JPS60170915A - Formation of magnetic thin film - Google Patents

Abstract

PURPOSE:To obtain magnetic thin film which shows less deterioration in oxidation by providing a mask of predetermined shape on a substrate and then depositing it by alternately operating rotatable permanent magnet and shutter on the occasion of laminating and depositing a metal thin film which is easily oxidized and a film for preventing oxidation on the substrate. CONSTITUTION:A couple of electrodes 1 surrounded by a shield plate 2 at the side surfaces are arranged wihin a vacuum casing and an SmCo5 target material 3 and Al target material 4 are attached respectively to these electrode surfaces. At the position opposing to the targets material 3, a glass substrate 8 placed on the substrate pedestal 6 and a mask 7 consisting of magnetic material of the predetermined shape is provided. The target 3 is vaporized while the target 3 is covered with the shutter 5, SmCo5 is adhered to the exposed surface of substrate 8, a rotating body 9 is rotated and the mask 7 is attracted and removed by a permanent magnet 10 provided to said rotating body. Thereafter, the shutter 5 is shifted to the side of target 3, the Al target 4 is vaporised and Al film is deposited on the SmCo5 film.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for forming a magnetic thin film using a vacuum system in which a metal film that is easily oxidized is covered with an oxidation-preventing coating. It is.

[Prior art and its problems]

Among magnetic films made of a combination of rare earth metals and iron group metals, GdCo and GdFe are used as recording materials that utilize magnetic elements and orientation perpendicular to the film surface, as well as Sm-Co and Ce-C.
Much research is underway on O as a material for downsizing step motors that utilizes its high energy product and high coercive force.

One of the problems when putting films made of these materials into practical use is that their properties deteriorate due to oxidation.

In particular, rare earth elements are easily oxidized, so conventionally a method has been used to deposit an oxidizing substance or a metal film such as ^l on the surface of these films to prevent oxidation.

On the other hand, a method using a vacuum system is generally used to produce a magnetic film, and sputtering methods and vacuum evaporation methods are used. As a method for attaching a protective film using such a method, there is a method in which a magnetic film is attached to a predetermined position without opening the vacuum system, and then a protective film is attached thereon. A mask is used to attach the magnetic film to a predetermined position, but if a mask is used and the protective film is attached as it is, the protective film will not adhere to the surface of the magnetic film that will be in the shadow of the mask, leading to oxidation problems. Sign. For this reason, a problem has arisen in that the surface treatment must be performed again, or the protective film must not be applied in a vacuum system, and even if characteristics deteriorate due to oxidation, it must be taken out from the vacuum system and processed. To solve this problem, it is necessary to attach a protective film after depositing the magnetic film and separating the mask from the substrate surface so as not to damage the magnetic film.

[Purpose of the invention]

An object of the present invention is to provide a method for forming a magnetic thin film with little oxidative deterioration after taking such measures.

[Structure of the invention]

The present invention comprises a mask made of a magnetic material or a shape memory alloy,
After forming the first film on the substrate, the mask is removed using a magnet or heating, and then a second film for preventing oxidation is deposited.

〔Example〕

Hereinafter, the present invention will be specifically explained based on Examples.

Example 1 FIG. 1 is a schematic diagram showing the structure near the electrode part of the spackle device, in which a SmCo5 target shrine (3
) and a surface coating material Al target material (4) are fixed. Shield the electrode material (
2) is placed. The shutter (5) and the substrate stand (6) are fixed to one rotating body, and a glass substrate (8) and a mask (7) made of a magnetic material are placed on the substrate stand (6). Further, a ferrite magnet 00) for removing this mask (7) is fixed to the rotating body (9).

