JP3745140B2 - Substrate processing equipment - Google Patents

Description

【００７０】
【数２】

【００７１】
ここで、ＩＰＡ蒸気の飽和濃度Ｘ₀は、既知の物理量であり、本実施の形態では、制御プログラム３２１は、図６に示すように、温度Ｔ₀に対する飽和濃度Ｘ₀の値が予め記載されたテーブル３２２（図７参照）を予め含んでいる。今、このテーブル３２２に記載されているように（図７参照）、飽和濃度Ｘ₀は、温度Ｔ₀＝６６℃では５０％であると仮定する。なお、ここで、この飽和濃度Ｘ₀は正しい値ではなく、説明の簡素化の観点から、このような値を仮定していることを注釈しておく。この仮定に従えば、上式数２より、Ｑ_MFC1は５[l/min]となる。
【００７２】
また、蒸発槽２０１から送出される処理ガス（流量Ｑ_MFC1＋Ｑ_IPA）は、第２の配管２１２および第３の配管２１３の接続位置において、第３の配管２１３により導かれる窒素ガス（流量Ｑ_MFC2）により希釈される。故に、最終的に基板９に供給される処理ガスの総流量Ｑ_totalは数３で表されるため、Ｑ_MFC2は数４より求まる。
【００７３】
【数３】

【００７４】
【数４】

【００７５】
上述の仮定に従えば、上式数４より、Ｑ_MFC2は９０[l/min]となる。
【００７６】
ガス供給制御部１７２のＣＰＵ３０１は、上述のようにして求めた流量Ｑ_MFC1（本実施の形態では５[l/min]）を、インターフェイス部３０４を介して第１のＭＦＣ２６１に通知し、また流量Ｑ_MFC2（本実施の形態では９０[l/min]）をインターフェイス部３０４を介して第２のＭＦＣ２６２に通知する。第１および第２のＭＦＣ２６１、２６２は、通知された流量Ｑ_MFC1およびＱ_MFC2に従って、第１および第３の配管２１１、２１３内で流量Ｑ_MFC1およびＱ_MFC2が得られるように内部のコントロールバルブ２６１ａ、２６２ａを開く。
【００７７】
その後、窒素供給源８は、所定流量であって常温の窒素ガスを送出する。窒素供給源８から送出された窒素ガスは、直後に２分岐されて、第１および第３の配管２１１、２１３によって導かれる。まず、第１の配管２１１内を導かれる窒素ガスは、第１のＭＦＣ２６１によって流量Ｑ_MFC1に制御され、さらに第１のヒータ２４１により一定温度Ｔ₀になるように加熱された後に、蒸発槽２０１に導入される。蒸発槽２０１内には、前述したようにＩＰＡ蒸気が発生している。ＩＰＡ蒸気を生成している蒸発槽２０１内に窒素ガス（キャリアガス）が導入されると、処理ガスつまりＩＰＡ蒸気と窒素ガスとの混合ガスが生成される。この生成された処理ガスは、蒸発槽２０１から第２の配管２１２に送出される。一方、第３の配管２１３内を導かれる窒素ガスは、第２のＭＦＣ２６２によって流量Ｑ_MFC2に制御され、さらに第３のヒータ２４３により一定温度Ｔ₀になるように加熱された後に、第２の配管２１２に導入される。
【００７８】
よって、蒸発槽２０１から送出された処理ガスは、第３の配管２１３内を導かれてくる窒素ガスによって、第２の配管２１２と第３の配管２１３との接続位置で希釈され、その結果、希釈された処理ガスの流量は、（Ｑ_MFC1＋Ｑ_MFC2＋Ｑ_IPA）＝Ｑ_totalとなり、また、希釈された処理ガス内のＩＰＡ蒸気の濃度は、上述からも明らかなように、Ｑ_IPA／（Ｑ_MFC1＋Ｑ_MFC2＋Ｑ_IPA）＝Ｃ_IPAとなる。この希釈された処理ガスは、第２の配管２１２内を導かれていき、やがて、第４のヒータ２４４により温度Ｔ_gasに昇温された後に、外側チューブ１７１ａから基板９に供給される。その結果、基板処理装置１００内では、上述した乾燥工程が実行される。以上の説明からも明らかなように、基板９に供給される処理ガスの温度はＴ_gasであり、処理ガス内に含まれるＩＰＡ蒸気の濃度はＣ_IPAであり、処理ガスの総流量はＱ_totalである。これらはオペレータにより設定された目標パラメータそのものである。このように、基板処理装置１００では、処理ガス内のＩＰＡ蒸気の濃度は、総流量に対する第１および第３の配管２１１、２１３の流量の比率により決まり、従来のように蒸発槽内の液状ＩＰＡの温度では決まらない。このように、基板処理装置１００は、熱容量が大きい液状ＩＰＡの蒸発条件を変更することなく処理ガス内のＩＰＡ蒸気の濃度を制御できるので、迅速にオペレータの希望通りにＩＰＡ蒸気の濃度を制御することができる。
【００７９】
基板処理装置１００では、処理ガスは上述のようにして生成され、外側チューブ１７１ａから基板９に対して供給される。さらに、基板処理装置１００は処理ガスを生成している間中ずっと、基板９に供給される処理ガス内に含まれるＩＰＡ蒸気の濃度と、第１ないし第４のヒータ２４１〜２４４の加熱温度とを、以下のようにして制御している。
【００８０】
まず、ＩＰＡ蒸気の濃度制御について説明する。前述したように、第２の配管２１２上には、濃度検出センサ２５１が設けられている。この濃度検出センサ２５１は、基板９に対して供給される処理ガス内に含まれるＩＰＡ蒸気の濃度を常時測定しており、その測定結果をＣ_DETとしてガス供給制御部１７２に出力する。ガス供給制御部１７２のＣＰＵ３０１（図６参照）は、インターフェイス部３０４を介してＣ_DETを受け取る。また、ガス供給制御部１７２のＲＡＭ３０３には、オペレータにより設定された今回必要なＩＰＡ蒸気の濃度であるＣ_IPA（目標値）が保持されている。ＣＰＵ３０１は、目標値であるＣ_IPAと実際の濃度Ｃ_DETとの間の偏差に基づいて、好ましくはＰＩＤ（Proportional-plus-integral-plus-derivative）動作を実行して、第１のＭＦＣ２６１の流量を微調整する。このように、第１のＭＦＣ２６１の流量は、濃度検出センサ２５１の測定結果Ｃ_DETに基づいてフィードバック制御される。ここで、第１のＭＦＣ２６１の流量Ｑ_MFC1を微調整し、第２のＭＦＣ２６２の流量Ｑ_MFC2を微調整しない場合、基板９に供給される処理ガスの総流量Ｑ_totalは変化する。しかしながら、第１のＭＦＣ２６１の調整量は微小であるため、第２のＭＦＣ２６２の流量Ｑ_MFC2を微調整して、常時一定の総流量Ｑ_totalを得る必要性は少ない。ただし、一定の総流量Ｑ_totalを得ることができるように、第２のＭＦＣ２６２の流量Ｑ_MFC2も微調整してもよい。
【００８１】
このように、基板処理装置１００はＩＰＡ蒸気の現在の濃度を直接測定し、その測定結果に基づいて少なくとも第１のＭＦＣ２６１の流量Ｑ_MFC1を微調整するためにフィードバック制御している。これによって、オペレータの希望通りの乾燥処理を基板９に対して施すことができる。
【００８２】
次に、第１のヒータ２４１の温度制御について説明する。前述したように、第２の配管２１２上には、第１の温度センサ２２１が設けられている。この第１の温度センサ２２１は、蒸発槽２０１から送出された直後の処理ガスが有する実際の温度を常時測定しており、その測定結果をＴ_DET1として第１のＴＣ２３１に出力する。第１のＴＣ２３１には、ＣＰＵ３０１によって通知された一定温度Ｔ₀が保持されている。第１のＴＣ２３１は、一定温度Ｔ₀と実際の温度Ｔ_DET1との間の偏差に基づいて、好ましくはＰＩＤ動作を実行して、第１のヒータ２４１の加熱温度を微調整するためのフィードバック制御を実行する。このように、第１の配管２１１を導かれる窒素ガスは、蒸発槽２０１から送出される処理ガスの温度が一定温度Ｔ₀になるように加熱されるため、処理ガスの温度によって決まるＩＰＡ蒸気の濃度もまた、オペレータの希望通りに一定濃度に制御できるようになる。そのため、基板処理装置１００では、従来のような蒸発槽２０１に窒素ガスが導入されることによるＩＰＡ蒸気の濃度変化が起こりにくくなる。これによって、オペレータの希望通りの乾燥処理を基板９に対して施すことができる。
【００８３】
次に、第２のヒータ２４２の温度制御について説明する。上述した第１の温度センサ２２１は、Ｔ_DET1を第２のＴＣ２３２にも出力する。第２のＴＣ２３２にも、前述したように一定温度Ｔ₀が保持されている。第２のＴＣ２３２もまた、第１のＴＣ２３１と同様に、好ましくはＰＩＤ動作を実行して、第２のヒータ２４２の加熱温度を微調整するためのフィードバック制御を実行する。このように、蒸発槽２０１に貯留されている液状のＩＰＡは、蒸発槽２０１から送出される処理ガスの温度が一定温度Ｔ₀になるように加熱されるため、処理ガスの温度によって決まるＩＰＡ蒸気の濃度もまた、オペレータの希望通りに一定温度に制御できるようになる。これによって、オペレータの希望通りの乾燥処理を基板９に対して施すことができる。
【００８４】
次に、第３のヒータ２４３の温度制御について説明する。前述したように、第２の配管２１２には、第２の温度センサ２２２が設けられている。この第２の温度センサ２２２は、希釈された処理ガス（流量Ｑ_total）の実際の温度を常時測定しており、その測定結果をＴ_DET2として第３のＴＣ２３３に出力する。第３のＴＣ２３３にも、前述したように一定温度Ｔ₀が保持されている。第３のＴＣ２３３は、一定温度Ｔ₀と実際の温度Ｔ_DET2との間の偏差に基づいて、好ましくは上述のＰＩＤ動作を実行して、第３のヒータ２４３の加熱温度を微調整するためのフィードバック制御を実行する。このように、第３の配管２１３を導かれる窒素ガスは、希釈された処理ガスの温度が一定温度Ｔ₀になるように加熱されるため、希釈された処理ガスの温度低下を招かない。そのため、希釈された処理ガスの温度によって決まるＩＰＡ蒸気の濃度は、オペレータの希望通りに一定濃度に制御できるようになる。これによって、オペレータの希望通りの乾燥処理を基板９に対して施すことができる。
【００８５】
以上説明したように、基板処理装置１００は蒸発槽２０１内に貯留されている液状ＩＰＡの温度に基づいて処理ガス内のＩＰＡ蒸気の濃度を制御するのではなく、第２の配管２１２を導かれる処理ガス自体の濃度を測定し、この測定結果に基づいて、第１の配管２１１内を導かれる窒素ガスの流量を少なくとも微調整して処理ガス内のＩＰＡ蒸気の濃度を制御している。そのため、基板処理装置１００は基板９に対してオペレータの希望通りの乾燥処理を施すことができる。また、ＩＰＡ蒸気の濃度制御において、液状ＩＰＡの温度および第１の配管２１１を導かれる窒素ガスは、蒸発槽２０１から送出された直後の処理ガスが有する温度に基づいて一定温度Ｔ₀にフィードバック制御されている。これによって、蒸発槽２０１内の液状ＩＰＡの温度は窒素ガスが蒸発槽２０１内に導入されても変化しにくく、つまり処理ガス内のＩＰＡ蒸気はオペレータの希望通りの濃度を常に有しているため、基板処理装置１００は基板９に対してオペレータの希望通りの乾燥処理を施すことができる。
【００８６】
次に、第４のヒータ２４４の温度制御について説明する。前述したように、第２の配管２１２上には、第３の温度センサ２２３が設けられている。この第３の温度センサ２２３は、希釈された処理ガス（流量Ｑ_total）の実際の温度を常時測定しており、その測定結果をＴ_DET3として第４のＴＣ２３４に出力する。第４のＴＣ２３４には、前述したように基板９に対して供給する処理ガスの温度Ｔ_gasが保持されている。第４のＴＣ２３４は、所定温度Ｔ_gasと実際の温度Ｔ_DET4との間の偏差に基づいて、好ましくは上述のＰＩＤ動作を実行して、第４のヒータ２４４の加熱温度を微調整するためのフィードバック制御を実行する。このように、第４のヒータ２４４は、外側チューブ１７１ａの吐出口の直前において、基板９に供給される処理ガスが有する実際の温度に基づいてフィードバック制御される。そのため、処理ガスの温度は常にオペレータが希望する温度Ｔ_gasに保たれる。上述した乾燥工程においては、処理ガス内のＩＰＡ蒸気の濃度だけでなく、処理ガスの温度もまた基板９の乾燥時間に関わってくる。つまり、供給される処理ガスの温度によって、基板９自体の温度が上昇し、基板９に形成された細かな溝等に入り込んだ液滴を蒸発させることが可能となる。これによって、オペレータの期待通りの乾燥処理を基板９に対してより好適に施すことができる。
【００８７】
なお、一般に乾燥処理の開始時において基板９の温度Ｔ_Wよりも吐出される処理ガスの温度Ｔ_gasの方が温度が高いので、乾燥処理中に基板９の温度は上昇するが低下することはない。したがって、乾燥処理の開始時の基板９の温度における処理ガスのＩＰＡ蒸気の飽和濃度よりも低い濃度が設定されると、乾燥処理の途上においても常にＩＰＡ蒸気の濃度は飽和濃度を下回るように保たれる。
【００８８】
次に、一連の基板処理工程が終了し、新たな基板処理工程に移行する場合において、基板処理装置１００は処理ガスの総流量を一定に保ちつつ、処理ガス内のＩＰＡ蒸気の濃度を変更するためには、以下の動作を実行する。まず最初に、オペレータは、前述したレシピに従って、新しい３個の目標パラメータＱ_total、Ｔ_gasおよびＣ_IPAを設定する。次に、基板処理装置１００はスタンバイ工程を実行し、洗浄工程後の乾燥工程に移行する。乾燥工程に移行した時点では、基板処理装置１００のＲＡＭ３０３（作業領域）には、総流量Ｑ_total、温度Ｔ_gasおよび濃度Ｃ_IPAが格納されている。前述したように、基板処理装置１００は、まず最初に流量Ｑ_MFC1および流量Ｑ_MFC2を初期設定する。そのため、ＣＰＵ３０１は、総流量Ｑ_totalと濃度Ｃ_IPAとをかけ算して流量Ｑ_IPAを求める。例えば、オペレータが、今回、レシピに従って、Ｑ_totalを１００[l/min]と、また基板９の測定温度におけるＩＰＡ飽和濃度が１０％を超えるものであると仮定し、濃度Ｃ_IPAを１０％と設定したとすると、流量Ｑ_IPAは１０[l/min]となる。
【００８９】
蒸発槽２０１内の液状ＩＰＡは、一定温度Ｔ₀（飽和濃度Ｘ₀％）になるように加熱されている。この時、Ｑ_MFC1は、数２より１０[l/min]となる。また、Ｑ_MFC2は、数４より８０[l/min]となる。基板処理装置１００の第１のＭＦＣ２６１および第２のＭＦＣ２６２は、上述のようにして求めた流量Ｑ_MFC1（本実施の形態では１０[l/min]）および流量Ｑ_MFC2（本実施の形態では８０[l/min]）が得られるように内部のコントロールバルブ２６１ａ、２６２ａを開く。
【００９０】
このように、基板処理装置１００は、蒸発槽２０１内に導入する窒素ガスの流量および第３の配管２１３を導かれる窒素ガスの流量を変更することにより、処理ガスの総流量を一定に保ちつつ、処理ガス内のＩＰＡ蒸気の濃度を変更することができる。このように、基板処理装置１００では熱容量の大きな液状ＩＰＡ（蒸発槽２０１内に貯留）の温度を変更する必要がない。そのため、基板処理装置１００によれば次の基板処理工程に短時間で容易に移行できる。
【００９１】
