JP2002204009A - Method of manufacturing thin-film magnetic element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that it is difficult to allow the magnetization direction of a fixed magnetic layer to orthogonally cross that of a free magnetic layer in the conventional method of manufacturing an exchange bias type thin- film magnetic element. SOLUTION: A multilayer film A containing a first antiferromagnetic layer 12 and the fixed magnetic layer 13 is annealed in a first magnetic field while the multilayer film A is not laminated on a vertical bias layer 18 (second antiferromagnetic layer) to fix the magnetization direction of the fixed magnetic layer in a specific direction. Then, after the vertical bias layer 18 is laminated on the multilayer film A, the magnetization direction of the vertical bias layer is fixed in the annealing in the second magnetic field.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to, for example, an electric resistance based on the relationship between the magnetization direction of a pinned magnetic layer (pinned magnetic layer) and the magnetization direction of a free magnetic layer affected by an external magnetic field. More particularly, the present invention relates to a method of manufacturing a thin film magnetic element capable of coping with a narrow track.

[0002]

2. Description of the Related Art FIG. 34 is a cross-sectional view of a structure of a thin film magnetic element formed by a conventional manufacturing method as viewed from the ABS.

The thin-film magnetic element shown in FIG. 34 is a spin-valve thin-film magnetic element which is a kind of a giant magnetoresistive (GMR) element utilizing a giant magnetoresistive effect, and performs recording from a recording medium such as a hard disk. It detects a magnetic field.

This spin-valve thin-film magnetic element comprises a substrate 8, an antiferromagnetic layer 1, and a pinned magnetic layer (pinned) from below.
Magnetic layer) 2, non-magnetic conductive layer 3, free magnetic layer (Free) 4
And a pair of vertical bias layers 6 and 6 formed on the multilayer film 9 and a pair of electrode layers 7 and 7 formed on the vertical bias layers 6 and 6. It is configured.

The antiferromagnetic layer 1 and the longitudinal bias layers 6, 6
Are Fe-Mn (iron-manganese) alloy films and Ni-Mn
(Nickel-manganese) alloy film, Ni—Fe (nickel-iron) alloy film for fixed magnetic layer 2 and free magnetic layer 4, Cu (copper) film for nonmagnetic conductive layer 3, and electrode layers 8, 8 In general, a Cr film is used.

As shown in FIG. 34, the magnetization of the pinned magnetic layer 2 is converted into a single magnetic domain in the Y direction (direction of the leakage magnetic field from the recording medium; height direction) by the exchange anisotropic magnetic field with the antiferromagnetic layer 1. The magnetization of the free magnetic layer 4 is controlled by the longitudinal bias layers 6 and 6.
It is desirable that they are aligned in the X direction under the influence of the exchange anisotropic magnetic field from the magnetic field.

That is, it is desirable that the magnetization of the fixed magnetic layer 2 and the magnetization of the free magnetic layer 4 are orthogonal to each other.

In this spin-valve thin-film magnetic element, the detection current (sense) is supplied from the electrode layers 7, 7 formed on the vertical bias layers 6, 6 to the free magnetic layer 4, the nonmagnetic conductive layer 3, and the fixed magnetic layer 2. Current). The running direction of a recording medium such as a hard disk is the Z direction, and when a leakage magnetic field from the recording medium is applied in the Y direction, the magnetization of the free magnetic layer 4 changes from the X direction to the Y direction. The electrical resistance changes due to the relationship between the change in the direction of magnetization in the free magnetic layer 4 and the fixed magnetization direction of the fixed magnetic layer 2 (this is referred to as a magnetoresistance effect). Due to the change, a leakage magnetic field from the recording medium is detected.

[0009]

Conventionally, when manufacturing a spin-valve thin-film magnetic element shown in FIG.
An antiferromagnetic layer 1, a pinned magnetic layer (Pinned magnetic layer) 2, a nonmagnetic conductive layer 3, and a free magnetic layer (Free) 4 are successively formed thereon to form a multilayer film 9. The vertical bias layers 6 and 6 and the electrode layers 7 and 7 were continuously formed on the multilayer film 9.

After forming the layers from the antiferromagnetic layer 1 to the electrode layers 7 and 7, first, annealing is performed in a first magnetic field to align the magnetization direction of the fixed magnetic layer 2 in the Y direction. It is necessary to perform annealing in a second magnetic field for aligning the magnetization directions of the layers with the X direction.

However, if annealing in the first magnetic field and annealing in the second magnetic field are performed after the formation of the layers from the antiferromagnetic layer 1 to the electrode layers 7, 7, the anti-ferromagnetic properties in the second annealing in the magnetic field are increased. The exchange anisotropic magnetic field acting on the interface between the magnetic layer 1 and the pinned magnetic layer 2 is tilted from the Y direction to the X direction, and the magnetization direction of the pinned magnetic layer 2 and the magnetization direction of the free magnetic layer 4 become non-orthogonal, so that the output signal Degree of loss of waveform symmetry (asymmetry)
However, there has been a problem that the number increases.

The above-mentioned problem is particularly conspicuous when the antiferromagnetic layer 1 and the longitudinal bias layer 6 are formed of antiferromagnetic materials having the same composition.

The present invention has been made to solve the above-mentioned conventional problems, and a first antiferromagnetic layer and a second antiferromagnetic layer are vertically arranged via another layer including a fixed magnetic layer and a free magnetic layer. The first antiferromagnetic layer is subjected to annealing in a first magnetic field, followed by laminating the second antiferromagnetic layer and annealing in a second magnetic field. The object of the present invention is to provide a method for manufacturing a spin-valve thin-film magnetic element in which the magnetization of the pinned magnetic layer and the magnetization of the free magnetic layer can be made orthogonal to each other.

[0014]

According to the present invention, there is provided a method of manufacturing a thin film magnetic element comprising the steps of (a) forming a multilayer film having a first antiferromagnetic layer, a fixed magnetic layer, a nonmagnetic material layer, and a free magnetic layer on a substrate. Forming a film, and (b) subjecting the multilayer film to a first heat treatment temperature;
Annealing in a magnetic field in a first magnitude magnetic field to fix the magnetization direction of the fixed magnetic layer in a predetermined direction;
(C) forming a second antiferromagnetic layer on the multilayer film; and (d) forming a multilayer film on which the second antiferromagnetic layer is laminated.
A step of fixing the magnetization direction of the free magnetic layer in a direction orthogonal to the magnetization direction of the fixed magnetic layer by annealing in a magnetic field at a second heat treatment temperature and a magnetic field of a second magnitude. It is a feature.

In the present invention, the multilayer film is annealed in a magnetic field to fix the magnetization direction of the fixed magnetic layer in a predetermined direction without laminating the second antiferromagnetic layer on the multilayer film. When the second antiferromagnetic layer is laminated on the multilayer film, no exchange anisotropic magnetic field is generated in the second antiferromagnetic layer.

That is, the exchange anisotropic magnetic field of the second antiferromagnetic layer is generated only in the step (d), and the magnetization direction of the free magnetic layer can be easily moved in a predetermined direction. Therefore, it is easy to fix the magnetization direction of the free magnetic layer in a direction orthogonal to the magnetization direction of the fixed magnetic layer.

Preferably, the step (a) is performed in the same vacuum film forming apparatus.

In the present invention, in the step (d),
Preferably, the second heat treatment temperature is set to a temperature lower than a blocking temperature at which the first antiferromagnetic layer loses the exchange coupling magnetic field.

Further, in the present invention, in the step (d), the magnitude of the second magnetic field is preferably smaller than the exchange anisotropic magnetic field of the first antiferromagnetic layer.

It is preferable that the step (a) includes a step of laminating another antiferromagnetic layer on the uppermost layer of the multilayer film, since oxidation of the uppermost layer of the multilayer film can be prevented.

According to the present invention, the other antiferromagnetic layer is made of a material capable of forming an energy gap having a high probability of causing specular reflection for preserving the spin state of conduction electrons. Can function as a specular reflection layer that extends the mean free path of conduction electrons by the specular reflection effect.

When the other antiferromagnetic layer functions as a specular reflection layer, the thickness of the free magnetic layer is 15 to 45.
It is preferable to set in the range of Å.

If the thickness of the free magnetic layer is smaller than 15 °, it is difficult to form the free magnetic layer so as to function as a ferromagnetic material layer, and a sufficient magnetoresistance effect cannot be obtained.

If the thickness of the free magnetic layer is larger than 45 °, upspin conduction electrons which are scattered before reaching the specular reflection layer increase and the specular reflection effect (speculum reflection effect) increases.
This is not preferable because the rate at which the resistance change rate changes due to the ar effect decreases.

The other antiferromagnetic layer serving as the specular reflection layer can be formed as a single-layer film or a multilayer film of a semi-metallic Whistler alloy such as NiMnSb or PtMnSb.

By using these materials, a sufficient potential barrier can be formed between adjacent layers, and as a result, a sufficient specular reflection effect can be obtained.

The thickness of the other antiferromagnetic layer is preferably larger than 0 and 30 ° or less.

If the thickness of the other antiferromagnetic layer is larger than 0 and equal to or less than 30 °, no exchange coupling magnetic field is generated in the other antiferromagnetic layer in the step (b). It is possible to prevent the magnetization direction of the ferromagnetic layer from being fixed in the same direction as the magnetization direction of the fixed magnetic layer. Therefore, in the step (c), when the second antiferromagnetic layer is laminated on the another antiferromagnetic layer, the magnetization direction of the free magnetic layer is different from the magnetization direction of the fixed magnetic layer. It can be prevented from being fixed in the same direction.

The other antiferromagnetic layer has a thickness of 10 °.
More preferably, the angle is not less than 30 °.

In the step (a), a nonmagnetic layer may be laminated on the upper or lower surface of the free magnetic layer in contact with the surface remote from the nonmagnetic material layer.

At this time, the magnetization direction of the free magnetic layer is directed to a direction crossing the magnetization direction of the fixed magnetic layer by RKKY coupling with the second antiferromagnetic layer via the nonmagnetic layer. .

The magnetic layer whose magnetization direction is aligned by the RKKY interaction with the second antiferromagnetic layer is more exchangeable than the magnetic layer in which the second antiferromagnetic layer is in direct contact with the magnetic layer. The bonding force can be increased.

It is preferable that the non-magnetic layer is formed of a conductive material. The non-magnetic layer is made of, for example, R
It can be formed using one or more of u, Cu, Ag, and Au. In particular, it is preferable that the nonmagnetic layer is formed of Ru and has a thickness of 8 to 11 °.

When the non-magnetic layer is formed of a conductive material as in the present invention, the non-magnetic layer is formed as a backed layer having a spin filter effect.
er).

When the backed layer having the spin filter effect is provided in contact with the free magnetic layer, the position of the center where the sense current flows inside the laminated body is moved to the backed layer side as compared with the case where there is no backed layer. be able to. That is, the center height position of the sense current is separated from the free magnetic layer, the intensity of the sense current magnetic field at the position of the free magnetic layer is reduced, and the influence of the sense current magnetic field on the fluctuating magnetic field of the free magnetic layer is reduced. Therefore, the asymmetry can be reduced.

Here, the asymmetry indicates the degree of asymmetry of the reproduced output waveform. When a reproduced output waveform is given, if the waveform is symmetric, the asymmetry becomes smaller. Therefore, as the asymmetry approaches 0, the reproduced output waveform becomes more excellent in symmetry.

The asymmetry becomes 0 when the direction of the variable magnetization of the free magnetic layer is orthogonal to the direction of the fixed magnetization of the fixed magnetic layer. If the asymmetry deviates significantly, it will not be possible to read information from the medium accurately, causing an error. For this reason, the smaller the asymmetry, the higher the reliability of the reproduction signal processing, and the more excellent the spin valve thin film magnetic element becomes.

Further, in the present invention, the mean free path of the up-spin electrons contributing to the magnetoresistance effect is extended, and a large resistance change rate is obtained by the so-called spin filter effect.

When a sense current is applied to the spin-valve thin-film magnetic element, conduction electrons mainly move near the nonmagnetic material layer having a small electric resistance. Two kinds of electrons, up spin and down spin, are stochastically present in the conduction electrons.

The magnetoresistance ratio of the spin-valve thin-film magnetic element shows a positive correlation with the difference between the mean free paths of these two types of conduction electrons.

The down-spin conduction electrons are always scattered at the interface between the non-magnetic material layer and the free magnetic layer regardless of the direction of the applied external magnetic field, and the probability of moving to the free magnetic layer is kept low. , Its mean free path remains short compared to the mean free path of up-spin conduction electrons.

On the other hand, the up-spin conduction electrons have a probability of moving from the nonmagnetic material layer to the free magnetic layer when the magnetization direction of the free magnetic layer becomes parallel to the magnetization direction of the fixed magnetic layer due to an external magnetic field. And the mean free path is longer. On the other hand, as the magnetization direction of the free magnetic layer changes from a state parallel to the magnetization direction of the fixed magnetic layer due to the external magnetic field, the probability of scattering at the interface between the nonmagnetic material layer and the free magnetic layer increases, The mean free path of conduction electrons of up spin becomes shorter.

As described above, due to the action of the external magnetic field, the mean free path of the up-spin conduction electrons changes significantly compared to the mean free path of the down-spin conduction electrons, and the difference in the steps changes greatly. Then, the mean free path of the entire conduction electrons also changes greatly, and the magnetoresistance change rate (ΔR / R) of the spin-valve thin-film magnetic element increases.

Here, when the backed layer is connected to the free magnetic layer, the up-spin conduction electrons moving in the free magnetic layer can move into the backed layer, and the thickness of the backed layer is reduced. In proportion, the mean free path of up-spin conduction electrons can be further extended. For this reason, a so-called spin filter effect can be exhibited, and the difference in the mean free path of the conduction electrons increases, thereby further improving the magnetoresistance change rate (ΔR / R) of the spin-valve thin-film magnetic element. Can be.

Further, in the present invention, in the step (a), the multilayer film is formed as a laminate of a first antiferromagnetic layer, a fixed magnetic layer, a nonmagnetic material layer, and a free magnetic layer in this order from the substrate side. In the step (c), a lift-off resist layer having a cut portion formed on the lower surface is formed on the free magnetic layer, and the second antiferromagnetic layer is formed on the multilayer film. Alternatively, the resist layer may be removed from the multilayer film.

Further, after the second antiferromagnetic layer is formed, a pair of resists is laminated on the second antiferromagnetic layer at intervals of a track width, and a pair of resists is formed on the second antiferromagnetic layer. When the portion sandwiched by the resist is cut and removed in a direction perpendicular to the substrate surface, the track width of the thin-film magnetic element can be accurately defined.

Alternatively, in the step (c), after forming the second antiferromagnetic layer on the multilayer film, a pair of resists are laminated at intervals of a track width,
A concave portion may be formed by shaving a portion of the antiferromagnetic layer sandwiched by the resist in a direction perpendicular to the substrate surface.

In the present invention, the track width of the thin-film magnetic element is determined by the width of the recess. That is, the magnetization direction of the magnetic layer whose magnetization direction changes due to the external magnetic field such as the free magnetic layer can be changed only in the portion overlapping the bottom surface of the concave portion. In addition, the recess is formed by forming the second antiferromagnetic layer having a uniform thickness by reactive ion etching (RIE) or ion milling.
Since it can be formed only by shaving in the direction perpendicular to the surface of the non-magnetic layer, it is possible to form the recess with an accurate width dimension. That is, the track width of the thin-film magnetic element can be accurately defined.

In the present invention, the concave portion can be formed so that the bottom surface of the concave portion is located in the second antiferromagnetic layer.

At this time, the thickness of the region of the second antiferromagnetic layer located below the bottom surface of the recess, or the region of the second antiferromagnetic layer located below the bottom surface of the recess, and the other The total thickness of the regions of the antiferromagnetic layers of
In the following, the region of the second antiferromagnetic layer located below the bottom surface of the recess, or the region of the second antiferromagnetic layer located below the bottom surface of the recess, and the other antiferromagnetic layer This is preferable because no exchange coupling magnetic field is generated in the region of the layer.

Alternatively, the recess may be formed such that the bottom surface of the recess is located in the another antiferromagnetic layer.

At this time, the thickness of the region of the other antiferromagnetic layer located below the bottom surface of the concave portion is set to be larger than 0 and equal to 30.
The following is preferable because the exchange anisotropic magnetic field is not generated in the region of the other antiferromagnetic layer located below the bottom surface of the concave portion.

The concave portion may be formed such that the bottom surface of the concave portion is located in the nonmagnetic layer.

In the step (a), the fixed magnetic layer is formed by laminating a plurality of ferromagnetic material layers having different magnetic moments per unit area via a nonmagnetic intermediate layer. Is preferred.

When the pinned magnetic layer is formed by laminating a ferromagnetic material layer above and below a nonmagnetic intermediate layer, the plurality of ferromagnetic material layers fix their magnetization directions to each other, and as a whole the pinned magnetic layer is formed. The magnetization direction of the layer can be strongly fixed in a certain direction. That is, the exchange coupling magnetic field Hex between the first antiferromagnetic layer and the pinned magnetic layer is set to, for example, 80 to 160 k.
A / m, which can be obtained as a large value. Therefore,
After or before performing annealing in a magnetic field for directing the magnetization direction of the first antiferromagnetic layer in the height direction, annealing in a magnetic field for directing the magnetization direction of the second antiferromagnetic layer in the track width direction is performed. The longitudinal bias magnetic field by the second antiferromagnetic layer can be increased while preventing the magnetization direction of the fixed magnetic layer from being inclined and fixed in the track width direction.

