JPH11283283A - Method for manufacturing master for recording medium production, master for recording medium production, substrate for recording medium, and recording medium - Google Patents

Abstract

(57) Abstract: In a mastering step of manufacturing a master for recording medium production, a latent image similar to a latent image formed by using a plurality of exposure beams in a conventional laser cutting apparatus is converted into a plurality of latent images. It can be formed without using an exposure beam. SOLUTION: When exposing a photosensitive layer to form a latent image,
By deflecting the exposure beam over a plurality of tracks and simultaneously modulating the intensity of the exposure beam so that the exposure beam is incident on the photosensitive layer only at the spots to be exposed on each track, a latent image can be formed simultaneously over a plurality of tracks. Do.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a master for producing a recording medium such as a read-only optical disk, a magneto-optical disk or a phase-change optical disk, and a method of manufacturing the same. In addition, the present invention relates to a recording medium substrate manufactured using the recording medium manufacturing master and a recording medium having a recording layer formed on the recording medium substrate.

[0002]

2. Description of the Related Art A recording medium such as a read-only optical disk, a magneto-optical disk, or a phase-change optical disk has a disk substrate made of an optically transparent resin, and an information signal is recorded on the disk substrate. A signal recording area, which is an area, is formed. In the signal recording area, a groove, which is a groove formed continuously along the track, and a pit row composed of a large number of pits are formed in a spiral or concentric manner at a predetermined track pitch for each track. In many conventional recording media, one surface of a disk substrate is a signal recording surface on which grooves and pit rows are formed, and the other surface is a reading surface. That is, when an information signal is reproduced from a recording medium, the side where no groove or pit row is formed is set as a reading surface, and laser light is irradiated from the side of the reading surface.

In such a recording medium, the shape of the concave / convex pattern such as grooves and pit rows formed on the surface of the disk substrate affects the performance of the recording medium. Therefore, in order to achieve a high recording density, it is required to form a concavo-convex pattern on a disk substrate with high precision.

[0004] When manufacturing such a disk substrate,
First, a photoresist serving as a photosensitive layer is applied on a glass master serving as a support, and then the photoresist is irradiated with an exposure beam along a track,
The photoresist is exposed. Thereby, a latent image corresponding to the predetermined concavo-convex pattern is formed on the photoresist. Conventionally, such a photoresist is exposed by using a laser cutting device using laser light as an exposure beam, and the laser light is condensed on the photoresist by an objective lens to expose the photoresist. I am trying to do it.

Next, by developing the latent image formed on the photoresist, an uneven pattern is formed on the photoresist. Next, Ni plating is performed on the photoresist on which the concavo-convex pattern is formed, and then the Ni plating is peeled off. As a result, a recording medium manufacturing master, that is, a stamper, made of Ni plating to which the concave / convex pattern formed on the photoresist is transferred is obtained. afterwards,
Using the stamper thus formed as a mold, a resin material is injection-molded. As a result, a disk substrate on which a predetermined concavo-convex pattern is formed is manufactured.

[0006] As described above, a laser cutting apparatus used for producing a disk substrate is, for example, shown in FIG.
, A laser light source 121 for emitting laser light of a predetermined wavelength, and a recording light intensity control unit 12 for controlling the laser light intensity so that the laser light intensity is at a predetermined stable level.
2 and photoresist 1 applied to glass master 110
A light intensity modulating unit 123 for modulating the intensity of the laser light applied to the beam 11, a beam splitter 124, a beam expander 125 for expanding the beam diameter, and a condensing unit for condensing the laser light on the photoresist 111 126.

[0007] The laser light emitted from the laser light source 121 enters a recording light intensity control unit 122, and the recording light intensity control unit 122 controls the light intensity. The recording light intensity control unit 122 removes the instability of the output of the laser light source 121 and stabilizes the light intensity of the laser light irradiated on the photoresist 111. , An analyzer 132, a beam splitter 133, a photodetector 134, and a recording light power control circuit 135.

[0008] The laser light from the laser light source 121 passes through the electro-optical element 131 and the analyzer 132, enters the beam splitter 133, and is separated into transmitted light and reflected light by the beam splitter 133.
Then, the light transmitted through the beam splitter 133 enters the photodetector 134 and the photodetector 1
34 detects the light intensity. The photodetector 134 converts the detected light intensity level of the laser light into a voltage level, and supplies the voltage level to the recording light power control circuit 135. The recording light power control circuit 135 compares the input from the photodetector 134 with the reference voltage level Ref so that the light intensity of the laser light transmitted through the electro-optical element 131 is always constant. Voltage. As a result, the laser light emitted from the recording light intensity control unit 122, that is, the light intensity of the laser light reflected by the beam splitter 133,
Even if the output is unstable, the level is always stable.

The laser light reflected by the beam splitter 133 and emitted from the recording light intensity control unit 122 enters the light intensity modulation unit 123,
3 modulates the light intensity. The light intensity modulator 123 includes a first convex lens 136 and the light intensity modulator 13.
7 and a second convex lens 138. And
The laser light reflected by the beam splitter 133 is condensed by a first convex lens 136 having a predetermined focal length, and then enters a light intensity modulator 137, where the desired exposure pattern is obtained. Is applied to the light intensity modulation.

The laser light having been subjected to light intensity modulation by the light intensity modulator 137 is incident on a second convex lens 138 having a predetermined focal length, and is converted into parallel light by the second convex lens 138. The light enters the beam splitter 124 and is reflected by the beam splitter 124. Then, the laser light reflected by the beam splitter 124 enters the beam expander 125. The beam expander 125 is for expanding the beam diameter of the laser beam, and includes a third convex lens 139 having a predetermined focal length and a fourth convex lens 140 having a predetermined focal length. In this beam expander 125, the third convex lens 139 and the fourth
When the gap with the convex lens 140 is changed, the magnification of the beam diameter by the beam expander 125 changes.
In this laser cutting apparatus, the spot diameter of the laser light focused on the photoresist 111 can be adjusted by adjusting the magnification of the beam diameter by the beam expander 125.

The laser beam whose beam diameter has been adjusted by the beam expander 125 is incident on the condenser 126.
The condensing unit 126 is for condensing the laser light on the photoresist 111, and includes an objective lens 142. Then, the laser light incident on the objective lens 142 is condensed by the objective lens 142 and irradiated on the photoresist 111.

Although not shown, the laser cutting apparatus includes a turntable for holding and rotating a glass master 110 coated with a photoresist 111,
And a moving mechanism for moving the irradiation position of the laser beam in the radial direction of the glass master 110. When exposing the photoresist 111 by using this laser cutting apparatus, the photoresist 1 is exposed by a turntable.
While rotating the glass master 110 coated with 11,
The irradiation position of the laser beam is moved by the moving mechanism to the glass master 1
It is moved by the same distance per rotation in the 10 radial directions.
Thereby, the photoresist 11 on the glass master 110 is
First, a latent image corresponding to a groove or a pit row is formed in a spiral or concentric shape at a fixed track pitch.

