JP4313386B2 - Optical information recording medium and recording method for the medium - Google Patents

Description

  The present invention relates to an optical information recording medium and a recording method for the medium, and more specifically, optical recording is performed on a recording layer material by irradiating a light beam, information is recorded and reproduced, and rewriting is performed. The present invention relates to a possible phase change optical information recording medium and a recording method for the medium.

  As one of optical information recording media capable of recording, reproducing, and erasing information by laser beam irradiation, a so-called phase change optical information recording medium using a transition between a crystal and an amorphous phase or between a crystal and a crystal phase is known. Yes. This can be overwritten by a single beam and is simpler than the optical system on the drive side, and is applied as a computer-related, video, and sound recording medium.

  As the recording material, GeTe, GeTeSe, GeTeS, GeSeS, GeSeSb, GeAsSe, InTe, SeTe, SeAs, Ge-Te- (Sn, Au, Pd), GeTeSeSb, GeTeSb, Ag-In-Sb-Te, etc. are used. It has been. Among these, in particular, Ag—In—Sb—Te has a high sensitivity and a characteristic that the outline of the amorphous portion is clear. Compared with the conventional one, C / N, erasure ratio, sensitivity, recording. JP-A-8-22644 discloses a composition as an optical information recording medium that can achieve a dramatic improvement in erasure repeatability.

The constituent elements of this recording layer are mainly Ag, In, Sb, and Te, and the respective composition ratios α, β, γ, and δ (atomic%) have the following relationship.
0 <α ≦ 30
0 <β ≦ 30
10 ≦ γ ≦ 50
10 ≦ δ ≦ 80
α + β + γ + δ = 100

In particular, a recording method for recording and erasing in a region where the rotational linear velocity of the disk is from 1.2 m / s to 5.6 m / s as applied to a rewritable compact disk (CD) using this material system As the optimum optical information recording medium, the constituent elements of the recording layer of the medium are mainly Ag, In, Te, and Sb, and the respective composition ratios α, β, γ, and δ (atomic%) are expressed by the following formulas: An optical information recording medium having the following relationship is disclosed in Japanese Patent Laid-Open No. 9-263055.
1 ≦ α <6
7 ≦ β ≦ 20
20 ≦ γ ≦ 35
35 ≦ δ ≦ 70
α + β + γ + δ = 100

  In the current optical disc, a 4.7 GB capacity DVD-ROM has already been commercialized, and a high recording density medium such as DVD-RW has been proposed as an optical information recording medium having the same capacity and high compatibility. Since the rotational speed of the DVD-ROM disc is 3.49 m / s, the recording material used for the optical information recording medium having the same speed as this can be used even with the composition disclosed in Japanese Patent Laid-Open No. 9-263055. Is possible. However, it has been found through experiments that it is difficult to realize a recording medium that is capable of high-density recording having the same capacity as that of a DVD-ROM and that is compatible with a recording linear velocity of twice or more (about 7 m / s or more).

  The present invention provides a rewritable optical information recording medium having the same capacity as a DVD-ROM, having good recording characteristics during high linear velocity recording, and excellent storage stability. An object of the present invention is to provide a recording method for this medium.

  In order to solve the above-mentioned problems, the inventors focused attention on the composition of the recording layer, the constituent metal of the metal reflection layer, and the dielectric layer, and as a result of intensive studies, the present invention has been completed.

