JP3520242B2 - Magnetic head - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head using a ferromagnetic tunnel junction as a magnetic sensing section.

[0002]

2. Description of the Related Art As a reproducing magnetic head for high density magnetic recording, a magnetoresistive effect type magnetic head (hereinafter referred to as MR magnetic head) using an anisotropic magnetoresistive (hereinafter referred to as AMR) effect has been commercialized. . However, since the AMR effect film such as NiFe is used as the magnetic film, the magnetoresistance (MR) change rate is about 2% and the sensitivity is low at 0.5% / Oe. Therefore, an MR film having a higher MR change rate and a higher sensitivity is desired.

As a technique to meet such a demand, a new phenomenon called a giant magnetoresistive effect (GMR effect) has been found in recent years, and a larger magnetoresistive change rate than the conventional AMR effect can be obtained. Has been.
Among them, the GMR effect using a spin valve (SV) film is drawing attention. The spin valve film is a multi-layered film composed of a ferromagnetic film / non-magnetic metal film / ferromagnetic film / antiferromagnetic film, and exhibits high sensitivity of 2 to 5% / Oe. It has attracted attention as a head reproducing element, and research for its practical use has begun.

On the other hand, apart from the GMR effect, a phenomenon called a ferromagnetic tunnel effect, which has a junction structure of ferromagnetic film / insulating film / ferromagnetic film, and in which a tunnel effect appears depending on the relative angle of magnetization of both ferromagnetic films. Has been found, and research and development of a magnetoresistive effect element utilizing this phenomenon are under way. Since the ferromagnetic tunnel effect film has a very high magnetic field sensitivity, it has a possibility as a reproducing magnetic head in ultra high density magnetic recording of 10 Gbit / inch ² or more. S. Maekawa and V. Ga
fvert et al., IEEE Trans. Magn., MAG-18, 707 (1982), is expected to show a tunnel effect depending on the relative angle of magnetization of both magnetic films at a magnetic substance / insulator / magnetic substance junction. It was shown theoretically and experimentally.

Japanese Unexamined Patent Publication (Kokai) No. 4-42417 discloses a magnetic head having a ferromagnetic tunnel effect film.
Highly sensitive to minute changes in magnetic flux leakage compared to magnetic heads
It is also stated that the detection probability with high resolution and the reduction of the bonding area can reduce the probability of occurrence of pinholes in the insulating film and further improve the reproduction sensitivity.

Further, Japanese Patent Laid-Open No. 4-130014 discloses a ferromagnetic tunnel effect film for applying a bias magnetic field from an antiferromagnetic material to a magnetic film and a magnetic head using the film.

Furthermore, T. Miyazaki and N. Tezuka et al.
gn. Magn. Mater. 139 (1995) L231, it was reported that an MR ratio of 18% was obtained at room temperature in a Fe / Al ₂ O ₃ / Fe tunnel junction. Also, M. Pomerantz, JC Sloczewski, E. Spiller, and others disclose Fe / a-Carbon / Fe films.

However, the ferromagnetic tunnel junctions reported so far have various problems to be solved when used as a magnetic head. The biggest problem is to realize a magnetic head that can obtain a high MR change rate with good reproducibility.

Further, in order to apply the shield type magnetic head to high density recording / reproducing, it is necessary to narrow the shield interval on the ABS surface. In a shielded magnetic head, normally, in addition to the ferromagnetic tunnel junction between the shields, there is an insulating film such as alumina for maintaining the insulating property between the ferromagnetic tunnel junction and the shield film, so the shield interval is narrowed. Therefore, the thickness of the insulating film and the ferromagnetic tunnel junction must be made as thin as possible. However, as disclosed in a known document, when the electrode film is exposed on the ABS surface, even if the thickness of the insulating film or the ferromagnetic tunnel junction is reduced, the electrode film and the shield film still have a gap between the electrode film and the shield film. Since the space is required, the shield space cannot be narrowed, which is not suitable for high density recording / reproduction.

In the known literature, the area of the electrode film is increased in order to allow all the current to flow through the ferromagnetic tunnel junction. However, since it is necessary to have a dielectric withstanding voltage of a certain level or higher between the ferromagnetic tunnel junction and the shield film, static electricity will not be generated if exposed to the ABS surface with a wide electrode film area as shown in a known document. This is not desirable because it easily causes dielectric breakdown.

The ferromagnetic tunnel junction in the present invention is the same as the above-mentioned ferromagnetic tunnel effect film.

[0012]

An object of the present invention is to provide a ferromagnetic tunnel junction type magnetic head which can obtain a high MR change rate with good reproducibility.

The above-mentioned problems can be solved by claims 1 to 1 of the present invention.
It is solved by the invention of 4.

[0014]

[0015]

[0016]

1 is a perspective view of a magnetic head according to the present invention. In the figure, the dimensions are exaggerated. The illustrated magnetic head according to the present invention comprises a slider 1, a magnetic conversion element utilizing a ferromagnetic tunnel junction (hereinafter referred to as a ferromagnetic tunnel junction type magnetic conversion element) 2, and an induction type magnetic conversion element 3. including. The slider 1 has rail portions 11 and 12 on the medium facing surface side, and the surfaces of the rail portions 11 and 12 form air bearing surfaces 13 and 14. The rail portions 11 and 12 are not limited to two. It may have 1 to 3 rail portions, and may be a flat surface without rail portions. Further, in order to improve the levitation characteristics, various geometric shapes may be attached to the air bearing surface (hereinafter referred to as ABS surface). The present invention can be applied to any type of slider.

The magnetic conversion elements 2 and 3 have rail portions 11 and 1, respectively.
It is provided at the end of one or both of the two in the medium moving direction a1. The medium moving direction a1 coincides with the outflow direction of air entrained when the medium moves at high speed. Lead-out electrodes 41, 42 connected to the ferromagnetic tunnel junction type magnetic conversion element 2 and lead-out electrodes 43, 44 connected to the magnetic conversion element 3 are provided on the end surface of the slider 1 in the medium moving direction a1.

FIG. 2 is an enlarged sectional view of a magnetic conversion element portion of the ferromagnetic tunnel junction type magnetic head shown in FIG. The ferromagnetic tunnel junction type magnetic conversion element 2 is a reproducing element,
The inductive magnetic conversion element 3 is a writing element. Ferromagnetic tunnel junction type magnetic conversion element 2 and induction type magnetic conversion element 3
Are laminated on an insulating film 102 provided on a ceramic substrate 101 forming the slider 1. The ceramic substrate 101 is usually composed of Al ₂ O ₃ —TiC. Al ₂
Since O ₃ -TiC has conductivity, an insulating film 102 made of Al ₂ O ₃ , for example, is attached as a means for electrical insulation. When the ceramic base 101 has high insulation, the insulating film 102 can be omitted.

