JPH01188332A - Molding stamper for information record carrier and its manufacture - Google Patents

Abstract

PURPOSE:To enable manufacture of an information record carrier which is free from facial deflection and distortion and has favorable S/N, by forming a material of a stamper as glass. CONSTITUTION:A negative type photoresist 8 is applied uniformly onto the surface of a II type quartz glass board 7 polished highly accurately. Then a guide groove is recorded on the photoresist 8 by making use of laser rays 9 and continuously a desired pattern is obtained by development treatment. Dry etching is performed on the board within CF4 gas plasma 10 and it is suspended at a desired depth. The remaining photoresist 8 is removed by performing ashing with oxygen (O2) and a stamper made of glass is obtained further. A disk board is made of the stamper through a 2P method, to which a recording film and protective film are applied and an information record carrier is obtained. As an adhesive process at the time of making of the stamper becomes unnecessary, in an optical disk made by a method like this, the title carrier becomes a matter where a distortion or facial deflection is little.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a molded stamper for an information recording carrier and a method for manufacturing the same, and more particularly to an optical disc on which an information signal is optically recorded;
The present invention relates to a molding stamper for information recording carriers such as magneto-optical disks and a method for manufacturing the same.

BACKGROUND OF THE INVENTION Generally, information recording carriers such as optical disks and magneto-optical disks are formed by making a replica disk of ultraviolet curing resin, thermosetting resin, etc. from a stamper, and coating the disk with a recording film, a protective film, etc.

Conventionally, the molding stamper for this type of information recording carrier has been
It was manufactured by the method shown in the figure.

First, for example, a positive type photoresist 2 is uniformly applied onto a highly precisely polished glass substrate (Fig. 4(a)).
→(b)).

Next, a pattern is recorded on the photoresist 2 using a laser beam 3, and then a desired pattern is obtained by a development process (
Figure 4 (C) → (d)). Next, a metal 4 such as nickel or silver is deposited on the patterned resist 2 by vapor deposition, sputtering, electroless plating, etc. to make it conductive (
Figure 4(e)).

On top of this, add 100 to 300 metals such as nickel.
Electroforming is performed to the extent of μm (Fig. 4(f)). After this is peeled off and the photoresist 2 is removed, a backing substrate 6 made of highly precisely polished glass, metal, resin, etc. is bonded with an adhesive (FIG. 4 (Q)→(h)). Alternatively, the photoresist 2 is removed immediately after the lining process is performed, and then peeled off to remove the photoresist 2 (FIG. 4(1)→(j)). There is a way.

Problems to be Solved by the Invention However, since the stamper produced by the conventional method uses an adhesive such as epoxy in the processing (step (h) or (i) in FIG. 4), the backing base 6 and electroforming stamper 5
Air bubbles can easily enter between the 2P (Photo
There was a problem in that during molding by the lymarization method or the like, traces of air bubbles were transferred to the disk side, causing distortion.

Also, when bonding the lining base using the process shown in Figure 4 (Q) → (h), the lining base! 6 and the electroforming stamper 5 with good parallelism, making it impossible to form a disk with small surface runout. Although it is easy to adhere well, there is a problem in that peeling from the glass substrate 1 is difficult.

The present invention has been made in view of the above points, and an object of the present invention is to provide a stamper for an information recording carrier that can produce an information recording carrier with no vibration or distortion and a good S/N ratio, and a method for manufacturing the same. .

Means for Solving the Problems In a molding stamper for an information recording carrier that creates an information recording carrier having an information signal pattern by placing a resin material opposite to the surface of the stamper and curing it, the material of the stamper is formed as glass. Become.

Further, the molding stamper of the information recording carrier of the present invention includes a step of polishing a glass substrate, a step of forming a resist film sensitive to beam irradiation on the glass substrate, and a step of forming a resist film that is modulated according to an information signal pattern on the resist film. A process of irradiating the beam and developing the resist film to remove the resist film in the areas irradiated with the beam or the areas not irradiated with the beam to form a resist film with a pattern corresponding to the information signal pattern. It is produced by a manufacturing method including a step of etching a glass substrate using a resist film as a mask and a step of removing the resist film.

Function The molded stamper for the information recording carrier according to the present invention is made of glass, and a pattern corresponding to the information signal is directly formed on the glass material by etching, so that a backing process such as adhesion can be omitted.

Embodiment FIG. 1 shows an explanatory diagram of the manufacturing process of a molded stamper for an information recording carrier of the present invention.

First, a negative type 7 photoresist 8 is uniformly applied onto the surface of a highly precisely polished quartz glass substrate 7 (FIG. 1(a)). Next, a guide groove is recorded on this photoresist 8 using a laser beam 9 (FIG. 1(b)), and then a desired pattern is obtained by a development process (FIG. 1(C)).
.

Next, dry etching is performed on this substrate in a CF4 gas plasma 10, and the etching is stopped at a desired depth (Fig. 1(d)
)). Furthermore, the remaining photoresist 8 is removed with oxygen (02
) to obtain a glass stamper (FIG. 1(e)).

A disk base was prepared from this stamper by the 2P method or the like, and a recording film and a protective film were coated to obtain an information recording carrier such as an optical disk. The optical disc produced by the method described above does not require an adhesion process or the like when the stamper is produced, and therefore has less distortion and surface wobbling.

In this example, a pattern was created using a laser beam on a negative type resist as a method of obtaining a pattern of guide grooves on a stamper, but this is different from the conventional process, that is, a process using a positive type resist, and a process using a Ti on recording. This is to maintain compatibility, but is not limited to this. Another possible method is to irradiate ultraviolet rays through a chrome mask or the like in which guide grooves are patterned in advance and expose the photoresist as a pattern.