That is, according to the present invention, first, a first dielectric layer, a phase change recording layer, a second dielectric layer, and a metal reflective layer are formed on a transparent substrate in that order by sputtering. the material of the second dielectric layer was a mixture of ZnS and SiO _2, the composition of the phase change recording layer material an optical information recording medium with _{Ag a in b Sb c Te d} , the composition Ag _a an in _b An element X _e other than the composition component is added to Sb _c Te _d , and the metal reflective layer is made of Ag or an Ag alloy, and other than sulfide is interposed between the second dielectric layer and the metal reflective layer. An optical information recording medium comprising a third dielectric layer made of a material (where a, b, c and d are in the relationship of the following formulas (1) to (4) and c / When cd with (c + d) being r, it is assumed that the following equation (5) is satisfied]:
0 <a ≦ 0.01 (1)
0.03 ≦ b ≦ 0.10 (2)
0.40 ≦ d ≦ 0.70 (3)
a + b + c + d = 1 (4)
0.60 ≦ r ≦ 0.85 (5)

The first invention includes an optical information recording medium in which the element Xe is Ge (provided that the addition amount e is in the relationship of the following formula (6)).
0.005 ≦ e ≦ 0.07 (6)

In the first invention, the thickness ratio of the second dielectric layer to the first dielectric layer (R1 = second dielectric layer thickness / first dielectric layer thickness) is expressed by the following formula ( The optical information recording medium in the relationship 7) is included.
0.1 ≦ R1 ≦ 0.5 (7)

  Furthermore, the first invention includes an optical information recording medium in which the thermal conductivity of the third dielectric layer is larger than the thermal conductivity of the second dielectric layer.

In the first invention, the thickness ratio of the third dielectric layer to the second dielectric layer (R2 = third dielectric layer thickness / second dielectric layer thickness) is expressed by the following formula ( The optical information recording medium in the relationship 8) is included.
0.1 ≦ R2 ≦ 0.5 (8)

  The first invention further includes an optical information recording medium in which the material of the third dielectric layer is metal carbide or a mixture of metal carbide and metal oxide or metal nitride, and the metal of the metal carbide is Si. And an optical information recording medium in which the metal oxide or metal nitride metal is Si, Ti or Al.

  According to the present invention, secondly, in recording optical information on any one of the optical information recording media described above, the laser light emission waveform is a recording pulse train composed of a plurality of on-pulses and subsequent off-pulses, Recording method for an optical information recording medium that continuously changes the recording frequency corresponding to the recording radius position from the outer circumference to the outer circumference or from the outer circumference to the inner circumference, and fixes the widths of the plurality of on pulses at the same time constant. There is provided a recording method for an optical information recording medium, in which a portion to be multiplied and a portion for multiplying a window width by a constant are continuously combined.

  According to the second aspect of the present invention, information is recorded on the optical information recording medium by changing the length of a recording mark that forms an amorphous portion generated by irradiating LD in the crystal of the recording layer. The length of the mark is controlled by the number of recording pulse trains (n + 1) (where n is an integer from 1 to 13), and each of the recording pulse trains from 2 pulse trains to 14 pulse trains. Includes a recording method for an optical information recording medium in which the n + 1 falling pulse position X is used at random at the same recording linear velocity and always falls at the same position within the reference clock width. It is.

  Further, in the second invention, only when n = 1 in the pulse train of n = 1-13, other n = 2 in the reference clock width than other n = 2-13. A recording method for an optical information recording medium that falls with a time constant earlier than −13 is included.

  According to the present invention, it is a rewritable optical information recording medium having the same capacity as a DVD-ROM, has good recording characteristics at the time of high linear velocity recording, in particular, good characteristics regarding the modulation degree, and storage stability. In particular, an optical information recording medium having an improved overwrite archival life and a recording method for the medium are provided, and the contribution to the optical information recording field is extremely large.

In general, rewritable optical discs compatible with high-density recording include those using a recording material near the compound composition of Ge ₂ Sb ₂ Te ₅ and those using a recording material mainly composed of a composition represented by AgInSbTe. However, the latter material is used for CD-RWs that have already been commercialized and are widely used due to their compatibility with high-density recording and good erasing characteristics during overwriting. The composition of the AgInSbTe recording material is disclosed in, for example, Japanese Patent Application Laid-Open Nos. 8-22644 and 8-263871. Furthermore, recently, a medium DVD-RW capable of high-density rewriting recording of 4.7 GB has been commercialized for video applications.

