JP4276404B2

JP4276404B2 - Electrostatic chuck electrode structure

Info

Publication number: JP4276404B2
Application number: JP2002082946A
Authority: JP
Inventors: 良昭辰己; 欣也宮下
Original assignee: 株式会社クリエイティブテクノロジー
Priority date: 2002-03-25
Filing date: 2002-03-25
Publication date: 2009-06-10
Anticipated expiration: 2022-03-25
Also published as: JP2003282687A

Description

【０００１】
【発明の属する技術分野】
この発明は、金属基盤の上面側に静電チャックシートを積層して形成された静電チャックの電極構造に係り、特に、単に静電チャックシートに確実に給電できるだけでなく、使用済み静電チャックから金属基盤のみを分離して取り出し、容易に再利用することができるようにした静電チャックの電極構造に関する。
【０００２】
【従来の技術】
半導体製造プロセスにおいては、近年、そのドライ化が急速に進み、プラズマエッチング装置、プラズマＣＶＤ装置、イオン注入装置、アッシング装置、電子ビームリソグラフィー装置、Ｘ線リソグラフィー装置等の装置が頻繁に使用されており、また、これらの装置においては、半導体ウエハ等の試料を真空中で処理することがしばしば行われている。
【０００３】
また、このような装置において、試料を保持するための手段としては、機械的方法によるメカニカルチャック、大気圧との圧力差を利用する真空チャック、静電吸着力を発揮する静電チャックシートを利用した静電チャック等の方法が提案されているが、真空中で試料とホルダーとを熱的に均一に、しかも、信頼性高く保持する上で、静電チャックが有利であるとされている。
【０００４】
この静電チャックは、一般に、表面をアルマイト処理したアルミニウム等の金属で形成された金属基盤とこの金属基盤の上面にポリイミド層等の第一絶縁層、銅箔層等の電極層、及びポリイミド層等の第二絶縁層を順次積層して形成された静電チャックシートとで構成されており、この静電チャックシートの電極層に直流高電圧（高電力）を印加して静電力を発現せしめるものであり、また、この静電チャックシートの電極層に電力を供給するための電極構造は、通常、金属基盤の上下面間を貫通する貫通孔と、この貫通孔内に配設され、金属基盤の下面側から供給された電力を上面側に積層された静電チャックシートに供給する給電端子と、電気絶縁性材料で形成されて上記貫通孔の内壁と給電端子との間を絶縁すると共に上記給電端子を保持する絶縁保持部材とで構成されている。
【０００５】
そして、このような静電チャックの電極構造としては、例えば、接着剤を介して金属基盤の貫通孔内面に接着されると共にその内部に導電層を内在し、そして、貫通孔が基盤表面に至る個所で静電チャックシートと電気的に接合される給電シートを備えたもの（特許第2,581,627号掲載公報）や、サセプタ（金属基盤）の厚さ方向に貫通する給電孔と、この給電孔の内壁との間で絶縁部材を介して設けられた給電補助ピンとを備え、上記絶縁部材がエポキシ系接着剤、接着剤により給電孔内に接着固定されるエンジニアリングプラスチック、若しくは接着剤やロウ付けにより給電孔内に固着されるセラミックスで形成されたもの（特開平7-74,234号公報）や、サセプタ（金属基盤）の厚さ方向に貫通する給電スリットを形成し、この給電スリット内に給電シートを挿通させると共にサセプタの静電チャックシート載置面とその反対側面との間の連通を遮断する閉塞部材を充填したもの（特開平7-86,381号公報）等が提案されている。
【０００６】
しかしながら、これら従来の静電チャックの電極構造は、そのいずれも、サセプタ（金属基盤）の静電チャックシート載置面とその反対側面との間を連通する貫通孔（給電孔又は給電スリット）内において、給電端子（給電シートや給電補助ピン）を接着剤等の手段で固着した構造を有するものであり、貫通孔内で給電端子がずれたり移動したりすることがなくて静電チャックシートに確実に給電できるという利点はあるものの、使用済み静電チャックの金属基盤を再利用する際に、この金属基盤から給電端子やこれら金属基盤と給電端子との間の絶縁部材を分離して除去する作業が極めて困難であり、実質的に金属基盤の再利用が不可能になる場合が多々生じるという問題があった。
【０００７】
【発明が解決しようとする課題】
そこで、本発明者らは、このような従来の静電チャックの電極構造における問題点を解決し、静電チャックにおける電極構造の組立・分解を容易に行うことができ、これによって使用済み静電チャックにおける金属基盤の再利用を容易に行うことができる静電チャックの電極構造について鋭意検討し、本発明を完成させた。
【０００８】
従って、本発明の目的は、金属基盤の上面側に静電チャックシートを積層して形成された静電チャックにおいて、静電チャックシートに給電するための電極構造を容易に組立てることができ、また、分解して金属基盤から電極構造を取り外すことができる静電チャックの電極構造を提供することにある。
【０００９】
【課題を解決するための手段】
すなわち、本発明は、金属基盤の上面側に静電チャックシートを積層して形成された静電チャックにおいて、上記金属基盤の上下面間を貫通する貫通孔と、この貫通孔内に配設され、金属基盤の下面側から供給された電力を上面側に積層された静電チャックシートに供給する給電端子と、電気絶縁性材料で形成されて上記貫通孔の内壁と給電端子との間を絶縁すると共に上記給電端子を保持する絶縁保持部材とで構成された静電チャックの電極構造であり、上記絶縁保持部材を貫通孔の内壁に着脱可能に取り付けた、静電チャックの電極構造である。
【００１０】
本発明において、金属基盤の上下面間を貫通する貫通孔の内壁に絶縁保持部材を着脱可能に取り付けるための具体的な手段については、特に制限されるものではないが、好ましくは、下記の構成例を例示することができる。
【００１１】
すなわち、第一の構成例としては、上記金属基盤を貫通する貫通孔には、その内壁略中間位置に、内方に向けて突出してこの貫通孔内を金属基盤の下面側に位置する受電側収容部と金属基盤の上面側に位置する給電側収容部とに区画するフランジ部が設けられており、また、給電端子は、上記受電側収容部内に配設されて外部電源に接続される受電部と、上記給電側収容部内に配設されて静電チャックシートに電力を供給する給電部と、これら受電部と給電部との間を電気的に接続する連結部とで構成されており、更に、絶縁保持部材は、上記給電端子の受電部を収容する下向開口凹部を有すると共にこの下向開口凹部に連通する連通孔を有し、上記貫通孔の受電側収容部内に収容される受電部保持体と、上記給電部を収容する上向開口凹部を有すると共にこの上向開口凹部に連通する連通孔を有し、上記貫通孔の給電側収容部内に収容される給電部保持体と、これら受電部保持体と給電部保持体との間を気密にシールするシール部材とで構成されており、上記受電部保持体及び給電部保持体の各連通孔内を貫通して上記給電端子を構成する受電部と給電部との間を連結する連結部により上記貫通孔内に給電端子と絶縁保持部材とを固定するようにした電極構造を挙げることができる。
【００１２】
ここで、金属基盤の上下面間を貫通する貫通孔の横断面形状については、例えば円形、三角形、四角形、五角形以上の多角形等どのような形状であってもよいが、加工性の観点から好ましくは円形又は正四角形（正方形）であるのがよい。また、この貫通孔の内壁略中間位置に形成されてこの貫通孔内を受電側収容部と給電側収容部とに区画するフランジ部については、その全周に亘って突出寸法及び厚さ寸法を同じ大きさに形成するのがよい。
【００１３】
また、上記受電部、給電部及び連結部で構成される給電端子は、その受電部又は給電部若しくはこれら受電部及び給電部には雌ねじ部が形成され、また、これら受電部と給電部との間を接続する連結部には上記受電部及び／又は給電部の雌ねじ部に螺合する雄ねじ部が形成され、組立時にはこの連結部の雄ねじ部を上記受電部及び／又は給電部の雌ねじ部に螺合して締結せしめ、また、分解時にはこの連結部の雄ねじ部と上記受電部及び／又は給電部の雌ねじ部との間の螺子結合を解いて分離できるようになっている。
【００１４】
ここで、上記受電部、給電部及び連結部については、上記受電部保持体及び給電部保持体の各連通孔内に連結部を貫通せしめ、この連結部の雄ねじ部を上記受電部及び／又は給電部の雌ねじ部に螺合させることができればよく、例えば、受電部と連結部の基部とを一体に連結すると共に連結部の先端部には雄ねじ部を設けて頭付きボルト状に形成し、給電部には雌ねじ部を設けて袋ナット状に形成し、受電部及び連結部側か若しくは給電部側の何れかを回転させて連結部の雄ねじ部を給電部の雌ねじ部に螺合させるようにしてもよく、反対に、給電部と連結部の基部とを一体に連結すると共に連結部の先端部には雄ねじ部を設けて頭付きボルト状に形成し、受電部には雌ねじ部を設けて袋ナット状に形成し、給電部及び連結部側か若しくは受電部側の何れかを回転させて連結部の雄ねじ部を受電部の雌ねじ部に螺合させるようにしてもよく、また、受電部と給電部には互いに逆方向に切られた雌ねじ部を設けて袋ナット状に形成し、また、連結部の両端部には互いに逆方向に切られた雄ねじ部を設け、受電部及び／又は給電部を回転させてこれら受電部及び給電部と連結部との間を螺合させるようにしてもよい。
