JP2001209911A - Spin valve type thin film magnetic element, thin film magnetic head, floating magnetic head, and manufacturing method of spin valve type thin film magnetic element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the spin valve type thin film magnetic element capable of reducing asymmetry (Asymmetry). SOLUTION: In the spin valve type thin film magnetic element 11, the first and the second fixed magnetic layers 21 and 51 are disposed at the both sides of the thickness direction of a free magnetic layer 41, the free magnetic layer 41 consists of the first and the second ferromagnetic free layers 42 and 43, and the entire part is in a ferromagnetic state, the first fixed magnetic layer 21 consists of the first and the second ferromagnetic pinned layers 22 and 23, and the entire part is in the ferromagnetic state, the second fixed magnetic layer 51 consists of the third and the fourth ferromagnetic pinned layers 52 and 53, and the entire part is in the ferromagnetic state, and the magnetizing direction of the second ferromagnetic pinned layer 23 close to the free magnetic layer 41 and the magnetizing direction of the ferromagnetic third pinned layer 52 close to the free magnetic layer 41 are anti-parallel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spin-valve thin-film magnetic element, a thin-film magnetic head, a floating magnetic head, and a method of manufacturing a spin-valve thin-film magnetic element, and more particularly to a method for reducing asymmetry. The present invention relates to a spin-valve thin-film magnetic element capable of performing the above-described operations.

[0002]

2. Description of the Related Art G provided with an element exhibiting a giant magnetoresistance effect
An MR (Giant Magnetoresistive) head has a multilayer structure in which elements exhibiting a magnetoresistance effect are formed by laminating a plurality of materials. There are several types of structures that produce the giant magnetoresistance effect. A spin-valve thin-film magnetic element has a relatively simple structure and a high rate of change in resistance to a weak external magnetic field. The spin valve thin film magnetic element includes a single spin valve thin film magnetic element and a dual spin valve thin film magnetic element.

FIGS. 15 and 16 are schematic cross-sectional views of a conventional spin-valve thin film element. FIG. 15 is a schematic cross-sectional view as viewed from the recording medium side, and FIG. 16 is a schematic cross-sectional view as viewed from the track width direction. 15 and 16, the X1 direction is the track width direction of the spin-valve thin film magnetic element, the Y direction is the direction of the leakage magnetic field from the magnetic recording medium, and the Z direction is the direction of the magnetic recording medium. The direction of movement.

The spin-valve thin-film magnetic element 13 shown in FIGS. 15 and 16 has a nonmagnetic conductive layer, a pinned magnetic layer, and an antiferromagnetic layer laminated on both sides of a free magnetic layer in the thickness direction. It is a so-called dual spin valve thin film magnetic element.

The spin-valve thin-film magnetic element 13 has
An underlayer 115 is laminated on the insulating layer 264, and on this underlayer 115, the second antiferromagnetic layer 172, the second pinned magnetic layer 1
51, a second nonmagnetic conductive layer 132, a free magnetic layer 141,
The first nonmagnetic conductive layer 131, the first pinned magnetic layer 121, the first
The antiferromagnetic layer 171 and the cap layer 114 are sequentially laminated. The conductive layers 116 and 116, the intermediate layers 117 and 117, and the bias layer 1 are provided on both sides in the X1 direction of the stack including the base layer 115 and the cap layer 114 in the drawing.
18 and 118 and bias underlayers 119 and 119 are formed.

The first and second pinned magnetic layers 121 and 151 are
Magnetized by an exchange anisotropic magnetic field developed at each interface with the first and second antiferromagnetic layers 171 and 172,
These magnetization directions are fixed in the illustrated Y direction. Further, the free magnetic layer 141 includes the bias layers 118, 118.
And the magnetization direction thereof is opposite to the X1 direction in the drawing, that is, the first and second pinned magnetic layers 121 and 15.
1 are aligned in the cross direction of the magnetization directions. The single magnetic domain of the free magnetic layer 141 prevents Barkhausen noise.

In this spin-valve thin-film magnetic element 13, the free magnetic layer 14 is separated from the conductive layers 116, 116.
1, the first and second nonmagnetic conductive layers 131 and 132 and the first
A detection current is applied to the second pinned magnetic layers 121 and 151,
When a leakage magnetic field from the magnetic recording medium running in the Z direction is applied to the free magnetic layer 141 along the Y direction in the figure, the magnetization direction of the free magnetic layer 141 changes from the opposite direction to the X1 direction to Y direction.
It fluctuates in the direction. The change in the magnetization direction in the free magnetic layer 141 and the first and second pinned magnetic layers 121 and 151
The electrical resistance changes in relation to the magnetization direction of the magnetic recording medium, and a leakage magnetic field from the magnetic recording medium is detected by a voltage change based on the resistance change.

[0008]

Generally, in a spin-valve thin-film magnetic element, as shown in FIG. 17, when the external magnetic field from the recording medium is not applied, the magnetization direction H ₃ of the free magnetic layer 141 and the first , Second pinned magnetic layer 1
Ideally, the magnetization directions H ₁ and H _{2 of} 21 and 151 are orthogonal to each other. However, in the conventional spin-valve thin-film magnetic element 13, the first and second non-magnetic conductive layers 13
The first and second fixed magnetic layers 121 and 151 and the free magnetic layer 141 are coupled to each other via the ferromagnetic interlayer via the first and second fixed magnetic layers 121 and 132, and magnetic field moments H ₄ and H ₅ are generated by the ferromagnetic interlayer coupling magnetic field. . These magnetic field moments H ₄ , H ₅
Is parallel to the magnetization directions of the first and second pinned magnetic layers 121 and 151, respectively, and is the illustrated Y direction.

Therefore, the magnetization direction H of the free magnetic layer 141
_ThreeIs the above magnetic field moment H_Four, H _FiveIs shown in the Y direction
Tilted to H₆And the magnetic properties of the free magnetic layer 141
Direction H₆Of the first and second pinned magnetic layers 121 and 151
Direction H₁, H_TwoCan no longer be orthogonalized,
Asymmetry of raw waveform, that is, asymmetry
There was a problem that it became large.

The present invention has been made in view of the above circumstances, and has been made to prevent the magnetization direction of the free magnetic layer from being inclined.
Spin-valve thin-film magnetic element capable of reducing asymmetry, thin-film magnetic head having this spin-valve thin-film magnetic element, floating magnetic head having this thin-film magnetic head, and spin-valve thin-film magnetic element It is an object of the present invention to provide a method for producing the same.

[0011]

In order to achieve the above object, the present invention employs the following constitution. The spin-valve thin-film magnetic element of the present invention includes a nonmagnetic conductive layer, a fixed magnetic layer, and an antiferromagnetic layer sequentially laminated on both sides in the thickness direction of the free magnetic layer. A non-magnetic conductive layer, a pair of conductive layers for applying a detection current to the pair of fixed magnetic layers, and a pair of bias layers for aligning the magnetization direction of the free magnetic layer; L is an integer of 1 or more) and a non-magnetic intermediate layer inserted between these ferromagnetic layers and a non-magnetic intermediate layer are stacked, and the magnetization directions of the adjacent ferromagnetic layers are opposite to each other. It is parallel and the whole is in a ferrimagnetic state, and one of the fixed magnetic layers is 2M (where M is 1).
A ferromagnetic layer having a thickness equal to or greater than the integer above and a nonmagnetic layer inserted between these ferromagnetic layers are laminated, and the magnetization directions of the adjacent ferromagnetic layers are set to be antiparallel. The whole is in a ferrimagnetic state, and the magnetization direction of the one fixed magnetic layer is fixed in a direction crossing the magnetization direction of the entire free magnetic layer by an exchange coupling magnetic field with the adjacent one of the antiferromagnetic layers. And the other fixed magnetic layer is 2N
(Where N is an integer of 1 or more) ferromagnetic layers and a nonmagnetic layer inserted between these ferromagnetic layers are stacked, and the magnetization directions of the adjacent ferromagnetic layers are antiparallel. The entire pinned magnetic layer is brought into a ferrimagnetic state, and the magnetization direction of the other pinned magnetic layer is parallel to the magnetization direction of the one pinned magnetic layer due to the exchange coupling magnetic field with the adjacent one of the antiferromagnetic layers. The magnetization direction of the ferromagnetic layer closest to the free magnetic layer among the ferromagnetic layers constituting the one fixed magnetic layer, and the most free magnetic layer among the ferromagnetic layers constituting the other fixed magnetic layer. The magnetization direction of the ferromagnetic layer close to the layer is antiparallel.

According to such a spin-valve thin-film magnetic element, one fixed magnetic layer is composed of an even number of 2L ferromagnetic layers, and the other fixed magnetic layer is composed of an even number of 2N ferromagnetic layers. Since the magnetization directions of the pinned magnetic layers are made parallel and the magnetization direction of the ferromagnetic layer closest to the free magnetic layer among the ferromagnetic layers constituting each pinned magnetic layer is made antiparallel, The magnetization direction can be aligned with the direction perpendicular to the magnetization direction of the fixed magnetic layer. Although the magnetization direction of the free magnetic layer is normally aligned in one direction by the bias layer, the magnetization direction may be inclined by the magnetization of the fixed magnetic layer sandwiching the free magnetic layer, and the asymmetry may not be reduced. Therefore, according to the spin-valve thin-film magnetic element, the magnetization direction of the free magnetic layer is hardly affected by the magnetization of the fixed magnetic layer, and the asymmetry can be reduced.

