta (15) /
Pt (10) Comparative Example b03: Si substrate with thermal oxide film / Ta (3) / Cu (50) / Ta (3) / Pt-M
n (15) / Co-Fe (3) / Al-O (2.0) / Ni-Fe (5) / Ta (1
5) / Pt (10) Comparative Example b04: Si substrate with thermal oxide film / Ta (3) / Cu (50) / Ta (3) / Pt-M
n (15) / Co-Fe (3) / Ru (0.8) / Co-Fe (3) / Al-O
(2.0) / Ni-Fe (5) / Ta (15) / Pt (10)

Ta (3) / Cu on the substrate in each sample
(50) is a lower electrode, Ta (3) on the lower electrode is a base layer, and Ta (15) / Pt (10) farthest from the substrate is a protective layer. The Pt-Mn layer is an antiferromagnetic layer and has a composition of Pt.
It was _0.48 Mn _0.52 . The composition of Ni-Fe (5), which is the free magnetic layer, is Ni _0.8 Fe _0.2 , and Ni-Fe-P, which is the Ni-Fe-X alloy layer.
The composition of the t alloy layer was Ni _0.6 Fe _0.1 Pt _0.30 . Example b
Co-Fe (3) in 01 and Comparative Example b03 is a pinned magnetic layer.

The Al—O layer was formed by forming Al to a thickness of 2.0 nm and then performing plasma oxidation. Plasma oxidation is performed by Ar-O ₂ mixed gas (pressure 0.8mTo) with oxygen partial pressure adjusted to 75%.
rr) In an atmosphere, oxygen plasma was generated by applying 150 W of RF power to the one-turn coil. The oxidation time was 30 seconds.

The pinned magnetic layer in Example b02 and Comparative Example b04 was a laminated ferri pinned magnetic layer (Co-Fe
(3) / Ru (0.7) / Co-Fe (3) part).

As the upper electrode, Ta (3) / Cu (50) was used.
Using / Pt (50) / Ta (15), the element size of each sample is
It was set to 20 μm × 50 μm.

Heat treatment was performed on the manufactured MR element at 270 ° C. for 10 hours while applying a magnetic field of ⁵ kOe (4.0 × 10 ⁵ A / m) in the longitudinal direction of the element, and then the MR characteristics of each sample. Was determined by measuring the magnetic resistance.

Table 2 shows the measurement results of the MR ratio, the coercive force H _c of the free magnetic layer and the exchange bias magnetic field H _ex of the fixed magnetic layer, which are obtained by measuring the magnetic resistance of each sample.

[0131]

[Table 2]

As shown in Table 2, in the examples (b01, b02) in which Ni-Fe-Pt alloy layers were laminated, the coercive force (H
_It can be seen that _c ) is significantly reduced compared to the comparative examples (b03, b04). Also, the MR ratio is slightly increasing.

As a cause of such a reduction in coercive force, Ni-F
It is possible that the e-Pt alloy layer acted as an underlayer and affected the crystal structure of the Ni-Fe layer, which is the free magnetic layer. When the crystal structure and orientation of each layer of each of the above samples were examined by X-ray diffraction, no clear diffraction intensity was obtained in Comparative Examples (b03, b04), and each layer had a non-oriented polycrystalline structure. It was On the other hand, in the example (b01, b02), the ft (1
11) Orientation and strong diffraction peaks showing the fcc (111) orientation of the Co-Fe layer as the fixed magnetic layer were obtained. Further, a diffraction peak showing the fcc (111) orientation of the Ni—Fe layer, which is the free magnetic layer, was also obtained. From these facts, the examples (b01, b
It is considered that the decrease in the coercive force of the free magnetic layer of 02) is due to the improvement of the crystal orientation of each layer on the Ni-Fe-Pt layer by the Ni-Fe-Pt layer.

