JP2559871B2 - Optical recording medium - Google Patents
Optical recording mediumInfo
- Publication number
- JP2559871B2 JP2559871B2 JP2029432A JP2943290A JP2559871B2 JP 2559871 B2 JP2559871 B2 JP 2559871B2 JP 2029432 A JP2029432 A JP 2029432A JP 2943290 A JP2943290 A JP 2943290A JP 2559871 B2 JP2559871 B2 JP 2559871B2
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- JP
- Japan
- Prior art keywords
- layer
- optical recording
- film
- magneto
- recording medium
- 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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Description
【発明の詳細な説明】 ＜利用分野＞ 本発明はレーザー等の光により、情報の記録、再生、
消去などを行なう光記録媒体に関する。更に詳細には、
金属反射層を有する光記録媒体に関し、中でも記録層が
膜面に垂直な方向に磁化容易方向を有した金属薄膜より
なる、光熱磁気効果により情報を記録し、磁気光学効果
により再生する光磁気記録媒体に特に好ましく適用でき
るものである。DETAILED DESCRIPTION OF THE INVENTION <Field of Use> The present invention uses information from a laser or the like to record or reproduce information.
The present invention relates to an optical recording medium that erases data. More specifically,
Regarding an optical recording medium having a metal reflective layer, in particular, a magneto-optical recording in which information is recorded by a photothermomagnetic effect and reproduced by a magnetooptical effect, in which the recording layer is composed of a metal thin film having an easy magnetization direction in a direction perpendicular to a film surface. It is particularly preferably applicable to a medium.
＜従来技術＞ 光記録媒体は高密度・大容量の情報記録媒体として種
々の研究開発が行なわれている。特に情報の消去可能な
光磁気記録媒体は応用分野が広く種々の材料・システム
が発表されており、その実用化が待望されている。<Prior Art> Various researches and developments have been made on optical recording media as information recording media of high density and large capacity. In particular, a magneto-optical recording medium capable of erasing information has a wide range of application fields, and various materials and systems have been announced, and their practical application is expected.
上述の光磁気記録材料としては、例えば、特開昭52−
31703号公報記載のFeTb、特開昭56−126907号公報記載
のFeTbGd、特開昭58−73746号公報記載のFeTbCo、FeCoD
y、特開昭61−165846号公報記載のFeNd等既に多くの提
案がある。しかし、これらの情報の消去可能な光磁気記
録媒体の実用化には、記録、再生特性のより一層の向上
が必要である。Examples of the above-mentioned magneto-optical recording material include, for example, JP-A-52-
FeTb described in JP 31703, FeTbGd described in JP-A-56-126907, FeTbCo described in JP-A-58-73746, FeCoD
y, many proposals such as FeNd described in JP-A-61-165846 have already been made. However, in order to put these magneto-optical recording media into which information can be erased into practical use, it is necessary to further improve the recording and reproducing characteristics.
これに対し、光磁気記録層上、もしくはその上に誘電
体層を介して金属反射層を設ける方法が提案されてい
る。この方法はカー効果とファラデー効果の併用により
高いC/N比（再生出力とノイズの比率）を得る点で優れ
ている。従来この金属反射層として、Alを用いたもの
（特開昭58−83346号公報、特開昭59−132434号公
報）、Cuを用いたもの（特開昭59−8150号公報）、Al系
合金を用いたもの（特開昭62−137743号公報）、ステン
レスを用いたもの（特開昭59−171054号公報）、Teを用
いたもの（特開昭62−52744号公報）、非晶質金属膜を
用いたもの（特開昭61−57053号公報）等が提案されて
いる。しかしながら、高反射率のAl,Cu等を用いた場合
いはその高熱伝導性のため記録感度が大幅に低下し、一
方比較的熱伝導性の低いステンレス、Teを用いた場合に
は記録感度は向上するが反射率が低いため、十分なC/N
比が得られないという欠点を有する。On the other hand, a method of providing a metal reflective layer on the magneto-optical recording layer or on the magneto-optical recording layer via a dielectric layer has been proposed. This method is excellent in that a high C / N ratio (ratio of reproduction output and noise) is obtained by using the Kerr effect and the Faraday effect together. Conventionally, Al is used as the metal reflection layer (Japanese Patent Laid-Open No. 58-83346, Japanese Patent Laid-Open No. 59-132434), Cu (Japanese Patent Laid-Open No. 59-8150), Al-based. Those using alloys (JP-A-62-137743), those using stainless steel (JP-A-59-171054), those using Te (JP-A-62-52744), amorphous The one using a metallic film (Japanese Patent Laid-Open No. 61-57053) has been proposed. However, when using Al, Cu, etc. with high reflectance, the recording sensitivity is significantly reduced due to its high thermal conductivity, while when using stainless steel and Te, which have relatively low thermal conductivity, the recording sensitivity is Improves but has low reflectance, so sufficient C / N
It has the drawback that no ratio can be obtained.
これに対し、特開昭61−194664号公報，特開昭64−49
38号公報，特開昭64−86348号公報，特開昭64−86349号
公報ではAlNi、AlTa、AlPt、AlMo、AlCr、AlZr、AlV合
金が提案されている。これらの合金膜はAlの高反射率を
ある程度維持しながら、又は多少の反射率の低下がある
もののAlよりも熱伝導率を低下せしめることに成功して
おり、前述の欠点を解消し、光磁気記録媒体の特性向上
に効果が期待される。On the other hand, JP-A-61-194664 and JP-A-64-49
38, JP-A-64-86348, and JP-A-64-86349 propose AlNi, AlTa, AlPt, AlMo, AlCr, AlZr, and AlV alloys. These alloy films have been able to maintain the high reflectance of Al to some extent, or have succeeded in lowering the thermal conductivity compared to Al, although there is some reduction in reflectance, eliminating the aforementioned drawbacks, and The effect is expected to improve the characteristics of the magnetic recording medium.
しかしながら、実用化を目指してスパッタリング法で
前述のAl合金膜を形成するには、均一な組成の合金ター
ゲットの得難いことが大きな欠点となる。すなわち、真
空熔解で前述のAl合金を形成するには、Alと添加元素と
の融点差の非常に大きいことが障害となる。すなわちAl
の660℃の融点に対して、前記の添加元素はNiの1453℃
を最低として、Taの2977℃の範囲の融点を有する。この
理由等により、前述のAl合金系では均一に混合できる添
加元素の量は非常に少く、たとえ熱伝導率の低下に効果
のあるだけの量を添加しても、偏析の多い不均一な組成
分布を有するターゲットしか得られない。すなわち、前
述した従来のAl合金系の熱伝導率低下の効果の発現は、
添加元素の高融点に由来していると考えられ、本質的に
組成が均一な良好な合金ターゲットを得ることとは相矛
盾しており、工業化面で大きな問題を有している。However, in order to form the above-mentioned Al alloy film by the sputtering method for practical use, it is a major drawback that it is difficult to obtain an alloy target having a uniform composition. That is, in forming the above-mentioned Al alloy by vacuum melting, an extremely large difference in melting point between Al and the additional element becomes an obstacle. Ie Al
For the melting point of 660 ℃ of Ni, the above-mentioned additional elements are 1453 ℃ of Ni
With a minimum melting point of Ta in the range of 2977 ° C. For this reason, the amount of additive elements that can be uniformly mixed in the above-mentioned Al alloy system is very small, and even if added in an amount that is effective in reducing the thermal conductivity, there is a large amount of segregation and non-uniform composition. Only targets with a distribution can be obtained. That is, the expression of the effect of reducing the thermal conductivity of the conventional Al alloy system described above,
It is considered to be derived from the high melting point of the additive element, which is inconsistent with obtaining a good alloy target having a substantially uniform composition, and has a serious problem in industrialization.