【００１５】
更に、上記絶縁保持部材を構成する受電部保持体及び給電部保持体は、電気絶縁性を有する合成樹脂、セラミックス等の材質で形成され、また、好ましくは、その何れか一方又は双方に貫通孔のフランジ部が形成する空間部内に嵌合して互いに接近した位置で相対向する対向面を有する突出部を形成し、この突出部の対向面を利用してこれら受電部保持体と給電部保持体との間を気密にシールするシール部材を設けるのがよい。
【００１６】
また、上記絶縁保持部材を構成するシール部材については、電気絶縁性を有すると共に所定の弾性を有する合成樹脂、ゴム等の材質で形成され、給電端子を構成する受電部と給電部との間を連結部で連結した際に上記受電部保持体と給電部保持体との間に加圧下に挟み込まれてこれら受電部保持体と給電部保持体との間を気密にシールするものであればよく、例えばＯ-リング、平パッキン等を例示することができる。
【００１７】
この第一の構成例において、金属基盤の上下面間に差圧が生じるのを防止する必要がある場合には、好ましくは、外部電源と接続した給電ピン等を有し、この金属基盤を載置する支持台側と上記絶縁保持部材の受電部保持体との間及び上記絶縁保持部材の受電部保持体又は給電部保持体と上記給電端子を構成する受電部又は給電部との間にそれぞれ電気絶縁性及び弾性を有するＯ-リング等のシール部材を介装するのがよい。
また、絶縁保持部材を構成する受電部保持体及び給電部保持体と給電端子を構成する受電部及び給電部とは、これら受電部保持体と受電部及び／又は給電部保持体と給電部がそれぞれ別体に形成されていてもよいが、受電部保持体及び／又は給電部保持体を貫通孔の受電側収容部内及び／又は給電側収容部内に回転可能に配設することにより、受電部保持体と受電部及び／又は給電部保持体と給電部は受電部保持体及び／又は給電部保持体の成形時にインサート成形等の手段で受電部及び／又は給電部と一体に形成してもよい。
【００１８】
このような第一の構成例に係る静電チャックの電極構造によれば、その組立時には、貫通孔内に絶縁保持部材を構成する受電部保持体、給電部保持体及びシール部材、及び給電端子を構成する受電部、給電部及び連結部をそれぞれ組み込み、上記連結部の雄ねじ部を受電部及び／又は給電部の雌ねじ部に螺合して締結せしめればよく、また、その分解時には上記連結部の雄ねじ部と受電部及び／又は給電部の雌ねじ部との間の螺子結合を解除し、貫通孔内から受電部、給電部及び連結部と、受電部保持体、給電部保持体及びシール部材とを取り外せばよい。
【００１９】
また、第二の構成例としては、金属基盤を貫通する貫通孔は、横断面円形状に形成され、その内壁には金属基盤下面側及び金属基盤上面側の何れか一方側に雌ねじ部が形成されていると共に他方側に位置決め段差を有する係止部が形成されており、また、給電端子は上記金属基盤の上下面間を貫通する柱状体で形成されており、更に、絶縁保持部材は、その横断面外周形状が円形状であると共にその中空部内に上記給電端子が嵌着された筒状体で形成され、その外周壁の金属基盤下面側及び金属基盤上面側の何れか一方側に上記貫通孔の雌ねじ部に螺合する雄ねじ部が形成されていると共に他方側に上記貫通孔に形成した係止部の位置決め段差に係止する位置決め段差を有する頚部が形成されており、上記絶縁保持部材の雄ねじ部を貫通孔の雌ねじ部に螺合させて貫通孔内に給電端子と絶縁保持部材とを固定するようにした電極構造を挙げることができる。
【００２０】
この第二の構成例において、柱状体で形成された給電端子と筒状体で形成された絶縁保持部材とは、絶縁保持部材の中空部内に給電端子が嵌合され固着されていればよく、給電端子の横断面形状については、例えば円形、三角形、四角形、五角形以上の多角形等どのような形状であってもよく、また、これら給電端子と絶縁保持部材とを嵌着する方法についても、これら給電端子と絶縁保持部材とをそれぞれ別個に形成し、絶縁保持部材の中空部内に給電端子を嵌合して接着剤等の手段で固着してもよいほか、給電端子を中子とするインサート成形により絶縁保持部材を成形することにより嵌着してもよい。
【００２１】
なお、この第二の構成例においても、金属基盤の上下面間に差圧が生じるのを防止する必要がある場合には、好ましくは、外部電源と接続した給電ピン等を有し、この金属基盤を載置する支持台側と上記絶縁保持部材との間に電気絶縁性及び弾性を有するＯ-リング等のシール部材を介装するのがよい。
【００２２】
この第二の構成例に係る静電チャックの電極構造によれば、その組立時には、中空部内に給電端子が嵌着された絶縁保持部材を、その雄ねじ部を貫通孔の雌ねじ部に螺合させてこの貫通孔内に嵌合し、貫通孔内の係止部に形成された位置決め段差と絶縁保持部材の頚部に形成された位置決め段差とを係止させて貫通孔内で絶縁保持部材を位置決めすればよく、また、その分解時には絶縁保持部材の雄ねじ部と貫通孔の雌ねじ部との間の螺子結合を解除し、貫通孔内から給電端子と共に絶縁保持部材を取り外せばよい。
【００２３】
上記２つの構成例で説明した本発明における金属基盤は、その材質がアルミニウム又はアルミニウム合金からなり、その表面をアルマイト処理することでアルマイト膜を生成したアルミニウム製金属基盤を例示することができる。また、本発明における静電チャックシートは、上記金属基盤の上面に載置され、金属基盤と共に静電チャックを構成するものである。このような静電チャックシートとしては、ポリイミドフィルム等からなる第一絶縁層、銅箔等からなる電極層、及びポリイミドフィルム等からなる第二絶縁層が順次積層して形成されたような一般的な静電チャックシートを例示することができる。また、本発明に係る静電チャックシートは、本発明における給電端子から電力供給を受けることができるために、上記電極層の一部が露出するように、給電用抜き孔等を設ける必要がある。
【００２４】
上記のような技術的手段によれば、金属基盤の上面側に静電チャックシートを積層して静電チャックを形成するにあたり、上記金属基盤の上下面間を貫通する貫通孔を設け、当該貫通孔内には、金属基盤の下面側から供給された電力を上面側に積層された静電チャックシートに供給する給電端子と、電気絶縁性材料で形成されて上記貫通孔の内壁と給電端子との間を絶縁すると共に上記給電端子を保持する絶縁保持部材を配設し、上記絶縁保持部材が貫通孔の内壁に着脱可能となるように取り付けられた静電チャックの電極構造を構成することにより、当該電極構造の組立・分解を容易に行うことができるため、使用済み静電チャックにおける金属基盤の再利用がコストを掛けずに容易に行うことができる。また、このような構成により組立てた静電チャックの電極構造によれば、金属基盤の上面側と下面側との連通を遮断することができるため、静電チャックに半導体ウエハ等の試料を保持させて真空中で処理する場合でも、金属基盤の貫通孔を介して大気が浸入し、金属基盤上面の静電チャックシートが気圧の差により上方に膨れ上がるような問題を生ずることもない。
【００２５】
【発明の実施の形態】
以下、添付図面に示す実施例に基づいて、本発明の好適な実施の形態を具体的に説明する。
実施例１
この実施例に係る静電チャックの電極構造は、図１に示したように、表面をアルマイト処理したアルミニウム製の金属基盤１の上面側に静電チャックシート２を積層して形成した静電チャック３におけるものであり、この電極構造は、上記金属基盤１の上下面間を貫通する貫通孔４と、この貫通孔４内に配設され、金属基盤１の下面側から供給された電力を上面側に積層された静電チャックシート２に供給する真ちゅう製の給電端子５と、ポリイミド樹脂であるべスペル（デュポン社製商品名）等の電気絶縁性材料で形成されて上記貫通孔４の内壁と給電端子５との間を絶縁すると共に上記給電端子５を保持する絶縁保持部材６とから構成されている。また、このような静電チャック３の電極構造において、上記絶縁保持部材６は貫通孔４の内壁に着脱可能に取り付けられている。
【００２６】
この実施例に係る貫通孔４は、横断面形状が円形で形成されたものであり、その内壁略中間位置において内方に向けて突出し、貫通孔４の全周に亘って突出寸法及び厚さ寸法が同じ大きさに形成されたフランジ部４aが設けられ、このフランジ部４aが上記貫通孔４内を金属基盤１の下面側に位置する受電側収容部４bと、金属基盤１の上面側に位置する給電側収容部４cとに区画している。
【００２７】
また、上記給電端子５は、金属基盤１の下面側に位置する高電圧直流源７から供給される電力を受け取る受電ボルト８と、上記給電側収容部４c内に配設されて静電チャックシート２に電力を供給する給電ナット９とから構成されている。上記受電ボルト８については、受電側収容部４b内に配設される受電部１０と、雄ねじが設けられ、上記受電部１０と給電ナット９とを電気的に接続する連結部１１とから形成されており、この受電部１０には、引っかけスパナ等の工具を使ってこの受電ボルト８の着脱を行うことができるように工具取り付け穴１２が設けられている。また、上記給電ナット９については、静電チャックシート２に電力を供給するための突部１３と、上記受電ボルト８と螺合する雌ねじ部１４とを設けた袋ナット状に形成されている。尚、静電チャックシート２に電力を供給するための供給ポイントとなる上記突部１３は、第一絶縁層２aとしてポリイミドフィルム、電極層２bとして電解銅箔、第二絶縁層２cとしてポリイミドフィルムとが貼り合わされて構成された静電チャックシート２における電極層２bと接合している。
【００２８】
