JP2004254377A - Linear motor device, stage device, exposure device, and manufacturing method of linear motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a linear motor device and a manufacturing method thereof, and a stage device and an exposure device provided with the linear motor device, capable of improving alignment precision and controlling performance by effectively suppressing the generation of thrust ripples. <P>SOLUTION: The linear motor device comprises a coil train where a plurality of coils 13 are arrayed. For each of a plurality of coils 13 that form the coil train, a first dimension L1 from a coil center C, that is the central position of the coil 13 to a first pole center C1 that is the central position of a longitudinal section 13a contributing to the generation of thrust, is set almost equal to a second dimension L2 from the coil center C to a second pole center C2 that is the central position of a longitudinal section 13b contributing to the generation of thrust. For the coil train, a plurality of coils 13 are so arrayed such that the position of the first pole center C1, relative to the coil center C of the coil 13, is almost identical with the position of the second pole center C2 relative to it. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【００３１】
上記（１）式において、αはコイル１３の極中心のｙ方向の位置を磁石列２４，２５で形成される磁界の位相で表した変数である。この（１）式を参照すると、各相のコイル１３に印加される電流Ｉｕ，Ｉｖ，Ｉｗは当然ながら位相ずれが生じていないが、Ｕ相のコイル１３の極中心に形成される磁界の位相がｔ°の分だけずれていることが分かる。尚、上記（１）式では簡単化のため磁界の大きさ及び電流の大きさを「１」に正規化してある。
【００３２】
図５を用いて説明したように、位相１２０°の分の磁界がコイル１３の１つの極中心の推力発生に寄与する点を考慮しつつ、三相のコイル１３により生ずる推力の合成推力Ｆは以下の（２）式で表される。
Ｆ＝１＋０．５・ｃｏｓ（ｔ）＋０．５・（ｃｏｓ（２α）−ｃｏｓ（２α＋ｔ））……（２）
【００３３】
上記（２）式から合成推力Ｆには２αの周期を有する推力リップルが含まれることが分かる。このように、コイル列１４に含まれるコイル１３のうちの１つでも設計値からの位置ずれがあると推力リップルが発生することが分かる。本実実施形態においては、寸法Ｌ１と寸法Ｌ２とがほぼ同一であるコイル１３のみからコイル列１４を構成し、且つ各々のコイル１３についてコイル中心Ｃに対する第１極中心Ｃ１と第２極中心Ｃ２との位置関係が同じになるように配列している。この結果、全てのコイル１３が同じように位置ずれした状態で配列される。
【００３４】
全てのコイル１３が同じように位置ずれした状態において、三相のコイル１３の全てが位相ｔ°の分だけ位置ずれして配置された場合に発生する推力について説明する。かかる場合には、各相のコイル１３の極中心に形成される電界Ｂｕ，Ｂｖ，Ｂｗ及び各相のコイル１３に印加される電流Ｉｕ，Ｉｖ，Ｉｗは以下の（３）式で表される。

【００３５】
また、このとき三相のコイル１３により生ずる推力の合成推力Ｆは以下の（４）式で表される。
Ｆ＝１．５・ｃｏｓ（ｔ） ……（４）
上記（４）式を参照すると、変数αを含む項がないため推力リップルが全く発生しないことが分かる。このことから、コイル１３を設計値通りに製造できなくとも、コイル中心Ｃと第１極中心Ｃ１との寸法Ｌ１又はコイル中心Ｃと第２極中心Ｃ２との寸法Ｌ２とがほぼ同じものを選別（分類）し、コイル中心Ｃに対する第１極中心Ｃ１と第２極中心Ｃ２との位置関係が同じになるように配列すれば推力リップルを皆無又は極めて低減することができる。
【００３６】
以上説明したように、コイル列１４をなす全てのコイルについて寸法Ｌ１と寸法Ｌ２とがほぼ同じものを用い、上記の配列をすることによって推力リップルを低減することができる。しかしながら、リニアモータが長尺化し、コイル１３を多数必要とする場合には、寸法Ｌ１と寸法Ｌ２とがほぼ同じコイル１３を必要な数だけ用意することが困難な場合がある。この場合には隣接するＵ相、Ｖ相、Ｗ相のコイル１３を一組として、コイル組毎に第１寸法Ｌ１と第２寸法Ｌ２とがほぼ同じコイル１３を選別（分類）し（コイル組とする段階）、コイル組を配列してコイル列１４とすれば良い（配列する段階）。
【００３７】
この構成においては、１つのコイル組に含まれる３つのコイル１３については第１寸法Ｌ１と第２寸法Ｌ２とがほぼ同じであるが、コイル組の間では第１寸法Ｌ１と第２寸法Ｌ２とが異なってしまう。しかしながら、結果的に各相の磁界に対する位相ずれは同じものとなるため、上記（３）式に示した状況と同様となり、その結果として推力リップルの発生を低減することができる。
【００３８】
また、例えばコイル１３の第１寸法Ｌ１と第２寸法Ｌ２とのずれが大きく、ほぼ同じものが得られない場合も考えられる。この場合には、コイル１３を組み合わせ配列してコイル列１４とした後の最終的な各相の磁界に対する位相ずれが同じになるように予め組み合わせておけば、上記（３）式に示した状況と同様となる。尚、上述したコイル組毎に第１寸法Ｌ１と第２寸法Ｌ２とがほぼ同じコイル１３を選別（分類）してコイル列１４を形成する方法、及び、最終的な各相の磁界に対する位相ずれが同じになるように予め組み合わせてコイル列１４を形成する方法は、コイル列１４に含まれるコイル１３の数が多い場合に、リニアモータ装置の製造が容易になり、しかも推力リップルの発生を低減することができる。
【００３９】
以上、コイル中心Ｃと第１極中心Ｃ１との間の寸法Ｌ１とコイル中心Ｃと第２極中心Ｃ２との間の寸法Ｌ２との関係、及びコイル中心Ｃに対する第１極中心Ｃ１と第２極中心Ｃ２との位置関係に着目して推力リップルを低減する方法について説明したが、コイル列１４をなす各相のコイル１３に供給する電流の位相関係を制御することによっても推力リップルの発生を低減することができる。
【００４０】
いま、図５を用いて説明した状況、つまりＶ相及びＷ相のコイル１３は設計値通り配置されているが、Ｕ相のコイル１３のみが位相ｔ°の分だけ位置ずれして配置されている状況を考える。この状況において、Ｕ相にコイル１３に印加する電流Ｉｕの位相をＵ相のコイル１３のずれ方とは逆となる方向にｔ°だけ遅らせると、各相のコイル１３の極中心に形成される電界Ｂｕ，Ｂｖ，Ｂｗ及び各相のコイル１３に印加される電流Ｉｕ，Ｉｖ，Ｉｗは以下の（５）式で表される。

【００４１】
また、このとき三相のコイル１３により生ずる推力の合成推力Ｆは以下の（６）式で表される。
Ｆ＝１．５−ｓｉｎ（ｔ）・ｓｉｎ（ｔ） ……（６）
上記（６）式を参照すると、変数αを含む項がないため推力リップルが全く発生しないことが分かる。このことから、コイル列１４を製造する上で、寸法Ｌ１と寸法Ｌ２とがほぼ同一のものがなく、コイル中心Ｃに対する第１極中心Ｃ１と第２極中心Ｃ２との位置関係を前述した通り設定することができなくとも、コイル１３の位置ずれ量に応じて電流制御を行うことで推力リップルの発生を皆無に又は低減することができる。
【００４２】
尚、以上の電流制御はＵ相のみに適用することができるわけではなく、コイル１３の位置ずれに応じてＶ相、Ｗ相にも適用することができる。また、複数の相のコイル１３の位置ずれが生じていても各々の相の位置ずれ量に応じて個々の相の電流制御を個別に行うことで推力リップルの発生を低減させることができる。各々の相の位相ずれは、各相の推力定数を計測することで容易に得ることができる。
【００４３】
以上、コイル１３の製造誤差及び配列誤差に起因して生ずる推力リップルを、コイル１３の位置関係等を調整し、又はコイル１３に供給する電流制御を行うことで低減する方法について説明した。以上の説明においては、磁石列２４，２５によって形成される磁界が正弦波状であることを前提としたが、この磁界の磁束密度がｙ方向の位置に応じて変化していても推力リップルが発生することがある。
【００４４】
いま、Ｕ相、Ｖ相、及びＷ相のコイル１３が全て設計値通りに配置されている場合を考える。この場合において、磁石列２４，２５がＵ相のコイル１３に対して形成する磁束密度が他の相のコイル１３に対して形成する磁束密度よりもＲだけ大きいとする。このときに各相のコイル１３の極中心に形成される電界Ｂｕ，Ｂｖ，Ｂｗ及び各相のコイル１３に印加される電流Ｉｕ，Ｉｖ，Ｉｗは以下の（７）式で表される。

【００４５】
このとき三相のコイル１３により生ずる推力の合成推力Ｆは以下の（８）式で表される。
Ｆ＝１．５＋Ｒ・（０．５・（１−ｃｏｓ（２α））） ……（８）
上記（８）式から合成推力Ｆには２αの周期を有する推力リップルが含まれることが分かる。このことから、推力リップルを低減するためには、磁石列２４，２５が各相のコイル１３に形成する磁界の大きさの最大値を一定にすることも必要となる。
【００４６】
可動子１２の製造上の都合から磁石列２４，２５が各相のコイル１３に形成する磁界の大きさの最大値を一定にすることが困難な場合には、磁石列２４，２５が形成する磁界の大きさのばらつきに応じて、各相のコイル１３に流す電流の大きさを変化させる電流制御を行えば推力リップルの発生を抑えることができる。
【００４７】
まず、Ｕ相、Ｖ相、及びＷ相のコイル１３が全て設計値通りに配置されているとし、この場合において、磁石列２４，２５がＵ相のコイル１３に対して形成する磁束密度が他の相のコイル１３に対して形成する磁束密度よりもＲだけ大きいとする。また、Ｕ相のコイル１３に対して大きさをＲだけ減じた電流を流すとすると、各相のコイル１３の極中心に形成される電界Ｂｕ，Ｂｖ，Ｂｗ及び各相のコイル１３に印加される電流Ｉｕ，Ｉｖ，Ｉｗは以下の（９）式で表される。

【００４８】
このとき三相のコイル１３により生ずる推力の合成推力Ｆは以下の（１０）式で表される。
Ｆ＝１．５＋Ｒ・Ｒ・（０．５・（１−ｃｏｓ（２α））） ……（１０）
上記（１０）式を参照すると電流制御を行ったにもかかわらず依然として合成推力Ｆには２αの周期を有する推力リップルが含まれている。しかしながら、推力リップルの発生を示す（１０）式の右辺第２項にはＲの２乗が掛かっている。上述したように、Ｒは磁界の大きさの最大値のずれ量を示しており、その値は通常数％程度である。このため（１０）式の右辺第２項は右辺第１項に比べて極めて小さな値となってリニアモータ装置の精度上問題ない値となる。
【００４９】
以上、コイル１３の製造誤差及び配列誤差に起因して生ずる推力リップルを低減する方法として、コイル１３の位置関係等を調整する方法、又はコイル１３に供給する電流の位相を制御する電流制御を行うことで低減する方法について説明した。また、磁石列２４，２５が形成する磁界の大きさのばらつきに起因して生ずる推力リップルを低減する方法として、形成する磁界の大きさの最大値がほぼ同一である磁石２４，２５のみから磁石列２４，２５を形成する方法、又は磁石列２４，２５が形成する磁界の大きさのばらつきに応じてコイル１３に供給する電流の大きさを制御する電流制御を行うことで低減する方法について説明した。
【００５０】
これらの方法を個別に適用して推力リップルを低減しても良いが、複合的な原因で推力リップルが発生する場合には、上記の方法を組み合わせて適用しても良い。更に、上記の実施形態においては、ムービングマグネット型のリニアモータ装置を例に挙げて説明したが、もちろんムービングコイル型のリニアモータ装置にも適用することが可能である。
【００５１】
〔ステージ装置〕
以上、本発明の実施形態によるリニアモータ装置について説明したが、次に以上説明した一実施形態によるリニアモータ装置を備えるステージ装置について説明する。図６は、本発明の一実施形態によるリニアモータ装置を備えるステージ装置及びその制御装置を示す図である。尚、ここでは、ウェハ（半導体ウェハ）Ｗを水平面内で移動させるステージ装置について説明する。また、ウェハＷが移動する水平面内に互いに直交するＸ軸及びＹ軸を設定して説明を進める。
【００５２】
図６に示すように、ステージ制御装置は、上位コントローラ３１、制御コントローラ３２、電流増幅部３３ａ〜３３ｃ、及び位置検出部３４ａ，３４ｂを含み、被制御対象としてのステージ装置３５を制御する。上位コントローラ３１は、制御コントローラ３２に対してＸＹ面内におけるウェハＷの位置を指示する制御信号を出力する。
【００５３】
制御コントローラ３２は、上位コントローラ３１から出力される制御信号と後述する位置検出部３４ａ，３４ｂから出力される検出信号とに基づいて、ステージ装置３５が備えるリニアモータ４０〜４２を駆動するための駆動信号を生成し、ウェハＷを載置するステージとしてのウェハステージ３６の動作を制御する。尚、制御コントローラ３２は本発明にいう電流供給部に相当し、前述した各相のコイル１３に供給する電流の位相を制御する電流制御、又は電流の大きさを制御する電流制御を行う。
【００５４】
電流増幅部３３ａ〜３３ｃは、制御コントローラ３２から出力される駆動信号の電流を所定の増幅率で増幅してステージ装置３５に設けられるリニアモータ４０〜４２にそれぞれ供給する。位置検出部３４ａ，３４ｂは、ウェハステージ３６のＸ方向の位置及びＹ方向の位置（ステージ位置）を検出する。
【００５５】
次に、ステージ装置３５について詳細に説明する。図７は、ステージ装置３５の構成例を示す斜視図である。図６及び図７に示すように、ステージ装置３５は、ウェハステージ３６、このウェハステージ３６をＸＹ平面に沿った２次元方向に移動可能に支持するウェハ定盤３７、ウェハステージ３６と一体的に設けられウェハＷを吸着保持する試料台３８、これらウェハステージ３６及び試料台３８を相対移動自在に支持するＸガイドバー３９を主体に構成されている。ウェハステージ３６の底面には、非接触ベアリングである不図示の複数のエアベアリング（エアパッド）が固定されており、これらのエアベアリングによってウェハステージ３６がウェハ定盤３７上に、例えば数ミクロン程度のクリアランスを介して浮上支持されている。
【００５６】
ウェハ定盤３７は、例えば不図示のベースプレートの上方に、不図示の防振ユニットを介してほぼ水平に支持されている。ここで、防振ユニットは、例えばウェハ定盤３７の各コーナーに配置され、内圧が調整可能なエアマウントとボイスコイルモータとがベースプレート上に並列に配置された構成になっている。これらの防振ユニットによって、ベースプレートを介してウェハ定盤３７に伝わる微振動がマイクロＧレベルで絶縁されるようになっている。
【００５７】
また、図７に示すように、Ｘガイドバー３９は、Ｘ方向に沿った長尺形状を呈しており、その長さ方向の両端には電機子ユニットからなる可動子４０ａ及び可動子４１ａがそれぞれ設けられている。これらの可動子４０ａ，４１ａにそれぞれ対応する磁石ユニットを有する固定子４０ｂ，４１ｂは、不図示のベースプレートに突設された支持部に設けられている。
【００５８】
上記の可動子４０ａ及び固定子４０ｂによってリニアモータ４０が構成され、可動子４１ａ及び固定子４１ｂによってリニアモータ４１が構成されている。可動子４０ａが固定子４０ｂとの間の電磁気的相互作用により駆動され、なおかつ可動子４１ａが固定子４１ｂとの間の電磁気的相互作用により駆動されることでＸガイドバー３９がＹ方向に移動し、リニアモータ４０とリニアモータ４１との駆動量を調整することで、ウェハステージ３６はＸ軸及びＹ軸に直交するＺ軸周りに回転する。即ち、リニアモータ４０，４１によってＸガイドバー３９とほぼ一体的にウェハステージ３６（及び試料台３８）がＹ方向及びＺ軸周りに駆動されるようになっている。
【００５９】
また、Ｘガイドバー３９のＸ方向側には、Ｘトリムモータ４３の可動子が取り付けられている。このＸトリムモータ４３は、Ｘ方向に推力を発生することでＸガイドバー３９のＸ方向の位置を調整するものであって、その固定子は不図示のリアクションフレームに設けられている。このため、ウェハステージ３６をＸ方向に駆動する際の反力は、リアクションフレームを介してベースプレートに伝達される機能になっている。
