JP3153739B2 - Magnetoresistive element and magnetic transducer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetoresistive element for reading out a magnetic field strength of a magnetic recording medium or the like as a signal, and in particular, a magnetoresistive element capable of reading a small magnetic field change as a large electric resistance change signal. and,
The present invention relates to a magnetic transducer such as a magnetoresistive head using the same.

[0002]

2. Description of the Related Art In recent years, the sensitivity of magnetic sensors has been increased and the density of magnetic recording has been increased.
It is called a sensor. ) And a magnetoresistive magnetic head (hereinafter referred to as an MR head) have been actively developed. Both the MR sensor and the MR head read an external magnetic field signal by a change in resistance of a read sensor unit using a magnetic material.However, in the MR sensor and the MR head, the relative speed with respect to the recording medium does not depend on the reproduction output. From, MR
The sensor has a feature that high sensitivity is obtained, and the MR head can obtain a high output even at the time of signal reading of high-density magnetic recording.

However, the conventional Ni _0.8 Fe
_0.2 M using a magnetic material such as (Permalloy) or NiCo
In the R sensor, the resistance change rate ΔR / R is at most 1 to 3%
As a material for a read MR head for ultra-high density recording of several GBPI or more, the sensitivity is insufficient.

Meanwhile, artificial lattices having a structure in which thin films having a thickness on the order of the atomic diameter of a metal are periodically laminated have attracted attention in recent years because they exhibit characteristics different from those of bulk metals. As one type of such an artificial lattice, there is a magnetic multilayer film in which a ferromagnetic metal thin film and a non-magnetic metal thin film are alternately laminated on a substrate. Films are known. Of these, the iron-chromium type (Fe / Cr) has a very low temperature (4.2
K) shows a magnetoresistance change of more than 40% (Physical Review Letters (Phys.
Rev. Lett) 61, 2472, 1988). However, in this artificial lattice magnetic multilayer film, the external magnetic field (operating magnetic field intensity) at which the maximum resistance change occurs is as large as tens of kOe to tens of kOe, and there is no practical use as it is. In addition, Co / Ag
And the like, but the operating magnetic field strength is too large.

[0005] Under such circumstances, a new structure called a spin valve film has been proposed. This is because two NiFe layers are formed via a non-magnetic layer,
It has a configuration in which an FeMn layer is arranged adjacent to the iFe layer. Here, since the FeMn layer and the adjacent NiFe layer are directly coupled by the exchange coupling force, the direction of the magnetic spin of the NiFe layer is fixed to a magnetic field strength of several tens to several hundreds Oe. The direction of the spin of one NiFe layer can be freely changed by an external magnetic field. As a result, NiF
A magnetoresistance change rate (MR change rate) of 2 to 5% is realized in a small magnetic field range of about the coercive force of the e layer. Others
The following documents have been published.

A. Physical Review B (Physical
Review B), 43 (1991) 1297 Si / Ta (50) / NiFe (60) / Cu (20)
/ NiFe (45) / FeMn (70) / Ta (50)
[() Indicates the film thickness of each layer (Å), the same applies hereinafter] states that the MR change rate sharply rises to 5.0% with an applied magnetic field of 10 Oe.

B. Journal of Magnetics
And Magnetic Materials (Journal of M
Agnetism and Magnetic Materials), 93 (1991) 101Si / Ta (50) / NiFe (60) / Cu (25)
/ NiFe (40) / FeMn (50) / Cu (50)
States that when the applied magnetic field is 0 to 15 Oe, the MR change rate sharply rises from 0 to 4.1%.

C. Physical Review B (Physical
Review B), 45 (1992) 806 From the results of the above a and b, changes in the MR characteristics when the temperature characteristics, the magnetic layer thickness and the type of the magnetic layer are Co, NiFeNi, and the like are further analyzed.

D. Japanese Journal of Applied Physics
Physics), 32 (1993) L1441 Describes the MR change rate when the above structures a and b are formed as a multilayer structure. The multilayer structure here is NiFe
(60) / Cu (25) / NiFe (40) / FeMn
The structure (50) is laminated with Cu interposed therebetween.

Further, the following gazettes have been disclosed.

E. JP-A-2-61572 (U.S. Pat. No. 4,949,039) states that a ferromagnetic thin film laminated via a non-magnetic intermediate layer exhibits a large MR effect by taking an antiparallel arrangement between the respective layers. . It also describes a structure in which an antiferromagnetic material is adjacent to one of the ferromagnetic layers.

F. JP-A-5-347013 describes a magnetic recording / reproducing apparatus using a spin valve film. In particular, it discloses a case where nickel oxide is used as the antiferromagnetic film.

In such a spin valve magnetic multilayer film,
MR compared to Fe / Cr, Co / Cu, Co / Ag, etc.
Although the rate of change is inferior, the MR curve changes sharply with an applied magnetic field of several tens of Oe or less, and 1 to 10 Gbit / inch ²
It is suitable as an MR head material at a higher recording density. However, the contents disclosed in these documents and publications merely show the basic operation of the spin valve film.

At present, Ni _0.8 Fe _0.2 (permalloy) is mainly used as an MR head material in actual ultra-high density magnetic recording. In this method, a change in a signal magnetic field from a magnetic recording medium is converted into a change in electric resistance by the anisotropic magnetoresistance effect. The MR change rate is only 1-3%. Further, in this case, the magnetoresistance change has a characteristic symmetric with respect to the increase / decrease of the magnetic field around the zero magnetic field.

As means for solving such characteristics, N
In the case of iFe or the like, a shunt layer having a small specific resistance such as Ti is provided to shift the operating point. In addition to the shunt layer, a soft film bias layer of a soft magnetic material having a large specific resistance such as CoZrMo or NiFeRh is provided and used by applying a bias magnetic field. However, the structure having such a bias layer complicates the process, makes it difficult to stabilize the characteristics, and increases the cost.
Further, since a gentle part of the MR change curve generated as a result of shifting the MR curve is used, the MR gradient in a unit magnetic field is as small as about 0.05% / Oe, which leads to a decrease in S / N and the like. It is insufficient as an MR head material at a recording density larger than 10 Gbit / inch ² .

Further, an MR head or the like has a complicated laminated structure, and requires heat treatment such as baking and curing of a resist material in steps such as patterning and flattening.
Some degree of heat resistance may be required. However, in the conventional artificial lattice magnetic multilayer film, such heat treatment deteriorates the characteristics.

In the conventional spin valve film disclosed in the literature and the like, only the basic structure and basic characteristics of the thin film are discussed, and an MR head structure for realizing ultra-high density magnetic recording and an MR head structure suitable therefor are discussed. No mention was made of the magnetic multilayer structure.

As described above, in the examples shown in these documents, when those thin films are actually applied as an MR head, the MR gradient in the actual magnetic field detection range is small, and
Good and stable reproduction cannot be performed as the R head. In addition, as a material for an MR head in superior ultra-high density magnetic recording, an MR change curve from an applied magnetic field of -10 to 10 Oe is also important. However, none of the examples disclosed in these documents discuss the MR gradient in this range in detail.

Further, the MR head is required to be used under a high frequency magnetic field of 1 MHz or more for high density recording and reproduction. However, in the conventional film thickness structure of various ternary magnetic multilayer films, 10 Oe in a high-frequency magnetic field of 1 MHz or more is used.
Slope of magnetoresistance change curve with width (MR slope at high frequency)
Is not less than 0.2% / Oe, it is difficult to obtain high high-frequency sensitivity.

[0020]

SUMMARY OF THE INVENTION The present invention has been made in view of such a situation, and has as its object to show a large MR change rate and to apply an applied magnetic field of, for example, -10 to 10 Oe.
In a very small range, it shows linear rising characteristics of MR change, high magnetic field sensitivity, and high
An object of the present invention is to provide a magnetoresistive element including a magnetic multilayer film having a large inclination and a high heat resistance temperature, and a magnetic transducer such as a magnetoresistive head using the same.

[0021]

In order to solve such a problem, the present invention provides a magnetoresistive element, a conductive film,
A magnetic conversion element including an electrode portion, wherein the conductive film is
The magnetoresistance effect element is electrically connected to the magnetoresistance effect element through the electrode portion, and the magnetoresistance effect element includes a nonmagnetic metal layer, a ferromagnetic layer formed on one surface of the nonmagnetic metal layer, and a nonmagnetic metal layer. A magnetic multilayer film having a soft magnetic layer formed on the other surface of the layer and a pinned layer formed on the ferromagnetic layer to pin the direction of magnetization of the ferromagnetic layer. The ferromagnetic layer and the pinning layer are configured to be joined by epitaxial growth.

In a preferred aspect of the present invention, the pinning layer includes an antiferromagnetic layer, a hard magnetic layer, a pinning ferromagnetic layer made of a material different from a ferromagnetic layer connected to the pinning layer, and It is configured to be at least one selected from layers into which artificial structural defects have been introduced.

In a preferred embodiment of the present invention, the ferromagnetic layer is made of (Co _z Ni ₁ -z) _w Fe _{1 -w} (where 0.4 ≦ z ≦ 1.0, 0.5 ≦ w ≦ 1.0), and the soft magnetic layer is composed of (Ni _x Fe
_1-x ) _y Co _1-y (where 0.7 ≦ x ≦ 0.
9, 0.5 ≦ y ≦ 1.0).

In a preferred embodiment of the present invention, the ferromagnetic layer is made of (Co _z Ni ₁ -z) _w Fe _{1 -w} (where 0.4 ≦ z ≦ 1.0, 0.5 ≦ w ≦ 1.0 at a) in a composition represented, the soft magnetic layer, Co _t M _u M _'q
B _r (where, 0.6 ≦ t ≦ in atomic 0.95,0.01
≦ u ≦ 0.2, 0.01 ≦ q ≦ 0.1, 0.05 ≦ r ≦
0.3; M is at least one or more selected from Fe and Ni, and M 'is at least one or more selected from Zr, Si, Mo, and Nb). It is configured as follows.

As a preferred embodiment of the present invention, the nonmagnetic metal layer is made of a material containing at least one selected from Au, Ag, and Cu.

As a preferred embodiment of the present invention, the hard magnetic layer constituting the pinning layer is made of one kind of metal selected from Fe, Co and Ni, or is composed of Fe, C
50 wt% of one metal selected from o and Ni
It is comprised so that it may consist of an alloy containing the above.

In a preferred aspect of the present invention, the antiferromagnetic layer constituting the pinning layer is made of Fe, Ni, Co, Cr,
It is configured to be made of a material containing at least two or more selected from Mn, Ru, Rh, Mo, and O.

In a preferred embodiment of the present invention, the thickness of the ferromagnetic layer and the thickness of the soft magnetic layer are each 20 to 100.
構成 さ れ る.

In a preferred aspect of the present invention, the thickness of the ferromagnetic layer is 20 to 60 °, and the thickness of the soft magnetic layer is 40 °.
Å100 °.

In a preferred embodiment of the present invention, the thickness of the nonmagnetic metal layer is set to be 20 to 60 °.

In a preferred aspect of the present invention, the pinning layer is configured to have a thickness of 50 to 700 °.

As a preferred embodiment of the present invention, when the specific resistance of the pinned layer is ρ _p , the specific resistance of the ferromagnetic layer is ρ _f , and the specific resistance of the soft magnetic layer is ρ _s , The resistance relationship is configured to satisfy the following expression (1).

3 ((ρ _f + ρ _s ) / 2) <ρ _p <30 ((ρ _f + ρ _s ) / 2) Formula (1) As a preferred embodiment of the present invention, the magnetoresistive element includes:
The configuration is such that the slope of the magnetoresistance change in a 6 Oe width in a high-frequency magnetic field at 1 MHz is 0.2% / Oe or more.

As a preferred embodiment of the present invention, the magnetic transducer is configured to be a magnetoresistive head.

In a preferred aspect of the present invention, both ends of the magnetoresistive element are joined so that the entire end thereof is in contact with the electrode.

As a preferred embodiment of the present invention, a soft magnetic layer for connection is further provided between electrode portions formed at both ends of the magnetoresistive effect element, and the soft magnetic layer for connection is connected to the magnetoresistive effect element. It is configured such that the whole end of the element is connected in a state of contact.

In a preferred aspect of the present invention, the connection soft magnetic layer is provided between the magnetoresistive element and the electrode portions formed at both ends of the magnetoresistive element, and on the lower surface of the electrode portion. Are also formed so as to be continuously in contact with each other.

According to a preferred embodiment of the present invention, the magnetic transducer is configured so as not to have a bias magnetic field applying mechanism.

According to a preferred aspect of the present invention, the ferromagnetic layer is formed by applying an external magnetic field of 10 to 300 Oe in the same direction as the signal magnetic field and in the in-plane direction at the time of film formation. The soft magnetic layer is formed by applying an external magnetic field of 10 to 300 Oe in the direction perpendicular to the signal magnetic field direction and in the in-plane direction at the time of film formation. Further, the present invention is a magneto-resistance effect element, a conductor film, and a magnetic transducer including an electrode portion, wherein the conductor film is electrically connected to the magneto-resistance effect element through the electrode portion, The magnetoresistive element has a pinning layer for pinning the direction of magnetization of an adjacent ferromagnetic layer, and a pair of ferromagnetic layers, a pair of nonmagnetic metal layers, and a pair of layers on both sides of the pinning layer. A magnetic multilayer film having a magnetic multilayer film unit in which soft magnetic layers are sequentially arranged is provided, and the ferromagnetic layer and the pair of pinned layers are each configured to be joined by epitaxial growth.

