JPH0887722A - Magneto-resistive element and magnetic conversion element - Google Patents

Abstract

PURPOSE: To obtain a large optical voltage by joining a ferromagnetic layer and a pinning layer by epitaxial growth. CONSTITUTION: This magneto-resist resistive element 3 has multilayered artificial lattice magnetic films 1. These multilayered films have a nonmagnetic metallic layer 30 and a ferromagnetic layer 40 formed on one surface of this nonferromagnetic metallic layer 30. Further, the element has the laminate structure having the soft magnetic layer 10 formed on the other surface of the metallic layer 30 and the pinning layer 50 formed on the ferromagnetic layer 40 in order to pin the direction of the magnetization of the ferromagnetic layer 40. The multilayered films are thus formed on the laminate substrate 5 and a metallic ground surface layer 10 is interposed between the substrate 5 and the soft magnetic layer 20. A protective layer 80 is formed on the pinning layer 50. The multilayered films 1 are formed in the state that the ferromagnetic layer 40 and the pinning layer 50 are joined by epitaxial growth in such a manner. The ferromagnetic layer 40 is formed to a thickness of 20 to 100Å, more preferably 20 to 60Å. The pinning force from the pinning layer 50 diminishes if the thickness exceeds 100Å.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetoresistive effect element for reading a magnetic field strength of a magnetic recording medium or the like as a signal, which can read a particularly small magnetic field change as a large electric resistance change signal. and,
The present invention relates to a magnetic transducer element such as a magnetoresistive head.

[0002]

2. Description of the Related Art In recent years, magnetic sensors have been made highly sensitive and magnetic recording has been made highly dense, and accordingly, magnetoresistive effect type magnetic sensors (hereinafter referred to as MR
It is called a sensor. ) Or a magnetoresistive effect type magnetic head (hereinafter referred to as an MR head) is being actively developed. Both the MR sensor and the MR head read the external magnetic field signal by the resistance change of the reading sensor section using a magnetic material. However, in the MR sensor and the MR head, the relative speed with the recording medium does not depend on the reproduction output. From MR
The sensor has a high sensitivity, and the MR head has a feature that a high output can be obtained even when reading a signal of high density magnetic recording.

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

By the way, an artificial lattice having a structure in which thin films having a thickness on the order of atomic diameter of metal are periodically laminated has attracted attention in recent years because it exhibits characteristics different from those of bulk metal. As one type of such 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. Until now, magnetic multilayers of iron-chromium type, cobalt-copper type, etc. have been known. Membranes are known. Of these, for the iron-chromium type (Fe / Cr), ultra low temperature (4.2
It has been reported that the magnetic resistance change exceeds 40% in (K) (Phys. Review Letters (Phys.
Rev. Lett) 61, 2472, 1988). However, in this artificial lattice magnetic multilayer film, the external magnetic field (operating magnetic field strength) at which the maximum resistance change occurs is as large as ten dozen kOe to several dozen kOe, and it is not practical as it is. Besides this, Co / Ag
Artificial lattice magnetic multi-layered films have been proposed, but the operating magnetic field strength of these films is too large.

Under the circumstances, a new structure called a spin valve film has been proposed. In this, two NiFe layers are formed via a non-magnetic layer, and one of the NFe layers is formed.
The 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 this NiFe layer is fixed up to the magnetic field strength of several tens to several hundreds Oe. The spin of one NiFe layer can freely change its direction by an external magnetic field. As a result, NiF
A magnetoresistance change rate (MR change rate) of 2 to 5% can be realized in a small magnetic field range of about the coercive force of the e layer. Other,
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)
It is stated that the MR change rate sharply rises to 5.0% with an applied magnetic field of 10 Oe in [the thickness of each layer (Å) in the parentheses, the same applies below].

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

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

D. Japanese Journal of Applied Physics
Physics), 32 (1993) L1441 The MR change rate when the structure of a and b is a multilayer structure is described. The multilayer structure here is NiFe
(60) / Cu (25) / NiFe (40) / FeMn
The structure of (50) is laminated with Cu in between.

Further, the following publications have been published.

E. Japanese Unexamined Patent Publication No. 2-61572 (US Pat. No. 4,949,039) describes that a ferromagnetic thin film laminated via a non-magnetic intermediate layer exhibits a large MR effect by forming antiparallel arrangement between the layers. . It also describes a structure in which an antiferromagnetic material is adjacent to one of the ferromagnetic layers.

F. SUMMARY OF THE INVENTION A magnetic recording / reproducing device using a spin valve film is described. In particular, it discloses that 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 less magnitude of change rate abruptly MR curve in the following of the applied magnetic field number 10Oe has changed, 1~10Gbit / inch ²
It is suitable as an MR head material for higher recording density. However, the contents disclosed in these documents and gazettes only show the basic operation of the spin valve film.

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

As a means for solving such a characteristic, N
With 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 this shunt layer, a soft film bias layer made of a soft magnetic material having a large specific resistance such as CoZrMo, NiFeRh is provided to apply a bias magnetic field. However, the structure having such a bias layer complicates the process, makes it difficult to stabilize the characteristics, and causes an increase in cost.
Further, since the gentle portion of the MR change curve generated as a result of shifting the MR curve is used, the MR slope in the unit magnetic field is as small as about 0.05% / Oe, which causes a decrease in S / N and the like. It is insufficient as an MR head material for recording densities higher than 10 Gbit / inch ² .

Furthermore, MR heads and the like have a complicated laminated structure and require heat treatment such as baking and curing of the resist material in the steps of patterning, flattening, etc.
Some heat resistance may be required. However, in the conventional artificial lattice magnetic multilayer film, the characteristics are deteriorated by such heat treatment.

In the conventional spin valve film disclosed in the literature, etc., only the basic structure and basic characteristics of the thin film have been discussed, and an MR head structure for realizing super high density magnetic recording and a suitable structure for the MR head structure are suitable. There was no mention of the magnetic multilayer structure.

As described above, in the examples shown in these documents, when these thin films are actually applied as an MR head, the MR gradient in the actual magnetic field detection range is small and M
As an R head, good and stable reproduction cannot be performed. Further, as an excellent MR head material in super high density magnetic recording, an MR change curve up to an applied magnetic field of -10 to 10 Oe is also important. However, in the disclosed examples of these documents, there is no detailed discussion of the MR slope in this range.

Furthermore, the MR head is required to be used under a high frequency magnetic field of 1 MHz or more for high density recording / reproduction. However, in the film thickness structure of various conventional ternary magnetic multilayer films, 10 Oe in a high frequency magnetic field of 1 MHz or more is used.
Slope of magnetoresistance change curve in width (MR slope at high frequency)
Is 0.2% / Oe or more, it is difficult to obtain high high frequency sensitivity.

[0020]

SUMMARY OF THE INVENTION The present invention was devised in such an actual situation, and its purpose is to exhibit a large MR change rate and an applied magnetic field of, for example, -10 to 10 Oe.
Shows a linear rise characteristic of MR change in a very small range, high magnetic field sensitivity, and MR in high frequency magnetic field
It is an object of the present invention to provide a magnetoresistive effect element including a magnetic multilayer film having a large inclination and a high heat resistant temperature, and a magnetic conversion element such as a magnetoresistive effect head using the magnetoresistive effect element.

[0021]

In order to solve such a problem, the present invention provides a magnetoresistive effect element, a conductor film, and
A magnetic conversion element including an electrode part, wherein the conductor film is
The magnetoresistive effect element is electrically connected to the magnetoresistive effect element through the electrode portion, and the magnetoresistive 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 pinning layer formed on the ferromagnetic layer for pinning the magnetization direction of the ferromagnetic layer. The ferromagnetic layer and the pinned layer are configured to be joined by epitaxial growth.

In a preferred aspect of the present invention, the pinning layer is an antiferromagnetic layer, a hard magnetic layer, a pinning ferromagnetic layer made of a material different from the ferromagnetic layer connected to the pinning layer, and It is configured to be at least one selected from layers in which artificial structural defects are 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 and 0.5 ≦ w by weight). ≦ 1.0), and the soft magnetic layer is (Ni _x Fe
_1-x ) _y Co _1-y (however, 0.7 ≦ x ≦ 0.
9, 0.5 ≦ y ≦ 1.0).

In a preferred embodiment of the present invention, the ferromagnetic layer is (Co _z Ni _1-z ) _w Fe _1-w (where, by weight, 0.4 ≦ z ≦ 1.0, 0.5 ≦ w). ≦ 1.0), and the soft magnetic layer is made of Co _t M _u M ′ _q.
B _r (provided that the number of atoms is 0.6 ≦ t ≦ 0.95, 0.01
≦ u ≦ 0.2, 0.01 ≦ q ≦ 0.1, 0.05 ≦ r ≦
0.3; M is at least one selected from Fe and Ni, and M ′ is at least one selected from Zr, Si, Mo, and Nb). Is configured as follows.

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

In a preferred embodiment of the present invention, the hard magnetic layer forming the pinning layer is made of one kind of metal selected from Fe, Co and Ni, or Fe, C.
50 wt% of one metal selected from o and Ni
It is composed of an alloy containing the above.

In a preferred embodiment of the present invention, the antiferromagnetic layer forming the pinned layer is Fe, Ni, Co, Cr,
It is composed of a material containing at least two kinds selected from Mn, Ru, Rh, Mo, and O.

In a preferred embodiment of the present invention, the ferromagnetic layer and the soft magnetic layer have a thickness of 20 to 100, respectively.
Configured to be Å.

In a preferred embodiment of the present invention, the ferromagnetic layer has a thickness of 20 to 60Å and the soft magnetic layer has a thickness of 40.
Is configured to be ~ 100Å.

