JP4244674B2

JP4244674B2 - Processing apparatus and processing method

Info

Publication number: JP4244674B2
Application number: JP2003086504A
Authority: JP
Inventors: 河西　　繁; 誠之石橋; 薫山本; 澄田中; 健一柳谷
Original assignee: Tokyo Electron Ltd
Current assignee: Tokyo Electron Ltd
Priority date: 2002-11-08
Filing date: 2003-03-26
Publication date: 2009-03-25
Anticipated expiration: 2023-03-26
Also published as: KR20050074506A; WO2004042487A1; JP2004206662A; KR100928596B1; KR20060116248A; KR100715052B1

Description

【０００１】
【発明の属する技術分野】
本発明は、半導体ウエハ等に所定の処理を施すための処理装置及び処理方法に関する。
【０００２】
【従来の技術】
一般に、半導体集積回路を製造するには、半導体ウエハ等の被処理体に、成膜処理、エッチング処理、熱酸化処理、拡散処理、改質処理、結晶化処理等の各種の処理を繰り返し行って所望する集積回路を形成するようになっている。また、被処理体に対して処理を行うものではないが、処理容器内等に付着した不要な膜やパーティクルを除去する処理を行うためにエッチングガスを流して上記不要な膜等を取り除くクリーニング処理も適宜行われる。
【０００３】
ところで、１つの処理装置において、上記したような異種の処理や同種の処理でも処理条件を異ならせて複数種類の処理を行う場合がある。一般的に処理装置に設けられる排気系は、この処理装置が使用されることになる処理時の圧力範囲を考慮して設計されることになり、使用圧力範囲において排気コンダクタンスが最適となるように排気管の直径等が設定され、また、使用圧力範囲に適するように真空ポンプの種類も設定される。
そして、上述のように異種の処理、或いは同種の処理でも処理条件の異なる複数の処理を１つの処理装置で行うことを予定しているような場合において、処理圧力が比較的低い処理と処理圧力が比較的高い処理とが含まれる時には、各圧力領域において処理容器内の圧力を安定的に制御することが求められる。この場合、従来の処理装置では、処理容器内の圧力を検出し、この検出値に基づいて排気系の圧力調整弁を制御したり、或いは排気系に流量制御しつつバラストガスを導入することが行われていた（特許文献１参照）。
【０００４】
また、他の従来装置としては、排気系にバイパスラインを設けて、それを使用
圧力範囲に応じて切り替えて用いるようにした装置も知られている。この従来装置の一例を、図６に基づいて説明する。図６は従来の処理装置の一例を示す概略構成図である。
図示するように、この処理装置２は真空引き可能になされた例えばアルミニウム製の筒体状の処理容器４を有しており、この内部には例えば加熱ヒータ等の加熱手段６を備えた載置台８が設けられ、この載置台８上に半導体ウエハＷを載置させて固定できるようになっている。また、この処理容器４の天井部には、この処理容器４内へ各種の処理ガスを導入するガス導入手段として例えばシャワーヘッド部１０が設けられており、このシャワーヘッド部１０の下面に設けた多数のガス噴射孔１０Ａから下方に向けてガスを噴射するようになっている。
【０００５】
そして、このシャワーヘッド部１０には、Ａｒ、Ｈｅ、Ｎ₂ 等の不活性ガスを供給する不活性ガス供給系１２と、複数系統の、すなわち図示例では３系統の処理ガス供給系１４、１６、１８とがそれぞれ接続されている。例えば第１の処理ガス供給系１４では成膜時の処理ガスとしてＷＦ₆ ガスが供給され、第２の処理ガス供給系１６では成膜時の処理ガスとしてＨ₂ ガスが供給され、第３の処理ガス供給系１８ではクリーニング処理時の処理ガス（クリーニングガス）としてＣｌＦ₃ ガスが供給される。また、不活性ガス供給系１２の途中及び第１〜第３の各処理ガス供給系１４〜１８の途中には、流れるガス流量を制御するために例えばマスフローコントローラ等よりなる流量制御部１２Ａ、１４Ａ、１６Ａ、１８Ａがそれぞれ介設されている。また、各流量制御部１２Ａ〜１８Ａの上流側及び下流側には、開閉弁２２、２４、２６、２８がそれぞれ設定されており、必要に応じてこれらを開閉できるようになっている。
【０００６】
一方、上記処理容器４の底部には、排気口３０が設けられており、この排気口３０には、真空排気系３２が接続されている。この真空排気系３２は、内径が大きくなされて排気コンダクタンスが大きくなされた主排気管３４を有しており、この主排気管３４には、その上流側より下流側に向けてスロットルバルブのように弁開度が調整可能になされた第１の圧力制御弁３６と真空ポンプ３８とが順次介設されている。そして、上記第１の圧力制御弁３６の直前と直後とには、開閉弁４０がそれぞれ介設されている。
また、上記第１の圧力制御弁３６及びその直前と直後の各開閉弁４０を迂回するようにして、上記主排気管３４よりも内径が小さくなされて排気コンダクタンスが小さくなされたバイパス排気管４２が接続されている。そして、このバイパス排気管４２には、スロットルバルブのように弁開度が調整可能になされた第２の圧力制御弁４４が介設されると共に、この第２の圧力制御弁４４の直前及び直後にも開閉弁４６がそれぞれ介設されている。
【０００７】
そして、上記処理容器４には、この内部の圧力を検出するための圧力計４８が設けられ、この圧力計４８の検出値に基づいて、例えばマイクロコンピュータ等よりなる制御手段５４が上記各流量制御部１２Ａ〜１８Ａ、第１及び第２の圧力制御弁３６、４４、真空ポンプ３８及び各開閉弁２２〜２８、４０、４６の開閉動作を制御するようになっている。尚、この制御手段５４は、この処理装置２の全体の動作も制御し、これに予め組み込まれた複数の処理用プログラム（レシピとも称す）に基づいて制御動作が行われる。
例えば処理圧力が低い低圧処理として例えばタングステン膜の成膜処理を行う時には、ＷＦ₆ ガスとＨ₂ ガスのみをそれぞれ所定の値に流量制御しつつ流し（必要に応じて不活性ガスを流してもよい）、これと同時に、バイパス排気管４２はこの開閉弁４６を閉状態としてバイパス排気管４２にガスが流れないようにし、且つ主排気管３４はこの開閉弁４０を開状態としてこの第１の圧力制御弁３６の弁開度を調整することにより処理容器４内の圧力を一定に維持する。
【０００８】
これに対して、処理圧力が高い高圧処理として例えばクリーニング処理を行う時には、ＣｌＦ₃ のみを所定の値に流量制御しつつ流し（必要に応じて不活性ガスを流してもよい）、これと同時に、主排気管３４はこの開閉弁４０を閉状態として第１の圧力制御弁３６にガスが流れないようにし、且つバイパス排気管４２はこの開閉弁４６を開状態としてバイパス排気管４２にガスを流しつつ、この第２の圧力制御弁４４の弁開度を調整することにより処理容器４内の圧力を一定に維持する。
【０００９】
このように処理圧力が大きい場合と小さい場合とで、主排気管３４とバイパス排気管４２とを切り替えて使用することにより、使用圧力範囲の差が大きい複数種類の処理に対応するようになっている。尚、処理圧力が高い処理としては、上記クリーニング処理の他に酸化処理、拡散処理等がある。
また、本発明の関連技術として、複数の真空ポンプを設けた場合にその動作圧力範囲内の相異に対応するために、バイパス排気管を設けた処理装置として特許文献２に開示された技術も知られている。
【００１０】
【特許文献１】
特開平１０−１１１５２号公報（第２−４頁、図１−図５）
【特許文献２】
特開平８−２９００５０号公報（第４−５頁、図１）
【００１１】
【発明が解決しようとする課題】
ところで、先の特許文献１の従来装置例にあっては、排気系に流量制御したバラストガスを導入するようにしていることから、処理圧力を広い範囲で変更するような場合には、十分に対応できる構造ではなかった。また、無駄な不活性ガスを大量に使用するので装置の運転コストの高騰を招いている。
また、図６に示す従来装置にあっては、第２の圧力制御弁４４が介設されたバイパス排気管４２を設ける必要があることから、装置自体のコスト高を招来するのみならず、部品点類が多数になることからメンテナンス時も多くの時間を要し、メンテナンス性が劣る、という問題があった。
本発明は、以上のような問題点に着目し、これを有効に解決すべく創案されたものである。本発明の目的は、処理圧力の範囲が大きく異なる複数種類の処理を行う場合にも、バイパス管や複数の圧力制御弁を用いることなく、それぞれの処理の圧力制御を適正に行うことが可能な処理装置及び処理方法を提供することにある。
また本発明の他の目的は、複数の圧力制御弁を用いることなく、それぞれの処理の圧力制御を適正に行うことが可能な処理装置及び処理方法を提供することにある。
【００１２】
【課題を解決するための手段】
請求項１に係る発明は、処理圧力が異なる複数の処理を行なう処理装置において、内部に被処理体を載置する載置台を有する処理容器と、前記処理容器内へガスを導入するガス導入手段と、前記ガス導入手段へ接続されて、途中に流量制御部が介設されて複数の異なる処理ガスを供給する複数の処理ガス供給系と、前記ガス導入手段へ接続されて、途中に流量制御部が介設されて不活性ガスを供給する不活性ガス供給系と、前記処理容器に接続されて、途中に弁開度が設定可能になされた圧力制御弁と真空ポンプとが介設された真空排気系と、前記処理容器に設けた圧力計と、前記複数の処理の内、処理圧力が低い方の処理である成膜処理を行う時には前記複数の各処理ガス供給系の流量制御部にそれぞれ一定の流量を流す指令をしつつ前記圧力計の検出値に基づいて前記圧力制御弁の弁開度を制御して前記処理圧力が低い方の圧力を維持し、処理圧力が高い方の処理であるクリーニング処理を行う時には前記圧力制御弁の弁開度を所定の値に固定すると共に、前記圧力計の検出値に基づいて前記不活性ガス供給系の流量制御部により流量を制御して前記処理圧力が高い方の圧力を維持するように動作させる制御手段と、を備えたことを特徴とする処理装置である。
【００１３】
このように、処理圧力が異なる複数の処理の内、処理圧力が低い方の処理である成膜処理を行なう時には処理ガスの流量を一定に維持しつつ圧力制御弁の弁開度を調整するようにして処理容器内の圧力を制御し、処理圧力が高い方の処理であるクリーニング処理を行なう時には圧力制御弁の弁開度を所定の値に固定した状態で不活性ガスの流量を調整することにより処理容器内の圧力を制御するようにしたので、処理圧力の範囲が大きく異なる複数種類の処理を行う場合にも、バイパス管や複数の圧力制御弁を用いることなく、それぞれの処理の圧力制御を適正に行うことができる。また、クリーニング処理の処理時間が短くなってスループットを向上させることができる。
【００１４】
この場合、例えば請求項２に規定するように、前記真空排気系には第２の真空ポンプが介設されると共に、前記真空排気系の圧力制御弁と前記第２の真空ポンプとを迂回させて、途中に切り替え用開閉弁を介設したバイパス排気経路が設けられる。
【００１５】
請求項３に係る発明は、上記請求項１に係る装置発明を用いて行われる方法発明を規定したものであり、すなわち、内部に被処理体を載置する載置台を有する処理容器と、前記処理容器内へガスを導入するガス導入手段と、前記ガス導入手段へ接続されて、途中に流量制御部が介設されて複数の異なる処理ガスを供給する複数の処理ガス供給系と、前記ガス導入手段へ接続されて、途中に流量制御部が介設されて不活性ガスを供給する不活性ガス供給系と、前記処理容器に接続されて、途中に弁開度が設定可能になされた圧力制御弁と真空ポンプとが介設された真空排気系と、前記処理容器に設けた圧力計と、前記圧力計の検出値に基づいて前記各流量制御部を制御する制御手段と、を有する処理装置を用いて処理圧力が異なる複数の処理を行う方法において、前記複数の処理の内、処理圧力が低い方の処理である成膜処理を行う時には前記複数の各処理ガス供給系に流れる処理ガスの流量をそれぞれ一定に維持しつつ前記圧力計の検出値に基づいて前記圧力制御弁の弁開度を制御するようにして前記処理圧力が低い方の圧力を維持し、処理圧力が高い方の処理であるクリーニング処理を行う時には前記圧力制御弁の弁開度を所定の値に固定すると共に、前記圧力計の検出値に基づいて前記不活性ガス供給系に流れる不活性ガスの流量を制御して前記処理圧力が高い方の圧力を維持するようにしたことを特徴とする処理方法である。
【００１６】
この場合、例えば請求項４に規定するように、前記真空ポンプは、前記処理圧力が低い方の処理である成膜処理と前記処理圧力が高い方の処理であるクリーニング処理でその回転数を異なるように制御する。
また、例えば請求項５に規定するように、前記１つの真空排気系により、前記複数の処理の排気が行われる。
【００１７】
請求項６に係る発明は、内部に被処理体を載置する載置台を有する処理容器と、前記処理容器内へガスを導入するガス導入手段と、前記ガス導入手段へ接続されて、途中に流量制御部が介設されて複数の異なるガスを供給する複数のガス供給系と、前記処理容器に接続されて、途中に第１の真空ポンプと第２の真空ポンプと弁開度が任意に設定可能になされた圧力制御弁と開閉弁とが介設された真空排気系と、前記処理容器の圧力を検出する圧力計と、を備えて処理圧力が異なる複数の処理を行なう処理装置において、前記圧力制御弁と前記第２の真空ポンプと前記開閉弁とを迂回させてバイパス排気経路を設け、前記バイパス排気経路に、前記バイパス排気経路のバイパス排気管に介設された第１バイパス開閉弁と、該第１バイパス開閉弁を迂回するように設けた補助バイパス排気管と、該補助バイパス排気管に介設された第２バイパス開閉弁と、該補助バイパス排気管に介設されたオリフィス機構と、よりなって、前記処理容器内を大気圧より真空引きする際に真空引きの衝撃を和らげる機能を有するソフトスタート弁機構を介設し、前記複数の処理の内、処理圧力が低い方の処理である成膜処理を行う時には前記複数の各ガス供給系の流量制御部にそれぞれ一定の流量を流す指令をしつつ前記圧力計の検出値に基づいて前記圧力制御弁の弁開度を調整することにより前記処理容器内の圧力を制御し、処理圧力が高い方の処理であるクリーニング処理を行う時には前記開閉弁を閉じることによって前記圧力制御弁側への排気を停止すると共に、前記第１バイパス開閉弁を閉状態とし且つ前記第２バイパス開閉弁を開状態とすることにより前記ソフトスタート弁機構を低い排気コンダクタンス状態に維持して前記バイパス排気経路に排気ガスを流しつつ前記圧力計の検出値に基づいて前記流量制御部により流量を調整することにより前記処理容器内の圧力を制御する制御手段を設けるように構成したことを特徴とする処理装置である。
【００１８】
このように、真空排気系にバイパス排気経路を設けると共にこのバイパス排気経路にソフトスタート弁機構を介在させるようにし、処理圧力が異なる複数の処理を行なう際に、例えば処理圧力が低い方の処理である成膜処理を行う時には圧力制御弁の弁開度を調整するようにして処理容器内の圧力を制御し、処理圧力が高い方の処理であるクリーニング処理を行う時には上記圧力制御弁側への排気を停止し、上記ソフトスタート弁機構を低い排気コンダクタンス状態に維持してこのバイパス排気経路に排気ガスを流すようにして処理容器内の圧力を設定することができ、従って、高価で且つ構造が大きな圧力制御弁を複数設ける必要がなく、全体としての排気系の構造を小型で、且つ簡単化させることが可能となる。
【００１９】
また、処理圧力が高い方の処理であるクリーニング処理を行う時には、流量制御部によりガス流量を調整することにより処理容器内の圧力を制御することが可能となる。
【００２０】
請求項７に係る発明は、内部に被処理体を載置する載置台を有する処理容器と、前記処理容器内へガスを導入するガス導入手段と、前記ガス導入手段へ接続されて、途中に流量制御部が介設されて複数の異なるガスを供給する複数のガス供給系と、前記処理容器に接続されて、途中に第１の真空ポンプと第２の真空ポンプと弁開度が任意に設定可能になされた圧力制御弁と開閉弁とが介設された真空排気系と、前記処理容器の圧力を検出する圧力計と、を備えて処理圧力が異なる複数の処理を行なう処理装置において、前記圧力制御弁と前記第２の真空ポンプと前記開閉弁とを迂回させてバイパス排気経路を設け、前記バイパス排気経路に、前記処理容器内を大気圧より真空引きする際に真空引きの衝撃を和らげる機能を有するソフトスタートバルブを介設し、前記複数の処理の内、処理圧力が低い方の処理である成膜処理を行う時には前記複数の各ガス供給系の流量制御部にそれぞれ一定の流量を流す指令をしつつ前記圧力計の検出値に基づいて前記圧力制御弁の弁開度を調整することにより前記処理容器内の圧力を制御し、処理圧力が高い方の処理であるクリーニング処理を行う時には前記開閉弁を閉じることによって前記圧力制御弁側への排気を停止すると共に、前記ソフトスタートバルブを低い排気コンダクタンス状態に維持して前記バイパス排気経路に排気ガスを流しつつ前記圧力計の検出値に基づいて前記流量制御部により流量を調整することにより前記処理容器内の圧力を制御する制御手段を設けるように構成したことを特徴とする処理装置である。
【００２１】
請求項８に係る発明は、内部に被処理体を載置する載置台を有する処理容器と、前記処理容器内へガスを導入するガス導入手段と、前記ガス導入手段へ接続されて、途中に流量制御部が介設されて複数の異なるガスを供給する複数のガス供給系と、前記処理容器に接続されて、途中に第１の真空ポンプと第２の真空ポンプと弁開度が任意に設定可能になされた圧力制御弁と開閉弁とが介設された真空排気系と、前記処理容器の圧力を検出する圧力計と、を有する処理装置を用いて処理圧力が異なる複数の処理を行う処理方法において、前記圧力制御弁と前記第２の真空ポンプと前記開閉弁とを迂回させてバイパス排気経路を設け、前記バイパス排気経路に、前記バイパス排気経路のバイパス排気管に介設された第１バイパス開閉弁と、該第１バイパス開閉弁を迂回するように設けた補助バイパス排気管と、該補助バイパス排気管に介設された第２バイパス開閉弁と、該補助バイパス排気管に介設されたオリフィス機構と、よりなって、前記処理容器内を大気圧より真空引きする際に真空引きの衝撃を和らげる機能を有するソフトスタート弁機構を介設し、前記複数の処理の内、処理圧力が低い方の処理である成膜処理を行う時には前記複数の各ガス供給系の流量制御部にそれぞれ一定の流量を流す指令をしつつ前記圧力計の検出値に基づいて前記圧力制御弁の弁開度を調整することにより前記処理容器内の圧力を制御し、処理圧力が高い方の処理であるクリーニング処理を行う時には前記開閉弁を閉じることによって前記圧力制御弁側への排気を停止すると共に、前記第１バイパス開閉弁を閉状態とし且つ前記第２バイパス開閉弁を開状態とすることにより前記ソフトスタート弁機構を低い排気コンダクタンス状態に維持して前記バイパス排気経路に排気ガスを流しつつ前記圧力計の検出値に基づいて前記流量制御部により流量を調整することにより前記処理容器内の圧力を制御するようにしたことを特徴とする処理方法である。
【００２２】
【発明の実施の形態】
以下に、本発明に係る処理装置及び処理方法の一実施例を添付図面に基づいて詳述する。
＜第１実施例＞
図１は本発明に係る処理装置の第１実施例を示す概略構成図、図２は第１の処理方法の工程を示すフローチャート、図３は第２の処理方法の工程を示すフローチャートである。図６において説明した部分と同一構成部分については同一符号を付してその説明を行う。尚、以下で説明する”処理ガスの分圧が比較的重要となる処理”とは一般的には処理圧力が低い処理（低圧処理）を指し、”処理ガスの分圧が比較的重要とならない処理”とは一般的には処理圧力が高い処理（高圧処理）を指すものとする。
【００２３】
図示するように、この処理装置５２は真空引き可能になされた例えばアルミニウム製の筒体状の処理容器４を有しており、この内部には例えば加熱ヒータ等の加熱手段６を備えた載置台８が設けられ、この載置台８上に半導体ウエハＷを載置させて固定できるようになっている。また、この処理容器４の天井部には、この処理容器４内へ各種の処理ガスを導入するガス導入手段として例えばシャワーヘッド部１０が設けられており、このシャワーヘッド部１０の下面に設けた多数のガス噴射孔１０Ａから下方に向けてガスを噴射するようになっている。
【００２４】
そして、このシャワーヘッド部１０には、Ａｒ、Ｈｅ、Ｎ₂ 等の不活性ガスを供給する不活性ガス供給系１２と、複数系統の、すなわち図示例では３系統の処理ガス供給系１４、１６、１８とがそれぞれ接続されている。例えば第１の処理ガス供給系１４では成膜時の処理ガスとしてＷＦ₆ ガスが供給され、第２の処理ガス供給系１６では成膜時の処理ガスとしてＨ₂ ガスが供給され、第３の処理ガス供給系１８ではクリーニング処理時の処理ガス（クリーニングガス）としてＣｌＦ₃ ガスが供給される。尚、ここではタングステン膜の成膜時にＷＦ₆ ガスとＨ₂ ガスとが同時に供給され、また、この成膜時に不活性ガスも必要に応じて供給される。
【００２５】
また、不活性ガス供給系１２の途中及び第１〜第３の各処理ガス供給系１４〜１８の途中には、流れるガス流量を制御するために例えばマスフローコントローラ等よりなる流量制御部１２Ａ、１４Ａ、１６Ａ、１８Ａがそれぞれ介設されている。また、各流量制御部１２Ａ〜１８Ａの上流側及び下流側には、開閉弁２２、２４、２６、２８がそれぞれ設置されており、必要に応じてこれらを開閉できるようになっている。
【００２６】
一方、上記処理容器４の底部には、排気口３０が設けられており、この排気口３０には、真空排気系３２が接続されている。この真空排気系３２は、内径が大きくなされて排気コンダクタンスが大きくなされた排気管３４を有している。この排気管３４の内径は、例えば１００〜１５０ｍｍ程度である。この排気管３４には、その上流側より下流側に向けてスロットルバルブのように弁開度が調整可能になされた圧力制御弁３６と、例えばドライポンプよりなる第１の真空ポンプ３８とが順次介設されている。そして、上記圧力制御弁３６の直前と直後とには、開閉弁４０がそれぞれ介設されている。ここで、この真空排気系３２は、処理ガスの分圧を精度良く制御しなければならない処理、すなわちここではタングステン膜の成膜処理時に必要とされる最適な排気コンダクタンスを実現できるように配管の内径や、圧力制御弁３６及び真空ポンプ３８の能力が設定されている。尚、この実施例にあっては、従来装置で用いたバイパス排気管４２及び第２の圧力制御弁４４は設けていない（図６参照）。
【００２７】
そして、上記処理容器４には、この内部の圧力を検出するための圧力計４８が設けられ、この圧力計４８の検出値に基づいて、例えばマイクロコンピュータ等よりなる制御手段５４が上記各流量制御部１２Ａ〜１８Ａ、圧力制御弁３６、真空ポンプ３８及び各開閉弁２２〜２８、４０の開閉動作を制御するようになっている。尚、この制御手段５４は、この処理装置５２の全体の動作も制御し、これに予め組み込まれた複数の処理用プログラム（レシピ）に基づいて制御動作が行われる。
【００２８】
後述するように、処理ガスの分圧が重要となる処理、例えば処理圧力が低い低圧処理としてタングステン膜の成膜処理等を行う時には、ＷＦ₆ ガスとＨ₂ ガスのみをそれぞれ所定の値に流量制御しつつ流し（必要に応じて不活性ガスを流してもよい）、これと同時に、圧力制御弁３６の弁開度を調整することにより処理容器４内の圧力を一定に維持する。この圧力制御弁３６は、圧力制御弁３６の動作特性において最も精度良く動作する範囲内にあるような圧力制御弁が選択される。
これに対して、処理ガスの分圧が比較的重要とならないような処理、例えば処理圧力が高い高圧処理として例えばクリーニング処理等を行う時には、ＣｌＦ₃ を所定の値に流量制御しつつ流すと同時に不活性ガスも流し、これと同時に圧力制御弁３６の弁開度を所定の弁開度に維持した状態で不活性ガスの流量を調整することにより処理容器４内の圧力を略一定に維持する。尚、処理圧力が高い高圧処理としては例えば酸化処理や拡散処理等も含まれる。
【００２９】
次に、以上のように構成された処理装置を用いて行われる処理方法について説明する。
この処理装置５２では、処理ガスの分圧が重要となる処理、例えばタングステン膜の成膜処理や処理ガスの分圧が比較的重要とならない処理、例えばクリーニング処理等が種々行われるが、それぞれの場合について説明する。尚、ここで”処理”とは処理容器４内に半導体ウエハＷが存在する場合のみならず、存在しない場合に行われるクリーニング処理のような処理も含まれるものとする。
【００３０】
＜処理ガスの分圧が重要となる処理：タングステン膜の成膜処理＞
まず、処理ガスの分圧が重要となる処理の場合について説明する。
ここで、処理ガスの分圧が重要となる処理とは、例えばＷＦ₆ ガスとＨ₂ ガスとを用いてタングステン膜を堆積するような成膜処理であり、電気的特性が良好なタングステン膜を適正な成膜レートで、しかもウエハ面内における膜厚の面内均一性を高く維持した状態で堆積させるには、上記両ガスの各流量、流量比、処理圧力、処理温度等を精度良く維持しなければならない。このような処理は、例えば図２に示すフローチャートのようにして行う。
【００３１】
まず、処理容器４の載置台８上に未処理の半導体ウエハＷを載置したならば、真空排気系３２の真空ポンプ３８を駆動してこの処理容器４内を真空引きし、そして真空ポンプ３８を成膜処理用に所定の回転数に維持する（Ｓ１）。尚、この回転数はクリーニング処理時とは異なる場合がある。これと同時にウエハＷを加熱してこれを所定の温度に設定する（Ｓ２）。そして、成膜処理を開始すべくＷＦ₆ ガス及びＨ₂ ガスをそれぞれ所定の流量に設定して流し、タングステン膜を堆積させる（Ｓ３）。そして、この成膜処理中においては圧力計４８により処理容器４内の圧力が常時検出されており（Ｓ４）、この圧力検出値は制御手段５４において予め設定された設定値と比較され、検出値が設定値と同じになるように排気管３４に介設された圧力制御弁３６の弁開度が適宜調整される（Ｓ５のＮＯ、Ｓ６）。上記成膜処理は所定の時間行われ（Ｓ５のＹＥＳ、Ｓ７のＮＯ）、この成膜処理を所定の時間行ったならば（Ｓ７のＹＥＳ）、処理を終了することになる。上記成膜処理時間は、上記圧力制御弁３６の調整時間（数ｓｅｃ程度）よりもかなり長く、成膜処理時の膜厚への影響がほとんど生ずることはない。
【００３２】
＜処理ガスの分圧が比較的重要とならない処理：クリーニング処理＞
次に、処理ガスの分圧が比較的重要とならない処理の場合について説明する。
ここで処理ガスの分圧が比較的重要とならない処理とは、例えばクリーニングガスを用いて処理容器内の余分な付着膜等を除去するようなクリーニング処理であり、所定のエッチングレートを保証するためには、クリーニングガスの流量及び処理圧力をそれぞれ予め定められた設定値に維持する必要がある。尚、この時の処理圧力は、先の成膜処理時の処理圧力よりもかなり高い設定値となる。このような処理は、例えば図３に示すフローチャートのようにして行う。
【００３３】
まず、処理容器４内からウエハＷを取り出して処理容器４内を密閉状態にし、真空ポンプ３８を予め定められたクリーニング用の所定の回転数に設定し、維持する（Ｓ１１）。次に、例えばＡｒガス等の不活性ガスを流し、またこれと同時に処理ガスとしてクリーニングガス、例えばＣｌＦ₃ ガスを所定の流量に設定した状態で流し、クリーニング処理を開始する（Ｓ１２）。これと同時に、圧力制御弁３６を予め定められた所定の弁開度に設定し、この状態を継続的に維持する（Ｓ１３）。この弁開度は、クリーニング処理時の真空排気系３２の排気コンダクタンスが最適になるように予め実験的に求められている。
【００３４】
そして、このクリーニング処理中においては圧力計４８により処理容器４内の圧力が常時検出されており（Ｓ１４）、この圧力検出値は制御手段５４において予め設定された設定値と比較され、検出値が設定値と同じになるように不活性ガス供給系１２に介設された流量制御部１２Ａが適宜調整される（Ｓ１５のＮＯ、Ｓ１６）。尚、この間においてはＣｌＦ₃ ガスの流量は常時一定値を保たれることになる。上記クリーニング処理は所定の時間行われ（Ｓ１５のＹＥＳ、Ｓ１７のＮＯ）、このクリーニング処理を所定の時間行ったならば（Ｓ１７のＹＥＳ）、処理を終了することになる。
【００３５】
以上のように、タングステン膜の成膜処理や処理容器４内の不要な付着物を除去するクリーニング処理のように、処理圧力の範囲が大きく異なる複数種類の処理を行う場合にも、バイパス管や複数の圧力制御弁を用いることなく、それぞれの処理の圧力制御を適正に行うことができる。
また、用いる部品点数も少なくなることから、その分、メンテナンスも迅速に行うことができるので、メンテナンス性を向上させることができる。
更には、この場合、一般に圧力制御弁３６の応答動作よりも流量制御部１２Ａの応答動作の方がかなり早いので、流量制御部１２Ａによる圧力制御の方がより早く処理圧力に到達させることができ、従って、全ての処理において圧力制御弁で圧力を制御していた従来装置とは異なり、一部の処理において応答動作の早い流量制御部を使用して圧力制御した分、処理時間が短くなってスループットを向上させることが可能となる。
【００３６】
次に、以上に説明した各処理とは異なり、複数種類の処理ガスを用いる場合であって、ある所定の分圧の範囲内ならば、処理結果の品質を落とすことなく当該処理を実行できるような場合、このような処理を行う時には圧力制御弁３６の弁開度を大きく、例えば１００％に設定した状態にしておき、そして、上記各処理ガスの流量比を一定状態に維持しつつ各処理ガスの流量を調整して、処理容器４内の圧力を制御するようにして、流量調整のみで所定の処理を行なうようにしてもよい。
このような処理の具体例は、例えばＰＶＤ（ＰｈｙｓｉｃａｌＶａｐａｒＤｅｐｏｓｉｔｉｏｎ）処理やプリクリーン装置によるプリクリーン処理等が挙げられる。
この場合には、圧力制御弁３６の弁開度を調整することなく、応答速度の速い流量制御部のみの制御動作で処理圧力を制御することができるので、その分、制御性を向上させてスループットを高めることができる。
【００３７】
＜第２実施例＞
上記各実施例にあっては、図１に示したような一本の排気管３４を設け、これに１つの真空ポンプ３８を介設した場合を例にとって説明したが、１台の真空ポンプ３８だけでは排気能力が不足している場合には、図４に示す第２実施例のように構成してもよい。すなわち、この場合には、前記圧力制御弁３６に直列に、例えばターボ分子ポンプよりなる第２の真空ポンプ６０を介設し、そして、この圧力制御弁３６と上記第２の真空ポンプ６０とを迂回させるようにバイパス排気経路６２を排気管３４に接続する。そして、このバイパス排気経路６２の途中に切り替え用開閉弁６４を介設する。尚、このバイパス排気経路６２の内径は２５〜４０ｍｍ程度である。
【００３８】
この実施例では、処理容器４内を真空引きする場合、まず、排気管３４の開閉弁４０を閉じ、これに替えてバイパス排気管６２の切り替え用開閉弁６４を開状態にしてバイパス排気管６２を連通し、そして真空ポンプ３８を回転駆動することにより処理容器４内を荒引きする。ある程度荒引きした後に、処理容器４内の圧力が所定の真空度まで低下したならば、排気管３４の開閉弁４０を開状態にして第２の真空ポンプ６０も回転駆動させる。そして、バイパス排気管６２の切り替え用開閉弁６４を閉状態にする。これにより、先の真空ポンプ３８と第２の真空ポンプ６０の２台の真空ポンプで真空引きを継続する。また処理圧力が比較的高い処理を行う場合、例えばクリーニング処理を行う場合には、排気管３４の開閉弁４０を閉じてパイパス排気管６２のみを用いて真空引きしつつクリーニング処理を行ってもよい。この実施例においても、処理圧力の範囲が大きく異なる複数の処理を行う場合には、先に図１乃至図３を参照して説明したと同様に行えばよい。
【００３９】
＜第３実施例＞
次に本発明の第３実施例について説明する。
図５は本発明の処理装置の第３実施例を示す概略構成図である。図１、４及び図６において説明した部分と同一構成部分については同一符号を付してその説明を省略する。尚、ここで説明する処理圧力が比較的低い処理とは、先に説明した処理ガスの分圧が重要となる処理のことを意味し、処理圧力が比較的高い処理とは、処理ガスの分圧が重要とならない処理のことを意味する。
図５に示すように、ここでは主排気管３４には、その上流側から下流側に向けて、圧力制御弁３６、例えばターボ分子ポンプよりなる第２の真空ポンプ６０及び例えばドライポンプよりなる第１の真空ポンプ３８が順次介設され、そして、圧力制御弁３６の直ぐ上流側及び第２の真空ポンプ６０の直ぐ下流側には、それぞれ開閉弁４０が介設されている。
【００４０】
そして、上記圧力制御弁３６、第２の真空ポンプ６０及び両開閉弁４０を迂回するようにしてバイパス排気管となるバイパス排気経路６２を上記主排気管３４に接続している。前述したように、この主排気管３４の内径は例えば１００〜１５０ｍｍ程度で大口径であり、バイパス排気経路６２の内径は２５〜４０ｍｍ程度で小口径である。
そして、このバイパス排気経路６２の途中に、処理容器４内を大気圧より真空引きする際に真空引きの衝撃を和らげる機能を有するソフトスタート弁機構７０を介設している。これにより、制御手段５４は、処理圧力が比較的低い処理（例えば成膜処理等）を行う時には処理容器４に設けた圧力計４８の検出値に基づいて上記圧力制御弁３８の弁開度を調整することにより上記処理容器４内の圧力を制御し、処理圧力が比較的高い処理（例えばクリーニング処理、酸化処理、拡散処理等）を行う時には上記圧力制御弁３６への排気を停止すると共に上記ソフトスタート弁機構７０を低い排気コンダクタンス状態に維持して上記バイパス排気経路６２に排気ガスを流すように制御する。
【００４１】
具体的には、上記ソフトスタート弁機構７０は、上記バイパス排気経路６２に介設した第１バイパス開閉弁７２と、この第１バイパス開閉弁７２を迂回するようにして上記バイパス排気経路６２に接続した内径の小さな補助バイパス排気管７４と、この補助バイパス排気管７４に順次介設したオリフィス機構７６及び第２バイパス開閉弁７８とよりなる。
ここで周知のように、オリフィス機構７６は流路面積を狭めるためのオリフィス（図示せず）を有しており、上記第１バイパス開閉弁７２を閉状態とし、且つ第２バイパス開閉弁７８を開状態とすることにより、このソフトスタート弁機構７０の全体を低い排気コンダクタンス状態とすることができる。ここで、このバイパス排気経路６２や補助バイパス排気管７４の各内径や、上記オリフィス機構７６のオリフィス孔の流路面積は、比較的高い処理圧力の処理を行う場合において必要な流量の処理ガスを流した時に必要な処理圧力が略得られるような大きさにそれぞれ予め設定されて、その排気コンダクタンスが固定されている。
換言すれば、処理圧力が比較的高い処理では、プロセス圧力を精度良く制御する必要性が無い場合が多いので、このような場合には処理器４内の圧力制御は予め定めた固定的な排気コンダクタンスにより行うこととし、能動的には弁開度の調整等の操作は特段には行わないように構成されている。
【００４２】
次に、以上のように構成された実施例の動作について説明する。
＜大気圧から真空引きする場合＞
処理容器４内が大気圧状態になっており、この状態から処理容器４内の真空引きする場合には、まず、主排気管３４の両開閉弁４０を閉状態としてある程度の真空度に達した後でなければ使用できないターボ分子ポンプよりなる第２の真空ポンプ６０を隔離する。これと同時にソフトスタート弁機構７０においては、バイパス排気経路６２に介設した第１バイパス開閉弁７２を閉状態とし、補助バイパス排気管７４に介設した第２バイパス開閉弁７８を開状態とすることにより、このソフトスタート弁機構７０を低い排気コンダクタンス状態にする。このような状態で、第１の真空ポンプ３８を駆動して真空引きを開始する。この場合、処理容器４内の雰囲気は、補助バイパス排気管７４に介設したオリフィス機構７６のオリフィス孔を介してしか排気されないので、上述のように排気コンダクタンスはかなり低い状態になっている。この結果、処理容器４内に発生する真空引きの衝撃は和らげられて非常に少ないものとなり、処理容器４内の構造物やパーティクルが瞬間的に浮上等することを防止でき、また、処理容器４の内壁面や内部構造物の表面に付着していた不要な膜が剥がれ落ちることがなく、パーティクルの発生を防止することができる。
【００４３】
そして、真空引きの結果、ある程度の真空度（例えば１３３０Ｐａ）程度に達したならば、第１バイパス開閉弁７２を開状態に切り替えてこのバイパス排気経路６２の全体で真空引きを行う。この時には、第２バイパス開閉弁７８は開閉のどちらの状態にしてもよい。
そして更に真空引きを行って所定の真空度、すなわちターボ分子ポンプの上限圧力値である例えば１３３Ｐａ程度に達したならば、主排気管３４に介設した両開閉弁４０を開状態に切り替えて、これと同時に第２の真空ポンプ６０の駆動を開始する。この際、第１の圧力制御弁３６は全開状態にしておく。尚、これと同時に上記第１及び第２バイパス開閉弁７２、７８は共に閉状態に切り替える。このようにして処理容器４内を低い圧力雰囲気まで真空引きすることができる。
【００４４】
＜処理圧力が低い処理：例えば成膜処理＞
次に、処理圧力が低い処理を行う時の処理容器４内の圧力制御は、第１実施例で説明した処理ガスの分圧が重要となる処理の場合と略同じである。
すなわち、ソフトスタート弁機構７０の第１及び第２バイパス開閉弁７２、７８は共に閉状態に維持すると共に、主排気管３４の両開閉弁４０を開状態に維持し、圧力計４８の検出値に応じて圧力制御弁３６の弁開度を調整して処理容器４内の圧力を制御する。この際、各ガスの流量は、レシピに定められたようにそれぞれ一定値が維持されることになる。このような処理圧力が低い処理のプロセス圧力は、例えば数１０Ｐａ〜数１００Ｐａ程度の圧力である。
【００４５】
＜処理圧力が高い処理：例えばクリーニング処理や酸化処理＞
次に、処理圧力が高い処理を行う時の処理容器４内の圧力制御について説明する。
この場合には、大気圧の処理容器４内から真空引きを開始するような場合と同様に低い排気コンダクタンス状態とする。すなわち前述した成膜処理時とは逆に、主排気管３４に介設した両開閉弁４０を共に閉状態に維持して第１の真空ポンプ６０を隔離する。そして、ソフトスタート弁機構７０に関しては、第１バイパス開閉弁７２を閉状態に維持すると共に、逆に第２バイパス開閉弁７８は開状態を維持し、オリフィス機構７６を介してこの補助バイパス排気管７４を介してのみ排気ガスが真空引きされるようにする。この時のソフトスタート弁機構７０の排気コンダクタンスは、例えば全閉状態にしても僅かな隙間が生じている圧力制御弁３６の排気コンダクタンスと同程度である。
【００４６】
これにより、処理容器４内のプロセス圧力を高くした状態で処理を行うことができる。このように処理圧力が高い処理のプロセス圧力は、例えば数１０００Ｐａ〜２００００Ｐａ程度の圧力である。
上記処理圧力が高い処理では、処理容器４内の圧力を能動的には制御することはできなかったが、これに限定されず、例えばこの時の処理容器４内の圧力を圧力計４８で検出し、この検出値が所定の圧力を維持するように、制御手段５４を介して流量制御器を調整制御してガス流量、例えば不活性ガスやクリーニングガスの流量、或いは酸化処理を行っている場合には酸化ガスの流量を制御するようにしてもよい。
【００４７】
これによれば、処理圧力が高い処理の場合でもプロセス圧力を精度良く制御することが可能となる。
また上記ソフトスタート弁機構７０にあっては、補助バイパス排気管７４、第１及び第２バイパス開閉弁７２、７８及びオリフィス機構７６により構成した場合を例にとって説明したが、このソフトスタート弁機構７０として、上記バイパス排気経路６２内を完全に遮断状態に設定できる機能、このバイパス排気経路６２を低い排気コンダクタンス状態に設定できる機能及びこのバイパス排気経路６２内を上記低い排気コンダクタンスよりもある程度高い中程度の排気コンダクタンス状態に設定できる機能の３つの上記各機能を併せ持つ例えばＳＭＣ社製のソフトスタートバルブ（登録商標）を用いるようにしてもよい。
尚、上記各実施例では、タングステン膜を成膜処理する場合を例にとって説明したが、他の膜種を成膜する場合にも本発明を適用できる。
【００４８】
また、処理ガスの分圧が重要となる処理としては、成膜処理に限定されず、他の処理の場合にも適用できる。同様に、処理ガスの分圧が比較的重要とならない処理としては、クリーニング処理に限定されず、他の処理の場合、例えば前述したように酸化処理や拡散処理等を行う場合にも適用することができる。
また、各ガスの供給形態は、単に一例を示したに過ぎず、処理ガスの種類が増減すれば、それに対応してガス供給系の数も増減し、更に、シャワーヘッド部１０の構成も、処理ガスを処理容器４内に噴射する前に予め混合させるプレミックス型式、或いはシャワーヘッド部１０から噴射した後に混合させるポストミックス型式のどちらでも本発明を適用できる。また、シャワーヘッド部１０を用いないガス導入手段でも本発明を適用することができる。
【００４９】
また、ここでは枚葉式の処理装置を例にとって説明したが、一度に複数枚の被処理体の処理を行うことができるバッチ式の処理装置にも本発明を適用することができる。
また、主にマスフローコントローラによる制御は、所定の分圧の範囲内で行われるＰＶＤの処理で用いられることが多く、圧力制御弁はＣＶＤの処理で用いられることが多いことから、同じ装置でＰＶＤ及びＣＶＤの両方の処理をする場合に応用することができる。
更には、上記実施例においては、被処理体として半導体ウエハを例にとって説明したが、これに限定されず、ガラス基板、ＬＣＤ基板等にも適用し得るのは勿論である。
また、上記実施例では圧力制御の際、温度制御部又は圧力制御弁のどちらか一方を一定にしていたが、温度制御部と圧力制御弁を一定とせず常に両方の動作で圧力制御を行なうようにしてもよい。
【００５０】
【発明の効果】
以上説明したように、本発明の処理装置及び処理方法によれば、次のように優れた作用効果を発揮することができる。
請求項１〜５に係る発明によれば、処理圧力の範囲が大きく異なる複数種類の処理、すなわち成膜処理とクリーニング処理を行う場合にも、バイパス管や複数の圧力制御弁を用いることなく、それぞれの処理の圧力制御を適正に行うことができる。また、クリーニング処理の処理時間が短くなってスループットを向上させることができる。
また、真空排気系を１つにできるので用いる部品点数も少なくなることから、その分、メンテナンスも迅速に行うことができるので、メンテナンス性を向上させることができる。また、使用する不活性ガスの量も減少させることができる。
請求項６〜８に係る発明によれば、真空排気系にバイパス排気経路を設けると共にこのバイパス排気経路にソフトスタート弁機構を介在させるようにし、例えば処理圧力が低い方の処理である成膜処理を行う時には圧力制御弁の弁開度を調整するようにして処理容器内の圧力を制御し、処理圧力が高い方の処理であるクリーニング処理を行う時には上記圧力制御弁側への排気を停止し、上記ソフトスタート弁機構を低い排気コンダクタンス状態に維持してこのバイパス排気経路に排気ガスを流すようにして処理容器内の圧力を設定することができ、従って、高価で且つ構造が大きな圧力制御弁を複数設ける必要がなく、全体としての排気系の構造を小型で、且つ簡単化させることができる。よって、コスト的にも有効である。また、処理圧力が高い方の処理であるクリーニング処理を行う時には、流量制御部によりガス流量を調整することにより処理容器内の圧力を制御することができる。
【図面の簡単な説明】
【図１】本発明に係る処理装置の第１実施例を示す概略構成図である。
【図２】第１の処理方法の工程を示すフローチャートである。
【図３】第２の処理方法の工程を示すフローチャートである。
【図４】本発明の処理装置の第２実施例を示す概略構成図である。
【図５】本発明の処理装置の第３実施例を示す概略構成図である。
【図６】従来の処理装置の一例を示す概略構成図である。
【符号の説明】
４処理容器
８載置台
１０シャワーヘッド部（ガス導入手段）
１２不活性ガス供給系
１４，１６，１８処理ガス供給系
１２Ａ，１４Ａ，１６Ａ，１８Ａ流量制御部
３２真空排気系
３４主排気管（排気管）
３６第１の圧力制御弁（圧力制御弁）
３８真空ポンプ
４８圧力計
５２処理装置
５４制御手段
６０第２の真空ポンプ
６２バイパス排気経路
６４切り替え用開閉弁
７０ソフトスタート弁機構
７２第１バイパス開閉弁
７４補助バイパス排気管
７６オリフィス機構
７８第２バイパス開閉弁
Ｗ半導体ウエハ（被処理体）[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a processing apparatus and a processing method for performing predetermined processing on a semiconductor wafer or the like.
[0002]
[Prior art]
In general, in order to manufacture a semiconductor integrated circuit, various processes such as a film forming process, an etching process, a thermal oxidation process, a diffusion process, a modification process, and a crystallization process are repeatedly performed on an object to be processed such as a semiconductor wafer. A desired integrated circuit is formed. In addition, it does not process the object to be processed, but a cleaning process is performed to remove the unnecessary film and the like by flowing an etching gas in order to remove the unnecessary film and particles adhering to the inside of the processing container. Is also performed as appropriate.
[0003]
By the way, in one processing apparatus, there are cases where a plurality of types of processing are performed with different processing conditions even in the above-described different types of processing or the same type of processing. In general, an exhaust system provided in a processing apparatus is designed in consideration of a pressure range during processing in which the processing apparatus is used, and an exhaust conductance is optimized within a working pressure range. The diameter of the exhaust pipe is set, and the type of the vacuum pump is also set so as to be suitable for the operating pressure range.
As described above, in the case where it is planned to perform different processes or a plurality of processes with different processing conditions even in the same type of process in one processing apparatus, the process pressure and the process pressure are relatively low. However, it is required to stably control the pressure in the processing container in each pressure region. In this case, in the conventional processing apparatus, the pressure in the processing container is detected, and the pressure adjusting valve of the exhaust system is controlled based on the detected value, or the ballast gas is introduced while controlling the flow rate to the exhaust system. (See Patent Document 1).
[0004]
As another conventional device, a bypass line is provided in the exhaust system and used.
There is also known an apparatus which is used by switching according to the pressure range. An example of this conventional apparatus will be described with reference to FIG. FIG. 6 is a schematic configuration diagram showing an example of a conventional processing apparatus.
As shown in the figure, this processing apparatus 2 has a cylindrical processing vessel 4 made of, for example, aluminum that can be evacuated, and a mounting table provided with heating means 6 such as a heater inside. 8 is provided so that the semiconductor wafer W can be mounted and fixed on the mounting table 8. Further, for example, a shower head portion 10 is provided on the ceiling portion of the processing container 4 as a gas introducing means for introducing various processing gases into the processing container 4. The shower head portion 10 is provided on the lower surface of the shower head portion 10. Gas is jetted downward from a large number of gas jet holes 10A.
[0005]
The shower head unit 10 includes Ar, He, N₂ An inert gas supply system 12 that supplies an inert gas such as a plurality of systems, that is, three processing gas supply systems 14, 16, and 18 in the illustrated example are connected to each other. For example, in the first processing gas supply system 14, WF is used as a processing gas during film formation.₆ A gas is supplied, and the second processing gas supply system 16 uses H as a processing gas during film formation.₂ Gas is supplied, and the third processing gas supply system 18 uses ClF as a processing gas (cleaning gas) during the cleaning process._Three Gas is supplied. Further, in the middle of the inert gas supply system 12 and in the middle of each of the first to third processing gas supply systems 14 to 18, flow rate control units 12 </ b> A and 14 </ b> A composed of, for example, a mass flow controller or the like in order to control the flow rate of the flowing gas. , 16A, and 18A are interposed. In addition, on-off valves 22, 24, 26, and 28 are set on the upstream side and the downstream side of the respective flow rate control units 12A to 18A, and these can be opened and closed as necessary.
[0006]
On the other hand, an exhaust port 30 is provided at the bottom of the processing container 4, and a vacuum exhaust system 32 is connected to the exhaust port 30. The evacuation system 32 has a main exhaust pipe 34 having a large inner diameter and a large exhaust conductance. The main exhaust pipe 34 is like a throttle valve from the upstream side toward the downstream side. A first pressure control valve 36 and a vacuum pump 38, which are adjustable in valve opening, are sequentially provided. An opening / closing valve 40 is interposed immediately before and immediately after the first pressure control valve 36.
Further, a bypass exhaust pipe 42 having an inner diameter smaller than that of the main exhaust pipe 34 and a reduced exhaust conductance so as to bypass the first pressure control valve 36 and the on-off valves 40 immediately before and after the first pressure control valve 36. It is connected. The bypass exhaust pipe 42 is provided with a second pressure control valve 44 whose opening degree is adjustable like a throttle valve, and immediately before and after the second pressure control valve 44. In addition, an on-off valve 46 is interposed.
[0007]
The processing vessel 4 is provided with a pressure gauge 48 for detecting the internal pressure. Based on the detected value of the pressure gauge 48, a control means 54 such as a microcomputer or the like controls each flow rate. The parts 12A to 18A, the first and second pressure control valves 36 and 44, the vacuum pump 38, and the opening and closing operations of the opening and closing valves 22 to 28, 40 and 46 are controlled. The control means 54 also controls the overall operation of the processing apparatus 2, and the control operation is performed based on a plurality of processing programs (also referred to as recipes) incorporated in advance.
For example, when a tungsten film is formed as a low-pressure process with a low processing pressure, for example, WF₆ Gas and H₂ Only the gas is allowed to flow while controlling the flow rate to a predetermined value (inert gas may be allowed to flow if necessary). At the same time, the bypass exhaust pipe 42 closes the on-off valve 46 to the bypass exhaust pipe 42. The main exhaust pipe 34 keeps the pressure in the processing container 4 constant by preventing the gas from flowing and adjusting the valve opening degree of the first pressure control valve 36 by opening the on-off valve 40.
[0008]
On the other hand, when performing a cleaning process as a high-pressure process having a high process pressure, for example, ClF_Three The main exhaust pipe 34 closes the opening / closing valve 40 and closes the first pressure control valve 36 at the same time. The bypass exhaust pipe 42 is treated by adjusting the valve opening of the second pressure control valve 44 while allowing the gas to flow through the bypass exhaust pipe 42 with the on-off valve 46 open. The pressure in the container 4 is kept constant.
[0009]
In this way, by switching between the main exhaust pipe 34 and the bypass exhaust pipe 42 depending on whether the processing pressure is large or small, it is possible to cope with a plurality of types of processing having a large difference in operating pressure range. Yes. In addition, as processing with high processing pressure, there exist oxidation processing, diffusion processing, etc. other than the said cleaning processing.
In addition, as a technique related to the present invention, there is a technique disclosed in Patent Document 2 as a processing apparatus provided with a bypass exhaust pipe in order to cope with differences in the operating pressure range when a plurality of vacuum pumps are provided. Are known.
[0010]
[Patent Document 1]
Japanese Patent Laid-Open No. 10-111152 (page 2-4, FIGS. 1 to 5)
[Patent Document 2]
JP-A-8-290050 (page 4-5, FIG. 1)
[0011]
[Problems to be solved by the invention]
By the way, in the conventional apparatus example of Patent Document 1, since the ballast gas whose flow rate is controlled is introduced into the exhaust system, it is sufficient when the processing pressure is changed in a wide range. The structure was not compatible. In addition, since a large amount of useless inert gas is used, the operating cost of the apparatus is increased.
Further, in the conventional apparatus shown in FIG. 6, since it is necessary to provide the bypass exhaust pipe 42 in which the second pressure control valve 44 is interposed, not only the cost of the apparatus itself is increased, but also the parts. Since there are many points, a lot of time is required for maintenance, and there is a problem that the maintainability is inferior.
The present invention has been devised to pay attention to the above problems and to effectively solve them. The object of the present invention is to appropriately perform pressure control of each process without using a bypass pipe or a plurality of pressure control valves even when performing a plurality of types of processes having greatly different processing pressure ranges. To provide a processing apparatus and a processing method.
Another object of the present invention is to provide a processing apparatus and a processing method capable of appropriately performing pressure control of each processing without using a plurality of pressure control valves.
[0012]
[Means for Solving the Problems]
  According to a first aspect of the present invention, there is provided a processing apparatus for performing a plurality of processes having different processing pressures, a processing container having a mounting table for mounting an object to be processed therein, and a gas introducing means for introducing a gas into the processing container. And connected to the gas introduction means, and a flow rate control unit is interposed in the middle.Several differentSupply processing gasMultiple processingA gas supply system and an inert gas supply system connected to the gas introduction means and provided with a flow rate control unit in the middle to supply an inert gas, and connected to the processing vessel and a valve opening degree in the middle An evacuation system in which a pressure control valve and a vacuum pump are settable, a pressure gauge provided in the processing vessel, and a process having a lower processing pressure among the plurality of processes.Film formation processWhen doingMultiple locationsFor flow control part of physical gas supply systemOne for eachWhile controlling the valve opening degree of the pressure control valve based on the detected value of the pressure gauge while giving a command to flow a constant flow rate, the lower processing pressure is maintained and the higher processing pressure is processed.Cleaning processWhen performing, the valve opening degree of the pressure control valve is fixed to a predetermined value, and the flow rate is controlled by the flow rate control unit of the inert gas supply system based on the detected value of the pressure gauge, so that the processing pressure is higher And a control unit that operates to maintain the pressure.
[0013]
  As described above, among the plurality of processes having different process pressures, the process having the lower process pressure is performed.Film formation processWhen performing cleaning, the pressure in the processing container is controlled by adjusting the valve opening of the pressure control valve while maintaining the flow rate of the processing gas constant, and pressure control is performed when performing the cleaning process, which is the process with the higher processing pressure. Since the pressure in the processing container is controlled by adjusting the flow rate of the inert gas while the valve opening degree is fixed to a predetermined value, a plurality of types of processing with greatly different processing pressure ranges are performed. Even in this case, the pressure control of each process can be appropriately performed without using a bypass pipe or a plurality of pressure control valves.Further, the processing time of the cleaning process is shortened, and the throughput can be improved.
[0014]
  In this case, for example, billingIn item 2As specified, beforeThe vacuum exhaust system has a second vacuum.A pump is provided, and a bypass exhaust path is provided that bypasses the pressure control valve of the vacuum exhaust system and the second vacuum pump and has a switching on-off valve in the middle.
[0015]
  ClaimSection 3The present invention prescribes a method invention performed using the apparatus invention according to claim 1, that is, a processing container having a mounting table on which an object to be processed is placed, and into the processing container. A gas introduction means for introducing gas, and a flow rate control unit interposed between the gas introduction means and the gas introduction means;Multiple differentSupply processing gasMultiple processingA gas supply system and an inert gas supply system connected to the gas introduction means and provided with a flow rate control unit in the middle to supply an inert gas, and connected to the processing vessel and a valve opening degree in the middle Is configured to control each flow rate control unit based on a vacuum exhaust system provided with a pressure control valve and a vacuum pump, a pressure gauge provided in the processing container, and a detected value of the pressure gauge. And a control device that performs a plurality of processes with different processing pressures using a processing apparatus having a control means.The film forming processSaidMultiple locationsFlow rate of processing gas flowing into the physical gas supply systemEach constantThe lower pressure of the processing pressure is maintained by controlling the valve opening degree of the pressure control valve based on the detected value of the pressure gauge while maintaining the processing pressure of the higher processing pressure.Cleaning processWhen performing, the valve opening degree of the pressure control valve is fixed to a predetermined value, and the flow rate of the inert gas flowing through the inert gas supply system is controlled based on the detected value of the pressure gauge to increase the processing pressure. The processing method is characterized in that the pressure in the direction is maintained.
[0016]
  In this case, for example, billingIn item 4As specified, the vacuum pump is used to process the lower processing pressure.And the film forming processProcessing with higher processing pressureIn the cleaning processThe rotational speed is controlled to be different.
  Also for example billingItem 5As specified, the plurality of processes are exhausted by the one vacuum exhaust system.
[0017]
  ClaimSection 6The invention includes a processing container having a mounting table on which an object to be processed is placed, a gas introduction means for introducing gas into the processing container, and a flow rate controller connected to the gas introduction means. IntervenedSeveral differentSupply gasMultiplePressure control connected to the gas supply system and the processing vessel, and the first vacuum pump, the second vacuum pump, and the valve opening can be arbitrarily set in the middleValve and on-off valveIn the processing apparatus for performing a plurality of processes having different processing pressures, comprising an interposed vacuum exhaust system and a pressure gauge for detecting the pressure of the processing container, the pressure control valve and the second vacuum pumpAnd the on-off valveA bypass exhaust path is provided to bypass the first bypass on-off valve interposed in the bypass exhaust pipe of the bypass exhaust path, and an auxiliary provided to bypass the first bypass on-off valve The process vessel is evacuated from atmospheric pressure by a bypass exhaust pipe, a second bypass on-off valve provided in the auxiliary bypass exhaust pipe, and an orifice mechanism provided in the auxiliary bypass exhaust pipe. A soft start valve mechanism having a function of reducing the impact of evacuation is performed, and the treatment with the lower treatment pressure among the plurality of treatments is performed.Film formation processWhen doingIs a command to send a constant flow rate to the flow rate control unit of each of the plurality of gas supply systems.The pressure in the processing vessel is controlled by adjusting the valve opening degree of the pressure control valve based on the detected value of the pressure gauge, and the processing with the higher processing pressure is performed.Cleaning processWhen to doBy closing the on-off valveWhile stopping the exhaust to the pressure control valve side,The first bypass opening / closing valve is closed and the second bypass opening / closing valve is opened.While maintaining the soft start valve mechanism in a low exhaust conductance state, the exhaust gas flows through the bypass exhaust path.Based on the detected value of the pressure gauge, the flow rate is controlled by the flow rate control unit.adjustTo control the pressure in the processing vesselA processing apparatus is characterized in that a control means is provided.
[0018]
  As described above, when the bypass exhaust path is provided in the vacuum exhaust system and the soft start valve mechanism is interposed in the bypass exhaust path, when a plurality of processes having different process pressures are performed, for example, the process with the lower process pressure is performed.Perform the film forming processAt this time, the pressure inside the processing vessel is controlled by adjusting the valve opening degree of the pressure control valve, and the processing with the higher processing pressure is performed.Cleaning processWhen performing, the pressure in the processing vessel may be set by stopping the exhaust to the pressure control valve side, maintaining the soft start valve mechanism in a low exhaust conductance state, and flowing the exhaust gas through the bypass exhaust path. Therefore, it is not necessary to provide a plurality of pressure control valves that are expensive and have a large structure, and the overall structure of the exhaust system can be reduced in size and simplified.
[0019]
  Processing pressureThe place where the power is highCleaning processWhen performing, it is possible to control the pressure in the processing container by adjusting the gas flow rate by the flow rate control unit.
[0020]
  ClaimItem 7The invention relates to a processing container having a mounting table on which an object to be processed is placed, a gas introducing means for introducing gas into the processing container, and a flow control unit connected to the gas introducing means. IntervenedSeveral differentSupply gasMultipleAnd a pressure control valve connected to the processing vessel and capable of arbitrarily setting the first vacuum pump, the second vacuum pump, and the valve opening in the middle.And the on-off valveIn the processing apparatus that includes a vacuum exhaust system interposed and a pressure gauge that detects the pressure of the processing container and performs a plurality of processings having different processing pressures, the pressure control valve and the second vacuum pumpAnd the on-off valveA bypass exhaust path is provided by detouring, and a soft start valve is provided in the bypass exhaust path, the soft start valve having a function of reducing the impact of evacuation when the inside of the processing vessel is evacuated from atmospheric pressure. Of which processing pressure is lowerFilm formation processWhen to doWhile instructing each of the flow control units of each of the plurality of gas supply systems to flow a constant flow rate,The pressure in the processing container is controlled by adjusting the valve opening degree of the pressure control valve based on the detected value of the pressure gauge, and the processing with the higher processing pressure is performed.Cleaning processWhen to doBy closing the on-off valveThe exhaust to the pressure control valve side is stopped, and the soft start valve is maintained in a low exhaust conductance state, and exhaust gas is supplied to the bypass exhaust path.The pressure in the processing vessel is controlled by adjusting the flow rate with the flow rate control unit based on the detected value of the pressure gauge while flowing.The processing apparatus is characterized in that the control means is provided.
[0021]
  ClaimItem 8The invention relates to a processing container having a mounting table on which an object to be processed is placed, a gas introducing means for introducing gas into the processing container, and a flow control unit connected to the gas introducing means. IntervenedSeveral differentSupply gasMultipleAnd a pressure control valve connected to the processing vessel and capable of arbitrarily setting the first vacuum pump, the second vacuum pump, and the valve opening in the middle.And the on-off valveIn the processing method for performing a plurality of processes having different processing pressures using a processing apparatus having an interposed vacuum exhaust system and a pressure gauge for detecting the pressure of the processing container, the pressure control valve and the second With vacuum pumpThe on-off valveA bypass exhaust path is provided by detouring, and a first bypass on-off valve interposed in the bypass exhaust pipe of the bypass exhaust path and an auxiliary bypass provided to bypass the first bypass on-off valve An exhaust pipe, a second bypass on-off valve provided in the auxiliary bypass exhaust pipe, and an orifice mechanism provided in the auxiliary bypass exhaust pipe are used to evacuate the processing vessel from atmospheric pressure. In this case, a soft start valve mechanism having a function of reducing the impact of evacuation is interposed.Film formation processWhen to doWhile instructing each of the flow control units of each of the plurality of gas supply systems to flow a constant flow rate,The pressure in the processing container is controlled by adjusting the valve opening degree of the pressure control valve based on the detected value of the pressure gauge, and the processing with the higher processing pressure is performed.Cleaning processWhen to doBy closing the on-off valveWhile stopping the exhaust to the pressure control valve side,By closing the first bypass on-off valve and opening the second bypass on-off valveWhile maintaining the soft start valve mechanism in a low exhaust conductance state, exhaust gas flows through the bypass exhaust path.Based on the detected value of the pressure gauge, the flow rate is controlled by the flow rate control unit.adjustTo control the pressure in the processing vesselThis is a processing method characterized by the above.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a processing apparatus and a processing method according to the present invention will be described in detail with reference to the accompanying drawings.
<First embodiment>
FIG. 1 is a schematic block diagram showing a first embodiment of the processing apparatus according to the present invention, FIG. 2 is a flowchart showing the steps of the first processing method, and FIG. 3 is a flowchart showing the steps of the second processing method. The same components as those described with reference to FIG. Note that “a process in which the partial pressure of the processing gas is relatively important” described below generally refers to a process with a low processing pressure (low pressure processing), and “the partial pressure of the processing gas is not relatively important. “Processing” generally refers to processing with high processing pressure (high pressure processing).
[0023]
As shown in the figure, the processing apparatus 52 has a cylindrical processing container 4 made of, for example, aluminum that can be evacuated, and a mounting table provided with heating means 6 such as a heater inside. 8 is provided so that the semiconductor wafer W can be mounted and fixed on the mounting table 8. Further, for example, a shower head portion 10 is provided on the ceiling portion of the processing container 4 as a gas introducing means for introducing various processing gases into the processing container 4. The shower head portion 10 is provided on the lower surface of the shower head portion 10. Gas is jetted downward from a large number of gas jet holes 10A.
[0024]
The shower head unit 10 includes Ar, He, N₂ An inert gas supply system 12 that supplies an inert gas such as a plurality of systems, that is, three processing gas supply systems 14, 16, and 18 in the illustrated example are connected to each other. For example, in the first processing gas supply system 14, WF is used as a processing gas during film formation.₆ A gas is supplied, and the second processing gas supply system 16 uses H as a processing gas during film formation.₂ Gas is supplied, and the third processing gas supply system 18 uses ClF as a processing gas (cleaning gas) during the cleaning process._Three Gas is supplied. In this case, the WF is formed when the tungsten film is formed.₆ Gas and H₂ A gas is supplied at the same time, and an inert gas is supplied as needed during the film formation.
[0025]
Further, in the middle of the inert gas supply system 12 and in the middle of each of the first to third processing gas supply systems 14 to 18, flow rate control units 12 </ b> A and 14 </ b> A composed of, for example, a mass flow controller or the like in order to control the flow rate of the flowing gas. , 16A, and 18A are interposed. In addition, on-off valves 22, 24, 26, and 28 are respectively installed on the upstream side and the downstream side of the respective flow rate control units 12A to 18A, and these can be opened and closed as necessary.
[0026]
On the other hand, an exhaust port 30 is provided at the bottom of the processing container 4, and a vacuum exhaust system 32 is connected to the exhaust port 30. The evacuation system 32 has an exhaust pipe 34 having an increased inner diameter and increased exhaust conductance. The inner diameter of the exhaust pipe 34 is, for example, about 100 to 150 mm. The exhaust pipe 34 is sequentially provided with a pressure control valve 36 whose valve opening can be adjusted like a throttle valve from the upstream side toward the downstream side, and a first vacuum pump 38 made of, for example, a dry pump. It is installed. An opening / closing valve 40 is interposed immediately before and immediately after the pressure control valve 36. Here, the evacuation system 32 is configured so as to realize an optimum evacuation conductance required for the process in which the partial pressure of the processing gas must be accurately controlled, that is, the tungsten film forming process here. The inner diameter and the capabilities of the pressure control valve 36 and the vacuum pump 38 are set. In this embodiment, the bypass exhaust pipe 42 and the second pressure control valve 44 used in the conventional apparatus are not provided (see FIG. 6).
[0027]
The processing vessel 4 is provided with a pressure gauge 48 for detecting the internal pressure. Based on the detected value of the pressure gauge 48, a control means 54 such as a microcomputer or the like controls each flow rate. The opening / closing operations of the parts 12A to 18A, the pressure control valve 36, the vacuum pump 38, and the opening / closing valves 22 to 28, 40 are controlled. The control means 54 also controls the overall operation of the processing device 52, and the control operation is performed based on a plurality of processing programs (recipes) incorporated in advance.
[0028]
As will be described later, when a process in which the partial pressure of the processing gas is important, for example, when a tungsten film is formed as a low-pressure process with a low processing pressure, WF is used.₆ Gas and H₂ Only gas is flowed while controlling the flow rate to a predetermined value (inert gas may be flowed if necessary), and at the same time, by adjusting the valve opening of the pressure control valve 36, Maintain a constant pressure. As the pressure control valve 36, a pressure control valve that is within a range in which the operation characteristic of the pressure control valve 36 operates most accurately is selected.
On the other hand, when performing a process in which the partial pressure of the process gas is relatively unimportant, for example, a cleaning process or the like as a high pressure process having a high process pressure, ClF_Three By adjusting the flow rate of the inert gas while maintaining the valve opening degree of the pressure control valve 36 at the predetermined valve opening degree simultaneously with flowing the inert gas while controlling the flow rate to a predetermined value. The pressure in the processing container 4 is maintained substantially constant. Note that high-pressure treatment with a high treatment pressure includes, for example, oxidation treatment and diffusion treatment.
[0029]
Next, a processing method performed using the processing apparatus configured as described above will be described.
In this processing apparatus 52, various processes in which the partial pressure of the processing gas is important, for example, a process for forming a tungsten film and a process in which the partial pressure of the processing gas is relatively insignificant, such as a cleaning process, are performed. The case will be described. Here, “processing” includes not only the case where the semiconductor wafer W exists in the processing container 4 but also the processing such as the cleaning processing performed when the semiconductor wafer W does not exist.
[0030]
<Processing in which partial pressure of process gas is important: Tungsten film formation process>
First, a case where the partial pressure of the processing gas is important will be described.
Here, the process in which the partial pressure of the process gas is important is, for example, WF₆ Gas and H₂ It is a film-forming process that deposits a tungsten film using a gas, and a tungsten film with good electrical characteristics is maintained at an appropriate film-forming rate and with high in-plane film thickness uniformity within the wafer surface. In order to deposit in a state, the flow rates, flow ratios, processing pressures, processing temperatures, etc. of the two gases must be maintained with high accuracy. Such processing is performed as shown in the flowchart of FIG.
[0031]
First, when an unprocessed semiconductor wafer W is mounted on the mounting table 8 of the processing container 4, the inside of the processing container 4 is evacuated by driving the vacuum pump 38 of the vacuum exhaust system 32, and then the vacuum pump 38. Is maintained at a predetermined number of rotations for film formation (S1). This rotational speed may be different from that during the cleaning process. At the same time, the wafer W is heated and set to a predetermined temperature (S2). And WF to start the film formation process₆ Gas and H₂ Each gas is set to a predetermined flow rate to flow, and a tungsten film is deposited (S3). During the film forming process, the pressure in the processing container 4 is constantly detected by the pressure gauge 48 (S4), and the detected pressure value is compared with a preset value set in the control means 54 to detect the detected value. The valve opening degree of the pressure control valve 36 interposed in the exhaust pipe 34 is adjusted as appropriate so that becomes equal to the set value (NO in S5, S6). The film forming process is performed for a predetermined time (YES in S5, NO in S7). If this film forming process is performed for a predetermined time (YES in S7), the process is terminated. The film forming process time is considerably longer than the adjustment time (about several seconds) of the pressure control valve 36, and the film thickness is hardly affected during the film forming process.
[0032]
<Processing where the partial pressure of the processing gas is relatively unimportant: Cleaning process>
Next, a case where the partial pressure of the processing gas is relatively unimportant will be described.
Here, the process in which the partial pressure of the processing gas is relatively insignificant is a cleaning process in which, for example, an excessive adhesion film in the processing container is removed using a cleaning gas, and a predetermined etching rate is guaranteed. Therefore, it is necessary to maintain the flow rate of the cleaning gas and the processing pressure at predetermined set values, respectively. The processing pressure at this time is a set value that is considerably higher than the processing pressure during the previous film formation process. Such processing is performed, for example, as shown in the flowchart of FIG.
[0033]
First, the wafer W is taken out from the processing container 4 and the processing container 4 is hermetically sealed, and the vacuum pump 38 is set to a predetermined number of rotations for cleaning and maintained (S11). Next, an inert gas such as Ar gas is allowed to flow, and at the same time, a cleaning gas such as ClF is used as a processing gas._Three The cleaning process is started by flowing the gas at a predetermined flow rate (S12). At the same time, the pressure control valve 36 is set to a predetermined valve opening, and this state is continuously maintained (S13). This valve opening is experimentally determined in advance so that the exhaust conductance of the vacuum exhaust system 32 during the cleaning process is optimized.
[0034]
During the cleaning process, the pressure in the processing container 4 is constantly detected by the pressure gauge 48 (S14), and the detected pressure value is compared with a preset value set in the control means 54, and the detected value is The flow rate control unit 12A interposed in the inert gas supply system 12 is appropriately adjusted so as to be the same as the set value (NO in S15, S16). During this time, ClF_Three The gas flow rate is always kept constant. The cleaning process is performed for a predetermined time (YES in S15, NO in S17). If this cleaning process is performed for a predetermined time (YES in S17), the process is terminated.
[0035]
As described above, even when a plurality of types of treatments having greatly different processing pressure ranges are performed, such as a tungsten film deposition process or a cleaning process for removing unnecessary deposits in the process container 4, a bypass pipe or Without using a plurality of pressure control valves, the pressure control of each process can be appropriately performed.
Further, since the number of parts to be used is reduced, maintenance can be quickly performed correspondingly, so that maintainability can be improved.
Furthermore, in this case, since the response operation of the flow rate control unit 12A is generally much faster than the response operation of the pressure control valve 36, the pressure control by the flow rate control unit 12A can reach the processing pressure earlier. Therefore, unlike the conventional apparatus that controls the pressure with the pressure control valve in all the processes, the processing time is shortened by the amount of pressure control using the flow control unit with a quick response operation in some processes. Throughput can be improved.
[0036]
Next, unlike the processes described above, when a plurality of types of process gases are used, the process can be executed without degrading the quality of the process results within a certain predetermined partial pressure range. In such a case, when performing such a process, the valve opening of the pressure control valve 36 is set to a large value, for example, 100%, and each process gas is maintained at a constant flow rate ratio. A predetermined process may be performed only by adjusting the flow rate by adjusting the flow rate of the gas to control the pressure in the processing container 4.
Specific examples of such processing include PVD (Physical Vapor Deposition) processing and preclean processing using a preclean device.
In this case, since the processing pressure can be controlled only by the flow control unit having a fast response speed without adjusting the valve opening degree of the pressure control valve 36, the controllability is improved accordingly. Throughput can be increased.
[0037]
<Second embodiment>
In each of the above embodiments, the case where one exhaust pipe 34 as shown in FIG. 1 is provided and one vacuum pump 38 is provided in the exhaust pipe 34 has been described as an example, but one vacuum pump 38 is provided. If the exhaust capability is not sufficient, the second embodiment shown in FIG. 4 may be used. That is, in this case, a second vacuum pump 60 made of, for example, a turbo molecular pump is interposed in series with the pressure control valve 36, and the pressure control valve 36 and the second vacuum pump 60 are connected to each other. The bypass exhaust path 62 is connected to the exhaust pipe 34 so as to make a detour. A switching on / off valve 64 is interposed in the bypass exhaust path 62. The inner diameter of the bypass exhaust path 62 is about 25 to 40 mm.
[0038]
In this embodiment, when evacuating the inside of the processing container 4, first, the on-off valve 40 of the exhaust pipe 34 is closed, and instead, the switching on-off valve 64 of the bypass exhaust pipe 62 is opened to open the bypass exhaust pipe 62. Then, the inside of the processing vessel 4 is roughed by rotating the vacuum pump 38. After the roughing to some extent, if the pressure in the processing container 4 decreases to a predetermined degree of vacuum, the opening / closing valve 40 of the exhaust pipe 34 is opened and the second vacuum pump 60 is also driven to rotate. Then, the switching on / off valve 64 of the bypass exhaust pipe 62 is closed. As a result, evacuation is continued with the two vacuum pumps of the previous vacuum pump 38 and the second vacuum pump 60. Further, when performing a process having a relatively high processing pressure, for example, when performing a cleaning process, the cleaning process may be performed while the on-off valve 40 of the exhaust pipe 34 is closed and only the bypass exhaust pipe 62 is evacuated. . Also in this embodiment, when a plurality of processes having greatly different processing pressure ranges are performed, the same process as described with reference to FIGS. 1 to 3 may be performed.
[0039]
<Third embodiment>
Next, a third embodiment of the present invention will be described.
FIG. 5 is a schematic block diagram showing a third embodiment of the processing apparatus of the present invention. The same components as those described in FIGS. 1, 4 and 6 are denoted by the same reference numerals and description thereof is omitted. The process having a relatively low process pressure described here means a process in which the partial pressure of the process gas described above is important, and the process having a relatively high process pressure is a process gas fraction. It means a process where pressure is not important.
As shown in FIG. 5, here, the main exhaust pipe 34 has a pressure control valve 36, for example, a second vacuum pump 60 made of a turbo molecular pump and a second pump made of a dry pump, for example, from the upstream side to the downstream side. One vacuum pump 38 is sequentially provided, and an opening / closing valve 40 is provided immediately upstream of the pressure control valve 36 and immediately downstream of the second vacuum pump 60.
[0040]
A bypass exhaust path 62 serving as a bypass exhaust pipe is connected to the main exhaust pipe 34 so as to bypass the pressure control valve 36, the second vacuum pump 60 and both the on-off valves 40. As described above, the inner diameter of the main exhaust pipe 34 is, for example, about 100 to 150 mm and a large diameter, and the inner diameter of the bypass exhaust path 62 is about 25 to 40 mm and a small diameter.
A soft start valve mechanism 70 having a function of reducing the impact of evacuation when the inside of the processing container 4 is evacuated from the atmospheric pressure is provided in the middle of the bypass exhaust path 62. Thereby, the control means 54 sets the valve opening degree of the pressure control valve 38 based on the detected value of the pressure gauge 48 provided in the processing container 4 when processing with a relatively low processing pressure (for example, film forming processing) is performed. The pressure in the processing container 4 is controlled by adjusting, and when performing processing with a relatively high processing pressure (for example, cleaning processing, oxidation processing, diffusion processing, etc.), the exhaust to the pressure control valve 36 is stopped and the above processing is performed. The soft start valve mechanism 70 is maintained in a low exhaust conductance state, and the exhaust gas is controlled to flow through the bypass exhaust passage 62.
[0041]
Specifically, the soft start valve mechanism 70 is connected to the bypass exhaust passage 62 so as to bypass the first bypass on / off valve 72 interposed in the bypass exhaust passage 62. The auxiliary bypass exhaust pipe 74 having a small inner diameter, and an orifice mechanism 76 and a second bypass on-off valve 78 sequentially provided in the auxiliary bypass exhaust pipe 74 are provided.
As is well known, the orifice mechanism 76 has an orifice (not shown) for narrowing the flow passage area, closes the first bypass opening / closing valve 72, and sets the second bypass opening / closing valve 78. By setting the open state, the entire soft start valve mechanism 70 can be brought into a low exhaust conductance state. Here, the inner diameters of the bypass exhaust passage 62 and the auxiliary bypass exhaust pipe 74 and the flow passage area of the orifice hole of the orifice mechanism 76 are determined so that the processing gas having a flow rate necessary for processing at a relatively high processing pressure is used. The exhaust conductance is fixed in advance so that the required processing pressure can be substantially obtained when flowing.
In other words, in a process with a relatively high processing pressure, there is often no need to control the process pressure with high precision. In such a case, the pressure control in the processor 4 is performed using a fixed fixed exhaust. The operation is performed by conductance, and the operation such as adjustment of the valve opening is not particularly performed actively.
[0042]
Next, the operation of the embodiment configured as described above will be described.
<When vacuuming from atmospheric pressure>
When the inside of the processing container 4 is in an atmospheric pressure state, and the inside of the processing container 4 is evacuated from this state, the both open / close valves 40 of the main exhaust pipe 34 are first closed to reach a certain degree of vacuum. The second vacuum pump 60 composed of a turbo molecular pump that can only be used later is isolated. At the same time, in the soft start valve mechanism 70, the first bypass opening / closing valve 72 provided in the bypass exhaust passage 62 is closed, and the second bypass opening / closing valve 78 provided in the auxiliary bypass exhaust pipe 74 is opened. Thus, the soft start valve mechanism 70 is brought into a low exhaust conductance state. In this state, the first vacuum pump 38 is driven to start evacuation. In this case, since the atmosphere in the processing container 4 is exhausted only through the orifice hole of the orifice mechanism 76 provided in the auxiliary bypass exhaust pipe 74, the exhaust conductance is considerably low as described above. As a result, the impact of evacuation generated in the processing container 4 is relieved and becomes very small, and it is possible to prevent the structures and particles in the processing container 4 from floating momentarily, and the processing container 4. The unnecessary film adhering to the inner wall surface and the surface of the internal structure is not peeled off, and the generation of particles can be prevented.
[0043]
When the degree of vacuum reaches a certain degree of vacuum (for example, 1330 Pa) as a result of evacuation, the first bypass on-off valve 72 is switched to the open state and evacuation is performed on the entire bypass exhaust path 62. At this time, the second bypass on-off valve 78 may be in either the open or closed state.
Further, when evacuation is performed to reach a predetermined degree of vacuum, that is, about 133 Pa, which is the upper limit pressure value of the turbo molecular pump, the both open / close valves 40 interposed in the main exhaust pipe 34 are switched to the open state, At the same time, the driving of the second vacuum pump 60 is started. At this time, the first pressure control valve 36 is kept fully open. At the same time, both the first and second bypass opening / closing valves 72 and 78 are switched to the closed state. Thus, the inside of the processing container 4 can be evacuated to a low pressure atmosphere.
[0044]
<Processing with low processing pressure: for example, film forming process>
Next, the pressure control in the processing container 4 when the processing at a low processing pressure is performed is substantially the same as the processing in which the partial pressure of the processing gas described in the first embodiment is important.
That is, the first and second bypass on-off valves 72 and 78 of the soft start valve mechanism 70 are both kept closed, and both the on-off valves 40 of the main exhaust pipe 34 are kept open, and the detected value of the pressure gauge 48 is detected. Accordingly, the opening of the pressure control valve 36 is adjusted to control the pressure in the processing container 4. At this time, the flow rate of each gas is maintained at a constant value as defined in the recipe. The process pressure of the process having such a low process pressure is, for example, about several tens of Pa to several hundreds of Pa.
[0045]
<Treatment with high treatment pressure: for example, cleaning treatment or oxidation treatment>
Next, pressure control in the processing container 4 when processing with high processing pressure is performed will be described.
In this case, a low exhaust conductance state is set as in the case where evacuation is started from the inside of the processing container 4 at atmospheric pressure. That is, contrary to the film forming process described above, both the on-off valves 40 interposed in the main exhaust pipe 34 are kept closed to isolate the first vacuum pump 60. With respect to the soft start valve mechanism 70, the first bypass opening / closing valve 72 is maintained in the closed state, and conversely, the second bypass opening / closing valve 78 is maintained in the open state, and the auxiliary bypass exhaust pipe is connected via the orifice mechanism 76. The exhaust gas is evacuated only through 74. At this time, the exhaust conductance of the soft start valve mechanism 70 is, for example, approximately the same as the exhaust conductance of the pressure control valve 36 in which a slight gap is generated even when the soft start valve mechanism 70 is fully closed.
[0046]
Thereby, it can process in the state which made the process pressure in the processing container 4 high. Thus, the process pressure of the process with a high process pressure is a pressure of about several thousand Pa to 20000 Pa, for example.
In the processing with the high processing pressure, the pressure in the processing container 4 could not be actively controlled. However, the pressure is not limited to this. For example, the pressure in the processing container 4 at this time is detected by the pressure gauge 48. When the flow rate controller is adjusted and controlled through the control means 54 so that the detected value maintains a predetermined pressure, a gas flow rate, for example, a flow rate of an inert gas or a cleaning gas, or an oxidation process is performed. Alternatively, the flow rate of the oxidizing gas may be controlled.
[0047]
This makes it possible to control the process pressure with high accuracy even when the process pressure is high.
The soft start valve mechanism 70 has been described by taking as an example the case where the soft start valve mechanism 70 is configured by the auxiliary bypass exhaust pipe 74, the first and second bypass on-off valves 72 and 78, and the orifice mechanism 76. A function capable of completely setting the inside of the bypass exhaust path 62 in a cut-off state, a function capable of setting the bypass exhaust path 62 to a low exhaust conductance state, and a medium level within the bypass exhaust path 62 which is somewhat higher than the low exhaust conductance. For example, a soft start valve (registered trademark) manufactured by SMC may be used, which has the above-described three functions that can be set to the exhaust conductance state.
In each of the above embodiments, the case where the tungsten film is formed has been described as an example. However, the present invention can also be applied to the case where other film types are formed.
[0048]
Further, the process in which the partial pressure of the process gas is important is not limited to the film forming process, and can be applied to other processes. Similarly, the process in which the partial pressure of the process gas is relatively insignificant is not limited to the cleaning process, and may be applied to other processes, for example, when performing an oxidation process or a diffusion process as described above. Can do.
Further, the supply form of each gas is merely an example, and if the type of processing gas increases or decreases, the number of gas supply systems increases or decreases accordingly, and the configuration of the shower head unit 10 also increases. The present invention can be applied to either a premix type in which the processing gas is mixed in advance before being injected into the processing container 4 or a postmix type in which the processing gas is mixed after being injected from the shower head unit 10. Further, the present invention can also be applied to a gas introduction means that does not use the shower head unit 10.
[0049]
Although the single wafer processing apparatus has been described here as an example, the present invention can also be applied to a batch processing apparatus capable of processing a plurality of objects to be processed at one time.
Also, control by the mass flow controller is often used in PVD processing performed within a predetermined partial pressure range, and the pressure control valve is often used in CVD processing. It can be applied to the case where both the CVD process and the CVD process are performed.
Furthermore, in the above-described embodiments, the semiconductor wafer has been described as an example of the object to be processed. However, the present invention is not limited to this and can be applied to a glass substrate, an LCD substrate, or the like.
In the above embodiment, either the temperature control unit or the pressure control valve is made constant during the pressure control, but the temperature control unit and the pressure control valve are not made constant, and the pressure control is always performed by both operations. It may be.
[0050]
【The invention's effect】
  As described above, according to the processing apparatus and the processing method of the present invention, the following excellent operational effects can be exhibited.
  Claim1 to 5According to the invention, a plurality of types of treatments having greatly different processing pressure ranges,That is, the film formation process and the cleaning processAlso when performing, the pressure control of each process can be performed appropriately, without using a bypass pipe and a plurality of pressure control valves.Further, the processing time of the cleaning process is shortened, and the throughput can be improved.
  In addition, since the number of parts to be used can be reduced because one evacuation system can be used, the maintenance can be performed promptly, so that the maintainability can be improved. Also, the amount of inert gas used can be reduced.
  ClaimItem 6-8According to the invention, the bypass exhaust path is provided in the vacuum exhaust system, and the soft start valve mechanism is interposed in the bypass exhaust path.Film formation processWhen performing, control the pressure in the processing container by adjusting the valve opening of the pressure control valve, so that the treatment with the higher processing pressure is performed.Cleaning processWhen performing, the pressure inside the processing vessel may be set by stopping the exhaust to the pressure control valve side, maintaining the soft start valve mechanism in a low exhaust conductance state, and flowing the exhaust gas to the bypass exhaust path. Therefore, it is not necessary to provide a plurality of pressure control valves which are expensive and have a large structure, and the overall structure of the exhaust system can be made small and simple. Therefore, it is also effective in terms of cost.. Also processing pressureThe place with the higherCleaning processWhen performing, the pressure in the processing container can be controlled by adjusting the gas flow rate by the flow rate control unit.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing a first embodiment of a processing apparatus according to the present invention.
FIG. 2 is a flowchart showing steps of a first processing method.
FIG. 3 is a flowchart showing steps of a second processing method.
FIG. 4 is a schematic block diagram showing a second embodiment of the processing apparatus of the present invention.
FIG. 5 is a schematic block diagram showing a third embodiment of the processing apparatus of the present invention.
FIG. 6 is a schematic configuration diagram showing an example of a conventional processing apparatus.
[Explanation of symbols]
4 processing containers
8 Mounting table
10 Shower head (gas introduction means)
12 Inert gas supply system
14, 16, 18 Process gas supply system
12A, 14A, 16A, 18A Flow control unit
32 Vacuum exhaust system
34 Main exhaust pipe (exhaust pipe)
36 First pressure control valve (pressure control valve)
38 Vacuum pump
48 Pressure gauge
52 Processing equipment
54 Control means
60 second vacuum pump
62 Bypass exhaust path
64 On-off valve for switching
70 Soft start valve mechanism
72 First bypass on-off valve
74 Auxiliary bypass exhaust pipe
76 Orifice mechanism
78 Second bypass on-off valve
W Semiconductor wafer (object to be processed)

Claims

In a processing apparatus that performs a plurality of processes having different processing pressures,
A processing container having a mounting table for mounting an object to be processed inside;
Gas introduction means for introducing gas into the processing vessel;
Is connected to the gas introducing means, and a plurality of processing gas supply systems you provide a plurality of different processing gas flow rate control unit is interposed in the middle,
An inert gas supply system that is connected to the gas introduction means, and in which a flow rate control unit is interposed and supplies an inert gas;
An evacuation system connected to the processing container and having a pressure control valve and a vacuum pump interposed in the middle of which the valve opening can be set;
A pressure gauge provided in the processing container;
Wherein the plurality of processing, the pressure while the instruction to flow a respective constant flow rate to the flow rate control unit of the film forming process treatment pressure is lower processing line cormorants sometimes each of the plurality of processing gas supply systems based on the detected value of the total of maintaining the pressure of the person is the processing pressure by controlling the valve opening of the pressure control valve low, the cleaning process a row cormorants sometimes the pressure control processing pressure is higher processing of The valve opening degree of the valve is fixed to a predetermined value, and the flow rate is controlled by the flow rate control unit of the inert gas supply system based on the detected value of the pressure gauge to maintain the higher processing pressure. Control means to operate as follows:
A processing apparatus comprising:

The evacuation system is provided with a second vacuum pump, and bypasses the pressure control valve of the evacuation system and the second vacuum pump, and is provided with a switching on-off valve in the middle. processing apparatus according to claim 1, wherein the bypass exhaust path is provided.

A processing container having a mounting table for mounting an object to be processed inside;
Gas introduction means for introducing gas into the processing vessel;
Is connected to the gas introducing means, and a plurality of processing gas supply systems you provide a plurality of different processing gas flow rate control unit is interposed in the middle,
An inert gas supply system that is connected to the gas introduction means, and in which a flow rate control unit is interposed and supplies an inert gas;
An evacuation system connected to the processing container and having a pressure control valve and a vacuum pump interposed in the middle of which the valve opening can be set;
A pressure gauge provided in the processing container;
In a method of performing a plurality of processes having different processing pressures using a processing device having a control unit that controls each of the flow rate control units based on a detection value of the pressure gauge,
Among the plurality of processes, when the processing pressure is the film formation processing is lower processing of the pressure gauge while maintaining the flow rate of the processing gas flowing in the plurality of respective processing gas supply systems constant, respectively Based on the detected value, the valve opening degree of the pressure control valve is controlled to maintain the pressure with the lower processing pressure, and when performing the cleaning process, which is the process with the higher processing pressure, the pressure control valve The valve opening is fixed to a predetermined value, and the flow rate of the inert gas flowing through the inert gas supply system is controlled based on the detected value of the pressure gauge so as to maintain the higher processing pressure. A processing method characterized by the above.

The vacuum pump according to claim 3, characterized in that the controlling the rotational speed differently in cleaning the film forming process and the processing pressure the process pressure is lower processing of the processing of the higher The processing method described .

Wherein the one vacuum pumping system, according to claim 3 or 4 SL placing the processing method is characterized in that exhaust of the plurality of processes are performed.

A processing container having a mounting table for mounting an object to be processed inside;
Gas introduction means for introducing gas into the processing vessel;
Is connected to the gas introducing means, and a plurality of gas supply system that to supply several different that gas flow control unit is interposed in the middle,
An evacuation system connected to the processing vessel and having a first vacuum pump, a second vacuum pump, a pressure control valve capable of arbitrarily setting a valve opening degree, and an on-off valve interposed therebetween;
A pressure gauge for detecting the pressure of the processing vessel;
In a processing apparatus for performing a plurality of processes with different processing pressures,
It said divert the pressure control valve and said second vacuum pump and the on-off valve a bypass exhaust path provided, the bypass exhaust path, a first bypass opening and closing, which is interposed in the bypass exhaust pipe of the bypass exhaust gas passage A valve, an auxiliary bypass exhaust pipe provided so as to bypass the first bypass on / off valve, a second bypass on / off valve provided in the auxiliary bypass exhaust pipe, and an orifice provided in the auxiliary bypass exhaust pipe And a soft start valve mechanism having a function of reducing the impact of evacuation when evacuating the inside of the processing vessel from atmospheric pressure,
Among the plurality of processes, when the processing pressure is the film formation process is a lower processing of the pressure gauge while the instruction to flow a respective constant flow rate to the flow rate control unit of the plurality of the gas supply system Controlling the pressure in the processing vessel by adjusting the valve opening of the pressure control valve based on the detected value;
It stops the exhaust Previous Symbol pressure control valve side by a cleaning process processing pressure is higher processing of closing the line cormorants sometimes the on-off valve, and the second to the first bypass opening and closing valve closed 2 By opening the bypass on-off valve, the soft start valve mechanism is maintained in a low exhaust conductance state, and the flow rate is controlled by the flow rate control unit based on the detected value of the pressure gauge while flowing the exhaust gas through the bypass exhaust path. processing apparatus characterized by being configured to provide a control means for controlling the pressure in the processing chamber by adjusting.

A processing container having a mounting table for mounting an object to be processed inside;
Gas introduction means for introducing gas into the processing vessel;
Is connected to the gas introducing means, and a plurality of gas supply systems you provide a plurality of different gas and the flow control unit is interposed in the middle,
An evacuation system connected to the processing vessel and having a first vacuum pump, a second vacuum pump, a pressure control valve capable of arbitrarily setting a valve opening degree, and an on-off valve interposed therebetween;
A pressure gauge for detecting the pressure of the processing vessel;
In a processing apparatus for performing a plurality of processes with different processing pressures,
A bypass exhaust path is provided by bypassing the pressure control valve, the second vacuum pump, and the on-off valve, and an impact of vacuuming is applied to the bypass exhaust path when the inside of the processing vessel is evacuated from atmospheric pressure. A soft start valve having a softening function is provided, and when performing a film forming process which is a process having a lower processing pressure among the plurality of processes, a constant flow rate is provided to each of the flow control units of the plurality of gas supply systems. Controlling the pressure in the processing container by adjusting the valve opening of the pressure control valve based on the detected value of the pressure gauge while
Stops the exhaust Previous Symbol pressure control valve side by closing the on-off valve when the process pressure to perform cleaning process performed in higher, the bypass maintains the soft-start valve low exhaust conductance state and characterized by being configured to provide a control means for controlling the pressure in the processing chamber by adjusting the flow rate by the flow rate controller based on the detected value of the pressure gauge while flowing exhaust gas in the exhaust passage Processing equipment.

A processing container having a mounting table for mounting an object to be processed inside;
Gas introduction means for introducing gas into the processing vessel;
Is connected to the gas introducing means, and a plurality of gas supply system that to supply several different gases flow control unit is interposed in the middle,
An evacuation system connected to the processing vessel and having a first vacuum pump, a second vacuum pump, a pressure control valve capable of arbitrarily setting a valve opening degree, and an on-off valve interposed therebetween;
A pressure gauge for detecting the pressure of the processing vessel;
In a processing method for performing a plurality of processes with different processing pressures using a processing apparatus having
A bypass exhaust path is provided by bypassing the pressure control valve, the second vacuum pump, and the opening / closing valve, and a first bypass opening / closing valve interposed in the bypass exhaust pipe of the bypass exhaust path in the bypass exhaust path An auxiliary bypass exhaust pipe provided to bypass the first bypass open / close valve, a second bypass open / close valve interposed in the auxiliary bypass exhaust pipe, and an orifice mechanism interposed in the auxiliary bypass exhaust pipe And a soft start valve mechanism having a function of reducing the impact of evacuation when the inside of the processing vessel is evacuated from the atmospheric pressure. the valve opening of the pressure control valve on the basis of the detected value of the pressure gauge while the instruction to flow a respective constant flow rate to the flow rate control unit of the plurality of the gas supply system when performing a film forming process is a treatment Adjust Controlling the pressure in the processing chamber by,
Stops the exhaust Previous Symbol pressure control valve side by closing the on-off valve when the process pressure to perform cleaning treatment is higher processing of, the first bypass opening and closing valve are closed and the second By opening the bypass on-off valve, the soft start valve mechanism is maintained in a low exhaust conductance state, and the flow rate is controlled by the flow rate control unit based on the detected value of the pressure gauge while flowing the exhaust gas through the bypass exhaust path. The processing method characterized by controlling the pressure in the said processing container by adjusting.