JP3891735B2 - Resist removing agent comprising alkoxy N-hydroxyalkylalkanamide, resist removing composition, production method thereof, and resist removal method using them - Google Patents

Description

上記の化学式１中、Ｍｐは有機金属性ポリマーを示している。
【００１７】
（レジスト除去用組成物の第１実施例）
レジスト除去用組成物の第１実施例は、前述したアルコキシＮ−ヒドロキシアルキルアルカンアミドと、双極子モーメントが３以上の極性物質または損傷防止剤の一方または両方とを含んでいる。
アルコキシＮ−ヒドロキシアルキルアルカンアミドは前述した化学式１で表示される化合物である。
【００１８】
双極子モーメントが３以上の極性物質は、交差結合されたポリマー及びレジストに対し高い溶解性能を示す。即ち、レジストパターンの側壁及び露出した下地膜の表面に強く結合しているポリマーを効率よく除去でき、レジストも容易に除去できる。双極子モーメントが３以上の極性物質としては、水、メタノールまたはジメチルスルホキシドなどを使用することが可能である。
【００１９】
損傷防止剤は、露出している多様な膜、特に金属膜がレジスト除去用組成物によって損傷されるのを防止する。損傷防止剤は下記化学式２で示される。
【００２０】
Ｒ₆−（ＯＨ）_n（化学式２）
化学式２中、Ｒ₆は炭素数１〜５の炭化水素、カルボキシル基が結合されている炭素数１〜５の炭化水素、ベンゼン環を１〜３有する芳香族炭化水素、またはカルボキシル基が結合されているベンゼン環を１〜３有する芳香族炭化水素のいずれかであり、ｎは１〜４の整数である。
特にＲ₆がベンゼン環、ｎが２であるカテコールが損傷防止剤として望ましい。また、従来の技術で広く知られた損傷防止剤である没食子酸も使用可能である。
【００２１】
損傷防止剤が金属膜の損傷を防止するメカニズムをカテコールを例として説明すると、下記の反応式２のようになる。
【００２２】
【化２】

上記の反応式２中でＭは金属を示している。
【００２３】
（レジスト除去用組成物の第１実施例）
レジスト除去用組成物の第２実施例は、アルコキシＮ−ヒドロキシアルキルアルカンアミドとアルカノールアミンとを含む。
アルカノールアミンは化学式３で示される化合物である。
【００２４】
Ｒ₁−ＮＨ−Ｒ₂−ＯＨ（化学式３）
化学式３中、Ｒ₁はＨ原子、炭素数が１〜５の炭化水素、またはベンゼン環を１〜３有する芳香族炭化水素であり、Ｒ₂は炭素数が１〜５の炭化水素、またはベンゼン環を１〜３有する芳香族炭化水素を示している。
特にＲ₁が水素原子、Ｒ₂が−ＣＨ₂−ＣＨ₂−であるものエタノールアミンが本実施例のアルカノールアミンとして望ましい。
【００２５】
アルカノールアミンも有機金属性ポリマーの除去に効果的である。アルカノールアミンのポリマーの除去メカニズムをモノアルカノールアミンを例として示すと下記の反応式３の通りである。
【００２６】
【化３】

上記の反応式３のＭｐは有機金属性ポリマーを示している。
【００２７】
さらに、第２実施例によるレジスト除去用組成物は、双極子モーメントが３以上の極性物質または損傷防止剤の一方または両方を含むことが望ましい。
前述したようなレジスト除去用組成物及び各構成要素の重量％を示したものが下記の表１である。
【００２８】
【表１】

【００２９】
※（）内はより望ましい含有量の範囲を示している。
【００３０】
表１に示した組成物の含量の範囲は、レジスト及びポリマーを効果的に除去でき、レジスト除去剤またはレジスト除去用組成物によって露出している例えば金属膜などの下地膜の損傷が最小限になる範囲を示している。
前述した組成物中、３及び７の組成物がレジスト及びポリマー除去力に最も優れており、レジスト下地膜の金属膜がある場合、金属膜に損傷を起こさないという長所がある。
【００３１】
