JP2002123913A - Magneto-resistive effect sensor, thin film magnetic head furnished with this sensor, and manufacturing method of these sensor and head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an MR sensor coped with the increase of recording density by making the resistance change ΔRs to be large, a thin film magnetic head furnished with this MR sensor, a manufacturing method of this MR sensor and a manufacturing method of this thin film magnetic head. SOLUTION: This MR sensor is provided with an antiferromagetic layer 134, a 1st ferromagnetic layer (pinned layer) 133 laminated in the adjacent relation to the antiferromagnetic layer, a nonmagnetic layer 132 laminated in the adjacent relation to the 1st ferromagnetic layer and a 2nd ferromagnetic layer (free layer) 131 laminated in the adjacent relation to the nonmagnetic layer, then this sensor makes use of the bias magnetic field formed by the exchanging combination between the antiferromagnetic layer and the 1st ferromagnetic layer. The 1st ferromagnetic layer is constituted of antiferromagnetically coupled 1st and 2nd ferromagnetic films 133a, 133b each other by being separated with an antiferromagnetic combination film 133c, and a specific metal is diffused to at least a part of the 1st ferromagnetic film 133a adjacent to the antiferromagnetic layer 134.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetoresistance (MR) sensor utilizing a giant magnetoresistance effect (GMR) or a tunnel magnetoresistance effect (TMR), and is provided with this MR sensor, for example, a hard disk drive (HDD). The present invention relates to a thin-film magnetic head used for a magnetic recording / reproducing device such as a floppy (registered trademark) disk device (FDD), a method of manufacturing this MR sensor, and a method of manufacturing a thin-film magnetic head.

[0002]

2. Description of the Related Art In recent years, a magnetic head with high sensitivity and high output has been demanded with the increase in the density of HDDs. To meet such demands, a spin valve effect, which is one of the sensors exhibiting GMR, has been demanded. There has been proposed a thin film magnetic head provided with an MR sensor utilizing the same. Spin valve (S
V) The MR sensor has a sandwich structure in which two ferromagnetic layers are magnetically separated by a non-magnetic metal layer, and an exchange bias magnetic field generated at the interface by stacking an antiferromagnetic layer on one of the ferromagnetic layers. Is applied to this one ferromagnetic layer (pinned layer). Since the pinned layer that receives the exchange bias magnetic field and the other ferromagnetic layer that does not receive the exchange bias magnetic field (free layer) have different magnetic fields for magnetization reversal, the magnetization directions of these two ferromagnetic layers sandwiching the nonmagnetic metal layer are parallel. , Antiparallel, and thereby the electrical resistivity greatly changes, so that GMR can be obtained.

The output characteristics and the like of the SVMR sensor are determined by the angle between the magnetizations of the two ferromagnetic layers (pinned layer and free layer) sandwiching the nonmagnetic metal layer. The magnetization direction of the free layer easily points in the direction of the leakage magnetic field from the magnetic recording medium. On the other hand, the magnetization direction of the pinned layer is one direction (pinning direction, pinned direction) due to exchange coupling with the antiferromagnetic layer.
Is controlled.

Japanese Patent Application Laid-Open No. Hei 7-169006 discloses that the pinned layer of such an SVMR sensor is composed of a multilayer film composed of two ferromagnetic films separated by an antiferromagnetic coupling film, thereby stabilizing the pinned layer. An SVMR sensor (synthetic pin SVMR sensor) has been described which has enhanced characteristics and facilitates control of the vertical asymmetry of the reproduced waveform.

[0005]

An object of the present invention is to improve the MR ratio and the resistance change ΔRs of an MR sensor having such a synthetic pin structure. That is,
SUMMARY OF THE INVENTION An object of the present invention is to provide an MR sensor capable of increasing the recording density by increasing the resistance change ΔRs, a thin-film magnetic head having the MR sensor, a method of manufacturing the MR sensor, and a method of manufacturing the thin-film magnetic head. Is to do.