A spin-valve thin-film magnetic element according to the present invention is the spin-valve thin-film magnetic element described above, and is closest to the free magnetic layer among the ferromagnetic layers constituting the one fixed magnetic layer. The direction of the magnetic field moment Hb1 of the ferromagnetic exchange coupling magnetic field generated by the ferromagnetic layer and the free magnetic layer being coupled with the ferromagnetic interlayer, and the direction of the most free magnetic layer among the ferromagnetic layers constituting the other fixed magnetic layer. The magnetic moment Hb2 of the ferromagnetic exchange coupling magnetic field generated by the ferromagnetic interlayer coupling between the close ferromagnetic layer and the free magnetic layer
Is antiparallel to the direction of the free magnetic layer.

According to the spin-valve thin-film magnetic element, the magnetic field of the ferromagnetic interlayer coupling magnetic field generated between the free magnetic layer and each of the ferromagnetic layers constituting the one and the other fixed magnetic layers and near the free magnetic layer Since the directions of the moments Hb1 and Hb2 are antiparallel in the free magnetic layer, the coupling magnetic field between the ferromagnetic layers is canceled out, and the magnetization direction of the free magnetic layer is not tilted by the coupling magnetic field between the ferromagnetic layers. By aligning the magnetization direction of the spin-valve thin-film magnetic element with the magnetization direction perpendicular to the magnetization direction of the fixed magnetic layer, the asymmetry of the spin-valve thin-film magnetic element can be reduced.

In the spin-valve thin-film magnetic element of the present invention, the L is 1, the M is 1, and the N
Is preferably 1. When the spin-valve thin-film magnetic element is configured as described above, the thicknesses of the free magnetic layer and the pinned magnetic layer are reduced, and the shunt of the detection current is prevented, so that the magnetoresistance ratio can be increased.

Further, in the spin-valve thin-film magnetic element of the present invention, the one fixed magnetic layer is inserted between the first and second ferromagnetic layers and between the first and second ferromagnetic layers. And a first non-magnetic layer to be formed is laminated, and a film thickness of the second ferromagnetic layer located near the free magnetic layer is larger than a film thickness of the first ferromagnetic layer. The other fixed magnetic layer is formed by laminating third and fourth ferromagnetic layers and a second non-magnetic layer inserted between the third and fourth ferromagnetic layers. The thickness of the third ferromagnetic layer located near the free magnetic layer is preferably smaller than the thickness of the fourth ferromagnetic layer.

Further, in the spin-valve thin-film magnetic element of the present invention, the one fixed magnetic layer is inserted between the first and second ferromagnetic layers and between the first and second ferromagnetic layers. And a first non-magnetic layer to be formed is laminated, and the thickness of the second ferromagnetic layer located near the free magnetic layer is smaller than the thickness of the first ferromagnetic layer. The other fixed magnetic layer is formed by laminating third and fourth ferromagnetic layers and a second non-magnetic layer inserted between the third and fourth ferromagnetic layers. The thickness of the third ferromagnetic layer located near the free magnetic layer may be larger than the thickness of the fourth ferromagnetic layer.

A thin-film magnetic head according to the present invention is a thin-film magnetic head capable of reading magnetic information, comprising the above-mentioned spin-valve thin-film magnetic element. A flying magnetic head according to the present invention includes the above-described thin film magnetic head provided on a slider.

Since the thin-film magnetic head and the flying magnetic head are provided with the above-described spin-valve thin-film magnetic element having a small asymmetry, they are excellent in the symmetry of the reproduction waveform and reduce the frequency of errors during reproduction. It becomes possible.

According to the method of manufacturing a spin-valve thin film magnetic element of the present invention, one of an antiferromagnetic layer, a ferromagnetic layer of 2M (M is an integer of 1 or more) or more which is antiferromagnetically coupled, and 2L (L is an integer of 1 or more) antiferromagnetically coupled to one fixed magnetic layer formed by laminating a nonmagnetic layer inserted between ferromagnetic layers and one nonmagnetic conductive layer 2N (provided that it is antiferromagnetically coupled to the free magnetic layer formed by laminating the above ferromagnetic layer and the nonmagnetic intermediate layer inserted between these ferromagnetic layers and the other nonmagnetic conductive layer) N is 1
(An integer greater than or equal to) and a non-magnetic layer interposed between the ferromagnetic layers and the other fixed magnetic layer formed by laminating the other fixed magnetic layer and the other antiferromagnetic layer. Constitute
The ferromagnetic layers constituting the one fixed magnetic layer and the other fixed magnetic layer, respectively, are subjected to a heat treatment while applying an external magnetic field smaller than a magnetic field that causes a spin-flop transition to the stacked body, and An exchange coupling magnetic field is generated between a layer and the one fixed magnetic layer and between the other antiferromagnetic layer and the other fixed magnetic layer. The magnitude of the external magnetic field is 8.0 × 10 ⁴ A / m
The following is preferred.

According to this method of manufacturing a spin-valve thin-film magnetic element, the free magnetic layer, the pinned magnetic layer, the non-magnetic conductive layer and the antiferromagnetic layer having the above-described structure are laminated to form a pinned magnetic layer. The above-described spin-valve thin-film magnetic element can be easily manufactured only by performing heat treatment while applying an external magnetic field smaller than the magnetic field at which the magnetic layer undergoes spin-flop transition.

[0022]

FIG. 1 is a block diagram showing an embodiment of the present invention.
This will be described with reference to FIGS. 1 to 15, the Z direction in the drawing is the moving direction of the magnetic recording medium, the Y direction in the drawing is the direction of the leakage magnetic field from the magnetic recording medium,
The illustrated X1 direction is the track width direction of the spin-valve thin film magnetic element.

(First Embodiment) FIG. 1 shows a first embodiment of the present invention.
FIG. 2 is a schematic cross-sectional view of the spin-valve thin-film magnetic element 11 according to the embodiment viewed from the magnetic recording medium side. FIG. 2 is a schematic cross-sectional view of the spin-valve thin-film magnetic element 11 viewed from the track width direction. FIG. 3 shows a flying magnetic head 150 provided with the thin-film magnetic head 1 having the spin-valve thin-film magnetic element 11, and FIG. 4 shows a cross-sectional view of a main part of the thin-film magnetic head 1.

A flying magnetic head 150 according to the present invention shown in FIG. 3 has a slider 151 and an end face 1 of the slider 151.
The thin-film magnetic head 1 and the inductive head h according to the present invention provided in 51d are mainly constituted.
Reference numeral 155 indicates a leading side, which is an upstream side of the slider 151 in the moving direction of the magnetic recording medium, and reference numeral 156.
Indicates the trailing side. Rails 151a, 151a, and 151 are provided on the medium facing surface 152 of the slider 151.
b is formed, and an air groove 15 is provided between the rails.
1c and 151c.

As shown in FIG. 4, the thin-film magnetic head 1 according to the present invention is laminated on the insulating layer 162 formed on the end surface 151d of the slider 151.
A lower shield layer 163 laminated thereon, a lower insulating layer 164 laminated on the lower shield layer 163, and a spin-valve thin film according to the present invention formed on the lower insulating layer 164 and exposed on the medium facing surface 152. A magnetic element 11, an upper insulating layer 166 covering the spin-valve thin-film magnetic element 11,
And an upper shield layer 167 that covers the upper insulating layer 166. The upper shield layer 167 is also used as a lower core layer of the inductive head h described later.

The inductive head h includes a lower core layer (upper shield layer) 167, a gap layer 174 laminated on the lower core layer 167, a coil 176, and a coil 1
And an upper core layer 178 joined to the gap layer 174 and joined to the lower core layer 167 on the coil 176 side. The coil 176 is patterned so as to be spiral in a plane. Further, a base end portion 178b of the upper core layer 178 is magnetically connected to the lower core layer 167 at a substantially central portion of the coil 176. Also, the upper core layer 178 includes
A core protection layer 179 made of alumina or the like is laminated.

As shown in FIGS. 1 and 2, the spin-valve thin-film magnetic element 11 of the present invention has a nonmagnetic conductive layer, a pinned magnetic layer, and an antiferromagnetic layer on both sides in the thickness direction of the free magnetic layer. Is a so-called dual spin-valve thin-film magnetic element in which layers are stacked one by one. In this dual spin-valve thin-film magnetic element, since there are two combinations of three layers of free magnetic layer / non-magnetic conductive layer / pinned magnetic layer, three layers of free magnetic layer / non-magnetic conductive layer / pinned magnetic layer are provided. Is higher than that of a single spin-valve thin-film magnetic element in which one combination is used, and it is possible to cope with high-density recording.

