JPH06282876A - 光記録媒体 - Google Patents

光記録媒体

Info

Publication number
JPH06282876A
JPH06282876A JP5069636A JP6963693A JPH06282876A JP H06282876 A JPH06282876 A JP H06282876A JP 5069636 A JP5069636 A JP 5069636A JP 6963693 A JP6963693 A JP 6963693A JP H06282876 A JPH06282876 A JP H06282876A
Authority
JP
Japan
Prior art keywords
recording
protective layer
sio
film
laser light
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.)
Pending
Application number
JP5069636A
Other languages
English (en)
Inventor
Katsumi Kawahara
克巳 河原
Shigeaki Furukawa
惠昭 古川
Noboru Yamada
昇 山田
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Panasonic Holdings Corp
Original Assignee
Matsushita Electric Industrial Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Matsushita Electric Industrial Co Ltd filed Critical Matsushita Electric Industrial Co Ltd
Priority to JP5069636A priority Critical patent/JPH06282876A/ja
Priority to US08/219,109 priority patent/US5453346A/en
Publication of JPH06282876A publication Critical patent/JPH06282876A/ja
Pending legal-status Critical Current

Links

Classifications

    • GPHYSICS
    • G11INFORMATION STORAGE
    • G11BINFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/24Record carriers characterised by shape, structure or physical properties, or by the selection of the material
    • GPHYSICS
    • G11INFORMATION STORAGE
    • G11BINFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/24Record carriers characterised by shape, structure or physical properties, or by the selection of the material
    • G11B7/241Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material
    • G11B7/252Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers
    • G11B7/257Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of layers having properties involved in recording or reproduction, e.g. optical interference layers or sensitising layers or dielectric layers, which are protecting the recording layers
    • G11B7/2578Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of layers having properties involved in recording or reproduction, e.g. optical interference layers or sensitising layers or dielectric layers, which are protecting the recording layers consisting essentially of inorganic materials
    • GPHYSICS
    • G11INFORMATION STORAGE
    • G11BINFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/24Record carriers characterised by shape, structure or physical properties, or by the selection of the material
    • G11B7/241Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material
    • G11B7/242Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of recording layers
    • G11B7/243Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of recording layers comprising inorganic materials only, e.g. ablative layers
    • G11B2007/24302Metals or metalloids
    • G11B2007/24312Metals or metalloids group 14 elements (e.g. Si, Ge, Sn)
    • GPHYSICS
    • G11INFORMATION STORAGE
    • G11BINFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/24Record carriers characterised by shape, structure or physical properties, or by the selection of the material
    • G11B7/241Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material
    • G11B7/242Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of recording layers
    • G11B7/243Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of recording layers comprising inorganic materials only, e.g. ablative layers
    • G11B2007/24302Metals or metalloids
    • G11B2007/24314Metals or metalloids group 15 elements (e.g. Sb, Bi)
    • GPHYSICS
    • G11INFORMATION STORAGE
    • G11BINFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/24Record carriers characterised by shape, structure or physical properties, or by the selection of the material
    • G11B7/241Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material
    • G11B7/242Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of recording layers
    • G11B7/243Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of recording layers comprising inorganic materials only, e.g. ablative layers
    • G11B2007/24302Metals or metalloids
    • G11B2007/24316Metals or metalloids group 16 elements (i.e. chalcogenides, Se, Te)
    • GPHYSICS
    • G11INFORMATION STORAGE
    • G11BINFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/24Record carriers characterised by shape, structure or physical properties, or by the selection of the material
    • G11B7/241Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material
    • G11B7/252Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers
    • G11B7/257Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of layers having properties involved in recording or reproduction, e.g. optical interference layers or sensitising layers or dielectric layers, which are protecting the recording layers
    • G11B2007/25705Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of layers having properties involved in recording or reproduction, e.g. optical interference layers or sensitising layers or dielectric layers, which are protecting the recording layers consisting essentially of inorganic materials
    • G11B2007/25706Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of layers having properties involved in recording or reproduction, e.g. optical interference layers or sensitising layers or dielectric layers, which are protecting the recording layers consisting essentially of inorganic materials containing transition metal elements (Zn, Fe, Co, Ni, Pt)
    • GPHYSICS
    • G11INFORMATION STORAGE
    • G11BINFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/24Record carriers characterised by shape, structure or physical properties, or by the selection of the material
    • G11B7/241Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material
    • G11B7/252Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers
    • G11B7/257Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of layers having properties involved in recording or reproduction, e.g. optical interference layers or sensitising layers or dielectric layers, which are protecting the recording layers
    • G11B2007/25705Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of layers having properties involved in recording or reproduction, e.g. optical interference layers or sensitising layers or dielectric layers, which are protecting the recording layers consisting essentially of inorganic materials
    • G11B2007/2571Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of layers having properties involved in recording or reproduction, e.g. optical interference layers or sensitising layers or dielectric layers, which are protecting the recording layers consisting essentially of inorganic materials containing group 14 elements except carbon (Si, Ge, Sn, Pb)
    • GPHYSICS
    • G11INFORMATION STORAGE
    • G11BINFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/24Record carriers characterised by shape, structure or physical properties, or by the selection of the material
    • G11B7/241Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material
    • G11B7/252Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers
    • G11B7/257Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of layers having properties involved in recording or reproduction, e.g. optical interference layers or sensitising layers or dielectric layers, which are protecting the recording layers
    • G11B2007/25705Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of layers having properties involved in recording or reproduction, e.g. optical interference layers or sensitising layers or dielectric layers, which are protecting the recording layers consisting essentially of inorganic materials
    • G11B2007/25715Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of layers having properties involved in recording or reproduction, e.g. optical interference layers or sensitising layers or dielectric layers, which are protecting the recording layers consisting essentially of inorganic materials containing oxygen
    • GPHYSICS
    • G11INFORMATION STORAGE
    • G11BINFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/24Record carriers characterised by shape, structure or physical properties, or by the selection of the material
    • G11B7/241Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material
    • G11B7/252Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers
    • G11B7/257Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of layers having properties involved in recording or reproduction, e.g. optical interference layers or sensitising layers or dielectric layers, which are protecting the recording layers
    • G11B2007/25705Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of layers having properties involved in recording or reproduction, e.g. optical interference layers or sensitising layers or dielectric layers, which are protecting the recording layers consisting essentially of inorganic materials
    • G11B2007/25716Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of layers having properties involved in recording or reproduction, e.g. optical interference layers or sensitising layers or dielectric layers, which are protecting the recording layers consisting essentially of inorganic materials containing sulfur
    • GPHYSICS
    • G11INFORMATION STORAGE
    • G11BINFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/24Record carriers characterised by shape, structure or physical properties, or by the selection of the material
    • G11B7/241Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material
    • G11B7/252Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers
    • G11B7/253Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of substrates
    • G11B7/2533Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of substrates comprising resins
    • G11B7/2534Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of substrates comprising resins polycarbonates [PC]
    • GPHYSICS
    • G11INFORMATION STORAGE
    • G11BINFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/24Record carriers characterised by shape, structure or physical properties, or by the selection of the material
    • G11B7/241Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material
    • G11B7/252Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers
    • G11B7/254Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of protective topcoat layers
    • G11B7/2542Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of protective topcoat layers consisting essentially of organic resins
    • GPHYSICS
    • G11INFORMATION STORAGE
    • G11BINFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/24Record carriers characterised by shape, structure or physical properties, or by the selection of the material
    • G11B7/241Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material
    • G11B7/252Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers
    • G11B7/256Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of layers improving adhesion between layers
    • GPHYSICS
    • G11INFORMATION STORAGE
    • G11BINFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/24Record carriers characterised by shape, structure or physical properties, or by the selection of the material
    • G11B7/241Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material
    • G11B7/252Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers
    • G11B7/258Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of reflective layers
    • G11B7/2595Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of reflective layers based on gold
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10STECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S430/00Radiation imagery chemistry: process, composition, or product thereof
    • Y10S430/146Laser beam

