JPH1154324A - Deposition source for forming soft magnetic thin film by vacuum deposition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a magnetic head suitable for high density recording at a high yield, by suppressing the concentration of a gas contained in a deposition source composed of cobalt-iron-nickel alloy at a specific wt.% or below. SOLUTION: A material prepared by mixing alloy materials, i.e., cobalt, iron and nickel, at specified wt.% is put in a platinum pot. The pot is contained in a vacuum furnace to be heated, and the alloy material is melted and mixed. At that time, the vacuum inside the furnace is kept at 4×10<-6> Torr or lower. Thus, even when a gas of a slight quantity is generated inside the alloy material, the gas does not stay on the surface of the source to form a film as the material is in the vacuum atmosphere, and the gas goes out to the atmosphere. When the degassing is not sufficiently obtained even in vacuum, HIP process (the alloy material is compressed to degas) is performed as the degassing process from molten metal. Thus, the concentration of the gas contained in the manufactured deposition source (cobalt-iron-nickel alloy ingot) is kept at 0.005 wt.% or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of manufacturing a core of a magnetic head corresponding to high-density recording, and more particularly to a deposition source for forming a soft magnetic thin film by a vacuum deposition method.

[0002]

2. Description of the Related Art In the field of magnetic recording devices for computers such as hard disk devices and floppy disk devices, in order to realize larger capacity storage with smaller devices.
Endless technologies are being developed for high-density recording from various angles. A typical conventional magnetic head core used in this type of magnetic recording apparatus is a binary soft magnetic thin film such as a nickel-iron alloy formed on an appropriate substrate by an electron beam heating vacuum evaporation method. Met.

[0003] As a magnetic head core material for realizing higher density recording, a conventional nickel-iron alloy has become an insufficient material in terms of saturation magnetic flux density (10000 gauss or less). Therefore, attention has been focused on ternary soft magnetic materials having a higher saturation magnetic flux density, such as cobalt-iron-nickel alloys.

[0004]

The present inventors have also proposed a cobalt-iron-nickel alloy (17000) having a high saturation magnetic flux density.
(It will be about Gaussian), and research and development have been continued to manufacture a magnetic head core corresponding to high density recording with this material. First, a nickel-iron alloy is replaced with a cobalt-iron-nickel alloy, and a soft magnetic thin film for a magnetic head core is formed on an appropriate substrate by an electron beam heating vacuum evaporation method similar to the conventional method, and the film is formed. The state was analyzed and the characteristics as a magnetic head were measured in detail.

As a result, when a thin film was formed using a conventional nickel-iron alloy as a deposition source, a uniform thin film could be formed with a stable deposition rate. In the case of replacing with a nickel alloy, the deposition rate fluctuates and a uniform thin film cannot be formed.
Therefore, the desired characteristics as a magnetic head core could not be realized.

SUMMARY OF THE INVENTION The present invention has been made in view of the above background, and an object of the present invention is to solve the above-mentioned problem and to form a uniform thin film of a cobalt-iron-nickel alloy having a high saturation magnetic flux density by an electron beam. An object of the present invention is to make it possible to manufacture a magnetic head core suitable for high-density recording with good yield by being formed stably by a heating type vacuum evaporation method.

[0007]

The inventors of the present invention have determined why the deposition rate fluctuates when a thin film is formed by electron beam heating vacuum deposition using a cobalt-iron-nickel alloy as a deposition source. Was analyzed from various viewpoints. As a result, it has been found that there is a strong relationship between the variation of the deposition rate and the concentration of the gas contained in the deposition source.

[0008] A deposition source of a cobalt-iron-nickel alloy is manufactured by mixing and melting each metal material in a vacuum to form an alloy. The degassing process is performed while mixing the molten metal in the melting process in the vacuum. At this time, if the degree of vacuum is not good or if the degassing process is not sufficiently performed, the concentration of the gas contained in the formed deposition source (alloy ingot) becomes high. The main gases contained in the alloy ingot are oxygen and nitrogen.

It has been found that when the concentration of the gas contained in the deposition source of the cobalt-iron-nickel alloy exceeds 0.005% by weight, the variation in the deposition rate becomes significant. Conversely, if the concentration of the gas contained in the deposition source of the cobalt-iron-nickel alloy is suppressed to 0.005% by weight or less, the variation in the deposition rate falls within the allowable range, and a sufficiently uniform deposited film is stably formed. It was found that it could be formed.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of a method for manufacturing a deposition source according to the present invention will be described. A mixture of alloy materials of cobalt, iron and nickel at a predetermined weight ratio is put into a platinum crucible, which is placed in a vacuum furnace and heated to dissolve and mix the metal materials. The degree of vacuum in the furnace at this time was 4 × 1
Keep at 0 ^-6 Torr or more. As a result, even if a small amount of gas is generated in the alloy material, the gas escapes into the atmosphere without accumulating on the source surface and forming a film because the gas is in a vacuum atmosphere. If a sufficient effect (gas release) cannot be obtained by merely applying a vacuum, HIP processing (compression of the alloy material to expel internal gas) is performed as gas release processing of the molten metal. By doing so, the concentration of the gas contained in the completed deposition source (an ingot of a cobalt-iron-nickel alloy) can be reduced to 0.005% by weight or less.

In addition, it was confirmed that there was no fluctuation in the deposition rate of the deposition source in which the concentration of the contained gas was suppressed to 0.005% by weight or less.
0% by weight), the variation rate is 20-3.
0%.

[0012]

As described in detail above, the present invention, as a deposition source for forming a soft magnetic thin film by a vacuum deposition method, comprises a cobalt-iron-nickel alloy,
A gas having a gas concentration of 0.005% by weight or less is provided. By using the deposition source according to the present invention, a uniform cobalt-iron-nickel alloy thin film having no change in the deposition rate can be stably formed. Therefore, a magnetic head core suitable for high-density recording can be manufactured with high yield.

Claims (1)

[Claims] Claims: 1. An alloy comprising a cobalt-iron-nickel alloy,
A vapor deposition source for forming a soft magnetic thin film by a vacuum vapor deposition method, wherein the gas concentration is 0.005% by weight or less.