JPH06302017A - Production of stamper for optical recording medium and its master disk exposure device - Google Patents

Abstract

PURPOSE:To form high-accuracy rugged patterns by developing the exposed parts of a resist layer by a dry processing. CONSTITUTION:The shapes of the rugged patterns formed by the development by the wet processing are varied largely by a slight dispersion in developing conditions, such as temp. and concn. of a developer and a difference in the wettability of the developer with the surface of the resist layer in the case of this development. The development by the dry processing is executed in order to prevent these defects. The resist layer 2 is formed on a master disk 1 and the exposed parts 3 thereof are removed by exposing the layer 2 according to the prescribed information of the optical recording medium. The rugged patterns 4 meeting the prescribed information are formed by the development by the dry processing. The stamper 7 for the optical recording medium is produced in such a manner. A material contg. a compd. formed by acetylating or alkylating polyterminals as a chief material is used at the time of forming the resist layer. The resist layer is subjected to a heat treatment process then to the development by the dry processing to form the rugged patterns meeting the information of the optical recording medium. The stamper having the high performance and high quality is thus produced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to the recording of information using light,
The present invention relates to a method of manufacturing a stamper for an optical recording medium used for an optical recording medium for reproduction or erasing, and a master exposure apparatus for the same.

[0002]

2. Description of the Related Art Conventionally, in an optical recording medium for recording and reproducing information with a minute light spot, an information signal recording portion (pit) and guide grooves (grooves) for positioning the light spot are uneven. A general optical recording medium prerecorded as pattern information is manufactured by transferring the uneven surface to a polycarbonate resin, an acrylic resin or the like using a stamper having an uneven surface corresponding to the information. .

The most common conventional example of a method for manufacturing a stamper for an optical recording medium is a manufacturing method as shown in FIG.
That is, after the resist layer 9 shown in FIG. 2B is formed on the glass master 8 whose surface is mirror-polished as shown in FIG. 2A, the resist layer 9 shown in FIG. 2), the resist is exposed with a laser beam to form an exposed portion (latent image) 10, and then the exposed portion 10 is dissolved and removed by wet development with an alkali developing solution.
As shown in (d), the concavo-convex pattern 11 is exposed. After that, as shown in FIG.
A metal is formed on the surface of the substrate by means of vacuum film forming or the like to form a conductor film 12, thereby becoming a conductor, and nickel or the like is electroformed by using the conductor film 12 as an electrode as shown in FIG. 2 (f). Then, the electroformed layer 13 was formed, and the stamper 14 was produced by peeling the electroformed layer 13 from the glass master.

The composition of the positive resist used in the manufacturing process of the stamper for an optical recording medium is generally composed of a naphthoquinonediazide type photosensitizer, a novolak resin type base resin (base material), a solvent and the like. In this type of resist, the alkali-insoluble naphthoquinonediazide suppresses the alkali-solubility of the alkali-soluble novolak resin. Naphthoquinonediazide not only decomposes itself by light irradiation to become an alkali-soluble indenecarboxylic acid, but also promotes the alkali solubility of the novolak resin. Therefore, when a resist of such a system is applied in a film form and exposed according to predetermined information, there is a difference in solubility between the exposed portion and the unexposed portion in the alkaline aqueous solution. By developing under the conditions, it becomes possible to selectively dissolve and remove the exposed portion to form an uneven pattern.

The master exposure apparatus used in the manufacturing process of the stamper for the optical recording medium as described above is generally shown in FIG.
The configuration is as shown in. Reference numeral 15 is a master, 16 is a jig for fixing the master, 17 is a turntable, 18 is a spindle motor, 19 is a laser light source for exposure, 20 is a fixed optical system, 21 is an optical head driving device, 22 is a moving optical system,
Reference numeral 23 is an optical head, 24 is an objective lens, and 25 is a vibration isolation table. With this apparatus, the master 23 having the resist layer formed on the upper surface by the above-described method is set so that the resist layer is on the upper side as shown in FIG. 3, and the master 15 is rotated and the predetermined information of the optical recording medium is read according to the information. Exposure was performed by irradiating a laser beam.

[0006]

In recent years, optical recording media are required to have stampers having various concave-convex pattern shapes due to increase in types of patterns and increase in density of patterns for increasing recording capacity. Came.

