JPH11120613A - Optical recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the recording and reproducing characteristics of information by forming a phase transition type recording film so as to exactly reflect the surface shape of a substrate and forming this phase transition type recording film so as to have good characteristics. SOLUTION: A reflection film 3 consisting of a material essentially consisting of Al and contg. Si at a ratio of 0.4 to 0.8 (wt.%), Fe <=0.7 (wt.%), Cu 0.15 to 0.40 (wt.%), Mn <=0.15 (wt.%), Mg 0.8 to 1.2 (wt.%), Cr 0.04 to 0.35 (wt.%), Zn <=0.25 (wt.%) and Ti <=0.15 (wt.%) is formed on a substrate 1 of a thickness 0.3 to 1.2 (mm). At least the phase transition type recording film 4 is formed thereon and further, a light transparent layer 5 is laminated and formed thereon. The phase transition type recording film 4 is formed on the reflection film 3 via a dielectric film. The light transparent layer 5 may be formed via a dielectric film thereon. The substrate 1 which is formed with rugged parts, such as guide grooves 2, on one main surface 1a side formed with the reflection film 3 may be used as well.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information recording layer on one main surface of a substrate, on which a light transmitting layer is formed. The present invention relates to an optical recording medium for recording and / or reproducing information. For more information,
The present invention relates to an optical recording medium in which excellent recording / reproducing characteristics are ensured by defining the composition of a reflective film forming material.

[0002]

2. Description of the Related Art In recent years, in the field of data recording, researches on optical data recording methods have been conducted in various places.
This optical data recording system enables non-contact recording and reproduction, achieves recording densities that are at least an order of magnitude higher than magnetic recording systems, and is designed for read-only, write-once, and rewritable memory types. It has a number of advantages such as compatibility, and is considered as a system that can realize an inexpensive large-capacity file for a wide range of uses from industrial use to consumer use.

[0003] Among them, in particular, an optical disk corresponding to a read-only type memory format, such as a digital audio disk on which music data is recorded and an optical video disk on which image data is recorded, are widely used.

An optical disc such as the above digital audio disc has an uneven pattern of a transparent substrate having a thickness of about 1.2 (mm) on which an uneven pattern such as pits or grooves indicating data signals is formed. A reflective film made of a metal thin film such as an aluminum film is formed as a recording layer, and a protective film for protecting the reflective film from atmospheric moisture and O ₂ is formed on the reflective film. Is done.

[0005] In addition, a magneto-optical disk and a phase-change optical disk can be cited as those corresponding to the rewritable memory mode.

For example, a phase-change type optical disk corresponding to the above-mentioned rewritable type memory has the following configuration. That is, a transparent dielectric film made of silicon nitride or the like is formed on one main surface of a transparent substrate, a phase change recording film made of a chalcogen compound or the like is formed thereon, and a transparent dielectric film made of silicon nitride or the like is further formed. Thus, a recording layer is formed, and a reflection film such as an aluminum film is formed. Then, light is irradiated from the transparent substrate side to optically record and reproduce information.

[0007] Recently, DVDs (Digital Media) for recording various data such as images, music, computer data and the like have been developed.
digital Versatile Disc,
It is called DVD. ) Is also on the market. In this DVD, the thickness of the substrate is set to about 0.6 (mm) so as to be compatible with an optical system having a short wavelength and to be compatible with an optical system having a high numerical aperture so as to have a high recording density. .

[0008]

In such a situation,
As a next-generation optical recording medium, Japanese Patent Application No. 9-1096
No. 60, NTSC (Nation
al Television System Comm
It has been proposed an optical recording medium capable of recording / reproducing for 4 hours by the (itte) method.

This optical recording medium is capable of recording and reproducing for 4 hours as a home video disk recorder, thereby functioning as a new recording medium in place of a video tape recorder (Video Tape Recorder) which is currently mainstream. It is intended to have. In addition, this optical recording medium may have the same shape and size as a digital audio disc on which music data is recorded, so that the product is easy to use for users familiar with the simplicity and usability of the digital audio disc. ing. Further, in this optical recording medium, by making the shape of a disk, utilizing the speed of access which is the greatest feature of the disk shape, not only a compact and simple recording medium, but also an instant recording and reproduction Various functions such as trick play and editing are also considered.

