JPH03269846A - Method for manufacturing a stamper for optical disc duplication - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing a stamper for duplicating optical discs such as laser discs and compact discs.

[Prior Art] Conventionally, in the production of a stamper for optical disk duplication, a master or mother was subjected to a release film treatment, Ni-plated, and then peeled from the master or mother to obtain a mother or a son. However, in this method, impurities contained in the plating solution are discharged and precipitated, resulting in defects on the surface of the mother or sun. As a method to solve this problem, a method described in JP-A-60-197959 has been proposed in which after treating a master or mother with a release film, a contact transfer layer of Ni is formed on the release film-treated surface by vacuum evaporation or sputtering. has been done.

[Means for Solving the Problem] However, as shown in FIG. 3, the outermost surface of the master 7 after the release film treatment is an active Ni hydroxide layer;
When a contact transfer layer 9 is formed by sputtering on top of the contact transfer layer 9 and normal Ni plating is performed (bath temperature 50°C), the OH groups in the active Ni hydroxide layer gasify due to the high bath temperature, resulting in volumetric expansion. The contact transfer layer 9 is then subjected to pressure and holes 11 are generated. As a result, a large number of depressions 13 are formed on the surface of the mother 12 obtained by peeling from the master 7, resulting in a problem in that the quality of the stamper is significantly degraded.

Furthermore, because part or all of the outer circumference of the mother 12 naturally peels off due to plating stress, the plating solution infiltrates from the peeled part and causes bleeding on the information transfer surface of the mother 12.
In addition, there was a problem in that the quality of the stamper was significantly degraded, such as the tip of the bit being crushed by the pressure applied by the backing, resulting in poor shape transferability.

And these things also apply to obtaining Sun from the Mother.

The present invention aims to solve the above-mentioned problems, and its purpose is to prevent natural peeling due to plating stress and to manufacture a high-quality stamper with no dents on the surface.

[Means for Solving the Problems] The present invention provides a method for removing a master or mother with a peeling film in a plating process when replicating a mother from a master or a plating process when replicating a sun from a mother in the manufacturing process of a stamper for optical disc duplication. After treatment, N is added to the release coating treated surface.
The present invention relates to a method for manufacturing a stamper for optical disk duplication, which comprises forming an i-stapper film, then plating by changing the temperature of a plating bath, and peeling it off from the master or mother to obtain a mother or a son.

Next, the present invention will be explained in detail based on FIGS. 1(a) to 1(f).

First, a conductive film is applied to a glass substrate on which fine irregularities have been formed by lithography, and Ni plating is applied to obtain a Ni master 1 (see FIG. 1(a)). Next, as shown in FIG. As shown in b), a peeling film 2 of a Ni oxide film is formed on the information transfer surface of this Ni master 1. This peeling film 2 is intended to make it easier to peel off the mother to be replicated later from the master 1. At this time, the Ni master 1
The outermost surface of the release film 2 becomes an active Ni hydroxide layer.Next, as shown in FIG. 1(c), a Ni sputtered film 3 is formed on the release film 2 by sputtering. This is to prevent impurities contained in the plating solution from discharging and precipitating on the release film 2 during the next plating process, thereby preventing the formation of dents on the surface of the mother that will be obtained later.
Next, as shown in FIG. 1(d), the temperature of the plating bath is lowered to perform Ni plating to form an initial plating film 4. When plating at the normal plating bath temperature (50°C), the OH groups in the Ni hydroxide layer on the resurface of the release film 2 gasify and expand in volume, creating holes in the Ni sputtered film 3. This plating prevents the formation of pores and prevents the mother surface from becoming dented afterwards. Furthermore, since the plating speed is slow, the Ni sputtered film 3 is plated with good adhesion, and natural peeling due to plating stress can be prevented. The temperature of the plating bath is preferably around room temperature (20° C.); if it is below room temperature, the plating speed is slow and plating takes too much time, which is economically problematic.

Further, the thickness of the initial plating film 4 at low temperature is 5 to 1
00 μm is preferable. If the film thickness is less than 5 μm, it is insufficient to prevent the occurrence of depressions due to the volume expansion of the O) group of the Ni hydroxide layer in the active state, and the Ni sputtered film 3
Since the plating film is too thin to be plated with good adhesion, peeling occurs between the initial plating film 4 and the subsequent plating film 5. Film thickness is 100μ
If it exceeds (2), plating takes a long time and is economically problematic.

