JPH06318515A - Magnetoresistive element and manufacture thereof and magnetic head and magnetic memory device - Google Patents

Abstract

PURPOSE:To provide a large magnetoresistive change ratio by inclining the boundary plane between an adjacent ferromagnetic layer and an adjacent non-ferromagnetic layer with respect to the film plane of a magnetoresistive effect film and allowing a current to flow through the magnetoresistive effect film so as to cross the boundary plane. CONSTITUTION:This magnetoresistive element is provided with a magnetoresistive effect film 1 formed on the surface of a base 2, and the magnetoresistive effect film 1 is formed by alternately laminating a ferromagnetic layer 11 made of a cobalt layer and a non-ferromagnetic layer 12 made of a copper layer. The boundary plane between the adjacent ferromagnetic layer 11 and the adjacent non-ferromagnetic layer 12 is inclined with respect to the top and bottom film surfaces of the magnetoresistive effect film 1 and exposed on the top and bottom film surfaces except both end parts of the film 1. A pair of electrodes are formed at both end parts, and a current flows through the inner part of the magnetoresistive effect film 1 so as to perpendicularly cross it. Thereby, a current can surely flow through the boundary plane between the ferromagnetic layer 11 and a non-ferromagnetic layer 12, so that a high magnetoresistive ratio change may be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetoresistive element having high sensitivity, a method of manufacturing the magnetoresistive element, a magnetic head and a magnetic recording apparatus using the magnetoresistive element.

[0002]

2. Description of the Related Art In a magnetic recording device such as a magnetic disk device, it is desired to improve the reading performance of information recorded on a magnetic recording medium.
Development of a magnetic head utilizing the magnetoresistive effect is in progress. Here, the "magnetoresistance effect" is a phenomenon in which the electric resistance value changes when a magnetic field is applied to a ferromagnetic material.

When the information recorded on the magnetic recording medium is read out by utilizing the magnetoresistive effect, the leakage magnetic field from the magnetic recording medium is guided to an element exhibiting the magnetoresistive effect, that is, a "magnetoresistive element". The direction of the magnetization of is changed and the change in the electric resistance value caused by it is detected.
Therefore, the greater the change in the electric resistance value with respect to the change in the magnetic field applied to the magnetoresistive element, the more the signal-to-noise ratio (S /
N) becomes large, and good characteristics are obtained.

As a magnetoresistive element, a permalloy thin film (single-layer film) has been generally used, but the "rate of change in magnetoresistance" is about 5% at most. “Magnetic resistance change rate” is the ratio (Δρ /) of the change in the electric resistance value of the element (Δρ) when a magnetic field is applied and when it is not applied to the electric resistance value (ρ) of the element when a magnetic field is not applied. ρ). Therefore, in recent years, attempts have been made to increase the rate of change in magnetic resistance. As one of them, a multilayer film formed by alternately stacking a cobalt (Co) layer (thickness: 15 angstrom) and a copper (Cu) layer (thickness: 9 angstrom) has a magnetic field of 48% at room temperature. The rate of resistance change is shown by Journal of Magnetics and Magnetic Materials, Vol. 94 (1991), pp. L1-L5 ("Jou
rnal of Magnetism and Magnetic Materials "Vol.94, 1
991, pp. L1-L5). In this multilayer film, 48% is utilized by utilizing the fact that the electric resistance value of the multilayer film varies greatly depending on whether the magnetization directions of the adjacent cobalt layers with the copper layer are antiparallel or parallel. That is a big change in magnetic resistance.

That is, in the multilayer film, the magnetization directions of the cobalt layers adjacent to both sides of the copper layer are antiparallel to each other in the state where no magnetic field is applied due to the interaction exerted through the copper layer. . When a sufficiently strong magnetic field is applied to the multilayer film in this state, the directions of magnetization of both cobalt layers coincide with the direction of the magnetic field, and the directions of magnetization of both cobalt layers become parallel to each other.

