JP2003298147A - Magneto-resistance effect element, magnetic head, head suspension assembly and magnetic disk device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To have a structure obtained by laminating a magnetic domain control film applying a bias magnetic field to a free layer on a magneto-resistance effect layer, and simultaneously to obtain, in the free layer, the bias magnetic field enough to suppress Barkhausen noises even if a valid track width is narrow. <P>SOLUTION: An antiferromagnetic layer 23 laminated through a non-magnetic metal layer 24 on a free layer 25 applies an exchange coupling magnetic field to the free layer 25 in a track width direction as a bias magnetic field. The antiferromagnetic layer 23, non-magnetic metal layer 24 and free layer 25 are formed so as to range from a valid area of the magneto-resistance effect layer to an area expanding on both sides in the track width direction. <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 magnetoresistive effect element, and a magnetic head, a head suspension assembly and a magnetic disk device using the same.

[0002]

2. Description of the Related Art As the capacity of a hard disk drive (HDD) becomes smaller and smaller, a head having high sensitivity and high output is required. In response to the demand, the characteristics of the current product GMR head (Giant Magneto-Resistive Head) are being improved steadily, while the tunnel magnetoresistive head that can be expected to have a resistance change rate more than double that of the GMR head. (TM
R head) is also being actively developed.

GMR heads and TMR heads generally have different head structures due to the difference in the direction in which a sense current flows. A head structure, such as a general GMR head, in which a sense current flows in parallel to the film surface is formed by CIP (Current In Plan).
e) structure, a head structure such as a TMR head for flowing a sense current perpendicularly to the film surface is referred to as CPP (Current Perpendi
cular to Plane) structure. In the CPP structure, since the magnetic shield itself can be used as an electrode, C
Magnetic shield-element short circuit (insulation failure), which is a serious problem in narrowing the read gap of IP structure
Essentially does not occur. Therefore, the CPP structure is very advantageous in increasing the recording density.

As the head of the CPP structure, in addition to the TMR head, for example, a spin valve (SV) film (including a specular type and a dual spin valve type magnetic multilayer film) is used for the magnetoresistive effect element, but the CPP structure is also used. With C
PP-GMR heads are also known. The CPP-GMR head is drawing attention because it can reduce the resistance, which is a problem with the TMR head.

In a head using an SV film or TMR film,
In both the CIP structure and the CPP structure, it is necessary to apply a bias magnetic field to the free layer in the track width direction in order to suppress Barkhausen noise. In general,
In the CIP structure, the resist mask used for milling that defines the track width is used as it is, and a hard magnetic film such as CoCrPt is formed as a magnetic domain control film on both sides of the magnetoresistive effect layer by the lift-off method. This is called an Abutted structure. Further, in the CIP structure, there is also a lead overlay structure (LOL structure) in which the track width is not defined by the hard magnetic layer arranged in the abutted structure and the lead is arranged so as to cover the magnetoresistive effect layer inside thereof. There is. CPP
In terms of structure, as with the CIP-GMR head, Abut
A bias magnetic field is applied to the free layer by the ted structure (for example, JP 2000-30223 A, JP 20 A).
01-14616, etc.).

As described above, in both types of heads, the bias magnetic field is applied to the free layer by Abutted
It is generally realized by a structure.

In contrast, a paper by Nakashio et al. ("Longitu
dinal bias method using a long distance exchange c
oupling field in tunnel magnetoresistance junction
s ", Journal of Applied Physics, Vol.89, No.11, pp.1
-3 (1 June 2001)) and Japanese Patent Laid-Open No. 2001-68759, an antiferromagnetic layer such as IrMn as a magnetic domain control film for applying a bias magnetic field to the free layer is laminated on the free layer of the magnetoresistive effect layer. A magnetoresistive effect element (TMR element) has been proposed. In this TMR element, a nonmagnetic metal layer such as Cu is formed on the free layer on the tunnel barrier layer, and the antiferromagnetic layer is formed on this nonmagnetic metal layer. In this TMR element, the tunnel barrier layer, the free layer, the nonmagnetic metal layer, and the antiferromagnetic layer are formed only in the regions that substantially overlap each other, and the sizes of the respective layers in the film surface direction are substantially the same.

According to this TMR element, the exchange coupling magnetic field of the antiferromagnetic layer is applied as a bias magnetic field to the free layer in the track width direction via the nonmagnetic metal layer. As a result, the magnetic domain of the free layer is controlled without fixing the magnetization direction of the free layer, and Barkhausen noise is suppressed.

In the structures disclosed in the above-mentioned paper and Japanese Patent Application Laid-Open No. 2001-68759, since the magnetic domain control film is laminated on the magnetoresistive effect layer, unlike the Abutted structure, a hard magnetic layer is provided around the magnetoresistive effect layer. It is not necessary to form a film, and it is possible to obtain an advantage that, for example, the manufacturing process can be simplified.

[0010]

However, as a result of the research conducted by the inventor of the present invention, the above-mentioned paper and JP 2001-6875 A have been proposed.
In the structure disclosed in Japanese Patent No. 9 publication, when the effective track width of the magnetoresistive effect element is reduced, there arises a problem that the bias magnetic field for suppressing Barkhausen noise becomes insufficient due to the demagnetizing field of the free layer. There was found.

The present invention has been made in view of the above circumstances, and has a structure in which a magnetic domain control film for applying a bias magnetic field to a free layer is laminated on a magnetoresistive effect layer, and the effective track width is narrow, An object of the present invention is to provide a magnetoresistive effect element capable of obtaining a sufficient bias magnetic field in the free layer to suppress Barkhausen noise.

It is another object of the present invention to provide a magnetic head, a head suspension assembly and a magnetic disk device which are compatible with high recording density by using such a magnetoresistive effect element.

[0013]

In order to solve the above-mentioned problems, the magnetoresistive effect element according to the first aspect of the present invention comprises:
(A) A magnetoresistive effect layer formed on one surface side of the substrate and including a free layer, and mainly on the one surface side of the free layer on the same side of the substrate as the free layer. An antiferromagnetic layer for applying a bias magnetic field in a predetermined direction of the film surface of the free layer,
(B) An overlapping region of the free layer and the antiferromagnetic layer is substantially continuous with an effective region of the magnetoresistive layer in the film surface direction, which is effectively involved in magnetic detection, and is continuous from this region. The effective area includes a substantially non-overlapping area, and (c) the substantially non-overlapping area includes an area on at least one side in the predetermined direction with respect to the substantially overlapping area.

In the first aspect, the antiferromagnetic layer is formed on one surface side of the free layer. Therefore, also in the first aspect, the paper and Japanese Patent Laid-Open No. 2001-68
Like the magnetoresistive effect element disclosed in Japanese Patent No. 759,
The exchange coupling magnetic field of the antiferromagnetic layer is applied to the free layer as a bias magnetic field, whereby the magnetic domain of the free layer is controlled and Barkhausen noise is suppressed without fixing the magnetization direction of the free layer. By the way, in the magnetoresistive effect element disclosed in the above-mentioned paper and Japanese Patent Application Laid-Open No. 2001-68759, in order to prevent the magnetization direction of the free layer from being fixed, a nonmagnetic layer is formed between the free layer and the antiferromagnetic layer. It was considered necessary to interpose a metal layer. However, it was found that when the effective track width of the magnetoresistive effect element is made extremely small, the magnetization direction of the free layer may not be fixed without the interposition of the nonmagnetic metal layer. It has been found that the nonmagnetic metal layer between the free layer and the antiferromagnetic layer may be provided if necessary. Therefore, in the first aspect, it is not always necessary to provide the nonmagnetic metal layer.