In a writable recording medium such as a phase-change optical disk or a magneto-optical disk, it is necessary to previously record an address signal and the like necessary for writing an information signal on the recording medium. Therefore, some writable recording media have grooves or pit rows formed in a double spiral shape in order to previously form a concavo-convex pattern corresponding to an address signal or the like on a disk substrate. That is, in a read-only optical disk, the track usually has a single spiral structure as shown in FIG. 17, but in a writable recording medium such as a phase-change optical disk or a magneto-optical disk, the track is shown in FIG. Some have a double spiral structure as shown.

For example, a current ISO format magneto-optical disk adopts a land address format as shown in FIG. 19, and a groove 201 and a pit row 202 are formed in a double spiral shape. That is, in the current ISO format magneto-optical disk,
A pit row 202 indicating an address signal or the like is formed in a land portion narrowed between the groups 201, and the groove 20 is formed.
1 and the pit row 202 are formed in a double spiral shape.

An intermittent wobble format magneto-optical disk as shown in FIG. 20 has also been proposed. In the intermittent wobble format, as shown in FIG. 20, a pair of grooves 211 and 212 are formed in a double spiral shape, and one groove 212 is meandered to add address information to the groove 212. In the following description, a groove formed so as to meander like the groove 212 is referred to as a wobbling groove,
A groove formed without meandering like the groove 211 is called a straight groove.

In order to manufacture a recording medium having a format as shown in FIGS. 19 and 20, when a photoresist is exposed to form a latent image corresponding to a groove or pit row as described above, two It is necessary to expose the photoresist with an exposure beam. That is, for example, to realize a land address format as shown in FIG.
At the same time as forming a latent image corresponding to the groove 201 by the first exposure beam, it is necessary to form a latent image corresponding to the pit row 202 formed on the land by the second exposure beam. For example, in order to realize the intermittent wobble format as shown in FIG. 20, a latent image corresponding to the straight groove 211 is formed by the first exposure beam, and at the same time, the wobbling groove 212 is formed by the second exposure beam. It is necessary to form a latent image corresponding to.

Therefore, conventionally, when manufacturing a recording medium having grooves and pit rows formed in a double spiral shape, a laser cutting apparatus capable of exposing a photoresist with two exposure beams has been used. ing. FIG. 21 shows a schematic configuration of such a laser cutting device. Note that, in FIG. 21, the same reference numerals as in FIG. 16 denote parts configured similarly to the laser cutting device shown in FIG.

The laser cutting device shown in FIG.
This is a laser cutting apparatus capable of forming a latent image corresponding to a straight groove by a first exposure beam and forming a latent image corresponding to a wobbling groove by a second exposure beam. The laser light source 121 emits laser light of a predetermined wavelength, the recording light intensity control unit 122 controls the laser light intensity so that the laser light intensity becomes a predetermined stable level, and the laser light is applied to the glass master 110. A first light intensity modulator 123a for modulating the light intensity of the first exposure beam applied to the photoresist 111, and a light intensity of the second exposure beam applied to the photoresist 111 applied to the glass master 110; A second light intensity modulator 123b that modulates the first exposure beam, an optical deflector 143 that deflects the second exposure beam subjected to the light intensity modulation by the second light intensity modulator 123b, Polarization beam splitter 144 for synthesizing the two exposure beams
And a beam expander 1 for expanding the beam diameter
25, and a condensing unit 126 for condensing the laser light on the photoresist 111.

The laser light emitted from the laser light source 121 enters a recording light intensity control unit 122, and the intensity is controlled by the recording light intensity control unit 122. The recording light intensity control unit 122 removes the instability of the output of the laser light source 121 and stabilizes the light intensity of the exposure beam applied to the photoresist 111. The element 131, the analyzer 132, the first beam splitter 133a, and the second beam splitter 1
33b, a photodetector 134, and a recording light power control circuit 135.

The laser light emitted from the laser light source 121 is applied to the electro-optical element 131 and the analyzer 13.
2 and is incident on the first beam splitter 133a, and is separated into reflected light and transmitted light by the first beam splitter 133a. In this laser cutting device, the laser light reflected by the first beam splitter 133a becomes a first exposure beam. Further, the laser light transmitted through the first beam splitter 133a enters the second beam splitter 133b, and is separated into reflected light and transmitted light by the second beam splitter 133b. In this laser cutting device, the laser beam reflected by the second beam splitter 133b becomes a second exposure beam.

The laser beam transmitted through the second beam splitter 133b is incident on the photodetector 134, and the light intensity is detected. Then, the photodetector 134
Converts the detected light intensity level of the laser light into a voltage level and supplies it to the recording light power control circuit 135. The recording light power control circuit 135 includes a photodetector 134
Is compared with the reference voltage level Ref, and a voltage is applied to the electro-optical element 131 so that the light intensity of the laser beam transmitted through the electro-optical element 131 is always constant. Accordingly, the light intensity of the laser light emitted from the recording light intensity control unit 122 is always at a stable level even if the output of the laser light source 121 is unstable.

On the other hand, the laser beam reflected by the first beam splitter 133a, that is, the first exposure beam, enters the first light intensity modulator 123a, and the light intensity is modulated by the first light intensity modulator 123a. Is performed. The first light intensity modulator 123a includes a first convex lens 136a, a light intensity modulator 137a, and a second convex lens 138a.

Then, the first beam splitter 133a
The first exposure beam reflected by the light source is condensed by a first convex lens 136a having a predetermined focal length, and then enters a light intensity modulator 137a, where the light intensity is modulated by the light intensity modulator 137a. Is applied. Here, the first exposure beam is for forming a latent image corresponding to a straight groove continuously formed at a constant depth along a track. Therefore, the light intensity modulator 137a performs light intensity modulation on the first exposure beam so that the first exposure beam has a constant light intensity.

Then, the first exposure beam subjected to the light intensity modulation by the light intensity modulator 137a is incident on a second convex lens 138a having a predetermined focal length.
Are converted into parallel light by the convex lens 138a, and are incident on the beam splitter 124a.
24a. Then, the first exposure beam reflected by the beam splitter 124a enters the polarization beam splitter 144 via the half-wave plate 145. Then, the first exposure beam incident on the polarization beam splitter 144 is
And is incident on the beam expander 125.

The laser beam reflected by the second beam splitter 133b, that is, the second exposure beam is incident on the second light intensity modulator 123b, and the light intensity is modulated by the second light intensity modulator 123b. Is performed. The second light intensity modulator 123b includes a first convex lens 136b, a light intensity modulator 137b, and a second convex lens 138b.

Then, the second beam splitter 133b
The second exposure beam reflected by the light source is condensed by a first convex lens 136b having a predetermined focal length, then enters a light intensity modulator 137b, and is modulated by the light intensity modulator 137b. Is applied. Here, the second exposure beam is for forming a latent image corresponding to a wobbling groove formed continuously at a constant depth along the track. Therefore, the light intensity modulator 137b performs light intensity modulation on the second exposure beam so that the second exposure beam has a constant light intensity.

Then, the second exposure beam having been subjected to the light intensity modulation by the light intensity modulator 137b is incident on a second convex lens 138b having a predetermined focal length.
Is converted into parallel light by the convex lens 138b, and is incident on the beam splitter 124b.
24b. Then, the second exposure beam reflected by the beam splitter 124b enters the optical deflector 143, and is optically deflected by the optical deflector 143 so as to face the wobbling groove meandering. That is, the second exposure beam is deflected by the optical deflector 143 in a direction orthogonal to the track direction at a predetermined cycle.