On the other hand, some conduction electrons have spins parallel to the magnetization direction and some have antiparallel spins. When a conduction electron enters the cobalt layer, it can move freely in the cobalt layer if it has a spin in the same direction as the magnetization of the cobalt layer, but a spin in the opposite direction to the magnetization of the cobalt layer. If it has, it is scattered near the interface between the copper layer and the cobalt layer.

Therefore, when the directions of magnetization of both cobalt layers are antiparallel (when no magnetic field is applied), electrons having spins in either direction have an interface of the cobalt layer having magnetization in the opposite direction to the spins. Since it is scattered by, the electric resistance value becomes large. On the other hand, when the magnetization directions of both cobalt layers are parallel (when a magnetic field is applied), electrons having spins opposite to those of the cobalt layers are scattered in the same manner as described above, Since all the conduction electrons having spins in the same direction as the magnetization can move in the cobalt layer without being scattered, the electric resistance value becomes small.

In the above-mentioned multilayer film, the change in the electric resistance value when a magnetic field is applied and when it is not applied is extremely large.
As described above, a large magnetoresistance change rate of 48% can be obtained.

[0009]

In the above Co / Cu multilayer film, the direction of magnetization of the cobalt layer is changed from antiparallel to parallel, in other words, the magnetic field required to obtain the maximum change in electric resistance is It is about 4000 Oersted (Oe), which is very large. In a general magnetic recording device, it is necessary to read information with a magnetic field of about 100 Oersted, so that the Co / Cu multilayer film cannot be used in a magnetic recording device.

Further, in the Co / Cu multilayer film, the magnitude of the magnetic field required to obtain the maximum change in electric resistance value changes according to the thickness of the constituent layers. For example, increasing the thickness of the copper layer from 9 angstroms to 14 angstroms can reduce the required magnetic field. However, on the other hand, the rate of change in magnetoresistance (Δρ /
There is a problem that ρ) decreases.

Therefore, an object of the present invention is to provide a magnetoresistive element having a larger magnetoresistive change rate and a manufacturing method thereof.

Another object of the present invention is to provide a magnetoresistive element and a method for manufacturing the same, which can obtain a larger magnetoresistive change rate by applying a magnetic field of about 100 Oersted.

Still another object of the present invention is to provide a magnetic head and a magnetic recording device which can obtain a reproduction output higher than conventional ones.

[0014]

[Means for Solving the Problems]

(1) In the first aspect, the magnetoresistive element according to the first aspect is a magnetoresistive element including a magnetoresistive effect film formed by alternately stacking ferromagnetic layers and non-ferromagnetic layers. An interface between the layer and the non-ferromagnetic layer is inclined with respect to a film surface of the magnetoresistive effect film, and a current flows in the magnetoresistive effect film across the interface.

According to a second aspect of the magnetoresistive element of the present invention, in the magnetoresistive element including a magnetoresistive effect film in which ferromagnetic layers and non-ferromagnetic layers are alternately laminated, adjacent ferromagnetic layers are provided. An interface between the layer and the non-ferromagnetic layer is exposed on at least one film surface of the magnetoresistive film, and a current flows in the magnetoresistive film across the interface. .

In the magnetoresistive element according to the first and second aspects of the present invention, the angle formed by the interface and the film surface is 1 to 3.
It is preferably in the range of 0 °. This is because if it is less than 1 °, the improvement rate of the magnetic resistance is not sufficiently improved, and if it is more than 30 °, it becomes difficult to form a film.

The angle formed by the interface and the film surface is more preferably in the range of 5 to 10 °. This is because if it is less than 5 °, variations in characteristics are large due to an error in angle formation, and if it is more than 10 °, the yield of film formation decreases.

The magnetoresistive effect film is preferably fixed to a substrate. An alumina film, for example, is used as the substrate. In this case, there is an advantage that the magnetoresistive effect film can be used more easily than in the case where the substrate is not provided.

The electric current preferably flows perpendicular to a straight line formed by the interface intersecting the film surface. This is because the magnetoresistance change rate is most improved in this case.

