JP2004004695A - Alignment film formation method for liquid crystal panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface processing method or the like through which reliability of wiring is improved, resistance is reduced, the entire device is simply constituted, the size of the device is made small, materials to be processed are safely and locally processed, the processing cost is reduced and the processing capability is increased. <P>SOLUTION: Gas electric discharge is conducted in discharging gas that includes at least oxygen in atmospheric pressure or in the vicinity of the atmospheric pressure and a metallic oxide film 9 is formed on the surface of a metallic film 7 on a substrate 6 by gas activating species generated by the electric discharge. When the electric discharge gas includes at least hydrogen or organic materials, a metallic oxide film 13 such as a transparent electrode on the surface of a substrate 11 is exposed to the gas activating species so as to conduct reducing. Moreover, by conducting gas discharge on the surface of liquid, surface processing is performed for the liquid itself and/or a surface processing is conducted for the substrate or the like using the liquid. Furthermore, by applying the gas activating species generated by the gas discharge along a slanted direction, an alignment film is formed on a liquid crystal glass substrate. <P>COPYRIGHT: (C)2004,JPO

Description

【００５７】
表１において、液体の流量は、その液体を気化させた場合のガスとしての流量を示している。また、気体放電に際して少なくとも水素または有機物がガスまたは液体として供給されるようになっている。一般に還元を行なう場合には、被処理材の表面に重合物が形成されないことが好ましい。この表１から判るように、放電用ガスに酸素を混合すると、重合を抑制することができるが、還元性も小さくなる。また、水分を加えることによって、還元性に影響を与えることなく、重合を抑制できることが判る。
【００５８】
図７には、本発明による方法に使用される表面処理装置の別の実施例が示されている。この表面処理装置２２は、電源２３に接続された棒状の電極２４が、下向きに開放された箱形をなす金属カバー２５の中心に、絶縁取付具２６によって電気的に浮いた状態で垂直に保持されている。金属カバー２５は、接地されると共に、その内部に電極２４を完全に収容し、かつその下端部２７が、電極２４の先端近傍まで延長して、その下方に開口２８を画定している。この下端部２７が電極２４の対電極となる。金属カバー２５内部は、放電用ガスを供給するガス供給装置２９に連通している。開口２８には、金属メッシュ３０が配設され、かつその下方に表面処理しようとする基板の被処理材が配置される。
【００５９】
ガス供給装置２９から所定の放電用ガスを供給し、金属カバー２５内部を前記放電用ガスで置換する。電源２３から電極２４に電圧を印加すると、電極２４の先端と金属カバー下端部２７との間で気体放電が生じる。ガス供給装置２９から金属カバー２５内には連続的に放電用ガスが供給されているので、放電領域３１に生成されたガス活性種は、前記放電用ガスと共に反応性ガス流３２となって開口２８から下方へ噴出される。この反応性ガス流に含まれる前記ガス活性種によって、前記基板が表面処理される。このとき、反応性ガス流３２は、前記放電により発生したイオンが金属メッシュ３０によりトラップされてニュートライズされるので、表面処理される前記基板に与えるダメージをより少なくすることができる。
【００６０】
また、別の実施例では、金属カバー２５の下端開口２８に例えばフレキシブルチューブなどの管路を接続し、その先端に設けたノズルから反応性ガス流を噴出させることができる。表面処理しようとする前記基板は、表面処理装置２２本体とは別個の位置に配置され、前記管路を介して前記反応性ガス流に曝露される。これにより、被処理材である基板の形状や寸法などの処理条件に応じて、ガス流の流量やノズルの形状等を変えて処理を行なうことができるので、必要に応じた処理能力の調整が可能であり、また作業性を向上させることができる。
【００６１】
図８には、本発明による表面処理方法の別の実施例に使用するための表面処理装置が示されている。この表面処理装置３３は、電源３４に接続されかつ水平に配置された平板状の電極３５を有する。電極３５の下側には、所定の液体３６を貯溜する容器３７が配置され、かつ放電用ガスを供給するためのガス供給装置３８が、そのガス噴出口３９を電極３５と液体３６の液面との間に画定される狭い空間に向けて配置されている。容器３７の底部には、電極３５の対電極となる接地された金属板４０が、電極３５に対応する位置に平行に配設されている。表面処理される被処理材４１は、液体３６中に浸漬して容器３７の底に、金属板４０に対応する位置に載置される。
【００６２】
上述した各実施例の場合と同様に、ガス供給装置３８のガス噴出口３９から所定の放電用ガスを噴出させて、電極３５と液体３６の液面間の前記空間を前記放電用ガスで置換する。次に電源３４から電極３５に電圧を印加すると、電極３５と前記液面との間で気体放電が発生する。この放電領域４２には、プラズマによる前記放電用ガスの活性種が生成され、該活性種が液体３６中に混入して、被処理材４１を表面処理する。
【００６３】
放電用ガスとして酸素を含むガス、例えばヘリウムと酸素との混合ガスを用いた場合には、前記気体放電により放電領域４２には酸素ラジカル、オゾンなどの活性種が生成される。液体３６が水、好適には純水の場合には、その中に前記オゾンが混入することによって液体３６がオゾン水となり、被処理材４１に対して過酸化水素水と同様の酸化分解力を発揮する。これに対し、実際に過酸化水素水を用いてウェット法により表面処理した場合には、過酸化水素水自体が高価なために処理コストが高くなり、しかも人体にとって有害であるため、取扱いに注意を要し、作業が面倒で複雑化する。本発明によれば、低コストで十分に高い酸化処理能力を得ることができ、かつ取扱いが簡単で作業性が向上する。
【００６４】
別の実施例では、放電用ガスとして、ＣＦ_４、Ｃ_２Ｆ_６、ＳＦ_６などのフッ素化合物を含むガスを使用することができる。この場合には、前記気体放電によってフッ素のイオン、励起種などの活性種が生成される。液体３６に水を用いると、前記フッ素イオンが水に混入して液体３６がフッ化水素（ＨＦ）水になるので、被処理材４１の表面をエッチングすることができる。これは、例えばシリコンウエハのウェットエッチングにおいて、その表面から酸化膜を除去するために使用することができる。
【００６５】
また、放電用ガスとして窒素を含むガス、例えば窒素の単体ガス、窒素とヘリウムとの混合ガス、圧縮空気などを使用することができる。液体３６を硫酸とした場合には、前記気体放電により窒素のイオン、励起種などの活性種が発生し、この窒素イオンが硫酸に混入して硫酸過水アンモニウムに変化させる。これにより、液体３６はアンモニア過水液と同等の洗浄能力が得られ、被処理材４１の表面に付着している有機物等を除去することができる。特に、この方法は、基板などに形成されたレジストをアッシング後にウェットエッチングする場合に適用すると効果的である。
【００６６】
本実施例の表面処理方法によれば、上述したように放電用ガスと液体３６とを適当に選択して組み合わせることによって、酸化・エッチング・洗浄等の様々な表面処理を、安価にかつ簡単に行うことができる。そして、被処理材を浸漬する前記液体の清浄度を一定の高いレベルに維持することによって、表面処理により発生する物質の汚染から被処理材を保護することができる。このような表面処理装置の変形実施例が図９に示されている。
【００６７】
図９の実施例では、液体３６を貯溜する容器３７の両端に、それぞれ該液体の注入口４３と排出口４４とが設けられ、これらを接続する循環管路４５の途中に純水再生装置４６が設けられている。容器３７内の液体３６は、排出口４４から循環管路４５を介して純水再生装置４６に送られ、被処理材４１の表面処理などにより生じる不純物イオンやダストを除去した後、注入口４３から容器３７内に戻される。従って、容器３７内の液体３６を常に高い清浄度に保持することができ、汚染の虞が解消されるだけでなく、表面処理作業の途中で液体３６を取り替える必要がなく、作業性及び生産性が向上する。純水再生装置４６は、従来使用されている公知の手段であり、活性炭、イオン交換樹脂、各種フィルタ等からなり、これらを適宜選択して、又は組み合わせて構成される。また、液体３６が純水以外の場合には、その液体の種類に対応したフィルタリング手段として構成されかつ使用される。
【００６８】
図１０には、同様に液体中で被処理材を表面処理するための表面処理装置の別の実施例が示されている。本実施例の表面処理装置４７は、電源４８に接続された電極４９と、その対電極である接地された電極５０とが、ケーシング５１内に一定の間隔をもって対向させて配置されている。ケーシング５１は、その一端において放電用ガスを供給するガス供給装置５２に接続され、かつ他端において、液体５３を貯溜する容器５４内の底部に配置された多孔板からなるノズル５５に接続されている。例えば基板である被処理材５６は、容器５４の液体５３中に浸漬して、ノズル５５の上方に配置される。本実施例では、図示されるように、容器５４の大きさに対応して、多数の被処理材５６が液体５３中に垂直に並列に配置されている。
【００６９】
ガス供給装置５２からケーシング５１内に放電用ガスを供給し、両電極４９、５０間の空間を前記放電用ガスで置換する。電源４８から電極４９に電圧を印加すると、前記両電極間の空間に気体放電が発生する。この放電領域５７において生成される前記放電用ガスの活性種は、ガス供給装置５２から放電用ガスが連続的に供給されることによって、反応性ガス流としてノズル５５に送給され、液体５３中に泡状となって噴出する。ノズル５５を容器５４の底部に配置することにより、前記反応性ガスの気泡が液体５３を撹拌する作用を果たし、その結果液体５３は前記ガス活性種がより均一に混入して、全体的に一様に表面処理することができる。また、前記反応性ガスの液体５３への溶解効率を増すためには、ノズル５５を構成する多孔板の穴径を細かくすればする程好都合である。
【００７０】
これにより、図８及び図９の実施例と同様に、放電用ガスの種類、及び液体５３に応じて被処理材５６を酸化、エッチング、洗浄などの表面処理をすることができる。しかも本実施例では、容器５４とガス活性種を生成させる放電部とを別個に離隔して設け、かつ適当な管路を介して接続するように構成したので、処理条件に応じて容器の大きさや放電用ガスの供給量等を調整することによって、一度に多数の被処理材、又は様々な形状寸法・大きさの被処理材を表面処理することができる。
【００７１】
図１１及び図１２には、図８及び図９の実施例の変形例がそれぞれ示されている。これらの変形実施例では、被処理材４１が容器３７の外に配置されている。図８及び図９の実施例と同様に、電極３５と液体３６表面との間で発生させた気体放電により、ガス供給装置３８から供給される放電用ガスの励起活性種を生成し、これを混入させた液体３６を被処理材４１に向けて配給し、栓５８で流量を制御しながら被処理材表面に流す。本発明によれば、液体３６及び前記放電用ガスの種類を適当に組み合わせることによって、同様に被処理材４１に酸化、エッチング、アッシング等の様々な表面処理を行うことができる。
