JPH09245318A - Magnetoresistive head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize electromagnetic conversion characteristics and to decrease Barkhausen noises and surge fluctuations by forming permanent magnet films thinly at both ends of a magnetoresistance effect element. SOLUTION: The central active region of the magnetoresistive head is composed of an MR film 3, a SAL 1 which is a soft bias film for impressing a transverse bias and a separating film 2 for separating two magnetic films. The end passive regions impart a longitudinal bias to the central active region. The permanent magnet film 7 is formed thinner than the total of the SAL 1, the separating film 2 and the MR film 3 after the SAL 1, the separating film 2 and the MR film 3 are formed to the prescribed shape after the formation of the MR film 3 to the prescribed shape. A taper is formed at the permanent magnet film in such a manner that the film remains at the end with the MR film 3 by removing the film so as not to remain in the part of the MR film 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel magnetoresistive effect magnetic head and a magnetic recording / reproducing apparatus using the same.

[0002]

2. Description of the Related Art A head having a structure in which two magnetic layers are separated by a nonmagnetic layer and an exchange bias magnetic field from an antiferromagnetic layer is applied to one magnetic layer has been devised. Is a function of the angle θ between the magnetizations of the two magnetic layers,
The effect that changes in proportion to cos θ is called the giant magnetoresistive effect. It is known that a magnetoresistive head using a giant magnetoresistive effect by such a multilayer film exhibits a large magnetoresistive change amount ΔR as compared with a conventional head using an anisotropic magnetoresistive effect. However, a problem of the giant magnetoresistive head is suppression of Barkhausen noise. If a magnetic wall is included in the magnetoresistive film and the magnetization state is unstable, large noise is generated. It is well known for AMR heads that it is effective to apply a so-called "longitudinal bias magnetic field" to the magnetoresistive film in the track width direction in order to suppress this noise. Even in the giant magnetoresistive head,
A method of applying a longitudinal bias in order to stabilize the magnetization state of the free side magnetic layer is disclosed in JP-A-4-358310. According to this, a ferromagnetic or antiferromagnetic film is laminated on both ends of the magnetic film, and a longitudinal bias magnetic field is applied by exchange coupling with this film and the magnetic film of the magnetic sensing part to stabilize the magnetization state.

In a magnetoresistive effect type magnetic head, in order to apply a lateral bias magnetic field to a level sufficient to make the magnetoresistive effect film highly sensitive, a soft magnetic film (hereinafter referred to as a bias film) is adjacent to the magnetoresistive effect film. The structure for disposing the above) is already known. Although this bias film is magnetically separated from the magnetoresistive film by the nonmagnetic layer, it electrically forms a circuit in parallel with the magnetoresistive film, thus increasing the output of the magnetoresistive head. To do so, it is necessary to further increase the electric resistance of the bias film.

Japanese Patent Application No. 60-159518 discloses a magnetoresistive effect magnetic head in which a bias film is an amorphous soft magnetic film.

Further, as a magnetic thin film obtained by adding a compound to a metal magnetic alloy, Japanese Patent Laid-Open No. 60-170213 discloses that one or more alloys of iron, cobalt and nickel have a greater affinity for oxygen than these metals. It is stated that the metal partial oxide thin film has a large coercive force in the direction perpendicular to the substrate. Further, Japanese Patent Application Laid-Open No. 63-164406 discloses a magnetic head having a single phase of a composition comprising a nickel-iron alloy and a compound composed of a metal and a nonmetal which can be simultaneously vapor-deposited without producing a precipitate. A magnetic thin film for a magnetic pole has been disclosed, and it is stated that the wear resistance of the magnetic pole is improved by using such a magnetic thin film for the magnetic pole piece.

[0006]

The magnetic head utilizing the giant magnetoresistive effect, which has been conventionally proposed as described above, has a long hem of the sensitivity distribution in the track width direction, so that it is adjacent to a reproducing head at a high track density. There was a problem that the crosstalk from the track was large.

Further, even when a longitudinal bias film is provided for controlling magnetic domains, if there is a portion overlapping with the magnetic layer, the magnetic field changes abruptly at the portion where the end of the hard magnetic layer and the magnetic layer of the magnetic sensitive portion overlap. Therefore, an irregular magnetized state such as a domain wall is likely to occur in the vicinity, which causes Barkhausen noise and fluctuations in the output waveform.

As described above, the bias film needs to be made of a material having a large electric resistance, a small coercive force, and a saturation magnetic flux density that is large to some extent in order to apply a sufficient lateral bias magnetic field. The lateral bias magnetic field is an important parameter that determines the sensitivity of the magnetoresistive head and the linearity of the reproduced waveform.There is little variation in the magnetic characteristics of the bias film, and the magnitude of the lateral bias magnetic field does not change. is necessary.

When an amorphous film is used as the bias film, the amorphous film has a large electric resistance as is well known, so that it is expected that the reproducing voltage of the head is improved. However, when an amorphous alloy film is used as the bias film, it is difficult to stabilize the soft magnetic characteristics of the film because the amorphous state is essentially a metastable state. The magnetic characteristics of the amorphous film are likely to change due to the application of a strong magnetic field or the temperature rise, and the magnetic characteristics may change during the head processing process. Further, the magnetic thin film described in JP-A-60-170213 is a magnetic thin film having a large perpendicular coercive force, and the magnetic thin film described here cannot be used as a bias film.

The magnetic thin film described in JP-A-63-164406 is a wear-resistant thin film for a magnetic pole of a magnetic head,
Although it is considered to be sufficient as a bias film in terms of magnetic properties, nothing is mentioned about the electric resistance of this thin film.

An object of the present invention is to provide a magnetoresistive head using the giant magnetoresistive effect and having high output and less noise, and a magnetic recording / reproducing apparatus using the same.

[0012]

According to the present invention, there are provided a magnetoresistive film whose electric resistance is changed by a magnetic field, a lateral bias film for applying a lateral bias magnetic field to the magnetoresistive film, the magnetoresistive film and the lateral bias film. And a pair of permanent magnet films for applying a longitudinal bias to the magnetoresistive effect film provided in contact with both ends of the magnetoresistive effect film and having a separation film provided between A pair of electrode films provided on the permanent magnet film for supplying a signal detection current to the magnetoresistive film, the thickness of the permanent magnet film being smaller than the thickness of the magnetoresistive element film. It is in a magnetoresistive head.

The permanent magnet film is a Co--Pt alloy, Co--
Cr-Pt alloys or these alloys may include Ti oxide, V oxide, Zr oxide, Nb oxide, Mo oxide, Hf oxide, Ta oxide, W oxide, Al oxide, Si oxide,
Those made of any of alloys containing at least one element of Cr oxides are preferable.

It is preferable that the permanent magnet film has a composition of (Equation 1) or (Equation 2).

[0015]

[Equation 3] Co _a Cr _b Pt _c or ... (Equation 1)

[0016]

(Equation 4) (Co _a Cr _b Pt _c ) _1-x (MO _y ) _x (Equation 2) (where x = 0.01 to 0.20, y: 0.4 to 3, a:
0.7-0.9, b: 0-0.15, C: 0.03-0.1
5, M: Ti, V, Zr, Mo, Hf, Ta, W, A
At least one of l, Si, and Cr) The present invention relates to a magnetoresistive film whose electric resistance changes according to a magnetic field, and a lateral bias film formed of a soft magnetic film for applying a lateral bias magnetic field to the magnetoresistive film. A separation film made of a non-magnetic film for magnetically separating the lateral bias film and the magnetoresistive film; and the magnetoresistive film provided in contact with both ends of the magnetoresistive film, the lateral bias film and the separation film. For applying a transverse bias magnetic field to the magnetoresistive effect film, which comprises a permanent magnet film for applying a longitudinal bias magnetic field and a pair of electrodes for supplying a current to the magnetoresistive effect film provided on the permanent magnet film. Soft magnetic film of nickel-iron alloy, cobalt, one kind of nickel-iron-cobalt alloy, zirconium oxide, aluminum oxide, hafnium oxide, titanium oxide, beryllium oxide, magnesia oxide. A magnetic material comprising one or more compounds selected from the group consisting of um, rare earth oxygen compounds, zirconium nitride, hafnium nitride, aluminum nitride, titanium nitride, beryllium nitride, magnesium nitride, silicon nitride, and rare earth nitrogen compounds. It is in a resistance effect type magnetic head.

It is preferable that the soft magnetic thin film for applying a transverse bias magnetic field to the magnetoresistive film has a specific resistance of 70 μΩcm or more.

The lateral bias film contains nickel of 78 to 84.
Those composed of nickel-iron based alloys having atomic% are preferred.

According to the present invention, a pair of permanent magnet films provided on a substrate, a pair of electrodes formed on each of the permanent magnet films, and a magnetoresistive effect element provided between the permanent magnets. A magnetoresistive effect magnetic head having a film,
In the magnetoresistive effect magnetic head, the element film includes an antiferromagnetic film made of nickel oxide, two ferromagnetic films, a nonmagnetic metal film, and a soft magnetic film, which are sequentially formed from the substrate side. is there.

The two-layered ferromagnetic film is made of Ni from the substrate side.
It is preferably composed of a 70 to 95 atomic% iron alloy layer and a Co layer.