The magnetic field is preferably applied to the magnetoresistive film such that the interface is 30 ° or less with respect to a straight line formed by intersecting the film surface. This is because if it is larger than 30 °, the magnetic field required for operation, that is, the magnetic field required to obtain the maximum magnetoresistance change rate becomes too large.

Most preferably, the magnetic field is applied parallel to the straight line (the angle between the magnetic field and the straight line is 0 °). In this case, a high magnetoresistance change rate is obtained in the lowest magnetic field.

It is preferable that film surfaces inclined with respect to the interface are formed on both sides of the magnetoresistive film, and the interface is exposed on both film surfaces. In this case, there is an advantage that the current surely flows through the interface.

Ferromagnetic layer constituting the magnetoresistive film /
As a combination of non-ferromagnetic layers, for example, Co layer / Cu
Layer, Ni-Fe layer / Cu layer, Fe layer / Cu layer, Co layer /
Examples thereof include Ag layer, Fe layer / Ru layer, and the like.

The thickness of the ferromagnetic layer is preferably 10-
The thickness of the non-ferromagnetic layer is 30 angstroms, and preferably 5 to 200 angstroms. Thickness is 10
It is difficult to form a ferromagnetic layer smaller than angstrom or a non-ferromagnetic layer whose thickness is smaller than 5 angstrom. A ferromagnetic layer having a thickness greater than 30 angstroms or a non-ferromagnetic layer having a thickness greater than 200 angstroms cannot provide a sufficiently large magnetoresistance change rate.

The repeating period of the ferromagnetic layer and the non-ferromagnetic layer forming the magnetoresistive film is preferably 10 to 100 cycles, more preferably 20 to 60 cycles. If it is less than 10 cycles, the magnetoresistance change rate is small, and if it is more than 100 cycles, it becomes difficult to obtain a clear laminated structure over the entire film. Further, in the range of 20 to 60 cycles, a sufficiently large magnetoresistance change rate can be obtained with good reproducibility.

(2) In the method of manufacturing a magnetoresistive element according to the present invention, a magnetoresistive effect film having a multilayer structure in which ferromagnetic layers and non-ferromagnetic layers are alternately laminated on each other and the layers are substantially parallel to each other is provided. The step of forming and removing at least one of the front surface and the back surface of the magnetoresistive film obliquely with respect to the interface between the ferromagnetic layer and the non-ferromagnetic layer, thereby forming a film surface inclined with respect to the interface. And a step of forming a pair of electrodes on the magnetoresistive film so that a current flows in the magnetoresistive film across the interface.

In this method, the step of obtaining a film surface inclined with respect to the interface includes the step of forming a mask on at least one of the front surface and the back surface of the magnetoresistive effect film, and the magnetoresistive effect using the mask. And a step of performing ion milling of the film. In this case, a film surface inclined with respect to the interface can be easily obtained.

Further, it is preferable to include a step of forming a film to be a base on the film surface, subsequent to the step of obtaining the film surface inclined with respect to the interface. The method for performing the step of forming the film to be the base is not particularly limited, and any method can be used. In this case, there is an advantage that the magnetoresistive film can be easily used.

It is preferable to include a step of forming film surfaces inclined with respect to the interface on both sides of the magnetoresistive effect film.
In this case, there is an advantage that the current surely flows through the interface.

It is preferable to include a step of forming a pair of electrodes so that a current flows in the magnetoresistive film perpendicularly to the interface. The method of performing this step is not particularly limited, and any method can be used.

(3) The magnetic head of the present invention is characterized by comprising the magnetoresistive element of (1) for reproducing information.

(4) The magnetic recording apparatus of the present invention is characterized by including the magnetic head of (3) for reproducing information.

[0033]

[Function] In a magnetoresistive film having a multi-layer structure in which ferromagnetic layers and non-ferromagnetic layers are alternately laminated, the motion component perpendicular to the interface between the ferromagnetic layer and the non-ferromagnetic layer possessed by conduction electrons is It significantly contributes to the change in magnetic resistance.