In the magnetoresistive element disclosed in the above-mentioned paper and Japanese Patent Laid-Open No. 2001-68759, the tunnel barrier layer, the free layer, the nonmagnetic metal layer and the antiferromagnetic layer are formed only in the regions which substantially overlap each other. The size of each layer in the film surface direction was almost the same. That is, in this conventional magnetoresistive effect element, the free layer, the nonmagnetic metal layer, and the antiferromagnetic layer are only the areas that substantially overlap with the effective area in the film surface direction that is effectively involved in the magnetic detection in the magnetoresistive effect layer. Was formed. Therefore, in the conventional magnetoresistive effect element, when the width (effective track width) of the effective region in the track width direction (direction of applying a bias magnetic field to the free layer) is narrowed, the free layer and the nonmagnetic metal layer are inevitably formed. In addition, the width of the antiferromagnetic layer in the track width direction also becomes narrower, and as a result, there arises a problem that the bias magnetic field for suppressing Barkhausen noise is insufficient due to the influence of the demagnetizing field of the free layer.

On the other hand, in the first aspect, the free layer and the antiferromagnetic layer are not only the region which substantially overlaps with the effective region of the magnetoresistive effect layer, but also the continuous region from this region and the effective region. Is also formed so as to spread over a region that does not overlap with each other, and extends over at least one region in the bias magnetic field application direction (track width direction) with respect to the region that substantially overlaps with the effective region. Therefore, according to the first aspect, even if the effective track width is narrow, the demagnetizing field of the free layer is relaxed, and a sufficient bias magnetic field for suppressing Barkhausen noise can be obtained in the free layer.

The magnetoresistive effect element according to the second aspect of the present invention is the magnetoresistive element according to the first aspect, further comprising a nonmagnetic metal layer interposed between the free layer and the antiferromagnetic layer. . The second aspect is based on the above-mentioned paper and Japanese Patent Laid-Open No. 2001
This is an example in which a non-magnetic metal layer is interposed, like the magnetoresistive effect element disclosed in Japanese Patent Publication No.-68759.

A magnetoresistive effect element according to a third aspect of the present invention is the magnetoresistive effect element according to the first or second aspect, wherein the substantially non-overlapping regions are regions on both sides of the substantially overlapping region in the predetermined direction. Is included.

In the first and second aspects, the overlapping region of the free layer and the antiferromagnetic layer is located on one side in the bias magnetic field applying direction (track width direction) with respect to the region substantially overlapping the effective region. You may make it extend only to. However, as in the third aspect, the overlapping region of the free layer and the antiferromagnetic layer extends to the regions on both sides in the bias magnetic field application direction (track width direction) with respect to the region substantially overlapping the effective region. Then, the influence of the demagnetizing field of the free layer is further alleviated, and a more sufficient bias magnetic field for suppressing Barkhausen noise can be obtained in the free layer, which is preferable.

The magnetoresistive effect element according to a fourth aspect of the present invention is the magnetoresistive element according to the third aspect, wherein the center of the width in the predetermined direction of the overlapping region of the free layer and the antiferromagnetic layer is:
It is located near the center of the width of the effective area in the predetermined direction.

When the centers of the respective widths in the bias magnetic field applying direction are made to substantially coincide with each other as in the fourth aspect, the influence of the demagnetizing field of the free layer is further alleviated, and Barkhausen noise is suppressed. It is preferable because a more sufficient bias magnetic field can be obtained in the free layer.

A magnetoresistive effect element according to a fifth aspect of the present invention is the magnetoresistive element according to any one of the first to fourth aspects, wherein the overlapping region of the free layer and the antiferromagnetic layer is orthogonal to the predetermined direction. The width in the direction is substantially the same as the width of the effective region in the direction orthogonal to the predetermined direction.

In the first to fourth aspects, the overlapping region of the free layer and the antiferromagnetic layer is formed in a direction (MR) which is orthogonal to the bias magnetic field applying direction from the region substantially overlapping the effective region.
You may form so that it may also reach | attain the area | region of the (width of height direction) side. However, it is not always necessary to increase the width of the free layer or the like in the MR height direction, and the
In order to increase the ratio described in the above aspect to further alleviate the influence of the demagnetizing field of the free layer, it is preferable that the widths be substantially the same as in the fifth aspect.

A magnetoresistive effect element according to a sixth aspect of the present invention is the magnetoresistive element according to any one of the first to fifth aspects, wherein the overlapping region of the free layer and the antiferromagnetic layer is orthogonal to the predetermined direction. The ratio of the width in the predetermined direction to the width in the direction is 2 or more.

As a result of the research conducted by the present inventor, as will be described later,
If the ratio is 2 or more when the track width is 0.2 μm or less, the demagnetizing field of the free layer is further relaxed, and a more sufficient bias magnetic field for suppressing Barkhausen noise can be obtained in the free layer. It turns out that you can. The ratio is more preferably 2.6 or more,
It is even more preferably 3.4 or more.

The magnetoresistive effect element according to the seventh aspect of the present invention is the magnetoresistive element according to any one of the first to sixth aspects,
(A) a first electrode formed between the base and one of the magnetoresistive effect layer and the antiferromagnetic layer formed closest to the base, and the magnetoresistive effect layer, A non-magnetic metal layer and a second electrode formed on the side of the antiferromagnetic layer that is the most opposite to the side of the base, the second electrode being formed on the side opposite to the side of the base; b) The magnetoresistive effect layer is formed on the tunnel barrier layer or the nonmagnetic layer formed on the other surface side of the free layer and on the side of the tunnel barrier layer or the nonmagnetic layer opposite to the free layer. A pinned layer formed on a side of the pinned layer opposite to the tunnel barrier layer or the non-magnetic layer, and (c) the effective region includes the first electrode and the first electrode. A film surface direction in which a current flows between the two electrodes in a direction substantially perpendicular to the film surface Those which are in the area.

In the seventh aspect, the magnetoresistive effect element according to the first to sixth aspects is provided with a TMR having a CPP structure.
This is an example applied to a device and a CPP-GMR device. However, the first to sixth aspects are not limited to these elements, and are, for example, CIP-G.
It can also be applied to MR elements and the like.

The magnetoresistive effect element according to an eighth aspect of the present invention is the magnetoresistive element according to the seventh aspect, wherein at least one of the pinned layer and the pinned layer is formed only in a region substantially overlapping the effective region. It was done.

The eighth aspect exemplifies the layer capable of defining the effective area, but the element defining the effective area is not limited to these.

A magnetic head according to the ninth aspect of the present invention is
The magnetoresistive effect element comprises a base and a magnetoresistive effect element supported by the base, and the magnetoresistive effect element is the magnetoresistive effect element according to any one of the first to eighth aspects.

According to the ninth aspect, since the magnetoresistive effect element according to any one of the first to seventh aspects is used, Barkhausen noise is sufficiently suppressed even in a narrow track, and high recording is achieved. It is possible to increase the density.

A head suspension assembly according to a tenth aspect of the present invention is provided with the magnetic head according to the ninth aspect, and a suspension for mounting the magnetic head near the tip end portion and supporting the magnetic head. is there. According to the tenth aspect, since the magnetic head according to the ninth aspect is used, it is possible to increase the recording density of the magnetic disk device or the like.

A magnetic disk drive according to an eleventh aspect of the present invention is a head suspension assembly according to the tenth aspect, an arm portion for supporting the assembly, and an actuator for moving the arm portion to position the magnetic head. And ,. According to the eleventh aspect, since the magnetic head according to the tenth aspect is used, high recording density can be achieved.