【００７２】
特に図１２の実施例では、図９の実施例と同様に、液体３６を純水再生装置４６で再生処理しながら容器３７に循環させ、かつ前記励起活性種を混入させた液体３６を容器３７から被処理材４１に配給する。また、これらの変形例では、容器３７に純水を連続的に供給しまたは循環させて被処理材４１を表面処理しながら、その途中で栓５８を閉じ、かつガス供給装置３８から供給する放電用ガスの種類を変更して液体３６の性質を変化させた後、栓５８を再度開けることによって、被処理材４１に異なる表面処理を連続的に行うことができる。
【００７３】
このように図１１及び図１２の変形実施例によれば、気体放電を発生させる容器３７の外に被処理材４１を配置するので、その大きさや寸法・形状に対応して容器３７を変更する必要がなく、装置全体を小型化することができる。更に、その処理能力を要求される処理の規模に応じて容易に制御することができ、必要に応じて枚葉処理及びバッチ処理が可能であり、コストの低減化を図ることができる。
【００７４】
また図１３には、本発明による表面処理方法の別の実施例が示されている。本実施例では、液晶パネル用ガラス、ウエハ基板等の比較的大型の被処理材４１が洗浄槽５９内に配置され、その中に連続的に供給される純水を用いて洗浄処理される。洗浄槽５９から排出した使用後の純水は、容器３７に送られる。使用後の純水中には、被処理材４１から除去された有機物等が含まれ、容器３７の液面に浮遊している。容器３７の上方には、図１１、図１２の実施例と同様に、電源３４に接続された電極３５が液面との間に僅かな間隙をもって配置され、かつ容器３７の底部に接地された電極４０が配設されている。
【００７５】
電極３５と液体３６表面との間にガス供給装置３８から放電用ガスを供給しつつ気体放電を発生させ、これにより生成されるガス活性種を用いて液体３６表面を処理する。前記放電用ガスに圧縮空気、酸素とヘリウムまたは窒素との混合ガスを用いることによって、容器３７の液面に浮遊する前記有機物をアッシングして除去する。このように清浄化した純水は、洗浄槽５９に送られて被処理材４１の洗浄に再使用される。
【００７６】
このように本発明によれば、被処理材４１をその大きさ、形状、寸法に拘わらず、所望の位置に固定した状態で、純水を循環させつつ清浄化することによって連続的に洗浄することができるので、特に最近の液晶パネル用ガラス基板、ウエハの大型化に容易に対応することができ、かつ枚葉処理及びバッチ処理が可能である。また本発明によれば、純水以外の液体を用いて洗浄等の処理をする場合にも、使用後の液体を同様にアッシング処理を行うことによって、その清浄度を容易に回復し、再使用することができる。
【００７７】
図１４には、本発明による表面処理方法を適用した液晶表示装置の配向膜形成方法が記載されている。ＴＦＴ、ＭＩＭ（Ｍｅｔａｌ　Ｉｎｓｕｌａｔｏｒ　Ｍｅｔａｌ）、ＩＴＯ等の素子や電極パターン、またはカラーフィルタ等を形成した液晶パネルの対向基板６０の上面には、有機高分子樹脂などの合成樹脂被膜６１が塗布されている。基板６０の上方に、本発明の大気圧下でのプラズマによる表面処理方法を適用した配向処理装置６２が配置される。この配向処理装置は、電源６３に接続された電極６４と、その対電極として接地された電極６５とを有する。電源側の電極６４は、その全体がガラスまたはセラミック等の絶縁体６６によって被覆されている。絶縁体６６によって被覆された電極６４と電極６５とは、一定の間隔をもって対向し、かつ図示されるように基板６０及び合成樹脂被膜６１の表面に対してある角度ａをもって傾斜するように配置されている。角度ａは、０度＜ａ＜９０度の範囲内で適当に設定される。両電極６４、６５間に画定される空間は、放電用ガスを供給するガス供給装置６７に接続されている。
【００７８】
ガス供給装置６７から両電極６４、６５間の前記空間に放電用ガスを供給しつつ、電源６３から電極６４に電圧を印加すると、大気圧又はその近傍圧下の前記空間内で気体放電が発生する。この気体放電は、前記放電用ガスに活性種を生成させるものであれば、グロー放電、コロナ放電、アーク放電等いずれの放電であってもよい。電極６４が絶縁体６６で被覆されていることによって、前記両電極間における放電状態を均一にすることができる。このとき、電源側の電極６４ではなく接地側の電極６５を絶縁体で被覆しても良く、また両電極を絶縁体で被覆しても良い。
【００７９】
前記気体放電により放電領域６８に生成された放電用ガスの活性種は、ガス供給装置６７から連続的に供給される放電用ガスによって、反応性ガス流として合成樹脂被膜６１表面に角度ａをもって斜め上方から吹き付けられる。これにより、合成樹脂被膜６１の表面が、図１４において右方向に配向される。更に、基板６０を配向処理装置６２に対して相対的に前後左右方向に移動させることによって、合成樹脂被膜６１全面を均一に配向処理することができる。
【００８０】
図１５には、本発明によるラインタイプの配向処理装置の実施例が示されている。この配向処理装置６９は、ガス供給装置６７と、図１４の実施例と同様に電源電極及び接地電極を備えた放電発生部７０と、吹出ノズル７１とからなる。吹出ノズル７１はガラス、セラミック等の絶縁材料で形成され、所謂エアナイフのように直線上の狭幅の吹出口７２を、合成樹脂被膜６１を形成した基板６０の表面近傍にかつ該表面向けてある角度ａ（０度＜ａ＜９０度）をもって配置されている。
【００８１】
ガス供給装置６７から所定の放電用ガスを放電発生部７０に供給し、前記電源電極に電圧を印加することによって、大気圧又はその近傍の圧力下で前記放電用ガス中に気体放電を生じさせる。この気体放電によって、放電発生部７０内に生成された前記放電用ガスの活性種は、ガス供給装置６７から放電用ガスが連続的に送られることによって反応性ガス流となり、図１５Ａ、Ｂに示すように吹出ノズル７１の先端吹出口７２から、基板６０の合成樹脂被膜６１の表面にその全幅に亘って斜め上方から角度ａで噴射される。
【００８２】
これにより、合成樹脂被膜６１が図１４の実施例と同様に配向される。このとき、例えば７ｋｇ／ｃｍ^２程度の圧力で前記ガス流を強く噴射すればする程、より効果的にかつ迅速に配向処理することができるので好ましい。また、基板６０を配向処理装置６９に対して左右方向に相対移動させることによって、容易に被膜６１の全面を処理することができる。また、放電発生部７０と吹出ノズル７１とをフレキシブルチューブ等の適当な管路により接続することもできる。
【００８３】
放電用ガスのガス種としては、圧縮空気、窒素と酸素との混合ガス、又は酸素とヘリウムとの混合ガス等、少なくとも酸素を含むガスを使用する。この場合、前記気体放電によってオゾン、酸素ラジカル等の励起活性種が生成される。放電用ガスに圧縮空気、又は窒素と酸素との混合ガスを用いる場合、放電発生部７０の前記両電極間には、高電圧を印加する。このときの放電はコロナ放電である。放電用ガスにヘリウムと酸素との混合ガスを用いた場合には、例えば１３．５６ＭＨｚの高周波電源を使用し、グロー放電が発生する。
【００８４】
図１６には、本発明による液晶パネルの配向膜形成方法の別の実施例が示されている。この実施例では、配向処理される基板７３が、接地された金属板７４の上に載置され、かつその直ぐ上方に金属製の電極７５が配置される。電極７５は、図１５の実施例の吹出ノズル７１と同様のエアナイフ構造からなり、ガス供給装置６７に接続された通路７６と細長いスリット状の吹出口７７とを有する。
【００８５】
電極７５は、図１６に示すように基板７３に近接させて、かつその表面に対して吹出口７７から放電用ガスが斜め上方から噴出されるように配置される。ガス供給装置６７から所定の放電用ガスを通路７６内に供給し、かつ吹出口７７から基板表面に噴射させつつ、電極７５に前記電源から高周波電圧を印加する。金属板７４が電極７５の対電極となって、電極７５先端と基板７３との間で放電が発生する。この放電領域７８内では、前記放電用ガスの励起活性種が生成され、吹出口７７から連続的に噴出される放電用ガスにより基板７３表面に吹き付けられる。これにより、前記基板表面に所望の配向処理がなされる。
【００８６】
基板７３の表面に図１４、図１５の実施例のような合成樹脂被膜が予め形成されている場合には、ヘリウムと酸素との混合ガスを使用する。この場合、上述した実施例と同様にオゾン、酸素ラジカル等の励起活性種が生成されて、前記合成樹脂被膜がアッシングと同じ表面処理により配向処理される。
このように本発明によれば、非接触で配向処理を行なうことができるので、合成樹脂被膜の表面を損傷したり剥離させたりする虞がなく、しかも均一な配向付与が可能となる。また、配向膜の角度の制御は、主に前記反応性ガスを吹き付ける角度に依存し、更に部分的には電極への印加電圧、放電用ガスのガス種に依存するので、比較的容易に制御することができる。
【００８７】
別の実施例では、放電用ガスが常温で液体の適当な有機物を含むように選択することによって、基板表面に配向膜を直接形成することができる。例えば、ヘリウムにデカン（Ｃ_１０Ｈ_２２）を加えた場合、又はヘリウムにシリコーンを加えた場合には、それぞれ樹脂膜が、所望の配向方向に重合することによって基板７３表面に形成される。また、ヘリウムに酸素とシリコーンとを加えた場合には、酸化ケイ素（ＳｉＯ_２）の膜が形成される。
【００８８】
図１７には、基板上に配向膜を直接形成するための図１６の変形例が示されている。この変形例では、放電用ガスが吹出口７７から基板７３に対して略直角に吹き付けられるように、電極７５が垂直に配置されている。基板７３は、放電と同時に左右いずれかの方向に電極７５と相対的に移動させる。これにより、基板の移動速度を成膜速度に合せて適当に設定することによって樹脂膜は斜めに成長させることができ、所望の配向膜が得られる。
【００８９】
次に、実施例を用いて本発明による液晶パネルの配向膜形成方法を具体的に説明する。
（実施例１）
配線パターンが形成されているＭＩＭ基板８０表面のポリイミド被膜を、図１８に示すスポットタイプの表面処理装置８１を用いて、以下の条件で配向処理した。表面処理装置８１は、二重構造をなす石英管８２の中心に電極８３を配置して制御回路８４を介して電源８５に接続し、石英管８２の外側に配置した接地電極８６との間で放電させた。石英管８２内部には、外部から放電用ガスを連続的に供給し、放電領域８７に生成される前記ガスの活性種を含むガス流をガス噴出口８８から基板８０表面に対して噴出させた。基板８０は、前記ガス流に対して斜めに、θ＝１０〜３０度の角度で配置した。
使用ガス：　圧縮空気
ガス圧　：　３〜７Ｋｇ／ｃｍ^２
使用電力：　１００〜２００Ｗ
処理時間：　２０分
【００９０】
このように配向処理した基板８０と従来のラビング処理により配向膜を形成した基板との間に液晶を挟み、かつその両側に偏光板を配設して光を照射することにより配向状態を観察した。その結果、前記ガス流を当てた前記ポリイミド被膜の部分が、該ガス流の向きに配向されていた。
【００９１】
（実施例２）
同様に配線パターンを設けたＭＩＭ基板８０表面のポリイミド被膜を、図１９Ａ、Ｂに示されるラインタイプの表面処理装置８９を用いて、以下の条件で配向処理した。表面処理装置８９は、電源８５に接続された電源９０の底面にその長手方向に沿って細長いガス吹出口９１が開設され、その直ぐ下方を水平に搬送される基板８０表面に放電用ガスを噴出させつつ、前記ポリイミド被膜を直接放電に曝露させた。

【００９２】
実施例１と同様にして前記ポリイミド被膜の配向状態を観察したところ、基板全面に亘って良好に配向されていた。
【００９３】
（実施例３）
同様に配線パターンを設けたＭＩＭ基板８０表面のポリイミド被膜を、図２０Ａ、Ｂに示すスポットタイプの表面処理装置９２を用いて、以下の条件で配向処理した。表面処理装置９２は、電源電極９３と接地電極９４との間に細長いガラス管９５を挟装し、その一端から他端に向けて放電用ガスを流しながら、前記両電極間で放電を発生させた。基板８０は、ガラス管９５の前記他端付近に、該他端開口から噴出するガス流に対して斜めに、θ＝１０〜３０度の角度で配置した。

【００９４】
実施例１と同様にして前記ポリイミド被膜の配向状態を観察したところ、処理時間１分及び３分で配向されていることが確認された。この実施例の場合には、基板８０が直接放電に曝露されないので、基板にチャージアップの虞がなく、かつ処理速度が比較的遅いので、配向処理をより容易に制御することができる。
上記実施例１〜３のいずれの場合にも、使用した放電用ガスの種類から、基板８０のポリイミド被膜に対してアッシングと同じ表面処理によって配向処理が行われたものと考えられる。
【００９５】
（実施例４）