FIG. 3 is an enlarged sectional view of a portion of the ferromagnetic tunnel junction type magnetic conversion element 2, and FIG. 4 is an enlarged perspective view thereof.
As shown in these figures, the ferromagnetic tunnel junction type magnetic conversion element 2 includes a ferromagnetic tunnel junction portion 21 and an electrode film 2.
2 and 23, and are supported by insulating support films 24 and 25 that form a part of the slider 1. The ferromagnetic tunnel junction 21 includes the insulating film 210 and the first ferromagnetic film 21.
1 and a second ferromagnetic film 212. The first ferromagnetic film 211 and the second ferromagnetic film 212 are the insulating film 21.
They are stacked with 0 in between.

The electrode films 22 and 23 are the first electrode film 22.
And a second electrode film 23. First electrode film 2
2 is connected to the first ferromagnetic film 211, and the second electrode film 2
3 is connected to the second ferromagnetic film 212.

The first electrode film 22 and the second electrode film 23 are provided so as not to be exposed on the ABS surface 13 (or 14). As a specific means, in the embodiment, in the ferromagnetic tunnel junction portion 21, the tip for detecting the external magnetic field is located on the ABS surface 13 (or 14), and the first electrode film 22 and the second electrode film 23 are provided. Is the ABS surface 13 where the tip of the ferromagnetic tunnel junction 21 is located.
(Or 14), the distance D1 is set back.

The ferromagnetic tunnel junction type magnetic conversion element 2 is
First magnetic shield film 51 and second magnetic shield film 5
2 is disposed inside the insulating support films 24 and 25. The first magnetic shield film 51 is attached on the insulating film 102 provided on the ceramic substrate 101, and the insulating support film 24 is attached on the first magnetic shield film 51.

As mentioned above, the ABS surface 13 (or 1
By adopting a structure in which the first electrode film 22 and the second electrode film 23 are not exposed in 4), the first magnetic shield film 51
Also, electrostatic breakdown is less likely to occur between the second magnetic shield film 52 and the ferromagnetic tunnel junction type magnetic conversion element 2, particularly the first electrode film 22 and the second electrode film 23, and the withstand voltage is reduced. Have been found to improve.

Moreover, the space between the first magnetic shield film 51 and the second magnetic shield film 52 on the ABS surface 13 (or 14) and the ferromagnetic tunnel junction portion 21 serving as the magnetic sensitive portion can be narrowed. Higher density recording / reproducing than before is possible.

The embodiment shows a composite magnetic head having a ferromagnetic tunnel junction type magnetic conversion element 2 as a reproducing element and an inductive type magnetic conversion element 3 as a writing element. The inductive magnetic conversion element 3 includes a lower magnetic film 52, an upper magnetic film 32, and a coil film 3 which also serve as a second magnetic shield film for the ferromagnetic tunnel junction magnetic conversion element 2.
3, a gap film 34 made of alumina or the like, an insulating film 35 made of an organic resin such as novolac resin, and a protective film 36 made of alumina or the like. The tip portions of the lower magnetic film 52 and the upper magnetic film 32 are opposed to each other with a gap film 34 having a small thickness therebetween, and are opposed to each other.
The lower pole portion P1 and the upper pole portion P2
Write in. The lower magnetic film 52 and the upper magnetic film 32 are coupled to each other so as to complete a magnetic circuit in the back gap portion where the yoke portion is on the side opposite to the lower pole portion P1 and the upper pole portion P2.
Inside the insulating film 35, a coil film 33 is formed so as to spiral around the coupling portion of the yoke portion. Both ends of the coil film 33 are electrically connected to the extraction electrodes 43 and 44. The number of turns and the number of films of the coil film 33 are arbitrary.

Next, a method of manufacturing the magnetic head according to the present invention will be described with reference to FIGS.

First, the alumina insulating film 10 having a thickness of 30 μm is formed.
2 was formed on the AlTiC substrate 101 (see FIG. 5) on which the sendust was sputtered by DC sputtering to obtain a film thickness of 2 μm.
First magnetic shield film 51 is formed (see FIG. 6), and then heat treatment is performed in a magnetic field at a temperature of about 450 ° C. for about 2 hours in vacuum, and then predetermined by photolithography and Ar ion etching. It has a shape of.

Next, an alumina film having a thickness of 100 nm is formed as the insulating film 24 by the RF sputtering method (see FIG. 7), and then a Ta / Cu / Ta film is formed as the first electrode film 22 by DC.
A film was formed by the sputtering method (see FIG. 8). After that, patterning was performed using a resist and then processed into a predetermined shape by Ar ion etching to form the first electrode film 22 (see FIG. 9).

Next, as a means for forming the ferromagnetic tunnel junction portion 21, Co-50at% Fe (10nm) / aluminum oxide (5n
m) / Fe (5 nm) and its surface anti-oxidation film Ta (5 nm) were prepared as follows. First, Co-50at% on the first electrode film 22.
Fe (10 nm) / Al (5 nm) was continuously deposited by the DC sputtering method. Then, the sample was taken out into the air and left in the air at about 60 ° C. for 24 hours for annealing to naturally oxidize Al (5 nm). As a result, the first ferromagnetic film 211 and Co-50at% Fe (10nm) / aluminum oxide to be the intermediate insulating film 210 are formed.
A (5 nm) film was formed (see FIG. 10).

Thereafter, in order to form the short-circuit preventing insulating film 213, the area other than the tunnel junction portion to be formed is covered with a resist, and the alumina insulating film (film thickness is formed by RF sputtering.
50 nm) was deposited. After that, the resist was lifted off to form a short-circuit prevention insulating film 213 (see FIG. 11). The insulating film 213 is formed so as to prevent the tunnel current from flowing except in the ferromagnetic tunnel junction portion 21.

Next, the sample was set in the DC sputtering apparatus again, and Fe (5 nm) and Ta (5 nm) were continuously formed to form the second ferromagnetic film 212 (see FIGS. 12 and 13). The Ta (5 nm) film serves as a protective film that prevents the surface from being oxidized during the process.

