JP3420152B2 - Magnetoresistive head and magnetic recording / reproducing device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ferromagnetic tunnel type magnetoresistive head for reproducing magnetically recorded information, and a high-density magnetic head provided with the ferromagnetic tunnel type magnetoresistive head as a magnetic reproducing head. The present invention relates to a recording / reproducing device.

[0002]

2. Description of the Related Art A giant magnetoresistive (GMR) element has been proposed for a reproducing portion of a magnetic head used in a high density magnetic recording / reproducing apparatus, one of which is a structure called a spin valve film. It is described in Japanese Patent No. 358310. Further, as a magnetic head reproducing unit compatible with further high density magnetic recording in the future, a ferromagnetic tunnel type magnetoresistive (TMR) element having a higher output than a GMR element has been proposed, which is disclosed in Japanese Patent Laid-Open No. 10-4227. Describes a magnetic head using a TMR element.

However, in the conventional TMR element, there is a limit to the magnitude of the magnetoresistive effect, and the higher output T
In order to realize the MR element, a magnetoresistive effect element having a new function is required. As one of the means, there is application of a material having a higher spin polarization than the ferromagnetic material used in the conventional TMR element. Euro Physics Letters Vol. 39, pages 545-549 (EUROPHYSICS LETTERS, 39
(5), pp545-549 (1997)), a TMR element (La _0.7 Sr _0.3 MnO ₃ / SrTiO ₃ ) using a high spin polarization material.
/ La _0.7 Sr _0.3 MnO ₃ ) is described.

[0004]

However, when the high spin polarization material is directly used in the magnetic sensing part of the TMR element as described above, the resistance of the element is extremely high, i.e., mega ohm or more, and it is used as a magnetic head. Sometimes it causes noise and is not suitable. Further, in order to realize a magnetic recording / reproducing device having a sufficiently high recording density, it is necessary to realize a ferromagnetic tunnel type magnetoresistive effect element having a higher output than the conventional structure.

An object of the present invention is to provide a ferromagnetic tunnel type magnetoresistive element having a higher output than the conventional structure. Another object of the present invention is to provide a magnetoresistive effect magnetic head and a magnetic recording / reproducing apparatus using the ferromagnetic tunnel magnetoresistive effect element.

[0006]

[Means for Solving the Problems] Spin polarization of electrons
(P) is an electron with different rotation (rotation) directions (clockwise and left).
(A clockwise rotation is a downward spin, a counterclockwise rotation is an upward spin)
Is generally understood by the difference in the number of (density of states). example
For example, spin polarization P = 0.8 means that upward spins are downward spins.
9 times more than In addition, the magnetism of the TMR element
The resistance effect (TMR ratio) is 2P using this polarization ratio P.₁
P₂/ (1-P₁P₂) Can be expressed as (P ₁Is TMR
Spin polarization of the ferromagnetic free layer of the device, P₂Is a TMR element
Spin polarization of the ferromagnetic pinned layer). Therefore, high TMR
In order to obtain the ratio, a high spin polarization material with a large P is used.
Semi-metal ferromagnet (Fe₃O_Four, CrO₂Etc.)
And are valid. Electrical conductivity of these semi-metallic ferromagnets
The responsible electron is not a free electron, but the energy level is split
Fermi, which is an electron in the d orbital band and mainly responsible for conduction
The state of the electron near the energy is the charge in either direction.
There are many electrons, that is, highly spin-polarized electrons.

In the present invention, the semi-metal ferromagnetic layer is adjacent to the TMR element, and a current is passed from the semi-metal ferromagnetic layer (highly polarized spin injection layer) to the TMR element side to obtain highly spin-polarized electrons. To the TMR element to increase the spin polarization P ₁ of the ferromagnetic free layer in the definition of the TMR ratio,
Enhances the magnetoresistive effect. The highly-polarized spin injection layer is provided with one current introduction terminal, and current is passed through the TM.
It is introduced into the R element. On the other hand, the magnetoresistive effect of the TMR element is the rate of resistance change between the ferromagnetic free layer and the ferromagnetic pinned layer, as in the conventional case. By adopting such a configuration, the electric resistance of the highly polarized spin injection layer does not contribute to the electric resistance of the TMR element, and it is possible to avoid the increase in resistance which causes noise in application of the magnetic head.

