JPH06162579A - Method and device for production of optical information recording medium - Google Patents

Abstract

PURPOSE:To improve durability for repeated reproducing of an optical information recording medium by improving chemical stability of a polymer compd. film as a base coating film. CONSTITUTION:A substrate with a substrate carrier bed 34 is housed in a first film forming room 12 which is evacuated to a vacuum to form a high-molecular compd. film by sputtering on the substrate. Then, the substrate with the substrate carrier bed 34 is housed in a polymer stabilizing room 13 where electric power is supplied to a UV lamp 22 and/or a heater 23 to irradiate the polymer compd. film already formed with UV rays at room temp. or in a heated state. By this method, reaction of unreacted component such as an active low mol.wt. component and free radicals included in the high-molecular compd. film is promoted to stabilize the high-molecular compd. film. Then, the substrate with the carrier bed 34 is housed in a second film forming room 14 where a recording film is formed by sputtering on the high-molecular compd. film.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for manufacturing an optical information recording medium, and more particularly to a method for stabilizing a polymer compound film vacuum-deposited on a substrate and a desired method on the substrate. The present invention relates to a vacuum film forming apparatus for thin films.

[0002]

2. Description of the Related Art Conventionally, a recording film carried on a substrate can be irradiated with a recording beam such as a laser beam to record, for example, video and audio, data of a computer and facsimile signals in real time. As an optical information recording medium, there is one in which a polymer compound film is formed on the substrate and the recording film is laminated on the polymer compound film.

An example of the polymer compound film is polytetrafluoroethylene. As the recording film, for example, in the case of a write-once type, a Te-Se alloy,
A low melting point alloy such as Te-Se-Pb is often used.
These films are generally formed, for example, by vacuum deposition, vapor deposition in gas,
The film is formed by a vacuum film forming method such as chemical vapor deposition, ion beam evaporation, electron beam evaporation, sputtering, reactive sputtering, ion beam sputtering, ion plating, and plasma polymerization.

By the way, the optical information recording medium is particularly required to have excellent long-term storability of information and excellent durability against repeated reproduction due to its properties. Conventionally, in the optical information recording medium having the above-mentioned structure, as a technique for improving the long-term storage stability of information, for example, Japanese Patent Publication No. 61-20
As described in Japanese Patent No. 932, after forming a recording film,
A thin oxide film (passive film) is generated on the surface of the recording film by subjecting the recording film to heat treatment or ultraviolet irradiation treatment,
A technique of improving the chemical stability of a recording film is known.

[0005]

However, the above technique is effective in improving the long-term storage stability of information, but is ineffective in durability against repeated reproduction. According to the research conducted by the inventors of the present application, a vacuum-deposited polymer compound film often contains active low-molecular weight components and free radicals. Components react with each other at the surface or inside of the polymer compound film, at the interface between the film and the substrate, or at the interface between the film and another film such as a recording film to generate a reaction product. It was found that the carrier-to-noise ratio (C / N) of the reproduced signal and the reproduced signal amplitude deteriorated or decreased with time as a result. Therefore, in order to increase the durability of the optical information recording medium against repeated reproduction, it is necessary to reduce or remove active low molecular weight components and free radicals existing in the vacuum-formed polymer compound film in advance. The present invention has been made based on such findings, and an object thereof is to provide an optical information recording medium having high durability against repeated reproduction.

[0006]

In order to achieve the above-mentioned object, the present invention relates to a method for manufacturing an optical information recording medium, including an optical information recording medium including a step of forming a polymer compound film on a substrate in vacuum. In the manufacturing method, the polymer compound film is vacuum-deposited on the substrate, and then a polymer stabilization treatment is carried out to accelerate the reaction of active unreacted components contained in the polymer compound film. It was