However, in the above-mentioned prior art, the shape of the uneven pattern formed is small due to slight variations in various developing conditions such as temperature and concentration of the developing solution and difference in wetting property of the developing solution to the resist layer surface. It fluctuates significantly. In addition, since there is a time lag within the master in the diffusion of the developing solution on the resist layer surface when starting development and the diffusion of the washing solution when developing on the resist layer surface, there is variation in the progress of development within the same resist surface. Occurs. When manufacturing a highly accurate uneven pattern, there is a problem that a desired uneven pattern cannot be accurately obtained for the above reasons.

Further, in the developing process, the developing solution or the washing solution scattered in the developing device adheres to the surface of the resist layer, causing spots or defects on the surface of the resist layer, which are directly transferred to the finished stamper. There is a problem that it is transferred, which causes an increase in the error rate of recorded information on the stamper and a defective appearance.

Further, in the above-mentioned prior art, since the exposure process and the development process are independent, a dedicated device is required for each process, the equipment cost is high, the installation space is large, and the work efficiency is high. It has the problem of being bad.

Therefore, the present invention solves such a problem, and an object thereof is to make it possible to form a concavo-convex pattern with high accuracy without requiring a developing process using a developing solution. Another object of the present invention is to provide a method of manufacturing a stamper for a high-performance and high-quality optical recording medium, in which there are few defects that cause recording information reproduction and defects in appearance.

Further, in order to carry out with low equipment cost, space saving, and high work efficiency, the exposure and development steps required for forming the concavo-convex pattern can be simultaneously performed, and a method for producing the stamper for optical recording medium and the production thereof. It is in the area of providing equipment.

[0012]

In order to solve such a problem, a method of manufacturing a stamper for an optical recording medium according to the present invention comprises a step of forming a positive type resist layer on a master and a step of forming the resist layer. Optical recording having a step of exposing according to predetermined information of the optical recording medium and a developing step of removing the above-mentioned exposed portion of the resist layer to form an uneven pattern corresponding to the predetermined information of the optical recording medium. In the method of manufacturing a medium stamper, the above-mentioned development step is performed by dry development.

As means for enabling the formation of the concavo-convex pattern by such dry development, the main material (base material) constituting the above substance is depolymerized and decomposed by the action of the photosensitive group contained in the substance. It is conceivable that a substance having a system in which the exposed portion is vaporized at a lower temperature than that of the unexposed portion by making the molecular weight low is used in the formation of the resist layer.

As a substance having such characteristics, for example, a system in which a polymer which is easily depolymerized in the presence of an acid to be a monomer is used as a base material and a photo-acid generator is added thereto can be used. Specifically as the base material,

[0015]

[Chemical 1]

Poly (o-phthalaldehyde) represented by
A compound in which the terminal is acetylated or alkylated is considered (R1 represents an acetyl group having 2 to 11 carbon atoms, and R2 represents an alkyl group having 2 to 10 carbon atoms). This compound in the presence of acid

[0017]

[Chemical 2]

As shown in (3), it is easily depolymerized at room temperature.
-Becomes phthalaldehyde and vaporizes at a lower temperature than the polymer before depolymerization. When a substance of such a system is formed into a thin film and exposed to light, the acid generated from the photo-acid generator causes depolymerization of the substrate to generate o-phthalaldehyde, and the substrate is not decomposed to such an extent. When heat treatment is performed under appropriate conditions, only the exposed portion is selectively vaporized and removed to form an uneven pattern.

Therefore, according to the method for manufacturing a stamper for an optical recording medium of the present invention, when forming the resist layer described above, poly (o)
-A phthalaldehyde) terminally acetylated or alkylated compound is used as a main material, and a heat treatment step is performed as a means of the above-mentioned dry development, whereby an uneven pattern corresponding to the information of the above-mentioned optical recording medium is obtained. Are sequentially formed.

Further, a step of forming a positive type resist layer on the master, a step of exposing the resist layer according to predetermined information of the optical recording medium, and a heat treatment of the above-mentioned exposed portion of the resist layer. In a method of manufacturing an optical recording medium stamper having a developing step of removing and forming a concave-convex pattern corresponding to predetermined information of the optical recording medium, the heat treatment is sequentially performed according to the information of the optical recording medium. If it is performed during the exposure process, it is possible to form the uneven pattern corresponding to the information of the optical recording medium described above during the exposure process without making the developing process independent.