配線パターンを形成していないパイレックスガラス基板９６の表面に、図２１に示す表面処理装置を用いて、以下の条件で配向膜を直接形成した。この表面処理装置は、図１６の実施例と同様の構成を有し、電源電極７５と接地電極７４上のガラス基板９６との間で直接放電させる。放電用ガスは、容器９８内の常温で液体の有機物９９を、ガス供給装置９７から送られるガスに制御弁１００、１０１により適当に調整して混入させ、電極７５内部の通路７６を介してガス吹出口７７から基板９６表面に斜めに噴出させることにより、ガラス基板表面に有機物９９の重合膜１０２を形成した。電極７５と基板９６表面との間隙は１ｍｍ、基板９６に対する電極７５の傾斜角度は、θ＝６０度であった。
使用ガス　：　ヘリウム
ガス流量　：　２０リットル／分
液体有機物：　ＯＨ−変成シリコーン、シリコーンオイル、ｎ−デカン
使用電力　：　１５０Ｗ
【００９６】
重合膜１０２を形成した２枚の基板９６間に液晶を挟んで同様に配向状態を観察したところ、重合膜１０２のガス吹出口７７に近い部分１０３は、配向されていなかったが、ガス吹出口７７から遠い部分１０２が配向されていた。
【００９７】
（実施例５）
実施例４と同じガラス基板９６の表面に以下の条件で配向膜を直接形成した。、図２２に示すように、接地電極７４上に配置したガラス基板９６表面と電源電極１０５との間で直接放電させ、かつガス吹出口１０６から放電領域に横方向から放電用ガスを噴出させた。前記放電用ガスには、実施例４と同じものを使用し、前記基板表面に重合膜１０２が形成された。
使用ガス　：　ヘリウム
ガス流量　：　２０リットル／分
液体有機物：　ＯＨ−変成シリコーン、シリコーンオイル、ｎ−デカン
使用電力　：　１５０Ｗ
【００９８】
重合膜１０２は、実施例４と同様に、ガス吹出口１０６に近い部分１０３は配向されていなかったが、遠い部分１０４は配向されていた。
【００９９】
（実施例６）
実施例４と同じガラス基板９６の表面に、図２３に示す表面処理装置を用いて、以下の条件で配向膜を直接形成した。この表面処理装置は、実施例４と同様に常温で液体の有機物９９を混入させた放電用ガスを誘電体１０７内部に供給し、該誘電体内部の電源電極１０８と外部の接地電極１０９との間で放電を発生させ、該放電による前記ガスの活性種を含むガス流をガス吹出口１１０からガラス基板９６表面に斜めに６０度の角度で噴射して、その全面に亘って重合膜１１１を形成した。この重合膜は、液晶のプレチルト角が９０度であり、配向されていなかった。
使用ガス　：　ヘリウム
ガス流量　：　２０リットル／分
液体有機物：　ＯＨ−変成シリコーン
使用電力　：　１５０Ｗ
【０１００】
次に、図２４に示すように、接地電極１１２上に載置したガラス基板９６を水平に搬送しながら、電源電極１１３との間で直接放電させた。ガス供給装置１１４から放電用ガスとして、ぬれ性向上の表面処理によく使用されるヘリウム、窒素、圧縮空気等を供給した。この結果、基板９６全面において重合膜１１１が良好に配向された。
【０１０１】
（実施例７）
配線パターンを設けたＭＩＭ基板を用いて、実施例６と同一の実験を行った。前記基板表面には、実施例と同様に良好に配向された重合膜が形成された。
【０１０２】
以上、本発明の好適な実施例について詳細に説明したが、本発明は、その技術的範囲内において、上記実施例に様々な変形・変更を加えて実施することができる。例えば、図１及び図７の表面処理装置においても、図１４の実施例と同様に電極を絶縁体又は誘電材料で被覆し、より均一な放電を発生させると共に、放電による電極の損耗、及びそれにより生成される物質による被処理材の汚染を防止することができる。また、表面処理装置の電極を平板状に形成しかつ垂直に配置することによって、その長手方向に直線上に放電を発生させる、所謂ラインタイプの表面処理装置として用いることができる。また、表面処理装置の電極構造として、上記実施例のもの以外に、例えば本願出願人による特願平５−１１３２０４号明細書に記載されるような、誘電体材料で形成されたガス流路内に放電用ガスを導入し、その外部に配置した電極に高周波電圧を印加して、前記ガス流路内に大気圧近傍の圧力下で気体放電を発生させ、それにより生成されるガス活性種を利用して表面処理する構造のものも、同様に使用することができる。
【０１０３】
【発明の効果】
本発明の基板の表面処理方法によれば、基板表面の金属層を容易にかつ高速で、該基板の他の部分、例えば電子部品等にダメージを与えることなく酸化させて、その表面に金属酸化物の被膜を形成することができるので、基板上に形成された配線や電極等の腐食を有効に防止して、電子回路の信頼性を向上させ、かつ寿命を長くすることができる。
【０１０４】
この表面処理方法を利用することによって、本発明の多層配線基板の形成方法によれば、第１の金属配線の表面が金属酸化物により被覆されて耐食性を有するので、第２の金属配線をエッチングする際に下側の第１の金属配線までエッチングされる虞がなく、それらの間に形成される層間絶縁膜を、その本来の絶縁機能以上に不必要に厚く形成する必要がなくなり、薄くすることができるので、その成膜に要する時間が短縮されかつコストが低減して、生産性の向上を図ることができると共に、基板の薄型化に対応することができる。
【０１０５】
また、本発明の基板の表面処理方法によれば、基板表面の金属酸化物の層を容易にかつ高速で、該基板の他の部分、例えば電子部品等にダメージを与えることなく還元して金属化することができるので、この金属酸化物層がＩＴＯ等の透明電極の場合には、その膜厚を薄くして所望の透明度を維持しつつ、低抵抗化を図ることにより所望の電気的性能を確保することができる。
【０１０６】
更に、本発明の表面処理方法によれば、使用する液体及び放電用ガスを適当に選択することによって、該液体に例えば、過酸化水素水、アンモニア過水液等と同程度の酸化、エッチング、洗浄等の表面処理能力を安価に付与し、又は洗浄等の表面処理に用いた液体自体を簡単に清浄化して安価に再使用することができ、コストの低減を図ることができると共に、取扱いが比較的容易で安全なため、作業性が大幅に向上する。特に液体に対する放電と該液体を用いた被処理材の表面処理とを別個に行うことによって、被処理材の寸法・形状や場所に拘らず表面処理が行われ、必要に応じて枚葉処理・バッチ処理が可能となり、被処理材に対して異なる表面処理を連続して行うことができ、装置の小型化及び処理能力の向上が図られる。そして、かかる表面処理方法は、請求項１０記載の表面処理装置のように構成することによって、比較的簡単な構成により低コストで実現することができる。
【０１０７】
また、本発明の表面処理方法によれば、気体放電を生じさせる部分と被処理材を表面処理する部分とを別個の位置に設け、これらを接続してガス活性種を含むガスを液体に供給し、かつこれを被処理材に用いて表面処理することができるので、処理条件、例えば処理目的、被処理材の形状・寸法や一度に処理すべき個数等、または気体放電に使用するガスの種類や放電させる環境等に応じた表面処理が可能で、処理能力を適当に調整することができる。また、目的、用途に応じて枚葉処理・バッチ処理を使い分けすることもでき、放電用ガスの取扱い等処理作業が比較的容易かつ安全であり、生産性の向上を図ることができる。そして、かかる表面処理方法は、比較的簡単な構成により低コストで実現することができる。
【０１０８】
本発明の液晶パネルの配向膜形成方法によれば、ガス活性種を含むガス流を基板表面に斜めに噴射することによって、基板表面の合成樹脂被膜に非接触で配向処理ができ、又は、基板表面に直接配向膜を形成できるので、従来のように配向膜を損傷したり剥離する虞れがなく、歩留りが向上すると共に、処理時間が短くかつ枚葉処理が可能なため、生産性が大幅に向上し、コストの低減を図ることができる。
【図面の簡単な説明】
【図１】本発明による基板の表面処理方法に使用される表面処理装置の構成を概略的に示す図である。
【図２】Ａ図及びＢ図からなり、本発明による基板の表面処理方法を用いて多層配線を形成する工程を示す図である。
【図３】本発明により還元処理を行なうガラス基板を示す平面図である。
【図４】本発明による還元処理において放電用ガスに水蒸気または有機物の気化ガスを含ませるための構成を示すブロック図である。
【図５】図４と異なる別の構成を示すブロック図である。
【図６】図４と更に異なる別の実施例を示すブロック図である。
【図７】本発明の表面処理方法に使用する表面処理装置の別の実施例を示す図である。
【図８】図７とは別の表面処理方法の実施例に使用する表面処理装置を示す図である。
【図９】図８の変形例を示す図である。
【図１０】図７とは更に別の実施例に使用する表面処理装置を示す図である。
【図１１】図８の別の変形例を示す図である。
【図１２】図９の変形例を示す図である。
【図１３】本発明による表面処理方法の別の実施例を示す図である。
【図１４】本発明による表面処理方法を用いて液晶パネルの配向膜形成方法を説明するための図である。
【図１５】図Ａは、ラインタイプの配向処理装置の実施例を概略的に示す側面図、図Ｂはその上面図である。
【図１６】図１５と異なる配向処理装置の実施例を示す図である。
【図１７】図１６の実施例の変形例を示す図である。
【図１８】スポットタイプの表面処理装置を用いた液晶パネルの配向処理方法を示す図である。
【図１９】図Ａは、液晶パネルの配向処理方法に使用するラインタイプの表面処理装置を示す側面図、図Ｂはその部分断面図である。
【図２０】図Ａは、同じく液晶パネルの配向処理方法に使用するスポットタイプの表面処理装置を示す側面図、図Ｂはその端面図である。
【図２１】本発明による液晶パネルの配向膜形成方法を概略的に示す図である。
【図２２】図２１の変形例を示す図である。
【図２３】本発明による液晶パネルの配向膜形成方法の別の実施例において、その前半の工程を示す図である。
【図２４】図２３の実施例における後半の工程を示す図である。
【符号の説明】
１　表面処理装置，２　電源，３　電極，４　空間，５　ガス供給装置，６　基板，７　金属配線，８　放電領域，９　金属酸化膜，１０　ＳｉＯ_２層，１１　金属膜，１２　ガラス基板，１３　透明電極，１４　表示領域，１５　管路，１６　バルブ，１７　タンク，１８　水または液状有機物，１９　ヒータ，２０　噴霧装置，２１　管路，２２　表面処理装置，２３　電源，２４　電極，２５　金属カバー，２６　絶縁取付具，２７　下端部，２８　開口，２９　ガス供給装置，３０　金属メッシュ，３１　放電領域，３２　反応性ガス流，３３　表面処理装置，３４　電源，３５　電極，３６　液体，３７　容器，３８　ガス供給装置，３９　ガス噴出口，４０　金属板，４１　被処理材，４２　放電領域，４３注入口，４４　排出口，４５　循環管路，４６　純水再生装置，４７　表面処理装置，４８　電源，４９、５０　電極，５１　ケーシング，５２　ガス供給装置，５３　液体，５４　容器，５５　ノズル，５６　被処理材，５７　放電領域，５８　栓，５９　洗浄槽，６０　基板，６１　合成樹脂被膜，６２　配向処理装置，６３　電源，６４、６５　電極，６６　絶縁体，６７　ガス供給装置，６８　放電領域，６９　配向処理装置，７０　放電発生部，７１　吹出ノズル，７２　先端吹出口，７３　基板，７４　金属板，７５　電極，７６　通路，７７　吹出口，７８　放電領域，８０　ＭＩＭ基板，８１　表面処理装置，８２　石英管，８３　電極，８４　制御回路，８５　電源，８６　接地電極，８７　放電領域，８８　ガス噴出口，８９　表面処理装置，９０　電源，９１　ガス吹出口，９２　表面処理装置，９３　電源電極，９４　接地電極，９５　ガラス管，９６ガラス基板，９７　ガス供給装置，９８　容器，９９　有機物，１００、１０１　制御弁，１０２　重合膜，１０３、１０４　部分，１０５　電源電極，１０６　ガス吹出口，１０７　誘電体，１０８　電源電極，１０９　接地電極，１１０　ガス吹出口，１１１　重合膜，１１２　接地電極，１１３　電源電極，１１４　ガス供給装置[0001]
[Industrial applications]
The present invention relates to a technology for oxidizing and reducing the surface of a material to be treated, removing or cleaning organic and inorganic substances, and various other surface treatments, and particularly relates to a semiconductor component such as an IC, a circuit substrate, and a surface of a liquid crystal substrate. The present invention also relates to a method and an apparatus for surface-treating wires, electrodes and the like formed on the surface.
