JP2002203304A - Tmr head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a TMR head for a magnetic recording system, capable of preventing problems including short-circuiting between both ends of a tunnel barrier layer, the corrosion of a tunnel barrier layer or an antiferromagnetic substance, and the like because of the edge of a magnetic tunnel junction element exposed on an ABS surface. SOLUTION: The TMR head is provided with a first conductive lead layer 104 formed on a substrate, and a detection ferromagnetic layer 105, an insulating tunnel barrier layer 107, a fixed ferromagnetic layer 108, an antiferromagnetic layer 109 and a second conductive lead layer 111 which are sequentially formed on the first conductive lead layer 104. A medium opposite surface on a TMR element including the detection ferromagnetic layer 105, the insulating tunnel barrier layer 107, the fixed ferromagnetic layer 108 and the antiferromagnetic layer 109 is formed to be inclined to the inside of a head main body more than the medium opposite surface 2 of the first conductive lead layer 104.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magneto-resistance (Magneto-Resistivity) head (hereinafter referred to as "MR" head) for reading magnetic recording data, and a tunneling magneto-resistance (hereinafter referred to as "TMR"). .) The present invention relates to a TMR head using an element.

[0002]

2. Description of the Related Art Generally, a magnetic tunnel junction device is composed of two ferromagnetic layers separated by a thin insulating tunnel barrier layer, and utilizes a magnetic polarization electron tunnel phenomenon. Therefore, one of the two ferromagnetic layers has a higher coercivity than the other ferromagnetic layer,
It will have a higher saturation field in one direction.

Further, an insulating tunnel barrier layer in a magnetic tunnel junction element is thin enough (0.5 nm) between the ferromagnetic layers to cause the above-mentioned magnetic polarization electron tunneling phenomenon.
２2 nm).

[0004] Such a magnetic tunnel junction element is connected to a tunnel magnetoresistive head (hereinafter referred to as "TM") utilizing its high sensitivity.
R head ". ) Has been widely studied.

[0005]

In the TMR head, the sensing ferromagnetic layer, the tunnel barrier layer, and the fixed ferromagnetic layer are all located on the sensing surface of the head, that is, the air bearing when the TMR head is used in a magnetic recording disk drive. The slider has an exposed edge on an air bearing surface (hereinafter referred to as “ABS”) of the slider. Therefore, when the ABS is formed by wrapping the TMR head, the smear of the material from the free ferromagnetic layer and the fixed ferromagnetic layer in the ABS may cause a short circuit between both ends of the tunnel barrier layer. There was a point.

[0006] Many antiferromagnets used to pin the magnetic moment of the pinned ferromagnetic layer also contain manganese (Mn), which can cause corrosion during the ABS lapping process. Sex is also left.

Further, since the tunnel barrier layer is generally formed of aluminum oxide, the same applies to A
The potential remains for corrosion during the BS wrapping process.

In order to solve the above problem, in order to prevent the above-mentioned smear and corrosion, Japanese Patent Application Laid-Open No. H11-213349 discloses a method in which a free ferromagnetic layer is shared with a magnetic flux guide.
A method is disclosed in which the edges of the tunnel barrier layer, the fixed ferromagnetic layer, and the antiferromagnetic layer are exposed from the BS surface and receded from the ABS surface.

However, Japanese Patent Application Laid-Open No. H11-213349 discloses
In the method disclosed in Japanese Patent Application Laid-Open Publication No. H11-157, it is difficult to make the heights of the tunnel barrier layer and the ABS-side insulating layer uniform, so that the flatness of the free ferromagnetic layer cannot be obtained, A new problem arises in that the output decreases, or when the magnetic flux guide is lengthened, the magnetic flux density in the magnetic flux guide is attenuated, so that the reproduction output decreases.

In view of the above problems, the present invention has a short circuit between both ends of a tunnel barrier layer due to having an edge of a magnetic tunnel junction element exposed on an ABS surface, corrosion of a tunnel barrier layer and an antiferromagnetic material, and the like. It is an object of the present invention to provide a TMR head for a magnetic recording system in which the problem described above does not occur.

