JP2000285414A - Overlaid magnetoresistive element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent enlargement of a signal read width because of an overlaid structure and enhance a current utilization efficiency in relation to an overlaid magnetoresistive element. SOLUTION: Magnetic domain control films 7 are set at ends of a magnetoresistive film 6. A pair of terminal films 10 are set above the magnetoresistive film 6 and magnetic domain control films 7 for flowing a current to the magnetoresistive film 6. Moreover, the thickness of a part which becomes a lower part of a terminal part of an antiferromagnetic layer 5 constituting the magnetoresistive film 6 is made smaller than the thickness of a part without the terminal films 10. Detecting a current at an overlap part which is a trouble in an overlap structure is limited to a minimum, and therefore a core width and a good sensitivity to cope with a reduction in track width for a high recording density can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an overlay type magnetoresistive element, and more particularly to a magnetoresistive effect of an overlay structure used for a reproducing head (read head) of a magnetic recording device such as a hard disk drive (HDD). The present invention relates to an overlaid type magnetoresistive element characterized by a structure of an antiferromagnetic layer for improving current use efficiency in the element.

[0002]

2. Description of the Related Art In recent years, research and development of a hard disk device capable of high-density magnetic recording and the like have been rapidly advanced along with a demand for miniaturization and large capacity of a hard disk device as an external storage device of a computer. As a reproducing head used in such a hard disk drive, a high output can be obtained without depending on a relative speed between a magnetic recording medium and a magnetic head, and a magnetoresistive effect applicable to a small disk. Attention has been paid to a read-only magnetic head using an element (MR element).

With the increase in density and capacity of such read-only heads, higher sensitivity and finer readhead elements are required. From a general point of view, 40 Gbit / inc.
In order to realize a recording density of h ² (≒ 6.2 Gbit / cm ² ), the track width recorded on the magnetic recording medium is expected to be about 0.3 μm.

Here, a schematic configuration of a conventional magnetoresistive element will be described with reference to FIG. See FIG. 6 (a) Figure 6 (a) is a schematic sectional view of a conventional magnetoresistive element, on Al ₂ O ₃ -TiC substrate comprising a matrix of a slider (not shown), Al ₂ O _A lower magnetic shield layer (not shown) made of a NiFe alloy or the like is provided via _three films (not shown), and a Ta layer (not shown) is provided via an Al ₂ O ₃ film 41 serving as a lower read gap layer. NiFe free (f
ree) layer 42, CoFe free layer 43, Cu intermediate layer 4
4. CoFe pinned layer 45 and P
After a spin valve film having a laminated structure of the dPtMn antiferromagnetic layer 46 is provided and patterned into a predetermined shape, a CoCrPt hard bias film 4 is formed on both ends of the spin valve film.
7, that is, a magnetic domain control film is provided, and then a pair of Al terminal films 48 are formed. Next, an upper magnetic shield layer (not shown) made of a NiFe alloy or the like is provided again via an upper read gap layer (not shown) of Al ₂ O ₃ or the like, thereby completing the basic configuration of the read head.

In this case, if the spin valve film does not form a single magnetic domain, Barkhausen noise is generated, and the reproduction output fluctuates greatly. Therefore, a CoCrPt hard bias film 47 is provided to control the magnetic domain of the spin valve film to provide high sensitivity. It is aiming for.

The read principle of this read head is that when an external magnetic field is applied from a magnetic recording medium or the like, a ferromagnetic layer whose magnetization is not fixed, ie, a NiFe free layer 42
In addition, since the magnetization direction of the CoFe free layer 43 is freely rotated in accordance with the external magnetic field, an angle difference is generated between the magnetization direction of the ferromagnetic layer whose magnetization is fixed, that is, the CoFe pinned layer 45.

[0007] Since the scattering depending on the spin of the conduction electrons changes depending on the angle difference and the electrical resistance changes, the change in the electrical resistance is determined by applying a constant sense current from the Al terminal film 48 to the voltage value. By detecting as a change in
This is to acquire the status of the external magnetic field, that is, the signal magnetic field from the magnetic recording medium. The magnetoresistance change rate of this spin valve magnetoresistance sensor is about 5%.

In such a magnetoresistive element, in order to read a signal from a track written on a magnetic recording medium with a fine width without being affected by an adjacent track, the read width of a read head, ie, the read width of a read head, , The core width 49 must be smaller than the track width recorded on the magnetic recording medium.