In FIG. 1, reference numeral 164 denotes a lower insulating layer formed of Al ₂ O ₃ or the like, and reference numeral 15 denotes an underlayer made of Ta (tantalum) or the like laminated on the lower insulating layer 164. On this underlayer 15, the second antiferromagnetic layer 72, the second pinned magnetic layer 51, the second nonmagnetic conductive layer 3
2. A free magnetic layer 41, a first nonmagnetic conductive layer 31, a first fixed magnetic layer 21, a first antiferromagnetic layer 71, and a cap layer 14 formed of Ta and the like are sequentially stacked. In this manner, the respective layers from the base layer 15 to the cap layer 14 are sequentially laminated to form a laminated body 11A having a width corresponding to the track width and having a substantially trapezoidal cross section.

[0029] shown X ₁ direction on both sides of the laminate 11A is for example, a Co-Pt (cobalt - platinum) pair of bias layer made of an alloy 18, 18 are formed. Bias layer 1
8 and 18 are formed so as to ride on both side surfaces of the stacked body 11A from above the lower insulating layer 164. The bias layers 18 align the magnetization directions of the free magnetic layer 41 to reduce Barkhausen noise of the free magnetic layer 41. The conductive layers indicated by reference numerals 16 and 16 are bias layers 1
It is stacked above 8,18. The conductive layers 16, 1
6 mainly applies a detection current to the free magnetic layer 41, the first and second nonmagnetic conductive layers 31 and 32, and the first and second fixed magnetic layers 21 and 51.

Between the bias layer 18 and the lower insulating layer 164 and between the bias layer 18 and the stacked body 11A,
For example, bias underlayer 1 made of Cr which is a non-magnetic metal
9 are provided. Crystal structure is body-centered cubic structure (bcc
By forming the bias layer 18 on the bias underlayer 19 made of Cr having a structure, the coercive force and the squareness of the bias layer 18 are increased, and the bias magnetic field necessary for forming the free magnetic layer 41 into a single magnetic domain is increased. Can be done.

Further, an intermediate layer 17 made of, for example, Ta or Cr, which is a nonmagnetic metal, is provided between the bias layer 18 and the conductive layer 16. Cr as the conductive layer 16
In the case where is used, by providing the Ta intermediate layer 17, it functions as a diffusion barrier against a heat process such as resist curing in a later step, and it is possible to prevent the magnetic characteristics of the bias layer 18 from deteriorating. Further, Ta is used as the conductive layer 16.
In the case where is used, by providing the intermediate layer 17 of Cr, there is an effect that the crystal of Ta deposited on Cr is easily made into a body-centered cubic structure having a lower resistance.

The first and second antiferromagnetic layers 71 and 72 are made of Pt.
It is preferable to be formed of a Mn alloy. The PtMn alloy is made of NiM which has been conventionally used as an antiferromagnetic layer.
It has better corrosion resistance than n alloys and FeMn alloys, and has a high blocking temperature and a large exchange coupling magnetic field. The first and second antiferromagnetic layers 71 and 72 are each made of X-Mn (where X represents one element selected from Pt, Pd, Ru, Ir, Rh, and Os). Or X'-Pt-Mn (where X 'is P
d, Cr, Ni, Ru, Ir, Rh, Os, Au, Ag
Represents one or more elements selected from the above. ) May be formed of an alloy represented by the formula:

In the PtMn alloy and the alloy represented by the formula X-Mn, Pt or X is 37 to 63
It is desirable to be in the range of atomic%. More preferably,
The range is 44 to 57 atomic%. Furthermore, X'-P
In the alloy represented by the formula of t-Mn, X ′ + Pt is 3
It is desirable to be in the range of 7 to 63 atomic%. More preferably, it is in the range of 44 to 57 atomic%.

The first and second antiferromagnetic layers 71 and 72 are made of an alloy having an appropriate composition range as described above, and are subjected to a heat treatment in a magnetic field to generate a first and second exchange coupling magnetic fields.
The second antiferromagnetic layers 71 and 72 can be obtained. In particular, a PtMn alloy has an exchange coupling magnetic field exceeding 6.4 × 10 ⁴ A / m, and has a very high blocking temperature of 653 K (380 ° C.) at which the exchange coupling magnetic field is lost. Ferromagnetic layers 71 and 72 can be obtained.

As shown in FIGS. 1 and 2, the free magnetic layer 41 includes a first ferromagnetic free layer (ferromagnetic layer) 42 and a second ferromagnetic free layer (ferromagnetic layer) 43, A non-magnetic intermediate layer 44 inserted between the two ferromagnetic free layers 42 and 43 is laminated.

The first and second ferromagnetic free layers 42 and 43 are made of Ni.
Preferably, the nonmagnetic intermediate layer 44 is made of an Fe alloy.
Is preferably formed of a nonmagnetic material made of one or more of Ru, Rh, Ir, Cr, Re, and Cu, or an alloy thereof, and is particularly preferably formed of Ru. The thickness t _f1 of the first ferromagnetic free layer 42 is preferably in the range of 1 to 4 nm, and the thickness t _f2 of the second ferromagnetic free layer 43 is 1
A range of ４4 nm is preferred. Then, the non-magnetic intermediate layer 44
Is preferably in the range of 0.3 to 1.2 nm.

The magnetization direction of the first ferromagnetic free layer 42 is aligned in the X1 direction by the bias magnetic field from the bias layers 18, 18, and the second ferromagnetic free layer 43 is anti-strong with respect to the first ferromagnetic free layer 42. Magnetically coupled and its magnetization direction is shown in X
Aligned in one direction. Therefore, the magnetization directions of the first ferromagnetic free layer 42 and the second ferromagnetic free layer 43 adjacent to each other via the nonmagnetic intermediate layer 44 are antiparallel, and the first ferromagnetic free layer 42 and the second ferromagnetic free layer 42 are adjacent to each other. The free layer 43 is antiferromagnetically coupled.

In order to bring the free magnetic layer 41 into a ferrimagnetic state, it is preferable that the magnitude of the magnetic moment due to the magnetization of the first and second ferromagnetic free layers 42 and 43 be slightly different. In order to make the magnitude of the magnetic moment different, for example, when the first and second ferromagnetic free layers 42 and 43 are made of the same material, it is better to make t _f1 and t _f2 slightly different. In the present embodiment, it is assumed that t _f1 > t _f2 .
When the first and second ferromagnetic free layers 42 and 43 are made of different materials, the saturation magnetizations of the first and second ferromagnetic free layers 42 and 43 are set to M _f1 and M _f2 , respectively. When the magnetic film thicknesses of the first ferromagnetic free layer 42 and the second ferromagnetic free layer 43 are respectively M _f1 · t _f1 and M _f2 · t _f2 ,
_It is good to make _f1 · t _f1 slightly different from M _f2 · t _f2 .

Since the magnetization directions of the first and second ferromagnetic free layers 42 and 43 are antiparallel to each other, the magnetic moments of the first and second ferromagnetic free layers 42 and 43 cancel each other. Since the free magnetic layer 41 is configured so that t _f1 > t _f2 , the magnetization (magnetic moment) of the first ferromagnetic free layer 42 slightly remains, and the magnetization direction of the entire free magnetic layer 41 is changed to X in the figure. Aligned in _one direction.

As described above, in the free magnetic layer 41, the first ferromagnetic free layer 42 and the second ferromagnetic free layer 43 are antiferromagnetically coupled, and the magnetization of the first ferromagnetic free layer 42 remains. The artificial ferrimagnetic state (synthetic ferri fr
ee; Synthetic Ferifree). The free magnetic layer 41 in the ferrimagnetic state can be rotated in accordance with the direction of the external magnetic field even by a small external magnetic field.

The free magnetic layer 4 shown in FIGS.
Reference numeral 1 denotes two ferromagnetic layers (first and second ferromagnetic free layers 42, 4
3), but is not limited thereto.
(Where L is an integer of 1 or more) or more. In this case, a nonmagnetic intermediate layer is inserted between these ferromagnetic layers, respectively, and the magnetization directions of the adjacent ferromagnetic layers are made antiparallel, so that the whole is in a ferrimagnetic state. Is preferred. In order to prevent the shunt of the detection current, L = 1 may be set as in the present embodiment.

The first and second ferromagnetic free layers 42 and 43
May be configured by laminating a diffusion prevention layer and a ferromagnetic base layer, respectively. In this case, it is preferable that each diffusion prevention layer is in contact with the first and second nonmagnetic conductive layers, and each ferromagnetic base layer is in contact with the nonmagnetic intermediate layer. In this case, the diffusion prevention layer is preferably made of Co, and the first and second ferromagnetic base layers are preferably made of a NiFe alloy. By laminating the diffusion preventing layers, mutual diffusion between the first and second nonmagnetic conductive layers 31 and 32 and the first and second ferromagnetic base layers is prevented, and the first and second nonmagnetic conductive layers 31 are prevented. , 32 and the first,
Disturbance of each interface of the second ferromagnetic free layers 2 and 43 can be prevented.

