JP3323098B2 - Magnetoresistance effect multilayer film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magneto-resistance effect multilayer film constituting a magneto-resistance effect element applied to a magnetic head, a position sensor, a rotation sensor and the like.

[0002]

2. Description of the Related Art Conventionally, an AMR (Anisotropic Magnetoresistance) head using an anisotropic magnetoresistance effect phenomenon and a GMR (Gi) using a spin-dependent scattering phenomenon of conduction electrons have been known as a magnetoresistive read head (MR head).
ant Magnetoresistance: a giant magnetoresistive effect) head is known, and as a specific example of a GMR head,
Spin valve (Spin) that shows high magnetoresistance effect in low external magnetic field
-Valve) head is shown in U.S. Pat. No. 5,159,513.

FIG. 4 shows an example of a conventionally known spin valve structure, which has a free ferromagnetic layer 1, a nonmagnetic intermediate layer 2, a pinned ferromagnetic layer 3, and an antiferromagnetic layer. 4 are laminated on a substrate, magnet layers 5 and 5 made of Co-Pt or the like are provided on both sides of the laminate so as to sandwich the laminate, and electrode layers 6 and 6 are provided thereon. FIG.
In order to fix the magnetization direction of the pinned ferromagnetic layer 3 to the Z direction in FIG. 4 in the conventional structure shown in FIG. 1, a relatively large bias magnetic field is required, and the larger the bias magnetic field, the better. In order to overcome the demagnetizing field in the Z direction in FIG. 4 and prevent the magnetization direction from fluctuating due to the magnetic flux from the magnetic medium, a bias magnetic field of at least 100 Oe is required. In order to obtain this bias magnetic field, the conventional structure shown in FIG. 4 utilizes an exchange anisotropic magnetic field generated by providing the antiferromagnetic layer 4 in contact with the pinned ferromagnetic layer 3.

In the structure shown in FIG. 4, a vertical bias in the direction parallel to the film surface (X direction: track direction in FIG. 4) is applied to the free ferromagnetic layer 1 by the magnet layers 5 and 5 to form a single magnetic domain. In the track direction in the state of
The magnetization direction of the pinned ferromagnetic layer 3 is directed in the Z direction in FIG. 4, that is, in the direction perpendicular to the magnetization direction of the free ferromagnetic layer 1, in a single magnetic domain state with a bias applied. Need to be kept. The purpose of the application of the longitudinal bias is to suppress Barkhausen noise caused by the formation of a large number of magnetic domains in the free ferromagnetic layer 1, that is, to achieve a smooth resistance change from the magnetic medium to the magnetic flux with little noise. That's why. Further, the magnetization direction of the pinned ferromagnetic layer 3 must not be changed by the magnetic flux (Z direction in FIG. 4) from the magnetic medium, and the direction of the free ferromagnetic layer 1 is changed to the magnetization direction of the pinned ferromagnetic layer 3. A linear response of the magnetoresistive effect can be obtained by changing the direction within the range of 90 ± θ °. As described above, the linear response is achieved by using the exchange anisotropic magnetic field generated at the contact interface with the antiferromagnetic layer for the bias of the pinned ferromagnetic layer and the longitudinal bias of the free ferromagnetic layer in the spin valve head. Thus, a magnetoresistive head with good performance and reduced Barkhausen noise is realized.

[0005]

In the spin valve structure shown in FIG. 4, the free ferromagnetic layer 1 to which the longitudinal bias is applied by the left and right magnet layers 5, 5 is close to the magnet layers 5, 5. The track end portion (the region denoted by reference numeral 7 in FIG. 4) tends to be a dead region in which the direction of magnetization does not easily change, and a problem arises when the track is further narrowed in accordance with the improvement of the recording density of the magnetic medium. There was a fear.