The two layers of ferromagnetic films are preferably composed of a soft magnetic film from the antiferromagnetic side and a soft magnetic film having a larger magnetoresistance change rate than the soft magnetic film.

According to the present invention, a pair of permanent magnet films provided on a substrate, a pair of electrodes formed on each of the permanent magnet films, and a magnetoresistive element provided in contact with the permanent magnets. A magnetoresistive effect magnetic head having a film,
The device is characterized in that an antiferromagnetic film, a ferromagnetic film, a nonmagnetic film, a soft magnetic film, a nonmagnetic film, a ferromagnetic film, and an antiferromagnetic film are sequentially laminated from the substrate side. The effect type magnetic head.

In the present invention, it is preferable to use a Co type magnetic film or a film obtained by adding an oxide thereto as the permanent magnet film arranged in the passive region at the end of the MR sensor. Addition of an oxide to the Co-based magnetic film increases the coercive force of the Co-based magnetic film.

By adding an oxide, the crystal orientation is disturbed and the influence of the underlying film is reduced. The reason why the coercive force is increased by adding an oxide to the Co-based magnetic film is that the magnetic coupling between the crystal grains is blocked by the oxide deposited at the crystal grain boundaries of the permanent magnet film. Therefore, the coercive force of the permanent magnet film whose coercive force is increased by this mechanism is not easily influenced by the underlayer film.

In the present invention, the permanent magnet film is a multi-layer film divided by non-magnetic layers. The coercive force of the single layer Co-based permanent magnet film has a maximum value in the film thickness of 10 nm to 30 nm. Therefore, the permanent magnet film has a multi-layer structure divided by non-magnetic layers. By setting the film thickness of each permanent magnet film to the film thickness that maximizes the coercive force, it is possible to avoid a decrease in the coercive force in a single-layer thick film. Here, the film thickness of the all-permanent magnet film is set so as to give an appropriate bias magnetic field to the central active region.

The present invention is one of nickel-iron alloy, cobalt, nickel-iron-cobalt alloy, zirconium oxide, aluminum oxide, hafnium oxide, titanium oxide,
Beryllium oxide, magnesium oxide, rare earth oxygen compounds, zirconium nitride, hafnium nitride, aluminum nitride, titanium nitride, beryllium nitride, magnesium nitride, silicon nitride, and one or more compounds selected from rare earth nitrogen compounds By using the magnetic thin film as the bias film, a magnetoresistive effect type magnetic head having a large reproduction output can be obtained. Regarding the amount of the compound contained in the bias film, in the magnetoresistive head, the ratio of atoms excluding oxygen or nitrogen of the compound is 3 to 20% with respect to all atoms excluding oxygen and nitrogen. preferable. This is because when the amount of the compound is 3% or less, the increase in the electric resistance is small, and when it is 20% or more, the saturation magnetic flux density is decreased and the value is not sufficient as the bias film.
The specific resistance of the bias film of the present invention increases almost in proportion to the amount of the compound added.
It is preferable to have a specific resistance of 0 μΩcm or more. This is because the output of the magnetoresistive head decreases unless the specific resistance of the bias film is sufficiently larger than the specific resistance of the magnetoresistive film. The specific resistance of the magnetoresistive film is 20 to 3
It is 0 μΩcm, and the resistivity of the bias film is at least twice as large as a standard.

The bias film of the present invention can be produced by a method such as vapor deposition, sputtering method, ion beam sputtering method and the like. The target for sputtering or ion beam sputtering is to mix alloy powder consisting of nickel, iron, cobalt, etc. and compound powder by an appropriate method, sinter and mold, or consist of nickel, iron, cobalt, etc. A target in which a compound chip is arranged on a metal target may be used, and by using such a target, an alloy composed of nickel, iron, cobalt or the like and a compound can be simultaneously deposited.
Further, the bias film of the present invention, in the sputtering device,
A metal target made of nickel, iron, cobalt, etc.,
It can also be made by placing a target of the compound and such that each particle emitted from the target is substantially mixed on the substrate.

The bias film of the magnetoresistive effect type magnetic head is required to have both soft magnetic characteristics and high electric resistance as described above. It is also necessary that their properties do not change during the head fabrication process. In order to increase the electric resistance, other elements are added to the metal, but when the metal element is added to the soft magnetic thin film, the added metal element and the magnetic element are metal-bonded to each other. In many cases, the state changes greatly and the soft magnetic characteristics are impaired. Since the compound contained in the bias film of the present invention has already formed an ionic bond itself, the electric resistance of the film is increased without significantly changing the electronic state of the magnetic metal element, that is, without impairing the soft magnetic property. Can be made. By using the soft magnetic film having a large electric resistance as the bias film as described above, the current shunted to the bias film is reduced and the reproducing voltage of the magnetoresistive head is increased.

Further, since the bias film of the magnetoresistive effect type magnetic head of the present invention is a crystalline alloy, it is thermally stable and the change in magnetic characteristics is small.

The compound contained in the bias film of the magnetoresistive head of the present invention is generally distinguished from impurities which are inevitably formed during film formation. The additive compound of the present invention is substantially present in the form of a compound in the raw material or material for film formation.

The compound of the bias film of the magnetoresistive head of the present invention has a sufficiently large binding energy. Thin films are generally made by condensing atoms from the gas phase in a vacuum system. A compound having a small binding energy is decomposed in an evaporation process or a condensation process, and oxygen and nitrogen generated by the decomposition are combined with a magnetic element to impair the magnetic properties. On the other hand, a compound having a large binding energy such as a compound is not decomposed and is taken into the film as it is. Among the additive compounds of the present invention, the nitrogen compound has a smaller binding energy than the oxygen compound. However, since the binding energies of the magnetic elements nickel, iron, and cobalt with nitrogen are very small, they do not decompose even if the binding energy is smaller than that of the oxide-adding element,
Stable in the membrane.

The metal element such as nickel, iron, cobalt and the compound of the bias film of the magnetoresistive effect magnetic head of the present invention and the compound are uniformly dispersed in the film by simultaneous vapor deposition of these. These metal elements and compounds are hardly mixed in the bulk state, but they are uniformly dispersed by simultaneous vapor deposition as in the production method of the present invention, and exhibit good soft magnetic characteristics.

The magnetic recording / reproducing apparatus using the magnetoresistive magnetic head of the present invention is preferably used by being connected to an external device such as a computer, and the signal for magnetically retaining the signal is magnetically stored. A recording medium, an electromagnetic conversion structure that moves relative to the recording medium, a means for rotating the recording medium, and a means for moving the electromagnetic conversion structure to a predetermined position on the recording medium. It is preferable to have More preferably, it also has an interface circuit for connecting to an external information processing device and a circuit for processing a signal stored in a recording medium.

The recording medium mounted in the present invention is a so-called magnetic disk, which has a magnetic film for magnetically storing signals, a substrate, a protective film and the like, and is recorded on the recording medium. The magnetic signal may be recorded parallel to the recording medium surface or perpendicular to the recording medium surface. The magnetic film of the recording medium needs to have a coercive force enough to magnetically retain a signal.

The magnetoresistive effect element mounted in the magnetic recording / reproducing apparatus of the present invention has a substrate, an antiferromagnetic film, and a magnetic layer in a direction in which the magnetoresistive element is driven relative to the recording medium, that is, in a direction parallel to the recording medium. It is characterized in that a film, a non-magnetic conductive film, a soft magnetic film, a non-magnetic conductive film, a magnetic film, and an antiferromagnetic film are laminated.

Nickel oxide is preferably used for the antiferromagnetic film, and in addition to this, an iron-manganese alloy thin film, chromium manganese, a chromium aluminum alloy film or the like is used.

As the permanent magnet film which is the hard magnetic film in the present invention, the above-mentioned cobalt-platinum alloy film or iron-cobalt terbium alloy film is used. The hard magnetic film is a magnetic film whose magnetization is hard to change with respect to an external magnetic field, and its coercive force is, for example, 100 Oersted or more. Even if a magnetic field of 50 Oersted is applied, the direction of the magnetization hardly changes. Therefore, it has the same effect as the antiferromagnetic film. That is, when it is formed in close contact with another magnetic film, it has a characteristic that unidirectional anisotropy due to an exchange coupling bias can be applied, and a longitudinal bias magnetic field is formed in the magnetoresistive effect film.

The magnetic film contains Ni of 70 to 95 atomic%,
An alloy containing 5 to 30 atomic% of Fe and 1 to 5 atomic% of Co, or 30 to 85 atomic% of Co, 2 to 30 atomic% of Ni and Fe2
It is preferable to use an alloy of up to 50 atom%.
Permalloy, permender alloy, etc. may be used. That is, it is preferable to use a ferromagnetic material having a good soft magnetic characteristic.

The non-magnetic conductive film is made of Au, Ag, Cu.
It is preferable to use Cr, Pt, Pd,
You may use Ru, Rh, etc. or these alloys. That is, it is preferable to use a material that does not have spontaneous magnetization at room temperature and has good electron permeability. It is preferable that each of the above films has a film thickness of about 2 to 1000 Å.