The first and second nonmagnetic conductive layers 31 and 32 are layers that reduce the ferromagnetic interlayer coupling between the free magnetic layer 41 and the first and second fixed magnetic layers 21 and 51 and that mainly allow a detection current to flow. It is preferable to be formed from a conductive non-magnetic material represented by Cu, Cr, Au, Ag and the like, and particularly preferable to be formed from Cu.

The first pinned magnetic layer 21 includes a first ferromagnetic pinned layer (ferromagnetic layer) 22 and a second ferromagnetic pinned layer (ferromagnetic layer) 23, and first and second ferromagnetic pinned layers 22 and 23. And a first nonmagnetic layer (nonmagnetic layer) 24 inserted between them. The first ferromagnetic pinned layer 22 includes a first
The second ferromagnetic pinned layer 23 is provided closer to the first antiferromagnetic layer 71 than the nonmagnetic layer 24 and in contact with the first antiferromagnetic layer 71.
The first nonmagnetic layer 24 is provided closer to the first nonmagnetic conductive layer 31 than the first nonmagnetic layer 24 and is in contact with the first nonmagnetic conductive layer 31.

The first and second ferromagnetic pinned layers 22 and 23 are
It is formed of a NiFe alloy, Co, CoNiFe alloy, CoFe alloy, CoNi alloy, or the like, and is particularly preferably formed of Co. In addition, the first and second
The ferromagnetic pinned layers 22, 23 are preferably formed of the same material. The first nonmagnetic layer 24 is made of Ru, Rh,
It is preferably made of one of Ir, Cr, Re, and Cu or an alloy thereof, and particularly preferably made of Ru. The thickness t _p1 of the first ferromagnetic pinned layer 22 is preferably in the range of 1 to 3 nm,
Is preferably in the range of 1 to ₂ nm, and is preferably thicker than the first ferromagnetic pinned layer 22. Also, the first
The thickness of the nonmagnetic layer 24 is preferably in the range of 0.3 to 1.2 nm.

The magnetization direction of the first ferromagnetic pinned layer 22 is fixed in the illustrated Y direction by an exchange coupling magnetic field with the first antiferromagnetic layer 71, and the second ferromagnetic pinned layer 23 is 22, and its magnetization direction is Y
It is fixed in the opposite direction. Accordingly, the magnetization directions of the first ferromagnetic pinned layer 22 and the second ferromagnetic pinned layer 23 are made antiparallel, and the first and second ferromagnetic pinned layers 2
2, 23 are antiferromagnetically coupled.

In order to bring the first pinned magnetic layer 21 into a ferrimagnetic state, the first and second ferromagnetic pinned layers 22 and 23 are provided.
It is preferable that the magnitudes of the magnetic moments caused by the magnetizations be slightly different from each other. For example, when the first and second ferromagnetic pinned layers 22 and 23 are made of the same material, t
_It is good to make _p1 and _tp2 slightly different. In the present embodiment, it is assumed that t _p2 > t _p1 . If the first and second ferromagnetic pinned layers 22 and 23 are made of different materials,
The saturation magnetization of the second ferromagnetic pinned layers 22 and 23 is set to M
_p1, and M _p2, first, when the magnetic thickness of the second ferromagnetic pinned layer 22 and _{M p1 · t p1, M p2} · t p2 respectively, M _p1 · t _p1 and M _p2 · t _It is good to make _p2 slightly different.

Since the magnetization directions of the first and second ferromagnetic pinned layers 22 and 23 are antiparallel to each other, the magnetic moments of the first and second ferromagnetic pinned layers 22 and 23 are in a mutually canceling relationship. However, if the first pinned magnetic layer 21 has t _p2 > t
Since it is configured to be _p1 , the magnetization (magnetic moment) of the second ferromagnetic pinned layer 23 slightly remains. This residual magnetization is further amplified by the exchange coupling magnetic field with the first antiferromagnetic layer 71, the magnetization direction of the entire first fixed magnetic layer 21 is fixed in the direction opposite to the Y direction in the figure, and the magnetization direction of the free magnetic layer 41 is And a crossing relationship.

As described above, in the first pinned magnetic layer 21, the first ferromagnetic pinned layer 22 and the second ferromagnetic pinned layer 23 are antiferromagnetically coupled, and the magnetization of the second ferromagnetic pinned layer 23 is The artificial ferrimagnetic state (synthetic
ferri pinned).

The first pinned magnetic layer 21 is composed of two ferromagnetic layers (first and second pinned ferromagnetic layers 22 and 23). However, the present invention is not limited to this, and 2M (where M is 1 or more) Or an even number of ferromagnetic layers equal to or larger than an integer. In this case, a nonmagnetic layer is inserted between these ferromagnetic layers, and the magnetization directions of the adjacent ferromagnetic layers are antiparallel and the whole is in a ferrimagnetic state. Is preferred. In order to prevent the shunt of the detection current, it is preferable to set M = 1 as in the present embodiment.

The second pinned magnetic layer 51 includes a third ferromagnetic pinned layer (ferromagnetic layer) 52 and a fourth ferromagnetic pinned layer (ferromagnetic layer) 53, and third and fourth ferromagnetic pinned layers 52 and 53. And a second nonmagnetic layer (nonmagnetic layer) 54 inserted between them. The third ferromagnetic pinned layer 52 includes a second
The fourth ferromagnetic pinned layer 54 is provided on the second nonmagnetic conductive layer 32 side of the nonmagnetic layer 54 and is in contact with the second nonmagnetic conductive layer 32.
Is provided closer to the second antiferromagnetic layer 72 than the second nonmagnetic layer 54 and is in contact with the second antiferromagnetic layer 72.

The third and fourth ferromagnetic pinned layers 52 and 53 are
It is formed of a NiFe alloy, Co, CoNiFe alloy, CoFe alloy, CoNi alloy, or the like, and is particularly preferably formed of Co. In addition, the third and fourth
The ferromagnetic pinned layers 52 and 53 are preferably formed of the same material. The second nonmagnetic layer 54 is formed of Ru, Rh,
It is preferably made of one of Ir, Cr, Re, and Cu or an alloy thereof, and particularly preferably made of Ru. The thickness tp3 of the third ferromagnetic pinned layer 52 is preferably in the range of 1 to ₃ nm.
The film thickness t _p4 is preferably in a range of from 1~3nm of, it is preferably formed thicker than the third ferromagnetic pinned layer 52. The thickness of the second nonmagnetic layer 54 is preferably in the range of 0.3 to 1.2 nm.

The magnetization direction of the fourth ferromagnetic pinned layer 53 is fixed in the opposite direction to the Y direction in the figure by the exchange coupling magnetic field with the second antiferromagnetic layer 72, and the third ferromagnetic pinned layer 52
It is antiferromagnetically coupled to the ferromagnetic pinned layer 53 and its magnetization direction is fixed in the Y direction in the figure. Accordingly, the magnetization directions of the third ferromagnetic pinned layer 52 and the fourth ferromagnetic pinned layer 53 are antiparallel to each other, and the ferromagnetic pinned layers 52 and 53 are antiferromagnetically coupled.

In order to bring the second pinned magnetic layer 51 into a ferrimagnetic state, the third and fourth ferromagnetic pinned layers 52 and 53 are provided.
It is preferable that the magnitudes of the magnetic moments caused by the magnetizations of the first and second ferromagnetic layers are slightly different from each other. For example, when the third and fourth ferromagnetic pinned layers 52 and 53 are made of the same material, t
_It is better to make _p3 and _tp4 slightly different. In the present embodiment, it is assumed that t _p4 > t _p3 . If the third and fourth ferromagnetic pinned layers 52 and 53 are made of different materials,
The saturation magnetization of the fourth ferromagnetic pinned layers 52 and 53 is M
_p3, M and _p4, third, when the magnetic thickness of the fourth ferromagnetic pinned layers 52 and 53 and _{M p3 · t p3, M p4} · t p4 respectively, M _p3 · t _p3 and M _p4 · t _It is good to make _p4 slightly different.

Since the magnetization directions of the third and fourth ferromagnetic pinned layers 52 and 53 are antiparallel to each other, the magnetic moments of the third and fourth ferromagnetic pinned layers 52 and 53 are in a mutually canceling relationship. However, if the second pinned magnetic layer 51 has t _p4 > t
Since it is configured to be _p3 , the magnetization (magnetic moment) of the fourth ferromagnetic pinned layer 53 slightly remains. This residual magnetization is further amplified by the exchange coupling magnetic field with the second antiferromagnetic layer 72, and the magnetization direction of the entire second fixed magnetic layer 51 is fixed in the direction opposite to the Y direction in the drawing, and The relationship is parallel to the magnetization direction.

As described above, the second pinned magnetic layer 51 has the third,
The fourth ferromagnetic pinned layers 52 and 53 are antiferromagnetically coupled,
Since the magnetization of the fourth ferromagnetic pinned layer 53 remains, an artificial ferrimagnetic state (synthetic ferri pinne
d; Synthetic ferripind).