Therefore, the inventors of the present invention first formed a laminate S comprising a free ferromagnetic layer 1, a nonmagnetic intermediate layer 2, a pinned ferromagnetic layer 3, and an antiferromagnetic layer 4, as shown in FIG. There has been proposed a structure in which a ferromagnetic layer 8 made of Ni—Fe or the like is provided so as to be sandwiched from both sides, and an antiferromagnetic layer 9 and an electrode layer 10 are stacked on the ferromagnetic body 8. According to this structure, the ferromagnetic layer 8 is formed into a single magnetic domain by the unidirectional anisotropy of the antiferromagnetic layer 9, so that the extension 8 of the ferromagnetic layer 8 in contact with the stacked body is formed.
A magnetic flux can be applied to the free ferromagnetic layer 1 from the a side, and a longitudinal bias can be magnetically applied to the free ferromagnetic layer 1 by the exchange interaction.

However, in order to manufacture the stacked structure shown in FIG. 5, after stacking the free ferromagnetic layer 1, the nonmagnetic intermediate layer 2, the pinned ferromagnetic layer 3, and the antiferromagnetic layer 4, the stacked structure S
Is processed by a photolithography technique in which a mask is placed only on the portion to be removed and other unnecessary portions are removed by ion milling, and a laminate S having a width corresponding to the track width is manufactured. There is a high possibility that unnecessary elements are reattached to the peripheral portion of the ferromagnetic layer 8 during ion milling, and the unnecessary elements are mixed in an important portion where a magnetic flux acts at a portion where the extended portion 8a of the ferromagnetic layer 8 and the laminated body S contact. As a result, there is a possibility that the desired effect due to the vertical bias cannot be obtained.

The present invention has been made in view of the above circumstances, and a layer for applying a longitudinal bias to a free ferromagnetic layer is provided not on the side of the free ferromagnetic layer but on the free ferromagnetic layer. As a result, the effect of the longitudinal bias can be sufficiently obtained by eliminating the risk of mixing unnecessary elements at the boundary between the layer for applying the longitudinal bias to the free ferromagnetic layer and the free ferromagnetic layer, and the linear response can be obtained. It is an object of the present invention to provide a magnetoresistive sensor having excellent characteristics and suppressing Barkhausen noise.

[0009]

According to the present invention, a pinned ferromagnetic layer in which magnetization reversal is pinned and a free ferromagnetic layer in which magnetization reversal is free are interposed via a nonmagnetic layer. Magnetoresistance effect multi-layered body provided
A layer film, which is in contact with the non-magnetic layer of the free magnetic layer
On the surface opposite to the surface, a soft magnetic layer is formed to cover this,
The opposite side of the soft magnetic layer from the surface in contact with the free magnetic layer
An antiferromagnetic layer is formed on the surface and
With both sides extended beyond the part corresponding to the rack width
The soft magnetic layer and the antiferromagnetic layer are stacked . Next, in the present invention, the magnetization reversal is pinned.
Pinned ferromagnetic layer and free magnetization reversal
A ferromagnetic layer is laminated via a non-magnetic layer,
Cover the surface of the layer opposite to the surface in contact with the non-magnetic layer.
Forming a soft magnetic layer, and forming a soft magnetic layer on the soft magnetic layer.
The antiferromagnetic layer must not be laminated on the surface opposite to the surface in contact.
Characterized by being provided with a laminate . Further, in the present invention, the soft magnetic layer of the crystalline phase mainly composed of bccFe, Ti, Zr, Hf, V, Nb, Ta, and one or more elemental M 'of the W It is characterized by being mainly composed of fine crystal grains having a crystal phase composed of carbide and nitride and having an average crystal grain size of 30 nm or less.

