JP3816658B2 - Optical information recording medium and manufacturing method thereof - Google Patents

Description

【００４８】
また、拡散防止層８をＧｅＮ、拡散防止層７をＧｅＮｉＮ、ＧｅＬａＮとし、拡散防止層８を成膜する際のスパッタガス中の窒素分圧を３０vol.％で一定、拡散防止層７を成膜する際のスパッタガス中の窒素分圧を４０vol.％、５０vol.％、６０vol.％と変化させた以外は（１）（２）と同条件で作製した媒体をそれぞれ（３）、（４）とする。この場合の比較例として拡散防止層７、８を共にＧｅＮとした場合の媒体を（０）’とする。これらの媒体を評価した結果を（表２）に示す。
【００４９】
【表２】

【００５０】
以上、（表１）及び（表２）の結果より、拡散防止層としてＧｅＮｉＮ、またはＧｅＬａＮを用いた場合、ＧｅＮのみの場合に比べて、記録の繰り返し特性を損ねることなく耐候性が向上していることがわかる。
【００５１】
次に、拡散防止層７、８をそれぞれＧｅＮ、ＧｅＮｉＮとし、ＧｅＬａＮ膜中に含まれるＣｒ原子数のＧｅ原子数に対する比率を５％、１０％、２０％、３０％、５０％、６０％と変化させたディスクを作製し、これらの媒体を順に（５）（６）（７）（８）（９）（１０）とする。ディスクの層構成は上記既述のディスク（０）〜（４）と同様とし、拡散防止層７を成膜する際の窒素分圧を４０vol.％で一定、拡散防止層８のそれをvol.２０％、３０vol.％、４０vol.％、５０vol.％、６０vol.％と変化させた。これらのディスクの評価結果を（表３）に示す。
【００５２】
【表３】

【００５３】
（表３）より、Ｎｉ含有量がＧｅに対して１０atom％以上になるとＮｉの添加効果が現われ始めることがわかる。但し、Ｃｒ含有量がＧｅに対して６０atom％以上となると記録の繰り返し特性が悪化する。これはＮｉがＧｅに比べ窒素と結合しにくく、窒素と結合しない余剰Ｃｒが膜中に過剰に存在し、これらの原子が記録膜へなだれ込んで記録の繰り返し特性が悪化しているためと考えられる。以上より、ＧｅＮｉＮ膜中のＮｉ含有量は、Ｇｅに対して５０％以下が好ましいといえる。
【００５４】
上記の説明では、Ｘ成分としてＮｉ及びＬａを例に説明したが、Ｘの元素はＮｉ及びＬａに限定されるものではなく、上述したように拡散防止層に含有されるＸは、情報の繰返しにともない仮に記録膜に拡散等しても、記録膜の光学特性に与える影響が少ない元素であれば良く、このような元素としてはＮｉ及びＬａ以外に、Ａｕ、またはＹなどの他のIIIａ族元素、またはＦｅ、Ｃｏなどの他のVIII族元素があり、その何れを用いても効果の差は若干見られるものの本質的には含有の効果があり、その含有量についてもほぼ同様であった。
【００５５】
【発明の効果】
以上述べたように、記録膜の少なくとも一方に接し、ＧｅＸＮ若しくはＧｅＸＯＮを主成分とする拡散防止層を、保護層と記録膜との間に設け、拡散防止層の材料成分Ｘを、Ｌａ、またはＮｉのうちの少なくとも１つの元素を含む材料とすることにより、耐候性に優れ、かつ情報信号の記録消去の繰り返し特性にも優れた光情報記録媒体を得ることが可能になる。
【図面の簡単な説明】
【図１】本発明の一実施例の光情報記録媒体の一層構成を示す断面図。
【図２】本発明の一実施例の(ＧｅＸ)・Ｏ・Ｎの組成範囲を示す三角組成図。
【図３】本発明の一実施例の成膜装置の一例を示す図。
【図４】従来の光情報記録媒体の層構成例を示す断面図で、Ａは４層構成の光記録媒体の断面図、Ｂは５層構成の光記録媒体の断面図。
【符号の説明】
１ 基板
２ 保護層
３ 記録膜
４ 保護層
５ 反射層
６ 保護層
７ 拡散防止層
８ 拡散防止層
９ 真空容器
１０ 基板
１１ 基板駆動装置
１２ ターゲット
１３ 陰極
１４ ガス供給口
１５ 排気口[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical recording information medium capable of recording information at high density and high speed using optical means such as laser beam irradiation and a method for manufacturing the same.