また同様に、前回の基板処理工程から新たな基板処理工程に移行する場合において、基板処理装置１００は処理ガス内のＩＰＡ蒸気の濃度を一定に保ちつつ処理ガスの総流量を変更するためには、以下の動作を実行する。まず最初に、オペレータは前述したレシピに従って、新しい３個の目標パラメータＱ_total、Ｔ_gasおよびＣ_IPAを設定する。次に、基板処理装置１００はスタンバイ工程を実行し、洗浄工程後の乾燥工程に移行する。この移行時、基板処理装置１００のＲＡＭ３０３（作業領域）には、総流量Ｑ_total、温度Ｔ_gasおよび濃度Ｃ_IPAが格納されている。前述したように、基板処理装置１００は、まず最初に、流量Ｑ_MFC1および流量Ｑ_MFC2を初期設定する。そのため、ＣＰＵ３０１は、総流量Ｑ_totalと濃度Ｃ_IPAとをかけ算して流量Ｑ_IPAを求める。例えば、オペレータが、今回、レシピに従ってＱ_totalを２００[l/min]と設定し、濃度Ｃ_IPAを１０％と設定したと仮定する。この仮定に従えば、流量Ｑ_IPAは２０[l/min]となる。
【００９２】
蒸発槽２０１内の液状ＩＰＡは、一定温度Ｔ₀（飽和濃度Ｘ₀）になるように加熱されている。この時、Ｑ_MFC1は、数２より２０[l/min]となる。また、Ｑ_MFC2は、数４より１６０[l/min]となる。基板処理装置１００の第１のＭＦＣ２６１および第２のＭＦＣ２６２は、上述のようにして求めた流量Ｑ_MFC1（本実施の形態では２０[l/min]）および流量Ｑ_MFC2（本実施の形態では１６０[l/min]）が得られるように内部のコントロールバルブ２６１ａ、２６２ａを開く。
【００９３】
このように、基板処理装置１００は、蒸発槽２０１内に導入する窒素ガスの流量および第３の配管２１３を導かれる窒素ガスの流量を変更することにより、処理ガス内のＩＰＡ蒸気の濃度を一定に保ちつつ処理ガスの総流量を変更することができる。
【００９４】
このように、基板処理装置１００では熱容量の大きな液状ＩＰＡ（蒸発槽２０１内に貯留）の温度を変更する必要がない。そのため、基板処理装置１００によれば、次の基板処理工程に短時間で容易に移行できる。
【００９５】
なお、上述した基板処理装置１００では、第１の温度センサ２２１がその検出結果Ｔ_DET1を第１および第２のＴＣ２３１、２３２に出力するようにし、第１および第２のＴＣ２３１、２３２はＴ_DET1に基づいて、第１および第２のヒータ２４１、２４２の加熱温度をフィードバック制御していた。しかしながら、基板処理装置１００は第１および第２のヒータ２４１、２４２の加熱温度をフィードバック制御するために、第１の温度センサ２２１に代えて濃度検出センサを用いてもよい。この濃度検出センサは、蒸発槽２０１から送出された処理ガス内に含まれるＩＰＡの実際の濃度を測定する。前述したように、蒸発槽２０１から送出された直後の処理ガスは飽和蒸気であるため、ＩＰＡ蒸気の濃度を測定できれば、処理ガスの温度は一義的に求められる。したがって、第１および第２のＴＣ２３１、２３２は、この濃度検出センサの測定結果に基づいて、第１および第２のヒータ２４１、２４２の加熱温度をフィードバック制御することもできる。
【００９６】
また、上述した基板処理装置１００は、濃度検出センサ２５１がその測定結果Ｃ_DETをガス供給制御部１７２に出力するようにし、ガス供給制御部１７２はＣ_DETに基づいて、少なくとも第１のＭＦＣ２６１の流量をフィードバック制御するようにしていた。しかしながら、ガス供給制御部１７２は少なくとも第１のＭＦＣ２６１の流量をフィードバック制御するために、濃度検出センサ２５１の検出結果Ｃ_DETではなく、第１の温度センサ２２１または第２の温度センサ２２２の測定結果Ｔ_DET1またはＴ_DET2を用いてもよい。上述したように、第１の温度センサ２２１および第２の温度センサ２２２は、一定温度（上述の実施の形態ではＴ₀）に制御された処理ガスの温度を測定する。上述からも明らかな通り、一定温度（Ｔ₀）を測定できれば、第２の配管２１２を導かれる処理ガス内に含まれるＩＰＡの濃度は一義的に求められる。したがって、ガス供給制御部１７２は、この第１の温度センサ２２１または第２の温度センサ２２２の測定結果に基づいて、少なくとも第１のＭＦＣ２６１の流量Ｑ_MFC1をフィードバック制御することもできる。
【００９７】
また、上述した基板処理装置１００は、第３の温度センサ２２３がその測定結果Ｔ_DET3を第４のＴＣ２３４に出力するようにし、第４のＴＣ２３４はＴ_DET3に基づいて、第４のヒータ２４４の加熱温度をフィードバック制御していた。しかしながら、基板処理装置１００はこのようなフィードバック制御のために、第３の温度センサ２２３の測定結果Ｔ_DET3に代えて、第２の温度センサ２２２の測定結果Ｔ_DET2を用いてもよい。このように測定結果Ｔ_DET2を用いることができるのは、第２の温度センサ２２２および第３の温度センサ２２３は両方とも、第２の配管２１２内を導かれかつ希釈された処理ガスの温度を求めているからである。
【００９８】
なお、上述の実施の形態では、ＩＰＡ蒸気に関して具体的に説明した。しかしながら、半導体デバイス等の各製造工程では、ＩＰＡ蒸気だけでなく有機溶剤蒸気や水蒸気等もまた処理蒸気として用いられる。これら処理蒸気もまたキャリアガスと混合された上で用いられる場合が多く、処理蒸気の濃度もまた正確に制御される必要がある。基板処理装置１００はこれらの処理蒸気に関しても適用することができる。
【００９９】
以上説明してきたように、このガス供給部１７１では窒素供給源８から外側チューブ１７１ａの吐出口へと流れるガスの様々な物理的要素を測定し、この測定値を処理ガスにおけるＩＰＡ蒸気の濃度を制御するための濃度制御パラメータとして利用することができる。また、ＩＰＡ蒸気の濃度の制御を行うに際しても様々な箇所を流れるガスの物理的要素を制御対象として採用することができる。
【０１００】
既述のように、第２の配管２１２のうち第３の配管２１３との接続位置から吐出口へと流れるガス中のＩＰＡ蒸気の濃度の測定値は直接的に濃度制御パラメータとして利用することができる。
【０１０１】
また、第１および第３の配管２１１、２１３を流れるガスの流量が既知の場合には、既述のように第２の配管２１２のうち蒸発槽２０１と第３の配管２１３との接続位置との間におけるガス中のＩＰＡ蒸気の濃度の測定値からも処理ガス中のＩＰＡ蒸気の濃度を求めることができるので、濃度制御パラメータとして利用することができる。
【０１０２】
さらに、蒸発槽２０１中の液状ＩＰＡの温度、第１の配管２１１を流れるガスの温度、蒸発槽２０１から第２の配管２１２へと導かれた直後のガスの温度も、蒸発槽２０１から流出するガス中のＩＰＡ蒸気の濃度に密接に関係することから、濃度制御パラメータとして利用することができる。
【０１０３】
このように、処理ガスに関する様々な物理的要素のうちの少なくとも１つを濃度制御パラメータとして取得し、取得された濃度制御パラメータに基づいて処理ガス中のＩＰＡ蒸気の濃度を制御することができる。
【０１０４】
一方、処理ガス中のＩＰＡ蒸気の濃度を制御するための制御対象としては、第１の配管２１１内のガスの流量または第３の配管２１３内のガスの流量を調整することにより、これらの配管内の流量の比を制御することで濃度調整が可能である。
【０１０５】
また、上記説明では、第１の配管２１１中のガスの温度、蒸発槽２０１中の液状ＩＰＡの温度等が同じ温度Ｔ₀に制御されると説明したが、これらの温度は個別に設定されてもよい。このとき、蒸発槽２０１中から流れ出すガス中のＩＰＡ蒸気は飽和状態でない場合も考えられ、上記説明のような簡単な計算により流量等を求めることはできないが、フィードバック制御を適宜行うことにより処理ガス中のＩＰＡ蒸気の濃度を適切に維持することができる。
【０１０６】
また、第１の配管２１１中のガスの温度や蒸発槽２０１中の液状ＩＰＡの温度を変化させる場合において、これらの温度を変化させると蒸発槽２０１から流れ出るガス中のＩＰＡ蒸気の濃度が変化し、これにより、処理ガス中のＩＰＡ蒸気の濃度を変化させることができるので、第１の配管２１１中のガスの温度や蒸発槽２０１中の液状ＩＰＡの温度も制御対象として利用することができる。
【０１０７】
このように、様々な要素のうちの少なくとも１つを制御対象として制御することにより処理ガス中のＩＰＡ蒸気の濃度を制御することができる。
【０１０８】
また、上記実施の形態では、ＩＰＡ蒸気の濃度がオペレータにより設定されると説明したが、ＩＰＡ蒸気の濃度設定は自動で行うこともできる。すなわち、温度計１５４により測定された基板９の温度（または、基板９の温度に相当する温度）Ｔ_WにおけるＩＰＡの飽和濃度をテーブル３２２を参照しながらガス供給制御部１７２が求め、求められた飽和濃度を下回る濃度がＣ_DETとして自動的に決定されてもよい。
【０１０９】
また、乾燥処理中の基板９の温度Ｔ_Wの変化に応じて、Ｃ_DETが自動的に変更されてもよい。この基板処理装置１００では濃度Ｃ_DETをフィードバック制御により制御しているので、処理中に基板９の温度Ｔ_Wが上昇した場合に、これに合わせて濃度Ｃ_DETを変更することも可能である。
【０１１０】
このように、基板処理装置１００では自動的に基板９の表面におけるＩＰＡの結露を防止する濃度制御を行うこともできる。
【０１１１】
以上、この発明に係る第１の実施の形態である基板処理装置１００について説明してきたが、この基板処理装置１００では高速回転にて基板９に付着している純水を飛散させた後に基板９の回転速度を低速回転に減少させ（あるいは停止させ）、かつ、少なくとも低速回転時に処理ガスを基板９に供給するようにしているので、ウォーターマークの発生を防止しつつ処理ガスの供給量を低速回転時（あるいは停止時）に必要な量のみに制限することができる。これにより、基板９の製造コストを抑えつつ良好な品質の基板９の製造が可能となる。
【０１１２】
また、処理ガス中のＩＰＡ蒸気の濃度を適切に制御することができるので、基板９の表面においてＩＰＡ蒸気が結露することを防止することができ、適切な乾燥処理を行うことができる。
【０１１３】
＜２． 第２の実施の形態＞
図８はこの発明の第２の実施の形態である基板処理装置１００ａの機械的構成を示す縦断面図である。なお、制御系の構成は図２に示す構成とほぼ同様であり、ガス供給部１７１およびガス供給制御部１７２の構成もそれぞれ図５および図６に示す構成とほぼ同様である。
【０１１４】
基板処理装置１００ａは第１の実施の形態である基板処理装置１００と比較して、基板９の下面（裏面）に対しても純水やガスを供給することができるようにされている点、雰囲気遮断板１５１を回転することができるようにされている点、および温度計１５４がカップ１０４内の温度を測定するという点を除いて第１の実施の形態と同様である。以下の説明ではこれらの相違点について簡単に説明するものとし、第１の実施の形態と同様の構成については同様の符号を用いて説明する。
【０１１５】
基板処理装置１００ａでは、基板９の下面に対しても純水や処理ガスを供給することができるように、第１の実施の形態の雰囲気遮断板１５１における構造と同様に、保持台１２１のおよそ中央に２重構造チューブの端部が露出するようにされている。そして、この２重構造チューブの内側チューブ１６１ａは純水供給部１６１に接続され、外側チューブ１７１ａはガス供給部１７１に接続される。
【０１１６】
また、２重構造チューブを保持台１２１から露出させるために、モータ１３１として中空のモータを利用し、モータ１３１を支持する支持台１３３、モータ１３１、回転軸１２３および保持台１２１を順に貫通するように２重構造チューブが配置される。なお、２重構造チューブは回転軸１２３内部にて軸受１２３１により支持され、外側チューブ１７１ａは軸受１２３１に容易に支持されるように多少硬質の材料にて形成されている。また、２重構造チューブと保持台１２１や回転軸１２３との間の隙間にラビリンス１２３２を形成して軸受１２３１を進入物から保護している。ラビリンス１２３２はＶシールやパッキン等であってももちろんよい。
【０１１７】
この基板処理装置１００ａでは雰囲気遮断板１５１も基板９の回転に合わせて同方向に回転することができるようにされている。したがって、基板９の下面側と上面側の構成とは同様のものとなっている。すなわち、雰囲気遮断板１５１は回転軸１５３において中空のモータ１３１ａを介して支持軸１５２に接続されており、２重構造チューブが支持軸１５２、モータ１３１ａ、回転軸１５３および雰囲気遮断板１５１を貫通するようにして配置されている。また、２重構造チューブは回転軸１５３内部の軸受１５１１により支持されており、雰囲気遮断板１５１や回転軸１５３と２重構造チューブとの間の隙間にはラビリンス１５１２が設けられている。そして、内側チューブ１６１ａは純水供給部１６１に接続されており、外側チューブ１７１ａはガス供給部１７１に接続されている。
【０１１８】
なお、図８では雰囲気遮断板１５１側と保持台１２１側とにおいて別個に純水供給部１６１およびガス供給部１７１を示しているが、雰囲気遮断板１５１側の２重構造チューブと保持台１２１側の２重構造チューブとが同一の純水供給部１６１やガス供給部１７１に接続されていてもよい。
【０１１９】
基板処理装置１００ａの制御系は、図２に示す第１の実施の形態における制御系とほぼ同様となっている。すなわち、モータ制御部１３２が保持台１２１側のモータ１３１および雰囲気遮断板１５１側のモータ１３１ａを制御するようになっており、純水供給制御部１６２およびガス供給制御部１７２が保持台１２１側および雰囲気遮断板１５１側の純水供給部１６１やガス供給部１７１を制御するようになっている。また、回転台１２１下方には温度計１５４が配置されており、カップ１０４内の雰囲気の温度を測定する。温度計１５４で測定された温度は基板９の温度とみなされて第１の実施の形態と同様にガス供給制御部１７２において利用される。
【０１２０】
次に、基板処理装置１００ａの動作について図９を用いて説明する。なお、基板処理装置１００ａの動作は第１に実施の形態と同様、図３や図４に示した動作であってもよく、以下に説明する動作は一例にすぎない。また、図９に示す回転動作は保持台１２１および雰囲気遮断板１５１に共通のものであり、処理ガス供給動作および純水供給動作についても基板９の上下両面に対して共通のものである。さらに、図９中に示す符号も図３や図４と同様のものを用いている。
【０１２１】
図９に示すように、符号Ｐ１にて示す洗浄工程では、基板９の上面および下面に純水を供給しながら基板９を回転させて基板９の上下両面に洗浄処理が施される。洗浄処理が完了すると（時刻ＴＭ１）、純水供給動作を停止するとともに基板９を１５００〜３０００rpmで２〜３秒回転させる。これにより、基板９の上面および下面に付着している純水がカップ１０４へと飛散し、基板９に付着している純水の大部分が取り除かれる。このとき、基板９の上面および下面への処理ガスの供給は、図９中太実線にて示すように停止していてもよく、太破線にて示すように５００リットル／分程度で行われていてもよい。なお、時刻ＴＭ１〜ＴＭ２までの工程は図３や図４に示した工程とほぼ同様である。
【０１２２】
次に、基板９の高速回転による純水の大部分の取り除きが完了すると（時刻ＴＭ２）、基板９の回転を５００rpm程度に減少させ、その後２０〜３０秒を費やして基板９の回転速度を徐々に連続的に減少させる（時刻ＴＭ２〜ＴＭ３）。また、基板９の回転速度の減少に合わせて基板９の上面および下面に供給される処理ガスの供給量も５００リットル／分から１００リットル／分程度まで徐々に減少させる。
【０１２３】