Therefore, the above-mentioned optical recording medium is required to have a storage capacity of 8 (GB) or more in order to incorporate such various functions.

However, none of the conventional optical recording media has achieved a storage capacity of 8 (GB). For example, even in a DVD having a high storage capacity, the wavelength λ
Is 0.65 (μm), the numerical aperture of the optical system (hereinafter, referred to as NA) is 0.6, and only a storage capacity of 4.7 (GB) is secured.

For example, ECC (Error Colle)
In order to secure a storage capacity of 8 (GB) or more while maintaining the DVD format as the signal format such as the Ction Code) and the modulation method, the following equation 1 must be satisfied.

4.7 × (0.65 / 0.60 × NA / λ) ² ≧ 8 (Equation 1) From the above equation 1, it is necessary that NA / λ ≧ 1.20. . That is, it is necessary to shorten the wavelength or increase the NA.

Here, for example, when the NA is increased, it is necessary to reduce the thickness of a portion through which the reproduction light is irradiated and transmitted. This is because with the increase in NA, the allowable amount of aberration generated by an angle (tilt angle) at which the disc surface deviates from the perpendicular to the optical axis of the optical pickup becomes smaller. This is because the larger the thickness of the portion through which the reproduction light is transmitted, the larger the thickness.

[0015] For the same reason, it is necessary to keep the variation in the thickness of the portion through which the reproduction light is transmitted within a predetermined range.

Therefore, in the above-mentioned optical recording medium, for example, an uneven portion is formed on one main surface of a substrate, a reflective film is provided thereon to form a recording layer, and a thin film that transmits light is further formed thereon. A light-transmitting layer, and reproducing data from the recording layer by irradiating reproduction light from the light-transmitting layer side, or providing a reflective film on one main surface of the substrate, and at least magneto-optical A recording layer is formed by forming a recording film or a phase-change type recording film, and a light transmitting layer, which is a thin film that transmits light, is provided thereon, and light is irradiated from the light transmitting layer side to the recording layer. Data is recorded and reproduced. With this configuration, it is possible to cope with an increase in the NA of the optical system by reducing the thickness of the light transmission layer.

For example, the thickness t of the light transmitting layer is set to 10 to 177.
(Μm), and the variation in the thickness of the light transmitting layer is Δt (μm).
m), the reproduction of information on the optical recording medium and / or
Alternatively, if the relationship as shown in the following equation 2 is established between the NA of the optical system for recording and the wavelength λ (μm), the storage capacity becomes 8
(GB), and it is possible to increase the recording capacity by using a recording and reproducing device similar to a conventional recording and reproducing device.

Δt = ± 5.26 (λ / NA ⁴ ) (Equation 2) By the way, among the above-described optical recording media, for example, an optical recording medium having a phase-change recording film is manufactured. For example, a reflective film is formed on the one main surface of the substrate on which a concave and convex portion such as a pit row for information reproduction or a guide groove for guiding a spot light of an optical system for recording and reproducing information is formed on one main surface. Is formed by ordinary vacuum thin film forming means such as a sputtering method. Then, on this, for example, a dielectric film, a phase change type recording film, and a dielectric film are sequentially laminated to form a recording layer, and a light transmitting layer is formed thereon.

That is, in the optical recording medium having the light transmitting layer as described above, it is relatively difficult to accurately reflect the uneven portion of the substrate on the phase change type recording film, and the recording / reproducing characteristics of information are impaired. I will be.

On a transparent substrate having an uneven portion on one main surface, a recording layer formed by sequentially laminating, for example, a dielectric film, a phase change recording film, and a dielectric film is provided on the one main surface. In the above-described optical recording medium in which a film is provided and light for recording and / or reproducing information is irradiated from the transparent substrate side, the thickness between the substrate and the phase-change recording film is at most about 100 (nm). Only the dielectric film is interposed. For this reason, the phase-change recording film is formed by accurately reflecting the uneven portions of the substrate.