[0034]

BEST MODE FOR CARRYING OUT THE INVENTION A magnetoresistive effect element according to the present invention, and a magnetic head, a head suspension assembly and a magnetic disk device using the same will be described below with reference to the drawings.

[First Embodiment]

FIG. 1 is a schematic perspective view schematically showing a magnetic head according to the first embodiment of the present invention. Figure 2
FIG. 2 is an enlarged cross-sectional view schematically showing a TMR element 2 and an inductive magnetic conversion element 3 of the magnetic head shown in FIG. 1. Figure 3
FIG. 3 is a schematic view taken along the line AA ′ in FIG. 4 is shown in FIG.
It is the enlarged view which further expanded the TMR element 2 vicinity inside. FIG. 5 is an enlarged view in which the vicinity of the TMR element 2 in FIG. 3 is further enlarged. FIG. 6 is a view taken along the line BB ′ in FIG. To facilitate understanding, X-axis, Y-axis, and Z-axis that are orthogonal to each other are defined as shown in FIGS. 1 to 6 (the same applies to the figures described later). The direction of the arrow in the Z-axis direction is called the + Z direction or the + Z side, and the opposite direction is called the -Z direction or the -Z side, and the same applies to the X-axis direction and the Y-axis direction. The X-axis direction coincides with the moving direction of the magnetic recording medium. The Z axis direction coincides with the track width direction of the TMR element 2.

As shown in FIG. 1, the magnetic head according to the first embodiment has a slider 1 as a substrate, a TMR element 2 as a magnetoresistive effect element used as a reproducing magnetic head element, and a magnetic recording element. An inductive magnetic conversion element 3 as a head element and a protective film 4 made of a DLC film or the like are provided and configured as a composite magnetic head. However, the magnetic head according to the present invention is, for example, the TMR element 2
It may be equipped with only. Further, in the first embodiment, each of the elements 2 and 3 is provided one by one,
The number is not limited in any way.

The slider 1 has rail portions 11 and 12 on the side facing the magnetic recording medium, and the surfaces of the rail portions 11 and 12 are A.
It constitutes BS (air bearing surface). In the example shown in FIG. 1, the number of rail portions 11 and 12 is two, but the number is not limited to this. For example, it may have 1 to 3 rail portions, or the ABS may be a flat surface having no rail portions. Further, the ABS may be provided with various geometrical shapes in order to improve the floating characteristics. The magnetic head according to the present invention may have any type of slider.

In the first embodiment, the protective film 4 is provided only on the surfaces of the rail portions 11 and 12, and the surface of the protective film 4 constitutes ABS. However, the protective film 4 may be provided on the entire surface of the slider 1 facing the magnetic recording medium. Although it is preferable to provide the protective film 4, it is not always necessary to provide the protective film 4.

TMR element 2 and induction type magnetic conversion element 3
Is provided on the side of the air outflow end portion TR of the rail portions 11 and 12, as shown in FIG. The recording medium movement direction is
It coincides with the X-axis direction in the figure, and coincides with the outflow direction of air that moves when the magnetic recording medium moves at high speed. Air enters from the inflow end LE and flows out from the outflow end TR. Bonding pads 5a and 5b connected to the TMR element 2 and bonding pads 5c and 5d connected to the inductive magnetic conversion element 3 are provided on the end surface of the air outflow end portion TR of the slider 1.
Is provided.

TMR element 2 and inductive magnetic conversion element 3
2 is laminated on a base layer 16 provided on a ceramic substrate 15 which constitutes the slider 1, as shown in FIGS. The ceramic base 15 is usually made of AlTiC (Al ₂ O ₃ —TiC) or SiC. When Al ₂ O ₃ —TiC is used, since it has conductivity, an insulating film made of, for example, Al ₂ O ₃ is used as the underlayer 16. The base layer 16 may not be provided in some cases.

As shown in FIGS. 4 and 5, the TMR element 2 includes a lower electrode 21 formed on the underlayer 16 and an upper electrode 31 formed on the upper side of the lower electrode 21 (the side opposite to the base 15). A lower metal layer 22, an antiferromagnetic layer 23, a nonmagnetic metal layer 24, a free layer 25, a tunnel barrier layer 26, a pinned layer 27, and a pinned layer, which are sequentially stacked between the electrodes 21 and 31 from the lower electrode 21 side. 28 and an upper metal layer (cap layer) 29 as a non-magnetic metal layer serving as a protective film. The free layer 25, the tunnel barrier layer 26, the pinned layer 27 and the pinned layer 28 form a magnetoresistive effect layer. The actual TMR element 2 generally has a multi-layered film structure instead of the illustrated film structure of the number of layers. However, in the magnetic head shown in the figure, the TMR element 2 has a TMR element for simplification of description. The minimal film structure required for basic operation of device 2 is shown.

In the first embodiment, the lower electrode 21 and the upper electrode 31 are also used as the lower magnetic shield and the upper magnetic shield, respectively. The electrodes 21 and 31 are
For example, it is formed of a magnetic material such as NiFe. Although not shown in the drawing, these electrodes 21 and 31 are electrically connected to the above-mentioned bonding pads 5a and 5b, respectively. The lower electrode 21 and the upper electrode 3
It goes without saying that, apart from 1, the lower magnetic shield and the upper magnetic shield may be provided.

The lower metal layer 22 is a conductor,
For example, a Ta layer and a Ni layer, which are sequentially stacked from the base 15 side.
It is composed of a stack of Fe layers and the like.

The antiferromagnetic layer 23 is exchange-coupled with the free layer 25 through the nonmagnetic metal layer 24, so that the exchange coupling magnetic field is used as a bias magnetic field without fixing the magnetization direction of the free layer 25. In the Z-axis direction (track width direction). The antiferromagnetic layer 23 is, for example, P
tMn, IrMn, RuRhMn, FeMn, NiM
Mn such as n, PdPtMn, RhMn or CrMnPt
It is formed of an n-based alloy. The nonmagnetic metal layer 24 is, for example,
It is formed of Cu, Ru, Rh, Ta, Cr, Au, Ag, or the like. If the nonmagnetic metal layer 24 is too thin, the antiferromagnetic layer 2
3 and the free layer 25 have too strong an exchange coupling, and the free layer 2
The magnetization direction of No. 5 is fixed, and the magnetic detection operation may be disabled. On the other hand, if the nonmagnetic metal layer 24 is too thick, the exchange coupling between the antiferromagnetic layer 23 and the free layer 25 is too weak, and a sufficient bias magnetic field cannot be applied to the free layer 25. Further, when the effective track width of the TMR element 2 is made extremely small, the magnetization direction of the free layer is not fixed without interposing the nonmagnetic metal layer 24, while the free layer 25 has a sufficient magnetization direction. In some cases, it may be preferable not to interpose the non-magnetic metal layer 24 to provide a bias magnetic field. The necessity and thickness of the non-magnetic metal layer 24 are determined in consideration of these.

The free layer 25 and the pinned layer 27 are each composed of a ferromagnetic layer, and are made of, for example, Fe, Co, Ni, F.
It is formed of a material such as eCo, NiFe, CoZrNb, or FeCoNi. The pinned layer 28 is composed of an antiferromagnetic layer, and includes, for example, PtMn, IrMn, RuRhMn, F.
eMn, NiMn, PdPtMn, RhMn or CrM
It is preferably formed of an Mn-based alloy such as nPt. The magnetization direction of the pinned layer 27 is fixed in the Y-axis direction by an exchange coupling bias magnetic field with the pinned layer 28.
On the other hand, as described above, the bias magnetic field is applied to the free layer 26, but the direction of magnetization is basically changed in response to an external magnetic field which is basically magnetic information. The tunnel barrier layer 26 is made of, for example, Al ₂ O ₃ , NiO,
It is formed of a material such as GdO, MgO, Ta ₂ O ₅ , MoO ₂ , TiO ₂ or WO ₂ .