The first exposure beam optically deflected by the optical deflector 143 is the beam splitter 1
24c, and is reflected by the beam splitter 124c. Then, the second exposure beam reflected by the beam splitter 124c enters the polarization beam splitter 144, and the polarization beam splitter 144
Accordingly, the light is reflected so that the traveling direction is substantially the same as that of the first exposure beam, and enters the beam expander 125.

The beam expander 125 is an optical system for expanding the beam diameters of the first and second exposure beams, and includes a pair of convex lenses 139 having a predetermined focal length.
140 is provided. This beam expander 125
In, when the gap between the pair of convex lenses 139 and 140 is changed, the magnification of the beam diameter by the beam expander 125 changes. In this laser cutting apparatus, the photoresist 111 is adjusted by adjusting the magnification of the beam diameter by the beam expander 125.
It is possible to adjust the spot diameter of the first and second exposure beams converged thereon.

The first and second exposure beams whose beam diameters have been adjusted by the beam expander 125 are
26. The condensing unit 126 is for condensing the first and second exposure beams on the photoresist 111, and includes an objective lens 142. Then, the first and second exposure beams incident on the objective lens 142 are
Photoresist 1 collected by the objective lens 142
11 is irradiated.

Although not shown, the laser cutting apparatus includes a turntable for holding and rotating a glass master 110 coated with a photoresist 111,
The irradiation positions of the first and second exposure beams are set to the glass master 11
0 in the radial direction. When exposing the photoresist 111 with this laser cutting apparatus, the irradiation mechanism of the first and second exposure beams is moved by a moving mechanism while rotating the glass master 110 coated with the photoresist 111 by a turntable. The glass master 110 is moved in the radial direction by an equal distance per rotation.

Then, as described above, the photoresist 111
When exposing, the spot position of the first exposure beam,
The spot position of the second exposure beam is separated from the spot position of the second exposure beam by a small distance in a direction perpendicular to the track direction (ie, in the disk radial direction). The adjustment of the spot position of the first exposure beam and the spot position of the second exposure beam is performed so that the reflection angle of the second exposure beam by the polarizing beam splitter 144 is inclined by a required amount in the disk radial direction. This is done by giving the beam splitter 144 an appropriate tilt angle.

Then, with the spot position of the first exposure beam and the spot position of the second exposure beam separated by a predetermined distance, the photoresist 111 is rotated while rotating the glass master 110 as described above. Is exposed, a latent image formed by the first exposure beam (that is, a latent image corresponding to a straight groove) and a latent image formed by the second exposure beam (that is, a latent image corresponding to a wobbling groove) Are formed in a double spiral shape.

In the above description, an example was described in which a latent image corresponding to the intermittent wobble format as shown in FIG. 20 was formed.
It is also possible to form a latent image corresponding to the land address format as shown in FIG.

When a latent image corresponding to a format in which a groove and a pit row are formed in a double spiral like a land address format is formed by the laser cutting device, the first exposure beam and the second exposure beam are used.
The latent image corresponding to the groove may be formed by one of the exposure beams, and the latent image corresponding to the pit row may be formed by the other. Specifically, the optical deflection by the optical deflector 143 is prevented from being performed, and one of the first light intensity modulator 123a and the second light intensity modulator 123b is formed into a pit row with respect to the exposure beam. Light intensity modulation may be performed so as to correspond thereto, and light intensity modulation may be performed so as to correspond to the groove on the exposure beam.

As described above, by using the laser cutting device capable of exposing the photoresist with two exposure beams, as shown in FIG. 19 and FIG. It is possible to manufacture a recording medium formed on the substrate.

[0037]

By the way, recording media are required to have higher recording density. In order to increase the recording density of a recording medium, it is necessary to form finer pits or finer grooves.
For example, in a next-generation read-only optical disk, it is desired that the shortest pit length of a pit row corresponding to an information signal be reduced to about 0.2 μm.

In order to realize such fine pits or narrower grooves, it is required to make the spot diameter of the exposure beam smaller in the exposure step of exposing the photoresist as described above. I have.
Here, when laser light is used as the exposure beam, the minimum spot diameter d depends on the wavelength λ of the laser light and the numerical aperture NA of the objective lens, and is expressed by the following equation (1).

D = 1.22 × λ / NA (1) Therefore, when a laser beam is used as an exposure beam,
In order to reduce the spot diameter of the exposure beam, the wavelength λ of the laser beam should be shortened or the numerical aperture NA of the objective lens should be reduced.
Should be increased. As for the wavelength λ of the laser beam, reduction of the wavelength to about 250 nm in the far ultraviolet region is currently being studied. However, at shorter wavelengths, a laser light source that continuously oscillates at room temperature itself has not been developed, and even if such a laser light source has been developed, optical systems and photoresists corresponding to such short wavelengths have not been developed. Development is also necessary and difficult to achieve. Further, the numerical aperture NA of the objective lens has already been used at a location near the theoretical limit value of 1.0, and there is little room for improvement.

As described above, in the conventional optical system in which the minimum spot diameter d is defined by the wavelength λ of the laser beam and the numerical aperture NA, the reduction of the spot diameter has almost reached the limit. Therefore, it is almost impossible to produce a next-generation recording medium with higher recording density by the conventional exposure method.

In recent years, proposals have been made to overcome the limit of light using an electron beam lithography apparatus. this is,
In an exposure step, an electron beam capable of forming a beam narrower than a laser beam is used as an exposure beam for exposing a photoresist. Exposure of photoresist by electron beam has already been developed as a next-generation lithography technique for semiconductors. Although its application to the production of recording media is still young, it is likely that it will become a mainstream technology in the near future.

By actually using an electron beam lithography apparatus instead of a laser cutting apparatus, an area density 2.6 times higher than that of a DVD (trademark) manufactured using the laser cutting apparatus is achieved. The optical disk has been announced by Pioneer at the Japan Society of Applied Physics in the spring of 1997. The comparison is shown in Table 1.
In a laser cutting device used for producing a DVD, the wavelength λ of the laser light is 351 nm, and the numerical aperture NA of the objective lens is 0.90.

[0043]

[Table 1]

As shown in Table 1, when an electron beam is used as an exposure beam, the spot diameter can be made much smaller than when a laser beam is used.
Therefore, a dramatic increase in recording density can be expected by using an electron beam drawing apparatus.

However, at present, various problems remain in practical use of an electron beam lithography apparatus, such as problems of handling an electron beam and a mechanical system in a high vacuum. One of these problems is that it is difficult for an electron beam lithography apparatus to expose a photoresist using a plurality of exposure beams (that is, to make the exposure beam a multi-beam).

Several methods have been proposed for multi-beam formation in an electron beam lithography apparatus for the purpose of improving the throughput in the field of semiconductor lithography, but realization is considerably difficult. Hereinafter, the reason will be described.

In order to achieve multi-beams in an electron beam lithography apparatus, it is necessary to prepare a plurality of electron guns. But,
In a normal electron beam lithography system, when a plurality of electron guns are simply provided, the electron beams emitted from those electron guns are
Since they pass through the same electron beam optical system, they cannot be modulated or deflected independently.