Furthermore, in each sample, when the Al layer before oxidation of the Al—O layer which is the tunnel insulating layer was subjected to X-ray diffraction measurement, the Al layers of the examples (b01, b02) were found to be good. In contrast to the fcc (111) orientation, comparative examples (b03, b0
The Al layer in 4) had a non-oriented polycrystalline structure. Al layer is fcc (1
If the orientation is 11), the crystalline state of the Al-O layer after oxidation becomes good, and the characteristics as a tunnel insulating layer may be improved.

Further, it can be seen that the exchange bias magnetic field H _ex of Example b02 in which the pinned magnetic layer has the laminated ferri structure is larger than the exchange bias magnetic field of Comparative Example b04 having the same laminated ferri pinned magnetic layer. . By Ni-Fe-Pt alloy layer,
The Co-Fe layer, which is the pinned magnetic layer, has a fcc orientation and is a non-magnetic film
It is possible that the antiferromagnetic exchange coupling force via Ru increased.

From the above results, by stacking the Ni-Fe-Pt alloy layers, the coercive force of the free magnetic layer is reduced, the sensitivity as an element is improved, and the antiferromagnetic property of the laminated ferri pinned magnetic layer is improved. It can be seen that the effect of increasing the exchange coupling force and improving the stability of the device output can be obtained at the same time.

Example 4 Using the same method as in Example 1, an MR element having the following film structure was produced.

Si substrate with thermal oxide film / Ta (3) / Ni-Fe-Cr alloy layer (4) / Pt-Mn (15) / Co-Fe (2) / Ru (0.7) / Co-Fe
(3) / Cu (2.5) / Co-Fe (1) / Ni-Fe (5) / Ni-Fe-Cr
Alloy layer (t ₁ ) / Ta (3)

As described above, in this embodiment, between the Pt-Mn layer which is the antiferromagnetic layer and the substrate, and C which is the free magnetic layer.
A Ni-Fe-Cr alloy layer, which is a Ni-Fe-X alloy layer, was arranged both on the o-Fe (1) / Ni-Fe (5).

The pinned magnetic layer is made of Co--Fe (2) / Ru (0.
7) / Co-Fe (3) laminated ferri structure.

The composition of the free magnetic layer was Co _0.9 F, respectively.
The values were e _0.1 and Ni _0.8 Fe _0.2 . In addition, Pt-Mn layer and Ni-Fe
-Cr alloy layers are composed of Pt _0.48 Mn _0.52 and Ni _0.6 Fe, respectively.
It was _0.15 Cr _0.25 . The Ta (3) layer farthest from the substrate is
It is a protective layer.

The element size in this embodiment is 5
mm × 5 mm.

The manufactured MR element was subjected to heat treatment in the same magnetic field as in Example 1 to impart magnetic anisotropy to the antiferromagnetic layer / fixed magnetic layer. After heat treatment, at room temperature,
The magnetic resistance of the sample was measured by passing an electric current in parallel with the film surface of the device, and the MR ratio to the film thickness t ₁ of the Ni—Fe—Cr alloy layer formed on the free magnetic layer and the coercive force H of the free magnetic layer were measured. The change in _c was investigated. The measurement magnetic field in the magnetoresistance measurement was in the direction of the easy axis of magnetization of the pinned magnetic layer, that is, the same direction as the magnetization direction applied during the heat treatment for generating an exchange coupling magnetic field between the antiferromagnetic layer and the pinned magnetic layer. The measurement results are shown in FIGS. 19 (a) and 19 (b). In FIG. 19, “Ni-Fe-Cr
The film thickness t ₁ = 0 of the alloy layer means that the Ni—Fe—Cr alloy layer is not laminated.

As shown in FIG. 19B, the coercive force of the free magnetic layer is set to 80 A / m or less by arranging the Ni—Fe—Cr alloy layer having a thickness of 0.5 nm or more on the free magnetic layer. It turns out that it can be made very small. It is possible that the Ni-Fe-Cr alloy layer suppresses the increase in coercive force of the free magnetic layer caused by interface stress, magnetostriction, and lattice distortion.

