JP3367161B2 - Method of manufacturing magnetoresistive head - Google Patents

Description

Detailed Description of the Invention

[0001]

The present invention relates to relates to a manufacturing <br/> method for producing the magnetoresistive heads used in magnetic recording device such as a magnetic disk device.

[0002]

2. Description of the Related Art There is a remarkable demand for miniaturization and large capacity in the magnetic recording field. For example, looking at a magnetic disk device, the disk diameter is decreasing from 3.5 inches to 2.5 inches, 1.8 inches,
The capacity per magnetic disk is also said to be 2.5 inches and 100 megabytes.

In order to meet these demands, a metal thin film disk having characteristics of high coercive force, high residual magnetic flux density and low noise has been developed as a magnetic disk. As a magnetic head, a metal in-gap head, a thin film head, and a metal magnetic film are used. Laminated laminated magnetic heads have been developed.

However, all of these magnetic heads utilize the phenomenon of electromagnetic induction, and the reproduction output thereof is proportional to the relative speed between the magnetic head and the magnetic disk. Therefore, when the diameter of the magnetic disk is further reduced, it is no longer possible to obtain a sufficient reproduction output. Therefore, a magnetoresistive effect type magnetic head (hereinafter abbreviated as an MR head) that senses the magnetic flux from the magnetic disk by utilizing the magnetoresistive effect is currently proposed.

FIG. 13 shows a conventional MR head.
It is a front view. 1 in the figure is Al₂ O₃Ceramic such as TiC
Substrate made of black material, 2 is Al₂ O₃ , SiO₂ etc
Insulating layer 3 made of soft magnetic material such as NiFe
Part shield layer, 4 is Al₂ O ₃ , SiO₂ Consists of etc.
Insulating layer that becomes the reproduction gap of the part, 5 is an amorphous alloy,
Magnetoresistive film 7 made of NiFe or the like (hereinafter referred to as MR film)
A soft magnetic film for applying a lateral bias magnetic field to the
a, Ti, SiO₂ Soft magnetic film 5 and MR film 7
Is an intermediate layer for magnetically separating the
Is an antiferromagnetic film for controlling the magnetic domains of the MR film 7, and 9 is
For example, a lead layer of Au, W, etc., 10 is Al₂ O₃ , Si
O₂ Insulating layer 11 made of
An upper shield layer made of NiFe or the like, 12 is Al₂ O
₃ , SiO₂ And MR head which is a reproducing head.
An insulating layer for separating the recording head, 13 is made of NiFe or the like
Is a soft magnetic layer that serves as the lower core of the recording head, and 14 is Al
₂ O₃ , SiO₂ Insulation that is a recording gap
The layer, 15 is made of NiFe or the like and serves as an upper core of the recording head.
Soft magnetic layer, 16 is Al₂ O₃ Protection of the whole
It is an insulating layer serving as a layer.

In this head, since the recording track width and the reproducing track width can be set individually, wide write-narrow read (wide recording and narrow reproducing) is possible. Further, as a lateral bias method for maintaining the linearity of the output, SAL (Soft-Adjacent) is used.
-Layer) bias method is used. The soft magnetic film 5 is magnetized by the magnetic field generated by the sense current flowing through the MR film 7, and the bias magnetic field is applied to the MR film 7 by the magnetic field generated by the magnetization of the soft magnetic film 5. Is applied. The antiferromagnetic film 8 is for controlling the magnetic domains of the MR film 7 in order to suppress Barkhausen noise peculiar to the MR head, and the exchange coupling magnetic field working with the MR film 7 causes the magnetic field in the track width direction ( (Indicated by an arrow in the figure), a suppressing magnetic field is applied to make the MR film 7 into a single magnetic domain.

The operation of the MR head having such a configuration will be briefly described. When the magnetic field generated by the magnetization recorded on the magnetic recording medium by the recording head flows into the track portion of the MR film 7, the electric resistance changes depending on the magnitude of the magnetic flux.
At this time, since the sense current is flowing through the MR film 7, the change in electric resistance can be detected as a voltage change.

