JPH0264910A - Thin film magnetic head and manufacture thereof - Google Patents

Abstract

PURPOSE:To cause coil thickness to be thick and to suppress the increase of a coil resistance value due to the increase of the number of windings by obtaining a plating base layer, a Cu plating layer and a specified metal layer for a coil and defining the layers as a laminated body to be filmed in such an order. CONSTITUTION:A coil 5 is formed by the laminated body, for which the plating foundation layer, a Cu plating layer 3 and a Cr or Ti layer or a metal layer 5 to be composed of alloy to define the Cr or Ti as a main component are filmed in this order. Accordingly, at the time of ion-etching in a plating base removing process during a coil forming process, even when the ion-etching is executed to the upper surface of the coil for a long time, since the metal layer 5, whose ion-etching speed is low, such as the Cr or Ti protects the Cu plating layer, the coil thickness is not decreased. Thus, the coil thickness is made thick and the increase of the coil resistance value due to increase of the number of winding can be suppressed.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to dielectric thin film magnetic heads used in magnetic disk devices, magnetic tape devices, etc., and particularly relates to coils and thin film magnetic heads manufactured using integrated thin film technology. The present invention relates to a manufacturing method thereof.

[Conventional technology]

In recent years, in the field of magnetic recording, recording densities have been increasing rapidly, and in magnetic heads that support magnetic recording as well as recording media, thin-film magnetic heads manufactured using integrated thin-film technology have replaced conventional ferrite heads. has been put into practical use. This thin film magnetic head has excellent frequency characteristics,
Since a manufacturing process based on semiconductor technology is applied, it is possible to manufacture high-precision, high-density magnetic heads at low cost, and this is becoming the mainstream of future magnetic heads.

FIG. 6 is a schematic cross-sectional view showing the manufacture of such a thin film magnetic head. In FIG. 6, an insulating layer 12 made of Al2O3 or the like is formed on a ceramic substrate 10 made of Al2O3-TiC or the like by sputtering or the like. Then, Nl
ce alloys and Co-metallic amorphous materials (e.g. CoZrN
A lower magnetic layer 13 made of a soft magnetic material such as b) is formed using integrated thin film technology.

Thereafter, an insulating layer 14 having a thickness equal to a predetermined gap length is formed. Next, an organic material IJ 15 that becomes a step eliminating layer of the lower magnetic layer 13 is formed, and a coil 16 made of a conductive material is formed. After that, coil 16
The organic layer 17, which becomes the step-reducing layer, is formed again using a zero-order NiFe alloy or a Co-metallic amorphous material (for example, Co
Upper magnetic body J'l18 made of soft magnetic material such as ZrNb)
is formed in the same manner as the lower magnetic layer 13, and a protective layer (not shown) made of an insulator is formed to complete the transducer of the thin film magnetic head.

The coil 16 of the thin film magnetic head described above is usually made of a Cu film formed by electroplating, and its cross-sectional structure is as shown in FIG. In other words, the coil 16 is er
It has a laminated structure of a plating base layer consisting of a laminated body of layer 1 and Cu layer 2 and Cu plating layer 3. The manufacturing process of such a conventional coil is shown in FIG. 5. In FIG.
A laminate of layer 2 is formed to form a plating base layer. Then, as shown in FIG. 5(b), a photoresist pattern (hereinafter abbreviated as PR pattern) 4 having a predetermined shape is formed using a known exposure and development technique. After that, see Figure 5 (
As shown in c), Cu is precipitated in a plating medium containing copper sulfate as a main component to form a Cu plating layer 3. Next, the PR pattern 4 is peeled off (FIG. 5(d)),
As shown in Figure (e), a portion of the plating base layer covered with the PR pattern 4 is removed by ion etching in a ^r gas atmosphere to form a coil.

As is clear from FIG. 5(e), the Cu plating layer 3 is also ion-etched in this plating base layer removal process, so the thickness of the Cu plating layer 3 is reduced by the time taken to remove the plating base layer. .