That is, the magnetoresistive effect head according to the present invention is a magnetoresistive effect head having a magnetoresistive effect film and an electrode for flowing a current in the film thickness direction of the magnetoresistive effect film. Magnetic free layer, insulating barrier layer,
A ferromagnetic tunnel magnetoresistive film including a ferromagnetic pinned layer and an antiferromagnetic layer, characterized in that a highly polarized spin injection layer is provided adjacent to a ferromagnetic free layer.

The magnetoresistive effect head according to the present invention is also a magnetoresistive effect head having a magnetoresistive effect film and an electrode for flowing a current in the film thickness direction of the magnetoresistive effect film, wherein the magnetoresistive effect film is strong. A ferromagnetic tunnel type magnetoresistive film including a magnetic free layer, an insulating barrier layer, a ferromagnetic fixed layer and an antiferromagnetic layer, in which a highly polarized spin injection layer is adjacent to a ferromagnetic free layer via an insulating layer. It is characterized by being provided.

The magnetoresistive effect head according to the present invention is also a magnetoresistive effect head provided with a magnetoresistive effect film and an electrode for flowing a current in the film thickness direction of the magnetoresistive effect film, wherein the magnetoresistive effect film is strong. A ferromagnetic tunnel type magnetoresistive film including a magnetic free layer, an insulating barrier layer, a ferromagnetic fixed layer and an antiferromagnetic layer, in which a highly polarized spin injection layer includes an insulating layer and a non-magnetic intermediate layer in the ferromagnetic free layer. It is characterized in that they are provided adjacent to each other. As for the insulating layer and the non-magnetic intermediate layer, the insulating layer may be provided on the highly polarized spin injection layer side, or the non-magnetic intermediate layer may be provided on the highly polarized spin injection layer side. Alternatively,
The insulating layer and the non-magnetic intermediate layer may be provided so that the insulating layer is sandwiched between two non-magnetic intermediate layers.

The highly polarized spin injection layer is preferably formed on the orientation control film. Here, the highly polarized spin injection layer is F
It may be an oxide or compound containing e, Co or Mn. Insulating layer is Al, Mg, Ti, Ta, H
It can be composed of an oxide or compound containing at least one of f, Nb, Mo, Cr, Ga or As. The orientation control film is made of Ni, Zr, Zn, Al, M.
g, Ti, Ta, Hf, Nb, Mo, Cr or Co
An oxide or compound containing at least one of the above can be used.

A magnetic recording / reproducing apparatus according to the present invention comprises a magnetic recording medium, a recording medium driving means for driving the magnetic recording medium, a magnetic head having a recording portion and a reproducing portion, and a magnetic head driving means for driving the magnetic head. In a magnetic recording / reproducing apparatus including and, the above-mentioned magnetoresistive head is used as a reproducing unit of the magnetic head.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. [Embodiment 1] FIG. 1 is a schematic sectional view showing a first configuration example of a ferromagnetic tunnel magnetoresistive effect element according to the present invention.

A highly polarized spin injection layer 11 is formed on a substrate 50, and a ferromagnetic tunnel magnetoresistive (TMR) element 1 is arranged adjacent to the highly polarized spin injection layer 11. The TMR element 1 includes a ferromagnetic free layer 12 and an insulating barrier layer 1 in this order from the substrate side.
3. The ferromagnetic pinned layer 14 and the antiferromagnetic layer 15 are laminated, and the in-plane magnetizations of the ferromagnetic free layer 12 and the ferromagnetic pinned layer 14 are inclined by about 90 ° with respect to each other when no external magnetic field is applied. It is turned to the direction. The magnetization of the ferromagnetic free layer 12 is freely rotated by the external magnetic field (H), and the electric resistance in the direction perpendicular to the film surface is changed according to the rotation angle to generate the magnetoresistive effect. An interlayer insulating layer 25 is formed at the end of the TMR element 1 in order to prevent electrical leakage between the ferromagnetic free layer 12 and the ferromagnetic fixed layer 14.

