JP3565480B2

JP3565480B2 - Substrate polishing method and substrate polishing apparatus

Info

Publication number: JP3565480B2
Application number: JP28605898A
Authority: JP
Inventors: 英則中川; 順治高下
Original assignee: Canon Inc
Current assignee: Canon Inc
Priority date: 1998-09-22
Filing date: 1998-09-22
Publication date: 2004-09-15
Anticipated expiration: 2018-09-22
Also published as: JP2000094302A

Description

【０００１】
【発明の属する技術分野】
本発明は、ガラスや半導体等の基板を平坦に研磨する基板研磨方法および基板研磨装置に関するものである。
【０００２】
【従来の技術】
近年、半導体の高集積化の要求が高まるとともに化学機械研磨（ＣＭＰ）による平坦化技術が注目されている。このＣＭＰにより、リソグラフィーの可能性を原理的な限界点まで広げるために不可欠なデバイス表面の平坦化や、多層配線のための埋め込み構造が可能となる。
【０００３】
従来の化学機械研磨（ＣＭＰ）装置は、図５に図示するように、基板１０１を着脱自在に保持し基板の裏面から加圧する基板保持具１０２と、研磨シート１０４を貼り付けた定盤１０５と、研磨シート１０４上に研磨液１０８を供給するノズル１０９を備え、定盤１０５を回転軸１０６を介して回転させ、定盤１０５上の研磨シート１０４上に基板１０１を当接させるとともに、基板保持具１０２により基板１０１をその裏面から加圧した状態で基板１０１を回転させ、かつノズル１０９から研磨液１０８を研磨シート１０４上に滴下しつつ化学機械研磨を行なうものであり、研磨液の化学的作用と砥粒の物理的作用を利用して基板研磨面を平坦化させている。
【０００４】
化学機械研磨（ＣＭＰ）は、基板研磨面と研磨シートの接触状態がそのまま研磨量に影響するため、基板研磨面を平坦に研磨するには基板研磨面全面を均一な圧力で研磨シートに押し付ける必要がある。基板全面に均一な接触圧力を得るための手段として種々の工夫がなされており、特開平０９−２６０３１６号公報には、基板研磨面と研磨シートとの接触圧力を検出しつつ単一もしくは多数のアクチュエータなどの加圧体の押し付ける力を研磨圧力が均一になるように制御して基板を加圧する方法が開示されている。
【０００５】
また、特開平０９−１４１５５０号公報には、基板または基板保持部品で密閉されるような圧力容器を有する研磨ヘッドにより、基板裏面または基板保持部品を圧力容器内の流体圧で加圧し基板研磨面を研磨シートに押し付ける基板加圧方法が開示されている。
【０００６】
【発明が解決しようとする課題】
ところで、化学機械研磨（ＣＭＰ）においては、基板研磨面を均一に研磨除去するためには、基板裏面から基板を加圧することにより、基板研磨面と研磨シートの間に発生する研磨圧力が基板全面で均一にならなければならない。また、研磨進行後、研磨面内で除去量にむらが生じた場合、むらの形状に合わせて選択的に除去量を大きくあるいは小さく取るような圧力操作が必要となる。このような背景から、基板を均一に加圧しかつ加圧力の強弱あるいは有無を制御することができる加圧方法が必要となる。
【０００７】
しかしながら、前述した特開平０９−１４１５５０号公報に開示された方法では、装置に流体をシールする機構や流体の制御手段、流体供給装置を必要とするなど、装置が複雑となり大型になってしまい、さらに、研磨進行後、研磨除去量にむらが生じた場合、このむらをなくするようにむら形状に合わせて研磨除去するような加圧を行なうことができないという問題点がある。
【０００８】
また、前述した特開平０９−２６０３１６号公報に開示された方法では、アクチュエータを駆動させるため、装置が大型となってしまうという問題点があり、さらに、基板が大版化すると、基板全面の接触圧力を制御するためにアクチュエータの数を増やさないといけないため、さらに装置が大型となり、基板の大版化に対応することが難しい。また、加圧体の間隔を小さくすれば細かい圧力制御が可能となるけれども、加圧体の数を増やさないといけないため、これも装置を大型化してしまう。
【０００９】
さらに、多数の加圧体を用いて基板裏面から加圧する際に、各加圧体における基板裏面に接触する端面が平面であると、基板裏面に接触している各加圧体の面内で圧力の片寄りが生じ、所望の研磨圧力を得ることができない。
【００１０】
そこで、本発明は、上記従来技術の有する未解決な課題に鑑みてなされたものであって、従来のように装置を大型、複雑にすることなく、基板全面を均一に加圧することができるとともに基板の膜厚むらや研磨進行後の研磨量のむら形状に合わせて膜厚むらを除去するように研磨圧力を制御することができ、かつ基板の大版化に対応することが容易な基板研磨方法および基板研磨装置を提供することを目的とするものである。
【００１１】
【課題を解決するための手段】
上記の目的を達成するために、本発明の基板研磨方法は、研磨シートを貼り付けた定盤を回転させるとともに、基板を前記研磨シートに基板裏面から加圧して押し付けながら回転させて研磨し、ガラスや半導体等の基板の凹凸を平坦化する基板研磨方法において、基板裏面から基板を研磨シートに押し付ける多数の加圧体によりそれぞれ等しい大きさの力でかつ点接触によって前記基板を前記研磨シートに対して加圧し、加圧体の配置または加圧体同士の間隔を調整することにより、前記基板の研磨面と前記研磨シートの間に発生する研磨圧力を制御することを特徴とする。
【００１２】
本発明の基板研磨方法においては、多数の加圧体による基板の加圧範囲よりも大きく形成された流体を収納した流体袋体を介して加圧体を加圧し、全ての加圧体に等しい加圧力を与えることが好ましく、また、多数の加圧体は加圧体を着脱自在に保持しうる穴を一定間隔をもって多数形成した加圧体保持部材により保持されていることが好ましい。
【００１３】
本発明の基板研磨方法においては、基板の研磨面の膜厚形状に応じ、最も膜厚の厚い部分に対しては加圧体を最密状態に配列させ、膜厚が薄くなるごとに加圧体の間隔を順次大きくして配列するように加圧体を配設して、前記基板の研磨を行なうことができる。
【００１４】
本発明の基板研磨方法においては、基板の研磨面を研磨シートに押し付けながら相対的に回転させて研磨する際に前記研磨シート上に研磨剤を供給することが好ましい。
【００１５】
そして、本発明の基板研磨装置は、研磨シートを貼り付けた定盤を回転させるとともに、基板を前記研磨シートに基板裏面から加圧して押し付けながら回転させて研磨し、ガラスや半導体等の基板の凹凸を平坦化する基板研磨装置において、基板裏面から基板を研磨シートに押し付ける多数の加圧体と、該多数の加圧体を着脱自在に保持する加圧体保持部材と、該加圧体保持部材に保持された多数の加圧体のそれぞれに対して等しい加圧力を与える荷重手段とを備え、基板の研磨面形状に応じて前記加圧体の配置や間隔を調節して前記基板の研磨面と研磨シートの間に発生する研磨圧力を制御しうるように構成したことを特徴とする。
【００１６】
本発明の基板研磨装置においては、加圧体は基板裏面に対して点接触状に当接する形状を有することが好ましく、また、加圧体保持部材は加圧体を着脱自在にそれぞれ保持しうる多数の穴が一定間隔をもって形成されていることが好ましく、さらにまた、荷重手段は、多数の加圧体による基板の加圧範囲よりも大きく形成された流体を収納した流体袋体と荷重とを備え、前記流体袋体を介して前記加圧体を加圧することが好ましい。
【００１７】
本発明の基板研磨装置においては、加圧体と基板との間に板状の弾性体を介在させることが好ましい。
【００１８】
本発明の基板研磨装置においては、基板の研磨面の膜厚形状に応じ、最も膜厚の厚い部分に対しては加圧体を最密状態に配列させ、膜厚が薄くなるごとに加圧体の間隔を順次大きくして配列するように加圧体を配設して、前記基板の研磨を行なうことができる。
【００１９】
本発明の基板研磨装置においては、研磨シート上に研磨液を供給するノズルをさらに備えていることが好ましい。
【００２０】
【作用】
本発明の基板研磨方法および基板研磨装置によれば、各加圧体を基板に対して点接触の微小な面積で接触させることにより、各加圧体の接触部での圧力の片寄りを生じることがなく、接触点からの加圧力の分布を考慮するだけでよいので、研磨圧力の制御が容易となり、また、全ての加圧体を一つの流体袋体を介して加圧し、加圧体全てに同じ大きさの加圧力を加えることができ、加圧体の間隔や配置を調整制御することによって所望の研磨圧力を得ることができる。そのため、個々の加圧体を加圧する駆動装置が不要となり、装置を大型化や複雑化することなく、多数の加圧体を配置することが可能となり、さらに、加圧体の間隔や加圧体自体の形状を小さくすることができ、より細かい加圧操作が可能となる。
【００２１】
さらに、基板保持器の形状を基板形状に合わせることにより、どのような基板形状にも対応することができ、基板の大型化にも対応が容易である。
【００２２】
さらに、同じ加圧力を与えられた多数の加圧体により基板全面にわたって均一な研磨圧力を得ることができるとともに、基板の膜厚むらや研磨進行後の研磨量のむらがある場合にはそのむら形状を除去するように加圧体の間隔や配置を調整制御することにより膜厚むらを除去する研磨圧力を得ることができ、基板の平坦化研磨を行なうことができる。
【００２３】
【発明の実施の形態】
本発明の実施の形態を図面に基づいて説明する。
【００２４】
図１は本発明に係る基板研磨装置の一実施例の概略構成図であり、本実施例について図１を参照して説明する。
【００２５】
被研磨物であるガラスや半導体等の基板１は、リテーナーリング２内に配置された基板保持器３によって保持され、基板１の研磨面が定盤５に貼り付けられた研磨シート４と接するように配置される。研磨シート４は、耐薬品性、耐摩耗性および弾性回復力に優れたポリエステル繊維不織布または発泡ポリウレタンシートであり、定盤５は図示しない回転装置により回転軸６を介して回転駆動される。基板１は、回転ローラ７の回転により、リテーナーリング２および基板保持器３とともに研磨シート４の上で回転する。研磨液８はノズル９を通して研磨シート３上に供給される。
【００２６】
基板１の研磨面を研磨シート４に押し付けるための多数の加圧体１１は、基板１の裏面側に配置され、各加圧体１１における基板１との接触面内で圧力分布の片寄りをなくすために、理想的には基板１の裏面と点接触する構造とし、例えば、加圧体１１の基板裏面に接触する先端部の形状を針状あるいは球面状とし、加圧体１１は鉄あるいはナイロン等の材料で作製する。図１に図示する実施例では、加圧体１１の一形態として基板１に接触する端面が球面状に形成された柱状の加圧体を用いている。加圧体１１を保持する加圧体保持部材１２は、アクリル樹脂等で作製された板状体であり、加圧体１１の断面形状と同じ形状で同じ大きさの穴１２ａが多数開けられ、これらの穴１２ａは各加圧体１１を着脱自在に保持することができる構造である。加圧体保持部材１２は、図１に図示する実施例では、基板保持器３の上面に載置されており、基板１の裏面に接することがないように配置されている。加圧体保持部材１２に保持される加圧体１１同士の間隔は、研磨シート４と基板１の間に発生する研磨圧力を均一にするために、十分に小さく形成され、また、各加圧体１１の断面積も同様に十分小さいことが好ましい。
【００２７】
