JPH0273987A - Method for duplicating stamper - Google Patents

Abstract

PURPOSE:To easily duplicate a high-quality stamper at a low cost by forming a metallic Cr thin layer on a photoresist coated glass master, removing the photoresist, then forming a conductibilizing film and a releasing film, and applying Ni electroplating. CONSTITUTION:A pitted and grooved photoresist 2 is provided on the surface of a glass master disk 1 to obtain a glass master. A metallic Cr thin layer 3 is then formed on the whole surface of the glass master by vapor deposition, etc. The glass master disk 1 is dipped in a photoresist release soln. to remove the photoresist 2 along with the metallic Cr thin layer thereon, and a pitted and grooved metallic Cr thin layer 3 is left on the glass master disk 1. The conductibilizing film 4 of Ni, etc., is formed thereon in about 500-1000Angstrom thickness by vapor deposition, etc., and a releasing film is further formed. Ni electroplating is applied on the upper layer in specified thickness. The formed Ni electroplating layer 5 is released from the interface with the releasing film, and a high-quality duplicated stamper is obtained.

Description

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

[Conventional technology]

In the conventional method for replicating an optical memory stamper, a glass master is first manufactured.

A mirror-polished glass master l having an outer diameter of 200 mm, an inner diameter of 10 mm, and a thickness of 6 mm is prepared.

HM before coating the glass master 1 with photoresist.
The glass master disk 1 is exposed to the vapor of DS (hexamethylene disilazane), and the surface of the glass master disk 1 is subjected to Si coupling treatment. The purpose of this Si coupling treatment is to improve the adhesion between the photoresist film 2 and the glass surface in the next step. Next, photoresist is coated to a predetermined thickness using a spin method.

The photoresist used was AZI350 positive resist manufactured by Hoechst.

Next, a dedicated laser cutting M/C is used to irradiate and expose the pit and groove portions of the treatment position and shape with laser light.

Next, by chemically dissolving the exposed area using a specified phenomenon liquid, a glass master with pits and grooves formed in the photoresist 2 is created on the glass substrate 1. A conductive treated Ni film 4 is formed. The conductive Ni film is generally formed by vapor deposition or sputtering.

Appropriate thickness is about 1.0OOA.

Next, Ni plating is performed to give a thickness of 300 μmm.
An electroformed layer 5 is formed.

Next, the Ni electroformed layer 5 is peeled off from the glass master 1, the resist layer adhering to the Ni electroformed layer 5 is chemically dissolved, washed and dried, and the Ni electroformed layer 5 has the pits and grooves formed on the glass master transferred thereto. An electroformed layer 5 is formed. This Ni electroformed layer 5 is generally called a father.

In addition, when the glass master used to make the above father is removed, the photoresist layer 2 does not completely remain on the glass master side when the glass master and the Ni electroformed layer 5 are peeled off, so the appearance before peeling off is not the same. It is not of a quality that can be used again.

Next, the father was immersed in a chromic acid aqueous solution to form a release film, and then Ni electroplated to a thickness of 30 mm.
A Ni electroformed layer 5 with a thickness of 0 μmm is formed.

Next, when the Ni electroformed layer 5 formed through the father and the release treatment film is peeled off, the Ni electroformed layer 5 to which the pits and grooves formed on the father have been transferred is completed. This Ni electroformed layer 5 is generally called a mother.

Next, the above mother was immersed in a chromic acid aqueous solution to form a release treatment film, and then Ni@P plating was performed to a thickness of 300 μm.
m of Ni electroformed layer 5 is formed.

Next, Ni was formed through the mother and the release treatment film.
When the electroformed layer 5 is peeled off, a Ni electroformed layer 5 to which the pits and grooves formed in the mother are transferred is completed. This N
The electroformed layer 5 is generally called a child and serves as a stamper used in actual molding.

As described above, the conventional stamper duplication method requires Ni electroforming plating at least three times to complete a duplicate stamper.

[Problem to be solved by the invention]

The conventional method of reproduction described above is to first make a father from a glass master, make a mother from a father,
Reproduction is done by performing Ni electroforming three times to create a child from a mother, which takes a lot of man-hours.

Furthermore, since the number of copies is large, it is easily affected by quality deterioration due to transfer.

An object of the present invention is to reduce the number of times of duplication and to provide a low-cost, high-quality duplication stamper.

[Means to solve the problem]

The reproduction of the stamper of the present invention is performed by processing a glass master with photoresist on which pits and grooves are formed to a thickness of C.
After forming the r metal thin layer 3, the photoresist is immersed in a H solution to remove the photoresist 2, thereby removing the Cr metal thin film layer 3 on the photoresist, and then forming a conductive treatment film 4 on top of it to the desired thickness. After the formation, N1 is electroplated to a predetermined thickness and peeled off from the interface between the release film on the conductive film and the Ni electroform layer 5.

〔Example〕

A mirror-polished glass master disk 1 having an outer diameter of 200 mm, an inner diameter of 10 mm, and a thickness of 6 mm is prepared. Before coating the glass master disk 1 with photoresist, the glass master disk 1 is exposed to HMDS (hexamethylene disilazane) vapor, and the surface of the glass master disk is subjected to Si coupling treatment.

The purpose of this Si coupling treatment is to improve the adhesion between the photoresist film 2 and the glass surface in the next step.

Next, photoresist 2 is coated to a predetermined thickness using a spin method.

Next, the pit and groove portions of the treatment position and shape are irradiated with laser light and exposed using a dedicated laser power cutting M/C.

As mentioned above, when the pit and groove portions of the processing position and shape are exposed by irradiating laser light using the laser power drawing M/C, the photoresist used is preferably a negative resist. This is because the exposed portion of the photoresist 2 must remain when it is developed later.