[0011]

In order to achieve the above object, a TMR head according to the present invention is aligned substantially parallel to the surface of a recording medium when detecting magnetically recorded data. A TMR head having a detection surface and detecting data magnetically recorded on a recording medium when connected to a sense circuit, the substrate having an edge forming a part of the detection surface; A first conductive lead layer formed on a substrate, a fixed ferromagnetic layer having a fixed magnetization direction even when an applied magnetic field from a recording medium is present,
When formed on the first conductive lead layer and there is no applied magnetic field from the recording medium, the magnetization direction is oriented substantially perpendicular to the magnetization direction of the fixed ferromagnetic layer, and the applied magnetic field from the recording medium is present. In this case, the fixed ferromagnetic layer, whose magnetization direction can be freely set, and the fixed ferromagnetic layer and the detection ferromagnetic layer are disposed between and in contact with the fixed ferromagnetic layer. An insulating tunnel barrier layer for generating a tunnel current in a direction substantially perpendicular to the ferromagnetic layer; and a second conductive lead layer formed on the fixed ferromagnetic layer. And a medium facing surface of the TMR element including the fixed ferromagnetic layer and the medium facing surface of the first conductive lead layer is formed to be inclined inwardly of the head body.

[0012] With this configuration, the medium facing surface of the TMR element is recessed from the medium facing surface of the first conductive lead layer, that is, the ABS surface.
It is possible to suppress a short circuit between both ends of the tunnel barrier layer and corrosion of the antiferromagnetic layer, which may occur when lapping is performed from the surface side.

In the TMR head according to the present invention, it is preferable that the inclination angle θ satisfies 30 ° ≦ θ ≦ 50 ° with the medium facing surface of the first conductive lead layer. If θ is smaller than 30 °, the rate of occurrence of defective reproduction output sharply increases, and if θ is larger than 50 °, the MR ratio decreases.

Next, in order to achieve the above object, a TMR head according to the present invention has a detection surface which is positioned substantially parallel to the surface of a recording medium when detecting magnetically recorded data. A TMR head for detecting data magnetically recorded on a recording medium when connected to a sense circuit, comprising: a substrate having an edge forming a part of a detection surface; The first conductive lead layer thus formed, a fixed ferromagnetic layer having a fixed magnetization direction even when an applied magnetic field from a recording medium is present, and a contact with the fixed ferromagnetic layer. An antiferromagnetic layer for fixing the magnetization direction of the fixed ferromagnetic layer when an applied magnetic field from the recording medium is present, and an antiferromagnetic layer formed on the first conductive lead layer;
When there is no applied magnetic field from the recording medium, the magnetization direction is oriented substantially perpendicular to the magnetization direction of the fixed ferromagnetic layer. When there is an applied magnetic field from the recording medium, the magnetization direction can be set freely. The ferromagnetic layer is disposed between the fixed ferromagnetic layer and the sensing ferromagnetic layer in contact with the fixed magnetic layer and the sensing ferromagnetic layer, and is substantially perpendicular to the fixed ferromagnetic layer and the sensing ferromagnetic layer. And a second conductive lead layer formed on the fixed ferromagnetic layer, wherein the sensing ferromagnetic layer, the insulating tunnel barrier layer, the fixed ferromagnetic layer, and the antiferromagnetic layer are formed. The medium facing surface of the included TMR element is formed so as to be inclined more inward of the head body than the medium facing surface of the first conductive lead layer.

According to this structure, the medium facing surface of the TMR element is recessed from the medium facing surface of the first conductive lead layer, that is, the ABS surface.
It is possible to suppress a short circuit between both ends of the tunnel barrier layer and corrosion of the antiferromagnetic layer which may occur when lapping is performed from the S surface side.

In the TMR head according to the present invention, it is preferable that the inclination angle θ satisfies 30 ° ≦ θ ≦ 50 ° with the medium facing surface in the first conductive lead layer. If θ is smaller than 30 °, the rate of occurrence of defective reproduction output sharply increases, and if θ is larger than 50 °, the MR ratio decreases.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a TMR head according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view of a TMR head according to an embodiment of the present invention, and FIG.
It is a front view of an R head.

First, FIG. 1 shows a case where information recorded on the recording medium 1 is read, and the medium facing surface 2 (ABS surface in the case of a magnetic recording disk drive) is positioned substantially in parallel with the recording medium 1. It is sectional drawing in the case of having done. FIG.
In the figure, 101 indicates a substrate, 102 indicates a first magnetic shield layer, 103 indicates an insulating layer, and 104 indicates a lower lead layer.

1 and 2, reference numeral 105 denotes a sensing ferromagnetic layer, 106 denotes a hard magnetic layer, 107 denotes a tunnel barrier layer, 108 denotes a fixed ferromagnetic layer, 109 denotes an antiferromagnetic layer, 110 is an insulator, 111 is an upper lead layer,
Each is shown.