Note that during plating at a low temperature, the OH groups of the activated Ni hydroxide layer on the outermost surface of the release film 2 are inactivated.

Next, as shown in FIG. 1(e), plating is performed by raising the temperature of the plating bath to form a plating film 5. The temperature of the plating bath at this time may be a normal temperature, and since the activated Ni hydroxide layer on the outermost surface of the release film 2 has been inactivated, no pores will be generated even if the plating temperature is increased. It doesn't happen.

After two stages of plating in this way, Fig. 1(f)
A Ni mother 6 is obtained by peeling from the Ni master 1 as shown in FIG. In the same way, Ni mother to Ni
You can get sun.

In the plating process of the present invention, there are no dents on the surface of the Ni mother, and the adhesion of the plating film is good, so natural peeling of the outer periphery of the Ni mother due to plating stress does not occur, resulting in a high quality stamper for optical disc duplication. enable manufacturing.

[Example J Next, the present invention will be explained with reference to Examples and Comparative Examples.

Example 1 After forming a conductive film on a pre-group pattern formed on a glass substrate, Ni plating was performed using the conductive film as a cathode, and a master was obtained by backing.

After treating the master with a peeling film, the temperature of the zero-order plating bath in which a Ni sputtered film was formed by sputtering was set to room temperature (20°C).
After forming a NL plating film with a thickness of 5 μm, plating was performed at a plating bath temperature of 50° C. After plating was completed, the mother was obtained by peeling it off from the master. Furthermore, from this mother I obtained Sun in the same way.

Example 2 A master was obtained in the same manner as in Example 1, and after treatment with a release film,
After forming the Ni sputtered film, plating was carried out with the plating bath at room temperature. After forming a Ni plating film with a thickness of 50 μm, plating was carried out at the plating bath temperature at 50° C. After plating was completed, the mother was obtained by peeling it off from the master. Furthermore, from this mother I obtained Sun in the same way.

Comparative Example A master was obtained in the same manner as in Example 1, and after treatment with a release film,
A Ni sputtered film was formed. Next, increase the temperature of the plating bath to 5
Plating was carried out at 0°C. After plating was completed, the mother was obtained by peeling it off from the master. Furthermore, from this mother I obtained Sun in the same way.

However, the composition of the plating bath is Ni450 sulfamate.
g/n, boric acid 30 g/I2. Surfactant 0.1g/
The I2° specific gravity was 28Be', and the current density was 8 A/d+o''.

FIG. 2 shows the defect rates of the master, mother, and sun obtained in Example 1.2 and Comparative Example, respectively.

From Figure 2, the defect rates of the master, mother, and sun obtained in Example 1.2 were low, and no increase in the defect rate was observed due to replication, but the master, mother, and sun obtained in Comparative Example had low defect rates. The defect rate clearly increased with replication.

[Effects of the Invention] As is clear from the above description, according to the plating method of the present invention, it is possible to produce a high-quality stamper for duplicating optical discs that is free from natural peeling due to plating stress and has no dents on its surface.

[Brief explanation of drawings]

Figures 1 (a) to (f) are cross-sectional views showing the steps of the manufacturing method of the present invention, and Figure 2 shows the defect rates of master, mother, and sun obtained in Examples 1 and 2 and Comparative Example, respectively. The graphs and FIGS. 3(a) to 3(e) are cross-sectional views showing the steps of a conventional manufacturing method. 1...Ni master 2...Peeling film, 3...
Ni sputtered film, 4... Initial plating film, 5... Plating film, 6... Ni mother 7... Ni master 8... Peeling film, 9... Contact transfer layer, lO.
...Plating layer, 11...hole, 12...Ni mother 13...dent Figure 1

Claims (1)

[Claims] In the plating process when duplicating the mother from the master in the stamper manufacturing process for optical disk duplication, or the plating process when duplicating the sun from the mother, after the master or mother is treated with a release film, a Ni stopper film is applied to the surface treated with the release film. 1. A method for producing a stamper for duplicating an optical disk, which comprises forming a stamper, then plating by changing the temperature of a plating bath, and peeling from the master or mother to obtain a mother or a sun.