In a preferred aspect of the present invention, the thickness of the nonmagnetic metal layer is 20 to 60Å.

According to a preferred aspect of the present invention, the pinning layer has a thickness of 50 to 700Å.

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 , these ratios are given. 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) In a preferred embodiment of the present invention, the magnetoresistive element is:
The gradient of the magnetoresistance change in the width of 6 Oe in the high frequency magnetic field of 1 MHz is 0.2% / Oe or more.

According to a preferred aspect of the present invention, the magnetic conversion element is a magnetoresistive head.

As a preferred aspect of the present invention, both ends of the magnetoresistive effect element are configured to be joined in a state in which the entire ends are in contact with the electrode portion.

As a preferred embodiment of the present invention, a soft magnetic layer for connection is further provided between the electrode portions formed at both ends of the magnetoresistive effect element, and the soft magnetic layer for connection and the magnetoresistive effect are provided. The ends of the elements are configured to be connected in contact with each other.

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

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

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

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

In a preferred embodiment of the present invention, the ferromagnetic layer is (Co _z Ni _1-z ) _w Fe _1-w (where, by weight, 0.4 ≦ z ≦ 1.0, 0.5 ≦ w). ≦ 1.0), and the soft magnetic layer is (Ni _x Fe
_1-x ) _y Co _1-y (however, 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, by weight, 0.4 ≦ z ≦ 1.0, 0.5 ≦ w). ≦ 1.0), and the soft magnetic layer is made of Co _t M _u M ′ _q.
B _r (provided that the number of atoms is 0.6 ≦ t ≦ 0.95, 0.01
≦ u ≦ 0.2, 0.01 ≦ q ≦ 0.1, 0.05 ≦ r ≦
0.3; M is at least one selected from Fe and Ni, and M ′ is at least one selected from Zr, Si, Mo, and Nb). Is configured as follows.

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

In a preferred embodiment of the present invention, the hard magnetic layer forming the pinning layer is made of one metal selected from Fe, Co and Ni, or Fe, C.
50 wt% of one metal selected from o and Ni
It is composed of an alloy containing the above.

In a preferred embodiment of the present invention, the antiferromagnetic layer forming the pinned layer is Fe, Ni, Co, Cr,
It is composed of a material containing at least two kinds selected from Mn, Ru, Rh, Mo, and O.

In a preferred embodiment of the present invention, the ferromagnetic layer and the soft magnetic layer have a thickness of 20 to 100, respectively.
Configured to be Å.

In a preferred embodiment of the present invention, the ferromagnetic layer has a thickness of 20 to 60Å and the soft magnetic layer has a thickness of 40.
Is configured to be ~ 100Å.

In a preferred aspect of the present invention, the thickness of the nonmagnetic metal layer is 20 to 60Å.

In a preferred aspect of the present invention, the pinning layer has a thickness of 50 to 700Å.

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 , these ratios are given. 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) In a preferred embodiment of the present invention, the magnetoresistive element is:
The gradient of the change in magnetoresistance in a width of 6 Oe in a high frequency magnetic field of 1 MHz is 0.2% / Oe or more.

In a preferred aspect of the present invention, the magnetic conversion element is configured to be a magnetoresistive head.

As a preferred aspect of the present invention, both ends of the magnetoresistive effect element are joined so that the entire ends thereof are in contact with the electrode portions.

As a preferred embodiment of the present invention, a soft magnetic layer for connection is further provided between the electrode portions formed on both ends of the magnetoresistive effect element, and the soft magnetic layer for connection and the magnetoresistive effect are provided. It is configured so that the entire ends of the elements are connected in contact.

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

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

In 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 in-plane direction of the film in the same direction as the signal magnetic field during film formation. The soft magnetic layer is formed by applying an external magnetic field of 10 to 300 Oe perpendicular to the signal magnetic field direction and in the film in-plane direction during the 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 effect element comprising a magnetic multilayer film having a pinning layer formed on a ferromagnetic layer for pinning the magnetization direction of the ferromagnetic layer, the ferromagnetic layer and the pinning The layer is configured to be joined by epitaxial growth.

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 , these ratios are given. 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, a 6 Oe width in a high frequency magnetic field at 1 MHz. Slope of magnetic resistance change at 0.2% / O
e or more.

Further, according to the present invention, 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 nonmagnetic metal layers on both sides of the pinning layer, respectively. A magnetoresistive effect element comprising a magnetic multi-layer film having a magnetic multi-layer film unit in which a pair of soft magnetic layers are sequentially arranged, wherein the ferromagnetic layer and the pinned layer are joined by epitaxial growth. 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 , these ratios are given. 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, a 6 Oe width in a high frequency magnetic field at 1 MHz. Slope of magnetic resistance change at 0.2% / O
e or more.

According to the invention relating to the above-mentioned first magnetoresistive effect element, a magnetic multilayer film having a resistance change rate of MR gradient of 0.3% / Oe or more can be obtained. Moreover, MR at 0 magnetic field
The rising characteristics of the curve are extremely good and show high heat resistance. In addition, in the invention relating to the second magnetoresistive effect element, in addition, the MR slope 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 of 10 ^-7 Torr or less is used. It is possible to obtain a magnetic multilayer film having high heat resistance which does not cause deterioration of characteristics even when heat-treated at about 350 ° C. According to the invention relating to the first magnetic conversion element having the first magnetoresistive effect element, it is possible to obtain an output voltage nearly three times as large as that of the conventional material. Further, according to the invention relating to the second magnetic conversion element having the second first magnetoresistance effect, the MR in the high frequency region is
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 higher. Therefore, it is possible to provide a highly reliable magnetic conversion element such as an MR head that enables reading of ultra-high density magnetic recording exceeding 1 Gbit / inch ² with extremely high reliability.

[0065]

BEST MODE FOR CARRYING OUT THE INVENTION The specific constitution of the present invention will be described in detail below.

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

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

In the present invention, depending on the direction of the signal magnetic field applied from the outside, the mutual magnetization of the soft magnetic layer 20 and the ferromagnetic layer 40, which are formed on both sides of the non-magnetic metal layer 30 and adjacent to each other, are set. It is necessary that the orientation be substantially different. The reason is that, according to the principle of the present invention, when the magnetization directions of the soft magnetic layer 20 and the ferromagnetic layer 40 formed via the nonmagnetic metal layer 30 are deviated, conduction electrons are subjected to spin-dependent scattering. ,
When the resistance increases and the magnetization directions are opposite to each other,
This is because it has the maximum resistance. That is, in the present invention, as shown in FIG. 2, when the signal magnetic field from the outside is positive (upward from the recording surface 93 of the recording medium 90 (represented by reference numeral 92), the magnetic layers adjacent to each other are The components in which the directions of magnetization are opposite to each other are generated, and the resistance increases.

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

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 most likely to exist via one nonmagnetic 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 downward toward the medium surface by the method described later (reference numeral 41). Since the other soft magnetic layer 20 is formed via the non-magnetic metal layer 30, its magnetization direction is changed by a signal magnetic field from the outside (reference numeral 21). At this time, the relative angle of magnetization of the soft magnetic layer 20 and the ferromagnetic layer 40 largely changes depending on the direction of the signal magnetic field from the magnetic recording medium 90. As a result, the degree of scattering of conduction electrons flowing in the magnetic layer changes, and the electric resistance changes significantly.

As a result, a large MR whose mechanism is essentially different from the anisotropic magnetoresistive effect of the usual 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 relative to the external magnetic field. The change in the direction of those magnetizations is shown in FIG. 3 corresponding to the magnetization curve and the MR curve. Here, the pinning layer 50 fixes all the magnetizations of the ferromagnetic layer 40 in the minus direction (downward from the recording surface of the recording medium 90). When the external signal magnetic field is negative, the magnetization of the soft magnetic layer 20 also faces the negative direction. Now, in order to simplify the explanation, the coercive forces of the soft magnetic layer 20 and the ferromagnetic layer 40 are set to values 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 increased 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. As it becomes, 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 working by the pinning layer 50. When the signal magnetic field exceeds this 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 respective magnetization directions of 0 are aligned in one direction. At this time, the magnetization becomes a certain constant value and the MR curve becomes zero.

On the contrary, when the signal magnetic field H decreases, the regions (III) to (II) and (I) are sequentially changed with the magnetization reversal of the soft magnetic layer 20 and the ferromagnetic layer 40 as before. To do.
Here, in the first part of the region (II), the conduction electrons undergo the spin-dependent scattering, and the resistance increases. Area (II)
Among them, the ferromagnetic layer 40 is pinned, so that the magnetization is hardly inverted. However, since the soft magnetic layer 20 linearly increases its magnetization, it corresponds to the magnetization change of the soft magnetic layer 20 and depends on the spin. The proportion of conduction electrons that undergo the scattered scattering gradually increases. That is, for example, Hc is added to the soft magnetic layer 20.
Of Ni _0.8 Fe _0.2 with a small
By adding k, the number Oe to several 10 below Hk can be obtained.
It is possible to obtain a magnetic multilayer film in which the resistance change is linear and the resistance change rate is large under a small external magnetic field in the range of Oe.

In the present invention, the film thickness of each thin film layer has its own constraint value. If the layer thickness of the non-magnetic metal layer becomes thicker than this limit value, the ratio of conduction electrons flowing only in this layer increases, and the MR change of the whole becomes small, which is inconvenient. On the other hand, since the conduction electrons are scattered at the interface between the non-magnetic metal layer and the soft magnetic layer 20 and the ferromagnetic layer 40, the two magnetic layers 20 and 40 have a thickness of 10
Even if it is thicker than 0Å, there is no substantial improvement in the effect. Rather, it is not convenient because the entire film thickness becomes thick. The lower limit of the thickness of the two magnetic layers 20 and 40 is preferably 20 Å or more. If it is thinner than this, heat resistance and working resistance deteriorate.

