JPH0881771A - Film forming device and film forming method - Google Patents

Abstract

PURPOSE: To reduce the happening of defects, such as pinhole, decrease the number of exchanges of a deposition preventive plate and enable long-term continuous operation by suppressing peeling of deposited films. CONSTITUTION: A peeling preventive film is formed by sputtering of Al, etc., on the surface of the deposition preventive plate 11 arranged in a chamber 4. The peeling preventive film relieves the stress of the adhered film 12 formed by adhesion and deposition of metallic particles at the time of film formation on a substrate and prevents the peeling thereof. Continuous operation is made possible by further forming the peeling preventive film when the adhered film 12 is formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film forming apparatus and a film forming method for forming a metal thin film on a substrate of a magneto-optical recording medium by sputtering.

[0002]

2. Description of the Related Art A magneto-optical recording medium is a high-density recording medium which has recently attracted attention because it can be recorded and reproduced many times by erasing recorded information once. Further, in the magneto-optical recording medium, it is expected that the recording density will be further improved by further shortening the mark length per bit and further narrowing the pitch interval of the recording guide grooves.

Generally, a magneto-optical recording medium is an acrylic resin,
A high-vacuum magneto-optical recording film made of an alloy thin film of a transition metal such as iron and cobalt and a rare earth metal such as terbium, dysprosium, and cadolinium is formed on the surface of a substrate made of epoxy resin, polycarbonate resin, or other thermosetting resin, or glass. Film is formed in the state, and the surface is covered with an inorganic protective layer (Si
₃ N ₄ ) and an organic protective layer (UV curable resin) for protection. The sputtering method is suitable for forming the magneto-optical recording film and the inorganic protective layer because of the features that the film thickness and composition can be formed with good reproducibility and a film having good adhesion between the substrate and the thin film can be obtained.

FIG. 2 is a sectional view showing a conventional example of a film forming apparatus using such a sputtering method. This film forming apparatus 1
Is provided with a chamber 4 which is maintained at a high vacuum by a vacuum pump 2 and which has an introduction portion 3 for introducing a low pressure inert gas such as argon gas (Ar). Further, inside the chamber 4, a film forming material (for example, Tb ₂₂
A target 5 which is an Fe ₇₄ Co ₄ alloy) and a substrate 6 of a magneto-optical recording medium which is a substrate to be sputtered are respectively arranged and connected to a power supply 7 for sputtering. The substrate 6 is attached to a substrate holder 9 which is rotated by a motor 8 during film formation. When forming a film, the inside of the chamber 4 is evacuated by the vacuum pump 2 and the vacuum degree is 10 ⁻⁷ Tor.
While maintaining a high degree of vacuum of about r, a negative voltage is applied to the target 5 while introducing an inert gas into the chamber 4 from the introduction part 3. Then, the inert gas is electrically accelerated and collides with the surface of the target 5, whereby atoms or molecules on the surface of the target 5 are released and adhered and deposited on the surface of the substrate 6 to form a desired recording film 10. To be filmed. At this time, a part of the metal particles released from the target 5 forms an adhered film when adhered and deposited on the inner wall surface of the chamber 4. Therefore, in order to prevent this, the deposition preventive plate 11 is usually installed in the chamber 4.

In order to obtain high reliability as a magneto-optical recording medium, it is preferable that there are few defects such as pinholes. Therefore, the sputtering work is performed in a room with a cleanliness of 1000 or less. However, in the conventional method, the adhered film 12 adhered to the surface of the deposition preventive plate 11 may be separated during the sputtering and scattered in the chamber 4 to adhere to the substrate 6. If film formation is continued with the peeling pieces attached, defects such as pinholes will occur. Therefore, conventionally, the adhesion film 12 adhered and deposited on the adhesion preventing plate 11 is regularly or irregularly replaced with another adhesion preventing plate that has been cleaned before being peeled off. At the time of replacement, as a matter of course, the inside of the chamber 4 is returned to the atmospheric pressure and the deposition-preventing plate 11
Need to be replaced.

