JPH09129945A - Magnetoresistive element and method of manufacturing the same - Google Patents

Abstract

(57) Abstract: An object of the present invention is to provide a magnetoresistive effect element which suppresses dielectric breakdown at a lead edge portion and has improved reliability. As shown in FIG. 1B, a lead (2), a magnetic gap layer (3) and a magnetic shield layer (4) are laminated on a magnetoresistive effect film (1). At this time, the insulating film (5) is formed on the main surface of the edge portion of the lead (2), that is, the surface not processed into a taper shape, so that the film quality deterioration region of the magnetic gap layer (3) (indicated by a dotted line in the figure). Since the enclosed area A) is different from the electric field concentrated portion (the area B enclosed by the dotted line in the figure), dielectric breakdown is extremely unlikely to occur. That is, by providing the insulating film on the edge portion of the lead, the lower corner portion of the magnetic gap layer becomes the edge portion of the insulating film. Although the deterioration of the film quality at this portion is unavoidable, since the electric field concentrated portion is still the edge portion of the lead, the film quality deteriorated portion and the electric field concentrated portion are separated from each other, so that dielectric breakdown is less likely to occur.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetoresistive effect element used for a reproducing head of a magnetic disk device (HDD) and a method for manufacturing the same.

[0002]

2. Description of the Related Art An anisotropic magnetoresistive effect (AMR) such as a NiFe alloy or a giant magnetoresistive effect (GM) utilizing spin-dependent scattering between adjacent magnetic layers via a nonmagnetic layer.
The magnetoresistive effect element using the magnetic field dependence of the electric resistance according to R) is considered to be applied to a reproducing head of a magnetic disk device because of its high sensitivity and the like.

A pair of leads for supplying a current are formed on the magnetoresistive film exhibiting the magnetoresistive effect. The part sandwiched between the leads becomes the magnetic field sensitive part. A magnetic shield layer is formed on the surface of the magnetic field sensitive section via a magnetic gap layer made of an insulator.

From the viewpoint of high density recording, a reproducing head used for an HDD or the like is required to have a thin magnetic gap layer, that is, a narrow gap. However, the magnetic gap layer formed by covering the leads and the magnetoresistive effect film becomes poor in film quality and deteriorates at the edge portions of the leads. Further, it is the edge portion of the lead that the electric field is concentrated between the magnetic shield layer and the lead. Therefore, since the film quality deteriorated portion of the magnetic gap layer, which is an insulator, and the electric field concentrated portion coincide with each other, dielectric breakdown easily occurs at this portion. Therefore, it is difficult to thin the magnetic gap layer.

Further, when an etching process such as lift-off is used in processing the leads, burrs are easily generated at the pattern edges, and it is desirable to use ion milling.
However, in the step of peeling the resist after milling, burrs are generated by the redeposition layer made of a mixture of the resist and the milling material, which may lead to dielectric breakdown.

[0006]

As described above, the deterioration of the film quality of the magnetic gap layer at the lead edge portion easily causes dielectric breakdown, resulting in a decrease in reliability of the magnetoresistive effect element. It was The present invention has been made in consideration of the above points, and an object of the present invention is to provide a magnetoresistive effect element that suppresses dielectric breakdown at the lead edge portion and has improved reliability.

[0007]

According to the present invention, a magnetoresistive effect film; a pair of leads for supplying a current to the magnetoresistive effect film; an insulating film formed at an edge portion of the leads facing each other; A magnetoresistive effect element comprising: a magnetic gap layer covering the surface of the magnetoresistive film between leads and the insulating film; and a magnetic shield layer formed on the magnetic gap layer.

That is, by providing the insulating film on the edge portion of the lead, the corner portion of the lower layer of the magnetic gap layer becomes the edge portion of the insulating film. Although the deterioration of the film quality at this portion is unavoidable, since the electric field concentrated portion is still the edge portion of the lead, the film quality deteriorated portion and the electric field concentrated portion are separated from each other, so that dielectric breakdown is less likely to occur.

1 (a) and 1 (b) are schematic views of the essential part of the magnetoresistive effect element. FIG. 1 (a) does not have an insulating film (reference example), and leads (2) are formed on the magnetoresistive film (1).
The magnetic gap layer (3) and the magnetic shield layer (4) are laminated. In this state, the film quality deterioration area of the magnetic gap layer at the edge portion of the lead (the portion surrounded by the dotted line in the figure) coincides with the electric field concentration portion of the lead, that is, the corner of the conductor portion, and dielectric breakdown occurs in this area. Easy to get up.