Therefore, the method of manufacturing the stamper for an optical recording medium of the present invention is characterized in that it is carried out by the following method.

First, the development process by the above-mentioned heat treatment is not independent, and after the above-mentioned entire resist layer is preheated to a predetermined temperature during the above-mentioned exposure process, this whole resist layer is brought to this temperature. In the held state, exposure is performed according to predetermined information of the above-mentioned optical recording medium, and a concavo-convex pattern according to information of the above-mentioned optical recording medium is sequentially formed.

Secondly, the development process by the above-mentioned heat treatment is not independent, and the process of exposing the above-mentioned resist layer according to the predetermined information of the above-mentioned optical recording medium during the above-mentioned exposure process. Then, the exposed portion sequentially formed by the above-mentioned exposure is locally heated by light having a wavelength that does not affect the photosensitivity of the resist layer, and the uneven pattern corresponding to the information on the optical recording medium is obtained. Are sequentially formed.

Further, in the master exposure apparatus of the present invention, a master having a resist layer formed on its upper surface is fixed to a turntable,
In a master exposure apparatus that performs exposure according to predetermined information of an optical recording medium with a laser beam while rotating this master, the above-mentioned master is heated on the above turntable as a means for heating the entire resist layer. It is characterized by having a heater.

Further, in another master exposure apparatus of the present invention, a master having a resist layer formed on its upper surface is fixed to a turntable, and while the master is rotated, a predetermined amount of information is recorded on the optical recording medium by a laser beam. In a master exposure apparatus that performs exposure by means of exposure, as a means for locally heating the resist layer, at least a light source that does not affect the photosensitivity of the resist layer and an objective lens are provided.

[0026]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 is a conceptual diagram showing a method of manufacturing a stamper for an optical recording medium of the present invention.

Specifically, it is manufactured as follows.

The surface of the glass master 1 shown in FIG. 1 (a) is mirror-polished and then washed, and the surface is well dried. Then, in order to improve the adhesion to the resist, silane coupling is performed. Agents such as hexamethyldisilazane (HMD
Treat the surface with S). By applying a resist on this glass master by a spin coating method, as shown in FIG.
After forming the resist layer 2 as shown in FIG.
The solvent inside the resist layer is removed by performing pre-baking at about 100 to 100 ° C. In addition to this, a dip method, a curtain coating method, or the like can be used as a method of forming the resist layer.

Here, the substances used for forming the resist layer 2 will be described. The resist layer 2 described above
As the substance used for forming the compound, a compound having a structure represented by Chemical formula 1 as a main material and a substance composed of a photo-acid generator and an organic solvent is used.

As the photo-acid generator,

[0032]

[Chemical 3]

Triphenylsulfonium salts as shown in

[0034]

[Chemical 4]

Diphenyliodonium salts as shown in

[0036]

[Chemical 5]

Phenyldiazonium salts as shown in

[0038]

[Chemical 6]

2,6-dinitrobenzyl tosylate as shown in

[0040]

[Chemical 7]

P-nitrobenzyl-9, as shown in
10-diethoxyanthracene-2-sulfonates,

[0042]

[Chemical 8]

2- (4-methoxyphenyl) -4,6-di (trichloromethyl) triazines as shown in

[0044]

[Chemical 9]

O-naphthoquinonediazide-4-sulfonic acid esters as shown in

[0046]

[Chemical 10]

It is desirable that o-naphthoquinonediazide-5-sulfonic acid esters such as those shown in can be used and that they have high sensitivity at the wavelength of the light source used for exposure. If necessary, a spectral sensitizer may be added. You can go.

As the solvent, a cellosolve acetate-based solvent was used as the main solvent, and xylene and butyl acetate were added thereto in several tens of percent, but the solvent is not limited to this. .

The above-mentioned resist layer 2 formed by using such a substance is exposed according to predetermined information of the optical recording medium to form an exposed portion 3 as shown in FIG. 1 (c). The exposure is performed using laser light while rotating the master.

Then, as a dry development process, the master 1 is heated on a hot plate at a temperature of about 80 ° C. to 130 ° C. to vaporize and remove the exposed portion 3 on the resist layer 2. As shown in FIG. 5, the uneven pattern 4 is formed on the resist layer 2. As the heat treatment method,
The same effect can be obtained by using a heating furnace.