In a preferred aspect of the present invention, the pinning layer includes an antiferromagnetic layer, a hard magnetic layer, a pinning ferromagnetic layer made of a material different from a ferromagnetic layer connected to the pinning layer, and It is configured to be at least one selected from layers into which artificial structural defects have been introduced.

In a preferred embodiment of the present invention, the ferromagnetic layer is made of (Co _z Ni ₁ -z) _w Fe _{1 -w} (where 0.4 ≦ z ≦ 1.0, 0.5 ≦ w ≦ 1.0), and the soft magnetic layer is composed of (Ni _x Fe
_1-x ) _y Co _1-y (where 0.7 ≦ x ≦ 0.
9, 0.5 ≦ y ≦ 1.0).

In a preferred embodiment of the present invention, the ferromagnetic layer is made of (Co _z Ni ₁ -z) _w Fe _{1 -w} (where 0.4 ≦ z ≦ 1.0, 0.5 ≦ w ≦ 1.0 at a) in a composition represented, the soft magnetic layer, Co _t M _u M _'q
B _r (where, 0.6 ≦ t ≦ in atomic 0.95,0.01
≦ u ≦ 0.2, 0.01 ≦ q ≦ 0.1, 0.05 ≦ r ≦
0.3; M is at least one or more selected from Fe and Ni, and M 'is at least one or more selected from Zr, Si, Mo, and Nb). It is configured as follows.

As a preferred embodiment of the present invention, the nonmagnetic metal layer is formed of a material containing at least one selected from Au, Ag, and Cu.

As a preferred embodiment of the present invention, the hard magnetic layer constituting the pinning layer is made of one kind of metal selected from Fe, Co and Ni, or is composed of Fe, C
50 wt% of one metal selected from o and Ni
It is comprised so that it may consist of an alloy containing the above.

In a preferred aspect of the present invention, the antiferromagnetic layer constituting the pinning layer is made of Fe, Ni, Co, Cr,
It is configured to be made of a material containing at least two or more selected from Mn, Ru, Rh, Mo, and O.

In a preferred aspect of the present invention, the thicknesses of the ferromagnetic layer and the soft magnetic layer are respectively 20 to 100.
構成 さ れ る.

In a preferred aspect of the present invention, the thickness of the ferromagnetic layer is 20 to 60 °, and the thickness of the soft magnetic layer is 40 °.
Å100 °.

According to a preferred aspect of the present invention, the thickness of the nonmagnetic metal layer is set to be 20 to 60 °.

In a preferred aspect of the present invention, the thickness of the pinning layer is set to be 50 to 700 °.

As a preferred embodiment of the present invention, when the specific resistance of the pinned layer is ρ _p , the specific resistance of the ferromagnetic layer is ρ _f , and the specific resistance of the soft magnetic layer is ρ _s , The resistance relationship is configured to satisfy the following expression (1).

3 ((ρ _f + ρ _s ) / 2) <ρ _p <30 ((ρ _f + ρ _s ) / 2) Equation (1) As a preferred embodiment of the present invention, the magnetoresistance effect element is
It is configured such that the gradient of the magnetoresistance change in a 6 Oe width in a high-frequency magnetic field at 1 MHz is 0.2% / Oe or more.

According to a preferred aspect of the present invention, the magnetic transducer is configured to be a magnetoresistive head.

In a preferred aspect of the present invention, both ends of the magnetoresistive element are joined so that the entire end thereof is in contact with the electrode.

As a preferred embodiment of the present invention, a soft magnetic layer for connection is further provided between electrode portions formed at both ends of the magnetoresistive effect element, and the soft magnetic layer for connection is connected to the magnetoresistive effect element. It is configured such that the entire end of the element is connected in a state of contact.

According to a preferred aspect of the present invention, the connection soft magnetic layer is provided between the magnetoresistive element and the electrode portions formed at both ends of the magnetoresistive element, and on the lower surface of the electrode portion. Are also formed so as to be in contact with each other.

As a preferred embodiment of the present invention, the magnetic transducer is configured so as not to have a bias magnetic field applying mechanism.

In a preferred embodiment of the present invention, the ferromagnetic layer is formed by applying an external magnetic field of 10 to 300 Oe in the direction of the signal magnetic field and in the in-plane direction of the film at the time of film formation. The soft magnetic layer is formed by applying an external magnetic field of 10 to 300 Oe in the direction perpendicular to the signal magnetic field direction and in the in-plane direction at the time of film formation.

The present invention also provides a non-magnetic metal layer, a ferromagnetic layer formed on one surface of the non-magnetic metal layer, a soft magnetic layer formed on the other surface of the non-magnetic metal layer, A magnetoresistive element comprising a magnetic multilayer film having a pinned layer formed on a ferromagnetic layer for pinning the direction of magnetization of the ferromagnetic layer, the pinned layer comprising: The layers are configured to be joined by epitaxial growth.

In a preferred embodiment of the present invention, when the specific resistance of the pinned layer is ρ _p , the specific resistance of the ferromagnetic layer is ρ _f , and the specific resistance of the soft magnetic layer is ρ _s , The resistance relationship is configured to satisfy the following expression (1).

3 ((ρ _f + ρ _s ) / 2) <ρ _p <30 ((ρ _f + ρ _s ) / 2) Equation (1) As a preferred embodiment of the present invention, 6 Oe width in a high-frequency magnetic field at 1 MHz is used. The slope of the magnetoresistance change at 0.2% / O
e or more.

The present invention also provides a pinning layer for pinning the direction of magnetization of an adjacent ferromagnetic layer, a pair of ferromagnetic layers, a pair of non-magnetic metal layers, A magnetoresistive effect element comprising a magnetic multilayer film having a magnetic multilayer unit in which a pair of soft magnetic layers are sequentially arranged, wherein the ferromagnetic layer and the pinning layer are joined by epitaxial growth. It is configured as follows.

As a preferred embodiment of the present invention, when the specific resistance of the pinned layer is ρ _p , the specific resistance of the ferromagnetic layer is ρ _f , and the specific resistance of the soft magnetic layer is ρ _s , The resistance relationship is configured to satisfy the following expression (1).

3 ((ρ _f + ρ _s ) / 2) <ρ _p <30 ((ρ _f + ρ _s ) / 2) Equation (1) As a preferred embodiment of the present invention, 6 Oe width in a high-frequency magnetic field at 1 MHz. The slope of the magnetoresistance change at 0.2% / O
e or more.

According to the invention relating to the first magnetoresistance effect element, a magnetic multilayer film having an MR gradient of 0.3% / Oe or more and a resistance change rate can be obtained. Moreover, MR in zero magnetic field
The rising characteristics of the curve are extremely good and show high heat resistance. Further, in the invention relating to the second magnetoresistance effect element, the MR gradient at a high frequency of 1 MHz exhibits a high value of 0.3% / Oe or more, the specific resistance is small, and the pressure is 10 ^-7 Torr or less. Thus, a magnetic multi-layer film having high heat resistance without deterioration of characteristics even when heat treatment at about 350 ° C. is obtained. According to the invention relating to the first magnetic transducer having the first magnetoresistive element, it is possible to obtain an output voltage nearly three times as large as that of a conventional material. Further, according to the invention relating to the second magnetic transducer having the second magnetoresistance effect, the MR in the high-frequency region is improved.
The slope shows a high value of 0.3% / Oe or more, the specific resistance is small, the amount of heat generated by the measured current is small, and the output voltage can be 3.8 times. Therefore, it is possible to provide an extremely reliable magnetic transducer such as an MR head capable of reading ultra-high density magnetic recording exceeding 1 Gbit / inch ² .

[0065]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a specific configuration of the present invention will be described in detail.

FIG. 1 is a sectional view of a magnetoresistive element 3 according to a first embodiment of the present invention. The magnetoresistance effect element 3 includes an artificial lattice magnetic multilayer film 1 (hereinafter, simply referred to as a first magnetic multilayer film or a magnetic multilayer film 1). In FIG. 1, a magnetic multilayer film 1 includes a non-magnetic metal layer 30, a ferromagnetic layer 40 formed on one surface of the non-magnetic metal layer 30,
Soft magnetic layer 20 formed on the other surface of nonmagnetic metal layer 30
And a layered structure having a pinning layer 50 formed on the ferromagnetic layer 40 to pin the direction of magnetization of the ferromagnetic layer 40.

As shown in FIG. 1, these laminates are usually formed on a substrate 5, and a metal underlayer 10 is interposed between the substrate 5 and the soft magnetic layer 20. Also,
On the pinning layer 50, a protective layer 80 is formed as shown.

According to the present invention, the magnetization of the soft magnetic layer 20 and the ferromagnetic layer 40 formed adjacently on both sides of the nonmagnetic metal layer 30 via the nonmagnetic metal layer 30 in accordance with the direction of the externally applied signal magnetic field. The orientation needs to be substantially different. This is because the principle of the present invention is that when the magnetization directions of the soft magnetic layer 20 and the ferromagnetic layer 40 formed via the nonmagnetic metal layer 30 are misaligned, the conduction electrons undergo spin-dependent scattering. ,
When the resistance increases and the magnetization directions are opposite to each other,
This is because the maximum resistance is exhibited. That is, in the present invention, as shown in FIG. 2, when the external signal magnetic field is positive (upward from the recording surface 93 of the recording medium 90 (represented by reference numeral 92)), the adjacent magnetic layers Components in which the directions of magnetization are opposite to each other are generated, and the resistance increases.

Here, the external signal magnetic field from the magnetic recording medium, the soft magnetic layer 20 and the ferromagnetic layer 4 in the (spin valve) magnetic multilayer film used in the magnetoresistive element of the present invention.
The relationship between the directions of the 0 magnetization and the change in the electrical resistance will be described.

Now, in order to facilitate understanding of the present invention, as shown in FIG. 1, a pair of the soft magnetic layer 20 and the ferromagnetic layer 40 is present via one non-magnetic metal layer 30. The case of the simple magnetic multilayer film 1 will be described with reference to FIG.

As shown in FIG. 2, the magnetization of the ferromagnetic layer 40 is pinned in a downward direction toward the medium surface by a method described later (reference numeral 41). Since the other soft magnetic layer 20 is formed with the non-magnetic metal layer 30 interposed therebetween, its magnetization direction changes its direction by an externally applied signal magnetic field (reference numeral 21). At this time, the relative angle of the magnetization between the soft magnetic layer 20 and the ferromagnetic layer 40 greatly changes depending on the direction of the signal magnetic field from the magnetic recording medium 90. As a result, the degree of scattering of the conduction electrons flowing in the magnetic layer changes, and the electrical resistance greatly changes.

As a result, a large MR whose mechanism is essentially different from that of the ordinary anisotropic magnetoresistance effect of permalloy.
(Magneto-Resistive) effect is obtained.

The magnetization directions of the soft magnetic layer 20, the ferromagnetic layer 40, and the pinning layer 50 exhibiting the pinning effect change relatively to an external magnetic field. FIG. 3 shows the change in the direction of magnetization corresponding to the magnetization curve and the MR curve. Here, the magnetization of the ferromagnetic layer 40 is fixed in the minus direction (downward from the recording surface of the recording medium 90) by the pinning layer 50. When the external signal magnetic field is negative, the magnetization of the soft magnetic layer 20 is also directed in the negative direction. Now, for the sake of simplicity, the coercive force of the soft magnetic layer 20 and the ferromagnetic layer 40 is set to a value close to zero. In the region (I) where the signal magnetic field H is H <0, the magnetization directions of both the soft magnetic layer 20 and the ferromagnetic layer 40 are still in one direction. When the external magnetic field is raised and H exceeds the coercive force of the soft magnetic layer 20, the magnetization direction of the soft magnetic layer rotates in the direction of the signal magnetic field, and the magnetization directions of the soft magnetic layer 20 and the ferromagnetic layer 40 are antiparallel. , The magnetization and the electric resistance increase. Then, it becomes a constant value (state of area (II)). At this time, a certain pinning magnetic field Hex is operated by the pinning layer 50. When the signal magnetic field exceeds Hex, the magnetization of the ferromagnetic layer 40 also rotates in the direction of the signal magnetic field, and the soft magnetic layer 20 and the ferromagnetic layer 4 in the region (III).
The magnetization directions of 0 are aligned in one direction. At this time, the magnetization becomes a certain value and the MR curve becomes 0.

Conversely, when the signal magnetic field H decreases, the regions (III) to (II) and (I) sequentially change with the reversal of the magnetization of the soft magnetic layer 20 and the ferromagnetic layer 40 as before. I do.
Here, at the beginning of the region (II), the conduction electrons are scattered depending on the spin, and the resistance increases. Area (II)
Among them, the ferromagnetic layer 40 is pinned and hardly reverses the magnetization, but the soft magnetic layer 20 linearly increases its magnetization. The proportion of the conduction electrons that undergo the scattering gradually increases. That is, for example, Hc is applied to the soft magnetic layer 20.
Ni _0.8 Fe _0.2 with a small anisotropic magnetic field H
By adding k, several Oe to several tens below Hk
With a small external magnetic field in the range of Oe, a magnetic multilayer film having a linear resistance change and a large resistance change rate can be obtained.

In the present invention, the thickness of each thin film layer has an individual constraint value. If the thickness of the non-magnetic metal layer is larger than this limit value, the ratio of conduction electrons flowing only in this layer increases, and the overall MR change becomes small, which is not convenient. On the other hand, since conduction electrons are scattered at the interface between the nonmagnetic metal layer and the soft magnetic layer 20 and the ferromagnetic layer 40, the thickness of the two magnetic layers 20 and 40 is 10 μm.
Even if the thickness is greater than 0 °, there is no substantial improvement in the effect. Rather, the overall film thickness is increased, which is not convenient. The lower limit of the thickness of these two magnetic layers 20 and 40 is preferably 20 ° or more. If it is thinner than this, heat resistance and processing resistance will deteriorate.