[0002]
[Prior art]
Magneto-optical recording media, phase-change recording media, and the like are known as media capable of recording information in a large capacity and capable of being reproduced and rewritten at high speed. These optical recording media utilize differences in optical properties of recording materials caused by local irradiation of laser light as recording. For example, in magneto-optical recording media, reflected light polarization caused by differences in magnetization state. The difference in the rotation angle of the surface is used as a record. In addition, the phase change type recording medium uses the fact that the amount of reflected light with respect to light of a specific wavelength differs between the crystalline state and the amorphous state, and the recording can be performed by modulating the output power of the laser. Since erasure and overwrite recording can be performed simultaneously, there is an advantage that information signals can be rewritten at high speed.
[0003]
Examples of the layer structure of the optical recording medium are shown in FIGS. 4A and 4B. The substrate 1 is made of a resin such as polycarbonate or polymethyl methacrylate (PMMA), or glass, and is generally provided with a guide groove for guiding a laser beam.
[0004]
The recording film 3 is made of a material that can change between different optical characteristics, and in the case of a rewritable phase change optical disc, Te—Sb—Ge, Te—Sn—Ge, Te—Sb—Ge—Se, Te. Materials whose main component is -Sn-Ge-Au, Ag-In-Sb-Te, In-Sb-Se, In-Te-Se, or the like are known.
[0005]
The reflective layer 5 is generally made of a metal such as Au, Al, Cr, or a metal alloy, and is provided for the purpose of heat dissipation and effective light absorption of the recording film, but is not an essential layer.
[0006]
Although omitted in FIG. 4, for the purpose of preventing the optical information recording medium from being oxidized or adhering to dust, a structure in which an overcoat layer is provided on the reflective layer 5 or an ultraviolet curable resin is used as an adhesive. A configuration in which a dummy substrate is bonded is generally used.
[0007]
The protective layers 2, 4, and 6 have a recording film protection function of preventing the recording film material from being oxidized, evaporated, and deformed, and by adjusting the film thickness, the absorptance, recording portion, and erasure of the optical recording medium are controlled. Since it is possible to adjust the difference in reflectance between the portions, it also has the function of adjusting the optical characteristics of the medium. In addition, the conditions of the material constituting the protective layer include not only satisfying the above-mentioned purpose but also good adhesion to the recording film constituent material or the substrate, and a film with good weather resistance in which the protective layer itself does not crack. It is essential to be.
[0008]
When these protective layers are used in contact with the recording film, they must be materials that do not impair the optical change of the recording material. For example, as shown in FIG. 4B, there are proposals for obtaining a medium having excellent adhesion to a substrate and a medium having excellent characteristics of repeated information recording by using two protective layers and different materials. It has been.
[0009]
Examples of the material for the protective layers 2, 4, and 6 include sulfides such as ZnS, oxides such as SiO ₂ , Ta ₂ O ₅ , and Al ₂ O ₃ , and nitrides such as GeN, Si ₃ N ₄ , and Al ₃ N ₄ . , GeON, SiON, oxynitride, other, carbides, dielectric fluoride such as AlON, or these appropriate combinations have been proposed, as a material that is exclusively applied ZnS-SiO ₂ Is mentioned.
[0010]
A technique for obtaining a good film quality by making the protective layer a composite material of different substances is known. For example, Japanese Patent Laid-Open No. 63-50931 has excellent adhesion to a substrate by adding at least one of aluminum oxide and silicon oxide to a composite dielectric of aluminum nitride and silicon nitride and limiting the refractive index thereof. An example of obtaining a protective layer having a good film quality is disclosed. Japanese Patent Laid-Open No. 2-105351 discloses an example in which a protective layer is a composite dielectric made of nitride of silicon and indium to obtain a film having good adhesion to the substrate and high ductility. . Further, Japanese Patent Laid-Open Nos. 2-265051 and 2-265052 disclose that the protective film is made of an element having a specific electric resistance smaller than that of Si, N, and Si, so that the film is hardly cracked and the recording film is protected. An example of obtaining an excellent protective layer is disclosed.
