JP2000173025A - Magnetoresistive effect element and magnetic head and magnetic disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetoresistive effect element for making satisfactory a switched connection force, and for obtaining a stable output in a long period. SOLUTION: This magnetoresistive effect element is provided with a switched connection film in which a base film 3, anti-ferromagnetic film 4, and ferromagnetic film 5 are laminated in this order, and the base film 3 is made of metal or alloy having a face centered cubic system crystal structure or a hexagonal closest crystal structure with an inter-most adjacent atom distance which is longer than the inter-most adjacent atom distance of the anti-ferromagnetic film 4. Thus, a magnetoresistive effect element for obtaining a stable output in a long period can 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 an exchange coupling film utilizing exchange coupling between an antiferromagnetic film and a ferromagnetic film, a magnetic head using the magnetoresistive element, and a magnetic head. And a magnetic disk device using the magnetic head.

[0002]

2. Description of the Related Art As a reproducing head for high-density magnetic recording, a magnetic head using a magnetoresistive element has been studied. At present, a thin film of 80 at% Ni-20 at% Fe (commonly called permalloy) alloy is used as a magnetoresistive element material. In recent years, as a substitute material, an artificial lattice film such as (Co / Cu) n or the like, which exhibits a giant magnetoresistance effect, and a spin valve film have been attracting attention.

Since the magnetoresistive film made of permalloy has magnetic domains, Barkhausen noise caused by the magnetic domains has been a serious problem in practical use, and various methods for making the magnetoresistive film into single magnetic domains have been studied. One of the methods is to control the magnetic domain of the magnetoresistive film in a specific direction by using exchange coupling between the magnetoresistive film, which is a ferromagnetic material, and the antiferromagnetic film. The antiferromagnetic material here is γ-
FeMn alloys have been widely known (for example,
U.S. Pat. No. 4,103,315 and U.S. Pat.
014147). This magnetoresistance effect is called anisotropic magnetoresistance effect.

Further, in recent years, a technique that utilizes exchange coupling between an antiferromagnetic film and a ferromagnetic film in order to pin the magnetization of the magnetic film of the spin valve film has become widespread. Also for this purpose, a γ-FeMn alloy is often used as an antiferromagnetic film.

However, the γ-FeMn alloy has a problem of corrosion resistance, particularly corrosion to water, and is exchanged with a magnetoresistive film with the passage of time due to corrosion in a processing process as a magnetoresistive element and corrosion due to atmospheric moisture. There is a problem that the bonding force is deteriorated.

In recent years, a Pentium processor mounted on a machine with a higher processing capacity has a very large amount of heat, and the temperature rises to about 150 ° C. during operation even in an HDD, 150
Exchange coupling force of 200 Oe or more at ℃ is also required from the viewpoint of reliability. In order to obtain an exchange coupling force of 200 Oe or more at 150 ° C., it is desirable not only that the exchange coupling force at room temperature be high, but also that the temperature characteristics of the exchange coupling force be good. Furthermore, the blocking temperature, which is the temperature at which the exchange coupling between the ferromagnetic film and the antiferromagnetic film is cut off, must be as high as possible.

However, in the case of a γ-FeMn alloy, the blocking temperature is 170 ° C. or lower, and the temperature characteristics of the exchange coupling force are very poor. The problem of lack exists.

An example using oxide-based NiO or the like is disclosed in US Pat. No. 4,103,315. Further, US Pat. No. 5,315,468 discloses that when an antiferromagnetic film is formed of a θ-Mn alloy such as a NiMn alloy having a face-centered tetragonal crystal structure, the antiferromagnetic film and the ferromagnetic film can be formed even at a high temperature range. It is shown that the exchange coupling force does not decrease.

Furthermore, the present applicant has proposed an IrMn-based antiferromagnetic film having a face-centered cubic structure having excellent characteristics. As an antiferromagnetic film having the same crystal structure, an example using another γ-Mn alloy such as MnPt and MnRh alloy is reported in US Pat. No. 5,315,468.

However, since these antiferromagnetic films are Mn alloys in which it is difficult to form a high-density target,
It is difficult to control the film quality. When an antiferromagnetic film is laminated on the ferromagnetic film or the spin valve film,
Since the ferromagnetic film or the spin-valve film serves as a base film for the antiferromagnetic film, the antiferromagnetic film grows crystal to obtain good exchange coupling characteristics. In the case where is located under the ferromagnetic film, there is a problem in selecting the underlayer as the crystal growth promoting layer.

[0011]

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and the antiferromagnetic film has a sufficient exchange coupling force with the ferromagnetic film, A magnetoresistive element having a low interlayer coupling (indirect interlayer coupling magnetic field) between the film and another ferromagnetic film can provide a sufficiently low resistance change rate and a stable output over a long period of time. An object of the present invention is to provide a magnetoresistive element that can be used, a magnetic head and a magnetic disk device using the magnetoresistive element, and a manufacturing method that can efficiently supply the magnetoresistive element.

[0012]

According to the present invention, there is provided an exchange coupling film comprising a base film, an antiferromagnetic film, and a ferromagnetic film laminated in this order. Having a face-centered cubic crystal structure or a hexagonal close-packed crystal structure having a closest interatomic distance longer than the closest interatomic distance of the antiferromagnetic film. A characteristic magnetoresistive element is provided.

According to a fourth aspect of the present invention, there is provided an exchange coupling film in which a base film, an antiferromagnetic film, and a ferromagnetic film are laminated in this order, and the base film is made of Ru, Rh, Ir, Cr, Re,
A single film, a laminated film using at least one of Tc and Os,
Alternatively, there is provided a magnetoresistive element characterized by being an alloy film.