Next, patterning is performed using a resist,
After Ar ion etching, remove the resist,
The ferromagnetic tunnel junction 21 was formed. Next, patterning is performed again using a resist, followed by Ta / Cu / Ta.
A film was formed, and then the second electrode film 23 was formed by the lift-off method (see FIG. 14).

Next, as the upper insulating film 25, a film thickness of 12
A 0 nm alumina film was formed by RF sputtering (FIG. 15). Next, as the second magnetic shield film 52, NiFe (film thickness 2 μm) was formed by the DC sputtering method, and then patterned into a predetermined shape by the photolithography and etching technique (see FIG. 16).

Thereafter, the steps necessary to obtain the magnetic head shown in FIGS. 1 and 2 are performed, and further, X1 in FIG.
The ferromagnetic tunnel junction portion 21 was exposed on the ABS surface by cutting the wafer and performing polishing along the line X1. As described above, a magnetic head having a ferromagnetic tunnel junction portion 21 having a junction area of 1 μm × 2 μm (junction height 1 μm, junction width 2 μm) was obtained.

For comparison, a ferromagnetic tunnel junction type magnetic head in which the electrode films 22 and 23 were exposed on the ABS surface was also manufactured.

<Characteristic Evaluation> The manufactured magnetic head was attached to a magnetic head gimbal and an electrostatic breakdown test was conducted. In the electrostatic breakdown test, a metal plate having a polished surface was prepared, a power source was connected to this metal plate, and a magnetic head was placed on the metal plate. The magnetic head was connected to ground, and the relationship between the resistance between the magnetic head and the metal plate and the voltage applied to the metal plate was investigated. As a result, in the conventional magnetic head in which the electrode films 22 and 23 were exposed on the ABS surface, the resistance sharply increased at the applied voltage of 50 V and electrostatic breakdown occurred. In contrast,
It has been found that the magnetic head of the present invention causes electrostatic breakdown for the first time at about 150 V and has a withstand voltage about three times that of the conventional magnetic head.

The insulating film 210 provided between the first ferromagnetic film 211 and the second ferromagnetic film 212 is for obtaining a high MR change rate with good reproducibility and for simplifying the magnetic head structure. It plays an extremely important role. In particular, the barrier potential of the insulating film 210 is 0.5 to
When set in the range of 3 eV, a high MR change rate can be obtained with good reproducibility and the magnetic head structure can be simplified. Next, this point will be described.

In the ferromagnetic tunnel junction, from the first ferromagnetic film 211, the electron e maintains its spin direction.
When passing through the second ferromagnetic film 212 through the insulating film 210, the transmittance of the electron e is obtained from the amplitude square ratio of the incident wave and the transmitted wave by using the wave function obtained in consideration of spin, The tunnel conductance G is expressed as G = G ₀ ′ (1 + P ₁ ′ · P ₂ ′) COSθ. Where P ₁ ′ = [(K _{1 ↑} -K _{1 ↓} ) / (K _{1 ↑} + K _{1 ↓} )] α ₁ P ₂ ′ = [(K _{2 ↑} -K _{2 ↓} ) / (K _{2 ↑} + K _{2 ↓} )] α ₂ G ₀ ′: Electron wavenumbers K _{1 ↑} , K _{1 ↓} , K _{2 ↑} , K in both ferromagnetic films
_{2 ↓} and constants determined by the height of barrier potential α ₁ , α ₂ : Coefficients P ₁ ′, P ₂ ′: Effective spin polarization P ₁ , P of both ferromagnetic films 1 and ₂ depending on the height of barrier potential ₂ : The spin polarization of both ferromagnetic films 1 and 2 (the fractional part of the effective spin polarization P ₁ ′ and P ₂ ′). The rate of change of tunnel conductance ΔG / G ₀ is ΔG / G ₀ = 2 · P ₁ ′ · P ₂ ′. Change rate of tunnel conductance △ G / G ₀ is MR
It is synonymous with the rate of change.

If the barrier potential is low,
Coefficient α depending on₁, Α₂Both ferromagnetic films
Effective spin polarization P of₁′, P₂′ Also becomes smaller, MR change
The rate is low. On the contrary, the barrier potential is sufficiently high
And the effective spin polarization P₁′, P ₂′ Is the spin polarization P₁, P
₂And a high MR change rate is obtained.

When the barrier potential is in the range of 0.5 to 3 eV, a high MR change rate can be obtained with good reproducibility. One of the reasons is that the barrier potential is 0.
It is presumed that keeping the range of 5 to 3 eV ensures the formation of the insulating film 210 with good uniformity and very few pinholes.

Another reason is that in the above-mentioned range of barrier potential, a stable antiferromagnetic property is provided between the first ferromagnetic film 211 and the second ferromagnetic film 212 via the insulating film 210. It is presumed that it causes binding. Particularly preferable results were obtained when the barrier potential was in the range of 1.5 to 2.5 eV.

When the barrier potential exceeds 3 eV, a high MR change rate cannot be obtained. The cause is not clear, but it is presumed that tunnel current does not flow in the range of barrier potential over 3 eV.

If the barrier potential is less than 0.5 eV, it is impossible to obtain the high MR change rate expected in this type of ferromagnetic tunnel junction. It is presumed that the reason is that the uniformity of the insulating film 210 deteriorates and the number of pinholes increases.

Next, the barrier potential is 0.5 to 3 eV.
In such a range, stable antiferromagnetic coupling may be generated between the first ferromagnetic film 211 and the second ferromagnetic film 212 via the insulating film 210. A great advantage is brought about when the tunnel junction is used for a read magnetic conversion element of a magnetic head.

FIG. 18 is a diagram showing a magnetic field-magnetoresistance change rate characteristic when antiferromagnetic coupling is generated. As shown in FIG. 18, when the antiferromagnetic coupling is generated, the magnetic field-magnetoresistance curves L1 and L2 are M in the region ΔH near the zero magnetic field.
The R change rate shows the highest value. Therefore, when this ferromagnetic tunnel junction is used as a read magnetic conversion element of a magnetic head, it is not necessary to apply a bias magnetic field, and a linear region can be obtained near the zero magnetic field only by the shape effect. Therefore, the structure of the magnetic head can be simplified (see FIGS. 3 and 4).

An example of the insulating film 210 that can secure the barrier potential as described above is an aluminum oxide film annealed at 40 to 100 ° C. in the atmosphere. In such an aluminum oxide film, since metal aluminum is not locally present, a bridge cannot be formed between the upper and lower ferromagnetic films 211-212, and as a result, the ferromagnetic tunnel having the ultrathin insulating film 210 having a high barrier potential is formed. Bonding can be realized.