The upper metal layer 29 is made of, for example, Ta, Rh,
It is formed as a single-layer film or a multi-layer film using Ru, Os, W, Pd, Pt, or Au alone or an alloy composed of a combination of any two or more of these.

In the first embodiment, as shown in FIGS. 4 to 6, the sizes of the tunnel barrier layer 26, the pinned layer 27, the pinned layer 28, and the upper metal layer 29 in plan view seen from the X-axis direction. Is defined according to the desired track width TW and MR height h. Strictly speaking, layers 26-29 are
As will be described later, the size in plan view is determined by simultaneously performing ion milling, and the + Z side and −Z side thereof are determined.
Since the side surface and the −Y side end surface are tapered surfaces as shown in FIGS. 4 and 5, the lower layers of the layers 26 to 29 are slightly larger, but the size in plan view is substantially the same. Can be said to be the same. In FIG. 6, for the layers 26 to 29, only the upper metal layer 29 is shown, and the size in plan view is TW × h. The layers 26 to
An end surface of 29 on the + Y side (ABS side) is determined by lapping processing described later and is perpendicular to the film surface.

As described above, in the first embodiment, the sizes of the tunnel barrier layer 26, the pinned layer 27, the pinned layer 28, and the upper metal layer 29 in plan view when viewed from the X-axis direction are the track widths TW and MR. Since the height is defined according to the height h, the tunnel barrier layer 26, the pinned layer 27, and the pinned layer 28.
The upper metal layer 29 and the upper metal layer 29 are effective regions in the film surface direction that effectively participate in the magnetic detection in the magnetoresistive layer (in the present embodiment, a current flows between the electrodes 21 and 31 in a direction substantially perpendicular to the film surface). It is formed only in a region that substantially overlaps with the region in the film surface direction). In other words, in the first embodiment, the tunnel barrier layer 26, the pinned layer 27, the pinned layer 28 and the upper metal layer 29 define the effective region. However, any one or more of the pinned layer 27, the pinned layer 28, and the upper metal layer 29 may extend to a region other than a region that substantially overlaps the effective region.

On the other hand, in the first embodiment, the antiferromagnetic layer 23, the nonmagnetic metal layer 24, and the free layer 25 are, as shown in FIGS. 2 to 6, a region which substantially overlaps the effective region. A region which is continuous from this region and does not substantially overlap with the effective region, and the substantially non-overlapping region is on both sides in the Z-axis direction (track width direction) with respect to the substantially overlapping region. Contains areas. That is, in the first embodiment, the antiferromagnetic layer 23 and the nonmagnetic metal layer 2
4 and the free layer 25 are formed in the area of w × h1, as shown in FIG. The area of w × h1 includes the effective area (area of TW × h), and an area on the + Z side and an area on the −Z side with respect to the effective area. Therefore, w>
It is TW. Strictly speaking, layers 23-25 are simultaneously ion milled as described below,
The size in plan view is determined, and the + Z side, −Z side, and −Y side end surfaces thereof are tapered surfaces as shown in FIGS. 4 and 5, so that the lower layer of the layers 23 to 25 is Although they are slightly larger, the sizes in plan view can be said to be substantially the same. In FIG. 6, for layers 23-25,
Only the free layer 25 is shown, and its size in plan view is w.
It is shown as xh. In addition, the layers 23 to 29-
Since the end surface on the Y side is a continuous tapered surface due to ion milling of these layers at the same time,
Strictly speaking, the width h1 is wider than the width h, but the width h1 and the width h
Can be said to be substantially the same. However, in FIG.
For easy understanding, h1> h is shown. The + Y side of the layers 23 to 25 (the end surface on the ABS side) is the layer 2
Together with the + Y side end faces of 6 to 29, they are determined by the lapping process described later and are perpendicular to the film surface.

As can be seen from the above description, in the first embodiment, the overlapping region of the antiferromagnetic layer 23, the nonmagnetic metal layer 24 and the free layer 25 is from the effective region (region of TW × h). The area (w × h1≈w × h) spreads out on both sides in the Z-axis direction (track width direction). However,
The overlapping region of the antiferromagnetic layer 23, the nonmagnetic metal layer 24, and the free layer 25 may extend to only one side of the effective region in the Z-axis direction. However, when the overlapping regions of the layers 23 to 25 extend to both sides of the effective region, the influence of the demagnetizing field of the free layer 25 is further alleviated, and Barkhausen noise is further suppressed by the bias magnetic field applied from the antiferromagnetic layer 23. Is preferred.

Further, in the first embodiment, as described above, the width h1 of the antiferromagnetic layer 23, the nonmagnetic metal layer 24 and the free layer 25 in the Y-axis direction and the width of the effective region in the Y-axis direction. h is substantially equal to each other, and the overlapping region of the antiferromagnetic layer 23, the nonmagnetic metal layer 24, and the free layer 25 does not extend to the −Y axis side of the effective region. However, in the present invention, the overlapping region of the antiferromagnetic layer 23, the nonmagnetic metal layer 24, and the free layer 25 may extend to the −Y axis side. However,
The width in the Y-axis direction of the overlapping region of the layers 23 to 25 does not necessarily need to be increased excessively, and as described later, the ratio w
In order to increase / h1 and further reduce the influence of the demagnetizing field of the free layer 25, it is preferable that the width h1 be substantially the same as the width h.

Further, in the first embodiment, the center of the width w in the Z-axis direction of the overlapping region of the antiferromagnetic layer 23, the nonmagnetic metal layer 24 and the free layer 25 is in the Z-axis direction of the effective region. It is located near the center of the width TW. However, the center of the width w does not necessarily have to be located near the center of the width TW. However, when the width w is not so wide, the influence of the demagnetizing field of the free layer 25 is further alleviated, which is preferable.

The ratio w / h1 of the width w in the Z-axis direction (track width direction) to the width h1 in the Y-axis direction of the antiferromagnetic layer 23, the non-magnetic metal layer 24 and the free layer 25 (in the present embodiment,
w / h1≈w / h) is preferably 2 or more.
This was found from the simulation results described later (see the section “Examples”). The ratio is more preferably 2.6 or more and even more preferably 3.4 or more. However, if substantially w> h, the influence of the demagnetizing field of the free layer 25 is alleviated and Barkhausen noise is suppressed, as compared with the case where substantially w = h as in the above-described conventional technique. It

In the present embodiment, the lower metal layer 22
Are milled together with layers 23-25 and layers 23-25
And practically just overlap. However, the lower metal layer 22 may be formed in a region wider than the layers 23 to 25, for example.

As shown in FIGS. 2 to 6, the electrodes 21 and 3 are
1, the insulating layer 30 is formed around the layers 23 to 29, and the hard magnetic layers formed on both sides of the magnetoresistive layer in the abutted structure are not formed. Insulating layer 30
Is, for example, Al ₂ O ₃ , SiO ₂ , MgO or TiO
It is formed of a material such as ₂ .