On the other hand, as shown in FIG. 1B (the present invention), the insulating film (5) is formed on the main surface of the edge portion of the lead (2), that is, on the surface which is not tapered. Since the film quality deterioration region (region A surrounded by a dotted line in the drawing) of the magnetic gap layer (3) is different from the electric field concentrated portion (region B surrounded by a dotted line in the drawing), the dielectric breakdown is extremely unlikely to occur. .

The present invention also provides a method of implementing this structure. That is, the step of forming a conductor layer on the magnetoresistive film; the first step of forming a mask layer of an insulating layer on the conductor layer in a predetermined pattern; and the conductor by ion milling using the mask layer. A second step of processing the layer into a lead shape; and a third step of forming a magnetic gap layer made of a non-magnetic material so as to cover the magnetoresistive effect film exposed by the second step and the remaining mask layer. A method of manufacturing a magnetoresistive effect element, comprising: a step; and a fourth step of forming a magnetic shield layer made of a magnetic material on the magnetic gap layer.

Since the mask layer remains after the magnetic gap layer is formed, the film quality deterioration portion and the electric field concentration portion of the magnetic gap layer can be separated from each other as described above, and the dielectric breakdown hardly occurs.

[0013]

The magnetoresistive film used in the present invention can be applied to both AMR and GMR. Examples of AMR include a permalloy thin film, and examples of GMR include a laminated film of a ferromagnetic layer / a conductive nonmagnetic layer (Cu, Au, Ag, etc.). Examples of the GMR type include a so-called metal artificial lattice type having antiferromagnetic exchange coupling between adjacent ferromagnetic layers, and a so-called spin valve type having substantially no exchange coupling between adjacent ferromagnetic layers.

Among them, the GMR type magnetoresistive film has a large MR value and is effective. Co, Fe, Ni and alloys thereof can be used for the magnetic layer that constitutes the sandwich structure. Furthermore, Pd, Al, Cu,
Ta, In, B, Nb, Hf, Mo, W, Re, Ru,
A non-magnetic element such as Rh, Ga, Zr, Ir, Au, Ag or the like may be added. Cu, Au, Ag as the non-magnetic layer
Etc. can be used.

Particularly when a magnetic alloy of Co100-x Fex (0 <x≤40 atomic%) is used, the MR value is specifically large and effective. The spin valve type has a pinned layer whose magnetization is hard to rotate by a signal magnetic field and a free layer which is easily rotated. In this case, Co100-x Fex (0 <
It is particularly effective when a magnetic alloy of x ≦ 40 atomic% is used. When a Co alloy is used, the heat resistance is also excellent, and as disclosed in JP-A-6-325934 (1
11) The orientation can improve the sensitivity.

Generally, the magnetoresistive effect film is provided with a magnetic bias layer for the purpose of Barkhausen noise reduction, control of the direction of magnetization, etc., and the present invention allows the presence of the magnetic bias layer. Therefore, the lead does not have to be directly formed on the film having a magnetoresistive effect, and a conductive film, for example, a conductive magnetic bias layer may be interposed between this film and the lead. In any case, the effect of separating the film quality deterioration portion and the electric field concentration portion of the magnetic gap layer is the same.

For the magnetic bias layer, FeMn, Ir
A magnetic bias can be applied by magnetic exchange coupling using an antiferromagnetic film such as Mn. It is also possible to apply a magnetic bias using a method using a hard magnetic film having a high coercive force such as CoPt or a magnetic layer connected to the hard magnetic layer, for example, an amorphous magnetic alloy or permalloy.

For example, in the case of the spin valve type, an antiferromagnetic film is used for the magnetic bias layer for pinning the magnetization of the pinned layer,
A configuration using a magnetic layer connected to the hard magnetic layer is considered for controlling the magnetization direction of the free layer. With this, the magnetization direction of the pinned layer is set to the signal magnetic field direction in the absence of the signal magnetic field, and the magnetization direction of the free layer can be set to an initial state of 90 degrees with respect to the magnetization direction of the pinned layer.

The mask layer used in the method of the present invention is preferably one having excellent resistance to ion milling, and examples thereof include alumina. However, not limited to alumina, Al oxide, Si oxide, Ti oxide, Zr
Various materials such as oxide, aluminum nitride, silicon nitride, and tantalum nitride can be used.

