JP2903969B2 - Optical recording medium and recording / reproducing method using the same - Google Patents
Optical recording medium and recording / reproducing method using the sameInfo
- Publication number
- JP2903969B2 JP2903969B2 JP5275705A JP27570593A JP2903969B2 JP 2903969 B2 JP2903969 B2 JP 2903969B2 JP 5275705 A JP5275705 A JP 5275705A JP 27570593 A JP27570593 A JP 27570593A JP 2903969 B2 JP2903969 B2 JP 2903969B2
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- JP
- Japan
- Prior art keywords
- recording
- layer
- optical
- recording medium
- information recording
- 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.)
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- Optical Recording Or Reproduction (AREA)
Description
【0001】[0001]
【産業上の利用分野】本発明はレーザー光などの照射に
より、高速かつ高密度に情報を記録、再生、消去可能な
光学的記録用媒体およびこれを用いた記録再生方法に関
するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical recording medium capable of recording, reproducing, and erasing information at a high speed and at a high density by irradiation with a laser beam or the like, and a recording / reproducing method using the same.
【0002】[0002]
【従来の技術】近年、情報量の増大、記録・再生の高密
度・高速化の要求に応える記録媒体として、レーザー光
線を利用した光ディスクが開発されている。光ディスク
には、一度だけ記録が可能な追記型と、記録・消去が何
度でも可能な書換え型がある。書換え型光ディスクとし
ては、光磁気効果を利用した光磁気記録媒体や、可逆的
な結晶状態の変化を利用した相変化媒体が挙げられる。2. Description of the Related Art In recent years, an optical disk using a laser beam has been developed as a recording medium that meets the demand for an increase in the amount of information and a high density and high speed of recording and reproduction. Optical discs include a write-once type, which allows recording only once, and a rewritable type, which allows recording and erasing as many times as possible. Examples of the rewritable optical disk include a magneto-optical recording medium using a magneto-optical effect and a phase change medium using a reversible change in crystalline state.
【0003】相変化媒体は、外部磁界を必要とせず、レ
ーザー光のパワーを変調するだけで、記録・消去が可能
である。さらに、消去と再記録を単一ビームで同時に行
う1ビームオーバーライトが可能であるという利点を有
する。1ビームオーバーライト可能な相変化記録方式で
は、記録膜を非晶質化させることによって記録ビットを
形成し、結晶化させることによって消去を行う場合が一
般的である。[0003] The phase change medium does not require an external magnetic field, and can be recorded / erased only by modulating the power of laser light. Furthermore, there is an advantage that one-beam overwriting in which erasing and re-recording are performed simultaneously with a single beam is possible. In a phase change recording method capable of one-beam overwriting, it is general that a recording bit is formed by amorphizing a recording film and erasing is performed by crystallization.
【0004】このような、相変化記録方式に用いられる
記録層材料としては、カルコゲン系合金薄膜を用いるこ
とが多い。例えば、Ge−Te系、Ge−Te−Sb
系、In−Sb−Te系、Ge−Sn−Te系合金薄膜
等が挙げられる。なお、書換え型とほとんど同じ材料・
層構成を適用して、追記型の相変化媒体も実現できる。
この場合、その可逆性を利用しないのでより長期にわた
って情報を記録・保存でき、原理的にはほぼ半永久的な
保存が可能である。As a recording layer material used in such a phase change recording method, a chalcogen alloy thin film is often used. For example, Ge-Te system, Ge-Te-Sb
System, In-Sb-Te system, Ge-Sn-Te system alloy thin film and the like. In addition, almost the same materials and
By applying the layer structure, a write-once type phase change medium can be realized.
In this case, since the reversibility is not used, information can be recorded and stored for a longer period of time, and in principle, semi-permanent storage is possible.
【0005】追記型として相変化媒体を用いた場合、孔
あけ型と異なり記録ピット周辺にリムと呼ばれる盛り上
がりが生じないため信号品質に優れ、また記録層上部に
空隙が不要なためエアーサンドイッチ構造にする必要が
ないという利点がある。一般に、書換え型の相変化記録
媒体では、相異なる結晶状態を実現するために、2つの
異なるレーザー光パワーを用いる。この方式を、結晶化
された初期状態に非晶質ピットの記録および結晶化によ
る消去を行う場合を例にとって説明する。[0005] When a phase change medium is used as a write-once type, unlike a perforated type, there is no ridge called a rim around the recording pits, so that the signal quality is excellent. There is an advantage that there is no need to do this. Generally, in a rewritable phase change recording medium, two different laser beam powers are used to realize different crystal states. This method will be described by taking as an example a case in which amorphous pits are recorded and erased by crystallization in the crystallized initial state.