Therefore, in order to achieve the multi-beam in the electron beam lithography apparatus, not only a plurality of electron guns are prepared but also the electron beam optical systems from the electron guns to the objective lens are provided with independent optical systems. Must be a system. However, if an independent electron beam optical system is provided for each electron beam, the scale of the apparatus becomes very large and becomes very complicated.

In order to realize a multi-beam with a small electron beam lithography apparatus, a so-called array type micro-array is used in which the entire length from the electron gun to the objective lens is about 2.5 mm per column and a plurality of them are arranged in an array. A column drawing method has also been proposed. However, in the array type micro column drawing method, the acceleration voltage of the electron beam can be applied only up to about 1 kV due to its small size. In the example of Pioneer, the acceleration voltage of the electron beam is set to 50 k.
V. As described above, when the array-type micro column drawing method is employed, the acceleration voltage of the electron beam becomes extremely small, so that the scattering amount of the electron beam after the photoresist is incident becomes large, and the electron beam is effectively reduced. There is a disadvantage that the electron beam cannot be focused.

Further, in addition to the above-mentioned problems, it is difficult to make the intensity and shape of each electron beam uniform in the multi-beam system in the electron beam writing apparatus.
There is a problem that it is difficult to set the spot position of each electron beam with high accuracy, and it is expected that the realization thereof is considerably more difficult than in the case of using a multi-beam laser cutting device.

As described above, it is difficult to realize multi-beams in an electron beam lithography apparatus. Therefore, in an electron beam lithography apparatus, the format shown in FIGS. Format that draws two or more spirals).

The present invention has been proposed in view of the above-mentioned conventional situation, and is shown in FIGS. 19 and 20 by a method which can be realized relatively easily without using a multi-beam. It is an object of the present invention to be able to manufacture a master for manufacturing a recording medium corresponding to such a format. In other words, the present invention provides a method capable of forming a latent image similar to a latent image formed by using a plurality of exposure beams in a conventional laser cutting apparatus without using a plurality of exposure beams. I do.

[0053]

According to the present invention, there is provided a method of manufacturing a master for a recording medium in which a predetermined concave / convex pattern is formed along a track. The method includes an exposure step of exposing to form a latent image, a developing step of developing the latent image formed on the photosensitive layer, and a transfer step of transferring an uneven pattern formed on the photosensitive layer.

In the exposure step, the photosensitive layer formed on the support is irradiated with an exposure beam along a track to expose the photosensitive layer, and a latent image corresponding to a predetermined concavo-convex pattern is exposed. Formed in layers. In the development process,
By developing the latent image formed on the photosensitive layer in the above exposure step, an uneven pattern is formed on the photosensitive layer. Also,
In the transfer step, a master for recording medium production on which a predetermined uneven pattern is formed is manufactured by transferring the uneven pattern formed on the photosensitive layer in the developing step.

In the method of manufacturing a master for manufacturing a recording medium according to the present invention, in the exposure step of exposing the photosensitive layer to form a latent image, the exposure beam is deflected over a plurality of tracks, The method is characterized in that a latent image is simultaneously formed over a plurality of tracks by modulating the intensity of the exposure beam so that the exposure beam is incident on the photosensitive layer only at a portion to be exposed.

In the exposure step, a latent image corresponding to a groove formed along a track is formed, and when forming the latent image, an exposure beam is formed so that at least a part of the groove meanders. May be performed.

The master for manufacturing a recording medium according to the present invention is a master for manufacturing a recording medium manufactured by the above-described manufacturing method. The master for producing a recording medium may have a groove pattern corresponding to a groove formed along a track as a predetermined concavo-convex pattern formed by transferring the concavo-convex pattern formed on the photosensitive layer. When the master for producing a recording medium has a groove pattern, the groove pattern may be formed so that at least a part thereof meanders.

The substrate for a recording medium according to the present invention is a substrate for a recording medium manufactured by using a master for manufacturing a recording medium manufactured by the above manufacturing method. The recording medium substrate may have a groove formed along the track. When the recording medium substrate has a groove, the groove may be formed so that at least a part of the groove is meandering.

Further, the recording medium according to the present invention is a recording medium in which a recording layer is formed on a recording medium substrate produced using a recording medium production master produced by the above-mentioned production method. The recording medium manufacturing substrate of this recording medium is:
It may have a groove formed along the track. When the recording medium manufacturing substrate has a groove, the groove may be formed so that at least a part thereof meanders.

[0060]

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

First, an outline of an example of a method of manufacturing a master for manufacturing a recording medium to which the present invention is applied will be described.

When a master for producing a recording medium is manufactured, first, as shown in FIG. 1, a disk-shaped glass master 10 whose surface is sufficiently polished and cleaned is prepared as a support. Next, a photosensitive layer is formed on the glass master 10.
Specifically, for example, as shown in FIG.
A resist 11 for an electron beam, which becomes alkali-soluble by exposure treatment with an electron beam, is applied on top of the resist. Here, the film thickness of the electron beam resist 11 is preferably formed so as to correspond to the desired maximum depth of the groove or pit, and specifically, for example, about 0.1 μm.

Next, as shown in FIG. 3, an exposure beam is applied to the electron beam resist 11 formed on the glass master 10 along the track as shown in FIG. Irradiate. Thus, the electron beam resist 11 is exposed, and a latent image corresponding to a predetermined concavo-convex pattern is formed on the electron beam resist 11. When irradiating the electron beam resist 11 with the electron beam, the electron beam is deflected over a plurality of tracks, and the electron beam is incident on the electron beam resist 11 only at the portions to be exposed on each track. By modulating the intensity of the electron beam as described above, a latent image is simultaneously formed over a plurality of tracks. This exposure method will be described later in detail.

Here, the electron beam resist 1
Irradiation to 1 rotates the glass master 10 and
This is performed while moving the glass master 10 by a predetermined amount in the radial direction. By exposing the electron beam resist 11 with the electron beam in this manner, a latent image corresponding to a groove, a pit row, or the like is formed on the electron beam resist 11.

Next, the exposed portion, that is, the exposed portion of the electron beam resist 11 is removed by developing the electron beam resist 11 exposed in the exposure step with an alkaline developer. Thereby, the latent image formed on the electron beam resist 11 in the exposure step is developed, and a predetermined concavo-convex pattern is formed on the electron beam resist 11. In particular,
For example, as shown in FIG. 4, a groove pattern 15 is formed as a concave / convex pattern corresponding to a groove formed along a track. Alternatively, for example, as shown in FIG. 5, a pit pattern 17 is formed as an uneven pattern corresponding to a pit row formed along a track.

Next, the latent image formed on the electron beam resist 11 is transferred by developing the latent image to obtain a master for manufacturing a recording medium on which a predetermined irregular pattern is formed. Specifically, for example, as shown in FIG. 6, Ni or the like is plated on the electron beam resist 11,
The plating layer 18 is formed. Thereafter, the plating layer 18 is peeled off to obtain a master for manufacturing a recording medium on which the predetermined pattern of irregularities formed on the electron beam resist 11 is transferred.