The second pinned magnetic layer 51 is composed of two ferromagnetic layers (third and fourth pinned ferromagnetic layers 52 and 53), but is not limited to this. 2N (where N is 1 or more) Or an even number of ferromagnetic layers equal to or larger than an integer. In this case, a nonmagnetic layer is inserted between these ferromagnetic layers, and the magnetization directions of the adjacent ferromagnetic layers are antiparallel and the whole is in a ferrimagnetic state. Is preferred. In order to prevent the shunt of the detection current, N = 1 may be set as in the present embodiment.

When the first and second fixed magnetic layers 21 and 51 and the free magnetic layer 41 are configured as described above, as shown in FIGS. 1 and 2, each of the first and second fixed magnetic layers 21 and 51 And the magnetization direction of the free magnetic layer 41 crosses, and the magnetization direction of the first pinned magnetic layer 21 and the second pinned magnetic layer 5 intersect.
1 becomes parallel to the magnetization direction.

In particular, the thickness t _{p2 of} the second ferromagnetic pinned layer 23
And thicker than the first ferromagnetic pinned layer 22, since the thickness t _p4 of the fourth ferromagnetic pinned layer 53 is thicker than the third ferromagnetic pinned layer 52, a ferromagnetic constituting the first fixed magnetic layer 21 The magnetization direction of the second ferromagnetic pinned layer 23 closest to the free magnetic layer 41 among the layers (the direction opposite to the Y direction in the drawing) and the free magnetic layer among the ferromagnetic layers constituting the second pinned magnetic layer 51 The magnetization direction (Y direction in the drawing) of the third ferromagnetic pinned layer 52 close to 41 is antiparallel.

FIG. 5 shows the second ferromagnetic pinned layer 23 and the first
The magnetic moments of the ferromagnetic free layer 42, the second ferromagnetic free layer 43, and the third ferromagnetic pinned layer 52 are indicated by arrows. Reference numeral Hp1 indicates a magnetic moment due to the magnetization of the second ferromagnetic pinned layer 23, and reference numeral Hp2 indicates a magnetic moment due to the magnetization of the third ferromagnetic pinned layer 52. H
The direction of p1 is the direction opposite to the Y direction shown, and the direction of Hp2 is the Y direction shown.
Direction. Reference numeral Hf1 indicates a magnetic moment due to the magnetization of the first ferromagnetic free layer 42, and reference numeral Hf2 indicates a magnetic moment due to the magnetization of the second ferromagnetic free layer 43. The direction of Hf1 is the illustrated X1 direction, and the direction of Hf2 is the opposite direction to the illustrated X1 direction.

Although not shown, the first nonmagnetic conductive layer 31 is disposed between the second ferromagnetic pinned layer 23 and the first ferromagnetic free layer 42, and the third ferromagnetic pinned layer 52 and the 2
The second nonmagnetic conductive layer 32 is disposed between the ferromagnetic free layers 43, and the nonmagnetic intermediate layer 44 is disposed between the first and second ferromagnetic free layers 42 and 43.

The second ferromagnetic pinned layer 23 and the first ferromagnetic free layer 42 are ferromagnetically interlayer-coupled via the first non-magnetic conductive layer 31, and the magnetic field moment H due to the ferromagnetic interlayer coupling magnetic field is generated.
b1 occurs. The direction of the magnetic field moment Hb1 is the second
The direction is parallel to the magnetization direction of the ferromagnetic pinned layer 23 and opposite to the illustrated Y direction. Further, the third ferromagnetic pinned layer 52 and the second ferromagnetic free layer 43 are coupled to each other through the second nonmagnetic conductive layer 32, and a magnetic field moment Hb2 is generated by the ferromagnetic interlayer coupling magnetic field. The direction of the magnetic field moment Hb2 is parallel to the magnetization direction of the third pinned ferromagnetic layer 52, and is the Y direction in the figure. Therefore, the magnetic field moment Hb1,
Each direction of Hb2 becomes antiparallel.

Therefore, the magnetic field moments Hb1 and Hb2 applied to the free magnetic layer 41 cancel each other, and the direction of the magnetization of the entire free magnetic layer 41, which is the combined magnetization of Hf1 and Hf2, is changed to the first and second directions. The layers are not tilted by the ferromagnetic interlayer coupling magnetic field with the fixed magnetic layers 21 and 51 and are aligned in the X1 direction by the bias layers 18 and 18.

The magnetic field applied to the free magnetic layer 41 includes the above-described magnetic field moments Hb1 and Hb2 of the ferromagnetic interlayer coupling magnetic field in addition to the bias magnetic fields from the bias layers 18 and 18. According to the magnetic element 11,
Since the sum of these can be set to 0, the magnetization direction of the free magnetic layer 41 does not tilt due to these magnetic moments, and the asymmetry of the spin-valve thin-film magnetic element 11 can be reduced.

Next, a method for manufacturing the spin-valve thin-film magnetic element 11 will be described. First, as shown in FIG.
On the lower insulating layer 164, the underlayer 15, the second antiferromagnetic layer 7
2, the second pinned magnetic layer 51, the second nonmagnetic conductive layer 32, the free magnetic layer 41, the first nonmagnetic conductive layer 31, the first fixed magnetic layer 21, the first antiferromagnetic layer 71, and the cap layer 14 in this order. After forming a laminated film M by forming a film by means such as sputtering or vapor deposition, a lift-off resist 101 is formed on the laminated film M.
To form

The first pinned magnetic layer 21 is formed by laminating a first ferromagnetic pinned layer 22, a first nonmagnetic layer 24, and a second ferromagnetic pinned layer 23. In addition, the free magnetic layer 4
1 denotes a first ferromagnetic free layer 22, a non-magnetic intermediate layer 24, and a second
It is formed by laminating the ferromagnetic free layer 23. Further, the second pinned magnetic layer 51 is formed by laminating a third ferromagnetic pinned layer 52, a second nonmagnetic layer 54, and a fourth ferromagnetic pinned layer 53. As shown in FIG. 6, the second ferromagnetic pinned layer 23 is formed thicker than the first ferromagnetic pinned layer 22, and the first ferromagnetic free layer 42 is formed thicker than the second ferromagnetic free layer 43. The fourth ferromagnetic pinned layer 53 is formed thicker than the third ferromagnetic pinned layer 52.

Next, as shown in FIG. 7, the portion not covered by the lift-off resist 101 is removed by ion milling to form an inclined surface and form a trapezoidal stacked body 11A.
To form

Next, as shown in FIG. 8, a bias underlayer 19, a bias layer 18, an intermediate layer 17 and a conductive layer 16 are sequentially laminated on the lift-off resist 101 and on both sides of the laminate 11A. Next, as shown in FIG. 9, the lift-off resist 101 is removed. Thus, the spin-valve thin-film magnetic element 11 is formed.

Next, the first and second antiferromagnetic layers 71 and 72 of the spin-valve thin film magnetic element 11 are heat-treated in a magnetic field,
An exchange coupling magnetic field is developed at each interface between the first and second antiferromagnetic layers 71 and 72 and the first and second pinned magnetic layers 21 and 51. FIG. 10 is a sectional view of the spin-valve thin-film magnetic element 11 shown in FIG. 9 as viewed from the track width direction. As shown in FIG. 10, heat treatment is performed while applying an external magnetic field H in the direction opposite to the Y direction in the figure. The external magnetic field H at this time
Are ferromagnetic pinned layers 22, 23, 52, 53 constituting the first fixed magnetic layer 21 and the second fixed magnetic layer 51, respectively.
Is preferably a magnetic field smaller than a magnetic field that causes a spin-flop transition (hereinafter, referred to as a spin-flop magnetic field). The spin flop magnetic field refers to the magnitude of the external magnetic field when the magnetization directions of the two magnetic layers are not antiparallel when an external magnetic field is applied to the two magnetic layers whose magnetization directions are antiparallel.

FIG. 11 illustrates the spin-flop magnetic field.
FIG. This MH curve is an example.
External magnetic field H with respect to the first pinned magnetic layer 21 shown in FIG.
The change in the magnetization M of the first pinned magnetic layer 21 when applied is
It is shown. In FIG. 11, the arrow indicated by P1 is the first arrow.
1 represents the magnetization direction of the ferromagnetic pinned layer 22, and is indicated by an arrow P2.
The mark indicates the magnetization direction of the second ferromagnetic pinned layer 23. FIG.
As shown in the figure, when the external magnetic field H is small, the first ferromagnetic
The pinned layer 22 and the second ferromagnetic pinned layer 23
The connected state, that is, the directions of the arrows P1 and P2 are flat.
But the magnitude of the external magnetic field H exceeds a certain value
Then, the antiferromagnetism of the first and second ferromagnetic pinned layers 22 and 23
The magnetic coupling is broken, and the ferrimagnetic state cannot be maintained. this
Is a spin-flop transition. Also this spin flop
The magnitude of the external magnetic field when the transition occurs
A magnetic field, and in FIG. _SpIndicated by. In the figure
H_cpRepresents the coercive force of the first pinned magnetic layer 21;_sIs the first
5 shows the saturation magnetization of the fixed magnetic layer 21.

