JP2005068455A

JP2005068455A - Deposited film forming method and apparatus

Info

Publication number: JP2005068455A
Application number: JP2003209314A
Authority: JP
Inventors: Tomohito Ozawa; 智仁小澤; Shigenori Ueda; 重教植田; Makoto Aoki; 誠青木
Original assignee: Canon Inc
Current assignee: Canon Inc
Priority date: 2003-08-28
Filing date: 2003-08-28
Publication date: 2005-03-17

Abstract

【課題】堆積膜特性の均一性を極めて高いレベルとし、さらに、画像欠陥の原因となる球状突起を低減することで高画質を満たす堆積膜を形成可能とする。
【解決手段】減圧可能な反応容器１０１内に複数の円筒状基体１０２が設置される。反応容器１０１内に供給された原料ガスを第１の高周波電力導入手段１０３および第２の高周波電力導入手段１０４から導入された高周波電力で分解することで、円筒状基体１０２に堆積膜が形成される。第１の高周波電力導入手段１０３は円筒状基体１０２の配置円外に配置され、第２の高周波電力導入手段１０４は円筒状基体１０２の配置円内に配置される。第１の高周波電力導入手段１０３に印加する高周波電力と第２の高周波電力導入手段１０４に印加する高周波電力とは独立に制御され、それぞれ周波数の異なる複数の高周波電力が導入される。
【選択図】図１An object of the present invention is to make it possible to form a deposited film satisfying a high image quality by setting the uniformity of deposited film characteristics to an extremely high level and reducing spherical projections that cause image defects.
A plurality of cylindrical substrates are installed in a reaction vessel that can be depressurized. By decomposing the raw material gas supplied into the reaction vessel 101 with the high frequency power introduced from the first high frequency power introduction means 103 and the second high frequency power introduction means 104, a deposited film is formed on the cylindrical substrate 102. The The first high-frequency power introducing means 103 is arranged outside the arrangement circle of the cylindrical base 102, and the second high-frequency power introduction means 104 is arranged within the arrangement circle of the cylindrical base 102. The high frequency power applied to the first high frequency power introducing means 103 and the high frequency power applied to the second high frequency power introducing means 104 are controlled independently, and a plurality of high frequency powers having different frequencies are introduced.
[Selection] Figure 1

