JPH09198714A - Optical recording medium and information recording method - Google Patents
Optical recording medium and information recording methodInfo
- Publication number
- JPH09198714A JPH09198714A JP8004644A JP464496A JPH09198714A JP H09198714 A JPH09198714 A JP H09198714A JP 8004644 A JP8004644 A JP 8004644A JP 464496 A JP464496 A JP 464496A JP H09198714 A JPH09198714 A JP H09198714A
- Authority
- JP
- Japan
- Prior art keywords
- groove
- recording
- substrate
- recording medium
- wavelength
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 230000003287 optical effect Effects 0.000 title claims abstract description 37
- 238000000034 method Methods 0.000 title claims description 15
- 239000010410 layer Substances 0.000 claims abstract description 55
- 239000000758 substrate Substances 0.000 claims abstract description 52
- 229910052751 metal Inorganic materials 0.000 claims abstract description 15
- 239000002184 metal Substances 0.000 claims abstract description 15
- 239000011241 protective layer Substances 0.000 claims abstract description 11
- 230000009102 absorption Effects 0.000 claims description 12
- 238000010521 absorption reaction Methods 0.000 claims description 12
- 230000008033 biological extinction Effects 0.000 claims description 11
- 238000002835 absorbance Methods 0.000 claims description 6
- 229910052709 silver Inorganic materials 0.000 claims description 5
- 239000004332 silver Substances 0.000 claims description 5
- 239000011347 resin Substances 0.000 claims description 4
- 229920005989 resin Polymers 0.000 claims description 4
- 238000013213 extrapolation Methods 0.000 claims description 3
- 239000002356 single layer Substances 0.000 claims description 2
- 230000001678 irradiating effect Effects 0.000 claims 2
- 239000000975 dye Substances 0.000 description 30
- 230000004580 weight loss Effects 0.000 description 20
- 230000035945 sensitivity Effects 0.000 description 7
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 6
- 238000004528 spin coating Methods 0.000 description 6
- 230000007423 decrease Effects 0.000 description 5
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 4
- 238000000354 decomposition reaction Methods 0.000 description 4
- 239000004417 polycarbonate Substances 0.000 description 4
- 229920000515 polycarbonate Polymers 0.000 description 4
- 238000004904 shortening Methods 0.000 description 4
- 239000013585 weight reducing agent Substances 0.000 description 4
- 238000000862 absorption spectrum Methods 0.000 description 3
- 238000011156 evaluation Methods 0.000 description 3
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 3
- 229910052737 gold Inorganic materials 0.000 description 3
- 239000010931 gold Substances 0.000 description 3
- 239000000243 solution Substances 0.000 description 3
- 239000002904 solvent Substances 0.000 description 3
- KUGBQWBWWNPMIT-UHFFFAOYSA-N 1,1,2,2,3,3,4,4-octafluoropentan-1-ol Chemical compound CC(F)(F)C(F)(F)C(F)(F)C(O)(F)F KUGBQWBWWNPMIT-UHFFFAOYSA-N 0.000 description 2
- BNDRWEVUODOUDW-UHFFFAOYSA-N 3-Hydroxy-3-methylbutan-2-one Chemical compound CC(=O)C(C)(C)O BNDRWEVUODOUDW-UHFFFAOYSA-N 0.000 description 2
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 2
- 239000000987 azo dye Substances 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 238000004364 calculation method Methods 0.000 description 2
- SWXVUIWOUIDPGS-UHFFFAOYSA-N diacetone alcohol Chemical compound CC(=O)CC(C)(C)O SWXVUIWOUIDPGS-UHFFFAOYSA-N 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 2
- 238000011946 reduction process Methods 0.000 description 2
- 230000003595 spectral effect Effects 0.000 description 2
- 238000002411 thermogravimetry Methods 0.000 description 2
- JYAKNSNAABYQBU-UHFFFAOYSA-N 2h-dibenzofuran-1-one Chemical compound O1C2=CC=CC=C2C2=C1C=CCC2=O JYAKNSNAABYQBU-UHFFFAOYSA-N 0.000 description 1
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 description 1
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000011737 fluorine Substances 0.000 description 1
- 229910052731 fluorine Inorganic materials 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- BBKFSSMUWOMYPI-UHFFFAOYSA-N gold palladium Chemical compound [Pd].[Au] BBKFSSMUWOMYPI-UHFFFAOYSA-N 0.000 description 1
- 230000020169 heat generation Effects 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 238000001746 injection moulding Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- QSHDDOUJBYECFT-UHFFFAOYSA-N mercury Chemical compound [Hg] QSHDDOUJBYECFT-UHFFFAOYSA-N 0.000 description 1
- 229910052753 mercury Inorganic materials 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 239000011733 molybdenum Substances 0.000 description 1
- 239000012299 nitrogen atmosphere Substances 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 229910052763 palladium Inorganic materials 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 229920003229 poly(methyl methacrylate) Polymers 0.000 description 1
- 229920005668 polycarbonate resin Polymers 0.000 description 1
- 239000004431 polycarbonate resin Substances 0.000 description 1
- 229920000193 polymethacrylate Polymers 0.000 description 1
- 239000004926 polymethyl methacrylate Substances 0.000 description 1
- 229920000098 polyolefin Polymers 0.000 description 1
- 239000013074 reference sample Substances 0.000 description 1
- 229910052703 rhodium Inorganic materials 0.000 description 1
- 239000010948 rhodium Substances 0.000 description 1
- MHOVAHRLVXNVSD-UHFFFAOYSA-N rhodium atom Chemical compound [Rh] MHOVAHRLVXNVSD-UHFFFAOYSA-N 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 229910052715 tantalum Inorganic materials 0.000 description 1
- GUVRBAGPIYLISA-UHFFFAOYSA-N tantalum atom Chemical compound [Ta] GUVRBAGPIYLISA-UHFFFAOYSA-N 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
- 239000010936 titanium Substances 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 1
- 229910052721 tungsten Inorganic materials 0.000 description 1
- 239000010937 tungsten Substances 0.000 description 1
- 229910052720 vanadium Inorganic materials 0.000 description 1
- LEONUFNNVUYDNQ-UHFFFAOYSA-N vanadium atom Chemical compound [V] LEONUFNNVUYDNQ-UHFFFAOYSA-N 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
- 229910052726 zirconium Inorganic materials 0.000 description 1
Landscapes
- Optical Head (AREA)
- Optical Record Carriers And Manufacture Thereof (AREA)
- Optical Recording Or Reproduction (AREA)
Abstract
(57)【要約】
【課題】 特に短波長のレーザー光での記録、再生に適
した光記録媒体を提供する。
【解決手段】トラックピッチが０.７〜１.０μｍである
案内溝を有する透明基板上に、少なくとも、有機色素を
含有する記録層、金属反射層、保護層の順に積層した光
記録媒体において、下記（イ）〜（ハ）の特徴を有する
光記録媒体。
（イ）記録層が波長６００ｎｍ〜７００ｎｍのレーザー
光により光学的な変化を生じるものであること。
（ロ）基板の溝の壁の傾斜が７０〜８５度であること。
（ハ）基板の溝幅が０.３〜０.３７μｍであること。
(57) An object of the present invention is to provide an optical recording medium particularly suitable for recording and reproducing with a laser beam having a short wavelength. An optical recording medium in which at least a recording layer containing an organic dye, a metal reflective layer, and a protective layer are laminated in this order on a transparent substrate having a guide groove having a track pitch of 0.7 to 1.0 μm, An optical recording medium having the following characteristics (a) to (c). (A) The recording layer has an optical change caused by laser light having a wavelength of 600 nm to 700 nm. (B) The inclination of the wall of the groove of the substrate is 70 to 85 degrees. (C) The groove width of the substrate is 0.3 to 0.37 μm.