As another example of the insulating film 210, a diamond-like carbon film (hereinafter referred to as a DLC film) is also effective for realizing the extremely thin insulating film 210 having a high barrier potential. is there. In particular, the DLC film produced by the plasma CVD method can obtain a good insulating film 210 that is uniform and has no pinhole even if the film thickness is very thin, such as several tens of liters.

Incidentally, M. Pomerantz, JC Sloczewski and E.
The intermediate C film disclosed by Spiller et al. Is an amorphous-C film produced by the MBE method, and is different from the DLC film produced by the plasma CVD method. Specifically, in the amorphous-C film, carbons are bonded to each other in a network shape, but in the DLC film of the present invention, carbon and hydrogen are networked.
They are joined together in the shape of a circle and are essentially different.

In the present invention, the first ferromagnetic film 2 is usually used.
The coercive force of 11 and the coercive force of the second ferromagnetic film 212 are
Make them different from each other. FIG. 19 shows the coercive force H1 of the first ferromagnetic film 211 and the coercive force H2 of the second ferromagnetic film 212.
The magnetization curves are shown when different as in H1> H2 (or H2> H1). As shown in the figure, the magnetization curve has a two-step loop. In FIG. 19, the two arrows shown in the circle indicate the magnetization direction of the first ferromagnetic film 211 and the magnetization direction of the second ferromagnetic film 212, respectively.

The magnetization direction of the first ferromagnetic film 211 and the magnetization direction of the second ferromagnetic film 212 are such that the applied magnetic field is larger than the coercive force H2 (absolute value) and the coercive force H1 (absolute value). When the applied magnetic field is larger than the coercive force H1, it becomes parallel. The electric resistance is large when the magnetization directions are antiparallel, and decreases when the magnetization directions are parallel. The MR change rate is ΔR / Rs, where Rs is the resistance value when the magnetization directions are parallel and ΔR is the change in resistance when the magnetization direction changes from antiparallel to parallel. Thereby, the externally applied magnetic field can be detected.

As another example, the magnetization direction of the second ferromagnetic film 212 is fixed. By doing so, by changing only the magnetization direction of the first ferromagnetic film 211,
The magnetization direction of the first ferromagnetic film 211 with respect to the second ferromagnetic film 212 can be parallel or antiparallel.

Next, the junction area of the ferromagnetic tunnel junction 21 and the insulating film 210 will be described with reference to examples.

Example 1 In the manufacturing method shown in FIGS. 5 to 17, the insulating film 210 made of an aluminum oxide film is used.
Was formed by heat-treating an aluminum film in the atmosphere at 60 ° C. for 24 hours. The junction area of the ferromagnetic tunnel junction was 0.25 to 2500 μm ² .

20 ferromagnetic tunnel junctions each having the above-mentioned junction area were produced, and the barrier potential, the average value of the MR change rate and its variation were examined for each junction area. The yield was also investigated. Next, a method of manufacturing the ferromagnetic tunnel junction will be specifically described.

First, as the first ferromagnetic film 211, a NiFe film having a film thickness of 10 nm is formed by the RF sputtering method, and 0.5 to 50 μm × is formed by using a fine processing technique such as resist photolithography, Ar ion milling, and resist peeling. Patterned in a rectangle of 0.5 mm
I learned.

After that, resist patterning is performed to remove the surface oxide film of the NiFe film forming the first ferromagnetic film 211 by reverse sputtering, and then an aluminum film having a thickness of 5 nm is formed by an electron beam heating vacuum deposition method. Was deposited.

After that, the sample was taken out from the vacuum vapor deposition apparatus, heat-treated in the atmosphere at 60 ° C. for 24 hours, and then subjected to a lift-off process to form an insulating film 210 made of an aluminum oxide film.

Next, after resist patterning is performed again, a C film having a film thickness of 100 nm is formed as a second ferromagnetic film 212.
An o film is formed by RF sputtering, followed by a lift-off process, and 0.5 film is formed in a direction perpendicular to the first ferromagnetic film 211.
A second ferromagnetic film 212 having a rectangular pattern of .about.50 .mu.m.times.0.5 mm was formed. As a result, the bonding area is 0.25 to 2
A ferromagnetic tunnel junction of 500 μm ² was obtained.

Further, as a comparison, a NiFe / aluminum oxide / Co ferromagnetic tunnel junction in which a conventionally used natural aluminum oxide film (after film formation, left in the atmosphere for 24 hours) was used as the insulating film 210 was similarly prepared. .

First adopted in Examples and Comparative Examples
The film forming conditions for the ferromagnetic film 211 and the second ferromagnetic film 212 are as follows. Also, the aluminum film is
It was prepared at an ultimate pressure of 3 × 10 ⁻⁵ Pa and a deposition rate of 0.05 nm / sec.

<Ferromagnetic film forming conditions> Ultimate pressure: 1 × 10 ⁻⁵ Pa Target: Ni ₈₀ Fe ₂₀ at%, Co (4 inches φ) Sputtering gas: Ar 5 sccm Sputtering pressure: 0.5 Pa Input power: 150 W Film formation rate: NiFe 45 nm / min, Co 40 nm / min Substrate temperature: Water cooling The magnetoresistive (MR) curve of the sample thus prepared was measured by the direct current 4-terminal method. The maximum applied magnetic field during measurement was ± 1 kOe, and after applying a magnetic field of -1 kOe, the magnetic field was gradually increased to +1 kOe and returned to -1 kOe again. For the barrier potential, the VI characteristic of the tunnel junction was measured to find the deviation from the linear region.

FIG. 20 shows a joint area of 50 × 50 according to the present invention.
The magnetoresistance curve of a μm ² ferromagnetic tunnel junction is shown. When the applied magnetic field is made larger than -1 kOe, the magnetization reversal of the first ferromagnetic film 211 occurs at +5 Oe, and the spins of the first ferromagnetic film 211 and the second ferromagnetic film 212 become antiparallel. Therefore, the electric resistance increases. The barrier potential was calculated to be 0.5 eV, and similar MR curves were obtained for 16 of the 20 manufactured. The MR change rate was 6.6 to 8.1%, the average MR change rate was 7.6%, and the change rate variation was ± 7%.

