JP2635670B2 - Thin film magnetic head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to a thin film magnetic head.

(Prior Art) In recent years, demands for higher density, smaller size (multi-track), and mass productivity of a magnetic head used in a magnetic recording / reproducing apparatus have been increasing. Thus, a thin-film magnetic head formed by a thin-film technology is used.

The following are examples of such a thin film magnetic head.

 FIG. 3 is a side sectional view showing a conventional magnetic head.

In FIG. 1, reference numeral 1 denotes a substrate formed of Al ₂ O ₃ TiC or the like. On this substrate 1, a first magnetic layer 2 serving as a lower magnetic core is formed of a magnetic material such as permalloy. An insulating intermediate layer 3 for forming a gap is formed on the first magnetic layer 2. On the insulating intermediate layer 3, an insulating layer 5 with a coil 4 made of Cu or the like interposed is formed. On the insulating layer 5, a second magnetic body 6 which is to be in contact with the first magnetic layer 2 and the insulating intermediate layer 3 and is to be an upper magnetic core is formed. On the substrate 1 including the second magnetic layer 6, a protective layer 7 is formed.

By the way, the performance of the thin-film magnetic head thus configured largely depends on the performance of each magnetic core.

The second magnetic layer 6 serving as the upper magnetic core of the above-described thin-film magnetic head is formed by the coil 4 and the insulating layer 5 on the substrate 1.
It must be formed on a base having a step of about 10 μm. However, since the magnetic layer is usually deposited by a sputtering method, there is a problem that the step coverage is not sufficient.

Therefore, as shown in FIG. 4, the insulating layer 5 is laminated on the insulating intermediate layer 3 formed on the first magnetic layer 2 on the substrate 1, and in the step of forming the coil 4 formed in each layer. At the time of etching, each of the insulating layers 5 is etched so that the end portions thereof are continuously inclined, and the end portions of the insulating layer 5 serving as a base are inclined and processed into a tapered shape of about 60 °. The formation of the second magnetic layer 6 serving as a core is performed.

However, in the above-mentioned conventional thin film magnetic head,
As described above, even if the second magnetic layer 6 is formed after the end of the insulating layer 5 serving as the base of the second magnetic layer 6 is formed to be inclined and then the insulating intermediate layer 3 is formed. Portion c is generated in the boundary between the first magnetic layer 2 and the insulating layer 5 and in the second magnetic layer 6 at the boundary between the first magnetic layer 2 and the insulating layer 5.
As a result, there is a problem that the characteristics of the thin film magnetic head deteriorate.

(Problems to be Solved by the Invention) As described above, in the conventional thin-film magnetic head, there is a problem that a defect occurs in a magnetic layer serving as a magnetic core, and characteristics of the thin-film magnetic head deteriorate.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described problems, and an object of the present invention is to provide a thin-film magnetic head which can prevent defects in a magnetic layer serving as a magnetic core and has excellent characteristics.

[Constitution of the Invention] (Means for Solving the Problems) According to the present invention, an insulating layer having a coil pattern interposed is formed on a first magnetic layer, and a second magnetic layer is formed on the insulating layer. In the formed thin-film magnetic head, the insulating layer is formed of a silicon oxide film, and the oxidation concentration of the silicon oxide film on the side close to the magnetic layer with respect to the thickness direction of the insulating layer is made smaller than the oxygen concentration of the non-close portion. It is a smaller one.

(Operation) In the present invention, the insulating layer is formed of a silicon oxide film, and the oxygen concentration of the silicon oxide film on the side close to the magnetic layer is smaller than the oxygen concentration of the silicon oxide film of the non-close portion. As a result, the edge of the insulating layer is loosened by the etching in the step of forming the coil pattern in the insulating layer, which is a silicon oxide film, so that the occurrence of defects in the magnetic layer serving as the magnetic core can be prevented, and the characteristics can be improved. A thin film magnetic head can be provided.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a side sectional view showing a thin-film magnetic head according to one embodiment of the present invention.