The respective structures of the above-mentioned first magnetic multilayer film will be described below in detail. The first characteristic of this multilayer film is that the ferromagnetic layer 40 and the pinning layer 50 are laminated by epitaxy. That is, the ferromagnetic layer 40 and the pinning layer 50 are formed in a state of being joined by epitaxial growth.

Epitaxy is a term that represents the phenomenon of crystal growth between layers, and in the present invention, there are atoms in both the pinning layer 50 and the ferromagnetic layer 40 formed in contact with it. It is a state in which the layers are formed along the crystallographically oriented surface with a certain degree of cleanness, and each of these layers has a crystallographic relationship. In the present invention, the formed magnetic multilayer film is cut in the stacking direction and the cross section of the stack is observed with a high resolution electron microscope (TEM). And
When the insides of the ferromagnetic layer 40 and the pinning layer 50 are observed and crystal lattice fringes are confirmed, it is understood that the crystal orientations of the layers are uniform. The orientation plane can also be identified from the distance. Next, the interface portion between the pinned layer 50 and the ferromagnetic layer 40 is observed in detail, and if the interference stripes of each layer are connected at the interface portion, epitaxy (epitax
y) Judge that the relationship exists.

As described above, in the present invention, the ferromagnetic layer 40 is
First, it is an important requirement that the pinning layer 50 and the pinning layer 50 are bonded by epitaxial growth.
If these layers 40 and 50 are not formed by epitaxial growth, the pinning effect of the pinned layer 50 on the ferromagnetic layer 40 is diminished, and as a result, the soft magnetic layer 20 and the ferromagnetic layer 40 are separated from each other. Since a relative angle does not occur between 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
It is composed of d etc. and alloys and compounds containing these elements, but in particular (Co _z Ni _1-z ) _w Fe _1-w (however, 0.4 ≦ z ≦ 1.0, 0.5 by weight). ≦ w ≦ 1.0)
The composition is preferably represented by If the composition is out of these ranges, there is a disadvantage that a large change in electric resistance cannot be obtained.

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

The pinning layer 50 may be formed by any method as long as the magnetization of the adjacent magnetic layers is fixed. In particular, the ferromagnetic layer connected to the antiferromagnetic layer, the hard magnetic layer or the pinning layer is used. It is selected from a pinning ferromagnetic layer made of a material different from 40, and a layer having artificial structural defects introduced therein.

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

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

Further, as the ferromagnetic layers made of different materials, 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,
Co-based amorphous alloy, MnSb, NiMn, ferrite and the like are preferable.

A similar pinning effect can be obtained by artificially introducing a structural defect in the interface portion of the ferromagnetic layer 40 facing the pinning layer 50. After forming the ferromagnetic layer 40, the surface of the ferromagnetic layer 40 is weakly irradiated with an ion current of 10 to 50 mA and an accelerating voltage of 100 to 500 eV by a weak ion beam of 2 to 20 mA.
It is obtained by etching the ferromagnetic layer 40 to about Å. At this time, the magnetization of the ferromagnetic layer 40 is pinned by the introduced structural defect in the interface portion, and the same effect as other methods is obtained.

By these methods, the adjacent ferromagnetic layer 4
0 and the pinning layer 50 are in direct contact with each other,
Direct interlayer interaction acts on both of them, and the magnetization rotation of the ferromagnetic layer 40 is blocked. On the other hand, the soft magnetic layer 20, which will be described later in detail,
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 0, and a large MR effect resulting from the difference in the direction of the magnetization is obtained.

The thickness of the pinning layer 50 is preferably 50 to 700Å. If this value is less than 50Å, the crystallinity of the pinning layer is poor and the pinning effect cannot be sufficiently obtained. As a result, a large MR effect cannot be obtained. If this value exceeds 700Å, the thickness of the entire magnetic multilayer film becomes too thick, and the resistance of the entire film increases. As a result, the MR change rate is reduced. In addition, the shield layer becomes thick, 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 preferable result is obtained. Particularly preferably a composition represented by _{(Ni x Fe 1-x)} y Co 1-y ( however, 0.7 ≦ x ≦ 0.9,0.5 ≦ y ≦ 1.0 by weight). Here, when x and y are in this range, Hc becomes small and favorable soft magnetic characteristics are obtained, and as a result, favorable MR characteristics with high magnetic field sensitivity can be obtained. On the other hand, if x and y deviate from this range, Hc becomes large, and the MR characteristic with high magnetic field sensitivity cannot be obtained.

Further, as the composition of the soft magnetic layer 20,
Co _t M _{u M'q} B _r (where 0.6 ≦ t ≦
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 and S.
Represents at least one selected from i, Mo, and Nb. When M and M ′ are two or more, the total amount of the two or more should be within the above composition range. Since such a composition has a large content of Co, it has an extremely excellent characteristic that the MR change rate becomes larger than that of the previous composition. Further, as its crystal structure, a collection of ultrafine crystal grains or an amorphous structure shows better soft magnetic characteristics, and as a result, a large MR gradient can be obtained. Specific examples of these compositions include Co as a main component and Ni.
And / or Fe is selected as the content such that the magnetostriction becomes zero. Zr, Si, Mo, Nb or the like 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 convenient to add Fe or Ni in a small amount because the characteristics as a soft magnetic material are improved. The content ratio of M ′ is 0.01 ≦ q ≦ 0.1, and if q is less than 0.01, the effect due to the addition cannot be obtained. When q exceeds 0.1, the characteristics as a soft magnetic material deteriorate. B (boron) is a main element for amorphization, and its content ratio is 0.05 ≦.
r ≦ 0.3. If r is less than 0.05, the effect due to the addition cannot be obtained. If r exceeds 0.3, the characteristics as a soft magnetic material deteriorate.

The thickness of such a soft magnetic layer 20 is 20 to 20.
It is set to 100Å, preferably 40 to 100Å, and more preferably 50 to 80Å. If this value is less than 20Å, good characteristics as a soft magnetic layer cannot be obtained. On the other hand, if this value exceeds 100Å, the overall thickness of the multilayer film increases, and the resistance of the entire magnetic multilayer film increases,
The MR effect is reduced.

The soft magnetic layer 20 and the ferromagnetic layer 4
It is desirable that the non-magnetic metal layer 30 interposed between 0 and 0 be a conductive metal in order to efficiently guide electrons. More specifically, at least one selected from Au, Ag, and Cu or at least one selected from these is 6
Examples thereof include alloys containing 0 wt% or more.

The thickness of such a non-magnetic metal layer 30 is 2
It is preferably 0 to 60Å. When this value is 20 Å or less, the soft magnetic layer 2 arranged through this
0 and the ferromagnetic layer 40 are exchange-coupled with each other, and the soft magnetic layer 2
There is a problem that the spins of 0 and the ferromagnetic layer 40 do not function independently. This value is 60Å
Above, the soft magnetic layer 20 and the ferromagnetic layer 4 located above and below
The ratio of electrons scattered at the 0 interface causes a phenomenon, and M
There is an inconvenience that the R change rate decreases.

In the relationship among 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 _p .
_{When f 1} and the specific resistance of the soft magnetic layer 20 are ρ _s , it is preferable that the specific resistance relationship satisfies the following formula (1).

3 ((ρ _f + ρ _s ) / 2) <ρ _p <30 ((ρ _f + ρ _s ) / 2) ... Equation (1) When the value of this ρ _p is equal to or lower than the lower limit of Equation (1), The inconvenience arises that the electron paths are not effectively separated. This ρ
_If the value of _p is greater than or equal to the upper limit of 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, alloys thereof, or the like 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 said to be about 0Å.

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

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

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

The magnetic multilayer film 2 included in the magnetoresistive effect element 4 of the second embodiment has a pinning layer 5 as shown in FIG.
On both sides of 0, a pair of ferromagnetic layers 40, 40, a pair of nonmagnetic metal layers 30, 30 and a pair of soft magnetic layers 20, respectively.
It has a magnetic multilayer unit 7 in which 20 are sequentially arranged. In the case of this embodiment, this unit 7 is formed on the substrate 5 via the metal underlayer 10 as shown.
Further, as shown in the figure, a protective layer 80 is formed on the upper soft magnetic layer 20. Further, a nonmagnetic metal layer may be formed between the metal underlayer film 10 and the soft magnetic layer 20. In FIG. 4, the members having the same reference numerals (FIG. 1) used in the description of the magnetic multilayer film 1 mean the same members and have the same basic operation.

The inventors further conducted research on the film structure of the magnetic multilayer film 1 (FIG. 1) included in the magnetoresistive effect element 3 of the first embodiment, and as a result, obtained a large MR effect. It was 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. And this spin does not change its magnitude with an external signal magnetic field. On the other hand, the magnetic multilayer film of the present invention exhibits a large change in magnetic resistance 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 soft magnetic layers 20 in which spins freely rotate may be larger than the number of pinning layers 50. That is, as shown in FIG. 4, the ferromagnetic layer 4 is formed on both sides of the pinning layer 50 as a center.
By forming the soft magnetic layers 20 and 20 via the 0 and 40 and the non-magnetic metal layers 30 and 30, the magnetic multilayer film 2 (magnetoresistive effect element 4) in which the magnetoresistive effect is greatly improved can be manufactured. it can.

The ferromagnetic layer 40, the non-magnetic metal layer 30, the soft magnetic layer 20, and the pinning layer 50 are 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. Also in such a magnetic multilayer film 2, the pinning layer 50 and the pair of ferromagnetic layers 40 formed on both sides of the pinning layer 50 need to be joined by epitaxial growth.