When a positive resist is used, mask exposure is performed using a crow mask with black pits and grooves.

Next, by using the starting developer to chemically dissolve the photoresist in areas other than the exposed areas, a glass master in which pits and grooves are formed in the photoresist 2 on the glass master is completed.

Next, a thin Cr metal layer 3 is applied to the entire surface of the glass master.
form.

The method for forming the Cr metal thin layer 3 is preferably a dry method such as a vapor deposition method or a sputtering method.

The thickness of the Cr metal thin layer 3 is made the same as the depth of the grooves and grooves to be formed.

Next, the glass master 1 on which the Cr metal thin layer 3 has been formed is immersed in a special photoresist stripping solution to remove the photoresist partially formed on the glass master.

By peeling off the photoresist 2, the thin Cr metal layer 3 on the photoresist is also removed, and pits and grooves are formed in the thin Cr metal layer on the glass master.

Next, a conductive treatment film 4 is formed to the thickness of the treatment.

The metal used as the conductive film is generally Ni.

The method for forming the conductive Ni film 4 is preferably a dry method such as a vapor deposition method or a sputtering method.

The thickness of the conductive Ni film 4 is preferably 500 to 1,000.

Next, a release treatment film is formed on the Ni conductorization treatment film.

The mold release treatment film can be formed by a commonly used method of immersion in an aqueous chromic acid solution.

The chromic acid compounds that can be used are chromic acid (Cr203),
These include sodium dichromate, potassium dichromate, ammonium dichromate, etc.

The temperature is 0. 1% or less, the immersion time is 60 seconds or less, and the liquid temperature is room temperature.

After the mold release treatment film is formed, it is thoroughly washed with water and Ni electroplating is performed. The thickness is 300 μm, which is the thickness that can be used with a stamper.
m rank is common. As the Ni electroforming plating bath, a Ni sulfamic acid bath is generally used.

Next, when the Ni electroformed layer 5 is peeled off from the interface of the release treatment film of the Ni conductorized film of the glass master, a Ni electroformed layer 5 is formed in which the pits and grooves of the glass master are completely transferred.

By processing the inner and outer diameters of this N1 electroformed layer 5 and polishing the release surface, the first duplicate stamper is completed.

The glass master peeled off from the first duplicate stamper is used to manufacture the second and subsequent duplicate stampers.

Since the mold release treatment film for the second and subsequent glass masters has already been formed, Ni electroforming plating is applied to the glass masters to a thickness of 300 μm.
A second replica stamper is obtained by forming an N1 electroformed layer 5 of m in thickness and peeling off this Ni electroformed layer 5 from the release-treated film interface of the Ni conductive-treated film of the glass master. The stamper is duplicated by repeating the same operation as above for the third and subsequent sheets.

The glass master is entirely covered with a thin Cr metal layer 3 except for the pits and grooves of the recording section, and the thin Cr metal layer is tightly adhered to the surface of the glass substrate.
The thin Cr metal layer does not peel off from the surface of the glass substrate.

In addition, the adhesion between the conductive Ni film and the Cr metal thin layer is as follows:
Ni conductorization treatment film 4”2 release treatment film and Ni electroforming layer 5
Since the adhesion is much superior to that of the Cr metal thin layer 3, the conductive Ni film will not peel off from the Cr metal thin layer 3. In order to perfect the adhesion between the Cr metal thin layer 3 and the conductive Ni film 4, for example, when sputtering Ni, it is recommended to first sputter Cr and then sputter Ni in the same batch. . A Cr thickness of 100 or less is sufficiently effective.

As described above, the Cr metal thin layer 3 and the Ni conductive treatment film 4 formed on the glass master are well-adhered to the glass master 1, so that the same glass master can be used more than 10 times.
Even if the second duplicate stamper is made, there will be no appearance defects such as peeling off of the Cr metal thin layer 3 and Ni conductor treatment WA4 from the glass master, and the appearance of the glass master will not be damaged by duplication. There isn't.

〔Effect of the invention〕

As described above, in the method for replicating a stamper of the present invention, a thin Cr metal layer 3 is formed to the desired thickness on a photoresist-attached glass master in which pits and grooves are formed, and then immersed in a photoresist stripping solution. By removing the photoresist 2, the Cr metal thin layer 3 on the photoresist is removed, a conductive treatment film 4 is formed on it to the desired thickness, and then a release treatment film is formed, and then Ni is deposited to the desired thickness. By peeling off from the interface between the electroformed release film on the conductorized film and the N1 electroformed layer 5, it is possible to make a duplicate stamper in one electroforming process, whereas the conventional method requires at least three times. A replica stamper can be produced at a lower cost than a replica stamper that requires an N1 electroforming plating process. Furthermore, in terms of quality, since the number of times of replication is small, a replica stamper produced by the method of the present invention has a higher quality than a replica stamper produced by the conventional method.

[Brief explanation of the drawing]

FIGS. 1(a) to (e) are process cross-sectional views showing the manufacturing process of the stamper duplication method of the present invention, and FIGS. 2(a) to (g)
) is a process sectional view showing the manufacturing process of a conventional stamper manufacturing method. Applicant: Seiko Epson Corporation

Claims (1)

[Claims] 1) After forming a thin Cr metal layer to a desired thickness on a glass master with photoresist in which pits and grooves are formed, the thin Cr metal layer on the photoresist is removed by immersing it in a photoresist stripping solution and removing the photoresist. , form a conductive treatment film on it to a desired thickness,
Next, after forming a release film, Ni is electroplated to a predetermined thickness and then peeled off from the interface between the release film and the Ni electroformed layer on the conductive film.