JPH06274822A - Thin-film magnetic head and its production - Google Patents

Abstract

PURPOSE:To provide the process for production of the thin-film magnetic head capable of etching and forming an upper magnetic core with good accuracy. CONSTITUTION:A metallic film 61 having the characteristic that the etching rate is high when the incident angle of an ion beam on the normal direction at the time of ion beam etching is small and that the etching rate is low when the incident angle of the beam is large is formed on the surface of a soft magnetic film 21 which constitutes the upper magnetic core 2. The metallic film 61 and the soft magnetic film 121 are then etched with the ion beam at the small incident angle of the beam with the normal direction with a resist 8 as a mask. The region covering the front gap part of the soft magnetic film 22 formed by the etching is thereafter etched with the ion beam at the large incident angle of the beam with the normal direction, by which the front part of the upper magnetic core 2 is finished to a prescribed thickness.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film magnetic head used in various magnetic recording / reproducing devices such as hard disk devices and video tape recorders, and a method of manufacturing the same.

[0002]

2. Description of the Related Art In recent years, with the progress of downsizing in information processing equipment such as computers, there has been a demand for further miniaturization and large capacity of hard disk devices used in the terminal devices. Therefore, as a magnetic head for signal recording / reproduction, a thin film magnetic head capable of recording at a higher density than a conventional bulk type head composed of a magnetic core and windings has been attracting attention.

FIG. 5 shows a structure of a conventional thin film magnetic head in the process of being manufactured. On the surface of the lower magnetic core (1) formed on the substrate (7), a soft magnetic film (21) is formed via a gap spacer (3) and the coil conductor layer (5) is an insulating layer (5). 4) It is embedded and formed in the inside.

In the process of FIG. 5, a resist (8) is formed on the surface of the soft magnetic film (21), and the soft magnetic film (21) is subjected to ion beam etching using the resist (8) as a mask. . As a result, an upper magnetic core that should form a magnetic circuit is formed together with the lower magnetic core (1).

FIG. 4 shows a step of forming the upper magnetic core by the above ion beam etching on a cross section taken along the line AA of FIG. As shown in FIG. 4 (a), the soft magnetic film is formed on the lower magnetic core (1) via the gap spacer (3).
After forming (21), a resist (8) having a predetermined pattern is formed on the surface of the soft magnetic film (21) as shown in FIG.

Then, the soft magnetic film (21) is subjected to ion beam etching using the resist (8) as a mask to form a soft magnetic film (23) having a predetermined contour as shown in FIG. 4 (c).

Further, so-called narrowing is performed by performing ion beam etching only on the region of the soft magnetic film (23) formed by etching, which covers the front gap portion. As a result, the upper magnetic core (20) as shown in FIG.
The front portion of is finished to a predetermined thickness, and the head magnetic field is made steep.

By the way, particularly in a thin film magnetic head to be installed in a magnetic disk device, it is necessary to increase the shape accuracy of the lower magnetic core and the upper magnetic core as much as possible in order to achieve a highly precise narrow track. Therefore, conventionally, as shown in FIG.
Both side walls (81) (81) of the resist (8) serving as a mask as shown in (b)
Is formed on a highly accurate vertical surface (wall angle 90 °), and ion beam etching is performed.

[0009]

However, in the conventional method of manufacturing a thin film magnetic head, when the resist (8) is formed, due to the step difference of the lower soft magnetic film (21) as shown in FIG. The film thickness Ha on the front gap side is larger than the film thickness Hb above the coil conductor layer, which causes a problem of so-called redeposition. That is, when the soft magnetic film in the area not covered by the resist is etched, a part of it is redeposited on the soft magnetic film in the area covered by the resist, and finally the soft magnetic film is softened as shown in FIG. 4 (c). The surface of the magnetic film (23) rises at both sides (23a) (23a). In order to avoid reattachment, it is effective to form both side walls of the resist on slopes, but this lowers the etching molding accuracy of the upper magnetic core.

An object of the present invention is to provide a structure of a thin film magnetic head capable of accurately etching and molding an upper magnetic core, and a manufacturing method thereof.

[0011]

In the thin film magnetic head according to the present invention, the metal film (6) is laminated on the upper surface of the upper magnetic core (2) except for the region covering the front gap portion. The metal film (6) is formed of a metal having a characteristic that the etching rate is large when the beam incident angle with respect to the normal direction during ion beam etching is small, and the etching rate is small when the beam incident angle is large.