An extremely thin nonmagnetic insulating film can be used instead of the nonmagnetic conductive film. That is, this film is sufficient as long as electrons can move between the magnetic films. Therefore, for example, the tunnel effect may be used. In this case, the non-magnetic insulating film needs to be thin to a certain degree so that electrons can be tunneled.
It is formed to be 00 Å or less, substantially 50 Å or less. As means for forming the above, surface oxidation of the soft magnetic film, or
It is preferable to use an oxide film on the surface of a metal film, for example, aluminum, which is separately formed on the soft magnetic film, as the non-magnetic insulating film. Alternatively, an aluminum oxide film or the like may be formed and used. That is, it is preferable to use a material having a characteristic of blocking magnetic coupling between the magnetic films.

Further, the substrate may be an underlayer for forming these films and has a function as a slider of a magnetic disk device.
%, A ceramic sintered body such as alumina containing stabilized TiC or less, stabilized zirconia, or the like is preferable.

By having such a film structure, the magnetoresistive effect element has a function of changing its electric resistance with respect to a weak external magnetic field, and the change rate of its electric resistance is as large as 5% to 10%. Have an effect. Therefore, the magnetic recording / reproducing apparatus of the present invention has a function of directly digitizing a signal recorded in an analog state at the time of reproduction, and further has an effect of increasing the recording capacity per disc area, that is, the recording density.

As the film constitution, a flat film of aluminum oxide, nickel oxide or the like is formed on the substrate, or iron, titanium, tantalum, zirconium, hafnium, niobium, cobalt iron alloy is formed on the substrate. It may be formed by further forming a film such as The film on the substrate has an effect of flatly forming a multilayer film on the surface thereof, and preferably has a uniform and flat film structure on the surface of the substrate, and the thickness of each film is 20 for a metal film.
It is preferable that the thickness is from about 200 to 200Å, and about 5 to 1000Å for a film other than metal.

The film of the magnetoresistive effect element of the present invention has at least a structure of magnetic film / nonmagnetic conductive film / magnetic film. By having a sandwich structure of magnetic films sandwiching such a non-magnetic conductive film, it has a function of causing spin-dependent scattering of electrons at the magnetic film / non-magnetic film interface, and thus, between the two magnetic films. It has an effect of producing a magnetoresistive effect. Further, it has a function of blocking magnetic coupling between the magnetic films, and has an effect of improving the sensitivity of the magnetoresistive effect element to an external magnetic field.

As a result, the magnetic recording / reproducing apparatus of the present invention has a good reproducibility that always obtains the same output for a constant signal, and has an effect of reducing the error rate during reproduction.

The present invention preferably has a film structure of antiferromagnetic film / magnetic film / nonmagnetic conductive film / magnetic film / hard magnetic film, and the thickness of each of the antiferromagnetic film and hard magnetic film is Two
It is preferably about 0 to 2000Å.

The bias film laminated on the MR film other than the permanent magnet film in the present invention is preferably arranged further on the substrate side than the magnetic film and the non-magnetic film, and the surface is flattened to prevent wetting of the laminated film. It is preferable to have a function as a base film to be improved, and the anisotropy makes the magnetic domain structure of the magnetic film into a single magnetic domain, thereby suppressing generation of noise. As a film configuration, it is preferable to have a configuration of first and second magnetic films laminated with a non-magnetic conductive film interposed therebetween and a bias film that is closely formed on the first magnetic film.

As described above, the magnetic field sensor has a structure having the laminated film showing the magnetoresistive effect or the composite laminated body thereof and at least a pair of electrodes electrically contacting each other to measure the electric resistance of the laminated film. And has an effect of detecting a signal on a recording medium with high sensitivity.

In particular, the first bias film, the first magnetic film, the non-magnetic film, the second magnetic film, the non-magnetic conductive film, the third magnetic film, the second bias film and the electrode which are laminated on the substrate. It is preferable that The third magnetic film preferably has the same magnetic function as the first magnetic film.

The bias direction of the bias film and the anisotropy direction of the magnetic film are preferably controlled by appropriately applying a magnetic field according to the forming process when forming the multilayer film of the element. Alternatively, it is preferable to perform heat treatment in a magnetic field during or after the formation of the multilayer film of the element.

With respect to the application of a magnetic field in the formation of the film, it is preferable to control the direction and magnitude of the magnetic field in accordance with the film stacking process to control the bias application direction and the uniaxial anisotropy of the magnetic film. .

Furthermore, when heat treatment is performed in a magnetic field in forming the film, it is preferable to control the anisotropy of the bias film and the uniaxial anisotropy of the magnetic film.

In the case of having a hard magnetic film laminated on the MR film, it is desirable to apply a magnetic field after the device is manufactured to direct the magnetization of the hard magnetic film in a predetermined direction.

The material of the bias film preferably has a high electric resistance, and specifically, the electric resistivity is preferably 5 × 10 ⁻⁴ ohm cm (Ωcm) or more. This bias film prevents the output of the element from decreasing due to current leakage, controls the laminated structure of the materials used, especially the flatness, and enables the element to be laminated. When a nickel oxide (NiO) film, which is substantially an insulator, is used as the bias film, the magnetic field sensitivity is as high as about 10 Oersted, which is about 2 to 4 times higher than the conventional one. A reliable laminated structure can be realized.

In the magnetic recording / reproducing apparatus of the present invention, one magnetic film has means for applying magnetic anisotropy in a direction substantially perpendicular to the recording medium, and the other magnetic film has a means for applying magnetic anisotropy. Is
It is characterized in that it has means for applying a magnetic anisotropy smaller than the magnetic anisotropy in a direction substantially parallel to the surface of the magnetic film with respect to the recording medium. As means for applying anisotropy having a smaller magnitude than the above, shape anisotropy or uniaxial anisotropy of the magnetic film of the magnetoresistive effect film is used, or an appropriate shunt film or soft film is used for the magnetoresistive effect. There are methods such as arranging adjacent to the film or forming another bias film in close contact with the magnetic film.

Further, the magnetic recording / reproducing apparatus of the present invention detects a recording medium for magnetically storing a signal with a predetermined track width, and a magnetic field leaking from the recording medium to detect a magnetic field with a non-magnetic conductive film interposed therebetween. A magnetoresistive effect element having a film sandwich structure and having a pair of electrodes for applying a current to the structure, wherein the length of the structure in a direction perpendicular to the recording medium is The length in the direction parallel to the plane,
Particularly, it is characterized in that it is not more than the length between the electrodes and not more than the track width formed on the recording medium. This is because the shape anisotropy is effectively applied to the portion of the magnetoresistive effect element involved in the reproduction to compensate the output range of the magnetoresistive effect element, and the end portion of a predetermined track due to a tracking error during reproduction. Moreover, there is an effect that the external signal is not read.

Further, the magnetic recording / reproducing apparatus of the present invention has a magnetoresistive effect element for reading a magnetic field from a magnetization pattern written with a predetermined track width on a recording medium, and the recording medium of the element is mounted on the recording medium. On the other hand, the vertical length d
The relationship between (μm) and the density T (tracks / inch) of tracks on the medium is preferably d <12.5 × 10 ³ / T.

Further, the magnetic head of the present invention has a recording medium for magnetically storing signals and a magnetoresistive effect element for detecting a magnetic field leaking from the medium, wherein the element is the medium. A resistance change rate of 5.0 to 8.5% can be obtained with respect to a magnetic field of ± 10 Oe leaked from.

Further, the magnetic recording / reproducing apparatus of the present invention detects a recording medium for magnetically storing signals and a magnetic film sandwich which detects a magnetic field leaking from the recording medium and sandwiches a non-magnetic conductive film therebetween. A magnetoresistive effect element having a structure, wherein the element can obtain a resistance change rate of 5.0 to 9.5% with respect to a magnetic field of ± 8 Oe leaking from the recording medium.

The thin film magnetic head of the present invention is a combination of a substrate, an inductive recording head for recording a signal, and a magnetoresistive effect reproducing head for reproducing a signal, wherein the reproducing head is a non-magnetic head. The recording head has a sandwich structure of magnetic films sandwiching a magnetic conductive film, and the recording head is formed between the substrate and the reproducing head. The present invention can reduce the decrease in sensitivity due to the increase in the shape anisotropy of the magnetic film in the magnetoresistive effect element. This can be reduced by thinning the magnetic film. This is because the shape anisotropy of the magnetic film is approximately proportional to its thickness. On the other hand, the total thickness of the magnetoresistive film of the present invention is 100 to 3 in order to prevent a decrease in output due to surface scattering.
The thickness of each magnetic film separated by a non-magnetic film, especially the soft magnetic film at the center of the film is 100Å
This is because, even if it is 10 to 20 Å or less, the output does not decrease at all. This action is caused by the mechanism of manifestation of the magnetoresistive effect due to the interface of the magnetic film / nonmagnetic film / magnetic film.

The magnetic recording / reproducing apparatus of the present invention can improve the recording density by about 2 to 10 times as compared with the conventional one, and particularly, the reproducing performance of the magnetoresistive effect element of the reproducing section is 1.
It can be improved about 5 to 20 times.