Further, the demagnetizing field (dipole magnetic field) due to the fixed magnetization of the fixed magnetic layer can be canceled by canceling out the static magnetic field coupling of the plurality of ferromagnetic material layers. Thus, the contribution of the demagnetizing field (dipole magnetic field) due to the fixed magnetization of the fixed magnetic layer to the variable magnetization of the free magnetic layer can be reduced.

Accordingly, it is easier to correct the direction of the variable magnetization of the free magnetic layer to a desired direction, and it is possible to obtain a spin valve type thin film magnetic element having small asymmetry and excellent symmetry.

The demagnetizing field (dipole magnetic field) Hd due to the fixed magnetization of the fixed magnetic layer has a non-uniform distribution such that it is large at the end and small at the center in the element height direction.
Although the formation of a single magnetic domain in the free magnetic layer may be hindered, the dipole magnetic field Hd can be substantially set to Hd = 0 by forming the fixed magnetic layer to have the above-described laminated structure. It is possible to prevent the occurrence of nonuniform magnetization due to domain walls and Barkhausen noise or the like.

However, in the present invention, the fixed magnetic layer may be formed as a single ferromagnetic material layer.

In the step (a), the free magnetic layer may be formed by laminating a plurality of ferromagnetic material layers having different magnetic moments per unit area via a non-magnetic intermediate layer. preferable.

According to the present invention, the ferromagnetic state in which the magnetization directions of the adjacent ferromagnetic material layers via the nonmagnetic intermediate layer are antiparallel is brought about, and the same effect as reducing the thickness of the free magnetic layer is obtained. Is obtained because the magnetization of the free magnetic layer is likely to fluctuate and the magnetic field detection sensitivity of the magnetoresistive element is improved.

The magnitude of the magnetic moment per unit area of the ferromagnetic material layer is represented by the product of the saturation magnetization (Ms) and the thickness (t) of the ferromagnetic material layer.

The non-magnetic intermediate layer is formed of Ru, Rh,
It can be formed of one or more alloys of Ir, Cr, Re, and Cu.

In the present invention, it is preferable that at least one of the plurality of ferromagnetic material layers is formed of a magnetic material having the following composition.

The composition formula is represented by CoFeNi. The composition ratio of Fe is 9 to 17 atomic%, the composition ratio of Ni is 0.5 to 10 atomic%, and the remaining composition ratio is Co.

Further, it is preferable that an intermediate layer made of a CoFe alloy or Co is formed between the ferromagnetic material layer and the nonmagnetic material layer which are stacked closest to the nonmagnetic material layer. When forming the intermediate layer, it is preferable that at least one of the plurality of ferromagnetic material layers is formed of a magnetic material having the following composition.

The composition formula is represented by CoFeNi. The composition ratio of Fe is 7 to 15 atomic%, the composition ratio of Ni is 5 to 15 atomic%, and the remaining composition ratio is C
o.

Further, in the present invention, it is preferable that all of the plurality of ferromagnetic material layers are formed of the CoFeNi.

In the present invention, the free magnetic layer has a laminated ferrimagnetic structure, and a plurality of ferromagnetic material layers having different magnetic moments per unit area are laminated via a nonmagnetic intermediate layer. The ferromagnetic state is such that the magnetization directions of the adjacent ferromagnetic material layers via the intermediate layer are antiparallel.

In order to properly maintain the antiparallel magnetization state, it is necessary to improve the material of the free magnetic layer to increase the exchange coupling magnetic field in the RKKY interaction acting between the plurality of ferromagnetic material layers.

A NiFe alloy is often used as a magnetic material for forming the ferromagnetic material layer. NiFe
Alloys have been conventionally used for free magnetic layers and the like because of their excellent soft magnetic properties.However, when the free magnetic layer has a laminated ferrimagnetic structure, the antiparallel coupling force between ferromagnetic material layers formed of a NiFe alloy is not so large. Not strong.

Therefore, in the present invention, the material of the ferromagnetic material layer is improved, the antiparallel coupling force between the plurality of ferromagnetic material layers is increased, and both ends of the free magnetic layer located on both sides in the track width direction are formed. Since a CoFeNi alloy is used for at least one, and preferably all of the plurality of ferromagnetic material layers in order to prevent fluctuations in an external magnetic field and appropriately suppress the occurrence of side reading. is there. By containing Co, the above antiparallel coupling force can be strengthened.

FIG. 29 is a conceptual diagram of a hysteresis loop when the free magnetic layer has a laminated ferrimagnetic structure. For example, it is assumed that the magnetic moment per unit area of the first free magnetic layer (F1) (saturation magnetization Ms × film thickness t) is larger than the magnetic moment per unit area of the second free magnetic layer (F2). It is also assumed that an external magnetic field is applied in the right direction in the figure.

The vector sum of the magnetic moment per unit area of the first free magnetic layer and the magnetic moment per unit area of the second free magnetic layer (| Ms · t (F1) + Ms
The combined magnetic moment per unit area, which can be obtained from (t (F2) |), is constant from the zero magnetic field to a certain point even when the external magnetic field is increased. In the external magnetic field region A where the resultant magnetic moment is constant, the antiparallel coupling force acting between the first free magnetic layer and the second free magnetic layer is stronger than the external magnetic field.
The magnetizations of the first and second free magnetic layers are appropriately divided into single domains, and are maintained in an antiparallel state.

However, when the external magnetic field in the right direction in the figure is further increased, the combined magnetic moment per unit area of the free magnetic layer increases with an inclination angle. This is because the external magnetic field is stronger than the anti-parallel coupling force acting between the first free magnetic layer and the second free magnetic layer. The magnetization of the layer is dispersed to form a multi-domain state, and the resultant magnetic moment per unit area, which can be obtained by the vector sum, increases. In the external magnetic field region B where the combined magnetic moment per unit area increases, the antiparallel state of the free magnetic layer is no longer in a state of being collapsed. The magnitude of the external magnetic field at the starting point where the combined magnetic moment per unit area starts to increase is called a spin-flop magnetic field (Hsf).

When the external magnetic field in the right direction is further increased, the magnetizations of the first free magnetic layer and the second free magnetic layer are converted into single magnetic domains again. Magnetized to the right, this external magnetic field region C
Is a constant value per unit area. The magnitude of the external magnetic field when the combined magnetic moment per unit area becomes a constant value is called a saturation magnetic field (Hs).

In the present invention, the CoFeNi alloy is first
When used for the free magnetic layer and the second free magnetic layer, Ni
It has been found that the magnetic field when the antiparallel state collapses, that is, the so-called spin-flop magnetic field (Hsf) can be sufficiently increased as compared with the case where the Fe alloy is used.

In the present invention, an experiment for obtaining the magnitude of the above-mentioned spin-flop magnetic field using the NiFe alloy (Comparative Example) and the CoFeNi alloy (Example) for the first and second free magnetic layers was carried out by the following film configuration. This was performed using

Substrate / Nonmagnetic material layer (Cu) / First free magnetic layer (2.4) / Nonmagnetic intermediate layer (Ru) / Second free magnetic layer (1.4) The unit is nm.

For the first free magnetic layer and the second free magnetic layer in the comparative example, a NiFe alloy containing 80 atomic% of Ni and 20 atomic% of Fe was used. The spin-flop magnetic field (Hsf) at this time is about 59 (kA /
m).

Next, the first free magnetic layer and the second
In the free magnetic layer, the composition ratio of Co is 87 atomic% and Fe
A CoFeNi alloy having a composition ratio of 11 at% and a composition ratio of Ni of 2 at% was used. At this time, the spin-flop magnetic field (Hsf) was about 293 (kA / m).

As described above, the first free magnetic layer and the second free magnetic layer use CoFeNi rather than using a NiFe alloy.
It was found that the use of an alloy can effectively improve the spin-flop magnetic field.

Next, the composition ratio of the CoFeNi alloy will be described. The CoFeNi alloy has a non-magnetic intermediate layer R
It has been found that the magnetostriction shifts to the positive side by about 1 × 6 ^{−6 to} 6 × 10 ⁻⁶ by using the NiFe alloy in contact with the u layer.

The magnetostriction is preferably in the range of -3 × 10 ^-6 to 3 × 10 ^-6 . The coercive force is 790 (A
/ M) or less. When the magnetostriction is large, the magnetostriction is preferably low because the film is susceptible to stress due to film formation strain and a difference in thermal expansion coefficient between other layers. Further, the coercive force is preferably low, so that the magnetization reversal of the free magnetic layer with respect to an external magnetic field can be improved.

In the present invention, when formed in a film configuration of a nonmagnetic material layer / first free magnetic layer / nonmagnetic intermediate layer / second free magnetic layer, the Fe composition ratio of the CoFeNi is 9 atomic%.
Above, 17 atomic% or less, and the composition ratio of Ni is 0.5 atomic%.
Preferably, the content is 10 atomic% or less and the remaining composition ratio is Co. If the composition ratio of Fe is more than 17 atomic%, the magnetostriction becomes negative more than -3 × 10 ^-6 and the soft magnetic characteristics are deteriorated, which is not preferable.

If the composition ratio of Fe is less than 9 atomic%, the magnetostriction becomes larger than 3 × 10 ⁻⁶ and the soft magnetic characteristics are deteriorated, which is not preferable.

When the composition ratio of Ni is larger than 10 atomic%, the magnetostriction becomes larger than 3 × 10 ⁻⁶ ,
It is not preferable because the amount of change in resistance (ΔR) and the rate of change in resistance (ΔR / R) due to diffusion of Ni between the nonmagnetic material layer and the like are reduced.

If the composition ratio of Ni is smaller than 0.5 atomic%, the magnetostriction is undesirably larger than -3 × 10 ^-6 .

The coercive force can be reduced to 790 (A / m) or less within the above composition range.

Next, when an intermediate layer made of a CoFe alloy or Co is formed between the ferromagnetic material layer and the non-magnetic material layer stacked closest to the non-magnetic material layer, specifically, For example, a nonmagnetic material layer / intermediate layer (CoF
e alloy) / first free magnetic layer / non-magnetic intermediate layer / second free magnetic layer.
Has a Fe composition ratio of 7 atomic% or more and 15 atomic% or less,
Is preferably 5 atomic% or more and 15 atomic% or less, and the remaining composition ratio is preferably Co. Fe composition ratio is 15
If it is larger than atomic%, the magnetostriction becomes negative more than -3 × 10 ^-6 and the soft magnetic characteristics are deteriorated, which is not preferable.

If the composition ratio of Fe is smaller than 7 atomic%, the magnetostriction becomes larger than 3 × 10 ⁻⁶ and the soft magnetic characteristics are deteriorated.

If the composition ratio of Ni is larger than 15 atomic%, the magnetostriction is larger than 3 × 10 ^−6, which is not preferable.

If the composition ratio of Ni is smaller than 5 atomic%, the magnetostriction is undesirably larger than -3 × 10 ^-6 .

The coercive force can be reduced to 790 (A / m) or less within the above composition range.

Since the intermediate layer made of CoFe or Co has minus magnetostriction, the intermediate layer is made of CoFeNi as compared with the case where the intermediate layer is not interposed between the first free magnetic layer and the non-magnetic material layer. The Fe composition of the alloy is slightly reduced and the Ni composition is slightly increased.

As in the above-described film configuration, by interposing an intermediate layer made of a CoFe alloy or Co between the non-magnetic material layer and the first free magnetic layer, the metal between the first free magnetic layer and the non-magnetic material layer is formed. This is preferable because diffusion of elements can be more effectively prevented.

According to the present invention, even when the first antiferromagnetic layer and the second antiferromagnetic layer are formed using the same composition of antiferromagnetic material, the magnetization direction of the free magnetic layer is fixed to the fixed direction. It is easy to fix the magnetic layer in a direction perpendicular to the magnetization direction.

The first antiferromagnetic layer and / or the second antiferromagnetic layer is made of a PtMn alloy or X—Mn (where X is Pd, Ir, Rh, Ru, Ru, Os, Ni, Fe). Alloy of any one or two or more elements, or Pt—Mn—X ′ (where X ′ is Pd, Ir,
Rh, Ru, Au, Ag, Os, Cr, Ni, Ar, N
e, Xe, or Kr).

Here, the PtMn alloy and the XM
In the alloy represented by the formula of n, Pt or X is 37
It is preferably in the range of ~ 63 at%. Further, in the PtMn alloy and the alloy represented by the formula of X-Mn, Pt or X is more preferably in the range of 47 to 57 at%. Unless otherwise specified, the upper and lower limits of the numerical range indicated by mean below.

In the alloy represented by the formula of Pt-Mn-X ', X' + Pt is preferably in the range of 37 to 63 at%. In the alloy represented by the formula of Pt—Mn—X ′, X ′ + Pt is 47 to 57 at%.
More preferably, it is within the range. Further, the Pt-
In the alloy represented by the formula of Mn-X ', X' is 0.2
It is preferably in the range of 10 to 10 at%. However,
When X ′ is any one or more of Pd, Ir, Rh, Ru, Os, Ni, and Fe, X ′
Is preferably in the range of 0.2 to 40 at%.

As the first antiferromagnetic layer and the second antiferromagnetic layer, an alloy having an appropriate composition range is used, and the first antiferromagnetic layer generates a large exchange coupling magnetic field by heat treatment. And a second antiferromagnetic layer.
In particular, a PtMn alloy has an exchange coupling magnetic field of at least 48 kA / m, for example, more than 64 kA / m, and has an extremely high blocking temperature of 380 ° C. at which the exchange coupling magnetic field is lost. Two antiferromagnetic layers can be obtained.

These alloys have an irregular face-centered cubic structure (fcc) immediately after film formation, but are transformed into a CuAuI-type regular face-centered square structure (fct) by heat treatment.

In the present invention, the first antiferromagnetic layer and the longitudinal bias layer can be formed using the same composition of antiferromagnetic material.

[0104]

1 to 5 are sectional views showing an embodiment of a method for manufacturing a thin-film magnetic element according to the present invention.

First, the first antiferromagnetic layer 12 is laminated on the substrate 11. Further, a synthetic ferri-pinned fixed magnetic layer 13 including a first fixed magnetic layer 13a, a non-magnetic intermediate layer 13b, and a second fixed magnetic layer 13c is laminated, and a non-magnetic material layer 14, a free magnetic layer Layer 15,
The non-magnetic layer 16 and another antiferromagnetic layer 17 are stacked to form a multilayer film A. FIG. 1 is a cross-sectional view showing a state where the multilayer film A is formed.

The first antiferromagnetic layer 12, the pinned magnetic layer 13, the nonmagnetic material layer 14, the free magnetic layer 15, the nonmagnetic layer 16, and the other antiferromagnetic layer 17 are formed by a thin film forming process such as a sputtering method or a vapor deposition method. Formed by

First antiferromagnetic layer 12 and other antiferromagnetic layers 1
7 is a PtMn alloy or X-Mn (where X is
Pd, Ir, Rh, Ru, Os, Ni, Fe or any one or more of them) alloys or P
t-Mn-X '(where X' is Pd, Ir, Rh, R
u, Au, Ag, Os, Cr, Ni, Ar, Ne, X
e, or Kr).

First antiferromagnetic layer 12 and other antiferromagnetic layers 1
By using these alloys and performing heat treatment on them, the first antiferromagnetic layer 12 and another antiferromagnetic layer 17 that generate a large exchange coupling magnetic field can be obtained. In particular, if the alloy is a PtMn alloy, the first antiferromagnetic layer 12 has an exchange coupling magnetic field of 48 kA / m or more, for example, more than 64 kA / m, and has a very high blocking temperature of 380 ° C. at which the exchange coupling magnetic field is lost. Another antiferromagnetic layer 17 can be obtained.

These alloys have an irregular face-centered cubic structure (fcc) immediately after film formation, but are transformed into a CuAuI-type regular face-centered square structure (fct) by heat treatment.

The film thickness of the first antiferromagnetic layer 12 is 80 to 300 ° near the center in the track width direction. Also,
The thickness of the other antiferromagnetic layer 17 is about 30 °.

The first fixed magnetic layer 13a and the second fixed magnetic layer 13c are formed of a ferromagnetic material, for example, a NiFe alloy, Co, CoNiFe alloy, CoFe alloy, CoNi alloy, or the like. In particular, it is preferably formed of a NiFe alloy or Co. Preferably, the first pinned magnetic layer 13a and the second pinned magnetic layer 13c are formed of the same material.

The non-magnetic intermediate layer 13b is formed of a non-magnetic material, and is composed of Ru, Rh, Ir, Cr, R
e, Cu, or one or more of these alloys. In particular, it is preferably formed of Ru.

The non-magnetic material layer 14 prevents magnetic coupling between the pinned magnetic layer 13 and the free magnetic layer 15 and is a layer through which a sense current mainly flows, and is made of a conductive material such as Cu, Cr, Au, or Ag. Is preferably formed of a nonmagnetic material having In particular, it is preferably formed of Cu.