Hereinafter, each configuration of the first magnetic multilayer film described above will be described in detail. The first feature of this multilayer film is that the ferromagnetic layer 40 and the pinning layer 50 are epitaxially stacked. That is, the ferromagnetic layer 40 and the pinning layer 50 are formed in a state where they are joined by epitaxial growth.

The term “epitaxy” refers to the phenomenon of crystal growth between layers. In the present invention, both atoms of the pinned layer 50 and the ferromagnetic layer 40 formed in contact with the pinned layer 50 are present. It is a state in which the layers are formed along the crystal orientation plane to some extent neatly, and each of these layers is formed with a certain crystallographic relationship. In the present invention, the formed magnetic multilayer film is cut in the lamination direction, and the lamination cross section is observed with a high-resolution electron microscope (TEM). And
By observing the inside of the ferromagnetic layer 40 and the pinning layer 50 and confirming crystal lattice fringes, it can be understood that the crystal orientation of the layers is uniform. The orientation plane can also be identified from the interval. Next, the interface between the pinned layer 50 and the ferromagnetic layer 40 is observed in detail, and if interference between the layers is connected at the interface, epitaxy is established between these layers.
y) Judge that the relationship exists.

As described above, according to the present invention, the ferromagnetic layer 40
The first important requirement is that the layer and the pinning layer 50 are joined by epitaxial growth.
If the layers 40 and 50 are not formed by epitaxial growth, the pinning effect of the pinned layer 50 on the ferromagnetic layer 40 is reduced, and as a result, the soft magnetic layer 20 and the ferromagnetic layer 40 are not connected to each other. Since there is no relative angle between the spins, there is a disadvantage that a large change in electric resistance does not occur.

The ferromagnetic layer 40 is made of Fe, Ni, Co,
Mn, Cr, Dy, Er, Nd, Tb, Tm, Ce, G
d, etc., and alloys and compounds containing these elements. Particularly, (Co _z Ni ₁ -z) _w Fe _{1 -w} (where 0.4 ≦ z ≦ 1.0, 0.5 ≦ w ≦ 1.0)
It is preferable to configure the composition represented by the following formula. If the composition is out of these ranges, a large change in electric resistance cannot be obtained.

The thickness of such a ferromagnetic layer is 20 to 10
0 °, more preferably 20 ° to 60 °. If this value is less than 20 °, the characteristics as a magnetic layer will be lost. On the other hand, when this value exceeds 100 °, the pinning force from the pinning layer 50 becomes small, and the effect of pinning the spin of the ferromagnetic layer cannot be sufficiently obtained.

The pinning layer 50 may be formed by any method that fixes the magnetization of the substantially adjacent magnetic layer. In particular, the antiferromagnetic layer, the hard magnetic layer, and the ferromagnetic layer connected to the pinning layer may be used. It is selected from a pinning ferromagnetic layer made of a material different from 40 and a layer into which artificial structural defects are introduced.

As the antiferromagnetic layer, Fe, Ni, Co, C
A material containing at least two of r, Mn, Ru, Rh, Mo, and O is preferable. For example, FeMn, FeMnPt,
FeMnRu, FeMnRh, FeMnMo, FeNi
O, CoNiO, CrMn, CrMnO, Fe 2 0 3,
NiO or the like is preferred.

The hard magnetic layer is preferably made of one kind of metal selected from Fe, Co and Ni, or a material containing at least 50 at% of one kind of metal selected from Fe, Co and Ni. . For example, FeNi, CoNi, F
eTb, CoPt, CoFePt and the like are preferable.

The ferromagnetic layers made of different materials include F
e, Ni, Co, Mn, Cr, Dy, Er, Nd, T
b, Tm, Ce, Gd, etc., or alloys or compounds containing these elements are used. For example, FeSi, FeNi, FeC
o, FeAl, FeAlSi, FeY, FeGd, Fe
Mn, CoNi, CrSb, Fe-based amorphous alloy,
A Co-based amorphous alloy, MnSb, NiMn, ferrite and the like are preferable.

The same pinning effect can be obtained by artificially introducing a structural defect into the interface between the ferromagnetic layer 40 and the pinning layer 50. This is because, after the ferromagnetic layer 40 is formed, the surface thereof is irradiated with a weak ion beam having an ion current of 10 to 50 mA and an acceleration voltage of 100 to 500 eV for 2 to 20 mA.
Å is obtained by etching the ferromagnetic layer 40. At this time, the magnetization of the ferromagnetic layer 40 is pinned by the introduced structural defect at the interface portion, and has the same effect as the other methods.

By these methods, the adjacent ferromagnetic layers 4
0 and the pinning layer 50 are substantially in direct contact,
Interlayer interaction acts directly on both, and the rotation of magnetization of the ferromagnetic layer 40 is prevented. On the other hand, the soft magnetic layer 20 described in detail later
The magnetization can be freely rotated by an external signal magnetic field. As a result, the soft magnetic layer 20 and the ferromagnetic layer 4
A relative angle is generated between the magnetizations of 0 and 2, and a large MR effect is obtained due to the difference in the direction of the magnetization.

The thickness of the pinning layer 50 is preferably 50 to 700 °. If this value is less than 50 °, the crystallinity of the pinned layer is poor, and a sufficient pinning effect cannot be obtained. As a result, a large MR effect cannot be obtained. If this value exceeds 700 °, the thickness of the entire magnetic multilayer film becomes too thick, and the resistance of the entire film increases. As a result, the rate of change of the MR decreases. In addition, the thickness of the shield layer is increased, which makes it unsuitable for ultra-high density magnetic recording.

The soft magnetic layer 20 is made of Fe, Ni, Co or the like, or an alloy or compound containing these elements.
When a magnetic layer having a small coercive force Hc is used, the rise of the MR curve becomes steeper, and a favorable result is obtained. Particularly preferred is a composition represented by (Ni _x Fe _1-x ) _y Co _1-y (where 0.7 ≦ x ≦ 0.9 and 0.5 ≦ y ≦ 1.0 by weight). Here, if x and y are in this range, Hc becomes small and good soft magnetic characteristics are obtained. As a result, good MR characteristics with high magnetic field sensitivity are obtained. On the other hand, if x and y deviate from this range, Hc becomes large, and there is a disadvantage that MR characteristics with high magnetic field sensitivity cannot be obtained.

Further, the composition of the soft magnetic layer 20 is as follows:
_{Co t M u M 'q B} r ( however, 0.6 ≦ t ≦ with atoms
0.95, 0.01 ≦ u ≦ 0.2, 0.01 ≦ q ≦ 0.
The composition represented by (1, 0.05 ≦ r ≦ 0.3) also shows excellent characteristics. Here, M is at least one selected from Fe and Ni, and M ′ is Zr, S
It represents at least one or more selected from i, Mo, and Nb. When M and M 'are two or more, the total amount of two or more is set to fall within the above composition range. Such a composition has a very excellent characteristic that the MR ratio is larger than that of the above composition because the content of Co is large. In addition, the crystal structure shows better soft magnetic characteristics due to the aggregation of ultrafine crystal grains or the amorphous structure, and as a result, a large MR gradient is obtained. Specific examples of these compositions include Co as a main component, Ni
And / or Fe is selected as a content such that the magnetostriction becomes zero. Zr, Si, Mo, Nb, etc. may be added to this to stabilize the amorphous composition. If Co is less than 0.6, it becomes difficult to obtain amorphous. Although Co may exceed 0.95, it is more convenient to add a small amount of Fe or Ni because characteristics as a soft magnetic material are improved. The content ratio of M ′ satisfies 0.01 ≦ q ≦ 0.1, and if q is less than 0.01, the effect of its addition cannot be obtained. If q exceeds 0.1, the characteristics as a soft magnetic material will deteriorate. B (boron) is a main element for making amorphous, and its content is 0.05 ≦
r ≦ 0.3. If r is less than 0.05, the effect of the addition cannot be obtained. If r exceeds 0.3, the characteristics as a soft magnetic material will deteriorate.

The soft magnetic layer 20 has a thickness of 20 to
100 °, preferably 40 ° to 100 °, more preferably 50 ° to 80 °. If this value is less than 20 °, good characteristics as a soft magnetic layer cannot be obtained. On the other hand, when this value exceeds 100 °, the thickness of the entire multilayer film increases, and the resistance of the entire magnetic multilayer film increases,
The MR effect decreases.

The soft magnetic layer 20 and the ferromagnetic layer 4
The non-magnetic metal layer 30 interposed between 0 and 0 is preferably a conductive metal in order to efficiently guide electrons. More specifically, at least one selected from Au, Ag, and Cu, or at least one or more of
An alloy containing 0 wt% or more is exemplified.

The thickness of the nonmagnetic metal layer 30 is 2
Preferably it is 0-60 °. When this value becomes 20 ° or less, the soft magnetic layer 2
0 and the ferromagnetic layer 40 are exchange-coupled, and the soft magnetic layer 2
There is a disadvantage that the spins of 0 and the ferromagnetic layer 40 do not function independently. This value is 60Å
Is exceeded, the upper and lower soft magnetic layers 20 and the ferromagnetic layers 4
The ratio of the electrons scattered at the interface of 0 causes a phenomenon, and M
There is an inconvenience that the R change rate decreases.

In the relationship between the pinned layer 50, the ferromagnetic layer 40, and the soft magnetic layer 20, the specific resistance of the pinned layer 50 is ρ _p and the specific resistance of the ferromagnetic layer 40 is ρ
_f , when the specific resistance of the soft magnetic layer 20 is ρ _s , it is preferable that these specific resistance relationships satisfy the following expression (1).

3 ((ρ _f + ρ _s ) / 2) <ρ _p <30 ((ρ _f + ρ _s ) / 2) Equation (1) When the value of ρ _p is equal to or less than the lower limit of Equation (1), There is a disadvantage that electron paths are not effectively separated. This ρ
_When the value of _p exceeds the upper limit of the equation (1), the manufacturing method becomes extremely difficult.

The metal underlayer 10 is not particularly limited, but preferably has the same crystal structure as the nonmagnetic metal layer 30 used. That is, the face-centered cubic lattice (f
cc) Ta, Hf, Cu, Au, Ag, Nb, Z
r or an alloy thereof can be used. The metal underlayer 10 is formed for the purpose of improving the crystal orientation of the entire magnetic multilayer film. The thickness is usually 30-30
It is about 0 °.

The protective layer 80 is formed for the purpose of preventing the surface of the magnetic multilayer film from being oxidized during the film forming process, and improving the wettability with the electrode material formed thereon and the adhesion strength. This is Ti, Ta, W, Cr, H
It is formed of a material such as f, Zr, and Zn. The thickness is usually about 30 to 300 °.

The substrate 5 is made of glass, silicon, MgO, Ga
It is formed of a material such as As, ferrite, Altic, and CaTiO ₃ . The thickness is usually 0.5 to 10 mm
Degree.

Next, a magnetoresistive element according to a second embodiment of the present invention, that is, a magnetic multilayer film as shown in FIG. 4 (hereinafter simply referred to as a second magnetic multilayer film or a magnetic multilayer film 2)
Will be described.

The magnetic multilayer film 2 provided in the magnetoresistive element 4 of the second embodiment has a pinning layer 5 as shown in FIG.
0, a pair of ferromagnetic layers 40, 40, a pair of nonmagnetic metal layers 30, 30 and a pair of soft magnetic layers 20,
The magnetic multi-layer unit 7 is provided in which 20 are sequentially arranged. In the case of this embodiment, this unit 7 is formed on a substrate 5 with a metal base layer 10 interposed therebetween as shown in the figure.
Further, a protective layer 80 is formed on the upper soft magnetic layer 20 as shown. Further, a non-magnetic metal layer may be formed between the metal base film 10 and the soft magnetic layer 20. In FIG. 4, the members having the same reference numerals as those used in the description of the magnetic multilayer film 1 (FIG. 1) mean the same members, and have the same basic operation.

As a result of further research on the film configuration of the magnetic multilayer film 1 (FIG. 1) included in the magnetoresistive element 3 of the first embodiment described above, it was found that a large MR effect could be obtained. It has been found that the structure of the magnetic multilayer film 2 as shown in FIG. 4 is particularly preferable.

That is, the pinning layer 50 essentially has a magnetic spin structure fixed in a certain direction with respect to an external signal magnetic field. The magnitude of this spin does not change with an external signal magnetic field. On the other hand, the magnetic multilayer film according to the present invention exhibits a large change in magnetoresistance due to the spin of the soft magnetic layer 20 changing its direction with respect to the signal magnetic field. Therefore, in order to increase the magnetic resistance, the number of the soft magnetic layers 20 in which the spins rotate freely is larger than the number of the pinned layers 50. That is, as shown in FIG.
By forming the soft magnetic layers 20, 20 via the nonmagnetic metal layers 30, 30, the magnetic multilayer film 2 (magnetoresistance effect element 4) having a greatly improved magnetoresistance effect can be manufactured. it can.

The ferromagnetic layer 40, the nonmagnetic metal layer 30, the soft magnetic layer 20, and the pinning layer 50 may be made of the same material and have the same thickness as those described in the first embodiment. desirable. The same applies to the protective layer 80, the metal base film 10, and the substrate 5. In such a magnetic multilayer film 2 as well, the pinned layer 50 and the pair of ferromagnetic layers 40 formed on both sides of the pinned layer 50 need to be joined by epitaxial growth.

