JP2003317215A - Magnetic reproducing head and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic reproducing head having high bias point controllability, a high magnetic reluctance change rate, good soft magnetic characteristics, good thermal stability, and high output performance, and coping with superhigh density recording, and its manufacturing method. <P>SOLUTION: A seed layer, a buffer layer made of a material for increasing magneto-resistive effects, a free layer, a first nonmagnetic spacer layer, a fixed layer having a multilayer structure, a fixing operation layer, and a protective layer are formed in this order on a substrate. Annealing is performed in an entire first magnetic field to fix the magnetization direction of the fixed layer, then annealing is performed in an entire second magnetic field lower than the first magnetic field to return the magnetization direction of the free layer to an initial state. Thus, the magnetic reproducing head having high bias point controllability, a high GMR ratio, good soft magnetic characteristics, thermal stability, high output performance, and coping with the superhigh density recording can be obtained. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic reproducing head including a pinned layer whose magnetization direction is magnetically fixed, and a method for manufacturing the same.

[0002]

2. Description of the Related Art In early magnetic reproducing heads, by utilizing the anisotropic magnetoresistive (AMR) effect exhibited by a ferromagnetic material such as permalloy (nickel-iron alloy), a medium such as a disk or a tape can be formed. The data recorded magnetically was read and reproduced. The AMR effect is a change in the electrical resistance r of a specific magnetic material due to an external magnetic field. In this case, the electric resistance r is proportional to the angle formed by the magnetization direction of this magnetic material and the direction of the current flowing through this magnetic material. To reproduce a magnetically encoded recording medium such as a disk or tape, the following is performed.
That is, the magnetization direction in the reproducing head is changed by rotating the recording medium and changing the magnetic field. At this time, a resistance change due to the AMR effect occurs, which is sensed by an appropriate circuit and reproduced as information on the recording medium.

However, a slight resistance change caused by the AMR effect, that is, Dr / r (Dr represents the difference between the resistance in the anisotropic magnetic field Hk and the resistance when the magnetic field is zero).
Is only a few percent at the maximum. Therefore, it is difficult to accurately detect the resistance change described above. This is one of the drawbacks of the AMR effect.

From the late 1980s to the early 1990s, Giant Magnetoresista (GMR)
nce) effect was discovered and immediately applied to magnetic read head technology. A magnetic reproducing head utilizing the GMR effect has a thin thickness of about 2 nm to 8 nm.
It has a laminated body including one ferromagnetic layer and a further thin (about 2 to 3 nm thick) conductive nonmagnetic layer provided so as to separate the two ferromagnetic layers. GM
The R effect means a ferromagnetic state (state in which the magnetization directions of the two ferromagnetic layers are parallel to each other) due to exchange interaction between spins of the two ferromagnetic layers in the stacked body of the magnetic reproducing head as described above. This is the effect obtained from the phenomenon that the antiferromagnetic state (the magnetization directions of the two ferromagnetic layers are antiparallel to each other). When a current is applied to such a stack, the electrons passing through the stack undergo spin-dependent scattering at the interface between the conductive nonmagnetic layer and the ferromagnetic layer. Therefore, the magnetoresistive effect is much higher when the stacked body is in the antiferromagnetic state than when it is in the ferromagnetic state. Moreover,
Although the change in resistance value is slight, it is much larger than the change in resistance value due to the AMR effect exhibited by the individual magnetic layers.

Immediately after the GMR effect was discovered, a spin valve magnetoresistive effect (SVMR: Spin Valve Magnetoresist)
A kind of GMR effect called ance) was discovered and introduced into the reproducing head. This SVM is a kind of GMR effect
The R effect is exhibited by the following laminated body. The laminated body includes two ferromagnetic layers formed of, for example, a cobalt iron alloy or a nickel iron alloy, and a thin film formed of a conductive nonmagnetic material (eg, copper) so as to separate the two ferromagnetic layers, The antiferromagnetic layer is formed adjacent to one of the two ferromagnetic layers. One of the ferromagnetic layers is a pinned layer whose magnetization direction is fixed, and the magnetization direction is pinned by the exchange coupling magnetic field of the antiferromagnetic layer formed adjacent to this pinned layer. The other ferromagnetic layer is a free layer whose magnetization direction is not fixed. A small change in the external magnetic field occurs due to the movement of the magnetic medium during reproduction of information from the magnetic medium, and the magnetization direction of the free layer rotates in response to this change. However, the magnetization direction in one pinned layer is not affected by this small change. In this way, when the magnetization direction of the free layer rotates and becomes different from the magnetization direction of the pinned layer, the magnetoresistive effect of the stacked body changes.

The spin valve structure is now one of the important components forming a magnetic read head.
In recent patents, various novel materials are applied to form a pinned layer or pinned action layer exhibiting ferromagnetism or antiferromagnetism, and the number, arrangement, or area of layers are changed to make a spin valve. There is a tendency that many inventions improve the sensitivity and stability of the structure. In this connection, Kana
U.S. Pat. No. 5,896,252 by i to a spin valve magnetoresistive effect (SVM) incorporating a free layer in a two-layer structure consisting of a cobalt iron alloy layer and a nickel iron alloy layer.
R) A method of forming a head is disclosed. Also, in US Pat. No. 5,701,223 by Fontana Jr. et al., A method of manufacturing a spin valve magnetoresistive sensor using a pinned layer that is coupled to an antiferromagnetic exchange bias layer and is antiparallelly arranged by magnetic exchange coupling. Is disclosed. This pinned layer comprises two ferromagnetic films separated by a non-magnetic exchange coupling layer.

US Pat. No. 5,852,531 to Yamada discloses a method of manufacturing a spin valve magnetoresistive effect (SVMR) head with reduced asymmetry in response characteristics. In this SVMR head, the giant magnetoresistive (GMR) effect caused by the change in the magnetization direction between the pinned layer and the free layer and the anisotropy caused by the angle formed by the magnetization direction of the single free layer and the current direction. The asymmetry is reduced by competing with the anti-reluctance (AMR) effect. Further, US Pat. No. 5,920,446 to Gill discloses a method of forming a super high density GMR head using two free layers without using the free layer, the fixed layer and the fixed working layer. With such a structure, the thickness of the entire reproducing head is reduced, and a reproducing head suitable for reading information on a medium having a higher recording density can be obtained. Also, the two free layers in this structure are each a stack including two ferromagnetic layers coupled in an antiparallel arrangement via a spacer layer.
When a sense current flows in the laminated body having such a structure,
A bias magnetic field necessary for determining the magnetization direction of the free layer is generated, and the magnetization direction of at least one of the free layers changes. This causes the resistance change necessary for reading.

[0008]

By the way, the recording density of a magnetic recording medium such as a hard disk is increasing, and at present, 35 gigabits per square inch (3
5 Gbits / inch ² ≈5.43 Gbits / cm
^The momentum exceeds ² ). Therefore, in the future, in designing or manufacturing a spin valve magnetoresistive effect (SVMR) reproducing head, further improvement is required so as to be compatible with the above-mentioned ultra-high density recording medium.
Specifically, to read the information on the ultra high density recording medium,
It is necessary to further reduce the read gap of the reproducing head, and accordingly, it is necessary to make improvements such as making the magnetic layer thinner or reducing the number of magnetic layers. However, reducing the thickness of these layers makes it increasingly difficult to control the bias point, resulting in a GMR ratio (Dr /
r) decreases, and good soft magnetism cannot be obtained sufficiently. As a result, the output performance of the reproducing head is lowered and reliability is lost. In addition, the above-mentioned S currently manufactured
The VMR sensor is suitable for a recording density of several gigabits per square inch (about 0.16 to 1.55 Gbits / cm ² ), but the heat required to accurately reproduce information from a high density recording medium. It does not have physical properties such as stability.

