JPS6045957A - Production of master for producing information storing medium - Google Patents

Abstract

PURPOSE:To form precisely the size and height of an information signal pit and an information signal reproducing group by intervening a photoresist separating layer between at least two kinds of photoresist layers applied to the surface of a substrate, and irradiating prescribed laser light. CONSTITUTION:The 1st photoresist layer 12 having low sensitivity to laser light, the photoresist separating layer 13 such as SiO2 and the 2nd photoresist layer 14 having high sensitivity to the laser light are laminated on the glass substrate 11 to form a master material 15. A laser beam 16 having a prescribed diameter and a fixed low intensity and a laser beam 17 having high intensity and modulated by an information signal are simultaneously irradiated to the master material 15 to develope the layer 14 and form the information signal reproducing group 18. The layer 14 is masked, the layer 13 is etched, then the layer 12 is developed to form the information signal pit 19. Consequently, the information signal reproducing group 18 and the information signal pit 19 are formed in the precise size and height.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a master disc for manufacturing information storage media, which is used for manufacturing information storage media such as optical discs.

[Technical background of the invention and its problems]

For example, as shown in FIG. 1, an information storage medium manufacturing master disk used for manufacturing information storage media such as optical disks has conventionally had a substrate 1 with a first and a second laser beam sensitive to one beam. A first laser beam (laser beam) 6 whose intensity is constant and a second laser beam (laser beam) whose intensity varies based on an information signal are applied to a master disk 4 on which a photoresist layer 2.3 is laminated. The information signal bit 7 and the information signal reproducing group 8 are formed by simultaneously irradiating with light 6 and then developing the information signal bit 7 and the information signal reproduction group 8, as shown in FIG.

However, with this method, the first. ! =262 photoresist N2 e 3 takes advantage of the difference in sensitivity of the first and second laser beams 5.

It is difficult to select the strength of 1 to 60, and since the first and second photoresist layers 2 and 3 are used in close contact with each other, the first and second photoresist layers 2 and 3 are As a result, the information signal pits 7 and the information signal reproducing groups 8 cannot be formed accurately to a predetermined size and height, as shown in FIG. 3.

[Purpose of the invention]

The present invention has been made based on the above circumstances, and an object thereof is to be able to accurately form information signal bits and information signal groups to predetermined sizes and heights, and to No. 2, it is an object of the present invention to provide a method for manufacturing a master disc for manufacturing an information storage medium, in which the intensity of 17-4N light can be easily controlled.

[Summary of the invention]

In order to achieve the above object, the present invention provides 17-
A first layer having a constant strength is added to the master material, which is formed by stacking a plurality of types of photoresist layers having different sensitivities to laser light, and interposing a photoresist separation layer between at least two of these photoresist layers. This method is characterized in that information signal pits and information signal reproducing groups are formed by irradiating a laser beam and a second 17-laser beam whose intensity LW changes based on the information signal.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS.
- Photo 1 dust layer 1 of fX J with low sensitivity to light
2, for example, 8102, 1-1-1. /Dust stamp layer 131 and IJf ji highly sensitive to laser light
', 2 photoresist layer 14 of this II! It l
All 15 master materials are formed by laminating them with a /7 varnish vinyl coat.

Next, this master disc 17s l? -110 diameter is 1 piece and O is 0.8 to 1.5 fitn and has low strength 2'('I
,'1017--Rei'-beam(Lei'-light) 16
The second one, which has a diameter of 0.3 to 0.511 m and a high strength
Laser beats (laser light) 17 are simultaneously irradiated on the same optical axis. At this time, the first laser beam 16k
J: -” Mv 11 degrees, second 17-za beam 1
7 changes the intensity based on 4t' stone + ai 7 ze/・, f- and auto: t 4 + town f + 4 (corresponding to No. 71, make it on mettsu.

Next, the second photoresist layer 14 is subjected to a development process. As a result, as shown in FIG. 5, the portion of the second photoresist layer 14 irradiated with the first laser beam 16 is cut out to form a group 18 for generating an information signal.

Next, the second photoresist layer 14 is masked and the photoresist separation R413 is etched using NI (4F (ammonium fluoride)) or the like.

Next, the first photoresist layer 12 is subjected to a development process. As a result, information signal bits 19 are formed. That is, since the low-intensity first laser beam 16 is absorbed by the photoresist separation layer J3 and the first photoresist layer 12 has a low intensity, as shown in FIG.
Second laser beam 1 on first photoresist layer 12
Only the irradiated portion 7 is cut out to form the information signal dot 19.Thus, the master disk 2o for manufacturing the information storage medium is formed.

According to the above manufacturing method, the master material 7.517. ffl; In order to form information signal bits 19 and information signal reproduction groups 18 by irradiating the J and second 17 laser beams 16.17, the first and J
No intermixing of photoresist layer 12.14 of p, 2;
Since there are no gaps, the information signal pit 19 and the 1st P signal reproduction group 18 can be formed accurately to a predetermined size and height.
The intensities of the first and second laser beams 16+17 are easy to control 1111.

〔Effect of the invention〕

As explained above, in the VCX-X of the present invention, photoresist layers of multiple types having high sensitivity to laser light are laminated on the matrix soil, and at least two types of photoresist layers among these layers are laminated. irradiating the master material 1 to 1 with a photo 1/dust separation layer interposed therebetween with a first 1/-re'-light whose intensity is constant and a second laser beam whose intensity changes based on an information signal; The bits for information signals and the groups for reproducing information signals are formed by IF to a predetermined size and height.
, it can be formed reliably and the intensity of the first and +2 laser beams can be easily controlled, resulting in an excellent effect.

[Brief explanation of drawings]

Figures 1 to 3 show conventional examples; Figure 1 is a cross-sectional view showing the master disc material being irradiated with the first and second laser beams; Figure 2 is a perspective view of the master disc; Fig. 3 is a cross-sectional view of the master disc, and Figs. 4 to 6 show an embodiment of the present invention, and Fig. 4 shows a state in which the master disc is irradiated with the first and second laser beams. FIG. 5 is a cross-sectional view showing the developed state of the second photoresist layer, and FIG. 6 is a cross-sectional view M showing the developed state of the first photoresist layer. 1)...Substrate, 12...First photoresist layer,
1.7... Photoresist separation layer, 14... Second photorenost layer, 15... Master material, 16... First laser beam (laser uC), 17... 11
1/- laser beam of λ2, 18...1
Blue shoulder (signal reproduction group, 19...4) 1, 13
Signal IR Bi, 71°20... Information storage medium! II! !
Lid board for production, Applicant's representative Patent attorney Takeshi Suzue Figure 1 Figure 3

Claims (1)

[Claims] Multiple types of photoresist layers with different sensitivities to laser light are laminated on a substrate, and a photoresist separation layer is interposed between at least two of these photoresist layers to create a master material with a constant strength. An information storage medium characterized in that an information signal bit and an information signal reproduction group are formed by irradiating a first laser beam and a second laser beam whose intensity changes based on the information signal. A method of manufacturing master discs for production.