Description
【０００１】[0001]
【発明の属する技術分野】本発明はレーザー光により記
録できる光記録媒体及びそれを用いた情報記録方法に関
する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical recording medium which can be recorded with a laser beam and an information recording method using the same.
【０００２】[0002]
【従来の技術】近年、高密度記録のため、レーザー光の
発振波長の短波長化が注目され、７８０ｎｍ、８３０ｎ
ｍよりも短波長のレーザー光で記録再生可能な光記録媒
体が求められている。かかる状況においては、さまざま
な記録媒体があるが、その中で、有機色素系光記録媒体
はプロセスが比較的簡便であるため安価であるという特
長を有する。2. Description of the Related Art In recent years, attention has been paid to shortening the oscillation wavelength of laser light for high-density recording.
There is a demand for an optical recording medium capable of recording and reproducing with a laser beam having a wavelength shorter than m. In such a situation, there are various recording media, and among them, the organic dye-based optical recording medium has a feature that it is inexpensive because the process is relatively simple.
【０００３】ところで、有機色素系光記録媒体として
は、ＣＤとの互換性があるタイプの光ディスク（ＣＤ−
Ｒ）が７８０ｎｍのレーザー光に対応するもので既に実
用化されている。一方、短波長用途の有機色素系媒体と
して数々の提案があり、例えば、特開平７ー７６１６９
号公報、特開平７ー１２５４４１号公報、等がある。し
かしながら、これらは、７８０ｎｍでのＣＤーＲの知見
を単に短波長用に適用したものであり、短波長化のメリ
ットである、微小記録部形成による高容量化を実現する
ための、短波長化での特有の要請を満たす要件が明らか
にされていない。By the way, as an organic dye-based optical recording medium, an optical disc of a type compatible with a CD (CD-
R) corresponds to a laser beam of 780 nm and has already been put to practical use. On the other hand, there are various proposals as an organic dye-based medium for short wavelength applications, for example, Japanese Patent Laid-Open No. 7-76169.
And Japanese Patent Laid-Open No. 7-125441. However, these are merely the findings of the CD-R at 780 nm applied for short wavelengths, and the wavelength shortening for realizing high capacity by forming a minute recording portion, which is an advantage of shortening the wavelength, is Requirements to meet the specific requirements of the
【０００４】また、溝形状に関しては、特開平４ー３５
８３３１号公報、特開平５ー１９８０１３号公報、特開
平５ー２７７１号公報、特開平４ー１０９４４１号公
報、特開平３ー２２２２４号公報等があり、７８０ｎｍ
近傍の波長については知見が示されているが、短波長化
については明らかにされていない。Regarding the groove shape, Japanese Patent Laid-Open No. 4-35
No. 8331, JP-A-5-198013, JP-A-5-2771, JP-A-4-109441, JP-A-3-22224, etc. are available at 780 nm.
Although knowledge has been shown about wavelengths in the vicinity, it has not been clarified about wavelength shortening.
【０００５】[0005]
【発明が解決しようとする課題】上記の従来技術におい
ては、記録時に、色素の分解のみか、基板の変形と色素
の分解の両方により記録変調度を得ているが、かかる方
法では記録部の変形が大きく、溝上記録の場合には隣接
の溝間部に及ぶ大きなピットが形成されるため、高密度
化のためにトラックピッチを１.６μｍから１μｍ以下
に狭くした場合に、隣接する溝間で影響を与える、いわ
ゆるクロストークが問題となる。また、従来の溝設計で
は、高密度化用に開口数（ＮＡ）の大きなレーザーヘッ
ドを使用する際に、ビーム径よりも大きな記録ビットを
形成するために、記録部と未記録部の反射率コントラス
トを有効に得ることが困難である。In the above-mentioned prior art, the recording modulation degree is obtained at the time of recording only by the decomposition of the dye or both the deformation of the substrate and the decomposition of the dye. If the track pitch is narrowed from 1.6 μm to 1 μm or less in order to achieve high density, a large pit is formed because the deformation is large and the area between adjacent grooves is formed in the case of recording on the groove. There is a problem of so-called crosstalk, which affects in. Further, in the conventional groove design, when a laser head having a large numerical aperture (NA) is used for high density, a recording bit larger than the beam diameter is formed, so that the reflectance of the recorded portion and the unrecorded portion is increased. It is difficult to obtain the contrast effectively.
【０００６】[0006]
【課題を解決するための手段】本発明者らは、高密度記
録を実現されるために良好な微小記録部を形成し、か
つ、十分な記録変調度を有する波長６００〜７００ｎｍ
の短波長記録に好適な溝形状と記録媒体を鋭意検討した
結果、特定の溝幅、特定の溝壁の傾斜角度により特に短
波長記録に適した光記録媒体が得られることを見出し、
本発明に到達した。DISCLOSURE OF THE INVENTION The inventors of the present invention have formed a fine recording portion suitable for realizing high-density recording and have a wavelength of 600 to 700 nm having a sufficient recording modulation degree.
As a result of diligent examination of a groove shape and a recording medium suitable for short wavelength recording, it was found that an optical recording medium particularly suitable for short wavelength recording can be obtained by a specific groove width and a specific groove wall inclination angle,
The present invention has been reached.
【０００７】すなわち、本発明の目的は短波長のレーザ
ー光を用いた高密度記録に適した光記録媒体を提供する
ことにあり、かかる目的は、透明基板上に、少なくと
も、有機色素を含有する記録層、金属反射層、保護層の
順に積層した光記録媒体において、下記（イ）〜（ハ）
の特徴を有する光記録媒体により達成される。 （イ）記録層が波長６００ｎｍ〜７００ｎｍのレーザー
光により光学的な変化を生じるものであること。 （ロ）基板の溝の壁の傾斜角が７０〜８５度であるこ
と。 （ハ）基板の溝幅が０.３〜０.３７μｍであること。That is, an object of the present invention is to provide an optical recording medium suitable for high density recording using a laser beam of a short wavelength. An object of the present invention is to contain at least an organic dye on a transparent substrate. In an optical recording medium in which a recording layer, a metal reflection layer, and a protective layer are laminated in this order, the following (a) to (c)
This is achieved by an optical recording medium having the characteristics of (A) The recording layer has an optical change caused by laser light having a wavelength of 600 nm to 700 nm. (B) The inclination angle of the wall of the groove of the substrate is 70 to 85 degrees. (C) The groove width of the substrate is 0.3 to 0.37 μm.
【０００８】[0008]
【発明の実施の形態】以下、本発明の実施の形態につい
て説明する。本発明における記録層は、記録用のレーザ
ー光を吸収することによる昇温で減量し、膜厚が減少
し、光学特性が変化することにより、戻り光の位相が変
化し、反射率が変化したところを記録部とするものであ
る。BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. The recording layer in the present invention is reduced in temperature by increasing the temperature by absorbing the laser beam for recording, the film thickness is reduced, and the optical characteristics are changed, the phase of the return light is changed, and the reflectance is changed. However, the recording unit is used.