Landscapes

  • Chemical & Material Sciences (AREA)
  • Inorganic Chemistry (AREA)
  • Optical Record Carriers And Manufacture Thereof (AREA)

Abstract

(57)【要約】 【目的】 レ−ザ光等の照射により熱的に記録薄膜の光
学的な状態を変化させて情報を記録および消去する媒体
において、線速度の高い領域での消去率の高い光ディス
クを提供することである。 【構成】 第二の保護層に熱伝導率の大きいSiO2
多く用いることにより、レ−ザ光等による照射の熱が媒
体の厚さ方向ではなく基板の面方向に熱が逃げ、それに
より記録マーク部のセンターと記録マーク部の端の温度
差が小さくなり、消去率および消去のパワーマージンを
広げるることが出来るものである。更に、保護層は同一
の材料から構成されているため、設備が簡素化でき成膜
時における膜の品質も安定なものができる。

Description

【発明の詳細な説明】
【0001】
【産業上の利用分野】本発明はレ−ザ−ビ−ム等によ
り、情報を高密度、大容量で記録再生及び消去できる光
記録媒体に関するものである。
【0002】
【従来の技術】光ディスクメモリに関しては、TeとT
eO2を主成分とするTeOx(0<x<2.0)薄膜を用い
た追記型のディスクがある。また繰り返し記録・消去が
可能な書換え型と呼ばれるものの開発が進められてい
る。この書換え型の光ディスクのひとつとして、Te−
Ge−Sb合金薄膜を記録層として用い、レ−ザ光によ
り記録薄膜を加熱し、溶融し、急冷することにより、非
晶質化して情報を記録し、またこれを加熱し徐冷するこ
とにより結晶化して情報を消去するものがある。これら
の薄膜をレ−ザ光ガイド用の溝を設けた基板に形成し、
光ディスクとして用いることができる。これらのディス
クにレ−ザ光で情報を記録し、その情報を消去する方法
としてはあらかじめ薄膜を結晶化させておき、これに半
値巾で1μmφ程度に絞ったレ−ザ光を情報に対応させ
てピークパワーとバイアスパワーで強度変調を施す。
【0003】例えば円盤状の記録ディスクを回転せしめ
て照射した場合、このピ−クパワ−レ−ザ光照射部位
は、薄膜の融点以上に昇温し、かつ急冷し、非晶質化し
たマ−クとして情報の記録がおこなえる。また、この変
調バイアスパワ−レ−ザ光照射部位は、薄膜の結晶化温
度以上に昇温し、既記録信号情報を消去する働きがあり
オ−バライトできる。
【0004】このように記録薄膜はレ−ザ光によって融
点以上に昇温し、また結晶化温度以上に昇温されるもの
である。このため記録薄膜の下面および上面に、耐熱性
のすぐれた誘電体層を基板および接着層に対する保護層
として設けているのが一般的である。これらの保護層の
熱伝導特性により、昇温および急冷、徐冷の特性が変わ
るものであるから、保護層の材質を選ぶことによって記
録および消去の特性を決めることができるものである。
【0005】
【発明が解決しようとする課題】記録薄膜を加熱昇温
し、溶融急冷非晶質化および加熱昇温結晶化の手段を用
いる情報記録および消去可能なオ−バライト記録媒体に
おいて、記録膜への記録マーク形成はレーザ光による膜
の融点以上の加熱昇温および急冷が必要である。消去は
膜の結晶化温度以上の加熱昇温し徐冷することにより結
晶化して消去する。
【0006】課題は、線速度の高い領域では、記録マー
ク部の中央と端とでは温度差があり、更に、加熱昇温し
徐冷する時間が短くなるため、記録マーク部の端の部分
が加熱昇温と徐冷する時間が不十分となり、消し残りが
発生し消去率が低くなることである。
【0007】本発明の目的は、記録マーク部全体の温度
差を小さくして、消去率の高い光ディスクを提供するこ
とである。
【0008】
【課題を解決するための手段】本発明は透明基板の一方
の面に、第一の保護層、記録薄膜、第二の保護層、反射
層を順次形成したもので、第一の保護層と第二の保護層
はZnSとSiO2 との混合膜材料である。それを、レ
−ザ光等の照射により、熱的に記録薄膜の光学的な状態