The free magnetic layer 15 is formed of a ferromagnetic material, for example, a NiFe alloy, Co, CoNi
It is formed of an Fe alloy, a CoFe alloy, a CoNi alloy, or the like, and is particularly preferably formed of a NiFe alloy or Co.

The non-magnetic layer 16 is formed of Ru,
The thickness is 8-11 °. The nonmagnetic layer is made of Ru, C
It can also be formed using one or more of u, Ag, and Au.

Next, the multilayer film A of FIG. 1 is annealed in a first magnetic field at a first heat treatment temperature and in a magnetic field of a first magnitude oriented in the Y direction to form a first antiferromagnetic layer 12. An exchange anisotropic magnetic field is generated to fix the magnetization direction of the fixed magnetic layer 13 to the Y direction in the figure. In this embodiment, the first heat treatment temperature is 270 ° C., and the first magnitude of the magnetic field is 800 k (A / A).
m).

Here, the thickness of the other antiferromagnetic layer 17 is 30
Å. If the thickness of the other antiferromagnetic layer 17 is 30 ° or less, even if the other antiferromagnetic layer 17 is annealed in a magnetic field, transformation from an irregular structure to a regular structure does not occur, and an exchange anisotropic magnetic field is generated. do not do. Therefore, when the multilayer film A is annealed in the first magnetic field, no exchange anisotropic magnetic field is generated in the other antiferromagnetic layers 17, and the magnetization direction of the free magnetic layer 15 is fixed in the Y direction in the drawing. Never.

When the multilayer film A is annealed in the first magnetic field, the other antiferromagnetic layer 17 is 10 to 2
Oxidates about 0 °. Therefore, the surface of the other antiferromagnetic layer 17 in the state of the multilayer film A is cut by about 20 ° by ion milling to remove the oxidized portion. As described above, in the present embodiment, since the other antiferromagnetic layer 16 is stacked on the uppermost layer of the multilayer film A, the oxidation of the nonmagnetic layer 16 and the free magnetic layer 15 can be prevented.

Next, as shown in FIG.
A vertical bias layer 18 as a second antiferromagnetic layer is formed, and an electrode layer 19 is formed on the vertical bias layer 18.

The vertical bias layer 18 comprises the first antiferromagnetic layer 12
And the other antiferromagnetic layer 17, a PtMn alloy or X—Mn (where X is Pd, Ir, Rh, Ru,
Alloys of one or more of Os, Ni, and Fe) or Pt—Mn—X ′ (where X ′ is Pd, Ir, Rh, Ru, Au, Ag, Os,
Cr, Ni, Ar, Ne, Xe, or Kr).

The thickness of the vertical bias layer 18 is about 80 to 300 °, for example, 200 ° near the center in the track width direction.
It is.

Here, in the PtMn alloy and the alloy represented by the formula X-Mn for forming the first antiferromagnetic layer 12, the other antiferromagnetic layer 17, and the longitudinal bias layer 18, Pt Alternatively, X is preferably in the range of 37 to 63 at%. Further, the PtMn alloy and the X
In the alloy represented by the formula -Mn, Pt or X is more preferably in the range of 47 to 57 at%. Unless otherwise specified, the upper and lower limits of the numerical range indicated by mean below.

In the alloy represented by the formula of Pt-Mn-X ', X' + Pt is preferably in the range of 37 to 63 at%. In the alloy represented by the formula of Pt—Mn—X ′, X ′ + Pt is 47 to 57 at%.
More preferably, it is within the range. Further, the Pt-
In the alloy represented by the formula of Mn-X ', X' is 0.2
It is preferably in the range of 10 to 10 at%. However,
When X ′ is any one or more of Pd, Ir, Rh, Ru, Os, Ni, and Fe, X ′
Is preferably in the range of 0.2 to 40 at%.

As the first antiferromagnetic layer and the second antiferromagnetic layer, an alloy having an appropriate composition range is used, and the first antiferromagnetic layer generates a large exchange coupling magnetic field by heat treatment. And a second antiferromagnetic layer.
In particular, a PtMn alloy has an exchange coupling magnetic field of at least 48 kA / m, for example, more than 64 kA / m, and has an extremely high blocking temperature of 380 ° C. at which the exchange coupling magnetic field is lost. Two antiferromagnetic layers can be obtained.

These alloys have an irregular face-centered cubic structure (fcc) immediately after film formation, but are transformed into a CuAuI-type regular face-centered square structure (fct) by heat treatment.

In the thin-film magnetic element of the present embodiment, the first antiferromagnetic layer 12 and the vertical bias layer 18 can be formed using the same composition of antiferromagnetic material.

The electrode layer 19 is made of, for example, Au, W, Cr,
The film is formed using Ta or the like. Next, as shown in FIG. 3, resists 20, 20 are laminated on the electrode layer 19, and the electrode layer 19 is masked at intervals of the track width Tw.

Further, as shown in FIG. 4, portions of the vertical bias layer 18 which are not masked by the resists 20 are ion-milled or reactive ion-etched (R).
The recess 21 is formed by cutting in a direction perpendicular to the surface 11a of the substrate 11 by IE) or the like. The side surfaces 21 a of the recess 21 are perpendicular to the surface 11 a of the substrate 11. In FIG. 4, the bottom surface 2 of the concave portion 21 is shown.
1b is located in the vertical bias layer 17,
Is formed.

At this time, the region of the vertical bias layer 18 located below the bottom surface 21b of the concave portion 21 and the other antiferromagnetic layer 17
Is set to be greater than 0 and 30 ° or less.

After the formation of the concave portion 21, the multilayer film B formed up to the electrode layers 19, 19 is annealed in a second magnetic field at a second heat treatment temperature and a second magnetic field oriented in the X direction. Then, an exchange anisotropic magnetic field is generated in the vertical bias layer 18 to fix the magnetization direction of the free magnetic layer 15 in the X direction in the drawing. In the present embodiment, the second heat treatment temperature is 250 ° C., and the second magnitude of the magnetic field is 24 k (A / m).

After the second heat treatment, the resist layers 20 and 2
By removing 0, a thin-film magnetic element as shown in FIG. 5 can be obtained.

The exchange anisotropic magnetic field of the longitudinal bias layer 18 is generated only in the second magnetic field annealing step. Accordingly, in order to direct the exchange anisotropic magnetic field of the longitudinal bias layer 18 in the illustrated X direction while the direction of the exchange anisotropic magnetic field of the first antiferromagnetic layer 12 is oriented in the illustrated Y direction, the second The heat treatment temperature is set lower than the blocking temperature at which the first antiferromagnetic layer 12 loses the exchange coupling magnetic field, and the magnitude of the second magnetic field is smaller than the exchange anisotropic magnetic field of the first antiferromagnetic layer 12. Just do it. If the second annealing in a magnetic field is performed under these conditions, the first antiferromagnetic layer 12 and the longitudinal bias layer 18 can be formed using the same antiferromagnetic material having the same composition. The exchange anisotropic magnetic field of the longitudinal bias layer 18 can be directed in the X direction in the drawing while the direction of the exchange anisotropic magnetic field of the layer 12 is directed in the Y direction in the drawing. That is, it becomes easy to fix the magnetization direction of the free magnetic layer 15 to a direction orthogonal to the magnetization direction of the fixed magnetic layer 13.

As in the present embodiment, the bottom surface 2
If the total thickness t1 of the region of the vertical bias layer 18 located below the lower portion 1b and the thickness of the other antiferromagnetic layer 17 is set to be larger than 0 and equal to or smaller than 30 °, the region of the vertical bias layer 18 located at the bottom surface 21b of the concave portion 21 In addition, no irregular-order transformation occurs due to annealing in the second magnetic field, and no exchange coupling magnetic field is generated.

That is, the magnetization direction of the free magnetic layer 15 is fixed by exchange coupling with the vertical bias layer 18 only at both ends D, D in the track width direction other than the region overlapping the bottom surface 21b of the concave portion 21.

The region E of the free magnetic layer 15 overlapping the bottom surface 21b of the concave portion 21 follows both ends D, D whose magnetization directions are fixed by exchange coupling with the vertical bias layer 18 in a state where no external magnetic field is applied. The direction of magnetization is aligned in the illustrated X direction, and when an external magnetic field is applied, its magnetization direction changes.

Therefore, the track width of the thin-film magnetic element is determined by the width Tw of the recess. As described above, in the present invention, the concave portion 21 is formed by forming the longitudinal bias layer 18 formed with a uniform thickness by reactive ion etching (RIE).
Or ion milling, and can be formed only by shaving in the direction perpendicular to the surface 11a of the substrate 11,
The concave portion 21 can be formed with an accurate width Tw. That is, the track width Tw of the thin-film magnetic element can be accurately defined.

In the above description, after the electrode layer 19 is formed on the vertical bias layer 18, the resist is laminated on the electrode layer 19 to form a recess in the vertical bias layer 18. After the resists 20 and 20 are laminated on the upper layer 18 and the concave portion is formed on the vertical bias layer 18, the electrode layer 19 may be laminated on the vertical bias layer 18.

In this embodiment, the first antiferromagnetic layer 12 is directly laminated on the substrate 11, but the antiferromagnetic layer is formed on the substrate 11 with an alumina layer and an underlayer made of Ta or the like interposed therebetween. 12 may be stacked.

The thin-film magnetic element formed by the method for manufacturing a thin-film magnetic element of the present embodiment shown in FIG. 5 will be described.

When the vertical bias layer 18 is laminated on the multilayer film A via the non-magnetic layer 16, the free magnetic layer 15
The magnetization directions are aligned by the RKKY interaction with the vertical bias layer 18. The RKKY interaction acts only with the region of the magnetic layer located immediately below the antiferromagnetic layer having the antiferromagnetic thickness (longitudinal bias layer 18), and has the antiferromagnetic thickness of the antiferromagnetic layer. It does not act on a region deviating from immediately below the magnetic layer. That is, the RKKY interaction is caused by the depression 21
, Both ends D, D in the track width direction not overlapping the bottom surface 21b of the
And does not act on the region E overlapping the bottom surface 21b of the concave portion 21.

Therefore, the area of the track width (optical track width) Tw set as the width dimension of the concave portion 21 formed in the vertical bias layer 18 substantially contributes to the reproduction of the recording magnetic field, and reduces the magnetoresistance effect. This is the sensitivity range to be exhibited. In other words, the thin-film magnetic element of the present invention has an optical track width equal to the magnetic track width, and thus has a dead area. Therefore, it is easy to cope with the increase in the recording density of the recording medium.

Further, since there is no dead area in the area of the track width (optical track width) Tw set at the time of forming the thin-film magnetic element, the optical track width of the thin-film magnetic element can be increased in order to cope with high recording density. A decrease in the reproduction output when Tw is reduced can be suppressed.

Further, in this embodiment, since the side end surfaces S, S of the thin-film magnetic element can be formed so as to be perpendicular to the surface 11a of the substrate 11, the free magnetic layer 1
5 can be suppressed from varying in the width direction.

As in the present embodiment, the free magnetic layer 15 is formed by the RKKY interaction with the vertical bias layer 18.
When the magnetization directions are uniform, the exchange coupling force can be made stronger than that in which the vertical bias layer 18 and the free magnetic layer 15 are in direct contact.

Further, as in the present embodiment, the non-magnetic layer 1
6 is made of a conductive material, the non-magnetic layer 1
6 is a backed layer (bac) having a spin filter effect.
function as a keylayer).

When the backed layer (nonmagnetic layer 16) having the spin filter effect is provided in contact with the free magnetic layer 15, the center height position at which the sense current flows inside the stacked body is set to be larger than when the backed layer is not provided. It can be moved to the backed layer side. That is, the center height position of the sense current is separated from the free magnetic layer 15, the intensity of the sense current magnetic field at the position of the free magnetic layer 15 is reduced, and the influence of the sense current magnetic field on the variable magnetization of the free magnetic layer 15 is reduced. . Therefore, the asymmetry can be reduced.

Here, the asymmetry indicates the degree of asymmetry of the reproduced output waveform. When a reproduced output waveform is given, if the waveform is symmetric, the asymmetry becomes smaller. Therefore, as the asymmetry approaches 0, the reproduced output waveform becomes more excellent in symmetry.

The asymmetry becomes 0 when the direction of the variable magnetization of the free magnetic layer is orthogonal to the direction of the fixed magnetization of the fixed magnetic layer. If the asymmetry deviates significantly, it will not be possible to read information from the medium accurately, causing an error. For this reason, the smaller the asymmetry, the higher the reliability of the reproduction signal processing, and the more excellent the spin valve thin film magnetic element becomes.

Next, the spin filter effect will be described.
30 and 31 are schematic diagrams for explaining the spin filter effect of the backed layer in the spin-valve thin-film magnetic element. FIG. 30 is a schematic diagram showing an example of a structure without a backed layer, and FIG. It is a schematic diagram which shows the structural example with a layer.

The giant magnetoresistance GMR effect is mainly due to “spin-dependent scattering” of electrons. In other words, the mean free path λ ⁻ of conduction electrons having a spin (for example, up spin) parallel to the magnetization direction of the magnetic material, here, the free magnetic layer, and the conduction electron having a spin (for example, down spin) antiparallel to the magnetization direction. it is obtained by using the difference of ^- the mean free path λ. 30 and 31, conduction electrons having up spin are represented by upward arrows, and conduction electrons having down spin are represented by downward arrows. When electrons try to pass through the free magnetic layer, they can move freely if they have an up spin parallel to the magnetization direction of the free magnetic layer, but if they have a down spin, they are immediately scattered.

This is because the mean free path λ ⁺ of an electron having an up spin is about 50 Å, for example, while the mean free path λ− of an electron having a down spin is about 6 Å. This is because it is extremely small, about one-half. The thickness of the free magnetic layer 115 is set to be larger than the mean free path λ ^{− of} electrons having a down spin of about 6 Å and smaller than the mean free path λ ^{+ of} electrons having an up spin of about 50 Å. ing.

Therefore, when electrons try to pass through the free magnetic layer 115, the electrons are
It can move freely if it has an upspin parallel to the magnetization direction, but if it has a downspin, it is immediately scattered (filtered out).

The down-spin electrons generated in the fixed magnetic layer 113 laminated on the antiferromagnetic layer 112 and passing through the nonmagnetic material layer 114 are transferred to the free magnetic layer 115 and the nonmagnetic material layer 1.
The light is scattered near the interface with the free magnetic layer 14 and hardly reaches the free magnetic layer 115. That is, even if the magnetization direction of the free magnetic layer 115 rotates, the down-spin electrons do not change the mean free path, and do not affect the resistance change rate due to the GMR effect. Therefore, only the behavior of up-spin electrons needs to be considered for the GMR effect.

The up-spin electrons generated in the pinned magnetic layer 113 move through the nonmagnetic material layer 114 having a thickness smaller than the mean free path λ ^{+ of} the up-spin electrons, reach the free magnetic layer 115, and Is the free magnetic layer 11
5 can pass freely. This is because the up-spin electrons have a spin parallel to the magnetization direction of the free magnetic layer 115.

When the magnetization direction of the pinned magnetic layer and the magnetization direction of the free magnetic layer are antiparallel, the up-spin electrons are not electrons having a spin parallel to the magnetization direction of the free magnetic layer 115. Then, the up-spin electrons are scattered near the interface between the free magnetic layer 115 and the non-magnetic material layer 114, and the effective mean free path of the up-spin electrons sharply decreases. That is, the resistance value increases. The resistance change rate has a positive correlation with the change amount of the effective mean free path of the up-spin electrons.

As shown in FIG. 31, when the back layer B _A is provided, the up-spin electrons that have passed through the free magnetic layer 115 are determined by the material of the back layer B 1 in the back layer B _A. Additional mean free path λ ⁺ b
Scatter after moving. That is, by providing the backed layer B _A , the mean free path λ ⁺
Is extended by an additional mean free path λ ⁺ b.

In this embodiment having the nonmagnetic layer 16 functioning as a backed layer, the mean free path of up-spin conduction electrons can be extended. For this reason, the amount of change in the mean free path of up-spin electrons due to the application of an external magnetic field is increased, and the magnetoresistance ratio (ΔR / R) of the spin-valve thin-film magnetic element can be further improved.

In this embodiment, the other antiferromagnetic layer 17 can be formed as a specular reflection layer. In order to form another antiferromagnetic layer 17 as a specular reflection layer, the other antiferromagnetic layer 17 is made of, for example, NiMnSb, Pt.
It may be formed as a single-layer film or a multilayer film of a semi-metallic Whistler alloy such as MnSb.

By using these materials, it is possible to form a sufficient potential barrier between adjacent layers, and as a result, a sufficient specular reflection effect can be obtained.

The specular reflection effect will be described. FIGS. 32 and 33 are schematic diagrams for explaining the specular reflection effect of the specular reflection layer S1 in the spin-valve thin-film magnetic element. As described above in the description of the spin filter effect, only the behavior of the up-spin electrons defined by the fixed magnetization direction of the fixed magnetic layer 113 needs to be considered in the GMR effect.

When the magnetization direction of the pinned magnetic layer is parallel to the magnetization direction of the free magnetic layer, as shown in FIGS. 32 and 33, up-spin electrons are transferred from the nonmagnetic material layer 114 to the free magnetic layer 115. To reach. Then, it moves inside the free magnetic layer 115 and reaches near the interface between the free magnetic layer 115 and the specular reflection layer S1.