【００６０】
試料台３８は、Ｘガイドバー３９との間にＺ方向に所定量のギャップを維持する磁石及びアクチュエータからなる磁気ガイドを介して、Ｘガイドバー３９にＸ方向に相対移動自在に非接触で支持・保持されている。また、ウェハステージ３６は、Ｘガイドバー３９に埋設された固定子を有するリニアモータ４２による電磁気的相互作用によりＸ方向に駆動される。リニアモータ４２の可動子は図示していないが、ウェハステージ３６に取り付けられている。試料台３８の上面には、不図示のウェハホルダを介してウェハＷが真空吸着等によって固定される。
【００６１】
尚、上記リニアモータ４０，４１よりもリニアモータ４２の方がウェハステージ３６上に載置されるウェハＷに近い位置に配置されており、リニアモータ４２の可動子が試料台３８に固定されている。このため、リニアモータ４２は発熱源であるコイルが固定子となりウェハＷから遠ざかり直接試料台３８に固定されないムービングマグネット型のリニアモータを用いることが望ましい。
【００６２】
リニアモータ４０，４１は、リニアモータ４２、Ｘガイドバー３９、及び試料台３８を一体として駆動するため、Ｘリニアモータ４２より遙かに大きい推力を必要とする。そのため、多くの電力を必要とし発熱量もリニアモータ４２より大きくなる。従って、リニアモータ４０，４１は、ムービングコイル型のリニアモータを用いることが望ましい。しかしながら、ムービングコイル型のリニアモータは可動子４０ａ，４１ａに冷媒を循環させる必要があるため、装置構成上の不具合がある場合には、可動子４０ａ，４１ａ側にマグネットを設けるムービングマグネット型のリニアモータを用いても良い。
【００６３】
また、ウェハステージ３６端部にはＸ方向に延びる移動鏡４４とＹ方向に延びる移動鏡４５が取り付けられている。これらの移動鏡４４，４５の鏡面に対面する位置にレーザ干渉計４６，４７（図１参照）がそれぞれ取り付けられており、ウェハステージ３６のＸ方向の位置及びＹ方向の位置が所定の分解能、例えば０．５〜１ｎｍ程度の分解能でリアルタイムに計測される。尚、レーザ干渉計４６，４７の少なくとも一方は、測長軸を２軸以上有する多軸干渉計であり、これらレーザ干渉計の計測値に基づいてウェハステージ３６（ひいてはウェハＷ）のＸ方向の位置及びＹ方向の位置のみならず、Ｚ軸周りの回転量及びレベリング量をも求めることができるようになっている。
【００６４】
以上の構成のステージ装置においては、リニアモータ４０〜４２の固定子１１及び可動子１２の何れか一方に設けられたコイル列１４が前述したコイル１３の位置関係等を調整する方法を用いて製造されており、他方に設けられた磁石列２４，２５が前述した磁界の大きさの最大値がほぼ同一である磁石２４，２５のみから形成されている場合には、制御コントローラ３２は通常の制御を行う。つまり、リニアモータ４０〜４２の各々に設けられるコイル列１４をなす各相のコイル１３に対して相間で１２０°の位相差を有する電流であって、電流の大きさが一定の電流を予め設定されたシーケンスに従って供給する。
【００６５】
これに対し、リニアモータ４０〜４２の固定子１１及び可動子１２の何れか一方に設けられたコイル列１４を構成するコイル１３に位置誤差等があり、磁石列２４，２５をなす磁石１８，２０それぞれによって形成される磁界の大きさの最大値が同一でない場合には、前述した各相のコイル１３に供給する電流の位相を制御する電流制御、又は電流の大きさを制御する電流制御を行いつつリニアモータ４０〜４２の各々を駆動制御する。
【００６６】
〔露光装置〕
次に、露光装置について詳細に説明する。図８は、露光装置の概略構成を示す図である。図８に示す露光装置は、投影光学系ＰＬに対してマスクとしてのレチクルＲと感光基板としてのウェハＷとを相対的に移動させつつ、レチクルＲに形成されたパターンをウェハＷに転写して半導体素子を製造するステップ・アンド・スキャン方式の露光装置に適用した場合を例に挙げて説明する。
【００６７】
尚、以下の説明においては、図８中に示したＸＹＺ直交座標系を設定し、このＸＹＺ直交座標系を参照しつつ各部材の位置関係について説明する。ＸＹＺ直交座標系は、Ｘ軸及びＹ軸がウェハＷに対して平行となるよう設定され、Ｚ軸がウェハＷに対して直交する方向に設定されている。図中のＸＹＺ座標系は、実際にはＸＹ平面が水平面に平行な面に設定され、Ｚ軸が鉛直上方向に設定される。また、本実施形態ではレチクルＲ及びウェハＷを移動させる方向（走査方向ＳＤ）をＹ方向に設定している。
【００６８】
図８において、露光光源８１としては断面が略長方形状の平行光束である露光光ＩＬを射出するＡｒＦエキシマレーザ光源（波長１９３ｎｍ）が用いられる。露光光源８１からの波長１９３ｎｍの紫外パルスよりなる露光光ＩＬ（露光ビーム）は、ビームマッチングユニット（ＢＭＵ）８２を通り、光アッテネータとしての可変減光器８３に入射する。可変減光器８３を通った露光光ＩＬは、レンズ系８４ａ，８４ｂよりなるビーム成形系８５を経て第１段のオプティカル・インテグレータ（ユニフォマイザ、又はホモジナイザ）としての第１フライアイレンズ８６に入射する。この第１フライアイレンズ８６から射出された露光光ＩＬは、第１レンズ系８７ａ、光路折り曲げ用のミラー８８、及び第２レンズ系８７ｂを介して第２段のオプティカル・インテグレータとしての第２フライアイレンズ８９に入射する。
【００６９】
第２フライアイレンズ８９の射出面、即ち露光対象のレチクルＲのパターン面に対する光学的なフーリエ変換面（照明系の瞳面）には開口絞り板９０が、駆動モータ９０ｅによって回転自在に配置されている。開口絞り板９０には、通常照明用の円形の開口絞り９０ａ、輪帯照明用の開口絞り９０ｂ、及び複数（例えば４極）の偏心した小開口よりなる変形照明用の開口絞り（不図示）や小さいコヒーレンスファクタ（σ値）用の小円形の開口絞り（不図示）等が切り換え自在に配置されている。露光装置の全体の動作を統括制御する主制御系１０３が駆動モータ９０ｅを介して開口絞り板９０を回転させて、照明条件を設定する。
【００７０】
尚、変形照明（輪帯照明、４極照明等）を行うときに、露光光ＩＬの利用効率を高めて高い照度（パルスエネルギー）を得るには、露光光ＩＬが第２フライアイレンズ８９に入射する段階で、露光光ＩＬの断面形状をほぼ輪帯形状に整形しておくことが望ましい。このためには、第１フライアイレンズ８６を例えば多数の位相型の回折格子の集合体よりなる回折光学格子（Ｄｉｆｆｒａｃｔｉｖｅ Ｏｐｔｉｃａｌ Ｅｌｅｍｅｎｔ：ＤＯＥ）で置き換えればよい。また、照明条件切り換え系は上記の構成に限られるものではなく、開口絞り板９０に組み合わせて又は単独で円錐プリズム（アキシコン）及び／又はズーム光学系と、回折光学素子とを用いるようにしても良い。尚、第２段のオプティカル・インテグレータとして内面反射型インテグレータ（ロッドインテグレータ等）を用いる場合には、例えばＤＯＥ、円錐プリズム、又は多面体プリズム等を用いて、照明系の光軸ＩＡＸに関して露光光ＩＬを傾けて内面反射型インテグレータに入射させるとともに、照明条件に応じてその入射面での露光光ＩＬの入射角度範囲を変更することが望ましい。
【００７１】
図８において、第２フライアイレンズ８９から射出されて通常照明用の開口絞り９０ａを通過した露光光ＩＬは、光軸ＩＡＸに沿ってレンズ系９１，９２を順次経て、固定ブラインド（固定照明視野絞り）９３ａ及び可動ブラインド（可動照明視野絞り）９３ｂに入射する。固定ブラインド９３ａは、例えば特開平４−１９６５１３号公報及び対応する米国特許題５，４７３，４１０号に開示されているように、後述する投影光学系ＰＬの円形視野内の中央で走査露光方向と直交した方向に直線スリット状、又は矩形状（以下、まとめて「スリット状」という）に伸びるように配置された開口部を有する。
【００７２】
可動ブラインド９３ｂは、ウェハＷ上の各ショット領域への走査露光の開始時及び終了時に不要な露光を防止するために、照明視野領域の走査方向の幅を可変とするために使用される。また、走査方向と直交した方向（非走査方向）に関してレチクルＲのバターン領域のサイズを可変するために使用される。固定ブラインド９３ａ及び可動ブラインド９３ｂは、レチクルＲのパターンが形成されている面（以下、レチクル面という）に対する共役面に設置されている。
【００７３】
露光時に固定ブラインド９３ａ及び可動ブラインド９３ｂを通過した露光光ＩＬは、光路折り曲げ用のミラー９４、結像用のレンズ系９５、コンデンサレンズ９６、及び主コンデンサレンズ系９７を介して、マスクとしてのレチクルＲのパターン面（下面）の照明領域（照明視野領域）ＩＲを照明する。
【００７４】
露光光ＩＬのもとで、レチクルＲの照明領域ＩＲ内の回路パターンの像が両側テレセントリックな投影光学系ＰＬを介して所定の投影倍率β（βは例えば１／４又は１／５等）で、投影光学系ＰＬの結像面に配置された基板としてのウェハＷ上のフォトレジスト層のスリット状の露光領域ＩＷに転写される。本実施形態の投影光学系ＰＬは、ジオプトリック系（屈折系）であるが、カタジオプトリック系（反射屈折系）や反射系も使用できることはいうまでもない。
【００７５】
また、レチクルＲは、マスクステージとしてのレチクルステージ９８上に吸着保持され、レチクルステージ９８は、レチクルベース９９上でＹ方向に等速移動できると共に、Ｘ方向、Ｙ方向、回転方向に傾斜できるように載置されている。レチクルステージ９８の一端には移動鏡１００が取り付けられており、移動鏡１００の鏡面に対面してレーザ干渉計１０１が設けられている。このレーザ干渉計１０１によってレチクルステージ９８（レチクルＲ）の２次元的な位置及び回転角がリアルタイムに計測されている。このレーザ干渉計１０１の計測結果及び主制御系１０３からの制御情報に基づいて、駆動制御ユニット１０２がレチクルステージ９８の走査速度、及び位置の制御を行う。
【００７６】
一方、ウェハＷは、ウェハホルダ１０４を介して基板ステージとしてのウェハステージ１０５上に吸着保持され、ウェハステージ１０５は、ウェハベース１０６上で投影光学系ＰＬの像面と平行なＸＹ平面に沿って２次元移動する。即ち、ウェハステージ１０５は、ウェハベース１０６上でＹ方向に一定速度で移動すると共に、Ｘ方向、Ｙ方向にステップ移動する。更に、ウェハステージ１０５には、ウェハＷのＺ方向の位置（フォーカス位置）、並びにＸ軸及びＹ軸の回りの傾斜角を制御するＺレベリング機構も組み込まれている。
【００７７】
また、図示は省略しているが、投影光学系ＰＬの側面に、ウェハＷの表面（ウェハ面）の複数の計測点に斜めにスリット像を投影する投射光学系と、そのウェハ面からの反射光を受光してそれらの複数の計測点のフォーカス位置に対応するフォ−カス信号を生成する受光光学系とからなる多点のオートフォーカスセンサも設けられており、それらのフォ−カス信号が主制御系１０３中の合焦制御部に供給されている。走査露光時には、主制御系１０３中の合焦制御部は、それらのフォーカス信号（フォーカス位置）の情報に基づいてオートフォーカス方式でウェハステージ１０５中のＺレベリング機構を連続的に駆動する。これによって、ウェハＷの表面が投影光学系ＰＬの像面に合焦される。
【００７８】
ウェハステージ１０５の一端には移動鏡１０７が取り付けられており、移動鏡１０７の鏡面に対面してレーザ干渉計１０８が設けられている。このレーザ干渉計１０８によってウェハステージ１０５のＸ方向、Ｙ方向の位置、及びＸ軸、Ｙ軸、Ｚ軸の回りの回転角がリアルタイムに計測されている。レーザ干渉計１０８の計測結果及び主制御系１０３からの制御情報に基づいて、駆動制御ユニット１０９がウェハステージ１０５の走査速度、及び位置の制御を行う。尚、図８中のウェハステージ１０５は、図６及び図７に示したステージ装置３５に相当するものであり、駆動制御ユニット１０９内に図６に示した制御コントローラ３２、位置検出部３４ａ，３４ｂ、及び電流増幅部３３ａ〜３３ｃが設けられている。また、移動鏡１０７は図７に示した移動鏡４４，４５に相当し、レーザ干渉計１０８は図６に示したレーザ干渉計４６，４７に相当する。
【００７９】
主制御系１０３は、レチクルステージ９８及びウェハステージ１０５のそれぞれの移動位置、移動速度、移動加速度、位置オフセット等の各種情報を駆動制御ユニット１０２，１０９に送る。これに応じて、レチクルステージ９８を介して露光光ＩＬの照明領域ＩＲに対してレチクルＲが＋Ｙ方向（又は−Ｙ方向）に速度Ｖｒで走査されるのに同期して、ウェハステージ１０５を介してレチクルＲのパターン像の露光領域ＩＷに対してウェハＷが−Ｙ方向（又は＋Ｙ方向）に速度β・Ｖｒ（βはレチクルＲからウェハＷへの投影倍率）で走査される。この際の走査露光の開始時及び終了時に不要な部分への露光を防止するために、可動ブラインド９３ｂの開閉動作が制御される。レチクルＲとウェハＷとの移動方向が逆であるのは、本実施形態の投影光学系ＰＬが反転投影を行うためである。
【００８０】
次に、以上説明した構成の露光装置の露光時の動作について簡単に説明する。露光動作が開始されると、主制御系１０３から駆動制御ユニット１０２，１０９へ制御信号が出力され、駆動制御ユニット１０２，１０９はレチクルステージ９８及びウェハステージ１０５の加速度を上昇させる。駆動制御ユニット１０９は、主制御系１０３から出力される制御信号（目標位置信号）とレーザ干渉計１０８から出力される検出信号とに基づいてウェハステージ１０５を加速してウェハＷの露光すべきショット領域を露光開始位置へ移動させる。このとき、レチクルステージ９８又はウェハステージ１０５の移動に合わせて前述した反力処理を行う。尚、レチクルステージ９８についてもウェハステージ１０５と同様に加速動作が行われる。
【００８１】
加速期間が終了して、ウェハステージ１０５及びレチクルステージ９８各々の速度が一定の速度になると、スリット状の照明光をレチクルＲに照射しつつ、ウェハステージ１０５を−Ｙ方向に速度Ｖｗ（＝β・Ｖｍ）で走査移動するとともに、レチクルステージユニットを＋Ｙ方向に速度Ｖｍで走査移動しつつ、レチクルに形成されたパターンを、投影光学系ＰＬを介してウェハＷ上に設定されたショット領域に転写する。１つのショット領域に対してレチクルのパターンの転写が終了すると、ウェハステージ１０５及びレチクルステージ９８を減速させて、レチクルＲへの照明光の照射を停止させる。
【００８２】
次に、主制御系１０３は、ウェハステージ１０５を駆動して、次にパターンを転写するショット領域を投影光学系ＰＬの投影領域（レチクルＲのパターンが投影される領域）の近傍（露光開始位置）に移動させる。このときもウェハステージ１０５の移動に応じて生ずる反力を相殺する反力処理を行う。そして、上述した動作と同様に、ウェハステージ１０５及びレチクルステージ９８を加速して一定速度になった後、照明光をレチクルＲに照射して、レチクルのパターンをショット領域に逐次転写する。図９は、パターン転写時における投影領域に対するウェハＷの移動経路の一例を示す図である。この図に示すように、ショット領域ＳＡにレチクルＲのパターンを転写する際には、ウェハＷをＹ方向（＋Ｙ方向又は−Ｙ方向）に沿って一定速度で移動させる。一方、１つのショット領域に対する露光処理が終了し、次に露光処理すべきショット領域の露光開始位置に移るときには、加速及び減速しつつＸ方向（または、Ｙ方向）にステップ移動する。このような動作を繰り返して、ウェハＷ上に設定された全てのショット領域に対する露光処理を行う。
【００８３】
以上、本発明の実施形態について説明したが、本発明は上記実施形態に制限されず、本発明の範囲内で自由に変更が可能である。例えば、上記実施形態では露光光源８１として、ＡｒＦエキシマレーザ光源の場合を例に挙げて説明したが、これ以外に露光光源８１としては、例えばｇ線（波長４３６ｎｍ）、ｉ線（波長３６５ｎｍ）を射出する超高圧水銀ランプ、又はＫｒＦエキシマレーザ（波長２４８ｎｍ）、ＡｒＦエキシマレーザ（波長１９３ｎｍ）、Ｆ_２エキシマレーザ（波長１５７ｎｍ）、Ｋｒ_２レーザ（波長１４６ｎｍ）、ＹＡＧレーザの高周波発生装置、若しくは半導体レーザの高周波発生装置を用いることができる。
【００８４】
更に、光源としてＤＦＢ半導体レーザ又はファイバーレーザから発振される赤外域、又は可視域の単一波長レーザ光を、例えばエルビウム（又はエルビウムとイットリビウムの両方）がドープされたファイバーアンプで増幅し、非線形光学結晶を用いて紫外光に波長変換した高調波を用いても良い。例えば、単一波長レーザの発振波長を１．５１〜１．５９μｍの範囲内とすると、発生波長が１８９〜１９９ｎｍの範囲内である８倍高調波、又は発生波長が１５１〜１５９ｎｍの範囲内である１０倍高調波が出力される。
【００８５】
特に、発振波長を１．５４４〜１．５５３μｍの範囲内とすると、発生波長が１９３〜１９４ｎｍの範囲内の８倍高調波、即ちＡｒＦエキシマレーザ光とほぼ同一波長となる紫外光が得られ、発振波長を１．５７〜１．５８μｍの範囲内とすると、発生波長が１５７〜１５８ｎｍの範囲内の１０倍高調波、即ちＦ_２レ−ザ光とほぼ同一波長となる紫外光が得られる。また、発振波長を１．０３〜１．１２μｍの範囲内とすると、発生波長が１４７〜１６０ｎｍの範囲内である７倍高調波が出力され、特に発振波長を１．０９９〜１．１０６μｍの範囲内とすると、発生波長が１５７〜１５８μｍの範囲内の７倍高調波、即ちＦ_２レーザ光とほぼ同一波長となる紫外光が得られる。この場合、単一波長発振レーザとしては例えばイットリビウム・ドープ・ファイバーレーザを用いることができる。
【００８６】
