JPS593731A - Manufacture of information disk - 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 Technical Field of the Invention The present invention relates to a method for manufacturing an information master used for manufacturing substrates for optical discs, video discs, etc., and particularly for manufacturing substrates on which information is recorded in the form of irregularities.

Conventional Technology and Problems Conventionally, when manufacturing this type of information master, a photoresist is coated on a glass substrate, and while it is rotated, a focused light beam that is intensity-modulated is irradiated onto the photoresist (two pieces of information). Then, an original image was formed using an original image solution to form irregularities in the photoresist to obtain an information master.

However, this method had various drawbacks as follows.

(1) The resist must be coated onto the substrate at a uniform thickness (approximately 1A or 1/4 of the wavelength of normal light), and the so-called spin code method has no choice but to obtain a uniform thickness. Have difficulty.

(2) Photoresist is weak in strength and easily damaged.

(3) Since the light reflectance of photoresist is extremely low at around 4%, the reflected light for so-called focus servo, which accurately focuses the condensed beam on the resist surface, is weak, making it impossible to stably maintain focus servo. .

Purpose of the Invention The present invention is intended to solve the above-mentioned various drawbacks.It is an object of the present invention to provide information that can stably align the heights of uneven information, is easy to operate to record information, and has excellent mechanical strength. The purpose is to provide a method for manufacturing master discs.

Examples of the invention The invention will now be described in detail in conjunction with the drawings.

According to the present invention, the information master is formed by forming a concavo-convex information forming layer made of silicon oxide on a glass substrate, on which (two auxiliary layers made of an easily etched organic material and a metal layer are successively formed). After that, a predetermined portion of the metal layer is perforated and removed by irradiating the metal layer with information (secondary intensity-modulated focused light), and then the auxiliary layer is etched using the removed portion of the metal layer as a window. Next, using the removed portion of the auxiliary layer as a window, only the uneven information forming layer is etched without substantially etching the auxiliary layer to form information consisting of unevenness on the uneven information forming layer, and finally (= Manufactured by removing the auxiliary layer and metal layer.

The information master disk having unevenness information manufactured in this way is made into an optical disk by a known method such as an electroforming method or a molding method.
It can be used to manufacture substrates for video discs, etc. For example, a Ni layer with a thickness of about 3 mm is formed on the information forming surface of the information master obtained by the above-mentioned process, and this Ni layer is taken out from the information master and placed on the base (: adhesive). This stamper is then used to perform pressing or injection to manufacture substrates for optical discs, video discs, etc.

Next, a specific example of the above-mentioned process will be described.

First, as shown in Figure 1 (α), the outer diameter is 356m77L.
Silicon dioxide (Sin) is vacuum-deposited on the surface of a disc-shaped glass substrate 1 having an inner diameter of 20WL1n and a thickness of 6rrLrrL by electron beam heating to form uneven information forming Ni2. The film thickness is set to a constant value of 400 to 1400A.

Since this film is formed by vacuum evaporation method C2, the uniformity of the film thickness can be maintained with high precision. Next, add Figure 1 (
h) l-As shown (-, photoresist (AZ135
0J) to form an organic auxiliary layer 6, and then tellurium (T-) is vacuum deposited to form a metal layer 4.

The thickness of the auxiliary layer 3 is 0.5 to 2 of the thickness of the uneven information forming layer 2.
The thickness of the metal layer 4 is about 100A.

Next, while rotating this around the central axis of the disk of the gas substrate 1, an argon laser beam of 0.8μ is applied to the metal layer 4.
Door φ (irradiated with square light and removed the metal layer of the irradiated part,
A window 5 is formed as shown in Figure (C) (2).

In this case, the light intensity of the laser beam is intensity-modulated according to the information to be recorded, and the laser beam has a substrate rotation speed of 180 Or
pm, the T-film in the irradiated area can be melted and removed if the power is about 8 mW or more at a position of 300 mm in diameter. Further, since the reflectance of the T-plane is 30%, the position of the objective lens can be easily corrected using the reflected light, so-called focus servo. The dimensions of the window 5 thus formed (the diameter 9 width of the hole or groove, etc.) are determined by the power of the irradiated laser beam.

