JP2654743B2 - Method of manufacturing thin-film magnetic head for hard disk - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a thin-film magnetic head for a hard disk, and more particularly, to a method of forming a plasma polymerized film on a magnetic film formed by an electroplating method and performing wet etching. The present invention relates to a method for forming a magnetic pole pattern by protecting a main magnetic film with the plasma polymerized film.

[0002]

2. Description of the Related Art A thin film magnetic head for a hard disk has a structure in which upper and lower two magnetic films (magnetic pole patterns) provided on a substrate are separated by a gap film, and a coil film for generating a magnetic field and for inducing an induced current is provided therebetween. ing. As the substrate, a mixed ceramic of Al ₂ O ₃ (aluminum oxide) and TiC (titanium carbide) having high hardness and high electric conductivity is used as the ceramic, and the surface thereof is made of Al ₂ O 3.
_The one provided with the protective layer of ₃ is used. A permalloy (FeNi alloy) thin film is used as the magnetic film. As a method of forming a thin film, there are a sputtering method and an electroplating method, and the electroplating method has an advantage that a film can be formed at a temperature around room temperature.

FIG. 2 shows an example of a conventional magnetic pole pattern forming process.
A to G show. As described above, the substrate 10 is made of Al
Al ₂ O ₃ protective layer 1 on the surface of ₂ O ₃ —TiC substrate 11
2 is used. A conductive film 14 is formed on the substrate 10 by an evaporation method, and a photoresist pattern 16 is provided to form a main magnetic film portion (see A). Next, as shown in B, a magnetic film (permalloy or the like) 18 is formed by electroplating. The center is a main magnetic film 18a serving as a magnetic pole pattern of the thin-film magnetic head, and both sides are unnecessary magnetic films 18b which function as a yoke in an electroplating process. As shown in C, the photoresist pattern is removed, and as shown in D, the conductive film in the portion without the magnetic film 18 is removed by ion milling (ion beam etching). Next, as shown in E, the main magnetic film 18a
Is protected by covering with a photoresist pattern 20, and the unnecessary magnetic film is removed by a wet etching method (see F). Finally, as shown by G, the photoresist pattern is removed.

[0004]

However, during the above process,
In the unnecessary magnetic film removing step by wet etching in FIG. 2F, the main magnetic film 18a was etched, and there was a problem that the magnetic pole pattern collapsed. This is shown in FIG. This is a reproduction of an enlarged photograph of an example of a defective product. Main magnetic film (magnetic pole pattern) 18a
An etched portion 22 is formed in a part of. As a result of studying the cause, it was found that the photoresist pattern was lifted. In the photoresist, the step portion becomes considerably thin, and the degree of adhesion tends to be insufficient. In FIG. 2E, a gap is formed between the photoresist and the protective layer 12 (indicated by g), and the etchant penetrates. This is because the portion to be protected is etched.

An object of the present invention is to provide a thin film for a hard disk which is capable of removing an unnecessary magnetic film by wet etching without causing the shape of the main magnetic film (magnetic pole pattern) to be distorted and greatly improving the yield. An object of the present invention is to provide a method for manufacturing a magnetic head.

[0006]

According to the present invention, a conductive film is formed on a substrate, a photoresist pattern is provided thereon, a magnetic film is formed by electroplating, and the unnecessary magnetic film is wet-etched. In the method of removing by a method, a plasma polymerized film is formed on a magnetic film formed by an electroplating method, the plasma polymerized film on the unnecessary magnetic film is removed by a dry etching method, and then the exposed unnecessary magnetic film is wet-etched. This is a method for manufacturing a thin-film magnetic head for a hard disk in which a magnetic pole pattern is generated by removing the magnetic pole pattern.

[0007]

According to the present invention, before the unnecessary magnetic film is wet-etched, the main magnetic film is protected by covering it with a plasma polymerized film. The plasma polymerized film was highly crosslinked 3
It has a three-dimensional stitch structure, excellent mechanical strength (hardness),
Since it has high adhesion strength and excellent chemical resistance (does not dissolve in acid or alkali), it can prevent the penetration of the etching solution and is suitable as a protective film. In addition, a uniform film can be obtained regardless of the presence or absence of a step, and the film can be formed even on a three-dimensional structure. This plasma-polymerized film exhibits a desired effect at a thickness of several hundreds of meters, and since it is a non-magnetic film, there is no need to remove it after forming the film.