The present invention has been made in view of the above problems, and a first object thereof is to easily control a bias point and maintain a high magnetoresistive effect change rate (Dr / r).
It is an object of the present invention to provide a magnetic reproducing head capable of obtaining excellent soft magnetism and a manufacturing method thereof.

A second object of the present invention is 35 Gbits /
It is an object of the present invention to provide a magnetic reproducing head suitable for reproducing a magnetic recording medium corresponding to ultra high density recording of inch ² (≈5.43 Gbits / cm ² ) or more, and a manufacturing method thereof.

A third object of the present invention is to provide a magnetic reproducing head having excellent controllability of a bias point, stability against heat and high output performance, and a method of manufacturing the same.

[0012]

A method of manufacturing a magnetic reproducing head according to the present invention is a method of manufacturing a magnetic reproducing head having a spin valve structure corresponding to an ultrahigh recording density, in which a seed layer is formed on a substrate. And a second step of forming a buffer layer on the seed layer by using a material that increases the magnetoresistive effect, and a ferromagnetic material on the buffer layer so that the magnetization direction is free. Third to form a free layer that rotates around
And the first step using a non-magnetic material on this free layer.
The fourth step of forming the non-magnetic spacer layer of
A fifth step of forming a pinned layer having a laminated structure on the non-magnetic spacer layer, a sixth step of forming a pinning layer on the pinned layer, and a step of forming the pinning layer on the pinning layer; A seventh step of forming the protective layer, an eighth step of fixing the magnetization direction of the fixed layer by annealing the whole in a first magnetic field, and a whole step of lowering the magnetization direction lower than the first magnetic field. Two
And a ninth step of returning the magnetization direction of the free layer to the initial state by performing the annealing treatment in the magnetic field.

According to the method of manufacturing the magnetic reproducing head of the present invention,
On the seed layer, a buffer layer made of a material that increases the magnetoresistive effect, a free layer made of a ferromagnetic material, in which the magnetization direction freely rotates, a first non-magnetic spacer layer made of a non-magnetic material, and a pinned layer. Since the layer and the fixed action layer are formed in this order, the magnetoresistance change rate when an external magnetic field is applied is improved. In the subsequent step, the magnetization direction of the pinned layer is fixed by subjecting the whole to an annealing treatment in the first magnetic field, so that the change in the magnetization direction of the pinned layer due to the external magnetic field can be suppressed. In the subsequent step, the magnetization direction of the free layer is returned to the initial state by subjecting the whole to an annealing treatment in a second magnetic field lower than the first magnetic field.
The magnetic field required for magnetization in the hard axis direction in the free layer can be reduced.

The magnetic reproducing head of the present invention is a spin-valve type magnetic reproducing head corresponding to an ultrahigh recording density,
A substrate, a seed layer formed on the substrate, a buffer layer formed on the seed layer and made of a material that increases the magnetoresistive effect, and a ferromagnetic material formed on the buffer layer and having a magnetization direction of A freely rotating free layer, a first non-magnetic spacer layer made of a non-ferromagnetic material formed on the free layer, and an annealing in a first magnetic field formed on the first non-magnetic spacer layer. A pinned layer having a laminated structure in which the magnetization direction is pinned by treatment, a pinning layer formed on the pinned layer, and a protective layer formed on the pinning layer. is there.

In the magnetic reproducing head of the present invention, a seed layer, a buffer layer formed on the seed layer and made of a material for increasing the magnetoresistive effect, and a ferromagnetic material formed on the buffer layer and having a magnetization direction. Are freely rotated, a first non-magnetic spacer layer made of a non-ferromagnetic material formed on the free layer, and a first non-magnetic spacer layer formed on the first non-magnetic spacer layer in a first magnetic field. A fixed layer having a laminated structure in which the magnetization direction is fixed by performing an annealing treatment, a fixed action layer formed on the fixed layer, and a protective layer formed on the fixed action layer are provided. Therefore, a high magnetoresistance change rate can be obtained when an external magnetic field is applied. Furthermore, it is possible to suppress a change in the magnetization direction of the pinned layer due to an external magnetic field.

In the method of manufacturing the magnetic reproducing head of the present invention,
In the first step, the seed layer may be formed to have a thickness of 4 nm or more and 7 nm or less by using at least one kind of nickel chromium (NiCr) alloy and nickel iron chromium (NiFeCr) alloy.

In the method of manufacturing the magnetic reproducing head of the present invention,
In the second step, a buffer layer is formed by using at least one selected from the group consisting of ruthenium (Ru), rhodium (Rh) and iridium (Ir) so as to have a thickness of 0.3 nm or more and 2.5 nm or less. It may be formed.

In the method of manufacturing the magnetic reproducing head of the present invention,
In the third step, using a cobalt iron (CoFe) alloy or a cobalt iron boron (CoFeB) alloy,
The free layer may be formed to have a thickness of 1.0 nm or more and 6.0 nm or less.

In the method of manufacturing the magnetic reproducing head of the present invention,
In the fourth step, using copper (Cu), 1.8 nm
The spacer layer may be formed to have a thickness of not less than 3.0 nm.

In the method of manufacturing the magnetic reproducing head of the present invention,
In the fifth step, the first ferromagnetic layer, the second non-magnetic spacer layer, and the second ferromagnetic layer are laminated in this order, and the pinned layer is formed so as to be ferromagnetically coupled. May be. In this case, a cobalt iron alloy is used to form the first ferromagnetic layer so as to have a thickness of 0.8 nm or more and 2.0 nm or less, and a nickel chromium alloy is used to form the first ferromagnetic layer of 0.2 nm or more and 0.5 nm or less. It is desirable to form the second non-magnetic spacer layer so as to have a thickness and use a cobalt iron alloy to form the second ferromagnetic layer so as to have a thickness of 0.4 nm or more and 1.0 nm or less. Further, in this case, it is desirable to form the first and second ferromagnetic layers so that the thickness ratio is 2: 1.

In the method of manufacturing the magnetic reproducing head of the present invention,
In the fifth step, the first ferromagnetic layer, the second nonmagnetic spacer layer, and the second ferromagnetic layer are laminated in this order to form the pinned layer having ferromagnetic coupling. In this case, using any one of the group consisting of cobalt (Co), cobalt iron alloy, cobalt iron boron alloy and nickel iron alloy (NiFe), the thickness should be 0.8 nm or more and 2.0 nm or less. A first ferromagnetic layer is formed on the first ferromagnetic layer, and at least one of a nickel-chromium alloy and a nickel-iron-chromium alloy is used, and the thickness is 0.2 nm or more.
The second nonmagnetic spacer layer is formed to have a thickness of 5 nm or less, and 0.4 nm or more is formed by using at least one selected from the group consisting of cobalt, cobalt iron alloy, cobalt iron boron alloy, and nickel iron alloy. The second ferromagnetic layer may be formed to have a thickness of 1.0 nm or less. In this case, it is desirable to form the first and second ferromagnetic layers so that the thickness ratio is 2: 1.

In the method of manufacturing the magnetic reproducing head of the present invention,
In the sixth step, using at least one of a manganese platinum (MnPt) alloy and a manganese platinum palladium (MnPtPd) alloy, 10.0 nm or more and 30.
The fixing action layer may be formed to have a thickness of 0 nm or less. Alternatively, iridium manganese (Ir
The Mn) alloy may be used to form the fixing layer with a thickness of 5.0 nm or more and 15.0 nm or less.