Next, this is placed in a parallel plate electrode type plasma etching apparatus, and the auxiliary layer 3 and the uneven information forming layer 2 are etched through the window 5, and the holes 6 and 7 are etched as shown in FIG. 1(d).
form. In this case, first the vacuum level is 5Q mTorr.
02 gas is introduced and the auxiliary layer 6 under the window 5 is removed to form the hole 6.
Next (two consecutive CFs with a vacuum degree of 100 mTorr)
4 gas is introduced and the uneven information forming layer 2 under the hole 6 is etched until the glass substrate 1 is exposed, thereby forming the hole 7. Incidentally, when etching the second unevenness information forming layer, etching may not be performed until the glass substrate is exposed, but etching may be performed until the depth of the hole or groove dug in the SzO2 becomes appropriate. In the former case (when etching is performed until the glass substrate is visible), the initial thickness (=Sin of the formed unevenness information forming layer 2) determines the final depth of the hole 7.Finally, as shown in FIG. ), the remaining auxiliary layer 3 and metal layer 4 are removed by 02 plasma to complete the information master 10. This information master 10 has 5 iot of unevenness information on the glass substrate 1. be.

In the above-mentioned process, when forming the auxiliary layer 3, AZ135 (
In addition to organic materials such as No. 17 that are applied in the form of a solution, it is also possible to use materials that can be deposited using a vapor deposition method, such as copper phthalocyanine. FIG. 2 shows the procedure for forming each layer using this material. In the figure, 3' is an auxiliary layer of copper phthalocyanine;
Reference numeral 8 denotes a stabilizing layer made of an amorphous carbon film formed thereon, each having an auxiliary film thickness. The stabilizing layer 8 is formed to prevent the surface of the copper phthalocyanine from being disturbed when forming a window by irradiating the Ty metal layer 4 with focused light. In this case as well, the same steps as those explained in FIG. 1 are followed to form a hole in the metal layer 4 by irradiating focused light and O! Etching of the stabilizing layer 8 and the auxiliary layer 5' by plasma, etching of the uneven information forming layer 2 by CF, plasma, and the remaining metal makes it possible to obtain an information master.

Organic materials other than copper phthalocyanine that can be used with the vapor deposition method include other metal phthalocyanines, styrene, acrylic (PMMA), and the like.

In the above explanation, an example was described in which a metal film was formed using Tg.
, As, etc., or Al, AlL.

Single substances or alloys of Cr, Ti, Sn, Ph, etc. can be used.

Effects of the Invention As described above, according to the present invention, it is possible to easily manufacture an information master with good reproducibility on its surface having unevenness information with good uniformity and excellent strength.

[Brief explanation of drawings]

The drawings show an example of the method for manufacturing an information master according to the present invention, and FIG. 1 (α) to (-) are manufacturing process diagrams showing the order of the steps, and FIG. FIG. 3 is a diagram showing how to form each layer when used. In the figure, 1 is a glass substrate, 2 is an uneven information forming layer, 3.3'
is an organic auxiliary layer, 4 is a metal layer, 5 is a window, 6.7 is a hole,
8 is a stabilization layer, and 10 is an information master. Patent applicant Fujitsu Ltd. agent Patent attorney Gobe Tamamushi (3 others) Figure 1 Figure 2

Claims (1)

[Scope of Claims] (1) After forming an uneven information forming layer made of silicon oxide on a glass substrate, and sequentially forming an auxiliary layer made of an organic material and a metal layer thereon, information is formed on the metal layer. A predetermined portion of the metal layer is perforated and removed by irradiating focused light whose intensity is modulated by the etching method, and then the auxiliary layer is etched using the portion where the metal layer is removed as a window.Next 1: The portion where the auxiliary layer is removed is used as a window ℃, only the uneven information forming layer is etched without substantially etching the auxiliary layer to form the uneven information forming layer (
= A method for manufacturing an information master, characterized by forming information consisting of unevenness, and finally removing the auxiliary layer and the metal layer. (2) The manufacturing method according to claim 1, wherein a stabilizing layer is interposed between the auxiliary layer of organic material and the metal layer. (6) The manufacturing method according to claim 2, wherein the stabilizing layer is a carbon thin film.