また、耐久性に対する要求は、依然として大きな問題
である。Also, the demand for durability remains a major problem.
＜発明の目的＞ 本発明はかかる現状に鑑みなされたもので、合金ター
ゲットの作成が容易で大量生産に適した新規なAl合金系
反射膜により高高度で高C/N比で、更に耐久性にすぐれ
た光記録媒体を提供することを目的としたものである。<Purpose of the invention> The present invention has been made in view of the above circumstances, and a new Al alloy-based reflective film which is easy to produce an alloy target and suitable for mass production has a high altitude, a high C / N ratio, and further durability. The object of the present invention is to provide an excellent optical recording medium.
＜発明の構成及び作用＞ 即ち本発明は、金属反射層を有する光記録媒体におい
て、該金属反射層がAlにAuを0.5〜15at％,Tiを0.3〜5.0
at％含有せしめたAlAuTi合金からなることを特徴とする
光記録媒体である。<Structure and Action of the Invention> That is, the present invention provides an optical recording medium having a metal reflective layer, wherein the metal reflective layer has Al of 0.5 to 15 at% and Ti of 0.3 to 5.0.
An optical recording medium characterized by comprising an AlAuTi alloy containing at%.
以下本発明の詳細を発明に到った経過と共に説明す
る。The details of the present invention will be described below along with the progress of the invention.
本発明者らは、低熱伝導率のAl合金を目的にAlに添加
する種々の元素を、特に均一な合金ターゲットの得やす
い低融点の金属に着目して検討し、融点1063℃のAuがAl
合金の熱伝導率の低下に顕著な効果を有することを見い
出した。従来は高融点及び／又はそれ自体（単体金属と
して）熱伝導率の小さい添加金属が検討されて来たが、
低融点であり、Alよりも高熱伝導率のAuを添加したAlAu
合金膜が低熱伝導率を示したことは驚くべきことであっ
た。そして、この理由がAl2Au金属間化合物の生成に由
来することが判明した。例えば、Alターゲット上にTa、
Zr又はTiの小片を置いてスパッタリングで得た従来の合
金膜のＸ線回折では、いずれも面心立方結晶格子（fc
c）Alの（1,1,1）面からの回折ピークのみが観察された
が、本発明のAlAu膜ではfccAlの回折ピークは消滅し、A
l2Au金属間化合物の（1,1,1）面と（2,2,0）面に帰属さ
れる面間隔3.49Åと2.14Åの回折ピークが観察され、Al
2Au金属間化合物が形成されていることが確認された。
そしてこのAl2Au金属間化合物が熱伝導率の低下に寄与
していると考えられる。The present inventors have studied various elements to be added to Al for the purpose of an Al alloy having a low thermal conductivity, particularly focusing on a metal having a low melting point that is easy to obtain a uniform alloy target, and Au having a melting point of 1063 ° C. is Al.
It has been found that it has a significant effect on the reduction of the thermal conductivity of the alloy. Conventionally, an additive metal having a high melting point and / or a small thermal conductivity per se (as a single metal) has been studied,
AlAu with a low melting point and added with Au having a higher thermal conductivity than Al
It was surprising that the alloy film showed low thermal conductivity. Then, it was found that this reason was derived from the formation of the Al 2 Au intermetallic compound. For example, Ta on an Al target,
In the X-ray diffraction of the conventional alloy film obtained by sputtering with a small piece of Zr or Ti, the face-centered cubic crystal lattice (fc
c) Only the diffraction peak from the (1,1,1) plane of Al was observed, but the diffraction peak of fccAl disappeared in the AlAu film of the present invention.
Diffraction peaks with interplanar spacings of 3.49Å and 2.14Å attributed to the (1,1,1) and (2,2,0) planes of the l 2 Au intermetallic compound were observed.
It was confirmed that a 2 Au intermetallic compound was formed.
It is considered that this Al 2 Au intermetallic compound contributes to the decrease in thermal conductivity.
Auの添加量が0.5at％より少いと、かかる熱伝導低下
の効果は小さく、逆に20at％より多いとAlAu合金膜の反
射率の低下が大きく不都合である。すなわち、AlAu合金
膜中にAl2Au金属間化合物が生成することが必要である
が、膜全体がAl2Au金属間化合物となるのは好ましくな
く、本発明のAlAu合金膜はAl2Au金属間化合物を良好な
特性が得られる範囲で含むことが好ましい。If the amount of Au added is less than 0.5 at%, the effect of lowering the thermal conductivity is small, and if it is more than 20 at%, the reflectance of the AlAu alloy film is greatly decreased, which is inconvenient. That is, it is necessary that the Al 2 Au intermetallic compound is generated in the AlAu alloy film, but it is not preferable that the entire film becomes the Al 2 Au intermetallic compound, and the AlAu alloy film of the present invention is formed of the Al 2 Au metal. It is preferable to include an intercalation compound in a range where good characteristics can be obtained.
単体金属としてはともに高反射率であるとAlとAuを合
金膜にした時の反射率の低下は、同様にAl2Au金属間化
合物の生成により説明される。AlAu合金膜の反射率の低
下を最小限に抑えること、かつAuは高価であることか
ら、Auの添加量は最小限にとどめるべきである。かかる
目的で本発明者らはTiを補助的に添加することを試み、
その効果を確認した。Tiの添加量は5.0at％以内にとど
めるべきであり、これより多いとAlAuTi膜の反射率が低
下し、また均一なAlAuTi合金ターゲットの作製が困難と
なる。5.0at％以内では光磁気記録再生装置で使用され
る半導体レーザーの波長である830nmでの反応率の低下
は、AlAu膜の86〜82％の反射率より２％以内の低下幅に
とどまる。0.3at％より少いと、Auを節約したことによ
る熱伝導率の上昇分を補うことができない。The decrease in the reflectance when Al and Au are formed into an alloy film is also explained by the formation of Al 2 Au intermetallic compound when both the single metals have high reflectance. The amount of Au added should be kept to a minimum because the decrease in reflectance of the AlAu alloy film is minimized and Au is expensive. For this purpose, the present inventors attempted to supplementarily add Ti,
I confirmed the effect. The amount of Ti added should be kept within 5.0 at%, and if it is more than this, the reflectance of the AlAuTi film is lowered, and it becomes difficult to produce a uniform AlAuTi alloy target. Within 5.0 at%, the decrease in the reaction rate at 830 nm, which is the wavelength of the semiconductor laser used in the magneto-optical recording / reproducing apparatus, is within 2% of the reflectivity of the AlAu film, which is 86 to 82%. If it is less than 0.3 at%, the increase in thermal conductivity due to the saving of Au cannot be compensated.
さらに、AuとTiの合計の含有量は、記録感度向上効果
が大きく、且つ反射膜の反射率の低下によるC/Nの低下
が軽微である1.0〜15at％の範囲がより好ましい。Further, the total content of Au and Ti is more preferably in the range of 1.0 to 15 at% where the effect of improving the recording sensitivity is large and the decrease in C / N due to the decrease in the reflectance of the reflective film is slight.
