JP4325150B2 - Transparent conductive film, method for forming transparent conductive film, and article having transparent conductive film - Google Patents

Description

〔一般式１及び２において、ＭはＩｎ、Ｓｎ、Ｚｎを表し、Ｒ₁、Ｒ₂はそれぞれ置換基を有していてもよいアルキル基、アリール基、アルコキシル基を表し、Ｒは水素原子、置換基を表し、また、ＲはＲ₁、Ｒ₂と結合して環を形成してもよい。Ｒ₃はそれぞれ置換基を有していてもよいアルキル基、アリール基を表す。ｎ₁は整数を表し、ｎ₂は整数を表す。〕
（７）反応性ガスが、酸化性ガスを含有していることを特徴とする上記（４）〜（６）のいずれか１項に記載の透明導電膜の形成方法。
（８）反応性ガスが、水、還元性ガスまたは酸化性ガスを含有していることを特徴とする上記（４）〜（６）のいずれか１項に記載の透明導電膜の形成方法。
（９）不活性ガスが、アルゴンまたはヘリウムであることを特徴とする上記（４）〜（８）のいずれか１項に記載の透明導電膜の形成方法。
【０００９】
（１０）電極間に印加する電界が周波数１００ｋＨｚ以上の高周波電界であり、且つ、１Ｗ／ｃｍ²以上の電力を供給して放電させることを特徴とする上記（４）〜（９）のいずれか１項に記載の透明導電膜の形成方法。
（１１）電極間に印加する電界が周波数１５０ＭＨｚ以下の高周波電界であることを特徴とする上記（１０）に記載の透明導電膜の形成方法。
（１２）電極間に印加する電界が周波数２００ｋＨｚ以上の高周波電界であることを特徴とする上記（１０）または（１１）に記載の透明導電膜の形成方法。
（１３）電極間に印加する電界が周波数８００ｋＨｚ以上の高周波電界であることを特徴とする上記（１０）〜（１２）のいずれか１項に記載の透明導電膜の形成方法。
（１４）電極間に供給する電力が、１．２Ｗ／ｃｍ²以上であることを特徴とする上記（１０）〜（１３）のいずれか１項に記載の透明導電膜の形成方法。
（１５）電極間に供給する電力が、５０Ｗ／ｃｍ²以下であることを特徴とする上記（１０）〜（１４）のいずれか１項に記載の透明導電膜の形成方法。
（１６）電極間に供給する電力が、２０Ｗ／ｃｍ²以下であることを特徴とする上記（１０）〜（１５）のいずれか１項に記載の透明導電膜の形成方法。
（１７）電極間に印加する高周波の電界が、連続したサイン波の電界であることを特徴とする上記（１０）〜（１６）のいずれか１項に記載の透明導電膜の形成方法。
（１８）前記電極の少なくとも一方が、誘電体で被覆されていることを特徴とする上記（４）〜（１７）のいずれか１項に記載の透明導電膜の形成方法。
（１９）誘電体が、比誘電率が６〜４５の無機物であることを特徴とする上記（１８）に記載の透明導電膜の形成方法。
（２０）電極の表面粗さＲｍａｘが１０μｍ以下であることを特徴とする上記（１８）または（１９）に記載の透明導電膜の形成方法。
【００１０】
（２１）基材の表面温度３００℃以下で基材上に導電膜を形成することを特徴とする上記（４）〜（２０）のいずれか１項に記載の透明導電膜の形成方法。
（２２）基材上に透明導電膜を形成した後、熱処理を行うことを特徴とする上記（４）〜（２１）のいずれか１項に記載の透明導電膜の形成方法。
（２３）熱処理が、空気雰囲気下で行われることを特徴とする上記（２２）に記載の透明導電膜の形成方法。
（２４）熱処理が、還元雰囲気下で行われることを特徴とする上記（２２）に記載の透明導電膜の形成方法。
（２５）熱処理が、酸化雰囲気下で行われることを特徴とする上記（２２）に記載の透明導電膜の形成方法。
（２６）熱処理が、真空雰囲気下で行われることを特徴とする上記（２２）に記載の透明導電膜の形成方法。
（２７）熱処理が、不活性ガス雰囲気下で行われることを特徴とする上記（２２）に記載の透明導電膜の形成方法。
（２８）熱処理の温度が５０から３００℃であることを特徴とする上記（２２）〜（２７）のいずれか１項に記載の透明導電膜の形成方法。
（２９）形成される透明導電膜が、Ｉｎ／Ｓｎ原子数比で１００／０．１〜１００／１５の範囲にあるＩＴＯ膜であることを特徴とする上記（４）〜（２８）のいずれか１項に記載の透明導電膜の形成方法。
（３０）形成される透明導電膜が、炭素含有量が０〜５．０原子数濃度の範囲にある透明導電膜であることを特徴とする上記（４）〜（２９）のいずれか１項に記載の透明導電膜の形成方法。
【００１１】
（３１）基材上に上記（４）〜（３０）のいずれか１項に記載の透明導電膜の形成方法によって形成された透明導電膜を有する物品。
（３２）基材が、透明樹脂フィルムであることを特徴とする上記（３１）に記載の物品。
（３３）透明樹脂フィルムが、タッチパネル用フィルム基板、液晶素子プラスチック基板、有機エレクトロルミネッセンス素子プラスチック基板、プラズマディスプレイパネル用電磁遮蔽フィルム、電子ペーパー用フィルム基板であることを特徴とする上記（３２）に記載の物品。
（３４）透明導電膜が、パターニングされた電極であることを特徴とする上記（３１）〜（３３）のいずれか１項に記載の物品。
によって達成される。
【００１２】
以下、本発明を詳細に説明する。
先ず、本発明の実質的に金属酸化物からなる透明導電膜であり、比抵抗が１×１０^-1Ω・ｃｍ以下で、かつ、ダイナミックＳＩＭＳで測定を行った際の水素イオンと主たる金属酸化物の金属由来の金属元素イオンのピーク強度比（水素／金属）（以下、本発明の水素イオンと金属元素イオンのピーク強度比ということがある。）が２から２０である透明導電膜（以下、本発明の透明導電膜という。）を詳細に説明する。
本発明において、本発明の水素イオンと金属元素イオンのピーク強度比は３から１５の範囲にすることが更に好ましく、特に好ましくは、４から８の範囲である。
【００１３】
本発明において、ダイナミックＳＩＭＳでの測定は表面分析実技シリーズ二次イオン質量分析法（日本表面科学会編 丸善２０００年発行）を参照して行われるが、本発明におけるダイナミックＳＩＭＳで測定を行った際の水素イオンと主たる金属酸化物の金属由来の金属元素イオンのピーク強度比（水素／金属）は以下の方法により求めることができる。
なお、本発明において、主たる金属酸化物とは、透明導電膜を主に構成する金属酸化物をいい、例えば、ドープ剤となる金属酸化物は含まれない。例えば、酸化インジウムにスズをドーピングして得られるＩＴＯ膜であれば、主たる金属酸化物とはインジュウムの酸化物を指し、ドーピングしたスズの酸化物は含まれない。
装置：Ｐｈｉｓｉｃａｌ Ｅｌｅｃｔｒｏｎｉｃｓ社製ＡＤＥＰＴ１０１０
一次イオン：Ｃｓ
一次イオン加速電圧：５ｋＶ
一次イオン電流：１００ｎＡ
一次イオン照射面積：４００μｍ
一次イオン入射角：６０°
取り込み範囲：４９％
負イオン検出
試料は測定チャンバー内で８時間保存した後に測定する。
上記条件にて膜厚の約１／３をエッチングした後、そこから膜厚の１／３がスパッタされるスパッタ時間における水素と主たる金属酸化物の信号を積算し、この積算値から水素イオンと主たる金属酸化物の金属由来の金属元素イオンのピーク強度比（水素／金属）を求める。
【００１４】
本発明の透明導電膜を形成するためには製膜時に水素を導入する方法、製膜後熱処理する等の方法で水素を除去する方法などが挙げられるが、特に限定されるものではない。
透明導電膜とは、光学的に透明で導電性を有する薄膜を指す。
透明導電膜は古くから研究開発が行われており、代表的な透明導電膜としては、Ｐｔ膜、Ａｕ膜、Ａｇ膜、Ｃｕ膜等の金属薄膜、ＳｎＯ₂膜、ＺｎＯ₂膜、Ｉｎ₂Ｏ₃膜などの酸化物膜及びこれら酸化物とドーパントを用いた複合酸化物膜（例えば、ＩＴＯ膜、ＩＺＯ膜、ＦＴＯ膜、ＡＴＯ膜）、カルコゲナイド膜、ＬａＢ₆膜、ＴｉＮ膜、ＴｉＣ膜等の非酸化物膜などが挙げられる。特に好ましくはＩＴＯ膜、ＩＺＯ膜である。
上記本発明の透明導電膜の形成方法は特に限定されるものではなく、大気圧プラズマＣＶＤ法、一般的なマグネトロンスパッタ法、ゾルゲル法などを用いることができるが、大気圧プラズマＣＶＤ法によって本発明の透明導電膜を形成することが好ましい。
大気圧プラズマＣＶＤ法を用いると透明導電膜形成条件の制御がしやすく、透過率が高く、優れた電気特性、高いエッチング速度を有する透明導電膜を安全に高い生産性で得ることができる
【００１５】
次に、本発明の大気圧または大気圧近傍の圧力下において、不活性ガスと反応性ガスからなる混合ガスを電極間の放電空間に導入してプラズマ状態とし、基材を前記プラズマ状態の反応性ガスに晒し、本発明の透明導電膜を形成する透明導電膜の形成方法（以下、本発明の透明導電膜の形成方法という。）を詳細に説明する。
本発明の透明導電膜の形成方法は、いわゆる大気圧プラズマＣＶＤ法を用いて本発明の透明導電膜を形成するものである。
以下、本発明の透明導電膜の形成方法で用いられる大気圧プラズマＣＶＤ法について説明する。
大気圧プラズマＣＶＤ法は、例えば、対向する電極間に、１００ｋＨｚ以上の高周波電界で、且つ、１００Ｗ／ｃｍ²以下の電力（出力密度）を供給し、反応性ガスを励起してプラズマを発生させる。
本発明において、電極間に印加する高周波電界の周波数は、好ましくは１００ｋＨｚまたはそれ以上、より好ましくは２００ｋＨｚ以上である。更に好ましくは８００ｋＨｚ以上である。また、１５０ＭＨｚ以下が好ましい。
また、電極間に供給する電力は、０．５Ｗ／ｃｍ²以上が好ましくは、より好ましくは１Ｗ／ｃｍ²以上である。更に好ましくは１．２Ｗ／ｃｍ²である。また、１００Ｗ／ｃｍ²以下が好ましく、より好ましくは５０Ｗ／ｃｍ²以下である。更に好ましくは２０Ｗ／ｃｍ²以下である。ここで電力とは、電極において放電が起こる範囲の単位面積（ｃｍ²）当りの電力を表す。
また、電極間に印加する高周波電界は、断続的なパルス波であっても、連続したサイン波であっても構わないが、本発明の効果を高く得るためには、連続したサイン波であることが好ましい。
【００１６】
本発明においては、このように電極間に電界を印加して、放電空間において反応性ガスをプラズマ状態とするが、放電空間において均一なグロー放電状態を保つことが好ましく、均一なグロー放電状態を保つことができる電極を採用したプラズマ放電処理装置を用いることが好ましい。
均一なグロー放電状態を保つ電極としては、金属母材上に誘電体を被覆した電極が好ましい。これらの金属母材上に誘電体を被覆した電極は、少なくとも対向する印加電極とアース電極の一方に用いられるが、対向する印加電極とアース電極の双方に用いることがさらに好ましい。
ここで用いる誘電体は、比誘電率が６〜４５の無機物であることが好ましく、このような誘電体としては、アルミナ、窒化珪素等のセラミックス、あるいは、ケイ酸塩系ガラス、ホウ酸塩系ガラス等のガラスライニング材等が挙げられる。
また、基材は電極間に載置してあるいは電極間を搬送してプラズマ状態の反応性ガスに晒される。電極間を搬送してプラズマ状態の反応性ガスに晒す場合、基材をロール電極に接して搬送することが行われるが、この場合、ロール電極を基材を接して搬送できるロール電極仕様にするだけでなく、更に、誘電体表面を研磨仕上げし、電極の表面粗さＲｍａｘ（ＪＩＳ Ｂ ０６０１）を１０μｍ以下にすることにより、誘電体の厚み及び電極間のギャップを一定に保つことができ、放電状態を安定化することができる。更に、熱収縮差や残留応力による歪やひび割れをなくし、かつ、ポーラスで無い高精度の無機誘電体を被覆することで耐久性を大きく向上させることができる。
【００１７】
これらの電極の作製において、高温下で金属母材に誘電体の被覆がなされるが、少なくとも透明導電膜を形成する基材と接する側の誘電体を研磨仕上げすること、更に、電極の金属母材と誘電体との熱膨張の差を小さくすることが必要であり、そのために、作製において、金属母材表面に、応力を吸収出来る層として泡混入量をコントロールした無機質の材料をライニングするとよい。特に、材質としては琺瑯等の溶融法により得られるガラスが好ましく、更に、導電性金属母材に接する最下層の泡混入量を２０〜３０ｖｏｌ％とし、次層以降を５ｖｏｌ％以下とすることで、緻密でかつひび割れ等が発生しない良好な電極を得ることができる。