Incidentally, reflecting the trend toward higher recording densities in recent years, the leakage magnetic field from information recorded on a medium is becoming smaller and smaller, and there is a concern that the reproduction output of the head will decrease. Since the reproduction output of an inductive thin-film magnetic head is approximately proportional to the number of turns of the coil, one effective way to compensate for this decrease in reproduction output is to narrow the coil spacing as much as possible to form a dense coil and increase the number of coil turns. It is considered a useful method.

[Problem to be solved by the invention]

However, with the conventional structure and manufacturing method described above, there are problems as described below when increasing the number of coil turns. That is, in dense coils, the coil spacing is naturally narrower than the conventional coil spacing (about 4 μm), and is usually about 2 μm or less. on the other hand,
The coil thickness (the sum of the thickness of the plating base layer and the Cu plating layer 3) is currently around 3 μm, but in order to reduce the effect of an increase in coil resistance due to an increase in the number of coil turns, it can be made thicker (for example, 4 μm or more). In such a dense coil with narrow coil spacing and thick coil thickness, in the process shown in FIG. Compared to forming conventional coils with wide spacing, the time required for the plating underlayer removal process increases significantly. This is because the coil spacing is narrow and the coil thickness is large, so the plating base layer to be removed is located deep from the top surface of the coil (point indicated by arrow A in Figure 2). The plating base that has been knocked out by the Ar particles may re-adhere to the sides of the coils and cannot be easily removed from the space between the coils. This phenomenon is thought to be caused by the fact that the effective etching rate decreases in the areas where the plated parts are etched, and this phenomenon occurs inevitably. As a result, the upper surface of the coil is ion-etched for a long time, and the coil thickness is significantly reduced.Therefore, the effect of increasing the coil thickness and suppressing the increase in coil resistance due to an increase in the number of turns cannot be sufficiently achieved, which is a problem. This becomes more noticeable as the coil thickness becomes thicker and as the coil spacing becomes narrower, and this becomes a major problem in the head manufacturing process.

It is an object of the present invention to solve the above-described problems in the coil forming process of a thin film magnetic head.

[Means to solve the problem]

According to the present invention, a magnetic circuit made of a soft magnetic material, a magnetic gap made of a non-magnetic material formed in the magnetic circuit, and a conductive thin film formed to intersect the magnetic circuit. In the inductive thin film magnetic head, the coil is made of a laminate in which a plating base layer, a Cu plating layer, and a metal layer made of Cr, Ti, or an alloy containing these as main components are deposited in this order. A thin film magnetic head having the following characteristics can be obtained. Here, the metal layer is formed using a plating method, a vapor deposition method, or a sputtering method.

[Effect]

By adopting the above-described structure, the present invention has made it possible to provide a thin film magnetic head that solves the conventional problems. That is,
By forming a metal layer with a low ion etching rate fj on the Cu plating layer, the Cu plating layer is protected during ion etching in the plating base layer removal step, and the Cu plating layer is
Prevents the plating layer from being etched. Therefore,
In principle, it is impossible for the thickness of the Cu plating layer to decrease.

For example, if the plating base layer removal process requires 25 minutes, the ion etching rate of C' is 80 people/min (after gas pressure I x 10-'Torr, acceleration voltage 500V).
, at least about 2000 thick Cr
By forming a structure in which the layers are laminated on the Cu plating layer, it is possible to almost completely prevent the Cu plating layer from being ion-etched. On the other hand, in the conventional coil, the ion etching speed of Cu is approximately 2000 times (ion etching conditions are the same as for Cr), and the Cu plating layer is directly etched by A.
Due to exposure to r-particles, approximately 1.25 μm of the cU plating layer is ion etched and the coil resistance increases by this amount.

If the plating base layer removal process requires a longer time, the thickness of the metal layer may be increased for convenience [Example] Next, the present invention will be described in detail with reference to the drawings. As already mentioned, the present invention is characterized by the coil structure of the dielectric thin film magnetic head, and the general structure of the thin film magnetic head according to the present invention is largely different from the structure of the conventional thin film magnetic head shown in FIG. Therefore, in the following embodiments, parts other than the coil portion will be explained using FIG. 6.

