JP4108166B2 - Manufacturing method of optical information recording medium - Google Patents

Description

【００６０】
本実施例において、混合ガスの希ガス成分としてアルゴンを用いたが、Ｈｅ，Ｎｅ，Ｘｅなどの不活性ガスを用いれば、いずれも同様の効果が得られる。さらに、希ガスに酸素を混合してスパッタすることにより得られた機械的強度の効果を活かすためには、誘電体層２及び６の膜厚は１０ｎｍ以上あることが望ましい。
【００６１】
また、本参考例において、移動抑制層３及び５の膜厚は、３ｎｍ以上であれば、記録層へ酸素が拡散するのを抑制する効果が得られる。
【００６２】
（参考例２）
参考例１と同じ基板を用いて、記録層として参考例１と同様のＧｅ、Ｓｂ及びＴｅからなる３元材料、反射層として参考例１と同様のＡｌ合金、上下の保護層としてＺｎＳとＳｉＯ₂の混合材料をターゲットとして用いて光ディスクを作製した。なお、光ディスクの薄膜層を保護するために反射層の上に樹脂コートを施した。ここで、上下の保護層は雰囲気ガスの異なるスパッタリングで成膜された２層構造になっている。
【００６３】
図１を用いて説明すると、各層の膜厚は基板側から、保護層Ａの誘電体２が８０ｎｍ、移動抑制層３が５ｎｍ、記録層４が１７ｎｍ、保護層Ｂの移動抑制層５が４ｎｍ、誘電体６が１１ｎｍ、反射層７が１００ｎｍである。
【００６４】
保護層Ａ及びＢ各層の成膜は、スパッタパワー３００Ｗ、スパッタ雰囲気はＡｒ、Ｏ₂及びＮ₂の混合ガスを、流量２０ｓｃｃｍ、全圧１ｍＴｏｒｒの条件でスパッタ法で行ったが、保護層Ａの誘電体２と保護層Ｂの誘電体６は，亜酸化窒素濃度が０〜２０vol.％の範囲のアルゴンと亜酸化窒素の混合ガスの雰囲気で成膜した。また、保護層Ａの移動抑制層３及び保護層Ｂの移動抑制層５を成膜するときは、窒素濃度が２vol.％のアルゴンと窒素の混合ガスの雰囲気とした。
【００６５】
また、記録層はＧｅ、Ｓｂ及びＴｅの混合ターゲットを、アルゴンガスのみのスパッタ雰囲気で流量２０ｓｃｃｍ、全圧１ｍＴｏｒｒの条件下で、スパッタパワー８０Ｗで行い、反射層はＡｌとＣｒの混合ターゲットを、アルゴンガスのみのスパッタ雰囲気で流量２０ｓｃｃｍ、全圧２ｍＴｏｒｒの条件下で、スパッタパワー２００Ｗで行った。
【００６６】
作製した光ディスクを、参考例１と同様の方法で評価した。表２に、保護層Ａの誘電体２及び保護層Ｂの誘電体６を成膜する時の雰囲気中の亜酸化窒素濃度と、サイクル特性及び耐熱特性の関係の評価結果を示す。
【００６７】
亜酸化窒素濃度が０．１vol.％よりも小さい場合はサイクル特性が劣化しており、これは誘電体２及び誘電体６の機械的特性の回復がしていないと考えられる。
【００６８】
また、亜酸化窒素濃度が１５vol.％を越える場合はサイクル特性は良好であるが耐熱特性が劣化しており、移動抑制層３及び移動抑制層５を通り抜けて記録層中の構成元素に結合する酸素の量が急激に増加するためと考えられる。
【００６９】
従って、良好なサイクル特性及び耐熱特性が得られる亜酸化窒素濃度範囲としては、０．１vol.％以上１５vol.％以下であることが確認できた。
【００７０】
【表２】

【００７１】
本参考例において、混合ガスの希ガス成分としてアルゴンを用いたが、Ｈｅ，Ｎｅ，Ｘｅなどの不活性ガスを用いれば、いずれも同様の効果が得られる。
【００７２】
さらに、希ガスに酸素を混合してスパッタすることにより得られた機械的強度の効果を活かすためには、誘電体層２及び６の膜厚は１０ｎｍ以上あることが望ましい。
【００７３】
また、本参考例において、移動抑制層３及び５の膜厚は、３ｎｍ以上であれば、記録層へ酸素が拡散するのを抑制する効果が得られる。
【００７４】
（比較例１）
参考例１と同じ基板を用いて、記録層として参考例１と同様のＧｅ、Ｓｂ及びＴｅからなる３元材料、反射層として参考例１と同様のＡｌ合金、上下の第１及び第２の誘電体層としてＺｎＳとＳｉＯ₂の混合材料をターゲットとして用いて光ディスクを作製した。
【００７５】
各層の膜厚は基板側から、第１の誘電体層が８５ｎｍ、記録層が１７ｎｍ、第２の誘電体層が１５ｎｍ、反射層７が１００ｎｍである。各層の成膜条件は、第１及び第２の誘電体層のスパッタ雰囲気以外は参考例１と同様のスパッタ法で行った。第１の誘電体層と第２の誘電体層のスパッタ雰囲気は、窒素濃度が３％のアルゴンと窒素の混合ガスとした。なお、光ディスクの薄膜層を保護するために反射層の上に樹脂コートを参考例１と同様に施した。
【００７６】
この光ディスクを参考例１と同様の方法でサイクル特性と耐熱特性を評価し、その結果を表３に示す。表３から明らかなように、５０万回オーバーライト後と５０万回オーバーライト後に耐熱試験を施した後とではＣＮＲの特性に変化が見受けられないが、５０万回オーバーライト後及び耐熱試験後のＣＮＲは共に４８ｄＢで基準値を下回っている。
【００７７】
これは窒素添加により第１及び第２の誘電体層中からサイクルによって遊離するガス状の酸素の量は抑制されているため、記録層中のＧｅが酸化されることに起因する耐熱試験前後の特性変化はないことを示している。
【００７８】
（比較例２）
参考例１と同じ基板を用いて、記録層として参考例１と同様のＧｅ、Ｓｂ及びＴｅからなる３元材料、反射層として参考例１と同様のＡｌ合金、上下の第１及び第２の誘電体層としてＺｎＳとＳｉＯ₂の混合材料を用いて光ディスクを作製した。
【００７９】
各層の膜厚は基板側から、第１の誘電体層が８５ｎｍ、記録層が１７ｎｍ、第２の誘電体層が１５ｎｍ、反射層７が１００ｎｍである。各層の成膜条件は、第１及び第２の誘電体層のスパッタ雰囲気以外は参考例１と同様のスパッタ法で行った。第１の誘電体層と第２の誘電体層のスパッタ雰囲気は、酸素濃度が３vol.％のアルゴンと酸素の混合ガスとした。なお、光ディスクの薄膜層を保護するために反射層の上に樹脂コートを参考例１と同様に施した。
【００８０】
この光ディスクを参考例１と同様の方法でサイクル特性と耐熱特性を評価し、その結果を表３に示す。表３から明らかなように、５０万回サイクル後のＣＮＲは５４ｄＢと良好であるが、耐熱試験後のＣＮＲは３０ｄＢまで減少した。
【００８１】
これは酸素を添加することにより、誘電体中の酸素欠損を補償して膜の強度特性が向上しサイクル特性が向上しているが、サイクルによって膜中に存在するガス状の酸素が遊離しているため、記録層中のＧｅに結合して結晶温度が低下し、アモルファス相が不安定になるため耐熱特性が劣化したと考えられる。
【００８２】
（実施例１）
参考例１と同じ基板を用いて、記録層として参考例１と同様のＧｅ、Ｓｂ及びＴｅからなる３元材料、反射層として参考例１と同様のＡｌ合金、記録層の上下に２層構成の保護層Ａ及びＢを設けて光ディスクを作製した。なお、光ディスクの薄膜層を保護するために反射層の上に樹脂コートを施した。
【００８３】
図１を用いて説明すると、各層の膜厚は基板側から、保護層Ａの誘電体２が８０ｎｍ、保護層Ａの移動抑制層３が８ｎｍ、記録層４が１７ｎｍ、保護層Ｂの移動抑制層５が８ｎｍ、保護層Ｂの誘電体６が１１ｎｍ、反射層７が１００ｎｍである。
【００８４】
各層の成膜条件は、保護層Ａ及びＢ以外は参考例１と同様のスパッタ法で行った。保護層Ａ及びＢの内、誘電体２と誘電体６のスパッタ雰囲気は、酸素濃度１vol.％のアルゴンと酸素の混合ガスで、流量２０ｓｃｃｍで全圧１ｍＴｏｒｒ、材料としてはＺｎＳとＳｉＯ₂の混合材料をターゲットとし、スパッタパワー３００Ｗでスパッタリング成膜した。また、保護層Ａ及びＢの移動抑制層３および／または移動抑制層５は、Ｇｅをターゲットとし、窒素２０vol.％のアルゴンと窒素の混合ガス雰囲気を流量２０ｓｃｃｍで全圧５ｍＴｏｒｒ、スパッタパワー５００Ｗの条件で反応性スパッタで成膜し、Ｇｅの窒化物薄膜を形成した。
【００８５】
保護層Ａと保護層Ｂの両方にＧｅの窒化酸化物を成膜して作製した光ディスクを光ディスクＡ、保護層Ａの移動抑制層３のみＧｅの窒化酸化物を成膜して作製した光ディスクを光ディスクＢ、保護層Ｂの移動抑制層５のみＧｅの窒化酸化物を成膜して作製した光ディスクを光ディスクＣとする。光ディスクＢ及びＣの内、残りの移動抑制層５（光ディスクＢ）または移動抑制層３（光ディスクＣ）は、窒素濃度が２vol.％のアルゴンと窒素の混合ガスの雰囲気でＺｎＳとＳｉＯ₂の混合材料をスパッタリングして成膜した。これらの光ディスクを参考例１と同様の方法で、サイクル特性と耐熱特性を評価しその結果を表３に示す。
【００８６】
