JP3524341B2 - Magnetoresistive element, and magnetic head, magnetic recording / reproducing head and magnetic storage device using the same - Google Patents

Description

Detailed Description of the Invention

[0001]

The present invention relates to a magnetoresistive effect element having a magnetic multilayer film exhibiting a giant magnetoresistive effect, a magnetic head using the same, a magnetic recording / reproducing head and a magnetic storage device.

[0002]

2. Description of the Related Art In a magnetic recording device such as an HDD, the recording track width is being reduced in order to improve the recording density. A magnetic head (MR head) to which a highly sensitive magnetoresistive effect element (MR element) is applied is becoming necessary in order to compensate for the reduction in reproduction output due to the reduction of the recording track width. In particular, a ferromagnetic film whose magnetization rotates according to a signal magnetic field (hereinafter referred to as a magnetization free layer), a non-magnetic film, or a ferromagnetic film whose magnetization is fixed by a bias magnetic field from an antiferromagnetic film (hereinafter, a magnetization fixed layer). And an anti-ferromagnetic film for pinning the magnetization of the magnetization pinned layer in this order, the MR head using a spin valve film exhibiting a giant magnetoresistive effect is a next-generation MR head. Is seen as promising.

In an MR head using a spin valve film,
Barkhausen noise due to the domain wall of the magnetization free layer and the reproduction fringes near both ends of the reproduction track are major issues for practical use. In order to solve such a problem, for example, as shown in the cross-sectional view observed from the medium facing surface side of FIG. 12, the outsides of both ends 1a, 1a of the spin valve film 1 outside the recording track width are removed by etching. A so-called abutt junction type MR head in which the hard magnetic films 2 are respectively arranged is proposed.

The spin valve film 1 shown in FIG. 12 is formed by laminating the magnetization free layer 4, the nonmagnetic film 5, the magnetization fixed layer 6 and the antiferromagnetic film 7 in this order from the substrate 3 side as described above. ing. Further, a pair of electrodes (reproducing electrodes) 8 for flowing a sense current to the spin valve film 1 are formed on the hard magnetic film 2.

In the Abutt Junction type MR head shown in FIG. 12, the magnetic domain of the magnetization free layer 4 disappears by the bias magnetic field from the hard magnetic film 2 and Barkhausen noise is suppressed. Further, since the portion other than the recording track width is replaced with the hard magnetic film 2, only the recording information from the recording track can be read. Therefore, the reproduction fringe can be significantly reduced.

However, the MR head in which the above-mentioned abut junction method is applied to the spin valve film 1 has the following problems. First, although not shown, a gap film made of a non-magnetic insulator such as alumina exists below the spin valve film 1.
Therefore, the contact between the reproducing electrode 8 or the hard magnetic film 2 and the spin valve film 1 becomes the wall surface of the spin valve film 1 which is mainly removed by etching or the like. Therefore, there is a problem that the contact resistance is likely to increase or become unstable.

Secondly, when the magnetization free layer 4 is removed at both ends of the spin valve film 1 by etching, the magnetization free layer 4 exists at the lowermost portion, and therefore the gap film is inevitably over-etched. . Therefore, there is a problem that insulation failure is likely to occur between the magnetic shield layer existing under the gap film.

Thirdly, in the etching of the spin valve film 1, the taper tends to become gentler in the lower part than in the upper part of the spin valve film 1. Therefore, the area where the hard magnetic film 2 and the magnetization free layer 4 are exchange-coupled in the tapered portion increases. In such a tapered region, the exchange bias force becomes unstable, and Barkhausen noise is likely to occur.

Fourthly, since the wall surface of the hard magnetic film 2 and the wall surface of the magnetic pinned layer 6 are necessarily in contact with each other, the bias magnetic field from the hard magnetic film 2 is applied to the magnetic pinned layer 6 as well. Therefore, the magnetization of the magnetization pinned layer 6, which should be pinned in the width direction of the spin-valve film 1 (signal magnetic field inflow direction), is biased in the hard magnetic film 2 (longitudinal direction of the spin-valve film 1).
Therefore, there is a problem in that a good linear response to the signal magnetic field cannot be obtained.

On the other hand, there is also proposed an MR head in which a bias magnetic field applying film such as a hard magnetic film or an antiferromagnetic film is directly laminated on the edge portion of the MR film and exchange-coupled to remove Barkhausen noise. ing. However, in the existing spin-valve film in which the magnetization pinned layer is present on the magnetization free layer, it is necessary to provide a hard magnetic film, an antiferromagnetic film, or the like on the substrate side. However, there are problems such as deterioration of the surface property.

In particular, it is necessary to thicken the hard magnetic film and the antiferromagnetic film in order to obtain stable exchange coupling, but when they are thick, the pattern formation without deteriorating the surface condition of the base of the spin valve film is possible. Very difficult to do. Further, since it is difficult to obtain a strong exchange bias in the antiferromagnetic film and the coercive force is likely to decrease in the hard magnetic film due to the reaction from the magnetization free layer, stable magnetization fixation at the track width end is difficult. Therefore, there is a problem that reduction of reproduction fringes and suppression of Barkhausen noise are likely to be insufficient.

[0012]

As described above, in the conventional MR head using the spin valve film, the contact resistance is increased or destabilized, the insulation is defective, and the hard head is hardened by the shape of the Abutt Junction method. There is a problem that destabilization of exchange coupling between the magnetic film and the magnetization free layer is likely to occur. Further, there is a problem that a good linear response to the signal magnetic field cannot be obtained due to the inclination of the magnetization of the magnetization pinned layer.

On the other hand, in an MR head in which a bias magnetic field applying film such as a hard magnetic film or an antiferromagnetic film is directly laminated and exchange-coupled with the spin valve film, the surface condition of the underlayer of the spin valve film is deteriorated or the track condition is deteriorated. Since it is difficult to stably fix the magnetization at the width end, there is a problem that the reproduction fringe is reduced and the Barkhausen noise is not sufficiently suppressed.

Further, application of the spin valve film to a magnetic memory device such as a magnetoresistive effect memory (MRAM) is being considered, and even in such a case, a sufficient bias force is required.

The present invention has been made in order to address such a problem, and realizes reduction of contact resistance, suppression of insulation failure, and good linear response while suppressing reproduction fringe and Barkhausen noise. By using the magnetoresistive effect element, and further using such a magnetoresistive effect element,
An object of the present invention is to provide a magnetic head, a magnetic recording / reproducing head and a magnetic storage device having improved characteristics.

[0016]

According to a first magnetoresistive effect element of the present invention, as described in claim 1, a substrate and an anti-reverse layer formed on the main surface of the substrate in order from the substrate side. A magnetoresistive effect film having a magnetic multilayer film exhibiting a giant magnetoresistive effect, which includes at least a ferromagnetic film, a first ferromagnetic film, a nonmagnetic film, and a second ferromagnetic film arranged in a magnetic field detection unit, A pair of bias magnetic field applying films which are adjacent to both ends of the magnetic field detecting unit and are respectively laminated on the conductive film selected from the antiferromagnetic film, the first ferromagnetic film and the non-magnetic film in the magnetic multilayer film. And a pair of electrodes for supplying a current to the magnetoresistive film.