[0006]

As described above, in the conventional film-forming apparatus of this type, the deposition-prevention plate 11 is exchanged before the adhesion layer 12 deposited and deposited on the deposition-prevention plate 11 during film formation is peeled off. Was. However, the replacement of the deposition-inhibitory plate 11 is troublesome and time-consuming, and since the chamber 4 is returned to atmospheric pressure, continuous operation cannot be performed. There is also a problem in that a new attachment-preventing plate 11 for replacement must be prepared.

Therefore, the present invention has been made in view of the above-mentioned conventional problems, and an object thereof is to suppress the peeling of the adhered film, thereby reducing the occurrence of defects such as pinholes. Another object of the present invention is to provide a film forming apparatus and a film forming method that can reduce the number of times the deposition-prevention plate needs to be replaced and that enables continuous operation.

[0008]

In order to achieve the above object, the present invention according to claim 1 provides a target and a substrate in a chamber having a low-pressure inert gas inlet and having a high vacuum inside. In a film forming apparatus for arranging and depositing a metal thin film on the surface of a substrate by ion irradiation of a target, a deposition preventive plate that is disposed in the chamber and protects the inner wall of the chamber from metal particles is provided. The peeling prevention film is formed. In a second aspect of the present invention, the target and the substrate are arranged in a chamber having a low-pressure inert gas inlet and the inside of which is kept in a high vacuum, and a metal thin film is formed on the surface of the substrate by ion irradiation of the target. In the film forming method, the peeling prevention film is formed directly on the surface of the deposition preventing plate disposed in the chamber and protecting the inner wall of the chamber from metal particles, or when an adhesion film is formed on the deposition preventing plate surface. The peeling prevention film is formed on the film to form a film, and when the adhesion film is further formed on the peeling prevention film, a new peeling prevention film is further formed thereon to form the film. A third aspect of the invention is characterized in that, in the first aspect of the invention, the peeling prevention film is any one of Al, Cu, and Ti.

[0009]

In the present invention, the peeling prevention film alleviates the stress of the adhesion film formed by the adhesion and deposition of the metal particles, and prevents the adhesion film from peeling. Further, when the adhesion film is formed by the adhesion and deposition of the metal particles, the peeling prevention film is further formed on the adhesion prevention film to relieve the stress of the newly deposited adhesion film and to separate the adhesion film. To prevent. This allows
No need to replace the deposition shield.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the embodiments shown in the drawings. FIG. 1 is a sectional view of an essential part showing an embodiment of a film forming apparatus according to the present invention. According to the present invention, the peeling preventing film 20 is formed on the entire surface of the deposition preventing plate 11 arranged in the chamber 4 (see FIG. 1) to form a film.
The peeling prevention film 20 is formed by sputtering a metal of Al, Cu, or Ti. Further, during the film formation, a part of the metal particles of the target 5 adheres and deposits on the peeling prevention film 20 to form the adhesion film 12, so that the film thickness becomes a constant value or the target recording film 10 is formed. After forming several tens of lots, a new peeling prevention film 2 is formed on the adhesion film 12.
0'is formed and a film is formed. That is, in the present invention, the same anti-adhesion plate 11 is used any number of times by repeatedly forming the peeling prevention film 20. In this case, first, the peeling prevention film 2 is formed on the surface of the deposition preventive plate 11.
Adhesive film 1 formed by film formation without forming 0
When the thickness of 2 becomes a certain thickness, the peeling prevention film 2 is formed on top of it.
You may make it form 0.

