JP2003051630A - Magnetoresistance effect device and magnetic head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetoresistance effect device, a magnetic head and a read/write device using it, the magnetoresistance effect device being capable of detecting the variation of a very small amount of leakage flux from a high density magnetic recording medium made to have a narrow track with high sensitivity and high resolution. SOLUTION: In this device structure, all electric currents flow through a magnetoresistance effect film, and a non-magnetic metal (conductor) as an electrode is connected to at least one part of the magnetoresistance effect film, so that a magnetic field in a narrow region can be detected with high sensitivity and high resolution. For example, at least one part of the magnetoresistance effect film having a multilayer structure is formed on a conductor consisting of non-magnetic metal, and the surface direction of all the magnetic layers of the magnetoresistance effect film is made nearly perpendicular to the surface of the magnetic recording medium. Namely, in this device structure, the area of the magnetic layers at the end surface of the magnetoresistance effect film, having the multilayer structure is made very small.

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 using a multilayer magnetic thin film having a high magnetoresistive effect, and particularly for achieving high density recording by using a narrow track magnetic recording medium. The present invention relates to a magnetoresistive effect element suitable for a reproducing magnetic head used in a magnetic recording / reproducing apparatus.

[0002]

2. Description of the Related Art As a reproducing magnetic head for high density magnetic recording, a magnetic head utilizing a magnetoresistive effect has been studied. Currently, as the magnetoresistive material, Ni is used.
A -20 at% Fe alloy thin film is used. But Ni
A magnetoresistive element using a -20 at% Fe alloy thin film is
Often shows noise such as Barkhausen noise,
Research on other magnetoresistive materials is also in progress.

On the other hand, recently, utilizing the ferromagnetic tunnel phenomenon,
A multi-layer in which a pair of magnetic layers are laminated with an insulating layer in between.
Magnetoresistive film that detects magnetic flux from changes in film electrical resistance
About Proceedings of the International
Naru Symposium on Physics of Magnete
Ick Materials, April 8-11, 1987, 3rd
03 to 306 [Proceedings of the Internati
onal Symposium on Physics of Magnetic Materials,
(April 8-11, 1987) pp.303-306].
Here, there is a Ni / NiO / Co junction as a multilayer structure.
Is Al / Al_TwoO _Three/ Ni, Co-Al / Al_TwoO_Three/ N
Introduced a multilayer film showing ferromagnetic tunnel effect such as i
There is. However, in any case, a pair of magnetic layers
Bonding area is 1mm^TwoWide and resistance change rate Δρ /
ρ is small at around 1% at room temperature. Also shown in this example
With the existing element structure, minute magnetic flux changes can be resolved.
Magnetic recording in which recording signals are written at high density
Sensitive detection of changes in magnetic flux leaking from the medium
There was a problem that I could not.

[0004]

In the above-mentioned prior art, for example, in a Ni / NiO / Co multilayer film, the Ni layer and the Co layer having a rectangular shape are made orthogonal to each other,
All currents are made to pass through the NiO layer, and the resistance change due to the ferromagnetic tunnel effect is effectively detected. However, considering the application to a magnetic head, the ferromagnetic Ni
If the layers and the Co layer are made orthogonal to each other, the longitudinal direction of one of the magnetic layers becomes parallel to the surface of the magnetic recording medium, which is a disadvantageous element shape for detecting a magnetic field in a narrow region.
That is, there has been a problem that the magnetic flux change corresponding to the recording signal having a narrow track width cannot be detected with high sensitivity.

An object of the present invention is to solve the problems in the case of applying the conventional multilayer film exhibiting the magnetoresistive effect to a magnetic head and to highly sensitively detect a minute change in magnetic flux in a narrow area.
It is another object of the present invention to provide a magnetoresistive effect element capable of detecting with high resolution, a magnetic head using the same, and a recording / reproducing apparatus.