【0006】結晶化は、記録層の結晶化温度より十分高
く、融点よりは低い温度まで記録層を加熱することによ
ってなされる。この場合、冷却速度は結晶化が十分なさ
れる程度に遅くなるよう、記録層を誘電体層で挟んだ
り、ビームの移動方向に長い楕円形ビームを用いたりす
る。一方、非晶質化は記録層を融点より高い温度まで加
熱し、急冷することによって行う。この場合、上記誘電
体層は十分な冷却速度(過冷却速度)を得るための放熱
層としての機能も有する。[0006] Crystallization is performed by heating the recording layer to a temperature sufficiently higher than the crystallization temperature of the recording layer and lower than the melting point. In this case, the recording layer is sandwiched between dielectric layers, or an elliptical beam that is long in the beam moving direction is used so that the cooling rate becomes slow enough to sufficiently crystallize. On the other hand, the amorphization is performed by heating the recording layer to a temperature higher than the melting point and rapidly cooling the recording layer. In this case, the dielectric layer also has a function as a heat radiation layer for obtaining a sufficient cooling rate (supercooling rate).
【0007】さらに、上述のような、加熱・冷却過程に
おける記録層の溶融・体積変化に伴う変形や、プラスチ
ック基板への熱的ダメージを防いだり、湿気による記録
層の劣化を防止するためにも、上記誘電体層は重要であ
る。誘電体層の材質は、レーザー光に対して光学的に透
明であること、融点・軟化点・分解温度が高いこと、形
成が容易であること、適度な熱伝導性を有するなどの観
点から選定される。[0007] Further, in order to prevent the recording layer from being deformed due to melting and volume change in the heating / cooling process as described above, to prevent thermal damage to the plastic substrate, and to prevent deterioration of the recording layer due to moisture. The above dielectric layer is important. The material of the dielectric layer is selected from the viewpoint that it is optically transparent to laser light, has a high melting point, softening point, and decomposition temperature, is easy to form, and has an appropriate thermal conductivity. Is done.
【0008】[0008]
【発明が解決しようとする課題】ガウシアンビームに仮
定できるレーザーのビーム径は0.82×λ÷NA(λ
は波長、NAはレンズの開口数)で定義される。従って
高密度記録のためレーザーに600nm以下のような短
波長のものを用いると、ビームスポット径は小さくな
る。The beam diameter of a laser assumed to be a Gaussian beam is 0.82 × λ × NA (λ
Is the wavelength, and NA is the numerical aperture of the lens. Therefore, when a laser having a short wavelength such as 600 nm or less is used for high-density recording, the beam spot diameter becomes small.
【0009】相変化型光ディスクでは、記録層のアモル
ファスビットを結晶化温度でアニールし、結晶化させる
ことで記録の消去をおこなっているが、ビームスポット
径が小さい場合、記録層が結晶化温度以上に保たれる時
間が短くなり結晶化が上手くいかなくなるという問題点
があった。In a phase-change type optical disk, erasing of recording is performed by annealing and crystallizing amorphous bits in a recording layer at a crystallization temperature. However, when the beam spot diameter is small, the recording layer is over the crystallization temperature. The problem is that the time for which crystallization is not maintained is shortened and crystallization does not work well.
【0010】[0010]
【課題を解決するための手段】本発明者らは、相変化記
録層と第2の誘電体層の関係を改良することにより、記
録層が結晶化温度に保たれる時間を長くすることが可能
となり、結晶化温度の熱を十分な量与えることが出来、
特に600nm未満の短波長記録に適した光学記録用媒
体となることを見いだし、本発明に到達した。Means for Solving the Problems The present inventors have improved the relationship between the phase change recording layer and the second dielectric layer so as to increase the time during which the recording layer is kept at the crystallization temperature. It is possible to give a sufficient amount of heat at the crystallization temperature,
In particular, the present inventors have found that the medium is an optical recording medium suitable for short-wavelength recording of less than 600 nm, and arrived at the present invention.