しかし、損傷防止剤を含まない組成物である１、４、５も、レジスト除去剤またはレジスト除去用組成物によって損傷する金属膜のような部位が露出しない場合は、３及び７と同一の効果を示すことが可能である。また、双極子モーメントが３以上の極性物質を含まない組成物２、４、６は、金属膜の損傷防止をより防止する必要がある場合、除去する必要のあるポリマーの量がわずかである場合、またはポリマー除去のための前処理工程を実施した場合には、３及び７の組成物と同一の効果を示すことが可能である。
【００３２】
前述したように本発明に係るレジスト除去剤またはレジスト除去用組成物はレジスト除去力に優れるだけでなく、蝕刻副産物であるポリマーの除去力に優れる。また、例えば金属膜などの下地膜がレジスト除去剤またはレジスト除去用組成物に対し露出している場合であっても、下地膜は損傷することがない。さらに、レジスト除去剤またはレジスト除去用組成物を構成する物質は、従来のレジスト除去用組成物を構成する物質と比較して安価であるため、製造コストを低減することができる。
【００３３】
（レジスト除去剤の製造方法）
アルコキシＮ−ヒドロキシアルキルアルカンアミドは、下記の反応式４に示すように上記の化学式３で表示されるアルカノールアミンと上記の化学式４で表示されるアルキルアルコキシアルカノエートとを反応させて製造する。
【００３４】
【化４】

反応式４中、Ｒ₁はＨ原子、炭素数が１〜５の炭化水素、またはベンゼン環を１〜３有する芳香族炭化水素であり、Ｒ₂は炭素数が１〜５の炭化水素、またはベンゼン環を１〜３有する芳香族炭化水素であり、Ｒ₃及びＲ₄はそれぞれ炭素数が１〜５の炭化水素を示している。
アルカノールアミンとしてはＲ₁が水素原子でＲ₂が−ＣＨ₂−ＣＨ₂−であるモノエタノールアミン、アルキルアルコキシアルカノエートとしてはＲ₂が−ＣＨ₂−ＣＨ₂−でＲ₅が−ＣＨ₃であるメチルメトキシプロパノエートが望ましい。
反応の際、十分に化学反応が行われるように反応温度は約２５℃（常温）〜１２０℃に維持する。
【００３５】
前記の反応式４に示すように、アミン（III）とエステル（IV）とを反応させることにより、アミド（I）とアルコール（V）とが生成される。
反応式４中のアルコール（V）は炭素数が１〜５のアルコールであり沸点が低い物質（例：メタノールの沸点は約６０℃）であり、アミド（I）は沸点が高い物質（例：メトキシＮ−ヒドロキシエチルプロパンアミドの沸点は約２００℃）である。従って、分別蒸留法によりアルコール（V）を除去し、アミド化合物（I）を収得することができる。
【００３６】
分別蒸留時、反応槽内で窒素バブリング処理して分別蒸留を促進したり、反応槽内の圧力を下げてアルコールの気化を促進することが望ましい。もちろん二つの方法を同時に使用することもできる。
【００３７】
（レジスト除去用組成物の製造方法）
表１に記載されているレジスト除去用組成物は、前述したようにアルコキシＮ−ヒドロキシアルキルアルカンアミドを先に製造した後、損傷防止剤、双極子モーメントが３以上の物質またはアルカノールアミンの一方または両方、アルコキシＮ−ヒドロキシアルキルアルカンアミドを表１の含量割合で混合して調製する。
【００３８】
表１の組成物１〜７は以下のように調製することが可能である。
損傷防止剤（０．０１重量％〜３０重量％）または極性物質（０．０１重量％〜３０重量％）の一方または両方と、アルカノールアミン（１０重量％〜７０重量％：望ましくは３０重量％〜４０重量％）と、アルキルアルコキシアルカノエート（１０重量％〜７０重量％：望ましくは３０重量％〜４０重量％）とを混合する。混合の際、アルキルアルコキシアルカノエートの全量がアルカノールアミンと完全に反応し、完全にアミドが生成されるような含量の割合となるように、アルカノールアミンとアルキルアルコキシアルカノエートとを混合することが望ましい。混合物の温度は、約２５℃〜１２０℃に維持する。望ましくは８０℃〜９０℃に加熱する。反応時間は１時間〜２４時間、望ましくは１時間〜１２時間とする。加熱が完了した後、混合物を１時間〜７時間程度放置し、冷却する。
【００３９】
反応の終了を確認する方法としては、肉眼で確認する方法、またはガスクロマトグラフィーを使用する方法がある。前者の方法は、構成要素間の層分離が無くなったかどうかを観察し、構成要素が完全に混合された状態を反応の終了と推定する。後者の方法は組成物をガスクロマトグラフィーで分析し、アルコキシＮ−ヒドロキシアルキルアルカンアミドの面積の割合が８０％以上になれば反応が終了したとみなすことができる。面積割合は、ガスクロマトグラフィースペクトルに示された全ての構成要素のピーク面積の和を１００とし、ピークの総面積に対する該当構成要素のピーク面積を％で示した値である。