In the method of manufacturing the magnetic reproducing head of the present invention,
In the seventh step, using at least one member selected from the group consisting of nickel chromium alloy, nickel iron chromium alloy, and tantalum (Ta), 2.0 nm or more and 5.0 nm or more.
The protective layer may be formed to have the following thickness.

In the method of manufacturing the magnetic reproducing head of the present invention,
In the eighth step, 2000 / (4π) × 10 ³ A /
Annealing may be performed at a temperature of 280 ° C. for 5 hours in a lateral magnetic field of m.

In the method of manufacturing the magnetic reproducing head of the present invention,
In the ninth step, annealing may be performed at a temperature of 290 ° C. for 30 minutes in a vertical magnetic field of 50 / (4π) × 10 ³ A / m.

In the magnetic reproducing head of the present invention, the seed layer is made of either a nickel chromium (NiCr) alloy or a nickel iron chromium (NiFeCr) alloy, and has a thickness of 4.0 nm or more and 7.0 nm or less. May be.

In the magnetic reproducing head of the present invention, the buffer layer is
It may be made of any one selected from the group consisting of ruthenium (Ru), rhodium (Rh), and iridium (Ir), and may have a thickness of 0.3 nm or more and 2.5 nm or less.

In the magnetic reproducing head of the present invention, the free layer may be made of a cobalt iron (CoFe) alloy or a cobalt iron boron (CoFeB) alloy and have a thickness of 1.0 nm or more and 6.0 nm or less. .

In the magnetic reproducing head of the present invention, the first non-magnetic spacer layer is made of copper (Cu) and has a thickness of 1.8n.
You may make it have a thickness of m or more and 3.0 nm or less.

In the magnetic reproducing head of the present invention, the pinned layer has a ferromagnetic coupling structure in which the first ferromagnetic layer, the second non-magnetic spacer layer, and the second ferromagnetic layer are sequentially laminated. Is desirable.

In the magnetic reproducing head of the present invention, the first ferromagnetic layer contains at least one selected from the group consisting of cobalt (Co), cobalt iron alloy, cobalt iron boron alloy and nickel iron (NiFe) alloy. Composed of 0.8
The second non-magnetic spacer layer has a thickness of not less than 2.0 nm and not more than 2.0 nm, and is configured to include at least one of a nickel-chromium alloy and a nickel-iron-chromium alloy.
The second ferromagnetic layer has a thickness of 2 nm or more and 0.5 nm or less and is configured to include at least one of cobalt, a cobalt iron alloy, a cobalt iron boron alloy, and a nickel iron alloy, and 0.4 nm or more. You may make it have a thickness of 1.0 nm or less. In this case, it is desirable that the first and second ferromagnetic layers have a thickness ratio of 2: 1.

In the magnetic reproducing head of the present invention, the fixed action layer is made of a manganese platinum (MnPt) alloy or a manganese platinum palladium (MnPtPd) alloy.
It may have a thickness of 0.0 nm or more and 30.0 nm or less, or may be made of an iridium manganese (IrMn) alloy and have a thickness of 5.0 nm or more and 15.0 nm or less.

In the magnetic reproducing head of the present invention, the protective layer is
It may be configured to include at least one selected from the group consisting of a nickel chromium alloy, a nickel iron chromium alloy, and tantalum (Ta), and have a thickness of 2.0 nm or more and 5.0 nm or less.

In the magnetic reproducing head of the present invention, the fixed layer is annealed at a temperature of 280 ° C. for 5 hours in a lateral magnetic field of 2000 / (4π) × 10 ³ A / m. It is desirable that it be one.

In the magnetic reproducing head of the present invention, the free layer was annealed at a temperature of 290 ° C. for 30 minutes in a vertical magnetic field of 50 / (4π) × 10 ³ A / m. It is desirable to be one.

[0036]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below in detail with reference to the drawings.

First, the structure of a magnetic reproducing head according to an embodiment of the present invention will be described with reference to FIG.

FIG. 1 shows a sectional structure of a main part of the magnetic reproducing head according to the present embodiment. This magnetic reproducing head includes, for example, a seed layer 12, a buffer layer 14, a top spin valve structure 32, and a protective layer 30 on a substrate 10.
And includes a structure laminated in this order.

The substrate 10 is, for example, 0.02 or more and 0.0.
Aluminum oxide having a thickness of 4 μm or less (Al ₂ O
₃ ; hereinafter referred to as "alumina". ). The seed layer 12 is, for example, nickel chrome (Ni
Cr) alloy or nickel iron chromium (NiFeCr)
It is composed of an alloy and has a thickness of 4.0 nm or more and 7.0 nm.
The following is desirable. The subsequent buffer layer 14 has a function of increasing the magnetoresistive effect. This buffer layer 14 is
For example, it is made of ruthenium (Ru), rhodium (Rh), iridium (Ir), or the like, and the thickness thereof is preferably 0.3 nm or more and 2.5 nm or less, and more preferably 0.5 nm.

The top spin valve structure (hereinafter, simply referred to as "SV structure") 32 has a free layer 16, a nonmagnetic layer 18, a pinned layer 20, and a pinning layer 28 laminated in this order. It has a structure as described above, and is generally called a "single top spin valve type". The “top” of the top spin valve means the side where the fixed layer 20 is far from the substrate 10 with the free layer 16 in between, that is, the substrate 1
When 0 is set to the bottom, it means that the fixed layer 20 is on the upper side of the free layer 16. Here, the nonmagnetic layer 18 corresponds to a specific but not limitative example of “first nonmagnetic spacer layer” in the present embodiment.

The free layer 16 is made of a ferromagnetic material such as cobalt iron (CoFe) alloy or cobalt iron boron (C).
It is composed of an oFeB) alloy or the like, and the magnetization direction is freely rotated according to the signal magnetic field generated by the magnetic recording medium or the like. The preferred thickness of the free layer 16 is
It is 1.0 nm or more and 6.0 nm or less, and more preferably 2 nm. The nonmagnetic layer 18 is made of a nonferromagnetic conductive material, such as copper (Cu), and has a preferable thickness of 1.8 nm or more and 3.0 nm or less. The pinned layer 20 includes a first ferromagnetic layer 22, a nonmagnetic layer 24, and a second ferromagnetic layer 22.
Of the first and second ferromagnetic layers 26 are laminated in this order.
The ferromagnetic layers 22 and 26 are ferromagnetically coupled. Here, the nonmagnetic layer 24 corresponds to a specific example of "a second nonmagnetic spacer layer" in the invention.

The first ferromagnetic layer 22 is made of, for example, CoFe.
Alloy, NiFe alloy, cobalt (Co), or Co
It is made of FeB alloy or the like, and the thickness thereof is preferably 0.8 nm or more and 2.0 nm or less, and more preferably 1.1 nm. The nonmagnetic layer 24 has a thickness of, for example, preferably 0.2 nm or more and 0.5 nm or less, more preferably 0.35 nm, and is made of NiCr alloy or N.
It is composed of an iFeCr alloy or the like. Further, the second ferromagnetic layer 26 is similar to the first ferromagnetic layer 22, for example,
It is composed of a CoFe alloy, a NiFe alloy, cobalt (Co), a CoFeB alloy, or the like. The thickness is preferably 0.4 nm or more and 1.0 nm or less,
More preferably, it is 0.5 nm. The first and second ferromagnetic layers 22 and 26 are made of CoFe alloy, NiF as described above.
When it is composed of an e alloy, cobalt or a CoFeB alloy, the thickness ratio of the first ferromagnetic layer 22 and the second ferromagnetic layer 26 is preferably 2: 1. When the first and second ferromagnetic layers 22 and 26 are formed with this ratio,
The performance of the fixed layer 20 is effectively exhibited.