[0006]

The present invention provides an antiferromagnetic layer, a first ferromagnetic layer (pinned layer) laminated adjacent to the antiferromagnetic layer, and a first ferromagnetic layer. An antiferromagnetic layer and a first ferromagnetic layer, comprising a nonmagnetic layer stacked adjacent to the second ferromagnetic layer (free layer) stacked adjacent to the nonmagnetic layer; The present invention relates to an MR sensor using a bias magnetic field by exchange coupling with a magnetic field. In particular, according to the present invention,
The first ferromagnetic layer is composed of first and second ferromagnetic films separated by an antiferromagnetic coupling film and antiferromagnetically coupled to each other, and a first ferromagnetic layer adjacent to the antiferromagnetic layer. Provided are an MR sensor in which a predetermined metal is diffused into at least a part of a magnetic film, and a thin-film magnetic head including the MR sensor.

As described above, since the predetermined metal is diffused into a part of the pinned layer, the sheet resistance Rs of the entire MR sensor is increased.
Becomes larger. Generally, the resistance change ΔRs of the MR sensor
Is ΔΔ, where MR is the MR change rate and Rs is the sheet resistance.
Rs [Ω] = MR [%] × Rs [Ω] Therefore, by increasing the sheet resistance Rs, a high Δ
Rs can be obtained. As a result, the size of the MR sensor can be reduced, and an MR sensor and a thin-film magnetic head corresponding to high recording density can be provided.

It is preferable that an interdiffusion layer of a predetermined metal in which a metal constituting the first ferromagnetic film is diffused is formed in the middle of the first ferromagnetic film.

It is also preferred that the interdiffusion layer has a thickness of 0.05 to 0.4 nm.

The predetermined metal is Al, Si, Ti, V, C
r, Mn, Ga, Ge, Y, Zr, Nb, Mo, Ru,
Rh, Pd, In, Sn, Hf, Ta, W, Re, O
The metal is preferably a metal containing at least one selected from the group consisting of s, Ir, and Pt.

According to the present invention, the first and second ferromagnetic layers (free layers), the non-magnetic layer, and the first and second ferromagnetic layers separated by an antiferromagnetic coupling film and antiferromagnetically coupled to each other are further provided. A method of manufacturing an MR sensor formed by sequentially stacking a first ferromagnetic layer (pinned layer) made of a ferromagnetic film and an antiferromagnetic layer, or using an underlayer, an antiferromagnetic layer, and an antiferromagnetic coupling film A first ferromagnetic layer (pinned layer), a nonmagnetic layer, and a second ferromagnetic layer (free layer) composed of the first and second ferromagnetic films separated and antiferromagnetically coupled to each other are sequentially formed. The present invention relates to a method for manufacturing a laminated MR sensor. In particular, according to the present invention, an interdiffusion layer of a predetermined metal is formed in the middle of the first ferromagnetic film adjacent to the antiferromagnetic layer, and the predetermined metal is diffused into at least a part of the first ferromagnetic film. The present invention provides a method of manufacturing an MR sensor to be used, and a method of manufacturing a thin film magnetic head in which an MR sensor used for reproducing magnetic information is formed by the above-described method.

It is preferable that the interdiffusion layer is formed to a thickness of 0.05 to 0.4 nm.

It is also preferable that a protective layer is laminated on the antiferromagnetic layer or the second ferromagnetic layer (free layer).

The predetermined metal is Al, Si, Ti, V, C
r, Mn, Ga, Ge, Y, Zr, Nb, Mo, Ru,
Rh, Pd, In, Sn, Hf, Ta, W, Re, O
The metal may include at least one selected from the group consisting of s, Ir, and Pt.