Description

【０００１】
【産業上の利用分野】
本発明は、被処理基体上に堆積膜、とりわけ機能性膜、特に高周波電力により生成されるプラズマを用いた半導体デバイス、電子写真感光体等の堆積膜を利用した光受容部材を形成するのに適した堆積膜形成方法及び装置に関する。
【０００２】
【従来技術】
従来、半導体デバイス、電子写真感光体、画像入力用ラインセンサー、撮影デバイス、光起電力デバイス等を形成するための真空処理方法には、プラズマＣＶＤ法、イオンプレーティング法、プラズマエッチング法等、高周波電力により生成されるプラズマを用いた堆積膜形成方法が知られており、そのための装置も数多く実用化されている。
【０００３】
例えば、プラズマＣＶＤ法を用いた堆積膜形成方法、つまり、高周波電力のグロー放電により原料ガスを分解し、その分解種を被処理基体上に堆積させることによって堆積膜を形成する方法が好適な堆積膜形成手段として実用化されている。この方法を用いた例として、原料ガスにシランガスを用いてアモルファスシリコン（以下「ａ−Ｓｉ」と記す）薄膜の形成が知られており、そのための装置も各種提案されている。
【０００４】
このようなプラズマＣＶＤ法を用いたａ−Ｓｉ薄膜の堆積膜形成装置として、ＶＨＦ帯の周波数を用いたＶＨＦプラズマＣＶＤ法（以下「ＶＨＦ−ＰＣＶＤ」と記す）による従来の堆積膜形成装置、具体的には電子写真用感光体形成装置の一例を示す模式的な構成図を図７に示す。図７（ａ）は、従来の電子写真用感光体形成装置の縦断面を示す模式図であり、図７（ｂ）は、図７（ａ）に示す電子写真用感光体形成装置横断面図を示す模式図である。反応容器７０１の側面には排気管が一体に形成されており、排気管の他端には不図示の排気手段が接続されている。円筒状基体７０２は反応容器７０１の中心部を取り囲むように配置されており、回転軸７１３によって保持され、ヒータ７１１により加熱されるように構成されている。モータ７１４より回転軸７１３が回転し、円筒状基体７０２が自転するようになっている。
【０００５】
原料ガスは、不図示の原料ガス供給手段から原料ガス導入管７１２を経て反応容器７０１内へ導入される。ＶＨＦ帯の高周波電力は、高周波電源７０９から高周波マッチングボックス７０６を経てカソード電極７０４から反応容器７０１内へ導入される。この際、円筒状基体７０２が回転軸７１３を介してアース電位に維持されているため、アノード電極として作用する。
【０００６】
このような従来の電子写真用感光体形成装置を用いた堆積膜の形成は、以下のような手順で行なわれる。まず、反応容器７０１内に円筒状基体７０２を設置し、不図示の排気装置により反応容器内を排気する。続いて、ヒータ７１１により円筒状基体７０２を所定の温度になるよう制御する。その後、原料ガス供給手段から原料ガス導入管７１２を介して反応容器７０１内に原料ガスを導入し、カソード電極７０４から反応容器７０１内にＶＨＦ帯の高周波電力を導入する。これにより、円筒状基体７０２上に堆積膜が形成される。所望の膜厚の形成が行われた後、高周波電力及び原料ガスの供給を止めて堆積膜の形成を終える。同様の操作を複数回操り返すことによって、所望の多層構造の光受容層を形成することができる。堆積膜形成中に、円筒状基体７０１を回転させることにより円筒状基体７０１の表面の全周に亘って均一な堆積膜が形成される。
【０００７】
このような電子写真感光体形成装置により高品質な堆積膜の形成が行われているが、更なる品質向上のために電子写真感光体形成方法及び装置の改良が進められている。
【０００８】
反応容器内に複数の円筒状基体を同一円周上に等間隔で配置し、カソード電極を円筒状基体の配置円内外に配置して円筒状基体上に堆積膜を形成する堆積膜形成方法及び装置の技術に関して開示されている（例えば、特許文献１参照）。この堆積膜形成方法及び装置を用いて円筒状基体上に堆積膜を形成することにより、堆積膜特性の均一性向上の効果が得られることが示されている。
【０００９】
【特許文献１】
特開平１１−０９２９３２号公報（第１４頁〜第１８頁、図１、図８、図１０）
【００１０】
【発明が解決しようとする課題】
上述した従来の堆積膜形成方法及び装置により、堆積膜特性の均一性が改善されることで良好な堆積膜の形成が可能となり、また、歩留の改善による生産性の向上も可能となってきている。しかし、製品の高品質化が進む一方で、製品に対する市場の要求が日々高まってきており、更なる高品質な製品を製造可能な堆積膜形成方法及び装置が求められているのが現状である。
【００１１】
例えば、電子写真感光体においては、電子写真装置の高速化、小型化、低価格化等の要求が非常に高まっている。そのため、これらを実現可能にする電子写真用感光体の特性を実現するとともに、電子写真用感光体製造時の良品率の向上が不可欠となっている。更に、近年デジタル電子写真装置及びカラー電子写真装置の普及が目覚しく、これら電子写真装置では、文字原稿のみにとどまらず、写真、デザイン等の画像を出力する機会も増加しているため、電子写真装置の高画質化への要求も高まっている。これらを実現するためには、従来以上に感光体特性、具体的には帯電能、感度の均一性の向上及び画像欠陥を引き起こす感光体表面の微小な突起の低減が不可欠となっている。
【００１２】
このような感光体特性の向上及び感光体表面の微小な突起の低減を目指して、堆積膜形成時の条件、堆積膜の層構成の最適化もなされているが、堆積膜形成方法及び堆積膜形成装置の面からの改善も強く望まれている。
【００１３】
このような状況下において、前述した従来の堆積膜形成装置、堆積膜形成方法においても、堆積膜特性の向上に関して、まだ改善の余地が残されているのが現状である。
【００１４】
例えば、ＶＨＦ−ＣＶＤ法による堆積膜形成方法及び装置では、ＶＨＦ帯、あるいはその近傍の周波数の高周波電力を用いてプラズマを生成して基板上に堆積膜を形成することにより、堆積膜の堆積速度の向上、堆積膜の特性の向上が達成可能となった。しかしながら、このような周波数帯の高周波電力を用いた場合、反応容器内での高周波電力の波長が反応容器、高周波電極、基板及び基板ホルダー等と同程度の長さとなり、反応容器中で高周波電力が定在波を形成しやすくなる。そのため、上述した従来の堆積膜形成方法及び装置では、この定在波によって反応容器内で鉛直方向及び断面方向で電力の強弱が生じプラズマ特性が異なってしまうため、基板上に形成される堆積膜特性の均一化が難しかった。更に、電力の弱い場所に反応容器内のダスト等が吸着され、これが突起の原因となることから突起の集中を抑えることが難しかった。
【００１５】
また、特許文献１に記載の堆積膜形成方法及び装置では、円筒状基体の配置円内外から高周波電力を導入し、更にそれぞれの高周波電力を独立に制御することにより、定在波により生じる反応容器内での鉛直方向及び断面方向の電力の強弱を低減することで、従来の堆積膜形成方法及び装置よりも安定した堆積膜の形成を可能とした。しかしながら、前記堆積膜形成方法及び装置においても、現在市場が要求している高画質を実現するための堆積膜特性の均一性及び画像欠陥数の条件を満たすことが難しくなりつつある。
【００１６】
【目的】
そこで、本発明の目的は、従来の堆積膜形成装置よりも堆積膜特性の均一性を極めて高いレベルとし、更に画像欠陥の原因となる球状突起を低減することで、市場要求の非常に高い高画質を満たす堆積膜を形成可能な堆積膜形成方法及び装置を提供することにある。
【００１７】
【課題を解決するための手段】
本発明者らは上記目的を達成すべく鋭意検討を行った結果、堆積膜形成方法及び堆積膜形成装置において、高周波電力導入方法が堆積膜特性の均一性及び画像欠陥低減に大きな影響を及ぼすことを見出した。具体的には、円筒状基体を同一円周上に等間隔で配置し、周波数が異なる複数の高周波電力を該円筒状基体の配置円内外から独立に制御して導入することで、複数の基体上に球状突起が形成しにくく且つ良好な特性を有する堆積膜を均一に形成可能であることを見出し、本発明を完成させるに至った。
【００１８】
具体的には、
（１）減圧可能な反応容器内に複数の円筒状基体を配置し、反応容器中に供給された原料ガスを第１の高周波電力導入手段と第２の高周波電力導入手段から導入された高周波電力により分解し、該円筒状基体上に堆積膜を形成する堆積膜形成方法において、該第１の高周波電力導入手段により該円筒状基体の配置円外から高周波電力を導入し、該第２の高周波電力導入手段により該円筒状基体の配置円内から高周波電力を導入し、該第１の高周波電力導入手段に印加する高周波電力と該第２の高周波電力導入手段に印加する高周波電力を独立に制御し、該第１の高周波電力導入手段と該第２の高周波電力導入手段に周波数が異なる複数の高周波電力を導入して堆積膜を形成することを特徴とする堆積膜形成方法に関する。
【００１９】
（２）（１）に記載の堆積膜形成方法において、前記第１の高周波電力導入手段に印加する複数の高周波電力の上位２つの電力値をとる高周波電力のうち周波数が高い方の電力値をＰ１、周波数の低い方の電力値をＰ２、Ｒ１を以下の（ａ）とし、前記第２の高周波電力導入手段に印加する複数の高周波電力の上位２つの電力値をとる高周波電力のうち周波数が高い方の電力値をＰ１’、周波数の低い方の電力値をＰ２’、Ｒ２を以下の（ｂ）とし、以下の条件（ｃ）を満たす高周波電力を導入して堆積膜を形成することを特徴とする堆積膜形成方法に関する。
【００２０】
（ａ）Ｒ１＝Ｐ２／（Ｐ１＋Ｐ２）
（ｂ）Ｒ２＝Ｐ２’／（Ｐ１’＋Ｐ２’）
（ｃ）Ｒ１≠Ｒ２
（３）（１）から（２）に記載の堆積膜形成方法において、前記第１の高周波電力導入手段に印加する複数の高周波電力のうち上位２つの電力値をとる高周波電力の周波数をｆ１及びｆ２としたとき、以下の条件（ｄ）、（ｅ）を満たし、
前記第２の高周波電力導入手段に印加する複数の高周波電力のうち上位２つの電力値をとる高周波電力の周波数をｆ１’及びｆ２’としたとき、以下の条件（ｆ）、（ｇ）を満たす高周波電力を導入して堆積膜を形成することを特徴とする堆積膜形成方法に関する。
【００２１】
（ｄ）１０ＭＨｚ≦ｆ２＜ｆ１≦２５０ＭＨｚ
（ｅ）０．１≦Ｒ１≦０．９
（ｆ）１０ＭＨｚ≦ｆ２’＜ｆ１’≦２５０ＭＨｚ
（ｇ）０．１≦Ｒ２≦０．９
（４）（１）から（３）に記載の堆積膜形成方法において、前記円筒状基体の配置円の中心と同じくする同心円上に等間隔で複数設置した前記第１の高周波電力導入手段から高周波電力を導入して前記円筒状基体上に堆積膜を形成することを特徴とする堆積膜形成方法に関する。
【００２２】
（５）（１）から（４）に記載の堆積膜形成方法において、前記円筒状基体の配置円の中心に設置した前記第２の高周波電力導入手段から高周波電力を導入して前記円筒状基体上に堆積膜を形成することを特徴とする堆積膜形成方法に関する。
【００２３】
（６）（１）から（５）に記載の堆積膜形成方法において、複数の円筒状基体を取り囲み、且つ中心軸が円筒状基体の配置円の中心を通るように設置した円筒状壁で構成される反応容器内で前記円筒状基体上に堆積膜を形成することを特徴とする堆積膜形成方法に関する。
【００２４】
（７）（６）に記載の堆積膜形成方法において、前記第１の高周波電力導入手段に印加する高周波電力を前記反応容器外から導入して前記円筒状基体上に堆積膜を形成することを特徴とする堆積膜形成方法に関する。
【００２５】
（８）（６）に記載の堆積膜形成方法において、前記第１の高周波電力導入手段に印加する高周波電力を前記反応容器内から導入して前記円筒状基体上に堆積膜を形成することを特徴とする堆積膜形成方法に関する。
【００２６】
（９）（３）から（８）に記載の堆積膜形成方法において、前記第１の高周波電力導入手段に印加する高周波電力の周波数ｆ１と前記第２の高周波電力導入手段に印加する高周波電力の周波数ｆ１’とが以下の条件（ｈ）を満たす高周波電力を用いて前記円筒状基体上に堆積膜を形成することを特徴とする堆積膜形成方法に関する。
【００２７】
（ｈ）ｆ１＝ｆ１’
（１０）（３）から（９）に記載の堆積膜形成方法において、前記第１の高周波電力導入手段に印加する高周波電力の周波数ｆ２と前記第２の高周波電力導入手段に印加する高周波電力の周波数ｆ２’とが以下の条件（ｉ）を満たす高周波電力を用いて前記円筒状基体上に堆積膜を形成することを特徴とする堆積膜形成方法に関する。
【００２８】
（ｉ）ｆ２＝ｆ２’
（１１）（１）から（１０）に記載の堆積膜形成方法において、前記円筒状基体上に形成する堆積膜がシリコン原子を含有する非晶質材料であることを特徴とする堆積膜形成方法に関する。
【００２９】
（１２）（１）から（１１）に記載の堆積膜形成方法において、電子写真感光体の製造に用いられることを特徴とする堆積膜形成方法に関する。
【００３０】
（１３）減圧可能な反応容器内に複数の円筒状基体を設置し、反応容器中に供給された原料ガスを第１の高周波電力導入手段及び第２の高周波電力導入手段から導入された高周波電力により分解し、該円筒状基体上に堆積膜を形成する堆積膜形成装置において、該円筒状基体は同一円周上に等間隔で配置され、該第１の高周波電力導入手段は該円筒状基体の配置円外に配置され、該第２の高周波電力導入手段は該円筒状基体の配置円内に配置され、該第１の高周波電力導入手段に印加する高周波電力と該第２の高周波電力導入手段に印加する高周波電力を独立に制御可能な制御手段を有し、該第１の高周波電力導入手段及び該第２の高周波電力導入手段に周波数の異なる複数の高周波電力を導入可能な高周波電源を有することを特徴とする堆積膜形成装置に関する。
【００３１】
（１４）（１３）に記載の堆積膜形成装置において、前記第１の高周波電力導入手段に印加する複数の高周波電力のうち上位２つの電力値をとる高周波電力の周波数をｆ１、ｆ２としたとき、以下の条件（ｊ）を満たし、
前記第２の高周波電力導入手段に印加する複数の高周波電力のうち上位２つの電力値をとる高周波電力の周波数をｆ１’、ｆ２’としたとき、以下の条件（ｋ）を満たす高周波電力を導入可能な高周波電源を有することを特徴とする堆積膜形成装置に関する。
【００３２】
（ｊ）１０ＭＨｚ≦ｆ２＜ｆ１≦２５０ＭＨｚ
（ｋ）１０ＭＨｚ≦ｆ２’＜ｆ１’≦２５０ＭＨｚ
（１５）（１３）から（１４）に記載の堆積膜形成装置において、前記第１の高周波電力導入手段に印加する高周波電力の周波数ｆ１と前記第２の高周波電力導入手段に印加する高周波電力の周波数ｆ１’とが以下の条件（ｌ）を満たす高周波電力を導入可能な高周波電源を有することを特徴とする堆積膜形成装置に関する。
【００３３】
（ｌ）ｆ１＝ｆ１’
（１６）（１３）から（１５）に記載の堆積膜形成装置において、前記第１の高周波電力導入手段に印加する高周波電力の周波数ｆ２と前記第２の高周波電力導入手段に印加する高周波電力の周波数ｆ２’とが以下の条件（ｍ）を満たす高周波電力を導入可能な高周波電源を有することを特徴とする堆積膜形成装置に関する。
【００３４】
（ｍ）ｆ２＝ｆ２’
（１７）（１３）から（１６）に記載の堆積膜形成装置において、前記第１の高周波電力導入手段は、前記円筒状基体の配置円の中心と同じくする同心円上に等間隔で複数設置されていることを特徴とする堆積膜形成装置に関する。
【００３５】
（１８）（１３）から（１７）に記載の堆積膜形成装置において、前記第２の高周波電力導入手段が前記円筒状基体の配置円の中心に設置されていることを特徴とする堆積膜形成装置に関する。
【００３６】
（１９）（１３）から（１８）に記載の堆積膜形成装置において、前記反応容器が前記円筒状基体を取り囲む円筒状壁を形成し、且つ前記円筒状壁の中心軸が前記円筒状基体の配置円の中心を通るように設置されていることを特徴とする堆積膜形成装置に関する。
【００３７】
（２０）（１９）に記載の堆積膜形成装置において、前記円筒状壁の少なくとも一部が誘電体で構成され、前記第１の高周波電力導入手段が前記反応容器外に配置されていることを特徴とする堆積膜形成装置に関する。
【００３８】
（２１）（１９）に記載の堆積膜形成装置において、前記円筒状壁が導電性材料で構成され、前記第１の高周波電力導入手段が前記反応容器内に配置されていることを特徴とする堆積膜形成装置に関する。
【００３９】
（２２）（１３）から（２１）に記載の堆積膜形成装置において、前記円筒状基体上に形成する堆積膜がシリコン原子を含有する非晶質材料であることを特徴とする堆積膜形成装置に関する。
【００４０】
（２３）（１３）から（２２）に記載の堆積膜形成装置において、電子写真感光体の製造に用いられることを特徴とする堆積膜形成装置に関する。
【００４１】
【発明の実施の形態】
図を用いて本発明を詳述する。図１は本発明のａ−Ｓｉ系感光体堆積膜製造装置の一例を示した模式的な概略図である。図１（ａ）は概略垂直断面図、図１（ｂ）は図１（ａ）の概略水平断面図である。
【００４２】
反応容器１０１の底面には排気口１１６が形成され、排気管の他端は不図示の排気装置に接続されている。堆積膜の形成される円筒状基体１０２は、同一円周上に等間隔で互いに平行に配置されている。基体１０２は回転軸１１３によって保持され、モータ１１４を駆動すると、減速ギア１１５を介して回転軸１１３が回転し、円筒状基体１０２はその母線方向中心軸のまわりを自転するようになっている。また、円筒状基体１０２は発熱体１１１によって加熱可能となっている。
【００４３】
同一円周上に配置された円筒状基体１０２の配置円外には、第１の高周波電力導入手段１０３が設置され、第１の高周波電源１０７、１０８から出力された高周波電力は、第１のマッチングボックス１０５を経て、第１の高周波電力導入手段１０３から成膜空間となる反応容器１０１内に供給される。
【００４４】
また、同一円周上に配置された円筒状基体１０２の配置円内には、第２の高周波電力導入手段１０４が設置され、第２の高周波電源１０９、１１０から出力された高周波電力は、第２のマッチングボックス１０６を経て、第２の高周波電力導入手段１０４から成膜空間となる反応容器１０１内に供給される。
【００４５】
反応容器１０１内には原料ガス導入手段１１２が設置され、原料ガス導入手段の他端には不図示の原料ガス供給手段が接続されている。原料ガス供給手段から所望の原料ガスを原料ガス導入手段を介して反応容器１０１中に供給する。
【００４６】
このような装置を用いた堆積膜の形成は、例えば概略以下のようにして行われる。
【００４７】
まず、円筒状基体１０２を反応容器１０１内に設置し、不図示の排気装置により排気口１１６を通して反応容器１０１内を排気する。続いて、発熱体１１１により円筒状基体１０２を所定の温度に加熱・制御する。
【００４８】
円筒状基体１０２が所定の温度となったところで、原料ガス供給手段１１２を介して、原料ガスを反応容器１０１内に導入する。原料ガスの流量が設定流量となり、また、反応容器１０１内の圧力が安定したのを確認した後、第１の高周波電源１０７、１０８から第１のマッチングボックス１０５を介して第１のカソード電極１０３へ所定の高周波電力を供給する。同様に、第２の高周波電源１０９、１１０から第２のマッチングボックス１０６を介して第２のカソード電極１０４へ所定の高周波電力を供給する。上記方法で反応容器１０１内に導入された高周波電力によって、反応容器１０１内にグロー放電が生起し、原料ガスは励起・解離して円筒状基体１０２上に堆積膜が形成される。
【００４９】
所望の膜厚の形成が行なわれた後、高周波電力の導入を止め、続いて原料ガスの供給を停止して堆積膜の形成を終える。多層構造の堆積膜を形成する場合には、同様の操作を複数回繰り返す。この場合、各層間においては、上述したように１つの層の形成が終了した時点で一旦放電を完全に停止し、次層のガス流量、圧力に設定が変更された後、再度放電を生起して次層の形成を行ってもよいし、あるいは、１つの層の形成終了後一定時間でガス流量、圧力、高周波電力を次層の設定値に徐々に変化させることにより連続的に複数層を形成してもよい。
【００５０】
堆積膜の形成中、必要に応じて、回転軸１１３を介して円筒状基体１０２をモータ１１４により所定の速度で回転させてもよい。
【００５１】
本発明においては、周波数の異なる複数の高周波電力を円筒状基体の配置円内外から高周波電力導入手段により印加し、それぞれの高周波導入手段を独立に制御することで、反応容器内に十分な密度をもった均一なプラズマが生成可能となる。
【００５２】
これは以下のような理由によるものと考えられる。図５のような円筒状基体５０２の配置円外に第１の高周波電力導入手段５０３、円筒状基体の配置円内に第２の高周波電力導入手段５０４を設置し、第１の高周波電力導入手段５０３及び第２の高周波導入手段５０４に単一の周波数の高周波電力を印加する従来の装置では、図３のような第２の高周波電力導入手段３０４のみの装置や図４のような第１の高周波電力導入手段４０３のみの装置と比べ、水平断面方向におけるプラズマの均一性は改善し、均一で良好な堆積膜が形成可能となった。しかし、単一の周波数の高周波電力を第１の高周波導入手段５０３及び第２の高周波電力導入手段５０４により反応容器内に導入するため、第１の高周波電力導入手段から導入される高周波電力により生じる定在波と第２の高周波電力導入手段から導入される高周波電力により生じる定在波の強い場所どうし、弱い場所どうしが重なり合ってしまう。その結果、垂直断面方向において導入される高周波電力の強さに変化が生じるためプラズマの不均一な分布を生じ、導入される高周波電力の弱い場所と円筒状基体が交差する場所で堆積膜の特性が低下したり、球状突起が集中したりする場合があった。
【００５３】
そこで本発明では、図１のような複数の異なる周波数の高周波電力を第１の高周波電力導入手段１０３及び第２の高周波電力導入手段１０４により印加することで、第１の高周波電力導入手段１０３から導入される高周波電力によって生じる定在波及び第２の高周波電力導入手段１０４から導入される高周波電力によって生じる定在波のムラを抑制することで均一に高周波電力を導入可能となった。そのため、第１の高周波電力導入手段から導入された高周波電力によって生じる定在波と第２の高周波電力導入手段から導入された高周波電力によって生じる定在波が重なっても、垂直断面方向において高周波電力の強弱の差が小さいことから、従来の装置形態よりも極めてプラズマの分布を均一化することが可能なった。その結果、円筒状基体長手方向及び円周方向共に膜特性及び均一性が向上、球状突起の集中及び数の低減が可能となった。
【００５４】
よって、本発明においては、円筒状基体の配置円外のみならず配置円内にも十分な密度をもったプラズマを均一に生成可能であるため、円筒状基体全周にわたって同時に膜特性及び突起が均一な膜を形成することができる。
【００５５】
本発明においては、更に以下のような構成・方法により、さらに顕著な効果を得ることができる。各々について詳述する。
【００５６】
本発明において、第１の高周波導入手段に導入される高周波電力のうち上位２つの電力値をとる高周波電力の電力値の比率Ｒ１と第２の高周波導入手段に導入される高周波電力のうち上位２つの電力値をとる高周波電力の電力値の比率Ｒ２が、Ｒ１≠Ｒ２にすることにより膜特性の均一性、球状突起の低減の効果が更に高くなる。
【００５７】
これは、円筒状基体１０２の配置円外に設置された第１の高周波電力導入手段１０３と円筒状基体１０２の配置円内に設置された第２の高周波電力導入手段１０４に印加する高周波電力の上位２つの電力値をとる高周波電力の電力値の比率（Ｒ１、Ｒ２）を変えることで、円筒状基体１０２の配置円内外におけるプラズマの状態を更に均一にすることが可能になるためである。つまり、周波数の異なる複数の高周波電力を重畳することで高周波電力により生じる定在波を抑制することが可能であるが、周波数の高い高周波電力の方が高周波電力導入手段近傍での電力の吸収が大きいため反応容器断面方向で第１（第２）の電力導入手段から遠ざかるほど電力のムラが発生してしまう。この断面方向のムラを抑制するために、第２（第１）の高周波電力導入手段に印加する上位２つの異なる周波数の電力値を調整することにより断面方向で均一な原料ガスの分解が生じ、反応容器内に均一なプラズマが生成可能となるからである。
【００５８】
更に、本発明において、第１の高周波導入手段に導入される高周波電力のうち上位２つの電力値をとる高周波電力の電力値の比率Ｒ１と第２の高周波導入手段に導入される高周波電力のうち上位２つの電力値をとる高周波電力の電力値の比率Ｒ２は、｜Ｒ１−Ｒ２｜が０．０５以上０．６以下にするとより膜特性の均一性、球状突起の低減の効果が特に高くなる。
【００５９】
これは、｜Ｒ１−Ｒ２｜を０．０５以上にすることにより前述した断面方向のムラを十分抑制可能となり、膜特性の均一性、球状突起の低減の効果が高くなる。しかし、０．６よりも大きくすると原料ガスの分解が支配する周波数が第１と第２の高周波電力導入手段とで異なる場合があり、その結果、反応容器内のプラズマの均一性を低下させる場合がある。このことから、｜Ｒ１−Ｒ２｜を０．０５以上０．６以下にすることにより極めて膜特性が均一で、且つ球状突起の少ない堆積膜の形成が可能となる。
【００６０】
本発明においては高周波電力の周波数が１０〜２５０ＭＨｚの範囲において、円筒状基体周方向での膜特性の均一性が特に高くなる。
【００６１】
これは、１０ＭＨｚよりも低い周波数領域においては、プラズマが安定して生成可能な圧力が急激に高まることに起因していると思われる。このような高い圧力においては、成膜空間中においてポリシラン等のパーティクルが生じ易く、このパーティクルが堆積膜中に取り込まれると球状突起を形成する。このパーティクルは特にシース近傍で発生しやすく、本発明においては隣接するシリンダー間でこの膜中への取り込みが生じてしまう場合がある。本発明において、高周波電力の周波数を１０ＭＨｚ以上とすることにより、このような膜中へのパーティクルの取り込みが生じず、円筒状基体全周にわたって球状突起の低減が可能となる。
【００６２】
また、２５０ＭＨｚよりも高い周波数領域においては、プラズマの均一性の差により２５０ＭＨｚ以下の場合と比べて膜特性の均一性に差が生じてしまうものと思われる。周波数が２５０ＭＨｚよりも高い周波数領域においては、電力導入手段近傍での電力の吸収が大きく、ここで電子の生成が最も頻繁に為されるため、プラズマ不均一を生じ易く、堆積膜の特性ムラにつながりやすい。２５０ＭＨｚ以下の周波数においては、電力導入手段近傍での極端な電力吸収が生じにくいため、プラズマ均一性、さらには膜特性の均一性が高くなる。
【００６３】
本発明においては、円筒状基体１０２を反応容器１０１の中央を中心とする同一円周上に沿って等間隔に配置するほうが好ましい。反応容器内に円筒状基体１０２を均一に配置することにより反応容器内の接地電位がより均一に配設されることから、更に反応容器内におけるプラズマ分布の均一性が向上し、形成される堆積膜特性の均一性の向上、球状突起の低減が可能となる。このように円筒状基体１０２を配置することにより、複数の円筒状基体上に同時に堆積膜を形成するに際して、円筒状基体間の特性ばらつき抑制が同時に達成可能となる。
【００６４】
また、本発明において、同一円周上に配置される円筒状基体１０２の数には特に制限はないが、一般的に、円筒状基体１０２の数を多くするに伴って、装置の大型化および必要とする高周波電源容量の増大をもたらすため、これらの点を考慮して適宜決定される。
【００６５】
本発明においては、高周波電力導入手段を円筒状基体の配置円と中心を同じくする同心円上に等間隔で配置することにより、各円筒状基体に及ぼす影響が均一化され、円筒状基体間での堆積膜の特性ムラが低減する。この場合、各円筒状基体に対する高周波電力導入手段の影響を均一化するという点から、高周波電力導入手段の数としては、円筒状基体と同数もしくは円筒状基体の１／２とすることが更に好ましい。円筒状基体の１／２とする場合には、近接する２つの円筒状基体との距離が等しくなるよう配置することが最適である。複数の高周波電力導入手段１０３への高周波電力の印加は、図１のように高周波電源からマッチングボックス１０５を介した後、電力導入路を分岐させて行ってもよいし、高周波電源から電力供給路を分岐させた後、複数のマッチングボックスを介して電力導入を行ってもよく、さらには、個々の第１の高周波電力導入手段ごとに別個の高周波電源およびマッチングボックスを設けてもよいが、全ての高周波電力導入手段に印加する高周波電力の周波数が完全に一致するという点、装置コストの点、装置の大きさの点から共通の高周波電源から全ての第１の高周波電力導入手段に高周波電力を印加することが好ましい。
【００６６】
第２の高周波電力導入手段１０４もまた、各円筒状基体１０２への影響を平均化するという点から、円筒状基体の配置円中心に設置するか、もしくは円筒状基体の配置円と中心を同じくする同心円上に等間隔で複数配置することが好ましい。このような配置とすることで、基体間での堆積膜特性のばらつきが更に抑制される。
【００６７】
第１の高周波電力導入手段１０３及び第２の高周波電力導入手段１０４への高周波電力供給は、第１の高周波電力導入手段１０３及び第２の高周波電力導入手段１０４の１点に行ってもよいし、また、複数の点に行ってもよい。
【００６８】
また、第１の高周波電力導入手段１０３及び第２の高周波電力導入手段１０４の形状としては特に制限はないが、放電空間内にある第２の高周波電力導入手段１０４からの膜はがれ防止の観点から、可能な限り曲面により構成されていることが好ましく、特に円筒状が好ましい。第１の高周波電力導入手段に関しても図２に示すように第１の高周波導入手段２０３が放電空間内にある場合には、第２の高周波導入手段２０４と同様に可能な限り曲面により構成されていることが好ましく、特に円筒状が好ましい。
【００６９】
更に、第１の高周波電力導入手段２０３及び第２の高周波電力導入手段２０４の表面は、膜の密着性を向上し、膜剥れを防止し、成膜中のダストを抑制する目的から、粗面化されていることが望ましい。
【００７０】
また、膜の密着性向上の観点から、第１の高周波電力導入手段１０３と第２の高周波電力導入手段１０４の表面はセラミックス材で被覆されていることが効果的である。被覆の具体的手段に特に制限はないが、例えば、セラミックス等の筒材により、第１の高周波電力導入手段１０３と第２の高周波電力導入手段１０４を覆うように装着してもよい。具体的なセラミックス材料としては、アルミナ、二酸化チタン、窒化アルミニウム、窒化ホウ素、ジルコン、コージェライト、ジルコン−コージェライト、酸化珪素、酸化ベリリウムマイカ系セラミックス等が挙げられる。また、上記材料をＣＶＤ法、溶射等の表面コーティング法により、第１の高周波電力導入手段１０３と第２の高周波電力導入手段１０４の表面をコーティングしてもよい。コーティング法の中でも溶射は、コスト面から、あるいはコーティング対象物の大きさ・形状の制限を受けにくいため好ましい。第１の高周波電力導入手段１０３と第２の高周波電力導入手段１０４の表面を被覆するセラミックス材の厚さは特に制限はないが、耐久性および均一性を増すため、また高周波電力吸収量、製造コストの面から１μｍ〜１０ｍｍが好ましく、１０μｍ〜５ｍｍがより好ましい。
【００７１】
本発明においては、複数の円筒状基体を取り囲み、かつ中心軸が円筒状基体の配置円の中心を通るように設置された円筒状壁の内部において、原料ガスを分解して堆積膜形成を行う構成とすることにより、各円筒状基体と成膜空間壁面の距離が等しくなり各円筒状基体上で膜の堆積に寄与する成膜空間体積が等しくなることから常に全ての円筒状基体に対して同量の活性種が到達することから各円筒状基体間での堆積膜特性の差が生じにくくなる。
【００７２】
反応容器１０１の形状に関しては、どのような形状のものであっても本発明の効果は得られるが、前述したように、原料ガスが分解される成膜空間が，円柱状領域に制限されるように壁面が設けられていることが好ましい。この場合、必ずしも反応容器１０１そのものが円筒状である必要はなく、例えば、角状の反応容器内に円筒状の成膜空間壁を設けてもよい。成膜空間を円柱状領域に制限するに際しては、円柱状成膜空間の中心軸が円筒状基体１０１の配置円の中心を通るようにする方が好ましい。これは、このような成膜空間壁の表面は、膜はがれ防止のため、第１の高周波電力導入手段１０３及び第２の高周波電力導入手段１０４の表面と同様に、粗面化、セラミックスによる被覆、加熱・冷却を行うことが効果的である。
【００７３】
また、本発明においては、このように円筒状壁の内部において原料ガスを分解して堆積膜形成を行うに際して、円筒状壁面の少なくとも一部を非導電性材料で構成し、該円筒状壁面の外部から高周波電力を導入することで更なる効果を得ることができる。すなわち、このような構成とすることで、高周波電力導入手段への膜付着による原料ガスのロスがなくなり、原料ガス利用効率が向上する。この結果、生産コストの低下が可能となる。さらに、堆積膜形成中に高周波電力導入手段表面からの膜はがれが生じないため、成膜空間中のダストが減少し、球状突起の減少を可能にする。
【００７４】
さらに本発明においては、図１に示すように、原料ガスが分解される成膜空間を、少なくとも一部が非導電性材料で構成された円筒状壁１１７により円柱状領域に制限し、円柱状成膜空間の中心軸が円筒状基体１０２配置円の中心を通る構成とし、さらに、円筒状基体１０２の配置円外に設置された第１の高周波電力導入手段１０３を円柱状壁１０１外部に位置させることにより、原料ガスの利用効率が向上し、同時に、球状突起の抑制が可能となる。図１において、１０１は円筒状壁であり、少なくとも一部が非導電性材料で構成されている。具体的な非導電性材料としては、アルミナ、二酸化チタン、窒化アルミニウム、窒化ホウ素、ジルコン、コージェライト、ジルコン−コージェライド酸化珪素、酸化ベリリウムマイカ系セラミックス等が挙げられる。これらのうち、高周波電力の吸収が少ないという点から、特にアルミナが好適である。
【００７５】
また、中心軸が円筒状基体１０２配置円の中心を通り、一定電位に維持された円筒状導電性シールドを、円筒状壁面１０１外に設置された第１の高周波電力導入手段１０３を取り囲むように設けるのが、放出される高周波電力の均一性を向上する上で好適である。この円筒状導電性シールドは反応容器１０１が兼ねる構成としてもよい。
【００７６】
本発明においては、第１の高周波電力導入手段に印加する高周波電力の発振源と第２の高周波電力導入手段に印加する高周波電力の発振源を同一にしてもよい。これにより、位相差を常に一定に維持可能となるため、良好な堆積膜を更に安定して、再現性良く形成することが可能となる。
【００７７】
この原因については、発振源が異なる場合、２つの電源において発振周波数を完全に一致させることが困難であり、この発振周波数のずれによって、堆積膜形成中、あるいは堆積膜形成ロット毎に位相差が変化してしまうことに起因すると考えられる。この位相差によって、プラズマ中で生成される活性種の種類・比率が変化してしまい、また、場合によってはプラズマが不安定となってしまう。
【００７８】
第１の高周波電力導入手段１０３及び第２の高周波電力導入手段１０４へ導入される高周波電力を独立した２つの電源およびマッチングボックスを用いる等の手段により各々独立に電力制御する。また、第１の高周波電力導入手段１０３に印加する高周波電力の発振源と第２の高周波電力導入手段１０４に印加する高周波電力の発振源を同一とすることが好ましい。
【００７９】
原料ガス供給手段１１２の数、設置位置は特に制限はないが、反応容器内へ均一に原料ガスを供給できるように設置することが効果的である。
【００８０】
このような本発明を用いることにより、例えば図８に示すようなａ−Ｓｉ系電子写真用光受容部材が形成可能である。
【００８１】
図８（ａ）に示す電子写真用感光体８００は、支持体８０１の上に、水素原子またはハロゲン原子を構成要素として含むアモルファスシリコン（以下「ａ−Ｓｉ：Ｈ，Ｘ」と表記する。）を有する光導電性を有する光導電層８０２が設けられている。
【００８２】
図８（ｂ）に示す電子写真用感光体８００は、支持体８０１の上に、ａ−Ｓｉ：Ｈ，Ｘからなり光導電性を有する光導電層８０２と、アモルファスシリコン系（又はアモルファス炭素系）表面層８０３が設けられて構成されている。
【００８３】
図８（ｃ）に示す電子写真用感光体８００は、支持体８０１の上に、アモルファスシリコン系電荷注入阻止層８０４と、ａ−Ｓｉ：Ｈ，Ｘからなり光導電性を有する光導電層１２０２と、アモルファスシリコン系（又はアモルファス炭素系）表面層８０３が設けられて構成されている。
【００８４】
図８（ｄ）に示す電子写真用感光体８００は、支持体８０１の上に、光導電層８０２が設けられている。この光導電層８０２はａ−Ｓｉ：Ｈ，Ｘからなる電荷発生層８０５及び電荷輸送層８０６とからなり、その上にアモルファスシリコン系（又はアモルファス炭素系）表面層８０３が設けられている。
【００８５】
【実施例及び比較例】
以下、実施例及び比較例により本発明を更に詳しく説明するが、本発明はこれらにより何ら制限されるものではない。
【００８６】
＜実施例１＞
図２に示す堆積膜形成装置を用い、円筒状基体（直径８０ｍｍ、長さ３５８ｍｍの鏡面加工を施した円筒状のアルミニウムシリンダー２０２）上に下記表１に示す条件で、阻止層、光導電層、表面層の順に成膜を行い、電子写真感光体を作製した。このとき、周波数が１０５ＭＨｚである高周波電力を出力可能な第１の高周波電源２０７、２０９及び周波数が６０ＭＨｚである高周波電力を出力可能な第２の高周波電源２０８、２１０を用いた。また、電子写真感光体作製時に用いる各ガス種は各層内で一定の流量とした。
【００８７】
【表１】