The spins of both the ferromagnetic layers 40, 40 and the soft magnetic layers 20, 20 contribute to the scattering of conduction electrons. In order for the scattering to occur most efficiently, the spin magnitudes of the two are almost the same. That is, it is basically preferable that the magnetization amounts of the respective layers are substantially the same.
However, in the case of the magnetic multilayer film 2 of the second embodiment, since the ferromagnetic layers 40, 40 have a structure formed on both sides of the pinning layer 50, considering one ferromagnetic layer 40, When the magnetization of the ferromagnetic layer 40 is smaller than that of the soft magnetic layer 20, scattering is performed more efficiently. If the ferromagnetic layer 40 is too thick, the magnetization of the layer 40 as a whole becomes larger than the magnetization of the soft magnetic layer 20, so if the thickness of the ferromagnetic layer 40 is set so that they have almost the same value. 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 ≦ 0.8 Ms, preferably 0.4 Ms ≦ Mf
Each of layers 20 and 4 such that ≦ 0.7 Ms
When the thickness of 0 is adjusted, 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. Further, at least when the soft magnetic layer 20 is formed, an external magnetic field is applied in one direction in the film plane, which will be described later, to obtain an anisotropic magnetic field Hk. 3 to 20 Oe, more preferably 3 to 16 Oe, especially 3
It is preferable to add ~ 12 Oe. As a result, the magnetic multilayer film 2 (magnetoresistive element 4) thus formed has an MR slope of 0.3% / in the rising portion of the MR change curve.
Oe or more, especially 0.4% / Oe or more, usually 0.4 to 1.0%
/ Oe is obtained. The maximum hysteresis width of the MR change curve is 8 Oe or less, usually 0 to 6 Oe. Besides,
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% /
It can be set to Oe, and sufficient performance can be obtained when used for an MR head for reading high density recording.
In the magnetic multilayer film 1 (magnetoresistive element 3) of the first embodiment, the soft magnetic layer 20 should preferably be treated in the same manner. When the anisotropic magnetic field Hk of the soft magnetic layer is less than 3 Oe, the coercive force is almost the same, and a linear MR change curve centering on the 0 magnetic field cannot be obtained substantially. The characteristics deteriorate. On the other hand, if it is larger than 20 Oe, the MR inclination becomes small, and when this film is applied to an MR head or the like, the output tends to decrease and the resolution also decreases. Here, these Hk are obtained by applying a magnetic field of 10 to 300 Oe as an external magnetic field during film formation. If the external magnetic field is 10 Oe or less, it is not enough to induce Hk, and if it exceeds 300 Oe, the effect does not change,
The coil for generating the magnetic field becomes large, which is expensive and inefficient.

The MR change rate is expressed by the maximum resistivity ρmax
, And the minimum specific resistance is ρsat, (ρmax − ρsat
) × 100 / ρsat (%). The maximum hysteresis width is the magnetic resistance change curve (MR curve).
Is the maximum value of the hysteresis width calculated by measuring. Furthermore, 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 slope is the MR slope when the MR change rate is measured with an alternating magnetic field having a magnetic field width of 1 MHz 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 effect element. The number n of repeated laminations of the magnetic multilayer film is not particularly limited and may be appropriately selected according to the target magnetoresistance change rate and 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 is, the better. However, when the thickness is reduced, the MR effect is usually reduced at the same time, but the magnetic multilayer film used in the present invention can provide a multilayer film that can be practically used even when the number n of repeated laminations is 1. Further, as the number of laminated layers increases, the rate of change in resistance also increases, but productivity deteriorates. Further, if n is too large, the resistance of the entire device becomes too low, which causes practical inconvenience. Is preferably 10 or less.
The long-period structure of the artificial lattice can be confirmed by the appearance of primary and secondary peaks according to the repeating period in a small-angle X-ray diffraction pattern. A preferred range of n is 1 to 5 for application to a magnetic conversion element such as an MR head for ultrahigh density magnetic recording.

The respective 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 the substrate 5, as described above, 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 within the film surface. As a result, Hk can be applied to the soft magnetic layer 20. Note that the external magnetic field is applied only when the soft magnetic layer 20 is formed, by using an apparatus having an electromagnet or the like that can easily control the application time of the magnetic field, and not when the pinning layer 50 is formed. It may be a method. Alternatively, a method of always applying a constant magnetic field during film formation may be used.

Next, the invention of the magnetoresistive effect element 3 including the magnetic multilayer film 1 described in the first embodiment was developed, and the electron flow path was examined in detail, and the first magnetic conversion element Invented. The magnetic conversion element mentioned here includes a magnetoresistive effect element, a conductive film and an electrode portion, and more specifically, a magnetoresistive effect type head (M
R head), MR sensor, ferromagnetic memory element, angle sensor, and the like.

Here, a magnetoresistive head (MR head) is taken as an example of the magnetic conversion element.
explain.

As shown in FIG. 5, the first magnetoresistive effect type head (MR head) 150 has a magnetoresistive effect element 200 as a magnetosensitive part for sensing a signal magnetic field, and this magnetoresistive effect element. Both ends 200a of the 200, 200a
And electrode portions 100, 100 formed on the. The end portions 200a, 200a of the magnetoresistive effect element 200 serving as the magnetically sensitive portion have their both end portions entirely in the electrode portion 10.
It is preferable that they are connected in contact with 0,100. In addition, the conductor films 120, 120 are the same as those of the electrode portion 10.
It is electrically connected to the magnetoresistive effect element 200 through 0 and 100. In the present invention, the conductor film 120 and the electrode portion 100 are separated for the sake of convenience in order to make the following description easy to understand. However, the conductor film 120 and the electrode portion 100 are originally formed integrally by a thin film forming method. In many cases, these may be considered as one member.

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

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

Here, the ferromagnetic layer 40 and the non-magnetic metal layer 30, which are used in the magnetoresistive effect element 200 as the magnetic sensitive portion,
The soft magnetic layer 20 and the pinning layer 50 are made of the same material as the film 1 described in the first magnetic multilayer film example, respectively.
It is desirable to use a thick one. As a result of detailed examination of the path of the current flowing through the magnetic multilayer film of the magnetoresistive element 200, it has been found that the electrons as the current are biased to a certain portion within the magnetic multilayer film. That is,
Of the layers forming the magnetic multilayer film, the pinning layer 50 is a material having a large specific resistance. For example, FeMn is 100-
FeNi has a specific resistance of 200 μΩcm, but 15 to 30 for FeNi.
μΩcm, which is quite small. Therefore, the electrons flow toward the soft magnetic layer 20 or the nonmagnetic metal layer 30 having a low specific resistance. In a conventional MR head, after forming a NiFe layer as a magnetically sensitive portion, an electrode was formed on the upper surface of the layer.
In this case, the electrode is in contact with the pinned layer having a large specific resistance, so that it becomes difficult for current to flow effectively. Further, the contact resistance is large, and the yield in the manufacturing process is also reduced.

Therefore, as shown in FIG. 5, the electrode portion 100 for passing a current is made to have a structure in which the entire end portions 200a, 200a are in contact with each other in the stacking direction of the magnetoresistive effect element 200, thereby solving these problems. It is possible. That is, the electrons flow around the portion sandwiched between the soft magnetic layer 20 and the ferromagnetic layer 40. Then, the soft magnetic layer 20 and the ferromagnetic layer 40 are magnetically scattered depending on the spin directions, and the resistance changes significantly. Therefore, a minute change in the external magnetic field can be detected as a large change in electric resistance.

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

The structure of the magnetoresistive effect element 200 in the second MR head will be specifically described with reference to FIG. The magnetic multilayer film of the magnetoresistive effect 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 on the substrate 5. The layer 30, the soft magnetic layer 20, and the metal protective layer 80 are laminated in this order. The pinned layer 50 and the pair of ferromagnetic layers 40 formed on both sides of the pinned layer 50 are
Joined by epitaxial growth.

When electrons flow through the magnetic multilayer film, the thickness of each layer is extremely thin, so that electrons have quantum probability and flow inside the multilayer film. That is, stochastically, electrons flow in the entire multilayer film, but the ratio of electrons flowing in the layer having a large specific resistance is naturally low. In general, the pinning layer 50 is 2 times thicker than the non-magnetic metal layer 30 and the soft magnetic layer 20.
With a specific resistance more than double. For example, Fe, which is an antiferromagnetic material
Mn has a specific resistance of 100 to 200 μΩcm, but FeNi, which is a soft magnetic material, has a very small value of 15 to 30 μΩcm. Therefore, the electrons flow toward the soft magnetic layer 20 or the nonmagnetic metal layer 30 having a low specific resistance. Here, the ferromagnetic layer 4 is symmetrically formed about the pinning layer 50 having a large specific resistance.
0, the non-magnetic metal layer 30, and the soft magnetic layer 20 are arranged. Therefore, when electrons flow in this multilayer film, there are two or more electron flow paths with the pinning layer 50 as a boundary. . As described above, stochastically electrons will flow in the entire multilayer film, but at least two or more electron flow paths should be formed by arranging a layer having a large specific resistance. Is possible. As a result, the number of electrons magnetically scattered by the antiparallel magnetization due to the external magnetic field increases, and the MR effect becomes larger than that in the case where the number of current paths is substantially one.

