JP2002074770A - Information recording medium manufacturing method, substrate holder structure, and film forming apparatus - Google Patents

Abstract

(57) Abstract: A method of manufacturing an information recording medium, a substrate holder structure, and a film forming apparatus, which can suppress an increase in the temperature of a substrate during film formation by sputtering and can manufacture an information recording medium with less warpage and distortion. To do. SOLUTION: In mounting a substrate 1 on a holder 2 made of a metal or an alloy having a holding surface 2A for holding the substrate 1 and performing sputtering, the substrate 1 has an insulating property between the substrate 1 and the holding surface 2A in advance. The seat 10 is interposed.

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 information recording medium, a substrate holder structure, and a film forming apparatus, and more particularly, to forming at least one film on a substrate by sputtering an optical disk or a magneto-optical disk. Suitable for use in the manufacture of information recording media manufactured by
The present invention relates to a method for manufacturing an information recording medium, a substrate holder structure, and a film forming apparatus.

[0002]

2. Description of the Related Art Optical disks and magneto-optical disks (hereinafter referred to as optical disks) are widely used as large-capacity, high-density information recording media. As a method of manufacturing these optical disks and the like, a method of forming a plurality of films such as a recording film and a protective film by sputtering on a substrate fixed to a holder is generally used.

In recent years, the substrates of these optical disks and the like have been made thinner. For example, once CD (Comp
The mainstream was a 1.2mm thick substrate for act disks).
At present, substrates having a thickness of 1.0 mm or less, and even a thickness of 0.6 mm, have been put to practical use. Further, in terms of manufacturing, shortening the sputtering time improves the production efficiency by shortening the tact time.

[0004]

The thinning of the substrate is indispensable for further increasing the capacity and the density of an optical disk or the like, and the improvement of the production efficiency is indispensable for meeting the needs for an optical disk or the like in the future. . However, when the thickness of the substrate is reduced, the heat capacity is reduced, so that the substrate tends to be heated to a high temperature at the time of film formation, and the warpage and distortion generated in the substrate are increased as compared with a thick substrate. Further, the shortening of the sputtering time is realized by increasing the sputter power. However, since increasing the sputter power causes an increase in the substrate surface temperature at the time of film formation, the warpage and distortion generated on the substrate become larger. I will. Since the warpage and distortion of the substrate degrade the quality of the optical disk and the like, the warpage and distortion of the substrate should be suppressed as much as possible while reducing the thickness of the substrate and improving the production efficiency by increasing the sputtering power. Is required.

In response to such a demand, for example, Japanese Patent Laid-Open
A technique disclosed in Japanese Patent Application Laid-Open No. 1-265529 (hereinafter referred to as prior art) has been proposed. In the prior art, a large heat capacity (2.3 ca) is provided between the holder and the substrate.
By interposing a spacer, the heat of the substrate is absorbed by the spacer to lower the temperature of the substrate at the time of film formation, thereby suppressing the warpage and distortion of the substrate.

By bringing the back surface of the substrate into contact with a spacer having a large heat capacity as in the prior art, it is possible to absorb the heat applied to the substrate by sputtering. However, in order to efficiently absorb the heat of the substrate and suppress a rise in the temperature of the substrate, not only the heat capacity of the spacer but also the thermal conductivity of the spacer are important factors. In other words, even if the heat capacity is large, if the thermal conductivity is small, the heat of the substrate cannot be efficiently absorbed and the heat cannot be quickly dissipated to the holder made of metal or alloy. In particular,
Nowadays, a large amount of heat is applied to the substrate in a short period of time by increasing the sputtering power to shorten the sputtering time. Has become.

In this regard, in the prior art, polycarbonate and copper are cited as examples of the material of the spacer.
Polycarbonate has a much lower thermal conductivity than metals such as copper. For this reason, when the spacer is made of polycarbonate, the temperature of the substrate may not be sufficiently lowered when the time during which the substrate and the spacer are in contact with each other is shortened due to the shortened sputtering time.

[0008] In sputtering, a high voltage is applied to a target to generate plasma.
If the support member (holder, spacer, etc.) that contacts the substrate is a conductive member such as a metal, a current flows in the support member toward a high electric field generated in the target. The current flowing in the support member generates Joule heat in the support member and raises the temperature of the support member.