【００４０】
次いで、反応副産物として生成される沸点の低いアルコールを除去するために分別蒸留を実施する。分別蒸留は先に説明したように反応槽内で窒素バブリング処理して分別蒸留を促進したり、反応槽内の圧力を下げてアルコールの気化を促進したり、両方法を混合して進行する。望ましくは調製した組成物に対してアルコールの残量が７重量％〜８重量％以下になるように分別蒸留を行う。
【００４１】
（レジスト除去方法）
レジスト除去剤及びレジスト除去用組成物を使用してレジストを除去する方法を図１に基づいて説明する。
半導体素子を完成するための多様な工程、例えば蝕刻（乾式または湿式）工程、イオン注入工程などをレジストパターンをマスクとして使用することにより実施する。次いで、基板からレジストパターンを取り除く（段階１１０）。レジストパターンの除去段階は、Ｏ₂プラズマ処理方式の乾式ストリップ方法あるいは硫酸溶液のような溶液を使用した湿式ストリップ方法を用いる。
【００４２】
次に、レジストパターンが形成されている基板とレジスト除去剤またはレジスト除去用組成物とを接触させ、レジスト及びポリマーを除去する（段階１２０）。基板とレジスト除去剤またはレジスト除去用組成物とを接触させる方法としては、レジスト除去剤またはレジスト除去用組成物をバスに入れた後、バス中に基板を浸漬することによりレジスト除去剤またはレジスト除去組成物と接触させたり、レジスト除去剤またはレジスト除去用組成物を基板上にスプレーすることにより接触させる。
【００４３】
レジスト除去剤またはレジスト除去用組成物を使用する場合、レジスト除去段階は７０℃以下の低温で実施することが可能である。特に、約２５℃〜７０℃、望ましくは４５℃〜７０℃で実施する。そして、接触時間は１０分〜３０分である。
レジスト除去剤またはレジスト除去用組成物により除去されるレジストは、既存のｉ−ライン（３６５ｎｍ）用レジスト及びＫｒＦエクサイマーレーザ（２４８ｎｍ）用レジストだけでなく、ＡｒＦエクサイマーレーザ（１９３ｎｍ）用レジストのような短波長露光源用レジストにも適用できる。
【００４４】
レジスト除去が完了すると、基板表面に残留するレジスト除去剤またはレジスト除去用組成物及び溶解されたレジストを水洗する段階を実施する（段階１４０）。水洗は脱イオン水を用いて実施し、必要に応じて２段階に分けて実施する場合もある。最後に基板をスピンドライ法またはイソプロピルアルコールを使用するドライ法で乾燥して基板表面に残っている脱イオン水を除去する（段階１５０）。
【００４５】
乾燥段階まで終了した基板は次の工程に移送される。後続工程で再びレジストを使用する場合には、目的とする工程が完了された後、再び図１の工程を経て使用したレジストを除去する。このように反復的な単位工程とレジスト除去工程を経て半導体素子を完成する。
【００４６】
図１に示すように、本発明のレジスト除去剤またはレジスト除去用組成物は、レジスト除去力だけでなくポリマー除去力に優れるので、点線で示す従来のレジスト除去前処理段階（段階１００）が不要である。また、レジスト下地膜に対する損傷が防止されるので点線で示すレジスト除去後処理段階（段階１３０）も省略できる。従って、従来の除去工程に比べて非常に単純化した工程でレジストを完全に除去でき、半導体素子の生産性を顕著に向上させることができる。
【００４７】
（レジスト除去装置）
前述したようにレジスト除去のための工程を単純化することができるので、レジスト除去剤またはレジスト除去用組成物を使用するレジスト除去装置も小型化することができる。
【００４８】
図２に示すようにレジスト除去装置２００は、レジスト除去ユニット２１０、水洗ユニット２２０及び乾燥ユニット２３０のみを有している。従って、従来のレジスト除去装置で必要であった前処理ユニット及び後処理ユニットが不要である。即ち、レジスト除去装置２００が必要とする体積を従来と比較して大幅に縮小することができる。
【００４９】