The spins of the ferromagnetic layers 40 and 40 and the soft magnetic layers 20 and 20 contribute to the scattering of conduction electrons. The most efficient scattering occurs when the magnitudes of the two spins are almost the same. That is, it is basically preferable that the amount of magnetization of each layer is substantially the same.
However, in the case of the magnetic multilayer film 2 of the second embodiment, the ferromagnetic layers 40, 40 have a structure formed on both sides of the pinning layer 50. Scattering is more efficiently performed when the magnetization of the ferromagnetic layer 40 is smaller than the magnetization of the soft magnetic layer 20. If the thickness of the ferromagnetic layer 40 is too large, the magnetization of the entire layer 40 becomes larger than the magnetization of the soft magnetic layer 20. Therefore, when the thickness of the ferromagnetic layer 40 is set so that these values become almost the same, Good. Specifically, when the magnetization of the ferromagnetic layer 40 is Mf and the magnetization of the soft magnetic layer 20 is Ms, 0.3 M
s ≦ Mf ≦ 0.8Ms, preferably 0.4Ms ≦ Mf
≤ 0.7 Ms so that each layer 20 and 4
When the thickness is adjusted to 0, the balance between the layer thickness and the scattering efficiency is improved.

The material and layer thickness of each layer are defined as described above, and at least at the time of forming the soft magnetic layer 20, an external magnetic field is applied in one direction in the film plane, which will be described later, and the anisotropic magnetic field Hk 3 to 20 Oe, more preferably 3 to 16 Oe, especially 3
It is preferable to add ~ 12 Oe. Thereby, the formed magnetic multilayer film 2 (magnetoresistive element 4) has an MR gradient of 0.3% /
Oe or more, especially 0.4% / Oe or more, usually 0.4 to 1.0%
/ Oe is obtained. Further, the maximum hysteresis width of the MR change curve is 8 Oe or less, usually 0 to 6 Oe. Moreover,
MR slope in high frequency magnetic field of 1MHz is 0.2% / Oe or more,
More preferably 0.25 or more, usually 0.3 to 1.0% /
Oe can be obtained, and sufficient performance can be obtained when used for a read MR head for high-density recording.
In the magnetic multilayer film 1 (the magnetoresistive element 3) of the first embodiment, the soft magnetic layer 20 is preferably subjected to the same processing. If the anisotropic magnetic field Hk of the soft magnetic layer is less than 3 Oe, it becomes almost equal to the coercive force, and a linear MR change curve centered on 0 magnetic field cannot be substantially obtained. The characteristics deteriorate. On the other hand, if it is larger than 20 Oe, the MR gradient becomes small, and when this film is applied to an MR head or the like, the output tends to decrease and the resolution decreases. Here, these Hk are obtained by applying a magnetic field of 10 to 300 Oe during film formation as an external magnetic field. If the external magnetic field is less than 10 Oe, it is not enough to induce Hk, and even if it exceeds 300 Oe, the effect is not changed.
The coil for generating the magnetic field becomes large, which is expensive and inefficient.

Note that the MR change rate is obtained by calculating the maximum specific resistance as ρmax.
, When the minimum specific resistance is ρsat, (ρmax −ρsat
) × 100 / ρsat (%). Also, the maximum hysteresis width is determined by the magnetoresistance change curve (MR curve).
Is the maximum value of the hysteresis width calculated by measuring. Further, the MR slope is the maximum value of the differential value at −20 to +20 Oe obtained by measuring the MR curve and obtaining the differential curve. The high-frequency MR gradient is the MR gradient when the MR change rate is measured with an alternating magnetic field having a magnetic field width of 1 MHz and 6 Oe.

The magnetic multilayer film 1 and the magnetic multilayer film 2 in the first and second embodiments described above may be repeatedly laminated to form a magnetoresistive element. The number n of repeated laminations of the magnetic multilayer film is not particularly limited, and may be appropriately selected according to a target magnetoresistance change rate or the like. In order to cope with the recent ultra-high density of magnetic recording, the thinner the total thickness of the magnetic multilayer film, the better. However, when the thickness is reduced, the MR effect usually decreases at the same time, but the magnetic multilayer film used in the present invention can obtain a multilayer film that can sufficiently withstand practical use even when the number n of times of repeated lamination is one. In addition, as the number of layers increases, the rate of change in resistance also increases. However, productivity deteriorates. Further, if n is too large, the resistance of the entire element becomes too low, which causes practical inconvenience. Is preferably 10 or less.
Note that the long-period structure of the artificial lattice can be confirmed by the appearance of primary and secondary peaks corresponding to the repetition period in a small-angle X-ray diffraction pattern. A preferable range of n is 1 to 5 for application to a magnetic transducer such as an MR head for ultrahigh density magnetic recording.

The layers of the magnetic multilayer films 1 and 2 are formed by a method such as an ion beam sputtering method, a sputtering method, a vapor deposition method, and a molecular beam epitaxy method (MBE). As described above, the substrate 5 is made of glass, silicon, MgO, GaAs, ferrite, Altic, C
aTiO ₃ or the like can be used. When forming a film,
As described above, when forming the soft magnetic layer 20, it is preferable to apply an external magnetic field of 10 to 300 Oe in one direction in the film plane. Thereby, Hk can be given to the soft magnetic layer 20. The method of applying the external magnetic field is applied only when the soft magnetic layer 20 is formed, using a device having an electromagnet or the like that can easily control the application time of the magnetic field, and is not applied when the pinned layer 50 is formed. It may be a method. Alternatively, a method of constantly applying a constant magnetic field throughout the film formation may be used.

Next, the invention of the magnetoresistive element 3 having the magnetic multilayer film 1 described in the first embodiment is developed, and the path through which electrons flow is examined in detail. Invented the invention. The magneto-resistive element referred to here includes a magneto-resistive effect element, a conductive film, and an electrode portion. More specifically, the magneto-resistive head (M
R head), an MR sensor, a ferromagnetic memory element, an angle sensor, and the like.

Here, a magnetoresistive head (MR head) will be described as an example of the magnetic transducer.
explain.

As shown in FIG. 5, the first magneto-resistance effect type head (MR head) 150 includes a magneto-resistance effect element 200 as a magneto-sensitive portion for sensing a signal magnetic field, and a magneto-resistance effect element. 200 both ends 200a, 200a
And electrode portions 100, 100 formed on the substrate. The ends 200a, 200a of the magnetoresistive element 200 as the magneto-sensitive portion are entirely formed at both ends thereof.
It is preferable that the connection is made in contact with 0,100. In addition, the conductor films 120 and 120 are provided on the electrode portion 10.
It is electrically connected to the magnetoresistive element 200 via 0 and 100. In the present invention, the conductor film 120 and the electrode portion 100 are divided into a conductor film 120 and an electrode portion 100 for the sake of simplicity in order to make the following description easy to understand. In many cases, these may be considered as one member.

The magnetoresistive element 200 as the magneto-sensitive part in the first MR head has a laminated structure substantially similar to the magnetoresistive element 3 having the magnetic multilayer film 1 shown in FIG. Can be That is, the magnetoresistive element 200 is replaced by the magnetoresistive element 3 having the magnetic multilayer film 1 shown in FIG. 1, and as a result, the magnetoresistive element 200 has the magnetic metal layer 30 and the non-magnetic metal layer 30. The ferromagnetic layer 40 formed on one surface of the non-magnetic metal layer 3
A soft magnetic layer 20 formed on the other surface of the ferromagnetic layer 40 and a ferromagnetic layer 40 for pinning the magnetization direction of the ferromagnetic layer 40.
And a pinning layer 50 formed thereon. The ferromagnetic layer 40 and the pinning layer 50 are joined by epitaxial growth.

As shown in FIG. 5, shield layers 300, 300 are formed so as to sandwich the magnetoresistive element 200 and the electrode portions 100, 100, and the magnetoresistive element 200 and the shield layers 300, 30 are formed.
The non-magnetic insulating layer 400 is formed in a portion between 0.

Here, the ferromagnetic layer 40, the non-magnetic metal layer 30, and the
The soft magnetic layer 20 and the pinning layer 50 are made of the same material as the film 1 described in the first embodiment of the first magnetic multilayer film, respectively.
It is desirable to use one having a thickness. Here, as a result of a detailed study of the path of the current flowing through the magnetic multilayer film of the magnetoresistive element 200, it was found that electrons as a current were flowing to a certain portion in the magnetic multilayer film. That is,
Among the layers constituting the magnetic multilayer film, the pinning layer 50 is a material having a large specific resistance. For example, FeMn is 100 to
Although the specific resistance is 200 μΩcm, FeNi is 15-30
μΩcm, quite small. Therefore, electrons flow to the soft magnetic layer 20 and the non-magnetic metal layer 30 having a small specific resistance. In the conventional MR head, an electrode is formed on the upper surface of the NiFe layer after forming the NiFe layer as a magnetically sensitive portion.
In this case, since the electrode is in contact with the pinning layer having a large specific resistance, it is difficult for the current to flow effectively. Further, the contact resistance is large, and the yield is reduced in the manufacturing process.

Therefore, as shown in FIG. 5, these problems are solved by forming the electrode portion 100 through which a current flows so that the ends 200a and 200a of the magnetoresistive element 200 are entirely in contact with each other in the stacking direction. You can do it. That is, the electrons flow around the portion between the soft magnetic layer 20 and the ferromagnetic layer 40. Then, magnetic scattering is caused by the direction of spin between the soft magnetic layer 20 and the ferromagnetic layer 40, and the resistance greatly changes. Therefore, a minute change in the external magnetic field can be detected as a large change in electric resistance.

Further, the invention of the magneto-resistance effect element having the magnetic multilayer film 2 as described with reference to FIG. 4 is developed, and the magnetic conversion element having two or more electron flow paths centering on the pinned layer 50 is developed. An embodiment of the second MR head will be described. The basic configuration of this element is the same as that shown in FIG. 5, and the magnetoresistive element 200 having the magnetic multilayer film as the magneto-sensitive portion is different from the magnetoresistive element having the magnetic multilayer film 2 shown in FIG. A laminated structure substantially similar to that of No. 4 is used. That is, in FIG. 5, the magnetoresistive element 200 can be considered to be substantially replaced with the magnetoresistive element 4 having the magnetic multilayer film 2 shown in FIG. Both ends of the magnetoresistive element 200 are connected such that the entire ends 200a, 200a are in contact with the electrodes 100, respectively. That is, the structure is such that the entire stacking direction of the magnetoresistive element 200 and the electrode portion are in contact.

The structure of the magnetoresistive element 200 in the second MR head will be specifically described with reference to FIG. The magnetic multilayer film of the magnetoresistive element 200 includes a metal underlayer 10, a soft magnetic layer 20, a nonmagnetic metal layer 30, a ferromagnetic layer 40, a pinning layer 50, a ferromagnetic layer 40, a nonmagnetic metal The layer 30, the soft magnetic layer 20, and the metal protective layer 80 are stacked in this order. The pinned layer 50 and the pair of ferromagnetic layers 40 formed on both sides of the pinned layer 50
They are joined by epitaxial growth.

When electrons flow through the magnetic multilayer, the thickness of each layer is extremely small, so that the electrons flow through the multilayer with a quantum probability. That is, although the electrons flow stochastically throughout the multilayer film, the ratio of the electrons flowing in the layer having a large specific resistance naturally becomes low. Generally, the pinned layer 50 is two times smaller than the nonmagnetic metal layer 30 and the soft magnetic layer 20.
It has more than twice the specific resistance. For example, the antiferromagnetic material Fe
Mn has a specific resistance of 100 to 200 μΩcm, whereas FeNi which is a soft magnetic material has a considerably small value of 15 to 30 μΩcm. Therefore, electrons flow to the soft magnetic layer 20 and the non-magnetic metal layer 30 having a small specific resistance. Here, the ferromagnetic layer 4 is almost symmetrically centered on the pinning layer 50 having a large specific resistance.
0, the non-magnetic metal layer 30 and the soft magnetic layer 20 are arranged, so that when electrons flow in the multilayer film, there are two or more electron flow paths with the pinning layer 50 as a boundary. . As described above, electrons flow stochastically throughout the multilayer film. Among them, by arranging a layer having high specific resistance, it is necessary to form at least two or more electron flow paths. Is possible. As a result, the number of electrons which are magnetically scattered by the magnetization which has been made antiparallel by the external magnetic field increases, and the MR effect becomes larger as compared with the case where the current path is substantially one.

At this time, in order to make the number of paths through which electrons flow substantially two or more, as described above, the specific resistance of the pinned layer 50 is ρ _p , the specific resistance of the ferromagnetic layer 40 is ρ _f , Assuming that the specific resistance of the magnetic layer 20 is ρ _s , it is preferable that these specific resistance relationships satisfy the following expression (1).