According to a twenty-third aspect of the present invention, there is provided a lower magnetic shield layer, a lower reproducing magnetic gap formed on the lower magnetic shield layer, and the above-mentioned invention formed on the lower reproducing magnetic gap. A magnetic head, comprising: a magnetoresistive effect element; an upper reproducing magnetic gap formed on the magnetoresistive element; and an upper magnetic shield layer formed on the upper reproducing magnetic gap. A magnetic disk device using the magnetic head is provided.

[0015] According to a twenty-fifth aspect of the present invention, a first aspect is provided.
22. A method of manufacturing an exchange-coupling film, characterized in that the antiferromagnetic film is formed using an alloy target having an oxygen content of 0.5% by weight or less when manufacturing the magnetoresistance effect element according to any one of the above-mentioned items.

The invention of claim 1 of the present invention is based on the following finding. That is, by selecting, as a base film of the antiferromagnetic film, a film having a closest interatomic distance larger than the closest interatomic distance of the antiferromagnetic film, the base film is formed of a crystal of the antiferromagnetic film. It functions as a growth promoting layer, and as a result, when the thickness of the antiferromagnetic material film is small, it has sufficient exchange coupling force, high blocking temperature, and if the crystallinity of the antiferromagnetic material film becomes good. The characteristics of the magnetization free layer laminated on the upper layer are also improved, high resistance change rate, high resistance change rate, heat resistance, high resistance change are obtained, and furthermore, deterioration in the process due to good crystallinity is suppressed. Therefore, the output can be improved and a more stable output can be obtained for a long period of time.

In the invention of claim 1 of the present invention, it is preferable that the underlayer film in contact with the antiferromagnetic film has the following form. 1-1 The base film is made of Tc, Re, Ru, Os, R
h, Ir, Pd, Pt, Ag, Au, Zn, Cd, A
a single film, a laminated film, or an alloy film using at least one selected from l, Tl, and Pb; -2 base film is Tc, Re, Ru, Os, Rh, Ir,
Pd, Pt, Ag, Au, Zn, Cd, Al, Tl, P
b, a first layer that is a single film, a laminated film, or an alloy film using at least one selected from the group consisting of Ti, Ta, Hf, and Z
A single film, a stacked film, or a stacked film with a second layer which is an alloy film using at least one selected from r, Nb, and V, and the first layer is in contact with the antiferromagnetic film.

According to the invention of claim 4 of the present invention, Ru, Rh, Ir, Cr, R
By selecting at least one selected from the group consisting of e, Tc, and Os, the layer functions as a crystal growth promoting layer of the antiferromagnetic film, and as a result, has a sufficient exchange coupling force in a thin antiferromagnetic film. If the antiferromagnetic material film has good crystallinity, the characteristics of the magnetization free layer laminated thereon can be improved, and a low interlayer cup can be used for bias point design. Since the ring is obtained and the crystallinity becomes good, the deterioration due to the process is suppressed, so that the output can be improved and a stable output can be obtained for a long period of time. In the invention according to claim 4 of the present invention, the following forms are desirable for the underlayer film in contact with the antiferromagnetic material. (1) The base film further includes a single film, a laminated film, or an alloy film using at least one selected from Ti, Ta, Hf, Zr, Nb, and V. -2 The base film is made of Pd, Pt, Ag, Au, Zn, Cd,
A single film, a laminated film, or an alloy film using at least one selected from Al, Tl, and Pb is further provided. In this way, the layer functions as a crystal growth promoting layer of the antiferromagnetic film, and as a result, a sufficient exchange coupling force and a high blocking temperature can be obtained where the antiferromagnetic film is thin. In a so-called spin valve, dual spin valve, or non-coupled artificial lattice in which a magnetization free layer is provided on the upper side of the exchange-coupling film, if the crystallinity of the antiferromagnetic film is improved, the antiferromagnetic film is further laminated thereon. The characteristics of the magnetization free layer are also improved, and a high resistance change rate, a high resistance change rate heat resistance, a high resistance change, and a low interlayer coupling that is advantageous for bias point design can be obtained. At the same time, since the crystallinity is improved, deterioration due to the process is suppressed, so that an improved output and a more stable output can be obtained for a long period of time. -3 base film is made of Pd, Pt, Ag, Au, Zn, Cd,
A single film, a laminated film, or an alloy film using at least one selected from Al, Tl, and Pb, and Ti, Ta, Hf, Z
a single film, a stacked film, or an alloy film using at least one selected from r, Nb, and V;