That is, the magnetoresistive effect generated by the difference in the direction of magnetization between the magnetic films separated from each other is utilized, and the thickness of the magnetic film is thinned by the separation, and the magnetic anisotropy according to the shape of the element is used. Is prevented and the sensitivity of the device to the magnetic field is prevented from being lowered. For the first time, miniaturization of the magnetoresistive effect element could be realized without lowering the reproducing ability. Further, the non-magnetic film is made sufficiently thin as compared with its electrical resistivity, and through this, electrons can be transmitted between the magnetic films, and a magnetoresistive effect depending on the spin direction is exhibited. In addition, the thickness and the structure are controlled so that the magnetic coupling between the magnetic films is zero or smaller than the magnetic field from the recording medium to enable a highly sensitive response of the device.

Secondly, the magnetization direction of the magnetic film separated by the non-magnetic film is induced in a specific direction. That is, the magnetic field from the recording medium is strongly guided parallel to the direction in which it reaches. More specifically, this is a direction parallel to the normal to the surface of the recording medium that the magnetoresistive effect element faces. With this, the magnetization of a part of the magnetic film of the magnetoresistive effect element is fixed in that direction, and the magnetization of the other magnetic film is rotated in response to the magnetic field from the recording medium. It was possible to generate it stably.

Thirdly, the magnetization of the other magnetic films is weakly induced in the direction perpendicular to the direction in which the magnetic field from the recording medium reaches. Here, the term “weakly induces” means that the strength of the magnetization of the part of the magnetic film is fixed,
It means that the strength of induction of magnetization of the magnetic film other than the above is weak.

This has the effect of promoting the rotation of the magnetization of the magnetic film, improving the sensitivity and suppressing the noise, especially at high frequencies. Furthermore, since the output when the magnetic field is zero is specified, there is an effect that the operation can be performed for both positive and negative magnetic fields.

The magnetic recording / reproducing apparatus of the present invention has a recording medium for magnetically storing a signal and a magnetoresistive effect element for detecting a magnetic field leaking from the medium, and outputs the magnetic field sensed by the element. It is preferable that the characteristics change stepwise.

Here, the step shape is a characteristic of the magnetoresistive effect reproducing head with respect to an external magnetic field, which is not a triangular shape but a characteristic similar to one quadrangular step, that is, the magnetic field changes relatively sharply. Parts and parts that show a nearly constant response to the magnetic field between them,
It is meant to exhibit the property of having.

The thickness of the magnetic film of the magnetoresistive effect element mounted in the present invention is 5 to 1000 Å, especially 10 to 10
It is preferably 0 °. This is because the magnetic film has sufficient magnetization at room temperature and the current can be effectively utilized for the magnetoresistive effect.

The thickness of the non-magnetic conductive film that isolates each magnetic film is preferably 5 to 1000 Å. The thickness of this non-magnetic conductive film does not hinder the conduction of electrons, and in particular, it is necessary to keep the antiferromagnetic or ferromagnetic coupling between the magnetic films sufficiently small. In the case of Cu, it is desirable to be about 10Å to 30Å.

As a material of the magnetic film, particularly the soft magnetic film, N
It is preferable to use an alloy having i of 70 to 95 atomic% and Fe of 5 to 30 atomic%.

Further, as the material of the magnetic film, the above Ni-
It is preferable to appropriately add Co to the Fe-based alloy in a range of 5 atomic% or less. Alternatively, Co30 to 85 atomic%, N
It is desirable to use an alloy thin film having a face-centered cubic structure of i2 to 30 atom% and Fe to 2 to 50 atom%. This is because these enable formation of a favorable laminated structure, have excellent soft magnetic characteristics, and produce a large magnetoresistive effect.

The material of the non-magnetic conductive film is Au,
It is preferable to use at least one of Ag and Cu.
This is because these films produce a magnetoresistive effect when combined with a magnetic film, have excellent electrical conductivity, and enable formation of a favorable laminated structure. An example of the configuration of the magnetoresistive effect element of the present invention is that NiO, NiFe, Cu, N is formed on a substrate.
A pair of electrodes is arranged on a film in which iFe, Cu, NiFe, and NiO are sequentially stacked. Or, NiO, C on the substrate
o / NiFe, Cu, Co / NiFe, Cu, Co / N
A pair of electrodes is arranged on a film in which iFe and NiO are sequentially laminated.

Alternatively, the magnetoresistive effect element of the present invention has a structure in which NiO, CoNiFe, Cu, NiFe, and C are formed on a substrate.
A pair of electrodes is arranged on a film in which u, Co / NiFe, and NiO are sequentially stacked. This is because these structures have the effect of effectively preventing the output from decreasing due to surface scattering, effectively increasing the output, and enabling the central film to be made thinner, which results from the shape anisotropy of the magnetic film. This is because it is possible to prevent the deterioration of the sensitivity of 1 without reducing the output.

In the magnetic recording / reproducing apparatus of the present invention, the magnetoresistive effect element is used as the reproducing portion in this way, and the high recording density, that is, the recording wavelength recorded on the recording medium can be shortened. Also, it is possible to realize recording with a narrow recording track width.
It is possible to obtain a sufficient reproduction output and maintain good recording.

The magnetoresistive effect element mounted in the magnetic recording / reproducing apparatus of the present invention has a first magnetic film which strongly induces magnetization in a direction perpendicular to the recording medium facing surface, and a weak magnetization in a direction perpendicular to the first magnetic film. The induced second magnetic films are adjacent to each other with a non-magnetic film interposed therebetween.

This element is arranged very close to the recording medium, and the magnetic field reaching the magnetoresistive element from the recording medium is sensed as a change in the electric resistance of the multilayer film. That is, the magnetization of the second magnetic film rotates in response to the magnetic field, and the magnetization of the first magnetic film hardly rotates. Therefore, the angle formed by the magnetizations of the first and second magnetic films changes stably with respect to the magnetic field, and a signal is output due to the magnetoresistive effect.

Electrons are transmitted between adjacent magnetic films via the non-magnetic film, and the probability of scattering changes depending on the spin direction of electrons due to the relative difference in the magnetization directions of the magnetic films. Therefore, a large magnetoresistive effect occurs. This effect does not depend on the direction of current in the film plane and the direction of overall magnetization.

The multilayer film of the magnetoresistive element is formed in a small area in a small area of 5 μm or less, and further in a width of 1 μm, so that the magnetic field from the recording medium can be sensed effectively and with high sensitivity, and particularly high recording is possible. The ability to reproduce at density is improved.

When the unidirectional anisotropic magnetic field by the bias film of the present invention is 100 to 200 Oersted, the anisotropic magnetic field Hk due to the shape is larger than the coercive force of the soft magnetic material and smaller than the bias magnetic field, 0.4 to 100. It is preferably less than Oersted. In the magnetoresistive element of the present invention, even if the thickness of the ferromagnetic layer is reduced to 10 to 50 Å, the output does not decrease. Therefore, the anisotropic magnetic field is 4 to 20 oersted even in the element having a width of 1 micron. It is small and does not deteriorate the sensitivity of the magnetoresistive element.

From the above points, the magnetic recording / reproducing apparatus of the present invention can improve the recording density by about 10 times as compared with the conventional type. More specifically, the recording wavelength is 0.1 to 0.1.
It is suitable as a magnetic recording / reproducing apparatus having a recording density of 3 μm and a track width of 0.2 to 4 μm, that is, an areal recording density of 1 to 30 Gb / in ² .

[0081]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1) FIG. 1 shows the structure of a magnetoresistive head of this embodiment. First, the SAL1, the separation film 2 and the MR film 3 were sequentially formed. 80 at% NiFe was used as the MR film 3. Then, a stencil-like photoresist was formed on the central active region. Then, the SAL1, the separation film 2 and the M in the region not masked by the resist material.
The R film 3 was removed by ion milling. At this time, the taper 5 diverging toward the end was formed by rotating the substrate while maintaining an appropriate angle with respect to the ion beam. Next, the permanent magnet film 7 and the electrode film 8 forming the end passive region were attached. Co _{0. 82} Cr ₀ as a permanent magnet film. ₀₉ Pt _{0. 09} film or _{Co 0. 80 Cr 0. 08} Pt 0. 09 (ZrO 2) 0. 03 film was used. The permanent magnet film this time was formed by the RF sputtering method, and a CoCrPt was prepared by placing a ZrO ₂ chip on the target.
The ZrO ₂ concentration in the film was adjusted. Bias magnetic field is Co ₀ thickness to provide the central active region of the permanent magnet film _{7. 82 Cr 0. 09 Pt} 0. 09
Film and _{Co 0. 80 Cr 0. 08} Pt 0. 09 (ZrO 2) 0. 03 film the same in respectively 50 nm, chosen 52 nm. The coercive force of each permanent magnet film was 600 Oe and 1200 Oe. The permanent magnet film and the electrode film attached on the stencil were removed together with the stencil by lift-off. SA
L1 applies a lateral bias magnetic field 4 to the MR film 3, and the permanent magnet film 7 applies a longitudinal bias magnetic field 6 to the MR film 3. After the MR film 3 is formed into a predetermined shape, the permanent magnet film 7 is laminated to be thinner than the total thickness of the SAL1, the separation film 2 and the MR film 3, and is removed so as not to remain on the MR film 3 portion. A taper is formed so as to remain at the ends of and. Further, the electrode film 8 is formed thereafter, and the MR film 3 is formed.
A taper is formed at the contact portion with. 9 is a lower gap film of alumina having a thickness of 0.4 μm, and 10 is Ni having a thickness of about 2 μm.
A lower shield film 11 made of an Fe alloy is for forming an alumina insulating film with a thickness of 10 μm on the surface of the substrate 12 and polishing it to smooth the surface of the substrate 12. A TiC-containing alumina sintered body is used for the substrate 12. The separation membrane 2 is a 200 Å Ta membrane. MR film 3 has a thickness of 4
A 00Å 80 at% Ni-Fe alloy is used.