Example 1 In Figure 6, ^! 203-Tic ceramic substrate 1
The insulating layer 12 made of A1
A film with a thickness of 10 μm was formed at a pressure of 0-9 Torr). Next, a COa72r5Nbg film having a thickness of 3 μm was formed using a sputtering technique to form the lower magnetic layer 13. Furthermore, CoB7
The film-forming conditions for the Zr5Nbg film are injection type crab 600 WAr.
The gas pressure was 5 x 10''3 Torr, and after film formation, the film was annealed at 250° C. for 1 hour in a rotating magnetic field of 4800 e to improve its magnetic properties.

Then a film thickness equal to the predetermined gap length (0.2 μm)
An Al2O3 film with
rr) The L insulating layer 14 was used. Next, a photoresist made of novolak resin is applied to a thickness of 4 μm on the lower magnetic layer 13 and cured by heat treatment at 250° C. for 1 hour to form an organic layer 15 that becomes a step-reducing layer of the lower magnetic layer 13. was formed, and then the coil 16 was formed.

The manufacturing method and structure of the coil 16 will be explained below in Figures 3 and 1.
This will be explained in detail using figures. In FIG. 3, the base body 11
(corresponding to the organic material layer 15 in this embodiment) using a sputtering method, 01 layer 1 (film thickness: 30 layers) and Cu layer 2 (
A plating base layer consisting of a laminated film with a film thickness of 2,000 mm) was formed (Fig. 3 (a)), and then a PR pattern 4 that would become a plating frame was formed using a known photolithography technique (Fig. 3 (a)). b)) The photoresist used is a commercially available novolak resin resist. Also, PR
The film thickness of pattern 4 is 6 μm, the pattern width is 1.5 μm,
The pattern interval was 3 μm.

Note that since the pattern width of the PR pattern 4 is 1.5 μm, the coil interval is 1.5 μm. Thereafter, Cu was electroplated in copper sulfate to form a Cu plating layer 3 (FIG. 3(C)). Here, the plating current density is 9.5A/c
m2, and the thickness of the Cu plating layer 3 was 5 μm. Then, using a C plating bath (Sargent bath) using a mixed solution of chromic anhydride and sulfuric acid, a C plating bath with a film thickness of 2500 mm was applied.
A metal layer 5 was formed on the Cu plating layer 3 (Fig. 3(d)).
m2. Next, the PR pattern 4 was peeled off in an organic solvent (Fig. 3 (e)), and finally, unnecessary plating base layer was removed by ion etching in an Ar atmosphere (Fig. 3 (f)).
), the coil 16 was formed. The conditions for ion etching are Ar gas pressure I x 10-'Torr and acceleration voltage 500V. Also, the time required for this plating base layer removal process was about 25 minutes, and during this time, the metal layer 5 made of C was etched at an ion etching rate of 80 people/minute, so 2000 people out of a film thickness of 2500 people etched it. However, the Cu plating layer 3 was not ion-etched at all.

The schematic structure of the coil formed in this way is as shown in Figure 1, consisting of a plating base layer (laminated film of 01 layer 1 and Cu layer 2).
, a metal M5 consisting of a Cu plating layer 3 and a Cr plating film
It has a structure in which these are laminated in this order.

After forming the coil 16 as described above, a photoresist layer 17 which becomes a layer for eliminating the step difference of the coil 16 is formed in the same manner as the photoresist layer 15 described above.
Upper magnetic layer 1 made of μm CoB71rgNbB film
8 was made in the same manner as the lower magnetic layer 13. Finally, Al2O
A protective film (not shown, 25 μm thick) consisting of three films was formed by sputtering. The film forming conditions are injection type crab 8
00W, Ar gas pressure 5 x 10-3 Torr.

In the thin film magnetic head of this example manufactured as described above, during the removal process by ion etching of the plating underlayer as described above, the coil spacing was 1.5 μm because the C plating film protects the Cu plating layer. Despite the coil thickness being as narrow as 5 μm, the Cu plating layer was not etched at all.Therefore, the conventional problem of decreasing coil thickness and increasing coil resistance did not occur. Ta.