【００８８】
表１のＰ１は、第１の高周波導入手段から印加する高周波電力において、周波数が高い方（１０５ＭＨｚ）の電力値であり、Ｐ２は周波数の低い方（６０ＭＨｚ）の電力値である。また、表１のＰ’１は、第２の高周波導入手段から印加する高周波電力において、周波数が高い方（１０５ＭＨｚ）の電力値であり、Ｐ’２は周波数の低い方（６０ＭＨｚ）の電力値である。更に、表１のＲ１は第１の高周波電力導入手段から印加する全電力値に対するＰ２の比率であり、Ｒ２は第２の高周波電力導入手段から印加する全電力値に対するＰ２’の比率である。
【００８９】
上記条件で作製した電子写真感光体の球状突起数、膜厚ムラ、帯電能ムラ及び感度ムラを下記の条件により測定した。
【００９０】
【球状突起数】
球状突起数の測定は、３０ｍｍ×２５１ｍｍの範囲内にある長径１０μｍ以上の球状突起の数を測定した。測定場所は電子写真感光体の中央を０ｍｍ、垂直方向上を＋、垂直方向下を−とし、電子写真感光体の長手方向＋１３０ｍｍ、＋９０ｍｍ、０ｍｍ、−９０ｍｍ、−１３０ｍｍの位置を中心とし、幅３０ｍｍを周方向で一周（２５１ｍｍ）にある計５点の球状突起の合計を求めた。同様に６本のドラムを測定し、６本の球状突起数の平均を球状突起突起数とした。従って、球状突起数が少ないほど良好であることを示す。
【００９１】
【膜厚ムラ】
膜厚ムラの測定は、電子写真感光体の長手方向において中心を０ｍｍとし、０ｍｍから上下２０ｍｍ間隔で計１７点の膜厚を測定し、測定値の最大値と最小値の差を求め、６本の電子写真感光体の平均を膜厚ムラとした。従って、膜厚ムラが小さいほど良好であることを示す。
【００９２】
【帯電能ムラ】
帯電能ムラの測定は、作製した電子写真感光体を電子写真装置（評価用に改造したキヤノン製ｉＲ５０００）にセットして電位特性の評価を行った。その際、プロセススピード２６５ｍｍ／ｓｅｃ、前露光量（波長６６０ｎｍのＬＥＤ）４ｌｕｘ・ｓｅｃ、帯電器の電流値１０００μＡの条件にて電子写真装置の現像器位置にセットした表面電位計（ＴＲＥＫ社のＭｏｄｅｌ３４４）の電位センサーにより像露光（波長６５５ｎｍの半導体レーザー）を照射しない状態での感光体の表面電位を測定し、それを帯電能とした。測定場所は、膜厚測定と同じ電子写真感光体の長手方向＋１３０ｍｍ、＋９０ｍｍ、０ｍｍ、−９０ｍｍ、−１３０ｍｍの位置で帯電能を測定し、測定値の最大値と最小値の差を求め、６本の電子写真感光体の平均を帯電能ムラとした。従って、帯電能ムラが小さいほど良好であることを示す。
【００９３】
【感度ムラ】
感度ムラの測定は、帯電能ムラ測定と同じ条件で表面電位が４００Ｖ（暗電位）になるように帯電器の電流値を調整した後、像露光（波長６５５ｎｍの半導体レーザー）を照射し、像露光光源の光量を調整して、表面電位が５０Ｖ（明電位）となるようにし、そのときの露光量を感度とした。測定場所は膜厚測定と同じ電子写真感光体の長手方向＋１３０ｍｍ、＋９０ｍｍ、０ｍｍ、−９０ｍｍ、−１３０ｍｍの位置で感度を測定し、測定値の最大値と最小値の差を求め、６本の電子写真感光体の平均を感度ムラとした。従って、この長手方向の感度ムラが小さいほど良好であることを示す。
【００９４】
＜比較例１＞
図５に示す堆積膜形成装置を用い、下記表２に示す条件により実施例１と同様に電子写真感光体を作製した。このとき、高周波電源５０７、５０９としては周波数が１０５ＭＨｚである高周波電力を出力可能な電源を用いた。
【００９５】
【表２】

