JPH0376037A - Production of information recording medium - Google Patents

Abstract

PURPOSE:To prevent the deterioration in signal characteristics and to contrive a cost reduction by consisting the production process of specific processes, thereby decreasing the number of times of electrocasting. CONSTITUTION:A substrate 31 applied with a positive type photoresist is exposed and the substrate 31 after the exposing is heated under prescribed conditions in gaseous ammonia. The front surface is irradiated with UV rays when the temp. of the glass substrate restores ordinary temp. and, thereafter, the photoresist is developed by using an alkaline developing soln., by which a master disk 33 having recorded and exposed parts 32 consisting of the projecting photoresist is obtd. The master disk is thereafter etched by using an etching liquid for wet process or is dry etched to obtain the master disk 34 having recorded signals of projecting shapes on the surface. The residues of the photoresist are removed by a plasma ashing method, etc., of O2, by which a stamper 35 is obtd. The desired disk having the recorded signals of recessed shapes is molded by using this stamper 35. The deterioration in the signal characteristics is prevented in this way and the cost reduction is contrived.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a method for manufacturing an information recording medium, and in particular to a method for manufacturing an information recording medium such as a video disc, digital audio disc, write-once disc, etc. Regarding the manufacturing method.

(Prior art) Conventionally, the production of information recording media involves the following steps (1) to
This was done by (6).

FIGS. 2A to 2E are configuration diagrams for explaining a conventional method of manufacturing an information recording medium.

Step (1) First, a positive photoresist 12 is coated on a glass substrate 11 polished sufficiently flat, and after drying, a laser beam 13 is applied.
to expose and record the desired signal.

(FIG. 2(A)) Step (2) Next, development is performed and the exposed portion is removed to form a recording signal as a concave signal 14, thereby forming a glass master 20.

((B) in the same figure) Step (3) After forming a metal thin film on this glass master 20 by a method such as electroless plating to establish electrical conductivity, by electroforming,
A metal master 21 having a convex recording signal is manufactured.
((C) in the same figure) Step (4) Furthermore, after performing a predetermined peeling treatment on this metal master 21, the same m's casting method as in step (3) is used to produce a recording signal in the same way as the glass master 20. concave mother 22
Create. (Figure (D)) Step (5) Next, in the same manner as step (4), 1,
Like the metal master 21, a stamper 23 having a convex recording signal is manufactured. (Illustration (E)) Process (6) Using this stamper 23, a disk can be molded by a press molding method in which a pellet-shaped conductive polymer compound material is pressed, or a disc can be molded using a resin such as polycarbonate. After a disk substrate having a concave recording signal is molded by injection molding, a metal reflective film such as aluminum is applied on the recording signal surface to form a disk.

As mentioned above, the recording signal is transferred (replica) a total of three times by electroforming, and the reason is as follows.

That is, since the recording surface made of the photoresist 12 is very fragile, only one metal master 21 can be produced by -degree electroforming. Therefore, Metal Master 21
In order to obtain a convex recording signal with the same shape as
Therefore, electroforming must be performed twice.

During this electroforming, it is also possible to replicate a plurality of mothers 22 from the same metal master 21 and a plurality of stampers 23 from the same mother 22.

(Problem to be Solved by the Invention) As described above, in the conventional manufacturing method of an information recording medium, it is possible to obtain many stampers 23 from one metal master, but the electroforming is performed many times. By repeating this process, the shape of the recorded signal deteriorates compared to that during exposure, and the signal characteristics of the disc deteriorate as a result of adhesion of foreign matter or cracks. Furthermore, since electroforming is performed many times, it is disadvantageous in terms of cost.

In order to solve the above problems, JP-A-54-1077
No. 05, No. 54-134603, No. 54-13604
For example, auxiliary materials such as glass substrates can be prepared by the etching method described in the following publications: A method has been proposed in which a concave exposed recording portion is created, a replica is taken by some method, and a stamper is manufactured.

In all of these methods, since the exposed and recorded portion is concave, it is necessary to take a replica or provide another layer.