This plasma polymerized film covers and protects the main magnetic film, prevents the penetration of the etching solution, prevents erosion due to etching, and enables a magnetic pole pattern of a predetermined shape to be generated with high yield.

[0009]

1A to 1H show an embodiment of a magnetic pole pattern forming step in a method of manufacturing a thin film magnetic head for a hard disk according to the present invention. The steps from A to D in the same drawing may be exactly the same as the above-described conventional steps. Again substrate 1
0, the surface of the Al ₂ O ₃ —TiC substrate 11
_The one provided with a protective layer 12 of ₂ O ₃ is used. A conductive film 14 is formed on the substrate 10 by a vapor deposition method, and a photoresist pattern 16 is provided to form a main magnetic film portion (see A). Next, as shown in B, a magnetic film (permalloy or the like) 18 is formed by electroplating. The central portion is a main magnetic film 18a serving as a magnetic pole pattern, and both sides are unnecessary magnetic films 18b which function as a yoke in an electroplating process. Then, as shown in C, the photoresist pattern is removed, and as shown in D, the conductive film in the portion without the magnetic film is removed by ion milling (ion beam etching).

In the present invention, as shown by E, the magnetic film 1
A plasma polymerized film 30 is formed on the substrate 8 by a DC plasma pulse discharge method. At that time, a hydrocarbon-based gas (for example, methane or ethylene) is used alone or as a mixture as a monomer. This plasma polymerized film 30
Is a diamond-like carbon film having excellent mechanical strength (hardness), high adhesion strength, and a property of not dissolving in acids or alkalis. In addition, as shown in the figure, a substantially uniform film can be obtained regardless of the presence or absence of a step. The thickness of the plasma polymerized film may be several hundreds of square meters. Then, the main magnetic film 18a is protected by covering it with the photoresist 32 (see F), and the unnecessary plasma polymerized film (the portion not covered with the photoresist 32) such as the unnecessary magnetic film 18b is dry-etched by ion milling or the like. (See G), and the photoresist pattern is removed. Finally, as shown in H, the unnecessary magnetic film is removed by a wet etching method. Since the plasma polymerized film 30 is a non-magnetic film, it may be left as it is.

The plasma polymerized film 30 functions as a resist during wet etching, and prevents the etchant from penetrating into the main magnetic film due to its high adhesion to the substrate 10. Therefore, as shown in FIG. 3, the shape of the main magnetic film 18 does not collapse, and a magnetic pole pattern having a desired shape can be generated with high yield. FIG. 3 is an enlarged photograph of an example of a product obtained by the method of the present invention.

[0012]

As described above, the present invention uses a plasma-polymerized film as a resist in a wet etching process, so that its excellent film characteristics and adhesion can be utilized, and the wet etching method is used. Nevertheless, the main magnetic film is not etched, the shape does not collapse, and a desired magnetic pole pattern can be formed with high yield.

[Brief description of the drawings]

FIG. 1 is a process explanatory view showing one embodiment of a magnetic pole pattern forming process according to the present invention.

FIG. 2 is a process explanatory view showing an example of a process of forming a magnetic pole pattern in a conventional technique.

FIG. 3 is an enlarged schematic view showing an example of a magnetic pole pattern of a product according to the present invention.

FIG. 4 is an enlarged schematic view showing an example of a magnetic pole pattern of a defective product according to the related art.

[Explanation of symbols]

10 substrate 11 Al ₂ O ₃ -TiC substrate 12 Al ₂ O ₃ protective layer 14 conductive film 16 a photoresist 18 magnetic film 18a main magnetic film 18b unwanted magnetic layer 20 photoresist 30 plasma polymerized film 32 a photoresist

Claims (1)

(57) [Claims] In a method of forming a conductive film on a substrate, providing a photoresist pattern thereon, forming a magnetic film by electroplating, and removing unnecessary magnetic film portions by wet etching, After forming a plasma polymerized film on the magnetic film formed by plating and removing the plasma polymerized film on the unnecessary magnetic film by dry etching, the exposed unnecessary magnetic film is removed by wet etching to generate a magnetic pole pattern A method of manufacturing a thin-film magnetic head for a hard disk.