Further, from the viewpoint of preventing step breakage at the lead edge portion of the film formed after the lead processing, it is preferable that the ion milling is performed at an angle of about 20 to 80 degrees from the perpendicular to the film surface to form a taper on the lead side surface. .

In this case, it is necessary to reduce the lead interval in response to the narrower track. However, if the mask layer is thicker than the lead interval, the shadow of the mask layer will affect the conductivity between the leads. The etching rate of the layer may be slower than that of the outer region, the leads may not be separated, and the characteristics of the magnetoresistive element may not be exhibited. Therefore, the film thickness of the mask layer needs to be set sufficiently smaller than the lead interval.

From the viewpoint of high-density recording such as 3 Gbpi or more, the lead interval is required to be about 1 μm or less.
It is desirable to set the thickness of the mask layer to about 300 nm or less. Further, since the residual film thickness after milling corresponds to the distance between the film quality deteriorated portion of the magnetic gap layer and the electric field concentrated portion, it is preferable to set the residual film thickness after milling to be about 5 nm or more.

The mask layer is not limited to one layer, and a laminated body can be used. For example, when alumina is used as the upper layer and silica is used as the lower layer, silica is more Cu than alumina.
Since it is close to the milling rate of the lead material such as, it is possible to obtain an effect that the shape after milling (the inclined surface formed by the mask layer and the lead) is gentle. In this case, only the upper alumina layer may be patterned as a mask.

As the lead, Cu, Au, Al, Mo,
A conductor such as MoTa alloy or MoW alloy may be used.
However, a laminated body having a layer of Cr, Ti, Ta, or the like on the surface may be used for the purpose of improving the adhesive strength with an adjacent layer and a barrier for preventing diffusion.

It suffices that the magnetic gap layer is non-magnetic and has a good electrical insulation property. For example, Si oxide, Zr oxide,
Inorganic oxides / nitrides such as Ti oxide, alumina, and aluminum nitride can be used. From the viewpoint of narrowing the gap, the film thickness is preferably about 100 nm or less.
However, in order to maintain good insulation, it is desirable to have a film thickness of at least about 10 nm or more.

Since the main surface of the lead has a two-layer structure of an insulating layer which is a residual mask layer and a magnetic gap layer, even if an unavoidable pinhole is formed when the thin film is formed, it is a two-layer structure. The possibility of short-circuiting between the shield layer and the lead is extremely low.

The magnetic shield layer may be a magnetic material having a high magnetic permeability and a high saturation magnetic flux density. For example, an amorphous magnetic alloy thin film can be used. By creating a coil etc. on this magnetic shield by a thin film process and making it a recording head,
It is also possible to form an integrated recording / playback head. An example is shown in FIGS. FIG. 9 is a schematic view of a recording / reproducing integrated head, in which a write head having a coil between upper and lower magnetic poles is formed on a magnetoresistive effect element sandwiched by upper and lower shields (FIG. 9A), alumina, etc. After forming the protective film of 1), it is processed into a slider shape (FIG. 9B). Further, the head is attached to the gimbal attached to the suspension to form a head gimbal assembly (FIG. 10). afterwards,
It will be incorporated into a magnetic disk.

[0028]

Embodiments of the present invention will be described below. (Embodiment 1) FIG. 2 is a schematic perspective view for explaining this embodiment, and FIGS. 3 (a) to 3 (c) are cross-sectional views of main parts.

A CoZrNb amorphous magnetic alloy layer having a thickness of 2 μm is formed as a lower shield layer (11) on a substrate (10) made of alumina / titanium carbide mixed ceramic (Altic). On this lower shield layer (11), an alumina layer having a thickness of 0.1 μm is formed as a lower gap layer (12).

A striped magnetoresistive film (13) is formed on the lower gap layer (12). This magnetoresistive film
(13) is, for example, a permalloy single layer film, a spin valve type magnetoresistive film having a sandwich structure of a ferromagnetic layer / a non-magnetic layer / a ferromagnetic layer, and the like.

A conductor layer (14) is formed on the magnetoresistive effect film (13). This conductor layer (14) is a 10 nm Ta layer (141), 80n
A Cu layer (142) of m and a Ta layer (143) of 20 nm are laminated in this order. The main body of the conductor layer (14) is the Cu layer (142), but the Ta layer (141) has the effect of improving the adhesive strength of the conductor layer (14) to the magnetoresistive effect film (13). Further, the Ta layer (142) has an effect of improving the adhesive strength between the mask layer (15) and the conductor layer (14) described later.