[0015]

FIG. 1 is a sectional view schematically showing the structure of a main part of a thin film magnetic head according to an embodiment of the present invention. FIG. 2 is a diagram showing the layer structure of an SVMR laminated structure. FIG. 4 is a cross-sectional view showing the air bearing surface (ABS) direction. The thin-film magnetic head according to the present embodiment is a composite thin-film magnetic head including a read head formed of an MR sensor and a write head formed of an inductive magnetic transducer.

In FIG. 1, reference numeral 10 denotes a substrate constituting a main part of the slider, 11 denotes a lower shield layer formed on a substrate 10 via a base film (not shown), and 12 denotes a lower magnetic layer of a write head. Upper shield layer that also serves as 13
Is an SVMR laminated structure formed so as to extend along the ABS 10a between the lower shield layer 11 and the upper shield layer 12 via the insulating layers 14 and 15, 16 is an upper magnetic layer, and 17 is an organic resin. , A coil conductive layer surrounded by an insulating layer 18, a gap layer 19, and a protective layer 20.

The tip portions of the lower magnetic layer 12 and the upper magnetic layer 16 form pole portions 12a and 16a opposed to each other with a very small gap layer 19 therebetween.
Writing is performed in 2a and 16a. A back gap portion of the lower magnetic layer 12 and the upper magnetic layer 16 constituting the yoke portion opposite to the pole portions 12a and 16a is a back gap portion and is coupled to each other so as to complete a magnetic circuit.
The coil conductive layer 17 is formed on the insulating layer 18 so as to spiral around the joint of the yoke.

As shown in FIG. 2, the SVMR laminated structure 1
Reference numeral 3 denotes an underlayer 130 and a second ferromagnetic layer (free layer) 1
31, a nonmagnetic conductive layer 132, a first ferromagnetic layer (pinned layer) 133, an antiferromagnetic layer 134, and a protective layer 135 are sequentially stacked.

The pinned layer 133 is formed of the first ferromagnetic film 133
a, the second ferromagnetic film 133b, and the first and second ferromagnetic films 133b.
And an antiferromagnetic coupling film 133c that separates and ferromagnetically couples the ferromagnetic films 133a and 133b.

In this embodiment, in particular, the antiferromagnetic layer 134
The interdiffusion layer 136 is inserted in the middle of the first ferromagnetic film 133a adjacent to. However, after annealing,
The metal component of the interdiffusion layer 136 is diffused in the first ferromagnetic film 133a of the pinned layer 133, and the metal component of the first ferromagnetic film 133a is diffused in the interdiffusion layer 136. I have.

Specifically, in the present embodiment, the underlayer 130 is, for example, a NiCr film or a Ta film having a thickness of about 3 nm. The free layer 131 includes, for example, a NiFe film having a thickness of about 2 nm and a CoFe film having a thickness of about 1 nm.
It has a two-layer structure with a film. In addition to such a two-layer structure, a single-layer structure or a multilayer structure of two or more layers can be employed. Note that a Co film may be used instead of the CoFe film. The nonmagnetic conductive layer 132 has, for example, a thickness of about 1.8.
It is constituted by a Cu film of about 2.5 nm.

The configuration of the pinned layer 133 will be described later in detail. The pinned layer 133 is exchange-coupled to the antiferromagnetic layer 134, and is fixedly magnetized in one direction by the exchange coupling.

The antiferromagnetic layer 134 has, for example, a thickness of about 1
It is composed of a 2 nm PtMn film or the like. The antiferromagnetic layer 134 is made of NiMn, RuRh, Mn or I
An rMn film may be used. Further, the antiferromagnetic layer 134
May contain at least one selected from the group consisting of Ru, Rh, Pd, Au, Ag, Fe and Cr. The protective layer 135 is made of, for example, Ta having a thickness of about 2 nm.
A membrane can be used.

The pinned layer 133 is formed of a CoFe film having a thickness of about 2.5 nm from the nonmagnetic conductive layer 132 side.
A ferromagnetic film 133b, an antiferromagnetic coupling film 133c made of a Ru film having a thickness of about 0.8 nm,
6 and a first ferromagnetic film 133a of a CoFe film having a thickness of about 1.4 nm.

