JP2002008206A - Method for manufacturing thin film magnetic head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a thin film magnetic head, by which generation of re-deposition is suppressed, an upper core can be formed in a prescribed pattern and the thin film magnetic head can be manufactured in a high yield. SOLUTION: The method for manufacturing a thin film magnetic head having a coil disposed between a lower core and the upper core, has a stage for forming a base film 42 for plating on an insulating film 41 formed so as to cover the coil, a stage for forming frames 43 having a prescribed pattern thereon, a stage for plating a material 44 of the upper core on the base film 42 for plating, a stage for removing the frames 43, a stage for removing the base film 42 for plating under the frames 43 and a stage for removing the material 44 of the upper core of unnecessary part, and frames 43 having 8-15 μm width D are formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a thin-film magnetic head such as an inductive head.

[0002]

2. Description of the Related Art Generally, a thin film magnetic head is a magnetic head having a structure in which thin film layers such as a magnetic film and an insulating film are laminated in multiple layers, and furthermore, a conductor coil, a lead wire, and a terminal are formed. Since this thin-film magnetic head is formed by a vacuum thin-film forming technique, it is easy to make fine dimensions such as narrow tracks and narrow gaps, and is capable of high-resolution recording. Has attracted attention as a magnetic head corresponding to.

For example, as a thin film magnetic head for recording and reproducing information signals on a magnetic recording medium, a conductor coil and a magnetic film are formed on a substrate made of an oxide magnetic material such as ferrite by a vacuum thin film forming technique. Some have been configured.

[0004] Specifically, for example, a so-called inductive type magnetic head (hereinafter referred to as an inductive type head) is suitable as a thin film magnetic head for recording. In this inductive head, a lower core made of a soft magnetic layer is formed on a substrate made of an oxide magnetic material such as ferrite, and an insulating layer or an insulating layer for insulating the lower core and the conductor coil is formed thereon. A flattening layer is formed, and a conductor coil is formed spirally on the surface. Then, a flattening layer made of a polymer material such as a resist for flattening the surface is formed, and an upper core made of a soft magnetic material layer is formed on the flattened surface of the flattening layer. Is constituted.

The above-mentioned inductive head is, for example, a magnetoresistive thin-film magnetic head (MR head) for reproduction.
In addition, they are used as being mounted on a hard disk drive or the like as a composite thin film magnetic head.

When manufacturing the above-described inductive head, the upper core is formed by a so-called frame plating method. Here, the step of forming the upper core by the frame plating method will be described.

First, as a base film for plating, for example, a NiFe film is formed by a sputtering method. Next, on the surface of the base film, for example, an NiFe film serving as an upper core and a lead wire is formed by frame plating. The procedure of the frame plating method is performed as follows.

(1) A frame (frame) serving as a mold for an upper layer core and a lead wire by patterning a resist or the like.
To form (2) Using a base film as a plating electrode, a plating film such as a NiFe film serving as an upper core and a lead wire is plated. (3) Remove the frame. (4) The plating base film of the frame portion, that is, the plating base film under the frame is removed by ion etching. (5) A resist mask is formed so as to cover the portion where the frame was and the plating film inside the frame. (6) Using the resist mask as a mask, the NiFe film (plated film) outside the frame is removed by wet etching.

[0009]

However, when the underlying film in the frame portion is removed by ion etching, so-called redeposition, that is, redeposition of the underlying film material occurs.

This re-deposition remains without being removed by the wet etching in the step (6) for removing the unnecessary plating film thereafter, and finally, the surface facing the magnetic recording medium, that is, the so-called ABS (Air Bearing) Surface), resulting in poor appearance and reduced yield. In addition, there is a concern that the re-deposit will fall off and damage the magnetic recording medium.

The best way to eliminate re-deposition is not to etch the underlying film in the frame portion. That is, while the base film of the frame portion is left, the unnecessary plating film outside the frame is removed by covering with the resist mask.