また、本発明は半導体素子の製造に用いられる露光装置だけではなく、液晶表示素子（ＬＣＤ）等を含むディスプレイの製造に用いられてデバイスパターンをガラスプレート上へ転写する露光装置、薄膜磁気ヘッドの製造に用いられてデバイスパターンをセラミックウェハ上へ転写する露光装置、及びＣＣＤ等の撮像素子の製造に用いられる露光装置等にも適用することができる。更には、光露光装置、ＥＵＶ露光装置、Ｘ線露光装置、及び電子線露光装置などで使用されるレチクル又はマスクを製造するために、ガラス基板又はシリコンウェハなどに回路パターンを転写する露光装置にも本発明を適用できる。ここで、ＤＵＶ（遠紫外）光やＶＵＶ（真空紫外）光などを用いる露光装置では一般的に透過型レチクルが用いられ、レチクル基板としては石英ガラス、フッ素がドープされた石英ガラス、蛍石、フッ化マグネシウム、又は水晶などが用いられる。また、プロキシミティ方式のＸ線露光装置、又は電子線露光装置などでは透過型マスク（ステンシルマスク、メンブレンマスク）が用いられ、マスク基板としてはシリコンウェハなどが用いられる。
【００８７】
また、本発明のステージ制御装置は、露光装置に設けられるウェハステージの移動動作を制御するのみならず、レチクルステージの移動動作を制御するために用いても良い。更に、本発明は露光装置のみならず、物体を載置した状態で移動させる（１次元的な移動又は２次元的な移動に制限されない）ステージ装置を制御する場合一般について適用することが可能である。
【００８８】
次に、本発明の一実施形態による露光装置及び露光方法をリソグラフィ工程で使用したマイクロデバイスの製造方法の実施形態について説明する。図１０は、マイクロデバイス（ＩＣやＬＳＩ等の半導体チップ、液晶パネル、ＣＣＤ、薄膜磁気ヘッド、マイクロマシン等）の製造例のフローチャートを示す図である。図１０に示すように、まず、ステップＳ１０（設計ステップ）において、マイクロデバイスの機能・性能設計（例えば、半導体デバイスの回路設計等）を行い、その機能を実現するためのパターン設計を行う。引き続き、ステップＳ１１（マスク製作ステップ）において、設計した回路パターンを形成したマスク（レチクル）を製作する。一方、ステップＳ１２（ウェハ製造ステップ）において、シリコン等の材料を用いてウェハを製造する。
【００８９】
次に、ステップＳ１３（ウェハ処理ステップ）において、ステップＳ１０〜ステップＳ１２で用意したマスクとウェハを使用して、後述するように、リソグラフィ技術等によってウェハ上に実際の回路等を形成する。次いで、ステップＳ１４（デバイス組立ステップ）において、ステップＳ１３で処理されたウェハを用いてデバイス組立を行う。このステップＳ１４には、ダイシング工程、ボンティング工程、及びパッケージング工程（チップ封入）等の工程が必要に応じて含まれる。最後に、ステップＳ１５（検査ステップ）において、ステップＳ１４で作製されたマイクロデバイスの動作確認テスト、耐久性テスト等の検査を行う。こうした工程を経た後にマイクロデバイスが完成し、これが出荷される。
【００９０】
図１１は、半導体デバイスの場合における、図１０のステップＳ１３の詳細なフローの一例を示す図である。図１１において、ステップＳ２１（酸化ステップ）においてはウェハの表面を酸化させる。ステップＳ２２（ＣＶＤステップ）においてはウェハ表面に絶縁膜を形成する。ステップＳ２３（電極形成ステップ）においてはウェハ上に電極を蒸着によって形成する。ステップＳ２４（イオン打込みステップ）においてはウェハにイオンを打ち込む。以上のステップＳ２１〜ステップＳ２４のそれぞれは、ウェハ処理の各段階の前処理工程を構成しており、各段階において必要な処理に応じて選択されて実行される。
【００９１】
ウェハプロセスの各段階において、上述の前処理工程が終了すると、以下のようにして後処理工程が実行される。この後処理工程では、まず、ステップ２５（レジスト形成ステップ）において、ウェハに感光剤を塗布する。引き続き、ステップ２６（露光ステップ）において、上で説明したリソグラフィシステム（露光装置）及び露光方法によってマスクの回路パターンをウェハに転写する。次に、ステップ２７（現像ステップ）においては露光されたウェハを現像し、ステップ２８（エッチングステップ）において、レジストが残存している部分以外の部分の露出部材をエッチングにより取り去る。そして、ステップ２９（レジスト除去ステップ）において、エッチングが済んで不要となったレジストを取り除く。これらの前処理工程と後処理工程とを繰り返し行うことによって、ウェハ上に多重に回路パターンが形成される。
【００９２】
【発明の効果】
以上説明したように、本発明によれば、中心位置一の極部分の中心位置までの第１寸法と、中心位置から他の極部分の中心位置までの第２寸法とのそれぞれがほぼ同一であるコイルを、コイルの中心位置に対する一の極部分と他の極部分との位置関係が同じになるように複数配列してコイル列を構成しているため、各々のコイルの設計値からの位置ずれが同じくなるよう配列される。推力リップルはコイル間の位置ずれに起因して生ずるものであるが、この発明では各コイルが設計値からずれて製造されている場合であってもコイル列をなすコイル全てが同じように位置ずれした状態で配置され、コイル間においてはほぼ位置ずれが生じていないため推力リップルの発生を効果的に抑止することができるという効果がある。その結果として位置決め精度及び制御性能を向上させることができるという効果がある。
また、本発明によれば、供給される交流電流の相数と等しい数のコイルを一組とし、コイル組毎に第１寸法及び第２寸法のそれぞれがほぼ同一のコイルを設けているため、結果的に個々のコイルの位置ずれは相殺されて相間の位置ずれがほぼ同一となり推力リップルの発生を効果的に抑止することができるとともに、コイル列をなす全てのコイルについて第１寸法及び第２寸法のそれぞれがほぼ同一のコイルを用意することがなくなってリニアモータ装置の製造が容易になるという効果がある。
また、本発明によれば、コイル列をなす各々のコイルの中心に対する極部分の中心位置の位置ずれに応じて、少なくとも一つの相の位相を変化させた電流をコイルに供給しているため、コイル間における位置ずれが存在する状態で各々のコイルが配置されていたとしても推力リップルの発生を効果的に抑止することができ、その結果として位置決め精度及び制御性能を向上させることができるという効果がある。
また、本発明によれば、磁石列が形成する磁束密度分布が磁石の製造誤差等の要因によりばらついていた場合であっても、コイル列に供給する交流電流の複数の相のうち少なくとも一つの相の振幅を磁石列が形成する磁場の磁束密度分布に応じて変化させるため、推力リップルを実際上無視できる程度まで軽減することができ、その結果として位置決め精度及び制御性能を向上させることができるという効果がある。
【図面の簡単な説明】
【図１】本発明の一実施形態によるリニアモータ装置の外観構成を示す斜視図である。
【図２】図１に示したリニアモータ装置の上面透視図である。
【図３】図１及び図２中のＡ−Ａ線の一部の断面矢視図である。
【図４】本発明の一実施形態によるリニアモータ装置が備えるコイル列１４を構成する１つのコイル１３を示す上面図である。
【図５】磁石によって形成される磁界とコイルの位置ずれにより生ずる推力変動を説明するための図である。
【図６】本発明の一実施形態によるリニアモータ装置を備えるステージ装置及びその制御装置を示す図である。
【図７】ステージ装置３５の構成例を示す斜視図である。
【図８】露光装置の概略構成を示す図である。
【図９】パターン転写時における投影領域に対するウェハＷの移動経路の一例を示す図である。
【図１０】マイクロデバイスの製造工程の一例を示すフローチャートである。
【図１１】半導体デバイスの場合における、図１０のステップＳ１３の詳細なフローの一例を示す図である。
【符号の説明】
１０ リニアモータ装置
１３ コイル
１３ａ 長手部分（一の極部分、極部分）
１３ｂ 長手部分（他の極部分、極部分）
１４ コイル列
３２ 制御コントローラ（電流供給部）
３６ ウェハステージ（ステージ部）
９８ レチクルステージ（マスクステージ）
１０５ ウェハステージ（基板ステージ）
Ｃ コイル中心（コイルの中心位置）
Ｃ１ 第１極中心（一の極部分の中心位置）
Ｃ２ 第２極中心（他の極部分の中心位置）
Ｌ１ 寸法（第１寸法）
Ｌ２ 寸法（第２寸法）
Ｒ レチクル（マスク）
Ｗ ウェハ（感光基板）[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a linear motor device that drives a stage that moves linearly or within a two-dimensional plane while holding an object such as a mask or a photosensitive substrate, a stage device including the linear motor device as a drive source, and an exposure apparatus. And a method for manufacturing a linear motor.
[0002]
[Prior art]
In an exposure step provided as one of manufacturing steps of a semiconductor element, a liquid crystal display element, and other microdevices, a photomask or a reticle (hereinafter, collectively referred to as a mask) is formed using an exposure apparatus. The step of transferring the fine pattern thus formed onto a semiconductor wafer, a glass plate, or the like coated with a photosensitive agent such as a photoresist (hereinafter, collectively referred to as a photosensitive substrate) is repeatedly performed.
[0003]
When transferring the pattern of the mask onto the photosensitive substrate, it is necessary to superimpose the pattern already formed on the photosensitive substrate and the pattern to be transferred with high precision with high accuracy. The substrate stage is required to move very accurately. Further, in the case where the pattern is sequentially transferred while moving the mask in accordance with the movement of the photosensitive substrate, a precise movement operation is required also for the mask stage that moves while holding the mask.
[0004]
In many cases, a linear motor device is provided as a drive source for the substrate stage (and further, a drive source for the mask stage) requiring such an extremely accurate operation. A linear motor device is a motor that generates a driving force (thrust) in a linear direction. The structure is simple, the number of parts is small, and the frictional resistance in driving is small, so the operation accuracy is high and the linear driving is more direct. Therefore, there are many advantages that the moving operation can be performed quickly.
[0005]
The basic configuration of the linear motor device includes a coil array in which coils are arranged in a straight line, and a magnet array in which magnets are arranged so that the polarity alternates in the same direction as the coil arrangement direction. The linear motor device having such a configuration generates a thrust in the coil arrangement direction by supplying a sinusoidal three-phase alternating current to the coil array, and applies the three-phase alternating current according to the relative position between the coil array and the magnet array. By switching the coils, the relative position between the coil row and the magnet row can be continuously changed along the coil arrangement direction.
[0006]
If the magnetic field formed by the above-mentioned magnet array changes sinusoidally in the coil array period along the coil array direction, applying a three-phase alternating current to the coil array will produce a constant thrust in the coil array direction. appear. However, in a linear motor device in which the magnetic flux density is increased by changing the arrangement of coils in order to simultaneously achieve high output and miniaturization, the thrust may not be constant. That is, in the magnetic field formed in this linear motor device, in addition to the fundamental component that varies with the arrangement cycle of the coils, a harmonic component that varies with a period that is a fraction of the fundamental component appears. Therefore, when a three-phase alternating current is applied to the coil array, the thrust fluctuates depending on the position due to the harmonic component of the magnetic field, and there is a problem in accurately controlling the position of the substrate stage or the wafer stage. Hereinafter, this thrust variation is referred to as “thrust ripple”.
[0007]