As the interdiffusion layer 136, for example, a Ta film having a thickness of 0.05 to 0.4 nm can be used. Note that, as the interdiffusion layer 136, Al, Si, T
i, V, Cr, Mn, Ga, Ge, Y, Zr, Nb, M
o, Ru, Rh, Pd, In, Sn, Hf, Ta, W,
A metal film containing at least one selected from the group consisting of Re, Os, Ir, and Pt is used. However, the metal component of the first ferromagnetic film 133a is diffused into the interdiffusion layer 136 after annealing. Conversely, the interdiffusion layer 136 is provided in the first ferromagnetic film 133a after annealing.
Metal components are diffused.

Although not shown in FIG. 2, magnetic domain control layers for applying a vertical magnetic bias to the free layer 131 are provided on both sides of the spin valve MR multilayer structure. The magnetic domain control layer may be a permanent magnet layer or an antiferromagnetic layer, and exchange coupling may occur between the antiferromagnetic layer and the free layer 131. Further, a lead conductor layer is laminated on the magnetic domain control layer. These lead conductor layers are provided for passing a sense current to the nonmagnetic conductive layer 132 of the spin valve MR multilayer structure.

Next, in order to manufacture the SVMR laminated structure 13 in this embodiment, first, as shown in FIG. 2, a base layer 130 (NiCr, 3 nm) and a free layer 131 (NiFe, 2 nm) are formed on a substrate. , And CoFe, 1 nm)
, A nonmagnetic conductive layer 132 (Cu, 1.9 nm), and a second ferromagnetic film 133 b (CoFe, 2n) of the pinned layer 133.
m) and the antiferromagnetic coupling film 133 c of the pinned layer 133 (R
u, 0.8 nm), a part (CoFe, 0.7 nm) of the first ferromagnetic film 133a of the pinned layer 133, the mutual diffusion layer 136 (Ta, 0.05 to 0.4 nm), and the first Of the remaining ferromagnetic film 133a (CoFe, 0.7 nm)
And an antiferromagnetic layer 134 (PtMn, 12 nm) and a protective layer 135 (Ta, 2 nm) are sequentially stacked.

Next, annealing is performed at a temperature of 270 ° C. for 5 hours in a magnetic field of 1000 mT (10 kG). Due to this annealing, the metal component of the first ferromagnetic film 133a diffuses into the interdiffusion layer 136,
In the ferromagnetic film 133a, the metal component of the mutual diffusion layer 136 is diffused.

The other steps for forming the composite type thin film magnetic head are the same as those in the prior art, and the description is omitted.

With respect to the thus obtained SVMR sensor, the MR resistance change ΔRs, MR change rate MR, and sheet resistance Rs when the thickness of the Ta film as the interdiffusion layer 136 is changed are shown in FIGS. This is shown in FIG. However, the measurement magnetic field is 72000 A / m (900 Oe).

As can be seen from these figures, by providing the interdiffusion layer 136, when the film
The rate of change slightly decreases (however, it has a value of 12% or more up to a film thickness of about 0.4 nm). However, since the metal component of the mutual diffusion layer 136 diffuses into the first ferromagnetic layer 133a of the pinned layer 133 by providing the mutual diffusion layer 136, the sheet resistance Rs increases, so that the resistance change ΔRs increases. , The thickness of the Ta film is 0.05 to
The value substantially exceeds 2.1Ω in the range of 0.4 nm.

Table 1 below shows the results obtained by preparing various samples and measuring ΔRs for various SVMR sensors having the laminated structure of the present embodiment but having different materials for the interdiffusion layer.