【0011】本発明の要旨は、基板上に、第1の誘電体
層、相変化記録層、第2の誘電体層および反射層を順次
有する光学的情報記録用媒体であって、相変化記録層の
膜厚が20−50nmであり、第2の誘電体層は熱伝導
率が1×10-3pJ・μm-1・K-1・ns-1以下の材質
からなり、且つ膜厚が1nm以上10nm未満である、
波長600nm未満のレーザー光を用いて情報の記録再
生を行なうための光学的情報記録用媒体、およびこれを
用いて波長600nm未満のレーザーを用いて情報の記
録再生を行うことを特徴とする記録再生方法である。[0011] The gist of the present invention is an optical information recording medium having a first dielectric layer, a phase change recording layer, a second dielectric layer, and a reflective layer on a substrate in order. The thickness of the layer is 20-50 nm, the second dielectric layer is made of a material having a thermal conductivity of 1 × 10 −3 pJ · μm −1 · K −1 · ns −1 or less, and has a thickness of 1 nm or more and less than 10 nm,
An optical information recording medium for recording and reproducing information using a laser beam having a wavelength of less than 600 nm, and a recording and reproducing method for recording and reproducing information using a laser having a wavelength of less than 600 nm using the medium. Is the way.
【0012】相変化記録層はGeSbTe系、InSb
Te系等が好ましく用いられ、結晶化速度、非晶質化の
し易さ、結晶粒径、保存安定性等の改善のためSn,I
n,Ge,Pb,As,Se,Si,Bi,Au,T
i,Cu,Ag,Pt,Pd,Co,Ni等を加えても
よい。記録層の厚みが20nmより薄いと記録層自体に
よる熱保温性が少なくなり、また記録層の結晶化のため
の結晶核形成が抑えられ結晶化が抑制され、さらには十
分なコントラストが得られないという問題が生じる。The phase change recording layer is made of GeSbTe, InSb
Te-based or the like is preferably used, and Sn, I is used for improving the crystallization speed, the easiness of amorphization, the crystal grain size, the storage stability and the like.
n, Ge, Pb, As, Se, Si, Bi, Au, T
i, Cu, Ag, Pt, Pd, Co, Ni, etc. may be added. If the thickness of the recording layer is less than 20 nm, the heat insulation property of the recording layer itself is reduced, and the formation of crystal nuclei for crystallization of the recording layer is suppressed to suppress crystallization, and furthermore, a sufficient contrast cannot be obtained. The problem arises.
【0013】一方、50nmより厚くなると、オーバー
ライト時の物質移動が起こり易くなり記録層のクラック
が生じ易くなる。記録層の膜厚は20〜50nmが好ま
しい。記録層は、誘電体層で挟んで基板上に設けるが、
反射層、紫外線硬化樹脂からなる保護層等を設けてもよ
い。第1及び第2の誘電体層には、好ましくは硫化亜鉛
と二酸化ケイ素の混合物等の、透明で光学定数nが1.
9から2.4、kが0から0.05であり、熱膨張係数
が1.0×10-5以下の誘電体を用いることが好まし
い。On the other hand, when the thickness is more than 50 nm, mass transfer at the time of overwriting tends to occur and cracks in the recording layer tend to occur. The thickness of the recording layer is preferably 20 to 50 nm. The recording layer is provided on the substrate sandwiched between the dielectric layers,
A reflective layer, a protective layer made of an ultraviolet curable resin, or the like may be provided. The first and second dielectric layers are preferably transparent and have an optical constant n of 1.1, such as a mixture of zinc sulfide and silicon dioxide.
It is preferable to use a dielectric material having a coefficient of thermal expansion of not more than 9 to 2.4, k of 0 to 0.05, and 1.0 × 10 −5 or less.