However, in the above-described optical recording medium having a light transmitting layer, a reflective film and a dielectric film are interposed between one main surface of the substrate on which the uneven portions are formed and the phase change type recording film. Since the total thickness is less than about 200 (nm), it is relatively difficult to accurately reflect the irregularities of the substrate on the phase change recording film.

Further, in the optical recording medium having the light transmitting layer, the surface property of the substrate affects the crystallinity of the reflection film, and the crystallinity of the reflection film affects the characteristics of the phase change recording film. In addition, information recording / reproducing characteristics are impaired.
Further, the interface shape formed by the particle size depending on the composition of the reflection film also affects the characteristics of the phase change type recording film, and the information recording / reproducing characteristics are impaired.

Further, the interface shape formed by the crystallinity of the reflective film and the particle size depending on the composition of the reflective film also affects the surface shape of the phase change type recording film. It becomes more difficult to accurately reflect the irregularities of the substrate, and the recording / reproducing characteristics of information are impaired.

Accordingly, the present invention has been proposed in view of the conventional situation, and the phase change type recording film is formed to accurately reflect the surface shape of the substrate, and the phase change type recording film has good characteristics. An object of the present invention is to provide an optical recording medium which is formed and has good information recording / reproducing characteristics.

[0025]

In order to solve the above-mentioned problems, an optical recording medium according to the present invention has a thickness of 0.3 to 1.2.
(Mm) substrate, a reflective film is formed, and at least a phase change recording film is formed on the reflective film, and a thickness of 1 mm is formed thereon.
An optical recording medium in which a light transmission layer of 0 to 177 (μm) is formed, wherein the reflective film contains Al as a main component, 0.4 to 0.8 (% by weight) of Si, and 0.1 to 0.1% of Fe. 7 (% by weight) or less, Cu is 0.15 to 0.40 (% by weight), and Mn is 0.1% or less.
15 (% by weight) or less; 0.8 to 1.2 (% by weight) of Mg; 0.04 to 0.35 (% by weight) of Cr; 0.25 (% by weight) of Zn; It is characterized by being made of a material contained in a proportion of 15 (% by weight) or less.

In the optical recording medium according to the present invention, a phase-change recording film is formed on a reflection film via a dielectric film, and a light transmission layer is formed on the phase change type recording film via a dielectric film. Is preferred.

Incidentally, in the optical recording medium of the present invention, an uneven portion may be formed on the reflection film forming surface side of the substrate.

In the optical recording medium according to the present invention, Al is a main component, Si is 0.4 to 0.8 (% by weight), Fe is 0.7 (% by weight) or less, and Cu is 0.15-
0.40 (% by weight), Mn is 0.15 (% by weight) or less,
0.8 to 1.2 (wt%) of Mg, 0.04 to Cr
0.35 (% by weight), Zn is 0.25 (% by weight) or less,
A reflective film made of a material containing Ti at a ratio of 0.15 (% by weight) or less is formed, and a reflective film having good surface properties is formed. Therefore, when at least a phase change type recording film is formed thereon, the phase change type recording film is hardly affected by the interface shape formed by the crystallinity of the reflection film and the particle size depending on the composition of the reflection film. , Which accurately reflects the surface shape of the substrate and has good characteristics.

The same applies to the case where a phase change type recording film is formed on a reflective film via a dielectric film. The phase change type recording film accurately reflects the surface shape of the substrate and has a characteristic. Well formed.

In the optical recording medium of the present invention,
Even when a substrate having an uneven portion formed on the reflective film forming surface side is used as the substrate, since the reflective film has the above composition and good surface properties, the phase change type recording film is a crystal of the reflective film. It is hardly affected by the interface shape formed by the particle size depending on the properties and the composition of the reflective film, and is formed by accurately reflecting the surface shape of the substrate having the unevenness.

[0031]

Embodiments of the present invention will be described below with reference to the drawings. Here, an example in which the present invention is applied to a disk-shaped recording medium will be described. However, the present invention is not limited to such a structure, and can be applied to a card-shaped or sheet-shaped recording medium.

