JP2005068454A - Method for forming deposition film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for forming a deposition film, which improves productivity and the uniformity/reproducibility of the characteristics of the deposited film while maintaining adequate film characteristics, in the process of forming the deposition film with the use of a high-frequency power. <P>SOLUTION: In the process for forming the deposition film on a cylindrical substrate by setting a cylindrical substrate in a cylindrical reaction vessel capable of being depressurized, at least one part of which is composed of a dielectric material, supplying a source gas into the cylindrical reaction vessel and decomposing the gas with the high-frequency power introduced from a high-frequency power-introducing means, the method for forming the deposition film comprises arranging the first high-frequency power-introducing means in the cylindrical reaction vessel, and further setting the second high-frequency power-introducing means outside the cylindrical reaction vessel, connecting independent high-frequency sources to each of the first and second high-frequency power-introducing means, and starting the introduction of the high-frequency power into the reaction vessel at different times. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【００７８】
上記条件で作製した電子写真感光体の球状突起数、帯電能ムラ、感度ムラ及び、それぞれのロット内バラツキを下記の条件により測定した。
【００７９】
（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箇所の球状突起数の合計を求めた。同様に６本の電子写真感光体の球状突起数を測定し、６本の平均を球状突起数とした。従って、球状突起数が少ないほど良好であることを示す。
【００８０】
更に６本間の０ｍｍ位置での球状突起数を比較し最小値と最大値の差を球状突起のロット内バラツキとした。
【００８１】
（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Ｍｏｄｅｌ ３４４）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、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。
【００８２】
更に６本間の０ｍｍ位置での帯電能を比較し最小値と最大値の差を帯電能のロット内バラツキとした。
【００８３】
（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感度ムラとした。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。
【００８４】
更に６本間の０ｍｍ位置での感度を比較し最小値と最大値の差を感度のロット内バラツキとした。
【００８５】
（比較例１）
図３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、６本の電子写真感光体を同時に作成した。このとき、第１の高周波電源１０９より周波数が１０５ＭＨｚの高周波電力を、マッチングボックス１０６を介して第１の高周波電力導入手段１０４に、また第２の高周波電源１０７より周波数が１０５ＭＨｚの高周波電力をマッチングボックス１０５を介して第２の高周波電力導入手段１０３に同時に印加し高周波電力を反応容器１１７内に供給すること以外は実施例１と同様の方法で行った。
【００８６】
上記条件により作製した電子写真感光体の球状突起数、帯電能ムラ、感度ムラ及び、それぞれのロット内バラツキを実施例１と同様に求め、その結果を表２及び表３に示す。
【００８７】
【表２】

【００８８】
【表３】

【００８９】
表２及び表３より、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に対する高周波電力の印加開始時間に時間差を設けることにより球状突起数、帯電能ムラ、感度ムラ、ロット内バラツキが改善されることが判明した。
【００９０】
（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、６本の電子写真感光体を同時に作成した。このとき、第１の高周波電源１０９より周波数が１０５ＭＨｚの高周波電力を、また１１０からは周波数が６０ＭＨｚの高周波電力をマッチングボックス１０６を介して第１の高周波電力導入手段１０４に印加することにより反応容器１１７内にプラズマを一旦、形成された後に第２の高周波電源１０７より周波数が１０５ＭＨｚの高周波電力を、また１０８からは周波数が６０ＭＨｚの高周波電力をマッチングボックス１０５を介して第２の高周波電力導入手段１０３に印加し高周波電力を反応容器１１７内に供給した。またプラズマ形成の判断は反応容器の内部圧力の変動により判断し内圧が安定した段階で第２の高周波電力導入手段１０３に高周波電力を印加した。
【００９１】
また、反応容器１１７は円筒状のアルミナセラミック材で構成され内面をブラスト加工を施した。更に高周波電力導入手段１０４及び１０３は直径２０ｍｍの円柱状とし、特に第１の高周波電力導入手段１０４の表面にはアルミナ材溶射を施した。
【００９２】
【表４】

【００９３】
上記条件で作製した電子写真感光体の球状突起数、帯電能ムラ、感度ムラ及び、それぞれのロット内バラツキを実施例１と同様の方法で測定した。
【００９４】
（比較例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、６本の電子写真感光体を同時に作成した。このとき、第１の高周波電力導入手段１０４及び第２の高周波電力導入手段１０３に高周波電力を同時に印加し反応容器１１７内にプラズマを形成したこと以外は実施例２と同様の方法とした。
【００９５】
上記条件により作製した電子写真感光体の球状突起数、帯電能ムラ、感度ムラ及び、それぞれのロット内バラツキを実施例１と同様に求め、その結果を表５及び表６に示す。
【００９６】
（実施例３）
実施例２と同様に図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、６本の電子写真感光体を同時に作成した。このとき、第２の高周波電源１０７より周波数が１０５ＭＨｚの高周波電力を、また１０８からは周波数が６０ＭＨｚの高周波電力をマッチングボックス１０５を介して第２の高周波電力導入手段１０３に印加することにより反応容器１１７内にプラズマを一旦、形成された後に第１の高周波電源１０９より周波数が１０５ＭＨｚの高周波電力を、また１１０からは周波数が６０ＭＨｚの高周波電力をマッチングボックス１０６を介して第１の高周波電力導入手段１０４に印加し高周波電力を反応容器１１７内に供給した。またプラズマ形成の判断は反応容器の内部圧力の変動により判断し内圧が安定した段階で第１の高周波電力導入手段１０４に高周波電力を印加した。
【００９７】
また、反応容器１１７は円筒状のアルミナセラミック材で構成され内面をブラスト加工を施した。更に高周波電力導入手段１０４及び１０３は直径２０ｍｍの円柱状とし、特に第１の高周波電力導入手段１０４の表面にはアルミナ材溶射を施した。
【００９８】
実施例２、実施例３及び比較例２によって得られた球状突起数、帯電能ムラ、感度ムラ及びそれぞれのロット内バラツキについて、比較例２の各測定値を１００として相対評価を行った。この結果を表５及び表６に示す。
【００９９】
【表５】

【０１００】
【表６】

【０１０１】
表５及び表６より、第１の高周波電力導入手段、第２の高周波電力導入手段それぞれに対し周波数の異なる複数の高周波電力が印加可能な構成で更に反応容器内に第１の高周波電力導入手段、反応容器外に第２の高周波電力導入手段を設け、更に第１の高周波電力導入手段と第２の高周波電力導入手段に対する高周波電力の印加開始時間に時間差を設けることにより球状突起数、帯電能ムラ、感度ムラ、ロット内バラツキが改善されることが判明した。
【０１０２】
また反応容器内の第１の高周波電力導入手段、次いで反応容器外の第２の高周波電力導入手段の順に周波数の異なる高周波電力を印加することが更に効果的であることが判明した。
【０１０３】
（実施例４）
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１０２）上に表７に示す条件で、阻止層、光導電層、表面層の順に成膜を行い、１０ロット計１０本の電子写真感光体を作成した。
【０１０４】
このとき、第１の高周波電源２０９より周波数が１０５ＭＨｚの高周波電力を、また２１０からは周波数が６０ＭＨｚの高周波電力をマッチングボックス２０６を介して第１の高周波電力導入手段２０４に印加することにより反応容器２１７内にプラズマを一旦、形成された後に第２の高周波電源２０７より周波数が１０５ＭＨｚの高周波電力を、また２０８からは周波数が６０ＭＨｚの高周波電力をマッチングボックス２０５を介して第２の高周波電力導入手段２０３に印加し高周波電力を反応容器２１７内に供給した。
【０１０５】
またプラズマ形成の判断は反応容器の内部圧力の変動により判断し内圧が安定した段階で第２の高周波電力導入手段２０３に高周波電力を印加した。
【０１０６】
また、反応容器２１７は円筒状のアルミナセラミック材で構成され内面をブラスト加工を施した。更に高周波電力導入手段２０４及び２０３は直径２０ｍｍの円柱状とし、特に第１の高周波電力導入手段２０４の表面にはアルミナ材溶射を施した。
【０１０７】
【表７】