[0010] In the structure of the present invention, the soft magnetic layer may include b
a crystal phase mainly composed of crystal grains having an average crystal grain size of 30 nm or less containing ccFe as a main component, O, Ti, Zr, Hf,
V, wherein Nb, Ta, W, that of amorphous phase formed of a compound with one or more elemental M of the rare earth elements. The antiferromagnetic layer is a Cr-Al alloy,
It is preferable to be composed of one of a Cr-Ga alloy, a Cr-In alloy, and NiO. Further, when the thickness of the soft magnetic layer is 10
0-300 °, the thickness of the free ferromagnetic layer is 80-90 °,
The total thickness of the antiferromagnetic layer and the free ferromagnetic layer is 200 to
Preferably, it is set to 400 °. Further described above
In the present invention, electrode layers are provided on both sides of the laminate.
Are provided so as to be sandwiched from both sides thereof.
-Cover the top surface of the magnetic layer and the top surfaces of the electrode layers on both sides.
What is characterized in that the soft magnetic layer is formed may be used.
No. In the invention described above, electrodes are provided on both sides of the laminate.
The laminate sandwiches the laminate from both sides thereof, and the laminate
Pinned ferromagnetic layer, nonmagnetic layer and free magnetism
Provided in contact with the layer, the soft magnetic layer and the antiferromagnetic layer
It may be one characterized by that. Further, in the present invention,
Α-Fe ₂ O ₃ , P
Consists of any of t-Mn, IrMn and NiO
9. An antiferromagnetic layer is laminated.
The magnetoresistive effect multilayer film according to any one of the above. In the present invention
Thus, the laminate has a trapezoidal cross section, and the trap of the laminate is
The electrode layer is formed so as to be in contact with the slopes on both sides in the width direction.
It may be a feature characterized by the following.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of a magnetoresistive multilayer film according to the present invention, in which a pinned ferromagnetic layer 31 formed on a substrate constituting a magnetic head or the like (not shown) has a pinned layer. The magnetic layer 32, the nonmagnetic layer 33, and the free ferromagnetic layer 34 are sequentially stacked to form a stacked body 35 having, for example, a trapezoidal cross section, and a gap corresponding to the track width TW is provided on both ends of the free ferromagnetic layer 34. Are provided therebetween, and electrode layers 36, 36 sandwiching the laminated body 35 from both sides thereof are provided. Further, a soft magnetic layer 37 is laminated so as to cover the electrode layers 36 and 36 and the free ferromagnetic layer 34, and the soft magnetic layer 37
An antiferromagnetic layer 38 is laminated thereon so as to cover the soft magnetic layer 37. In this structure, the pinned ferromagnetic layer 31, the pinned ferromagnetic layer 32, the nonmagnetic layer 33, the free ferromagnetic layer 34, the soft magnetic layer 37, and the antiferromagnetic layer 38 form a spin valve type. magnetoresistive multilayer film T ₁ of the is configured.

The pinned ferromagnetic layer 31 increases the coercive force of the ferromagnetic layer 32 by applying a magnetic exchange coupling force to the pinned ferromagnetic layer 32 formed thereon to change the direction of magnetization. The pinning ferromagnetic layer 31 is preferably made of an antiferromagnetic material, particularly an oxide antiferromagnetic material, and as one specific example, α
Formed from -Fe ₂ O _3. If a pinned ferromagnetic layer 31 consisting of the _{α-Fe 2 O 3, α} -Fe 2 O 3 is higher Morin point itself, because of the high blocking temperature, temperature changes in terms of excellent linearity response To provide a magnetoresistive multilayer film that is resistant to noise and can surely suppress Barkhausen noise. Note that, in addition to α-Fe ₂ O ₃ , Pt-Mn, Ir-M
n, Fe-Mn, NiO, etc. can also be used. Each of the ferromagnetic layers 32 and 34 is formed of a ferromagnetic thin film. Specifically, a Ni—Fe alloy, a Co—Fe alloy,
It is made of i-Co alloy, Co, Ni-Fe-Co alloy or the like. Further, the ferromagnetic layer 32 may be composed of a Co layer, the ferromagnetic layer 34 may be composed of a Ni-Fe alloy layer, or may have a laminated structure of a Co layer and a Ni-Fe alloy layer. In the case of a two-layer structure of a Co layer and a Ni—Fe alloy layer, a structure in which a thin Co layer is disposed on the nonmagnetic layer 33 side may be adopted.