なお、Al89Au8Ti3（添字は組成（at％）を示す）組成
の1000Å膜厚の合金膜においても電子線回折において、
Alに混りAl2Auの回折リングが認められた。また透過電
子顕微鏡により該合金膜は数10Åから100Å以内のきわ
めて微細な結晶の均一な集合体であることが判った。比
較試料として観察した膜厚1000ÅのAl膜,Al99Ti1（添字
は組成（at％）を示す）合金膜では結晶サイズが300Å
から1000Åの間の種々の大きさのものが観察された。本
発明のAlAuTi合金反射層を有する光記憶媒体の高耐久性
は、不活性なAuの添加とともに、かかる膜組成にも由来
すると考えられる。In addition, even in the case of an alloy film having a composition of Al 89 Au 8 Ti 3 (subscript indicates composition (at%)) with a film thickness of 1000 Å,
A diffraction ring of Al 2 Au mixed with Al was recognized. Further, it was found by a transmission electron microscope that the alloy film was a uniform aggregate of extremely fine crystals within several tens of liters to 100 liters. The Al film with a thickness of 1000Å and Al 99 Ti 1 (subscript indicates composition (at%)) alloy film observed as a comparative sample had a crystal size of 300Å
Various sizes between 1 and 1000Å were observed. It is considered that the high durability of the optical storage medium having the AlAuTi alloy reflective layer of the present invention is derived from the film composition as well as the addition of inert Au.
なお、以上の本発明の金属反射膜には経時安定性を更
に改善するために、Cr、Nb、Reなどの他の元素を少量添
加してもよい。この金属反射層の膜厚は200〜2000Åが
好ましく、300〜800Åが更に好ましい。厚すぎる場合に
は感度が低下し、薄すぎる場合には反射膜の反射率が低
下しC/Nが劣化する。In addition, in order to further improve the stability over time, a small amount of other elements such as Cr, Nb, and Re may be added to the above-described metal reflective film of the present invention. The thickness of the metal reflective layer is preferably 200 to 2000Å, more preferably 300 to 800Å. If it is too thick, the sensitivity will decrease, and if it is too thin, the reflectance of the reflective film will decrease and the C / N will deteriorate.
これら金属反射層の形成方法としては、公知の真空蒸
着法、スパッタリング法、イオンビームスパッタリング
法、CVD法などが考えられるが、下地層との接着性、合
金組成の制御性、組成分布などの点でスパッタリング法
が好ましい。また膜の堆積速度、スパッタガス圧など
は、生産性、膜応力を考慮し、適宣選択される。Known methods such as vacuum vapor deposition, sputtering, ion beam sputtering, and CVD can be considered as the method of forming these metal reflective layers, but the adhesion to the underlayer, the controllability of the alloy composition, the composition distribution, etc. Therefore, the sputtering method is preferable. The deposition rate of the film, the sputtering gas pressure, etc. are appropriately selected in consideration of productivity and film stress.
本発明の光記録媒体としては、前述の光磁気記録媒体
の他、周知のコンパクトディスク、ビデオディスク等反
射膜を用いるものであれば特に限定されないことは本発
明の趣旨から明らかである。中でも酸化し易い希土類元
素等を含む記録層を用いる光磁気記録媒体に特に好まし
く適用できる。It is apparent from the gist of the present invention that the optical recording medium of the present invention is not particularly limited as long as it uses a reflection film such as a well-known compact disc or video disc in addition to the above-mentioned magneto-optical recording medium. Above all, it is particularly preferably applicable to a magneto-optical recording medium using a recording layer containing a rare earth element which is easily oxidized.
ところで、この光磁気記録媒体の光磁気記録層として
は、光熱磁気効果により記録できるものであればよく、
公知の、膜面に垂直な方向に磁化容易方向を有し、磁気
光学効果の大きい磁性金属薄膜、例えば前述のFeTb合
金、FeTbCo合金、FeTbGd合金及びNdDyFeCo合金、等の希
土類元素−遷移金属元素の非晶質合金が代表例として挙
げられる。光磁気記録層の膜厚は150〜1000Å、好まし
くは200〜500Åである。By the way, the magneto-optical recording layer of this magneto-optical recording medium may be any as long as it can record by the photothermomagnetic effect,
Known, having a direction of easy magnetization in a direction perpendicular to the film surface, a magnetic metal thin film having a large magneto-optical effect, for example, the above-mentioned FeTb alloy, FeTbCo alloy, FeTbGd alloy and NdDyFeCo alloy, rare earth elements-transition metal element Amorphous alloys are a typical example. The film thickness of the magneto-optical recording layer is 150 to 1000Å, preferably 200 to 500Å.
本発明における光磁気記録媒体は、その金属反射層が
光磁気記録層の光入射面と反対側に形成される点を除い
てその構成は特に限定されない。なお、金属反射層は光
磁気記録層上に直接設けても、またその上に記録感度、
C/N,耐久性向上の目的で透明誘電体層を介して設けても
よい。The structure of the magneto-optical recording medium of the present invention is not particularly limited except that the metal reflection layer is formed on the side opposite to the light incident surface of the magneto-optical recording layer. The metal reflection layer may be provided directly on the magneto-optical recording layer, or the recording sensitivity,
It may be provided via a transparent dielectric layer for the purpose of improving C / N and durability.
本発明のAlAuTi合金からなる金属反射膜は光磁気記録
層に接して直接設けた構成で、その記録感度とC/Nにお
いて実用上充分と云われる性能を示し、上記透明誘電体
層が不要となるので、この構成が生産性と媒体コストの
観点より好ましい。The metal reflective film made of the AlAuTi alloy of the present invention is provided directly in contact with the magneto-optical recording layer, and shows the performance that is practically sufficient in its recording sensitivity and C / N, and the transparent dielectric layer is not necessary. Therefore, this configuration is preferable from the viewpoint of productivity and medium cost.
一方前記の通り記録再生特性、更には耐久性の向上の
ためには、多少構成は複雑になるが、光磁気記録層と金
属反射層との間に透明誘電体層を設けた構成が好まし
い。各構成は必要に応じて選択される。On the other hand, as described above, in order to improve the recording / reproducing characteristics and further the durability, the structure is somewhat complicated, but the structure in which the transparent dielectric layer is provided between the magneto-optical recording layer and the metal reflection layer is preferable. Each configuration is selected as needed.
なお、光磁気記録層と金属反射層との間に、透明誘電
体層を設ける場合においては、その透明誘導体層は最適
性能を得るためにはその膜厚を600Å以下と薄くする必
要があり、その断熱作用が小さくなるため、本発明は効
果的である。また、一般的に、該透明誘電体層が厚くな
る程、その断熱効果が高くなり、本発明の金属反射膜の
Au及びTiの含有量は少なくてよい。In the case of providing a transparent dielectric layer between the magneto-optical recording layer and the metal reflective layer, the transparent dielectric layer needs to have a thin film thickness of 600 Å or less in order to obtain optimum performance. The present invention is effective because its heat insulating effect is reduced. In general, the thicker the transparent dielectric layer is, the higher its heat insulating effect is.
The content of Au and Ti may be small.
本発明の光磁気記録媒体は、通常は基板と光磁気記録
層の間に、C/N向上、媒体の反射率低減、さらには透湿
防止の目的で、透明誘電体層を設ける。In the magneto-optical recording medium of the present invention, a transparent dielectric layer is usually provided between the substrate and the magneto-optical recording layer for the purpose of improving C / N, reducing the reflectance of the medium, and preventing moisture permeation.