The optical recording medium of this embodiment is, as shown in FIG.
On one main surface 1a of a substrate 1, a reflection film 3, a phase change recording film 4, and a light transmission layer 5 are sequentially laminated.

The substrate 1 is made of glass, plastic, or the like, has a thickness of 0.3 to 1.2 (mm), and performs pit rows for information reproduction or information recording / reproduction on one main surface 1a side. Having an uneven portion such as a guide groove provided for the purpose of guiding an optical spot (here, only the guide groove 2 is shown). Then, the track pitch of the guide groove 2 is P, the skew of the substrate 1 is Θ, the numerical aperture of an optical pickup for reproducing or recording / reproducing information on an optical recording medium is NA, the light source wavelength is λ, and If the thickness is t,
The recording capacity of 8 (GB) is achieved by satisfying the relations of the following expressions (3) to (6).

P ≦ 0.64 (μm) (Expression 3) Θ ≦ ± 84.115 (λ / NA ³ / t) (Expression 4) λ ≦ 0.64 (μm) (Equation 5) NA / λ ≧ 1.20 (Equation 6) In the optical recording medium of this embodiment, in particular, the substrate 1
The reflective film 3 is formed on one main surface 1a on which the guide groove 2 is formed. The reflective film 3 contains Al as a main component, and contains 0.4 to 0.8 (% by weight) of Si. Fe 0.7
(% By weight) or less, Cu is 0.15 to 0.40 (% by weight), Mn is 0.15 (% by weight) or less, and Mg is 0.8 to 0.8%.
1.2 (% by weight), Cr: 0.04 to 0.35 (% by weight), Zn: 0.25 (% by weight) or less, Ti: 0.15%
(Weight%) Thickness 50 made of a material contained in the following ratio
It is formed as a thin film of up to 200 (nm). As a method of forming the reflection film 3 on the substrate 1 by using the above-mentioned materials,
Examples of the method include an ion beam sputtering method, a DC sputtering method, and an RF sputtering method, and an ion beam sputtering method is preferably exemplified.

The phase-change recording film 4 is made of a chalcogen compound or a single chalcogen and has a thickness of 10 to 30 (n).
m) is formed as a thin film.

The light transmitting layer 5 may be formed similarly to the light transmitting layer of this type of optical recording medium. However, in the optical recording medium of this example, when the thickness of the light transmitting layer 5 is t and the variation in the thickness of the light transmitting layer is Δt, the following expressions (7) and (8) are satisfied. The light transmitting layer 5 is formed as described above.

10 (μm) ≦ t ≦ 177 (μm) Expression (7) Δt ≦ ± 5.26 (λ / NA ⁴ ) Expression (8) That is, in the optical recording medium of this example, , On the substrate 1,
Al as a main component, 0.4 to 0.8 (% by weight) of Si,
Fe is 0.7 (% by weight) or less, and Cu is 0.15 to 0.4.
0 (% by weight), Mn is 0.15 (% by weight) or less, Mg is 0.8 to 1.2 (% by weight), Cr is 0.04 to 0.35.
(Weight%), a reflective film 3 made of a material containing Zn at a ratio of 0.25 (% by weight) or less and Ti at a ratio of 0.15 (% by weight) or less is formed, and the reflective film has good surface properties. 3 is formed. Therefore, the phase-change recording film 4 formed thereon is hardly affected by the interface shape formed by the crystallinity of the reflective film 3 and the particle size depending on the composition of the reflective film 3. It accurately reflects the shape and has good characteristics.

In the optical recording medium of the present embodiment,
As the substrate 1, a substrate having a main surface 1a on which a reflective film 3 is formed by lamination and having an uneven portion such as a guide groove 2 is used. Therefore, the phase change type recording film 4 is formed by accurately reflecting the surface shape having the uneven portion such as the guide groove 2 of the substrate.

As an optical recording medium according to the present invention, FIG.
And the like. That is, the optical recording medium has substantially the same configuration as that of the optical recording medium shown in FIG. 1, the reflective film 13 is formed on one main surface 11 a of the substrate 11, and the first dielectric layer 16 A phase change type recording film 14 is formed,
Further, the light transmitting layer 1 is further provided thereon via a second dielectric layer 17.
5 is formed by lamination.