また、上記絶縁保持部材６は、貫通孔４内の受電側収容部４b内に収容される受電部保持体１５と、給電側収容部４c内に収容される給電部保持体１６、及びこれら受電部保持体１４と給電部保持体１５との間に介装されるＯ−リング１７から構成されている。上記受電部保持体１５については、受電ボルト８における受電部１０を収容する下向開口凹部１８と、この下向開口凹部１８と連通し、上記受電ボルト８における連結部１１が挿通される連通孔１９と、貫通孔４のフランジ部４aが形成する空間部内に嵌合する突出部２０が形成されている。上記給電部保持体１６については、給電ナット９が収容される上向開口凹部２１と、この上向開口凹部２１と連通し、上記受電ボルト８における連結部１１が挿通される連通孔２２が形成されている。
【００２９】
また、Ｏ−リング１７については、上記受電部保持体１５の突出部２０と給電保持部材１６との対向面を利用して、上記受電部保持体１５と給電部保持体１６との間を気密にシールするために介装される。尚、このＯ−リング１７を介装するため、上記受電部保持体１５の突出部２０外周部には切込み溝２３が設けられている。また、上記受電ボルト８における受電部１０を下向開口凹部１８に嵌合する際に、これら受電ボルト８と受電部保持体１５との間を気密にシールするために、受電ボルト８の受電部１０と受電部保持体１５とが対向する面にリング溝２５を形成して、このリング溝２５にＯ−リング２４が介装されている。
【００３０】
この実施例においては、上記のように受電ボルト８における連結部１１が、上記受電部保持体１５及び給電部保持体１６に形成された連通孔１９及び連通孔２２内を貫通し、上記給電端子５を構成する受電ボルト８と給電ナット９との間を連結して締結すれば、受電ボルト８と給電ナット９の間に位置する絶縁保持部材６の接触面が押圧され、金属基盤１の貫通孔４内に給電端子５と絶縁保持部材６とを確実に固定することができる。また、上記給電端子５の螺子結合を解除することにより、貫通孔４内から給電端子５と絶縁保持部材６とを取り外すことも可能である。すなわち、金属基盤１の貫通孔４内に配設した給電端子５と絶縁保持部材６の着脱を容易に行うことができる静電チャック３の電極構造とすることができる。
【００３１】
上記のような電極構造を有した金属基盤１の上面には、熱可塑性ポリイミド系接着フィルム２６としてボンディングシート（新日鐵化学社製商品名：エスパネックス）を介して静電チャックシート２が貼り付けられ、この静電チャックシート２の上面には被処理体である半導体ウエハ２７が吸着保持される。また、金属基盤１は、高電圧直流源７からの電力を供給する給電ピン２９が設けられた金属基盤支持台２８と図示外のボルト等の締結部材により固定される。尚、上記給電ピン２９付近が直流高電圧印加中に真空状態になると放電を起こす恐れがあるため、上記金属基盤支持台２８と金属基盤１とを固定する際には、これらの間に隙間３０を形成し、この隙間３０には経路３１を介して空気、ヘリウム、窒素等のガスを導入して大気圧状態にされる。また、この隙間３０に導入したガスが外部に漏れないようにするために、絶縁保持部材６と金属基盤支持台２８との間にはＯ−リング３２が介装されて気密状態を保っている。
この実施例においては、静電チャックシート２上に吸着保持した半導体ウエハ２７を処理するために静電チャックシート２側を真空状態にして、上記隙間３０に空気、ヘリウム、窒素等のガスを導入した場合でも、隙間３０に導入されたガスは、Ｏ−リング３２により外部に漏れ出すことはなく、また、Ｏ−リング２４によりガスが貫通孔４を抜けて金属基盤１上面側に抜けることはないため、静電チャックシート２が気圧の差により上方に膨れ上がるような問題を生ずることはない。
【００３２】
次に、上記のように構成された実施例１に係る静電チャックの電極構造についての組立・分解手順を説明する。
先ず、フランジ部４aが形成する空間部内に上記受電部保持体１５に形成した突出部２０を嵌め込み、貫通孔４内の受電側収容部４bに受電部保持体１５を嵌合する。次に、貫通孔４内の給電側収容部４cにおいて、先に位置決めした受電部保持体１５に設けられた切込み溝２３にＯ−リング１７を配置し、給電部保持体１６を嵌合する。次いで、この給電部保持体１６の上向開口凹部２１に、雌ねじ部１４が給電部保持体１６の連通孔２２に向くようにして給電ナット９を嵌合する。次に、貫通孔４内の受電側収容部４bに収容した受電部保持体１５の下向開口凹部１８から受電ボルト８を差し込み、この受電ボルト８の連結部１１を連通孔１９及び連通孔２２に挿通させ、この連結部１１に設けた雄ねじを先に給電部保持体２１に収容された給電ナット９の雌ねじ部１４と螺合させる。この際、この受電ボルト８と受電部保持体１５との間に形成されるリング溝２５にＯ−リング２４を配置する。そして、引っかけスパナを用いて受電ボルト８を締め込み、上記給電ナット９と受電ボルト８とを締結して給電端子５を一体に組み付ける。
【００３３】
上記のようにすれば、金属基盤１の貫通孔４内に、給電端子５及び絶縁保持部材６が固定された静電チャック３の電極構造を容易に組立てることができる。また、このようにして組立てた電極構造を有した金属基盤１の上面側に静電チャックシート２を積層し、この金属基盤１を金属基盤支持台２８に固定すれば、静電チャックシート２上に半導体ウエハ２７を吸着保持させてプラズマエッチング等の処理を行うことができる。
【００３４】
次に、半導体ウエハ２７の処理後、金属基盤１の上面に貼り付けられた静電チャックシート２を剥がし取り、金属基盤支持台２８から取り外した金属基盤１の電極構造の分解手順について説明する。
先ず、引っかけスパナを使用して貫通孔４内の受電側収容部４bに収容されている受電ボルト８を緩め、一体に組み付けられた給電ナット９から抜き取り、受電ボルト８を受電部保持体１５から取り外す。次に、貫通孔４内の受電側収容部４bに嵌め込まれていた受電部保持体１５をＯ−リング２４と共に取り外し、更にＯ−リング１７も取り外す。最後に、貫通孔４内の給電側収容部４cから給電ナット９と給電部保持体１６を取り外せば、金属基盤１の貫通孔４から、給電端子５及び絶縁保持部材６を容易に分解して取り外すことができる。
【００３５】
実施例２
この実施例に係る静電チャックの電極構造は、図３に示したように実施例１と同様に、金属基盤１の上面側に静電チャックシート２を積層して形成した静電チャック３におけるものであり、この電極構造は、上記金属基盤１の上下面間を貫通する貫通孔５４と、この貫通孔５４内に配設され、金属基盤１の下面側から供給された電力を上面側に積層された静電チャックシート２に供給する真ちゅう製の給電端子５５と、ポリイミド樹脂であるベスペル（デュポン社製商品名）等の電気絶縁性材料で形成されて上記貫通孔５４の内壁と給電端子５５との間を絶縁すると共に上記給電端子５５を保持する絶縁保持部材５６とから構成されている。また、このような静電チャック３の電極構造において、上記絶縁保持部材５６は貫通孔５４の内壁に着脱可能に取り付けられている。
【００３６】
上記貫通孔５４は、横断面円形状に形成されており、その内壁については、金属基盤１の下面側に雌ねじ部５７が形成されていると共に金属基盤１の上面側に位置決め段差を有する係止部５８が形成されている。
【００３７】
上記給電端子５５は、金属基盤１の上下面間を貫通してその横断面が円形である円柱状で形成されている。また、この給電端子５５については、静電チャックシート２に電力を供給するための突部５９と、引っかけスパナ等の工具が使用できるように工具取り付け穴６０が形成されている。尚、静電チャックシート２に電力を供給するための供給ポイントとなる上記突部５９は、実施例１の場合と同様に静電チャックシート２を構成する電極層２bと接合している。
【００３８】
また、上記絶縁保持部材５６は、その横断面外周形状が円形状であって、中空部６１を有した筒状体に形成されており、この中空部６１内には上記給電端子５５が嵌着されている。この絶縁保持部材５６の外周壁については、金属基盤下面側には上記貫通孔５４に形成された雌ねじ部５７と螺合する雄ねじ部６２が形成されており、上面側には上記貫通孔５４に形成された係止部５８の位置決め段差に係止する位置決め段差を有する頚部６３が形成されている。すなわち、位置決め段差を介してこれら雄ねじ部６２と頚部６３とが隣接している。
【００３９】
上記のように、絶縁保持部材５６における中空部６１に上記給電端子５５を嵌合してエポキシ等の接着剤６４により固着し、このような絶縁保持部材５６の雄ねじ部６２を貫通孔５４の雌ねじ部５７に螺合させることで、金属基盤１の貫通孔５４内に給電端子５５と絶縁保持部材５６とを確実に固定することができる。また、上記貫通孔５４の雌ねじ部５７に螺合した絶縁保持部材５６を緩めることで、貫通孔５４内から給電端子５５を含んだ絶縁保持部材５６を取り外すことも可能である。すなわち、金属基盤１の貫通孔５４内に配設した絶縁保持部材５６の着脱を容易に行うことができる静電チャック３の電極構造とすることができる。
【００４０】
上記のような電極構造を有した金属基盤１は、実施例１と同様にしてその上面に静電チャックシート２が積層され、図示外のボルト等の締結部材により金属基盤支持台２８と固定され、また、上記静電チャックシート２の上面には被処理体である半導体ウエハ２７が吸着保持される。
この実施例においては、静電チャックシート２上に吸着保持した半導体ウエハ２７を処理するために静電チャックシート２側を真空状態にして、隙間３０に窒素ガスを導入した場合でも、隙間３０に導入されたガスは、Ｏ−リング３２により外部に漏れ出すことはなく、また、絶縁保持部材５６の中空部６１には給電端子５５が接着剤６４により嵌着されているためガスが貫通孔４を抜けて金属基盤１上面側に抜けることはなく、静電チャックシート２が気圧の差により上方に膨れ上がるような問題を生ずることはない。