また、電極の金属母材に誘電体を被覆する別の方法として、セラミックスの溶射を空隙率１０ｖｏｌ％以下で緻密に行い、更に、ゾルゲル反応により硬化する無機質の材料にて封孔処理を行う方法が挙げられる。ここでゾルゲル反応の促進には、熱硬化やＵＶ硬化を用いるのがよく、更に、封孔液を希釈し、コーティングと硬化を逐次で数回繰り返すと、より一層無機質化が向上し、劣化の無い緻密な電極ができる。
【００１８】
本発明の透明導電膜の形成方法に用いるプラズマ放電処理装置としては、従来用いられているプラズマ放電処理装置を用いることができるが、本発明に好ましく用いられる上記のような電極を有するプラズマ放電処理装置を図を用いて説明する。
図１〜図８はプラズマ放電処理装置におけるプラズマ放電処理容器及びそれに用いる電極を説明するためのものであって、該プラズマ放電処理容器においては、アース電極となるロール電極と、対向する位置に配置された印加電極となる固定電極との間で放電させ、当該電極間に反応性ガスを導入してプラズマ状態とし、ロール電極に巻回された長尺フィルム状の基材をこのプラズマ状態の反応性ガスに晒し、薄膜を形成する。
本発明において、透明導電膜の形成に用いられるプラズマ放電処理容器はこれに限定されるものではなく、大気圧または大気圧近傍の圧力下において、グロー放電を安定に維持し、透明導電膜を形成するための反応性ガスを励起してプラズマ状態とすることができるものであればいずれでもよい。
他の方式としては、基材を電極間ではない電極近傍に載置しあるいは搬送させ、別個に発生させたプラズマを当該基材上に吹き付けて薄膜の形成を行ういわゆるジェット方式等が挙げられる。
【００１９】
図１は、本発明の透明導電膜の形成方法に用いられるプラズマ放電処理装置に設置されるプラズマ放電処理容器の一例を示す概略図である。
図１において、長尺フィルム状の基材Ｆは搬送方向（図中、時計回り）に回転するロール電極２５に巻回されながら搬送される。固定されている電極２６は複数の円筒から構成され、ロール電極２５に対向させて設置される。ロール電極２５に巻回された基材Ｆは、ニップローラ６５、６６で押圧され、ガイドローラ６４で規制されてプラズマ放電処理容器３１によって確保された放電処理空間に搬送され、放電プラズマ処理される。次いで、ガイドローラ６７を介して次工程に搬送される。また、仕切板５４は前記ニップローラ６５、６６に近接して配置され、基材Ｆに同伴する空気がプラズマ放電処理容器３１内に進入するのを抑制する。
基材Ｆに同伴されてプラズマ放電処理容器３１内に持ち込まれる空気は、プラズマ放電処理容器３１内の気体の全体積に対し、１体積％以下に抑えることが好ましく、０．１体積％以下に抑えることがより好ましい。前記ニップローラ６５および６６により、それを達成することが可能である。
なお、放電プラズマ処理に用いられる混合ガス（不活性ガスと、反応性ガスである還元ガスおよび有機金属化合物）は、給気口５２からプラズマ放電処理容器３１に導入され、処理後のガスは排気口５３から排気される。
【００２０】
図２は、図１に示されたプラズマ放電処理容器とは異なる、本発明の透明導電膜の形成方法に用いられるプラズマ放電処理装置に設置されるプラズマ放電処理容器の他の一例を示す概略図である。
図１においては、電極として、ロール電極２５に対向する固定されている電極２６は円柱型の電極が用いられているのに対し、図２においては、電極として、ロール電極２５に対向する固定されている電極としては角柱型電極３６が用いられている。
図２に示した角柱型電極３６は、図１に示した円柱型の電極２６に比べて放電の範囲が広がるので、本発明の導電膜形成方法に好ましく用いられる。
図３は、図１及び図２に示された円筒型のロール電極の一例を示す概略図、図４は、同じく図１及び図２に示された円筒型のロール電極の他の一例を示す概略図、図５は、図１に示された円筒型で固定されている電極の一例を示す概略図、図６は、図１に示された円筒型で固定されている電極の他の一例を示す概略図、図７は、図２に示された角柱型で固定されている電極の一例を示す概略図、図８は、図２に示された角柱型で固定されている電極の他の一例を示す概略図である。
【００２１】
図３において、アース電極となるロール電極２５ｃは、金属等の導電性母材２５ａに対しセラミックスを溶射後、無機材料を用いて封孔処理したセラミック被覆処理誘電体２５ｂを被覆した組み合わせで構成されている。セラミック被覆処理誘電体２５ｂを片肉で１ｍｍ被覆し、ロール径を被覆後２００ｍｍφとなるように製作される。ロール電極２５ｃはアースされる。また、図４に示すように、金属等の導電性母材２５Ａへライニングにより無機材料を設けたライニング処理誘電体２５Ｂを被覆した組み合わせてロール電極２５Ｃを構成してもよい。ライニング材としては、ケイ酸塩系ガラス、ホウ酸塩系ガラス、リン酸塩系ガラス、ゲルマン酸塩系ガラス、亜テルル酸塩ガラス、アルミン酸塩ガラス、バナジン酸塩ガラス等が好ましく用いられるが、この中でもホウ酸塩系ガラスが加工し易いので、更に好ましく用いられる。金属等の導電性母材２５ａ、２５Ａの材料としては、銀、白金、ステンレス、アルミニウム、鉄等の金属等が挙げられるが、加工の観点からするとステンレスが好ましい。また、溶射に用いるセラミックス材としては、アルミナ・窒化珪素等が好ましく用いられるが、この中でもアルミナが加工し易いので、更に好ましく用いられる。
なお、実際に使用する形態においては、ロール電極の母材は、冷却水による冷却手段を有するステンレス製ジャケットを有するロール母材が使用される（不図示）。
【００２２】
図５及び図６は、図１に示す印加電極である固定された電極２６を、図７及び図８は、図２に示す固定された角柱型電極３６を説明するものであって、図５における固定の電極２６ｃ及び図７における電極３６ｃは、図３におけるロール電極２５ｃと同様に金属等の導電性母材２６ａ、３６ａに対しセラミックスを溶射後、無機材料を用いて封孔処理したセラミック被覆処理誘電体２６ｂ，３６ｂを被覆した組み合わせで構成されており、図６における固定の電極２６Ｃ及び図７における電極３６Ｃは、図３におけるロール電極２５ｃと同様に金属等の導電性母材２６Ａ、３６Ａへライニングにより無機材料を設けたライニング処理誘電体２６Ｂ、３６Ｂを被覆した組み合わせて電極２６Ｃ、３６Ｃを構成している。
なお、実際に使用する形態においては、電極の母材とし中空のステンレスパイプが使用されており（不図示）、セラミック被覆処理誘電体を被覆した後の直径は１２ｍｍまたは１５ｍｍとなるように製作される。また、当該固定電極は、上記ロール電極の周囲に沿って１４本設置している。
電極に印加する電源は、特に限定はないが、パール工業製高周波電源（２００ｋＨｚ）、パール工業製高周波電源（８００ｋＨｚ）、日本電子製高周波電源（１３．５６ＭＨｚ）、パール工業製高周波電源（１５０ＭＨｚ）等が使用できる。
【００２３】
図９は、本発明の透明導電膜の形成方法に用いられるプラズマ放電処理装置の一例を示す概念図である。
図９において、プラズマ放電処理容器３１は図２に記載のプラズマ放電処理容器と同じ構成になっている。
また、反応性ガス発生装置５１、電源４１、電極冷却ユニット６０、ポンプＰ等が装置構成として配置されている。電極冷却ユニット６０の冷却剤としては、蒸留水、油等の絶縁性材料が用いられる。
図９に記載の電極２５、３６は、図３〜図８に示した電極と同様であり、対向する電極間のギャップは、例えば、１ｍｍ程度に設定される。
電極間距離は、電極の母材に設置した固体誘電体の厚さ、印加電圧の大きさ、プラズマを利用する目的等を考慮して決定される。
電極の一方に固体誘電体を設置した場合の固体誘電体と電極の最短距離、電極の双方に固体誘電体を設置した場合の固体誘電体同士の距離としては、いずれの場合も均一な放電を行せるという観点から０．５ｍｍ〜２０ｍｍが好ましく、特に好ましくは１ｍｍ±０．５ｍｍである。
プラズマ放電処理容器３１内にロール電極２５、固定されている電極３６を所定位置に配置し、反応性ガス発生装置５１で発生させた混合ガスを流量制御して、給気口５２よりプラズマ放電処理容器３１内に導入し、プラズマ放電処理容器３１内をプラズマ処理に用いる混合ガスで充填する。使用済の反応性ガスは排気口５３より排気される。
次に、ロール電極２５はアースし、電源４１により電極３６に電圧を印加して放電プラズマを発生させる。ここで基材Ｆはロール状の元巻き基材６１より供給される。供給された基材Ｆはガイドローラ６４により導かれ、プラズマ放電処理容器３１内の電極間を、ロール電極２５に接触した状態で搬送され、搬送中に放電プラズマにより表面が放電処理され、その後にガイドローラ６７に導かれ、次工程に搬送される。ここで、基材Ｆはロール電極２５に接触している側の反対の面のみに導電膜が形成される。
電源４１より固定されている電極３６に印加する電圧は適宜決定されるが、例えば、電圧は０．５〜１０ｋＶ程度、電源周波数は０．５ｋＨｚ以上１５０ＭＨｚ以下に調整される。ここで電源の印加法に関しては、連続モードといわれる連続サイン波状の連続発振モードとパルスモードといわれる断続的にＯＮ／ＯＦＦを行う断続発振モードのどちらを採用してもよいが、連続モードの方がより緻密で良質な膜が得られる。
【００２４】
プラズマ放電処理容器３１にはパイレックス（Ｒ）ガラス製の容器等が好ましく用いられるが、電極との絶縁がとれれば金属製の容器を用いることも可能であり、例えば、アルミニウム、ステンレスのフレームの内面にポリイミド樹脂等を張り付けた容器、金属フレームにセラミックス溶射を行い絶縁性を持たせた容器が用いられる。
また、放電プラズマ処理時の基材表面の温度は特に制限はない。基材としてガラスを用いる場合は３００℃以下、高分子を用いる場合は２００℃以下が好ましい。上記の温度範囲に調整するために、必要に応じて電極、基材を冷却手段で冷却することができる。
本発明においては、上記の放電プラズマ処理が大気圧または大気圧近傍で行われるが、ここで大気圧近傍とは、２０ｋＰａ〜１１０ｋＰａの圧力をいい、本発明の効果を好ましく得るためには、９３ｋＰａ〜１０４ｋＰａが好ましい。
また、本発明の導電膜形成方法に用いる放電用電極においては、少なくとも基材と接する側の電極表面のＪＩＳ Ｂ ０６０１で規定される表面粗さの最大高さ（Ｒｍａｘ）が１０μｍ以下になるように調整することが、本発明に記載の効果を得る観点から好ましいが、更に好ましくは、表面粗さの最大値を８μｍ以下、特に好ましくは、７μｍ以下に調整することである。
また、ＪＩＳ Ｂ ０６０１で規定される中心線平均表面粗さ（Ｒａ）は０．５μｍ以下が好ましく、更に好ましくは０．１μｍ以下である。
【００２５】
次に、本発明の導電膜形成方法に用いられる不活性ガスと反応性ガスからなる混合ガスについて説明する。
混合ガスにおいて、反応性ガスは基材上に設けたい透明導電膜の種類によって異なるが、不活性ガスとの混合ガスとして透明導電膜を形成するためにプラズマ状態となる。
本発明の混合ガスにおける不活性ガスとしては、周期表の第１８属元素、具体的には、ヘリウム、ネオン、アルゴン、クリプトン、キセノン、ラドン、更には、窒素ガス等の反応にあずからないガスが挙げられるが、本発明に記載の効果を得るためには、アルゴンまたはヘリウムが特に好ましい。
本発明の混合ガスにおける反応性ガスは複数用いることが可能であるが、少なくとも１種類は、放電空間でプラズマ状態となり、透明導電膜を形成する成分を含有するものである。透明導電膜を形成する成分を含有する反応性ガスは特に制限はないが、有機金属化合物（以下、本発明の有機金属化合物ということがある。）が好ましく用いられる。これら本発明の有機金属化合物は透明導電膜を形成し、気化するものであれば特に種類は問わないが、分子内に酸素を有する有機金属化合物が好ましい。
これら本発明の有機金属化合物としては、βジケトン金属錯体、金属アルコキシド、アルキル金属等の有機金属化合物を用いることができるが、特に好ましい本発明の有機金属化合物は、以下の一般式１または一般式２で表される有機金属化合物である。
【００２６】
【化３】

