JP2000216455A - Magnetic resistnce effect element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic resistance effect element where an upper gap layer can be formed by reducing the current loss of sense current to a hard bias layer, preferentially making sense current flow to a sense area occupied in the center part of a multilayer film, improving reproduced output and securing appropriate insulating property. SOLUTION: An intermediate layer 21 formed of an insulating material or a high resistance material having a resistance value higher than that of an electrode layer 18 is arranged between a hard bias layer 17 and the electrode layer 18. The electrode layer 18 is formed by extending it onto a multilayer film 16. Thus, sense current to the hard bias layer 17 can be suppressed and sense current can directly be made to flow from the electrode layer 18 to the multilayer film 16. Thus, reproduction sensitivity can be improved and reproduced output can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to, for example, an electric resistance based on the relationship between the magnetization direction of a pinned magnetic layer (pinned magnetic layer) and the magnetization direction of a free magnetic layer affected by an external magnetic field. More particularly, the present invention relates to a magnetoresistive element capable of suppressing a shunt of a sense current to a hard bias layer and allowing a sense current to flow directly from an electrode layer to a multilayer film.

[0002]

2. Description of the Related Art FIG. 12 is a sectional view of a conventional structure of a magnetoresistive element as viewed from the ABS. The magnetoresistance effect element shown in FIG. 12 is a GMR utilizing the giant magnetoresistance effect.
(Giant magnetoresistive) A device called a spin-valve thin film device, which is a type of device, and detects a recording magnetic field from a recording medium such as a hard disk.

This spin-valve type thin film element comprises an underlayer 6, an antiferromagnetic layer 1, a pinned magnetic layer (pinned magnetic layer) 2, a nonmagnetic conductive layer 3, a free magnetic layer (Free) 4,
And a protective film 7, a pair of hard bias layers 5 and 5 formed on both sides of the multilayer film 9, and a pair of electrode layers formed on the hard bias layers 5 and 5. 8 and 8. The underlayer 6 and the protective layer 7 are formed of a Ta (tantalum) film or the like. The track width Tw is determined by the width of the upper surface of the multilayer film 9.
(Also referred to as the optical track width O-Tw).

The antiferromagnetic layer 1 has an Fe-Mn (iron-manganese) alloy film or a Ni-Mn (nickel-manganese) alloy film, and the fixed magnetic layer 2 and the free magnetic layer 4 have Ni-Fe.
(Nickel-iron) alloy film, nonmagnetic conductive layer 3 has Cu
A (copper) film, a Co-Pt (cobalt-platinum) alloy film for the hard bias layers 5 and 5, and a Ta or Cr film for the electrode layers 8 and 8 are generally used.

As shown in FIG. 12, the magnetization of the pinned magnetic layer 2 is converted into a single magnetic domain in the Y direction (the direction of the leakage magnetic field from the recording medium; the height direction) by the exchange anisotropic magnetic field with the antiferromagnetic layer 1. The magnetization of the free magnetic layer 4 is aligned in the X direction under the influence of the bias magnetic field from the hard bias layers 5 and 5. That is, the magnetization of the fixed magnetic layer 2 and the magnetization of the free magnetic layer 4 are set to be orthogonal.

In this spin-valve thin film element, a detection current (sense current) is applied to the multilayer film 9 from the electrode layers 8 formed on the hard bias layers 5. The running direction of a recording medium such as a hard disk is the Z direction,
When a leakage magnetic field from the recording medium is applied in the Y direction, the magnetization of the free magnetic layer 4 changes from X to Y. The electrical resistance changes due to the relationship between the change in the direction of magnetization in the free magnetic layer 4 and the fixed magnetization direction of the fixed magnetic layer 2 (this is referred to as a magnetoresistance effect). Due to the change, a leakage magnetic field from the recording medium is detected.

[0007]

However, FIG.
The following problems occur in the structure of the conventional magnetoresistive element shown in FIG. In the magnetoresistive element shown in FIG. 12, since the electrode layers 8 and 8 are not directly in a state of current conduction to the multilayer film 9, the sense current from the electrode layers 8 and 8 flows to the hard bias layers 5 and 5 once. , The hard bias layer 5,
5 makes it easier for the sense current to flow through the multilayer film 9.

That is, the sense current from the electrode layers 8, 8 flows to the multilayer film 9 via the hard bias layers 5, 5, so that the ratio of the sense current flowing to the multilayer film 9 is reduced, and the read sensitivity is reduced. However, there is a problem that the reproduction output is reduced.

Further, as described above, the magnetization of the fixed magnetic layer 2 forming the multilayer film 9 is fixed as a single magnetic domain in the Y direction in the drawing. Hard bias layers 5 and 5 are provided. Therefore, particularly, the magnetization at both ends of the fixed magnetic layer 2 is
Under the influence of the bias magnetic field from the hard bias layers 5 and 5, the semiconductor laser is not fixed in the Y direction in the drawing.

In other words, the magnetization of the free magnetic layer 4 and the magnetization of the fixed magnetic layer 2 which are magnetized in the X direction by receiving the magnetizations of the hard bias layers 5 and 5 in the X direction are, In the vicinity of the side end of No. 9, there is no orthogonal relationship. The reason that the magnetization of the free magnetic layer 4 and the magnetization of the fixed magnetic layer 2 are set to be orthogonal to each other is that the magnetization of the free magnetic layer 4 can be easily marked even with a small external magnetic field, and the electrical resistance changes greatly. This is because the reproduction sensitivity can be improved. Further, the orthogonal relationship makes it possible to obtain an output waveform having good symmetry.

In addition, the magnetization of the free magnetic layer 4 near its side edge is affected by the strong magnetization from the hard bias layers 5 and 5 and is therefore easily fixed, so that the magnetization is hardly fluctuated by an external magnetic field. Thus, as shown in FIG. 12, a dead area D having poor reproduction sensitivity is formed near the side end of the multilayer film 9.

The central region of the multilayer film 9 excluding the insensitive region D is a sensitive region E which substantially contributes to the reproduction of the recording magnetic field and exerts the magnetoresistance effect.
Is the track width Tw set when the multilayer film 9 is formed.
It is shorter by the width dimension of the insensitive region D than in the above case.

As described above, in the multilayer film 9 of the magnetoresistive element, a dead region D which hardly contributes to the reproduction output is formed near both sides thereof, and this dead region D simply increases the DC resistance (DCR). It was only an area.

In the structure of the conventional magnetoresistance effect element shown in FIG. 12, the presence of the insensitive region D results in a drastic decrease in the amount of sense current flowing to the sensitivity region E where the magnetoresistance effect can be substantially exerted. Therefore, an effective amount of the sense current cannot be passed through the sensitivity region E, so that the output is more likely to decrease as the DC resistance increases. It is considered that the problem of the decrease in the reproduction output due to the presence of the dead area D becomes more prominent as the track becomes narrower in the future.

Therefore, if the electrode layers 10 and 10 are overlapped on the multilayer film 9 as in the magnetoresistive element shown in FIG. 13, the electrode layer 10 and the multilayer film 9 can be in a conducting state. It is considered that a sense current can effectively flow from the electrode layer 10 to the multilayer film 9.

In this case, in order to allow a sense current to flow effectively from the electrode layer 10 to the multilayer film 9, the thickness of the electrode layer 10 is made larger than before, especially on the multilayer film 9 in contact with the multilayer film 9. The thickness h1 of the electrode layer 10 must be increased to reduce the DC resistance of the electrode layer 10.

If the contact thickness h1 of the electrode layer 10 with the multilayer film 9 is small, the sense current from the electrode layer 10 is distributed to the hard bias layer 5 because the DC resistance of the electrode layer 10 increases. It becomes easier to wash, and eventually, as before,
This is because a decrease in reproduction output becomes a problem.