  This rewritable optical disc has the same capacity as a DVD-ROM for which many products are already available, and is capable of constant-speed recording. The AgInSbTe recording material has characteristics that can be adapted for its use. ing. However, in the future, it is expected to develop an optical disc capable of high linear velocity recording for the purpose of recording in a short time in this application.

  As a composition capable of high linear velocity recording of an AgInSbTe recording material, the present applicant has proposed a composition with a reduced Ag content (Japanese Patent Application No. 11-153316). Even with this recording material, for example, DVD-ROM recording from 1 × to 2.5 × speed was possible. However, particularly when recording at 2.5 × speed or higher, for example, good performance between different drives. It has been found that the allowable value of the writing power for obtaining a good recording characteristic, the overwrite characteristic or the storage characteristic at the time of overwriting is not sufficient.

  As a result of repeated studies to solve these problems, it has been confirmed through experiments that the storage reliability can be solved by adding Ge to the recording layer proposed by the applicant. Japanese Patent Laid-Open No. 8-263871 describes that the storage reliability can be improved by adding Ge to AgInSbTe. For example, in the recording linear velocity region corresponding to 2.5 times the speed of DVD-ROM, It was also confirmed by experiments that the addition amount of Sb is small and that the addition of Ge also has the disadvantage of lowering the degree of modulation of the disk.

In order to solve this, it can be solved by making the reflective layer Ag or an Ag alloy. Furthermore, when Ag or an Ag alloy is used for the reflective layer, the conventional ZnS-SiO ₂ upper protective layer is directly formed of Ag or Ag. In contact with the Ag alloy, good recording characteristics cannot be obtained due to the sulfurization of Ag. In order to prevent this, between the ZnS-SiO ₂ and the reflective layer, Si carbide or nitride and these or these and It was also confirmed that a mixture of oxide dielectrics was effective.

  Therefore, in this way, the allowable value of write power for obtaining good recording characteristics between different drives and the overwrite characteristics are improved. Also, when designing a drive for the purpose of low power consumption, a CAV method is employed in which recording is performed with a constant motor rotation speed. In this case, assuming that the inner circumference is 1, the recording medium is the same as the CD-RW. At the outermost peripheral portion of the disk having a diameter of 120 mm, the linear velocity is 2.5 times. In order to realize a recording medium corresponding to a linear velocity of 1 to 2.5 times, the above-described medium structure gives a good result. Further, by devising a recording strategy, the recording characteristics are improved. Can be achieved. In particular, in order to flatten the recording characteristics at a linear velocity of 1 to 2.5 times, it is important to adjust the recording strategy.

  The applicant of the present application has proposed an effective strategy for recording in CAV for an SbTe + M recording medium having a four-layer structure using an Al reflective film (Japanese Patent Application No. 11-31926). The effectiveness was confirmed, and further effective improvements were added.

Therefore, according to the present invention, first, a first dielectric layer, a phase change recording layer, a second dielectric layer, and a metal reflective layer are formed on a transparent substrate in that order, and the first and second dielectric layers are formed in that order. An optical information recording medium in which the material of the body layer is a mixture of ZnS and SiO ₂ and the composition of the material of the phase change recording layer is Ag _a In _b Sb _c Te _d , the composition Ag _a In _b Sb _c Te An element X _e other than the composition component is added to _d , and the metal reflective layer is made of Ag or an Ag alloy, and is made of a material other than sulfide between the second dielectric layer and the metal reflective layer. An optical information recording medium comprising a third dielectric layer (where a, b, c and d are in the relationship of the following formulas (1) to (4) and c / (c + d) When r is r, it is assumed that the following equation (5) is satisfied].
0 <a ≦ 0.01 (1)
0.03 ≦ b ≦ 0.10 (2)
0.40 ≦ d ≦ 0.70 (3)
a + b + c + d = 1 (4)
0.60 ≦ r ≦ 0.85 (5)