[0002]
[Prior art]
Conventionally, various surface treatment techniques have been used in the field of manufacturing semiconductor devices. For example, when removing organic substances such as flux residues used for soldering, a wet cleaning method using an organic solvent or a dry cleaning method that removes organic substances by irradiating them with ozone and ultraviolet rays to cause a chemical reaction. There is. In the case of the wet method, the cleaning agent may affect electronic components and the like, and in the case of the dry method, the ability to remove organic substances having a large molecular weight is particularly low, and a sufficient cleaning effect cannot be expected. Therefore, recently, a method of performing a surface treatment using plasma generated in a vacuum has been developed.
[0003]
For example, Japanese Patent Application Laid-Open No. 58-147143 discloses a method in which the surface of a lead frame is treated with an oxygen gas activated by microwave discharge under a reduced pressure environment to improve the adhesion to a resin. Japanese Patent Application Laid-Open No. 4-16837 discloses a method in which hydrogen gas of 1 to 10 Torr is introduced into a plasma etching apparatus and a discharge is performed to remove oxides. A method is described in which a high frequency voltage is applied to an electrode to generate argon oxygen plasma or hydrogen reduction plasma to etch a lead frame.
[0004]
However, when plasma discharge is generated in a vacuum or reduced-pressure environment, special equipment such as a vacuum chamber and a vacuum pump is required, and the entire apparatus becomes large-sized, complicated, and expensive. In addition, since it is necessary to decompress and maintain the inside of the chamber at the time of discharge, the processing itself takes a long time, and the workability is troublesome, but the processing capacity is low, and the productivity is reduced. Furthermore, plasma discharge in vacuum or under reduced pressure may cause thermal or electrical damage due to more electrons and ions than excited species, and may cause significant damage or damage to parts other than the part to be processed. Will have an effect.
[0005]
On the other hand, recently, a method has been proposed in which various surface treatments such as ashing and etching are performed by generating plasma using a rare gas and a small amount of a reaction gas under atmospheric pressure. In many cases, a discharge is directly generated between a high-frequency electrode and a material to be processed. For example, Japanese Patent Application Laid-Open No. 4-334543 discloses that a plasma is generated inside a tube, A method of treating a flowing material passing through the inner surface or inside of a pipe is disclosed. Also, as in the surface treatment apparatus described in JP-A-3-219082, a discharge is caused between a power supply electrode and a ground electrode, and the plasma activation is performed. There is also known a method in which a seed is sprayed on a material to be processed to form a film.
[0006]
[Problems to be solved by the invention]
2. Description of the Related Art In recent years, in accordance with demands for high performance and miniaturization of semiconductor devices, IC components and circuit boards using multilayer wiring have been widely used. When a multilayer wiring is formed on a substrate, first, a metal wiring such as aluminum is patterned and formed on the substrate by using a photolithography technique, and an insulating film such as SiO ₂ is coated thereon. A metal layer serving as a second wiring is formed on the insulating film, and the metal layer is etched into a desired wiring pattern by using the same photolithography technique. However, since pinholes are easily generated in the SiO ₂ film, when the metal layer formed on the SiO ₂ film is patterned, there is a possibility that the metal wiring below the metal layer is simultaneously etched. For this reason, a method is generally employed in which a SiO ₂ film is used as an insulating layer and is formed thicker than the required film thickness. However, a great deal of time and labor is required for the formation of the SiO ₂ film, the cost is increased, the productivity is reduced, and the substrate itself is very thick, and the size of the substrate and electronic components is reduced and thinned. There was a problem that was contrary to the request of.
[0007]
Further, a liquid crystal display (LCD) generally uses a glass substrate using a transparent electrode made of ITO or the like. In particular, in the case of a liquid crystal display element used for a word processor, a personal computer, or the like, a relatively large current flows during driving, so that the wiring resistance of the transparent electrode is required to be low. For this reason, a method of increasing the thickness of the transparent electrode has conventionally been adopted. However, since the ITO electrode is generally formed by a vacuum film forming method or the like, the film forming time is long and the cost is increased. However, there is a problem that as the thickness increases, the transparency decreases, which affects the liquid crystal display function itself.
[0008]
In order to solve these problems, the inventor of the present application has proposed that if the surface of the lower metal wiring is coated in advance with an oxide, even if pinholes exist in the SiO ₂ film formed thereon, Attention was paid to the fact that, by patterning the metal wiring, the lower metal wiring was not etched. Furthermore, even for metal wirings and electrodes exposed on the substrate surface, if the surface is coated with a metal oxide, corrosion resistance against various contaminations can be imparted, and the reliability of the wirings and the like is improved, and Life can be extended. In addition, the inventor of the present application achieved a desired reduction in resistance without reducing the thickness of the transparent electrode more than necessary by reducing and metallizing the ITO electrode, which is a metal oxide. We focused on the points to gain. However, in any case, the above-mentioned conventional surface treatment technology has various practical difficulties.
[0009]
Further, in the production of liquid crystal display devices, in order to form an alignment film on the surface of a conventional liquid crystal panel, conventionally, a method for forming an alignment film on a liquid crystal panel includes, for example, a heat-resistant synthetic resin film having electrical insulation properties such as polyimide. A method of forming an orientation on a substrate and rubbing the surface with a cloth-wound roller in one direction, that is, performing rubbing treatment, is employed. However, such a physical rubbing method has problems such as peeling of the synthetic resin film from the substrate, and damage to the film surface due to cloth wrapped around the rollers or dust adhering to the film surface. Was. In addition, the uniformity of the alignment is important, but in the conventional method, the angle of the alignment film and the tilt of the liquid crystal molecules largely rely on experience and trial and error, and the variation is actually large. Pass / fail cannot be determined for the result. Furthermore, it was impossible to control the angle of the alignment film.
[0010]
Therefore, the substrate surface treatment method of the present invention has been made in view of the above-described conventional problems, and has as its object the purpose of thermally reducing metal wirings and electrodes formed on the surface of the substrate. Or, by performing a surface treatment easily without causing electrical damage, it is possible to improve the reliability of the wiring by imparting corrosion resistance as needed, or to reduce the resistance, and furthermore, a vacuum or No special equipment for decompression is required, the whole apparatus can be easily configured and miniaturized, and the material to be processed can be processed safely and locally. To provide a high surface treatment method.
[0011]
Furthermore, an object of the present invention is to provide a multilayer wiring board which can achieve a thinning of a board without making an interlayer insulating film unnecessarily thick by using such a surface treatment method, and which is easy, low-cost and highly reliable. It is to provide a method that can be formed.
[0012]
Another object of the present invention is to provide a relatively simple structure that does not require any special equipment for vacuum or decompression, so that not only oxidation and reduction but also various surfaces such as etching, removal of organic and inorganic substances, cleaning, etc. It is an object of the present invention to provide a surface treatment method capable of performing treatment easily and effectively at low cost, and capable of performing single-wafer treatment or batch treatment as required, and an apparatus for realizing the same.
[0013]
Still another object of the present invention is to provide an alignment film for a liquid crystal panel which can provide uniform alignment without damaging or peeling the surface of a synthetic resin film by non-contact processing, particularly in the production of a liquid crystal display device. It is to provide a forming method. It is another object of the present invention to provide a method capable of directly forming an alignment film on a substrate surface of a liquid crystal panel.
[0014]
[Means for Solving the Problems]
In one aspect, the method for treating a surface of a substrate according to the present invention includes generating a gas discharge in a gas containing at least oxygen under atmospheric pressure or a pressure near the atmospheric pressure, and applying a gas active species generated by the discharge to a substrate surface. The method is characterized in that the formed metal film is exposed, thereby oxidizing the surface of the metal layer.
[0015]
Therefore, by generating a gas discharge at a pressure near the atmospheric pressure with a relatively simple configuration, oxygen radicals, oxygen active species such as ozone are generated, and the action oxidizes the metal layer on the substrate surface, thereby The surface can be coated with a metal oxide.
[0016]
In another aspect, a method of forming a multilayer wiring board according to the present invention includes the steps of: covering a first metal wiring formed on a substrate surface with an insulating film formed thereon, and forming a metal film on the insulating film; In the step of patterning the second metal wiring by etching and etching the same, before forming an insulating film on the first metal wiring, a gas discharge is generated in the gas at or near atmospheric pressure. And exposing the first metal wiring to gas active species generated by the discharge.
[0017]
Using this surface treatment method, the surface of the first metal wiring is covered with a metal oxide, so that the second metal wiring can be patterned even if a pinhole is formed in the insulating film formed thereon. In this case, even the first metal wiring can be prevented from being etched.
[0018]
Furthermore, in one aspect, the method for treating a surface of a substrate according to the present invention includes the steps of: generating a gas discharge in a gas containing at least hydrogen or an organic substance under atmospheric pressure or a pressure close to the atmospheric pressure; And exposing the metal oxide layer formed on the substrate surface to thereby reduce the metal oxide layer.
[0019]
By generating a gas discharge at a pressure close to the atmospheric pressure with such a relatively simple configuration, hydrogen radicals are generated, or organic substances are dissociated, ionized, and excited, and ionic excited species of organic substances, carbon, hydrogen, etc. Are generated, and by their action, the metal oxide layer on the substrate surface can be reduced and metallized.
[0020]
In one embodiment, the gas generating the gas discharge further includes water vapor. By including water vapor in the gas that causes gas discharge, the speed of the reduction treatment by the gas active species can be increased.
[0021]
Another embodiment is characterized in that an organic substance is previously applied to the surface of the substrate, and the dissociation, ionization and excitation of the organic substance by gas discharge can be effectively performed. Further, the present invention is characterized in that a vaporized organic substance is added to a gas for generating a gas discharge, and similarly, its dissociation, ionization and excitation are promoted, and the effect of the reduction treatment can be enhanced.
[0022]
Further, in one aspect, the surface treatment method of the present invention is characterized in that a gas discharge is generated in a predetermined gas near or at the surface of a liquid under atmospheric pressure or a pressure in the vicinity thereof.
[0023]
Thus, the surface of the liquid is treated by the action of the gas containing the active species generated by the gas discharge under the pressure near the atmospheric pressure, or the gas is mixed into the liquid, and the liquid itself has a surface treatment capacity. Can be given.
[0024]
In one embodiment, the material to be treated is surface-treated by using the liquid after the gas discharge is generated, and the material to be treated is immersed in the liquid. Due to the surface treatment capability imparted to the liquid, the material to be treated can be surface-treated without causing thermal or electrical damage regardless of the position where the discharge occurs, and the material to be treated can be directly surface-treated by the liquid. Can be processed.
[0025]
In another aspect, the surface treatment apparatus of the present invention comprises: a container for liquid; means for generating a gas discharge in a predetermined gas at or near atmospheric pressure at a liquid level in the container; And means for supplying the gas in the vicinity of the liquid level of the container.
[0026]
Thereby, the gas active species generated by the plasma generated under the pressure near the atmospheric pressure acts on the liquid in the container, and the liquid itself is treated, or the material to be treated is surface-treated through the liquid. can do.
[0027]
In one embodiment, the apparatus further comprises a means for circulating and cleaning the liquid from the container. By removing impurity ions and dust generated in the liquid by the surface treatment, the cleanliness of the liquid can be kept high.
[0028]
In another embodiment, the workpiece is immersed in the liquid of the container, and the workpiece can be directly surface treated in such liquid. Still another embodiment is characterized in that it has means for distributing the liquid in the container toward the material to be processed, and the liquid to be processed is generated at a position different from the position where the gas discharge for generating the liquid is generated. The material can be surface treated.
