JP3848018B2 - Functional deposition film manufacturing method and functional deposition film manufacturing apparatus - Google Patents

Description

この時の圧力、ガス流量から換算すると、ガスの平均滞在時間は約０．４秒程度であった。
【００８６】
本実施例では、図５（ａ）〜図５（ｃ）に示すような３通りのガス流量変化パターンにより３種類のサンプルを作製した。
【００８７】
サンプル▲１▼は、図５（ａ）に示すように、ガス流量が一定の時間と、この一定の時間のガス流量に対して矩形波状にガス流量が変化する時間とを有する、いわゆるガスに「ゆらぎ」を与えるものであり、周期Ｔとして４秒、Ｔ２として０．４秒として堆積膜を形成したものである。なお、ガス流量変化分Δｆは、時間Ｔ１における流量の２０％とした。
【００８８】
サンプル▲２▼はサンプル▲１▼に対する比較用のサンプルであり、図５（ｂ）に示すように、ガス流量を一定とし堆積膜を形成したものである。
【００８９】
サンプル▲３▼もサンプル▲１▼に対する比較用のサンプルであり、図５（ｃ）に示すように、Ｔ＝Ｔ２＝０．４秒とし、ガス流量が一定の時間がないものとして堆積膜を形成したものである。なお、ガス流量変化分Δｆは、サンプル▲１▼の時間Ｔ２におけるガス流量変化分Δｆと同じ２０％とした。
【００９０】
また、サンプル▲１▼ではガス流量変化分Δｆを時間Ｔ１における流量の２０％とし、サンプル▲３▼では、サンプル▲１▼のＴ２におけるガス流量変化と同じになるようにした。
【００９１】
作製した各サンプルについて、結合状態をウエハ上で、膜厚、導電率をガラス上で、以下に示す測定ポイントにおいて測定し、そのばらつきを評価した。測定ポイントは、第１のガス供給経路１と第２のガス供給経路２直下の点を８ヶ所と、第１のガス供給経路１と第２のガス供給経路２の間の点を８ヶ所との、計１６ヶ所とした。
【００９２】
まず、測定ポイントを中心として１ｃｍ角の領域を切り出し、紫外・可視光吸収分光計を用いて膜厚を測定した。次に赤外吸収分光にてＳｉＨとＳｉＨ₂に起因するピークをそれぞれ求め、両者の面積比（ＳｉＨ₂／ＳｉＨ）を計算した。最後にガラス基板上の堆積膜に櫛形電極を真空蒸着法により形成し、堆積膜の導電率を測定した。
【００９３】
本実施例の測定結果を表２に示す。
【００９４】
【表２】

なお、表１は、膜厚、ＳｉＨ₂／ＳｉＨ比、暗導電率の測定結果に関して、１６ヶ所のデータからばらつきを評価した後、標準偏差を計算し、ガス流量を一定としたサンプル▲２▼の標準偏差の値を１とした相対値で表している。
【００９５】
膜厚のばらつきの少なさに関しては、ガス流量が変化する時間Ｔ２をもつガス流量変化パターンを用いたサンプル▲１▼及びサンプル▲３▼の結果が良好であった。
【００９６】
ＳｉＨ₂／ＳｉＨ比、暗導電率の標準偏差に関しては、サンプル▲１▼が最も良好で、サンプル▲３▼が最も悪かった。これは、サンプル▲１▼の方法が供給するガスに適度な「ゆらぎ」を与えているのに対し、サンプル▲３▼ではガスの流れを乱しすぎており、その差が暗導電率のむらとして現れていると考えられる。
【００９７】
以上の結果から、供給するガスに適度な「ゆらぎ」を持たせ、かつ、複数のグループで相補的にガス流量を変化させる機能性堆積膜の製造方法により、堆積膜の特性むらが改善することが分かった。その際にはガス流量を常に変化させるだけでは本発明の効果が得られず、ガス流量を一定とする時間とガス流量を変化させる時間の双方が必要不可欠であるとともに両者のバランスを取ることで初めて本発明の効果が得られることが判明した。
【００９８】
（第２の実施例）
本実施例では、堆積膜を形成する装置として第１の実施例で示した堆積膜製造装置１０を用いた。また、第１の実施例で説明した基板８と同等の１２インチＳｉウエハ及び１２インチ四方ガラス基板上に表１で示す条件にてａ−Ｓｉ：Ｈ堆積膜を形成した。
【００９９】
ガス流量変化パターンとして、図６に示すように「ゆらぎ」となるところに正弦波状のガス流量の変化を与え、ガス流量変化分Δｆを、時間Ｔ１における流量の１％、５％、３０％、６０％、８０％とする５種類のガス流量変化パターンにて行った。周期Ｔは８秒、時間Ｔ２は２秒とした。また、比較としてガス流量を一定としたサンプルも同様に形成した。
【０１００】
得られたサンプルについて、膜厚、ＳｉＨ₂／ＳｉＨ比、導電率を第１の実施例と同様の１６ヵ所の測定ポイントにおいて求め、各測定値のばらつきを評価した。
【０１０１】
本実施例の測定結果を表３に示す。
【０１０２】
【表３】

なお、表３はガス流量を一定としたサンプルによる標準偏差を１とし、相対評価で表している。
【０１０３】
ガス流量変化分Δｆが１％のものに関しては、ガス流量を一定としたものに比べて効果は見られるものの、その違いは僅差であったのに対し、ガス流量変化分Δｆが５％〜６０％の範囲においては、膜厚、ＳｉＨ₂／ＳｉＨ比、導電率の全てに関して顕著な改善効果が見られた。一方、ガス流量変化分Δｆを８０％とした場合、膜厚、ＳｉＨ₂／ＳｉＨ比、導電率のばらつき改善は見られたものの、一定流量の際の値に近づいてしまった。この結果から、ガス流量変化分Δｆが５％〜６０％の範囲において、本発明の効果が最大限に得られることが確かめられた。
【０１０４】
（第３の実施例）
本実施例でも、堆積膜を形成する装置として第１の実施例で示した堆積膜製造装置１０を用いた。また、第１の実施例で説明した基板８と同等の１２インチＳｉウエハ及び１２インチ四方ガラス基板上に表１で示す条件にてａ−Ｓｉ：Ｈ堆積膜を形成した。
【０１０５】
ガス流量変化パターンとして、図７に示すように「ゆらぎ」となるところにパルス状のガス流量の変化を与え、時間Ｔ２の時間Ｔ１に対する時間比Ｔ２／Ｔ１が、０．５％、１％、１５％、３０％、４０％とする５種類のガス流量変化パターンにて堆積膜の製造を行った。ガス流量変化分Δｆに関しては３０％とし、周期Ｔを１０秒とした。また、比較としてガス流量を一定としたサンプルも同様に形成した。
【０１０６】
得られたサンプルについて、膜厚、ＳｉＨ₂／ＳｉＨ比、導電率を第１の実施例と同様の１６ヶ所の測定ポイントにおいて求め、各測定値のばらつきを評価した。
【０１０７】
本実施例の測定結果を表４に示す。
【０１０８】
【表４】

なお、表４はガス流量を一定としたサンプルによる標準偏差を１とし、相対評価で表している。
【０１０９】
時間比Ｔ２／Ｔ１が０．５％のものに関しては、ガス流量を一定としたものに比べて効果は見られるものの、その違いは少なかった。これは流量を変化させる時間が短すぎたためにガスが追従せず、ガスの「ゆらぎ」の効果が充分に発揮されなかったためと考えられる。それに対し、時間比Ｔ２／Ｔ１が１％〜３０％の範囲においては、膜厚、ＳｉＨ₂／ＳｉＨ比、導電率の全てに関して顕著な改善効果が見られた。また、ガス流量変化分Δｆが４０％の割合でガス流量を変化させた場合と比べても、時間比Ｔ２／Ｔ１が１〜３０％の結果は、膜厚、ＳｉＨ₂／ＳｉＨ比、暗導電率の全てにおいて標準偏差が良好であることがわかった。この結果から、時間比Ｔ２／Ｔ１が１％〜３０％の範囲において、本発明の効果が最大限に得られることが確かめられた。
【０１１０】
（第４の実施例）
本実施例でも、堆積膜を形成する装置として第１の実施例で示した堆積膜製造装置１０を用いた。また、第１の実施例で説明した基板８と同等の１２インチＳｉウエハ及び１２インチ四方ガラス基板上に表１で示す条件にてａ−Ｓｉ：Ｈ堆積膜を形成した。
【０１１１】
ガス流量変化パターンとして、図８に示すように「ゆらぎ」となるところに矩形波状のガス流量の変化を与え、ガスの反応容器内における平均滞在時間ｓ［ｓｅｃ］を基準として、周期Ｔを平均滞在時間ｓの０．５、１、１０、１００、２００倍とする６種類のガス流量変化パターンにて堆積膜の製造を行った。ガス流量変化分Δｆに関しては４０％とし、時間比Ｔ２／Ｔ１を２０％とした。また、比較としてガス流量を一定としたサンプルも同様に形成した。
【０１１２】
得られたサンプルについて、膜厚、ＳｉＨ₂／ＳｉＨ比、導電率を第１の実施例と同様の１６ヶ所の測定ポイントにおいて求め、各測定値のばらつきを評価した。
【０１１３】
本実施例の測定結果を表５に示す。
【０１１４】
【表５】

