JP2003272235A - Phase change type optical information recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a phase change type optical disk with less reproduction deterioration and having a high C/N. <P>SOLUTION: The phase change type optical information recording medium 10 provided with at least a reflection layer 2, a first protective layer 3, a phase change recording layer 4, a second protective layer 5, and a transparent layer on a substrate on which guide grooves or pits are formed, is characterized in that an optical attenuation layer 6 the transmissivity with respect to an emitted light of which is selected to be 95% to 50% is provided between the second protective layer 5 and the transparent layer 9. <P>COPYRIGHT: (C)2003,JPO

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] [0001] The present invention relates to optically recording information.
Recording / reproducing phase-change optical information recording medium (phase-change optical
Disc). [0002] 2. Description of the Related Art In recent years, the recording density of a phase change optical disk has been increased.
There is a growing demand for higher-capacity recording media
You. The linear recording density of an optical disc is determined by the laser
It largely depends on the wavelength and the numerical aperture of the objective lens. sand
That is, the laser wavelength λ of the reproducing optical system and the aperture of the objective lens
When the number NA is determined, the beam spot diameter is determined.
Approximately 2NA / λ can be detected for spatial frequency during signal reproduction
It will be the limit. [0003] Therefore, it is possible to increase the density of a conventional optical disc.
To achieve this, shorten the laser wavelength of the reproduction optical system,
It is necessary to increase the NA of the objective lens. For this reason,
Improve the recording density by devising the recording medium configuration and reading method.
Improvements are being made for improved technologies. [0004] As one of the prior arts, the incidence of a recording layer is reduced.
A layer having an optically nonlinear property is provided on the light side,
A disk super-resolution technique is known. For example, JP-A-6-
Japanese Patent No. 111330 discloses that, in addition to the recording layer,
On the other hand, it has a nonlinear optical effect layer that exhibits the nonlinear optical effect.
The reproducing light and the recording light are used as described above.
The recording layer is irradiated through the non-linear optical effect layer and further irradiated.
The peak intensity of the reproduction light is changed to the peak intensity of the recording light.
Recording / reproducing method and optical recording medium set to be substantially the same
Is described. [0005] The present invention provides a super-resolution effect described herein.
Rather than simply attenuating the incident light.
Phase change with high C / N without regeneration deterioration
It is intended to provide a type optical disk. [0006] SUMMARY OF THE INVENTION Wavelength 400 to 410n
gallium nitride (GaN)
Semiconductor lasers are currently under development, but laser
Is high. In particular, do not destroy pits recorded during playback.
If the laser power is reduced as
C / N decreases. Re-set to reduce laser noise
Increasing raw power causes thermal damage to the recording layer. Phase change
Erasing amorphous recording marks
become. As will be described later, the high density of the optical disc
Violet wavelength of 400-420 nm
Research and development using a user for recording and playback is ongoing.
As described above, when the density is increased, the optical disk
The diameter of the light spot formed on the surface of the
The energy density of the emitted light increases,
It is inevitable that the allowable range of the reproduction power becomes narrow. [0008] The present invention addresses the problems of the prior art.
It was made to solve the problem
Reduces noise during playback with violet laser and reduces
Phase-change light with high C / N even when using phase-change material
The purpose is to provide a disk. Further, the reproducing power margin at the time of reproducing is widened.
Phase-change optical disk that enables stable recording and reproduction
The purpose is to provide. [0010] Means for Solving the Problems According to claim 1 of the present invention,
On the substrate 1 on which the guide grooves or pits are formed,
Both the reflective layer 2, the first protective layer 3, the phase change recording layer 4, the second protective layer
Phase-change optical information recording medium 10 provided with protective layer 5 and transparent layer 9
Between the second protective layer 5 and the transparent layer 9,
Light attenuation with transmittance for irradiation light set to 95-50%
It is characterized in that a layer 6 is provided. [0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below.
Will be described with reference to the accompanying drawings. Note that the actual
Since the embodiment is a preferred specific example of the present invention,
Although various preferred limitations are imposed, the scope of the present invention
Is a statement that the invention is particularly limited in the following description.
However, the present invention is not limited to these embodiments unless otherwise described. The respective embodiments will be described below.
You. First, let us explain the current situation.
