JP2002172861A - Optical information recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical information recording medium having a sufficient reflectivity at a film forming time and a high C/N(carrier/noise) at a low cost. SOLUTION: Cu is a metal having a high reflectivity, but since the reflectivity is high, Cu cannot absorb a light, and hence cannot achieve a perforation recording. Therefore, at least one type of an element selected from the group consisting of group 4B, group 5B and group 6B of a low energy gap material is added to CU in view of an energy gap of a substance. Hence, a recording film having a lower absorption end than an illuminating laser can be formed. Thus, the perforation recording by absorbing the illuminating layer has succeeded with the recording film having the high reflectivity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an optical information recording medium, and more particularly, to an optical information recording medium capable of recording / reproducing by causing an optical change in a recording layer by irradiation with an energy beam.

[0002]

2. Description of the Related Art There are write-once optical information recording media such as CD-R and DVD-R as recordable optical information recording media by laser beam irradiation. These optical information recording media have reproduction compatibility with CD-ROM or DVD-ROM, and are used as small-scale distribution media and storage media.

[0003]

However, CD-R, D
VD-R has a problem that the production cost is significantly higher than that of the ROM process because an organic dye is applied. Therefore, CD-write once (hereinafter referred to as WO), DVD-WO
Media has been developed. WO media includes a drilling type, a phase change type, and an alloying type. In the phase change type, as described in JP-A-3-240589, Sb2
A method using S3 and using Au for the reflective film has been devised. However, this configuration requires two types of sputtering, and a standard production line for ROM cannot be used, and a special production line must be prepared. Cost was rising.
Similarly, in the alloying type, there is an invention in Japanese Patent Application Laid-Open No. Hei 5-225606 in which a laminated structure of bismuth and tellurium is used to form an alloy together with recording, so that the film has a film thickness ratio at which the spectral reflectance is reduced. However, this invention also provides a standard R by sputtering two or more layers in the same manner as the phase change type.
An OM production line could not be used, and the cost increased by preparing a special production line.

[0004] From the viewpoint of cost, a perforated recording system is promising, but there is a problem that the perforated recording results in a low C / N. This was due to the fact that the film melted in the pit portion where the hole was formed remained in the pit as a polka dot or swelled in the peripheral portion. Further, in the case of the perforated recording method, the layer configuration is one layer. However, the recording film that has been usually used cannot cope with the high reflectance of the ROM and has been a nonstandard product. In order to realize a high reflectivity corresponding to ROM with a single recording film layer, Al, Ag, Cu and the like are conceivable. However, the reflectivity was too high, and a hole was not formed by very ordinary laser irradiation. These problems have been a major obstacle to the spread of inorganic WO recording media.

The present invention has been made to solve such problems in the prior art, and an optical information recording medium having a sufficient reflectance at the time of film formation and having a high C / N (carrier / noise) is provided. The purpose is to provide it at low cost.

[0006]

According to the first aspect of the present invention, there is provided an optical information recording medium capable of recording / reproducing by irradiating an energy beam, wherein one recording layer is provided on a transparent substrate. In a substrate provided with an ultraviolet curable resin layer on a recording layer, the recording layer is mainly composed of Cu and a 4B group, a 5B group,
High reflectance by containing at least one element selected from the group 6B and at least one element selected from the group 4B, 5B and 6B in the range of 2 to 40 atm%. Has succeeded in providing an optical information recording medium having a high modulation value and a high C / N at low cost. That is, although Cu is a metal having a high reflectivity, it was not possible to absorb light because of its high reflectivity, and it was not possible to perform perforation recording. Therefore, focusing on the energy gap of the substance, it is a low energy gap material 4
By adding at least one element selected from the group B, the group 5B, and the group 6B to Cu, a recording film having an absorption edge lower than that of the irradiation laser could be formed. As a result, despite the high reflectance recording film, the irradiation laser was absorbed and the hole recording was successfully performed.