【００４１】
次に、上記のように構成された実施例２に係る静電チャックの電極構造の組立・分解手順を説明する。
先ず、絶縁保持部材５６の中空部６１には、接着剤６４としてスリーボンド社製2210を使用し、給電端子５５を嵌合して固着させた。接着剤６４が十分に固化した後、給電端子５５に設けられた工具取り付け穴６０を利用し、引っかけスパナを用いて給電端子５５を嵌着した絶縁保持部材５６の雄ねじ部６２を貫通孔５４の雌ねじ部５７に螺合させる。この際、上記絶縁保持部材５６は、貫通孔５４内の係止部５８に対し、頚部６３に形成された位置決め段差を係止させ、貫通孔５４内に絶縁保持部材５６を固定した。このようにすれば、金属基盤１の貫通孔５４内に給電端子５５及び絶縁保持部材５６が固定された静電チャック３の電極構造を容易に組立てることができる。また、このようにして組立てた電極構造を有した金属基盤１の上面側に静電チャックシート２を積層し、この金属基盤１を金属基盤支持台２８に固定すれば、静電チャックシート２上に半導体ウエハ２７を吸着保持させてプラズマＣＶＤ等の処理を行うことができる。
【００４２】
次に、半導体ウエハ２７の処理後、金属基盤１の上面に貼り付けられた静電チャックシート２を剥がし取り、金属基盤支持台２８より取り外した金属基盤１の電極構造の分解手順について説明する。
給電端子５５の工具取り付け穴６０を利用して引っかけスパナにより、給電端子５５が嵌着された絶縁保持部材５６を緩めて、この絶縁保持部材５６の雄ねじ部６２と貫通孔５４の雌ねじ部５７との間の螺子結合を解除することにより、容易に貫通孔５４内から給電端子５５と共に絶縁保持部材５６を取り外すことができる。
【００４３】
【発明の効果】
本発明における静電チャックの電極構造によれば、金属基盤の貫通孔内に給電端子や絶縁保持部材を容易に組立てることができ、また、これら給電端子や絶縁保持部材について、金属基盤の貫通孔内より取り外す作業が極めて容易に行えるため、使用済み静電チャックにおける金属基盤の再利用を実質的にも可能とすることができる。
【図面の簡単な説明】
【図１】図１は、本発明に係る静電チャックの電極構造を使用した静電チャックと金属基盤支持台を示す断面図である。
【図２】図２は、図１に係る静電チャックの底面図である。
【図３】図３は、本発明に係る静電チャックの電極構造を使用した静電チャックと金属基盤支持台を示す断面図である。
【符号の説明】
１…金属基盤、２…静電チャックシート、２a…第一絶縁層（ポリイミドフィルム）、２b…電極層（電解銅箔）、２c…第二絶縁層（ポリイミドフィルム）、３…静電チャック、４…貫通孔、４a…フランジ部、４b…受電側収容部、４c…給電側収容部、５…給電端子、６…絶縁保持部材、７…高電圧直流源、８…受電ボルト、９…給電ナット、１０…受電部、１１…連結部、１２…工具取り付け穴、１３…突部、１４…雌ねじ部、１５…受電部保持体、１６…給電部保持体、１７…Ｏ−リング、１８…下向開口凹部、１９…連通孔、２０…突出部、２１…上向開口凹部、２２…連通孔、２３…切込み溝、２４…Ｏ−リング、２５…リング溝、２６…熱可塑性ポリイミド系接着フィルム（ボンディングシート）、２７…半導体ウエハ、２８…金属基盤支持台、２９…給電ピン、３０…隙間、３１…経路、３２…Ｏ−リング、５４…貫通孔、５５…給電端子、５６…絶縁保持部材、５７…雌ねじ部、５８…係止部、５９…突部、６０…工具取り付け穴、６１…中空部、６２…雄ねじ部、６３…頚部、６４…接着剤。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electrode structure of an electrostatic chuck formed by laminating an electrostatic chuck sheet on the upper surface side of a metal substrate. In particular, the present invention can not only simply supply power to the electrostatic chuck sheet but also can be used. The present invention relates to an electrode structure of an electrostatic chuck that allows only a metal substrate to be separated and taken out from the substrate and reused easily.
[0002]
[Prior art]
In recent years, in the semiconductor manufacturing process, the dry process has rapidly progressed, and apparatuses such as a plasma etching apparatus, a plasma CVD apparatus, an ion implantation apparatus, an ashing apparatus, an electron beam lithography apparatus, and an X-ray lithography apparatus are frequently used. In these apparatuses, a sample such as a semiconductor wafer is often processed in a vacuum.
[0003]
In such an apparatus, as a means for holding the sample, a mechanical chuck by a mechanical method, a vacuum chuck using a pressure difference from atmospheric pressure, or an electrostatic chuck sheet that exhibits electrostatic attraction force is used. The electrostatic chuck or the like has been proposed. However, the electrostatic chuck is considered advantageous in that the sample and the holder are held in a vacuum in a thermally uniform manner with high reliability.
[0004]
This electrostatic chuck generally has a metal base formed of a metal such as aluminum whose surface is anodized, a first insulating layer such as a polyimide layer on the upper surface of the metal base, an electrode layer such as a copper foil layer, and a polyimide layer. And an electrostatic chuck sheet formed by sequentially laminating a second insulating layer such as a direct current high voltage (high power) is applied to the electrode layer of the electrostatic chuck sheet to develop an electrostatic force. In addition, the electrode structure for supplying electric power to the electrode layer of the electrostatic chuck sheet is usually provided with a through-hole penetrating between the upper and lower surfaces of the metal substrate, and the metal structure. A power supply terminal that supplies power supplied from the lower surface side of the substrate to the electrostatic chuck sheet laminated on the upper surface side, and is formed of an electrically insulating material to insulate between the inner wall of the through hole and the power supply terminal. The power supply terminal It is constituted by an insulating holding member for lifting.