[0011]
[Problems to be solved by the invention]
It has recently been found that when recording rewriting is repeated many times, phenomena such as interdiffusion of constituent atoms and change with time in the composition of the recording film are observed between the recording film and the protective layer. This is because when the signal rewrite is repeated, the amplitude of the signal gradually decreases, and the jitter value of the mark position of the recording mark increases and the error rate of the recording signal increases. There is a problem that it is limited.
[0012]
However, in view of the ease of control of manufacturing conditions during production, a protective layer material having a wide margin for manufacturing conditions capable of obtaining good film quality is required. Needless to say, a medium that can be stored for a longer period of time is preferable.
[0013]
In order to solve the above-mentioned problems, an object of the present invention is to provide an optical information recording medium that is further excellent in weather resistance and has good recording erasure characteristics and repetition characteristics, and a method for producing the same.
[0014]
[Means for Solving the Problems]
In order to achieve the above object, an optical information recording medium of the present invention has a recording film whose optical characteristics reversibly change and which contains at least one element selected from Te, Se, and Sb as a main component, and the recording film An optical information recording medium having a diffusion prevention layer mainly comprising at least one selected from GeXN and GeXON and a protective layer containing sulfur or sulfide, which is in contact with at least one side of the diffusion prevention layer. Is provided between the protective layer and the recording film, and the material component X of the diffusion preventing layer contains at least one element selected from Ni and La . As a result, it is possible to obtain a medium having further excellent weather resistance as compared with the case where a layer mainly composed of GeN or GeON is provided.
[0017]
Further, the optical information recording medium has a diffusion prevention layer mainly composed of at least one selected from GeXN and GeXON in contact with both sides of the recording film, and the average content of the material component X of the diffusion prevention layer is It is preferable that the both sides of the recording film are different.
[0018]
Also In the optically recording medium has a diffusion preventing layer composed mainly of at least one selected from GeXN and GeXON in contact with both sides of the recording film, the diffusion barrier located on the laser incident side of the recording film Diffusion where the average composition of the layer is (Ge _{1 -y} X _y ) _a O _b N _c (where a> 0, b ≧ 0, c> 0, 0 ≦ y ≦ 1), opposite to the laser incident side The average composition of the prevention layer is (Ge _1-z X _z ) _d O _e N _f (where d> 0, e ≧ 0, f> 0, 0 ≦ z ≦ 1), and 0 ≦ y <z It is preferable to have a relationship.
[0019]
In the optical information recording medium, the average composition ratio of Ge and X contained in the diffusion prevention layer containing at least one selected from GeXN and GeXON as a main component is (Ge _1−y X _y ) _a O _b It is preferable to be within the range represented by N _c (where a> 0, b ≧ 0, c> 0, 0 <y ≦ 0.5).
[0020]
In the optical information recording medium, the average composition ratio of the diffusion prevention layer mainly composed of at least one selected from GeXN and GeXON is a ternary composition diagram in which (GeX), O, and N each have a vertex. , Composition point A ((GeX) _90.0 O _0.0 N _10.0 ), B ((GeX) _83.4 O _13.3 N _3.3 ),
C ((GeX) _35.0 O _0.0 N _65.0 ), D ((GeX) _31.1 O _55.1 N _13.8 ),
It is preferable to be within the range surrounded by.
[0021]
In the optical information recording medium, it is preferable that the thickness of the diffusion prevention layer containing at least one selected from GeXN and GeXON as a main component is 1 nm or more.
[0022]
Or in the optical information recording medium was, the recording film, Te, it is preferred that the phase change material mainly three elements Sb and Ge.
[0023]
The method of manufacturing an optical information recording medium of the present invention then, the optical properties are changed reversibly, a recording film mainly Te, Se, and at least one element selected from Sb, at least of the recording film contact on one side, a GeXN and the diffusion preventing layer composed mainly of at least one selected from GeXON, manufacturing method of the optical information recording medium having a protective layer containing sulfur or sulfide, the diffusion barrier A layer is provided between the protective layer and the recording film, and the diffusion prevention layer is made of Ge and X or a material containing any one of Ge, X, and N, and a rare gas and nitrogen are mixed. in a mixed gas formed by reactive sputtering comprising, material component X of the diffusion preventing layer, VIII group elements, look contains at least one element selected from IIIa group elements and Au, a material formed of the diffusion barrier layer The Group VIII element, characterized in that includes the Fe, Co, at least one element selected from Ni, III a group element material components of the diffusion barrier layer, containing at least one element selected from Y and La And
[0024]
As a result, a good film quality nitride layer or nitride oxide layer having further excellent adhesion to the recording material can be obtained.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings. An example of the layer structure of the optical information recording medium according to the present invention is shown in FIG. This is obtained by replacing the protective layers 6 and 4 with the diffusion preventing layers 7 and 8, respectively, in the configuration of FIG. 4B.