At this time, by changing the thickness of the soft magnetic film 5 and the magnitude of the saturation magnetic flux density, the magnitude of the bias magnetic field is changed to provide the optimum bias.

[0009]

However, in the above-mentioned conventional structure, since the antiferromagnetic film 8 is generally made of a material that easily corrodes, the antiferromagnetic film 8 may be corroded immediately after it is formed. As a result, the characteristics of the MR head may deteriorate, or the antiferromagnetic film 8 may gradually corrode due to long-term use even if the MR head does not corrode immediately after its formation, which also deteriorates the characteristics of the MR head. It was As a cause of the deterioration of the characteristics of the MR head, for example, corrosion of the antiferromagnetic film 8 increases the electric resistance between the antiferromagnetic film 8 and the lead layer 9 to generate thermal noise, and the function of the antiferromagnetic film 8 itself. May decrease.

Further, since the antiferromagnetic film 8 tends to gradually change from the antiferromagnetic material to the paramagnetic material with increasing temperature, the magnetic domain of the MR film 7 is controlled as shown in FIG. The magnetic field (exchange-coupling magnetic field) for reducing gradually decreases. Therefore, when the temperature of the MR head rises due to heat generation of the lead layer or the like, if a magnetic field is applied from the outside in a direction different from the direction of the magnetic field for controlling the magnetic domain, the magnetic field for controlling the magnetic domain when the temperature decreases. Has changed its direction,
As a result, Barkhausen noise may occur during data reproduction, resulting in a data reading error.

Therefore, as described above, in the conventional structure, the characteristics of the MR head may be deteriorated due to corrosion of the antiferromagnetic film 8 or the temperature rise of the antiferromagnetic film 8, resulting in low reliability. was there.

[0012] The present invention is intended to provide the intended to solve the conventional problems, the method for manufacturing a magneto-resistance effect type magnetic heads which can improve reliability.

[0013]

In order to achieve the above object, a magnetoresistive film is formed on a substrate, and an antiferromagnetic film composed of FeMn-based alloy is laminated on the magnetoresistive film,
A method of manufacturing a magnetoresistive effect magnetic head, comprising forming a protective film on an antiferromagnetic film, comprising: forming an antiferromagnetic film and a protective film in a vacuum; the subsequent protective film is formed without break, on the protective film
To form a lead layer on the protective film,
Oxide type rather than Fe and Mn as the material for the protective film
At least one element among the elements with small energy
Alternatively, an amorphous alloy was used. Also, as a protective film
CoNiPt, CoPt, CoCrPt, CoCrT
a, CoCrTaPt, CoNiCr, CoNiCrP
It has a configuration using one of t and CoNi.

[0014]

With the above structure, the present invention can achieve low electric resistance, improve reliability of the MR head, and reduce thermal noise. Further, the reliability of data reading during operation of the MR head can be improved and a high performance MR head can be obtained.

[0015]

【Example】

(Embodiment 1) FIG. 1 is a front view showing a magnetoresistive magnetic head according to an embodiment of the present invention. In FIG.
1 is a substrate, 2 is an insulating layer, 3 is a lower shield layer, 4 is an insulating layer, 5 is a soft magnetic film, 6 is an intermediate layer, 7 is an MR film, 8 is an antiferromagnetic film, 9 is a lead layer, 10 is An insulating layer, 11 is an upper shield layer, 12 is an insulating layer, 13 is a soft magnetic layer, 14 is an insulating layer, 15 is a soft magnetic layer, and 16 is an insulating layer, which are the same as in the conventional structure.

Reference numeral 17 is a protective film provided between the antiferromagnetic film 8 and the lead layer 9, and the protective film 17 is made of Cr, Ta, Ti,
It is composed of at least one kind of metal or amorphous alloy of metals having smaller oxide formation energy than Fe and Mn such as Ni and Cu. Although CoNbZrTa was used as the amorphous alloy in this embodiment, the amorphous alloy is excellent in corrosion resistance, so that the same effect can be obtained with other compositions. By providing the protective film 17 on the antiferromagnetic film 8 which is easily corroded, the antiferromagnetic film 8 can be prevented from being corroded, so that the characteristic deterioration of the MR head can be prevented. In this embodiment, the protective film 17
Was provided only on the antiferromagnetic film 8,
If the protective film 17 is provided so as to sandwich it, the corrosion resistance can be further improved.