As described above, the electrode layer 10 is overlapped on the multilayer film 9 and the multilayer film 9 of the electrode layer 10 is formed.
It is thought that if the contact thickness h1 with respect to is increased, the shunt of the sense current to the hard bias layer 5 can be suppressed, and the sense current can effectively flow from the electrode layer 10 to the multilayer film 9.

However, as shown in FIG.
0 protrudes from the upper surface of the multilayer film 9 with a thickness h1.
Since a large step is formed between the upper surface of the electrode layer 10 and the upper surface of the multilayer film 9, when forming the upper gap layer 11 made of an insulating material on the multilayer film 9 from above the electrode layer 10, The gap layer 11 has poor step coverage, and a film break occurs at the step. Therefore, there arises a problem that the insulating properties of the upper gap layer 11 cannot be sufficiently secured.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems. In particular, the present invention makes it possible to reduce the current loss of a sense current to a hard bias layer, and to provide a sensitivity region where a sense current occupies a central portion of a multilayer film. It is an object of the present invention to provide a magnetoresistive effect element capable of improving the reproduction output by allowing the flow to flow preferentially, and capable of forming an upper gap layer while securing appropriate insulation properties.

[0021]

According to the present invention, an antiferromagnetic layer is formed in contact with the antiferromagnetic layer, and the magnetization direction is fixed by an exchange anisotropic magnetic field with the antiferromagnetic layer. A multilayer film having a magnetic layer and a free magnetic layer formed on the fixed magnetic layer via a non-magnetic conductive layer; and a magnetic layer formed on both sides of the multilayer film, the magnetization direction of the free magnetic layer being set to the fixed magnetic layer. A pair of bias layers aligned in a direction crossing the magnetization direction of the magnetic layer, and a pair of conductive layers formed on the bias layer. Is provided with an intermediate layer formed of a high-resistance material having a higher resistance than the electrode layer and / or an insulating material, and the electrode layer is formed to extend over the multilayer film. Is characterized by .

In the present invention, the multilayer film is laminated from the bottom in the order of an antiferromagnetic layer, a pinned magnetic layer, a nonmagnetic conductive layer and a free magnetic layer, and the antiferromagnetic layer is formed thereon. Preferably, a pair of bias layers, an intermediate layer, and an electrode layer are laminated via a metal film on the antiferromagnetic layers on both sides of the respective layers.

The present invention also provides a free magnetic layer, a nonmagnetic conductive layer formed above and below the free magnetic layer, and formed on one nonmagnetic conductive layer and below the other nonmagnetic conductive layer, A multilayer film having a fixed magnetic layer in which the magnetization direction is fixed, and an antiferromagnetic layer formed on one fixed magnetic layer and under the other fixed magnetic layer; and formed on both sides of the multilayer film. A pair of bias layers for aligning the magnetization direction of the free magnetic layer in a direction crossing the magnetization direction of the fixed magnetic layer;
In a magnetoresistive element including a pair of conductive layers formed on the bias layer, a high-resistance material having a higher resistance than the electrode layer is provided between the hard bias layer and the electrode layer; And / or an intermediate layer made of an insulating material is provided, and the electrode layer is formed to extend over the multilayer film.

The antiferromagnetic layer is preferably formed of a PtMn alloy, or X-Mn (where X is one or more of Pd, Ir, Rh, and Ru). ) Alloy and Pt-Mn-X '(where X' is one or more elements of Pd, Ir, Rh, Ru, Au and Ag).

Further, the present invention provides a multilayer film having a magneto-resistance effect layer and a soft magnetic layer stacked with a non-magnetic layer interposed therebetween, a pair of bias layers formed on both sides of the multilayer film, A magnetoresistive element having a pair of electrode layers formed thereon, between the hard bias layer and the electrode layer, a high-resistance material having a higher resistance than the electrode layer and / or An intermediate layer made of an insulating material is provided, and the electrode layer is formed to extend over the multilayer film.

In the present invention, the high resistance material constituting the intermediate layer formed between the hard bias layer and the electrode layer includes TaSiO ₂ , TaSi, CrSiO ₂ , CrSi,
Any one of WSi, WSiO ₂ , TiN, TaN
Preferably, one or more species are selected.

In the present invention, the insulating material constituting the intermediate layer formed between the hard bias layer and the electrode layer includes Al ₂ O ₃ , SiO ₂ , Ti ₂ O ₃ , TiO, WO, A
It is preferable to select one or more of 1N, Si ₃ N ₄ , B ₄ C, SiC, and SiAlON.

Further, according to the present invention, the multilayer film is formed on both sides of the central region, which is excellent in reproducing sensitivity and can substantially exhibit the magnetoresistance effect, and is formed on both sides of the sensitive region. It is preferable that the electrode layer is formed so as to extend over the dead area.

In the present invention, the sensitivity region of the multilayer film is obtained by scanning a magnetoresistive element having electrode layers formed only on both sides of the multilayer film in a track width direction on a minute track on which a certain signal is recorded. In this case, among the obtained reproduction outputs, the output is defined as an area where 50% or more of the maximum output is obtained, and the dead area of the multilayer film is on both sides of the sensitivity area, and the output is the maximum output. It is defined as an area that is 50% or less. For example, the optical track width dimension O-Tw
Are formed with the same width as the sensitivity region.

An object of the present invention is to form a top gap layer on a magnetoresistive element so as to secure sufficient insulation while suppressing the shunt of a sense current to a hard bias layer. Therefore, in the present invention, an insulating material or an intermediate layer of a high resistance material having a higher resistance than the electrode layer is formed between the hard bias layer and the electrode layer, and the electrode layer is overlaid on the multilayer film. I wrapped it.

By arranging an intermediate layer such as an insulating material between the hard bias layer and the electrode layer, it is possible to reduce the shunt (current loss) of the sense current to the hard bias layer, and furthermore, the electrode layer is Since the electrode layer and the multilayer film are overlapped on the multilayer film, the electrode layer and the multilayer film can be brought into a conductive state on the multilayer film, and a sense current from the electrode layer can flow directly to the multilayer film.

In the case of the magnetoresistive element shown in FIG. 13, the electrode layer 10 is overlapped on the multilayer film 9, but in the case of FIG. Since the intermediate layer is not formed as in the present invention, the contact thickness h1 of the electrode layer 10 with respect to the multilayer film 9 is required to effectively flow a sense current from the electrode layer 10 to the multilayer film 9. It is necessary to reduce the DC resistance of the electrode layer 10 to suppress the shunt of the sense current to the hard bias layer 5. In this case, an abrupt step is generated between the upper surface of the electrode layer 10 and the upper surface of the multilayer film 9, and the upper gap layer 11 formed on the multilayer film 9 from the electrode layer 10 is caused by this step. Poor coverage,
Film breakage occurs, making it extremely difficult to ensure sufficient insulation.

On the other hand, in the present invention, as described above, since the intermediate layer formed of an insulating material or the like is interposed between the hard bias layer and the electrode layer, the electrode is formed regardless of the thickness of the electrode layer. It is difficult for the sense current from the layer to shunt to the hard bias layer, and therefore, compared to the case shown in FIG.
Even if the contact thickness of the electrode layer with the multilayer film is reduced, a sense current can be effectively passed from the electrode layer to the multilayer film. Therefore, in the present invention, the contact height of the electrode layer with respect to the multilayer film can be reduced to reduce the height of the step formed between the upper surface of the electrode layer and the upper surface of the multilayer film. It is possible to improve the step coverage of the upper gap layer formed over the range, and to secure a sufficient insulating property.

Incidentally, the multilayer film constituting the GMR element or the AMR element does not exhibit the magnetoresistive effect as a whole, but only the central region thereof has excellent reproduction sensitivity. This is a region where the magnetoresistance effect can be exhibited. The region of the multilayer film having excellent reproduction sensitivity is referred to as a sensitivity region, and the regions on both sides of the sensitivity region and having low reproduction sensitivity are referred to as dead regions. It is measured by the profile method. Hereinafter, the microtrack profile method will be described with reference to FIG.