[0026]
The diffusion preventing layers 7 and 8 are provided mainly for the purpose of atomic diffusion between the recording film 3 and the protective layers 2 and 4, particularly when sulfur or sulfide is contained in the protective layer, preventing diffusion of these components. This layer may be provided on either or both sides of the recording film 3, but it is preferably provided on both sides in order to more effectively prevent diffusion between the recording film and the protective layer. In some cases, the components contained in the diffusion prevention layer may diffuse into the recording film after repeated recording of information. Even in such a case, a material that does not hinder the optical change of the recording film is prevented. What is necessary is just to use as a constituent material of a layer.
[0027]
The configuration of the optical information recording medium of the present invention is not limited to the above configuration, and a configuration in which a layer made of another material is provided between the diffusion preventing layer 8 and the reflective layer 5 and the protective layer 2 is all diffused. The present invention can be applied to various configurations such as a configuration in which the material of the prevention layer 7 is replaced, a configuration without a reflective layer, or a configuration with two reflective layers.
[0028]
In the following description, in order to simplify the description, the substrate 1 has a disk-shaped polycarbonate resin having a thickness of 0.6 mm and a diameter of 120 mm, and the dielectric layers 2 and 4 have 20 mol% of SiO ₂ in ZnS. An example in which the mixture, the recording film 3, a phase change material mainly composed of a Ge—Sb—Te alloy is used as the main component, and the Al alloy is used for the reflective layer 5 will be described. However, as the recording film material, for example, in addition to Ge—Sb—Te alloy, for example, Te—Sn—Ge, Te—Sb—Ge—Se, Te—Sn—Ge—Au, Ag—In—Sb—Te Various materials such as In-Sb-Se and In-Te-Se can be used, and other materials can be used for the material of the reflective layer 5 and the protective layers 2 and 4.
[0029]
Diffusion preventing layers 7 and 8 is a portion forming the feature of the present invention, as a main component one of GeXN or GeXON, X shall be the material containing at least one element of La or Ni.
[0030]
These diffusion prevention layers 7 and 8 are basically nitride or germanium nitride oxide on germanium, but have completely different properties from nitrides such as boron nitride, aluminum nitride and silicon nitride which have been proposed conventionally. Different. That is, these conventionally proposed nitrides have very poor adhesion to the recording film and / or the substrate due to internal stress or lubricity, and any of the constituent elements of the protective layer or the recording film. The effect which suppresses such movement is not seen at all. On the other hand, the germanium nitride or germanium nitride oxide of the present invention has an effect of suppressing the movement of elements and has good adhesion, and the present invention provides germanium nitride or germanium nitride oxide having such outstanding characteristics. Further, it is an invention capable of imparting further weather resistance and repeatability.
[0031]
In addition, the protective layer may contain rare gases, H, C, H ₂ O, or the like, among the sputtering gas components such as Ar and Kr, as impurities, but by suppressing the concentration of these impurities to 10 atom% or less. The same characteristics as when no impurities are contained can be obtained.
[0032]
The average composition ratios of the diffusion preventing layers 7 and 8 are the composition points A ((GeX) _90.0 O _0.0 N _10.0 ) and B (in the ternary composition diagram having (GeX) · O · N as vertices shown in FIG. (GeX) _83.4 O _13.3 N _3.3 ),
C ((GeX) _35.0 O _0.0 N _65.0 ), D ((GeX) _31.1 O _55.1 N _13.8 ),
Preferably within the range surrounded by
E ((GeX) _65.0 O _0.0 N _35.0 ), F ((GeX) _53.9 O _9.20 N _36.9 ),
C ((GeX) _35.0 O _0.0 N _65.0 ), D ((GeX) _31.1 O _55.1 N _13.8 ),
It is desirable to be within the range surrounded by.