を変化させて情報を記録および消去する媒体において、
第二の保護層を第一の保護層よりもSiO2比を大きく
して、線速度の速い領域での消去率を高くするものであ
る。
【0009】
【作用】すなわち、第二の保護層のSiO2比を大きく
して、SiO2を多く用いることで熱伝導率が大きくな
り、レ−ザ光等による照射の熱が逃げにくくなり、記録
マーク部の中央と端の温度差を小さくすることができ
る。それにより、加熱昇温し徐冷することができ、消去
率を高くすることができるものである。
【0010】
【実施例】以下図面に基づいて本発明を説明する。本発
明の記録媒体の代表的な構造例を図1に示す。記録,再
生、及び消去を行うレーザ光は基板1の側から入射させ
る。
【0011】基板1としては、PMMA,ポリカーボネ
ート等の樹脂或はガラス等、表面の平滑なものを用い
る。光ディスクの場合、通常基板平面8はレーザ光を導
くためにスパイラル又は同心円状の連続溝(トラッ
ク)、或はピット列等の凹凸で覆われている。
【0012】保護層2,4の材料は、物理的・化学的に
安定、すなわち記録材料の融点よりも、融点及び軟化温
度が高く、かつ記録材料と相固溶しないことが望まし
い。例えば、Al2O3,SiOx,Ta2O5,MoO3,WO
3,ZrO2,ZnS,AlNx,BN,SiNx,TiN,Zr
N,PbF2,MgF2等の誘電体或はこれらの適当な組み
合わせからなる。保護層は誘電体や透明である必要はな
い。例えば可視光線及び赤外線に対して光吸収性をもつ
ZnTeで形成してもよい。又、保護層2,4を異なる材
料で形成すると、熱的及び光学的なディスク設計の自由
度が大きくなる利点がある。もちろん同一材料で形成し
てもよい。
【0013】記録薄膜3は、結晶状態と非晶質状態との
間で可逆的に構造変化をおこす物質、例えばTe又はI
n,Se等を主成分とする相変化材料からなる。よく知ら
れた相変化材料の主成分としては、Te-Sb-Ge,Te-
Ge,Te-Ge-Sn,Te-Ge-Sn-Au,Sb-Se,Sb-T
e,Sb-Se-Te,In-Te,In-Se,In-Se-Tl,In
-Sb,In-Sb-Se,In-Se-Te等が挙げられる。これ
らの薄膜は通常、非晶質状態で成膜されるが、レーザ光
等のエネルギーを吸収して結晶化し、光学定数(屈折率
n、消衰係数k)が変化する。
【0014】反射層5は、Au,Al,Ni,Fe,Cr等
の金属元素、或はこれらの合金からなり、記録薄膜への
光吸収効率を高める働きをする。しかし、例えば記録薄
膜3の膜厚を厚くして光吸収効率を高める工夫をするこ
とによって、反射層6を設けない構成とすることも可能
である。或は、記録薄膜と保護層を交互に複数回積み重
ねた構成とすることにより、記録薄膜1層あたりの膜厚
が薄くても、全体として光吸収効率を高めることもでき
る。
【0015】保護基板7は、樹脂をスピンコートした
り、基板と同様の樹脂板、ガラス板、或は金属板等を接
着剤6を用いて貼り合わせることによって形成する。さ
らには、2組の記録媒体を中間基板或は反射層を内側に
して接着剤を用いて貼り合わせることにより、両面から
記録,再生、消去可能な構造としてもよい。
【0016】記録薄膜,保護層,反射層は、通常、電子
ビーム蒸着法,スパタリング法,イオンプレーティング
法,CVD法,レーザスパタリング法等によって形成さ
れる。
【0017】(実施例1)以下、本発明の一実施例を図
面に基づいて説明する。図1において1はディスク基板
でポリカ−ボネイト等の樹脂基板からなっている。この
ディスク基板1は、あらかじめレ−ザ光案内用の溝を形
成した樹脂基板あるいは2P法で溝を形成したガラス
板、ガラス板に直接溝を形成した基板であってもよい。
2は第一の保護層でZnSーSiO2の混合膜でSiO2
比20mol%の誘電体からなっており、膜厚は約90
〜130nmである。3は記録薄膜Te−Ge−Sbから
なる合金薄膜であり、膜厚は約30〜50nmである。4
は第二の保護層でZnSーSiO2の混合膜の誘電体で
SiO2比が第一の保護層のSiO2比よりも大きく、本
実施例では50mol%を採用した。膜厚は、150n
m〜200nmである。5はAlからなる反射層で膜厚
