JP3465301B2 - How to make a master for making optical discs - Google Patents

Description

Detailed Description of the Invention

[0001]

The present invention relates to a CD, VD (LD),
The present invention relates to the manufacture of an optical disk producing master for producing optical disks such as MDs (minidiscs), WOs and MOs, that is, an optical disc producing master for producing a so-called nickel stamper.

[0002]

2. Description of the Related Art Conventionally, a technique of using an injection molding machine or a 2P (Ph
oto-Polymer) method is used. A nickel stamper is used as a mold for an injection molding machine or a device to which the 2P method is applied.

As is well known, when forming a nickel stamper, first, a photoresist is applied to a glass master, and a signal pattern is exposed and recorded by a laser beam spot while rotating the glass master with a register layer. Form an image.

Next, after developing this, the surface is made into a conductor,
That is, metallization is performed, and nickel plating is performed on the metallized layer.

A nickel master is prepared by peeling and washing the nickel plating layer from the glass master having the nickel plating layer formed thereon.

This nickel master can be used as the above-mentioned nickel stamper. However, when trying to make a large number of optical disks, a nickel mother is made for one nickel master, and the nickel mother is made from the nickel mother. A nickel stamper was prepared by performing a so-called plating reversal process to prepare a plurality of nickel stampers.

[0007]

However, in the above-mentioned conventional technique, when the nickel stamper is formed, the nickel master needs to be subjected to the peeling treatment (passivation), the metallizing treatment, and the peeling washing treatment of the nickel plating layer. Therefore, the signal surface of the nickel master may be damaged during the process or during the handling.

When the nickel master is scratched, the above-mentioned glass master is coated again with a photoresist, and while rotating, a signal pattern is exposed and recorded by a laser beam spot to form a latent image. Since I had to start over from the process, in such a case,
There was a problem that it was very troublesome.

Further, when the nickel stamper is produced from the nickel master, the nickel stamper must be produced one by one, which is a troublesome problem. In other words, there was also a request to create many nickel stampers at once.

Further, for example, a signal pattern forming exposure device for forming a signal pattern of a CD having a diameter of 12 cm and a track pitch of 1.4 μm on a glass master having a resist layer is used as another optical disc, for example, a track pitch of 0.9 to 1.1.
There was a request to use it for the MD (φ6.4 cm) of μm. These demands eventually lead to cost reduction.

The present invention has been made in consideration of the above problems, and enables the nickel master (nickel stamper) to be easily produced and a plurality of nickel masters can be produced at one time. Provided is a method for producing a master for producing an optical disc, which enables a pattern forming exposure apparatus to be used also for MD.

[0012]

According to the present invention, for example, as shown in FIGS. 3, 5 and 6, a metal layer 2 is formed on a glass master 1 and a resist layer 3 is formed on the metal layer 2. The process of forming the glass master 5 with the surface resist layer / inner metal layer, and forming the enlarged signal pattern on the surface resist layer 3 of the glass master 5 with the surface resist layer / inner metal layer, and then forming the resist layer 3 The metal layer 2 is exposed by developing to remove the resist layer 3 on the portion where the signal pattern is formed, and the exposed metal layer 2 is removed by etching using the remaining resist layer 3 as a mask. After the resist layer 3 is removed, an optical master 11 is prepared, and after the optical master 11 is used to expose and record a reduction signal pattern on the resist-coated glass master 23 using the imaging optical system 25. , A process of developing a glass master disk 23 with a resist layer on which a pattern has been exposed and recorded, further forming a plating layer after conducting a surface conductor treatment, and peeling and cleaning the formed plating layer to prepare a master disk for optical disk production. And have.

Further, according to the present invention, in the process of producing a master for optical disk production using the optical master 11, the optical master 11 is used to reduce the glass master with resist layer 23 using the imaging optical system 25. When the signal pattern is exposed and recorded, a plurality of optical disc forming masters are created by exposing and recording a plurality of different positions on the glass master with a resist layer 23.