Therefore, as shown in FIG. 10, an external magnetic field H smaller than the spin flop magnetic field is applied from the height direction side of the spin-valve thin film magnetic element 11 to the medium facing surface 152 side (the direction opposite to the Y direction in the drawing). Then, the second and fourth
The magnetization directions of the ferromagnetic pinned layers 23 and 53 are the same as the direction of the external magnetic field H (the direction opposite to the Y direction in the figure), and the magnetization directions of the first and third ferromagnetic pinned layers 22 and 52 are the second and third directions. The direction is opposite to the magnetization direction of the fourth ferromagnetic pinned layers 23 and 53 (the Y direction in the drawing). The magnetization directions of the second and fourth ferromagnetic pinned layers 23 and 53 are the same as the direction of the external magnetic field H (the Y direction in the drawing) because the film thickness of these ferromagnetic pinned layers 23 and 53 is 1, the third ferromagnetic pinned layer 22,
This is because the external magnetic field H is more likely to act on the second and fourth ferromagnetic pinned layers 23 and 53 because the film thickness is larger than the film thickness of 52.

The magnitude of the external magnetic field H is preferably smaller than the spin-flop magnetic field of the first and second pinned magnetic layers 21 and 22, specifically, 8.0 × 10 ⁴ A / m.
The following external magnetic field is preferable. The heat treatment is performed in a vacuum atmosphere or an inert gas atmosphere.
The heat treatment is preferably performed at a heat treatment temperature of 3 to 573 K for 60 to 600 minutes. By performing the heat treatment as described above, the crystal structure of the first and second antiferromagnetic layers 71 and 72 is regularized, and an exchange coupling magnetic field is generated at the interface with the first and second pinned magnetic layers 21 and 51.

After the completion of the heat treatment, the external magnetic field H is removed. When the external magnetic field H is removed, as shown in FIG. 12, the magnetization directions of the second and fourth ferromagnetic pinned layers 23 and 53 become Y
The first and third ferromagnetic pinned layers 2
The magnetization directions 2 and 52 are the Y directions in the figure. In this manner, the first and second ferromagnetic pinned layers 22 and 23 are antiferromagnetically coupled, the first pinned magnetic layer 21 enters the ferrimagnetic state, and the magnetization direction of the entire first pinned magnetic layer is changed to Y in the figure. In the opposite direction. Similarly, the third and fourth ferromagnetic pinned layers 52,
53 is antiferromagnetically coupled, so that the second pinned magnetic layer 51 enters a ferrimagnetic state, and the magnetization direction of the entire second pinned magnetic layer 51 becomes the Y direction in the figure.

Finally, the bias layers 18 are magnetized to generate a bias magnetic field, and the magnetization direction of the entire free magnetic layer 41 is aligned with the X1 direction in the figure. Thus, a spin-valve thin-film magnetic element 11 as shown in FIGS. 1 and 2 is obtained.

According to the spin-valve thin-film magnetic element 11 described above, since the magnetization direction of the second ferromagnetic pinned layer 23 and the magnetization direction of the third ferromagnetic pinned layer 52 are antiparallel, the free magnetic layer 41 and the second, Since the magnetic field moments Hb1 and Hb2 of the ferromagnetic interlayer coupling magnetic field generated by the ferromagnetic interlayer coupling with the third ferromagnetic pinned layers 22 and 52 cancel each other out, the magnetization direction of the entire free magnetic layer 41 is not inclined, and the asymmetry is improved. Can be smaller.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to the drawings. FIG. 13 shows a spin-valve thin-film magnetic element 12 according to a second embodiment of the present invention.
14 is a schematic cross-sectional view of the spin-valve thin-film magnetic element 12 as viewed from the magnetic recording medium side, and FIG.

The spin-valve thin-film magnetic element 12 shown in FIGS. 13 and 14 constitutes the thin-film magnetic head 1 like the spin-valve thin-film magnetic element 11 of the first embodiment.
The thin-film magnetic head 1 constitutes a floating magnetic head 150 together with the inductive head h.

This spin-valve thin-film magnetic element 12
Similarly to the spin-valve thin-film magnetic element 11 of the first embodiment, a dual spin valve in which a nonmagnetic conductive layer, a fixed magnetic layer, and an antiferromagnetic layer are sequentially laminated on both sides in the thickness direction of the free magnetic layer 41 It is a thin-film magnetic element.

That is, the spin-valve thin-film magnetic element 12
Indicates that the second antiferromagnetic layer 72, the second pinned magnetic layer 81, the second nonmagnetic conductive layer 32, the free magnetic layer 41, the first nonmagnetic conductive layer are formed on the underlayer 15 laminated on the lower insulating layer 164. 31,
The first pinned magnetic layer 61, the first antiferromagnetic layer 71, and the cap layer 14 are sequentially laminated. In this way, the respective layers from the base layer 15 to the cap layer 14 are sequentially laminated to form a laminate 12A having a width corresponding to the track width and having a substantially trapezoidal shape in cross section.

The spin-valve thin-film magnetic element 1 according to the first embodiment described above is the spin-valve thin-film magnetic element 1
1 is that the ferromagnetic pinned layers 62, 63, 82, 83 constituting the first and second pinned magnetic layers 61, 81, respectively.
The point is that the relationship of the film thicknesses is reversed.

The first and second antiferromagnetic layers 71 and 72, the first and second nonmagnetic conductive layers 31 and 3 shown in FIGS.
2. Free magnetic layer 41 (first and second ferromagnetic free layers 42,
43, nonmagnetic intermediate layer 44), conductive layers 16, 16, intermediate layers 17, 17, bias layers 18, 18, and bias underlayers 19, 19 are the upper and lower antiferromagnetic layers described in the first embodiment. 71, 72, upper and lower nonmagnetic conductive layers 31, 3
2. Free magnetic layer 41 (first and second ferromagnetic free layers 42,
43, the nonmagnetic intermediate layer 44), the conductive layers 16, 16, the intermediate layers 17, 17, the bias layers 18, 18, and the bias underlayers 19, 19.

The first pinned magnetic layer 61 includes a first ferromagnetic pinned layer (ferromagnetic layer) 62 and a second ferromagnetic pinned layer (ferromagnetic layer) 63, and first and second ferromagnetic pinned layers 62 and 63. And a first non-magnetic layer (non-magnetic layer) 64 inserted therebetween. The first ferromagnetic pinned layer 62 is in contact with the first antiferromagnetic layer 71, and the second ferromagnetic pinned layer 63 is in contact with the first nonmagnetic conductive layer 31.

The first and second ferromagnetic pinned layers 62 and 63 and the first nonmagnetic layer 64 are the same as the first and second ferromagnetic pinned layers 22 and 23 and the first nonmagnetic layer 24 of the first embodiment. It is made of the same material. The thickness t _p1 of the first ferromagnetic pinned layer 62 is 1 to
Preferably in the range of 3 nm, the thickness t _p2 of the second ferromagnetic pinned layer 63 is preferably in the range of 1 to 3 nm, it is preferable thinner than the first ferromagnetic pinned layer 62. The thickness of the first nonmagnetic layer 64 is preferably in the range of 0.3 to 1.2 nm.

The magnetization direction of the first ferromagnetic pinned layer 62 is fixed in the Y direction in the figure by an exchange coupling magnetic field with the first antiferromagnetic layer 71, and the second ferromagnetic pinned layer 63 is 62 and the magnetization direction is Y
It is fixed in the opposite direction. Therefore, the magnetization directions of the first ferromagnetic pinned layer 62 and the second ferromagnetic pinned layer 63 are antiparallel, and the first ferromagnetic pinned layer 62 and the second
The ferromagnetic pinned layer 63 is antiferromagnetically coupled.

In order to bring the first pinned magnetic layer 61 into a ferrimagnetic state, the first and second ferromagnetic pinned layers 62 and 63 are provided.
It is preferable that the magnitudes of the magnetic moments due to the magnetizations be slightly different. For this purpose, for example, when the first and second ferromagnetic pinned layers 62 and 63 are made of the same material, t
_It is good to make _p1 and _tp2 slightly different. In the present embodiment, it is assumed that t _p1 > t _p2 . When the first and second ferromagnetic pinned layers 62 and 63 are made of different materials, M _p1 · t _p1 and M _p2 · t _p2 are slightly different from each other as in the case of the first embodiment. And good.

Since the magnetization directions of the first and second ferromagnetic pinned layers 62 and 63 are antiparallel to each other, the magnetic moments of the first and second ferromagnetic pinned layers 62 and 63 cancel each other. However, the first pinned magnetic layer 61 has t _p1 > t
Since it is configured to be _p2 , the magnetization (magnetic moment) of the first ferromagnetic pinned layer 62 slightly remains. This residual magnetization is further amplified by the exchange coupling magnetic field with the first antiferromagnetic layer 71, the magnetization direction of the entire first fixed magnetic layer 61 is fixed in the Y direction in the drawing, and crosses the magnetization direction of the free magnetic layer 41. Become a relationship.

As described above, the first pinned magnetic layer 61 has the first
Since the second ferromagnetic pinned layers 62 and 63 are antiferromagnetically coupled and the magnetization of the first ferromagnetic pinned layer 62 remains, an artificial ferrimagnetic state is established.