そして、加圧体１１の上には気体などの流体を収納した流体袋体１３が配置され、この流体袋体１３は、多数の加圧体１１による加圧範囲よりも大きく形成されている。流体袋体１３の上にさらに荷重１４を載置することにより、加圧体１１に加圧力を与える。このように、加圧体１１は、流体袋体１３を介して加圧されるために、どのような形状の荷重１４を用いても、個々の加圧体１１が基板１に与える加圧力は全て等しくなる。なお、流体袋体１３は、加圧体１１の配置された周辺部と中心部で均一に接して加圧力に差が生じないようにするために周辺部がだれないように加圧体１１が配置されている範囲で基板１と平行に保つように保持することが必要である。図１に図示する実施例では、加圧体保持部材１２の周辺部の上面に、加圧体保持部材１２の上面から出ている加圧体１１の高さと同じ高さの段差部１２ｂを設け、この段差部１２ｂによって流体袋体１３の周辺部がだれないように支持する。
【００２８】
以上のように構成された本発明の第１の実施例においては、加圧体保持部材１２に保持された多数の加圧体１１は基板１の裏面にそれぞれ点接触状に加圧することから、各加圧体１１の接触面内での圧力の片寄りを考慮するなく加圧でき、さらに、全ての加圧体１１を一つの流体袋体１３を介して荷重１４で加圧することから、基板全面に均一な研磨圧力を得ることができる。また、加圧体１１の間隔や加圧体１１自体の形状を小さくすることにより、より細かい加圧操作が可能となる。このように、個々の加圧体を加圧する駆動装置を必要とせず、装置の大型化や複雑化を避けることができる。さらに、多数の加圧体１１はそれぞれ加圧体保持部材１２に着脱自在に保持されているために、加圧体１１の配置や間隔を適宜変更することができ、これにより、基板の厚さむらや研磨進行により生じる研磨のむら形状に合わせて、加圧体１１を適宜配置することにより、厚さむらや研磨むらを除去するような研磨圧力を得ることができる。
【００２９】
次に、基板の厚さむらや研磨むらの除去に関して、図２を参照して詳細に説明する。図２は、基板と該基板を加圧する加圧体を示す模式図であって、基板の研磨進行後に研磨量にむらが生じた場合における加圧体の配置態様の一例を図示する概略図である。
【００３０】
図２において、１ａは、基板１を研磨している途中において研磨面の研磨量にむらが生じた場合に、その研磨むらの形状を高さ方向に拡大して示す研磨むら形状であり、また、加圧体として前述の実施例と同様に柱状の加圧体１１を用い、加圧体保持部材１２には加圧体を保持する穴１２ａが等ピッチで形成されており、基板１の厚さむらや研磨むらの程度に応じて、加圧体１１を穴１２ａのピッチの整数倍の間隔をもって配置することができる。
【００３１】
したがって、加圧体１１は、基板の研磨面の膜厚形状や研磨むらの形状に応じ、最も膜厚の厚い部分に対しては最も密な状態に配列され、膜厚が薄くなるごとに加圧体の間隔を順次あけていくように配列され、加圧体１１の有無により、研磨圧力を調整して研磨を行なうことができる。
【００３２】
すなわち、それぞれの加圧体１１の間隔での単位時間当たりの除去量は予め実験等により知ることができ、例えば、最も密に加圧体１１を配置して研磨を行なった時の単位時間当たりの除去量が１００ｎｍである場合には、基板１の研磨面の基準面Ｖから１００ｎｍの高さに等高線Ｚを設定し、それよりもむら厚の大きい基板の範囲をａとするとき、この範囲ａに対応する部分での加圧体１１の配置を最も密にする。同様に、加圧体保持部材１２の穴１２ａの一つ分の間隔で加圧体１１を配置して研磨を行なった場合の単位時間当たりの除去量と等しい高さの等高線Ｙを設定し、等高線Ｙより高く等高線Ｚより低い基板の範囲をｂとして、この範囲ｂに対応する部分での加圧体１１ａの配置は、加圧体保持部材１２の穴１２ａの一つおきに加圧体１１を配置する。同様にして、加圧体１１の間隔に応じた除去量と等しい高さで等高線Ｘ、Ｗ…を設定し、研磨むらを高さ方向にいくつかの層に分け、それぞれの加圧体の間隔で配置する範囲を決定する。このように、基板の研磨面の膜厚形状を測定し、その膜厚形状に応じて、加圧体の有無により、研磨圧力を調整することができ、基板の厚さむらや研磨進行後の研磨量のむら形状に合わせた適切な研磨圧力で研磨することができる。
【００３３】
また、その後にさらに研磨むらが生じている場合には、この研磨むらに対応するように加圧体を配置して研磨圧力を調整して研磨することを繰り返して、最終的に平滑な平面を得ることができる。
【００３４】
以上のように、同じ加圧力が付与される多数の加圧体においてその配置や間隔を換えることにより、基板の厚さむらや研磨進行後の研磨のむら形状に合わせて膜厚のむらを除去するような研磨圧力を得ることができる。しかも、個々の加圧体を加圧する駆動装置を必要とせず、装置の大型化や複雑化を避けることができる。
【００３５】
次に、本発明の他の実施例について、図３を参照して説明する。図３は本発明に係る基板研磨装置の他の実施例の概略構成図である。
【００３６】
本実施例においては、前述した実施例における柱状の加圧体に代えて球状体の加圧体１１ａを用いている点で前述した実施例と相異するが、その他の構成は同じであり、同一部材には同じ符号を付してある。本実施例においても、球状の加圧体１１ａは、基板１の裏面を点接触状に加圧して、各加圧体１１ａの接触面内での圧力の片寄りを考慮するなく加圧でき、さらに、全ての加圧体１１ａを一つの流体袋体１３を介して荷重１４で加圧することから、基板全面に均一な研磨圧力を得ることができる。また、加圧体１１ａ自体の形状や加圧体１１ａの間隔を小さくすることにより、より細かい加圧操作が可能であり、前述した実施例と同様の作用効果を得ることができる。
【００３７】
次に、本発明のさらに他の実施例について、図４を参照して説明する。
【００３８】
本実施例においては、図４に図示するように、基板１と加圧体１１ａの間に板状の弾性体１７を介在させたものであり、その他の構成は前述した実施例と同様であり、同一部材には同一符号をもって説明する。
【００３９】
基板１と加圧体１１ａの間に介在させる板状の弾性体１７は、基板１と同等かそれ以上の大きさを有し、例えばシリコン等で作製されたものである。このように、基板１と加圧体１１ａの間に板状の弾性体１７を介在させることにより、前述した実施例の奏する作用効果に加えて、基板１と加圧体１１ａの接触部の加圧力の集中を分散させることができ、より均一な加圧力を得ることができる。なお、本実施例においては、加圧体として球状の加圧体１１ａを用いているが、図１に図示する実施例においても、基板１と加圧体１１の間に板状の弾性体１７を介在させることにより、基板１と加圧体１１の接触部の加圧力の集中を分散させ、より均一な加圧力を得ることができることはいうまでもない。
【００４０】
【発明の効果】
以上説明したように、本発明によれば、各加圧体を基板に対して点接触させることにより、各加圧体の接触部での圧力の片寄りを生じさせることがなく、接触点からの加圧力の分布を考慮するだけでよいので、研磨圧力の制御が容易となり、また、全ての加圧体を一つの流体袋体を介して加圧し、加圧体全てに同じ大きさの加圧力を加えることができる。さらに、加圧体の間隔や配置を制御することによって所望の研磨圧力を得ることができ、個々の加圧体を加圧する駆動装置が不要となり、そのため装置が大型化や複雑化せず、多数の加圧体を配置することが可能であり、また、加圧体の間隔や加圧体自体の形状を小さくすることができ、より細かい加圧操作が可能となる。さらに、基板保持器の形状を基板形状に合わせることにより、どのような基板形状にも対応することができ、基板の大型化にも対応が容易である。
【００４１】
さらに、同じ加圧力を与えられた多数の加圧体の間隔や配置を換えることにより、均一な研磨圧力や研磨進行後の研磨量のむら形状等に合わせてむらを除去するような研磨圧力を得ることができる。
【図面の簡単な説明】
【図１】本発明に係る基板研磨装置の一実施例の概略構成図である。
【図２】本発明に係る基板研磨装置において、基板と該基板を加圧する加圧体を示す模式図であって、基板の研磨進行後に研磨量にむらが生じた場合における加圧体の配置態様の一例を図示する概略図である。
【図３】本発明に係る基板研磨装置の他の実施例の概略構成図である。
【図４】本発明に係る基板研磨装置のさらに他の実施例の概略構成図である。
【図５】従来の化学機械研磨方式による基板研磨装置の概略構成図である。
【符号の説明】
１基板
１ａ研磨むら形状
２リテーナーリング
３基板保持器
４研磨シート
５定盤
６回転軸
７回転ローラ
８研磨液
９ノズル
１１（柱状）加圧体
１１ａ（球状）加圧体
１２加圧体保持部材
１２ａ穴
１３流体袋体
１４荷重[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a substrate polishing method and a substrate polishing apparatus for polishing a substrate such as glass or a semiconductor flat.
[0002]
[Prior art]
In recent years, as the demand for higher integration of semiconductors has increased, flattening technology by chemical mechanical polishing (CMP) has attracted attention. This CMP enables flattening of the device surface, which is indispensable to extend the possibility of lithography to a theoretical limit, and an embedded structure for multilayer wiring.
[0003]
As shown in FIG. 5, a conventional chemical mechanical polishing (CMP) apparatus includes a substrate holder 102 which detachably holds a substrate 101 and presses from the back surface of the substrate, and a platen 105 on which a polishing sheet 104 is attached. A nozzle 109 for supplying a polishing liquid 108 onto the polishing sheet 104, the platen 105 is rotated via a rotating shaft 106, and the substrate 101 is brought into contact with the polishing sheet 104 on the platen 105, and The substrate 101 is rotated in a state where the substrate 101 is pressed from the back surface by the tool 102, and the chemical mechanical polishing is performed while the polishing liquid 108 is dropped on the polishing sheet 104 from the nozzle 109. The polished surface of the substrate is flattened using the action and the physical action of the abrasive grains.