上記構成に用いる基板側，金属反射層側の両透明誘電
体層としては、その目的により光干渉効果、カー効果エ
ンハンスメント等の効果を奏することが必要で、ある程
度以上の高屈折率を有することが好ましい。また使用す
るレーザー光に透明であることが必要であり、透明誘電
体層としては公知の通りの金属の酸化物、窒化物、硫化
物、炭化物、弗化物もしくはこれらの複合体が適用でき
る。具体的には酸化ケイ素、酸化インジウム、酸化タン
タル、酸化アルミニウム、チッ化ケイ素、チッ化アルミ
ニウム、チッ化チタン、硫化亜鉛、フッ化マグネシウ
ム、フッ化アルミニウム、炭化ケイ素及びこれら複合物
が挙げられるが、これに限定されないことは言うまでも
ない。なお、これらの誘電体は、C/Nの著しい低下のな
い範囲で多少の光吸収があってもかまわない。そして、
許容される限度内の光吸収が生じる程度の金属元素を膜
中に含んでもよい。また、パリレン、ポリイミド、パラ
フィンなど有機物も適用できる。また、これら透明誘電
体層は複数の誘電体層の積層されたものでもよい。The transparent dielectric layers on the substrate side and the metal reflective layer side used in the above-mentioned structure are required to have effects such as optical interference effect and Kerr effect enhancement depending on the purpose, and may have a high refractive index higher than a certain level. preferable. Further, it is necessary to be transparent to the laser light used, and as the transparent dielectric layer, known metal oxides, nitrides, sulfides, carbides, fluorides or composites thereof can be applied. Specific examples include silicon oxide, indium oxide, tantalum oxide, aluminum oxide, silicon nitride, aluminum nitride, titanium nitride, zinc sulfide, magnesium fluoride, aluminum fluoride, silicon carbide and composites thereof. Needless to say, it is not limited to this. It should be noted that these dielectrics may have some light absorption as long as the C / N does not significantly decrease. And
The film may contain a metal element to the extent that light absorption occurs within an allowable limit. Also, organic materials such as parylene, polyimide, and paraffin can be applied. Further, these transparent dielectric layers may be a stack of a plurality of dielectric layers.
なお、光磁気記録層等の酸化し易い記録層に接する透
明誘電体層は、その酸化劣化防止の面より窒化物等の酸
素を含まないものが好ましい。中でも窒化シリコン，窒
化アルミニウム，アルミニウム・シリコン窒化物が膜
質，膜応力の観点から好ましく適用される。これら透明
誘電体層の膜厚は、媒体構成、屈折率により最適値が変
化する。例えば前述の光磁気記録層の両側に透明誘電体
層を設けた構成では基板と光磁気記録層との間の透明誘
電体層の膜厚によって、光磁気記録層と金属反射層との
間の透明誘電体層の最適膜厚も変化するので、一義的に
決めることはできないが、通常は、基板と光磁気記録層
との間の透明誘電体膜厚が300〜1600Å程度、光磁気記
録層と金属反射層との間の透明誘電体膜厚が30〜600Å
が好適に用いられる。しかしもちろん、これらの膜厚範
囲に限定されるものではない。これら透明誘電体層は常
法により形成される。例えば前述の無機物よりなるもの
は公知の真空蒸着法、スパッタリング法、イオンビーム
スパッタリング法、CVD法等で作製される。The transparent dielectric layer that is in contact with a recording layer such as a magneto-optical recording layer that is easily oxidized is preferably a layer that does not contain oxygen such as a nitride from the viewpoint of preventing oxidative deterioration. Among them, silicon nitride, aluminum nitride, and aluminum-silicon nitride are preferably applied from the viewpoint of film quality and film stress. The optimum film thickness of these transparent dielectric layers changes depending on the medium structure and refractive index. For example, in the configuration in which the transparent dielectric layers are provided on both sides of the magneto-optical recording layer described above, depending on the film thickness of the transparent dielectric layer between the substrate and the magneto-optical recording layer, the distance between the magneto-optical recording layer and the metal reflective layer may be different. The optimum thickness of the transparent dielectric layer also changes, so it cannot be uniquely determined, but normally, the transparent dielectric film thickness between the substrate and the magneto-optical recording layer is about 300 to 1600Å, and the magneto-optical recording layer The transparent dielectric film thickness between the metal and the metal reflective layer is 30 ~ 600Å
Is preferably used. However, of course, it is not limited to these film thickness ranges. These transparent dielectric layers are formed by a conventional method. For example, the above-mentioned inorganic material is produced by a known vacuum deposition method, sputtering method, ion beam sputtering method, CVD method, or the like.
また基板としては、ガラス、アクリル樹脂、ポリカー
ボネート樹脂、エポキシ樹脂、４−メチルペンテン樹脂
及びそれらの変成品などが好適に用いられるが、機械的
強度、価格、耐候性、低透湿量の点でポリカーボネート
樹脂が好ましい。さらに、前記金属反射層上に無機材料
からなる保護層を設けることもできる。無機保護層を設
けることにより、高温高湿化の耐久性や、酸性ガス等の
腐蝕性ガスに体する耐久性を更に改善することができ
る。この無機保護層としては耐透湿性，ガスバリヤ性の
良いものであれば特に限定されないが、記録特性、耐久
性面より熱伝導率が低く、それ自身耐久性に優れている
ものが好ましく適用される。かかる無機保護層として
は、金属膜と誘電体膜が挙げられる。金属膜は、それ自
身の耐久性が充分高く、かつ媒体の記録感度を低下させ
ないために熱伝導率が低いことが必要である。そのよう
な特性を有する金属であれば特に限定する必要はない
が、中でもTi,Cr,Ni及びこれらの合金からなる金属膜は
特に好ましい。なお、金属膜の膜厚は上記諸点より10〜
300Åが好ましく、更に好ましくは30〜250Åである。一
方誘電体膜は、熱伝導率が低く膜厚が厚くても記録特性
への影響が小さく、十分な保護ができる点で優れてい
る。かかる誘電体膜には前述のエンハンス層等として公
知の透明誘電体がそのまま適用できるが特に耐透湿性も
良いという点で窒化アルミニウム、窒化シリコン，アル
ミニウム・シリコン窒化物の窒化物膜，酸化シリコン，
酸化チタンの酸化物膜が好ましく、中でも窒化物膜が酸
素が関係しない点で好ましい。誘電体膜の膜厚は、その
材料の熱伝導度，生産性，耐久性改善に及ばす効果によ
って決められる。一義的には言えないが、10〜500Å、
好ましくは50〜300Åが好適に用いられる。Further, as the substrate, glass, acrylic resin, polycarbonate resin, epoxy resin, 4-methylpentene resin and modified products thereof are preferably used, but in view of mechanical strength, price, weather resistance and low moisture permeability, Polycarbonate resin is preferred. Furthermore, a protective layer made of an inorganic material may be provided on the metal reflective layer. By providing the inorganic protective layer, the durability against high temperature and high humidity and the durability against corrosive gas such as acid gas can be further improved. The inorganic protective layer is not particularly limited as long as it has good moisture permeation resistance and gas barrier property, but a material having low thermal conductivity and excellent durability per se in view of recording characteristics and durability is preferably applied. . Examples of such an inorganic protective layer include a metal film and a dielectric film. The metal film is required to have sufficiently high durability and low thermal conductivity so as not to reduce the recording sensitivity of the medium. There is no particular limitation as long as it is a metal having such characteristics, but among them, metal films made of Ti, Cr, Ni and alloys thereof are particularly preferable. The thickness of the metal film is 10 to 10 from the above points.
It is preferably 300Å, more preferably 30 to 250Å. On the other hand, the dielectric film is excellent in that it has a small thermal conductivity and a large film thickness, has little influence on recording characteristics, and can be sufficiently protected. A known transparent dielectric material such as the above-mentioned enhance layer can be directly applied to such a dielectric film, but aluminum nitride, silicon nitride, a nitride film of aluminum-silicon nitride, silicon oxide,
An oxide film of titanium oxide is preferable, and a nitride film is particularly preferable because oxygen is not involved. The film thickness of the dielectric film is determined by the effect of improving the thermal conductivity, productivity, and durability of the material. I can't say it unequivocally, but 10-500Å,
50 to 300Å is preferably used.
また、この無機保護層は光記録層，金属反射層の上面
だけでなく、それらの端部を覆うことによりその効果は
一層顕著になる。Further, the effect becomes more remarkable by covering not only the upper surfaces of the optical recording layer and the metal reflective layer but also the end portions of the inorganic protective layer.