表３に示したように、光ディスクＡ、Ｂ及びＣ共に良好なサイクル特性及び耐熱特性が得られた。これは、保護層Ａの移動抑制層３および／または保護層Ｂの移動抑制層５をＧｅの窒化酸化物で構成することにより、耐熱試験によって保護層Ａの誘電体２及び／または保護層Ｂの誘電体６から遊離した酸素が、記録層中に拡散するのを抑制していると考えられる。
【００８７】
本実施例において、移動抑制層３および／または移動抑制層５の構成材料をＧｅの窒化酸化物としたが、記録層の構成元素の窒化物、窒化酸化物、炭化物、硫化物、フッ化物等も検討した結果、何れも従来に比べるとサイクル特性及び耐熱特性の向上が見受けられたが、特に、Ｇｅの窒化物、Ｓｉの窒化物または窒化酸化物、または記録層５の構成元素の窒化物または窒化酸化物で構成した場合に、良好なサイクル特性及び耐熱特性が得られた。
【００８８】
本実施例において、混合ガスの希ガス成分としてアルゴンを用いたが、Ｈｅ，Ｎｅ，Ｘｅなどの不活性ガスを用いれば、いずれも同様の効果が得られる。
【００８９】
また、保護層Ａの誘電体２および保護層Ｂの誘電体６の成膜時の雰囲気中の酸素濃度は、０．１〜１０vol.％の範囲で良好なサイクル特性及び耐熱特性が得られる。
【００９０】
（参考例３）
参考例１と同じ基板を用いて、記録層として参考例１と同様のＧｅ、Ｓｂ及びＴｅからなる３元材料、反射層として参考例１と同様のＡｌ合金、記録層の基板側に２層構成の保護層Ａ、記録層と反射層の間に単層の誘電体層を設けて光ディスクを作製した。なお、光ディスクの薄膜層を保護するために反射層の上に樹脂コートを施した。
【００９１】
図２を用いて説明すると、各層の膜厚は基板側から、保護層Ａの誘電体１２が８０ｎｍ、移動抑制層１３が８ｎｍ、記録層１４が１７ｎｍ、誘電体層１５が１５ｎｍ、反射層１６が１００ｎｍである。
【００９２】
各層の成膜条件は、保護層Ａと誘電体層以外は参考例１と同様のスパッタ法で行った。保護層Ａの誘電体１２は、酸素濃度３vol.％のアルゴンと酸素の混合ガスの雰囲気でＺｎＳとＳｉＯ₂の混合材料をスパッタリングして成膜した。保護層Ａの移動抑制層１３及び誘電体層１５は、各々の材料にともない実施例１と同一条件で行った。
【００９３】
なお、保護層Ａの移動抑制層１３および誘電体層１５は、窒素濃度２vol.％のアルゴンと窒素の混合ガスの雰囲気でＺｎＳとＳｉＯ₂の混合材料をスパッタリングして作製した光ディスクを光ディスクＤ、保護層Ａの移動抑制層１３はＧｅの窒化酸化物を成膜し、誘電体層１５は窒素濃度２vol.％のアルゴンと窒素の混合ガスの雰囲気でＺｎＳとＳｉＯ₂の混合材料をスパッタリングして作製した光ディスクを光ディスクＥ、保護層Ａの移動抑制層１３は窒素濃度２vol.％のアルゴンと窒素の混合ガスの雰囲気でＺｎＳとＳｉＯ₂の混合材料をスパッタリングして成膜し、誘電体層１５は光ディスクＥの移動抑制層１３と同じＧｅの窒化酸化物を成膜して作製した光ディスクを光ディスクＦとする。
【００９４】
これらの光ディスクを、参考例１と同様の方法でサイクル特性と耐熱特性を評価し、その結果を表３に示す。表３に示したように何れの光ディスクでも良好なサイクル特性及び耐熱特性が得られた。
【００９５】
本参考例において光ディスクＥの移動抑制層１３および光ディスクＦの誘電体層１５をＧｅの窒化酸化物で構成したが、記録層の構成元素の窒化物、窒化酸化物、炭化物、硫化物、フッ化物等も検討した結果、何れも従来に比べるとサイクル特性及び耐熱特性の向上が見受けられたが、特に、各種の金属の窒化物、酸化物またはフッ化物で検討を行ったところ、Ｇｅの窒化物、Ｓｉの窒化物または窒化酸化物、または記録層１５の構成元素の窒化物または窒化酸化物で構成した場合に、良好なサイクル特性及び耐熱特性が得られた。
【００９６】
また、保護層Ａの誘電体１２の成膜時の雰囲気中の酸素濃度は、０．１〜１０vol.％の範囲で良好なサイクル特性及び耐熱特性が得られる。
【００９７】
さらに、本参考例では希ガス中の酸化作用のあるガスとして酸素を用いたが、代わりに亜酸化窒素を用いた場合もサイクル特性及びたい熱特性が改善される。特に、亜酸化窒素の濃度を０．１〜１５vol.％の範囲にしたとき、良好なサイクル特性及び耐熱特性が得られた。
【００９８】
本参考例において、混合ガスの希ガス成分としてアルゴンを用いたが、Ｈｅ，Ｎｅ，Ｘｅなどの不活性ガスを用いれば、いずれも同様の効果が得られる。
【００９９】
（参考例４）
参考例１と同じ基板を用いて、記録層として参考例１と同様のＧｅ、Ｓｂ及びＴｅからなる３元材料、反射層として参考例１と同様のＡｌ合金、記録層の基板側に２層構成の保護層Ａ、記録層と反射層の間に単層の誘電体層を設けて光ディスクを作製した。なお、光ディスクの薄膜層を保護するために反射層の上に樹脂コートを施した。
【０１００】
図２を用いて説明すると、各層の膜厚は基板側から、保護層Ａの誘電体１２が８０ｎｍ、移動抑制層１３が８ｎｍ、記録層１４が１７ｎｍ、誘電体層１５が１５ｎｍ、反射層１６が１００ｎｍである。
【０１０１】
各層の成膜条件は、保護層Ａと誘電体層以外は参考例１と同様のスパッタ法で行った。保護層Ａの誘電体１２及び誘電体層１５は、酸素濃度１vol.％のアルゴンと酸素の混合ガスの雰囲気でＺｎＳとＳｉＯ₂の混合材料をスパッタリングして成膜し、移動抑制層１３はＧｅの窒化酸化物を成膜した。これら保護層Ａ及び誘電体層の構成材料に応じて、それぞれ実施例１と同一のスパッタ条件で成膜した。
【０１０２】
この光ディスクを参考例１と同様の方法でサイクル特性と耐熱特性を評価し、その結果を表３に示す。表３に示したように良好なサイクル特性及び耐熱特性が得られた。
【０１０３】
本参考例において、保護層Ａの移動抑制層１３および誘電体層１５をＧｅの窒化酸化物で構成したが、記録層の構成元素の窒化物、窒化酸化物、炭化物、硫化物、フッ化物等も検討した結果、何れも従来に比べるとサイクル特性及び耐熱特性の向上が見受けられたが、特に、各種の金属の窒化物、酸化物またはフッ化物で検討を行ったところ、Ｇｅの窒化物、Ｓｉの窒化物または窒化酸化物、または記録層１５の構成元素の窒化物または窒化酸化物で構成した場合に、良好なサイクル特性及び耐熱特性が得られた。
【０１０４】
また、保護層Ａの誘電体１２及び誘電体層１５の成膜時の雰囲気中の酸素濃度は、０．１〜１０vol.％の範囲で良好なサイクル特性及び耐熱特性が得られる。
【０１０５】
さらに、本参考例では希ガス中の酸化作用のあるガスとして酸素を用いたが、代わりに亜酸化窒素を用いた場合もサイクル特性及びたい熱特性が改善される。特に、亜酸化窒素の濃度を０．１〜１５vol.％の範囲にしたとき、良好なサイクル特性及び耐熱特性が得られた。
【０１０６】
特に、誘電体層１５は記録層１４に接しているが、厚さを保護層Ａ（誘電体１２及び移動抑制層１３）よりも薄くし、反射層１６と接していることによって、熱を放散しやすいため、サイクルオーバーライトによる膜中のガス状酸素の遊離が少なく、高温下において記録層へ拡散する酸素量が抑制されるので、良好な耐熱特性が得られると推測される。
【０１０７】
本参考例において、混合ガスの希ガス成分としてアルゴンを用いたが、Ｈｅ，Ｎｅ，Ｘｅなどの不活性ガスを用いれば、いずれも同様の効果が得られる。
【０１０８】
（参考例５）
参考例１と同じ基板を用いて、記録層として参考例１と同様のＧｅ、Ｓｂ及びＴｅからなる３元材料、反射層として参考例１と同様のＡｌ合金、記録層の基板側に単層の誘電体層、記録層と反射層の間に２層構成の保護層Ｂを設けて光ディスクを作製した。なお、光ディスクの薄膜層を保護するために反射層の上に樹脂コートを施した。
【０１０９】
図３を用いて説明すると、各層の膜厚は基板側から、誘電体層２２が８５ｎｍ、記録層２３が１７ｎｍ、保護層Ｂの移動抑制層２４が８ｎｍ、誘電体２５が１１ｎｍ、反射層２６が１００ｎｍである。
【０１１０】
各層の成膜条件は、保護層Ａと誘電体層以外は参考例１と同様のスパッタ法で行った。保護層Ｂの誘電体２５は酸素濃度３vol.％のアルゴンと酸素の混合ガスの雰囲気でＺｎＳとＳｉＯ₂の混合材料をターゲットとし、流量２０ｓｃｃｍ。全圧１ｍＴｏｒｒ、スパッタパワー３００Ｗの条件でスパッタリング成膜した。
【０１１１】
なお、誘電体層２２および保護層Ｂの移動抑制層２４は、窒素濃度２vol.％のアルゴンと窒素の混合ガスの雰囲気を流量２０ｓｃｃｍ、全圧１ｍＴｏｒｒで、ＺｎＳとＳｉＯ₂の混合材料をターゲットとし、スパッタパワー３００Ｗの条件でスパッタリングして作製した光ディスクを光ディスクＧとする。また、誘電体層２２は、窒素濃度２％のアルゴンと窒素の混合ガスの雰囲気を流量２０ｓｃｃｍ、全圧１ｍＴｏｒｒで、ＺｎＳとＳｉＯ₂の混合材料をターゲットとし、スパッタパワー３００Ｗの条件でスパッタリングして成膜し、保護層Ｂの移動抑制層２４は、実施例１で述べたスパッタ条件でＧｅの窒化酸化物を成膜して作製した光ディスクを光ディスクＨとする。