3 ((ρ _f + ρ _s ) / 2) <ρ _p <30 ((ρ _f + ρ _s ) / 2) Equation (1) Note that there are substantially 2 to 10 paths through which electrons flow. It is desirable. This may be achieved by forming a multilayer film including one to four pinning layers 50 with the above-described configuration. When there are three paths, for example, a soft magnetic layer 20, a non-magnetic metal layer 30, a ferromagnetic layer 40,
Pinned layer 50, ferromagnetic layer 40, nonmagnetic metal layer 30, soft magnetic layer 20, nonmagnetic metal layer 30, ferromagnetic layer 40, pinned layer 50, ferromagnetic layer 40, nonmagnetic metal layer 30, soft magnetic The layer 20 and the protective layer 80 are laminated in this order. In addition, route 4
For example, when the soft magnetic layer 20, the non-magnetic metal layer 30, and the ferromagnetic layer 4 are formed on the metal underlayer 10 on the substrate 5,
0, pinned layer 50, ferromagnetic layer 40, nonmagnetic metal layer 3
0, soft magnetic layer 20, non-magnetic metal layer 30, ferromagnetic layer 40,
Pinned layer 50, ferromagnetic layer 40, nonmagnetic metal layer 30, soft magnetic layer 20, nonmagnetic metal layer 30, ferromagnetic layer 40, pinned layer 50, ferromagnetic layer 40, nonmagnetic metal layer 30, soft magnetic The layer 20 and the protective layer 80 are laminated in this order. This route is 1
If the value is 0 or more, the thickness of the entire magnetic multilayer film becomes large, and it cannot be applied to an MR head or the like for ultra-high density magnetic recording. Although one path may be used, two or more paths are preferable in order to obtain a larger MR effect. In application, it is more preferably 2 to 5.

As described above, both ends 200a, 200a of the magnetoresistive element 200 are connected so that the entire ends thereof are in contact with the electrode portion 100, respectively. Therefore, all the electrons flow equivalently around the portion between the formed two or more soft magnetic layers 20 and the ferromagnetic layer 40.
Then, the ratio of electrons that are magnetically scattered by the spin directions of the soft magnetic layer 20 and the ferromagnetic layer 40 is increased as compared with the case of one path, and the change in magnetoresistance is enhanced. Therefore, a small change in the external magnetic field can be detected as a large change in electric resistance. Further, since the pinned layer 50 has a large specific resistance of 100 μΩcm or more as described above, the specific resistance of the entire magnetic multilayer film as a magnetically sensitive portion increases. Although it is 3 to 10 times as large as that of the conventional material NiFe (permalloy), it is possible to reduce the specific resistance to the same level as permalloy by forming a large number of paths through which electrons flow. Become. As a result, the temperature rise of the magneto-sensitive part due to the flow of the measurement current,
It is possible to avoid the characteristic deterioration accompanying it.

As described above, when there are two or more electron flow paths with the pinning layer 50 as a boundary, when the magnetization of the ferromagnetic layer is Mf and the magnetization of the soft magnetic layer is Ms, When each layer thickness is adjusted so that 0.3 Ms ≦ Mf ≦ 0.8 Ms, preferably 0.4 Ms ≦ Mf ≦ 0.7 Ms, the balance between each layer thickness and the scattering efficiency is improved.

The material and thickness of each layer of the magnetoresistive element 200, which is a magneto-sensitive part in the second MR head, may be the same as those of the magnetoresistive element 4 having the magnetic multilayer film 2 described above.

As described above, an anisotropic magnetic field Hk is induced by applying an external magnetic field in at least one direction in the film plane at least at the time of forming the soft magnetic layer 20, thereby further improving the high frequency characteristics. can do. Here, the magnetic multilayer film has M
An external magnetic field is applied in a direction in which a current for causing the R effect flows, thereby inducing an anisotropic magnetic field. Usually, a magnetic multilayer film is processed into a strip shape and a current flows in the longitudinal direction. Therefore, it is preferable to form a film by applying a magnetic field in the longitudinal direction.
In other words, the film may be formed by applying a magnetic field in the same direction as the direction in which the current flows as the MR head, that is, perpendicular to the signal magnetic field direction and in-plane. Then, the soft magnetic layer constituting the magnetic multilayer film has the longitudinal direction of the strip in the direction of easy magnetization,
The direction of the short side of the strip becomes the direction of hard magnetization, and the anisotropic magnetic field Hk is generated. Here, since the signal magnetic field is applied in the short side direction of the strip-shaped magnetic multilayer film, the high-frequency magnetic characteristics of the soft magnetic layer are improved, and the MR characteristics in a large high-frequency region are obtained. The magnitude of the applied magnetic field may be in the range of 10 to 300 Oe. Then, the anisotropic magnetic field Hk induced in the soft magnetic layer 20
Is 3 to 20 Oe, more preferably 3 to 16 Oe, especially 3 to 1 Oe.
It is good to be 2 Oe. If the anisotropic magnetic field Hk is less than 3 Oe, the coercive force of the soft magnetic layer 20 is substantially the same, and a linear MR change curve centered on the zero magnetic field cannot be substantially obtained. to degrade. On the other hand, if it is larger than 20 Oe, the MR gradient (MR change rate per unit magnetic field) becomes small, and when used as an MR head or the like, the output tends to decrease and the resolution decreases. The film of the present invention exhibits high heat resistance, and has an MR gradient of 0.3% / Oe or more, particularly 0.4% / Oe or more at the rising portion of the MR change curve.
Usually 0.4 to 1.0% / Oe is obtained. Further, the maximum hysteresis width of the MR change curve is 8 Oe or less, usually 0 to 6 Oe. Furthermore, the MR gradient in a high-frequency magnetic field of 1 MHz can be 0.2% / Oe or more, more preferably 0.25 or more, usually 0.3 to 1.0% / Oe. Sufficient performance can be obtained as a read MR head or the like.

Further, when forming an antiferromagnetic layer as the pinning layer 50, it is preferable to apply a magnetic field in a direction perpendicular to the direction of the applied magnetic field when forming the soft magnetic layer 20. In other words, the direction is in the plane of the magnetic multilayer film and perpendicular to the measured current.
The magnitude of the applied magnetic field may be in the range of 10 to 300 Oe. As a result, the magnetization direction of the ferromagnetic layer 40 is reliably fixed in the direction of the applied magnetic field (perpendicular to the measurement current) by the pinning layer 50, and the magnetization of the soft magnetic layer 20 whose direction can be easily changed by the signal magnetic field. The most rational antiparallel state can be created. However, this is not a necessary condition, and may be the same as the direction of the magnetic field applied when forming the soft magnetic layer when forming the antiferromagnetic layer. At this time, after performing the heat treatment at about 200 ° C. in the process after the formation of the magnetic multilayer film, a magnetic field is applied in the direction of the short side of the strip (perpendicular to the direction of the applied magnetic field when the soft magnetic layer 20 is formed). It is preferable to lower the temperature while applying the voltage.

The rising portion of the MR curve is defined by the magnetization rotation of the soft magnetic layer 20. In order to obtain a steeper rise of the MR curve, it is desirable that the soft magnetic layer 20 completely changes the direction of the magnetization by the rotation of the magnetization with respect to the signal magnetic field. However, actually, magnetic domains are generated in the soft magnetic layer 20, and domain wall movement and magnetization rotation occur simultaneously with respect to the signal magnetic field. As a result, Barkhausen noise occurred, and the MR head characteristics became unstable.

Therefore, as a result of intense research, the inventors have found that, as shown in FIG. 6, the magneto-resistive effect element 200, which is a magneto-sensitive part, and the electrode part 100 for flowing a measurement current are respectively disposed. It was confirmed that the noise was improved by interposing the soft magnetic layer 500 for connection. Of course, in this case, the connection soft magnetic layer 500 and the entire ends 200 a and 200 a of the magnetoresistive element 200 are connected in contact with the connection soft magnetic layer 500. The connecting soft magnetic layers 500 and 500 formed adjacent to the magnetoresistive element (magnetic multilayer film) are in direct magnetic contact with the soft magnetic layer constituting the magnetic multilayer film. The added soft magnetic layer 500 for connection has the effect of bringing the magnetic domains of the soft magnetic layer in the magnetic multilayer film closer to a single magnetic domain structure and stabilizing the magnetic domain structure. As a result, the soft magnetic layer in the magnetic multilayer film operates in the magnetization rotation mode with respect to the signal magnetic field, and has no noise.
Good characteristics can be obtained.

In order to make the magnetic domain of the soft magnetic layer in the magnetic multilayer film close to a single magnetic domain and to stabilize the magnetic domain structure, FIG.
Soft magnetic layers 510, 510 having a shape as shown in FIG.
Is preferably provided. This coupling soft magnetic layer 510
Are the magneto-resistive element 200, which is a magnetically sensitive part, and the electrode part 1
In addition to the area between the electrodes 100 and 00, they are continuously formed on the lower surface 101 of the electrode section 100. This is because the larger the volume of the coupling soft magnetic layer 510 for stabilizing the magnetic domain structure, the greater the degree of stabilization. Moreover, since the voltage effect does not occur if it is in direct contact with the electrode portion 100, the MR effect of the coupling soft magnetic layer itself for stabilizing the magnetic domain structure does not affect the MR effect of the magnetic multilayer film, which is convenient. . In order to more positively stabilize the magnetic domains of the soft magnetic layer in the magnetic multilayer film, an antiferromagnetic layer is provided between the connecting soft magnetic layer for stabilizing the magnetic domain structure and the electrode portion 100. May be interspersed.

Generally, in an MR head using permalloy, a shunt layer of Ti or the like, CoZrMo, Ni
A bias magnetic field applying layer made of a soft magnetic material having a large specific resistance such as FeRh is provided adjacent to the magneto-sensitive portion. These are called soft film biases or shunt biases, which shift the permalloy curve and create a linear region around zero magnetic field. However, these mechanisms are complicated, and in fact, cause a significant reduction in the manufacturing yield in the manufacturing process. On the other hand, in the above-described magnetoresistive effect element (magnetic multilayer film) of the present invention, since the MR curve rises from a position very close to zero magnetic field, the self-generated current caused by the current flowing through the magnetoresistive effect element (magnetic multilayer film) The bias can create a linear region around a zero magnetic field. As a result, since there is no need to provide a bias method for a complicated mechanism, there are effects such as an improvement in manufacturing yield, a reduction in manufacturing time and a reduction in cost. In addition, since the thickness of the magneto-sensitive portion is reduced by the absence of the bias mechanism, the shield thickness in the case of an MR head is reduced, which has a great effect on shortening the signal wavelength by ultra-high density recording.

When these MR heads are manufactured, heat treatments such as baking, annealing, and resist curing are inevitable during the manufacturing process, such as patterning and flattening.

In general, magnetoresistance effect elements having a magnetic multilayer film called an artificial lattice often have a problem in heat resistance due to the thickness of each of the constituent layers. In the magnetoresistive effect element (magnetic multilayer film) according to the present invention, a magnetic field is applied, and an anisotropic magnetic field is applied to the magnetic layer.
0 ° C or less, generally 50 to 400 ° C, 100 to 300 ° C,
It can sufficiently cope with heat treatment for about 2 hours. Heat treatment is usually
It may be carried out in a vacuum, in an inert gas atmosphere, in the air, or the like. In particular, when the treatment is carried out in a vacuum (under reduced pressure) of 10 ^-7 Torr or less, a magnetoresistive element (magnetic multilayer film) with extremely little characteristic deterioration is obtained. Can be In addition, even in lapping and polishing in the processing step, the MR characteristics hardly deteriorate.

[0131]

The invention of the first and second magnetoresistive elements and the invention of the first and second magnetic transducers (for example, MR heads) using them will be further described by the following concrete examples. This will be described in detail. First, a specific embodiment of the invention of the magnetoresistive element 3 (corresponding to FIG. 1) having the magnetic multilayer film 1 will be described as a first embodiment.

Example 1 A glass substrate was used as a substrate, placed in an ion beam sputtering apparatus, and evacuated to 1 × 10 ⁻⁷ Torr. The substrate temperature is kept at 20
While rotating at rpm, an artificial lattice magnetic multilayer film having the following composition was prepared. At this time, a magnetic field is applied in the plane of the substrate and
Film formation was performed at a film formation rate of about 0.3 ° / sec or less while applying a current in a direction parallel to the measurement current. Ar flow rate is 8-10scc
m, the acceleration voltage of the sputter gun was 300 V, and the ion current was 30 mA. After the film formation, the film was cooled from 150 ° C. in a vacuum of 10 ⁻⁵ Torr while applying a magnetic field of 200 Oe in a direction perpendicular to the measurement current and in the plane, to induce a pinning effect of the ferromagnetic layer. Thus, Samples 1 to 11 of the present invention as shown in Table 1 were prepared.

In Table 1, for example, sample 1 contains [N
i _0.81 Fe _0.19 (70) -Cu (30) -Ni _0.81 Fe
_0.19 (70) -Fe _0.5 Mn _0.5 (70)]
70% thick Ni81% -Fe19% Permalloy (NiFe) alloy soft magnetic layer, 30% Cu nonmagnetic metal layer, 70% thick NiFe ferromagnetic layer, and 70% thick Fe50% -Mn50% FeMn alloy Is a magnetic multilayer film obtained by sequentially sputtering the antiferromagnetic layers. The materials constituting each sample are shown as (m1, m2, m3, m4) in the order of soft magnetic layer, non-magnetic metal layer, ferromagnetic layer, and pinned layer. Further, their layer thicknesses are set in the same order (t1, t2, t
3, t4) and Table 1. For each sample,
A 50 ° Ta layer was provided as an underlayer (between the substrate and the soft magnetic layer) and a protective layer (above the antiferromagnetic layer).

In the m1 material in Table 1, NiFe (samples 1, 2, 3, 10 to 13, 15, 17) was
_0.81 Fe _0.19 (wt ratio), and CoFeNiB (samples 4 and 7) is (Co _0.88 Fe _0.06 Si _0.06 ) _0.80 B
_0.20 (at ratio), NiFeCo (sample 5,
9) represents Ni _0.17 Fe _0.35 Co _0.48 (wt ratio),
NiFeCo (samples 6 and 8) is Ni _0.15 Fe _0.69
Co _0.16 (wt ratio).