【０１０８】
上記条件で作製した電子写真感光体の球状突起数、帯電能及び、感度それぞれのロットバラツキを下記の条件により測定した。
【０１０９】
（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箇所の球状突起数の合計を求め球状突起数とした。従って、球状突起数が少ないほど良好であることを示す。
【０１１０】
更に１０本間の球状突起数を比較し最小値と最大値の差を球状突起のロットバラツキとした。
【０１１１】
（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Ｍｏｄｅｌ ３４４）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、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、平均を帯電能とした。従って、帯電能ムラが小さいほど良好であることを示す。
【０１１２】
更に１０本間の帯電能を比較し最小値と最大値の差を帯電能のロットバラツキとした。
【０１１３】
（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、平均を感度とした。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。
【０１１４】
更に１０本間の感度を比較し最小値と最大値の差を感度のロットバラツキとした。
【０１１５】
（比較例３）
実施例４と同様に図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１０２）上に表７に示す条件で、阻止層、光導電層、表面層の順に成膜を行い、１０ロット計１０本の電子写真感光体を作成した後、実施例４で同様の方法で球状突起数、帯電能、感度の評価を行った。
【０１１６】
但し、第１の高周波電力導入手段２０４及び第２の高周波電力導入手段２０３に対し高周波電力の印加開始時間に時差を設けず同時に印加した。
【０１１７】
実施例４及び比較例３によって得られた球状突起数、帯電能、感度それぞれのロットバラツキについて、比較例３の各測定値を１００として相対評価を行った。この結果を表８に示す。
【０１１８】
【表８】