Use a high NA lens for high density optical recording media that supports long range
For the reason that it is thought that
Unlike D and DVD, substrates with guide grooves etc.
On top of this, a reflective layer, a first protective layer, a recording layer, and a second protective layer
Are laminated in this order, and a cover layer is provided thereon.
Recording and erasing information by irradiating light from the side
Can achieve excellent recording, reproducing and rewriting characteristics
It is said that actual research and development is also going in that direction
You. The phase change type optical disk 10 according to the present embodiment
Also basically has such a layer configuration.
The specific configuration will be described with reference to FIG. In FIG. 1, reference numeral 1 denotes a guide groove, for example.
Or a substrate on which pits have been formed.
Emissive layer 2, a first protective layer 3 on this reflective layer 2, this first protective
On the layer 3, a phase-change recording layer 4, and on the phase-change recording layer 4,
A second protective layer 5, a light attenuation layer 6 on the second protective layer 5,
An adhesive layer 7 on the light attenuation layer 6 and a cover on the adhesive layer 7
The layers (sheets) 8 are stacked in this order. In addition, adhesion
A transparent layer 9 is formed by the agent layer 7 and the cover layer 8. This
Transparent layer 9 is transparent without adhering a cover layer (sheet).
It can also be composed of resin alone. For example, a laser beam is applied to the substrate 1 described above.
Pre-groove, pre-pit or rewrite
A reproduction signal that cannot be reproduced is provided in an embossed pit. The material of the substrate 1 is polycarbonate, poly
Plastic substrates such as olefins and acrylics and glass substrates
A plate is used. A pre-groove that guides the laser light
Pre-pits can be directly injection molded or stamped
And a smooth first substrate on top
2P method of curing polymer by placing on it (photopolymer method)
Is formed. Also, CAV (constant ang)
(ullarity constant angular velocity) and CLV
(Constant linear yelocity
  Linear velocity) or ZCAV (zone cons)
tang angular elocity) or ZC
LV (zone constant lineary)
format), and the format of each sector
At the beginning, the address signal is pre-recorded as an embossed pit
May be recorded. Information area used by the user
Is composed of empty grooves and wobbled as necessary
You. As a recording method, a groove recording or a
Select either land or land / groove recording.
Selected. When recording on lands and grooves,
And the playback signal of the groove and the groove are the same.
The width of the land and groove is determined. The track pitch is 0.1 μm to 1.6 μm.
m and the groove depth are preferably 10 nm to 200 nm. Concrete
Specifically, the track pitch is 0.32 μm and the groove depth is 18 n
m, groove width is 30% -50% of track pitch
Laser with a wavelength of 400 nm to 420 nm
Then, a high-density optical disk with a capacity of about 20 GB to 27 GB
Can be realized. Next, a film forming procedure will be described. Substrate 1
Is placed in a vacuum chamber, and the reflective layer 2 and the first protective layer 3
And the phase-change recording layer 4, the second protective layer 5, and the light attenuation layer 6 in this order.
Next, they are formed on the substrate 1 in this order. The film formation method is resistance heating
And electron beam type vacuum deposition, DC and AC sputtering
, Reactive sputtering, ion beam sputtering
And ion plating are used. Light attenuation layer 6
When an organic material is used for the
It is also possible. The reflection layer 2 is made of Al, Au, Ag, Cu, N
metal such as i, In, Ti, Cr, Pt, Si, or
Semiconductors, their alloys and semiconductors are used. Metal simple substance
Addition of metal or semiconductor makes crystal grains smaller
It is preferable because it reduces the cost. Also stable under high temperature and high humidity
In order to improve the properties, it is better to include an additive. For example, Al-Ti, Al-Cr, Al-Z
alloys such as r, Al-Si, Ag-Pd-Cu
You. Using a blue semiconductor laser with a wavelength of 400nm
When using an Al-based or Ag-based alloy, higher reflectivity
Obtainable. The first protective layer 3 and the second protective layer 5 are made of gold.
Oxides, nitrides, sulfides and mixtures thereof
It is. For example, ZnS-SiO_Two, ZnS, SiO_Two, T
a_TwoO _Five, Si_ThreeN_Four, AlN, Al_TwoO_Three, AlSiON,
ZrO_Two, TiO_TwoAlone or a mixture of these
Used. The thickness of the first protective layer 3 is smaller than that of the second protective layer 5.