[0033]
The basis of this composition range is that when either Ge or X not bonded to nitrogen or oxygen is excessively present (hereinafter referred to as surplus Ge or X), surplus Ge or X diffuses into the recording film, If there is an excessive amount of nitrogen or oxygen that is not bonded to Ge or X, the atoms tend to be infiltrated into the recording film and prevent recording. Show.
[0034]
The range of the average composition ratio of Ge · X contained in the diffusion preventing layers 7 and 8 is preferably such that X is 50 atom% or less with respect to Ge. The basis of the composition ratio of Ge · X is that if the X content is more than 50 atom% of the Ge content, the substance X tends to flow into the recording film after repeated recording and hinder the optical change of the recording film. When it is less than 10 atom%, the effect of adding the substance X to either GeN or GeON may not be so remarkable.
[0035]
The film thickness of the diffusion preventing layers 7 and 8 needs to be 1 nm or more. This is because when the film thickness is 1 nm or less, the effect as the diffusion preventing layer is lowered. As an upper limit of the film thickness of the diffusion preventing layer, for example, the recording film is incident on the recording light incident side. Is a range in which the laser light intensity capable of recording / reproducing can be obtained. The laser light intensity can be appropriately set depending on the laser power or the recording film material to be applied.
[0036]
Next, a method for manufacturing these optical information recording media will be described. As a method for producing the multilayer film constituting the optical information recording medium, a sputtering method, a vacuum deposition method, a CVD method or the like can be used. Here, a case where the sputtering method is used will be described as an example, and FIG. A schematic view of an example of the film forming apparatus is shown.
[0037]
A vacuum pump (not shown) is connected to the vacuum vessel 9 through an exhaust port 15 so that the inside of the vacuum vessel 9 can be kept at a high vacuum. A rare gas such as Ar, nitrogen, oxygen, or a mixed gas thereof can be supplied from the gas supply port 14 at a constant flow rate. In FIG. 3, reference numeral 10 denotes a substrate, which is attached to a driving device 11 for performing self-revolution of the substrate.
[0038]
Reference numeral 12 denotes a sputter target including a material component of the sputtered film, which is connected to the cathode 13. Here, a disk-shaped target having a diameter of 10 cm and a thickness of 6 mm was used as the target 12. Although not shown, the cathode 13 is connected to a DC power source or a high frequency power source through a switch. Further, the vacuum vessel 9 and the substrate 10 are kept at the anode by grounding the vacuum vessel 9.
[0039]
When the recording film 3 and the protective layer 2 are formed, a gas in which 2.5 vol.% Of nitrogen is mixed with Ar is supplied at a constant flow rate so that the total pressure becomes 1.0 mTorr and 0.5 mTorr, respectively. each cathode DC1.27W / cm ^2, was performed by introducing the power of RF5.10W / cm ^2.
[0040]
When the reflective layer 5 was formed, Ar gas was supplied at a total pressure of 3.0 mTorr, and power of DC 4.45 W / cm ² was applied. As a rare gas in the sputtering gas, a sputterable rare gas such as Kr is used in addition to Ar.
[0041]
When the diffusion prevention layers 7 and 8 are formed, a material containing Ge and X or Ge, X, and N is a target, and X is a material containing at least one element of La or Ni . The film forming gas is a mixed gas containing a rare gas and nitrogen and is manufactured by reactive sputtering. When the film quality is hard, or when the internal stress of the film is large, a layer having a good film quality may be obtained by mixing a trace amount of oxygen in the film forming gas as necessary.
[0042]
As an example of the present embodiment, in the configuration of the optical information recording medium shown in FIG. 1, (1) when the diffusion prevention layer 7 is GeN and the diffusion prevention layer 8 is GeNiN, the diffusion prevention layer 7 is GeN, The case where the diffusion preventing layer 8 is GeLaN is defined as (2). Further, as a comparative example, the case where the diffusion prevention layers 7 and 8 are both GeN is (0). The film thicknesses of the diffusion preventing layers 7 and 8 in the above (0) to (2) are 10 nm and 20 nm, respectively.
[0043]
Further, when forming the GeNiN layer, the GeLaN layer, and the GeN layer, the target materials are GeNi, GeLa, and Ge, respectively, and the ratio of the Ni and La atoms contained in the GeNiN film and the GeLaN film to the number of Ge atoms is Both were set to 25 atom%.