なお、表５は、ガス流量を一定としたサンプルによる標準偏差を１とし、相対評価で表している。
【０１１５】
周期Ｔが平均滞在時間ｓの０．５倍から１００倍までの範囲においては、膜厚、ＳｉＨ₂／ＳｉＨ比、導電率の全てに関して顕著な効果が見られた。一方、周期Ｔが平均滞在時間ｓの２００倍の周期でガスを変化させた場合、効果は見られるものの、膜厚、ＳｉＨ₂／ＳｉＨ比、暗導電率とも一定流量の際の値に近づいてしまった。この原因としては次のように考えられる。周期Ｔが平均滞在時間ｓの２００倍では、一定流量の時間Ｔ１が平均滞在時間に比べて十分に長く、一定流量の寄与が大きくなってしまう場合があるために最適な効果が得られなかったと考えられる。この結果から、本発明のガス流量変化に際し、周期Ｔが平均滞在時間ｓの０．５倍〜１００倍の範囲において、本発明の効果が最大限に得られることが確かめられた。
【０１１６】
（第５の実施例）
本実施例でも、堆積膜を形成する装置として、第１の実施例で示した堆積膜製造装置１０と基本的に同等のものを用いた。すなわち、第１の実施例で用いた堆積膜製造装置１０でのガス管３ａ、３ｂの吐出孔の方向は、基板８と平行な方向に形成されていたのに対し、本実施例では、後述するように、ガス管３ａ、３ｂの吐出孔の方向の角度を変化させて、堆積膜を形成するものであるが、それ以外は全て第１の実施例で用いた堆積膜製造装置１０と同じである。
【０１１７】
堆積膜を形成する基板は、第１の実施例で説明した基板８と同等であり、１２インチＳｉウエハ及び１２インチ四方ガラス基板上に表１で示す条件にてａ−Ｓｉ：Ｈ堆積膜を形成した。
【０１１８】
使用する第１のガス供給経路１と第２のガス供給経路２としては図９（ａ）〜図９（ｆ）に示すように、ガスの吐出方向に関して、基板と平行な面に対してカソード側に１０度、２０度、３０度と変化させたもの（図９（ａ）〜図９（ｃ））と、基板側に角度を持たせたもの（図９（ｄ）〜図９（ｆ））との計６種類を用いた。ガス流量変化パターンとしては、周期Ｔとして６秒、時間Ｔ２として１秒、ガス流量変化分Δｆを３５％とした。また比較のために、一定流量による堆積膜製造に関しても行った。
【０１１９】
得られたサンプルについて、膜厚、ＳｉＨ₂／ＳｉＨ比、導電率を第１の実施例と同様の１６ヶ所の測定ポイントにおいて求め、各測定値のばらつきを評価した。また本実験例では上記の検討に加え、球状突起の数を顕微鏡写真から見積もり、ガス流量を一定としたサンプルによる球状突起数と比較し、相対値で示した。
【０１２０】
本実施例の測定結果を表６に示す。
【０１２１】
【表６】

なお、表６は、ガス流量を一定としたサンプルによる標準偏差を１とし、相対評価で表した。
【０１２２】
全てのサンプルにおいて、ガス流量が一定のサンプルに比べてばらつきが少ないという結果が得られたが、球状突起の数に関しては、３０度のものがガス流量が一定のものとほとんど変わらなかったのに対し、１０、２０度のものに関しては球状突起の数が減少していた。
【０１２３】
この結果から、ガス吐出方向の基板面に平行な面に対する角度が、±２０度の範囲にある場合に、本発明の効果が最大限に得られることが確かめられた。
【０１２４】
以上、本発明の第１の実施形態の実施例として第１ないし第５の実施例について説明してきたが、以下に、本発明の第２の実施形態の実施例に関して説明する。
【０１２５】
（第６の実施例）
第１ないし第５の実施例では平行平板型の堆積膜製造装置を用いたが、本実施例では、円筒形同軸型のプラズマＣＶＤ装置を用いて基体に堆積膜を形成し、以下に示す試験を行い、形成された堆積膜の評価を行った。
【０１２６】
図１０（ａ）及び図１０（ｂ）に本実施例で用いた堆積膜製造装置４００の反応容器４１１の上面断面図及び堆積膜製造装置４００の概略構成図及びを示す。堆積膜製造装置４００は、円筒形状で、内周に各３本ずつの第１のガス管４１４ａ、第２のガス管４１４ｂ及び第３のガス管４１４ｃが１本ごとに交互に配され（計９本）、中央部に直径８０ｍｍの鏡面加工を施したアルミニウムシリンダである円筒状基体４１２が載置される反応容器４１１を有する。また、ガス供給源４９６から第１ないし第３のガス管４１４ａ、４１４ｂ、４１４ｃへのガス流量を独立に制御しながら供給する第１のガス管用マスフローコントローラ４２１ａ、第２のガス管用マスフローコントローラ４２１ｂ及び第３のガス管用マスフローコントローラ４１１ｃとを有し、さらに、反応容器４１１内を減圧するための不図示の排気装置と、反応容器４１１内でグロー放電を行わせるための高周波電源部４９９と有する。また、第１ないし第３のガス管４１４ａ、４１４ｂ、４１４ｃからのガスの吐出方向は、円筒状基体４１２の表面の接線に平行な平面から２０度反応容器４１１の壁面側に角度が付けられており、左右２方向にガスの吐出がなされる。
【０１２７】
各ガス管から供給されるガスのガス流量変化パターンを、図１１に示す。堆積膜製造装置４００における反応容器４１１内のガスの平均滞留時間ｓは、本実施例の内部のガス圧力、ガス流量では約１秒程度であることから、周期Ｔとしては２０秒、時間Ｔ２としては３秒とした。またガス流量は時間Ｔ１においては全ガス流量を３等分したガス流量とし、ガス流量変化分Δｆに関しては２５％とした。
【０１２８】
表７に本実施例における電子写真感光体の作製条件を示す。
【０１２９】
【表７】

なお、表７に示すように、SiH₄及びCH₄の流量は、表面層の形成時に時間的に変化させた。
【０１３０】
以上、表７に示す条件により作製された感光体の膜厚を測定したところ、同一装置でガス流量を一定としたものに比べ、均一性の向上が見られた。次に、この感光体を実験用に改造した電子写真装置（キヤノン製ＮＰ−６５５０）にセットして、電位特性の評価を行ったところ、感度の周方向むら、帯電能の周方向むらとも良好で、一定のガス流量で作製した感光体に比べてむらが減少していた。
【０１３１】
また、作製した感光体を正帯電して画像評価をした。画像欠陥の有無について、全面黒、全面白、全面ハーフトーンの複写原稿を用い、画像を詳細に調べたが、画像欠陥は全く見られなかった。
【０１３２】
（第７の実施例）
本実施例では、堆積膜の製造装置として、円筒形同軸型のプラズマＣＶＤ装置である図４（ａ）及び図４（ｂ）に示した第２の実施形態の堆積膜製造装置１００を用いて、基体に堆積膜を形成し、以下に示す試験を行い、形成された堆積膜の評価を行った。
【０１３３】
上述の第６の実施例で用いた堆積膜製造装置４００では各ガス管が各３本ずつの３つのグループに分けられ、計９本のガス管によりガスが供給されていたのに対し、本実施例の堆積膜製造装置１００は、各４本ずつの第１のガス管１１４ａと、第２のガス管１１４ｂとが１本ごと交互に配された（計８本）ものが用いられた。また、これに伴い、ガス供給源１９６からのガスのガス流量を独立に制御しながら第１及び第２のガス管１１４ａ、１１４ｂへのガスの供給を行うマスフローコントローラも第１のガス管用マスフローコントローラ１２１ａと第２のガス管用マスフローコントローラ１２１ｂとの２つが用いられた。また、第１及び第２のガス管１１４ａ、１１４ｂ、からのガスの吐出方向は、円筒状基体１１２の表面の接線に平行な平面から１０度反応容器１１１の壁面側に角度が付けられており、左右２方向にガスの吐出がなされる。
【０１３４】
なお、堆積膜製造装置１００の詳細の説明に関しては、すでに上述したため省略する。
【０１３５】
以上のような構成の堆積膜製造装置１００に、直径１０８ｍｍの鏡面加工を施したアルミニウムシリンダからなる円筒状基体１１２をセットし、その表面に電荷注入阻止層、光導電層、表面層からなる電子写真感光体を作製した。光導電層を２つに分離し、主に電荷発生をさせる領域と、主に電荷輸送を担う領域を設けることで機能分離型の感光体を完成させた。
【０１３６】
次に、本実施例におけるガス流量変化パターンを図１２に示す。堆積膜製造装置１００におけるガスの平均滞留時間ｓは、本実施例の内部のガス圧力、ガス流量では約１秒程度であることから、周期Ｔとしては１５秒、時間Ｔ２としては２秒とした。またガス流量は時間Ｔ１においては全ガス流量を２等分したガス流量とし、ガス流量変化分Δｆに関しては２０％とした。
【０１３７】
表８に本実施例における電子写真感光体の作製条件を示す。
【０１３８】
【表８】