Further, in each of the first and second aspects of the present invention, the antiferromagnetic film preferably has the following form. (1) At least a part of the antiferromagnetic film has a face-centered cubic crystal structure. (1) -1 The antiferromagnetic film is made of R _x Mn _100-x (R is I
r, Rh, Pt, Ru, Au, Ag, Co, Pd, G
e, at least one element selected from Re, Ni, and Cu, and 5 ≦ x ≦ 40). (1) -2 antiferromagnetic material film _{(R x Mn 1-x)} 100-y F
e _y (R is Ir, Rh, Pt, Ru, Au, Ag, C
o, at least one element selected from Pd, Ge, Re, Ni, and Cu (5 ≦ x ≦ 40, 0 <y <30). If the value of x in (1) -1 and (1) -2 is less than 5 or greater than 40, the exchange coupling force is undesirably reduced. The addition of Fe in (1) -2 has the effect of increasing the exchange coupling force, but if the value of y is 30 or more, the corrosion resistance is greatly reduced, which is not preferable. (1) -3 The antiferromagnetic film is made of Ta, Hf, Nb, Si,
Al, W, Zr, Ga, Be, In, Sn, V, Mo,
At least one selected from Os, Cd, Zn, N, Cr, and Ni. By doing so, the corrosion resistance can be improved. The antiferromagnetic film composed of R and Mn has much improved corrosion resistance as compared with the conventionally used FeMn-based antiferromagnetic film, but the corrosion resistance can be further improved by adding these elements. . (2) At least a part of the antiferromagnetic film has a face-centered tetragonal crystal structure or a body-centered cubic structure. (2) -1 The antiferromagnetic film is made of R _x Mn _100-x (R is P
t, at least one element selected from Ni, Pd, and Cr, 40 ≦ x ≦ 60). (2) -2 antiferromagnetic material film _{(R x Mn 1-x)} 100-y F
e _y (R is at least one element selected from Pt, Ni, Pd, and Cr, 40 ≦ x ≦ 60, 0 <y <30). If the value of x in (2) -1 and (2) -2 is less than 40 or greater than 60, fct or bcc-based crystal structure is less likely to be formed, and exchange coupling force is undesirably reduced. As in the case of the fcc crystal structure, the addition of Fe increases the exchange coupling force.
If it is 0 or more, the corrosion resistance is greatly reduced, which is not preferable. (2) -3 The antiferromagnetic film is made of Ta, Hf, Nb, Si,
Al, W, Zr, Ga, Be, In, Sn, V, Mo,
Os, Cd, Zn, N, Cr, Au, Ag, Co, R
e, containing at least one selected from Ge.
The antiferromagnetic material film composed of R and Mn has been used in the conventional F
Although the corrosion resistance is much improved as compared with the eMn-based antiferromagnetic film, the corrosion resistance can be further improved by adding these elements. (1) -3, (2) -3
In (2), the addition amount for improving the corrosion resistance is preferably 50 at% or less, more preferably 30 at% or less, and if it is more than 50 at%, a sufficient exchange coupling force cannot be obtained. (3) The half width of the XRD rockin curve of the antiferromagnetic film is within 15 °. By doing so, the crystallinity is improved and the blocking temperature is improved. Further, among the direct resistance effect films, the above-described spin valve, dual spin valve,
If the magnetization free layer of the artificial lattice that responds to the external magnetic field is similarly oriented, it becomes easy to become soft magnetic. (4) The <111> axis of the antiferromagnetic film is oriented perpendicular to the film surface. By doing so, the crystallinity is improved and the blocking temperature is improved. Further, in the direct resistance effect film, if the magnetization free layer sensitive to the external magnetic field is similarly oriented, it becomes easy to become soft magnetic similarly to (3). (5) Matching of the atomic spacing at the interface between the antiferromagnetic film and the first layer or the underlayer is -6% or more and 15% or less. Tables 1 and 2 show the crystal structures, lattice constants, and (11) of materials that can be used as the antiferromagnetic film and the underlayer.
1) The distance between the nearest atoms in the plane is shown.

[0020]

[Table 1]

[0021]

[Table 2]

Comparing the closest interatomic distances in Tables 1 and 2, when the antiferromagnetic film is IrMn, Rh and Zn, which are shorter than the closest interatomic distance of IrMn, are excluded. It can be seen that materials other than Ru, Rh and Zn in the case of PtMn, and all materials in Table 2 can be used as the interface layer in the case of RhRuMn. Also, Pb
With regard to (3), lattice matching is three times the closest interatomic distance of Pb and four times the closest interatomic distance of the antiferromagnetic film. The crystal structure of PtMn is face-centered tetragonal (fct)
Although it has a structure, as-depo. Has a face-centered cubic (fcc) structure, it is conceivable that a part of the crystal structure after heat treatment has an fcc structure.

In order to select a material having at least a part having an fcc crystal structure as the antiferromagnetic film,
A material having an fcc-based crystal structure or a hexagonal close-packed crystal (hcp) structure is selected as the base film in consideration of the consistency of the crystal structure. Further, the CrMn-based antiferromagnetic film has a body-centered cubic structure, but is a material in which the (110) plane and the like easily grow epitaxially on the first layer of the fcc-based crystal structure.

As for Au among the materials shown in Table 2, the rate of change in resistance may be increased by about 1% and the resistance change may be increased by about 0.2 ohm as compared with the case of using a single-layer film of Cu alone. It was found by the study of the present inventors.

In order to obtain a high resistance change rate as a laminated film of the base film or an alloy film, Au, Ta / Au, Au / Pt,
Ag / Au, Ag / Pd / Au, Ta / Au / Ag, T
It can be used like i / AuAg. Also, in the case of an alloy film or a multilayer film containing Cu such as AuCu or Cu / Au, in addition to Cu, for example, Au which has a closest interatomic distance larger than that of the antiferromagnetic film is contained. As long as the conditions for epitaxial growth and alloying are met, the distance between the nearest atoms of the antiferromagnetic film is longer than that of the antiferromagnetic film, and Cu can be used as a base film.

To obtain low interlayer coupling, Ru, Ta / Ru, Rh / Ru, Cr / R
u, Ru / Rh / Ru, Ta / Rh / Ru, Ti / Rh
Used like Ru. Furthermore, if it is desired to achieve both a high resistance change rate and a low interlayer coupling, Ru / A
u, Ta / Ru / Au, Rh / Ag, Au / Ru, Ta
/ Pd / Ru, Ti / RuRh / Au, etc.

In manufacturing the base film, the base film may be formed using an alloy target, or a laminated film of a dissimilar single metal may be formed and subjected to a heat treatment to cause diffusion and alloying. . In addition, film forming speed, gas pressure, bias film forming,
Since the atomic spacing changes depending on the film forming conditions such as a film forming apparatus,
Even if the same element is used, the atomic spacing with the antiferromagnetic film may be different. The atomic spacing may also change depending on the form of lamination with a different metal.