  When the composition of the recording layer material is in the relationship of the above formulas (1) to (4) and (5), when (1) exceeds this range, the optical recording medium used for CAV recording is particularly high in linear velocity. At the recording speed on the side, basic characteristics such as jitter, reflectance, and modulation degree are deteriorated. When not added at all, storage stability deteriorates. If (2) exceeds this range, the amorphous mark is crystallized by the reading light of the drive, which increases the risk of damaging the shape of the optical recording medium mark. As a result, reproduction jitter is deteriorated. When (3) exceeds this range, the optical information recording medium used for CAV recording, as in (1), is fundamental in terms of jitter, reflectance, modulation degree, etc., particularly at high linear velocity recording speeds. In the case where the deterioration of characteristics is caused and the amount is small, storage stability is deteriorated, which is not preferable.

The element Xe is preferably Ge. [However, it is assumed that the addition amount e is in the relationship of the following formula (6)].
0.005 ≦ e ≦ 0.07 (6)
If this addition amount is too large in the above formula (6), the basic characteristics such as jitter, reflectivity, and modulation degree are deteriorated at the recording speed on the high linear velocity side. This is undesirable because it causes the problem of poor stability.

The film thickness ratio of the second dielectric layer to the first dielectric layer (R1 = second dielectric layer film thickness / first dielectric layer film thickness) is preferably in the relationship of the following formula (7). .
0.1 ≦ R1 ≦ 0.5 (7)

  In the optical information recording medium of the present invention, it is preferable that the thermal conductivity of the third dielectric layer is larger than the thermal conductivity of the second dielectric layer. Since the relationship between the film thickness and the thermal conductivity of the third dielectric layer is larger than that of the second dielectric layer, the heat generated by absorbing the LD light in the recording layer is efficient. This is because a stable amorphous mark can be obtained even at the time of high linear velocity recording by being often radiated to the reflective heat radiation layer.

Furthermore, the film thickness ratio of the third dielectric layer to the second dielectric layer (R2 = third dielectric layer film thickness / second dielectric layer film thickness) may have the relationship of the following formula (8). preferable.
0.1 ≦ R2 ≦ 0.5 (8)

  Further, the material of the third dielectric layer is a metal carbide or a mixture of a metal carbide and a metal oxide or metal nitride, the metal of the metal carbide is Si, and the metal of the metal oxide or metal nitride Is preferably Si, Ti or Al. Because the metal of the metal carbide is Si, and the metal of the metal oxide or metal nitride is Si or Al, the thermal conductivity relationship and the film uniformity are favorable. is there.

  Secondly, in recording the optical information on the optical information recording medium according to the present invention, the light emission waveform of the laser beam is a recording pulse train composed of a plurality of on-pulses followed by off-pulses, from the inner periphery to the outer periphery or from the outer periphery to the inner periphery. A recording method for an optical information recording medium for recording by continuously changing a recording frequency corresponding to a recording radius position, wherein a constant is set for a window width and a portion for fixing the plurality of on-pulse widths to the same time constant. There is provided a recording method for an optical information recording medium, characterized by continuously combining a multiplying portion.

In this recording method, as shown in FIG. 2, at the time of recording at the same linear velocity, the falling position of each pulse train is the same position in the reference clock in each (n + 1) × T _w reference clock. By adjusting the pulse width, good jitter characteristics can be obtained. However, n is an integer of 1-13. This width is preferably in the range of 0.2 to 0.8 of the width of each reference clock. If it exceeds the range represented by the above formula, the off-pulse part becomes too short, and sufficient cooling time is reduced, so a stable amorphous mark cannot be obtained. This is because it is too narrow to obtain a sufficient amount of heat for obtaining an amorphous mark.