In the m4 material shown in Table 1, samples 1 and 2
Samples 2 and 4 to 7 are examples of antiferromagnetic layers, samples 8 and 9 are examples of hard magnetic layers, samples 3 and 10 are examples of ferromagnetic layers of different materials, and sample 11 is structural defects. This is an example of an introduction layer, that is, an example in which this layer is formed while introducing a structural defect during the formation of the Fe ₃₀ Tb ₇₀ layer. Further, m in Table 1
In the four materials, CoPt of sample 8 is Co _0.14 Pt
_0.86 (at ratio), CoSm of the sample is Co _0.63 Sm
_0.37 (at ratio), the CoFe of sample 3 was Co _0.81 F
e _0.19 , and CoFeNi of sample 10 is Co _0.72 Fe
_0.13 Ni represents _0.15 .

Hereinafter, the characteristic evaluation common to the respective inventions will be described. The measurement of the BH loop was performed with a vibrating magnetometer. In the resistance measurement, a sample having a shape of 0.5 × 10 mm was prepared from the sample having the configuration shown in Table 1, and an external magnetic field was applied in the plane in a direction perpendicular to the current.
The resistance when changing from 300 to 300 Oe was measured by the four-terminal method, and the minimum value ρsat of the specific resistance and the MR change rate ΔR / R were determined from the resistance. MR change rate ΔR / R
Was calculated by the following equation, where ρmax is the maximum specific resistance and ρsat is the minimum specific resistance: ΔR / R = (ρmax−ρsat) × 1
00 / ρsat (%). Further, a differential curve of the measured MR curve was taken, and the maximum value near the zero magnetic field was defined as the MR gradient (unit% / Oe), and the rise characteristics were evaluated. This value needs to be 0.3% / Oe or more as described above.

Sample 1 has two magnetic layers, NiFe
(Permalloy). Although the MR change rate is 1.8%, the MR gradient is a large value of 0.57% / Oe. FIG. 8 shows an MR curve measured with a DC magnetic field. This is the output voltage measured at a measurement current of 5 mA. The MR curve rises significantly near the zero magnetic field, indicating a large MR gradient. In sample 2, when the ferromagnetic layer is Co, sample 3 is pinned by direct exchange coupling using ferromagnetic layers of different materials. In this sample 3, before the FeCo layer was sputtered, the Ar flow rate was 10 sccm, the acceleration voltage of the ion gun was 100 V,
An assist ion beam with an ion current of 10 mA was applied to roughen the interface and introduce artificial structural defects.

The sample 1 of the present invention shown in Table 1
X-ray diffraction and transmission electron microscopy of cross sections of the samples No. to No. 11 show that the ferromagnetic layer and the so-called pinned layer are connected to each other by lattice fringes, and that the layers are formed by epitaxial growth. Was confirmed.

Sample 12 (comparative) shown in Table 1 has the same multilayer structure as sample 1, but due to the difference in film formation conditions, the ferromagnetic layer and the so-called pinned layer are formed by epitaxial growth. Not an example.
The specific film forming conditions of the sample 12 (comparative) are as follows.
0-20 SCCM, acceleration voltage of sputter gun is 1200V,
The ion current is set to 120 mA, and the other conditions are the same as the above film forming conditions. Under such film forming conditions, since the energy of the sputter beam is large, the kinetic energy of the particles sputtered from the target and deposited on the substrate is also large, and the energy of each layer is increased at the interface of the magnetic multilayer film. The materials caused interdiffusion, and a film could not be obtained by epitaxial growth.

Samples 13 (comparison) and 14 (comparison)
Are examples in which a pinning layer (corresponding to m4) is not formed.

Sample 15 (comparison) is an example in which the ferromagnetic layer and the so-called pinned layer are not formed by epitaxial growth due to a difference in film formation conditions, although the multilayer structure is the same as that of sample 1. That is, sample 15
(Comparative) is a film formed by the RF sputtering method. Ultimate pressure 6 × 10 ^-7 Torr, pressure during film formation 0.5 mTor
r. The Ar flow rate was in the range of 8 to 20 SCCM. As a result of observing the cross section of the multilayer film with a high-resolution electron microscope (TEM), crystal lattice fringes between the pinned layer and the ferromagnetic layer were not confirmed. Therefore, there was no state of epitaxial growth between these layers.

Sample 16 (comparison) is an example in which the ferromagnetic layer and the so-called pinned layer are not formed by epitaxial growth due to the difference in film formation conditions, although the multilayer structure is the same as that of Sample 8. Sample 16 (comparison)
Is formed by a film forming method similar to that of the sample 15 (comparative).

Sample 17 (comparative) has the same multilayer structure as sample 10, but is an example in which the ferromagnetic layer and the so-called pinned layer are not formed by epitaxial growth due to the difference in film formation conditions. Sample 17 (comparison)
Is formed by a film forming method similar to that of the sample 15 (comparative).

[0144]

[Table 1] According to the results shown in Table 1, a ferromagnetic layer and a so-called pinned layer are formed by epitaxial growth, and the magnetization direction of the ferromagnetic layer is pinned to show a large MR gradient exceeding 0.3% / Oe. This can be seen (Samples 1 to 11 of the present invention). This pinning effect has no effect unless the pinning layer is formed by epitaxial growth with the magnetic layer. In addition, it can be seen that the pinning effect is provided by one selected from an antiferromagnetic layer, a hard ferromagnetic layer, a ferromagnetic layer having a different material, and a layer having an artificial structural defect.

Next, a second embodiment of the invention of a magnetoresistive element 4 (corresponding to FIG. 4) having a magnetic multilayer film 2 will be described.

Example 2 A glass substrate was used as a substrate, placed in an ion beam sputtering apparatus, and evacuated to 1 × 10 ⁻⁷ Torr.
While rotating the substrate while keeping the substrate temperature at 10 ° C., an artificial lattice magnetic multilayer film having the following composition was prepared.
At this time, film formation was performed at a film formation rate of about 0.3 ° / sec or less while applying a magnetic field in the plane of the substrate and in a direction parallel to the measurement current. The Ar flow rate was 8 sccm, the acceleration voltage of the sputter gun was 300 V, and the ion current was 30 mA. After film formation, 10
^In a vacuum of ^-7 Torr, perpendicular to the measured current and 20 in the in-plane direction
It was cooled from 150 ° C. while applying a magnetic field of 0 Oe to induce a pinning effect of the ferromagnetic layer.

Table 2 below shows the structure of the magnetic multilayer film and the rate of change in magnetoresistance.

In Table 2, for example, sample 2-
1 is [Ni _0.81 Fe _0.19 (70) -Cu (30) -N
i _0.81 Fe _0.19 (70) -Fe _0.5 Mn _0.5 (70)-
Ni _0.81 Fe _0.19 (70) -Cu (30) -Ni _0.81 F
e _0.19 (70)] and a 70% thick Fe50% -M
On both sides of an antiferromagnetic layer (pinning layer) of a 50% FeMn alloy, a 70 ° thick N layer used as a ferromagnetic layer was used.
iFe alloy layer, 30% thick non-magnetic metal layer of Cu, 70% thick
Permalloy composition of Ni81% -Fe19% thick (NiF
This is a magnetic multilayer film in which a soft magnetic layer according to e) and a 70 ° thick Ta metal layer are sequentially arranged. The materials constituting each sample are shown as (m1, m2, m3, m4) in the order of soft magnetic layer, non-magnetic metal layer, ferromagnetic layer, and antiferromagnetic layer (pinning layer). In addition, their layer thicknesses are set in the same order (t1, t2,
t3, t4) and Table 2. In the following examples, the compositions of the NiFe and FeMn layers are the same as in Examples 1 and 2. Also, the MR gradient in a DC magnetic field, and 1
The MR gradient (unit% / Oe) at a width of 6 Oe in a high frequency magnetic field at MHz is also shown. This value is 0.2 as described above.
% / Oe or more. In addition, when the magnetization of the ferromagnetic layer is Mf and the magnetization of the soft magnetic layer is Ms, Mf /
The value of Ms is shown. It is necessary to select the thickness of each layer so that this value is 0.3 to 0.8.

[0149]

[Table 2] Samples 2-1 to 2-4 shown in Table 2 have the structure according to the invention of the magnetoresistive element 4 (corresponding to FIG. 4) having the magnetic multilayer film 2, and Samples 1 and 2 shown in Table 2
2 are the same as Samples 1 and 2 in Table 1, respectively.
One soft magnetic layer and one antiferromagnetic layer (corresponding to FIG. 1). Samples 2-1 to 2-4 were observed by X-ray diffraction and observation of the cross section of the laminated film by a transmission electron microscope.
In addition, it was confirmed that the stack of the ferromagnetic layer and the so-called pinned layer in each of Samples 1 and 2 was formed by epitaxial growth.

In sample 2-5 (comparative), Ta (50 °) was formed as an underlayer on a substrate, and NiFe was formed thereon.
(70 °), Cu (30 °), NiFe (70 °), F
eMn (70 °), Cu (30 °), NiFe (70 °)
Å), Cu (30 °), NiFe (70 °), FeMn
(70 °) and Cu (30 °) were sequentially formed.
The conditions for forming the film were as follows:
Performed under the same conditions as described above. As a result, for Sample 2-5 (comparative), it was confirmed that the ferromagnetic layer and the so-called pinned layer were not joined by epitaxial growth.

FIGS. 9A and 9B show the magnetization curve and the MR curve of Sample 2-1 shown in Table 2, respectively. As will be described later, the magnetization curves of Sample 1 in Table 1 (the same as Sample 1 in Table 2) are shown in FIGS. 10A and 10B.

When these are compared, the magnetoresistance effect element 4 having the magnetic multilayer film 2 according to the present invention has a larger MR gradient at the rising portion of the MR curve, and the magnetic field due to the exchange coupling between the antiferromagnetic layer and the ferromagnetic layer. It can be seen that the shift amount Hex is large.

Further, from the results shown in Table 2, the ferromagnetic layer, the non-magnetic metal layer, and the soft magnetic layer were laminated on both sides of the pinned layer in this order. A ferromagnetic layer is epitaxially grown on both sides of the pinned layer and the pinned layer, so that not only the MR change rate and the MR tilt in a DC magnetic field but also the high frequency represented by the MR tilt at 1 MHz, which is the most important in application, is high. It can be seen that the MR characteristics are greatly improved. With this structure, in particular, Sample 2-1
Large high-frequency MR exceeding 0.3% / Oe only in ~ 2-4
Shows the slope.

Further, when the magnetization of the ferromagnetic layer is Mf and the magnetization of the soft magnetic layer is Ms, good high frequency MR characteristics can be obtained when 0.3 ≦ Mf / Ms ≦ 0.8.

Further, Sample 1 in Table 1 and Sample 2-1 in Table 2 were heat-treated at 230 ° C. for 4 hours in a vacuum of 10 ⁻⁵ Torr. Squareness ratio after heat treatment, ρsat, MR change rate,
Table 3 shows the MR gradient in a DC magnetic field and the high-frequency MR gradient.

[0156]

[Table 3] From the results shown in Table 3, there is almost no deterioration in characteristics at the initial stage and after the heat treatment. That is, the magnetoresistive effect element 4 having the magnetic multilayer film 2 shows a large MR gradient in a large DC field exceeding 0.3% / Oe and a large high-frequency MR gradient at 1 MHz.

FIGS. 10A and 10C show the magnetization curves immediately after the formation of the magnetic multilayer film constituting Sample 1 in Table 1 and after the heat treatment, respectively.
3D and 3D show MR curves immediately after the formation of the magnetic multilayer film constituting Sample 1 in Table 1 and after the heat treatment, respectively. FIGS. 11A and 11C show Table 2 respectively.
The magnetization curves immediately after the formation of the magnetic multilayer film constituting Sample 2-1 and after the heat treatment are shown. FIGS. 11B and 11D show the magnetic multilayer films constituting Sample 2-1 in Table 2, respectively. MR curves are shown immediately after film formation and after heat treatment. In sample 2-1, the magnitude of the exchange coupling force above and below the antiferromagnetic layer (pinning layer) is different, so that Hex differs from the upper and lower soft magnetic layers after the heat treatment. However, in both cases, the rising part of the MR curve near zero magnetic field, which is important for application, hardly changes, and it is clear that good MR characteristics are maintained immediately after film formation and after heat treatment. Understand. FIG.
(A) and (B) respectively show sample 2 in Table 2.
2 shows X-ray diffraction curves immediately after film formation and after heat treatment. The diffraction intensity of the (111) -oriented plane from the NiFe and Co layers at around 44 degrees is slightly higher after the heat treatment than immediately after the film formation, but shows that there is essentially no change.

FIG. 13 shows sample 2-1 in Table 2.
Shows the change in MR slope when heat-treating under various pressures. At a temperature of 250 ° C, almost any pressure
Although there is no change in the R slope, at 350 ° C., a difference is caused by the pressure. That is, in the heat treatment in the range where the pressure is lower than 10 ⁻⁷ Torr, the MR gradient keeps a large value.
When the pressure is higher than 0 ^-7 Torr, the MR gradient is deteriorated. This is because the magnetic multilayer film is oxidized by a slight amount of residual oxygen even in a vacuum state. But,
At 450 ° C., the MR gradient deteriorated even under a pressure of 10 ⁻⁹ Torr. Therefore, heat treatment at a pressure lower than 10 ^-7 Torr causes M
It can be seen that the R slope keeps a large value.