[0006]

The inventors of the present invention have found that the magnetic layer has an insulator such as Al ₂ O ₃ , SiO ₂ , NiO and BN or a semiconductor such as Si, Ge and GaAs or an antiferromagnetic material such as Cr. As a result of intensive research on the shape of the magnetoresistive effect element formed by using the magnetoresistive effect film having a multilayer structure in which an intermediate layer made of a body or the like is inserted, all the currents flowing in the magnetoresistive effect film are A magnetic element that can detect a magnetic field in a narrow area with high sensitivity by using an element structure that passes through without fail and a non-magnetic metal (conductor) as an electrode connected to at least a part of the magnetoresistive film. They have found that a resistance effect element can be constructed, and completed the present invention. In the present invention, for example, at least a part of the multi-layered magnetoresistive effect film is formed on a conductor made of a non-magnetic metal, and the film surface direction of all the magnetic layers of the magnetoresistive effect film is set to By providing an element structure that can be arranged substantially at right angles to each other, that is, an element structure in which the end surface portion of the magnetoresistive effect film having a multilayer structure is opposed to the surface of the magnetic recording medium Since the area of the magnetic layer in the portion can be made extremely small, minute changes in the leakage magnetic flux from the high density magnetic recording medium with a narrowed track can be detected with high sensitivity and high resolution. .

Magnetoresistive film having a multilayer structure of the present invention
As (1) the magnetic layer, Al_TwoO _Three, SiO_Two, Ni
Insulator such as O and BN or half such as Si, Ge and GaAs
A multilayer film with an intermediate layer made of a conductor or the like inserted, for example, Ni /
Ni / Co, Fe / Ge / Co, Al / Al_TwoO_Three/ Ni,
Co-Al / Al_TwoO_Three/ Ni, Fe-C / SiO_Two/ Fe
-Ru, Fe-C / Al_TwoO_Three/ Co-Ni, Fe-C / A
l_TwoO_ThreeUtilizing the ferromagnetic tunnel effect such as / Fe-Ru
Magnetic thin film, (2) The magnetic layer is made of antiferromagnetic material such as Cr.
Multilayer film with an intermediate layer inserted, such as antiferromagnetism such as Fe / Cr
Examples of the magnetic thin film using a magnetic intermediate layer include the magnetic thin film of the present invention.
The air resistance effect element structure has the above (1) and (2)
Suitable use of some type of magnetoresistive film
You can

Further, in the magnetoresistive effect element of the present invention, in order to detect a minute change in magnetic flux with high sensitivity and obtain a stable reproduction output with high resolution, the following specific technical means can be used. . (1) The coercive force of one of the pair of magnetic layers forming the magnetoresistive film having the multilayer structure is reduced, and the difference of the coercive force from the other magnetic layer is increased. (2) The easy magnetization directions of the pair of magnetic layers forming the magnetoresistive film having the multilayer structure are orthogonal to each other. (3) The anisotropic dispersion angle of at least one of the pair of magnetic layers forming the magnetoresistive film having the multilayer structure is 1
It is set to 0 ° or less. (4) At least one of the pair of magnetic layers forming the multi-layered magnetoresistive film has a single domain structure. (5) The laminated portion of the pair of magnetic layers and the insulating layer forming the multi-layered magnetoresistive film is sandwiched between magnetic materials having high magnetic permeability.

As described above, the element structure is such that the current flowing in the multi-layered magnetoresistive effect film always passes through the intermediate layer forming the magnetoresistive effect film. By forming it on a conductor made of magnetic metal, it is possible to form an element in which a magnetic field in a narrow area can be detected. That is, by forming at least a part of the magnetoresistive effect film on a conductor made of a nonmagnetic metal that is an electrode, the film surface directions of all the magnetic layers forming the magnetoresistive effect film are changed to the magnetic recording medium surface. It is possible to make an element structure that is opposed at a substantially right angle to.
For this reason, the area of the magnetic layer at the end face portion of the magnetoresistive film facing the magnetic recording medium can be made extremely small, so that the magnetic field in a narrow region can be detected with high sensitivity. And as a magnetoresistive film having a multilayer structure,
There are (1) a magnetic thin film using the ferromagnetic tunnel effect, and (2) a magnetic thin film using an antiferromagnetic intermediate layer.
Any of these can be applied to the element structure of the present invention.