Next, a method of manufacturing the MR head having the above-mentioned structure will be described below with reference to FIGS.

First, as shown in FIG. 5, Al ₂ O ₃ , TiC
An insulating layer 2 made of Al ₂ O ₃ , SiO ₂ or the like is formed on a substrate 1 made of a ceramic material such as Al by sputtering.
Is deposited to a thickness of about 2 to 3 μm, and the lower shield layer 3 made of a soft magnetic material such as NiFe or FeAlSi is formed thereon by a sputtering method or a plating method so as to have a predetermined shape. At this time, the lower shield layer 3 was formed to have a thickness of about 2 μm. Further, in order to form the lower shield layer 3 into a predetermined shape, a film is formed after forming a pattern on the insulating layer 2 using a resist or the like in advance, or the film is processed into a predetermined shape by milling or the like. To do.

Next, as shown in FIG. 6, on the lower shield layer 3.
Al by sputtering method ₂ O₃ , SiO₂ etc
The insulating layer 4 which is made of
Approximately 2000 Å film is formed and then sputtered on the insulating layer 4.
NiFeRh, a vacuum deposition method, etc.
Soft magnet for applying transverse bias magnetic field such as morphus alloy
The flexible film 5 is formed with a film thickness of about 200 to 300 Å and further softened.
The magnetic film 5 is formed on the magnetic film 5 by sputtering and vacuum deposition.
Ta, Ti, SiO₂ The intermediate layer 6 consisting of
It is formed with a film thickness of about 300Å, and then a spa is formed on the intermediate layer 6.
NiFe or the like by the tertering method or vacuum deposition method
The MR film 7 made of a film having a thickness of 200 to 500 Å
It

After that, as shown in FIG. 7, a pattern is formed by the photoresist 21 to form the antiferromagnetic film 8 and the lead layer 9 into a predetermined shape.

Thereafter, as shown in FIG. 8, an antiferromagnetic film 8 made of a FeMn-based alloy is formed by a sputtering method or the like.
The protective film 17 is formed with a film thickness of about 0 to 300Å and continuously without breaking the vacuum. Here, as a device capable of forming a film without breaking the vacuum, a continuous sputtering device or the like can be considered. The film thickness of the protective film 17 is 50 to 50.
The range of 0Å is desirable, and the range of 100 to 300Å is preferable. In this example, Ta was deposited to a film thickness of 200Å.

Next, as shown in FIG. 9, a lead layer 9 made of Au or the like is formed to a film thickness of 1000 to 2000 Å by using a vacuum evaporation method or the like.

Next, as shown in FIG. 10, the photoresist 21 is removed by performing lift-off or the like to form a lead layer 9 for supplying a current to the MR film 7.

After that, as shown in FIG. 11, an insulating layer 10 made of Al ₂ O ₃ , SiO ₂ or the like, which is to be an upper reproduction gap, is formed in a thickness of 1000 to 2000 by a sputtering method or the like.
It is formed with a film thickness of about Å. An upper shield layer 11 made of NiFe or the like is formed thereon in a predetermined shape and has a film thickness of 1 to 3 μm by a sputtering method or a plating method.