However, when this method is adopted, the base film (NiFe, which is the same as the plating film) of the frame portion is formed by wet etching for removing an unnecessary plating film outside the frame.
When the film is etched, a gap is formed and the etchant leaches into the inner core portion, and the NiF
The e film (plating film) is eroded. For this reason, the upper core cannot be formed in a predetermined pattern. Especially this phenomenon is that the coil becomes a multilayer coil,
This becomes more remarkable as the inclination angle of the flattening film increases.

In order to solve the above-mentioned problem, in the present invention, the occurrence of re-deposition is suppressed and the upper core can be formed in a predetermined pattern, so that a thin-film magnetic head can be manufactured with high yield. An object of the present invention is to provide a method for manufacturing a thin film magnetic head.

[0014]

According to the method of manufacturing a thin film magnetic head of the present invention, a thin film magnetic head having a coil disposed between a lower core and an upper core is manufactured by covering the coil. A step of forming a plating base film on the insulating film, a step of forming a frame of a predetermined pattern on the plating base film, a step of plating an upper core material on the plating base film, and removing the frame The process of
A step of removing a plating base film under the frame; and a step of removing an unnecessary portion of a material of an upper layer core.
m.

According to the manufacturing method of the present invention described above, in the step of forming a frame, by setting the width of the frame to 8 to 15 μm, even if the etching amount at the time of removing the plating base film is reduced, it is unnecessary. In the step of removing the material of the upper core of the portion, it is possible to prevent the wet etching solution from eroding into the portion to be the upper core. This makes it possible to reduce the amount of etching of the plating base film and suppress the occurrence of re-deposition.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention relates to a method of manufacturing a thin-film magnetic head in which a coil is disposed between a lower core and an upper core. Forming a base film, forming a frame of a predetermined pattern on the plating base film, plating an upper core material on the plating base film, removing the frame, A method for manufacturing a thin-film magnetic head, comprising: a step of removing a lower plating base film; and a step of removing an unnecessary portion of a material of an upper layer core, wherein a frame width is 8 to 15 μm in a frame forming step. It is.

FIG. 1 is a schematic structural view (cross-sectional view) of a magnetic head to which the present invention is applied. The cross-sectional view in FIG. 1 is a cross-sectional view perpendicular to the so-called ABS plane facing the magnetic recording medium. The thin-film magnetic head 10 is a composite thin-film magnetic head formed by integrally laminating a read-only magnetoresistive head (MR head) 1 and a recording-only inductive head 2.

The MR head 1 includes a magnetoresistive element (GM)
R element or MR element; hereinafter simply referred to as MR element) 14
Are arranged on the ABS side facing the magnetic recording medium, and one end face is exposed to the magnetic recording medium.

Specifically, a lower shield 12 made of a soft magnetic film is formed on a substrate 11 to constitute a lower magnetic pole. The lower gap film 1 is formed on the lower shield 12.
3, an MR element 14 having a magnetoresistive effect is arranged. An insulating film 15 made of, for example, Al ₂ O ₃ filling the step of the MR element 14 is embedded behind the MR element 14. An intermediate shield 17 of a soft magnetic film is provided on the MR element 14 with an upper gap film 16 interposed therebetween. The intermediate shield 17 forms an upper magnetic pole. The gap of the MR head 1 is formed by the lower gap film 13 and the upper gap film 16.

On the other hand, the inductive head 2 is made of a soft magnetic film, and the intermediate shield 1 constituting the MR head 1.
7 as a lower magnetic core, on this intermediate shield 17,
For example, it has a recording gap film 18 made of SiO ₂ or Al ₂ O ₃ . An upper pole 19 made of a magnetic film is formed on a front end side of the recording gap film 18 facing the magnetic recording medium. Behind the upper pole 19, the insulating layer 2
0 is embedded and the surface is flattened. A coil 21 made of a conductor is formed on the flattened surface, and an insulating film 22 is formed to cover the coil 21. The coil 21 has a spiral shape (not shown) in plan view. Then, by using the coil 21, a signal is supplied to the inductive head by electromagnetic conversion.