Further, of the pair of magnetic layers forming the magnetoresistive film having the multi-layered structure of the present invention, for example, one of the magnetic layers has a leakage magnetic field strength of approximately the same so that the magnetization direction can be changed by the leakage magnetic field from the medium. Set the coercive force. The other magnetic layer has a sufficiently high coercive force so that the magnetization direction does not change even when a leakage magnetic field is applied from the medium. By thus setting the coercive force of the pair of magnetic layers, it becomes possible to obtain a reproduction output that exceeds that of the conventional inductive thin film head or magnetoresistive head. Further, in the magnetic layer whose magnetization direction changes due to the leakage magnetic field from the medium, it is necessary to reduce the anisotropic dispersion angle and make it into a single magnetic domain so that the magnetization rotation occurs at the same time. If this condition is satisfied, the reproduction sensitivity and stability can be improved. In addition, the total thickness of the multi-layered magnetoresistive effect film composed of a pair of magnetic layers and insulating layers is narrower than the shortest recording bit length written to the medium, and the multi-layered magnetoresistive effect film is formed into a pair of high-resistivity films. With the structure sandwiched by magnetic permeability films, the reproduction resolution can be further improved. Further, by narrowing the junction area between a pair of magnetic layers forming the magnetoresistive film having a multi-layer structure, the probability of occurrence of defects (pinholes) in the insulating layer can be reduced and the reproduction sensitivity can be further improved.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, one embodiment of the present invention will be described in more detail with reference to the drawings. <Embodiment 1> An ion beam sputtering apparatus was used for producing a magnetoresistive film and a Cu electrode used for a magnetoresistive effect element. Sputtering was performed under the following conditions. Ion gas ...... Ar Ar gas pressure in the apparatus ・ ・ ・ 2.5 × 10 ^-2 Pa Accelerating voltage of ion gun for vapor deposition ・ ・ ・ 400V Ion current for vapor deposition ・ ・ ・ Ion current ・ ・ ・ 60mA Target substrate distance ・ ・ ・ 127mm Magnetic resistance by ion milling method The effect film and the Cu electrode were processed into a device shape. 70 made by Corning on the board
59 glass was used.

FIG. 1 shows an example of the structure of the magnetoresistive effect element of the present invention. The manufacturing process of the magnetoresistive effect element shown in FIG. 1 will be described below. First, a Cu thin film is formed on a glass substrate by an ion beam sputtering method, and is processed into a rectangular Cu electrode 1 having a width of 8 μm and a length of 2 mm by the ion milling method. The step created by the processing was flattened with resin. On top of that, by the ion beam sputtering method,
Fe-1.3 at% Ru alloy layer 2 having a film thickness of 100 nm, film thickness 10
An SiO ₂ layer 3 having a thickness of 100 nm and a Fe-1.0 at% C alloy layer 4 having a thickness of 100 nm are sequentially laminated. These layers are processed into a magnetoresistive film 5 by ion milling into a rectangle having a width of 5 μm and a length of 20 μm. The step created by this processing was flattened with resin. Further, a Cu thin film is formed thereon by an ion beam sputtering method, and the width is 8 μm and the length is 2 mm.
To form a rectangular Cu electrode 6. A current is caused to flow between the Cu electrode 1 and the Cu electrode 6, and the change in electric resistance is detected by measuring the change in voltage between them. Note that the current passes through the SiO ₂ layer 3.