[0014]

According to the present invention, an optical master 11 similar to the reticle used in the stepper device 24 for manufacturing a so-called semiconductor integrated circuit is prepared, and the optical master 11 is used to form a glass master with a resist layer. A signal pattern is exposed and recorded on 23, and a master for forming an optical disk, that is, a nickel master (nickel stamper) is prepared from this exposed and recorded glass master 23 with a resist layer. For this reason, when the nickel master (nickel stamper) is created using the optical master 11, the optical master 11 only needs to perform exposure recording, that is, to allow light to pass therethrough. The probability of being scratched is considerably lower than that of the conventional technique of performing the peeling process. Further, once the optical master 11 is created, the passivation step is not required, so that the nickel master (nickel stamper) can be easily created. In the process of making the optical master 11, the signal pattern is enlarged and exposed and recorded, and in the process of making the optical disc making master, the enlarged signal pattern is reduced and exposed and recorded by using the imaging optical system 25. The pattern is highly accurate.

When a signal pattern is exposed and recorded on the resist-coated glass master 23 using the optical master 11, a plurality of exposures are recorded by a so-called step-and-repeat technique. A sheet of nickel master (nickel stamper) can be created.

Furthermore, when exposure recording is performed using the optical master 11, for example, if a 0.9 / 1.2 times reduction optical system is used, for example, the optical master 11 for MD is used as C
It can be created by the D signal pattern exposure recording apparatus 10 (see FIG. 4).

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method for producing an optical disk producing master according to the present invention will be described below with reference to the drawings.

FIG. 1 shows an optical master forming process. FIG. 2 shows an optical disc making master making process for making an optical disc making master using the optical master made in the optical master making process shown in FIG.

Therefore, the optical master making process shown in FIG.
Description will be given in the order of the steps for producing a master for producing an optical disc shown in FIG.

First, as shown in FIG. 3, a light-transmissive glass master 1 is prepared, and a metal layer 2 of chromium, for example, is formed on one surface of the glass master 1 (step S1). The metal layer 2 may be formed to have a thickness that blocks ultraviolet light, which will be described later. The metal layer 2 can be formed using a vapor deposition technique or a sputtering technique.

Next, a resist is applied on the metal layer 2 of the glass master with a metal layer thus prepared to form a resist layer 3 to form a glass master 5 with a surface resist layer and an inner metal layer. (Step S2). As will be described later, the resist layer 3 is used for etching the metal layer 2.

Next, as shown in FIG. 4, a known signal pattern exposure recording apparatus 10 (FIG. 4 shows the overall structure of the signal pattern exposure recording apparatus) for the glass master 5 having a surface resist layer / inner surface metal layer. ), And a signal pattern is formed on the resist layer 3 of the glass master 5 having the surface resist layer and the inner surface metal layer (step S3). In this case, first, the glass master 5 with the surface resist layer / inner surface metal layer is fixed on the mounting base 6 which can be rotated in the direction of arrow P. Next, while rotating the mounting table 6 in the direction of arrow P, the optical system 7 for irradiating the laser beam L to the resist layer 3 is moved in the direction of radius R, so that the resist layer 3 has a concentric or spiral signal pattern. Latent image can be formed. The laser light L emitted from a laser light source device 8 having a laser light source, an optical modulator, etc. is reflected by a mirror 9 constituting an optical system 7 to form a resist layer 3.
I'm trying to irradiate the top.

In this embodiment, the master for producing the optical disc to be finally produced, that is, the nickel master (nickel stamper) is adapted to MD (track pitch 0.9 mm). In the signal pattern exposure recording process of S3, since the existing CD signal track exposure recording device 10 (with a track pitch of 1.4 mm) is used, the signal pattern is exposed and recorded by enlarging it. Therefore, by reducing the size for MD in a later step, it is possible to easily form a pattern with high accuracy, that is, a so-called fine pattern.

Next, the glass master 5 with the surface resist layer and the inner metal layer on which the signal patterns are exposed and recorded is developed (step S4).

By this development, it becomes possible to easily remove the resist layer 3 in the portion where the signal pattern is formed by irradiating the laser beam L, and in the removed portion, the metal layer 2 corresponding to the signal pattern is formed. Exposed.

Then, the resist layer 3 serves as a mask by etching, and only the exposed metal layer 2 is etched and removed, and the surface of the glass master 2 is exposed at that portion (step S5).

Then, the surface resist layer after etching
The glass master 5 with the inner metal layer is washed to remove the resist layer 3. As a result, an optical master 11 as shown in FIG. 5, a so-called mask (corresponding to a reticle in a semiconductor stepper device) is created (step S).
6). In this optical master disk 11, a signal pattern SP obtained by enlarging a signal pattern of MD by the metal layer 2 is patterned on the glass master disk 1. The actual signal pattern SP is formed on the exposed portion of the glass master 1 between the metal layers 2.