In the conventional multi-layered magnetoresistive film, almost all the conduction electrons move parallel to the film surface, that is, parallel to the interface between the adjacent ferromagnetic layer and non-ferromagnetic layer.
The component of the motion of the conduction electrons perpendicular to the interface is very small.

On the other hand, in the magnetoresistive element of the present invention, the interface between the adjacent ferromagnetic layer and non-ferromagnetic layer is inclined with respect to the film surface of the magnetoresistive film, and the current intersects with the interface. In other words, since it flows through the interface and flows inside the magnetoresistive film, the component of motion perpendicular to the interface is extremely large. Therefore, a remarkably large magnetoresistance change rate can be obtained as compared with the conventional magnetoresistive film.

In the magnetoresistive element of the present invention, the magnetic field required to make the magnetization directions of the two ferromagnetic layers adjacent to each other through the non-ferromagnetic layer parallel to each other is about 100 oersted. Even if the thickness of the ferromagnetic layer is selected, a sufficiently large magnetoresistance change rate can be obtained for a magnetic recording device.

According to the method of manufacturing a magnetoresistive element of the present invention, the magnetoresistive element can be easily obtained.

Since the magnetic head and the magnetic recording apparatus of the present invention are provided with a magnetoresistive element having a higher magnetoresistive change rate for reproducing information, a reproduction output larger than that of the related art can be obtained.

[0039]

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[First Embodiment] FIGS. 1 to 3 show a first embodiment of the magnetoresistive element of the present invention. This magnetoresistive element includes a base 2 made of alumina (Al ₂ O ₃ ) and a magnetoresistive effect film 1 formed on the surface of the base 2. The magnetoresistive film 1 is formed by alternately stacking a ferromagnetic layer 11 made of a cobalt (Co) layer having a thickness of 15 angstroms and a non-ferromagnetic layer 12 made of a copper (Cu) layer having a thickness of 9 angstroms. It is configured and is a so-called multilayer film. The stacking period of the ferromagnetic layer 11 and the non-ferromagnetic layer 12 is 30 periods. The film surface of the magnetoresistive effect film 1, that is, the front surface (upper surface) and the back surface (lower surface) are parallel to each other, and therefore the thickness of the film 1 is constant.

The interface between the adjacent ferromagnetic layer 11 and non-ferromagnetic layer 12 is inclined by θ ° with respect to the upper and lower film surfaces of the magnetoresistive film 1, and both ends of the film 1 (in FIG. 1). Exposed on the upper and lower film surfaces except the left and right end portions). Since the upper and lower film surfaces of the film 1 are parallel to the surface of the substrate 2, the interface between the ferromagnetic layer 11 and the non-ferromagnetic layer 12 is also inclined by θ ° with respect to the surface of the substrate 2. On the upper and lower membrane surfaces of the membrane 1,
A plurality of straight lines formed by intersecting the interfaces of the ferromagnetic layer 11 and the non-ferromagnetic layer 12 appear on the film surfaces. In FIG. 1, these straight lines extend in the direction perpendicular to the paper surface.

A pair of electrodes (see FIG. 3 (f)) are formed on both ends (left and right ends in FIG. 1) of the magnetoresistive film 1, and as shown in FIG. A current flows in a direction orthogonal to the straight line (from the left end to the right end in FIG. 1). Therefore, the current, that is, the conduction electrons can surely move through the interface between the ferromagnetic layer 11 and the non-ferromagnetic layer 12, and as a result, a higher magnetoresistive change rate than that of the conventional case can be obtained.

Further, in this embodiment, the current makes the maximum angle with respect to the straight line formed by the interface between the ferromagnetic layer 11 and the non-ferromagnetic layer 12 intersecting the film surface, and therefore the maximum magnetic field is obtained. The rate of resistance change is obtained.

As shown in FIG. 1, the magnetic field (magnetic flux) applied to the magnetoresistive film 1 is parallel to the straight line formed by intersecting the interface with the film surface. In other words, this magnetic field is applied orthogonally to the current. Here, the magnetic field is from the front of the paper to the other side. For this reason,
The magnetization directions of the respective ferromagnetic layers 11 are easily aligned with the magnetic field direction, and therefore the magnetic field required for operation can be minimized.