Using a Helmholtz coil, a magnetic field was applied in the longitudinal direction of the magnetoresistive effect film 5 to examine the change in electric resistance. The relationship between the magnetic field and the change in electrical resistance is shown in FIG. As shown in the figure, the electric resistance of the element changes depending on the strength of the magnetic field. The maximum resistance change rate was about 1%. This is almost the same value as the Ni / NiO / Co multilayer film described in the above cited document, but the value of the magnetic field at which the electric resistance is maximum is lower in the magnetoresistive effect element of the present invention. This is extremely advantageous when applied to a magnetic head. The cause of this change in electrical resistance is considered as follows. From the measurement of the magnetization curve, the coercive force of Fe-1.3 at% Ru alloy layer 2 is 2
It was found that the coercive force of the 5 Oe, Fe-1.0 at% C alloy layer 4 was 8 Oe. When the magnitude of the magnetic field is changed,
At 8 Oe, the magnetization direction of the Fe-1.0 at% C alloy layer 4 changes, but the magnetization direction of the Fe-1.3 at% Ru alloy layer 2 does not change. When a magnetic field of 25 Oe or more is applied, the magnetization direction of the Fe-1.3 at% Ru alloy layer 2 changes. Therefore, in the magnetic field of ± 8 to 25 Oe, Fe-1.
The magnetization direction of the 0 at% C alloy layer 4 and the magnetization direction of the Fe-1.3 at% Ru alloy layer 2 are antiparallel to each other. Moreover, the directions of magnetization are parallel except in this magnetic field range. SiO
_{When a} tunnel current flows through the _two layers 3, the conductance is higher when the magnetization directions of the magnetic layers are parallel to each other than when the magnetization directions of the magnetic layers are antiparallel to each other. Therefore, it is considered that the electric resistance of the element changes depending on the magnitude of the magnetic field.

Next, a ferromagnetic tunnel element having a conventional shape was formed. This has a width of 5μ, as shown in FIG.
Fe-1.3at% Ru alloy layer 2 having a thickness of 100 m and a thickness of 100 nm, a thickness of 1
0 nm SiO ₂ layer 3, Fe-1.
It was composed of 0 at% C alloy layer 4. Fe-1.3at% Ru
The alloy layer 2 and the Fe-1.0 at% C alloy layer 4 are orthogonal to each other.

In the magnetoresistive effect element having the above-mentioned conventional shape, since the magnetic layer used is the same as the magnetoresistive effect element of the present invention described above (FIG. 1), the electric resistance change depending on the magnitude of the magnetic field. Was almost the same as the device of FIG. When the magnetic field from the magnetic recording medium is detected by these elements, the magnetoresistive element of the present invention (FIG. 1) has a width of 5 μm.
A track width of 5 μm is obtained by making the end portion of a rectangular magnetoresistive film 5 having a length of 20 μm and a magnetic recording medium face each other.
You can read the record. However, in the magnetoresistive effect element having the conventional shape (FIG. 12), the tunnel junction portion 7 that strongly participates in the magnetoresistive effect has the Fe-1.0 at% C alloy layer 4
And Fe-1.3 at% Ru alloy layer 2 in the central portion, and cannot face the magnetic recording medium.

Therefore, a magnetoresistive effect element having a conventional structure shown in FIG. 13 was formed. This has a width of 5 μm and a film thickness of 100 n
Fe-1.3 at% Ru alloy layer 2 of m, SiO _{2 of} 10 nm thickness
The layer 3 was composed of a Fe-1.0 at% C alloy layer 4 having a width of 5 μm and a film thickness of 100 nm. The Fe-1.0 at% C alloy layer 4 is cut at the tunnel junction 7 so that the tunnel junction 7 can face the magnetic recording medium. However,
In the three-structure, the Fe-1.3 at% Ru alloy layer 2 also faces the magnetic recording medium in the longitudinal direction and is affected by the leakage magnetic field from the magnetic recording medium. Therefore, even if the width of the Fe-1.0 at% C alloy layer 4 is 5 μm, the effective track width is much larger than 5 μm.

As described above, as in the element structure of the present invention, at least a part of the magnetoresistive film is formed on the non-magnetic metal conductor, and the magnetoresistive effect is made so that all of the flowing current passes through the intermediate layer. By arranging the films in a straight line, the longitudinal (film surface) direction of all the magnetic layers of the magnetoresistive film can be arranged substantially at right angles to the magnetic recording medium surface. it can. Therefore, the area of the magnetic layer located on the end face portion of the magnetoresistive film facing the magnetic recording medium can be made extremely small, and the leakage magnetic field in a narrow region can be detected with high sensitivity.