For example, even when the spacer is formed of a metal such as copper as in the prior art, a current flows in the spacer. Therefore, even if the heat capacity of the spacer is large, if the temperature of the spacer increases due to the generated Joule heat, the amount of heat that can be absorbed by the spacer from the substrate decreases, and it is difficult to sufficiently suppress the increase in the temperature of the substrate. I can no longer do it.

As described above, according to the prior art, although a certain effect can be obtained for suppressing the rise in the temperature of the substrate by bringing the back surface of the substrate into contact with the spacer having a large heat capacity, the thermal conductivity and the thermal conductivity of the spacer can be improved. In view of the Joule heat generated in the spacer, it was not necessarily a sufficient solution. Also, if there is a scratch on the board, the quality of the product will deteriorate as well as the warpage and distortion of the board, but in the prior art, as in the case of directly contacting a spacer made of a hard material such as copper on the back surface of the board, No consideration was given to measures for damage to the substrate.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has been made in view of the above circumstances. Thus, an information recording medium capable of suppressing an increase in the temperature of a substrate during film formation by sputtering and producing an information recording medium with less warpage and distortion. It is an object of the present invention to provide a medium manufacturing method, a substrate holder structure, and a film forming apparatus. Further, the present invention, without damaging the substrate, suppresses the temperature rise of the substrate at the time of film formation by sputtering, so that it is possible to manufacture an information recording medium with less warpage and distortion, a method for manufacturing an information recording medium and It is an object to provide a substrate holder structure and a film forming apparatus.

[0012]

In order to achieve the above object, a method of manufacturing an information recording medium according to the present invention is to manufacture an information recording medium by forming at least one film on a substrate by sputtering. In the method, when sputtering is performed by mounting the substrate on a holder made of a metal or an alloy having a holding surface for holding the substrate, a first insulating film is provided between the substrate and the holding surface in advance. It is characterized in that one sheet is interposed. Here, that the first sheet has an insulating property means that the first sheet has high electric resistance, for example, that the volume resistivity is 1 × 10 ¹⁴ Ω · m or more. ing. There is no particular upper limit for the volume resistivity, but it is practically limited to 1 × 10 ¹⁶ Ω · m or less. Preferably, when the substrate is mounted on the holder with the first sheet interposed therebetween, the holding surface and the first surface of the first sheet, and the second surface of the first sheet and the substrate To the backside of the film formation region.

As the first sheet, it is preferable to use a sheet formed of a material softer than the substrate. It is also preferable to use a sheet having a thickness of 0.1 mm or more and 0.4 mm or less as the first sheet. More preferably, a sheet having a thickness of 0.1 mm or more and 0.2 mm or less is used. The thermal conductivity of the first sheet is
It is preferably at least 1.0 W / m · ° C. More preferably, a sheet having a thermal conductivity of 3.0 W / m · ° C. or more is used. There is no particular upper limit on the thermal conductivity, but it is practically limited to 100 W / m · ° C. or less.

More preferably, when the substrate is mounted on the holder with the first sheet interposed therebetween, an outer peripheral portion of the substrate has a portion facing the holder and an insulating portion is provided on the facing portion. The outer periphery of the substrate is covered with a mask (outer mask) provided with a second sheet having a property, and the substrate is pressed and fixed to the holder. More preferably, the substrate is mounted via the first sheet to the holder supported on the holder supporting portion of the support arm made of metal or alloy via a third sheet having insulation properties. Preferably,
The second sheet and the third sheet also have a thickness of 0.1 m.
m to 0.4 mm and a thermal conductivity of 1.0 W / m ·
C or higher. More preferably, 0.1 mm or more and 0.2
mm or less. It is more preferable that the thermal conductivity is 3.0 W / m · ° C. or more. There is no particular upper limit on the thermal conductivity, but it is practically limited to 100 W / m · ° C. or less. When a mask (inner mask) that covers the inner peripheral portion of the substrate and the holder are close to each other, it is preferable that an insulating sheet is also interposed between the opposing portions. Preferably, a cooling medium for cooling the holder is circulated in the support arm. In attaching the holder to the support arm via a metal screw, it is also preferable to insert an insulator bush in the insertion portion of the holder through which the screw is inserted.