レジスト除去装置２００が浸漬方式を利用する場合、レジスト除去ユニット２１０、水洗ユニット２２０、及び乾燥ユニット２３０はそれぞれ１つのバスから構成される。そのため、従来の硝酸処理バス及びイソプロピルアルコール処理バスが不要である。従って、レジスト除去装置２００が必要とする体積を従来と比較して大幅に縮小することができる。
スプレー方式のレジスト除去装置としては、水平型装置及び垂直型装置を適用することができる。
【００５０】
図３に示すように、水平型装置は水平に運送する例えばコンベヤシステム、ハンドラまたはアームをなどのキャリア３４０、レジスト除去ユニット３１０、水洗ユニット３２０及び乾燥ユニット３３０より構成されている。レジスト除去剤またはレジスト除去用組成物が蓄えられているソース３６０は、供給ユニット３７０を通じてレジスト除去剤またはレジスト除去用組成物をレジスト除去ユニット３１０に供給する。水洗剤ソース３６２及び乾燥剤ソース３６４もそれぞれ供給ユニット３７０を通じて水洗ユニット３２０及び乾燥ユニット３３０に連結されている。各ユニットごとに該ユニットの機能に適した物質をスプレーするノズル３１２、３２２、３３２が設けられている。
【００５１】
まずレジストが形成された基板がレジスト除去ユニット３１０にローディングされると、ノズル３１２からレジスト除去剤またはレジスト除去用組成物がスプレーされてレジストが除去される。この際、基板はキャリア３４０により水平方向に継続的に移動され水洗ユニット３２０に移動する。水洗ユニット３２０ではノズル３２２を通して水洗剤がスプレーされる。最後に基板はキャリア３４０を通じて乾燥ユニット３３０に移動して乾燥工程が実施される。水平型装置も３つのユニットだけより構成されるので、装置が必要とする体積を大幅に縮小することができる。
【００５２】
図４に示すように垂直型装置４００は、上下に移動可能な基板支持台４４０を使用している。垂直型装置４００も、レジスト除去剤またはレジスト除去用組成物のソース４６０と、レジスト除去剤またはレジスト除去用組成物を供給する供給ユニット４７０とを有している。望ましくは、基板支持台４４０は回転運動可能な構造に形成されている。そして装置の内部は独立的なユニットというよりは、３つの領域、即ち乾燥領域４３０、水洗領域４２０及びレジスト除去領域４１０が順番に積層されている層状構造よりなる。水洗剤ソース４６２及び乾燥剤ソース４６４も各々の供給ユニット４７０を通じて供給管４５０に連結されている。本実施例に示されている供給管４５０は３つの相異なるソースを順番に供給する。
【００５３】
まずレジストが形成されている図示しない基板が基板支持台４４０にローディングされた後、レジスト除去領域４１０に移動する。基板がレジスト除去領域４１０に移動すると、レジスト除去剤またはレジスト除去用組成物のソース４６０内のレジスト除去剤またはレジスト除去用組成物が供給ユニット４７０に供給され、供給管４５０を通して基板にスプレーされる。この際、基板支持台４４０の回転運動によりレジスト除去剤またはレジスト除去用組成物は基板の外の図示しない排出部に排出されることが望ましい。レジスト除去工程が完了すると、基板支持台440の下降移動により水洗領域４２０に基板が移動する。供給管４５０を通して水洗剤が基板に供給されて水洗工程を実施する。最後に基板支持台４４０の移動により乾燥領域４３０に基板が移動し、乾燥工程を実施する。
【００５４】
図４では乾燥領域４３０、水洗領域４２０及びレジスト除去領域４１０の順に積層された構造を示したが、その順序を逆にすることも可能である。この垂直型装置４００も３つの領域だけを必要とするので装置を小型、軽量化できる。
【００５５】
次に、本発明を適用した実験例について説明する。ただし、この実験例が本発明を限定するものではない。
（実験例１：メトキシＮヒドロキシエチルプロパンアミドの製造）
アルカノールアミンとしてのモノエタノールアミン（以下、「ＭＥＡ」）２００ｍｌと、エステルとしてのメチルメトキシプロパノエート（以下、「ＭＭＰ」）２００ｍｌとを混合した。次いで混合物を９０℃で５時間加熱し、加熱後５時間約２５℃に放置した。
【００５６】
得られた結果物をガスクロマトグラフィーで精製し、目的物を収得した。