【００９６】
表２のＰ１は、第１の高周波導入手段から印加する高周波電力（１０５ＭＨｚ）の電力値であり、Ｐ１’は、第２の高周波導入手段から印加する高周波電力（１０５ＭＨｚ）の電力値である。
【００９７】
上記条件により作製した電子写真感光体の球状突起数、膜厚ムラ、帯電能ムラ及び感度ムラを実施例１と同様に求めた。
【００９８】
実施例１及び比較例１によって得られた球状突起数、膜厚ムラ、帯電能ムラ及び感度ムラについて、比較例１の各測定値を１００として相対評価を行った。この結果を表３に示す。
【００９９】
【表３】

【０１００】
表３より、配置円内外の高周波電量導入手段から単一の周波数の高周波電力を反応容器内に導入する場合と、円筒状基体の配置円内外から複数の異なる周波数の高周波電力を反応容器内に導入する場合とでは、複数の異なる周波数の高周波電力を円筒状基体の配置円内外にある高周波電力導入手段に印加する方が、より単一の周波数の高周波電力を印加するよりも良好となった。
【０１０１】
＜実施例２＞
図１に示す堆積膜形成装置を用い、円筒状基体（直径８０ｍｍ、長さ３５８ｍｍの鏡面加工を施した円筒状のアルミニウムシリンダー１０２）上に、下記表４に示す条件で、阻止層、光導電層、表面層の順に成膜を行い、電子写真感光体を作製した。高周波電源は、周波数が１０５ＭＨｚである高周波電力を出力可能な第１の高周波電源１０７、１０９及び周波数が７０ＭＨｚである高周波電力を出力可能な第２の高周波電源１０８、１１０を用いた。また、第１の高周波電力導入手段に印加する周波数が１０５ＭＨｚの高周波電力値と周波数が７０ＭＨｚの高周波電力値の比率を下記表５に示す条件とし、第２の高周波電力導入手段に印加する周波数が１０５ＭＨｚの高周波電力値及び周波数が７０ＭＨｚの高周波電力値の比率を表４の条件で各層内は一定とした。また、電子写真感光体作製時に用いる各ガス種は各層内で一定の流量とした。
【０１０２】
【表４】

【０１０３】
表４のＰ１は、第１の高周波導入手段から印加する高周波電力において、周波数が高い方（１０５ＭＨｚ）の電力値であり、Ｐ２は周波数の低い方（７０ＭＨｚ）の電力値である。また、表４のＰ１’は、第２の高周波導入手段から印加する高周波電力において、周波数が高い方（１０５ＭＨｚ）の電力値であり、Ｐ２’は周波数の低い方（７０ＭＨｚ）の電力値である。更に、表４のＲ１は第１の高周波電力導入手段から印加する全電力値に対するＰ２の比率であり、Ｒ２は第２の高周波電力導入手段から印加する全電力値に対するＰ２’の比率である。
【０１０４】
【表５】

【０１０５】
上記条件により作製した電子写真感光体の球状突起数、膜厚ムラ、帯電能ムラ及び感度ムラを実施例１と同様に求めた。
【０１０６】
実施例２の各条件Ｉ〜ＶＩによって得られた球状突起数、膜厚ムラ、帯電能ムラ及び感
度ムラについて、ＩＩの各測定値を１００として相対評価を行った。この結果を表６に示す
。
【０１０７】
【表６】

【０１０８】
表６より、配置円内の第２の高周波電力導入手段から反応容器内に導入される周波数が１０５ＭＨｚ及び７０ＭＨｚである高周波電力の電力値の比率を一定にし、配置円外の第１の高周波電量導入手段から反応容器内に導入される周波数が１０５ＭＨｚ及び７０ＭＨｚである高周波電力の電力値の比率を変化させたところ、第１の高周波電力導入手段と第２の高周波電力導入手段から印加された周波数が１０５ＭＨｚ及び７０ＭＨｚである高周波電力の電力値の比率Ｒ１及びＲ２が同じ比率であるよりもＲ１とＲ２の差の絶対値が０．０５から０．６の間では上記全て評価において良好であったが、Ｒ１とＲ２の差が０．６より大きくなると若干良好となる程度であった。
【０１０９】
この結果より、第１の高周波電力導入手段の上位２つの電力値をとる高周波電力のうち、周波数が高い方の高周波電力の電力値Ｐ１と周波数が低い方の高周波電力の電力値Ｐ２の比率Ｒ１と第２の高周波電力導入手段の上位２つの電力値をとる高周波電力のうち、周波数が高い方の高周波電力の電力値Ｐ’１と周波数が低い方の高周波電力の電力値Ｐ’２の比率Ｒ２が、Ｒ１＝Ｒ２の条件よりもＲ１≠Ｒ２の条件の方が良好であった。その中でも０．０５≦｜Ｒ１−Ｒ２｜≦０．６の条件が更に良好であった。
【０１１０】
＜実施例３＞
下記表７に示す条件により実施例２と同様に電子写真感光体を作製した。このとき、高周波電源として、周波数が１０５ＭＨｚである高周波電力を出力可能な第１の高周波電源１０７、１０９及び周波数が５０ＭＨｚである高周波電力を出力可能な第２の高周波電源１０８、１１０を用い、第１の高周波電力導入手段に印加する周波数が１０５ＭＨｚの高周波電力値と周波数が７０ＭＨｚの高周波電力値の比率を下記表７の条件で各層内は一定とし、第２の高周波電力導入手段に印加する周波数が１０５ＭＨｚの高周波電力値及び周波数が７０ＭＨｚの高周波電力値の比率を下記表８の条件とした。
【０１１１】
【表７】

【０１１２】
【表８】

【０１１３】
表７のＰ１は、第１の高周波導入手段から印加する高周波電力において、周波数が高い方（１０５ＭＨｚ）の電力値であり、Ｐ２は周波数の低い方（５０ＭＨｚ）の電力値である。また、表４のＰ１’は、第２の高周波導入手段から印加する高周波電力において、周波数が高い方（１０５ＭＨｚ）の電力値であり、Ｐ２’は周波数の低い方（５０ＭＨｚ）の電力値である。更に、表４のＲ１は第１の高周波電力導入手段から印加する全電力値に対するＰ２の比率であり、Ｒ２は第２の高周波電力導入手段から印加する全電力値に対するＰ２’の比率である。
【０１１４】
上記条件により作製した電子写真感光体の球状突起数、膜厚ムラ、帯電能ムラ及び感度ムラを実施例１と同様に求めた。
【０１１５】
実施例３の各条件Ｉ〜ＶＩによって得られた球状突起数、膜厚ムラ、帯電能ムラ及び感度ムラについて、ＩＩの各測定値を１００として相対評価を行った。この結果を表９に示す。
【０１１６】
【表９】