Further, in order to achieve the above object, the substrate holder structure of the present invention has the following configuration. That is, a substrate holder structure of a film forming apparatus for forming at least one or more films on a substrate by sputtering, a metal holder having a holding surface for holding the substrate, and a first insulating film Sheet. Then, the first sheet is interposed between the substrate and the holding surface of the holder, and the substrate is held by the holder via the first sheet. In addition, that the first sheet has an insulating property means that the first sheet has high electric resistance, for example, that the volume resistivity is 1 × 10 ¹⁴ Ω · m or more. I have. There is no particular upper limit for the volume resistivity, but it is practically limited to 1 × 10 ¹⁶ Ω · m or less.

According to another aspect of the present invention, there is provided a film forming apparatus having the above-mentioned substrate holder structure, wherein at least one film is formed by sputtering on the substrate held by the substrate holder structure. It is characterized by having been constituted. In the above-described method for manufacturing an information recording medium, the substrate holder structure, and the film forming apparatus according to the present invention, the “information recording medium” refers to a first film on which at least one film including at least a recording layer is formed. A phase change optical recording medium, a magneto-optical recording medium, a dye optical recording medium, a magnetic recording medium including all recording media manufactured by bonding a second substrate to the substrate so as to sandwich the laminated film. It is not limited to a recording method such as a recording medium. In the present invention, the term “film” refers to, for example, a film composed of a protective layer / phase-change recording layer / protective layer / reflective layer in the case of a phase-change optical recording medium. If present, it refers to, for example, a film composed of a protective layer / magnetic recording layer / protective layer / reflective layer.

Although the thickness of the "substrate" to which the present invention can be applied is not limited, a thin substrate has a large warp due to a rise in the temperature of the substrate during film formation. It is suitable for use. However, in order to maintain the strength as a substrate, a thickness of 0.2 mm or more is required.
Also, the material of the “substrate” is not limited, but resin substrates such as polycarbonate, amorphous polyolefin, and polyacrylate are particularly suitable to be used for these resin substrates because they are likely to be warped or deformed due to a temperature rise of the substrate. It is.

In the present invention, the “one or more films” formed by sputtering include, for example, in the case of a phase change type optical recording medium, for example, from a protective layer / phase change recording layer / protective layer / reflective layer. In the case of a magneto-optical recording medium, it refers to, for example, a film composed of a protective layer / magnetic recording layer / protective layer / reflection layer. In the case of a dye-type optical recording medium, it refers to, for example, a reflective layer film. .

[0019]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show a film forming apparatus according to an embodiment of the present invention. The present film forming apparatus is configured as a film forming apparatus for manufacturing an optical information recording medium (optical disk) using polycarbonate as a substrate.

First, the overall configuration of the present film forming apparatus will be outlined with reference to FIG. As shown in FIG. 1, the present film forming apparatus has a multi-sided (eight in FIG. 1) transfer chamber 20 in which the inside is maintained in a vacuum, and a plurality of transfer chambers (in FIG. (Seven chambers). Film forming chamber 21
A transfer port 22 for transferring the substrate 1 for film formation to and from a production line is provided on the other surface of the transfer chamber 20 where the transfer chamber 20 is not provided. In addition, each film forming chamber 21
The transfer chamber outer wall 24 that separates the transfer chamber 20
Is formed in each of the film forming chambers 21. Then, in each of the film forming chambers 21, an inlet 24 is provided.
The target 3 is arranged toward A.

A transfer device 23 for transferring the substrate 1 is provided inside the transfer chamber 20. Transport device 23
Is provided with a holder 2 for fixing the substrate 1 and an arm 5 for supporting the holder 2 corresponding to each surface of the transfer chamber 20.
The substrate 1 put into the transfer chamber 20 from the delivery port 22 is fixed to one of the holders 2 of the transfer device 23,
Are sequentially transported to the respective film forming chambers 21 by the rotation of. The transfer device 23 has a function of expanding and contracting the arm 5 in the axial direction. The transfer device 23 extends the arm 5 in the axial direction at the inlet 24A of each of the film forming chambers 21 so that the substrate 1 approaches the target 3. ing. Then, when the substrate 1 enters the inlet 24A and approaches the target 3,
Sputtering is performed, and a film is formed on the substrate 1. When sputtering is sequentially performed in each of the film forming chambers 21 and all the film forming is completed, the substrate 1 on which the film forming is completed is again delivered from the delivery port 22 to the production line side.