In the magnetoresistive element of the present invention having the above-mentioned structure, a larger magnetoresistive change rate than the conventional one can be obtained for the following reason.

In the magnetoresistive film 1 of the present invention, in a state where no magnetic field is applied, as shown in FIG. 2A, the ferromagnetic (Co) layer 1 adjacent to both sides of the non-ferromagnetic (Cu) layer 12 is formed.
The magnetization directions of 1 are antiparallel to each other due to the interaction exerted through the non-ferromagnetic layer 12. When a sufficiently strong magnetic field H is applied to the film 1 parallel to the film surface, each ferromagnetic layer 11
The magnetization directions of are aligned with the direction of the magnetic field H and are parallel to each other.

When conduction electrons enter the magnetoresistive film 1, if they have spins in the same direction as the magnetization of the ferromagnetic layer 11, they can move freely through the ferromagnetic layer 11. When the spin has a direction opposite to the magnetization of the ferromagnetic layer 11, it is scattered near the interface between the layers 11 and 12 as shown in FIG. Therefore, when the magnetization directions of the ferromagnetic layer 11 are antiparallel (when the magnetic field H is not applied),
Electrons having spins in either direction are scattered at the interface of the ferromagnetic layer 11 having a magnetization in the direction opposite to the spins, so that the film 1
It is difficult to move through, resulting in a higher electrical resistance value than would be the case if current were passed parallel to those interfaces.

On the other hand, when the magnetization directions of the ferromagnetic layer 11 are parallel (when the magnetic field H is applied), FIG.
As shown in, the conduction electrons with spins opposite to the magnetization are scattered at the interface, but all the conduction electrons with spins in the same direction as the magnetization move in the ferromagnetic layer 11 without being scattered. Therefore, the electric resistance value becomes smaller than that in the case where an electric current is passed parallel to the interface.

Moreover, in the magnetoresistive effect film 1 of the present invention, as shown in FIG. 2B, the conduction electrons surely penetrate through the interface when moving inside the film 1, so that almost all conduction is performed. The electrons contribute to the magnetoresistive effect.

Therefore, a much larger magnetoresistance change rate (Δρ / ρ) than that of the conventional magnetoresistance effect film can be obtained.

The magnetoresistive element having the above structure is manufactured as follows.

First, a cobalt (Co) layer having a thickness of 15 angstroms and a copper (Cu) layer having a thickness of 9 angstroms are alternately formed on the surface (upper surface) of the silicon substrate 3 for film formation by the sputtering method. Stack for 30 cycles. As a result, the magnetoresistive effect film 1 having a multilayer structure as shown in FIG. 3A is obtained on the substrate 3.

Next, a noblack photoresist film is formed on the surface of the magnetoresistive film 1, and the resist film is heat-softened so that a taper is attached as shown in FIG. 3 (b). The mask 4 is formed. The thickness of the mask 4 gradually decreases from the right end to the left end of the film 1.

Subsequently, the magnetoresistive effect film 1 is ion-milled by irradiating argon ions Ar ⁺ from above the tapered mask 4. As a result, as shown in FIG. 3C, the left end side of the film 1 is removed more than the right end side. The total length of the remaining film 1 is 10 μm, and its thickness decreases from the right end to the left end, reflecting the shape of the mask 4.

On the surface of the thus-tapered magnetoresistive effect film 1, a thickness of 0.
A 1 mm alumina (Al ₂ O ₃ ) film is deposited. Base 2
Is formed on the inclined surface of the film 1 (which newly becomes the first film surface) with a substantially uniform thickness, as shown in FIG.

Next, on the back surface (lower surface) of the silicon substrate 3,
After a noblack photoresist film (not shown) is formed, the resist film is heat-softened to form a film shown in FIG.
A mask with a taper (not shown) similar to that in (b) is formed. Contrary to FIG. 3B, the cross-sectional shape of this mask is a taper whose thickness decreases from the left end to the right end. Both masks have the same taper degree.