The fixed action layer 28 fixes the magnetization direction of the fixed layer 20 by exchange coupling. The fixing layer 28 is preferably made of a material having a high blocking temperature, a high exchange bias magnetic field (Hex) and excellent corrosion resistance. For example, manganese platinum (MnPt) alloy or manganese platinum palladium (M
nPtPd) alloy or the like. When composed of the above materials, the thickness is preferably 10.0 nm or more and 30.0 nm or less, and particularly preferably 20.0 nm. Alternatively, the fixing action layer 28 may be made of an iridium manganese (IrMn) alloy, and in this case, it is desirable that the thickness is 5.0 nm or more and 15.0 nm or less.

The protective layer 30 is made of, for example, NiCr alloy or N.
It is made of an iFeCr alloy, tantalum (Ta), or the like, and preferably has a thickness of 2.0 nm or more and 5.0 nm or less, more preferably 3.0 nm.

A more preferable example of the structure of the main part of the magnetic reproducing head according to this embodiment can be summarized as follows: Seed layer 1
2 to protective layer 30 in the order of stacking "NiCr (nickel chrome alloy) (X1) / Ru (ruthenium) (X2) / C
oFe (cobalt iron alloy) (X3) / Cu (copper) (X
4) / CoFe (X5) / NiCr (X6) / CoFe
(X7) / MnPt (manganese platinum alloy) (X8) / N
iCr (X9) ”. Here, X1 shown in parentheses
To X9 are the thickness ranges of the respective layers, and their specific numerical values are as shown in Table 1.

[0046]

[Table 1]

In the magnetic reproducing head of this embodiment, the SV is provided by the ferromagnetic layer (not shown) provided in the magnetic reproducing head.
When a sense current flows through the SV structure 32 through a conductive lead layer (not shown) with a longitudinal bias applied to the structure 32, a giant magnetoresistive (GMR) effect occurs. By utilizing this GMR effect, the signal magnetic field recorded on the magnetic recording medium is detected by the SV structure 32, whereby information is reproduced.

Next, with reference to FIG. 1, a method of manufacturing the magnetic reproducing head according to the present embodiment will be described. In addition,
The material, layer thickness, structural characteristics, and the like of each component of the magnetic reproducing head have already been described in detail, and will be appropriately omitted below.

The magnetic reproducing head according to the present embodiment is formed by laminating each layer on the substrate 10 by utilizing the existing film forming method, for example, DC magnetron sputtering, as follows. Specifically, first, the substrate 10
To prepare. Then, on this substrate 10, a seed layer 12,
Formed by laminating the buffer layer 14, the free layer 16, the nonmagnetic layer 18, the first ferromagnetic layer 22, the nonmagnetic layer 24, the second ferromagnetic layer 26, the pinned layer 28, and the protective layer 30 in this order. To do.

Subsequently, the laminated body formed by the above steps, that is, the laminated body including the substrate 10 to the protective layer 30 is annealed. First, in this stack,
That is, an annealing process is performed by applying a first magnetic field higher than a second magnetic field described below in the in-plane direction of the stack. The annealing treatment in this first magnetic field is 2000 / (4π) × 1
280 ° C for 5 hours in a magnetic field of 0 ³ A / m
It is preferable to carry out under the temperature of. As a result, the magnetization direction of the fixed layer 20 is fixed.

After performing the annealing treatment in the first magnetic field, the annealing treatment in the second magnetic field lower than the first magnetic field is further performed. In this case, the second magnetic field is applied in the vertical direction, that is, the stacking direction. It is preferable that the annealing treatment in the second magnetic field is performed at a temperature of 290 ° C. for 30 minutes in a magnetic field of 50 / (4π) × 10 ³ A / m. As a result, the magnetization direction of the free layer 16 returns to the initial state. With the above, the main part structure of the magnetic reproducing head is completed.

As described above, in the magnetic reproducing head and the method of manufacturing the same according to the present embodiment, the SV structure 3 is used.
Since the buffer layer 14 made of a material that increases the magnetoresistive effect is formed between the second magnetic layer 2 and the seed layer 12, the bias point can be easily controlled while reducing the overall thickness of the magnetic read head. A high soft magnetic property can be obtained while maintaining a high GMR ratio.

That is, as described above in the section "Problems to be Solved by the Invention", in the conventional magnetic reproducing head, when the thickness of the magnetic layer of the magnetic reproducing head is reduced, it becomes difficult to control the bias point. However, the GMR ratio (Dr / r) was lowered, and sufficient soft magnetism could not be obtained. On the other hand, in this embodiment, as is clear from the examples described later, in the structure of the magnetic reproducing head, since the buffer layer 14 is provided adjacent to the free layer 16, the buffer layer 14 and the free layer 16 are not provided. The conduction electrons are totally reflected at the boundary with the layer 16. When the conduction electrons are totally reflected, spin-dependent scattering of conduction electrons occurs at the boundary between the buffer layer 14 and the free layer 16, and as a result, the magnetoresistance change rate Dr / Dr due to the GMR effect.
r increases. Therefore, even if the free layer 16 is thinned, the magnetoresistance change rate Dr / r does not decrease unlike the conventional case. Therefore, the magnetic reproducing head according to the present embodiment can detect even if the magnetic signal from the recording medium becomes weaker than before due to the high recording density. In particular, 0.3 nm or more and 2.5 n made of ruthenium shown in Table 1
The advantages described above are more effectively exhibited in the buffer layer 14 having a thickness of m or less and the free layer 16 made of a CoFe alloy and having a thickness of 1.0 nm or more and 6.0 nm or less.

Further, since the buffer layer 14 is formed under the free layer 16, the stability of the free layer 16 against heat is enhanced, and very preferable magnetic properties, particularly soft magnetism and unidirectionality of magnetization are obtained. Is obtained. Therefore, the control of the bias point becomes easier, and the sensitivity to the magnetic signal is further improved.

Further, the pinned layer 20 of the present embodiment has a ferromagnetic coupling structure once the magnetization direction is once determined by performing the annealing treatment in the first magnetic field, and the magnetization direction is substantially constant. Retained as is. In particular,
As will be apparent from Examples described later, the pinned layer 20 formed of the combination of "CoFe alloy / NiCr alloy / CoFe alloy" has very high reliability in terms of stability in the magnetization direction.

Further, since the magnetic reproducing head has a smaller number of layers than the conventional structure, and therefore the entire thickness of the head is thinner than that of the conventional structure, reading of magnetic data recorded at ultra high density is possible. The readability of the magnetic reproducing head is improved. Further, since the structure of the magnetic reproducing head is simple, the forming process is further simplified, and the magnetic reproducing head can be formed efficiently and economically.

[0057]

EXAMPLES Specific examples of the magnetic reproducing head according to the present embodiment will be described in detail.

First, the magnetic characteristics of the free layer 16 in the magnetic reproducing head of the present embodiment in which the buffer layer 14 was introduced were examined. The results are shown in Table 2.

[0059]

[Table 2]

Table 2 shows the experimental results for clarifying the magnetic characteristics of the free layer 16, where "Bs (nWb)" is the magnetic moment of the free layer 16 and "Hc (A / m)".
Is the coercive force of the free layer 16, “Hk (A / m)” is the anisotropic magnetic field, “Rs (Ω / □)” is the sheet resistance, and “Dr
"/ R (%)" indicates the GMR ratio. Furthermore, "H
“Ha (A / m)” indicates the magnitude of the magnetic field required to direct the magnetization direction in the free layer 16 to the hard axis, and the smaller this value is, the more ideal. In addition, Table 2 also shows a comparative example in order to evaluate the magnetic characteristics of this example.

