JPH0758528B2 - Method of manufacturing thin film magnetic head - Google Patents

Description

The present invention relates to a method of manufacturing a thin film magnetic head in magnetic recording.

[Conventional technology]

FIG. 2 shows a conventional perpendicular thin film magnetic head which is an example of this kind of thin film magnetic head. In the drawing, Al ₂ O ₃ --TiC,
The main magnetic pole (2) provided as a partial magnetic pole on the non-magnetic substrate (1) made of sapphire or the like is a main magnetic pole film having a high saturation magnetic flux density and a high magnetic permeability, which is made of a Co-Zr amorphous alloy or the like. (2b) and the main magnetic pole film thickened part (2
It consists of a). A coil (3) made of Cu or the like is formed between the main magnetic pole (2) and the auxiliary magnetic pole (4) as a lower magnetic pole made of CoZr or the like. The coil (3) is Al ₂ O ₃
It is surrounded by the interlayer insulating film (5a). A protective film (5b) of Al ₂ O ₃ is formed on the auxiliary magnetic pole (4).
In b), the Al ₂ O ₃ insulating film (5) is formed together with the interlayer insulating film (5a).

The reason why Al ₂ O ₃ is used for the interlayer insulating film (5a) and the protective film (5b) is that it is excellent in wear resistance and thermal conductivity and has a coefficient of linear expansion almost equal to that of the substrate (1). Al ₂ O ₃ can be said to be the optimum material for such applications, but it has a problem in drilling.

A conventional manufacturing method of this type of head is shown in FIG.
This will be described with reference to (d). FIG. 1A shows a state in which a main magnetic pole (2), an Al ₂ O ₃ insulating film (5) are formed on a substrate (1), and then a Cu coil (3) and an Al ₂ O ₃ insulating film (5) are formed. Is shown. The connection portion (7) with the upper coil is formed thickened. Next, as shown by the broken line (9), flat top polishing is performed, and the same process is repeated again to obtain FIG. Next, FIG.
As shown in FIG. 6, in order to obtain magnetic coupling between the main magnetic pole (2) and the auxiliary magnetic pole (not shown), a portion other than this portion (hereinafter referred to as magnetic pole shunt portion) (6) is formed by photolithography using a photoresist (8). ), And Al ₂ O ₃ is perforated by ion beam etching to obtain the same figure (d). At this time, taper etching can be performed by selecting the incident angle of the ion beam (10) as is well known. The taper is necessary so as not to deteriorate the magnetic characteristics of the auxiliary magnetic pole. After that, an auxiliary magnetic pole film is formed and etched to form a protective film to obtain the magnetic head shown in FIG.

[Problems to be solved by the invention]

As described above, the conventional method for manufacturing a thin film magnetic head has the following problems during the Al ₂ O ₃ drilling process of the magnetic pole connecting portion. That is, the ion beam etching speed of Al ₃ O ₃ is about half that of the photoresist (8), and therefore the photoresist thickness is ₂ times the Al ₂ O ₃ thickness to be etched.
More than double is required. In the case of the head as shown in FIG. 2, the thickness of the coil (3) is 2.5 μm and the thickness of the interlayer Al ₂ O ₃ insulating film (5a) is 1 μm, so the thickness of Al ₂ O ₃ to be etched is 2.5 μm × 2 + 1.
It becomes about μm × 3 = 8 μm. Therefore, the required resist thickness is 16 μm or more. Since it is difficult to perform photolithography accurately with a resist having this thickness, the process of forming a resist mask having a thickness of about 10 μm and performing etching is actually repeated twice. Further, since the etching speed of Al ₂ O ₃ is slow, there is a problem that the etching time is long. Further, it is effective to increase the number of laminated coils (3) in order to increase the head reproduction output.
In this case, the thickness of Al ₂ O ₃ to be etched becomes thicker, and the above problems become a serious obstacle.

The present invention has been made to solve the above-mentioned problems, and can be applied to a multilayer coil without changing the conventional manufacturing method, reducing the number of times of mask formation at the time of drilling the pole shunt portion. An object of the present invention is to obtain a method for manufacturing a thin film magnetic head capable of shortening the manufacturing time.

[Means for Solving Problems] A method of manufacturing a thin-film magnetic head according to the present invention uses a conductive material having a higher etching rate than an Al ₂ O ₃ insulating film instead of etching Al ₂ O ₃ in a magnetic pole shunt portion. Etching. Therefore, a coil material is formed in the magnetic pole shunt portion when forming the coil.

[Action]

In the present invention, when the material to be etched in the magnetic pole shunt portion is changed from Al ₂ O ₃ to, for example, Cu, the ion beam etching rate is increased about 6 times, so that the etching time is
It is shortened to 1/6, and the required resist thickness is about 1/6.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. 1 (a) (b) (c) (d) are shown in FIG. 3 (a).
Corresponding to (b), (c), and (d), the same reference numerals indicate the same parts.

