JP2004296552A

JP2004296552A - Substrate drying equipment

Info

Publication number: JP2004296552A
Application number: JP2003083816A
Authority: JP
Inventors: Hiroki Tsuji; 寛樹辻; Kiyoshi Shimada; 清嶋田; Hiroyoshi Nobata; 博敬野畑
Original assignee: SPC Electronics Corp
Current assignee: SPC Electronics Corp
Priority date: 2003-03-25
Filing date: 2003-03-25
Publication date: 2004-10-21

Abstract

<P>PROBLEM TO BE SOLVED: To enable adjusting capacity of mist by water-soluble organic solvent, and miniaturize the whole equipment without arranging a mist spraying apparatus in a drying room. <P>SOLUTION: The substrate drying equipment is provided with a processing tank 81 which stores deionized water and immerses a substrate 1, an outside tank 32 which has a canopy 31 which carries out covering installation of the processing tank 81, and carries in the substrate 1 to top view, and a spraying means 41 which is installed in the outside tank 32 and sprays high temperature inert gas on a stored liquid surface from the internal processing tank 81. Further, a spraying means 51 is installed which is placed in the vicinity of the spraying means 41 of the outside tank 32, mixes water soluble organic solvent and inert gas, makes mist outside the processing tank 81, and supplies the mist, thereby spraying the mist on a stored liquid surface from above the processing tank 81. By discharging deionized water in the processing tank 81, the substrate is exposed on the liquid surface, and Maragoni effect due to mist spraying and sticking deionized water are replaced. The substrate is dried completely by flashing by spraying inert gas at a high temperature. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は基板乾燥装置に係り、より詳細には、水の表面張力によるメニスカスと水に溶け易い水溶性有機溶剤を含んだミストによるマランゴニ効果とを利用して、ＬＣＤ基板や半導体ウェーハなどの平板状の基板をその表面に水滴痕を生じさせることなく完全に乾燥させる基板乾燥装置に関する。
【０００２】
【従来の技術】
【特許文献１】
特開２０００−２２３４６６号公報
【０００３】
従来、基板乾燥装置は、洗浄後のＬＣＤ基板や半導体ウェーハなどの平板状の基板をマランゴニ効果を利用してその表面に水滴痕を生じさせることなく完全に乾燥できる装置がよく知られている。このようなマランゴニ効果を利用した従来の基板乾燥装置は、例えば、処理槽に純水を貯留して浸漬させた基板を引き上げる際に生じる表面張力によるメニスカスに、窒素ガスと水溶性有機溶剤であるＩＰＡガスとを混合した蒸気を吹き付けることで、メニスカスの上端から表面張力が低下して水面側に引き戻す力（マランゴニ効果）が発生して基板表面の水滴を排除して完全に乾燥させていた。
【０００４】
しかし、蒸気を用いた基板乾燥装置では、水溶性有機溶剤であるＩＰＡを蒸気化させて供給するためにＩＰＡの消費量が増加するとともに、このＩＰＡを蒸気化する加熱源も必要になってしまう。そこで、従来の基板乾燥装置では、ＩＰＡ液を蒸気化することなく窒素ガスを噴出させてミスト化することで、基板のメニスカスに噴霧させる装置（例えば、特許文献１）がある。図１６は、このようなミストを用いる従来の基板乾燥装置の一実施形態を示す構成図である。また、図１７は、図１６に示した噴霧手段１５１の内部構造を示す図である。
【０００５】
図１６に示すように、ミストを用いる従来の基板乾燥装置の一実施形態は、図示されていないキャリアに支持した洗浄後のウェハ１を浸漬させる純水を貯留した処理槽１８１と、この処理槽１８１内の液面上の空間Ｄ内に窒素ガスを噴射させるとともに、この窒素ガスにより液相のイソプロピルアルコール（以下、単にＩＰＡと記す。）をウェハ１の温度（例えば常温）より高い温度で噴射させてミスト状のＩＰＡを空間Ｄ内に噴霧する噴霧手段１５１とを備えている。
【０００６】
ここで、噴霧手段１５１は、図１７に示すように、フッ素樹脂からなり長く延在した本体に沿ってそれぞれ貫通する窒素ガス用通路１５１ａと液相のＩＰＡ用通路１５１ｄとを備え、窒素ガス用通路１５１ａから延びて複数のウェハ１間に向けて開口した噴射孔１５１ｃを有する細い窒素ガス用噴出通路１５１ｂを多数備えるとともに、ＩＰＡ用通路１５１ｄから延びて窒素ガス用噴出通路１５１ｂの開口端の噴射孔１５１ｃに向けて開口した噴射孔１５１ｆを有する細いＩＰＡ用噴出通路１５１ｅを多数備えている。よって、噴霧手段１５１は、窒素ガス用噴出通路１５１ａの噴射孔１５１ｃから窒素ガスを噴射させると同時にＩＰＡ用噴出通路１５１ｄの噴射孔１５１ｆから液相のＩＰＡを噴射させることでミスト状のＩＰＡを空間Ｄ内のウェハ１間に噴霧することができる。
【０００７】
再び図１６を参照して、窒素（Ｎ_２）ガスは、常温若しくはウェハ１の温度で供給され、減圧弁１５３−１、第１供給弁１５３−２、流量計１５３−３、手動弁１５３−４、１５３−５を介して、処理槽１８１内の左右に配置した噴霧手段１５１にそれぞれ供給される。また、ＩＰＡは、減圧弁１６５−１、第２供給弁１６５−２を介して加圧タンク１６１内に上記とは別の窒素ガスを圧送し、この窒素ガスの圧力により加圧タンク１６１内のＩＰＡの液体が、第３供給弁１５５−１、流量計１５５−２、手動弁１５５−３、１５５−４を介して、処理槽１８１内の左右に配置した噴霧手段１８１にそれぞれ供給される。なお、１６３−１は加圧タンク用の圧抜弁である。
【０００８】
そして、処理槽１８１には、手動弁１８２−３及び第４供給弁１８２−２を介して圧力を一定に保つ排気管１８２−１と、ドレイン弁１８６−２を介して純水を排出するドレイン管１８６−２とを備えている。ここで、第１供給弁１５３−２、第２供給弁１６５−２、第３供給弁１５５−１、第４供給弁１８２−２、及びドレイン弁１８６−２は、制御装置１４０に接続されて、所定のプログラムなどに基づいて、自動的に処理槽１８１内に供給する窒素ガス及び液相のＩＰＡそれぞれの流量、即ち、ＩＰＡのミストの噴霧状態、及び処理槽１８１内の空間Ｄ内からの排気量、並びに純水の排出量などを動作制御できるようにしている。
【０００９】
このような構成からなる従来の基板乾燥装置の一実施形態は、処理槽１８１内に純水を貯留してウェハ１を浸漬させた後、処理槽１８１の純水を排出するか又はウェハ１を処理槽１８１内で上昇させることで、純水の液面からウェハ１を徐々に露出させる。この時、処理槽１８１内では、噴霧手段１５１からウェハ１の表裏両面にＩＰＡをミスト状態、すなわち、窒素をキャリアとするのではなくＩＰＡ自体が単体で窒素ガス中を浮遊している状態で噴霧し続けることで、純水の液面にＩＰＡミストが均一に供給されて生じるマランゴニ効果、及びウェハ１の表裏両面に付着した純水がミスト状のＩＰＡにより置換（蒸発）する効果によって完全に表裏両面を乾燥させる。
【００１０】
このように従来の基板乾燥装置の一実施形態では、水溶性有機溶剤であるＩＰＡを蒸気化ではなくミスト化することで、このＩＰＡの使用量を抑えて、常温により噴霧でき加熱源を不要とするとともに、マランゴニ効果とＩＰＡミストの置換（蒸発）とにより乾燥効果を一層向上させていた。
【００１１】
【発明が解決しようとする課題】
しかしながら、従来の基板乾燥装置では、図１７に示した噴霧手段１５１が噴出孔１５１ｆに供給した液相の水溶性有機溶剤（ＩＰＡ等）を窒素ガスの噴射によりミスト化する構造のため、このミストの大きさを自由に調整することが困難であるという不具合があった。また、噴霧手段１５１は、図１６に示した処理槽１８１内の両側面に各々配置しているため、ウェハ１の出し入れの邪魔になるとともに、処理槽１８１自体の大きさが大型化するという不具合があった。
本発明はこのような課題を解決し、水溶性有機溶剤によるミストの大きさを調整でき、ミスト噴霧装置を乾燥室内に配置せず装置全体を小型化する基板乾燥装置を提供することを目的とする。
【００１２】
【課題を解決するための手段】
本発明による基板乾燥装置は、上述の課題を解決するために、純水を貯留して基板を浸漬する処理槽と、この処理槽の外周及び上部を覆うように覆設して上面に基板を搬入する開閉可能な天蓋を有する外槽と、この外槽に設置して内部の処理槽上方から貯留した液面上に高温不活性ガスを噴射する噴射手段と、外槽の噴射手段近傍に設置して処理槽外で水溶性有機溶剤及び不活性ガスを混合させてミスト化して供給することで処理槽上方から貯留した液面上にミストを噴霧する噴霧手段とを備え、処理槽内の純水を排液するか又は基板を上昇させることで基板を液面上に露出させてミストの噴霧によるマランゴニ効果及び付着した純水の置換とともに、高温不活性ガスの噴射による蒸発によって基板を完全に乾燥するように設ける。
【００１３】
ここで、処理槽には、純水を排液して基板を露出させる場合、基板の形状によらず、純水を常に一定の流量で排液する真空ポンプを備えることが好ましい。また、純水は、基板を露出させる直前の温度が２０℃〜７０℃の温純水であることが好ましい。また、噴射手段は、高温不活性ガスの温度を水溶性有機溶剤の沸点以上にして使用することが好ましい。また、外槽は、処理槽の外周と上部とに覆設して底面を開放することによって、常に新鮮な前記水溶性有機溶剤ミスト及び高温不活性ガスを処理槽の上方から供給するとともに、底面から余剰な水溶性有機溶剤ミスト及び高温不活性ガスを排出することが好ましい。また、基板は、カセットに複数収納して処理槽内にバッチ式に投入して乾燥処理することが好ましい。また、カセットは、処理槽に設けたカセットエレベータを液面上に上昇させて所定の搬送手段により設置または取り出しを行うとともに、カセットエレベータに設置すると降下して処理槽内に投入されることが好ましい。また、カセットの他の実施例としては、処理槽内に所定の搬送手段により直接投入することが好ましい。また、処理槽には、基板をカセットにより投入した際、基板が液面上に露出せず、且つカセットに接触しない位置に保持するための保持手段を設けることが好ましい。また、保持手段は、基板が自立して複数配列する方向に下部でリブ状に延在する複数の保持板を一体に設け、この保持板に基板の下端が接触して保持できる溝部を有し、この溝部の形状がＶ型またはＹ型であるとともに、この溝部に残留する液を吸引できる残液吸引孔と吸引ポンプとを備えることが好ましい。また、保持手段の他の実施例は、基板を自立させるために、垂直に凸部と凹部とを複数交互に配置してリブ状に延在する複数の保持板を一体に設け、この一部の保持板が凹凸の配列をずらして配置され、このずらした保持板の凸部が基板の片側面を保持し、一方のずらしていない保持板の凸部が基板の他の片側面を保持して挟持するように設けることが好ましい。また、保持手段は、保持板の複数の各々厚みを均一に０．５ｍｍ〜１０ｍｍに設けることが好ましい。また、保持板は、基板が接触する凹部及び凸部の材質としてＰＦＡ、ＰＶＤＦ、ＰＴＦＥ、ＰＥＥＫを用いていることが好ましい。また、処理槽には、純水を供給する時、純水を供給する純水供給管に薬液混合弁を設け、少なくとも１種類以上の薬液と純水とを流量計で薬液濃度の調節をして純水供給管内で混合及び攪拌した処理液を供給可能にすることが好ましい。また、純水供給管には、濃度計を更に設け、薬液と純水とを混合及び攪拌した処理液が設定濃度になるまで管理し、設定濃度に達したら処理槽内に供給を開始することが好ましい。また、処理液は、フッ酸水及び純水を混合させた希フッ酸水、過酸化水素水、アンモニア水、アンモニア水及び過酸化水素水並びに純水を混合させたＡＰＭ、塩酸水、塩酸水及び過酸化水素水並びに純水を混合させたＨＰＭであり、それぞれ単独又は混合して使用することが好ましい。また、処理槽では、処理液または純水のみを貯留して洗浄などの基板処理を行った後、基板を液面上に露出させて乾燥処理を行うことが好ましい。また、噴霧手段は、処理槽外で水溶性有機溶剤及び不活性ガスを各々供給して噴射する噴射孔を備えた気液混合チップと、この気液混合チップの噴射孔をドーム状に覆って内部の空間で混合してミスト化するとともにドーム状の外壁に貫通する複数の穴を開口してミストを噴霧するノズルカバーとを備えることが好ましい。また、水溶性有機溶剤は、イソプロパノール、２−プロパノール、イソプロピルアルコール、エタノール、メタノール、ブチルアルコールであり、それぞれ単独又は混合して使用することが好ましい。また、不活性ガスは、窒素、アルゴン、ヘリウムであり、それぞれ単独又は混合して使用することが好ましい。
【００１４】
【発明の実施の形態】
次に、添付図面を参照して本発明による基板乾燥装置の実施の形態を詳細に説明する。図１は、本発明による基板乾燥装置の第１実施形態の概略構成を示す図である。また、図２は、図１に示した基板乾燥装置の詳細な構成を示す構成図である。また、図３は、図１に示した噴霧手段５１の内部構造を示す図である。また、図４は、図１に示した気液混合チップ１０４を示す図である。また、図５は、図１に示した保持手段８３を示す図である。また、図６は、図５に示した保持板８３−２〜４を側面から見た形状を示す図である。
【００１５】
図１に示すように、本発明による基板乾燥装置の第１実施形態は、図１６に示した従来技術とは異なり、純水を貯留して基板を浸漬する処理槽８１と、この処理槽８１の外周及び上部を覆うように覆設して上面に基板を搬入する開閉可能な天蓋３１を有する外槽３２と、この外槽３２に設置して内部の処理槽８１の上方から貯留した液面上に高温不活性ガスを噴射する噴射手段４１と、外槽３２の噴射手段４１の近傍に設置して処理槽８１外で水溶性有機溶剤（ＩＰＡ）及び不活性ガス（Ｎ_２）を混合させてミスト化して供給することで処理槽８１の上方から貯留した液面上にミストを噴霧する噴霧手段５１とを備えている。従って、第１の実施形態では、噴霧手段５１を外槽３２に設置して処理槽８１の内部に突出しないように設けているため、基板の出し入れの邪魔になることなく配置でき、処理槽８１を小型化することが可能になる。
【００１６】
ここで、処理槽８１には、図１及び図２に示すように、純水を供給する供給管８４−１と、純水を排水するドレイン管８６−１とが各々接続されている。この供給管８４−１は、純水供給弁８４−２を介して処理槽８１内の左右対称に設置されている純水供給ノズル８４−３に接続している。また、ドレイン管８６−１は、純水を排水するためのドレイン弁８６−２、ドレインバイパス管８７−１、ドレインバイパス弁８７−２、ドレインポンプ８８を各々接続している。従って、ドレイン管８６−１は、処理槽８１から純水を排液して基板１（図２参照）を液面上に露出させる場合、この基板１の形状によらずドレインポンプ８８により純水を常に一定の流量で排液して徐々に露出できるように設けている。このドレイン管８６−１には、処理槽８１の上方開口部外周に設置されているオーバーフロードレイン槽８２−１から純水を排水するオーバーフロードレイン管８２−２を設けて接続している。
【００１７】
また、外槽３２は、処理槽８１の外周と上部とに覆設して底面を開放（図２参照）することによって、処理槽８１との間の空間に常に新鮮な水溶性有機溶剤ミスト及び高温不活性ガスを処理槽８１の上方から供給するとともに、この底面から余剰な水溶性有機溶剤ミスト及び高温不活性ガスを排出できるように形成している。この際、外槽３２内には、左右対称に一対もしくは複数対設置された噴霧手段５１により水溶性有機溶剤（例えば、イソプロピルアルコール：以下、ＩＰＡと称す。）ミストを噴霧し、この上部に同じく左右対称に設置された噴射手段４１により温調された不活性ガス（例えば、窒素ガス）を噴射する。
【００１８】
ここで、例えば、噴霧手段５１にＩＰＡを供給する場合、図２に示したように、まず、噴霧手段５１に接続した加圧タンク６１を設け、この加圧タンク６１に接続した加圧タンクＩＰＡ供給管６６の加圧タンクＩＰＡ供給弁６７と、加圧タンク圧抜管６２の加圧タンク圧抜弁６３とを開いた状態にすることでＩＰＡを供給し、図示されていない処理槽８１内の液面センサに達したところで加圧タンクＩＰＡ供給弁６７及び加圧タンク圧抜弁６３を閉じる。
【００１９】
次に、加圧タンク６１内にタンク加圧用の不活性ガス（タンク加圧用Ｎ_２：窒素ガス）を加圧タンク窒素ガス供給管６４から加圧タンク窒素ガス供給弁６５を開いて供給する。この状態でＩＰＡ供給弁５５を開けば、加圧タンク６１内のＩＰＡは圧送によりＩＰＡ供給管５４を経て噴霧手段５１に到達する。また、噴霧手段５１には、窒素ガス供給弁５３を開くことで窒素ガス供給管５２を経て不活性ガス（窒素ガス）が供給される。これにより噴霧手段５１は、ＩＰＡと窒素ガスとを内部で混合してミスト化し、ＩＰＡミスト５６として噴霧できる。
【００２０】
一方、噴射手段４１に高温不活性ガス（窒素ガス）を供給する場合、図２に示したように、噴射手段４１に窒素ガスを加熱する加熱ヒータ４４と高温窒素ガス供給弁４３とを有した高温窒素ガス供給管４２を接続することで高温の窒素ガスを供給している。この高温不活性ガスは、好ましくは、加熱ヒータ４４により前述したＩＰＡなどの水溶性有機溶剤の沸点以上の温度にして使用することが望ましい。
【００２１】
ところで、水溶性有機溶剤ミストを噴霧する噴霧手段５１は、図３及び図４に示すように、処理槽８１外で水溶性有機溶剤及び不活性ガスを各々供給して噴射するＩＰＡ噴射孔１０２及び窒素ガス噴射孔１０３を備えた気液混合チップ１０４と、この気液混合チップ１０４の噴射孔１０２、１０３をドーム状に覆って内部の空間で混合してミスト化するとともにドーム状の外壁に貫通する複数の穴１０１を開口してミストを噴霧するノズルカバー１０７とを備えている。
【００２２】
ここで、噴霧手段５１は、図３に示したように、気液混合チップ１０４に窒素（Ｎ_２）ガスを供給する窒素ガス供給管１０６と、この窒素ガス供給管１０６の横から突き刺すようにして設置されたＩＰＡを供給するＩＰＡ供給管１０５とを気液混合チップ１０４に各々設けることで、ＩＰＡ噴射孔１０２及び窒素ガス噴射孔１０３を形成している。尚、気液混合チップ１０４には、図４に示したように、中央に一箇所だけＩＰＡ噴射孔１０２があり、この外周に複数開口する窒素ガス噴射孔１０３が形成されている。このような構造の噴霧手段５１は、窒素ガス供給管１０６から供給された窒素ガスと、ＩＰＡ供給管１０５から供給されるＩＰＡとを、それぞれ気液混合チップ１０４の窒素ガス噴射孔１０３及びＩＰＡ噴射孔１０２に供給し、ノズルカバー１０７内で衝突させてミスト化することで穴１０１から噴霧している。従って、噴霧手段５１は、図１６に示した従来技術とは異なり、ノズルカバー１０７内で一旦窒素ガスとＩＰＡとを衝突させてミスト化して穴１０１から噴霧するため、ミストの大きさを自由に調節でき効果的な乾燥工程を実現することができる。
【００２３】
また、基板１は、図２に示したように、カセット２に複数枚収納して処理槽８１内にバッチ式に投入されて乾燥処理する。このカセット２は、処理槽８１内に図示されいない所定の搬送手段により直接投入することで設置される。また、処理槽８１には、基板１をカセット２により投入した際、基板１が液面上に露出せず、且つカセット２に接触しない位置に保持するための保持手段８３を設けている。この保持手段８３は、図５に示すように、基板１が自立して複数配列する方向に下部でリブ状に延在する複数（図５では３本）の保持板８３−２、８３−３、８３−４を一体に設けている。また、保持手段８３は、図６に示すように、保持板８３−２〜４に基板１の下端が接触して保持できる歯形状の溝部８３−５を有し、この溝部８３−５の形状がＶ型またはＹ型（図６ではＹ型）になるように切り欠いている。また、保持手段８３は、図６に示した保持板の溝部８３−５中に残ってしまう純水を排液するために吸引ポンプ８０を有した残液吸引孔８９が溝部８３−５の底部に接続されている。
【００２４】
このように形成された本発明による基板乾燥装置の第１実施形態を用いて基板乾燥操作を行う場合、まず、図２に示した供給弁８４−２を開き、供給管８４−１から処理槽８１へ純水を図示していない液面センサの位置まで供給した後、供給弁８４−２を閉じる。次に、外槽３２に有した天蓋３１を開き、純水に満たされた処理槽８１内に基板１をセットする。この際、基板１は、カセット２に複数収納し、図示していない搬送手段により直接処理槽８１内に下降させることで投入する。そして、基板１は、処理槽８１の下降途中でカセット２に接触せずに自立するため、くし歯状の保持手段８３に載置され、空になったカセット２は処理槽８１の最深部まで下降させた状態にセットされる。その後、図示していない搬送手段を処理槽８１及び外槽３２から離脱させ、天蓋３１を閉じることで作動準備が完了する。
【００２５】