In order to prevent the generation of thrust ripples due to the harmonic components of the magnetic field, a technique has been devised in which the current supplied to each coil of the coil array is changed according to the harmonic components of the magnetic field formed by the magnet array. I have. For details of these techniques, refer to, for example, Patent Documents 1 and 2 below.
[0008]
[Patent Document 1]
JP 2001-190088 A
[Patent Document 2]
JP-A-7-143729
[0009]
[Problems to be solved by the invention]
By the way, as described above, in the conventional linear motor device, the current supplied to each of the coils forming the coil array is changed in accordance with the harmonic component of the magnetic field formed by the magnet array, so that the harmonic component of the magnetic field is reduced. Although the resulting thrust ripple has been suppressed, thrust ripple may still occur even if such current control is performed. This is a thrust ripple that occurs in a cycle of about half of the cycle of the magnetic pole caused by an arrangement error of the coils forming the coil array, that is, a displacement of a mounting position of each coil, or a variation in a magnetic force generated by each magnet. is there.
[0010]
These thrust ripples cannot be suppressed by the above-described conventional technology, and have been a problem in controlling the substrate stage or the mask stage. In recent years, particularly in the manufacture of semiconductor devices, there has been an increasing demand for miniaturization of process rules. In order to meet this demand, it is necessary to control the operation of a substrate stage or a stage device more precisely.
[0011]
The present invention has been made in view of the above circumstances, and a linear motor device and a linear motor manufacturing method capable of improving the positioning accuracy and control performance by effectively suppressing the occurrence of thrust ripples, and the linear motor. It is an object of the present invention to provide a stage device including a motor device and an exposure device.
[0012]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, a linear motor device according to a first aspect of the present invention is a linear motor device (10) having a coil array (14) in which a plurality of coils (13) are arranged. Each of the first dimension (L1) from the center position (C) of the coil to the center position (C1) of one pole portion (13a) contributing to thrust generation, and the other dimension (L1) contributing to thrust generation from the center position. Each of the second dimension (L2) up to the center position (C2) of the pole portion (13b) is substantially the same, and the coil row includes the one pole portion and the other pole portion with respect to the center position of the coil. The plurality of coils are arranged and configured so that the positional relationship between them is the same.
According to the present invention, a coil in which the first dimension from the center position to the center position of one pole portion and the second dimension from the center position to the center position of the other pole portion are substantially the same, A plurality of coils are arranged so that the positional relationship between one pole portion and the other pole portion with respect to the center position is the same, so that the coils are arranged so that the displacement from the design value of each coil is the same. Is done. Although thrust ripples are caused by misalignment between coils, in the present invention, even when each coil is manufactured out of design value, all coils forming a coil row are similarly misaligned. Since there is almost no displacement between the coils, the generation of thrust ripple can be effectively suppressed. As a result, positioning accuracy and control performance can be improved.
Further, in the linear motor device according to the first aspect of the present invention, an alternating current having a plurality of phases is supplied to the coil array, and the coil array includes the same number of coils as the number of phases of the alternating current. The first dimension and the second dimension are substantially the same for each coil set.
According to the present invention, the number of coils equal to the number of phases of the alternating current to be supplied is set as one set, and the first dimension and the second dimension are provided with substantially the same coil for each coil set. In addition, the positional deviations of the individual coils are canceled out, and the positional deviations between the phases become substantially the same, so that the generation of thrust ripple can be effectively suppressed, and the first dimension and the second dimension of all the coils forming the coil row are formed. There is no need to prepare substantially the same coil for each, and the manufacture of the linear motor device becomes easy.
In order to solve the above-mentioned problem, a linear motor device according to a second aspect of the present invention provides a linear motor device (10) that generates a thrust in a predetermined direction (y). A coil array (14) in which the coils (13) having the coils 13a, 13b) are arranged in the thrust direction; and an alternating current having a plurality of phases is supplied to the coil array, and at least one of the plurality of phases is supplied. And a current supply unit (32) for changing the phase of the pole portion in accordance with the displacement of the center position of the pole portion with respect to the center of the coil.
According to the present invention, a current whose phase of at least one phase is changed is supplied to the coils in accordance with the displacement of the center position of the pole portion with respect to the center of each of the coils forming the coil array. Therefore, even if each coil is arranged in a state where there is a positional deviation in, the generation of thrust ripple can be effectively suppressed, and as a result, the positioning accuracy and control performance can be improved.
Here, the current supply unit changes the phase of the alternating current supplied to the coil in which the position of the pole portion is shifted.
In the linear motor device according to the first and second aspects of the present invention, the center position of the pole portion may be the center position of the length of the pole portion along the thrust direction.
In order to solve the above-mentioned problem, a linear motor device according to a third aspect of the present invention includes a coil array (14) having a plurality of coils (13) arranged in a predetermined direction (y) and a polarity alternately. A magnet example (24, 25) in which a plurality of magnets (18, 20) are arranged in the predetermined direction so as to change, and an alternating current having a plurality of phases is supplied to the coil array, and among the plurality of phases, A current supply unit (32) for changing the amplitude of at least one phase according to the magnetic flux density distribution of the magnetic field formed by the magnet array.
According to the present invention, even when the magnetic flux density distribution formed by the magnet rows varies due to factors such as manufacturing errors of the magnets, at least one phase of the plurality of phases of the alternating current supplied to the coil rows. Since the amplitude is changed according to the magnetic flux density distribution of the magnetic field formed by the magnet row, the thrust ripple can be reduced to a practically negligible level, and as a result, positioning accuracy and control performance can be improved.