This is because the non-magnetic layer 33 is formed of the ferromagnetic layers 32, 3
In the giant magnetoresistance effect generating mechanism with a structure sandwiched by 4,
The effect of the spin-dependent scattering of conduction electrons at the interface between Co and Cu is large, and when the ferromagnetic layers 32 and 34 are made of the same type of material, the spin-dependent scattering of conduction electrons is made higher than when they are made of different types of materials. This is because factors other than scattering are less likely to occur and a higher magnetoresistance effect can be obtained. For this reason, when the ferromagnetic layer 32 is made of Co, a structure in which the nonmagnetic layer 33 side of the ferromagnetic layer 34 is replaced with a Co layer with a predetermined thickness is preferable. Further, even if the Co layer is not particularly provided, the nonmagnetic layer 3 of the ferromagnetic layer 34 can be used.
An alloy state in which more Co is contained on the third side may be used, and a concentration gradient layer may be used in which the Co concentration gradually decreases toward the opposite side.

The non-magnetic layer 33 is made of Cu, Cr, Au,
It is made of a non-magnetic material represented by Ag or the like and has a thickness of 20 to 40 °.
It is formed in the thickness of. Here, if the thickness of the nonmagnetic film 33 is smaller than 20 °, magnetic coupling between the ferromagnetic layers 32 and 34 is likely to occur. The non-magnetic layer 33
Is larger than 40 °, the rate of conduction electrons scattered at the interface between the non-magnetic layer 33 and the ferromagnetic layers 32 and 34, which is a cause of the magnetoresistance effect, is reduced, and the magnetoresistance effect is reduced by the current shunting effect. It is not preferable.

The soft magnetic layer 37 is made of, for example, a soft magnetic alloy film described below, and preferably has a thickness of 100 nm.
It is formed to about 300 °. The soft magnetic layer 37 used here preferably has excellent soft magnetic properties, a high saturation magnetic flux density, and a large specific resistance.

Composition Example 1 The composition formula is represented by Fe _a M _b O _c , where M is a rare earth element (Sc, Y or La, C belonging to Group 3A of the periodic table).
e, Pr, Nd, Pm, Sm, Eu, Gd, Td, D
lanthanoids such as y, Ho, Er, Tm, Yb, and Lu), or a mixture thereof, and the composition ratios a, b, and c are preferably 5% by atom%.
0 ≦ a ≦ 70, 5 ≦ b ≦ 30, 10 ≦ c ≦ 30, a + b
A soft magnetic alloy characterized by satisfying the relationship of + c = 100 can be applied. Incidentally, if the soft magnetic alloy has this composition, the present inventors first disclosed in Japanese Patent Laid-Open No. 06-3167.
No. 48, the specific resistance is 400 to 10
Since it has a high specific resistance of about 00 μΩ · cm, it can be used to achieve the object of the present invention.

[0017] 'indicated by _{e O f, M' Fe d} M as Composition Example 2 composition formula, Ti,
Represents at least one element selected from the group consisting of Zr, Hf, V, Nb, Ta, and W or a mixture thereof, and the composition ratios d, e, and f are preferably atomic%, and 45 ≦ d ≦ 70,
A soft magnetic alloy characterized by satisfying the relationship of ≦ e ≦ 30, 10 ≦ f ≦ 40, and d + e + f = 100 can be applied. In the case of a soft magnetic alloy having this composition, as disclosed by the present inventors in Japanese Patent Application Laid-Open No. 06-316748, the specific resistance is 400 to 2.0 × 10 ⁵ μΩ ·.
Since it shows a high specific resistance of about cm, it can be used for achieving the object of the present invention.

Composition Example 3 The composition formula is represented by T _100-abcd -X _a -M _b -Z _c -Q _d , T is one or both of Fe and Co, and X is Si
And / or Al, M ′ is Ti, Zr, Hf,
At least one element selected from the group consisting of V, Nb, Ta, Mo, and W; Z is one or both of C and N;
Q is Cr, Re, Ru, Rh, Ni, Pd, Pt, Au
Represents at least one element selected from the group consisting of metal elements. In the above composition, it is preferable to satisfy the following composition ratio (atomic%). 0 ≦ a ≦ 25, 1 ≦ b
≦ 7, 0.5 ≦ c ≦ 10, 0 ≦ d ≦ 10. The composition of this example shows a high saturation magnetic flux density exceeding 1 T and can be used to achieve the object of the present invention.