A second magnetoresistive effect head is defined in claim 10.
As described above, a substrate and at least a main surface of the substrate including at least an antiferromagnetic film, a first ferromagnetic film, a non-magnetic film, and a second ferromagnetic film, which are sequentially stacked from the substrate side. It has a magnetic multilayer film showing a giant magnetoresistive effect,
A magnetoresistive film having a portion corresponding to the magnetic field detecting portion and a portion outside both ends of the magnetic field detecting portion having a film thickness smaller than the portion corresponding to the magnetic field detecting portion; It is characterized in that it comprises a pair of bias magnetic field applying films respectively laminated on outer portions of both ends of the magnetic field detecting portion of the film, and a pair of electrodes for supplying a current to the magnetoresistive effect film.

The third magnetoresistive element is a substrate, an antiferromagnetic film laminated on the main surface of the substrate in order from the substrate side, and a first ferromagnetic element. A magnetoresistive film having a magnetic multilayer film exhibiting a giant magnetoresistive effect including at least a film, a non-magnetic film, and a second ferromagnetic film, and the second magnetic film on both outer sides of the magnetic field detection unit of the magnetoresistive film. A pair of bias magnetic field applying films respectively laminated on the ferromagnetic film and a pair of electrodes supplying a current to the magnetoresistive film.

According to a twenty-fourth aspect of the present invention, there is provided a magnetic head according to the above-mentioned present invention, wherein the magnetic head is formed on the lower magnetic shield layer and a lower reproducing magnetic gap on the lower magnetic shield layer. It is characterized by comprising a magnetoresistive effect element and an upper magnetic shield layer formed on the magnetoresistive effect element via an upper reproducing magnetic gap. According to a twenty-fifth aspect of the present invention, there is provided a magnetic recording / reproducing head including a reproducing head having the above-described magnetic head of the present invention, and a lower magnetic pole shared with the lower magnetic shield layer of the magnetic head. A recording head having a recording magnetic gap formed on the lower magnetic pole and an upper magnetic pole provided on the recording magnetic gap is provided.

According to a twenty-sixth aspect of the present invention, there is provided a magnetic memory device including the above-described magnetoresistive effect element of the present invention.
A write electrode for storing information in the magnetoresistive effect film of the magnetoresistive effect element, and a read electrode for reproducing the information stored in the magnetoresistive effect film, which is composed of the electrode of the magnetoresistive effect element. Is characterized by. In the first magnetoresistive effect element of the present invention, the first ferromagnetic film, to which magnetization is fixed by applying a bias magnetic field from the antiferromagnetic film, is arranged on the substrate side, and the magnetization free layer is arranged on the side opposite to the substrate. The second ferromagnetic film is formed. Therefore, the second ferromagnetic film on both outer sides of the magnetic field detector is removed to obtain good off-track characteristics (low reproduction fringe), and
It is possible to realize a structure in which a part of the conductive film in the magnetic multilayer film is left outside both ends of the magnetic field detection unit (reproduction track). This makes it possible to ensure stable electrical contact.

Further, since the taper region which makes the exchange coupling between the antiferromagnetic film and the second ferromagnetic film unstable can be made small, Barkhausen noise can be stably suppressed. In addition, it is possible to apply a bias magnetic field to the second ferromagnetic film without contacting the end wall surface of the first ferromagnetic film, which is the magnetization fixed layer, with the bias magnetic field applying film. Therefore, good linear response can be obtained while suppressing the generation of Barkhausen noise.

In the second magnetoresistive head of the present invention, the first ferromagnetic film, to which the magnetic field is applied by applying the bias magnetic field from the antiferromagnetic film is arranged on the substrate side, is arranged on the side opposite to the substrate. A second ferromagnetic film to be a magnetization free layer is arranged. Therefore, there is no fear of disturbing the underlying surface of the spin valve film by patterning the bias magnetic field applying film, and stable spin valve film characteristics can be realized.

Further, the film thickness of the outer portions of both ends of the magnetic field detecting portion of the second ferromagnetic film is made thinner than that of the magnetic field detecting portion.
Therefore, an increase in exchange bias force can be expected in a bias magnetic field applying film made of an antiferromagnetic film. On the other hand, a bias magnetic field applying film made of a hard magnetic film can be expected to increase the coercive force. By these, the magnetization fixation in the outer portions of both ends of the magnetic field detection portion of the second ferromagnetic film is further stabilized, Barkhausen noise is suppressed, and good off-track characteristics (low reproduction fringe) are obtained. You can Further, since the magnetization direction of the first ferromagnetic film, which is the magnetization fixed layer, is not disturbed, good linear response can be realized.

In the third magnetoresistive head of the present invention, the first ferromagnetic film, to which magnetization is fixed by applying a bias magnetic field from the antiferromagnetic film, is arranged on the side of the substrate, and on the side opposite to the substrate. A second ferromagnetic film to be a magnetization free layer is arranged. Therefore, there is no fear of disturbing the base of the spin valve film by patterning the bias magnetic field applying film, and stable spin valve film characteristics can be realized.

Further, by thinning the film thickness of the second ferromagnetic film, the exchange bias force can be expected to be increased in the bias magnetic field applying film made of the antiferromagnetic film. On the other hand, a bias magnetic field applying film made of a hard magnetic film can be expected to increase the coercive force. As a result, the magnetization fixation of the second ferromagnetic film at the outer portions of both ends of the magnetic field detector is stabilized, Barkhausen noise is suppressed, and good off-track characteristics (low reproduction fringe) can be obtained. it can. Further, since the magnetization direction of the first ferromagnetic film, which is the magnetization fixed layer, is not disturbed, good linear response can be realized.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION Modes for carrying out the present invention will be described below.

FIGS. 1 and 2 are views showing the structure of an embodiment of a recording / reproducing separated magnetic head in which the first magnetoresistive effect element of the present invention is applied to a reproducing element section. FIG. 1 is a cross-sectional view of a recording / reproducing separated magnetic head as seen from the medium facing surface direction (x direction corresponds to the recording track width direction, y direction corresponds to the recording track traveling direction and corresponds to the film thickness direction of the magnetoresistive element). . Figure 2
FIG. 3 is a cross-sectional view showing an enlarged main part thereof.

In these figures, 11 is a substrate,
As the substrate 11, Al ₂ O ₃ having an Al ₂ O ₃ layer is used.
-A TiC substrate or the like is used. A lower magnetic shield layer 12 made of a soft magnetic material such as a NiFe alloy, a FeSiAl alloy, or an amorphous CoZrNb alloy is formed on the main surface of the substrate 11. A magnetoresistive effect film (GMR film) 14 having a giant magnetoresistive effect is formed on the lower magnetic shield layer 12 through a lower reproducing magnetic gap 13 made of a nonmagnetic insulating material such as AlO _x .

As shown in FIG. 2, the magnetic multi-layer film constituting the GMR film 14 is an antiferromagnetic film 15, a first ferromagnetic film 16, which are sequentially formed on the lower reproducing magnetic gap 13.
It has at least a nonmagnetic film 17 and a second ferromagnetic film 18. This GMR film 14 is a so-called spin valve G
It is an MR film. In the magnetic multilayer film constituting the spin valve GMR film 14, the first ferromagnetic film 16 is a magnetization pinned layer whose magnetization is pinned by the bias magnetic field from the antiferromagnetic film 15 formed therebelow. On the other hand, the second ferromagnetic film 18 is a magnetization free layer that rotates magnetization according to an external magnetic field such as a signal magnetic field. In addition, reference numeral 19 in the drawing denotes a protective film made of Ta, Ti, or the like, which is formed as necessary.