【０１１７】
表９より、配置円外の第１の高周波電力導入手段から反応容器内に導入される周波数が１０５ＭＨｚ及び５０ＭＨｚである高周波電力の電力値の比率を一定にし、配置円内の第２の高周波電量導入手段から反応容器内に導入される周波数が１０５ＭＨｚ及び５０ＭＨｚである高周波電力の電力値の比率を変化させたところ、第１の高周波電力導入手段と第２の高周波電力導入手段から印加された周波数が１０５ＭＨｚ及び５０ＭＨｚである高周波電力の電力値の比率Ｒ１及びＲ２が同じ比率であるよりもＲ１とＲ２の差の絶対値が０．０５から０．６の間では上記全て評価において良好であったが、Ｒ１とＲ２の差が０．６より大きくなると若干良好となる程度であった。
【０１１８】
この結果より、第１の高周波電力導入手段の上位２つの電力値をとる高周波電力のうち、周波数が高い方の高周波電力の電力値Ｐ１と周波数が低い方の高周波電力の電力値Ｐ２の比率Ｒ１と第２の高周波電力導入手段の上位２つの電力値をとる高周波電力のうち、周波数が高い方の高周波電力の電力値Ｐ’１と周波数が低い方の高周波電力の電力値Ｐ２’の比率Ｒ２が、Ｒ１＝Ｒ２の条件よりもＲ１≠Ｒ２の条件の方が良好であった。その中でも０．０５≦｜Ｒ１−Ｒ２｜≦０．６の条件が更に良好であった。
【０１１９】
【発明の効果】
以上説明したように本発明によれば、高周波−ＰＣＶＤ法による堆積膜形成において、堆積膜特性の均一性が高く且つ球状突起が減少することから、従来の電子写真感光体を使用するよりも画像の均一性が向上し画像欠陥が極めて少なくできるため、近年要求されている高画質に対応できる堆積膜の形成が可能となる。
【図面の簡単な説明】
【図１】（ａ）は本発明の第１の実施形態を示す堆積膜形成装置の模式的な垂直断面図である。（ｂ）は（ａ）の水平断面図である。
【図２】（ａ）は本発明の第２の実施形態を示す堆積膜形成装置の模式的な垂直断面図である。（ｂ）は（ａ）の水平断面図である。
【図３】（ａ）は従来のＶＨＦ帯の周波数を用いたＶＨＦプラズマＣＶＤ法による堆積膜形成装置の一例を示した模式的な垂直断面図である。（ｂ）は（ａ）の水平断面図である。
【図４】（ａ）は従来のＶＨＦ帯の周波数を用いたＶＨＦプラズマＣＶＤ法による堆積膜形成装置の一例を示した模式的な垂直断面図である。（ｂ）は（ａ）の水平断面図である。
【図５】（ａ）は従来のＶＨＦ帯の周波数を用いたＶＨＦプラズマＣＶＤ法による堆積膜形成装置の一例を示した模式的な垂直断面図である。（ｂ）は（ａ）の水平断面図である。
【図６】本発明の第３の実施形態を示す堆積膜形成装置の模式的な垂直断面図である。
【図７】（ａ）は従来のＶＨＦ帯の周波数を用いたＶＨＦプラズマＣＶＤ法による堆積膜形成装置の一例を示した模式的な垂直断面図である。（ｂ）は（ａ）の水平断面図である。
【図８】本発明により形成可能な電子写真用光受容部材の層構成の一例を示した図である。
【符号の説明】
１０１、２０１、３０１、４０１、５０１、６０１、７０１反応容器
１０２、２０２、３０２、４０２、５０２、６０２、７０２円筒状基体
１０３、２０３、３０３、４０３、５０３、６０３、７０３第１の高周波電極
１０４、２０４、６０４第２の高周波電極
１０５、２０５、６０５第１のマッチングボックス
１０６、２０６、６０６第２のマッチングボックス
１０７、１０９、２０７、２０９、４０７、５０７第１の高周波電源
１０８、１１０、２０８、２１０、３０８、５０８、７０８第２の高周波電源
１１１、２１１、３１１、４１１、５１１、６１１、７１１ヒータ
１１２、２１２、３１２、４１２、５１２、６１２、７１２原料ガス導入手段
１１３、２１３、３１３、４１３、５１３、６１３、７１３回転軸
１１４、２１４、３１４、４１４、５１４、６１４、７１４モータ
１１５、２１５、３１５、４１５、５１５、６１５、７１５減速ギア
１１６、２１６、３１６、４１６、５１６、６１６、７１６排気口
１１７円筒状壁
１１８シールド
６１９第１の高周波発振器
６２０第２の高周波発振器
６２１アンプ
６２２アンプ
６２３アンプ
６２４アンプ
８００電子写真用感光体
８０１支持体
８０２光導電層
８０３表面層
８０４電荷注入阻止層
８０５電荷発生層
８０６電荷輸送層[0001]
[Industrial application fields]
The present invention forms a light receiving member on a substrate to be processed using a deposited film, particularly a functional film, in particular, a semiconductor device using plasma generated by high-frequency power, a deposited film such as an electrophotographic photosensitive member. The present invention relates to a suitable deposited film forming method and apparatus.
[0002]
[Prior art]
Conventionally, vacuum processing methods for forming semiconductor devices, electrophotographic photoreceptors, image input line sensors, imaging devices, photovoltaic devices, etc. include plasma CVD, ion plating, plasma etching, etc. A deposition film forming method using plasma generated by electric power is known, and many apparatuses for this purpose have been put into practical use.
[0003]
For example, a deposition film forming method using the plasma CVD method, that is, a method of forming a deposited film by decomposing a source gas by glow discharge of high-frequency power and depositing the decomposed species on a substrate to be processed is preferable. It has been put into practical use as a film forming means. As an example using this method, formation of an amorphous silicon (hereinafter referred to as “a-Si”) thin film using silane gas as a source gas is known, and various apparatuses for that purpose have been proposed.
[0004]
As an apparatus for forming a deposited film of an a-Si thin film using such a plasma CVD method, a conventional deposited film forming apparatus using a VHF plasma CVD method (hereinafter referred to as “VHF-PCVD”) using a frequency in the VHF band, Specifically, FIG. 7 shows a schematic configuration diagram showing an example of an electrophotographic photoreceptor forming apparatus. FIG. 7A is a schematic view showing a longitudinal section of a conventional electrophotographic photoreceptor forming apparatus, and FIG. 7B is a cross-sectional view of the electrophotographic photoreceptor forming apparatus shown in FIG. It is a schematic diagram which shows. An exhaust pipe is integrally formed on the side surface of the reaction vessel 701, and an exhaust means (not shown) is connected to the other end of the exhaust pipe. The cylindrical substrate 702 is disposed so as to surround the central portion of the reaction vessel 701, and is configured to be held by a rotating shaft 713 and heated by a heater 711. The rotating shaft 713 is rotated by the motor 714 so that the cylindrical base body 702 rotates.
[0005]
The source gas is introduced into the reaction vessel 701 through a source gas introduction pipe 712 from a source gas supply means (not shown). High frequency power in the VHF band is introduced from the cathode electrode 704 into the reaction vessel 701 through the high frequency power supply 709 and the high frequency matching box 706. At this time, since the cylindrical base body 702 is maintained at the ground potential via the rotating shaft 713, it acts as an anode electrode.
[0006]
Formation of a deposited film using such a conventional electrophotographic photoreceptor forming apparatus is performed in the following procedure. First, the cylindrical substrate 702 is installed in the reaction vessel 701, and the inside of the reaction vessel is exhausted by an exhaust device (not shown). Subsequently, the cylindrical substrate 702 is controlled to a predetermined temperature by the heater 711. Thereafter, a raw material gas is introduced into the reaction vessel 701 from the raw material gas supply means via the raw material gas introduction pipe 712, and high frequency power in the VHF band is introduced into the reaction vessel 701 from the cathode electrode 704. Thereby, a deposited film is formed on the cylindrical substrate 702. After the formation of the desired film thickness, the supply of the high frequency power and the source gas is stopped and the formation of the deposited film is completed. By repeating the same operation a plurality of times, a light-receiving layer having a desired multilayer structure can be formed. By rotating the cylindrical substrate 701 during the formation of the deposited film, a uniform deposited film is formed over the entire circumference of the surface of the cylindrical substrate 701.
[0007]
A high-quality deposited film is formed by such an electrophotographic photosensitive member forming apparatus, but the electrophotographic photosensitive member forming method and apparatus are being improved for further quality improvement.
[0008]
A deposition film forming method in which a plurality of cylindrical substrates are arranged at equal intervals on the same circumference in a reaction vessel, and cathode electrodes are arranged inside and outside the arrangement circle of the cylindrical substrate to form a deposition film on the cylindrical substrate, and The technology of the apparatus is disclosed (for example, see Patent Document 1). It has been shown that the effect of improving the uniformity of deposited film characteristics can be obtained by forming a deposited film on a cylindrical substrate using this deposited film forming method and apparatus.
[0009]
[Patent Document 1]
JP-A-11-092932 (pages 14 to 18, FIGS. 1, 8, and 10)
[0010]
[Problems to be solved by the invention]
With the conventional deposited film forming method and apparatus described above, it is possible to form a good deposited film by improving the uniformity of deposited film characteristics, and it is also possible to improve productivity by improving yield. ing. However, as the quality of products progresses, the market demand for products is increasing day by day, and there is a need for a deposited film forming method and apparatus capable of producing higher quality products. .
[0011]
For example, in electrophotographic photoreceptors, demands for speeding up, downsizing, and cost reduction of electrophotographic apparatuses are increasing. Therefore, it is indispensable to realize the characteristics of the electrophotographic photoreceptor that can realize these, and to improve the yield rate at the time of manufacturing the electrophotographic photoreceptor. Further, in recent years, digital electrophotographic devices and color electrophotographic devices have been remarkably widespread. Since these electrophotographic devices are not limited to text originals, there are increasing opportunities to output images such as photographs and designs. The demand for higher image quality is also increasing. In order to realize these, it is indispensable to improve the characteristics of the photoreceptor, specifically, the charging ability and the uniformity of sensitivity, and to reduce minute protrusions on the photoreceptor surface that cause image defects.
[0012]
With the aim of improving the characteristics of the photosensitive member and reducing the fine protrusions on the surface of the photosensitive member, conditions for forming the deposited film and the layer configuration of the deposited film have been optimized. Improvements in terms of forming equipment are also strongly desired.
[0013]
Under such circumstances, there is still room for improvement in improving the deposited film characteristics in the conventional deposited film forming apparatus and deposited film forming method described above.
[0014]
For example, in the deposition film forming method and apparatus using the VHF-CVD method, the deposition rate of the deposition film is formed by forming plasma on the substrate by generating plasma using high-frequency power in the VHF band or in the vicinity thereof. Improvements in the properties of deposited films can be achieved. However, when using high-frequency power in such a frequency band, the wavelength of the high-frequency power in the reaction vessel is as long as the reaction vessel, high-frequency electrode, substrate, substrate holder, etc., and the high-frequency power in the reaction vessel Becomes easier to form a standing wave. For this reason, in the above-described conventional deposited film forming method and apparatus, the standing wave causes the strength of power in the vertical direction and the cross-sectional direction in the reaction vessel, resulting in different plasma characteristics. Therefore, the deposited film formed on the substrate It was difficult to make the characteristics uniform. Further, dust or the like in the reaction vessel is adsorbed in a place where electric power is weak, and this causes a protrusion, so that it is difficult to suppress the concentration of the protrusion.
[0015]
Further, in the deposited film forming method and apparatus described in Patent Document 1, a high-frequency power is introduced from inside and outside the arrangement circle of the cylindrical substrate, and each high-frequency power is independently controlled, thereby causing a reaction vessel generated by standing waves. By reducing the strength of the electric power in the vertical direction and the cross-sectional direction, the deposition film can be formed more stably than the conventional deposition film forming method and apparatus. However, even in the deposited film forming method and apparatus, it is becoming difficult to satisfy the conditions of uniformity of deposited film characteristics and the number of image defects for realizing the high image quality currently required by the market.
[0016]
【the purpose】
Accordingly, an object of the present invention is to achieve a very high level of uniformity of the deposited film characteristics as compared with the conventional deposited film forming apparatus and further reduce the spherical projections that cause image defects, thereby increasing the market demand. It is an object of the present invention to provide a deposited film forming method and apparatus capable of forming a deposited film satisfying image quality.
[0017]
[Means for Solving the Problems]
As a result of intensive studies to achieve the above object, the present inventors have found that in a deposited film forming method and a deposited film forming apparatus, the high frequency power introduction method has a great influence on uniformity of deposited film characteristics and image defect reduction. I found. Specifically, by arranging cylindrical bases at equal intervals on the same circumference and introducing a plurality of high-frequency powers having different frequencies independently from inside and outside the placement base of the cylindrical bases, a plurality of bases are provided. The inventors have found that it is difficult to form spherical protrusions on the top, and that a deposited film having good characteristics can be formed uniformly, and the present invention has been completed.
[0018]
In particular,
(1) A plurality of cylindrical substrates are disposed in a depressurized reaction vessel, and the raw material gas supplied into the reaction vessel is introduced from the first high-frequency power introducing means and the second high-frequency power introducing means. In the deposited film forming method of forming a deposited film on the cylindrical substrate, the first high-frequency power introducing means introduces high-frequency power from outside the arrangement circle of the cylindrical substrate, and the second high-frequency power is introduced. High-frequency power is introduced from the arrangement circle of the cylindrical base body by the power introduction means, and the high-frequency power applied to the first high-frequency power introduction means and the high-frequency power applied to the second high-frequency power introduction means are independently controlled. Then, the present invention relates to a deposited film forming method, wherein a deposited film is formed by introducing a plurality of high frequency powers having different frequencies into the first high frequency power introducing unit and the second high frequency power introducing unit.
[0019]
(2) In the deposited film forming method described in (1), the power value of the higher frequency among the high-frequency powers that take the upper two power values of the plurality of high-frequency powers applied to the first high-frequency power introduction means. P1, the lower frequency power value is P2, R1 is the following (a), and the frequency among the high frequency powers taking the upper two power values of the plurality of high frequency power applied to the second high frequency power introducing means is The higher power value is P1 ′, the lower power value is P2 ′, R2 is the following (b), and high frequency power satisfying the following condition (c) is introduced to form a deposited film. The present invention relates to a method for forming a deposited film.
[0020]
(A) R1 = P2 / (P1 + P2)
(B) R2 = P2 ′ / (P1 ′ + P2 ′)
(C) R1 ≠ R2
(3) In the deposited film forming method according to any one of (1) to (2), the frequency of the high-frequency power that takes the upper two power values among the plurality of high-frequency power applied to the first high-frequency power introduction means is f1 and When f2, the following conditions (d) and (e) are satisfied,
The following conditions (f) and (g) are satisfied, where f1 ′ and f2 ′ are the frequencies of the high-frequency power that takes the upper two power values among the plurality of high-frequency power applied to the second high-frequency power introduction means. The present invention relates to a deposited film forming method, wherein a deposited film is formed by introducing high-frequency power.
[0021]
(D) 10 MHz ≦ f2 <f1 ≦ 250 MHz
(E) 0.1 ≦ R1 ≦ 0.9
(F) 10 MHz ≦ f2 ′ <f1 ′ ≦ 250 MHz
(G) 0.1 ≦ R2 ≦ 0.9
(4) In the deposited film forming method according to any one of (1) to (3), a plurality of high-frequency powers are introduced from the first high-frequency power introducing means arranged at equal intervals on the same concentric circle as the center of the arrangement circle of the cylindrical substrate. The present invention relates to a deposited film forming method, wherein a deposited film is formed on the cylindrical substrate by introducing electric power.
[0022]
(5) In the deposited film forming method according to any one of (1) to (4), high-frequency power is introduced from the second high-frequency power introduction means installed at the center of the arrangement circle of the cylindrical substrate, and the cylindrical substrate The present invention relates to a deposited film forming method characterized by forming a deposited film thereon.
[0023]
(6) In the deposited film forming method according to any one of (1) to (5), the method includes a cylindrical wall that surrounds a plurality of cylindrical substrates and has a central axis that passes through the center of the arrangement circle of the cylindrical substrates. The present invention relates to a deposited film forming method characterized in that a deposited film is formed on the cylindrical substrate in a reaction vessel.
[0024]
(7) In the deposited film forming method according to (6), high-frequency power applied to the first high-frequency power introducing means is introduced from outside the reaction vessel to form a deposited film on the cylindrical substrate. The present invention relates to a method for forming a deposited film.
[0025]
(8) In the deposited film forming method described in (6), high-frequency power applied to the first high-frequency power introducing means is introduced from the reaction vessel to form a deposited film on the cylindrical substrate. The present invention relates to a method for forming a deposited film.
[0026]
(9) In the deposited film forming method according to (3) to (8), the frequency f1 of the high frequency power applied to the first high frequency power introducing unit and the high frequency power applied to the second high frequency power introducing unit The present invention relates to a deposited film forming method, wherein a deposited film is formed on the cylindrical substrate using high-frequency power having a frequency f1 ′ satisfying the following condition (h).
[0027]
(H) f1 = f1 ′
(10) In the deposited film forming method according to any one of (3) to (9), the frequency f2 of the high-frequency power applied to the first high-frequency power introduction unit and the high-frequency power applied to the second high-frequency power introduction unit The present invention relates to a method for forming a deposited film, wherein the deposited film is formed on the cylindrical substrate using a high-frequency power having a frequency f2 ′ satisfying the following condition (i):
[0028]
(I) f2 = f2 ′
(11) In the deposited film forming method described in (1) to (10), the deposited film formed on the cylindrical substrate is an amorphous material containing silicon atoms. About.
[0029]
(12) The deposited film forming method according to any one of (1) to (11), wherein the deposited film forming method is used for manufacturing an electrophotographic photosensitive member.
[0030]
(13) A plurality of cylindrical substrates are placed in a depressurizable reaction vessel, and the raw material gas supplied into the reaction vessel is introduced from the first high-frequency power introduction means and the second high-frequency power introduction means. In the deposited film forming apparatus that decomposes by the above and forms a deposited film on the cylindrical substrate, the cylindrical substrates are arranged at equal intervals on the same circumference, and the first high-frequency power introducing means is the cylindrical substrate. The second high-frequency power introduction means is arranged within the arrangement circle of the cylindrical base, and the high-frequency power applied to the first high-frequency power introduction means and the second high-frequency power introduction means A high-frequency power source capable of independently controlling the high-frequency power applied to the first and second high-frequency power introduction means and the second high-frequency power introduction means. A stack characterized by having The present invention relates to a deposited film forming apparatus.
[0031]
(14) In the deposited film forming apparatus described in (13), when the frequencies of the high-frequency power taking the upper two power values among the plurality of high-frequency power applied to the first high-frequency power introducing means are f1 and f2. Satisfies the following condition (j),
Introducing high-frequency power satisfying the following condition (k), where f1 ′ and f2 ′ are the frequencies of the high-frequency power taking the upper two power values among the plurality of high-frequency power applied to the second high-frequency power introduction means. The present invention relates to a deposited film forming apparatus having a high-frequency power source that can be used.
[0032]
(J) 10 MHz ≦ f2 <f1 ≦ 250 MHz
(K) 10 MHz ≦ f2 ′ <f1 ′ ≦ 250 MHz
(15) In the deposited film forming apparatus described in (13) to (14), the frequency f1 of the high-frequency power applied to the first high-frequency power introducing unit and the high-frequency power applied to the second high-frequency power introducing unit The present invention relates to a deposited film forming apparatus having a high frequency power source capable of introducing a high frequency power whose frequency f1 ′ satisfies the following condition (l).
[0033]
(L) f1 = f1 ′
(16) In the deposited film forming apparatus described in (13) to (15), the frequency f2 of the high-frequency power applied to the first high-frequency power introduction unit and the high-frequency power applied to the second high-frequency power introduction unit The present invention relates to a deposited film forming apparatus having a high frequency power source capable of introducing high frequency power satisfying the following condition (m) with a frequency f2 ′.
[0034]
(M) f2 = f2 ′
(17) In the deposited film forming apparatus according to any one of (13) to (16), a plurality of the first high-frequency power introducing means are installed at equal intervals on a concentric circle that is the same as the center of the arrangement circle of the cylindrical substrate. The present invention relates to a deposited film forming apparatus.
[0035]
(18) In the deposited film forming apparatus according to any one of (13) to (17), the second high frequency power introducing means is disposed at the center of the arrangement circle of the cylindrical substrate. Relates to the device.
[0036]
(19) In the deposited film forming apparatus described in (13) to (18), the reaction vessel forms a cylindrical wall surrounding the cylindrical substrate, and the central axis of the cylindrical wall is the cylindrical substrate. The present invention relates to a deposited film forming apparatus characterized in that it is installed so as to pass through the center of a placement circle.
[0037]
(20) In the deposited film forming apparatus according to (19), at least a part of the cylindrical wall is made of a dielectric, and the first high-frequency power introducing means is disposed outside the reaction vessel. The present invention relates to a deposited film forming apparatus.
[0038]
(21) In the deposited film forming apparatus described in (19), the cylindrical wall is made of a conductive material, and the first high-frequency power introducing means is arranged in the reaction vessel. The present invention relates to a deposited film forming apparatus.
[0039]
(22) The deposited film forming apparatus according to any of (13) to (21), wherein the deposited film formed on the cylindrical substrate is an amorphous material containing silicon atoms. About.
[0040]
(23) The deposited film forming apparatus according to any one of (13) to (22), wherein the deposited film forming apparatus is used for manufacturing an electrophotographic photosensitive member.
[0041]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic diagram showing an example of an apparatus for producing an a-Si-based photoreceptor deposited film according to the present invention. 1A is a schematic vertical sectional view, and FIG. 1B is a schematic horizontal sectional view of FIG.
[0042]
An exhaust port 116 is formed on the bottom surface of the reaction vessel 101, and the other end of the exhaust pipe is connected to an exhaust device (not shown). The cylindrical substrates 102 on which the deposited films are formed are arranged in parallel to each other at equal intervals on the same circumference. The base body 102 is held by a rotary shaft 113, and when the motor 114 is driven, the rotary shaft 113 rotates via the reduction gear 115, and the cylindrical base body 102 rotates around its central axis in the generatrix direction. The cylindrical substrate 102 can be heated by a heating element 111.
[0043]
Outside the arrangement circle of the cylindrical base body 102 arranged on the same circumference, the first high-frequency power introducing means 103 is installed, and the high-frequency power output from the first high-frequency power sources 107 and 108 is the first Through the matching box 105, the first high-frequency power introduction means 103 supplies the reaction vessel 101 into the film formation space.
[0044]
The second high-frequency power introducing means 104 is installed in the arrangement circle of the cylindrical base body 102 arranged on the same circumference, and the high-frequency power output from the second high-frequency power sources 109 and 110 is Through the second matching box 106, the second high-frequency power introducing means 104 supplies the film into the reaction vessel 101 serving as a film formation space.
[0045]
A source gas introduction unit 112 is installed in the reaction vessel 101, and a source gas supply unit (not shown) is connected to the other end of the source gas introduction unit. A desired source gas is supplied from the source gas supply means into the reaction vessel 101 via the source gas introduction means.
[0046]
Formation of a deposited film using such an apparatus is performed, for example, as follows.
[0047]
First, the cylindrical substrate 102 is installed in the reaction vessel 101, and the inside of the reaction vessel 101 is exhausted through an exhaust port 116 by an exhaust device (not shown). Subsequently, the cylindrical base 102 is heated and controlled to a predetermined temperature by the heating element 111.
[0048]
When the cylindrical substrate 102 reaches a predetermined temperature, the source gas is introduced into the reaction vessel 101 via the source gas supply means 112. After confirming that the flow rate of the source gas is the set flow rate and that the pressure in the reaction vessel 101 is stable, the first cathode electrode 103 is passed from the first high-frequency power sources 107 and 108 through the first matching box 105. A predetermined high-frequency power is supplied to Similarly, predetermined high-frequency power is supplied from the second high-frequency power sources 109 and 110 to the second cathode electrode 104 via the second matching box 106. The high frequency power introduced into the reaction vessel 101 by the above method causes glow discharge in the reaction vessel 101, and the source gas is excited and dissociated to form a deposited film on the cylindrical substrate 102.
[0049]
After the formation of the desired film thickness, the introduction of the high frequency power is stopped, and then the supply of the raw material gas is stopped to finish the formation of the deposited film. When forming a multi-layered deposited film, the same operation is repeated a plurality of times. In this case, in each layer, as described above, once the formation of one layer is completed, the discharge is once stopped completely, and after the setting is changed to the gas flow rate and pressure of the next layer, the discharge occurs again. The next layer may be formed, or a plurality of layers may be continuously formed by gradually changing the gas flow rate, pressure, and high frequency power to the set values of the next layer within a certain time after the formation of one layer is completed. It may be formed.
[0050]
During the formation of the deposited film, the cylindrical substrate 102 may be rotated at a predetermined speed by the motor 114 via the rotating shaft 113 as necessary.
[0051]
In the present invention, a plurality of high-frequency powers having different frequencies are applied from inside and outside the arrangement circle of the cylindrical substrate by high-frequency power introducing means, and each high-frequency introducing means is independently controlled, thereby providing a sufficient density in the reaction vessel. A uniform plasma can be generated.
[0052]
This is thought to be due to the following reasons. The first high-frequency power introduction means 503 is installed outside the arrangement circle of the cylindrical base body 502 as shown in FIG. 5, and the second high-frequency power introduction means 504 is installed inside the arrangement circle of the cylindrical base body. In the conventional apparatus in which high frequency power of a single frequency is applied to 503 and the second high frequency introducing means 504, the apparatus having only the second high frequency power introducing means 304 as shown in FIG. 3 or the first as shown in FIG. Compared with the apparatus using only the high-frequency power introducing means 403, the uniformity of plasma in the horizontal cross-sectional direction is improved, and a uniform and good deposited film can be formed. However, since the high frequency power of a single frequency is introduced into the reaction vessel by the first high frequency power introduction means 503 and the second high frequency power introduction means 504, it is generated by the high frequency power introduced from the first high frequency power introduction means. A place where the standing wave is strong and a place where the standing wave is generated due to the high frequency power introduced from the second high frequency power introduction means overlap each other. As a result, the intensity of the high-frequency power introduced in the vertical cross-sectional direction changes, resulting in a non-uniform distribution of plasma, and the characteristics of the deposited film at the place where the introduced high-frequency power is weak and the cylindrical substrate intersects. May decrease, or spherical protrusions may concentrate.
[0053]
Therefore, in the present invention, the first high frequency power introduction means 103 applies a plurality of high frequency powers having different frequencies as shown in FIG. 1 by the first high frequency power introduction means 103 and the second high frequency power introduction means 104. By suppressing the unevenness of the standing wave generated by the introduced high-frequency power and the standing wave caused by the high-frequency power introduced from the second high-frequency power introducing means 104, the high-frequency power can be introduced uniformly. Therefore, even if the standing wave generated by the high-frequency power introduced from the first high-frequency power introducing means and the standing wave generated by the high-frequency power introduced from the second high-frequency power introducing means overlap, Therefore, the plasma distribution can be made more uniform than in the conventional apparatus configuration. As a result, the film characteristics and uniformity are improved in both the longitudinal direction and the circumferential direction of the cylindrical substrate, and the concentration and number of spherical protrusions can be reduced.
[0054]
Therefore, in the present invention, plasma having a sufficient density can be uniformly generated not only outside the arrangement circle of the cylindrical substrate but also inside the arrangement circle. A uniform film can be formed.
[0055]
In the present invention, further remarkable effects can be obtained by the following configuration and method. Each will be described in detail.
[0056]
In the present invention, the ratio R1 of the power values of the high-frequency power that takes the upper two power values of the high-frequency power introduced into the first high-frequency introducing means and the upper two of the high-frequency powers introduced into the second high-frequency introducing means. When the ratio R2 of the power values of the high-frequency power taking two power values is set to R1 ≠ R2, the effect of reducing the uniformity of the film characteristics and the reduction of the spherical protrusions is further enhanced.
[0057]
This is because the high-frequency power applied to the first high-frequency power introduction means 103 installed outside the arrangement circle of the cylindrical base 102 and the second high-frequency power introduction means 104 installed within the arrangement circle of the cylindrical base 102 is shown. This is because the plasma state inside and outside the arrangement circle of the cylindrical substrate 102 can be made more uniform by changing the ratio (R1, R2) of the power values of the high-frequency power taking the upper two power values. In other words, it is possible to suppress standing waves generated by high-frequency power by superimposing a plurality of high-frequency powers having different frequencies. However, high-frequency power having a higher frequency absorbs power near the high-frequency power introduction means. Since it is large, the power non-uniformity occurs as the distance from the first (second) power introduction means increases in the reaction vessel cross-sectional direction. In order to suppress this non-uniformity in the cross-sectional direction, by uniformly adjusting the power values of the top two different frequencies applied to the second (first) high-frequency power introducing means, decomposition of the uniform source gas in the cross-sectional direction occurs. This is because uniform plasma can be generated in the reaction vessel.
[0058]
Furthermore, in the present invention, the ratio R1 of the power values of the high-frequency power taking the upper two power values of the high-frequency power introduced into the first high-frequency introducing means and the high-frequency power introduced into the second high-frequency introducing means When the ratio R2 of the high-frequency power taking the upper two power values is | R1-R2 | is 0.05 or more and 0.6 or less, the effect of reducing the uniformity of the film characteristics and the reduction of the spherical protrusion becomes particularly high. .
[0059]
By setting | R1-R2 | to 0.05 or more, the above-described unevenness in the cross-sectional direction can be sufficiently suppressed, and the effect of reducing the uniformity of film characteristics and the reduction of spherical protrusions is enhanced. However, if it exceeds 0.6, the frequency governed by the decomposition of the raw material gas may differ between the first and second high-frequency power introduction means, and as a result, the uniformity of the plasma in the reaction vessel is reduced. There is. Therefore, by setting | R1-R2 | to 0.05 or more and 0.6 or less, it is possible to form a deposited film having extremely uniform film characteristics and few spherical protrusions.
[0060]
In the present invention, the uniformity of the film characteristics in the circumferential direction of the cylindrical substrate is particularly high when the frequency of the high frequency power is in the range of 10 to 250 MHz.
[0061]
This seems to be due to the rapid increase in pressure at which plasma can be stably generated in a frequency region lower than 10 MHz. Under such a high pressure, particles such as polysilane are likely to be generated in the film forming space, and when these particles are taken into the deposited film, spherical protrusions are formed. Such particles are particularly likely to be generated near the sheath, and in the present invention, the particles may be taken into the membrane between adjacent cylinders. In the present invention, by setting the frequency of the high-frequency power to 10 MHz or more, such particles are not taken into the film, and spherical protrusions can be reduced over the entire circumference of the cylindrical substrate.
[0062]
Further, in a frequency region higher than 250 MHz, it is considered that a difference in uniformity of film characteristics is caused by a difference in plasma uniformity as compared with a case of 250 MHz or less. In the frequency region where the frequency is higher than 250 MHz, the power absorption in the vicinity of the power introduction means is large, and electrons are most frequently generated here, so that plasma non-uniformity is likely to occur, resulting in uneven characteristics of the deposited film. Easy to connect. At frequencies of 250 MHz or less, extreme power absorption in the vicinity of the power introduction means is unlikely to occur, so that plasma uniformity and film property uniformity are enhanced.
[0063]
In the present invention, it is preferable to arrange the cylindrical substrates 102 at equal intervals along the same circumference centering on the center of the reaction vessel 101. By uniformly disposing the cylindrical substrate 102 in the reaction vessel, the ground potential in the reaction vessel is more evenly arranged, so that the uniformity of the plasma distribution in the reaction vessel is further improved and the deposition formed It is possible to improve the uniformity of film characteristics and reduce spherical protrusions. By arranging the cylindrical base 102 in this way, it is possible to simultaneously suppress variation in characteristics between the cylindrical bases when simultaneously forming a deposited film on a plurality of cylindrical bases.
[0064]
In the present invention, the number of cylindrical bases 102 arranged on the same circumference is not particularly limited, but generally, as the number of cylindrical bases 102 is increased, the size of the apparatus is increased. In order to bring about an increase in the required high frequency power source capacity, it is appropriately determined in consideration of these points.
[0065]
In the present invention, the high-frequency power introduction means are arranged at equal intervals on a concentric circle having the same center as the arrangement circle of the cylindrical bases, so that the influence on each cylindrical base is made uniform, and between the cylindrical bases. The characteristic unevenness of the deposited film is reduced. In this case, the number of high-frequency power introduction means is more preferably the same as the number of cylindrical bases or 1/2 of the cylindrical base, from the viewpoint of equalizing the influence of the high-frequency power introduction means on each cylindrical base. . When the cylindrical base is halved, it is optimal that the distance between two adjacent cylindrical bases is the same. The application of the high frequency power to the plurality of high frequency power introduction means 103 may be performed by branching the power introduction path from the high frequency power supply through the matching box 105 as shown in FIG. After branching, power may be introduced through a plurality of matching boxes, and furthermore, a separate high-frequency power supply and matching box may be provided for each first high-frequency power introduction means. The high frequency power applied to the first high frequency power introducing means is completely the same, the cost of the apparatus, and the size of the apparatus, from the common high frequency power supply to all the first high frequency power introducing means. It is preferable to apply.
[0066]
The second high-frequency power introducing means 104 is also installed at the center of the arrangement circle of the cylindrical base, or the center of the arrangement circle of the cylindrical base is the same from the viewpoint of averaging the influence on each cylindrical base 102. It is preferable to arrange a plurality of them at equal intervals on the concentric circles. By adopting such an arrangement, variations in deposited film characteristics between substrates are further suppressed.
[0067]
The high-frequency power supply to the first high-frequency power introduction means 103 and the second high-frequency power introduction means 104 may be performed at one point of the first high-frequency power introduction means 103 and the second high-frequency power introduction means 104. Moreover, you may go to several points.
[0068]
Further, the shape of the first high-frequency power introducing means 103 and the second high-frequency power introducing means 104 is not particularly limited, but from the viewpoint of preventing film peeling from the second high-frequency power introducing means 104 in the discharge space. It is preferable that the curved surface is formed as much as possible, and a cylindrical shape is particularly preferable. As shown in FIG. 2, the first high-frequency power introducing means is configured by a curved surface as much as possible in the same manner as the second high-frequency introducing means 204 when the first high-frequency introducing means 203 is in the discharge space. In particular, a cylindrical shape is preferable.
[0069]
Further, the surfaces of the first high-frequency power introducing means 203 and the second high-frequency power introducing means 204 are roughened for the purpose of improving film adhesion, preventing film peeling, and suppressing dust during film formation. It is desirable to be faced.
[0070]
From the viewpoint of improving the adhesion of the film, it is effective that the surfaces of the first high-frequency power introducing means 103 and the second high-frequency power introducing means 104 are covered with a ceramic material. The specific means for covering is not particularly limited, but for example, the first high-frequency power introducing means 103 and the second high-frequency power introducing means 104 may be mounted so as to be covered with a cylindrical material such as ceramics. Specific examples of the ceramic material include alumina, titanium dioxide, aluminum nitride, boron nitride, zircon, cordierite, zircon cordierite, silicon oxide, and beryllium mica-based ceramics. Further, the surfaces of the first high-frequency power introducing means 103 and the second high-frequency power introducing means 104 may be coated with the above materials by a surface coating method such as CVD or thermal spraying. Among the coating methods, thermal spraying is preferable from the viewpoint of cost or because it is difficult to be limited by the size and shape of the coating object. The thickness of the ceramic material that covers the surfaces of the first high-frequency power introduction means 103 and the second high-frequency power introduction means 104 is not particularly limited. However, in order to increase durability and uniformity, the amount of high-frequency power absorption, manufacturing From the viewpoint of cost, 1 μm to 10 mm is preferable, and 10 μm to 5 mm is more preferable.
[0071]
In the present invention, a deposition film is formed by decomposing a source gas in a cylindrical wall that surrounds a plurality of cylindrical substrates and has a central axis that passes through the center of the arrangement circle of the cylindrical substrates. With this configuration, the distance between each cylindrical substrate and the wall surface of the film formation space is equal, and the volume of the film formation space that contributes to the deposition of the film on each cylindrical substrate is equal. Since the same amount of active species arrives, a difference in deposited film characteristics between the cylindrical substrates is less likely to occur.
[0072]
As for the shape of the reaction vessel 101, the effect of the present invention can be obtained with any shape. However, as described above, the film formation space where the source gas is decomposed is limited to a cylindrical region. It is preferable that the wall surface be provided. In this case, the reaction vessel 101 itself does not necessarily have a cylindrical shape. For example, a cylindrical film formation space wall may be provided in a rectangular reaction vessel. When restricting the film formation space to the columnar region, it is preferable that the central axis of the columnar film formation space passes through the center of the arrangement circle of the cylindrical substrate 101. This is because the surface of the film formation space wall is roughened and coated with ceramics in the same manner as the surfaces of the first high-frequency power introduction means 103 and the second high-frequency power introduction means 104 in order to prevent film peeling. It is effective to perform heating and cooling.
[0073]
In the present invention, when the deposited gas is formed by decomposing the source gas inside the cylindrical wall in this way, at least a part of the cylindrical wall surface is made of a non-conductive material, and the cylindrical wall surface Further effects can be obtained by introducing high-frequency power from outside. That is, with such a configuration, there is no loss of the source gas due to film adhesion to the high-frequency power introducing means, and the source gas utilization efficiency is improved. As a result, the production cost can be reduced. Furthermore, since the film does not peel off from the surface of the high-frequency power introducing means during the formation of the deposited film, dust in the film formation space is reduced, and the spherical protrusion can be reduced.
[0074]
Furthermore, in the present invention, as shown in FIG. 1, the film formation space where the source gas is decomposed is limited to a columnar region by a cylindrical wall 117 at least partially made of a non-conductive material, The central axis of the film formation space passes through the center of the arrangement circle of the cylindrical substrate 102, and the first high-frequency power introduction means 103 installed outside the arrangement circle of the cylindrical substrate 102 is positioned outside the cylindrical wall 101. By doing so, the utilization efficiency of the source gas is improved, and at the same time, it is possible to suppress the spherical protrusion. In FIG. 1, 101 is a cylindrical wall, and at least a part thereof is made of a non-conductive material. Specific examples of the nonconductive material include alumina, titanium dioxide, aluminum nitride, boron nitride, zircon, cordierite, zircon cordieride silicon oxide, and beryllium mica ceramics. Of these, alumina is particularly preferred because it absorbs less high frequency power.
[0075]
The cylindrical conductive shield maintained at a constant potential through the center axis of the cylindrical base body 102 arrangement circle surrounds the first high-frequency power introduction means 103 installed outside the cylindrical wall surface 101. Providing is preferable in improving the uniformity of the emitted high frequency power. The cylindrical conductive shield may be configured to serve as the reaction vessel 101.
[0076]
In the present invention, the high-frequency power oscillation source applied to the first high-frequency power introduction means may be the same as the high-frequency power oscillation source applied to the second high-frequency power introduction means. As a result, the phase difference can always be kept constant, so that a good deposited film can be formed more stably and with good reproducibility.
[0077]
Regarding this cause, when the oscillation sources are different, it is difficult to make the oscillation frequencies completely coincident between the two power supplies. Due to this oscillation frequency deviation, there is a phase difference during the deposition film formation or every deposition film formation lot. This is thought to be due to the change. This phase difference changes the type and ratio of active species generated in the plasma, and in some cases, the plasma becomes unstable.
[0078]
The high frequency power introduced into the first high frequency power introducing means 103 and the second high frequency power introducing means 104 is independently controlled by means such as using two independent power sources and a matching box. Further, it is preferable that the high-frequency power oscillation source applied to the first high-frequency power introduction means 103 is the same as the high-frequency power oscillation source applied to the second high-frequency power introduction means 104.
[0079]
The number and installation positions of the source gas supply means 112 are not particularly limited, but it is effective to install the source gas so that the source gas can be supplied uniformly into the reaction vessel.
[0080]
By using such an embodiment of the present invention, for example, an a-Si based electrophotographic light-receiving member as shown in FIG. 8 can be formed.
[0081]
An electrophotographic photoreceptor 800 shown in FIG. 8A has amorphous silicon (hereinafter referred to as “a-Si: H, X”) containing a hydrogen atom or a halogen atom as a constituent element on a support 801. A photoconductive layer 802 having photoconductivity is provided.
[0082]
An electrophotographic photoreceptor 800 shown in FIG. 8B has a photoconductive layer 802 made of a-Si: H, X and having photoconductivity on a support 801, and an amorphous silicon (or amorphous carbon). ) A surface layer 803 is provided.
[0083]
An electrophotographic photoreceptor 800 shown in FIG. 8C has an amorphous silicon type charge injection blocking layer 804 and a photoconductive layer 1202 made of a-Si: H, X and having photoconductivity on a support 801. And an amorphous silicon-based (or amorphous carbon-based) surface layer 803 is provided.
[0084]
An electrophotographic photoreceptor 800 shown in FIG. 8D is provided with a photoconductive layer 802 on a support 801. The photoconductive layer 802 includes a charge generation layer 805 and a charge transport layer 806 made of a-Si: H, X, and an amorphous silicon (or amorphous carbon) surface layer 803 is provided thereon.
[0085]
[Examples and Comparative Examples]
EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in detail, this invention is not restrict | limited at all by these.
[0086]
<Example 1>
Using the deposited film forming apparatus shown in FIG. 2, a blocking layer and a photoconductive layer are formed on a cylindrical substrate (cylindrical aluminum cylinder 202 having a diameter of 80 mm and a length of 358 mm), under the conditions shown in Table 1 below. Then, film formation was performed in the order of the surface layer to produce an electrophotographic photosensitive member. At this time, the first high frequency power sources 207 and 209 capable of outputting high frequency power having a frequency of 105 MHz and the second high frequency power sources 208 and 210 capable of outputting high frequency power having a frequency of 60 MHz were used. In addition, each gas type used at the time of producing the electrophotographic photosensitive member has a constant flow rate in each layer.
[0087]
[Table 1]