When forming the coil (3) shown in FIG. 1 (a) and increasing the thickness of the upper and lower coil connecting portions (7), a Cu pattern is formed on the magnetic pole shunt corresponding portion (6). However, this pattern is electrically separated from the coil pattern. The same applies when the second layer Cu coil (3) is formed in FIG. In this way, the magnetic pole shunt corresponding portion (6) can be formed of the coil material, but no new process is added for that. Next, as shown in FIG. 3C, using the photoresist (8) as a mask, the Cu of the magnetic pole shunt corresponding portion (6) is formed.
And Al ₂ O ₃ (film thickness of about 1 μm) on the main pole (2) is etched by the ion beam (10). On the main pole (2)
The Al ₂ O ₃ (5) may be removed by ion beam etching in advance after forming the Al ₂ O ₃ film on the main magnetic pole (2) in FIG. It should be noted that the taper is made by selecting the beam incident angle in FIG. 6C as in the conventional example, but the selection angle needs to be changed. As described above, the structure shown in FIG. 9D in which the through hole is formed in the magnetic pole shunt corresponding portion (6) is obtained. After that, an auxiliary magnetic pole film is formed and etched to obtain the magnetic head shown in FIG. At this time, Cu remains on the periphery of the magnetic pole shunt corresponding portion (6) as shown in FIG. 7D, but this does not matter because it is electrically separated from the coil (3). However, when the magnetic characteristics of the magnetic film deteriorate due to the mutual diffusion of the magnetic pole film and the coil film, an Al ₂ O ₃ film with a thickness of about 1 μm is formed after the process shown in FIG. 1D and the photoresist is used as a mask. On the bottom pole
Al ₂ O ₃ may be removed by ion beam etching. Also in this case, since the film thickness of Al ₂ O ₃ to be etched is about 1 μm, the conventional problem does not occur.

Alternatively, as shown in FIG. 1 (c '), the mask opening size is made slightly larger than the Cu size of the magnetic pole shunt equivalent portion (6),
The surrounding Al ₂ O ₃ may also be etched. Even in this case, the taper can be provided.

As described above, if to etching the Cu instead of Al ₂ O _3, since the ion beam Etsu quenching rate of Cu is about six times the _{Al 2 O 3, Al 2 O} 3 in terms of film in the above embodiment The thickness is 7 μm / 6 + 1 μm 2.2 μm, and the required resist thickness is 5 μm or more. With this resist thickness, photolithography can be performed once, and etching only needs to be performed once. Also, the etching time can be reduced to about 1/6.
Further, it is possible to cope with an increase in the number of coil layers. For example,
In case of 4 layers of 2.5μm coil, the film thickness converted to core shunt Al ₂ O ₃ is And the required resist thickness is about 7 μm, which is also 1
Etching can be performed once. If Cu is used,
Since the color is different from that of the CoZr magnetic pole film, there is also an advantage that the etching end point can be easily grasped from the color change.

In the above embodiment, the case where Cu is used for the coil has been described, but the same effect can be obtained by using Au, Al, Ag, or the like.
Further, although the case where the main magnetic pole is formed on the substrate and the auxiliary magnetic pole is formed later is shown, it is needless to say that the invention can be applied to the case where the auxiliary magnetic pole is formed on the substrate and the main magnetic pole is formed later. .

Furthermore, the vertical thin film magnetic head has been described as an example.
The same effect can be obtained even when applied to a conventional thin film magnetic head for longitudinal recording.

〔The invention's effect〕

As described above, according to the present invention, the punched portion of the magnetic pole shunt portion is formed of the coil material made of the conductive material having a higher etching speed than the Al ₂ O ₃ insulating film, and the etching is performed. The time required for this is greatly reduced, the drilling accuracy is improved, and the number of coil laminations can be increased.

[Brief description of drawings]

FIG. 1 is a partial sectional view of a vertical thin film magnetic head for explaining an embodiment of the present invention in the order of steps, FIG. 2 is a partial sectional view of a conventional vertical thin film magnetic head, and FIG. 3 is a conventional thin film. FIG. 7 is a partial cross-sectional view of a vertical thin film magnetic head for explaining the method of manufacturing the magnetic head in the order of steps. (1) is the substrate, (2) is the main pole, (3) is the coil,
(4) is an auxiliary magnetic pole, (5) is an Al ₂ O ₃ insulating film, (6) is a magnetic pole shunt portion, (7) is a coil connecting portion, and (8) is a photoresist. In each figure, the same reference numerals indicate the same or corresponding parts.

Claims (3)

[Claims] 1. A through the Al ₂ O ₃ insulating film between the upper magnetic pole and the lower magnetic pole, the Al ₂ O ₃ thin film magnetic head coil consisting of a large conductive material etching rate than the insulating film is disposed In the manufacturing method, a thin film characterized by forming a pattern of the conductive material at a planned portion of the magnetic pole shunt when forming the coil, and removing the conductive material by ion beam etching to form a through hole for the magnetic pole shunt. Magnetic head manufacturing method. 2. An Al ₂ O ₃ film is formed after forming a through hole,
The method of manufacturing a thin film magnetic head according to claim 1, wherein the Al ₂ O ₃ film on the lower magnetic pole in the through hole is ion beam etched again. 3. The method of manufacturing a thin film magnetic head according to claim 1, wherein the mask opening for ion beam etching is larger than the conductive material.