【０００９】本発明において、透明基板としてはポリカ
ーボネート、ポリメタクリレート、非晶質ポリオレフィ
ン等の樹脂やガラス等の公知のものが用いられ、特にポ
リカーボネート樹脂が好ましい。また、透明基板はサー
ボ用の案内溝を有しており、その溝は、深さは、通常１
００〜２００ｎｍ、好ましくは、１４０〜２００ｎｍで
ある。溝の深さが１００ｎｍ未満の場合には、記録時に
十分な変化がおきず、十分な記録変調度が得られない場
合がある。２００ｎｍを越えると、溝部と溝間部の反射
率差が大きすぎるため、溝上記録の場合には反射率が低
くなりすぎるので好ましくない。In the present invention, as the transparent substrate, resins such as polycarbonate, polymethacrylate and amorphous polyolefin, and known materials such as glass are used, and polycarbonate resin is particularly preferable. Further, the transparent substrate has a guide groove for servo, and the groove has a depth of usually 1
It is from 00 to 200 nm, preferably from 140 to 200 nm. If the depth of the groove is less than 100 nm, a sufficient change may not occur during recording, and a sufficient recording modulation degree may not be obtained. If it exceeds 200 nm, the reflectance difference between the groove portion and the inter-groove portion is too large, and the reflectance is too low in the case of recording on the groove, which is not preferable.
【００１０】また、本発明では、前記案内溝の溝幅を
０.３〜０.３７μｍ、溝の壁の傾斜を７０〜８５度とす
ることが重要である。溝幅は、０．３μｍ未満には基板
の溝転写率が低くなる上に、プッシュプル信号が小さい
ためトラッキングがかかりにくくなり、また、０．３７
μｍを越える溝幅の場合には、記録層をスピンコートす
ることによっては十分狭い記録層の溝幅が得られなくな
り、従って、光ビームスポットの半値全幅（＝０.５２
λ/ＮＡ：λは波長。ＮＡは、レーザー光集束用レンズ
の開口数）に対して十分狭い記録層の溝を形成すること
が困難となる。一般に、ビーム径よりも十分狭い溝幅
は、広くなることにより反射率が低下し、その変化率
は、初期の溝幅が狭いほど大きい。すなわち、記録によ
り、溝幅が大きくなるような記録媒体の場合には、記録
による膜厚変化と光学定数の変化による位相差に由来す
る記録コントラストに加えて、未記録部の溝幅が狭いほ
ど大きな記録変調度が期待されるということになる。ま
た、基板の溝の壁の傾斜角は、７０〜８５度である。７
０度よりも小さい場合には、相対的に溝幅が広くなるの
で、記録前後の溝幅変化の効果が小さくなるので好まし
くない。また、８５度よりも大きい傾斜角で、１μｍ以
下のトラックピッチの射出成形をプラスチック基板で実
現することは技術的に困難である。なお、溝深さと溝幅
は、トラックピッチが１μｍの場合にはＨｅーＣｄレー
ザーによる光学測定で求め、それよりもトラックピッチ
が狭い場合には、ＳＴＭにより求めることができる。そ
の場合、基板の溝幅は溝深さの半分のところの溝幅であ
り、記録による基板の溝幅の変化量は、走査電子顕微鏡
による基板の溝部の写真により求めた値である。また、
溝の壁の傾斜角はＳＴＭ、ＡＦＭにより求められるが、
本件に関しては、ＳＴＭでプロファイルを測定し、溝間
部の水平線と溝の壁にひいた接線の成す角度を求める傾
斜角（図１中のθ）とした。In the present invention, it is important that the groove width of the guide groove is 0.3 to 0.37 μm and the inclination of the groove wall is 70 to 85 degrees. When the groove width is less than 0.3 μm, the groove transfer rate of the substrate is low, and the push-pull signal is small, which makes tracking difficult.
When the groove width exceeds μm, a sufficiently narrow groove width of the recording layer cannot be obtained by spin-coating the recording layer, and therefore, the full width at half maximum (= 0.52) of the light beam spot is obtained.
λ / NA: λ is the wavelength. NA makes it difficult to form a groove in the recording layer that is sufficiently narrow with respect to the numerical aperture of the laser beam focusing lens. In general, a groove width that is sufficiently narrower than the beam diameter becomes wider, so that the reflectance decreases, and the rate of change becomes larger as the initial groove width becomes narrower. That is, in the case of a recording medium in which the groove width is increased by recording, in addition to the recording contrast resulting from the phase difference due to the change in film thickness due to recording and the change in the optical constant, the narrower the groove width in the unrecorded portion is It means that a large recording modulation degree is expected. The inclination angle of the wall of the groove of the substrate is 70 to 85 degrees. 7
When it is smaller than 0 degree, the groove width becomes relatively wide, and the effect of changing the groove width before and after recording becomes small, which is not preferable. Further, it is technically difficult to realize injection molding with a track pitch of 1 μm or less on a plastic substrate with an inclination angle larger than 85 degrees. The groove depth and groove width can be obtained by optical measurement with a He-Cd laser when the track pitch is 1 μm, and can be obtained by STM when the track pitch is narrower than that. In that case, the groove width of the substrate is the groove width at a half of the groove depth, and the amount of change in the groove width of the substrate due to recording is a value determined by a photograph of the groove portion of the substrate by a scanning electron microscope. Also,
The inclination angle of the wall of the groove is obtained by STM and AFM.
In this case, the profile was measured by STM, and the inclination angle (θ in FIG. 1) was obtained to obtain the angle between the horizontal line between the grooves and the tangent line drawn to the wall of the groove.
【００１１】さらに、基板の溝間部の平坦部（Ｌｐ）
が、溝の両脇の壁の接線と平坦部を含む平面との交線間
で表される平坦部外挿部（Ｌ）（図２にＬｐとＬの関係
を示す）の４５〜９５％、特に５０〜９５％であること
が好ましい。なお、図２にＬｐとＬの関係を示す。Ｌｐ
がＬの４５％未満であると、スピンコート法によって記
録層を形成すると、溝間部の塗布液が溝部に落ち込み、
溝間部の記録層厚が著しく薄くなり、溝間部と溝部の膜
厚のバランスが損なわれるため、良好な記録特性が得ら
れない恐れがある。Further, the flat portion (Lp) between the grooves of the substrate
Is 45 to 95% of the flat portion extrapolation portion (L) (the relationship between Lp and L is shown in FIG. 2) expressed between the tangents of the walls on both sides of the groove and the intersecting line of the plane including the flat portion. , Especially preferably 50 to 95%. The relationship between Lp and L is shown in FIG. Lp
Is less than 45% of L, when the recording layer is formed by the spin coating method, the coating liquid in the inter-groove portion falls into the groove portion,
Since the recording layer thickness in the inter-groove portion is remarkably thin and the film thickness balance between the inter-groove portion and the groove portion is impaired, good recording characteristics may not be obtained.