Next, the main part of the present film forming apparatus will be described. In the present film forming apparatus, in the step of forming a film on the substrate 1 in the film forming chamber 21, the film is formed by sputtering without damaging the substrate 1. It is configured to suppress an increase in the temperature of the substrate 1 during film formation and to manufacture an optical disk with less warpage and distortion. Here, FIG. 2 is a schematic side sectional view showing a substrate holder structure which is a main part of the present film forming apparatus.

As shown in FIG. 2, in the substrate holder structure of the present film forming apparatus, between the holder 2 and the substrate 1, between the holder 2 and the arm 5, and between the holder 2 and the outer mask 6,
Insulating sheet (first sheet) 10, insulating sheet (third sheet) 11, insulating sheet (second sheet) 1, respectively
2 is interposed. The holder 2 is a disk made of stainless steel, and is provided on the film forming chamber 21 side so as to face substantially the entire back surface of the substrate 1 (at least the entire back surface of the film forming region).
A is formed. The insulating sheet 10 is attached on the holding surface 2A. The back surface of the substrate 1 is pressed against the holding surface 2A to which the insulating sheet 10 is attached by the inner mask 7 and the outer mask 6, is fixed to the holding surface 2A via the insulating sheet 10, and has an inner peripheral portion and an outer peripheral portion. Each part is masked.

The holder 2 and the arm 5 are connected to a metal screw 4
Are connected by screwing at a plurality of locations.
The arm 5 is made of stainless steel like the holder 2, and has a cooling medium passage 15 formed therein for conducting a cooling medium (cooling water or cooling air). As described above, the insulating sheet 11 is interposed at the connecting portion between the holder 2 and the arm 5 to prevent direct contact between the holder 2 and the arm 5. An annular step is formed on the outer peripheral portion of each of the holder 2 and the arm 5, and an annular plastic ring 8 is interposed between these steps.

The holder 5 has an arm 5 from the holding surface 2A side.
A plurality of through-holes 2C are drilled toward the connection surface 2B side. A plastic bush 9 having a screw hole is fitted into each through hole 2C, and a screw 4 is screwed into the bush 9. The screw 4 penetrates the connecting surface 2B side of the holder 2 without directly contacting the holder 2, and the arm 5
Threaded into the screw holes provided in.

A pair of arm valve plates 1 are provided above and below the arm 5.
6, 16 are provided. The arm 5 is configured to be rotatable around the axis in the arm valve plates 16.
A vacuum seal 17 is interposed between the distal end of the arm valve plate 16 and the outer wall 24 of the transfer chamber, and a vacuum magnetic seal 18 is interposed between the arm valve plate 16 and the arm 5. . The seals 17 and 18 prevent the gas (sputtering gas) in the film forming chamber 21 from leaking to the transfer chamber 20 side.

The insulating sheet 10 used in the present film forming apparatus,
The conditions of 11 and 12 are that they have at least electric insulation, that is, they have extremely high electric resistance. For example,
Teflon (trade name), silicon, resin, rubber, and the like are examples of the material of the insulating sheets 10, 11, and 12. Further, an insulating sheet 1 interposed between the substrate 1 and the holder 2
Regarding 0, it is preferable that the material is softer than the substrate 1 made of polycarbonate (for example, an elastic body such as rubber). The thinner the insulating sheets 10, 11, and 12, the easier the heat transfer becomes.
The thickness of the insulating sheet 10 interposed between the holder 1 and the holder 2 is set to be about 0.1 mm to 0.4 mm in consideration of maintaining insulation and maintaining elasticity for protecting the substrate 1. It is suitable.

In consideration of the heat conductivity from the substrate 1 to the holder 2, it is preferable that at least the insulating sheet 10 is formed of a material having a high thermal conductivity. For example, heat radiation rubber manufactured by Shin-Etsu Chemical Co., Ltd. (product name: TC-20)
A sheet (hereinafter, referred to as a BN sheet) containing boron nitride (BN) powder as a component, such as BG), is suitable as the insulating sheet 10 of the present film forming apparatus. This BN sheet is flame-retardant, has a very high volume resistivity of 8 × 10 ¹⁴ Ω · m, and has a high thermal conductivity of 3.8 W / m · ° C. It is known (by the way, about 0.19 W / m · ° C for polycarbonate). The hardness is 90 JIS as measured by JIS K6301 method.
It is elastic at about -A and is softer than polycarbonate or the like. In addition, it is preferable to use this BN sheet also for the other insulating sheets 11 and 12 in consideration of thermal conductivity. Further, regarding the shape of the insulating sheet 10,
It is preferable that the insulating sheet 10 has a shape that comes into contact with the entire surface of the substrate 1 in order to improve thermal conductivity and enhance insulating properties. However, depending on the case, a substrate smaller than the substrate 1 or a substrate having an appropriate hole may be used. Insulation sheet 1
The same applies to the shapes of the insulating sheets 1 and 12.
It is preferable that the shapes 1 and 12 are in contact with the entire surface between the holder 2 and the arm 5 and between the holder 2 and the outer mask 6. May be used.