When forming a film on the substrate 6, first, as shown in FIG.
With the inch glass 2P substrate 6 set, the inside of the chamber 4 is evacuated to a vacuum degree of about 10 ⁻⁷ Torr by the vacuum pump 2. While rotating the substrate holder 9, the inorganic protective layer (Si ₃ N ₄ ) and the recording layer (Tb ₂₂ Fe ₇₄ ) were formed on the substrate 6.
Co ₄ ), and an inorganic protective layer (Si ₃ N ₄ ) are formed by sputtering. As a result of sputtering this structure for 50 lots, the adhesion film 12 was formed on the surface of the deposition preventing plate 11. After that, the peeling prevention film 20 was formed on the adhesion film 12 formed on the surface of the deposition preventing plate 11 by sputtering Al without the substrate 6 being set. When the above operation was repeated, no peeling of the adhesion film 12 was observed at the time when the peeling of the adhesion film 12 from the deposition preventive plate 11 was observed in the conventional film forming method. I was able to confirm the effect. It is considered that this is because the peeling-and-adhesion-preventing film 20 absorbs and relaxes the stress of the adhesion film 12 to make it difficult for the adhesion film 12 to peel off.

The method of the present invention in which the peeling prevention film 20 is formed,
Discs of 200 lots were produced by the conventional method without forming the peeling prevention film, and the bit error rate in the entire area of the last 20 discs was measured. The following results were obtained. In the method of the present invention, the average bit error rate of 20 sheets is 7.0 × 10 ^−7.
The number of disks having an error rate of 1 × 10 ⁻⁶ or more was zero. On the other hand, in the conventional method, the average bit error rate of 20 sheets is 1.5 × 10 ^−6.
The number of disks having an error rate of 1 × 10 ⁻⁶ or more was 8. As is clear from this measurement result, according to the method of the present invention, the bit error rate can be reduced by simplifying the structure, and the defect of the disk due to the peeling of the adhered film can be effectively reduced and prevented. is there.

[0013]

As described above, in the film forming apparatus according to the present invention, the target and the substrate are placed in a chamber having a low-pressure inert gas introduction section and the inside of which is maintained in a high vacuum, and the target ion In a film forming apparatus for forming a metal thin film on the surface of a substrate by irradiation, a deposition preventive plate is provided in the chamber for protecting the inner wall of the chamber from metal particles,
Since the peeling-preventing film is formed on the surface of the adhesion-preventing plate, the peeling of the adhered film is small, and defects such as pinholes due to the peeling of the adhered film can be prevented. Furthermore, if the peeling prevention film is formed by sputtering, the inside of the chamber can be maintained in a vacuum, so that the number of times the anti-adhesion plate is replaced can be reduced and continuous operation for a long time is possible.

Further, in the film forming method according to the present invention, a new peeling prevention film is formed on the adhered film every time it is formed. The protective plate can be used any number of times.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of essential parts showing an embodiment of a film forming apparatus according to the present invention.

FIG. 2 is a schematic cross-sectional view showing a conventional example of a film forming apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Film-forming apparatus, 2 ... Vacuum pump, 3 ... Introductory part, 4 ... Chamber, 5 ... Target, 6 ... Substrate, 7 ... Power supply, 8 ... Motor, 9 ... Substrate holder, 10 recording film, 11 ... Adhesion prevention plate 1
2 ... Adhesive film, 20 ... Peeling prevention film.

Claims (3)

[Claims] 1. A film forming apparatus in which a target and a substrate are arranged in a chamber having a low-pressure inert gas introduction section and the inside of which is kept in a high vacuum, and a metal thin film is formed on the surface of the substrate by ion irradiation of the target. 2. A film forming apparatus, comprising: an adhesion preventing plate disposed inside the chamber for protecting an inner wall of the chamber from metal particles, and a peeling prevention film is formed on a surface of the adhesion preventing plate. 2. A film forming method in which a target and a substrate are placed in a chamber having a low-pressure inert gas inlet and a high vacuum inside, and a metal thin film is formed on the substrate surface by ion irradiation of the target. In the above, the peeling prevention film is formed directly on the surface of the deposition preventing plate which is disposed in the chamber and protects the chamber inner wall from metal particles, or when an adhesion film is formed on the surface of the deposition preventing plate. Is formed to form a film, and further, when an adhesion film is formed on the peeling prevention film, a new peeling prevention film is further formed thereon to form a film. 3. The film forming apparatus according to claim 1, wherein the peeling prevention film is any one of Al, Cu, and Ti.