〔一般式１及び２において、ＭはＩｎ、Ｓｎ、Ｚｎを表し、Ｒ₁、Ｒ₂はそれぞれ置換基を有していてもよいアルキル基、アリール基、アルコキシル基を表し、Ｒは水素原子、置換基を表し、また、ＲはＲ₁、Ｒ₂と結合して環を形成してもよい。Ｒ₃はそれぞれ置換基を有していてもよいアルキル基、アリール基を表す。ｎ₁は整数を表し、ｎ₂は整数を表す。〕
Ｒ₁、Ｒ₂、Ｒ₃で表される置換基を有していてもよいアルキル基としては炭素数１から１０までのアルキル基が好ましく、Ｒ、Ｒ₁、Ｒ₂、Ｒ₃の置換基としてはフッ素原子が好ましい。
一般式１で表される有機金属化合物を形成する配位子の具体例としては、以下に示す化合物が挙げられる。
【００２７】
【化４】

【００２８】
【化５】

また、下記のジケトン化合物も配位子として好ましい。
【００２９】
【化６】

【００３０】
一般式１及び２におけるＭとしてはインジウム（Ｉｎ）が好ましい。
本発明の有機金属化合物の中で好ましい例としては、インジウムヘキサフルオロペンタンジオネート、インジウムメチル（トリメチル）アセチルアセテート、インジウムアセチルアセトナート、インジウムイソポロポキシド、インジウムトリフルオロペンタンジオネート、トリス（２，２，６，６−テトラメチル３，５−ヘプタンジオネート）インジウム、ジ−ｎ−ブチルビス（２，４−ペンタンジオネート）スズ、ジ−ｎ−ブチルジアセトキシスズ、ジ−ｔ−ブチルジアセトキシスズ、テトライソプロポキシスズ、テトラブトキシスズ、ジンクアセチルアセトナート等を挙げることができる。
この中で特に好ましいのはインジウムアセチルアセトナート、トリス（２，２，６，６−テトラメチル３，５−ヘプタンジオネート）インジウム、ジンクアセチルアセトナート、ジ−ｎ−ブチルジアセトキシスズである。これらの有機金属化合物は一般に市販されており、例えば、インジウムアセチルアセトナートは東京化成工業（株）から容易に入手することができる。
【００３１】
本発明においては、透明導電膜を形成する成分を含有する反応性ガスと共に、導電膜の導電性を向上させるためにドーピング剤を反応ガスとして含有させることができる。これらドーピング剤としては、例えば、アルミニウムイソプロポキシド、ニッケルアセチルアセトナート、マンガンアセチルアセトナート、ボロンイソプロポキシド、ｎ−ブトキシアンチモン、トリ−ｎ−ブチルアンチモン、ジ−ｎ−ブチルビス（２，４−ペンタンジオネート）スズ、ジ−ｎ−ブチルジアセトキシスズ、ジ−ｔ−ブチルジアセトキシスズ、テトライソプロポキシスズ、テトラブトキシスズ、テトラブチルスズ、ジンクアセチルアセトナート、６フッ化プロピレン、８フッ化シクロブタン、４フッ化メタン等を挙げることができる。
さらに、本発明においては、水を反応ガスとして用いることで、高い電導性と大きなエッチング速度を有する透明導電膜を形成することができる。反応ガス中に混入する水の量は気体として混合ガスの０．０００１〜１０体積％の範囲にあることが好ましい。より好ましくは０．００１〜１体積％の範囲にあることが好ましい。
また、反応ガスとして、酸素などの酸化性のガス、水素などの還元性のガス、その他、一酸化窒素、二酸化窒素、一酸化炭素、二酸化炭素などを用いることもできる。
【００３２】
透明導電膜を形成する成分を含有する反応性ガスとドーピングを目的に用いられる反応ガスの量比は、形成する透明導電膜の種類により異なる。例えば、酸化インジウムにスズをドーピングして得られるＩＴＯ膜においては、得られるＩＴＯ膜のＩｎ／Ｓｎの原子数比が１００／０．１〜１００／１５の範囲になるように反応性ガスの量比を調整する。好ましくは、１００／０．５〜１００／１０の範囲になるよう調整する。Ｉｎ／Ｓｎの原子数比はＸＰＳ測定により求めることができる、また、酸化錫にフッ素をドーピングして得られるＦＴＯ膜においては、得られるＦＴＯ膜のＳｎ／Ｆの原子数比が１００／０．０１〜１００／５０の範囲になるよう反応性ガスの量比を調整する。Ｓｎ／Ｆの原子数比はＸＰＳ測定により求めることができる。また、Ｉｎ₂Ｏ₃−ＺｎＯ系アモルファス透明導電膜においては、得られるＩｎ／Ｚｎの原子数比が１００／５０〜１００／５の範囲になるよう反応性ガスの量比を調整する。Ｉｎ／Ｚｎの原子数比はＸＰＳ測定で求めることができる。
更に、形成される透明導電膜の抵抗値を調整するために反応性ガスを追加することも可能である。透明導電膜の抵抗値を調整するために用いる反応性ガスとしては、例えば、チタントリイソプロポキシド、テトラメトキシシラン、テトラエトキシシラン、ヘキサメチルジシロキサン等を挙げることができる。
透明導電膜の膜厚は、通常の場合、０．１ｎｍ〜１０００ｎｍの範囲とするのが好ましい。
【００３３】
本発明の透明導電膜の形成方法において、プラズマ状態の反応性ガスに晒し、基材上に透明導電膜を形成した後、熱を加え熱処理することにより透明導伝膜の特性を調整することができるので熱処理することが好ましい。透明導電膜膜中の水素の量はこの熱処理によっても調整することができる。
熱処理の温度は５０〜３００℃の範囲が好ましく、さらに好ましくは１００〜２００℃の範囲である。加熱の雰囲気には特に制限はなく、空気雰囲気、水素などの還元性ガスを含有する還元雰囲気、酸素などの酸化性ガスを含有する酸化雰囲気、あるいは、真空、不活性ガス雰囲気うちから適宜選択することができる。還元雰囲気、酸化雰囲気である場合、還元性ガス、酸化性ガスは希ガスや窒素などの不活性ガスで希釈して用いることが好ましい。この場合、還元性ガス、酸化性ガスの濃度は０．０１から５％が好ましく、より好ましくは０．１から３％である。
また、本発明の透明導電膜の形成に反応性ガスとして有機金属化合物を用いる場合、得られる透明導電膜は、微量の炭素を含有する場合があるが、炭素含有率は、０〜５．０原子数濃度の範囲内にあることが好ましい。特に、０．０１〜３原子数濃度の範囲内にあることが好ましい。
本発明の透明導電膜の形成方法に用いることができる基材しては、フィルム状のもの、シート状のもの、レンズ状等の立体形状のもの等、透明導電膜をその表面に形成できるものであれば特に限定はない。
これら基材は、電極間に載置できるものであれば電極間に載置することによって、基材が電極間に載置できないものであれば発生したプラズマを当該基材に吹き付けることによって導電膜の形成を行うことができる。
【００３４】
基材を構成する材料も特に限定はない。ガラスを用いることも可能であるが、大気圧または大気圧近傍の圧力下であることと、低温のグロー放電でプラズマ状態にすることができるので、樹脂フィルム等の樹脂材料にも導電膜を形成することができる。
これら樹脂フィルムとしては、例えば、フィルム状としたセルローストリアセテート等のセルロースエステル、ポリエステル、ポリカーボネート、ポリスチレン、更にこれらの上にゼラチン、ポリビニルアルコール（ＰＶＡ）、アクリル樹脂、ポリエステル樹脂、セルロース系樹脂等を塗設したものなどを使用することができる。
また、これら基材には、防眩層、クリアハードコート層、バックコート層、帯電防止層などを塗設した基材も含まれる。
具体的には、ポリエチレンテレフタレート、ポリエチレンナフタレート等のポリエステルフィルム、ポリエチレンフィルム、ポリプロピレンフィルム、セロファン、セルロースジアセテートフィルム、セルロースアセテートブチレートフィルム、セルロースアセテートプロピオネートフィルム、セルロースアセテートフタレートフィルム、セルローストリアセテートフィルム、セルロースナイトレートフィルム等のセルロースエステル類またはそれらの誘導体からなるフィルム、ポリ塩化ビニリデンフィルム、ポリビニルアルコールフィルム、エチレンビニルアルコールフィルム、シンジオタクティックポリスチレン系フィルム、ポリカーボネートフィルム、ノルボルネン樹脂系フィルム、ポリメチルペンテンフィルム、ポリエーテルケトンフィルム、ポリイミドフィルム、ポリエーテルスルホンフィルム、ポリスルホン系フィルム、ポリエーテルケトンイミドフィルム、ポリアミドフィルム、フッ素樹脂フィルム、ナイロンフィルム、ポリメチルメタクリレートフィルム、アクリル系フィルムあるいはポリアリレート系フィルム等を挙げることができる。
【００３５】
上記のフィルムの素材は単独であるいは適宜混合されて使用することもできる。中でも、ゼオネックス（日本ゼオン（株）製）、ＡＲＴＯＮ（日本合成ゴム（株）製）などの市販品を好ましく使用することができる。更に、ポリカーボネート、ポリアリレート、ポリスルフォン及びポリエーテルスルフォンなどの固有複屈折率の大きい素材であっても、溶液流延、溶融押し出し等の条件、更には縦、横方向に延伸条件等を適宜設定することにより使用することができる。
以上、本発明の透明導電膜の形成方法に用いられる基材について説明したが、本発明において用いられる基材は、これらの記載によって限定されるものではない。
また、上記のフィルム状の基材としては、１０μｍ〜１０００μｍの膜厚のものが好ましく用いられる。
また、本発明によって導電膜を形成する場合、必要に応じて、基材と透明導電性膜の間に接着性を向上させるために接着層を設けてもよい。また、光学特性を改良するために、透明導電膜を設けた面の反対の面に反射防止膜を設けることもできる。さらに、フィルムの最外層に防汚層を設けることも可能である。その他、必要に応じてガスバリア性、耐溶剤性を付与するための層等を設けることもできる。
これらの層の形成方法は特に限定はなく、塗布法、真空蒸着法、スパッタリング法、大気圧プラズマＣＶＤ法等を用いることができる。特に好ましいのは大気圧プラズマＣＶＤ法である。
これらの層の大気圧プラズマＣＶＤによる形成方法、例えば、反射防止膜の形成方法としては、特願２０００−０２１５７３号公報等に開示された方法を用いることができる。
本発明においては、透明導電膜を設ける場合、透明導電膜の膜厚偏差は平均膜厚の±１０％になるように設けることが好ましく、更に好ましくは±５％以内にすることであり、特に好ましくは±１％以内になるようすることでる。
【００３６】
【実施例】
以下に、本発明を実施例により具体的に説明するが、本発明はこれらの実施例によって限定されるものではない。
（実施例１−１）
基材として膜厚約５０ｎｍのシリカ膜をアルカリバリアコートとして設けたガラス基板（５０ｍｍ×５０ｍｍ×１ｍｍ）を用意した。
プラズマ放電装置には、電極が平行平板型のものを用い、この電極間に上記ガラス基板を載置した。
なお、アース（接地）電極としては、２００ｍｍ×２００ｍｍ×２ｍｍのステンレス板に高密度、高密着性のアルミナ溶射膜を被覆し、その後、テトラメトキシシランを酢酸エチルで希釈した溶液を塗布乾燥後、紫外線照射により硬化させ封孔処理を行い、このようにして被覆した誘電体表面を研磨し、平滑にして、Ｒｍａｘ ５μｍとなるように加工した電極を用いた。また、印加電極としては、中空の角型の純チタンパイプに対し、誘電体をアース電極と同様の条件にて被覆した電極を用いた。印加電極は複数作成し、アース電極に対向して設け放電空間を形成した。
また、プラズマ発生に用いる電源としては、日本電子（株）製高周波電源ＪＲＦ−１００００を用い、周波数１３．５６ＭＨｚで、５Ｗ／ｃｍ²の電力を供給した。