Thin, so-called quenching structure reduces thermal damage
For this purpose, the film thickness is preferably set to 2 nm to 50 nm.
Reduces cross erase by adopting quenching structure
You can do things. Preferably, the deposition rate of the first protective layer 3 is:
The film forming speed of the second protective layer 5 is made slower. Thus, the film forming speed is controlled.
Increase in jitter due to rewriting
The number increases. That is, the deposition rate of the first protective layer 3 is reduced.
The stress remaining in the first protective layer 3
, The mass transfer of the phase change recording layer 4 is suppressed.
This is because the rewriting performance is improved. Reference numeral 4 denotes a phase-change type recording layer,
Phase change using inter-crystal reflectance or refractive index change
Material is used. The phase change type recording layer 4 is made of Ge-
Sb-Te system, Ag-In-Te-Sb system, Cu-Al-Sb
There are alloys mainly composed of Te or Sb such as -Te type.
I can do it. The film thickness of the phase change type recording layer 4 is 10 nm to
100 nm, preferably increasing the recording sensitivity and
In order to increase the number, it is necessary to set the thickness to 10 nm to 30 nm.
Good. The light attenuation layer 6 is made of metal, semiconductor, or gold.
Inorganics such as oxides, nitrides, sulfides and carbides of metals and semiconductors
Organic materials such as materials, dyes, and pigments are used. For example, A
1, Au, Ag, Cu, Ni, In, Ti, Cr, P
Metals or semiconductors such as t, Si, alloys and semi-conductors thereof
Conductors are used. As the light attenuation layer 6, a dielectric (metal or semiconductor)
Oxides, nitrides, sulfides, carbides, etc.)
Is ZnS-SiO_Two, ZnS, SiO_Two, Ta_TwoO_Five, S
i_ThreeN_Four, AlN, GeN, Al_TwoO_Three, AlSiON, Z
rO_Two, TiO_Two, SiC, etc. or these and gold
A mixture with a metal or a semiconductor is used. Further, the light attenuating layer 6 has a cyanine color.
Element, azo dye, leuco dye, spiropyran dye, phthalo
Organic pigments such as cyanine pigments and naphthalocyanine pigments and face
Fees are used. The light attenuating layer 6 is provided for light having a reproduction light wavelength.
It has the function of attenuating strength. The light attenuating layer 6 has absorption for the reproduction light wavelength.
For example, this light reduction is performed so that the transmittance becomes 50%.
By adjusting the absorptance and the film thickness of the decay layer 6, the reproduction power is reduced to 0.1.
With 2 mw, even if the noise is high, the laser emission power
Can be increased to 0.4 mW.
This is a low noise area. If you do this,
The power is controlled by the light attenuation layer 6 on the optical disk surface.
To 50%, which is essentially 0.2 mW of regenerative power.
Laser erase without erasing the phase change recording mark.
This is because only the size can be reduced. On the other hand, recording light is also attenuated during recording.
Therefore, if the transmittance of the light attenuation layer 6 is reduced, the recording power
-High C / N cannot be obtained due to insufficient carbon. Conversely, the light attenuation layer 6
Increasing the transmittance of the
No, noise is not reduced and a high C / N is obtained.
Absent. When the transmittance of the light attenuation layer 6 is 95% or less,
The playback change without erasing the phase change recording mark.
The power can be increased and the laser power is increased
Thereby, laser noise can be reduced. Only
On the other hand, when the transmittance of the light attenuation layer 6 is 50% or less,
When recording, the recording laser power needs more than 10mW
Power that cannot be realized with the current blue-violet laser.
-Area. As described above, the transmittance of the light attenuation layer 6 is set to 95
% And 50% or more, the reproduction laser noise
And the recording power does not run out during recording.
It is clear that both low noise and high recording sensitivity can be achieved.
Call The present inventors have found this point by experiments.
In this case, that is, the transmittance is 9
As a light attenuation layer 6 in a range of 5% or less and 50% or more, a metal material
When using a material, select the absorption rate specific to the metal.
Obtaining the transmittance by controlling the film thickness
Was made. The light attenuating layer 6 is oxidized with a metal or semiconductor.