At this time, in order to substantially set two or more electron flow paths, as described above, the specific resistance of the pinning layer 50 is ρ _p , the specific resistance of the ferromagnetic layer 40 is ρ _f , and the soft resistance is ρ _f . When 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 electron flow paths. Is desirable. This can be achieved by forming a multilayer film including 1 to 4 pinning layers 50 with the above-described configuration. When the number of paths is three, for example, the soft magnetic layer 20, the non-magnetic metal layer 30, the ferromagnetic layer 40, on the metal underlayer 10 on the substrate 5,
Pinning layer 50, ferromagnetic layer 40, non-magnetic metal layer 30, soft magnetic layer 20, non-magnetic metal layer 30, ferromagnetic layer 40, pinning layer 50, ferromagnetic layer 40, non-magnetic metal layer 30, soft magnetic layer The layer 20 and the protective layer 80 are laminated in this order. In addition, route 4
In this case, for example, the soft magnetic layer 20, the nonmagnetic metal layer 30, and the ferromagnetic layer 4 are provided on the metal underlayer 10 on the substrate 5.
0, pinning layer 50, ferromagnetic layer 40, nonmagnetic metal layer 3
0, the soft magnetic layer 20, the non-magnetic metal layer 30, the ferromagnetic layer 40,
Pinning layer 50, ferromagnetic layer 40, non-magnetic metal layer 30, soft magnetic layer 20, non-magnetic metal layer 30, ferromagnetic layer 40, pinning layer 50, ferromagnetic layer 40, non-magnetic metal layer 30, soft magnetic layer The layer 20 and the protective layer 80 are laminated in this order. This route is 1
When it is 0 or more, the thickness of the entire magnetic multi-layer film becomes thick, and it becomes impossible to apply it to an MR head for super high density magnetic recording. Also, the number of paths may be one, but it is better to use two or more in order to obtain a larger MR effect. In terms of application, it is more preferably 2 to 5.

As described above, both ends 200a, 200a of the magnetoresistive effect element 200 are connected so that the entire ends thereof are in contact with the electrode portion 100, respectively. Therefore, all the electrons equivalently flow around the portion sandwiched between the formed two or more soft magnetic layers 20 and the ferromagnetic layer 40.
Then, the ratio of electrons 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 magnetoresistance change is enhanced. Therefore, a minute change in the external magnetic field can be detected as a large change in electric resistance. Further, since the pinning 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 becomes large. Compared with NiFe (permalloy) which is a conventional material, it is 3 to 10 times as large, but by forming a large number of electron flow paths in this way, it is possible to reduce the specific resistance to the same level as permalloy. Become. As a result, the temperature rise of the magnetic sensitive part due to flowing the measurement current,
It is possible to avoid the characteristic deterioration associated therewith.

Further, as described above, when there are two or more electron flow paths with the pinned 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 the layer thicknesses are adjusted so that 0.3 Ms ≦ Mf ≦ 0.8 Ms, preferably 0.4 Ms ≦ Mf ≦ 0.7 Ms, the balance between the layer thickness and the scattering efficiency becomes good.

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

Further, as described above, at least at the time of forming the soft magnetic layer 20, an anisotropic magnetic field Hk is induced by applying an external magnetic field in one direction in the film surface, thereby further improving the high frequency characteristics. can do. Here, M is added to the magnetic multilayer film.
An external magnetic field is applied in the direction in which a current for causing the R effect is applied, thereby inducing an anisotropic magnetic field. Usually, a magnetic multilayer film is processed into a strip shape, and an electric current is passed in the longitudinal direction thereof. Therefore, a magnetic field may be applied in the longitudinal direction to form the film.
In other words, it is advisable to apply the magnetic field in the same direction as the direction in which the current flows as the MR head, that is, in the in-plane direction perpendicular to the signal magnetic field direction to form the film. Then, in the soft magnetic layer forming the magnetic multilayer film, the longitudinal direction of the strip is the direction of easy magnetization,
The strip short side direction becomes the magnetization difficult direction, 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 characteristic of the soft magnetic layer is improved, and the MR characteristic in a large high-frequency region is obtained. The magnitude of the magnetic field applied here may be in the range of 10 to 300 Oe. Then, the anisotropic magnetic field Hk induced in the soft magnetic layer 20.
Is 3-20 Oe, more preferably 3-16 Oe, especially 3-1
It should be 2 Oe. When the anisotropic magnetic field Hk is less than 3 Oe, the coercive force of the soft magnetic layer 20 is almost the same, and a linear MR change curve centering on the 0 magnetic field is substantially not obtained, and the characteristics of the MR head are improved. 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 it is used as an MR head or the like, the output tends to decrease and the resolution also decreases. The film of the present invention exhibits high heat resistance, and the MR slope at the rising portion of the MR change curve is 0.3% / Oe or more, particularly 0.4% / Oe or more,
Usually 0.4 to 1.0% / Oe is obtained. 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 the antiferromagnetic layer as the pinning layer 50, it is preferable to apply a magnetic field in the direction perpendicular to the direction of the applied magnetic field when forming the soft magnetic layer 20. That is, it is in the film plane of the magnetic multilayer film and in the direction perpendicular to the measured current.
The magnitude of the magnetic field applied here may be in the range of 10 to 300 Oe. As a result, the pinning layer 50 reliably fixes the magnetization direction of the ferromagnetic layer 40 in the applied magnetic field direction (direction perpendicular to the measurement current), 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 direction as the direction of the magnetic field applied when forming the soft magnetic layer when forming the antiferromagnetic layer. At this time, a magnetic field is applied in the strip short side direction (the direction perpendicular to the applied magnetic field when forming the soft magnetic layer 20) when performing heat treatment at about 200 ° C. in the process after forming the magnetic multilayer film. It is better to lower the temperature while applying.

The magnetization rotation of the soft magnetic layer 20 defines the rising portion of the MR curve. In order to obtain a steeper rise of the MR curve, it is desirable that the soft magnetic layer 20 completely changes its magnetization direction by the magnetization rotation with respect to the signal magnetic field. However, in reality, magnetic domains are generated in the soft magnetic layer 20, and domain wall movement and magnetization rotation occur at the same time with respect to the signal magnetic field. As a result, Barkhausen noise was generated and the MR head characteristics were not stable.

Therefore, as a result of earnest studies, the inventors of the present invention have found that, as shown in FIG. 6, the magnetoresistive effect element 200, which is a magnetically sensitive portion, and the electrode portion 100 for passing a measurement current are respectively provided. It was confirmed that the noise can be improved by interposing the coupling soft magnetic layer 500. Of course, in this case, the connecting soft magnetic layer 500 and the entire end portions 200a and 200a of the magnetoresistive effect element 200 are connected in contact with the connecting soft magnetic layer 500. The connecting soft magnetic layers 500, 500 formed adjacent to the magnetoresistive effect element (magnetic multilayer film) magnetically directly contact the soft magnetic layer forming the magnetic multilayer film. The added coupling soft magnetic layer 500 has an effect of bringing the magnetic domains of the soft magnetic layer in the magnetic multilayer film closer to the 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 is free from noise.
Good characteristics can be obtained.

In order to bring the magnetic domain of the soft magnetic layer in the magnetic multilayer film close to that of a single magnetic domain to stabilize the magnetic domain structure, the structure shown in FIG.
Soft magnetic layers 510 and 510 having a shape as shown in FIG.
Is preferably provided. This soft magnetic layer 510 for connection
Indicates the magnetoresistive effect element 200 and the electrode portion 1 which are magnetically sensitive portions.
No. 00, and is continuously formed on the lower surface 101 of the electrode portion 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 when 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. . Further, in order to more positively stabilize the magnetic domain of the soft magnetic layer in the magnetic multilayer film, an antiferromagnetic layer is provided between the coupling soft magnetic layer for stabilizing the magnetic domain structure and the electrode portion 100. It may be sandwiched.

Generally, in an MR head using permalloy, a shunt layer such as Ti or CoZrMo, Ni is usually used.
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 magnetically sensitive portion. These are called soft film bias and shunt bias, and they work to shift the permalloy curve and create a linear region around the zero magnetic field. However, these mechanisms are complicated and, in the manufacturing process, are the factors that greatly reduce the manufacturing yield. On the other hand, in the above-described magnetoresistive effect element (magnetic multilayer film) of the present invention, since the MR curve rises from the vicinity of the zero magnetic field, the self-current generated by the current flowing through the magnetoresistive effect element (magnetic multilayer film). The bias can produce a linear region around the zero magnetic field. As a result, since it is not necessary to provide a biasing method having a complicated mechanism, it is possible to improve the manufacturing yield, shorten the manufacturing time, and reduce the cost. Further, since there is no bias mechanism, the thickness of the magnetically sensitive portion becomes thin, so that the shield thickness when used as an MR head becomes small, which is very effective in shortening the wavelength of the signal due to ultra-high density recording.

When manufacturing these MR heads, heat treatment such as baking, annealing, resist curing, etc., is inevitable in the manufacturing process, such as patterning and flattening.

In a magnetoresistive effect element having a magnetic multilayer film generally called an artificial lattice, heat resistance often becomes a problem due to the thickness of each layer constituting the magnetoresistive effect element. In the magnetoresistive effect element (magnetic multilayer film) according to the present invention, a magnetic field is applied to give an anisotropic magnetic field to the magnetic layer,
0 ° C or lower, generally 50 to 400 ° C, 100 to 300 ° C,
Sufficiently compatible with heat treatment for about 2 hours. The heat treatment is usually
It may be performed in a vacuum, an inert gas atmosphere, an air, etc., but especially in a vacuum (under reduced pressure) of 10 ^-7 Torr or less, a magnetoresistive effect element (magnetic multilayer film) with extremely little characteristic deterioration can be obtained. To be Further, MR characteristics are hardly deteriorated even in lapping and polishing in the processing step.

[0131]

EXAMPLES The inventions of the first and second magnetoresistive elements and the inventions of the first and second magnetic conversion elements (for example, MR heads) using them will be further described by the following specific examples. The details will be described. First, a specific embodiment of the invention of a magnetoresistive effect element 3 (corresponding to FIG. 1) having a magnetic multilayer film 1 will be shown as a first embodiment.