【００１２】記録層は、通常、有機色素等をエタノー
ル、３ーヒドロキシー３ーメチルー２ーブタノン、ジア
セトンアルコール、フッ素系アルコール等の溶媒に溶か
した溶液をスピンコートして得られる。この溶媒として
は、沸点が１００〜１８０℃である溶媒が特に好ましく
用いられる。膜厚は溝部で１００〜２５０ｎｍ程度が好
ましい。１００ｎｍ未満では薄すぎて良好な記録感度が
得られにくい。また、２５０ｎｍを越えると、記録部の
横方向への変形が大きくなるため、クロストークが大き
くなり、好ましくない。基板の溝深さと膜の厚さの両方
を含むパラメータとして、記録層の溝深さがある。これ
は、保護層のない状態では反射層の上から、また、保護
層のある場合では、保護層を剥離し、記録層が残ってい
る部分に金や、金ーパラジウムを５ｎｍ程度、イオンス
パッタした層の上から、ＳＴＭ、ＡＦＭにより測定して
得られる。この溝深さが、同じ方法で測定して得られた
基板の溝深さの４０〜７５％であると、良好な特性が得
られる。４０％未満の場合には、十分なトラッキングエ
ラー信号が得られず、サーボがかかりにくくなるおそれ
がある。また、７５％を越える場合、膜厚が小さすぎ
て、十分な記録変調度が得られにくい。The recording layer is usually obtained by spin-coating a solution in which an organic dye or the like is dissolved in a solvent such as ethanol, 3-hydroxy-3-methyl-2-butanone, diacetone alcohol, or a fluorine-containing alcohol. As this solvent, a solvent having a boiling point of 100 to 180 ° C. is particularly preferably used. The film thickness in the groove is preferably about 100 to 250 nm. If it is less than 100 nm, it is too thin to obtain good recording sensitivity. On the other hand, if it exceeds 250 nm, the deformation of the recording portion in the lateral direction becomes large, and crosstalk becomes large, which is not preferable. The groove depth of the recording layer is a parameter that includes both the groove depth of the substrate and the film thickness. This is because the protective layer was peeled off from above the reflective layer when there was no protective layer, and when the protective layer was present, the protective layer was peeled off, and gold or gold-palladium was ion-sputtered to a portion where the recording layer remained by about 5 nm. Obtained by measuring with STM or AFM from above the layer. Good characteristics are obtained when the groove depth is 40 to 75% of the groove depth of the substrate obtained by the same method. If it is less than 40%, a sufficient tracking error signal may not be obtained, and servo may not be applied easily. On the other hand, if it exceeds 75%, the film thickness is too small to obtain a sufficient recording modulation.
【００１３】記録層を構成する有機色素の熱的特性は記
録特性に大きく影響する。短波長用途として充分な特性
を得るためには、熱重量分析における、主減量過程での
減量が、温度に対してシャープであることが必要であ
り、本発明では、主減量過程での減量の傾きが２％/℃
以上、好ましくは、１０％/℃となる有機色素を用いる
ことが好ましい。なお、ここでは、いくつかの減量過程
のうちで減量が１８％以上の過程を主減量過程と呼ぶ。The thermal characteristics of the organic dye forming the recording layer greatly affect the recording characteristics. In order to obtain sufficient characteristics as a short-wavelength application, it is necessary that the weight loss in the thermogravimetric analysis in the main weight loss process is sharp with respect to the temperature. Slope is 2% / ℃
As described above, it is preferable to use an organic dye having a concentration of 10% / ° C. It should be noted that, of the several weight reduction processes, the process in which the weight reduction is 18% or more is referred to as the main weight reduction process.
【００１４】本発明において、減量の傾きは、以下の如
くして求める。（図３を参照。） 質量Ｍ0の有機色素を窒素雰囲気で１０℃/分で昇温す
る。昇温に従って、質量は当初微量ずつ減少し、ほぼ直
線ａーｂの減量線を描き、ついで急激に減量し始め、１
８％以上の減量をほぼ直線ｄ1ーｄ2に沿って減量する。
これが主減量過程であり、主減量開始温度は、Ｔ1のこ
とである。その後、ほぼ直線ｃ−ｃで示される減量過程
におちつく。直線ｄ1−ｄ2と直線ｃ−ｃとの交点におけ
る温度をＴ 2、重量をｍ2とし、初期重量をｍ1とすれ
ば、ここでいう減量の傾きとは、In the present invention, the slope of weight loss is as follows.
Ask for it. (See FIG. 3.) Mass M0Temperature of organic dye of 10 ℃ / min in nitrogen atmosphere
You. As the temperature rises, the mass initially decreases by a small amount,
Draw a weight loss line a-b, then start abrupt weight loss 1
Weight loss of 8% or more almost straight line d1-DTwoTo lose weight.
This is the main weight loss process, and the main weight loss start temperature is T1Saw
And After that, the weight loss process shown by the substantially straight line cc
Get sick. Straight line d1-DTwoAnd at the intersection of the straight line cc
Temperature T Two, Weight mTwoAnd the initial weight is m1Tomorrow
For example, the slope of weight loss referred to here is
【００１５】[0015]
【数１】（ｍ1−ｍ2）（％）／（Ｔ2−Ｔ1）（℃） で示される値である。この傾きが２％/℃未満である有
機色素を用いると、記録部の横方向の広がりが大きくな
り、また、短ビットの形成が困難となりやすく、高容量
化を目的とする短波長用途に向かない。さらに、この主
減量過程での総減量は当初質量Ｍ0の２５％以上、好ま
しくは、３０％以上であることが好ましい。２５％未満
であると、良好な記録変調度、記録感度が得られない恐
れがある。なお、主減量開始温度は２５０℃〜３４０℃
が好ましい。[Equation 1] (m 1 −m 2 ) (%) / (T 2 −T 1 ) (° C.) If an organic dye having this slope of less than 2% / ° C. is used, the lateral spread of the recording area becomes large, and it becomes difficult to form short bits, which is suitable for short wavelength applications for high capacity. It doesn't. Furthermore, it is preferable that the total weight loss in the main weight loss process is 25% or more, preferably 30% or more of the initial mass M 0 . If it is less than 25%, good recording modulation and recording sensitivity may not be obtained. The main weight reduction start temperature is 250 ° C to 340 ° C.
Is preferred.
【００１６】有機色素としては、上記の要件を満足する
ものであればいずれでもよく、例えば、含金属アゾ系色
素や、ジベンゾフラノン系、含金属インドアニリン系色
素等がある。また、これらの有機色素を２種以上混ぜて
使用してもよい。また、記録再生波長±５ｎｍの波長領
域の光に対する記録層単層の屈折率ｎが２〜３であり、
消衰係数ｋが０.０３から０.１５であるものが好まし
い。また、溶液でのモル吸光係数εが５万以上の吸収で
最も長波長側の吸収極大に対応する、透明基板上の膜の
状態での吸収極大が、記録再生波長よりも４０〜６０ｎ
ｍ短波長側にあることが好ましい。溶液での吸収極大
が、基板上のスピンコート膜の状態では長波長シフトす
ることが多いので、透明基板上での吸収極大で判断する
ことが必要である。屈折率ｎが２よりも小さい場合に
は、十分な光学的変化が得られにくいため、記録変調度
が低くなるので好ましくない。また、消衰係数ｋが０．
０３未満では記録感度が悪くなる。消衰係数ｋが０.１
５を越えると、５０％以上の反射率を得ることが困難と
なるので好ましくない。波長についても、上記範囲をは
ずれる場合には、十分な記録変調度と感度を得にくくな
る。Any organic dye may be used as long as it satisfies the above requirements, and examples thereof include metal-containing azo dyes, dibenzofuranone dyes and metal-containing indoaniline dyes. Further, two or more kinds of these organic dyes may be mixed and used. Further, the refractive index n of the recording layer single layer for light in the wavelength region of recording / reproducing wavelength ± 5 nm is 2 to 3,
The extinction coefficient k is preferably 0.03 to 0.15. In addition, the absorption maximum in the state of the film on the transparent substrate, which corresponds to the absorption maximum on the longest wavelength side when the molar absorption coefficient ε in the solution is 50,000 or more, is 40 to 60n more than the recording / reproducing wavelength.