【0014】誘電体層の膜厚は第2の誘電体層は10n
m未満とし、第1の誘電体層は好ましくは50nmから
250nmである。本発明においては第2の誘電体層の
厚さが10nm未満と、通常に比べて大変に薄くされて
いるのが特徴である。第2の誘電体層は少なくとも1n
m以上、製造上を考えれば5nm以上の厚さに設けるの
が良い。The thickness of the dielectric layer is 10 n for the second dielectric layer.
m and the first dielectric layer is preferably between 50 nm and 250 nm. The present invention is characterized in that the thickness of the second dielectric layer is less than 10 nm, which is much smaller than usual. The second dielectric layer has at least 1 n
m or more, and 5 nm or more in terms of manufacturing.
【0015】第2の誘電体層は熱伝導率が1×10-3p
J・μm-1・K-1・ns-1以下の材質のものを用いる。
このような厚さと熱伝導率にすることにより、第2の誘
電体層を伝ってすばやく記録層から熱を逃がすことで、
記録層が結晶化するための温度に保たれる幅を広くとる
ことが可能となり、十分に結晶化するための時間を稼ぐ
ことができる。The second dielectric layer has a thermal conductivity of 1 × 10 −3 p.
A material having a material of J · μm -1 · K -1 · ns -1 or less is used.
With such a thickness and thermal conductivity, heat can be quickly released from the recording layer through the second dielectric layer,
It is possible to increase the width of the recording layer maintained at the temperature for crystallization, and it is possible to increase the time for sufficiently crystallization.
【0016】本発明における記録媒体の基板としては、
ガラス、プラスチック、ガラス上に光硬化性樹脂を設け
たもの等のいずれであってもよいが、本発明に用いた誘
電体層は耐熱性に優れ、基板の熱的変形防止効果がある
ため、現在光ディスク用基板として一般的に使用されて
いるポリカーボネート樹脂基板を使用することが可能で
ある。The substrate of the recording medium in the present invention includes:
Glass, plastic, may be any of those provided with a photocurable resin on the glass, etc., since the dielectric layer used in the present invention has excellent heat resistance and has an effect of preventing thermal deformation of the substrate, It is possible to use a polycarbonate resin substrate generally used as an optical disk substrate at present.
【0017】反射層は、AlおよびAl合金、Au、A
g等の、熱伝導性の高い物質を用いることが好ましく、
その厚みは通常100〜200nmの範囲に選ばれる。
記録層、誘電体層、反射層はスパッタリング法などによ
って形成される。記録膜用ターゲット、誘電体膜用ター
ゲット、必要な場合には反射層材料用ターゲットを同一
真空チャンバー内に設置したインライン装置で膜形成を
行うことが各層間の酸化や汚染を防ぐ点で望ましい。ま
た、生産性の面からもすぐれている。The reflection layer is made of Al and an Al alloy, Au, A
g, it is preferable to use a substance having high thermal conductivity,
The thickness is usually selected in the range of 100 to 200 nm.
The recording layer, the dielectric layer, and the reflection layer are formed by a sputtering method or the like. It is desirable to form a film using an in-line apparatus in which a target for a recording film, a target for a dielectric film, and if necessary, a target for a reflective layer material are installed in the same vacuum chamber, from the viewpoint of preventing oxidation and contamination between layers. It is also excellent in productivity.
【0018】本発明に記載されている熱伝導率は、物質
のバルクでの値ではなく、薄膜の熱伝導率である。薄膜
の熱伝導率測定法には、J.C.Lambropoul
os,et.al.,J.Appl.Phys.,6
6,4230(1989)、I.Hatta,et.a
l.,Rev.Sci.Instrum.,56,16
43(1985)や、M.Horie,et.al.,
MitsubishiKasei R&D Revie
w,4(2),68(1990)等に示されている。具
体的には光交流励起法による熱伝導率測定装置を用いれ
ば良い。The thermal conductivity described in the present invention is not a value in the bulk of a substance, but a thermal conductivity of a thin film. Methods for measuring the thermal conductivity of thin films are described in C. Lambropoul
os, et. al. , J. et al. Appl. Phys. , 6
6,4230 (1989); Hatta, et. a
l. Rev., Rev .. Sci. Instrum. , 56,16
43 (1985); Horie, et. al. ,
MitsubishiKasei R & D Review
w, 4 (2), 68 (1990) and the like. Specifically, a thermal conductivity measuring device using a photo-ac excitation method may be used.
