JP2000100004A - Production of optical memory medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent deformation of a substrate even when a thin substrate is used and a film is formed by sputtering, and to efficiently produce an optical disk or the like. SOLUTION: In a first film forming device 1, a first dielectric layer 15, recording layer 16 and second dielectric layer 17 are successively formed by sputtering on a transparent resin substrate 14, and then the substrate is taken out into air and exposed to air for a specified time for cooling so as to remove damages added to the transparent resin substrate 14 by plasma during the first dielectric layer 15, recording layer 16 and second dielectric layer 17 are formed by sputtering. The transparent resin substrate 14 on which layers up to the second dielectric layer 17 are formed and cooled is sent to a second film forming device 2, where a reflection heat-radiating layer 18 is formed on the second dielectric layer 17. Thus, influences of damages due to plasma are reduced to decrease deformation of the transparent resin substrate 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an optical memory medium having a multilayer structure, such as an optical disk, and more particularly to a method for preventing deformation of the manufactured optical memory medium.

[0002]

2. Description of the Related Art For example, in the field of optical disks, it is necessary to reduce the spot diameter of a light source in order to enable high-density recording, and a lens having a high numerical aperture is used in an optical system. When a lens having such a high numerical aperture is used, the depth of focus of the lens becomes shallow, so that it is necessary to reduce the thickness of the substrate.
A substrate having a thickness of 6 mm, which is thinner than a conventionally used optical disk, is used.

[0003] Most rewritable optical disks using an inorganic material employ a sputtering method as a film forming method. The sputtering method generates plasma between the material to be formed and the substrate, and when the plasma particles collide with the target, strikes atoms from the target material,
This is a film forming method in which atoms react with activated oxygen gas or nitrogen gas to deposit respective oxides and nitrides on a substrate.

[0004]

In the sputtering method, the deposition temperature is low and a film can be easily formed. However, since plasma is used, there is considerable damage to the substrate by the plasma. In the case of DVDs, the same film formation method is used in most cases, but there is a disadvantage in that the substrate is greatly deformed due to plasma damage to the substrate during film formation because the substrate is thin.

[0005] The present invention has been made to solve the above-mentioned drawbacks, and prevents the substrate from being deformed even when the film is formed by a sputtering method using a thin substrate, thereby producing an optical memory medium capable of efficiently producing an optical disk or the like. It is intended to provide a method.

[0006]

According to a method of manufacturing an optical memory medium according to the present invention, a method of manufacturing an optical memory medium by forming a plurality of layers including a recording layer on a surface of a substrate by sputtering. After a part of the plurality of layers is formed, the film is cooled in the air, and then the remaining layers are formed.

When a part of the plurality of layers is formed and then cooled in the air, it is preferable that the layer exposed on the surface is not used as a recording layer.

Further, it is preferable to cool to a temperature of 40 ° C. or less when cooling in the air after forming a part of the plurality of layers. Furthermore, when cooling in the atmosphere after forming a part of the plurality of layers, it is desirable to blow dry gas to perform forced cooling.

Further, after a part of the plurality of layers is formed and then cooled in the atmosphere, when forming the remaining layers, the plurality of layers including the recording layer are formed on one substrate for one or a plurality of media. It is preferable to form a film by sputtering while the substrate is stationary.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An optical disk producing apparatus according to the present invention has a first film forming apparatus and a second film forming apparatus. The first film forming apparatus and the second film forming apparatus are independently provided at positions separated by a predetermined distance, and can respectively form three types of layers. When an optical disk is formed by laminating a first dielectric layer, a recording layer, a second dielectric layer, a reflective heat radiation layer, and a UV curable resin layer on a transparent resin substrate using the first film forming apparatus and the second film forming apparatus. Is a method in which a first dielectric layer, a recording layer, and a second dielectric layer are sequentially formed on a transparent resin substrate by a sputtering method in a first film forming apparatus, and then taken out into the air and exposed to the air for a predetermined time. After cooling, the first dielectric layer, the recording layer, and the second dielectric layer are formed by sputtering, so that the damage given to the transparent resin substrate by the plasma is removed. The transparent resin substrate on which the film up to the second dielectric layer has been formed and cooled is taken into a second film forming apparatus, and a reflective heat dissipation layer is formed on the surface of the second dielectric layer to reduce the influence of plasma damage. The amount of deformation of the transparent resin substrate is reduced by reducing the amount. The UV curable resin is applied to the surface of the reflective heat radiation layer of the transparent resin substrate in which the amount of the deformation is reduced to produce an optical disk.