前記目的物のＮＭＲデータは以下のようである。¹Ｈ−ＮＭＲ：６．８ｐｐｍ（１Ｈ）、３．７〜３．８ｐｐｍ（４Ｈ）、３．４〜３．５ｐｐｍ（３Ｈ）、２．８〜２．９ｐｐｍ（１Ｈ）
【００５７】
（実験例２：メトキシＮブチルヒドロキシエチルプロパンアミドの製造）Ｎ、Ｎｔ−ブチルエタノールアミン２００ｍｌと、ＭＭＰ２００ｍｌとを混合した。次いで混合物を９０℃で５時間加熱し、加熱後５時間約２５℃で放置した。
得られた結果物をガスクロマトグラフィーで精製し、目的物を収得した。
【００５８】
（実験例３：メトキシＮヒドロキシエチルプロパンアミド製造の適正温度の評価）
アルカノールアミンとしてのＭＥＡ２００ｍｌと、エステルとしてのＭＭＰ２００ｍｌとを混合した。次いでアミンとエステルの反応に適合した温度を調べるために、下記表２のように反応温度を変化させてメトキシＮヒドロキシエチルプロパンアミドを合成し、合成に要する時間を測定した。合成の終了は、ガスクロマトグラフィーで成分を分析し、アミドの面積割合が８０％以上となる点と設定した。
【００５９】
【表２】

【００６０】
表２の結果から約２５℃でも反応が可能なことが分かり、高温になるほど反応が迅速に起こることが分かった。しかし、製造工程上の他条件などを考える時、反応温度は１２０℃を越えないほうが望ましい。従って本発明に係るアミド化合物の製造温度は約２５℃〜１２０℃が望ましく、より望ましくは８０℃〜９０℃となる。
【００６１】
（実験例４：レジスト除去用組成物の製造及びこれを用いたレジスト除去力の評価）
下記の表３のように、モノエタノールアミン、メチルメトキシプロパノエート、カテコール及び水の含量を変化させて７種類の相異なる組成物を製造した。次いで、組成物を８０℃で５時間加熱した。次に、加熱後の組成物を６時間約２５℃で放置した後、窒素バブリング法と減圧法を並行した分別蒸留法でメタノールを除去して組成物を完成した。
【００６２】
一方、前述したレジスト除去用組成物で除去するレジストは次のように調製した。まず基板上にＢＰＳＧ膜を５０００Åの厚さに形成した。次いで、チタン膜及びチタン窒化膜をそれぞれ２００Åの厚さに形成した後、アニーリングした。次に、アルミニウム膜を６０００Åの厚さに蒸着した後、フローさせた。キャッピング層としてチタン窒化膜をアルミニウム膜上に形成した後、層間絶縁膜を１００００Åの厚さに形成した。次に、レジストを層間絶縁膜上に塗布した後、写真工程を実施してビアホールを限るレジストパターンを形成した。レジストパターンをべークした後、これをマスクとして使用して緩衝酸化膜蝕刻液で層間絶縁膜を蝕刻してビアホールを形成した。ビアホールを完成した後、基板に対してアシング工程を実施し、それぞれ異なる組成の組成物が入ったバスに浸漬した。バスの温度は６０℃に維持した。２０分間浸した後、水で５分間洗浄し乾燥した後、走査電子顕微鏡で基板を観察した。観察結果に従って基板を良好、中上及び最上に等級化し、この等級は表３にシンボルで示した。
【００６３】
【表３】

【００６４】
観察結果のシンボルは、○が良好（good）、◎が中上（better）、●が最上（best）の状態を示している。
【００６５】
観察結果は残留するポリマー及びレジストの相対的な量により分類した。良好な状態○は従来のレジスト除去用組成物であるＥＫＣ−２４５を使用した場合の結果と類似した状態、中上の状態◎は従来の結果より改善された状態、最上の状態●は従来より顕著に改善された状態を示す。ＥＫＣ−２４５はヒドロキシルアミン、ジグリコールアミン、カテコール及び水を主要構成要素とする従来のレジスト除去用組成物である。
【００６６】
（実験例５：組成成分の分析）
表３に示す比率で各構成要素を混合した後、所定時間の経過後に各組成物の成分を分析した。その結果、各組成物は下記の表４ような構成成分よりなっていることが分かった。
【００６７】
【表４】

【００６８】
（実験例６：適正処理時間の評価）
処理時間の適正値を調べるために、表４に示した４番の組成物を用いて処理時間を下記表５のように変化させてレジストを除去した。その他の工程条件は実験例４と同一にした。レジスト除去状態とアルミニウム膜及びシリコン膜の損傷の有無を走査電子顕微鏡で観察した。
【００６９】
【表５】

【００７０】