【０１１２】
これらの光ディスクを参考例１と同様の方法でサイクル特性と耐熱特性を評価し、その結果を表３に示す。表３に示したように、何れの光ディスクでも良好なサイクル特性及び耐熱特性が得られた。
【０１１３】
本参考例において、光ディスクＨの保護層Ｂの移動抑制層２４をＧｅの窒化酸化物で構成したが、記録層の構成元素の窒化物、窒化酸化物、炭化物、硫化物、フッ化物等も検討した結果、何れも従来に比べるとサイクル特性及び耐熱特性の向上が見受けられたが、特に、各種の金属の窒化物、酸化物またはフッ化物で検討を行ったところ、Ｇｅの窒化物、Ｓｉの窒化物または窒化酸化物、または記録層２３の構成元素の窒化物または窒化酸化物で構成した場合に、良好なサイクル特性及び耐熱特性が得られた。
【０１１４】
また、保護層Ｂの誘電体２５の成膜時の雰囲気中の酸素濃度は、０．１〜１０vol.％の範囲で良好なサイクル特性及び耐熱特性が得られる。
【０１１５】
本参考例において、混合ガスの希ガス成分としてアルゴンを用いたが、Ｈｅ，Ｎｅ，Ｘｅなどの不活性ガスを用いれば、いずれも同様の効果が得られる。
【０１１６】
参考例１〜参考例４および実施例１とを比較すると、光ディスクＥおよび光ディスクＦおよび参考例３がサイクル特性およびサイクル後の耐熱特性に優れ、かつ全層数が５層であるため作製の工程が少なく簡単であることが特徴である。
【０１１７】
（参考例６）
参考例１と同様の光ディスクの構造で、保護層Ａの誘電体２と保護層Ｂの誘電体６は、参考例１のアルゴンと酸素の混合ガスの雰囲気の代わりに、アルゴンと酸素と窒素の混合ガスの雰囲気でＺｎＳとＳｉＯ₂の混合材料をターゲットとし、スパッタリングして成膜する。但し、混合ガス中の酸素濃度は３vol.％で、窒素濃度は１vol.％であり、流量、全圧及びスパッタパワーは参考例１と同じである。
【０１１８】
この光ディスクを参考例１と同様の方法でサイクル特性と耐熱特性を評価したところ、表３に示したように良好なサイクル特性及び耐熱特性が得られた。本実施例において、参考例１と同様の光ディスクの構造としたが、参考例２、実施例１、参考例３または参考例４の何れの光ディスクの構造でも、アルゴンと酸素の混合ガスの雰囲気でＺｎＳとＳｉＯ₂の混合材料をスパッタリングして成膜される保護層の誘電体または誘電体層を、成膜することにより、良好なサイクル特性および耐熱特性が得られた。
【０１１９】
また、成膜時のアルゴンと酸素と窒素の混合ガス中の酸素濃度は、０．１〜１０vol.％の範囲で良好なサイクル特性及び耐熱特性が得られる。本実施例において、混合ガスの希ガス成分としてアルゴンを用いたが、Ｈｅ，Ｎｅ，Ｘｅなどの不活性ガスを用いれば、いずれも同様の効果が得られる。
【０１２０】
（参考例７）
参考例１と同様の光ディスクの構造で、保護層Ａの誘電体２と保護層Ｂの誘電体６は、参考例１のアルゴンと酸素の混合ガスの雰囲気の代わりに、アルゴンと空気の混合ガスの雰囲気でＺｎＳとＳｉＯ₂の混合材料をスパッタリングして成膜する。但し、混合ガス中のアルゴンと空気の割合は９９対３であり、流量、全圧及びスパッタパワーは参考例１と同じである。
【０１２１】
この光ディスクを参考例１と同様の方法でサイクル特性と耐熱特性を評価したところ、表３に示したように良好なサイクル特性及び耐熱特性が得られた。
【０１２２】
本実施例において、参考例１と同様の光ディスクの構造としたが、参考例２、実施例１、参考例３または参考例４の何れの光ディスクの構造でも、アルゴンと酸素の混合ガスの雰囲気でＺｎＳとＳｉＯ₂の混合材料をスパッタリングして成膜される保護層の誘電体または誘電体層を、成膜することにより、良好なサイクル特性および耐熱特性が得られた。但し、アルゴンと空気の割合は９９．９対０．１から９５対５の範囲が好ましい。
【０１２３】
本実施例において、混合ガスの希ガス成分としてアルゴンを用いたが、Ｈｅ，Ｎｅ，Ｘｅなどの不活性ガスを用いれば、いずれも同様の効果が得られる。
【０１２４】
（参考例８）
参考例１と同じ基板を用いて、記録層として参考例１と同様のＧｅ、Ｓｂ及びＴｅからなる３元材料、反射層として参考例１と同様のＡｌ合金、記録層を挟持する上下の誘電体層としてＺｎＳとＳｉＯ₂の混合材料を用いて、比較例１及び２と同じ構成の光ディスクを作製した。なお、光ディスクの薄膜層を保護するために反射層の上に樹脂コートを施した。比較例１及び２と異なる点は、上下の誘電体層を、雰囲気ガスの成分が連続的に変化するスパッタリングで成膜した単層構造にしたことである。
【０１２５】
各層の膜厚は基板側から、第１の誘電体層が８５ｎｍ、記録層が１７ｎｍ、第２の誘電体層が１５ｎｍ、反射層が１００ｎｍである。各層の成膜条件の内、第１及び第２の誘電体層以外は、参考例１と同様のスパッタ法で行った。第１及び第２の誘電体層は、記録層と反対側（基板または反射層側）では、酸素濃度が２vol.％のアルゴンと酸素の混合ガスの雰囲気でのスパッタリングによって成膜し、記録層に近づくに従い酸素の混合割合を徐々に窒素の置換し、記録層に接する側で２vol.％の範囲のアルゴンと窒素の混合ガスの雰囲気でのスパッタリングによって成膜した。
【０１２６】
この光ディスクを参考例１と同様の方法でサイクル特性と耐熱特性を評価したところ、表３に示したように良好なサイクル特性及び耐熱特性が得られた。
【０１２７】
また、第１の誘電体層および第２の誘電体層の記録層に接する側での成膜時の雰囲気中の混合ガス中の酸素濃度は０〜１０vol.％の範囲で、また、第１の誘電体層および第２の誘電体層の記録層と反対側（基板または反射層側）での成膜時の雰囲気中の窒素濃度は０〜５vol.％の範囲で良好なサイクル特性及び耐熱特性が得られた。
【０１２８】
本参考例において、混合ガスの希ガス成分としてアルゴンを用いたが、Ｈｅ，Ｎｅ，Ｘｅなどの不活性ガスを用いれば、いずれも同様の効果が得られる。
【０１２９】
【表３】

【０１３０】
【発明の効果】
以上説明した通り、本発明の光学的情報記録媒体の製造方法によれば、第一の誘電体層と、前記記録層の一方の主面に接し、前記第一の誘電体層を構成する酸素の前記記録層への移動を抑制可能とする移動抑制層とを有する保護層を形成する工程を含み、この工程において、希ガスと窒素とからなる混合雰囲気中でスパッタリングによって上記移動抑制層を成膜し、前記希ガスと酸素とを含む混合ガス雰囲気における酸素成分濃度が０．１ vol ．％以上１０ vol ．％以下であるので、機械的強度が高くてサイクル特性が向上しており、かつ、第一の誘電体層に含まれる酸素が記録層中に拡散し、記録層の構成元素Ｇｅと結合して、記録層の特性が変化することが抑制された光学的情報記録媒体、すなわち、耐熱性の優れた光学的情報記録媒体を提供できる。
【図面の簡単な説明】
【図１】本発明の一実施例の光学的情報記録媒体を示す模式的断面図である。
【図２】参考例の光学的情報記録媒体を示す模式的断面図である。
【図３】別の参考例の光学的情報記録媒体を示す模式的断面図である。
【符号の説明】
１ 基板
２ 保護層Ａの誘電体
３ 保護層Ａの移動抑制層
４ 記録層
５ 保護層Ｂの誘電体
６ 保護層Ｂの移動抑制層
７ 反射層
１１ 基板
１２ 保護層Ａの誘電体
１３ 保護層Ａの移動抑制層
１４ 記録層
１５ 誘電体層
１６ 反射層
２１ 基板
２２ 誘電体層
２３ 記録層
２４ 保護層Ｂの誘電体
２５ 保護層Ｂの移動抑制層
２６ 反射層[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a method of manufacturing an optical information recording medium that records, reproduces, and rewrites information at high density and high speed using optical means such as a laser beam.To the lawIt is related.
[0002]
[Prior art]
  A technique for recording and reproducing high-density information on an optical disk using a laser beam or the like is known, and is currently applied to a document file, a still image file, an external memory for a computer, and the like.