In order to solve the above-mentioned problem, a linear motor manufacturing method for manufacturing a linear motor (10) by arranging a plurality of coils (13) having pole portions (13a, 13b) contributing to thrust generation. Wherein the method further comprises the step of classifying the coils for each coil having the same position of the pole portion with respect to the center of the coil.
Further, the method of manufacturing a linear motor according to the present invention is characterized in that the method includes a step of arranging coils belonging to the same classification along a relative movement direction.
Furthermore, the method of manufacturing a linear motor according to the present invention includes the steps of combining the classified coils by the same number as the number of phases of the alternating current supplied to the linear motor to form a coil group for each of the classes; Are arranged along the direction of relative movement.
A stage device according to the present invention is characterized in that the stage section (36) is driven by any of the linear motor devices described above.
The exposure apparatus of the present invention is an exposure apparatus that transfers a pattern formed on a mask (R) to a photosensitive substrate (W), and includes a mask stage (98) on which the mask is placed, and a mask stage (98) on which the photosensitive substrate is placed. A substrate stage (105), and the stage device is provided as at least one of the mask stage and the substrate stage.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a linear motor device, a stage device, an exposure device, and a linear motor manufacturing method according to an embodiment of the present invention will be described in detail with reference to the drawings.
[0014]
[Linear motor device]
FIG. 1 is a perspective view showing an external configuration of a linear motor device according to an embodiment of the present invention, FIG. 2 is a top perspective view of the linear motor device shown in FIG. 1, and FIG. FIG. 3 is a sectional view taken along a line AA in FIG. 2. First, the configuration of the linear motor device will be outlined with reference to these drawings. In the following description, an xyz rectangular coordinate system is set, and the positional relationship of each member will be described with reference to the xyz rectangular coordinate system. In the xyz rectangular coordinate system, the y-axis is set in the direction of relative movement of the mover 12 with respect to the stator 11, and the z-axis is set in a vertically upward direction.
[0015]
The stator 11 included in the linear motor device 10 illustrated in FIG. 1 includes a coil row 14 including a plurality of coils 13 arranged along the y direction. Each coil 13 forming the coil array 14 is formed by winding a copper round wire or a flat wire into a substantially rectangular shape a predetermined number of times (for example, several tens to several hundreds). Each coil 13 has its long side portions 13a and 13b substantially parallel to the x-axis and its short side portions 13c and 13d substantially parallel to the y-axis, and its winding surface is substantially parallel to the xy plane. In other words, the direction of the magnetic field generated at the center of the coil 13 when a current flows through the coil 13 is substantially parallel to the z-axis. The material of the winding of the coil 13 is not limited to copper, and an aluminum wire may be used.
[0016]
The coil array 14 is housed in a cooling pipe 15. The cooling pipe 15 is an annular member formed of a non-magnetic SUS material and having a rectangular cross-sectional shape, into which a cooling liquid is introduced. The cooling pipe 15 is not limited to the non-magnetic SUS material, but may be formed of a non-magnetic material having a Young's modulus of about the SUS material or more. Further, it can be formed of CFRP (carbon fiber reinforced plastic).
[0017]
The cooling pipe 15 is fixed by fixing members 16 and 17 at the end in the y direction. The fixing member 16 is provided with a terminal block 16a, and each coil 13 forming a coil array 14 is connected to the terminal block 16a, and three-phase alternating current is supplied to each coil 13 via the terminal block 16a. . The inlet and outlet of the cooling liquid to the cooling pipe 15 are provided near the fixing members 16 and 17 and on the side surfaces of the cooling pipe 15.
[0018]
Next, the mover 12 included in the linear motor device 10 includes a flat upper yoke 19 on which a magnet 18 (see FIG. 2) is bonded, a flat lower yoke 21 on which a magnet 20 is bonded, and an upper yoke 19. And a support member 22, 23 for supporting the lower yoke 21 at both ends in the x direction. The coil row 14 (coil 13) and the cooling pipe 15 that constitute the stator 11 are arranged in the center gap of the mover 12.
[0019]
The magnets 18 and 20 are formed of neodymium / iron / cobalt magnets, the upper yoke 19 and the lower yoke 21 are formed of low carbon steel equivalent to SS400, and the support members 22 and 23 are formed of aluminum alloy for weight reduction. ing. In addition, as the magnets 18 and 20, in addition to the neodymium / iron / cobalt magnet, a rare earth magnet such as a samarium / cobalt magnet or a neodymium / iron / boron magnet can be used.
[0020]
As shown in FIGS. 1 and 2, the lengths of the magnets 18 and 20 in the x direction are set to be substantially the same as the lengths of the long sides 13a and 13b of the coil 13, and the polarities of the magnets 18 and 20 alternately change along the y direction. The magnet row 24 (see FIG. 2) includes a plurality of magnets 18 and a magnet row 25 includes a plurality of magnets 20. These magnet arrays 24 and 25 are arranged so that the magnet arrays 24 are positioned in the + z direction of the long sides 13a and 13b so as to overlap the long sides 13a and 13b of the coils 13 forming the coil array 14 and in the −z direction. (The magnet row 25 is positioned).
[0021]
As shown in FIG. 3, each of the magnets 18 and the magnets 20 is arranged so as to form a pair with the coil array 14 interposed therebetween (so that their positions in the y-direction coincide with each other). 20 is set so that different magnetic poles face each other. The magnet rows 24 and 25 arranged as described above are provided mainly for generating a magnetic field on the long side portions 13a and 13b of the coil 13 to generate a thrust in the y direction.
[0022]
As shown in FIG. 2, the coils 13 forming the coil array 14 are arranged in the cooling pipe 15 or the terminal block so that three-phase currents of U-phase, V-phase, and W-phase are sequentially supplied in the y-direction. It is connected at a position near 16. Further, assuming that the arrangement interval (pitch) of the coils 13 in the y direction is Pc and the arrangement interval of the magnets 18 and 20 in the y direction is Pm, the coil 13 and the magnets 18 and 20 are arranged such that 5Pm = 3Pc. Have been. As described above, the linear motor device of the present embodiment is a so-called moving magnet type linear motor device in which the stator 11 is provided with the coil (coil array) and the mover 12 is provided with the magnet (magnet array).
[0023]
Next, the configuration of the coil array 14 provided on the stator 11 will be described in detail. FIG. 4 is a top view showing one coil 13 included in the coil array 14 provided in the linear motor device according to one embodiment of the present invention. As described above, a magnetic field is formed on the long sides 13a and 13b of the coil 13 by the magnets 18 and 20 constituting the magnets 24 and 25, and a current flows through the coil 13 to generate a thrust in the y direction. That is, the long side portions 13a and 13b of the coil 13 are pole portions that contribute to thrust generation.
[0024]
Here, as shown in FIG. 4, the center position of the coil 13 in the y direction is defined as a coil center C, the center position of the long side portion 13a as one pole portion in the y direction is defined as a first pole center C1, and The center position of the long side portion 13b as the pole portion in the y direction is defined as a second pole center C2. The center position of the pole portion (pole center) is a center position of a magnetic field generated when a current flows through the pole portions 13a and 13b. Therefore, in the case of a coil made by winding a plurality of windings, the center position of the total magnetic field that is the sum of the magnetic fields generated by each winding is the true pole center, but the windings have the same density. In the coil 13 wound in the above, the center positions of the outer dimensions of the pole portions 13a and 13b in the y direction can be regarded as pole centers C1 and C2. When a plurality of coils 13 are manufactured, a dimension (first dimension) L1 between the coil center C and the first pole center C1 and a dimension (second dimension) between the coil center C and the second pole center C2. L2 varies due to manufacturing errors. If there are variations in the dimensions L1 and L2 among the plurality of coils 13 forming the coil array 14, a thrust ripple resulting from these variations will occur, which causes a problem in driving the linear motor device with high accuracy.
[0025]
In order to solve such a problem, in the present embodiment, the coil row 14 includes only the coils 13 whose dimensions L1 and L2 are substantially the same, and the first pole center C1 and the first pole center C1 with respect to the coil center C for each coil 13. The arrangement is such that the positional relationship with the two-pole center C2 is the same. That is, since it is difficult to prepare a plurality of coils 13 whose dimensions L1 and L2 are exactly as designed, the dimensions L1 and L2 are not equal to the designed values. The coils 13 which are substantially equal to each other are selected (classified) and used (classification stage). Then, for example, the coils 13 are arranged such that the relationship of dimension L1> dimension L2 is satisfied for all coils 13 (arrangement step).
[0026]
The coil row 14 thus configured deviates from the original position of the first pole center C1 or the position of the second pole center where the first pole center C1 or the second pole center C2 of each coil 13 is determined by a design value. It will be. However, since the first pole centers C1 or the second pole centers C2 of all the coils 13 are similarly displaced in the y-direction, the distance between the adjacent first pole centers C1 or the distance between the adjacent second pole centers C2 is also determined. Becomes constant. As a result, no thrust ripple occurs.
[0027]
Here, a thrust ripple caused by a positional error between the longitudinal portion 13a as the first pole portion C1 and the longitudinal portion 13b as the second pole portion of the coil 13 will be discussed. As shown in FIG. 3, in the linear motor device of the present embodiment, a sinusoidal magnetic field is formed in the y direction along a line CL in the drawing. Note that FIG. 3 shows only three coils to which U-phase, V-phase, and W-phase currents are supplied, among a plurality of coils 13 forming a coil array 14. In FIG. 3, the first pole center C1 and the second pole center C2 of the coil 13 to which the U-phase current is supplied are U1 and U2, respectively, and the first pole of the coil 13 to which the V-phase current is supplied. The center C1 and the second pole center C2 are V1 and V2, respectively, and the first pole center C1 and the second pole center C2 of the coil 13 to which the W-phase current is supplied are W1 and W2, respectively.
[0028]
At this time, the first pole center U1 and the second pole center U2 have a 180 ° phase relationship with the magnetic field formed by the magnet rows 24 and 25. The same applies to the relationship between the first pole center V1 and the second pole center V2 and the relationship between the first pole center W1 and the second pole center W2. The first pole centers U1, V1, W1 have a phase relationship of 120 ° with respect to the magnetic field, and the second pole centers U2, V2, W2 also have a phase relationship of 120 ° with the magnetic field. These relationships hold when the coils 13 are manufactured according to the design values and are arranged in the y-direction according to the design values.
[0029]
FIG. 5 is a diagram for explaining a thrust fluctuation caused by a magnetic field formed by a magnet and a displacement of a coil. First, a case is considered where the U-phase, V-phase, and W-phase coils 13 are all arranged as designed. In this case, as shown by reference numeral P1 in FIG. 5, for example, the second pole center U2 of the coil 13 is arranged at a position where the magnetic flux density becomes maximum. In this arrangement, a magnetic flux having a phase of 30 ° to 150 ° contributes to the generation of thrust in the coil 13.
[0030]
On the other hand, the V-phase and W-phase coils 13 are arranged as designed, but only the U-phase coil 13 is displaced by the phase t ° as shown by the reference symbol P2 in FIG. Consider the case where they are arranged. In this case, the electric fields Bu, Bv, Bw formed at the pole centers of the coils 13 of the respective phases and the currents Iu, Iv, Iw applied to the coils 13 of the respective phases are expressed by the following equation (1).

[0031]
In the above expression (1), α is a variable that represents the position of the pole center of the coil 13 in the y direction by the phase of the magnetic field formed by the magnet rows 24 and 25. Referring to the equation (1), the currents Iu, Iv, and Iw applied to the coils 13 of the respective phases do not have a phase shift, but the phase of the magnetic field formed at the pole center of the U-phase coil 13 is apparent. Are shifted by t °. In the above equation (1), the magnitude of the magnetic field and the magnitude of the current are normalized to "1" for simplification.
[0032]
As described with reference to FIG. 5, the combined thrust F of the thrust generated by the three-phase coil 13 is considered while considering that the magnetic field of the phase of 120 ° contributes to the thrust generation at one pole center of the coil 13. It is expressed by the following equation (2).
F = 1 + 0.5 · cos (t) + 0.5 · (cos (2α) −cos (2α + t)) (2)
[0033]
From the above equation (2), it can be seen that the combined thrust F includes a thrust ripple having a period of 2α. As described above, it can be seen that a thrust ripple is generated when even one of the coils 13 included in the coil array 14 is displaced from the design value. In the present embodiment, the coil array 14 is constituted only by the coils 13 having the substantially same dimensions L1 and L2, and the first pole center C1 and the second pole center C2 with respect to the coil center C for each coil 13. Are arranged so that the positional relationship between them is the same. As a result, all the coils 13 are arranged in a state where they are similarly displaced.
[0034]
The thrust generated when all the three-phase coils 13 are displaced by the phase t ° in a state where all the coils 13 are similarly displaced will be described. In such a case, the electric fields Bu, Bv, Bw formed at the pole centers of the coils 13 of each phase and the currents Iu, Iv, Iw applied to the coils 13 of each phase are expressed by the following equation (3). .

[0035]
At this time, the combined thrust F generated by the three-phase coils 13 is expressed by the following equation (4).