なお、表８に示すように、SiH₄及びCH₄の流量は、表面層の形成時に時間的に変化させた。
【０１３９】
以上、表８に示した条件により作製された感光体の膜厚を測定したところ、同一の装置によりガスの供給を一定流量としたものに比べ、均一性の向上が見られた。次に、この感光体を実験用に改造した電子写真装置（キヤノン製ＮＰ−６０８５を基に、像露光を波長６８０ｎｍの半導体レーザで行うように改造したもの）にセットして、電位特性の評価を行った。レーザによる露光を行う複写機においては、特に明電位の感度のむら、ハーフトーン電位むらについて低く抑える必要があるが、本実施例で作製した感光体は一定流量で作製した感光体に比べてむらが減少し、極めて良好な結果が得られた。
【０１４０】
また、作製した感光体を正帯電して画像評価をした。画像欠陥の有無について、全面黒、全面白、全面ハーフトーンの複写原稿を用い、画像を詳細に調べたが、画像欠陥は全く見られなかった。
【０１４１】
【発明の効果】
以上説明したように本発明によれば、ガス供給工程が、ガス流量を独立して制御する複数のガス供給経路によりなされ、かつ、時間的に変動させる変動供給工程とを含むため、各ガスの供給に際して「ゆらぎ」が発生し、これにより、真空容器内のガスの滞留の発達を抑制することができる。よって、滞留による影響を受けることなく、特性むらの抑制された機能性堆積膜が製造されることとなる。また、変動供給工程における各ガス供給経路から供給されるガスのガス流量の総和が、一定供給工程のガス流量の総和と略同一であるため、所望の機能性堆積膜の形成に必要なガス流量が確保される。
【０１４２】
さらに、ガスの滞留の発達の抑制をガス供給手段の機械的特性の精度管理によらず、各ガスの供給に際する「ゆらぎ」により行うため、精度管理の低減がなされる。
【図面の簡単な説明】
【図１】本発明の第１の実施形態の一例である堆積膜製造装置の概略構成図である。
【図２】矩形波状のガス流量変化パターンを説明するグラフである。
【図３】別のガス流量変化パターンを説明するグラフである。
【図４】本発明の第２の実施形態の一例である堆積膜製造装置の上面断面図及び概略構成図である。
【図５】本発明の第１の実施例で用いた各ガス供給経路から供給されるガスのガス流量変化パターンを示すグラフである。
【図６】本発明の第２の実施例で用いた各ガス供給経路から供給されるガスのガス流量変化パターンを示すグラフである。
【図７】本発明の第３の実施例で用いた各ガス供給経路から供給されるガスのガス流量変化パターンを示すグラフである。
【図８】本発明の第４の実施例で用いた各ガス供給経路から供給されるガスのガス流量変化パターンを示すグラフである。
【図９】本発明の第５の実施例で試された、各ガス管からのガスの吐出方向を示す模式図である。
【図１０】本発明の第６の実施例で用いた堆積膜製造装置の上面断面図及び概略構成図である。
【図１１】本発明の第６の実施例で用いた各ガス管から供給されるガスのガス流量変化パターンを示すグラフである。
【図１２】本発明の第７の実施例で用いた各ガス管から供給されるガスのガス流量変化パターンを示すグラフである。
【図１３】従来の一例である堆積膜製造装置内に生じたガスの滞留を説明する図である。
【符号の説明】
１ 第１のガス供給経路
１ａ 第１のガス流量制御部
２ 第２のガス供給経路
２ａ 第２のガス流量制御部
３ａ、３ｂ ガス管
４ａ、４ｂ ガス供給手段
５ 高周波電源
６ カソード
７ アース電極
８ 基板
９ 反応容器
１０ 堆積膜製造装置
１１、１２、１３、１４、７１、７２、７３ マスフローコントローラ
２１、２２、２３、２４ ボンベ
３１、３２、３３、３４ ボンベ用バルブ
４１、４２、４３、４４ 流入バルブ
５１、５２、５３、５４ 流出バルブ
６０ 補助バルブ
６１、６２、６３、６４ 圧力調整器
１００、４００ 堆積装置
１１１、４１１ 反応容器
１１２、４１２ 円筒状基体
１１３ 基体加熱用ヒータ
１１４ａ、４１４ａ 第１のガス管
１１４ｂ、４１４ｂ 第２のガス管
４１４ｃ 第３のガス管
１１５ マッチングボックス
１１６ 高周波電源
１１７ 反応容器リークバルブ
１１８ メイン排気バルブ
１１９ 真空計
１９７ 堆積膜形成部
１９８ 排気部
１９９、４９９ 高周波電源部
２００ ガス供給部
４２１ａ 第１のマスフローコントローラ
４２１ｂ 第２のマスフローコントローラ
４２１ｃ 第３のマスフローコントローラ
４９６ ガス供給源[0001]
BACKGROUND OF THE INVENTION
The present invention is a plasma CVD capable of satisfactorily forming crystalline and non-single crystalline functional deposition films useful for semiconductor devices, electrophotographic photoreceptor devices, image input line sensors, imaging devices, photovoltaic devices and the like. The present invention relates to a method for producing a functional deposited film using the method and an apparatus for producing the functional deposited film.
[0002]
[Prior art]
There are various methods for plasma processing apparatuses used in semiconductors and the like depending on their applications. In particular, plasma CVD is widely used to form functional deposition films such as oxide films, nitride films, and amorphous silicon-based semiconductor films because of their high controllability and good physical properties of the deposited films. . For example, using direct current or high frequency (RF, VHF) or microwave, the gas used as the raw material of the deposited film is decomposed by glow discharge or the like, and thin film is formed on a substrate such as glass, quartz, heat resistant synthetic resin film, stainless steel or aluminum. A method for forming a deposited film has been put to practical use in a method for forming an amorphous silicon light receiving member for electrophotography, and various apparatuses have been proposed.
[0003]
In recent years, the area of semiconductor devices has been increased, and improvement of uniformity in a large area and cost reduction have become major issues.
[0004]
Conventional plasma processing apparatuses have been developed with a focus on uniform gas distribution in order to improve the uniformity of film thickness and characteristics. For example, in a parallel plate type plasma CVD apparatus, a gas supply means that also serves as an electrode has a shower head structure, and gas is supplied uniformly to the substrate surface, or a cylindrical coaxial plasma CVD apparatus in an electrophotographic photoreceptor manufacturing apparatus. However, as disclosed in JP-A-59-213439, a wall discharge type gas supply means that also serves as an electrode is employed.
[0005]
Although it was possible to improve the uniformity of film thickness and characteristics by these, it is a structure in which gas is sprayed directly toward the substrate, so dust and powdery gas phase reaction products etc. get on the substrate on the gas flow In some cases, the hemisphere or protrusion abnormal growth (hereinafter, referred to as a spherical protrusion) tends to occur due to adhesion to the surface. On the other hand, for example, in JP-A-10-168573, a plurality of gas introduction pipes (hereinafter referred to as gas pipes) are arranged as a gas supply means between a cathode and a substrate, and gas is supplied from the left and right sides of the gas pipe. A method of preventing dust and the like from reaching the substrate surface by discharging at an angle parallel to the substrate surface or at a slight angle from the cathode direction is disclosed. In addition, when a cylindrical deposited film manufacturing apparatus is used, a method of forming a deposited film while rotating the substrate is also used in order to further improve the uniformity of film thickness and characteristics in the circumferential direction.
[0006]
In addition, although not strictly a plasma CVD apparatus, for example, in Japanese Patent Application Laid-Open No. 9-202967, by alternately supplying gas from a plurality of gas nozzles in a sputtering apparatus, target erosion unevenness and film characteristic unevenness are disclosed. A method of preventing this is disclosed.
[0007]
[Problems to be solved by the invention]
As a result of the improvements as described above, it has become possible to achieve both improvement in film properties and uniformity. However, recent functional devices have higher density and higher integration, and image devices have further increased in definition, and there is an increasing need to reduce minute film thickness unevenness and characteristic unevenness. For example, an electrophotographic photosensitive member often requires a halftone image when copying a photo or the like or when copying a full color. In such a case, minute characteristic unevenness becomes a big problem. For this reason, further uniformity has been required for the thickness and characteristics of the deposited film.
[0008]
In addition, there is a case in which a method for suppressing unevenness in the characteristics of the deposited film in the circumferential direction by rotating the substrate or the substrate may be used. This method is very effective in suppressing unevenness, but not only the cost of the device increases due to the complexity of the device, but also the rotating part needs to be vacuum-sealed. There is always a risk of occurrence. Therefore, maintenance costs and management costs cannot be ignored.
[0009]
On the other hand, paying attention to the gas flow in the deposited film manufacturing apparatus, in many of the conventional techniques, the gas flow is steady, and the gas may stay partially. FIG. 13 is a view for explaining the retention of gas generated in a deposited film manufacturing apparatus as an example of the prior art.
[0010]
The deposited film manufacturing apparatus 210 includes a ground electrode 207 on which a substrate 208 on which a deposited film is formed is placed in a reaction vessel 209, and a cathode 206 disposed so as to face the ground electrode 207. A gas supply path 201 including a gas pipe for supply is provided. Further, an exhaust device (not shown) is connected to the reaction vessel 209 in order to set the inside of the reaction vessel 209 to a desired vacuum pressure.
[0011]
Next, an outline of the procedure for forming the deposited film will be described.
[0012]
First, after the substrate 208 is placed on the ground electrode 207, the exhaust device is evacuated to reduce the pressure in the reaction vessel 209 to a desired vacuum pressure. Next, a gas as a raw material is supplied into the reaction vessel 209 from the gas supply path 201. At this time, the gas is discharged from the gas pipe of the gas supply path 201 toward the cathode 206. Next, plasma is generated between the cathode 206 and the ground electrode 207 by applying high-frequency power from the external high-frequency power source 205 to the cathode 206. As a result, a deposited film is generated on the substrate 208.
[0013]
In the deposited film manufacturing apparatus 210, the gas supply path 201 is basically stationary with respect to the gas flow rate. Further, although the gas pipe is managed so as to discharge to the cathode 6 side, it is assumed that the gas pipe 203a has a variation at the time of management. Then, gas retention 204 occurs in the space just in the middle between the poorly managed gas pipe 203a and the adjacent gas pipe 203b. In such a state where a stagnation has occurred, a constant flow of gas is continuously flowed, and then high-frequency power is applied from the high-frequency power source 205 to generate plasma between the cathode 206 and the ground electrode 207 to deposit the film. It is considered that the characteristic unevenness occurs in the deposited film formed on the surface of the substrate 208 corresponding to the stay 204. In the conventional deposited film manufacturing apparatus 210, management of the gas discharge direction and accuracy management of the gas pipes 203a and 203b are required to suppress the occurrence of such stagnation.
[0014]
On the other hand, in order to avoid such a problem, for example, a technique such as the above-mentioned Japanese Patent Application Laid-Open No. 9-202967 is also conceivable. Or, the average characteristics of the entire deposited film are greatly changed. Moreover, since the change in the gas flow rate is too large, the powder generated inside the deposited film manufacturing apparatus is likely to rise and spherical protrusions are likely to occur.
[0015]
Accordingly, a first object of the present invention is to provide a method for producing a functional deposited film and an apparatus for producing the functional deposited film, in which the characteristic unevenness of the functional deposited film is suppressed.
[0016]
It is a second object of the present invention to provide a method for producing a functional deposited film and a functional deposition film producing apparatus with reduced accuracy control relating to retention control.
[0017]
[Means for Solving the Problems]
In order to achieve the above object, the method for producing a functional deposition film according to the present invention includes a gas serving as a raw material for the functional deposition film in a vacuum container in which a substrate on which the functional deposition film is to be formed is placed. In a method for producing a functional deposited film, the method includes a gas supply step of supplying gas from a gas supply path, and a plasma generation step of generating plasma in the vacuum vessel.
The gas supply step supplies the gas from a plurality of gas supply paths, and
A constant supply step in which the gas flow rate from each of the gas supply paths is constant;
A variable supply step of changing the gas flow rate with respect to the gas flow rate of the constant supply step so that the sum of the gas flow rates from the gas supply paths is substantially the same as the sum of the gas flow rates of the constant supply step. Including.
[0018]
In the method for producing a functional deposited film of the present invention as described above, the gas is supplied by a plurality of gas supply paths that independently control the gas flow rate, and the gas supply process is configured to adjust each gas flow rate over time. In addition to the constant supply process for supplying a predetermined amount, a fluctuation supply process for changing the flow rate of each gas with respect to the constant supply process, a “fluctuation” occurs during the supply of each gas. , Gas retention in the vacuum vessel is suppressed. In addition, the sum of the gas flow rates of the gases supplied from the gas supply paths in the variable supply process is substantially the same as the sum of the gas flow rates from the gas supply paths in the constant supply process. The gas flow rate necessary for formation is ensured. The variable supply process referred to here may be one in which the gas flow rate changes stepwise, or, as will be described below, changes continuously in time, such as sinusoidal or triangular. There may be.
[0019]
The variable supply step of the method for producing a functional deposited film of the present invention may include a step of continuously changing the gas flow rate in time, or the constant supply step and the variable supply step are alternately performed. It may be repeated.
[0020]
In the variable supply process From each gas supply path The peak value of the gas flow rate and the constant supply process From each gas supply path The difference from the gas flow rate is From each gas supply path It may be 5% or more and 60% or less of the gas flow rate, and the time required for the variable supply process may be 1% or more and 30% or less of the time required for the constant supply process. The process is repeated periodically, and the cycle is
s = pV / f
s: Average residence time of gas in the vacuum vessel
V: Internal volume in the vacuum vessel
p: Pressure during plasma generation process
f: Gas flow rate supplied into the vacuum vessel
It may be 0.5 to 100 times the average stay time s represented by
[0021]
Further, in the gas supply process, each gas is supplied into the vacuum container by discharging the gas from a plurality of gas supply paths within a range of ± 20 degrees with respect to a virtual plane parallel to the surface of the substrate. A process may be included.
[0022]
The functional deposition film manufacturing apparatus of the present invention includes a vacuum vessel in which a substrate on which a functional deposition film is to be formed is placed, a gas supply unit that supplies a gas that is a raw material of the functional deposition film, In the functional deposition film manufacturing apparatus having plasma means for generating plasma in the vacuum vessel,
The gas supply means comprises at least one gas source and a plurality of gas supply paths for supplying gas from the gas source into the vacuum vessel,
The gas is supplied such that the sum of the gas flow rate from each gas supply means and the gas flow rate from each gas supply means is substantially the same as the sum of the gas flow rates from the gas supply means. It has a plurality of gas flow rate control means for controlling each gas flow rate of each of the gas supply means by a gas flow rate change pattern comprising a variable supply time for changing the flow rate with respect to the gas flow rate of the constant supply time.
[0023]
The variable supply time referred to here may be one in which the gas flow rate is changed stepwise, or it is continuously changed in time, such as a sine wave or triangular wave, as will be described below. There may be.
[0024]
The gas used in the functional deposition film manufacturing apparatus of the present invention may be a mixed gas composed of a plurality of types of gases, and each gas flow rate control means continuously adjusts the gas flow rate over a variable supply time. The gas flow rate change pattern by each gas flow rate control means may be such that a constant supply time and a variable supply time are alternately repeated.
[0025]
Also in variable supply time From each gas supply means The peak value of the gas flow rate and the constant supply time From each gas supply means The difference from the gas flow rate is a constant supply time. From each gas supply means The gas flow rate may be 5% to 60%, the variable supply time may be 1% to 30% of the constant supply time, and the variable supply time and the constant supply time are periodically Repeated and its period is
s = pV / f
s: Average residence time of gas in the vacuum vessel
V: Internal volume in the vacuum vessel
p: Pressure at the time of plasma generation
f: Gas flow rate supplied into the vacuum vessel
It may be 0.5 to 100 times the average stay time s represented by
[0026]
Further, the gas supply means may comprise a plurality of gas pipes in which discharge holes for discharging the gas into the vacuum vessel are formed in a range of ± 20 degrees with respect to a virtual plane parallel to the surface of the substrate. Good.
[0027]
Next, the background to solving the above problems will be described.
[0028]
The present inventors first analyzed the steady gas flow and tried to make the film thickness and characteristics of the deposited film more uniform while suppressing the spherical protrusions. For example, instead of using a shower head or wall discharge type as a gas supply means, a gas pipe that is highly effective in suppressing the occurrence of spherical protrusions is adopted, and the gas distribution direction is changed in various ways to consider uniform gas distribution did. By taking measures such as increasing the number of gas pipes, the gas discharge direction, and the number of gas discharge holes, the gas distribution was made uniform, and the uniformity of film thickness and characteristics was improved. However, the discharge direction of the gas pipe must be strictly managed when installing the gas pipe, and the management becomes more complicated as the number of gas pipes and the discharge direction increase. Further, it has been found that when the area becomes large, the length of the gas pipe becomes long, and the distortion and deflection of the gas pipe cannot be ignored. If these are left unattended, gas stagnation may occur at unexpected sites, and uneven characteristics and spherical protrusions may occur.
[0029]
Therefore, focusing on gas stagnation, we considered whether it is possible to prevent gas stagnation while keeping the gas flow as uniform as possible. The inventors first divided the gas supply means into a plurality of groups, distributed the gas mixed in advance to each group, and made it possible to control the flow rate independently of each other. Next, each group basically realized a steady gas flow and then gave a slight “fluctuation” to the gas flow. By appropriately selecting this “fluctuation” amount, the thickness unevenness of the deposited film and the property unevenness can be drastically reduced even if the accuracy control of the gas pipe and the control at the time of installation are not strictly performed as before. It was found to be.
[0030]
The reason is considered as follows.
[0031]
In the steady gas discharge method, the gas flow in the CVD apparatus also becomes steady, and it is considered that uneven gas distribution occurs in a specific place. The unevenness of gas distribution can be suppressed to a considerable level by devising the gas discharge method as described above, but the balance slightly changes due to variations in gas supply means and variations in management. . Even if the retention of gas generated at that time is very small, it cannot be ignored in the case of a deposited film that requires minute uniformity. It is considered that the unevenness of the film thickness and the characteristic unevenness of the deposited film occur due to the accumulation of the unevenness of the gas distribution due to such subtle retention.
[0032]
Therefore, as described above, by giving a moderate “fluctuation” to the gas flow, and by providing a time to keep the gas flow constant to such an extent that the “fluctuation” is sufficiently mitigated, and balancing both, It is considered that unnecessary stagnation due to such variations can be substantially eliminated, and the characteristic unevenness of the deposited film is reduced. In addition, the management of the gas discharge direction and the accuracy management of the gas pipe, which have been required so far, have been greatly eased, and the management cost related to them can be greatly reduced.
[0033]
In addition, if the above-mentioned unnecessary retention is to be suppressed only by strictly managing the gas pipe, the distribution of gas in the reaction vessel changes each time the type of deposition film and the formation conditions are changed. Therefore, it is necessary to review the management items each time and optimize the arrangement and angle of the gas discharge holes, which is disadvantageous in terms of development costs and time. On the other hand, the method of the present invention does not require large-scale equipment, and only changes the gas flow. By varying and changing the change pattern in various ways, various deposition films and various formations can be achieved. It can be applied to devices having conditions or various shapes. Moreover, it can respond appropriately and flexibly according to the characteristics and uneven shape required for the deposited film. In addition, cost effectiveness is high, and as a result, production costs can be reduced.
[0034]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 shows a schematic configuration diagram of a deposited film manufacturing apparatus 10 which is an example of the first embodiment of the present invention.
[0035]
The deposited film manufacturing apparatus 10 has a ground electrode 7 on which a substrate 8 on which a deposited film is formed is placed in a reaction vessel 9 and a cathode 6 disposed so as to face the ground electrode 7, and supplies gas. A first gas supply path 1 and a second gas supply path 2 for supplying the gas from the means 4a and 4b into the reaction vessel 9 are provided. A first gas flow control unit 1a and a second gas flow control unit 2a are disposed in the first gas supply path 1 and the second gas supply path 2 formed of a plurality of gas pipes, respectively. The gas flow rate is controlled independently. Further, an exhaust device (not shown) is connected to the reaction vessel 9 in order to set the inside of the reaction vessel 9 to a desired vacuum pressure.
[0036]
Next, an outline of the procedure for forming the deposited film will be described.
[0037]
First, after placing the substrate 8 on the ground electrode 7, the exhaust device is evacuated to lower the pressure in the reaction vessel 9 to a desired vacuum pressure. Next, gas is supplied from the first gas supply path 1 and the second gas supply path 2. At this time, the gas is discharged toward the cathode 6 from the gas pipe 3a of the first gas supply path 1 and the gas pipe 3b of the second gas supply path 2. The gas pipe 3a and the gas pipe 3b are pipes extending horizontally in the depth direction of FIG. 1, and a plurality of holes through which gas is discharged in the direction of the cathode 6 are formed in parallel in these pipes.
Next, plasma is generated between the cathode 6 and the ground electrode 7 by applying high-frequency power from the external high-frequency power source 5 to the cathode 6. Thereby, a deposited film is generated on the substrate 8.
[0038]
As described above, when the deposited film is formed on the substrate 8, the gas flow rate change pattern of the gas supplied from the first gas supply path 1 and the second gas supply path 2 is the first gas flow rate control unit. As shown in FIG. 2, the time T2 for changing to a rectangular wave shape and the time T1 for keeping the gas flow rate constant are periodically changed with a period T by the 1a and the second gas flow rate control unit 2a.
[0039]
2, the upper diagram shows the gas flow rate change pattern of the gas supplied from the first gas supply path 1, and the lower diagram shows the gas flow rate change pattern of the gas supplied from the second gas supply path 2. ing. 100% on the vertical axis in FIG. 2 is for satisfying the total amount of gas required for the formation of the deposited film when the gas flow rate is supplied at a constant amount within the specified time without changing the time. It means gas flow rate. Further, the fluctuation from 100% is shown as + A% when increasing, and -A% when decreasing. In the period T, the gas flow rate is constant at 100% at time T1, and the gas flow rate is changed from 100% to ± A% at time T2. In the first half of the time T2, the gas flow rate of the gas supplied from the second gas supply path 2 is increased by + A% by the amount by which the gas flow rate of the gas supplied from the first gas supply path 1 is increased by + A%. In the latter half, the gas flow rate of the gas supplied from the first gas supply path 1 is reduced by -A%, and the gas flow rate of the gas supplied from the second gas supply path 2 is increased by + A%. By increasing it, the gas flow rate from each gas pipe is always kept at 100%.
[0040]
As for this subtle “fluctuation”, the amount of change in gas flow Δf (the difference between the flow rate at the peak position and the flow rate at a certain portion, ± A% in FIG. 2), and the time during which the gas flow rate is constant The effects of the present embodiment can be obtained individually in any range by appropriately selecting T1, changing time T2, and period T, and paying attention to the combination so that the plasma does not fluctuate unnecessarily. The following ranges are preferable with respect to the value of.
[0041]
Regarding the gas flow rate change Δf, it is desirable that the gas flow rate at time T1 is 100%, and the value is within a range of 5% to 60%. This range is desirable because if the amount of change Δf in the gas flow rate is too large, the change in the gas flow becomes too large, and the change in the plasma distribution corresponding to the change in the gas becomes too large. This is because, if the gas flow rate change Δf is too small, the retention removal effect due to the “fluctuation” of the gas flow may be lost.
[0042]
Regarding the time ratio between the time T1 and the time T2, it is desirable that the time ratio T2 / T1 represented by using the time T1 and the time T2 is a value within a range of 1% to 30%. This range is desirable when the time ratio T2 / T1 is smaller than 1%, because the influence of the staying gas is not removed, so that the deposition film is formed at a constant gas flow rate. If the difference may be difficult to appear and the time ratio T2 / T1 is larger than 30%, the gas flow changes greatly, and the plasma greatly fluctuates accordingly, and the characteristics of the deposited film deteriorate. This is due to the fact that it may end up.
[0043]
The period T is considered based on the average residence time in the deposited film manufacturing apparatus 10, that is, the time in the reaction vessel 9 from the gas supply means 4a, 4b to the exhaust means. This average residence time s [sec] is defined as V [m ^Three ], The pressure during the reaction is p [atm], and the total flow rate of the mixed gas is f [m ^Three / Sec]
s = pV / f
Can be expressed as When this average stay time s is used as a reference, one period T is desirably a value within a range of 0.5 to 100 times s. In this range, it is desirable that the gas flow rate is always changing when it is less than 0.5 times, so that the plasma is likely to become unstable. Even if the unnecessary stagnation is wiped off by the “fluctuation”, the time T1 where the flow rate is constant is too long, and as a result, it may be difficult to show a noticeable difference from the case where it is formed at a constant flow rate. Is.
[0044]
As described above, the rectangular wave-shaped gas flow rate change pattern shown in FIG. 2 has been described. However, as other gas flow rate change pattern examples, FIGS. 3A to 3C show different gas flow rate change patterns. Indicates.
[0045]
In addition, since the meaning of each symbol in FIG. 3A to FIG.
[0046]
FIG. 3A shows an example in which the gas flow rate at time T2 is changed in a sine wave shape. Note that the phases of the sine waves of the first gas supply path 1 and the second gas supply path 2 at time T2 are reversed. Such a change pattern is more preferable because the change in gas flow rate is gentle and the plasma is hardly disturbed even when the amplitude is relatively large.
[0047]
FIG. 3 (b) shows a pulse wave-like gas flow rate change pattern that has no periodicity within time T2, but has a periodicity in combination with time T1. In this case, each phase of the next time T2 ′ separated by the period T is opposite to the time T2, and the period T by the time T1 and the time T2 and the period T by the time T1 and the time T2 ′ are sequentially repeated. It is.
[0048]
Further, the deposited film manufacturing apparatus 10 of the present embodiment shown in FIG. 1 has been described by using a gas supply path having two paths as an example, but three or more paths may be used. The gas flow rate change pattern is shown in FIG. In FIG. 3C, the deposited film manufacturing apparatus 10 includes a third gas flow rate control unit (not shown) in addition to the first gas supply path 1 and the second gas supply path 2 as gas supply paths. It shows an example of each gas flow rate change pattern in the case where there are three gas supply paths that have a third gas supply path (not shown). In this way, if the total flow rate at each time can be changed so as to be always constant, the present invention can be applied even when there are three or more routes. In addition, in the case of a configuration with three or more routes as described above, it is desirable to arrange the supply routes alternately or sequentially.
[0049]
In addition, fluctuations in the gas flow rate change patterns shown in FIGS. 3A to 3C have periodicity, and the flow rate of each supply path changes in a complementary manner, so that all of the flow into the deposited film manufacturing apparatus can be obtained. As long as the gas flow rate is set to be constant, and desirably the supply paths are alternately or sequentially arranged, any gas flow rate change pattern such as a triangular wave shape may be used.
[0050]
As described above, according to the present embodiment, when the deposited film is formed, the first gas flow path control unit 1a and the second gas flow rate control unit 2a perform the first gas supply path 1 and the second gas flow control unit 2a. By setting the gas flow rate change Δf, the time ratio T2 / T1, and the period T within the desired ranges and giving “fluctuation” to the gas flow rate of the gas supplied from the gas supply path 2, Retention can be prevented. Thereby, it is possible to form a deposited film having substantially no characteristic unevenness. In addition, since the stagnation of the gas is controlled not by the accuracy control of the mechanical characteristics of the first gas supply path 1 and the second gas supply path 2, but by the “fluctuation” in supplying each gas, the accuracy control is performed. Is reduced.
(Second Embodiment)
Next, FIG. 4A and FIG. 4B show a top sectional view of the reaction vessel 111 of the deposited film manufacturing apparatus 100 and a schematic configuration diagram of the deposited film manufacturing apparatus 100 according to the second embodiment of the present invention.
[0051]
The deposited film manufacturing apparatus 100 of the present embodiment uses a plasma CVD method having a cylindrical coaxial structure suitable for forming a deposited film on a cylindrical cylindrical substrate 112 that is an electrophotographic photosensitive member used in an electrophotographic apparatus. It is an example of what was there.
[0052]
The deposited film manufacturing apparatus 100 has a cylindrical shape, and a plurality of first gas pipes 114a and second gas pipes 114b are alternately arranged along the circumferential direction at an inner peripheral edge, and a cylindrical substrate 112 is provided at the center. A deposited film forming unit 197 having a reaction vessel 111 mounted thereon, a gas supply unit 200 that supplies gas to the reaction vessel 111 while controlling a gas flow rate from a gas supply source 196, a gas supply unit 200, and a reaction An exhaust unit 198 including an exhaust device (not shown) for decompressing the inside of the vessel 111 and a high-frequency power source unit 199 for causing glow discharge in the reaction vessel 111 are roughly configured.
[0053]
First, the configuration of the deposited film forming unit 197 will be described in detail.
[0054]
In the reaction vessel 111 also serving as the cathode electrode, four first gas pipes 114a and second gas pipes 114b are provided alternately along the inner periphery of the reaction vessel 111 every other line. Yes. In addition, a substrate heating heater 113 is provided for heating the cylindrical cylindrical substrate 112 placed in the center from the inner peripheral side of the cylinder.
[0055]
Here, discharge of gas from the first gas pipe 114a and the second gas pipe 114b will be described.
[0056]
A number of discharge holes are formed in the first gas pipe 114 a and the second gas pipe 114 b, and gas is discharged into the reaction vessel 111 from these discharge holes. At this time, the effect of the present invention can be obtained regardless of the gas discharge direction. More preferably, the gas discharge direction is set to the surface of the cylindrical substrate 112 as shown in the enlarged view of FIG. It is desirable to set the angle parallel to the tangent line (direction indicated by (1)) or within the range of ± 20 degrees from the angle because it has the effect of further suppressing characteristic unevenness and spherical protrusions. In the case of exceeding the range of ± 20 degrees, especially in the direction of the cylindrical substrate 112, gas is likely to directly hit the cylindrical substrate 112 as in the case of the shower head type or wall discharge type. An object may be easily attached to the cylindrical substrate 112.
[0057]
The gas discharge direction is preferably one direction or two directions (bidirectional). If attention is paid to the gas distribution, the gas may be discharged in many directions. For example, in the case of one direction, as an example, a group that blows in one direction clockwise as viewed from above is mixed with a group that ejects counterclockwise. Normally, for example, by flowing gas constantly in a clockwise direction and discharging a small amount of counterclockwise gas when the gas flow rate is changed, “fluctuation” can be generated in the steady flow of gas. In the case of two directions, for example, as shown in the enlarged view of FIG. 4A, the direction may be parallel to the tangent to the surface of the cylindrical substrate 112 (direction indicated by (1)), and the angle from the parallel direction may be set. It may be provided (direction indicated by (2)). In addition to giving “fluctuation” to the gas flow, as shown in the enlarged view of FIG. 4 (a), by discharging the gas, gas from adjacent gas pipes collide with each other and easily diffuse. It is possible to further promote uniform gas distribution while suppressing unnecessary stagnation.
[0058]
Next, the configuration of the gas supply unit 200 will be described in detail.
[0059]
The gas supply unit 200 is made of SiH. _Four , GeH _Four , H ₂ , CH _Four , B ₂ H ₆ , PH _Three Gas supply provided with cylinders 21, 22, 23, 24 for each source gas, cylinder valves 31, 32, 33, 34, pressure regulators 61, 62, 63, 64 and inflow valves 41, 42, 43, 44 It has a source 196, mass flow controllers 11, 12, 13, 14, outflow valves 51, 52, 53, 54, an auxiliary valve 60, and mass flow controllers 71, 72, 73.
[0060]
In FIG. 4 (b), only four systems to which gas is supplied from four cylinders 21, 22, 23, and 24 are illustrated, but three or less systems may be used, and five or more systems may be used. There may be.
[0061]
Each pressure regulator 61, 62, 63, 64 adjusts the pressure of the gas from each cylinder 21, 22, 23, 24 supplied via each cylinder valve 31, 32, 33, 34. .
[0062]
Each mass flow controller 11, 12, 13, 14 measures and adjusts the gas flow rate of each pressure-adjusted gas through which each gas flows in via each inflow valve 41, 42, 43, 44. .
[0063]
The outflow valves 51, 52, 53, 54 are valves for supplying necessary gas among the gas whose flow rate and pressure are adjusted to the downstream auxiliary valve 60.
[0064]
The mass flow controller 71 measures and adjusts the gas flow rate of the mixed gas composed of the gas from each cylinder, which is supplied via the auxiliary valve 60 after the gas supply is integrated from four systems to one system. is there.
[0065]
The mass flow controllers 72 and 73 are installed downstream of the mixed gas from the mass flow controller 71 divided into two systems. Each of the mass flow controllers 72 and 73 independently measures the gas flow rate of the mixed gas divided into the two systems and is the first. The mixed gas is supplied to the reaction vessel 111 while providing “fluctuation” by the gas flow rate change pattern as shown in the embodiment. The mass flow controllers 72 and 73 are controlled by a computer (not shown).
[0066]
In addition to the configuration of the gas supply unit 200 shown in FIG. 4B, for example, in the case of a rectangular wave flow rate change, a preset gas flow rate change pattern can be obtained by combining a number of electromagnetic valves and needle valves. Although it can be realized, for example, it is preferable to use a mass flow controller to realize a sinusoidal gas flow rate change pattern as shown in FIG. 3A shown in the first embodiment. In FIG. 4B, the mixed gas is supplied to the reaction vessel 111 after a single gas supply source 196 is branched in the mass flow controllers 72 and 73, but each of them is independently used by using a plurality of gas supply sources. Then, the gas flow rate may be controlled to supply the mixed gas to the reaction vessel 111.
[0067]
Next, the exhaust unit 198 will be described.
[0068]
The exhaust unit 198 includes an exhaust device (not shown) such as a vacuum pump for reducing the pressure in the gas supply unit 200 and the reaction vessel 111, and a main exhaust valve 118 provided between the reaction vessel 111 and the exhaust device. And a vacuum gauge 119 for measuring the vacuum pressure in the reaction vessel 111 and a reaction vessel leak valve 117.
[0069]
Next, the high frequency power supply unit 199 will be described.
[0070]
The high frequency power supply unit 199 includes an RF power supply 116 and a high frequency matching box 115. In the present embodiment, the RF power source 116 generates desired RF power having a frequency of 13.56 [MHz]. This RF power is supplied into the reaction vessel 111 via the high frequency matching box 115 and causes glow discharge.
[0071]
Next, a procedure for forming a deposited film using the deposited film manufacturing apparatus 100 of the present embodiment will be described below.
[0072]
First, a cylindrical substrate 112 is installed in a reaction vessel 111 that also serves as a cathode electrode, and the reaction vessel 111 is evacuated by an unillustrated exhaust device such as a vacuum pump. Subsequently, the temperature of the cylindrical substrate 112 is controlled to a predetermined temperature of 200 ° C. to 350 ° C. by the substrate heating heater 113.
[0073]
Next, the main exhaust valve 118 is opened to exhaust the inside of the reaction vessel 111 and the gas supply unit 200. Reading of vacuum gauge 119 is about 1 × 10 ^-2 When the pressure reaches [Pa], the auxiliary valve 60 is closed.
[0074]
Thereafter, the cylinder valves 31, 32, 33, 34 of the cylinders 21, 22, 23, 24 are opened, and each gas pressure is set to 2 [kg / cm] by the pressure regulators 61, 62, 63, 64. ² ] To adjust. Next, the respective inflow valves 41, 42, 43, 44 are gradually opened to introduce the respective gases into the respective mass flow controllers 11, 12, 13, 14.
[0075]
After the preparation for film deposition is completed as described above, each layer is formed according to the following procedure.
[0076]
When the cylindrical base body 112 reaches a predetermined temperature, the desired one of the outflow valves 51, 52, 53, 54 and the auxiliary valve 60 are opened, and the gas is gradually flowed using the mass flow controller 71. At this time, half of the gas flow rate actually measured by the mass flow controller 71 is distributed to the two mass flow controllers 72 and 73, respectively, and the reaction vessel 111 passes through the first gas pipe 114a and the second gas pipe 114b, respectively. To supply gas. Next, each gas flow controller 11, 12, 13, 14 is adjusted so that each gas has a predetermined mixing ratio and gas flow rate. At that time, the pressure in the reaction vessel 111 is 1.5 × 10 5. ² The opening of the main exhaust valve 118 is adjusted while looking at the vacuum gauge 119 so that the predetermined pressure is equal to or lower than [Pa]. The gas flow rate of the gas supplied from the first gas pipe 114a and the second gas pipe 114b is supplied while giving the “fluctuation” described in the first embodiment and the present embodiment by the mass flow controllers 72 and 73. . When the internal pressure is stabilized, the RF power source 116 having a frequency of 13.56 [MHz] is set to a desired power, and RF power is applied to the reaction vessel 111 through the high-frequency matching box 115 to cause glow discharge. The gas supplied into the reaction vessel 111 is decomposed by this discharge energy, and a predetermined functional deposition film is formed on the cylindrical substrate 112. After the formation of the deposited film having a desired film thickness, the supply of RF power is stopped, the outflow valve is closed to stop the gas flow into the reaction vessel, and the formation of the deposited film is completed. By repeating the same operation a plurality of times, it is possible to form a functional deposited film having a multilayer structure.
[0077]
Furthermore, it goes without saying that the type of gas and the operation of each valve are changed according to the formation conditions of each film and each layer.
[0078]
As described above, according to the present embodiment, when a deposited film is formed, gas fluctuation can be prevented by giving “fluctuation” to the gas flow rate. Thereby, similarly to the first embodiment, this embodiment can form a deposited film having substantially no characteristic unevenness. Further, since the suppression of the development of gas retention is performed not by the accuracy control of the mechanical characteristics of the first gas pipe 114a and the second gas pipe 114b, but by the “fluctuation” in the supply of each gas, the accuracy control is performed. Is reduced.
[0079]
Although the present invention has been described by taking the first and second embodiments as examples, the present invention is not limited to these. Examples of the first and second embodiments will be described below, but the present invention is not limited to these examples.
[0080]
【Example】
First, examples of the first embodiment of the present invention will be described below. (First embodiment)
In this example, the parallel plate type deposited film manufacturing apparatus 10 of the first embodiment shown in FIG. 1 is used as the deposited film manufacturing apparatus, and three types of a-Si: H deposited films are formed on the substrate 8. did.
[0081]
The distance between the cathode 6 and the ground electrode 7 is 5 [cm], and the gas pipes 3 a and 3 b are connected to the substrate 8 for the first gas supply path 1 and the second gas supply path 2, respectively. They are formed in parallel directions. Therefore, the gas is discharged in a direction parallel to the substrate 8.
[0082]
Further, a 12-inch Si wafer and a 12-inch square glass plate were used as the substrate 8, and a high frequency of 13.56 [MHz] was applied as a plasma forming power from a power source (not shown).
[0083]
Note that the detailed description of the deposited film manufacturing apparatus 10 has already been described above, and is therefore omitted.
[0084]
Next, Table 1 shows the conditions for forming the deposited film of this example.
[0085]
[Table 1]