Further, an upper core (back yoke) 23 made of a magnetic film is formed above the insulating film 22 and connected to the upper pole 19. An upper magnetic core is constituted by the upper pole 19 and the upper core (back yoke) 23. The upper core (back yoke) 23 is connected to the intermediate shield 17 at the rear to form a magnetic path.

Further, the thin-film magnetic head 10 having this configuration is
Since it is formed by vacuum thin film forming technology, it has features that it is easy to make fine dimensions such as narrow tracks and narrow gaps, and high-resolution recording and reproduction is possible. It is attracting attention as a head.

FIG. 2 is a schematic diagram (cross-sectional view) of another magnetic head to which the present invention is applied. This magnetic head 30 is different from the magnetic head 10 shown in FIG.
The case where the coil is formed in two layers is shown.

In the magnetic head 30, the first coil 2
1, an insulating film 22 is formed, the surface of the insulating film (first planarizing film) 22 is planarized, and the second coil 24 is formed on the planarized surface. Second coil 24
Has a spiral planar shape, similar to the first coil 21. Further, an insulating film 25 is formed so as to cover the second coil 24, the surface of the insulating film (second flattening film) 25 is flattened, and an upper core (made of a soft magnetic material) is formed on the flattened surface. A back yoke 23 is formed. Other configurations are the same as those of the magnetic head 10 shown in FIG.

Instead of flattening the surface of the insulating film 22, a flattening insulating film may be formed on the insulating film 22 and then the surface may be flattened.

In the case of the magnetic head 30, since the coil is formed of two layers of the first coil 21 and the second coil 24, the following advantages are obtained as compared with the case where the coil has only one layer. Having. In order to improve the overwrite characteristics of the recording head, that is, to increase the recording performance, it is conceivable to increase the number of turns of the coil. If an attempt is made to increase the number of windings while keeping the coil in a single layer, the coil becomes large and expands in a plane, so that the magnetic path length becomes long.
For this reason, operating at a high frequency increases the loss. On the other hand, when the coil has two or more layers, the number of turns of the coil can be increased while keeping the magnetic path length short, and the overwrite characteristics can be improved.

Next, as one embodiment of the present invention, the magnetic head 10 shown in FIG. 1 and the magnetic head 3 shown in FIG.
0 will be described.

First, prior to manufacturing the inductive head 2, an intermediate shield 17 made of a soft magnetic material is formed above the MR element 14 to manufacture the MR head 1. Next, a recording gap film 18 is formed on the intermediate shield 17.

Next, an upper pole 19 having a predetermined pattern is formed on the recording gap film 18 on the side to be the ABS. Then, an insulating layer 20 is formed so as to cover portions other than the upper pole 19 so as to cover the upper pole 19, and thereafter, the surface is flattened and the upper pole 19 is exposed to the surface.

Next, a coil plating base film, for example, a Cr / Cu film (not shown) is formed on the flattened surface by sputtering. Then, a photoresist is applied on the plating base film for the coil, and a mask is applied to form a resist pattern having a predetermined shape. This resist pattern is for forming the spiral shape of the coil.

Next, a conductive film such as Cu
Plating the membrane. As a result, the spiral coil 21 is formed under the control of the resist pattern. Thereafter, the resist pattern is removed using an organic solvent, and the plating base film for the coil is further removed using an ion milling device.

Next, in order to cover the coil 21 and to planarize the surface, a resist is hard-cured to form an insulating film 22.

In the case of the magnetic head 30 having the two-layer coil shown in FIG. 2, the following steps are further added after the formation of the insulating film 22. First, a plating base film for the second coil 22, for example, a Cr / Cu film is formed on the insulating film (first planarization film) 22 by a sputtering method. And
A second coil 24 is formed in the same manner as the first coil 22.

After that, the resist pattern is removed by using an organic solvent, and the plating base film is further removed by an ion milling device. Next, in order to cover the second coil 24 and planarize the surface, a resist is hard-cured to form an insulating film (second planarizing film) 25.