The electrode 21 is on the antiferromagnetic layer 15, the electrode 22 is on the ferromagnetic free layer 12, and the electrode 24 is the highly polarized spin injection layer 1.
1 is provided on each of the electrodes 1, a current is passed between the electrodes 21 and 22, and the rate of change in resistance between them is used as the output of the TMR element 1.
Separately from this, by passing a current from the electrode 24 to the electrode 21, the highly spin-polarized conduction electrons flow from the highly polarized spin injection layer 11 into the TMR element 1.

Next, a method of manufacturing the magnetoresistive effect sensor and various materials will be described. Fe ₃ O ₄ , which is the highly polarized spin injection layer 11, is formed on the Si substrate 50 to a thickness of 50 nm by rf sputtering, and patterned into a predetermined shape. Next, a photoresist is applied, and a lift-off pattern is formed into a prescribed shape by using photolithography, and then CoFe, which is the ferromagnetic free layer 12, is added with 5%.
1 nm of Al for forming the insulating barrier layer 13 is formed. This metallic Al was naturally oxidized for 20 minutes in an oxygen atmosphere of 10 Torr. After that, CoFe of the ferromagnetic pinned layer 14 is 2 nm and IrMn of the antiferromagnetic layer 15 is 8 n.
m and Ta, which is the protective film 23, are sequentially stacked to a thickness of 5 nm by rf sputtering and lifted off. afterwards,
The junction is patterned up to the ferromagnetic free layer 12 by using photolithography and ion milling. The area of the produced joint is 5 × 5 (μm ² ). Next, SiO ₂ that is the interlayer insulating layer 25 is formed to a thickness of 15 nm, and the resist is lifted off. After that, a photoresist pattern for arranging the Au electrodes 22 and 24 by photolithography and ion milling is formed, and then the Au electrode 5 is formed.
nm by rf sputtering to form the electrode 21 in a predetermined shape and the electrode 22 on the ferromagnetic free layer 12.
4 is processed so as to be arranged on the highly polarized spin injection layer 11 to manufacture a magnetoresistive effect sensor.

Here, the results obtained in the TMR element having the above-mentioned highly polarized spin injection layer will be described. Above TMR
A current flowing in the element 1, that is, a current flowing between the electrode 22 and the electrode 21 is _ITMR (A), and a current flowing from the highly polarized spin injection layer 11 into the TMR element 1, that is, the electrode 24 to the electrode 21.
_Let I _inj (A) be the current flowing through I _TMR / I _inj = 1
At that time, when the resistance change rate of the TMR element 1 was measured, a TMR ratio of 55% at maximum was observed at room temperature.

The MR ratio of the ferromagnetic tunnel magnetoresistive effect, spin polarization of the ferromagnetic free layer 12 (P _1), the following using the spin polarization of the ferromagnetic pinned layer 14 (P ₂₎ [ Equation 1] is given.

[0019]

[Equation 1]

Co is used for the ferromagnetic free layer 12 and the ferromagnetic pinned layer.
When Fe is used, the spin polarization of CoFe is P ₁ = P ₂ =
Since it is 0.34, the TMR ratio is 26%. That is, the TMR ratio without the highly polarized spin injection layer 11 is 2
6%. Therefore, by injecting highly spin-polarized electrons from the highly-polarized spin injection layer 11 into the TMR element 1 as in the present embodiment, the TMR ratio can be increased twice or more.