The first pinned magnetic layer 61 may be composed of an even number of ferromagnetic layers of 2M or more (where M is an integer of 1 or more) as in the first embodiment. In order to prevent the shunt of the detection current, it is preferable to set M = 1.

The second pinned magnetic layer 81 includes a third ferromagnetic pinned layer (ferromagnetic layer) 82 and a fourth ferromagnetic pinned layer (ferromagnetic layer) 83, and third and fourth ferromagnetic pinned layers 82, 83. And a second nonmagnetic layer (nonmagnetic layer) 84 inserted between them. The third ferromagnetic pinned layer 82 is in contact with the second nonmagnetic conductive layer 32, and the fourth ferromagnetic pinned layer 83 is
It is in contact with the antiferromagnetic layer 72. The third and fourth ferromagnetic pinned layers 82 and 83 and the second nonmagnetic layer 84 are made of the same material as the third and fourth ferromagnetic pinned layers 52 and 53 and the second nonmagnetic layer 54 of the first embodiment. Consists of

The thickness t _p3 of the third ferromagnetic pinned layer 82 is 1 to
Preferably in the range of 3 nm, the thickness t _p4 of the fourth ferromagnetic pinned layer 83 is preferably in the range of 1 to 3 nm, it is preferable thinner than the third ferromagnetic pinned layer 82. The thickness of the second nonmagnetic layer 84 is preferably in the range of 0.3 to 1.2 nm. The magnetization direction of the fourth ferromagnetic pinned layer 83 is fixed in a direction opposite to the illustrated Y direction by an exchange coupling magnetic field with the second antiferromagnetic layer 72, and the third ferromagnetic pinned layer 82 is 83, and its magnetization direction is fixed in the Y direction in the figure.

Accordingly, the magnetization directions of the third pinned ferromagnetic layer 82 and the fourth pinned ferromagnetic layer 83 are antiparallel, and the third and fourth pinned ferromagnetic layers 82 and 83 are antiferromagnetically coupled. are doing. In order to bring the second pinned magnetic layer 81 into a ferrimagnetic state, the third and fourth ferromagnetic pinned layers 82,
It is preferable that the magnitude of the magnetic moment due to the magnetization of 83 be slightly different. For this purpose, for example, when the third and fourth ferromagnetic pinned layers 82 and 83 are made of the same material, _tp3 and _tp4 may be slightly changed. It is better to make it different. In the present embodiment, it is assumed that t _p3 > t _p4 . When the third and fourth ferromagnetic pinned layers 82 and 83 are made of different materials,
As in the first embodiment, M _p3 · t _p3 and M _p4 · t _p4
And slightly different.

Since the magnetization directions of the third and fourth ferromagnetic pinned layers 82 and 83 are antiparallel to each other, the magnetic moments of the third and fourth ferromagnetic pinned layers 82 and 83 are in a mutually canceling relationship. However, if the second pinned magnetic layer 81 has t _p3 > t
Since it is configured to be _p4 , the magnetization (magnetic moment) of the third ferromagnetic pinned layer 82 slightly remains. This residual magnetization is further amplified by the exchange coupling magnetic field with the second antiferromagnetic layer 72, the magnetization direction of the entire second fixed magnetic layer 81 is fixed in the Y direction in the drawing, and the magnetization direction of the first fixed magnetic layer 61 is The relationship is parallel.

As described above, the second pinned magnetic layer 81 has the third,
Since the fourth ferromagnetic pinned layers 82 and 83 are antiferromagnetically coupled and the magnetization of the third ferromagnetic pinned layer 82 remains, an artificial ferrimagnetic state is established.

The second pinned magnetic layer 81 may be composed of an even number of ferromagnetic layers of 2N (where N is an integer of 1 or more) as in the first embodiment. In order to prevent the shunt of the detection current, N = 1 may be set.

[0095] As described above in the spin valve thin film magnetic element 12, the thickness t _p2 of the second ferromagnetic pinned layer 63,
Thinner than the first ferromagnetic pinned layer 62, since the thickness t _p4 of the fourth ferromagnetic pinned layer 83 are thinner than the third ferromagnetic pinned layer 82, a ferromagnetic layer constituting the first pinned magnetic layer 61 , The second ferromagnetic pinned layer 6 closest to the free magnetic layer 41
3 (the direction opposite to the Y direction in the figure) and the free magnetic layer 4 among the ferromagnetic layers constituting the second pinned magnetic layer 81.
The magnetization direction (Y direction in the drawing) of the third ferromagnetic pinned layer 82 close to 1 becomes antiparallel.

Therefore, in the spin-valve thin-film magnetic element 12 described above, as in the case of the spin-valve thin-film magnetic element 11 of the first embodiment, the second ferromagnetic pinned layer 6 is formed.
The direction of the magnetic moment Hb1 of the ferromagnetic exchange coupling magnetic field applied to the free magnetic layer 41 by the ferromagnetic interlayer coupling between the third ferromagnetic free layer 42 and the third ferromagnetic pinned layer 82 and the second ferromagnetic The direction of the magnetic field moment Hb2 of the ferromagnetic exchange coupling magnetic field applied to the free magnetic layer 41 due to the ferromagnetic interlayer coupling with the free layer 43 becomes antiparallel.

Therefore, since the magnetic field moments Hb 1 and Hb 2 cancel each other in the free magnetic layer 41, the magnetization directions of the entire free magnetic layer 41 are changed to the first and second fixed magnetic layers 61 and 8.
The bias layers 18 and 18 do not tilt due to the ferromagnetic interlayer coupling magnetic field, and are aligned in the track width direction.

The above-described spin-valve type thin-film magnetic element 12
Except that the thickness of the second ferromagnetic pinned layer 63 is smaller than that of the first ferromagnetic pinned layer 62 and the thickness of the fourth ferromagnetic pinned layer 83 is smaller than that of the third ferromagnetic pinned layer 82. It can be manufactured in the same manner as the spin-valve thin-film magnetic element 11 of the first embodiment.

According to the spin-valve thin-film magnetic element 12, the same effects as those of the spin-valve thin-film magnetic element 11 of the first embodiment can be obtained.

[0100]

As described above in detail, in the spin-valve thin film magnetic element of the present invention, one of the fixed magnetic layers is
L, that is, an even number of ferromagnetic layers, and the other pinned magnetic layer is a 2N ferromagnetic layer, that is, an even number of ferromagnetic layers. At the same time, since the magnetization directions of the ferromagnetic layers closest to the free magnetic layer among the ferromagnetic layers constituting these pinned magnetic layers are made antiparallel, the magnetization direction of the free magnetic layer is changed to the magnetization direction of the fixed magnetic layer. They can be aligned in the orthogonal direction. Therefore, in the spin-valve thin film magnetic element of the present invention, the free magnetic layer is hardly affected by the magnetization of the fixed magnetic layer, and the asymmetry can be reduced.

The thin-film magnetic head of the present invention is a thin-film magnetic head comprising the above-described spin-valve thin-film magnetic element and capable of reading magnetic information. The floating magnetic head of the present invention is A slider is provided with the above-described thin film magnetic head. Therefore, since the above-mentioned thin film magnetic head and flying magnetic head are provided with the spin valve type thin film magnetic element having small asymmetry, they are excellent in the symmetry of the reproduction waveform, and the frequency of errors during reproduction can be reduced. .

In the method of manufacturing a spin-valve thin-film magnetic element of the present invention, one of the fixed magnetic layers is inserted between a ferromagnetic layer of 2M or more (where M is an integer of 1 or more) and these ferromagnetic layers. A non-magnetic layer, and the free magnetic layer
(Where L is an integer of 1 or more) ferromagnetic layers and a nonmagnetic intermediate layer inserted between these ferromagnetic layers,
2N (where N is an integer of 1 or more)
An external magnetic field smaller than the magnetic field at which the ferromagnetic layers constituting one and the other fixed magnetic layers are spin-flop-transformed is constituted by the above ferromagnetic layer and the non-magnetic layer inserted between these ferromagnetic layers. Heat treatment to generate an exchange coupling magnetic field between the one and other antiferromagnetic layers and the one and the other fixed magnetic layers, so that the spin-valve thin-film magnetic element having the above structure can be easily manufactured. can do.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of a spin-valve thin-film magnetic element according to a first embodiment of the present invention as viewed from a magnetic recording medium side.

FIG. 2 is a schematic cross-sectional view of the spin-valve thin-film magnetic element of FIG. 1 as viewed from a track width direction side.

FIG. 3 is a perspective view showing a floating magnetic head including a spin-valve thin-film magnetic element according to the first embodiment of the present invention.

FIG. 4 is a cross-sectional view showing a main part of a thin-film magnetic head including a spin-valve thin-film magnetic element according to a first embodiment of the present invention.

FIG. 5 is a schematic diagram for explaining a ferromagnetic interlayer coupling magnetic field generated between first and second fixed magnetic layers and a free magnetic layer of the spin-valve thin-film magnetic element of FIG. 1;

FIG. 6 is a process chart for explaining a method of manufacturing the spin-valve thin-film magnetic element shown in FIG.

FIG. 7 is a process chart for describing a method of manufacturing the spin-valve thin-film magnetic element shown in FIG.