As shown in FIGS. 2 and 3, the inductive magnetic conversion element 3 is composed of the upper electrode 31, the upper magnetic layer 36, the coil layer 37, alumina, etc., which also serves as the lower magnetic layer for the element 3. A light gap layer 38, an insulating layer 39 made of an organic resin such as a novolac resin, and a protective layer 40 made of alumina or the like. Element 3
Alternatively, the lower magnetic layer and the upper electrode 31 may not be used in common, but they may be separated by a non-magnetic layer. As the material of the magnetic layer 36, for example, NiFe or FeN is used.
The tip portions of the upper electrode 31 and the upper magnetic layer 36, which also serve as the lower magnetic layer, are the lower pole portion 31a and the upper pole portion 36a which face each other across the write gap layer 38 such as alumina having a small thickness. Lower pole part 31
Information is written to the magnetic recording medium at a and the upper pole portion 36a. The upper electrode 31 and the upper magnetic layer 36, which are also used as the lower magnetic layer, have a yoke portion on the side opposite to the lower pole portion 31a and the upper pole portion 36a. Are combined. Inside the insulating layer 39, the coil layer 37 is formed so as to spiral around the coupling portion 41 of the yoke portion. Both ends of the coil layer 37 are
It is electrically connected to the above-mentioned bonding pads 5c and 5d. The number of turns and the number of layers of the coil layer 37 are arbitrary. Further, the structure of the inductive magnetic conversion element 3 may be arbitrary.

Next, an example of the method of manufacturing the magnetic head according to the present embodiment will be described.

First, a wafer process is performed. That is, a wafer 101 such as Al ₂ O ₃ —TiC or SiC to be the base 15 is prepared, and the wafer 1 is formed by using a thin film forming technique or the like.
Each of the layers described above is formed in the formation region of a large number of magnetic heads in a matrix on 01 so as to have the above-described structure.

The outline of this wafer process will be described with reference to FIGS. 7 to 10 are diagrams schematically showing each step constituting the wafer step.
(A), FIG. 8 (a), FIG. 9 (a) and FIG. 10 (a) are schematic plan views, respectively. 7B is a schematic cross-sectional view taken along the line C-D in FIG. 7A, and FIG. 8B is FIG. 8A.
9 is a schematic cross-sectional view taken along the line C-D in FIG.
FIG. 10B is a schematic cross-sectional view taken along the line EF in FIG.
FIG. 11 is a schematic cross-sectional view taken along the line C-D in FIG. 8A, 9A, and 10A, TW indicates the track width defined by the TMR element 2, and w indicates the antiferromagnetic layer 23, the nonmagnetic metal layer 24, and the free layer. The widths of 25 in the Z-axis direction (track width direction) are shown, and these correspond to the same reference numerals in FIG. 6, respectively.

In the wafer process, first, the underlying layer 16, the lower electrode 21, the lower metal layer 22, the antiferromagnetic layer 23, the nonmagnetic metal layer 24, the free layer 25, the tunnel barrier layer 26, the pinned layer are formed on the wafer 101. 27, the pinned layer 28, and the upper metal layer 29 are sequentially laminated (FIG. 7). At this time, the lower electrode 21 is formed by, for example, a plating method, and the other layers are formed by, for example, a sputtering method.

Next, by the first ion milling, the tunnel barrier layer 26, the pinned layer 27, and the pinned layer 28 are left, leaving a strip portion extending in the Y-axis direction corresponding to the track width TW.
And the upper metal layer 29 is removed. At this time, the first ion milling completely stops the tunnel barrier layer 26, but stops the free layer 25 at a position where it is hardly removed. However, the first ion milling is, for example,
It may be stopped just above the tunnel barrier layer 26. Such a stop position is, for example, SIMS (Secondary
It can be set appropriately by monitoring the substance that appears during milling with an Ion-microprobe Mass Spectrometer (secondary ion mass spectrometer). After the first ion milling, the lift-off method is used to perform the first ion milling.
An insulating layer 30 ′ to be a part of the insulating layer 30 is formed on the portion removed by the ion milling (1) (FIG. 8).

Then, by the second ion milling, T
The lower metal layer 22 and the antiferromagnetic layer 23 have a width (width in the Y-axis direction) required in the height direction of the MR element 2 and leave a strip portion extending in the Z-axis direction by a length corresponding to the width w. , Non-magnetic metal layer 24, free layer 25, tunnel barrier layer 26, pinned layer 27, pinned layer 28, upper metal layer 2
9 and the insulating layer 30 'are removed. In this example, the second ion milling completely removes the lower metal layer 22,
The lower electrode 21 is stopped at a position where it is hardly removed. However, the second ion milling may be stopped at any position from the position directly below the free layer 25 to the position directly below the lower metal layer 22 as long as the free layer 25 is completely removed. Good. When the lower electrode 21 also serves as the lower magnetic shield, the second ion milling may be stopped at the position where the lower electrode 21 is over-etched. Further, the lower electrode 21
When the two are separated without also serving as the lower magnetic shield, the second ion milling may be stopped at a position where the lower magnetic shield is over-etched. And
After the second ion milling, the insulating layer 30 is formed on the portion removed by the second ion milling using the lift-off method.
Forming an insulating layer 30 ″ which will be the remaining portion (FIG. 9).

After that, the upper electrode 31 is formed on the wafer 101 in the state shown in FIG. 9 by a plating method or the like (FIG. 1).
0).

Finally, the gap layer 38, the coil layer 37,
Forming an insulating layer 39, an upper magnetic layer 36 and a protective film 40,
Further, bonding pads 5a to 5d and the like are formed. This completes the wafer process.

Next, the magnetic head is completed through known processes for the wafer which has been completed after the wafer process. Briefly, each bar (bar-shaped magnetic head assembly) in which a plurality of magnetic head portions are arranged in a line on a substrate is cut out from the wafer. Then, in order to set the throat height, MR height, etc. for this bar, the A
Lapping treatment (polishing) is performed on the BS side. Next, ABS
The protective film 4 is formed on the side, and the rails 11 and 12 are further formed by etching or the like. Finally, it is cut by machining to separate the bars into individual magnetic heads. This allows
The magnetic head according to the first embodiment is completed.

A magnetic head of a comparative example to be compared with the magnetic head according to this embodiment will be described with reference to FIGS. 11 to 13.

FIG. 11 is a schematic sectional view showing a main part of a magnetic head according to this comparative example. FIG. 12 is another schematic cross-sectional view showing the main part of the magnetic head according to this comparative example. FIG. 13 is a schematic view taken along the line GG ′ in FIG. Figure 11
13 to 13 correspond to FIGS. 4 to 6, respectively.
11 to 13, the same or corresponding elements as those in FIGS. 4 to 6 are designated by the same reference numerals, and the duplicated description thereof will be omitted.

The magnetic head according to this comparative example is the same as the magnetic head according to the first embodiment described in the above-mentioned article and Japanese Patent Laid-Open No.
It is modified in accordance with the structure disclosed in Japanese Patent Publication No. 1-68759. That is, in the magnetic head shown in FIGS. 11 to 13, all the layers 22 to 29 are collectively ion-milled with respect to the end faces on any side, and the tunnel barrier layer 26, the pinned layer 27, the pinned layer 28, and the upper metal layer. Two
9 is T that substantially overlaps with the effective area (area of TW × h)
It is formed only in the region of W1 × h1. The width difference TW1-TW in the Z-axis direction (track width direction) is due to the tapered surface due to milling similarly to the width difference h1-h in the Y-axis direction, and it can be substantially said that TW1 = TW. . Except for the points described above, this comparative example is exactly the same as the first embodiment.