The substrate 11 is a substrate made of glass, resin or the like and having a thickness of 0.3 to 1.2 (mm), similarly to the substrate 1 of the optical recording medium shown in FIG. The main surface 1a has an uneven portion such as a guide groove provided for guiding an information reproducing pit row or an optical spot for recording and reproducing information (only the guide groove 12 is shown here). The substrate 11 also satisfies the relations of the above equations (3) to (6) as in the case of the substrate 1 and has a value of 8 (G
The recording capacity of B) is achieved.

Further, the reflection film 13 is also the same as the reflection film 3 of the optical recording medium shown in FIG. 1, and has Al as a main component on one principal surface 11a of the substrate 11 where the guide groove 12 is formed. 0.4 to 0.8 (% by weight) of Si, 0.7 (% by weight) or less of Fe, 0.15 to 0.40 (% by weight) of Cu, and 0.1% of Mn.
15 (% by weight) or less; 0.8 to 1.2 (% by weight) of Mg; 0.04 to 0.35 (% by weight) of Cr; 0.25 (% by weight) of Zn; A thickness of 50 to 200 (n) made of a material contained at a ratio of 15 (% by weight) or less
m) is formed as a thin film. Examples of a method for forming the reflective film 13 on the substrate 11 using the above materials include a method such as an ion beam sputtering method, a DC sputtering method, and an RF sputtering method, and the ion beam sputtering method is preferably exemplified.

Further, similarly to the phase change type recording film 4 of the optical recording medium shown in FIG. 1, the phase change type recording film 14 is formed of a chalcogen compound or a single chalcogen.
It is formed as a thin film of 0 to 30 (nm).

Further, the light transmitting layer 15 is also shown in FIG.
May be formed in the same manner as the light transmitting layer of this type of optical recording medium, similarly to the light transmitting layer 5 of the optical recording medium shown in FIG. Note that also in the optical recording medium of this example, when the thickness of the light transmitting layer 15 is t and the variation in the thickness of the light transmitting layer is Δt, the above expressions (7) and (8) are satisfied. Light transmitting layer 15
Are formed.

In the optical recording medium of the present embodiment, the first dielectric layer 1 is disposed between the reflection film 13 and the phase change type recording film 14.
6, the first dielectric layer 16 is made of A
a thickness of 10 to 30 made of nitrides, oxides, sulfides, and mixtures thereof of metals and metalloids such as l, Si, Zn, etc.
(Nm) thin film.

In the optical recording medium of this embodiment, the second dielectric layer 1 is located between the phase-change recording film 14 and the light transmitting layer 15.
7, the second dielectric layer 17 is made of A
a thickness of 50 to 20 made of nitrides, oxides, sulfides, and mixtures thereof of metals and metalloids such as l, Si, Zn, etc.
It is formed as a thin film of 0 (nm).

In the optical recording medium of this embodiment, similarly to the above-mentioned optical recording medium, the substrate 11 has Al as a main component, Si of 0.4 to 0.8 (% by weight), and Fe of 0.7
(% By weight) or less, Cu is 0.15 to 0.40 (% by weight), Mn is 0.15 (% by weight) or less, and Mg is 0.8 to 0.8%.
1.2 (% by weight), Cr: 0.04 to 0.35 (% by weight), Zn: 0.25 (% by weight) or less, Ti: 0.15%
(Weight%) Reflective film 1 made of a material containing at the following ratio
3 and the reflection film 13 having good surface properties is formed. Then, even if the phase-change recording film 14 is formed on the first dielectric layer 16 with the first dielectric layer 16 interposed therebetween, the phase-change recording film 14 has the crystallinity of the reflection film 13 and the composition of the reflection film 13. It is hardly affected by the interface shape formed by the dependent particle size, and accurately reflects the surface shape of the substrate 11 and has good characteristics.