[0003]
  Research and development of a rewritable information recording system is also underway, one of which is a phase change optical disk. Phase change optical discs record signals using the fact that the recording film reversibly changes its optical state between amorphous and crystals (or between crystals having a structure different from that of crystals) by laser beam irradiation. A signal is reproduced by optically detecting a difference in state change as, for example, a difference in reflectance.
[0004]
  The phase change optical disk has a great merit that an overwrite for recording a new signal while erasing an old signal can be performed only by passing a laser spot once on a signal track. That is, when the laser beam power is modulated between the recording level and the erasing level according to the signal and irradiated, for example, in the case of a phase change between amorphous and crystal, the area irradiated at the recording level is determined by the presence or absence of the old signal. Regardless, since the recording film is melted and then cooled, it becomes amorphous, and the region irradiated at the erasing level is heated to the crystallization temperature or higher, so that it becomes a crystal regardless of the previous state.
[0005]
  The structure of a phase change optical disk is generally a three-layer structure in which a recording layer is sandwiched between dielectric layers and provided on a substrate, and a four-layer structure in which a reflective film is further provided thereon. The role of the dielectric layer is as follows: (1) increase the laser light absorptivity of the recording layer, (2) increase the reflectance change between the amorphous state and the crystalline state, and increase the reproduction signal amplitude, (3) thermal the substrate Protect from damage, etc.
[0006]
  In the case of a phase change optical disc, the dielectric layer is subjected to a large thermal stress because there is a process in which the recording film is heated to a melting point (for example, 600 ° C.) or higher during signal recording. Therefore, ZnS and SiO are used as dielectric materials with low internal stress and thermal stability.₂Mixed materials (hereinafter ZnS-SiO2)₂) Has been proposed (Proceedings of the 35th Joint Conference on Applied Physics 8P-ZQ-3, P839 (1988)). Since this material has a high refractive index, it is also suitable for increasing the absorption rate of laser light and for increasing the change in reflectance between amorphous and crystals or between crystals and crystals.
[0007]
  ZnS-SiO₂The mixed material has a microstructure of several tens of angstroms (several nm) of ZnS crystal in an amorphous state.₂It is confirmed that they are dispersed inside. The dielectric layer is generally formed by sputtering, but ZnS formed by sputtering is polycrystalline, and the recording characteristics change due to the change in crystal grain size due to the effect of heating by repeated recording. Or lead to thermal destruction of the thin film.₂It is considered that the ZnS crystal is prevented from growing by dispersing ZnS therein, and a stable dielectric material is obtained.
[0008]
  ZnS-SiO₂In addition to Ar gas, N is deposited by sputtering.₂It has been proposed that the addition of a small amount of gas further increases the thermal stability and improves the signal overwrite cycle (JP-A-3-232133). Furthermore, ZnS-SiO₂When forming a film by sputtering, N is added to Ar gas.₂Gas and O₂O in gas or Ar gas₂It has been proposed that the same effect can be obtained even when a small amount of gas is added (Japanese Patent Laid-Open No. 3-263627).
[0009]
[Problems to be solved by the invention]
  Since phase change optical disks reach high temperatures with recording operations, various heat-resistant protective layers have been studied. One solution is ZnS-SiO.₂It is a membrane. ZnS-SiO₂Since the internal stress is small and is thermally stable, the overwrite cycle is greatly improved compared to the dielectric materials that have been considered to be good. Furthermore, ZnS-SiO₂To Ar + N₂When the film is formed by sputtering in an atmosphere, the overwrite cycle is improved.
[0010]
  Where ZnS-SiO₂When forming a film by sputtering, Ar is added to O.₂If the film is formed in the added atmosphere, N is added to Ar.₂The overwrite cycle may be further improved as compared with an optical disk formed in an added atmosphere. However, it has been found that the thermal stability of the recording signal after the overwrite cycle is decreased. A possible reason for this is that ZnS-SiO is caused by the overwrite cycle.₂Gaseous O present in the film₂Is liberated and diffuses into the recording layer and combines with the constituent elements, and the characteristics of the recording layer are considered to change. In particular, when Ge provides heat resistance as in the Ge—Sb—Te system, ZnS—SiO₂Gaseous O present in the film₂Is bonded to Ge, the crystallization temperature of the recording film is lowered and the amorphous phase becomes unstable. Therefore, it is presumed that the CNR (signal-to-noise ratio) is lowered when exposed to a high temperature.
[0011]
  In order to solve the above-mentioned conventional problems, the present invention provides a highly reliable optical information recording medium that has excellent overwrite cycle characteristics and is thermally stable.the body'sAn object is to provide a manufacturing method.
[0012]
[Means for Solving the Problems]
  In order to achieve the above object, the method for producing an optical information recording medium of the present invention causes a reversible change between optically distinguishable states by irradiation with a laser beam, and contains at least Ge, Sb, and Te as constituent elements. Forming a recording layer including:InvitationIn contact with one main surface of the electrical recording layer and the recording layer,InvitationA step of forming a protective layer having a movement suppressing layer capable of suppressing the movement of oxygen constituting the electric body layer to the recording layer, and in the step of forming the protective layer, the rare gas and oxygen Sputtering a target containing Zn, S and Si in a mixed gas atmosphere containingInvitationAn electric layer is formed, and the movement suppression layer is formed by sputtering in a mixed gas atmosphere composed of a rare gas and nitrogen, and an oxygen component concentration in the mixed gas atmosphere containing the rare gas and oxygen is 0.1 vol. . % Or more and 10 vol. % Or lessThe material of the migration suppression layer is Ge nitrideA method for manufacturing an optical information recording medium.
[0013]
  In the method, the thickness of the recording layer is preferably in the range of 5 to 30 nm in order to perform stable recording.
[0014]
  In the method, a protective layer is preferably formed between the recording layer and the substrate.
[0015]
  In the method, the recording layer is preferably sandwiched between protective layers.
[0016]
  A preferable film thickness of the movement suppressing layer is in the range of 5 to 30 nm.
[0018]
  In the method, the laser beam incident side of the recording layer isA reflective layer on the other sideIt is preferable to provide.
[0019]
  Moreover, in the said method, it is preferable that the thickness of a reflection layer is 30 nm or more. This is to ensure the reflectance.
[0020]
  In the above method, the thickness of the dielectric layer provided between the substrate and the recording layer is preferably 30 nm or more. Although an upper limit is not specifically limited, Since it can serve as a board | substrate, it is to the thickness (usually 1.2 mm or less) of a board | substrate.
[0021]
  Moreover, in the said method, it is preferable that 0.1 to 10 vol.% Of nitrogen components are further included in mixed atmosphere.
[0022]
  In the method, the mixed atmosphere is preferably a mixed gas of a rare gas and air.
[0023]
  According to the present invention, at least one of the material and the material composition is different.InvitationA protective layer including an electric layer is provided on at least one main surface, and a recording layer including a material that causes a reversible change between optically identifiable states by irradiation of a laser beam is provided on the substrate, and the protective layer Of which are separated from the recording layerAbove invitationAn electric current layer, a target containing Zn, S and Si, a gas having at least an oxidizing action with a rare gas,IeOxygen componentTheBy having a step of forming a film by sputtering in a mixed atmosphere including the above, it is possible to realize a highly reliable optical information recording medium having excellent overwrite cycle characteristics of the phase change optical information recording medium and thermally stable. .
[0024]
  Of the protective layer, separated from the recording layerInvitationBy forming the electrical conductor layer by sputtering in a mixed gas atmosphere containing a rare gas and an oxygen component,InvitationThe oxygen content of the electrical layer can be controlled, and the migration caused by diffusion of oxygen released from the dielectric to the recording layer by the overwrite cycle can be suppressed, improving the heat resistance characteristics of the recording layer during the overwrite cycle. Thus, the life of the recording layer can be improved. In particular, when the recording layer contains Ge and Ge compensates the heat resistance of the recording layer, the oxidation of Ge due to oxygen transfer to the recording layer can be suppressed, and the heat resistance of the recording layer is maintained. Overwrite characteristics are improved.
[0025]
  It is preferable that the recording layer is sandwiched between the protective layers because the above-described effect becomes more reliable.
[0026]
  Separated from the recording layer of the protective layerInvitationWhen the mixed atmosphere for forming the electric layer changes in the film thickness direction and the content of the oxygen component increases as the distance from the recording layer increases, the dielectric material can have a continuous structure that does not exhibit a layer structure. Therefore, it is preferable.
[0027]
  Also,InvitationBetween the electrical layer and the recording layer,InvitationEither the constituent element of the electrical layer or the constituent element of the recording layer is the recording layer orInvitationAccording to the configuration provided with the movement suppressing layer that suppresses the movement to the electric body layer, the protective layerInvitationNot only the oxygen in the electrical layer, but also the protective layerInvitationSince the movement of constituent elements in either the electrical layer or the recording layer can be suppressed, the overwrite cycle characteristics can be improved.
[0028]
  In addition, as a material of the movement suppression layer, when applying any one of nitride, nitride oxide, or at least one of the constituent elements of Ge, Si, or the recording layer, compared to other movement suppression layers, For example, the constituent elements can be a barrier when diffusing, and the protective layerInvitationTrap oxygen released from the electrical layer andInvitationIt is preferable because the effect of suppressing the movement of constituent elements of the electric layer and / or the recording layer is remarkable, and particularly when Ge or Si nitride or nitride oxide is applied, the film quality is dense and heat resistant. preferable.
[0029]
  Further, the reflective layer is provided on the main surface side opposite to the substrate side of the recording layer, and in the configuration where the film thickness between the reflective layer and the recording layer is thinner than the film thickness between the recording layer and the substrate, the reflective layer The thermal conductivity of the layer between the recording layer and the recording layer is promoted, and the thermal stress generated by the overwrite cycle is suppressed, which is preferable.