前記無機保護層の形成方法としては、公知の真空蒸着
法、スパッタリング法、イオンビームスパッタリング
法、CVD法などが考えられるが、下地層との接着性、合
金組成の制御性、組成分布などの点でスパッタリング法
が好ましい。また製膜時の堆積速度、ガス圧などは、生
産性、膜応力を考慮し、適宣選択される。The method for forming the inorganic protective layer may be a known vacuum vapor deposition method, sputtering method, ion beam sputtering method, CVD method, etc., but the adhesiveness with the underlayer, the controllability of the alloy composition, the composition distribution, etc. Therefore, the sputtering method is preferable. The deposition rate and gas pressure during film formation are appropriately selected in consideration of productivity and film stress.
本発明の光記録媒体の基本構成は、基板／第一透明誘
電体層／光磁気記録層／第二透明誘電体層／金属反射層
／無機保護層を一例とし、第一，第二透明誘電体層と無
機保護層は、前記の如く、価格，生産性，記録感度,C/N
比、要求される使用環境における耐久性を考慮して適宣
省略され得るものである。さらに、この無機保護層又は
金属反射層上に、ダスト，指紋，腐食を加速する物質、
等の汚染，機械的損傷等を防止する目的で、通常は光又
は／及び熱硬化型樹脂，あるいは熱可塑性樹脂からなる
有機保護層が数μｍ〜数＋μｍの厚さに塗布される。ま
た基板の光入射側には、媒体を高速回転させた時のダス
トとの接触により発生する傷を防止する目的で、硬度の
高い有機樹脂が数μｍ〜数＋μｍの圧さに塗布されるこ
ともある。なお、有機保護層には静電気防止剤を含浸さ
せてもよい。The basic structure of the optical recording medium of the present invention is, for example, substrate / first transparent dielectric layer / magneto-optical recording layer / second transparent dielectric layer / metal reflective layer / inorganic protective layer, and the first and second transparent dielectric layers are used. As mentioned above, the body layer and the inorganic protective layer are price, productivity, recording sensitivity, C / N.
In comparison, it can be appropriately omitted in consideration of the durability in the required use environment. Furthermore, on this inorganic protective layer or metal reflective layer, dust, fingerprints, substances that accelerate corrosion,
For the purpose of preventing contamination such as the above, mechanical damage, etc., an organic protective layer usually made of a light or / and thermosetting resin or a thermoplastic resin is applied to a thickness of several μm to several + μm. Further, on the light incident side of the substrate, an organic resin having high hardness is applied at a pressure of several μm to several + μm in order to prevent scratches caused by contact with dust when the medium is rotated at a high speed. There is also. The organic protective layer may be impregnated with an antistatic agent.
以上の構成（単板媒体）のディスクは、公知の通り、
そのまま、あるいは保護平板，保護フィルム等と貼合わ
せて適当なケース（カセット）に入れて片面記録媒体と
して使用することもあり、また２枚のディスクをホット
メルト接着剤、等で貼合わせて両面記録媒体として使用
することもある。The disc having the above configuration (single plate medium) is, as is known,
It may be used as it is or as a single-sided recording medium by putting it in a suitable case (cassette) by adhering it with a protective flat plate, protective film, etc., or by laminating two disks with a hot melt adhesive, etc., double-sided recording. It may also be used as a medium.
以下、光磁気記録媒体に適用した実施例を説明する
が、本発明は以下の実施例に限定されるものではない。Examples applied to a magneto-optical recording medium will be described below, but the present invention is not limited to the following examples.
＜比較例１〜２＞ 直径130mm、厚さ1.2mmの円盤で1.6μｍピッチのグル
ープを有するポリカーボネート樹脂（PC）製のディスク
基板を、３ターゲット設置可能な高周波マグネトロンス
パッタ装置（アネルバ（株）製SPF−430H型）の真空槽
内に配置し、４×10-7Torrになるまで排気した。<Comparative Examples 1 and 2> A high frequency magnetron sputtering apparatus (available from Anelva Co., Ltd.) capable of installing 3 targets of a disk substrate made of a polycarbonate resin (PC) having a disk having a diameter of 130 mm and a thickness of 1.2 mm and having a group of 1.6 μm pitch. It was placed in a vacuum chamber (SPF-430H type) and evacuated to 4 × 10 −7 Torr.
次にAr、N2の混合ガス（Ar:N2＝70:30vol％）を真空
槽内に導入し、圧力10m TorrになるようにAr/N2混合ガ
ス流量を調整した。ターゲットとしては直径100mm、厚
さ5mmのAl50Si50（以下、添数字は組成（原子％）を示
す）の焼結体からなる円盤を用い、放電電力500W、放電
周波数13.56MHzで高周波スパッタリングを行ない、PC基
板を回転（自転）させながら、透明誘電体としてAlSiN
膜を800Å堆積した。Next, a mixed gas of Ar and N 2 (Ar: N 2 = 70: 30 vol%) was introduced into the vacuum chamber, and the flow rate of the Ar / N 2 mixed gas was adjusted so that the pressure was 10 m Torr. As the target, a disk made of a sintered body of 100 mm in diameter and 5 mm in thickness of Al 50 Si 50 (hereinafter, the subscripts indicate the composition (atomic%)) was used, and high frequency sputtering was performed at a discharge power of 500 W and a discharge frequency of 13.56 MHz. AlSiN as a transparent dielectric while rotating (rotating) the PC substrate
A film of 800 Å was deposited.
続いて光磁気記録層として、Tb21Fe71Co8合金ターゲ
ットを用い、Arガス圧2m Torr、放電電力150Wの条件で
高周波スパッタリングを行ない、約300ÅのTbFeCo合金
膜を堆積した。Subsequently, using a Tb 21 Fe 71 Co 8 alloy target as the magneto-optical recording layer, high frequency sputtering was performed under the conditions of Ar gas pressure of 2 m Torr and discharge power of 150 W to deposit a TbFeCo alloy film of about 300 Å.
更に引き続いて、Alターゲットを用い、適宣3mm角×1
mm厚のAuチップをターゲット上に配し、Arガス圧2m Tor
r、放電電力100Wの条件下で高周波スパッタリングを行
い、表−１の比較例２の各組成で400Åの金属反射層を
堆積し、PC基板/AlSiN/TbFeCo/金属反射層の積層構成の
光磁気ディスクを得た。金属反射層のAl合金膜のAu量は
Alターゲット上のAuチップの数を調整して表１の比較例
２の組成に調整した。Furthermore, subsequently, using an Al target, an appropriate 3 mm square × 1
Place a mm-thick Au chip on the target and set the Ar gas pressure to 2 m Tor.
High-frequency sputtering was performed under the conditions of r and discharge power of 100 W, and 400 Å metal reflective layer was deposited with each composition of Comparative Example 2 in Table-1, and the magneto-optical properties of PC substrate / AlSiN / TbFeCo / metal reflective layer were laminated. I got a disc. The amount of Au in the Al alloy film of the metal reflection layer is
The composition of Comparative Example 2 in Table 1 was adjusted by adjusting the number of Au chips on the Al target.
これら各層の形成時において、PC基板は20rpmで回転
させた。During the formation of each of these layers, the PC substrate was rotated at 20 rpm.
得られた光磁気ディスクは光磁気記録再生装置（ナカ
ミチ（株）製OMS−1000型）を用い、下記条件でC/Nと最
適記録レーザーパワーを評価した。書込み時の半導体レ
ーザーパワーを変化させ、再生信号の二次高周波が最小
となる時が最適記録条件とした。The obtained magneto-optical disk was evaluated for C / N and optimum recording laser power under the following conditions using a magneto-optical recording / reproducing apparatus (OMS-1000 type manufactured by Nakamichi Co., Ltd.). The optimum recording condition was set when the semiconductor laser power during writing was changed and the secondary high frequency of the reproduced signal was minimized.