Next, the electron beam drawing apparatus used in the above-mentioned exposure step will be described in detail with reference to specific examples.

As shown in FIG. 7, the electron beam writing apparatus rotates and drives an electron beam emitting section 21 for generating, converging, and emitting an electron beam, and a glass master 10 on which an electron beam resist 11 is applied on the upper surface. And a glass substrate 10 as shown by arrow A in FIG.
And a translation mechanism 23 that translates
These are all mounted on a vibration isolation table 24 for removing external vibrations at the installation location.

Although not shown, the electron beam emitting section 21, the rotation drive mechanism 22, and the parallel movement mechanism 23 are connected to a computer control device, and their operations are controlled by the computer control device. . That is, by controlling the electron beam emitting unit 21 by the computer control device, for example, turning on / off the electron beam, adjusting the spot diameter of the focused electron beam,
An electron beam deflection operation and the like are controlled. The rotation speed and the like of the glass master 10 are controlled by controlling the rotation drive mechanism 22 by the computer control device.
Further, the translation mechanism 23 is controlled by a computer control device.
Is controlled, the moving speed and the like of the glass master 10 are controlled.

In the above electron beam lithography apparatus, the electron beam emitting section 21 is, for example, lanthanum hexaboride (LaB
₆ ) and a condenser lens 2 for converging the electron beam emitted from the electron gun 25.
6, a blanking electrode 27 for switching on / off of the electron beam, an aperture 28, a beam deflection electrode 29 for deflecting the electron beam, and a spot diameter of the electron beam incident on the electron beam resist 11. And an objective lens 31 for converging the electron beam, and these are disposed inside a housing 32 evacuated to a high vacuum. The condenser lens 26, the focus adjustment lens 30, and the objective lens 31 are so-called electrostatic lenses or electromagnetic lenses, and control the path of the electron beam by applying an electric field or a magnetic field to the electron beam.

When exposing the electron beam resist 11 with an electron beam, an electron beam is emitted from the electron gun 25 of the electron beam emission section 21. At this time, the accelerating voltage should be set so that the scattering amount when the electron beam is incident on the electron beam resist 11 is sufficiently small, and specifically, it is preferably about several kV to 100 kV. .

The electron beam emitted from the electron gun 25 is focused by the condenser lens 26, passes between the blanking electrodes 27, and passes through the aperture 2.
Reach 8. Here, the blanking electrode 27 is for performing intensity modulation of the electron beam. In other words,
The blanking electrode 27 is for switching on / off of an electron beam applied to the electron beam resist 11.

Specifically, when no voltage is applied to the blanking electrode 27, at least a part of the electron beam is made to pass through the opening of the aperture 28, and On the other hand, when a voltage is applied, the electron beam is deflected by the electric field between the blanking electrodes so that the entire electron beam deviates from the opening of the aperture 28. As a result, when no voltage is applied to the blanking electrode 27, the aperture 2
The electron beam passes through the opening 8 and the electron beam exit 2
1 emits an electron beam, and a blanking electrode 2
When a voltage is applied to 7, the electron beam is blocked by the aperture 28, and the electron beam is not emitted from the electron beam emitting unit 21.

When no voltage is applied to the blanking electrode 27, the electron beam passing through the opening of the aperture 28 passes between the beam deflection electrodes 29, and then passes through the focus adjusting lens 30 and the objective lens. Lens 31
Focused by Here, the beam deflection electrode 29 is
This is for deflecting the electron beam. That is, the electron beam emitting section 21 is used for the electron beam resist 1.
By applying an electric field to the electron beam by the beam deflection electrode 29 when exposing 1, the electron beam can be deflected over a plurality of tracks in a direction orthogonal to the track direction. . In addition,
The intensity modulation of the electron beam performed using the blanking electrode 27 and the electron beam deflection operation performed using the beam deflection electrode 29 will be described later in detail.

The electron beam focused by the focus adjusting lens 30 and the objective lens 31 so as to have a predetermined spot diameter (several nm to several μm) is emitted from the electron beam emitting unit 21. Then, the electron beam emitted from the electron beam emitting unit 21 in this way enters the electron beam resist 11 applied on the glass master 10.

Here, the glass master 10 coated with the electron beam resist 11 is attached to a rotation drive mechanism 22. The rotation drive mechanism 22 includes a turntable on which the glass master 10 is mounted and fixed, and an air spindle that rotates the turntable. It is preferable that the air spindle can rotate the turntable at a high speed up to, for example, about 3600 rpm, and can control the rotation speed with high accuracy. Specifically, for example, the rotation speed of the air spindle is controlled by a servo mechanism using an optical rotary encoder so that the rotation jitter is 10 ⁻⁷ or less per rotation. Then, the rotation drive mechanism 22 drives the glass master 10 placed on the turntable to rotate by rotating the turntable at a predetermined rotation speed by the air spindle.

The rotation drive mechanism 22 is a parallel movement mechanism 23 composed of a so-called linear motor type air slide device.
Attached to. The electron beam lithography apparatus can move the entire rotary drive mechanism on which the glass master 10 is placed in the radial direction of the glass master 10 by the parallel moving mechanism 23 as shown by an arrow A in the figure. It has become. Here, a laser scale is attached to the translation mechanism 23. And the parallel moving mechanism 2
In No. 3, by performing a moving operation of the rotary drive mechanism 22 while measuring a moving amount by a laser scale, the moving operation can be performed with a feeding accuracy of several nm or less.

Generally, when an electron beam collides with another atom or molecule during propagation, the electron beam is scattered by the collision and suffers an energy loss having a spread. Therefore, the path of the electron beam emitted from the electron gun 25 is desirably set to a high vacuum. Therefore, as described above, it is preferable to evacuate the inside of the housing 32 of the electron beam emitting unit 21 to maintain the vicinity of the electron gun 25 at an ultra-high vacuum of about 10 ⁻⁶ Pa or less. As shown in FIG. 3, the rotation drive mechanism 22 and the parallel movement mechanism 23 are
3, and the inside of the housing 33 is preferably maintained at a degree of vacuum of about 10 ⁻³ Pa or less.

Next, the exposure of the electron beam resist 11 performed using the above-described electron beam drawing apparatus will be described in detail.

When exposing the electron beam resist 11, the characteristic of the electron beam that the deflection can be performed at high speed is utilized. The laser beam is deflected by an optical deflector using an acousto-optic element, an electro-optic element, or the like, but cannot be deflected at high speed, and can be deflected only at a frequency of about 10 MHz at the maximum. On the other hand, electron beam deflection is performed by applying an electric field perpendicular to the traveling direction of the electron beam to bend the path, or by applying a magnetic field perpendicular to the traveling direction of the electron beam to change the path. This is done by bending electromagnetic deflection. And
In the case of an electron beam that can be deflected by such a principle, it is possible to deflect much faster than the deflection of laser light. Specifically, it is necessary to deflect at a frequency of about several hundred MHz. Is also possible.

In the present exposure method, by utilizing the characteristics of the electron beam capable of high-speed deflection of about several hundred MHz, the electron beam emitted from the electron beam emitting section 21 is rapidly scanned over a plurality of adjacent tracks. The electron beam resist 11 is exposed while deflecting, whereby a latent image is simultaneously formed over a plurality of tracks.