A series of magnetic reproducing heads S11 shown in Table 2
~ S14, S11 ~ S13 corresponds to the comparative example,
S14 corresponds to an example of the present embodiment (see FIG. 1). The configurations listed below are mainly the configurations of the laminated body from the seed layer to the fixed layer of the SV structure in the magnetic reproducing head. Of these, only the laminated body of S11 was examined for the above characteristics without performing the annealing treatment. S12-S1
2000 / (4π) × 10 for the laminated body of 4
After fixing the magnetization direction of the pinned layer by performing an annealing treatment at a temperature of 280 ° C. for 5 hours in a lateral magnetic field of ³ (≈1.6 × 10 ⁵ ) A / m, The above characteristics were measured.

S11 is "tantalum layer (7.5 nm thick)"
/ CoFe alloy layer (2.0 nm thickness) / copper layer (3.0 nm
Thickness) / tantalum layer (5.0 nm thickness) ”. Here, the tantalum layer corresponds to the seed layer, and CoF
The e-alloy layer corresponds to the free layer. In S12, the laminated body of S11 is annealed under the above conditions. S13
Is "NiCr alloy layer (5.5 nm thickness) / CoFe alloy layer (2.0 nm thickness) / copper layer (2.2 nm thickness) / NiCr
Alloy layer (5.0 nm thick) ". NiCr
The alloy layer corresponds to the seed layer, and the CoFe alloy layer corresponds to the free layer. S14 is “NiCr alloy layer (5.5 nm
Thickness) / ruthenium layer (0.5 nm thickness) / CoFe alloy layer (2.0 nm thickness) / copper layer (2.0 nm thickness) / NiCr alloy layer (5.0 nm thickness) ”. here,
The NiCr alloy layer corresponds to the seed layer 12, the ruthenium layer corresponds to the buffer layer 14, and the CoFe alloy layer corresponds to the free layer 16.

According to Table 2, the magnetic moment B of S11
Although s was 0.25 nWb, the magnetic moment of S12 was 0.14 nWb. This decrease in magnetic moment is due to the tantalum layer and CoFe
This is because internal diffusion occurred between the alloy layer and the alloy layer.

The magnetic anisotropy of S13 is weak and can be regarded as isotropic in reality. Further, the magnetic field Hha required to direct the magnetization direction of the free layer to the difficult axis is 1591.
It was a large value exceeding 55 A / m.

At S14, the holding force Hc is 350.14A.
/ M and the anisotropic magnetic field Hk is 732.11 A /
Since the coercive force Hc and the anisotropic magnetic field Hk are both low, the magnetic anisotropy is small. Magnetic field Hh
The value of a is 318.31 A / m, which is much smaller than the magnetic field Hha of S13. Therefore, the magnetization direction of the free layer can be changed even with a slight magnetic field.

As described above, the present embodiment S14 is superior to the comparative examples S11 to S13 having no buffer layer in magnetic characteristics, especially in the anisotropy of the free layer, and has a more suitable sensitivity as a magnetic reproducing head. It was confirmed to have.

Subsequently, in the magnetic reproducing head according to the present embodiment, the magnetic characteristics of the fixed layer were mainly investigated. Table 3 shows the experimental results.

[0068]

[Table 3]

"Bs (nWb)" is the magnetic moment,
"Hc (A / m)" is a coercive force, "He (A / m)" is an interlayer coupling magnetic field, "Hk (A / m)" is an anisotropic magnetic field, and "Rs"
(Ω / □) ”is the sheet resistance,“ Dr / r (%) ”is the magnetoresistance change rate (GMR ratio), and“ Dr (Ω / □) ”is the GMR.
The resistance change (that is, the output intensity) based on the effect, the “rotation angle (°)” indicates the rotation angle of the magnetic moment of the fixed layer. The measurement of this rotation angle is performed as follows. That is,
After annealing in a high magnetic field for fixing the magnetization direction of the pinned layer, the relative direction of the magnetic moment in the pinned layer with respect to the entire magnetic reproducing head is examined. Then, after returning the magnetization direction of the free layer to the original state by annealing in a low magnetic field, the direction of the magnetic moment of the fixed layer is measured again to obtain the value of the rotation angle. When this rotation angle is small, it can be said that the reliability of the magnetic reproducing head, especially the fixed layer is high. Table 3
In order to clarify the magnetic characteristics of the fixed layer in the magnetic reproducing head of the present embodiment, the magnetic characteristics of the comparative example are also shown in FIG.

A series of magnetic reproducing heads S2 shown in Table 3
1 to S24, S21 to S23 correspond to the comparative example, and
Reference numeral 24 corresponds to an example of the present embodiment (see FIG. 1).
The configurations listed below are among the magnetic reproducing heads.
The structure is mainly from the seed layer to the protective layer. For the free layer, the same material (CoFe
Alloy) and the same thickness (2.0 nm thickness). Regarding the magnetic reproducing heads of S21 to S24, first, annealing treatment in a high magnetic field (2000 / (4π) × 1
0 ³ A / m, 280 ° C., 5 hours) to fix the magnetization direction of the pinned layer, followed by annealing in a low magnetic field (50 / (4π) × 10 ³ A / m, 290 ° C., Thirty
The magnetization direction of the free layer was restored to the original direction by performing (1).

S21 is "Ta (7.5 nm thickness) / Co
Fe (2.0 nm thickness) / Cu (3.0 nm thickness) / CoF
e (2.0 nm thickness) / MnPt (20 nm thickness) / Ta
(5.0 nm thickness) ", and S22 is" N
iCr (5.5 nm thickness) / CoFe (2.0 nm thickness) /
Cu (2.2 nm thickness) / CoFe (1.5 nm thickness) / M
nPt (15 nm thickness) / NiCr (5.0 nm thickness) ”. Both S21 and S22 are C
The buffer layer is not included below the free layer made of oFe. S23 is "NiCr (5.5 nm thickness) /
Ru (0.5 nm thickness) / CoFe (2.0 nm thickness) / C
u (1.8 nm thickness) / CoFe (2.0 nm thickness) / Mn
Pt (20 nm thickness) / NiCr (2.0 nm thickness) ”. Further, S24 corresponds to FIG. 1 in order from the seed layer 12 to the protective layer 30 "NiCr".
(5.5 nm thickness) / Ru (0.5 nm thickness) / CoFe
(2.0 nm thickness) / Cu (1.8 nm thickness) / CoFe
(1.1 nm thickness) / NiCr (3.5 nm thickness) / CoF
e (0.5 nm thickness) / MnPt (20 nm thickness) / NiC
r (2.0 nm thick) ". Thus, both S23 and S24 have a buffer layer made of ruthenium (Ru) under the free layer. Furthermore, S
24 is “CoFe (1.1 nm thick) / NiCr (3.
5 nm thickness / CoFe (0.5 nm thickness) ”, the fixed layer 20 having a three-layer structure is different from S23.

From the results of Table 3, S21 which is not annealed is extremely low in GM as compared with S22 to S24.
While showing an R ratio (Dr / r), it was found that S23 and S24 provided with a ruthenium buffer layer have both a high GMR ratio and excellent anisotropy.