However, the CoC at both ends of the spin valve film is used.
In the portion in contact with the rPt hard bias film 47,
Since a huge magnetic field is applied from the CoCrPt hard bias film 47, the movement of the NiFe free layer 42 and the CoFe free layer 43 becomes slow in the region of about 0.1 to 0.2 μm at both ends, and a dead portion 50 is generated. I do.

Due to the generation of the dead portion 50, it is necessary to form the substantial core width 0.2 to 0.4 μm wider than the apparent core width, and to read a 0.3 μm track. A core width of about 0.8 μm is required. However, the change in magnetoresistance in the insensitive portion 50 is small, and the electrical resistance of the spin valve film is much larger than that of the Al terminal film 48. Therefore, when the actual core width is formed larger than the required core width. Results in significantly lowering the output of the magnetoresistive element.

Therefore, in order to solve such a problem,
Since research on an overlaid type magnetoresistive element is currently being conducted, this overlaid type magnetoresistive element will be described with reference to FIG. FIG. 6 (b) is a schematic cross-sectional view of a conventional overlay type magnetoresistive element. The basic configuration is exactly the same as that of the lead of FIG. 6 (a). The magnetoresistive effect element adopts a structure in which the distance between the CoCrPt hard bias films 47 is wider than the distance between the pair of Al terminal films 51, that is, an overlaid structure. To make the dead part 5
Since 0 is away from the Al terminal film 51 for detecting the reproduction output, no current flows in the insensitive portion 50, so that the output can be efficiently taken out.

[0012]

However, actually, the PdPtMn antiferromagnetic layer 46 on the top of the spin valve film is actually used.
Has a higher electrical resistance than the other layers,
The current flowing from the scattered portion flows and a part of the current also flows to the insensitive portion 50, which causes a reduction in efficiency.

In addition, even in the portion which becomes the insensitive portion 50, although the magnetoresistive effect changes although it is small, it causes the core width 52 to be finely formed to be widened.

Accordingly, it is an object of the present invention to prevent the signal reading width from being increased due to the overlaid structure and to increase the current use efficiency.

[0015]

FIG. 1 is an explanatory view of the principle configuration of the present invention. Referring to FIG. 1, means for solving the problems in the present invention will be described. In addition, FIG.
It is a schematic sectional view of a magnetoresistive effect element, and numerals 1 and 3 in a figure are a substrate used as a lower read gap layer, for example, and an intermediate layer, respectively. See FIG. 1 (1) In the present invention, a magnetic domain control film 7 is provided at both ends of a magnetoresistive film 6, and a pair of magnetic field control films 7 is provided above the magnetoresistive film 6 and the magnetic domain control film 7. Terminal film 10
In the overlay type magnetoresistive element provided with
The thickness of a portion below the terminal portion of the antiferromagnetic layer 5 constituting the magnetoresistive film 6 is smaller than the thickness of the portion where the terminal film 10 is not formed.

As described above, the thickness of the lower portion of the terminal portion of the antiferromagnetic layer 5 constituting the magnetoresistive effect film 6 is the portion where the terminal film 10 is not formed, that is, the thickness of the thick portion 8. By reducing the electric resistance by making the thickness smaller than the thickness, the dispersion of the current can be reduced, and the increase in the core width can be suppressed.

Further, by forming the thin portion 9 in this manner, the fixed layer 4 below the thin portion 9 is substantially equal to the magnetic layer whose magnetization is not fixed by the magnetic field from the magnetic recording medium, ie, the free layer 2. Since the same movement is started, the magnetoresistive effect hardly appears in this portion, and it is possible to prevent the core width from expanding.

(2) The present invention relates to a magnetoresistive film 6
In the overlaid type magnetoresistive element, a magnetic domain control film 7 is provided at both ends of the magnetoresistive effect film, and a pair of terminal films 10 for supplying a current to the magnetoresistive effect film 6 are provided above the magnetic domain control film 7. The thickness of a part of the antiferromagnetic layer 5 constituting the magnetoresistive film 6 immediately below the end of the terminal film 10 is:
It is characterized in that it is thinner than the portion where the terminal film 10 is not formed.