は約40nmである。7は保護板で接着材6によってディ
スク基板1に貼り合わせている。
【0018】第一の保護層2にZnSーSiO2の混合
膜でSiO2比20mol%の誘電体を用いている。そ
れは、未記録領域(通常結晶状態をあてる)と記録マー
ク領域(通常非晶質状態をあてる)の反射光の位相差、
両領域間の反射率変化ΔR、記録層における両領域の最
適な吸収差を得るためである。特に、第一の保護層の光
学定数(屈折率n、消衰係数k)によって大きく変化す
るため、最適な吸収差及び反射率ΔRを導くのに第一の
保護層のSiO2比20mol%の光学定数を用いてい
る。第一の保護層の膜厚を約90〜130nmとしている
これは、光学的な吸収率とレーザ光等の照射熱からディ
スク基板1を保護するためである。
【0019】記録薄膜3の膜厚を約30〜50nmとして
いる、これは25nm以下では記録時における信号の振幅
が小さいためであり、55nm以上と膜厚が厚い場合、薄
膜を加熱昇温し、溶融急冷非晶質化および加熱昇温結晶
化の手段を用いるため厚いと薄膜を加熱昇温するのにレ
ーザ光のパワーを強くしなければならないといった低感
度なディスクになるからである。
【0020】第二の保護層のSiO2 比を大きくして熱
伝導率を大きくしている、それは、レーザ光のパワーを
強くしていくとレ−ザ光による照射の熱が媒体の厚さ方
向に逃げるため、図2に示す溝21に記録されたマーク
部のセンター22とマーク部周囲23とで温度差が発生
し、マーク部周囲23の温度が低いため徐冷できずに消
し残りが発生して消去率が低下する。そこで、熱伝導率
を大きくしてレ−ザ光による照射の熱を媒体の厚さ方向
にではなく基板の面方向に熱を逃がして、マーク部のセ
ンター22とマーク部周囲23とで温度差を小さくし
て、レーザ光のパワーが強い領域であっても記録マーク
部を徐冷して消去できパワーマージンが広がると考えた
からである。
【0021】膜厚は150〜200nm以下にしてい
る、これは、結晶領域及び非晶質領域の吸収率を60%
以上で、更に、結晶領域及び非晶質領域の反射率差を1
5%以上得るためである。
【0022】本実施例のディスク構成で、結晶の吸収率
は65.9%で非晶質の吸収率が64.2%であり反射
率の差が16.2%である。それを、記録周波数はf1
=15.00MHzの信号、f2=5.63MHzの信号のオ−バ−ラ
イト特性を測定した。オ−バ−ライトは、1個のサ−ク
ルスポットで半値巾で1μmφ程度に絞ったレ−ザ光に
より、高いパワ−レベル23〜25mW,低いパワ−レ
ベル9〜13mWの間の変調で、高いパワ−レベルで非
晶質化マ−クを形成し低いパワ−レベルで非晶質化マ−
クを結晶化して消去する同時消録の方法で行った。その
結果、記録信号のC/N比としては、50dB以上、消
去率24dB以上で記録消去のオーバライト回数10万
回以上が得られた。
【0023】第二の保護層を第一の保護層よりも、Si
2 比を大きくすることにより、105サイクル後の消
去率が26dB以上でパワーマージンの広い特性が得ら
れた。
【0024】なお、本実施例では、第2の保護層のSi
2 比を50mol%としたが、本願発明はこれに限定
されるものでなく、記録膜の熱的な感度を損なわなけれ
ば、どのような値を採用してもよい。
【0025】
【発明の効果】以上、説明したように第二の保護層を第
一の保護層よりもでZnSーSiO2のSiO2 比を大
きくして熱伝導率を大きくすることにより、レ−ザ光等
による照射の熱が媒体の厚さ方向ではなく基板の面方向
に熱が逃げ、それにより記録マーク部のセンターと記録
マーク部の端の温度差が小さくなり、消去率および消去
のパワーマージンを広げることが出来るものである。
【0026】更に、保護層は同一の材料から構成されて
いるため、設備が簡素化でき成膜時における膜の品質も
安定なものができる。
【図面の簡単な説明】
【図1】本発明の実施例1における光学情報記録媒体の
一部省略断面図
【図2】記録マーク部センターと記録マーク部周囲の関
係を示す図
【符号の説明】
1 ディスク基板 2 第一の保護層 3 記録薄膜 4 第二の保護層 5 反射層