A tantalum (Ta) layer is provided in S21 under the free layer of CoFe alloy having a thickness of 2.0 nm.
In No. 22, a NiCr alloy layer is provided.
An iCr alloy layer / ruthenium (Ru) layer was provided. In such a structure, the output intensity Dr was 0.96 for S21, 2.44 for S22, and 2.91 for S23, as shown in Table 3. From this, it was found that the structure having the free layer on the tantalum layer had too small output intensity (Dr) and could not be applied to the reproducing head corresponding to the ultra high recording density. Further, it was confirmed that the magnetic reproducing head provided with the buffer layer can exhibit higher output strength. Therefore, the provision of the buffer layer is expected to improve the sensitivity of the magnetic sensor.

Regarding the rotation angle, all of S21 to S23 showed high values, and it was found that the rotation of the magnetization direction in the pinned layer was large. As a result, it is estimated that the output intensity Dr is reduced by about 10% as compared with the case where there is no rotation in the magnetization direction. On the other hand, in the present embodiment S24 in which the ruthenium buffer layer 14 is disposed below the free layer and the fixed layer 20 having a three-layer laminated structure is provided, the rotation angle is less than 1.5 °, which is an extremely small value. Is. Therefore, it was found that the output intensity Dr did not decrease and the fixed layer had high reliability.

As described above, according to the magnetic reproducing head of the present embodiment, since the free layer is excellent in anisotropy and the fixed layer is highly reliable, it exhibits high sensitivity to a signal magnetic field and magnetic recording. It was found that it can cope with high density of the medium.

Subsequently, the following two experiments were conducted to further prove the reliability of the fixed layer.

First, S21, S23, and S2 of Table 3
A magnetic field was applied to the spin valve structure shown in FIG. 4 to examine the magnetic field dependence of the GMR ratio (%). The magnetic field scanning method was as follows. First, the magnetic field is 6000 / (4π) × 10 ³ (≈4.8 × 10 ⁵ ) A / in the magnetization direction of the pinned layer.
After applying to m, the magnetic field is returned to zero. Then, 60 in the direction opposite to the magnetization direction of the pinned layer.
A magnetic field of 00 / (4π) × 10 ³ (≈4.8 × 10 ⁵ ) A / m was applied, and the magnetization direction of the pinned layer was set to 6 again.
000 / (4π) × 10 ³ (≈4.8 × 10 ⁵ ) A / m
The magnetic field of is applied. These results are shown as a hysteresis curve in FIGS. 2 corresponds to S21, FIG. 3 corresponds to S23, and FIG. 4 corresponds to S24. 2 to 4
Then, the horizontal axis represents the applied magnetic field (× 10 ⁵ A / m),
The vertical axis represents the GMR ratio (Dr / r (%)).

S21 using a tantalum layer under the free layer
Then, as shown in FIG.
/ (4π) × 10 ³ (≈0.88 × 10 ⁵ ) A / m, H
c is 400 / (4π) × 10 ³ (≈0.32 × 10 ⁵ )
It was A / m. Furthermore, the GMR ratio (Dr / r) is 5.6.
%, The output intensity (Dr) was 0.96 Ω / □. The "pinning magnetic field" means the average value of two positive magnetic field values when the GMR ratio (Dr / r) becomes half of its maximum value, and "Hc" is the two positive magnetic field values. Is the half-value of the difference.

Similarly, in S23 having a ruthenium buffer layer and a single fixed layer, the pinning magnetic field was 950 / (4π) × 10 ³ (≈0.76) as shown in FIG.
× 10 ⁵ ) A / m, Hc is 400 / (4π) × 10
³ (≈ 0.32 × 10 ⁵ A / m. Further GMR
The ratio (Dr / r) is 13.0% and the output intensity (Dr) is 2.
It was 90Ω / □.

Example S2 corresponding to the configuration of the present embodiment
4, the pinning magnetic field is 110, as shown in FIG.
0 / (4π) × 10 ³ (≈0.88 × 10 ⁵ ) A / m,
Hc is 100 / (4π) × 10 ³ (≈0.08 × 1)
0 ⁵ ) It was less than A / m. Further, the GMR ratio Dr / r was 10.7% and the output intensity Dr was 2.55 Ω / □.

As described above, by comparing FIGS. 2 to 4, it was found that in this Example S24, the Hc of the fixed layer was very small, and the opening in the hysteresis curve was hardly seen. This experiment confirmed that the fixed layer having the configuration of the present embodiment has high reliability.

Then, S21, S23, and S in Table 3 are
S having a structure similar to the spin valve structure shown in FIG.
31, S33, and S34 were prepared and the following experiments were conducted. First, 7000 / (4π) × 10 ³ (≈5.6 ×
10 ⁵ ) After applying the external magnetic field of A / m, the magnetization direction of the pinned layer is once determined to be a predetermined direction, and then, to the opposite direction.
Newly 7000 / (4π) × 10 ³ (≈5.6 × 1)
A magnetic field of 0 ⁵ ) A / m was applied. Here, the GMR ratio (Dr
/ R) was measured to see if the magnetization direction changed. The result is shown in FIG. The vertical axis of FIG. 5 is Dr / r
(%), The horizontal axis represents the applied magnetic field (× 10 ⁵ A / m)
Represents Here, the decrease of Dr / r means rotation of the magnetization direction of the pinned layer. It was found that in S31 in which the tantalum layer was provided below the free layer, Dr / r decreased very gradually as the magnetic field increased. In S33 including the buffer layer made of ruthenium and the single pinned layer, the rotation of the magnetization of the pinned layer is 1000 / (4π) × 10 ³ (≈).
It was found that it appeared remarkably from around 0.80 × 10 ⁵ ) A / m, and then the rotation accelerated. On the other hand, in S34 corresponding to the configuration of the present embodiment, it is confirmed that Dr / r hardly changes without the influence of the external magnetic field (that is, the magnetization direction does not rotate), and exhibits good reliability. Was done.

Fontana Jr. described in the [Prior Art] section.
"CoFe alloy / ruthenium (Ru) / CoFe alloy /" shown in U.S. Pat. No. 5,701,223.
A spin valve structure including an antiferromagnetically coupled pinned layer (so-called synthetic antiferromagnetic pinned layer) having a structure called “MnPt alloy” is known for its extremely high pinned layer reliability. On the other hand, the fixed layer 20 of the present embodiment
It has been found that the magnetic reproducing head having the magnetic field of not only has the same degree of reliability as the magnetic reproducing head having the synthetic antiferromagnetic pinned layer, but also has many very useful properties as described above.

As described above, in the magnetic reproducing head according to the present embodiment, the seed layer 12, the buffer layer 14 made of a material such as ruthenium which increases the magnetoresistive effect, and the CoFe alloy are provided on the substrate 10. A free layer 16 made of a ferromagnetic material whose magnetization direction freely rotates, a non-magnetic layer 18 made of a non-magnetic material such as copper, a pinned layer 20 having a laminated structure, a pinning layer 28, and a protective layer 30. After sequentially forming and, the whole is annealed in the first magnetic field to fix the magnetization direction of the pinned layer 20, and
By annealing the entire structure in a second magnetic field lower than the first magnetic field, the magnetization direction of the free layer 16 is returned to the initial state, so that the magnetoresistance change rate is increased and the heat of the free layer 16 is increased. Stability against.
This provides soft magnetism and unidirectionality of the magnetization, which facilitates control of the bias point, improves sensitivity to magnetic signals, and enables detection of weaker magnetic signals from high-density media than before. become.

Further, since the fixed layer 20 has a laminated structure, the inter-layer coupling magnetic field (He) of each layer becomes small, and the static magnetic field (magnetic field that does not change with time) generated by the fixed layer 20 depends on the magnetic field of the sensor current. Since it is compensated, it was confirmed that the optimum bias level can be secured.