In this embodiment, CoFe is used for the ferromagnetic free layer 12 and the ferromagnetic pinned layer 14 of the TMR element 1, but
Multilayer film of NiFe or CoFe and NiFe (CoF
e / NiFe) or CoFe / Ru / CoFe may be used. Further, although a natural oxide film of Al is used for the insulating barrier layer 13 in the present embodiment, the method of oxidizing Al may be plasma forced oxidation or direct deposition of Al ₂ O ₃ .
The material of the insulating barrier layer 13 is MgO, SrTiO ₃ ,
It may be HfO ₂ , TaO, NbO or MoO.

Further, as the highly polarized spin injection layer,
Sr ₂ FeMoO ₇ , La _0.7 Sr _0.3 MnO ₃ , MnS
Almost the same results were obtained using b and CrO _2, and the TMR ratio when using each material was 53%, 51%, 4
It was 5% and 55%.

[Embodiment 2] FIG. 2 is a schematic sectional view showing a second configuration example of the ferromagnetic tunnel magnetoresistive effect element according to the present invention. The structure shown in FIG. 2 corresponds to the structure shown in FIG. 1 in which an insulating layer 111 is provided between the highly polarized spin injection layer 11 and the ferromagnetic free layer 12.

MgO was used for the insulating layer 111 and its thickness was set to 2 nm. The element manufacturing process is the same as that of the first embodiment, and the electrode arrangement and the method of measuring the resistance change rate are the same as those of the first embodiment.

Highly polarized spin injection layer 11 to TMR element 1
Injection of highly spin-polarized electrons into the insulating layer 111 exceeds the barrier energy of the insulating layer 111 and is due to tunnel conduction. By the means, only the electrons near the Fermi energy flow into the TMR element side, that is, the direction of the injected spin can be selected.
As a result, the number of electrons that do not contribute to TMR can be reduced and the efficiency of TMR can be improved. The direction of the injected spin is the upward spin in the same direction as the majority spin of CoFe in the ferromagnetic layer 12. As a result, the number of electrons having an upward state increases, and the spin polarization rate of electrons contributing to TMR increases.

FIG. 14 shows the element of the present embodiment,
The current flowing from the electrode 22 to the electrode 21 is I _TMR , and the current flowing from the electrode 24 to the electrode 21 is I _inj , and the ratio I _inj / I
It is a plot of TMR ratio to _TMR. The TMR ratio obtained in this embodiment is 60% (I _inj / I
_TMR = 1), which is larger than that in the first embodiment.

[Third Embodiment] FIG. 3 is a schematic sectional view showing a third configuration example of the ferromagnetic tunnel magnetoresistive effect element according to the present invention. The structure shown in FIG. 3 corresponds to the structure shown in FIG. 2 in which the nonmagnetic intermediate layer 112 is provided between the insulating layer 111 and the ferromagnetic free layer 12.

Cu was used for the non-magnetic intermediate layer 112, and its thickness was set to 2 nm. The nonmagnetic intermediate layer 112 can effectively extend the spin diffusion length of electrons, has a function of suppressing scattering of highly polarized spin electrons, and at the same time prevents diffusion of oxygen from the insulating layer 111 to the TMR element 1 and highly polarized spin injection. The reduction of the effect can be suppressed and the TMR ratio can be increased.

The element manufacturing process is the same as that of the first embodiment, and the electrode arrangement and the method of measuring the resistance change rate are the same as those of the first embodiment. TMR obtained in the present embodiment
The ratio was 52%. The same effect is obtained by the non-magnetic intermediate layer 11
2 has high conductivity instead of Cu Au, Pd, A
It was also observed when g and Al were used.

[Fourth Embodiment] FIG. 4 is a schematic sectional view showing a fourth structural example of the ferromagnetic tunnel magnetoresistive effect element according to the present invention. The structure shown in FIG. 4 corresponds to the structure shown in FIG. 2 in which the nonmagnetic intermediate layer 112 is provided between the insulating layer 111 and the highly polarized spin injection layer 11.