On the other hand, the natural aluminum oxide film is replaced with the insulating film 2.
In the ferromagnetic tunnel junction of Comparative Example No. 10, the barrier potential was only 0.2 eV. Further, only four MR curves could be observed, the average value of MR change rate was as low as 1.5%, and the average value variation was ± 88%, which was very large. The same evaluation was performed for various bonded areas. The results are shown in Tables 1-1 and 1-2.

As is clear from Table 1, the aluminum oxide film formed by the heat treatment at 60 ° C. in the atmosphere is replaced with the insulating film 210.
As a result, a high barrier potential of 0.5 to 3 eV and a high MR change rate can be obtained, and there is little variation and a high yield can be obtained. In particular, the yield is high when the barrier potential is 1.5 to 2.5 eV. Further, as a result of examining the MR characteristics of the ferromagnetic tunnel junction using the aluminum oxide film obtained by heat treatment in the air in the temperature range of 30 to 250 ° C. as the insulating film 210, a high MR is obtained when the heat treatment is performed at 40 to 100 ° C. It was found that the rate of change was obtained, the variation was small, and the yield was high.

Example 2 The first ferromagnetic film 211 is made of Co _50.
Fe ₅₀ was used, and the second ferromagnetic film 212 was made of Co. The bonding area was 0.25 to 2500 μm ² . The first ferromagnetic film 211 and the second ferromagnetic film 212 were manufactured by the same method as in Example 1. The DLC film forming the insulating film 210 was formed to a thickness of 5 nm by the plasma CVD method and patterned by the lift-off method. The film forming conditions for the DLC film are shown below.

<DLC film forming conditions> Ultimate pressure: 2 × 10 ⁻³ Pa Introducing gas: Methane 5 sccm Sputtering pressure: 3.5 Pa RF power: 50 W Self-bias: −150 V Film forming rate: 10 nm / min Substrate temperature: No heating or water cooling Further, as a comparative example, a Co ₅₀ Fe ₅₀ / aluminum oxide / Co ferromagnetic tunnel junction having a natural aluminum oxide film as the insulating film 210 was prepared.

Tables 2-1 and 2-2 show the results obtained by measuring the MR characteristics of the samples of the above Examples and Comparative Examples by the DC 4-terminal method.

Tables 2-1 and 2-2 show the results obtained by measuring the MR characteristics of the samples of the above-mentioned Examples and Comparative Examples by the DC 4-terminal method.

As is clear from Table 2, plasma CVD
It can be seen that by using the DLC film manufactured by the method as the insulating film 210, a high barrier potential and a high MR change rate can be obtained, and further, there is little variation and a high yield can be obtained. For example, a sample having a junction area of 50 × 50 μm ² according to this example was prepared 20.
The MR curve was obtained for 15 of them. The average MR change rate was 18.9%, and the variation in change rate was ± 12%. Moreover, as in Example 1, the yield was particularly high when the barrier potential was 1.5 to 2.5 eV. On the other hand, in the ferromagnetic tunnel junction of the comparative example using the natural aluminum oxide film as the insulating film 210, the barrier potential is small and only 5 MR curves can be observed.
The average change rate was as low as 3.3%, and the variation was ± 88%, which was very large.

Next, the relationship between the junction area and the reversal magnetic field will be described. It has been reported that the smaller the bonding area, the smaller the number of defects such as pinholes in the insulating film 210 and the higher the yield. As can be seen from Table 1 and Table 2, in the ferromagnetic tunnel junction of this example, the smaller the junction area, the higher the MR change rate and the higher the yield. In particular, the yield increases when the barrier potential is 1.5 to 2.5 eV.

The magnetic field Hab shown in FIG. 20, that is, the first magnetic field
It was found that the magnetic field for reversing the magnetization of the ferromagnetic film 211 of 1 was shifted in the negative direction. Especially, the joint area is 10
Smaller than μm ² and barrier potential 1.5 to 2.5 eV
At this time, in the zero magnetic field, the magnetizations of the first ferromagnetic film 211 and the second ferromagnetic film 212 are in antiparallel states. This indicates that the antiferromagnetic coupling force acts between both magnetic films. The high MR change rate and the high yield were obtained when the junction area was smaller than 10 μm ² because the insulating film 210 which was uniform and had very few pinholes was used, and the junction area was made small, so that both magnetic films It is considered that antiferromagnetic coupling occurred between them. Example 1
-7 and Example 2-8, the bonding area is 10μ.
If the barrier potential is larger than 2.5 eV even at m ² or less, antiferromagnetic junction cannot be obtained between both magnetic films, and the yield is slightly reduced.

Next, the magnetic head according to the present invention and the conventional A
The characteristics of the MR magnetic head will be evaluated.

<Magnetic Head of the Present Invention> Co according to the second embodiment
₅₀Fe₅₀Magnetic head using a / DLC / Co ferromagnetic tunnel junction
And read the recording signal written on the magnetic recording medium.
Output, reproduction sensitivity and reproduction output, and conventional AMR magnet
Compared with the Ki head. The magnetic head according to the present invention is
Width of magnetic tunnel junction 21 1 μm , Length 1 μm And
That is, the track width of the magnetic head is 1 μm and MR
The height is 1 μm. MR shield interval is 0.27 μm
And

<Conventional AMR Magnetic Head: Comparative Example> For comparison, a conventional AMR magnetic head having a track width of 1 μm, an MR height of 1 μm, and an MR shield interval of 0.27 μm using an SAL bias type NiFe film as an MR film. Also made. The manufacturing method is shown below. The process up to formation of the lower insulating film is the same as that of the ferromagnetic tunnel junction type MR magnetic head of the present invention. After forming the lower insulating film, first, NiFeRh film as SAL film,
Ta film as the magnetic separation film and NiFe film as the MR film
A film was formed by the C sputtering method and processed into a rectangular shape by a fine processing technique. After that, an electrode film, an upper insulating film and an upper shield film were formed by a thin film and a fine processing technique.

Using this magnetic head, coercive force 2500
A recording signal written in a magnetic recording medium having Oe and a film thickness of 50 nm was reproduced to examine the characteristics.

FIG. 21 is a diagram comparing the reproduction output per unit track width with the recording density. A curve L3 shows the characteristics of the magnetic head using the ferromagnetic tunnel junction according to the present invention, and a curve L4 shows the characteristics of the conventional AMR magnetic head. As shown in FIG. 21, according to the ferromagnetic tunnel junction type magnetic head of the present invention, a reproduction output which is 4 to 5 times that of the conventional AMR magnetic head was obtained.