Claims (3)

    【特許請求の範囲】
  1. 【請求項1】透明基板の一方の面に、第一の保護膜、レ
    −ザ光の照射により、そのエネルギ−を吸収して昇温
    し、溶融し、急冷し、非晶質化する性質と、非晶質の状
    態を昇温することにより、結晶化する性質を有する記録
    薄膜、第二の保護膜、反射層を順次形成した光記録媒体
    であって、前記第一、第二の保護膜は、ZnSとSiO
    2との混合膜であり、第二の保護膜は第一の保護膜より
    もSiO2比の大きい材料からなることを特徴とする光
    記録媒体。
  2. 【請求項2】第一の保護層のSiO2比は略20mol
    %であって、第二の保護層のSiO2比は20mol%
    以上からなることを特徴とする請求項1記載の光記録媒
    体。
  3. 【請求項3】第二の保護層のSiO2比は50mol%
    であることを特徴とする請求項1または2記載の光記録
    媒体。
JP5069636A 1993-03-29 1993-03-29 光記録媒体 Pending JPH06282876A (ja)

Priority Applications (2)

Application Number Priority Date Filing Date Title
JP5069636A JPH06282876A (ja) 1993-03-29 1993-03-29 光記録媒体
US08/219,109 US5453346A (en) 1993-03-29 1994-03-29 Optical information recording medium having protection layers with different properties on both sides of an optical active layer

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP5069636A JPH06282876A (ja) 1993-03-29 1993-03-29 光記録媒体

Publications (1)

Publication Number Publication Date
JPH06282876A true JPH06282876A (ja) 1994-10-07

Family

ID=13408555

Family Applications (1)

Application Number Title Priority Date Filing Date
JP5069636A Pending JPH06282876A (ja) 1993-03-29 1993-03-29 光記録媒体

Country Status (2)

Country Link
US (1) US5453346A (ja)
JP (1) JPH06282876A (ja)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0721583A (ja) * 1993-07-07 1995-01-24 Asahi Chem Ind Co Ltd 相変化型光ディスク
US8323763B2 (en) 2009-08-31 2012-12-04 Panasonic Corporation Information recording medium and method for producing the same