Next, the operation and effect of the film forming apparatus according to one embodiment of the present invention configured as described above when forming a film by sputtering will be described. When a high voltage is applied to the target 3 by the high frequency power supply, plasma is generated in the sputtering gas between the substrate 1 and the target 3. The argon in the sputtering gas is ionized by the plasma, and is attracted to the target 3 by the high electric field and collides with the surface of the target 3. Then, the argon ions which collide with the target 3 strike out the metal element forming the target 3 from the surface of the target 3. The metal element struck out of the target 3 is laminated on the substrate 1 disposed to face the target 3, thereby forming a film on a region of the substrate 1 that is not masked by the inner mask 7 and the outer mask 6. Will be applied.

At this time, a large amount of heat is also applied to the substrate 1 as the metal element is deposited on the surface. However,
In the present film forming apparatus, the stainless steel holder 2 having high thermal conductivity and heat capacity is adhered to the entire back surface of the film forming area of the substrate 1, so that the heat of the substrate 1 is quickly absorbed by the holder 2, Temperature rise is suppressed. Further, since the cooling medium flows through the arm 5 supporting the holder 2, a rise in the temperature of the holder 2 is also suppressed, and a decrease in the efficiency of absorbing heat from the substrate 1 is prevented.

The insulating sheet 1 is provided between the substrate 1 and the holder 2 and between the holder 2 and the arm 5.
0, 11 are interposed, but these insulating sheets 10,
Since 11 is extremely thin (0.1 to 0.4 mm), even when the thermal conductivity per unit thickness is somewhat low, heat transfer from the substrate 1 to the holder 2 and heat transfer from the holder 2 to the arm 5 Will not be greatly hindered. In particular, the BN described above
Since the sheet has a high thermal conductivity of 3.8 W / m · ° C., heat can be efficiently transmitted from the substrate 1 to the holder 2 or from the holder 2 to the arm 5. The rise can be effectively suppressed.

In the present film forming apparatus, the substrate 1 and the holder 2
The insulating sheet 10 is interposed between the
Since the target and the holder 2 are electrically insulated from each other, no current is induced in the holder 2 even when a high electric field is generated in the target 3. Since the contact portion between the holder 2 and the outer mask 6 is also electrically insulated by the insulating sheet 12, the holder 2 is passed through the outer mask 6.
No current flows inside. Further, the holder 2 and the arm 5 are electrically insulated by the insulating sheet 10 and the plastic ring 8, and the screw 4 connecting the holder 2 and the arm 5 and the holder 2 are also insulated by the bush 9. Therefore, no current flows between the arm 5 and the holder 2. That is, in the present film forming apparatus, the holder 2 is completely electrically insulated. Therefore, no Joule heat is generated in the holder 2, and the heat capacity that can be absorbed from the substrate 1 does not decrease due to the temperature rise of the holder 2 itself.

As described above, according to the present film forming apparatus, the heat applied to the substrate 1 at the time of film formation by sputtering can be efficiently absorbed by the holder 2 and the temperature rise of the substrate 1 can be suppressed. In addition, there is an advantage that warpage and distortion of the substrate 1 can be suppressed. Further, since the substrate 1 is not directly adhered to the holder 2 but is fixed to the holder 2 with an insulating sheet 10 softer than the substrate 1, even if the substrate 1 slides on the holder 2, the substrate 1 There is also an advantage that no scratches are made.

Therefore, by manufacturing an optical disk using the present film forming apparatus, that is, in forming a film by sputtering, an insulating sheet 10 is interposed between the substrate 2 and the holder 2 so that the optical disk is always high. It is possible to manufacture a quality optical disc.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and it is a matter of course that various modifications can be made without departing from the spirit of the present invention. It is. For example, in the method of manufacturing an information recording medium according to the present invention, the insulating sheet 10 does not always need to be always provided in the holder 2, and when performing film formation by sputtering, the insulating sheet 10 is attached to the substrate 2 every time the substrate 2 is mounted on the holder 2 in advance. You may make it interpose between the holder 2 and. The same applies to the insulating sheet 11 interposed between the holder 2 and the outer mask 6. When the inner ring 7 and the holder 2 come into contact with each other, the above-described insulating sheet may be sandwiched between the contact portions.