[0044]
Further, the sputtering gas for forming the diffusion preventing layers 7 and 8 is a mixed gas of Ar and nitrogen, the sputtering gas pressure is 10 mTorr, the sputtering power density is 6.37 W / cm ² , and all are made common. The nitrogen partial pressure in the sputtering gas when depositing the film is constant at 40 vol.%, And the nitrogen partial pressure in the sputtering gas when depositing the diffusion prevention layer 8 is vol. 20%, 30 vol.%, 40 vol. The film was formed while changing.
[0045]
The results of evaluating the above media are shown in (Table 1). The characteristic evaluation was performed on the weather resistance and the repeated recording characteristics. For evaluation of weather resistance, an accelerated test at 90 ° C. and 80% was performed for 200 hours, and the presence or absence of peeling was observed with an optical microscope every 100 hours. The case where no peeling was observed until 200 hours was indicated as ◯, the case where no peeling occurred after 100 hours, the case where peeling occurred after 200 hours, and the case where peeling was observed after 100 hours were indicated as x. .
[0046]
The recording repetitive characteristic is that when the shortest mark length is 0.61 μm by the EFM signal system, a mark having a length of 3T to 11T is recorded, and the jitter value between the front end and the rear end of the mark is divided by the window width T. If the value (hereinafter referred to as jitter value) does not exceed 13% for both the front end and rear end after 100,000 times of repetitive recording, ○ at least one of the front end and rear end jitter values after 100,000 times A value exceeding 13% was indicated as x.
[0047]
[Table 1]

[0048]
Further, the diffusion prevention layer 8 is made of GeN, the diffusion prevention layer 7 is made of GeNiN, and GeLaN, and the nitrogen partial pressure in the sputtering gas when forming the diffusion prevention layer 8 is constant at 30 vol.%, And the diffusion prevention layer 7 is formed. (3) and (4) respectively, except that the partial pressure of nitrogen in the sputtering gas was changed to 40 vol.%, 50 vol.%, And 60 vol.%. And As a comparative example in this case, a medium when the diffusion prevention layers 7 and 8 are both GeN is (0) ′. The results of evaluating these media are shown in (Table 2).
[0049]
[Table 2]

[0050]
As described above, from the results of (Table 1) and (Table 2), when GeNiN or GeLaN is used as the diffusion preventing layer, the weather resistance is improved without impairing the recording repetitive characteristics as compared with the case of using only GeN. I understand that.
[0051]
Next, the diffusion prevention layers 7 and 8 are GeN and GeNiN, respectively, and the ratio of the number of Cr atoms contained in the GeLaN film to the number of Ge atoms is 5%, 10%, 20%, 30%, 50%, and 60%. A disc having a changed shape is manufactured, and these media are sequentially designated as (5), (6), (7), (8), (9), and (10). The layer structure of the disk is the same as the above-described disks (0) to (4), the nitrogen partial pressure when forming the diffusion prevention layer 7 is constant at 40 vol.%, And that of the diffusion prevention layer 8 is vol. It was changed to 20%, 30vol.%, 40vol.%, 50vol.%, 60vol.%. The evaluation results of these disks are shown in (Table 3).
[0052]
[Table 3]

[0053]
From Table 3, it can be seen that when the Ni content is 10 atom% or more with respect to Ge, the effect of adding Ni begins to appear. However, when the Cr content is 60 atom% or more with respect to Ge, the recording repeatability deteriorates. This is thought to be because Ni is less likely to bond to nitrogen than Ge, and excess Cr that does not bond to nitrogen exists in the film excessively, and these atoms are infiltrated into the recording film, deteriorating the recording repetitive characteristics. . From the above, it can be said that the Ni content in the GeNiN film is preferably 50% or less with respect to Ge.
[0054]
In the above description, Ni and La have been described as examples of the X component. However, the element of X is not limited to Ni and La. As described above, X contained in the diffusion prevention layer is a repetition of information. Accordingly, even if it diffuses into the recording film, any element that has little influence on the optical properties of the recording film may be used. Such elements include other IIIa groups such as Au or Y in addition to Ni and La. There is an element, or other group VIII elements such as Fe and Co, and even if any of them is used, there is a slight difference in the effect, but there is essentially an effect of inclusion, and the content is almost the same. .