Next, 10 made of alumina is formed on the conductor layer (14).
A mask layer (15) having a thickness of 0 nm is formed. Reactive ion etching (RIE) using fluorocarbon gas
Patterning is performed to form leads having an interval of 1 μm (FIGS. 2 and 3 (a)). Even if RIE stops at the Ta layer, Cu
You may stop on the layer surface.

Next, by using this patterned alumina mask layer (15) by ion milling, a conductor layer is formed.
The (14) is processed into a lead (16). The ion incident angle was set to 40 degrees. After ion milling, the distance (t) between the conductor layers (14) in contact with the magnetoresistive film (13) was 1.0 μm.
The side surface of the formed lead (16) has a taper of about 45 degrees, and the residual film thickness of the mask layer (15) after ion milling is about 20.
It was nm (FIG.3 (b)). With this configuration, the top surface shape of the lead (16) and the shape of the mask layer (15) are substantially the same at least in the facing portion of the lead and near the edge of the lead.

The selection ratio of the mask material and the lead material can be controlled by selecting the milling angle, and as a result, the taper angle can be controlled. For example, in the case of an alumina mask and Ta lead, both have the same milling rate (at about 500 V) at an incident angle of 40 degrees, so that a taper angle of about 45 degrees can be obtained. Further, even if the mask is Si oxide, the lead is Cu and the milling angle is 60 degrees, a taper angle of about 45 degrees can be obtained, and the milling selection ratio with the Ti spin valve protective film can be about 3,
Both good taper angle and milling depth distribution can be achieved.

Next, an alumina layer having a thickness of about 60 nm is formed as the upper gap layer (17) [magnetic gap layer] to obtain a gap length (distance from the free layer to the upper shield layer) of 0.1.
We were able to achieve μm. At this time, since the residual mask layer (15) is used without being peeled off, no burr is generated due to peeling.

A CoZrNb amorphous magnetic alloy layer having a thickness of about 2.0 μm is formed thereon as an upper shield layer (18) [magnetic shield layer] (FIG. 3 (c)). The shield type MR head is obtained through the above steps. According to this configuration, the film quality deterioration portion of the magnetic gap layer is the edge portion of the residual alumina mask layer (15) and the electric field concentration region is the edge portion of the lead (16), and therefore, they do not coincide.

When the characteristics were evaluated using this reproducing head, it was found that the magnetic gap layer (17) on the magnetoresistive film was 60 nm.
Despite being thin, it was confirmed that the electrical insulation between the upper gap layer (17) and the magnetoresistive effect film (13) and the leads (16) was maintained well, which is extremely reliable. It was a thing. It was also confirmed that the reproduction track width was secured to be 1 μm.

A gap length of 0.1 μm could be realized even when the ion incident angle was 20 ° to 80 °. We were also able to change the conditions and achieve a playback track width of 0.7 μm. (Embodiment 2) FIG. 4 is a sectional view of an essential part.

On a substrate (not shown) as in Example 1,
The lower shield layer (21) is formed. An alumina layer having a thickness of 75 nm is formed as a lower gap layer (22) on the lower shield layer (21).

A stripe-shaped magnetoresistive film (23) is formed on the lower gap layer (22). This magnetoresistive film
(23) is a pinned layer (CoFe alloy 2 nm) (231) / non-magnetic layer (Cu3 nm) (232) / free layer (CoFe alloy 3n)
m) (233) sandwich structure (230) is formed in this order, and further 15 nm as a magnetic bias layer for the pinned layer (231).
The antiferromagnetic film (234) made of thick Ni oxide is the pinned layer (231)
A magnetic layer (235) made of CoZrNb amorphous magnetic alloy having a thickness of 10 nm is formed in contact with the free layer (233) as a magnetic bias layer for the free layer (233).

A conductor layer (24) is formed on the magnetoresistive effect film (23). The conductor layer (24) includes a CoPt layer having a thickness of 20 nm, a Cu layer (242) having a thickness of 80 nm, and a Ta layer (2 having a thickness of 20 nm) as a hard magnetic layer (241) for supplying a bias magnetic field to the magnetic layer (235).
43) are stacked in this order.