In this embodiment, stainless steel is used as the material of the holder 2 and the arm 5. However, general metals such as iron and aluminum can be used. Further, the material of the substrate 1 is not limited to polycarbonate, and various materials can be used. Furthermore, bush 9 and ring 8
The material is not limited to plastic, and may be any material having an insulating property.

The present invention can be applied not only to optical discs but also to information recording media manufactured by depositing at least one film on a substrate by sputtering, including magneto-optical discs.

[0038]

The present invention will be described in more detail with reference to the following examples. <Embodiment> In this embodiment, a phase change optical disk was manufactured using a manufacturing apparatus having the manufacturing steps shown in FIG. The manufacturing process consists of a molding process, a cooling process, a film forming process, a cooling process, a protective coating process, an inspection process, a bonding process, an initialization process, and a final inspection process, and those that pass the final inspection are stored as products. .

In the molding step, "SD-30" manufactured by Sumitomo Heavy Industries, Ltd. was used as a molding apparatus. The molding apparatus is an apparatus for molding a substrate by injection molding, and includes a fixed mold and a movable mold. The stationary mold is provided with a stamper having irregularities formed on the surface, and a resin for molding the substrate 1 is injected from the surface of the movable mold so that the surface shape of the stamper is transferred to the surface of the substrate. Has become. In this example, a substrate made of polycarbonate having a thickness of 0.6 mm and a diameter of 12 cm was manufactured using the above-mentioned molding apparatus.

Then, the substrate was taken out of the molding apparatus, cooled, and after two minutes passed from the taking out, the substrate was introduced into a film forming apparatus having the structure shown in FIG. "SMO-01PC" manufactured by Japan Vacuum Engineering Co., Ltd. was used as a film forming apparatus. Explaining using the reference numerals in FIG. 1, each film forming chamber 21 of the film forming apparatus is 5 × 10 ⁻³ P
It is exhausted to below a. When the substrate 1 enters the introduction / discharge chamber, the introduction / discharge chamber is evacuated by the roughing pump for 1 to 2 seconds. And
The arm 5 is moved to the first film forming chamber 21 and extended to form the film forming chamber 2.
The vacuum between 1 and the transfer chamber becomes independent. Subsequently, the film forming chamber 21
Argon gas is introduced until a pressure of 0.4 Pa is reached,
The film is formed by applying a power of 5000 W. The diameter of the target 3 was 200 mm. After the film formation in the first film formation chamber 21 is completed, the arm 5 contracts again and the substrate 1 moves to the transfer chamber 20. Then, the film is moved to the next film forming chamber 21, and the film is formed in the same manner. After the film is formed in each of the film forming chambers 21 in this manner, the substrate 1 on which a plurality of films are formed on the surface is formed.
Is again discharged from the film forming apparatus after entering the introduction / discharge chamber.

In this embodiment, the layer structure of the film formed on the substrate is, in order from the surface of the substrate, ZnS—SiO ₂ thickness 70 nm / GeInSbTe thickness 15 nm / ZnS—S
The thickness of iO _{2 is} 20 nm / the thickness of AlTa is 200 nm.
These films were formed by setting the film forming conditions of each film forming chamber 21 in the film forming apparatus as shown in Table 1 below.

[0042]

[Table 1]

As shown in Table 1 above, the first film forming chamber is not used here because it is not necessary. Further, the film forming chamber of the 2nd and 3rd was formed of the same film (ZnS-SiO _2). This is because we wanted to increase the thickness of the ZnS-SiO _2.

FIG. 2 shows a substrate holder of the coating apparatus.
The configuration shown in FIG. Then, as the insulating sheet, a BN sheet made of a rubber product for heat radiation manufactured by Shin-Etsu Chemical Co., Ltd. was used. More specifically, the first and second sheets (indicated by reference numerals 10 and 11 in FIG. 2) have a thickness of 0.2 mm.
As a third sheet (indicated by reference numeral 12 in FIG. 2), “TC-20BG” having a thickness of 0.8 mm was used.
80BG "was used.

