JPS60202543A - Production of magnetic recording medium - Google Patents

Abstract

PURPOSE:To produce a magnetic recording medium at a high speed with a magnetron sputtering process by using a target where ferromagnetic materials and other materials are arrayed flatly and alternately. CONSTITUTION:A ferromagnetic thin film is formed on a supporter with a magnetron sputtering process which makes use of the glow discharge that catches scattered secondary electrons by a line of magnetic force. In this case, a target is used. This target is obtained by arraying ferromagnetic materials 10 and other materials 11 of flat plate types alternately on a target holder 9. Thus the magnetic fields which catch the secondary electrons produced by a magnet group 12 are not affected by the materials 11 at all. This increases the effective magnetic fluxes. In such constitution, the sputtering fields are studied for both materials 10 and 11. Then the smaller conditions are selected for the materials 11 to increase the area occupied by the materials 11. As a result, the effective magnetic flux is increased further.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method of manufacturing a magnetic recording medium using a ferromagnetic thin film as a magnetic recording layer.

Conventional configurations and their problems Magnetic recording media used for video recording, computer data recording, etc. have increased recording capacity.

In order to achieve miniaturization of equipment, there is a strong desire to improve recording density, and magnetic recording such as magnetic tapes and magnetic disks in which the magnetic recording layer is a ferromagnetic metal thin film, ferromagnetic oxide thin film, etc. on a support. Media development is progressing.

The ferromagnetic thin film is formed using electron beam evaporation.

Examples include ion blating methods, sputtering methods, electroless plating methods, etc., but in recent years they have attracted attention as methods that will further improve recording density because the shorter the wavelength, the smaller the self-demagnetization loss. The CO-Or alloy thin film is
A perpendicular magnetization film that is used by being magnetized perpendicular to the support surface.
It is said that the better the crystal orientation, the more suitable it is for high-density digital recording, and it has been confirmed that sputtering is suitable for obtaining such thin films.

However, the drawback of the sputtering method is that the film formation rate is slow, and in particular, the so-called high-speed magnetron solar cell, which uses a type of glow discharge that captures secondary electrons scattered by magnetic field lines (because the sputtering method cannot be used effectively, (The creeping speed is 1/100 of that of paramagnetic materials such as CU, for example.
The following improvements are desired.

FIG. 1 is a diagram showing the main parts of a magnetic recording medium manufactured using a magnetron. A ferromagnetic thin film having predetermined magnetic properties and film thickness is applied while moving to the target.The sputter evaporation source is schematically shown, but due to the generation of magnetic lines of force under the target 6, which is made of vine wood, magnet 6 is arranged, and the lines of magnetic force 7 are directed from the N pole to the S pole in the figure. However, if the target 6 is made of a ferromagnetic material, the lines of magnetic force 7 are directed by the target 6.
When the electrons are blown away, the magnetic field lines that leak out and serve to capture the scattered secondary electrons (those emitted by the target) are greatly reduced.

Therefore, if the glow discharge sound is made stronger to increase the speed, the secondary electrons will not be captured and will be directed towards the support, causing thermal damage to the support.If polyethylene terephthalate is used as the support, it will melt immediately and the magnetic recording medium will On the other hand, when manufacturing without thermal damage, glow discharge cannot be strong, so for example, CO
-ar (Or18% by weight)'io, 1 μm direction arrow - If the length of the target is 12.5 (m), the moving speed of the support will be extremely slow, about Q, 3 m/min. Reference numeral 8 designates a cooling plate for the magnet 6, which functions to hold the magnet 6 and serve as a magnetic path.

Incidentally, the application of an electric field, the introduction of a discharge gas, etc. for generating glow discharge are used within a known range.

Currently, in order to strengthen the glow discharge and speed it up, it is necessary to use a highly heat-resistant and expensive film such as polyimide as the support, and even if such a film is used,
The limit was to increase the movement speed to m/l1lifl.

OBJECTS OF THE INVENTION An object of the present invention is to provide a method for manufacturing magnetic recording media that can produce magnetic recording media at high speed by sputtering.

Structure of the Invention The present invention uses a ferromagnetic material (B) and a non-ferromagnetic material (B) when forming a ferromagnetic thin film on a support by magnetron sputtering using a glow discharge that captures secondary electrons scattered by an output line. This method of manufacturing a magnetic recording medium is characterized by using a target in which targets are alternately arranged in a plane.

In this embodiment, a target is used in which a flat non-ferromagnetic material B is arranged on the side closer to the source of the magnetic lines of force, and a plurality of ferromagnetic linear materials are arranged with gaps on the far side. This is a method for manufacturing a magnetic recording medium. The method of manufacturing a magnetic recording medium is further characterized in that the plurality of ferromagnetic linear materials are energized to perform sputtering in a state where a magnetic field is applied. This makes it possible to manufacture

DESCRIPTION OF EMBODIMENTS An embodiment will be described below with reference to the drawings. There are some features of the target that need to be improved, so I will explain those parts in detail. FIG. 2 shows an example of a target structure for two-well sputtering using a flat plate-shaped ferromagnetic material on a target holder 9, which is used for the malleability of the present invention. It is made by adhesively arranging it.