For each sample, AlTiC with an alumina film was used as a substrate, and a Ta (3 nm) / N
iFe (2 nm) / CoFe (1 nm) / Cu (2.5
nm) / a pinned layer having a synthetic pin structure with an interdiffusion layer inserted / PtMn (12 nm) / Ta (2n
m) are sequentially laminated to form a film, and 1200 mT (12 kG)
Annealing at a temperature of 270 ° C. for 5 hours in the magnetic field of FIG. The measurement magnetic field was 72000 A / m (90
0 Oe).

[0034]

[Table 1]

According to Table 1, as the mutual diffusion layer 136, A
1, Si, Ti, V, Cr, Mn, Ga, Ge, Y, Z
r, Nb, Mo, Ru, Rh, Pd, In, Sn, H
When f, Ta, W, Pt, Re, Os, Ir, TaCo or TaNi are used, it can be seen that the resistance change ΔRs is larger in each case than in the comparative example having no interdiffusion layer.

In the embodiment described above, the mutual diffusion layer 136 is inserted in the center of the pinned layer 133 in the thickness direction of the first ferromagnetic film 133a.
6 may be at any position in the middle of the first ferromagnetic film 133a.

Table 2 below shows various SVMs in which the positions where the interdiffusion layers are inserted differ in the thickness direction of the first ferromagnetic film 133a.
For the R sensor, various samples were created and the results of measuring ΔRs are shown.

For each sample, AlTiC with an alumina film was used as a substrate, and a Ta (3 nm) / N
iFe (2 nm) / Co (1 nm) / Cu (2.5 n
m) / a pinned layer having a synthetic pin structure with an interdiffusion layer inserted / PtMn (12 nm) / Ta (2n
m) are sequentially laminated to form a film, and 1200 mT (12 kG)
Annealing at a temperature of 270 ° C. for 5 hours in the magnetic field of FIG. The measurement magnetic field was 72000 A / m (90
0 Oe).

[0039]

[Table 2]

From Table 2, it is preferable to insert the interdiffusion layer 136 at a position where the thickness of the portion of the first ferromagnetic film 133a on the antiferromagnetic coupling film 133c side is 0.3 nm or more. This is to prevent the metal forming the interdiffusion layer 136 from being diffused as an impurity in the second ferromagnetic film 133b, thereby preventing the effect of spin-dependent scattering from deteriorating. Further, the mutual diffusion layer 13 is located at a position where the thickness of the first ferromagnetic film 133a on the side of the antiferromagnetic layer 134 becomes 0.2 nm or more.
Preferably, 6 is inserted. This is because the interdiffusion layer 13
This is for preventing the metal constituting 6 from being diffused into the antiferromagnetic layer 134 as an impurity.

FIG. 6 shows an SV according to another embodiment of the present invention.
FIG. 4 is a cross-sectional view illustrating a layer configuration of the MR multilayer structure, as viewed from an ABS direction.

In the present embodiment, the SVMR laminated structure includes an underlayer 130, an antiferromagnetic layer 134, a second ferromagnetic layer (pinned layer) 133, a nonmagnetic conductive layer 132, and a first ferromagnetic layer. The magnetic layer (free layer) 131 and the protective layer 135 are sequentially laminated.

The pinned layer 133 is formed of the first ferromagnetic film 133
a, the second ferromagnetic film 133b,
An antiferromagnetic coupling film 133c that separates 3a and 133b and antiferromagnetically couples has a synthetic pin structure.

In this embodiment, in particular, the antiferromagnetic layer 134
The interdiffusion layer 136 is inserted in the middle of the first ferromagnetic film 133a adjacent to. However, after annealing,
The metal component of the interdiffusion layer 136 is diffused in the first ferromagnetic film 133a of the pinned layer 133, and the metal component of the first ferromagnetic film 133a is diffused in the interdiffusion layer 136. I have.