【０１１９】
表８より、第１の高周波電力導入手段、第２の高周波電力導入手段それぞれに対し周波数の異なる複数の高周波電力が印加可能な構成で更に反応容器内に第１の高周波電力導入手段、反応容器外に第２の高周波電力導入手段を設け、更に第１の高周波電力導入手段と第２の高周波電力導入手段に対する高周波電力の印加開始時間に時間差を設けることにより球状突起数、帯電能、感度のロットバラツキが改善されることが判明した。
【０１２０】
【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、画像欠陥が低減し、基体間・ロット間での特性ばらつきが抑制され、均一性・再現性が高く、安定した堆積膜形成が可能となる。また、堆積膜形成時間の短縮、原料ガス利用効率の向上が達成され、生産コストの低下が実現可能となる。
【０１２１】
この結果、特性の優れた半導体デバイス、電子写真用光受容部材等を低コストで安定して生産することが可能となる。
【図面の簡単な説明】
【図１】本発明に用いることができる堆積膜形成装置の一例を示した模式的な構成図である。
【図２】本発明に用いることができる堆積膜形成装置の一例を示した模式的な構成図である。
【図３】本発明に用いることができる堆積膜形成装置の一例を示した模式的な構成図である。
【図４】従来のＶＨＦ帯の周波数を用いたＶＨＦプラズマＣＶＤ法堆積膜形成装置の一例を示した模式的な構成図である。
【図５】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例を示した図である。
【符号の説明】
１０１、２０１・・・反応容器の蓋
１０２、２０２、４０２・・・円筒状基体
１０３、２０３・・・第２高周波電力導入手段
１０４、２０４・・・・・・第２高周波電力導入手段
１０５、２０５・・・・・・第２のマッチングボックス
１０６、２０６・・・・・・第１のマッチングボックス
１０７、１０８、２０７、２０８・・・第２の高周波電源
１０９、１１０、２０９、２１０・・・第１の高周波電源
１１１、３１１、４１１・・・ヒーター
１１２、２１２、４１２・・原料ガス供給手段
１１３、２１３、４１３・・回転軸
１１４、２１４、４１４・・モータ
１１５、２１５、４１５・・減速ギア
１１６、２１６、４１６・・排気口
１１７、２１７、４０１・・反応容器
１１８、２１８・・・導電性シールド
４０５・・マッチングボックス
４０９・・・高周波電源
５００・・・電子写真用感光体
５０１・・・導電性基体
５０２・・・光導電層
５０３・・・表面層
５０４・・・電荷注入阻止層
５０５・・・電荷発生層
５０６・・・電荷輸送層[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for forming a deposited film on a substrate, especially a functional film, particularly a deposited film used for a semiconductor device, an electrophotographic photoreceptor, an image input line sensor, a photographing device, a photovoltaic device and the like.
[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. 3 shows a schematic configuration diagram showing an example of an electrophotographic photoreceptor forming apparatus. 4A is a schematic view showing a longitudinal section of a conventional electrophotographic photoreceptor forming apparatus, and FIG. 4B is a cross-sectional view of the electrophotographic photoreceptor forming apparatus shown in FIG. 4A. It is a schematic diagram which shows. An exhaust port 416 is formed on the bottom surface of the reaction vessel 401, and an exhaust unit (not shown) is connected to the other end of the exhaust port 416. The cylindrical substrate 402 is disposed so as to surround the central portion of the reaction vessel 401, and is configured to be held by a rotating shaft 413 and heated by a heater 411. By driving the motor 414, the rotating shaft 413 is rotated via the reduction gear 415, and the cylindrical base body 402 is rotated.
[0005]
The source gas is introduced into the reaction vessel 401 through a source gas introduction pipe 412 from a source gas supply means (not shown). High-frequency power in the VHF band is introduced from the cathode electrode 404 into the reaction vessel 401 via the high-frequency matching box 406 from the high-frequency power source 409. At this time, since the cylindrical base body 402 is maintained at the ground potential via the rotating shaft 413, it functions 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 402 is installed in the reaction vessel 401, and the inside of the reaction vessel is exhausted through an exhaust port 416 by an exhaust device (not shown). Subsequently, the heater 411 controls the temperature of the cylindrical base body 402 to a predetermined temperature of 20 ° C. to 450 ° C.
[0007]
When the cylindrical substrate 402 reaches a predetermined temperature, the source gas is introduced into the reaction vessel 401 from the source gas supply means via the source gas introduction pipe 412. When the source gas reaches a predetermined flow rate and the pressure in the reaction vessel 401 is stabilized, high-frequency power in the VHF band is introduced from the cathode electrode 404 into the reaction vessel 401 via the high-frequency matching box 406 from the high-frequency power source 409. As a result, glow discharge occurs, and the source gas is excited and dissociated to form a deposited film on the cylindrical substrate 402. After the desired film thickness is formed, the supply of high-frequency power is stopped, the gas flow into the reaction vessel 401 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. During the formation of the deposited film, the cylindrical substrate 402 is rotated at a predetermined speed by the motor 414 via the rotating shaft 413, so that the deposited film is formed on the entire surface of the cylindrical substrate 402.
[0008]
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.
[0009]
For example, a plurality of cylindrical substrates are arranged at equal intervals on the same circumference inside a shielding plate partially made of a dielectric, and electrodes are arranged on the inside and outside of the shielding plate to deposit a film on the cylindrical substrate. The technology of the deposited film forming method and apparatus for forming the film is disclosed (see Patent Document 1). It has been shown that an image defect reduction effect can be obtained by forming a deposited film on a cylindrical substrate using this deposited film forming method and apparatus.
[0010]
Further, a plurality of cylindrical substrates are arranged on the same circumference at equal intervals in a reaction vessel made of a non-conductive material, and cathode electrodes are arranged inside and outside the reaction vessel to deposit a deposited film on the cylindrical substrate. The technique of the deposited film formation method and apparatus to form is disclosed (refer patent document 2). 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.
[0011]
[Patent Document 1]
JP-A-11-026388
[Patent Document 2]
Japanese Patent Application Laid-Open No. 11-092932
[0012]
[Problems to be solved by the invention]
A good deposited film is formed by the conventional method and apparatus. However, the level of market demand for products using these deposited films is increasing day by day, and higher quality deposited films are required to meet this demand.
[0013]
For example, in the case of an electrophotographic photoreceptor, there are very high demands for improving the process speed of the electrophotographic apparatus, reducing the size of the apparatus, and reducing the price, and the characteristics of the photoreceptor that can realize these, specifically charging ability, sensitivity, etc. It is indispensable to improve the production cost, reduce production costs, and improve the yield rate during production.
[0014]
In recent years, digital electrophotographic devices and color electrophotographic devices, which have been widely used, often make copies of not only text originals but also photographs, pictures, design drawings, etc., so that image density unevenness can be reduced more than before. Is now required. At the same time, structural defects such as spherical protrusions that cause image defects such as white spots or black spots on the image are required to be reduced more than ever.
[0015]
Such structural defects include those grown from foreign substances such as dust adhering to the object to be processed before the formation of the deposited film, as well as the deposited film formed in the apparatus during the formation of the deposited film inside the film. There is a thin film peeled off due to the stress, diffused as a film piece in the discharge space, and a part of which has grown on the substrate. For this reason, the substrate before film formation is strictly cleaned, and transported into the reaction vessel in a dust-controlled environment such as a clean room, so as to prevent dust from adhering to the substrate as much as possible. In addition, in order to prevent the deposited film formed in the reaction vessel from peeling off, the surface of the reaction vessel inner wall or the surface of the components in the reaction vessel is roughened, or a ceramic having a large surface energy. It has been treated with a material. In addition, with the aim of reducing the internal stress in the film as much as possible, optimization of the deposited film formation conditions and the deposited film stack structure has been made. However, as described above, the demand for the image level from the market is very high, and the permissible level of such structural defects (the number of structural defects and the size of the structural defects) is becoming stricter. Under these circumstances, aiming for further improvement of the structural defect suppression technology, there is a strong demand for improvement so that the formed deposited film is not peeled off.
[0016]
There is also room for improvement in terms of the uniformity and reproducibility of the characteristics of the deposited film formed. If the uniformity and reproducibility of the deposited film characteristics are insufficient, it will lead to variations in the deposited film characteristics, a decrease in product quality, and a decrease in the yield rate. In particular, in the case of forming a member consisting of a stacked structure of a plurality of deposited films, if the film characteristics of a certain layer deteriorate due to this characteristic variation, matching with other layers also deteriorates and the entire member is greatly affected. turn into. Further, in a member having a large area such as an electrophotographic photosensitive member, even if the film quality is locally deteriorated, only the portion cannot be removed, so that the influence is great. Thus, improving the uniformity and reproducibility of the deposited film characteristics and suppressing the variation in the deposited film characteristics greatly contributes to improving the characteristics of the deposited film as a whole and lowering the cost of forming the deposited film.
[0017]
In this way, realizing a deposited film formation method that can reduce spherical protrusions that cause image defects and improve the uniformity and reproducibility of deposited film properties can improve product quality and reduce production costs. It is indispensable for meeting the current market demands.
[0018]
OBJECT OF THE INVENTION
The present invention aims to solve the above problems. That is, in the present invention, a cylindrical substrate is installed in a reaction vessel that can be depressurized, and the raw material gas supplied into the reaction vessel is decomposed by the high-frequency power introduced from the high-frequency power introducing means, and deposited on the cylindrical substrate. In deposition film formation by high frequency-PCVD method to form a film, while maintaining good film characteristics, it achieves reduction of spherical projections that cause image defects such as white spots or black spots on the image, and uniform deposition film characteristics It is an object of the present invention to provide a deposited film forming method capable of improving the property and reproducibility.
[0019]
[Means and Actions for Solving the Problems]
As a result of intensive studies to achieve the above object, the present inventors have found that, in the deposited film forming method, the method of introducing high-frequency power is effective for deposited film characteristics, uniformity / reproducibility of deposited film characteristics, and productivity of deposited films. I found that it had a big influence.
[0020]
That is, in the present invention, a cylindrical substrate is placed in a depressurizable cylindrical reaction vessel at least partially made of a dielectric material, and the source gas supplied into the cylindrical reaction vessel is introduced from the high-frequency power introducing means. In the deposited film forming method in which the deposited high-frequency power is decomposed to form a deposited film on the cylindrical substrate, first cylindrical high-frequency power introducing means is provided inside the cylindrical reaction vessel, and the cylindrical reaction is further performed. A second high-frequency power introduction means is set outside the container, and independent high-frequency power sources are connected to the first high-frequency power introduction means and the second high-frequency power introduction means so that a time difference is provided in the introduction start time of the high-frequency power. The present invention relates to a method for forming a deposited film.
[0021]
Further, in the present invention, it is desirable that the high frequency power is introduced into the second high frequency power introduction means after the high frequency power is introduced into the first high frequency power introduction means.
[0022]
Further, in the present invention, it is desirable that high frequency power is introduced into the first high frequency power introduction means, and the high frequency power is introduced into the second high frequency power introduction means after the plasma is formed in the cylindrical reaction vessel.
[0023]
Furthermore, the present invention introduces a plurality of high frequency powers having different frequencies into each of the first high frequency power supply means and the second high frequency power supply means, and the plurality of high frequency powers to be introduced into the first high frequency power supply means. The frequency of one high-frequency power of the top two power values at f1 is f1, the power value is P1, the frequency of the other high-frequency power is f2, and the power value is P2. When the frequency of one high frequency power among the top two power values of the high frequency power is f1 ′, the power value is P1 ′, the frequency of the other high frequency power is f2 ′, and the power value is P2 ′, the following formula ( It is desirable to satisfy A) to (D).
[0024]
10 MHz ≦ f2 <f1 ≦ 250 MHz (A)
0.1 ≦ P2 / (P1 + P2) ≦ 0.9 (B)
10 MHz ≦ f2 ′ <f1 ′ ≦ 250 MHz (C)
0.1 ≦ P2 ′ / (P1 ′ + P2 ′) ≦ 0.9 (D)
Further, in the present invention, it is desirable that the deposited film is an electrophotographic photoreceptor composed of a non-single crystal material having at least silicon atoms as a base.
[0025]
According to the present invention as described above, it is possible to form a deposited film having good characteristics uniformly and with good reproducibility on a single substrate or a plurality of substrates, and to further suppress the occurrence of spherical protrusions. It is.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic vertical cross-sectional view showing an example of an a-Si photoconductor deposited film manufacturing apparatus that can be used in the present invention. 1A is a schematic vertical sectional view, and FIG. 1B is a schematic horizontal sectional view of FIG.
[0027]
An exhaust port 116 is formed on the bottom surface of the reaction vessel 117, and the other end of the exhaust pipe is connected to an exhaust device (not shown). Cylindrical substrates 102 on which the deposited film is formed are arranged in parallel to each other at equal intervals on the same circumference, and at least a part of the cylindrical reaction vessel is made of a dielectric material so as to surround the cylindrical substrate 102. 117 (hereinafter referred to as reaction vessel) is arranged. The cylindrical base 102 is held by a rotating shaft 113, and when the motor 114 is driven, the rotating shaft 113 rotates via the reduction gear 115, and the cylindrical base 102 rotates. The cylindrical substrate 102 can be heated by a heating element 111.
[0028]
The first 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 first high-frequency power sources 109 and 110 is the first Through the matching box 106, the first high frequency power introducing means 104 supplies the film into the reaction vessel 117 serving as a film formation space.
[0029]
In addition, the second high frequency power introduction means 103 is installed on the same circumference at equal intervals outside the reaction vessel 117, and the high frequency power output from the second high frequency power sources 107 and 108 is the second matching. Through the box 105, the second high frequency power introducing means 103 supplies the reaction vessel 117 as a film forming space.
[0030]
A source gas introduction unit 112 is installed in the reaction vessel 117, 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 117 via the source gas introduction means.
[0031]
Formation of a deposited film using such an apparatus is performed, for example, as follows.
[0032]
First, the cylindrical substrate 102 is installed in the reaction vessel 117, and the inside of the reaction vessel 101 is exhausted through the 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.
[0033]
When the cylindrical substrate 102 reaches a predetermined temperature, the source gas is introduced into the reaction vessel 117 via the source gas supply means 112. After confirming that the flow rate of the source gas becomes the set flow rate and that the pressure in the reaction vessel 117 is stable, the first cathode electrode 104 is passed from the first high-frequency power sources 109 and 110 through the first matching box 106. A predetermined high-frequency power is supplied to Similarly, predetermined high frequency power is supplied from the second high frequency power supplies 107 and 108 to the second cathode electrode 103 via the second matching box 105. At this time, two independent high-frequency power controls are required. This high-frequency power introduction procedure is performed by setting the power applied from the first high-frequency power introduction means 104 to a predetermined value and then the second high-frequency power introduction procedure. It is desirable to set the power applied from the power introduction means 103 to a predetermined value. Glow discharge occurs in the reaction vessel 117 by the high frequency power introduced into the reaction vessel 117 by the above method, and the source gas is excited and dissociated to form a deposited film on the cylindrical substrate 102.
[0034]
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. However, the discharge start operation described above may be performed when the discharge is once stopped and the discharge is started again when the layers are stacked.
[0035]
Further, 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.
[0036]
In the present invention, a plurality of high-frequency power having different frequencies is applied by high-frequency power introducing means installed inside and outside the cylindrical reaction vessel, and by independently controlling the high-frequency application start time to each high-frequency introducing means, Uniform plasma having a sufficient density can be generated in the entire reaction vessel.
[0037]
In the present invention, the high frequency power applied to the first high frequency power introduction means 104 installed in the arrangement circle of the cylindrical substrate 102 and the second high frequency power introduction means 103 installed outside the arrangement circle of the cylindrical reaction vessel 117. By providing a time difference in the power application start time, the plasma state in the discharge space within the cylindrical reaction vessel 117 can be made uniform.