As the polymer stabilization treatment, a method of irradiating the polymer compound film with ultraviolet rays and accelerating the reaction of low molecular weight components or free radicals contained in the polymer compound film by its energy can also be used. Then
Alternatively, a method of irradiating the polymer compound film with ultraviolet rays while heating and promoting the reaction of low molecular weight components or free radicals contained in the polymer compound film by their energy can be adopted. In addition, as a procedure for performing the polymer stabilization treatment, it is possible to perform the polymer compound film on the substrate in a vacuum while simultaneously performing it.
It can also be performed after vacuum-forming the polymer compound film on the substrate and before forming the recording film on the polymer compound film. Further, it may be carried out after forming the polymer compound film on the substrate in vacuum and forming the recording film on the polymer compound film. It is more effective to directly irradiate the polymer compound film with the ultraviolet rays, but when the substrate is formed of a transparent body, it can be irradiated from the side of the substrate. When the polymer stabilization treatment is performed after the vacuum deposition of the polymer compound film, the polymer stabilization treatment can be performed in the vacuum film forming apparatus, or after taking out from the vacuum film forming apparatus, another polymer stabilization treatment can be performed. It can also be performed using a device.

The present invention has a disk shape, a card shape,
It can be applied to any form of optical information recording medium such as a tape. Therefore, as the substrate, a hard disk-shaped or card-shaped transparent substrate, a flexible tape-shaped base film, or the like can be used depending on the type of the desired optical information recording medium. As the base material, for example, an organic material such as an acrylic resin, a polystyrene resin, a polycarbonate resin, an epoxy resin, a polyamide resin, a polyimide resin, a polyethylene resin, or an inorganic material such as glass, or a composite material thereof can be used. .

Further, the present invention can be applied to optical information recording media of all known recording systems such as so-called hole forming type, pit forming type, bubble forming type, magneto-optical type and phase change type.
As a method for forming the polymer compound film and the recording film,
For example, vacuum deposition methods such as vacuum deposition, vapor deposition in gas, chemical vapor deposition, ion beam vapor deposition, electron beam vapor deposition, sputtering, reactive sputtering, ion beam sputtering, ion plating, and plasma polymerization are suitable.

On the other hand, regarding an apparatus for manufacturing an optical information recording medium, a polymer stabilizing treatment for promoting reaction of unreacted components contained in a polymer compound film formed in the film forming chamber is provided in the film forming chamber. It can be configured to incorporate the device,
A film forming chamber, which is separate from the film forming chamber, accommodates the substrate on which the polymer compound film is formed by the film forming chamber, and promotes reaction of unreacted components contained in the polymer compound film. It may be configured to include a molecular stabilization processing chamber. As the film forming chamber, it is possible to use various vacuum film forming apparatuses that execute the above-mentioned various vacuum film forming methods, and as the polymer stabilization processing device, an ultraviolet irradiation device or an ultraviolet irradiation device and a heating device are used. A combination with the device can be used.

[0011]

When the vacuum-formed polymer compound film is irradiated with ultraviolet rays, the reaction of active low molecular weight components and free radicals present in the film is promoted, and the chemical stability of the film is improved. For this reason, even if recording and reproduction are repeated, the polymer compound film is unlikely to deteriorate, and deterioration of the carrier-to-noise ratio (C / N) of the reproduction signal and decrease of the reproduction signal amplitude are suppressed. Therefore, durability against repeated reproduction of the optical information recording medium can be improved.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, prior to explaining the optical information recording medium manufacturing method according to the present invention, an example of a vacuum film forming apparatus applied to the manufacture of an optical information recording medium will be described.

FIG. 3 is a block diagram of a vacuum film forming apparatus according to the embodiment. As shown in FIG. 3, the vacuum film forming apparatus of this embodiment has a preliminary evacuation chamber 11 and a first film forming chamber 12. A polymer stabilization treatment chamber 13, a second film formation chamber 14, and a take-out chamber 1
5, the preliminary exhaust chamber 11 and the first film forming chamber 1 are provided.
2, the first film formation chamber 12 and the polymer stabilization treatment chamber 13, the polymer stabilization treatment chamber 13 and the second film formation chamber 14, the second film formation chamber 14 and the take-out chamber 15 respectively buffers 16-19. Are connected through.