上記の表５のレジスト除去力、損傷有無において示したシンボルは、◎が中上、●が最上の状態を示し、×は下地膜がいかなる損傷も受けなかったことを示している。
表５の結果から、本発明に係るレジスト除去用組成物の処理時間の最適値は１０分〜３０分間であることが分かった。また、下地膜の損傷を完全に防止することができた。
【００７１】
（実験例７：適正温度の評価）
適正処理温度を調べるために、表４の４番に示した組成物を使用して処理時間を下記の表６のように変化させてレジストを除去した。その他の工程条件は実験例４と同一にした。レジスト除去状態とアルミニウム膜及びシリコン膜の損傷の有無を走査電子顕微鏡で観察した。
【００７２】
【表６】

【００７３】
表６の結果から、４５℃〜７０℃の低温でもレジスト除去が円滑に行われることが分かる。
【００７４】
（実験例８：レジスト除去力の比較）
レジストパターンを用いたビアホールの形成は実験例４と同一、組成物として表４の４番の組成物を使用、処理時間を２０分、反応温度を６０℃としてレジストを除去した。レジストを除去した後、走査電子顕微鏡で観察した。その結果を図５に示した。
図６は比較例を示しており、レジスト除去用組成物としてＥＫＣ−２４５を使用した以外は、上記と同一である。
【００７５】
図５及び図６の走査電子顕微鏡写真を比較してみると、本発明のレジスト除去用組成物を使用する場合、レジストが完全に除去されている。これに対し、従来のレジスト除去用組成物であるＥＫＣ−２４５を使用する場合、レジストが一部残存することが分かった。また、本発明のレジスト除去用組成物を使用した場合、アルミニウム膜の損傷は発生しなかった。これに対し、ＥＫＣ−２４５を使用した場合、アルミニウム膜が一部損傷されることが分かった。
【００７６】
（銅膜の損傷の有無の測定）
次世代の配線物質として有力な銅配線に対する影響を調べるため、次のように実験を実施した。図７に示すように、基板１１００上にＢＰＳＧ膜を５０００Åの厚さで形成した後、写真蝕刻工程で基板上のＢＰＳＧ膜をパタニングして複数のコンタクトホールを形成した。次いで、コンタクトホールの表面に障壁金属膜でチタニウム/チタニウム窒化膜１３００、１３５０をそれぞれ２００Åの厚さで順次に形成した後、各コンタクトホールを埋立てる銅膜１４００を１００００Åの厚さで形成した。
【００７７】
次いで、調製した基板をＡ、Ｂ、Ｃの３つのグループに分類した。Ａグループはレジスト除去用組成物を使用しないグループ、Ｂグループは表４の４番に示すレジスト除去用組成物を使用し６５℃で１００分間浸漬したグループ、Ｃグループは従来のレジスト除去用組成物であるＥＫＣ−２４５を使用し６５℃で１００分間浸漬したグループである。
【００７８】
そして、Ａグループ、Ｂグループ、Ｃグループをそれぞれ走査電子顕微鏡で観察した。その結果を図７〜図９に示しており、図７はＡグループ、図８はＢグループ、図９はＣグループを示している。図８に示すように表４の４番に示す本発明のレジスト除去用組成物を使用したＢグループの場合、図７に示すようなレジスト除去用組成物を使用しないＡグループと同一の結果となった。即ち、本発明のレジスト除去用組成物が銅膜をまったく損傷させなかったことを示している。これに対し、従来のＥＫＣ−２４５をしたＣグループの場合、図９に示すように銅膜が激しく損傷し、ほとんど残存していなかった。
【００７９】
図７〜図９に示した結果から銅膜の蝕刻率を計算すると、表７のようになる。
【００８０】
【表７】

【００８１】
さらに、本発明のレジスト除去用組成物が銅膜の表面に及ぼす影響を調べるために、Ａグループの銅膜と、Ｂグループの銅膜表面とをオージェ電子分光器で分析した。その結果を図１０及び図１１にそれぞれ示した。
図１０及び図１１のオージェ電子分光スペクトルがほとんど同一であることから考察すると、本発明のレジスト除去用組成物が銅膜に何の影響も及ぼさないことが分かった。
【００８２】
（実験例１０：レジスト除去用組成物の構成成分の変化測定）
表３の４番に示す組成物に対し８時間毎にレジスト組成物の構成成分の含有量をガスクロマトグラフィーで分析した。分析した結果を図１２に示している。
■はアミドの面積割合（％）、△はモノエタノールアミンの面積割合（％）、×はメチルメトキシプロパノエートの面積割合（％）をそれぞれ示している。