The thickness of the underlayer may be any range as long as the sense current is not shunted and the rate of change in resistance is not reduced.
Preferably it is 10 nm or less. Since the noble metal material used for the base film has a low resistance value, if it is more than 10 nm, a sense current is shunted, and the resistance change rate is reduced. However, if the thickness is too small, the flatness is impaired.

As described above, the antiferromagnetic material film has at least partly an fcc-based crystal structure, an fct-based crystal structure,
A material having a bcc crystal structure is used. These crystal structures include structures in which the lattice constants a, b, and c are not the same and are distorted by being dragged due to epitaxial growth with the underlying film.

Here, a part of the antiferromagnetic film having the fcc structure may be a regular phase. Since the antiferromagnetic material as described above has a high Neel point, the blocking temperature is high, the reliability is improved, and at the same time, the exchange coupling is increased. for that reason,
The presence of an ordered phase is preferred. Although the antiferromagnetic material film having the fct structure does not show exchange coupling in the fcc structure in as-depo, the heat treatment is performed in a magnetic field of 230 ° C. or more to obtain the fct structure.
Transforms to ct structure and shows good exchange coupling.

In producing the antiferromagnetic film, the film is formed by using an alloy target having an oxygen content of 0.5% by weight or less, which is composed of the antiferromagnetic film, and is incorporated into the film. The oxygen concentration is reduced, and the film quality can be formed into a thin film with good controllability.

The thickness of the antiferromagnetic film is 15 in the fcc structure.
nm or less, more preferably 10 nm or less;
In the fct structure and the bcc structure, the thickness is 30 nm or less, and more preferably, 20 nm or less. When the film thickness is increased, a shunt of the sense current is caused, and the resistance change rate is reduced.

The matching of the atomic spacing between the antiferromagnetic film and the interface layer (difference in the distance between nearest neighbor atoms) is -6% or more from the viewpoint of obtaining sufficient exchange coupling characteristics without generating large crystal distortion. , 15% or less.

The following forms are preferable as the ferromagnetic film used for the exchange coupling film in the present invention. (1) Co or Co alloy is used for the ferromagnetic film. (2) The ferromagnetic film is a ferromagnetic film having a face-centered cubic structure made of at least one of Fe, Co, and Ni. The free layer structure of the spin valve film is CoFe / NiFe /
CZN or CoFe / NiFe laminate (interface is CoFe
Or CoFe, NiFe
It may be single.

To these ferromagnetic metal alloys, third and fourth elements such as Au, Ir, Pd and Pt are added for the purpose of improving magnetic properties and lattice matching with the RMn-based antiferromagnetic film. Is preferred.

Of the above-mentioned ferromagnetic films, Co is preferably used.
This is a ferromagnetic film. When a magnetoresistive element is used, the rate of change in resistance is larger in a Co-based material than in a NiFe-based device. Further, in the case of a magnetoresistive effect element, since Ni in the NiFe-based ferromagnetic material and Cu used for the nonmagnetic layer are all solid solution type, they are diffused by a temperature rise of about 200 ° C. during the magnetic head fabrication process. Occurs, and the value of the resistance change rate is degraded.

On the other hand, Co in the Co-based ferromagnetic film is insoluble in Cu and in a solid solution.
Even when the temperature rises by ° C., the original resistance change rate can be obtained by performing the heat treatment in a magnetic field.

A system in which a layer of a Co-based ferromagnetic film is at the interface with Cu, or a ferromagnetic material in which Fe is placed at the interface between a Co or Co alloy ferromagnetic film and an antiferromagnetic film to control the Fe concentration A film may be used. An increase in Fe concentration sometimes causes an increase in exchange coupling force. Specifically, when the Fe concentration becomes about 10%, the exchange coupling force increases about 1.5 times.

The ferromagnetic film may be a microcrystalline or amorphous film. Further, at least a part of the ferromagnetic film and the antiferromagnetic film may be laminated and exchange-coupled.

The exchange coupling film of the present invention is formed on, for example, a substrate by using a known film forming method such as an evaporation method, a sputtering method, and an MBE method. At this time, in order to impart unidirectional anisotropy to the coupling between the antiferromagnetic film and the ferromagnetic film, the film is formed in a magnetic field,
Heat treatment may be performed. Further, the heat treatment is also effective to make the ordered phase appear.

In the above description, the base film has been described as the base film of the antiferromagnetic film. However, in each of the layers of the spin valve film structure, the lower layer of a certain layer is considered to be the base film. It is also important to select a composition in consideration of lattice matching with each layer.

The substrate is not particularly limited, such as an amorphous substrate such as glass and resin, a single crystal substrate such as Si, MgO, Al ₂ O ₃ , altic, and various ferrites, an oriented substrate, and a sintered substrate.

Furthermore, in the exchange coupling film of the present invention, if at least an electrode for passing a current through the ferromagnetic film is formed of, for example, Cu, Ag, Au, Al, or an alloy thereof, the present invention Can easily be obtained. Here, the electrode may be in a form of directly contacting the ferromagnetic film or a form via an antiferromagnetic film.

The following example is desirable for the form of the magnetoresistance effect element. (1) A first magnetization fixed layer using a ferromagnetic film is disposed above an antiferromagnetic film, and a magnetization free layer using a ferromagnetic film is disposed above the first magnetization fixed layer. thing. (2) A second magnetization pinned layer using an exchange coupling film is further disposed on the magnetization free layer. (3) The ferromagnetic film has a laminated structure of a first ferromagnetic film / non-magnetic film / second ferromagnetic film.