[0029]
Furthermore, in one aspect, the surface treatment method of the present invention includes the steps of: causing a gas discharge to occur in a predetermined gas under atmospheric pressure or a pressure near the atmospheric pressure, and generating a gas containing a gas active species generated by the gas discharge. The method is characterized in that the material is supplied into a liquid and the material to be treated is surface-treated using the liquid.
[0030]
By using the liquid into which the gas containing the gas active species generated by the gas discharge is introduced, the material to be treated can be surface-treated by its action, and the material to be treated is separated from the position where the gas discharge occurs. , The processing capacity can be appropriately adjusted according to the shape, size and number of the material to be processed, the environment in which gas discharge is generated, and other processing conditions.
[0031]
In one embodiment, the material to be treated is immersed in the liquid. As a result, the material to be processed can be directly surface-treated.
[0032]
In another aspect, the surface treatment apparatus of the present invention includes a liquid container, a means for generating a gas discharge in a predetermined gas at or near atmospheric pressure, and a gas active species generated by the discharge. Means for supplying the contained gas into the liquid in the container.
[0033]
In this way, by separately providing the liquid container and the gas discharge generating means and connecting them by the gas supply means, the size, size, shape, and other various conditions of the material to be processed or as necessary, By controlling the type and amount of the gaseous active species supplied into the liquid, the supply method can be appropriately changed, and the size and shape of the liquid container can be changed.
[0034]
In one embodiment, in addition to this, the material to be treated is immersed in the liquid in the container, or a means for distributing the liquid in the container toward the material to be treated is provided. Thus, the material to be treated can be directly surface-treated in such a liquid, and the material to be treated can be surface-treated at a desired position.
[0035]
Further, in one aspect, the method for forming an alignment film of a liquid crystal panel of the present invention includes generating a gas discharge in a predetermined gas under atmospheric pressure or a pressure near the atmospheric pressure, and includes a gas active species generated by the discharge. The method is characterized in that a gas flow is obliquely jetted toward a substrate surface of a liquid crystal panel in accordance with an orientation direction to be applied, thereby exposing gas active species to the substrate surface.
[0036]
By causing the gas active species to act obliquely on the substrate surface in this manner, an alignment film can be formed on the substrate surface in a non-contact manner in accordance with the direction of the gas flow.
[0037]
In one embodiment, in addition, a synthetic resin film serving as an alignment film is formed in advance on the substrate surface of the liquid crystal panel, and the synthetic resin film is exposed to gas active species. Thereby, the synthetic resin film on the substrate surface can be oriented in the direction of the gas flow.
[0038]
On the other hand, in another embodiment, a predetermined gas contains an organic substance that is liquid at room temperature, and after a film is formed on the substrate surface by its active species, a second gas discharge is generated under atmospheric pressure or a pressure in the vicinity thereof. And exposing the second gas active species generated thereby to the film forming surface of the substrate. As a result, the desired alignment film can be directly formed by polymerizing the organic substance on the substrate surface.
[0039]
In another aspect, the method for forming an alignment film of a liquid crystal panel according to the present invention includes generating a gas discharge under atmospheric pressure or a pressure near the atmospheric pressure, and exposing a predetermined gas containing a liquid organic substance at room temperature to the discharge. It is characterized in that the liquid crystal panel is jetted in the orientation direction to be applied toward the substrate surface, and a film is formed on the substrate surface by the active species of gas generated by the discharge.
[0040]
This makes it possible to relatively easily polymerize an organic substance on the substrate surface using plasma under atmospheric pressure to form a synthetic resin film, and to orient it in a desired direction without contact.
[0041]
【Example】
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 schematically shows an apparatus for use in the method for treating a surface of a substrate according to the present invention. The surface treatment apparatus 1 includes a pair of electrodes 3 connected to a power supply 2 and arranged vertically so as to face each other at a predetermined interval. A discharge gas is supplied from a gas supply device 5 to a space 4 defined between the two electrodes. Immediately below both electrodes 3, a substrate 6 for performing desired surface treatment is horizontally disposed. On the upper surface of the substrate 6, a metal wiring 7 made of aluminum is formed.
[0042]
The discharge gas is supplied from the gas supply device 5 to the space 4, and the atmosphere between the tip of both electrodes 3 and the substrate 6 and in the vicinity thereof is replaced with the discharge gas. When a predetermined voltage is applied from the power supply 2 to the electrodes 3, gas discharge occurs between the electrodes 3 and the substrate 6. In the discharge region 8, there are various reactions such as dissociation, ionization, and excitation of the discharge gas by plasma. The discharge is generated particularly strongly between the metal wiring 7 made of aluminum and formed on the upper surface of the substrate 6.
[0043]
In this embodiment, a mixed gas of helium and oxygen is used as the discharge gas. As a result, active species such as oxygen ions and excited species are generated in the discharge region 8. The surface of the metal wiring 7 is oxidized by exposure to these active species, and a thin metal oxide film 9 as shown in FIG. 2A is formed.
[0044]
Generally, when a high-frequency voltage is applied using a rare gas such as helium at or near atmospheric pressure, a gas discharge is easily generated and the discharge becomes uniform, thereby causing damage to the exposed workpiece. Can be reduced. Also, even if compressed air or a mixed gas of nitrogen and oxygen is used as the discharge gas, the metal wiring can be similarly oxidized. Also, since helium itself is expensive, manufacturing costs increase, so use a rare gas such as helium or argon only at the start of discharge, and change to a suitable inexpensive gas such as compressed air after discharge occurs. You can also.
[0045]
As for the temperature condition, the treatment can be performed at room temperature, so that a problem such as thermal damage does not occur to the elements and the like of the substrate. However, it goes without saying that it is better to heat the substrate only to increase the oxidation rate.
[0046]
As shown in FIG. 2B, the substrate 6 in which the surface of the metal wiring 7 is covered with the metal oxide film 9 has an insulating film 10 made of, for example, SiO ₂ having a predetermined thickness on the metal wiring 7. Form. Next, a metal film 11 of, for example, aluminum is deposited on the insulating film 10 and is etched using a photolithography technique in the same manner as in the related art to form a second-layer metal wiring in a desired wiring pattern. According to the present invention, since the surface of the lower metal wiring is oxidized and covered with the metal oxide as described above, the pin can be formed even if the interlayer insulating film is not formed thicker than necessary for electrical insulation. Irrespective of the presence or absence of the holes, there is no possibility that the lower metal wiring is etched when the upper metal wiring is etched. In this manner, a two-stage multilayer wiring can be formed on the substrate 6, and by repeating the above steps, a third-layer and fourth-layer multilayer wiring can be formed.
[0047]
In the present embodiment, the metal wiring 7 formed on the substrate 6 is made of aluminum. However, the present invention can be similarly applied to a wiring made of another metal such as copper or ITO. In addition, even if the wiring is not a multilayer wiring as in this embodiment, corrosion resistance can be imparted by treating the surface of the metal wiring or electrode exposed on the substrate surface as described above. However, the reliability can be improved and the life can be prolonged.
[0048]
FIG. 3 shows a glass substrate 12 to which the substrate surface treatment method according to the present invention is applied. The glass substrate 12 is for use in a liquid crystal display device, and has a surface on which a number of transparent electrodes 13 made of, for example, ITO are formed. In this embodiment, a gas containing at least hydrogen or an organic substance is supplied as a discharge gas using the surface treatment apparatus shown in FIG. Generates a discharge. By generating plasma in this way, when the discharge gas contains hydrogen, active species such as hydrogen ions and excited species are generated, and when the gas contains an organic substance, the organic substance is dissociated and ionized. When activated, active species such as organic substances, carbon, and hydrogen ion excited species are generated. These active species are exposed only to the portion of the transparent electrode 13 other than the display area 14 by, for example, arranging means such as a mask on the glass substrate 12.
[0049]
As described above, since the transparent electrode 13 is formed of a metal oxide such as ITO, it is reduced and metallized by the action of the active species. Thereby, the electrical resistance of the transparent electrode 13 can be reduced. Therefore, even if the film thickness is not formed unnecessarily thick as in the prior art, it is possible to secure the electrical performance required for the electrode while maintaining good transparency for use in a liquid crystal display device.
[0050]
Further, the organic substance for generating the active species does not necessarily need to be included in the discharge gas. In another embodiment, it can be pre-applied to the surface of the glass substrate 12. In this case, in the discharge region between the electrode 3 and the glass substrate 12, the gas is dissociated, ionized, and excited by the plasma to increase the energy state, so that the applied organic substance partially evaporates and Exposure to discharge causes dissociation, ionization, and excitation to generate active species in the same manner as described above. Further, another part of the organic material receives energy from the active species of the gas having a high energy state, thereby dissociating, ionizing, and exciting the active species such as organic substances, carbon, hydrogen ions, and excited species. It becomes. As a result, the same reducing action as in the case where the discharge gas contains an organic substance can be obtained. In still another embodiment, the organic substance can be supplied to the discharge region in a vaporized state using a separate gas supply means. In this case, the same operation and effect as described above can be obtained.
[0051]
When the discharge gas contains an organic substance, the organic substance may polymerize to form a polymer thin film on the surface of the material to be treated. When formation of such a polymer thin film is not preferable, it is convenient to use a gas containing a low molecular organic substance or to make the discharge gas contain moisture.
[0052]
FIGS. 4 to 6 show a specific configuration for causing the discharge gas to contain moisture or a low molecular organic substance. In the embodiment shown in FIG. 4, a bypass is provided in the middle of a pipe line 15 for supplying a discharge gas from the gas supply device 5 to the surface treatment device 1, and a branch is provided. Into the tank 17. Water (preferably pure water) or liquid organic matter 18 is stored in the tank 17, and a heater 19 makes it easy to generate steam or vaporized gas of the organic matter. The discharge gas introduced into the tank 17 is returned to the pipe 15 containing water vapor or a vaporized gas of the organic substance 18, mixed with the discharge gas directly supplied from the gas supply device 5, and subjected to surface treatment. It is supplied to the device 1. The amount of water vapor or organic matter mixed with the discharge gas is adjusted by adjusting the circuit of the valve 16 and the heater 19.
[0053]
In the embodiment shown in FIG. 5, a spraying device 20 is provided in the middle of a pipe 15 connected to the surface treatment device 1 from the gas supply device 5, and water or liquid organic matter 18 is supplied from a tank 17 to the spraying device 20. It is added to the discharge gas sent from the gas supply device 5 in an atomized state. Also in this case, by providing a heater similar to that shown in FIG. 4 in the tank 17 and heating it, it is possible to promote the atomization of water and liquid organic matter.
[0054]
In the embodiment shown in FIG. 6, water or liquid organic matter 18 stored in a tank 17 is heated by a heater 19 to generate steam or vaporized gas of the liquid organic matter, and a discharge gas supplied from a gas supply device 5. Is supplied directly to the surface treatment apparatus 1 or the discharge region 8 through a separate pipe 21. The pipe 21 can be connected in the middle of the pipe 15 connecting the gas supply device 5 and the surface treatment device 1, and it is also possible to mix a vaporized gas of water vapor or an organic substance with the discharge gas and supply it to the discharge region. .
[0055]
An experiment was conducted on the effect of reducing the material to be treated using the surface treatment method of the present invention, and the following results were obtained. As the discharge gas, only helium, a mixed gas of helium and propane, a mixed gas of helium and oxygen, and a mixed gas of helium and hydrogen were used. Regarding water vapor or an organic substance to be added to the discharge gas, three kinds were performed: adding decane (C ₁₀ H ₂₂ ), adding decane and water, and adding nothing. The power supply voltage for generating gas discharge was 200 W. The flow rate of helium was 20 liters per minute. The results obtained from this experiment are shown in Table 1 below.
[0056]
[Table 1]

[0057]
In Table 1, the flow rate of the liquid indicates the flow rate as a gas when the liquid is vaporized. Further, at the time of gas discharge, at least hydrogen or an organic substance is supplied as a gas or a liquid. Generally, when reduction is performed, it is preferable that no polymer is formed on the surface of the material to be treated. As can be seen from Table 1, when oxygen is mixed with the discharge gas, the polymerization can be suppressed, but the reducing property also becomes small. It is also found that the addition of water can suppress polymerization without affecting the reducibility.