It is preferably on the shorter wavelength side. Since the absorption maximum in a solution often shifts to a long wavelength in the state of the spin coat film on the substrate, it is necessary to judge the absorption maximum on the transparent substrate. When the refractive index n is smaller than 2, it is difficult to obtain a sufficient optical change and the recording modulation degree becomes low, which is not preferable. Further, the extinction coefficient k is 0.
If it is less than 03, the recording sensitivity becomes poor. Extinction coefficient k is 0.1
When it exceeds 5, it becomes difficult to obtain a reflectance of 50% or more, which is not preferable. When the wavelength is out of the above range, it becomes difficult to obtain a sufficient recording modulation degree and sensitivity.
【００１７】なお、色素膜の屈折率ｎ、消衰係数ｋの正
確な値を求めることはそれほど容易ではなく、むしろ色
素膜の分光吸収スペクトルが容易に測定でき、かつ、反
射率、記録変調度、記録感度に大きく影響を与えるパラ
メータとして有用である。有機色素の、ディスク基板上
に膜として形成された状態での分光吸収スペクトルにお
いて、上記要件を満たす吸収極大の吸光度に対して、記
録再生光波長での吸光度が５〜１５％である場合、良好
な特性を示す。５％未満の場合には十分な記録感度が得
られにくい。１５％を越える場合、屈折率ｎが小さくな
り、十分な記録変調度が得られない。なお、分光吸収ス
ペクトル（Ａｂｓｏｒｂａｎｃｅ）は、参照サンプルを
空気にし、透明基板上の案内溝のある面上に色素をスピ
ンコートし、基板側から光を入射して測定することがで
きる。なお、吸光度の比は、基板の吸収分に相当するベ
ースラインを差し引いた値を吸光度として計算する。It is not so easy to obtain accurate values of the refractive index n and the extinction coefficient k of the dye film, but rather the spectral absorption spectrum of the dye film can be easily measured, and the reflectance and recording modulation degree can be easily measured. It is useful as a parameter that greatly affects the recording sensitivity. In the spectroscopic absorption spectrum of the organic dye formed as a film on the disk substrate, when the absorbance at the recording / reproducing light wavelength is 5 to 15% with respect to the absorbance at the absorption maximum satisfying the above requirements, it is good. Shows the characteristic. If it is less than 5%, it is difficult to obtain sufficient recording sensitivity. If it exceeds 15%, the refractive index n becomes small and a sufficient recording modulation cannot be obtained. The spectral absorption spectrum (Absorbance) can be measured by using a reference sample as air, spin-coating a dye on the surface of the transparent substrate having the guide groove, and making light incident from the substrate side. The absorbance ratio is calculated as a value obtained by subtracting the baseline corresponding to the absorption of the substrate.
【００１８】金属反射層は、記録層を透過したレーザー
光を効率良く反射する金属膜であり、６００ｎｍ〜７０
０ｎｍで反射率が低下しないために、記録再生波長±５
ｎｍの波長領域の光の屈折率ｎが０.１〜０.２、消衰係
数ｋが３〜５であるものが好ましい。好ましい金属反射
膜として、金を主成分とした金属反射膜や、銀を主成分
とした金属反射膜が例示できる。特に銀を主成分とした
金属反射膜は、より高い反射率が得られ、安価であるこ
とから好ましい。また、対候性の向上のために、銀に、
ロジウム、パラジウム、白金、チタン、モリブデン、ジ
ルコニウム、タンタル、タングステン、バナジウム等の
添加元素を５原子％以下の範囲で加えてもよい。金属反
射層の膜厚は、好ましくは６０ｎｍ以上で、記録層の変
形を抑制しすぎたり、記録感度を悪化させすぎない程度
の膜厚が好ましい。The metal reflection layer is a metal film that efficiently reflects the laser light that has passed through the recording layer, and is 600 nm to 70 nm.
Since the reflectance does not decrease at 0 nm, the recording / reproducing wavelength ± 5
It is preferable that the refractive index n of light in the wavelength region of nm is 0.1 to 0.2 and the extinction coefficient k is 3 to 5. Preferred examples of the metal reflection film include a metal reflection film containing gold as a main component and a metal reflection film containing silver as a main component. In particular, a metal reflective film containing silver as a main component is preferable because it can obtain a higher reflectance and is inexpensive. In addition, to improve weather resistance, silver
Additional elements such as rhodium, palladium, platinum, titanium, molybdenum, zirconium, tantalum, tungsten, and vanadium may be added in a range of 5 atomic% or less. The thickness of the metal reflective layer is preferably 60 nm or more, and is preferably such that the deformation of the recording layer is not suppressed too much or the recording sensitivity is not deteriorated too much.
【００１９】反射層の上に、保護層を積層し、記録部の
金属反射層の穴の発生や、変形の非対称性を抑制する。
保護層としては紫外線硬化樹脂が好ましい。また、通常
は、１μｍ以上、好ましくは３μｍ以上の膜厚にして、
酸素による硬化抑制等がおこらないようにする。本発明
では、記録により記録部の色素が分解し、減量すること
によって膜厚、屈折率ｎ、消衰係数ｋが変化することに
よる位相差の変化に加えて、基板の溝幅が広くなること
による反射率の変化が、記録変調度に寄与している。図
４に一般的な光学計算結果を示す。図４は記録層の屈折
率ｎを２．４、消衰係数ｋを０．０８、溝深さを１００
ｎｍとしたときの溝幅と反射率との関係を計算で求めた
相関関係を示すグラフである。記録層の屈折率ｎ、消衰
係数ｋが変わらないと仮定した場合でも、溝幅が狭いほ
ど、溝幅の変化による反射率変化が大きい。実際には、
記録の前後で記録層の屈折率ｎ、消衰係数ｋが変化する
こと、さらに、スピンコート膜による溝の埋まり方に起
因する実効的な溝幅の減少という２つの点から、計算以
上に溝幅の変化の反射率変化への寄与が大きいと考えら
れる。さらに、この記録部の基板の溝幅増大という変化
は、色素層の分解と十分な発熱がおこり、記録層の光学
定数変化が起こり、かつ、色素層の膜厚が減少してピッ
トができている場合に見られる。色素層の分解によるピ
ットの生成により、再生光の位相差への寄与があり、即
ち、記録部の反射率が位相差により低下して、より大き
な記録変調度が得られる。このような記録部の位相差
は、Ｊａｐ.Ｊ.Ａｐｐｌ.Ｐｈｙｓ.３１（１９９２）４
８４ー４９３に示されるように、一般的にはA protective layer is laminated on the reflection layer to suppress the formation of holes in the metal reflection layer of the recording portion and the asymmetry of deformation.
As the protective layer, an ultraviolet curable resin is preferable. Further, usually, the film thickness is 1 μm or more, preferably 3 μm or more,
Make sure that oxygen does not inhibit curing. In the present invention, the dye in the recording portion is decomposed by recording and the amount is reduced, so that the groove width of the substrate is widened in addition to the change of the phase difference due to the change of the film thickness, the refractive index n, and the extinction coefficient k. The change in the reflectance due to the above contributes to the recording modulation degree. FIG. 4 shows a general optical calculation result. FIG. 4 shows that the refractive index n of the recording layer is 2.4, the extinction coefficient k is 0.08, and the groove depth is 100.