A vacuum pump 20 is connected to each of the preliminary evacuation chamber 11, the first film forming chamber 12, and the second film forming chamber 14 so that the degree of vacuum in each chamber 11, 12, 14 can be adjusted appropriately. It is like this. In addition, the first film forming chamber 12
A sputtering gas source 21 is connected to each of the second film forming chamber 14 and the second film forming chamber 14 so that the sputtering gas pressure in each chamber 12, 14 can be adjusted appropriately. Further, in each of the film forming chambers 12 and 14, devices necessary for sputtering film formation such as targets 12a and 14a and counter electrodes 12b and 14b are installed. On the other hand, the polymer stabilization processing chamber 13
Inside, an ultraviolet lamp 22 and a heating device 23 are installed.

Gate valves 24 to 33 are provided at the carry-in entrance and the carry-out exit of each of the chambers 11 to 15 to ensure airtightness in the room. Further, in the preliminary exhaust chamber 11,
Before the start of film formation, a substrate transfer table 34 is installed which can be transferred to the subsequent chambers 12 to 15 via the gate valves 25 to 33 and the buffers 16 to 19.

Hereinafter, a method of using the vacuum film forming apparatus having the above structure will be described. First, the vacuum pump 20
Is driven to evacuate the first film forming chamber 12 and the second film forming chamber 14 to a predetermined degree of vacuum, and then the pre-evacuation chamber 11 is internally provided with a substrate serving as an optical information recording medium. It is attached to the carrier 34 and the preliminary exhaust chamber 11 is evacuated to a predetermined vacuum degree.

After the evacuation is completed, the gate valves 26 and 27
Is opened and closed to store the substrate in the first film forming chamber 12 together with the substrate transfer table 34. Here, while the vacuum pump 20 is being driven, the amount of sputter gas introduced from the sputter gas source 21 into the first film forming chamber 12 is adjusted, and when the sputter gas pressure in the chamber reaches a predetermined pressure and a steady state, Counter electrode 12b
Is energized to deposit sputtered particles from the polymer target 12a on the substrate until a predetermined film thickness is obtained.

After the first film formation is completed, the gate valves 28 and 29 are opened and closed to store the substrate in the polymer stabilization processing chamber 13 together with the substrate transfer table 34. Here, the ultraviolet lamp 22 and / or the heating device 23 is energized to irradiate the previously formed polymer compound film with ultraviolet light at room temperature or in a heated state. This promotes the reaction of active low molecular weight components and unreacted components such as free radicals contained in the polymer compound film, and stabilizes the polymer compound film.

After the stabilization process of the polymer compound film is completed, the gate valves 30 and 31 are opened and closed to store the substrate in the second film forming chamber 14 together with the substrate transfer table 34. Here, while the vacuum pump 20 is being driven, the amount of sputter gas introduced from the sputter gas source 21 into the second film forming chamber 14 is adjusted, and when the sputter gas pressure in the chamber becomes a predetermined pressure and a steady state, The counter electrode 14b is energized to deposit the sputtered particles from the recording film target 14a on the substrate until the film has a predetermined thickness.

After the recording film is formed, the gate valve 32 is opened and closed to temporarily store the substrate in the take-out chamber 15 together with the substrate transfer table 34, and finally the gate valve 33 is opened and closed to produce an optical information recording medium as a product. Is taken out from the take-out chamber 15.

Next, an example of a method of manufacturing the optical information recording medium according to the present invention will be described with reference to FIG. FIG. 1 is an enlarged cross-sectional view of an essential part of an optical information recording medium according to an embodiment, in which a base film 3 is formed on a preformat pattern forming surface 2 of a transparent substrate 1.
Is deposited, and the recording film 4 is laminated on the base film 3.

In manufacturing this optical information recording medium, first, a polycarbonate substrate 1 having a desired preformat pattern 2 and having a diameter of 5.25 inches is molded on one surface by injection molding. The shape of the substrate 1, the manufacturing procedure, the molding apparatus, and the preformat pattern 2
The configuration and arrangement of the above are matters that are publicly known and are not the gist of the present invention, and thus the description thereof will be omitted.