When using dielectrics such as materials, nitrides, sulfides, and carbides
Controls the content of oxygen, nitrogen, carbon and sulfur
The above transmittance can be obtained by controlling the film thickness.
Wear. Specifically, by changing the sputter input power,
Controls the film deposition rate and controls the
The thickness of the light attenuation layer 6 is controlled by the opening / closing time of the
You. Further, the acid in the argon sputtering gas
When the amount of gas introduced such as nitrogen, methane, etc.
The amount of oxygen, nitrogen and carbon therein increases, and the transmittance increases. Conversely, when the introduced gas amount is reduced,
Decrease the amount of oxygen, nitrogen and carbon. Sulfuric acid
For compounds, target
Prepare and control the composition. Further, an organic dye or pigment is used for the light attenuation layer 6.
The maximum absorption wavelength (λmax) and extinction coefficient
The above transmittance can be obtained by controlling or controlling the film thickness.
Can be The maximum absorption wavelength and extinction coefficient are
Is determined by the child structure, and the structural skeleton or side chain group
Is adjusted to the desired one. The light attenuation layer 6 is formed by vacuum film formation.
However, in the case of an organic control material,
In some cases, it is soluble and spin coating can be used.
You. Next, a transparent layer 9 is provided on the light attenuation layer 6.
You. There are the following two methods for forming the transparent layer 9. 1
One method is to provide a sufficient transmittance for recording / reproducing light.
UV-curing resin having a thick coating on the light attenuation layer 6,
This ultraviolet ray is irradiated to the above-mentioned ultraviolet curable resin to cure the resin.
To obtain a transparent layer. Another method is to bond on the light attenuation layer 6.
Apply a thin coating of the adhesive 7, and place a transparent cover sheet on the adhesive 7.
And put on it. Transparent layer 9 in this case
Consists of an adhesive 7 and a cover sheet 8. The cover sheet 8 is made of polycarbonate,
Plastic substrates such as polyolefin and acrylic, and glass
Substrate is used. The surface of the cover sheet 8 is a mirror surface.
No pits or grooves are formed. The thickness of the cover sheet 8 is the same as that of the substrate 1 described above.
High NA objective to increase the recording density
When a lens is used, 0.05 mm to 0.3 mm
A light-transmitting thin substrate is used. The thickness of the transparent layer 9 formed by these methods
Uses a laser with a wavelength of 400 nm to 420 nm to
When the numerical aperture (NA) of the objective lens of the head is 0.85
In this case, the thickness is preferably 70 μm to 120 μm. this
If it is out of the range, spherical aberration will occur and the recording density will be high.
This is because it becomes impossible to form a crack. The light attenuation layer 6 is not provided and only the transparent layer 9 is used.
To obtain a desired transmittance (95% to 50%), at present,
Is difficult for various reasons. That is, the adhesive layer 7
The cover sheet 8 is originally made of a transparent material.
In the vicinity of the wavelength of 400 nm to 420 nm, these are composed.
The absorption of the molecule itself is extremely small,
As a result, it is difficult to lower the transmittance. Therefore, only the transparent layer 9 is used as described above.
To obtain the desired transmittance (95% to 50%), a transparent layer
A material that absorbs light into the sheet 8 and the adhesive layer 7 that constitute the component 9
Material, ie, the need to add damping material. However, in such a case, the adhesive
The UV light for curing is not transmitted, so the adhesive hardens
The possibility of disappearing comes out. That is, if the adhesive layer 7
When an attenuation material is added to the cover sheet 8 and
UV light cannot penetrate through these layers
As a result, the curing reaction cannot be induced and the adhesive
I can't harden. In other words, a damping property
It is difficult to cure. In this embodiment, as described above, the guide groove
Alternatively, on the substrate 1 on which the pits are formed,
Emissive layer 2, first protective layer 3, phase change recording layer 4, second protective layer
5. a phase-change optical information recording medium 10 provided with a transparent layer 9;
Accordingly, light is reduced between the second protective layer 5 and the transparent layer 9.
By providing the decay layer 6, a unique effect as described later is provided.
Was played. As a method of applying the above-mentioned ultraviolet curable resin,
Are spin coating, spraying, dipping,
Do coating method, roll coating method, screen printing method, etc. are used
You can. This ultraviolet curable resin is at least
Limmer, monofunctional acrylate monomer, polyfunctional acryle
And a photopolymerization initiator. The light incident surface on the transparent layer 9 may be hard
DOCOAT and an antistatic agent can also be provided. Further, it has two recording layers, and records from one side.