Also, an optical information recording medium capable of recording / reproducing by irradiation of an energy beam, wherein a recording layer is provided on a transparent substrate and an ultraviolet curing resin layer is provided on the recording layer In the above, the recording layer is mainly made of Cu and Sn
An optical information recording medium having high reflectance, a high modulation value, and a high C / N ratio was successfully provided at a low cost by including Sn in the range of 2 to 40 atm%. An optical information recording medium capable of recording / reproducing by irradiation of an energy beam, wherein a recording layer is provided on a transparent substrate and an ultraviolet curable resin layer is provided on the recording layer. Contains mainly two elements of Cu and Ge, and Ge has a high reflectance and a high modulation value when Ge is in a range of 2 to 40 atm%, and has a high C /
It succeeded in providing an optical information recording medium having N at low cost. An optical information recording medium capable of recording / reproducing by irradiation of an energy beam, wherein a recording layer is provided on a transparent substrate and an ultraviolet curable resin layer is provided on the recording layer. Contains mainly two elements of Cu and Se, and when Se is in the range of 2 to 40 atm%, an optical information recording medium having high reflectance, high modulation value, and high C / N is provided at low cost. Succeeded.
An optical information recording medium capable of recording / reproducing by irradiation of an energy beam, wherein a recording layer is provided on a transparent substrate and an ultraviolet curable resin layer is provided on the recording layer. Contains mainly two elements Cu and Bi, and B
When i is in the range of 2 to 40 atm%, an optical information recording medium having high reflectance, high modulation value, and high C / N has been successfully provided at low cost. An optical information recording medium capable of recording / reproducing by irradiation of an energy beam, wherein a recording layer is provided on a transparent substrate and an ultraviolet curable resin layer is provided on the recording layer. Contains mainly two elements of Cu and Sb, and when Sb is in the range of 2 to 40 atm%, an optical information recording medium having high reflectance, high modulation value, and high C / N is provided at low cost. Succeeded. An optical information recording medium capable of recording / reproducing by irradiation with an energy beam, wherein a recording layer is provided on a transparent substrate and an ultraviolet curable resin layer is provided on the recording layer. Contains mainly two elements Cu and Te, and Te is 2 to 4
An optical information recording medium having a high reflectance, a high modulation value, and a high C / N was successfully provided at a low cost by setting the range to 0 atm%. An optical information recording medium capable of recording / reproducing by irradiation of an energy beam, wherein a recording layer is provided on a transparent substrate and an ultraviolet curable resin layer is provided on the recording layer. Contains mainly two elements, Cu and Pb, and Pb is 2 to 40 at.
By setting it in the range of m%, an optical information recording medium having high reflectance, high modulation value, and high C / N was successfully provided at low cost. An optical information recording medium capable of recording / reproducing by irradiation with an energy beam, wherein a recording layer is provided on a transparent substrate and an ultraviolet curable resin layer is provided on the recording layer. Contains mainly two elements of Cu and In, and provides an optical information recording medium having high reflectance, a high modulation value, and a high C / N at a low cost by making In a range of 2 to 40 atm%. Succeeded.

Further, in the optical information recording medium of the present invention,
By setting the laser power at the time of recording to 6 mW to 12 mW, damage to the track at the time of punching recording was small, and recording of polka dots with a large C / N without swelling around the pit could be realized. Further, in the optical information recording medium of the present invention, a film having a high C / N ratio can be obtained because the recording layer has a thickness of 100 to 350 A, so that the reflectance and sensitivity are high, and the pit periphery is less prominent. I was able to. In the present invention, disposing a transparent dielectric film between the recording film and the transparent substrate results in a two-layer film, which increases the cost.
We succeeded in M compatibility.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the optical information recording medium of the present invention will be described below in detail with reference to FIGS. FIG. 1 illustrates a configuration in which the optical information recording medium according to the present embodiment is applied to a DVD. As illustrated in FIG. 1, in the optical information recording medium, a recording layer 12 is formed on an information substrate (transparent substrate) 11 and an ultraviolet curable resin layer 13 is laminated. This has a structure in which the cover substrate 15 and the cover substrate 15 are bonded by the bonding layer 14.