As shown in FIG. 11, a conventional magnetoresistive effect including a multilayer film exhibiting a magnetoresistive effect, hard bias layers formed on both sides thereof, and an electrode layer formed on the hard bias layer. An element (see FIG. 12) is formed on a substrate. The electrode layer has a structure formed only on both sides of the multilayer film.

Next, the width A of the upper surface of the multilayer film not covered by the electrode layer is measured by an optical microscope. The width dimension A is defined as a track width Tw measured by an optical method (hereinafter, referred to as an optical track width dimension O-Tw).

Then, a certain signal is recorded on the recording medium in a minute track, and the magnetoresistive element is scanned in the track width direction on the minute track to obtain the width A of the multilayer film, the reproduction output, and the like. Measure the relationship. Alternatively, the recording medium side on which the minute track is formed is scanned over the magnetoresistive element in the track width direction, and the width dimension A of the multilayer film is determined.
The relationship with the reproduction output may be measured. The measurement result is
This is shown at the bottom of FIG.

From this measurement result, it can be seen that the reproduction output increases near the center of the multilayer film and decreases near the side of the multilayer film. from this result,
In the vicinity of the center of the multilayer film, the magnetoresistive effect is satisfactorily exerted and plays a role in the reproduction function. .

In the present invention, a region formed by the width dimension B on the upper surface of the multilayer film in which a reproduction output of 50% or more with respect to the maximum reproduction output is defined as a sensitivity region.
A region formed with a width C on the upper surface of the multilayer film where only a reproduction output of 0% or less can be generated was defined as a dead region.

In consideration of the fact that the multilayer film is composed of the sensitive region and the insensitive region as described above, in the present invention, the sense current is preferentially given to the sensitive region capable of substantially exhibiting the magnetoresistance effect. One of the purposes is to shed. Therefore, in the present invention, the electrode layer overlapping the multilayer film is extended to the dead area.

If the electrode layer is formed to extend over the dead area, the sense current can be preferentially supplied to the sensitive area while avoiding the dead area, and the reproduction output can be further improved. However, the electrode layer must not be formed to extend over the sensitive region. This is because this leads to noise generation and a reduction in reproduction output, as described later.

[0042]

FIG. 1 is a sectional view of the structure of a magnetoresistive element according to a first embodiment of the present invention, as viewed from the ABS side. In FIG. 1, only the central portion of the element extending in the X direction is shown broken. This magnetoresistive element is called a spin-valve thin film element, and uses a giant magnetoresistive (GMR) utilizing a giant magnetoresistive effect.
It is a kind of element. The spin-valve type thin-film element is provided at the trailing end of a floating slider provided in a hard disk device, and detects a recording magnetic field of a hard disk or the like. The moving direction of the magnetic recording medium such as a hard disk is the Z direction, and the direction of the leakage magnetic field from the magnetic recording medium is the Y direction.

The bottom of FIG. 1 is formed of Ta.
Underlayer 19 formed of a nonmagnetic material such as (tantalum)
It is. An antiferromagnetic layer 20, a fixed magnetic layer 12, a nonmagnetic conductive layer 13, and a free magnetic layer 14
Are laminated. Then, a protective layer 15 such as Ta (tantalum) is formed on the free magnetic layer 14. Each layer from the underlayer 19 to the protective layer 15 forms a multilayer film 16. As shown in FIG. 1, the width of the upper surface of the multilayer film 16 is formed at T30.

The fixed magnetic layer 12 is formed in contact with the antiferromagnetic layer 20, and is annealed in a magnetic field to
An exchange anisotropic magnetic field is generated at the interface between the antiferromagnetic layer 20 and the pinned magnetic layer 12 by exchange coupling, and the pinned magnetic layer 12
Are fixed in the illustrated Y direction.

In the present invention, the antiferromagnetic layer 20 is made of Pt-
It is formed of a Mn (platinum-manganese) alloy film.
The Pt-Mn alloy film has better corrosion resistance, higher blocking temperature, and higher exchange anisotropy than Fe-Mn alloy film, Ni-Mn alloy film, etc. which have been conventionally used as an antiferromagnetic layer. It has excellent properties as an antiferromagnetic material such as a large magnetic field (Hex).

Further, instead of the Pt-Mn alloy, X-
Mn (where X is one or more of Pd, Ir, Rh, and Ru) or Pt-
Mn-X '(where X' is Pd, Ir, Rh, Ru,
Au, Ag, or one or more elements).

The fixed magnetic layer 12 and the free magnetic layer 1
4 is a Ni-Fe (nickel-iron) alloy, Co (cobalt), Fe-Co (iron-cobalt) alloy, Fe-Co-
The nonmagnetic conductive layer 13 is made of a Ni alloy or the like.
Is formed of a nonmagnetic conductive material having a low electric resistance such as Cu (copper).

As shown in FIG. 1, the hard bias layers 1 are provided on both sides of the multilayer film 16 from the underlayer 19 to the protective layer 15.
7 and 17 are formed, and the hard bias layer 1 is formed.
Reference numerals 7 and 17 are made of, for example, a Co-Pt (cobalt-platinum) alloy or a Co-Cr-Pt (cobalt-chromium-platinum) alloy.

The hard bias layers 17, 17 are shown in FIG.
The magnetization of the free magnetic layer 14 is aligned in the X direction in the figure by a bias magnetic field in the X direction from the hard bias layers 17, 17.

Further, on the hard bias layers 17, 17, a non-magnetic material layer 23 made of, for example, Ta is used to form a high-resistance material or an insulating material having a higher resistance than an electrode layer 18 described later. Or an intermediate layer 21 in which the high-resistance material and the insulating material are laminated. When an oxide or a Si compound is used for the intermediate layer 21, it is preferable that the nonmagnetic material layer 23 be interposed between the hard bias layer 17 and the electrode layer 18. This is because, without the nonmagnetic material layer 23, diffusion between the hard bias layer 17 formed of, for example, CoPt and the intermediate layer 21 formed using an oxide or a Si compound is likely to occur. However, when an N compound is used for the intermediate layer 21, the above-mentioned diffusion is unlikely to occur, and therefore, the nonmagnetic material layer 23 may not be interposed.

In the present invention, the high resistance material constituting the intermediate layer 21 includes TaSiO ₂ , TaSi, CrSiO ₂ ,
It is preferable to select any one of CrSi, WSi, WSiO ₂ , TiN, and TaN, or a mixed film or a laminated film of two or more.

In the present invention, the intermediate layer 21 is formed.
Al insulating material_TwoO_Three, SiO _Two, Ti_TwoO_Three, Ti
O, WO, AlN, Si_ThreeN_Four, B_FourC, SiC, SiA
Any one of a single-layer film or a mixture of two or more
It is preferable to select a composite film or a laminated film.

As shown in FIG. 1, an electrode layer 18 is formed on the intermediate layer 21 via nonmagnetic material layers 24 such as Ta, and the electrode layer 18 is formed on the multilayer film 16 in the present invention. It is formed to extend to. Also in this case, as described above, oxide or Si is used as the intermediate layer 21.
When a compound is used, the nonmagnetic material layer 24 is preferably used. When an N compound is used as the intermediate layer 21, the nonmagnetic material layer 24 may or may not be used.

In the present invention, since the electrode layer 18 is formed to extend over the multilayer film 16, the electrode layer 18 and the multilayer film 16 are electrically connected on the multilayer film 16. . The electrode layer 18 is formed of, for example, Ta (tantalum) or Cr (chromium).