Here, when there is no mirror reflection layer shown in FIG. 32, up-spin electrons move in the free magnetic layer 115 and are scattered on the upper surface thereof. Therefore, the mean free path is λ ⁺ shown in the figure.

On the other hand, as shown in FIG. 33, when there is the specular reflection layer S1, a potential barrier is formed near the interface between the free magnetic layer 115 and the specular reflection layer S1, so that the up-spin electrons are transferred to the free magnetic layer S1. Specular reflection (mirror scattering) occurs near the interface between 115 and the specular reflection layer S1.

Normally, when a conduction electron is scattered, the spin state (energy, quantum state, etc.) of the electron changes. However, when specular scattering occurs, the up-spin electrons have a high probability of being reflected while the spin state is preserved, and move through the free magnetic layer 115 again. In other words, the spin state of the up-spin conduction electrons is maintained by specular reflection, so that the electrons move in the free magnetic layer as if they were not scattered.

This means that the mean free path is extended by the reflection mean free path λ ⁺ s due to the specular reflection of the up-spin electrons.

When the magnetization direction of the pinned magnetic layer and the magnetization direction of the free magnetic layer are antiparallel, the up-spin electrons are no longer electrons having a spin parallel to the magnetization direction of the free magnetic layer 115. Then, the up-spin electrons are scattered near the interface between the free magnetic layer 115 and the non-magnetic material layer 114, and the effective mean free path of the up-spin electrons sharply decreases. That is, the resistance value increases. The resistance change rate has a positive correlation with the change amount of the effective mean free path of the up-spin electrons.

In this embodiment having another antiferromagnetic layer 17 functioning as a specular reflection layer, the mean free path of up-spin conduction electrons can be extended. For this reason, the amount of change in the mean free path of up-spin electrons due to the application of an external magnetic field is increased, and the magnetoresistance ratio (ΔR / R) of the spin-valve thin-film magnetic element can be further improved.

The increase in the mean free path difference between the up-spin conduction electrons and the down-spin conduction electrons due to the spin filter effect and the specular reflection effect is more effective when the thickness of the free magnetic layer is relatively small.

If the thickness of the free magnetic layer 115 is less than 15 °, it is difficult to form the free magnetic layer 115 so as to function as a ferromagnetic material layer, and a sufficient magnetoresistance effect cannot be obtained.

The thickness of the free magnetic layer 115 is 45 °.
If the thickness is larger, the number of up-spin conduction electrons that are scattered before reaching the specular reflection layer is increased, and the rate of change in the resistance change rate due to the specular effect is not preferable.

In FIG. 5, the first fixed magnetic layer 13a and the second fixed magnetic layer 13a having different magnetic moments per unit area are shown.
A layer in which the fixed magnetic layer 13c is stacked via the nonmagnetic intermediate layer 13b functions as one fixed magnetic layer 13.

The first pinned magnetic layer 13a is the first antiferromagnetic layer 1
2 and subjected to annealing in a magnetic field, an exchange anisotropic magnetic field is generated by exchange coupling at the interface between the first pinned magnetic layer 13a and the antiferromagnetic layer 12, and the first pinned magnetic layer The magnetization direction of 13a is fixed in the illustrated Y direction. First
When the magnetization direction of the fixed magnetic layer 13a is fixed in the Y direction in the figure, the magnetization direction of the second fixed magnetic layer 13c opposed via the nonmagnetic intermediate layer 13b is antiparallel to the magnetization direction of the first fixed magnetic layer 13a. Is fixed in the state of.

The direction of the combined magnetic moment per unit area obtained by adding the magnetic moment per unit area of the first fixed magnetic layer 13a and the magnetic moment per unit area of the second fixed magnetic layer 13c is Magnetization direction.

As described above, the first pinned magnetic layer 13a and the second
The magnetization direction of the pinned magnetic layer 13c is in an antiparallel ferrimagnetic state, and the first pinned magnetic layer 13a and the second pinned magnetic layer 13c fix the other magnetization direction to each other. This is preferable because the magnetization direction of the magnetic layer 13 can be stabilized in a certain direction.

The first fixed magnetic layer 13a and the second fixed magnetic layer 13c are formed of a ferromagnetic material, for example, a NiFe alloy, Co, CoNiFe alloy, CoFe alloy, CoNi alloy, or the like. In particular, it is preferably formed of a NiFe alloy or Co. Preferably, the first pinned magnetic layer 13a and the second pinned magnetic layer 13c are formed of the same material.

In FIG. 5, the first fixed magnetic layer 13a and the second fixed magnetic layer 13c are formed using the same material,
Further, the magnetic moment per unit area is made different by making the thickness different.

The non-magnetic intermediate layer 13b is formed of a non-magnetic material, and is composed of Ru, Rh, Ir, Cr, R
e, Cu, or one or more of these alloys. In particular, it is preferably formed of Ru.

When the fixed magnetic layer 13 is formed by laminating the first fixed magnetic layer 13a and the second fixed magnetic layer 13b on the upper and lower sides of the nonmagnetic intermediate layer 13b, the first fixed magnetic layer 1
3a and the second pinned magnetic layer 13c fix the magnetization directions of each other, so that the magnetization direction of the pinned magnetic layer 13 can be strongly fixed as a whole in a fixed direction. That is, the exchange coupling magnetic field Hex between the first antiferromagnetic layer 12 and the fixed magnetic layer 13 can be obtained as a large value, for example, 80 to 160 kA / m. Therefore, after annealing in the first magnetic field for directing the magnetization direction of the first antiferromagnetic layer 12 to the height direction, the second magnetic field for directing the magnetization direction of the vertical bias layer 18 to the track width direction is used. Medium annealing can increase the longitudinal bias magnetic field generated by the longitudinal bias layer 18 while preventing the magnetization direction of the fixed magnetic layer 13 from being fixed in the track width direction.

In the present embodiment, the fixed magnetic layer 13
The demagnetizing field (dipole magnetic field) due to the fixed magnetization described above can be canceled by the mutual cancellation of the static magnetic field coupling between the first fixed magnetic layer 13a and the second fixed magnetic layer 13c. Thereby, the contribution of the demagnetizing field (dipole magnetic field) due to the fixed magnetization of the fixed magnetic layer 13 to the variable magnetization of the free magnetic layer 15 can be reduced.

Therefore, it is easier to correct the direction of the fluctuating magnetization of the free magnetic layer 15 to a desired direction, and it is possible to obtain a spin valve type thin film magnetic element with small asymmetry and excellent symmetry.

The demagnetizing field (dipole magnetic field) Hd due to the fixed magnetization of the fixed magnetic layer 13 has a non-uniform distribution such that it is large at the end and small at the center in the element height direction. Although the formation of a single magnetic domain in the magnetic field may be hindered, the dipole magnetic field Hd can be substantially set to Hd = 0 by forming the fixed magnetic layer 13 in the above-described laminated structure. As a result, non-uniform magnetization and Barkhausen noise can be prevented.

FIG. 6 is a sectional view of a thin-film magnetic element formed according to the second embodiment of the present invention as viewed from the ABS side.

The method of manufacturing this thin-film magnetic element is almost the same as that of the first embodiment shown in FIGS. 1 to 5, and in FIG.
The portion sandwiched between the substrates 20 is subjected to ion milling or reactive ion etching (RIE), and the like.
The only difference is that the concave portion 21 is formed such that the bottom surface 21b of the concave portion 21 is located in the other antiferromagnetic layer 17 when it is cut in the direction perpendicular to the surface 11a.

In the present embodiment, the thickness t2 of the region of the other antiferromagnetic layer 17 located below the bottom surface 21b of the recess 21 is set to be larger than 0 and 30 ° or less, and Irregular-order transformation caused by annealing in a magnetic field is not caused in the region of the other antiferromagnetic layer 17 located, so that no exchange coupling magnetic field is generated.

Thus, the magnetization direction of the free magnetic layer 15 is
Only at both ends D, D in the track width direction other than the region located below the bottom surface 21 b of the concave portion 21, it is fixed by RKKY coupling with the vertical bias layer 18.

The bottom surface 21b of the concave portion 21 of the free magnetic layer 15
In the state where no external magnetic field is applied, a region E located below the bottom surface is aligned in the X direction in the drawing along both ends D and D whose magnetization directions are fixed by RKKY coupling with the longitudinal bias layer 18. Is applied, the magnetization direction changes. Therefore, the track width of the thin-film magnetic element is determined by the width Tw of the concave portion.

The bottom surface 21b of the recess 21 is formed of another antiferromagnetic layer 1
7, the magnetization direction of the free magnetic layer 15 is fixed in a direction orthogonal to the magnetization direction of the fixed magnetic layer 13 in the same manner as in the first embodiment. And the track width Tw of the thin-film magnetic element can be accurately defined. Further, even if the first antiferromagnetic layer 12 and the longitudinal bias layer 18 are formed using the same composition of antiferromagnetic material, the direction of the exchange anisotropic magnetic field of the first antiferromagnetic layer 12 is set in the Y direction in the drawing. The exchange anisotropic magnetic field of the vertical bias layer 18 can be directed in the X direction in the drawing while keeping the orientation.

The thin-film magnetic element shown in FIG. 6 has the same effects as those of the thin-film magnetic element formed by the first embodiment shown in FIG. The same effect as can be obtained.

FIG. 7 is a sectional view of a thin-film magnetic element formed according to the third embodiment of the present invention, as viewed from the ABS side.

The method of manufacturing this thin-film magnetic element is almost the same as that of the first embodiment shown in FIGS. 1 to 5, and in FIG.
The portion sandwiched between the substrates 20 is subjected to ion milling or reactive ion etching (RIE), and the like.
The only difference is that the concave portion 21 is formed so that the bottom surface 21b of the concave portion 21 is located in the nonmagnetic layer 16 when the first surface 11a is cut in the vertical direction.

In the present embodiment, the magnetization direction of the free magnetic layer 15 is fixed by RKKY coupling with the vertical bias layer 18 only at both ends D and D in the track width direction other than the portion overlapping the bottom surface 21b of the recess 21. You.

The bottom surface 21b of the concave portion 21 of the free magnetic layer 15
Are aligned in the X direction in the drawing along with both ends D and D whose magnetization directions are fixed by RKKY coupling with the vertical bias layer 18 in a state where no external magnetic field is applied, and an external magnetic field is applied. Then, the magnetization direction changes. Therefore, the track width of the thin-film magnetic element is determined by the width Tw of the concave portion.

In the manufacturing method in which the concave portion 21 is formed such that the bottom surface 21 b of the concave portion 21 is located in the nonmagnetic layer 16, the magnetization direction of the free magnetic layer 15 is fixed in a direction orthogonal to the magnetization direction of the fixed magnetic layer 13. And the track width Tw of the thin-film magnetic element can be accurately defined. Also, the first
Even if the antiferromagnetic layer 12 and the longitudinal bias layer 18 are formed using the same composition of antiferromagnetic material, the direction of the exchange anisotropic magnetic field of the first antiferromagnetic layer 12 is kept in the Y direction in the drawing. The exchange anisotropic magnetic field of the vertical bias layer 18 can be directed in the X direction in the figure.

The thin-film magnetic element shown in FIG. 7 is different from the thin-film magnetic element shown in FIG. 5 in that the thin-film magnetic element formed by the first embodiment shown in FIG. The same effect as can be obtained.

FIG. 8 is a sectional view of a thin-film magnetic element formed according to the fourth embodiment of the present invention as viewed from the ABS side.

The method of manufacturing this thin-film magnetic element is almost the same as that of the first embodiment shown in FIGS.

The difference from the first embodiment is that in FIG. 1, after the free magnetic layer 15 is formed, the nonmagnetic layer 16 is not laminated, and another antiferromagnetic layer 17 is formed on the free magnetic layer 15. Is formed, a multilayer film A1 is formed by directly laminating the layers, the multilayer film A1 is annealed in a first magnetic field, and then a vertical bias layer 18 is laminated on the multilayer film A1.

The thin-film magnetic element shown in FIG.
Since the other antiferromagnetic layer 17 and the vertical bias layer 18 as the second antiferromagnetic layer are stacked on the upper layer, the magnetization direction of the free magnetic layer 15 is different from that of the other antiferromagnetic layer 17 and the vertical bias layer. 18 are aligned in the X direction in the figure by exchange coupling.

In the present embodiment, the bottom surface 21b of the concave portion 21
The total t4 of the thickness of the region of the vertical bias layer 18 located under the layer and the thickness of the other antiferromagnetic layer 17 is set to be larger than 0 and
In the region of the vertical bias layer 18 and the other antiferromagnetic layer 17 located below the bottom surface 21b of the concave portion 21, no irregular-order transformation occurs due to the annealing in the second magnetic field, and the exchange coupling magnetic field does not occur. Does not occur.

That is, the magnetization direction of the free magnetic layer 15 is only at the both ends D, D in the track width direction other than the region located below the bottom surface 21b of the concave portion 21, and the vertical bias layer 18
Fixed by exchange coupling with

The bottom surface 21b of the concave portion 21 of the free magnetic layer 15
In the state where no external magnetic field is applied, the region E located below the lower portion is aligned in the X direction in the drawing along both ends D and D whose magnetization directions are fixed by exchange coupling with the longitudinal bias layer 18. Is applied, the magnetization direction changes.

Accordingly, the track width of the thin-film magnetic element is determined by the width Tw of the recess. As described above, in the present invention, the concave portion 21 is formed so that the vertical bias layer formed with a uniform thickness is formed in a direction perpendicular to the surface 11a of the substrate 11 by using reactive ion etching (RIE) or ion milling. Since it can be formed only by shaving, it is possible to form the concave portion 21 with an accurate width Tw.
That is, the track width of the thin-film magnetic element can be accurately defined.

After the formation of the free magnetic layer 15, the nonmagnetic layer 16
Also in the manufacturing method in which another antiferromagnetic layer 17 is stacked without stacking, the magnetization direction of the free magnetic layer 15 can be easily fixed in a direction orthogonal to the magnetization direction of the fixed magnetic layer 13.

Even if the first antiferromagnetic layer 12 and the longitudinal bias layer 18 are formed using the same composition of the antiferromagnetic material, the first antiferromagnetic layer 12 and the vertical bias layer 18 are formed in the same manner as in the first embodiment. The exchange anisotropic magnetic field of the longitudinal bias layer 18 can be directed in the X direction in the figure while the direction of the exchange anisotropic magnetic field in the direction of FIG.

The thin-film magnetic element shown in FIG. 8 has the same effects as those of the thin-film magnetic element formed according to the first embodiment shown in FIG. The same effect as that of the thin film magnetic element can be obtained.

FIG. 9 is a sectional view of a thin-film magnetic element formed according to the fifth embodiment of the present invention as viewed from the ABS side.

The method of manufacturing this thin-film magnetic element is almost the same as that of the fourth embodiment. The portion of the vertical bias layer 18 sandwiched between the resists 20 is ion-milled or reactive ion-etched (RIE). ), The bottom surface 21b of the concave portion 21 may be removed from the other antiferromagnetic layer 1
7 only in that a concave portion 21 is formed so as to be located in 7.

In the present embodiment, the thickness t5 of the region of the other antiferromagnetic layer 17 located below the bottom surface 21b of the recess 21 is set to be larger than 0 and 30 ° or less, and Irregular-order transformation caused by annealing in a magnetic field is not caused in the region of the other antiferromagnetic layer 17 located, so that no exchange coupling magnetic field is generated.

Thus, the magnetization direction of the free magnetic layer 15 is
Only at both ends D, D in the track width direction other than the region overlapping with the bottom surface 21b of the concave portion 21, it is fixed by exchange coupling with the vertical bias layer 18.

The bottom surface 21b of the concave portion 21 of the free magnetic layer 15
In the state where no external magnetic field is applied, a region E located below the lower end is aligned in the X direction in the drawing along both ends D and D whose magnetization directions are fixed by exchange coupling with the vertical bias layer 18. Is applied, the magnetization direction changes. Therefore, the track width of the thin-film magnetic element is determined by the width Tw of the concave portion.

The concave portion 21 is formed by merely shaving the vertical bias layer formed with a uniform thickness in a direction perpendicular to the surface 11a of the substrate 11 by using reactive ion etching (RIE) or ion milling. Therefore, it is possible to form the concave portion 21 with an accurate width dimension Tw. That is, the track width of the thin-film magnetic element can be accurately defined.

The bottom surface 21b of the recess 21 is formed of another antiferromagnetic layer 1
7, the magnetization direction of the free magnetic layer 15 is fixed in a direction orthogonal to the magnetization direction of the fixed magnetic layer 13 in the same manner as in the fourth embodiment. And the track width Tw of the thin-film magnetic element can be accurately defined. Further, even if the first antiferromagnetic layer 12 and the longitudinal bias layer 18 are formed using the same composition of antiferromagnetic material, the direction of the exchange anisotropic magnetic field of the first antiferromagnetic layer 12 is set in the Y direction in the drawing. The exchange anisotropic magnetic field of the vertical bias layer 18 can be directed in the X direction in the drawing while keeping the orientation.

The thin-film magnetic element shown in FIG. 9 is different from the thin-film magnetic element shown in FIG. 8 in the other effects of the thin-film magnetic element formed by the fourth embodiment shown in FIG. The same effect as can be obtained.

FIG. 10 is a sectional view of a thin-film magnetic element formed according to the sixth embodiment of the present invention as viewed from the ABS side.