[0030]
  With the above configuration, at least the recording layer is separatedInvitationThe electric conductor layer is made of ZnS and SiO.₂Sputtering of this mixture with a mixed gas of rare gas and oxygen increases the mechanical strength and improves the overwrite cycle. When exposed to a high temperature for a long time, the diffusion of oxygen into the recording film is suppressed and the reproduced signal light does not deteriorate. As a result, it is possible to provide a highly reliable optical information recording medium having particularly excellent overwrite cycle characteristics and excellent heat resistance characteristics of the phase change optical information recording medium.
[0031]
  The present invention can also be applied to a so-called double-sided bonding structure in which two substrates are arranged on the outside and two recording layers are arranged on the inner layer. In the case of this double-sided bonding structure, optical recording and reading can be performed from both the front and back directions.
[0032]
DETAILED DESCRIPTION OF THE INVENTION
  FIG. 1 shows an example of the structure of an optical information recording medium according to the present invention. Dielectric separated from the recording layer 4 on the substrate 1layerA protective layer A composed of 2 and a movement suppression layer 3, a recording layer 4, and a dielectric separated from the movement suppression layer 5 and the recording layer 4.layer6 in which the protective layer B and the reflective layer 7 are laminated in this order.
[0033]
  One of the requirements of the present invention is that the protective layer separated from the recording layerInvitationThe electrical layer is formed by sputtering a target containing Zn, S and Si in a mixed atmosphere containing a rare gas and at least an oxygen component.
[0034]
  As the substrates 1, 11, and 21 applied to the present invention, glass, resin, etc. can be used, but generally transparent glass, quartz, polycarbonate resin, polymethyl methacrylate resin, polyolefin resin, etc. .
[0035]
  The recording layers 4, 14, and 23 are phase change media, and a substance that causes an optically detectable state change between an amorphous and a crystal, or a crystal different from a crystal, can be applied. Specific materials include Te, An alloy of Se, Sb, In, Ge, etc., for example, Ge—Sb—Te, In—Sb—Te, Ga—Sb, Ge—Sb, In—Ge—Sb, In—Ga—Sb, Ge—Sn— Te, Ag-Sb-Te, and the like.
[0036]
  The reflection layers 7, 16, and 26 are not essential requirements for the configuration of the optical information recording medium obtained by the manufacturing method of the present invention as described above, but examples of the material include Au, Al, Ti, Ni, and Cr. It is composed of a simple substance or an alloy.
[0037]
  The target used in the present invention includes at least Zn, S, and Si, and the number of targets is preferably a multi-target that independently includes target constituent materials for adjusting the composition of the dielectric. In consideration of simplification or the like, a mixture of constituent materials is preferable and can be selected as appropriate. When using a mixture as a target, for example, ZnS and SiO₂And the like can be applied.
[0038]
  Further, He, Ne, Ar, or Xe can be applied alone or in combination as the rare gas applied in the mixed atmosphere of the present invention, and for example, oxygen molecules or ozone molecules can be applied as the oxygen component.
[0039]
  The protective layer of the optical information recording medium obtained by the production method of the present inventionInvitationSputtering by increasing the content of oxygen component in the mixed atmosphere as the electric conductor layer is separated from the recording layer can alleviate the migration of oxygen released from the dielectric to the recording layer regardless of the presence or absence of the movement suppression layer preferable.
[0040]
  The protective layer of the optical information recording medium obtained by the production method of the present inventionInvitationThe material of the electric layer includes Zn, S, and Si, and specific materials are mainly composed of ZnS and silicon oxide.
[0041]
  Protective layerInvitationIn the formation of the electric layer, the need to include an oxygen component in the mixed atmosphere is mainly an improvement in mechanical strength, and the recording characteristics themselves during the overwrite cycle are better when there are more oxygen components. If the amount of the component is too large, for example, if it is left in a high temperature atmosphere for a long time as an evaluation of the storage stability of the record after repeating the overwrite cycle,InvitationExcess oxygen in the electric material layer moves to the recording layer, which causes a problem that recording or / and reproducing characteristics of the recording layer change.
[0042]
  In order to achieve both the recording characteristics during the cycle and the storage stability after the cycle, the oxygen concentration of the oxygen component in the mixed atmosphere is in the range of 0.1 vol.% To 10 vol.%.Do.
[0043]
  The movement suppression layer is composed of a recording layer and a dielectric.layerOf the protective layerInvitationChanges in recording characteristics of the recording layer due to interlayer movement of constituent elements of the electrical conductor layer, particularly oxygen, are suppressed.
[0044]
  As the constituent material of the movement suppression layer, nitrides, nitride oxides, carbides, sulfides, fluorides, etc. of the constituent elements of the recording layer are provided. Si nitrides or nitride oxides are dense and heat resistant. In addition, since fluctuations in recording characteristics are particularly problematic in optical information recording media, the application of nitrides or nitride oxides of the constituent elements of the recording layer causes the constituent elements of the recording layer to be dielectric.layerIn particular, a Ge nitride or nitride oxide satisfies the above characteristics and is preferable because it can suppress the phenomenon of diffusion migration to the surface. Accordingly, for example, when Ge is included as a component responsible for the heat resistance of the recording layer, such as a Ge—Sb—Te-based recording layer, a configuration including Ge nitride or Ge nitride oxide as the movement suppression layer is used. preferable.
[0045]
  As a material for the movement suppressing layer, other than the above materials, for example, by adding any one of a dielectric material nitride, nitride oxide, carbide, sulfide, and fluoride, at least the movement of free oxygen in the dielectric can be performed. The effects that can be suppressedis there.
[0046]
  The atmosphere of the rare gas / oxygen component / nitrogen component can be achieved inexpensively and easily by mixing the rare gas and air, and desired by changing the air content appropriately according to the distance from the recording layer. The following characteristics can be obtained.
[0047]
  Hereinafter, the present invention will be described more specifically with reference to examples.
[0048]
  (referenceExample 1)
  A polycarbonate substrate with a diameter of 120 mm provided with a signal recording track as a substrate, and a ternary material (for example, Ge, Sb and Te) as a recording layer._2.0Sb_2.4Te_5.0), Al alloy (eg Al₉₈Cr₂) ZnS and SiO as upper and lower protective layers₂An optical disc was produced using the mixed material as a target. In order to protect the thin film layer of the optical disk, a resin coat was applied on the reflective layer. Here, the upper and lower protective layers have a two-layer structure formed by sputtering with different atmospheric gases.
[0049]
  Referring to FIG. 1, the thickness of each layer is 80 nm for the dielectric 2 of the protective layer A, 5 nm for the movement suppression layer 3, 17 nm for the recording layer 4, and 4 nm for the movement suppression layer 5 for the protective layer B from the substrate side. The dielectric 6 is 11 nm and the reflective layer 7 is 100 nm.
[0050]
  The protective layers A and B are formed with a sputtering power of 300 W and a sputtering atmosphere of Ar, O₂And N₂The gas mixture was formed by sputtering under the conditions of a flow rate of 20 sccm and a total pressure of 1 mTorr. The dielectric 2 of the protective layer A and the dielectric 6 of the protective layer B had an oxygen concentration in the range of 0 to 20 vol.%. The film was formed in an atmosphere of a mixed gas of oxygen and oxygen. Moreover, when forming the movement suppression layer 3 of the protective layer A and the movement suppression layer 5 of the protective layer B, an atmosphere of a mixed gas of argon and nitrogen having a nitrogen concentration of 2% was used.
[0051]
  The recording layer is a mixed target of Ge, Sb, and Te, and the sputtering layer is formed with a sputtering power of 80 W under a sputtering atmosphere of only argon gas at a flow rate of 20 sccm and a total pressure of 1 mTorr. The reflective layer is a mixed target of Al and Cr. The sputtering was performed in a sputtering atmosphere of only argon gas under the conditions of a flow rate of 20 sccm and a total pressure of 2 mTorr and a sputtering power of 200 W.
[0052]
  The manufactured optical disk was overwritten 10 times alternately with 5 MHz and 3 MHz while rotating at 10 m / s by a signal evaluation apparatus having an optical system with a laser wavelength of 680 nm and a numerical aperture (NA) of 0.55. After overwriting 10,000 times, the CNR (signal to noise ratio) of the 5 MHz signal was measured.
[0053]
  Further, after the heat resistance test in which the optical disk was left in dry nitrogen at 90 ° C. for 500 hours, the CNR of a track subjected to 500,000 overwrite cycles was measured.
[0054]
  The cycle characteristics and heat resistance characteristics of the optical disc were evaluated by defining the CNR as 50 dB or more as a standard.
[0055]
  Table 1 shows the evaluation results of the relationship between the oxygen concentration in the atmosphere when forming the dielectric 2 of the protective layer A and the dielectric 6 of the protective layer B, and the cycle characteristics and heat resistance characteristics.
[0056]
  When the oxygen concentration is smaller than 0.1 vol.%, The cycle characteristics are deteriorated, which is considered that the mechanical characteristics of the dielectric 2 and the dielectric 6 are not recovered.
[0057]
  On the other hand, when the oxygen concentration exceeds 10 vol.%, The cycle characteristics are good, but the heat resistance is deteriorated, and oxygen that passes through the movement suppression layer 3 and the movement suppression layer 5 and binds to the constituent elements in the recording layer. This is thought to be because the amount increases rapidly.
[0058]
  Therefore, it was confirmed that the oxygen concentration range in which good cycle characteristics and heat resistance characteristics can be obtained is 0.1 vol.% Or more and 10 vol.% Or less.
[0059]
[Table 1]

[0060]
  In this embodiment, argon is used as a rare gas component of the mixed gas. However, if an inert gas such as He, Ne, or Xe is used, the same effect can be obtained. Furthermore, in order to make use of the effect of mechanical strength obtained by mixing oxygen in a rare gas and sputtering, it is desirable that the dielectric layers 2 and 6 have a film thickness of 10 nm or more.