F = 1.5 · cos (t) (4)
Referring to the above equation (4), it can be seen that no thrust ripple is generated because there is no term including the variable α. From this, even if the coil 13 cannot be manufactured as designed, it is possible to select a coil having the same dimension L1 between the coil center C and the first pole center C1 or the dimension L2 between the coil center C and the second pole center C2. (Classification), and if the first pole center C1 and the second pole center C2 are arranged so as to have the same positional relationship with respect to the coil center C, the thrust ripple can be eliminated or extremely reduced.
[0036]
As described above, the thrust ripple can be reduced by using the same size L1 and the same size L2 for all the coils forming the coil array 14 and arranging them in the above-described arrangement. However, when the length of the linear motor is increased and a large number of coils 13 are required, it may be difficult to prepare a required number of coils 13 having substantially the same dimensions L1 and L2. In this case, the adjacent U-phase, V-phase, and W-phase coils 13 are set as one set, and the coils 13 whose first dimensions L1 and second dimensions L2 are substantially the same are sorted (classified) for each coil set (coil set). ), A coil group may be arranged to form the coil row 14 (arranging step).
[0037]
In this configuration, the first dimension L1 and the second dimension L2 are substantially the same for the three coils 13 included in one coil set, but between the coil sets, the first dimension L1 and the second dimension L2 are different. Will be different. However, as a result, the phase shift with respect to the magnetic field of each phase becomes the same, so that the situation is the same as the situation shown in the above equation (3), and as a result, the generation of thrust ripple can be reduced.
[0038]
In addition, for example, there may be a case where the deviation between the first dimension L1 and the second dimension L2 of the coil 13 is large and almost the same thing cannot be obtained. In this case, if the coils 13 are combined and arranged so as to have the same phase shift with respect to the final magnetic field of each phase after the coil array 14 is formed, the situation shown in the above equation (3) can be obtained. Is the same as A method of selecting (classifying) the coils 13 having substantially the same first dimension L1 and second dimension L2 for each coil group to form a coil array 14, and a final phase shift with respect to the magnetic field of each phase The method of forming the coil array 14 by combining them in advance so as to make the same is easy when the number of coils 13 included in the coil array 14 is large, the manufacture of the linear motor device becomes easy, and the generation of thrust ripple is reduced. can do.
[0039]
As described above, the relationship between the dimension L1 between the coil center C and the first pole center C1 and the dimension L2 between the coil center C and the second pole center C2, and the first pole center C1 and the second Although the method of reducing the thrust ripple has been described focusing on the positional relationship with the pole center C2, the generation of the thrust ripple can also be controlled by controlling the phase relation of the current supplied to the coils 13 of each phase forming the coil array 14. Can be reduced.
[0040]
Now, the situation described with reference to FIG. 5, that is, the V-phase and W-phase coils 13 are arranged as designed, but only the U-phase coil 13 is misaligned by the phase t °. Think about the situation. In this situation, if the phase of the current Iu applied to the coil 13 in the U-phase is delayed by t ° in a direction opposite to the direction of displacement of the coil 13 in the U-phase, the current Iu is formed at the pole center of the coil 13 in each phase. The electric fields Bu, Bv, Bw and the currents Iu, Iv, Iw applied to the coils 13 of each phase are represented by the following equation (5).

[0041]
At this time, a combined thrust F of the thrust generated by the three-phase coil 13 is expressed by the following equation (6).
F = 1.5−sin (t) · sin (t) (6)
Referring to the above equation (6), it can be seen that thrust ripple does not occur at all because there is no term including the variable α. From this, when manufacturing the coil array 14, there is no one in which the dimensions L1 and L2 are almost the same, and the positional relationship between the first pole center C1 and the second pole center C2 with respect to the coil center C is as described above. Even if it cannot be set, by performing current control in accordance with the amount of displacement of the coil 13, the generation of thrust ripple can be eliminated or reduced.
[0042]
The current control described above cannot be applied only to the U phase, but can also be applied to the V phase and the W phase in accordance with the displacement of the coil 13. Further, even if the coils 13 of a plurality of phases are misaligned, the generation of thrust ripples can be reduced by individually controlling the current of each phase according to the misalignment of each phase. The phase shift of each phase can be easily obtained by measuring the thrust constant of each phase.
[0043]
The method of reducing the thrust ripple caused by the manufacturing error and the alignment error of the coil 13 by adjusting the positional relationship of the coil 13 or controlling the current supplied to the coil 13 has been described above. In the above description, it is assumed that the magnetic field formed by the magnet rows 24 and 25 is sinusoidal. However, even if the magnetic flux density of this magnetic field changes according to the position in the y direction, thrust ripples are generated. Sometimes.
[0044]
Now, consider a case where the U-phase, V-phase, and W-phase coils 13 are all arranged as designed. In this case, it is assumed that the magnetic flux density formed by the magnet rows 24 and 25 for the U-phase coil 13 is larger by R than the magnetic flux density formed for the other phase coils 13. At this time, the electric fields Bu, Bv, Bw formed at the pole centers of the coils 13 of the respective phases and the currents Iu, Iv, Iw applied to the coils 13 of the respective phases are expressed by the following equation (7).

[0045]
At this time, the combined thrust F of the thrust generated by the three-phase coil 13 is expressed by the following equation (8).
F = 1.5 + R · (0.5 · (1-cos (2α))) (8)
From the above equation (8), it can be seen that the combined thrust F includes a thrust ripple having a period of 2α. Therefore, in order to reduce the thrust ripple, it is necessary to keep the maximum value of the magnitude of the magnetic field formed by the magnet arrays 24 and 25 in the coils 13 of each phase constant.
[0046]
When it is difficult to make the maximum value of the magnetic field formed by the magnet arrays 24 and 25 in the coils 13 of each phase constant from the manufacturing convenience of the mover 12, the magnet arrays 24 and 25 are formed. If current control is performed to change the magnitude of the current flowing through each phase coil 13 according to the variation in the magnitude of the magnetic field, the generation of thrust ripples can be suppressed.
[0047]
First, it is assumed that the U-phase, V-phase, and W-phase coils 13 are all arranged as designed, and in this case, the magnetic flux density formed by the magnet rows 24 and 25 with respect to the U-phase coil 13 is different. It is assumed that R is larger than the magnetic flux density formed with respect to the coil 13 of the phase by R. When a current whose magnitude is reduced by R is applied to the U-phase coil 13, electric fields Bu, Bv, and Bw formed at the pole centers of the coils 13 of each phase are applied to the coils 13 of each phase. The currents Iu, Iv, Iw are represented by the following equation (9).

[0048]
At this time, the combined thrust F of the thrust generated by the three-phase coil 13 is expressed by the following equation (10).
F = 1.5 + R · R · (0.5 · (1−cos (2α))) (10)
Referring to the above equation (10), the thrust ripple having a period of 2α is still included in the resultant thrust F despite the current control. However, the square of R is applied to the second term on the right side of the equation (10) indicating the generation of the thrust ripple. As described above, R indicates the amount of deviation of the maximum value of the magnetic field, and the value is usually about several percent. Therefore, the second term on the right side of the equation (10) is an extremely small value as compared with the first term on the right side, and is a value that does not cause any problem in the accuracy of the linear motor device.
[0049]
As described above, as a method of reducing the thrust ripple generated due to a manufacturing error and an arrangement error of the coil 13, a method of adjusting a positional relationship of the coil 13 or a current control for controlling a phase of a current supplied to the coil 13 is performed. The method for reducing the number of pixels has been described. As a method for reducing the thrust ripple caused by the variation in the magnitude of the magnetic field formed by the magnet arrays 24 and 25, the magnets 24 and 25 having the same maximum value of the magnitude of the formed magnetic field are used only as magnets. A description will be given of a method of forming the rows 24 and 25 or a method of reducing the current by controlling the magnitude of the current supplied to the coil 13 in accordance with the variation in the magnitude of the magnetic field formed by the magnet rows 24 and 25. did.
[0050]
These methods may be applied individually to reduce the thrust ripple, but when thrust ripples occur due to complex causes, the above methods may be combined and applied. Further, in the above-described embodiment, the moving magnet type linear motor device has been described as an example. However, it is needless to say that the present invention can be applied to a moving coil type linear motor device.
[0051]
[Stage device]
The linear motor device according to the embodiment of the present invention has been described above. Next, a stage device including the linear motor device according to the embodiment described above will be described. FIG. 6 is a diagram illustrating a stage device including a linear motor device according to an embodiment of the present invention and a control device thereof. Here, a stage device for moving a wafer (semiconductor wafer) W in a horizontal plane will be described. Further, an X axis and a Y axis that are orthogonal to each other are set in a horizontal plane on which the wafer W moves, and the description will proceed.
[0052]
As shown in FIG. 6, the stage control device includes a host controller 31, a control controller 32, current amplifiers 33a to 33c, and position detectors 34a and 34b, and controls a stage device 35 as a controlled object. The host controller 31 outputs a control signal to the control controller 32 to indicate the position of the wafer W in the XY plane.
[0053]
The control controller 32 drives the linear motors 40 to 42 included in the stage device 35 based on a control signal output from the host controller 31 and detection signals output from position detection units 34 a and 34 b described later. A signal is generated, and the operation of the wafer stage 36 as a stage on which the wafer W is mounted is controlled. The controller 32 corresponds to the current supply unit according to the present invention, and performs the above-described current control for controlling the phase of the current supplied to the coil 13 of each phase or the current control for controlling the magnitude of the current.
[0054]
The current amplifiers 33a to 33c amplify the current of the drive signal output from the controller 32 at a predetermined amplification rate and supply the amplified current to the linear motors 40 to 42 provided in the stage device 35, respectively. The position detectors 34a and 34b detect the position of the wafer stage 36 in the X direction and the position in the Y direction (stage position).
[0055]
Next, the stage device 35 will be described in detail. FIG. 7 is a perspective view illustrating a configuration example of the stage device 35. As shown in FIGS. 6 and 7, the stage device 35 includes a wafer stage 36, a wafer surface plate 37 that supports the wafer stage 36 movably in a two-dimensional direction along the XY plane, and the wafer stage 36. The apparatus mainly includes a sample stage 38 provided for sucking and holding the wafer W, and an X guide bar 39 for supporting the wafer stage 36 and the sample stage 38 so as to be relatively movable. A plurality of air bearings (air pads) (not shown), which are non-contact bearings, are fixed to the bottom surface of the wafer stage 36, and the wafer stage 36 is placed on the wafer surface 37 by, for example, several microns by these air bearings. Floating supported via clearance.
[0056]
The wafer surface plate 37 is supported substantially horizontally, for example, above a base plate (not shown) via an anti-vibration unit (not shown). Here, the anti-vibration unit is arranged, for example, at each corner of the wafer surface plate 37, and has a configuration in which an air mount whose internal pressure is adjustable and a voice coil motor are arranged in parallel on a base plate. With these vibration isolating units, micro vibrations transmitted to the wafer surface plate 37 via the base plate are insulated at the micro G level.
[0057]
As shown in FIG. 7, the X guide bar 39 has an elongated shape along the X direction, and a movable element 40a and a movable element 41a each composed of an armature unit are provided at both ends in the length direction. Is provided. The stators 40b and 41b each having a magnet unit corresponding to each of the movable elements 40a and 41a are provided on a support portion projecting from a base plate (not shown).
[0058]
The mover 40a and the stator 40b constitute a linear motor 40, and the mover 41a and the stator 41b constitute a linear motor 41. The X guide bar 39 moves in the Y direction because the mover 40a is driven by electromagnetic interaction with the stator 40b and the mover 41a is driven by electromagnetic interaction with the stator 41b. Then, by adjusting the driving amount of the linear motor 40 and the linear motor 41, the wafer stage 36 rotates around the Z axis orthogonal to the X axis and the Y axis. That is, the wafer stages 36 (and the sample stage 38) are driven about the Y direction and around the Z axis almost integrally with the X guide bar 39 by the linear motors 40 and 41.
[0059]
A mover of the X trim motor 43 is mounted on the X guide bar 39 in the X direction. The X trim motor 43 adjusts the position of the X guide bar 39 in the X direction by generating a thrust in the X direction, and its stator is provided on a reaction frame (not shown). Therefore, the reaction force when driving the wafer stage 36 in the X direction is transmitted to the base plate via the reaction frame.
[0060]
The sample table 38 is supported on the X guide bar 39 in a non-contact manner so as to be relatively movable in the X direction via a magnetic guide including a magnet and an actuator that maintains a predetermined gap in the Z direction between the sample table 38 and the X guide bar 39.・ Holded. The wafer stage 36 is driven in the X direction by electromagnetic interaction of a linear motor 42 having a stator embedded in the X guide bar 39. Although not shown, the mover of the linear motor 42 is attached to the wafer stage 36. A wafer W is fixed on the upper surface of the sample table 38 via a wafer holder (not shown) by vacuum suction or the like.
[0061]
Note that the linear motor 42 is disposed closer to the wafer W mounted on the wafer stage 36 than the linear motors 40 and 41, and the movable element of the linear motor 42 is fixed to the sample table 38. I have. For this reason, it is desirable that the linear motor 42 be a moving magnet type linear motor in which a coil serving as a heat source becomes a stator and moves away from the wafer W and is not directly fixed to the sample table 38.