It is a graph which shows the correlation calculated | required by the calculation of the groove width and reflectance in nm. Even if it is assumed that the refractive index n and the extinction coefficient k of the recording layer do not change, the smaller the groove width, the larger the change in reflectance due to the change in groove width. actually,
From the two points that the refractive index n and the extinction coefficient k of the recording layer change before and after recording, and the effective groove width decreases due to the way the groove is filled with the spin coat film, the groove is more than calculated. It is considered that the contribution of the width change to the reflectance change is large. Furthermore, the change in the increase in the groove width of the substrate of the recording portion causes the decomposition of the dye layer and sufficient heat generation, the change of the optical constant of the recording layer occurs, and the film thickness of the dye layer decreases to form pits. Seen when you are. The generation of pits due to the decomposition of the dye layer contributes to the phase difference of the reproduction light, that is, the reflectance of the recording portion is reduced by the phase difference, and a larger recording modulation degree can be obtained. The phase difference of such a recording portion is described in Jap. J. Appl. Phys. 31 (1992) 4
In general, as shown in 84-493,
【００２０】[0020]
【数２】位相差＝２（ＮdyeーＮsub）ｘ（Ｄbump）＋２
ｘ（Ｎdye）ｘ（Ｄpit） （Ｎは、それぞれ、色素層、基板の屈折率：Ｄはそれぞ
れ、基板の溝深さの変化量、色素層ピット深さ）で示さ
れ、この式からわかるように、ピット形成の寄与は大き
い。基板の溝幅の変化は、それ自体の寄与効果（図４参
照）とともに、この様な記録層の光学変化（位相変化）
に大きく寄与するパラメータであり、それゆえ、記録変
調度は溝幅の変化に大きく依存する。この溝幅の変化の
割合は、本発明者らが検討した結果、未記録部の溝幅に
対して２０〜４０％広くなると、良好な記録変調度が得
られることが判明した。２０％未満では、十分な反射率
変化が得られない恐れがある。４０％を越えると、記録
前後のトラッキングエラー信号の変化が大きすぎるた
め、サーボがかからなくなることがある。なお、基板の
溝幅の変化は、記録層を除去した形で、光学顕微鏡や電
子顕微鏡で観察できる。記録層は、ディスク面に傷をつ
け、両面テープで保護層ならびに反射層を剥離した後、
エタノール等で色素を十分流しとることにより除去する
ことができる。[Equation 2] Phase difference = 2 (Ndye-Nsub) x (Dbump) + 2
x (Ndye) x (Dpit) (N is the dye layer and the refractive index of the substrate: D is the amount of change in the groove depth of the substrate, and the dye layer pit depth). In addition, the contribution of pit formation is large. The change in the groove width of the substrate, together with its own contribution effect (see FIG. 4), causes such an optical change (phase change) of the recording layer.
Is a parameter that greatly contributes to the recording width, and therefore the recording modulation degree largely depends on the change in the groove width. As a result of examination by the present inventors, it has been found that a good recording modulation degree can be obtained when the groove width variation is 20 to 40% wider than the groove width of the unrecorded portion. If it is less than 20%, a sufficient change in reflectance may not be obtained. If it exceeds 40%, the change in the tracking error signal before and after recording is too large, and the servo may not be applied. The change in the groove width of the substrate can be observed with an optical microscope or an electron microscope with the recording layer removed. The recording layer scratches the disc surface, peels off the protective layer and reflective layer with double-sided tape,
It can be removed by thoroughly washing off the dye with ethanol or the like.
【００２１】また、記録層を除去せずに水銀ランプの光
学顕微鏡により、焦点深度の長いＰＭＭＡレンズ等を対
物レンズに使用して、基板側から溝幅の変化を観察して
もよい。後述の実施例では、記録層を除去した後、電子
顕微鏡により観察し、記録部と未記録部の溝幅の変化の
割合を測定した。なお、後述の実施例では記録前後の溝
幅は、半値溝幅ではなく、電子顕微鏡で明るく見えるラ
ンド部（溝間部）の内側の暗く見える部分（溝部）の幅
を溝幅とした。Alternatively, without changing the recording layer, a change in groove width may be observed from the substrate side by using a PMMA lens having a long depth of focus as an objective lens with an optical microscope of a mercury lamp. In Examples described later, after the recording layer was removed, the recording layer was observed with an electron microscope to measure the rate of change in groove width between the recorded portion and the unrecorded portion. In Examples described later, the groove width before and after recording is not the half-value groove width, but the width of the dark portion (groove portion) inside the land portion (inter-groove portion) that looks bright with an electron microscope is the groove width.
【００２２】[0022]
【実施例】以下、本発明を実施例により更に詳細に説明
するが、本発明は、その要旨を越えない限り実施例に限
定されるものではない。 実施例１ 溝深さ１８０ｎｍ、溝幅０．３７μｍ（１．０μｍピッ
チ）、溝の壁の傾斜角が７５〜８０度で、Ｌｐ／Ｌ＝４
９％である（ＳＴＭによる測定）ポリカーボネート基板
上に下記構造式［１］EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to the examples as long as the gist thereof is not exceeded. Example 1 Groove depth 180 nm, groove width 0.37 μm (1.0 μm pitch), groove wall inclination angle is 75 to 80 degrees, and Lp / L = 4.
9% (measured by STM) The following structural formula [1] on a polycarbonate substrate
【００２３】[0023]
【化１】 Embedded image
【００２４】で示される含金属アゾ色素０.０３６ｇを
オクタフルオロペンタノール（ＯＦＰ）３ｇに溶解し、
８００ｒｐｍでスピンコートし、記録層とした。なお、
溝の壁の傾斜角が７５〜８０度と幅を持っているのは、
ＳＴＭの走査方向により、溝の左側の壁のθが７５度で
あり、右の壁のθが８０度となっているためである。こ
の色素の減量特性は主減量過程（主減量開始温度は２８
０℃）での総減量が２５.２％で、温度差が８.９℃で、
減量の傾きは２.８％/℃であった。なお、熱重量分析は
セイコー電子工業製の示差熱天秤（「ＳＳＣ５２００
Ｈ」シリーズ「ＴＧ−ＤＴＡ−３２０」）を用いて測定
した。0.036 g of the metal-containing azo dye represented by is dissolved in 3 g of octafluoropentanol (OFP),
Spin coating was performed at 800 rpm to form a recording layer. In addition,
The inclination angle of the wall of the groove has a width of 75 to 80 degrees,
This is because θ of the wall on the left side of the groove is 75 degrees and θ of the wall on the right side is 80 degrees depending on the scanning direction of the STM. The weight loss characteristic of this dye is the main weight loss process (main weight loss start temperature is 28
The total weight loss at 0 ° C is 25.2% and the temperature difference is 8.9 ° C.
The slope of weight loss was 2.8% / ° C. The thermogravimetric analysis is performed by a differential thermobalance (“SSC5200
H "series" TG-DTA-320 ").