At present, 35 Gbits / inch ² (≈
In order to read information from a high-density magnetic recording medium exceeding 5.43 Gbits / cm ² ), for example, a magnetic reproducing head having a gap of 0.1 μm from the upper shield to the lower shield and 0.57 μm Has been attempted to realize the magnetic reproduction track width (MRW).
Ratio of maximum and minimum voltage to this minute track width (V
Sensor sensitivity measured as pp / MRW) is 11 mV
It is necessary to develop a magnetic reproducing head having a thickness of / μm. The magnetic reproducing head of the present embodiment can sufficiently cope with such high recording density.

Although the present invention has been described with reference to the embodiments and some examples, the present invention is not limited to the above-described embodiments and examples, and various modifications can be made.
That is, the details of the structure, material, size, and manufacturing method of the magnetic reproducing head described in the above-described embodiments and examples are not necessarily limited to this, and the buffer layer is formed under the thin free layer, and By making the fixed layer a laminated structure, the bias point can be easily controlled, a high GMR ratio (Dr / r) can be maintained, and sufficient soft magnetic properties and reliability of the pinned layer can be obtained freely. It can be transformed.

[0088]

As described above, according to the method of manufacturing the magnetic reproducing head according to any one of claims 1 to 16, the seed layer on the substrate and the material for increasing the magnetoresistive effect. Made of a ferromagnetic material, a free layer made of a ferromagnetic material and having a freely magnetizable direction, a first nonmagnetic spacer layer made of a nonmagnetic material, a pinned layer having a laminated structure, a pinning layer, and a protection layer. Layers are formed in order and the whole is first
After fixing the magnetization direction of the pinned layer by annealing in the magnetic field of, the whole is annealed in the second magnetic field lower than the first magnetic field to return the magnetization direction of the free layer to the initial state. Since it has excellent controllability of bias point, high GMR ratio (Dr / r) and good soft magnetism, it has thermal stability and high output performance, and is a magnetic reproducing head compatible with ultra high density recording. Can be formed.

Any one of claims 17 to 32
According to the magnetic reproducing head of the item, the substrate, the seed layer, the buffer layer made of a material that increases the magnetoresistive effect,
A free layer made of a ferromagnetic material, the magnetization direction of which freely rotates, a first non-magnetic spacer layer made of a non-magnetic material,
A pinned layer having a laminated structure in which the magnetization direction is pinned by annealing in a first magnetic field, and a pinning layer;
Since it is provided with a protective layer, it has excellent bias point controllability, high GMR ratio (Dr / r) and good soft magnetism, and also has thermal stability and high output performance, and ultra high density recording. Can correspond to.

According to the magnetic reproducing head manufacturing method of the third aspect or the magnetic reproducing head of the nineteenth aspect, conduction electrons are more effectively totally reflected between the buffer layer and the free layer. Therefore, it is more suitable for reproduction of ultra-high density recording.

Further, according to the method of manufacturing a magnetic reproducing head described in any one of claims 7 to 11 or the magnetic reproducing head described in any one of claims 23 to 27, Since the fixed layer having the ferromagnetic coupling structure in which the first ferromagnetic layer, the second non-magnetic spacer layer, and the second ferromagnetic layer are laminated in this order is provided, Increased stability and higher output performance.

Furthermore, according to the method of manufacturing a magnetic reproducing head of the twelfth aspect or the magnetic reproducing head of the twenty-eighth aspect, the fixed action layer made of a manganese platinum alloy or a manganese platinum palladium alloy is formed on the ferromagnetic layer. Are laminated, a higher blocking temperature, a higher exchange bias magnetic field and better corrosion resistance can be obtained.

[Brief description of drawings]

FIG. 1 is a cross-sectional view illustrating a cross-sectional configuration of a main part of a magnetic reproducing head according to an embodiment of the present invention.

FIG. 2 is a diagram showing the magnetic field dependence of Dr / r in Comparative Example S21.

FIG. 3 is a diagram showing the magnetic field dependence of Dr / r in Comparative Example S23.

FIG. 4 shows Dr in Example S24 according to the present embodiment.
It is a figure which shows the magnetic field dependence of / r.

FIG. 5 is a diagram showing the reliability of the fixed layer in Example S34 and Comparative Examples S31 and S33 according to the present embodiment.

[Explanation of symbols]

10 ... Substrate, 12 ... Seed layer, 14 ... Buffer layer, 16 ... Free layer, 18 ... First non-magnetic spacer layer, 20 ... Pinned layer, 22 ... First ferromagnetic layer, 24 ... Second non-magnetic layer Magnetic spacer layer, 26 ... Second ferromagnetic layer, 28 ... Pinning layer, 30
... Protective layer, 32 ... Top spin valve structure.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Min Li             United States California             94538 Fremont Leslie Strey             To 39663 Apartment 408 (72) Inventor Boiled children             United States California             95130 San Jose Levine Drive             2433 F-term (reference) 5D034 BA02 BA03 BA04 BA05 CA04                       CA08 DA07                 5E049 AA01 AA04 AA07 AA09 AC00                       AC05 BA12 CB02 DB12

Claims (32)