[0062]
The linear motors 40 and 41 require a much larger thrust than the X linear motor 42 because the linear motor 42, the X guide bar 39, and the sample stage 38 are integrally driven. Therefore, a large amount of power is required and the amount of heat generated is larger than that of the linear motor 42. Therefore, it is desirable to use a moving coil type linear motor for the linear motors 40 and 41. However, since the moving coil type linear motor needs to circulate the refrigerant through the movers 40a and 41a, if there is a problem in the device configuration, a moving magnet type linear motor in which a magnet is provided on the movers 40a and 41a side. A motor may be used.
[0063]
A movable mirror 44 extending in the X direction and a movable mirror 45 extending in the Y direction are attached to the end of the wafer stage 36. Laser interferometers 46 and 47 (see FIG. 1) are mounted at positions facing the mirror surfaces of these movable mirrors 44 and 45, respectively. The positions of the wafer stage 36 in the X direction and the Y direction are determined to have a predetermined resolution. For example, it is measured in real time with a resolution of about 0.5 to 1 nm. At least one of the laser interferometers 46 and 47 is a multi-axis interferometer having two or more measurement axes, and based on the measurement values of these laser interferometers, the wafer stage 36 (and thus the wafer W) in the X direction is measured. Not only the position and the position in the Y direction, but also the rotation amount and the leveling amount around the Z axis can be obtained.
[0064]
In the stage device having the above configuration, the coil array 14 provided on one of the stator 11 and the mover 12 of the linear motors 40 to 42 is manufactured by using the above-described method of adjusting the positional relationship of the coil 13 and the like. If the magnet arrays 24 and 25 provided on the other side are formed only of the magnets 24 and 25 having the same maximum value of the magnetic field as described above, the control controller 32 performs the normal control. I do. In other words, a current having a phase difference of 120 ° between the phases of the coils 13 of each phase forming the coil array 14 provided in each of the linear motors 40 to 42 and having a constant magnitude of current is preset. Supply according to the given sequence.
[0065]
On the other hand, there is a position error or the like in the coil 13 constituting the coil array 14 provided on one of the stator 11 and the movable element 12 of the linear motors 40 to 42, and the magnets 18 forming the magnet arrays 24 and 25 have If the maximum value of the magnitude of the magnetic field formed by each of the coils 20 is not the same, the above-described current control for controlling the phase of the current supplied to the coil 13 of each phase or the current control for controlling the magnitude of the current is performed. While performing, the drive of each of the linear motors 40 to 42 is controlled.
[0066]
(Exposure equipment)
Next, the exposure apparatus will be described in detail. FIG. 8 is a diagram showing a schematic configuration of the exposure apparatus. The exposure apparatus shown in FIG. 8 transfers a pattern formed on reticle R to wafer W while relatively moving reticle R as a mask and wafer W as a photosensitive substrate with respect to projection optical system PL. An example in which the present invention is applied to a step-and-scan type exposure apparatus for manufacturing a semiconductor device will be described.
[0067]
In the following description, the XYZ rectangular coordinate system shown in FIG. 8 is set, and the positional relationship of each member will be described with reference to the XYZ rectangular coordinate system. The XYZ orthogonal coordinate system is set such that the X axis and the Y axis are parallel to the wafer W, and the Z axis is set in a direction orthogonal to the wafer W. In the XYZ coordinate system in the figure, the XY plane is actually set to a plane parallel to the horizontal plane, and the Z axis is set vertically upward. In the present embodiment, the direction in which the reticle R and the wafer W are moved (scanning direction SD) is set to the Y direction.
[0068]
In FIG. 8, an ArF excimer laser light source (wavelength: 193 nm) that emits exposure light IL that is a parallel light beam having a substantially rectangular cross section is used as the exposure light source 81. Exposure light IL (exposure beam) composed of an ultraviolet pulse having a wavelength of 193 nm from the exposure light source 81 passes through a beam matching unit (BMU) 82 and enters a variable dimmer 83 as an optical attenuator. The exposure light IL that has passed through the variable dimmer 83 enters a first fly-eye lens 86 as a first-stage optical integrator (uniformizer or homogenizer) via a beam forming system 85 including lens systems 84a and 84b. I do. The exposure light IL emitted from the first fly-eye lens 86 passes through a first lens system 87a, a mirror 88 for bending the optical path, and a second lens system 87b as a second stage optical integrator. The light enters the eye lens 89.
[0069]
An aperture stop plate 90 is rotatably arranged by a drive motor 90e on the exit surface of the second fly-eye lens 89, that is, on the optical Fourier transform surface (pupil surface of the illumination system) with respect to the pattern surface of the reticle R to be exposed. ing. The aperture stop plate 90 has a circular aperture stop 90a for normal illumination, an aperture stop 90b for annular illumination, and an aperture stop (not shown) for deformed illumination comprising a plurality (for example, four poles) of eccentric small apertures. And a small circular aperture stop (not shown) for a small coherence factor (σ value) are arranged so as to be switchable. The main control system 103 that controls the overall operation of the exposure apparatus rotates the aperture stop plate 90 via the drive motor 90e to set the illumination conditions.
[0070]
In order to obtain a high illuminance (pulse energy) by increasing the utilization efficiency of the exposure light IL when performing deformed illumination (such as annular illumination or quadrupole illumination), the exposure light IL is transmitted to the second fly-eye lens 89. At the stage of incidence, it is desirable that the cross-sectional shape of the exposure light IL be shaped into a substantially annular shape. For this purpose, the first fly-eye lens 86 may be replaced with, for example, a diffractive optical element (DOE) composed of an aggregate of a large number of phase-type diffraction gratings. Further, the illumination condition switching system is not limited to the above configuration, and a conical prism (axicon) and / or zoom optical system and a diffractive optical element may be used in combination with the aperture stop plate 90 or alone. good. When an internal reflection type integrator (such as a rod integrator) is used as the second-stage optical integrator, the exposure light IL is applied to the optical axis IAX of the illumination system using, for example, a DOE, a conical prism, or a polyhedral prism. It is desirable that the light be incident on the internal reflection type integrator while being inclined, and that the range of the incident angle of the exposure light IL on the incident surface be changed according to the illumination conditions.
[0071]
8, the exposure light IL emitted from the second fly-eye lens 89 and having passed through the aperture stop 90a for normal illumination sequentially passes through lens systems 91 and 92 along the optical axis IAX, and passes through a fixed blind (fixed illumination field of view). Stop) 93a and a movable blind (movable illumination field stop) 93b. As disclosed in, for example, JP-A-4-196513 and corresponding U.S. Pat. No. 5,473,410, the fixed blind 93a has a scanning exposure direction at a center in a circular visual field of a projection optical system PL described later. It has an opening arranged so as to extend in a direction orthogonal to the shape of a straight slit or a rectangle (hereinafter collectively referred to as a “slit shape”).
[0072]
The movable blind 93b is used to change the width of the illumination visual field area in the scanning direction in order to prevent unnecessary exposure at the start and end of scanning exposure on each shot area on the wafer W. It is also used to change the size of the pattern area of the reticle R in a direction (non-scanning direction) orthogonal to the scanning direction. The fixed blind 93a and the movable blind 93b are provided on a conjugate plane with respect to a surface on which the pattern of the reticle R is formed (hereinafter, referred to as a reticle surface).
[0073]
Exposure light IL that has passed through the fixed blind 93a and the movable blind 93b during exposure passes through a mirror 94 for bending the optical path, a lens system 95 for imaging, a condenser lens 96, and a main condenser lens system 97, and a reticle as a mask. The illumination area (illumination field area) IR on the R pattern surface (lower surface) is illuminated.
[0074]
Under the exposure light IL, an image of the circuit pattern in the illumination area IR of the reticle R is projected at a predetermined projection magnification β (β is, for example, 1/4 or 1/5) via the bi-telecentric projection optical system PL. Is transferred to a slit-shaped exposure area IW of a photoresist layer on a wafer W as a substrate disposed on the image plane of the projection optical system PL. The projection optical system PL of the present embodiment is a dioptric system (refractive system), but it goes without saying that a catadioptric system (reflective system) or a reflective system can also be used.
[0075]
The reticle R is held by suction on a reticle stage 98 as a mask stage. The reticle stage 98 can move at a constant speed in the Y direction on the reticle base 99 and can tilt in the X, Y, and rotation directions. It is placed on. A moving mirror 100 is attached to one end of the reticle stage 98, and a laser interferometer 101 is provided to face the mirror surface of the moving mirror 100. The two-dimensional position and rotation angle of the reticle stage 98 (reticle R) are measured in real time by the laser interferometer 101. The drive control unit 102 controls the scanning speed and position of the reticle stage 98 based on the measurement result of the laser interferometer 101 and the control information from the main control system 103.
[0076]
On the other hand, the wafer W is held by suction on a wafer stage 105 as a substrate stage via a wafer holder 104, and the wafer stage 105 is placed on a wafer base 106 along an XY plane parallel to the image plane of the projection optical system PL. Dimensionally move. That is, the wafer stage 105 moves at a constant speed in the Y direction on the wafer base 106, and moves stepwise in the X direction and the Y direction. Further, the wafer stage 105 also incorporates a Z leveling mechanism for controlling the position (focus position) of the wafer W in the Z direction and the tilt angles around the X axis and the Y axis.
[0077]
Although not shown, a projection optical system for projecting a slit image obliquely to a plurality of measurement points on the surface (wafer surface) of the wafer W on the side surface of the projection optical system PL, and reflection from the wafer surface There is also provided a multipoint autofocus sensor comprising a light receiving optical system for receiving light and generating a focus signal corresponding to the focus positions of the plurality of measurement points, and these focus signals are mainly used. It is supplied to a focus control unit in the control system 103. At the time of scanning exposure, the focus control unit in the main control system 103 continuously drives the Z-leveling mechanism in the wafer stage 105 by an auto-focus method based on the information of the focus signals (focus positions). Thereby, the surface of the wafer W is focused on the image plane of the projection optical system PL.
[0078]
A moving mirror 107 is attached to one end of the wafer stage 105, and a laser interferometer 108 is provided to face the mirror surface of the moving mirror 107. The laser interferometer 108 measures the position of the wafer stage 105 in the X and Y directions and the rotation angles around the X, Y, and Z axes in real time. The drive control unit 109 controls the scanning speed and the position of the wafer stage 105 based on the measurement result of the laser interferometer 108 and the control information from the main control system 103. Note that the wafer stage 105 in FIG. 8 corresponds to the stage device 35 shown in FIGS. 6 and 7, and the control controller 32 and the position detection units 34a and 34b shown in FIG. , And current amplifiers 33a to 33c are provided. The moving mirror 107 corresponds to the moving mirrors 44 and 45 shown in FIG. 7, and the laser interferometer 108 corresponds to the laser interferometers 46 and 47 shown in FIG.
[0079]
The main control system 103 sends various information such as the moving position, moving speed, moving acceleration, and position offset of the reticle stage 98 and the wafer stage 105 to the drive control units 102 and 109. Accordingly, the reticle R is scanned via the reticle stage 98 via the wafer stage 105 in synchronization with the scanning of the reticle R in the + Y direction (or -Y direction) with respect to the illumination region IR of the exposure light IL at the speed Vr. The wafer W is scanned with respect to the exposure area IW of the pattern image of the reticle R in the −Y direction (or + Y direction) at a speed β · Vr (β is a projection magnification from the reticle R to the wafer W). At this time, at the start and end of the scanning exposure, the opening and closing operation of the movable blind 93b is controlled in order to prevent unnecessary portions from being exposed. The movement directions of the reticle R and the wafer W are opposite because the projection optical system PL of the present embodiment performs reverse projection.
[0080]
Next, the operation at the time of exposure of the exposure apparatus having the above-described configuration will be briefly described. When the exposure operation is started, a control signal is output from main control system 103 to drive control units 102 and 109, and drive control units 102 and 109 increase the acceleration of reticle stage 98 and wafer stage 105. The drive control unit 109 accelerates the wafer stage 105 based on a control signal (target position signal) output from the main control system 103 and a detection signal output from the laser interferometer 108, and sets a shot to be exposed on the wafer W. The area is moved to the exposure start position. At this time, the above-described reaction force processing is performed in accordance with the movement of the reticle stage 98 or the wafer stage 105. Note that the reticle stage 98 is also accelerated in the same manner as the wafer stage 105.
[0081]
When the speed of each of the wafer stage 105 and the reticle stage 98 becomes constant after the acceleration period ends, the wafer stage 105 is moved in the −Y direction at a speed Vw (= β) while irradiating the reticle R with slit-shaped illumination light. (Vm), the pattern formed on the reticle is transferred to the shot area set on the wafer W via the projection optical system PL while the reticle stage unit scans and moves at a speed Vm in the + Y direction while scanning and moving at a speed Vm. I do. When the transfer of the reticle pattern to one shot area is completed, the wafer stage 105 and the reticle stage 98 are decelerated to stop the irradiation of the reticle R with the illumination light.