As described above, a portion of the antiferromagnetic layer 5 immediately below the end of the terminal film 10 may be a thin portion 9, and the pinning force on the fixed layer 4 is increased by the thick antiferromagnetic layer 5 remaining at both ends. Does not deteriorate.

(3) The present invention relates to a magnetoresistive film 6
In the overlaid type magnetoresistive element, a magnetic domain control film 7 is provided at both ends of the magnetoresistive effect film, and a pair of terminal films 10 for supplying a current to the magnetoresistive effect film 6 are provided above the magnetic domain control film 7. A feature of the present invention is that a portion of the antiferromagnetic layer 5 constituting the magnetoresistive film 6 which is under the terminal portion is removed.

As described above, by removing the portion below the terminal portion of the antiferromagnetic layer 5, it can be expected to suppress the current dispersion due to the connection resistance between the terminal film 10 and the magnetoresistive film 6. Further, since no change in magnetoresistance occurs except at the core width, the efficiency is further improved, and the core width can be reduced to only the width of the remaining antiferromagnetic layer 5, that is, the thickness of the thick portion 8.

(4) The present invention relates to the magnetoresistive film 6
In the overlaid type magnetoresistive element, a magnetic domain control film 7 is provided at both ends of the magnetoresistive effect film, and a pair of terminal films 10 for supplying a current to the magnetoresistive effect film 6 are provided above the magnetic domain control film 7. In addition, a part of the antiferromagnetic layer 5 constituting the magnetoresistive effect film 6 immediately below the end of the terminal film 10 is removed.

As described above, when the antiferromagnetic layer 5 is removed,
A part of the antiferromagnetic layer 5 immediately below the end of the terminal film 10 may be removed, and the pinning force on the fixed layer 4, that is, the pinned layer does not deteriorate due to the antiferromagnetic layers 5 remaining on both ends. .

(5) The present invention relates to a magnetoresistive film 6
In the overlaid type magnetoresistive element, a magnetic domain control film 7 is provided at both ends of the magnetoresistive effect film, and a pair of terminal films 10 for supplying a current to the magnetoresistive effect film 6 are provided above the magnetic domain control film 7. In addition, a portion of the antiferromagnetic layer 5 and the fixed layer 4 that constitute the magnetoresistive film 6 and a lower portion of the terminal portion is removed.

As described above, when the antiferromagnetic layer 5 is removed,
It is also preferable to remove the portion of the fixed layer 4 below the terminal film 10, and it is expected that the electric resistance is further reduced and the distribution of current can be reduced.

(6) The present invention relates to a magnetoresistive film 6
In the overlaid type magnetoresistive element, a magnetic domain control film 7 is provided at both ends of the magnetoresistive effect film, and a pair of terminal films 10 for supplying a current to the magnetoresistive effect film 6 are provided above the magnetic domain control film 7. A part of the antiferromagnetic layer 5 and the fixed layer 4 that constitute the magnetoresistive film 6 and a portion immediately below the end of the terminal film 10 is removed.

As described above, when the fixed layer 4 is removed, a portion immediately below the end of the terminal film 10 may be removed, and the pinning force on the fixed layer 4 is degraded by the antiferromagnetic layers 5 remaining on both ends. I will not let you.

(7) According to the present invention, in any one of the above (1) to (6), the magnetoresistive effect film 6 shares a single spin valve film or a magnetic layer whose magnetization is not fixed. It is one of the dual spin valve films.

As described above, the magnetoresistive film 6 used for the overlay type magnetoresistive element may be either a single spin valve film or a dual spin valve film sharing a magnetic layer whose magnetization is not fixed. When the dual spin valve film is used, the sensitivity is improved but the structure is complicated.

[0030]

Referring to FIGS. 2 and 3, a description will be given of a process of manufacturing an overlay type magnetoresistive element used in a read head according to a first embodiment of the present invention. Referring to FIG. 2A, first, a ₂ μm thick Al ₂ O ₃ film (not shown) is deposited on an Al ₂ O ₃ —TiC substrate (not shown) by a sputtering method, and then selective electrolytic plating is performed. Using the method, 100
While applying a magnetic field of [Oe], the thickness is 1 to 3 μm,
For example, a 3 μm NiFe film is formed to form a lower magnetic shield layer (not shown), and then a sputtering method is used.
Al ₂ O ₃ having a thickness of, for example, 500 ° (= 50 nm)
After depositing the film 11, a lower read gap layer is formed by patterning into a predetermined shape by an ion milling method, and then a spin valve film is deposited.