The recording / reproducing integrated magnetic head can be realized by taking the following form. (1) A read head using the magnetic head according to claim 22, a lower magnetic pole shared by an upper magnetic shield layer of the read head, a recording magnetic gap formed on the lower magnetic pole, and a recording magnetic gap. And an upper magnetic pole formed thereon.

Using such a magnetic head, it is possible to realize a magnetic disk device for reproducing magnetic information recorded on a magnetic disk. As described above, the magnetoresistance effect element of the present invention is applied to various devices using the magnetoresistance effect element such as a magnetic field detection sensor, a magnetic head for reproduction / integrated recording / reproducing magnetic head, and a magnetic memory as described above. it can.

[0047]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 1 is a schematic sectional view of a spin valve film as an exchange coupling film according to a first embodiment of the present invention.

In the figure, reference numeral 1 denotes Al ₂ O ₃ .TiC, Si
An alumina film having a thickness of about 100 nm is formed as a gap film 2 on the substrate 1, and a base film 3 is formed on the gap film 2. Base film 3
Is, for example, an Ag film 3-3 (about 1 nm thick) / Au film 3
-2 (about 1 nm thick) / Ta film 3-1 (about 5 nm thick)
Has a laminated structure. Here, Ta was also used,
You don't have to. On the base film 3, an antiferromagnetic film 4 of about 5 to 10 nm in thickness using IrMn or the like, a magnetization pinned layer 5 of about 2 to 3 nm in thickness as a ferromagnetic film using CoFe, and Cu are used. A non-magnetic layer 6 having a thickness of about 2 to 3 nm,
A magnetization free layer 7 having a thickness of about 2 to 5 nm as a ferromagnetic film using CoFe and a protective film 9 having a thickness of about 5 nm using Ta are stacked in this order.

Here, the base film 3 may be a single-layer film, a two-layer film, or a laminated structure of three or more layers. The base film may be not only a laminated structure of a single metal but also a laminated structure of an alloy film or a single film of an alloy film. In addition, although the base films of -1 and -2 are used here,
Underlayers of -1, -2 and -3 are also used.

The structure of the magnetization free layer 7 is NiFe / C
A laminate of oFe (including a structure in which the interface is CoFe) may be used. The protective film 8 also functions as a lower strain control layer. As the protective film 8, Ta, Ti, Au, Ag, Pd,
Any metal film such as Cu or Ru may be used. It may be a single layered film or an alloy film.

By forming the protective film 8 in consideration of lattice matching with the magnetization free layer 7 which is the underlying film of the protective film 8 and compatibility with the underlying film, the protective film 8 exerts its power as a cap layer.

The composition of each layer may be changed in consideration of lattice matching with the underlying layer of the layer. For example, the magnetization fixed layer 5 may have a Fe-rich composition, or a single Fe layer may be interposed between the antiferromagnetic film 4 and the magnetization fixed layer 5.

The above description also applies to the following embodiments. According to this embodiment, the antiferromagnetic film can be used thinly, the exchange coupling force between the antiferromagnetic film and the ferromagnetic film is large, the high resistance change rate, and the low interlayer coupling are achieved. Since it is obtained and has excellent heat resistance, a stable output can be obtained over a long period of time.

(Second Embodiment) FIG. 2 shows a second embodiment of the present invention.
1 is a schematic cross-sectional view of a spin valve film as an exchange coupling film according to an embodiment. This embodiment is different from the first embodiment in that a magnetization fixed layer 5-
1 and 5-2 are formed via the nonmagnetic layers 6-1 and 6-2, respectively, and the antiferromagnetic layer 4-2 is also formed on the upper pinned layer 5-2. is there. Here, as an example of the base film 3, an Au film 3-2 (about 2 nm thick) / Ta film 3
-1 (about 5 nm thick) is used.

An interface layer considering lattice matching may be inserted under the antiferromagnetic film 4-2, or the magnetization fixed layer 5 may be inserted.
The composition of -2 may be changed. Antiferromagnetic film 4-1 and 4-
2 may be the same antiferromagnetic film, or different antiferromagnetic films.

In the case of the present embodiment, in addition to the effect obtained by the first embodiment, a high resistance change rate can be obtained by having two magnetization fixed layers. (Third Embodiment) FIG. 3 is a schematic sectional view of a spin valve film as an exchange coupling film according to a third embodiment of the present invention. This embodiment is different from the first embodiment in that the magnetization fixed layer 5 is formed of a CoFe film 5-3 (having a thickness of about 1.5 to 1.5 mm).
3 nm) / Ru film 5-2 (thickness: about 0.7 to 1.2 nm)
/ CoFe film 5-1 (having a thickness of about 1.5 to 3 nm). Here, an Ag film 3-3 (about 2 nm in thickness) / Ta film 3-1 (about 5 nm in thickness) was used as an example of the base film 3.

The laminated structure of the magnetization fixed layer 5 is CoFe / M /
It has a three-layer structure of CoFe (Synthetic AntiFerro, hereinafter referred to as SyAF). Co
Instead of Fe, Co, Co alloy, NiFe alloy, N
i or Fe may be used. M is Ru, Cr, A
g, Cu, V, Re, W, Rh, Ir, Nb, Mo, T
a and the like.

This SyAF is characterized in that both ferromagnetic films via M have antiferromagnetic coupling. Here, the CoFe film 5-1 laminated with the antiferromagnetic film 4 does not contribute to the magnetoresistance effect.

By changing the MsT of both ferromagnetic films of SyAF, it is useful for bias point design and the like. Ms
To change T, there is a means of changing the thickness of T, but Ms may be changed by changing the composition of both ferromagnetic films. For example, C
o (AF side) / M / Co ₉₀ Fe ₁₀ or Co ₈₀ Fe
Various combinations such as ₂₀ (AF side) / M / Co ₉₀ Fe ₁₀ are possible.