The sensing ferromagnetic layer 105 is formed on the lower lead layer 10.
4, when the applied magnetic field is not applied from the recording medium, the magnetization direction is oriented substantially perpendicular to the magnetization direction of the fixed ferromagnetic layer 108. When the applied magnetic field is applied from the recording medium, , Which can rotate freely.

The fixed ferromagnetic layer 108 needs to be fixed so that its magnetization direction does not change even when an applied magnetic field from a recording medium is present.

The antiferromagnetic layer 109 includes a fixed ferromagnetic layer 108
And fixing the magnetization direction of the fixed ferromagnetic layer 108 by interfacial exchange coupling along a preferred direction so that rotation is effectively prevented when an applied magnetic field from the recording medium is present, This is an essential layer in a spin valve type TMR head.

The tunnel barrier layer 107 is composed of the fixed ferromagnetic layer 1
08 and the sensing ferromagnetic layer 109, a thin insulating layer disposed in contact with the fixed ferromagnetic layer 108 and the sensing ferromagnetic layer 109. It produces a tunnel current in the vertical direction.

The TMR element includes a sensing ferromagnetic layer 105, a tunnel barrier layer 107, a fixed ferromagnetic layer 1
08, or a sensing ferromagnetic layer 105, a tunnel barrier layer 107, a fixed ferromagnetic layer 108, and an antiferromagnetic layer 109. Then, the TMR element portion forms an inclination angle θ of 30 ° or more and 50 ° or less with the medium facing surface 2.
Is characterized in that it has a structure having Reference numeral 112 denotes an insulator, and 113 denotes an upper shield layer.

FIG. 15 shows the relationship between the inclination angle θ and the rate of occurrence of a reproduction output defect that is considered to be caused by smear with respect to the inclination angle θ. As is clear from FIG. 15, the inclination angle θ
Is 30 ° or more, it is possible to suppress the occurrence rate of reproduction output failure to 20% or less. Also, 3
It is considered that the inclination angle θ is desirably equal to or greater than 30 ° since the failure occurrence rate rapidly deteriorates when the angle is equal to or less than 0 °.

FIG. 16 shows the relationship between the tilt angle θ and the MR ratio. As is clear from FIG. 16, the MR ratio increases as the inclination angle θ increases, but from 40 ° to 50 °.
30 ° which is considered to be the peak time
It can be seen from FIG. 7 that the MR ratio at 40 ° is lower by about 10%. In addition, no increase in the MR ratio is observed at more inclination angles. Therefore, it can be considered that the inclination angle θ is more preferably equal to or less than 50 °.

In FIGS. 1 and 2, the lower magnetic shield layer 102 and the upper magnetic shield layer 113 may be made of a soft magnetic material such as a Ni—Fe alloy or a Co-based amorphous. The material of the lower lead layer 104 and the upper lead layer 111 is Al, Ta, C
Various conductive materials such as u, W, Au, and Pt are conceivable.

Further, the material of the sensing ferromagnetic layer 105 and the pinned ferromagnetic layer 108 is Co (100-x) Fe
It is conceivable to use a soft magnetic material such as (x) (x is about 70). The material of the antiferromagnetic layer 109 is Fe-M
It is conceivable to use various antiferromagnetic materials such as n, Ni-Mn, Pt-Mn, and Ir-Mn.

The material of the hard magnetic layer 106 is as follows.
Co-Pt-Cr alloy, Co-Cr alloy, Co-Cr-
It is conceivable to use a ferromagnetic material having various high coercive force characteristics such as a Ta alloy. Insulating layers 103, 110, 112
It is conceivable to use an insulating material such as Al ₂ O ₃ or SiO ₂ .

Usually, the insulating layers 103, 110, 11
2. Lead layers 104 and 111, sensing ferromagnetic layer 105, fixed ferromagnetic layer 108, antiferromagnetic layer 109, and hard magnetic layer 1.
06 is formed by a high frequency or DC magnetron sputtering method.

Next, FIGS. 3 to 11 show a manufacturing process of the TMR head according to the embodiment of the present invention. Hereinafter, a method of manufacturing the TMR head according to the present embodiment will be described with reference to FIGS.

First, in FIG. 3, the non-magnetic substrate 101 (A
A first magnetic shield layer 102, an insulating layer 103, a lower lead layer 104, and a sensing ferromagnetic layer 105 are sequentially formed and stacked on (l ₂ O ₃ —TiC). Then, the laminated film is patterned into a predetermined shape by using an ion milling method.