次に、供給弁８４−２を再び開き、供給管８４−１から再び処理槽８１へ純水を供給してアップフローリンスを行う。従って、処理槽８１では、純水を貯留して洗浄などの基板処理を行った後、基板１を液面上に露出させて乾燥処理を行うことで同時に洗浄と乾燥とを処理可能にしている。この際、処理槽８１の上方開口部から溢れた純水は、オーバーフロードレイン槽８２−１からオーバーフロードレイン管を経てドレインされる。純水供給弁８４−２を閉じてアップフローリンスを終了した後、純水が処理槽８１の上方開口部まで満たされている状態で、噴霧手段５１からＩＰＡミスト５６を噴射すると同時、又は１分以内にドレイン弁８６−２を開き、ドレインポンプ８８を動作させて、１〜５ｍｍ／ｓｅｃ程度の引き下げ速度で処理槽８１内の液面が下がるように純水をドレイン管８６−１を介してドレインする。これにより基板１は、ＩＰＡミストの噴霧によるマランゴニ効果及び付着した純水の置換（蒸発）により表面から水分を排除する。
【００２６】
このとき、液面が基板１の直径を通過するときでも、上端・下端を通過するときでも同じ引き下げ速度になるようにドレインポンプ８８の吸引量に経時変化を持たせて調整する。又、基板１と保持手段８３の溝部８３−５とが純水中から完全に露出したら、保持手段８３の溝部８３−５に残った純水を図６で示した底部にある残液吸引孔８９より吸引ポンプ８０を用いて吸引する。同時に、図２に示したドレインポンプ８８の空運転防止のため、ドレインポンプ８８を停止させ、ドレインバイパス弁８７−２を開いてドレインバイパス管８７−１より処理槽８１に残っている純水をドレインする。
【００２７】
また、処理槽８１から純水が完全にドレインしたと同時、又は２分以内にＩＰＡ供給弁５５及び窒素ガス供給弁５３を閉じ、高温窒素ガス供給弁４３を開いて、加熱ヒータ４４で１３０℃前後に温調された窒素ガスを、高温窒素ガス供給管４２を介して噴射手段４１から数分噴射する。これにより基板１及びカセット２が完全に乾燥した後、天蓋３１を開き、搬送手段により処理槽８１の最深部にあるカセット２を上昇させて、静止している保持手段８３上の基板１を下方からカセット２のスリットですくい上げるようにしてカセット２に戻す。更に搬送手段を上昇させて、処理槽８１からカセット２ごと基板１を取り出し、天蓋３１を閉じることで乾燥処理が終了する。
【００２８】
このように本発明による基板乾燥装置の第１実施形態によると、図２に示したように噴霧手段５１を外槽３２に設置して処理槽８１の内部に突出しないように設けているため、基板１の出し入れの邪魔になることなく配置でき、処理槽８１を小型化することが可能になる。
また、第１実施形態によると、図３に示したように、ノズルカバー１０７内の空間で窒素ガスとＩＰＡとを衝突させてミスト化し、更に穴１０１の口径を調整して所望のミストを噴霧する構造のため、ミストの大きさを自由に調節でき効果的な乾燥工程を実現することができる。
【００２９】
ここで、保持手段８３は、図６に示すように、保持板８３−２〜４の溝部８３−５形状をＶ型またはＹ型に形成した実施例を詳細に説明したが、これに限定されるものではなく凹凸を交互に設けて保持しても良い。図７は、このような凹凸を設けて保持する保持手段の他の実施例を示す図である。また、図８は、図７に示した保持手段８３を上面から見た上面図である。また、図９は、図８に示した凸部８３−５ａ及び凹部８３−５ｂの詳細を示す斜視図である。また、図１０は、図９に示した保持手段８３を側面から見た側面図である。
【００３０】
図７に示すように、保持手段の他の実施例は、図５に示した保持手段と同様に、基板１が自立して複数配列する方向に下部からリブ状に延在する３本の保持板８３−２、８３−３、８３−４を一体に設けている。ここで、保持板８３−２、８３−３、８３−４は、３本に限定されるものではなく、複数本設けても良い。また、保持手段８３は、図５に示した保持手段とは異なり、リブ状に延在する保持板８３−２〜４に基板１の下端が接触して保持するように凸凹を複数交互に配置（図９参照）している。即ち、保持手段８３は、図８に示すように、垂直に突出する凸部８３−５ａと凹状の凹部８３−５ｂとを複数交互に配置してリブ状に延在する３本の保持板８３−２〜４を一体に設け、このうち１本の保持板８３−３が凹凸の配列をずらして配置されている。これにより保持手段８３は、図９に示すように、ずらした保持板８３−３の凸部８３−５ａが基板１の片側面を保持し、一方のずらしていない保持板８３−２、８３−４の凸部８３−５ａが基板１の他の片側面を保持して挟持するように設けている。
【００３１】
この際、保持板８３−２〜４の凸部８３−５ａ間、即ち、凹部８３−５ｂの図９に示した隙間Ｂは、垂直方向に広い幅を有する溝形状に形成している。この隙間Ｂは、好ましくは、基板１の厚さに対して１．５〜３倍の幅に形成することが望ましい。さらに、各保持板８３−２〜４は、図９に示した厚み（幅）Ｃが２ｍｍ以下に形成されており、好ましくは、０．５ｍｍ〜１０ｍｍに設けることが望ましい。これにより保持板８３−２〜４は、保持手段８３が純水中から露出したときの隙間Ｂの残液量が少なく、且つ、乾燥時間を短縮できる。そして、この保持板８３−２〜４は、基板１が接触する凸部８３−５ａ及び凹部８３−５ｂの材質がＰＦＡ、ＰＶＤＦ、ＰＴＦＥ、ＰＥＥＫいずれかを用いて形成されている。このような保持手段の他の実施例によると、図６に示した保持手段に比べて基板１を保持する際に凸部８３−５ａが接触する接触面が少ないため、隙間Ｂでの残液量が少なく、乾燥時間を短縮することができる。
【００３２】
また、図２に示した純水の供給排出部Ａにおいて、処理槽８１に純水を直接供給する実施例を詳細に説明したが、これに限定されるものではなく、例えば、暖めた温純水、或いは薬液を混合した純水（処理液）を処理槽に供給することも可能である。図１１は、このような暖めた温純水を供給する供給排出部の他の実施例を示す図である。また、図１２は、薬液を混合した純水を供給する供給排出部の更なる他の実施例を示す図である。ここで、図１１に示した供給排出部において、純水ヒータ８５−３以外は、全て図２に示した供給排出部Ａと同じ構成要素であり、同じ構成要素には同一符号を記載するとともに、重複する説明は省略する。
【００３３】
図１１に示すように、暖めた温純水を供給する供給排出部の他の実施例は、図２に示した供給排出部Ａとほぼ同様の構成だが、処理槽８１に純水を供給する供給管８４−１に供給弁８４−２とともにヒータ８５−３を接続して備えている。ここで、ヒータ８５−３は、好ましくは、処理槽８１内で基板１を露出させる直前の純水温度が２０℃〜７０℃の温純水になるように暖めることが望ましい。詳しくは、例えば、ヒータ８５−３により約６０℃に温調された温純水を供給弁８４−２を開いて供給管８５−１から処理槽８１に供給し、図示されていない液面センサの位置に達したところで供給弁８４−２を閉じて供給を終了する。その後、図２に示した供給排出部Ａと同様の操作により処理される。
【００３４】
このように、温純水を供給する供給排出部の他の実施例によると、処理槽８１に供給弁８４−２を開閉することで純水を供給するため、図２に示した供給排出部Ａと同様の効果を得ることができる。また、基板１を純水から露出させたとき、基板１の温度は温純水により暖められているので、基板１上に付着している純水を置換するＩＰＡの蒸発を促進させる効果が期待できる。
【００３５】
また、図１２に示すように、薬液を混合した純水を供給する供給排出部の更なる他の実施例は、供給管８４−１が処理液混合撹拌管９４−３を介して純水供給管９５−６とフッ酸供給管９６−６とに各々接続されている。ここで、処理液混合撹拌管９４−３には、フッ酸濃度計９１、薬液撹拌器９２、薬液混合弁９３を接続しており供給された薬液と純水とを混合及び攪拌している。また、処理液混合撹拌管９４−３は、薬液混合弁９３を介して純水供給管９５−６とフッ酸供給管９６−６とに分岐している。この純水供給管９５−６には、純水流量計９５−１、流量制御弁９５−２、純水供給弁９５−５を接続して純水の供給量を調整している。また、流量制御弁９５−２には、圧縮エアー供給管９５−４が接続され、精密レギュレータ９５−３を介して圧縮エアーの圧力を調整している。一方、フッ酸供給管９６−６には、フッ酸流量計９６−１、流量制御弁９６−２、フッ酸供給弁９６−５を接続して薬液の供給量を調整している。また、流量制御弁９６−２には、圧縮エアー供給管９６−４が接続され、精密レギュレータ９６−３を介して圧縮エアーの圧力を調整している。
【００３６】
そして、この処理液混合撹拌管９４−３は、三方弁９８により供給管８４−１に接続しているとともに、この三方弁９８から処理槽８１の処理液を排出するドレイン管８６−１に処理液ドレイン管９４−２を介して接続している。尚、ドレイン管８６−１は、図２に示した供給排出部Ａと同様に、ドレインインバイパス管８７−１を介して接続したドレインバイパス弁８７−２と、ドレイン弁８６−２とを各々備えている。
【００３７】
このような構成からなる供給排出部の更なる他の実施例を使用する場合、例えば、ＤＨＦ濃度を１：２００とすると、純水流量２０Ｌ／ｍｉｎ、フッ酸流量０．１Ｌ／ｍｉｎとなるように精密レギュレータ９５−３、９６−３の圧縮エアー圧力を調整して流量制御弁９５−２、９６−２への供給量を調節する。次に、三方弁９８により処理液ドレイン管９４−２の方に処理液が流れる状態で純水供給弁９５−５及びフッ酸供給弁９６−５を開いて、純水とフッ酸とを供給して薬液混合弁９３で混合させ、次に薬液撹拌器９２で流れの力で撹拌させ、更にフッ酸濃度計９１でフッ酸濃度を測定する。このとき、フッ酸濃度が設定濃度に達するまでは処理液を処理液ドレイン管９４−２に流し、設定濃度に達した場合に三方弁９８を供給管８４−１に切り替えて処理槽８１に供給する。そして、処理槽８１では図示していない液面センサの位置に達したところで三方弁９８を処理液ドレイン管９４−２に切り替えるとともに、純水供給弁９５−５及びフッ酸供給弁９６−５を閉じて、供給を終了させる。次に、フッ酸によるエッチング処理を行い、その後、フッ酸をアップフローリンスにより純水に置換して、図２に示した供給排出部Ａと同様の操作により処理する。
【００３８】
このように供給排出部の更なる他の実施例によると、処理槽８１に三方弁９８を介して純水を供給できるため、図２に示した供給排出部Ａと同様の効果を得ることができるとともに、この純水に薬液（フッ酸）を混合してエッチング処理を行うことで、基板の品質をより向上させることができる。
【００３９】
ところで、図２に示した第１の実施形態では、純水を貯留した処理槽８１内に基板１を複数収納したカセットを図示されていない搬送手段により直接搬入するため、この搬送手段により処理槽８１内の純水が汚染されて基板１にパーティクルなどの汚染物質が付着してしまう可能性があった。そこで、処理槽８１内にカセットを搬入及び搬出するためのカセットエレベータを設けることで基板１の汚染を防止する基板乾燥装置がある。図１３は、このようなカセットエレベータを設けた本発明による基板乾燥装置の第２実施形態の概略構成を示す図である。また、図１４は、図１３に示した基板乾燥装置の詳細な構成を示す構成図である。ここで、第２実施形態では、図１３及び１４に示したカセットエレベータ７１以外、図２に示した第１実施形態と同様の構成要素であり、この同じ構成要素には同一の符号を記載するとともに、重複する説明は省略する。
【００４０】
図１３に示すように、本発明による基板乾燥装置の第２実施形態は、図２に示した第１実施形態とほぼ構成は同じだが、外槽３２と処理槽８１との間に基板を複数収納したカセットを載置して昇降させるカセットエレベータ７１を設置している。このカセットエレベータ７１は、図１４に示すように、処理槽８１の近傍に昇降機構７２を有して処理槽８１に貯留した純水から基板１を昇降させて取り出せるように配置している。
【００４１】
このように形成された本発明による基板乾燥装置の第２実施形態を使用する場合、まず、供給弁８４−２を開き、供給管８４−１から処理槽８１へ純水を図示していない液面センサの位置まで供給した後、供給弁８４−２を閉じる。次に、外槽３２に備えた天蓋３１を開き、純水を満した処理槽８１の液面上方までカセットエレベータ７１を昇降機構７２により上昇させ、このカセットエレベータ７１に基板１を複数セットしたカセット２を載せた後に下降させて処理槽８１に投入する。この下降途中で基板１がカセット２に接触させずに自立させるため、くし歯状の保持手段８３に載せて、空になったカセット２だけをカセットエレベータ７１で処理槽８１の最深部まで下降させて天蓋３１を閉じる。次に、供給弁８４−２を再び開き、供給管８４−１から再び処理槽８１へ純水を供給してアップフローリンスを行う。このとき処理槽８１の上方開口部から溢れた純水はオーバーフロードレイン槽８２−１からオーバーフロードレイン管８２−２を経てドレインされる。
【００４２】
供給弁８４−２を閉じてアップフローリンス終了後、純水が処理槽８１の上方開口部まで満たされている状態で、噴霧手段５１からＩＰＡミスト５６を噴霧すると同時又は１分以内に、ドレイン弁８６−２を開いてドレインポンプ８８を動作させ、１〜５ｍｍ／ｓｅｃ程度の引き下げ速度で処理槽８１内の液面が下がるように純水をドレイン管８６−１を介してドレインする。このとき、液面が基板１の直径を通過するときでも、上端・下端を通過するときでも同じ引き下げ速度になるようにドレインポンプ８８の吸引量に経時変化を持たせて調整する。また、基板１と保持手段８３の図６に示した溝部８３−５とが純水中から完全に露出したら、保持手段８３の溝部８３−５に残った純水を溝底部にある残液吸引管８９より残液吸引ポンプ８０を用いて吸引する。同時に、図１４に示したドレインポンプ８８の空運転防止のため停止させ、ドレインバイパス弁８７−２を開いてドレインバイパス管８７−１より処理槽８１に残っている純水をドレインする。この処理槽８１から純水が完全にドレインしたと同時又は２分以内に、ＩＰＡ供給弁５５及び窒素ガス供給弁５３を閉じ、高温窒素ガス供給弁４３を開いて、加熱ヒータ４４で１３０℃前後に温調された窒素ガスを、高温窒素ガス供給管４２を介して、噴射手段４１から数分噴射する。
【００４３】
そして、基板１及びカセット２が完全に乾燥した後、天蓋３１を開き、カセットエレベータ７１を上昇させて、静止している保持手段８３上の基板１をカセット２のスリットですくい上げるようにしてカセット２に戻す。更にカセットエレベータ７１を処理槽８１の上方開口部上方まで上昇させて、基板１がセットされたカセット２を所定の搬送手段により取り出す。
【００４４】
このように本発明による基板乾燥装置の第２実施形態によると、基板１を複数収納したカセット２を所定の搬送手段ではなくカセットエレベータ７１に載置して処理槽８１内に浸漬させるため、処理槽８１内が汚染されることなく常に清浄に維持されて基板１の汚染を最小限に抑えることができる。
【００４５】
また、図２及び１４に示した第１及び第２の実施形態において基板１を乾燥する際に処理槽８１の純水をドレイン管８６−１から排出しながら乾燥させる実施の形態を説明したが、これに限定されるものではなく、例えば、基板１（カセット２）を処理槽８１内から上昇させて乾燥させる基板乾燥装置がある。図１５は、このような基板１を上昇させて乾燥させる本発明による基板乾燥装置の第３実施形態を示す構成図である。尚、図１５に示した外槽３２、カセットエレベータ７１、保持手段８３、及びドレイン管８６−１以外は、全て図２に示した基板乾燥装置と同様の構成要素であり、同じ構成要素には同一の符号を記載するとともに、重複する説明は省略する。
【００４６】
図１５に示すように、本発明による基板乾燥装置の第３実施形態は、カセットエレベータ７１とともに保持手段８３が処理槽８１の液面上まで昇降可能に設けることで、この保持手段８３により基板１を上昇させて乾燥処理できるように形成している。この第３の実施形態では、カセットエレベータ７１と保持手段８３とが上部に上昇するための空間を設けるために外槽３２が垂直方向に長く延在しているとともに、保持手段８３により基板１を昇降させて乾燥することでドレイン管８６−１にドレインポンプを設けて排出量を調整する必要がなくなる。
【００４７】
このように形成された本発明による基板乾燥装置の第３実施形態を使用する場合、まず、純水で満たされた処理槽８１内に基板１を搬入し、この基板１がカセット２に接触せずに保持手段８３で保持され、カセット２が処理槽８１の最深部に待機している状態（図２参照）において、噴霧手段５１からＩＰＡミストの噴霧を開始すると同時に、昇降機構８３−１により保持手段８３が保持した基板１を１〜５ｍｍ／ｓｅｃの速度で上昇させる。このとき、基板１と保持手段８３の溝部８３−５（図６参照）とが純水中から完全に露出したら、保持手段８３の溝部８３−５に残った純水を溝底部にある残液吸引管８９より残液吸引ポンプ８０を用いて吸引する。同時にドレイン弁８６−２を開いて処理槽８１内の純水を排水する。
【００４８】
そして、処理槽８１から純水が完全にドレインしたと同時又は２分以内に、ＩＰＡ供給弁５５及び窒素ガス供給弁５３を閉じてＩＰＡミストの供給を停止する。その後、高温窒素ガス供給弁４３を開いて、加熱ヒータ４４で１３０℃前後に温調された窒素ガスが高温窒素ガス供給管４２を介して噴射手段４１から数分噴射する。これにより基板１及びカセット２が完全に乾燥した後、天蓋３１を開き、保持手段８３を昇降機構８３−１により下降させ、静止しているカセットエレベータ７１上のカセット２のスリットに基板１を落とし込むようにして戻した後、基板１をセットしたカセット２を所定の搬送手段により取り出す。
このように、本発明による基板乾燥装置の第３実施形態によると、保持手段８３が基板１を保持して上昇させることで乾燥処理を行うため、処理槽８１の純水をドレインポンプにより調整して排出する必要がなくなり操作が簡単になる。
【００４９】
以上、本発明による基板乾燥装置の実施の形態を詳細に説明したが、本発明は前述した実施の形態に限定されるものではなく、その要旨を逸脱しない範囲で変更可能である。
例えば、水溶性有機溶剤にＩＰＡを用いた実施例を説明したが、これに限定されるものではなく、例えば、イソプロパノール、２−プロパノール、イソプロピルアルコール、エタノール、メタノール、ブチルアルコールなどを、それぞれ単独又は混合して使用することが可能である。
また、不活性ガスに窒素ガスを用いた実施例を説明したが、これに限定されるものではなく、例えば、アルゴン、ヘリウムなどを、それぞれ単独又は混合して使用することもできる。
また、純水にフッ酸を混合した処理液を用いる実施例（図１２参照）を説明したが、これに限定されるものではなく、例えば、フッ酸水及び純水を混合させた希フッ酸水、過酸化水素水、アンモニア水、アンモニア水及び過酸化水素水並びに純水を混合させたＡＰＭ、塩酸水、塩酸水及び過酸化水素水並びに純水を混合させたＨＰＭであり、それぞれ単独又は混合して使用することもできる。
【００５０】
【発明の効果】
このように本発明による基板乾燥装置によれば、噴霧手段を外槽に設置して処理槽の内部に突出しないように設けているため、基板の出し入れの邪魔になることなく配置でき、処理槽を小型化することが可能になる。
また、本発明による基板乾燥装置によれば、処理槽外のノズルカバー内の空間で不活性ガスと水溶性有機溶剤とを衝突させてミスト化した後、この水溶性有機溶剤ミストを噴霧手段の穴を調整して噴霧する構造のため、ミストの大きさを自由に調節でき効果的な乾燥工程を実現することができる。
【図面の簡単な説明】
【図１】本発明による基板乾燥装置の第１実施形態の概略構成を示す図。
【図２】図１に示した基板乾燥装置の詳細な構成を示す構成図。
【図３】図１に示した噴霧手段の内部構造を示す図
【図４】図１に示した気液混合チップを示す図。
【図５】図１に示した保持手段を示す図。
【図６】図５に示した保持板を側面から見た形状を示す図。
【図７】図１に示した保持手段の他の実施例を示す図。
【図８】図７に示した保持手段を上面から見た上面図。
【図９】図８に示した凸部及び凹部の詳細を示す斜視図。
【図１０】図９に示した保持手段を側面から見た側面図。
【図１１】暖めた温純水を供給する供給排出部の他の実施例を示す図。
【図１２】薬液を混合した純水を供給する供給排出部の更なる他の実施例を示す図。
【図１３】本発明による基板乾燥装置の第２実施形態の概略構成を示す図。
【図１４】図１３に示した基板乾燥装置の詳細な構成を示す構成図。
【図１５】本発明による基板乾燥装置の第３実施形態を示す構成図。
【図１６】従来の基板乾燥装置の一実施形態を示す構成図。
【図１７】図１６に示した噴霧手段の内部構造を示す図。
【符号の説明】
１基板
２カセット
３１天蓋
３２外槽
４１噴射手段
４２高温窒素ガス供給管
４４加圧ヒータ
５１噴霧手段
５４ＩＰＡ供給管
６１加圧タンク
６４加圧タンク窒素ガス供給管
６６加圧タンクＩＰＡ供給管
８１処理槽
８２−１オーバーフロードレイン槽
８３保持手段
８４−１供給管
８６−１ドレイン管
８８ドレインポンプ[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a substrate drying apparatus, and more particularly, to a flat plate such as an LCD substrate or a semiconductor wafer utilizing a meniscus due to surface tension of water and a Marangoni effect by a mist containing a water-soluble organic solvent that is easily soluble in water. TECHNICAL FIELD The present invention relates to a substrate drying apparatus for completely drying a substrate in a shape of a droplet without producing a trace of water droplets on the surface thereof.
[0002]
[Prior art]
[Patent Document 1]
JP 2000-223466 A
[0003]
2. Description of the Related Art Conventionally, as a substrate drying apparatus, an apparatus that can completely dry a flat substrate such as an LCD substrate or a semiconductor wafer after cleaning by using the Marangoni effect without causing water droplet marks on the surface thereof is well known. A conventional substrate drying apparatus using such a Marangoni effect is, for example, a nitrogen gas and a water-soluble organic solvent in a meniscus due to surface tension generated when a substrate that is immersed by storing pure water in a processing tank is pulled up. By spraying the vapor mixed with the IPA gas, the surface tension is reduced from the upper end of the meniscus, and a force (Marangoni effect) of drawing back to the water surface side is generated.