When converted from the pressure and gas flow rate at this time, the average residence time of the gas was about 0.4 seconds.
[0086]
In this example, three types of samples were produced using three gas flow rate change patterns as shown in FIGS. 5 (a) to 5 (c).
[0087]
As shown in FIG. 5 (a), sample (1) is a so-called gas having a constant gas flow rate and a time in which the gas flow rate changes in a rectangular waveform with respect to the gas flow rate for the fixed time. “Fluctuation” is given, and a deposited film is formed with a period T of 4 seconds and T2 of 0.4 seconds. The gas flow rate change Δf was 20% of the flow rate at time T1.
[0088]
Sample {circle around (2)} is a sample for comparison with sample {circle around (1)}, and as shown in FIG. 5B, the gas flow rate is constant and a deposited film is formed.
[0089]
Sample (3) is also a sample for comparison with sample (1), and as shown in FIG. 5 (c), T = T2 = 0.4 seconds, and the deposited film is assumed to have a constant gas flow rate. Formed. The gas flow rate change Δf was set to 20%, which is the same as the gas flow rate change Δf at time T2 of the sample (1).
[0090]
In sample (1), the gas flow rate change Δf was set to 20% of the flow rate at time T1, and in sample (3), the gas flow rate change at T2 of sample (1) was the same.
[0091]
About each produced sample, the bonding state was measured on the wafer, the film thickness and the conductivity were measured on the glass at the measurement points shown below, and the variation was evaluated. The measurement points are eight points immediately below the first gas supply path 1 and the second gas supply path 2, and eight points between the first gas supply path 1 and the second gas supply path 2. A total of 16 locations.
[0092]
First, a 1 cm square region was cut out with the measurement point as the center, and the film thickness was measured using an ultraviolet / visible light absorption spectrometer. Next, SiH and SiH by infrared absorption spectroscopy ₂ The peak due to each is obtained, and the area ratio of both (SiH ₂ / SiH) was calculated. Finally, comb-shaped electrodes were formed on the deposited film on the glass substrate by vacuum evaporation, and the conductivity of the deposited film was measured.
[0093]
The measurement results of this example are shown in Table 2.
[0094]
[Table 2]