The spin valve film is used as a base layer by sputtering while applying a magnetic field of 80 [Oe] to the NiFe free layer 12 serving as a free layer. After forming a Ta film (not shown) with a thickness of, for example, 50 °, the thickness is, for example,
40 ° NiFe free layer 12, having a thickness of, for example, 25
{CoFe free layer 13, thickness of, for example, 25} C
u intermediate layer 14, a CoFe pinned layer 15 having a thickness of, for example, 25 °, a PdPtMn film antiferromagnetic layer 16 having a thickness of 20 to 300 °, for example, 250 °, and a Ta protective film having a thickness of 60 ° (shown in FIG. Are sequentially laminated. The composition of NiFe in this case is, for example, Ni ₈₁ Fe
₁₉ , the composition of CoFe is, for example, Co ₉₀ Fe ₁₀ , and the composition of PdPtMn is, for example, Pd ₃₁ P
a t ₁₇ Mn _52, when the applied magnetic field is too large, it is considered that adversely affect the film thickness distribution and the like by a sputtering method.

Next, in order to fix the magnetization direction of the CoFe pinned layer 15, while applying a DC magnetic field of 200 kA / m in a direction perpendicular to the magnetic field applied at the time of film formation, at 230 ° C. for 1 to 3 hours in a vacuum. The heat treatment of P
The magnetization direction of the dPtMn antiferromagnetic layer 16 is the direction of the applied DC magnetic field. In this case, in the heat treatment step at 230 ° C., Cu and NiFe
In order to prevent mutual diffusion with the free layer 12, a CoFe free layer 13 serving as a barrier layer is provided between the two to form a two-layer free layer.

Next, as shown in FIG. 2B, the exposed portion of the spin valve film is removed by performing ion milling using Ar ions using the resist pattern 17 having a width obtained by adding the dead portion on both sides of the element to the core width as a mask. I do. For reading a magnetic recording medium signal having a recording density of 40 Gbit / inch ² , the core width is 0.25 μm and the width of the dead portion is 0.15 μm.
m, the width of the resist pattern 17 is 0.5
It is necessary to be about 5 μm.

Next, as shown in FIG. 2C, a high coercive force film C serving as a magnetic domain control film is formed on the entire surface.
The oCrPt hard bias film 18 is deposited by sputtering so as to be slightly thinner than the spin valve film, for example, to have a thickness of about 200 °. The composition of CoCrPt in this case is, for example, Co ₇₈ Cr ₁₀ Pt ₁₂
It is.

Next, as shown in FIG. 3D, the CoCrP deposited on the resist
After the hard bias film 18 is removed together with the resist pattern 17, ion milling is performed using the new resist pattern 19 as a mask to obtain PdPtMn.
The exposed portion of the antiferromagnetic layer 16 is removed by about 170 ° to form a thin portion 20 having a thickness of, for example, about 80 °.

Next, after removing the resist pattern 19, an Al film is deposited on the entire surface to a thickness of, for example, about 1000 ° by sputtering, and an opening corresponding to the core width is formed. The exposed Al film is removed by ion milling using the resist pattern 21 as a mask to form a pair of Al terminal films 22.

Next, by removing the resist pattern 21, an overlay type magnetoresistance using a single spin-valve film whose core width 23 corresponds to the width of the projection of the PdPtMn antiferromagnetic layer 16 is obtained. The basic structure of the effect element is completed.

In this case, the PdP contacting the Al terminal film 22
Since the thin portion 20 of the tMn antiferromagnetic layer 16 is thin,
In the drawing, the dispersion of the current indicated by the arrow is reduced, and the current efficiently flows in the core width 23, that is, the area corresponding to the read width, so that a high output is obtained.

The dead portion 2 directly below the thin portion 20
In the CoFe pinned layer 15 adjacent to No. 4, the pinning force from the thin portion 20 is weakened, so that the magnetic field from the magnetic recording medium starts to move almost the same as the NiFe free layer 12. The small change portion 25 does not appear, thereby suppressing the effective core width from expanding.

Next, with reference to FIGS. 4 and 5, the overlay type magnetoresistive element according to the second to fifth embodiments of the present invention will be briefly described. In the embodiment, the basic manufacturing steps are exactly the same as those in the first embodiment, and the description of the same parts will be omitted. First, referring to FIG.
An embodiment will be described.