That is, in the present exposure method, as shown in FIG. 8, the electron beam is deflected at high speed over a plurality of tracks, and the electron beam is applied to the electron beam resist 11 only at the portions to be exposed on each track. A latent image is simultaneously formed over a plurality of tracks by modulating the intensity of the electron beam so that the laser beam is incident. In FIG. 8, two tracks (TrackA and TrackA) are used.
3B illustrates an example in which a latent image is simultaneously formed over B). However, it goes without saying that a latent image can be formed simultaneously over three or more tracks by increasing the amplitude of deflection.

When the electron beam resist 11 is exposed as described above, the electron beam is deflected at high speed over a plurality of tracks by controlling the voltage applied to the beam deflection electrode 29. At the same time, by controlling the voltage applied to the blanking electrode 27,
The on / off of the electron beam is switched so that the electron beam is incident on the electron beam resist 11 only at the portions to be exposed on each track. As a result, portions corresponding to a plurality of tracks are alternately exposed in a pulse shape as shown in FIG.

Here, the interval between pulses on one track is Δ
Assuming that R, the pulse interval ΔR is the product of the recording linear velocity V and the deflection period T as shown in the following equation (1-1).

ΔR = V × T (1-1) If this pulse interval ΔR is smaller than the spot diameter of the electron beam, adjacent pulses on one track have an overlap. That is, assuming that the spot diameter of the electron beam is φ, if ΔR ≦ φ, adjacent pulses on one track have an overlap. If adjacent pulses on one track overlap, exposure can be performed continuously along the track, so that a latent image corresponding to the groove can be formed.

For example, if the deflection frequency Fd = 100 MHz, the deflection cycle T = 10 nsec, and if the recording linear velocity V = 1.0 m / s, from the above equation (1-1),
The pulse interval ΔR = 10 nm. On the other hand, the spot diameter φ of the electron beam is assumed to be about 100 nm in consideration of the use of manufacturing a master for producing a recording medium.
Therefore, the pulse interval ΔR = 10 nm is a value that is sufficiently smaller than the spot diameter φ of the electron beam. Therefore, adjacent pulses on one track overlap each other, and a latent image corresponding to a groove can be sufficiently formed.

As described above, when performing the intensity modulation and deflection operation of the electron beam, the voltage applied to the blanking electrode 27 is controlled based on the modulation signal corresponding to the desired exposure pattern to turn on the electron beam. In addition to controlling the on / off operation and controlling the voltage applied to the beam deflection electrode 29 based on a deflection signal corresponding to a desired exposure pattern, the electron beam deflection operation is controlled. Here, the relationship between the modulation signal for controlling on / off of the electron beam and the deflection signal for controlling the deflection operation of the electron beam is as shown in FIG.

In FIG. 9, thick lines a and b in the line indicating the deflection signal indicate the timing at which the electron beam resist 11 is irradiated with the electron beam. That is,
One thick line portion a indicates the timing at which the electron beam is irradiated on one track, and the other thick line portion b indicates the timing at which the electron beam is irradiated on the other track.

As shown in FIG. 9, the frequency Fm of the modulated signal
Must be higher than the frequency Fd of the deflection signal,
Assuming that the number of tracks to be simultaneously drawn is N, the relationship between the frequency Fm of the modulation signal and the frequency Fd of the deflection signal is as shown in the following equation (1-2).

Fm = 2 × (N−1) × Fd (1-2) Therefore, for example, when drawing over two tracks (TrackA and TrackB) as shown in FIG.
Fm = 2 × Fd, and for example, as shown in FIG. 10, three tracks (TrackA, TrackB, TrackC)
When drawing is performed over Fm, Fm = 4 × Fd. When two tracks have a double spiral structure, drawing may be performed over two tracks as shown in FIG. 8, and when three tracks have a triple spiral structure, What is necessary is just to draw over three tracks as shown in FIG.

By the way, the number N of tracks to be simultaneously drawn
Increases, the frequency Fm of the modulated signal must be increased, as can be seen from equation (1-2). Therefore, the maximum value of the number N of tracks that can be simultaneously drawn by applying the present invention is defined by the upper limit of the frequency Fm of the modulation signal. However, in the electron beam lithography apparatus, the deflection is also used as a means for modulating the intensity of the electron beam. Therefore, the intensity modulation can be performed at a very high speed, similarly to the deflection operation. Therefore, for example, up to about five tracks, it is sufficiently possible to apply the present invention and draw simultaneously.

Further, according to the above-described exposure method, FIG.
As shown in FIG. 1, a latent image corresponding to a wobbling groove can be formed. When a latent image corresponding to the wobbling groove is formed, the timing of switching on / off of the electron beam and the amplitude of the deflection operation of the electron beam may be controlled so that the trajectory of the exposure pulse meanders. FIG. 11 shows an exposure pattern when a latent image corresponding to a straight groove and a latent image corresponding to a wobbling groove are simultaneously formed.

Further, a latent image corresponding to a pit row can be formed by the above-described exposure method. When a latent image corresponding to a pit row is formed, as shown in FIG. 12, the electron beam resist 11 is formed only in a portion corresponding to the pit.
The on / off of the electron beam may be switched so that the electron beam is incident on the substrate. FIG. 12 shows an exposure pattern corresponding to a pit row of each track when a latent image corresponding to a pit row is simultaneously formed over two tracks (Track A and Track B), and also corresponds to the exposure pattern. The modulation signal and the deflection signal are shown corresponding to the exposure pattern.

By employing the above-described exposure method, an exposure pattern having a plurality of spiral structures, which has been conventionally realized by using a plurality of exposure beams, is realized by using only one exposure beam. It is possible to do. In other words, by adopting the above-described exposure method, it is not necessary to employ an electron beam lithography apparatus which is difficult to realize, and it is not necessary to adopt a multi-beam method. It is possible to manufacture a recording medium manufacturing master having a structure pattern.

Further, in the above-described exposure method, since a plurality of tracks are simultaneously drawn, the time required for exposure can be greatly reduced as compared with the method of drawing one track at a time at the same linear velocity. Therefore, by employing the above-described exposure method, the productivity can be significantly improved. In general, electron guns often change with time, such as fluctuations in electron beam intensity, when emission of an electron beam is continued for a long period of time. Therefore, there is also an advantage that the influence of the aging of the electron beam can be reduced.

Generally, electron beam deflection is performed by inputting a digital signal corresponding to a desired deflection to a digital-to-analog converter, and outputting the output from the digital-to-analog converter corresponding to the digital signal to deflect the electron beam. This is performed by supplying the beam to the beam deflection electrode.

In an electron beam lithography system for semiconductor lithography, deflection over a long distance of usually several tens of μm must be performed with high accuracy. And the number of pits of the input digital signal is large (12 to
14 bits).

However, such a digital-to-analog converter has a long settling time (a time until the output voltage reaches a set value). Therefore, in an electron beam lithography apparatus for semiconductor lithography, the actual deflection speed is limited by the digital-to-analog converter. Is limited by the settling time. Specifically, a digital-to-analog converter that satisfies the above-mentioned requirements requires a settling time of about 50 nsec or more even at the latest, and if such a digital-to-analog converter is used,
In applying the present invention, deflection at a high speed as desired cannot be performed.