As described above, in the present embodiment, the order of lamination of each layer of the SVMR laminated structure is reversed from that in the case of FIG. 2, and other configurations, functions and effects are the same as those of the previous embodiment. This is almost the same, and a resistance change ΔRs exceeding approximately 2.1Ω is obtained. In this embodiment, the same components as those in the previous embodiment are denoted by the same reference numerals.

Table 3 below shows the results obtained by preparing various samples and measuring ΔRs for various SVMR sensors having the laminated structure of the present embodiment but having different materials for the interdiffusion layers.

Each sample uses AlTiC with an alumina film as a substrate, and NiCr (3 nm)
/ PtMn (15 nm) / Pinned layer having synthetic pin structure and interdiffusion layer inserted / Cu (1.9 n
m) / CoFe (3 nm) / Ta (3 nm) are sequentially laminated to form a film, and the film is formed in a magnetic field of 1200 mT (12 kG).
Annealing is performed at a temperature of 0 ° C. for 5 hours. The measurement magnetic field is 72000 A / m (900 Oe).

[0048]

[Table 3]

As shown in Table 3, as the mutual diffusion layer 136, A
1, Si, Ti, V, Cr, Mn, Ga, Ge, Y, Z
r, Nb, Mo, Ru, Rh, Pd, In, Sn, H
When f, Ta, W, Pt, Re, Os, Ir, TaCo or TaNi are used, it can be seen that the resistance change ΔRs is larger in each case than in the comparative example having no interdiffusion layer.

In the embodiment described above, the mutual diffusion layer 136 is inserted in the center of the pinned layer 133 in the thickness direction of the first ferromagnetic film 133a.
6 may be at any position in the middle of the first ferromagnetic film 133a.

Table 4 below shows various SVMs in which the positions where the interdiffusion layers are inserted differ in the thickness direction of the first ferromagnetic film 133a.
For the R sensor, various samples were created and the results of measuring ΔRs are shown.

Each sample uses AlTiC with an alumina film as a substrate, and NiCr (3 nm)
/ PtMn (15 nm) / Pinned layer having synthetic pin structure and interdiffusion layer inserted / Cu (1.9 n
m) / CoFe (3 nm) / Ta (3 nm) are sequentially laminated to form a film, and the film is formed in a magnetic field of 1200 mT (12 kG).
Annealing is performed at a temperature of 0 ° C. for 5 hours. The measurement magnetic field is 72000 A / m (900 Oe).

[0053]

[Table 4]

According to Table 4, it is preferable to insert the interdiffusion layer 136 at a position where the thickness of the portion on the antiferromagnetic coupling film 133c side of the first ferromagnetic film 133a becomes 0.3 nm or more. This is to prevent the metal forming the interdiffusion layer 136 from being diffused as an impurity in the second ferromagnetic film 133b, thereby preventing the effect of spin-dependent scattering from deteriorating. Further, the mutual diffusion layer 13 is located at a position where the thickness of the first ferromagnetic film 133a on the side of the antiferromagnetic layer 134 becomes 0.2 nm or more.
Preferably, 6 is inserted. This is because the interdiffusion layer 13
This is for preventing the metal constituting 6 from being diffused into the antiferromagnetic layer 134 as an impurity.

Even if the interdiffusion layer is inserted in the middle of the second ferromagnetic film 133b, the resistance change ΔRs does not increase. Table 5 below shows the results obtained by preparing samples and measuring ΔRs for the case where the interdiffusion layer was not inserted and the case where the interdiffusion layer was inserted in the middle of the second ferromagnetic film 133b.

For each sample, AlTiC with an alumina film was used as a substrate, and a Ta (3 nm) / N
iFe (2 nm) / Co (1 nm) / Cu (1.8 n
m) / Pinned layer having synthetic pin structure / Pt
Mn (12 nm) / Ta (2 nm) is sequentially laminated to form a film, and annealing is performed at a temperature of 270 ° C. for 5 hours in a magnetic field of 1200 mT (12 kG). The measurement magnetic field is 72000 A / m (900 Oe).