FIG. 4A is a schematic sectional view of an overlay type magnetoresistive element according to a second embodiment of the present invention. The difference is that the exposed portion of the PdPtMn antiferromagnetic layer 16 is completely removed in the step of FIG.

In the second embodiment, since the Al terminal film 22 and the CoFe pinned layer 15 are in direct electrical contact with each other, the distribution of the current indicated by the arrow in the figure becomes smaller, and the core width 23, ie, the core width 23, is reduced. Since the current flows more efficiently in the area corresponding to the reading width, a high output can be obtained.

Further, the pinning force from the PdPtMn antiferromagnetic layer 16 does not act on the CoFe pinned layer 15 in the region from which the PdPtMn antiferromagnetic layer 16 has been removed and is adjacent to the insensitive portion 24. No change occurs in the non-change portion 26, whereby the effective core width can be suppressed from being increased.

Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 4B is a schematic cross-sectional view of the overlay type magnetoresistive element according to the third embodiment of the present invention. The difference from the above-described first embodiment is as follows. 3D, the thin portion 20 near the core width 23 is selectively removed after the step of FIG. 3D. For example, the resist pattern 19 is left after the step of FIG. A new resist is applied in this state, exposed and developed so that only the vicinity of both sides of the resist pattern 19 is removed, and ion milling is performed using the new resist pattern as a mask to remove the exposed portion of the thin portion 20. You only have to remove it.

In the third embodiment, the Al terminal film 22 and the CoFe pinned layer
5 makes direct electrical contact, the variance of the current indicated by the arrow in the figure becomes smaller, and the current flows more efficiently in the area corresponding to the read width, so that a high output is obtained.

The CoFe pinned layer 15 is also pinned by the remaining portion of the thin portion 20, that is, the pinning force from the antiferromagnetic layer 27, so that the PdPtMn antiferromagnetic layer 1
The CoFe pinned layer 15 immediately below 6 is surely pinned. Although the pinning force from the thin portion 20 acts on the CoFe pinned layer 15 at the portion where the thin portion 20 is removed, the force is not so strong. When the movement starts, this portion becomes a small change portion 25 where the magnetoresistance effect hardly appears, thereby suppressing the effective core width from expanding.

Next, a fourth embodiment of the present invention will be described with reference to FIG. FIG. 4C is a schematic cross-sectional view of an overlay type magnetoresistive element according to a fourth embodiment of the present invention. The difference from the first embodiment described above is as follows. 3D, the exposed portion of the PdPtMn antiferromagnetic layer 16 is completely removed, and the CoFe pinned layer 15 thereunder is also removed.

In the fourth embodiment, since the Al terminal film 22 and the Cu intermediate layer 14 are in direct electrical contact, the variance of the current indicated by the arrow in the figure becomes smaller, which corresponds to the reading width. Since the current flows more efficiently in the region, a high output is obtained.

In the region where the CoFe pinned layer 15 has been removed, the pinned layer does not exist, so that there is no change in the portion 26 where no magnetoresistance effect occurs, thereby suppressing the effective core width from expanding. Can be.

Next, a fifth embodiment of the present invention will be described with reference to FIG. FIG. 5 is a schematic sectional view of an overlay type magnetoresistive element according to a fifth embodiment of the present invention. The difference from the first embodiment is that a so-called spin valve film is used. While using a dual spin valve film, FIG.
In the step (d), the exposed portion of the PdPtMn antiferromagnetic layer 16 is completely removed.

That is, a so-called dual spin-valve film is used as the spin-valve film in the above-described second embodiment.
The Fe-free layer 14 may be formed symmetrically up and down in a shared manner. For example, after forming a Ta film (not shown) having a thickness of 50 ° as an underlayer, the thickness may be 20 to 30 μm.
0 °, for example, 250 ° PdPtMn film antiferromagnetic layer 3
1, a CoFe pinned layer 30 having a thickness of, for example, 25 °,
The Cu intermediate layer 29 having a thickness of, for example, 25 °, the CoFe free layer 28 having a thickness of, for example, 25 °, the NiFe free layer 12 having a thickness of, for example, 40 °, and the thickness being, for example,
25 ° CoFe free layer 13 having a thickness of, for example, 25
ＣｕCu intermediate layer 14 and a thickness of, for example, 25ÅCoF
e-pinned layer 15 having a thickness of 20 to 300 °, for example, 25
0 ° PdPtMn film antiferromagnetic layer 16 and thickness 6
A 0 ° Ta protection film (not shown) may be sequentially laminated.