電極間に以下の組成の混合ガスを流し、プラズマ状態とし、上記のガラス基板を大気圧プラズマ処理し、ガラス基板上に錫ドープ酸化インジウム膜を作成した。
―混合ガス組成―
不活性ガス：ヘリウム ９８．７４体積％
反応性ガス１：水 ０．０１体積％（気体として）
反応性ガス２：インジウムアセチルアセトナト １．２体積％
反応性ガス３：ジブチル錫ジアセテート ０．０５体積％
【００３７】
作成した錫ドープ酸化インジウム膜を以下の方法で評価した。
＜透過率＞
ＪＩＳ−Ｒ−１６３５に従い、日立製作所製分光光度計Ｕ−４０００型を用いて測定を行った。試験光の波長は５５０ｎｍとした。
＜膜厚、製膜速度＞
膜厚はＰｈｏｔａｌ社製ＦＥ−３０００反射分光膜厚計により測定し、得られた膜厚をプラズマ処理時間で徐したものを製膜速度とした。
＜抵抗率＞
ＪＩＳ−Ｒ−１６３７に従い、四端子法により求めた。なお、測定には三菱化学製ロレスタ−ＧＰ、ＭＣＰ−Ｔ６００を用いた。
【００３８】
＜炭素含有率の測定＞
膜組成、炭素含有率は、ＸＰＳ表面分析装置としてＶＧサイエンティフィックス社製ＥＳＣＡＬＡＢ−２００Ｒを用いて測定した。測定は、Ｘ線アノードにＭｇを用い、出力６００Ｗ（加速電圧１５ｋＶ、エミッション電流４０ｍＡ）で行った。エネルギー分解能は、清浄なＡｇ３ｄ５／２ピークの半値幅で規定したとき、１．５〜１．７ｅＶとなるように設定した。
測定を行う前に、汚染による影響を除くために、薄膜の膜厚の１０〜２０％の厚さに相当する表面層をエッチング除去した。表面層の除去にはＡｒイオンエッチングを用いた。
先ず、結合エネルギー０ｅＶから１１００ｅＶの範囲を、データ取り込み間隔１．０ｅＶで測定し、いかなる元素が検出されるかを求めた。
次に、検出された、エッチングイオン種を除く全ての元素について、データの取り込み間隔を０．２ｅＶとして、その最大強度を与える光電子ピークについてナロースキャンを行い、各元素のスペクトルを測定した。得られたスペクトルは、測定装置、あるいは、コンピューターの違いによる含有率算出結果の違いを生じせしめなくするために、ＶＡＭＡＳ−ＳＣＡ−ＪＡＰＡＮ製のＣＯＭＭＯＮ ＤＡＴＡ ＰＲＯＣＥＳＳＩＮＧ ＳＹＳＴＥＭ（Ｖｅｒ．２．３以降が好ましい。）上に転送した後、同ソフトで処理を行い、炭素含有率の値を原子数濃度（ａｔｏｍｉｃ ｃｏｎｃｅｎｔｒａｔｉｏｎ：ａｔ％）として求めた。
また、錫とインジウムの比（Ｉｎ／Ｓｎ比）も、上記結果から得られた原子数濃度の比として求めた。
また、定量処理をおこなう前に、各元素についてＣｏｕｎｔ Ｓｃａｌｅのキャリブレーションを行い、５ポイントのスムージング処理を行った。定量処理では、バックグラウンドを除去したピークエリア強度（ｃｐｓ×ｅＶ）を用いた。バックグラウンド処理には、Ｓｈｉｒｌｅｙ法を用いた。
Ｓｈｉｒｌｅｙ法については、Ｄ．Ａ．Ｓｈｉｒｌｅｙ，Ｐｈｙｓ．Ｒｅｖ．，Ｂ５，４７０９（１９７２）を参考にすることができる。
【００３９】
＜水素イオンと主たる金属酸化物の金属由来の金属元素イオンのピーク強度比（水素／金属）（Ｈ／Ｍ比）＞
先に説明した二次イオン質量分析法によりＨ／Ｍ比を求めた。
＜エッチング速度＞
水：濃塩酸：４０％ＦｅＣｌ₃水溶液を８１：８：７重量％で混合したエッチング液を３０℃に加温し、その中に錫ドープ酸化インジウム膜を形成した試料を浸し、膜の除去を目視によって評価した。１分以内に錫ドープ酸化インジウム膜が除去できるたものを○、１分以上浸して除去できるものを△、３分浸しても残さが残るものを×とした。
（実施例１−２）
実施例１−１において、混合ガスとして以下に組成の混合ガスを用いた以外は実施例１−１と同様にして錫ドープ酸化インジウム膜を作成した。
―混合ガス組成―
不活性ガス：ヘリウム ９８．７体積％
反応性ガス１：水 ０．０５体積％（気体として）
反応性ガス２：インジウムアセチルアセトナト １．２体積％
反応性ガス３：ジブチル錫ジアセテート ０．０５体積％
得られた錫ドープ酸化インジウム膜について実施例１−１と同様に評価を行った。
【００４０】
（実施例１−３）
実施例１−１において、混合ガスとして以下に組成の混合ガスを用いた以外は実施例１−１と同様にして錫ドープ酸化インジウム膜を作成した。
―混合ガス組成―
不活性ガス：ヘリウム ９８．６５体積％
反応性ガス１：水 ０．１体積％（気体として）
反応性ガス２：インジウムアセチルアセトナト １．２体積％
反応性ガス３：ジブチル錫ジアセテート ０．０５体積％
得られた錫ドープ酸化インジウム膜について実施例１−１と同様に評価を行った。
（比較例１−１）
実施例１−１において、混合ガスとして以下に組成の混合ガスを用いた以外は実施例１−１と同様にして錫ドープ酸化インジウム膜を作成した。
―混合ガス組成―
不活性ガス：ヘリウム ９８．７５体積％
反応性ガス１：なし
反応性ガス２：インジウムアセチルアセトナト １．２体積％
反応性ガス３：ジブチル錫ジアセテート ０．０５体積％
得られた錫ドープ酸化インジウム膜について実施例１−１と同様に評価を行った。
【００４１】
（実施例１−４）
実施例１−１において、混合ガスとして以下に組成の混合ガスを用いた以外は実施例１−１と同様にして錫ドープ酸化インジウム膜を作成した。
―混合ガス組成―
不活性ガス：ヘリウム ９８．７４体積％
反応性ガス１：水素 ０．１５体積％
反応性ガス２：インジウムアセチルアセトナト １．２体積％
反応性ガス３：ジブチル錫ジアセテート ０．０５体積％
得られた錫ドープ酸化インジウム膜について実施例１−１と同様に評価を行った。
（実施例１−５）
実施例１−１において、混合ガスとして以下に組成の混合ガスを用いた以外は実施例１−１と同様にして錫ドープ酸化インジウム膜を作成した。
―混合ガス組成―
不活性ガス：ヘリウム ９８．７体積％
反応性ガス１：水素 ０．０５体積％
反応性ガス２：インジウムアセチルアセトナト １．２体積％
反応性ガス３：ジブチル錫ジアセテート ０．０５体積％
得られた錫ドープ酸化インジウム膜について実施例１−１と同様に評価を行った。
【００４２】
（比較例１−２）
実施例１−１において、混合ガスとして以下に組成の混合ガスを用いた以外は実施例１−１と同様にして錫ドープ酸化インジウム膜を作成した。
―混合ガス組成―
不活性ガス：アルゴン ９８．６５体積％
反応性ガス１：酸素 ０．１５体積％
反応性ガス２：インジウムアセチルアセトナト １．２体積％
反応性ガス３：ジブチル錫ジアセテート ０．０５体積％
得られた錫ドープ酸化インジウム膜について実施例１−１と同様に評価を行った。
（比較例１−３）
実施例１−１において、混合ガスとして以下に組成の混合ガスを用いた以外は実施例１−１と同様にして錫ドープ酸化インジウム膜を作成した。
―混合ガス組成―
不活性ガス：アルゴン ９８．２５体積％
反応性ガス１：水素 ０．５体積％
反応性ガス２：インジウムアセチルアセトナト １．２体積％
反応性ガス３：ジブチル錫ジアセテート ０．０５体積％
得られた錫ドープ酸化インジウム膜について実施例１−１と同様に評価を行った。
【００４３】
（実施例１−６）
実施例１−１で用いたアルカリバリアコートを設けたガラス基板を、直流方式マグネトロンスパッタ装置の基材保持台に固定し、真空槽内を１×１０^-5ｔｏｒｒ以下まで減圧した。その後、アルゴンガスと水素ガスとの混合ガス（Ａｒ：Ｈ₂＝１０００：３）を真空槽内に導入し、真空度を１×１０^-3Ｐａとした後、酸化インジウム：酸化錫が９５：５の組成よりなるスパッタリングターゲットを用い、スパッタ出力１００Ｗ、基板温度１００℃にて製膜を行い、錫ドープ酸化インジウム膜を作成した。
得られた錫ドープ酸化インジウム膜について実施例１−１と同様に評価を行った。
（比較例１−４）
実施例１−１で用いたアルカリバリアコートを設けたガラス基板を、直流方式マグネトロンスパッタ装置の基材保持台に固定し、真空槽内を１×１０^-5ｔｏｒｒ以下まで減圧した。その後、アルゴンガスと酸素ガスと水との混合ガス（Ａｒ：Ｏ₂：Ｈ₂Ｏ＝１０００：１：２）を真空槽内に導入し、真空度を１×１０^-3Ｐａとした後、酸化インジウム：酸化錫が９５：５の組成よりなるスパッタリングターゲットを用い、スパッタ出力１００Ｗ、基板温度１００℃にて製膜を行い、錫ドープ酸化インジウム膜を作成した。
得られた錫ドープ酸化インジウム膜について実施例１−１と同様に評価を行った。
【００４４】
（実施例２−１）
実施例１−１において、プラズマを、周波数１０ｋＨｚ、５Ｗ／ｃｍ²の電力を供給して発生させた以外は実施例１−１と同様にして錫ドープ酸化インジウム膜を作成した。
得られた錫ドープ酸化インジウム膜について実施例１−１と同様に評価を行った。
（実施例２−２）
実施例１−１において、プラズマを、周波数２００ｋＨｚ、５Ｗ／ｃｍ²の電力を供給して発生させた以外は実施例１−１と同様にして錫ドープ酸化インジウム膜を作成した。
得られた錫ドープ酸化インジウム膜について実施例１−１と同様に評価を行った。
（実施例２−３）
実施例１−１において、プラズマを、周波数８００ｋＨｚ、５Ｗ／ｃｍ²の電力を供給して発生させた以外は実施例１−１と同様にして錫ドープ酸化インジウム膜を作成した。
得られた錫ドープ酸化インジウム膜について実施例１−１と同様に評価を行った。
（実施例２−４）
実施例１−１において、プラズマを、特開２０００１−７４９０６号公報に記載の実施例１と同様に、波高値１０ｋＶ、放電電流密度１００ｍＡ／ｃｍ² 、周波数６ｋＨｚのパルス電界を印加し、且つ、５Ｗ／ｃｍ²の電力を供給して発生させた以外は実施例１−１と同様にして錫ドープ酸化インジウム膜を作成した。得られた錫ドープ酸化インジウム膜について実施例１−１と同様に評価を行った。
【００４５】
（実施例２−５）
実施例１−１において、プラズマを、供給する電力を０．１Ｗ／ｃｍ²として発生させた以外は実施例１−１と同様にして錫ドープ酸化インジウム膜を作成した。
得られた錫ドープ酸化インジウム膜について実施例１−１と同様に評価を行った。
（実施例２−６）
実施例１−１において、プラズマを、供給する電力を１Ｗ／ｃｍ²として発生させた以外は実施例１−１と同様にして錫ドープ酸化インジウム膜を作成した。得られた錫ドープ酸化インジウム膜について実施例１−１と同様に評価を行った。
（実施例２−７）
実施例１−１において、プラズマを、供給する電力を１。５Ｗ／ｃｍ²として発生させた以外は実施例１−１と同様にして錫ドープ酸化インジウム膜を作成した。
得られた錫ドープ酸化インジウム膜について実施例１−１と同様に評価を行った。
（実施例２−８）
実施例１−１において、プラズマを、供給する電力を１０Ｗ／ｃｍ²として発生させた以外は実施例１−１と同様にして錫ドープ酸化インジウム膜を作成した。
得られた錫ドープ酸化インジウム膜について実施例１−１と同様に評価を行った。
（実施例３−１）
比較例１−３において、錫ドープ酸化インジウム膜を作成した後、空気中１５０℃に保った熱風乾燥機により加熱処理を行ったこと以外は比較例１−３と同様にして錫ドープ酸化インジウム膜を作成した。
得られた錫ドープ酸化インジウム膜について実施例１−１と同様に評価を行った。
得られた結果を併せて表１に示す。
【００４６】
【表１】