As described above, in the present invention, the intermediate layer 21 made of a high-resistance material and / or an insulating material having a higher resistance than the electrode layer 18 is provided between the hard bias layer 17 and the electrode layer 18. Since it is formed, the sense current from the electrode layer 18 does not easily flow to the hard bias layer 17, and the shunt of the sense current to the hard bias layer 17 can be reduced.

In the present invention, since the electrode layer 18 is formed to extend on the multilayer film 16, the sense current from the electrode layer 18 is hard biased due to the presence of the intermediate layer 21. The multilayer film 1 without the layer 17
Since the current flows directly from the electrode layer 18 formed on and in the multilayer film 16 to the multilayer film 16, the reproduction sensitivity can be increased and the reproduction output can be improved as compared with the related art.

In order to improve the reproduction output, the sense current from the electrode layer 18 is mainly controlled by the non-magnetic conductive layer 13 of the multilayer film 16.
Is one of the causes.

The magnetoresistance effect is exhibited by the three layers of the fixed magnetic layer 12, the nonmagnetic conductive layer 13, and the free magnetic layer 14.
The magnetization of the fixed magnetic layer 12 is fixedly magnetized in the Y direction in the drawing, and the magnetization of the free magnetic layer 14 is aligned in the track width direction (X direction in the drawing), and can be freely changed with respect to an external magnetic field. The magnetization of the free magnetic layer 14 fluctuates with respect to an external magnetic field, and a sense current flows through the nonmagnetic conductive layer 13 to move from one of the free magnetic layer 14 and the fixed magnetic layer 12 to the other layer. Electrons are scattered at the interface between the nonmagnetic conductive layer 13 and the pinned magnetic layer 12 or at the interface between the nonmagnetic conductive layer 13 and the free magnetic layer 14, and the electrical resistance changes. A reproduction output can be obtained by the voltage change based on the voltage.

In the present invention, as shown in FIG.
The electrode layer 18 is formed so as to extend over the multilayer film 6, and a sense current flows directly from the electrode layer 18 on the multilayer film 16 to the multilayer film 16. Therefore, the sense current also flows to the free magnetic layer 12 which is the upper layer of the nonmagnetic conductive layer 13 in the multilayer film 16, but is particularly likely to flow mainly to the nonmagnetic conductive layer 13 having a particularly low resistance.

On the other hand, in the conventional magnetoresistive element shown in FIG. 12, for example, the sense current from the electrode layer 8 is applied to the side surface of the multilayer film 9 via the hard bias layer 5 (X in the drawing).
Direction) into the multilayer film 9.
With such a structure, the sense current shunts not only to the nonmagnetic conductive layer 3 but also to the antiferromagnetic layer 1, the pinned magnetic layer 2, and the free magnetic layer 4, and the substantially nonmagnetic conductive layer 3 As a result, the amount of the sense current flowing through is reduced.

Therefore, in the structure of the magnetoresistive effect element according to the present invention, a sense current can be passed through the nonmagnetic conductive layer 13 in particular, so that a large magnetoresistive effect can be exhibited, and the reproduction output can be improved. Leads to the improvement of

In the present invention, since the intermediate layer 21 is provided, the electrode layer 1 formed particularly in contact with the multilayer film 16 is formed.
8, the sense current from the electrode layer 18 is not easily diverted to the hard bias layer 17 even if the contact thickness h2 of
It is possible to flow a sense current directly from the electrode layer 18 to the multilayer film 16.

As described above, according to the present invention, the contact thickness h2 of the electrode layer 18 formed on and in contact with the multilayer film 16 can be formed thin, so that the step between the upper surface of the electrode layer 18 and the upper surface of the multilayer film 16 is reduced. Accordingly, the step coverage of the upper gap layer 79 formed from the electrode layer 18 to the multilayer film 16 can be improved and the upper gap layer 79 can be formed without occurrence of film breakage, and sufficient insulation can be ensured.

However, it is not true that the electrode layer 18 may be formed on the multilayer film 16 so as to extend as far as possible.
As shown in FIG. 1, a width dimension T located at the center of the multilayer film 16 is shown.
The area 2 is the sensitivity area E, and the areas with the width dimension T1 on both sides thereof are the insensitive areas D and D.

In the sensitivity region E, the magnetization of the fixed magnetic layer 12 is properly fixed in the Y direction in the drawing, and the magnetization of the free magnetic layer 14 is properly aligned in the X direction in the drawing. The magnetization of the free magnetic layer 14 has an orthogonal relationship. In the sensitivity region E, the magnetization of the free magnetic layer 14 fluctuates with high sensitivity to an external magnetic field from the recording medium, that is, the sensitivity region E is a portion where the magnetoresistance effect can be substantially exerted.

On the other hand, in the insensitive regions D, D located on both sides of the sensitive region E, the magnetizations of the fixed magnetic layer 12 and the free magnetic layer 14 are strongly influenced by the magnetization from the hard bias layer 17, and The magnetization of the free magnetic layer 14 is hardly fluctuated by an external magnetic field. That is, the dead area D is an area where the magnetoresistance effect is weak and the reproduction function is reduced.

In the present invention, the width T2 of the sensitive region E and the width of the insensitive regions D and D in the multilayer film 16 are measured by the above-described microtrack profile method (see FIG. 11).

In the present invention, as shown in FIG.
Is formed to extend over the dead area D of the multilayer film 16 with a width of T3. The width of the upper surface of the multilayer film 16 which is not covered with the electrode layer 18 is an optical track width O-Tw (Optical) measured by an optical method.
read track width).

The width T2 of the sensitivity region E whose upper surface is not covered with the electrode layer 18 substantially functions as a track width, and the width T2 is a magnetic track width M-Tw.
(Magnetic read track width).
In the embodiment shown in FIG. 1, the optical track width dimension OT
w, the magnetic track width dimension M-Tw, and the width dimension T2 of the sensitivity region E all have substantially the same dimension value.

As described above, in the present invention, the electrode layer 18 overlapping the multilayer film 16 is formed to extend over the dead area D. Therefore, the electrode layer 18
, Avoiding the insensitive region D and easily flowing to the sensitive region E where the magnetoresistive effect can be substantially exerted, and it is possible to further improve the reproduction output.

In particular, the optical track width O-Tw and the width T2 of the sensitivity region E (= magnetic track width M-T)
In the case where w) is formed with the same width, the sense current can easily flow appropriately to the sensitivity region E, and the reproduction characteristics can be further improved.

In the embodiment shown in FIG. 1, the electrode layer 18
However, although the electrode layer 18 is formed so as to completely cover the dead area D, the electrode layer 18 may not completely cover the dead area D, and a part of the dead area D is exposed. Is also good. In this case, the width of the optical track width O-Tw is larger than the width dimension T2 of the sensitivity region E (= magnetic track width M-Tw). However, the electrode layers 18 formed on the multilayer film 16 must not be formed on the sensitivity region D.

Since the sense current mainly flows from the tip of the electrode layer 18 formed on the upper surface of the multilayer film 16, as described above, the sensitivity region where the magnetoresistive effect can be substantially exerted is provided. In the case where the electrode layer 18 is formed even on the electrode E, the sense current hardly flows through the sensitivity region E where the electrode layer 18 is covered, and the sensitivity region E where the angle and the magnetoresistive effect can be favorably exhibited can be obtained. Will kill some,
This leads to generation of noise and a decrease in reproduction output, which is not preferable.

The multilayer film 22 of the spin-valve thin film element shown in FIG. 2 is obtained by reversing the stacking order of the multilayer film 16 of the spin-valve thin film element shown in FIG. That is, FIG.
In this example, a free magnetic layer 14, a nonmagnetic conductive layer 13, a pinned magnetic layer 12, and an antiferromagnetic layer 20 are sequentially stacked on an underlayer 19.