[0011]

FIG. 1 is a block diagram of an optical disk producing apparatus according to an embodiment of the present invention. As shown in the figure, the optical disk producing apparatus has a first film forming apparatus 1 and a second film forming apparatus 2.
The first film forming apparatus 1 and the second film forming apparatus 2 are independently provided at positions separated by a predetermined distance. The first film forming apparatus 1 has a medium inlet 3, a first film forming chamber 4, a second film forming chamber 5, a third film forming chamber 6, and a medium outlet 7; Denotes a medium inlet 8, a fourth film forming chamber 9, a fifth film forming chamber 10, and a sixth film forming chamber 1.
1 and a medium outlet 12, and the first film forming apparatus 1 and the second
Can form three types of layers, respectively.

The first film forming apparatus 1 and the second film forming apparatus 2
As shown in the cross-sectional view of FIG. 2, the phase-change optical disk 13 formed by the above-described method includes a transparent resin substrate 14, a first dielectric layer 15, a recording layer 16, a second dielectric layer 17, a reflective heat radiation layer 18, and a UV.
It has a cured resin layer 19. The transparent resin substrate 14 is formed of polycarbonate or the like to have a diameter of 120 mm and a thickness of 0.6 mm, and has a guide groove for tracking on the surface. First
The dielectric layer 15 and the second dielectric layer 17 are formed of ZnS.SiO ₂ , the recording layer 16 is formed by stacking Ag-In-Sb-Te, and the reflective heat dissipation layer 18 is formed by sequentially stacking Al alloy. The UV curable resin layer 19 is formed by applying a UV curable resin to the reflective heat radiation layer 18 and curing the UV. First dielectric layer 15, recording layer 16, second dielectric layer 17, and reflective heat radiation layer 1
8 is formed by a high-frequency magnetron sputtering method.

The first dielectric layer 15, the recording layer 16, the second dielectric layer 17, and the reflective heat radiation layer 18 of the optical disk 13 configured as described above are used for the first film forming apparatus 1 and the second film forming apparatus. 2
The operation when forming a film will be described. First, the transparent resin substrate 14 is taken in from the medium inlet 3 of the first film forming apparatus 1 and is sent to the first film forming chamber 4, and the transparent resin substrate 14 is statically opposed to the target by the sputtering method. The first dielectric layer 15 is formed on the surface of the substrate. This first
The transparent resin substrate 14 on which the dielectric layer 15 is formed is sent to the second film forming chamber 5, and the recording layer 16 is formed on the surface of the first dielectric layer 15 by a sputtering method. This first dielectric layer 15
Then, the transparent resin substrate 14 on which the recording layer 16 is formed is sent to the third film forming chamber 6, and the second dielectric layer 17 is formed on the surface of the recording layer 16 by a sputtering method. Next, the transparent resin substrate 14 on which the first dielectric layer 15, the recording layer 16, and the second dielectric layer 17 are formed is taken out from the medium outlet 7 into the atmosphere, exposed to the air for a predetermined time, and naturally cooled. Second film forming apparatus 2
And taken into the fourth film forming chamber 9 through the medium inlet 8 of the second
A reflective heat dissipation layer 18 is formed on the surface of the dielectric layer 17. The transparent resin substrate 14 on which the reflective heat radiation layer 18 is formed is taken out from the medium outlet 12 and sent to the next step of applying a UV curable resin.
To form