[0061]
  Also bookreferenceIn the example, if the film thicknesses of the movement suppression layers 3 and 5 are 3 nm or more, an effect of suppressing the diffusion of oxygen to the recording layer can be obtained.
[0062]
  (Reference example2)
  Reference example 1As the recording layer, using the same substrate asReference example 1As a ternary material consisting of Ge, Sb and Te, as a reflective layerReference example 1Al alloy, ZnS and SiO as upper and lower protective layers₂An optical disc was produced using the mixed material as a target. In order to protect the thin film layer of the optical disk, a resin coat was applied on the reflective layer. Here, the upper and lower protective layers have a two-layer structure formed by sputtering with different atmospheric gases.
[0063]
  Referring to FIG. 1, the thickness of each layer is 80 nm for the dielectric 2 of the protective layer A, 5 nm for the movement suppression layer 3, 17 nm for the recording layer 4, and 4 nm for the movement suppression layer 5 for the protective layer B from the substrate side. The dielectric 6 is 11 nm and the reflective layer 7 is 100 nm.
[0064]
  The protective layers A and B are formed with a sputtering power of 300 W and a sputtering atmosphere of Ar, O₂And N₂The mixed gas of 2 is a sputtering method under the conditions of a flow rate of 20 sccm and a total pressure of 1 mTorr. The dielectric layer 2 of the protective layer A and the dielectric layer 6 of the protective layer B have a nitrous oxide concentration range of 0 to 20 vol.%. The film was formed in an atmosphere of a mixed gas of argon and nitrous oxide. Moreover, when forming the movement suppression layer 3 of the protective layer A and the movement suppression layer 5 of the protective layer B, it was set as the atmosphere of the mixed gas of argon and nitrogen whose nitrogen concentration is 2 vol.%.
[0065]
  The recording layer is a mixed target of Ge, Sb, and Te, and the sputtering layer is formed with a sputtering power of 80 W under a sputtering atmosphere of only argon gas at a flow rate of 20 sccm and a total pressure of 1 mTorr. The reflective layer is a mixed target of Al and Cr. The sputtering was performed in a sputtering atmosphere of only argon gas under the conditions of a flow rate of 20 sccm and a total pressure of 2 mTorr and a sputtering power of 200 W.
[0066]
  The produced optical discReference example 1And evaluated in the same manner. Table 2 shows the evaluation results of the relationship between the nitrous oxide concentration in the atmosphere when forming the dielectric 2 of the protective layer A and the dielectric 6 of the protective layer B, and the cycle characteristics and heat resistance characteristics.
[0067]
  When the concentration of nitrous oxide is smaller than 0.1 vol.%, The cycle characteristics are deteriorated, which is considered that the mechanical characteristics of the dielectric 2 and the dielectric 6 are not recovered.
[0068]
  On the other hand, when the nitrous oxide concentration exceeds 15 vol.%, The cycle characteristics are good, but the heat resistance is deteriorated, and it passes through the movement suppression layer 3 and the movement suppression layer 5 and is bonded to the constituent elements in the recording layer. This is probably because the amount of oxygen increases rapidly.
[0069]
  Therefore, it was confirmed that the nitrous oxide concentration range in which good cycle characteristics and heat resistance characteristics can be obtained is 0.1 vol.% Or more and 15 vol.% Or less.
[0070]
[Table 2]

[0071]
  BookReference exampleIn FIG. 2, argon is used as a rare gas component of the mixed gas. However, if an inert gas such as He, Ne, or Xe is used, the same effect can be obtained.
[0072]
  Furthermore, in order to make use of the effect of mechanical strength obtained by mixing oxygen in a rare gas and sputtering, it is desirable that the dielectric layers 2 and 6 have a film thickness of 10 nm or more.
[0073]
  Also bookReference exampleIf the film thickness of the movement suppression layers 3 and 5 is 3 nm or more, the effect of suppressing the diffusion of oxygen to the recording layer can be obtained.
[0074]
  (Comparative Example 1)
  Reference example 1As the recording layer, using the same substrate asReference example 1As a ternary material consisting of Ge, Sb and Te, as a reflective layerReference example 1Al alloy similar to the above, ZnS and SiO as the upper and lower first and second dielectric layers₂An optical disc was produced using the mixed material as a target.
[0075]
  The thickness of each layer is 85 nm for the first dielectric layer, 17 nm for the recording layer, 15 nm for the second dielectric layer, and 100 nm for the reflective layer 7 from the substrate side. The deposition conditions for each layer are the same except for the sputtering atmosphere of the first and second dielectric layers.Reference example 1The same sputtering method was used. The sputtering atmosphere of the first dielectric layer and the second dielectric layer was a mixed gas of argon and nitrogen having a nitrogen concentration of 3%. In order to protect the thin film layer of the optical disc, a resin coat is applied on the reflective layer.Reference example 1It gave like.
[0076]
  This optical discReference example 1The cycle characteristics and heat resistance characteristics were evaluated in the same manner as in Table 3, and the results are shown in Table 3. As is apparent from Table 3, there is no change in CNR characteristics after 500,000 times overwriting and after 500,000 times overwriting, but after 500,000 times overwriting and after heat testing. Both CNRs are 48 dB below the reference value.
[0077]
  This is because the amount of gaseous oxygen liberated by the cycle from the first and second dielectric layers due to the addition of nitrogen is suppressed, so that before and after the heat resistance test due to oxidation of Ge in the recording layer. It shows that there is no characteristic change.
[0078]
  (Comparative Example 2)
  Reference example 1As the recording layer, using the same substrate asReference example 1As a ternary material consisting of Ge, Sb and Te, as a reflective layerReference example 1Al alloy similar to the above, ZnS and SiO as the upper and lower first and second dielectric layers₂An optical disc was produced using the mixed material.
[0079]
  The thickness of each layer is 85 nm for the first dielectric layer, 17 nm for the recording layer, 15 nm for the second dielectric layer, and 100 nm for the reflective layer 7 from the substrate side. The deposition conditions for each layer are the same except for the sputtering atmosphere of the first and second dielectric layers.Reference example 1The same sputtering method was used. The sputtering atmosphere of the first dielectric layer and the second dielectric layer was a mixed gas of argon and oxygen having an oxygen concentration of 3 vol.%. In order to protect the thin film layer of the optical disc, a resin coat is applied on the reflective layer.Reference example 1It gave like.
[0080]
  This optical discReference example 1The cycle characteristics and heat resistance characteristics were evaluated in the same manner as in Table 3, and the results are shown in Table 3. As is apparent from Table 3, the CNR after 500,000 cycles was as good as 54 dB, but the CNR after the heat test was reduced to 30 dB.
[0081]
  The addition of oxygen compensates for oxygen vacancies in the dielectric and improves the strength properties of the film, improving the cycle characteristics. However, the gaseous oxygen present in the film is liberated by the cycle. Therefore, it is considered that the heat resistance is deteriorated because the crystal temperature is lowered by bonding to Ge in the recording layer and the amorphous phase becomes unstable.
[0082]
  (Example 1)
  Reference example 1As the recording layer, using the same substrate asReference example 1As a ternary material consisting of Ge, Sb and Te, as a reflective layerReference example 1An optical disk was manufactured by providing two layers of protective layers A and B on the upper and lower sides of the same Al alloy and recording layer. In order to protect the thin film layer of the optical disk, a resin coat was applied on the reflective layer.
[0083]
  Referring to FIG. 1, the film thickness of each layer is 80 nm for the dielectric 2 of the protective layer A, 8 nm for the movement suppression layer 3 for the protective layer A, 17 nm for the recording layer 4 and the movement suppression for the protective layer B from the substrate side. Layer 5 is 8 nm, protective layer B dielectric 6 is 11 nm, and reflective layer 7 is 100 nm.
[0084]
  The deposition conditions for each layer are other than the protective layers A and B.Reference example 1The same sputtering method was used. Among the protective layers A and B, the sputtering atmosphere of the dielectric 2 and the dielectric 6 is a mixed gas of argon and oxygen having an oxygen concentration of 1 vol.%, The flow rate is 20 sccm, the total pressure is 1 mTorr, and the materials are ZnS and SiO.₂A sputtering film was formed with a sputtering power of 300 W using the above mixed material as a target. In addition, the movement suppression layer 3 and / or the movement suppression layer 5 of the protective layers A and B are made of Ge, and a mixed gas atmosphere of 20 vol.% Nitrogen and argon with a flow rate of 20 sccm and a total pressure of 5 mTorr and a sputtering power of 500 W. The film was formed by reactive sputtering under the conditions to form a Ge nitride thin film.
[0085]
  An optical disk manufactured by forming a Ge nitride oxide on both the protective layer A and the protective layer B is an optical disk A, and an optical disk manufactured by forming a Ge nitride oxide only on the movement suppression layer 3 of the protective layer A. An optical disk produced by depositing a Ge nitride oxide only in the movement suppressing layer 5 of the optical disk B and protective layer B is referred to as an optical disk C. Of the optical disks B and C, the remaining movement suppression layer 5 (optical disk B) or movement suppression layer 3 (optical disk C) is composed of ZnS and SiO in an atmosphere of a mixed gas of argon and nitrogen having a nitrogen concentration of 2 vol.₂The mixed material was sputtered to form a film. These optical discsReference example 1In the same manner as described above, the cycle characteristics and heat resistance characteristics were evaluated, and the results are shown in Table 3.
[0086]
  As shown in Table 3, good cycle characteristics and heat resistance characteristics were obtained for all of the optical disks A, B, and C. This is because the migration suppressing layer 3 of the protective layer A and / or the migration suppressing layer 5 of the protective layer B is made of Ge nitride oxide, and the dielectric 2 and / or protective layer B of the protective layer A is subjected to a heat resistance test. It is considered that oxygen liberated from the dielectric 6 is suppressed from diffusing into the recording layer.