Cu was used for the non-magnetic intermediate layer 112, and its thickness was set to 2 nm. The nonmagnetic intermediate layer 112 can effectively extend the spin diffusion length of electrons, has a function of suppressing the scattering of highly polarized spin electrons, and at the same time prevents diffusion of oxygen from the insulating layer 111 to the highly polarized spin injection layer 11 and enhances it. The reduction of the polarized spin injection effect can be suppressed, and the TMR ratio can be increased.

The element manufacturing process is the same as that of the first embodiment, and the electrode arrangement and the method of measuring the resistance change rate are also the same as those of the first embodiment. TMR obtained in the present embodiment
The ratio was 50%. The same effect is obtained by the non-magnetic intermediate layer 11
2 has high conductivity instead of Cu Au, Pd, A
It was also observed when g and Al were used.

[Fifth Embodiment] FIG. 5 is a schematic sectional view showing a fifth configuration example of the ferromagnetic tunnel magnetoresistive effect element according to the present invention. The structure shown in FIG. 5 has a non-magnetic intermediate layer 112 between the ferromagnetic free layer 12 and the insulating layer 111 and a non-magnetic intermediate layer between the insulating layer 111 and the highly polarized spin injection layer 11 in the structure shown in FIG. Corresponding to the one with layer 114.

Cu was used for the non-magnetic intermediate layer 112, and its thickness was set to 2 nm. The non-magnetic intermediate layer 112 can effectively extend the spin diffusion length of electrons and has a function of suppressing the scattering of highly polarized spin electrons, and at the same time, prevents the oxygen from the insulating layer 111 to the TMR element 1 and the highly polarized spin injection layer 11. It is possible to prevent the diffusion and suppress the reduction of the highly polarized spin injection effect.
The ratio can be increased.

The element manufacturing process is the same as that of the first embodiment, and the electrode arrangement and the method of measuring the resistance change rate are the same as those of the first embodiment. TMR obtained in the present embodiment
The ratio was also 51%. The same effect is obtained by using Au, Pd, which has high conductivity, as the non-magnetic intermediate layer 112 instead of Cu.
It was also observed in Ag and Al.

[Sixth Embodiment] FIG. 6 is a schematic cross-sectional view showing a sixth configuration example of the ferromagnetic tunnel magnetoresistive effect element according to the present invention. The structure shown in FIG. 6 corresponds to the structure shown in FIG. 1 in which the orientation control film 20 is provided between the substrate 50 and the highly polarized spin injection layer.

The orientation control film 20 was made of NiO and had a thickness of 50 nm. The orientation control film 20 has magnetic anisotropy by orienting the film of the highly polarized spin injection layer 11 to control a magnetic domain and improve magnetic characteristics. Further, by providing a specific Fermi surface of the highly polarized spin injection layer 11 at the interface with the ferromagnetic layer 12, highly polarized electrons with a large number of upward spins can flow to the TMR element side. it can.

The element manufacturing process is the same as that of the first embodiment, and the electrode arrangement and the method of measuring the resistance change rate are the same as those of the first embodiment. TMR obtained in the present embodiment
The ratio was 62%.

[Embodiment 7] FIG. 7 is a schematic sectional view showing a seventh configuration example of the ferromagnetic tunnel magnetoresistive effect element according to the present invention. The configuration shown in FIG. 7 corresponds to the configuration shown in FIG. 2 in which the orientation control film 20 is provided between the substrate 50 and the highly polarized spin injection layer.

The orientation control film 20 was made of NiO and had a thickness of 50 nm. The orientation control film 20 has magnetic anisotropy by orienting the film of the highly polarized spin injection layer 11 to control a magnetic domain and improve magnetic characteristics. Further, by providing a specific Fermi surface of the highly polarized spin injection layer 11 at the interface with the ferromagnetic layer 12, highly polarized electrons with a large number of upward spins can flow to the TMR element side. it can.