In the case of the present embodiment, in addition to the effects obtained by the first embodiment, the leakage magnetic field from the magnetization fixed layer can be reduced because the magnetization fixed layer is made of SyAF.
As a result, it is possible to obtain such effects that the thickness of the magnetization free layer can be designed thin, the bias point can be designed, and the heat resistance of the resistance change rate is improved.

(Fourth Embodiment) FIG. 4 shows a third embodiment of the present invention.
1 is a schematic cross-sectional view of a spin valve film as an exchange coupling film according to an embodiment. This embodiment has a structure in which the third embodiment is combined with the second embodiment.
Here, as an example of the base film 3, an Al film 3-4 (having a thickness of about 2
nm) / Ta film 3-1 (thickness: about 5 nm).

In the case of the present embodiment, M also serves as an orientation changing film. Specifically, from the bottom of the laminated structure, CoFe
The film 5-2-1 is oriented in the (111) plane, and the Ru film 5-2-2 as M controls the orientation plane to control the Ru film 5-2-2.
It is possible to have a (110) plane orientation above the CoFe film 5-2-3 on the second substrate. At this time, the material system of M is determined from lattice matching, orientation, and the like. In this case, the orientation of M may be changed by itself, or the orientation plane may be changed by changing the top of M to a ferromagnetic film which is easily oriented other than the (111) orientation.

In the case of the present embodiment, an effect obtained by combining the first, second, and third embodiments can be obtained. (Fifth Embodiment) By providing an electrode on the spin valve film of the above-described embodiment, the magnetoresistive effect element is further stacked with an upper and lower magnetic shield layer, an upper and lower reproducing magnetic gap, and the like. The head is obtained. Also, a recording / reproducing integrated magnetic head in which a recording section is laminated on a reproducing section can be manufactured.

FIG. 5 shows a recording according to a fifth embodiment of the present invention in which the exchange coupling film of the present invention is used for a magnetoresistive element and the magnetoresistive element is applied to a reproducing magnetic head. 1 shows a cross-sectional view of a reproduction-integrated magnetic head.

In the drawing, reference numeral 31 denotes a substrate using Al ₂ O ₃ .TiC or the like. An insulating layer 32 using Al ₂ O ₃ or the like, and a lower magnetic shield layer 3 using a soft magnetic material are formed on the substrate 31.
3. A lower reproducing magnetic gap 34 using a nonmagnetic insulating film such as Al ₂ O ₃ is laminated in this order.

The magnetoresistive element 9 is formed on the lower reproducing magnetic gap 34. This magnetoresistive effect element 9
Is a spin valve film 10 as an exchange coupling film of the present invention formed on the lower reproducing magnetic gap 34 and a bias magnetic field applied to the spin valve film 10 formed adjacent to both ends of the spin valve film 10. And a pair of electrodes 11 formed on the hard magnetic film 35 using a CoPt alloy or the like.

An upper magnetic reproducing gap 36 using a nonmagnetic insulating film such as Al ₂ O ₃ is formed on the magnetoresistive effect element 9, and an upper magnetic shield layer 37 is further formed thereon. A shield type magnetic head 38 functioning as a reproducing head is configured.

On the magnetic head 38, a recording head using an inductive type thin film magnetic head 39 is formed. The upper magnetic shield layer 37 also serves as a lower recording magnetic pole of the induction type thin film magnetic head 39. On the upper magnetic shield layer and the lower recording magnetic pole 37, a recording magnetic gap 40 using a nonmagnetic insulating film such as Al2 O3 is provided. Upper recording magnetic poles 41 patterned in a shape are stacked in this order.

The upper recording magnetic pole 41 is formed by burying a trench 44 in the insulating layer 43. The recording / reproducing magnetic head 4 is formed by the shield type magnetic head 38 and the induction type thin film magnetic head 39.
2 are configured.

In the magnetic head of this embodiment, since the magneto-resistance effect element according to the present invention is used, the exchange coupling force is good, and a stable output can be obtained for a long period of time.

Sixth Embodiment A recording / reproducing integrated magnetic head as shown in the fifth embodiment is incorporated in a head slider, and this head slider is, for example, a magnetic disk as shown in FIG. It is mounted on a magnetic recording device such as a device. FIG. 6 shows a schematic structure of a magnetic disk drive 50 using a rotary actuator according to a sixth embodiment of the present invention.

In the figure, a magnetic disk 51 is mounted on a spindle 52 and is rotated by a motor (not shown) which responds to a control signal from a drive control source (not shown). A head slider 53 for recording and reproducing information while the magnetic disk 51 is floating is attached to the tip of a thin-film suspension 54. Here, the head slider 53
Has a recording / reproducing integrated magnetic head as shown in the fifth embodiment, for example.

When the magnetic disk 51 rotates, the medium facing surface (ABS) of the head slider 53 is moved to the magnetic disk 51.
From the surface with a predetermined floating amount. The suspension 54 is connected to one end of an actuator arm 55 having a bobbin for holding a drive coil (not shown). At the other end of the actuator arm 55, a voice coil motor 56, which is a type of linear motor, is provided. The voice coil motor 56 includes a drive coil (not shown) wound around a bobbin portion of the actuator arm 55, and a magnetic circuit including a permanent magnet and an opposing yoke, which are opposed to each other so as to sandwich the coil.

The actuator arm 55 has a fixed shaft 57
Are held by ball bearings (not shown) provided at two locations above and below, and can be freely rotated and slid by the voice coil motor 56.