The first film forming apparatus 1 and the second film forming apparatus 2
FIG. 3 shows the amount of deformation of the transparent resin substrate 14 after the first dielectric layer 15, the recording layer 16, the second dielectric layer 17, and the reflective heat dissipation layer 18 were formed on the transparent resin substrate 14 by sputtering. Shown in In FIG. 3, (A) shows a first film forming apparatus 1.
In the case where the second dielectric layer 17 is formed and the reflective heat radiation layer 18 is formed by the second film forming apparatus 2, (B) shows the reflection by one conventionally used film forming apparatus for comparison. The case where the layers up to the heat radiation layer 18 are formed is shown. As shown in FIG. 3, after forming the second dielectric layer 17 in the first film forming apparatus 1, exposing it to the atmosphere and allowing it to cool naturally, the second film forming apparatus 2 forms the reflective heat dissipation layer 18. When the film was formed, the amount of deformation of the transparent resin substrate 14 could be reduced to 50% or less than when the film was formed up to the reflective heat dissipation layer 18 by one film forming apparatus. That is, when the film is formed up to the reflective heat dissipation layer 18 by one film forming apparatus as in the related art, plasma damage is accumulated by sputtering in each successive film forming process, and the accumulation causes the deformation of the transparent resin substrate 14. The amount increases. On the other hand, the first film forming apparatus 1
When the second dielectric layer 17 is formed and then exposed to the air and cooled naturally, the history of damage caused by the plasma applied to the transparent resin substrate 14 can be eliminated, and the history of damage caused by the plasma is eliminated. By forming the reflective heat radiation layer 18 by the second film forming apparatus 2 in this state, the influence of plasma damage can be reduced, and the amount of deformation of the transparent resin substrate 14 can be reduced.

Therefore, the first dielectric layer 1 is
After the film 7 is formed, the transparent resin substrate 14 formed up to the second dielectric layer 17 before being taken into the reflective heat dissipation layer 18 by the second film forming apparatus 2 is exposed to the air and cooled for a variable time. The temperature of the transparent resin substrate 14 is set to about 25 ° C. and 30 ° C.
FIG. 4 shows the result of examining the amount of deformation of the transparent resin substrate 14 after cooling to the second temperature and cooling the film to the second film forming apparatus 2 to form the reflective heat dissipation layer 18. As shown in FIG. 4, the second dielectric layer 1
In the case where the transparent resin substrate 14 on which the film is formed up to 7 is exposed to the atmosphere and naturally cooled, and when cooled from 80 ° C. to 90 ° C.,
The amount of deformation of the transparent resin substrate 14 after the formation of the reflective heat dissipation layer 18 is large, and it is considered that the influence of plasma damage when the film is formed up to the second dielectric layer 17 remains. When cooled to about ℃, the reflective heat dissipation layer 18
The amount of deformation of the transparent resin substrate 14 after the formation of the second dielectric layer 17 can be greatly reduced, and the influence of plasma damage when the second dielectric layer 17 is formed can be reduced.

In the above embodiment, the first dielectric film 17 is formed in the first film forming apparatus 1 and before the second dielectric layer 17 is taken into the second film forming apparatus 2, the transparent film is formed up to the second dielectric layer 17. Although the case where the resin substrate 14 is exposed to the air and naturally cooled has been described, the transparent resin substrate 14 formed up to the second dielectric layer 17 may be forcibly cooled. For example, the transparent resin substrate 1 formed up to the second dielectric layer 17 and taken out of the first film forming apparatus 1
FIG. 5 shows the amount of deformation of the transparent resin substrate 14 after blowing dry air onto the substrate 4 to forcibly cool it to a temperature of 40 ° C. and then taking it into the second film forming apparatus 2 to form the reflective heat radiation layer 18. FIG.
3A shows a case where the transparent resin substrate 14 is forcibly cooled to 40 ° C., and FIG. 3B shows a case where the transparent resin substrate 14 is naturally cooled to 40 ° C. As shown in FIG. 5, when the transparent resin substrate 14 taken out of the first film forming apparatus 1 is forcibly cooled by blowing dry air, the transparent resin substrate on which the reflective heat radiation layer 18 is formed is the same as in the case of natural cooling. 14 can be greatly reduced. Also, the transparent resin substrate 14
When forced cooling is performed by blowing dry air on the optical disk 13, the cooling time can be shortened, and the time required to create the optical disk 13 can be significantly reduced, and the optical disk 13 can be efficiently created.