［記録条件］ ディスク回転速度:1800rpm、記録トラック位置：半径
30mm位置、記録周波数:3.7MH1、記録時の印加磁界:500
エルステッド ［再生条件］ ディスク回転速度:1800rpm、読出レーザーパワー:1.2
mW 記録感度の指標となる最適記録レーザーパワー及びC/
Nの測定結果を表−１に示す。[Recording conditions] Disk rotation speed: 1800 rpm, recording track position: radius
30mm position, recording frequency: 3.7MH1, applied magnetic field during recording: 500
Oersted [Playback conditions] Disc rotation speed: 1800 rpm, Read laser power: 1.2
Optimum recording laser power and C /
The measurement results of N are shown in Table-1.
なお、表−１の比較例１は金属反射層以外は比較例２
と同じ構成で、金属反射層を比較例２のAuチップを除去
して形成したAuを含有しない単なるAl反射膜を有する光
磁気ディスクである。またその最適記録レーザーパワー
の欄の20mW以上は、用いたレーザーの最大出力10mWでも
記録できず、ディスク回転速度を上述の半分に低下して
最大出力10mWで記録した時少しの再生信号が得られたこ
とを表わしたものである。In addition, Comparative Example 1 of Table-1 is Comparative Example 2 except for the metal reflective layer.
A magneto-optical disk having the same structure as described above but having a simple Al reflective film containing no metal and formed by removing the Au chip of Comparative Example 2. In addition, the maximum recording laser power of 20 mW or more could not be recorded even with the maximum output of 10 mW of the laser used, and when the disk rotation speed was reduced to half the above and recording at the maximum output of 10 mW, a little reproduction signal was obtained. It means that.
また比較例１のディスクの金属反射層上に、スピンコ
ーターで紫外線硬化型のフェノールノボラックエポキシ
アクリレート樹脂を塗布し、その後紫外線照射により硬
化させ、約20μｍの有機保護層を設けた。これらのサン
プルを、温度80℃、湿度85％の条件で1000時間の加速劣
化試験を行ない、その間のピンホール数の増加で評価し
たところ、比較例１ではピンホールが多数発生し、増加
数は計数できなかった。なお、同時にこの有機保護層を
設けた例の最適記録レーザーパワー,C/Nを測定したとこ
ろ、C/Nは表−１と同じで変化なかったが、最適記録レ
ーザーパワーは表−１に対して約0.8mW増加することが
わかった。すなわち有機保護膜は耐久性向上に有利であ
るが記録感度面からは不利であることがわかった。 Further, an ultraviolet curable phenol novolac epoxy acrylate resin was applied on the metal reflective layer of the disk of Comparative Example 1 by a spin coater and then cured by ultraviolet irradiation to provide an organic protective layer of about 20 μm. These samples were subjected to an accelerated deterioration test for 1000 hours under the conditions of a temperature of 80 ° C. and a humidity of 85% and evaluated by an increase in the number of pinholes during that time. In Comparative Example 1, a large number of pinholes were generated, and the increased number was I could not count. At the same time, when the optimum recording laser power and C / N of the example in which this organic protective layer was provided were measured, the C / N was the same as in Table-1 and did not change. It was found that it increased by about 0.8 mW. That is, it was found that the organic protective film is advantageous in improving durability but disadvantageous in recording sensitivity.
＜実施例１＞ 金属反射層を、比較例１〜２のAlターゲットにかえて
均一な組成分布を面方向，厚さ方向ともに有する100mm
φ×5mm厚AlAuTi合金ターゲットを用いて、比較例１〜
２と同じ高周波スパッタリングで形成したAl90.7Au7.2T
i2.1合金膜とした以外は比較例１〜２と同じ構成の光磁
気記録ディスクを比較例１〜２と同様にして作製した。
比較例１〜２と同じように評価し、最適記録レーザーパ
ワー5.7mWでC/N＝46.8dBを得た。表−１と比較して判断
される様に、C/Nも良好であった。<Example 1> 100 mm having a metal reflection layer having a uniform composition distribution in both the plane direction and the thickness direction in place of the Al targets of Comparative Examples 1 and 2.
Comparative Example 1-using a φ × 5 mm thick AlAuTi alloy target
Al 90.7 Au 7.2 T formed by the same high frequency sputtering as 2
A magneto-optical recording disk having the same structure as in Comparative Examples 1 and 2 except that the i 2.1 alloy film was used was prepared in the same manner as in Comparative Examples 1 and 2.
Evaluation was made in the same manner as Comparative Examples 1 and 2, and C / N = 46.8 dB was obtained at the optimum recording laser power of 5.7 mW. As judged by comparison with Table-1, C / N was also good.
以上の実施例に示した如く、本発明のAuにTiを含有し
たAl合金からなる金属反射膜ではC/N、感度が優れ、か
つ耐久性も高い光磁気記録媒体を得ることができた。特
に、上記の実施例１の構成媒体では、AuとTiの合計の含
有量が3.0at％以上の範囲では、最適記録レーザーパワ
ーの低下すなわち記録感度の向上が顕著で、C/Nも良好
である。As shown in the above examples, a magneto-optical recording medium having excellent C / N, sensitivity and high durability could be obtained with the metal reflective film made of an Al alloy containing Au and Ti according to the present invention. In particular, in the constituent medium of Example 1 described above, when the total content of Au and Ti is 3.0 at% or more, the decrease of the optimum recording laser power, that is, the improvement of the recording sensitivity is remarkable, and the C / N is also good. is there.
＜実施例2,比較例3,4＞ 実施例１の積層構成において、その光磁気記録層と金
属反射層との間に第２の透明誘電体層を設けた、基板／
第１の透明誘電体層／光磁気記録層／第２の透明誘電体
層／金属反射層／有機保護層の積層構成の光磁気記録媒
体を以下のように金属反射層を替えて作成し、前述の実
施例と同様に評価した。<Example 2, Comparative Examples 3 and 4> In the laminated structure of Example 1, a substrate / a second transparent dielectric layer was provided between the magneto-optical recording layer and the metal reflective layer.
A magneto-optical recording medium having a laminated structure of the first transparent dielectric layer / magneto-optical recording layer / second transparent dielectric layer / metal reflective layer / organic protective layer was prepared by replacing the metal reflective layer as follows, Evaluation was carried out in the same manner as in the above-mentioned examples.
直径130mm、厚さ1.2mmの円盤で1.6μｍピッチのグル
ープを有するポリカーボネート樹脂（PC）製のディスク
基板を、３ターゲット設置可能な高周波マゲネトロンス
パッタ装置（アネルバ（株）製SPF−430H型）の真空槽
内に配置し、４×10-7Torrになるまで排気した。A high-frequency magneteron sputtering device (Model SPF-430H manufactured by Anerva Co., Ltd.) on which a polycarbonate resin (PC) disk substrate having a diameter of 130 mm and a thickness of 1.2 mm and a group of 1.6 μm pitch can be installed on three targets. It was placed in a vacuum chamber and evacuated to 4 × 10 −7 Torr.