Example 2 In the same manner as in Example 1, an insulating layer 12 made of an Al2O film having a thickness of 10 μm was formed on an Al203-Tic ceramic substrate 10. Next, CoB71r with a film thickness of 3 μm
, a NbB film was formed using a sputtering method, and a lower magnetic body M13 was formed using a known photolithography technique. Note that the deposition conditions and annealing for the Cog7Zr5Nb3 film were the same as in Example 1.

Then a film thickness equal to the predetermined gap length (0.2 μm)
An Al2O3 film having the following properties was formed by sputtering to form the insulating layer 14. The film forming conditions were the same as in Example 1. next,
An organic material N15 made of photoresist (film thickness: 4 μm) was formed in the same manner as in Example 1, and then a coil 16 was formed.

The manufacturing and structure of the coil 16 will be explained below in Figures 4 and 1.
This will be explained in detail using figures. In FIG. 4, the base body 11
(corresponding to the organic layer 15 in this example), a CrJll (film thickness of 30 layers) and a Cu layer 2 are formed using a sputtering method.
A plating base layer consisting of a laminated film (film thickness: 2,000 layers) was formed (FIG. 4(a)). Next, a PR pattern 4, which will become a plating frame, was formed using a known photolithography technique (FIG. 4(b)). The photoresist used was a commercially available novolak resin resist. Also, P
The film thickness of R pattern 4 is 6 μm, and the pattern width is 1.5 μm.
The pattern spacing was 3 μm.

Note that since the pattern width of the PR pattern 4 is 1.5 μm, the coil interval is 1.5 μm. Thereafter, Cu is electroplated in copper sulfate to form a Cu plating layer 3 (Fig. 4(c)), where the plating current density is 0.5A/C.
12, and the thickness of the Cu plating layer 3 was 5 μm. Next, a metal layer 5 made of Cr and having a thickness of 2500 nm was formed on the Cu plating layer 3 by a vapor deposition method using an electron beam (FIG. 4(d)). The emission current of the electron gun at this time was 60 mA. Next, the PR pattern 4 is peeled off in an organic solvent, and at the same time, unnecessary C deposited on the PR pattern 4 is removed.
Figure 4(e)). Finally, remove the unnecessary plating base layer by ion etching in the atmosphere.
Figure (f)), the coil 16 is not formed.

The conditions for ion etching are Ar gas pressure of 1 x 10-
'Torr, acceleration voltage 500V. Also, the time required for this plating base layer removal process was approximately 25 minutes,
During this time, since the ion etching rate of the metal layer 5 made of Cr is 80 etching/min, 2000 out of the 2500 etching film thickness is etched.
Although it was manually etched, the Cu plating M3 was not ion etched at all. The schematic structure of the coil formed in this way is shown in Fig. 1, which consists of a plating base layer (laminated film of Cr film 1 and Cu layer 2), a Cu plating layer 3, and a metal M5 consisting of a Cr vapor deposited film. It has a sequentially laminated structure.

After forming the coil 16 as described above, the photoresist layer 17 and CoB7Z, which will become the layer for eliminating the step difference in the coil 16, are formed.
An upper magnetic layer 18 made of an r5NbB film was formed in the same manner as in Example 1. Finally, a protective film (not shown, 25 μm thick) consisting of an Al2O3 film was formed by sputtering. The film forming conditions in this case are also the same as in Example 1.

In the thin-film magnetic head of this example manufactured as described above, the coil spacing is 1.5 mm because the Cr vapor-deposited film protects the Cu plating layer during the removal process by ion etching of the plating underlayer as in Example 1. Although the coil thickness was as narrow as 5 μm and the coil thickness was as thick as approximately 5 μm, the Co plating layer was not etched at all. Therefore, the conventional problems of decreasing the coil thickness and increasing the coil resistance value do not occur. In addition, in order to easily remove the Cr film on the PR pattern 4 during the step of peeling off the PR pattern 4 (step of FIG. 4(e)), the PR pattern forming step (step of FIG. 4(b)) ), it is desirable that the cross-sectional shape of the PR pattern 4 is a stencil shape.