  Further, in the recording method of the present invention, only the falling position of the n = 1 (first pulse) is used with a falling time constant earlier than n = 2-13. Furthermore, jitter characteristics can be reduced. In this case, when the falling position of n = 1 (first pulse) with respect to the rear end of each pulse train of 2 ≦ n ≦ 13 is set to 0.01T to 0.3T from the rear end position of each pulse train of 2 ≦ n ≦ 13 Is preferred. This is because, by fixing the time constant in this way, in the amorphous mark having a length of n = 1 to 13, variation in the overall length of each mark can be suppressed small with respect to each reference clock.

  Hereinafter, the present invention will be specifically described. FIG. 1 is a schematic view of an optical recording medium structure of the present invention. The optical information recording medium of the present invention comprises a first dielectric layer 2 as a lower protective layer, a phase change recording layer 3 and a second dielectric layer 4 as an upper protective layer on a polycarbonate substrate 1 having guide grooves by sputtering. The third substrate layer and the metal reflective layer 6 are formed, and the opposite substrate that adheres to the opposite substrate may or may not be laminated with each layer functioning as a medium. For the adhesive layer, an adhesive sheet, a radical ultraviolet curable resin, a cationic polymerization resin, or the like can be used. Further, an environmental protection layer 7 made of an ultraviolet curable resin applied by spin coating may be laminated on the metal reflective layer.

  The film formation conditions of each layer are as follows: the first and second dielectric layers have an input power of 3 kW and an Ar gas pressure (film formation chamber pressure) of 2 mTorr; the phase change recording is an input power of 1 kW and an Ar gas pressure (film formation chamber). Atmospheric pressure) 2 mTorr, the third dielectric layer had an input power of 1 kW, Ar gas pressure (film forming chamber pressure) 2 mTorr, and the metal reflection layer had an input power of 9 kW and Ar gas pressure (film forming chamber pressure) 2 mTorr. The first and second dielectric layers can be formed by various vapor deposition methods such as vacuum deposition, sputtering, and electron beam deposition.

  The material of each layer is as follows. As the phase change recording layer, a layer obtained by adding Ge to conventional AgInSbTe is used. In order to obtain a higher linear velocity optical disc, the Ag content is preferably 1% or less in terms of atomic ratio. Further, Ge is used as an element added for improving storage stability. In addition to Ge, good results can be obtained as long as it is an element that lowers the crystallization speed and simultaneously raises the crystallization temperature with respect to AgInSbTe, and Ga, Si, N, etc. bring about the same effect. . However, for a high linear velocity optical disk, this content needs to be suppressed to 7% or less, and it is particularly desirable to add 5% or less.

For the first and second dielectric layers, the same mixed target of ZnS (80%) and SiO ₂ (20%) as in the conventional example is used. This mixing ratio may be adjusted to adjust the thermal conductivity, but the mixing ratio of SiO ₂ is desirably in a range not exceeding 50%.

The third dielectric layer uses a mixture of SiC and SiO ₂ , but may be any dielectric material having a higher thermal conductivity than the first and second dielectric layers and whose main component is other than oxide. The content of the oxide is preferably 20% or less by weight basis ratio.

  The material used for the metal reflective layer is an element such as Pd, In, Cu, Si, Ge or a mixture thereof with respect to Ag or Ag, or a metal that is eutectic with a content of up to 10% with respect to Ag. The film thickness is preferably 60 to 200 nm. If it is less than 60 nm, the heat dissipation effect cannot be obtained. Moreover, since it will become easy to produce interface peeling when a film layer is too thick, it is unpreferable.

The film thickness ratio R1 = (second dielectric / first dielectric) between the first dielectric layer and the second dielectric layer is:
0.1 ≦ R1 ≦ 0.5
It is preferable that When the first dielectric layer is too thin, the heat absorbed by the recording layer is trapped on the substrate side during recording with laser light, which is not preferable.

The third dielectric layer preferably has a higher thermal conductivity than the second dielectric layer, and the thickness ratio R2 = (third dielectric / second dielectric) is preferably in the following range. .
0.1 ≦ R2 ≦ 0.5
If the third dielectric layer is too thick, the heat absorbed by the recording layer during recording with laser light is dissipated, and the temperature rise of the recording layer becomes insufficient, resulting in a decrease in recording sensitivity.