As a result of measuring the electro-magnetic conversion characteristics of these heads, the output fluctuation was 20% and the waveform fluctuation was 10% C
o _{0. 82} Cr _0. to ₀₉ Pt _{0. 09} film heads using, Co _{0. 80
Cr 0. 08 Pt 0. 09} (ZrO 2) 0. 03 film within 5% power fluctuation in head using, could be reduced within 5% wave fluctuations. _{Therefore, Co 0. 80 Cr 0.} 08 Pt 0. 09 (ZrO 2) 0. 03 film was confirmed that BHN and waveform fluctuation suppressing effect is increased by the use of the permanent magnet film.

The central active region has an MR film, SAL1 which is a soft bias film for applying a lateral bias, and a separation film 2 which separates the two magnetic films. The edge passive region is composed of a permanent magnet film 7 which applies a longitudinal bias to the central active region. The edge junction region has two tapers in the central active region.

The permanent magnet film 7 applies a longitudinal bias to the central active region by the leakage magnetic field from the permanent magnet film and the coupling magnetic field at the junction region between the permanent magnet film and the central active region. The permanent magnet film needs to stably apply a magnetic field to the central active region against the magnetic field from the magnetic medium in order to suppress BHN.
For this purpose, the coercive force of the permanent magnet film must be 1000 Oe or more. As the permanent magnet film, a permanent magnet film such as CoPt or CoCrPt is used. A high coercive force can be obtained by using a base film of Cr or the like for the Co-based magnetic film.

FIG. 2 is a process chart showing a method of manufacturing a magnetic head having the structure of this embodiment. First SAL1, separation membrane 2
Then, the MR film 3 is sequentially formed (FIG. 2A). After that, a stencil-shaped photoresist 44 as shown in FIG. 2B is formed. Then, the SAL1, the separation film 2 and the MR film 3 in the region not masked by the resist material.
Are removed by ion milling (FIG. 2c). SA above
L1, the isolation film 2 and the masked region of the MR film 3 form a central active region 45. At this time, the substrate on which the three-layer film is attached is rotated while maintaining an appropriate angle with respect to the ion beam. The rotation of the substrate is centered on the substrate, and the angular velocity vector is perpendicular to the substrate surface. By performing ion milling in this manner, a taper 46 as shown in FIG. 2C is formed. Next, the end passive region 47 is formed. Permanent magnet film 48 and electrode film 49
(Fig. 2d). Of course, these films also deposit on the stencil and the taper. The permanent magnet film and the electrode film deposited on the stencil are removed together with the stencil by lift-off (Fig. 2e). Through the above process, the central active region and the end passive region contact with each other only at the junction M
An R head can be formed.

As the SAL1 composed of a soft magnetic film for applying a bias magnetic field to the magnetoresistive film, a soft magnetic film prepared by adding 10% of zirconium oxide to a magnetic alloy composed of 80 atomic% nickel and the balance iron was used by the sputtering method. Form 400 Å. Sputtering was performed using a target in which zirconium oxide chips were placed on a nickel-iron alloy target. The Ar gas pressure during sputtering was 2 mTorr. The substrate temperature was room temperature.
Further, an alumina film as an upper gap film of 0.3 μm is formed on the upper portion thereof, and an upper magnetic shield is formed on the upper portion thereof. Further, after forming an insulating film on the upper part thereof, an inductive magnetic head for recording is manufactured, but the details are omitted. After that, the substrate is cut and processed into a slider to complete the manufacture of the magnetoresistive effect magnetic head. Next, the characteristics of the magnetoresistive effect type magnetic head of this embodiment will be described. The magnetoresistive effect magnetic head was evaluated by reproducing output. For the magnetic head of this example, for comparison, a head having a similar structure and using a nickel-iron alloy in which 5% niobium was added to the bias film was used. The bias film to which zirconium oxide was added according to this example has a saturation magnetic flux density of 0.7 T and a specific resistance of about 120 μm.
In contrast, the nickel-iron film containing 5% niobium for comparison had a saturation magnetic flux density of 0.6 T and a specific resistance of 70 μΩcm. Nickel containing 5% niobium
The reproduction output of the magnetoresistive effect magnetic head using the iron film as the bias film was about 400 μV at the frequency of 10 MHz, whereas the magnetic head of the present invention is about 10% larger, about 44 μV.
It was 0 μV. This is a nickel-containing niobium-
This is because in the head using the iron alloy film as the bias film, the specific resistance of the bias film is small, so that the detected current flows in both the magnetoresistive effect film and the bias film, and the change in the read resistance becomes small. In the nickel-iron film to which niobium is added, it is possible to increase the electric resistance by increasing the amount of niobium to be added. Is the limit. As described above, in the magnetoresistive effect magnetic head of the present embodiment in which the nickel-iron film containing zirconium oxide is used as the bias film, the bias film has a large electric resistance, so that a high reproduction output can be obtained.

Next, the electric resistance of the bias film of the magnetoresistive head of the present invention will be described. FIG. 3 shows the specific resistance and saturation magnetic flux density of the film when zirconium oxide was added to the magnetic alloy film consisting of 80 atomic% nickel and the balance iron. The film thickness is 400Å. When aluminum oxide is added, the electrical resistance of the film increases to about 100% Ωcm at about 10%. On the other hand, the saturation magnetic flux density decreases monotonously with the addition of aluminum oxide, and at 10%, it is about 0.
It is 75T. This is an example of the case where aluminum oxide is added as a compound, but other compounds show the same tendency, and it is possible to form a film having a high specific resistance by adding the compound. Such a high resistivity film is
It is difficult to obtain by adding the conventional metal element, and it is understood that the addition of the compound is effective.

Next, the characteristics of the bias film containing various compounds will be described. Table 1 shows that a metal magnetic thin film consisting of 80% nickel and the balance iron is used for zirconium oxide, aluminum oxide, hafnium oxide, titanium oxide, beryllium oxide, magnesium oxide, cerium oxide as a rare earth oxygen compound, zirconium nitride, hafnium nitride, aluminum nitride, The values of coercive force, anisotropic magnetic field, and saturation magnetic flux density when titanium nitride, beryllium nitride, magnesium nitride, silicon nitride, and cerium nitride as a rare earth nitrogen compound are added at about 5% are shown.

[0089]

[Table 1]

For comparison, magnetic characteristics in the case of adding silicon oxide and in the case of adding metallic zirconium are also shown. The film was formed by the sputtering method. The target was a target in which chips of each compound were arranged on a nickel-iron alloy. The Ar gas pressure during sputtering was 2 mTorr and the film thickness was 400 Å. The specific resistance of each film was about 70 μΩcm. Further, the coercive force, anisotropic magnetic field, and saturation magnetic flux density all showed similar values with almost no dependence on the type of compound, but the anisotropy magnetic field of the film containing silicon oxide was as large as 15 Oe. There is. It is considered that this is because the binding energy of silicon oxide was small, the decomposition proceeded during film formation, and the generated oxygen was combined with iron or nickel to form an oxide inside.
The nitrogen compound added here has a smaller binding energy than the oxygen compound, but since the bond with the nitrogen of the magnetic elements iron, cobalt, and nickel is very weak, the magnetic element does not form a compound and the magnetic characteristics are deteriorated. Probably not.
This indicates that the magnetic characteristics are improved if the binding energy of the added compound is sufficiently larger than the binding energy of the compound of the same kind formed by the magnetic element. By analogy with the above, other compounds such as carbides, chlorides, and fluorides are expected to improve the magnetic properties,
Experiments were not conducted because carbides significantly contaminate the vacuum equipment, and chlorides and fluorides are mostly water soluble, which is expected to be problematic in terms of corrosion resistance of the film. For comparison, the film containing zirconium has a small coercive force and an anisotropic magnetic field, but the saturation magnetic flux density is significantly reduced to about 0.5T. This indicates that when zirconium is added as a metal, the electronic state of the magnetic element is significantly changed, and it is clear that addition as a compound is effective.

Next, the magnetic characteristics of the bias film obtained by adding zirconium oxide to various alloys will be described. Table 2 shows values of coercive force, anisotropic magnetic field, and saturation magnetic flux density when 5% of zirconium oxide is added to iron, iron-cobalt alloy, and nickel-cobalt alloy, which are metal magnetic materials.

[0092]

[Table 2]

For the iron-cobalt alloy, iron was 50 atomic% and the balance was cobalt. With regard to the nickel-cobalt alloy, nickel was 70 atomic% and the balance was cobalt. These films were formed by a sputtering method using a target in which a zirconium oxide chip was placed on a metal target. The Ar gas pressure during sputtering was 2 mTorr. Further, in order to impart magnetic anisotropy,
A magnetic field of about 40 Oe was applied during sputtering. The film thickness was 0.1 μm. For comparison, Table 2 also shows the magnetic characteristics when zirconium oxide is not added. In some cases, the term "anisotropic magnetic field" in the table is blank, but this is the case where no clear magnetic anisotropy was observed on the MH loop and the anisotropic magnetic field could not be measured. When the metal magnetic material is iron, the coercive force is as large as 8 Oe and no clear magnetic anisotropy is observed in the film to which zirconium oxide is not added. On the other hand, in the film to which zirconium oxide was added, the coercive force was reduced to about 3 Oe, magnetic anisotropy was observed, and the anisotropic magnetic field was 7 Oe. In the case of iron-cobalt alloys and nickel-cobalt alloys, the coercive force decreased when zirconium oxide was added, compared with the case where zirconium oxide was not added, and it is clear that the soft magnetic characteristics are improved. is there.