Further, as shown in FIG. 19A, the MR ratio of the element was almost constant without decreasing even when the Ni—Fe—Cr alloy layers were laminated. This is because the resistivity of Ni-Fe-Cr alloy is
It is considered that the high resistance of 100 μΩcm or more causes almost no current shunt loss that does not contribute to the MR effect to the Ni—Fe—Cr alloy layer.

(Example 5) Using the same method as in Example 1, an MR element having the following film structure was produced.

Si substrate with thermal oxide film / Ta (3) / Ni-Fe-Cr alloy layer (4) / Pt-Mn (15) / Co-Fe (2.5) / Ru (0.7) / Co-
Fe (2.5) / Cu (2.3 ) / Co-Fe (1) / Ni-Fe (t 2) / Ni
-Fe-Cr alloy layer (1) / Ta (3)

In this embodiment, the pinned magnetic layer is made of Co--Fe (2.5).
A laminated ferri structure of / Ru (0.7) / Co-Fe (2.5) was adopted.
Further, both between the Pt-Mn layer which is the antiferromagnetic layer and the substrate and on the Co-Fe (1) / Ni-Fe (t ₂ ) which is the free magnetic layer,
A Ni-Fe-Cr alloy layer, which is a Ni-Fe-X alloy layer, was laminated.

In this example, the relationship between the film thickness t ₂ of the free magnetic layer and the anisotropic magnetic field exhibited by the free magnetic layer when a Ni—Fe—Cr alloy layer was laminated on the free magnetic layer was investigated. It was

The composition of each free magnetic layer was Ni _0.8 F.
It was e _0.2 and Co _0.9 Fe _0.1 . In addition, Pt-Mn layer and Ni-Fe
-Cr alloy layer composition is Pt _0.48 Mn _0.52 and Ni _0.6 Fe _0.15 Cr
It was _0.25 . The Ta (3) layer furthest from the substrate is the protective layer.

The device size in this embodiment is 5
mm × 5 mm.

The MR element thus produced was subjected to the following heat treatment in a magnetic field. First, 5kOe (4.0 × 10 ⁵ A
/ M) with a magnetic field applied, from room temperature to 280 ° C approximately 1.5
The temperature was raised over time and the temperature was maintained at 280 ° C. for 5 hours to impart magnetic anisotropy to the antiferromagnetic layer / fixed magnetic layer. After that, the temperature was lowered to 200 ° C over about 1.5 hours, and when the temperature reached 200 ° C, the applied magnetic field was changed to 100 Oe (8.0 × 10 ³ A / m),
The sample was rotated 90 ° and held for 1 hour, and then cooled to room temperature to impart magnetic anisotropy to the free magnetic layer.
Thus, for each of the fixed magnetic layer and the free magnetic layer,
After imparting magnetic anisotropy perpendicular to each other, the magnetic resistance of each sample was measured at room temperature to obtain a free magnetic layer.
The MR ratio of the element with respect to the film thickness t ₂ of the Ni-Fe layer and the anisotropic magnetic field H _k of the free magnetic layer were obtained. The measured magnetic field of the magnetoresistance is
The voltage was applied in the direction perpendicular to the magnetization direction of the pinned magnetic layer, that is, the magnetization direction of the free magnetic layer.

20 (a) and 20 (b) show the measurement results. Note that FIG. 20 also shows, as a comparative example, the results of a sample in which a Ni—Fe—Cr alloy layer is not laminated (other film configurations are the same as those of this example).

As shown in FIG. 20B, in the comparative example having no Ni—Fe—Cr alloy layer, the anisotropic magnetic field H _{k of the} free magnetic layer was reduced as the film thickness t ₂ of the Ni—Fe layer was reduced. It can be seen that is increasing. On the other hand, in the embodiment in which the Ni—Fe—Cr alloy layer is laminated on the Ni—Fe layer, the anisotropic magnetic field H _{k of the} free magnetic layer is
Holds a substantially constant value regardless of the layer thickness of the Ni-Fe layer. It can be seen that the Ni-Fe-Cr alloy layer provides good soft magnetic characteristics even when the thickness of the free magnetic layer is reduced.