Subsequently, argon ions Ar ⁺ are irradiated from under the mask formed on the back surface of the substrate 3 to ion mill the substrate 3 and the magnetoresistive effect film 1. As a result, the substrate 1 is completely removed, and the film 1 is removed in a tapered shape reflecting the mask shape. Film 1 formed by this
The inclined surface of is a second film surface. Thus
As shown in FIG. 3E, the magnetoresistive effect film 1 having the first film surface and the second film surface parallel to each other and having a uniform thickness is obtained in a state of being fixed to the substrate 2. In this state, the interface between the cobalt layer and the copper layer inclined with respect to both film surfaces is exposed on both film surfaces.

Then, as shown in FIG. 3 (f), gold (A
A pair of electrodes 5 made of a metal film such as u) is formed on both ends of the magnetoresistive film 1. In this way, the magnetoresistive element shown in FIG. 1 is obtained.

By the above manufacturing method, the magnetoresistive effect film 1 was manufactured in which the angle θ formed by the interface between the cobalt layer and the copper layer and the film surface was changed, and the magnetoresistive change rate (Δρ / ρ) thereof was measured. . The magnetic field and current were applied as shown in FIG. The result is shown in FIG.

From FIG. 4, when the interface corresponding to the conventional example and the film surface are parallel (θ = 0 °), the magnetoresistance change rate (Δρ / ρ) is 32%. In the resistance effect film 1, when θ = 20 °, (Δρ / ρ) = 62%, θ =
At 40 °, (Δρ / ρ) = 74%, and it can be seen that the magnetoresistance change rate is significantly improved.

Further, the magnetic field required for the operation (the magnetic field that gives the maximum magnetoresistance change rate) Hs was measured by changing the direction in which the magnetic field is applied in a plane parallel to the film surface of the magnetoresistive effect film 1. The direction of the magnetic field is shown by an angle φ with respect to a straight line formed by the interface between the cobalt layer and the copper layer intersecting the film surface as shown in FIG. Note that θ = 20 °.

From FIG. 5, Hs is minimized when applied in parallel with the straight line (φ = 0 °), and when φ is increased,
It can be seen that Hs monotonically increases accordingly. This is because the easy magnetization direction is in the plane parallel to the interface.
It is conceivable that the component of the magnetic field in the interface direction becomes smaller as R becomes larger, and as a result, it becomes gradually difficult to rotate the magnetization. Further, from this result, in order to reduce Hs, it is most preferable to apply the magnetic field in φ = 0, that is, in the direction parallel to the straight line formed by the interface between the cobalt layer and the copper layer intersecting the film surface. I understand.

Further, a magnetoresistive effect film 1 having the same structure as described above was manufactured except that the thickness of the non-ferromagnetic Cu layer was 12 Å, and the angle θ and the magnetoresistive change rate (Δρ / ρ) were produced. The relationship with was measured. The result is shown in FIG.

As shown in FIG. 6, by increasing the thickness of the Cu layer to 12 angstroms, the magnetoresistance change rate (Δρ / ρ) is smaller than that in the case of 9 angstroms. (Δρ / ρ) is about 5% at θ = 0 °,
It can be seen that the value increases with the increase of θ and about 10% is obtained at θ = 30 °.

Further, by increasing the thickness of the Cu layer to 12 angstroms, the magnetic field Hs required for operation is significantly reduced. This graph is not shown,
When θ = 30 °, Hs is about 70 Oersted,
A value sufficient for using this magnetoresistive element in a magnetic recording device was obtained.

Therefore, if a magnetic recording device is constructed using this magnetoresistive element, the read performance of information recorded on the magnetic recording medium can be dramatically improved.

In this embodiment, the multilayer film in which the cobalt layers and the copper layers are alternately laminated is described. However, if the multilayer film in which the ferromagnetic layers and the non-ferromagnetic layers are alternately laminated is used, other materials may be used. Needless to say, a multilayer film may be used.