In this embodiment, the magnetic layer is
The Fe-1.3 at% Ru alloy layer 2 and the Fe-1.0 at% C alloy layer 4, and the SiO ₂ layer 3 as the intermediate layer were used, but other magnetic materials were used as the magnetic layer and other insulating materials were used as the intermediate layer. It goes without saying that the same effect can be obtained by using a material. <Embodiment 2> A magnetoresistive effect element having the structure shown in FIG. 3 was manufactured by the same method as in Embodiment 1. The manufacturing procedure of this magnetoresistive effect element will be described below. First, on a rectangular Cu electrode 1 having a width of 8 μm and a length of 2 mm, a width of 5 μm and a length of 8 μm.
An Fe-1.3 at% Ru alloy layer 2 having a thickness of 100 nm and a thickness of 100 nm is formed. Next, the SiO ₂ layer 3 is formed so as to cover the Fe-1.3 at% Ru alloy layer 2 entirely. In addition, further, SiO ₂
Fe with a width of 5 μm and a thickness of 100 nm so as to cover the entire layer 3
-1.0 at% C alloy layer 4 is formed. Current is Cu electrode 1
And Fe-1.0 at% C alloy layer 4, and the voltage between them is measured.

Also in the magnetoresistive effect element shown in FIG.
All the electric currents passed through the intermediate layer can effectively utilize the magnetoresistive effect. Further, the magnetoresistive effect films can be arranged in a straight line so that the longitudinal (film surface) direction of all the magnetic layers at the end face portion of the magnetoresistive effect film is perpendicular to the magnetic recording medium surface. For this reason, the area of the magnetic layer at the end face portion of the magnetoresistive film facing the magnetic recording medium can be made extremely small, and the magnetic field in a narrow region can be detected with high sensitivity.

Further, as an element having the same effect as that of the magnetoresistive effect element shown in FIG. 3, a structure as shown in FIG. 4 can be considered. This is Fe-on the Cu electrode 1 having a large area.
1.3 at% Ru alloy layer 2, SiO ₂ layer 3, Fe-1.0 at%
The C alloy layer 4 is formed. Fe-1.3 at% Ru alloy layer 2,
The SiO ₂ layer 3 and the Fe-1.0 at% C alloy layer 4 are all Cu.
It is formed on the electrode 1. Further, the Cu electrode 6 is formed so as to fill the step with resin or the like and contact the Fe-1.0 at% C alloy layer 4.

In this embodiment, the magnetic layer is
The Fe-1.3 at% Ru alloy layer 2 and the Fe-1.0 at% C alloy layer 4, and the SiO ₂ layer 3 as the intermediate layer were used, but other magnetic materials were used as the magnetic layer and other insulating materials were used as the intermediate layer. The same effect can be obtained by using a material. <Embodiment 3> The magnetoresistive effect film 5 of the magnetoresistive effect element shown in FIG. 1 is a Fe (3 nm) / Cr (1 nm) multilayer film (film thickness 1
00 nm). Using a Helmholtz coil, a magnetic field was applied in the longitudinal direction of the magnetoresistive effect film 5, and changes in electric resistance were examined. Also in the element of the present embodiment, the electric resistance of the element changed depending on the strength of the magnetic field, and the maximum resistance change rate was about 10%. <Embodiment 4> In the present embodiment, a method of manufacturing a reproducing magnetic head using the magnetoresistive effect element according to the present invention, a result of measuring a resistance change rate, and a recording signal actually written in a magnetic recording medium will be described. The result of comparing the read sensitivity in reading with a conventional magnetoresistive (MR) head and an inductive thin film head will be described.

5 (a), 5 (b) and 5 (c) are process drawings for explaining a method of manufacturing a head. First, on the substrate 8,
The Cu layer to be the lower electrode 9 was formed by the sputtering method.
On top of this, as a material with a high coercive force Hc, Hc = 2000
The Coe—Ni system magnetic layer of Oe is formed by sputtering with a thickness of 0.1 μm to form the lower magnetic pole 10. The lower magnetic pole 10 is formed by sputtering the above magnetic layer and then patterning it in a length of 3 μm and a width of 3 μm by a normal photoresist process.
Then, Al ₂ O ₃ is deposited as the insulating layer 11 by 50 Å by the same sputtering method as described above. After this, the upper magnetic pole 1
2, saturation magnetic flux density Bs = 2.0T, coercive force 0.3 O
e, a magnetic layer made of a Fe-based alloy having an anisotropic dispersion angle of 5 ° or less is also formed by the sputtering method. In the present embodiment, Fe-C alloy is used for the top pole 12. It should be noted that this magnetic layer must be made into a single magnetic domain to stabilize the reproducing characteristics. Therefore, the BN intermediate layer is inserted in the magnetic layer. The upper magnetic pole 12 is patterned to have a size of 2 μm in length and width. After patterning, a resist 13 is applied on the top pole 12 to form a through hole. Then, the upper electrode 14 for supplying a current to the upper magnetic pole 12 is formed, and the process is completed.