[0005]
As an electrode structure of such an electrostatic chuck, for example, an adhesive is bonded to the inner surface of the through hole of the metal substrate, and a conductive layer is included therein, and the through hole reaches the surface of the substrate. A power supply sheet that is electrically joined to the electrostatic chuck sheet at a location (Patent No. 2,581,627), a power supply hole that penetrates in the thickness direction of the susceptor (metal substrate), and an inner wall of the power supply hole And an auxiliary power supply pin provided via an insulating member between the two and the above-mentioned insulating member is bonded to the power supply hole by an epoxy adhesive, an adhesive, or an engineering plastic, or a power supply hole by adhesive or brazing A power supply slit formed in the thickness direction of a susceptor (metal substrate) formed with ceramics fixed inside (JP-A-7-74,234) or in the power supply slit Which was filled with blocking member for blocking the communication between with inserting the feed sheet and the electrostatic chuck sheet placing surface of the susceptor and the opposite side (Japanese Unexamined Patent Publication No. 7-86,381) have been proposed.
[0006]
However, these conventional electrostatic chuck electrode structures are all in a through hole (power supply hole or power supply slit) that communicates between the electrostatic chuck sheet placement surface of the susceptor (metal substrate) and the opposite side surface thereof. The power supply terminal (power supply sheet or power supply auxiliary pin) has a structure that is fixed by means such as an adhesive, so that the power supply terminal is not displaced or moved in the through hole. Although there is an advantage that power can be reliably supplied, when reusing the metal base of the used electrostatic chuck, the power supply terminal and the insulating member between the metal base and the power supply terminal are separated and removed from the metal base. There is a problem that the work is extremely difficult, and there are many cases where the metal substrate cannot be reused substantially.
[0007]
[Problems to be solved by the invention]
Therefore, the present inventors can solve the problems in the electrode structure of the conventional electrostatic chuck, and can easily assemble and disassemble the electrode structure in the electrostatic chuck. The present invention has been completed by intensively studying the electrode structure of an electrostatic chuck that can easily reuse the metal substrate in the chuck.
[0008]
Accordingly, an object of the present invention is to easily assemble an electrode structure for supplying power to an electrostatic chuck sheet in an electrostatic chuck formed by laminating an electrostatic chuck sheet on the upper surface side of a metal substrate. Another object of the present invention is to provide an electrode structure for an electrostatic chuck that can be disassembled and removed from the metal substrate.
[0009]
[Means for Solving the Problems]
That is, according to the present invention, in an electrostatic chuck formed by laminating an electrostatic chuck sheet on the upper surface side of a metal substrate, a through hole penetrating between the upper and lower surfaces of the metal substrate is disposed in the through hole. A power supply terminal for supplying power supplied from the lower surface side of the metal substrate to the electrostatic chuck sheet laminated on the upper surface side, and an insulating material between the inner wall of the through hole and the power supply terminal. In addition, the electrostatic chuck electrode structure includes an insulating holding member that holds the power supply terminal, and the insulating holding member is detachably attached to the inner wall of the through hole.
[0010]
In the present invention, the specific means for detachably attaching the insulating holding member to the inner wall of the through hole penetrating between the upper and lower surfaces of the metal substrate is not particularly limited, but preferably has the following configuration An example can be illustrated.
[0011]
That is, as a first configuration example, the through-hole penetrating the metal substrate has a power receiving side that protrudes inward at an approximately middle position of the inner wall and is positioned on the lower surface side of the metal substrate. A flange portion is provided to divide the housing portion and a power feeding side housing portion located on the upper surface side of the metal substrate, and the power feeding terminal is disposed in the power receiving side housing portion and connected to an external power source. Part, a power feeding part that is disposed in the power feeding side accommodating part and supplies power to the electrostatic chuck sheet, and a connecting part that electrically connects between the power receiving part and the power feeding part, Furthermore, the insulating holding member has a downward opening recessed portion that accommodates the power receiving portion of the power supply terminal and a communication hole that communicates with the downward opening recessed portion, and receives the power received in the power receiving side accommodating portion of the through hole. Part holding body and upward opening recessed part for accommodating the power feeding part And having a communication hole that communicates with the upward opening recess, and the power feeding unit holding body accommodated in the power feeding side accommodation unit of the through hole, and the space between the power receiving unit holding unit and the power feeding unit holding unit are hermetically sealed A sealing member that seals, and a connecting portion that connects between the power receiving portion and the power feeding portion that penetrates through the communication holes of the power receiving portion holding body and the power feeding portion holding body and constitutes the power feeding terminal. An electrode structure in which the power supply terminal and the insulating holding member are fixed in the through hole can be exemplified.
[0012]
Here, as for the cross-sectional shape of the through-hole penetrating between the upper and lower surfaces of the metal substrate, for example, any shape such as a circle, a triangle, a quadrangle, a pentagon or more polygon may be used, but from the viewpoint of workability A circular shape or a regular square shape (square) is preferable. In addition, for the flange portion that is formed at a substantially intermediate position on the inner wall of the through hole and divides the inside of the through hole into a power receiving side accommodating portion and a power feeding side accommodating portion, the protruding dimension and the thickness dimension are set over the entire circumference. It is good to form in the same size.
[0013]
Further, the power supply terminal composed of the power reception unit, the power supply unit, and the connection unit has a female screw portion formed in the power reception unit or the power supply unit or the power reception unit and the power supply unit. A male threaded part that is screwed into the female threaded part of the power receiving part and / or the power feeding part is formed in the coupling part that connects between them. During assembly, the male threaded part of the coupling part is connected to the female threaded part of the power receiving part and / or the power feeding part. In addition, when disassembling, the screw connection between the male screw portion of the connecting portion and the female screw portion of the power receiving portion and / or the power feeding portion can be released and separated.
[0014]
Here, with respect to the power reception unit, the power supply unit, and the connection unit, the connection unit is passed through the communication hole of the power reception unit holding body and the power supply unit holding body, and the male screw portion of the connection unit is connected to the power reception unit and / or It only needs to be able to be screwed into the female thread part of the power feeding part.For example, the power receiving part and the base part of the connecting part are integrally connected, and a male screw part is provided at the tip of the connecting part to form a headed bolt, The power feeding part is provided with a female screw part and formed into a cap nut shape, and either the power receiving part and the connecting part side or the power feeding part side is rotated so that the male screw part of the connecting part is screwed into the female screw part of the power feeding part. On the contrary, the power feeding portion and the base portion of the connecting portion are integrally connected, and a male screw portion is provided at the tip of the connecting portion to form a headed bolt, and a female screw portion is provided in the power receiving portion. Formed in the shape of a cap nut The male screw part of the connecting part may be screwed into the female screw part of the power receiving part by rotating any of the parts, and the power receiving part and the power feeding part are provided with female screw parts cut in opposite directions. In addition, male screw parts cut in opposite directions are provided at both ends of the connecting part, and the power receiving part and / or the power feeding part are rotated to rotate the power receiving part, the power feeding part, and the connecting part. You may make it screw | thread between.
[0015]
Furthermore, the power receiving unit holding body and the power feeding unit holding body constituting the insulating holding member are formed of a material such as an electrically insulating synthetic resin or ceramic, and preferably, either one or both of the through hole is formed in the insulating holding member. The projecting portion having opposing surfaces facing each other at positions close to each other is formed by fitting into a space portion formed by the flange portion of the power receiving portion, and holding the power receiving unit and the power feeding unit using the opposing surfaces of the projecting portion. It is preferable to provide a sealing member that hermetically seals between the body.
[0016]
Further, the sealing member constituting the insulating holding member is formed of a material such as synthetic resin or rubber having electric insulation and predetermined elasticity, and between the power receiving unit and the power feeding unit constituting the power feeding terminal. Any device may be used as long as it is sandwiched between the power receiving unit holding body and the power feeding unit holding body under pressure and hermetically seals between the power receiving unit holding body and the power feeding unit holding body when connected by the connecting unit. Examples thereof include O-rings and flat packings.
[0017]
In this first configuration example, when it is necessary to prevent the occurrence of differential pressure between the upper and lower surfaces of the metal substrate, it is preferable to have power supply pins connected to an external power source and mount this metal substrate. Between the receiving support side of the insulating holding member and the power receiving unit holding body of the insulating holding member, and between the power receiving unit or the power feeding unit constituting the power feeding terminal, respectively. It is preferable to interpose a seal member such as an O-ring having electrical insulation and elasticity.