[0038]
This is because when high-frequency power is simultaneously applied to the first high-frequency power introduction means 104 and the second high-frequency power introduction means 103, the vicinity of the inner wall of the reaction vessel 117 or the vicinity of the cylindrical substrate 102 in the initial stage of plasma formation. Plasma localization may occur in the discharge space in which plasma is formed within the arrangement circle of the cylindrical substrate 102 installed on the circumference or on the same circumference. There may be some variation between the two. Furthermore, once the plasma is localized in the initial stage of plasma formation, it is difficult to uniformly control the plasma in the discharge space. When the deposited film is formed while the plasma is localized, the film thickness unevenness of the deposited film or the stress balance of the film may be impaired, and film peeling may occur. This is because power absorption is large in the vicinity of the high-frequency power introduction means, and power unevenness occurs as the distance from the first and second power introduction means increases in the cross-sectional direction of the reaction vessel, and the first and second power introduction means simultaneously. It is considered that when high frequency power is applied, the power balance in the discharge space becomes unstable and the plasma is localized.
[0039]
In the present invention, it is desirable to apply the high frequency power to the second high frequency power introducing means after supplying the high frequency power to the first high frequency power introducing means provided in the discharge space. This is because when high-frequency power is first applied to the first high-frequency power introducing means provided in the discharge space, plasma is further increased than when high-frequency power is first supplied from the second high-frequency power introducing means provided outside the reaction vessel. This is because the formation of the plasma is stable and the plasma spreads uniformly in the discharge space with a relatively low power.
[0040]
Further, in the present invention, by applying high-frequency power to the first high-frequency power introducing means by applying high-frequency power to the second high-frequency power introducing means after plasma is formed in the discharge space in the reaction vessel. Power is efficiently supplied into the discharge space while maintaining a uniform plasma, which is effective.
[0041]
In the present invention, high-frequency power is applied to either the first high-frequency power introduction means or the second high-frequency power introduction means, and after the plasma is formed, high-frequency power is applied to the remaining one high-frequency power introduction means. However, regarding the determination of plasma formation, there is generally a means for monitoring the internal pressure (internal pressure) in the reaction vessel and detecting the formation of plasma by the change in internal pressure due to decomposition of the raw material gas. Detection means may be provided to detect the formation of plasma by temperature change. Further, a window may be provided in the reaction vessel to confirm the formation of plasma directly.
[0042]
In the present invention, a more remarkable effect can be obtained by the following method.
[0043]
A plurality of high-frequency powers having different frequencies as shown in FIG. 1 are applied from the first and second high-frequency power introduction means by applying them by the first high-frequency power introduction means 104 and the second high-frequency power introduction means 103. Since the standing wave generated by the high frequency power can be suppressed and the plasma distribution in the vertical direction of the reaction vessel can be made more uniform, the film characteristics and uniformity in the longitudinal direction of the cylindrical substrate are improved, and the concentration of protrusions is reduced. To do.
[0044]
It is necessary to supply a plurality of high-frequency powers into the reaction vessel from the same electrode. When high-frequency power having different frequencies is supplied from different electrodes, a standing wave depending on the frequency of the high-frequency power is generated for each electrode. As a result, the plasma characteristics in the vicinity of the electrode have a distribution shape corresponding to the standing wave, and the type / ratio of the generated active species and the energy of ions vary depending on the position.
[0045]
In the present invention, the relationship between the plurality of high frequency powers supplied to the electrodes, that is, the frequency and the power ratio may be determined while actually confirming the uniformity of the vacuum processing characteristics. If it is small, it becomes substantially the same as when high-frequency power of the same frequency is applied, and since the node position and antinode position of each standing wave are close, a sufficient standing wave suppressing effect cannot be obtained. If the difference is too large, the wavelength of the high-frequency electric field standing wave of the high-frequency power having the smaller frequency is too large for the wavelength of the high-frequency electric field standing wave of the high-frequency power having the larger frequency. Further, a sufficient standing wave suppressing effect cannot be obtained.
[0046]
In the present invention, it is necessary for obtaining the effect of the present invention that the plurality of high-frequency wave powers supplied to the electrodes include at least two high-frequency powers having a frequency of 10 MHz to 250 MHz.
[0047]
When the frequency is lower than 10 MHz, it is difficult to obtain a high processing speed. More preferably, it is 30 MHz or more from the viewpoint of the deposition rate.
[0048]
On the other hand, if the frequency is higher than 250 MHz, the attenuation of the high-frequency power in the traveling direction becomes remarkable, and the deviation of the attenuation rate from the high-frequency power having a different frequency becomes remarkable, so that a sufficient uniformizing effect cannot be obtained. End up. Therefore, it is preferable to set the frequency to 250 MHz or less because the superposition effect can be effectively obtained.
[0049]
Further, regarding the power ratio of the high-frequency power supplied to the electrodes, when supplying two high-frequency powers of the above frequency, P1 is the first high-frequency power and P2 is the second high-frequency power having a frequency lower than this. The ratio of the second high-frequency power P2 to the total power (P1 + P2) is preferably in the range of 0.1 to 0.9 in order to obtain the effects of the present invention.
[0050]
When the second high-frequency power is smaller than this range with respect to the total power, the high-frequency electric field is dominated by the component due to the first high-frequency power, and the standing wave suppressing effect is not observed. On the other hand, as the second high-frequency power is increased, the influence of the second high-frequency power on the raw material gas decomposition in the reaction vessel is increased, becoming closer to the case where the second high-frequency power is used alone. The suppression effect is reduced. Therefore, at least one of the high-frequency powers is required to be 10% or more with respect to the two total powers in order to obtain the standing wave suppressing effect with certainty.
[0051]
As described above, when the two high-frequency powers are combined, the effect of the present invention can be sufficiently obtained, but it is also possible to combine the third high-frequency power. The range of the third high-frequency power is not particularly limited as long as the first and second high-frequency powers are set in appropriate ranges, but can be as follows.
[0052]
When the third high-frequency power (frequency f3, power P3) is in the range of 10 MHz to 250 MHz similarly to f1 and f2, the first high-frequency power (P1, f1) and the second high-frequency power (P2) , F2) can be expected to have the same mechanism. At this time, if the top two power values of P1 to P3 are redefined as P1 and P2, P3 has the lowest power value. In this case, matching mismatch due to P3 hardly occurs, and the standing wave suppression effect due to P3 is added, so that unevenness may be further suppressed than when P1 and P2 are combined.
[0053]
In the present invention, a single cylindrical substrate may be used, but a plurality of cylindrical substrates may be installed in terms of productivity. However, in the case of installing a plurality of cylindrical substrates, the reaction vessel is cylindrical, and each high-frequency power introduction means, gas supply pipe, and each cylindrical substrate has the same central axis as the reaction vessel. A more remarkable effect can be obtained by arranging them at equal intervals on the circumference. This is presumed to be because processing uniformity for each substrate is improved by making the positional relationship of the cylindrical substrate, the reaction vessel, and the high-frequency power introducing means as symmetrical as possible.
[0054]
Furthermore, the constitution of the present invention is more effective in the case of an electrophotographic photosensitive member and its production. The electrophotographic photosensitive member needs to form a deposited film on a large-area substrate, and further, there must be no structural defect over the entire region. Therefore, according to the present invention, it is possible to obtain a deposited film having a uniform film thickness and film quality on the substrate and having good characteristics. Therefore, the present invention is extremely effective in improving the electrophotographic characteristics and reducing the cost accompanying the improvement in productivity. is there.
[0055]
Further, the shape of the first high-frequency power introducing means 104 and the second high-frequency power introducing means 103 is not particularly limited, but the film peeling from the first high-frequency power introducing means 104 and the second high-frequency power introducing means 103 is not limited. From the viewpoint of preventing this, it is preferable that the curved surface is formed as much as possible, and a cylindrical shape is particularly preferable.
[0056]
Further, the surface of the first high-frequency power introducing means 104 is desirably roughened for the purpose of improving film adhesion, preventing film peeling, and suppressing dust during film formation.
[0057]
Furthermore, from the viewpoint of improving the adhesion of the film, it is effective that the surface of the first high-frequency power introducing means 104 is covered with a ceramic material. The specific means for covering is not particularly limited, but for example, the first high-frequency power introducing means 104 may be mounted so as to cover 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 surface of the first high-frequency power introducing means 104 may be coated with the above material 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 covering the surface of the first high-frequency power introducing means 104 is not particularly limited, but is preferably 1 μm to 10 mm from the viewpoint of increasing the durability and uniformity, and the amount of high-frequency power absorption and manufacturing cost. 10 μm to 5 mm is more preferable.
[0058]
Further, regarding the shape of the reaction vessel 117, it is preferable that a wall surface is provided so that the film formation space where the source gas is decomposed is limited to a cylindrical region. In order to prevent the film from peeling off, it is effective to perform roughening, coating with ceramics, heating and cooling in the same manner as the surface of the first high-frequency power introducing means 104 in order to prevent film peeling. .
[0059]
Further, in FIG. 1, 117 is a cylindrical reaction vessel, and at least a part thereof is made of a dielectric material. Specific examples of the dielectric 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.
[0060]
In addition, providing the cylindrical conductive shield 118 maintained at a constant potential so as to surround the second high-frequency power introducing means 103 installed outside the cylindrical reaction vessel 117 makes it possible to make the emitted high-frequency power uniform. It is suitable for improving
Further, the number and installation positions of the source gas supply means 112 are not particularly limited, but it is effective to install them so that the source gas can be supplied uniformly into the reaction vessel.
[0061]
FIG. 2 is a schematic vertical cross-sectional view showing an example of an a-Si-based photoreceptor deposited film manufacturing apparatus that can be used in the present invention. 2A is a schematic vertical sectional view, and FIG. 2B is a schematic horizontal sectional view of FIG.
[0062]
An exhaust port 216 is formed in the bottom surface of the reaction vessel 217, and the other end of the exhaust pipe is connected to an exhaust device (not shown). One cylindrical substrate 202 on which the deposited film is formed is arranged at the center of a cylindrical reaction vessel (hereinafter referred to as reaction vessel) 217 at least partially made of a dielectric material. The cylindrical base body 202 is held by a rotating shaft 213. When the motor 214 is driven, the rotating shaft 213 rotates via the reduction gear 215, and the cylindrical base body 202 rotates. Further, the cylindrical base body 202 can be heated by a heating element (not shown) provided inside the cylindrical base body 202.
[0063]
First high frequency power introduction means 204 arranged at equal intervals on the same circumference so as to surround the cylindrical base body 202 are installed, and the high frequency power output from the first high frequency power supplies 209 and 210 is the first high frequency power. Via the matching box 206, the first high-frequency power introducing means 204 supplies the film into the reaction vessel 217 serving as a film formation space.
[0064]
In addition, second high-frequency power introduction means 203 are installed on the same circumference at equal intervals outside the reaction vessel 217, and the high-frequency power output from the second high-frequency power sources 207 and 208 is the second matching. Via the box 205, the second high-frequency power introduction means 203 supplies the reaction vessel 217 as a film formation space.
[0065]
A source gas introduction unit 212 is installed in the reaction vessel 217, 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 217 via the source gas introduction means.
[0066]
Formation of a deposited film using such an apparatus can be performed by an operation similar to the method described in the apparatus of FIG.
[0067]
FIG. 3 is a schematic vertical cross-sectional view showing an example of an a-Si photoconductor deposited film manufacturing apparatus that can be used in the present invention. 3A is a schematic vertical sectional view, and FIG. 3B is a schematic horizontal sectional view of FIG.
[0068]
The apparatus of FIG. 3 is the same as the apparatus of FIG. 1 except that there is a single high-frequency power source for applying high-frequency power to each of the first high-frequency power introducing means 104 and the second high-frequency power introducing means 103. is there. However, the high frequency power supplies 107 and 109 use the same frequency. The same parts as those in the apparatus shown in FIG.
[0069]
By using the present invention as described above, for example, an a-Si electrophotographic photoconductor as shown in FIG. 5 can be formed.
[0070]
The electrophotographic photoreceptor 500 shown in FIG. 5A is expressed as amorphous silicon (hereinafter “a-Si: H, X”) containing a hydrogen atom or a halogen atom as a constituent element on a conductive substrate 501. And a photoconductive layer 502 having photoconductivity.
[0071]
An electrophotographic photoreceptor 500 shown in FIG. 5B includes a photoconductive layer 502 made of a-Si: H, X and having photoconductivity on an electroconductive substrate 501, and an amorphous silicon (or amorphous carbon). System) is provided with a surface layer 503.
[0072]
An electrophotographic photoreceptor 500 shown in FIG. 5C has an amorphous silicon-based charge injection blocking layer 504 and a photoconductive layer made of a-Si: H, X and having photoconductivity on a conductive substrate 501. 502 and an amorphous silicon-based (or amorphous carbon-based) surface layer 503 are provided.
[0073]
In the electrophotographic photoreceptor 500 shown in FIG. 5D, a photoconductive layer 502 is provided on a conductive substrate 501. The photoconductive layer 502 includes a charge generation layer 505 and a charge transport layer 506 made of a-Si: H, X, and an amorphous silicon (or amorphous carbon) surface layer 503 is provided thereon.
[0074]
【Example】
Hereinafter, the present invention will be described in more detail with reference to examples.
[0075]
(Example 1)
Using the deposited film forming apparatus shown in FIG. 3, a blocking layer, a photoconductive layer, and a surface are formed on a 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 1. Film formation was performed in the order of the layers, and six electrophotographic photosensitive members were formed simultaneously. At this time, the plasma is once formed in the reaction vessel 117 by applying high-frequency power having a frequency of 105 MHz from the first high-frequency power source 109 to the first high-frequency power introducing means 104 through the matching box 106, and then A high frequency power having a frequency of 105 MHz was applied from the second high frequency power source 107 to the second high frequency power introducing means 103 via the matching box 105 to supply the high frequency power into the reaction vessel 117. The plasma formation was determined based on the fluctuation of the internal pressure of the reaction vessel, and high frequency power was applied to the second high frequency power introducing means 103 when the internal pressure was stabilized.
[0076]
The reaction vessel 117 was made of a cylindrical alumina ceramic material, and the inner surface was blasted. Further, the high frequency power introducing means 104 and 103 were formed in a columnar shape having a diameter of 20 mm, and in particular, the surface of the first high frequency power introducing means 104 was sprayed with an alumina material.
[0077]
[Table 1]