Further, as shown in FIG. 20 (a), Ni-Fe-
The MR ratio slightly increases as the film thickness t ₂ of the Ni-Fe layer decreases regardless of the presence or absence of the Cr alloy layer. However, when the film thickness of the Ni-Fe layer is 5 nm or less, the Ni-Fe-Cr alloy layer The example having the above ratio showed a higher MR ratio. Considering the effect of suppressing the increase of the anisotropic magnetic field, which is a problem when thinning the free magnetic layer, it can be seen that the stacking of Ni—Fe—Cr alloy layers is very effective.

(Example 6) Using the MR element manufactured in Example 5, a magnetic head having a yoke structure as shown in FIGS. 11 and 12 was manufactured. As the substrate of the magnetic head, an Mn-Zn ferrite substrate, which is a magnetic material, is used, and the lower yoke is also used. Al ₂ O ₃ was used for the insulating layer portion, and a CoNbZr-based amorphous alloy film that was a high magnetic permeability material was used for the upper yoke.

The MR element had the following film structure (Ta (3) and Ni—Fe—Cr alloy layer (4) were laminated in this order from the substrate side).

Example c01: Ta (3) / Ni-Fe-Cr alloy layer (4) / Pt-Mn (15) / Co-Fe
(2) / Ru (0.7) / Co-Fe (3) / Cu (2.5) / Co-Fe
(1) / Ni-Fe (3) / Ni-Fe-Cr alloy layer (1) / Ta (3)

As a comparative example, a magnetic head similar to that of Example c01 was manufactured by using the MR element having the film structure shown below.

Comparative Example c02: Ta (3) / Pt-Mn (15) / Co-Fe (2) / Ru (0.7) / Co-Fe
(3) / Cu (2.5) / Co-Fe (1) / Ni-Fe (3) / Ta (3)

The size of the MR element is 8 μm at the MR height 570 shown in FIG. 11 and 10 μm at the MR width 569 shown in FIG.
And

Further, by using the same method as in Example 5, magnetic anisotropy orthogonal to each other was given to each of the fixed magnetic layer and the free magnetic layer.

When incorporating the MR element into the magnetic head,
The magnetization direction of the free magnetic layer was arranged to be perpendicular to the direction of the signal magnetic field to be detected, and the magnetization direction of the fixed magnetic layer was arranged to be parallel to the direction of the signal magnetic field to be detected.
In addition, a Co-Pt film was added as a hard bias portion to make the free magnetic layer a single magnetic domain. Cr / A on the lead
A laminated film of u was used.

The reproducing output of the magnetic head thus prepared was measured using a drum tester. First, an MP tape was used as a recording medium, and information was recorded on the MP tape using an MIG head. Then, the prepared magnetic head was run on the MP tape, and the obtained reproduction output was measured. The reproduction output of the magnetic head including the MR element of Example c01 was 0.5 dB higher than the reproduction output of the magnetic head including the MR element of Comparative Example c02.

Further, in order to investigate the thermal stability of the magnetic head, a test was conducted by applying a current of 25 mA to the magnetic heads equipped with the MR elements of Example c01 and Comparative Example c02 for 1000 hours. When the reproduction output of the magnetic head before and after the test was examined using the above drum tester and MP tape, the output reduction of the magnetic head equipped with the element of Example c01 before and after the test was less than 2%. On the other hand, the magnetic head equipped with the element of Comparative Example c02 had a decrease in output of about 20%, and further had a large distortion in the reproduced output waveform. From this, it was found that the magnetic head provided with the MR element according to the present invention was also excellent in thermal stability.

(Embodiment 7) Using the MR element manufactured in Embodiment 1, the magnetic memory (MRA) shown in FIG. 17 is used.
M) was prepared.

The MRAM was manufactured as follows. First, a word line made of Cu was formed on a Si substrate having a thermal oxide film of 300 nm, an Al ₂ O ₃ insulating film was formed on the surface of the word line, and then a lower electrode made of Cu was formed. Here, the lower electrode surface was once smoothed by CMP, and then an MR element having the following film structure was laminated.