In the above embodiment, the first film forming apparatus 1 forms a film up to the second dielectric layer 17, and the second film forming apparatus 2 forms the reflective heat radiation layer 1.
8 was formed, the first dielectric layer 15 and the recording layer 16 were formed by the first film forming apparatus 1, and the second dielectric layer 17 was formed by the second film forming apparatus 2. The heat radiation layer 18 may be formed. As described above, the first dielectric layer 15 and the recording layer 16 are formed by the first film forming apparatus 1 and cooled to 40 ° C.
In the case where the second dielectric layer 17 and the reflective heat dissipation layer 18 are formed into the film, the amount of deformation of the transparent resin substrate 14 on which the reflective heat dissipation layer 18 is formed is determined by the first film formation apparatus 1. 2 The film is formed up to the dielectric layer 17.
Could be reduced in the same manner as in the case of forming a film.

Then, the second dielectric layer 1 is
7 and the reflective heat radiation layer 18 is formed by the second film forming apparatus 2, and the first dielectric layer 15 and the recording layer 16 are formed by the first film forming apparatus 1, The recording / reproducing characteristics when the second dielectric layer 17 and the reflective heat dissipation layer 18 were formed by the film forming apparatus 2 were examined. Here, recording is performed by condensing a laser beam having a wavelength λ = 635 nm with a lens having a numerical aperture of 0.6 and a linear velocity of 3.5 m / s.
The recording method uses a pulse modulation method, and the modulation method is E.
The measurement was performed by the FM + (8/16) modulation method. The recording linear density was 0.267 μm / bit, and the recording power under the optimum condition for the groove, ie, the concave and convex portions was used. Then, reproduction was performed using a laser beam having a wavelength of λ = 650 nm and a lens having a numerical aperture of 0.6, and jitter was measured and evaluated. As a result, a film is formed up to the second dielectric layer 17 by the first film forming apparatus 1,
When the reflective heat dissipation layer 18 is formed by the second film forming apparatus 2, the jitter σ / Tw (Tw; window width) is 8.6%, and the first dielectric layer 15 is formed by the first film forming apparatus 1. And recording layer 16
When the second dielectric layer 17 and the reflective heat dissipation layer 18 are formed by the second film forming apparatus 2, the jitter σ / Tw becomes 1
0.0%, and the first dielectric layer 15
A better signal is obtained when the second dielectric layer 17 is formed on the surface of the recording layer 16 and then cooled than when the recording layer 16 is formed and taken out and cooled with the recording layer 16 exposed. Could be obtained. That is, as rewritable optical disks using inorganic materials, there are a magneto-optical disk and a phase change optical disk.
Contaminated with water. Therefore, the second layer
It is better to form the dielectric layer 17 so that the surface of the recording layer 16 is not exposed to the atmosphere to prevent the surface of the recording layer 16 from being contaminated.

Further, in the above embodiment, the case where the film is formed by the RF magnetron sputtering in each of the film forming chambers of the first film forming apparatus 1 and the second film forming apparatus 2 has been described.
The film may be formed by sputtering or ion beam sputtering. For example, the amount of deformation of the transparent resin substrate 14 when the second dielectric layer 17 is formed by the first film forming apparatus 1 and the reflective heat dissipation layer 18 is formed by the second film forming apparatus 2 by ion beam sputtering is described below. As shown in FIG. 6A shows the case where the film is formed by ion beam sputtering, and FIG. 6B shows the case where the film is formed by RF magnetron sputtering. As shown in FIG. 6, the amount of deformation of the transparent resin substrate 14 could be reduced in almost the same manner, regardless of which of the sputtering methods was used.

In the above embodiment, one optical disk 13 is used.
The case where the first dielectric layer 15, the recording layer 16, the second dielectric layer 17, and the reflective heat dissipation layer 18 are formed on the transparent resin substrate 14 has been described. The recording layer 16, the second dielectric layer 17, and the reflective heat dissipation layer 18 may be formed on one transparent resin substrate 14. In this manner, the plurality of optical discs 13 are provided on one transparent resin substrate 14.
When the first dielectric layer 15 and the recording layer 16 are formed into a film, the transparent resin substrate 14 is formed by sputtering while the transparent resin substrate 14 is statically opposed to the target.
4 can be less damaged.