The method of manufacturing this thin-film magnetic element is almost the same as that of the first embodiment shown in FIGS. 1 to 5. In FIG. 1, the free magnetic layer 31 is provided with a magnetic moment per unit area. The first free magnetic layer 31a and the second free magnetic layer 31c differing in the size of the non-magnetic intermediate layer 31
The only difference is that the magnetic layer is formed as a so-called synthetic ferri-free type free magnetic layer laminated through the layers b.

The first free magnetic layer 31a and the second free magnetic layer 31c are formed of a ferromagnetic material, for example, NiFe alloy, Co, CoNiFe alloy, CoFe
Alloy, a CoNi alloy or the like,
In particular, it is preferably formed of a NiFe alloy.

The non-magnetic intermediate layer 31b is formed of a non-magnetic material, and is composed of Ru, Rh, Ir, Cr, R
It is formed of one or more alloys of e and Cu. In particular, it is preferably formed of Ru.

Note that a diffusion preventing layer made of Co or the like may be formed between the first free magnetic layer 31a and the nonmagnetic material layer. This diffusion preventing layer is the first free magnetic layer 3
1a and the non-magnetic material layer 14 are prevented from interdiffusion.

The first free magnetic layer 31a and the second free magnetic layer 31c are formed so that the respective magnetic moments per unit area are different. The magnetic moment per unit area is represented by the product of the saturation magnetization (Ms) and the film thickness (t). Therefore, for example, the first free magnetic layer 31a and the second free magnetic layer 31c are formed by using the same material, and the thicknesses of the first free magnetic layer 31a and the second free magnetic layer 31c are changed. The magnetic moment per unit area of 31c can be made different.

When a diffusion preventing layer made of Co or the like is formed between the first free magnetic layer 31a and the nonmagnetic material layer 14, the magnetic moment per unit area of the first free magnetic layer 31a is reduced. It is preferable that the sum of the magnetic moment per unit area of the diffusion prevention layer and the magnetic moment per unit area of the second free magnetic layer 31c be different.

Note that the thickness tf of the second free magnetic layer 31c is
2 is preferably in the range of 0.5 to 2.5 nm.
Further, the thickness tf1 of the first free magnetic layer 31a is 2.5 to
It is preferably in the range of 4.5 nm. Note that the thickness tf1 of the first free magnetic layer 31a is more preferably in the range of 3.0 to 4.0 nm, and still more preferably 3.0.
The range is 5 to 4.0 nm. If the thickness tf1 of the first free magnetic layer 31a is out of the above range, the rate of change in magnetoresistance of the spin-valve thin-film magnetic element cannot be increased, which is not preferable.

In FIG. 10, one free magnetic layer 31a in which a first free magnetic layer 31a and a second free magnetic layer 31c having different magnetic moments per unit area are stacked via a non-magnetic intermediate layer 31b is shown. Function as

The magnetization directions of the first free magnetic layer 31a and the second free magnetic layer 31c are in antiparallel ferrimagnetic states different by 180 degrees. At this time, the magnetic moment per unit area is larger, for example, the first free magnetic layer 31.
a is oriented in the direction of the magnetic field generated from the vertical bias layer 18, and the magnetization direction of the second free magnetic layer 31c is set to 1
It will be in the opposite direction by 80 degrees.

When the first free magnetic layer 31a and the second free magnetic layer 31c are in an antiparallel ferrimagnetic state in which the magnetization directions are different by 180 degrees, an effect equivalent to reducing the thickness of the free magnetic layer 31 can be obtained. As a result, the saturation magnetization decreases, the magnetization of the free magnetic layer 31 tends to fluctuate, and the magnetic field detection sensitivity of the magnetoresistance effect element improves.

The direction of the combined magnetic moment per unit area obtained by adding the magnetic moment per unit area of the first free magnetic layer 31a and the magnetic moment per unit area of the second free magnetic layer 31c is the magnetization of the free magnetic layer 31. Direction.

However, only the magnetization direction of the first free magnetic layer 31a contributes to the output in relation to the magnetization direction of the fixed magnetic layer 13.

If the relationship between the magnetic film thicknesses of the first free magnetic layer and the second free magnetic layer is different, the spin flop magnetic field of the free magnetic layer 31 can be increased.

The spin flop magnetic field means the magnitude of an external magnetic field in which 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. 29 is a conceptual diagram of a hysteresis loop of the free magnetic layer 31. This MH curve shows a change in the magnetization M of the free magnetic layer when an external magnetic field is applied to the free magnetic layer having the configuration shown in FIG. 10 in the track width direction.

In FIG. 29, the arrow indicated by F1 is the first arrow.
The direction of magnetization of the free magnetic layer is indicated by an arrow F2.
Indicates the magnetization direction of the second free magnetic layer.

As shown in FIG. 29, when the external magnetic field is small, the first free magnetic layer and the second free magnetic layer are in a ferrimagnetic state, that is, the directions of arrows F1 and F2 are antiparallel. When the magnitude of the magnetic field H exceeds a certain value,
The RKKY bond between the first free magnetic layer and the second free magnetic layer is broken, and the ferrimagnetic state cannot be maintained. This is a spin-flop transition. The magnitude of the external magnetic field when the spin-flop transition occurs is the spin-flop magnetic field, and is indicated by Hsf in FIG. In the figure, Hc
f indicates the coercive force of the magnetization of the free magnetic layer.

If the first free magnetic layer 31a and the second free magnetic layer 31c are formed to have different magnetic moments per unit area, the free magnetic layer 31
, The spin-flop magnetic field Hsf increases. Thereby, the range of the magnetic field in which the free magnetic layer 31 maintains the ferrimagnetic state is widened, and the stability of the free magnetic layer 31 in the ferrimagnetic state is increased.

In the present embodiment, at least one of the first free magnetic layer 31a and the second free magnetic layer 31c is preferably formed of a magnetic material having the following composition.

The composition formula is represented by CoFeNi, in which the composition ratio of Fe is 9 to 17 atomic%, the composition ratio of Ni is 0.5 to 10 atomic%, and the remaining composition is Co It is.

As a result, the first free magnetic layer 31a and the second
The exchange coupling magnetic field in the RKKY interaction generated between the free magnetic layers 31c can be increased. Specifically, the magnetic field when the antiparallel state collapses, that is, the spin-flop magnetic field (Hsf) can be increased to about 293 (kA / m).

Therefore, the magnetizations at both ends of the first free magnetic layer 31a and the second free magnetic layer 31c located below the vertical bias layer 18 can be appropriately pinned in an antiparallel state, and the occurrence of side reading is suppressed. can do.

It is preferable that both the first free magnetic layer 31a and the second free magnetic layer 31c are formed of the CoFeNi alloy. Thereby, a higher spin-flop magnetic field can be obtained more stably, and the first free magnetic layer 3
1a and the second free magnetic layer 31c can be appropriately magnetized in an antiparallel state.

If the composition is within the above range, the magnetostriction of the first free magnetic layer 31a and the second free magnetic layer 31c is reduced by-
It can be within the range of 3 × 10 ^-6 to 3 × 10 ^{-6 and} the coercive force can be reduced to 790 (A / m) or less.

Furthermore, the soft magnetic characteristics of the free magnetic layer 31 are improved, and the suppression of the decrease in the resistance change (ΔR) and the resistance change rate (ΔR / R) due to the diffusion of Ni between the nonmagnetic material layers 14 is appropriately performed. It is possible to plan.

Also in the present embodiment, it is easy to fix the magnetization direction of free magnetic layer 31 in a direction orthogonal to the magnetization direction of pinned magnetic layer 13, so that the track width Tw of the thin-film magnetic element can be accurately defined. . Further, even if the first antiferromagnetic layer 12 and the longitudinal bias layer 18 are formed using the same composition of antiferromagnetic material, the direction of the exchange anisotropic magnetic field of the first antiferromagnetic layer 12 is set in the Y direction in the drawing. The exchange anisotropic magnetic field of the vertical bias layer 18 can be directed in the X direction in the drawing while keeping the orientation.

The thin-film magnetic element shown in FIG. 10 is different from the thin-film magnetic element shown in FIG. 5 in that the thin-film magnetic element formed by the first embodiment shown in FIG. The same effect as can be obtained.

FIG. 11 is a sectional view of a thin-film magnetic element formed according to the seventh embodiment of the present invention, as viewed from the ABS side.

The method of manufacturing this thin-film magnetic element is almost the same as the method of manufacturing the thin-film magnetic element shown in FIG. 10. In FIG. 1, the free magnetic layer 31 is formed by reducing the magnitude of the magnetic moment per unit area. The first free magnetic layer 31a and the second free magnetic layer 31c which are different from each other
b, when formed as a so-called synthetic ferri-free type free magnetic layer, the intermediate layer 9 is interposed between the first free magnetic layer 31a and the non-magnetic material layer 14.
1 is different from the method of manufacturing the thin film magnetic element shown in FIG. The intermediate layer 91 is made of a CoFe alloy or C
Preferably, it is formed of an o-alloy. In particular, it is preferably formed of a CoFe alloy.

The formation of the intermediate layer 91 prevents diffusion of a metal element or the like at the interface with the nonmagnetic material layer 14 and improves the resistance change amount (ΔR) and the resistance change rate (ΔR / R). Can be planned. The intermediate layer 91 is formed at about 5 °.

In particular, if the first free magnetic layer 31a in contact with the nonmagnetic material layer 14 is formed of a CoFeNi alloy having the above composition ratio, the diffusion of the metal element between the nonmagnetic material layer 14 and the first free magnetic layer 31a can be appropriately suppressed. The need to form an intermediate layer 91 made of a CoFe alloy or Co between the first free magnetic layer 31a and the non-magnetic material layer 14
a is smaller than when a is formed of a magnetic material containing no Co, such as a NiFe alloy.

However, the first free magnetic layer 31a is made of CoFe
Even when the first free magnetic layer 31a is formed of a Ni alloy,
Providing an intermediate layer 91 made of a CoFe alloy or Co between the first free magnetic layer 31 a and the nonmagnetic material layer 14.
It is preferable from the viewpoint that the diffusion of the metal element between the metal layer and the nonmagnetic material layer 14 can be more reliably prevented.

An intermediate layer 91 is provided between the first free magnetic layer 31a and the nonmagnetic material layer 14, and the first free magnetic layer 31a
And at least one of the second free magnetic layer 31c is made of CoF
When formed of an eNi alloy, F of the CoFeNi alloy
It is preferable that the composition ratio of e is 7 atom% or more and 15 atom% or less, the composition ratio of Ni is 5 atom% or more and 15 atom% or less, and the remaining composition ratio is Co.

Thus, the first free magnetic layer 31a and the second
The exchange coupling magnetic field in the RKKY interaction generated between the free magnetic layers 31c can be increased. Specifically, the magnetic field when the antiparallel state collapses, that is, the spin-flop magnetic field (Hsf) can be increased to about 293 (kA / m).

Therefore, the magnetizations at both ends of the first free magnetic layer 31a and the second free magnetic layer 31c located below the vertical bias layer 18 can be appropriately pinned in an antiparallel state, thereby suppressing the occurrence of side reading. can do.

In the present invention, the first free magnetic layer 31a
And both the second free magnetic layer 31c and the CoFeNi
Preferably, it is formed of an alloy. Thereby, a high spin-flop magnetic field can be obtained more stably.

When the composition is within the above range, the magnetostriction of the first free magnetic layer 31a and the second free magnetic layer 31c can be kept within the range of -3 × 10 ^-6 to 3 × 10 ^-6 , Further, the coercive force can be reduced to 790 (A / m) or less. Further, the soft magnetic characteristics of the free magnetic layer 24 can be improved.

FIG. 12 is a sectional view of a thin-film magnetic element formed according to the eighth embodiment of the present invention, as viewed from the ABS side.

The method of manufacturing this thin-film magnetic element is almost the same as that of the sixth embodiment, except that the multilayer film A3 is formed without any other antiferromagnetic layer.

In the present embodiment, since the uppermost layer of the multilayer film A3 is the nonmagnetic layer 16, the surface of the nonmagnetic layer 16 is oxidized during the first magnetic field annealing. Therefore, before laminating the vertical bias layer 18, the surface of the nonmagnetic layer 16 is cut by about 20 ° by ion milling or the like to remove an oxidized portion.

Also in the present embodiment, it is easy to fix the magnetization direction of free magnetic layer 31 in a direction orthogonal to the magnetization direction of fixed magnetic layer 13, so that the track width Tw of the thin-film magnetic element can be accurately defined. . Further, even if the first antiferromagnetic layer 12 and the longitudinal bias layer 18 are formed using the same antiferromagnetic material, the direction of the exchange anisotropic magnetic field of the first antiferromagnetic layer 12 is changed in the Y direction in the drawing. The exchange anisotropic magnetic field of the vertical bias layer 18 can be directed in the X direction in the drawing while keeping the orientation.

The thin-film magnetic element shown in FIG.
As for the other effects of the thin film magnetic element formed by the sixth embodiment shown in FIG. 10, the same effects as those of the thin film magnetic element shown in FIG. 10 can be obtained.

When forming a thin-film magnetic element according to the second to fifth embodiments, the free magnetic layer 15
It may be formed as a synthetic ferri-free type free magnetic layer.

FIG. 13 is a sectional view of a thin-film magnetic element formed according to the ninth embodiment of the present invention as viewed from the ABS side.

The difference from the first embodiment is that, in FIG. 1, after the free magnetic layer 15 is formed, the nonmagnetic layer 16 and the other antiferromagnetic layer 17 are not laminated, and the top layer is the free magnetic layer. 1
5 in that a multilayer film A4 is formed, the multilayer film A4 is annealed in a first magnetic field, and then a vertical bias layer is laminated on the multilayer film A4.

In the present embodiment, since the uppermost layer of the multilayer film A4 is the free magnetic layer 15, the surface of the free magnetic layer 15 is oxidized when the multilayer film A4 is annealed in the first magnetic field. Therefore, before stacking the vertical bias layer 18,
The surface of the free magnetic layer 15 is formed by ion milling or the like by 20 mm.
Remove the oxidized part by shaving moderately. Since the thickness of the free magnetic layer 15 greatly affects the magnetoresistance effect, when the first free magnetic layer 15 is formed, the thickness of the final product is reduced by ion milling or the like more than the thickness of the final product. For example, it is preferable to form a film as thick as about 20 °. Alternatively, before stacking the vertical bias layer 18, the free magnetic layer 15 may be formed again by the thickness removed by ion milling or the like, and then the vertical bias layer 18 may be formed continuously.

The thin-film magnetic element shown in FIG.
5, the magnetization direction of the free magnetic layer 15 is shown by exchange coupling with the other antiferromagnetic layer 17 and the vertical bias layer 18 because the vertical bias layer 18 as the second antiferromagnetic layer is laminated on the upper layer of FIG. Aligned in X direction.

In the present embodiment, the bottom surface 21b of the concave portion 21
T6 of the region E of the vertical bias layer 18 located below
Is larger than 0 and 30 ° or less, the bottom surface 2
1b, the region E of the vertical bias layer 18 located below
No irregular-order transformation occurs due to annealing in the second magnetic field, and no exchange coupling magnetic field is generated.

That is, the magnetization direction of the free magnetic layer 15 is limited to the longitudinal bias layer 18 only at both ends D, D in the track width direction other than the region located below the bottom surface 21b of the concave portion 21.
Fixed by exchange coupling with

The bottom surface 21b of the concave portion 21 of the free magnetic layer 15
In the state where no external magnetic field is applied, a region E located below the lower end is aligned in the X direction in the drawing along both ends D and D whose magnetization directions are fixed by exchange coupling with the vertical bias layer 18. Is applied, the magnetization direction changes.

Therefore, the track width of the thin-film magnetic element is determined by the width Tw of the concave portion. As described above, in the present invention, the concave portion 21 is formed so that the vertical bias layer formed with a uniform thickness is formed in a direction perpendicular to the surface 11a of the substrate 11 by using reactive ion etching (RIE) or ion milling. Since it can be formed only by shaving, it is possible to form the concave portion 21 with an accurate width Tw.
That is, the track width of the thin-film magnetic element can be accurately defined.

Further, in this embodiment, the multilayer film A4 is annealed in a first magnetic field so that the direction of the exchange anisotropic magnetic field of the first antiferromagnetic layer 12 is directed in the Y direction in the drawing, and then the vertical bias layer 18 is The layers are stacked and subjected to annealing in a second magnetic field in the X direction shown in the figure.

The second heat treatment temperature in the annealing in the second magnetic field is set to a temperature lower than the blocking temperature at which the first antiferromagnetic layer 12 loses the exchange coupling magnetic field, and the magnitude of the second magnetic field is set to the second temperature. By making the first antiferromagnetic layer 12 smaller than the exchange anisotropic magnetic field of the first antiferromagnetic layer 12, even if the first antiferromagnetic layer 12 and the longitudinal bias layer 18 are formed using the same composition of antiferromagnetic material, The exchange anisotropic magnetic field of the longitudinal bias layer 18 can be directed in the illustrated X direction while the direction of the exchange anisotropic magnetic field of the magnetic layer 12 is directed in the illustrated Y direction.

The thin-film magnetic element shown in FIG. 13 has the same effects as those of the thin-film magnetic element formed according to the first embodiment shown in FIG. The same effect as that of the thin film magnetic element can be obtained.

