JPS62128109A - Manufacture of high-permeability laminating film - Google Patents

Abstract

PURPOSE:To improve permeability and frequency characteristics, by impressing a specific amount of static magnetic field parallel to a substrate plane, when amorphous thin films are formed, so that permeability of each amorphous soft magnetic film is improved. CONSTITUTION:When amorphous soft magnetic films are manufactured by a RF sputtering method or the like, a substrate material, an external magnetic field such as earth magnetism, an Ar gas-introduced effect, and the like cause magnetic anisotropy inside film planes. Then, an effect of stress between magnetic films and a substrate can be removed by heat treatment, however, it is hard to remove a magnetic effect fully by only heat treatment. Therefore, a sputtering process is performed by impressing a static magnetic field parallel to the substrate surface when the films are manufactured, to improve several characteristics. The impressed magnetic field less than 3Oe becomes ineffective, and that more than 50Oe has an effect on plasma during sputtering. Thus, the magnetic field of 3Oe to 50Oe becomes desirable. Hence, permeability used in a high frequency device such as a magnetic head can be made large, capable of improving frequency characteristics in a high frequency region.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for manufacturing a high magnetic permeability laminated film used in high frequency devices such as magnetic heads.

[Prior art]

In recent years, research has been actively conducted on the production of amorphous magnetic alloy thin films using sputtering methods, vapor deposition methods, and the like.

Among them, co has low magnetostriction and high saturation magnetic flux density.
-Zr-based amorphous alloy thin films are attracting attention as materials for forming magnetic heads for VTRs, magnetic heads for perpendicular recording, thin film magnetic heads, etc. (Japanese Unexamined Patent Publications No. 57-51236 and No. 58-27941). In order to improve the magnetic permeability of the magnetic thin film, heat treatment is performed in a rotating magnetic field, and amorphous magnetic thin films are laminated with an intermediate layer made of an insulator such as Si02 interposed between each magnetic layer. High permeability laminated films are also being produced that reduce eddy current loss and improve magnetic permeability in the high frequency range by reducing the thickness (Japanese Patent Application Laid-Open No.
8-185742).

(Problems to be Solved by the Invention) However, although the magnetic permeability of the thin film thus obtained was improved from that at the time of production, it was still insufficient for practical use. In general, it is said that in thin films produced by sputtering or vapor deposition, strain remains in the film plane due to differences in thermal expansion coefficients between the substrate and the thin film, and as a result, magnetic permeability decreases. In reality, even in magnetic thin films whose composition has almost zero magnetostriction, the magnetic permeability after heat treatment does not improve much. The reason why this phenomenon occurs is
This is thought to be because the magnetic anisotropy induced during fabrication still remains after heat treatment. In addition, since the anisotropy remaining in the film plane of this film is uniaxial magnetic anisotropy, it is suitable as a main pole film of a magnetic head for perpendicular recording. It is unsuitable as a magnetic thin film for use in mold heads.

In addition, although the frequency characteristics of the magnetic permeability of each magnetic layer in the laminated film described above have been improved, in this case as well, not only does uniaxial magnetic anisotropy exist within the film plane, but also the magnetic permeability is reduced due to the thin film thickness. Since the absolute value of is decreasing, it has been difficult to obtain a practically excellent high permeability laminated film unless the magnetic permeability of each magnetic layer is improved.

(Means for Solving the Problems) An object of the present invention is to solve the above-mentioned conventional problems and provide a method for manufacturing a high magnetic permeability laminated film that improves high magnetic permeability and magnetic permeability characteristics in a high frequency region. By providing the method described in the claims,
The above objective can be achieved. That is, the present invention
A highly permeable film formed by laminating an amorphous soft magnetic thin film on a substrate made of at least one of a nonmagnetic material and a magnetic material with an intermediate layer made of a nonmagnetic material interposed therebetween using a sputtering method. In the method for manufacturing a magnetic laminated film, when forming the amorphous thin film, a static magnetic field of 30e or more and 5000 or less parallel to the substrate surface is applied to improve the magnetic permeability of each amorphous soft magnetic film. This invention relates to a method for manufacturing a high permeability laminated film with high magnetic permeability and improved frequency characteristics, and furthermore, by changing the direction of the applied static magnetic field for each layer of the amorphous soft magnetic thin film, the method has excellent high frequency characteristics and the like. The present invention relates to a method for manufacturing a multilayer film with high magnetic permeability.

Next, the present invention will be explained using experimental data.

When producing an amorphous soft magnetic film by RF sputtering,
It is generally well known that magnetic anisotropy is induced in the film plane due to the influence of the substrate material, external magnetic field such as terrestrial magnetism, and the incorporation of Ar gas.

Among these, the present inventors have confirmed that although the influence of stress between the magnetic film and the substrate can be removed by heat treatment, it is difficult to sufficiently eliminate the magnetic influence only by heat treatment.