Next, as shown in FIG. 1E, nickel is deposited on the surface of the resist layer 2 by a vacuum deposition method to a thickness of about 500 to 1000 Å to form a conductor film 5.
Vacuum deposition methods include vapor deposition, sputtering, CVD,
There are ion plating and the like, and the same effect can be obtained in each case. Further, as a method of forming the conductor film 5, the same effect can be obtained by an electroless plating method other than the vacuum film forming method.

Then, nickel is electroformed by using the conductor film 5 as an electrode to form an electroformed layer 6 of about 0.2 to 0.3 mm. This is separated from the master 1, the back surface is polished, the inner and outer diameters are processed by punching, and further washed to form the stamper 7.

The resulting stamper for an optical recording medium has an uneven pattern formed with high accuracy, and a stain or a defect generated on the surface of the resist layer in the developing process is recorded on the stamper for an optical recording medium by recording. There were no defects or appearance defects that could cause information reproduction.

(Embodiment 2) The development for removing the exposed portion by the heat treatment described in Embodiment 1 to form an uneven pattern is as follows.
It may be performed in the process of sequentially exposing according to the information of the optical recording medium. Specifically, the following method is used.

First, as a method of the above-mentioned heat treatment, after heating the entire resist layer in advance to a predetermined temperature, the predetermined temperature of the optical recording medium is maintained in the state where the entire resist layer is kept at this temperature. Exposure is performed according to information, and a concavo-convex pattern corresponding to information on the optical recording medium is sequentially formed. Figure 4
FIG. 3A is a conceptual diagram of a master exposure apparatus of the present invention used when forming a concavo-convex pattern by such a method.
26 is a heater, 27 is a master, 28 is a jig for fixing the master,
29 is a turntable, 30 is a spindle motor, 31
Is a laser light source for exposure, 32 is a fixed optical system, 33 is an optical head driving device, 34 is a moving optical system, 35 is an optical head, 36 is an exposure objective lens, and 37 is a vibration isolation table. In the apparatus shown in FIG. 4A, the master 27 having the resist layer formed on the upper surface by the method described in the first embodiment is fixed with the resist surface facing upward on the turntable 29 using the master fixing jig 28. To do. Next, the heater 26 is operated to heat it to a predetermined temperature. After confirming that the temperature of the master is stable, the master 27 is rotated to start exposure according to the information on the optical recording medium. Then, as shown in FIG. 6, when the resist layer 51 is exposed to light, the resist layer 51 immediately starts to vaporize, and an uneven pattern 54 is formed.

Secondly, as a method of the above-mentioned heat treatment, in the process of exposing the above-mentioned resist layer in accordance with predetermined information of the above-mentioned optical recording medium, an exposure portion sequentially formed by this exposure. Is locally heated by light having a wavelength that does not affect the photosensitivity of the resist layer to sequentially form a concavo-convex pattern corresponding to the information on the optical recording medium. here,
Light having a wavelength that does not affect the photosensitivity of the resist layer is as described above.

[0057]

[Chemical 11]

Light of a wavelength range in which the reaction of (2) above does not substantially occur, and specifically, a wavelength of 600 nm or more is desirable. FIG. 5A is a conceptual diagram of another master exposure apparatus of the present invention used when forming a concavo-convex pattern by such a method. 27 is a master, 28 is a jig for fixing the master,
29 is a turntable, 30 is a spindle motor, 31
Is a laser light source for exposure, 32 is a fixed optical system, 33 is an optical head driving device, 34 is a moving optical system, 35 is an optical head, 36 is an exposure objective lens, 37 is a vibration isolation table, 38 is a light source for heat treatment, Reference numeral 39 is a heat treatment head, 40 is a heat treatment objective lens, and 41 is a heat treatment head driving device. In the apparatus shown in FIG. 5A, the master 27 having the resist layer formed on the upper surface by the method described in the first embodiment is placed on the turntable 29 with the resist surface facing upward.
Use 8 to fix. Then, while rotating the master 27, the exposure is started according to the predetermined information for the optical recording medium. As shown in FIG. 7, the heat treatment objective lens 4 emits light 56 that does not affect the photosensitivity of the resist layer 51 by following the exposure portion 52 sequentially formed by this exposure.
Irregularity pattern 54 is sequentially formed by irradiating through 0 and heating locally. A semiconductor laser is used as the heat treatment light source 38, but a similar effect can be obtained by using a carbon dioxide gas laser as another light source. In this case, since the light source becomes large, the heat treatment light source 38 is provided outside the heat treatment head 39 as shown in FIG.