Table 1 shows the film thickness, SiH ₂ / SiH ratio and dark conductivity measurement results were evaluated for variation from 16 data points, then the standard deviation was calculated, and the relative value with the standard deviation value of sample (2) with a constant gas flow rate as 1. It is represented by
[0095]
Regarding the small variation in film thickness, the results of the samples (1) and (3) using the gas flow rate change pattern having the time T2 when the gas flow rate changes were good.
[0096]
SiH ₂ Regarding the standard deviation of the / SiH ratio and dark conductivity, sample (1) was the best and sample (3) was the worst. This gives moderate “fluctuation” to the gas supplied by the method of sample (1), while in the sample (3), the gas flow is disturbed too much, and the difference is the unevenness of dark conductivity. It is thought that it has appeared.
[0097]
Based on the above results, it is possible to improve the characteristic unevenness of the deposited film by the method of manufacturing a functional deposited film in which the gas to be supplied has an appropriate “fluctuation” and the gas flow rate is changed complementarily in a plurality of groups. I understood. In that case, the effect of the present invention cannot be obtained only by constantly changing the gas flow rate, and both the time for keeping the gas flow rate constant and the time for changing the gas flow rate are indispensable. It has been found for the first time that the effects of the present invention can be obtained.
[0098]
(Second embodiment)
In this embodiment, the deposited film manufacturing apparatus 10 shown in the first embodiment is used as an apparatus for forming a deposited film. In addition, an a-Si: H deposited film was formed under the conditions shown in Table 1 on a 12-inch Si wafer and a 12-inch square glass substrate equivalent to the substrate 8 described in the first embodiment.
[0099]
As a gas flow rate change pattern, as shown in FIG. 6, a sine wave-like gas flow rate change is given where “fluctuation” occurs, and the gas flow rate change Δf is set to 1%, 5%, 30%, The measurement was performed with five gas flow rate change patterns of 60% and 80%. The period T was 8 seconds, and the time T2 was 2 seconds. For comparison, a sample with a constant gas flow rate was also formed.
[0100]
About the obtained sample, film thickness, SiH ₂ The / SiH ratio and conductivity were obtained at 16 measurement points similar to those in the first example, and the variation of each measurement value was evaluated.
[0101]
The measurement results of this example are shown in Table 3.
[0102]
[Table 3]