Next, in the ferromagnetic tunnel junction type magnetic head according to the present invention, the ferromagnetic tunnel junction portion 21 is provided with the magnetic control means in the first ferromagnetic film 211 or the second ferromagnetic film 212. Sometimes. One of such means is the first ferromagnetic film 211 or the second ferromagnetic film 21.
2 is to fix the magnetization direction of either one of them, and another means is to fix the magnetization of one of the first ferromagnetic film 211 and the second ferromagnetic film 212 which has not been fixed. To give magnetic domain control. These means are usually used in combination, but may be used alone.

<Magnetization Fixing Means> First, the magnetization fixing means will be described. The change in the magnetoresistance of the ferromagnetic tunnel junction 21 depends on the relative angle between the magnetization direction of the first ferromagnetic film 211 and the magnetization direction of the second ferromagnetic film 212.
In order to obtain a high reproduction output with a minute magnetic field, it is desirable that the magnetization directions of the first ferromagnetic film 211 and the second ferromagnetic film 212 are not parallel to each other when the external magnetic field is zero. For example, the magnetization directions of the first ferromagnetic film 211 and the second ferromagnetic film 212 are set in directions orthogonal to each other.

Particularly, for the external magnetic field, the first ferromagnetic film 2
The magnetization direction of 11 is perpendicular to the second ferromagnetic film 212.
It is preferable to orient the magnets so that their magnetization directions are parallel to each other.

Further, the first ferromagnetic film 211 operates as a free ferromagnetic film whose magnetization direction freely changes with respect to an external magnetic field, and the second ferromagnetic film 212 operates with respect to the external magnetic field. It is desirable to operate as a pinned ferromagnetic film in which is fixed. By doing so, only the movement of the magnetization of the first ferromagnetic film 211, which is a free ferromagnetic film,
A relative angle change can be generated between the ferromagnetic films 211 and 212 with respect to the magnetization direction. In this case, the easy axis of magnetization of the first ferromagnetic film 211 forming the free ferromagnetic film becomes perpendicular to the external magnetic field, and the easy axis of magnetization of the second ferromagnetic film 212 forming the pinned ferromagnetic film becomes perpendicular. It is better to set so that they are parallel to each other. By doing so, the direction of magnetization of the first ferromagnetic film 211, which is a free ferromagnetic film, changes in the magnetization rotation mode due to the external magnetic field, so that high MR sensitivity is obtained and smooth magnetization reversal is performed. It is possible to reduce the occurrence of Barkhausen noise associated with domain wall movement.

The easy axis of magnetization of the first ferromagnetic film 211, which is a free ferromagnetic film, is perpendicular to the external magnetic field, and the easy axis of the second ferromagnetic film 212, which is a pinned ferromagnetic film, is parallel to the external magnetic field. The following methods are available as means for directing. In the first method, a soft ferromagnetic film having a low coercive force is used as the first ferromagnetic film 211 that is a free ferromagnetic film, and a hard ferromagnetic film having a high coercive force is used as the second ferromagnetic film 212 that is a pinning ferromagnetic film. This is a method using a magnetic film. In the second method, both the first ferromagnetic film 211 and the second ferromagnetic film 212 are made of a soft ferromagnetic film, and the magnetization is fixed to the second ferromagnetic film 212 which is a pinned ferromagnetic film. The films are laminated to form the second ferromagnetic film 21.
This is a method of fixing the magnetization direction of No. 2.

Next, a specific example of the magnetization fixing means for satisfying the above requirements will be described with reference to FIGS.

FIG. 22 is a sectional view showing the ferromagnetic tunnel junction 21 of the magnetic head according to the present invention, and FIG. 23 is a perspective view of the ferromagnetic tunnel junction 21. In this embodiment, the second
The magnetization fixed film 216 is provided on the surface of the ferromagnetic film 212.
The magnetization fixed film 216 is provided between the second ferromagnetic film 212 and the second electrode film 23, and has the second ferromagnetic film 21.
2 serves as a pinned ferromagnetic film, and the first ferromagnetic film 211 serves as a free ferromagnetic film. Although illustration is omitted, the magnetization fixed film 216 is composed of the first ferromagnetic film 211 and the first electrode film 22.
It may be provided between and. In this case, the first ferromagnetic film 2
11 serves as a pinned ferromagnetic film, and the second ferromagnetic film 212
Becomes a free ferromagnetic film.

In the embodiment, the magnetization direction M1 of the first ferromagnetic film 211 is parallel to the ABS plane 13 (or 14), and the magnetization direction M2 of the second ferromagnetic film 212 is the fixed magnetization film 216. Is fixed in a direction perpendicular to the ABS surface 13 (or 14).

As the magnetization fixed film 216, either a hard ferromagnetic film having a high coercive force or an antiferromagnetic film can be used. When a hard ferromagnetic film is used as the magnetization fixed film 216, the magnetization fixed film 216 and the second ferromagnetic film 212 are used.
Exchange coupling between the ferromagnetic film and the ferromagnetic film occurs between the
The magnetization direction of the ferromagnetic film 212 is fixed, and the pinned ferromagnetic film is formed. When an antiferromagnetic film is used as the magnetization fixed film 216, an exchange coupling due to the antiferromagnetic film-ferromagnetic film occurs between the magnetization fixed film 216 and the second ferromagnetic film 212, which causes the second strong film. The magnetization direction of the magnetic film 212 is fixed, and the pinned ferromagnetic film is formed.

As the hard ferromagnetic film, a Co alloy such as CoPt, CoPtCr, CoPtTa, CoPtTaCr can be used. As the antiferromagnetic film, a metal antiferromagnetic material or an oxide antiferromagnetic material can be used. An example of the metallic antiferromagnetic material is a Mn alloy. FeMn, NiMn, PtMn, RuMn, RhMn, IrMn, PdMn are available as Mn alloys.
And their alloys. Examples of oxide-based antiferromagnetic materials are NiO, NiCoO, Fe ₂ O ₃ , and CoO.