In contrast to this comparative example, in the first embodiment, as described above, the antiferromagnetic layer 23 and the nonmagnetic metal layer 2 are used.
4 and the free layer 25 are not only a region that substantially overlaps with the effective region (TW × h region) but also a region (w that extends from the region to both sides in the Z-axis direction (track width direction)).
Xh1≈w × h). Therefore, according to the present embodiment, even if the effective track width TW is narrower than that of the comparative example according to the prior art (for example, 0.5 μ
m or less or 0.2 μm or less), the influence of the demagnetizing field of the free layer 25 is mitigated, and a sufficient bias magnetic field for suppressing Barkhausen noise is obtained in the free layer 25.

[Second Embodiment]

FIG. 14 is a schematic sectional view showing a main part of a magnetic head according to the second embodiment of the present invention. Figure 15
FIG. 6 is another schematic cross-sectional view showing the main part of this magnetic head. FIG. 16 is a schematic view taken along the line HH ′ in FIG.
14 to 16 correspond to FIGS. 4 to 6, respectively. 14 to 16, elements that are the same as or correspond to the elements in FIGS. 4 to 6 are given the same reference numerals, and duplicate descriptions thereof will be omitted.

The magnetic head according to the second embodiment differs from the magnetic head according to the first embodiment only in the points described below.

In the first embodiment, the free layer 25 is formed below the tunnel barrier layer 26, and
Whereas the pinned layer 27 is formed on the upper side of the tunnel barrier layer 26, in the second embodiment, conversely, the free layer 25 (25 ′, 2 ′ is formed on the upper side of the tunnel barrier layer 26).
5 ″) and the pinned layer 27 is formed below the tunnel barrier layer 26. Accordingly, in the second embodiment, the lower electrode 21 is provided between the electrodes 21 and 31.
In order from the side, the lower metal layer 22, the pinned layer 28, and the pinned layer 2
7, tunnel barrier layer 26, free layer 25 (25 ', 2
5 ″), the non-magnetic metal layer 24, the antiferromagnetic layer 23, and the upper metal layer (cap layer) 29 are stacked. In the second embodiment, the free layer 25 includes the lower layer 25 ′ and the upper layer. Two
5 ".

In the second embodiment, only the area where the layers 22, 28, 27, 26, 25 'substantially overlap the effective area (area of TW × h) in a plan view seen from the X-axis direction. Formed, layers 25 ″, 24, 23, 29 are substantially w × h1
It is formed in a region of (≈w × h). TW, h, h
The meanings of 1 and w are the same as in the case of the first embodiment. The lower layer 25 ′ of the free layer 25 is formed only in the region of TW × h, and the upper layer 25 ″ of the free layer 25 is formed in the region of w × h1.
It is formed in the region of × h1. In this way, the free layer 25 is divided into the lower layer 25 ′ and the upper layer 25 ″, and the formation regions of both are changed to prevent the tunnel barrier layer 26 from being exposed before the second ion milling described later. The lower layer 25 ′ and the upper layer 25 ″ may be formed of the same material or different materials.

Next, an example of a method of manufacturing the magnetic head according to the second embodiment will be described.

First, a wafer process is performed. That is, a wafer 101 such as Al ₂ O ₃ —TiC or SiC to be the base 15 is prepared, and the wafer 1 is formed by using a thin film forming technique or the like.
Each of the layers described above is formed in the formation region of a large number of magnetic heads in a matrix on 01 so as to have the above-described structure.

The outline of this wafer process will be described with reference to FIGS. 17 to 21 are diagrams schematically showing each step constituting the wafer step.
7 (a), FIG. 18 (a), FIG. 19 (a), and FIG. 20 (a)
21A and FIG. 21A are schematic plan views. FIG. 17
17B is a schematic sectional view taken along the line JK in FIG. 17A, FIG. 18B is a schematic sectional view taken along the line JK in FIG. 18A, and FIG. ) Is a schematic sectional view taken along the line JK in FIG. 19A, FIG. 20B is a schematic sectional view taken along the line LM in FIG. 20A, and FIG. Figure 21
It is a schematic sectional drawing along the JK line in (a). In addition,
18 (a), 19 (a), 20 (a) and 21.
In (a), TW indicates the track width defined by the TMR element 2, w indicates the width of the antiferromagnetic layer 23, the nonmagnetic metal layer 24, and the free layer 25 in the Z-axis direction (track width direction). Correspond to the same symbols in FIG. 16, respectively.

In the wafer process, first, the underlying layer 16, the lower electrode 21, the lower metal layer 22, the pinned layer 28, the pinned layer 27, the tunnel barrier layer 26, and the lower layer 25 ′ of the free layer 25 are sequentially laminated on the wafer 101. (Fig. 17). At this time, the lower electrode 21 is formed by, for example, a plating method, and the other layers are formed by, for example, a sputtering method.

Next, by the first ion milling, the lower metal layer 22, the pinned layer 28, the pinned layer 27, the tunnel barrier layer 26, and the free layer are left, leaving a strip-shaped portion extending in the Y-axis direction corresponding to the track width TW. The lower layer 25 'of 25 is removed. In this example, the first ion milling is performed on the lower metal layer 2
2 is completely removed, but the lower electrode 21 is stopped at a position where it is hardly removed. However, in the first ion milling, for example, if the lower layer 25 ′ of the free layer 25 is completely removed, at any position from the position immediately below the lower layer 25 ′ to the position immediately below the lower metal layer 22, You may stop it. When the lower electrode 21 is also used as the lower magnetic shield, the first ion milling may be stopped at the position where the lower electrode 21 is over-etched. Further, when the lower electrode 21 and the lower magnetic shield are not used together and are separated, the first ion milling may be stopped at a position where the lower magnetic shield is over-etched. Then, after the first ion milling, an insulating layer 30 ′ to be a part of the insulating layer 30 is formed in the portion removed by the first ion milling using the lift-off method (FIG. 18).

Next, the upper layer 25 ″ of the free layer 25, the nonmagnetic metal layer 24, the antiferromagnetic layer 23 and the upper metal layer 29 are formed.
The layers are sequentially stacked by the sputtering method or the like (FIG. 19).

After that, by the second ion milling, T
The lower metal layer 22 and the pinned layer 2 have a width (width in the Y-axis direction) required in the height direction of the MR element 2 and leave a strip-shaped portion extending in the Z-axis direction by a length corresponding to the width w.
8, pinned layer 27, tunnel barrier layer 26, free layer 2
5. The lower layer 25 ′ of 5, the upper layer 25 ″ of the free layer 25, the nonmagnetic metal layer 24, the antiferromagnetic layer 23, the upper metal layer 29, and the insulating layer 30 ′ are removed. In this example, the second ion milling is performed. The lower metal layer 22 is completely removed, but the lower electrode 2
Stop at a position where 1 is hardly removed. However, the second ion milling may be performed, for example, at any position from a position immediately below the lower layer 25 ′ to a position directly below the lower metal layer 22 as long as the lower layer 25 ′ of the free layer 25 is completely removed. You may stop it. When the lower electrode 21 also serves as the lower magnetic shield, the second ion milling may be stopped at the position where the lower electrode 21 is over-etched. Further, the lower electrode 21
When the two are separated without also serving as the lower magnetic shield, the second ion milling may be stopped at a position where the lower magnetic shield is over-etched. And
After the second ion milling, the insulating layer 30 is formed on the portion removed by the second ion milling using the lift-off method.
Forming an insulating layer 30 ″ which will be the remaining portion of the (FIG. 2
0).

After that, the wafer 101 in the state shown in FIG.
An upper electrode 31 is formed on the upper surface by a plating method or the like (see FIG. 2).
1).

Finally, the gap layer 38, the coil layer 37,
Forming an insulating layer 39, an upper magnetic layer 36 and a protective film 40,
Further, bonding pads 5a to 5d and the like are formed. This completes the wafer process.