[0088]
P1 in Table 1 is the power value of the higher frequency (105 MHz) in the high frequency power applied from the first high frequency introducing means, and P2 is the power value of the lower frequency (60 MHz). Further, P′1 in Table 1 is the power value of the higher frequency (105 MHz) in the high frequency power applied from the second high frequency introducing means, and P′2 is the power value of the lower frequency (60 MHz). It is. Furthermore, R1 in Table 1 is the ratio of P2 to the total power value applied from the first high-frequency power introduction means, and R2 is the ratio of P2 ′ to the total power value applied from the second high-frequency power introduction means.
[0089]
The number of spherical protrusions, film thickness unevenness, chargeability unevenness, and sensitivity unevenness of the electrophotographic photosensitive member produced under the above conditions were measured under the following conditions.
[0090]
[Number of spherical protrusions]
The number of spherical protrusions was measured by measuring the number of spherical protrusions having a major axis of 10 μm or more in the range of 30 mm × 251 mm. The measurement location is 0 mm at the center of the electrophotographic photosensitive member, + at the top in the vertical direction, − at the bottom in the vertical direction, and centered on the position of the longitudinal direction of the electrophotographic photosensitive member +130 mm, +90 mm, 0 mm, −90 mm, −130 mm. A total of a total of five spherical protrusions in a circumferential direction (251 mm) of 30 mm was determined. Similarly, six drums were measured, and the average of the six spherical protrusions was defined as the number of spherical protrusions. Therefore, the smaller the number of spherical protrusions, the better.
[0091]
[Thickness unevenness]
The thickness unevenness is measured by measuring the film thickness at a total of 17 points at intervals of 20 mm from the top to the bottom in the longitudinal direction of the electrophotographic photosensitive member, obtaining a difference between the maximum value and the minimum value of 6 points. The average of the electrophotographic photosensitive member of the book was defined as film thickness unevenness. Therefore, the smaller the film thickness unevenness, the better.
[0092]
[Charging capacity unevenness]
For measuring the charging performance unevenness, the produced electrophotographic photosensitive member was set in an electrophotographic apparatus (Canon iR5000 modified for evaluation), and potential characteristics were evaluated. At that time, a surface potential meter (Model of TREK Co., Ltd.) set at the position of the developer of the electrophotographic apparatus under the conditions of a process speed of 265 mm / sec, a pre-exposure amount (LED with a wavelength of 660 nm) 4 lux · sec, and a current value of the charger of 1000 μA The surface potential of the photoreceptor in a state where no image exposure (semiconductor laser with a wavelength of 655 nm) was irradiated was measured by the potential sensor 344), and this was defined as charging ability. The measurement location is the same as the film thickness measurement in the longitudinal direction of the electrophotographic photosensitive member +130 mm, +90 mm, 0 mm, −90 mm, and −130 mm. The average of the electrophotographic photosensitive member of the book was defined as uneven charging ability. Therefore, the smaller the charging performance unevenness, the better.
[0093]
[Sensitivity unevenness]
In the measurement of sensitivity unevenness, the current value of the charger is adjusted so that the surface potential is 400 V (dark potential) under the same conditions as the measurement of uneven charging performance, and then image exposure (semiconductor laser with a wavelength of 655 nm) is irradiated to image The light quantity of the exposure light source was adjusted so that the surface potential was 50 V (bright potential), and the exposure amount at that time was defined as sensitivity. The measurement location is the same as the film thickness measurement in the longitudinal direction of the electrophotographic photosensitive member +130 mm, +90 mm, 0 mm, −90 mm, −130 mm, the sensitivity is measured, the difference between the maximum value and the minimum value is obtained, The average of the electrophotographic photosensitive member was defined as uneven sensitivity. Therefore, the smaller the sensitivity unevenness in the longitudinal direction, the better.
[0094]
<Comparative Example 1>
Using the deposited film forming apparatus shown in FIG. 5, an electrophotographic photoreceptor was produced in the same manner as in Example 1 under the conditions shown in Table 2 below. At this time, as the high frequency power sources 507 and 509, power sources capable of outputting high frequency power having a frequency of 105 MHz were used.
[0095]
[Table 2]