次にAr、N2の混合ガス（Ar:N2＝70:30vol％）を真空
槽内に導入し、圧力10m TorrになるようにAr/N2混合ガ
ス流量を調整した。ターゲットとしては直径100mm、厚
さ5mmのAl30Si70の焼結体からなる円盤を用い、放電電
力500W、放電周波数13.56MHzで高周波スパッタリングを
行ない、PC基板を回転（自転）させながら、第１の透明
誘電体層としてAlSiN膜を1200Å堆積した。Next, a mixed gas of Ar and N 2 (Ar: N 2 = 70: 30 vol%) was introduced into the vacuum chamber, and the flow rate of the Ar / N 2 mixed gas was adjusted so that the pressure was 10 m Torr. As a target, a disk made of a sintered body of Al 30 Si 70 with a diameter of 100 mm and a thickness of 5 mm was used, and high frequency sputtering was performed at a discharge power of 500 W and a discharge frequency of 13.56 MHz, while rotating (rotating) the PC substrate. The AlSiN film was deposited as 1200 Å as the transparent dielectric layer.
続いて光磁気記録層として、Tb21Fe71Co8合金ターゲ
ットを用い、Arガス圧2m Torr、放電電力150Wの条件で
高周波スパッタリングを行ない、約225ÅのTbFeCo合金
膜を堆積した。Subsequently, as a magneto-optical recording layer, using a Tb 21 Fe 71 Co 8 alloy target, high frequency sputtering was performed under the conditions of Ar gas pressure of 2 m Torr and discharge power of 150 W to deposit a TbFeCo alloy film of about 225 Å.
次いで第１の透明誘電体層と全く同じようにして第２
の透明誘電体層としてAlSiN膜を400Å堆積した。The second transparent dielectric layer is then formed in exactly the same way as the second transparent dielectric layer.
AlSiN film was deposited as a transparent dielectric layer of 400 Å.
更に引き続いて、実施例１のAlAuTi合金ターゲット
（実施例２），及びAlターゲット上に適宣3mm角×1mm厚
のTiチップ（比較例４）を配した複合ターゲットを用
い、Arガス圧2m Torr、放電電力100Wの条件で高周波ス
パッタリングを行い、表−２の実施例2,比較例４の各組
成で600Åの金属反射層を堆積し、PC基板/AlSiN/TbFeCo
/AlSiN/金属反射層の積層構成の光磁気ディスクを得
た。金属反射層のAl合金膜のTiの量はAlターゲット上の
Tiチップの数を調整して表２の比較例４の組成に調整し
た。Further, subsequently, using an AlAuTi alloy target of Example 1 (Example 2) and a composite target in which a Ti chip of 3 mm square × 1 mm thickness (Comparative Example 4) was placed on the Al target, Ar gas pressure was 2 m Torr. Then, high frequency sputtering was performed under the condition of a discharge power of 100 W, and a 600 Å metal reflective layer was deposited with each composition of Example 2 and Comparative Example 4 in Table-2, and PC substrate / AlSiN / TbFeCo
A magneto-optical disk with a laminated structure of / AlSiN / metal reflective layer was obtained. The amount of Ti in the Al alloy film of the metal reflection layer is on the Al target.
The composition of Comparative Example 4 in Table 2 was adjusted by adjusting the number of Ti chips.
これら各層の形成時において、PC基板は20rpmで回転
させた。During the formation of each of these layers, the PC substrate was rotated at 20 rpm.
なお、表−２の比較例３は金属反射層以外は実施例２
と同じ構成で、金属反射層を比較例１と同じようにして
形成したAuを含有しない単なるAl反射膜を有する光磁気
ディスクである。In addition, Comparative Example 3 in Table 2 is the same as Example 2 except for the metal reflection layer.
A magneto-optical disk having the same structure as described above but having a simple Al reflective film containing no metal and having a metal reflective layer formed in the same manner as in Comparative Example 1.
そして、得られた各磁気ディスクの金属反射層上に、
スピンコーターで紫外線硬化型のフェノールボラックエ
ポキシアクリレート樹脂を塗布し、紫外線硬化ささせ、
約20μｍの有機保護層を設けた。得られた各光磁気ディ
スクについて実施例１〜４と同様にC/Nと最適記録レー
ザーパワーを評価した。その結果を表−２に示した。Then, on the metal reflection layer of each obtained magnetic disk,
Apply UV curable phenolvolac epoxy acrylate resin with a spin coater and cure with UV,
An organic protective layer of about 20 μm was provided. The C / N and the optimum recording laser power of each of the obtained magneto-optical disks were evaluated in the same manner as in Examples 1 to 4. The results are shown in Table-2.
次に得られた各光磁気ディスクのサンプルを比較例１
〜２と同様に温度80℃，相対湿度85％の条件で1000時間
の加速劣化テストを行った。そしてテスト後のテスト前
に対する目視によるピンホールの増加数で評価した。そ
の結果を表−２に示した。Next, the samples of the obtained magneto-optical disks were compared with Comparative Example 1.
Similar to the above, the accelerated deterioration test was conducted for 1000 hours under the conditions of temperature 80 ° C and relative humidity 85%. Then, the number of pinholes visually increased after the test and before the test was evaluated. The results are shown in Table-2.
表−２より比較例３では、TbFeCoの光磁気記録層と金
属反射層との間に設けた第２の透明誘電体層のAlSiN膜
の断熱作用の効果で、比較例１と異なり記録可能であっ
たが、依然として最適記録レーザーパワーが大きく、C/
Nが低く、特に耐久性が劣ることがわかる。又比較例４
は最適記録レーザーパワー,C/Nの面では問題ないが、比
較例３同様に耐久性が劣る。 From Table-2, Comparative Example 3 is different from Comparative Example 1 in that recording is possible due to the heat insulating effect of the AlSiN film of the second transparent dielectric layer provided between the TbFeCo magneto-optical recording layer and the metal reflective layer. However, the optimum recording laser power is still large and C /
It can be seen that N is low and durability is particularly poor. Comparative Example 4
Has no problem in terms of optimum recording laser power and C / N, but is inferior in durability as in Comparative Example 3.
これに対し、実施例のAuを0.5at％以上含有する合金
からなる金属反射層では記録感度（最適記録レーザーパ
ワー）,C/N及び耐久性の面での改善が得られ、耐久性面
でも問題のない光磁気ディスクが得られた。特にAuとTi
の合計の含有量が1.0at％以上の範囲では記録感度の向
上が顕著でC/N,耐久性も良好である。かかる効果の点で
AuとTiの合計の含有量は1.0〜15.0at％が特に好まし
い。On the other hand, in the metal reflective layer made of an alloy containing 0.5 at% or more of Au in the example, the recording sensitivity (optimum recording laser power), C / N and durability were improved, and durability was also improved. A magneto-optical disk having no problem was obtained. Especially Au and Ti
When the total content of C is 1.0 at% or more, the recording sensitivity is remarkably improved, and the C / N and durability are also good. In terms of this effect
The total content of Au and Ti is particularly preferably 1.0 to 15.0 at%.
又、実施例１との比較から、第２の透明誘電体層を設
けると積層構成は若千複雑となるが、最適記録レーザー
パワーで1mW以上低下し、C/Nで0.4〜1.0dB程度の改善が
得られると同時に、耐久性面でも大巾な改善が得られる
ことがわかる。Further, as compared with Example 1, when the second transparent dielectric layer is provided, the laminated structure becomes complicated, but the optimum recording laser power is reduced by 1 mW or more, and the C / N is about 0.4 to 1.0 dB. It is understood that at the same time that the improvement is obtained, the durability is greatly improved.
