JPH0636363A - Optical disk deposition method and deposition apparatus - Google Patents

Abstract

(57) [Summary] [Purpose] To obtain an optical disc having high adhesion between an organic protective film and a recording film and having excellent reliability. [Structure] A mask 1 is arranged to provide a non-film forming area on the outer peripheral portion of a substrate 2, and a clearance [mm] between a thin film forming surface 3 of the substrate 2 and the mask 1 is represented by X. The clearance [mm] between the portion 4 and the mask 1 is Y
X and Y are expressed by the following formula: 0 ≦ X ≦ 0.5 0 <Y ≦ K (T2-T1) × R (wherein R represents the diameter [mm] of the substrate, and K Represents the linear expansion coefficient [/ ° C] of the substrate, T1 represents the substrate temperature [° C] before film formation, and T2 represents the substrate temperature [° C] during film formation). .

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk film forming method and film forming apparatus.

[0002]

2. Description of the Related Art In recent years, optical disks for irradiating a laser beam to record information and reproducing the recorded information have been widely used. Among them, the magneto-optical disk that utilizes the magneto-optical effect is not only rewritable but also capable of overwriting, and it is expected that the application will expand in the future, and the recording film material used for the magneto-optical disk is rare earth. Since it is an amorphous alloy composed of a metal and a transition metal, it is easily oxidized. In order to prevent oxidation, it is common to stack a protective film made of a dielectric material or a metal oxide having excellent corrosion resistance on both sides of the recording film.

[0003]

However, since the inner and outer peripheral end faces of the recording film are not covered with the dielectric film or the metal oxide film, the oxidation from the inner and outer peripheral end faces cannot be prevented. Therefore, at the time of film formation, a mask is provided to form a non-film formation area on the inner and outer peripheral end surfaces of the substrate to form a recording film, a protective film, etc., and then the inner and outer peripheral ends of the recording film, etc., and the recording film, etc. By forming an organic protective film on the entire surface of
There is a technique for preventing oxidation from the inner and outer peripheral end faces. However, the non-recording area (corresponding to the mask setting area) on the outer peripheral portion of the substrate is made as small as possible in order to expand the recordable area as the demand for miniaturization and high density of magneto-optical disk in the market increases. The need has arisen. Also,
The properties required for the above organic protective film are that they have excellent oxygen gas barrier properties and low moisture permeability, and that they have excellent adhesion to the recording film and substrate material. No organic protective film agent satisfying the characteristics has been found.

The present invention has been made in view of the above-mentioned problems of the prior art, and provides a film forming method capable of producing a highly reliable optical disk, which has high adhesion between an organic protective film and a recording film. An object is to provide a film forming apparatus.

[0005]

According to the present invention, the above object is to dispose a mask for providing a non-film forming area on the outer peripheral portion of a substrate and to provide a clearance between the thin film forming surface of the substrate and the mask. mm] is represented by X, and the clearance [mm] between the outer peripheral end face of the substrate and the mask is represented by Y, X and Y
And the following formula 0 ≦ X ≦ 0.5 0 <Y ≦ K (T2-T1) × R (wherein, R represents the diameter [mm] of the substrate, and K represents the linear expansion coefficient of the substrate [/ C.], T1 represents the substrate temperature [C] before film formation, and T2 represents the substrate temperature [C] during film formation). It is achieved by providing a method for forming an optical disc.

Further, according to the present invention, the above object is to provide a mask for providing a non-film forming area on the outer peripheral portion of the substrate, and to set a clearance [mm] between the thin film forming surface of the substrate and the mask to X. When the clearance [mm] between the outer peripheral end surface of the substrate and the mask is represented by Y, X and Y satisfy the above expression, thereby providing a film forming apparatus for an optical disc. To be achieved.

[0007]

The result of observing the outer peripheral end face of the recording film formed on the substrate in detail with an optical microscope is shown in FIG. As shown in FIG. 2, a non-film formation region (5), a slightly formed intermediate region (6), and a film formation region (7) are recognized from the outermost peripheral end face portion of the substrate. Here, it has been found that the adhesion between the organic protective film and the recording film is closely related to the width of the intermediate region (6). That is, the adhesion between the organic protective film and the recording film can be enhanced by reducing the size of the intermediate region existing at the boundary between the non-film formation region and the film formation region. If the above clearances X and Y are within the range of the above equation,
The above intermediate region can be reduced. When Y is 0, cracks may occur in the recording film due to strain in the substrate when the substrate is stretched due to a rise in the substrate temperature during film formation, and it is preferable that Y is 0. Absent.