[0004]
In chemical mechanical polishing (CMP), the state of contact between the substrate polishing surface and the polishing sheet directly affects the amount of polishing. Therefore, in order to polish the substrate polishing surface flat, it is necessary to press the entire surface of the substrate polishing surface against the polishing sheet with uniform pressure. There is. Various means have been devised as means for obtaining a uniform contact pressure over the entire surface of the substrate. Japanese Unexamined Patent Application Publication No. 09-260316 discloses a method for detecting a single or multiple contact pressures between a substrate polishing surface and a polishing sheet. A method of pressing a substrate by controlling a pressing force of a pressing body such as an actuator so that a polishing pressure becomes uniform is disclosed.
[0005]
Japanese Patent Application Laid-Open No. 09-141550 discloses that a back surface of a substrate or a substrate holding component is pressed by a fluid pressure in the pressure container to thereby polish a substrate polishing surface. Discloses a method of pressing a substrate against a polishing sheet.
[0006]
[Problems to be solved by the invention]
By the way, in chemical mechanical polishing (CMP), in order to uniformly remove the polished surface of the substrate, the substrate is pressed from the back surface of the substrate, so that the polishing pressure generated between the polished surface of the substrate and the polishing sheet is reduced over the entire surface of the substrate. Must be uniform. Further, if the removal amount becomes uneven in the polished surface after the polishing progresses, it is necessary to perform a pressure operation to selectively increase or decrease the removal amount according to the shape of the unevenness. From such a background, there is a need for a pressing method capable of uniformly pressing the substrate and controlling the strength or presence or absence of the pressing force.
[0007]
However, the method disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 09-141550 requires a mechanism for sealing a fluid in the device, a control device for the fluid, a fluid supply device, and the device becomes complicated and large. Further, when the polishing removal amount becomes uneven after the progress of polishing, there is a problem that it is not possible to perform pressure for polishing and removing according to the uneven shape so as to eliminate the unevenness.
[0008]
Further, the method disclosed in Japanese Patent Application Laid-Open No. 09-260316 has a problem that the size of the apparatus is increased because the actuator is driven. Since the number of actuators must be increased to control the pressure, the size of the apparatus is further increased, and it is difficult to cope with the enlargement of the substrate. Although fine pressure control is possible by reducing the interval between the pressurizing members, the number of pressurizing members must be increased, which also increases the size of the apparatus.
[0009]
Furthermore, when pressurizing from the back surface of the substrate using a large number of pressurizing bodies, if the end surface of each pressurizing body that is in contact with the backside of the substrate is a flat surface, it is within the plane of each pressurizing body that is in contact with the backside of the substrate. Deviation in pressure occurs, and a desired polishing pressure cannot be obtained.
[0010]
Therefore, the present invention has been made in view of the above-mentioned unresolved problems of the related art, and it is possible to uniformly press the entire surface of a substrate without making the apparatus large and complicated unlike the related art. A substrate polishing method capable of controlling a polishing pressure so as to remove the film thickness unevenness in accordance with the unevenness of the thickness of the substrate and the unevenness of the polishing amount after the polishing progresses, and is easy to cope with the enlargement of the substrate. And a substrate polishing apparatus.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, the substrate polishing method of the present invention is to rotate the platen to which the polishing sheet is attached, and to rotate the substrate while pressing and pressing the substrate against the polishing sheet from the back surface of the substrate, and polishing the substrate. In a substrate polishing method for flattening irregularities of a substrate such as glass or a semiconductor, the substrate is brought into contact with the polishing sheet by a point contact with a force of the same magnitude by a large number of pressing bodies pressing the substrate against the polishing sheet from the back surface of the substrate. The polishing pressure generated between the polishing surface of the substrate and the polishing sheet is controlled by applying pressure to the substrate and adjusting the arrangement of the pressing members or the interval between the pressing members.
[0012]