In Table 3, the standard deviation for a sample with a constant gas flow rate is set to 1, and is expressed by relative evaluation.
[0103]
When the gas flow rate change Δf is 1%, the effect is seen compared to the case where the gas flow rate is constant, but the difference is small, whereas the gas flow rate change Δf is 5% to 60%. % Range, film thickness, SiH ₂ A remarkable improvement effect was observed with respect to all of the / SiH ratio and conductivity. On the other hand, when the gas flow change Δf is 80%, the film thickness, SiH ₂ Although the variation of the / SiH ratio and conductivity was improved, the values approached the values at a constant flow rate. From this result, it was confirmed that the effects of the present invention can be obtained to the maximum when the gas flow change Δf is in the range of 5% to 60%.
[0104]
(Third embodiment)
Also in this example, the deposited film manufacturing apparatus 10 shown in the first example was used as an apparatus for forming a deposited film. In addition, an a-Si: H deposited film was formed under the conditions shown in Table 1 on a 12-inch Si wafer and a 12-inch square glass substrate equivalent to the substrate 8 described in the first embodiment.
[0105]
As the gas flow rate change pattern, as shown in FIG. 7, a pulse-like gas flow rate change is given where “fluctuation” occurs, and the time ratio T2 / T1 of time T2 to time T1 is 0.5%, 1%, The deposited film was manufactured with five types of gas flow rate change patterns of 15%, 30%, and 40%. The gas flow change Δf was 30%, and the period T was 10 seconds. For comparison, a sample with a constant gas flow rate was also formed.
[0106]
About the obtained sample, film thickness, SiH ₂ The / SiH ratio and conductivity were obtained at 16 measurement points similar to those in the first example, and the variation of each measurement value was evaluated.
[0107]
The measurement results of this example are shown in Table 4.
[0108]
[Table 4]