[0004]
However, in the substrate drying apparatus using steam, the consumption of IPA increases because the water-soluble organic solvent IPA is vaporized and supplied, and a heating source for vaporizing the IPA is also required. . Therefore, in a conventional substrate drying apparatus, there is an apparatus that sprays a meniscus of a substrate by ejecting nitrogen gas without vaporizing the IPA liquid to form a mist (for example, Patent Document 1). FIG. 16 is a configuration diagram showing an embodiment of a conventional substrate drying apparatus using such a mist. FIG. 17 is a diagram showing the internal structure of the spray means 151 shown in FIG.
[0005]
As shown in FIG. 16, one embodiment of a conventional substrate drying apparatus using a mist includes a processing tank 181 storing pure water for immersing a cleaned wafer 1 supported on a carrier (not shown), and a processing tank 181 storing the pure water. A nitrogen gas is injected into the space D on the liquid surface in the liquid 181, and a liquid isopropyl alcohol (hereinafter simply referred to as IPA) is injected at a temperature higher than the temperature of the wafer 1 (for example, normal temperature) by the nitrogen gas. And spray means 151 for spraying the mist-like IPA into the space D.
[0006]
Here, as shown in FIG. 17, the spraying means 151 includes a nitrogen gas passage 151a and a liquid-phase IPA passage 151d which respectively penetrate along a long body made of fluororesin, and a liquid phase IPA passage 151d. A large number of thin nitrogen gas ejection passages 151b having ejection holes 151c extending from the passage 151a and opening between the plurality of wafers 1 are provided, and the opening end of the nitrogen gas ejection passage 151b extending from the IPA passage 151d is ejected. A large number of thin IPA ejection passages 151e having ejection holes 151f opened toward the holes 151c are provided. Therefore, the spraying means 151 makes the mist-like IPA space by injecting the nitrogen gas from the injection hole 151c of the nitrogen gas ejection passage 151a and simultaneously injecting the liquid phase IPA from the ejection hole 151f of the IPA ejection passage 151d. It can be sprayed between the wafers 1 in D.
[0007]
Referring again to FIG. 16, nitrogen (N ₂ The gas is supplied at normal temperature or the temperature of the wafer 1, and is processed through the pressure reducing valve 153-1, the first supply valve 153-2, the flow meter 153-3, and the manual valves 153-4 and 153-5. Are supplied to the spraying means 151 arranged on the left and right of the inside. Further, the IPA sends another nitrogen gas under pressure into the pressurized tank 161 via the pressure reducing valve 165-1 and the second supply valve 165-2, and the pressure of the nitrogen gas in the pressurized tank 161 is changed by the pressure of the nitrogen gas. The IPA liquid is supplied to the spraying means 181 disposed on the left and right inside the processing tank 181 via the third supply valve 155-1, the flow meter 155-2, and the manual valves 155-3 and 155-4. In addition, 163-1 is a pressure relief valve for a pressurized tank.
[0008]
The treatment tank 181 has an exhaust pipe 182-1 for maintaining a constant pressure via a manual valve 182-3 and a fourth supply valve 182-2, and a drain for discharging pure water via a drain valve 186-2. Tube 186-2. Here, the first supply valve 153-2, the second supply valve 165-2, the third supply valve 155-1, the fourth supply valve 182-2, and the drain valve 186-2 are connected to the control device 140. Based on a predetermined program, the flow rates of the nitrogen gas and the liquid phase IPA automatically supplied into the processing tank 181, that is, the spray state of the IPA mist, and the flow rate from the space D in the processing tank 181. The operation of the exhaust amount, the pure water discharge amount, and the like can be controlled.
[0009]
In one embodiment of the conventional substrate drying apparatus having such a configuration, pure water is stored in the processing tank 181 and the wafer 1 is immersed, and then the pure water in the processing tank 181 is discharged or the wafer 1 is discharged. The wafer 1 is gradually exposed from the liquid level of the pure water by being raised in the processing tank 181. At this time, in the treatment tank 181, the spraying means 151 sprays IPA on both front and back surfaces of the wafer 1 in a mist state, that is, in a state where the IPA itself is floating alone in nitrogen gas instead of using nitrogen as a carrier. As a result, the IPA mist is uniformly supplied to the liquid surface of the pure water, and the Marangoni effect is generated, and the pure water adhering to the front and back surfaces of the wafer 1 is completely replaced by the mist-like IPA (evaporation). Dry both sides.
[0010]
As described above, in one embodiment of the conventional substrate drying apparatus, IPA, which is a water-soluble organic solvent, is converted into a mist instead of being vaporized. At the same time, the drying effect was further improved by the Marangoni effect and the replacement (evaporation) of the IPA mist.
[0011]
[Problems to be solved by the invention]
However, in the conventional substrate drying apparatus, the spray means 151 shown in FIG. 17 has a structure in which the liquid-phase water-soluble organic solvent (IPA or the like) supplied to the ejection hole 151f is mist-formed by spraying nitrogen gas. There is a problem that it is difficult to freely adjust the size of the frame. Further, since the spraying units 151 are arranged on both side surfaces in the processing tank 181 shown in FIG. 16, the spraying means 151 hinders the loading and unloading of the wafer 1 and the size of the processing tank 181 itself becomes large. was there.
An object of the present invention is to provide a substrate drying apparatus capable of solving such problems and adjusting the size of a mist caused by a water-soluble organic solvent and reducing the size of the entire apparatus without disposing a mist spraying apparatus in a drying chamber. I do.
[0012]
[Means for Solving the Problems]
In order to solve the above-described problems, a substrate drying apparatus according to the present invention has a processing tank for storing pure water and immersing the substrate, and a cover for covering the outer periphery and the upper portion of the processing tank to cover the upper surface with the substrate. An outer tank having an openable / closable canopy to be carried in, an injection means installed in the outer tank to inject high-temperature inert gas onto a liquid surface stored from above the internal processing tank, and an injection means installed in the outer tank in the vicinity of the injection means. Spraying means for mixing the water-soluble organic solvent and the inert gas outside the processing tank, forming a mist, and supplying the mist to spray the mist on the liquid surface stored from above the processing tank. By draining water or raising the substrate, the substrate is exposed on the liquid surface, and the Marangoni effect by spraying mist and replacing the attached pure water, and completely evaporating the substrate by jetting high-temperature inert gas, completely removes the substrate. Provide to dry.
[0013]
Here, in the case where pure water is drained to expose the substrate, the processing tank is preferably provided with a vacuum pump that constantly drains the pure water at a constant flow rate regardless of the shape of the substrate. Further, the pure water is preferably warm pure water having a temperature of 20 ° C. to 70 ° C. immediately before exposing the substrate. Further, it is preferable that the injection means be used with the temperature of the high-temperature inert gas being equal to or higher than the boiling point of the water-soluble organic solvent. In addition, the outer tank is always provided with the fresh water-soluble organic solvent mist and the high-temperature inert gas from above the processing tank by covering the outer periphery and the upper part of the processing tank and opening the bottom surface. It is preferable to discharge excess water-soluble organic solvent mist and high-temperature inert gas from the mist. Further, it is preferable that a plurality of substrates are stored in a cassette, put into a processing tank in a batch system, and subjected to a drying process. Further, it is preferable that the cassette is installed or removed by raising the cassette elevator provided in the processing tank above the liquid level and by a predetermined transport means, and is lowered when the cassette is installed in the cassette elevator and is preferably introduced into the processing tank. . Further, as another embodiment of the cassette, it is preferable to directly load the cassette into the processing tank by a predetermined transport means. Further, it is preferable that the processing tank is provided with holding means for holding the substrate at a position where the substrate is not exposed on the liquid surface and does not come into contact with the cassette when the substrate is loaded by the cassette. Further, the holding means integrally has a plurality of holding plates extending in a rib shape at a lower portion in a direction in which the plurality of substrates are independently arranged, and has a groove capable of holding the lower end of the substrate in contact with the holding plate. It is preferable that the shape of the groove is V-shaped or Y-shaped, and that the device further include a residual liquid suction hole and a suction pump capable of sucking the liquid remaining in the groove. Further, in another