Next, as shown in FIG. 4, a photoresist pattern is formed by a lift-off process, a hard magnetic film is formed, and then the photoresist is removed. The hard magnetic layer 106 for controlling the magnetic domain of the magnetic layer 105 is formed.

Further, as shown in FIG. 5, an oxidation process (plasma oxidation method or natural oxidation method) after Al film formation or A
After forming the tunnel barrier layer 107 by forming l ₂ O ₃ or the like, as shown in FIG. 6, the fixed ferromagnetic layer 108 and the antiferromagnetic layer 109 are formed in this order, and then an etching method is used. To form a desired shape.

Next, a TMR element portion is formed by forming an inclination with the medium facing surface 2 as shown in FIG. 7 so as to have an inclination angle θ of 30 ° or more and 50 ° or less by ion milling or the like. .

Then, as shown in FIG. 8, after filling the TMR element with an insulator, the antiferromagnetic layer 10
A flattening process is performed until 9 appears, a lead film is formed as shown in FIG. 9, and patterning and etching are performed to form an upper lead layer 111.

Next, as shown in FIG. 10, the upper lead layer 111 is covered with an insulator to perform a flattening process, and as shown in FIG. 11, an upper shield layer 113 serving also as a magnetic yoke is formed on the insulator. A film is formed.

By performing such a manufacturing process, a TMR head is formed. Actually, FIG.
As shown in the figure, the upper shield layer 11 of the TMR element 205
By forming the coil 208 and the upper core 209 on 3, a recording inductive head is configured.

As described above, according to the present embodiment, TM
The medium facing surface of the R element is 3 ° from the medium facing surface of the head body.
The tunnel barrier layer 107, the fixed ferromagnetic layer 108, and the antiferromagnetic layer 109 are formed so as to recede from the inclined opposing surface (ABS surface) 2 so as to have an inclination angle θ of 0 ° or more and 50 ° or less. In addition, it is possible to suppress a short circuit between both ends of the tunnel barrier layer 107 and corrosion of the antiferromagnetic layer 109 which occur at the time of ABS lapping.

Further, as shown in FIG.
14, a fixed ferromagnetic layer 108, a tunnel barrier layer 107, and a sensing ferromagnetic layer 105 are formed in this order.
In the case where the antiferromagnetic layer 109, the fixed ferromagnetic layer 108, the tunnel barrier layer 107, and the sensing ferromagnetic layer 105 are formed in this order on the substrate 101 as shown in FIG. It may be formed by reversing. However, in these cases, the inclination angle θ is in the opposite direction to that of the present embodiment (inclination of the medium facing surface 2 and the inclination angle −θ).

Although various structures and materials can be considered as the TMR element, it is not particularly limited in the present embodiment, and any structure and material may be used.

A nonmagnetic conductive layer is disposed between the detection ferromagnetic layer and the fixed ferromagnetic layer so as to contact the detection ferromagnetic layer and the fixed ferromagnetic layer. A CPP type (Current Perpendicular to the Plane type) GMR (Gia
Even if the TMR element is replaced with the TMR element, the same effect can be expected from the present embodiment because the effect is the same from the viewpoint of the smear suppression effect.

Further, the present invention may be applied to a read-only MR head or a composite magnetic head combined with an inductive head. The target medium is not limited to a magnetic disk.

[0044]

As described above, according to the TMR head according to the present invention, only the sensing ferromagnetic layer of the magnetoresistive element is exposed on the medium facing surface, and thus the TMR head between the two ends of the tunnel barrier layer which occurs at the time of ABS lapping. Short circuits and corrosion of the antiferromagnetic layer can be suppressed.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a TMR head according to an embodiment of the present invention.

FIG. 2 is a front view of the TMR head according to the embodiment of the present invention.

FIG. 3 is a perspective view showing main manufacturing steps of the TMR head according to the embodiment of the present invention.

FIG. 4 is a perspective view showing main manufacturing steps of the TMR head according to the embodiment of the present invention.

FIG. 5 is a perspective view showing main manufacturing steps of the TMR head according to the embodiment of the present invention.

FIG. 6 is a perspective view showing main manufacturing steps of the TMR head according to the embodiment of the present invention.

FIG. 7 is a perspective view showing main manufacturing steps of the TMR head according to the embodiment of the present invention;

FIG. 8 is a perspective view showing main manufacturing steps of the TMR head according to the embodiment of the present invention.

FIG. 9 is a perspective view showing main manufacturing steps of the TMR head according to the embodiment of the present invention.