In the figure, reference numeral 21 denotes a substrate formed of Al ₂ O ₃ TiC or the like. A first magnetic layer 22 serving as a lower magnetic core is formed of a magnetic material such as permalloy on the substrate 21. An insulating intermediate layer 23 for forming a gap is formed on the first magnetic layer 22. On the insulating intermediate layer 23, an insulating layer 25 having a coil pattern 24 made of Cu or the like interposed is formed. On the insulating layer 25, a second magnetic layer 26 serving as an upper magnetic core is formed in contact with the first magnetic layer 22 and the insulating intermediate layer 23. Second
The protective layer 27 is formed on the substrate 21 including the magnetic layer 26.

 The above-described insulating layer 25 is formed as follows.

FIG. 2 is a side sectional view for explaining the insulating layer 25.

As shown in the figure, a first insulating layer 25a is formed on an insulating intermediate layer 23 formed on a first magnetic layer 22 on a substrate 21. The first insulating layer 25a has an oxygen concentration of about 55a
It is formed of a silicon oxide film of t%. The coil pattern 24 is formed on the first insulating layer 25a by a photolithography technique and an electric field selective plating technique. In the etching step for forming the coil pattern 24, the end of the first insulating layer 25a has an inclined tapered shape.

Next, a second insulating layer 25b is formed over the first insulating layer 25a. This second insulating layer 25b is formed of a silicon oxide film having an oxygen concentration of about 65 at%. The coil pattern 24 is also formed on the second insulating layer 25b by photolithography and electric field selective plating. In the etching step for forming the coil pattern 24, the end of the second insulating layer 25b is tapered and has a steeper slope than the slope of the first insulating layer 25a. .

Thereafter, a third insulating layer 25c is formed on the second insulating layer 25b. This third insulating layer 25c is formed of a silicon oxide film having an oxygen concentration of about 55 at%. And this third
A photoresist film having a predetermined shape is formed on the insulating layer 25c by photolithography, and in the step of etching the photoresist film, the end of the third insulating layer 25c is connected to the first insulating layer 25a. The tapered shape is the same as that described above.

As described above, the etching rate of the first and third insulating layers 25a and 25c is about 20% lower than the etching rate of the second insulating layer 25b, and as shown in FIG. relationship between the inclination angle theta ₂ of the first and third insulating layers 25a, 25c inclined angle theta ₁ and the second insulating layer 25b, since the theta _{1 <theta 2,} a substantially S-shaped inclined surface and Become.

Therefore, the second magnetic layer 26 formed on the insulating layer 25 including the first to third insulating layers 25a, 25b, and 25c can be favorably formed along a gentle slope. Thereby, a thin film magnetic head having good characteristics can be obtained.

In the above-described embodiment, the case where the insulating layer 25 has three layers has been described. However, the insulating layer may be a single layer formed continuously, or may be a plurality of other layers.

[Effects of the Invention] As described above, in the thin-film magnetic head of the present invention, the insulating layer is formed by the silicon oxide film, and the oxygen concentration on the side of the silicon oxide film which is close to the magnetic layer is not reduced. Since the oxygen concentration in the portion of the silicon oxide film is smaller than that of the silicon oxide film, the edge of the insulating layer becomes loose due to the etching in the coil pattern forming step in the insulating layer which is the silicon oxide film, thereby causing defects in the magnetic layer serving as the magnetic core. Can be prevented, and a thin-film magnetic head having good characteristics can be provided.

[Brief description of the drawings]

1 is a side sectional view showing a thin film magnetic head according to one embodiment of the present invention, FIG. 2 is a side sectional view for explaining an insulating layer of FIG. 1, and FIG. 3 is a conventional thin film magnetic head. FIG. 4 is a side sectional view for explaining the insulating layer of FIG. 21 ... substrate, 22 ... first magnetic layer, 23 ... insulating intermediate layer, 24 ... coil pattern, 25 ... insulating layer, 25a ... first insulating layer, 25b ... second insulating Layer 25c Third insulating layer 26 Second magnetic layer 27 Protective layer.

Claims (1)

(57) [Claims] 1. A thin-film magnetic head in which an insulating layer having a coil pattern interposed thereon is formed on a first magnetic layer, and a second magnetic layer is formed on the insulating layer. A thin-film magnetic head formed of an oxide film, wherein an oxidation concentration of the silicon oxide film in the thickness direction of the insulating layer, which is close to the magnetic layer, is smaller than an oxygen concentration of a portion not close to the magnetic layer.