[0078]
The number of spherical protrusions, charging ability unevenness, sensitivity unevenness, and variation within each lot of the electrophotographic photosensitive member produced under the above conditions were measured under the following conditions.
[0079]
(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 The total number of spherical protrusions in a total of five locations in a circumferential direction (251 mm) of 30 mm was determined. Similarly, the number of spherical protrusions of the six electrophotographic photosensitive members was measured, and the average of the six was used as the number of spherical protrusions. Therefore, the smaller the number of spherical protrusions, the better.
[0080]
Further, the number of spherical projections at the 0 mm position between the six pieces was compared, and the difference between the minimum value and the maximum value was defined as the variation in the lot of spherical projections.
[0081]
(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 having a wavelength of 660 nm) of 4 lux · sec, and a charger current value 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 was measured by measuring the charging ability at positions of +130 mm, +90 mm, 0 mm, −90 mm, and −130 mm in the longitudinal direction of the electrophotographic photosensitive member, and obtaining the difference between the maximum value and the minimum value of the six electrophotographic photosensitive members. The average of the body was defined as uneven charging ability. Therefore, the smaller the charging performance unevenness, the better.
[0082]
Further, the charging ability at the 0 mm position between the 6 pieces was compared, and the difference between the minimum value and the maximum value was determined as the variation in charging ability within the lot.
[0083]
(Uneven sensitivity)
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. Sensitivity was measured at positions of +130 mm, +90 mm, 0 mm, −90 mm, and −130 mm in the longitudinal direction of the electrophotographic photosensitive member, and the difference between the maximum value and the minimum value was defined as uneven sensitivity. The average of the six electrophotographic photosensitive members was defined as sensitivity unevenness. Therefore, the smaller the sensitivity unevenness in the longitudinal direction, the better.
[0084]
Furthermore, the sensitivity at the 0 mm position between the 6 pieces was compared, and the difference between the minimum value and the maximum value was defined as the variation in sensitivity within the lot.
[0085]
(Comparative Example 1)
Using the deposited film forming apparatus shown in FIG. 3, a blocking layer, a photoconductive layer, and a surface are formed on a 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 1. Film formation was performed in the order of the layers, and six electrophotographic photosensitive members were formed simultaneously. At this time, high-frequency power having a frequency of 105 MHz from the first high-frequency power source 109 is matched with the first high-frequency power introduction means 104 via the matching box 106, and high-frequency power having a frequency of 105 MHz is matched from the second high-frequency power source 107. The same operation as in Example 1 was performed except that the high-frequency power was simultaneously applied to the second high-frequency power introducing means 103 via the box 105 and supplied to the reaction vessel 117.
[0086]
The number of spherical protrusions, charging ability unevenness, sensitivity unevenness and in-lot variation of the electrophotographic photosensitive member produced under the above conditions were determined in the same manner as in Example 1, and the results are shown in Tables 2 and 3.
[0087]
[Table 2]