[Claims] 1. A method of manufacturing a magnetic reproducing head having a spin valve structure corresponding to an ultrahigh recording density, comprising a first step of forming a seed layer on a substrate, and a magnetoresistive film on the seed layer. A second step of forming a buffer layer using a material that increases the effect, and a third step of forming a free layer on the buffer layer using a ferromagnetic material in which the magnetization direction freely rotates, A fourth step of forming a first non-magnetic spacer layer on the free layer using a non-magnetic material, and a fifth step of forming a fixed layer having a laminated structure on the first non-magnetic spacer layer. And a sixth step of forming a fixed action layer on the fixed layer, a seventh step of forming a protective layer on the fixed action layer, and an annealing treatment of the whole in a first magnetic field. Is applied to fix the magnetization direction of the pinned layer. And a ninth step of returning the magnetization direction of the free layer to the initial state by performing an annealing process on the whole in a second magnetic field lower than the first magnetic field. Reproduction head manufacturing method. 2. The nickel-chromium (NiCr) alloy and the nickel-iron-chromium (NiFe) in the first step.
2. The method of manufacturing a magnetic reproducing head according to claim 1, wherein the seed layer is formed using at least one of Cr) alloys so as to have a thickness of 4 nm or more and 7 nm or less. 3. The ruthenium (Ru), rhodium (Rh) and iridium (Ir) in the second step.
0.3n with at least one of the group consisting of
The method of manufacturing a magnetic reproducing head according to claim 1, wherein the buffer layer is formed so as to have a thickness of m or more and 2.5 nm or less. 4. In the third step, a cobalt iron (CoFe) alloy is used, and the thickness is 1.0 nm or more and 6.0 nm or more.
The method of manufacturing a magnetic reproducing head according to claim 1, wherein the free layer is formed to have the following thickness. 5. In the third step, a cobalt iron boron (CoFeB) alloy is used and 1.0 nm or more and 6.
The method of manufacturing a magnetic reproducing head according to claim 1, wherein the free layer is formed so as to have a thickness of 0 nm or less. 6. The fourth non-magnetic spacer layer is formed in the fourth step by using copper (Cu) so as to have a thickness of 1.8 nm or more and 3.0 nm or less. The method for manufacturing the magnetic reproducing head according to claim 1. 7. A ferromagnetic coupling structure is obtained by stacking a first ferromagnetic layer, a second non-magnetic spacer layer, and a second ferromagnetic layer in this order in the fifth step. The method of manufacturing a magnetic reproducing head according to claim 1, wherein the fixed layer is formed as described above. 8. A cobalt iron alloy is used to form the first ferromagnetic layer so as to have a thickness of 0.8 nm to 2.0 nm, and a nickel chromium alloy is used to form 0.2 nm to 0.1 nm. 5n
The second non-magnetic spacer layer is formed so as to have a thickness of m or less, and the second ferromagnetic layer is formed using a cobalt iron alloy so as to have a thickness of 0.4 nm or more and 1.0 nm or less. The method of manufacturing a magnetic reproducing head according to claim 7, wherein 9. The method of manufacturing a magnetic reproducing head according to claim 8, wherein the first and second ferromagnetic layers are formed so that the thickness ratio is 2: 1. 10. Cobalt (Co), a cobalt iron alloy,
Cobalt iron boron alloy and nickel iron alloy (NiF
e) using any one of the group consisting of
The first ferromagnetic layer is formed to have a thickness of not less than 2.0 nm and not more than 2.0 nm, and at least one of a nickel-chromium alloy and a nickel-iron-chromium alloy is used, and not less than 0.2 nm and not more than 0.5 nm
The second non-magnetic spacer layer is formed to have the following thickness, and 0.4 nm or more is formed using at least one selected from the group consisting of cobalt, cobalt iron alloys, cobalt iron boron alloys, and nickel iron alloys. 8. The method of manufacturing a magnetic reproducing head according to claim 7, wherein the second ferromagnetic layer is formed so as to have a thickness of 1.0 nm or less. 11. The method of manufacturing a magnetic reproducing head according to claim 10, wherein the first and second ferromagnetic layers are formed so that the thickness ratio is 2: 1. 12. The manganese platinum (MnPt) alloy and the manganese platinum palladium (M) in the sixth step.
nPtPd) alloy using at least one of
The method of manufacturing a magnetic reproducing head according to claim 1, wherein the fixing layer is formed so as to have a thickness of 0.0 nm or more and 30.0 nm or less. 13. In the sixth step, an iridium manganese (IrMn) alloy is used, and the thickness is 5.0 nm or more.
The method of manufacturing a magnetic reproducing head according to claim 1, wherein the fixing action layer is formed so as to have a thickness of 5.0 nm or less. 14. The nickel-chromium alloy, the nickel-iron-chromium alloy, and the tantalum (T) in the seventh step.
1. using at least one of the group consisting of a),
The method of manufacturing a magnetic reproducing head according to claim 1, wherein the protective layer is formed so as to have a thickness of 0 nm or more and 5.0 nm or less. 15. In the eighth step, 2000 /
5 in a lateral magnetic field of (4π) × 10 ³ A / m
The method of manufacturing a magnetic reproducing head according to claim 1, wherein the annealing treatment is performed at a temperature of 280 ° C. for a long time. 16. In the ninth step, 50 / (4
The method of manufacturing a magnetic reproducing head according to claim 1, wherein the annealing treatment is performed at a temperature of 290 ° C. for 30 minutes in a longitudinal magnetic field of π) × 10 ³ A / m. 17. A spin-valve type magnetic reproducing head compatible with ultra-high recording density, comprising a substrate, a seed layer formed on the substrate, and a magnetoresistive effect formed on the seed layer. A buffer layer made of a material, a free layer formed on the buffer layer by a ferromagnetic material and having a freely rotatable magnetization direction, and a first nonmagnetic spacer made of a nonmagnetic material formed on the free layer. Layer, a pinned layer formed on the first non-magnetic spacer layer and having a laminated structure in which the magnetization direction is pinned by an annealing treatment in a first magnetic field, and a pinning action formed on the pinned layer. A magnetic reproducing head comprising a layer and a protective layer formed on the fixed action layer. 18. The seed layer is nickel chrome (N
iCr) alloy or nickel iron chromium (NiFeCr)
Made of any of alloys and having a thickness of 4.0 nm or more and 7.0
18. The magnetic reproducing head according to claim 17, which has a thickness of nm or less. 19. The buffer layer is ruthenium (Ru),
18. The magnetic reproducing head according to claim 17, wherein the magnetic reproducing head is made of any one of the group consisting of rhodium (Rh) and iridium (Ir) and has a thickness of 0.3 nm or more and 2.5 nm or less. 20. The free layer is cobalt iron (CoF).
The magnetic reproducing head according to claim 17, wherein the magnetic reproducing head is made of an alloy e) and has a thickness of 1.0 nm or more and 6.0 nm or less. 21. The magnetic reproducing head according to claim 17, wherein the free layer is made of a cobalt iron boron (CoFeB) alloy and has a thickness of 1.0 nm or more and 6.0 nm or less. 22. The magnetic reproducing head according to claim 17, wherein the first non-magnetic spacer layer is made of copper (Cu) and has a thickness of 1.8 nm or more and 3.0 nm or less. 23. The fixed layer includes a first ferromagnetic layer,
18. The magnetic reproducing head according to claim 17, wherein the magnetic reproducing head has a ferromagnetic coupling structure in which a second non-magnetic spacer layer and a second ferromagnetic layer are sequentially stacked. 24. The first ferromagnetic layer is made of a cobalt iron alloy and has a thickness of 0.8 nm or more and 2.0 nm or less, and the second non-magnetic spacer layer is made of a nickel chromium alloy. The thickness of 0.2 nm or more and 0.5 nm or less, and the second ferromagnetic layer is made of a cobalt iron alloy and has a thickness of 0.4 nm or more and 1.0 nm or less. The magnetic reproducing head described. 25. The magnetic reproducing head of claim 24, wherein the first and second ferromagnetic layers have a thickness ratio of 2: 1. 26. The first ferromagnetic layer comprises cobalt (C
o), a cobalt iron alloy, a cobalt iron boron alloy, and a nickel iron (NiFe) alloy, and at least one kind thereof, and has a thickness of 0.8 nm or more and 2.0 nm or less, and the second nonmagnetic material. The spacer layer includes at least one of a nickel-chromium alloy and a nickel-iron-chromium alloy and has a thickness of 0.2 nm or more and 0.5 nm or less, and the second ferromagnetic layer is cobalt, a cobalt iron alloy, 24. The magnetic reproducing head according to claim 23, comprising at least one of a cobalt iron boron alloy and a nickel iron alloy, and having a thickness of 0.4 nm or more and 1.0 nm or less. 27. The magnetic reproducing head according to claim 26, wherein the thickness of the first and second ferromagnetic layers is 2: 1. 28. The manganese platinum (M)
nPt) alloy or manganese platinum palladium (MnPt)
Pd) alloy, 10.0 nm or more and 30.0
18. The magnetic reproducing head according to claim 17, which has a thickness of nm or less. 29. The immobilization layer is made of an iridium manganese (IrMn) alloy and has a thickness of 5.0 nm or more.
18. The magnetic reproducing head according to claim 17, having a thickness of 5.0 nm or less. 30. The protective layer is a nickel chromium alloy,
It is composed of at least one member selected from the group consisting of a nickel-iron-chromium alloy and tantalum (Ta).
18. The magnetic reproducing head according to claim 17, having a thickness of not less than m and not more than 5.0 nm. 31. The fixed layer is 2000 / (4π)
In a lateral magnetic field of × 10 ³ A / m for 5 hours, 2
The magnetic reproducing head according to claim 17, wherein the magnetic reproducing head has been annealed at a temperature of 80 ° C. 32. The free layer is 50 / (4π) × 1
29 in a longitudinal magnetic field of 0 ³ A / m for 30 minutes
The magnetic reproducing head according to claim 17, wherein the magnetic reproducing head is annealed at a temperature of 0 ° C.