【００４７】
（実施例４−１）
実施例１−１において用いたプラズマ放電装置を、図９に示すプラズマ放電処理装置に代え、また、ガラス基板を非晶質シクロポリオレフィン樹脂フィルム（ＪＳＲ社製ＡＲＴＯＮフィルム：厚さ１００μｍ）に代えた以外は実施例１−１と同様にして錫ドープ酸化インジウム膜を作成した。
得られた錫ドープ酸化インジウム膜について実施例１−１と同様に評価を行った。
（実施例４−２）
実施例４−１において、基板を日本ゼオン社製ゼオノアＺＦ１６（厚さ１００μｍ）としたこと以外は実施例４−１と同様にして錫ドープ酸化インジウム膜を作成した。
得られた錫ドープ酸化インジウム膜について実施例１−１と同様に評価を行った。
（実施例４−３）
実施例４−１において、基板を流延法で形成したポリカーボネートフィルム（帝人社製ピュアエース：厚さ１００μｍ）としたこと以外は実施例４−１と同様にして錫ドープ酸化インジウム膜を作成した。
得られた錫ドープ酸化インジウム膜について実施例１−１と同様に評価を行った。
（実施例４−４）
実施例４−１において、基板を流延法で形成したトリアセチルセルロースとしたこと以外は実施例４−１と同様にして錫ドープ酸化インジウム膜を作成した
得られた錫ドープ酸化インジウム膜について実施例１−１と同様に評価を行った。
【００４８】
（比較例４−１）
比較例１−１において、基板を非晶質シクロポリオレフィン樹脂フィルム（ＪＳＲ社製ＡＲＴＯＮフィルム：厚さ１００μｍ）としたこと以外は比較例１−１と同様にして錫ドープ酸化インジウム膜を作成した。
得られた錫ドープ酸化インジウム膜について実施例１−１と同様に評価を行った。
（比較例４−２）
比較例１−１において、基板を日本ゼオン社製ゼオノアＺＦ１６（厚さ１００μｍ）としたこと以外は比較例１−１と同様にして錫ドープ酸化インジウム膜を作成した
得られた錫ドープ酸化インジウム膜について実施例１−１と同様に評価を行った。
（比較例４−３）
比較例１−１において、基板をポリカーボネートフィルム（帝人社製ピュアエース：厚さ１００μｍ）としたこと以外は比較例１−１と同様にして錫ドープ酸化インジウム膜を作成した
得られた錫ドープ酸化インジウム膜について実施例１−１と同様に評価を行った。
（比較例４−４）
比較例１−１において、基板を実施例４−４で用いたトリアセチルセルロースとしたこと以外は比較例１−１と同様にして錫ドープ酸化インジウム膜を作成した
得られた錫ドープ酸化インジウム膜について実施例１−１と同様に評価を行った。
得られた結果を併せて表２に示す。
【００４９】
【表２】

【００５０】
【発明の効果】
本発明の透明導電膜は、透過率特性が良好であり、優れた導伝率を有し、パターニング性に優れ、タッチパネル用フィルム基板、液晶素子プラスチック基板、有機エレクトロルミネッセンス素子プラスチック基板、プラズマディスプレイパネル用電磁遮蔽フィルム、電子ペーパー用フィルム基板の透明導電膜として十分に使用することができる。また、本発明の透明導電膜の形成方法は、工程適性を持ち、本発明の透明導電膜を、安全で、高い生産性で得ることができる。
【図面の簡単な説明】
【図１】本発明の透明導電膜の形成方法に用いられるプラズマ放電処理装置に設置されるプラズマ放電処理容器の一例を示す概略図である。
【図２】本発明の透明導電膜の形成方法に用いられるプラズマ放電処理装置に設置されるプラズマ放電処理容器の他の一例を示す概略図である。
【図３】プラズマ放電処理容器に用いられる円筒型のロール電極の一例を示す概略図である。
【図４】プラズマ放電処理容器に用いられる円筒型のロール電極の一例を示す概略図である。
【図５】プラズマ放電処理容器に用いられる固定型の円筒型電極の一例を示す概略図である。
【図６】プラズマ放電処理容器に用いられる固定型の円筒型電極の一例を示す概略図である。
【図７】プラズマ放電処理容器に用いられる固定型の角柱型電極の一例を示す概略図である。
【図８】プラズマ放電処理容器に用いられる固定型の角柱型電極の一例を示す概略図である。
【図９】本発明の透明導電膜の形成方法に用いられるプラズマ放電処理装置の説明図である。
【符号の説明】
２５、２５ｃ、２５Ｃ；ロール電極
２６、２６ｃ、２６Ｃ、３６、３６ｃ、３６Ｃ；電極
２５ａ、２５Ａ、２６ａ、２６Ａ、３６ａ、３６Ａ；金属等の導電性母材
２５ｂ、２６ｂ、３６ｂ；セラミック被覆処理誘電体
２５Ｂ、２６Ｂ、３６Ｂ；ライニング処理誘電体
３１；プラズマ放電処理容器
４１；電源
５１；ガス発生装置
５２；給気口
５３；排気口
６０；電極冷却ユニット
６１；元巻き基材
６５、６６；ニップローラ
６４、６７；ガイドローラ[0001]
[Industrial application fields]
The present invention is suitably used for various electronic elements such as liquid crystal display elements, organic electroluminescence elements (hereinafter referred to as organic EL elements), plasma display panels (hereinafter referred to as PDPs), electronic paper, touch panels and solar cells. The present invention relates to a transparent conductive film, a method for forming a transparent conductive film, and an article having a transparent conductive film formed by the formation method.
[0002]
[Prior art]
Conventionally, transparent conductive films have been widely used for liquid crystal display elements, organic EL elements, solar cells, touch panels, electromagnetic wave shielding materials, infrared reflective films, and the like.
As the transparent conductive film, metal thin films such as Pt, Au, Ag, and Cu, SnO ₂ , In ₂ O _Three , CdO, ZnO ₂ , SnO ₂ : Sb, SnO ₂ : F, ZnO: Al, In ₂ O _Three : Composite oxide film made of oxide such as Sn and dopant, chalcogenide, LaB ₆ Non-oxide films such as TiN and TiC are used. Among them, an indium oxide film doped with tin (ITO film) is most widely used because it has excellent electrical characteristics and is easily processed by etching.
These transparent conductive films can be formed by vacuum deposition, sputtering, ion plating, vacuum plasma CVD, spray pyrolysis, thermal CVD, sol-gel, or the like.
2. Description of the Related Art In recent years, flat panel displays such as liquid crystal display elements and organic EL elements have been increased in area and definition, and a higher performance transparent conductive film has been demanded. In particular, in a liquid crystal display element, a transparent conductive film having a high electron mobility is required in order to obtain an element or device having a high electric field response.
When used as an electrode of a display element, drawing a circuit, that is, patterning is an indispensable process, and it is an important requirement that patterning can be easily performed. In many cases, the patterning is performed by a photolithography method, and the portion of the transparent conductive film that does not require conduction is dissolved and removed by etching. Therefore, the speed of dissolution of the transparent conductive film by the etching solution is important. It becomes.
[0003]
The conductivity of the transparent conductive film is closely related to its crystallinity, and an oxide with high crystallinity has high conductivity, but the etching rate is slow. Technology for increasing the etching rate while maintaining high conductivity has been studied for a long time, and in particular, the role of hydrogen in the formation of a transparent conductive film has been studied. For example, JP-A-9-293893, JP-A-7-331413, JP-A-8-269686, JP-A-5-239635, JP-A-8-22956, JP-A-9-50712, JP-A-6-330283, JP-A-5 -275727, JP-A-2-54755, and JP-A-2-112112 have an effect of hindering crystallization of the transparent conductive film during film formation, and hydrogen is used when forming the transparent conductive film. Thus, it has been shown that crystallization is hindered, and a transparent conductive film having an amorphous property superior in workability compared to a crystalline transparent conductive film can be obtained.
In addition, hydrogen atoms compensate for dangling bonds (unbonded hands) of other atoms that make up the transparent conductive film, so that electrons trapped in the dangling bonds are reduced and the conductivity of the transparent conductive film is improved. Can do.
An amorphous transparent conductive film, particularly tin-doped indium oxide (ITO), which is widely used, exhibits conductivity even in an amorphous state and has a certain etching rate, but is still not sufficient. By using the technique disclosed in the above publication, a transparent conductive film having a certain degree of conductivity and etching rate can be formed, but it is not sufficient.
[0004]
Among the methods for forming the transparent conductive film, the vacuum evaporation method and the sputtering method can obtain a low-resistance transparent conductive film, and industrially, the specific resistance value is 10 using a DC magnetron sputtering apparatus. ^-Four An ITO film having excellent conductivity on the order of Ω · cm can be obtained.
However, these physical fabrication methods (PVD methods) are intended to grow a film by depositing a target substance on a substrate in a vacuum, so that a vacuum vessel must be used, and thus the apparatus is large and expensive. Moreover, the use efficiency of the raw materials is poor, the productivity is low, and it is difficult to obtain a large-area film. Furthermore, in order to obtain a low resistance product, it is necessary to heat to 200 to 300 ° C. during film formation, and it is difficult to form a low resistance transparent conductive film on a plastic film.
The sol-gel method (coating method) not only requires many processes such as dispersion preparation, coating, and drying, but also requires the use of a binder resin because of its low adhesion to the substrate to be treated. Therefore, the transparency is deteriorated. Moreover, the electrical characteristics of the obtained transparent conductive film are also inferior compared with the case where the PVD method is used.
The thermal CVD method forms a film by spraying a vaporized raw material or raw material solution onto a substrate and thermally decomposing it. The apparatus is simple, the productivity is high, and a large area can be easily formed. Although there is an advantage that it can be performed, it usually has a problem that a substrate to be used is limited because high temperature treatment at 400 ° C. to 500 ° C. is required at the time of firing. In particular, film formation on a plastic film substrate was difficult.
[0005]
The above sol-gel method (coating method) is difficult to obtain a high-performance thin film, and as a method of overcoming the disadvantage that productivity is poor in a method using a vacuum apparatus, discharging is performed at atmospheric pressure or near atmospheric pressure. A method of forming a thin film on a substrate (hereinafter referred to as an atmospheric pressure plasma CVD method) by plasma-exciting a reactive gas has been proposed. Japanese Patent Application Laid-Open No. 2000-303175 discloses a transparent conductive film by an atmospheric pressure plasma CVD method. A technique for forming a film is disclosed. However, under the conditions described in the publication, the transparent conductive film obtained has a specific resistance value of 10 ^-2 Ω · cm or more, specific resistance 1 × 10 ^-3 It was insufficient for forming a transparent conductive film for flat panel displays such as liquid crystal elements, organic EL elements, PDPs, and electronic papers that require electrical characteristics of Ω · cm or less.
Furthermore, in the CVD method, triethylindium is used as a raw material, and this compound has a safety problem such as being ignited and explosive in normal temperature and in the atmosphere. Japanese Patent Application Laid-Open No. 2001-74906 discloses a PDP that has a hard coat layer / transparent conductive layer / antireflection layer with high adhesion, has an infrared ray and electromagnetic wave prevention function, and has excellent scratch resistance and surface hardness. Alternatively, an antireflection film for FED and a method for producing the same are described, and an example of a transparent conductive layer is disclosed. However, the transparent conductive layer described in the publication is not a low-resistance transparent conductive film, but a low-resistance transparent film. It does not satisfy the demand for obtaining a conductive film.
As described above, the transparent conductive film having a somewhat low resistance value is generally crystalline, and there has been a problem that the etching rate previously extended is slow. In order to solve this problem, JP-A-9-50712 and JP-A-2000-129427 have studied the sputtering gas composition when obtaining tin-doped indium oxide by the sputtering method. Since it is a vacuum process, it is difficult to say that the productivity is low and the resistance value is sufficiently low.
Therefore, development of a method for obtaining a transparent conductive film having desired electrical characteristics and process suitability with high productivity is demanded. .
As a result of various studies, the present inventors have adjusted the amount of metal element ions and the amount of hydrogen ions derived from the metal of the main metal oxide constituting the transparent conductive film when the inside of the transparent conductive film is measured by dynamic SIMS. The present inventors have found that a transparent conductive film having a high etching rate can be obtained without sacrificing electrical characteristics. Furthermore, it has been found that the transparent conductive film has a high transmittance by being formed by the atmospheric pressure plasma CVD method, and a transparent conductive film having excellent electrical characteristics can be obtained with high productivity.
[0006]
[Problems to be solved by the invention]
Accordingly, an object of the present invention is to provide a film substrate for a touch panel, a liquid crystal element plastic substrate, an organic electroluminescence element plastic substrate, a plasma display panel having good transmittance characteristics, excellent electrical characteristics, and excellent patternability. It is in providing the transparent conductive film which can fully be used as a conductive film of the electromagnetic shielding film for electronic films, the film substrate for electronic paper, the formation method of this transparent conductive film, and the article | item which has this transparent conductive film. A further object of the present invention is to provide a method for forming a transparent conductive film having process suitability, safety, and high productivity.
[0007]
[Means for Solving the Problems]
The above object of the present invention is to
(1) A transparent conductive film substantially made of a metal oxide and having a specific resistance of 1 × 10 ^-1 The peak intensity ratio (hydrogen / metal) between hydrogen ions and metal element ions derived from the metal of the main metal oxide when measured by dynamic SIMS is 2 to 20 at Ω · cm or less. Transparent conductive film.
(2) The transparent conductive film is made of indium oxide, tin oxide, zinc oxide, F-doped tin oxide, Al-doped zinc oxide, Sb-doped tin oxide, ITO, In ₂ O _Three The transparent conductive film according to (1) above, which is a transparent conductive film containing as a main component one of ZnO-based amorphous materials.
(3) The above (1), wherein the peak intensity ratio (hydrogen / metal) between hydrogen ions and metal element ions derived from the metal of the main metal oxide when measured by dynamic SIMS is 3 to 15 Or the transparent conductive film as described in (2).
(4) Under atmospheric pressure or a pressure near atmospheric pressure, a mixed gas composed of an inert gas and a reactive gas is introduced into the discharge space between the electrodes to form a plasma state, and the base material is changed to the reactive gas in the plasma state. A method for forming a transparent conductive film, comprising exposing and forming the transparent conductive film according to any one of (1) to (3) above.
(5) The method for forming a transparent conductive film as described in (4) above, wherein at least one of the reactive gases is an organometallic compound.
(6) The method for forming a transparent conductive film according to (4) or (5) above, wherein the organometallic compound is an organometallic compound represented by the following general formula 1 or general formula 2.
[0008]
[Chemical formula 2]