In the substrate polishing method of the present invention, the pressurizing body is pressurized through a fluid bag body containing a fluid formed larger than the pressurizing range of the substrate by the plurality of pressurizing bodies, and is equal to all the pressurizing bodies. It is preferable to apply a pressing force, and it is preferable that the large number of pressurizing members are held by a pressurizing member holding member in which a large number of holes capable of detachably holding the pressurizing members are formed at regular intervals.
[0013]
In the substrate polishing method of the present invention, according to the film thickness shape of the polished surface of the substrate, the pressurizing members are arranged in the densest state for the thickest portion, and the pressure is increased as the film thickness becomes smaller. The substrate can be polished by arranging the pressurizing members so that the spaces between the members are sequentially increased.
[0014]
In the substrate polishing method of the present invention, it is preferable that an abrasive is supplied onto the polishing sheet when the substrate is polished by being relatively rotated while pressing the polishing surface of the substrate against the polishing sheet.
[0015]
Then, the substrate polishing apparatus of the present invention rotates the platen on which the polishing sheet is attached, rotates the substrate while pressing and pressing the substrate against the polishing sheet from the back surface of the substrate, and polishes the substrate such as glass or semiconductor. In a substrate polishing apparatus for flattening irregularities, a plurality of pressurizing members for pressing a substrate against a polishing sheet from a back surface of a substrate, a pressurizing member holding member for detachably holding the plurality of pressurizing members, and a pressing member holding member A load means for applying an equal pressing force to each of a large number of pressurizing bodies held by the member, and by arranging and spacing the pressurizing bodies according to the polishing surface shape of the substrate, polishing the substrate. The polishing pressure generated between the surface and the polishing sheet can be controlled.
[0016]
In the substrate polishing apparatus of the present invention, it is preferable that the pressing body has a shape that abuts on the back surface of the substrate in a point contact manner, and the pressing body holding member can hold the pressing body detachably. It is preferable that a large number of holes are formed at regular intervals, and the load means further comprises a load and a fluid bag body containing a fluid formed larger than the pressure range of the substrate by the multiple pressure bodies. It is preferable that the pressure body is pressurized through the fluid bag body.
[0017]
In the substrate polishing apparatus of the present invention, it is preferable that a plate-like elastic body is interposed between the pressing body and the substrate.
[0018]
In the substrate polishing apparatus of the present invention, the pressurizing member is arranged in the densest state for the thickest portion according to the thickness shape of the polished surface of the substrate, and the pressure is increased as the film thickness becomes thinner. The substrate can be polished by arranging the pressurizing members so that the spaces between the members are sequentially increased.
[0019]
The substrate polishing apparatus of the present invention preferably further includes a nozzle for supplying a polishing liquid onto the polishing sheet.
[0020]
[Action]
ADVANTAGE OF THE INVENTION According to the board | substrate polishing method of this invention, and a board | substrate grinding | polishing apparatus, a bias | biasing of the pressure in the contact part of each pressurizing body arises by making each pressurizing body contact a board | substrate with a small area of point contact. Therefore, it is only necessary to consider the distribution of the pressing force from the contact point, so that the polishing pressure can be easily controlled, and all the pressurized bodies are pressurized through one fluid bag, and the pressurized body is pressed. A pressing force of the same magnitude can be applied to all of them, and a desired polishing pressure can be obtained by adjusting and controlling the interval and arrangement of the pressing bodies. This eliminates the need for a driving device that presses the individual pressurizing members, and allows a large number of pressurizing members to be arranged without increasing the size and complexity of the device. The shape of the body itself can be reduced, and a finer pressing operation can be performed.
[0021]
Further, by matching the shape of the substrate holder to the substrate shape, it is possible to cope with any substrate shape, and it is easy to cope with an increase in the size of the substrate.
[0022]