The magnetization of the first ferromagnetic film 16 is preferably fixed by the antiferromagnetic film 15 in a direction substantially perpendicular to the medium facing surface (parallel to the paper surface) (direction perpendicular to the paper surface). The magnetization of the second ferromagnetic film 18 is preferably oriented substantially in the track width direction when the external magnetic field is zero. That is, it is preferable that the magnetization direction of the first ferromagnetic film 16 and the magnetization direction of the second ferromagnetic film 18 be substantially orthogonal to each other. The second ferromagnetic film 18 is biased by a pair of hard magnetic films 20, which will be described in detail later, and is generally oriented in the track width direction when the external magnetic field is zero as described above. Magnetic domains disappear in the magnetic field.

These ferromagnetic films 16 and 18 have Co and C
oFe alloy, CoFeB alloy, NiFe alloy, CoNi
Alloys, NiFeCo alloys, etc. are used. For example, in order to obtain heat resistance and long-term reliability in the recording portion forming process of the resistance change rate, it is preferable to use a Co-based alloy such as CoFe. The thickness of the ferromagnetic films 16 and 18 is preferably, for example, about 0.5 to 10 nm for the first ferromagnetic film 16 and about 1 to 20 nm for the second ferromagnetic film 18.

A non-magnetic film 17 made of Cu, Au, Ag, or an alloy thereof is interposed between the first and second ferromagnetic films 16 and 18. Each of the layers 15, 16, 17, and 18 including the antiferromagnetic film 15 constitutes a basic element of the spin valve GMR film 14. Non-magnetic film 1
It is preferable that the film thickness of 7 is, for example, about 0.5 to 10 nm. The antiferromagnetic film 15 includes a conductive IrMn alloy, Rh.
Mn alloy, RuMn alloy, PdPtMn alloy, CrMn
Pt alloy, FeMn alloy, NiMn alloy, PtMn alloy or the like, or insulating NiO or CoO or the like is used.

The spin valve GMR film 14 composed of the above-mentioned magnetic multilayer film has a shape corresponding to at least the second ferromagnetic film 18 corresponding to a magnetic field detecting section (reproducing track) for detecting an external magnetic field such as a signal magnetic field. There is. In other words, at least the second ferromagnetic film 18 has a shape in which both ends outside the recording track width are removed so that the length in the x direction becomes a desired track width. Further, the removal range in the film thickness direction of the magnetic multilayer film is set so that the conductive multilayer film exists in the magnetic multilayer film at the uppermost portions of the outer portions on both ends of the reproduction track. The non-magnetic film 17 is used as the conductive film located at the uppermost part on the outer side of both ends of the reproduction track.
And the first ferromagnetic film 16. When an IrMn alloy or FeMn alloy having conductivity is used as the antiferromagnetic film 15, the antiferromagnetic film 15 may be a conductive film located at the top.

In order to allow the conductive films other than the second ferromagnetic film 18 to be present at the outer portions of both ends of the reproduction track, ion milling using a resist mask is performed on the magnetic multilayer film formed by the sputtering method or the like. The above may be performed to remove at least the second ferromagnetic film 18. FIG. 2 shows a state in which the magnetic multilayer film is etched so that a part of the nonmagnetic film 17 remains. A part of the non-magnetic film 17 remains on the uppermost portions of the outer portions on both ends of the reproduction track.

Then, at least the second ferromagnetic film 18 is removed, and a pair of hard magnetic layers are formed on the conductive film in the magnetic multilayer film at the outer portions of both ends of the reproducing track where the conductive film exists on the uppermost part. The film 20 is laminated as a bias magnetic field applying film. That is, the nonmagnetic film 17 having conductivity is in contact with the hard magnetic film 20. A hard magnetic material having conductivity such as a CoPt alloy or a CoNiCr alloy is used for the pair of hard magnetic films 20 and has a thickness of 10
It is preferably about 80 nm. A pair of hard magnetic films 2
A pair of electrodes 21 made of Cu, Au, Zr, Ta, or the like is formed on each of the electrodes 0.
As a result, a sense current is supplied to the spin valve GMR film 14. The interval between the pair of electrodes 21 may be set narrower than the interval between the pair of hard magnetic films 20.

The spin valve GMR film 14, the pair of hard magnetic films 20 and the pair of electrodes 21 described above constitute a GMR reproducing element 22. On the GMR reproducing element 22,
As shown in FIG. 1, an upper magnetic shield layer 24 made of a soft magnetic material similar to the lower magnetic shield layer 12 is interposed via an upper read magnetic gap 23 made of a non-magnetic insulating material similar to the lower read magnetic gap 13. Are formed. These constitute a shield type GMR head 25 as a reproducing head.

The bias magnetic field applying film is not limited to the hard magnetic film 20, but a laminated film 28 in which an antiferromagnetic film 27 is laminated on a ferromagnetic film 26 is applied as in the first modification shown in FIG. It is also possible. Ferromagnetic film 26 and antiferromagnetic film 27
The stacking order of and may be reversed. For the ferromagnetic film 26, a NiFe alloy, a Co alloy, or the like is used. N for the antiferromagnetic film 27
An iMn alloy, FeMn alloy, IrMn alloy, PtMn alloy or the like is used. Since the magnetization of the ferromagnetic film 26 is firmly fixed by the strong unidirectional exchange coupling bias magnetic field from the antiferromagnetic film 27, the laminated film 28 becomes the hard magnetic film 20.
And functions as a bias magnetic field applying film.

It is desirable that the antiferromagnetic film 27 in the bias magnetic field applying film and the antiferromagnetic film 15 in the spin valve GMR film have their bias magnetic field directions substantially orthogonal to each other. For example,
By selecting the antiferromagnetic film 27 and the antiferromagnetic film 15 so as to have different blocking temperatures and performing heat treatment in a magnetic field, the bias magnetic field directions can be made substantially orthogonal to each other.
The blocking temperature can be changed depending on the material, composition, film forming conditions and the like. An example of conditions for heat treatment in a magnetic field is shown below.

The antiferromagnetic film 27 has a blocking temperature.
Antiferromagnetic film 1 using 503K IrMn alloy (film thickness 5.5 nm)
A PtMn alloy with a blocking temperature of 653K is used for 5. First, the magnetization of the antiferromagnetic film 15 is fixed in the direction perpendicular to the medium facing surface in a unidirectional magnetic field (several 10 Oe, direction is perpendicular to the medium facing surface) at 523K for 5 hours. Next, in the cooling process, the magnetic field direction is rotated by approximately 90 ° in the track width direction at a temperature intermediate between the blocking temperatures of the antiferromagnetic film 27 and the antiferromagnetic film 15 (up to 513K). Then, the magnetization of the ferromagnetic film 26 is fixed in the track width direction by the bias magnetic field of the antiferromagnetic film 27 during the cooling process.

On the shield type GMR head 25, as shown in FIG.
As shown in, a thin film magnetic head 29 is formed as a recording head. The lower recording magnetic pole of the thin film magnetic head 29 is composed of the same magnetic layer as the upper magnetic shield layer 24. That is, the upper magnetic shield layer 24 of the shield type MR head 25 also serves as the lower recording magnetic pole of the thin film magnetic head 29. A recording magnetic gap 30 made of a nonmagnetic insulating material such as AlO _x and an upper recording magnetic pole 31 are sequentially formed on the lower recording magnetic pole 24 which also serves as the upper magnetic shield layer. Although illustration is omitted, a recording coil for applying a recording magnetic field to the lower recording magnetic pole 24 and the upper recording magnetic pole 31 is formed on the rear side of the medium facing surface, and a thin film magnetic head 29 as a recording head is configured. There is.