When forming the uneven pattern described above,
It is necessary to pay attention to the contamination of the working environment and the contamination of the inside of the apparatus, especially the surface of the exposure objective lens by the gas generated by vaporizing the exposed portion of the resist layer. In order to avoid such a problem, the master exposure apparatus of the present invention is provided with a local exhaust mechanism. Here, the local exhaust mechanism will be briefly described. In FIGS. 4A and 5A, 43
Is an exhaust cover, 44 is a spacer, 45 is an exhaust duct,
46 is a cooling device, 47 is a filter, and 48 is an exhaust motor fan. The exhaust cover 43 is provided with an exposure window 49 as shown in FIGS. 4 (b) and 5 (b). Through this exposure window 49, the resist layer is provided with a laser according to predetermined information of the optical recording medium. Irradiation of light is performed. Further, a heat treatment light irradiation window 50 is provided in the exhaust cover 43 shown in FIG. 5B, and the resist layer is irradiated with light through the heat treatment light irradiation window 50 to locally heat the resist layer. . Further, the exhaust cover 43 is detachable for fixing or removing the master, and when it is attached to the apparatus, a rubber spacer 44 is sandwiched and fixed to improve the airtightness.

By the action of the exhaust motor fan 48, the flow of air near the master 27 flows from the outside to the inside of the exhaust cover 43 as shown in FIG. Exposing the resist layer in such a state of air flow,
When the heat treatment is performed, the gas generated by the vaporization of the exposed portion of the resist layer flows into the exhaust / exhaust duct 45 without flowing out of the exhaust cover 43 according to the flow of air. Then, the above-mentioned gas is sent to the cooling device 46 provided in the lower part of the device, and the above-mentioned gas is supplied to the inside of the cooling device 4
The air is cleaned by being forcibly cooled by 6 and captured by the filter 47.

Next, the two methods described above will be compared. The first method can be performed more easily than the second method, and since the mechanism of the device is simple, the equipment cost can be reduced. On the other hand, in the second method, since only the exposed region is locally heated, the influence of the heat treatment during exposure on the characteristics (mainly sensitivity) of the resist layer can be ignored.

When the master exposure apparatus of the present invention described above is used, when forming the concavo-convex pattern, the concavo-convex pattern corresponding to the predetermined information of the optical recording medium is not installed independently of the master exposure apparatus and the developing device. Can be formed on the resist layer, and it can be carried out with low equipment cost, space saving, and high work efficiency.

Although the present invention has been described with reference to a specific embodiment, it should not be considered that the present invention is limited thereto, and various modifications can be made without departing from the gist of the present invention.

[0064]

As described above, according to the present invention, it is possible to form a concave-convex pattern with high accuracy without the need for a developing process using a developing solution, and at the time of reproducing recorded information. It is possible to manufacture a high-performance and high-quality stamper for an optical recording medium with few defects causing defects and a poor appearance. Furthermore, it is possible to perform the exposure and development steps required to form the concavo-convex pattern at the same time, and it is possible to manufacture a high-performance and high-performance optical stamper with low equipment cost, space saving, high work efficiency. The effect that there is was obtained.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing a method for manufacturing a stamper for an optical recording medium of the present invention.

FIG. 2 is a conceptual diagram showing a conventional method of manufacturing a general stamper for an optical recording medium.

FIG. 3 is a conceptual diagram of a conventional general master exposure apparatus.

4A is a conceptual diagram of a master exposure apparatus having a heat treatment function of the present invention, and FIG. 4B is a top view of an exhaust cover thereof.

5A is a conceptual view of a master exposure apparatus having another heat treatment function of the present invention, and FIG. 5B is a top view of an exhaust cover thereof.

FIG. 6 is an explanatory view of forming a concavo-convex pattern by a method of performing heat treatment during the exposure process of the present invention.

FIG. 7 is an explanatory view of forming a concavo-convex pattern by another method of performing heat treatment during the exposure process of the present invention.

FIG. 8 is an explanatory view when a carbon dioxide gas laser is used as a light source for heat treatment of the master exposure apparatus of the present invention.