The element manufacturing process is the same as that of the first embodiment, and the electrode arrangement and the method of measuring the resistance change rate are the same as those of the first embodiment. FIG. 15 shows that in the element of this embodiment, the current flowing from the electrode 22 to the electrode 21 is I _TMR ,
The current flowing from 4 to the electrode 21 is I _inj , and the ratio I _inj /
It is a plot of TMR ratio to I _TMR. The TMR ratio obtained in this embodiment is 65% (I _inj /
I _TMR = 1), which is larger than that in the first embodiment.

[Embodiment 8] FIG. 8 is a schematic sectional view showing an eighth configuration example of the ferromagnetic tunnel magnetoresistive effect element according to the present invention. The structure shown in FIG. 8 corresponds to the structure shown in FIG. 3 in which the orientation control film 20 is provided between the substrate 50 and the highly polarized spin injection layer.

The orientation control film 20 was made of NiO and had a thickness of 50 nm. The orientation control film 20 has magnetic anisotropy by orienting the film of the highly polarized spin injection layer 11 to control a magnetic domain and improve magnetic characteristics. Further, by providing a specific Fermi surface of the highly polarized spin injection layer 11 at the interface with the ferromagnetic layer 12, highly polarized electrons with a large number of upward spins can flow to the TMR element side. it can.

The element manufacturing process is the same as that of the first embodiment, and the electrode arrangement and the method of measuring the resistance change rate are the same as those of the first embodiment. TMR obtained in the present embodiment
The ratio was 55%.

[Ninth Embodiment] FIG. 9 is a schematic cross-sectional view showing a ninth configuration example of the ferromagnetic tunnel magnetoresistive effect element according to the present invention. The structure shown in FIG. 9 corresponds to the structure shown in FIG. 4 in which the orientation control film 20 is provided between the substrate 50 and the highly polarized spin injection layer 11.

The orientation control film 20 was made of NiO and had a thickness of 50 nm. The orientation control film 20 has magnetic anisotropy by orienting the film of the highly polarized spin injection layer 11 to control a magnetic domain and improve magnetic characteristics. Further, by providing a specific Fermi surface of the highly polarized spin injection layer 11 at the interface with the ferromagnetic layer 12, highly polarized electrons with a large number of upward spins can flow to the TMR element side. it can.

The element manufacturing process is the same as that of the first embodiment, and the electrode arrangement and the method of measuring the resistance change rate are the same as those of the first embodiment. TMR obtained in the present embodiment
The ratio was 56%.

[Embodiment 10] FIG. 10 is a schematic sectional view showing a tenth structural example of a ferromagnetic tunnel magnetoresistive effect element according to the present invention. The configuration shown in FIG.
This structure corresponds to a structure in which the orientation control film 20 is provided between the substrate 50 and the highly polarized spin injection layer.

The orientation control film 20 was made of NiO and had a thickness of 50 nm. The orientation control film 20 has magnetic anisotropy by orienting the film of the highly polarized spin injection layer 11 to control a magnetic domain and improve magnetic characteristics. Further, by providing a specific Fermi surface of the highly polarized spin injection layer 11 at the interface with the ferromagnetic layer 12, highly polarized electrons with a large number of upward spins can flow to the TMR element side. it can.

The element manufacturing process is the same as that of the first embodiment, and the electrode arrangement and the method of measuring the resistance change rate are also the same as those of the first embodiment. TMR obtained in the present embodiment
The ratio was 55%.

[Embodiment 11] FIG. 11 is a conceptual diagram of a magnetic head equipped with a magnetic sensor having a highly polarized spin injection TMR element of the present invention. A highly polarized spin injection TMR element 10, an electrode (Au) 40, a lower shield (NiFe) 35 of 100 nm, an upper shield / lower core (NiFe) 36 of 1 μm, a coil 42, and an upper core (CoNiFe) 83 are formed on a substrate 50. Formed, and the facing surface 63 is formed.