The power receiving unit holding body and the power feeding unit holding body constituting the insulating holding member and the power receiving unit and the power feeding unit constituting the power feeding terminal are the power receiving unit holding body and the power receiving unit and / or the power feeding unit holding body and the power feeding unit. The power receiving unit holding body and / or the power feeding unit holding body may be formed separately in the through-hole in the power receiving side accommodating portion and / or in the power feeding side accommodating portion. The holding body and the power receiving unit and / or the power feeding unit holding body and the power feeding unit may be formed integrally with the power receiving unit and / or the power feeding unit by means such as insert molding when the power receiving unit holding body and / or the power feeding unit holding body is formed. Good.
[0018]
According to the electrode structure of the electrostatic chuck according to such a first configuration example, at the time of assembly, the power receiving unit holding body, the power feeding unit holding body and the seal member, and the power feeding terminal that constitute the insulating holding member in the through hole The power receiving unit, the power feeding unit, and the coupling unit that constitute the power supply unit are incorporated, and the male threaded portion of the coupling unit may be screwed into the female power receiving unit and / or the female threaded portion of the power feeding unit and fastened. The screw connection between the male screw part of the part and the power receiving part and / or the female screw part of the power feeding part is released, and the power receiving part, the power feeding part and the connecting part, the power receiving part holding body, the power feeding part holding body and the seal from the inside of the through hole What is necessary is just to remove a member.
[0019]
Further, as a second configuration example, the through-hole penetrating the metal base is formed in a circular cross section, and the inner wall is formed with a female thread portion on either the metal base lower surface side or the metal base upper surface side. And a latching portion having a positioning step is formed on the other side, the power supply terminal is formed of a columnar body penetrating between the upper and lower surfaces of the metal base, and the insulating holding member is The outer circumferential shape of the cross section is circular and the cylindrical body is formed with the power supply terminal fitted in the hollow portion, and the outer peripheral wall is formed on either the metal substrate lower surface side or the metal substrate upper surface side. A male thread part that is screwed into the female thread part of the through hole is formed, and a neck part having a positioning step that engages with a positioning step of the locking part formed in the through hole is formed on the other side, and the insulation holding Insert the male screw part of the member Screwed into the screw portion can be given to the electrode structure to fix the insulating holder and the power supply terminal in the through hole.
[0020]
In this second configuration example, the power supply terminal formed of the columnar body and the insulating holding member formed of the cylindrical body may be configured so that the power supply terminal is fitted and fixed in the hollow portion of the insulation holding member. As for the cross-sectional shape of the power supply terminal, for example, any shape such as a circle, a triangle, a quadrangle, a polygon more than a pentagon, and the method for fitting the power supply terminal and the insulating holding member, In addition to forming the power supply terminal and the insulating holding member separately and fitting the power supply terminal in the hollow portion of the insulation holding member and fixing them by means of an adhesive or the like, an insert having the power supply terminal as a core You may fit by shape | molding an insulation holding member by shaping | molding.
[0021]
Also in this second configuration example, when it is necessary to prevent the occurrence of differential pressure between the upper and lower surfaces of the metal substrate, it is preferable to have a power supply pin connected to an external power source. It is preferable to interpose a sealing member such as an O-ring having electrical insulation and elasticity between the support base on which the base is placed and the insulating holding member.
[0022]
According to the electrode structure of the electrostatic chuck according to the second configuration example, at the time of assembling, the insulating holding member having the feeding terminal fitted in the hollow portion is screwed into the female screw portion of the through hole. The insulating holding member is positioned in the through hole by engaging the positioning step formed in the locking portion in the through hole with the positioning step formed in the neck portion of the insulating holding member. What is necessary is just to cancel | release the screw coupling between the external thread part of an insulation holding member and the internal thread part of a through-hole at the time of the decomposition | disassembly, and to remove an insulation holding member with a power feeding terminal from the inside of a through-hole.
[0023]
The metal substrate in the present invention described in the above two configuration examples can be exemplified by an aluminum metal substrate in which the material is made of aluminum or an aluminum alloy and the surface thereof is anodized to form an alumite film. The electrostatic chuck sheet in the present invention is placed on the upper surface of the metal substrate and constitutes an electrostatic chuck together with the metal substrate. Such an electrostatic chuck sheet is generally formed by sequentially laminating a first insulating layer made of polyimide film or the like, an electrode layer made of copper foil or the like, and a second insulating layer made of polyimide film or the like. An electrostatic chuck sheet can be exemplified. In addition, since the electrostatic chuck sheet according to the present invention can be supplied with power from the power supply terminal according to the present invention, it is necessary to provide a feed hole or the like so that a part of the electrode layer is exposed. .
[0024]
According to the technical means as described above, when forming an electrostatic chuck by laminating an electrostatic chuck sheet on the upper surface side of the metal substrate, a through-hole penetrating between the upper and lower surfaces of the metal substrate is provided, In the hole, a power supply terminal for supplying electric power supplied from the lower surface side of the metal base to the electrostatic chuck sheet laminated on the upper surface side, an inner wall of the through hole and a power supply terminal formed of an electrically insulating material, An insulating holding member for holding the power supply terminal is disposed, and the electrode structure of the electrostatic chuck is configured such that the insulating holding member is detachably attached to the inner wall of the through hole. Since the electrode structure can be easily assembled and disassembled, the metal substrate in the used electrostatic chuck can be easily reused without cost. In addition, according to the electrode structure of the electrostatic chuck assembled by such a configuration, it is possible to block the communication between the upper surface side and the lower surface side of the metal substrate, so that the electrostatic chuck holds a sample such as a semiconductor wafer. Even when processing in a vacuum, there is no problem that air enters through the through holes of the metal substrate and the electrostatic chuck sheet on the upper surface of the metal substrate swells upward due to the difference in atmospheric pressure.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be specifically described based on examples shown in the accompanying drawings.
Example 1
As shown in FIG. 1, the electrode structure of the electrostatic chuck according to this embodiment is an electrostatic chuck formed by laminating an electrostatic chuck sheet 2 on the upper surface side of an aluminum metal base 1 whose surface is anodized. 3, the electrode structure includes a through-hole 4 penetrating between the upper and lower surfaces of the metal substrate 1, and electric power provided from the lower surface side of the metal substrate 1. An inner wall of the through-hole 4 formed of an electrically insulating material such as brass power supply terminal 5 supplied to the electrostatic chuck sheet 2 laminated on the side and Vespel (trade name, manufactured by DuPont), which is a polyimide resin. And an insulating holding member 6 that holds the power supply terminal 5. In the electrode structure of the electrostatic chuck 3, the insulating holding member 6 is detachably attached to the inner wall of the through hole 4.
[0026]
The through-hole 4 according to this embodiment has a circular cross-sectional shape, and protrudes inward at a substantially intermediate position of the inner wall, and the protruding dimension and thickness over the entire circumference of the through-hole 4. A flange portion 4 a having the same size is provided, and the flange portion 4 a is provided on the power receiving side accommodating portion 4 b located on the lower surface side of the metal substrate 1 in the through hole 4 and on the upper surface side of the metal substrate 1. It divides into the electric power feeding side accommodating part 4c located.
[0027]
The power supply terminal 5 is disposed in the power receiving side receiving portion 4c and the power receiving bolt 8 for receiving power supplied from the high voltage DC source 7 located on the lower surface side of the metal substrate 1. The electrostatic chuck sheet 2 and a power supply nut 9 for supplying power to the power source 2. The power receiving bolt 8 is formed of a power receiving unit 10 disposed in the power receiving side accommodating portion 4b, and a connecting portion 11 that is provided with a male screw and electrically connects the power receiving unit 10 and the power feeding nut 9. The power receiving unit 10 is provided with a tool mounting hole 12 so that the power receiving bolt 8 can be attached and detached using a tool such as a hook spanner. Further, the power supply nut 9 is formed in a cap nut shape provided with a protrusion 13 for supplying electric power to the electrostatic chuck sheet 2 and a female screw portion 14 screwed into the power receiving bolt 8. The protrusion 13 serving as a supply point for supplying power to the electrostatic chuck sheet 2 includes a polyimide film as the first insulating layer 2a, an electrolytic copper foil as the electrode layer 2b, and a polyimide film as the second insulating layer 2c. Is bonded to the electrode layer 2b of the electrostatic chuck sheet 2 formed by bonding.