In Table 4, the standard deviation by a sample with a constant gas flow rate is set to 1, and is expressed by relative evaluation.
[0109]
When the time ratio T2 / T1 was 0.5%, although the effect was seen compared with the case where the gas flow rate was constant, the difference was small. This is presumably because the gas does not follow because the time for changing the flow rate is too short, and the effect of the “fluctuation” of the gas is not sufficiently exhibited. On the other hand, when the time ratio T2 / T1 is in the range of 1% to 30%, the film thickness, SiH ₂ A remarkable improvement effect was observed with respect to all of the / SiH ratio and conductivity. Further, even when the gas flow rate change Δf is changed at a rate of 40%, the time ratio T2 / T1 is 1 to 30%. ₂ It was found that the standard deviation was good in all of the / SiH ratio and dark conductivity. From this result, it was confirmed that the effect of the present invention was maximally obtained when the time ratio T2 / T1 was in the range of 1% to 30%.
[0110]
(Fourth embodiment)
Also in this example, the deposited film manufacturing apparatus 10 shown in the first example was used as an apparatus for forming a deposited film. In addition, an a-Si: H deposited film was formed under the conditions shown in Table 1 on a 12-inch Si wafer and a 12-inch square glass substrate equivalent to the substrate 8 described in the first embodiment.
[0111]
As the gas flow rate change pattern, as shown in FIG. 8, a change in the gas flow rate in a rectangular wave shape is given where “fluctuation” occurs, and the period T is averaged based on the average residence time s [sec] in the gas reaction vessel. The deposited film was manufactured with six kinds of gas flow rate change patterns that are 0.5, 1, 10, 100, and 200 times the residence time s. The gas flow rate change Δf was 40%, and the time ratio T2 / T1 was 20%. For comparison, a sample with a constant gas flow rate was also formed.
[0112]
About the obtained sample, film thickness, SiH ₂ The / SiH ratio and conductivity were obtained at 16 measurement points similar to those in the first example, and the variation of each measurement value was evaluated.
[0113]
Table 5 shows the measurement results of this example.
[0114]
[Table 5]

In Table 5, the standard deviation of a sample with a constant gas flow rate is set to 1, and is expressed by relative evaluation.
[0115]
When the period T is in the range of 0.5 to 100 times the average residence time s, the film thickness, SiH ₂ A remarkable effect was observed for all of the / SiH ratio and conductivity. On the other hand, when the gas is changed at a period T of 200 times the average residence time s, the effect is seen, but the film thickness, SiH ₂ The / SiH ratio and dark conductivity both approached the values at a constant flow rate. This is considered as follows. When the period T is 200 times the average stay time s, the time T1 with a constant flow rate is sufficiently longer than the average stay time, and the contribution of the constant flow rate may become large, so that the optimum effect could not be obtained. Conceivable. From this result, it was confirmed that the effect of the present invention can be obtained to the maximum when the period T is in the range of 0.5 to 100 times the average stay time s when the gas flow rate of the present invention is changed.
[0116]
(Fifth embodiment)
Also in this embodiment, as the apparatus for forming the deposited film, an apparatus basically equivalent to the deposited film manufacturing apparatus 10 shown in the first embodiment was used. That is, the direction of the discharge holes of the gas pipes 3a and 3b in the deposited film manufacturing apparatus 10 used in the first embodiment is formed in a direction parallel to the substrate 8, whereas in this embodiment, it will be described later. As described above, the angle of the direction of the discharge hole of the gas pipes 3a and 3b is changed to form a deposited film, but all other points are the same as the deposited film manufacturing apparatus 10 used in the first embodiment. It is.
[0117]
The substrate on which the deposited film is formed is equivalent to the substrate 8 described in the first embodiment. The a-Si: H deposited film is formed on a 12-inch Si wafer and a 12-inch square glass substrate under the conditions shown in Table 1. Formed.
[0118]
As the first gas supply path 1 and the second gas supply path 2 to be used, as shown in FIG. 9A to FIG. 9F, the cathode with respect to the plane parallel to the substrate in the gas discharge direction. 10 degrees, 20 degrees, and 30 degrees on the side (FIGS. 9A to 9C) and an angle on the substrate side (FIGS. 9D to 9F) )) And a total of 6 types were used. As the gas flow rate change pattern, the period T was 6 seconds, the time T2 was 1 second, and the gas flow rate change Δf was 35%. For comparison, a deposited film was produced at a constant flow rate.
[0119]
About the obtained sample, film thickness, SiH ₂ The / SiH ratio and conductivity were obtained at 16 measurement points similar to those in the first example, and the variation of each measurement value was evaluated. Further, in this experimental example, in addition to the above examination, the number of spherical protrusions was estimated from a micrograph, and compared with the number of spherical protrusions obtained from a sample with a constant gas flow rate, and indicated as a relative value.
[0120]
The measurement results of this example are shown in Table 6.
[0121]
[Table 6]

In Table 6, the standard deviation by a sample with a constant gas flow rate is set to 1, and is expressed by relative evaluation.
[0122]
In all samples, the results showed that there was less variation compared to the sample with a constant gas flow rate, but the number of spherical protrusions was almost the same as that with a constant gas flow rate of 30 degrees. On the other hand, the number of spherical protrusions was reduced for those at 10 and 20 degrees.
[0123]
From this result, it was confirmed that the effect of the present invention can be obtained to the maximum when the angle of the gas discharge direction with respect to the plane parallel to the substrate surface is in the range of ± 20 degrees.
[0124]
As described above, the first to fifth examples have been described as examples of the first embodiment of the present invention. Hereinafter, examples of the second embodiment of the present invention will be described.
[0125]
(Sixth embodiment)
In the first to fifth embodiments, a parallel plate type deposited film manufacturing apparatus was used. However, in this embodiment, a deposited film was formed on a substrate using a cylindrical coaxial plasma CVD apparatus, and the following tests were performed. And the formed deposited film was evaluated.
[0126]
FIG. 10A and FIG. 10B show a cross-sectional top view of the reaction vessel 411 of the deposited film manufacturing apparatus 400 and a schematic configuration diagram of the deposited film manufacturing apparatus 400 used in this example. The deposited film manufacturing apparatus 400 has a cylindrical shape, and three first gas pipes 414a, second gas pipes 414b, and third gas pipes 414c are alternately arranged on the inner circumference one by one (total) 9) and a reaction vessel 411 on which a cylindrical substrate 412 which is an aluminum cylinder having a mirror finish of 80 mm in diameter is placed. In addition, a first gas pipe mass flow controller 421a, a second gas pipe mass flow controller 421b, which supply gas flows from the gas supply source 496 to the first to third gas pipes 414a, 414b, and 414c independently, and A third gas pipe mass flow controller 411c, an exhaust device (not shown) for reducing the pressure in the reaction vessel 411, and a high-frequency power supply unit 499 for causing glow discharge in the reaction vessel 411. The gas discharge direction from the first to third gas pipes 414a, 414b, 414c is angled from the plane parallel to the tangent to the surface of the cylindrical substrate 412 to the wall surface side of the reaction vessel 411. Thus, gas is discharged in the left and right directions.
[0127]
FIG. 11 shows a gas flow rate change pattern of the gas supplied from each gas pipe. Since the average residence time s of the gas in the reaction vessel 411 in the deposited film manufacturing apparatus 400 is about 1 second in the gas pressure and gas flow rate in the present embodiment, the period T is 20 seconds and the time T2 is as follows. Was 3 seconds. The gas flow rate was set to a gas flow rate obtained by dividing the total gas flow rate into three at time T1, and the gas flow change Δf was set to 25%.
[0128]
Table 7 shows the conditions for producing the electrophotographic photosensitive member in this example.
[0129]
[Table 7]

As shown in Table 7, SiH _Four And CH _Four The flow rate of was varied with time during the formation of the surface layer.
[0130]
As described above, when the film thickness of the photoconductor produced under the conditions shown in Table 7 was measured, the uniformity was improved as compared with the case where the gas flow rate was constant in the same apparatus. Next, when this photoconductor was set in an electrophotographic apparatus (Canon NP-6550) modified for experiment and the potential characteristics were evaluated, both the circumferential variation in sensitivity and the circumferential variation in charging ability were good. Thus, the unevenness was reduced as compared with the photoconductor produced with a constant gas flow rate.
[0131]
The produced photoreceptor was positively charged and image evaluation was performed. The presence or absence of image defects was examined in detail using a copy document of full black, full white and full halftone, but no image defects were found.
[0132]
(Seventh embodiment)
In this example, the deposition film manufacturing apparatus 100 of the second embodiment shown in FIGS. 4A and 4B, which is a cylindrical coaxial plasma CVD apparatus, is used as the deposition film manufacturing apparatus. Then, a deposited film was formed on the substrate, the following test was performed, and the formed deposited film was evaluated.
[0133]
In the deposited film manufacturing apparatus 400 used in the sixth embodiment described above, each gas pipe is divided into three groups of three, and gas is supplied by a total of nine gas pipes. As the deposited film manufacturing apparatus 100 of the example, one having four first gas pipes 114a and two second gas pipes 114b alternately arranged (a total of eight) was used. Accordingly, the mass flow controller that supplies the gas to the first and second gas pipes 114a and 114b while independently controlling the gas flow rate of the gas from the gas supply source 196 is also the first gas pipe mass flow controller. Two, 121a and a second gas pipe mass flow controller 121b, were used. The gas discharge direction from the first and second gas pipes 114a and 114b is angled from the plane parallel to the tangent to the surface of the cylindrical substrate 112 to the wall surface side of the reaction vessel 111 by 10 degrees. The gas is discharged in the left and right directions.
[0134]
Note that the detailed description of the deposited film manufacturing apparatus 100 is omitted because it has already been described above.
[0135]
A cylindrical substrate 112 made of an aluminum cylinder having a mirror finish of 108 mm in diameter is set in the deposited film manufacturing apparatus 100 having the above-described configuration, and an electron consisting of a charge injection blocking layer, a photoconductive layer, and a surface layer is formed on the surface. A photographic photoreceptor was prepared. The photoconductive layer was separated into two, and a function-separated type photoconductor was completed by providing a region mainly generating charges and a region mainly responsible for charge transport.
[0136]
Next, a gas flow rate change pattern in the present embodiment is shown in FIG. The average residence time s of the gas in the deposited film manufacturing apparatus 100 is about 1 second in the internal gas pressure and gas flow rate of this embodiment, so that the period T is 15 seconds and the time T2 is 2 seconds. . The gas flow rate was set to a gas flow rate obtained by dividing the total gas flow rate into two at time T1, and the gas flow change Δf was set to 20%.
[0137]
Table 8 shows the conditions for producing the electrophotographic photosensitive member in this example.
[0138]
[Table 8]