Example d01: Pt-Mn (20) / Co-Fe (5) / Al-O (1.0) / Co-Fe (1) /
Ni-Fe (3) / Ni-Fe-Pt alloy layer (2) Comparative example d02: Pt-Mn (20) / Co-Fe (5) / Al-O (1.0) / Co-Fe (1) /
Ni-Fe (3)

Next, in both the example and the comparative example, the same procedure as in example 1 was performed so that the Pt-Mn layer as the antiferromagnetic layer and the Co-Fe (5) as the pinned magnetic layer generate an exchange coupling magnetic field. Was heat-treated in the magnetic field for 5 hours. Then, as in Example 1, the MR element was formed by performing mesa processing or the like. Finally, a bit line was formed as an upper electrode to fabricate a single magnetic memory without a switching element as shown in FIG.

With respect to the manufactured magnetic memory, a current is applied to the word line and the bit line to generate a magnetic field, and the magnetization direction of the free magnetic layer (Co-Fe (1) / Ni-Fe (3)) of the MR element is changed. Information “0” was recorded by reversing. Next, a current in the opposite direction to the previous direction was applied to the word line and the bit line to generate a magnetic field, and the magnetization of the free magnetic layer was inverted to record information "1". After that, a bias current was applied to the MR element in each state to flow a sense current, and the difference between the element voltages in the information “0” and information “1” states was measured.
Similar output differences were obtained in both the example and the comparative example. Therefore, it was found that both the example and the comparative example function as a magnetic memory having the free magnetic layer as the information recording layer.

Next, the MR element was placed on a CMOS substrate to fabricate an integrated magnetic memory as shown in FIG. The element array has a total of 8 blocks, with a memory of 16 × 16 elements as one block. The MR element was arranged as follows. First, FETs as switch elements were arranged in a matrix on a CMOS substrate, and the surface was flattened by CMP, and then the MR elements of the above-mentioned Example d01 and Comparative Example d02 were arranged in a matrix corresponding to the FETs. Each element size was 0.1 μm × 0.2 μm. One element in each block was a dummy element for canceling wiring resistance, minimum element resistance, FET resistance and the like. Note that Cu was used for all the word lines and bit lines. After forming the magnetic memory, hydrogen sintering treatment was performed at 400 ° C.

With respect to the manufactured magnetic memory, the magnetic field of the free magnetic layer of 8 elements in each block was simultaneously reversed by the combined magnetic field of the word line and the bit line to record a signal. Next, the gates of the FETs were turned on one by one for each block, and a sense current was passed through the devices. At this time, the voltage generated on the bit line, the element and the FET in each block and the dummy voltage were compared by the comparator and the output of each element was read.

As a result, MR using the MR element of Example d01
In AM, a good element output was obtained as in the case of the single magnetic memory, but the MRA using the MR element of Comparative Example d02 was obtained.
In M, no element output was obtained. From this, the MR element of Comparative Example d02 has a 400% increase in the coercive force of the free magnetic layer as described in Example 1.
Although it cannot withstand the heat treatment at ℃, MR of Example d01
It can be seen that the element has sufficient heat resistance even with heat treatment at 400 ° C.

[0174]

As described above, according to the present invention,
At least one surface of the multilayer unit including the antiferromagnetic layer, the pinned magnetic layer, the nonmagnetic layer, and the free magnetic layer is Ni-Fe-X
By stacking the alloy layers, a magnetoresistive effect element having good soft magnetic characteristics, high sensitivity, and excellent heat resistance can be obtained. Further, by using the magnetoresistive effect element of the present invention, a magnetic head corresponding to a high recording density and a high speed / high density magnetic memory can be obtained.

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of a magnetoresistive effect element according to the present invention.

FIG. 2 is a sectional view showing an example of a magnetoresistive effect element according to the present invention.

FIG. 3 is a sectional view showing an example of a magnetoresistive effect element according to the present invention.