[0028]
The insulating holding member 6 includes a power receiving unit holding body 15 accommodated in the power receiving side accommodating portion 4b in the through hole 4, a power feeding unit holding body 16 accommodated in the power feeding side accommodating portion 4c, and the power receiving units. It is comprised from the O-ring 17 interposed between the part holding body 14 and the electric power feeding part holding body 15. FIG. The power receiving unit holder 15 has a downward opening recess 18 that houses the power receiving unit 10 in the power receiving bolt 8 and a communication hole that communicates with the downward opening recess 18 and through which the connecting portion 11 in the power receiving bolt 8 is inserted. 19 and a protrusion 20 that fits in a space formed by the flange 4a of the through hole 4 is formed. The power supply unit holder 16 is formed with an upward opening recess 21 in which the power supply nut 9 is accommodated, and a communication hole 22 that communicates with the upward opening recess 21 and through which the connection portion 11 of the power receiving bolt 8 is inserted. Has been.
[0029]
Further, the O-ring 17 is hermetically sealed between the power receiving unit holding body 15 and the power feeding unit holding body 16 by using a facing surface between the protruding portion 20 of the power receiving unit holding body 15 and the power feeding holding member 16. To be sealed. In order to interpose the O-ring 17, a cut groove 23 is provided in the outer peripheral portion of the protruding portion 20 of the power receiving unit holding body 15. Further, when the power receiving unit 10 of the power receiving bolt 8 is fitted into the downward opening recess 18, the power receiving unit of the power receiving bolt 8 is hermetically sealed between the power receiving bolt 8 and the power receiving unit holder 15. A ring groove 25 is formed on the surface where the power receiving unit holder 15 and the power receiving unit 15 face each other, and an O-ring 24 is interposed in the ring groove 25.
[0030]
In this embodiment, the connecting portion 11 of the power receiving bolt 8 passes through the communication hole 19 and the communication hole 22 formed in the power receiving portion holding body 15 and the power feeding portion holding body 16 as described above, and the power feeding terminal. When the power receiving bolt 8 and the power supply nut 9 constituting the power supply 5 are connected and fastened, the contact surface of the insulating holding member 6 positioned between the power receiving bolt 8 and the power supply nut 9 is pressed, and the metal substrate 1 is penetrated. The power supply terminal 5 and the insulating holding member 6 can be securely fixed in the hole 4. Moreover, it is also possible to remove the power supply terminal 5 and the insulating holding member 6 from the through hole 4 by releasing the screw connection of the power supply terminal 5. That is, the electrode structure of the electrostatic chuck 3 that can easily attach and detach the power supply terminal 5 and the insulating holding member 6 disposed in the through hole 4 of the metal substrate 1 can be obtained.
[0031]
On the upper surface of the metal substrate 1 having the electrode structure as described above, an electrostatic chuck sheet 2 is attached as a thermoplastic polyimide adhesive film 26 via a bonding sheet (trade name: Espanex, manufactured by Nippon Steel Chemical Co., Ltd.). The semiconductor wafer 27 as the object to be processed is attracted and held on the upper surface of the electrostatic chuck sheet 2. Further, the metal substrate 1 is fixed by a metal substrate support 28 provided with a power supply pin 29 for supplying power from the high voltage DC source 7 and a fastening member such as a bolt (not shown). It should be noted that when the vicinity of the power supply pin 29 is in a vacuum state while a DC high voltage is being applied, there is a possibility of causing a discharge. Therefore, when the metal base support 28 and the metal base 1 are fixed, there is a gap 30 between them. In this gap 30, a gas such as air, helium, nitrogen, or the like is introduced into the gap 30 through the path 31 to be in an atmospheric pressure state. Further, in order to prevent the gas introduced into the gap 30 from leaking to the outside, an O-ring 32 is interposed between the insulating holding member 6 and the metal base support base 28 to maintain an airtight state. .
In this embodiment, in order to process the semiconductor wafer 27 attracted and held on the electrostatic chuck sheet 2, the electrostatic chuck sheet 2 side is evacuated and a gas such as air, helium or nitrogen is introduced into the gap 30. Even in this case, the gas introduced into the gap 30 does not leak to the outside through the O-ring 32, and the gas does not pass through the through hole 4 and escape to the upper surface side of the metal substrate 1 by the O-ring 24. Therefore, there is no problem that the electrostatic chuck sheet 2 swells upward due to a difference in atmospheric pressure.
[0032]
Next, assembly / disassembly procedures for the electrode structure of the electrostatic chuck according to the first embodiment configured as described above will be described.
First, the protruding portion 20 formed on the power receiving portion holding body 15 is fitted into the space formed by the flange portion 4 a, and the power receiving portion holding body 15 is fitted into the power receiving side accommodating portion 4 b in the through hole 4. Next, in the power supply side accommodating portion 4c in the through hole 4, the O-ring 17 is disposed in the cut groove 23 provided in the previously received power receiving portion holding body 15, and the power feeding portion holding body 16 is fitted. Next, the power supply nut 9 is fitted into the upward opening recess 21 of the power supply unit holding body 16 so that the female screw portion 14 faces the communication hole 22 of the power supply unit support body 16. Next, the power receiving bolt 8 is inserted from the downward opening recessed portion 18 of the power receiving unit holding body 15 accommodated in the power receiving side accommodating unit 4 b in the through hole 4, and the connecting portion 11 of the power receiving bolt 8 is connected to the communication hole 19 and the communication hole 22. The male screw provided in the connecting portion 11 is screwed into the female screw portion 14 of the power supply nut 9 accommodated in the power supply portion holding body 21 first. At this time, an O-ring 24 is disposed in a ring groove 25 formed between the power receiving bolt 8 and the power receiving unit holder 15. Then, the power receiving bolt 8 is tightened using a hook spanner, the power feeding nut 9 and the power receiving bolt 8 are fastened, and the power feeding terminal 5 is assembled integrally.
[0033]
In this manner, the electrode structure of the electrostatic chuck 3 in which the power supply terminal 5 and the insulating holding member 6 are fixed in the through hole 4 of the metal substrate 1 can be easily assembled. Further, if the electrostatic chuck sheet 2 is laminated on the upper surface side of the metal substrate 1 having the electrode structure assembled in this way and this metal substrate 1 is fixed to the metal substrate support 28, the electrostatic chuck sheet 2 The semiconductor wafer 27 can be adsorbed and held to perform a process such as plasma etching.
[0034]
Next, a procedure for disassembling the electrode structure of the metal substrate 1 after peeling the electrostatic chuck sheet 2 attached to the upper surface of the metal substrate 1 after the processing of the semiconductor wafer 27 and removing it from the metal substrate support 28 will be described.
First, using a hook spanner, the power receiving bolt 8 accommodated in the power receiving side accommodating portion 4b in the through hole 4 is loosened and extracted from the power supply nut 9 assembled integrally, and the power receiving bolt 8 is removed from the power receiving portion holding body 15. Remove. Next, the power receiving unit holding body 15 fitted into the power receiving side accommodating portion 4b in the through hole 4 is removed together with the O-ring 24, and the O-ring 17 is also removed. Finally, if the power supply nut 9 and the power supply unit holding body 16 are removed from the power supply side accommodating portion 4c in the through hole 4, the power supply terminal 5 and the insulating holding member 6 can be easily disassembled from the through hole 4 of the metal substrate 1. Can be removed.
[0035]
Example 2
As shown in FIG. 3, the electrode structure of the electrostatic chuck according to this embodiment is the same as that of the first embodiment in the electrostatic chuck 3 formed by laminating the electrostatic chuck sheet 2 on the upper surface side of the metal substrate 1. This electrode structure has a through-hole 54 that penetrates between the upper and lower surfaces of the metal substrate 1, and the electric power supplied from the lower surface side of the metal substrate 1 to the upper surface side. The power supply terminal 55 made of brass to be supplied to the laminated electrostatic chuck sheet 2 and the inner wall of the through-hole 54 and the power supply terminal formed of an electrically insulating material such as Vespel (DuPont product name) which is a polyimide resin. And an insulating holding member 56 that holds the power supply terminal 55. In the electrode structure of the electrostatic chuck 3, the insulating holding member 56 is detachably attached to the inner wall of the through hole 54.
[0036]
The through-hole 54 is formed in a circular cross section, and the inner wall of the through-hole 54 is formed with a female screw portion 57 on the lower surface side of the metal substrate 1 and a positioning step on the upper surface side of the metal substrate 1. A portion 58 is formed.
[0037]
The power supply terminal 55 is formed in a cylindrical shape that penetrates between the upper and lower surfaces of the metal substrate 1 and has a circular cross section. The power supply terminal 55 is formed with a projection 59 for supplying power to the electrostatic chuck sheet 2 and a tool mounting hole 60 so that a tool such as a hook spanner can be used. The protrusion 59 serving as a supply point for supplying electric power to the electrostatic chuck sheet 2 is joined to the electrode layer 2b constituting the electrostatic chuck sheet 2 as in the first embodiment.