[0088]
[Table 3]

[0089]
From Table 2 and Table 3, by providing a time difference in the application start time of the high-frequency power to the first high-frequency power introduction means and the second high-frequency power introduction means, the number of spherical protrusions, charging capability unevenness, sensitivity unevenness, and in-lot variation are reduced. It turned out to be improved.
[0090]
(Example 2)
Using the deposited film forming apparatus shown in FIG. 1, on the cylindrical substrate (cylindrical aluminum cylinder 102 having a diameter of 80 mm and length of 358 mm), the blocking layer, photoconductive layer, surface Film formation was performed in the order of the layers, and six electrophotographic photosensitive members were formed simultaneously. At this time, a high frequency power having a frequency of 105 MHz is applied from the first high frequency power source 109 and a high frequency power having a frequency of 60 MHz from 110 is applied to the first high frequency power introducing means 104 through the matching box 106 to thereby react the reaction vessel. The second high-frequency power introducing means via the matching box 105 is supplied with high-frequency power having a frequency of 105 MHz from the second high-frequency power source 107 and high-frequency power having a frequency of 60 MHz from 108 after the plasma is once formed in 117. The high frequency power was applied to the reaction vessel 117. The plasma formation was determined based on the fluctuation of the internal pressure of the reaction vessel, and high frequency power was applied to the second high frequency power introducing means 103 when the internal pressure was stabilized.
[0091]
The reaction vessel 117 was made of a cylindrical alumina ceramic material, and the inner surface was blasted. Further, the high frequency power introducing means 104 and 103 were formed in a columnar shape having a diameter of 20 mm, and in particular, the surface of the first high frequency power introducing means 104 was sprayed with an alumina material.
[0092]
[Table 4]