Example 1 A glass substrate was used as a substrate, which was placed in an ion beam sputtering apparatus and vacuumed to 1 × 10 ⁻⁷ Torr. The substrate temperature is 20 ° C while it is cooled to 10 ° C.
While rotating at rpm, an artificial lattice magnetic multilayer film having the following composition was prepared. At this time, the magnetic field is in the plane of the substrate and
Film formation was performed at a film formation rate of about 0.3 Å / sec or less while applying in the direction parallel to the measurement current. Ar flow rate is 8-10scc
m, the sputter gun acceleration voltage 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 perpendicular to the measurement current and in the in-plane direction to induce the pinning effect of the ferromagnetic layer. In this way, samples 1 to 11 of the present invention as shown in Table 1 were prepared.

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

In the m1 material in Table 1, NiFe (Samples 1, 2, 3, 10 to 13, 15, and 17) is Ni
_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), which represents 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
It represents Co _0.16 (wt ratio).

For the m4 material in Table 1, Sample 1,
2, 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 made of different materials, and Sample 11 is a structural defect. This is an example of an introduced layer, that is, an example in which this layer was formed while introducing structural defects when the Fe ₃₀ Tb ₇₀ layer was formed. Furthermore, m in Table 1
Of 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), CoFe of sample 3 is Co _0.81 F
e _0.19 , CoFeNi of sample 10 is Co _0.72 Fe
_0.13 represents Ni _0.15 .

The characteristic evaluation common to each invention will be described below. The BH loop was measured by a vibrating magnetometer. For 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 a plane 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 obtained 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 taken as the MR slope (unit:% / Oe) to evaluate the rising characteristics. This value must be 0.3% / Oe or more as described above.

Sample 1 has NiFe as two magnetic layers.
(Permalloy) is used. The MR change rate is 1.8%, but the MR gradient is as large as 0.57% / Oe. FIG. 8 shows an MR curve measured with a DC magnetic field. This is the output voltage when measured with a measuring current of 5 mA. The MR curve rises largely near the zero magnetic field, and shows a large MR slope. In Sample 2, when the ferromagnetic layer is Co, in Sample 3, pinning is performed by direct exchange coupling using ferromagnetic layers made of different materials. In addition, in this sample 3, before the FeCo layer is sputtered, the flow rate of Ar in the Co layer is 10 sccm, the acceleration voltage of the ion gun is 100 V,
Irradiation with an assist ion beam with an ion current of 10 mA was performed to roughen the interface portion and introduce an artificial structural defect.

In addition, sample 1 of the present invention shown in Table 1
As a result of observing a cross section with respect to Nos. 11 through X-ray diffraction and a transmission electron microscope, the ferromagnetic layer and the so-called pinning layer are connected to each other by lattice fringes, and the mutual layers are formed by epitaxial growth. Was confirmed.

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

Samples 13 (comparative) and 14 (comparative)
In each case, the pinning layer (corresponding to m4) is not formed.

Sample 15 (comparative) has the same multilayer film structure as sample 1, but the ferromagnetic layer and the so-called pinning layer are not formed by epitaxial growth due to the difference in film forming conditions. 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
It was 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 pinning layer and the ferromagnetic layer were not confirmed. Therefore, there was no epitaxial growth condition between these layers.

Sample 16 (comparative) has the same multilayer film structure as sample 8, but the ferromagnetic layer and the so-called pinning layer are not formed by epitaxial growth due to the difference in film forming conditions. Sample 16 (comparison)
Is prepared by the same film forming method as the sample 15 (comparative).

Sample 17 (comparative) has the same multilayer film structure as Sample 10, but the ferromagnetic layer and the so-called pinning layer are not formed by epitaxial growth due to the difference in film forming conditions. Sample 17 (comparison)
Is prepared by the same film forming method as the sample 15 (comparative).

[0144]

[Table 1] From the results shown in Table 1, by forming a ferromagnetic layer and a so-called pinning layer by epitaxial growth and pinning the magnetization direction of the ferromagnetic layer, a large MR gradient exceeding 0.3% / Oe is exhibited. It 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. Further, it can be seen that the pinning effect is brought about by one selected from the antiferromagnetic layer, the hard ferromagnetic layer, the ferromagnetic layers made of different materials, and the layer introduced with the artificial structural defect.

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

Example 2 A glass substrate was used as a substrate, placed in an ion beam sputtering apparatus, and vacuumed to 1 × 10 ⁻⁷ Torr.
While rotating the substrate while cooling the substrate temperature to 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 Å / 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 sputter gun acceleration voltage was 300 V, and the ion current was 30 mA. After film formation, 10
^-20 Torr in a plane perpendicular to the measured current in a vacuum of ^-7 Torr
The pinning effect of the ferromagnetic layer was induced by cooling from 150 ° C. while applying a magnetic field of 0 Oe.

The structure of the magnetic multilayer film and the rate of change in magnetoresistance are shown in Table 2 below.

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 70Å thick Fe 50% -M
On both sides of the anti-ferromagnetic layer (pinning layer) of n50% FeMn alloy, 70Å thick N used as the ferromagnetic layer, respectively.
iFe alloy layer, 30Å thick Cu non-magnetic metal layer, 70Å
Thick Ni 81% -Fe 19% permalloy composition (NiF
It is a magnetic multilayer film in which a soft magnetic layer according to e) and a Ta metal layer having a thickness of 70Å are sequentially arranged. The materials constituting each sample are shown as (m1, m2, m3, m4) in the order of the soft magnetic layer, the non-magnetic metal layer, the ferromagnetic layer, and the antiferromagnetic layer (pinned layer). In addition, those 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 those in Examples 1 and 2. Also, the MR slope in a DC magnetic field and 1
The MR slope (unit:% / Oe) in the width of 6 Oe in the high frequency magnetic field at MHz is also shown. This value is 0.2 as above
% / Oe or more is required. 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 each layer thickness 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 of the magnetoresistive effect element 4 (corresponding to FIG. 4) having the magnetic multilayer film 2 according to the invention.
2 is the same as samples 1 and 2 in Table 1,
There is one soft magnetic layer and one antiferromagnetic layer (corresponding to FIG. 1). By observing the cross section of the laminated film by X-ray diffraction and a transmission electron microscope, samples 2-1 to 2-4,
It was confirmed that the laminated layers of the ferromagnetic layer and the so-called pinned layer in Samples 1 and 2 were formed by epitaxial growth.

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

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

Comparing these, the MR gradient of the rising portion of the MR curve is larger in the magnetoresistive element 4 having the magnetic multilayer film 2 according to the present invention, 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.

From the results shown in Table 2, the ferromagnetic layer, the non-magnetic metal layer, and the soft magnetic layer were laminated in this order on both sides of the pinning layer, and in particular, the pinned layer was formed. By joining the stop layer and the ferromagnetic layers on both sides of this pinned layer by epitaxial growth, not only the MR change rate and the MR slope in the DC magnetic field but also the high frequency represented by the MR slope at 1MHz, which is the most important for the application. It can be seen that the MR characteristics are greatly improved. Due to this structure, especially sample 2-1
~ 2-4 only large high frequency MR exceeding 0.3% / Oe
Indicates the slope.

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

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 of the characteristics both in the initial stage and after the heat treatment. That is, it is understood that the magnetoresistive effect element 4 having the magnetic multilayer film 2 exhibits a large MR gradient in a large DC field exceeding 0.3% / Oe and a large high-frequency MR gradient at 1 MHz.

10A and 10C show the magnetization curves of the magnetic multilayer film constituting Sample 1 in Table 1 immediately after the film formation and after the heat treatment, respectively, and FIG.
And (D) show MR curves immediately after the formation of the magnetic multilayer film constituting Sample 1 of Table 1 and after the heat treatment, respectively. 11 (A) and 11 (C) show Table 2 respectively.
11B shows the magnetization curves of the magnetic multilayer film constituting Sample 2-1 immediately after the film formation and after the heat treatment, and FIGS. 11B and 11D show the magnetic multilayer films constituting Sample 2-1 of Table 2, respectively. The MR curves immediately after film formation and after heat treatment are shown. In sample 2-1, since the magnitude of the exchange coupling force at the upper and lower sides of the antiferromagnetic layer (pinned layer) is different, Hex is different at the upper and lower soft magnetic layers after the heat treatment. However, in both of the samples, the rising portion of the MR curve near the zero magnetic field, which is important for application, has hardly changed, and good MR characteristics of the magnetization curve are maintained immediately after film formation and after heat treatment. Recognize. 12
Samples 2 of Table 2 are shown in (A) and (B), respectively.
2 shows the X-ray diffraction curves immediately after film formation and after heat treatment. The diffraction intensity of the (111) oriented surface from the NiFe and Co layers near 44 degrees is slightly stronger after the heat treatment than immediately after the film formation, but it shows that there is essentially no change.

Further, FIG. 13 shows sample 2-1 of Table 2.
4 shows changes in MR slope when the samples were heat-treated under various pressures. Almost M at any pressure at a temperature of 250 ° C
Although the R slope does not change, at 350 ° C., a difference occurs due to the pressure. That is, in the heat treatment in the pressure range lower than 10 ⁻⁷ Torr, the MR slope maintains a large value.
The MR slope deteriorates in the range where the pressure is higher than 0 ^-7 Torr. This is because the magnetic multilayer film is oxidized by a small amount of residual oxygen even in a vacuum state. But,
At 450 ° C, the MR slope deteriorated even under a pressure of 10 ^-9 Torr. Therefore, by heat treatment at a pressure lower than 10 ^-7 Torr, M in the temperature range of 400 ° C or lower
It can be seen that the R slope maintains a large value.