[0075]

Embodiments of the present invention will be described below. (Example 1) Using a DC magnetron sputtering apparatus,
Various combinations of the antiferromagnetic film and the underlayer of the first embodiment were prepared, and the exchange coupling magnetic field (Hua), the blocking temperature (Tb), the rate of change in resistance (MR), and the coercive force ( Hc (free)) was measured. 270 ° C, 1Hour for fcc system, 270 ° C, 10hour for fct system
Hour has been heat treated. The magnetization pinned layer is CoFe
The thickness was 2.5 nm, and the magnetization free layer was CoFe 3 nm.
As a comparative example, an example in which only Ta alone was used for the base film was manufactured, and the same measurement as in the example was performed.

Table 3 shows the results. In the table, underlayer1,2,
Reference numerals 3 and 4 denote structures of the base film of the antiferromagnetic film, and 1,2,3 and 4 are laminated in this order from the bottom. That is, underlayer
The underlayer provided with 4 is that the underlayer 4 is in contact with the antiferromagnetic film, the underlayer 3 is in the outermost surface, the underlayer 3 is in contact with the antiferromagnetic film, and the underlayer 2 is the outermost film.
underlayer3 contacts the antiferromagnetic film. Underlayer
The underlayer having only 1 has the underlayer 1 in contact with the antiferromagnetic film.

[0077]

[Table 3]

As can be seen from Table 3, according to the exchange coupling film of the present invention, a large value of the exchange coupling magnetic field at room temperature was obtained, and as a result, even at a temperature characteristic of 150 ° C., 200 Oe.
A value sufficiently higher than the degree is obtained, and the blocking temperature is 250 ° C. or more, which is a practically sufficient value. Stable output can be obtained over a long period of time because of sufficient heat resistance.

(Example 2) Using a DC magnetron sputtering apparatus, the antiferromagnetic film of the third embodiment
n, Ta (5 nm) / Au (2 nm), Ta (5 nm)
nm) / Ru (2 nm), Ta (5 nm) / Ru (1 nm) /
A combination of Au (1 nm) was prepared. The dependence of the resistance change rate and the dependency of the interlayer coupling on the thickness of the IrMn film with respect to these base films were examined. The composition is
IrMn / CoFe (2nm) / Ru (0.9nm) / Co
Fe (2nm) / Cu (2nm) / CoFe (2nm) / Cu
(1.5 nm) / Ta. Cu is used for the cap layer. The results are shown in FIGS. FIG. 7 shows the relationship between the thickness d (nm) of IrMn and the interlayer coupling (Hin) in each base film. FIG. 8 shows the relationship between the thickness d (nm) of IrMn and the resistance change rate in each base film. As can be seen from the figure, a large resistance change rate was obtained on the Ta / Au underlayer, and Ta / Ru was obtained.
A low interlayer coupling is obtained on the base. Further, with the Ta / Ru / Au underlayer, a large resistance change rate and a low interlayer coupling are obtained. ADVANTAGE OF THE INVENTION According to the exchange coupling film of this invention, realization of a low antiferromagnetic material film thickness, a large resistance change rate, and a low interlayer coupling are obtained, and a stable output can be obtained over a long period of time.

[0080]

As described in detail above, the magnetoresistive effect element, the method of manufacturing the same, and the magnetic head of the present invention are provided with an exchange coupling film having a good exchange coupling force and can obtain a stable output for a long period of time. And its industrial value is great.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of an exchange coupling film according to a first embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view of an exchange coupling film according to a second embodiment of the present invention.

FIG. 3 is a schematic cross-sectional view of an exchange coupling film according to a third embodiment of the present invention.

FIG. 4 is a schematic cross-sectional view of an exchange coupling film according to a fourth embodiment of the present invention.

FIG. 5 is a sectional view of a recording / reproducing integrated magnetic head according to a fifth embodiment of the present invention.

FIG. 6 is a schematic diagram of a magnetic recording device according to a sixth embodiment of the present invention.

FIG. 7 is a characteristic diagram according to the second embodiment of the present invention.

FIG. 8 is a characteristic diagram according to the second embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Substrate, 2 ... Gap film, 3 ... Under film, 3-1 ... Second layer, 2-2, 3, 4 ... First layer, 4 ... Antiferromagnetic film, 5 ...
Magnetization fixed layer, 6: non-magnetic layer, 7: magnetization free layer, 8: protective film

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazuhiro Saito 72 Horikawa-cho, Saiwai-ku, Kawasaki-shi, Kanagawa Pref. In-house Toshiba Kawasaki Office (72) Inventor Hitoshi Iwasaki 72 Horikawa-cho, Saiwai-ku, Kawasaki-shi, Kanagawa Prefecture F-term in Toshiba Corporation Kawasaki Office (Reference)

Claims (26)