[0093]
The number of spherical protrusions, charging ability unevenness, sensitivity unevenness and in-lot variation of the electrophotographic photosensitive member produced under the above conditions were measured in the same manner as in Example 1.
[0094]
(Comparative Example 2)
Using the deposited film forming apparatus shown in FIG. 1, on the cylindrical substrate (cylindrical aluminum cylinder 102 having a diameter of 80 mm and length of 358 mm), the blocking layer, photoconductive layer, surface Film formation was performed in the order of the layers, and six electrophotographic photosensitive members were formed simultaneously. At this time, the same method as in Example 2 was used except that high-frequency power was simultaneously applied to the first high-frequency power introduction means 104 and the second high-frequency power introduction means 103 to form plasma in the reaction vessel 117.
[0095]
The number of spherical protrusions, charging ability unevenness, sensitivity unevenness and in-lot variation of the electrophotographic photosensitive member produced under the above conditions were determined in the same manner as in Example 1, and the results are shown in Tables 5 and 6.
[0096]
(Example 3)
In the same manner as in Example 2, using the deposited film forming apparatus shown in FIG. 1, the blocking layer was formed on the cylindrical substrate (cylindrical aluminum cylinder 102 having a diameter of 80 mm and a length of 358 mm) with the conditions shown in Table 4. Then, a photoconductive layer and a surface layer were formed in this order, and six electrophotographic photosensitive members were simultaneously formed. At this time, a high frequency power having a frequency of 105 MHz is applied from the second high frequency power source 107 and a high frequency power having a frequency of 60 MHz is applied from the second high frequency power source 107 to the second high frequency power introducing means 103 via the matching box 105. The first high-frequency power introducing means via the matching box 106 is supplied with the high-frequency power having a frequency of 105 MHz from the first high-frequency power source 109 and the high-frequency power having a frequency of 60 MHz from 110 after the plasma is once formed in 117. The high-frequency power was applied to the reaction vessel 117 and supplied to the reaction vessel 117. In addition, the plasma formation was determined based on the fluctuation of the internal pressure of the reaction vessel, and high frequency power was applied to the first high frequency power introducing means 104 when the internal pressure was stabilized.
[0097]
The reaction vessel 117 was made of a cylindrical alumina ceramic material, and the inner surface was blasted. Further, the high frequency power introducing means 104 and 103 were formed in a columnar shape having a diameter of 20 mm, and in particular, the surface of the first high frequency power introducing means 104 was sprayed with an alumina material.
[0098]
For the number of spherical protrusions, charging ability unevenness, sensitivity unevenness and variation in each lot obtained in Example 2, Example 3 and Comparative Example 2, each measurement value of Comparative Example 2 was set to 100 and relative evaluation was performed. The results are shown in Tables 5 and 6.
[0099]
[Table 5]

[0100]
[Table 6]

[0101]
From Tables 5 and 6, the first high-frequency power introduction means and the second high-frequency power introduction means can be applied with a plurality of high-frequency powers having different frequencies. The second high-frequency power introducing means is provided outside the reaction vessel, and the time of application of the high-frequency power to the first high-frequency power introducing means and the second high-frequency power introducing means is set to be different from each other, so that the number of spherical protrusions and the charging ability are increased. It was found that unevenness, sensitivity unevenness, and in-lot variation were improved.
[0102]
It has also been found that it is more effective to apply high-frequency power having different frequencies in the order of the first high-frequency power introducing means inside the reaction vessel and then the second high-frequency power introducing means outside the reaction vessel.
[0103]
Example 4
Using the deposited film forming apparatus shown in FIG. 2, on the cylindrical substrate (cylindrical aluminum cylinder 102 having a diameter of 80 mm and a length of 358 mm), the blocking layer, photoconductive layer, surface Film formation was performed in the order of the layers, and a total of 10 electrophotographic photoreceptors were prepared for 10 lots.
[0104]
At this time, a high frequency power having a frequency of 105 MHz is applied from the first high frequency power source 209 and a high frequency power having a frequency of 60 MHz from 210 is applied to the first high frequency power introducing means 204 through the matching box 206 to thereby react the reaction vessel. After the plasma is once formed in 217, the second high-frequency power is introduced from the second high-frequency power source 207 through the matching box 205 to the second high-frequency power from the second high-frequency power source 207 and from the second high-frequency power through the matching box 205. The high frequency power was applied to the reaction vessel 217 by being applied to 203.
[0105]
In addition, the plasma formation was determined based on fluctuations in the internal pressure of the reaction vessel, and high frequency power was applied to the second high frequency power introducing means 203 when the internal pressure was stabilized.
[0106]
The reaction vessel 217 was made of a cylindrical alumina ceramic material, and the inner surface was blasted. Further, the high frequency power introducing means 204 and 203 were formed in a cylindrical shape having a diameter of 20 mm, and in particular, the surface of the first high frequency power introducing means 204 was sprayed with an alumina material.
[0107]
[Table 7]