[0057]

[Table 5]

As can be seen from Table 5, the second ferromagnetic film 1
When the interdiffusion layer is inserted in the middle of 33b, the resistance change ΔRs is lower than when no interdiffusion layer is inserted. This is because the metal constituting the interdiffusion layer 136 is diffused as an impurity in the second ferromagnetic film 133b close to the nonmagnetic conductive layer 132, and as a result, the effect of spin-dependent scattering deteriorates.

SVM without synthetic pin structure
Even if an interdiffusion layer is inserted into the pinned layer of the R element, the resistance change Δ
Rs does not increase. Table 6 below shows the results obtained by preparing samples and measuring ΔRs for the case where the interdiffusion layer was not inserted and the case where the interdiffusion layer was inserted in the SVMR element having no synthetic pin structure.

For each sample, AlTiC with an alumina film was used as a substrate, and a Ta (4 nm) / N
iFe (3 nm) / CoFe (1 nm) / Cu (2n
m) / Pinned layer without synthetic pin structure / P
tMn (15 nm) / Ta (3 nm) are sequentially laminated to form a film, and annealing is performed at a temperature of 270 ° C. for 5 hours in a magnetic field of 1200 mT (12 kG). The measurement magnetic field is 72000 A / m (900 Oe).

[0061]

[Table 6]

As can be seen from Table 6, when the interdiffusion layer is inserted in the pinned layer of the SVMR element having no synthetic pin structure, the resistance change ΔRs is lower than when no interdiffusion layer is inserted. This is because the metal forming the interdiffusion layer 136 is diffused as an impurity in the first ferromagnetic layer (pinned layer) close to the nonmagnetic conductive layer 132, and as a result, the effect of spin-dependent scattering deteriorates. It is.

Although the above embodiment relates to the SVMR sensor, it is apparent that the present invention can be applied to other GMR sensors and TMR sensors.

The embodiments described above all show the present invention by way of example and not by way of limitation, and the present invention can be embodied in other various modifications and alterations. Therefore, the scope of the present invention is defined only by the appended claims and their equivalents.

[0065]

As described above in detail, according to the present invention, the predetermined metal is diffused in a part of the pinned layer.
The sheet resistance Rs of the entire MR sensor increases. Generally, the resistance change ΔRs of the MR sensor is obtained by setting the MR change rate to M
Assuming that R and the sheet resistance are Rs, ΔRs [Ω] = MR
[%] × Rs [Ω]. Therefore, a high ΔRs can be obtained by increasing the sheet resistance Rs. As a result, the size of the MR sensor can be reduced, and an MR sensor and a thin-film magnetic head corresponding to high recording density can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view schematically showing a configuration of a main part of a thin-film magnetic head according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a layer configuration of the SVMR laminated structure of FIG. 1 as viewed from a floating surface (ABS) direction.

FIG. 3 shows a change in MR resistance ΔR when the thickness of a Ta film is changed.
It is a figure showing the result of having measured s.

FIG. 4 is a diagram showing the results of measuring the MR ratio MR when the thickness of the Ta film is changed.

FIG. 5 is a diagram showing the results of measuring sheet resistance Rs when the thickness of a Ta film is changed.

FIG. 6 is a sectional view showing a layer configuration of an SVMR laminated structure according to another embodiment of the present invention, as viewed from the ABS direction.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Substrate 11 Lower shield layer 12 Upper shield layer 12a, 16a Pole part 13 Spin valve MR layer 14, 15, 18 Insulating layer 16 Upper magnetic layer 17 Coil conductive layer 19 Gap layer 20, 135 Protective layer 130 Underlayer 131 Second Ferromagnetic layer (free layer) 136 Interdiffusion layer 132 Nonmagnetic conductive layer 133 First ferromagnetic layer (pinned layer) 133a First ferromagnetic film 133b Second ferromagnetic film 133c Antiferromagnetic coupling film 134 Anti-strong Magnetic layer 136 Mutual diffusion layer