Create multi-layer media for playback and double-sided type (double-sided disc)
It can also be made. Laser light is applied to the optical disk thus manufactured.
And a flash lamp or the like to irradiate the phase-change recording layer 4
Heating is performed at a temperature higher than the crystallization temperature to perform an initialization process. Practically
The laser beam applied to the optical disc 10
Beam diameter larger than the
In the same direction while rotating the disc.
Initialize sometimes. <Example 1> Track pitch 0.32μ
m, pre-groove with a groove depth of 18 nm (groove width 0.1
(Thickness: 3 μm, land width: 0.19 μm)
On a 1 mm polycarbonate substrate 1, a reflective layer 2 and a first
Protective layer 3, phase change type recording layer 4, second protective layer 5, light attenuating layer
6 were sequentially formed into a laminated film. Hereinafter, a film forming procedure will be described. First, figure
The degree of vacuum in the vacuum chamber not shown is 1 × 10^-6Tor
After evacuating to a pressure of 2 mTorr or less, the atmosphere is
A laminated film was formed in an atmosphere. When forming the laminated film,
First, Ag98 (at%) Pd1 (at
%) Cu1 (at%) at a film formation rate of 2.0 nm / s.
The film was formed with a thickness of 0 nm. Next, ZnS—SiO 2 is formed on the reflective layer 2._Two
(80: 20mol%) RF (high frequency) sputtering
To form a first protective layer 3 having a thickness of 10 nm. this
In this case, the film forming speed is 0.08 nm / s. Next, phase change recording is performed on the first protective layer 3.
Ge 8 (at%) Sb 71 (at%) Te 2 as layer 4
1 (at%) is formed to a thickness of 15 nm by a DC sputtering method.
Was. Then, on the phase change recording layer 4, the second protective layer
ZnS-SiO as protective layer 5_Two(80:20 mol%)
A film was formed to a thickness of 43 nm by an RF sputtering method. This
In this case, the film formation rate is 0.2 nm / s. Finally, the light attenuation layer 6 is formed on the second protective layer 5.
Au is 10 nm thick by DC sputtering
Was formed. The deposition rate in this case is 0.1 nm / s.
You. The transmittance for a wavelength of 405 nm was 50%. The disk was removed from the vacuum chamber
Then, an ultraviolet-cured resin is used as the adhesive layer 7 constituting the transparent layer 9.
Fat (Sumitomo Chemical XR98) spin-coated on the light attenuation layer 6
And a 90 μm thick polycarbonate
Place the cover sheet 8 and violet through this cover sheet 8
The phase change is achieved by irradiating the outside line and curing and bonding the two.
An optical disk 10 was obtained. The thickness of the transparent layer 9 in this case
Was 100 μm. Next, the phase change type optical disk 10 (hereinafter referred to as
The recording / reproducing characteristics of the optical disk were referred to below. Ma
First, while rotating the optical disk 10, from the transparent layer 9 side
Amorphous phase change recording layer 4 by laser light irradiation
From phase to crystalline state with high reflectivity
Was. Next, the groove portion of the phase-change recording layer 4 from the transparent layer 9 side.
Was recorded. The groove is in the direction of incidence of the laser beam
It looks convex. The recording conditions were a recording laser (Nichia
The wavelength is 405 nm and the NA of the objective lens is 0.85
Describes a 1-7 pp modulation signal with a mark length of 0.154 μm.
Recorded. The linear velocity in this case was 5 m / s. The recording strategy uses a multi-pulse,
Head pulse is 0.3T (1T is recording cycle), multi-pulse
Was set to 0.3T, and the cooling pulse was set to 0.7T. Shortest
2T, which is a peak, has one leading pulse, one multipulse,
And one cooling pulse. 7.0m peak power
W and the bias power was set to 3.5 mW. The laser light is changed at a bottom power of 0.1 mW.
Recording, adjust the playback light power and perform playback.
Measure C / N of 2T signal using vector analyzer
Was. As a result, the optical disk without the optical attenuation layer 6 is provided.