Next, as shown in FIG. 12, an insulating layer 12 made of Al ₂ O ₃ , SiO _2, etc., which separates the MR head, which is a reproducing head, from the recording head, is formed to a thickness of about 1 μm by a sputtering method or the like, and thereafter. Then, the soft magnetic layer 13 which will be the lower core of the recording head is formed. Next, a soft magnetic layer 15 that serves as an upper core of the recording head is formed on the soft magnetic layer 13 with an insulating layer 14 that serves as a recording gap interposed therebetween. Soft magnetic layer 13,
15 is a soft magnetic material such as NiFe which is formed into a film thickness 2 by applying a thin film forming technique such as a sputtering method or a plating method.
It is formed with a thickness of about 4 μm. Further, the insulating layer 14 is made of Al ₂ O.
It is formed with a film thickness of about 0.6 μm by subjecting a non-magnetic material such as ₃ , SiO ₂ or the like to a sputtering method or the like. Finally, the insulating layer 16 serving as a protective film is formed by subjecting Al ₂ O ₃ or the like to a sputtering method or the like.

The electrical resistance of the MR head (thickness and other conditions described above) constructed as described above was compared with that of the conventional example. The head was processed so that the track width was 4 μm and the height of the MR element portion was 2 μm, and the electrical resistance at that time was measured. The results of 20 measurements are shown in (Table 1).

[0027]

[Table 1]

In the conventional example, it is presumed that the degree of oxidation is probably different, but the electric resistance is high and the variation is large. However, in the example, the electric resistance is low and almost equal to the theoretical value, and the variation is small.

When the lead layer 9 is formed of not a single layer film of Au, W or the like but a composite film having an underlayer, for example, the protective film 17 is Ta and the lead layer 9 is Ta / Au.
The effect is further enhanced by using the same material for the protective film 17 and the underlayer of the lead layer 9 so as to form a layer film.

(Embodiment 2) FIG. 2 is a front view showing an MR head according to a second embodiment of the present invention. The same reference numerals as those shown in FIG. 1 indicate the same functions, and the description thereof will be omitted. In this embodiment, the width regulated by the antiferromagnetic film 8 is different from the width regulated by the lead layer 18 (the manufacturing method and the constituent materials are almost the same as those of the lead layer 9) (that is, the track width). In the case of the present embodiment, it is necessary to form a pattern for forming the lead layer 18 again with a photoresist or the like after forming the FeMn-based alloy. Therefore, F
Since the eMn-based alloy goes through the step of forming this pattern and is naturally immersed in a developing solution, pure water, or the like, the effect of providing the protective film 17 is greater than that of the first embodiment. Particularly, in this case, there is an effect of preventing the function of the FeMn-based alloy from being deteriorated due to corrosion or the like.

The recording / reproducing characteristics of the MR head of this embodiment and a MR head having the structure of this embodiment and having no protective film 17 were compared as a comparative example. Recording and reproduction were performed at a peripheral speed of 8 m / s and a recording frequency of 6 MHz using a 3.5-inch thin film magnetic disk for each of 10 MR heads. As a measuring method, recording / reproduction of a 6 MHz signal was performed 10 times continuously, the average value (x) and the variation (σ) thereof were calculated, and σ / x was calculated as an index of the stability of recording / reproduction. The average value and variation of σ / x for 10 heads are shown in (Table 2) (film thickness and the like are the same as in Example 1).

[0032]

[Table 2]

In the comparative example, both the average value and the variation are large and the control of the magnetic domain of the MR film 7 varies, but in the present example, both the average value and the variation of σ / x are small. Recognize.

(Embodiment 3) FIG. 3 is a front view showing a magnetoresistive head according to a third embodiment of the present invention. Reference numeral 19 denotes a hard magnetic material provided between the antiferromagnetic film 8 and the lead layer 18, and the other configurations are the same as those in (Example 2). CoNiPt, CoP as the hard magnetic material 19
t, CoCrPt, CoCrTa, CoCrTaPt,
One of CoNiCr, CoNiCrPt, and CoNi can be used. Further, although the magnitude of the magnetic field generated can be controlled by the film thickness of the hard magnetic material 19,
If it is too thick, the reproduction gap becomes thick, which is not preferable. Therefore, the film thickness of the hard magnetic material 19 is 100 to 1
It is preferable to select 000Å, preferably 200 to 500Å. In the present embodiment, even if the antiferromagnetic film 8 changes from antiferromagnetic material to paramagnetic material due to a temperature rise of, for example, 150 ° C. or more, the hard magnetic material 19 provided on the antiferromagnetic film 8 is changed. Thus, since the magnetic field is applied in the track width direction, the direction of the magnetic field for controlling the magnetic domain is not disturbed by the external magnetic field, so that the magnetic domain of the MR film 7 can be stably controlled. Further, as an accompanying effect, it is possible to control the magnetic domains of the MR film 7, the lower shield layer 3 and the upper shield layer 11 by the magnetic field generated from the hard magnetic material 19.