[In General Formulas 1 and 2, M represents In, Sn, Zn, R ₁ , R ₂ Each represents an optionally substituted alkyl group, aryl group or alkoxyl group, R represents a hydrogen atom or a substituent, and R represents R ₁ , R ₂ To form a ring. R _Three Each represents an alkyl group or an aryl group which may have a substituent. n ₁ Represents an integer and n ₂ Represents an integer. ]
(7) The method for forming a transparent conductive film according to any one of (4) to (6), wherein the reactive gas contains an oxidizing gas.
(8) The method for forming a transparent conductive film according to any one of (4) to (6) above, wherein the reactive gas contains water, a reducing gas, or an oxidizing gas.
(9) The method for forming a transparent conductive film according to any one of (4) to (8), wherein the inert gas is argon or helium.
[0009]
(10) The electric field applied between the electrodes is a high frequency electric field having a frequency of 100 kHz or more, and 1 W / cm ² The method for forming a transparent conductive film according to any one of (4) to (9), wherein the electric power is supplied and discharged.
(11) The method for forming a transparent conductive film according to (10), wherein the electric field applied between the electrodes is a high-frequency electric field having a frequency of 150 MHz or less.
(12) The method for forming a transparent conductive film according to (10) or (11), wherein the electric field applied between the electrodes is a high-frequency electric field having a frequency of 200 kHz or more.
(13) The method for forming a transparent conductive film according to any one of (10) to (12), wherein the electric field applied between the electrodes is a high-frequency electric field having a frequency of 800 kHz or more.
(14) The power supplied between the electrodes is 1.2 W / cm ² It is above, The formation method of the transparent conductive film of any one of said (10)-(13) characterized by the above-mentioned.
(15) The power supplied between the electrodes is 50 W / cm ² The method for forming a transparent conductive film according to any one of (10) to (14) above, wherein:
(16) The power supplied between the electrodes is 20 W / cm ² The method for forming a transparent conductive film according to any one of (10) to (15) above, which is as follows.
(17) The method for forming a transparent conductive film according to any one of (10) to (16), wherein the high-frequency electric field applied between the electrodes is a continuous sine wave electric field.
(18) The method for forming a transparent conductive film according to any one of (4) to (17), wherein at least one of the electrodes is covered with a dielectric.
(19) The method for forming a transparent conductive film according to (18), wherein the dielectric is an inorganic substance having a relative dielectric constant of 6 to 45.
(20) The method for forming a transparent conductive film according to the above (18) or (19), wherein the surface roughness Rmax of the electrode is 10 μm or less.
[0010]
(21) The method for forming a transparent conductive film according to any one of (4) to (20) above, wherein the conductive film is formed on the substrate at a surface temperature of the substrate of 300 ° C. or lower.
(22) The method for forming a transparent conductive film according to any one of (4) to (21), wherein a heat treatment is performed after the transparent conductive film is formed on the substrate.
(23) The method for forming a transparent conductive film according to (22) above, wherein the heat treatment is performed in an air atmosphere.
(24) The method for forming a transparent conductive film according to (22) above, wherein the heat treatment is performed in a reducing atmosphere.
(25) The method for forming a transparent conductive film according to the above (22), wherein the heat treatment is performed in an oxidizing atmosphere.
(26) The method for forming a transparent conductive film according to (22), wherein the heat treatment is performed in a vacuum atmosphere.
(27) The method for forming a transparent conductive film according to the above (22), wherein the heat treatment is performed in an inert gas atmosphere.
(28) The method for forming a transparent conductive film according to any one of (22) to (27) above, wherein the temperature of the heat treatment is 50 to 300 ° C.
(29) Any of the above (4) to (28), wherein the transparent conductive film to be formed is an ITO film having an In / Sn atomic ratio in the range of 100 / 0.1 to 100/15 The method for forming a transparent conductive film according to claim 1.
(30) The transparent conductive film to be formed is a transparent conductive film having a carbon content in the range of 0 to 5.0 atomic concentration, any one of (4) to (29) above The formation method of the transparent conductive film as described in any one of Claims 1-3.
[0011]
(31) An article having a transparent conductive film formed by the method for forming a transparent conductive film according to any one of (4) to (30) above on a substrate.
(32) The article according to (31) above, wherein the substrate is a transparent resin film.
(33) The above (32), wherein the transparent resin film is a film substrate for a touch panel, a liquid crystal element plastic substrate, an organic electroluminescence element plastic substrate, an electromagnetic shielding film for a plasma display panel, or a film substrate for electronic paper. The article described.
(34) The article according to any one of (31) to (33) above, wherein the transparent conductive film is a patterned electrode.
Achieved by:
[0012]
Hereinafter, the present invention will be described in detail.
First, it is the transparent conductive film which consists essentially of the metal oxide of this invention, and specific resistance is 1 * 10. ^-1 The peak intensity ratio (hydrogen / metal) between the hydrogen ion and the metal element ion derived from the metal of the main metal oxide when measured by dynamic SIMS (hereinafter referred to as the hydrogen ion and the metal of the present invention) The transparent conductive film (hereinafter referred to as the transparent conductive film of the present invention) having a peak intensity ratio of element ions of 2 to 20 will be described in detail.
In the present invention, the peak intensity ratio between the hydrogen ion and the metal element ion of the present invention is more preferably in the range of 3 to 15, particularly preferably in the range of 4 to 8.
[0013]
In the present invention, the dynamic SIMS measurement is performed with reference to the surface analysis practical series secondary ion mass spectrometry (published by Maruzen 2000 edited by the Surface Science Society of Japan). The peak intensity ratio (hydrogen / metal) of the metal element ions derived from the metal ions of the main metal oxide can be determined by the following method.
In the present invention, the main metal oxide refers to a metal oxide mainly constituting the transparent conductive film, and does not include, for example, a metal oxide serving as a dopant. For example, in the case of an ITO film obtained by doping tin with indium oxide, the main metal oxide refers to an oxide of indium, and does not include a doped tin oxide.
Apparatus: ADEPT1010 manufactured by Physical Electronics
Primary ion: Cs
Primary ion acceleration voltage: 5 kV
Primary ion current: 100 nA
Primary ion irradiation area: 400 μm
Primary ion incident angle: 60 °
Capture range: 49%
Negative ion detection
The sample is measured after storage for 8 hours in the measurement chamber.
After etching about 1/3 of the film thickness under the above conditions, the signal of hydrogen and the main metal oxide at the sputtering time from which 1/3 of the film thickness is sputtered is integrated, and from this integrated value, hydrogen ions and The peak intensity ratio (hydrogen / metal) of metal element ions derived from the metal of the main metal oxide is determined.
[0014]
In order to form the transparent conductive film of the present invention, a method of introducing hydrogen at the time of film formation, a method of removing hydrogen by a method such as a heat treatment after film formation, and the like are mentioned, but it is not particularly limited.
A transparent conductive film refers to a thin film that is optically transparent and conductive.
The transparent conductive film has been researched and developed for a long time, and typical transparent conductive films include metal thin films such as Pt film, Au film, Ag film, Cu film, SnO, etc. ₂ Film, ZnO ₂ Membrane, In ₂ O _Three Oxide films such as films, and complex oxide films using these oxides and dopants (for example, ITO films, IZO films, FTO films, ATO films), chalcogenide films, LaB ₆ Examples thereof include non-oxide films such as a film, a TiN film, and a TiC film. Particularly preferred are an ITO film and an IZO film.
The method for forming the transparent conductive film of the present invention is not particularly limited, and an atmospheric pressure plasma CVD method, a general magnetron sputtering method, a sol-gel method, or the like can be used. It is preferable to form a transparent conductive film.
When the atmospheric pressure plasma CVD method is used, it is easy to control the conditions for forming the transparent conductive film, the transmittance is high, and the transparent conductive film having excellent electrical characteristics and high etching rate can be obtained safely with high productivity.
[0015]
Next, under the atmospheric pressure of the present invention or a pressure near atmospheric pressure, a mixed gas composed of an inert gas and a reactive gas is introduced into a discharge space between the electrodes to form a plasma state, and the substrate is reacted in the plasma state. A method for forming a transparent conductive film (hereinafter referred to as a method for forming a transparent conductive film of the present invention) for forming the transparent conductive film of the present invention by exposure to a reactive gas will be described in detail.
The method for forming a transparent conductive film of the present invention is to form the transparent conductive film of the present invention using a so-called atmospheric pressure plasma CVD method.
Hereinafter, the atmospheric pressure plasma CVD method used in the method for forming a transparent conductive film of the present invention will be described.
The atmospheric pressure plasma CVD method is, for example, a high-frequency electric field of 100 kHz or more between opposed electrodes and 100 W / cm. ² The following electric power (power density) is supplied to excite the reactive gas to generate plasma.
In the present invention, the frequency of the high-frequency electric field applied between the electrodes is preferably 100 kHz or more, more preferably 200 kHz or more. More preferably, it is 800 kHz or more. Moreover, 150 MHz or less is preferable.
The power supplied between the electrodes is 0.5 W / cm. ² The above is preferable, more preferably 1 W / cm ² That's it. More preferably 1.2 W / cm ² It is. Also, 100W / cm ² The following is preferable, more preferably 50 W / cm ² It is as follows. More preferably 20 W / cm ² It is as follows. Here, the electric power is a unit area (cm ² ) Represents the power per unit.
Further, the high-frequency electric field applied between the electrodes may be an intermittent pulse wave or a continuous sine wave, but in order to obtain the effect of the present invention, it is a continuous sine wave. It is preferable.
[0016]
In the present invention, the electric field is applied between the electrodes as described above to bring the reactive gas into a plasma state in the discharge space. However, it is preferable to maintain a uniform glow discharge state in the discharge space. It is preferable to use a plasma discharge treatment apparatus that employs an electrode that can be maintained.
As an electrode for maintaining a uniform glow discharge state, an electrode in which a dielectric is coated on a metal base material is preferable. These electrodes in which a dielectric material is coated on a metal base material are used for at least one of the opposed application electrode and the ground electrode, but are more preferably used for both the opposed application electrode and the ground electrode.
The dielectric used here is preferably an inorganic substance having a relative dielectric constant of 6 to 45. Examples of such a dielectric include ceramics such as alumina and silicon nitride, silicate glass, and borate. Examples thereof include glass lining materials such as glass.
Further, the substrate is placed between the electrodes or conveyed between the electrodes and exposed to the reactive gas in the plasma state. When transporting between electrodes and exposing to a reactive gas in a plasma state, the substrate is transported in contact with the roll electrode. In this case, the roll electrode specification is such that the roll electrode can be transported in contact with the substrate. In addition, by further polishing the dielectric surface and setting the electrode surface roughness Rmax (JIS B 0601) to 10 μm or less, the thickness of the dielectric and the gap between the electrodes can be kept constant, The discharge state can be stabilized. Furthermore, it is possible to greatly improve the durability by eliminating distortion and cracking due to a difference in thermal shrinkage and residual stress and coating a highly accurate inorganic dielectric that is not porous.
[0017]
In the production of these electrodes, the metal matrix is coated with a dielectric at a high temperature. At least the dielectric on the side in contact with the substrate on which the transparent conductive film is formed is polished, and the metal matrix of the electrode is further polished. It is necessary to reduce the difference in thermal expansion between the material and the dielectric. For this purpose, it is preferable to line the surface of the metal base material with an inorganic material with a controlled amount of bubbles as a layer that can absorb stress. . In particular, the material is preferably glass obtained by a melting method such as glazing, and further the amount of bubbles mixed in the lowermost layer in contact with the conductive metal base material is set to 20 to 30 vol%, and the subsequent layers are set to 5 vol% or less. Thus, a good electrode which is dense and does not generate cracks can be obtained.
Further, as another method for coating the metal base material of the electrode with a dielectric, a ceramic is sprayed densely with a porosity of 10 vol% or less, and further, a sealing treatment is performed with an inorganic material that is cured by a sol-gel reaction. Is mentioned. Here, in order to accelerate the sol-gel reaction, it is preferable to use thermal curing or UV curing. Furthermore, when the sealing liquid is diluted, and coating and curing are repeated several times in succession, the mineralization is further improved and the deterioration is reduced. There is no dense electrode.
[0018]
As a plasma discharge treatment apparatus used in the method for forming a transparent conductive film of the present invention, a conventionally used plasma discharge treatment apparatus can be used, but a plasma discharge treatment having an electrode as described above preferably used in the present invention. The apparatus will be described with reference to the drawings.
FIGS. 1-8 is for demonstrating the plasma discharge processing container and electrode used therefor in a plasma discharge processing apparatus, and in this plasma discharge processing container, it arrange | positions in the position facing the roll electrode used as a ground electrode. It is discharged between the fixed electrode to be the applied electrode, a reactive gas is introduced between the electrodes to form a plasma state, and the long film-like substrate wound around the roll electrode is reacted in this plasma state. A thin film is formed by exposure to a sex gas.
In the present invention, the plasma discharge treatment vessel used for forming the transparent conductive film is not limited to this, and the glow discharge is stably maintained under atmospheric pressure or a pressure near atmospheric pressure to form the transparent conductive film. Any gas can be used as long as the reactive gas can be excited to be in a plasma state.
As another method, there is a so-called jet method in which a thin film is formed by placing or transporting a base material in the vicinity of an electrode that is not between electrodes and spraying separately generated plasma on the base material.
[0019]
FIG. 1 is a schematic view showing an example of a plasma discharge treatment vessel installed in a plasma discharge treatment apparatus used in the method for forming a transparent conductive film of the present invention.
In FIG. 1, a long film-like substrate F is conveyed while being wound around a roll electrode 25 that rotates in the conveying direction (clockwise in the figure). The fixed electrode 26 is composed of a plurality of cylinders, and is installed facing the roll electrode 25. The base material F wound around the roll electrode 25 is pressed by the nip rollers 65 and 66, regulated by the guide roller 64, transported to the discharge processing space secured by the plasma discharge processing container 31, and subjected to discharge plasma processing. Subsequently, it is conveyed to the next process via the guide roller 67. Further, the partition plate 54 is disposed in the vicinity of the nip rollers 65 and 66 to suppress the air accompanying the base material F from entering the plasma discharge processing container 31.
The air brought into the plasma discharge treatment container 31 with the substrate F is preferably suppressed to 1% by volume or less, and 0.1% by volume or less with respect to the total volume of the gas in the plasma discharge treatment container 31. More preferably, it is suppressed. This can be achieved by the nip rollers 65 and 66.
Note that a mixed gas (inert gas, a reducing gas which is a reactive gas, and an organometallic compound) used for the discharge plasma treatment is introduced into the plasma discharge treatment vessel 31 from the air supply port 52, and the treated gas is exhausted. The air is exhausted from the port 53.
[0020]
FIG. 2 is a schematic view showing another example of a plasma discharge treatment container installed in a plasma discharge treatment apparatus used in the method for forming a transparent conductive film of the present invention, which is different from the plasma discharge treatment container shown in FIG. It is.
In FIG. 1, a cylindrical electrode is used as the fixed electrode 26 facing the roll electrode 25 as an electrode, whereas in FIG. 2, the fixed electrode 26 facing the roll electrode 25 is fixed as an electrode. As the electrode, a prismatic electrode 36 is used.
The prismatic electrode 36 shown in FIG. 2 has a wider discharge range than the cylindrical electrode 26 shown in FIG. 1, and is therefore preferably used in the conductive film forming method of the present invention.
FIG. 3 is a schematic diagram showing an example of the cylindrical roll electrode shown in FIGS. 1 and 2, and FIG. 4 shows another example of the cylindrical roll electrode shown in FIGS. Schematic diagram, FIG. 5 is a schematic diagram showing an example of the electrode fixed in the cylindrical shape shown in FIG. 1, and FIG. 6 is another example of the electrode fixed in the cylindrical shape shown in FIG. FIG. 7 is a schematic view showing an example of an electrode fixed in the prismatic shape shown in FIG. 2, and FIG. 8 is another example of the electrode fixed in the prismatic shape shown in FIG. It is the schematic which shows an example.
[0021]
In FIG. 3, a roll electrode that serves as a ground electrode 25c Is composed of a combination of ceramics sprayed on a conductive base material 25a such as metal and then coated with a ceramic coated dielectric 25b sealed with an inorganic material. The ceramic coated dielectric 25b is coated with 1 mm of a single piece, and the roll diameter is 200 mmφ after coating. Roll electrode 25c Is grounded. In addition, as shown in FIG. 4, a roll electrode is formed by combining a conductive base material 25A such as a metal with a lining treatment dielectric 25B provided with an inorganic material by lining. 25C May be configured. As the lining material, silicate glass, borate glass, phosphate glass, germanate glass, tellurite glass, aluminate glass, vanadate glass and the like are preferably used. Of these, borate glass is more preferred because it is easy to process. Examples of the material of the conductive base materials 25a and 25A such as metal include metals such as silver, platinum, stainless steel, aluminum, and iron. Stainless steel is preferable from the viewpoint of processing. As the ceramic material used for thermal spraying, alumina, silicon nitride, or the like is preferably used. Among these, alumina is more preferable because it is easily processed.
In the form of actual use, a roll base material having a stainless steel jacket having a cooling means with cooling water is used as the base material of the roll electrode (not shown).
[0022]
5 and 6 illustrate the fixed electrode 26 that is the application electrode shown in FIG. 1, and FIGS. 7 and 8 illustrate the fixed prismatic electrode 36 shown in FIG. Fixed electrode in 26c And the electrode in FIG. 36c 3 is a combination in which ceramics are thermally sprayed on conductive base materials 26a and 36a, such as metal, as in the case of roll electrode 25c in FIG. The fixed electrode shown in FIG. 26C And the electrode in FIG. 36C Roll electrode in FIG. 25c In the same manner as described above, a combination of electrodes coated with lining dielectrics 26B and 36B provided with an inorganic material by lining the conductive base materials 26A and 36A such as metal 26C , 36C Is configured.
In the actual use form, a hollow stainless steel pipe (not shown) is used as the base material of the electrode, and the diameter after coating with the ceramic-coated dielectric is 12 mm or 15 mm. The Further, 14 fixed electrodes are provided along the periphery of the roll electrode.
The power source to be applied to the electrode is not particularly limited, but a pearl industry high frequency power supply (200 kHz), a pearl industry high frequency power supply (800 kHz), a JEOL high frequency power supply (13.56 MHz), a pearl industry high frequency power supply (150 MHz). Etc. can be used.
[0023]
FIG. 9 is a conceptual diagram showing an example of a plasma discharge treatment apparatus used in the method for forming a transparent conductive film of the present invention.
In FIG. 9, the plasma discharge processing container 31 has the same configuration as the plasma discharge processing container shown in FIG.
Moreover, the reactive gas generator 51, the power supply 41, the electrode cooling unit 60, the pump P, etc. are arrange | positioned as an apparatus structure. As a coolant for the electrode cooling unit 60, an insulating material such as distilled water or oil is used.
The electrodes 25 and 36 shown in FIG. 9 are the same as the electrodes shown in FIGS. 3 to 8, and the gap between the opposing electrodes is set to about 1 mm, for example.
The distance between the electrodes is determined in consideration of the thickness of the solid dielectric placed on the base material of the electrodes, the magnitude of the applied voltage, the purpose of using plasma, and the like.
The shortest distance between the solid dielectric and the electrode when a solid dielectric is placed on one of the electrodes, and the distance between the solid dielectrics when a solid dielectric is placed on both electrodes is a uniform discharge in either case. From the viewpoint of being able to go, 0.5 mm to 20 mm is preferable, and 1 mm ± 0.5 mm is particularly preferable.
A roll electrode 25 and a fixed electrode 36 are arranged in a predetermined position in the plasma discharge treatment vessel 31, and the flow rate of the mixed gas generated by the reactive gas generator 51 is controlled, so that the plasma discharge treatment is performed from the air supply port 52. It introduce | transduces in the container 31, and the inside of the plasma discharge processing container 31 is filled with the mixed gas used for plasma processing. The used reactive gas is exhausted from the exhaust port 53.
Next, the roll electrode 25 is grounded, and a voltage is applied to the electrode 36 by the power source 41 to generate discharge plasma. Here, the substrate F is supplied from a roll-shaped original winding substrate 61. The supplied base material F is guided by the guide roller 64, and is transported between the electrodes in the plasma discharge processing container 31 in contact with the roll electrode 25, and the surface is subjected to a discharge process by the discharge plasma during the transport. It is guided to the guide roller 67 and conveyed to the next process. Here, as for the base material F, a conductive film is formed only on the surface opposite to the side in contact with the roll electrode 25.
The voltage applied to the electrode 36 fixed from the power source 41 is appropriately determined. For example, the voltage is adjusted to about 0.5 to 10 kV, and the power source frequency is adjusted to 0.5 kHz to 150 MHz. As for the method of applying power, either a continuous sine wave continuous oscillation mode called continuous mode or an intermittent oscillation mode that turns ON / OFF intermittently called pulse mode may be adopted. A denser and better quality film can be obtained.
[0024]
A Pyrex (R) glass container or the like is preferably used as the plasma discharge processing container 31, but a metal container may be used as long as it is insulated from the electrodes. For example, the inner surface of an aluminum or stainless steel frame is used. A container in which polyimide resin or the like is attached to a metal frame, or a container in which a metal frame is subjected to ceramic spraying to provide insulation is used.
Further, the temperature of the substrate surface during the discharge plasma treatment is not particularly limited. When glass is used as the substrate, it is preferably 300 ° C. or lower, and when polymer is used, it is preferably 200 ° C. or lower. In order to adjust to said temperature range, an electrode and a base material can be cooled with a cooling means as needed.
In the present invention, the above-described discharge plasma treatment is performed at or near atmospheric pressure. Here, the vicinity of atmospheric pressure refers to a pressure of 20 kPa to 110 kPa, and 93 kPa is preferable to obtain the effect of the present invention. ~ 104 kPa is preferred.
Further, in the discharge electrode used in the conductive film forming method of the present invention, at least the maximum height (Rmax) of the surface roughness defined by JIS B 0601 on the electrode surface on the side in contact with the substrate is 10 μm or less. Although it is preferable from the viewpoint of obtaining the effect described in the present invention, it is more preferable to adjust the maximum value of the surface roughness to 8 μm or less, and particularly preferably to 7 μm or less.
The centerline average surface roughness (Ra) specified by JIS B 0601 is preferably 0.5 μm or less, more preferably 0.1 μm or less.
[0025]
Next, a mixed gas composed of an inert gas and a reactive gas used in the conductive film forming method of the present invention will be described.
In the mixed gas, the reactive gas varies depending on the type of the transparent conductive film desired to be provided on the substrate, but enters a plasma state in order to form the transparent conductive film as a mixed gas with the inert gas.
As the inert gas in the mixed gas of the present invention, a group 18 element of the periodic table, specifically, helium, neon, argon, krypton, xenon, radon, and a gas that is not involved in a reaction such as nitrogen gas. In order to obtain the effects described in the present invention, argon or helium is particularly preferable.
A plurality of reactive gases in the mixed gas of the present invention can be used, but at least one kind contains a component that is in a plasma state in the discharge space and forms a transparent conductive film. Although there is no restriction | limiting in particular in the reactive gas containing the component which forms a transparent conductive film, An organometallic compound (Hereinafter, it may be mentioned the organometallic compound of this invention.) Is used preferably. These organometallic compounds of the present invention are not particularly limited as long as they form a transparent conductive film and are vaporized, but organometallic compounds having oxygen in the molecule are preferred.
As these organometallic compounds of the present invention, organometallic compounds such as β-diketone metal complexes, metal alkoxides, and alkyl metals can be used. Particularly preferred organometallic compounds of the present invention are represented by the following general formula 1 or general formula: 2 is an organometallic compound represented by 2;
[0026]
[Chemical 3]