When the thin-film magnetic element is formed according to the present embodiment, the free magnetic layer 15 may be formed as a synthetic ferri-free type free magnetic layer.

FIGS. 14 to 18 are sectional views for illustrating a method of manufacturing a thin-film magnetic element according to the tenth embodiment of the present invention.

[0271] First, as shown in FIG.
The same multilayer film A as in FIG. 1 is formed. 14 to FIG.
In FIG. 8, only the other antiferromagnetic layer 17 of the uppermost layer of the multilayer film A is clearly shown for the sake of easy understanding of the drawing. From the side, a first antiferromagnetic layer 12, a fixed magnetic layer 13, a nonmagnetic material layer 14, a free magnetic layer 15, and a nonmagnetic layer 16 are sequentially stacked.

The first antiferromagnetic layer 12, the pinned magnetic layer 13, the nonmagnetic material layer 14, the free magnetic layer 15, the nonmagnetic layer 16, and the other antiferromagnetic layer 17 are formed by a thin film forming process such as a sputtering method or a vapor deposition method. Formed by

Next, a resist layer 51 for lift-off is formed on the multilayer film A. As shown in FIG. 15, the resist layer 51 has cut portions 51a, 51a formed on the lower surface thereof. A region having a track width Tw in the multilayer film A is completely covered with the resist layer 51.

The multilayer film A in the state shown in FIG. 15 is annealed in a first magnetic field at a first heat treatment temperature and in a first magnetic field oriented in the Y direction to form a first antiferromagnetic layer 12. An exchange anisotropic magnetic field is generated, and the magnetization direction of the fixed magnetic layer 13 is fixed in the Y direction in the figure. In this embodiment, the first heat treatment temperature is 270 ° C., and the first magnitude of the magnetic field is 800 k (A / A).
m).

The thickness of the other antiferromagnetic layer 17 is 30
Å. If the thickness of the other antiferromagnetic layer 17 is 30 ° or less, even if the other antiferromagnetic layer 17 is annealed in a magnetic field, transformation from an irregular structure to a regular structure does not occur, and an exchange anisotropic magnetic field is generated. do not do. Therefore, when the multilayer film A is annealed in the first magnetic field, no exchange anisotropic magnetic field is generated in the other antiferromagnetic layers 17, and the magnetization direction of the free magnetic layer 15 is fixed in the Y direction in the drawing. Never.

When the multilayer film A is annealed in the first magnetic field, the region of the other antiferromagnetic layer 17 which is not masked by the resist layer 51 is 10 to 20 ° from the surface thereof.
Oxidizes to a degree. Therefore, as shown in FIG.
In this state, the surface of the other antiferromagnetic layer 17 is ground by about 20 ° by ion milling which is incident on the surface of the other antiferromagnetic layer 17 in a direction perpendicular to the surface of the other antiferromagnetic layer 17 to remove the oxidized portion. As described above, in the present embodiment, since the other antiferromagnetic layer 16 is stacked on the uppermost layer of the multilayer film A, the oxidation of the nonmagnetic layer 16 and the free magnetic layer 15 can be prevented.

Further, the vertical bias layer 4 as a second antiferromagnetic layer is formed on the multilayer film A by the step shown in FIG.
1 and 41 and electrode layers 42 and 42 are formed. In the present embodiment, the sputtering method used for forming the vertical bias layers 41, 41 and the electrode layers 42, 42 is an ion beam sputtering method, a long throw sputtering method, or a collimation sputtering method. It is preferable that at least one of them is used.

As shown in FIG. 17, in this embodiment, the substrate 11 on which the multilayer film A is formed is connected to the vertical bias layers 41 and 4.
The vertical bias layers 41 are formed in a direction perpendicular to the multilayer film A by placing the target 52 in a direction perpendicular to the target 52 formed by the composition 1 and using, for example, an ion beam sputtering method.

In a region covered by both ends of the resist layer 51, sputtered particles are less likely to be deposited. Therefore,
In the vicinity of the region covered by both ends of the resist layer 51, the vertical bias layers 41, 41 and the electrode layers 42, 42 are formed to be thin, and the film thickness of the vertical bias layers 41, 41 and the electrode layers 42, 42 is small. The dimension in the direction is reduced at both side portions Sb of the track.

Note that, as shown in FIG.
A layer 41a having the same composition as the vertical bias layers 41, 41 and layers 42a, 42a having the same composition as the electrode layers 42, 42 are also formed thereon.

The vertical bias layers 41, 41 are made of a PtMn alloy or X—Mn (where X is Pd, Ir, R), like the first antiferromagnetic layer 12 and the other antiferromagnetic layers 17.
h, Ru, Os, Ni, or Fe), or Pt—Mn—X ′
(Where X 'is Pd, Ir, Rh, Ru, Au, A
g, Os, Cr, Ni, Ar, Ne, Xe, or Kr).

The film thickness at both ends of the vertical bias layers 41 is in the range of 80 to 300 °, for example, 200 °.

The electrode layers 42 are made of, for example, Au, W,
The film is formed using Cr, Ta, or the like.

A multilayer film B formed up to the electrode layers 42, 42
Is annealed in a second magnetic field in a second magnetic field at a second heat treatment temperature and a second magnitude in the X direction to generate an exchange anisotropic magnetic field in the longitudinal bias layers 41, The magnetization direction of the layer 15 is fixed in the illustrated X direction. In the present embodiment, the second heat treatment temperature is 250 ° C., and the second magnitude of the magnetic field is 24 k (A / m).

In this embodiment, the free magnetic layer 15
A non-magnetic layer 16 is stacked in contact with the upper surface of the substrate. At this time, the magnetization direction of the free magnetic layer 15 is aligned with the X direction in the figure by RKKY coupling with the vertical bias layer 41 via the nonmagnetic layer 16.

When the resist layer 51 is removed after the second heat treatment, a thin-film magnetic element as shown in FIG. 18 can be obtained.

The exchange anisotropic magnetic field of the vertical bias layer 41 is generated only in the second magnetic field annealing step. Accordingly, in order to direct the exchange anisotropic magnetic field of the longitudinal bias layer 41 in the X direction while maintaining the direction of the exchange anisotropic magnetic field of the first antiferromagnetic layer 12 in the Y direction, the second The heat treatment temperature is set lower than the blocking temperature at which the first antiferromagnetic layer 12 loses the exchange coupling magnetic field, and the magnitude of the second magnetic field is smaller than the exchange anisotropic magnetic field of the first antiferromagnetic layer 12. Just do it. If the second annealing in a magnetic field is performed under these conditions, the first antiferromagnetic layer 12 and the longitudinal bias layer 41 can be formed using the same antiferromagnetic material having the same composition. The exchange anisotropic magnetic field of the longitudinal bias layer 41 can be directed in the illustrated X direction while the direction of the exchange anisotropic magnetic field of the layer 12 is directed in the illustrated Y direction.

That is, in the present invention, the free magnetic layer 15
Is easily fixed to a direction orthogonal to the magnetization direction of the fixed magnetic layer 13.

As in the present embodiment, other antiferromagnetic layers 1
When the thickness t7 of the layer 7 is set to be larger than 0 and equal to or smaller than 30 °, irregular-order transformation is not generated by annealing in the second magnetic field in a region where the longitudinal bias layer 41 is not formed, and no exchange coupling magnetic field is generated.

That is, the magnetization direction of the free magnetic layer 15 is such that the RKK between the free magnetic layer 15 and the vertical bias layers 41 is only at the both ends in the track width direction of the portion overlapping the vertical bias layers 41.
Fixed by Y-bond.

The vertical bias layers 41 and 4 of the free magnetic layer 15
In the state where no external magnetic field is applied, portions E which do not overlap with 1 are aligned in the X direction in the drawing along both ends where the magnetization direction is fixed by RKKY coupling with the vertical bias layer 41, and an external magnetic field is applied. And its magnetization direction changes. Therefore, the interval between the vertical bias layers 41, 41 in the track width direction becomes the track width Tw of the thin-film magnetic element.

In the present embodiment, the vertical bias layer 4
After the electrode layers 42, 42 are formed on the upper layers 1, 41,
Was performed in the magnetic field, but after the vertical bias layer 41 was laminated, the second magnetic field annealing was performed.
The electrode layers 42 and 42 may be stacked on the layers 1 and 41.

In the present embodiment, the first antiferromagnetic layer 12 is directly laminated on the substrate 11, but the antiferromagnetic layer is formed on the substrate 11 via an alumina layer and an underlayer made of Ta or the like. 12 may be stacked.

A description will be given of the thin-film magnetic element shown in FIG.
The non-magnetic layer 1 is formed on the multilayer film A as the longitudinal bias layers 41, 41.
When the free magnetic layer 15 is laminated via the intermediate layer 6, the magnetization directions of the free magnetic layer 15 are aligned by the RKKY interaction with the longitudinal bias layers 41, 41. The RKKY interaction acts only between the regions D and D of the magnetic layer located immediately below the antiferromagnetic layers (longitudinal bias layers 41 and 41) having a thickness having antiferromagnetism and has antiferromagnetism. It does not act on the region E that is off from immediately below the thick antiferromagnetic layer.

Accordingly, the track width (optical track width) T set as the interval between the vertical bias layers 41, 41 is set.
The region w substantially contributes to the reproduction of the recording magnetic field and becomes a sensitivity region where the magnetoresistance effect is exhibited. That is, the thin-film magnetic element of the present embodiment employs a hard bias method in which the optical track width of the thin-film magnetic element is equal to the magnetic track width, and therefore, it is difficult to control the magnetic track width due to the presence of an insensitive region. In comparison, it is easier to cope with a higher recording density of the recording medium.

Further, since there is no dead area in the area of the track width (optical track width) Tw set at the time of forming the thin-film magnetic element, the optical track width of the thin-film magnetic element can be increased in order to cope with high recording density. A decrease in the reproduction output when Tw is reduced can be suppressed.

However, in the present embodiment, the dimension in the film thickness direction of the vertical bias layers 41, 41 is reduced in both side portions Sb of the track. For this reason, the effect of the exchange coupling between the free magnetic layer 15 and the vertical bias layer 41 in both side portions Sb of the track is reduced. As a result, the magnetization direction of the track side portions Sb of the free magnetic layer 15 in FIG. 18 is not completely fixed in the X direction, and changes when an external magnetic field is applied.

In particular, when the track is narrowed in order to improve the recording density of the magnetic recording medium, not only the information of the magnetic recording track to be read in the area of the track width Tw but also the information of the adjacent magnetic recording track is used. information,
There is a possibility that side reading, in which reading is performed in the area of both side portions Sb of the track, occurs.

Further, in the present invention, since the side end surfaces S, S of the multilayer film of the thin-film magnetic element can be formed so as to be perpendicular to the substrate surface, the length of the free magnetic layer 15 in the width direction can be reduced. Variation can be suppressed.

In the case where the magnetization direction of the free magnetic layer 15 is aligned by the RKKY interaction with the vertical bias layers 41, 41 as in this embodiment, the vertical bias layer 4
The exchange coupling force can be made stronger than that in which the free magnetic layer 15 is in direct contact with the first and fourth magnetic layers 1 and 41.

When the non-magnetic layer 16 is made of a conductive material as in the present embodiment, the non-magnetic layer 16 is formed as a backed layer having a spin filter effect (backed layer).
layer).

When the backed layer (nonmagnetic layer 16) having the spin filter effect is provided in contact with the free magnetic layer 15, the center height position where the sense current flows inside the stacked body is set more than when the backed layer is not provided. It can be moved to the backed layer side. That is, the center height position of the sense current is separated from the free magnetic layer 15, the intensity of the sense current magnetic field at the position of the free magnetic layer 15 is reduced, and the influence of the sense current magnetic field on the fluctuating magnetic field of the free magnetic layer 15 is reduced. . Therefore, the asymmetry can be reduced.

In this embodiment, another antiferromagnetic layer 1
By forming the layer 7 as a single-layer film or a multilayer film of a semi-metallic Whistler alloy such as NiMnSb or PtMnSb, the other antiferromagnetic layer 17 can function as a specular reflection layer.

The other antiferromagnetic layer 17, which is a specular reflection layer, forms a potential barrier at the interface with the nonmagnetic layer 16, and transfers upspin conduction electrons moving in the free magnetic layer 15 and the nonmagnetic layer 16, The spin can be reflected while keeping its state, and the mean free path of the conduction electrons of the up spin can be further extended. That is, a so-called specular reflection effect can be exhibited, and the difference between the mean free path of up-spin conduction electrons and the mean free path of down-spin conduction electrons can be further increased.

That is, the mean free path of the whole conduction electrons can be largely changed by the action of the external magnetic field.
Magnetoresistance change rate (ΔR /
R) can be increased.

The increase in the mean free path difference between the up-spin conduction electrons and the down-spin conduction electrons due to the spin filter effect and the specular reflection effect is more effective when the free magnetic layer 15 is relatively thin.

If the thickness of the free magnetic layer 15 is smaller than 15 °, it is difficult to form the free magnetic layer 15 so as to function as a ferromagnetic material layer, and a sufficient magnetoresistance effect cannot be obtained.

If the thickness of the free magnetic layer 15 is more than 45 °, up-spin conduction electrons scattered before reaching the other antiferromagnetic layer 17 (specular reflection layer) increase, resulting in a specular reflection effect. (Specular effect) is not preferred because the rate of change in the resistance change rate decreases.

In FIG. 18, one pinned magnetic layer 13a and second pinned magnetic layer 13c having different magnetic moments per unit area are stacked via a non-magnetic intermediate layer 13b to form one pinned magnetic layer. It functions as the layer 13.

The first fixed magnetic layer 13a is formed in contact with the antiferromagnetic layer 12, and is subjected to exchange coupling at the interface between the first fixed magnetic layer 13a and the antiferromagnetic layer 12 by annealing in a magnetic field. Generates an exchange anisotropic magnetic field, and the magnetization direction of the first pinned magnetic layer 13a is fixed in the Y direction in the figure. When the magnetization direction of the first pinned magnetic layer 13a is fixed in the Y direction in the figure, the magnetization direction of the second fixed magnetic layer 13c opposed via the non-magnetic intermediate layer 13b becomes the same as the magnetization direction of the first fixed magnetic layer 13a. It is fixed in an anti-parallel state.

The direction of the combined magnetic moment per unit area obtained by adding the magnetic moment per unit area of the first fixed magnetic layer 13a and the magnetic moment per unit area of the second fixed magnetic layer 13c is Magnetization direction.

Thus, the first pinned magnetic layer 13a and the second
The magnetization direction of the pinned magnetic layer 13c is in an antiparallel ferrimagnetic state, and the first pinned magnetic layer 13a and the second pinned magnetic layer 13c fix the other magnetization direction to each other. This is preferable because the magnetization direction of the magnetic layer 13 can be stabilized in a certain direction.

In FIG. 18, the first pinned magnetic layer 13a and the second pinned magnetic layer 13c are formed using the same material, and the thicknesses thereof are made different, so that the magnetic moment per unit area is reduced. I make them different.

The first fixed magnetic layer 13a and the second fixed magnetic layer 13c are formed of a ferromagnetic material, for example, a NiFe alloy, Co, CoNiFe alloy, CoFe alloy, CoNi alloy, or the like. In particular, it is preferably formed of a NiFe alloy or Co. Preferably, the first pinned magnetic layer 13a and the second pinned magnetic layer 13c are formed of the same material.

The non-magnetic intermediate layer 13b is formed of a non-magnetic material, and is composed of Ru, Rh, Ir, Cr, R
e, Cu, or one or more of these alloys. In particular, it is preferably formed of Ru.

When the fixed magnetic layer 13 is formed by laminating a first fixed magnetic layer 13a and a second fixed magnetic layer 13c above and below a nonmagnetic intermediate layer 13b, the first fixed magnetic layer 1
3a and the second pinned magnetic layer 13c fix the magnetization directions of each other, so that the magnetization direction of the pinned magnetic layer 13 can be strongly fixed as a whole in a fixed direction. That is, the exchange coupling magnetic field Hex between the second antiferromagnetic layer 12 and the pinned magnetic layer 13
Can be obtained as a large value, for example, 80 to 160 kA / m. Therefore, after annealing in the first magnetic field for directing the magnetization direction of the second antiferromagnetic layer 12 to the height direction, the second magnetic field for directing the magnetization direction of the vertical bias layer 18 to the track width direction is used. Medium annealing can increase the longitudinal bias magnetic field generated by the longitudinal bias layer 18 while preventing the magnetization direction of the fixed magnetic layer 13 from being fixed in the track width direction.

In this embodiment, the fixed magnetic layer 13
The demagnetizing field (dipole magnetic field) due to the fixed magnetization described above can be canceled by the mutual cancellation of the static magnetic field coupling between the first fixed magnetic layer 13a and the second fixed magnetic layer 13c. Thereby, the contribution of the demagnetizing field (dipole magnetic field) due to the fixed magnetization of the fixed magnetic layer 13 to the variable magnetization of the free magnetic layer 15 can be reduced.

Therefore, it is easier to correct the direction of the fluctuating magnetization of the free magnetic layer 15 to a desired direction, and it is possible to obtain a spin valve type thin film magnetic element having small asymmetry and excellent symmetry.