Furthermore, a uniform polishing pressure can be obtained over the entire surface of the substrate by a large number of pressurized bodies to which the same pressure is applied, and when there is unevenness in the film thickness of the substrate or unevenness in the amount of polishing after the polishing progresses, the uneven shape is obtained. By adjusting and controlling the interval and arrangement of the pressurizing members so as to remove the pressure, it is possible to obtain a polishing pressure for removing the film thickness unevenness, and it is possible to perform flattening polishing of the substrate.
[0023]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described with reference to the drawings.
[0024]
FIG. 1 is a schematic configuration diagram of an embodiment of a substrate polishing apparatus according to the present invention. This embodiment will be described with reference to FIG.
[0025]
A substrate 1 such as a glass or a semiconductor to be polished is held by a substrate holder 3 disposed in a retainer ring 2 so that a polished surface of the substrate 1 comes into contact with a polishing sheet 4 attached to a surface plate 5. Placed in The polishing sheet 4 is a polyester fiber nonwoven fabric or a foamed polyurethane sheet excellent in chemical resistance, abrasion resistance and elastic recovery force. The platen 5 is driven to rotate by a rotating device (not shown) via a rotating shaft 6. The substrate 1 rotates on the polishing sheet 4 together with the retainer ring 2 and the substrate holder 3 by the rotation of the rotating roller 7. The polishing liquid 8 is supplied onto the polishing sheet 3 through the nozzle 9.
[0026]
A large number of pressurizing members 11 for pressing the polishing surface of the substrate 1 against the polishing sheet 4 are arranged on the back surface side of the substrate 1, and offset the pressure distribution in the contact surface of each pressurizing member 11 with the substrate 1. In order to eliminate the pressure, ideally, a structure that makes point contact with the back surface of the substrate 1 is used. For example, the tip of the pressing body 11 that contacts the back surface of the substrate is shaped like a needle or a sphere, and the pressing body 11 is made of iron or iron. It is made of a material such as nylon. In the embodiment shown in FIG. 1, as one form of the pressing body 11, a columnar pressing body having a spherical end surface in contact with the substrate 1 is used. The pressing body holding member 12 that holds the pressing body 11 is a plate-shaped body made of an acrylic resin or the like, and has a large number of holes 12a having the same shape and the same size as the cross-sectional shape of the pressing body 11, These holes 12a have a structure capable of holding the respective pressurizing members 11 in a detachable manner. In the embodiment shown in FIG. 1, the pressure body holding member 12 is placed on the upper surface of the substrate holder 3 and is arranged so as not to contact the back surface of the substrate 1. The interval between the pressing bodies 11 held by the pressing body holding member 12 is formed small enough to make the polishing pressure generated between the polishing sheet 4 and the substrate 1 uniform, and each pressing body 11 The cross-sectional area of the body 11 is likewise preferably sufficiently small.
[0027]
A fluid bag 13 containing a fluid such as a gas is disposed on the pressurizing body 11, and the fluid bag 13 is formed so as to be larger than a pressurization range of the plurality of pressurizing bodies 11. By applying a load 14 on the fluid bag 13, a pressing force is applied to the pressurizing body 11. As described above, since the pressurizing body 11 is pressurized via the fluid bag 13, the pressing force applied to the substrate 1 by each pressurizing body 11 is not limited even if a load 14 having any shape is used. All equal. In addition, the fluid bag body 13 is uniformly contacted at the peripheral portion and the central portion where the pressurizing member 11 is arranged, and the pressurizing member 11 is formed so that the peripheral portion does not drop so as not to cause a difference in the pressing force. It is necessary to hold it so that it is parallel to the substrate 1 in the range where it is arranged. In the embodiment shown in FIG. 1, a step portion 12 b having the same height as the height of the pressing body 11 protruding from the upper surface of the pressing body holding member 12 is provided on the upper surface of the peripheral portion of the pressing body holding member 12. The peripheral portion of the fluid bag 13 is supported by the step portion 12b so as not to drop.
[0028]