[Second Embodiment] FIG. 7 shows an embodiment of the magnetic head of the present invention. This magnetic head has Hs = 70 Oersted and (Δρ / ρ) = 1 as shown in the first embodiment.
It uses a 0% magnetoresistive element.

A pair of electrodes 5 are attached to both ends of the magnetoresistive film (thickness 1200 Å) 1 described in the first embodiment, and further, alumina (Al ₂
Insulating layer consisting of O ₃ (thickness 20 Å) 7
A permanent magnet layer (thickness: 500 angstrom) 6 made of Co-20 at% Pt is formed so as to be opposed to each other with the film sandwiched therebetween. The permanent magnet layer 6 is for applying a bias magnetic field of 35 Oersted to the magnetoresistive effect film 1. These are arranged in a region sandwiched by two shield layers (thickness 1 μm) 8 made of a Ni—Fe alloy. Although not shown, an insulating layer made of silicon dioxide (SiO ₂ ) is arranged between the magnetoresistive film 1 and the electrode 5 and the shield layer 8.

Since the magnetic head of the present invention uses the magnetoresistive element having a higher magnetoresistive change rate than the conventional one,
A reproduction output higher than the conventional one (for example, 4 times that of the conventional example) can be obtained.

Although the bias method using the permanent magnet layer is shown here, other bias methods such as the shunt bias method, the soft bias method, and the mutual bias method which are known in the general magnetoresistive head are used. Good. Also, a configuration different from the configuration of FIG. 7 may be used.

[Third Embodiment] FIG. 8 shows a magnetic disk drive equipped with the magnetic head of the second embodiment for reproducing information.

In this magnetic disk device, a plurality of magnetic recording media 21 fixed to a spindle, a magnetic recording medium drive unit 22 for rotationally driving the magnetic recording media 21, and information is recorded on the magnetic recording medium 21. A magnetic head 23 for reproducing information recorded on the magnetic recording medium 21, a magnetic head drive unit 24 for driving and controlling the magnetic head 23,
A recording / reproducing signal processing system 2 for performing a predetermined processing of a recording signal and a reproducing signal between the magnetic head 23 and an external device (not shown).
And 5 are provided. The magnetic head 23 incorporates the magnetic head of the second embodiment for reproducing information and the induction type magnetic head for recording information.

After the information was recorded on the magnetic recording medium 21 by the inductive head for information recording, and the information was reproduced by the above magnetic head for information reproduction, a reproduction output higher than the conventional one (for example, in the conventional example) was obtained. 3 times) was obtained.

A magnetic recording device having a structure different from that of the magnetic disk device may be used.

[0076]

According to the magnetoresistive element of the present invention, a larger magnetoresistance change rate than the conventional one can be obtained, and the large magnetoresistance change rate can be obtained by applying a magnetic field of about 100 Oersted.

In the method of manufacturing the magnetoresistive element of the present invention,
A magnetoresistive element having a high magnetoresistive change rate as described above can be easily obtained.

With the magnetic head and the magnetic recording apparatus of the present invention, a reproduction output larger than that of the conventional one can be obtained.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part of a magnetoresistive element according to a first embodiment of the present invention.

FIG. 2 is a conceptual diagram for explaining a mechanism in which a magnetoresistive effect appears in the magnetoresistive element of the first embodiment.

FIG. 3 is a cross-sectional view of a main part showing the method of manufacturing the magnetoresistive element of the first embodiment in the order of steps.

FIG. 4 is a graph showing a magnetoresistive change rate characteristic of the magnetoresistive element of the first example.

FIG. 5 is a graph showing characteristics of a magnetic field required for the operation of the magnetoresistive element of the first example.

FIG. 6 is a graph showing a magnetoresistive change rate characteristic of the magnetoresistive element of the first example.

FIG. 7 is a perspective view schematically showing a configuration of a magnetic head according to a second embodiment of the present invention.