In C10, the reproduction power is 0.3 mW and the C / N is 50.2
dB, but the disc provided with the light attenuation layer 6
Since the raw power is attenuated by the light attenuation layer 6, the reproduced light causes
The erasure of the phase change recording mark is suppressed by the light attenuation layer 6.
The playback power could be increased more than when there was no playback. In the optical disk provided with the light attenuation layer 6, the reproduction
When the power is 0.5mW, C / N shows 52.5dB.
Was. Laser power and laser noise improve C / N
Laser noise is reflected in the laser power.
This is due to the inverse relationship. In other words, the playback
Increasing the power reduces laser noise. However,
Laser noise has a minimum value, beyond which the laser power
However, increasing the laser noise will increase the laser noise.
U. <Embodiment 2> As the light attenuating layer 6, Ag98
7 nm of (at%) Pd1 (at%) Cu1 (at%)
In the same manner as in Example 1 except that a thin film of
A disk 10 was prepared and recorded. The film formation method is DC spa
It is tatta. The transmittance for a wavelength of 405 nm is 7
It was 0%. As a result, the optical disk without the optical attenuation layer 6 is provided.
In C10, the reproduction power is 0.3 mW and the C / N is 50.2
dB, but the disc provided with the light attenuation layer 6
Playback power than when no
Was. In the optical disk 10 provided with the light attenuation layer 6, the reproduction power
At the time of -0.5 mW, C / N indicates 52.7 dB, and C / N
N increased. <Embodiment 3> Ge35 is used as the light attenuation layer 6.
(At%) N65 (at%)
Outside, the optical disk 10 is mounted in the same manner as in the first and second embodiments.
Fabricated and recorded. The deposition method is reactive DC sputtering
Ge target in argon and nitrogen gas using ring
The film was formed while reacting with. Transmission for wavelength 405 nm
The excess rate was 95%. As described above, the light without the light attenuation layer 6
In the disk 10, the reproducing power is 0.3 mW and the C / N is 5
0.2 dB, but with a disc provided with a light attenuation layer 6
Means that the reproducing power is higher than when the light attenuation layer 6 is not provided.
I was able to. In the optical disk 10 provided with the light attenuation layer 6,
Is a reproduction power of 0.35 mW, C / N is 51.5 dB
And C / N increased. As is clear from the above examples, the transmittance
Is determined by the sensitivity of the light attenuation layer 6.
I understand. In the above-described embodiment, the necessity of the light attenuation layer
Has been explained in various ways, but we will develop materials and other materials for the transparent layer
As a result, the transparent layer itself absorbs light, and
If it is possible to obtain an excess rate, the composition of the transparent layer itself
Only with this, the object of this embodiment can be achieved. [0074] As described in detail above, the present invention provides a guide groove
Or on a substrate with pits, at least
Layer, first protective layer, phase change recording layer, second protective layer, light attenuation
Layer and a transparent layer in this order.
A light attenuation layer between the second protective layer and the transparent layer.
Due to the provision, reproduction with a short wavelength blue-violet laser
Even when using a phase change material for the recording layer
Providing optical discs with high C / N ratio without reproduction deterioration
can do. The light attenuating layer is transparent to reproduction light.
By setting the excess rate to 95% to 50%,
Enables stable recording and reproduction by increasing the reproduction power margin
can do. As a result, the recording / reproducing operation margin
Can be expanded to provide a wide system design margin
it can.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view showing one embodiment of an optical disk according to the present invention. [Description of Signs] 1 Substrate 2 Reflective layer 3 Second protective layer 4 Phase change recording layer 5 First protective layer 6 Light attenuating layer 7 Adhesive layer 8 Cover layer (sheet) 9 Transparent layer 10 Phase change optical disk

   ────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Katsunori Oshima             3-12 Moriyacho, Kanagawa-ku, Yokohama-shi, Kanagawa             Local Victor Company of Japan F-term (reference) 5D029 HA04 MA03 MA04

Claims (1)

Claims: 1. A phase change type in which at least a reflection layer, a first protection layer, a phase change recording layer, a second protection layer, and a transparent layer are provided on a substrate on which guide grooves or pits are formed. An optical information recording medium, comprising: a light attenuation layer having a transmittance of 95% to 50% with respect to irradiation light provided between the second protective layer and the transparent layer. Optical information recording medium.