[0096]
P1 in Table 2 is the power value of the high-frequency power (105 MHz) applied from the first high-frequency introducing means, and P1 ′ is the power value of the high-frequency power (105 MHz) applied from the second high-frequency introducing means.
[0097]
The number of spherical protrusions, film thickness unevenness, chargeability unevenness and sensitivity unevenness of the electrophotographic photosensitive member produced under the above conditions were determined in the same manner as in Example 1.
[0098]
For the number of spherical protrusions, film thickness unevenness, charging ability unevenness, and sensitivity unevenness obtained in Example 1 and Comparative Example 1, each measurement value of Comparative Example 1 was set to 100, and relative evaluation was performed. The results are shown in Table 3.
[0099]
[Table 3]

[0100]
From Table 3, the case where high frequency power of a single frequency is introduced into the reaction vessel from the high frequency electricity introduction means inside and outside the arrangement circle, and a plurality of high frequency powers having different frequencies from inside and outside the arrangement circle of the cylindrical substrate are introduced into the reaction vessel. In the case of introduction, it was better to apply high frequency power of a plurality of different frequencies to the high frequency power introduction means inside and outside the arrangement circle of the cylindrical substrate than to apply high frequency power of a single frequency. .
[0101]
<Example 2>
Using the deposited film forming apparatus shown in FIG. 1, on the cylindrical substrate (cylindrical aluminum cylinder 102 having a mirror finish with a diameter of 80 mm and a length of 358 mm) under the conditions shown in Table 4 below, a blocking layer and a photoconductive layer are formed. Film formation was performed in the order of the layer and the surface layer to prepare an electrophotographic photosensitive member. As the high frequency power source, first high frequency power sources 107 and 109 capable of outputting high frequency power having a frequency of 105 MHz and second high frequency power sources 108 and 110 capable of outputting high frequency power having a frequency of 70 MHz were used. Further, the ratio of the high-frequency power value of 105 MHz applied to the first high-frequency power introduction means and the high-frequency power value of 70 MHz is set as the condition shown in Table 5 below, and the frequency applied to the second high-frequency power introduction means is The ratio of the high-frequency power value of 105 MHz and the high-frequency power value of 70 MHz was constant in each layer under the conditions shown in Table 4. In addition, each gas type used at the time of producing the electrophotographic photosensitive member has a constant flow rate in each layer.
[0102]
[Table 4]

[0103]
P1 in Table 4 is the power value of the higher frequency (105 MHz) in the high frequency power applied from the first high frequency introducing means, and P2 is the power value of the lower frequency (70 MHz). In Table 4, P1 ′ is the power value of the higher frequency (105 MHz) in the high-frequency power applied from the second high-frequency introducing means, and P2 ′ is the power value of the lower frequency (70 MHz). . Furthermore, R1 in Table 4 is the ratio of P2 to the total power value applied from the first high-frequency power introduction means, and R2 is the ratio of P2 ′ to the total power value applied from the second high-frequency power introduction means.
[0104]
[Table 5]

[0105]
The number of spherical protrusions, film thickness unevenness, chargeability unevenness and sensitivity unevenness of the electrophotographic photosensitive member produced under the above conditions were determined in the same manner as in Example 1.
[0106]
The number of spherical protrusions, film thickness unevenness, chargeability unevenness, and feeling obtained under the conditions I to VI of Example 2
The degree of unevenness was evaluated relative to each measured value of II as 100. The results are shown in Table 6.
.
[0107]
[Table 6]