In this embodiment, since the free magnetic layer 14 of the multilayer film 22 shown in FIG. 2 is formed below the antiferromagnetic layer 20, the hard bias layers 17, 17 are formed.
Therefore, the magnetization of the free magnetic layer 14 can be easily aligned in the X direction. Thereby, generation of Barkhausen noise can be reduced.

Also in this embodiment, the electrode layer 1 is provided between the hard bias layer 17 and the electrode layer 18.
An intermediate layer 21 made of a high-resistance material or an insulating material having a resistance value higher than 8 is provided to suppress the shunt of the sense current to the hard bias layer 17. As in FIG. 1, nonmagnetic material layers 23 and 24 made of Ta or the like may be provided above and below the intermediate layer 21.

The electrode layer 18 is formed so as to extend on the multilayer film 22.
Reference numeral 8 is formed to extend over the dead area D of the multilayer film 22 with a width dimension of T5.

In this embodiment, the multilayer film 22 is composed of the free magnetic layer 14, the nonmagnetic conductive layer 13, the fixed magnetic layer 1
2 and the antiferromagnetic layer 20 are stacked in this order, so that the sense current flowing from the electrode layer 18 formed on the multilayer film 22 to the nonmagnetic conductive layer 13 is
3 and the fixed magnetic layer 12 and the antiferromagnetic layer 20
The amount of sense current flowing to the nonmagnetic conductive layer 13 may be lower than that in the embodiment shown in FIG. 1 in which only the free magnetic layer 14 is formed on the nonmagnetic conductive layer 13. .

However, also in the case of this embodiment, the intermediate layer 21 is formed between the hard bias layer 17 and the electrode layer 18, and the shunt of the sense current to the hard bias layer 17 is suppressed. Since the layer 18 is extended on the multilayer film 22, a sense current can flow directly from the electrode layer 18 to the multilayer film 22, and the electrode layer 18 extends on the dead area D. Since the sense current can flow preferentially to the sensitivity region E, the multilayer film 9 in the conventional magnetoresistive element shown in FIG. Compared with the case where the layer 2 and the antiferromagnetic layer 1 are stacked in this order, the reproduction sensitivity can be increased and the reproduction output can be improved.

Further, the contact thickness h5 of the electrode layer 18 with respect to the multilayer film 22 can be reduced by the presence of the intermediate layer 21, so that the step formed between the upper surface of the electrode layer 18 and the upper surface of the multilayer film 22 can be reduced. And therefore the electrode layer 1
The step coverage of the upper gap layer 79 formed on the multilayer film 22 from above 8 can be improved without breaking the film, and sufficient insulation can be ensured.

FIG. 3 is a cross-sectional view of the structure of another magnetoresistive element according to the present invention as viewed from the ABS. In the spin-valve thin film element shown in FIG. 3, an antiferromagnetic layer 30 formed on an underlayer 19 is formed to be long in the X direction in the drawing, and the antiferromagnetic layer 30 has a height dimension at the center in the X direction. It is formed to protrude by d1. And this protruding antiferromagnetic layer 30
A fixed magnetic layer 31, a nonmagnetic conductive layer 32, a free magnetic layer 33, and a protective layer 15 are formed thereon, and a laminate from the underlayer 19 to the protective layer 15 is configured as a multilayer film 35.

In the present invention, the antiferromagnetic layer 30 is made of Pt--Mn
It is formed of a (platinum-manganese) alloy film. Alternatively, instead of the Pt-Mn alloy, X-Mn (where X
Is one or more of Pd, Ir, Rh, and Ru, or Pt-Mn-X '(where X' is Pd, Ir, Rh, Ru, Au, Ag) (Any one or two or more elements).

The fixed magnetic layer 31 and the free magnetic layer 3
3 is a Ni-Fe (nickel-iron) alloy, Co (cobalt), Fe-Co (iron-cobalt) alloy, Fe-Co-
The nonmagnetic conductive layer 32 is formed of a Ni alloy or the like.
Is formed of a nonmagnetic conductive material having a low electric resistance such as Cu (copper).

As shown in FIG. 3, the pinned magnetic layer 31, the nonmagnetic conductive layer 32, and the free magnetic layer 33 are arranged on the width T8 of the antiferromagnetic layer 30 extending in the X direction. A metal film 36 serving as a buffer film and an alignment film formed of Cr or the like is formed over the side surface of the hard bias layer 3 to be described later.
7 can be increased.

Further, on the metal film 36, for example, C
o-Pt (cobalt-platinum) alloy or Co-Cr-Pt
A hard bias layer 37 made of a (cobalt-chromium-platinum) alloy or the like is formed.

As described above, in the embodiment shown in FIG. 3, the hard bias layer 37 is formed on the antiferromagnetic layer 30, and the thickness of the hard bias layer 37 in the portion formed on both sides of the free magnetic layer 33 is as follows. 1 or 2, the free magnetic layer 3 is thicker than the spin-valve thin film element shown in FIG.
3, the bias magnetic field from the hard bias layer 37 can be sufficiently applied, and the free magnetic layer can be easily made to have a single magnetic domain in the X direction.

The hard bias layers 37, 37 are formed of a high-resistance material or an insulating material having a higher resistance than the electrode layer 39 via the nonmagnetic material layers 25, 25 of Ta or the like. The intermediate layer 38 is formed, and the nonmagnetic material layers 26, 26 such as Ta are formed on the intermediate layer 38.
Electrode layers 39, 39 made of Ta, Cr, etc.
Are formed.

Also in this embodiment, the hard bias layer 3
By providing an intermediate layer 38 made of a high-resistance material or an insulating material between the electrode layer 39 and the electrode layer 39, it is possible to suppress the shunt of the sense current to the hard bias layer 37. 35, the multilayer film 35 and the electrode layer 39 can be electrically connected to each other on the multilayer film 35. 35, hard bias layer 37
Thus, the sense current can be passed directly without passing through, and the reproduction sensitivity can be increased and the reproduction output can be improved.

As shown in FIG. 3, the region of the multilayer film 35 having the width dimension T9 is the sensitivity region E, and the region having the width dimension T10 is the dead region D. In the present invention, the electrode layer 39 is formed of the dead region D. Since it is formed to extend upward, the sense current from the electrode layer 39 can flow preferentially to the sensitivity region E, and the reproduction output can be further improved.

In FIG. 3, the electrode layer 39 formed on the multilayer film 35 does not completely cover the insensitive area D and is formed with a shorter width T11. As described above, the insensitive area D may be completely covered.

As shown in FIG. 3, when the electrode layer 39 formed on the multilayer film 35 does not completely cover the dead area D, the upper surface of the multilayer film 35 on which the electrode layer 39 is not formed is formed. Optical track width dimension O- defined as width dimension
Tw is the sensitivity region E where the upper surface is not covered with the electrode layer 39.
Is larger than the magnetic track width dimension M-Tw determined by the width dimension.

Also in this embodiment, the contact thickness h6 of the electrode layer 39 with the multilayer film 35 can be reduced by the presence of the intermediate layer 38, so that the electrode layer 39 is formed between the upper surface of the electrode layer 39 and the upper surface of the multilayer film 35. Thus, the step coverage of the upper gap layer 79 formed on the multilayer film 35 from the electrode layer 39 can be improved and the step can be formed without occurrence of film breakage, and sufficient insulation can be secured. It is possible.

FIG. 4 is a sectional view of the structure of another magnetoresistive element according to the present invention as viewed from the ABS. This spin-valve thin-film element has a nonmagnetic conductive layer 43, 45 and fixed magnetic layers 42, 4 above and below a free magnetic layer 44.
6, and a so-called dual spin-valve thin-film element in which antiferromagnetic layers 41 and 47 are formed. The spin-valve thin-film element shown in FIGS. 1 to 3 (called a single spin-valve thin-film element) It is possible to obtain a higher reproduction output. The lowermost layer is the underlayer 19, the uppermost layer is the protective layer 15, and the multilayered film 48 is composed of a laminate from the underlayer 19 to the protective layer 15. I have.