Further, in the invention of the magnetoresistive element 4 having the magnetic multilayer film 2 (corresponding to FIG. 4), the specific resistance ρ _p of the pinned layer, the specific resistance ρ _f of the ferromagnetic layer, and the specific resistance ρ _f of the soft magnetic layer An experiment was conducted to examine how the relationship between the three factors and the specific resistance ρ _s affected the characteristics of the multilayer film. That is, magnetic multilayer films (corresponding to FIG. 4) having various lamination compositions as shown in Table 4 below were prepared, and the specific resistances ρ _p , ρ _f , ρ
_s and the value of R * = ρ _p / [(ρ _s + ρ _f ) / 2], and the MR value and MR for each sample.
The slope was measured. The results are shown in Table 4 below. From the results in Table 4, the value of R * = ρ _p / [(ρ _s + ρ _f ) / 2] is 3
30, that is, samples 4-1 to 4-4 satisfying the following equation (1) show good results.

3 ((ρ _f + ρ _s ) / 2) <ρ _p <30 ((ρ _f + ρ _s ) / 2) Equation (1)

[0161]

[Table 4] Next, in order to consider the stacking order of each layer of the magnetoresistive element (corresponding to FIG. 4) having the magnetic multilayer film 2 of the present invention, the stacking order of the magnetic multilayer film 2 (corresponding to FIG. 4) of the present invention is considered. The magnetic multilayer film of Comparative Sample 5-1 was prepared by changing the above. That is, the magnetic multilayer film of the comparative sample 5-1 has a NiFe (70 °) / Cu (30 °) layer on the Ta underlayer (50 °).
Å) / NiFe (70 °) / FeMn (70 °) / Cu
(30 °) / NiFe (70 °) / Cu (30 °) / N
iFe (70 °) / FeMn (70 °) / Cu (50
Å) are sequentially laminated. This is based on the magnetic multilayer film 1 shown in FIG.
0Å) are interposed in two layers in the same lamination order. The MR curve of this comparative sample 5-1 is shown in FIG.
8 is shown.

According to the graph shown in FIG. 18, the sample of Comparative Sample 5-1 has an extremely small MR change rate shown on the vertical axis, and has the opposite effect to the case where the applied magnetic field in the MR curve is increased. 0 in the case of decreasing
The values of the MR change rates near the magnetic field did not match, and it was confirmed that this could not be put to practical use at all. This is because the first ferromagnetic layer NiFe layer and the pinning layer Fe
Even if the Mn layer is joined by epitaxial growth, epitaxial growth is gradually lost as Cu, NiFe, and Cu are stacked again.
This indicates that no epitaxial relationship was obtained between the iFe-FeMn layers. Therefore, in order to pin the ferromagnetic layer most efficiently, ferromagnetic layers are formed above and below the pinned layer as in the magnetic multilayer film 2 (corresponding to FIG. 4) of the present invention, and each is epitaxially grown. Is good.

Further, the following Examples 3 to 6 and Comparative Example 1 will be shown as Examples and Comparative Examples of the invention of the first MR head as the magnetic transducer.

Embodiment 3 Ta was deposited as a metal underlayer to a thickness of 50 ° on an AlTiC (AlTiC) substrate, and NiFe (70
Å) -Cu (30Å) -NiFe (70Å) -FeMn
The layers were laminated in the order of (70 °) to form a magnetic multilayer film. Ni
Fe represents Ni _0.81 Fe _0.19 . The film forming conditions are as follows: ultimate pressure of 2 × 10 ⁻⁷ Torr, pressure at the time of film formation of 1.4 × 10 ⁻⁴ Torr, substrate temperature of about 10 ° C., and 0.2 to 0.3 ° / sec of each material.
The film was formed by the ion beam sputtering method while applying a magnetic field in the plane of the substrate and in the direction parallel to the measurement current during the film formation at the film formation speed of. A junction by epitaxial growth was confirmed between the NiFe-FeMn layers.

Thereafter, a pattern of 20 μm × 6 μm was formed as a magnetically sensitive portion by using photolithography technology, and an electrode having a track width of 3 μm was formed thereon to obtain an MR head. The structure of the manufactured MR head is as shown in FIG. Thereafter, the substrate was cooled from 150 ° C. in a vacuum of 10 ⁻⁵ Torr while applying a magnetic field of 200 Oe in a direction perpendicular to the direction of the measured current and in an in-plane direction, to induce a pinning effect of the ferromagnetic layer. FIG. 14 shows a change in the output voltage when the measurement current is changed in the range of 5 mA, the external magnetic field is set in the range of ± 20 Oe, and 50 Hz. In the MR head using the artificial lattice magnetic multilayer film according to the present invention, an output voltage of about 2.2 mV was obtained.

COMPARATIVE EXAMPLE 1 As a comparative example, a permalloy was manufactured under the same conditions as in Example 3 above, and an MR head utilizing a conventionally used anisotropic magnetoresistance effect was manufactured. The measurement current was 5 mA, the external magnetic field was varied in the range of ± 20 Oe, and 50 Hz. The output voltage at this time was 0.8 mV.

According to Example 3 and Comparative Example 1, the first aspect of the present invention was
With the MR head, an output nearly three times as large as that of the conventional example was obtained. Therefore, the effect of the present invention is clear.

[0168]Example 4 Metal underlayer on AlTiC substrate
Ta was deposited to a thickness of 50 °, and NiFe (70
Å) -Cu (30Å) -NiFe (70Å) -FeMn
(70 °) -NiFe (70 °) -Cu (30 °) -N
iFe (70 °) layers are stacked in order to form a magnetic multilayer film.
Was. The film formation conditions are as follows: ultimate pressure 1.7 × 10^-7Torr, during film formation
Pressure 1.4 × 10^-FourTorr, substrate temperature about 10 ° C, each
Material is deposited at a deposition rate of 0.2-0.3Å / sec during deposition.
Apply a magnetic field in the plane of the substrate and in the direction parallel to the measurement current.
Film formation by ion beam sputtering. That
Later, 10 ^-FiveIn a vacuum of Torr, a plane perpendicular to the direction of the measured current
Cool from 150 ° C while applying a magnetic field of 200 Oe inward
Instead, the pinning effect of the ferromagnetic layer was induced. Other articles
A MR head was manufactured in the same manner as in Example 3 above.
Epitaxial growth on NiFe-FeMn-NiFe
Bonding was confirmed.

The structure of the manufactured MR head is as shown in FIG. FIG. 15 shows a change in the output voltage when the external magnetic field is changed in the range of ± 20 Oe and 50 Hz. In the MR head using the artificial lattice magnetic multilayer film according to the present invention, an output voltage of 3.0 mV was obtained. As compared with Example 3, the resistance between the electrodes was reduced by about 30%. This is because the specific resistance of the magnetic multilayer film has decreased. As for the operation of the MR head, it is more convenient that the specific resistance is smaller because heat generated by the measurement current can be suppressed.

Further, deterioration of the characteristics of the MR head due to heat generation can be suppressed. The effect of the MR head of the present invention was nearly 3.8 times that of the conventional example.

Embodiment 5 FIG. 16 shows an example in which the magnetoresistive element of the present invention is applied to a yoke type MR head. Here, notches are provided in some of the yokes 600 for guiding the magnetic flux, and the magnetoresistive effect element 200 is provided between the notches.
0 is formed. This magnetoresistive element 20
At 0, an electrode (not shown) for flowing a current in a direction parallel or perpendicular to the direction of the magnetic path formed by the yokes 600, 600 is formed. As a result, an output twice as high as that of the MR head using Permalloy was confirmed. Since the magnetic multilayer film of the present invention has good rising characteristics at zero magnetic field, it is not necessary to provide a shunt layer and a bias magnetic field applying means which are generally used.

Embodiment 6 FIG. 17 shows another embodiment when a magnetic transducer, for example, an MR head is formed using the magnetoresistive element of the present invention. The magnetoresistive element 200 is formed in magnetic contact with the high specific resistance flux guide layers 700 and 710. This flash guide layer is formed of the magnetic multilayer film 200.
Since it is made of a material having a specific resistance three times or more larger than that of the magnetic multilayer film 200, the measurement current flowing through the magnetic multilayer film 200 does not substantially flow through the flux guide layers 700 and 710. On the other hand, the flux guide layer 700 and the magnetic multilayer film 20
Since it is magnetically in contact with 0, the signal magnetic field is guided to the flux guide layer 700, and without losing its strength,
The magnetic layer 200 is reached. Reference numeral 600 denotes another flux guide layer, which functions as a return guide for the magnetic flux passing through the magnetic multilayer film 200. The flux guide layer 600 may be provided on both sides of the magnetoresistive effect element 200 and the high specific resistance flux guide layers 700 and 710. Further, the guide layers denoted by reference numerals 710 and 600 may be in contact with each other at an end remote from the medium.
At this time, the MR head using permalloy is 3
Double output was confirmed. In the drawing, reference numeral 400 denotes a non-magnetic insulating layer.

[0173]

As described above, the magnetic multilayer 1
According to the first aspect of the present invention relating to the magnetoresistive element having the above, a magnetoresistive element having an MR gradient of 0.3% / Oe or more is obtained. In addition, the rising characteristics of the MR curve at zero magnetic field are extremely good, and also exhibit high heat resistance. According to the second aspect of the invention relating to the magnetoresistive effect element having the magnetic multilayer film 2, furthermore,
The MR slope at a high frequency of MHz shows a high value of 0.3% / Oe or more, the specific resistance is small, and the property is not deteriorated by heat treatment around 350 ° C. at a pressure of 10 ^-7 Torr or less. Does not occur. In a magnetic transducer using a magnetoresistive element having the magnetic multilayer film 1, for example, an MR head, an output voltage nearly three times as large as that of a conventional material can be obtained. Further, in a magnetic transducer using a magnetoresistive element having the magnetic multilayer film 2, for example, an MR head, the MR gradient in a high frequency region shows a high value of 0.3% / Oe or more, the specific resistance is small, and the 3.8
The output voltage can be doubled. Therefore, it is possible to provide an excellent MR head which is extremely reliable and enables reading of ultra-high density magnetic recording exceeding 1 Gbit / inch ² .

[Brief description of the drawings]

FIG. 1 is a sectional view of a magnetoresistive element according to a first invention.

FIG. 2 is a schematic view of the structure of a magnetoresistive element, particularly a magnetic multilayer film, for explaining the operation of the present invention.

FIG. 3 is a schematic diagram of a magnetization curve and an MR curve for explaining the operation of the present invention.

FIG. 4 is a sectional view of a magnetoresistive element according to a second invention.

FIG. 5 is a partially omitted cross-sectional view showing one example of the magnetic transducer of the present invention.

FIG. 6 is a cross-sectional view showing the structure of a magnetoresistive element (magnetic multilayer film) and an electrode section of the magnetic transducer of the present invention.

FIG. 7 is a sectional view showing another example of the structure of the magnetoresistive element (magnetic multilayer film) and the electrode section of the magnetic transducer of the present invention.

FIG. 8 is an example of an MR curve of a magnetoresistive effect element (magnetic multilayer film) according to the first invention in a DC magnetic field.

FIGS. 9A and 9B are graphs showing a magnetization curve and a MR curve of a magnetoresistive element (magnetic multilayer film) according to the second invention in a DC magnetic field, respectively.

FIGS. 10A and 10C are graphs showing magnetization curves immediately after the film formation and after the heat treatment, respectively, of the magnetoresistive element (magnetic multilayer film) of the first invention, and FIG. ,
(D) is a graph showing the MR curves immediately after the formation of the magnetoresistive element (magnetic multilayer film) of the first invention and after the heat treatment, respectively.

FIGS. 11A and 11C are graphs showing magnetization curves of a magnetoresistive element (magnetic multilayer film) according to the second invention immediately after film formation and after a heat treatment, respectively. ,
(D) is a graph showing an MR curve immediately after the formation of the magnetoresistive element (magnetic multilayer film) of the second invention and after the heat treatment, respectively.

FIGS. 12A and 12B are graphs showing X-ray diffraction patterns immediately after the formation of a magnetoresistive element (magnetic multilayer film) and after a heat treatment, respectively, of the second invention.

FIG. 13 shows the relationship between the MR gradient and the pressure when the magnetoresistive effect element (magnetic multilayer film) of the second invention and the comparative example are heat-treated under various pressures of 250 ° C. to 450 ° C. FIG.

FIG. 14 is a magnetic transducer (MR) according to the first invention;
4 is a chart showing an applied magnetic field and an output voltage of a (head).

FIG. 15 is a magnetic transducer (MR) according to a second invention;
4 is a chart showing an applied magnetic field and an output voltage of a (head).

FIG. 16 is a partially omitted cross-sectional view showing an example in which the magnetoresistive effect element (magnetic multilayer film) of the present invention is applied to a yoke type MR head.

FIG. 17 is a diagram in which the magnetoresistive effect element (magnetic multilayer film) of the present invention is applied to a flux guide type MR head 1
It is a partially-omitted sectional view showing an example.