embodiment of the holding means, in order to make the substrate self-supporting, a plurality of holding plates extending in a rib shape by vertically arranging a plurality of projections and recesses alternately are provided integrally, and a part of this is provided. The holding plate of the holding plate is arranged with the arrangement of the unevenness shifted, the projection of the shifted holding plate holds one side of the substrate, and the projection of the unshifted holding plate holds the other side of the substrate. It is preferable to provide it so as to sandwich it. Further, it is preferable that the holding means be provided with a plurality of holding plates each having a uniform thickness of 0.5 mm to 10 mm. It is preferable that the holding plate uses PFA, PVDF, PTFE, or PEEK as a material of the concave and convex portions with which the substrate contacts. In addition, when supplying pure water to the treatment tank, a chemical mixing valve is provided in a pure water supply pipe for supplying pure water, and the chemical concentration of at least one or more chemicals and pure water is adjusted with a flow meter. It is preferable that the processing liquid mixed and stirred in the pure water supply pipe can be supplied. In addition, a concentration meter shall be further provided in the pure water supply pipe to control the treatment liquid obtained by mixing and stirring the chemical solution and pure water until the concentration reaches the set concentration, and when the concentration reaches the set concentration, the supply into the treatment tank is started. Is preferred. The treatment liquid is diluted hydrofluoric acid water mixed with hydrofluoric acid water and pure water, hydrogen peroxide solution, ammonia water, ammonia water and hydrogen peroxide solution, and APM mixed with pure water, hydrochloric acid solution, hydrochloric acid solution. And a mixture of a hydrogen peroxide solution and pure water. It is preferable to use each of them alone or in combination. Further, in the processing tank, it is preferable to store only the processing liquid or pure water and perform substrate processing such as cleaning, and then expose the substrate to the liquid surface and perform drying processing. Further, the spraying means includes a gas-liquid mixing chip provided with an injection hole for supplying and jetting a water-soluble organic solvent and an inert gas, respectively, outside the processing tank, and covering the injection hole of the gas-liquid mixing chip in a dome shape. It is preferable to include a nozzle cover that mixes and forms a mist in the internal space and that opens a plurality of holes that penetrate the dome-shaped outer wall to spray the mist. The water-soluble organic solvents are isopropanol, 2-propanol, isopropyl alcohol, ethanol, methanol, and butyl alcohol, and are preferably used alone or in combination. The inert gas is nitrogen, argon, or helium, and it is preferable to use each alone or in combination.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, an embodiment of a substrate drying apparatus according to the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a diagram showing a schematic configuration of a first embodiment of a substrate drying apparatus according to the present invention. FIG. 2 is a configuration diagram showing a detailed configuration of the substrate drying apparatus shown in FIG. FIG. 3 is a view showing the internal structure of the spraying means 51 shown in FIG. FIG. 4 is a diagram showing the gas-liquid mixing chip 104 shown in FIG. FIG. 5 is a diagram showing the holding unit 83 shown in FIG. FIG. 6 is a diagram showing the shape of the holding plates 83-2 to 83 shown in FIG.
[0015]
As shown in FIG. 1, the first embodiment of the substrate drying apparatus according to the present invention differs from the prior art shown in FIG. 16 in that a processing tank 81 in which pure water is stored and a substrate is immersed, An outer tank 32 having an openable and closable canopy 31 for covering the outer periphery and the upper part thereof and carrying the substrate on the upper surface thereof, and a liquid surface installed in the outer tank 32 and stored from above the internal processing tank 81. An injection means 41 for injecting a high-temperature inert gas upward, and a water-soluble organic solvent (IPA) and an inert gas (N ₂ ) Is provided by spraying mist onto the liquid surface stored from above the processing tank 81 by mixing and supplying the mist. Therefore, in the first embodiment, since the spraying means 51 is provided in the outer tank 32 so as not to protrude into the processing tank 81, the spraying means 51 can be arranged without obstructing the loading and unloading of the substrate. Can be reduced in size.
[0016]
Here, as shown in FIG. 1 and FIG. 2, a supply pipe 84-1 for supplying pure water and a drain pipe 86-1 for draining pure water are connected to the processing tank 81, respectively. This supply pipe 84-1 is connected to a pure water supply nozzle 84-3 installed symmetrically in the processing tank 81 via a pure water supply valve 84-2. The drain pipe 86-1 is connected to a drain valve 86-2 for draining pure water, a drain bypass pipe 87-1, a drain bypass valve 87-2, and a drain pump 88. Therefore, when draining the pure water from the processing tank 81 to expose the substrate 1 (see FIG. 2) on the liquid surface, the drain pipe 86-1 uses the drain pump 88 regardless of the shape of the substrate 1. Is constantly drained at a constant flow rate so as to be gradually exposed. An overflow drain pipe 82-2 for draining pure water from an overflow drain tank 82-1 provided around the upper opening of the processing tank 81 is connected to the drain pipe 86-1.
[0017]
The outer tank 32 covers the outer periphery and the upper part of the processing tank 81 and opens the bottom surface (see FIG. 2), so that the space between the outer tank 32 and the processing tank 81 is always fresh water-soluble organic solvent mist and A high-temperature inert gas is supplied from above the processing tank 81, and excess water-soluble organic solvent mist and high-temperature inert gas are discharged from the bottom of the processing tank 81. At this time, a mist of a water-soluble organic solvent (for example, isopropyl alcohol; hereinafter, referred to as IPA) is sprayed into the outer tank 32 by a pair or a plurality of symmetrically arranged spraying means 51, and the upper part thereof is also sprayed. The inert gas (for example, nitrogen gas) whose temperature is controlled by the injection means 41 installed symmetrically is injected.
[0018]
Here, for example, when supplying IPA to the spraying means 51, as shown in FIG. 2, first, a pressurized tank 61 connected to the spraying means 51 is provided, and a pressurized tank IPA connected to the pressurized tank 61 is provided. The IPA is supplied by opening the pressurized tank IPA supply valve 67 of the supply pipe 66 and the pressurized tank depressurization valve 63 of the pressurized tank depressurization pipe 62, and the liquid in the processing tank 81 (not shown) is supplied. When the pressure reaches the surface sensor, the pressurized tank IPA supply valve 67 and the pressurized tank pressure release valve 63 are closed.
[0019]
Next, an inert gas (tank pressurizing N ₂ : Nitrogen gas) is supplied from the pressurized tank nitrogen gas supply pipe 64 by opening the pressurized tank nitrogen gas supply valve 65. If the IPA supply valve 55 is opened in this state, the IPA in the pressurized tank 61 reaches the spraying means 51 via the IPA supply pipe 54 by pressure feeding. When the nitrogen gas supply valve 53 is opened, an inert gas (nitrogen gas) is supplied to the spraying means 51 through the nitrogen gas supply pipe 52. Thus, the spraying means 51 can mix the IPA and the nitrogen gas inside to form a mist, and spray as an IPA mist 56.
[0020]
On the other hand, when supplying the high-temperature inert gas (nitrogen gas) to the injection means 41, as shown in FIG. 2, a heater 44 for heating the nitrogen gas to the injection means 41 and a high-temperature nitrogen gas supply valve 43 were provided. The high-temperature nitrogen gas is supplied by connecting the high-temperature nitrogen gas supply pipe 42. The high-temperature inert gas is desirably used at a temperature equal to or higher than the boiling point of the water-soluble organic solvent such as IPA by the heater 44.
[0021]
The spraying means 51 for spraying the water-soluble organic solvent mist includes, as shown in FIGS. 3 and 4, an IPA injection hole 102 for supplying and jetting a water-soluble organic solvent and an inert gas, respectively, outside the processing tank 81. A gas-liquid mixing chip 104 having a nitrogen gas injection hole 103, and the injection holes 102, 103 of the gas-liquid mixing chip 104 are covered in a dome shape and mixed in an internal space to form a mist and penetrate through the dome-shaped outer wall. And a nozzle cover 107 for opening a plurality of holes 101 to spray mist.
[0022]
Here, as shown in FIG. 3, the spraying means 51 applies nitrogen (N ₂ The gas-liquid mixing chip 104 is provided with a nitrogen gas supply pipe 106 for supplying gas, and an IPA supply pipe 105 for supplying IPA, which is provided so as to pierce from the side of the nitrogen gas supply pipe 106, to thereby provide IPA. An injection hole 102 and a nitrogen gas injection hole 103 are formed. As shown in FIG. 4, the gas-liquid mixing chip 104 has only one IPA injection hole 102 at the center and a plurality of nitrogen gas injection holes 103 formed on the outer periphery thereof. The spraying means 51 having such a structure is configured to supply the nitrogen gas supplied from the nitrogen gas supply pipe 106 and the IPA supplied from the IPA supply pipe 105 with the nitrogen gas injection holes 103 and the IPA injection of the gas-liquid mixing chip 104, respectively. The liquid is supplied to the hole 102, collides with the inside of the nozzle cover 107 to form mist, and is sprayed from the hole 101. Therefore, unlike the conventional technique shown in FIG. 16, the spraying means 51 collides the nitrogen gas and IPA once in the nozzle cover 107 to form a mist and sprays the mist from the hole 101, so that the size of the mist can be freely adjusted. An adjustable and effective drying process can be realized.
