JP2897434B2 - Thin film magnetic head - Google Patents

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 mounted on a magnetic disk drive.

[0002]

2. Description of the Related Art As the processing power of computers increases,
The storage capacity of magnetic disk devices has been increasing.

For this reason, the shape of the tip of the track of the magnetic core of the thin-film magnetic head mounted on the magnetic disk drive tends to be small and complicated. Further, a high level of manufacturing accuracy is also required. The structure of the thin-film magnetic head will be described with reference to FIGS. 1 and 2 are a perspective view and a sectional view showing a sectional structure of a main part of the thin-film magnetic head. A lower magnetic film 22 is formed on a substrate 21, and an upper magnetic film 23 formed later is formed.
Together, they constitute a magnetic core forming a magnetic circuit.
At the tip 24, a magnetic gap is formed by interposing an insulating layer 25 made of a nonmagnetic material between the upper magnetic film 23 and the lower magnetic film 22. Upper magnetic film 23 and lower magnetic film 22
The information is written to and read from the magnetic disk by using the magnetic gap.

On the other hand, at the center of the magnetic core, a conductor coil 2
6 is provided so as to intersect the magnetic circuit, and the conductor coil 26 is formed of the upper magnetic film 23 and the lower magnetic film 22 and the insulating film 2.
7 insulated. The upper part of the element is covered with an element protection film 28.

The recording density of a thin-film magnetic head is mainly determined by the shape of the tip portion 24. In particular, the width d of the upper magnetic film 23 which determines the track width and the pole length t which determines overwriting and resolution (the upper magnetic film 23 and the lower magnetic (The sum of the thicknesses of the film 22 and the magnetic gap 25) must be formed with high precision. Among them, the thickness of the magnetic gap 25 related to the value of t tends to become thinner.

Conventionally, an inorganic insulating film used for the magnetic gap is formed by a sputtering method as disclosed in Japanese Patent Publication No. 2-24924.

[0007]

In the prior art, an inorganic insulating film having a magnetic gap is formed by a sputtering method. In the sputtering method, the film structure is always a columnar structure due to its film forming method,
The film cannot be made denser than a certain degree. For this reason, there has been a problem that the thickness of the inorganic insulating film in the magnetic gap must be increased to a certain degree or more. Further, when the inorganic insulating film is formed by the sputtering method, there is a problem that the lower magnetic film is deteriorated by the sputtering and the magnetostriction constant of the magnetic film changes.

An object of the present invention is to provide a high-performance thin-film magnetic head in which the pole length t is formed with high precision.

[0009]

In order to achieve the above object, in the present invention, a new method of adding a light irradiation to a method of synthesizing an inorganic film called a sol-gel method has been developed. This is applied to high precision processing. A feature of the present invention is that, when forming a gap layer which is an inorganic film in a thin-film magnetic head, a solution containing a metal alkoxide is applied to a magnetic film, and a metal-alkoxy group of the metal alkoxide is applied to a film obtained by applying the solution. Against join
The purpose is to apply the corresponding energy by light irradiation . By using this method, an inorganic film having a dense and continuous structure can be formed at a low temperature. For this reason, the thickness of the gap layer, which is an inorganic film, can be made thinner than that formed by a conventional sputtering method. Also, there is no deterioration of the lower magnetic film due to sputtering. In addition, since the film can be formed at a low temperature, there is no fear of peeling of the film due to a difference in thermal expansion coefficient between the inorganic film and the lower magnetic film. As described above, a high-performance and highly reliable thin-film magnetic head can be provided.

[0010]

The metal alkoxide used in the present invention has the general formula M (OR) n (M: metal, R: alkyl group, n: integer)
It is a substance represented by The metal alkoxide absorbs the energy of the reaction in the presence of water to cause a hydrolysis reaction (R
O) A compound having a structure in which a part of an alkoxy group represented by n ₁ MOH is substituted with a hydroxyl group is produced. As described above, the intermediate produced by partial hydrolysis further reacts with another metal alkoxide to grow as a condensation product as shown in FIG. The sol-gel method synthesizes an inorganic polymer, that is, an oxide, based on the above-described chemical reaction, that is, a hydrolysis reaction and a condensation reaction. It is said that the rate-determining step of the sol-gel reaction is cleavage of the metal-alkoxy group bond during the hydrolysis reaction.

In the present invention, energy corresponding to the metal-alkoxy group bond is applied by light irradiation to selectively cut the metal-alkoxy group bond, thereby completing the sol-gel reaction in an ideal state. is there. In addition, a thin film formed on a substrate is irradiated with light having a wavelength for generating ozone by using a reaction solution, and a small amount of organic matter remaining in the film is oxidized with ozone to further reduce organic matter in the film. .