FIG. 10 is a perspective view showing main manufacturing steps of the TMR head according to the embodiment of the present invention.

FIG. 11 is a perspective view showing main manufacturing steps of the TMR head according to the embodiment of the present invention.

FIG. 12 is a longitudinal sectional view of a TMR head according to an embodiment of the present invention.

FIG. 13 is a longitudinal sectional view of the TMR head according to the embodiment of the present invention.

FIG. 14 is a longitudinal sectional view of a TMR head according to an embodiment of the present invention.

FIG. 15 is a diagram showing a relationship between a reproduction output failure rate and an inclination angle θ.

FIG. 16 is a diagram showing a relationship between an MR ratio and an inclination angle θ;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 recording medium 2 medium facing surface (ABS surface) 101 substrate 102 first magnetic shield layer 103, 110, 112 insulating layer 104 lower lead layer 105 sensing ferromagnetic layer 106 hard magnetic layer 107 tunnel barrier layer 108 fixed ferromagnetic layer 109 Ferromagnetic layer 111 Upper lead layer 113 Upper shield layer 205 TMR element 208 Coil 209 Upper core

Claims (4)

[Claims] 1. A recording device comprising: a detection surface which is positioned substantially parallel to a surface of a recording medium when detecting magnetically recorded data; T to detect magnetically recorded data on
An MR head, comprising: a substrate having an edge forming a part of a detection surface; a first conductive lead layer formed on the substrate; and a magnetic field applied from the recording medium. Also, a fixed ferromagnetic layer having a fixed magnetization direction, and formed on the first conductive lead layer, and when there is no applied magnetic field from the recording medium, the magnetization direction is the same as the magnetization direction of the fixed ferromagnetic layer. When the applied magnetic field from the recording medium is present, the sensing ferromagnetic layer can freely set the magnetization direction, and the sensing ferromagnetic layer is disposed between the fixed ferromagnetic layer and the sensing ferromagnetic layer. An insulating tunnel barrier layer disposed in contact with the fixed magnetic layer and the sensing ferromagnetic layer to generate a tunnel current in a direction substantially perpendicular to the fixed ferromagnetic layer and the sensing ferromagnetic layer; The first layer formed on the magnetic layer Wherein the medium facing surface of the TMR element including the sensing ferromagnetic layer, the insulating tunnel barrier layer, and the fixed ferromagnetic layer is closer to the medium body than the medium facing surface of the first conductive lead layer. A TMR head formed to be inclined inward. 2. The magnetoresistive head according to claim 1, wherein the inclination angle θ satisfies 30 ° ≦ θ ≦ 50 ° with the medium facing surface of the first conductive lead layer. 3. A magnetic head having a detection surface which is positioned substantially parallel to a surface of a recording medium when magnetically recorded data is detected, and which is connected to a sense circuit on the recording medium. T to detect magnetically recorded data on
An MR head, comprising: a substrate having an edge forming a part of a detection surface; a first conductive lead layer formed on the substrate; and a magnetic field applied from the recording medium. Also, a fixed ferromagnetic layer having a fixed magnetization direction, and being in contact with the fixed ferromagnetic layer and fixing the magnetization direction of the fixed ferromagnetic layer by interfacial exchange coupling when an applied magnetic field from the recording medium is present. An antiferromagnetic layer formed on the first conductive lead layer, and when there is no applied magnetic field from the recording medium, the magnetization direction is oriented substantially perpendicular to the magnetization direction of the fixed ferromagnetic layer. When there is an applied magnetic field from the recording medium, a sensing ferromagnetic layer whose magnetization direction can be freely set, and the fixed magnetic layer and the sensing ferromagnetic layer between the fixed ferromagnetic layer and the sensing ferromagnetic layer. Placed in contact with the magnetic layer An insulating tunnel barrier layer that generates a tunnel current in a direction substantially perpendicular to the fixed ferromagnetic layer and the sensing ferromagnetic layer; and a second conductive lead layer formed on the fixed ferromagnetic layer, The medium facing surface of the TMR element including the sensing ferromagnetic layer, the insulating tunnel barrier layer, the fixed ferromagnetic layer, and the antiferromagnetic layer is located inside the head body relative to the medium facing surface of the first conductive lead layer. A TMR head characterized in that it is formed so as to be inclined. 4. The magnetoresistive head according to claim 3, wherein the inclination angle θ satisfies 30 ° ≦ θ ≦ 50 ° with the medium facing surface of the first conductive lead layer.