  Thus, by optimizing the film thicknesses of the first, second, and third dielectric layers, for example, high linear velocity recording at 2.5 times or higher speed of DVD-ROM becomes possible, and further, overwrite characteristics are achieved. Therefore, an optical disc with good quality can be realized.

  Information is recorded on the optical information recording medium by changing the length of a recording mark (forms an amorphous portion generated by irradiating LD in the crystal of the recording layer). The length of the recording mark is controlled by the number of recording pulse trains (n + 1) described in claim 8, wherein n is an integer of 1-13. As a result, the recording strategy shown in FIG. 2 is obtained, but only the first pulse forms a pulse using 2T of the clock, and in the other cases, one pulse rises and rises with respect to the clock of 1T. Go down. By using this recording strategy, a recording mark having a length of 3 to 14 times the reference clock width Tw can be formed. A method of performing mark length modulation using a length of 3 to 14 times the clock width Tw is called an EFM + modulation method, and is a known recording modulation method.

  Further, the falling pulse position X of each recording pulse train (n + 1, that is, 2 to 14 pulse trains are used randomly) according to claim 8 is recorded at the same recording linear velocity (same Tw). In this case, the length changes from a 3 × T length mark to a 14 × T length mark in a relatively linear manner by always falling at the same position within each reference clock width. Such a recording method can be realized. As a result, recording with good jitter characteristics can be performed, but in the present invention, only the trailing edge of the leading pulse is made shorter than the trailing edge of the other pulse trains, so that the mark length of 3T-14T can be reduced. The linearity can be further improved.

  FIG. 2 is a timing chart showing the pulse arrangement of the recording strategy. The strategy defined in the present invention is basically the same strategy as shown in Japanese Patent Application No. 11-131926 proposed by the applicant, but also for the recording medium of the present invention, by using this strategy, It has been found that flat jitter characteristics can be obtained at a linear velocity of DVD-ROM from X1.0 to X2.5.

  Furthermore, as a result of experimenting on the optimum conditions of the strategy, it was found that it is effective to move only the first pulse of the pulse train earlier than other subsequent pulses in time series. This is shown in FIG.

  Table 1 shows the number of repeated recordings at a recording linear velocity of 8.5 m / s of the optical recording medium of the present invention together with a comparative example. The number of repeated recordings is determined by the maximum number of times that the jitter value σ / Tw normalized by the window width Tw satisfies the standard value. The track pitch is 0.74 μm.

  Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1
The recording layer having the composition shown in Table 1 is 20 nm, the first dielectric layer using a ZnSSiO ₂ mixed target is 70 nm, the second dielectric layer is 15 nm, and the third dielectric layer using a SiCSiO ₂ mixed target is 5 nm. Recording is performed on an optical information recording medium formed by sputtering on a polycarbonate substrate with a metal reflective layer using an Ag—Pd alloy target having a thickness of 140 nm, using the recording strategy described in claims 8 and 9, and recording characteristics thereof And storage stability was evaluated. The storage stability was judged by the storage time exceeding the reference value under the conditions that the jitter characteristic was 85 ° C. and 85% RH.

Example 2
Except for changing the composition of the recording layer, the procedure was the same as in Examples.

Example 3
The recording layer composition of Example 1 was recorded using the recording strategy shown in claim 10.

Example 4
Recording was performed on the same recording layer composition as in Example 2 using the recording strategy shown in claim 10. The conditions and results in Examples 1 to 4 are shown in Table 1.