Example 2 Next, the material of the permanent magnet film in Example 1 was examined. The permanent magnet film is formed by the RF sputtering method, and ZrO ₂ or Ta ₂ O _{5 is} formed on the target.
The oxide concentration in the CoCrPt film was adjusted by arranging the chips. (Co ₀ at a thickness of 40nm in Figure 4. ₈₂ Cr _0.
The magnetic characteristics of ₀₉ Pt _{0 .09} ) _1-x Z _x films (Z = ZrO ₂ , Ta ₂ O ₅ ) are shown. It was found that the ZrO ₂ added film had a coercive force of 1200 Oe or more at an oxide concentration of 3 mol%. Even with Ta ₂ O ₅ , a coercive force of 1200 Oe or more was obtained. ZrO ₂ , Ta ₂ O
_The reason why the coercive force is reduced due to the large oxide concentration in the ₅ addition film is that the composition becomes amorphous due to the dispersion of the composition and the crystallinity in the plane of the permanent magnet film. In these systems, the coercive force was 1000 Oe or more when the oxide concentration was 0.5 mol% to 4 mol%. C of different composition
In the study using the oCrPt film, the preferable oxide concentration is 0.1.
It was 5 mol% to 10 mol%. Further, as oxides for increasing coercive force, Ti oxide, V oxide, Nb oxide, M
O oxides, Hf oxides, W oxides, Al oxides, Si oxides, Cr oxides are considered.

(Embodiment 3) FIG. 5 is a perspective view of a magnetoresistive head according to this embodiment.

The present embodiment has the same structure as that of the first embodiment, but the film laminated structure of the magnetoresistive head is different. A thickness of 50 n is sequentially formed on the lower gap film 9 made of alumina.
m as the antiferromagnetic film 13 made of NiO and the MR film 3 having a thickness of 1 nm of 80 at% Ni—Fe alloy film 14 and a thickness of 1 n.
m of Co film 15 and 2 nm thick Cu of non-magnetic metal film 1
6 and a SAL1 for applying a lateral bias formed of a soft magnetic film of NiFe alloy having a thickness of 5 nm.

The MR film 3 in this embodiment has a structure of two magnetic films (NiFe) sandwiching a thin non-magnetic film (Cu) and an antiferromagnetic film (NiO) in contact with one magnetic film. . This structure prevents instability in the manufacturing process and a decrease in sensitivity due to shunting of current. Further, as the antiferromagnetic film, oxide NiO that does not corrode in the manufacturing process is used as compared with the conventional material FeMn, and thereby high reliability is achieved in the mass production process. The output of the head is determined by the product of the current flowing through the head and the resistance change amount of the spin valve film, and the antiferromagnetic film itself does not contribute to the resistance change. Therefore, by using NiO, which is an insulating material, as the antiferromagnetic film, the input current is efficiently contributed to the resistance change,
It has become possible to obtain high magnetic field sensitivity. As described above, in this embodiment, the recording density of about 5 Gb / in ² can be realized.

Furthermore, a high reproduction output can be obtained by forming a film in which an oxide is dispersed in a NiFe alloy in the SAL1 in this embodiment as in the first embodiment.

(Embodiment 4) FIG. 6 is a sectional view of a magnetoresistive head according to this embodiment. S composed of a soft magnetic layer
The magnetic field is formed by sandwiching the AL1 and MR film 3 with the non-magnetic metal film 16. As the SAL1 and MR film 3 composed of magnetic layers, permalloy (Ni ₈₀ Fe ₂₀ ) having a thickness of 5 nm is used.
As the nonmagnetic metal film 16, Cu having a thickness of 2 nm is used. As the antiferromagnetic layer 13, NiO having a film thickness of 50 nm was used. The permanent magnet film 7 and the electrode film 8 which are hard magnetic layers are provided in contact with the magnetic film, and both are patterned at the same time. CoCrPt with a thickness of 10 nm is used as the hard magnetic layer, and Cu, Ag, Au, etc. are used as the electrodes.

The track width of 4 .mu.
m, the width of the magnetoresistive effect film in the depth direction is 2 μm, and the magnetoresistive effect element without a shield has an approximately linear change in resistance with respect to the applied magnetic field near the origin where the magnetic field is zero. Using this part, the medium magnetic field can be detected as a resistance change.

This element was sandwiched between the upper and lower shield films to produce a magnetoresistive effect reproducing head. At this time, amorphous Co—Ta—Zr (2 μm) was used for the lower shield, and permalloy (2 μm) was used for the upper shield. An alumina film formed by a sputtering method was used as the gap insulating film between the shields. In the magnetoresistive head manufactured in this way, Barkhausen noise was not recognized and good output characteristics were exhibited.

In the giant magnetoresistive head thus manufactured, the reproducing sensitivity distribution was measured by reproducing the recording track having a width of 0.8 μm while shifting the position in the track width direction. The reproducing head had a track width of 4 μm, a vertical shield spacing of 0.5 μm, and a magnetoresistive effect film having a width in the depth direction of 2 μm. The sensitivity distribution of the head of the present invention is shorter than that of the conventional giant magnetoresistive head. As described above, the magnetoresistive head of the present invention is advantageous in that the width of the hem of the sensitivity distribution is small and the reproduction crosstalk from the adjacent track can be reduced when recording is performed at a high track density. It was confirmed.

(Embodiment 5) FIG. 7 is a perspective view of a magnetoresistive head of this embodiment.

FIG. 8 is a conceptual diagram showing an example of anisotropy control of the magnetoresistive effect element of this embodiment. The bias films 31 and 32 made of an antiferromagnetic material apply anisotropy due to exchange coupling in the directions of arrows 71 and 72 in the figure. In the figure, an arrow 60 indicates the direction of a magnetic field to be sensed, and an arrow 61 indicates the direction of unidirectional anisotropy induced in the magnetic film 21. The easy magnetization direction of the magnetic film 22 sandwiched between the non-magnetic conductive films 20 is applied in the direction of arrow 62 in the figure by induction of uniaxial anisotropy. This is achieved by applying a magnetic field in a predetermined direction during the growth of the magnetic film. The embodiment of this figure is an example in which the application of anisotropy is realized by a bias film and induced magnetic anisotropy. As a result, both arrows 61 and 62 are orthogonal to each other in the film plane. By making the anisotropy of the magnetic film 21 larger and the anisotropy of the magnetic film 22 smaller than the magnitude of the magnetic field to be sensed, the magnetization of the magnetic film 21 is almost fixed to the external magnetic field, and Only the magnetization of the film 22 becomes highly responsive to the external magnetic field. Further, with respect to the magnetic field to be sensed in the direction of the arrow 60, the magnetization of the magnetic film 21 becomes an easy axis excitation state in which the magnetization and the external magnetic field are parallel to each other due to the anisotropy 61, and conversely to the anisotropy of the magnetic film 22. Therefore, the magnetization and the external magnetic field are in a state of hard axis excitation in which they are perpendicular to each other. Due to this effect, the above response can be made more prominent, and the magnetization of the magnetic film 22 against the external magnetic field is reduced by the arrow 6
Starting from the direction of 2, the state in which the element is driven by hard axis excitation due to rotation is realized, noise accompanying excitation due to domain wall movement can be prevented, and operation at high frequency can be enabled.

The film constituting the magnetoresistive effect element of the present invention was produced by the high frequency magnetron sputtering apparatus as follows. In an atmosphere of 3 mTorr of argon,
Ceramic substrate with thickness of 1 mm and diameter of 3 inches and S
The following materials were laminated in this order on an i single crystal substrate to manufacture.
As the sputtering target, nickel oxide, cobalt, nickel-20 at% iron alloy, and copper targets were used. To add cobalt into the nickel-iron, a cobalt tip was placed on a nickel-20 at% iron alloy target. To add nickel and iron to cobalt, nickel and iron chips were placed on the cobalt target. In the laminated film, high frequency power was applied to the cathodes on which the targets were arranged to generate plasma in the apparatus, and the shutters arranged for each cathode were opened and closed one by one to sequentially form each layer. At the time of film formation, a magnetic field of about 50 Oersted is applied in parallel to the substrate by using two pairs of electromagnets that are orthogonal to each other in the plane of the substrate to give uniaxial anisotropy and to change the direction of the exchange coupling bias of the nickel oxide film. Was guided in the direction of.

The anisotropic induction was performed by applying a magnetic field in the direction in which each magnetic film should be induced by two pairs of electromagnets mounted near the substrate. Alternatively, after forming the multilayer film, heat treatment in a magnetic field was performed near the Neel temperature of the antiferromagnetic film to induce the antiferromagnetic bias direction in the magnetic field direction.