In the present invention, the antiferromagnetic layers 41 and 47 are made of Pt.
-Mn (platinum-manganese) alloy film. Alternatively, instead of the Pt-Mn alloy, X-Mn
(Where X is any one or more of Pd, Ir, Rh, and Ru) or Pt-Mn
-X '(where X' is Pd, Ir, Rh, Ru, A
u or Ag is one or more elements)
May be formed.

The fixed magnetic layers 42 and 46 and the free magnetic layer 44 are made of a Ni—Fe (nickel-iron) alloy,
(Cobalt), Fe-Co (iron-cobalt) alloy, Fe
The nonmagnetic conductive layers 43 and 45 are formed of a nonmagnetic conductive material having low electric resistance such as Cu (copper).

As shown in FIG. 4, hard bias layers 49, 49 are formed on both sides of the multilayer film 48. The hard bias layers 49, 49 are made of, for example, a Co-Pt (cobalt-platinum) alloy or a Co-Pt alloy. -Cr-Pt (cobalt-chromium-platinum) alloy or the like.

The hard bias layers 49, 49 are shown in FIG.
The magnetization of the free magnetic layer 44 is aligned in the X direction in the figure by a bias magnetic field in the X direction from the hard bias layers 49, 49.

On the hard bias layers 49, 49, for example, TaSiO ₂ , TaSi, CrSiO ₂ , CrSi, W
An electrode layer 51 of Si, WSiO ₂ , TiN, TaN or the like;
A high-resistance material having a resistance value higher than the resistance of 51, or Al ₂ O ₃ , SiO ₂ , Ti ₂ O ₃ , TiO, WO, A
Intermediate layers 50, 50 made of an insulating material such as 1N, Si ₃ N ₄ , B ₄ C, SiC, and SiAlON are formed, and a non-magnetic material layer such as Ta is formed on the intermediate layers 50, 50. The electrode layers 51, 51 made of Ta, Cr, or the like are formed via the layers 28, 28. The electrode layer 5
The reference numerals 1 and 51 extend to the upper surface of the multilayer film 48 as shown in FIG.

In the present invention, the intermediate layer 5 made of a high resistance material or an insulating material is provided between the hard bias layer 49 and the electrode layer 51.
By interposing 0, the shunt of the sense current to the hard bias layer 49 can be suppressed, and since the electrode layer 51 is formed to extend to the upper surface of the multilayer film 48, the electrode layer 51 This allows a sense current to flow directly to the device, thereby increasing the reproduction sensitivity and improving the reproduction output.

In the present invention, even if the contact thickness h3 of the electrode layer 51 with the multilayer film 48 is reduced due to the presence of the intermediate layer 50, the hard bias layer 49 can be effectively transferred from the electrode layer 51 to the multilayer film 48. Since a sense current can flow without any intervention, the step between the upper surface of the electrode layer 51 and the upper surface of the multilayer film 48 can be reduced. The film can be formed without occurrence of film breakage by improving coverage, and sufficient insulation can be ensured.

Also in this embodiment, the sensitivity region E and the insensitive region D of the multilayer film 48 are measured by the microtrack profile method, but the width dimension located at the center of the multilayer film 48 as shown in FIG. The region T15 is the sensitivity region E, and the region with the width dimension T14 on both sides thereof is the dead region D.

In the sensitivity region E, the fixed magnetic layers 42, 4
6, the magnetization of the free magnetic layer 44 is properly aligned in the illustrated X direction, and the magnetizations of the fixed magnetic layers 42 and 46 and the free magnetic layer 44 are orthogonal to each other. is there. Then, the magnetization of the free magnetic layer 44 fluctuates with high sensitivity to an external magnetic field from the recording medium, and the electrical resistance changes due to the relationship between the fluctuation of the magnetization direction and the fixed magnetization directions of the fixed magnetic layers 42 and 46. The leakage magnetic field from the recording medium is detected by the voltage change based on the change in the electric resistance value.

In the present invention, as shown in FIG.
The electrode layer 51 formed thereon is formed to extend over the dead area D with a width dimension T16. The electrode layers 51, 5
1 is defined as the optical track width O-Tw, and the width T of the sensitivity region E whose upper surface is not covered with the electrode layer 51 is defined as O-Tw.
15 is defined as the magnetic track width dimension M-Tw. In this embodiment, for example, the multilayer film 48 is used.
The electrode layer 51 extended upward completely covers the dead area D. In this case, the optical track width O-Tw and the magnetic track width dimension M-Tw (= the width dimension of the sensitivity region E)
Have approximately the same width.

Alternatively, the electrode layer 51 may not completely cover the dead area D. The width dimension T15 of the electrode layer 51 extended on the multilayer film 48 is formed shorter than the dead area D. Is also good. In this case, the optical track width OT
w becomes larger than the magnetic track width M-Tw. As a result, in the present invention, the sense current from the electrode layer 51 can be preferentially passed to the sensitivity region E, and the reproduction output can be further improved.

FIG. 5 is a sectional view of another magnetoresistive element according to the present invention as viewed from the ABS side. The magnetoresistive element shown in FIG. 5 is an AMR (amisotropic magnetoresi
A soft magnetic layer (SAL layer) 52, a nonmagnetic layer (SHUNT layer) 53, a magnetoresistive layer (MR layer) 54, and a protective layer 55 are laminated in this order from the bottom. This is a multilayer film 61. Hard bias layers 56, 56 are formed on both sides of the multilayer film 61. Generally, a NiFeNb alloy film is used for the soft magnetic layer 52, a Ta film is used for the nonmagnetic layer 53, a NiFe alloy film is used for the magnetoresistive layer 54, and a CoPt alloy film is used for the hard bias layer 56.

On the hard bias layers 56, 56, for example, TaSiO ₂ , TaSi, CrSiO ₂ , CrSi, W
An electrode layer 58 of Si, WSiO ₂ , TiN, TaN or the like;
A high-resistance material having a resistance value higher than the resistance of 58, or Al ₂ O ₃ , SiO ₂ , Ti ₂ O ₃ , TiO, WO, A
Intermediate layers 57, 57 made of an insulating material such as 1N, Si ₃ N ₄ , B ₄ C, SiC, and SiAlON are formed, and a non-magnetic material layer such as Ta is formed on the intermediate layers 57, 57. The electrode layers 58, 58 made of Ta, Cr, or the like are formed via 62, 62. The electrode layers 58 extend to the upper surface of the multilayer film 61 as shown in FIG.

In this AMR element, the hard bias layer 5
6 are magnetized in the X direction in the figure, and a bias magnetic field in the X direction is applied to the magnetoresistive layer 54 by the hard bias layer 56. Further, a bias magnetic field in the illustrated Y direction is applied from the soft magnetic layer 52 to the magnetoresistive layer 54. Magnetoresistive layer 5
By applying a bias magnetic field in the X direction and the Y direction to 4, a change in magnetization with respect to a change in the magnetic field of the magnetoresistive layer 54 is set to have a linear state. The running direction of the recording medium is the Z direction. When a leakage magnetic field from the recording medium is applied in the Y direction, the magnetization direction of the magnetoresistive layer 54 changes, thereby changing the resistance value. This is detected as a voltage change. You.

In the present invention, the intermediate layer 5 made of a high resistance material or an insulating material is provided between the hard bias layer 56 and the electrode layer 58.
7, the shunt of the sense current to the hard bias layer 56 can be suppressed, and the electrode layer 58 is formed to extend to the upper surface of the multilayer film 61. The sense current can flow directly to the

In particular, in the present invention, since a sense current can flow from the electrode layer 58 formed on the multilayer film 61 to the multilayer film 61, the uppermost magnetic layer of the multilayer film 61 is formed. The ratio of the sense current flowing to the resistive layer 54 can be increased, and the shunt of the sense current to the soft magnetic layer 52, which has been a problem in the past, can be suppressed. The reproduction output can be improved.