The demagnetizing field (dipole magnetic field) Hd due to the fixed magnetization of the fixed magnetic layer 13 has a non-uniform distribution such that it is large at the end and small at the center in the element height direction. Although the formation of a single magnetic domain in the magnetic field may be hindered, the dipole magnetic field Hd can be substantially set to Hd = 0 by forming the fixed magnetic layer 13 in the above-described laminated structure. As a result, non-uniform magnetization and Barkhausen noise can be prevented.

FIG. 19 is a sectional view of a thin-film magnetic element formed according to the eleventh embodiment of the present invention as viewed from the ABS side.

The method of manufacturing this thin-film magnetic element is almost the same as that of the tenth embodiment shown in FIGS.

The difference from the first embodiment is that after the free magnetic layer 15 is formed, another antiferromagnetic layer 17 is directly stacked on the free magnetic layer 15 without forming the nonmagnetic layer 16. The only difference is that a multilayer film A1 is formed, the multilayer film A1 is annealed in a first magnetic field, and then a vertical bias layer is laminated on the multilayer film A1.

The thin-film magnetic element shown in FIG.
5, the other antiferromagnetic layer 17 and the vertical bias layers 41, 41, which are the second antiferromagnetic layers, are stacked, so that the magnetization direction of the free magnetic layer 15 is The alignment is performed in the X direction in the figure by exchange coupling with the vertical bias layers 41 and 41.

In this embodiment, when the thickness t8 of the other antiferromagnetic layer 17 is set to be larger than 0 and equal to or smaller than 30 °, in the region E where the vertical bias layers 41 and 41 do not overlap each other, the region B is inactivated by the second magnetic field annealing. No rule-order transformation occurs and no exchange coupling magnetic field is generated.

That is, the magnetization direction of the free magnetic layer 15 is fixed by antiferromagnetic coupling with the vertical bias layers 41, 41 only at both ends D, D in the track width direction where the vertical bias layers 41, 41 overlap.

The vertical bias layers 41 and 4 of the free magnetic layer 15
In a state where no external magnetic field is applied, the region E where the 1 does not overlap is aligned in the X direction in the drawing along both ends D and D whose magnetization directions are fixed by exchange coupling with the longitudinal bias layers 41 and 41. When a magnetic field is applied, its magnetization direction changes. Therefore, the interval between the vertical bias layers 41, 41 in the track width direction becomes the track width Tw of the thin-film magnetic element.

After the free magnetic layer 15 is formed, the nonmagnetic layer 16
Also in the manufacturing method in which another antiferromagnetic layer 17 is stacked without stacking, the magnetization direction of the free magnetic layer 15 is set to a direction orthogonal to the magnetization direction of the fixed magnetic layer 13 as in the tenth embodiment. It becomes easy to fix.

However, in the present embodiment, the dimension in the film thickness direction of the vertical bias layers 41, 41 is reduced in both side portions Sb of the track. For this reason, the effect of the exchange coupling between the free magnetic layer 15 and the vertical bias layer 41 in both side portions Sb of the track is reduced. As a result, the magnetization direction of the track side portions Sb of the free magnetic layer 15 in FIG. 19 is not completely fixed in the X direction and changes when an external magnetic field is applied.

In particular, when the track is narrowed in order to improve the recording density of the magnetic recording medium, not only the information of the magnetic recording track to be read within the area of the track width Tw but also the information of the adjacent magnetic recording track is used. information,
There is a possibility that side reading, in which reading is performed in the area of both side portions Sb of the track, occurs.

Even if the first antiferromagnetic layer 12 and the longitudinal bias layers 41, 41 are formed using the same composition of antiferromagnetic material, the direction of the exchange anisotropic magnetic field of the first antiferromagnetic layer 12 Can be directed in the X direction in the drawing while the exchange anisotropic magnetic field of the longitudinal bias layers 41, 41 is directed in the Y direction in the drawing.

The thin-film magnetic element shown in FIG.
In addition to the spin filter effect provided by the thin film magnetic element formed according to the tenth embodiment shown in FIG. 18, the same effect as the thin film magnetic element shown in FIG. 18 can be obtained.

FIG. 20 is a sectional view of a thin film magnetic element formed according to the twelfth embodiment of the present invention, as viewed from the ABS side.

The method of manufacturing this thin-film magnetic element is almost the same as that of the tenth embodiment shown in FIGS. 14 to 18. In FIG. 14, the free magnetic layer 31 is provided with a magnetic moment per unit area. The first free magnetic layer 31a and the second free magnetic layer 31c having different sizes are formed as so-called synthetic ferri-free type free magnetic layers laminated via a non-magnetic intermediate layer 31b, and the multilayer film A3 The only difference is that other antiferromagnetic layers are formed without being laminated.

In the present embodiment, since the uppermost layer of the multilayer film A3 is the nonmagnetic layer 16, the surface of the nonmagnetic layer 16 is oxidized in the first magnetic field annealing. Therefore, before laminating the vertical bias layer 41, the surface of the nonmagnetic layer 16 is cut by about 20 ° by ion milling or the like to remove the oxidized portion.

The first free magnetic layer 31a and the second free magnetic layer 31c are formed of a ferromagnetic material, for example, a NiFe alloy, Co, CoNiFe alloy, CoFe
Alloy, a CoNi alloy or the like,
In particular, it is preferably formed of a NiFe alloy.

The non-magnetic intermediate layer 31b is formed of a non-magnetic material, and is composed of Ru, Rh, Ir, Cr, R
It is formed of one or more alloys of e and Cu. In particular, it is preferably formed of Ru.

Note that a diffusion prevention layer made of Co or the like may be formed between the first free magnetic layer 31a and the nonmagnetic material layer. This diffusion preventing layer is the first free magnetic layer 3
1a and the non-magnetic material layer 14 are prevented from interdiffusion.

The first free magnetic layer 31a and the second free magnetic layer 31c are formed so that the respective magnetic moments per unit area are different. The magnetic moment per unit area is represented by the product of the saturation magnetization (Ms) and the film thickness (t). Therefore, for example, the first
The free magnetic layer 31a and the second free magnetic layer 31c are formed using the same material, and the thicknesses of the free magnetic layer 31a and the second free magnetic layer 31c are made different from each other to form a unit of the first free magnetic layer 31a and the second free magnetic layer 31c. The magnetic moment per area can be different.

When a diffusion preventing layer made of Co or the like is formed between the first free magnetic layer 31a and the nonmagnetic material layer 14, the magnetic moment per unit area of the first free magnetic layer 31a is reduced. It is preferable that the sum of the magnetic moment per unit area of the diffusion preventing layer and the magnetic moment per unit area of the second free magnetic layer 31c be different.

The thickness tf of the second free magnetic layer 31c
2 is preferably in the range of 0.5 to 2.5 nm.
Further, the thickness tf1 of the first free magnetic layer 31a is 2.5 to
It is preferably in the range of 4.5 nm. Note that the thickness tf1 of the first free magnetic layer 31a is more preferably in the range of 3.0 to 4.0 nm, and still more preferably 3.0.
The range is 5 to 4.0 nm. If the thickness tf1 of the first free magnetic layer 31a is out of the above range, the rate of change in magnetoresistance of the spin-valve thin-film magnetic element cannot be increased, which is not preferable.

In FIG. 20, one free magnetic layer 31 has a structure in which a first free magnetic layer 31a and a second free magnetic layer 31c having different magnetic moments per unit area are laminated via a nonmagnetic intermediate layer 31b. Function as

The magnetization directions of the first free magnetic layer 31a and the second free magnetic layer 31c are in antiparallel ferrimagnetic states different by 180 degrees. At this time, the direction in which the magnetic moment per unit area is larger, for example, the magnetization direction of the first free magnetic layer 31a is directed to the direction of the magnetic field generated from the longitudinal bias layers 41, 41, and the magnetization of the second free magnetic layer 31c The direction is turned to the opposite direction by 180 degrees.

When the magnetization directions of the first free magnetic layer 31a and the second free magnetic layer 31c are in the antiparallel ferrimagnetic state in which the magnetization directions are different by 180 degrees, the same effect as reducing the thickness of the free magnetic layer 31 can be obtained. As a result, the saturation magnetization decreases, the magnetization of the free magnetic layer 31 tends to fluctuate, and the magnetic field detection sensitivity of the magnetoresistance effect element improves.

The direction of the magnetic moment per unit area obtained by adding the magnetic moment per unit area of the first free magnetic layer 31a and the magnetic moment per unit area of the second free magnetic layer 31c is equal to that of the free magnetic layer 31. It becomes the magnetization direction.

However, only the magnetization direction of the first free magnetic layer 31a contributes to the output in relation to the magnetization direction of the fixed magnetic layer 13.

When the relationship between the magnetic film thicknesses of the first free magnetic layer and the second free magnetic layer is different, the spin flop magnetic field of the free magnetic layer 31 can be increased.

Also in the present embodiment, the track width Tw of the thin-film magnetic element can be defined accurately. Also, the first antiferromagnetic layer 1
2 and the vertical bias layers 41, 41 are formed by using the same composition of antiferromagnetic material, while the direction of the exchange anisotropic magnetic field of the first antiferromagnetic layer 12 is directed in the illustrated Y direction. Layer 4
1,41 exchange anisotropic magnetic fields can be directed in the illustrated X direction.

The thin-film magnetic element shown in FIG.
The other effects of the thin-film magnetic element formed according to the tenth embodiment shown in FIG. 18 can be the same as those of the thin-film magnetic element shown in FIG.

When forming the thin-film magnetic element according to the tenth and eleventh embodiments, the free magnetic layer 15
May be formed as a synthetic ferri-free type free magnetic layer.

For example, resist layers 53 are formed on the electrode layers 42 of the thin-film magnetic element shown in FIG. 18 as shown in FIG. 21 and are sandwiched between the resist layers 53 as shown in FIG. After removing the resisted regions by ion milling or RIE or the like to the other antiferromagnetic layer 17, the resist layers 53 are removed, and as shown in FIG. 41b, 41b
Is a plane perpendicular to the surface 11a of the substrate 11. Therefore, in the region where the free magnetic layer 15 and the vertical bias layers 41 overlap, the effect of exchange coupling between the free magnetic layer 15 and the vertical bias layers 41 is uniform. That is,
The track width Tw of the thin-film magnetic element can be accurately defined.

FIGS. 24 to 28 are sectional views showing a fourteenth embodiment of the present invention. FIG. 24 shows the first embodiment of the present invention.
In the embodiment, the first antiferromagnetic layer 12 and the first pinned magnetic layer 13 are formed on the multilayer film shown in FIG.
a, a synthetic ferri-pinned fixed magnetic layer 13 comprising a non-magnetic intermediate layer 13b and a second fixed magnetic layer 13c, a non-magnetic material layer 14, a free magnetic layer 15, a non-magnetic layer 16, and another antiferromagnetic layer 17; The vertical bias layer 18, which is the second antiferromagnetic layer, is stacked on the stacked multilayer film A.

After the formation of the multilayer film A, the vertical bias layer 1
Before laminating the multilayer 8, the multilayer film A is annealed in a first magnetic field at a first heat treatment temperature and in a magnetic field of a first magnitude oriented in the Y direction and exchanged with the first antiferromagnetic layer 12. An isotropic magnetic field is generated to fix the magnetization direction of the pinned magnetic layer 13 in the illustrated Y direction. In this embodiment, the first heat treatment temperature is set to 27.
At 0 ° C., the first magnitude of the magnetic field is 800 k (A / m).

In this case, the thickness of the other antiferromagnetic layer 17 is 30
Å. If the thickness of the other antiferromagnetic layer 17 is 30 ° or less, even if the other antiferromagnetic layer 17 is annealed in a magnetic field, transformation from an irregular structure to a regular structure does not occur, and an exchange anisotropic magnetic field is generated. do not do. Therefore, when the multilayer film A is annealed in the first magnetic field, no exchange anisotropic magnetic field is generated in the other antiferromagnetic layers 17, and the magnetization direction of the free magnetic layer 15 is fixed in the Y direction in the drawing. Never.

When the multilayer film A is annealed in the first magnetic field, the other antiferromagnetic layer 17 is 10 to 2
Oxidates about 0 °. Therefore, the surface of the other antiferromagnetic layer 17 in the state of the multilayer film A is cut by about 20 ° by ion milling to remove the oxidized portion. After shaving the surface of the antiferromagnetic layer 17, a vertical bias layer 18 is formed.

Next, as shown in FIG. 25, a lift-off resist 61 covering an area slightly larger than the track width is laminated on the surface of the vertical bias layer 18. Resist layer 61
Are formed with cutouts 61a, 61a on the lower surface thereof.

Further, electrode layers 71, 71 are formed on the vertical bias layer 18 by the process shown in FIG. In the present embodiment, the sputtering method used for forming the electrode layers 71 is preferably at least one of an ion beam sputtering method, a long throw sputtering method, and a collimation sputtering method.

In the present embodiment, the substrate 11 on which the multilayer film A is formed is placed in a direction perpendicular to the target formed with the composition of the electrode layers 71, 71, thereby using, for example, an ion beam sputtering method. Then, the electrode layers 71, 71 are formed in a direction perpendicular to the multilayer film A.

In a region covered by both ends of the resist layer 61, sputtered particles are less likely to be deposited. Therefore,
In the vicinity of the region covered by both ends of the resist layer 61, the electrode layers 71, 71 are formed to be thin, and the electrode layers 71, 71 are formed with inclined surfaces 71a, 71a. The electrode layers 71 are formed using, for example, Au, W, Cr, Ta, or the like. Note that, on the resist layer 61, a layer 71b having the same composition as the electrode layers 71, 71 is formed. After forming the electrode layers 71, 71, the resist layer 61 is removed to obtain a state shown in FIG.

Further, as shown in FIG.
The electrode layer 7 of the vertical bias layer 18 is
The recesses 81 are formed by shaving off portions not covered by the components 1 and 71 by ion milling or reactive ion etching (RIE). Recess 81
Side surfaces 81a, 81a are inclined surfaces 7 of the electrode layers 71, 71.
It is an inclined surface including 1a and 71a. In FIG. 28,
The concave portion 81 is formed such that the bottom surface 81b of the concave portion 81 is located in the vertical bias layer 18.

At this time, the region of the vertical bias layer 18 located below the bottom surface 81b of the concave portion 81 and the other antiferromagnetic layer 17
Is made greater than 0 and less than or equal to 30 °.

After the formation of the concave portion 81, the multilayer film B4 formed up to the electrode layers 71, 71 is annealed in a second magnetic field at a second heat treatment temperature and a second magnetic field oriented in the X direction. Then, an exchange anisotropic magnetic field is generated in the longitudinal bias layer 18,
The magnetization direction of the free magnetic layer 15 is fixed in the illustrated X direction.
In this embodiment, the second heat treatment temperature is set to 250 ° C.
The second magnitude of the magnetic field is 24 k (A / m).

In the present embodiment, the bottom surface 81b of the concave portion 81
Defines the track width Tw. The width of the bottom surface 81b of the concave portion 81 can be defined by adjusting the size of the resist 61 in the step shown in FIG. 25 and adjusting the depth of the concave portion 81 in the step of FIG.

In the step shown in FIG. 28, the concave portion 81 may be formed such that the bottom surface 81b of the concave portion 81 is located in another antiferromagnetic layer 17. Alternatively, the concave portion 81 may be formed such that the bottom surface 81b of the concave portion 81 is located in the nonmagnetic layer 16.

In the step of FIG. 24, the vertical bias layer 18 may be laminated on the multilayer film A1 shown in FIGS. 8 and 9 instead of the multilayer film A. Alternatively, instead of the multilayer film A, the vertical bias layer 18 is laminated on one of the multilayer film A2 shown in FIG. 10, the multilayer film A3 shown in FIG. 12, and the multilayer film A4 shown in FIG. Is also good. In these cases, the bottom surface 81b of the concave portion 81 is
Inside, in another antiferromagnetic layer 17, or in the nonmagnetic layer 16.

In the first to fourteenth embodiments, the fixed magnetic layer 13 may be formed as a single ferromagnetic material layer.

In the method of manufacturing the thin-film magnetic element shown in FIG. 12 or FIG. 20, at least one of the first free magnetic layer 31a and the second free magnetic layer 31c has a composition formula of CoFeNi, Preferably, the composition ratio is 9 atomic% or more and 17 atomic% or less, the Ni composition ratio is 0.5 atomic% or more and 10 atomic% or less, and the remaining composition is a magnetic material having a composition of Co. .

Thus, the exchange coupling magnetic field in the RKKY interaction generated between the first free magnetic layer 31a and the second free magnetic layer 31c can be increased. Specifically, the magnetic field when the antiparallel state collapses, that is, the spin-flop magnetic field (Hsf) can be increased to about 293 (kA / m).

When the composition is within the above range, the magnetostriction of the first free magnetic layer 31a and the second free magnetic layer 31c can be kept within the range of -3 × 10 ^-6 to 3 × 10 ^-6. Further, the coercive force can be reduced to 790 (A / m) or less.

Further, it is possible to appropriately improve the soft magnetic properties of the free magnetic layer 31 and suppress the reduction of the resistance change amount (ΔR) and the resistance change rate (ΔR / R) due to the diffusion of Ni between the nonmagnetic material layers 14. It is possible to plan.