The recording / reproducing characteristics of the MR head of this embodiment and a MR head having no hard magnetic material 19 having the structure of this embodiment were compared as a comparative example. In this case, 400 Å of CoNiPt is deposited as the hard magnetic material 19.

For recording and reproduction, a thin film magnetic disk of 3.5 inches was used for each of 10 MR heads, and the peripheral speed was 8 m /
s, recording frequency was 6 MHz. Measuring method is 6MHz
The signal was recorded and reproduced 10 times consecutively, the average value (x) and the variation (σ) were calculated, and σ / x was calculated as an index of the stability of recording and reproduction. Σ for 10 heads
The average value and variation of / x are shown in (Table 3). Further, an external magnetic field was applied to the head in an atmosphere at 160 ° C. in a direction perpendicular to the magnetic field for controlling the magnetic domains of the MR film 7, and the subsequent recording / reproduction was similarly measured. The results are also shown in (Table 3).

[0037]

[Table 3]

In this embodiment, σ / x is obtained even in normal measurement.
The reason why both the average value and the variation of are small are that the hard magnetic material 19 also has the effect of preventing the corrosion of the antiferromagnetic film 8. Further, in the result of the experiment conducted through the high temperature atmosphere, it can be seen that the average value and the variation in the comparative example are larger than those in the normal experiment, whereas the results in the present example are almost the same as those in the normal experiment.

(Embodiment 4) FIG. 4 is a front view showing a magnetoresistive effect magnetic head according to a fourth embodiment of the present invention. The feature of this embodiment is that the hard magnetic material 19 shown in (Embodiment 3) has a two-layer structure including a single layer structure and an underlayer 20. In this case, the hard magnetic material 19 is made of CoNiPt, CoPt, CoCrPt, CoC as described above.
rTa, CoCrTaPt, CoNiCr, CoNiC
One of rPt and CoNi was used as Cr for the underlayer 20.
Is used. Since the hard magnetic material 19 described above has a large coercive force on Cr, the direction of the magnetic field is unlikely to be changed with respect to the external magnetic field, and the effect is further enhanced.

It was confirmed that the MR head of the present embodiment can also obtain the same effect as that of (Embodiment 3).

Although the MR head and the write head are separated from each other in the above embodiment, it is clear that the structure in which the upper shield and the lower core are integrated is also effective and the lateral bias is applied. Regarding the means here, S
Although the AL bias has been shown, it is clear that the effects of this embodiment can be obtained also with respect to the shunt bias, the current bias, the permanent magnet bias, and the like. Further, in order to improve the corrosion resistance of the antiferromagnetic film 8 itself, Cr, Pt, Rh, N
Similar effects can be obtained even when b or the like is added.

[0042]

According to the present invention, a magnetoresistive effect film is formed on a substrate, and an antiferromagnetic film made of FeMn-based alloy is laminated on the magnetoresistive effect film. A method of manufacturing a magnetoresistive effect magnetic head, wherein a protective film is formed on an antiferromagnetic film and a protective film in a vacuum, and after the antiferromagnetic film is formed, the vacuum is continuously maintained without breaking the vacuum. To form a protective film, form a lead layer on the protective film, and form the protective film.
Oxide formation energy than Fe and Mn
At least one element or element
Morphos alloy was used. Further, as a protective film, CoNi
Pt, CoPt, CoCrPt, CoCrTa, CoC
rTaPt, CoNiCr, CoNiCrPt, CoN
It has a configuration in which one of i is used.