【００８３】
図１２に示すように、４８時間が経過した後であっても、アミドの面積割合（％）は８０％で安定していることが分かる。モノエタノールアミンの面積割合（％）も３．４でほぼ一定である。メチルメトキシプロパノエートの面積割合（％）は２４時間が経過すると、０．９から０．５に減少し、４０時間以後は０となった。
【００８４】
以上より、反応が終了し安定化した本発明の組成物内にはアミド、アミン、カテコール及び水が含まれていることが分かる。そして、本組成物の主要活性成分がアミドであることを考えると、アミドの含量が４８時間が過ぎても変化しなかったことは、本発明の組成物が容易に揮発せず、長時間使用可能であることを示している。従来のレジスト除去用組成物であるＥＫＣ−２４５は２４時間毎に交換する必要があることと比較すると、生産性及び製造コストを大幅に縮小可能であることを示している。
【００８５】
【発明の効果】
本発明のレジスト除去剤またはレジスト除去用組成物はレジスト除去力に優れるだけでなく、ポリマー及び有機金属性ポリマーを効率よく除去できる。また、露出している下地膜が本発明のレジスト除去剤またはレジスト除去用組成物によって損傷されることがない。従って本発明のレジスト除去剤またはレジスト除去用組成物を使用する場合、ポリマーを除去するためのレジスト除去前処理段階及び下地膜の損傷を防止するための後処理段階が不要である。従って、レジスト除去工程を単純化し処理時間を短縮できる。またレジスト除去時の温度を低温に設定できる。そして、レジスト除去装置も単純化して軽量化できる。
【図面の簡単な説明】
【図１】本発明のレジスト除去方法を示すフロー図である。
【図２】本発明のレジスト除去剤またはレジスト除去用組成物を使用してレジストを除去するレジスト除去装置を示すブロック図である。
【図３】本発明のレジスト除去剤またはレジスト除去用組成物を使用してレジストを除去する水平型レジスト除去装置を示す概略図である。
【図４】本発明のレジスト除去剤またはレジスト除去用組成物を使用してレジストを除去する垂直型レジスト除去装置を示す概略図である。
【図５】本発明のレジスト除去用組成物を使用してレジストを除去した状態を示す図である。
【図６】従来のレジスト除去用組成物を使用してレジストを除去した状態を示す図である。
【図７】銅膜が形成されている基板に対しレジスト除去用組成物を適用する前の状態を示す断面図である。
【図８】銅膜が形成されている基板に対し本発明のレジスト除去用組成物を適用した後の状態を示す断面図である。
【図９】銅膜が形成されている基板に対し従来のレジスト除去用組成物を適用した後の状態を示す断面図である。
【図１０】銅膜が形成されている基板に対しレジスト除去用組成物を適用する前にオージェ電子分光器で銅膜の表面を観察したグラフを示す図である。
【図１１】銅膜が形成されている基板に対し本発明のレジスト除去用組成物を適用した後にオージェ電子分光器で銅膜の表面を観察したグラフを示す図である。
【図１２】レジスト組成物の構成要素の含有量の変化を示す図である。
【符号の説明】
３１０ レジスト除去ユニット
３１２、３２２、３３２ ノズル
３２０ 水洗ユニット
３３０ 乾燥ユニット
３４０ キャリア
３６０ ソース
３６２ 水洗剤ソース
３６４ 乾燥剤ソース
３７０ 供給ユニット[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a resist remover, a resist removing composition, a production method thereof, and a resist removal method using the same. In particular, the present invention relates to a resist remover or a resist removal composition comprising an alkoxy N-hydroxyalkylalkanamide, a production method thereof, and a resist removal method using the same.