[0008]

EXAMPLES The present invention will be specifically described below with reference to examples. (Embodiment 1) FIG. 1 is a layout view of an example of a mask and a substrate according to the present invention. In FIG. 1, the clearance between the thin film forming surface 3 of the substrate 2 and the mask 1 is represented by X, and the clearance between the outer peripheral end surface portion 4 of the substrate 2 and the mask is represented by Y.

In the in-line type magnetron sputtering apparatus, the above mask having X of 0.2 mm and Y of 0.2 mm is used, and the diameter (R) is 5.25 inches (about 130 m).
m), a dielectric protective film (SiN film: 100 nm), a magneto-optical recording film (TbFeCo amorphous alloy film: 25 nm), a dielectric protective film (SiN film: 35 nm) and a 1.2 mm thick polycarbonate substrate. Reflective film (A1
Film: 50 nm is laminated, and an organic protective film (UV curing resin SD-manufactured by Dainippon Ink and Chemicals, Inc.) is formed on these films.
17) was formed by spin coating so as to have a film thickness of 10 μm to prepare a magneto-optical disk. The temperature of the substrate before film formation was 23 ° C., the temperature of the substrate during film formation was 50 ° C.,
The linear expansion coefficient K of the polycarbonate substrate is 6.0 × 10 ^-5
(/ ° C).

As a method of evaluating the adhesiveness of the recording film to the outer peripheral edge of the substrate, a cutting knife is used to make a cut of 1 m.
Put 11 pieces vertically and horizontally at m intervals to make a total of 100 pieces of base mesh, stick cellophane tape on it, and then rapidly peel off and count the number of bases of the peeled organic protective film to obtain the organic protective film and recording film. Was evaluated. It can be said that the smaller the number of peeled substrates, the better the adhesion. The width of the intermediate region of the recording film forming portion was directly observed with an optical microscope and measured. In addition, as a reliability evaluation of the disk, a ByER (Byte) after being left for 2000 hours under a high temperature and high humidity condition of 80 ° C. and 85%.
The Error Rate was measured.

(Example 2.3) The clearance between the film-forming mask used and the substrate was 0.4 mm for X and 0.2 for Y.
mm (Example 2), X is 0 mm, Y is 0.2 mm
A magneto-optical disk was manufactured in the same manner as in Example 1 except that (Example 3) was used. (Comparative Examples 1 to 3) Regarding the clearance between the film forming mask and the substrate, X is 0.6 mm, Y is 0.2 mm (Comparative Example 1), and X is 0.8 mm and Y is 0.2 mm (Comparative Example 2). A magneto-optical disk was manufactured in the same manner as in Example 1 except that The above results are summarized in Table 1.

[Table 1] From Table 1, according to the present invention, a high adhesion between the organic protective film and the recording film can be obtained, and a magneto-optical disk capable of maintaining a low ByER even after being exposed to high temperature and high humidity for a long time can be obtained. .

Although the magneto-optical disk has been described in detail above, the same effect can be obtained by manufacturing a write-once optical disk or the like according to the present invention.

[0013]

According to the optical disk film forming method and film forming apparatus of the present invention, high adhesion between the organic protective film and the recording film can be obtained, and a highly reliable optical disk can be obtained.

[Brief description of drawings]

FIG. 1 is a layout view of an example of a mask and a substrate according to the present invention.

FIG. 2 is a schematic view of an outer peripheral end surface portion of a recording film.

[Explanation of symbols]

 1 mask 2 substrate 3 thin film forming surface 4 outer peripheral end face

Claims (2)

[Claims] 1. A mask is arranged to provide a non-film-forming area on the outer peripheral portion of the substrate, and a clearance [mm] between the thin film formation surface of the substrate and the mask is represented by X, and the outer peripheral end face portion of the substrate and the mask. When the clearance [mm] with is expressed by Y,
X and Y are the following equations 0 ≦ X ≦ 0.5 0 <Y ≦ K (T2-T1) × R (wherein, R represents the diameter [mm] of the substrate, and K represents the linear expansion of the substrate. Coefficient [/ ° C.], T1 represents the substrate temperature [° C.] before film formation, and T2 represents the substrate temperature [° C.] during film formation.) A thin film is formed on the substrate. A method for forming an optical disc, comprising: 2. A mask is arranged to provide a non-film-forming area on the outer peripheral portion of the substrate, and a clearance [mm] between the thin film forming surface of the substrate and the mask is represented by X, and the outer peripheral end surface portion of the substrate and the mask. When the clearance [mm] with is expressed by Y, X and Y are expressed by the following formula: 0 ≦ X ≦ 0.5 0 <Y ≦ K (T2-T1) × R (where, R is the substrate (Represents a diameter [mm], K represents a linear expansion coefficient [/ ° C.] of the substrate, T1 represents a substrate temperature [° C.] before film formation, and T2 represents a substrate temperature [° C.] during film formation.) A film forming apparatus for an optical disk, characterized in that