The shield type GMR head 25 whose main part is shown in FIG. 2 is manufactured, for example, as follows.

That is, first, the lower reproducing magnetic gap 13
Spin valve GM on the main surface of the substrate 11 formed up to
Each film forming the R film 14 is sequentially formed by a sputtering method or the like. Then, a photoresist mask is formed and the spin valve GMR film 14 is etched into a predetermined shape by ion milling or the like. This etching removes at least the second ferromagnetic film 18 and leaves a part of the conductive unit film in the magnetic multilayer film forming the spin valve GMR film 14.

Next, using the photoresist used for etching the spin valve GMR film 14, a pair of hard magnetic films 20 and electrodes 21 and the like are sputtered on the outer portions of both ends of the reproducing track of the spin valve GMR film 14. Etc. to form a film. The photoresist is removed using a solvent such as acetone.

Next, a photoresist mask corresponding to the shapes of the hard magnetic film 20 and the electrode 21 is formed, and ion milling is performed using these. As a result, for example, FIG.
A pattern as shown in FIG. Below the hard magnetic film 20 and the electrode 21, there is a conductive film in the magnetic multilayer film forming the spin valve GMR film 14. After that, the upper reproducing magnetic gap 23 and the upper magnetic shield layer 24 are formed to complete the shield type GMR head 25.

Further, after forming a thin film magnetic head 29 as a recording head on the shield type GMR head 25,
The recording / reproducing separated magnetic head is completed by machining slider shape and head gimbal assembly.

In the GMR head 25 of the above-described embodiment, the magnetization free layer, that is, the second ferromagnetic film 18 is present on the upper side opposite to the substrate 11. For this reason, firstly good off-track characteristics (low reproduction fringe)
The removal of the magnetization free layer on the outer side of both ends deviated from the reproduction track, which is necessary for obtaining
It can be carried out without completely removing the R film 14. In addition, a structure in which a part of the conductive film is left outside the both ends can be realized. As a result, stable electrical contact is secured through the remaining conductive film, and stable and small contact resistance can be realized. Therefore, the resistance of the entire GMR reproducing element 22 can be reduced, and even if a large sense current is applied to increase the reproducing sensitivity, it is less likely to be affected by thermal noise.

Secondly, since at least only the second ferromagnetic film 18, which is the magnetization free layer, needs to be etched, the etching amount can be reduced and the etching accuracy can be improved. Thirdly, the taper of the spin-valve GMR film 14 tends to be gentle in the lower portion where the etching progresses, whereas the taper becomes steep in the second ferromagnetic film 18 at the beginning of the etching progress. Therefore, it is possible to reduce the taper region that causes Barkhausen noise. As a result, Barkhausen noise can be stably suppressed.

Fourthly, the second ferromagnetic film 18 is biased from the hard magnetic film 20 without contacting the end wall surface of the first ferromagnetic film 16 which is the magnetically pinned layer with the hard magnetic film 20. A magnetic field can be applied. Therefore, it is possible to suppress the generation of Barkhausen noise and also suppress the leakage magnetic field applied from the hard magnetic film 20 to the magnetization fixed layer. As a result, it is possible to avoid the problem that the magnetization of the first ferromagnetic film 16 is inclined in the leakage magnetic field direction of the hard magnetic film 20. The magnetization direction of the first ferromagnetic film 16 is stably fixed in the width direction of the spin valve GMR film 14 (inflow direction of the signal magnetic field), and good linear response is obtained.

The GMR head 25 of this embodiment has characteristics such as good off-track characteristics, small reproduction fringe, little Barkhausen noise and thermal noise, and good linear response. It is possible to realize a reproducing characteristic with a good N ratio.

In the above embodiment, the spin valve GM is used.
The case where the R film 14 is composed of a basic magnetic multilayer film including the antiferromagnetic film 15, the first ferromagnetic film 16, the nonmagnetic film 17 and the second ferromagnetic film 18 has been described. Other layers can be added to the magnetic multilayer film constituting the spin valve GMR film 14 depending on the constituent material of each layer and the like.

For example, in the spin valve structure of the present invention in which the laminated structure is reversed as compared with the conventional spin valve structure in which the magnetization free layer, the non-magnetic film, the magnetization pinned layer and the antiferromagnetic film are laminated in order, IrMn If the metal antiferromagnetic film 15 such as an alloy or FeMn alloy is simply used, the bias magnetic field from the antiferromagnetic film 15 to the first ferromagnetic film 16 may be weakened. Therefore, for example, as shown in FIG. 5, in order to improve the stability of the fcc phase of the antiferromagnetic film 15 and the (111) crystal orientation, and the stability of the fcc phase of the ferromagnetic film 16, the antiferromagnetic film 15 is used. It is preferable to provide the underlayer film 32. As the base film 32, Ta, Zr, Nb, Hf, etc. may be used, but especially NiFe alloy having a fcc phase, NiFeX
Alloy (X: Cr, Nb, Ta, Zr, Hf, W, Mo,
V, Ti, Rh, Ir, Cu, Au, Ag, Mn, R
e, at least one element selected from Ru), CuN
i alloy or the like is preferable. The thickness of the base film 32 is 1 to 20 nm
It is preferable to set the degree.

In particular, the antiferromagnetic film 15 made of the IrMn alloy containing Ir in the range of 5 to 40% by weight formed through the underlayer film 32 has a blocking temperature T _{B at} which the bias magnetic field disappears of 473K. As described above, the heat resistance is excellent and a high bias magnetic field can be obtained, which is desirable. I
The thickness of the antiferromagnetic film 15 made of the rMn alloy is preferably about 3 to 30 nm. If it is thinner than this, a sufficient bias magnetic field cannot be obtained, and if it is thicker than this, the antiferromagnetic film 15 is formed.
There is a high possibility that the shunting of the sense current to the transistor increases and the rate of resistance change decreases.

IrMn alloy or FeMn is used for the antiferromagnetic film 15.
When a conductive material such as an alloy is used, as in the second modified example shown in FIG. 5, the outer portions of both ends of the reproducing track of the spin valve GMR film 14 are formed until at least a part of the antiferromagnetic film 15 remains. The hard magnetic film 20 may be removed by etching and laminated on the antiferromagnetic film 15 having conductivity. Even if etching is performed to reach the antiferromagnetic film 15, the conductive film is not likely to disappear, so that the conductive film can be stably left. Therefore, the contact resistance between the electrode 21 including the hard magnetic film 20 and the spin valve GMR film 14 can be reduced with good reproducibility.

On the other hand, when the insulating NiO or the like is used for the antiferromagnetic film 15, as shown in FIG. 1, the hard magnetic film 2 is used.
As the conductive film in the spin valve GMR film 14 below 0, both the first ferromagnetic film 16 and the non-magnetic film 17, or only the first ferromagnetic film 16 may be present. As a result, the electrode 21 including the hard magnetic film 20 and the spin-valve GMR film 1 are different from the conventional electrical contact by the wall surface.
4 can be electrically contacted well.