[Claims] An exchange coupling film in which a base film, an antiferromagnetic film, and a ferromagnetic film are stacked in this order, wherein the base film is longer than a closest interatomic distance of the antiferromagnetic film. A magnetoresistive element comprising a metal or an alloy having a face-centered cubic crystal structure or a hexagonal close-packed crystal structure having a closest interatomic distance. 2. The method according to claim 1, wherein the underlayer is made of Tc, Re, Ru, Os, R
h, Ir, Pd, Pt, Ag, Au, Zn, Cd, A
2. The magnetoresistance effect element according to claim 1, wherein the element is a single film, a laminated film, or an alloy film using at least one selected from l, Tl, and Pb. 3. The underlayer has a first layer in contact with the antiferromagnetic film and a second layer in contact with the first layer, and the first layer is made of Tc, Re, Ru, Os, Rh. , Ir, Pd, P
t, Ag, Au, Zn, Cd, Al, Tl, Pb, a single film, a laminated film, or an alloy film using at least one selected from the group consisting of Ti, Ta, Hf, Zr,
2. The magnetoresistive element according to claim 1, wherein the film is a film using at least one selected from Nb and V. 4. An exchange coupling film in which a base film, an antiferromagnetic film, and a ferromagnetic film are stacked in this order, wherein the base film is made of Ru, Rh, Ir, Cr, Re, Tc, Os. A magnetoresistive effect element comprising a single film, a laminated film, or an alloy film using at least one member selected from the group consisting of: 5. The method according to claim 1, wherein the underlayer is made of Ti, Ta, Hf, Zr,
A single film using at least one selected from Nb and V,
The magnetoresistive element according to claim 4, further comprising a laminated film or an alloy film. 6. The method according to claim 1, wherein the underlayer is made of Pd, Pt, Ag, Au,
The magnetoresistive element according to claim 4, further comprising a single film, a laminated film, or an alloy film using at least one selected from Zn, Cd, Al, Tl, and Pb. 7. The method according to claim 1, wherein the underlayer is made of Pd, Pt, Ag, Au,
A single film, a stacked film, or an alloy film using at least one selected from Zn, Cd, Al, Tl, and Pb;
At least one selected from Ta, Hf, Zr, Nb, and V
The magnetoresistive element according to claim 4, further comprising a single film, a laminated film, or an alloy film using a seed. 8. The method according to claim 1, wherein at least a part of the antiferromagnetic film has a face-centered cubic crystal structure.
7. The magnetoresistance effect element according to 7. 9. The magnetoresistive element according to claim 1, wherein at least a part of said antiferromagnetic film has a face-centered tetragonal crystal structure. 10. The antiferromagnetic film according to claim 1, wherein at least a part of said antiferromagnetic film has a body-centered cubic structure.
7. The magnetoresistance effect element according to 7. 11. The magnetoresistive element according to claim 1, wherein the <111> axis of the antiferromagnetic film is oriented in a direction perpendicular to the film surface. 12. The magnetoresistive element according to claim 1, wherein the half width of a rocking curve of the antiferromagnetic film by XRD is within 15 °. 13. The antiferromagnetic material film is composed of R _x Mn _100-x (R
Are Ir, Rh, Pt, Ru, Au, Ag, Co, Pd,
13. The magnetoresistance effect element according to claim 8, wherein the element has at least one element selected from Ge, Re, Ni, and Cu, and 5 ≦ x ≦ 40). 14. The antiferromagnetic film is made of R _x Mn _100-x (R
13. The magnetoresistive element according to claim 10, wherein the element has at least one element selected from Pt, Ni, Pd, and Cr, and 40 ≦ x ≦ 60. 15. An antiferromagnetic material film comprising (R _x Mn _1-x )
_100-y Fe _y (R is Ir, Rh, Pt, Ru, Au, A
g, at least one element selected from Co, Pd, Ge, Re, Ni and Cu, 5 ≦ x ≦ 40, 0 <y <30)
13. The magnetoresistive element according to claim 8, 11 or 12, comprising: 16. The method according to claim 16, wherein the antiferromagnetic film is (R _x Mn _1-x ).
_100-y Fe _y (R is at least one element selected from Pt, Ni, Pd and Cr, 40 ≦ x ≦ 60, 0 <y <3
The magnetoresistance effect element according to claim 10, wherein 0) is satisfied. 17. The antiferromagnetic film is made of Ta, Hf, Nb,
Si, Al, W, Zr, Ga, Be, In, Sn, V,
2. The composition according to claim 1, further comprising at least one selected from Mo, Os, Cd, Zn, N, Cr and Ni.
15. The magnetoresistive element according to items 3 and 14. 18. The antiferromagnetic film is made of Ta, Hf, Nb,
Si, Al, W, Zr, Ga, Be, In, Sn, V,
Mo, Os, Cd, Zn, N, Cr, Au, Ag, C
17. The magnetoresistive element according to claim 15, further comprising at least one selected from the group consisting of o, Re, and Ge. 19. The magnetoresistive effect according to claim 1, wherein the matching of the atomic spacing at the interface between the underlayer and the antiferromagnetic film is -6% or more and 15% or less. element. 20. A magnetoresistive element according to claim 1, wherein Co or Co alloy is used for said ferromagnetic film. 21. A first magnetization pinned layer using the ferromagnetic film on the antiferromagnetic film, and a magnetization free layer using a ferromagnetic film on the first magnetization pinned layer. 21. The magnetoresistive element according to claim 1, wherein 22. The magnetoresistive element according to claim 21, wherein a second pinned layer made of a ferromagnetic film is further disposed above the magnetization free layer. 23. The ferromagnetic film of the exchange coupling film has a laminated structure of a first ferromagnetic film / non-magnetic film / second ferromagnetic film. The magnetoresistive effect element as described in the above. 24. The magnetoresistive element according to claim 1, wherein the lower magnetic shield layer, a lower reproducing magnetic gap formed on the lower magnetic shield layer, and the lower reproducing magnetic gap are formed on the lower reproducing magnetic gap. A magnetic head, comprising: an effect element; an upper reproducing magnetic gap formed on the magnetoresistive effect element; and an upper magnetic shield layer formed on the upper reproducing magnetic gap. 25. A magnetic head comprising: a reproducing head using the magnetic head according to claim 1; and a magnetic disk, wherein information recorded on the magnetic disk is reproduced using the reproducing head. Disk device. 26. The method of manufacturing a magnetoresistive element according to claim 1, wherein said antiferromagnetic film has an oxygen content of 0.5.
A method for manufacturing a magnetoresistive element, wherein the method is performed by using an alloy target of not more than weight%.