Furthermore, in the invention of the magnetoresistive effect element 4 (corresponding to FIG. 4) having the magnetic multilayer film 2, the specific resistance ρ _p of the pinning layer, the specific resistance ρ _f of the ferromagnetic layer, and the soft magnetic layer. An experiment was conducted to examine how the three-way relationship with the specific resistance ρ _s affects the characteristics of the multilayer film. That is, magnetic multilayer films (corresponding to FIG. 4) having various laminated compositions as shown in Table 4 below were prepared, and the specific resistance ρ _p , ρ _f , ρ of each layer
_s and 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 of Table 4, the value of R * = ρ _p / [(ρ _s + ρ _f ) / 2] is 3
It is understood that the results are in the range of ˜30, that is, the samples 4-1 to 4-4 satisfying the following formula (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 examine the stacking order of each layer of the magnetoresistive effect 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. A magnetic multilayer film of Comparative Sample 5-1 in which the above was changed was produced. That is, the magnetic multilayer film of Comparative Sample 5-1 was obtained by forming NiFe (70Å) / Cu (30) on the Ta underlayer (50Å).
Å) / NiFe (70Å) / FeMn (70Å) / Cu
(30Å) / NiFe (70Å) / Cu (30Å) / N
iFe (70Å) / FeMn (70Å) / Cu (50
Å) is sequentially laminated and produced. This is based on the magnetic multilayer film 1 shown in FIG.
0 Å) is sandwiched between two layers in the same stacking order. The MR curve of this comparative sample 5-1 is shown in FIG.
8 shows.

From the graph shown in FIG. 18, the comparative sample 5-1 has an extremely small MR change rate shown on the vertical axis, and conversely to the case where the applied magnetic field in the MR curve is increased. 0 in case of decreasing
It was confirmed that the values of the MR change rate in the vicinity of the magnetic field did not match, and that this could not be put to practical use at all. This is because the NiFe layer which is the first ferromagnetic layer and the Fe layer which is the pinning layer are sequentially laminated from the Ta underlayer side.
Even if the Mn layer is joined by the epitaxial growth, the epitaxial growth is gradually lost as the Cu, NiFe, and Cu layers are stacked again.
It indicates that no epitaxial relationship is obtained between the iFe-FeMn layers. Therefore, in order to pin the ferromagnetic layer most efficiently, the 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 grown epitaxially. 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 a magnetic conversion element.

Example 3 On an AlTiC (AlTiC) substrate, Ta was deposited to a thickness of 50Å as a metal underlayer, and NiFe (70
Å) -Cu (30Å) -NiFe (70Å) -FeMn
The layers were laminated in the order of (70Å) to form a magnetic multilayer film. Ni
Fe represents Ni _0.81 Fe _0.19 . The film forming conditions are an ultimate pressure of 2 × 10 ⁻⁷ Torr, a film forming pressure of 1.4 × 10 ⁻⁴ Torr, and a substrate temperature of about 10 ° C., and each material is 0.2 to 0.3 Å / sec.
During the film formation, the film formation was performed 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. Junction by epitaxial growth was confirmed between the NiFe-FeMn layers.

After that, a pattern of 20 μm × 6 μm was formed as a magnetically sensitive portion by using the photolithography technique, and an electrode having a track width of 3 μm was formed on the patterned portion to obtain an MR head. The structure of the manufactured MR head is as shown in FIG. Then, in a vacuum of 10 ^-5 Torr, the magnetic field of 200 Oe was applied in a direction perpendicular to the measurement current direction and cooled from 150 ° C. to induce the pinning effect of the ferromagnetic layer. FIG. 14 shows changes in the output voltage when the measurement current was changed to 5 mA and the external magnetic field was changed to ± 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 used under the same conditions as in Example 3 above to fabricate an MR head utilizing the conventionally used anisotropic magnetoresistive effect. The measurement current was 5 mA, and the external magnetic field was changed in the range of ± 20 Oe and 50 Hz. The output voltage at this time was 0.8 mV.

The first aspect of the present invention is obtained by the third embodiment and the first comparative example.
In the MR head, the output was nearly three times as high as that of the conventional example. Therefore, the effect of the present invention is clear.

[0168]Example 4 As a metal underlayer on an AlTiC substrate
A Ta film is formed to a thickness of 50 Å and NiFe (70
Å) -Cu (30Å) -NiFe (70Å) -FeMn
(70Å) -NiFe (70Å) -Cu (30Å) -N
iFe (70Å) layers are laminated in this order to form a magnetic multilayer film.
It was The film forming condition is an ultimate pressure of 1.7 × 10.^-7Torr, during film formation
Pressure 1.4 × 10^-FourTorr, substrate temperature of about 10 ℃,
The material is deposited at a deposition rate of 0.2 to 0.3Å / sec during film formation.
Do not apply a magnetic field in the plane of the substrate and parallel to the measured current.
Film formation by the ion beam sputtering method. That
After 10 ^-FiveIn the vacuum of Torr, perpendicular to the measuring current direction and plane
Cool from 150 ℃ while applying a magnetic field of 200 Oe inward.
On the contrary, the pinning effect of the ferromagnetic layer was induced. Other articles
An MR head was manufactured in the same manner as in Example 3 above.
Epitaxial growth for NiFe-FeMn-NiFe
The joining was confirmed.

The structure of the manufactured MR head is as shown in FIG. FIG. 15 shows changes in the output voltage when the external magnetic field is changed within the range of ± 20 Oe and 50 Hz. An output voltage of 3.0 mV was obtained in the MR head using the artificial lattice magnetic multilayer film according to the present invention. As compared with Example 3, the resistance value 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 convenient that the specific resistance is small because the 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. With the MR head of the present invention, an effect of approximately 3.8 times was confirmed as compared with the conventional example.

Embodiment 5 Furthermore, FIG. 16 shows an example in which the magnetoresistive effect element of the present invention is applied to a yoke type MR head. Here, a notch is provided in a part of the yokes 600, 600 for guiding the magnetic flux, and the magnetoresistive effect element 200 has a thin insulating film 40 therebetween.
It is formed through 0. This magnetoresistive element 20
At 0, electrodes (not shown) for passing a current in a direction parallel to or perpendicular to the magnetic path formed by the yokes 600, 600 are formed. As a result, it was confirmed that the output was double that of the MR head using Permalloy. Since the magnetic multilayer film of the present invention has a good rising characteristic at 0 magnetic field, it is not necessary to provide a shunt layer or a bias magnetic field applying unit that is normally used.

Embodiment 6 FIG. 17 shows another embodiment in which a magnetic conversion element, for example, an MR head is constructed using the magnetoresistive effect element of the present invention. The magnetoresistive effect element 200 is formed in magnetic contact with the high resistivity flux guide layers 700 and 710. This flood guide layer is a 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 because it is made of a material having a specific resistance that is three times or more higher. On the other hand, the flux guide layer 700 and the magnetic multilayer film 20
Since it is in magnetic contact with 0, the signal magnetic field is guided to the flux guide layer 700 and does not lose its strength.
The magnetic multilayer film 200 is reached. Reference numeral 600 denotes another different flux guide layer, which functions as a return guide for the magnetic flux that has passed 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 resistivity flux guide layers 700 and 710. Further, the guide layers 710 and 600 may be in contact with the medium at the far end.
At this time, 3 from the MR head when using Permalloy.
Double output was confirmed. In the figure, reference numeral 400 is a non-magnetic insulating layer.

[0173]

As described above, the magnetic multilayer film 1
According to the first invention relating to the magnetoresistive effect element having, the magnetoresistive effect element having an MR gradient of 0.3% / Oe or more in resistance change rate can be obtained. Moreover, the rising characteristics of the MR curve at 0 magnetic field are extremely good, and in addition, high heat resistance is exhibited. According to the second invention relating to the magnetoresistive effect element having the magnetic multilayer film 2, in addition to the above,
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 if the pressure is 10 ^-7 Torr or less, the characteristics are not deteriorated even by heat treatment at about 350 ° C. Does not happen. In a magnetic conversion element using a magnetoresistive effect element having the magnetic multilayer film 1, for example, an MR head, it is possible to obtain an output voltage nearly three times as large as that of a conventional material. Further, in a magnetic conversion element using a magnetoresistive effect element having the magnetic multilayer film 2, for example, an MR head, the MR inclination in the high frequency region shows a high value of 0.3% / Oe or more, the specific resistance is small, and the measured current is small. The amount of heat generated by is small, 3.8
The output voltage can be doubled. Therefore, it is possible to provide a highly reliable MR head capable of reading super-high density magnetic recording exceeding 1 Gbit / inch ² .

[Brief description of drawings]

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

FIG. 2 is a schematic view of the structure of a magnetoresistive effect 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 effect element of a second invention.

FIG. 5 is a partially omitted sectional view showing an example of a magnetic conversion element of the present invention.

FIG. 6 is a sectional view showing a structure of a magnetoresistive effect element (magnetic multilayer film) and an electrode portion of the magnetic conversion element of the present invention.

FIG. 7 is a cross-sectional view showing another example of the structure of the magnetoresistive effect element (magnetic multilayer film) and the electrode portion of the magnetic conversion element of the present invention.

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

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

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

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

FIG. 13 is a relationship between the pressure and the MR slope 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. It is a graph which shows.

FIG. 14 is a magnetic conversion element (MR) of the first invention.
3 is a chart showing an applied magnetic field of a head) and an output voltage.

FIG. 15 is a diagram showing a magnetic conversion element (MR) of the second invention.
3 is a chart showing an applied magnetic field of a head) and an output voltage.