In addition, in order to obtain high-quality disks, especially disks with good S/N, we focused on the material of the glass substrate and dry-etched glasses with various composition ratios with CF4 gas to reduce the surface roughness of the etched surface. Figure 2 shows the results of examining the condition.

As shown in FIG. 2, ■-type quartz, ■-type quartz, and borosilicate glass have high etching rates and rough surfaces. Also,
Soda lime glass, soda aluminosilicate glass, and barium borosilicate glass have low etching rates and less surface roughness. That is, there is a correlation between the etching rate and surface roughness, such that the higher the etching rate of the glass, the greater the surface roughness.

Considering this by paying attention to the composition ratio of the glass, the more concavities there are in 5fOz and B2O3 contained in the glass, the thicker the etching rate (NazO, NazO, etc.).

K20. It can be seen that the higher the amount of MQO, cao, Ae20x, and BaO, the lower the etching rate. Third
The figure shows that the vapor pressure of fluoride, the main glass component, is 10 t.
This figure shows the temperature at which fluoride becomes orr, and is quoted from page 555 of the Chemical Handbook, Basic Edition (edited by the Chemical Society of Japan, 1975). Produces a large etching rate,
Nap, @20. It can be seen that the higher the temperature of the fluoride, such as Ae, 203, produces a smaller etching rate.

From the above considerations, the etching rate of glass is determined by the composition ratio of the constituent materials, and it is considered that glass having an etching rate of 60% or less of quartz is suitable for obtaining a disk with good S/N.

In the above embodiment, the optical disk produced using soda lime glass as the stamper has no distortion, has very small surface runout, and has a very good S/N ratio.

Furthermore, optical discs made with a stamper using a soda aluminosilicate glass substrate and CHF 3 gas plasma have little distortion, very little surface runout, and very good S/N ratios. .

Note that in the above examples, CF4 was used as the reaction gas.

Although CHF3 was used, other gases may be used as long as they are fluorine-based gases that are reactive with glass; for example, C2
F6, C3F8, NF3, and mixed gases thereof may also be used.

Further, in order to improve the tracking characteristics of the disk, the guide groove may be tapered.
It is also possible to introduce a method of tapering the resist by simultaneously etching the resist during the dry etching of the glass, as shown in Japanese Patent No. 1-26952.

In addition, since this stamper can be made transparent, it is also possible to perform 2P molding by irradiating ultraviolet rays through the stamper (Japanese Patent Application Laid-Open No. 15235/1982). disk·
It is also effective when the base of the disc to be molded, such as a video disc, contains a pigment.

Effects of the Invention As described above, according to the present invention, there is no need for backing treatment, so there is no need for an adhesion process, and there is no need for air bubbles to enter, making it possible to create a stamper with less distortion or wobbling. Since the recording carrier can be created and the process can be shortened, the stamper creation time can be shortened and automation can be facilitated.Furthermore, it can be used to mold information recording carriers by the 2P method of irradiating ultraviolet rays etc. through the stamper. Right features.

[Brief Description of the Drawings] Fig. 1 is a diagram for explaining one embodiment of the stamper manufacturing method of the present invention, and Fig. 2 shows the results of glass with various composition ratios when dry etched with CF4 gas. FIG. 3 is a diagram showing the state of roughness of the surface to be etched, FIG. 3 is a diagram showing the temperature at which the vapor pressure of fluoride becomes 10 torr, and FIG. 4 is a diagram for explaining an example of a conventional stamper manufacturing method. . 7...Glass 5513.8...Photoresist, 9
...Laser light, 10...Gas plasma. Patent applicant: Japan Victor Co., Ltd. Representative: Patent attorney: Tadahiko Ito
':, i'i'j'. Same patent attorney Kaneyuki Matsuura Figure 1 (e) Hi] Kugotonyyo 7 Figure 4 (a) 口======Bottom-1 ↓

Claims (7)

[Claims] (1) In a molding stamper for an information recording carrier in which an information recording carrier having an information signal pattern is produced by placing a resin material opposite the surface of a stamper having an inverted pattern of an information signal pattern and curing the material, the material of the stamper is glass. A molded stamper for an information recording carrier, characterized in that the stamper is formed by forming the stamper as a molded stamper. (2) The molded stamper for an information recording carrier according to claim 1, wherein the material of the stamper is glass having an etching rate of 60% or less of quartz. (3) The information recording carrier molding stamper according to any one of claims 1 to 2, wherein the inversion pattern has a tapered shape. (4) A step of polishing a glass substrate, a step of forming a resist film sensitive to beam irradiation on the glass substrate, and a step of irradiating the resist film with the beam modulated according to the information signal pattern. and developing the resist film to remove the resist film in the portions irradiated with the beam or the portions not irradiated with the beam, and form the resist film in a pattern corresponding to the information signal pattern. 2. The method of manufacturing a molded stamper for an information recording carrier according to claim 1, comprising the steps of: etching the glass substrate using the resist film as a mask; and removing the resist film. (5) The method for manufacturing a molded suntapa of an information recording carrier according to claim 1, wherein the material of the glass base is glass having an etching rate of 60% or less of quartz. (6) The step of irradiating the beam onto the resist film is a step of exposing the resist film through a mask in which the information signal pattern has been patterned in advance. 5. The method for producing a molded suntapa of an information recording carrier according to 5. (7) The step of etching the glass substrate using the resist film as a mask is characterized in that the information signal pattern is formed into a tapered shape by etching while retracting the resist film. 7. A method for producing a molded stamper for an information recording carrier according to claim 6.