Next, the magnetic head is completed through known processes for the wafer which has been completed after the wafer process. Briefly, each bar (bar-shaped magnetic head assembly) in which a plurality of magnetic head portions are arranged in a line on a substrate is cut out from the wafer. Then, in order to set the throat height, MR height, etc. for this bar, the A
Lapping treatment (polishing) is performed on the BS side. Next, ABS
The protective film 4 is formed on the side, and the rails 11 and 12 are further formed by etching or the like. Finally, it is cut by machining to separate the bars into individual magnetic heads. This allows
The magnetic head according to the second embodiment is completed.

Also in the second embodiment, as in the first embodiment, the antiferromagnetic layer 23 and the nonmagnetic metal layer 2 are formed.
4 and the free layer 25 are not only a region that substantially overlaps with the effective region (TW × h region) but also a region (w that extends from the region to both sides in the Z-axis direction (track width direction)).
Xh1≈w × h). Therefore, the second
According to this embodiment, the same advantages as those of the first embodiment can be obtained.

[Third Embodiment]

FIG. 22 is a schematic perspective view showing the structure of the main part of a magnetic disk device according to the third embodiment of the present invention.

The magnetic disk device according to the third embodiment includes a magnetic disk 71 rotatably provided around an axis 70, a magnetic head 72 for recording and reproducing information on the magnetic disk 71, and a magnetic disk. An assembly carriage device 73 for positioning the head 72 on the track of the magnetic disk 71.

The assembly carriage device 73 includes a shaft 74.
A carriage 75 rotatable about the center of the carriage 75 and a voice coil motor (V
It is mainly composed of an actuator 76 made of CM).

A base of a plurality of drive arms 77 stacked in the direction of the shaft 74 is attached to the carriage 75, and the magnetic head 7 is attached to the tip of each drive arm 77.
A head suspension assembly 78 carrying 2 is fixed. Each head suspension assembly 7
8 is a drive arm 7 so that the magnetic head 72 at the tip thereof faces the surface of each magnetic disk 71.
It is provided at the tip of 7.

In the third embodiment, any one of the magnetic heads according to the first and second embodiments described above is mounted as the magnetic head 72. Therefore, the third
According to the embodiment, it is possible to increase the recording density.

[0093]

EXAMPLES Regarding the magnetic heads of Examples 1 to 3 having the same configuration as the magnetic head according to the first embodiment and the magnetic head of the comparative example, Laudau, which is a typical method of micromagnetics simulation, was used. -Lifshits-
Head output was calculated by Gilbert (LLG) simulation.

The difference between Examples 1 to 3 and Comparative Example is that the antiferromagnetic layer 23, the nonmagnetic metal layer 24 and the free layer 2 are different.
5 is the width w in the Z-axis direction (track width direction) (see FIG. 6), and the other simulation conditions were exactly the same for Examples 1 to 3 and Comparative Example. The main parameters of the simulation will be described below.

Lower electrode 21 which also serves as a lower magnetic shield
For the upper electrode 31 which also serves as the upper magnetic shield, the mirroring method was adopted. The thickness between the lower electrode 21 and the upper electrode 31 was 700Å. The total thickness of the lower metal layer 22, the antiferromagnetic layer 23, and the nonmagnetic metal layer 24 is 33.
It was 0Å. The total thickness of the tunnel barrier layer 26, the pinned layer 27, the pinned layer 28, and the upper metal layer 29 is 330.
Å Therefore, the thickness of the free layer 25 is 40Å
(= 700Å−330Å−330Å). The thickness of the tunnel barrier layer 26 was 5Å. The insulating layer 30 is assumed to be a complete insulator layer. This tunnel magnetoresistive element (layer 2
5, 26, 27), the resistance per 1 μm ² is 5Ω,
The MR ratio was set to 15%. The exchange coupling magnetic field Hex applied to the free layer 25 was 100 Oe.

The antiferromagnetic layer 23, the non-magnetic metal layer 24, and the free layer 25 have exactly the same size in plan view as seen from the X-axis direction and are completely overlapped with each other. The width w in the width direction) was the same for each of Examples 1 to 3 and Comparative Example. In the comparative example, w =
0.17 μm, w = 0.26 μm in Example 1, w = 0.34 μm in Example 2, w = 0.43 μm in Example 3
m.

The layers 26 to 29 have the same size in plan view as seen from the X-axis direction and are completely overlapped with each other, and the width (track width) TW in the Z-axis direction is 0.17.
μm. Therefore, w = TW in the comparative example (that is, TW1 = TW in FIG. 13), and w> TW in Examples 1 to 3.

The width h1 of the antiferromagnetic layer 23, the nonmagnetic metal layer 24, and the free layer 25 in the Y-axis direction is equal to the width h of the layers 26 to 29 in the Y-axis direction, and the width h is 0.10 μm.
And The layers 23 to 29 were assumed to be completely overlapped in the Y-axis direction. Further, the centers of the widths of the layers 23 to 25 in the Y-axis direction are set to coincide with the centers of the widths of the layers 26 to 29 in the Y-axis direction.

Regarding the simulation conditions for the magnetic recording medium, the value of the product Brt of the residual magnetic flux density Br and the total film thickness t of the magnetic film is 50 Gμm, and the layer film thickness t is 100.
Å, the coercive force Hc of the magnetic film was 5000 Oe, the track width was 0.19 μm, the magnetic spacing was 180 Å, and the lead gap was 700 Å. The free layer 25 was set at the center of the read gap.

As a result of simulation under the above-described simulation conditions, transfer curves shown in FIGS. 23 to 26 were obtained for the comparative example and Examples 1 to 3. From this transfer curve, the head output (Output (mV / μm)) defined by the following equation 1 and the asymmetry (Asymmetry (%)) defined by the following equation 2 were calculated. The results are shown in Table 1 below. Table 1 shows the ratio of w to h, w / h, and the output of Comparative Example 1.
Head output normalized by (mV / μm) (Normalized O
utput) is also shown.

[0101]

[Equation 1] Output = {| V (Brt = + 50) | + | V (Brt = -50) |} / (0.17u
m) [mV / μm]

[0102]

[Equation 2] Asym. = {-| V (Brt = + 50) | + | V (Brt = -50) |} / {| V (Brt
= + 50) | + | V (Brt = -50) |} X100 [%]

[0103]

[Table 1]

Comparative Example (w = 0.17 μm, that is, w
= TW), the transfer curve has a large hysteresis as shown in FIG. 23, and a sufficient bias magnetic field is not applied to the free layer 25. Example 1 (w =
In the case of 0.26 μm), as shown in FIG. 24, the transfer curve has only a small hysteresis, and a fairly good bias magnetic field is applied to the free layer 25.
Example 2 (w = 0.34 μm) and Example 3 (w = 0.
In the case of 43 μm), the transfer curve is closed and a sufficient bias magnetic field that can be used as a reproducing head is applied to the free layer 25. Further, as can be seen from Table 1, in Examples 1 to 3, the asymmetry (Asymmetry (%)) was also significantly improved as compared with the comparative example. From the results in Table 1, if the ratio w / h is 2.0 or more,
A bias magnetic field is applied to the free layer 25 fairly well,
When the ratio w / h is 2.6 or more, the bias magnetic field is given to the free layer 25 fairly well, and when the ratio w / h is 3.4 or more, the bias magnetic field is sufficiently given to the free layer 25. I understand.

It is considered that these results are due to the demagnetizing field of the free layer becoming weaker as w / h becomes larger.