Therefore, the present inventors first performed sputtering by applying a static magnetic field parallel to the substrate surface during film fabrication, and fabricated a film with uniaxial magnetic anisotropy with the direction of the applied magnetic field as the axis of easy magnetization. We examined the characteristics.

Figure 1(a) shows 0O8sNb12Z, which has a composition of almost zero magnetostriction, fabricated on a glass substrate by RF sputtering.
FIG. 3 is a diagram showing the relationship between the magnetic permeability at I MHz and the direction of the applied magnetic field in an rs amorphous magnetic thin film, and FIG. It is. Here, the magnitude of the static magnetic field applied during thin film fabrication was approximately 600 S, and the thickness of the above thin film was 0.6 μm.
It is.

As can be seen from the figure, the amorphous thin film has a large in-plane anisotropy, and the magnetic permeability has a uniaxial anisotropy with a large value in the direction of the hard axis of magnetization.

The solid line in Figure 2 shows the frequency dependence of the magnetic permeability in the direction of the hard axis of magnetization of the thin film, and for comparison, an amorphous thin film was prepared with the same composition as the above thin film without applying a magnetic field during sputtering. The magnetic permeability is also indicated by a dotted line in the figure. However, in each case, after fabrication, the magnetic permeability was measured after heat treatment in a rotating magnetic field. As can be seen from the figure, for magnetic thin films with magnetostriction near zero, the applied magnetic field during fabrication is 60e.
In this case, μ, = 10000 (at 10
kHz), and a high value was obtained in the high frequency range of μm=8500 at I MHz as well.

Here, the applied magnetic field during the production of the amorphous thin film was 30e
If it is less than 300e, there will be no effect, and if it is more than 500e, it will affect the plasma during sputtering.
It is necessary to set the value to be between e and 500e.

〔Example〕

Next, the present inventors et al. deposited an amorphous magnetic thin film having the above composition at 0.00%.
A high magnetic permeability laminated film was prepared by alternately laminating 10 layers of 5i02 with a thickness of 2 μm and an intermediate layer of 701 mm.

In this example, in order to fabricate an isotropic magnetic film, the direction of the applied magnetic field was changed for each magnetic layer as shown in FIGS. 3(a) and 3(b). Sputtering was performed by changing the direction of the magnetic field so that it was directed in 10 directions shifted by 18 degrees when viewed from the top surface of the film. Here, the magnitude of the applied magnetic field is 60e, and the thickness of the produced film is approximately 2μ.
It was m. Note that FIG. 3B is a diagram showing a cross section of the same figure (ml).

FIG. 4(a) is a diagram showing the dispersion of the magnetic permeability of the laminated film in each in-plane direction, and FIG. FIG. As can be seen from Figure 1(a), in this high permeability multilayer film, the easy axis direction of magnetization differs for each layer of the amorphous thin film, so the QoN shown in Figure 1(a)
It can be seen that it is significantly more isotropic than the bZr single layer film.

The solid line in Figure 5 shows the frequency dependence of the magnetic permeability of the laminated film. It can be seen that the magnetic permeability is higher than that of ), and the high frequency characteristics of I MHz or higher are also far superior.

(Effects of the Invention) As described above, according to the present invention, a high magnetic permeability laminated film that is used in high frequency devices such as magnetic heads and has high magnetic permeability and greatly improved frequency characteristics in the high frequency region can be manufactured. I can do it.

[Brief explanation of drawings]

Figure 1 (a) shows the dispersion of magnetic permeability in each direction within the film plane of a 0oNbZr amorphous magnetic thin film fabricated by sputtering in a static magnetic field, and Figure 1 (b) shows the easy axis of magnetization for the sample. A diagram showing the relationship between the direction and the permeability measurement direction,
FIG. 2 is a diagram showing the frequency dependence of the magnetic permeability of the thin film, FIG.
Figure 4 (b) is a diagram showing the cross section of Figure 4 (a), Figure 4 (a) is a diagram showing the dispersion of magnetic permeability in each direction within the film plane of the laminated film, and Figure 4 (b) is a diagram showing the distribution of magnetic permeability in each direction within the film plane of the laminated film. FIG. 5 is a diagram showing the relationship between the direction of μr (max) and the magnetic permeability measurement direction, and FIG. 5 is a diagram showing the frequency dependence of the magnetic permeability of the laminated film.

Claims (1)

[Claims] 1. An amorphous soft magnetic thin film is laminated by sputtering on a substrate made of at least one of a nonmagnetic material and a magnetic material, with an intermediate layer made of a nonmagnetic material interposed therebetween. A method for manufacturing a high permeability laminated film formed by applying a static magnetic field of 3 Oe or more and 50 Oe or less parallel to the substrate surface when forming the amorphous thin film. A method for manufacturing a magnetic laminated film. 2. The method of manufacturing a high magnetic permeability laminated film according to claim 1, wherein the direction of the applied static magnetic field is changed for each layer of the amorphous soft magnetic thin film.