[0021]

As described above, according to the present invention, a plurality of layers are partially formed on the surface of a substrate, and then cooled in the atmosphere.
Deformation of the remaining layer after eliminating the history of damage caused by plasma applied to the substrate can reduce the amount of deformation of the optical memory medium thus produced.

Further, when a part of the plurality of layers is formed and then cooled in the air, the recording / reproducing characteristics of the formed optical memory medium are prevented from deteriorating by not using the layer exposed on the surface as a recording layer. Can be prevented.

Furthermore, when a part of the plurality of layers is formed and then cooled in the atmosphere to a temperature of 40 ° C. or less, the amount of deformation of the optical memory medium thus produced can be greatly reduced. Thus, a stable optical memory medium can be created.

Further, when a part of the plurality of layers is formed and then cooled in the atmosphere, a dry gas is sprayed to forcibly cool the optical memory medium, thereby reducing the amount of deformation of the manufactured optical memory medium and reducing the amount of deformation. Can be shortened, and an optical memory medium can be efficiently created.

Further, after a part of the plurality of layers is formed and then cooled in the air, when forming the remaining layers, the plurality of layers including the plurality of recording layers are transferred to one substrate. By forming a film by sputtering in a stationary state, damage to the substrate can be further reduced when the film is formed by a sputtering method with the substrate stationary facing a target.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an optical disk producing apparatus according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a configuration of an optical disc.

FIG. 3 is a distribution diagram of a deformation amount of a formed transparent resin substrate.

FIG. 4 is a distribution diagram of a deformation amount of a transparent resin substrate when a cooling temperature is changed.

FIG. 5 is a distribution diagram of a deformation amount of a transparent resin substrate when natural cooling and forced cooling are performed.

FIG. 6 is a distribution diagram of a deformation amount of a transparent resin substrate when films are formed by different sputtering methods.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st film-forming apparatus 2 2nd film-forming apparatus 3 Medium inlet 4 1st film-forming chamber 5 2nd film-forming chamber 6 3rd film-forming chamber 7 Medium outlet 8 Medium inlet 9 Fourth structure Film chamber 10 Fifth film forming chamber 11 Sixth film forming chamber 12 Medium outlet 13 Optical disk 14 Transparent resin substrate 15 First dielectric layer 16 Recording layer 17 Second dielectric layer 18 Reflecting heat radiation layer 19 UV curable resin layer

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Nobuaki Onagi 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company (72) Inventor Katsunari Hanaoka 1-3-6 Nakamagome, Ota-ku, Tokyo Share Inside Ricoh Company (72) Inventor Hiroko Tashiro 1-3-6 Nakamagome, Ota-ku, Tokyo Stock Company Inside Ricoh Company (72) Inventor Kiyoto Shibata 1-3-6 Nakamagome, Ota-ku, Tokyo Stock Company Ricoh Company (72) Inventor Yasumichi Aman 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company (72) Inventor Yuji Miura 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company (72) Inventor Wataru Otani 1-3-6 Nakamagome, Ota-ku, Tokyo F-term in Ricoh Co., Ltd. (Reference) 5D121 AA01 AA03 EE03 EE27 EE28 EE29 GG01

Claims (5)

[Claims] 1. A method for forming an optical memory medium by forming a plurality of layers including a recording layer on a surface of a substrate by sputtering, wherein a part of the plurality of layers is formed on the surface of the substrate and then cooled in the air. And then forming the remaining layer. 2. The method for manufacturing an optical memory medium according to claim 1, wherein a layer exposed on the surface when a part of the plurality of layers is formed and then cooled in the atmosphere is not a recording layer. 3. The method for manufacturing an optical memory medium according to claim 1, wherein when a part of the plurality of layers is formed and then cooled in the atmosphere, the temperature is cooled to a temperature of 40 ° C. or less. 4. The method for manufacturing an optical memory medium according to claim 1, wherein when cooling in the atmosphere after forming a part of said plurality of layers, forced drying is performed by blowing a dry gas. 5. An optical memory medium according to claim 1, wherein a plurality of layers including the recording layer is formed on one substrate for one or a plurality of media by sputtering while the substrate is stationary. Method.