FIG. 4 is a sectional view showing an example of a magnetoresistive effect element according to the present invention.

FIG. 5 is a sectional view showing an example of a magnetoresistive effect element according to the present invention.

FIG. 6 is a sectional view showing an example of a magnetoresistive effect element according to the present invention in which electrodes are further arranged.

FIG. 7 is a schematic diagram showing an example of a magnetic head according to the present invention.

FIG. 8 is a sectional view showing a structural example of a magnetic head according to the present invention.

FIG. 9 is a schematic diagram showing an example of a recording / reproducing method of a magnetic head according to the present invention.

FIG. 10 is a sectional view showing a structural example of a magnetic head according to the present invention.

FIG. 11 is a sectional view showing an example of a magnetic head according to the present invention.

FIG. 12 is a sectional view showing a structural example of a magnetic head according to the present invention.

FIG. 13 is a sectional view showing a structural example of a magnetic head according to the present invention.

FIG. 14 is a schematic diagram showing an example of a magnetic memory according to the present invention.

FIG. 15 is a schematic diagram showing a basic example of the operation of the magnetic memory according to the present invention.

FIG. 16 is a schematic diagram showing a basic example of the operation of the magnetic memory according to the present invention.

FIG. 17 is a schematic diagram showing a basic example of the operation of the magnetic memory according to the present invention.

FIG. 18 is a graph showing the relationship between the element size and the coercive force of the magnetoresistive element according to the present invention, which is measured by an example.

FIG. 19 (a) is a diagram showing the relationship between the film thickness of the Ni—Fe—Cr alloy layer in the magnetoresistive element of the present invention and the MR ratio of the element, which is measured by an example, and (b). Is the Ni-Fe-Cr in the magnetoresistive element of the present invention measured by the example.
It is a figure which shows the relationship between the film thickness of an alloy layer, and the coercive force of a free magnetic layer.

FIG. 20 (a) is a graph showing the film thickness of the Ni—Fe layer in the magnetoresistive element of the present invention and the MR of the element measured by the example
It is a figure showing the relation with a ratio, (b) shows the relation between the film thickness of the Ni-Fe layer and the anisotropic magnetic field of the free magnetic layer in the magnetoresistive element of the present invention measured by the example. Is a figure

FIG. 21 is a schematic diagram for explaining a method for measuring an exchange bias magnetic field (H _ex ), an anisotropic magnetic field (H _k ) and a coercive force (H _c ).

[Explanation of symbols]

10 antiferromagnetic layer 20 pinned magnetic layer 30 nonmagnetic layer 40 free magnetic layers 50, 50a, 50b Ni-Fe-X alloy layers 60, 504 substrate 21 laminated ferri pinned magnetic layer 211 first magnetic film 212 nonmagnetic film 213 2 magnetic film 501 interlayer insulating film 502 upper electrode 503 lower electrode 505, 511, 521, 542, 561, 601, 6
01a, 701 MR element 512, 524, 534, 556 Upper shield 513, 525, 540 Lower shield 514, 533, 554 Upper recording core 515, 532 Coil 516, 527, 567 Lead portion 517 Shield gap 518, 526, 568 Hard bias Part 522 Upper shield gap 523 Lower shield gap 528, 555 Track width 531, 552 Recording head part 535, 553 Recording gap 536 Magnetic recording medium 537 Recording magnetizing part 538 Magnetic flux 539, 551 Reproducing head part 541, 566 Reproducing gap 562 Insulating layer part 563 Upper yoke 564 Lower yoke 565 Gap 569 MR width 570 MR height 602, 703 Bit line 603, 704 Word line 705 Switch element 706 Non-linear element

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H01L 27/105 H01L 27/10 447 (72) Inventor Nozomu Matsukawa 1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric Industrial Company (72) Inventor Akihiro Odagawa 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor Yoshio Kawashima 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. (72) Inventor Mitsuo Satomi 1006, Kadoma, Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. F term (reference) 5D034 AA03 BA02 BA03 BA04 BA05 CA04 CA08 5E049 AA01 AA04 AA07 AA09 AC00 AC05 BA12 CB02 DB12 FC03 GC01 5F083 FZ10 LA12 LA16 NA08