The basic operation and effect of the fifth embodiment are similar to those of the second embodiment.
Since the Al terminal film 22 and the CoFe pinned layer 15 are in direct electrical contact with each other, current dispersion is reduced, and current flows more efficiently in a region corresponding to the read width.
High output is obtained.

The embodiments of the present invention have been described above. However, the present invention is not limited to the configuration described in each embodiment, and various modifications are possible. For example, only one example shown in FIG. 5 is shown for a magnetoresistive effect element using a dual spin valve film, but the PdPtMn antiferromagnetic layer 1 corresponds to the above-described first embodiment.
6 may be left as a thin portion, or a portion of the thin portion may be selectively removed to correspond to the third embodiment. The peripheral portion of the CoFe pinned layer 15 may be removed to correspond to the fourth embodiment.

In the third embodiment, only the thin portion is selectively removed. However, the CoFe pinned layer 15 below the removed portion may be removed.
Further, when removing portions are formed on both sides of the core width in this manner, the PdPtMn antiferromagnetic layers 16 on both sides of the core width are formed without forming thin portions in the PdPtMn antiferromagnetic layer 16.
May be removed, and the underlying CoFe pinned layer 15 may be removed.

In the first embodiment described above, the entire peripheral portion of the PdPtMn antiferromagnetic layer 16 is made the thin portion 20, but only the portions on both sides of the core width may be made thin. In addition, even when the spin valve film is a dual spin valve film, the thin portions may be formed only in the vicinity of both sides of the core width.

In the description of the first to fourth embodiments of the present invention, NiFe /
Although a single spin valve film made of CoFe / Cu / CoFe / PdPtMn is used, it is not limited to such a single spin valve film.
A single spin valve film having another laminated structure such as Fe / Cu / NiFe / FeMn may be used.

In the description of each of the above embodiments, CoCrPt of a high coercive force film is used as the magnetic domain control film. However, the present invention is not limited to CoCrPt.
Other high coercivity films such as oPt and CoCr may be used,
Further, an antiferromagnetic film such as PdPtMn may be used.

In each of the above embodiments, N
iFe, CoFe, PdPtMn, and CoCrPt
Ni ₈₁ Fe ₁₉ , Co ₉₀ Fe ₁₀ , Pd ₃₁ P
Although t ₁₇ Mn ₅₂ and Co ₇₈ Cr ₁₀ Pt ₁₂ are used, the composition ratio is not limited to such a composition ratio. If the composition ratio is appropriately selected according to the required magnetic characteristics and processing characteristics, etc. Good thing.

In the above description of each embodiment of the present invention, the Al terminal film 22 is used as the lead electrode. However, the present invention is not limited to such an Al film.
A film may be used, or a single W film or Ta film may be used. Further, for example, a 10 nm Ta film, a 10 nm TiW film, and an 80 nm Ta film are sequentially deposited. By doing so, a multilayer film structure may be obtained.

In the above description of each embodiment of the present invention, ion milling is also used in the patterning step of the Al terminal film 22, but RIE (reactive ion etching) is used instead of ion milling. It is a good thing.

In the above description of each embodiment of the present invention, since a read head used for an HDD is premised, an Al ₂ O ₃ —TiC substrate is used as a substrate. When formed as an effect element, a substrate such as a Si substrate or a glass substrate having a SiO ₂ film formed on the surface may be used.

In the description of each embodiment of the present invention, a single read head has been described. However, the present invention is not limited to such a single read head, but is an inductive type. The present invention is also applied to a composite type thin film magnetic head laminated with a thin film magnetic head.

[0063]

According to the present invention, the thickness of the antiferromagnetic layer other than the original read area of the magnetoresistive element constituting the read head is reduced, or at least the antiferromagnetic layers on both sides of the read area are reduced. The removal allows the current distribution to be controlled, thereby minimizing the current detection in the overlap portion, which is a problem in the overlay structure. A core width and a good sensitivity that can be obtained can be obtained, which greatly contributes to the spread of high-density HDD devices.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a basic configuration of the present invention.