(Means for Solving the Problems) The present invention has been made to solve the above problems, and includes a step of exposing a substrate coated with a positive photoresist, and a step of exposing the substrate to an atmosphere containing ammonia or amine. A process of heating the master disc inside a chamber, a process of developing it after irradiating it with a predetermined ultraviolet ray, and producing a master disc with recording signals made of convex photoresist, and dry or wet processing of the photoresist-formed surface of this master disc. Provided is a method for manufacturing an information recording medium, comprising the steps of etching to produce a stamper having a convex recording signal using the etching method described above, and forming a disk made of a desired material from the stamper. It is something to do.

(Example) FIGS. 1(a) to 1(d) are configuration diagrams showing main parts of a method for manufacturing an information recording medium according to the present invention.

An outline of the method for manufacturing an information recording medium according to the present invention will be explained below in order of steps (1) to (6).

Step (1) A positive type photoresist 12 is applied onto a substrate 31 having a smooth surface, and after drying, a desired signal is exposed to a laser beam 13 and recorded.

(FIG. 1(a)) Step (2) Next, the exposed substrate 31 is heated in ammonia gas.
Heat at 80-110°C for 30-90 minutes.

Step (3) When the temperature of the glass substrate returns to room temperature, the wavelength of 300 to 43
After irradiating the entire surface with 5 nl of ultraviolet light at an exposure dose of about 300 to 20,001 J, development is performed using an alkaline developer to obtain a master 33 having a recording exposed portion 32 made of a convex photoresist.

((b) in the same figure) Step (4) After this, etching is performed using a wet etching solution such as ferric chloride aqueous solution, hydrofluoric acid, sulfuric acid, hydrochloric acid, nitric acid, etc. By dry etching in a gas such as .5iCIa, a master disk 34 having convex recording signals on its surface is obtained.

((C) of the same figure) Step (5) Next, by removing the photoresist residue by the plasma ashing method of 02 or the like, a stamper 35 similar to the conventional stamper 23 is obtained.

((d) in the same figure) Step (6) Using the stamper 35 obtained in this way, a press molding method of pressing a pellet-shaped conductive polymer compound material, or a method of pressing a resin such as polycarbonate, etc. A desired disc having a concave recording signal is molded by an injection molding method.

Note that the substrate 31 has a thickness of several hundred μm to 31 μm, for example.
N1. of thickness of about 1. It is possible to use a metal such as Cr, Cu, or AI, or one or more metal layer of 100 to 1300 Å formed on inorganic and/or organic glass with a thickness of about 0.5 to 3II11.

In addition, as a positive photoresist, for example, MP1400 and MP13 manufactured by Sible Far East Co., Ltd.
00, and AZ1350 manufactured by Hoechst Japan Co., Ltd.
AZ1350J, etc. can be used, Ar laser,
Exposure can be performed using a Kr laser.

The main part of this example has been shown above, but next, Example 1 below
-Example 4 will be specifically explained in detail.

(Example 1) Step (1) On a flat Ni substrate 31 with a thickness of 800 μm, for example, a positive photoresist MP-1400 manufactured by Sible Far East Co., Ltd. is applied to a film thickness of 1000 to 150 μm.
Apply it so that there are 0 people and dry it well.

Step (2) Next, after recording a desired recording signal using an Ar laser recording machine, the substrate is heated to 100° C. for 1 hour in ammonia gas and then allowed to cool.

Step (3) Once the substrate 31 has reached room temperature, the entire surface is irradiated with 300 to 20,001 J of ultraviolet light using an ultra-high pressure mercury lamp, and then heated to 0°2N.
Develop for 30 seconds using an alkaline developer.

Step (4) Next, wet etching is performed with a 20 wtX Fe Cl 3 aqueous solution, and the recorded signal is convex and its height is 1100 mm.
~ Obtained master recordings from 1,300 people.

Step (5) Using a 02 plasma asher, the photoresist remaining on the master is removed to obtain a stamper 35.

Step (6) After attaching this stamper 35 to a predetermined mold and molding a compact disc substrate with polycarbonate resin,
A compact disc (CD) is formed by forming an aluminum reflective film, a protective film, etc.

When the signal characteristics of the CD molded in this manner were investigated, it was found that the CD had better characteristics than a disk obtained from a conventional stamper manufacturing method.