Further, as shown in FIG. 5, for example, CoP
Below the hard magnetic film 20 made of a t-alloy or the like, in order to increase the coercive force by inclining the c-axis as much as possible in the in-plane direction, Cr, V, CrV alloy, FeC having a thickness of about 1 to 20 nm are provided.
It is desirable to provide a base film 33 made of an o alloy or the like.

At the interface between the antiferromagnetic film 15 and the first ferromagnetic film 16 which is the magnetization fixed layer, in order to increase the exchange bias magnetic field from the antiferromagnetic film 15 to the first ferromagnetic film 16. Alternatively, a magnetic film having a lattice constant intermediate between these may be inserted. As such a magnetic film, for example, the antiferromagnetic film 15 is a FeMn alloy and the first ferromagnetic film 16 is CoFe.
When it is an alloy, a CoFePd alloy or the like can be used.
When a Co-based alloy such as a CoFe alloy or CoFeB alloy is used for the first ferromagnetic film 16 and the second ferromagnetic film 18,
An extremely thin NiFe-based layer having a thickness of, for example, about 0.5 to 3 nm may be inserted between the antiferromagnetic film 15 and the antiferromagnetic film 15. The NiFe-based ultrathin layer stabilizes the fcc phase of the Co-based alloy and reduces the coercive force of the Co-based alloy. Therefore, it becomes easy to obtain a high-sensitivity reproduction output without Barkhausen noise.

Further, as in the third modified example shown in FIG. 6, a thickness of 0.5 to 5 nm made of Ni or a Ni-based alloy or the like is provided between the antiferromagnetic film 15 and the first ferromagnetic film 16. The magnetic barrier layer 34 may be inserted to provide the diffusion barrier layer 35 between the first ferromagnetic film 16 and the magnetic layer 34. The diffusion barrier layer 35 densifies the film growth of the first ferromagnetic film 16 and the nonmagnetic film 17. As a result, a thermally stable interface can be realized between the first ferromagnetic film 16 and the nonmagnetic film 17, which is essential for obtaining a large resistance change rate. The diffusion barrier layer 35 is formed by forming a magnetic layer 34 by a sputtering method or the like and then introducing a slight amount of oxygen (about 1 to 10 SCCM) into the sputtering atmosphere (1
˜300 seconds), and the surface of the magnetic layer 34 is oxidized to a thickness of 3 nm or less at which exchange coupling works. The treatment for forming the diffusion barrier layer 35 may be a nitriding treatment, a fluorination treatment, a carbonization treatment, or the like. Alternatively, after the magnetic layer 34 is formed, the film may be exposed to the atmosphere and then formed.

An alloy containing a large amount of Ni such as a NiFe alloy is used for the first ferromagnetic film 16 and the second ferromagnetic film 18.
When Cu is used for the non-magnetic film 17, the non-magnetic film 1
It is preferable to insert an extremely thin Co or Co-based alloy film having a thickness of, for example, about 1.5 nm or less at the interface in contact with 7. As a result, diffusion between Ni and Cu can be prevented, and the rate of resistance change and heat resistance can be secured.

As shown in FIG. 5, a soft magnetic assist film 36 is formed on the second ferromagnetic film 18, if necessary. The soft magnetic assist layer 36 is not always necessary when an alloy containing a large amount of Ni having good soft magnetism is used for the second ferromagnetic film 18 which is the magnetization free layer. When a Co-based alloy such as CoFe alloy is used, NiFe alloy, NiF
eX (X: Cr, Nb, Ta, Zr, Hf, W, Mo,
V, Ti, Rh, Ir, Cu, Au, Ag, Mn, R
At least one element selected from e and Ru) crystalline magnetic alloys such as alloys, CoZrNb series, CoFeRe series, C
Amorphous magnetic alloy such as oFeAlO, FeZr
N, Nitride microcrystalline alloy such as CoFeTaN, CoNbC,
It is desirable to form the soft magnetic assist film 36 made of a carbide microcrystalline alloy such as FeTaV or a laminated film thereof.

The soft magnetic assist film 36 is effective in improving the soft magnetism of the second ferromagnetic film 18 made of a Co type alloy. The thickness of the soft magnetic assist film 36 is preferably about 1 to 15 nm. It is desirable to use a high-resistance magnetic film as the soft magnetic assist film 36 in order to suppress the shunt of the sense current and maintain a high resistance change rate. Specifically 50μ
It is preferable to use a magnetic film of Ωcm or more.

Regarding the shapes of the hard magnetic film 20 and the electrode 21, for example, in the following cases, the distance between the pair of hard magnetic films 20 and the distance between the pair of electrodes 21 are approximately the same. This is because the hard magnetic film 20 and the electrode 21 are continuously formed by using the resist mask used for patterning the spin valve GMR film 14 as it is, and after removing the resist mask (so-called lift-off), the electrode shape is formed. This is a case where a resist mask adapted to the above is formed and etched by ion milling or the like. At this time, the above-mentioned interval becomes almost the reproduction track width.

On the other hand, the spin valve GMR film 14 is formed by making the distance between the electrodes 21 wider than the distance between the pair of hard magnetic films 20.
In the vicinity, the hard magnetic film 20 can be used as a part of the electrode. For example, by forming the hard magnetic film 20 and the electrodes 21 separately, the gap between the pair of electrodes 21 is made wider than the gap between the pair of hard magnetic films 20 as shown in FIG. 21 may be retracted from the medium facing surface.

According to this structure, since the electrode 21 is formed at the position retracted from the medium facing surface, the electrode 21 is directly exposed to the machining process for exposing the spin valve GMR film 14 to the medium facing surface. Never. Cu and Au
Even if a soft low-resistance material such as is used for the electrode 21, the shape of the electrode 21 on the medium facing surface (ABS) side is expanded by polishing, and electrode deterioration such as insulation failure between the magnetic shield layers 12 and 24 is avoided. can do. in this case,
Since the hard magnetic film 20 also serves as an electrode in the vicinity of the spin valve GMR film 14, it is preferable to increase its thickness in order to reduce the resistance of the hard magnetic film 20 as much as possible. Hard magnetic film 2
The film thickness of 0 is preferably about 40 to 100 nm. Next, an embodiment of a GMR head to which the second magnetoresistive effect element of the present invention is applied will be described with reference to FIG. FIG. 8 is a sectional view showing a main part of the GMR head of this embodiment. The overall structure of the GMR head 25 is as shown in FIG. Furthermore, when the second magnetoresistive element of the present invention is applied to the reproducing element section to form a recording / reproducing separated magnetic head, the overall structure is the same as that shown in FIG.

In the GMR head whose main part is shown in FIG.
The spin-valve GMR film 14 is similar to the one described above in that the base film 32, the antiferromagnetic film 15, the first ferromagnetic film 16, the non-magnetic film 17, the second ferromagnetic film 18, and the soft film 18 which are sequentially stacked from the substrate side. It is composed of a magnetic multilayer film having a magnetic assist film 36 and a protective film 19. Of these, the base film 3
2, the soft magnetic assist film 36, the protective film 19, etc. are formed as needed. Further, similarly to the above-described embodiment, it is possible to interpose a layer other than these layers.