Further, in the method of manufacturing a thin film magnetic head according to the present invention, the surface of the soft magnetic film (21) which becomes the upper magnetic core (2),
A step of forming a metal film (61) having a characteristic that the etching rate is large when the beam incident angle with respect to the normal direction during ion beam etching is small, and the etching rate is small when the beam incident angle is large; and the metal film (61)
A step of forming a resist (8) having a pattern corresponding to the shape of the upper magnetic core (2) on the surface of the metal, and using the resist (8) as a mask, the metal film (61) and the soft magnetic film (21) are formed by a method. Ion beam etching process with a small beam incidence angle to the line direction and soft magnetic film formed by etching (22)
Of the above, a step of performing ion beam etching on a region covering the front gap part at a large beam incident angle with respect to the normal direction to finish the front part of the upper magnetic core (2) to a predetermined thickness. .

[0013]

In the above method of manufacturing a thin film magnetic head, when the metal film (61) and the soft magnetic film (21) are subjected to ion beam etching using the resist (8) as a mask, the beam incident angle is set in the direction normal to the etching surface. On the other hand, if it is set small, the etching rate becomes large, and the reattachment of the soft magnetic film is suppressed as much as possible.

However, even in this step, slight re-adhesion occurs on the soft magnetic film, and the surface of the soft magnetic film (22) slightly bulges on both sides. The film (61) remains and the surface of the soft magnetic film (22) is a metal film.
It will be flattened by (61).

After that, when the region of the soft magnetic film (22) formed by etching is covered with the front gap portion, if the beam incident angle is set to be large, the etching rate becomes small, and the soft magnetic film ( It is almost the same as the etching rate for 22). At this time, since the surface of the soft magnetic film (22) is flattened by the metal film (61), the soft magnetic film (22) and the metal film (61) are etched while the flatness is maintained. Finally, the metal film (61) is removed to obtain the upper magnetic core (2) having a uniform thickness.

In the thin film magnetic head manufactured by the above-mentioned manufacturing method, the metal film (61) in the region of the surface of the upper magnetic core (2) covering the front gap is removed, but the upper part except the above region is removed. Metal film on the surface of the magnetic core (2)
(6) is left, and the thin film magnetic head according to the present invention is obtained.

[0017]

According to the thin-film magnetic head and the method of manufacturing the same according to the present invention, even when both side walls of the resist are formed on vertical surfaces, there is no problem due to redeposition in the past during etching, and accuracy is improved. An upper magnetic core having a high height can be obtained.

[0018]

1 and 2 show the structure of a thin film magnetic head according to the present invention. A lower magnetic core (1) and an upper magnetic core (2) which should form a magnetic circuit are laminated on a substrate (7) via a gap spacer (3), and an insulating layer (4) is provided between both cores. Are embedded and arranged in the coil conductor layer (5). The lower magnetic core (1) and the upper magnetic core (2) are Ni-F
It is formed from a soft magnetic material such as e.

A metal film (6) is laminated on the surface of the upper magnetic core (2) except for the region covering the front gap. The metal film (6) is a metal having a characteristic that the etching rate is large when the beam incident angle with respect to the normal direction during ion beam etching is small, and the etching rate is small when the beam incident angle is large, for example, A.
It is made of u, Cu, Ag, etc., and its film thickness is 1-3 μm.
Is. A protective film (not shown) is formed on the upper magnetic core 2 and the metal film 6.

FIG. 6 shows the relationship between the ion beam incident angle and the etching rate for various magnetic metals. Metals (Au, Cu) having the characteristic that the etching rate greatly decreases as the ion beam incident angle increases. , Metals (Ni-Fe, Fe-A) having characteristics that the change in etching rate is relatively small with respect to the change in ion beam incident angle.
1-Si). At a small beam incident angle of 20 ° or less, the former metals have a sufficiently higher etching rate than the latter metals, but at a large beam incident angle of 40 ° to 60 °, the etching rates of both approaches close to each other. The big difference disappears.

The method of manufacturing the thin-film magnetic head according to the present invention makes use of the above-mentioned characteristics to dramatically improve the etching molding accuracy of the upper magnetic core. Figure 3
(a)-(e) shows the upper magnetic core formation process by ion beam etching in the cross section along the AA line in FIG.

As shown in FIG. 3 (a), the lower magnetic core (1), the gap spacer (3), and the soft magnetic film (21) are provided on the substrate (7).
Are sequentially stacked. The soft magnetic film (21) is made of, for example, Ni-F.
made by e, thickness 1-5μm by sputtering
Is formed in.

Next, as shown in FIG. 3 (b), a metal film (61) made of, for example, Au is sputtered to cover the surface of the soft magnetic film (21),
Alternatively, it is formed to a thickness of 1 to 3 μm by a vapor deposition method.