[0087]
  In this embodiment, the constituent material of the movement suppression layer 3 and / or the movement suppression layer 5 is Ge nitride oxide. However, the constituent elements of the recording layer are nitride, nitride oxide, carbide, sulfide, fluoride, etc. As a result, the cycle characteristics and the heat resistance were improved as compared with the conventional ones. In particular, the nitride of Ge, the nitride or nitride of Si, or the nitride of the constituent element of the recording layer 5 was observed. Alternatively, when it is composed of nitrided oxide, good cycle characteristics and heat resistance characteristics were obtained.
[0088]
  In this embodiment, argon is used as a rare gas component of the mixed gas. However, if an inert gas such as He, Ne, or Xe is used, the same effect can be obtained.
[0089]
  Further, good cycle characteristics and heat resistance characteristics can be obtained when the oxygen concentration in the atmosphere during the formation of the dielectric 2 of the protective layer A and the dielectric 6 of the protective layer B is in the range of 0.1 to 10 vol.
[0090]
  (Reference example 3)
  Reference example 1As the recording layer, using the same substrate asReference example 1As a ternary material consisting of Ge, Sb and Te, as a reflective layerReference example 1An optical disk was manufactured by providing the same Al alloy, a protective layer A having a two-layer structure on the substrate side of the recording layer, and a single dielectric layer between the recording layer and the reflective layer. In order to protect the thin film layer of the optical disk, a resin coat was applied on the reflective layer.
[0091]
  Referring to FIG. 2, the thickness of each layer is 80 nm for the dielectric 12 of the protective layer A, 8 nm for the movement suppression layer 13, 17 nm for the recording layer 14, 15 nm for the dielectric layer 15, and the reflective layer 16 from the substrate side. Is 100 nm.
[0092]
  The film forming conditions for each layer are other than the protective layer A and the dielectric layer.Reference example 1The same sputtering method was used. The dielectric 12 of the protective layer A is composed of ZnS and SiO in an atmosphere of a mixed gas of argon and oxygen having an oxygen concentration of 3 vol.%.₂The mixed material was sputtered to form a film. The movement suppressing layer 13 and the dielectric layer 15 of the protective layer A are associated with each material.Example 1And performed under the same conditions.
[0093]
  The movement suppression layer 13 and the dielectric layer 15 of the protective layer A are made of ZnS and SiO in an atmosphere of a mixed gas of argon and nitrogen having a nitrogen concentration of 2 vol.₂An optical disk manufactured by sputtering a mixed material of the above is an optical disk D, a migration suppressing layer 13 of the protective layer A is formed of Ge nitride oxide, and the dielectric layer 15 is a mixed gas of argon and nitrogen having a nitrogen concentration of 2 vol.%. ZnS and SiO in the atmosphere₂An optical disk produced by sputtering a mixed material of the above is an optical disk E, and the movement suppression layer 13 of the protective layer A is made of ZnS and SiO in an atmosphere of a mixed gas of argon and nitrogen having a nitrogen concentration of 2 vol.%.₂The optical disk F is an optical disk manufactured by depositing the same Ge nitride oxide as the movement suppressing layer 13 of the optical disk E as the dielectric layer 15.
[0094]
  These optical discsReference example 1The cycle characteristics and heat resistance characteristics were evaluated in the same manner as in Table 3, and the results are shown in Table 3. As shown in Table 3, good cycle characteristics and heat resistance characteristics were obtained with any optical disk.
[0095]
  BookreferenceIn the example, the movement suppression layer 13 of the optical disk E and the dielectric layer 15 of the optical disk F are made of Ge nitride oxide. However, nitrides, nitride oxides, carbides, sulfides, fluorides, etc. of the constituent elements of the recording layer are also included. As a result of the examination, all of the cycle characteristics and heat resistance characteristics were improved as compared with the conventional ones. In particular, when various metal nitrides, oxides or fluorides were examined, Ge nitride, Si Good cycle characteristics and heat resistance characteristics were obtained when the nitride or nitride oxide of the recording layer 15 or the nitride or nitride oxide of the constituent element of the recording layer 15 was used.
[0096]
  Further, good cycle characteristics and heat resistance characteristics can be obtained when the oxygen concentration in the atmosphere during the formation of the dielectric 12 of the protective layer A is in the range of 0.1 to 10 vol.
[0097]
  In addition, bookreferenceIn the example, oxygen is used as the oxidizing gas in the rare gas. However, when nitrous oxide is used instead, the cycle characteristics and thermal characteristics are improved. In particular, when the concentration of nitrous oxide was in the range of 0.1 to 15 vol.%, Good cycle characteristics and heat resistance characteristics were obtained.
[0098]
  BookreferenceIn the example, argon is used as a rare gas component of the mixed gas. However, if an inert gas such as He, Ne, or Xe is used, the same effect can be obtained.
[0099]
  (Reference example4)
  Reference example 1As the recording layer, using the same substrate asReference example 1As a ternary material consisting of Ge, Sb and Te, as a reflective layerReference example 1An optical disk was manufactured by providing the same Al alloy, a protective layer A having a two-layer structure on the substrate side of the recording layer, and a single dielectric layer between the recording layer and the reflective layer. In order to protect the thin film layer of the optical disk, a resin coat was applied on the reflective layer.
[0100]
  Referring to FIG. 2, the thickness of each layer is 80 nm for the dielectric 12 of the protective layer A, 8 nm for the movement suppression layer 13, 17 nm for the recording layer 14, 15 nm for the dielectric layer 15, and the reflective layer 16 from the substrate side. Is 100 nm.
[0101]
  The film forming conditions for each layer are other than the protective layer A and the dielectric layer.Reference example 1The same sputtering method was used. The dielectric 12 and the dielectric layer 15 of the protective layer A are formed of ZnS and SiO in an atmosphere of a mixed gas of argon and oxygen having an oxygen concentration of 1 vol.₂The mixed material was sputtered to form a film, and the migration suppressing layer 13 was formed of Ge nitride oxide. Depending on the constituent materials of these protective layer A and dielectric layer,Example 1The film was formed under the same sputtering conditions.
[0102]
  This optical discReference example 1The cycle characteristics and heat resistance characteristics were evaluated in the same manner as in Table 3, and the results are shown in Table 3. As shown in Table 3, good cycle characteristics and heat resistance characteristics were obtained.
[0103]
  BookreferenceIn the example, the movement suppression layer 13 and the dielectric layer 15 of the protective layer A are made of Ge nitride oxide, but nitrides, nitride oxides, carbides, sulfides, fluorides, etc. of the constituent elements of the recording layer are also examined. As a result, the cycle characteristics and the heat resistance were improved as compared with the conventional ones. In particular, when various metal nitrides, oxides or fluorides were examined, the nitrides of Ge, Si When the nitride or nitride oxide, or the nitride or nitride oxide of the constituent element of the recording layer 15 is used, good cycle characteristics and heat resistance characteristics are obtained.
[0104]
  Also, good cycle characteristics and heat resistance characteristics can be obtained when the oxygen concentration in the atmosphere during the formation of the dielectric 12 and dielectric layer 15 of the protective layer A is in the range of 0.1 to 10 vol.
[0105]
  In addition, bookreferenceIn the example, oxygen is used as the oxidizing gas in the rare gas. However, when nitrous oxide is used instead, the cycle characteristics and thermal characteristics are improved. In particular, when the concentration of nitrous oxide was in the range of 0.1 to 15 vol.%, Good cycle characteristics and heat resistance characteristics were obtained.
[0106]
  In particular, although the dielectric layer 15 is in contact with the recording layer 14, the thickness is made thinner than that of the protective layer A (the dielectric 12 and the movement suppressing layer 13) and is in contact with the reflective layer 16, thereby dissipating heat. Therefore, it is presumed that good heat resistance can be obtained because there is little liberation of gaseous oxygen in the film due to cycle overwrite and the amount of oxygen diffusing into the recording layer at high temperatures is suppressed.
[0107]
  BookreferenceIn the example, argon is used as a rare gas component of the mixed gas. However, if an inert gas such as He, Ne, or Xe is used, the same effect can be obtained.
[0108]
  (Reference example5)
  Reference example 1As the recording layer, using the same substrate asReference example 1As a ternary material consisting of Ge, Sb and Te, as a reflective layerReference example 1An optical disk was manufactured by providing the same Al alloy, a single dielectric layer on the substrate side of the recording layer, and a protective layer B having a two-layer structure between the recording layer and the reflective layer. In order to protect the thin film layer of the optical disk, a resin coat was applied on the reflective layer.
[0109]
  Referring to FIG. 3, the thickness of each layer from the substrate side is 85 nm for the dielectric layer 22, 17 nm for the recording layer 23, 8 nm for the movement suppression layer 24 of the protective layer B, 11 nm for the dielectric 25, and the reflective layer 26. Is 100 nm.
[0110]
  The deposition conditions for each layer are as follows except for the protective layer A and the dielectric layer.Reference example 1The same sputtering method was used. The dielectric 25 of the protective layer B is made of ZnS and SiO in an atmosphere of a mixed gas of argon and oxygen having an oxygen concentration of 3 vol.%.₂The target is a mixed material of 2 and the flow rate is 20 sccm. Sputter deposition was performed under conditions of a total pressure of 1 mTorr and a sputtering power of 300 W.
[0111]
  The movement suppression layer 24 of the dielectric layer 22 and the protective layer B is formed of ZnS and SiO2 in an atmosphere of a mixed gas of argon and nitrogen having a nitrogen concentration of 2 vol.% At a flow rate of 20 sccm and a total pressure of 1 mTorr.₂An optical disk produced by sputtering under the condition of a sputtering power of 300 W using the above mixed material as a target is called an optical disk G. Further, the dielectric layer 22 is made of ZnS and SiO2 in an atmosphere of a mixed gas of argon and nitrogen having a nitrogen concentration of 2% at a flow rate of 20 sccm and a total pressure of 1 mTorr.₂Using the mixed material as a target, sputtering was performed under the condition of a sputtering power of 300 W, and the movement suppression layer 24 of the protective layer B wasExample 1An optical disk manufactured by forming a Ge nitride oxide film under the sputtering conditions described above is referred to as an optical disk H.