On the other hand, when the present invention is applied to deflect the electron beam over a plurality of tracks, the amplitude may be very small. For example, if the track pitch is 0.2 μm, even if the electron beam is deflected over five tracks, the amplitude may be at most 1 μm. As described above, when the electron beam is deflected over a plurality of tracks by applying the present invention, the amplitude may be very small. Therefore, as a digital-to-analog converter, the output is about several volts and the number of bits of the input digital signal is 8 to About 10 bits can be used. And with such a digital-to-analog converter, the settling time is very short,
By using such a digital-to-analog converter, it is possible to deflect an electron beam at a high speed of several hundred MHz.

In other words, when the present invention is applied to deflect the electron beam over a plurality of tracks, if the amplitude of the electron beam is kept to a minimum, there is a margin in the performance required for the digital-analog converter. This also means that the deflection speed of the electron beam and the positional accuracy of the electron beam incident on the electron beam resist can be improved. Therefore, when the present invention is applied to deflect the electron beam over a plurality of tracks, it is preferable to keep the amplitude to a necessary minimum (for example, about 1 μm), whereby the electron beam deflection speed,
It is possible to improve the positional accuracy of the electron beam incident on the electron beam resist.

Next, a description will be given of a recording medium substrate and a recording medium manufactured using a master for manufacturing a recording medium manufactured by employing the above-described exposure method.

The recording medium substrate can be obtained, for example, by injection molding a resin material or the like using the recording medium manufacturing master prepared as described above as a mold. That is, by injection molding a resin material or the like using the above-mentioned master for recording medium production as a mold, a substrate for recording medium on which the concavo-convex pattern formed on the original for recording medium production is transferred is produced. Specifically, for example, as shown in FIG. 13, a recording medium substrate 40 in which a groove 41 is formed on a signal recording surface 40a, and as shown in FIG. 14, a pit 51 is formed on a signal recording surface 50a. The recording medium substrate 50 is manufactured.

The method for producing the recording medium substrate on which the concavo-convex pattern formed on the recording medium production master is transferred may be a method other than injection molding. For example, a resin material heated and softened may be used. A so-called thermal transfer method may be used in which a concave / convex pattern is transferred by pressing a master for producing a recording medium onto the recording medium. Also, after applying the photopolymer on the master for the production of the recording medium, the photopolymer is cured by irradiating ultraviolet rays, and then the photopolymer is peeled off, thereby producing a substrate for the recording medium on which the concave and convex pattern is transferred. A so-called 2P method may be used.

The recording medium has a recording layer required for recording and reproducing information signals formed on the recording medium substrate manufactured as described above, and further comprises an ultraviolet curable resin or the like on the recording layer. It is produced by forming a protective layer.
As the recording medium produced in this way, specifically,
An optical disk on which recording and / or reproduction is performed optically is exemplified. Hereinafter, such an optical disk will be described in more detail.

As shown in FIG. 15, the optical disc 61
It has a disk substrate 62 which is a substrate for a recording medium manufactured by the manufacturing method as described above, and a recording layer is formed on the disk substrate 62. here,
The optical disc 61 has a signal recording area 63 in which an information signal is recorded.
For example, in the case of the land address format as shown in FIG. 19, the groove and the pit row are formed in a double spiral shape, and in the case of the intermittent wobble format as shown in FIG. The groove and the wobbling groove are formed in a double spiral shape.

In this optical disk 61, for example, one surface of a disk substrate 62 is used as a signal recording surface on which grooves and pit rows are formed, and the other surface is used as a reading surface. That is, when a signal is reproduced from the optical disk 61, the side on which no groove or pit row is formed is set as a reading surface,
Laser light is emitted from the side of the reading surface.

In the optical disc 61, for example,
The land between the grooves is a recording area, and the groove is a tracking light reflection area. Such a system is called a land recording system. Further, for example, a groove may be used as a recording area, and a land between the grooves may be used as a tracking light reflection area. Such a method is called a groove recording method. Further, for example, both the groove and the land may be used as the recording area. Such a method is called a land / groove recording method. In the land / groove recording method, the recording density can be increased to about twice that of land recording or groove recording.

Incidentally, the optical disk 61 may be a read-only optical disk in which only a pit string indicating an information signal is formed in advance without forming a groove. In this case, the pit row formed on the signal recording surface 62a is also used as a tracking diffraction grating. That is, in a read-only optical disc, tracking control is performed based on diffracted light from a pit row indicating an information signal. However, also in a read-only optical disc, it is possible to form a groove or land and use the groove or land as a tracking light reflection area.

In the optical disk 61, the disk substrate 6
On the signal recording surface of No. 2, a recording layer necessary for recording and / or reproduction is formed. Specifically, when the optical disk 61 is a phase change optical disk, a recording layer including a phase change recording film and a reflection film is formed, and
When 1 is a magneto-optical disc, a recording layer including a perpendicular magnetic recording film and a reflective film is formed, and when the optical disc 61 is a read-only optical disc in which a pit row indicating an information signal is formed in advance. Is formed with a recording layer made of a reflective film or the like. On the optical disk 61, a protective layer made of an ultraviolet curable resin or the like is formed on these recording layers.

When reproducing an information signal from such an optical disk 61, a laser beam from an optical pickup is irradiated onto the optical disk 61 from the reading surface side while rotating the optical disk 61, and the reflected light is detected. .
When the optical disk 61 is a phase-change optical disk or a read-only optical disk in which a pit string indicating an information signal is formed in advance, the information signal is detected by detecting a change in the intensity of the reflected light. Reproduce. When the optical disk 61 is a magneto-optical disk, the information signal is reproduced by detecting a change in the Kerr rotation angle of the reflected light.

On the other hand, when an information signal is recorded on the optical disk 61, a laser beam from an optical pickup is applied to the optical disk 61 from the reading surface side while rotating the optical disk 61. At this time, when the optical disk 61 is a phase-change type optical disk, a laser beam having been subjected to intensity modulation corresponding to an information signal to be recorded is irradiated. Thereby, an information signal is recorded in the area irradiated with the laser light. When the optical disk 61 is a magneto-optical disk, a region where an information signal is to be recorded is irradiated with a laser beam, and a magnetic field is applied to the region irradiated with the laser beam. At this time, intensity modulation is performed on the laser light or the magnetic field in accordance with the information signal to be recorded. As a result, an information signal is recorded in a region where the magnetic field is applied and the laser beam is irradiated.

[0112]

As described above in detail, according to the present invention, a master for producing a recording medium, which has conventionally been manufactured using a plurality of exposure beams, can be formed by using only one exposure beam. It can be manufactured. Therefore, according to the present invention, an electron beam lithography apparatus capable of making the spot diameter smaller than that of a laser beam for manufacturing a master for manufacturing a recording medium which has been conventionally manufactured using a plurality of exposure beams. Etc. can be used. Therefore, according to the present invention, it is possible to manufacture a recording medium manufacturing master corresponding to a recording medium with higher recording density.
Further, according to the present invention, since it is possible to manufacture such a master for manufacturing a recording medium, a recording medium having a higher recording density, and a substrate for a recording medium corresponding to such a recording medium Can also be provided.