The technique of obtaining an oxide thin film having a uniform stoichiometric ratio at a low temperature by adding light irradiation to the sol-gel reaction in this manner is called a light-assisted sol-gel method. In this method, heat treatment for improving film quality after film formation is not required, and a film can be formed on an organic substrate having a low heat-resistant temperature or a substrate having a large difference in thermal expansion coefficient. In addition, this method
After the application of the solution, light irradiation is performed using a mask, so that an inorganic film can be formed only on necessary portions.

According to the present invention, since an inorganic polymer having a certain molecular weight is already formed in a solution, a very dense film can be produced as shown in FIG. For this reason, the inorganic film of the gap layer can be made thinner than the conventional one, which leads to an improvement in the performance of the thin-film magnetic head. In the conventional sputtering method, due to an essential problem of the film forming method, the structure of the film always has a columnar structure, and the film cannot be denser than a certain degree. For this reason, the gap layer becomes thick, and a thin-film magnetic head having good performance cannot be obtained.

Further, according to the present invention, a film can be formed by a simple apparatus without using an expensive vacuum chamber or the like such as a sputtering method.

[0015]

Embodiments of the present invention will be described below.

Embodiment 1 FIG. 3 shows a manufacturing process of a thin-film magnetic head. In the figure, 1 is a lower magnetic film, 2 is a gap layer, 3 is a photoresist film, 4 is a coil, 5 is an upper magnetic film, 6 and 8 are inorganic films, and 7 is an upper magnetic film. A photoresist is used as a coil interlayer insulating film of the thin film magnetic head,
A permalloy film was used as the magnetic film, and an alumina film was used as the inorganic film. A zirconia substrate was used as the substrate of the thin-film magnetic head, that is, the slider material. The magnetic film and the alumina film were formed by a sputtering method, and the photoresist was formed by a coating method.

The gap layer forming process will be described below. The sol-gel film used in this process is prepared as follows.

0.5 mol / l of tantalum ethoxydono
Was prepared. 16 ml of a 0.5 mol / l ethanol solution of water and 0.0 ml of hydrochloric acid were added to 4 ml of this solution.
A solution obtained by adding 4 ml of ethanol to a mixed solution of 0.5 ml of a 1 mol / l ethanol solution was dropped at a rate of 3 ml / min to obtain a transparent homogeneous solution. This mixed solution was stirred for 30 minutes. This solution was applied on the lower magnetic film 1 using a spinner to form a sol-gel film 9. Then, a film corresponding to the binding energy of the tantalum-alkoxy group is added to the film.
Light of 54 nm was irradiated for 15 minutes. At this time, a film was cured by irradiating light only to a necessary portion using a mask. Unnecessary parts were dissolved in ethanol and removed. Then, the film was irradiated with light of 184 nm to oxidize the film with ozone. The inorganic insulating film was formed on the gap layer 2 as described above.
The thickness of this film was 2,000 angstroms, which is half the thickness of the conventional one.

Thereafter, an interlayer insulating film, a coil, a magnetic film, and the like were formed by an ordinary method to complete a thin-film magnetic head. Since the gap layer of the thin-film magnetic head is thin, the resolution is improved as compared with the conventional one.

[0020]

According to the present invention, since a thin and dense inorganic insulating film can be formed at a low temperature, the gap layer of the thin-film magnetic head can be made much thinner than the conventional one. Therefore, a high-performance and highly reliable thin-film magnetic head can be obtained. Since the lower magnetic film is not deteriorated by sputtering, a magnetic film having a high magnetostriction constant can be obtained. In addition, since the film can be formed at a low temperature, there is no fear of peeling of the film due to a difference in thermal expansion coefficient between the inorganic film and the lower magnetic film. Further, since the pole length can be reduced and the margin of the gap width variation can be reduced, it is possible to cope with ultra-high density of the thin film magnetic head. more than
Provide thinner magnetic heads with higher performance and higher reliability
Wear.

[Brief description of the drawings]

FIG. 1 is a perspective view of a general thin-film magnetic head.

FIG. 2 is a sectional view of a general thin-film magnetic head.

FIG. 3 is an explanatory view of a gap layer forming process.

FIG. 4 is a cross-sectional view of a sol-gel film.

FIG. 5 is a structural explanatory view of a condensation product.

[Explanation of symbols]

21: substrate, 22: lower magnetic film, 23: upper magnetic film, 2
4 ... tip, 25 ... gap layer, 26 ... conductor coil, 2
7 ... inorganic insulating film, 28 ... element protection film.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G11B 5/31

Claims (1)

(57) [Claims] 1. A method for manufacturing a thin-film magnetic head having a conductor coil, an insulating layer, and a gap layer which is an inorganic film between two magnetic films. In forming the gap layer, a solution containing a metal alkoxide is mixed with the magnetic layer. A metal-alkoxy of the metal alkoxide is applied to a film formed by applying the solution to the film;
A method of manufacturing a thin-film magnetic head, wherein energy corresponding to a base bond is applied by light irradiation .