In the present invention, even if the thickness h4 of contact of the electrode layer 58 with the multilayer film 61 is reduced due to the presence of the intermediate layer 57, the hard bias layer 56 does not pass from the electrode layer 58 to the multilayer film 61. In addition, since the sense current can be effectively passed, the contact thickness h4 of the electrode layer 58 with the multilayer film 61 can be reduced, and the step between the upper surface of the electrode layer 58 and the upper surface of the multilayer film 61 can be reduced. The step coverage of the upper gap layer 79 formed on the multilayer film 61 from the layer 58 can be improved and the upper gap layer 79 can be formed without occurrence of film breakage, and sufficient insulation can be ensured.

Also in this embodiment, the sensitivity region E and the insensitive region D of the multilayer film 61 are measured by the microtrack profile method, and the region of the width dimension T19 located at the center of the multilayer film 61 is the sensitivity region E. A region having a width dimension T20 located on both sides thereof is a dead region D. In the present invention, as shown in FIG. 5, the electrode layer 58 formed on the multilayer film 61 is formed so as to extend over the dead area D with a width dimension T21.

The width of the upper surface of the multilayer film 61 not covered by the electrode layers 58, 58 is the optical track width O-Tw.
The width dimension T19 of the sensitivity region E whose upper surface is not covered with the electrode layer 58 is defined as a magnetic track width dimension M-Tw. In this embodiment, for example, the electrode layer 5 extended on the multilayer film 61 is used.
8 completely covers the dead area D. In this case, the optical track width O-Tw and the width dimension T19 of the sensitivity region E
(= Magnetic track width dimension M−Tw) is almost the same width dimension.

Alternatively, the electrode layer 58 may not completely cover the dead area D, and the width dimension T21 of the electrode layer 58 extended on the multilayer film 61 is formed shorter than the dead area D. Is also good. In this case, the optical track width OT
w becomes larger than the magnetic track width M-Tw.

In the present invention, the electrode layer 58 is formed as a multilayer film 61.
Is formed so as to extend over the insensitive region D, the sense current can be preferentially passed through the magnetoresistive layer 54 in the sensitive region E, so that the reproduction output can be further improved.

Next, a method of manufacturing a magnetoresistive element according to the present invention will be described with reference to the drawings. First, FIG.
As shown in (1), a multilayer film 71 of a magnetoresistive element is formed on a substrate 70. The multilayer film 71 may be a multilayer film of a single spin valve thin film element shown in FIGS. 1 and 2, a multilayer film of a dual spin valve thin film element shown in FIG. 4, or a multilayer film of an AMR element shown in FIG. There may be. Also, as in the spin valve type thin film element shown in FIG.
To form the antiferromagnetic layer 30 long in the X direction shown in FIG.
In the step of removing the side surface of the multilayer film 71 by etching as shown in (3), the etching rate and the etching time may be controlled so that the side surface of the antiferromagnetic layer 30 remains without being removed. When the multilayer film 71 is formed of a single spin-valve thin film element or a dual spin-valve thin film element, the antiferromagnetic layer constituting the multilayer film 71 is
It is preferably formed of a PtMn alloy, or X
-Mn (where X is one or more elements of Pd, Ir, Rh, Ru) or Pt-M
nx '(where X' is Pd, Ir, Rh, Ru, A
u or Ag is one or more elements)
May be formed. When the antiferromagnetic layer is formed of the above-described material, heat treatment must be performed to generate an exchange coupling magnetic field at the interface with the fixed magnetic layer.

Then, as shown in FIG. 11, a conventional magnetoresistive element in which hard bias layers and electrode layers are formed only on both sides of the multilayer film is used in advance.
The width dimension A of the upper surface of the multilayer film of this magnetoresistive element is measured with an optical microscope. Next, the magnetoresistive element is
A small signal on which a certain signal is recorded is scanned in the track width direction to detect a reproduction output, and of the reproduction output, an area having a width B of the upper surface which emits a reproduction output of 50% or more of the maximum output is detected. A region having a sensitivity region E and a width C of the upper surface that emits a reproduction output of 50% or less of the maximum output is defined as a dead region D.

On the basis of the measurement results, a lift-off resist layer 72 is formed on the multilayer film 71 in consideration of the width C of the dead area D known in advance by the microtrack profile method. As shown in FIG. 6, the resist layer 72 has cut portions 72a, 7
2a are formed, but the cuts 72a, 72
a is formed on the insensitive region D in the multilayer film 71, and the resist layer 72 is completely covered on the sensitive region E in the multilayer film 71.

Next, in the step shown in FIG. 7, both sides of the multilayer film 71 are etched away, and in the step shown in FIG.
73 is formed. In the present invention, the hard bias layer 7
The sputtering method used in forming the films 3 and 73 and forming the intermediate layer 76 and the electrode layer 75 includes an ion beam sputtering method,
It is preferable to use any one or more of the long throw sputtering method and the collimation sputtering method.

As shown in FIG. 8, in the present invention, the multilayer film 71 is used.
Is formed in a direction perpendicular to the target 74 formed with the composition of the hard bias layer 73, and thereby the hard bias is applied to the multilayer film 71 from the direction perpendicular to the multilayer film 71 by using, for example, an ion beam sputtering method. Since the layer 73 can be formed, the hard bias layer 73 does not enter the cut portions 72a of the resist layer 72 formed on the multilayer film 71. As shown in FIG. 8, a layer 73a having the same composition as the hard bias layer 73 is also formed on the resist layer 72.

Further, the target 74 is, for example,
aSiO ₂ , TaSi, CrSiO ₂ , CrSi, WS
i, high resistance materials such as WSiO ₂ , TiN, TaN, or Al ₂ O ₃ , SiO ₂ , Ti ₂ O ₃ , TiO, WO,
Instead of the target 77 formed with the composition of the intermediate layer 76 made of an insulating material such as AlN, Si ₃ N ₄ , B ₄ C, SiC, or SiAlON, an intermediate layer is formed on the hard bias layers 73 and 73 by ion beam sputtering. The layers 76 are formed. Similarly to the hard bias layer 73, the intermediate layer 76 does not penetrate into the cut portions 72a, 72a of the resist layer 72 formed on the multilayer film 71. Then, as shown in FIG. 8, a layer 76a having the same composition as the intermediate layer 76 is also formed on the resist layer 72.

Next, in the step shown in FIG.
An electrode layer 75 is formed on the intermediate layer 76 from an oblique direction with respect to the electrode layer 75. At this time, the electrode layer 75 is formed in a cut portion 72a formed on the lower surface of the resist layer 72 provided on the multilayer film 71. Is formed.

For example, as shown in FIG. 9, the substrate 70 on which the multilayer film 71 is formed is ion beam sputtered while rotating the substrate 70 obliquely with respect to a target 78 formed with the composition of the electrode layer 75. The electrode layer 7
5 is formed on the hard bias layer 73. At this time, the electrode layer 75 sputtered from the oblique direction is not only on the intermediate layer 76 but also on the resist layer 7 formed on the multilayer film 71.
The film also penetrates into the second cut portion 72a and is formed. That is, the electrode layer 75 formed in the cut portion 72a
Is formed at a position covering the dead area D of the multilayer film 71.

In the step shown in FIG. 10, the resist layer 72 shown in FIG. 9 is removed by lift-off using a resist stripper, whereby the electrode layer 75 is formed on the dead area D of the multilayer film 71. The completed magnetoresistive element is completed.