The hysteresis characteristics of the device thus manufactured are shown in FIG. As is clear from the figure, the difference in coercive force between the pair of magnetic layers is clearly observed. Among the pair of magnetic layers, the magnetic layer having the smaller coercive force is 50 Oe, and the higher one is 400 Oe. Also, 50
It can be seen that in the range of Oe to 400 Oe, the magnetization amount of the magnetic layer hardly changes even if the external magnetic field changes, and the magnetization changes of the pair of magnetic films are completely separated. The difference in coercive force between the pair of magnetic layers can be set to an appropriate value depending on the coercive force and saturation magnetization of the medium used, so that the reproducing sensitivity to an external magnetic field can be improved. Moreover, the result of measuring the resistance change with respect to the uniformly applied magnetic field is shown in FIG. The measurement was performed at room temperature, but the rate of change in resistance Δρ / ρ
Showed a high value of 5%. Although the angle formed by the anisotropy of the pair of magnetic layers was 90 degrees, the external magnetic field was applied in the anisotropic direction of the magnetic layer having a high coercive force.

Next, FIG. 8 shows the results of measuring the change in resistance change rate while gradually decreasing the anisotropic dispersion angle from 70 degrees. As a result, it was confirmed that the smaller the anisotropic dispersion angle, the more preferable the result. However, in the current technology, the anisotropic dispersion angle is limited to about 5 degrees, and the resistance change rate Δρ / ρ becomes 5% at this time. However, if the anisotropic dispersion angle can be suppressed to around 10 degrees, the rate of resistance change will be 4.8%.
Since it can be set as described above, the anisotropic dispersion angle is set between 5 degrees and 10 degrees in the present embodiment. Next, one direction of the sample was scraped off by mechanical polishing, and a normal thin film head was pressed against the polishing surface, and the resistance change rate in the high frequency region was also measured. The results are shown in FIG. 9, and it was confirmed that the resistance change rate was almost flat up to the frequency of 30 MHz.

Next, the recording / reproducing separated type head in which the device of this embodiment was formed on an inductive type thin film head was prototyped and the reproducing characteristics were measured. The sectional structure of this recording / reproducing separated type head is shown in FIG. Here, in order to improve the resolution with respect to the external magnetic field, the shield layers 15 and 16 are provided on both sides of the multilayer film formed by the pair of magnetic layers and the non-magnetic intermediate layer. The distance between the shield layers 15 and 16 is 0.3 μm. This magnetic head has a coercive force of 2000
The reproduction characteristics were measured in combination with Oe and a sputter medium having a film thickness of 500Å, and the results were compared with those of an induction type thin film head and an MR head. FIG. 11 shows the results of comparing the reproduction sensitivities of the respective heads, with the horizontal axis representing the recording density and the vertical axis representing the reproduction output per unit track width. Measurement is spacing 0.1
The reproduction output obtained by the magnetic head according to the embodiment of the present invention is 2.5 times that of the induction type head.
It was about 1.3 times as high as that of the MR head, and no reproduction output fluctuation as measured by the MR head was observed.