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AU683091B2 (en) * 1994-10-05 1997-10-30 Asahi Kasei Kogyo Kabushiki Kaisha Phase change mode optical disk and method of manufacturing the same
JPH08249725A (ja) 1995-03-08 1996-09-27 Ricoh Co Ltd 光情報記録媒体及びその製造に用いられる耐熱性保護層用材料
JP3525197B2 (ja) 1996-02-27 2004-05-10 株式会社リコー 相変化型光記録媒体
US5914214A (en) * 1996-12-06 1999-06-22 Matsushita Electric Industrial Co., Ltd. Method for manufacturing an optical information recording medium
US6086796A (en) * 1997-07-02 2000-07-11 Diamonex, Incorporated Diamond-like carbon over-coats for optical recording media devices and method thereof
JP2000235732A (ja) * 1999-02-12 2000-08-29 Sony Corp 多層光ディスク
US6511788B1 (en) * 1999-02-12 2003-01-28 Sony Corporation Multi-layered optical disc
JP4290279B2 (ja) * 1999-06-04 2009-07-01 独立行政法人産業技術総合研究所 光学試料体並びにその書込みおよび読出し方法
US6632583B2 (en) * 1999-12-07 2003-10-14 Mitsubishi Chemical Corporation Optical recording medium and production method of the same
JP3689612B2 (ja) * 2000-01-26 2005-08-31 株式会社日立製作所 情報記録媒体

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4847132A (en) * 1986-10-20 1989-07-11 Matsushita Electric Industrial Co., Ltd. Protective layer for optical information recording medium
JPS63103453A (ja) * 1986-10-20 1988-05-09 Matsushita Electric Ind Co Ltd 光学式情報記録部材
JPH02134741A (ja) * 1988-11-15 1990-05-23 Sekisui Chem Co Ltd 光情報記録媒体
JP2797359B2 (ja) * 1989-01-09 1998-09-17 東レ株式会社 光記録媒体
US5191565A (en) * 1989-06-19 1993-03-02 Matsushita Electric Industrial Co., Ltd. Optical information recording medium
JPH03241539A (ja) * 1990-02-19 1991-10-28 Matsushita Electric Ind Co Ltd 光学情報記録再生消去部材
US5194363A (en) * 1990-04-27 1993-03-16 Matsushita Electric Industrial Co., Ltd. Optical recording medium and production process for the medium

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0721583A (ja) * 1993-07-07 1995-01-24 Asahi Chem Ind Co Ltd 相変化型光ディスク
US8323763B2 (en) 2009-08-31 2012-12-04 Panasonic Corporation Information recording medium and method for producing the same

Also Published As

Publication number Publication date
US5453346A (en) 1995-09-26

Similar Documents

Publication Publication Date Title
US7002896B2 (en) Information recording medium and method for producing the same, and method for recording/reproducing information thereon
KR100418011B1 (ko) 정보 기록 매체 및 정보 기록 장치
USRE36624E (en) Optical recording media and information recording and reproducing units
JP3566743B2 (ja) 光記録媒体
US6333913B1 (en) Optical recording medium and optical recording method
JPH05144082A (ja) 光記録媒体と光記録媒体用保護膜
JPH06282876A (ja) 光記録媒体
JPH07105574A (ja) 光情報記録媒体
US5449589A (en) Method of making an optical information recording medium and method of recording/reproducing optical information
JP2002298433A (ja) 相変化光記録媒体
JP2778188B2 (ja) 光学情報記録再生消去部材
JP3138661B2 (ja) 相変化型光ディスク
JP2639174B2 (ja) 光記録媒体
JP3067035B2 (ja) 光記録媒体
JPH0312824A (ja) 相変化型光記録媒体の記録・消去・再生方法及び構成方法
JP2913759B2 (ja) 光記録媒体
KR100215790B1 (ko) 고밀도 상변화형 광디스크
JPH03232133A (ja) 光記録媒体と光記録媒体用保護膜と保護膜の製法
JP2982329B2 (ja) 情報光記録媒体とその記録再生方法
JP2972435B2 (ja) 情報光記録媒体とその記録再生方法
JPH0414485A (ja) 光学情報記録再生消去部材
JPH07262612A (ja) 相変化形光情報記録媒体
KR19990006606A (ko) 광학적 데이터 기록 매체
JP2004311011A (ja) 光学的情報記録媒体とその製造方法、この媒体を用いた情報の記録方法及び記録装置
JPH05151617A (ja) 光学式情報記録媒体とその製造方法