[0019] Composition Example 4 composition _{formula, T 100-efbcd -Si e -Al} f -M b -
Either or both of Z _c -Q _d, where, T is Fe and Co,
M is at least one element selected from the group consisting of metal elements Ti, Zr, Hf, V, Nb, Ta, Mo, and W; Z is one or both of C and N; and Q is Cr, Re, Ru, Rh. ,
It represents at least one element selected from the group consisting of Ni, Pd, Pt, and Au. Further, it is preferable to satisfy the following composition ratio (atomic%). 8 ≦ e ≦ 15, 0.5
≦ f ≦ 10, 1 ≦ b ≦ 7, 0.5 ≦ c ≦ 10, 0 ≦ d ≦
10. The composition of this example shows a high saturation magnetic flux density exceeding 1 T and can be used to achieve the object of the present invention.

Next, the antiferromagnetic layer 38 is made of an antiferromagnetic material different from the pinning ferromagnetic layer 31, for example, Cr-A
1, PtMn, NiO and the like are preferable, and among them, high specific resistance Cr-Al is most preferable.

In the above structure, the free ferromagnetic layer 3
Since the soft magnetic layer 37 is provided on the ferromagnetic layer 4, the free ferromagnetic layer 34 and the soft magnetic layer 37 can be ferromagnetically coupled, whereby the coercive force of the free ferromagnetic layer 34 can be reduced. Further, by providing the antiferromagnetic layer 38 on the soft magnetic layer 37, the soft magnetic layer 37 can be made into a single magnetic domain, and a bias is applied to the free ferromagnetic layer 34 by the soft magnetic layer 37 made into the single magnetic domain. can do. Further, the pinning ferromagnetic layer 31 is in close contact with the entire surface of the pinned ferromagnetic layer 32 to pin the direction of magnetization of the pinned ferromagnetic layer 32 so that the magnetization is directed in the direction b perpendicular to the plane of FIG. The orientation can be aligned. From the above, the free ferromagnetic layer 34
By directing the direction of magnetization of the pinned ferromagnetic layer 32 in the direction of arrow b and the direction of magnetization of the pinned ferromagnetic layer 32 in FIG.

The steady-state current in the structure shown in FIG. 1 is given to a magnetoresistive multilayer film T _1. With the structure shown in FIG. 1, the direction of magnetization of the pinned ferromagnetic layer 32 is pinned, and the direction of magnetization of the free ferromagnetic layer 34 is made free in a region corresponding to the track width TW. A coercive force difference is generated between the magnetic layers 32 and 34, which results in a giant magnetoresistance effect. That is, when an external magnetic field such as a leakage magnetic field from a magnetic recording medium acts on a portion corresponding to the track width TW at the center of the free ferromagnetic layer 34 in which the rotation of the magnetization is made free, the free ferromagnetic layer 34 since the magnetization direction of rotate freely, the resistance changes in the magnetoresistive multilayer film T ₁ is generated with the rotation, it is possible to read the magnetic information in the magnetic recording medium by measuring the change in resistance. In addition, during this resistance change, the free ferromagnetic layer 34 is in contact with the single-domain soft magnetic layer 37 and, since a longitudinal bias is applied thereto, does not generate Barkhausen noise and has a good linear response. A resistance change can be obtained by the property.

In the structure shown in FIG. 1, when the pinning ferromagnetic layer 31 is made of α-Fe ₂ O ₃ ,
₂ O ₃ is originally an oxide, and is superior in corrosion resistance to FeMn used in the conventional spin valve structure, and has a high Neel temperature, so that it is resistant to temperature fluctuation. Although it has been described that the pinning ferromagnetic layer 31 can be made of α-Fe ₂ O _{3 in the} element structure shown in FIG.
The constituent material of the pinning ferromagnetic layer 31 may be any material that increases the coercive force by applying a magnetic exchange coupling force to the pinning ferromagnetic layer 32. Of course, it may be made of an antiferromagnetic material or a high coercive force magnetic material.