FIG. 8 is a plan view and a sectional view schematically showing the configuration of a magnetic disk device according to a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Magnetoresistive effect film 2 Substrate 3 Film forming substrate 4 Photoresist mask 5 Electrode 6 Permanent magnet layer 7 Insulating layer 8 Shield layer 11 Ferromagnetic layer (Co) 12 Non-ferromagnetic layer (Cu) 21 Magnetic recording medium 22 Magnetic Recording medium drive unit 23 Magnetic head 24 Magnetic head drive unit 25 Recording / reproducing signal processing system

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Yoshiyuki Hirayama 1-280 Higashi Koikeku, Kokubunji City, Tokyo Inside Central Research Laboratory, Hitachi, Ltd. (72) Masaaki Ninomoto 1-280 Higashi Koikeku, Tokyo Kokubunji City Hitachi Ltd. Central Research Laboratory

Claims (15)

[Claims] 1. A magnetoresistive element comprising a magnetoresistive effect film comprising a ferromagnetic layer and a non-ferromagnetic layer alternately stacked, wherein an interface between the ferromagnetic layer and the non-ferromagnetic layer adjacent to each other is the magnetic layer. A magnetoresistive element, which is inclined with respect to a film surface of a resistance effect film, and a current flows in the magnetoresistive effect film across the interface. 2. A magnetoresistive element comprising a magnetoresistive effect film comprising a ferromagnetic layer and a non-ferromagnetic layer alternately stacked, wherein an interface between the ferromagnetic layer and the non-ferromagnetic layer adjacent to each other is the magnetic layer. It is exposed on at least one film surface of the resistance effect film,
A magnetoresistive element characterized in that a current flows in the magnetoresistive film across the interface. 3. The angle formed by the interface and the film surface is 1 to
The magnetoresistive element according to claim 1 or 2, which is in the range of 30 °. 4. The magnetoresistive element according to claim 1, wherein the magnetoresistive effect film is fixed to a substrate. 5. The magnetoresistive element according to claim 1, wherein a current flows perpendicularly to a straight line formed by the interface intersecting the film surface. 6. A magnetic field is applied to the magnetoresistive film such that the interface is 30 ° or less with respect to a straight line formed by intersecting the interface with the film surface. The magnetoresistive element described. 7. The magnetoresistive element according to claim 6, wherein a magnetic field is applied to the magnetoresistive film parallel to a straight line formed by the interface intersecting the film surface. 8. The magnetoresistive element according to claim 1, wherein the interface is exposed on film surfaces on both sides of the magnetoresistive film. 9. A step of alternately stacking a ferromagnetic layer and a non-ferromagnetic layer on a substrate to form a magnetoresistive film having a multilayer structure in which the respective layers are substantially parallel to each other, and the surface of the magnetoresistive film. And at least one of the back surface is obliquely removed with respect to the interface between the ferromagnetic layer and the non-ferromagnetic layer, thereby obtaining a film surface inclined with respect to the interface, and a current in the magnetoresistive film. And a step of forming a pair of electrodes on the magnetoresistive effect film so as to flow across the interface. 10. The step of obtaining a film surface inclined with respect to the interface includes the step of forming a mask on at least one of the front surface and the back surface of the magnetoresistive effect film, and the step of forming the magnetoresistive effect film using the mask. The method of manufacturing a magnetoresistive element according to claim 9, which further comprises a step of performing ion milling. 11. The method of manufacturing a magnetoresistive element according to claim 9, further comprising a step of forming a film to be a base on the film surface, subsequent to the step of obtaining the film surface inclined with respect to the interface. . 12. The method according to claim 9, further comprising forming film surfaces inclined with respect to the interface on both sides of the magnetoresistive film.
12. The method for manufacturing a magnetoresistive element according to any one of 11. 13. The method of manufacturing a magnetoresistive element according to claim 9, further comprising the step of forming a pair of electrodes so that a current flows in the magnetoresistive film perpendicularly to the interface. 14. A magnetic head comprising the magnetoresistive element according to claim 1 for reproducing information. 15. A magnetic recording device comprising the magnetic head according to claim 14 for reproducing information.