Thereafter, as shown in FIG. 3C, a resist 8 having a predetermined pattern corresponding to the shape of the upper magnetic core is formed on the surface of the metal film 61. Here, both side walls (81) of the resist (8)
(81) is molded into a highly accurate shape with a wall angle of 90 °. Then, the soft magnetic film (21) is subjected to ion beam etching using the resist (8) as a mask to form a soft magnetic film (22) having a predetermined contour shape as shown in FIG.

At this time, the beam incident angle is set to 0 to 20 ° and the etching rate for the metal film (61) is increased to suppress reattachment of the soft magnetic film (22) as much as possible.

However, this also causes a slight re-adhesion on the soft magnetic film (22) as shown in FIG. 3 (d), and the surface of the soft magnetic film (22) is slightly left on both sides (22a) (22a). However, the metal film (61) remains in the concave portion between these raised portions,
The surface of the soft magnetic film (22) is flattened by the metal film (61).

After that, the soft magnetic film (2
Of 2), ion beam etching is applied only to the area that covers the front gap, and the upper magnetic core is removed as shown in Fig. 3 (e).
Perform the narrowing processing in (2). This makes the head magnetic field steeper.

At this time, the beam incident angle is set to 40 ° to 60 °. As a result, the etching rate of the metal film (61) and the etching rate of the soft magnetic film (22) become substantially the same as shown in FIG. At this time, since the surface of the soft magnetic film (22), which is the etching surface, is flattened by the metal film (61), the soft magnetic film (22) and the metal film (61) are maintained with the flatness maintained. The etching proceeds, and finally the metal film 61 is removed as shown in FIG. 3E to obtain the upper magnetic core 2 having a uniform thickness.

Successively, well-known steps such as formation of a protective layer and processing of a sliding contact surface with a recording medium are completed to complete the thin film magnetic head shown in FIGS.

According to the above manufacturing method, as shown in FIG. 2, it is possible to obtain a thin film magnetic head in which the thickness of the upper magnetic core (2) is uniform and the wall angle is 90 °. Is possible.

The above description of the embodiments is for explaining the present invention, and should not be construed as limiting the invention described in the claims or limiting the scope. The configuration of each part of the present invention is not limited to the above-mentioned embodiment, and it goes without saying that various modifications can be made within the technical scope described in the claims.

For example, the present invention is not limited to a single thin-film magnetic head consisting of only the inductive head chip as described above,
It is also possible to implement the present invention in a composite type thin film magnetic head which is a combination with a magnetoresistive head chip.

[Brief description of drawings]

FIG. 1 is a sectional view of a thin film magnetic head according to the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is a diagram showing an etching molding process of an upper magnetic core.

FIG. 4 is a diagram showing a conventional upper magnetic core molding process.

FIG. 5 is a cross-sectional view showing the structure of a conventional thin film magnetic head during manufacture.

FIG. 6 is a graph showing the relationship between the ion beam incident angle and the etching rate for various metals.

[Explanation of symbols]

 (1) Lower magnetic core (2) Upper magnetic core (3) Gap spacer (4) Insulating layer (5) Coil conductor layer (6) Metal film (7) Substrate

Claims (2)

[Claims] 1. A lower magnetic core (1) for constituting a magnetic circuit.
In a thin film magnetic head in which a gap spacer (3) is interposed between the upper magnetic core (2) and the upper magnetic core (2) to form a front gap portion facing the recording medium, a front gap is formed on the upper surface of the upper magnetic core (2). Metal film except the area that covers the part
(6) is laminated, and the metal film (6) has a characteristic that the etching rate is large when the beam incident angle with respect to the normal direction during ion beam etching is small, and the etching rate is small when the beam incident angle is large. A thin-film magnetic head characterized by being formed of metal. 2. A lower magnetic core (1) which constitutes a magnetic circuit.
In the method of manufacturing a thin film magnetic head in which a gap spacer (3) is interposed between the upper magnetic core (2) and the front magnetic core (2) to form a front gap portion facing the recording medium, a soft magnetic film forming the upper magnetic core (2) is formed. On the surface of the magnetic film (21), a metal film (61) having a characteristic that the etching rate is large when the beam incident angle with respect to the normal direction during ion beam etching is small and the etching rate is small when the beam incident angle is large is formed. And a step of forming a resist (8) having a pattern corresponding to the shape of the upper magnetic core (2) on the surface of the metal film (61), and using the resist (8) as a mask, Soft magnetic film
Ion beam etching is performed on (21) at a small beam incident angle with respect to the normal direction, and in the soft magnetic film (22) formed by etching, a region covering the front gap is covered in the normal direction. And a step of subjecting the front part of the upper magnetic core (2) to a predetermined thickness by ion beam etching with a large beam incident angle.