FIG. 12 is a conceptual diagram of the vicinity of the magnetic head and the magnetic recording medium in the magnetic recording / reproducing apparatus using the magnetic head of the present invention. Base 50 that also functions as head slider 90
A highly polarized spin injection TMR element 10 and an electrode 40 are formed on the magnetic recording medium, and a magnetic head made of these is positioned on a recording track 44 of a magnetic recording medium 91 to perform reproduction. The head slider 90 moves relative to the recording medium 91 while facing the facing surface 63 and flying or contacting the height of 0.1 μm or less. By this mechanism, the magnetoresistive laminated film 10 transfers the magnetic signal recorded on the recording medium 91 to the recording medium 91.
Can be read from the stray magnetic field 64.

FIG. 13 is a schematic diagram showing a structural example of a magnetic recording / reproducing apparatus according to the present invention. A recording medium 91 for magnetically recording information is rotated by a spindle motor 93,
The actuator 92 guides the head slider 90 onto the track of the recording medium 91. That is, in the magnetic disk device, the reproducing head and the recording head formed on the head slider 90 relatively move close to a predetermined recording position on the recording medium 91 by this mechanism and sequentially write and read signals. .

The actuator 92 may be a rotary actuator. The recording signal is a signal processing system 94.
Through the recording head, the recording is performed on the medium and the output of the reproducing head is obtained through the signal processing system 94. Furthermore, when moving the playback head to the desired recording track,
The position on the track can be detected by using the highly sensitive output from the reproducing head, and the actuator can be controlled to position the head slider.

Although one head slider 90 and one recording medium 91 are shown in this drawing, they may be plural. The recording medium 91 may have recording media on both sides to record information. When information is recorded on the disc screen, the head sliders 90 are arranged on both sides of the disc.

A magnetic recording / reproducing apparatus equipped with a ferromagnetic tunnel type magnetoresistive effect sensor having the above-mentioned highly polarized spin injection layer is suitable for high density as compared with a magnetic recording / reproducing apparatus equipped with a conventional sensor. It showed various characteristics.

[0057]

According to the present invention, by providing a highly polarized spin injection layer adjacent to a TMR element and injecting highly spin polarized electrons into the TMR element, a ferromagnetic material having a higher output than that of a conventional TMR element can be obtained. A tunnel type magnetoresistive effect element can be provided. As a result, it is possible to obtain a magnetic head and a high-density magnetic recording / reproducing apparatus having good reproduction output and stability.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing a first configuration example of a ferromagnetic tunnel magnetoresistive effect element according to the present invention.

FIG. 2 is a schematic sectional view showing a second configuration example of the ferromagnetic tunnel magnetoresistive effect element according to the present invention.

FIG. 3 is a schematic sectional view showing a third configuration example of the ferromagnetic tunnel magnetoresistive effect element according to the present invention.

FIG. 4 is a schematic sectional view showing a fourth configuration example of the ferromagnetic tunnel magnetoresistive effect element according to the present invention.

FIG. 5 is a schematic sectional view showing a fifth configuration example of the ferromagnetic tunnel magnetoresistive effect element according to the present invention.

FIG. 6 is a schematic sectional view showing a sixth configuration example of the ferromagnetic tunnel magnetoresistive effect element according to the present invention.

FIG. 7 is a schematic sectional view showing a seventh configuration example of the ferromagnetic tunnel magnetoresistive effect element according to the present invention.

FIG. 8 is a schematic sectional view showing an eighth configuration example of the ferromagnetic tunnel magnetoresistive effect element according to the present invention.

FIG. 9 is a schematic sectional view showing a ninth configuration example of the ferromagnetic tunnel magnetoresistive effect element according to the present invention.

FIG. 10 is a schematic sectional view showing a tenth configuration example of the ferromagnetic tunnel magnetoresistive effect element according to the present invention.