[0058]
FIG. 7 shows another embodiment of the surface treatment apparatus used in the method according to the present invention. In this surface treatment device 22, a rod-shaped electrode 24 connected to a power source 23 is vertically held in a state of being electrically floated by an insulating fixture 26 at the center of a box-shaped metal cover 25 opened downward. Have been. The metal cover 25 is grounded, completely accommodates the electrode 24 therein, and has a lower end 27 extending to near the tip of the electrode 24 to define an opening 28 below. This lower end 27 serves as a counter electrode of the electrode 24. The inside of the metal cover 25 communicates with a gas supply device 29 that supplies a discharge gas. A metal mesh 30 is disposed in the opening 28, and a workpiece to be surface-treated is disposed below the metal mesh 30.
[0059]
A predetermined discharge gas is supplied from the gas supply device 29, and the inside of the metal cover 25 is replaced with the discharge gas. When a voltage is applied from the power supply 23 to the electrode 24, gas discharge occurs between the tip of the electrode 24 and the lower end 27 of the metal cover. Since the discharge gas is continuously supplied from the gas supply device 29 into the metal cover 25, the gas active species generated in the discharge region 31 becomes a reactive gas flow 32 together with the discharge gas to be opened. It is jetted downward from 28. The substrate is surface-treated by the gas active species contained in the reactive gas stream. At this time, in the reactive gas flow 32, ions generated by the discharge are trapped and neutralized by the metal mesh 30, so that damage to the surface-treated substrate can be further reduced.
[0060]
In another embodiment, for example, a conduit such as a flexible tube is connected to the lower end opening 28 of the metal cover 25, and a reactive gas flow can be ejected from a nozzle provided at the end thereof. The substrate to be subjected to the surface treatment is disposed at a position different from the surface treatment device 22 main body, and is exposed to the reactive gas flow through the conduit. This allows the processing to be performed by changing the flow rate of the gas flow, the shape of the nozzle, and the like in accordance with the processing conditions such as the shape and dimensions of the substrate as the material to be processed. It is possible, and workability can be improved.
[0061]
FIG. 8 shows a surface treatment apparatus for use in another embodiment of the surface treatment method according to the present invention. The surface treatment device 33 has a flat plate-shaped electrode 35 connected to a power supply 34 and arranged horizontally. A container 37 for storing a predetermined liquid 36 is disposed below the electrode 35, and a gas supply device 38 for supplying a discharge gas is provided. And is arranged toward a narrow space defined between them. At the bottom of the container 37, a grounded metal plate 40 serving as a counter electrode of the electrode 35 is disposed in parallel with a position corresponding to the electrode 35. The material 41 to be surface-treated is immersed in the liquid 36 and placed on the bottom of the container 37 at a position corresponding to the metal plate 40.
[0062]
As in the above-described embodiments, a predetermined discharge gas is ejected from the gas ejection port 39 of the gas supply device 38 to replace the space between the electrode 35 and the liquid surface of the liquid 36 with the discharge gas. I do. Next, when a voltage is applied to the electrode 35 from the power supply 34, gas discharge occurs between the electrode 35 and the liquid surface. In the discharge region 42, active species of the discharge gas are generated by the plasma, and the active species are mixed into the liquid 36 to perform a surface treatment on the workpiece 41.
[0063]
When a gas containing oxygen, for example, a mixed gas of helium and oxygen is used as the discharge gas, active species such as oxygen radicals and ozone are generated in the discharge region 42 by the gas discharge. When the liquid 36 is water, preferably pure water, the ozone is mixed into the liquid 36 to turn the liquid 36 into ozone water. Demonstrate. On the other hand, when surface treatment is actually performed by using a hydrogen peroxide solution by a wet method, the treatment cost is high because the hydrogen peroxide solution itself is expensive, and it is harmful to the human body. , And the work is complicated and complicated. ADVANTAGE OF THE INVENTION According to this invention, a sufficiently high oxidation treatment capacity can be obtained at low cost, handling is simple, and workability is improved.
[0064]
In another embodiment, a gas containing a fluorine compound such as CF ₄ , C ₂ F ₆ , or SF ₆ can be used as the discharge gas. In this case, the gas discharge generates active species such as fluorine ions and excited species. When water is used for the liquid 36, the fluorine ions are mixed into the water and the liquid 36 becomes hydrogen fluoride (HF) water, so that the surface of the processing target material 41 can be etched. This can be used, for example, in wet etching of a silicon wafer to remove an oxide film from its surface.
[0065]
Further, a gas containing nitrogen, for example, a simple gas of nitrogen, a mixed gas of nitrogen and helium, or compressed air can be used as the discharge gas. When the liquid 36 is sulfuric acid, the gas discharge generates active species such as nitrogen ions and excited species, and the nitrogen ions are mixed into the sulfuric acid and changed into ammonium persulfate. As a result, the cleaning performance of the liquid 36 is equivalent to that of the ammonia peroxide solution, and organic substances and the like adhering to the surface of the processing target material 41 can be removed. In particular, this method is effective when applied to wet etching after ashing of a resist formed on a substrate or the like.
[0066]
According to the surface treatment method of the present embodiment, various surface treatments such as oxidation, etching, and cleaning can be performed inexpensively and easily by appropriately selecting and combining the discharge gas and the liquid 36 as described above. It can be carried out. By maintaining the cleanliness of the liquid in which the material to be immersed is kept at a constant high level, the material to be treated can be protected from contamination of substances generated by the surface treatment. FIG. 9 shows a modified embodiment of such a surface treatment apparatus.
[0067]
In the embodiment of FIG. 9, an inlet 43 and an outlet 44 for the liquid 36 are provided at both ends of a container 37 for storing the liquid 36, and a pure water regenerating device 46 is provided in the middle of a circulation line 45 connecting these. Is provided. The liquid 36 in the container 37 is sent from a discharge port 44 to a pure water regenerating device 46 via a circulation pipe 45 to remove impurity ions and dust generated by surface treatment of the material 41 to be processed, and then to an injection port 43. From the container 37. Therefore, the liquid 36 in the container 37 can be always maintained at a high degree of cleanliness, not only eliminating the possibility of contamination, but also eliminating the need to replace the liquid 36 during the surface treatment operation, and improving workability and productivity. Is improved. The pure water regenerating apparatus 46 is a known means conventionally used, and is made up of activated carbon, ion exchange resin, various filters, and the like, and is configured by appropriately selecting or combining these. When the liquid 36 is other than pure water, it is configured and used as filtering means corresponding to the type of the liquid.
[0068]
FIG. 10 shows another embodiment of a surface treatment apparatus for similarly treating a material to be treated in a liquid. In the surface treatment apparatus 47 of the present embodiment, an electrode 49 connected to a power supply 48 and a grounded electrode 50 as a counter electrode thereof are arranged in a casing 51 so as to face each other with a certain interval. The casing 51 has one end connected to a gas supply device 52 that supplies a discharge gas, and the other end connected to a nozzle 55 formed of a perforated plate disposed at the bottom in a container 54 that stores a liquid 53. I have. The material to be processed 56, for example, a substrate, is immersed in the liquid 53 of the container 54 and arranged above the nozzle 55. In the present embodiment, as shown in the figure, a large number of workpieces 56 are vertically arranged in the liquid 53 in parallel with the size of the container 54.
[0069]
The discharge gas is supplied from the gas supply device 52 into the casing 51, and the space between the electrodes 49 and 50 is replaced with the discharge gas. When a voltage is applied from the power supply 48 to the electrode 49, gas discharge occurs in the space between the two electrodes. The active species of the discharge gas generated in the discharge region 57 are supplied to the nozzle 55 as a reactive gas flow by continuously supplying the discharge gas from the gas supply device 52, and Spouts out as a foam. By disposing the nozzle 55 at the bottom of the container 54, the bubbles of the reactive gas serve to stir the liquid 53, and as a result, the liquid 53 is more uniformly mixed with the gas active species, and Surface treatment. In order to increase the efficiency of dissolving the reactive gas in the liquid 53, it is more advantageous to make the hole diameter of the porous plate constituting the nozzle 55 smaller.
[0070]
Thus, similarly to the embodiment shown in FIGS. 8 and 9, surface treatment such as oxidation, etching, and cleaning of the processing target material 56 can be performed according to the type of the discharge gas and the liquid 53. Moreover, in the present embodiment, the container 54 and the discharge unit for generating gaseous active species are separately provided at a distance from each other, and are connected via an appropriate conduit. By adjusting the supply amount of the sheath gas or the like, it is possible to perform surface treatment on a large number of materials to be processed or various shapes, dimensions, and sizes at once.
[0071]
11 and 12 show modifications of the embodiment of FIGS. 8 and 9, respectively. In these modified embodiments, the material to be treated 41 is arranged outside the container 37. 8 and 9, the excited active species of the discharge gas supplied from the gas supply device 38 are generated by the gas discharge generated between the electrode 35 and the surface of the liquid 36. The mixed liquid 36 is distributed toward the material 41 to be processed, and flows on the surface of the material to be processed while controlling the flow rate with the stopper 58. According to the present invention, by appropriately combining the types of the liquid 36 and the discharge gas, various surface treatments such as oxidation, etching, and ashing can be similarly performed on the material 41 to be processed.
[0072]
In particular, in the embodiment of FIG. 12, similarly to the embodiment of FIG. 9, the liquid 36 is circulated to the container 37 while being regenerated by the pure water regenerating device 46, and the liquid 36 mixed with the excited active species is supplied to the container 37. To the material 41 to be processed. Further, in these modified examples, while the pure water is continuously supplied or circulated to the container 37, the plug 58 is closed and the discharge supplied from the gas supply device 38 while the surface of the processing target material 41 is being treated. After changing the property of the liquid 36 by changing the type of the use gas, the plug 58 is opened again, so that a different surface treatment can be continuously performed on the workpiece 41.
[0073]
As described above, according to the modified embodiment shown in FIGS. 11 and 12, the material to be processed 41 is arranged outside the container 37 for generating the gas discharge, so that the container 37 is changed according to the size, size and shape. There is no need, and the entire device can be downsized. Further, the processing capacity can be easily controlled according to the required scale of processing, and single-wafer processing and batch processing can be performed as necessary, so that cost can be reduced.
[0074]
FIG. 13 shows another embodiment of the surface treatment method according to the present invention. In the present embodiment, a relatively large workpiece 41 such as glass for a liquid crystal panel or a wafer substrate is placed in a cleaning tank 59, and is cleaned using pure water continuously supplied therein. The used pure water discharged from the cleaning tank 59 is sent to the container 37. The used pure water contains the organic matter removed from the material to be treated 41 and floats on the liquid surface of the container 37. An electrode 35 connected to a power source 34 is disposed above the container 37 with a slight gap between it and the liquid level, and is grounded to the bottom of the container 37, as in the embodiment of FIGS. An electrode 40 is provided.
[0075]
A gas discharge is generated while supplying a discharge gas from a gas supply device 38 between the electrode 35 and the surface of the liquid 36, and the surface of the liquid 36 is treated using the gas active species generated thereby. By using compressed air or a mixed gas of oxygen and helium or nitrogen as the discharge gas, the organic substances floating on the liquid surface of the container 37 are removed by ashing. The purified water thus purified is sent to the cleaning tank 59 and reused for cleaning the workpiece 41.
[0076]
As described above, according to the present invention, regardless of the size, shape, and size of the workpiece 41, the workpiece 41 is fixed at a desired position and is continuously cleaned by circulating pure water while cleaning. Therefore, it is possible to easily cope with the recent increase in size of glass substrates and wafers for liquid crystal panels, and it is possible to perform single-wafer processing and batch processing. Further, according to the present invention, even in the case of performing a process such as cleaning using a liquid other than pure water, the cleanliness can be easily recovered by performing the ashing process on the used liquid in the same manner, and the liquid can be reused. can do.