[0026]

As described in detail above, in the magnetic layer,
In a magnetoresistive effect element of the present invention using a multi-layered magnetoresistive effect film formed by inserting an intermediate layer made of an insulator, a semiconductor, or an antiferromagnetic material, all currents flowing through the magnetoresistive effect film have the above-mentioned intermediate value. By making the element structure such that it can pass through the layers without fail, and by forming the element structure in which at least a part of the magnetoresistive effect film is formed on a conductor made of a nonmagnetic metal, the film of all magnetic layers of the magnetoresistive effect film is formed. Since the surface direction can be arranged substantially perpendicular to the surface of the magnetic recording medium to detect the magnetic field, the area of the magnetic layer at the end face portion of the magnetoresistive film facing the magnetic recording medium can be made extremely small. Therefore, it is possible to detect a leakage magnetic field from a narrow region from a narrow track high-density magnetic recording medium with high sensitivity. The magnetoresistive effect film having the above-mentioned multilayer structure can be any type of magnetoresistive effect film including (1) a magnetic thin film using a ferromagnetic tunnel effect and (2) a magnetic thin film using an antiferromagnetic intermediate layer. Can also be applied,
The utility value of the present invention is extremely wide.

In the reproducing magnetic head using the magnetoresistive element of the present invention, the reproduction output is stable and a signal having a high S / N ratio can be reproduced even if the track width is 2 μm or less. Therefore, it is extremely effective as a head for a magnetic disk device which has a particularly large storage capacity and requires high-speed data transfer.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a configuration of a magnetoresistive effect element exemplified in a first embodiment of the present invention.

FIG. 2 is a graph showing the relationship between the applied magnetic field and the resistance change rate of the magnetoresistive effect element illustrated in the first embodiment of the present invention.

FIG. 3 is a schematic diagram showing a configuration of a magnetoresistive effect element exemplified in the second embodiment of the present invention.

FIG. 4 is a schematic diagram showing another configuration of the magnetoresistive effect element exemplified in the second embodiment of the present invention.

FIG. 5 is a process diagram showing a manufacturing process of the magnetoresistive effect element exemplified in the fourth embodiment of the present invention.

FIG. 6 is a graph showing hysteresis characteristics of the magnetoresistive effect element manufactured by the process of FIG.

7 is a graph showing a resistance change of the element shown in FIG. 5 with respect to a uniform applied magnetic field.

8 is a graph showing the relationship between the anisotropic dispersion angle and the resistance change rate of the device shown in FIG.

9 is a graph showing the relationship between frequency and resistance change rate of the device shown in FIG.

FIG. 10 is a schematic diagram showing a cross-sectional structure of the recording / reproducing separated type head exemplified in the fourth embodiment of the invention.

11 is a graph showing reproduction characteristics of the head shown in FIG. 10 in comparison with a conventional inductive thin film head and an MR head.

FIG. 12 is a schematic diagram showing a configuration of a conventional magnetoresistive effect element.

FIG. 13 is a schematic diagram showing another configuration of a conventional magnetoresistive effect element.

[Explanation of symbols]

1 ... Cu electrode 2 ... Fe-1.3 at% Ru alloy layer 3 ... SiO ₂ layer 4 ... Fe-1.0 at% C alloy layer 5 ... Magnetoresistive film 6 ... Cu electrode 7 ... Tunnel junction 8 ... Substrate 9 ... lower electrode 10 ... lower magnetic pole 11 ... insulating layer 12 ... upper magnetic pole 13 ... resist 14 ... upper electrode 15 ... shield layer 16 ... shield layer 17 ... insulating layer 18 ... magnetic flux detector 19 ... recording coil 20 ... recording magnetic pole 21 ... Magnetic recording medium

[Procedure amendment]

[Submission date] June 13, 2002 (2002.6.1)
3)

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Correction content]

[Claims]