The secondary electron capturing magnetic field generated by the magnet group 12 is generated by the material B.
11 is not affected at all, so the effective magnetic flux increases.

With this configuration, the effective magnetic flux can be further increased by examining the sputter yield for material B and selecting a condition where the sputter yield for material B is smaller, and by increasing the area ratio occupied by material B. It is. 13
is a cooling plate.

Figure 3 shows a ferromagnetic material M1o and a non-ferromagnetic material B.
Reference numeral 11 is an example in which the material is made of a linear material, which is characterized in that the leakage magnetic field can be made larger than in the flat material arrangement shown in FIG. This effectively works to speed up sputtering.

FIG. 4 shows the ferromagnetic material 11 as a linear material.

This is an example in which the target is arranged away from the flat non-ferromagnetic material B10 and closer to the substrate 2 side, where 14 is a schematic representation of sputtered atoms of a non-ferromagnetic material, and 16 is a schematic representation of sputtered atoms of a ferromagnetic material. 16 is a model showing the state of thin film deposition.

The target in FIG.
For example, by configuring the wire to generate a magnetic field around the wire by passing a direct current, even higher speed sputtering becomes possible. In either target configuration, the leakage magnetic field can be made 2 to 26 times larger than when using a conventional all-ferromagnetic alloy target because the target is effectively non-magnetic. This is because it can effectively capture secondary electrons scattered towards the body.

The glow discharge can be made much stronger, and therefore a ferromagnetic thin film can be formed on the support by a high speed sputtering method. Further, specific examples will be explained in detail.

A perpendicularly magnetized film was formed on a polymer substrate using an apparatus similar to that shown in FIG. The top surface of the target holder (copper plate thickness: 5 mm) was placed at a position of 12 cIrL directly below a cylindrical can with a diameter of 50 m (50 m). An alnico magnet with a maximum magnetic flux density of 2600 (Gauss) on the opposite side was used.

The target is cobalt (with a longitudinal length of 3 cFrL).
Thickness 1. emm) and sintered chromium (length 1cm, 1
A system in which 3 microorganisms (2 cm in diameter) were arranged as shown in FIG. 2 so that there were 12 bacteria in total length was designated as system (1).

Also, as shown in Figure 3, a Co wire with a diameter of 2111 m and a diameter of 21 m
IIIl W@ was placed. A target in which two W wires and two Co wires were alternately arranged in groups of six and fixed with adhesive in the longitudinal direction was used as a system.

As shown in Figure 4, 1.
2 (m apart, Co@(diameter 2 mm) center distance 4.
The case where 27 wires are insulated with 6mm and 1 is not energized is the system - [1
], and the case where a current of 12 μm was passed was defined as system (IV).

[Example-1] After exhausting to 7X10 TOrr in advance.

System [1] using polyethylene terephthalate 9.5 μm
] to [■] were used to form a perpendicularly magnetized film of 0.1 .mu.II as shown in Table 1.

(Hereinafter referred to as Shimokin White) here.

(1) The high frequency is 13.56 MtlZ.

(2) Δθ5o is the half width of the rocking curve in X-ray diffraction, and the smaller this value, the better the orientation.

[Example 2] A perpendicular magnetization film with a thickness of 0.1 μm was formed on 26 μm of polyimide. This is shown in Table 2.

(Hereinafter referred to as gold and white) According to the farming method of the present invention in any of the examples, c.

- It is possible to perform sputtering at a speed three to four times faster than the conventional method using CR, CO-'RL, and CO-W alloy targets, and is suitable for mass production of magnetic disks.

Effects of the Invention As described above, the present invention has a configuration that can increase the leakage magnetic flux to the front surface of the target.

By generating a magnetic field in a part of the target and using a high-speed sputtering method to form a perpendicularly magnetized film with good C-axis orientation, this method can achieve productivity three to four times higher than conventional methods, and its practical effects are significant.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of the main parts of an apparatus used to continuously form a ferromagnetic thin film on a substrate by sputtering. FIGS. 2 to 4 are diagrams showing the configuration of the main parts of a sputtering target according to the present invention. 2... Board, e... river/target holder,
10...Ferromagnetic material, 11... Strong Al
Other materials added to the magnetic material, 12... Magnet 7 Figure 1 □ □ □ Second section 12 r'J

Claims (3)

[Claims] (1) When forming a ferromagnetic thin film on a support by magnetron sputtering, which uses glow discharge to capture scattered secondary electrons using lines of magnetic force, ferromagnetic and non-ferromagnetic materials are alternately layered in a plane. A method of manufacturing a magnetic recording medium, characterized by using an array of targets. (2) A target rattle is used in which a plurality of linear ferromagnetic materials are arranged with a gap between a plate-shaped non-ferromagnetic material on the side closer to the source of the magnetic field lines and a gap on the far side. A method for manufacturing a magnetic recording medium according to item 1. (3) Claim 2, characterized in that a plurality of linear ferromagnetic materials are energized, thereby generating a magnetic field.
A method for manufacturing a magnetic recording medium as described in .