Next, in order to obtain the magneto-resistance effect multilayer film T ₁ having the structure shown in FIG. 1, a non-magnetic ceramic substrate such as Al ₂ O ₃ —TiC (altic) is applied to a high-frequency magnetron sputtering apparatus or an ion beam sputtering apparatus. It can be formed by installing the device in a chamber of the apparatus, forming an atmosphere of an inert gas such as Ar gas in the chamber, and then sequentially forming necessary layers. Targets necessary for film formation include, for example, an α-Fe ₂ O ₃ target, a Ni—Fe alloy target, and a Cu target.

In order to manufacture a magnetoresistive multilayer film having a cross-sectional structure shown in FIG. 1, α is applied to a substrate by sputtering while applying a magnetic field in the Z direction of FIG. 1 in a reduced pressure atmosphere such as an Ar gas pressure of 3 mTorr or less. Forming a pinned ferromagnetic layer 31 made of -Fe ₂ O _3, and forming two ferromagnetic layers 32 and 34 on the pinned ferromagnetic layer 31 with a nonmagnetic layer 33 interposed therebetween; The photolithography process and ion milling are performed to remove the remaining portion except for a portion corresponding to the track width, thereby forming a stacked body 35. When the laminate 35 is formed, the electrode layers 36 are sandwiched between both sides of the laminate 35,
The soft magnetic layer 37 and the antiferromagnetic layer 38 are stacked so as to cover the upper surface of the multilayer body 35 and the upper surface of the electrode layer 36. Here, when stacking the antiferromagnetic layer 38, the antiferromagnetic layer 38 is formed, for example, while applying a magnetic field.

Next, a magnetic field is applied in a direction perpendicular to the plane of FIG. 1 to magnetize the pinned ferromagnetic layer 31 and fix the magnetization direction, thereby pinning the magnetization direction of the pinned ferromagnetic layer 32. . By the above processing, a magnetoresistive sensor having a structure shown in FIG. 3 in which the magnetization direction of the pinned ferromagnetic layer 32 and the magnetization direction of the free ferromagnetic layer 34 are orthogonal to each other by 90 ° can be obtained.

Here, in the photolithography process for forming the laminate 35, necessary films are laminated, and a mask covering the portion where the laminate is to be formed is put on the laminated film, and unnecessary portions are removed by ion milling. A process for forming the laminate 35 is performed. Here, it is conceivable that an unnecessary substance is mixed into the side of the laminate 35 during ion milling. However, with the structure shown in FIG. 1, the soft magnetic layer 37 formed on the free ferromagnetic layer 34 and the antiferromagnetic layer 3
8 applies a longitudinal bias to the free ferromagnetic layer 34,
Only the electrode layer 36 may be provided on the side of the free ferromagnetic layer 34, and the incorporation of unnecessary elements on the side of the stacked body 35 has no adverse effect on the magnetoresistance effect. Therefore, even if the ion milling process is performed, there is no adverse effect on the vertical bias applying mechanism.

[0028] Next Fig. 2 shows a second embodiment of the magnetoresistive multilayer film according to the present invention, the magnetoresistive multilayer film T ₂ of the this embodiment, pin the stack 40 of trapezoidal section Ferromagnetic layer 31, pinned ferromagnetic layer 32, nonmagnetic layer 33, free ferromagnetic layer 34, soft magnetic layer 37 ', and antiferromagnetic layer 3
8 ′, and the electrode layers 36 are provided so as to cover both sides of the laminate 40.

FIG. 3 shows a third embodiment of the magnetoresistive multilayer film according to the present invention. The magnetoresistive multilayer film T ₂ of this embodiment comprises a soft magnetic layer 37 and an antiferromagnetic layer 38. Are formed on a substrate as an underlayer, and a free ferromagnetic layer 34, a nonmagnetic layer 33, a pinned ferromagnetic layer 32, and a pinning ferromagnetic layer 31 are laminated thereon so as to have a trapezoidal cross section. To form a laminated body 41, and the electrode layers 36, 36 are provided on the soft magnetic layer 37 so as to cover both sides of the laminated body 41.