With the above structure, corrosion of the antiferromagnetic film can be prevented, and characteristic deterioration of the MR head caused by temperature rise of the antiferromagnetic film can be prevented, so that reliability is improved.

[Brief description of drawings]

FIG. 1 is a front view showing a magnetoresistive head according to an embodiment of the present invention.

FIG. 2 is a front view showing a magnetoresistive effect magnetic head according to a second embodiment of the invention.

FIG. 3 is a front view showing a magnetoresistive effect magnetic head according to a third embodiment of the invention.

FIG. 4 is a front view showing a magnetoresistive head according to a fourth embodiment of the present invention.

FIG. 5 is a process diagram showing a method of manufacturing a magnetoresistive effect magnetic head according to an embodiment of the present invention.

FIG. 6 is a process diagram showing a method of manufacturing a magnetoresistive effect magnetic head according to an embodiment of the present invention.

FIG. 7 is a process diagram showing a method of manufacturing a magnetoresistive effect magnetic head according to an embodiment of the present invention.

FIG. 8 is a process diagram showing a method of manufacturing a magnetoresistive effect magnetic head according to an embodiment of the present invention.

FIG. 9 is a process diagram showing a method of manufacturing a magnetoresistive effect magnetic head according to an embodiment of the present invention.

FIG. 10 is a process diagram showing a method of manufacturing a magnetoresistive effect magnetic head according to an embodiment of the present invention.

FIG. 11 is a process diagram showing a method of manufacturing a magnetoresistive effect magnetic head according to an embodiment of the present invention.

FIG. 12 is a process chart showing a method of manufacturing a magnetoresistive effect magnetic head according to an embodiment of the present invention.

FIG. 13 is a front view showing a conventional magnetoresistive head.

FIG. 14 is a graph showing the relationship between temperature and the magnitude of a magnetic field that controls magnetic domains.

[Explanation of symbols]

1 substrate 2,4,10,12,14,16 Insulation layer 3 Lower shield layer 5 Soft magnetic film 6 Middle class 7 Magnetoresistive film 8 Antiferromagnetic film 9 Lead layer 11 Upper shield layer 13,15 Soft magnetic layer 17 Protective film 18 Lead layer 19 Hard magnetic material 20 Underlayer

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G11B 5/39

Claims (4)

(57) [Claims] 1. A magnetoresistive film is formed on a substrate, an antiferromagnetic film made of a FeMn-based alloy is laminated on the magnetoresistive film, and a protective film is formed on the antiferromagnetic film. A method of manufacturing a magnetoresistive effect magnetic head, wherein an antiferromagnetic film and a protective film are formed in a vacuum, and after forming the antiferromagnetic film, a protective film is continuously formed without breaking the vacuum. Then, a lead layer is formed on the protective film, and the protective layer is formed.
Oxide formation than Fe and Mn as materials for protective film
At least one of the elements with low energy
A method of manufacturing a magnetoresistive effect magnetic head, characterized by using an amorphous alloy . Wherein Fe, oxide formation energy smaller elements Cr, Ta, Ti, Ni, magnetoresistive head according to claim 1, characterized in that the Cu than Mn
Manufacturing method . 3. A magnetoresistive film is formed on a substrate, and the magnetic
The antiferromagnetic film is laminated on the air resistance effect film,
Manufacture of a magnetoresistive effect magnetic head with a protective film formed on it
A method for forming an antiferromagnetic film and a protective film in vacuum
In addition, the vacuum is broken after the antiferromagnetic film is formed.
Without fail, form a protective film continuously on the protective film
A lead layer is formed, a hard magnetic material is used as the protective film, and CoNiPt, CoPt, C are used as the hard magnetic film.
oCrPt, CoCrTa, CoCrTaPt, CoN
NiCr, CoNiCrPt, producing side of magnetoresistance effect magnetic head you characterized by using one of the CoNi
Law . 4. A method of manufacturing a magnetoresistive effect type magnetic head according to claim 3, wherein a hard magnetic material is provided on the antiferromagnetic film via an underlayer.