In the GMR head of this embodiment, the second ferromagnetic film 18 has a film thickness t at the outer end portions of both ends of the reproducing track as compared with the film thickness t ₁ of the portion corresponding to the magnetic field detecting portion (reproducing track). ₂ is set thinly. The bias magnetic field imparting film 37 is formed on the portion of the second ferromagnetic film 18 having a film thickness t ₂ .
That is, they are laminated and formed on the outer portions at both ends of the reproduction track having the film thickness t ₂ . In other words, in the second ferromagnetic film 18, the film thickness t ₂ of the portion below the bias magnetic field applying film 37 is set to be smaller than the film thickness t ₁ of the portion corresponding to the magnetic field detecting portion. The electrode 21 is laminated on the bias magnetic field applying film 37.

When the magnetization free layer is composed of a laminated film of the second ferromagnetic film 18 and the soft magnetic assist film 36, the thickness of this laminated film is the thickness of the reproducing track below the bias magnetic field applying film 37. The outer portions of both ends may be thinner than the portion corresponding to the magnetic field detection unit. The configuration other than the spin valve GMR film 14 is the same as that of the above-described embodiment.

In the GMR head of this embodiment, the outer portions of both end portions of the reproducing track are etched only up to a part of the second ferromagnetic film 18 which is the magnetization free layer, so the etching amount is small. Therefore, the etching is not limited to ion milling, and simpler reverse sputter etching may be applied.

The bias magnetic field applying film 37 is made of, for example, Ni.
Mn alloy, FeMn alloy, IrMn alloy, PdPtMn
Alloy, RhMn alloy, RuMn alloy, PtMn alloy, C
An antiferromagnetic film having conductivity such as rMnPt alloy or a hard magnetic film having conductivity such as CoPt alloy is used. Further, similar to the structure shown in FIG.
It is also possible to apply the laminated film 28 of 6 and the antiferromagnetic film 27 to the bias magnetic field applying film 37.

When an antiferromagnetic film is applied to the bias magnetic field applying film 37, its film thickness is preferably 3 to 70 nm. More specifically, in the case of NiMn alloy, it should be 25 nm or more, in the case of FeMn alloy, 5 nm or more, IrM
In the case of an n alloy, 3 nm or more is preferable, and in the case of a PdPtMn alloy, 5 nm or more is desirable in order to obtain a stable exchange bias.

Here, FIG. 9 shows the relationship between the exchange bias and the thickness of the magnetic film that gives the exchange bias in the antiferromagnetic film, using an IrMn alloy as an example. It can be seen from FIG. 9 that the exchange bias sharply improves as the thickness of the magnetic film decreases. The same applies to the other antiferromagnetic films. Therefore, the magnetization free layer existing under the antiferromagnetic film as the bias magnetic field applying film 37, that is, the second ferromagnetic film 18 or the laminated film of the second ferromagnetic film 18 and the soft magnetic assist film 36 is formed. The exchange bias can be increased by reducing the film thickness at the outer portions of both ends of the reproduction track.

Specifically, the thickness of the magnetization free layer below the antiferromagnetic film as the bias magnetic field applying film 37 is 2 to 5 nm.
It is preferable to set the degree. As a result, the change in magnetization directly below the antiferromagnetic film (37) due to the signal magnetic field from the medium can be made substantially zero, and the reproduction fringe can be reduced. Further, an appropriate bias magnetic field is applied to the second ferromagnetic film 18 serving as the magnetization free layer, so that Barkhausen noise can be stably suppressed.

When an antiferromagnetic film is used as the bias magnetic field applying film 37, the lattice constant between this antiferromagnetic film and the second ferromagnetic film 18 or the soft magnetic assist film 36 is a strong intermediate value. Insertion of a magnetic film or an antiferromagnetic film is desirable for increasing the strength of the exchange bias. For example, a CoFe alloy is used for the second ferromagnetic film 18, and FeMn is used for the antiferromagnetic film as the bias magnetic field applying film 37.
When using an alloy, it is desirable to insert an intermediate ferromagnetic film in which an additive element such as Pd is added to CoFe so that the lattice constant is close to that of an FeMn alloy.

On the other hand, when a hard magnetic film is applied to the bias magnetic field applying film 37, the hard magnetic film and the magnetization free layer (the second ferromagnetic film 18 or the second ferromagnetic film) existing below the hard magnetic film. 18 and the soft magnetic assist film 36 are laminated. The magnetic film thickness (product of residual magnetization Mr and film thickness t (Mr ×
It is preferable that t)) is at least twice the magnetic film thickness of the magnetization free layer existing under the hard magnetic film. This is because when the magnetic film thickness of the magnetization free layer relatively increases, the reaction of the magnetization free layer destabilizes the magnetization of the hard magnetic film (specifically, decreases the coercive force), and This is because the magnetization of the magnetization free layer is insufficiently stabilized by exchange coupling. In other words, by thinning the film thickness of the magnetization free layer existing under the hard magnetic film as the bias magnetic field applying film 37, the magnetization of the magnetization free layer in that portion is sufficiently stabilized, and the reproduction fringe is prevented. It can be reduced. The same applies to the case where the bias magnetic field applying film 37 is the laminated film 28 of the ferromagnetic film 26 and the antiferromagnetic film 27.

For example, C is used as the bias magnetic field applying film 37.
Second ferromagnetic film 1 using oPt alloy (Mr = 1T)
Taking a case where a CoFe alloy (Mr = 1.8T) is used as 8, for example, when the CoPt alloy film has a thickness of 18 nm and the CoFe alloy film has a thickness of 10 nm, the values of Mr × t are almost the same. Becomes The coercive force of 1500 Oe in the CoPt single layer film is CoFe
By stacking with an alloy film, it decreases to 700 Oe, which is about 1/2, but the film thickness of the CoFe alloy film becomes Mr × t = 2 4
When the thickness is nm (the CoPt thickness is the same), the coercive force when laminated with the CoFe alloy film is 1050 Oe, and the decrease in the coercive force is not so remarkable. As the bias magnetic field applying film 37, as shown in FIG. 3, a laminated film of an antiferromagnetic film and a ferromagnetic film may be used.

When a hard magnetic film is used as the bias magnetic field applying film 37, the c axis of the Co type hard magnetic film is oriented in the direction perpendicular to the film surface due to epitaxial crystal growth from the second ferromagnetic film 18. The coercive force of the hard magnetic film may decrease. In this case, an amorphous layer having a film thickness of about 1 to 10 nm is inserted between the second ferromagnetic film 18 and the hard magnetic film as the bias magnetic field applying film 37 to lower the coercive force of the hard magnetic film. Is preferably suppressed. This layer is, for example, a Cr film having a thickness of about 5 nm. In this Cr film, the initial layer having a thickness of about 2 nm is amorphous, and the upper layer having a thickness of about 3 nm is a crystalline layer.

In the GMR head of the second embodiment described above, the underlying surface of the spin valve film based on the patterning of the bias magnetic field applying film, which has been a problem in the conventional spin valve film having the magnetization free layer on the substrate side. Disturbance of can be prevented. Therefore, stable spin valve film characteristics can be realized.

Further, by making the film thickness of the magnetization free layer in the exchange coupling region outside both ends of the reproducing track smaller than that of the magnetic field detecting portion, the exchange bias force is increased in the bias magnetization imparting film made of an antiferromagnetic film. However, an increase in coercive force can be expected in a bias magnetization imparting film made of a hard magnetic film. Therefore, the magnetization fixation of the magnetization free layer at the target track end is more stabilized, and Barkhausen noise can be suppressed easily. Further, even when a bias magnetic field is applied by the hard magnetic film, since there is no direct contact with the magnetization pinned layer on the wall surface, the leakage magnetic field from the hard magnetic film adversely affects the magnetization direction of the magnetization pinned layer. Is less. As a result, there is no Barkhausen noise, and reproduction with excellent linear response can be realized.