The material of the information substrate 11 is usually glass, ceramics, or resin, and a resin substrate is preferable in terms of moldability. Representative examples include polycarbonate, acrylic, epoxy, polystyrene, polypropylene, silicon, fluororesin, ABS resin, urethane, etc., but polycarbonate resins are preferred from the viewpoint of workability, optical characteristics, and the like. Further, the shape of the substrate may be a disk shape, a card shape, or a sheet shape. For the bonding method, radical UV method, cationic method,
There is no particular limitation on either the heat sealing method or the double-sided adhesive sheet method, but in a configuration in which the ultraviolet curable resin layer 13 is not provided, a method that does not transmit oxygen or moisture, such as a radical UV method, is desirable. The recording layer 12 of the present embodiment can be formed by various vapor deposition methods, for example, a vacuum deposition method, a sputtering method, an electron beam method, or the like.

Hereinafter, the configuration of the present invention will be described based on embodiments. (1) First Example A recording layer Cu 90Sn10 30 nm of the present embodiment is sputtered on a polycarbonate resin information substrate having a groove having a pitch of 0.74 μm, a depth of 40 nm (40 Å), a thickness of 0.6 mm, and a diameter of Φ120 mm. The layers were laminated by a method, and a UV-curable resin layer was spin-coated thereon and formed by UV irradiation. The bonding was performed by bonding the cover substrate by a radical UV method. The evaluation condition was a recording linear velocity of 3.5.
m / s, linear density = 0.267 μm / bit, recording laser wavelength 635 nm, NA = 0.6, and the results of C / N, production cost, sensitivity (recording power exceeding 50 dB), and reflectivity are shown in FIG. Show.

(2) Second Embodiment A recording layer of the present invention Cu 90 Ge 10 30 nm on a substrate
Is the same as Example 1 except that was laminated by sputtering. FIG. 6 shows the results.

(3) Third Embodiment A recording layer of the present invention Cu 90Se10 30 nm on a substrate
Is the same as Example 1 except that was laminated by sputtering. FIG. 6 shows the results.

(4) Fourth Embodiment A recording layer of the present invention Cu 90 Bi10 30 nm on a substrate
Is the same as Example 1 except that was laminated by sputtering. FIG. 6 shows the results.

(5) Fifth Embodiment Recording layer of the present invention Cu 90 Sb10 30 nm on substrate
Is the same as Example 1 except that was laminated by sputtering. FIG. 6 shows the results.

(6) Sixth Embodiment A recording layer of the present invention Cu 90Te10 30 nm on a substrate
Is the same as Example 1 except that was laminated by sputtering. FIG. 6 shows the results.

(7) Seventh Embodiment Recording layer Cu 90 Pb10 30 nm according to the present invention on a substrate
Is the same as Example 1 except that was laminated by sputtering. FIG. 6 shows the results.

(8) Eighth Embodiment FIG. 2 shows a configuration example of an optical information recording medium according to an eighth embodiment. As illustrated in FIG. 2, a transparent dielectric layer 16 was provided between the recording layer 12 and the transparent substrate 11. The thickness of the transparent dielectric layer 16 in this embodiment is 20
nm. The other configuration is the same as that of the first embodiment illustrated in FIG. FIG. 6 shows the results.

FIG. 3 shows the ratio of Sn in Cu Sn and C / N
Is a representative representation of the relationship. Write conditions are 3T rectangular wave, 8mW, linear density 0.267μm / bit
It is. The inventors set the quality standard to be 50 dB or more, but exceeded 50 dB in the range of Sn = 2 to 40. Other additives showed basically the same effect.

FIG. 4 shows the relationship between the writing power of a 3T rectangular wave to Cu90Sn10 and C / N. 50 in the range of writing power 6 to 12 mW
Exceeded dB. Other additives showed basically the same effect.

FIG. 5 shows the film thickness of Cu 90 Sn10 and C / S
It shows the relationship with N. The film thickness is 10 to 35 nm
In the range of 50 dB. Other additives showed basically the same effect.

[0022]

According to the present invention, an optical information recording medium having a sufficient reflectance at the time of film formation and having a high C / N (carrier / noise) can be provided at low cost.

[Brief description of the drawings]

FIG. 1 is a configuration diagram when an optical information recording medium according to an embodiment of the present invention is applied to a DVD.

FIG. 2 is a configuration diagram of an eighth example of the present embodiment.

FIG. 3 is an explanatory diagram representatively showing the relationship between the Sn ratio of Cu Sn and C / N.