FIG. 24 is a diagram for explaining the operation of the ferromagnetic tunnel junction portion 21 of the magnetic head shown in FIGS. 22 and 23. When the applied magnetic field H is zero, the magnetization direction M2 of the second ferromagnetic film 212 is controlled by the magnetization fixed film 216 (see FIGS. 22 and 23) so as to be perpendicular to the ABS surface 13 (or 14). ing. The magnetization direction M1 of the first ferromagnetic film 211 is parallel to the ABS 13 (or 14). In this state, when a magnetic field H is applied from a magnetic recording medium such as a magnetic disk, the magnetization direction M2 of the second ferromagnetic film 212 pinned by the magnetization fixed film 216 does not change, but the first The magnetization direction M1 of the ferromagnetic film 211 changes by an angle θ, for example. This produces a magnetoresistive effect.

<Magnetic Domain Control Means> Next, the magnetic domain control means for the free ferromagnetic film which is not fixed in magnetization will be described. In this type of magnetic head, the ferromagnetic tunnel junction 21 is formed as a fine rectangular pattern.
In such a pattern, it is unavoidable that a magnetically unstable portion is generated at the end of the pattern and a magnetic domain is formed. Therefore, the magnetization reversal in the domain wall motion mode partially occurs, and noise is generated. Therefore, a magnetic domain control film is provided at the end of the free ferromagnetic film to suppress magnetic domain formation in the free ferromagnetic film. The magnetic domain control film is a magnetic bias film.

FIG. 25 is a plan view showing the ferromagnetic tunnel junction portion 21 of the magnetic head according to the present invention, and FIG.
FIG. 6 is a sectional view taken along line 6-26. This embodiment is the second
2 shows an example in which the ferromagnetic film 212 of FIG.
Bias magnetic films 214 and 215 serving as magnetic domain control films are formed on both ends of the ferromagnetic film 212 of the second ferromagnetic film 21.
2 in a single domain state. Bias magnetic film 214,
As 215, a hard ferromagnetic film or an antiferromagnetic film can be used. Such bias magnetic films 214, 2
By disposing 15, the second ferromagnetic film 212 provided therewith can be brought into a single magnetic domain state,
It is possible to suppress the generation of Barkhausen noise that causes output waveform distortion.

Materials such as CoPt, CoPtCr, and CoPtTa can be used for the hard ferromagnetic films forming the bias magnetic films 214 and 215. In addition, as an antiferromagnetic film, FeM
Antiferromagnetic materials such as n, NiMn, PtMn, PdMn, RhMn, CrAl, and CrSb, and oxide antiferromagnetism such as NiO and α-Fe ₂ O ₃ can be used.

FIG. 27 is a sectional view showing another example of the ferromagnetic tunnel junction portion 21 of the magnetic head according to the present invention. This example shows an example in which the first ferromagnetic film 211 is a free ferromagnetic film, and bias magnetic films 214 and 215 serving as magnetic domain control films are formed on both ends of the first ferromagnetic film 211. First
Holding the ferromagnetic film 211 in the single magnetic domain state.

As shown in FIGS. 25 to 27, even when the bias magnetic films 214 and 215 to be the magnetic domain control films are provided, the first ferromagnetic film 211 or the second ferromagnetic film 212 is provided.
It is desirable that the magnetization directions are not parallel to each other.
For example, when the applied magnetic field is zero, the first ferromagnetic film 211
Alternatively, the magnetization direction of one of the second ferromagnetic films 212 is controlled to be parallel to the ABS plane 13 (or 14) and the magnetization direction of the other ferromagnetic film is perpendicular to the ABS plane. To do.

In the ferromagnetic tunnel junction type magnetic head having the structure shown in FIGS. 25 and 26, a ferromagnetic tunnel junction having a film structure of Fe (20 nm) / aluminum oxide (4 nm) / Co-10 at% Fe (10 nm). The part 21 was used as the magnetic sensing part. The bias magnetic film 21 is formed on both ends of the second ferromagnetic film 212 made of Co-10at% Fe.
4, hard magnetic films made of CoPt are arranged.

Using this magnetic head, an electrostatic breakdown test was conducted in the same manner as in Example 1. As a result, electrostatic breakdown occurred when the applied voltage to the metal plate was about 180 V, and the withstand voltage was higher than that of the conventional magnetic head. It was In addition, coercive force 2500 Oe, film thickness 50
As a result of reproducing the signal written in the magnetic recording medium of nm and examining the output waveform, a good waveform without distortion was obtained as shown in FIG.

<Combination of Magnetization Fixation and Magnetic Domain Control> FIG. 29 is a sectional view showing another example of the ferromagnetic tunnel junction portion 21 of the magnetic head according to the present invention. In this embodiment, the first ferromagnetic film 211 is a free ferromagnetic film, and the second ferromagnetic film 212 is used.
Shows an example in which is a pinned ferromagnetic film. Magnetic domain control films 214 and 215 are provided on both ends of the first ferromagnetic film 211, and a magnetization fixed film 216 is provided on the second ferromagnetic film 212.

FIG. 30 is a diagram for explaining the operation of the ferromagnetic tunnel junction portion 21 of the magnetic head shown in FIG. When the applied magnetic field H is zero, the magnetization direction M2 of the second ferromagnetic film 212 is fixed by the magnetization fixed film 216 in a direction perpendicular to the ABS plane 13 (or 14). The magnetization direction M1 of the first ferromagnetic film 211 is parallel to the ABS 13 (or 14). In this state, when a magnetic field H is applied from a magnetic recording medium such as a magnetic disk, the magnetization direction M2 of the second ferromagnetic film 212 pinned by the magnetization fixed film 216 does not change, but the first The magnetization direction M1 of the ferromagnetic film 211 changes by an angle θ, for example. This produces a magnetoresistive effect.

[0097]

As described above, according to the present invention, it is possible to provide a ferromagnetic tunnel junction type magnetic head capable of obtaining a high MR change rate with good reproducibility.

[Brief description of drawings]

FIG. 1 is a perspective view of a magnetic head according to the present invention.

FIG. 2 is an enlarged cross-sectional view of a magnetic conversion element portion of the magnetic head shown in FIG.

FIG. 3 is an enlarged sectional view of a portion of an MR magnetic conversion element.

FIG. 4 is an enlarged perspective view of an MR magnetic conversion element.

FIG. 5 is a diagram illustrating a method of manufacturing the magnetic head according to the present invention.

FIG. 6 is a diagram for explaining a method of manufacturing the magnetic head according to the present invention, which is a step subsequent to the step of FIG. 5;

FIG. 7 is a diagram for explaining a method of manufacturing the magnetic head according to the present invention, which is a step following the step of FIG. 6;

FIG. 8 is a diagram for explaining a method of manufacturing the magnetic head according to the present invention, which is a step following the step of FIG. 7;

9 is a step that is a step after the step of FIG. 8 and is a diagram illustrating a method of manufacturing the magnetic head according to the present invention. FIG.