In the first embodiment of the present invention configured as described above, since a large number of pressure members 11 held by the pressure member holding member 12 press the back surface of the substrate 1 in a point contact manner, Since the pressure can be applied without considering the bias of the pressure in the contact surface of each pressurizing body 11 and all the pressurizing bodies 11 are pressurized by the load 14 via one fluid bag 13, A uniform polishing pressure can be obtained over the entire surface. Further, by reducing the interval between the pressing bodies 11 and the shape of the pressing body 11 itself, a finer pressing operation can be performed. As described above, a driving device that presses the individual pressurizing members is not required, and an increase in the size and complexity of the device can be avoided. Further, since each of the plurality of pressurizing bodies 11 is detachably held by the pressurizing body holding member 12, the arrangement and the interval of the pressurizing bodies 11 can be appropriately changed, whereby the thickness of the substrate is reduced. By appropriately arranging the pressing body 11 in accordance with the unevenness of the polishing and the unevenness of the polishing caused by the progress of the polishing, it is possible to obtain a polishing pressure for removing the unevenness of the thickness and the unevenness of the polishing.
[0029]
Next, the removal of unevenness in the thickness and polishing of the substrate will be described in detail with reference to FIG. FIG. 2 is a schematic diagram showing a substrate and a pressing body for pressing the substrate, and is a schematic diagram illustrating an example of an arrangement of the pressing body when unevenness occurs in the amount of polishing after polishing of the substrate. is there.
[0030]
In FIG. 2, reference numeral 1 a denotes a polishing unevenness shape in which the shape of the polishing unevenness is enlarged in the height direction when the polishing amount of the polishing surface is uneven during the polishing of the substrate 1; In the same manner as in the above-described embodiment, a columnar pressing body 11 is used as the pressing body, and holes 12a for holding the pressing body are formed in the pressing body holding member 12 at an equal pitch. The pressing bodies 11 can be arranged at intervals of an integral multiple of the pitch of the holes 12a in accordance with the degree of unevenness or unevenness in polishing.
[0031]
Therefore, the pressurizing members 11 are arranged in the densest state with respect to the portion having the largest thickness according to the shape of the thickness of the polished surface of the substrate and the shape of the unevenness of the polishing. The pressing bodies are arranged so as to be spaced apart from each other, and the polishing can be performed by adjusting the polishing pressure depending on the presence or absence of the pressing body 11.
[0032]
That is, the removal amount per unit time at the interval between the pressurizing bodies 11 can be known in advance by an experiment or the like. For example, the removal amount per unit time when the pressurizing bodies 11 are most densely arranged and polished is obtained. Is 100 nm, the contour line Z is set at a height of 100 nm from the reference plane V of the polished surface of the substrate 1, and when the range of the substrate having an uneven thickness is a, this range The arrangement of the pressurizing body 11 at the portion corresponding to a is made most dense. Similarly, a contour line Y having a height equal to the removal amount per unit time when the pressing body 11 is arranged at an interval of one hole of the pressing body holding member 12 and polished is set, Assuming that a range of the substrate higher than the contour line Y and lower than the contour line Z is b, the arrangement of the pressurizing members 11a in a portion corresponding to the range b is such that the pressurizing members 11 are arranged every other hole 12a of the pressurizing member holding member 12. Place. Similarly, contour lines X, W... Are set at a height equal to the removal amount according to the interval between the pressing bodies 11, and the polishing unevenness is divided into several layers in the height direction. Use to determine the range to place. In this way, the thickness of the polished surface of the substrate is measured, and depending on the thickness, the polishing pressure can be adjusted by the presence or absence of the pressurizing body. Polishing can be performed at an appropriate polishing pressure according to the shape of the polishing amount.
[0033]
In addition, if further polishing unevenness occurs thereafter, the polishing is repeated by adjusting the polishing pressure by arranging the pressing body so as to correspond to the polishing unevenness, and finally a smooth flat surface is formed. Obtainable.
[0034]
As described above, by changing the arrangement and intervals of a large number of pressurized bodies to which the same pressing force is applied, the unevenness of the film thickness is removed according to the unevenness of the thickness of the substrate and the unevenness of the polishing after the progress of polishing. Polishing pressure can be obtained. In addition, a driving device that presses the individual pressurizing members is not required, and an increase in the size and complexity of the device can be avoided.
[0035]
Next, another embodiment of the present invention will be described with reference to FIG. FIG. 3 is a schematic configuration diagram of another embodiment of the substrate polishing apparatus according to the present invention.