The performance of the magnetoresistive effect element was evaluated by patterning the film into a strip shape and forming an electrode. At this time, the direction of uniaxial anisotropy of the magnetic film and the current direction of the element were set to be parallel. The electric resistance is measured by measuring the electric resistance of the element as the voltage between the electrode terminals by applying a constant current between the electrode terminals and applying a magnetic field in the plane of the element in the direction perpendicular to the current direction. did.

FIG. 9 is a diagram showing the rate of change in resistance with respect to a magnetic field of the element having the NiO film on the upper and lower sides, which is represented by sample No. 1 in Table 3. This is the bias film 3 in FIG.
NiO films for 1,32 and Ni ₈₀ Fe for magnetic films 21,22
_This corresponds to using a ₂₀ alloy thin film and a Cu film as the non-magnetic conductive film. However, before the magnetic field control is performed, the uniaxial anisotropy is not applied in the direction of arrow 62 in FIG. FIG.
The quadrangle-shaped curve of (4) well represents the characteristics of the magnetoresistive effect element of the present invention. That is, the effect of the magnetic film strongly induced in the direction of the magnetic field is detected as a loop in the left half of the curve. Another effect of the magnetic film, which is not strongly induced, appears as a sharp resistance change near the center. Since the reproduction output of the magnetoresistive effect element of the present invention corresponds to the magnitude of this resistance change rate and the sensitivity corresponds to the small saturation magnetic field, it is understood that the element output of the present invention is large and the sensitivity is high. . When there is antiferromagnetic coupling between the magnetic films, the curve in FIG. 9 has a triangular shape, and the magnetic field sensitivity of the element decreases.

As the non-magnetic conductive film, Cu, Ag,
Similar effects were obtained when Au was added and also in the sample in which the multilayer film was formed of Ag and Au.

FIG. 10 shows NiO / N in which the thickness of the Cu film is changed.
The magnetization curve was measured in the iFe / Cu / NiFe film,
It is the result of obtaining the strength of the magnetic coupling between the NiFe films.
The strength of magnetic coupling oscillates between antiferromagnetism / ferromagnetism with the thickness of Cu at about 10Å period. In order to obtain a magnetoresistive effect element having high sensitivity to a magnetic field, it is essential to make this magnetic coupling approximately zero. When Cu is used as the non-magnetic conductive film, as is clear from FIG.
By setting the thickness in the range of 11Å to 22Å, the magnetic coupling between the magnetic films can be made zero. As a result, it is possible to obtain a magnetoresistive element having a large change in electric resistance in response to a weak external magnetic field of several oersteds, that is, high sensitivity.

FIG. 11 is a diagram showing changes in the amount of addition and the resistance change rate when Co is added to the NiFe magnetic film. The structure of the element multilayer film is the same as in Table 3 and Sample No. 5. C
With the addition of o, the resistance change rate improved from about 4% of NiFe alone to 5.5%. This indicates that adding Co in addition to NiFe improves the magnetoresistive effect of the laminated film.

Table 3 shows a characteristic example of the magnetoresistive effect element manufactured by changing the structure of the film. The film structure is such that the left side of the paper is the base side and the right side is sequentially laminated.

[0113]

[Table 3]

In Table 3, the characteristics of the device are represented by the resistance change rate and the saturation magnetic field. The reproduction output as an element corresponds to the magnitude of this resistance change rate, and the sensitivity corresponds to the small saturation magnetic field. As is clear from the results in Table 3, the magnetoresistive elements (Nos. 1 to 5) of the present invention have a resistance change rate of 4% or more and good magnetic characteristics, and the conventional laminated film (No. 6, 7)
The resistance change rate is superior to In particular, sample N
o. 1, 2 and 4 show good magnetic field sensitivity of about 10 oersted of saturation magnetic field and high output of resistance change rate of 6 to 7%.

FIG. 12 shows NiO using Co as the magnetic film.
3 is a magnetoresistance curve of a / Co / Cu / Co film. Hysteresis due to the coercive force of the Co film was observed in the vicinity of the zero magnetic field, but the rate of change in resistance was 7%, which was almost double that in the case of using NiFe in the same configuration.

FIG. 13 shows NiO / Co ₅₁ Ni ₂₇ Fe ₂₂ / Cu /
The magnetic resistance curve of the NiFe / Cu / Co ₅₁ Ni ₂₇ Fe ₂₂ / NiO film has an output of 8% or more and a high magnetic field sensitivity near the zero magnetic field. In this way, NiFe or CoNiFe / NiNi with the NiO antiferromagnetic film as a base on the substrate is
The Cu laminated film has extremely high sensitivity as a magnetoresistive film.

(Embodiment 6) FIG. 14 is a block diagram of a magnetic recording / reproducing apparatus of the present invention. The recording medium 91 having the recording medium 95 on both sides is rotated by the spindle motor 93, and the head slider 90 is guided onto the track of the recording medium 95 by the actuator 92. However, recording medium 9
1 does not necessarily need to have a magnetic film on both sides of the disk. When the magnetic film is on only one side of the disk, the head slider 90 is arranged only on one side of the recording medium.

That is, in the magnetic disk device, the reproducing head and the recording head formed on the head slider 90 relatively move close to a predetermined recording position on the recording medium 95 by this mechanism to sequentially write and read signals. Of. The recording signal is recorded on the medium by the recording head through the signal processing system 94, and the output of the reproducing head is obtained as a signal through the signal processing system 94. Further, when the reproducing head is moved to a desired recording track, the position on the track can be detected by using the high-sensitivity output from the reproducing head, and the actuator can be controlled to position the head slider.

FIG. 15 is a conceptual diagram of a recording / reproducing separated type head in which a recording head is formed in addition to the above elements. The recording / reproducing separated type head comprises a reproducing head using the element of the present invention, an inductive recording head, and a shield part for preventing the reproducing head from being confused by a leakage magnetic field. Although mounting with a recording head for horizontal magnetic recording is shown here, the magnetoresistive effect element of the present invention may be combined with a head for perpendicular magnetic recording and used for perpendicular recording. The head has a reproducing head including a lower shield film 82, a magnetoresistive effect element 60, an electrode 40, and an upper shield film 81, and a recording head including a lower magnetic film 84, a coil 41, and an upper magnetic film 84 on a base body 50. I will do it. The head writes a signal on the recording medium and reads a signal from the recording medium. By forming the sensing portion of the reproducing head and the magnetic gap of the recording head at the overlapping position on the same slider in this way, they can be simultaneously positioned on the same track. This head was processed into a slider and mounted on a magnetic recording / reproducing device.

The magnetoresistive effect element 60 and the electrode 40 are formed on the base body 50 which also serves as the head slider 90, and this is positioned on the recording medium 91 to reproduce. The recording medium 91 rotates, and the head slider 90 relatively moves on the recording medium 91 so as to face each other at a height of 0.2 μm or less or in a contact state. By this mechanism, the magnetoresistive effect element 6
0 is set at a position where the magnetic signal recorded on the recording medium 91 can be read from the leakage magnetic field. The magnetoresistive effect element 60 is a film in which a plurality of magnetic films and non-magnetic conductive films are alternately laminated and a bias film, especially an antiferromagnetic film,
Consists of The feature of the present invention is that a part of the magnetic film of this laminated film,
Desirably, strong anisotropy is induced in every other layer of the laminated magnetic films in the direction of an arrow 61 perpendicular to the surface 63 facing the recording medium, and its magnetization is approximately fixed in this direction. It is in. The other film of the magnetic film is in the direction perpendicular to the arrow 61, that is, the arrow 6 in the film surface of the magnetoresistive film.
Anisotropy is applied relatively weakly in the direction 2 to induce the magnetization in this direction. With such a configuration, the signal magnetically recorded on the recording medium reaches the magnetoresistive effect element 60 as a leakage magnetic field 64 on the medium, and its component, in particular, the component in the film plane of the magnetoresistive effect film causes an arrow. The magnetization rotates from the direction of 62 as shown by an arrow 65, the angle formed by the directions of magnetization of two adjacent magnetic films via the non-magnetic conductive film changes, and the magnetoresistive effect occurs, thereby reproducing output. obtain. A portion of the magnetoresistive effect element that senses a signal is a portion through which a current of the magnetoresistive effect element 60 flows, that is, a portion sandwiched by the electrodes 40. The width 42 of the portion parallel to the surface of the recording medium 91 is recorded. The width is narrower than the width 44 of the track, and the ratio is particularly set to 0.8 or less to prevent the interference of the adjacent tracks due to the displacement of each other.

(Embodiment 7) FIG. 16 shows another embodiment of the structure of the thin film magnetic head in the magnetic recording / reproducing apparatus of the present invention. A recording head including lower and upper magnetic films 83, 84 and a coil 41 for applying a magnetomotive force to the lower and upper magnetic films, and a lower shield film 82 are formed on a substrate 50, and thereafter, a magnetoresistive effect element 60, an electrode 40, and an upper shield film. It forms between 81. In other words, a magnetoresistive film that is relatively sensitive to structure is formed on the recording head later to eliminate the stress and thermal effects that accompany the manufacturing of the recording head, and also facilitates alignment with the recording head, thereby facilitating magnetic recording / reproduction. The system is improved in the track width direction to improve productivity.