Then, as in Example 1, it is made of alumina.
A 100 nm thick mask layer (25) is formed, and the conductor layer (24) is processed by ion milling using the patterned alumina mask layer (25) to form leads (26). The ion incident angle was set to 40 degrees, and the gap between the conductor layers (24) in contact with the magnetoresistive effect film (23) was set to 1.0 μm. The side surface of the formed lead (26) was tapered at about 45 degrees, and the residual film thickness of the mask layer (25) after ion milling was about 20 nm.

Next, an alumina layer having a thickness of about 0.1 μm is formed as the upper gap layer (27) [magnetic gap layer]. About 2μ as an upper shield layer (28) [magnetic shield layer] on it
An m-thick CoZrNb amorphous magnetic alloy layer is formed.

A shield type MR head is obtained through the above steps (FIG. 4). When the characteristics were evaluated using this reproducing head, the upper gap layer (27), the magnetoresistive effect film (23) and the lead were read, although the magnetic gap layer was as thin as 0.1 μm.
It was confirmed that the electrical insulation between (26) was kept good, and it was very reliable. It was also confirmed that the reproduction track width was secured to be 1 μm. Further, since the leads and the hard magnetic film can be patterned by self-alignment, the positional relationship can be set strictly and the off-track characteristics are good.

(Embodiment 3) In Embodiment 2, the magnetoresistive film (2
Although the hard magnetic layer (24) is formed on the upper portion of 3), it may be formed on the lower portion.

5 and 6 are sectional views of the main part. A lower shield layer (31) is formed on a substrate (not shown) as in the first embodiment. An alumina layer having a thickness of about 0.1 μm is formed as a lower gap layer (32) on the lower shield layer (31). On this lower gap layer (32), a space (d) of 3 μm is formed as a hard magnetic layer (39).
To form a CoPt layer with a thickness of about 20 nm (FIG. 5A).

A magnetoresistive effect film (33) similar to that of the second embodiment is formed on the hard magnetic layer (39). The individual layer configurations are not shown. However, a magnetic layer is formed as a magnetic bias layer for the free layer in contact with this hard magnetic layer (FIG. 5B).

A conductor layer (34) is formed on the magnetoresistive effect film (33). This conductor layer (34) is Ta / C similar to that of the first embodiment.
It is a laminated film of u / Ta. Then, a mask layer (35) of alumina having a thickness of 100 nm is formed in the same manner as in Example 1 (see FIG.
(C)), a mask layer made of patterned alumina
The conductor layer (34) is processed by ion milling using (35) to form leads (36). Ion incident angle is set to 40 degrees,
Interval (t) between conductor layers (34) in contact with magnetoresistive film (33)
Is 1.0 μm, the side surface of the formed lead (36) has a taper of about 45 degrees, and the mask layer (3
The residual film thickness of 5) was about 20 nm (FIG. 5 (d)). The taper angle can be changed by changing the milling angle.

Next, an alumina layer having a thickness of about 60 nm is formed as the upper gap layer (37) [magnetic gap layer]. Approximately 2 μm as an upper shield layer (38) [magnetic shield layer] on it
A thick CoZrNb amorphous magnetic alloy layer is formed.

A shield type MR head is obtained through the above steps (FIG. 6). When the characteristics were evaluated using this reproducing head, the electrical gap between the upper gap layer (37) and the magnetoresistive effect film (33) and the leads (36) was found to be small even though the magnetic gap layer was as thin as 60 nm. It is confirmed that it is kept good,
It was very reliable. It was also confirmed that the reproduction track width was secured to be 1 μm. Also change the conditions
A 0.7 μm playback track was also realized.

(Embodiment 4) Similar to Embodiment 3, CoZrN
b Alumina lower gap of 0.1 μm is formed on the lower shield film. CoPt film 20nm is formed on it, and the interval is 2μm.
Then, ion milling is performed (FIG. 7A). Next, from the bottom as a spin valve film, CoZrNb 10 nm, CoFe2
nm, Cu3nm, CoFe2nm, FeMn15nm,
A spin valve protective film Ti 20 nm is formed. Further, after forming Ta20 nm, Cu80 nm, and Ta20 nm from the bottom as leads, an alumina mask of 100 nm is continuously formed (FIG. 7B). When the lead and the spin valve film can be continuously formed in the same device, Ta that contacts Ti is used.
Can be omitted.

Then, after processing the alumina mask by RIE in the same manner as in Example 1, the lead interval is set to 1 by ion milling.
It is processed to have a thickness of μm (FIG. 7C). Next, ion milling is performed by applying a resist mask having a shape in which tracks and leads are connected (FIGS. 8A and 8B). In this case, a normal organic resist or an inorganic insulating film such as alumina may be used.