Next, a process of producing a master for optical disc production, that is, a nickel master (nickel stamper) using the optical master 11 thus produced will be described with reference to FIG.

First, a plurality of masters for optical disk production to be finally produced at a time are used (in this embodiment, 4).
A relatively large glass master 21, and a resist layer having a thickness corresponding to λ / 4 of the disc reading wavelength (where λ is the wavelength of the reading laser light) is prepared on the glass master 21. By forming 22 by coating, a glass master 23 with a resist layer is created (FIG. 2, step S1).
1). If you want to make four discs at a time, you can use a glass master disc for CDs, but by using a glass master disc for VD (LD), you can create a larger number of master discs for optical disk production. Can be created.

Next, the glass master 23 with the resist layer
The stepper device 24 (FIG. 6 shows the structure of the stepper device as a whole. In FIG. 6, the upper and lower sides of the double wavy line are drawn at different viewing positions for easy understanding. Fixed on an XY stage (not shown). An imaging optical system 25, which is a reduction optical system (reduction ratio in this embodiment is 0.9 / 1.4 times), is arranged above the resist-coated glass master 23 fixed on the XY stage. It is fixed. Next, the optical master 11 created by the above steps S1 to S6
Are fixed between the ultraviolet lamp 26 that generates the ultraviolet light Luv and the imaging optical system 25. In this way, the optical master 11 and the glass master with resist layer 23 are set in the stepper device 24 (step S12).

In the set state, the same latent image 27 is formed a plurality of times on the resist layer 22 by the ultraviolet light Luv imaged by the imaging optical system 25 while the X-Y stage is being fed at a constant size (see FIG. 6 example). Then, exposure recording is performed four times (step S1)
3). That is, a plurality of latent images 27 are formed by the step-and-repeat method. The size of each latent image 27 is reduced by the imaging optical system 25 to a size corresponding to MD. Therefore, the track pitch on the signal pattern on this latent image is 0.9 μm, which is equal to the track pitch of the actual MD.

The glass master 23 with a resist layer on which a plurality of latent images 27 are exposed and recorded is removed from the stepper device 24. Then, a nickel master (nickel stamper) is formed by a well-known nickel master (nickel stamper) forming technique described below. That is, the glass master 23 with a resist layer on which the latent image 27 is exposed and recorded is subjected to a surface conductorizing process, that is, a metallizing process (step S15) after the developing process (step S14), and further a plating process (step S16). ), A nickel plating layer having a thickness of 300 μm, for example, is formed on the metallized layer. Finally, the nickel plating layer is peeled off from the glass master 21 on which the nickel plating layer is formed, and the resist layer 22 is washed and removed, so that a plurality of nickel masters (4 nickel stampers in the example of FIG. 6) are once removed. Can be created.

By using these nickel masters as nickel stampers, a desired optical disk, in this case, MD (actually, resin disk, this resin disk, dielectric An MD as an optical disc is completed by forming a body film, a magnetic film, a reflection film protective film, etc.). It should be noted that when the optical disc is produced, four nickel discs are used at a time by using the nickel stamper, and when a resin disc which is a master disc for producing the optical disc is to be produced, four discs are separated from the peeled nickel plating layer. The nickel master can be used without disconnecting it.

As described above, according to the above-described embodiment, the optical master 11 as a mask is prepared, and the optical master 1 is manufactured.
1 is used to form a latent image 27 by exposing and recording a signal pattern a plurality of times on a glass master disk 23 with a resist layer by a stepper device 24, and from this, a master disk for optical disk production, that is, a nickel master (nickel stamper) is created. I have to. In this case, when the nickel master (nickel stamper) is created using the optical master 11, the optical master 11 only needs to pass the exposure recording, that is, the ultraviolet light Luv. The probability of scratches on the surface 11 is considerably reduced as compared with the conventional technique in which the peeling process by so-called plating inversion is performed. In practice, the optical master 11 can be used almost permanently. Further, once the optical master 11 is created, the passivation step is not required, so that the nickel master (nickel stamper) can be easily created.

Further, when the optical master 11 is used to record and record the signal pattern on the glass master with a resist layer 23, the exposure is recorded a plurality of times by the so-called step-and-repeat technique. Multiple nickel masters (nickel stampers) can be created on.