[In General Formulas 1 and 2, M represents In, Sn, Zn, R ₁ , R ₂ Each represents an optionally substituted alkyl group, aryl group or alkoxyl group, R represents a hydrogen atom or a substituent, and R represents R ₁ , R ₂ To form a ring. R _Three Each represents an alkyl group or an aryl group which may have a substituent. n ₁ Represents an integer and n ₂ Represents an integer. ]
R ₁ , R ₂ , R _Three As the alkyl group which may have a substituent represented by formula (1), an alkyl group having 1 to 10 carbon atoms is preferable, and R, R ₁ , R ₂ , R _Three As the substituent, is preferably a fluorine atom.
Specific examples of the ligand that forms the organometallic compound represented by the general formula 1 include the compounds shown below.
[0027]
[Formula 4]

[0028]
[Chemical formula 5]

The following diketone compounds are also preferred as the ligand.
[0029]
[Chemical 6]

[0030]
In general formulas 1 and 2, M is preferably indium (In).
Among the organometallic compounds of the present invention, preferred examples include indium hexafluoropentanedionate, indium methyl (trimethyl) acetylacetate, indium acetylacetonate, indium isoporopoxide, indium trifluoropentanedionate, tris (2 , 2,6,6-tetramethyl 3,5-heptanedionate) indium, di-n-butylbis (2,4-pentanedionate) tin, di-n-butyldiacetoxytin, di-t-butyldi Acetoxytin, tetraisopropoxytin, tetrabutoxytin, zinc acetylacetonate and the like can be mentioned.
Of these, indium acetylacetonate, tris (2,2,6,6-tetramethyl 3,5-heptanedionate) indium, zinc acetylacetonate and di-n-butyldiacetoxytin are particularly preferable. These organometallic compounds are generally commercially available. For example, indium acetylacetonate can be easily obtained from Tokyo Chemical Industry Co., Ltd.
[0031]
In this invention, in order to improve the electroconductivity of a conductive film with the reactive gas containing the component which forms a transparent conductive film, a doping agent can be contained as a reactive gas. Examples of these doping agents include aluminum isopropoxide, nickel acetylacetonate, manganese acetylacetonate, boron isopropoxide, n-butoxyantimony, tri-n-butylantimony, di-n-butylbis (2,4- Pentanedionate) tin, di-n-butyldiacetoxytin, di-t-butyldiacetoxytin, tetraisopropoxytin, tetrabutoxytin, tetrabutyltin, zinc acetylacetonate, hexafluoropropylene, octafluorocyclobutane And tetrafluoromethane.
Furthermore, in this invention, the transparent conductive film which has high electroconductivity and a big etching rate can be formed by using water as a reactive gas. The amount of water mixed in the reaction gas is preferably in the range of 0.0001 to 10% by volume of the mixed gas as a gas. More preferably, it is in the range of 0.001 to 1% by volume.
In addition, as a reaction gas, an oxidizing gas such as oxygen, a reducing gas such as hydrogen, and other nitric oxide, nitrogen dioxide, carbon monoxide, carbon dioxide, and the like can be used.
[0032]
The amount ratio of the reactive gas containing the component for forming the transparent conductive film and the reactive gas used for doping differs depending on the type of the transparent conductive film to be formed. For example, in an ITO film obtained by doping tin with indium oxide, the amount of reactive gas so that the In / Sn atomic ratio of the obtained ITO film is in the range of 100 / 0.1 to 100/15. Adjust the ratio. Preferably, it adjusts so that it may become the range of 100 / 0.5-100 / 10. The atomic ratio of In / Sn can be determined by XPS measurement. In the FTO film obtained by doping fluorine into tin oxide, the atomic ratio of Sn / F of the obtained FTO film is 100/0. The amount ratio of the reactive gas is adjusted to be in the range of 01 to 100/50. The atomic ratio of Sn / F can be determined by XPS measurement. Also, In ₂ O _Three In the —ZnO-based amorphous transparent conductive film, the amount ratio of the reactive gas is adjusted so that the obtained In / Zn atomic ratio is in the range of 100/50 to 100/5. The atomic ratio of In / Zn can be determined by XPS measurement.
Furthermore, it is also possible to add a reactive gas in order to adjust the resistance value of the formed transparent conductive film. Examples of the reactive gas used for adjusting the resistance value of the transparent conductive film include titanium triisopropoxide, tetramethoxysilane, tetraethoxysilane, and hexamethyldisiloxane.
In general, the thickness of the transparent conductive film is preferably in the range of 0.1 nm to 1000 nm.
[0033]
In the method for forming a transparent conductive film according to the present invention, the characteristics of the transparent conductive film can be adjusted by exposing to a reactive gas in a plasma state and forming a transparent conductive film on a substrate, followed by heat treatment and heat treatment. Since it is possible, it is preferable to heat-treat. The amount of hydrogen in the transparent conductive film can also be adjusted by this heat treatment.
The temperature of the heat treatment is preferably in the range of 50 to 300 ° C, more preferably in the range of 100 to 200 ° C. The heating atmosphere is not particularly limited, and is appropriately selected from an air atmosphere, a reducing atmosphere containing a reducing gas such as hydrogen, an oxidizing atmosphere containing an oxidizing gas such as oxygen, or a vacuum or an inert gas atmosphere. be able to. In the case of a reducing atmosphere or an oxidizing atmosphere, the reducing gas and the oxidizing gas are preferably diluted with an inert gas such as a rare gas or nitrogen. In this case, the concentration of the reducing gas and the oxidizing gas is preferably 0.01 to 5%, more preferably 0.1 to 3%.
Moreover, when using an organometallic compound as reactive gas for formation of the transparent conductive film of this invention, the transparent conductive film obtained may contain a trace amount of carbon, but the carbon content is 0-5.0. It is preferably within the range of atomic number concentration. In particular, it is preferable that it exists in the range of 0.01-3 atomic number concentration.
As a base material that can be used in the method for forming a transparent conductive film of the present invention, a film-like material, a sheet-like material, a three-dimensional material such as a lens shape, etc., which can form a transparent conductive film on its surface If there is no particular limitation.
If these base materials can be placed between the electrodes, they can be placed between the electrodes, and if the base material cannot be placed between the electrodes, the generated plasma is blown onto the base material. Can be formed.
[0034]
There is no particular limitation on the material constituting the substrate. Glass can also be used, but it can be made into a plasma state with low-pressure glow discharge under atmospheric pressure or near atmospheric pressure, so a conductive film is also formed on resin materials such as resin films. can do.
Examples of these resin films include cellulose ester such as cellulose triacetate, polyester, polycarbonate, polystyrene, and gelatin, polyvinyl alcohol (PVA), acrylic resin, polyester resin, cellulose resin, etc. You can use what you set.
These base materials also include base materials coated with an antiglare layer, a clear hard coat layer, a back coat layer, an antistatic layer, and the like.
Specifically, polyester films such as polyethylene terephthalate and polyethylene naphthalate, polyethylene film, polypropylene film, cellophane, cellulose diacetate film, cellulose acetate butyrate film, cellulose acetate propionate film, cellulose acetate phthalate film, cellulose triacetate film Film made of cellulose esters such as cellulose nitrate film or derivatives thereof, polyvinylidene chloride film, polyvinyl alcohol film, ethylene vinyl alcohol film, syndiotactic polystyrene film, polycarbonate film, norbornene resin film, polymethylpentene Film, polyetherketone Irumu, polyimide film, polyether sulfone film, polysulfone film, polyether ketone imide film, a polyamide film, a fluororesin film, a nylon film, polymethyl methacrylate film, may be mentioned acrylic film or polyarylate film.
[0035]
The above-mentioned film materials can be used alone or in combination as appropriate. Among these, commercially available products such as ZEONEX (manufactured by Nippon Zeon Co., Ltd.) and ARTON (manufactured by Nippon Synthetic Rubber Co., Ltd.) can be preferably used. Furthermore, even for materials with a large intrinsic birefringence, such as polycarbonate, polyarylate, polysulfone, and polyethersulfone, conditions such as solution casting and melt extrusion, as well as stretching conditions in the longitudinal and lateral directions are set as appropriate. Can be used.
As mentioned above, although the base material used for the formation method of the transparent conductive film of this invention was demonstrated, the base material used in this invention is not limited by these description.
Moreover, as said film-form base material, the film thickness of 10 micrometers-1000 micrometers is used preferably.
Moreover, when forming a electrically conductive film by this invention, you may provide an adhesive layer in order to improve adhesiveness between a base material and a transparent conductive film as needed. In order to improve the optical characteristics, an antireflection film can be provided on the surface opposite to the surface provided with the transparent conductive film. Further, an antifouling layer can be provided on the outermost layer of the film. In addition, a layer for imparting gas barrier properties and solvent resistance may be provided as necessary.
The method for forming these layers is not particularly limited, and a coating method, a vacuum deposition method, a sputtering method, an atmospheric pressure plasma CVD method, or the like can be used. Particularly preferred is the atmospheric pressure plasma CVD method.
As a method for forming these layers by atmospheric pressure plasma CVD, for example, a method for forming an antireflection film, a method disclosed in Japanese Patent Application No. 2000-021573 can be used.
In the present invention, when a transparent conductive film is provided, it is preferable that the transparent conductive film has a thickness deviation of ± 10% of the average film thickness, more preferably within ± 5%. Preferably, it is within ± 1%.
[0036]
【Example】
EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.
(Example 1-1)
A glass substrate (50 mm × 50 mm × 1 mm) provided with a silica film having a thickness of about 50 nm as an alkali barrier coat as a base material was prepared.
The plasma discharge apparatus used was a parallel plate type electrode, and the glass substrate was placed between the electrodes.
In addition, as a ground (ground) electrode, a 200 mm × 200 mm × 2 mm stainless steel plate is coated with a high-density, high-adhesion alumina sprayed film, and then a solution obtained by diluting tetramethoxysilane with ethyl acetate is applied and dried. The electrode was cured by ultraviolet irradiation and sealed, and the dielectric surface thus coated was polished, smoothed, and processed to have an Rmax of 5 μm. As the application electrode, an electrode obtained by coating a dielectric with a dielectric on a hollow square pure titanium pipe under the same conditions as the ground electrode was used. A plurality of application electrodes were prepared and provided to face the ground electrode to form a discharge space.
As a power source used for plasma generation, a high frequency power source JRF-10000 manufactured by JEOL Ltd. is used, and the frequency is 13.56 MHz and 5 W / cm. ² Power was supplied.
A mixed gas having the following composition was flowed between the electrodes to form a plasma state, and the glass substrate was subjected to atmospheric pressure plasma treatment to form a tin-doped indium oxide film on the glass substrate.
―Composition of mixed gas―
Inert gas: Helium 98.74% by volume
Reactive gas 1: Water 0.01% by volume (as gas)
Reactive gas 2: Indium acetylacetonate 1.2% by volume
Reactive gas 3: Dibutyltin diacetate 0.05% by volume
[0037]
The prepared tin-doped indium oxide film was evaluated by the following method.
<Transmissivity>
In accordance with JIS-R-1635, measurement was performed using a spectrophotometer U-4000 type manufactured by Hitachi, Ltd. The wavelength of the test light was 550 nm.
<Film thickness, deposition rate>
The film thickness was measured with a FE-3000 reflection spectroscopic film thickness meter manufactured by Photo Co., and the film thickness obtained by gradually grading the film thickness with the plasma treatment time was taken as the film forming speed.
<Resistivity>
According to JIS-R-1637, it calculated | required by the four terminal method. In addition, Mitsubishi Chemical Loresta-GP and MCP-T600 were used for the measurement.
[0038]
<Measurement of carbon content>
The film composition and carbon content were measured by using ESCALAB-200R manufactured by VG Scientific as an XPS surface analyzer. The measurement was performed using Mg for the X-ray anode and an output of 600 W (acceleration voltage: 15 kV, emission current: 40 mA). The energy resolution was set to be 1.5 to 1.7 eV when defined by the half width of a clean Ag3d5 / 2 peak.
Before the measurement, the surface layer corresponding to 10 to 20% of the thickness of the thin film was removed by etching in order to remove the influence of contamination. Ar ion etching was used to remove the surface layer.
First, the range of binding energy from 0 eV to 1100 eV was measured at a data acquisition interval of 1.0 eV to determine what elements were detected.
Next, with respect to all the detected elements except for the etching ion species, the data capture interval was set to 0.2 eV, and the photoelectron peak giving the maximum intensity was subjected to narrow scan, and the spectrum of each element was measured. The obtained spectrum is preferably COMMON DATA PROCESSING SYSTEM (Ver. 2.3 or later) manufactured by VAMAS-SCA-JAPAN in order not to cause a difference in the content calculation result due to a difference in measuring apparatus or computer. ) After the transfer, the process was performed with the same software, and the value of the carbon content was determined as the atomic concentration (at%).
Further, the ratio of tin to indium (In / Sn ratio) was also determined as the ratio of the atomic number concentration obtained from the above results.
Further, before performing the quantitative process, the calibration of the Scale for each element was performed, and a 5-point smoothing process was performed. In the quantitative process, the peak area intensity (cps × eV) from which the background was removed was used. The Shirley method was used for background processing.
For the Shirley method, see D.C. A. Shirley, Phys. Rev. , B5, 4709 (1972).
[0039]
<Peak intensity ratio (hydrogen / metal) (H / M ratio) of metal ion derived from metal of hydrogen ion and main metal oxide>
The H / M ratio was determined by the secondary ion mass spectrometry described above.
<Etching rate>
Water: Concentrated hydrochloric acid: 40% FeCl _Three An etching solution in which an aqueous solution was mixed at 81: 8: 7% by weight was heated to 30 ° C., a sample on which a tin-doped indium oxide film was formed was immersed therein, and removal of the film was visually evaluated. Those that could remove the tin-doped indium oxide film within 1 minute were marked with ◯, those that could be removed by soaking for 1 minute or longer, and those that remained after being soaked for 3 minutes were marked with x.
(Example 1-2)
In Example 1-1, a tin-doped indium oxide film was prepared in the same manner as in Example 1-1 except that a mixed gas having the following composition was used as the mixed gas.
―Composition of mixed gas―
Inert gas: Helium 98.7% by volume
Reactive gas 1: 0.05% by volume of water (as gas)
Reactive gas 2: Indium acetylacetonate 1.2% by volume
Reactive gas 3: Dibutyltin diacetate 0.05% by volume
The obtained tin-doped indium oxide film was evaluated in the same manner as in Example 1-1.
[0040]
(Example 1-3)
In Example 1-1, a tin-doped indium oxide film was prepared in the same manner as in Example 1-1 except that a mixed gas having the following composition was used as the mixed gas.
―Composition of mixed gas―
Inert gas: Helium 98.65% by volume
Reactive gas 1: Water 0.1% by volume (as gas)
Reactive gas 2: Indium acetylacetonate 1.2% by volume
Reactive gas 3: Dibutyltin diacetate 0.05% by volume
The obtained tin-doped indium oxide film was evaluated in the same manner as in Example 1-1.
(Comparative Example 1-1)
In Example 1-1, a tin-doped indium oxide film was prepared in the same manner as in Example 1-1 except that a mixed gas having the following composition was used as the mixed gas.
―Composition of mixed gas―
Inert gas: Helium 98.75% by volume
Reactive gas 1: None
Reactive gas 2: Indium acetylacetonate 1.2% by volume
Reactive gas 3: Dibutyltin diacetate 0.05% by volume
The obtained tin-doped indium oxide film was evaluated in the same manner as in Example 1-1.
[0041]
(Example 1-4)
In Example 1-1, a tin-doped indium oxide film was prepared in the same manner as in Example 1-1 except that a mixed gas having the following composition was used as the mixed gas.
―Composition of mixed gas―
Inert gas: Helium 98.74% by volume
Reactive gas 1: Hydrogen 0.15% by volume
Reactive gas 2: Indium acetylacetonate 1.2% by volume
Reactive gas 3: Dibutyltin diacetate 0.05% by volume
The obtained tin-doped indium oxide film was evaluated in the same manner as in Example 1-1.
(Example 1-5)
In Example 1-1, a tin-doped indium oxide film was prepared in the same manner as in Example 1-1 except that a mixed gas having the following composition was used as the mixed gas.
―Composition of mixed gas―
Inert gas: Helium 98.7% by volume
Reactive gas 1: Hydrogen 0.05% by volume
Reactive gas 2: Indium acetylacetonate 1.2% by volume
Reactive gas 3: Dibutyltin diacetate 0.05% by volume
The obtained tin-doped indium oxide film was evaluated in the same manner as in Example 1-1.
[0042]
(Comparative Example 1-2)
In Example 1-1, a tin-doped indium oxide film was prepared in the same manner as in Example 1-1 except that a mixed gas having the following composition was used as the mixed gas.
―Composition of mixed gas―
Inert gas: argon 98.65% by volume
Reactive gas 1: Oxygen 0.15% by volume
Reactive gas 2: Indium acetylacetonate 1.2% by volume
Reactive gas 3: Dibutyltin diacetate 0.05% by volume
The obtained tin-doped indium oxide film was evaluated in the same manner as in Example 1-1.
(Comparative Example 1-3)
In Example 1-1, a tin-doped indium oxide film was prepared in the same manner as in Example 1-1 except that a mixed gas having the following composition was used as the mixed gas.
―Composition of mixed gas―
Inert gas: argon 98.25% by volume
Reactive gas 1: Hydrogen 0.5% by volume
Reactive gas 2: Indium acetylacetonate 1.2% by volume
Reactive gas 3: Dibutyltin diacetate 0.05% by volume
The obtained tin-doped indium oxide film was evaluated in the same manner as in Example 1-1.
[0043]
(Example 1-6)
The glass substrate provided with the alkali barrier coat used in Example 1-1 was fixed to the base material holder of the direct current magnetron sputtering apparatus, and the inside of the vacuum chamber was 1 × 10. ^-Five The pressure was reduced to less than torr. Thereafter, a mixed gas of argon gas and hydrogen gas (Ar: H ₂ = 1000: 3) is introduced into the vacuum chamber, and the degree of vacuum is 1 × 10 ^-3 After setting to Pa, using a sputtering target having a composition of indium oxide: tin oxide of 95: 5, film formation was performed at a sputtering output of 100 W and a substrate temperature of 100 ° C., thereby producing a tin-doped indium oxide film.
The obtained tin-doped indium oxide film was evaluated in the same manner as in Example 1-1.
(Comparative Example 1-4)
The glass substrate provided with the alkali barrier coat used in Example 1-1 was fixed to the base material holder of the direct current magnetron sputtering apparatus, and the inside of the vacuum chamber was 1 × 10. ^-Five The pressure was reduced to less than torr. Thereafter, a mixed gas of argon gas, oxygen gas and water (Ar: O ₂ : H ₂ O = 1000: 1: 2) is introduced into the vacuum chamber, and the degree of vacuum is 1 × 10. ^-3 After setting to Pa, using a sputtering target having a composition of indium oxide: tin oxide of 95: 5, film formation was performed at a sputtering output of 100 W and a substrate temperature of 100 ° C., thereby producing a tin-doped indium oxide film.
The obtained tin-doped indium oxide film was evaluated in the same manner as in Example 1-1.
[0044]
(Example 2-1)
In Example 1-1, the plasma was used at a frequency of 10 kHz and 5 W / cm. ² A tin-doped indium oxide film was prepared in the same manner as in Example 1-1 except that the electric power was generated.
The obtained tin-doped indium oxide film was evaluated in the same manner as in Example 1-1.
(Example 2-2)
In Example 1-1, the plasma was used at a frequency of 200 kHz and 5 W / cm. ² A tin-doped indium oxide film was prepared in the same manner as in Example 1-1 except that the electric power was generated.
The obtained tin-doped indium oxide film was evaluated in the same manner as in Example 1-1.
(Example 2-3)
In Example 1-1, the plasma was subjected to a frequency of 800 kHz, 5 W / cm. ² A tin-doped indium oxide film was prepared in the same manner as in Example 1-1 except that the electric power was generated.
The obtained tin-doped indium oxide film was evaluated in the same manner as in Example 1-1.
(Example 2-4)
In Example 1-1, the plasma was subjected to a peak value of 10 kV and a discharge current density of 100 mA / cm as in Example 1 described in Japanese Patent Laid-Open No. 20001-74906. ² Apply a pulse electric field with a frequency of 6 kHz, and 5 W / cm ² A tin-doped indium oxide film was prepared in the same manner as in Example 1-1 except that the above power was generated. The obtained tin-doped indium oxide film was evaluated in the same manner as in Example 1-1.
[0045]
(Example 2-5)
In Example 1-1, the power for supplying plasma is 0.1 W / cm. ² A tin-doped indium oxide film was prepared in the same manner as in Example 1-1 except that the above was generated.
The obtained tin-doped indium oxide film was evaluated in the same manner as in Example 1-1.
(Example 2-6)
In Example 1-1, the power to supply plasma is 1 W / cm. ² A tin-doped indium oxide film was prepared in the same manner as in Example 1-1 except that the above was generated. The obtained tin-doped indium oxide film was evaluated in the same manner as in Example 1-1.
(Example 2-7)
In Example 1-1, the power to supply plasma is 1.5 W / cm. ² A tin-doped indium oxide film was prepared in the same manner as in Example 1-1 except that the above was generated.
The obtained tin-doped indium oxide film was evaluated in the same manner as in Example 1-1.
(Example 2-8)
In Example 1-1, the power supplied to plasma is 10 W / cm. ² A tin-doped indium oxide film was prepared in the same manner as in Example 1-1 except that the above was generated.
The obtained tin-doped indium oxide film was evaluated in the same manner as in Example 1-1.
(Example 3-1)
In Comparative Example 1-3, a tin-doped indium oxide film was prepared in the same manner as in Comparative Example 1-3, except that a tin-doped indium oxide film was prepared and then heat-treated with a hot air dryer maintained at 150 ° C. in air. It was created.
The obtained tin-doped indium oxide film was evaluated in the same manner as in Example 1-1.
The obtained results are shown together in Table 1.
[0046]
[Table 1]