[0082]
Next, the main control system 103 drives the wafer stage 105 to set a shot area to which a pattern is to be transferred next in the vicinity of the projection area of the projection optical system PL (an area where the pattern of the reticle R is projected) (exposure start position). ). Also at this time, a reaction force process for canceling the reaction force generated according to the movement of the wafer stage 105 is performed. Then, similarly to the above-described operation, after the wafer stage 105 and the reticle stage 98 are accelerated to have a constant speed, the reticle R is irradiated with illumination light to sequentially transfer the reticle pattern to the shot area. FIG. 9 is a diagram illustrating an example of the movement path of the wafer W with respect to the projection area during pattern transfer. As shown in this figure, when transferring the pattern of the reticle R to the shot area SA, the wafer W is moved at a constant speed along the Y direction (+ Y direction or -Y direction). On the other hand, when the exposure processing for one shot area is completed and the process moves to the exposure start position of the next shot area to be exposed, the step movement is performed in the X direction (or Y direction) while accelerating and decelerating. By repeating such an operation, exposure processing is performed on all shot areas set on the wafer W.
[0083]
Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and can be freely changed within the scope of the present invention. For example, in the above embodiment, the case where the exposure light source 81 is an ArF excimer laser light source has been described as an example. However, as the exposure light source 81, for example, g-line (wavelength 436 nm) and i-line (wavelength 365 nm) are used. Ultra-high pressure mercury lamp, KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), F ₂ Excimer laser (wavelength 157 nm), Kr ₂ A laser (wavelength: 146 nm), a high frequency generator of a YAG laser, or a high frequency generator of a semiconductor laser can be used.
[0084]
Further, a single-wavelength laser beam in the infrared or visible range oscillated from a DFB semiconductor laser or a fiber laser as a light source is amplified by, for example, a fiber amplifier doped with erbium (or both erbium and ytterbium), and nonlinearly amplified. It is also possible to use a harmonic whose wavelength has been converted to ultraviolet light using a crystal. For example, when the oscillation wavelength of the single wavelength laser is in the range of 1.51 to 1.59 μm, the 8th harmonic whose generation wavelength is in the range of 189 to 199 nm, or in the range of 151 to 159 nm, A certain tenth harmonic is output.
[0085]
In particular, when the oscillation wavelength is in the range of 1.544 to 1.553 μm, an 8th harmonic whose generation wavelength is in the range of 193 to 194 nm, that is, ultraviolet light having substantially the same wavelength as the ArF excimer laser light is obtained, Assuming that the oscillation wavelength is in the range of 1.57 to 1.58 μm, the tenth harmonic in which the generated wavelength is in the range of 157 to 158 nm, ie, F ₂ Ultraviolet light having substantially the same wavelength as the laser light is obtained. When the oscillation wavelength is in the range of 1.03 to 1.12 μm, a seventh harmonic having a generation wavelength in the range of 147 to 160 nm is output. In particular, the oscillation wavelength is in the range of 1.099 to 1.106 μm. , The seventh harmonic having a generation wavelength in the range of 157 to 158 μm, that is, F ₂ Ultraviolet light having substantially the same wavelength as the laser light is obtained. In this case, for example, an ytterbium-doped fiber laser can be used as the single-wavelength oscillation laser.
[0086]
The present invention is not limited to an exposure apparatus used for manufacturing a semiconductor element, but also an exposure apparatus used for manufacturing a display including a liquid crystal display element (LCD) and the like, which transfers a device pattern onto a glass plate, and a thin film magnetic head. The present invention can also be applied to an exposure apparatus used for manufacturing to transfer a device pattern onto a ceramic wafer, an exposure apparatus used for manufacturing an imaging device such as a CCD, and the like. Furthermore, in order to manufacture a reticle or a mask used in an optical exposure apparatus, an EUV exposure apparatus, an X-ray exposure apparatus, an electron beam exposure apparatus, etc., an exposure apparatus for transferring a circuit pattern onto a glass substrate or a silicon wafer. The present invention can also be applied. Here, in an exposure apparatus using DUV (far ultraviolet) light, VUV (vacuum ultraviolet) light, or the like, a transmission type reticle is generally used, and as a reticle substrate, quartz glass, fluorine-doped quartz glass, fluorite, Magnesium fluoride, quartz, or the like is used. In a proximity type X-ray exposure apparatus, an electron beam exposure apparatus, or the like, a transmission mask (stencil mask, membrane mask) is used, and a silicon wafer or the like is used as a mask substrate.
[0087]
Further, the stage control device of the present invention may be used not only for controlling the movement operation of the wafer stage provided in the exposure apparatus, but also for controlling the movement operation of the reticle stage. Further, the present invention can be generally applied to the case of controlling not only an exposure apparatus but also a stage apparatus that moves an object in a mounted state (not limited to one-dimensional movement or two-dimensional movement). is there.
[0088]
Next, an embodiment of a microdevice manufacturing method using an exposure apparatus and an exposure method in a lithography process according to an embodiment of the present invention will be described. FIG. 10 is a diagram showing a flowchart of a manufacturing example of a micro device (a semiconductor chip such as an IC or LSI, a liquid crystal panel, a CCD, a thin-film magnetic head, a micromachine, etc.). As shown in FIG. 10, first, in step S10 (design step), a function / performance design (for example, a circuit design of a semiconductor device) of a micro device is performed, and a pattern design for realizing the function is performed. Subsequently, in step S11 (mask manufacturing step), a mask (reticle) on which the designed circuit pattern is formed is manufactured. On the other hand, in step S12 (wafer manufacturing step), a wafer is manufactured using a material such as silicon.
[0089]
Next, in step S13 (wafer processing step), using the mask and the wafer prepared in steps S10 to S12, an actual circuit or the like is formed on the wafer by a lithography technique or the like, as described later. Next, in step S14 (device assembling step), device assembly is performed using the wafer processed in step S13. Step S14 includes, as necessary, processes such as a dicing process, a bonding process, and a packaging process (chip encapsulation). Finally, in step S15 (inspection step), inspections such as an operation confirmation test and a durability test of the microdevice manufactured in step S14 are performed. After these steps, the microdevice is completed and shipped.
[0090]
FIG. 11 is a diagram showing an example of a detailed flow of step S13 in FIG. 10 in the case of a semiconductor device. In FIG. 11, in step S21 (oxidation step), the surface of the wafer is oxidized. In step S22 (CVD step), an insulating film is formed on the wafer surface. In step S23 (electrode forming step), electrodes are formed on the wafer by vapor deposition. In step S24 (ion implantation step), ions are implanted into the wafer. Each of the above-described steps S21 to S24 constitutes a pre-processing step in each stage of wafer processing, and is selected and executed according to a necessary process in each stage.
[0091]
In each stage of the wafer process, when the above-mentioned pre-processing step is completed, the post-processing step is executed as follows. In this post-processing step, first, in step 25 (resist forming step), a photosensitive agent is applied to the wafer. Subsequently, in step 26 (exposure step), the circuit pattern of the mask is transferred to the wafer by the lithography system (exposure apparatus) and the exposure method described above. Next, in step 27 (development step), the exposed wafer is developed, and in step 28 (etching step), the exposed members other than the portion where the resist remains are removed by etching. Then, in step 29 (resist removing step), unnecessary resist after etching is removed. By repeatedly performing these pre-processing steps and post-processing steps, multiple circuit patterns are formed on the wafer.
[0092]
【The invention's effect】
As described above, according to the present invention, each of the first dimension from the center position to the center position of one pole portion and the second dimension from the center position to the center position of another pole portion are substantially the same. A plurality of coils are arranged so that the positional relationship between one pole portion and the other pole portion with respect to the center position of the coil is the same, thereby forming a coil row. They are arranged so that the shifts are the same. Although thrust ripples are caused by misalignment between coils, in the present invention, even when each coil is manufactured out of design value, all coils forming a coil row are similarly misaligned. Since there is almost no displacement between the coils, it is possible to effectively suppress the generation of thrust ripple. As a result, there is an effect that positioning accuracy and control performance can be improved.
Further, according to the present invention, since the number of coils equal to the number of phases of the supplied alternating current is set as one set, and the first dimension and the second dimension are substantially the same for each coil set, As a result, the positional deviations of the individual coils are canceled out, and the positional deviations between the phases become substantially the same, so that the generation of thrust ripples can be effectively suppressed, and the first dimension and the second dimension of all the coils forming the coil array are formed. There is an effect that it is not necessary to prepare coils having substantially the same dimensions, and it is easy to manufacture the linear motor device.
Further, according to the present invention, a current in which the phase of at least one phase is changed is supplied to the coil in accordance with the positional shift of the center position of the pole portion with respect to the center of each coil forming the coil array, Even if each coil is arranged in a state where there is a displacement between the coils, the generation of thrust ripple can be effectively suppressed, and as a result, the positioning accuracy and control performance can be improved. There is.
Further, according to the present invention, even when the magnetic flux density distribution formed by the magnet rows varies due to factors such as manufacturing errors of the magnets, at least one of a plurality of phases of the alternating current supplied to the coil rows. Since the phase amplitude is changed according to the magnetic flux density distribution of the magnetic field formed by the magnet array, thrust ripples can be reduced to a practically negligible level, and as a result, positioning accuracy and control performance can be improved. This has the effect.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an external configuration of a linear motor device according to an embodiment of the present invention.
FIG. 2 is a top perspective view of the linear motor device shown in FIG.
FIG. 3 is a cross-sectional view taken along a line AA in FIGS. 1 and 2;
FIG. 4 is a top view showing one coil 13 constituting a coil row 14 provided in the linear motor device according to one embodiment of the present invention.
FIG. 5 is a diagram for explaining a thrust variation caused by a magnetic field formed by a magnet and a displacement of a coil.
FIG. 6 is a diagram showing a stage device including a linear motor device according to an embodiment of the present invention and a control device thereof.
FIG. 7 is a perspective view showing a configuration example of a stage device 35.
FIG. 8 is a diagram showing a schematic configuration of an exposure apparatus.
FIG. 9 is a diagram illustrating an example of a movement path of a wafer W with respect to a projection area during pattern transfer.
FIG. 10 is a flowchart illustrating an example of a micro device manufacturing process.
FIG. 11 is a diagram showing an example of a detailed flow of step S13 in FIG. 10 in the case of a semiconductor device.
[Explanation of symbols]
10 Linear motor device
13 coils
13a Long part (one pole part, pole part)
13b Long part (other pole part, pole part)
14 coil row
32 control controller (current supply unit)
36 Wafer stage (stage part)
98 Reticle stage (mask stage)
105 Wafer stage (substrate stage)
C Coil center (Coil center position)
C1 First pole center (center position of one pole part)
C2 2nd pole center (center position of other pole parts)
L1 dimension (first dimension)
L2 dimension (second dimension)
R reticle (mask)
W wafer (photosensitive substrate)

Claims (11)

In a linear motor device having a coil array in which a plurality of coils are arranged,
Each of the plurality of coils has a first dimension from a center position of the coil to a center position of one pole portion contributing to thrust generation, and a first dimension from the center position to a center position of another pole portion contributing to thrust generation. Each of the second dimensions is substantially the same,
A linear motor, wherein the coil array is configured by arranging the plurality of coils so that a positional relationship between the one pole portion and the other pole portion with respect to a center position of the coil is the same. apparatus. An alternating current having a plurality of phases is supplied to the coil array,
The coil array is characterized in that each of the first dimension and the second dimension is substantially the same for each coil group in which the number of the coils equal to the number of phases of the alternating current is a set. The linear motor device according to claim 1. In a linear motor device that generates thrust in a predetermined direction,
A coil row in which coils having pole portions that contribute to the generation of the thrust are arranged in the thrust direction,
A current supply unit that supplies an alternating current having a plurality of phases to the coil array and changes a phase of at least one of the plurality of phases according to a positional shift of a center position of the pole portion with respect to a center of the coil. A linear motor device comprising: 4. The linear motor device according to claim 3, wherein the current supply unit changes the phase of the alternating current supplied to the coil whose position of the pole part is shifted. 5. The linear motor device according to any one of claims 1 to 4, wherein the center position of the pole portion is a center position of a length of the pole portion along the thrust direction. A coil array having a plurality of coils arranged in a predetermined direction, and a magnet example in which a plurality of magnets are arranged in the predetermined direction so that the polarities alternately change,
A current supply unit that supplies an alternating current having a plurality of phases to the coil array and changes an amplitude of at least one of the plurality of phases according to a magnetic flux density distribution of a magnetic field formed by the magnet array. A linear motor device characterized by the above-mentioned. In a linear motor manufacturing method for manufacturing a linear motor by arranging a plurality of coils having pole portions that contribute to thrust generation,
A method of manufacturing a linear motor, comprising the step of classifying the coils for each coil having the same position of the pole portion with respect to the center of the coil. 8. The method according to claim 7, further comprising the step of arranging coils belonging to the same classification along a relative movement direction. Combining the classified coils by the same number as the number of phases of the alternating current supplied to the linear motor to form a coil group for each classification;
Arranging the coil set along a direction of relative movement. A stage device, wherein the stage unit is driven by the linear motor device according to any one of claims 1 to 6. An exposure apparatus for transferring a pattern formed on a mask to a photosensitive substrate,
A mask stage for mounting the mask,
And a substrate stage on which the photosensitive substrate is mounted,
An exposure apparatus comprising the stage device according to claim 10 as at least one of the mask stage and the substrate stage.

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