【００２５】この記録層の上に金を６０ｎｍの厚さだけ
スパッタした。この状態でＳＴＭにより測定した記録層
の溝深さは、同じくＳＴＭで測定した基板の溝深さの５
７％であった（溝部膜厚は２１０ｎｍ）。その上にＵＶ
硬化樹脂（大日本インキ製「ＳＤー３１８」）を約３μ
ｍスピンコートして紫外線ランプで硬化してディスクを
作製した。このディスクを６８０ｎｍの半導体レーザー
評価機（ＮＡ＝０.６）で、線速３ｍ/ｓで溝上に記録し
たところ、再生パワー０.７ｍＷ、記録周波数３ＭＨ
ｚ、ｄｕｔｙ比３０％、記録パワー６ｍＷで記録したと
ころ、Ｃ／Ｎ５０ｄＢ、変調度４８％、クロストークは
３０ｄＢであり、良好な記録部が形成されていた。な
お、ここでのクロストークは、（グルーブ記録部再生Ｃ
／Ｎー隣接グルーブでの再生Ｃ／Ｎ）（ｄＢ）である。
このディスクの膜を除去し、ＳＥＭで記録部を観察した
ところ、記録部の溝幅が未記録記部よりも３３％広くな
っていた。なお、この色素層の６８０ｎｍでの屈折率
ｎ、消衰係数ｋはそれぞれ、２.４と０.１５であった。Gold was sputtered on the recording layer to a thickness of 60 nm. In this state, the groove depth of the recording layer measured by STM is 5 times the groove depth of the substrate similarly measured by STM.
It was 7% (the groove thickness was 210 nm). UV on it
About 3μ of cured resin (Dainippon Ink's SD-318)
A disk was prepared by spin-coating with m and curing with an ultraviolet lamp. This disc was recorded on a groove at a linear velocity of 3 m / s with a semiconductor laser evaluation machine of 680 nm (NA = 0.6). The reproduction power was 0.7 mW and the recording frequency was 3 MH.
When recording was performed with z, duty ratio of 30% and recording power of 6 mW, C / N was 50 dB, modulation degree was 48%, and crosstalk was 30 dB, and a good recording portion was formed. The crosstalk here is (groove recording section reproduction C
/ N-reproduction C / N in adjacent groove (dB).
When the recording portion was observed by SEM after removing the film of this disc, the groove width of the recording portion was 33% wider than that of the unrecorded portion. The refractive index n and the extinction coefficient k at 680 nm of this dye layer were 2.4 and 0.15, respectively.
【００２６】実施例２ 実施例１における色素量を０.０２ｇにした以外は全く
同様にしてディスクを作製した。記録層の溝深さが、Ｓ
ＴＭにより、膜のない状態の基板の溝深さの７０％であ
った（溝部の膜厚は１６０ｎｍ）。このディスクを実施
例１の評価機で記録パワーを９ｍＷにして同じ条件で溝
上で記録したところ、Ｃ／Ｎ４５ｄＢで、記録変調度が
４０％であり、クロストークは２５ｄＢであり、良好な
特性が得られた。実施例と同様にして記録部の基板をみ
たところ、溝幅が、未記録部よりも２３％広くなってい
た。Example 2 A disk was prepared in exactly the same manner as in Example 1 except that the amount of dye was 0.02 g. The groove depth of the recording layer is S
By TM, it was 70% of the groove depth of the substrate without the film (the film thickness of the groove part was 160 nm). When this disk was recorded on the groove under the same conditions with the recording power set to 9 mW by the evaluation machine of Example 1, the C / N was 45 dB, the recording modulation was 40%, the crosstalk was 25 dB, and good characteristics were obtained. Was obtained. When the substrate of the recording portion was examined in the same manner as in the example, the groove width was 23% wider than that of the unrecorded portion.
【００２７】実施例３ 実施例１において、溝深さ１８０ｎｍ、溝幅０.３３μ
ｍ（トラックピッチ０.７４μｍ）、溝の壁の傾斜角が
７７度〜８３度で、Ｌｐ／Ｌ＝４７％である案内溝を有
するポリカーボネート基板にかえ、反射膜を銀６０ｎｍ
にかえた以外は全く同様にしてディスクを作製した。こ
のディスクの記録層の溝深さは、基板の溝深さの５５％
であった。このディスクを、実施例１と全く同じ条件で
溝上で記録再生したところ、Ｃ／Ｎ５２ｄＢで、記録変
調度４５％、クロストークが３２ｄＢであった。実施例
１と同様にして記録部の基板の溝幅をＳＥＭでみたとこ
ろ、未記録部より４０％広くなっていた。Example 3 In Example 1, the groove depth was 180 nm and the groove width was 0.33 μm.
m (track pitch 0.74 μm), the inclination angle of the groove wall was 77 ° to 83 °, and the reflection film was replaced with a polycarbonate substrate having a guide groove with Lp / L = 47%, and the reflection film was silver with a thickness of 60 nm.
A disk was prepared in exactly the same manner except that the disk was changed. The groove depth of the recording layer of this disc is 55% of the groove depth of the substrate.
Met. When this disk was recorded / reproduced on the groove under exactly the same conditions as in Example 1, the C / N was 52 dB, the recording modulation was 45%, and the crosstalk was 32 dB. When the groove width of the substrate of the recorded portion was observed by SEM in the same manner as in Example 1, it was 40% wider than that of the unrecorded portion.
【００２８】比較例1 実施例１において、溝深さ９０ｎｍで溝幅０.４５μｍ
（トラックピッチ１μｍ）溝の壁の傾斜角が６０度で、
Ｌｐ／Ｌ＝４５％であるポリカーボネート基板にかえた
以外は全く同様にしてディスクを作製した。記録層の溝
深さは基板の溝深さの５０％であった。実施例１と同じ
記録をおこなったところ、Ｃ／Ｎ３０ｄＢで記録変調度
が１０％未満であった。記録部の基板の変形をしらべた
ところ、記録部の溝幅は未記録部の溝幅とほとんど変わ
らなかった。Comparative Example 1 In Example 1, the groove depth is 90 nm and the groove width is 0.45 μm.
(Track pitch 1 μm) The inclination angle of the groove wall is 60 degrees,
A disk was produced in exactly the same manner except that the polycarbonate substrate was Lp / L = 45%. The groove depth of the recording layer was 50% of the groove depth of the substrate. When the same recording as in Example 1 was performed, the recording modulation was less than 10% with C / N of 30 dB. When the deformation of the substrate of the recording portion was examined, the groove width of the recording portion was almost the same as the groove width of the unrecorded portion.
【００２９】実施例４ 実施例１で、Ｌｐ／Ｌ＝３０％の基板に変えた以外は全
く同様にしてディスクを作成し、６８０ｎｍの評価機で
同様にして評価したところ、記録パワー６ｍＷではＣ／
Ｎ３０ｄＢ、記録変調度１５％であり、記録パワー１３
ｍＷでＣ／Ｎ４５ｄＢ、記録変調度２５％であった。Example 4 A disk was prepared in the same manner as in Example 1 except that the substrate was changed to Lp / L = 30%, and the disk was evaluated in the same manner using an evaluation device of 680 nm. /
N30 dB, recording modulation degree 15%, recording power 13
The C / N was 45 dB at mW and the recording modulation was 25%.
【００３０】[0030]
【発明の効果】本発明により、溝幅の狭い溝上におい
て、高いＣ／Ｎ、大きな記録変調度を有する、波長６０
０〜７００ｎｍの短波長記録に好適な光記録媒体を得る
ことができる。According to the present invention, a wavelength 60 having a high C / N and a large recording modulation degree is provided on a groove having a narrow groove width.
An optical recording medium suitable for short wavelength recording of 0 to 700 nm can be obtained.
【図１】 溝の壁の傾斜角θを示す説明図FIG. 1 is an explanatory view showing an inclination angle θ of a groove wall.