[0047]
(Example 4-1)
The plasma discharge device used in Example 1-1 was replaced with the plasma discharge treatment device shown in FIG. 9, and the glass substrate was replaced with an amorphous cyclopolyolefin resin film (ARTON film manufactured by JSR: thickness 100 μm). A tin-doped indium oxide film was prepared in the same manner as in Example 1-1 except for the above.
The obtained tin-doped indium oxide film was evaluated in the same manner as in Example 1-1.
(Example 4-2)
In Example 4-1, a tin-doped indium oxide film was prepared in the same manner as in Example 4-1, except that the substrate was Zeonor ZF16 (thickness: 100 μm) manufactured by Nippon Zeon.
The obtained tin-doped indium oxide film was evaluated in the same manner as in Example 1-1.
(Example 4-3)
In Example 4-1, a tin-doped indium oxide film was prepared in the same manner as in Example 4-1, except that the substrate was a polycarbonate film formed by casting (Pure Ace manufactured by Teijin Limited: thickness 100 μm). .
The obtained tin-doped indium oxide film was evaluated in the same manner as in Example 1-1.
(Example 4-4)
In Example 4-1, a tin-doped indium oxide film was prepared in the same manner as in Example 4-1, except that the substrate was triacetyl cellulose formed by the casting method.
The obtained tin-doped indium oxide film was evaluated in the same manner as in Example 1-1.
[0048]
(Comparative Example 4-1)
In Comparative Example 1-1, a tin-doped indium oxide film was prepared in the same manner as in Comparative Example 1-1 except that the substrate was an amorphous cyclopolyolefin resin film (ARTON film manufactured by JSR Corporation: thickness 100 μm).
The obtained tin-doped indium oxide film was evaluated in the same manner as in Example 1-1.
(Comparative Example 4-2)
In Comparative Example 1-1, a tin-doped indium oxide film was prepared in the same manner as in Comparative Example 1-1 except that the substrate was ZEONOR ZF16 (thickness: 100 μm) manufactured by ZEON Corporation.
The obtained tin-doped indium oxide film was evaluated in the same manner as in Example 1-1.
(Comparative Example 4-3)
In Comparative Example 1-1, a tin-doped indium oxide film was prepared in the same manner as in Comparative Example 1-1 except that the substrate was a polycarbonate film (Pure Ace manufactured by Teijin Limited: thickness 100 μm).
The obtained tin-doped indium oxide film was evaluated in the same manner as in Example 1-1.
(Comparative Example 4-4)
In Comparative Example 1-1, a tin-doped indium oxide film was prepared in the same manner as in Comparative Example 1-1 except that the substrate was the triacetyl cellulose used in Example 4-4.
The obtained tin-doped indium oxide film was evaluated in the same manner as in Example 1-1.
The obtained results are shown together in Table 2.
[0049]
[Table 2]

[0050]
【The invention's effect】
The transparent conductive film of the present invention has good transmittance characteristics, excellent conductivity, excellent patternability, touch panel film substrate, liquid crystal element plastic substrate, organic electroluminescence element plastic substrate, plasma display panel It can be used satisfactorily as a transparent conductive film for an electromagnetic shielding film and a film substrate for electronic paper. Moreover, the formation method of the transparent conductive film of this invention has process aptitude, and can obtain the transparent conductive film of this invention with safety | security and high productivity.
[Brief description of the drawings]
FIG. 1 is a schematic view showing an example of a plasma discharge treatment vessel installed in a plasma discharge treatment apparatus used in the method for forming a transparent conductive film of the present invention.
FIG. 2 is a schematic view showing another example of a plasma discharge treatment vessel installed in a plasma discharge treatment apparatus used in the method for forming a transparent conductive film of the present invention.
FIG. 3 is a schematic view showing an example of a cylindrical roll electrode used in a plasma discharge treatment container.
FIG. 4 is a schematic view showing an example of a cylindrical roll electrode used in a plasma discharge treatment container.
FIG. 5 is a schematic view showing an example of a fixed cylindrical electrode used in a plasma discharge treatment container.
FIG. 6 is a schematic view showing an example of a fixed cylindrical electrode used in a plasma discharge treatment container.
FIG. 7 is a schematic view showing an example of a fixed prismatic electrode used in a plasma discharge treatment container.
FIG. 8 is a schematic view showing an example of a fixed prismatic electrode used in a plasma discharge treatment container.
FIG. 9 is an explanatory view of a plasma discharge treatment apparatus used in the method for forming a transparent conductive film of the present invention.
[Explanation of symbols]
25, 25c , 25C ; Roll electrode
26, 26c , 26C , 36, 36c , 36C ;electrode
25a, 25A, 26a, 26A, 36a, 36A; conductive base material such as metal
25b, 26b, 36b; ceramic-coated dielectric
25B, 26B, 36B; lining treatment dielectric
31; Plasma discharge treatment vessel
41; power supply
51; gas generator
52; Air inlet
53; exhaust port
60; Electrode cooling unit
61; Original winding base material
65, 66; nip roller
64, 67; guide rollers

Claims (34)

It is a transparent conductive film substantially made of a metal oxide, has a specific resistance of 1 × 10 ⁻¹ Ω · cm or less, and is derived from the metal of hydrogen ions and the main metal oxide when measured by dynamic SIMS A transparent conductive film, wherein the peak intensity ratio of metal element ions (hydrogen / metal) is 2 to 20. The transparent conductive film is mainly composed of indium oxide, tin oxide, zinc oxide, F-doped tin oxide, Al-doped zinc oxide, Sb-doped tin oxide, ITO, or In ₂ O ₃ —ZnO-based amorphous. The transparent conductive film according to claim 1, wherein the transparent conductive film is a conductive film. 3. The peak intensity ratio (hydrogen / metal) between hydrogen ions and metal element ions derived from the metal of the main metal oxide when measured by dynamic SIMS is 3 to 15. 3. Transparent conductive film. A gas mixture of an inert gas and a reactive gas is introduced into the discharge space between the electrodes under a pressure at or near atmospheric pressure to form a plasma state, and the substrate is exposed to the reactive gas in the plasma state. Item 4. A method for forming a transparent conductive film, comprising forming the transparent conductive film according to any one of Items 1 to 3. The method for forming a transparent conductive film according to claim 4, wherein at least one of the reactive gases is an organometallic compound. 6. The method for forming a transparent conductive film according to claim 4, wherein the organometallic compound is an organometallic compound represented by the following general formula 1 or general formula 2.

[In General Formulas 1 and 2, M represents In, Sn, Zn, R ₁ and R ₂ each represents an alkyl group, an aryl group, or an alkoxyl group that may have a substituent, and R represents a hydrogen atom, Represents a substituent, and R may combine with R ₁ and R ₂ to form a ring. R ₃ represents an alkyl group or an aryl group each optionally having a substituent. n ₁ represents an integer, and n ₂ represents an integer. ] Reactive gas contains oxidizing gas, The formation method of the transparent conductive film of any one of Claims 4-6 characterized by the above-mentioned. The method for forming a transparent conductive film according to claim 4, wherein the reactive gas contains water, a reducing gas, or an oxidizing gas. The method for forming a transparent conductive film according to claim 4, wherein the inert gas is argon or helium. The transparent electric field according to any one of claims 4 to 9, wherein the electric field applied between the electrodes is a high-frequency electric field having a frequency of 100 kHz or more, and electric power of 1 W / cm ² or more is supplied for discharging. A method for forming a conductive film. The method for forming a transparent conductive film according to claim 10, wherein the electric field applied between the electrodes is a high-frequency electric field having a frequency of 150 MHz or less. The method for forming a transparent conductive film according to claim 10 or 11, wherein the electric field applied between the electrodes is a high-frequency electric field having a frequency of 200 kHz or more. The method for forming a transparent conductive film according to claim 10, wherein the electric field applied between the electrodes is a high-frequency electric field having a frequency of 800 kHz or more. The method for forming a transparent conductive film according to claim 10, wherein the power supplied between the electrodes is 1.2 W / cm ² or more. The method for forming a transparent conductive film according to claim 10, wherein the power supplied between the electrodes is 50 W / cm ² or less. The method for forming a transparent conductive film according to claim 10, wherein the power supplied between the electrodes is 20 W / cm ² or less. The method for forming a transparent conductive film according to claim 10, wherein the high-frequency electric field applied between the electrodes is a continuous sine wave electric field. The method for forming a transparent conductive film according to claim 4, wherein at least one of the electrodes is covered with a dielectric. The method for forming a transparent conductive film according to claim 18, wherein the dielectric is an inorganic substance having a relative dielectric constant of 6 to 45. 20. The method for forming a transparent conductive film according to claim 18, wherein the surface roughness Rmax of the electrode is 10 [mu] m or less. The method for forming a transparent conductive film according to any one of claims 4 to 20, wherein the conductive film is formed on the substrate at a surface temperature of the substrate of 300 ° C or lower. The method for forming a transparent conductive film according to any one of claims 4 to 21, wherein heat treatment is performed after the transparent conductive film is formed on the substrate. The method for forming a transparent conductive film according to claim 22, wherein the heat treatment is performed in an air atmosphere. The method for forming a transparent conductive film according to claim 22, wherein the heat treatment is performed in a reducing atmosphere. The method for forming a transparent conductive film according to claim 22, wherein the heat treatment is performed in an oxidizing atmosphere. The method for forming a transparent conductive film according to claim 22, wherein the heat treatment is performed in a vacuum atmosphere. The method for forming a transparent conductive film according to claim 22, wherein the heat treatment is performed in an inert gas atmosphere. The method for forming a transparent conductive film according to any one of claims 22 to 27, wherein the temperature of the heat treatment is 50 to 300 ° C. The transparent conductive film to be formed is an ITO film having an In / Sn atomic ratio in the range of 100 / 0.1 to 100/15, according to any one of claims 4 to 28. A method for forming a transparent conductive film. 30. The transparent conductive film according to any one of claims 4 to 29, wherein the formed transparent conductive film is a transparent conductive film having a carbon content in the range of 0 to 5.0 atomic concentration. Forming method. An article having a transparent conductive film formed by the method for forming a transparent conductive film according to any one of claims 4 to 30 on a substrate. 32. The article according to claim 31, wherein the substrate is a transparent resin film. The article according to claim 32, wherein the transparent resin film is a film substrate for a touch panel, a liquid crystal element plastic substrate, an organic electroluminescence element plastic substrate, an electromagnetic shielding film for a plasma display panel, or an electronic paper film substrate. The article according to any one of claims 31 to 33, wherein the transparent conductive film is a patterned electrode.

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