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Naoki Koyama             1-280, Higashi Koikekubo, Kokubunji, Tokyo             Central Research Laboratory, Hitachi, Ltd. (72) Inventor Yuu Yuto             1-280, Higashi Koikekubo, Kokubunji, Tokyo             Central Research Laboratory, Hitachi, Ltd. (72) Inventor Kimi Takano             1-280, Higashi Koikekubo, Kokubunji, Tokyo             Central Research Laboratory, Hitachi, Ltd. (72) Inventor Hidetoshi Moriwaki             1-280, Higashi Koikekubo, Kokubunji, Tokyo             Central Research Laboratory, Hitachi, Ltd. (72) Inventor Mikio Suzuki             1-280, Higashi Koikekubo, Kokubunji, Tokyo             Central Research Laboratory, Hitachi, Ltd. (72) Inventor Masaaki Nihon             1-280, Higashi Koikekubo, Kokubunji, Tokyo             Central Research Laboratory, Hitachi, Ltd. (72) Inventor Fumio Kugiya             1-280, Higashi Koikekubo, Kokubunji, Tokyo             Central Research Laboratory, Hitachi, Ltd. (72) Inventor Yoshifumi Matsuda             1-280, Higashi Koikekubo, Kokubunji, Tokyo             Central Research Laboratory, Hitachi, Ltd. (72) Inventor Kazuo Shiiki             1-280, Higashi Koikekubo, Kokubunji, Tokyo             Central Research Laboratory, Hitachi, Ltd. F-term (reference) 5D034 BA03 BB08 CA06                 5E049 AA01 AA04 AA07 BA12

Claims (14)

[Claims] 1. A magnetoresistive effect element using a magnetoresistive effect film having a multilayer structure formed by inserting an intermediate layer made of an insulator, a semiconductor or an antiferromagnetic material into a magnetic layer, wherein the magnetoresistive effect film is A magnetoresistive effect element having a structure in which all the flowing current passes through the intermediate layer. 2. A magnetoresistive effect element according to claim 1, wherein at least a part of the magnetoresistive effect film is formed on a conductor made of a nonmagnetic metal. 3. A claim according to claim 1 or 2,
A magnetoresistive effect element comprising a magnetic layer and an intermediate layer constituting a multi-layered magnetoresistive effect film laminated in the same film plane. 4. A magnetoresistive effect element according to claim 1, wherein the magnetoresistive effect film has a ferromagnetic tunnel effect. 5. The magnetoresistive film having a ferromagnetic tunnel effect according to claim 4, wherein the magnetoresistive film is Ni / NiO / Co,
_{Fe / Ge / Co, Al /} Al 2 O 3 / Ni, Co-Al /
Al ₂ O ₃ / Ni, Fe-C / SiO ₂ / Fe-Ru, Fe-
_{C / Al 2 O 3 / Co} -Ni, Fe-C / Al 2 O 3 / Fe
A magnetoresistive effect element characterized by being one of -Ru. 6. The magnetoresistive effect element according to claim 1, wherein the magnetoresistive effect film is a multilayer film having an intermediate layer made of an antiferromagnetic material. . 7. A magnetoresistive effect element according to claim 6, wherein the multilayer film having an intermediate layer made of an antiferromagnetic material is a Fe / Cr multilayer film. 8. A magnetic flux leakage signal from a high-density magnetic recording medium having a narrow track, which is highly sensitive, using the magnetoresistive element according to any one of claims 1 to 7. A magnetic head comprising a reproducing magnetic head for detecting and reading recorded information. 9. A magnetic head for detecting a signal magnetic flux leaking from a magnetic recording medium by utilizing a ferromagnetic tunnel phenomenon of a magnetoresistive film composed of magnetic layers laminated with an insulating layer interposed therebetween. A magnetic head characterized in that the coercive force of the magnetic layers laminated via the different layers is different. 10. The magnetic head according to claim 9, wherein the magnetic layers having different coercive forces are made of a soft magnetic material and a hard magnetic material. 11. The magnetic head according to claim 9 or 10, wherein the easy magnetization directions of the magnetic layers laminated with the insulating layer interposed therebetween are substantially orthogonal to each other. 12. A magnetic head according to any one of claims 9 to 11, wherein the magnetic layer laminated with an insulating layer interposed therebetween has a multi-layer structure. 13. The magnetic layer according to any one of claims 9 to 12, wherein the magnetic layers laminated via an insulating layer are sandwiched by magnetic shield materials. And a magnetic head. 14. A leakage magnetic flux signal from a high density recording medium is detected by using the reproducing magnetic head according to any one of claims 8 to 13 and recorded on the magnetic recording medium. A magnetic recording / reproducing apparatus provided with means for reading the stored information.