Example 3 In the same manner as Example 1 or Example 2, ^1203-T
On the iC ceramic substrate 10, an insulating layer 12, a lower magnetic layer 13, an insulating layer 14 serving as a gap, and an organic substance JfW1
5 was formed, and then a coil 16 was formed. coil 16
The metal layer 5 was formed by the same process as in Example 2, but in this example, the material of the metal layer 5 was Ti. In this example as well, the plating base layer removal process took about 25 minutes, but the ion etching rate of the Ti film was 50 people/
Therefore, the metal layer 5 has an initial thickness of 1 out of 2500.
Although 250 people were etched, the Cu plating layer 3 was not ion-etched at all. The schematic structure of the coil formed in this way is as shown in Figure 1.
01 layer 1 and CuN2 layer), a Cu plating layer 3, and a metal layer 5 consisting of a Ti vapor deposited film are laminated in this order.

After forming the coil 16 as described above, the photoresist layer 17 and CoB7Z, which will become the layer for eliminating the step difference in the coil 16, are formed.
The upper magnetic layer 18 made of an r5Nbg film was formed in the same manner as in Example 1 or Example 2. Finally, Al2
A protective film (not shown, 25 μm in film thickness) consisting of an O3 film was formed by sputtering.

The film forming conditions in this case are also the same as in Example 1 or Example 2.

In the thin-film magnetic head of this example manufactured as described above, the Ti vapor-deposited film protects the Cu plating layer during the removal process by ion etching of the plating underlayer as in Example 1 or 2. Coil spacing 1.5μm
Although the coil was narrow and the coil thickness was as thick as approximately 5 μm, the Cu plating layer was not etched at all. Therefore, the conventional problems of decreasing the coil thickness and increasing the coil resistance value do not occur. In this example, as in Example 2, it is desirable that the cross-sectional shape of the PR pattern 4 is a stencil shape so that the Ti film on the PR pattern 4 can be easily removed.

Comparative Example Al2O3-Ti was prepared in the same manner as in Example 1, 2 or 3.
An insulating layer 12, a lower magnetic layer 13, an insulating layer 14 serving as a gap, and an organic substance i15 were formed on the C ceramic substrate 10, and then a coil 16 was formed. The coil 16 was formed using the conventional coil forming method shown in FIG.

That is, in FIG. 5, a 01 layer 1 (thickness: 30 mm) and a Cu layer 2 (thickness: 2,000 mm) are formed on a base body 11 (corresponding to the organic layer 15 in FIG. 6 in this example) using a sputtering method.
A plating base layer was formed from a laminated film (FIG. 5(a)). Next, a PR pattern 4, which will become a plating frame, was formed using a known photolithography technique (FIG. 5(b)). The photoresist used was a commercially available novolak resin resist. Further, the PR pattern 4 had a film thickness of 6 μm, a pattern width of 1.5 μm, and a pattern interval of 3 μm, as in Examples 1, 2, or 3. still,
Since the pattern width of PR pattern 4 is 1.5 μm,
The coil spacing is 1.5 μm. Thereafter, Cu is electroplated in copper sulfate to form a Cu plating layer 3 (FIG. 5(C)). Here, the plating current density is 0.5A/cm2
The thickness of the Cu plating layer 3 was 5 μm. next,
PR pattern 4 was peeled off in an organic solvent (Fig. 3(d)
). Finally, the unnecessary plating base layer was removed by ion etching in an Ar atmosphere (FIG. 3(e)), and the coil 16 was formed.

The conditions for ion etching are Ar gas pressure of 1 x 10-
'Torr, acceleration voltage 500V. The time required for this plating base layer removal process was about 25 minutes, but since the Cu ion etching rate is 600 people/min under the above ion etching conditions, the Cu plating layer was removed during this time.
was etched by 1.5 μm.

After forming the coil 16 in the above manner, a photoresist layer 17 and a CoB layer 72 which will become a step elimination layer of the coil 16 are formed.
The upper magnetic layer 18 made of r5Nb6 film was prepared in Example 1,
It was formed in the same manner as 2 or 3.

Finally, a protective film (not shown, 25 μm thick) made of Al2O was formed by sputtering.

The film forming conditions in this case are also the same as in Examples 1, 2, or 3.