The above is the simulation result of the magnetic head having the same structure as that of the first embodiment, but the simulation result of the magnetic head having the same structure as that of the second embodiment is also obtained. , Will be the same.

Although the embodiments and examples of the present invention have been described above, the present invention is not limited to these examples.

For example, although the above-described embodiment is an example in which the present invention is applied to the TMR head, the present invention can also be applied to, for example, a CPP-GMR head.
In this case, for example, in each of the above-described embodiments, the tunnel barrier layer 26 may be replaced with a nonmagnetic layer of Cu, Au, Ag, or the like. The present invention also provides a CIP
It can also be applied to a magnetic head having a structure.

Further, in the above-mentioned embodiment, the example in which the magnetoresistive effect element according to the present invention is used for the magnetic head is given, but the magnetoresistive effect element according to the present invention can be applied to various other uses. it can.

[0110]

As described above, according to the present invention,
While having a structure in which a magnetic domain control film that gives a bias magnetic field to the free layer is laminated on the magnetoresistive effect layer, obtain a sufficient bias magnetic field in the free layer to suppress Barkhausen noise even if the effective track width is narrow. It is possible to provide a magnetoresistive effect element capable of

Further, according to the present invention, by using such a magnetoresistive effect element, it is possible to provide a magnetic head, a head suspension assembly and a magnetic disk device which are compatible with high recording density.

[Brief description of drawings]

FIG. 1 is a schematic perspective view schematically showing a magnetic head according to a first embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view schematically showing a TMR element 2 and an inductive magnetic conversion element 3 of the magnetic head shown in FIG.

FIG. 3 is a schematic view taken along the line A-A ′ in FIG.

FIG. 4 is an enlarged view in which the vicinity of the TMR element in FIG. 2 is further enlarged.

5 is an enlarged view in which the vicinity of the TMR element in FIG. 3 is further enlarged.

6 is a view taken along the line B-B ′ in FIG.

FIG. 7 is a diagram schematically showing one step constituting a wafer step in the method of manufacturing the magnetic head shown in FIGS.

FIG. 8 is a diagram schematically showing another step constituting the wafer step in the method of manufacturing the magnetic head shown in FIGS.

9 is a diagram schematically showing still another step constituting the wafer step in the method of manufacturing the magnetic head shown in FIGS.

10 is a diagram schematically showing still another step constituting the wafer step in the method of manufacturing the magnetic head shown in FIGS.

FIG. 11 is a schematic sectional view showing a main part of a magnetic head according to a comparative example.

12 is another schematic cross-sectional view showing the main parts of the magnetic head according to the comparative example shown in FIG.

FIG. 13 is a schematic view taken along the arrow G-G ′ in FIG. 12.

FIG. 14 is a schematic sectional view showing a main part of a magnetic head according to a second embodiment of the invention.

FIG. 15 is another schematic cross-sectional view showing the main parts of the magnetic head according to the second embodiment of the invention.

16 is a schematic view taken along the line H-H 'in FIG.

FIG. 17 is a diagram schematically showing one step constituting a wafer step in the magnetic head manufacturing method according to the second embodiment of the present invention.

FIG. 18 is a diagram schematically showing another step constituting the wafer step in the method of manufacturing the magnetic head according to the second embodiment of the invention.

FIG. 19 is a diagram schematically showing still another step constituting the wafer step in the method of manufacturing the magnetic head according to the second embodiment of the invention.

FIG. 20 is a diagram schematically showing still another step constituting the wafer step in the method of manufacturing the magnetic head according to the second embodiment of the invention.

FIG. 21 is a diagram schematically showing still another step constituting the wafer step in the method of manufacturing the magnetic head according to the second embodiment of the invention.

FIG. 22 is a schematic perspective view showing a configuration of a main part of a magnetic disk device according to a third embodiment of the present invention.

FIG. 23 is a diagram showing a transfer curve of a comparative example.

FIG. 24 is a diagram showing a transfer curve of Example 1.

FIG. 25 is a diagram showing a transfer curve of Example 2;

FIG. 26 is a diagram showing a transfer curve of Example 3;

[Explanation of symbols]

1 slider 2 TMR element 3 Induction type magnetic conversion element 21 Lower electrode 22 Lower metal layer 23 Antiferromagnetic layer 24 Non-magnetic metal layer 25 free class 26 Tunnel barrier layer 27 pinned layer 28 pin layers 29 Upper metal layer 30 insulating layer 31 upper electrode

Claims (11)

[Claims] 1. A magnetoresistive effect layer formed on one surface side of a substrate and including a free layer, and a magnetoresistive layer formed on one surface side of the free layer on the same side of the substrate as the free layer. And an antiferromagnetic layer that applies a bias magnetic field mainly in a predetermined direction of the film surface direction of the free layer, and an overlapping region of the free layer and the antiferromagnetic layer is used for magnetic detection in the magnetoresistive effect layer. A region that substantially overlaps with an effective region in the film surface direction that effectively participates, and a region that is continuous from this region and does not substantially overlap with the effective region, and the region that does not substantially overlap is the substantially A magnetoresistive effect element including a region on at least one side in the predetermined direction with respect to a region overlapping with the. 2. The magnetoresistive effect element according to claim 1, further comprising a non-magnetic metal layer interposed between the free layer and the antiferromagnetic layer. 3. The magnetoresistive effect element according to claim 1, wherein the region that does not substantially overlap includes regions on both sides of the substantially overlap region in the predetermined direction. 4. The center of the width of the overlapping region of the free layer and the antiferromagnetic layer in the predetermined direction is located near the center of the width of the effective region in the predetermined direction. 3. The magnetoresistive element according to item 3. 5. The width of the overlapping region of the free layer and the antiferromagnetic layer in the direction orthogonal to the predetermined direction is substantially the same as the width of the effective region in the direction orthogonal to the predetermined direction. The magnetoresistive effect element according to any one of claims 1 to 4, characterized in that. 6. The ratio of the width in the predetermined direction to the width in the direction orthogonal to the predetermined direction of the overlapping region of the free layer and the antiferromagnetic layer is 2 or more. 6. The magnetoresistive effect element according to any one of 1 to 5. 7. A first electrode formed between the base and one of the magnetoresistive effect layer and the antiferromagnetic layer formed closest to the base, and the magnetoresistive effect layer. And a second electrode formed on the side of the antiferromagnetic layer that is the most opposite to the side of the base, and the second electrode formed on the side opposite to the side of the base. A tunnel barrier layer or a non-magnetic layer formed on the other surface side of the free layer, and a pinned layer formed on a side of the tunnel barrier layer or the non-magnetic layer opposite to the free layer; A pinned layer formed on a side of the pinned layer opposite to the tunnel barrier layer or the non-magnetic layer, wherein the effective region includes a film surface between the first electrode and the second electrode. It is a region in the film surface direction where the current flows in a substantially vertical direction. The element according to any one of claims 1 to 6, symptoms. 8. The magnetoresistive effect element according to claim 7, wherein at least one of the pinned layer and the pinned layer is formed only in a region substantially overlapping the effective region. 9. A magnetoresistive effect element comprising: a base; and a magnetoresistive effect element supported by the base, wherein the magnetoresistive effect element is claim 1.
A magnetic head comprising the magnetoresistive effect element according to any one of items 1 to 8. 10. A head suspension assembly comprising: the magnetic head according to claim 9; and a suspension mounted near the tip of the magnetic head for supporting the magnetic head. 11. The head suspension assembly according to claim 10, and an arm portion that supports the assembly.
A magnetic disk device comprising: an actuator that moves the arm portion to position a magnetic head.