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 graph showing a magnetoresistive element (magnetic multilayer film) of the present invention applied to a flux guide type MR head.
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 effect element 5 ... Base | substrate 7 ... Magnetic multilayer unit 10 ... Metal underlayer 20 ... Soft magnetic layer 30 ... Nonmagnetic metal layer 40 ... Ferromagnetic layer 50 ... Pinning layer 60 ... Interface between ferromagnetic layer and pinning layer 80 ... Protective layer 90 ... Recording medium 93 ... Recording surface 150 ... Magnetoresistive head 200 ... Magnetoresistive element

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location H01L 43/08 Z 43/10

Claims (30)

[Claims] 1. A magnetic conversion element including a magnetoresistive effect element, a conductor film, and an electrode portion, wherein the conductor film is electrically connected to the magnetoresistive effect element through the electrode portion, The magnetoresistive element includes 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, and the ferromagnetic layer. A magnetic multilayer film having a pinning layer formed on the ferromagnetic layer to pin the direction of magnetization of the ferromagnetic layer and the pinning layer are joined by epitaxial growth. A magnetic conversion element characterized by the above. 2. The pinning layer has an antiferromagnetic layer, a hard magnetic layer, a pinning ferromagnetic layer made of a material different from the ferromagnetic layer connected to the pinning layer, and an artificial structural defect. The magnetic conversion element according to claim 1, which is at least one selected from the introduced layers. 3. The ferromagnetic layer is (Co _z Ni _1-z ) _w
Fe _1-w (however, 0.4 ≦ z ≦ 1.0, 0.5 by weight
≦ w ≦ 1.0), and the soft magnetic layer is (Ni _x Fe _1-x ) _y Co _1-y (where 0.7 ≦ x ≦ 0.9 by weight). , 0.5 ≦ y ≦ 1.0), The magnetic conversion element according to claim 1 or claim 2. 4. The ferromagnetic layer is (Co _z Ni _1-z ) _w
Fe _1-w (however, 0.4 ≦ z ≦ 1.0, 0.5 by weight
≦ w ≦ 1.0), and the soft magnetic layer has a composition of Co _t M _u M ′ _q B _r (provided that the number of atoms is 0.6).
≤t≤0.95, 0.01≤u≤0.2, 0.01≤q
≦ 0.1, 0.05 ≦ r ≦ 0.3; M is at least one selected from Fe and Ni, M ′ is Zr,
The magnetic conversion element according to claim 1, which has a composition represented by at least one selected from Si, Mo, and Nb). 5. The magnetic conversion element according to claim 1, wherein the nonmagnetic metal layer is made of a material containing at least one selected from Au, Ag, and Cu. 6. When the pinning layer is composed of a hard magnetic layer, the hard magnetic layer is made of one metal selected from Fe, Co and Ni, or Fe, C
50 wt% of one metal selected from o and Ni
When the pinning layer is made of an alloy containing the above and the pinning layer is formed of an antiferromagnetic layer, the antiferromagnetic layer is formed of Fe, Ni, Co,
The magnetic conversion element according to any one of claims 2 to 5, which is made of a material containing at least two or more selected from Cr, Mn, Ru, Rh, Mo, and O. 7. 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 specific resistance relationship between them is as follows: The magnetic conversion element according to any one of claims 1 to 6, which satisfies 1). 3 ((ρ _f + ρ _s ) / 2) <ρ _p <30 ((ρ _f + ρ _s ) / 2) ... Equation (1) 8. The magnetoresistive effect element according to claim 1, wherein a gradient of magnetoresistive change in a width of 6 Oe in a high frequency magnetic field of 1 MHz is 0.2% / Oe or more.
The magnetic conversion element according to any one of 1. 9. The magnetic conversion element according to claim 1, wherein the magnetic conversion element is a magnetoresistive head. 10. The magnetic conversion element according to claim 9, wherein both end portions of the magnetoresistive effect element are joined in a state where the entire end portion is in contact with the electrode portion. 11. A magnetoresistive effect element further has a coupling soft magnetic layer between the electrode portions formed at both ends thereof, and the coupling soft magnetic layer and the end portion of the magnetoresistive effect element as a whole. The magnetic conversion element according to claim 10, wherein the magnetic conversion elements are connected in contact with each other. 12. The connecting soft magnetic layer is continuous so as to be in contact with the magnetoresistive effect element and the electrode portions formed at both ends of the magnetoresistive effect element, and so as to contact the lower surface of the electrode portion. The magnetic conversion element according to claim 11, wherein the magnetic conversion element is formed as follows. 13. The magnetic conversion element according to claim 9, which does not have a bias magnetic field applying mechanism. 14. The ferromagnetic layer is formed by applying an external magnetic field of 10 to 300 Oe in the film in-plane direction, which is the same as the signal magnetic field direction during film formation. 14. The magnetic conversion element according to claim 9, which is formed by applying an external magnetic field of 10 to 300 Oe in the in-plane direction perpendicular to the signal magnetic field direction during the film formation. 15. A magnetic conversion element including a magnetoresistive effect element, a conductor film, and an electrode portion, wherein the conductor film is electrically connected to the magnetoresistive effect element via the electrode portion, The magnetoresistive effect element includes 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. The magnetic conversion device is provided with a magnetic multilayer film having a magnetic multilayer film unit in which magnetic layers are sequentially arranged, and the ferromagnetic layer and the pair of pinning layers are respectively joined by epitaxial growth. element. 16. The pinning layer has an antiferromagnetic layer, a hard magnetic layer, a pinning ferromagnetic layer made of a material different from the ferromagnetic layer connected to the pinning layer, and an artificial structural defect. The magnetic conversion element according to claim 15, which is at least one selected from the introduced layers. 17. The ferromagnetic layer is (Co _z Ni _1-z ).
_w Fe _1-w (however, 0.4 ≦ z ≦ 1.0 by weight, 0.
5 ≦ w ≦ 1.0), and the soft magnetic layer is (Ni _x Fe _1-x ) _y Co _1-y (however, 0.7 ≦ x ≦ 0. 9, 0.5 ≦ y ≦ 1.0)
The magnetic conversion element according to claim 15 or 16, which has a composition represented by: 18. The ferromagnetic layer is (Co _z Ni _1-z ).
_w Fe _1-w (however, 0.4 ≦ z ≦ 1.0 by weight, 0.
5 ≦ w ≦ 1.0), and the soft magnetic layer has a composition of Co _t M _u M ′ _q B _r (provided that the atomic number is 0.
6 ≦ t ≦ 0.95, 0.01 ≦ u ≦ 0.2, 0.01 ≦
q ≦ 0.1, 0.05 ≦ r ≦ 0.3; M is Fe, Ni
At least one selected from the group M'is Z
The magnetic conversion element according to claim 15 or 16, which has a composition represented by at least one selected from r, Si, Mo, and Nb). 19. The magnetic conversion element according to claim 15, wherein the non-magnetic metal layer is made of a material containing at least one selected from Au, Ag, and Cu. 20. When the pinning layer is composed of a hard magnetic layer, the hard magnetic layer is made of one metal selected from Fe, Co and Ni, or Fe,
50wt% of one metal selected from Co and Ni
% Or more, and when the pinning layer is formed of an antiferromagnetic layer, the antiferromagnetic layer is made of Fe, Ni, C
20. The magnetic conversion element according to claim 16, which is made of a material containing at least two or more selected from o, Cr, Mn, Ru, Rh, Mo, and O. 21. 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 magnetic conversion element according to any one of claims 15 to 20, wherein the specific resistance relationship satisfies the following expression (1). 3 ((ρ _f + ρ _s ) / 2) <ρ _p <30 ((ρ _f + ρ _s ) / 2) ... Equation (1) 22. The magnetoresistive effect element according to claim 15, wherein a gradient of magnetoresistance change in a width of 6 Oe in a high frequency magnetic field of 1 MHz is 0.2% / Oe or more.
1. The magnetic conversion element according to any one of 1. 23. The magnetic conversion element according to claim 15, wherein the magnetic conversion element is a magnetoresistive head. 24. The magnetic conversion element according to claim 23, wherein both end portions of the magnetoresistive effect element are joined in a state where the entire end portion is in contact with the electrode portion. 25. A soft magnetic layer for connection is further provided between the electrode portions formed on both ends of the magnetoresistive effect element, and the soft magnetic layer for connection and the entire end of the magnetoresistive effect element. 25. The magnetic conversion element according to claim 24, wherein the magnetic conversion elements are connected in contact with each other. 26. The soft magnetic layer for connection is continuous between the magnetoresistive effect element and the electrode portions formed at both ends of the magnetoresistive effect element, and so as to contact the lower surface of the electrode portion. 26. The magnetic conversion element according to claim 25, which is formed by the following method. 27. The magnetic conversion element according to claim 23, which does not have a bias magnetic field applying mechanism. 28. The ferromagnetic layer is formed by applying an external magnetic field of 10 to 300 Oe in the in-plane direction, which is the same as the signal magnetic field direction during film formation. 28. The magnetic conversion element according to claim 23, which is formed by applying an external magnetic field of 10 to 300 Oe in the in-plane direction perpendicular to the signal magnetic field direction during the film formation. 29. 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, and the ferromagnetic layer. A magnetoresistive effect element comprising a magnetic multilayer film having a pinning layer formed on a ferromagnetic layer for pinning the direction of magnetization, wherein the ferromagnetic layer and the pinning layer are: A magnetoresistive element characterized by being joined by epitaxial growth. 30. A pinning layer for pinning the magnetization direction of adjacent ferromagnetic layers, 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, respectively. A magnetoresistive effect element comprising a magnetic multilayer film having a magnetic multilayer film unit formed by sequentially arranging layers, wherein the ferromagnetic layer and the pinning layer are joined by epitaxial growth. Magnetoresistive effect element.