In the optical recording medium of the present embodiment,
As in the case of the optical recording medium described above, a substrate 11 in which an uneven portion such as a guide groove 12 is formed on one main surface 11a on which a reflective film 13 is laminated is used. Since the surface property is good as the above composition, the phase change type recording film 14 is formed in the guide groove 12 of the substrate.
It is formed by accurately reflecting the surface shape having the uneven portion.

Therefore, in the optical recording media exemplified so far, the phase change type recording films 4 and 14 are formed so as to accurately reflect the surface shape of the substrates 1 and 11, and the phase change type recording films 4 and 14 are formed. Are formed with good characteristics, so that information recording / reproducing characteristics are improved.

[0049]

EXAMPLES Next, in order to confirm the effects of the present invention, the following experiments were conducted.

First, a disk-shaped optical recording medium having the structure shown in FIG. 2 was manufactured. That is, a 1.2 (mm) -thick polycarbonate substrate on which a guide groove having a track pitch of 1.0 (μm) and a width of 0.5 (μm) is formed on one main surface. A reflective film made of an Al alloy was formed by ion beam sputtering (IBS). The Al alloy contains Al as a main component,
0.6% by weight of Si, 0.3% by weight of Fe, C
u is 0.3 (% by weight), Mn is 0.05 (% by weight), M
g: 1.0 (% by weight), Cr: 0.2 (% by weight), Zn
An alloy containing 0.05% by weight and 0.03% by weight of Ti was used.

Next, a first dielectric layer having a thickness of 10 to 30 made of a mixture of ZnS and SiO ₂ is formed on the reflective film.
(Nm), a thin film of GeSbTe having a thickness of 10 to 30 (nm) was formed thereon as a phase-change recording film. Further, a second dielectric layer having a thickness of 50 to 200 made of a mixture of ZnS and SiO ₂ is formed thereon.
(Nm), a light-transmitting layer made of a UV-curable resin and having a thickness of 100 (μm) is laminated, and information recording (groove recording) is performed on a portion corresponding to the bottom surface of the guide groove. Sample 1 was used.

An optical recording medium was manufactured in the same manner as in Working Sample 1 except that information recording (land recording) was performed in a portion corresponding to a space between adjacent guide grooves, and Working Sample 2 was obtained.

Further, for comparison, an Al-Ti alloy (hereinafter, Al-Ti (hereinafter referred to as Al-Ti ( An optical recording medium was manufactured in the same manner as in Working Sample 1 except that a thin film of (1.5 wt%) was formed by a DC sputtering method.

Furthermore, an optical recording medium similar to Comparative Sample 1 was manufactured except that information recording (land recording) was performed in a portion corresponding to a space between adjacent guide grooves, and Comparative Sample 2 was obtained.

First, the surface roughness of the reflective films of the working sample 1 and the comparative sample 1 was measured by a scanning tunneling microscope. The results are shown in FIG. In FIG. 3, the horizontal axis indicates the distance from the center of the substrate, the vertical axis indicates the height of the reflective film surface from the substrate surface, the solid line indicates the result of the working sample 1, and the broken line indicates the result of the comparative sample 1. As can be seen from the results in FIG. 3, in Comparative Sample 1 in which the reflective film was formed in the same manner as in the conventional optical recording medium, the surface roughness of the reflective film was ± 10%.
In contrast, the surface roughness of the reflective film is ± 3 in the working sample 1 to which the present invention is applied.
(Nm), and it was confirmed that a reflective film having good surface properties was formed by applying the present invention.

Further, information was repeatedly rewritten for the working samples 1 and 2 and the comparative samples 1 and 2, and a change in jitter with respect to the number of times of rewriting was examined. FIG. 4 shows the results. In FIG. 4, the horizontal axis indicates the number of rewrites, and the vertical axis indicates jitter. In addition, ● shows the result of Working Sample 1, ○ shows the result of Working Sample 2, X shows the result of Comparative Sample 1, and Δ shows the result of Comparative Sample 2.
As can be seen from the results in FIG. 4, in Comparative Samples 1 and 2 in which a reflective film is formed in the same manner as in the conventional optical recording medium, if the number of rewrites exceeds 1,000, the jitter exceeds 15 (%). On the other hand, in the working samples 1 and 2 to which the present invention is applied, the number of rewrites is 1000
At about 0 times, the jitter was suppressed to 15% or less, and it was confirmed that the rewriting durability was excellent.
Further, from this, the working sample 1 to which the present invention was applied,
In No. 2, it is possible to guarantee 10,000 or more rewritable times.