[0077]
FIG. 14 illustrates a method for forming an alignment film of a liquid crystal display device to which the surface treatment method according to the present invention is applied. A synthetic resin film 61 such as an organic polymer resin is applied to the upper surface of a counter substrate 60 of a liquid crystal panel on which elements such as TFTs, MIMs (Metal Insulator Metals), and ITO, an electrode pattern, or a color filter are formed. . Above the substrate 60, an alignment treatment device 62 to which the surface treatment method using plasma under atmospheric pressure of the present invention is applied is disposed. This alignment processing device has an electrode 64 connected to a power supply 63 and an electrode 65 grounded as a counter electrode. The electrode 64 on the power supply side is entirely covered with an insulator 66 such as glass or ceramic. The electrode 64 and the electrode 65 covered by the insulator 66 are arranged so as to oppose each other at a fixed interval, and to be inclined at a certain angle a with respect to the surfaces of the substrate 60 and the synthetic resin film 61 as shown in the figure. ing. The angle a is appropriately set within the range of 0 degrees <a <90 degrees. The space defined between the electrodes 64 and 65 is connected to a gas supply device 67 for supplying a discharge gas.
[0078]
When a voltage is applied from the power supply 63 to the electrode 64 while a discharge gas is supplied from the gas supply device 67 to the space between the electrodes 64 and 65, a gas discharge is generated in the space at or below atmospheric pressure. . The gas discharge may be any discharge such as a glow discharge, a corona discharge, and an arc discharge as long as the discharge gas generates active species. Since the electrode 64 is covered with the insulator 66, the discharge state between the two electrodes can be made uniform. At this time, not the power supply electrode 64 but the ground electrode 65 may be covered with an insulator, or both electrodes may be covered with an insulator.
[0079]
The active species of the discharge gas generated in the discharge region 68 by the gas discharge are inclined at an angle a on the surface of the synthetic resin film 61 as a reactive gas flow by the discharge gas continuously supplied from the gas supply device 67. Sprayed from above. Thereby, the surface of the synthetic resin film 61 is oriented rightward in FIG. Further, by moving the substrate 60 relatively in the front-rear and left-right directions with respect to the alignment processing device 62, the entire surface of the synthetic resin film 61 can be uniformly aligned.
[0080]
FIG. 15 shows an embodiment of a line type alignment processing apparatus according to the present invention. The orientation processing device 69 includes a gas supply device 67, a discharge generating section 70 having a power supply electrode and a ground electrode as in the embodiment of FIG. 14, and a blowing nozzle 71. The blowing nozzle 71 is formed of an insulating material such as glass, ceramic, or the like, and has a linear, narrow-width blowing outlet 72 like a so-called air knife near and toward the surface of the substrate 60 on which the synthetic resin film 61 is formed. They are arranged at an angle a (0 degrees <a <90 degrees).
[0081]
By supplying a predetermined discharge gas from the gas supply device 67 to the discharge generating unit 70 and applying a voltage to the power supply electrode, a gas discharge is generated in the discharge gas at or near atmospheric pressure. . By this gas discharge, the active species of the discharge gas generated in the discharge generating section 70 become a reactive gas flow by continuously sending the discharge gas from the gas supply device 67, and FIG. 15A and FIG. As shown in the drawing, the air is sprayed from the tip outlet 72 of the outlet nozzle 71 onto the surface of the synthetic resin film 61 of the substrate 60 at an angle a from an obliquely upper side over the entire width thereof.
[0082]
Thereby, the synthetic resin film 61 is oriented in the same manner as in the embodiment of FIG. At this time, it is preferable to inject the gas stream more strongly at a pressure of, for example, about 7 kg / cm ^2, because the orientation treatment can be performed more effectively and quickly. In addition, the entire surface of the coating film 61 can be easily processed by moving the substrate 60 relative to the alignment processing device 69 in the left-right direction. Further, the discharge generating section 70 and the blowing nozzle 71 can be connected by an appropriate conduit such as a flexible tube.
[0083]
As a gas type of the discharge gas, a gas containing at least oxygen such as compressed air, a mixed gas of nitrogen and oxygen, or a mixed gas of oxygen and helium is used. In this case, excited gaseous species such as ozone and oxygen radicals are generated by the gas discharge. When compressed air or a mixed gas of nitrogen and oxygen is used as the discharge gas, a high voltage is applied between the two electrodes of the discharge generating section 70. The discharge at this time is a corona discharge. When a mixed gas of helium and oxygen is used as a discharge gas, a glow discharge is generated using a high-frequency power supply of 13.56 MHz, for example.
[0084]
FIG. 16 shows another embodiment of the method for forming an alignment film of a liquid crystal panel according to the present invention. In this embodiment, a substrate 73 to be oriented is placed on a grounded metal plate 74, and a metal electrode 75 is disposed immediately above the substrate. The electrode 75 has the same air knife structure as the blowing nozzle 71 of the embodiment of FIG. 15, and has a passage 76 connected to a gas supply device 67 and an elongated slit-shaped outlet 77.
[0085]
The electrode 75 is arranged close to the substrate 73 as shown in FIG. 16 and such that the discharge gas is blown obliquely from above from the outlet 77 to the surface thereof. A high-frequency voltage is applied to the electrode 75 from the power supply while supplying a predetermined discharge gas from the gas supply device 67 into the passage 76 and injecting the gas from the outlet 77 onto the substrate surface. The metal plate 74 serves as a counter electrode of the electrode 75, and discharge occurs between the tip of the electrode 75 and the substrate 73. In the discharge region 78, excited active species of the discharge gas are generated, and are sprayed on the surface of the substrate 73 by the discharge gas continuously ejected from the outlet 77. Thereby, a desired alignment treatment is performed on the substrate surface.
[0086]
When a synthetic resin film is formed in advance on the surface of the substrate 73 as in the embodiments of FIGS. 14 and 15, a mixed gas of helium and oxygen is used. In this case, excited active species such as ozone and oxygen radicals are generated as in the above-described embodiment, and the synthetic resin film is subjected to the orientation treatment by the same surface treatment as ashing.
As described above, according to the present invention, since the alignment treatment can be performed in a non-contact manner, there is no possibility of damaging or peeling the surface of the synthetic resin film, and uniform alignment can be provided. Control of the angle of the alignment film mainly depends on the angle at which the reactive gas is blown, and furthermore, partly depends on the voltage applied to the electrode and the gas type of the discharge gas. can do.
[0087]
In another embodiment, the alignment film can be formed directly on the substrate surface by selecting the discharge gas to include an appropriate organic substance that is liquid at room temperature. For example, when decane (C ₁₀ H ₂₂ ) is added to helium or silicone is added to helium, a resin film is formed on the surface of the substrate 73 by polymerizing in a desired orientation direction. When oxygen and silicone are added to helium, a silicon oxide (SiO ₂ ) film is formed.
[0088]
FIG. 17 shows a modification of FIG. 16 for forming an alignment film directly on a substrate. In this modification, the electrodes 75 are arranged vertically so that the discharge gas is blown from the outlet 77 substantially at right angles to the substrate 73. The substrate 73 is moved relative to the electrode 75 in one of the left and right directions simultaneously with the discharge. Thus, by appropriately setting the moving speed of the substrate in accordance with the film forming speed, the resin film can grow obliquely, and a desired alignment film can be obtained.
[0089]
Next, a method for forming an alignment film of a liquid crystal panel according to the present invention will be specifically described with reference to examples.
(Example 1)
The polyimide film on the surface of the MIM substrate 80 on which the wiring pattern was formed was subjected to an orientation treatment under the following conditions using a spot type surface treatment apparatus 81 shown in FIG. The surface treatment device 81 has an electrode 83 arranged at the center of a quartz tube 82 having a double structure, connected to a power supply 85 via a control circuit 84, and connected to a ground electrode 86 arranged outside the quartz tube 82. Discharged. A discharge gas was continuously supplied from outside to the inside of the quartz tube 82, and a gas flow containing the active species of the gas generated in the discharge region 87 was jetted from the gas jet 88 to the surface of the substrate 80. . The substrate 80 was disposed obliquely to the gas flow at an angle of θ = 10 to 30 degrees.
Gas used: Compressed air gas pressure: 3-7 kg / cm ²
Power consumption: 100-200W
Processing time: 20 minutes
The liquid crystal was sandwiched between the substrate 80 thus subjected to the alignment treatment and the substrate on which the alignment film was formed by the conventional rubbing treatment, and polarizing plates were disposed on both sides of the liquid crystal. . As a result, the portion of the polyimide film to which the gas flow was applied was oriented in the direction of the gas flow.
[0091]
(Example 2)
Similarly, the polyimide film on the surface of the MIM substrate 80 provided with the wiring pattern was subjected to an orientation treatment using the line type surface treatment device 89 shown in FIGS. 19A and 19B under the following conditions. The surface treatment device 89 has an elongated gas outlet 91 formed in the bottom surface of a power supply 90 connected to a power supply 85 along the longitudinal direction thereof, and discharges a discharge gas to a surface of a substrate 80 which is horizontally transported immediately below the gas outlet 91. The polyimide coating was directly exposed to electric discharge.

[0092]
When the orientation state of the polyimide film was observed in the same manner as in Example 1, it was found that the polyimide film was well oriented over the entire surface of the substrate.
[0093]
(Example 3)
Similarly, the polyimide film on the surface of the MIM substrate 80 provided with the wiring pattern was subjected to an orientation treatment under the following conditions by using a spot type surface treatment device 92 shown in FIGS. 20A and 20B. The surface treatment device 92 sandwiches an elongated glass tube 95 between the power supply electrode 93 and the ground electrode 94, and generates a discharge between the two electrodes while flowing a discharge gas from one end to the other end. Was. The substrate 80 was disposed in the vicinity of the other end of the glass tube 95 at an angle of θ = 10 to 30 degrees with respect to the gas flow ejected from the other end opening.

[0094]
When the orientation state of the polyimide film was observed in the same manner as in Example 1, it was confirmed that the polyimide film was oriented in processing times of 1 minute and 3 minutes. In the case of this embodiment, since the substrate 80 is not directly exposed to the discharge, there is no possibility that the substrate is charged up, and the processing speed is relatively slow, so that the alignment process can be more easily controlled.
In any of the above Examples 1 to 3, it is considered that the orientation treatment was performed on the polyimide film of the substrate 80 by the same surface treatment as ashing, based on the type of the discharge gas used.
[0095]
(Example 4)
An alignment film was directly formed on the surface of the Pyrex glass substrate 96 where no wiring pattern was formed, using the surface treatment apparatus shown in FIG. 21 under the following conditions. This surface treatment apparatus has the same configuration as that of the embodiment of FIG. 16, and discharges directly between the power supply electrode 75 and the glass substrate 96 on the ground electrode 74. The discharge gas is mixed with an organic substance 99 which is liquid at normal temperature in a container 98 by appropriately adjusting the control valves 100 and 101 into a gas sent from a gas supply device 97 and mixing the gas through a passage 76 inside the electrode 75. The polymer film 102 of the organic substance 99 was formed on the surface of the glass substrate by obliquely jetting it from the outlet 77 onto the surface of the substrate 96. The gap between the electrode 75 and the surface of the substrate 96 was 1 mm, and the inclination angle of the electrode 75 with respect to the substrate 96 was θ = 60 degrees.
Gas used: Helium gas flow rate: 20 L / min Liquid organic matter: OH-modified silicone, silicone oil, n-decane Power consumption: 150 W
[0096]
When the alignment state was similarly observed with the liquid crystal interposed between the two substrates 96 on which the polymer film 102 was formed, the portion 103 of the polymer film 102 near the gas outlet 77 was not aligned. The portion 102 far from 77 was oriented.
[0097]
(Example 5)
An alignment film was directly formed on the surface of the same glass substrate 96 as in Example 4 under the following conditions. As shown in FIG. 22, a discharge was performed directly between the surface of the glass substrate 96 disposed on the ground electrode 74 and the power supply electrode 105, and a discharge gas was jetted from the gas outlet 106 to the discharge region from the lateral direction. . The same discharge gas as in Example 4 was used, and a polymer film 102 was formed on the substrate surface.
Gas used: Helium gas flow rate: 20 L / min Liquid organic matter: OH-modified silicone, silicone oil, n-decane Power consumption: 150 W
[0098]
In the polymer film 102, as in Example 4, the portion 103 near the gas outlet 106 was not oriented, but the portion 104 far away was oriented.