After the film formation in the film forming apparatus, a protective coat was formed on the surface of the substrate on which the film was formed. That is, after spin-coating the ultraviolet curable resin to a thickness of 3 to 10 μm,
It was cured by irradiation with UV light. After the pinhole inspection and the inspection of the amount of warpage were performed, a transparent substrate (dummy substrate) formed by adjusting the warpage in advance so as to sandwich the film formed on the substrate was bonded. Specifically, an adhesive is spin-coated on the surface of the substrate on which the protective coat is formed, a dummy substrate is directly placed on the substrate, and the adhesive is spun as it is to spread the adhesive over the entire surface, and then irradiated with UV light. The adhesive was cured to produce a bonded type phase change optical disk.

After initializing the phase-change optical disk manufactured as described above at a linear velocity of 4 m / S and a power of 1300 mV, the Dr. Schenk GmbH's "VCC-i"
sm "was used to perform a defect inspection and a warpage inspection. In this embodiment, about 2300 to 2400 phase-change optical disks were continuously manufactured by the above manufacturing process, and the continuous manufacturing was performed four times in total. Table 2 shows the results of the warpage inspection (the average value and the standard deviation of 2300 to 2400 sheets) of these disks by the inspection apparatus. In the warp inspection, a circumferential warp angle (circumferential tilt) and a radial warp angle (radial tilt) were measured for each disk. In the actual warp inspection, the inner circumference, the middle circumference, and the outer circumference of the disk are measured. However, since the warpage on the outer circumference side is usually the largest, Table 2 shows the measurement results especially on the outer circumference.

[0047]

[Table 2]

The allowable range of the disc as a product is within ± 800 mdeg for radial tilt and within ± 300 mdeg for circumferential tilt. As shown in Table 2, the test results for all four tests were significantly lower than these limits and were very stable without significant fluctuations each time.

<Comparative Example> As a comparative example with respect to the above embodiment, the same phase change type optical disk as that of the embodiment was manufactured without using each of the insulating sheets (first, second and third sheets).
As a result, the mirror side of the disk after film formation (the side where no film is formed,
That is, innumerable fine scratches were confirmed on the side in contact with the substrate holder), and 10% or more failed in the defect inspection. This scratch is presumed to have been caused by the movement (warpage) of the substrate due to the heat during film formation and the contact with the holder. In addition, the warpage immediately after the formation of the disk was large, and at the time of manufacturing, a transport trouble occurred in a bonding step or the like, and the apparatus was stopped at a frequency of once or more every 10 minutes.

From the results of the above Examples and Comparative Examples, it was confirmed that by applying the present invention to the production of an information recording medium, a high-quality information recording medium with little distortion and warpage can be produced.

[0051]

As described above in detail, according to the method for manufacturing an information recording medium of the present invention, when performing sputtering, the first sheet having insulating properties is previously provided between the substrate and the holding surface of the holder. With the interposition, the heat applied to the substrate at the time of film formation can be efficiently absorbed by the holder made of metal or alloy, and the generation of Joule heat in the holder can be prevented. This is advantageous in that a high-quality information recording medium with less distortion and warpage can be manufactured by suppressing the distortion.

In particular, when the substrate is mounted on the holder with the first sheet interposed therebetween, the holding surface of the holder and the first surface of the first sheet are brought into close contact with each other, and the second surface of the first sheet is brought into contact with the substrate. The heat applied to the substrate can be more efficiently absorbed by the holder by closely contacting the back surface of the film formation region. In addition, by using a sheet formed of a material softer than the substrate as the first sheet, it is possible to prevent the substrate from being damaged when the substrate is attached to the holder or when forming the film, and a high-quality information recording medium can be obtained. It becomes possible to manufacture.

Further, by using a sheet having a thickness of 0.1 mm or more and 0.4 mm or less as the first sheet,
It is possible to facilitate the transfer of heat from the substrate to the holder while maintaining the insulation and elasticity of the sheet. In particular,
By selecting a sheet material having a thermal conductivity of 1.0 W / m · ° C. or more as the first sheet, the transfer of heat from the substrate to the holder is further facilitated, and the temperature rise of the substrate is more effectively suppressed. It becomes possible to do.

Further, the holder is more reliably electrically insulated by interposing an insulating sheet also at a portion facing the holder and a mask which covers the outer peripheral portion of the substrate and presses and fixes the substrate against the holder. It becomes possible. Also,
By interposing an insulating sheet also at a contact portion between the metal support arm having a support portion for supporting the holder and the holder, the holder can be electrically insulated more reliably. When the holder is attached to the support arm via a metal screw, the holder can be more reliably electrically insulated by interposing an insulator bush at the screw insertion portion of the holder.

According to the substrate holder structure of the present invention,
By using a metal holder to hold the substrate via an insulating sheet, the heat applied to the substrate during film formation can be efficiently absorbed by the holder, and the generation of Joule heat inside the holder is prevented. Therefore, there is an advantage that an increase in the temperature of the substrate can be suppressed and an information recording medium with less distortion and warpage can be manufactured.

Further, according to the film forming apparatus of the present invention, the above-mentioned substrate holder structure is provided, and at least one layer is formed by sputtering on a substrate held by using the above-mentioned substrate holder structure. Accordingly, there is an advantage that an increase in the temperature of the substrate can be suppressed and an information recording medium with less distortion and warpage can be manufactured.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating an overall configuration of a film forming apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic side sectional view showing a configuration of a substrate holder structure according to one embodiment of the present invention.

FIG. 3 is a diagram showing a manufacturing process of the information recording medium according to one embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 substrate 2 holder 2A holding surface 3 target 4 screw 5 arm 6 outer mask 7 inner mask 8 plastic ring 9 bush 10 insulating sheet (first sheet) 11 insulating sheet (third sheet) 12 insulating sheet (second sheet) 15 Cooling medium passage 20 Transfer chamber 21 Deposition chamber 23 Transfer machine 24 Transfer chamber outer wall

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Atsushi Megumi Jurong Pioneer Aldo 103 Singapore Chemical Electronics Pty Ltd. 4K029 AA11 BA02 BA03 BA10 BA14 BA16 BA18 BA21 BA32 BA35 BA46 BA51 BB02 BD12 CA05 DC27 HA04 JA05 KA01 KA09 5D121 AA03 EE03 EE19 EE20 EE27

Claims (10)

[Claims] 1. A method of manufacturing an information recording medium by forming at least one film on a substrate by sputtering, comprising: a metal or alloy holder having a holding surface for holding the substrate; A method for manufacturing an information recording medium, comprising: interposing an insulating first sheet between the substrate and the holding surface in advance when performing sputtering with the substrate mounted. 2. When the substrate is mounted on the holder with the first sheet interposed therebetween, the holding surface and the first surface of the first sheet are brought into close contact with each other, and Characterized in that the two surfaces and the back surface of the film formation region of the substrate are brought into close contact with each other,
A method for manufacturing an information recording medium according to claim 1. 3. The method for manufacturing an information recording medium according to claim 1, wherein a sheet formed of a material softer than the substrate is used as the first sheet. 4. The thickness of the first sheet is 0.1 mm.
The method for manufacturing an information recording medium according to any one of claims 1 to 3, wherein a sheet having a thickness of at least 0.4 mm or less is used. 5. The thermal conductivity of the first sheet is 1.0.
The method for manufacturing an information recording medium according to claim 1, wherein a sheet having a temperature of W / m · ° C. or more is used. 6. When mounting the substrate on the holder with the first sheet interposed therebetween, an outer peripheral portion of the substrate has a facing portion with the holder and an insulating portion on the facing portion. The information recording medium according to any one of claims 1 to 5, wherein an outer peripheral portion of the substrate is covered by a mask provided with the two sheets, and the substrate is pressed and fixed to the holder. Manufacturing method. 7. The substrate is mounted via the first sheet on the holder supported on the holder supporting portion of the support arm made of metal or alloy via a third sheet having insulation properties. The method for manufacturing an information recording medium according to claim 1. 8. The mounting according to claim 7, wherein when the holder is attached to the support arm via a metal screw, a bush made of an insulator is interposed in a portion of the holder through which the screw is inserted. Manufacturing method of information recording medium. 9. A substrate holder structure of a film forming apparatus for forming at least one film on a substrate by sputtering, comprising: a metal holder having a holding surface for holding the substrate; And a first sheet having the first sheet, wherein the first sheet is interposed between the substrate and the holding surface. 10. A substrate holder structure according to claim 9, wherein at least one film is formed by sputtering on said substrate held by using said substrate holder structure. A film forming apparatus.