Next, the produced polycarbonate substrate 1
Are sequentially stored from the preliminary exhaust chamber 11 of the vacuum film forming apparatus to the first film forming chamber 12, and the preformat pattern forming surface 2 of the polycarbonate substrate 1 is stored in the first film forming chamber 12.
In addition, about 400 of polytetrafluoroethylene base film 3
Sputtering was performed to a film thickness of (Å). The film forming conditions of the base film 3 are as follows: target is polytetrafluoroethylene, sputter gas is argon, and sputter gas pressure is 4 × 10 to
^The applied voltage was ³ (mbar) and the applied voltage was high frequency 450 (W).

Next, the polycarbonate substrate 1 on which the polytetrafluoroethylene undercoating film 3 is formed is transferred into the polymer stabilization treatment chamber 13, and the strength is 30 (mW / cm ²⁾ from the undercoating film 3 side at room temperature. 30) for 30 minutes.

Further, the polycarbonate substrate 1 which has been subjected to the ultraviolet irradiation treatment is transferred into the second film forming chamber 14 and Pb-Te-Se is formed on the polytetrafluoroethylene base film 3.
The recording film 4 of No. 1 was sputtered to a film thickness of about 210 (Å) to manufacture the optical disk shown in FIG. The conditions for forming the recording film 4 are as follows: the target is Pb-Te-Se alloy, the sputter gas is argon, and the sputter gas pressure is 5 × 10 ³ (mba).
r) and the applied voltage was high frequency 370 (W).

FIG. 2 shows the durability test results for the repeated reproduction of the optical disc according to the above-mentioned example, together with the optical disc according to the comparative example. In this graph, the horizontal axis represents the test time, and the vertical axis represents the C / N ratio of the reproduced signal. The data of the example product is indicated by a circle and the data of the comparative example is indicated by a triangle. ing. In the optical disk according to the comparative example, after the polytetrafluoroethylene base film 3 was sputtered on the preformat pattern forming surface 2 of the polycarbonate substrate 1, the base film 3 was immediately exposed to Pb-Te-Se without being subjected to ultraviolet irradiation treatment. The recording film 4 is formed by sputtering, and the other parts are configured similarly to the optical disc according to the embodiment.

The test conditions are as follows. That is, while the optical discs of Examples and Comparative Examples were rotationally driven at a rotational speed of 1000 rpm, a semiconductor laser beam kept at a power level at which recording was not performed by the optical head was irradiated to preformat the optical discs. The optical head was driven so that the tracking groove and the center of the light spot were always aligned. At the same time, automatic focusing was performed so that the laser beam focused on the Pb-Te-Se recording film. After that, the power of the semiconductor laser beam is switched to the recording level of 6.7 (mW), and Pb
An 8T signal was recorded on the -Te-Se recording film. Next, the power of the semiconductor laser beam was switched to a reproduction level at which recording was not performed again, and the change in the C / N ratio of the reproduction signal from immediately after recording until 3000 hours elapsed was measured.

As is apparent from FIG. 2, the comparative example product is 10
When the reproducing operation for the same track is continuously repeated (for a minute), the C / N ratio of the reproduced signal is lowered by about 2 (dB), whereas the example products are almost C / N ratio under the same condition.
The N ratio does not deteriorate. In addition, the comparative example product is about 200 (minutes)
While the C / N ratio of the reproduced signal decreases by about 2.7 (dB) with the lapse of time, the example product stops at about 0.5 (dB). As described above, the product of this example has high durability against repeated reproduction.

In the above-mentioned embodiment, the ultraviolet rays are irradiated at room temperature, but if the ultraviolet rays are irradiated while heating, the same effect can be obtained in a shorter treatment time. Further, in the above-mentioned Examples, the polymer compound film was directly irradiated with ultraviolet rays, but when the substrate is formed of a transparent body, it can be irradiated from the side of the substrate.