[0038]
The insulating holding member 56 has a circular cross-sectional outer peripheral shape and is formed in a cylindrical body having a hollow portion 61, and the power supply terminal 55 is fitted in the hollow portion 61. Has been. With respect to the outer peripheral wall of the insulating holding member 56, a male screw portion 62 that is screwed into a female screw portion 57 formed in the through hole 54 is formed on the lower surface side of the metal base, and the through hole 54 is formed on the upper surface side. A neck portion 63 having a positioning step for locking to the positioning step of the formed locking portion 58 is formed. That is, the male screw portion 62 and the neck portion 63 are adjacent to each other through the positioning step.
[0039]
As described above, the power supply terminal 55 is fitted into the hollow portion 61 of the insulating holding member 56 and fixed by an adhesive 64 such as epoxy, and the male screw portion 62 of the insulating holding member 56 is connected to the female screw of the through hole 54. By screwing into the portion 57, the power supply terminal 55 and the insulating holding member 56 can be reliably fixed in the through hole 54 of the metal substrate 1. Further, the insulating holding member 56 including the power supply terminal 55 can be removed from the inside of the through hole 54 by loosening the insulating holding member 56 screwed into the female screw portion 57 of the through hole 54. That is, the electrode structure of the electrostatic chuck 3 that can easily attach and detach the insulating holding member 56 disposed in the through hole 54 of the metal substrate 1 can be obtained.
[0040]
The metal substrate 1 having the electrode structure as described above has an electrostatic chuck sheet 2 laminated on the upper surface in the same manner as in the first embodiment, and is fixed to the metal substrate support base 28 by a fastening member such as a bolt not shown. In addition, a semiconductor wafer 27 as an object to be processed is attracted and held on the upper surface of the electrostatic chuck sheet 2.
In this embodiment, even when the electrostatic chuck sheet 2 side is evacuated and nitrogen gas is introduced into the gap 30 in order to process the semiconductor wafer 27 attracted and held on the electrostatic chuck sheet 2, The introduced gas does not leak to the outside through the O-ring 32, and the power supply terminal 55 is fitted in the hollow portion 61 of the insulating holding member 56 with the adhesive 64, so that the gas passes through the through hole 4. The electrostatic chuck sheet 2 does not escape to the upper surface side of the metal substrate 1 and does not cause a problem that the electrostatic chuck sheet 2 swells upward due to a difference in atmospheric pressure.
[0041]
Next, an assembly / disassembly procedure of the electrode structure of the electrostatic chuck according to the second embodiment configured as described above will be described.
First, 2210 manufactured by Three Bond Co., Ltd. was used as the adhesive 64 in the hollow portion 61 of the insulating holding member 56, and the power supply terminal 55 was fitted and fixed. After the adhesive 64 is sufficiently solidified, the male screw portion 62 of the insulating holding member 56 to which the power supply terminal 55 is fitted by using a hook spanner is used for the through hole 54 using the tool mounting hole 60 provided in the power supply terminal 55. Screwed into the female screw portion 57. At this time, the insulating holding member 56 locked the positioning step formed in the neck portion 63 with respect to the locking portion 58 in the through hole 54, and fixed the insulating holding member 56 in the through hole 54. In this way, the electrode structure of the electrostatic chuck 3 in which the power supply terminal 55 and the insulating holding member 56 are fixed in the through hole 54 of the metal substrate 1 can be easily assembled. Further, if the electrostatic chuck sheet 2 is laminated on the upper surface side of the metal substrate 1 having the electrode structure assembled in this way and this metal substrate 1 is fixed to the metal substrate support 28, the electrostatic chuck sheet 2 The semiconductor wafer 27 can be adsorbed and held to perform processing such as plasma CVD.
[0042]
Next, a procedure for disassembling the electrode structure of the metal substrate 1 after peeling the electrostatic chuck sheet 2 attached to the upper surface of the metal substrate 1 after the processing of the semiconductor wafer 27 and removing it from the metal substrate support 28 will be described.
The insulation holding member 56 to which the power supply terminal 55 is fitted is loosened by a hook spanner using the tool mounting hole 60 of the power supply terminal 55, and the male screw portion 62 of the insulation holding member 56 and the female screw portion 57 of the through hole 54. By releasing the screw connection between them, the insulating holding member 56 can be easily removed from the through hole 54 together with the power supply terminal 55.
[0043]
【The invention's effect】
According to the electrode structure of the electrostatic chuck of the present invention, the power supply terminal and the insulation holding member can be easily assembled in the through hole of the metal substrate. Since the removal work from the inside can be performed very easily, the metal substrate in the used electrostatic chuck can be substantially reused.
[Brief description of the drawings]
FIG. 1 is a sectional view showing an electrostatic chuck and a metal substrate support using the electrode structure of an electrostatic chuck according to the present invention.
FIG. 2 is a bottom view of the electrostatic chuck according to FIG.
FIG. 3 is a sectional view showing an electrostatic chuck and a metal substrate support using the electrode structure of the electrostatic chuck according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Metal substrate, 2 ... Electrostatic chuck sheet, 2a ... 1st insulating layer (polyimide film), 2b ... Electrode layer (electrolytic copper foil), 2c ... 2nd insulating layer (polyimide film), 3 ... Electrostatic chuck, DESCRIPTION OF SYMBOLS 4 ... Through-hole, 4a ... Flange part, 4b ... Power receiving side accommodating part, 4c ... Power feeding side accommodating part, 5 ... Power feeding terminal, 6 ... Insulation holding member, 7 ... High voltage direct current source, 8 ... Power receiving bolt, 9 ... Power feeding Nut, 10 ... Power receiving unit, 11 ... Connecting portion, 12 ... Tool mounting hole, 13 ... Projection, 14 ... Female screw part, 15 ... Power receiving unit holding body, 16 ... Power feeding unit holding body, 17 ... O-ring, 18 ... Downward opening recess, 19 ... communicating hole, 20 ... projecting portion, 21 ... upward opening recessed portion, 22 ... communicating hole, 23 ... cut groove, 24 ... O-ring, 25 ... ring groove, 26 ... thermoplastic polyimide adhesive Film (bonding sheet) 27 ... Semiconductor wafer 28 ... Metal Board support base, 29 ... feed pin, 30 ... gap, 31 ... path, 32 ... O-ring, 54 ... through hole, 55 ... feed terminal, 56 ... insulation holding member, 57 ... female screw part, 58 ... locking part, 59 ... Projection, 60 ... Tool mounting hole, 61 ... Hollow part, 62 ... Male screw part, 63 ... Neck part, 64 ... Adhesive.

Claims

In the electrostatic chuck formed by laminating an electrostatic chuck sheet on the upper surface side of the metal substrate, a through hole penetrating between the upper and lower surfaces of the metal substrate and the lower surface side of the metal substrate disposed in the through hole A power supply terminal for supplying the power supplied from the electrostatic chuck sheet laminated on the upper surface side, and insulating between the inner wall of the through-hole and the power supply terminal formed of an electrically insulating material. It is an electrode structure of an electrostatic chuck composed of an insulating holding member for holding,
The through-hole penetrating the metal substrate projects inwardly at a substantially intermediate position on the inner wall, and is positioned on the upper surface side of the metal substrate and the power receiving side accommodating portion positioned on the lower surface side of the metal substrate. A flange section is provided that divides the power supply side receiving section.
The power supply terminal includes a power receiving unit disposed in the power receiving side housing and connected to an external power source, a power feeding unit disposed in the power feeding side housing and supplying power to the electrostatic chuck sheet, and The power receiving unit and the power feeding unit are configured to be connected to each other, and the power receiving unit and the connecting unit are integrally formed. The power feeding portion is provided with a female screw portion that is screwed to the male screw portion, or the power feeding portion and the connecting portion are integrally formed, and the male screw portion is provided at the tip of the connecting portion, A female screw portion that is screwed into the male screw portion is provided, or a female screw portion that is cut in opposite directions is provided in the power receiving portion and the power feeding portion, and both ends of the connecting portion are cut in opposite directions. There is a male thread,
Furthermore, the insulating holding member has a downward opening recessed portion that accommodates the power receiving portion of the power supply terminal and a communication hole that communicates with the downward opening recessed portion, and receives the power received in the power receiving side accommodating portion of the through hole. A power supply unit holder having a portion holding body, a communication hole communicating with the upward opening concave portion and having an upward opening concave portion for accommodating the power feeding portion, and housed in the power feeding side housing portion of the through hole; It is composed of a seal member that hermetically seals between the power receiving unit holding body and the power feeding unit holding body,
By connecting the female screw part and the male screw part, a connection for connecting between the power receiving part and the power feeding part that penetrates the communication holes of the power receiving part holding body and the power feeding part holding body and constitutes the power feeding terminal. An electrode structure of an electrostatic chuck, wherein a power supply terminal and an insulating holding member are fixed in the through hole by a portion, and the insulating holding member is detachably attached to an inner wall of the through hole.