[0099]
(Example 6)
An alignment film was directly formed on the same surface of the glass substrate 96 as in Example 4 using the surface treatment apparatus shown in FIG. 23 under the following conditions. This surface treatment apparatus supplies a discharge gas mixed with a liquid organic substance 99 at room temperature to the inside of the dielectric 107 in the same manner as in the fourth embodiment, and connects the power supply electrode 108 inside the dielectric with the external ground electrode 109. A gas flow containing the active species of the gas due to the discharge is injected from the gas outlet 110 to the surface of the glass substrate 96 obliquely at an angle of 60 degrees, and the polymer film 111 is formed over the entire surface. Formed. This polymer film had a pretilt angle of liquid crystal of 90 degrees and was not oriented.
Gas used: Helium gas flow rate: 20 L / min Liquid organic matter: OH-modified silicone Power used: 150 W
[0100]
Next, as shown in FIG. 24, the glass substrate 96 mounted on the ground electrode 112 was directly discharged between the power supply electrode 113 while being horizontally transported. Helium, nitrogen, compressed air, and the like, which are often used for surface treatment for improving wettability, were supplied from the gas supply device 114 as a discharge gas. As a result, the polymer film 111 was well oriented on the entire surface of the substrate 96.
[0101]
(Example 7)
The same experiment as in Example 6 was performed using an MIM substrate provided with a wiring pattern. A well-oriented polymer film was formed on the substrate surface as in the example.
[0102]
As described above, the preferred embodiments of the present invention have been described in detail. However, the present invention can be implemented by adding various modifications and changes to the above embodiments within the technical scope thereof. For example, in the surface treatment apparatus shown in FIGS. 1 and 7, the electrodes are coated with an insulator or a dielectric material to generate a more uniform electric discharge as in the embodiment shown in FIG. Can prevent the material to be processed from being contaminated by the substances generated by the method. Further, by forming the electrodes of the surface treatment device in a plate shape and arranging the electrodes vertically, the electrode can be used as a so-called line type surface treatment device that generates a discharge in a straight line in the longitudinal direction. As the electrode structure of the surface treatment apparatus, in addition to the electrode structure of the above embodiment, for example, as described in Japanese Patent Application No. 5-113204 by the applicant of the present invention, a gas flow path formed of a dielectric material is used. A gas for discharge is introduced, a high-frequency voltage is applied to an electrode disposed outside thereof, and a gas discharge is generated in the gas flow path under a pressure near the atmospheric pressure. Those having a structure to be subjected to surface treatment by utilizing can also be used.
[0103]
【The invention's effect】
According to the substrate surface treatment method of the present invention, the metal layer on the substrate surface is easily and quickly oxidized without damaging other parts of the substrate, for example, electronic components and the like, and the surface is oxidized with metal. Since a film of an object can be formed, corrosion of wirings, electrodes, and the like formed on the substrate can be effectively prevented, reliability of the electronic circuit can be improved, and the life can be prolonged.
[0104]
By utilizing this surface treatment method, according to the method for forming a multilayer wiring board of the present invention, since the surface of the first metal wiring is covered with the metal oxide and has corrosion resistance, the second metal wiring is etched. In this case, there is no possibility that the lower first metal wiring is etched, and the interlayer insulating film formed therebetween does not need to be formed unnecessarily thicker than its original insulating function, and is thinned. Accordingly, the time required for the film formation can be shortened, the cost can be reduced, the productivity can be improved, and the thickness of the substrate can be reduced.
[0105]
Further, according to the substrate surface treatment method of the present invention, the metal oxide layer on the substrate surface can be reduced easily and at high speed by reducing the metal oxide layer without damaging other parts of the substrate, such as electronic components. When the metal oxide layer is a transparent electrode made of ITO or the like, the thickness of the metal oxide layer is reduced to maintain a desired transparency while lowering the resistance to achieve a desired electrical performance. Can be secured.
[0106]
Further, according to the surface treatment method of the present invention, by appropriately selecting a liquid and a discharge gas to be used, for example, hydrogen peroxide solution, oxidizing, etching, The surface treatment ability such as cleaning can be imparted at a low cost, or the liquid itself used for the surface treatment such as cleaning can be easily cleaned and reused at a low cost. Because it is relatively easy and safe, workability is greatly improved. In particular, by separately performing discharge to the liquid and surface treatment of the material to be treated using the liquid, the surface treatment is performed irrespective of the size, shape, and location of the material to be treated. Batch processing becomes possible, and different surface treatments can be continuously performed on the material to be processed, so that the apparatus can be downsized and the processing capacity can be improved. In addition, such a surface treatment method can be realized at a low cost with a relatively simple structure by configuring the surface treatment apparatus as in the tenth aspect.
[0107]
Further, according to the surface treatment method of the present invention, a portion for generating a gas discharge and a portion for surface-treating the material to be treated are provided at separate positions, and these are connected to supply a gas containing gas active species to the liquid. And, since it can be used for the material to be treated and subjected to surface treatment, the treatment conditions, such as the treatment purpose, the shape and dimensions of the material to be treated, the number to be treated at a time, etc., or the gas used for gas discharge Surface treatment can be performed according to the type, the environment in which discharge is performed, and the like, and the treatment capacity can be appropriately adjusted. In addition, single-wafer processing and batch processing can be selectively used depending on the purpose and application, so that processing operations such as handling of discharge gas are relatively easy and safe, and productivity can be improved. Such a surface treatment method can be realized at a low cost with a relatively simple configuration.
[0108]
According to the method for forming an alignment film of a liquid crystal panel of the present invention, by injecting a gas flow containing gaseous active species obliquely onto the substrate surface, the alignment treatment can be performed in a non-contact manner on the synthetic resin film on the substrate surface, or Since the alignment film can be formed directly on the surface, there is no danger of damaging or peeling the alignment film as in the past, and the yield is improved, and the processing time is short and single-wafer processing is possible. And cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a view schematically showing a configuration of a surface treatment apparatus used in a substrate surface treatment method according to the present invention.
FIGS. 2A and 2B are diagrams showing steps of forming a multilayer wiring by using the substrate surface treatment method according to the present invention.
FIG. 3 is a plan view showing a glass substrate on which a reduction process is performed according to the present invention.
FIG. 4 is a block diagram showing a configuration for causing a discharge gas to contain water vapor or an organic vaporized gas in the reduction treatment according to the present invention.
FIG. 5 is a block diagram showing another configuration different from FIG. 4;
FIG. 6 is a block diagram showing another embodiment further different from FIG. 4;
FIG. 7 is a view showing another embodiment of the surface treatment apparatus used in the surface treatment method of the present invention.
FIG. 8 is a diagram showing a surface treatment apparatus used in an embodiment of a surface treatment method different from that of FIG. 7;
FIG. 9 is a diagram showing a modification of FIG. 8;
FIG. 10 is a diagram showing a surface treatment apparatus used in still another embodiment different from FIG. 7;
FIG. 11 is a diagram showing another modified example of FIG. 8;
FIG. 12 is a diagram showing a modification of FIG. 9;
FIG. 13 is a view showing another embodiment of the surface treatment method according to the present invention.
FIG. 14 is a diagram illustrating a method for forming an alignment film of a liquid crystal panel using the surface treatment method according to the present invention.
FIG. 15 is a side view schematically showing an embodiment of a line type alignment treatment apparatus, and FIG. 15 is a top view thereof.
FIG. 16 is a diagram showing an embodiment of an orientation processing apparatus different from that in FIG. 15;
FIG. 17 is a diagram showing a modification of the embodiment in FIG. 16;
FIG. 18 is a diagram illustrating a method of performing an alignment treatment on a liquid crystal panel using a spot type surface treatment apparatus.
FIG. 19 is a side view showing a line type surface treatment apparatus used for a liquid crystal panel alignment treatment method, and FIG.
FIG. 20 is a side view showing a spot-type surface treatment apparatus used in a liquid crystal panel alignment treatment method, and FIG. 20 is an end view thereof.
FIG. 21 is a view schematically showing a method for forming an alignment film of a liquid crystal panel according to the present invention.
FIG. 22 is a diagram showing a modification of FIG. 21;
FIG. 23 is a diagram showing the first half of a process in another embodiment of the method for forming an alignment film of a liquid crystal panel according to the present invention.
FIG. 24 is a view showing a latter half step in the embodiment in FIG. 23;
[Explanation of symbols]
Reference Signs List 1 surface treatment device, 2 power supply, 3 electrodes, 4 space, 5 gas supply device, 6 substrate, 7 metal wiring, 8 discharge region, 9 metal oxide film, 10 SiO ₂ layer, 11 metal film, 12 glass substrate, 13 transparent Electrode, 14 display area, 15 conduit, 16 valve, 17 tank, 18 water or liquid organic matter, 19 heater, 20 spraying device, 21 conduit, 22 surface treatment device, 23 power supply, 24 electrode, 25 metal cover, 26 insulation Mounting fixture, 27 lower end, 28 opening, 29 gas supply device, 30 metal mesh, 31 discharge area, 32 reactive gas flow, 33 surface treatment device, 34 power supply, 35 electrode, 36 liquid, 37 container, 38 gas supply device , 39 gas ejection port, 40 metal plate, 41 material to be treated, 42 discharge area, 43 injection port, 44 discharge port, 45 circulation line, 46 pure water regeneration device, 47 surface treatment device, Reference Signs List 8 power supply, 49, 50 electrodes, 51 casing, 52 gas supply device, 53 liquid, 54 container, 55 nozzle, 56 material to be treated, 57 discharge area, 58 stopper, 59 cleaning tank, 60 substrate, 61 synthetic resin film, 62 Orientation treatment device, 63 power supply, 64, 65 electrodes, 66 insulator, 67 gas supply device, 68 discharge area, 69 orientation treatment device, 70 discharge generation part, 71 blow nozzle, 72 tip outlet, 73 substrate, 74 metal plate , 75 electrode, 76 passage, 77 outlet, 78 discharge area, 80 MIM substrate, 81 surface treatment device, 82 quartz tube, 83 electrode, 84 control circuit, 85 power supply, 86 ground electrode, 87 discharge area, 88 gas outlet , 89 surface treatment device, 90 power supply, 91 gas outlet, 92 surface treatment device, 93 power supply electrode, 94 ground electrode, 95 glass tube, 96 glass substrate, 97 Gas supply device, 98 container, 99 organic matter, 100, 101 control valve, 102 polymer film, 103, 104 part, 105 power electrode, 106 gas outlet, 107 dielectric, 108 power electrode, 109 ground electrode, 110 gas outlet , 111 Polymer film, 112 Ground electrode, 113 Power electrode, 114 Gas supply device

Claims (4)

A method for forming an alignment film on a substrate surface of a liquid crystal panel,
A gas discharge is generated in a predetermined gas under atmospheric pressure or a pressure in the vicinity thereof, and a gas flow containing the active species of the gas generated by the discharge is directed toward the substrate surface, in an orientation direction to be applied. A method for forming an alignment film for a liquid crystal panel, comprising: exposing the active species to the substrate surface by obliquely jetting the active species. 2. The method according to claim 1, wherein a synthetic resin film is formed on the surface of the substrate in advance, and the active species is exposed to the synthetic resin film. The predetermined gas contains an organic substance that is liquid at normal temperature, and after forming a film on the substrate surface with the active species, a second gas discharge is generated under atmospheric pressure or a pressure in the vicinity thereof, whereby 2. The method for forming an alignment film of a liquid crystal panel according to claim 1, wherein the generated second gas active species is exposed to a film forming surface of the substrate. A method for forming an alignment film on a substrate surface of a liquid crystal panel,
A gas discharge is generated under atmospheric pressure or a pressure near the atmospheric pressure, and a predetermined gas containing a liquid organic substance at room temperature is jetted in an orientation direction to be applied toward the substrate surface exposed to the discharge, A method for forming an alignment film for a liquid crystal panel, comprising: forming a film on the surface of the substrate using active species of the gas generated by electric discharge.

Images