Next, an embodiment of the GMR head to which the third magnetoresistive effect element of the present invention is applied will be described with reference to FIG. FIG. 10 is a sectional view showing the main part of the GMR head of this embodiment. The overall structure of the GMR head 25 is as shown in FIG. Further, when the third magnetoresistive effect element of the present invention is applied to the reproducing element section to form a recording / reproducing separated magnetic head, the entire structure is similar to that of FIG.

In the GMR head whose main part is shown in FIG. 10, the spin valve GMR film 14 is the antiferromagnetic film 15 and the first antiferromagnetic film 15 which are sequentially stacked from the substrate side as in the above-described embodiment.
Of the magnetic multilayer film including the ferromagnetic film 16, the non-magnetic film 17, the second ferromagnetic film 18, and the protective film 19. Note that, similarly to the above-described embodiment, it is possible to interpose a layer other than these layers.

At the outer side portions of the spin valve GMR film 14 which are out of the magnetic field detecting portion (reproducing track), the second
An antiferromagnetic film is provided on the ferromagnetic film 18 as a pair of bias magnetic field applying films 37. As the bias magnetic field applying film 37, an antiferromagnetic film having a blocking temperature different from that of the antiferromagnetic film 15 is used. The portion where the bias magnetic field imparting film 37 is laminated is formed in the same manner as in the second embodiment described above.
The outer portions of both ends of the reproduction track are etched to a part of the second ferromagnetic film 18, and the reduced thickness is used as a base film for the bias magnetic field applying film 37 and has the same strength as the second ferromagnetic film 18. A magnetic film may be formed.

The film thickness of the second ferromagnetic film 18 may be set to a thickness that can increase the exchange bias from the bias magnetic field applying film 37, as in the second embodiment described above. preferable. Specifically, the second ferromagnetic film 1
The film thickness of No. 8 is preferably about 2 to 10 nm. Also,
The thickness of the antiferromagnetic film as the bias magnetic field applying film 37 is preferably the same as that in the second embodiment.

On the spin valve GMR film 14 and the bias magnetic field applying film 37, the high resistance protective film 3 made of Ti or the like is formed.
A pair of electrodes 21 is formed on the high resistance protective film 38 on which the electrodes 8 are formed. The distance between the pair of electrodes 21 is
It is patterned so as to be narrower than the distance between the pair of bias magnetic field applying films 37. In the patterning of the electrode 21 by ion milling, RIE or the like, the high resistance protective film 38 functions as an etching stopper. As a result, overetching of the spin valve GMR film 14 can be prevented.

When the distance between the pair of electrodes 21 is made narrower than the distance between the pair of bias magnetic field applying films 37, the pair of electrodes 21
The track width is defined by the interval. In such a structure, the low-sensitivity region in the vicinity of the bias magnetic field imparting film 37 is removed, so that a highly sensitive reproduction output can be obtained with a narrow track width. Note that the electrodes 21 may be formed at the same time as the formation of the bias magnetic field applying film 37, and lift-off patterning of these may be performed. In this case, the pair of bias magnetic field applying films 3
The distance between 7 and the pair of electrodes 21 is substantially equal. In the GMR head of the third embodiment described above, the disorder of the base of the spin valve film due to the patterning of the bias magnetic field applying film, which is a problem in the conventional spin valve film having the magnetization free layer on the substrate side, is prevented. be able to. further,
The high resistance protective film 38 can prevent over-etching of the spin valve GMR film 14 when the electrode 21 is patterned. Therefore, stable spin valve film characteristics can be realized.

Further, by thinning the thickness of the second ferromagnetic film 18 which is the magnetization free layer, the exchange bias force from the bias magnetization imparting film 37 made of an antiferromagnetic film can be increased. Therefore, the magnetization of the magnetization free layer is stabilized and Barkhausen noise is suppressed. As a result, there is no Barkhausen noise, and reproduction with excellent linear response can be realized.

In each of the embodiments described above, the case where the magnetoresistive effect element of the present invention is applied to the reproducing element part of the recording / reproducing separated magnetic head has been described, but the magnetoresistive effect element of the present invention is not limited to this. Not a thing. For example, the magnetoresistive effect element of the present invention can be applied to other head structures such as a recording / reproducing integrated magnetic head in which a pair of magnetic yokes are shared by a recording head and a reproducing head.

Next, an embodiment in which the magnetoresistive effect element of the present invention is applied to a magnetic storage device such as a magnetoresistive effect memory (MRAM), that is, an embodiment of the magnetic storage device of the present invention will be described.

FIG. 11 is a diagram showing the configuration of an embodiment of an MRAM utilizing the giant magnetoresistive effect (GMR). The MRAM 40 shown in the figure has a spin valve GMR film 42 formed on a substrate 41 such as a glass substrate or a Si substrate. The spin-valve GMR film 42 has an inverted laminated structure like the GMR heads of the above-described embodiments, and has a pair of bias magnetic field applying films 43 formed on the outer portions of both ends of the reproduction track. There is. Spin valve G
The laminated structure and the like of the MR film 42 and the bias magnetic field applying film 43 are the same as those shown in FIGS. 2, 3, 5, 6, 8 and 9.

A write electrode 45 is provided on the spin valve GMR film 42 with an insulating layer 44 interposed therebetween.
A pair of read electrodes 46 are provided on both ends of the spin valve GMR film 42, and a sense current is supplied to the spin valve GMR film 42 from the pair of read electrodes 46. Incidentally, reference numeral 47 in the drawing denotes a read auxiliary electrode.

Writing and reading of information in the MRAM 40 described above are performed as follows, for example. First, writing of information is performed by applying a current to the write electrode 45 to apply an external magnetic field, and setting the magnetization direction of the magnetization fixed layer to the direction corresponding to "1" or "0".

The readout of the stored information is performed by the readout electrode 46.
In the state in which the sense current is applied from, the positive and negative pulse currents are applied to the write electrode 45, and the magnetization direction of the magnetization free layer is reversed by the current magnetic field. With respect to the positive / negative of the write electrode 45, the magnetization direction of the magnetization free layer is constant regardless of "1" or "0" of the magnetization fixed layer. On the other hand, "1"
Alternatively, depending on the magnetization direction of the magnetization pinned layer 50 stored as “0”, the magnetization directions of the upper and lower ferromagnetic layers of the spin valve GMR film 42 are parallel when the pulse current of the write electrode 45 is positive and antiparallel when the magnetization direction is negative. Or writing electrode 4
It is determined whether the magnetization direction is parallel when the pulse current of 5 is negative and antiparallel when the pulse current is positive. Therefore, when, for example, a positive → negative pulse current is applied to the write electrode 45, "1" or "0" of the magnetization pinned layer is determined depending on whether the resistance of the sense current is large → small or small → large.

The bias magnetic field applying film 43 in the MRAM 40 controls the magnitude of the magnetic field in which the magnetization reversal of the magnetization free layer occurs when a positive and negative pulse current is applied to the write electrode 45, and in the state where magnetic domains are formed. The noise associated with the irregular magnetization reversal is suppressed. Here, with respect to the bias magnetization imparting film, it is important to obtain a biasing force sufficient to suppress an increase in demagnetizing field due to a small cell size, which is a thinner film corresponding to higher integration. As described in detail in each of the above-described embodiments, since the bias magnetic field imparting film according to the present invention can obtain a sufficient bias force, the MRAM 40 can realize high integration.