【0019】[0019]
【実施例】以下実施例をもって本発明を詳細に説明す
る。 実施例1 ポリカーボネート樹脂基板上に(ZnS)80(Si
O2)20(数字は成分割合を示し単位はmol%)の組成、
波長488nmの場合の光学定数がn=2.2、k=0
の第1の誘電体膜を155nm、Ge2Sb2Te5(組
成は比率で示した)記録膜を30nm、(ZnS)
80(SiO2)20の組成、波長488nmの場合の光学
定数がn=2.2、k=0の第2の誘電体膜(熱伝導率
3.5×10-4pJ・μm-1・K-1・ns-1)を5n
m、Al合金反射膜を200nm、スパッタリング法に
より順に形成した。さらに反射層の上部に紫外線硬化樹
脂層を設けた。The present invention will be described in detail with reference to the following examples. Example 1 (ZnS) 80 (Si
O 2 ) 20 (the numbers indicate the component ratio and the unit is mol%),
When the wavelength is 488 nm, the optical constants are n = 2.2 and k = 0.
155nm the first dielectric film, Ge 2 Sb 2 Te 5 (composition expressed as a percentage) 30 nm recording layer, (ZnS)
A second dielectric film having a composition of 80 (SiO 2 ) 20 and an optical constant of n = 2.2 and k = 0 at a wavelength of 488 nm (thermal conductivity 3.5 × 10 −4 pJ · μm −1. K -1 · ns -1 ) is 5n
m, an Al alloy reflective film was formed in order of 200 nm by a sputtering method. Further, an ultraviolet curable resin layer was provided on the reflective layer.
【0020】上記のように作成したディスクの記録層は
アモルファス状態であるので、Arレーザーで結晶化さ
せ初期化を行った後、波長488nmのレーザーピック
アップを用いた評価装置でディスクの動特性を評価し
た。線速度10m/secで記録パワー12mW、消去
パワー6mWで記録周波数8.58MHz、パルス幅3
8nsecの信号を記録した時のC/N比、および消去
パワーをDC照射した時の消去比はそれぞれ56dB、
28dBであった。さらに、消去比20dB以上の消去
パワーマージンは4mWであった。Since the recording layer of the disk prepared as described above is in an amorphous state, the disk is crystallized with an Ar laser and initialized, and then the dynamic characteristics of the disk are evaluated by an evaluation device using a laser pickup having a wavelength of 488 nm. did. A recording power of 12 mW at a linear velocity of 10 m / sec, a recording frequency of 8.58 MHz at an erasing power of 6 mW, and a pulse width of 3
The C / N ratio when a signal of 8 nsec was recorded and the erasing ratio when DC power was applied to the erasing power were 56 dB, respectively.
It was 28 dB. Further, the erase power margin at an erase ratio of 20 dB or more was 4 mW.
【0021】[0021]
【0022】[0022]
【0023】比較例1 ポリカーボネート樹脂基板上に(ZnS)80(Si
O2)20の組成、波長488nmの場合の光学定数がn
=2.2、k=0の第1の誘電体膜を160nm、Ge
2Sb2Te5記録膜を20nm、(ZnS)80(Si
O2)20の組成、波長488nmの場合の光学定数がn
=2.2、k=0の第2の誘電体膜(熱伝導率3.5×
10-4pJ・μm-1・K-1・ns-1)を20nm、Al
合金反射膜を200nm、スパッタリング法により順に
形成した。Comparative Example 1 (ZnS) 80 (Si
The composition of O 2 ) 20 has an optical constant of n when the wavelength is 488 nm.
= 2.2, k = 0, 160 nm, Ge
The 2 Sb 2 Te 5 recording film is made of 20 nm, (ZnS) 80 (Si
The composition of O 2 ) 20 has an optical constant of n when the wavelength is 488 nm.
= 2.2, k = 0 (second thermal conductivity 3.5 ×
10 −4 pJ · μm −1 · K −1 · ns −1 ) to 20 nm, Al
An alloy reflective film was formed in order of 200 nm by a sputtering method.