FIG. 11 is a conceptual perspective view showing an example of a recording / reproducing head using the ferromagnetic tunnel type magnetoresistive effect element of the present invention.

FIG. 12 is a conceptual diagram in the vicinity of a magnetic head and a magnetic recording medium in a magnetic recording / reproducing apparatus using the magnetic head of the present invention.

FIG. 13 is a diagram showing a configuration example of a magnetic recording / reproducing apparatus according to the present invention.

FIG. 14 is a diagram in which the TMR ratio is plotted against the current ratio I _inj / I _TMR .

FIG. 15 is a diagram in which the TMR ratio is plotted against the current ratio I _inj / I _TMR .

[Explanation of symbols]

1 ... Ferromagnetic tunnel type magnetoresistive (TMR) element, 1
0 ... Highly polarized spin injection TMR element, 11 ... Highly polarized spin injection layer, 12 ... Ferromagnetic free layer, 13 ... Insulation barrier layer, 14
... ferromagnetic pinned layer, 15 ... antiferromagnetic layer, 20 ... orientation control film, 21 ... electrode, 22 ... electrode, 23 ... protective film, 24 ... electrode, 25 ... interlayer insulating layer, 50 ... substrate, 111 ... insulating layer ,
112 ... Non-magnetic intermediate layer, 114 ... Non-magnetic intermediate layer, 35 ...
Lower shield, 36 ... Upper shield and lower core, 40 ...
Electrical terminals, 41 ... Coil, 50 ... Base, 63 ... Opposing surface,
64 ... Leakage magnetic field from recording medium, 83 ... Upper core, 90
... slider, 91 ... recording medium, 92 ... actuator, 93 ... spindle motor, 94 ... signal processing circuit

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP 2001-94173 (JP, A) JP 2001-94172 (JP, A) JP 10-206513 (JP, A) JP 10-209526 ( JP, A) Tokuheihei 8-504303 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G11B 5/39

Claims (5)

(57) [Claims] 1. A magnetoresistive effect head comprising a magnetoresistive effect film and an electrode for passing a current in a film thickness direction of the magnetoresistive effect film, wherein the magnetoresistive effect film is a ferromagnetic free layer, an insulating barrier layer, A magnetoresistance effect film including a ferromagnetic pinned layer and an antiferromagnetic layer, characterized in that a highly polarized spin injection layer is provided adjacent to the ferromagnetic free layer. head. 2. A magnetoresistive effect head comprising a magnetoresistive effect film and an electrode for passing a current in the film thickness direction of the magnetoresistive effect film, wherein the magnetoresistive effect film is a ferromagnetic free layer, an insulating barrier layer, A ferromagnetic tunnel type magnetoresistive film including a ferromagnetic fixed layer and an antiferromagnetic layer, characterized in that a highly polarized spin injection layer is provided adjacent to the ferromagnetic free layer via an insulating layer. And a magnetoresistive effect head. 3. A magnetoresistive effect head comprising a magnetoresistive effect film and an electrode for passing a current in a film thickness direction of the magnetoresistive effect film, wherein the magnetoresistive effect film is a ferromagnetic free layer, an insulating barrier layer, A ferromagnetic tunnel type magnetoresistive film including a ferromagnetic pinned layer and an antiferromagnetic layer, wherein a highly polarized spin injection layer is provided adjacent to the ferromagnetic free layer via an insulating layer and a nonmagnetic intermediate layer. A magnetoresistive effect head characterized in that 4. The magnetoresistive effect head according to claim 1, wherein the highly polarized spin injection layer is formed on an orientation control film. 5. A magnetic recording device comprising: a magnetic recording medium; a recording medium driving unit for driving the magnetic recording medium; a magnetic head having a recording unit and a reproducing unit; and a magnetic head driving unit for driving the magnetic head. A reproducing apparatus, wherein the magnetoresistive effect head according to any one of claims 1 to 4 is used as a reproducing unit of the magnetic head.