【図２】 基板の溝間部の平坦部（Ｌｐ）と、溝の両脇
の壁の接線と平坦部を含む平面との交線間で表される平
坦部外挿部（Ｌ）との関係を説明する説明図FIG. 2 shows a flat portion (Lp) between a groove portion of a substrate and a flat portion extrapolation portion (L) represented by a line of intersection between a tangent line of walls on both sides of the groove and a plane including the flat portion. Explanatory diagram explaining the relationship
【図３】 色素の主減量過程、主減量過程の総重量、減
量の傾きを求める方法を説明するための示差熱天秤の模
式チャート図FIG. 3 is a schematic chart of a differential thermal balance for explaining a main weight loss process of a dye, a total weight of the main weight loss process, and a method for obtaining a slope of the weight loss.
【図４】 記録層の溝幅と反射率の相関関係を計算で求
めたグラフFIG. 4 is a graph obtained by calculating the correlation between the groove width of the recording layer and the reflectance.
Claims (9)
る案内溝を有する透明基板上に、少なくとも、有機色素
を含有する記録層、金属反射層、保護層の順に積層した
光記録媒体において、下記（イ）〜（ハ）の特徴を有す
る光記録媒体。 （イ）記録層が波長６００ｎｍ〜７００ｎｍのレーザー
光により光学的な変化を生じるものであること。 （ロ）基板の溝の壁の傾斜が７０〜８５度であること。 （ハ）基板の溝幅が０.３〜０.３７μｍであること。1. An optical recording medium in which at least a recording layer containing an organic dye, a metal reflective layer and a protective layer are laminated in this order on a transparent substrate having a guide groove having a track pitch of 0.7 to 1.0 μm. An optical recording medium having the following characteristics (a) to (c). (A) The recording layer has an optical change caused by laser light having a wavelength of 600 nm to 700 nm. (B) The inclination of the wall of the groove of the substrate is 70 to 85 degrees. (C) The groove width of the substrate is 0.3 to 0.37 μm.
光を照射することにより記録部を形成させたときに、基
板の溝幅が未記録部に対して２０〜４０％広くなること
を特徴とする請求項１に記載の光記録媒体。2. The groove width of the substrate is 20 to 40% wider than that of the unrecorded portion when the recording portion is formed by irradiating a laser beam having a wavelength of 600 nm to 700 nm. 1. The optical recording medium according to 1.
両脇の壁の接線と平坦部を含む平面との交線間で表され
る平坦部外挿部（Ｌ）の４５〜９５％である請求項１又
は２に記載の光記録媒体。3. A flat portion extrapolation portion (L), wherein a flat portion (Lp) of a groove portion of the substrate is represented by an intersection line between a tangent line of walls on both sides of the groove and a plane including the flat portion. The optical recording medium according to claim 1, which has a content of 45 to 95%.
〜７５％である請求項１〜３のいずれか１つに記載の光
記録媒体。4. The groove depth of the recording layer is 40 times the groove depth of the substrate.
The optical recording medium according to claim 1, wherein the optical recording medium has a content of ˜75%.
対する記録層単層の屈折率ｎが２〜３であり、消衰係数
ｋが０.０３〜０.１５である請求項１〜４のいずれか１
つに記載の光記録媒体。5. The refractive index n of the recording layer single layer for light in the wavelength region of recording / reproducing wavelength ± 5 nm is 2 to 3, and the extinction coefficient k is 0.03 to 0.15. One of
An optical recording medium according to item 1.
５万以上である吸収のうちで最も長波長側の吸収極大に
対応する、ディスク基板上に膜として形成された状態で
の吸収極大が、記録再生波長よりも４０〜６０ｎｍ短波
長側にあり、かつ、その吸収極大の吸光度に対して、記
録再生光波長での吸光度が５％〜１５％である請求項１
〜５のいずれか１つに記載の光記録媒体。6. Absorption of an organic dye in a state of being formed as a film on a disk substrate, which corresponds to the absorption maximum on the longest wavelength side among the absorptions having a molar absorption coefficient ε in solution of 50,000 or more. The maximum is on the short wavelength side of 40 to 60 nm from the recording / reproducing wavelength, and the absorbance at the recording / reproducing light wavelength is 5% to 15% with respect to the absorbance of the absorption maximum.
5. The optical recording medium according to any one of items 5 to 5.
〜６のいずれか１つに記載の光記録媒体。7. The metal reflective layer contains silver as a main component.
7. The optical recording medium according to any one of items 6 to 6.
〜７のいずれか１つに記載の光記録媒体。8. The protective layer is an ultraviolet curable resin.
The optical recording medium according to any one of items 1 to 7.
記録媒体に、記録部の基板の溝幅が未記録部の溝幅より
２０〜４０％広くなるように波長６００〜７００ｎｍの
レーザー光を照射することを特徴とする情報記録方法。9. The optical recording medium according to claim 1, wherein the groove width of the substrate of the recording portion is 20 to 40% wider than the groove width of the unrecorded portion, and the wavelength is 600 to 700 nm. An information recording method, which comprises irradiating a laser beam of.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP00464496A JP3543464B2 (en) | 1996-01-16 | 1996-01-16 | Optical recording medium and information recording method |
| US09/033,654 US6214519B1 (en) | 1995-08-22 | 1998-03-03 | Optical recording medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP00464496A JP3543464B2 (en) | 1996-01-16 | 1996-01-16 | Optical recording medium and information recording method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH09198714A true JPH09198714A (en) | 1997-07-31 |
| JP3543464B2 JP3543464B2 (en) | 2004-07-14 |
Family
ID=11589690
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP00464496A Expired - Lifetime JP3543464B2 (en) | 1995-08-22 | 1996-01-16 | Optical recording medium and information recording method |
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| Country | Link |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6225023B1 (en) * | 1996-11-20 | 2001-05-01 | Mitsubishi Chemical Corporation | Sulfonamide compound and method for its production, metal chelate compound employing the sulfonamide compound, and optical recording medium employing the metal chelate compound |
| US6933032B2 (en) | 2003-04-15 | 2005-08-23 | Ricoh Company, Ltd. | Write-once-read-many optical recording media and process for recording and reproducing information on the media |
| EP0849727B1 (en) * | 1996-12-18 | 2006-03-15 | Mitsubishi Chemical Corporation | Optical recording disk |
| KR100596894B1 (en) * | 1999-02-19 | 2006-07-04 | 다이요 유덴 가부시키가이샤 | Optical information medium and recording method thereof |
-
1996
- 1996-01-16 JP JP00464496A patent/JP3543464B2/en not_active Expired - Lifetime
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6225023B1 (en) * | 1996-11-20 | 2001-05-01 | Mitsubishi Chemical Corporation | Sulfonamide compound and method for its production, metal chelate compound employing the sulfonamide compound, and optical recording medium employing the metal chelate compound |
| US6284877B1 (en) | 1996-11-20 | 2001-09-04 | Mitsubishi Chemical Corporation | Sulfonamide compound and method for its production, metal chelate compound employing the sulfonamide compound, and optical recording medium employing the metal chelate compound |
| EP0849727B1 (en) * | 1996-12-18 | 2006-03-15 | Mitsubishi Chemical Corporation | Optical recording disk |
| KR100596894B1 (en) * | 1999-02-19 | 2006-07-04 | 다이요 유덴 가부시키가이샤 | Optical information medium and recording method thereof |
| US6933032B2 (en) | 2003-04-15 | 2005-08-23 | Ricoh Company, Ltd. | Write-once-read-many optical recording media and process for recording and reproducing information on the media |
| US7413788B2 (en) | 2003-04-15 | 2008-08-19 | Ricoh Company, Ltd. | Write-once-read-many optical recording media and process for recording and reproducing information on the media |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3543464B2 (en) | 2004-07-14 |
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