既述のように、基板９が回転している場合には雰囲気遮断板１５１とカップ１０４との隙間Ｇからの大気の流入を防止するために処理ガスを基板９に供給する必要がある。この供給量はおおよそ基板９の回転速度に比例した量が必要となる。そこで、この動作例では基板９の回転速度の減少にともなって処理ガスの供給量も減少させるようにしている。
【０１２４】
そして、２０〜３０秒の処理ガスの供給が完了すると（時刻ＴＭ３）、符号Ｐ２にて示す乾燥工程が完了する。
【０１２５】
なお、本実施の形態において用いられる処理ガスのＩＰＡ蒸気の濃度も第１の実施の形態と同様にフィードバック制御されており、処理ガスの流量が連続的に変化してもＩＰＡ蒸気の濃度は所定の濃度Ｃ_DETに調整される。これにより、基板９の表面でのＩＰＡの結露が防止される。
【０１２６】
以上、第２の実施の形態である基板処理装置１００ａの構成および動作について説明してきたが、この基板処理装置１００ａでは基板９の上面のみならず下面にも純水および処理ガスを供給することができるので、基板９の下面の状態を清浄に維持することができる。特に、近年の高密度化された半導体装置の製造においては基板９の下面の状態も清浄に維持するように求められており、この基板処理装置１００ａはこのような要求に応える構成となっている。
【０１２７】
また、基板処理装置１００ａでは雰囲気遮断板１５１も基板９の回転に合わせて回転させるので、基板９の上面における気流の乱れを抑えることができ、隙間Ｇからの大気の流入をより効果的に抑えることができる。
【０１２８】
また、図９に示すように基板９の回転速度に応じて処理ガスの供給量を調整するので、基板９の回転に対して過不足のない処理ガスの供給が実現されるようになっている。
【０１２９】
＜３． 変形例＞
以上、この発明に係る基板処理装置について説明してきたが、この発明は上記実施の形態に限定されるものではなく様々な変形が可能である。
【０１３０】
例えば、保持台１２１はピン１２２により基板９を保持するようになっているが、基板９を保持台１２１上に固定できるのであればどのような形態であってもよく、吸着チャックにより基板９が固定されるようになっていてもよい。また、保持される基板９の姿勢も水平姿勢に限定されるものではない。
【０１３１】
また、モータ１３１、１３１ａは電気的なモータに限定されるのではなく、保持台１２１を回転させる動力を生じるのであればどのような形態であってもよい。
【０１３２】
また、ガス供給部１７１からの処理ガスは雰囲気遮断板１５１や保持台１２１から供給されるようになっているが、基板９の上面や下面に処理ガスを供給することができるのであればどのような形態であってもよい。例えば、基板９の上方に細い管を渡して基板９の上面にガスを噴出するようにしてもよいし、保持台１２１に開口を形成してこの開口を介して基板９の下面にガスを供給するようにしてもよい。
【０１３３】
さらに、上記実施の形態では窒素ガスにＩＰＡ蒸気を混合した処理ガスを用いているが、窒素ガス単独であってもく、他の有機溶剤の蒸気を含むガスでもよく、あるいは、窒素ガスとは別のガスを使用してもよく、乾燥に適したものであればどのようなものでもよい。
【０１３４】
また、上記実施の形態では、温度に対する有機溶剤の蒸気の飽和濃度をテーブル３２２を参照して求めると説明したが、テーブル３２２には温度に対する飽和蒸気圧が記憶されていてもよい。例えば、有機溶剤としてＩＰＡを使用し、基板９の温度が２０℃の場合、ＩＰＡの飽和濃度は、２０℃における飽和蒸気圧が３２．４mmＨgであるから、３２．４mmＨg÷７６０mmＨg＝４．２６％、と算出される。これにより、オペレータは例えば、４．２６％未満の濃度である３％をＣ_DETとして入力することで基板表面でのＩＰＡ蒸気の結露が防止される。
【０１３５】
また、純水の供給についても上記実施の形態に限定されるものではなく、ガスの供給の場合と同様に様々な変形が可能であり、２重構造チューブを利用せずにガスとは個別に基板９に純水が供給されるようになっていてもよい。さらに、純水による洗浄処理は基板処理装置において行われるのではなく、洗浄後の基板９が基板処理装置に搬入されるようになっていてもよい。
【０１３６】
また、上記実施の形態では純水洗浄後の基板９の乾燥処理について説明したが、純水に限定されず、純水以外の洗浄液による洗浄後の乾燥処理であってもよい。さらに、洗浄後の乾燥処理に限定されるものでもなく、他の処理後の乾燥処理であってもよい。
【０１３７】
また、乾燥工程における基板９の回転速度は上記実施の形態ではおおよそ高速回転から低速回転へと減少させるようにしているが、処理内容によっては徐々に減少させるようにしてもよい。例えば、図９において、時刻ＴＭ１から時刻ＴＭ３に向けて回転速度を連続的に減少させてもよい。また、実施の形態において示した回転速度やガス供給量は一例であってこのような値に限定されるものではない。
【０１３８】
さらに、上記実施の形態では半導体基板に対して乾燥を行う様子について説明したが、半導体基板の乾燥に限定されるものではなく、例えば、液晶表示器製造用もしくはフォトマスク製造用のガラス基板の処理工程における乾燥処理を行う装置であってもよい。
【０１３９】
また、上記実施の形態では、温度計１５４を用いて雰囲気遮断板１５１の温度またはカップ１０４内の雰囲気の温度を測定し、測定された温度が基板９の温度であるとみなしているが、雰囲気遮断板１５１や保持台１２１に開口を設けて、この開口から基板９の温度を放射温度計を用いて測定してもよい。さらには、洗浄処理に用いられる純水の温度や基板処理装置近傍の大気の温度を乾燥処理前の基板９の温度に相当する温度として利用してもよい。すなわち、基板９の温度測定は直接的であっても間接的であってもよい。
【０１４０】
また、上記実施の形態では、乾燥処理の最初の段階において基板９の温度が常温であるものとして説明したが、スタンバイ工程において吐出されるガスを用いて基板９の温度を常温以上に温めておくようにしてもよい。
【０１４１】
さらには、上記実施の形態では基板９の温度（正確には、基板９の温度に相当する温度）を測定するようにしているが、基板９の温度が一定の温度以下であることが保証されている場合には、この温度における飽和蒸気圧以下の蒸気圧にてＩＰＡ蒸気を処理ガスに含ませることで、基板９の表面におけるＩＰＡ蒸気の結露を防止することができる。
【０１４２】
【発明の効果】
請求項１ないし９記載の発明では、保持台を回転させて基板に付着した液を飛散させた後に保持台の回転速度を減少させるとともに基板へのガスの供給を行うので、基板の回転による大気の巻き込みを防止するために供給されるガスの量を抑えることができる。これにより、ガスの消費を抑えつつウォーターマークの発生を防止することができる。
【０１４３】
また、請求項３記載の発明では基板に付着した液を飛散させた後に保持台の回転速度を第１の回転速度から第２の回転速度へと減少させ、請求項４記載の発明では基板に付着した液を飛散させた後に保持台の回転を停止させるので、基板に供給すべきガスの量が保持台の回転速度に応じた量で足りることとなる。
【０１４４】
また、請求項６記載の発明では有機溶剤蒸気の結露を防止しつつ基板の乾燥を迅速に行うことができる。
【０１４５】
また、請求項７記載の発明では基板と雰囲気遮断板との間に発生する気流の乱れを防止して大気の巻き込みをさらに抑えることができ、請求項７記載の発明では基板の他の主面に対しても乾燥処理を施すことができる。
【０１４６】
さらに、請求項９記載の発明では、供給されるガスの流量を保持台の回転速度に応じて変更することができるので、さらに過不足のないガスの供給を実現することができる。
【図面の簡単な説明】
【図１】この発明の第１の実施の形態である基板処理装置の縦断面図である。
【図２】図１に示す基板処理装置の制御系を示すブロック図である。
【図３】基板処理装置の動作の一例を示すタイムチャートである。
【図４】基板処理装置の動作の他の例を示すタイムチャートである。
【図５】ガス供給部の構成等を示すブロック図である。
【図６】ガス供給制御部の構成等を示すブロック図である。
【図７】ＩＰＡ蒸気の飽和濃度と温度との関係を示すテーブルである。
【図８】この発明の第２の実施の形態である基板処理装置の縦断面図である。
【図９】基板処理装置の動作のさらに他の例を示すタイムチャートである。
【図１０】従来の基板処理装置の縦断面図である。
【図１１】ウォーターマークの発生原理を示す図である。
【符号の説明】
９ 基板
１００、１００ａ 基板処理装置
１２１ 保持台
１３１、１３１ａ モータ
１３２ モータ制御部
１５１ 雰囲気遮断板
１７１ ガス供給部
１７１ａ 外側チューブ
１７２ ガス供給制御部
２４１〜２４４ ヒータ[0001]
BACKGROUND OF THE INVENTION
The present invention processes a substrate for fine pattern formation (hereinafter referred to as “substrate”) such as a semiconductor substrate for manufacturing a semiconductor device, a glass substrate for a liquid crystal display, and a glass substrate for a photomask (for example, after cleaning the substrate). The substrate processing apparatus performs a drying process.
[0002]
[Prior art]
Conventionally, as a method for drying a substrate washed with pure water, there is a method of removing pure water adhering to the substrate by rotating the substrate. FIG. 10 is a longitudinal sectional view showing the configuration of a substrate processing apparatus 900 that employs such a drying method.
[0003]
In the substrate processing apparatus 900, the substrate 9 to be dried is held on the holding table 901 in a horizontal posture by a pin (a posture in which the normal line of the main surface of the substrate 9 faces the vertical direction). The holding table 901 is indicated by an arrow 901R. As shown in the figure, it rotates around an axis that faces in the vertical direction. When the holding base 901 rotates, the substrate 9 rotates in a horizontal posture, and pure water adhering to the substrate 9 scatters around the substrate 9. Thereby, pure water is removed from the substrate 9 and the substrate 9 is dried. The splashed droplets are received and collected by a cup 902 provided around the side of the substrate 9.
[0004]
In such a substrate processing apparatus, an atmosphere blocking plate 903 is provided at a position facing the upper main surface of the substrate 9. A gas supply pipe 904 is connected to the atmosphere shielding plate 903, and a processing gas (nitrogen gas (N) is provided from the atmosphere shielding plate 903 toward the upper surface of the substrate 9 as indicated by an arrow 904 F.₂Or a mixed gas of nitrogen gas and IPA (isopropyl alcohol) vapor, etc.). With such a configuration, the atmosphere inside the cup 902 on which the substrate 9 is disposed is isolated from the atmosphere outside the cup 902, and the atmosphere on the upper surface side of the substrate 9 is maintained in the atmosphere of the processing gas.
[0005]
The reason why the atmosphere on the upper surface side of the substrate 9 is maintained in the atmosphere of the processing gas is to prevent a watermark from being generated on the surface of the substrate 9. The watermark means that when the droplets adhering to the substrate 9 are dried, the substrate 9 and oxygen in the atmosphere (O₂) And react. For example, in the case of a silicon (Si) substrate, as shown in FIG. 11, silicon dioxide (SiO 2) generated by the action of oxygen in the atmosphere at the boundary between a pure water droplet and a silicon substrate.₂) Is a watermark.