FIG. 2 is an explanatory diagram of a manufacturing process partway through the first embodiment of the present invention.

FIG. 3 is an explanatory view of a manufacturing process of the first embodiment of the present invention after FIG. 2;

FIG. 4 is a cross-sectional view of a magnetoresistive element according to second to fourth embodiments of the present invention.

FIG. 5 is a sectional view of a magnetoresistive element according to a fifth embodiment of the present invention.

FIG. 6 is a schematic sectional view of a conventional magnetoresistance effect element.

[Explanation of symbols]

1 substrate 2 free layer 3 intermediate layer 4 fixed layer 5 antiferromagnetic layer 6 magnetoresistive film 7 domain control film 8 thick portion 9 thin portions 10 terminal film 11 Al ₂ O ₃ film 12 NiFe free layer 13 CoFe free layer 14 Cu intermediate layer 15 CoFe pinned layer 16 PdPtMn antiferromagnetic layer 17 resist pattern 18 CoCrPt hard bias film 19 resist pattern 20 thin part 21 resist pattern 22 Al terminal film 23 core width 24 dead part 25 slight change part 26 no change part 27 anti Ferromagnetic layer 28 CoFe free layer 29 Cu intermediate layer 30 CoFe pinned layer 31 PdPtMn antiferromagnetic layer 41 Al ₂ O ₃ film 42 NiFe free layer 43 CoFe free layer 44 Cu intermediate layer 45 CoFe pinned layer 46 PdPtMn antiferromagnetic layer 47 CoCrPt hard via Film 48 Al terminal film 49 core width 50 dead part 51 Al terminal film 52 core width

Claims (7)

[Claims] An overlay type wherein a magnetic domain control film is provided at both ends of a magnetoresistive film, and a pair of terminal films for supplying a current to the magnetoresistive film are provided above the magnetoresistive film and the magnetic domain control film. In the magnetoresistive element, a thickness of a portion of the antiferromagnetic layer constituting the magnetoresistive effect film which is below the terminal portion is smaller than a thickness of a portion where the terminal film is not formed. Overlay type magnetoresistive element. 2. An overlaid type in which a magnetic domain control film is provided at both ends of a magnetoresistive film, and a pair of terminal films for supplying a current to the magnetoresistive film are provided above the magnetoresistive film and the magnetic domain control film. In the magnetoresistive element, the thickness of a portion of the antiferromagnetic layer that forms the magnetoresistive effect film immediately below an end of the terminal film is smaller than the thickness of a portion where the terminal film is not formed. Characteristic overlay type magnetoresistive element. 3. An overlay type wherein a magnetic domain control film is provided at both ends of the magnetoresistive film, and a pair of terminal films for supplying a current to the magnetoresistive film are provided above the magnetoresistive film and the magnetic domain control film. An overlay type magnetoresistive element, wherein a portion of the antiferromagnetic layer constituting the magnetoresistive film, which is below the terminal portion, is removed. 4. An overlay type in which a magnetic domain control film is provided at both ends of a magnetoresistive effect film, and a pair of terminal films for supplying current to the magnetoresistive effect film are provided above the magnetoresistive effect film and the magnetic domain control film. An overlaid type magnetoresistive element, wherein a part of an antiferromagnetic layer constituting the magnetoresistive film, which is immediately below an end of the terminal film, is removed. 5. An overlay type in which a magnetic domain control film is provided at both ends of a magnetoresistive effect film, and a pair of terminal films for supplying a current to the magnetoresistive effect film are provided above the magnetoresistive effect film and the magnetic domain control film. An overlay type magnetoresistive element, wherein a portion of the antiferromagnetic layer and the fixed layer constituting the magnetoresistive film, which is below the terminal portion, is removed. 6. An overlay type in which a magnetic domain control film is provided at both ends of a magnetoresistive film, and a pair of terminal films for supplying a current to the magnetoresistive film are provided above the magnetoresistive film and the magnetic domain control film. An overlaid type magnetoresistive element, wherein a part of the antiferromagnetic layer and the fixed layer constituting the magnetoresistive film, which are directly below an end of the terminal film, are removed. 7. The method according to claim 1, wherein the magnetoresistive effect film is one of a single spin valve film and a dual spin valve film sharing a magnetic layer whose magnetization is not fixed. The overlay type magnetoresistive element according to any one of the preceding claims.