Subsequently, on the insulating film 22 in the case of the magnetic head 10 of FIG. 1, and on the insulating film (second flattening film) 25 in the case of the magnetic head 30 of FIG. To form

The upper core 23 formed by the frame plating method
Will be described in detail below with reference to FIGS. 3 to 5 show sectional views parallel to the ABS.

First, as shown in FIG.
The upper core 23 is plated by sputtering on the upper surface, that is, on the insulating film 22 in the case of the magnetic head 10 of FIG. 1 and on the insulating film (second planarization film) 25 in the case of the magnetic head 30 of FIG. A base film 42 for use, for example, a NiFe film is formed.

Next, after a photoresist is entirely formed on the plating base film 42, the photoresist is patterned into a predetermined shape by a photolithography technique, and as shown in FIG. Frame 4
Form 3

At this time, in the present embodiment, particularly, the width D of the frame 43 is set to 8 μm or more and 15 μm or less.

Specifically, for example, in the planar frame 43 shown in FIG. 6, the width D of the frame 43, for example, the width D1 of the diagonal portion and the width D2 of the horizontal portion are set to 8 μm or more and 1 μm or more.
5 μm or less. The cross-sectional views shown in FIGS. 3 to 5 correspond to, for example, cross-sectional views taken along line AA in FIG.

Next, plating is performed using the base film 42 as an electrode to form a plating film 44 to be the upper core 23, for example, a NiFe film, as shown in FIG. 3C.

Thereafter, as shown in FIG. 4D, the frame 43 is removed using an organic solvent. Further, as shown in FIG. 4E, etching using an ion milling device is performed to remove the plating base film 42 under the frame portion, that is, the frame 43. Here, the flattening film 4
Etching is stopped at the interface with No. 1, ie, just etching.

Here, if etching is performed on the plating base film 42 in the frame portion in the conventional manner, re-deposition occurs as described above. Conventionally, as shown in FIG. 8A, a portion of the flattening film 41 is removed so that the plating base film 42 does not remain on the flattening film 41 in the etching of the plating base film 42 in the frame portion. This is because the etching was performed so that the over-etching was performed. This over-etching is performed so that the plating film 44A of the core portion serving as the upper layer core 23 and the unnecessary plating film 44X are not continuous with the metal film during the wet etching for removing the unnecessary plating film 44X to be performed later. Accordingly, the etching liquid has a function of preventing the erosion of the plating film 44A in the core portion.

When the over-etching is performed, there is a problem that the amount of re-deposition increases as compared with the case where the just etching shown in FIG. 4E is performed. This is because the amount of the plating underlying film 42 that is removed by over-etching increases, and the amount that the removed underlying film 42 adheres to the surrounding underlying film 42 and the plating film 44 as a re-deposit increases. FIG. 8B shows a state where the re-depot 51 is attached. The composition of the re-deposit 51 changes during the etching, and may remain without being removed even in a subsequent step of removing the unnecessary plating film 44X.

The redeposition 51 adhered to the remaining plating film 44A, that is, the plating film 44 on the right side of FIG.
Inconspicuous because it is the same alloy as On the other hand, the redeposition 51 attached to the unnecessary plating film 44X, that is, the red plating film 44 on the left side of FIG. 8B remains alone even after the unnecessary plating film 44X is removed as shown in FIG. 8C. It is very noticeable and has poor appearance.

Therefore, in the present embodiment, the width D of the frame 43 is set to 8 μm or more and 15 μm or less as described above.
The etching of the plating base film 42 is controlled so that the etching amount is reduced as compared with the conventional case and the etching is performed just. Thereby, generation of the re-deposit 51 can be suppressed.

By the just etching, the base film 42 may remain partially at the interface with the flattening film 41 as shown in FIG. 7, for example. However, even if the base film 42 partially remains, the magnetic material is not continuous, so that it does not affect the magnetic properties of the upper core 23. Since the base film 42 is not continuous, the wet etching solution No problems occur because the permeation is blocked.