[0108]
The lot variation of the number of spherical protrusions, charging ability and sensitivity of the electrophotographic photosensitive member produced under the above conditions was measured under the following conditions.
[0109]
(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. The total number of spherical projections at a total of five locations in a circumferential direction (251 mm) of 30 mm was determined and used as the number of spherical projections. Therefore, the smaller the number of spherical protrusions, the better.
[0110]
Further, the number of spherical protrusions between the ten pieces was compared, and the difference between the minimum value and the maximum value was determined as the lot variation of the spherical protrusions.
[0111]
(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. As the measurement location, the charging ability was measured at positions of +130 mm, +90 mm, 0 mm, −90 mm, and −130 mm in the longitudinal direction of the electrophotographic photosensitive member, and the average was defined as the charging ability. Therefore, the smaller the charging performance unevenness, the better.
[0112]
Further, the charging ability between the ten wires was compared, and the difference between the minimum value and the maximum value was determined as the lot variation of the charging ability.
[0113]
(Uneven sensitivity)
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. Sensitivity was measured at positions of +130 mm, +90 mm, 0 mm, −90 mm, and −130 mm in the longitudinal direction of the electrophotographic photosensitive member, and the average was taken as the sensitivity. Therefore, the smaller the sensitivity unevenness in the longitudinal direction, the better.
[0114]
Furthermore, the sensitivity between the 10 lines was compared, and the difference between the minimum value and the maximum value was determined as the sensitivity lot variation.
[0115]
(Comparative Example 3)
In the same manner as in Example 4, the blocking layer was formed on the cylindrical substrate (cylindrical aluminum cylinder 102 having a diameter of 80 mm and a length of 358 mm) using the deposited film forming apparatus shown in FIG. The film was formed in the order of the photoconductive layer and the surface layer, and a total of 10 lots of 10 electrophotographic photoreceptors were prepared. Then, the number of spherical protrusions, charging ability and sensitivity were evaluated in the same manner as in Example 4. .
[0116]
However, the first high frequency power introduction means 204 and the second high frequency power introduction means 203 were simultaneously applied without providing a time difference in the application start time of the high frequency power.
[0117]
With respect to the lot variations of the number of spherical protrusions, the charging ability, and the sensitivity obtained in Example 4 and Comparative Example 3, each measurement value of Comparative Example 3 was set to 100, and relative evaluation was performed. The results are shown in Table 8.
[0118]
[Table 8]

[0119]
From Table 8, the first high-frequency power introduction means and the second high-frequency power introduction means can be applied with a plurality of different high-frequency powers, and the first high-frequency power introduction means and the reaction container are further provided in the reaction vessel. The second high-frequency power introducing means is provided outside, and further, by providing a time difference in the application start time of the high-frequency power with respect to the first high-frequency power introducing means and the second high-frequency power introducing means, the number of spherical protrusions, charging ability, sensitivity It was found that lot variation was improved.
[0120]
【The invention's effect】
As described above, according to the present invention, in the formation of a deposited film by the high-frequency-PCVD method, image defects are reduced, characteristic variations between substrates and lots are suppressed, and uniformity and reproducibility are high and stable. A deposited film can be formed. Further, the deposition film formation time can be shortened and the utilization efficiency of the raw material gas can be improved, and the production cost can be reduced.
[0121]
As a result, it is possible to stably produce semiconductor devices having excellent characteristics, light receiving members for electrophotography, and the like at low cost.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing an example of a deposited film forming apparatus that can be used in the present invention.
FIG. 2 is a schematic configuration diagram showing an example of a deposited film forming apparatus that can be used in the present invention.
FIG. 3 is a schematic configuration diagram showing an example of a deposited film forming apparatus that can be used in the present invention.
FIG. 4 is a schematic configuration diagram showing an example of a VHF plasma CVD deposition film forming apparatus using a conventional VHF band frequency.
FIG. 5 is a diagram showing an example of the layer structure of an electrophotographic light-receiving member that can be formed according to the present invention.
[Explanation of symbols]
101, 201 ... Lid of reaction vessel
102, 202, 402 ... cylindrical base
103, 203 ... second high frequency power introducing means
104, 204... Second high frequency power introducing means
105, 205... Second matching box
106, 206... First matching box
107, 108, 207, 208 ... second high frequency power supply
109, 110, 209, 210... First high frequency power source
111, 311, 411 ... heater
112, 212, 412 ... Raw material gas supply means
113, 213, 413 .. Rotating shaft
114, 214, 414 .. Motor
115, 215, 415 ... Reduction gear
116, 216, 416 .. exhaust port
117, 217, 401 .. Reaction vessel
118, 218 ... conductive shield
405 ・ ・ Matching box
409 ... high frequency power supply
500 ... Photoconductor for electrophotography
501 ... Conductive substrate
502 ... Photoconductive layer
503 ... Surface layer
504 ... Charge injection blocking layer
505 ... Charge generation layer
506 ... Charge transport layer

Claims (5)

A cylindrical substrate is installed in a cylindrical reaction vessel capable of depressurization at least partially made of a dielectric material, and the raw material gas supplied into the cylindrical reaction vessel is fed by high-frequency power introduced from high-frequency power introduction means. In the deposited film forming method of decomposing and forming a deposited film on the cylindrical substrate, a first high-frequency power introducing means is provided inside the cylindrical reaction vessel, and further a first high-frequency power introducing means is provided outside the cylindrical reaction vessel. Two high-frequency power introduction means are set, and the first high-frequency power introduction means and the second high-frequency power introduction means are connected to independent high-frequency power sources, respectively, and a time difference is provided in the introduction start time of the high-frequency power. Film forming method. 2. The deposited film forming method according to claim 1, wherein the high frequency power is introduced into the second high frequency power introduction means after the high frequency power is introduced into the first high frequency power introduction means. 3. The high frequency power is introduced into the first high frequency power introducing means, and the high frequency power is introduced into the second high frequency power introducing means after the plasma is formed in the cylindrical reaction vessel. Deposited film forming method. A plurality of high frequency powers having different frequencies are introduced into each of the first high frequency power supply unit and the second high frequency power supply unit, and the power values of the plurality of high frequency powers to be introduced into the first high frequency power supply unit The frequency of one of the upper two high frequency powers is f1, the power value is P1, the frequency of the other high frequency power is f2, and the power value is P2. When the frequency of one high frequency power of the upper two power values is f1 ′, the power value is P1 ′, the frequency of the other high frequency power is f2 ′, and the power value is P2 ′, the following formulas (A) to ( The method for forming a deposited film according to any one of claims 1 to 3, wherein D) is satisfied.
10 MHz ≦ f2 <f1 ≦ 250 MHz (A)
0.1 ≦ P2 / (P1 + P2) ≦ 0.9 (B)
10 MHz ≦ f2 ′ <f1 ′ ≦ 250 MHz (C)
0.1 ≦ P2 ′ / (P1 ′ + P2 ′) ≦ 0.9 (D) 5. The method for forming a deposited film according to claim 1, wherein the deposited film is an electrophotographic photoreceptor composed of a non-single crystal material having at least silicon atoms as a base material.

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