＜実施例３＞ 金属反射層まで実施例２の全く同様に形成し、次いで
その金属反射層のAlAuTi合金膜上に更に無機保護層とし
てAlSiN膜を実施例２の第1,第２の透明誘電体層と全く
同様にして200Å形成し、更に実施例２と同じようにし
て該AlSiNの無機保護層上に約20μｍの実施例２と同じ
有機保護層を設けて、基板／第１の透明誘電体層／光磁
気記録層／第２の透明誘電体層／金属反射層／無機保護
層／有機保護層の積層構造の光磁気ディスクを作製し、
実施例２と同じように評価した。最適記録レーザーパワ
ーは5.5mW,C/Nは47.6dBで実施例２と同じ結果であっ
た。<Example 3> A metal reflective layer was formed in exactly the same manner as in Example 2, and then an AlSiN film was further used as an inorganic protective layer on the AlAuTi alloy film of the metal reflective layer. 200 Å was formed in exactly the same manner as the body layer, and the same organic protective layer as in Example 2 having a thickness of about 20 μm was provided on the inorganic protective layer of AlSiN in the same manner as in Example 2, and the substrate / first transparent dielectric layer was formed. A magneto-optical disk having a laminated structure of body layer / magneto-optical recording layer / second transparent dielectric layer / metal reflective layer / inorganic protective layer / organic protective layer is prepared,
Evaluation was performed in the same manner as in Example 2. The optimum recording laser power was 5.5 mW and the C / N was 47.6 dB, which was the same result as in Example 2.
加速劣化テストは、温湿度は前述までの実施例と同じ
80℃,85％RHの条件で、テスト時間は3000時間とし、実
施例２のサンプルと共に評価した。その結果実施例２で
は中心孔近傍のグルーブのないフラットな非記録部に多
数のピンホールの発生が認められた。これに対し無機保
護層付の本例ではかかるピンホールの発生は全くなく、
耐久性面で一層の改善が得られることがわかった。In the accelerated deterioration test, the temperature and humidity are the same as those in the previous examples.
The test time was 3000 hours under the conditions of 80 ° C. and 85% RH, and the sample of Example 2 was evaluated. As a result, in Example 2, a large number of pinholes were found in the flat non-recording portion having no groove near the center hole. On the other hand, in this example with an inorganic protective layer, there is no such pinhole,
It was found that further improvement in durability can be obtained.
＜実施例４＞ 実施例３で得られた２枚のサンプルをその保護層側で
ホットメルト接着剤により貼合わせて両面記録の光磁気
ディスクとし、これまでの実施例と同様に評価した。こ
の両面記録媒体のC/Nと記録感度は実施例３と測定誤差
範囲内で同じであり、良好であった。加速劣化テストは
実施例３と同じ3000時間行なった。タスクテクノロジー
（株）製のエラーレートテスターを用い、この加速劣化
テスト前後の記録面全体のバイトエラーレートの変化を
評価したところ、テスト後のそれはテスト前に対して両
面それぞれ実用上許容範囲の２倍以下の1.5倍と1.8倍の
変化であった。更に耐久性評価として60℃,95％RHの雰
囲気でスタートし、60℃と−25℃との間の環境変化を１
サイクル２日でくりかえし行うサイクルテスト（ZADテ
スト）を20サイクル行ったが、バイトエラーレートは４
×10-6と２×10-6のままで変化なく、非常に耐久性に優
れていることが確認された。<Example 4> The two samples obtained in Example 3 were laminated on the protective layer side with a hot melt adhesive to form a double-sided recording magneto-optical disk, and evaluated in the same manner as in the previous Examples. The C / N and recording sensitivity of this double-sided recording medium were the same as in Example 3 within the measurement error range, and were good. The accelerated deterioration test was conducted for the same 3000 hours as in Example 3. Using an error rate tester manufactured by Task Technology Co., Ltd., the change in the byte error rate of the entire recording surface before and after this accelerated deterioration test was evaluated. The changes were 1.5 times and 1.8 times less than twice. Furthermore, as a durability evaluation, start in an atmosphere of 60 ° C and 95% RH, and measure the environmental change between 60 ° C and -25 ° C as 1
A cycle test (ZAD test) was repeated 20 days, and the byte error rate was 4
It was confirmed that the durability was very good with no change at × 10 -6 and 2 × 10 -6 .
───────────────────────────────────────────────────── フロントページの続き (72)発明者 千葉 潔 東京都日野市旭が丘４丁目３番２号 帝 人株式会社東京研究センター内 (56)参考文献 特開 平２−267752（ＪＰ，Ａ) 特開 平３−25738（ＪＰ，Ａ) ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kiyoshi Chiba 4-3-2 Asahigaoka, Hino City, Tokyo Teijin Limited Tokyo Research Center (56) Reference JP-A-2-267752 (JP, A) Special Features Kaihei 3-25738 (JP, A)
Claims (7)
該金属反射層がAlにAuを0.5〜15at％含有せしめ、さら
にTiを0.3〜5.0at％含有せしめたAlAuTi合金からなるこ
とを特徴とする光記録媒体。1. An optical recording medium having a metal reflective layer,
An optical recording medium characterized in that the metal reflection layer is made of an AlAuTi alloy in which 0.5 to 15 at% of Au is contained in Al and 0.3 to 5.0 at% of Ti is further contained.
である請求項第１項記載の光記録媒体。2. The total content of Au and Ti is 1.0 to 15 at%.
The optical recording medium according to claim 1, wherein
れた請求項第１項もしくは第２項記載の光記録媒体。3. The optical recording medium according to claim 1, wherein the metal reflective layer is provided in contact with the optical recording layer.
電体層が設けられた請求項第１項もしくは第２項記載の
光記録媒体。4. The optical recording medium according to claim 1, wherein a transparent dielectric layer is provided between the metal reflective layer and the optical recording layer.
項第１項，第２項，第３項もしくは第４項記載の光記録
媒体。5. The optical recording medium according to claim 1, 2, 3, or 4, wherein an inorganic protective layer is provided on the metal reflective layer.
電体層を設けた請求項第１項，第２項，第３項，第４項
もしくは第５項記載の光記録媒体。6. An optical recording medium according to claim 1, wherein a transparent dielectric layer is provided on the side of the optical recording layer opposite to the metal reflection layer. .
徴とする請求項第１項，第２項，第３項，第４項，第５
項もしくは第６項記載の光記録媒体。7. The optical recording layer is a magneto-optical recording layer, as defined in claim 1, claim 2, claim 3, claim 4, claim 5, and claim 5.
Item 6. The optical recording medium according to Item 6.
Priority Applications (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2017284 CA2017284C (en) | 1989-07-04 | 1990-05-22 | Optical recording medium |
| US07/528,981 US5093174A (en) | 1989-07-04 | 1990-05-25 | Optical recording medium |
| DE1990622497 DE69022497T2 (en) | 1989-07-04 | 1990-06-02 | Optical recording medium. |
| EP19900110529 EP0406569B1 (en) | 1989-07-04 | 1990-06-02 | Optical recording medium |
| KR1019900009111A KR100194131B1 (en) | 1989-07-04 | 1990-06-21 | Optical recording media |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17119189 | 1989-07-04 | ||
| JP1-171191 | 1989-07-04 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH03130947A JPH03130947A (en) | 1991-06-04 |
| JP2559871B2 true JP2559871B2 (en) | 1996-12-04 |
Family
ID=15918700
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2029432A Expired - Fee Related JP2559871B2 (en) | 1989-07-04 | 1990-02-13 | Optical recording medium |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2559871B2 (en) |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62141662A (en) * | 1985-12-17 | 1987-06-25 | Canon Inc | Reproducing system for photomagnetic recording medium |
| JP2670846B2 (en) * | 1989-04-07 | 1997-10-29 | 富士写真フイルム株式会社 | Optical recording medium |
| JPH0325738A (en) * | 1989-06-23 | 1991-02-04 | Teijin Ltd | Magneto-optical recording medium |
-
1990
- 1990-02-13 JP JP2029432A patent/JP2559871B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH03130947A (en) | 1991-06-04 |
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