As shown in Table 8, SiH _Four And CH _Four The flow rate of was varied with time during the formation of the surface layer.
[0139]
As described above, when the film thickness of the photoconductor manufactured under the conditions shown in Table 8 was measured, the uniformity was improved as compared with the case where the gas supply was made constant with the same apparatus. Next, this photoconductor was set in an electrophotographic apparatus modified for experiment (modified based on Canon NP-6085 to perform image exposure with a semiconductor laser having a wavelength of 680 nm), and evaluation of potential characteristics was performed. Went. In a copying machine that performs exposure using a laser, it is particularly necessary to suppress the sensitivity of light potential and non-uniformity of halftone potential. However, the photoconductor produced in this example has unevenness compared to the photoconductor produced at a constant flow rate. Decreased and very good results were obtained.
[0140]
The produced photoreceptor was positively charged and image evaluation was performed. The presence or absence of image defects was examined in detail using a copy document of full black, full white and full halftone, but no image defects were found.
[0141]
【The invention's effect】
As described above, according to the present invention, the gas supply process includes a plurality of gas supply paths that independently control the gas flow rate and includes a variable supply process that varies with time. “Fluctuation” occurs during the supply, which can suppress the development of gas stagnation in the vacuum vessel. Therefore, a functional deposited film in which the characteristic unevenness is suppressed is produced without being affected by the retention. Further, since the sum of the gas flow rates of the gas supplied from each gas supply path in the variable supply step is substantially the same as the sum of the gas flow rates in the constant supply step, the gas flow rate necessary for forming the desired functional deposition film Is secured.
[0142]
Furthermore, since the suppression of the development of gas stagnation is performed by “fluctuation” in the supply of each gas, not by the accuracy control of the mechanical characteristics of the gas supply means, the accuracy control is reduced.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a deposited film manufacturing apparatus which is an example of a first embodiment of the present invention.
FIG. 2 is a graph for explaining a rectangular wave-like gas flow rate change pattern.
FIG. 3 is a graph for explaining another gas flow rate change pattern.
FIG. 4 is a top cross-sectional view and schematic configuration diagram of a deposited film manufacturing apparatus which is an example of a second embodiment of the present invention.
FIG. 5 is a graph showing a gas flow rate change pattern of gas supplied from each gas supply path used in the first embodiment of the present invention.
FIG. 6 is a graph showing a gas flow rate change pattern of gas supplied from each gas supply path used in the second embodiment of the present invention.
FIG. 7 is a graph showing a gas flow rate change pattern of gas supplied from each gas supply path used in the third embodiment of the present invention.
FIG. 8 is a graph showing a gas flow rate change pattern of gas supplied from each gas supply path used in the fourth embodiment of the present invention.
FIG. 9 is a schematic diagram showing the discharge direction of gas from each gas pipe, which was tried in the fifth embodiment of the present invention.
FIG. 10 is a top cross-sectional view and schematic configuration diagram of a deposited film manufacturing apparatus used in a sixth embodiment of the present invention.
FIG. 11 is a graph showing a gas flow rate change pattern of gas supplied from each gas pipe used in the sixth embodiment of the present invention.
FIG. 12 is a graph showing a gas flow rate change pattern of gas supplied from each gas pipe used in the seventh embodiment of the present invention.
FIG. 13 is a diagram for explaining retention of gas generated in a deposited film manufacturing apparatus as an example of the prior art.
[Explanation of symbols]
1 First gas supply path
1a First gas flow control unit
2 Second gas supply path
2a Second gas flow rate controller
3a, 3b gas pipe
4a, 4b Gas supply means
5 High frequency power supply
6 Cathode
7 Ground electrode
8 Board
9 Reaction vessel
10 Deposited film manufacturing equipment
11, 12, 13, 14, 71, 72, 73 Mass flow controller
21, 22, 23, 24
31, 32, 33, 34 Cylinder valve
41, 42, 43, 44 Inlet valve
51, 52, 53, 54 Outflow valve
60 Auxiliary valve
61, 62, 63, 64 Pressure regulator
100, 400 Deposition equipment
111, 411 reaction vessel
112, 412 Cylindrical substrate
113 Substrate heating heater
114a, 414a first gas pipe
114b, 414b second gas pipe
414c third gas pipe
115 matching box
116 high frequency power supply
117 Reaction vessel leak valve
118 Main exhaust valve
119 Vacuum gauge
197 Deposited film formation part
198 Exhaust section
199, 499 High frequency power supply
200 Gas supply unit
421a first mass flow controller
421b Second mass flow controller
421c Third mass flow controller
496 Gas supply source

Claims (17)

A gas supply step of supplying a gas as a raw material for the functional deposition film from a gas supply path into a vacuum container in which a substrate on which a functional deposition film is to be formed is placed; and plasma is generated in the vacuum container In a method for producing a functional deposited film including a plasma generation step to be generated,
The gas supply step supplies the gas from a plurality of gas supply paths, and
A constant supply step in which the gas flow rate from each of the gas supply paths is constant;
A variable supply step of changing the gas flow rate with respect to the gas flow rate of the constant supply step so that the sum of the gas flow rates from the gas supply paths is substantially the same as the sum of the gas flow rates of the constant supply step. A method for producing a functional deposited film, comprising: The method for producing a functional deposited film according to claim 1, wherein the variable supply step includes a step of continuously changing the gas flow rate over time. The method for producing a functional deposited film according to claim 1, wherein the constant supply step and the variable supply step are alternately repeated. And the peak value of the gas flow from the gas supply passage in the variation supplying step, the difference between the gas flow rate from the gas supply path in the constant supply step, the gas flow rate from the respective gas supply path in the constant supply step The method for producing a functional deposited film according to any one of claims 1 to 3, wherein the content is 5% or more and 60% or less. 5. The method for producing a functional deposited film according to claim 1, wherein a time required for the variable supply step is 1% to 30% of a time required for the constant supply step. 6. The variable supply step and the constant supply step are periodically repeated, and the cycle is
s = pV / f
s: average residence time of gas in the vacuum vessel V: internal volume in the vacuum vessel p: pressure during the plasma generation process f: 0 of the average residence time s expressed by the flow rate of gas supplied into the vacuum vessel The method for producing a functional deposited film according to any one of claims 1 to 5, wherein the method is 5 times or more and 100 times or less. In the gas supply step, each gas is discharged from the plurality of gas supply paths in a range of ± 20 degrees with respect to an imaginary plane parallel to the surface of the base body, whereby the gas is supplied into the vacuum container. The method for producing a functional deposited film according to claim 1, comprising a step of supplying each gas. A gas supply step of supplying a gas as a raw material for the functional deposition film from a gas supply path into a vacuum container in which a substrate on which a functional deposition film is to be formed is placed; and plasma is generated in the vacuum container In a method for producing a functional deposited film including a plasma generation step to be generated,
The gas supply step supplies the gas from a plurality of gas supply paths, and
A constant supply step of making the gas flow rate from each gas supply path constant at a desired amount;
The gas flow rate from each gas supply path is the constant supply so that the sum of the gas flow rates from the gas supply paths is substantially the same as the sum of the gas flow rates from the gas supply paths in the constant supply step. And a variable supply step of changing the flow rate of the gas from each gas supply path of the process. A vacuum container in which a substrate on which a functional deposition film is to be formed is placed; a gas supply means for supplying a gas as a raw material for the functional deposition film; and a plasma means for generating plasma in the vacuum container; In a functional deposition film manufacturing apparatus having
The gas supply means comprises at least one gas source and a plurality of gas supply paths for supplying gas from the gas source into the vacuum vessel,
The gas is supplied so that the sum of the gas flow rate from each gas supply means and the gas flow rate from each gas supply means is substantially the same as the sum of the gas flow rates from the gas supply means. A plurality of gas flow rate control means for controlling each gas flow rate of each of the gas supply means by a gas flow rate change pattern comprising a variable supply time for changing the flow rate with respect to the gas flow rate of the constant supply time. Functional deposition film manufacturing equipment. The functional deposition film manufacturing apparatus according to claim 9, wherein the gas is a mixed gas composed of a plurality of types of gases. 11. The functional deposition film manufacturing apparatus according to claim 9, wherein each of the gas flow rate control units continuously changes the gas flow rate over time during the variable supply time. The functional deposition film according to any one of claims 9 to 11, wherein the gas flow rate change pattern by each gas flow rate control means is such that the constant supply time and the variable supply time are alternately repeated. Manufacturing equipment. And the peak value of the gas flow from the gas supply means in the variation supply time, the difference between the gas flow rate from the gas supply means in the predetermined feed time, the gas flow rate from the respective gas supply means in the predetermined feed time The apparatus for producing a functional deposited film according to claim 9, wherein the apparatus is 5% or more and 60% or less. The functional deposition film manufacturing apparatus according to claim 9, wherein the variable supply time is 1% or more and 30% or less of the constant supply time. The variable supply time and the constant supply time are periodically repeated, and the cycle is
s = pV / f
s: Average residence time of gas in the vacuum vessel V: Inner volume in the vacuum vessel p: Pressure at the time of plasma generation f: 0 of the average residence time s expressed by the flow rate of gas supplied into the vacuum vessel The apparatus for producing a functional deposited film according to any one of claims 9 to 14, wherein the apparatus is 5 times or more and 100 times or less. The gas supply means includes a plurality of gas pipes in which discharge holes for discharging the gas into the vacuum container are formed in a range of ± 20 degrees with respect to a virtual plane parallel to the surface of the base. The functional deposition film manufacturing apparatus according to any one of claims 9 to 15. A vacuum container in which a substrate on which a functional deposition film is to be formed is placed; a gas supply means for supplying a gas as a raw material for the functional deposition film; and a plasma means for generating plasma in the vacuum container; In a functional deposition film manufacturing apparatus having
The gas supply means comprises at least one gas source and a plurality of gas supply paths for supplying gas from the gas source into the vacuum vessel,
The sum of the gas flow rate from each gas supply means and the gas flow rate from each gas supply path of the constant supply time is the sum of the gas flow rate from each gas supply unit and the gas flow rate from each gas supply unit. By a gas flow rate change pattern consisting of a variable supply time for changing the gas flow rate from each gas supply path with respect to the gas flow rate from each gas supply path for the constant supply time so as to be substantially the same as the sum, An apparatus for producing a functional deposition film, comprising a plurality of gas flow rate control means for controlling the gas flow rates of the gas supply means.

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