In any of these structures, since the soft magnetic layer 37 and the antiferromagnetic layer 38 are laminated on the free ferromagnetic layer 34, a longitudinal bias can be applied, and the soft magnetic layer 37 Since the layer 38 is arranged in close contact, the soft magnetic layer 37 can be made into a single magnetic domain, and the object of the present invention can be achieved in the same manner as in the above embodiment.

The structure shown in FIG. 2 is different from the structure shown in FIG.
1; a pinned ferromagnetic layer 32; a nonmagnetic layer 33; a free ferromagnetic layer 34; a soft magnetic layer 37 '; and an antiferromagnetic layer 38'. It can be manufactured by forming the layered body 40 by performing ion milling collectively after the films are laminated and forming the electrode layers 36 and 36. That is, after forming the laminate 35 and the electrode layer 36 as in the structure shown in FIG. 1, the soft magnetic layer 37 and the antiferromagnetic layer 3 are further formed.
2 is not necessary in the structure shown in FIG. 2, so that the structure shown in FIG. 2 can reduce the number of steps compared to the structure shown in FIG. 1 and can be easily manufactured.

[0032]

As described above, in the present invention, a soft magnetic layer and an antiferromagnetic layer are laminated on a free ferromagnetic layer, and magnetic exchange coupling is generated from the antiferromagnetic layer to the soft magnetic layer. The soft magnetic layer can be made into a single magnetic domain, and a longitudinal bias can be applied from the antiferromagnetic layer to the free ferromagnetic layer via the soft magnetic layer. Since the soft magnetic layer and the antiferromagnetic layer are provided so as to be stacked so as to cover the upper surface of the free ferromagnetic layer , even when the films constituting each layer are stacked and patterned by ion milling, etc. There is no possibility that an unnecessary substance is mixed into the lamination interface between the layer, the antiferromagnetic layer, and the free ferromagnetic layer, and a desired longitudinal bias can be applied.
Therefore, if the magnetoresistive effect multilayer film having the above structure is used for a magnetic head, a change in resistance occurs in a linear response to a small magnetic field from a magnetic recording medium, whereby the magnetic information can be detected with good detection sensitivity and without Barkhausen noise. A magnetic head capable of performing reading can be provided. Also, in the previous configuration
According to the description, the soft magnetic layer provided on the free magnetic layer
Since the ground is applied, it is necessary to provide the electrode layer on both sides of the laminate.
And the laminate is patterned by ion milling.
Even if the electrode layer is formed by
Of unnecessary elements on the side has no effect on the magnetoresistance effect of the laminate
The magnetoresistive multilayer film as intended.
Obtainable.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of a magnetoresistive multilayer film according to the present invention.

FIG. 2 is a sectional view showing a second embodiment of the magnetoresistive effect multilayer film according to the present invention.

FIG. 3 is a sectional view showing a third embodiment of the magnetoresistive effect multilayer film according to the present invention.

FIG. 4 is a cross-sectional view showing a first example of a conventional magnetoresistive sensor.

FIG. 5 is a sectional view showing a second example of a conventional magnetoresistive sensor.

[Explanation of symbols]

T ₁ , T ₂ , T ₃ Magnetoresistance multilayer film 31 Pinned ferromagnetic layer 32 Pinned ferromagnetic layer 33 Nonmagnetic layer 34 Free ferromagnetic layer 35 Stack 36 Electrode layer 37, 37 ', 47 Soft magnetic layer 38, 38 ', 48 Antiferromagnetic layer

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-8-287426 (JP, A) JP-A-9-23031 (JP, A) JP-A-6-316748 (JP, A) JP-A 9-230 92904 (JP, A) JP-A-6-314617 (JP, A) JP-A-8-279117 (JP, A) JP-A-9-91628 (JP, A) JP-A-9-16923 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) H01L 43/08 G01R 33/09 G11B 5/39 H01F 10/32 JICST file (JOIS)