[0122]

According to the present invention, by forming the permanent magnet film on both ends of the magnetoresistive effect element, the electro-magnetic conversion characteristics are stabilized, and Barkhausen noise and wave fluctuation can be reduced. Further, according to the present invention, a reproducing output is large and a magnetic recording / reproducing apparatus having a high recording density can be achieved.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of a magnetoresistive effect magnetic head of the present invention.

FIG. 2 is a process drawing showing a manufacturing process of a magnetoresistive effect magnetic head of the present invention.

FIG. 3 is a diagram showing a relationship between a ZrO ₂ addition amount of a nickel-iron alloy, a saturation magnetic flux density, and a specific resistance.

FIG. 4 is a diagram showing a relationship between a coercive force of a permanent magnet film and an oxide.

FIG. 5 is a partial cross-sectional view of a magnetoresistive effect magnetic head of the present invention.

FIG. 6 is a partial cross-sectional view of a magnetoresistive effect magnetic head of the present invention.

FIG. 7 is a partial sectional view of a magnetoresistive effect magnetic head of the present invention.

FIG. 8 is a diagram illustrating magnetic anisotropy control of a magnetoresistive effect element multilayer film.

FIG. 9: NiO / NiFe / Cu / NiFe / Cu / N
FIG. 4 is a diagram showing the relationship between the magnetic field and the resistance change rate in the iFe / NiO film.

FIG. 10: Cu of NiO / NiFe / Cu / NiFe film
FIG. 4 is a diagram showing the thickness of layers and the strength of coupling between magnetic films.

FIG. 11 is a diagram showing a resistance change rate when Co is added to a NiFe film.

FIG. 12 is a diagram showing the relationship between the magnetic field and the resistivity of a NiO / Co / Cu / Co film.

FIG. 13: NiO / Co / NiFe / Cu / NiFe /
FIG. 6 is a diagram showing a relationship between a magnetic field and a resistivity in a Cu / Co / NiFe / NiO film.

FIG. 14 is a configuration diagram of a magnetic recording / reproducing apparatus according to the present invention.

FIG. 15 is a perspective view of a thin-film magnetic head having a reproducing magnetoresistive effect magnetic head and a recording induction magnetic head according to the present invention.

FIG. 16 is a perspective view of a thin film magnetic head having a reproducing magnetoresistive effect magnetic head and a recording induction magnetic head according to the present invention.

[Explanation of symbols]

1 ... SAL, 2 ... separation film, 3 ... MR film, 4 ... transverse bias magnetic field, 5 ... taper, 6 ... longitudinal bias magnetic field, 7 ... permanent magnet film, 8 ... electrode film, 9 ... lower gap film, 10 ... lower part Shield film, 11 ... Insulating film, 12 ... Substrate, 13 ... Antiferromagnetic layer, 16 ... Non-magnetic metal film, 60 ... Magnetoresistive effect element, 8
DESCRIPTION OF SYMBOLS 1 ... Upper shield film, 82 ... Lower shield film, 83 ... Upper magnetic film, 84 ... Lower magnetic film, 85 ... Coil conductor, 90
... head slider, 91 ... recording medium, 92 ... actuator, 93 ... spindle motor, 94 ... signal processing circuit system.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masahiro Komuro 1-280, Higashi Koikeku, Kokubunji, Tokyo Metropolitan Research Center, Hitachi, Ltd. (72) Hiroyuki Hoshiya 1-280, Higashi Koikeku, Kokubunji, Tokyo Hitachi Central Research Laboratory (72) Inventor Katsuro Watanabe 1-280, Higashi Koigokubo, Kokubunji City, Tokyo Metropolitan Hitachi Research Laboratory, Ltd. (72) Inventor Shigeru Tadokoro 2880 Kozu, Odawara, Kanagawa Hitachi Storage Systems Business Inside (72) Inventor Ryo Hiraga 4-6-chome, Surugadai Kanda, Chiyoda-ku, Tokyo Inside Hitachi, Ltd.

Claims (13)

[Claims] 1. A magnetoresistive effect film whose electric resistance changes according to a magnetic field, a lateral bias film for applying a lateral bias magnetic field to the magnetoresistive effect film, and a separation film provided between the magnetoresistive effect film and the lateral bias film. A pair of permanent magnet films for applying a longitudinal bias to the magnetoresistive effect film provided in contact with both ends of the magnetoresistive effect film, and signal detection in the magnetoresistive effect film. A magnetoresistive head having a pair of electrode films provided on the permanent magnet film for passing an electric current, wherein the thickness of the permanent magnet film is smaller than that of the magnetoresistive element film. 2. The permanent magnet film according to claim 1, wherein the permanent magnet film is Co.
-Pt alloy, Co-Cr-Pt alloy, or these alloys with Ti oxide, V oxide, Zr oxide, Nb oxide, Mo oxide, Hf oxide, Ta oxide, W oxide, Al oxidation. Stuff,
A magnetoresistive head comprising an alloy containing at least one element of Si oxide and Cr oxide. 3. The magnetoresistive head according to claim 1, wherein the permanent magnet film has a composition of (Equation 1) or (Equation 2). ## EQU1 ## Co _a Cr _b Pt _c or ... (Equation 1) (Equation 2) (Co _a Cr _b Pt _c ) _1-x (MO _y ) _x (Equation 2) (where x = 0.01 to 0.20, y: 0.4-3, a:
0.7-0.9, b: 0-0.15, C: 0.03-0.1
5, M: Ti, V, Zr, Mo, Hf, Ta, W, A
at least one of l, Si and Cr) 4. A magnetoresistive effect film whose electric resistance changes according to a magnetic field, a lateral bias film made of a soft magnetic film for applying a lateral bias magnetic field to the magnetoresistive effect film, and the lateral bias film and the magnetoresistive effect film. A separation film made of a non-magnetic film that magnetically separates, and a permanent magnet film for applying a longitudinal bias magnetic field to the magnetoresistance effect film, the lateral bias film, and the magnetoresistance effect film provided in contact with both ends of the separation film. And a pair of electrodes for supplying a current to the magnetoresistive film provided on the permanent magnet film, wherein the soft magnetic film for applying a transverse bias magnetic field to the magnetoresistive film is a nickel-iron alloy. , Cobalt, nickel-
One type of iron-cobalt alloy and zirconium oxide, aluminum oxide, hafnium oxide, titanium oxide, beryllium oxide, magnesium oxide, rare earth oxygen compound, zirconium nitride, hafnium nitride, aluminum nitride, titanium nitride, beryllium nitride, magnesium nitride, silicon nitride , And one or more compounds selected from rare earth nitrogen compounds. 5. The magnetoresistive head according to claim 4, wherein the soft magnetic thin film for applying a lateral bias magnetic field to the magnetoresistive film has a specific resistance of 70 μΩcm or more. 6. The magnetoresistive head according to claim 4, wherein the lateral bias film is made of a nickel-iron alloy having 78 to 84 atomic% of nickel. 7. A pair of permanent magnet films provided on a substrate,
A magnetoresistive effect magnetic head having a pair of electrodes formed on each of the permanent magnet films and a magnetoresistive effect element film provided in contact with the permanent magnets, wherein the element film is the substrate. Antiferromagnetic film made of nickel oxide from the side, 2
A magnetoresistive effect magnetic head characterized in that a ferromagnetic film, a nonmagnetic metal film, and a soft magnetic film are sequentially formed. 8. The two-layer ferromagnetic film according to claim 7, wherein the iron alloy layer containing 70 to 95 atomic% of Ni and the Co layer and the soft magnetic film are formed from the substrate side from the iron alloy layer or the substrate side. A magnetoresistive effect magnetic head comprising a Co layer and the iron alloy layer. 9. The magnetoresistive effect type structure according to claim 7, wherein the two-layered ferromagnetic film comprises a soft magnetic film from the antiferromagnetic side and a soft magnetic film having a larger magnetoresistance change rate than the soft magnetic film. Magnetic head. 10. A pair of permanent magnet films provided on a substrate, and a pair of electrodes formed on each of the permanent magnet films,
A magnetoresistive effect type magnetic head having a magnetoresistive effect element film provided in contact between the permanent magnets, wherein the element is an antiferromagnetic film, a ferromagnetic film, a nonmagnetic film from the substrate side,
A magnetoresistive effect magnetic head comprising a soft magnetic film, a non-magnetic film, a ferromagnetic film, and an antiferromagnetic film sequentially stacked. 11. The antiferromagnetic film is nickel oxide,
The ferromagnetic film on the substrate side is an iron alloy layer and a Co layer containing 70 to 95 atomic% of Ni, the soft magnetic film is the iron alloy layer, and the latter ferromagnetic film is a Co layer and the iron alloy layer from the substrate side. 11. The magnetoresistive effect type magnetic head according to claim 10. 12. The ferromagnetic film comprises an alloy containing 70 to 95 atomic% of Ni, 5 to 30 atomic% of Fe and 1 to 5 atomic% of Co,
11. The magnetoresistive head according to claim 10, which is an alloy of Co30 to 85 atomic%, Ni 2 to 30 atomic% and Fe 2 to 50 atomic%. 13. The non-magnetic conductive film is made of Au, Ag, Cu.
The magnetoresistive head according to claim 10, wherein the magnetoresistive head is any one of the following.