[0036]
The present embodiment is different from the above-described embodiment in that a spherical pressing body 11a is used instead of the columnar pressing body in the above-described embodiment, but other configurations are the same. The same members are denoted by the same reference numerals. Also in the present embodiment, the spherical pressing body 11a can press the back surface of the substrate 1 in a point contact manner without taking into consideration the bias of the pressure in the contact surface of each pressing body 11a, Further, since all the pressing bodies 11a are pressed by the load 14 via one fluid bag 13, a uniform polishing pressure can be obtained over the entire surface of the substrate. Further, by reducing the shape of the pressing body 11a itself and the interval between the pressing bodies 11a, a finer pressing operation can be performed, and the same operation and effect as in the above-described embodiment can be obtained.
[0037]
Next, still another embodiment of the present invention will be described with reference to FIG.
[0038]
In the present embodiment, as shown in FIG. 4, a plate-like elastic body 17 is interposed between the substrate 1 and the pressing body 11a, and other configurations are the same as those of the above-described embodiment. , The same members will be described with the same reference numerals.
[0039]
The plate-like elastic body 17 interposed between the substrate 1 and the pressing body 11a has a size equal to or larger than that of the substrate 1, and is made of, for example, silicon or the like. As described above, by interposing the plate-shaped elastic body 17 between the substrate 1 and the pressing body 11a, in addition to the operation and effect of the above-described embodiment, the addition of the contact portion between the substrate 1 and the pressing body 11a is also possible. The concentration of pressure can be dispersed, and a more uniform pressing force can be obtained. In this embodiment, a spherical pressing body 11a is used as the pressing body. However, in the embodiment shown in FIG. It is needless to say that by interposing the pressure, the concentration of the pressing force at the contact portion between the substrate 1 and the pressing body 11 can be dispersed, and a more uniform pressing force can be obtained.
[0040]
【The invention's effect】
As described above, according to the present invention, each pressurized body is brought into point contact with the substrate, thereby preventing the pressure at the contact portion of each pressurized body from being biased, and Since it is only necessary to consider the distribution of the applied pressure, it is easy to control the polishing pressure, and all the pressurized bodies are pressurized through one fluid bag, and the pressurized bodies of the same size are applied to all the pressurized bodies. Pressure can be applied. Further, a desired polishing pressure can be obtained by controlling the interval and arrangement of the pressing members, and a driving device for pressing the individual pressing members is not required. Can be arranged, and the interval between the pressurizing bodies and the shape of the pressurizing body itself can be reduced, so that a finer pressurizing operation can be performed. Further, by matching the shape of the substrate holder to the shape of the substrate, it is possible to cope with any substrate shape, and it is easy to cope with an increase in the size of the substrate.
[0041]
Further, by changing the interval and arrangement of a large number of pressurized bodies given the same pressing force, a uniform polishing pressure or a polishing pressure that removes unevenness in accordance with the uneven shape of the polishing amount after polishing is obtained. be able to.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an embodiment of a substrate polishing apparatus according to the present invention.
FIG. 2 is a schematic view showing a substrate and a pressurizing body for pressing the substrate in the substrate polishing apparatus according to the present invention, and shows an arrangement of the pressurizing body in a case where unevenness occurs in a polishing amount after progress of polishing of the substrate. It is the schematic which illustrates an example of an aspect.
FIG. 3 is a schematic configuration diagram of another embodiment of the substrate polishing apparatus according to the present invention.
FIG. 4 is a schematic configuration diagram of still another embodiment of the substrate polishing apparatus according to the present invention.
FIG. 5 is a schematic configuration diagram of a conventional substrate polishing apparatus using a chemical mechanical polishing method.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 Substrate 1 a Uneven polishing shape 2 Retainer ring 3 Substrate holder 4 Polishing sheet 5 Surface plate 6 Rotating shaft 7 Rotating roller 8 Polishing liquid 9 Nozzle 11 (Columnar) pressurizing body 11 a (Spherical) pressurizing body 12 Pressurizing body holding member 12a hole 13 fluid bag 14 load