Example 5
FIG. 3 shows the results of CAV recording performed on the recording layer composition of Example 1 using the recording strategies shown in claims 8 and 9 and the recording strategy shown in claim 10. As a comparative example, the result of performing CAV recording using a strategy in which the portion fixed by the same time constant and the portion fixed by the same time constant are removed from the portion fixed by the same time constant described in claim 8 and the portion multiplied by the constant by the window width Tw. Show at the same time. By using the recording strategy shown in claims 8 and 9, a relatively flat jitter characteristic can be obtained from the inner periphery to the outer periphery. Further, by using the recording strategy shown in claim 10, the jitter characteristic can be improved. I found out. It has been found that when CAV recording is performed using a strategy in which the fixed portion with the same time constant is eliminated, the jitter rises on the low linear velocity side. This is presumably because the low linear velocity side pulse becomes too narrow in the strategy without the fixed part with the same time constant.

Comparative Example 1
The recording characteristics and storage stability were evaluated with the recording layer composition of Example 1 being AgInSbTe alone.

Comparative Example 2
The recording characteristics and storage stability were evaluated in the same manner as in Example 1 except that the reflective layer material was changed from an Ag alloy to an Al—Ti alloy in the layer configuration of the recording medium of Example 1.

Comparative Example 3
With respect to the recording layer composition of Example 1, recording was performed using a strategy in which the number of recording pulse trains was one less than the recording strategies shown in claims 8 and 9. The entire length of the pulse train was adjusted to be the same as the recording strategy described in claims 8 and 9. The recording linear velocity corresponding to the DVD-ROM 1 × speed has substantially the same recording characteristics as the recording strategies described in claims 8 and 9, but the recording characteristics at the recording linear velocity corresponding to the 2.5 × speed are poor. It was. The conditions and results in Comparative Examples 1 to 3 are shown in Table 1.

It is sectional drawing of the optical information recording medium of this invention. It is the figure which showed the pulse arrangement | sequence of the recording strategy with the timing chart. It is a figure which shows the mode of a recording strategy.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate 2 First dielectric layer 3 Recording layer 4 Second dielectric layer 5 Third dielectric layer 6 Metal reflective layer 7 Environmental protection layer

Claims (1)

A first dielectric layer, a phase change recording layer, a second dielectric layer, and a metal reflection layer are formed on a transparent substrate in that order by sputtering, and the materials of the first and second dielectric layers are ZnS and SiO _2. a mixture of the composition of the material of the phase-change recording layer an optical information recording medium with _{Ag a in b Sb c Te d} , to the composition _{Ag a in b Sb c Te d} , except said set forming component An optical element in which the element Xe is added, the metal reflective layer is made of Ag or an Ag alloy, and a third dielectric layer made of a material other than sulfide is provided between the second dielectric layer and the metal reflective layer. Information recording medium [where a, b, c, d are in the relationship of the following formulas (1) to (4), and when c / (c + d) is r, the relationship is in the following formula (5). When recording optical information, the laser light emission waveform is divided into multiple on-pulses followed by off-states. A recording method for an optical information recording medium, in which a recording pulse train is composed of pulses and the recording frequency is continuously changed from the inner circumference to the outer circumference or from the outer circumference to the inner circumference in accordance with the recording radial position, The part that fixes the width of all with the same time constant and the part that multiplies the constant by the window width are combined continuously ,
Recording of information on the optical information recording medium is performed by changing the length of a recording mark that forms an amorphous portion generated by irradiating LD in the crystal of the recording layer, and the length of the recording mark is It is controlled by the number of recording pulse trains (n + 1) (where n is an integer from 1 to 13), and each recording pulse train from 2 pulse trains to 14 pulse trains is randomly used n + 1 The falling pulse position X falls at the same position when n = 2-13 in the pulse train of n = 1-13 in each reference clock width when recording at the same recording linear velocity. A method for recording on an optical information recording medium, characterized in that, only when n = 1, it falls with a time constant faster than other n = 2-13 .
0 <a ≦ 0.01 (1)
0.03 ≦ b ≦ 0.10 (2)
0.40 ≦ d ≦ 0.70 (3)
a + b + c + d = 1 (4)
0.60 ≦ r ≦ 0.85 (5)