JPH02277791A - Production of stamper for optical disk - Google Patents

Abstract

PURPOSE:To produce many stampers having excellent releasability and high transfer precision at a time by fixing a mother stamper to a plasma ashing device, irradiating the stamper with plasma, then forming an Ni oxide film and using the film as a dry releasable film. CONSTITUTION:A resist film 2 is formed on a glass substrate 1, information is recorded, and the film is developed to form a prepit 3. Ni is sputtered to form a conductive film 4, and an Ni plating layer 5 is formed with the film 4 as a cathode. The layer 5 is released from the substrate 1, and the resist film 2 is removed to obtain a mother stamper 5'. The mother stamper 5' is fixed to the plasma ashing device, and continuously treated with plasma 6 to form a releasable film 7. The mother stamper 5' is plated with Ni with the aid of the film 7 to obtain an Ni plating layer 8. The layer 8 is released to form a child stamper 8'. The child stamper 8' is treated in the same way as the mother stamper 5' to obtain a master stamper.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method of manufacturing a stamper for optical discs.

[Conventional technology]

As is well known, the conventional method for manufacturing a stamper for optical disks is to apply a resist to a clean glass substrate, record with a laser beam, and after the phenomenon occurs, Ni is sputtered onto the resist-coated substrate, and then a Ni sputtered film is formed. Ni plating is performed as a cathode, and after polishing the back surface, the glass substrate is peeled off. Furthermore, the resist film is washed and removed to form a mother stamper. Next, a wet release treatment film is applied to the information recording side.

Subsequently, Ni plating is performed using the mother stamper as a cathode to transfer and form a child stamper. After that, the child stamper is peeled off from the mother stamper. Furthermore, the child stamper is subjected to wet mold release treatment. Next, Ni plating is performed using the child stamper as a cathode to transfer and form a master stamper. Thereafter, the master stamper is peeled off from the child stamper, and after a predetermined processing is performed, it is used as a mold for injection molding.

[Problem to be solved by the invention]

In the conventional manufacturing method of stampers for optical discs, when the child stamper is peeled off from the mother stamper and the master stamper is peeled off from the child stamper, the mold release process that occurs due to the instability of the wet mold release process on the mother and child stampers is required. The child stamper and master stamper tend to have poor releasability due to variations in the thickness and strength of the film.

In addition, there is the problem that the transfer rate of the mother and child stampers is poor due to poor mold release performance due to variations in the adhesion between the mother and child stampers and the child and master stampers via the mold release treatment film. The durability of the child stamper is also low, making it undesirable for practical use.

In addition, as the transfer progresses from mother to child and from child to master, the error rate tends to increase sharply, and the limit point for continuous transfer is short, making it unsuitable for mass production, and furthermore, making it impossible to reduce costs. It also has the following problems.

The present invention solves the above-mentioned problems, and its purpose is to improve the stability of the mold release treatment film and improve the mold release performance of the stamper, thereby achieving high quality with high transfer accuracy at low cost. Our goal is to supply a large number of master stampers.

[Means to solve the problem]

The method for manufacturing a stamper for optical discs of the present invention includes coating a photoresist on a glass substrate kept clean, forming a pregroove pattern using etching technology, forming a conductive film thereon, and then forming a conductive film on the pregroove pattern. In the process of performing Ni plating using the mother stamper as a cathode to form a mother stamper, performing a mold release treatment on the mother stamper, performing Ni plating, and forming a master stamper using a transfer technique, the mother stamper is placed in a plasma ashing device. A nickel oxide film is formed on the mother stamper by attaching the mother stamper to the mother stamper and irradiating the mother stamper with plasma to purify and oxidize the surface, and the oxide film is used as a dry release treatment film.

Further, the nickel oxide film according to the second aspect of the present invention is characterized in that the thickness as a mold release treatment film is between 5 Å or more and 10A or less.

〔Example〕

FIG. 1 shows the configuration of an optical disc stamper according to the present invention.

Here, 101 is a stamper, and 102 is a tip of a convex portion of the stamper, which becomes an information recording portion after being transferred to a medium.