【0024】さらに反射層の上部に紫外線硬化樹脂層を
設けた。上記のように作成したディスクの記録層はアモ
ルファス状態であるので、Arレーザーで結晶化させ初
期化を行った後、波長488nmのレーザーピックアッ
プを用いた評価装置でディスクの動特性を評価した。線
速度10m/secで記録パワー8mW、消去パワー4
mWで記録周波数8.58MHz、パルス幅38nse
cの信号を記録した時のC/N比、および消去パワーを
DC照射した時の消去比はそれぞれ56dB、20dB
であった。さらに、消去比20dB以上の消去パワーマ
ージンは0.3mWであった。参考例1〜3ポリカーボ
ネート樹脂基板上に、(ZnS)80(SiO2 )20の組
成(単位はmol %;熱伝導率3.5×10-4[ pJ/μ
m/K/ns] )の第1の誘電体膜を110nm、表−
1に示す厚さのGe2 Sb2 Te5 記録膜、(ZnS)
80(SiO2 )20の組成(熱伝導率3.5×10-4[ p
J/μm/K/ns] )で表−1に示す厚さの第2の誘
電体膜、Al合金反射膜を200nmを、スパッタリン
グ法により順に形成した。さらに反射層の上部に紫外線
硬化樹脂層を設けた。上記のように作成したディスクの
記録層はアモルファス状態であるので、波長810nm
のLDを光源とするバルクイレーザにより結晶化させ初
期化を行った後、波長780nm(NA0.55)のレ
ーザーピックアップを用いた評価装置でディスクの動特
性を評価した。線速度10m/secで表−1に示す記
録パワー及び消去パワーで記録周波数4MHz、dut
y50%の信号を記録した時のC/N比、及び消去比2
0dB以上の消去パワーマージンを表−1に示す。Further, an ultraviolet curable resin layer was provided on the reflective layer. Since the recording layer of the disk prepared as described above was in an amorphous state, the disk was crystallized with an Ar laser and initialized, and then the dynamic characteristics of the disk were evaluated by an evaluation device using a laser pickup having a wavelength of 488 nm. At a linear velocity of 10 m / sec, a recording power of 8 mW and an erasing power of 4
8.58 MHz recording frequency and 38 ns pulse width at mW
The C / N ratio when the signal of c was recorded and the erasing ratio when DC power was applied to the erasing power were 56 dB and 20 dB, respectively.
Met. Further, the erase power margin at an erase ratio of 20 dB or more was 0.3 mW. Reference Examples 1 to 3 Composition of (ZnS) 80 (SiO 2 ) 20 (unit: mol%; thermal conductivity: 3.5 × 10 −4 [pJ / μ) on a polycarbonate resin substrate
m / K / ns]) of the first dielectric film of 110 nm,
Ge 2 Sb 2 Te 5 recording film having a thickness shown in FIG. 1, (ZnS)
80 (SiO 2 ) 20 composition (thermal conductivity 3.5 × 10 -4 [p
J / μm / K / ns]), and a 200 nm thick second dielectric film and an Al alloy reflective film having the thicknesses shown in Table 1 were sequentially formed by sputtering. Further, an ultraviolet curable resin layer was provided on the reflective layer. Since the recording layer of the disk created as described above is in an amorphous state, the wavelength is 810 nm.
After performing crystallization and initialization with a bulk eraser using the LD as a light source, the dynamic characteristics of the disk were evaluated by an evaluation apparatus using a laser pickup having a wavelength of 780 nm (NA 0.55). At a linear velocity of 10 m / sec, the recording power and erasing power shown in Table 1 were used at a recording frequency of 4 MHz and a dut.
C / N ratio when a signal of y50% is recorded, and erase ratio 2
Table 1 shows the erase power margin of 0 dB or more.
【表1】 表−1より、750〜900nm程度での波長での記録
再生においては、本願で規定する膜厚や熱伝導率の範囲
にあってもそうでなくても、消去マージンに大きな差が
ないことが分かる。むしろ、膜厚や熱伝導率が本願で規
定する範囲と一致する参考例3においては、記録や消去
パワーが大きく感度が悪いことが分かる[Table 1] From Table 1, it can be seen that in recording / reproducing at a wavelength of about 750 to 900 nm, there is no large difference in the erasing margin regardless of whether it is within the range of the film thickness and thermal conductivity specified in the present application. I understand. Rather, in Reference Example 3 in which the film thickness and the thermal conductivity match the ranges specified in the present application, it can be seen that the recording and erasing powers are large and the sensitivity is poor.