[0006]
When the watermark is generated, the quality of the fine pattern formed on the substrate 9 is deteriorated or particles are generated. Therefore, conventionally, the atmosphere on the substrate 9 is maintained in an oxygen-free atmosphere by the configuration shown in FIG.
[0007]
In addition, the watermark in the following description is not limited to the pattern which arises from a pure water, It uses as a term also including the pattern produced in the case of drying of another kind of liquid.
[0008]
[Problems to be solved by the invention]
By the way, conventionally, when the substrate 9 is dried, the substrate 9 is rotated at a high speed of about 1500 to 3000 rpm. When the substrate 9 is rotated at such a high speed, the airflow is greatly disturbed around the substrate 9, and even if the processing gas is supplied to the substrate 9, the air outside the cup 902 is released from the gap between the cup 902 and the atmosphere blocking plate 903. As shown by the arrow 908F in FIG. 10, it is caught in the cup 902. As a result, the air enters the upper surface of the substrate 9, oxygen is mixed into the processing gas atmosphere around the substrate 9, and a watermark is likely to be generated on the substrate 9.
[0009]
Of course, there is no way to solve this problem by increasing the flow rate of the processing gas supplied to the substrate 9 (for example, increasing the flow rate of several hundred liters / minute to several thousand liters / minute). Consumption of a large amount of high purity nitrogen gas or the like is difficult in terms of cost. In recent years, the necessity of cleaning the back surface of the substrate 9 (the lower surface in FIG. 10) has been recognized. In this case, it is necessary to supply a processing gas to both the upper and lower surfaces of the substrate 9 during drying. Since a large amount of processing gas is required, the realization thereof becomes impossible.
[0010]
Accordingly, an object of the present invention is to provide a substrate processing apparatus capable of preventing the generation of a watermark while suppressing the consumption of a processing gas that maintains the atmosphere around the substrate.
[0011]
[Means for Solving the Problems]
  The invention of claim 1 is a substrate processing apparatus for removing a liquid adhering to a substrate, a holding table for holding the substrate, a rotation driving source for rotating the substrate held by rotating the holding table, An atmosphere blocking plate arranged to face one main surface of the substrate held by the holding table, a gas supply means for supplying gas toward the one main surface, and a substrate by rotating the holding table A rotation control means for controlling the rotation drive source so that the rotation speed of the holding table decreases after the liquid adhering to the substrate is scattered, and at least after rotating the holding table to disperse the liquid adhering to the substrate And a gas supply control means for controlling the gas supply means so as to supply the gas to the substrate.While the rotation control means continues to rotate the holding table at a reduced rotation speed, the gas supply control means rotates the holding table while the rotation control means rotates the holding table to scatter the liquid adhering to the substrate. The gas is supplied at the same flow rate as the gas supplied to.
  The invention of claim 2 is a substrate processing apparatus for removing the liquid adhering to the substrate, a holding table for holding the substrate, a rotation driving source for rotating the substrate held by rotating the holding table, An atmosphere blocking plate arranged to face one main surface of the substrate held by the holding table, a gas supply means for supplying gas toward the one main surface, and a substrate by rotating the holding table Rotation control means for controlling the rotational drive source so that the rotation speed of the holding table decreases after the liquid adhering to the substrate is scattered, and at least the step of rotating the holding table to splash the liquid adhering to the substrate. Gas supply control means for controlling the gas supply means so as to stop supply of gas during the interval and thereafter start supplying the gas to the substrate.
[0012]
  Claim3The invention of claim 1Or 22. The substrate processing apparatus according to claim 1, wherein the rotation control unit changes the rotation speed of the holding table from a first rotation speed at which the liquid adhering to the substrate is scattered to a relatively low second rotation speed. .
[0013]
  Claim4The invention of claim 1Or 24. The substrate processing apparatus according to claim 1, wherein the rotation control means continuously decreases the rotation speed of the holding table.
[0014]
  Claim5The present invention is a substrate processing apparatus for removing a liquid adhering to a substrate, a holding table for holding the substrate, a rotation driving source for rotating the substrate held by rotating the holding table, and the holding table An atmosphere blocking plate disposed to face one main surface of the substrate held on the substrate, a gas supply means for supplying gas toward the one main surface, and the holding table rotated to adhere to the substrate A rotation control means for controlling the rotation drive source so as to stop the rotation of the holding table after the liquid is scattered; and at least the liquid that has adhered to the substrate by scattering the liquid by rotating the holding table. Gas supply control means for controlling the gas supply means so as to supply the gas to the substrate.The gas supply control means supplies the gas to the substrate during the drying process performed after the rotation control means stops the rotation of the holding table..
[0015]
  Claim6The invention of claim 1 to claim 15The substrate processing apparatus according to claim 1, wherein the gas is a mixed gas of heated nitrogen gas and organic solvent vapor, and the concentration of the organic solvent vapor is a saturated vapor pressure at the same temperature as the substrate. The concentration is lower than the concentration.
[0016]
  Claim7The invention of claim 1 to claim 164. The substrate processing apparatus according to claim 1, further comprising means for rotating the atmosphere blocking plate in accordance with the rotation of the holding table.
[0017]
  Claim8The invention of claim 1 to claim 174. The substrate processing apparatus according to claim 1, further comprising means for supplying the gas toward another main surface of the substrate held from the holding table.
[0018]
  Claim9The invention of claim 1 to claim 184. The substrate processing apparatus according to claim 1, wherein the gas supply control unit changes a flow rate of the gas supplied to the substrate in accordance with a rotation speed of the holding table.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
<1. First Embodiment>
FIG. 1 is a diagram showing a mechanical configuration of a substrate processing apparatus 100 according to a first embodiment of the present invention, and FIG. 2 is a block diagram showing a configuration of a control system of the substrate processing apparatus 100. FIG. 3 is a time chart showing the operation of the substrate processing apparatus 100 by the control system shown in FIG.
[0020]
As shown in FIG. 1, the substrate processing apparatus 100 includes a holding table 121 that holds the substrate 9, a motor 131 that is a driving source that rotates the holding table 121, a cup 104 that surrounds the side periphery of the holding table 121, and the holding table 121. An atmosphere blocking plate 151 disposed above and facing the holding table 121, a pure water supply unit 161 that supplies pure water from the center of the atmosphere blocking plate 151 toward the substrate 9 held on the holding table 121, and the atmosphere The gas supply unit 171 supplies a processing gas which is a mixed gas of nitrogen gas and IPA vapor heated from the center of the blocking plate 151 toward the substrate 9.
[0021]
As shown in FIG. 2, the control unit 108 that controls the operation of the substrate processing apparatus 100 includes a motor control unit 132 that controls the rotation of the motor 131 and pure water that controls the amount of pure water supplied by the pure water supply unit 161. A supply control unit 162 and a gas supply control unit 172 for controlling the supply amount of the processing gas by the gas supply unit 171 and the concentration of IPA vapor in the processing gas are provided, and the motor control unit 132 and the pure water supply control unit are provided. 162 and the gas supply control unit 172 are connected to the motor 131, the pure water supply unit 161, and the gas supply unit 171, respectively.
[0022]
Next, the role of each part of the substrate processing apparatus 100 will be described.
[0023]
Three pins 122 are provided on the holding table 121, and the substrate 9 is held in a horizontal posture by the engagement of the three pins 122 and the outer edge portion of the substrate 9. A rotating shaft 123 that faces in the vertical direction is connected to the center of the lower surface of the holding stand 121, and the other end of the lower portion of the rotating shaft 123 is connected to the rotating shaft of the motor 131.
[0024]
With such a configuration, when the motor 131 rotates in response to a control signal from the motor control unit 132, the substrate 9 rotates in a horizontal plane together with the holding base 121 in a horizontal posture. That is, in the substrate processing apparatus 100, the substrate 9 rotates about the axis perpendicular to the main surface passing through the center as the center axis.
[0025]
The atmosphere blocking plate 151 facing the upper surface, which is one main surface of the substrate 9, is of a size that always covers the upper surface of the rotating substrate 9, and the atmosphere blocking plate 151 is supported by a support shaft 152 connected to the upper portion. In this way, it is fixedly arranged.
[0026]
The support shaft 152 is a hollow tube, and a double-structure tube composed of an inner tube 161a and an outer tube 171a is inserted therein. The end portion of the double structure tube is exposed to the lower surface of the atmosphere blocking plate 151 along the substantially center of the atmosphere blocking plate 151, that is, along the axis of the rotation center of the substrate 9.
[0027]
The inner tube 161a is connected to a pure water supply unit 161, and pure water supplied from the pure water supply unit 161 is supplied to approximately the center of the upper surface of the substrate 9 through the inner tube 161a. When pure water is supplied to the substrate 9, the substrate 9 rotates together with the holding base 121, and the supplied pure water flows along the upper surface of the substrate 9 in the outer peripheral direction, so that the substrate 9 is cleaned. The pure water used for cleaning scattered from the outer edge of the substrate 9 is received by the cup 104 covering the periphery of the substrate 9 and collected.
[0028]
On the other hand, the outer tube 171a is connected to the gas supply unit 171, and the processing gas is supplied to the space between the outer tube 171a and the inner tube 161a. As a result, the processing gas can be supplied from substantially the center of the lower surface of the atmosphere shielding plate 151 to the upper surface of the substrate 9.
[0029]
In addition, a thermocouple for measuring the temperature of the atmosphere blocking plate 151 is attached to the atmosphere blocking plate 151 as a thermometer 154. The temperature measured by the thermometer 154 is considered to be equal to the temperature of the substrate 9 and is transmitted to the gas supply control unit 172 shown in FIG. The temperature from the thermometer 154 is used in the gas supply control unit 172 to control the concentration of IPA vapor in the process gas.
[0030]
As described above, the substrate processing apparatus 100 can supply pure water to the substrate 9 and can perform not only the drying process described later but also the pure water cleaning of the substrate 9. It is a device that can. Note that the substrate processing apparatus 100 may be further provided with other components such as supplying a chemical solution. In this case, the substrate processing apparatus 100 performs processing using a chemical solution or the like, a cleaning process, and a drying process after the cleaning process. It becomes the device which performs. For example, a spin developer that supplies a developing solution to develop a photoresist film on the surface of the substrate, or other chemical solution that has a chemical effect such as acid or alkali, or a solution that is pressurized to a high pressure. The apparatus shown in FIG. 1 is provided in various rotary substrate processing apparatuses that perform processes such as supplying a substrate to a substrate, slidingly contacting the substrate surface with a brush, and supplying an ultrasonically vibrating liquid to the substrate surface. It may be.
[0031]
Next, a process gas supply operation and a substrate 9 rotation operation in the drying process after the pure water cleaning by the substrate processing apparatus 100 will be described.
[0032]
FIG. 3 is a time chart showing the operation of the substrate processing apparatus 100. In FIG. 3, the process indicated by reference numeral P1 indicates a part of the cleaning process, and the process indicated by reference numeral P2 indicates a drying process after pure water cleaning. These operations are executed by the motor control unit 132, the pure water supply control unit 162, and the gas supply control unit 172 in the control unit 108 shown in FIG.
[0033]
In the cleaning process, pure water is supplied from the pure water supply unit 161 to the substrate 9 and the substrate 9 is rotated at a low speed of about 500 rpm. Thereby, the pure water supplied to substantially the center of the upper surface of the substrate 9 (that is, the rotation center) flows on the upper surface of the substrate 9 in the outer peripheral direction, and the substrate 9 is cleaned.
[0034]
When the cleaning process is completed (time TM1 shown in FIG. 3), the pure water supply operation is stopped and the substrate 9 is rotated at a high speed of about 1500 to 3000 rpm for 2 to 3 seconds. As a result, most of the pure water adhering to the substrate 9 is shaken off by the centrifugal force and quickly removed. Although most of the pure water is removed from the substrate 9 by this high speed rotation, minute water droplets still remain in the minute holes existing on the surface of the substrate 9 and the steps (steps) formed on the surface of the substrate 9. It will remain.
[0035]
Further, simultaneously with the completion of the cleaning process (time TM1), the process gas is supplied from the gas supply unit 171 to the upper surface of the substrate 9 at about 100 liters / minute.
[0036]
When the substrate 9 is rotated at a high speed for 2 to 3 seconds (time TM1 to TM2 shown in FIG. 3), the pure water adhering to the substrate 9 is in a state of only minute water droplets. Thereafter, the rotation speed of the substrate 9 is returned again to a low speed of about 100 to 500 rpm, and the substrate 9 is rotated for 20 to 30 seconds in this state. During this time, the processing gas is continuously supplied from the gas supply unit 171 to the substrate 9.
[0037]
When the above steps are completed (time TM3 shown in FIG. 3), the drying process on the substrate 9 is completed, and the rotation operation of the substrate 9 is stopped and the gas supply operation is also stopped.
[0038]
Next, the state of the substrate processing apparatus 100 and the progress of drying of the substrate 9 in the operation of the drying process shown in FIG. 3 will be described.
[0039]
First, in the process of rotating the substrate 9 at times TM1 to TM2 at a high speed, most of the pure water adhering to the substrate 9 is removed so as to be scattered from the substrate 9. At this time, the processing gas is supplied to the substrate 9 at an amount of 100 liters / minute, but this supply amount is not sufficient to maintain the atmosphere of the upper surface of the substrate 9 in the processing gas atmosphere. It has become a quantity. That is, the high-speed rotation of the substrate 9 and the holding table 121 causes the air existing outside the cup 104 and the atmosphere blocking plate 151 to rotate the substrate 9 and the holding table 121 from the gap G between the cup 104 and the atmosphere blocking plate 151. It enters the inside of the cup 104 so as to be caught.
[0040]
As described above, when the substrate 9 is rotated at a high speed, the atmosphere on the upper surface of the substrate 9 is not maintained in an atmosphere of a sufficient processing gas. However, since the high-speed rotation time is as short as 2 to 3 seconds, the substrate 9 There is no reaction between oxygen and oxygen via pure water, and no watermark is generated.
[0041]
When most of the pure water adhering to the substrate 9 has been removed, that is, from the time TM2, the rotational speed of the substrate 9 decreases and is changed to a low-speed rotation that is relatively low with respect to the high-speed rotation. Since the substrate 9 and the holding table 121 rotating at a low speed have a lower effect of entraining the surrounding airflow than that at the time of high-speed rotation, the atmosphere outside the cup 104 can be transferred to the upper surface of the substrate 9 only by supplying a processing gas of 100 liters / minute. Can be prevented. Thereby, the atmosphere of the upper surface of the substrate 9 can be sufficiently maintained in the atmosphere of the processing gas.
[0042]
By continuing such low-speed rotation and supply of processing gas for 20 to 30 seconds (between times TM2 and TM3), minute water droplets remaining in minute holes and steps on the substrate 9 are dried. Of course, since there is an atmosphere of processing gas in which oxygen does not exist around the water droplets, no watermark is generated when the minute water droplets are dried.
[0043]
FIG. 4 is a time chart for explaining another form of the process gas supply operation and the substrate 9 rotation operation during the drying process of the substrate processing apparatus 100. Note that the times TM1 to TM3 shown in FIG. 4 correspond to those shown in FIG.
[0044]
In the drying operation shown in FIG. 4, similarly to the drying operation shown in FIG. 3, when the cleaning process is completed at time TM1, the substrate 9 is rotated at a high speed of 1500 to 3000 rpm for 2 to 3 seconds. Is not supplied. Then, after the pure water is scattered from the substrate 9 by the high-speed rotation operation, the rotation of the substrate 9 is stopped and the processing gas is supplied at a flow rate of 100 liters / minute for 20 to 30 seconds (time TM2 to TM3).
[0045]
As described above, the time of 2 to 3 seconds during which high-speed rotation is performed is shorter than the time required for the generation of the watermark, and even if oxygen is contained in the atmosphere on the upper surface of the substrate 9 during this period, the substrate No watermark is generated at 9. Therefore, as shown in FIG. 4, stopping the supply of the processing gas during the high-speed rotation of the substrate 9 does not cause a problem. That is, the start of the supply of the processing gas may be any time before the time TM2 (substantially the time TM1 to TM2 since the drying process starts from the time TM1), for example, about 2 seconds from the start of the supply of the processing gas. If the gas supply amount, temperature, components, etc. are stable, the gas supply operation may be performed from time TM1 as shown in FIG. 3, and the processing gas can be stably supplied almost simultaneously with the start of gas supply. If so, the gas supply operation may be performed from time TM2 as shown in FIG. In other words, it is sufficient that the gas is supplied after at least pure water is removed by high-speed rotation.
[0046]
When the removal of most of the pure water on the substrate 9 by high-speed rotation is completed (time TM2), the rotation operation of the substrate 9 is stopped in the drying operation shown in FIG. The rotation of the substrate 9 in the drying operation is an operation performed exclusively to scatter pure water from the substrate 9, and the rotation operation of the substrate 9 is not necessarily required to remove minute water droplets remaining in the holes and steps on the substrate 9. Is not necessary. Further, by stopping the rotation operation of the substrate 9, the surrounding airflow is not engulfed by the rotation of the substrate 9 or the holding table 121, and the atmosphere on the upper surface of the substrate 9 can be easily maintained in the atmosphere of the processing gas. Become.
[0047]
As described above, the drying operation shown in FIG. 4 is a more efficient operation of the rotation operation of the substrate 9 and the supply operation of the processing gas in the drying operation shown in FIG.
[0048]
Next, a method for controlling the concentration of IPA vapor in the processing gas by the gas supply control unit 172 will be described.
[0049]
FIG. 5 is a diagram illustrating the configuration of the gas supply unit 171 and the connection relationship of each configuration centered on the gas supply control unit 172. The gas supply unit 171 includes an evaporation tank 201 that evaporates liquid IPA, first to third pipes 211 to 213, first to fourth temperature sensors 221 to 224, and first to fourth temperature control units 231 to 231. 234, first to fourth heaters 241 to 244, a concentration detection sensor 251, first and second mass flow controllers 261 and 262, and an input unit 207 that receives input from an operator. In the following description, the first to fourth temperature controllers 231 to 234 are referred to as first to fourth TCs (Temperature Controllers) 231 to 234, and the first and second mass flow controllers 261 and 262 are These are referred to as first and second MFCs (Mass Flow Controllers) 261 and 262, respectively. Further, a nitrogen supply source 8 is installed outside the substrate processing apparatus 100. Next, each part related to IPA vapor concentration control will be described more specifically.
[0050]
First, the nitrogen supply source 8 stores nitrogen gas therein. This nitrogen gas is used for various purposes such as warming up piping in a typical substrate processing step, but is mainly used as a carrier gas in the substrate processing apparatus 100. Further, the nitrogen supply source 8 is connected to one end of the first pipe 211, and sends nitrogen gas stored inside to the first pipe 211 when pressurized from the outside.
[0051]
The first pipe 211 first branches the nitrogen gas sent from the nitrogen supply source 8 into two branches. One of the two branched nitrogen gases is guided by a third pipe 213 (described later). The other nitrogen gas is directly guided by the first pipe 211 and supplied to an evaporation tank 201 (described later) connected to the other end of the first pipe 211. A first MFC 261 is interposed in the first pipe 211. The first MFC 261 controls the internal control valve 261a under the control of a gas supply control unit 172 as will be described later, and the flow rate of nitrogen gas led to the first pipe 211 is set to a predetermined flow rate Q._MFC1Adjust to. In addition, a first heater 241 for heating nitrogen gas guided in the first pipe 211 is installed near the other end of the first pipe 211 under the control of the first TC 231 as will be described later. Yes.
[0052]
The evaporation tank 201 stores liquid IPA or other processing liquid in advance, and further includes a second heater 242 for heating the liquid IPA under the control of a second TC 232 as described later. Yes. Further, in the evaporation tank 201, the actual temperature of the liquid IPA is measured, and the measurement result is expressed as T._DET4As a result, a fourth temperature sensor 224 that outputs to the second TC 232 is provided. As a result of heating by the second heater 242, the liquid IPA evaporates in the evaporation tank 201. Further, the evaporation tank 201 is supplied with nitrogen gas (flow rate Q through the first pipe 211)._MFC1) Is supplied. As a result, in the evaporation tank 201, a mixed gas of IPA vapor and nitrogen gas is generated as a processing gas whose concentration is not adjusted. Further, the evaporation tank 201 is connected to one end of the second pipe 212, and sends the processing gas having an unadjusted concentration generated therein to the second pipe 212. The flow rate of the processing gas delivered to the second pipe 212 is the same as the flow rate of the IPA vapor._IPAQ_MFC1+ Q_IPAIt becomes.
[0053]
As described above, the third pipe 213 has one end connected to the first pipe 211 and guides one of the two branched nitrogen gases. The other end of the third pipe 213 is connected to the second pipe 212. A second MFC 262 is interposed in the third pipe 213. The second MFC 262 controls the internal control valve 262a under the control of a gas supply control unit 172 as described later, and the flow rate of the nitrogen gas led to the third pipe 213 is set to a predetermined flow rate Q._MFC2Adjust to. In addition, a third heater 243 for heating nitrogen gas guided in the third pipe 213 is installed near the other end of the third pipe 213 under the control of a third TC 233 as will be described later. Yes.
[0054]
The other end of the second pipe 212 is connected to the outer tube 171a penetrating the atmosphere blocking plate 151, and guides the processing gas to be discharged from the outer tube 171a. First, in the vicinity of one end of the second pipe 212 (in the vicinity of the evaporation tank 201), the actual temperature of the unadjusted processing gas immediately after being sent out from the evaporation tank 201 is measured, and the measurement result is displayed. T_DET1As a first temperature sensor 221 that outputs to the first and second TCs 231 and 232 is installed. This T_DET1Is used when the first and second TCs 231 and 232 control the temperature of the first and second heaters 241 and 242. Further, a third pipe 213 is connected in the vicinity of one end of the second pipe 212. The processing gas delivered from the evaporation tank 201 at this connection position is diluted with nitrogen gas guided by the third pipe 213, and the flow rate of the diluted processing gas (hereinafter referred to as the total flow rate) is Q_MFC1+ Q_MFC2+ Q_IPA= Q_totalIt becomes. By the way, the processing gas immediately after being sent out from the evaporation tank 201 is saturated vapor and is likely to condense. However, the IPA vapor contained in the processing gas is diluted by the nitrogen gas guided through the third pipe 213. Is less likely to condense. From the viewpoint of preventing condensation of IPA vapor, the third pipe 213 is preferably connected to the second pipe 212 as close to the evaporation tank 201 as possible.
[0055]
Further, in the vicinity of the connection position of the second and third pipes 212 and 213, the actual temperature of the process gas diluted at the connection position is measured, and the measurement result is expressed as T._DET2As a result, a second temperature sensor 222 that outputs to the third TC 233 is installed. This T_DET2Is used when the third TC 233 controls the temperature of the third heater 243. In addition, the actual concentration of the IPA vapor contained in the diluted process gas is measured near the other end (at the atmosphere blocking plate 151 side) of the second pipe 212, and the measurement result is expressed as C._DETAs a concentration detection sensor 251 for output to the gas supply control unit 172. This C_DETIs used when the gas supply control unit 172 controls the flow rates of the first and second MFCs 261 and 262. The concentration detection sensor 251 is typically an optical type or a combustion type. Also, the vicinity of the other end of the second pipe 212 is heated by a fourth heater 244 for heating the diluted process gas and a fourth heater 244 under the control of a fourth TC 234 as will be described later. The actual temperature of the treated gas is measured and the measurement result is T_DET3And a third temperature sensor 223 that outputs to the fourth TC 234. This T_DET3Is used when the fourth TC 234 controls the fourth heater 244.
[0056]
The diluted process gas guided through the second pipe 212 is finally discharged from the atmosphere blocking plate 151 to the substrate 9 and used as a process gas whose concentration is adjusted during the above-described drying process.
[0057]
Next, the gas supply control unit 172 will be described. As shown in FIG. 6, a CPU 301, a ROM 302, a RAM 303, and an interface unit 304 are communicably connected to the gas supply control unit 172. The CPU 301 comprehensively controls the operation of the substrate processing apparatus 100 as described later. The ROM 302 stores a control program 321 for the operation of the substrate processing apparatus 100. The RAM 303 is used as a work area for the operation of the CPU 301. The interface unit 304 is communicably connected to the first to fourth TCs 231 to 234, the concentration detection sensor 251, the first and second MFCs 261 and 262, and the input unit 207 outside the gas supply control unit 172. The input unit 207 includes a display, a keyboard, and the like. Thereby, a target parameter serving as a target value for control of the substrate processing apparatus 100 is set by an operator.
[0058]
Operations such as concentration control by the gas supply unit 171 and the gas supply control unit 172 configured as described above will be described below. In the following description, it is pointed out in advance that the gas supply control unit 172 operates using the RAM 303 as a work area in accordance with the control program 321 stored in the ROM 302 in advance.
[0059]
First, the CPU 301 is included in the control program 321, starts a processing program (so-called recipe) for setting the target parameter described above, and displays a screen for setting the target parameter on the display of the input unit 207. indicate. In response to this display, when the above-mentioned screen is displayed on the display of the input unit 207, the operator must set various target parameters. Total flow rate Q of the processing gas discharged from the tube 171a (the gap between the outer tube 171a and the inner tube 161a, the same applies hereinafter)_totalThe temperature T of the processing gas discharged from the outer tube 171a_gasAnd concentration C of IPA vapor contained in the processing gas_IPAIt is. The substrate processing apparatus 100 determines the concentration and temperature of the processing gas supplied to the substrate 9 as three target parameters Q._total, T_gasAnd C_IPABy adjusting based on the above, processing as desired by the operator is performed on the substrate 9. The CPU 301 receives the three target parameters set by the operator from the input unit 207 via the interface unit 304 and then stores them in the RAM 303. Thereafter, a cleaning process and a drying process by the substrate processing apparatus 100 are started. The steps of these treatments are as described above, but will be described below focusing on the concentration control of the IPA vapor in the treatment gas in the drying step.
[0060]
As a preliminary process before the drying process is started or as a preliminary process in the first stage of the drying process, the CPU 301 of the gas supply control unit 172 executes a standby process according to the control program 321. First, the CPU 301 sets a constant temperature T preset in the control program 321.₀Is notified to the first to third TCs 231 to 233 via the interface unit 304. This constant temperature T₀Is selected to be an appropriate temperature in relation to the saturated vapor pressure of the liquid IPA stored in the evaporation tank 201 (for example, about 66 ° C.). That is, constant temperature T₀Is a relatively low value, the saturated vapor pressure also becomes low, and it becomes difficult to secure the flow rate of the IPA vapor generated in the evaporation tank 201 in the drying process. As a result, the total flow rate Q of the processing gas set by the operator_totalAnd the concentration C of IPA vapor contained therein_IPAThe problem that it becomes difficult to ensure is generated. Therefore, constant temperature T₀Is preferably selected at an appropriate temperature so that such a problem does not occur. In the present embodiment, from the viewpoint of simplifying the explanation, the control program 321 includes the constant temperature T.₀Is assumed to be preset, but this constant temperature T₀The substrate processing apparatus 100 may be configured to be set through the input unit 207 by the operator.
[0061]
The first to third TCs 231 to 233 are the constant temperature T notified by the CPU 301.₀And the heating temperature of the first to third heaters 241 to 243 is set to a constant temperature T.₀Adjust to. As a result, the first heater 241 moves the first pipe 211 to a constant temperature T.₀The second heater 242 causes the liquid IPA in the evaporation tank 201 to be heated at a constant temperature T.₀The third heater 243 causes the third pipe 213 to be heated at a constant temperature T.₀Start heating at. Such heating is performed throughout the drying process.
[0062]
In the standby process, the minute flow rate Q preset in the control program 321₀(For example, 10 [l / min]) of nitrogen gas is introduced into the third pipe 213 and the second pipe 212. This minute flow rate Q₀Since the nitrogen gas is heated by the third heater 243, the second pipe 212 is heated. As a result, even if the processing gas containing IPA vapor is guided through the second pipe 212 in the drying process, the IPA vapor is less likely to condense. In this standby process, since no IPA vapor is required, a very small amount of nitrogen gas is not led to the first pipe 211.
[0063]
In the case of the example of the drying operation shown in FIG. 4, while the standby process is continued, the substrate 9 is rotated at a high speed on the holding stand 121 side in parallel to remove the pure water adhering to the substrate 9 ( Time TM1-TM2 shown in FIG. The standby process may be performed during the cleaning process performed prior to the drying process. Further, when the substrates 9 are successively processed one by one, the standby process may be performed only when the apparatus is started up.
[0064]
When the standby process is completed and the high-speed rotation of the substrate 9 is performed for 2 to 3 seconds, a processing gas whose concentration of IPA vapor described below is adjusted is discharged onto the substrate 9 (time TM2 shown in FIG. 4). TM3). The IPA contained in the process gas evaporates after being replaced with pure water droplets remaining on the surface of the substrate 9. As a result, the substrate 9 is sufficiently dried without leaving droplets on the surface. In this way, the drying process is performed in the substrate processing apparatus 100.
[0065]
Next, the concentration control of the IPA vapor in the processing gas will be described in detail.
[0066]
As described above, the total flow rate Q is previously stored in the RAM 303 (working area) of the gas supply control unit 172._total, Temperature T_gasAnd concentration C_IPAIs stored. When generating the processing gas necessary for the drying process, the CPU 301 of the gas supply control unit 172 first introduces nitrogen introduced into the first pipe 211 in order to initially set the concentration of the IPA vapor contained in the processing gas. Gas flow rate Q_MFC1, And the flow rate Q of nitrogen gas led to the third pipe 213_MFC2Is determined according to the control program 321. Therefore, the CPU 301 determines the total flow rate Q currently stored in the RAM 303._totalAnd concentration C_IPAAnd the flow rate Q of the IPA vapor that must be contained in the processing gas supplied to the substrate 9 this time._IPAAsk for. For example, according to the recipe described above by the operator, Q_total100 [l / min] and concentration C_IPAIs set to 5%. According to this assumption, the flow rate Q_IPAIs 5 [l / min].
[0067]
Concentration C by operator_IPAThis setting may be performed with the assistance of the gas supply unit 171 shown in FIG. As shown in FIG. 5, the temperature of the atmosphere blocking plate 151 measured by the thermometer 154 is input to the gas supply control unit 172. Since the atmosphere blocking plate 151 and the substrate 9 are close to each other, the temperature T of the substrate 9_WThere is no significant difference between the temperature of the atmosphere blocking plate 151 and the temperature of the atmosphere blocking plate 151. Therefore, the gas supply control unit 172 refers to a table 322 (FIG. 7), which will be described later, and obtains a concentration at which the IPA vapor reaches the saturated vapor pressure at the temperature from the thermometer (hereinafter referred to as “saturated concentration”). To display. Here, for example, when the temperature is 25 ° C., the saturation concentration of the IPA vapor is 5.85%, so the operator inputs 5%, which is a value lower than 5.85%. Thereby, even if the processing gas having the IPA vapor concentration of 5% is discharged to the substrate 9, it is possible to prevent the IPA vapor from condensing on the surface of the substrate 9. As a result, an appropriate drying process can be performed.
[0068]
By the way, as described above, the liquid IPA in the evaporation tank 201 has a constant temperature T.₀(In this embodiment, it is heated to 66 ° C. The saturated vapor pressure of IPA vapor has a unique value with respect to temperature. Now, this constant temperature T₀The saturation concentration of IPA vapor, which is the saturated vapor pressure below, is X₀%. Also, the saturation concentration of IPA vapor is the required IPA flow rate Q_IPAAnd the flow rate of the processing gas sent from the evaporation tank 201 (Q_MFC1+ Q_IPA)), The formula 1 holds, and Q_MFC1Is obtained by Equation 2.
[0069]
[Expression 1]

[0070]
[Expression 2]

[0071]
Here, saturation concentration X of IPA vapor₀Is a known physical quantity, and in the present embodiment, the control program 321 has a temperature T as shown in FIG.₀Saturation concentration X against₀The table 322 (see FIG. 7) in which the values of are previously described is included in advance. As described in the table 322 (see FIG. 7), the saturation concentration X₀Is the temperature T₀Assume 50% at = 66 ° C. Here, this saturation concentration X₀Note that is not a correct value and assumes such a value for the sake of simplicity. According to this assumption, Q_MFC1Is 5 [l / min].
[0072]
Further, the processing gas (flow rate Q_MFC1+ Q_IPA) Is a nitrogen gas (flow rate Q) guided by the third pipe 213 at the connection position of the second pipe 212 and the third pipe 213._MFC2). Therefore, the total flow rate Q of the processing gas finally supplied to the substrate 9_totalQ is expressed by Equation 3, so Q_MFC2Is obtained from Equation 4.
[0073]
[Equation 3]

[0074]
[Expression 4]

[0075]
According to the above assumption, from the above equation 4, Q_MFC2Is 90 [l / min].
[0076]
The CPU 301 of the gas supply control unit 172 determines the flow rate Q obtained as described above._MFC1(5 [l / min] in the present embodiment) is notified to the first MFC 261 via the interface unit 304, and the flow rate Q_MFC2(90 [l / min] in this embodiment) is notified to the second MFC 262 via the interface unit 304. The first and second MFCs 261 and 262 receive the notified flow rate Q_MFC1And Q_MFC2In accordance with the flow rate Q in the first and third pipes 211, 213_MFC1And Q_MFC2To open the internal control valves 261a and 262a.
[0077]
Thereafter, the nitrogen supply source 8 sends out nitrogen gas at a predetermined flow rate and at room temperature. The nitrogen gas delivered from the nitrogen supply source 8 is branched into two immediately after and is guided by the first and third pipes 211 and 213. First, the nitrogen gas introduced into the first pipe 211 is flowed by the first MFC 261 at a flow rate Q._MFC1And a constant temperature T by the first heater 241.₀After being heated to become, it is introduced into the evaporation tank 201. As described above, IPA vapor is generated in the evaporation tank 201. When nitrogen gas (carrier gas) is introduced into the evaporation tank 201 generating IPA vapor, a processing gas, that is, a mixed gas of IPA vapor and nitrogen gas is generated. The generated processing gas is sent from the evaporation tank 201 to the second pipe 212. On the other hand, the nitrogen gas introduced into the third pipe 213 is flowed by the second MFC 262 at a flow rate Q._MFC2And a constant temperature T by the third heater 243.₀After being heated, the second pipe 212 is introduced.
[0078]
Therefore, the processing gas sent from the evaporation tank 201 is diluted by the nitrogen gas guided through the third pipe 213 at the connection position between the second pipe 212 and the third pipe 213, and as a result, The flow rate of the diluted process gas is (Q_MFC1+ Q_MFC2+ Q_IPA) = Q_totalIn addition, the concentration of IPA vapor in the diluted process gas is Q, as is apparent from the above._IPA/ (Q_MFC1+ Q_MFC2+ Q_IPA) = C_IPAIt becomes. The diluted processing gas is introduced into the second pipe 212 and eventually the temperature T is increased by the fourth heater 244._gasThen, the temperature is raised to the substrate 9 from the outer tube 171a. As a result, the above-described drying process is executed in the substrate processing apparatus 100. As apparent from the above description, the temperature of the processing gas supplied to the substrate 9 is T_gasThe concentration of IPA vapor contained in the process gas is C_IPAThe total flow rate of the processing gas is Q_totalIt is. These are the target parameters themselves set by the operator. Thus, in the substrate processing apparatus 100, the concentration of the IPA vapor in the processing gas is determined by the ratio of the flow rates of the first and third pipes 211 and 213 to the total flow rate, and the liquid IPA in the evaporation tank as in the prior art. The temperature is not determined. As described above, the substrate processing apparatus 100 can control the concentration of IPA vapor in the processing gas without changing the evaporation condition of liquid IPA having a large heat capacity, and thus quickly controls the concentration of IPA vapor as desired by the operator. be able to.
[0079]
In the substrate processing apparatus 100, the processing gas is generated as described above, and is supplied to the substrate 9 from the outer tube 171a. Furthermore, the substrate processing apparatus 100 generates the processing gas, and the concentration of the IPA vapor contained in the processing gas supplied to the substrate 9 and the heating temperatures of the first to fourth heaters 241 to 244 are generated throughout the generation of the processing gas. Is controlled as follows.
[0080]
First, IPA vapor concentration control will be described. As described above, the concentration detection sensor 251 is provided on the second pipe 212. This concentration detection sensor 251 constantly measures the concentration of IPA vapor contained in the processing gas supplied to the substrate 9, and the measurement result is expressed as C._DETTo the gas supply control unit 172. The CPU 301 (see FIG. 6) of the gas supply control unit 172 receives the C via the interface unit 304._DETReceive. Further, the RAM 303 of the gas supply control unit 172 stores C, which is the concentration of the IPA vapor necessary this time set by the operator._IPA(Target value) is held. CPU301 is C which is target value_IPAAnd actual concentration C_DETBased on the deviation between the first MFC 261, a PID (Proportional-plus-integral-plus-derivative) operation is preferably performed to fine tune the flow rate of the first MFC 261. As described above, the flow rate of the first MFC 261 depends on the measurement result C of the concentration detection sensor 251._DETBased on the feedback control. Here, the flow rate Q of the first MFC 261_MFC1And finely adjust the flow rate Q of the second MFC262._MFC2Is not finely adjusted, the total flow rate Q of the processing gas supplied to the substrate 9_totalWill change. However, since the adjustment amount of the first MFC 261 is very small, the flow rate Q of the second MFC 262 is small._MFC2Is finely adjusted to always maintain a constant total flow rate Q._totalThere is little need to get. However, constant total flow rate Q_totalSo that the flow rate Q of the second MFC 262 can be obtained._MFC2May be finely adjusted.
[0081]
Thus, the substrate processing apparatus 100 directly measures the current concentration of the IPA vapor, and based on the measurement result, at least the flow rate Q of the first MFC 261._MFC1Feedback control to fine-tune As a result, the substrate 9 can be dried as desired by the operator.
[0082]
Next, temperature control of the first heater 241 will be described. As described above, the first temperature sensor 221 is provided on the second pipe 212. The first temperature sensor 221 constantly measures the actual temperature of the processing gas immediately after being sent out from the evaporation tank 201, and the measurement result is expressed as T._DET1Is output to the first TC 231. The first TC 231 has a constant temperature T notified by the CPU 301.₀Is held. The first TC 231 has a constant temperature T₀And the actual temperature T_DET1Feedback control for finely adjusting the heating temperature of the first heater 241 is preferably performed based on the deviation between the first heater 241 and the PID operation. As described above, the nitrogen gas guided through the first pipe 211 has a constant temperature T of the processing gas sent from the evaporation tank 201.₀Thus, the concentration of the IPA vapor determined by the temperature of the processing gas can be controlled to a constant concentration as desired by the operator. Therefore, in the substrate processing apparatus 100, the IPA vapor concentration change is less likely to occur due to the introduction of nitrogen gas into the evaporation tank 201 as in the conventional case. As a result, the substrate 9 can be dried as desired by the operator.
[0083]
Next, temperature control of the second heater 242 will be described. The above-described first temperature sensor 221 has T_DET1Is also output to the second TC 232. The second TC 232 also has a constant temperature T as described above.₀Is held. Similarly to the first TC 231, the second TC 232 also preferably performs a PID operation to execute feedback control for finely adjusting the heating temperature of the second heater 242. As described above, the liquid IPA stored in the evaporation tank 201 has the temperature T of the processing gas sent from the evaporation tank 201 at a constant temperature T.₀Therefore, the concentration of the IPA vapor determined by the temperature of the processing gas can be controlled to a constant temperature as desired by the operator. As a result, the substrate 9 can be dried as desired by the operator.
[0084]
Next, temperature control of the third heater 243 will be described. As described above, the second temperature sensor 222 is provided in the second pipe 212. The second temperature sensor 222 has a diluted process gas (flow rate Q_total) Is always measured, and the measurement result is T_DET2To the third TC 233. As described above, the third TC 233 also has a constant temperature T.₀Is held. The third TC 233 has a constant temperature T₀And the actual temperature T_DET2Based on the deviation between the first heater and the second heater, the above-described PID operation is preferably executed, and feedback control for finely adjusting the heating temperature of the third heater 243 is executed. As described above, the nitrogen gas guided through the third pipe 213 has a constant temperature T of the diluted processing gas.₀Therefore, the temperature of the diluted process gas is not lowered. Therefore, the concentration of the IPA vapor determined by the temperature of the diluted process gas can be controlled to a constant concentration as desired by the operator. As a result, the substrate 9 can be dried as desired by the operator.
[0085]
As described above, the substrate processing apparatus 100 is guided through the second pipe 212 instead of controlling the concentration of the IPA vapor in the processing gas based on the temperature of the liquid IPA stored in the evaporation tank 201. The concentration of the processing gas itself is measured, and based on the measurement result, the flow rate of the nitrogen gas guided through the first pipe 211 is at least finely adjusted to control the concentration of the IPA vapor in the processing gas. Therefore, the substrate processing apparatus 100 can perform a drying process on the substrate 9 as desired by the operator. In the concentration control of the IPA vapor, the temperature of the liquid IPA and the nitrogen gas guided through the first pipe 211 are set at a constant temperature T based on the temperature of the processing gas immediately after being sent out from the evaporation tank 201.₀Is feedback controlled. As a result, the temperature of the liquid IPA in the evaporation tank 201 does not easily change even when nitrogen gas is introduced into the evaporation tank 201. That is, the IPA vapor in the processing gas always has the concentration desired by the operator. The substrate processing apparatus 100 can perform a drying process on the substrate 9 as desired by the operator.
[0086]
Next, temperature control of the fourth heater 244 will be described. As described above, the third temperature sensor 223 is provided on the second pipe 212. The third temperature sensor 223 has a diluted process gas (flow rate Q_total) Is always measured, and the measurement result is T_DET3To the fourth TC 234. As described above, the fourth TC 234 includes the temperature T of the processing gas supplied to the substrate 9._gasIs held. The fourth TC 234 has a predetermined temperature T_gasAnd the actual temperature T_DET4Based on the deviation between the first heater and the second heater, the above-described PID operation is preferably executed, and feedback control for finely adjusting the heating temperature of the fourth heater 244 is executed. Thus, the fourth heater 244 is feedback-controlled based on the actual temperature of the processing gas supplied to the substrate 9 immediately before the discharge port of the outer tube 171a. Therefore, the temperature of the processing gas is always the temperature T desired by the operator._gasTo be kept. In the drying process described above, not only the concentration of the IPA vapor in the processing gas but also the temperature of the processing gas is related to the drying time of the substrate 9. That is, the temperature of the substrate 9 itself rises depending on the temperature of the supplied processing gas, and it is possible to evaporate liquid droplets that have entered a fine groove or the like formed in the substrate 9. Thereby, the drying process as expected by the operator can be more suitably performed on the substrate 9.
[0087]
In general, the temperature T of the substrate 9 at the start of the drying process._WTemperature T of the processing gas discharged_gasSince the temperature is higher, the temperature of the substrate 9 rises during the drying process but does not decrease. Therefore, if a concentration lower than the saturation concentration of the IPA vapor of the processing gas at the temperature of the substrate 9 at the start of the drying process is set, the concentration of the IPA vapor is always kept below the saturation concentration even during the drying process. Be drunk.
[0088]
Next, when a series of substrate processing steps are completed and the process proceeds to a new substrate processing step, the substrate processing apparatus 100 changes the concentration of IPA vapor in the processing gas while keeping the total flow rate of the processing gas constant. For this purpose, the following operation is executed. First of all, the operator follows the above-mentioned recipe and creates three new target parameters Q._total, T_gasAnd C_IPASet. Next, the substrate processing apparatus 100 performs a standby process and proceeds to a drying process after the cleaning process. At the time of shifting to the drying process, the total flow rate Q is stored in the RAM 303 (working area) of the substrate processing apparatus 100._total, Temperature T_gasAnd concentration C_IPAIs stored. As described above, the substrate processing apparatus 100 first starts the flow rate Q._MFC1And flow rate Q_MFC2Is initialized. Therefore, the CPU 301 uses the total flow rate Q_totalAnd concentration C_IPAMultiplied by the flow rate Q_IPAAsk for. For example, this time the operator follows the recipe_totalIs 100 [l / min], and the saturation concentration of the IPA at the measurement temperature of the substrate 9 exceeds 10%._IPAIs set to 10%, the flow rate Q_IPAIs 10 [l / min].
[0089]
The liquid IPA in the evaporation tank 201 has a constant temperature T₀(Saturation concentration X₀%). At this time, Q_MFC1Is 10 [l / min] from Equation 2. Q_MFC2Is 80 [l / min] from Equation 4. The first MFC 261 and the second MFC 262 of the substrate processing apparatus 100 determine the flow rate Q determined as described above._MFC1(10 [l / min] in this embodiment) and flow rate Q_MFC2The internal control valves 261a and 262a are opened so that (80 [l / min] in this embodiment) is obtained.
[0090]
As described above, the substrate processing apparatus 100 changes the flow rate of the nitrogen gas introduced into the evaporation tank 201 and the flow rate of the nitrogen gas guided through the third pipe 213, thereby keeping the total flow rate of the process gas constant. The concentration of IPA vapor in the process gas can be changed. Thus, in the substrate processing apparatus 100, it is not necessary to change the temperature of the liquid IPA having a large heat capacity (stored in the evaporation tank 201). Therefore, according to the substrate processing apparatus 100, it can transfer to the next substrate processing process easily in a short time.
[0091]
Similarly, when shifting from the previous substrate processing step to a new substrate processing step, the substrate processing apparatus 100 can change the total flow rate of the processing gas while keeping the concentration of the IPA vapor in the processing gas constant. The following operations are performed. First of all, the operator follows the above-mentioned recipe and creates three new target parameters Q._total, T_gasAnd C_IPASet. Next, the substrate processing apparatus 100 performs a standby process and proceeds to a drying process after the cleaning process. At this time, the total flow rate Q is stored in the RAM 303 (working area) of the substrate processing apparatus 100._total, Temperature T_gasAnd concentration C_IPAIs stored. As described above, the substrate processing apparatus 100 starts with the flow rate Q first._MFC1And flow rate Q_MFC2Is initialized. Therefore, the CPU 301 uses the total flow rate Q_totalAnd concentration C_IPAMultiplied by the flow rate Q_IPAAsk for. For example, this time the operator_totalIs set to 200 [l / min] and the concentration C_IPAIs set to 10%. According to this assumption, the flow rate Q_IPAIs 20 [l / min].
[0092]
The liquid IPA in the evaporation tank 201 has a constant temperature T₀(Saturation concentration X₀) Is heated. At this time, Q_MFC1Is 20 [l / min] from Equation 2. Q_MFC2Is 160 [l / min] from Equation 4. The first MFC 261 and the second MFC 262 of the substrate processing apparatus 100 determine the flow rate Q determined as described above._MFC1(20 [l / min] in this embodiment) and flow rate Q_MFC2The internal control valves 261a and 262a are opened so that (in this embodiment, 160 [l / min]) is obtained.
[0093]
As described above, the substrate processing apparatus 100 changes the flow rate of the nitrogen gas introduced into the evaporation tank 201 and the flow rate of the nitrogen gas guided through the third pipe 213 to make the concentration of the IPA vapor in the process gas constant. The total flow rate of the processing gas can be changed while maintaining
[0094]
Thus, in the substrate processing apparatus 100, it is not necessary to change the temperature of the liquid IPA having a large heat capacity (stored in the evaporation tank 201). Therefore, according to the substrate processing apparatus 100, it is possible to easily shift to the next substrate processing step in a short time.
[0095]
Note that in the substrate processing apparatus 100 described above, the first temperature sensor 221 detects the detection result T._DET1To the first and second TCs 231 and 232, and the first and second TCs 231 and 232_DET1Based on the above, the heating temperatures of the first and second heaters 241 and 242 are feedback-controlled. However, the substrate processing apparatus 100 may use a concentration detection sensor instead of the first temperature sensor 221 in order to feedback control the heating temperatures of the first and second heaters 241 and 242. This concentration detection sensor measures the actual concentration of IPA contained in the processing gas sent from the evaporation tank 201. As described above, since the processing gas immediately after being sent out from the evaporation tank 201 is saturated steam, the temperature of the processing gas can be uniquely determined if the concentration of the IPA vapor can be measured. Therefore, the first and second TCs 231 and 232 can also feedback control the heating temperatures of the first and second heaters 241 and 242 based on the measurement results of the concentration detection sensors.
[0096]
Further, in the substrate processing apparatus 100 described above, the concentration detection sensor 251 has the measurement result C_DETIs output to the gas supply control unit 172, and the gas supply control unit 172_DETBased on the above, at least the flow rate of the first MFC 261 is feedback controlled. However, the gas supply control unit 172 performs at least feedback control of the flow rate of the first MFC 261 to detect the detection result C of the concentration detection sensor 251._DETRather, the measurement result T of the first temperature sensor 221 or the second temperature sensor 222_DET1Or T_DET2May be used. As described above, the first temperature sensor 221 and the second temperature sensor 222 have a constant temperature (T in the above-described embodiment).₀) To measure the temperature of the process gas controlled. As is clear from the above, a constant temperature (T₀) Can be measured, the concentration of IPA contained in the processing gas guided through the second pipe 212 is uniquely determined. Therefore, the gas supply control unit 172 determines at least the flow rate Q of the first MFC 261 based on the measurement result of the first temperature sensor 221 or the second temperature sensor 222._MFC1Can also be feedback controlled.
[0097]
Further, in the substrate processing apparatus 100 described above, the third temperature sensor 223 has the measurement result T_DET3To the fourth TC 234, and the fourth TC 234_DET3Based on the above, the heating temperature of the fourth heater 244 is feedback-controlled. However, the substrate processing apparatus 100 uses the measurement result T of the third temperature sensor 223 for such feedback control._DET3Instead of the measurement result T of the second temperature sensor 222._DET2May be used. Thus, the measurement result T_DET2Can be used because both the second temperature sensor 222 and the third temperature sensor 223 determine the temperature of the diluted process gas introduced into the second pipe 212.
[0098]
In the above-described embodiment, the IPA vapor has been specifically described. However, in each manufacturing process of semiconductor devices and the like, not only IPA vapor but also organic solvent vapor and water vapor are used as treatment vapor. These process steams are also often used after being mixed with a carrier gas, and the concentration of the process steams also needs to be accurately controlled. The substrate processing apparatus 100 can also be applied to these processing vapors.
[0099]
As described above, the gas supply unit 171 measures various physical elements of the gas flowing from the nitrogen supply source 8 to the discharge port of the outer tube 171a, and uses the measured value as the concentration of IPA vapor in the processing gas. It can be used as a density control parameter for control. In addition, when controlling the concentration of the IPA vapor, physical elements of gas flowing through various places can be adopted as the control target.
[0100]
As described above, the measured value of the concentration of IPA vapor in the gas flowing from the connection position of the second pipe 212 to the third pipe 213 to the discharge port can be directly used as a concentration control parameter. it can.
[0101]
Further, when the flow rates of the gas flowing through the first and third pipes 211 and 213 are known, the connection position between the evaporation tank 201 and the third pipe 213 in the second pipe 212 as described above. Since the concentration of the IPA vapor in the process gas can also be obtained from the measured value of the concentration of the IPA vapor in the gas during the period, it can be used as a concentration control parameter.
[0102]
Further, the temperature of the liquid IPA in the evaporation tank 201, the temperature of the gas flowing through the first pipe 211, and the temperature of the gas immediately after being introduced from the evaporation tank 201 to the second pipe 212 also flow out of the evaporation tank 201. Since it is closely related to the concentration of IPA vapor in the gas, it can be used as a concentration control parameter.
[0103]
In this manner, at least one of various physical elements related to the processing gas can be acquired as a concentration control parameter, and the concentration of IPA vapor in the processing gas can be controlled based on the acquired concentration control parameter.
[0104]
On the other hand, as a control object for controlling the concentration of the IPA vapor in the processing gas, these pipes are adjusted by adjusting the gas flow rate in the first pipe 211 or the gas flow rate in the third pipe 213. The concentration can be adjusted by controlling the flow rate ratio.
[0105]
In the above description, the temperature of the gas in the first pipe 211 and the temperature of the liquid IPA in the evaporation tank 201 are the same temperature T.₀However, these temperatures may be set individually. At this time, it is conceivable that the IPA vapor in the gas flowing out of the evaporation tank 201 is not saturated, and the flow rate or the like cannot be obtained by simple calculation as described above, but the processing gas can be obtained by appropriately performing feedback control. The concentration of the IPA vapor inside can be maintained appropriately.
[0106]
Further, when changing the temperature of the gas in the first pipe 211 or the temperature of the liquid IPA in the evaporation tank 201, changing these temperatures changes the concentration of the IPA vapor in the gas flowing out of the evaporation tank 201. Thus, since the concentration of the IPA vapor in the processing gas can be changed, the temperature of the gas in the first pipe 211 and the temperature of the liquid IPA in the evaporation tank 201 can also be used as control targets.
[0107]
As described above, the concentration of the IPA vapor in the processing gas can be controlled by controlling at least one of various elements as a control target.
[0108]
Moreover, although the said embodiment demonstrated that the density | concentration of IPA vapor | steam was set by the operator, the density | concentration setting of IPA vapor | steam can also be performed automatically. That is, the temperature of the substrate 9 measured by the thermometer 154 (or a temperature corresponding to the temperature of the substrate 9) T_WThe gas supply control unit 172 obtains the saturation concentration of IPA at 322 with reference to the table 322, and the concentration below the obtained saturation concentration is C._DETMay be automatically determined.
[0109]
Further, the temperature T of the substrate 9 during the drying process_WIn response to changes in C_DETMay be changed automatically. In this substrate processing apparatus 100, the concentration C_DETIs controlled by feedback control, so that the temperature T of the substrate 9 during processing is_WWhen the concentration rises, the concentration C_DETIt is also possible to change.
[0110]
As described above, the substrate processing apparatus 100 can automatically perform concentration control for preventing the condensation of IPA on the surface of the substrate 9.
[0111]
As described above, the substrate processing apparatus 100 according to the first embodiment of the present invention has been described. In this substrate processing apparatus 100, after the pure water adhering to the substrate 9 is scattered at a high speed, the substrate 9 is scattered. The rotation speed is reduced (or stopped) to a low-speed rotation, and the processing gas is supplied to the substrate 9 at least during the low-speed rotation, so that the supply amount of the processing gas is reduced while preventing the generation of watermarks. It can be limited to only the amount required during rotation (or when stopped). As a result, it is possible to manufacture the substrate 9 with good quality while suppressing the manufacturing cost of the substrate 9.
[0112]
Further, since the concentration of the IPA vapor in the processing gas can be appropriately controlled, it is possible to prevent the IPA vapor from condensing on the surface of the substrate 9 and to perform an appropriate drying process.
[0113]
<2. Second Embodiment>
FIG. 8 is a longitudinal sectional view showing a mechanical configuration of a substrate processing apparatus 100a according to the second embodiment of the present invention. The configuration of the control system is almost the same as the configuration shown in FIG. 2, and the configurations of the gas supply unit 171 and the gas supply control unit 172 are also almost the same as the configurations shown in FIGS. 5 and 6, respectively.
[0114]
Compared with the substrate processing apparatus 100 according to the first embodiment, the substrate processing apparatus 100a is capable of supplying pure water and gas to the lower surface (back surface) of the substrate 9, The second embodiment is the same as the first embodiment except that the atmosphere blocking plate 151 can be rotated and the thermometer 154 measures the temperature in the cup 104. In the following description, these differences will be briefly described, and the same components as those in the first embodiment will be described using the same reference numerals.
[0115]
In the substrate processing apparatus 100a, in order to be able to supply pure water and processing gas to the lower surface of the substrate 9 as well as the structure of the atmosphere blocking plate 151 of the first embodiment, The end of the double structure tube is exposed at the center. The inner tube 161 a of the double structure tube is connected to the pure water supply unit 161, and the outer tube 171 a is connected to the gas supply unit 171.
[0116]
Further, in order to expose the double-structure tube from the holding table 121, a hollow motor is used as the motor 131, and the support table 133 that supports the motor 131, the motor 131, the rotating shaft 123, and the holding table 121 are sequentially penetrated. A double structure tube is arranged in the box. The double structure tube is supported by a bearing 1231 inside the rotary shaft 123, and the outer tube 171a is formed of a somewhat hard material so that it can be easily supported by the bearing 1231. Further, a labyrinth 1232 is formed in a gap between the double structure tube and the holding base 121 or the rotating shaft 123 to protect the bearing 1231 from the entering matter. Of course, the labyrinth 1232 may be a V-seal or packing.
[0117]
In this substrate processing apparatus 100a, the atmosphere blocking plate 151 can also rotate in the same direction as the substrate 9 rotates. Therefore, the configuration of the lower surface side and the upper surface side of the substrate 9 is the same. That is, the atmosphere shielding plate 151 is connected to the support shaft 152 via the hollow motor 131a on the rotating shaft 153, and the double-structure tube passes through the support shaft 152, the motor 131a, the rotating shaft 153, and the atmosphere shielding plate 151. It is arranged like that. The double structure tube is supported by a bearing 1511 inside the rotating shaft 153, and a labyrinth 1512 is provided in the gap between the atmosphere blocking plate 151 and the rotating shaft 153 and the double structure tube. The inner tube 161 a is connected to the pure water supply unit 161, and the outer tube 171 a is connected to the gas supply unit 171.
[0118]
In FIG. 8, the pure water supply unit 161 and the gas supply unit 171 are separately shown on the atmosphere blocking plate 151 side and the holding table 121 side, but the double structure tube on the atmosphere blocking plate 151 side and the holding table 121 side are shown. These double-structure tubes may be connected to the same pure water supply unit 161 or gas supply unit 171.
[0119]
The control system of the substrate processing apparatus 100a is substantially the same as the control system in the first embodiment shown in FIG. That is, the motor control unit 132 controls the motor 131 on the holding table 121 side and the motor 131a on the atmosphere blocking plate 151 side, and the pure water supply control unit 162 and the gas supply control unit 172 have the holding table 121 side and The pure water supply unit 161 and the gas supply unit 171 on the atmosphere blocking plate 151 side are controlled. A thermometer 154 is disposed below the turntable 121 and measures the temperature of the atmosphere in the cup 104. The temperature measured by the thermometer 154 is regarded as the temperature of the substrate 9 and is used in the gas supply controller 172 as in the first embodiment.
[0120]
Next, the operation of the substrate processing apparatus 100a will be described with reference to FIG. The operation of the substrate processing apparatus 100a may be the operation shown in FIGS. 3 and 4 as in the first embodiment, and the operation described below is only an example. 9 is common to the holding stand 121 and the atmosphere blocking plate 151, and the processing gas supply operation and the pure water supply operation are also common to the upper and lower surfaces of the substrate 9. Further, the reference numerals shown in FIG. 9 are the same as those in FIGS.
[0121]
As shown in FIG. 9, in the cleaning process indicated by reference numeral P <b> 1, the substrate 9 is rotated while supplying pure water to the upper and lower surfaces of the substrate 9, and the upper and lower surfaces of the substrate 9 are cleaned. When the cleaning process is completed (time TM1), the pure water supply operation is stopped and the substrate 9 is rotated at 1500 to 3000 rpm for 2 to 3 seconds. Thereby, the pure water adhering to the upper surface and the lower surface of the substrate 9 is scattered to the cup 104, and most of the pure water adhering to the substrate 9 is removed. At this time, the supply of the processing gas to the upper surface and the lower surface of the substrate 9 may be stopped as shown by the thick solid line in FIG. 9, and is performed at about 500 liters / minute as shown by the thick broken line. May be. The process from time TM1 to TM2 is substantially the same as the process shown in FIGS.
[0122]
Next, when the removal of most of the pure water by the high-speed rotation of the substrate 9 is completed (time TM2), the rotation of the substrate 9 is reduced to about 500 rpm, and then the rotation speed of the substrate 9 is gradually increased over 20 to 30 seconds. (Time TM2 to TM3). Further, the supply amount of the processing gas supplied to the upper and lower surfaces of the substrate 9 is gradually reduced from about 500 liters / minute to about 100 liters / minute as the rotational speed of the substrate 9 decreases.
[0123]
As described above, when the substrate 9 is rotating, it is necessary to supply the processing gas to the substrate 9 in order to prevent the inflow of air from the gap G between the atmosphere blocking plate 151 and the cup 104. This supply amount is required to be approximately proportional to the rotation speed of the substrate 9. Therefore, in this operation example, the supply amount of the processing gas is also reduced as the rotation speed of the substrate 9 is reduced.
[0124]
When the supply of the processing gas for 20 to 30 seconds is completed (time TM3), the drying process indicated by reference sign P2 is completed.
[0125]
Note that the IPA vapor concentration of the processing gas used in the present embodiment is also feedback controlled as in the first embodiment, and the IPA vapor concentration is predetermined even when the flow rate of the processing gas continuously changes. Concentration C_DETAdjusted to Thereby, the condensation of IPA on the surface of the substrate 9 is prevented.
[0126]
The configuration and operation of the substrate processing apparatus 100a according to the second embodiment have been described above. In the substrate processing apparatus 100a, pure water and processing gas are supplied not only to the upper surface of the substrate 9, but also to the lower surface. Therefore, the state of the lower surface of the substrate 9 can be kept clean. In particular, in the manufacture of high-density semiconductor devices in recent years, the state of the lower surface of the substrate 9 is required to be kept clean, and the substrate processing apparatus 100a is configured to meet such requirements. .
[0127]
Further, in the substrate processing apparatus 100a, the atmosphere blocking plate 151 is also rotated in accordance with the rotation of the substrate 9. Therefore, the turbulence of the airflow on the upper surface of the substrate 9 can be suppressed, and the inflow of air from the gap G can be more effectively suppressed. be able to.
[0128]
Further, as shown in FIG. 9, the supply amount of the processing gas is adjusted according to the rotation speed of the substrate 9, so that the supply of the processing gas without excess or deficiency with respect to the rotation of the substrate 9 is realized. .
[0129]
<3. Modification>
The substrate processing apparatus according to the present invention has been described above. However, the present invention is not limited to the above embodiment, and various modifications can be made.
[0130]
For example, the holding table 121 is configured to hold the substrate 9 by the pins 122, but may be in any form as long as the substrate 9 can be fixed on the holding table 121. It may be fixed. Further, the posture of the substrate 9 to be held is not limited to the horizontal posture.
[0131]
Further, the motors 131 and 131a are not limited to electric motors, and may take any form as long as they generate power for rotating the holding base 121.
[0132]
Further, the processing gas from the gas supply unit 171 is supplied from the atmosphere blocking plate 151 and the holding stand 121. However, as long as the processing gas can be supplied to the upper surface and the lower surface of the substrate 9, any method can be used. It may be a form. For example, a thin tube may be passed over the substrate 9 to eject gas to the upper surface of the substrate 9, or an opening is formed in the holding base 121 and gas is supplied to the lower surface of the substrate 9 through this opening. You may make it do.
[0133]
Further, in the above embodiment, a processing gas in which IPA vapor is mixed with nitrogen gas is used. However, nitrogen gas alone or a gas containing vapors of other organic solvents may be used. Another gas may be used and any gas suitable for drying may be used.
[0134]
In the above embodiment, the saturated concentration of the organic solvent vapor with respect to the temperature has been described with reference to the table 322. However, the table 322 may store the saturated vapor pressure with respect to the temperature. For example, when IPA is used as the organic solvent and the temperature of the substrate 9 is 20 ° C., the saturation concentration of IPA is 32.4 mmHg at 20 ° C. Therefore, 32.4 mmHg ÷ 760 mmHg = 4.26% , And are calculated. This allows the operator to, for example, 3% C, which is less than 4.26% concentration._DETTo prevent condensation of IPA vapor on the substrate surface.
[0135]
Also, the supply of pure water is not limited to the above embodiment, and various modifications can be made in the same manner as in the case of gas supply, and separately from the gas without using a double structure tube. Pure water may be supplied to the substrate 9. Further, the cleaning process using pure water is not performed in the substrate processing apparatus, but the cleaned substrate 9 may be carried into the substrate processing apparatus.
[0136]
Moreover, although the drying process of the board | substrate 9 after a pure water cleaning was demonstrated in the said embodiment, it is not limited to a pure water, The drying process after the washing | cleaning by cleaning liquids other than a pure water may be sufficient. Furthermore, it is not limited to the drying process after washing | cleaning, The drying process after another process may be sufficient.
[0137]
Further, in the above embodiment, the rotation speed of the substrate 9 in the drying process is decreased from approximately high speed to low speed rotation, but may be gradually decreased depending on the processing content. For example, in FIG. 9, the rotational speed may be continuously decreased from time TM1 to time TM3. Further, the rotation speed and the gas supply amount shown in the embodiment are merely examples, and are not limited to such values.
[0138]
Furthermore, in the above embodiment, the state of drying the semiconductor substrate has been described. However, the present invention is not limited to the drying of the semiconductor substrate. For example, the processing of a glass substrate for manufacturing a liquid crystal display or a photomask is performed. The apparatus which performs the drying process in a process may be sufficient.
[0139]
Further, in the above embodiment, the temperature of the atmosphere blocking plate 151 or the temperature of the atmosphere in the cup 104 is measured using the thermometer 154 and the measured temperature is regarded as the temperature of the substrate 9. An opening may be provided in the blocking plate 151 or the holding stand 121, and the temperature of the substrate 9 may be measured from the opening using a radiation thermometer. Furthermore, the temperature of pure water used for the cleaning process or the temperature of the atmosphere near the substrate processing apparatus may be used as a temperature corresponding to the temperature of the substrate 9 before the drying process. That is, the temperature measurement of the substrate 9 may be direct or indirect.
[0140]
In the above-described embodiment, the temperature of the substrate 9 is described as being normal temperature in the first stage of the drying process. However, the temperature of the substrate 9 is raised to normal temperature or higher using the gas discharged in the standby process. You may do it.
[0141]
Furthermore, in the above embodiment, the temperature of the substrate 9 (more precisely, the temperature corresponding to the temperature of the substrate 9) is measured, but it is guaranteed that the temperature of the substrate 9 is not more than a certain temperature. In this case, the IPA vapor is included in the processing gas at a vapor pressure equal to or lower than the saturated vapor pressure at this temperature, so that condensation of the IPA vapor on the surface of the substrate 9 can be prevented.
[0142]
【The invention's effect】
  Claim 1 to9In the described invention, after rotating the holding table to disperse the liquid adhering to the substrate, the rotation speed of the holding table is reduced and the gas is supplied to the substrate, thereby preventing air entrainment due to rotation of the substrate. Therefore, the amount of gas supplied can be reduced. Thereby, generation | occurrence | production of a watermark can be prevented, suppressing consumption of gas.
[0143]
  Claims3In the described invention, after the liquid adhering to the substrate is scattered, the rotation speed of the holding table is decreased from the first rotation speed to the second rotation speed. In the invention described in claim 4, the liquid adhering to the substrate is scattered. Then, the rotation of the holding table is stopped, so that the amount of gas to be supplied to the substrate is sufficient according to the rotation speed of the holding table.
[0144]
  Claims6In the described invention, the substrate can be quickly dried while preventing condensation of the organic solvent vapor.
[0145]
  Claims7In the described invention, the turbulence of the airflow generated between the substrate and the atmosphere blocking plate can be prevented to further suppress the entrainment of the atmosphere. In the invention described in the seventh aspect, the other main surface of the substrate is also dried. Processing can be performed.
[0146]
  And claims9In the described invention, since the flow rate of the supplied gas can be changed according to the rotation speed of the holding table, it is possible to further supply the gas without excess or deficiency.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a substrate processing apparatus according to a first embodiment of the present invention.
FIG. 2 is a block diagram showing a control system of the substrate processing apparatus shown in FIG.
FIG. 3 is a time chart showing an example of the operation of the substrate processing apparatus.
FIG. 4 is a time chart showing another example of the operation of the substrate processing apparatus.
FIG. 5 is a block diagram illustrating a configuration of a gas supply unit and the like.
FIG. 6 is a block diagram showing a configuration and the like of a gas supply control unit.
FIG. 7 is a table showing the relationship between the saturation concentration of IPA vapor and the temperature.
FIG. 8 is a longitudinal sectional view of a substrate processing apparatus according to a second embodiment of the present invention.
FIG. 9 is a time chart showing still another example of the operation of the substrate processing apparatus.
FIG. 10 is a longitudinal sectional view of a conventional substrate processing apparatus.
FIG. 11 is a diagram illustrating a principle of generation of a watermark.
[Explanation of symbols]
9 Board
100, 100a substrate processing apparatus
121 Holding stand
131, 131a motor
132 Motor controller
151 Atmosphere blocker
171 Gas supply unit
171a Outer tube
172 Gas supply control unit
241 to 244 heater

Claims (9)

A substrate processing apparatus for removing liquid adhered to a substrate,
A holding table for holding a substrate;
A rotation drive source for rotating a substrate held by rotating the holding table;
An atmosphere blocking plate disposed to face one main surface of the substrate held by the holding table;
Gas supply means for supplying gas toward the one main surface;
A rotation control means for controlling the rotation drive source so that the rotation speed of the holding table decreases after the holding table is rotated and the liquid adhering to the substrate is scattered;
A gas supply control means for controlling the gas supply means so as to supply the gas to the substrate after at least the holder is rotated to disperse the liquid adhering to the substrate;
Equipped with a,
While the rotation control unit continues to rotate the holding table at a reduced rotation speed, the gas supply control unit rotates the holding table while the liquid adhering to the substrate is scattered. the substrate processing apparatus according to claim that you feed the gas at the same flow rate as the gas to be supplied. A substrate processing apparatus for removing liquid adhered to a substrate,
A holding table for holding a substrate;
A rotation drive source for rotating a substrate held by rotating the holding table;
An atmosphere blocking plate disposed to face one main surface of the substrate held by the holding table;
Gas supply means for supplying gas toward the one main surface;
A rotation control means for controlling the rotation drive source so that the rotation speed of the holding table decreases after the holding table is rotated and the liquid adhering to the substrate is scattered;
Gas supply for controlling the gas supply means so as to stop the supply of gas at least during the step of rotating the holding table to disperse the liquid adhering to the substrate and thereafter starting the supply of the gas to the substrate Control means;
A substrate processing apparatus comprising: The substrate processing apparatus according to claim 1 or 2,
Said rotation control means, the substrate processing apparatus, characterized that you change the rotational speed of the holder from a first rotational speed to a relatively slow second rotational speed for scattering the liquid attached to the substrate. The substrate processing apparatus according to claim 1, wherein:
The substrate processing apparatus, wherein the rotation control means continuously decreases the rotation speed of the holding table. A substrate processing apparatus for removing liquid adhered to a substrate,
A holding table for holding a substrate;
A rotation drive source for rotating a substrate held by rotating the holding table;
An atmosphere blocking plate disposed to face one main surface of the substrate held by the holding table;
Gas supply means for supplying gas toward the one main surface;
Rotation control means for controlling the rotation drive source so as to stop the rotation of the holding table after the holding table is rotated and the liquid adhering to the substrate is scattered.
A gas supply control means for controlling the gas supply means so as to supply the gas to the substrate after at least the holder is rotated to disperse the liquid adhering to the substrate;
With
The substrate processing apparatus, wherein the gas supply control means supplies the gas to the substrate during a drying process performed after the rotation control means stops the rotation of the holding table . A substrate processing apparatus according to any one of claims 1 to 5,
A mixed gas of nitrogen gas and organic solvent vapor the gas is heated, the concentration of the organic solvent vapor, characterized by concentration der Rukoto below the concentration of saturated vapor pressure at the substrate at the same temperature Substrate processing equipment. A substrate processing apparatus according to any one of claims 1 to 6,
Means you want to rotate. The atmosphere blocker plate in accordance with the rotation of the holding table,
A substrate processing apparatus further comprising: A substrate processing apparatus according to any one of claims 1 to 7,
Means for supplying the gas toward the other main surface of the substrate held from the holding table;
Further comprising a substrate processing apparatus according to claim Rukoto a. A substrate processing apparatus according to any one of claims 1 to 8,
The substrate processing apparatus, wherein the gas supply control means changes a flow rate of the gas supplied to the substrate according to a rotation speed of the holding table.

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