Claims (21)

[Claims] 1. An antiferromagnetic layer, a pinned magnetic layer magnetically coupled to the antiferromagnetic layer, a nonmagnetic layer, and a free magnetic layer in which the magnetization direction is relatively easy to rotate than the pinned magnetic layer. A magnetoresistive effect element including a structure in which a multi-layer film unit including a multi-layer unit is formed on a substrate, and the fixed magnetic layer and the free magnetic layer are stacked with the non-magnetic layer interposed therebetween. Ni-Fe-X on at least one side
A magnetoresistive effect element comprising a structure in which alloy layers are laminated. However, X is Cr, V, Nb, Pt, Pd, Rh, Ru,
At least one element selected from Ir, Cu and Au. 2. The magnetoresistive element according to claim 1, wherein the alloy layer has a composition represented by the formula Ni _a Fe _(1-ab) X _b . However, in the formula Ni _a Fe _(1-ab) X _b , a and b are numerical values that satisfy the following formulas. 0.4 <a <1 0 <b <0.5 a + b <1 3. The magnetoresistive effect element according to claim 1, wherein a is a numerical value satisfying 0.5 ≦ a ≦ 0.9. 4. The magnetoresistive effect element according to claim 1, wherein b is a numerical value satisfying 0.05 ≦ b ≦ 0.4. 5. The magnetoresistive effect element according to claim 1, wherein the alloy layer is arranged between the substrate and the multilayer film unit. 6. The alloy layer is laminated on the surface of the multi-layer film unit opposite to the substrate.
4. The magnetoresistive effect element according to any one of 4 above. 7. The magnetoresistive element according to claim 1, wherein alloy layers are laminated on both surfaces of the multilayer film unit. 8. The magnetoresistive effect element according to claim 1, wherein the free magnetic layer is located closer to the substrate than the fixed magnetic layer. 9. The magnetoresistive element according to claim 1, wherein the fixed magnetic layer is located closer to the substrate than the free magnetic layer. 10. The magnetoresistive effect element according to claim 1, wherein the non-magnetic layer is made of a conductive material. 11. The magnetoresistive effect element according to claim 1, wherein the nonmagnetic layer is made of an insulating material. 12. The magnetoresistive device according to claim 1, wherein the pinned magnetic layer includes a non-magnetic film and a pair of magnetic films sandwiching the non-magnetic film. Effect element. 13. The non-magnetic film is Ru, Ir, Rh, Re and Cr.
The magnetoresistive effect element according to claim 12, comprising at least one element selected from the group consisting of: 14. The magnetoresistive effect element according to claim 1, wherein the antiferromagnetic layer contains an Mn alloy. 15. The magnetoresistive element according to claim 14, wherein the Mn alloy has a composition represented by the formula Z-Mn. However, Z is Pt, Ni, Pd, Cr, Rh, Re, Ir, Ru
And at least one element selected from Fe. 16. The crystal structure of the alloy layer is a face-centered cubic (fc
c) Orientation is included as a main structure.
16. The magnetoresistive effect element according to any one of items 1 to 15. 17. The alloy layer has a thickness of 0.5 nm or more and 10 nm or more.
It is the following, The magnetoresistive element as described in any one of Claims 1-16. 18. The magnetoresistive element according to claim 17, wherein the alloy layer has a thickness of 1 nm or more. 19. A magnetoresistive effect element according to claim 1, and a magnetic shield for restricting introduction of a magnetic field other than a magnetic field to be detected by the magnetoresistive effect element into the element. A magnetic head comprising: 20. A magnetic device comprising: the magnetoresistive effect element according to claim 1; and a yoke for introducing a magnetic field to be detected into the magnetoresistive effect element. head. 21. The magnetoresistive effect element according to claim 1, an information recording conductor line for recording information on the magnetoresistive effect element, and information for reading the information. A magnetic memory comprising a read conductor wire.