First, after arranging each part in the state shown in Figure 1, the inside of the vacuum chamber was evacuated to 3 x 10" Torr, argon gas was introduced at 0.4 Torr, and after stabilization, -1,5 Torr was applied to electrode +11.
KV was applied. After sputtering for about 10 hours to form a SmCo5 film, the rotating body (9) is turned and the ferrite magnet 00
) onto the substrate, the mask (7) is attracted to the ferrite magnet α0) and moves away from the substrate (8), so
In this state, when the rotating body (9) was turned and the discharge of the target (3) was stopped using the shutter (5), the AI target (4) was sputtered at the same time, and a coating was formed on the SmCo5 film. Since the mask (7) has been removed, the SmC
The entire surface of the o5 membrane was coated. In this embodiment, a ferrite magnet was used for mask removal, but it is clear that the same effect can be achieved even if an electromagnet is used. Alternatively, a mask made of a non-magnetic material may be used, a magnetic material may be connected to the mask, and the magnetic material may be moved using a permanent magnet or the like.

Example 2 FIG. 2 is a schematic diagram showing the structure near the electrode part of the spuck device.
A shield plate (2) is placed so that the target material (4) and the electrode (1) are not spattered. Shutter (5), board stand (6) and board (
8) is fixed to the same rotating body (12), and the substrate (8) is fixed to the same rotating body (12).
) is placed on a mask (7) connected to the shape memory alloy (13), and a heater (14) is provided near the shape memory alloy (13). First, after placing each part in the state shown in Figure 2, the inside of the vacuum chamber is 3 x 1O-6
Evacuate to Torr, introduce argon gas to 0.2 Torr, and after stabilizing, apply -1.5 KV to the electrode (11).
The Gd-Go target (11) is spun to form a film on the substrate (8). After sputtering for 4 hours, sputtering was stopped and the heater (14) was heated, and the shape memory alloy NiTi was deformed and changed into the shape shown by the broken line. Mask (7)
) has separated from the substrate (8), rotate the rotating body (12), apply -1, OKV to the electrode +11 again, and set ^l to Gd.
The entire surface of the -Co film was uniformly coated.

In this embodiment, the mask material and the material for moving the mask are different, but it is clear that the mask material itself may also be made of a shape memory alloy.

In addition, although the above-mentioned examples were all shown using a method using a sputtering method, similar results could be obtained using other film forming methods using a vacuum system, such as CVD method, vacuum evaporation method, or ion blating method. is obtained.

〔Effect of the invention〕

As described above, according to the present invention, the protective film can be attached to the entire surface of the first film without opening the vacuum system or damaging the film.

[Brief explanation of drawings]

FIGS. 1 and 2 are schematic diagrams showing the structure inside a vacuum chamber of a sputtering apparatus used in an embodiment of the present invention, respectively. (1): Electrode (2): Shield plate (31, f41. (11): Target (5): Shutter (6): Substrate stand (7): Mask (8) Two substrates

Claims (1)

[Scope of Claims] 1. After forming a first film in a vacuum container on a portion of the substrate that is not obstructed by a mask that can be attracted by magnetic force, 2. A method for forming a magnetic thin film, which comprises removing the mask using a magnet, and then depositing a second film as a protective film on the first film. 2. The method for forming magnetic ins according to claim 1, wherein the first film is made of a material consisting of a combination of a rare earth metal and an iron group metal, and the 211N is an oxidation-resistant material. 3. The method of forming a magnetic thin film according to claim 1, wherein the second film is made of a material made of a combination of Y and an iron group metal, and the second film is a monoxide material. 4. In a vacuum container, after placing a mask entirely or partially made of a shape memory alloy on a substrate, a first film is formed on the portions not covered by the mask, and then,
A method for forming a magnetic thin film, comprising moving a mask by activating a shape memory alloy, and depositing a second film as a protective film on the first crotch. 5. The method of forming a magnetic thin film according to claim 4, wherein the first film is made of a material made of a combination of a rare earth metal and an iron group metal, and the second film is made of an oxidation-resistant material. 6. The method of forming a magnetic thin film according to claim 4, wherein the second film is made of a material made of a combination of Y and an iron group metal, and the second film is made of an oxidation-resistant material.