Further, when the disk noise at 500 (kHz) was measured for the above-mentioned sample 1 and comparative sample 1, the disk noise of sample 1 was 4.5 than that of comparative sample 1.
(DB) It was low.

From the above, in the optical recording medium to which the present invention is applied, the phase change type recording film is formed accurately reflecting the surface shape of the substrate, and the phase change type recording film is formed with good characteristics. It was confirmed that the information recording / reproducing characteristics were good.

[0059]

As described above, in the optical recording medium according to the present invention, Al is used as the main component, and Si is added to the optical recording medium.
4 to 0.8 (% by weight), Fe is 0.7 (% by weight) or less,
0.15 to 0.40 (% by weight) of Cu and 0.15 of Mn
(% By weight): 0.8 to 1.2 (% by weight) of Mg;
r is 0.04 to 0.35 (% by weight), Zn is 0.25
(% By weight) or less, a reflective film made of a material containing Ti in a ratio of 0.15 (% by weight) or less is formed, and a reflective film having good surface properties is formed. Therefore, when at least a phase change type recording film is formed thereon, the phase change type recording film is hardly affected by the interface shape formed by the crystallinity of the reflection film and the particle size depending on the composition of the reflection film. , Which accurately reflects the surface shape of the substrate and has good characteristics.

The same applies to the case where a phase change type recording film is formed on a reflection film via a dielectric film. The phase change type recording film accurately reflects the surface shape of the substrate and has a characteristic. Well formed.

In the optical recording medium of the present invention,
Even when a substrate having an uneven portion formed on the reflective film forming surface side is used as the substrate, since the reflective film has the above composition and good surface properties, the phase change type recording film is a crystal of the reflective film. It is hardly affected by the interface shape formed by the particle size depending on the properties and the composition of the reflective film, and is formed by accurately reflecting the surface shape of the substrate having the unevenness.

That is, the present invention can provide an optical recording medium having good information recording / reproducing characteristics.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of a main part showing a configuration of an example of an optical recording medium according to the present invention.

FIG. 2 is a schematic cross-sectional view of a main part showing a configuration of another example of the optical recording medium according to the present invention.

FIG. 3 is a characteristic diagram showing a relationship between a distance from a center of a substrate and a height of a reflection film surface from a substrate surface.

FIG. 4 is a characteristic diagram showing the relationship between the number of times of rewriting and jitter.

[Explanation of symbols]

1,11 substrate, 1a, 11a one main surface, 2,12 guide groove, 3,13 reflection film, 4,14 phase change type recording film,
5, 15 light transmitting layer, 16 first dielectric layer, 17 second dielectric layer

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kotaro Kurokawa 6-7-35 Kita Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation

Claims (3)

[Claims] 1. A reflection film is formed on a substrate having a thickness of 0.3 to 1.2 (mm), at least a phase change recording film is formed on the reflection film, and a thickness of 10 to 177 is formed thereon. (Μm)
In the optical recording medium in which the light transmitting layer is formed, the reflective film has Al as a main component and Si has a thickness of 0.4 to 0.2.
8 (wt%), Fe is 0.7 (wt%) or less, Cu is 0.15 to 0.40 (wt%), Mn is 0.15 (wt%) or less, and Mg is 0.8 to 1. 2 (% by weight), a material containing 0.04 to 0.35 (% by weight) of Cr, 0.25 (% by weight) or less of Zn, and 0.15 (% by weight) or less of Ti An optical recording medium characterized by the above-mentioned. 2. The method according to claim 1, wherein a phase change type recording film is formed on the reflection film via a dielectric film, and a light transmission layer is formed on the phase change type recording film via the dielectric film. 2. The optical recording medium according to 1. 3. The optical recording medium according to claim 1, wherein an uneven portion is formed on the reflection film forming surface side of the substrate.