FIG. 18 shows an MR curve of Comparative Sample 5-1.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Magnetic multilayer film 2 ... Magnetic multilayer film 3 ... Magnetoresistive element 5 ... Base 7 ... Magnetic multilayer unit 10 ... Metal underlayer 20 ... Soft magnetic layer 30 ... Non-magnetic metal layer 40 ... Ferromagnetic layer 50 ... Pinning layer Reference Signs List 60: Interface between ferromagnetic layer and pinning layer 80: Protective layer 90: Recording medium 93: Recording surface 150: Magnetoresistance effect type head 200: Magnetoresistance effect element

Continuation of the front page (51) Int.Cl. ⁷ identification code FI H01L 43/10 G01R 33/06 R (58) Investigation field (Int.Cl. ⁷ , DB name) G11B 5/39 G01R 33/09 H01F 10 / 28 H01F 10/30 H01L 43/08 H01L 43/10

Claims (20)

(57) [Claims] A magnetic transducer including a magnetoresistive element, a conductive film, and an electrode, wherein the conductive film is electrically connected to the magnetoresistive element via the electrode; The magnetoresistive element includes a nonmagnetic metal layer, a ferromagnetic layer formed on one surface of the nonmagnetic metal layer, a soft magnetic layer formed on the other surface of the nonmagnetic metal layer, And a pinned layer formed on the ferromagnetic layer to pin the direction of magnetization of the spin valve , wherein the ferromagnetic layer comprises (Co _z Ni _1-z ) _w Fe _1-w (However,
0.4 ≦ z ≦ 1.0, 0.5 ≦ w ≦ 1.0 by weight
The soft magnetic layer is composed of Co _t M
_u M _'q B _r (however, 0.6 ≦ t ≦ 0.95 in atomic,
0.01 ≦ u ≦ 0.2, 0.01 ≦ q ≦ 0.1, 0.0
5 <r ≦ 0.3; M is at least one selected from Fe and Ni
And M ′ is Zr, Si, Mo, Nb
Represented by at least one selected from the group consisting of:
Where the specific resistance of the pinned layer is ρ _p and the specific resistance of the ferromagnetic layer is
Ρ _f and the specific resistance of the soft magnetic layer as ρ _s ,
Satisfies the following expression (1), and the ferromagnetic layer and the pinning layer are joined by epitaxial growth. _{3 ((ρ f + ρ s} ) / 2) <ρ p <30 ((ρ f + ρ s) / 2) ... formula (1) 2. A magnetic transducer including a magnetoresistive element, a conductive film, and an electrode, wherein the conductive film is electrically connected to the magnetoresistive element via the electrode. The magnetoresistive element includes a nonmagnetic metal layer, a ferromagnetic layer formed on one surface of the nonmagnetic metal layer, a soft magnetic layer formed on the other surface of the nonmagnetic metal layer, And a pinned layer formed on the ferromagnetic layer to pin the direction of magnetization of the spin valve , wherein the ferromagnetic layer comprises (Co _z Ni _1-z ) _w Fe _1-w (However,
0.4 ≦ z ≦ 1.0, 0.5 ≦ w ≦ 1.0 by weight
The soft magnetic layer has a composition represented by (Ni _x
Fe _1-x ) _y Co _1-y (where 0.7 ≦ x ≦ 0.
9, 0.5 ≦ y ≦ 1 . 0).
Ri, the specific resistance [rho _p of the pinned layer, the resistivity of the ferromagnetic layer
Ρ _f and the specific resistance of the soft magnetic layer as ρ _s ,
Satisfies the following expression (1), and the ferromagnetic layer and the pinning layer are joined by epitaxial growth. _{3 ((ρ f + ρ s} ) / 2) <ρ p <30 ((ρ f + ρ s) / 2) ... formula (1) 3. The magnetic transducer according to claim 1, wherein the nonmagnetic metal layer is made of a material containing at least one selected from Au, Ag, and Cu. 4. The magnetoresistance effect element according to claim 1, wherein a gradient of a magnetoresistance change in a 6 Oe width in a high-frequency magnetic field at 1 MHz is 0.2% / Oe or more.
The magnetic transducer according to any one of the above. 5. The magnetic transducer according to claim 1, wherein the magnetic transducer is a magnetoresistive head. 6. The magnetic conversion element according to claim 5, wherein both ends of the magnetoresistive element are joined so that the entire end thereof is in contact with the electrode. 7. A connecting soft magnetic layer is further provided between electrode portions formed at both ends of the magnetoresistive element, and the entirety of the connecting soft magnetic layer and the end of the magnetoresistive element is provided. 7. The magnetic transducer according to claim 6, wherein the magnetic transducers are connected in contact with each other. 8. The connecting soft magnetic layer is continuous between the magnetoresistive element and the electrodes formed at both ends of the magnetoresistive element, and also in contact with the lower surface of the electrode. 8. The magnetic transducer according to claim 7, wherein the magnetic transducer is formed as follows. 9. A magnetic transducer including a magnetoresistive element, a conductor film, and an electrode, wherein the conductor film is electrically connected to the magnetoresistive element through the electrode. The magnetoresistive element has a pinning layer for pinning the magnetization direction of an adjacent ferromagnetic layer, and a pair of ferromagnetic layers, a pair of nonmagnetic metal layers, and a pair of soft layers on both sides of the pinning layer. A magnetic multilayer film of a spin valve having a magnetic multilayer film unit in which magnetic layers are sequentially arranged, wherein the ferromagnetic layer includes (Co _z Ni _1-z ) _w Fe _1-w (where,
0.4 ≦ z ≦ 1.0, 0.5 ≦ w ≦ 1.0 by weight
The soft magnetic layer is composed of Co _t M
_u M _'q B _r (however, 0.6 ≦ t ≦ 0.95 in atomic,
0.01 ≦ u ≦ 0.2, 0.01 ≦ q ≦ 0.1, 0.0
5 <r ≦ 0.3; M is at least one selected from Fe and Ni
And M ′ is Zr, Si, Mo, Nb
Represented by at least one selected from the group consisting of:
Where the specific resistance of the pinned layer is ρ _p and the specific resistance of the ferromagnetic layer is
Ρ _f and the specific resistance of the soft magnetic layer as ρ _s ,
Satisfies the following formula (1), and the ferromagnetic layer and the pinning layer are joined by epitaxial growth. _{3 ((ρ f + ρ s} ) / 2) <ρ p <30 ((ρ f + ρ s) / 2) ... formula (1) 10. A magnetic transducer including a magnetoresistive element, a conductive film, and an electrode, wherein the conductive film is electrically connected to the magnetoresistive element through the electrode. The magnetoresistive element has a pinning layer for pinning the magnetization direction of an adjacent ferromagnetic layer, and a pair of ferromagnetic layers, a pair of nonmagnetic metal layers, and a pair of soft layers on both sides of the pinning layer. A magnetic multilayer film of a spin valve having a magnetic multilayer film unit in which magnetic layers are sequentially arranged, wherein the ferromagnetic layer includes (Co _z Ni _1-z ) _w Fe _1-w (where,
0.4 ≦ z ≦ 1.0, 0.5 ≦ w ≦ 1.0 by weight
The soft magnetic layer has a composition represented by (Ni _x
Fe _1-x ) _y Co _1-y (where 0.7 ≦ x ≦ 0.
9, 0.5 ≦ y ≦ 1.0).
Ri, the specific resistance [rho _p of the pinned layer, the resistivity of the ferromagnetic layer
Ρ _f and the specific resistance of the soft magnetic layer as ρ _s ,
Satisfies the following expression (1), and the ferromagnetic layer and the pinning layer are joined by epitaxial growth. _{3 ((ρ f + ρ s} ) / 2) <ρ p <30 ((ρ f + ρ s) / 2) ... formula (1) 11. The magnetic transducer according to claim 9, wherein the nonmagnetic metal layer is made of a material containing at least one selected from Au, Ag, and Cu. 12. The magnetoresistance effect element according to claim 9, wherein a gradient of a magnetoresistance change in a 6 Oe width in a high-frequency magnetic field at 1 MHz is 0.2% / Oe or more.
2. The magnetic transducer according to claim 1. 13. The magnetic transducer according to claim 9, wherein the magnetic transducer is a magnetoresistive head. 14. The magnetic transducer according to claim 13, wherein both ends of the magnetoresistive element are joined in such a manner that the entire end is in contact with the electrode. 15. A connecting soft magnetic layer is further provided between electrode portions formed at both ends of the magnetoresistive effect element, and the entirety of the connecting soft magnetic layer and the end of the magnetoresistive effect element. The magnetic transducer according to claim 14, wherein the magnetic transducers are connected in contact with each other. 16. The connecting soft magnetic layer is continuous between the magnetoresistive element and electrodes formed at both ends of the magnetoresistive element, and also in contact with the lower surface of the electrode. 16. The magnetic transducer according to claim 15, wherein the magnetic transducer is formed as follows. 17. A non-magnetic metal layer, a ferromagnetic layer formed on one surface of the non-magnetic metal layer, a soft magnetic layer formed on the other surface of the non-magnetic metal layer, A magnetoresistive element comprising a magnetic multilayer film of a spin valve having a pinning layer formed on a ferromagnetic layer to pin the direction of magnetization, wherein the ferromagnetic layer comprises (Co) _z Ni _1-z ) _w Fe _1-w (However,
0.4 ≦ z ≦ 1.0, 0.5 ≦ w ≦ 1.0 by weight
The soft magnetic layer is composed of Co _t M
_u M _'q B _r (however, 0.6 ≦ t ≦ 0.95 in atomic,
0.01 ≦ u ≦ 0.2, 0.01 ≦ q ≦ 0.1, 0.0
5 <r ≦ 0.3; M is at least one selected from Fe and Ni
And M ′ is Zr, Si, Mo, Nb
Represented by at least one selected from the group consisting of:
Where the specific resistance of the pinned layer is ρ _p and the specific resistance of the ferromagnetic layer is
Ρ _f and the specific resistance of the soft magnetic layer as ρ _s ,
Wherein the specific resistance relationship satisfies the following expression (1), and the ferromagnetic layer and the pinning layer are joined by epitaxial growth. _{3 ((ρ f + ρ s} ) / 2) <ρ p <30 ((ρ f + ρ s) / 2) ... formula (1) 18. A non-magnetic metal layer, a ferromagnetic layer formed on one surface of the non-magnetic metal layer, a soft magnetic layer formed on the other surface of the non-magnetic metal layer, A magnetoresistive element comprising a magnetic multilayer film of a spin valve having a pinning layer formed on a ferromagnetic layer to pin the direction of magnetization, wherein the ferromagnetic layer comprises (Co) _z Ni _1-z ) _w Fe _1-w (However,
0.4 ≦ z ≦ 1.0, 0.5 ≦ w ≦ 1.0 by weight
The soft magnetic layer has a composition represented by (Ni _x
Fe _1-x ) _y Co _1-y (where 0.7 ≦ x ≦ 0.
9, 0.5 ≦ y ≦ 1.0).
Ri, the specific resistance [rho _p of the pinned layer, the resistivity of the ferromagnetic layer
Ρ _f and the specific resistance of the soft magnetic layer as ρ _s ,
Wherein the specific resistance relationship satisfies the following expression (1), and the ferromagnetic layer and the pinning layer are joined by epitaxial growth. _{3 ((ρ f + ρ s} ) / 2) <ρ p <30 ((ρ f + ρ s) / 2) ... formula (1) 19. A pinning layer for pinning the direction of magnetization of an adjacent ferromagnetic layer, and a pair of ferromagnetic layers, a pair of non-magnetic metal layers, and a pair of soft magnetic layers on both sides of the pinning layer. A magnetoresistive effect element comprising a magnetic multilayer film of a spin valve having a magnetic multilayer unit in which layers are sequentially arranged, wherein the ferromagnetic layer comprises (Co _z Ni _{1 -z} ) _w Fe _{1- w} (however,
0.4 ≦ z ≦ 1.0, 0.5 ≦ w ≦ 1.0 by weight
The soft magnetic layer is composed of Co _t M
_u M _'q B _r (however, 0.6 ≦ t ≦ 0.95 in atomic,
0.01 ≦ u ≦ 0.2, 0.01 ≦ q ≦ 0.1, 0.0
5 <r ≦ 0.3; M is at least one selected from Fe and Ni
And M ′ is Zr, Si, Mo, Nb
Represented by at least one selected from the group consisting of:
Where the specific resistance of the pinned layer is ρ _p and the specific resistance of the ferromagnetic layer is
Ρ _f and the specific resistance of the soft magnetic layer as ρ _s ,
Wherein the specific resistance relationship satisfies the following expression (1), and the ferromagnetic layer and the pinning layer are joined by epitaxial growth. _{3 ((ρ f + ρ s} ) / 2) <ρ p <30 ((ρ f + ρ s) / 2) ... formula (1) 20. A pinning layer for pinning the direction of magnetization of an adjacent ferromagnetic layer, and a pair of ferromagnetic layers, a pair of nonmagnetic metal layers, and a pair of soft magnetic layers on both sides of the pinning layer. A magnetoresistive effect element comprising a magnetic multilayer film of a spin valve having a magnetic multilayer unit in which layers are sequentially arranged, wherein the ferromagnetic layer comprises (Co _z Ni _{1 -z} ) _w Fe _{1- w} (however,
0.4 ≦ z ≦ 1.0, 0.5 ≦ w ≦ 1.0 by weight
The soft magnetic layer has a composition represented by (Ni _x
Fe _1-x ) _y Co _1-y (where 0.7 ≦ x ≦ 0.
9, 0.5 ≦ y ≦ 1.0).
Ri, the specific resistance [rho _p of the pinned layer, the resistivity of the ferromagnetic layer
Ρ _f and the specific resistance of the soft magnetic layer as ρ _s ,
Wherein the specific resistance relationship satisfies the following expression (1), and the ferromagnetic layer and the pinning layer are joined by epitaxial growth. _{3 ((ρ f + ρ s} ) / 2) <ρ p <30 ((ρ f + ρ s) / 2) ... formula (1)