[0030]

As described above, according to the present invention,
After vacuum-forming a polymer compound film on a substrate, the polymer compound film is irradiated with ultraviolet rays at room temperature or under heating to accelerate the reaction of active low molecular weight components and free radicals present in the film. Since the chemical stability of the film is improved, the polymer compound film is less likely to deteriorate even after repeated recording and reproduction, and the carrier-to-noise ratio (C / N) of the reproduced signal is deteriorated and the reproduced signal amplitude is decreased. Is suppressed, and durability against repeated reproduction of the optical information recording medium is improved.

[Brief description of drawings]

FIG. 1 is an enlarged cross-sectional view of a main part of an optical information recording medium according to an example.

FIG. 2 is a graph showing a result of a durability test against repeated reproduction.

FIG. 3 is a configuration diagram of a vacuum film forming apparatus according to an embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Preformat pattern 3 Underlayer film 4 Recording film 11 Preliminary exhaust chamber 12 First film forming chamber 13 Polymer stabilization treatment chamber 14 Second film forming chamber 15 Extraction chamber 16-19 Buffer 20 Vacuum pump 21 Sputtering gas source 22 Ultraviolet lamp 23 Heating device 24 to 33 Gate valve 34 Substrate carrier

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Naoyuki Kikuchi 1-88, Torora, Ibaraki City, Osaka Prefecture Hitachi Maxell Co., Ltd. (72) Inventor Takayuki Goto 1-88, Torora, Ibaraki City, Osaka Prefecture Hitachi Within Maxell Co., Ltd. (72) Inventor Masafumi Yoshifumi 1-88, Tora-Tora, Ibaraki-shi, Osaka Hitachi Maxell Co., Ltd. (72) Inventor Norio Ohta 1-88 Tora-Tora, Ibaraki-shi, Osaka Hitachi Maxell Within the corporation

Claims (8)

[Claims] 1. A method for manufacturing an optical information recording medium, comprising the step of vacuum-depositing a polymer compound film on a substrate, wherein the polymer compound film is vacuum-deposited on the substrate, and then the polymer compound film is formed. A method for producing an optical information recording medium, which comprises subjecting a polymer stabilizing treatment for accelerating a reaction of unreacted components contained therein. 2. The polymer stabilization treatment according to claim 1, wherein the polymer compound film is irradiated with ultraviolet rays, and the energy of the polymer compound reaction causes a reaction of a low molecular weight component or a free radical contained in the polymer compound film. A method of manufacturing an optical information recording medium, characterized in that the process is a accelerating process. 3. The polymer stabilization treatment according to claim 1, wherein the polymer compound film is irradiated with ultraviolet rays while being heated,
A method for producing an optical information recording medium, which is a process for promoting the reaction of a low molecular weight component or a free radical contained in the polymer compound film by the energy thereof. 4. The manufacturing of an optical information recording medium according to claim 2, wherein the ultraviolet irradiation is performed simultaneously with vacuum formation of the polymer compound film on the substrate. Method. 5. The method according to claim 2 or 3, wherein the ultraviolet irradiation is performed after vacuum-depositing the polymer compound film on the substrate and before forming a recording film on the polymer compound film. A method for manufacturing an optical information recording medium, which is performed from at least one of a substrate side and a polymer compound film side. 6. The ultraviolet irradiation according to claim 2, wherein the polymer compound film is vacuum-deposited on the substrate,
And after forming a recording film on the polymer compound film,
A method for manufacturing an optical information recording medium, which is performed from the side of the substrate. 7. A polymer stabilizing treatment device for accelerating the reaction of unreacted components contained in the polymer compound film formed by the film forming chamber is incorporated in the film forming chamber. Optical information recording medium manufacturing apparatus. 8. A polymer stabilization that accommodates a film forming chamber and a substrate on which a polymer compound film is formed by the film forming chamber, and promotes reaction of unreacted components contained in the polymer compound film. An apparatus for manufacturing an optical information recording medium, comprising: a processing chamber.