After the plating base film 42 in the frame portion is removed, the frame 43 is subsequently removed as shown in FIG. 4F.
A cover resist 45 is formed in order to remove unnecessary plating film 44X outside the substrate by wet etching. The cover resist 45 includes a frame portion, that is, a portion where the frame 43 is located, and a plating film 44 inside the frame 43.
For example, it is formed so as to cover the plating film 44A of the core portion.

Then, as shown in FIG. 5G, the unnecessary plating film 44X and the underlying plating film 42 thereunder are dissolved and removed by an etching solution containing nitric acid as a main component. Thereafter, as shown in FIG. 5H, the cover resist 45 is removed using an organic solvent. As a result, the required plating film 44 such as the core plating film 44A remains, and the upper core 23 is formed above the core plating film 44A.

After the formation of the upper core 23, the upper core 23 is covered with a protective film made of an insulating film. Thus, the inductive head 2 is formed. Thereafter, the magnetic head 10 or 30 shown in FIG. 1 or FIG. 2 is formed by exposing the ABS surface by shaving from the front.

By the way, the left independent redeposit 51 shown in FIG. 8C is temporarily hidden by being covered with the above-mentioned protective film. However, if the surface is subsequently shaved to form the ABS, the surface may be exposed to the surface of the ABS, resulting in poor appearance.

According to the above-described embodiment, in particular, by setting the width D of the frame 43 to 8 μm or more and 15 μm or less, the etchant in the frame 43 during wet etching for removing the unnecessary plating film 44X is removed. Erosion of the plating film, for example, the plating film 44A in the core portion, is suppressed, and the occurrence of re-deposition 51 is also suppressed. When the plating film 44 is formed by plating, a magnetic field is applied to the plating film 44A to magnetize the soft magnetic material of the plating film 44A in a certain direction, but the width D of the frame 43 falls within the above range. With this, the soft magnetic material of the plating film 44A can be magnetized without any problem.

If the width D of the frame 43 is less than 8 μm, the width of the cover resist 45 covering the periphery of the plating film 44 becomes narrow, so that the wet etching liquid easily permeates the plating film 44 in the frame 43. In particular, the base film 42
In the case of just etching, the wet etching solution easily penetrates due to the partially remaining base film 42, and the amount of re-deposition 51 increases if over-etching is performed to prevent this.

On the other hand, when the width D of the frame 43 exceeds 15 μm, when a magnetic field is applied to the plating film 44A of the core portion serving as the upper core 23 to magnetize the soft magnetic material of the plating film 44A, This may cause a problem that the plating film 44A is hardly magnetized due to being hindered.

Further, according to the present embodiment, in the step of removing the plating base film 42 of the frame portion by performing etching, the etching amount is reduced compared to the conventional one to perform the just etching, thereby achieving the conventional over-etching. In this case, the amount of re-deposition 51 can be reduced as compared with the case (1). At this time, as shown in FIG. 7, even if a part of the plating base film 42 remains due to the reduction of the etching amount, the base film 42 is not continuous, so that the penetration of the etchant is blocked by the cover resist 45. Thus, the plating film 44A in the core portion is less likely to be eroded. In particular, by setting the width D of the frame 43 to 8 μm or more as described above, the width of the cover resist 45 covering the plating film 44 can be sufficiently ensured, and the permeation of the etching solution can be blocked by the cover resist 45.

That is, since the plating film 44A of the core portion serving as the upper layer core 23 is not eroded, the magnetic characteristics of the magnetic heads 10 and 30, especially the inductive head 2, are not deteriorated, and the etching amount of the base film 42 is reduced. However, the plating film 44A in the core portion is not eroded.

Therefore, according to the present embodiment, the re-depot 51
Is suppressed, problems such as poor appearance are avoided, the inductive head 2 having desired magnetic characteristics can be manufactured, and the yield in manufacturing can be greatly improved.