In the thin film magnetic head of this comparative example manufactured as described above, as described above, the 1.5 μm thick Cu was etched in the step of removing the plating base layer by ion etching, and the thickness of the Cu plating layer 3 was increased. Diminished. For this reason, although it should originally have had almost the same coil resistance value as the coil of the thin film magnetic head mentioned in Examples 1, 2, or 3, it showed a coil resistance value that was about 30% larger.

〔Effect of the invention〕

As described above, according to the present invention, even in a thin film magnetic head having a dense coil with a narrow coil spacing and a large coil thickness, the coil can be removed during ion etching in the plating underlayer removal step during the coil forming process. Even if the upper surface is ion-etched for a long time, a metal layer such as Cr or Ti with a low ion-etching rate protects the Cu plating layer, so that the coil thickness cannot be reduced. Therefore, the effect of increasing the coil thickness and suppressing an increase in coil resistance value due to an increase in the number of turns is fully exhibited.

As described above, according to the present invention, it is possible to solve problems in the coil forming process of a thin film magnetic head having a dense coil with a large number of turns, and it is considered to have high industrial value.

Incidentally, in the above explanation, only examples using only simple substances of Cr and Ti have been mentioned, but alloys containing these as main components can also be used since the ion etching rate is low. Any other material may be used as long as it has an ion etching rate lower than that of Cu.

Further, in the embodiment, only an example in which the magnetic circuit is formed entirely from a soft magnetic thin film is mentioned, but the present invention can also be applied to a magnetic head in which a part of the magnetic circuit is formed from a bulk material, such as by using a ferrite substrate. Of course, the intended purpose remains intact.

[Brief explanation of the drawing]

FIG. 1, FIG. 3, and FIG. 4 are diagrams for explaining the present invention, and FIG. 2 and FIG. 5 are diagrams for explaining the prior art. Further, FIG. 6 is a schematic cross-sectional view showing the manufacture of an inductive thin film magnetic head according to the present invention. 1... CrrF4.2... Cu layer, 3... Cu plating layer, 4... PR pattern, 5... Metal layer, 10
...Substrate, 11... Base body, 12.14... Insulating layer, 13... Lower magnetic layer, 15.17... Organic layer, 16... Coil, 18... Upper part magnetic layer. Agent Patent Attorney Shini Uchihara 2 Figure

Claims (3)

[Claims] (1) A magnetic circuit made of a magnetic material, a magnetic gap made of a non-magnetic material formed in the magnetic circuit
, and a dielectric thin film magnetic head comprising a coil made of a conductive thin film formed to cross the magnetic circuit, wherein the coil is formed of a plating base layer, a Cu plating layer, and a C plating base layer, a Cu plating layer, and a Cu plating layer.
1. A thin film magnetic head comprising a laminate in which metal layers made of r, Ti, or an alloy containing these as main components are deposited in this order. (2) In a method for manufacturing an inductive thin film magnetic head that includes the steps of sequentially forming an insulating layer, a lower magnetic layer, an insulating layer, an organic material, a coil, an organic material, and an upper magnetic layer on a substrate, the plating base layer a step of forming a photoresist pattern of a predetermined shape on the plating base layer, a step of depositing a Cu plating layer in a plating bath, a step of forming a Cr plating layer on the Cu plating layer, A method for manufacturing a thin film magnetic head, comprising a coil manufacturing process including, in this order, a process of peeling off the photoresist pattern and a process of ion etching an unnecessary plating underlayer in an Ar atmosphere. (3) In a method for manufacturing a dielectric thin film magnetic head that includes the steps of sequentially laminating an insulating layer, a lower magnetic layer, an insulating layer, an organic material, a coil, an organic material, and an upper magnetic layer on a substrate, a step of forming a base layer; a step of forming a photoresist pattern of a predetermined shape on the plating base layer;
a step of depositing a Cu plating layer in a plating bath;
A step of forming a Cr layer or a Ti layer on the plating layer using a vapor deposition method or a sputtering method, a step of peeling off the photoresist pattern, and a step of ion etching the unnecessary plating base layer in an Ar atmosphere are performed in this order. 1. A method for manufacturing a thin film magnetic head, comprising a coil manufacturing process.