[Brief description of the drawings]

FIG. 1 is a view showing a glass master.

FIG. 2 is a view showing a state where an electron beam resist is applied on a glass master.

FIG. 3 is a view showing an exposure step of exposing an electron beam resist.

FIG. 4 is a diagram showing a state in which an uneven pattern corresponding to a groove is formed on an electron beam resist.

FIG. 5 is a diagram showing a state in which a concavo-convex pattern corresponding to a pit row is formed on an electron beam resist.

FIG. 6 is a view showing a state in which a plating layer is formed on an electron beam resist.

FIG. 7 is a diagram illustrating a configuration example of an electron beam drawing apparatus.

FIG. 8 shows that the electron beam is subjected to intensity modulation,
FIG. 3 is a diagram illustrating a state in which a latent image is simultaneously formed over two tracks by deflecting an electron beam.

9 is a diagram showing a modulation signal and a deflection signal corresponding to the exposure pattern shown in FIG.

FIG. 10 is a diagram showing a state in which a latent image is simultaneously formed over three tracks by performing intensity modulation on an electron beam and deflecting the electron beam.

FIG. 11 is a diagram showing a state in which a latent image corresponding to a straight groove and a latent image corresponding to a wobbling groove are simultaneously formed by performing intensity modulation on an electron beam and deflecting the electron beam. is there.

FIG. 12 shows an exposure pattern and an exposure pattern when a latent image corresponding to a pit row is simultaneously formed over two tracks by performing intensity modulation on the electron beam and deflecting the electron beam. FIG. 3 is a diagram showing a modulation signal and a deflection signal corresponding to FIG.

FIG. 13 is an enlarged view showing a portion where a groove is formed in a recording medium substrate manufactured by applying the present invention.

FIG. 14 is an enlarged view showing a portion where a pit row is formed in a recording medium substrate manufactured by applying the present invention.

FIG. 15 is a perspective view showing an example of an optical disk manufactured by applying the present invention.

FIG. 16 is a diagram showing an example of a laser cutting device.

FIG. 17 is a diagram showing a single spiral structure.

FIG. 18 is a diagram showing a double spiral structure.

FIG. 19 is a diagram showing a land address format.

FIG. 20 is a diagram showing an intermittent wobble format.

FIG. 21 is a diagram showing an example of a laser cutting device capable of exposing a photoresist with two exposure beams.

[Explanation of symbols]

10 glass master, 11 resist for electron beam, 15
Groove pattern, 17 pit row pattern, 21
Electron beam emitting part, 22 rotation drive mechanism, 23
Translation mechanism, 24 anti-vibration table, 25 electron gun, 26 condenser lens, 27 blanking electrode, 28 aperture, 29 beam deflection electrode,
30 Focus adjustment lens, 31 Objective lens,
32, 33 case

Claims (8)

[Claims] 1. A method for manufacturing a master for manufacturing a recording medium having a predetermined uneven pattern formed along a track, comprising irradiating an exposure beam along a track to a photosensitive layer formed on a support. Exposing the photosensitive layer to form a latent image corresponding to a predetermined concavo-convex pattern on the photosensitive layer, and developing the latent image formed on the photosensitive layer by the exposing step to form a photosensitive layer. A developing step of forming a concave and convex pattern on the photosensitive layer by transferring the concave and convex pattern formed on the photosensitive layer by the developing step, thereby producing a recording medium manufacturing master having a predetermined concave and convex pattern formed thereon. In the above-mentioned exposure step, the exposure beam is deflected over a plurality of tracks, and the exposure beam is incident on the photosensitive layer only at locations on each track to be exposed. By the exposure beam intensity modulation so that method of manufacturing a recording medium manufacturing master, characterized in that simultaneously latent image formation over a plurality of tracks. 2. In the exposure step, a latent image corresponding to a groove formed along a track is formed, and at the time of forming the latent image, an exposure beam is formed so that at least a part of the groove meanders. 2. The method according to claim 1, wherein the deflection operation and the intensity modulation are performed. 3. A recording medium manufacturing master on which a predetermined uneven pattern is formed along a track, wherein a photosensitive layer formed on a support is irradiated with an exposure beam along the track. By exposing the photosensitive layer to form a latent image corresponding to a predetermined concavo-convex pattern on the photosensitive layer, deflecting the exposure beam over a plurality of tracks when forming the latent image, and exposing each track. An exposure step of simultaneously forming a latent image over a plurality of tracks by modulating the intensity of the exposure beam so that the exposure beam is incident on the photosensitive layer only at a portion to be exposed; Developing a concavo-convex pattern on the photosensitive layer by developing A master for manufacturing a recording medium, wherein the master is manufactured through a transfer step of manufacturing a master for manufacturing a recording medium on which a predetermined concavo-convex pattern is formed by transferring. 4. A predetermined concavo-convex pattern formed by transferring the concavo-convex pattern formed on the photosensitive layer, the groove pattern corresponding to a groove formed along a track, wherein the groove pattern is at least partially formed. The master for producing a recording medium according to claim 3, wherein the master is formed to meander. 5. A recording medium substrate produced using a recording medium production master on which a predetermined uneven pattern is formed along a track, wherein the recording medium production master is formed on a support. The photosensitive layer is exposed by irradiating the exposed photosensitive layer with an exposure beam along a track to form a latent image corresponding to a predetermined concavo-convex pattern on the photosensitive layer and to form the latent image. By simultaneously deflecting the exposure beam over a plurality of tracks and simultaneously modulating the intensity of the exposure beam so that the exposure beam is incident on the photosensitive layer only at the portion to be exposed on each track, a latent image can be simultaneously formed over a plurality of tracks. And developing the latent image formed on the photosensitive layer by the exposure step to form an uneven pattern on the photosensitive layer. And a step of transferring the concavo-convex pattern formed on the photosensitive layer by the developing step, and a transfer step of manufacturing a recording medium manufacturing master having a predetermined concavo-convex pattern formed thereon. For recording media to be used. 6. The recording medium substrate according to claim 5, having a groove formed along the track, wherein at least a part of the groove is meandering. 7. A recording medium having a recording layer formed on a recording medium substrate produced using a recording medium production master having a predetermined concavo-convex pattern formed along a track. The production master exposes the photosensitive layer by irradiating the photosensitive layer formed on the support with an exposure beam along the track, and forms a latent image corresponding to a predetermined concavo-convex pattern on the photosensitive layer. In forming and forming the latent image, the exposure beam is deflected over a plurality of tracks, and the intensity of the exposure beam is modulated so that the exposure beam is incident on the photosensitive layer only at a portion to be exposed on each track. Thereby, an exposure step of forming a latent image simultaneously over a plurality of tracks, and by developing the latent image formed on the photosensitive layer by the exposure step, A developing step of forming a concavo-convex pattern on the photosensitive layer, and a transfer step of transferring the concavo-convex pattern formed on the photosensitive layer by the above-described developing step, thereby producing a recording medium manufacturing master having a predetermined concavo-convex pattern A recording medium characterized by being produced through the process. 8. The recording medium according to claim 7, wherein the recording medium manufacturing substrate has a groove formed along a track, and at least a part of the groove is meandering.