10 is a diagram for explaining a method of manufacturing the magnetic head according to the present invention, which is a step following the step of FIG. 9;

FIG. 11 is a step that is a step after the step of FIG. 10 and is a diagram illustrating a method of manufacturing the magnetic head according to the present invention.

FIG. 12 is a step that is a step after the step of FIG. 11 and is a diagram illustrating a method of manufacturing the magnetic head according to the present invention.

13 is a step that is a step after the step of FIG. 12 and is a diagram illustrating a method of manufacturing the magnetic head according to the present invention. FIG.

FIG. 14 is a diagram for explaining a method of manufacturing the magnetic head according to the present invention, which is a step following the step of FIG. 13;

15 is a step that is a step after the step of FIG. 14 and is a diagram illustrating a method of manufacturing the magnetic head according to the present invention. FIG.

16 is a step that is a step after the step of FIG. 15 and is a view for explaining the method of manufacturing the magnetic head according to the present invention. FIG.

FIG. 17 is a diagram for explaining a method of manufacturing the magnetic head according to the present invention, which is a step following the step of FIG. 16;

FIG. 18 is a diagram showing a magnetic field-magnetoresistance change rate characteristic when antiferromagnetic coupling is generated.

FIG. 19 shows a magnetization curve when the coercive force H1 of the first ferromagnetic film and the coercive force H2 of the second ferromagnetic film are made different such that H1> H2.

FIG. 20 shows a magnetoresistance curve of a ferromagnetic tunnel junction having a junction area of 50 × 50 μm ² .

FIG. 21 is a diagram comparing reproduction output and recording density per unit track width.

FIG. 22 is a sectional view showing a ferromagnetic tunnel junction portion of the magnetic head according to the present invention.

FIG. 23 is a perspective view of a ferromagnetic tunnel junction portion of the magnetic head according to the present invention.

FIG. 24 is a diagram for explaining the operation of the ferromagnetic tunnel junction of the magnetic head shown in FIGS. 22 and 23.

FIG. 25 is a plan view showing a ferromagnetic tunnel junction portion of the magnetic head according to the present invention.

26 is a sectional view taken along the line 26-26 of FIG.

FIG. 27 is a cross-sectional view showing another example of the ferromagnetic tunnel junction portion of the magnetic head according to the present invention.

FIG. 28 is a reproduction waveform diagram of the magnetic head according to the present invention.

FIG. 29 is a cross-sectional view showing another example of the ferromagnetic tunnel junction portion of the magnetic head according to the present invention.

30 is a diagram for explaining the operation of the ferromagnetic tunnel junction of the magnetic head shown in FIG.

[Explanation of symbols]

1 slider 21 Ferromagnetic tunnel junction 211 First ferromagnetic film 212 Second ferromagnetic film 210 insulating film 214, 215 magnetic domain control film 216 Magnetization pinned film 22 First electrode film 23 Second electrode film 24, 25 insulating film 13, 14 ABS surface

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Manabu Ota               1-13-1 Nihonbashi, Chuo-ku, Tokyo               DK Corporation (72) Inventor Masashi Sano               1-13-1 Nihonbashi, Chuo-ku, Tokyo               DK Corporation                (56) References Patent 3055662 (JP, B2)

Claims (14)

(57) [Claims] 1. A slider, a first magnetic ceil film, and
A magnetic head including a second magnetic shield film and at least one magnetic conversion element, wherein the first magnetic seed film and the second magnetic shield film are separated from each other on the slider by an insulating distance. The magnetic conversion element includes a ferromagnetic tunnel junction portion and a short-circuit prevention insulating film, and the ferromagnetic tunnel junction portion includes an insulating film, a first ferromagnetic film, and a second ferromagnetic film. A ferromagnetic film, and the first ferromagnetic film and the second ferromagnetic film are laminated via the insulating film,
It is arranged between the first magnetic shield film and the second magnetic shield film, the barrier potential of the insulating film of the ferromagnetic tunnel junction is in the range of 0.5 to 3 eV, and the short circuit is prevented. The insulating film for use is formed between the first ferromagnetic film and the second ferromagnetic film, adjacent to the insulating film, so that a tunnel current flows in a region other than the ferromagnetic tunnel junction. Magnetic head to block. 2. The magnetic head according to claim 1, wherein the insulating film has a barrier potential of 1.5 to
A magnetic head in the range of 2.5 eV. 3. The magnetic head according to claim 1, wherein the coercive force of the first ferromagnetic film and the second
Magnetic head with a different coercive force from the ferromagnetic film of. 4. The magnetic head according to claim 1, wherein the first ferromagnetic film and the second ferromagnetic film are provided.
Of the above magnetic film is antiferromagnetically coupled through the insulating film. 5. The magnetic head according to claim 1, wherein the insulating film is an aluminum oxide film formed by performing a heat treatment at 40 to 100 ° C. in the atmosphere after film formation. head. 6. The magnetic head according to claim 1, wherein the insulating film is a diamond-like carbon film. 7. The magnetic head according to claim 1, wherein a magnetic domain fixed film is provided on either one of the first ferromagnetic film and the second ferromagnetic film. Magnetic head. 8. The magnetic head according to claim 1, wherein the magnetic domain fixing film is a hard ferromagnetic film. 9. The magnetic head according to claim 7, wherein the magnetic domain fixed film is an antiferromagnetic film. 10. The magnetic head according to claim 7, wherein among the first ferromagnetic film and the second ferromagnetic film, the ferromagnetic film not provided with the magnetic domain fixed film is: A magnetic head having magnetic domain control films on both ends. 11. The magnetic head according to claim 10, wherein the magnetic domain fixed film is a hard ferromagnetic film. 12. The magnetic head according to claim 10, wherein the domain fixing film is an antiferromagnetic film, and the first ferromagnetic film or the second ferromagnetic film and the antiferromagnetic film. A magnetic head that causes exchange coupling between magnetic films. 13. The magnetic head according to claim 1, further comprising an induction type magnetic conversion element. 14. The magnetic head according to claim 13, further comprising a first magnetic shield film and a second magnetic shield film, wherein the ferromagnetic tunnel junction section includes the first magnetic shield film. A magnetic head disposed between a shield film and the second magnetic shield film, wherein the second magnetic shield film is a magnetic film provided in the inductive magnetic conversion element.