[0124]

According to the present invention described in detail above, an intermediate layer formed of a high-resistance material having a higher resistance value than the electrode layer or an insulating material is provided between the hard bias layer and the electrode layer. By providing and further forming the electrode layer so as to extend on the multilayer film, the shunt of the sense current to the hard bias layer can be suppressed, and the sense current can flow directly from the electrode layer to the multilayer film. As a result, it is possible to increase the reproduction sensitivity and to improve the reproduction output as compared with the related art.

In the present invention, the contact thickness of the electrode layer with respect to the multilayer film can be reduced by the presence of the intermediate layer, so that the step formed between the upper surface of the electrode layer and the upper surface of the multilayer film can be reduced. Therefore, the step coverage of the upper gap layer formed from the electrode layer on the multilayer film can be improved, the film can be formed without breaking the film, and sufficient insulation can be secured.

Further, according to the present invention, by forming the electrode layer to be overlapped on the multilayer film so as to extend over the dead area occupying the vicinity of both sides of the multilayer film, the magnetic layer substantially occupying the central portion of the multilayer film is formed. The sense current can be preferentially supplied to the sensitivity region where the resistance effect can be exerted, so that the reproduction output can be further improved.

[Brief description of the drawings]

FIG. 1 is a partial sectional view showing a structure of a magnetoresistive element according to a first embodiment of the present invention;

FIG. 2 is a partial sectional view showing a structure of a magnetoresistive element according to a second embodiment of the present invention;

FIG. 3 is a partial sectional view showing a structure of a magnetoresistive element according to a third embodiment of the present invention;

FIG. 4 is a partial sectional view showing a structure of a magnetoresistive element according to a fourth embodiment of the present invention;

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

FIG. 6 is a process chart showing a method for manufacturing a magnetoresistive element according to the present invention;

7 is a process drawing performed after the step in FIG. 6,

8 is a process drawing performed after the step of FIG. 7,

9 is a process drawing performed after the step in FIG. 8,

10 is a process drawing performed after the step in FIG. 9,

FIG. 11 is a measurement diagram showing a method for measuring a sensitivity region E and a dead region D in a multilayer film of a magnetoresistive element,

FIG. 12 is a partial cross-sectional view showing the structure of a first conventional magnetoresistance effect element.

FIG. 13 is a partial cross-sectional view showing the structure of a second conventional magnetoresistive element.

[Explanation of symbols]

 20, 30, 41, 47 Antiferromagnetic layer 12, 31, 42, 46 Fixed magnetic layer 13, 32, 43, 45 Nonmagnetic conductive layer 14, 33, 44 Free magnetic layer 16, 22, 35, 48, 61, 71 Multilayer film 17, 37, 49, 56, 73 Hard bias layer 18, 39, 51, 58, 75 Electrode layer 21, 38, 50, 57, 76 Intermediate layer 36 Metal layer 52 Soft magnetic layer (SAL layer) 53 Non Magnetic layer (SHUNT layer) 54 Magnetoresistive layer (MR layer) 72 Lift-off resist layer 72a Cutout 74, 77, 78 Target D Dead area E Sensitivity area M-Tw Magnetic track width O-Tw Optical track width

Claims (12)

[Claims] 1. An antiferromagnetic layer, a fixed magnetic layer formed in contact with the antiferromagnetic layer and having a magnetization direction fixed by an exchange anisotropic magnetic field with the antiferromagnetic layer; And a free magnetic layer formed with a nonmagnetic conductive layer interposed therebetween, and formed on both sides of the multilayer film so that the magnetization direction of the free magnetic layer crosses the magnetization direction of the fixed magnetic layer. In a magnetoresistive element including a pair of bias layers to be aligned and a pair of conductive layers formed on the bias layer, a height higher than the electrode layer is between the hard bias layer and the electrode layer. An intermediate layer formed of a high-resistance material having resistance and / or an insulating material is provided, and the electrode layer is formed to extend over the multilayer film. Effect element. 2. The multilayer film is formed by stacking an antiferromagnetic layer, a fixed magnetic layer, a nonmagnetic conductive layer, and a free magnetic layer in this order from below, and the antiferromagnetic layer is formed on the antiferromagnetic layer. 2. The magnetoresistive effect according to claim 1, wherein the pair of bias layers, the intermediate layer, and the electrode layer are laminated via a metal film on the antiferromagnetic layers on both sides of each layer. element. 3. A free magnetic layer, a nonmagnetic conductive layer formed above and below the free magnetic layer, and formed on one nonmagnetic conductive layer and below the other nonmagnetic conductive layer, and have a magnetization direction. A multilayer film having a fixed magnetic layer fixed thereto, and an antiferromagnetic layer formed above one fixed magnetic layer and below the other fixed magnetic layer; formed on both sides of the multilayer film; A magnetoresistive element, comprising: a pair of bias layers for aligning a magnetization direction of a magnetic layer in a direction crossing a magnetization direction of the fixed magnetic layer; and a pair of conductive layers formed on the bias layer. An intermediate layer formed of a high-resistance material and / or an insulating material having a higher resistance than the electrode layer is provided between the hard bias layer and the electrode layer, and the electrode layer is formed of the multilayer film. Stretched out and formed A magnetoresistive effect element. 4. The magnetoresistance effect element according to claim 1, wherein said antiferromagnetic layer is formed of a PtMn alloy. 5. An antiferromagnetic layer comprising X-Mn (X
Is an alloy of one or more of Pd, Ir, Rh, and Ru). The magnetoresistive element according to any one of claims 1 to 3, wherein the alloy is formed of an alloy. 6. The antiferromagnetic layer is made of Pt—Mn—X ′.
(Where X 'is Pd, Ir, Rh, Ru, Au, Ag
The magnetoresistive element according to any one of claims 1 to 3, wherein the magnetoresistive element is formed of an alloy. 7. A multilayer film having a magneto-resistance effect layer and a soft magnetic layer stacked with a non-magnetic layer interposed therebetween, a pair of bias layers formed on both sides of the multilayer film, and In a magneto-resistance effect element having a pair of electrode layers formed, a high-resistance material and / or an insulating material having a higher resistance than the electrode layer is provided between the hard bias layer and the electrode layer. A magnetoresistive element, wherein a formed intermediate layer is provided, and the electrode layer is formed to extend over the multilayer film. 8. A high resistance material constituting an intermediate layer formed between the hard bias layer and the electrode layer includes TaSi
O ₂ , TaSi, CrSiO ₂ , CrSi, WSi, WS
8. The magnetoresistive element according to claim 1, wherein one or more of iO ₂ , TiN, and TaN are selected. 9. An insulating material constituting an intermediate layer formed between the hard bias layer and the electrode layer includes Al ₂ O ₃ ,
SiO ₂ , Ti ₂ O ₃ , TiO, WO, AlN, Si
_{3 N 4, B 4 C,} SiC, any of SiAlON 1
The magnetoresistive element according to claim 1, wherein one or more species are selected. 10. The multilayer film according to claim 1, wherein said multilayer film is excellent in reproduction sensitivity and has a central sensitivity region capable of substantially exhibiting a magnetoresistance effect;
It is formed on both sides of the sensitivity region, and comprises a dead region where reproduction sensitivity is bad and cannot substantially exhibit a magnetoresistive effect, and the electrode layer is formed to extend over the dead region. The magnetoresistive element according to claim 1. 11. The sensitivity region of the multilayer film is determined when a magnetoresistive element having electrode layers formed only on both sides of the multilayer film is scanned in a track width direction on a minute track on which a certain signal is recorded. , 5 of the maximum output among the obtained reproduction outputs
The dead area of the multilayer film is defined as an area where an output of 0% or more is obtained.
The magnetoresistive element according to claim 10, wherein the output is defined as a region where the output is 50% or less of the maximum output. 12. The magnetoresistive element according to claim 10, wherein the optical track width O-Tw is formed to have the same width as the sensitivity region.