[Example-1] As shown in Figs. 2 to 13, the thickness of 6
A resist film 2 of 1100A was formed on a glass substrate 1 of II11 by a spin code method using an Az photoresist. Further, lift baking was performed at 80° C. for 30 minutes in a drying oven. Next, after information was recorded using a laser cutting machine, pre-pits 3 were formed using an Az developer at a temperature of 22° C. for 60 seconds, and after thorough water washing, spin drying was performed. Further, post-baking was performed at 90° C. for 30 minutes using a drying oven. Next, it was installed in a sputtering device and Ni was sputtered to a thickness of 70.0 mm to form a conductive film 4.

Next, Ni plating was performed using the sputtered film as a cathode to form a plating layer 5 having a thickness of about 300 μm. Furthermore, it is peeled off from the glass substrate 1, thoroughly cleaned, and the resist film 2 is removed from the glass substrate 1.
was removed to form a mother stamper 5'. Next, the mother stamper 5' was attached to a plasma ashing device, and subjected to plasma 6 treatment for 3 minutes continuously to form a release-treated film 7. Using this counterfeit treated film, the mother stamper was plated with Ni to obtain a plating layer 8 of about 300 μm. Next, the obtained Ni
The plating layer was peeled off from the mother stamper to obtain a child stamper 8'. Furthermore, the child stamper 8' was subjected to the same treatments and steps as the mother stamper to obtain a master stamper 9'. As a post-process, the plating surface was polished, the inner and outer diameters were processed, and a stamper was supplied as a mold for media molding. Further, it was possible to repeatedly take out six child stamps from this first mother stamper, and four stamps from each child stamper.

Furthermore, the transfer accuracy was at a level sufficient to withstand use.

[Example 2] Example 2 with different plasma ashing conditions will be shown.

During plasma ashing, the treatment time was increased intermittently to make the treated film stronger. The processing conditions were as follows: 5 minutes of ashing, then 10 minutes of standing, and 5 more minutes of ashing, resulting in a total of 10 minutes of plasma ashing, and a master stamper was obtained in the same process as in Example-1.

〔Effect of the invention〕

As described above, the method for manufacturing an optical disk stamper of the present invention has excellent mold release performance, high transfer accuracy, good durability, and superior performance to the conventional wet mold release treatment film method. A stamper can be obtained at a low cost based on the number of sheets.

[Brief explanation of drawings]

FIG. 1 is a main sectional view of an optical disc stamper according to the present invention. FIGS. 2 to 13 are cross-sectional views showing the manufacturing process of the optical disc stamper according to the present invention. 101 11 conflicts 102- ・ ・ ・ 1 conflict ・ 11 φ 2 ・ ・ ・ ・ 3φ e prefecture − 4... life fist 5 φ ・ misery ・ 6φ ・ ・ ・ 7 ・ ・ meeting ・ 8 ・ ・ ・ 8′ - Stamper stamper convex portion Glass substrate Resist film Pre-pit Ni conductive film Plating layer Plasma release treatment film Plating layer Child stamper 9...Dispute...Plating layer 9' Master stamper and above Applicant Seiko Epson Corporation Agent Person Patent Attorney Kisanbe Suzuki (and 1 other person) Figure 3, Figure 40, Figure 5, Figure 116, Figure 7, Figure 8, Figure 9, Figure 10, Figure 112, Figure 12, Figure 13.

Claims (2)

[Claims] (1) After applying photoresist to a glass substrate kept clean and forming a pregroove pattern using etching technology,
A conductive film is formed on this, and then Ni plating is performed using the conductive film as a cathode to form a mother stamper.Furthermore, the mother stamper is subjected to mold release treatment, and then Ni plating is performed, and transfer technology is applied. In the step of forming a master stamper, the mother stamper is attached to a plasma ashing device, and a nickel oxide film is formed on the mother stamper by irradiating plasma to purify and oxidize the surface. A method for manufacturing an optical disc stamper, which comprises mold processing. (2) The method for manufacturing an optical disk stamper according to claim 1, wherein the thickness of the release treatment film as a nickel oxide film is from 5 Å to 110 Å.