Claims (10)

(57) [Claims] 1. A magnetoresistive multilayer film comprising a laminated body in which a pinned ferromagnetic layer whose magnetization reversal is pinned and a free ferromagnetic layer whose magnetization reversal is freed are laminated via a nonmagnetic layer. A soft magnetic layer is formed to cover the surface of the free magnetic layer opposite to the surface in contact with the nonmagnetic layer, and the soft magnetic layer is opposite to the surface of the soft magnetic layer in contact with the free magnetic layer. The soft magnetic layer and the antiferromagnetic layer are stacked in a state where an antiferromagnetic layer is stacked on the surface of the layer and extended to both sides from a portion corresponding to the track width of the stacked body. And a magnetoresistive effect multilayer film. 2. A pinned ferromagnetic layer in which magnetization reversal is pinned and a free ferromagnetic layer in which magnetization reversal is freed are laminated via a nonmagnetic layer, and are in contact with the nonmagnetic layer of the free magnetic layer. A soft magnetic layer is formed so as to cover the surface opposite to the surface where the soft magnetic layer is formed, and an antiferromagnetic layer is stacked on the surface of the soft magnetic layer opposite to the surface in contact with the free magnetic layer. A magnetoresistive effect multilayer film, comprising: 3. The soft magnetic layer according to claim 1, wherein the soft magnetic layer comprises a crystal phase mainly composed of bccFe, Ti, Zr, Hf, V, Nb, Ta, and W.
And a crystal phase composed of carbides and nitrides with one or more of the elements M ′ having an average crystal grain size of 30 nm.
3. The magnetoresistive multilayer film according to claim 1, wherein the following fine crystal grains are mainly used. 4. The soft magnetic layer according to claim 1, wherein said soft magnetic layer comprises bcc Fe as a main component, a crystal phase mainly composed of crystal grains having an average crystal grain size of 30 nm or less, O, Ti, Zr, Hf, V, Nb, Ta,
3. The magnetoresistive multilayer film according to claim 1, comprising W and an amorphous phase composed of a compound with one or more of the rare earth elements M. 5. The antiferromagnetic layer is formed of a Cr—Al alloy,
The magnetoresistive multilayer film according to claim 1, comprising one of a Cr—Ga-based alloy, a Cr—In-based alloy, and NiO. 6. The soft magnetic layer has a thickness of 100 to 300.
3. The magnetoresistive element according to claim 1, wherein the thickness of the free ferromagnetic layer is 80 to 90 degrees, and the total thickness of the antiferromagnetic layer and the free ferromagnetic layer is 200 to 400 degrees. Effect multilayer film. 7. An electrode layer is provided on both sides of the laminate so as to sandwich the laminate from both sides, and the soft layer is formed so as to cover the upper surface of the free magnetic layer of the laminate and the upper surfaces of the electrode layers on both sides thereof. 2. The magnetoresistive multilayer film according to claim 1, wherein a magnetic layer is formed. 8. A laminated ferromagnetic layer, a non-magnetic layer, a free magnetic layer, and a soft magnetic layer such that an electrode layer sandwiches the laminated body from both sides thereof, and which constitutes the laminated body. The magnetoresistive multilayer film according to claim 2, wherein the magnetoresistance effect multilayer film is provided so as to be in contact with the antiferromagnetic layer. 9. The semiconductor device according to claim 6, wherein α is in contact with said pinned ferromagnetic layer.
_{-Fe 2 O 3, Pt-Mn} , IrMn, magnetoresistive multilayer film according to any one of claims 1 to 8 antiferromagnetic layer made of any one of NiO is characterized in that it is laminated. 10. The laminate according to claim 1, wherein the laminate has a trapezoidal cross section, and an electrode layer is formed so as to be in contact with slopes on both sides in the track width direction of the laminate. The magnetoresistive effect multilayer film as described in the above .