[0055]
【The invention's effect】
As described above, a diffusion prevention layer mainly composed of GeXN or GeXON is provided between the protective layer and the recording film in contact with at least one of the recording films, and the material component X of the diffusion prevention layer is La or with material containing at least one element of Ni, excellent weather resistance, and it is possible to obtain an excellent optical information recording medium in repetition characteristics of recording and erasing of information signals.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a single layer structure of an optical information recording medium according to an embodiment of the present invention.
FIG. 2 is a triangular composition diagram showing a composition range of (GeX) .O.N according to an embodiment of the present invention.
FIG. 3 is a diagram showing an example of a film forming apparatus according to an embodiment of the present invention.
4A and 4B are cross-sectional views showing a layer configuration example of a conventional optical information recording medium, in which A is a cross-sectional view of a four-layer optical recording medium and B is a cross-sectional view of a five-layer optical recording medium.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Substrate 2 Protective layer 3 Recording film 4 Protective layer 5 Reflective layer 6 Protective layer 7 Diffusion prevention layer 8 Diffusion prevention layer 9 Vacuum vessel 10 Substrate 11 Substrate driving device 12 Target 13 Cathode 14 Gas supply port 15 Exhaust port

Claims (8)

The optical characteristics reversibly change, and a recording film mainly composed of at least one element selected from Te, Se, and Sb, and at least one selected from GeXN and GeXON in contact with at least one side of the recording film. An optical information recording medium having a diffusion prevention layer mainly composed of one and a protective layer containing sulfur or sulfide, wherein the diffusion prevention layer is provided between the protective layer and the recording film. The optical information recording medium, wherein the material component X of the diffusion preventing layer contains at least one element selected from Ni and La .   A diffusion prevention layer mainly comprising at least one selected from GeXN and GeXON is in contact with both sides of the recording film, and the average content of the material component X of the diffusion prevention layer is different on both sides of the recording film. The optical information recording medium according to claim 1. The diffusion preventing layer mainly composed of at least one selected from GeXN and GeXON is in contact with both sides of the recording film, and the average composition of the diffusion preventing layer located on the laser incident side of the recording film is (Ge _{1 -y X y) a O b N} c ( where, a> 0, b ≧ 0 , c> 0,0 ≦ y ≦ 1), the average composition of the diffusion barrier layer located on the side opposite to the laser incident side (Ge _1-z X _z ) _d O _e N _f (where d> 0, e ≧ 0, f> 0, 0 ≦ z ≦ 1) and 0 ≦ y <z. An optical information recording medium according to any one of the above. The average composition ratio of Ge and X contained in the diffusion prevention layer mainly comprising at least one selected from GeXN and GeXON is (Ge _1-y X _y ) _a O _b N _c (where a> 0, 2. The optical information recording medium according to claim 1, being in a range represented by b ≧ 0, c> 0, 0 <y ≦ 0.5). In the ternary composition diagram in which the average composition ratio of the diffusion prevention layer mainly composed of at least one selected from GeXN and GeXON has (GeX) · O · N as vertices, the composition point A ((GeX) _90.0 O _0.0 N _10.0 ), B ((GeX) _83.4 O _13.3 N _3.3 ),
C ((GeX) _35.0 O _0.0 N _65.0 ), D ((GeX) _31.1 O _55.1 N _13.8 ),
The optical information recording medium according to claim 1, which is in a range surrounded by.   The optical information recording medium according to claim 1, wherein the thickness of the diffusion prevention layer containing at least one selected from GeXN and GeXON as a main component is 1 nm or more.   The optical information recording medium according to claim 1, wherein the recording film is a phase change material mainly composed of three elements of Te, Sb, and Ge. The optical characteristics reversibly change, and a recording film mainly composed of at least one element selected from Te, Se, and Sb, and at least one selected from GeXN and GeXON in contact with at least one side of the recording film. And a protective layer containing sulfur or sulfide, wherein the diffusion preventing layer is provided between the protective layer and the recording film. The diffusion prevention layer is formed by reactive sputtering in a mixed gas containing a rare gas and nitrogen using a material containing either Ge and X or Ge, X, or N as a target. The method for producing an optical information recording medium, wherein the material component X of the prevention layer contains at least one element selected from Ni and La .

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