FIG. 8 is a process chart for explaining a method of manufacturing the spin-valve thin-film magnetic element shown in FIG.

FIG. 9 is a process chart for explaining a method of manufacturing the spin-valve thin-film magnetic element shown in FIG.

FIG. 10 is a process chart for explaining a method of manufacturing the spin-valve thin-film magnetic element shown in FIG.

FIG. 11 is a graph showing an MH curve of a fixed magnetic layer.

FIG. 12 is a process chart for describing a method of manufacturing the spin-valve thin-film magnetic element shown in FIG.

FIG. 13 is a schematic sectional view of a spin-valve thin-film magnetic element according to a second embodiment of the present invention, as viewed from a magnetic recording medium side.

14 is a schematic cross-sectional view of the spin-valve thin-film magnetic element of FIG. 13 as viewed from the track width direction side.

FIG. 15 is a schematic cross-sectional view of a conventional spin-valve thin-film magnetic element viewed from a magnetic recording medium side.

16 is a schematic cross-sectional view of the spin-valve thin-film magnetic element of FIG. 15 as viewed from a track width direction side.

17 is a schematic diagram for explaining a ferromagnetic interlayer coupling magnetic field applied to a free magnetic layer of the spin-valve thin-film magnetic element of FIG.

[Description of Signs] 1 Thin-film magnetic head 11, 12 Spin-valve thin-film magnetic element 21, 61 First fixed magnetic layer (one fixed magnetic layer) 22, 62 First ferromagnetic pinned layer (ferromagnetic layer) 23, 63 Second ferromagnetic pinned layer (ferromagnetic layer) 24, 64 First nonmagnetic layer (nonmagnetic layer) 31 First nonmagnetic conductive layer (one nonmagnetic conductive layer) 32 Second nonmagnetic conductive layer (the other nonmagnetic layer) Magnetic conductive layer) 41 free magnetic layer 42 first ferromagnetic free layer (ferromagnetic layer) 43 second ferromagnetic free layer (ferromagnetic layer) 44 nonmagnetic intermediate layer 51, 81 second pinned magnetic layer (the other pinned magnetism) Layer, 52, 82 Third ferromagnetic pinned layer (ferromagnetic layer) 53, 83 Fourth ferromagnetic pinned layer (ferromagnetic layer) 54, 84 Second nonmagnetic layer (nonmagnetic layer) 71 First antiferromagnetic layer (One antiferromagnetic layer) 72 Second antiferromagnetic layer (Other antiferromagnetic layer) 16 Conductive layer 18 bias layer 150 floating magnetic head

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yosuke Ide 1-7 Yukitani Otsukacho, Ota-ku, Tokyo Alps Electric Co., Ltd. (72) Inventor Fumito Koike 1-7 Yukitani-Otsukacho, Ota-ku, Tokyo Alp (72) Inventor Naoya Hasegawa 1-7 Yukiya Otsuka-cho, Ota-ku, Tokyo Alps Electric Co., Ltd. F-term (reference) 5D034 BA04 BA05 BB12 BB20 CA00 CA08 DA07

Claims (9)

[Claims] A nonmagnetic conductive layer, a pinned magnetic layer, and an antiferromagnetic layer are sequentially laminated on both sides in the thickness direction of the free magnetic layer, and the free magnetic layer, the pair of nonmagnetic conductive layers, A pair of conductive layers for applying a detection current to the pair of fixed magnetic layers; and a pair of bias layers for aligning the magnetization direction of the free magnetic layer, wherein the free magnetic layer is 2L (where L is an integer of 1 or more). )
The above ferromagnetic layers and a non-magnetic intermediate layer inserted between these ferromagnetic layers are laminated, and the magnetization directions of the adjacent ferromagnetic layers are made antiparallel, so that the entire ferromagnetic layer is ferrimagnetic. The pinned magnetic layer is in a magnetic state, and is formed by laminating a ferromagnetic layer of 2M or more (where M is an integer of 1 or more) and a non-magnetic layer inserted between these ferromagnetic layers. At the same time, the respective magnetization directions of the adjacent ferromagnetic layers are set to be antiparallel, and the whole is brought into a ferrimagnetic state, and the magnetization direction of the one fixed magnetic layer as a whole is the same as the one of the adjacent antiferromagnetic layers. The free magnetic layer is fixed in the direction crossing the magnetization direction of the entire free magnetic layer, and the other fixed magnetic layer has a ferromagnetic layer of 2N (N is an integer of 1 or more) or more and a ferromagnetic layer of these ferromagnetic layers. When the non-magnetic layer inserted between them is laminated The magnetization direction of each of the adjacent ferromagnetic layers is antiparallel, the whole is in a ferrimagnetic state, and the magnetization direction of the other fixed magnetic layer is the same as that of the adjacent one of the antiferromagnetic layers. The magnetization direction of the ferromagnetic layer closest to the free magnetic layer among the ferromagnetic layers constituting the one fixed magnetic layer, which is fixed in a direction parallel to the magnetization direction of the one fixed magnetic layer by an exchange coupling magnetic field; A spin-valve thin-film magnetic element, wherein the magnetization direction of the ferromagnetic layer closest to the free magnetic layer among the ferromagnetic layers constituting the other fixed magnetic layer is antiparallel. 2. A magnetic field of a ferromagnetic exchange coupling magnetic field generated by coupling a ferromagnetic layer closest to a free magnetic layer among the ferromagnetic layers constituting the one fixed magnetic layer with the free magnetic layer. The direction of the moment Hb1 and the direction of the ferromagnetic exchange coupling magnetic field generated by the ferromagnetic interlayer coupling between the ferromagnetic layer closest to the free magnetic layer and the free magnetic layer among the ferromagnetic layers constituting the other fixed magnetic layer. 2. The spin-valve thin-film magnetic element according to claim 1, wherein the direction of the magnetic field moment Hb2 is antiparallel in the free magnetic layer. 3. The spin-valve thin-film magnetic element according to claim 1, wherein the L is 1, the M is 1, and the N is 1. 4. The method according to claim 1, wherein the one fixed magnetic layer comprises first and second fixed magnetic layers.
And a first non-magnetic layer inserted between the first and second ferromagnetic layers, and the second ferromagnetic layer located near the free magnetic layer. The thickness of the magnetic layer is greater than the thickness of the first ferromagnetic layer, and the other fixed magnetic layer is formed of a third and a fourth ferromagnetic layer and a third and a fourth ferromagnetic layer. A second nonmagnetic layer inserted between the layers is laminated, and the third ferromagnetic layer located near the free magnetic layer has a thickness of the fourth magnetic layer.
4. The spin-valve thin-film magnetic element according to claim 1, wherein the thickness is smaller than the thickness of the ferromagnetic layer. 5. The method according to claim 1, wherein the one fixed magnetic layer comprises first and second fixed magnetic layers.
And a first non-magnetic layer inserted between the first and second ferromagnetic layers, and the second ferromagnetic layer located near the free magnetic layer. The thickness of the magnetic layer is smaller than the thickness of the first ferromagnetic layer, and the other fixed magnetic layer is formed of a third and a fourth ferromagnetic layer and a third and a fourth ferromagnetic layer. A second nonmagnetic layer inserted between the layers is laminated, and the third ferromagnetic layer located near the free magnetic layer has a thickness of the fourth magnetic layer.
4. The spin-valve thin-film magnetic element according to claim 1, wherein the thickness is larger than the thickness of the ferromagnetic layer. 6. A thin-film magnetic head capable of reading magnetic information, comprising the spin-valve thin-film magnetic element according to any one of claims 1 to 5. 7. A flying magnetic head comprising the slider having the thin-film magnetic head according to claim 6. 8. A ferromagnetic layer having at least 2M (where M is an integer of 1 or more) antiferromagnetically coupled to one antiferromagnetic layer and a nonmagnetic layer inserted between these ferromagnetic layers And a non-magnetic conductive layer, a non-magnetic conductive layer, and a 2L (where L is an integer of 1 or more) or more ferromagnetic layer that is antiferromagnetically coupled. 2N (where N is an integer of 1 or more) or more ferromagnetic layer antiferromagnetically coupled to a free magnetic layer having a nonmagnetic intermediate layer interposed therebetween and the other nonmagnetic conductive layer And a nonmagnetic layer inserted between these ferromagnetic layers and the other fixed magnetic layer, and the other antiferromagnetic layer are stacked to form a laminate, wherein the one fixed magnetic layer Each of the ferromagnetic layers constituting the layer and the other pinned magnetic layer is smaller than a magnetic field that causes a spin-flop transition. A heat treatment is performed while applying a partial magnetic field to the laminate, so that a heat is applied between the one antiferromagnetic layer and the one fixed magnetic layer and between the other antiferromagnetic layer and the other fixed magnetic layer. A method for producing a spin-valve thin-film magnetic element, characterized by expressing exchange coupling magnetic fields. 9. The magnitude of the external magnetic field is 8.0 × 1.
0 ⁴ method of manufacturing the spin valve thin film magnetic element according to claim 8, characterized in that at most A / m.