An intermediate layer 91 made of a CoFe alloy or a Co alloy may be provided between the first free magnetic layer 31a and the nonmagnetic material layer.

When the intermediate layer 91 is provided, the above C
The composition ratio of Fe in the oFeNi alloy is 7 atomic% or more and 15 atomic% or less, and the Ni composition ratio is 5 atomic% or more and 15 atomic%.
Hereinafter, it is preferable that the remaining composition ratio be Co.

In the method of manufacturing the thin-film magnetic element shown in FIGS. 5 to 9, FIGS. 13, 18, and 19,
The free magnetic layer 15 is formed as a synthetic ferri-free type free magnetic layer, and at least one of the first free magnetic layer and the second free magnetic layer has a composition formula of CoFeNi.
The composition ratio of Fe is 9 atomic% or more and 17 atomic% or less, the composition ratio of Ni is 0.5 atomic% or more and 10 atomic% or less, and the remaining composition is formed of a magnetic material of Co. You may.

In addition, the first free magnetic layer and the non-magnetic material layer 1
4, an intermediate layer formed of a CoFe alloy or a Co alloy is provided.
It is preferable that the composition ratio is 7 atomic% or more and 15 atomic% or less, the Ni composition ratio is 5 atomic% or more and 15 atomic% or less, and the remaining composition ratio is Co.

When forming a magnetic head using the thin-film magnetic elements shown in FIGS. 5 to 13 and FIGS. 18 to 20, and the thin-film magnetic element shown in FIG.
An underlying layer made of an insulating material such as alumina, a lower shield layer made of a magnetic alloy laminated on the underlying layer, and an insulating layer laminated on the lower shield between the first and second antiferromagnetic layers 12; A lower gap layer made of a conductive material is formed. A thin film magnetic element is stacked on the lower gap layer. On this thin-film magnetic element, an upper gap layer made of an insulating material and an upper shield layer made of a magnetic alloy laminated on the upper gap layer are formed. Further, an inductive element for writing may be laminated on the upper shield layer.

[0375]

According to the present invention, the multilayer film is annealed in a first magnetic field without laminating a second antiferromagnetic layer on the multilayer film including the first antiferromagnetic layer and the pinned magnetic layer. To fix the magnetization direction of the fixed magnetic layer to a predetermined direction. Thereafter, since the second antiferromagnetic layer is laminated on the multilayer film, no exchange anisotropic magnetic field is generated in the second antiferromagnetic layer immediately after the formation.

The exchange anisotropic magnetic field of the second antiferromagnetic layer is:
Since this occurs for the first time in the annealing in the second magnetic field, it becomes easy to move the magnetization direction of the free magnetic layer in a predetermined direction. Therefore, the second heat treatment temperature is set to a temperature lower than the blocking temperature at which the first antiferromagnetic layer loses the exchange coupling magnetic field, and the magnitude of the second magnetic field is changed to the exchange anisotropy of the first antiferromagnetic layer. By making the magnetization direction smaller than the neutral magnetic field, it becomes easy to fix the magnetization direction of the free magnetic layer in a direction orthogonal to the magnetization direction of the fixed magnetic layer.

In particular, even when the first antiferromagnetic layer and the second antiferromagnetic layer are formed of the same antiferromagnetic material, the magnetization direction of the free magnetic layer is the same as the magnetization direction of the fixed magnetic layer. It can be easily fixed in the orthogonal direction.

[Brief description of the drawings]

FIG. 1 is a sectional view showing one step of a method for manufacturing a thin-film magnetic element according to a first embodiment of the present invention;

FIG. 2 shows a method for manufacturing a thin-film magnetic element according to the present invention.
Sectional view showing a step subsequent to FIG. 1;

FIG. 3 shows a method of manufacturing a thin film magnetic element according to the present invention.
Sectional view showing a step subsequent to FIG. 2;

FIG. 4 shows a method of manufacturing a thin-film magnetic element according to the present invention.
Sectional view showing a step subsequent to FIG. 3;

FIG. 5 is a sectional view of the thin-film magnetic element formed according to the first embodiment of the present invention, as viewed from the ABS side;

FIG. 6 is a cross-sectional view of a thin-film magnetic element formed according to a second embodiment of the present invention, viewed from the ABS side;

FIG. 7 is a sectional view of a thin-film magnetic element formed according to a third embodiment of the present invention, as viewed from the ABS side;

FIG. 8 is a sectional view of a thin-film magnetic element formed according to a fourth embodiment of the present invention, as viewed from the ABS side;

FIG. 9 is a sectional view of a thin-film magnetic element formed according to a fifth embodiment of the present invention, viewed from the ABS side;

FIG. 10 is a sectional view of a thin-film magnetic element formed according to a sixth embodiment of the present invention, viewed from the ABS side;

FIG. 11 is a sectional view of a thin-film magnetic element formed according to a seventh embodiment of the present invention, viewed from the ABS side;

FIG. 12 is a sectional view of a thin-film magnetic element formed according to an eighth embodiment of the present invention, viewed from the ABS side.

FIG. 13 is a sectional view of a thin-film magnetic element formed according to a ninth embodiment of the present invention, as viewed from the ABS side;

FIG. 14 is a sectional view showing one step of a method of manufacturing a thin-film magnetic element according to a tenth embodiment of the present invention;

FIG. 15 is a sectional view showing a step subsequent to FIG. 14 in the method for manufacturing a thin-film magnetic element of the present invention;

FIG. 16 is a sectional view showing a step subsequent to FIG. 15 in the method for manufacturing a thin-film magnetic element of the present invention;

FIG. 17 is a sectional view showing a step subsequent to FIG. 16 in the method for manufacturing a thin-film magnetic element of the present invention;

FIG. 18 is a sectional view of the thin-film magnetic element formed according to the tenth embodiment of the present invention, as viewed from the ABS side;

FIG. 19 is a sectional view of a thin-film magnetic element formed according to an eleventh embodiment of the present invention, viewed from the ABS side.

FIG. 20 is a sectional view of a thin-film magnetic element formed according to a twelfth embodiment of the present invention, viewed from the ABS side;

FIG. 21 is a sectional view showing one step of a method of manufacturing a thin-film magnetic element according to a thirteenth embodiment of the present invention;

FIG. 22 is a sectional view showing a step subsequent to FIG. 21 in the method for manufacturing a thin-film magnetic element of the present invention;

FIG. 23 is a sectional view showing a step subsequent to FIG. 22 in the method for manufacturing a thin-film magnetic element of the present invention;

FIG. 24 is a sectional view showing one step of a method of manufacturing a thin-film magnetic element according to a fourteenth embodiment of the present invention;

FIG. 25 is a sectional view showing a step subsequent to FIG. 24 in the method for manufacturing a thin-film magnetic element of the present invention;

FIG. 26 is a sectional view showing a step subsequent to FIG. 25 in the method for manufacturing a thin-film magnetic element of the present invention;

FIG. 27 is a sectional view showing a step subsequent to FIG. 26 in the method for manufacturing a thin-film magnetic element of the present invention;

FIG. 28 is a sectional view showing a step subsequent to FIG. 27 in the method for manufacturing a thin-film magnetic element of the present invention;

FIG. 29 is a conceptual diagram of a hysteresis loop of a synthetic ferrifree type free magnetic layer,

FIG. 30 is a schematic explanatory view for explaining a spin filter effect by a backed layer,

FIG. 31 is a schematic explanatory view for explaining a spin filter effect by a backed layer,

FIG. 32 is a schematic explanatory view for explaining a specular reflection effect by a specular reflection layer,

FIG. 33 is a schematic explanatory view for explaining a specular reflection effect by a specular reflection layer,

FIG. 34 is a cross-sectional view of a conventional thin film magnetic element.

[Explanation of symbols]

 Reference Signs List 11 substrate 12 first antiferromagnetic layer 13 fixed magnetic layer 13a first fixed magnetic layer 13b nonmagnetic intermediate layer 13c second fixed magnetic layer 14 nonmagnetic material layer 15, 31 free magnetic layer 16 nonmagnetic layer 31a first free magnetism Layer 31b Non-magnetic intermediate layer 31c Second free magnetic layer 17 Other antiferromagnetic layers 18, 41 Vertical bias layer 19, 42 Electrode layer

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01F 41/14 H01F 41/14 H01L 43/12 H01L 43/12 (72) Inventor Toshihiro Kuriyama Ota, Tokyo 1-7 Yukitani-Otsuka-ku Alps Electric Co., Ltd. (72) Inventor Eiji Umezu 1-7 Yukitani-Otsuka, Ota-ku, Tokyo Alps Electric Co., Ltd. (72) Inventor Ken-ichi Tanaka 1-7 Yukitani-Otsuka, Ota-ku, Tokyo No. Alps Electric Co., Ltd. (72) Inventor Yosuke Ide 1-7 Yukitani Otsuka, Ota-ku, Tokyo Alps Electric Co., Ltd. F-term (reference) 5D034 BA04 CA04 CA08 DA07 5E049 AA04 AC05 BA16 BA25 FC06 FC08

Claims (33)

[Claims] (A) forming a multilayer film having a first antiferromagnetic layer, a pinned magnetic layer, a nonmagnetic material layer, and a free magnetic layer on a substrate; and (b) forming the multilayer film on a substrate. Annealing at a heat treatment temperature of 1 in a magnetic field of a first magnitude to fix the magnetization direction of the fixed magnetic layer in a predetermined direction by annealing in a magnetic field;
(C) forming a second antiferromagnetic layer on the multilayer film; and (d) forming a multilayer film on which the second antiferromagnetic layer is laminated.
Fixing the magnetization direction of the free magnetic layer in a direction orthogonal to the magnetization direction of the fixed magnetic layer by annealing in a magnetic field at a second heat treatment temperature and a second magnitude magnetic field. A method of manufacturing a thin film magnetic element. 2. The method according to claim 1, wherein in the step (d), the second heat treatment temperature is set to a temperature lower than a blocking temperature of the first antiferromagnetic layer. 3. The method according to claim 1, wherein in the step (d), the magnitude of the second magnetic field is smaller than the exchange anisotropic magnetic field of the first antiferromagnetic layer. . 4. The method of manufacturing a thin-film magnetic element according to claim 1, wherein in the step (a), a step of laminating another antiferromagnetic layer on the uppermost layer of the multilayer film is performed. 5. The method according to claim 4, wherein the other antiferromagnetic layer is a specular reflection layer that extends a mean free path of conduction electrons by a specular reflection effect. 6. The method of manufacturing a thin-film magnetic element according to claim 5, wherein the specular reflection layer is made of a material capable of forming an energy gap having a high probability of causing specular reflection for preserving the spin state of conduction electrons. 7. The method according to claim 6, wherein the specular reflection layer is made of a semi-metallic Heusler alloy. 8. The metallurgical whistler alloy is made of NiM
8. The method for manufacturing a thin-film magnetic element according to claim 7, wherein the thin-film magnetic element is constituted by at least one of a single layer film and a multilayer film of nSb and PtMnSb. 9. The method of manufacturing a thin-film magnetic element according to claim 4, wherein the thickness of the other antiferromagnetic layer is greater than 0 and equal to or less than 30 °. 10. The method of manufacturing a thin-film magnetic element according to claim 9, wherein the thickness of said another antiferromagnetic layer is 10 ° or more and 30 ° or less. 11. The film thickness of the free magnetic layer is 15 to 4
The method for manufacturing a thin-film magnetic element according to any one of claims 1 to 10, wherein the angle is set within a range of 5 °. 12. The method according to claim 1, wherein, in the step (a), a nonmagnetic layer is stacked in contact with a surface of the free magnetic layer that is farther from the nonmagnetic material layer than the upper surface or the lower surface.
12. The method for manufacturing a thin-film magnetic element according to any one of claims 11 to 11. 13. The manufacturing of the thin-film magnetic element according to claim 12, wherein the magnetization direction of the free magnetic layer is directed in a direction crossing the magnetization direction of the fixed magnetic layer by RKKY coupling with the second antiferromagnetic layer. Method. 14. The method according to claim 12, wherein the nonmagnetic layer is formed of a conductive material. 15. The non-magnetic layer is made of Ru, Cu, Ag, A
The method for manufacturing a thin-film magnetic element according to claim 12, wherein the thin film magnetic element is formed using one or more elements of u. 16. The non-magnetic layer is formed of Ru,
The method for manufacturing a thin-film magnetic element according to claim 15, wherein the thickness is 8 to 11 °. 17. In the step (a), the multilayer film is formed by stacking a first antiferromagnetic layer, a fixed magnetic layer, a nonmagnetic material layer, and a free magnetic layer in this order from the substrate side,
In the step (c), a lift-off resist layer having a cutout formed on the lower surface is formed on the free magnetic layer, and after the second antiferromagnetic layer is formed on the multilayer film, 17. The method according to claim 1, wherein the resist layer is removed from the multilayer film.
The method for manufacturing a thin-film magnetic element according to any one of the above. 18. After the second antiferromagnetic layer is formed, a pair of resists is stacked on the second antiferromagnetic layer at intervals of a track width, and a pair of resists is stacked on the second antiferromagnetic layer. The method for manufacturing a thin-film magnetic element according to claim 17, wherein a portion sandwiched by the resist is shaved and removed in a direction perpendicular to a substrate surface. 19. In the step (c), after forming the second antiferromagnetic layer on the multilayer film, a pair of resists are laminated at intervals of a track width to form the second antiferromagnetic layer. 17. The method for manufacturing a thin-film magnetic element according to claim 1, wherein a concave portion is formed by shaving a portion of the magnetic layer sandwiched by the resist in a direction perpendicular to a substrate surface. 20. The method according to claim 19, wherein the recess is formed such that a bottom surface of the recess is located in the second antiferromagnetic layer. 21. The thickness of the region of the second antiferromagnetic layer located below the bottom surface of the concave portion, or the thickness of the region of the second antiferromagnetic layer located below the bottom surface of the concave portion and the other region. 21. The method of manufacturing a thin-film magnetic element according to claim 20, wherein the total thickness of the regions of the antiferromagnetic layer is set to be larger than 0 and equal to or smaller than 30 degrees. 22. The method according to claim 19, wherein another antiferromagnetic layer is formed on the uppermost layer of the multilayer film, and the concave portion is formed such that a bottom surface of the concave portion is located in the other antiferromagnetic layer. Method for manufacturing a thin film magnetic element. 23. The method of manufacturing a thin film magnetic element according to claim 22, wherein the thickness of the region of the other antiferromagnetic layer located below the bottom surface of the concave portion is set to be larger than 0 and equal to or smaller than 30 °. 24. In the step (a), a nonmagnetic layer is laminated on the upper or lower surface of the free magnetic layer in contact with a surface remote from the nonmagnetic material layer, and a bottom surface of the concave portion is formed. 20. The method according to claim 19, wherein the concave portion is formed such that the concave portion is located in the nonmagnetic layer. 25. In the step (a), the fixed magnetic layer is formed by laminating a plurality of ferromagnetic material layers having different magnetic moments per unit area via a non-magnetic intermediate layer. A method for manufacturing a thin-film magnetic element according to any one of claims 1 to 24. 26. In the step (a), the free magnetic layer is formed by laminating a plurality of ferromagnetic material layers having different magnetic moments per unit area via a nonmagnetic intermediate layer. A method for manufacturing a thin-film magnetic element according to claim 1. 27. The non-magnetic intermediate layer is made of Ru, Rh, I
27. The method of manufacturing a thin-film magnetic element according to claim 25, wherein the thin-film magnetic element is formed of one or more alloys of r, Cr, Re, and Cu. 28. The method according to claim 26, wherein at least one of the plurality of ferromagnetic material layers is formed of a magnetic material having the following composition. The composition formula is represented by CoFeNi, wherein the composition ratio of Fe is 9 atom% or more and 17 atom% or less, the composition ratio of Ni is 0.5 atom% or more and 10 atom% or less, and the remaining composition ratio is Co. . 29. A structure in which C is present between the ferromagnetic material layer and the non-magnetic material layer stacked closest to the non-magnetic material layer.
28. The method of manufacturing a thin film magnetic element according to claim 26, wherein an intermediate layer made of an oFe alloy or Co is formed. 30. The method according to claim 29, wherein at least one of the plurality of ferromagnetic material layers is formed of a magnetic material having the following composition. The composition formula is CoFe
Indicated by Ni, the composition ratio of Fe is not less than 7 atomic% and not more than 15 atomic%, the composition ratio of Ni is not less than 5 atomic% and not more than 15 atomic%, and the remaining composition ratio is Co. 31. The method according to claim 28, wherein all of the plurality of ferromagnetic material layers are formed of the CoFeNi. 32. The thin-film magnetic element according to claim 1, wherein the first antiferromagnetic layer and the second antiferromagnetic layer are formed using antiferromagnetic materials having the same composition. Method. 33. The first antiferromagnetic layer and / or the first
2 is made of a PtMn alloy or X-Mn
(However, X is Pd, Ir, Rh, Ru, Os, Ni,
Fe or an alloy of Pt—Mn—X ′ (where X ′ is Pd,
Ir, Rh, Ru, Au, Ag, Os, Cr, Ni, A
33. The method for manufacturing a thin-film magnetic element according to any one of claims 1 to 32, wherein the thin-film magnetic element is formed of an alloy (which is one or more of r, Ne, Xe, and Kr).