Here, the width D of the frame 43 is changed to form the inductive head 2, and the amount of re-deposition 51, the state of erosion of the plating film 44A in the core, the characteristics of the inductive head 2 (over Light ability, etc.). Table 1 shows the results. In Table 1, the amount of etching was 100 in the case of just etching.
%. The head characteristics are indicated by ◎, ○, and Δ in order of good characteristics.

[0059]

[Table 1]

As can be seen from Table 1, if the width D of the frame 43 is within the above-mentioned range of 8 to 15 μm, there is little occurrence of re-deposition 51, no erosion of the plating film 44A in the core portion, and good head characteristics. Is obtained.

When the width D of the frame 43 is as narrow as 4 μm or 6 μm, the amount of etching is large and over-etching is performed, and the amount of re-deposition 51 increases accordingly. Further, since the width D of the frame 43 is small, the plating film 44 in the core portion is not provided.
There was erosion of A. This is probably because the width D of the frame 43 is small, so that the etching may not be performed properly even when over-etching is performed.

The width D of the frame 43 is 16 μm or 18 μm
In this case, the amount of re-deposition 51 is small, but the head characteristics deteriorate. It is considered that this is because, as the width D of the frame 43 increases, the orientation of the plating film 44A in the core portion becomes difficult.

In the above-described embodiment, the present invention is applied to the composite type head composed of the MR head 1 and the inductive type head 2. Accordingly, the present invention can be similarly applied to the case of forming a film of a magnetic material or the like. By applying the present invention, the production yield of the thin-film magnetic head can be improved.

The present invention is not limited to the above-described embodiment, and may take various other configurations without departing from the gist of the present invention.

[0065]

According to the present invention described above, even if the etching amount in removing the plating base film is reduced, the unnecessary portion of the upper core material is removed in the step of removing the material of the upper core. Erosion of the wet etching solution can be prevented. This makes it possible to reduce the amount of etching of the plating base film and suppress the occurrence of re-deposition.

Therefore, according to the present invention, the production yield of the thin film magnetic head can be greatly improved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram (cross-sectional view) of a magnetic head to which the present invention is applied.

FIG. 2 is a schematic configuration diagram (cross-sectional view) of another magnetic head to which the present invention is applied.

3A to 3C are process diagrams showing a manufacturing process of the magnetic head of FIG. 1 or the magnetic head of FIG. 2 according to one embodiment of the present invention;

4A to 4F are process diagrams showing a manufacturing process of the magnetic head of FIG. 1 or the magnetic head of FIG. 2 according to one embodiment of the present invention;

FIGS. 5G and 5H are process diagrams showing manufacturing steps of the magnetic head of FIG. 1 or the magnetic head of FIG. 2 according to the embodiment of the present invention;

FIG. 6 is a plan view of a resist according to an embodiment of the present invention.

FIG. 7 is a diagram showing a case where a plating base film partially remains.

8A to 8C are diagrams for explaining that re-deposition occurs due to over-etching.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 magnetoresistive head (MR head), 2 inductive head, 10, 30 magnetic head, 11 nonmagnetic substrate, 12 lower shield, 13 lower gap film, 14 MR element, 16 upper gap film, 17 intermediate shield, 18 Recording gap film, 19 upper pole,
21 coil (first coil), 22 insulating film (first planarizing film), 23 upper core (back yoke), 24 second coil, 25 insulating film (second planarizing film), 41 planarizing film, 42 plating base film, 43 frame, 44
Plating film, 45 cover resist, 51 redeposition, D
Frame width

Claims (1)

[Claims] 1. A method of manufacturing a thin-film magnetic head having a coil disposed between a lower core and an upper core, wherein a plating base film is formed on an insulating film formed to cover the coil. A step of forming a frame of a predetermined pattern on the plating base film; a step of plating the material of the upper core on the plating base film; a step of removing the frame; A step of removing the lower base film for plating; and a step of removing an unnecessary portion of the material of the upper core. In the step of forming the frame, the width of the frame is set to 8 to 15 μm. A method for manufacturing a thin-film magnetic head, comprising: