JP2004336922A - Stage apparatus and its driving method, and aligner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stage technology in which a member to be moved can be driven with high accuracy. <P>SOLUTION: In order to drive a reticle stage RST for holding a reticle R in the direction of Y to a frame member 18, two pairs of Y-axis linear motors 76A, 78A and 76B, 78B are provided. When the reticle stage RST is driven in the direction of Y by the upper Y-axis linear motors 76A, 78A, the lower Y-axis linear motors 76B, 78A are set so as not to generate thrusts, electromotive forces generated from coils of the respective phases are detected, and thrust constants are corrected. Then, when the reticle stage RST is driven in the direction of Y by the lower Y-axis linear motors 76B, 78B, the upper Y-axis linear motors 76A, 78A are set so as not to generate thrusts, electromotive forces generated from the coils of the respective phases are detected, and the thrust constants are corrected. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

ここで（１２）式〜（１４式）における電流ピーク値Ｉｏを１（単位電流）とすると、この推力ＦＢｔは、Ｙ軸リニアモータ７８Ｂ（又は７６Ｂ）全体としての推力定数ＦＢ（Ｙ）と等しくなる。この推力定数ＦＢ（Ｙ）は、図１１の曲線ＣＶとして表されている。この曲線ＣＶから分かるように、本来は一定であるはずの推力定数ＦＢ（Ｙ）が位置Ｙによって僅かに変動している。これは、実測して補正された推力定数ＦＢＵ（Ｙ），ＦＢＷ（Ｙ），ＦＢＶ（Ｙ）が初めに設定されていた推力定数とは僅かに異なっていたことを意味する。
【００９８】
そこで、次に第３及び第４のＹ軸リニアモータ７６Ｂ，７８Ｂを駆動する場合には、図９の電流値設定部１９０は、補正後の推力定数ＦＢＵ（Ｙ），ＦＢＷ（Ｙ），ＦＢＶ（Ｙ）、３相のコイル群に供給される電流ＩＢｕ，ＩＢｗ，ＩＢｖを（１６）式に代入して得られる推力ＦＢｔが目標値となるように、３相の電流ＩＢｕ，ＩＢｗ，ＩＢｖを設定する。これによって、推力定数の実測値に基づいて可動子ユニット２６Ｂ，２８Ｂを目標とする推力で高精度に駆動することができる。
【００９９】
次のステップ２０４において、図８の第１及び第２のＹ軸リニアモータ７６Ａ，７８Ａ用の制御部９０Ａにおいて、例えばオペレータが切替スイッチ１９２Ｕ，１９２Ｗ，１９２Ｖをそれぞれ出力端子１９７Ｕ，１９７Ｗ，１９７Ｖが電圧計測端子１９３Ｕ，１９３Ｗ，１９３Ｖに接続されるように設定する。また、電圧計測端子１９３Ｕ，１９３Ｗ，１９３Ｖに図９の電圧計１９４を接続し、電圧計１９４の計測値がレチクルステージ制御部９０Ｒに取り込まれるようにする。電圧計１９４は、第１及び第２のＹ軸リニアモータ７６Ａ，７８Ａ用に２台用意される。これによって、第１及び第２のＹ軸リニアモータ７６Ａ，７８Ａは推力を発生しない状態に設定されると共に、Ｙ軸リニアモータ７６Ａ，７８ＡのＵ相、Ｗ相、Ｖ相のコイル群１９６Ｕ，１９６Ｗ，１９６Ｖで発生する逆起電力を電圧計１９４によって計測することができる。
【０１００】
更に、図９の第３及び第４のＹ軸リニアモータ７６Ｂ，７８Ｂの制御部９０Ｂにおいて、例えばオペレータが切替スイッチ１９２Ｕ，１９２Ｗ，１９２ＶをそれぞれＵ相、Ｗ相、Ｖ相のアンプ１９１Ｕ，１９１Ｗ，１９１Ｖの出力端子が出力端子１９７Ｕ，１９７Ｗ，１９７Ｖに接続されるように設定する。これによって、第３及び第４のＹ軸リニアモータ７６Ｂ，７８Ｂは、ステップ２０３で補正された推力定数及び上記の（１６）式に基づいて駆動されることになる。
【０１０１】
この状態で、図９の主制御装置７０及びレチクルステージ制御部９０Ｒの制御のもとで、図５の下方の第３及び第４のＹ軸リニアモータ７６Ｂ，７８Ｂを駆動して、レチクルステージＲＳＴ（レチクルステージ本体２２）をＹ方向に全ストロークでほぼ一定速度で駆動する。この動作と並行してステップ２０５で示すように、図８のレチクルステージ制御部９０Ｒは、Ｙ軸レーザ干渉計６９ＹＡ，６９ＹＢの計測値と、２台の電圧計１９４で計測される第１及び第２のＹ軸リニアモータ７６Ｂ，７８Ｂの３相のコイル群１９６Ｕ，１９６Ｗ，１９６Ｖで発生する逆起電力とを所定のサンプリングレートで記憶部に順次取り込む。
【０１０２】
次のステップ２０６において、レチクルステージ制御部９０Ｒは、ステップ２０３と同様にして第１及び第２のＹ軸リニアモータ７６Ａ，７８Ａの各相の推力定数を補正する。補正後の推力定数は、図８の第１及び第２のＹ軸リニアモータ７６Ａ，７８Ａの制御部９０Ａの電流値設定部１９０に設定される。次に第１及び第２のＹ軸リニアモータ７６Ａ，７８Ａを駆動する場合には、図８の電流値設定部１９０は、補正後の推力定数ＦＡＵ（Ｙ），ＦＡＷ（Ｙ），ＦＡＶ（Ｙ）と、３相のコイル群に供給される電流ＩＡｕ，ＩＡｗ，ＩＡｖとを（１５）式に代入して得られる推力ＦＡｔが目標値となるように、３相の電流ＩＡｕ，ＩＡｗ，ＩＡｖを設定する。これによって、推力定数の実測値に基づいて可動子ユニット２６Ａ，２８Ａを目標とする推力で高精度に駆動することができる。
【０１０３】
この結果、図５の４軸のＹ軸リニアモータ７６Ａ，７８Ａ，７６Ｂ，７８Ｂの推力定数を、実際の露光工程で使用される投影露光装置に装着した状態で計測した逆起電力に基づいて正確に補正できたことになる。従って、Ｙ軸リニアモータ７６Ａ，７８Ａ，７６Ｂ，７８Ｂの取り付け誤差等に起因する推力誤差が補正されるため、位置決め性や等速性を向上させることができる。
【０１０４】
次のステップ２０７において、例えばオペレータが、図８の第１及び第２のＹ軸リニアモータ７６Ａ，７８Ａの制御部９０Ａにおいて、切替スイッチ１９２Ｕ，１９２Ｗ，１９２ＶをそれぞれＵ相、Ｗ相、Ｖ相のアンプ１９１Ｕ，１９１Ｗ，１９１Ｖの出力端子が出力端子１９７Ｕ，１９７Ｗ，１９７Ｖに接続されるように設定する。これ以降は、４軸のＹ軸リニアモータ７６Ａ，７８Ａ，７６Ｂ，７８Ｂは補正後の推力定数を用いて同期して駆動することができる。
【０１０５】
そこで、一例として図８の主制御装置７０及びレチクルステージ制御部９０Ｒの制御のもとで、図５の４軸のＹ軸リニアモータ７６Ａ，７８Ａ，７６Ｂ，７８Ｂを同期して駆動することによって、レチクルステージＲＳＴをＹ方向及びθｚ方向に駆動して、レチクルステージＲＳＴをレチクルロード位置に移動する。その後、ステップ２０８において通常の露光工程が実行される。この露光工程では、図５の４軸のＹ軸リニアモータ７６Ａ，７８Ａ，７６Ｂ，７８Ｂは補正後の推力定数を用いて駆動されるため、レチクルステージＲＳＴ（レチクルＲ）を所望の推力で高精度に駆動することができる。
【０１０６】
但し、本例では、別途、電圧計１９４を用意して、逆起電力の計測時に制御部９０Ａ，９０Ｂの切替スイッチ１９２Ｕ，１９２Ｗ，１９２Ｖの切り替えや配線の接続を行う必要がある。しかしながら、装置本体に電圧計を常備する必要が無く、装置全体のコストが上昇しないという利点がある。
また、上記の逆起電力の計測値から推力定数を求めるためのソフトウェア（プログラム）は、レチクルステージ制御部９０Ｒ内に記憶されている。その他に、その逆起電力の計測値から推力定数を求める動作を外部のコンピュータで実行し、求められた推力定数をオペレータがレチクルステージ制御部９０Ｒに書き込むようにしてもよい。
【０１０７】
上述のように、本例の図７に示すＹ軸リニアモータ７８Ａ，７８Ｂの固定子ユニット１３８Ａ，１３８Ｂは、配列ピッチＰ１が２Ｐ／３の複数のコイルより構成されている。その変形例として、図７に対応する部分に同一又は類似の符号を付した図１３に示すように、その固定子ユニットを構成する複数のコイルをより小さいピッチで配置してもよい。
【０１０８】
図１３（Ａ）は、その変形例のＹ軸リニアモータ７８Ａの固定子ユニット１９８Ａを示す平面図、図１３（Ｂ）はそのＹ軸リニアモータ７８Ａの可動子ユニット２８Ａを示す平面図、図１３（Ｃ）は図１３（Ｂ）の側面図、図１３（Ｄ）は図１３（Ｂ）の正面図、図１３（Ｅ）は可動子ユニット２８Ａの磁石によって発生する磁束密度Ｂ（ピッチＰ）のＹ方向の分布をそれぞれ表している。
【０１０９】
図１３（Ｄ）に示すように、この変形例の１対のＹ軸リニアモータ７８Ａ及び７８Ｂは、それぞれ固定子ユニット１９８Ａ及び１９８Ｂと、可動子ユニット２８Ａ及び２８Ｂとを有し、可動子ユニット２８Ａ，２８Ｂの構成は図７の例と同様である。一方、上方の固定子ユニット１９８Ａは、３層のコイルユニットを磁界の方向（Ｚ方向）に重ねて構成され、第１層目のコイルユニットは、Ｚ方向の磁界をＸ方向に横切るＵ相（０π）のコイルＣＵ、Ｖ相（−２π／３）のコイルＣＶ、Ｗ相（＋２π／３）のコイルＣＷをＹ方向にピッチＰ１（＝２Ｐ／３）で順次配列したものである。また、第２層目のコイルユニットは、第１層目のコイルＣＵ，ＣＶ，ＣＷ，…をそれぞれＰ２（＝Ｐ／６）だけＹ方向にずらしたコイルＣＶ１（Ｖ相），ＣＷ１（Ｗ相），ＣＵ１（Ｕ相），…から構成され、第３層目のコイルユニットは、第２層目のコイルＣＶ１，ＣＷ１，ＣＵ１，…を更にそれぞれＰ２（＝Ｐ／６）だけＹ方向にずらしたコイルＣＷ２（Ｗ相），ＣＵ２（Ｕ相），ＣＶ２（Ｖ相），…から構成されている。
【０１１０】
この場合、第２層目のコイルＣＶ１，ＣＷ１，ＣＵ１は、機械的な位相はそれぞれπ／３、５π／３、π／２であるため、電流の方向を逆にすることによってＶ相、Ｗ相、Ｕ相となる。従って、固定子ユニット１９８ＡのＵ相、Ｗ相、Ｖ相のコイル群は、図８の駆動系と同様の回路で駆動することができる。
また、図１３（Ｄ）に示すように、下方の固定子ユニット１９８Ｂは、上方の固定子ユニット１９８Ａと同様の３層のコイルユニットより構成されており、これらのコイルユニットもＵ相、Ｖ相、Ｗ相のコイル群に分けることができる。従って、固定子ユニット１９８Ｂは、図９の駆動系と同様の回路で駆動することができる。
【０１１１】
また、上記の実施形態では、３相のリニアモータが使用されているが、２相又は４相等のリニアモータも使用することができる。更に、上記の実施形態では、レチクルステージＲＳＴを駆動するためにムービングマグネット方式のリニアモータが使用されているが、ムービングコイル方式のリニアモータも使用することができる。
【０１１２】
次に、本発明の第２の実施形態につき図１４を参照して説明する。本例は、図８の制御部９０Ａ中に電圧計を備えたものであり、図１４において図８に対応する部分には同一符号を付してその詳細説明を省略する。
図１４は、本例の第２のＹ軸リニアモータ７８Ａ（図５参照）の固定子ユニット１３８Ａの駆動系を示し、この図１４において、図８のマニュアル方式の切替スイッチ１９２Ｕ，１９２Ｗ，１９２Ｖの代わりに、主制御装置７０からの制御信号によって切り替え可能なスイッチング素子１９５Ｕ，１９５Ｗ，１９５Ｖが設けられている。また、制御部９０Ａ内には電圧計１９４が設置され、スイッチング素子１９５Ｕ，１９５Ｗ，１９５Ｖのそれぞれの一つの出力部が電圧計１９４の計測信号入力部に接続されている。電圧計１９４は、３つの計測信号入力部の電圧を並列に所定のサンプリングレートで取り込み、計測データをデジタルデータとしてレチクルステージ制御部９０Ｒに供給する機能を備えている。これ以外の構成は図８の例と同様である。
【０１１３】
図１４の実施形態では、Ｙ軸リニアモータ７８Ａを駆動する際には、スイッチング素子１９５Ｕ，１９５Ｗ，１９５Ｖを、Ｕ相、Ｗ相、Ｖ相のアンプ１９１Ｕ，１９１Ｗ，１９１Ｖの出力部がそれぞれ出力端子１９７Ｕ，１９７Ｗ，１９７Ｖに接続されるように設定する。一方、固定子ユニット１３８Ａの３相のコイル群の逆起電力を計測する際には、スイッチング素子１９５Ｕ，１９５Ｗ，１９５Ｖを、出力端子１９７Ｕ，１９７Ｗ，１９７Ｖがそれぞれ電圧計１９４の計測信号入力部に接続されるように設定する。これによって、例えば露光工程の途中であっても、自動的に固定子ユニット１３８Ａの３相のコイル群の逆起電力を計測して、推力定数の補正を行うことができる。
【０１１４】
このように本例では、最初から電圧計１９４が制御部９０Ａに組み込まれているため、特別な工具無しで、いつでも推力定数を測定でき、例えば、長期的なリニアモータの経時変化をモニタしたい場合に有効である。また、例えば露光中に推力異常やその他の異常が検出された場合、即座に、コイルの絶縁破壊、断線等のリニアモータの故障の有無が検出できるという利点もある。
【０１１５】
次に、本発明の第３の実施形態につき図１５を参照して説明する。本例は、所定のガイドに沿ってステージを駆動する場合に本発明を適用したものである。
図１５は、本例のステージ装置の要部を示す斜視図であり、この図１５において、定盤よりなるベース３０１の表面の直交する２方向にＸ軸及びＹ軸を取って説明する。ベース３０１上にＹ方向に沿ってＹ軸ガイド３０２が設置され、Ｙ軸ガイド３０２に沿ってＹ方向に移動自在にスライダ３０４が配置され、スライダ３０４にテーブル３０３が固定され、テーブル３０３の中央部にホルダ３０５を介してレチクルなどの移動対象物３０６が保持されている。ホルダ３０５の中央部及びテーブル３０３の対応する部分には、例えば移動対象物３０６を透過した光を通すための開口が形成されており、ベース３０１にもその光を通すための開口３０１ａが形成されている。
【０１１６】
また、Ｙ軸ガイド３０２をＸ方向に挟むように、それぞれＹ軸に平行に磁石ユニットを含む固定子３０８Ａ及び３０８Ｂが配置され、固定子３０８Ａ及び３０８Ｂは不図示の保持部材によってベース３０１に固定されている。そして、固定子３０８Ａ及び３０８Ｂにはそれぞれコイルユニットを含む可動子３０７Ａ及び３０７ＢがＹ方向に相対移動自在に連結され、可動子３０７Ａ及び３０７Ｂはテーブル３０３の底面に固定されている。この場合、可動子３０７Ａ及び固定子３０８Ａより第１のＹ軸リニアモータ３０９Ａが構成され、可動子３０７Ｂ及び固定子３０８Ｂより第２のＹ軸リニアモータ３０９Ｂが構成されている。更に、ホルダ３０５に設けられた移動鏡３１０に外部のレーザ干渉計３１１から計測用のレーザビームを照射することによって、テーブル３０３のＹ方向の位置が計測され、この計測値に基づいてＹ軸リニアモータ３０９Ａ，３０９Ｂが駆動される。
【０１１７】
本例のテーブル３０３（第２部材）は、ベース３０１（第１部材）に対してＹ軸ガイド３０２に沿ってＹ方向に１自由度で移動すると共に、ベース３０１に対してテーブル３０３をＹ方向に駆動するための駆動装置として、Ｘ方向に離れた２軸のＹ軸リニアモータ３０９Ａ及び３０９Ｂが設けられている。従って、移動の自由度に比べて駆動装置の軸数が１だけ多いため、例えば第１のＹ軸リニアモータ３０９Ａのみでテーブル３０３をＹ方向に駆動して、第２のＹ軸リニアモータ３０９Ｂは推力を発生しない状態に設定して、可動子３０７Ｂ内のコイル群で発生する逆起電力を計測することができる。これによって第２のＹ軸リニアモータ３０９Ｂの推力定数を補正することができる。同様に、第２のＹ軸リニアモータ３０９Ｂのみでテーブル３０３を駆動して、第１のＹ軸リニアモータ３０９Ａの可動子３０７Ａ内のコイル群で発生する逆起電力を計測することで、第１のＹ軸リニアモータ３０９Ａの推力定数を補正することができる。
【０１１８】
本例では、片側のリニアモータ（３０９Ａ又は３０９Ｂ）だけでもテーブル３０３のＹ方向への移動は可能であるが、位置決め性能や等速性は２軸のＹ軸リニアモータ３０９Ａ，３０９Ｂで動かした場合に比べて劣る。しかし、ステージ装置としての最高速度で動かさなくても、逆起電力測定には何ら問題がないため、異常な機械共振やその他不具合を発生させない程度にステージ速度を遅くすることによって、コイルに発生する逆起電力は測定でき、第１の実施形態と同様に推力定数を補正することができる。これにより、位置決め性能や等速性を向上させることができる。
【０１１９】
なお、上記の実施の形態の投影露光装置は、複数のレンズから構成される照明光学系、投影光学系を露光装置本体に組み込み光学調整をして、多数の機械部品からなるレチクルステージやウエハステージを露光装置本体に取り付けて配線や配管を接続し、更に総合調整（電気調整、動作確認等）をすることにより製造することができる。なお、その露光装置の製造は温度及びクリーン度等が管理されたクリーンルームで行うことが望ましい。
【０１２０】
また、上記の実施の形態の投影露光装置を用いて半導体デバイスを製造する場合、この半導体デバイスは、デバイスの機能・性能設計を行うステップ、このステップに基づいてレチクルを製造するステップ、シリコン材料からウエハを形成するステップ、上記の実施の形態の投影露光装置によりアライメントを行ってレチクルのパターンをウエハに露光するステップ、エッチング等の回路パターンを形成するステップ、デバイス組み立てステップ（ダイシング工程、ボンディング工程、パッケージ工程を含む）、及び検査ステップ等を経て製造される。
【０１２１】
なお、本発明は、露光装置のレチクルステージのみならず、ウエハステージにも適用することができる。また、本発明は、走査露光型の露光装置のみならず、一括露光型の露光装置のレチクルステージやウエハステージにも適用することができる。また、本発明の露光装置の用途としては半導体デバイス製造用の露光装置に限定されることなく、例えば、角型のガラスプレートに形成される液晶表示素子、若しくはプラズマディスプレイ等のディスプレイ装置用の露光装置や、撮像素子（ＣＣＤ等）、マイクロマシーン、薄膜磁気ヘッド、及びＤＮＡチップ等の各種デバイスを製造するための露光装置にも広く適用できる。更に、本発明は、各種デバイスのマスクパターンが形成されたマスク（フォトマスク、レチクル等）をフォトリソグフィ工程を用いて製造する際の、露光工程（露光装置）にも適用することができる。
【０１２２】
なお、本発明は上述の実施の形態に限定されず、本発明の要旨を逸脱しない範囲で種々の構成を取り得ることは勿論である。
【０１２３】
【発明の効果】
本発明によれば、推力を発生していない駆動装置の起電力を検出しているため、その駆動装置の駆動性能を向上することができ、移動対象の部材を高精度に駆動することができる。
また、本発明を露光装置に適用することによって、各種デバイスを高精度に製造することができる。
【図面の簡単な説明】
【図１】本発明の第１の実施形態の投影露光装置の概略構成を示す一部を切り欠いた図である。
【図２】図１の枠状部材１８及びレチクルステージＲＳＴの構成を示す斜視図である。
【図３】図１のレチクルステージＲＳＴ、枠状部材１８、及びレチクルベース１６の構成を示す分解斜視図である。
【図４】（Ａ）は図１のレチクルステージＲＳＴを示す斜視図、（Ｂ）はレチクルステージＲＳＴをＹ方向に見た断面図である。
【図５】図１の照明系側プレート１４、レチクルステージＲＳＴ、及びレチクルベース１６をＹ方向に見た断面図である。
【図６】図１の照明系側プレート１４、レチクルステージＲＳＴ、及びレチクルベース１６の要部をＸ方向に見た断面図である。
【図７】図５のＹ軸リニアモータ７８Ａ，７８Ｂの固定子ユニット１３８Ａ，１３８Ｂ及び可動子ユニット２８Ａ，２８Ｂの構成を示す図である。
【図８】図７の一方の固定子ユニット１３８Ａの駆動系を示す図である。
【図９】図７の他方の固定子ユニット１３８Ｂの駆動系を示す図である。
【図１０】図７のＹ軸リニアモータ７８Ａの推力定数の一例を示す図である。
【図１１】図７のＹ軸リニアモータ７８Ｂの逆起電力定数の一例を示す図である。
【図１２】本発明の第１の実施形態でリニアモータの推力定数を補正するための動作の一例を示すフローチャートである。
【図１３】図７のＹ軸リニアモータ７８Ａ，７８Ｂの固定子ユニットの変形例を示す図である。
【図１４】本発明の第２の実施形態のリニアモータの固定子ユニット１３８Ａの駆動系を示す図である。
【図１５】本発明の第３の実施形態のステージ装置の要部を示す斜視図である。
【符号の説明】
ＲＳＴ…レチクルステージ、Ｒ…レチクル、１６…レチクルベース、１８…枠状部材、７６Ａ，７８Ａ，７６Ｂ，７８Ｂ…Ｙ軸リニアモータ、１３６Ａ，１３８Ａ，１３６Ｂ，１３８Ｂ…固定子ユニット、２６Ａ，２８Ａ，２６Ｂ，２８Ｂ…可動子ユニット、６９ＹＡ，６９ＹＢ…Ｙ軸レーザ干渉計、９０Ｒ…レチクルステージ制御部、９０Ａ，９０Ｂ…制御部、１９０…電流値設定部、１９２Ｕ，１９２Ｗ，１９２Ｖ…切替スイッチ、１９３Ｕ，１９３Ｗ，１９３Ｖ…電圧計測端子、１９４…電圧計、１９６Ｕ，１９６Ｗ，１９６Ｖ…コイル群[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a stage device for driving a second member relative to a first member, for example, photolithography for manufacturing a device such as a semiconductor device, an image sensor, a liquid crystal display device, or a thin film magnetic head. It is suitable for use in a mask stage or a substrate stage of an exposure apparatus used for transferring a mask pattern onto a substrate during the process.
[0002]
[Prior art]
For example, when manufacturing a semiconductor device, in order to transfer a reticle pattern as a mask to each shot area of a wafer (or a glass plate or the like) coated with a photoresist as a substrate, a batch exposure method or a scanning exposure method is used. An exposure apparatus is used. The former exposure apparatus of the batch exposure system mainly positions wafers and reticles with high accuracy, and the latter of the scanning exposure system mainly improves uniformity of the reticle and wafer during scanning exposure. In order to maintain accuracy, a reticle stage and a wafer stage are provided. In the past, rotary motors were used as drive actuators for these stages, but recently, linear motors have been used, which have substantially no friction, and therefore reduce the disturbance applied to the stage, and can even eliminate them. Is often done.
[0003]
A linear motor has a mover and a stator as a basic configuration.For example, in a moving magnet type linear motor, magnets are arranged at a predetermined pitch on the mover, and coils are arranged on the stator according to the arrangement of the magnets. Are located. Usually, when the stroke is long, a three-phase linear motor is used, and the current of each phase coil is set by the position (relative position) of the mover (magnet) with respect to the stator (three-phase coil).
[0004]
In this case, by appropriately adjusting the width and pitch of the magnet, the magnetic flux density linked to the coil has a substantially sinusoidal shape according to the position, and the pitch of the magnetic flux density is considered as a sine wave cycle as an example. The pitch of the three-phase coil is ／ of the pitch of the magnetic flux density (for example, see Patent Document 1). As another example, the pitch of the coils can be set to 1/6 of the pitch of the magnetic flux density, and in any case, there is a predetermined relationship between the pitch of the magnets and the pitch of the coils. .
[0005]
The thrust generated by the linear motor follows Fleming's left-hand rule, and its magnitude is proportional to the magnetic flux density and proportional to the current. Further, when the position of the mover changes, the magnetic flux density linked to the coil changes. Therefore, if a constant current continues to flow through the coil, the thrust changes depending on the position of the mover. In this case, the thrust generated by the coils of each phase can be obtained by multiplying the thrust constant (thrust generated per unit current) of the coils of each phase by the current. The thrust constant is a function of the position of the mover and is approximately a sinusoidal function of that position. In the case of a linear motor used for a stage, it is required that a constant thrust can be obtained at any position. Therefore, in a three-phase linear motor, the phases of the currents flowing through the three-phase coils are shifted by 120 °, and The sum of the thrusts generated by the coils of each phase is made constant.
[0006]
That is, when each coil is at the peak position of the magnetic flux density, the peak of the current flowing through the coil is made to come, and when the magnetic flux density becomes 0, the current is also made 0, and at the intermediate position between them, The current is changed sinusoidally. At this time, the magnetic flux density B can be approximated by the following equation.
B = B ₀ sin (2πX / P) (1)
Where B ₀ Is the peak value of the magnetic flux density, and X is the coordinate value along the magnet. Further, when the relative position of the U-phase (0π) coil as the stator with respect to the mover (magnet) is x, the current peak value is I ₀ Then, the currents Iu, Iv, Iw flowing through the U-phase, V-phase (-2π / 3 or + 4π / 3), and W-phase (+ 2π / 3) coils are as follows, respectively.
[0007]
Iu = I ₀ sin (2πx / P) (2)
Iv = I ₀ sin (2πx / P−2π / 3) (3)
Iw = I ₀ sin (2πx / P + 2π / 3) (4)
If the thrusts generated by the U-phase, V-phase, and W-phase coils are fu, fv, and fw, a basic formula of electromagnetic force F = B × I × L (F: force, I: current, L: From the length of the coil), the following equation is obtained. The number of turns (number of turns) of the coil is omitted for simplification.
[0008]
fu = B ₀ sin (2πx / P) × I ₀ sin (2πx / P) (5)
fv = B ₀ sin (2πx / P−2π / 3) × I ₀ sin (2πx / P−2π / 3) (6)
fw = B ₀ sin (2πx / P + 2π / 3) × I ₀ sin (2πx / P + 2π / 3) (7)
Therefore, the thrust Ftotal of the entire linear motor is as follows.
[0009]
Ftotal = fu + fv + fw = 1.5 × B ₀ × I ₀ … (8)
That is, by changing the current according to the position of the mover as described above, a constant thrust can be obtained regardless of the position of the mover.
[0010]
[Patent Document 1]
JP 2001-190088 A
[0011]
[Problems to be solved by the invention]
As described above, in the three-phase linear motor, if the arrangement pitch of the magnets, the positional relationship between the magnets and the coil, and the like are as designed, the current flows through the coils of each phase based on, for example, a thrust constant obtained by calculation in advance. By controlling the current, a constant thrust can be obtained regardless of the position of the mover. However, in practice, due to the processing error of the motor parts and the assembly error of the stage and the linear motor, the arrangement pitch of the magnets, the linear density of the coils (and the current density), and the positional relationship between the magnets and the coils are to some extent. , And an error remains in the thrust constant of the coil of each phase. Variations in the magnetic flux density of each magnet also cause an error in the thrust constant.
[0012]
Such an error in the thrust constant causes a change in the thrust.For example, when the stage is accelerated or decelerated, the thrust may fluctuate when driving the mover with a constant thrust regardless of the position of the mover. Become.
In order to meet the demand for higher integration of semiconductor devices and further improvement of throughput, exposure apparatuses are required to have higher precision and higher speed of stages. Therefore, it is desired that variations in performance of the linear motor, such as thrust fluctuations, be minimized.
[0013]
In view of the above, an object of the present invention is to provide a stage technology capable of driving a member to be moved with high accuracy.
Another object of the present invention is to provide an exposure technique and a device manufacturing technique that can transfer a mask pattern onto a substrate with high accuracy by using the stage technique.
[0014]
[Means for Solving the Problems]
A stage device according to the present invention is a stage device that relatively drives a second member (RST) in at least one direction with respect to a first member (18). A plurality of driving devices (78A, 76A, 78B, 76B) for driving the second member relative to the first member, and some of the driving devices (78A, 76A) among the plurality of driving devices are provided. When the second member is driven in the one direction by the generated thrust, the electromotive force generated in the other driving devices (78B, 76B) which do not generate the thrust is detected. And a detection device (192U to 192W, 193U to 193W, 194).
[0015]
According to the present invention, when the second member is driven with respect to the first member, another driving device that does not generate thrust (hereinafter, referred to as a “tested driving device”), for example, according to Fleming's right hand rule. ) Generates an electromotive force (induced electromotive force). Therefore, by detecting the electromotive force, the thrust constant (thrust generated per unit current) of the test drive device can be obtained. Then, by driving the other driving device using the thrust constant obtained in this manner, the first member can be driven with high accuracy with respect to the first member with the target thrust. .
[0016]
In this case, assuming that the degree of freedom of driving the second member relative to the first member is N (N is an integer of 1 or more), the second member can be moved relative to the first member with N degrees of freedom. It is desirable that the number of the plurality of driving devices to be dynamically driven is at least (N + 1). Accordingly, when the second member is driven with the degree of freedom N with respect to the first member, at least one axis of the driving device does not need to generate a thrust, so that the electromotive force of the driving device can be detected. Can be.
[0017]
Further, as an example, the plurality of driving devices that relatively drive the second member in the one direction with respect to the first member include a first pair of driving devices arranged in a direction intersecting the one direction. A driving device (78A, 76A); and a second pair of driving devices (78B, 76B) arranged opposite to the first pair of driving devices, and the detecting device includes a driving device (78A, 76B). Detecting the electromotive force generated in the second pair of driving devices when the second member is driven in one direction with respect to the first member via the one pair of driving devices. is there.
[0018]
In this case, even if the first member and the second member relatively move in a guideless manner, the second member can be stably driven only by the first pair of driving devices. Therefore, the electromotive force generated in the second pair of driving devices can be detected with high accuracy.
Further, based on a position measuring device (69YA, 69YB) for measuring the position of the second member, a moving speed of the second member obtained by the position measuring device, and an electromotive force detected by the detecting device, It is desirable to have a control device (90R) that corrects the thrust generated by other driving devices and controls the driving devices. By dividing the detected electromotive force by the moving speed of the second member, the thrust constants of the other driving devices can be easily obtained, and the other driving devices can be set high based on the obtained thrust constants. It can be driven with high accuracy.
[0019]
In addition, it is desirable that a part of the plurality of driving devices that generate thrust and the other driving device that does not generate thrust can be switched with each other. As a result, the electromotive force can be detected alternately by some of the driving devices and other driving devices. Therefore, the electromotive force of all the driving devices can be obtained, and based on this, all the driving devices can be driven with high accuracy.
[0020]
Further, the driving method of the stage device of the present invention is the driving method of any of the stage devices of the present invention, wherein the second member is driven by a thrust generated by a part of the plurality of driving devices. A first step (steps 201 and 202) of detecting an electromotive force generated in another of the plurality of driving devices that does not generate the thrust when the driving device is driven in one direction; A second step (step 203) of obtaining a correction value of the thrust generated by the other driving device based on the electromotive force detected in step (2), and using the correction value obtained in the second step, the other driving device A third step (step 207) of correcting the generated thrust and driving the second member.
[0021]
As a result, the second member can be driven with high accuracy with the target thrust.
An exposure apparatus according to the present invention illuminates a first object (R) with an exposure beam and exposes a second object (W) via the first object with the exposure beam. And any one of the stage devices of the present invention for driving at least one of the second object.
[0022]
Since the first object or the second object can be driven with high accuracy by the stage device of the present invention, high positioning accuracy can be obtained with the batch exposure type, and high uniform velocity can be obtained with the scanning exposure type. The pattern of the first object can be transferred onto the second object with high accuracy.
[0023]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. In the present embodiment, the present invention is applied to a stage device provided in a scanning exposure type projection exposure apparatus (scanning stepper) using a step-and-scan method.
[0024]
FIG. 1 shows a schematic configuration of a projection exposure apparatus 10 of the present embodiment. In FIG. 1, a Z axis is taken in parallel with an optical axis AX of a projection optical system PL provided in the projection exposure apparatus 10, and a Z axis is taken. The description will be made by taking a Y axis in a scanning direction of a reticle and a wafer (detailed later) at the time of scanning exposure in a vertical plane, and an X axis in a non-scanning direction orthogonal to the scanning direction.
The projection exposure apparatus 10 of this example drives the reticle R on which the circuit pattern is formed as a mask (first object) in the X direction, the Y direction, and the θz Reticle stage device 12 as a stage device that minutely drives in the direction (rotation direction around the Z axis), projection optical system PL, and wafer W that drives wafer W as a substrate (second object) in the XY plane in the XY plane. A stage WST and a control system for these are provided.
[0025]
The illumination optical system unit IOP includes an exposure light source and an illumination optical system, and uses a rectangular or arc-shaped illumination area IAR of a pattern surface of a reticle R defined by a field stop (reticle blind) disposed therein as an exposure beam. With a uniform illuminance distribution with the exposure light IL. An illumination system similar to the illumination optical system is disclosed in, for example, JP-A-6-349701. As the exposure light IL of this example, ArF excimer laser light (wavelength 193 nm) or F ₂ Vacuum ultraviolet light such as laser light (wavelength 157 nm) is used. It is also possible to use, as the exposure light IL, far ultraviolet light such as KrF excimer laser light (wavelength 248 nm), ultraviolet bright lines (g-line, i-line, etc.) from an ultra-high pressure mercury lamp.
[0026]
Next, the reticle stage device 12 is disposed below an illumination system side plate (cap plate) 14 as a plate having an annular mounting portion 101 connected to the lower end of the illumination optical system IOP in FIG. The illumination system side plate 14 is supported substantially horizontally by a support member (not shown), and a substantially central portion thereof is formed with a rectangular opening 14a serving as an optical path (path) of the exposure light IL.
[0027]
As can be seen from FIG. 1 and FIG. 2 which is a perspective view of the reticle stage device 12, the reticle stage device 12 is a reticle as a surface plate which is disposed substantially parallel to the illumination system side plate 14 with a predetermined space therebetween. A base 16, a reticle stage RST as a slider arranged between the reticle base 16 and the illumination system side plate 14, and an arrangement between the reticle base 16 and the illumination system side plate 14 surrounding the reticle stage RST. And a reticle stage drive system for driving the reticle stage RST.
[0028]
The reticle base 16 is supported substantially horizontally by a support member (not shown). As shown in FIG. 3, which is an exploded perspective view of FIG. 2, the reticle base 16 is formed of a substantially plate-shaped member, and a convex guide portion 16a is formed substantially at the center thereof. The upper surface (guide surface) of the guide portion 16a is finished to an extremely high flatness, and a rectangular opening 16b having a longitudinal direction in the X direction for allowing the exposure light IL to pass in the Z direction is provided substantially in the center of the guide portion 16a. Is formed. On the lower surface side of the reticle base 16, a projection optical system PL is arranged corresponding to the rectangular opening 16b, as shown in FIG.
[0029]
The reticle stage RST includes a reticle stage main body 22 having a special shape as shown in FIG. 4A, and various magnet units (described in detail later) fixed to the reticle stage main body 22. The reticle stage main body 22 has a substantially rectangular plate-like portion 24A viewed from above, a mirror portion 24B provided at an end of the plate-like portion 24A in the −X direction, and one side of the plate-like portion 24A in the Y direction. And a pair of extending portions 24C1, 24C2, 24D1, 24D2 respectively protruding from the other end in the Y direction.
[0030]
At a substantially central portion of the plate-like portion 24A, there is formed a stepped opening 22a having an opening formed at the center thereof for allowing the exposure light IL to pass therethrough. A plurality of (for example, three) reticle support members 34 that support the reticle R at a plurality of points (for example, three points) from below are provided in the (portion). In addition, a plurality of (for example, three) reticle fixing mechanisms 34P are provided in the plate-shaped portion 24A so as to sandwich and fix the reticle R corresponding to each of the reticle support members 34.
[0031]
The reticle R is supported by a plurality of supports in a state where the pattern surface (lower surface) of the reticle R substantially coincides with the neutral surface CT (the surface that does not expand and contract when receiving a bending moment) of the reticle stage body 22 (reticle stage RST). It is supported by a member 34 (see FIG. 4B). It should be noted that various chucks such as a vacuum chuck and an electrostatic chuck can be used instead of or together with the reticle support member 34 and the reticle fixing mechanism 34P.
[0032]
Further, as can be seen from FIGS. 4A and 4B, the mirror portion 24B has a substantially prismatic shape with the Y direction as a longitudinal direction, and a cross section for reducing the weight at the center thereof. A circular cavity CH is formed. An end surface in the −X direction of the mirror portion 24B is a reflecting surface 124m (see FIG. 5) that has been subjected to mirror finishing.
The reticle stage main body 22 including the plate-shaped portion 24A and the mirror portion 24B is integrally formed (for example, formed by cutting out one member). However, in this example, it is necessary to make the description easy to understand. Accordingly, an expression as if each part is a separate member is also used. Of course, any one of the above-described portions may be formed of another member, or all of the portions may be formed of separate members.
[0033]
In FIG. 4A, two recesses 24g1 and 24g2 are formed at an end of the plate-like portion 24A of the reticle stage main body 22 in the −Y direction, and each of the recesses 24g1 and 24g2 has a movable mirror. Retroreflectors 32A and 32B are provided. The four extended portions 24C1, 24C2, 24D1, 24D2 have a substantially plate-like shape, and each extended portion is provided with a reinforcing portion having a triangular cross section for improving strength. On the bottom surface of the reticle stage main body 22, a first differential exhaust gas static pressure bearing is formed over the entire area in the Y direction from the extending portion 24C1 to the extending portion 24D1, and is formed from the extending portion 24C2. A second differential exhaust type gas static pressure bearing is formed over the entire area in the Y direction up to 24D2.
[0034]
As shown in FIG. 6, which is a cross-sectional view of a part of the reticle stage device 12 of FIG. 1, the guide of the reticle base 16 from the first and second differential exhaust gas static pressure bearings on the bottom surface of the reticle stage main body 22. Due to the balance between the static pressure of the pressurized gas sprayed on the upper surface of the portion 16a and the weight of the entire reticle stage RST, the reticle stage RST is brought into non-contact with a clearance of about several μm above the upper surface of the guide portion 16a. Floating supported.
[0035]
Returning to FIG. 2, a substantially annular concave groove 83, 85 is formed on the upper surface of the frame member 18 in a double manner. A plurality of air supply ports (not shown) are formed in the inner concave groove (hereinafter, referred to as an “air supply groove”) 83, and an outer concave groove (hereinafter, referred to as an “exhaust groove”) is formed. A plurality of exhaust ports (not shown) are formed in the (callout) 85. An air supply port formed inside the air supply groove 83 is connected to a gas supply device (not shown) via a gas supply line and a gas supply tube (not shown). An exhaust port formed inside the exhaust groove 85 is connected to a vacuum pump (not shown) through an exhaust pipe and an exhaust pipe (not shown).
[0036]
In addition, an air supply groove and an exhaust groove (not shown) made of a substantially annular concave groove are formed on the bottom surface of the frame-shaped member 18 so as to correspond to the air supply groove 83 and the exhaust groove 85 on the upper surface. The air groove and the exhaust groove are also connected to a gas supply device and a vacuum pump (not shown), respectively. Including the air supply groove and the exhaust groove, a differential exhaust gas static pressure bearing for supporting the frame-shaped member 18 on the upper surface of the reticle base 16 substantially is configured.
[0037]
That is, when the gas supply device and the vacuum pump are in the operating state, pressurized gas is blown from the air supply groove (not shown) on the bottom surface of the frame-shaped member 18 onto the upper surface of the reticle base 16, and the blown gas is blown. The self-weight of the frame member 18 is supported by the static pressure of the pressurized gas, and the frame member 18 is levitated and supported on the upper surface of the reticle base 16 via a clearance of about several μm.
[0038]
Similarly, including a supply groove 83 and an exhaust groove 85 on the upper surface of the frame member 18, a differentially exhausted gas that substantially maintains the clearance between the frame member 18 and the illumination system side plate 14. A hydrostatic bearing is configured.
That is, when the gas supply device and the vacuum pump are in the operating state, pressurized gas is blown from the air supply groove 83 formed on the upper surface of the frame-shaped member 18 to the lower surface of the illumination system side plate 14, A predetermined clearance is maintained between the frame member 18 and the illumination system side plate 14 by the balance between the static pressure of the applied pressurized gas and the vacuum suction force.
[0039]
Next, as shown in FIG. 2, the reticle stage drive system includes a first drive mechanism that drives the reticle stage RST in the Y direction and minutely drives the reticle stage RST in the θz direction (a rotation direction around the Z axis), and a reticle stage RST. And a second drive mechanism that minutely drives the X-ray in the X direction. The former first drive mechanism includes a pair of Y-axis linear guides 36 and 38 laid in the Y direction inside the frame member 18, and the latter second drive mechanism includes the frame member 18. And a stator unit 40 extending in the Y direction on the −X direction side of the Y axis linear guide 38 on the + X direction side.
[0040]
As shown in an exploded perspective view of FIG. 3, the one Y-axis linear guide 36 includes stator units 136A and 136B in which a pair of coil units each having a longitudinal direction in the Y direction are disposed, and these stator units 136A and 136B. A pair of fixing members 152 for holding 136A and 136B at one end and the other end in the Y direction (longitudinal direction) are provided. In this case, the stator units 136A and 136B are held by the pair of fixing members 152 so as to face each other at a predetermined interval in the Z direction (vertical direction) and to be parallel to the XY plane. Each of the pair of fixing members 152 is fixed to the inner wall surface of the frame member 18 described above.
[0041]
Each of the stator units 136A and 136B has a frame made of a nonmagnetic material having a rectangular cross section (rectangular shape), as can be seen from FIG. 3 and FIG. 5 which is a cross sectional view near the reticle stage main body 22 in FIG. Inside, a plurality of coils are arranged at predetermined intervals in the Y direction.
The Y-axis linear guide 38 on the + X direction side is configured similarly to the one Y-axis linear guide 36 described above. That is, the Y-axis linear guide 38 maintains the stator units 138A and 138B in which a pair of upper and lower coil units each having a longitudinal direction in the Y direction are arranged, and the stator units 138A and 138B at a predetermined interval in the Z direction. And a pair of fixing members 154 that are fixed at both ends in this state. Each of the pair of fixing members 154 is fixed to the inner wall surface of the frame-shaped member 18 described above. The stator units 138A and 138B have the same configuration as the above-described stator units 136A and 136B (see FIG. 5).
[0042]
Further, between upper stator units 136A and 138A and lower stator units 136B and 138B, a reticle stage RST is provided via predetermined clearances as shown in FIG. I have. In this case, opposing stator units 136A and 136B, respectively, embed mover units 26A and 26B in each of which a pair of magnet units (magnetic pole units) are disposed on the upper and lower surfaces of reticle stage RST, respectively. Opposed to units 138A and 138B, mover units 28A and 28B in each of which a pair of magnet units are arranged are embedded in the upper and lower surfaces of reticle stage RST. In this example, as the magnet units of the mover units 26A, 26B and 28A, 28B, units in which a plurality of permanent magnets each generating a magnetic field in the Z direction are arranged in the Y direction while reversing the polarity at a predetermined pitch are used. However, an electromagnet or the like can be used instead of the permanent magnet.
[0043]
As shown in FIG. 4B, each of the mover units 26A and 26B has a neutral position of the reticle stage main body 22 on the −X direction side of the stepped opening 22a of the plate-like portion 24A of the reticle stage main body 22 described above. They are arranged symmetrically with respect to the plane CT in the concave portions 24e1 and 24e2 formed on the upper and lower surfaces, respectively. In this case, the stator units 136A and 136B of FIG. 5 are located at substantially symmetric positions with respect to the neutral plane CT. Each of the pair of mover units 26A and 26B includes a magnetic member and a plurality of magnets arranged on the surface of the magnetic member at predetermined intervals along the Y direction. The plurality of magnets have opposite polarities between adjacent magnets. Therefore, an alternating magnetic field is formed along the Y direction in the space above the mover unit 26A and in the space below the mover unit 26B.
[0044]
Similarly, as shown in FIG. 4 (B), each of the pair of mover units 28A and 28B is provided on the + X direction side of the stepped opening 22a of the plate-shaped portion 24A of the reticle stage main body 22 described above. The main body 22 is disposed symmetrically with respect to the neutral plane CT in the concave portions 24f1 and 24f2 formed on the upper and lower surfaces, respectively. In addition, the pair of mover units 28A and 28B move with respect to a straight line parallel to the Z axis that passes through the center position of the stepped opening 22a in the X direction (substantially coincides with the position of the center of gravity of the reticle stage RST in the X direction). 26A and 26B are arranged almost symmetrically. Further, the first stator units 138A and 138B of FIG. 5 are located at substantially symmetric positions with respect to the neutral plane CT.
[0045]
Each of the pair of mover units 28A and 28B includes a magnetic member and a plurality of magnets arranged on the surface of the magnetic member at predetermined intervals along the Y direction. The plurality of magnets have opposite polarities between adjacent magnets. Accordingly, an alternating magnetic field is formed along the Y direction also in the space above the mover unit 28A and the space below the mover unit 28B.
[0046]
In this example, FIG. 5 shows the stator units 136A and 138A on the upper side of the Y-axis linear guides 36 and 38, and the mover units 26A and 28A that are arranged on the reticle stage main body 22 side. Thus, the first Y-axis linear motor 76A and the second Y-axis linear motor 78A are configured. Then, as shown in FIG. 5, a third Y-axis is formed from the lower stator units 136B and 138B of the Y-axis linear guides 36 and 38 and the corresponding mover units 26B and 28B on the reticle stage main body 22 side. A linear motor 76B and a fourth Y-axis linear motor 78B are configured. The first drive mechanism described above is constituted by first, second, third, and fourth Y-axis linear motors 76A, 78A, 76B, 78B as single-axis drive devices. The four-axis Y-axis linear motors 76A, 78A, 76B, 78B of the present example are of a moving magnet type, and it is not necessary to connect a wire to a member moving with a wide stroke, so that the moving speed can be increased. .
[0047]
For example, in the first Y-axis linear motor 76A, when a current is supplied in the X direction to the coil in the stator unit 136A as the stator, the current flowing through the coil and the current in the mover unit 26A as the mover are supplied. Due to the electromagnetic interaction between the magnet and the magnetic field generated in the Z direction, an electromagnetic force (Lorentz force) in the Y direction is generated in the coil in the stator unit 136A according to Fleming's left-hand rule. Then, the reaction (reaction force) of the electromagnetic force becomes a thrust for driving the mover unit 26A in the Y direction relative to the stator unit 136A. Similarly, the second Y-axis linear motor 78A of FIG. 5 generates a thrust for driving the mover unit 28A in the Y direction relative to the stator unit 138A. Further, the third and fourth Y-axis linear motors 76B and 78B generate thrusts for driving the mover units 26B and 28B in the Y direction relative to the stator units 136B and 138B, respectively.
[0048]
As described above, the stator (stator units 136A, 138A, 136B, 138B) and the mover (mover units 26A, 28A, 26B, 28B) perform physical interaction such as electromagnetic interaction to drive force. Is generated, it can be said that the stator and the mover "cooperate" to generate a driving force. Further, actually, the stator slightly moves in a direction opposite to the mover due to the electromagnetic force (action). Therefore, in this specification, a member having a larger relative movement amount is referred to as a mover or a mover unit, and a member having a smaller relative movement amount is referred to as a stator or a stator unit.
[0049]
In this case, the stator units 136A, 138A, 136B, 138B of the first, second, third, and fourth Y-axis linear motors 76A, 78A, 76B, 78B are respectively Y-axis linear guides 36, 38 in FIG. The mover units 26A, 28A, 26B, 28B are respectively fixed to a reticle stage RST (reticle stage main body 22) as a second member in FIG. 2 via a frame member 18 as a first member. . Further, the first and second Y-axis linear motors 76A and 78A are arranged symmetrically apart from each other in the X direction so as to sandwich the reticle R, and move the reticle stage RST relatively to the frame member 18. Drive in the Y direction. Further, the third and fourth Y-axis linear motors 76B and 78B are disposed so as to face the first and second Y-axis linear motors 76A and 78A, respectively, and relatively to the frame member 18. The reticle stage RST is driven in the Y direction. Accordingly, the first and second Y-axis linear motors 76A and 78A correspond to a first pair of driving devices, and the third and fourth Y-axis linear motors 76B and 78B correspond to a second pair of driving devices. It corresponds to.
[0050]
In this example, the frame-shaped member 18 in which the Y-axis linear guides 36 and 38 of FIG. 2 are fixed inside is provided between the reticle base 16 on the bottom side and the illumination system side plate 14 on the top side via a gas bearing. Supported without contact. Therefore, when reticle stage RST is driven in the Y direction by Y-axis linear motors 76A, 78A, 76B, 78B, frame member 18 slightly moves in the opposite direction so as to cancel the reaction force. This suppresses the occurrence of vibration when driving reticle stage RST. However, since the mass of the frame member 18 is considerably larger than the mass of the reticle stage RST, the amount of movement of the frame member 18 is small.
[0051]
In this example, normally, in FIG. 5, the first and third Y-axis linear motors 76A and 76B on the −X direction side are driven so as to generate the same thrust in the Y direction in synchronization. Similarly, the second and fourth Y-axis linear motors 78A and 78B on the + X direction side are also driven so as to synchronously generate the same thrust in the Y direction. When the reticle stage RST (reticle R) is driven at a constant speed in the Y direction, the first and third Y-axis linear motors 76A and 76B and the second and fourth Y-axis linear motors 78A and 78A are driven. Further, the reticle stage RST is driven in the Y direction with respect to the frame member 18 with substantially the same thrust in synchronism with 78B. When it is necessary to correct the rotation angle θz (yaw) of the reticle stage RST, the thrust generated by the first and third Y-axis linear motors 76A and 76B and the second and fourth Y-axis linear motors The ratio of the magnitude to the thrust generated by the motors 78A and 78B is controlled.
[0052]
In the case of this example, as shown in FIG. 4B, the mover units 26A and 26B and the mover units 28A and 28B are respectively symmetrically arranged with respect to the neutral plane CT of the reticle stage RST. The stator units 136A and 136B and the stator units 138A and 138B of FIG. 5 corresponding to the mover units are also arranged vertically symmetrically with respect to the neutral plane CT. For this reason, currents corresponding to the coils of the stator units 136A, 136B, 138A, 138B are respectively supplied, and the same driving force is applied to the mover units 26A, 26B, 28A, 28B, whereby the reticle stage RST A driving force in the Y direction (a resultant force of the driving forces of the mover units 26A and 26B and a resultant force of the driving forces of the mover units 28A and 28B) is applied to two points on the neutral plane CT (see FIG. 4B). Can be done. As a result, the pitching moment does not act on reticle stage RST as much as possible.
[0053]
Furthermore, the mover units 26A and 26B and the mover units 28A and 28B are also arranged substantially symmetrically with respect to the X direction with respect to the position near the center of gravity of the reticle stage RST. Therefore, the above-described driving force in the Y direction is applied at two places equidistant from the center of gravity of reticle stage RST in the X direction. By generating the same force at these two places, Y is generated near the center of gravity of reticle stage RST. It is possible to apply the resultant of the driving forces in the directions. Therefore, for example, when the reticle stage main body 22 is driven linearly in the Y direction, the yaw moment does not act on the reticle stage RST as much as possible.
[0054]
In this example, as will be described later, for example, at the time of assembling adjustment or maintenance of the projection exposure apparatus, the first and second Y-axis linear motors 76A and 78A (first pair of driving devices) are used. When the reticle stage RST is driven in the Y direction, the coils of the stator units 136B and 138B are driven on the third and fourth Y-axis linear motors 76B and 78B (second pair of driving devices). It is configured such that predetermined drive information can be detected separately from the source. Further, by switching between the first and second Y-axis linear motors 76A and 78A and the third and fourth Y-axis linear motors 76B and 78B, the third and fourth Y-axis linear motors 76B and 78B ( When the reticle stage RST is driven in the Y direction via the first pair of driving devices, the first and second Y-axis linear motors 76A and 78A (the first pair of driving devices) side. The coils of the stator units 136A and 138A are separated from the drive source so that predetermined drive information can be detected.
[0055]
Next, as shown in FIG. 3, the stator unit 40 on the second drive mechanism side includes a pair of coil units 140A and 140B having a longitudinal direction in the Y direction, and these coil units 140A and 140B. A pair of fixing members 156 that are held at one end and the other end in the Y direction (longitudinal direction) are provided. In this case, the coil units 140A and 140B are held by the pair of fixing members 156 so as to face each other at a predetermined interval in the Z direction (vertical direction) and to be parallel to the XY plane. Each of the pair of fixing members 156 is fixed to the inner wall surface of the frame member 18 described above.
[0056]
As can be seen from FIG. 5, each of the coil units 140A and 140B has a frame made of a nonmagnetic material having a rectangular cross section (rectangle), and a coil is disposed inside the frame. As shown in FIG. 5, between the coil units 140A and 140B, a plate having a rectangular (rectangular) cross section as a movable element fixed to an end of the reticle stage RST in the + X direction via a predetermined clearance. A permanent magnet 30 that generates a magnetic field in the Z direction is disposed. Instead of the permanent magnet 30, a magnet unit including a magnetic member and a pair of flat permanent magnets fixed to upper and lower surfaces thereof may be used.
[0057]
In this case, the permanent magnet 30 and the coil units 140A and 140B have a substantially symmetric shape and arrangement with respect to the neutral plane CT (see FIGS. 4B and 5). Therefore, due to the electromagnetic interaction between the magnetic field in the Z direction formed by the permanent magnet 30 and the current flowing in the Y direction through the coils constituting the coil units 140A and 140B, the coils are applied in the X direction according to Fleming's left-hand rule. The electromagnetic force (Lorentz force) is generated, and the reaction force of this electromagnetic force becomes a thrust for driving the permanent magnet 30 (reticle stage RST) in the X direction. Also in this case, the frame member 18 slightly moves in the opposite direction so as to cancel the reaction force when driving the reticle stage RST in the X direction. Accordingly, generation of vibration when driving reticle stage RST in the X direction is also suppressed.
[0058]
In this case, the same current is supplied to the coils constituting the coil units 140A and 140B, thereby applying a driving force in the X direction to a position on the neutral plane CT (see FIG. 4B) of the reticle stage RST. As a result, the rolling moment does not act on the reticle stage RST as much as possible.
[0059]
As described above, the coil units 140A and 140B and the permanent magnet 30 constitute a moving magnet type X-axis voice coil motor 79 capable of minutely driving the reticle stage RST in the X direction. The X-axis voice coil motor 79 as the driving device constitutes a second driving mechanism.
As a result, the reticle stage RST of this example in FIG. 2 is supported so as to be relatively displaceable with respect to the frame member 18 in three degrees of freedom in the X, Y, and θz directions in a guideless manner. In order to drive the reticle stage RST relatively to the frame member 18, four-axis Y-axis linear motors 76A, 78A, 76B, 78B for generating a thrust in the Y direction and a one-axis for generating a thrust in the X direction. And a 5-axis driving device including the X-axis voice coil motor 79 described above. That is, the number of the plurality of driving devices that drive the reticle stage RST is increased by two with respect to the degree of freedom of movement of the reticle stage RST (= 3). Thereby, reticle stage RST can be driven in at least one direction even when a predetermined driving device among the plurality of driving devices is not driven, as will be described later.
[0060]
In this example, as shown in FIG. 3, movers 60A, 60B, and 60C each including a magnet unit that generates a magnetic field in the Z direction are provided on the side surfaces in the + X direction and the + Y direction of the frame member 18 described above. Is provided. Corresponding to these movers 60A, 60B, 60C, reticle base 16 is provided with stators 62A, 62B including coils for flowing current in the Y direction and currents in the X direction via support bases 64A, 64B, 64C. A stator 62C including a flowing coil is provided. That is, the mover 60A and the stator 62A and the mover 60B and the stator 62B constitute a moving magnet type voice coil motor for the X-direction drive trim motor. The mover 60C and the stator 62C constitute a Y-direction drive trim motor composed of a moving magnet type voice coil motor. By using these three trim motors, it is possible to drive the frame member 18 with respect to the reticle base 16 in three directions of freedom, that is, the X direction, the Y direction, and the θz direction.
[0061]
When the reticle stage RST is driven in the X direction, the Y direction, and the θz direction as described above, the frame member 18 slightly moves so as to cancel the action, and thus the reticle stage RST is moved in the XY plane of the frame member 18. The position may shift gradually. Therefore, the position of the frame-shaped member 18 is removed from the reticle base 16 by, for example, periodically returning the position of the frame-shaped member 18 to the center using a trim motor including the movers 60A to 60C and the stators 62A to 62C. Can be prevented.
[0062]
As shown in FIG. 3, a concave portion 18a is formed substantially at the center of the side wall on the −X direction side of the frame-shaped member 18. The concave portion 18a is formed with a rectangular opening 18b for communicating the inside and the outside of the frame-shaped member 18. In addition, a rectangular opening 18c that connects the inside and the outside of the frame-shaped member 18 is formed on the −Y side wall of the frame-shaped member 18. As can be seen from FIG. 5, an X-axis laser interferometer 69X is provided outside the rectangular opening 18b so as to face the reflecting surface 124m of the mirror section 24B of the reticle stage RST. The measurement beam from the X-axis laser interferometer 69X is projected onto the reflecting surface 124m of the mirror unit 24B via the rectangular opening 18b, and the reflected light enters the X-axis laser interferometer 69X via the rectangular opening 18b. Return. In this case, the position of the optical path of the length measuring beam in the Z direction coincides with the position of the neutral plane CT, and the position of the neutral plane CT coincides with the pattern surface (reticle surface) of the reticle R.
[0063]
As shown in FIG. 5, a fixed mirror Mrx is provided via a mounting member 92 near the upper end of the lens barrel of the projection optical system PL. The reference beam from the X-axis laser interferometer 69X is projected onto the fixed mirror Mrx via a through-hole (optical path) 71 formed in the reticle base 16, and the reflected light returns to the inside of the X-axis laser interferometer 69X. . In the X-axis laser interferometer 69X, the reflected light of the measurement beam and the reflected light of the reference beam are combined coaxially and in the same polarization direction by the internal optical system, and the interference light of both reflected lights is detected by the internal detector. Receive light. Then, based on the detection signal of the detector, the X-axis laser interferometer 69X constantly detects the position of the reticle stage main body 22 in the X direction with a resolution of, for example, about 0.5 to 1 nm with respect to the fixed mirror Mrx. Further, the speed of the reticle stage body 22 in the X direction (generally, approximately 0) is also detected from the difference in the position in the X direction.
[0064]
On the other hand, outside the rectangular opening 18c (on the −Y direction side), the above-mentioned retro-reflector 32A provided on the reticle stage main body 22 as shown in FIG. 6, which is a YZ sectional view near the reticle stage device 12 in FIG. , 32B, Y-axis laser interferometers 69YA, 69YB are provided opposite to the reflection surfaces. The measurement beams from each of the Y-axis laser interferometers 69YA and 69YB are projected onto the reflecting surfaces of the retro-reflectors 32A and 32B via the rectangular apertures 18c, and the respective reflected lights are transmitted via the window glass g2 to the respective Y-axis. The process returns to the laser interferometers 69YA and 69YB. In this case, the position of the irradiation point of the length measuring beam in the Z direction substantially coincides with the position of the neutral plane CT (reticle plane).
[0065]
As shown in FIG. 6, a fixed mirror Mry is provided via a mounting member 93 near the upper end of the lens barrel of the projection optical system PL. Reference beams from each of the Y-axis laser interferometers 69YA and 69YB are projected onto a fixed mirror Mry via a through-hole (optical path) 72 formed in the reticle base 16, and each reflected light is reflected by each of the Y-axis lasers. The process returns to the interferometers 69YA and 69YB. Each of the Y-axis laser interferometers 69YA and 69YB, based on the interference light between the reflected light of the measured beam and the reflected light of the reference beam, similarly to the X-axis laser interferometer 69X described above. The position in the Y direction of the reticle stage main body 22 at the projection position (the position of the reflecting surfaces of the retroreflectors 32A and 32B) is always detected with a resolution of, for example, about 0.5 to 1 nm with respect to the fixed mirror Mry. In this case, the rotation amount of the reticle stage RST around the Z axis can be detected by the pair of Y-axis laser interferometers 69YA and 69YB. Also, the speed of the reticle stage body 22 in the Y direction is detected from the difference in the Y direction position.
[0066]
In this example, as described above, since the position in the Z direction of the optical path of the length measurement beam of the X-axis laser interferometer 69X matches the position of the neutral plane CT (reticle plane), there is no so-called Abbe error. It is possible to accurately measure the position of reticle stage RST (reticle R) in the X direction. Also for the pair of Y-axis laser interferometers 69YA and 69YB, for the same reason, there is no so-called Abbe error, and high measurement accuracy can be obtained.
[0067]
Note that the three mirrors 24B and the retroreflectors 32A and 32B as the movable mirrors are illustrated as movable mirrors Mm in FIG. 1, and include an X-axis laser interferometer 69X and a pair of Y-axis laser interferometers 69YA and 69YB. However, it is illustrated as a reticle interferometer 69 in FIG. In FIG. 1, the fixed mirrors (fixed mirrors Mrx and Mry) of FIGS. 5 and 6 are not shown.
[0068]
In the following description, it is assumed that the position (including θz rotation) of reticle stage RST in the XY plane is measured by reticle interferometer 69. The position information (or velocity information) of the reticle stage RST from the reticle interferometer 69 is sent to the stage control system 90 of FIG. 1 and the main controller 70 via the stage control system 90. And controls the driving of reticle stage RST based on the position information of reticle stage RST.
[0069]
Referring back to FIG. 1, as the projection optical system PL, a reduction system having a projection magnification of 1/4 or 1/5, which is a bilateral telecentric refraction system or catadioptric system, is used. During the scanning exposure, a reduced image of the pattern in the illumination area IAR of the reticle R via the projection optical system PL is exposed on the wafer W placed on the image plane of the projection optical system PL under the exposure light IL. Is transferred onto the elongated exposure area IA on the resist layer in one shot area. The wafer W as a substrate to be exposed is a disc-shaped substrate such as a semiconductor (silicon or the like) or an SOI (silicon on insulator) having a diameter of, for example, 150 to 300 mm.
[0070]
The projection optical system PL is held by a holding member (not shown) via a flange portion FLG provided in the lens barrel.
Next, wafer stage WST is arranged in wafer chamber 80. The wafer chamber 80 is covered with a partition wall 71 in which a circular opening 71a for passing the lower end of the projection optical system PL is formed substantially in the center of the ceiling. The partition wall 71 is formed of a material with low degassing such as stainless steel (SUS).
[0071]
In the wafer chamber 80, a wafer base BS formed of a surface plate is supported substantially horizontally via a plurality of vibration isolation units 86. Wafer stage WST holds wafer W by vacuum suction or the like via wafer holder 25, and is driven in an XY two-dimensional direction along the upper surface of wafer base BS by a wafer drive system (not shown) including, for example, a linear motor.
[0072]
A light transmitting window 85 is provided on a side wall on the −Y direction side of the partition wall 71 of the wafer chamber 80. Similarly, although not shown, a light transmission window is also provided on the side wall of the partition 71 on the + X direction side. A Y-axis moving mirror 56Y, which is a plane mirror, extends in the X direction at an end of the wafer holder 25 on the −Y direction side. Similarly, although not shown, an X-axis moving mirror formed of a plane mirror extends in the Y direction at an end of the wafer holder 25 on the + X direction side. Then, the measurement beams from the Y-axis laser interferometer 57Y and the X-axis laser interferometer (not shown) outside the wafer chamber 80 are transmitted through the light transmission window 85 and the not-shown transmission window, respectively. And an X-axis movable mirror (not shown). The Y-axis laser interferometer 57Y and the X-axis laser interferometer respectively include, for example, the position and rotation angle of the corresponding moving mirror with reference to an internal reference mirror, that is, the position of the wafer W in the X and Y directions, and the X axis and The rotation angle around the axis and the Z axis is measured. The measurement values of the Y-axis laser interferometer 57Y and the X-axis laser interferometer are supplied to the stage control system 90 and the main control device 70, and the stage control system 90 performs the measurement based on the measured values and the control information from the main control device 70. Thus, the position and speed of wafer stage WST are controlled via a drive system (not shown).
[0073]
Next, the flow of a basic exposure operation by the projection exposure apparatus 10 configured as described above will be briefly described.
First, a reticle load and a wafer loader perform a reticle load and a wafer loader (not shown) under the control of the main controller 70. Thereafter, reticle alignment and wafer alignment are performed using a reticle alignment system, a reference mark plate on wafer stage WST, an off-axis alignment detection system (all not shown), and the like. Next, first, wafer stage WST is moved so that the position of wafer W becomes a scanning start position for exposure of a first shot area (first shot) on wafer W. At the same time, reticle stage RST is moved such that the position of reticle R becomes the scanning start position. Then, in accordance with an instruction from main controller 70, stage control system 90 measures the position information of reticle R measured by reticle interferometer 69, and measures the position by wafer-side Y-axis laser interferometer 57Y and X-axis laser interferometer. Based on the position information of the wafer W, the reticle R (reticle stage RST) and the wafer W (wafer stage WST) are synchronously moved in the Y direction (scanning direction) and irradiated with the exposure light IL, so that the first shot is performed. Scanning exposure is performed. Subsequently, after wafer stage WST moves stepwise by one shot area in the non-scanning direction (X direction) or Y direction, scanning exposure is performed on the next shot area. In this manner, the step movement between shots and the scanning exposure are sequentially repeated, and the pattern of the reticle R is transferred to each shot area on the wafer W.
[0074]
Next, a detailed configuration and a drive system of the four-axis Y-axis linear motors 76A, 78A, 76B, 78B of FIG. 5 for driving the reticle stage RST in the Y direction and the θz direction will be described. Hereinafter, assuming that the Y-axis linear motors 76A to 78B are three-phase linear motors, first, the configuration of the second and fourth Y-axis linear motors 78A and 78B will be described with reference to FIG.
[0075]
7A is a plan view showing a stator unit 138A of the second Y-axis linear motor 78A in FIG. 5, and FIG. 7B is a plan view showing a mover unit 28A of the Y-axis linear motor 78A. 7 (C) is a side view of FIG. 7 (B), FIG. 7 (D) is a front view of FIG. 7 (B), and FIG. 7 (E) is a Y direction of a magnetic flux density B generated by a magnet of the mover unit 28A. (This pitch is referred to as P). Note that FIG. 7B is also a cross-sectional view along the line BB in FIG. 7C. 7A to 7C, the reticle stage main body 22 is shown in a simplified manner.
[0076]
As shown in FIG. 7B, the mover unit 28A of the Y-axis linear motor 78A includes a permanent magnet MN that generates a magnetic field in the Z direction and a permanent magnet MS that is the permanent magnet MN inverted in the Z direction. It is arranged on the reticle stage main body 22 at a pitch P / 2 (P is the pitch of the magnetic flux density B) alternately in the direction. The portion of the reticle stage main body 22 where the permanent magnets MN and MS are arranged also functions as a yoke. Also, as shown in FIG. 7D, the mover unit 28B of the fourth Y-axis linear motor 78B is opposed to each permanent magnet of the mover unit 28A of the second Y-axis linear motor 78A. Each of the permanent magnets has a polarity inverted in the Z direction and is arranged in the Y direction.
[0077]
Next, as shown in FIGS. 7A and 7D, the stator unit 138A of the second Y-axis linear motor 78A includes a number of coils crossing the magnetic field in the X direction at a pitch P1 (= 2P) in the Y direction. / 3), and the stator unit 138B of the fourth Y-axis linear motor 78B is also configured symmetrically with the stator unit 138A. In this case, the distribution of the magnetic flux density B at the pitch P in FIG. 7 (E) represents the magnetic flux density generated in the stator unit 138A above it by the mover unit 28A, and is fixed therebelow by the mover unit 28B. The magnetic flux density generated in the slave unit 138B is inverted in polarity from that in FIG. Then, the stator units 138A and 138B sequentially apply the U-phase (0π) coil CU, the V-phase (-2π / 3 or + 4π / 3) coil CV, and the W-phase (+ 2π / 3) coil CW to Y, respectively. It is arranged in the direction. Since the polarity of the magnetic field acting on the stator unit 138A and the polarity of the magnetic field acting on the stator unit 138B are reversed, the coil of the lower stator unit 138B has the same polarity as the coil of the upper stator unit 138A. Current is supplied in the opposite direction.
[0078]
The first and third Y-axis linear motors 76A and 76B in FIG. 5 are configured similarly to the second and fourth Y-axis linear motors 78A and 78B in FIG. 7D.
Next, FIG. 8 shows a drive system of the stator unit 138A of the second Y-axis linear motor 78A. In FIG. 8, a plurality of U-phase coils CU of the stator unit 138A are formed as a U-phase coil group 196U. The plurality of W-phase coils CW are star-connected as a W-phase coil group 196W, and the plurality of V-phase coils CV are star-connected as a V-phase coil group 196V. These U-phase, W-phase, and V-phase coil groups One common terminal of 196U, 196W, and 196V is connected to the ground terminal G. Note that the drive system described below is incorporated in the stage control system 90 of FIG.
[0079]
In FIG. 8, a control unit 90A for supplying a current to each coil of the stator unit 138A is disposed, and a current value setting unit 190 including a digital signal processor is disposed in the control unit 90A. Further, the measurement values of the X-axis laser interferometer 69X and the Y-axis laser interferometers 69YA and 69YB are supplied to an external reticle stage controller 90R including a computer. The reticle stage control unit 90R sets the speed of the reticle stage main body 22 in the Y direction by the Y-axis linear motor 78A at a predetermined cycle based on the control information from the main controller 70 and the measurement values of the laser interferometer. Commands are sequentially supplied to the current value setting unit 190. The current value setting unit 190 calculates the thrust in the Y direction of the Y-axis linear motor 78A according to the speed command, and the U-phase, W-phase, and V-phase coil groups 196U, 196W, A current value of each coil of 196 V is calculated, and voltages corresponding to the calculated current values are output to U-phase, W-phase, and V-phase amplifiers 191U, 191W, and 191V, respectively. The amplifiers 191U, 191W, and 191V output a current corresponding to the input voltage.
[0080]
At this time, information on the thrust constants (thrust generated per unit current) relating to the U-phase, W-phase, and V-phase coil groups 196U, 196W, and 196V are transmitted from the reticle stage control unit 90R to the current value setting unit 190 in advance. The current value setting unit 190 calculates the current of each coil group based on the thrust constant. The control unit 90A outputs three drive terminals 197U, 197W, and 197V to which a drive current is output and to which a voltage generated externally is applied as necessary, and three terminals for connecting to an external voltmeter. Voltage measurement terminals 193U, 193W, and 193V are provided. Further, a first switch 192U for connecting the output terminal 197U to either the U-phase amplifier 191U or the voltage measurement terminal 193U, and the output terminal 197W to any of the W-phase amplifier 191W or the voltage measurement terminal 193W. A second switch 192W for connection is provided, and a third switch 192V for connecting the output terminal 197V to either the V-phase amplifier 191V or the voltage measurement terminal 193V. The changeover switches 192U, 192W, 192V can be switched by a manual method.
[0081]
The three output terminals 197U, 197W, and 197V are connected to the other common terminals of the U-phase, W-phase, and V-phase coil groups 196U, 196W, and 196V, respectively. In this case, between each coil of the V-phase coil group 196V and the output terminal 197V, between each coil of the U-phase coil group 196U and the output terminal 197U, and each coil and the output terminal of the W-phase coil group 196W. The switching elements S01 to S09, S11 to S20, S21 to S30, which can electronically switch on and off the current flow, are connected between the output terminal 197W and the output terminal 197V and the ground terminal G. Further, a switching element S10, which is the same as the switching element S01, and a dummy resistor 138R are connected in series. The switching of the switching elements S01 to S30 is performed by the current value setting unit 190. The switching element S10 is normally turned off (cut off).
[0082]
As shown in FIG. 7 (D), since the Y-axis linear motor 78A of this example is a moving magnet type, it does not face the mover unit 28A in the stator unit 138A and does not contribute to the generation of thrust. There is a coil. Therefore, in this example, the position in the Y direction measured by the Y-axis laser interferometers 69YA and 69YB in FIG. 8 is supplied to the current value setting unit 190 via the reticle stage control unit 90R, and the current value setting unit 190 From the position in the Y direction (Y coordinate of the mover unit 28A), a coil that does not contribute to the generation of thrust is specified. Then, the current value setting unit 190 turns off (cuts off) the switching element connected to the coil that does not contribute to the generation of the thrust among the switching elements S01 to S30. As a result, the current consumption of the coil unit of stator unit 138A can be reduced, and the temperature rise of reticle stage RST (reticle R) can be suppressed.
[0083]
Note that the stator unit 136A of the first Y-axis linear motor 76A in FIG. 5 and its control unit are also configured in the same manner as the stator unit 138A and the control unit 90A of the second Y-axis linear motor 78A in FIG. The control unit of the stator unit 136A is also controlled by the reticle stage control unit 90R.
Next, FIG. 9 shows a drive system of the stator unit 138B of the fourth Y-axis linear motor 78B. In FIG. 9, the stator unit 138B and its control unit 90B are the same as those of the stator unit 138A of FIG. The configuration is the same as that of the control unit 90A. Further, the stator unit 136B of the second Y-axis linear motor 76B of FIG. 5 and its control unit are also configured in the same manner as the stator unit 138B and its control unit 90B of FIG. 9, and the current value setting in the control unit 90B is performed. The unit 190 is also controlled by the reticle stage control unit 90R.
[0084]
In FIG. 9, a voltmeter 194 is connected to the voltage measurement terminals 193U, 193W, and 193V. The voltmeter 194 measures the voltages of the voltage measurement terminals 193U, 193W, and 193V in parallel at a predetermined timing, and supplies the measurement data as digital data to the reticle stage control unit 90R.
Next, an example of the operation of correcting the thrust constant for driving the four-axis Y-axis linear motors 76A, 78A, 76B, 78B of FIG. 5 will be described with reference to the flowchart of FIG. The operation of correcting the thrust constant is executed, for example, at the time when the assembly and adjustment of the mechanism of the projection exposure apparatus of the present embodiment is completed, or at the time of maintenance.
[0085]
First, in step 201 of FIG. 12, in the control unit 90A for the first and second Y-axis linear motors 76A and 78A of FIG. 8, for example, the operator sets the changeover switches 192U, 192W and 192V to the U-phase and W-phase, respectively. The output terminals of the V-phase amplifiers 191U, 191W, and 191V are set to be connected to the output terminals 197U, 197W, and 197V (the state of FIG. 8). As a result, the first and second Y-axis linear motors 76A and 78A are driven based on the thrust constant preset in the current value setting unit 190 from the reticle stage control unit 90R.
[0086]
FIG. 10 shows an example of the thrust constant set in the current value setting unit 190 in FIG. 8. In FIG. 10, the sinusoidal curves CFU, CFV, and CFW correspond to the U-phase, V-phase, and W-phase, respectively. Thrust constant (thrust generated per unit current) (N / A). This thrust constant is based on the theoretical value of the magnetic flux density B shown in FIG. 7 (E) as an example. The magnetic flux density B has a peak value of B ₀ Can be expressed as a function of the position of the reticle stage body 22 in the Y direction as follows.
[0087]
B = B ₀ sin (2πY / P) (11)
In the example of FIG. 10, the pitch P is about 70 mm. Then, the thrust constants of the U, W, and V phases represented by the curves CFU, CFW, and CFV in FIG. 10 are defined as FAU (Y), FAW (Y), and FAV (Y), and the U phase in FIG. The currents IAu, IAw, IAv supplied to the W-phase and V-phase coil groups 196U, 196W, 196V are set as follows. The position Y is the position of the mover unit 28A in the Y direction with respect to the stator unit 138A in FIG. ₀ And
[0088]
IAu = I ₀ sin (2πY / P) (12)
IAv = I ₀ sin (2πY / P-2π / 3) (13)
IAw = I ₀ sin (2πY / P + 2π / 3) (14)
Then, the current value setting unit 190 in FIG. 8 calculates the entire thrust FAt generated in the U-phase, W-phase, and V-phase coil groups 196U, 196W, and 196V using the following equation.
[0089]
FAt = FAU (Y) · IAu + FAW (Y) · IAw +
FAV (Y) ・ IAv… (15)
Then, the current value setting unit 190 determines, for example, the peak value I of the current so that the total thrust FAt of the three phases in the equation (15) matches half of the target value. ₀ Should be set. It should be noted that the two stator units 136A and 138A in FIG. 5 generate the same thrust, so that the total thrust becomes a target value.
[0090]
At the beginning of step 201 in FIG. 12, in the control unit 90B of the third and fourth Y-axis linear motors 76B and 78B in FIG. 9, for example, the operator sets the changeover switches 192U, 192W and 192V to the output terminals 197U, 197W and 197W, respectively. 197V is set so as to be connected to the voltage measurement terminals 193U, 193W, 193V (the state of FIG. 9). In addition, a voltmeter 194 is connected to the voltage measurement terminals 193U, 193W, and 193V so that the measurement value of the voltmeter 194 is taken into the reticle stage control unit 90R. Two voltmeters 194 are prepared for the third and fourth Y-axis linear motors 76B and 78B. As a result, the third and fourth Y-axis linear motors 76B and 78B are set to a state where no thrust is generated, and the U-phase, W-phase and V-phase coil groups 196U and 196W of the Y-axis linear motors 76B and 78B are set. , 196 V can be measured by the voltmeter 194.
[0091]
In this state, the first and second Y-axis linear motors 76A and 78A in the upper part of FIG. 5 are driven under the control of the main controller 70 and the reticle stage controller 90R in FIG. The reticle stage main body 22 is driven at a substantially constant speed in the Y direction over the entire stroke, and at the same time, the X-axis voice coil motor 79 is driven to keep the reticle stage RST in the X direction constant. Thus, a pair of Y-axis linear motors 76A and 78A and an X-axis voice coil motor 79 arranged symmetrically apart in the X direction, which is the direction intersecting the driving direction (Y direction) of reticle stage RST, are used. By driving the reticle stage RST, the reticle stage RST can be moved straight in the Y direction without fear of rotation. As shown in step 202 in parallel with this operation, reticle stage control section 90R in FIG. 9 performs third and fourth measurement by Y-axis laser interferometers 69YA and 69YB and two voltmeters 194. Of the three-phase coil groups 196U, 196W, 196V of the Y-axis linear motors 76B, 78B are sequentially loaded into the storage unit at a predetermined sampling rate.
[0092]
In this case, the stator units 136B and 138B of the third and fourth Y-axis linear motors 76B and 78B in FIG. 5 of this example are separated from the drive circuit. Therefore, when the mover units 26B and 28B relatively move in the Y direction with respect to the stator units 136B and 138B, the three-phase coil groups 196U, 196W, and 196V of the stator units 136B and 138B in FIG. A counter electromotive force (induced electromotive force) (V) is generated in the coil according to Fleming's right-hand rule. The back electromotive force corresponds to the electromotive force of the present invention. The back electromotive force generated in each coil is measured by a voltmeter 194 via voltage measurement terminals 193U, 193W, 193V.
[0093]
In the next step 203, the calculation unit in the reticle stage control unit 90R corrects the thrust constant of each phase of the third and fourth Y-axis linear motors 76B, 78B. For this reason, the arithmetic unit in the reticle stage control unit 90R calculates each of the Y directions of the reticle stage RST from the difference between the measured values of the Y coordinate of the Y-axis laser interferometers 69YA and 69YB sequentially acquired at a predetermined sampling rate in step 202. The velocity VYi of the reticle stage RST in the Y direction at the position Yi (i = 1, 2, 3,...) Is calculated.
[0094]
In this case, a value obtained by dividing the back electromotive force generated in each coil of the linear motor by the relative moving speed between the mover and the stator at the time of measurement is called a back electromotive force constant (V · s / m). It is known that this back electromotive force constant is equal to the thrust constant of each phase. Therefore, the calculation unit of reticle stage control unit 90R calculates the U-phase, W-phase, and V-phase back electromotive force of third Y-axis linear motor 76B measured at each position Yi in the Y direction by moving reticle stage RST. By dividing by the speed VYi, the back electromotive force constants VBUi, VBWi, VBVi of the U phase, W phase, and V phase are calculated, and the back electromotive force constant of each of these phases is set as the thrust constant of each phase. This thrust constant is calculated independently of each other by the third and fourth Y-axis linear motors 76B and 78B.
[0095]
FIG. 11 shows an example of the three-phase back electromotive force constant calculated in this manner, and the data on the curves CVU, CVW, and CVV are the back electromotive force constants VBUi, VBWi, and VBVi, respectively. The calculation unit of the reticle stage control unit 90R converts the back electromotive force constants VBUi, VBWi, VBVi into values at a series of positions at predetermined intervals in the Y direction by interpolation, for example, and obtains a thrust constant FBU (Y), FBW (Y) and FBV (Y) are set in the current value setting section 190 of the control section 90B of the third and fourth Y-axis linear motors 76B and 78B in FIG. This completes the correction of the thrust constant.
[0096]
It should be noted that currents similar to the expressions (12) to (14) supplied to the U-phase, W-phase, and V-phase coil groups 196U, 196W, and 196V of the stator unit 138B (or 136B) in FIG. , IBw, and IBv, the thrust FBt of the Y-axis linear motor 78B (or 76B) as a whole is calculated by using the corrected thrust constants FBU (Y), FBW (Y), and FBV (Y) as shown in the following equation (15). It can be determined from the following equation.
[0097]

Here, assuming that the current peak value Io in equations (12) to (14) is 1 (unit current), this thrust FBt is equal to the thrust constant FB (Y) of the entire Y-axis linear motor 78B (or 76B). Become. This thrust constant FB (Y) is represented as a curve CV in FIG. As can be seen from the curve CV, the thrust constant FB (Y), which should be constant, slightly fluctuates depending on the position Y. This means that the measured and corrected thrust constants FBU (Y), FBW (Y), and FBV (Y) were slightly different from the initially set thrust constants.
[0098]
Therefore, when driving the third and fourth Y-axis linear motors 76B and 78B next, the current value setting unit 190 in FIG. 9 uses the corrected thrust constants FBU (Y), FBW (Y), and FBV. (Y) The three-phase currents IBu, IBw, and IBv are set so that the thrust FBt obtained by substituting the currents IBu, IBw, and IBv supplied to the three-phase coil group into the equation (16) becomes a target value. Set. Thereby, the mover units 26B and 28B can be driven with high accuracy with the target thrust based on the actually measured value of the thrust constant.
[0099]
In the next step 204, in the control unit 90A for the first and second Y-axis linear motors 76A and 78A in FIG. 8, for example, the operator sets the changeover switches 192U, 192W and 192V to the output terminals 197U, 197W and 197V respectively. It is set to be connected to the measurement terminals 193U, 193W, 193V. The voltmeter 194 shown in FIG. 9 is connected to the voltage measurement terminals 193U, 193W, and 193V so that the measured value of the voltmeter 194 is taken into the reticle stage control unit 90R. Two voltmeters 194 are provided for the first and second Y-axis linear motors 76A and 78A. As a result, the first and second Y-axis linear motors 76A, 78A are set to generate no thrust, and the U-phase, W-phase, and V-phase coil groups 196U, 196W of the Y-axis linear motors 76A, 78A are set. , 196 V can be measured by the voltmeter 194.
[0100]
Further, in the control unit 90B of the third and fourth Y-axis linear motors 76B and 78B in FIG. 9, for example, the operator sets the changeover switches 192U, 192W and 192V to U-phase, W-phase and V-phase amplifiers 191U and 191W, respectively. The output terminals of 191V are set so as to be connected to the output terminals 197U, 197W and 197V. Thus, the third and fourth Y-axis linear motors 76B and 78B are driven based on the thrust constant corrected in step 203 and the above equation (16).
[0101]
In this state, under the control of the main controller 70 and the reticle stage controller 90R in FIG. 9, the lower and fourth Y-axis linear motors 76B and 78B shown in FIG. (The reticle stage main body 22) is driven at a substantially constant speed in the Y direction in all strokes. As shown in step 205 in parallel with this operation, the reticle stage control unit 90R of FIG. 8 performs the measurement of the Y-axis laser interferometers 69YA and 69YB and the first and second voltmeters 194. The counter electromotive force generated by the three-phase coil groups 196U, 196W, and 196V of the two Y-axis linear motors 76B and 78B are sequentially loaded into the storage unit at a predetermined sampling rate.
[0102]
In the next step 206, reticle stage control section 90R corrects the thrust constant of each phase of first and second Y-axis linear motors 76A and 78A in the same manner as in step 203. The corrected thrust constant is set in the current value setting section 190 of the control section 90A of the first and second Y-axis linear motors 76A and 78A in FIG. Next, when driving the first and second Y-axis linear motors 76A and 78A, the current value setting unit 190 in FIG. 8 uses the corrected thrust constants FAU (Y), Faw (Y), and FAV (Y). ) And the currents IAu, IAw, and IAv supplied to the three-phase coil group are substituted into Equation (15) so that the three-phase currents IAu, IAw, and IAv become target values. Set. Thus, the mover units 26A and 28A can be driven with high accuracy with the target thrust based on the actually measured value of the thrust constant.
[0103]
As a result, the thrust constants of the four-axis Y-axis linear motors 76A, 78A, 76B, and 78B shown in FIG. That is, the correction was made. Therefore, a thrust error caused by a mounting error or the like of the Y-axis linear motors 76A, 78A, 76B, 78B is corrected, so that the positioning property and the uniform velocity can be improved.
[0104]
In the next step 207, for example, the operator sets the changeover switches 192U, 192W, 192V to the U-phase, W-phase, and V-phase in the control unit 90A of the first and second Y-axis linear motors 76A, 78A in FIG. The output terminals of the amplifiers 191U, 191W, and 191V are set to be connected to the output terminals 197U, 197W, and 197V. Thereafter, the four-axis Y-axis linear motors 76A, 78A, 76B, 78B can be driven synchronously using the corrected thrust constant.
[0105]
Therefore, as an example, under the control of the main controller 70 and the reticle stage controller 90R of FIG. 8, the four-axis Y-axis linear motors 76A, 78A, 76B, 78B of FIG. The reticle stage RST is driven in the Y direction and the θz direction to move the reticle stage RST to the reticle loading position. Thereafter, in step 208, a normal exposure process is performed. In this exposure step, the four-axis Y-axis linear motors 76A, 78A, 76B, 78B shown in FIG. 5 are driven using the corrected thrust constant, so that the reticle stage RST (reticle R) can be moved with a desired thrust at high precision. Can be driven.
[0106]
However, in this example, it is necessary to separately prepare a voltmeter 194 to switch the switches 192U, 192W, and 192V of the control units 90A and 90B and to connect the wires when measuring the back electromotive force. However, there is an advantage that the voltmeter does not need to be constantly provided in the apparatus main body, and the cost of the entire apparatus does not increase.
Further, software (program) for obtaining a thrust constant from the measured value of the back electromotive force is stored in reticle stage control section 90R. Alternatively, the operation of obtaining the thrust constant from the measured value of the back electromotive force may be executed by an external computer, and the obtained thrust constant may be written by the operator into the reticle stage control unit 90R.
[0107]
As described above, the stator units 138A and 138B of the Y-axis linear motors 78A and 78B shown in FIG. 7 of the present example are configured by a plurality of coils having an arrangement pitch P1 of 2P / 3. As a modified example, a plurality of coils constituting the stator unit may be arranged at a smaller pitch as shown in FIG. 13 in which portions corresponding to FIG. 7 are assigned the same or similar reference numerals.
[0108]
FIG. 13A is a plan view showing a stator unit 198A of the Y-axis linear motor 78A of the modification, FIG. 13B is a plan view showing a mover unit 28A of the Y-axis linear motor 78A, and FIG. 13C is a side view of FIG. 13B, FIG. 13D is a front view of FIG. 13B, and FIG. 13E is a magnetic flux density B (pitch P) generated by a magnet of the mover unit 28A. Respectively in the Y direction.
[0109]
As shown in FIG. 13D, a pair of Y-axis linear motors 78A and 78B of this modification have stator units 198A and 198B and mover units 28A and 28B, respectively. , 28B are the same as in the example of FIG. On the other hand, the upper stator unit 198A is configured by stacking three layers of coil units in the direction of the magnetic field (Z direction), and the coil unit of the first layer has a U-phase ( A coil CU of 0π), a coil CV of V phase (-2π / 3), and a coil CW of W phase (+ 2π / 3) are sequentially arranged in the Y direction at a pitch P1 (= 2P / 3). Further, the coil units of the second layer include coils CV1 (V phase) and CW1 (W phase) obtained by shifting the coils CU, CV, CW,... Of the first layer in the Y direction by P2 (= P / 6), respectively. ), CU1 (U-phase),..., And the third-layer coil unit further shifts the second-layer coils CV1, CW1, CU1,. CU2 (W-phase), CU2 (U-phase), CV2 (V-phase),...
[0110]
In this case, the mechanical phases of the coils CV1, CW1, and CU1 of the second layer are π / 3, 5π / 3, and π / 2, respectively. Phase, U phase. Therefore, the U-phase, W-phase, and V-phase coil groups of the stator unit 198A can be driven by a circuit similar to the drive system of FIG.
Further, as shown in FIG. 13D, the lower stator unit 198B is composed of the same three-layer coil unit as the upper stator unit 198A, and these coil units are also U-phase and V-phase. , W-phase coil group. Therefore, the stator unit 198B can be driven by a circuit similar to the drive system of FIG.
[0111]
In the above embodiment, a three-phase linear motor is used, but a two-phase or four-phase linear motor can also be used. Furthermore, in the above embodiment, a moving magnet type linear motor is used to drive the reticle stage RST, but a moving coil type linear motor can also be used.
[0112]
Next, a second embodiment of the present invention will be described with reference to FIG. In this example, a voltmeter is provided in the control section 90A of FIG. 8, and the portions corresponding to FIG. 8 in FIG. 14 are denoted by the same reference numerals, and detailed description thereof will be omitted.
FIG. 14 shows a drive system of the stator unit 138A of the second Y-axis linear motor 78A (see FIG. 5) of the present embodiment. In FIG. 14, the manual type changeover switches 192U, 192W, 192V of FIG. Instead, switching elements 195U, 195W, and 195V that can be switched by a control signal from main controller 70 are provided. A voltmeter 194 is provided in the control unit 90A, and one output unit of each of the switching elements 195U, 195W, and 195V is connected to a measurement signal input unit of the voltmeter 194. The voltmeter 194 has a function of taking in the voltages of the three measurement signal input units in parallel at a predetermined sampling rate, and supplying the measurement data as digital data to the reticle stage control unit 90R. Other configurations are the same as in the example of FIG.
[0113]
In the embodiment of FIG. 14, when driving the Y-axis linear motor 78A, the switching elements 195U, 195W, and 195V are connected to the output terminals of the U-phase, W-phase, and V-phase amplifiers 191U, 191W, and 191V, respectively. It is set to be connected to 197U, 197W, 197V. On the other hand, when measuring the back electromotive force of the three-phase coil group of the stator unit 138A, the switching elements 195U, 195W, and 195V are connected to the output terminals 197U, 197W, and 197V, respectively, to the measurement signal input section of the voltmeter 194. Set to be connected. Thus, for example, even during the exposure process, the thrust constant can be corrected by automatically measuring the back electromotive force of the three-phase coil group of the stator unit 138A.
[0114]
As described above, in this example, since the voltmeter 194 is built into the control unit 90A from the beginning, it is possible to measure the thrust constant at any time without using any special tool. It is effective for Further, for example, when a thrust abnormality or other abnormality is detected during exposure, there is an advantage that the presence or absence of a failure of the linear motor such as a coil dielectric breakdown or disconnection can be immediately detected.
[0115]
Next, a third embodiment of the present invention will be described with reference to FIG. In this example, the present invention is applied to a case where the stage is driven along a predetermined guide.
FIG. 15 is a perspective view showing a main part of the stage device of the present example. In FIG. 15, the X-axis and the Y-axis are taken in two directions orthogonal to the surface of the base 301 formed of the surface plate. A Y-axis guide 302 is provided on the base 301 along the Y-direction, and a slider 304 is arranged movably in the Y-direction along the Y-axis guide 302. A table 303 is fixed to the slider 304, and a central portion of the table 303 is provided. A moving object 306 such as a reticle is held via a holder 305. At the center of the holder 305 and at a corresponding portion of the table 303, for example, an opening for transmitting light transmitted through the moving object 306 is formed, and an opening 301a for transmitting the light is also formed on the base 301. ing.
[0116]
Further, stators 308A and 308B each including a magnet unit are arranged in parallel with the Y axis so as to sandwich the Y axis guide 302 in the X direction, and the stators 308A and 308B are fixed to the base 301 by a holding member (not shown). ing. In addition, movers 307A and 307B each including a coil unit are connected to the stators 308A and 308B so as to be relatively movable in the Y direction, and the movers 307A and 307B are fixed to the bottom surface of the table 303. In this case, a first Y-axis linear motor 309A is constituted by the mover 307A and the stator 308A, and a second Y-axis linear motor 309B is constituted by the mover 307B and the stator 308B. Furthermore, the position of the table 303 in the Y direction is measured by irradiating the movable mirror 310 provided on the holder 305 with a measurement laser beam from the external laser interferometer 311, and the Y axis linear position is determined based on the measured value. Motors 309A and 309B are driven.
[0117]
The table 303 (second member) of this example moves with one degree of freedom in the Y direction along the Y-axis guide 302 with respect to the base 301 (first member), and moves the table 303 with respect to the base 301 in the Y direction. As a driving device for driving the motors, two Y-axis linear motors 309A and 309B separated in the X direction are provided. Therefore, since the number of axes of the driving device is larger by one than the degree of freedom of movement, for example, the table 303 is driven in the Y direction only by the first Y-axis linear motor 309A, and the second Y-axis linear motor 309B is driven. By setting a state in which no thrust is generated, the back electromotive force generated in the coil group in the mover 307B can be measured. As a result, the thrust constant of the second Y-axis linear motor 309B can be corrected. Similarly, by driving the table 303 with only the second Y-axis linear motor 309B and measuring the back electromotive force generated in the coil group in the mover 307A of the first Y-axis linear motor 309A, the first , The thrust constant of the Y-axis linear motor 309A can be corrected.
[0118]
In this example, it is possible to move the table 303 in the Y direction by using only one of the linear motors (309A or 309B), but the positioning performance and the uniform velocity are controlled by the two-axis Y-axis linear motors 309A and 309B. Inferior to. However, even if you do not move at the maximum speed as a stage device, there is no problem in back EMF measurement, so it is generated in the coil by reducing the stage speed to the extent that abnormal mechanical resonance and other problems do not occur The back electromotive force can be measured, and the thrust constant can be corrected as in the first embodiment. Thereby, the positioning performance and the uniform velocity can be improved.
[0119]
The projection exposure apparatus according to the above-described embodiment includes an illumination optical system composed of a plurality of lenses, a projection optical system incorporated in an exposure apparatus main body, optical adjustment, and a reticle stage or a wafer stage composed of many mechanical parts. Can be manufactured by attaching wires and pipes to the exposure apparatus main body, and performing overall adjustment (electrical adjustment, operation confirmation, etc.). It is desirable that the exposure apparatus be manufactured in a clean room in which temperature, cleanliness, and the like are controlled.
[0120]
In the case of manufacturing a semiconductor device using the projection exposure apparatus of the above embodiment, the semiconductor device has a step of designing the function and performance of the device, a step of manufacturing a reticle based on this step, A step of forming a wafer, a step of exposing the reticle pattern to the wafer by performing alignment using the projection exposure apparatus of the above-described embodiment, a step of forming a circuit pattern such as etching, a device assembling step (dicing step, bonding step, (Including a package process) and an inspection step.
[0121]
The present invention can be applied not only to a reticle stage of an exposure apparatus, but also to a wafer stage. Further, the present invention can be applied not only to a scanning exposure type exposure apparatus, but also to a reticle stage and a wafer stage of a batch exposure type exposure apparatus. Further, the application of the exposure apparatus of the present invention is not limited to an exposure apparatus for manufacturing a semiconductor device, for example, a liquid crystal display element formed on a square glass plate, or an exposure apparatus for a display apparatus such as a plasma display. The present invention can be widely applied to an apparatus and an exposure apparatus for manufacturing various devices such as an imaging device (such as a CCD), a micro machine, a thin film magnetic head, and a DNA chip. Further, the present invention can be applied to an exposure step (exposure apparatus) when manufacturing a mask (photomask, reticle, or the like) on which mask patterns of various devices are formed by using a photolithography step.
[0122]
It should be noted that the present invention is not limited to the above-described embodiment, and it is needless to say that various configurations can be adopted without departing from the gist of the present invention.
[0123]
【The invention's effect】
According to the present invention, since the electromotive force of a driving device that does not generate thrust is detected, the driving performance of the driving device can be improved, and the member to be moved can be driven with high accuracy. .
In addition, various devices can be manufactured with high accuracy by applying the present invention to an exposure apparatus.
[Brief description of the drawings]
FIG. 1 is a partially cutaway view showing a schematic configuration of a projection exposure apparatus according to a first embodiment of the present invention.
FIG. 2 is a perspective view showing a configuration of a frame member 18 and a reticle stage RST of FIG.
FIG. 3 is an exploded perspective view showing a configuration of a reticle stage RST, a frame member 18, and a reticle base 16 of FIG.
4A is a perspective view showing a reticle stage RST of FIG. 1, and FIG. 4B is a cross-sectional view of the reticle stage RST viewed in a Y direction.
FIG. 5 is a cross-sectional view of the illumination system side plate 14, reticle stage RST, and reticle base 16 of FIG. 1 as viewed in a Y direction.
FIG. 6 is a cross-sectional view of a main part of an illumination system side plate 14, a reticle stage RST, and a reticle base 16 of FIG. 1 as viewed in an X direction.
7 is a diagram showing a configuration of stator units 138A, 138B and mover units 28A, 28B of Y-axis linear motors 78A, 78B of FIG.
FIG. 8 is a diagram showing a drive system of one stator unit 138A of FIG. 7;
FIG. 9 is a diagram illustrating a drive system of the other stator unit 138B of FIG. 7;
FIG. 10 is a diagram illustrating an example of a thrust constant of a Y-axis linear motor 78A in FIG. 7;
11 is a diagram illustrating an example of a back electromotive force constant of the Y-axis linear motor 78B in FIG. 7;
FIG. 12 is a flowchart illustrating an example of an operation for correcting a thrust constant of a linear motor according to the first embodiment of the present invention.
FIG. 13 is a view showing a modification of the stator unit of the Y-axis linear motors 78A and 78B of FIG.
FIG. 14 is a diagram illustrating a drive system of a stator unit 138A of the linear motor according to the second embodiment of the present invention.
FIG. 15 is a perspective view showing a main part of a stage device according to a third embodiment of the present invention.
[Explanation of symbols]
RST: reticle stage, R: reticle, 16: reticle base, 18: frame member, 76A, 78A, 76B, 78B: Y-axis linear motor, 136A, 138A, 136B, 138B: Stator unit, 26A, 28A, 26B , 28B: mover unit, 69YA, 69YB: Y-axis laser interferometer, 90R: reticle stage control unit, 90A, 90B: control unit, 190: current value setting unit, 192U, 192W, 192V: changeover switch, 193U, 193W , 193V: voltage measurement terminal, 194: voltmeter, 196U, 196W, 196V: coil group

Claims (7)

In a stage device that relatively drives the second member in at least one direction with respect to the first member,
A plurality of driving devices each of which generates a thrust by the electromagnetic force in the one direction and drives the second member relatively to the first member;
When the second member is driven in the one direction by the thrust generated by a part of the plurality of driving devices, the other driving that does not generate the thrust of the plurality of driving devices A detection device for detecting an electromotive force generated in the device. The relative degree of freedom of driving the second member with respect to the first member is N (N is an integer of 1 or more),
The stage device according to claim 1, wherein the number of the plurality of driving devices that relatively drives the second member with the degree of freedom N with respect to the first member is at least (N + 1). The plurality of driving devices that relatively drive the second member in the one direction with respect to the first member, a first pair of driving devices disposed in a direction intersecting the one direction, A second pair of drives arranged opposite to the first pair of drives,
The detection device is generated in the second pair of driving devices when the second member is driven in the one direction with respect to the first member via the first pair of driving devices. The stage device according to claim 1, wherein an electromotive force is detected. A position measuring device for measuring the position of the second member,
A control device for controlling the driving device by correcting the thrust generated by the other driving device based on the moving speed of the second member obtained by the position measuring device and the electromotive force detected by the detecting device The stage device according to any one of claims 1 to 3, further comprising: The one or more of the plurality of driving devices that generate thrust and the other driving device that does not generate thrust are switchable with each other. A stage device according to the item. A driving method of the stage device according to any one of claims 1 to 5,
When the second member is driven in the one direction by the thrust generated by a part of the plurality of driving devices, another driving that does not generate the thrust is generated among the plurality of driving devices. A first step of detecting an electromotive force generated in the device;
A second step of obtaining a correction value of a thrust generated by the other drive device based on the electromotive force detected in the first step;
And d) driving the second member by correcting the thrust generated by the other driving device using the correction value obtained in the second step. An exposure apparatus that illuminates a first object with an exposure beam and exposes a second object via the first object with the exposure beam,
An exposure apparatus using the stage device according to any one of claims 1 to 5 for driving at least one of the first object and the second object.

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