Furthermore, when the optical master 11 is used for exposure recording, the 0.9 / 1.4-fold reduction optical system 25 is used, so the optical master 11 for MD is used for CD. Can be created by the signal pattern exposure recording apparatus 10. Further, when higher precision is required for an optical disc as a product, a signal pattern exposure recording apparatus for VD is used instead of the signal pattern exposure recording apparatus for CD, and an imaging optical system is used. The signal pattern exposure recording apparatus may perform enlarged recording according to a reduction rate of 25 (the reduction rate can be variable).

The present invention is not limited to the above-mentioned embodiments, and it goes without saying that various configurations can be adopted without departing from the gist of the present invention.

[0038]

As described above, according to the present invention,
An optical master similar to a reticle used for a stepper device for creating a so-called semiconductor integrated circuit etc. was created, and a signal pattern was exposed and recorded on a glass master with a resist layer using this optical master, and this exposure recording was performed. A master for optical disk production, that is, a nickel master (nickel stamper) is prepared from a glass master with a resist layer. For this reason, when a nickel master (nickel stamper) is created using the optical master, the optical master simply needs to perform exposure recording, that is, to allow light to pass therethrough, and thus scratches on the optical master. The probability of sticking is considerably smaller than that in the conventional technique of performing the peeling process. Further, once the optical master is created, the passivation step is not required, so that the nickel master (nickel stamper) can be easily created. In the process of making an optical master, the signal pattern is enlarged and exposed and recorded, and in the process of making an optical disc master, the enlarged signal pattern is reduced and exposed and recorded by using an imaging optical system. It is possible to easily improve accuracy, that is, so-called fine patterning.

Further, when a reduced signal pattern is exposed and recorded by using an optical master on a glass master with a resist layer, a plurality of so-called steps are performed at different positions on the glass master with a resist layer. By using the and repeat technology to record multiple exposures, multiple nickel masters (nickel stampers) can be created at one time.

Furthermore, when exposure recording is performed using the optical master, for example, if a reduction optical system of 0.9 / 1.2 times is used, for example, the optical master for MD is used for CD. It becomes possible to create it with a signal pattern exposure recording device.

[Brief description of drawings]

FIG. 1 is a process diagram showing a process of producing an optical master in one embodiment of a method for producing an optical disc master according to the present invention.

FIG. 2 is a process drawing showing a process of making an optical disc making master using an optical master in one embodiment of a method for making an optical disc making master according to the present invention.

FIG. 3 is a cross-sectional view showing a structure of a glass master having a surface resist layer and an inner metal layer.

FIG. 4 is a diagram showing a schematic configuration of a signal pattern exposure recording apparatus.

FIG. 5 is a cross-sectional view showing a configuration of an optical master.

FIG. 6 is a diagram showing a schematic configuration of a stepper device.

[Explanation of symbols]

5 Glass master with surface resist layer and inner metal layer 10 Signal pattern exposure recording device 11 Optical master 23 Glass master with resist layer 24 stepper device 27 Latent image (of signal pattern) L laser light Luv UV light

Claims (2)

(57) [Claims] 1. A process of forming a metal layer on a glass master and forming a resist layer on the metal layer to prepare a glass master with a surface resist layer / inner metal layer, and the surface resist layer / inner metal layer. After forming an enlarged signal pattern on the surface resist layer of the glass master with a glass substrate, the resist layer is developed to remove the resist layer in the portion where the signal pattern is formed to expose the metal layer, and the remaining resist layer Using the mask as a mask to remove the exposed metal layer by etching, and then remove the remaining resist layer to make an optical master, and using this optical master to make a glass master with a resist layer.
After the reduced signal pattern was exposed and recorded using the imaging optical system, the glass master plate with the resist layer on which the signal pattern was exposed and recorded was developed, and further, the surface conductive treatment was performed, and then the plating layer was formed and formed. A method for producing an optical disc producing master having a step of producing an optical disc producing master by peeling and washing the plating layer. 2. In the process of producing a master for optical disc production using the optical master, the optical master is used to form a glass master with a resist layer using an imaging optical system.
When the reduced signal pattern is exposed and recorded, with the resist layer
The method for producing an optical disc producing master according to claim 1, wherein a plurality of optical disc producing masters are produced by exposing and recording a plurality of times at different locations on the glass original disc.