(Example 2) Step (1) For example, on a flat glass plate with a diameter of 135 mm and a thickness of 1.51 mm, a bottom film of 1000 to 1300 μm of chromium is applied by sputtering, and on top of that, 1000 μm to 100 μm of the MP1400 is applied.
The coating was applied to a thickness of 500 mm, and the subsequent treatment was carried out in the same manner as in Example 1.

Process (2 to 3) Same as actual jfA example 1.

In this second embodiment as well, almost the same signal characteristics as in the first embodiment could be obtained.

(Example 3) Steps (1) to (2) For example, MP1400 is applied onto a flat Cu board with a diameter of 135 mm and a scratch of 800 to 1000 μm, and a film thickness of 1000 to 100 μm is applied.
Apply 0-order Ar to 500 ml and dry thoroughly.
After recording a desired recording signal using a laser recorder, it is heated in ammonia gas at 100° C. for one hour.

Step (3) After cooling, apply ultraviolet rays of 300 to 200 using ultra-high pressure mercury, etc.
Irradiate the entire surface with 0IIJ and use a 0.2N alkaline developer.
Developed for 30 seconds.

Step (4) Next, using the remaining resist as a mask, reactive ion plasma etching is performed to obtain a master disk with convex recording signals.

Step (5) and Step (6) As in Example 1, by the plasma ashing method of 02, etc.
By removing the photoresist residue, a stamper 35 similar to a conventional stamper is obtained. By molding this master disc as a stamper, it is possible to form excellent signal-made discs similar to those of the first and second embodiments.

(Example 4) (Step 1) Apply the above MP1400 to a thickness of 1000 to 1500 on a flat glass plate with a diameter of 135 mm and a thickness of 1 to 211 mm,
dry.

(Step 2) and (Step 3) Processing is performed in the same manner as in Example 1 to obtain a master disk having a recording exposure area made of a convex photoresist.

(Step 4) The above master disc was placed in CF4 gas (flow 15-308 CCH) with a vacuum degree of 10-50 II TOr and a power of 100-300 W.
Then, dry etching is performed for 40 to 80 minutes (Step 5) Next, as in Example 1, the photoresist residue is removed using the 02 plasma ashing method, and the conventional stamper is removed.
A stamper 35 similar to 23 is obtained.

(Step 6) In the same manner as in Example 1, a desired disk having concave recording signals is formed.

Note that in Examples 1 to 4, ammonia was used, but any substance that generates ammonia in a heated state may be used, and it goes without saying that an amine may be used.

(Effects of the Invention) As described above, according to the present invention, there are a step of exposing a substrate coated with a positive photoresist, a step of heating the substrate in an atmosphere containing ammonia or amine, and a step of exposing a substrate coated with a positive photoresist to a predetermined ultraviolet ray. irradiation and development to produce a master disk with recording signals made of convex photoresist, and dry or
The method is characterized in that it consists of a step of etching using a wet etching method to produce a stamper having a convex recording signal, and a step of forming a disk made of a desired material from the stamper, so that the number of times of electroforming can be reduced. It is possible to provide a method for manufacturing an information recording medium that can reduce the amount of noise, prevent deterioration of signal characteristics, and is advantageous in terms of cost.

[Brief explanation of drawings]

FIGS. 1(a) to (d) are block diagrams showing the main parts of the method for manufacturing an information recording medium according to the present invention, and FIGS. 2(A) to (E) illustrate a conventional method for manufacturing an information recording medium. FIG. 31...Substrate, 12...Positive photoresist, 1
3... Laser light, 32... Recording exposure section, 33.34
... Master, 35 ... Stamper

Claims (1)

[Claims] A step of exposing a substrate coated with a positive photoresist, a step of heating the substrate in an atmosphere containing ammonia or amine, and a step of developing the substrate after irradiating it with a predetermined ultraviolet ray to form a convex shape. A step of producing a master disk having a recording signal made of a photoresist, and a step of etching the surface of the master disk on which the photoresist is formed using a dry or wet etching method to produce a stamper having a convex recording signal. A method for manufacturing an information recording medium, comprising the steps of: forming a disk made of a desired material from the stamper.