Claims

A substrate polishing method for rotating the platen on which the polishing sheet is adhered, rotating and polishing the substrate while pressing and pressing the substrate against the polishing sheet from the back surface, and flattening the irregularities of the substrate such as glass or semiconductor, The substrate is pressed against the polishing sheet by a plurality of pressing bodies pressing the substrate against the polishing sheet from the back surface of the polishing sheet with a force equal to each other and by point contact, and the arrangement of the pressing bodies or the interval between the pressing bodies. A polishing pressure generated between the polishing surface of the substrate and the polishing sheet by controlling the polishing pressure.

The pressurizing body is pressurized through a fluid bag body containing a fluid formed larger than the pressurizing range of the substrate by a large number of pressurizing bodies, and an equal pressing force is applied to all the pressurizing bodies. The substrate polishing method according to claim 1.

3. The substrate polishing method according to claim 1, wherein the plurality of pressurizing members are held by a pressurizing member holding member in which a large number of holes capable of detachably holding the pressurizing members are formed at regular intervals. .

According to the thickness profile of the polished surface of the substrate, the pressing members are arranged in the densest state for the thickest part, and the intervals between the pressing members are sequentially increased as the film thickness decreases. The substrate polishing method according to any one of claims 1 to 3, wherein the substrate is polished by disposing a pressing body so as to perform the polishing.

The substrate polishing method according to any one of claims 1 to 4, wherein an abrasive is supplied onto the polishing sheet when the polishing is performed by relatively rotating the polishing surface of the substrate while pressing the polishing surface against the polishing sheet. .

A substrate polishing apparatus that rotates the platen to which the polishing sheet is attached, rotates the substrate while pressing and pressing the substrate against the polishing sheet from the back surface of the substrate, and polishing and flattening the unevenness of the substrate such as glass or semiconductor. Numerous pressure members for pressing the substrate against the polishing sheet from the back surface of the substrate, a pressure member holding member for detachably holding the multiple pressure members, and a number of pressure members held by the pressure member holding member And a load means for applying an equal pressing force to each of the substrates, and adjusting the arrangement and the interval of the pressurizing members according to the shape of the polishing surface of the substrate and polishing generated between the polishing surface of the substrate and the polishing sheet. A substrate polishing apparatus characterized in that pressure can be controlled.

7. The substrate polishing apparatus according to claim 6, wherein the pressing body has a shape that comes into contact with the back surface of the substrate in a point contact manner.

8. The substrate polishing apparatus according to claim 6, wherein the pressurizing member holding member has a large number of holes formed at regular intervals, each of which can detachably hold the pressurizing member.

The load means includes a fluid bag body containing a fluid formed larger than the pressure range of the substrate by the number of pressure bodies and a load, and pressurizes the pressure body via the fluid bag body. The substrate polishing apparatus according to any one of claims 6 to 8, wherein:

10. The substrate polishing apparatus according to claim 6, wherein a plate-like elastic body is interposed between the pressing body and the substrate.

According to the thickness profile of the polished surface of the substrate, the pressing members are arranged in the densest state for the thickest part, and the intervals between the pressing members are sequentially increased as the film thickness decreases. The substrate polishing apparatus according to any one of claims 6 to 10, wherein the substrate is polished by disposing a pressing body so as to perform the polishing.

The substrate polishing apparatus according to claim 6, further comprising a nozzle for supplying a polishing liquid onto the polishing sheet.