FIG. 9 is an explanatory view of the flow of air in the apparatus by the exhaust mechanism of the master exposure apparatus of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 master 2 resist layer 3 exposure part 4 concavo-convex pattern 5 conductor film 6 electroformed layer 7 optical recording medium stamper 8 master 9 resist layer 10 exposed part 11 concavo-convex pattern 12 conductor film 13 electroformed layer 14 optical recording medium stamper 15 master 16 Master Fixing Jig 17 Turntable 18 Spindle Motor 19 Exposure Laser Light Source 20 Fixed Optical System 21 Optical Head Drive 22 Mobile Optical System 23 Optical Head 24 Objective Lens 25 Vibration Isolator 26 Heater 27 Master 28 Master Fixing Jig 29 Turntable 30 Spindle motor 31 Exposure laser light source 32 Fixed optical system 33 Optical head drive device 34 Moving optical system 35 Optical head 36 Exposure objective lens 37 Anti-vibration table 38 Heat treatment light source 39 Heat treatment head 40 Heat treatment objective lens 41 Heat treatment head drive Device 42 Mirror 43 Exhaust Cover 44 Spacer 45 Exhaust Duct 46 Cooling Device 47 Filter 48 Exhaust Motor Fan 49 Exposure Window 50 Heat Treatment Light Irradiation Window 51 Resist Layer 52 Exposure Section 53 Exposure Section 54 Evaporation in Progress 54 Concavo-convex Pattern 55 Exposure Laser light 56 heat treatment light

Claims (7)

[Claims] 1. A step of forming a positive type resist layer on a master, a step of exposing the resist layer according to predetermined information of an optical recording medium, and a step of removing the exposed portion of the resist layer to form the resist layer. A method of manufacturing a stamper for an optical recording medium having a developing step of forming a concavo-convex pattern corresponding to predetermined information of the optical recording medium, wherein the developing step is performed by dry development. . 2. When forming the resist layer, poly (o)
-A phthalaldehyde) is used as a main material of a compound in which the terminal is acetylated or alkylated, and a heat treatment step is performed as a means of the dry development to form an uneven pattern corresponding to the information of the optical recording medium. The method of manufacturing a stamper for an optical recording medium according to claim 1, wherein 3. A step of forming a positive resist layer on a master, a step of exposing the resist layer according to predetermined information of an optical recording medium, and a step of removing the exposed portion of the resist layer by heat treatment. In the method of manufacturing a stamper for an optical recording medium having a developing step of forming a concavo-convex pattern according to predetermined information of the optical recording medium, the developing step by the heat treatment is not independent, and during the exposing step, After heating the entire resist layer to a predetermined temperature in advance, it is exposed according to the predetermined information of the optical recording medium while keeping the entire resist layer at the temperature, according to the information of the optical recording medium. 3. The method for manufacturing a stamper for an optical recording medium according to claim 2, wherein the uneven pattern is sequentially formed. 4. A step of forming a positive resist layer on a master, a step of exposing the resist layer according to predetermined information of an optical recording medium, and a step of removing the exposed portion of the resist layer by heat treatment. In the method of manufacturing a stamper for an optical recording medium having a developing step of forming a concavo-convex pattern according to predetermined information of the optical recording medium, the developing step by the heat treatment is not independent, and during the exposing step, In the process of exposing the resist layer according to predetermined information of the optical recording medium, the exposed portions sequentially formed by the exposure are locally exposed to light having a wavelength that does not affect the photosensitivity of the resist layer. 3. The method of manufacturing a stamper for an optical recording medium according to claim 2, wherein the uneven pattern corresponding to the information of the optical recording medium is sequentially formed by heating the optical recording medium. 5. The method for manufacturing a stamper for an optical recording medium according to claim 4, wherein the wavelength of the light is 600 nm or more. 6. A master exposure apparatus in which a master having a resist layer formed on its upper surface is fixed to a turntable, and the master is exposed by laser light according to predetermined information of an optical recording medium while rotating the master. A master exposure apparatus, wherein a heater for heating the master is provided in the turntable as a means for heating the entire layer. 7. A master disc exposure apparatus in which a master disc having a resist layer formed on its upper surface is fixed to a turntable, and the master disc is exposed by laser light according to predetermined information of an optical recording medium while rotating the master disc. A master exposure apparatus comprising a light source having a wavelength not affecting the photosensitivity of the resist layer and an objective lens as means for locally heating the layer.