【0025】[0025]
【発明の効果】本発明の光学的情報記録用媒体は、特に
レーザー波長600nm以下の光源を用いて、感度良く
C/N比および消去比の良い記録再生特性を得ることが
できる。According to the optical information recording medium of the present invention, a recording / reproducing characteristic having a high C / N ratio and a good erasing ratio can be obtained with high sensitivity, particularly by using a light source having a laser wavelength of 600 nm or less.
フロントページの続き (51)Int.Cl.6 識別記号 FI G11B 7/24 538 G11B 7/24 538C (72)発明者 堀江 通和 神奈川県横浜市緑区鴨志田町1000番地 三菱化成株式会社総合研究所内 (56)参考文献 特開 平4−263133(JP,A) 特開 平3−241539(JP,A) (58)調査した分野(Int.Cl.6,DB名) G11B 7/24 535 G11B 7/24 538 Continuation of the front page (51) Int.Cl. 6 Identification code FI G11B 7/24 538 G11B 7/24 538C (72) Inventor Horie Tatsukazu 1000 Kamoshita-cho, Midori-ku, Yokohama-shi, Kanagawa Prefecture Mitsubishi Chemical Corporation Research Institute (56) References JP-A-4-263133 (JP, A) JP-A-3-241539 (JP, A) (58) Fields investigated (Int. Cl. 6 , DB name) G11B 7/24 535 G11B 7 / 24 538
Claims (6)
層、第2の誘電体層および反射層を順次有する光学的情
報記録用媒体であって、相変化記録層の膜厚が20−5
0nmであり、第2の誘電体層は熱伝導率が1×10-3
pJ・μm-1・K-1・ns-1以下の材質からなり、且つ
膜厚が1nm以上10nm未満である、波長600nm
未満のレーザー光を用いて情報の記録再生を行なうため
の光学的情報記録用媒体。1. An optical information recording medium having a first dielectric layer, a phase change recording layer, a second dielectric layer, and a reflective layer on a substrate, wherein the thickness of the phase change recording layer is Is 20-5
0 nm, and the second dielectric layer has a thermal conductivity of 1 × 10 −3.
a wavelength of 600 nm, which is made of a material of pJ · μm -1 · K -1 · ns -1 or less and has a film thickness of 1 nm or more and less than 10 nm.
For recording and reproducing information using laser light less than
The optical information recording medium.
nSbTe系である請求項1に記載の光学的情報記録用
媒体。 2. A phase change recording layer comprising a GeSbTe-based or I
2. The optical information recording device according to claim 1, wherein the optical information recording device is an nSbTe system.
Medium.
二酸化ケイ素との混合物の組成を有する請求項1又は23. The composition according to claim 1, which has a composition of a mixture with silicon dioxide.
に記載の光学的情報記録用媒体。2. The optical information recording medium according to claim 1.
が1.9−2.4であり、kが0−0.05である誘電Is 1.9-2.4 and k is 0-0.05.
体からなる請求項1乃至3のいずれか1つに記載の光学An optical device according to any one of claims 1 to 3, wherein the optical device comprises a body.
的情報記録用媒体。Information recording medium.
る請求項1乃至4のいずれか1つに記載の光学的情報記The optical information recording device according to any one of claims 1 to 4,
録用媒体。Recording medium.
光学的情報記録用媒体に、波長600nm未満のレーザLaser with wavelength less than 600nm for optical information recording medium
ー光を用いて情報の記録再生を行うことを特徴とする記-Recording and reproduction of information using light
録再生方法。Recording and playback method.
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JP5275705A JP2903969B2 (en) | 1993-11-04 | 1993-11-04 | Optical recording medium and recording / reproducing method using the same |
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JP5275705A JP2903969B2 (en) | 1993-11-04 | 1993-11-04 | Optical recording medium and recording / reproducing method using the same |
Publications (2)
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JPH07130001A JPH07130001A (en) | 1995-05-19 |
JP2903969B2 true JP2903969B2 (en) | 1999-06-14 |
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JP5275705A Expired - Lifetime JP2903969B2 (en) | 1993-11-04 | 1993-11-04 | Optical recording medium and recording / reproducing method using the same |
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WO2003098619A1 (en) * | 2002-04-22 | 2003-11-27 | Tdk Corporation | Optical recording medium |
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1993
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