[0112]
  These optical discsReference example 1The cycle characteristics and heat resistance characteristics were evaluated in the same manner as in Table 3, and the results are shown in Table 3. As shown in Table 3, good cycle characteristics and heat resistance characteristics were obtained with any optical disk.
[0113]
  BookreferenceIn the example, the movement suppressing layer 24 of the protective layer B of the optical disk H is made of Ge nitride oxide, but the results of studying nitrides, nitride oxides, carbides, sulfides, fluorides, etc. of the constituent elements of the recording layer However, in both cases, improvement in cycle characteristics and heat resistance was observed compared to conventional ones. In particular, when various metal nitrides, oxides or fluorides were studied, Ge nitride, Si nitride In addition, when the recording element 23 is composed of a nitride or a nitrided oxide as a constituent element of the recording layer 23, good cycle characteristics and heat resistance characteristics are obtained.
[0114]
  Further, good cycle characteristics and heat resistance characteristics can be obtained when the oxygen concentration in the atmosphere during the formation of the dielectric 25 of the protective layer B is in the range of 0.1 to 10 vol.
[0115]
  BookreferenceIn the example, argon is used as a rare gas component of the mixed gas. However, if an inert gas such as He, Ne, or Xe is used, the same effect can be obtained.
[0116]
  Reference Examples 1 to 4 and Example 1Comparing optical disc E and optical disc F andReference example 3Is excellent in cycle characteristics and heat resistance after cycling, and is characterized in that the total number of layers is five and the number of manufacturing steps is small and simple.
[0117]
  (Reference Example 6)
  Reference example 1The dielectric 2 of the protective layer A and the dielectric 6 of the protective layer B have the same optical disc structure asReference example 1Instead of the mixed gas atmosphere of argon and oxygen, ZnS and SiO are mixed in a mixed gas atmosphere of argon, oxygen and nitrogen.₂The mixed material is used as a target, and a film is formed by sputtering. However, the oxygen concentration in the mixed gas is 3 vol.%, The nitrogen concentration is 1 vol.%, And the flow rate, total pressure, and sputtering power areReference example 1Is the same.
[0118]
  This optical discReference example 1When the cycle characteristics and heat resistance were evaluated by the same method as described above, good cycle characteristics and heat resistance were obtained as shown in Table 3. In this example,Reference example 1An optical disc structure similar to2,Example1Reference examples3Or reference example4In any of the optical disk structures, ZnS and SiO in an atmosphere of a mixed gas of argon and oxygen.₂By forming the protective layer dielectric or dielectric layer formed by sputtering the mixed material, good cycle characteristics and heat resistance characteristics were obtained.
[0119]
  Further, good cycle characteristics and heat resistance characteristics can be obtained when the oxygen concentration in the mixed gas of argon, oxygen, and nitrogen during film formation is in the range of 0.1 to 10 vol. In this embodiment, argon is used as a rare gas component of the mixed gas. However, if an inert gas such as He, Ne, or Xe is used, the same effect can be obtained.
[0120]
  (Reference Example 7)
  Reference example 1The dielectric 2 of the protective layer A and the dielectric 6 of the protective layer B have the same optical disc structure asReference example 1ZnS and SiO in the mixed gas atmosphere of argon and air instead of the mixed gas atmosphere of argon and oxygen₂The mixed material is sputtered to form a film. However, the ratio of argon and air in the mixed gas is 99: 3, and the flow rate, total pressure and sputtering power areReference example 1Is the same.
[0121]
  This optical discReference example 1When the cycle characteristics and heat resistance were evaluated by the same method as described above, good cycle characteristics and heat resistance were obtained as shown in Table 3.
[0122]
  In this example,Reference example 1An optical disc structure similar to2,Example1Reference examples3Or reference example4In any of the optical disk structures, ZnS and SiO in an atmosphere of a mixed gas of argon and oxygen.₂By forming the protective layer dielectric or dielectric layer formed by sputtering the mixed material, good cycle characteristics and heat resistance characteristics were obtained. However, the ratio of argon to air is preferably in the range of 99.9 to 0.1 to 95 to 5.
[0123]
  In this embodiment, argon is used as a rare gas component of the mixed gas. However, if an inert gas such as He, Ne, or Xe is used, the same effect can be obtained.
[0124]
  (Reference example8)
  Reference example 1As the recording layer, using the same substrate asReference example 1As a ternary material consisting of Ge, Sb and Te, as a reflective layerReference example 1ZnS and SiO as the upper and lower dielectric layers sandwiching the recording layer with the same Al alloy₂An optical disc having the same configuration as in Comparative Examples 1 and 2 was manufactured using the mixed material. In order to protect the thin film layer of the optical disk, a resin coat was applied on the reflective layer. The difference from Comparative Examples 1 and 2 is that the upper and lower dielectric layers have a single layer structure formed by sputtering in which the components of the atmospheric gas continuously change.
[0125]
  From the substrate side, the thickness of each layer is 85 nm for the first dielectric layer, 17 nm for the recording layer, 15 nm for the second dielectric layer, and 100 nm for the reflective layer. Of the film forming conditions for each layer, except for the first and second dielectric layers,Reference example 1The same sputtering method was used. The first and second dielectric layers are formed by sputtering in an atmosphere of a mixed gas of argon and oxygen having an oxygen concentration of 2 vol.% On the side opposite to the recording layer (substrate or reflective layer side). As the temperature approaches, the oxygen mixing ratio was gradually replaced with nitrogen, and the film was formed by sputtering in an atmosphere of a mixed gas of argon and nitrogen in the range of 2 vol.% On the side in contact with the recording layer.
[0126]
  This optical discReference example 1When the cycle characteristics and heat resistance were evaluated by the same method as described above, good cycle characteristics and heat resistance were obtained as shown in Table 3.
[0127]
  The oxygen concentration in the mixed gas in the atmosphere during film formation on the side of the first dielectric layer and the second dielectric layer in contact with the recording layer is in the range of 0 to 10 vol. Good cycle characteristics and heat resistance when the nitrogen concentration in the atmosphere during film formation on the opposite side of the dielectric layer and the second dielectric layer (substrate or reflective layer side) is in the range of 0-5 vol. Characteristics were obtained.
[0128]
  BookreferenceIn the example, argon is used as a rare gas component of the mixed gas. However, if an inert gas such as He, Ne, or Xe is used, the same effect can be obtained.
[0129]
[Table 3]

[0130]
【The invention's effect】
  As described above, according to the method for manufacturing an optical information recording medium of the present invention, the first dielectric layer is in contact with one main surface of the recording layer to form the first dielectric layer.Of oxygenMove to the recording layerTheIncluding a step of forming a protective layer having a migration suppression layer capable of being suppressed, and in this step, noble gas and nitrogenConsist ofForming the movement suppression layer by sputtering in a mixed atmosphere,The oxygen component concentration in the mixed gas atmosphere containing the rare gas and oxygen is 0.1. vol . % Or more 10 vol . % Or lessSoHigh mechanical strength, improved cycle characteristics, andThe oxygen contained in the first dielectric layer diffuses into the recording layer and combines with the constituent element Ge of the recording layer to change the characteristics of the recording layer.ButSuppressed optical information recording medium,That is, an optical information recording medium having excellent heat resistanceCan provide.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view showing an optical information recording medium according to an embodiment of the present invention.
[Figure 2]Reference exampleIt is a typical sectional view showing the optical information recording medium of.
[Fig. 3]Another reference exampleIt is a typical sectional view showing the optical information recording medium of.
[Explanation of symbols]
  1 Substrate
  2 Dielectric of protective layer A
  3 Movement suppression layer of protective layer A
  4 Recording layer
  5 Dielectric of protective layer B
  6 Movement suppression layer of protective layer B
  7 Reflective layer
  11 Substrate
  12 Dielectric of protective layer A
  13 Movement suppression layer of protective layer A
  14 Recording layer
  15 Dielectric layer
  16 Reflective layer
  21 Substrate
  22 Dielectric layer
  23 Recording layer
  24 Dielectric of protective layer B
  25 Movement inhibition layer of protective layer B
  26 Reflective layer

Claims (6)

Forming a recording layer containing at least Ge, Sb and Te as constituent elements, which causes a reversible change between optically distinguishable states by irradiation with a laser beam;
And dielectrics layer, in contact with one main surface of the recording layer to form a protective layer having a transfer inhibiting layer that allows suppress the movement to the recording layer of the oxygen constituting the induction conductor layer Process,
In the step of forming the protective layer, from in a mixed gas atmosphere containing a rare gas and oxygen, Zn, by sputtering a target containing S and Si was deposited the induction conductor layer, and a rare gas and nitrogen Forming the migration suppression layer by sputtering in a mixed gas atmosphere,
The oxygen component concentration in the mixed gas atmosphere containing the rare gas and oxygen is 0.1 vol. % Or more and 10 vol. % Ri Der below,
The method of manufacturing an optical information recording medium, wherein the material of the movement suppression layer is Ge nitride . The optical information recording medium includes a substrate,
The method for producing an optical information recording medium according to claim 1, wherein the protective layer is formed between the recording layer and the substrate. The optical information recording medium includes two protective layers,
2. The protective layer of one of the two protective layers is formed on one main surface side of the recording layer, and the other protective layer is formed on the other main surface side of the recording layer. Manufacturing method of optical information recording medium.   The method for producing an optical information recording medium according to claim 1, further comprising a reflective layer on a side opposite to the laser beam incident side of the recording layer. The method for manufacturing an optical information recording medium according to claim 4 , wherein the reflective layer has a thickness of 30 nm or more. The thickness of the dielectrics layer, method for manufacturing the optical information recording medium according to claim 2, wherein at 30nm or more.

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