Next, similarly to the first embodiment, the upper gap and the upper shield are formed (not shown). At this time, an adhesive layer for improving the adhesiveness of the gap layer may be interposed. For example, an amorphous Si layer of about 100 angstroms (A) (preferably about 50-150A) is formed on the spin valve side, and an amorphous Si layer of about 50A (preferably about 20-100A) is formed on the gap layer side.
An adhesive layer having _two layers can be interposed. In this case, the total film thickness of the adhesive layer and the gap layer (for example, the alumina layer) becomes a substantial gap layer film thickness, and therefore the alumina gap layer needs to be thinned by the thickness of the adhesive layer. An adhesive layer may be interposed in the lower gap as well.

In FIG. 7C and the subsequent drawings, the spin valve including the CoPt film is collectively shown. In addition to the effects shown in the above-mentioned embodiment, in this embodiment, since the spin valve is processed after the lead, it is possible to reduce the corrosion from the spin valve cross section or the CoPt step portion which occurs during the process. In addition, the contact resistance between the spin valve and the lead can be reduced, and the effect of improving the yield can be obtained.

Although ion milling is used in the embodiment described above, RIE (reactive ion etching),
Other methods such as CD (chemical dry etching) can also be adopted.

[0056]

As described above, according to the present invention, it is possible to obtain a highly reliable magnetoresistive effect element having high dielectric breakdown resistance. Therefore, a magnetic recording device (HD
In the case of D), a narrow gap and a narrow track can be realized, which is very effective, which is a great contribution to the industry.

[Brief description of the drawings]

FIG. 1 is a schematic diagram for explaining the present invention.

FIG. 2 is a schematic diagram for explaining the present invention.

FIG. 3 is a schematic process diagram for explaining the present invention.

FIG. 4 is a schematic sectional view for explaining the present invention.

FIG. 5 is a schematic process diagram for explaining the present invention.

FIG. 6 is a schematic sectional view for explaining the present invention.

FIG. 7 is a process schematic diagram for explaining the present invention.

FIG. 8 is a schematic process diagram for explaining the present invention.

FIG. 9 is a schematic diagram for explaining the present invention.

FIG. 10 is a schematic diagram for explaining the present invention.

[Explanation of symbols]

 Magnetoresistive film ・ ・ ・ 1,13,23,33 Lead ・ ・ ・ ・ 2,16,26,36 Insulating film ・ ・ ・ ・ ・ ・ 5,15,25,35 Magnetic gap layer ・ ・ ・ ・* 3,17,27,37 Magnetic shield layer ... 4,18,28,38

Claims (7)

[Claims] 1. A magnetoresistive effect film; a pair of leads for supplying a current to the magnetoresistive effect film; an insulating film formed at an edge portion of the leads facing each other; a magnetoresistive effect film between the leads. A magnetoresistive effect element comprising: a magnetic gap layer covering a surface and the insulating film; and a magnetic shield layer formed on the magnetic gap layer. 2. The magnetoresistive effect element according to claim 1, wherein the magnetoresistive effect film comprises a magnetic bias layer. 3. A step of forming a conductor layer on the magnetoresistive film; a first step of forming a mask layer of an insulating layer having a predetermined pattern on the conductor layer; ions using the mask layer A second step of processing the conductor layer into a lead shape by milling; forming a magnetic gap layer made of a non-magnetic material so as to cover the magnetoresistive effect film exposed by the second step and the remaining mask layer. A third step of doing;
A fourth step of forming a magnetic shield layer made of a magnetic material on the magnetic gap layer, and a method of manufacturing a magnetoresistive effect element. 4. The magnetoresistive film comprises a magnetic bias layer, and the magnetic bias layer is present on the surface of the magnetoresistive film exposed in the second step. Magnetoresistive element. 5. The mask layer comprises Al oxide, Si oxide,
4. The method of manufacturing a magnetoresistive effect element according to claim 3, comprising at least one selected from Ti oxide, Zr oxide, aluminum nitride, silicon nitride and tantalum nitride. 6. The mask layer thickness before ion milling is 30.
The method for producing a magnetoresistive effect element according to claim 3, wherein the thickness is 0 nm or less. 7. A method of manufacturing a magnetoresistive effect element according to claim 3, wherein the thickness of the mask layer remaining after ion milling is 5 nm or more.