Claims (11)

[Claims] 1. An antiferromagnetic layer, a first ferromagnetic layer laminated adjacent to the antiferromagnetic layer, and a nonmagnetic layer laminated adjacent to the first ferromagnetic layer And a second ferromagnetic layer stacked adjacent to the non-magnetic layer, wherein a magnetoresistance utilizing a bias magnetic field due to exchange coupling between the antiferromagnetic layer and the first ferromagnetic layer is provided. An effect sensor,
The first ferromagnetic layer includes first and second ferromagnetic films separated by an antiferromagnetic coupling film and antiferromagnetically coupled to each other, and the first ferromagnetic layer is adjacent to the antiferromagnetic layer. A magnetoresistive sensor, wherein a predetermined metal is diffused into at least a part of the ferromagnetic film. 2. An interdiffusion layer of the predetermined metal, in which a metal constituting the first ferromagnetic film is diffused, is formed in the middle of the first ferromagnetic film. Item 2. The sensor according to Item 1. 3. The method according to claim 1, wherein the interdiffusion layer has a thickness of 0.05 to 0.4 n.
The sensor according to claim 2, wherein the sensor has a thickness of m. 4. The method according to claim 1, wherein the predetermined metal is Al, Si, Ti,
V, Cr, Mn, Ga, Ge, Y, Zr, Nb, Mo,
Ru, Rh, Pd, In, Sn, Hf, Ta, W, R
2. A metal containing at least one selected from the group consisting of e, Os, Ir and Pt.
The sensor according to any one of claims 1 to 3. 5. A thin-film magnetic head comprising the magneto-resistance effect sensor according to claim 1. Description: 6. A first ferromagnetic film composed of an underlayer, a second ferromagnetic layer, a nonmagnetic layer, and a first and second ferromagnetic films separated by an antiferromagnetic coupling film and antiferromagnetically coupled to each other. A method for manufacturing a magnetoresistive effect sensor formed by sequentially stacking a ferromagnetic layer and an antiferromagnetic layer, wherein the first ferromagnetic film adjacent to the antiferromagnetic layer has an intermediate layer formed of a predetermined metal. A method for manufacturing a magnetoresistive sensor, comprising: forming a diffusion layer; and diffusing the predetermined metal into at least a part of the first ferromagnetic film. 7. A first ferromagnetic layer comprising a first and second ferromagnetic films separated by an underlayer, an antiferromagnetic layer, and an antiferromagnetic coupling film and antiferromagnetically coupled to each other; A method of manufacturing a magnetoresistive sensor formed by sequentially laminating a first ferromagnetic layer and a second ferromagnetic layer, the first ferromagnetic film being adjacent to the antiferromagnetic layer and being interposed by a predetermined metal. A method for manufacturing a magnetoresistive sensor, comprising: forming a diffusion layer; and diffusing the predetermined metal into at least a part of the first ferromagnetic film. 8. The method according to claim 1, wherein the mutual diffusion layer has a thickness of 0.05 to 0.4 n.
The method according to claim 6, wherein the film is formed to have a thickness of m. 9. The semiconductor device according to claim 6, wherein a protective layer is laminated on the antiferromagnetic layer or the second ferromagnetic layer.
The production method according to any one of the above. 10. The method according to claim 10, wherein the predetermined metal is Al, Si, Ti,
V, Cr, Mn, Ga, Ge, Y, Zr, Nb, Mo,
Ru, Rh, Pd, In, Sn, Hf, Ta, W, R
7. A metal containing at least one selected from the group consisting of e, Os, Ir and Pt.
10. The production method according to any one of items 1 to 9. 11. A method for manufacturing a thin-film magnetic head, wherein a magnetoresistive sensor used for reproducing magnetic information is formed by the manufacturing method according to any one of claims 6 to 10.