FIG. 4 is an explanatory diagram showing a relationship between a writing power to a Cu 90Sn10 in a 3T rectangular wave and C / N.

FIG. 5 is an explanatory diagram showing the relationship between the thickness of Cu 90Sn10 and C / N.

FIG. 6 is an explanatory diagram showing evaluation results for each example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Information board 12 Recording layer 13 Ultraviolet effect resin layer 14 Adhesive layer 15 Cover substrate 16 Transparent dielectric layer

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H111 EA03 FA01 FA21 FB04 FB05 FB06 FB07 FB08 FB09 FB10 FB12 FB15 FB17 FB21 5D029 JA01 JB28 JC02 MA13

Claims (12)

[Claims] 1. An optical information recording medium capable of recording / reproducing by irradiation with an energy beam, wherein a recording layer is provided on a transparent substrate and an ultraviolet curable resin layer is provided on the recording layer. Wherein the recording layer mainly contains Cu and two elements of at least one element selected from the group consisting of 4B, 5B and 6B.
An optical information recording medium, characterized in that at least one element selected from the group consisting of group 5, group 5B and group 6B is in the range of 2 to 40 atm%. 2. An optical information recording medium capable of recording / reproducing by irradiation of an energy beam, wherein a recording layer is provided on a transparent substrate, and an ultraviolet curable resin layer is provided on the recording layer. In the above, the recording layer mainly contains two elements of Cu and Sn, and Sn is 2 to 2.
An optical information recording medium having a range of 40 atm%. 3. An optical information recording medium capable of recording / reproducing by irradiating an energy beam, wherein a recording layer is provided on a transparent substrate and an ultraviolet curable resin layer is provided on the recording layer. In the above, the recording layer mainly contains two elements of Cu and Ge,
An optical information recording medium having a range of 40 atm%. 4. An optical information recording medium capable of recording / reproducing by irradiating an energy beam, wherein a recording layer is provided on a transparent substrate, and an ultraviolet curable resin layer is provided on the recording layer. In the above, the recording layer mainly contains two elements of Cu and Se, and Se is 2 to 2.
An optical information recording medium having a range of 40 atm%. 5. An optical information recording medium capable of recording / reproducing by irradiation with an energy beam, wherein a recording layer is provided on a transparent substrate, and an ultraviolet curable resin layer is provided on the recording layer. In the above, the recording layer mainly contains two elements of Cu and Bi,
An optical information recording medium having a range of 40 atm%. 6. An optical information recording medium capable of recording / reproducing by irradiation with an energy beam, wherein a recording layer is provided on a transparent substrate and an ultraviolet curable resin layer is provided on the recording layer. In the above, the recording layer mainly contains two elements of Cu and Sb,
An optical information recording medium having a range of 40 atm%. 7. An optical information recording medium capable of recording / reproducing by irradiating an energy beam, wherein a recording layer is provided on a transparent substrate, and an ultraviolet curable resin layer is provided on the recording layer. In the above, the recording layer mainly contains two elements of Cu and Te, and Te is 2 to 2.
An optical information recording medium having a range of 40 atm%. 8. An optical information recording medium capable of recording / reproducing by irradiating an energy beam, wherein a recording layer is provided on a transparent substrate, and an ultraviolet curable resin layer is provided on the recording layer. In the above, the recording layer mainly contains two elements of Cu and Pb, and Pb is 2 to 2.
An optical information recording medium having a range of 40 atm%. 9. An optical information recording medium capable of recording / reproducing by irradiating an energy beam, wherein a recording layer is provided on a transparent substrate, and an ultraviolet curable resin layer is provided on the recording layer. In the above, the recording layer mainly contains two elements of Cu and In, and In is 2 to 2.
An optical information recording medium having a range of 40 atm%. 10. A laser power at the time of recording is 6 mW.
The optical information recording medium according to any one of claims 1 to 9, wherein the optical information recording medium has a power of up to 12 mW. 11. The optical information recording medium according to claim 1, wherein the recording layer has a thickness of 10 to 35 nm. 12. The optical information recording medium according to claim 1, wherein a transparent dielectric film is disposed between the recording film and a transparent substrate. .