[0023]
Further, as shown in FIG. 2, a plurality of substrates 1 are stored in the cassette 2, are put into the processing tank 81 in a batch manner, and are dried. The cassette 2 is set by being directly loaded into the processing tank 81 by a predetermined transport means (not shown). Further, the processing tank 81 is provided with holding means 83 for holding the substrate 1 at a position where the substrate 1 is not exposed on the liquid surface and does not come into contact with the cassette 2 when the substrate 1 is loaded into the cassette 2. As shown in FIG. 5, the holding means 83 includes a plurality (three in FIG. 5) of holding plates 83-2 and 83-3 which extend in a rib shape at a lower portion in a direction in which the substrates 1 are independently arranged. , 83-4 are provided integrally. As shown in FIG. 6, the holding means 83 has a tooth-shaped groove 83-5 that can be held by the lower end of the substrate 1 being in contact with the holding plates 83-2 to 83-4. Are cut out so as to be V-shaped or Y-shaped (Y-shaped in FIG. 6). The holding means 83 is provided with a residual liquid suction hole 89 having a suction pump 80 for draining pure water remaining in the groove 83-5 of the holding plate shown in FIG. It is connected to the.
[0024]
When a substrate drying operation is performed using the substrate drying apparatus according to the first embodiment of the present invention formed as described above, first, the supply valve 84-2 shown in FIG. After supplying pure water to the position of the liquid level sensor (not shown) to 81, the supply valve 84-2 is closed. Next, the canopy 31 provided in the outer tank 32 is opened, and the substrate 1 is set in the processing tank 81 filled with pure water. At this time, a plurality of the substrates 1 are stored in the cassette 2 and are loaded by being directly lowered into the processing tank 81 by a transfer means (not shown). The substrate 1 stands on the comb-shaped holding means 83 without contacting the cassette 2 during the lowering of the processing tank 81, and the empty cassette 2 is moved to the deepest portion of the processing tank 81. It is set in the state of being lowered. Thereafter, the transfer means (not shown) is detached from the processing tank 81 and the outer tank 32, and the canopy 31 is closed to complete the operation preparation.
[0025]
Next, the supply valve 84-2 is opened again, and pure water is again supplied from the supply pipe 84-1 to the processing tank 81 to perform upflow rinsing. Accordingly, in the processing tank 81, after the substrate processing such as cleaning is performed by storing pure water, the substrate 1 is exposed on the liquid surface and the drying processing is performed, whereby the cleaning and the drying can be simultaneously performed. . At this time, the pure water overflowing from the upper opening of the processing tank 81 is drained from the overflow drain tank 82-1 via the overflow drain pipe. After closing the pure water supply valve 84-2 and terminating the up-flow rinsing, in a state where the pure water is filled up to the upper opening of the processing tank 81, the IPA mist 56 is simultaneously injected from the spraying means 51, or 1 Within a minute, the drain valve 86-2 is opened, the drain pump 88 is operated, and pure water is passed through the drain pipe 86-1 so that the liquid level in the processing tank 81 drops at a reduction rate of about 1 to 5 mm / sec. Drain. Thereby, the substrate 1 removes moisture from the surface by the Marangoni effect by spraying the IPA mist and the replacement (evaporation) of the attached pure water.
[0026]
At this time, the suction amount of the drain pump 88 is adjusted so as to have a temporal change so that the lowering speed is the same regardless of whether the liquid level passes through the diameter of the substrate 1 or the upper and lower ends. When the substrate 1 and the groove 83-5 of the holding means 83 are completely exposed from the pure water, the pure water remaining in the groove 83-5 of the holding means 83 is filled with the residual liquid suction hole at the bottom shown in FIG. Suction is performed from 89 using a suction pump 80. At the same time, in order to prevent the drain pump 88 shown in FIG. 2 from running idle, the drain pump 88 is stopped, the drain bypass valve 87-2 is opened, and the pure water remaining in the treatment tank 81 is drained from the drain bypass pipe 87-1. Drain.
[0027]
Further, at the same time as when the pure water is completely drained from the processing tank 81, or within two minutes, the IPA supply valve 55 and the nitrogen gas supply valve 53 are closed, the high-temperature nitrogen gas supply valve 43 is opened, and the heater 44 is set to 130 ° C. Nitrogen gas whose temperature has been adjusted back and forth is injected from the injection means 41 through the high-temperature nitrogen gas supply pipe 42 for several minutes. As a result, after the substrate 1 and the cassette 2 are completely dried, the canopy 31 is opened, the cassette 2 at the deepest part of the processing tank 81 is raised by the transport means, and the substrate 1 on the stationary holding means 83 is moved downward. From the cassette 2 and return it to the cassette 2 by scooping it up. The transporting means is further raised, the substrate 1 is taken out of the processing tank 81 together with the cassette 2, and the canopy 31 is closed to complete the drying process.
[0028]
As described above, according to the first embodiment of the substrate drying apparatus according to the present invention, as shown in FIG. 2, since the spraying means 51 is provided in the outer tank 32 so as not to protrude into the processing tank 81, The substrate 1 can be arranged without obstructing the loading and unloading of the substrate 1, and the processing tank 81 can be reduced in size.
Further, according to the first embodiment, as shown in FIG. 3, a nitrogen gas and IPA collide with each other in the space inside the nozzle cover 107 to form a mist, and the diameter of the hole 101 is adjusted to spray a desired mist. With such a structure, the size of the mist can be freely adjusted, and an effective drying step can be realized.
[0029]
Here, as for the holding means 83, as shown in FIG. 6, the embodiment in which the grooves 83-5 of the holding plates 83-2 to 4 are formed in a V-shape or a Y-shape has been described in detail, but is not limited thereto. Instead, the irregularities may be provided alternately and held. FIG. 7 is a view showing another embodiment of the holding means for providing and holding such irregularities. FIG. 8 is a top view of the holding unit 83 shown in FIG. 7 as viewed from above. FIG. 9 is a perspective view showing details of the convex portion 83-5a and the concave portion 83-5b shown in FIG. FIG. 10 is a side view of the holding unit 83 shown in FIG. 9 as viewed from the side.
[0030]
As shown in FIG. 7, in another embodiment of the holding means, like the holding means shown in FIG. 5, three holding members extending in a rib shape from the lower part in a direction in which the substrates 1 are independently arranged in a plurality. The plates 83-2, 83-3 and 83-4 are provided integrally. Here, the number of the holding plates 83-2, 83-3, and 83-4 is not limited to three, and a plurality of holding plates may be provided. The holding means 83 is different from the holding means shown in FIG. 5 in that a plurality of irregularities are alternately arranged so that the lower end of the substrate 1 is held in contact with the holding plates 83-2 to 4 extending in a rib shape. (See FIG. 9). That is, as shown in FIG. 8, the holding means 83 includes three holding plates 83 extending in a rib shape by alternately arranging a plurality of vertically projecting convex portions 83-5a and concave concave portions 83-5b. -2 to 4 are provided integrally, and one holding plate 83-3 is arranged with the arrangement of the irregularities shifted. As a result, as shown in FIG. 9, the holding means 83 is configured such that the shifted projections 83-5 a of the holding plate 83-3 hold one side of the substrate 1, and one of the holding plates 83-2, 83-not shifted. The four projections 83-5a are provided so as to hold and hold the other side surface of the substrate 1.
[0031]
At this time, the gap B shown in FIG. 9 between the projections 83-5a of the holding plates 83-2 to 83-4, that is, the recess 83-5b is formed in a groove shape having a wide width in the vertical direction. Preferably, the gap B is formed to have a width 1.5 to 3 times the thickness of the substrate 1. Further, each of the holding plates 83-2 to 83-4 is formed to have a thickness (width) C shown in FIG. 9 of 2 mm or less, and is preferably provided in a thickness of 0.5 mm to 10 mm. Thereby, in the holding plates 83-2 to 83-4, the remaining liquid amount in the gap B when the holding means 83 is exposed from pure water is small, and the drying time can be shortened. In the holding plates 83-2 to 83-4, the material of the convex portion 83-5a and the concave portion 83-5b with which the substrate 1 contacts is formed using any one of PFA, PVDF, PTFE, and PEEK. According to another embodiment of such a holding means, since the number of contact surfaces with which the convex portions 83-5a come into contact when holding the substrate 1 is smaller than in the holding means shown in FIG. The amount is small and the drying time can be shortened.
[0032]
Further, in the pure water supply / discharge section A shown in FIG. 2, the embodiment in which pure water is directly supplied to the treatment tank 81 has been described in detail, but the present invention is not limited to this. Alternatively, pure water (treatment liquid) mixed with a chemical solution can be supplied to the treatment tank. FIG. 11 is a view showing another embodiment of the supply / discharge unit for supplying such warm pure water. FIG. 12 is a view showing still another embodiment of a supply / discharge unit for supplying pure water mixed with a chemical solution. Here, in the supply / discharge unit shown in FIG. 11, all components other than the pure water heater 85-3 are the same as those in the supply / discharge unit A shown in FIG. 2, and the same components are denoted by the same reference numerals. , Overlapping description will be omitted.
[0033]
As shown in FIG. 11, another embodiment of the supply / discharge unit for supplying warm hot pure water has substantially the same configuration as the supply / discharge unit A shown in FIG. A heater 85-3 is connected to the supply valve 84-1 together with the supply valve 84-2. Here, it is desirable that the heater 85-3 is preferably heated so that the temperature of pure water immediately before exposing the substrate 1 in the processing tank 81 becomes warm pure water of 20 ° C. to 70 ° C. Specifically, for example, hot pure water whose temperature is controlled to about 60 ° C. by the heater 85-3 is supplied to the processing tank 81 from the supply pipe 85-1 by opening the supply valve 84-2, and the position of the liquid level sensor (not shown) Is reached, the supply valve 84-2 is closed to terminate the supply. Thereafter, the processing is performed by the same operation as the supply / discharge unit A shown in FIG.
[0034]
As described above, according to another embodiment of the supply / discharge unit for supplying the hot pure water, the supply / discharge unit A shown in FIG. Similar effects can be obtained. Further, when the substrate 1 is exposed from the pure water, the temperature of the substrate 1 is warmed by the hot pure water, so that an effect of promoting the evaporation of the IPA replacing the pure water adhering on the substrate 1 can be expected.
[0035]
Further, as shown in FIG. 12, in still another embodiment of a supply / discharge unit for supplying pure water mixed with a chemical solution, a supply pipe 84-1 is connected to a pure water supply via a treatment liquid mixing / stirring pipe 94-3. They are connected to a pipe 95-6 and a hydrofluoric acid supply pipe 96-6, respectively. Here, a hydrofluoric acid concentration meter 91, a chemical solution stirrer 92, and a chemical solution mixing valve 93 are connected to the treatment solution mixing and stirring pipe 94-3, and the supplied chemical solution and pure water are mixed and stirred. The treatment liquid mixing and stirring pipe 94-3 is branched via a chemical liquid mixing valve 93 into a pure water supply pipe 95-6 and a hydrofluoric acid supply pipe 96-6. A pure water flow meter 95-1, a flow control valve 95-2, and a pure water supply valve 95-5 are connected to the pure water supply pipe 95-6 to adjust the supply amount of pure water. A compressed air supply pipe 95-4 is connected to the flow control valve 95-2, and regulates the pressure of the compressed air via a precision regulator 95-3. On the other hand, the hydrofluoric acid supply pipe 96-6 is connected to a hydrofluoric acid flow meter 96-1, a flow control valve 96-2, and a hydrofluoric acid supply valve 96-5 to adjust the supply amount of the chemical solution. A compressed air supply pipe 96-4 is connected to the flow control valve 96-2, and adjusts the pressure of the compressed air via a precision regulator 96-3.
[0036]
The processing liquid mixing and stirring pipe 94-3 is connected to the supply pipe 84-1 by a three-way valve 98, and is processed into a drain pipe 86-1 for discharging the processing liquid in the processing tank 81 from the three-way valve 98. The connection is made via a liquid drain pipe 94-2. The drain pipe 86-1 has a drain bypass valve 87-2 connected via a drain-in bypass pipe 87-1 and a drain valve 86-2, similarly to the supply / discharge section A shown in FIG. Have.
[0037]
When using still another embodiment of the supply / discharge unit having such a configuration, for example, when the DHF concentration is 1: 200, the pure water flow rate is 20 L / min and the hydrofluoric acid flow rate is 0.1 L / min. The compressed air pressure of the precision regulators 95-3 and 96-3 is adjusted to adjust the supply amount to the flow control valves 95-2 and 96-2. Next, the pure water supply valve 95-5 and the hydrofluoric acid supply valve 96-5 are opened with the processing liquid flowing toward the processing liquid drain pipe 94-2 by the three-way valve 98 to supply pure water and hydrofluoric acid. Then, the mixture is mixed by a chemical mixing valve 93, and then the mixture is stirred by the flow force of a chemical stirrer 92, and the hydrofluoric acid concentration meter 91 measures the hydrofluoric acid concentration. At this time, the processing liquid flows through the processing liquid drain pipe 94-2 until the hydrofluoric acid concentration reaches the set concentration, and when the hydrofluoric acid concentration reaches the set concentration, the three-way valve 98 is switched to the supply pipe 84-1 and supplied to the processing tank 81. I do. When the position of the liquid level sensor (not shown) is reached in the processing tank 81, the three-way valve 98 is switched to the processing liquid drain pipe 94-2, and the pure water supply valve 95-5 and the hydrofluoric acid supply valve 96-5 are switched. Close and terminate supply. Next, an etching process using hydrofluoric acid is performed, and then the hydrofluoric acid is replaced with pure water by up-flow rinsing, and the processing is performed by the same operation as the supply / discharge unit A illustrated in FIG.
[0038]
As described above, according to still another embodiment of the supply / discharge unit, since pure water can be supplied to the processing tank 81 via the three-way valve 98, the same effect as the supply / discharge unit A shown in FIG. 2 can be obtained. The quality of the substrate can be further improved by mixing the pure water with a chemical solution (hydrofluoric acid) and performing the etching process.
[0039]
In the first embodiment shown in FIG. 2, a cassette containing a plurality of substrates 1 is directly loaded into a processing tank 81 storing pure water by a transfer unit (not shown). The pure water in 81 may be contaminated, and contaminants such as particles may adhere to the substrate 1. Therefore, there is a substrate drying apparatus that prevents contamination of the substrate 1 by providing a cassette elevator for loading and unloading the cassette into and from the processing tank 81. FIG. 13 is a diagram showing a schematic configuration of a substrate drying apparatus according to a second embodiment of the present invention provided with such a cassette elevator. FIG. 14 is a configuration diagram showing a detailed configuration of the substrate drying apparatus shown in FIG. Here, in the second embodiment, components other than the cassette elevator 71 shown in FIGS. 13 and 14 are the same as those in the first embodiment shown in FIG. 2, and the same components are denoted by the same reference numerals. At the same time, duplicate description will be omitted.
[0040]
As shown in FIG. 13, the second embodiment of the substrate drying apparatus according to the present invention has substantially the same configuration as the first embodiment shown in FIG. A cassette elevator 71 for placing and moving the stored cassettes up and down is installed. As shown in FIG. 14, the cassette elevator 71 has an elevating mechanism 72 near the processing tank 81 and is arranged so that the substrate 1 can be raised and lowered from pure water stored in the processing tank 81 and taken out.
[0041]
When the second embodiment of the substrate drying apparatus according to the present invention thus formed is used, first, the supply valve 84-2 is opened, and pure water (not shown) is supplied from the supply pipe 84-1 to the processing tank 81. After supplying to the position of the surface sensor, the supply valve 84-2 is closed. Next, the canopy 31 provided in the outer tank 32 is opened, and the cassette elevator 71 is raised by the elevating mechanism 72 to a position above the liquid level of the processing tank 81 filled with pure water. 2 is placed on the processing tank 81 after being lowered. In order to make the substrate 1 stand alone without coming into contact with the cassette 2 during this lowering, the substrate 1 is placed on the comb-shaped holding means 83 and only the empty cassette 2 is lowered by the cassette elevator 71 to the deepest part of the processing tank 81. To close the canopy 31. Next, the supply valve 84-2 is opened again, and pure water is again supplied from the supply pipe 84-1 to the processing tank 81 to perform upflow rinsing. At this time, the pure water overflowing from the upper opening of the processing tank 81 is drained from the overflow drain tank 82-1 via the overflow drain pipe 82-2.
[0042]
After the supply valve 84-2 is closed and the upflow rinsing is completed, in a state where the pure water is filled up to the upper opening of the processing tank 81, the IPA mist 56 is sprayed from the spraying means 51 at the same time or within one minute. The valve 86-2 is opened to operate the drain pump 88, and the pure water is drained through the drain pipe 86-1 so that the liquid level in the processing tank 81 drops at a pulling rate of about 1 to 5 mm / sec. At this time, the suction amount of the drain pump 88 is adjusted so as to have a temporal change so that the lowering speed is the same regardless of whether the liquid level passes through the diameter of the substrate 1 or the upper and lower ends. When the substrate 1 and the groove 83-5 of the holding means 83 shown in FIG. 6 are completely exposed from the pure water, the pure water remaining in the groove 83-5 of the holding means 83 is sucked by the residual liquid at the bottom of the groove. The liquid is sucked from the pipe 89 using the residual liquid suction pump 80. At the same time, the drain pump 88 shown in FIG. 14 is stopped to prevent idling, and the drain bypass valve 87-2 is opened to drain the pure water remaining in the processing tank 81 from the drain bypass pipe 87-1. At the same time or within 2 minutes when the pure water is completely drained from the processing tank 81, the IPA supply valve 55 and the nitrogen gas supply valve 53 are closed, the high-temperature nitrogen gas supply valve 43 is opened, and the heater 44 is heated to about 130 ° C. The temperature controlled nitrogen gas is injected from the injection means 41 for several minutes via the high-temperature nitrogen gas supply pipe 42.
[0043]
Then, after the substrate 1 and the cassette 2 are completely dried, the canopy 31 is opened, the cassette elevator 71 is raised, and the substrate 1 on the stationary holding means 83 is picked up by the slit of the cassette 2 so that the cassette 2 Return to Further, the cassette elevator 71 is raised to above the upper opening of the processing tank 81, and the cassette 2 on which the substrate 1 is set is taken out by a predetermined transport means.
[0044]
As described above, according to the second embodiment of the substrate drying apparatus according to the present invention, the cassette 2 containing a plurality of substrates 1 is placed in the cassette elevator 71 and immersed in the processing tank 81 instead of the predetermined transport means. The inside of the tank 81 is always kept clean without being contaminated, so that contamination of the substrate 1 can be minimized.
[0045]
Further, in the first and second embodiments shown in FIGS. 2 and 14, an embodiment has been described in which the substrate 1 is dried while the pure water in the processing tank 81 is discharged from the drain tube 86-1 when the substrate 1 is dried. However, the present invention is not limited to this. For example, there is a substrate drying apparatus that raises the substrate 1 (cassette 2) from inside the processing tank 81 and dries it. FIG. 15 is a configuration diagram showing a third embodiment of a substrate drying apparatus according to the present invention for raising and drying such a substrate 1. Except for the outer tub 32, the cassette elevator 71, the holding means 83, and the drain tube 86-1 shown in FIG. 15, all components are the same as those of the substrate drying apparatus shown in FIG. The same reference numerals are described, and duplicate description is omitted.
[0046]
As shown in FIG. 15, in the third embodiment of the substrate drying apparatus according to the present invention, the holding means 83 is provided so as to be able to move up and down above the liquid surface of the processing tank 81 together with the cassette elevator 71. Is formed so that drying treatment can be performed by raising the pressure. In the third embodiment, the outer tank 32 extends vertically in order to provide a space for the cassette elevator 71 and the holding means 83 to ascend upward, and the substrate 1 is held by the holding means 83. By raising and lowering and drying, there is no need to provide a drain pump in the drain tube 86-1 to adjust the discharge amount.
[0047]
When the third embodiment of the substrate drying apparatus according to the present invention thus formed is used, first, the substrate 1 is loaded into the processing tank 81 filled with pure water, and the substrate 1 is brought into contact with the cassette 2. In a state where the cassette 2 is held at the deepest part of the processing tank 81 (see FIG. 2), the spraying of the IPA mist from the spraying means 51 is started, and at the same time, the elevating mechanism 83-1 is used. The substrate 1 held by the holding means 83 is raised at a speed of 1 to 5 mm / sec. At this time, when the substrate 1 and the groove 83-5 of the holding means 83 (see FIG. 6) are completely exposed from the pure water, the pure water remaining in the groove 83-5 of the holding means 83 is removed from the residual liquid at the bottom of the groove. The liquid is sucked from the suction pipe 89 using the residual liquid suction pump 80. At the same time, the drain valve 86-2 is opened to drain the pure water in the processing tank 81.
[0048]
Then, the IPA supply valve 55 and the nitrogen gas supply valve 53 are closed to stop the supply of the IPA mist at the same time as when the pure water is completely drained from the processing tank 81 or within 2 minutes. Thereafter, the high-temperature nitrogen gas supply valve 43 is opened, and the nitrogen gas whose temperature is adjusted to about 130 ° C. by the heater 44 is injected from the injection means 41 through the high-temperature nitrogen gas supply pipe 42 for several minutes. Thus, after the substrate 1 and the cassette 2 are completely dried, the canopy 31 is opened, the holding means 83 is lowered by the elevating mechanism 83-1 and the substrate 1 is dropped into the slit of the cassette 2 on the stationary cassette elevator 71. After the return, the cassette 2 on which the substrate 1 is set is taken out by a predetermined transport means.
As described above, according to the third embodiment of the substrate drying apparatus of the present invention, since the holding unit 83 holds and raises the substrate 1 to perform the drying process, the pure water in the processing tank 81 is adjusted by the drain pump. It is not necessary to discharge and the operation becomes simple.
[0049]
As described above, the embodiment of the substrate drying apparatus according to the present invention has been described in detail. However, the present invention is not limited to the above-described embodiment, and can be changed without departing from the gist thereof.
For example, the embodiment using IPA as the water-soluble organic solvent has been described. However, the present invention is not limited thereto. For example, isopropanol, 2-propanol, isopropyl alcohol, ethanol, methanol, butyl alcohol, etc. may be used alone or individually. It is possible to mix and use.
Further, the embodiment using nitrogen gas as the inert gas has been described. However, the present invention is not limited to this. For example, argon, helium, etc. may be used alone or in combination.
Further, the embodiment using the treatment liquid in which pure water is mixed with hydrofluoric acid has been described (see FIG. 12). However, the present invention is not limited to this. For example, dilute hydrofluoric acid in which hydrofluoric acid water and pure water are mixed is used. APM mixed with water, hydrogen peroxide solution, ammonia water, ammonia water and hydrogen peroxide solution and pure water, hydrochloric acid solution, hydrochloric acid solution and HPM mixed with hydrogen peroxide solution and pure water, each alone or They can be used in combination.
[0050]
【The invention's effect】
As described above, according to the substrate drying apparatus of the present invention, since the spraying unit is provided in the outer tank so as not to protrude into the processing tank, the spraying unit can be arranged without obstructing the loading and unloading of the substrate. Can be reduced in size.
Further, according to the substrate drying apparatus of the present invention, after the inert gas and the water-soluble organic solvent collide with each other in the space inside the nozzle cover outside the processing tank to form mist, the water-soluble organic solvent mist is sprayed by the spraying means. Due to the structure in which the holes are adjusted and sprayed, the size of the mist can be freely adjusted, and an effective drying process can be realized.
[Brief description of the drawings]
FIG. 1 is a view showing a schematic configuration of a first embodiment of a substrate drying apparatus according to the present invention.
FIG. 2 is a configuration diagram showing a detailed configuration of the substrate drying apparatus shown in FIG. 1;
FIG. 3 is a diagram showing the internal structure of the spraying means shown in FIG.
FIG. 4 is a view showing a gas-liquid mixing chip shown in FIG. 1;
FIG. 5 is a view showing a holding unit shown in FIG. 1;
FIG. 6 is a diagram illustrating a shape of the holding plate illustrated in FIG. 5 when viewed from a side.
FIG. 7 is a view showing another embodiment of the holding means shown in FIG. 1;
8 is a top view of the holding unit shown in FIG. 7 as viewed from above.
FIG. 9 is a perspective view showing details of a convex portion and a concave portion shown in FIG. 8;
10 is a side view of the holding unit shown in FIG. 9 as viewed from the side.
FIG. 11 is a view showing another embodiment of a supply / discharge unit for supplying warm hot pure water.
FIG. 12 is a diagram showing still another embodiment of a supply / discharge unit for supplying pure water mixed with a chemical solution.
FIG. 13 is a diagram showing a schematic configuration of a second embodiment of the substrate drying apparatus according to the present invention.
FIG. 14 is a configuration diagram showing a detailed configuration of the substrate drying apparatus shown in FIG. 13;
FIG. 15 is a configuration diagram showing a third embodiment of the substrate drying apparatus according to the present invention.
FIG. 16 is a configuration diagram showing one embodiment of a conventional substrate drying apparatus.
FIG. 17 is a view showing the internal structure of the spraying means shown in FIG.
[Explanation of symbols]
1 substrate
2 cassettes
31 Canopy
32 outer tank
41 injection means
42 High-temperature nitrogen gas supply pipe
44 Pressurized heater
51 Spraying means
54 IPA supply pipe
61 Pressurized tank
64 Pressurized tank nitrogen gas supply pipe
66 Pressurized tank IPA supply pipe
81 Processing tank
82-1 Overflow drain tank
83 holding means
84-1 Supply pipe
86-1 Drain tube
88 Drain pump

Claims

A treatment tank for storing pure water and immersing the substrate,
An outer tank having an openable and closable canopy that covers the outer periphery and upper part of the processing tank and carries the substrate on the upper surface,
Injecting means for injecting a high-temperature inert gas onto a liquid surface stored in the outer tank from above the processing tank installed in the outer tank,
Installed in the vicinity of the injection means of the outer tank, by mixing a water-soluble organic solvent and an inert gas outside the processing tank and supplying it as a mist, the liquid is stored on the liquid surface stored from above the processing tank. Spraying means for spraying mist,
By draining the pure water in the processing tank or raising the substrate, the substrate is exposed on the liquid surface, and the Marangoni effect by spraying the mist and the replacement (evaporation) of the attached pure water are performed. A substrate drying apparatus, wherein the substrate is completely dried by evaporation by jetting the high-temperature inert gas.

The substrate drying apparatus according to claim 1,
In the treatment tank, when the pure water is drained to expose the substrate, a vacuum pump that constantly drains the pure water at a constant flow rate regardless of the shape of the substrate is provided. Substrate drying equipment.

The substrate drying apparatus according to claim 1,
The substrate drying apparatus, wherein the pure water is warm pure water having a temperature of 20 ° C. to 70 ° C. immediately before exposing the substrate.

The substrate drying apparatus according to claim 1,
The substrate drying apparatus according to claim 1, wherein the spraying means uses the high-temperature inert gas at a temperature equal to or higher than the boiling point of the water-soluble organic solvent.

The substrate drying apparatus according to claim 1,
The outer tank is always provided with fresh water-soluble organic solvent mist and the high-temperature inert gas from above the processing tank by covering the outer periphery and the upper part of the processing tank and opening the bottom surface. A substrate drying apparatus for discharging excess mist of the water-soluble organic solvent and the high-temperature inert gas from the bottom surface.

The substrate drying apparatus according to claim 1,
A substrate drying apparatus, wherein a plurality of the substrates are stored in a cassette, and the substrates are put into the processing tank in a batch manner to be dried.

The substrate drying apparatus according to claim 7,
The cassette is set up or removed by a predetermined transport means by raising a cassette elevator provided in the processing tank to a liquid level, and is lowered into the processing tank when the cassette is installed in the cassette elevator. A substrate drying apparatus characterized by the above-mentioned.

The substrate drying apparatus according to claim 7,
The substrate drying apparatus according to claim 1, wherein the cassette is directly loaded into the processing tank by a predetermined transfer unit.

10. The substrate drying apparatus according to claim 7, wherein the substrate is not exposed on a liquid surface and does not contact the cassette when the substrate is loaded into the processing tank by the cassette. A substrate drying apparatus, comprising: holding means for holding the substrate.

The substrate drying apparatus according to claim 10,
The holding means integrally includes a plurality of holding plates extending in a rib shape at a lower portion in a direction in which the plurality of substrates are independently arranged, and has a groove which can be held by contacting a lower end of the substrate with the holding plate. A substrate drying apparatus characterized in that the shape of the groove is V-shaped or Y-shaped.

The substrate drying apparatus according to claim 11,
The holding means is provided with a residual liquid suction hole and a suction pump capable of sucking a liquid remaining in the V-shaped or Y-shaped groove when exposed on a liquid surface in the processing tank. Substrate drying device.

The substrate drying apparatus according to claim 10,
The holding means is provided integrally with a plurality of holding plates extending in a rib shape by vertically arranging a plurality of protrusions and recesses alternately in order to make the substrate self-supporting. Are displaced from each other, and the protruding portion of the displaced holding plate holds one side of the substrate, and the protruding portion of the holding plate which is not displaced holds and holds another side of the substrate. A substrate drying apparatus characterized by being provided as described above.

The substrate drying apparatus according to claim 11, wherein
8. The substrate holding means according to claim 7, wherein said holding means has a plurality of thicknesses (widths) of said holding plate uniformly set to 0.5 mm to 10 mm.

The substrate drying apparatus according to claim 11, wherein
The substrate holding means, wherein the holding plate uses PFA, PVDF, PTFE, or PEEK as a material of a portion where the substrate contacts.

The substrate drying apparatus according to claim 1,
In the treatment tank, when supplying the pure water, a chemical mixing valve is provided in a pure water supply pipe for supplying the pure water, and at least one or more chemicals and the pure water are adjusted with a flow meter to adjust a chemical concentration. A substrate drying apparatus capable of supplying the processing liquid mixed and stirred in the pure water supply pipe.

In the substrate drying apparatus according to claim 16,
In the pure water supply pipe, a concentration meter is further provided, and the treatment liquid obtained by mixing and stirring the chemical solution and pure water is managed until the treatment concentration reaches a preset concentration, and when the concentration reaches the preset concentration, the supply into the treatment tank is started. A substrate drying apparatus, comprising:

The substrate drying apparatus according to claim 16 or 17,
The treatment liquid is diluted hydrofluoric acid water mixed with hydrofluoric acid water and pure water, hydrogen peroxide solution, ammonia water, ammonia water and hydrogen peroxide solution and APM mixed with pure water, hydrochloric acid solution, hydrochloric acid solution and A substrate drying apparatus, which is an HPM in which a hydrogen peroxide solution and pure water are mixed, and used alone or in combination.

The substrate drying apparatus according to any one of claims 1 to 18,
A substrate drying apparatus, wherein the processing tank stores only the processing liquid or the pure water and performs substrate processing such as cleaning, and then performs drying processing by exposing the substrate to a liquid level.

The substrate drying apparatus according to any one of claims 1 to 19,
The spraying means includes a gas-liquid mixing chip having an injection hole for supplying and jetting the water-soluble organic solvent and the inert gas outside the processing tank, and a dome-shaped injection hole of the gas-liquid mixing chip. And a nozzle cover for spraying the mist by opening a plurality of holes penetrating through the dome-shaped outer wall while mixing and forming a mist by mixing in an internal space.

The substrate drying apparatus according to any one of claims 1 to 20,
The water-soluble organic solvent is isopropanol, 2-propanol, isopropyl alcohol, ethanol, methanol, or butyl alcohol, and is used alone or in combination.

The substrate drying apparatus according to any one of claims 1 to 20,
The substrate drying apparatus is characterized in that the inert gas is nitrogen, argon, and helium, each of which is used alone or in combination.