[0108]
From Table 6, the ratio of the power value of the high frequency power with the frequency introduced into the reaction vessel from the second high frequency power introducing means in the arrangement circle is 105 MHz and 70 MHz is made constant, and the first high frequency electric energy outside the arrangement circle is obtained. The frequency applied from the first high-frequency power introducing means and the second high-frequency power introducing means when the ratio of the power values of the high-frequency power whose frequencies introduced into the reaction vessel from the introducing means are 105 MHz and 70 MHz is changed. All of the above evaluations were better when the absolute value of the difference between R1 and R2 was between 0.05 and 0.6 than when the ratios R1 and R2 of the high-frequency power with a frequency of 105 MHz and 70 MHz were the same ratio However, when the difference between R1 and R2 was larger than 0.6, it was slightly improved.
[0109]
From this result, the ratio R1 between the power value P1 of the high frequency power having the higher frequency and the power value P2 of the high frequency power having the lower frequency out of the high frequency power taking the upper two power values of the first high frequency power introduction means. Between the high frequency power value P′1 having the higher frequency and the power value P′2 of the high frequency power having the lower frequency among the high frequency powers having the upper two power values of the second high frequency power introduction means R2 was better when R1 ≠ R2 than when R1 = R2. Among them, the condition of 0.05 ≦ | R1-R2 | ≦ 0.6 was even better.
[0110]
<Example 3>
An electrophotographic photoreceptor was produced in the same manner as in Example 2 under the conditions shown in Table 7 below. At this time, as the high frequency power source, the first high frequency power sources 107 and 109 capable of outputting high frequency power having a frequency of 105 MHz and the second high frequency power sources 108 and 110 capable of outputting high frequency power having a frequency of 50 MHz are used. The frequency applied to the first high-frequency power introducing means is a frequency applied to the second high-frequency power introducing means with the ratio of the high-frequency power value having a frequency of 105 MHz and the high-frequency power value having a frequency of 70 MHz being constant in each layer under the conditions shown in Table 7 below. The ratio between the high frequency power value of 105 MHz and the high frequency power value of 70 MHz was set as the condition shown in Table 8 below.
[0111]
[Table 7]

[0112]
[Table 8]

[0113]
P1 in Table 7 is the power value of the higher frequency (105 MHz) in the high frequency power applied from the first high frequency introducing means, and P2 is the power value of the lower frequency (50 MHz). Further, P1 ′ in Table 4 is the power value of the higher frequency (105 MHz) in the high frequency power applied from the second high frequency introducing means, and P2 ′ is the power value of the lower frequency (50 MHz). . Furthermore, R1 in Table 4 is the ratio of P2 to the total power value applied from the first high-frequency power introduction means, and R2 is the ratio of P2 ′ to the total power value applied from the second high-frequency power introduction means.
[0114]
The number of spherical protrusions, film thickness unevenness, chargeability unevenness and sensitivity unevenness of the electrophotographic photosensitive member produced under the above conditions were determined in the same manner as in Example 1.
[0115]
With respect to the number of spherical protrusions, film thickness unevenness, chargeability unevenness, and sensitivity unevenness obtained under the conditions I to VI of Example 3, relative evaluation was performed with each measured value of II being 100. The results are shown in Table 9.
[0116]
[Table 9]

[0117]
From Table 9, the ratio of the power value of the high frequency power with the frequency introduced into the reaction vessel from the first high frequency power introduction means outside the arrangement circle is 105 MHz and 50 MHz is made constant, and the second high frequency electric energy in the arrangement circle is obtained. The frequency applied from the first high-frequency power introducing means and the second high-frequency power introducing means when the ratio of the power values of the high-frequency power with the frequencies introduced from the introducing means into the reaction vessel being 105 MHz and 50 MHz is changed. All of the above evaluations were better when the absolute value of the difference between R1 and R2 was between 0.05 and 0.6 than when the ratios R1 and R2 of the high-frequency power with a frequency of 105 MHz and 50 MHz were the same ratio However, when the difference between R1 and R2 was larger than 0.6, it was slightly improved.
[0118]
From this result, the ratio R1 between the power value P1 of the high frequency power having the higher frequency and the power value P2 of the high frequency power having the lower frequency out of the high frequency power taking the upper two power values of the first high frequency power introduction means. And the ratio R2 of the power value P′1 of the higher frequency power and the power value P2 ′ of the lower frequency of the high frequency power taking the upper two power values of the second high frequency power introduction means However, the condition of R1 ≠ R2 was better than the condition of R1 = R2. Among them, the condition of 0.05 ≦ | R1-R2 | ≦ 0.6 was even better.
[0119]
【The invention's effect】
As described above, according to the present invention, in forming a deposited film by the high-frequency-PCVD method, the uniformity of the deposited film characteristics is high and the number of spherical protrusions is reduced. Therefore, it is possible to form a deposited film that can cope with high image quality required in recent years.
[Brief description of the drawings]
FIG. 1A is a schematic vertical sectional view of a deposited film forming apparatus showing a first embodiment of the present invention. (B) is a horizontal sectional view of (a).
FIG. 2A is a schematic vertical sectional view of a deposited film forming apparatus showing a second embodiment of the present invention. (B) is a horizontal sectional view of (a).
FIG. 3 (a) is a schematic vertical sectional view showing an example of a deposited film forming apparatus by a VHF plasma CVD method using a conventional VHF band frequency. (B) is a horizontal sectional view of (a).
FIG. 4A is a schematic vertical sectional view showing an example of a deposited film forming apparatus using a VHF plasma CVD method using a conventional VHF band frequency. (B) is a horizontal sectional view of (a).
FIG. 5 (a) is a schematic vertical sectional view showing an example of a deposited film forming apparatus by a VHF plasma CVD method using a conventional VHF band frequency. (B) is a horizontal sectional view of (a).
FIG. 6 is a schematic vertical sectional view of a deposited film forming apparatus showing a third embodiment of the present invention.
FIG. 7 (a) is a schematic vertical sectional view showing an example of a deposited film forming apparatus by a VHF plasma CVD method using a conventional VHF band frequency. (B) is a horizontal sectional view of (a).
FIG. 8 is a view showing an example of a layer structure of a light-receiving member for electrophotography that can be formed according to the present invention.
[Explanation of symbols]
101, 201, 301, 401, 501, 601, 701 Reaction vessel
102, 202, 302, 402, 502, 602, 702 Cylindrical substrate
103, 203, 303, 403, 503, 603, 703 First high frequency electrode
104, 204, 604 Second high-frequency electrode
105, 205, 605 First matching box
106, 206, 606 Second matching box
107, 109, 207, 209, 407, 507 First high frequency power supply
108, 110, 208, 210, 308, 508, 708 Second high frequency power supply
111, 211, 311, 411, 511, 611, 711 Heater
112, 212, 312, 412, 512, 612, 712 Source gas introduction means
113, 213, 313, 413, 513, 613, 713
114, 214, 314, 414, 514, 614, 714 Motor
115, 215, 315, 415, 515, 615, 715 Reduction gear
116, 216, 316, 416, 516, 616, 716 Exhaust port
117 cylindrical wall
118 Shield
619 First high frequency oscillator
620 Second high frequency oscillator
621 amplifier
622 amplifier
623 amplifier
624 amplifier
800 Photoconductor for electrophotography
801 Support
802 Photoconductive layer
803 Surface layer
804 Charge injection blocking layer
805 Charge generation layer
806 Charge transport layer

Claims

A plurality of cylindrical substrates are arranged on the same circumference in a depressurizable reaction vessel, and the raw material gas supplied into the reaction vessel is introduced from the first high-frequency power introducing means and the second high-frequency power introducing means. In a deposited film forming method, wherein the deposited film is decomposed by the high frequency power and the deposited film is formed on the cylindrical substrate.
Introducing high frequency power from outside the arrangement circle of the cylindrical substrate by the first high frequency power introducing means;
Introducing high frequency power from within the arrangement circle of the cylindrical substrate by the second high frequency power introducing means;
Independently controlling the high-frequency power applied to the first high-frequency power introducing means and the high-frequency power applied to the second high-frequency power introducing means;
A deposited film forming method, wherein a deposited film is formed by introducing a plurality of high frequency powers having different frequencies into each of the first high frequency power introducing means and the second high frequency power introducing means.

Among the plurality of high frequency powers applied to the first high frequency power introducing means, among the high frequency powers having the upper two power values, the higher power value is P1, the lower power value is P2, and R1 is As (a) below,
Among a plurality of high-frequency powers applied to the second high-frequency power introduction means, among the high-frequency powers having the upper two power values, the higher power value is P1 ′, the lower power value is P2 ′, R2 is the following (b),
The deposited film forming method according to claim 1, wherein the deposited film is formed by introducing high-frequency power that satisfies the following condition (c).
(A) R1 = P2 / (P1 + P2)
(B) R2 = P2 ′ / (P1 ′ + P2 ′)
(C) R1 ≠ R2

When the frequencies of the high-frequency power taking the upper two power values among the plurality of high-frequency power applied to the first high-frequency power introducing means are f1 and f2, the following conditions (d) and (e) are satisfied:
The following conditions (f) and (g) are satisfied, where f1 ′ and f2 ′ are the frequencies of the high-frequency power that takes the upper two power values among the plurality of high-frequency power applied to the second high-frequency power introduction means. 3. The deposited film forming method according to claim 1, wherein the deposited film is formed by introducing high-frequency power.
(D) 10 MHz ≦ f2 <f1 ≦ 250 MHz
(E) 0.1 ≦ R1 ≦ 0.9
(F) 10 MHz ≦ f2 ′ <f1 ′ ≦ 250 MHz
(G) 0.1 ≦ R2 ≦ 0.9

A deposited film is formed on the cylindrical substrate by introducing high-frequency power from the first high-frequency power introducing means arranged at a plurality of intervals on the same concentric circle as the center of the arrangement circle of the cylindrical substrate. The deposited film forming method according to claim 1.

5. The deposited film is formed on the cylindrical substrate by introducing high-frequency power from the second high-frequency power introducing means installed at the center of the arrangement circle of the cylindrical substrate. A method for forming a deposited film.

A deposited film is formed on the cylindrical substrate in a reaction vessel that surrounds a plurality of cylindrical substrates and has a cylindrical wall whose central axis passes through the center of the arrangement circle of the cylindrical substrates. The deposited film forming method according to claim 1.

7. The deposited film forming method according to claim 6, wherein a deposited film is formed on the cylindrical substrate by introducing a high frequency power applied to the first high frequency power introducing means from outside the reaction vessel.

7. The deposited film forming method according to claim 6, wherein a deposited film is formed on the cylindrical substrate by introducing a high-frequency power applied to the first high-frequency power introducing means from the reaction vessel.

The high-frequency power frequency f1 applied to the first high-frequency power introduction means and the high-frequency power frequency f1 ′ applied to the second high-frequency power introduction means satisfy the following condition (h) using the high-frequency power: The deposited film forming method according to claim 3, wherein a deposited film is formed on a cylindrical substrate.
(H) f1 = f1 ′

The high frequency power applied to the first high frequency power introducing means and the high frequency power applied to the second high frequency power introducing means f2 ′ satisfy the following condition (i) using the high frequency power: The deposited film forming method according to claim 3, wherein a deposited film is formed on a cylindrical substrate.
(I) f2 = f2 ′

11. The deposited film forming method according to claim 1, wherein the deposited film formed on the cylindrical substrate is an amorphous material containing silicon atoms.

12. The deposited film forming method according to claim 1, wherein the deposited film forming method is used for manufacturing an electrophotographic photosensitive member.

A plurality of cylindrical substrates are installed in a depressurizable reaction vessel, and the raw material gas supplied into the reaction vessel is decomposed by the high frequency power introduced from the first high frequency power introducing means and the second high frequency power introducing means. In the deposited film forming apparatus for forming a deposited film on the cylindrical substrate,
The cylindrical substrates are arranged at equal intervals on the same circumference,
The first high-frequency power introducing means is disposed outside the arrangement circle of the cylindrical base body,
The second high-frequency power introducing means is disposed within the arrangement circle of the cylindrical substrate,
Control means capable of independently controlling the high frequency power applied to the first high frequency power introduction means and the high frequency power applied to the second high frequency power introduction means;
A deposited film forming apparatus comprising a high frequency power source capable of introducing a plurality of high frequency powers having different frequencies into the first high frequency power introducing unit and the second high frequency power introducing unit.

When the frequencies of the high-frequency power taking the upper two power values among the plurality of high-frequency power applied to the first high-frequency power introducing means are f1 and f2, the following condition (j) is satisfied:
Introducing high-frequency power satisfying the following condition (k), where f1 ′ and f2 ′ are the frequencies of the high-frequency power taking the upper two power values among the plurality of high-frequency power applied to the second high-frequency power introduction means. 14. The deposited film forming apparatus according to claim 13, further comprising a high-frequency power source capable of being used.
(J) 10 MHz ≦ f2 <f1 ≦ 250 MHz
(K) 10 MHz ≦ f2 ′ <f1 ′ ≦ 250 MHz

It is possible to introduce high-frequency power satisfying the following condition (l): the frequency f1 of high-frequency power applied to the first high-frequency power introduction means and the frequency f1 ′ of high-frequency power applied to the second high-frequency power introduction means The deposited film forming apparatus according to claim 13, further comprising a high-frequency power source.
(L) f1 = f1 ′

It is possible to introduce high-frequency power satisfying the following condition (m): the frequency f2 of high-frequency power applied to the first high-frequency power introduction means and the frequency f2 ′ of high-frequency power applied to the second high-frequency power introduction means The deposited film forming apparatus according to claim 13, further comprising a high-frequency power source.
(M) f2 = f2 ′

17. The deposited film forming apparatus according to claim 13, wherein a plurality of the first high-frequency power introducing means are installed at equal intervals on a concentric circle that is the same as the center of the arrangement circle of the cylindrical substrate. .

18. The deposited film forming apparatus according to claim 13, wherein the second high-frequency power introducing means is installed at the center of an arrangement circle of the cylindrical substrate.

The reaction vessel is formed so as to form a cylindrical wall surrounding the cylindrical substrate, and the central axis of the cylindrical wall passes through the center of the arrangement circle of the cylindrical substrate. The deposited film forming apparatus according to 13 to 18.

The deposited film forming apparatus according to claim 19, wherein at least a part of the cylindrical wall is made of a dielectric, and the first high-frequency power introducing means is disposed outside the reaction container.

The deposited film forming apparatus according to claim 19, wherein the cylindrical wall is made of a conductive material, and the first high-frequency power introducing unit is disposed in the reaction vessel.

The deposited film forming apparatus according to claim 13, wherein the deposited film formed on the cylindrical substrate is an amorphous material containing silicon atoms.

The deposited film forming apparatus according to claim 13, wherein the deposited film forming apparatus is used for manufacturing an electrophotographic photosensitive member.