[0092]

As described above, according to the magnetoresistive effect element of the present invention, the reproduction fringe and Barkhausen noise are suppressed, the contact resistance is reduced, and the insulation failure is suppressed.
Good linear response and the like can be realized. Therefore, according to the magnetic head, the magnetic recording / reproducing head, and the magnetic storage device of the present invention using such a magnetoresistive effect element, good operating characteristics and the like can be obtained.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing the structure of an embodiment of a recording / reproducing separated magnetic head in which a first magnetoresistive effect element of the present invention is applied to a reproducing element section.

FIG. 2 is an enlarged cross-sectional view showing a magnetoresistive effect element portion which is a main portion of the recording / reproducing separated magnetic head shown in FIG.

FIG. 3 is a sectional view showing a first modification of the magnetoresistive effect element shown in FIG.

FIG. 4 is a plan view of a magnetoresistive effect element which is a main part of the recording / reproducing separated magnetic head shown in FIG.

5 is a sectional view showing a second modification of the magnetoresistive effect element shown in FIG.

6 is a cross-sectional view showing a third modification of the magnetoresistive effect element shown in FIG.

7 is a plan view showing a fourth modification of the magnetoresistive effect element shown in FIG. 2. FIG.

FIG. 8 is a sectional view showing a main part structure of an embodiment of a magnetoresistive head to which a second magnetoresistive element of the present invention is applied.

FIG. 9 is a diagram showing an example of the relationship between the exchange bias and the thickness of the magnetic film that gives the exchange bias in the antiferromagnetic film.

FIG. 10 is a cross-sectional view showing a main part structure of one embodiment of a magnetoresistive effect head to which a third magnetoresistive effect element of the present invention is applied.

FIG. 11 is a sectional view showing a main part structure of an embodiment of a magnetic memory device to which the magnetoresistive effect element of the present invention is applied.

FIG. 12 is a cross-sectional view showing a configuration example of a conventional magnetoresistive effect head.

[Explanation of symbols]

11 ... Board 12, 24 ... Magnetic shield layer 13, 23 ... Playback magnetic gap 14 ... Magnetoresistive film (GMR film) 15 ... Antiferromagnetic film 16 ... the first ferromagnetic film 17: Non-magnetic film 18 ... second ferromagnetic film 20: a pair of hard magnetic films 21 ... a pair of electrodes 22 ... GMR reproducing element 25 ... Shield type GMR head 29 ... Thin-film magnetic head 30 ... Recording magnetic gap 31 ... Magnetic pole 37 ... A pair of bias magnetic field applying films 40 ... MRAM 42 ... Spin valve GMR film 43 ... Bias magnetic field applying film 45 ... Writing electrode 46 ... A pair of readout electrodes

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kazuhiro Saito Kazuhiro Saito 72 Horikawa-cho, Kawasaki-shi, Kanagawa Prefecture, Kawasaki Plant, Toshiba Corporation (72) Masaji Sahashi 72 Horikawa-cho, Kawasaki-shi, Kanagawa Prefecture 72 Kawasaki, Toshiba Corporation In-house (56) Reference JP-A-8-204253 (JP, A) JP-A-9-50609 (JP, A) JP-A-6-223336 (JP, A) JP-A-9-16918 (JP, A) JP-A-9-282618 (JP, A) JP-A-4-358310 (JP, A) JP-A-10-65232 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G11B 5/39

Claims (12)

(57) [Claims] 1. A magnetoresistive effect film comprising: an antiferromagnetic film; a first ferromagnetic film provided on the antiferromagnetic film; and a first ferromagnetic film. An intermediate layer provided on the film and containing at least one of an oxide, a nitride, a carbide, and a fluoride of a material forming the first ferromagnetic film; A second ferromagnetic film whose direction is substantially fixed; a non-magnetic film provided on the second ferromagnetic film; and a non-magnetic film provided on the non-magnetic film, the direction of magnetization being the external magnetic field. And a third ferromagnetic film rotatable in accordance with the above. 2. The antiferromagnetic film comprises PtMn, IrMn,
PdPtMn, NiMn, RuMn, FeMn, RhM
The magnetoresistive effect element according to claim 1, wherein the magnetoresistive effect element is substantially composed of either n or CrMnPt. 3. A NiFeX (X is C is provided on the opposite side of the first ferromagnetic film and adjacent to the antiferromagnetic film.
r, Nb, Zr, Hf, W, Mo, V, Ti, Rh, I
and a layer substantially composed of at least one element selected from the group consisting of r, Cu, Au, Ag, Mn, Re and Ru). The magnetoresistive effect element according to. 4. The magnetoresistive element according to claim 1, wherein the intermediate layer has a thickness of 3 nm or less. 5. An antiferromagnetic film, a first ferromagnetic film, a second ferromagnetic film, which are provided adjacent to both ends of a magnetic field detecting portion of the magnetoresistive film, and which are at least the magnetoresistive film. The pair of hard magnetic films laminated on one of the films selected from the non-magnetic films, and the pair of electrodes for supplying a current to the magnetoresistive film, further comprising: The magnetoresistive effect element as described in any one of 4-4. 6. An antiferromagnetic film, a first ferromagnetic film, a second ferromagnetic film, which are provided adjacent to both ends of a magnetic field detecting portion of the magnetoresistive film and which are at least the magnetoresistive film. The pair of antiferromagnetic films stacked on one of the films selected from the non-magnetic films, and the pair of electrodes supplying a current to the magnetoresistive film, further comprising: The magnetoresistive effect element according to any one of 1 to 4. 7. A second antiferromagnetic film, which is provided adjacent to both ends of the third ferromagnetic film as viewed in the track width direction and exchange-coupled with the both ends of the third ferromagnetic film. The magnetoresistive effect element according to claim 1, wherein the magnetoresistive effect element is provided. 8. The antiferromagnetic film, the first ferromagnetic film, the second ferromagnetic film, the nonmagnetic film, and the third ferromagnetic film are sequentially stacked on a substrate. The magnetoresistive effect element according to any one of claims 1 to 7. 9. A magnetic head comprising the magnetoresistive effect element according to claim 1. Description: 10. A first reproducing magnetic gap layer provided below the magnetoresistive effect element, a first magnetic shield layer provided below the first reproducing magnetic gap layer, and the magnetic resistance. A second read magnetic gap layer provided on the effect element, and a second magnetic shield layer provided on the second read magnetic gap layer, further comprising: 9. The magnetic head according to item 9. 11. A magnetic head according to claim 10, a first magnetic pole shared with the second magnetic shield layer, a recording magnetic gap provided on the first magnetic pole, and the recording. A second magnetic pole provided above the magnetic gap; and a portion from the first magnetic shield layer to the second magnetic shield layer acts as a reproducing head, A magnetic recording / reproducing head characterized in that the portion up to the second magnetic pole acts as a recording head. 12. A magnetoresistive effect element according to claim 1, a write electrode for storing information in a magnetoresistive effect film of the magnetoresistive effect element, and the magnetoresistive effect element. And a read electrode for reproducing information stored in the magnetoresistive film, the magnetic storage device comprising: