JP2008282495A - Glass substrate for use in unexposed master disk for optical recording medium, surface modification method therefor and surface modification apparatus therefor, and surface modification system thereof, and unexposed master disk for the optical recording medium and method of manufacturing master disk for the optical recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a glass substrate for use in an unexposed master disk for optical recording medium and a surface modification method therefor, or the like, capable of suppressing increase in costs, because not only adhesion between a photoresist material and a surface of the glass substrate is improved, but also a photoresist layer can be laminated on the surface of the glass substrate, using an apparatus of existing simple structure. <P>SOLUTION: The surface modification method for the glass substrate for use in the unexposed master disk for optical recording medium is such that the glass substrate is heated in a dry atmosphere, and an adhesive agent is provided on the surface of the glass substrate to perform surface modification. It is preferred that after the adhesive agent is provided, the glass substrate be cooled in the dry atmosphere, until the surface temperature of the glass substrate reaches a temperature at which the photoresist material can be applied on the surface of the glass substrate. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a glass substrate used for an unexposed master for an optical recording medium, a surface modification method for a glass substrate used for an unexposed master for an optical recording medium, and an optical recording medium, which are preferably used for manufacturing an optical recording medium stamper. Apparatus for surface modification of glass substrate used for unexposed master for optical disk, surface modification system for glass substrate used for unexposed master for optical recording medium, unexposed master for optical recording medium, and method for producing master for optical recording medium About.

In recent years, due to an increase in the amount of information, large amounts of information such as application software, music, images (still images, moving images), and various data are generally stored and distributed and sold on optical recording media. Yes.
As such an optical recording medium, read-only optical recording media such as CDs, CD-ROMs, and DVD-ROMs are widely used. The optical recording medium has a structure in which recording information is formed in advance as pits on a substrate, and a reflective layer and a protective layer are laminated on the substrate.
On the other hand, recordable optical recording media such as CD-R / RW, DVD + R / RW, and DVD-R / RW are also widely used. In the optical recording medium, time information is recorded in a groove (guide groove) on the substrate, and on the substrate, a recording layer (CD-R, DVD + R, DVD-R, organic dye, etc., CD-RW, DVD + RW, It has a structure in which an inorganic phase change film (DVD-RW), a reflective layer, and a protective layer are laminated. In this optical recording medium, time information and data are recorded by writing pits with an optical recording device.

Recently, HD format and BD format optical recording media having larger capacities than the optical recording media have been put into practical use. In such a large-capacity optical recording medium, since the grooves or pits are arranged in the optical recording medium with high density, it is necessary to form and arrange the groove patterns or pit patterns more finely.
An injection molding method with a short manufacturing cycle is most suitable for the substrate molding step in such an optical recording medium manufacturing method in terms of mass production and cost, and is generally used. In the injection molding method, a stamper is used in which grooves and pits are formed in the reverse direction from the substrate.

Here, a general stamper manufacturing method will be described with reference to the drawings. First, as shown in FIG. 1A, the surface of the glass substrate 1 having a diameter equal to or larger than the diameter of the stamper is polished, washed, and dried.
Next, as shown in FIG. 1B, a photoresist layer 2 is formed on the surface of the glass substrate 1 to produce an unexposed master 8 for an optical recording medium. The photoresist layer 2 is usually formed on the surface of a glass substrate by applying a liquid photoresist material by spin coating or the like.
Next, as shown in FIG. 1C, a groove pattern or a pit pattern is formed on the photoresist layer 2 by irradiating with laser light using an exposure apparatus as shown in FIG. In FIG. 2, 4 represents a gas laser, 5 represents a mirror, 6 represents an EOM (Electro Optical Modulator), 7 represents a lens, and 8 represents an unexposed master for an optical recording medium.
Next, as shown in FIG. 1D, an alkaline developer is applied onto the optical recording medium exposure master 80 by a developing device (not shown), so that when the photoresist material is a positive type, a latent image is obtained. The part becomes alkali-soluble and is removed. Next, a groove pattern or a pit pattern corresponding to the optical recording medium substrate is formed on the optical recording medium exposure master 80 by post-baking.
Next, as shown in FIG. 1E, an exposure master 80 for optical recording medium on which a pattern is formed is formed by forming a metal film such as nickel by sputtering and performing electroforming by plating. 3 is formed.
Next, as shown in FIG. 1F, the metal plate 3 is peeled off from the glass substrate 1, and steps such as cleaning of the photoresist material and the like remaining on the metal plate 3, cutting with a press machine, and polishing are performed. As a result, the stamper 81 used for molding the optical recording medium substrate shown in FIG. 1G can be manufactured.

  In such a series of stamper manufacturing processes, the formation of the photoresist layer B in FIG. 1 is particularly important. In the formation of the photoresist layer, when a liquid photoresist material is applied to the glass substrate by a normal spin coating method, hydrogen bonding occurs between water molecules remaining on the glass substrate surface and the hydroxyl group of the photoresist material. The adhesion of the photoresist material to the glass substrate is reduced. Due to this influence, the thickness unevenness may occur in the photoresist layer formed on the glass substrate surface. Even if the thickness non-uniformity does not occur, if the unexposed master for optical recording medium is used and the exposure process and the development process are performed, the pattern formed by the laser beam is broken and the land is moved. Therefore, there is a problem that a desired pattern shape cannot be obtained due to a non-uniform groove shape or a part or all of the pattern being lost.

  As a means for solving the above problems, it is conceivable to improve the adhesion between the glass substrate and the photoresist material. For example, an attempt has been made to apply an adhesive (primer) such as hexamethylene disilazane (HMDS), a silane coupling agent, or a titanium coupling agent to the surface of a glass substrate before application of a photoresist material. In the case of HMDS, OH groups in the multi-molecular layer of water remaining on the surface of the glass substrate 1 react with HMDS as shown in FIG. 3A to be modified to trimethylsilanol groups as shown in FIG. 3B. Thus, it becomes hydrophobic and the adhesion of the photoresist material to the glass substrate surface can be improved.

As a means for improving the adhesion between the photoresist material and the glass substrate, for example, Patent Document 1 proposes a method of applying HMDS twice or more to the surface of the glass substrate before applying the photoresist material. . According to this proposal, it is said that the adhesion between the photoresist material and the glass substrate is improved as compared with the case where HMDS is applied only once.
However, in Patent Document 1, when there is a lot of moisture remaining on the glass surface, even if HMDS is applied multiple times, there is almost no effect, and the exposure pattern may completely flow out after development. In particular, when a fine pattern such as BD or HD is formed by a glass etching method, a polished quartz glass having a small surface roughness and a high smoothness is used. This quartz glass has been used conventionally. Since there is more moisture remaining on the surface than soda lime glass (blue plate glass), this problem is likely to occur.

Patent Document 2 proposes a method in which a titanium coupling agent is used as an adhesive and a diluted solution of the adhesive is applied to the glass substrate surface by a spin coating method. In general, a titanium coupling agent has higher adhesion than HMDS, and it is considered that adhesion between the photoresist material and the glass substrate surface is improved.
However, since the titanium coupling agent to be applied is a diluted solution, there is a high possibility of crystallization during drying, and the crystallized titanium coupling agent causes spots and unevenness on the stamper. Defects occur. In order to prevent this crystallization, the photoresist material must be applied without exposing the glass substrate once coated with the titanium coupling agent to the air, and the apparatus for applying the titanium coupling agent by the spin coating method And a device for applying a photoresist material by spin coating must be integrated in a container. As a result, independent spin coaters for existing adhesives / photoresist materials cannot be used. In addition to costing the integrated device, cleaning of the excess titanium coupling agent crystals and photoresist material residue deposited in the device by swinging off is also necessary to prevent defect adhesion. Therefore, there is a problem that the maintenance is troublesome because the frequency is high.

Patent Document 3 proposes a method in which a vapor gas of an adhesive is applied to the surface of a glass substrate in a container and a photoresist material is applied. According to this proposal, the thickness of the photoresist layer is made uniform and the occurrence of defects can be suppressed as compared with the case where the adhesive is applied in a liquid.
However, in this proposal as well, as in Patent Document 2, it is necessary to integrate an apparatus for applying an adhesive by a spin coating method and an apparatus for applying a photoresist material in a container, and the cost for the apparatus is reduced. Take it. In addition, since the extra photoresist material is scattered in the container by the spin-off of the spin coating method, it is necessary to frequently perform cleaning as a countermeasure for preventing defects in the container, and there is a problem that the process becomes complicated. .

Japanese Patent Laid-Open No. 2003-21917 JP-A-10-222878 JP 2001-160242 A

  An object of the present invention is to solve the above-described problems and achieve the following objects. That is, the present invention can improve the adhesion between the photoresist material and the glass substrate surface even when there is a large amount of moisture remaining on the glass substrate surface. Since a photoresist layer can be laminated on the substrate surface, a glass substrate used for an unexposed master for an optical recording medium, which can obtain a desired pattern shape, has few defects, and can suppress cost increase due to yield reduction, Surface modification method for glass substrate used for unexposed master for optical recording medium, surface modification device for glass substrate used for unexposed master for optical recording medium, and surface modification for glass substrate used for unexposed master for optical recording medium It is an object of the present invention to provide a system, an unexposed master for an optical recording medium, and a method for manufacturing an optical recording medium master.

  In order to solve the above-mentioned problems, the present inventors have conducted intensive studies to solve the problem that the adhesiveness to the photoresist material is low due to a large amount of moisture remaining on the surface. The surface of the glass substrate is improved by applying an adhesive to improve the adhesion between the photoresist material and the glass substrate surface, a desired pattern shape is obtained, and there are few defects. It was found that the cost increase due to the yield reduction can be suppressed.

The present invention is based on the above findings by the present inventors, and means for solving the above problems are as follows. That is,
<1> A surface modification method for a glass substrate used for an unexposed master for an optical recording medium, wherein the glass substrate is heated in a dry atmosphere, and an adhesive is applied to the surface of the glass substrate to modify the surface. is there.
<2> The light according to <1>, wherein after the adhesion agent is applied, the glass substrate is cooled in a dry atmosphere until the surface temperature of the glass substrate reaches a temperature at which a photoresist material can be applied to the glass substrate surface. This is a method for modifying the surface of a glass substrate used for an unexposed master for a recording medium.
<3> The method for modifying a surface of a glass substrate used for an unexposed master for an optical recording medium according to any one of <1> to <2>, wherein the glass substrate is a quartz glass substrate.
<4> The method for modifying a surface of a glass substrate used for an unexposed master for an optical recording medium according to any one of <1> to <3>, wherein the glass substrate is heated using a hot plate.
<5> The method for modifying a surface of a glass substrate used for an unexposed master for an optical recording medium according to any one of <1> to <4>, wherein the heating temperature of the glass substrate is 70 ° C. or higher.
<6> The surface of the glass substrate used for the unexposed master for optical recording media according to any one of <1> to <5>, wherein the adhesive is at least one selected from a silazane compound and a silane coupling agent. It is a reforming method.
<7> The method for modifying a surface of a glass substrate used for an unexposed master for an optical recording medium according to <6>, wherein the silazane compound is hexamethylene disilazane (HMDS).
<8> An unexposed master for an optical recording medium, which is surface-modified by the surface modification method according to any one of <1> to <7> and has a photoresist layer on the surface.
<9> Light that etches the glass substrate using a concavo-convex pattern of a photoresist layer formed by exposing and developing the unexposed master for an optical recording medium according to <8>. This is a method for manufacturing a recording medium master.
<10> a container filled with a dry atmosphere and containing a glass substrate;
Heating means for heating the glass substrate accommodated therein;
In the container, on the surface of the heated glass substrate, an applying means for applying an adhesive that modifies the surface;
An apparatus for modifying the surface of a glass substrate used for an unexposed master for an optical recording medium.
<11> The glass substrate surface modifying apparatus used in the unexposed master for optical recording media according to <10>, further including a supply / exhaust unit that supplies and exhausts dry air to and from the container.
<12> The glass substrate surface modifying apparatus according to any one of <10> and <11>, a container that accommodates the glass substrate that is filled with a dry atmosphere and is surface modified, and the accommodated A glass substrate surface modification system for use in an unexposed master for an optical recording medium, comprising: a cooling device provided with a cooling means for cooling the glass substrate.
<13> The cooling means has a low temperature part that cools the glass substrate at a low temperature,
<12>, wherein the cooling device further includes a jig that supports the glass substrate in a state of being in partial contact with the back surface of the glass substrate such that the low-temperature portion and the glass substrate have a gap. This is a glass substrate surface modification system used for an unexposed master for optical recording media.

  According to the present invention, conventional problems can be solved, and even when there is a large amount of moisture remaining on the glass substrate surface, the adhesion between the photoresist material and the glass substrate surface can be improved. Since a photoresist layer can be laminated on the surface of a glass substrate using an apparatus having a simple structure, an optical recording medium capable of obtaining a desired pattern shape, having few defects, and suppressing an increase in cost due to a decrease in yield Substrate used for unexposed master for optical recording, surface modification method for glass substrate used for unexposed master for optical recording medium, surface modifying apparatus for glass substrate used for unexposed master for optical recording medium, and unexposed for optical recording medium A glass substrate surface modification system used for a master, an unexposed master for an optical recording medium, and a method for manufacturing the master for an optical recording medium can be provided.

(Glass substrate used for unexposed master for optical recording medium, surface modification method, surface modification apparatus, and surface modification system)
A surface modification method for a glass substrate (hereinafter, also simply referred to as “glass substrate”) used for an unexposed master for an optical recording medium of the present invention comprises heating a glass substrate in a dry atmosphere, Adhesive is added to modify the surface.
In this case, after applying the adhesive, it is preferable to cool the glass substrate in a dry atmosphere until the surface temperature of the glass substrate reaches a temperature at which a photoresist material can be applied to the surface of the glass substrate.
In the present invention, the unexposed master for optical recording medium means a master before undergoing an exposure step in the method for producing an optical recording medium master of the present invention. Further, a master having a concavo-convex pattern formed on the photoresist layer after the exposure process and the development process is referred to as an exposure master for an optical recording medium.
The glass substrate surface modifying apparatus used for the unexposed master for optical recording media of the present invention comprises a container, a heating means, and an applying means, and further includes other means as required.
The glass substrate surface modification system used for the unexposed master for optical recording media of the present invention comprises the glass substrate surface modification device of the present invention, a container, and a cooling device. It has the structure of.
Hereinafter, the glass substrate used for the unexposed master for the optical recording medium of the present invention and the unexposed for the optical recording medium of the present invention through the description of the surface modification method of the glass substrate used for the unexposed master for the optical recording medium of the present invention. The details of the glass substrate surface modification apparatus used for the master and the glass substrate surface modification system used for the unexposed master for optical recording media of the present invention will also be clarified.

-Heating of glass substrate-
In the method for modifying a surface of a glass substrate used for an unexposed master for an optical recording medium of the present invention, the glass substrate is heated in a dry atmosphere.
The heating of the glass substrate is performed for the purpose of removing moisture and volatile impurities on the surface of the glass substrate, and there is no particular limitation as long as moisture and volatile impurities can be removed. It may be either during heating or after completion of heating.

The heating method is not particularly limited and may be appropriately selected depending on the purpose. Examples thereof include a hot plate, circulation of hot air, direct heating in a clean oven, and indirect heating in a clean oven. Can be mentioned. Among these, it is particularly preferable to use a hot plate. Since heat is easily transmitted to the glass substrate by using the hot plate, not only water in the container but also water molecules on the surface of the glass substrate can be easily removed. Moreover, since it becomes easy to make the surface temperature of the said glass substrate uniform, the surface modification nonuniformity in a surface and by extension, the thickness nonuniformity at the time of photoresist material application | coating can be prevented.
Specifically, the glass substrate is washed with ultrasonic waves, high-pressure water or the like and dried, and then placed on a hot plate in a previously heated container, and the container is sealed. At this time, it is preferable that the glass substrate is placed so that the surface on which the photoresist layer is formed is up and the back surface is in contact with the hot plate.
The time for discharging the moisture and impurities by placing the glass substrate on a hot plate and heating differs depending on the thickness of the glass substrate to be heated, but for a glass substrate having a thickness of about 1 mm, the glass substrate has a thickness of about 3 minutes and a thickness of about 6 mm. If the glass substrate is heated for about 15 minutes, it is sufficient to remove moisture on the surface of the glass substrate.

The heating temperature of the glass substrate is preferably 70 ° C. or higher, more preferably 80 ° C. or higher. Within this range, it is effective to increase the adhesion of the photoresist material to the glass substrate surface.
When forming a fine pattern with high linear density such as HD format or BD format, it is difficult to control the width of grooves and pits in the manufacturing method using only the exposure process from the photoresist layer and the development process. A process of forming a pattern from a recording medium exposure master by a glass etching method to form a stamper is also widely used. At this time, in order to facilitate the etching of the glass substrate itself, a polished glass made of quartz having a low surface roughness and high smoothness is used instead of the blue plate glass (soda lime glass) used in the normal stamper manufacturing process. . Water molecules are difficult to remove on the surface of the quartz glass substrate, and the adhesion of the photoresist material is lower than that of the blue plate glass.
Therefore, in the present invention, by setting the heating temperature of the glass substrate in a dry atmosphere to 70 ° C. or higher, water molecules are easily removed even on the surface of the quartz glass substrate, which is effective in improving the adhesion of the photoresist material. It is. In addition, it is possible to further shorten the time for exhausting moisture and impurities by heating the quartz glass substrate after it is placed on the hot plate.

  When the glass substrate is heated to form the photoresist layer by the method as described above, exhaust is performed while supplying (sealing) dry air (for example, nitrogen gas) into the container. As a result, it is possible to remove a trace amount of water molecules remaining on the surface of the glass substrate while removing moisture or impurities in the container or the tube enclosing the gas. Further, the inside of the container can be purged with nitrogen while removing impurities and moisture. The inside of the container is completely nitrogenated (replaced with a nitrogen atmosphere) by stopping the discharge from the container and continuing to send nitrogen. The dry air may be air whose humidity is controlled. In this case, it is preferable to remove impurities through an air filter.

-Application of adhesive-
Surface modification is performed by applying an adhesive to the surface of the glass substrate from which moisture has been removed by heating.
The application of the adhesive is not particularly limited as long as the adhesive can be applied to the surface of the glass substrate and the surface can be modified, and can be appropriately selected according to the purpose. Any of spraying of the agent-containing liquid and adhesion by sealing of the evaporating gas of the adhesive may be used. Among these, a method in which the vapor gas of the adhesion agent is sealed in a container and adhered to the glass substrate surface is particularly preferable.

When the adhesive is a liquid and is applied by spin coating, the hot plate that receives the glass substrate must also serve as a turntable for the spin coating apparatus, which not only makes the structure of the apparatus very complicated. The liquid adhesive remaining on the board surface must be spattered off. Therefore, the adhesive agent adheres to the inner wall of the container as well as the adhesive agent liquid itself, and impurities are easily derived. When this becomes a stamper through an exposure process, a development process, and an electroforming process, it may cause a defect in the stamper. Similarly, when the adhesive is applied radially by spray coating, defects are generated in the stamper due to the generation of impurities.
Therefore, the adhesive agent applied to the glass substrate surface in a dry atmosphere as in the present invention is a vapor-like evaporating gas, which simplifies the glass substrate surface modification process and is applied to the glass substrate surface and the next step. This is effective not only in increasing the adhesion with the photoresist material to be produced, but also in producing a stamper with few defects.
In addition, when the adhesion agent is attached to the glass substrate surface by enclosing the adhesion agent vapor gas in the container and adhering to the glass substrate surface, the adhesion agent is enclosed in a completely nitrogen-substituted container. It is preferable.
Here, FIG. 6 is a schematic view showing the pressurized tank 15 that releases the vapor gas of the adhesive. When discharging the liquid from the tank, the liquid is discharged from the side in contact with the liquid by filling the gas in a tube that is not in contact with the liquid and pressurizing it. In the present invention, the vapor gas is discharged from the tank. Therefore, on the contrary, nitrogen gas is sealed and pressurized in the tube 90 that is in contact with the adhesive liquid 16, and the generated vapor gas of the adhesive is discharged from the non-contact side tube 91. Since the inside of the pressurized tank 15 is also replaced with nitrogen, a vapor gas of an adhesive having almost no impurities is sealed from the pressurized tank 15 into a container in which the glass substrate for surface modification is heated. It can be applied to the substrate surface. More preferably, an air filter for gas is installed between the pipes from the pressurized tank to the container, and the vapor gas of the adhesive agent sealed in the container is passed through.

  The vapor gas of the adhesion agent is sealed in a container in which a glass substrate for surface modification is heated, and the adhesion time differs depending on the material and size of the glass substrate, but cannot be specified unconditionally, If sealed for 90 seconds or more, water molecules on the glass substrate surface are hydrophobized, and the adhesion between the glass substrate surface and the photoresist material can be increased. Further, because of the surface modification treatment with the vapor gas, it is possible to prevent the occurrence of defects after the stamper formation due to the generation of impurities.

There is no restriction | limiting in particular as said contact | adherence agent, According to the objective, it can select suitably, For example, a silazane compound, a silane coupling agent, a titanium coupling agent etc. are mentioned. Of these, silazane compounds and silane coupling agents are particularly preferred.
The silazane compound is a silicon compound having a Si—N bond in the molecule, and is also called an organosilazane. For example, hexamethyldisilazane, hexaphenyldisilazane, dimethylaminotrimethylsilane, trisilazane, cyclotrisilazane, 1 1,3,3,5,5-hexametacyclotrisilazane and the like. Among these, hexamethyldisilazane (HMDS) is particularly preferable because it is relatively easy to handle.

  There is no restriction | limiting in particular as said silane coupling agent, According to the objective, it can select suitably, For example, N-2 (aminoethyl) 3-aminopropyl methyl dimethoxysilane which consists of an amino-type functional group, 3-aminopropyl Triethoxysilane; 3-glycidoxypropyltrimethoxysilane composed of an epoxy-based functional group, 2- (3,4 epoxycyclohexyl) ethyltrimethoxysilane; 3-methacryloxypropylmethyldimethoxysilane composed of a methacryloxy-based functional group, 3 -Methacryloxypropyltriethoxysilane; vinyltrimethoxysilane and vinyltriethoxysilane composed of vinyl functional groups.

  The titanium coupling agent is not particularly limited and may be appropriately selected depending on the intended purpose. For example, tetraisopropyl titanate, tetranormal butyl titanate, butyl titanate dimer, tetra (2-ethylhexyl) titanate, tetramethyl titanate, Examples include titanium acetylacetonate, titanium tetraacetylacetonate, titanium ethyl acetoacetate, titanium octanediolate, titanium lactate, titanium triethanolamate, polyhydroxytitanium stearate and the like.

  Here, FIG. 5 is a schematic view showing an example of a glass substrate surface modification apparatus. In the surface modification apparatus of FIG. 5, the container 9 is manufactured by airtightly combining flat plates such as acrylic resin plates and is filled with nitrogen gas. An open / close cover (not shown) for loading / unloading the glass substrate 1 is provided on the top of the container. In addition, a sealing port 12 for sealing nitrogen gas and vapor gas 11 of the adhesive agent is formed in the upper part of the side wall of the container 9, and gas and impurities in the container 9 are placed outside the container 9 in the lower part of the side wall of the container 9. An exhaust port (connected to a discharge duct 14 (not shown)) 13 is formed. A hot plate 10 for heating the glass substrate 1 is installed in the apparatus.

-Cooling of surface-modified glass substrate-
When a photoresist material for forming the photoresist layer 2 is applied on the surface of the glass substrate 1, the glass substrate is formed in order to easily control the thickness of the formed photoresist layer 2 and to improve the in-plane uniformity. The surface temperature of 1 is generally set to a temperature at which the photoresist material can be applied, that is, approximately equal to room temperature in the coating environment (specifically, 20 ° C. to 25 ° C.).
Here, the cooling of the glass substrate 1 is preferably performed in the container 9. That is, in the present invention, as described above, when the adhesive is applied to the surface of the glass substrate 1, it is heated by the hot plate 10. When the surface temperature of the heated glass substrate 1 is cooled to a temperature at which the photoresist material can be applied, the glass substrate 1 is left in the air, for example, in the atmosphere under the same clean environment as the environment where the photoresist material is applied. Attempting to lower the surface temperature in the case of a small amount of impurities contained in the atmosphere adheres to the surface of the glass substrate 1 and causes defects when it is stamped through the exposure process, development process, electroforming process, etc. Become. In addition, since a large amount of moisture is contained in the atmosphere, the surface of the glass substrate 1 that has been surface-modified by the application of the adhesive is hydrophilized again so that the surface of the glass substrate 1 and the photoresist material are in close contact with each other. Power will be reduced. In particular, quartz polishing glass with low surface roughness and high smoothness has a higher hygroscopicity than blue plate glass (soda lime glass), and thus has a remarkable decrease in adhesion, and an optical recording medium on which a photoresist layer 2 is laminated. Even if the unexposed master 8 is used, the pattern is completely washed away by development after pattern exposure.

Therefore, in the present invention, by cooling to a temperature at which the photoresist material can be applied in the container 9, the adhesion between the surface of the glass substrate 1 and the photoresist material does not decrease, and the optical recording medium has few defects. The stamper 81 can be manufactured. The inside of the container 9 is preferably replaced with a nitrogen atmosphere.
As a method for cooling the glass substrate 1, for example, heating of the hot plate 10 may be stopped. In order to shorten the cooling time, cooling means may be provided in the same container 9, and in this case, heating and cooling may be performed by a single means. Furthermore, in order to further shorten the cooling time, the container 9 used when applying the adhesive to the surface of the glass substrate 1 is quickly transferred to another container (similarly filled with a dry atmosphere). The glass substrate 1 surface temperature may be lowered to a temperature at which the photoresist material can be applied in the container. This case is also effective because the atmosphere and the amount of moisture that are in contact at the time of transfer are very small, and there is almost no influence on the adhesion and defects between the surface of the glass substrate 1 and the photoresist material.

When the surface temperature of the glass substrate 1 is cooled to a temperature at which a photoresist material can be applied, it is preferable to have a cooling means in the transferred container. As a result, the surface temperature of the glass substrate 1 can be lowered more quickly to a temperature at which the photoresist material can be applied, which is effective in improving the efficiency of the process.
In the case of cooling in the same container 9 as when the adhesive is applied to the surface of the glass substrate 1, it is necessary to first stop the heating of the hot plate 10 that has heated the glass substrate 1 up to the room temperature level. It takes a long time to lower the temperature in the container 9. On the other hand, in the case where the glass substrate 1 is quickly transferred into a container different from that used when applying the adhesive, the glass substrate 1 to be sealed is hot even if the inside of the container 9 is at room temperature level. Therefore, it still takes time to lower the surface temperature of the glass substrate 1 to a temperature at which the photoresist material can be applied. In addition, although it is possible to load another glass substrate on the back surface of the glass substrate 1 and promote the temperature decrease on the surface of the glass substrate 1 by heat exchange between the glass substrates, particles are generated by contact between the glass substrates. Therefore, there is a possibility that defects at the time of forming a stamper may increase due to the transfer to the surface side.
Therefore, in the present invention, since the container has cooling means capable of cooling the surface temperature of the glass substrate 1 to a temperature at which the photoresist material can be applied, the temperature in the container can also be lowered, and the glass in the container can be reduced. The time required for lowering the surface temperature of the substrate 1 is shortened, and the production efficiency can be improved.

Here, FIG. 9 is a diagram showing an example of a cooling device having the container 17 provided with the cooling means 18 for cooling the glass substrate 21. The container 17 of the cooling device is made by airtightly combining flat plates such as an acrylic plate, like the container 9 shown in FIG. The container 17 includes an open / close cover for loading / unloading the glass substrate 21 whose surface has been modified with an adhesive, an enclosure tube 22 for enclosing the nitrogen gas 23, and a cooling means 18 for cooling the inside of the container. ing. The cooling means 18 is composed of a Peltier element and has a metal tray 19 (cooling unit) that cools the glass substrate 21 at a low temperature. Further, the apparatus includes a glass substrate installation jig. In FIG. 9, 24 supplied to the cooling means 18 represents a water flow or an electric current.
The cooling means 18 is not particularly limited, and means having various forms of cooling functions can be used. For example, a simple Peltier element capable of realizing a low temperature with a water flow or current is preferable. It is preferable that the water flow rate and the amount of current used in the Peltier element are determined in consideration of cooling strength and uniformity.

  Installing the glass substrate in a non-contact state with the metal tray 19 of the cooling means 18 provided in the container 17 when the surface temperature of the glass substrate 21 is lowered to a temperature at which a photoresist material can be applied; This is effective in stabilizing the thickness of the photoresist layer, preventing defects during stamping, and preventing a decrease in adhesion between the surface of the glass substrate 21 and the photoresist material.

When the glass substrate 21 is directly placed on the metal tray 19 and cooled, the temperature of the glass substrate 21 can be lowered more quickly to a temperature at which the photoresist material can be applied, but the temperature is lowered too quickly because of the rapid cooling. As a result, the surface temperature of the glass substrate 21 is too low, and the thickness of the photoresist layer when the photoresist material is applied becomes thin, making it impossible to obtain a desired thickness. In addition, since the glass substrate 21 that has been rapidly cooled and the surface temperature has decreased too much is likely to cause dew condensation when it is transferred from the container 17 to an apparatus for applying a photoresist material, Impurities are likely to adhere. As a result, the surface of the glass substrate 21 to which the adhesion agent has been applied is re-modified to hydrophilicity, so that the adhesion with the photoresist material is reduced, or the occurrence of defects during stamping increases.
Therefore, as shown in FIG. 9, for example, a Teflon (registered trademark) processed jig 20 is placed on a metal tray 19, and a glass substrate 21 is set so as to support an edge on the jig 20. The contact area of the substrate 21 can be made as small as possible, and generation of particles due to contact can be suppressed. At the same time, since the cooling of the glass substrate 21 by the cooling means 18 is indirect cooling, not only the surface of the glass substrate 21 is rapidly cooled, the control of the thickness of the photoresist layer is facilitated, but also the application environment of the photoresist material is improved. It is also possible to prevent the occurrence of condensation when the glass substrate is moved.

<Surface modifying device for glass substrate used for unexposed master for optical recording medium>
The glass substrate surface modifying apparatus used for the unexposed master for optical recording media of the present invention is filled with a dry atmosphere and contains a glass substrate,
Heating means for heating the glass substrate accommodated therein;
In the said container, the provision means which provides the contact | adherence agent which modifies the surface to the surface of the said heated glass substrate is provided, and also another means is further provided as needed.
In this case, it is preferable that the container further includes a supply / exhaust means for supplying and exhausting dry air.
Examples of the other means include control means. The control means is not particularly limited as long as the movement of each means can be controlled, and can be appropriately selected according to the purpose. Examples thereof include devices such as a sequencer and a computer.
The details of the container, the heating means, the applying means, and the air supply / exhaust means are as described above.
According to the glass substrate surface modification apparatus, even when there is a large amount of moisture remaining on the glass substrate surface, the adhesion between the photoresist material and the glass substrate surface can be improved, and the existing simple structure apparatus can be used. A photoresist layer can be laminated on the surface of the glass substrate.

<Surface modification system for glass substrate used for unexposed master for optical recording medium>
The glass substrate surface modification system used for the unexposed master for optical recording media of the present invention comprises the glass substrate surface modification device of the present invention,
A container containing the glass substrate filled with a dry atmosphere and surface-modified;
A cooling device provided with a cooling means for cooling the glass substrate accommodated therein, and further having other configurations as necessary.
In this case, the cooling means has a low temperature part that cools the glass substrate at a low temperature, and the cooling device has a back surface of the glass substrate such that a gap exists between the low temperature part and the glass substrate. It is preferable to further include a jig that supports the glass substrate in a partially contacted state.
The details of the glass substrate surface modification device, the container, the cooling device, and the jig are as described above.

(Unexposed master for optical recording media)
The unexposed master for optical recording media of the present invention has a photoresist layer on the surface of a glass substrate used for the unexposed master for optical recording media surface-modified by the surface modification method of the present invention.

  Here, FIG. 4 is a schematic cross-sectional view showing an example of an unexposed master for an optical recording medium having a photoresist layer on the surface of the glass substrate surface-modified by the glass substrate surface modification method of the present invention. . The optical recording medium unexposed master 8 shown in FIG. 4 has a photoresist layer 2 laminated on a surface-modified glass substrate 21 (glass substrate used for the optical recording medium unexposed master).

The photoresist material used in the photoresist layer is preferably a positive type. The positive photoresist material is not particularly limited and may be appropriately selected depending on the intended purpose. However, a material obtained by dissolving a solid component such as a photosensitive material or a novolak resin in an alkyl or acetate solvent is preferable. It is.
The latent image portion exposed by laser light irradiation in the photoresist layer becomes soluble in an alkaline aqueous solution. Since the stock solution of the photoresist material has a high viscosity or a high concentration, it is usually preferable to use the photoresist material stock solution after diluting the stock solution of the photoresist material with the solvent or the like when producing an unexposed master for optical recording media.

-Formation of photoresist layer-
A photoresist layer is formed on a glass substrate whose surface temperature has been lowered to a temperature at which a photoresist material can be applied.
The photoresist layer is generally formed by, for example, applying a photoresist material by spin coating and pre-baking a glass substrate coated with the photoresist material. By heat-processing a glass substrate, the adhesive force of the glass substrate surface and a photoresist material can be improved compared with the time of non-processing. In particular, in quartz glass having low roughness and high smoothness, the adhesion is remarkably improved, and it is possible to prevent an exposure pattern from being destroyed and lost due to development after a latent image by laser light. In addition to improving the adhesion between the photoresist material and the glass substrate surface and preventing the occurrence of defects after the exposure process and the development process, it is also possible to apply the photo to the glass substrate surface with an existing simple structure device. By laminating the resist layer, an increase in cost can be suppressed.

Next, an example of the manufacturing method of the unexposed master for optical recording media using the glass substrate used for the unexposed master for optical recording media of the present invention will be described.
First, after polishing and washing a disk-shaped glass substrate, the surface of the glass substrate is hydrophobized by surface modification with an adhesive to improve paintability. That is, as shown in FIG. 3B, when HMDS is applied on the surface as an adhesive, water molecules on the surface of the glass substrate are hydrophobized by trimethylsilylation.
Next, a surface-modified glass substrate (a glass substrate used for an unexposed master for optical recording media) is placed on a turntable, and the photoresist is rotated by a dispenser of a spinner apparatus while rotating the glass substrate by rotating the turntable. Drip the material. After the photoresist material reaches the surface of the board, the dropping is finished, and the rotation speed of the turntable is made larger than that at the time of dropping, and the excess photoresist material is scattered outside the glass substrate by centrifugal force. . The thickness of the photoresist layer can be adjusted by adjusting the swing-off rotation speed when the photoresist material is scattered, and the rotation speed is set so as to obtain a desired thickness.
Next, the glass substrate coated with the photoresist material is pre-baked in an oven to obtain an unexposed master 8 for an optical recording medium having a photoresist layer formed thereon as shown in FIG. The optical recording medium exposure master 80 is obtained by exposing the unexposed master 8 for optical recording medium to pits and grooves by laser light with an exposure machine.

(Method for manufacturing master for optical recording medium)
The method for producing a master for an optical recording medium according to the present invention comprises the steps of exposing and developing the unexposed master for an optical recording medium according to the present invention, and using the concavo-convex pattern of the photoresist layer formed by the development as a mask. Etching is performed.

As the glass substrate, a quartz glass substrate is suitable.
The glass etching is not particularly limited and can be appropriately selected depending on the purpose. For example, wet etching, in which glass is impregnated with a solution of hydrofluoric acid or the like, and a pattern of accelerated ions on a glass substrate is used. For example, a dry etching method in which physical processing is performed by irradiating the substrate. Among these, the dry etching method is suitable for fine processing on the order of μm such as HD format and BD format.
Examples of the gas used in the etching step include halogenated methane gas such as O ₂ , Ar; CF ₄ , CHF ₃ , CCl ₄ , CHCl _{3, and the} like. Etching of the exposed surface of the developed master exposure pattern (corresponding to the groove), or etching the portion of the photoresist material (corresponding to the land) where the layer remains as a mask after development, used for each application By selecting the gas to be used, a desired master for an optical recording medium can be obtained.

Here, FIG. 10 is a process diagram showing an example of a method for producing an optical recording medium master according to the present invention.
As shown in FIG. 10A, first, a photoresist solution is applied onto a quartz substrate 100 by spin coating or the like to form a photoresist layer 101.
Next, as shown in FIG. 10B, while rotating the quartz substrate 100, the groove pattern is exposed by laser light according to the BD format with a track pitch of 0.32 μm using an exposure apparatus. For the exposure, deep UV light having a wavelength of λ = 257 nm was used, and a groove (guide groove) was continuously exposed with an equal amount of light in a region of a radial position of 22 mm to 59 mm from the inner peripheral side to form a latent image.
Next, as shown in FIG. 10C, the photoresist layer 101 is developed, and a desired concavo-convex pattern is formed by the photoresist layer 101 remaining after removing the exposed portion.
Next, as shown in FIG. 10D, the concavo-convex pattern of the formed photoresist layer 101 is used as a mask, selective etching is performed by RIE (Reactive Ion Etching) or the like, and the concavo-convex pattern is formed on the quartz substrate 100. Form a pattern. That is, the glass exposed surface corresponding to the groove (arrow portion C in FIG. 10) is etched.
Next, as shown in FIG. 10E, the remaining photoresist layer 101 corresponding to the land (arrow part D in FIG. 10) is removed, and an optical recording medium master 102 having an uneven shape can be produced.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

Example 1
A disc-shaped glass substrate having a diameter of 200 mm and a thickness of 6 mm is polished and washed with high-pressure water, and then the polished surface of the glass substrate (the side on which the photoresist layer is laminated) is used as hexamethylene disilazane (HMDS) as an adhesive. Hydrophobized by trimethylsilylation treatment with Tokyo Ohka Kogyo Co., Ltd. (OAP). As a glass substrate, a quartz glass substrate was used for groove formation by subsequent BD pattern exposure and glass etching.
Specifically, the quartz glass substrate 1 is placed on the hot plate 10 in the container 9 shown in FIG. 5 with the polishing surface facing upward, and nitrogen gas is sealed and exhausted at 70 ° C. for 10 minutes. While heating. Exhaust was stopped after 10 minutes from the start of installation, nitrogen gas was then sealed in the container, and the interior of the container was completely purged with nitrogen gas, and then the inside of the pressurized tank 16 shown in FIG. A pressurized HMDS vapor gas was sealed for 90 seconds, and the quartz glass substrate was surface-modified. Thus, a glass substrate used for the unexposed master for optical recording medium of Example 1 was produced.

  Next, after the surface temperature of the quartz glass substrate subjected to the surface modification treatment in the container 9 shown in FIG. 5 is lowered to 23 ° C., the quartz glass substrate is placed on the turntable of the spinner apparatus, and the glass substrate is rotated by rotating the turntable. Then, a photoresist material (manufactured by AZ Electronic Materials, diluted with AZ HDDVD stock solution with a solvent) was applied by a dispenser of a spinner apparatus. Immediately after the completion of the discharge, the number of rotations of the turntable was further increased, and the excess photoresist material remaining on the glass substrate was scattered outward. Next, the quartz glass substrate coated with the photoresist material was pre-baked in an oven at 110 ° C. for 30 minutes to form a photoresist layer having a thickness of 23 nm (230 mm). Thus, an unexposed master disk for optical recording medium of Example 1 was produced.

(Example 2)
In Example 1, the quartz glass substrate 1 was placed on the hot plate 10 in the container 9 shown in FIG. 5 with the polishing surface facing upward, and nitrogen gas was sealed and exhausted at 75 ° C. for 10 minutes. A glass substrate used for the unexposed master for optical recording medium of Example 2 and an unexposed master for optical recording medium were prepared in the same manner as in Example 1 except that heating was performed.

(Example 3)
In Example 1, the quartz glass substrate 1 was placed on the hot plate 10 in the container 9 shown in FIG. 5 with the polishing surface facing upward, and nitrogen gas was sealed and exhausted at 80 ° C. for 10 minutes. A glass substrate used for the unexposed master for the optical recording medium of Example 3 and an unexposed master for the optical recording medium were produced in the same manner as in Example 1 except for heating.

Example 4
In Example 1, the quartz glass substrate 1 was placed on the hot plate 10 in the container 9 shown in FIG. 5 with the polishing surface facing upward, and nitrogen gas was sealed and exhausted at 65 ° C. for 10 minutes. A glass substrate used for the unexposed master for optical recording medium of Example 4 and an unexposed master for optical recording medium were produced in the same manner as in Example 1 except that heating was performed.

(Comparative Example 1)
In Example 1, the quartz glass substrate 1 was placed on the hot plate 10 in the container 9 shown in FIG. 5 with the polishing surface facing upward, and was not heated, and was the same as Example 1 except that it was not heated. The glass substrate used for the unexposed master for optical recording media of Comparative Example 1 and the unexposed master for optical recording media were produced.

(Comparative Example 2)
In Example 1, the quartz glass substrate 1 heated while filling and exhausting nitrogen gas at 80 ° C. in the container 9 shown in FIG. 5 was applied with liquid HMDS by spin coating in the atmosphere outside the container. Except for the above, a glass substrate used for the unexposed master for optical recording medium of Comparative Example 2 and an unexposed master for optical recording medium were produced in the same manner as in Example 1.

  Next, the produced unexposed masters for optical recording media of Examples 1 to 4 and Comparative Examples 1 to 2 are BD having a track pitch of 0.32 μm by laser light using an exposure apparatus as shown in FIG. The groove pattern was exposed according to the format. For the exposure, deep UV light having a wavelength of λ = 257 nm was used, and a groove (guide groove) was continuously exposed with an equal amount of light in a region of a radial position of 22 mm to 59 mm from the inner peripheral side to form a latent image. After the latent image, the groove was patterned by development with a 50% by weight diluted developer, and finally post-baked at 130 ° C. for 30 minutes to produce a groove region on the entire exposure master for optical recording media.

<Evaluation>
About each of the obtained exposure masters for optical recording media of Examples 1 to 4 and Comparative Examples 1 and 2, a cold lamp was irradiated and observed with the naked eye. Examples 1 to 4 were respectively exposed groove patterns. Was formed on the surface of the glass substrate.
On the other hand, the exposure pattern was not seen by the comparative example 1 on the glass substrate surface. That is, the photoresist layer formed on the unexposed master for optical recording medium was completely discharged by development. In Comparative Example 2, a large amount of spotted defects were observed on the surface of the exposure master for optical recording media.

Next, the groove pattern of the exposure master for optical recording media of Examples 1 and 4 was observed with an atomic force microscope (AFM; manufactured by Nanoscope IIIa, Digital Instruments). As shown in FIG. 7, a groove having a half width of 165 nm was formed on the exposure master for optical recording medium of Example 1. On the other hand, in the exposure master for optical recording medium of Example 4, as shown in FIG. 8, a groove pattern with slightly varying half widths was formed. That is, in Example 4, the adhesion of the photoresist layer to the glass substrate surface is slightly weaker than that in Example 1, and the so-called pattern in which the land moves by development and the groove width varies by contacting the adjacent land. Although collapse occurred, it was at a level without any problem.
From the above results, the unexposed master disc for optical recording media produced by the processes of Examples 1 to 4, particularly Examples 1 to 3, ensures the adhesion between the photoresist material and the glass substrate, and has few defects. It was found that an exposure master for an optical recording medium capable of obtaining a stamper was obtained.

(Example 5)
A disc-shaped glass substrate having a diameter of 200 mm and a thickness of 6 mm is polished and washed with high-pressure water, and then the polished surface of the glass substrate (the side on which the photoresist layer is laminated) is used as hexamethylene disilazane (HMDS) as an adhesive. Hydrophobized by trimethylsilylation treatment using OAP), manufactured by Tokyo Ohka Kogyo Co., Ltd. As a glass substrate, a quartz glass substrate was used for groove formation by subsequent BD pattern exposure and glass etching.
Specifically, the quartz glass substrate 1 is placed on the hot plate 10 in the container 9 shown in FIG. 5 with the polishing surface facing upward, and nitrogen gas is sealed and exhausted at 80 ° C. for 10 minutes. Heated. After 10 minutes from the start of installation, after exhausting was stopped, nitrogen gas was sealed in the apparatus, and after the inside of the container was completely purged with nitrogen, it was added from the sealing port 12 in a tank as shown in FIG. The pressurized HMDS vapor gas was sealed for 90 seconds, and the quartz glass substrate was surface-modified.

  Next, the surface-modified quartz glass substrate 21 was immediately set in another container 17 provided with a cooling means using a Peltier element as shown in FIG. 9, and the surface temperature was lowered while purging nitrogen gas. . That is, at room temperature without starting the cooling means, the edge of the quartz glass substrate is placed on a Teflon (registered trademark) jig on a metal tray in which the quartz glass substrate is placed on an aluminum plate (thickness 6 mm) integrated with the cooling means. By mounting together, the quartz glass substrate was indirectly cooled until the surface temperature reached 23 ° C. Thus, a glass substrate used for the unexposed master for optical recording medium of Example 5 was produced.

  Next, after the surface temperature of the quartz glass substrate is lowered to 23 ° C., the quartz glass substrate is placed on a turntable of the spinner apparatus, and a photoresist layer is formed by a dispenser of the spinner apparatus while rotating the quartz glass substrate by the turntable. Photoresist material (manufactured by Tokyo Ohka Kogyo Co., Ltd., THMR-iP3300 stock solution diluted with a solvent) was applied. Immediately after the completion of the discharge, the number of rotations of the turntable was further increased, and the excess photoresist material remaining on the glass substrate was scattered outward. The quartz glass substrate coated with this photoresist material was pre-baked at 110 ° C. for 30 minutes in an oven to form a photoresist layer having a thickness of 23 nm (230 mm). Thus, an unexposed master disk for optical recording media of Example 5 was produced.

(Example 6)
In Example 5, the glass substrate 21 subjected to the surface modification treatment with the cooling water flow rate of 0.3 l / min and the current amount of 3 A was activated, and the surface-treated glass substrate 21 was an aluminum plate (thickness 6 mm) integrated with the cooling means. Except that the glass substrate was indirectly cooled until the surface temperature reached 23 ° C. by placing the edge of the glass substrate 21 on the Teflon (registered trademark) jig 20 on the metal tray 19 installed in the embodiment. In the same manner as in Example 5, an unexposed master for an optical recording medium of Example 6 was produced.

(Example 7)
In Example 5, it was taken out from the container 17 immediately after the HMDS vapor gas was applied to the surface of the glass substrate, and it was carried out in the room air except that the surface temperature of the glass substrate 21 subjected to the surface modification was 23 ° C. In the same manner as in Example 5, an unexposed master for optical recording medium of Example 7 was produced.

(Example 8)
In Example 5, the glass substrate 21 after the surface modification treatment was directly placed on the aluminum plate 18 with a cooling means in FIG. 9 until the surface temperature of the glass substrate 21 reached 23 ° C. while purging nitrogen gas. An unexposed master for an optical recording medium of Example 8 was produced in the same manner as Example 5 except that it was cooled.

  The unexposed master discs for optical recording media of Examples 5 to 8 manufactured as described above were subjected to a BD format with a track pitch of 0.32 μm using a laser beam having a wavelength λ = 257 nm using an exposure apparatus as shown in FIG. Accordingly, the groove pattern was exposed to a region having a radial position of 22 mm to 59 mm from the inner peripheral side to form a latent image. After the exposure, the groove was patterned by development with a 50% by weight diluted developer, and finally post-baked at 130 ° C. for 30 minutes to produce a groove region on the entire surface of the exposure master for optical recording media.

<Evaluation>
The obtained exposure masters for optical recording media of Examples 5 to 8 were irradiated with a cold lamp and visually observed. As a result, in Example 7, the exposure pattern on the glass substrate surface was somewhat disturbed. That is, the photoresist layer formed on the glass substrate used for the unexposed master for the optical recording medium was slightly leaked by development, but it was at a level with no problem.
Moreover, in Example 8, although the groove pattern was formed in the glass substrate surface, the spotted defect was seen a little on the exposure surface. This is because the master of Example 8 applies the HMDS vapor gas on the glass substrate while heating the glass substrate in a container as shown in FIG. Since the aluminum plate-equipped cooling means 18 provided in the container 17 shown in FIG. 9 is directly installed and rapidly cooled, dew condensation occurs immediately after the transfer to the apparatus for applying the photoresist material, and fine particles due to this dew adhere, This is probably because a defect has occurred. However, this spot-like defect was at a level without any problem.

In Examples 5 and 6, the groove pattern was well formed on the surface of the glass substrate.
The HMDS vapor gas is applied on the glass substrate while heating the glass substrate in a container 9 as shown in FIG. 5, and then up to 23 ° C. where the photoresist material can be applied in the container 17 as shown in FIG. The time taken to lower the surface temperature of the glass substrate was 90 minutes in Example 5, and 27 minutes in Example 6. For this reason, as shown in FIG. 9, the cooling means 18 is provided in the container 17 sealed with nitrogen gas as shown in FIG. 9, and the glass substrate is installed in a non-contact state with the cooling means 18. Thus, it was found that the surface temperature of the glass substrate can be lowered more quickly to a temperature at which a photoresist material can be applied, and an unexposed master for an optical recording medium can be produced more efficiently than in Example 5.
Further, in Example 1, the glass substrate is applied while being heated in a container 9 as shown in FIG. 5, and then the surface temperature of the quartz glass substrate subjected to surface modification treatment in the container 9 is lowered to 23 ° C. It took 120 minutes. Thus, according to the glass substrate surface modification system according to the present embodiment, the time required for lowering the surface temperature of the glass substrate can be shortened.

  The glass substrate used for the unexposed master for optical recording medium and the unexposed master for optical recording medium surface-modified by the surface modification method of the present invention are used for the production of a stamper for optical recording medium, and particularly a large capacity HD. It is suitably used for optical recording media in the format and BD format.

FIG. 1 is a process diagram showing an example of a conventional stamper manufacturing method. FIG. 2 is a view showing an exposure apparatus that draws a latent image of a pattern on an unexposed master for optical recording media. FIG. 3A is a schematic diagram showing OH groups of water remaining on the glass substrate surface. FIG. 3B is a schematic diagram showing a state in which the OH group in FIG. 3A has been modified to a trimethylsilanol group by reacting with HMDS. FIG. 4 is a schematic view showing an example of an unexposed master for an optical recording medium of the present invention. FIG. 5 is a schematic view showing an example of a surface modification apparatus for hydrophobizing the glass substrate surface. FIG. 6 is a schematic diagram illustrating an example of a pressurized tank that releases vapor gas of the adhesive. FIG. 7 is a diagram showing a result of observing the groove pattern of the exposure master for the optical recording medium of Example 1 with an atomic force microscope. FIG. 8 is a diagram showing a result of observing the groove pattern of the optical recording medium exposure master of Example 4 with an atomic force microscope. FIG. 9 is a schematic view showing an example of a cooling device having a container provided with a cooling means for cooling the surface-modified glass substrate. FIG. 10 is a process diagram showing an example of a method for producing an optical recording medium master according to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Glass substrate 2 Photoresist layer 3 Metal board 4 Gas laser 5 Mirror 6 EOM (electro-optic modulator)
7 Lens 8 Unexposed master for optical recording medium 9 Container 10 Hot plate 11 Nitrogen gas or adhesive agent vapor gas 12 Filling port 13 Discharge port 14 Exhaust duct 15 Pressure tank 16 Adhesive liquid 17 Container 18 Cooling means 19 Metal tray 20 Glass Substrate installation jig 21 Surface-modified glass substrate (glass substrate used for unexposed master for optical recording media)
22 Nitrogen filling port 23 Nitrogen gas 24 Water flow or current 80 Exposure master for optical recording medium 81 Stamper for optical recording medium 90 Contact tube 91 Non-contact tube 100 Quartz substrate 101 Photoresist layer 102 Master for optical recording medium

Claims (13)

  A method for modifying a surface of a glass substrate used for an unexposed master for an optical recording medium, wherein the surface of the glass substrate is modified by heating the glass substrate in a dry atmosphere and applying an adhesive to the surface of the glass substrate.   The optical substrate for optical recording medium according to claim 1, wherein after applying the adhesive, the glass substrate is cooled in a dry atmosphere until the surface temperature of the glass substrate reaches a temperature at which a photoresist material can be applied to the glass substrate surface. A method for modifying the surface of a glass substrate used for an exposure master.   The method for modifying the surface of a glass substrate used for an unexposed master for an optical recording medium according to claim 1, wherein the glass substrate is a quartz glass substrate.   The method for surface modification of a glass substrate used for an unexposed master for an optical recording medium according to any one of claims 1 to 3, wherein the glass substrate is heated using a hot plate.   The method for modifying the surface of a glass substrate used for an unexposed master for an optical recording medium according to any one of claims 1 to 4, wherein the heating temperature of the glass substrate is 70 ° C or higher.   The method for modifying the surface of a glass substrate used for an unexposed master for an optical recording medium according to any one of claims 1 to 5, wherein the adhesion agent is at least one selected from a silazane compound and a silane coupling agent.   The method for modifying the surface of a glass substrate used for an unexposed master for an optical recording medium according to claim 6, wherein the silazane compound is hexamethylene disilazane (HMDS).   An unexposed master for an optical recording medium, comprising a photoresist layer on a surface of a glass substrate that has been surface-modified by the surface modification method according to claim 1.   9. A master for an optical recording medium, wherein the glass substrate is etched using an uneven pattern of a photoresist layer formed by exposing and developing the unexposed master for an optical recording medium according to claim 8 as a mask. Manufacturing method. A container filled with a dry atmosphere and containing a glass substrate;
Heating means for heating the glass substrate accommodated therein;
In the container, on the surface of the heated glass substrate, an applying means for applying an adhesive that modifies the surface;
An apparatus for modifying a surface of a glass substrate used for an unexposed master for an optical recording medium.   The apparatus for modifying a surface of a glass substrate for use in an unexposed master for an optical recording medium according to claim 10, further comprising air supply / exhaust means for supplying and exhausting dry air to and from the container. A surface modification apparatus for a glass substrate according to any one of claims 10 and 11,
A container containing the glass substrate filled with a dry atmosphere and surface-modified;
A glass substrate surface modification system for use in an unexposed master for an optical recording medium, comprising: a cooling device including a cooling means for cooling the glass substrate accommodated therein. The cooling means has a low temperature part that cools the glass substrate at a low temperature,
The cooling device according to claim 12, further comprising a jig that supports the glass substrate in a state of being in partial contact with the back surface of the glass substrate such that the low temperature portion and the glass substrate have a gap. A glass substrate surface modification system used for an unexposed master for optical recording media.