[0002]
[Prior art]
The removal of the resist is a very important process for manufacturing a semiconductor device. After performing various processes for manufacturing a semiconductor device, such as an etching process (dry or wet) or an ion implantation process, the resist pattern used as a mask must be removed. Even when the resist pattern is misaligned, it is necessary to remove it in order to form a new resist pattern. In particular, there are various different material films (eg, oxide film, aluminum film, copper film, polysilicon film, silicide film, or polyimide film) below the resist film to be removed. Therefore, the main issue of the resist removal process is to completely remove the resist from the surface of the substrate as quickly as possible without damaging the underlying film.
[0003]
Currently used resist removers contain as basic components a basic amine such as hydroxylamine, diglycolamine, monoethanolamine or methylethanolamine and a polar solvent such as water or alcohol.
[0004]
However, the conventional resist remover cannot completely remove the polymer, and thus further requires a pretreatment step for removing the polymer. When the plasma or reactive ion etching is performed to etch the underlying film using the resist pattern as a mask, the polymer is generated by the reaction of components such as carbon, hydrogen, and oxygen that compose the resist pattern with the plasma. It is a substance. In particular, when a metal film is formed under the resist pattern, an organometallic polymer is formed. When such a polymer and organometallic polymer are difficult to remove and remain in a contact hole or via hole, the contact resistance increases. Therefore, before using the resist remover, it is necessary to treat with a water wash enhancer, such as a nitric acid solution, to remove the polymer as a pretreatment step.
[0005]
Conventional resist removers have the disadvantage of damaging the underlying film. A typical example of the underlying film that is damaged is a metal film. The reason is that the resist remover is mainly composed of a basic solvent or water and easily corrodes the metal film. Therefore, after treating the resist remover, a post-treatment step to prevent damage should be further performed before the water washing step. The post-treatment step is performed using isopropyl alcohol or the like.
[0006]
As mentioned above, it is necessary to perform nitric acid treatment as a pre-treatment stage for resist removal and isopropyl alcohol treatment as a post-treatment stage, so that the resist removal process becomes complicated, and the process time becomes long and the productivity is reduced. Acts as In addition to the resist remover, a pre-treatment substance and a post-treatment substance are required, which increases production costs. In addition, since each bus for performing pre-processing and post-processing is required, the volume of the resist removing apparatus becomes unnecessarily large.
[0007]
[Problems to be solved by the invention]
The technical problem to be achieved by the present invention is to provide a resist remover that not only excels in resist and polymer removal power, but also does not damage the underlying film exposed to the remover.
Yet another technical problem to be achieved by the present invention is to provide a resist removing composition that is excellent in resist and polymer removal power and does not damage the underlying film exposed to the remover.
[0008]
Yet another technical problem to be achieved by the present invention is to provide a method for producing the resist removing composition.
Still another technical problem to be achieved by the present invention is to provide a method for removing a resist using the resist remover or the resist removing composition.
[0009]
[Means for Solving the Problems]
According to the resist remover of any one of claims 1 to 3 of the present invention, the resist remover comprises an alkoxy N-hydroxyalkylalkanamide.
According to the resist removal composition according to any one of claims 4 to 9 of the present invention, it contains one or both of an alkoxy N-hydroxyalkylalkanamide and a polar substance having a dipole moment of 3 or more, or a damage preventing agent. It is out.
[0010]
According to the resist removal composition of any one of claims 10 to 19 of the present invention, the composition contains an alkoxy N-hydroxyalkylalkanamide and an alkanolamine. It is desirable that the composition contains, for example, one or both of a polar substance having a dipole moment of 3 or more and a damage preventing agent.
According to the method for producing a resist removing composition according to any one of claims 20 to 26 of the present invention, an alkanolamine and an alkylalkoxyalkanoate are mixed. The mixture is then reacted.
[0011]
According to the resist removal method according to any one of claims 27 to 37, first, a substrate on which a resist is formed is prepared, and then the substrate is brought into contact with a resist remover or a resist removal composition to remove the resist film from the substrate. Remove.
The resist remover or the resist removing composition according to the present invention is not only excellent in resist removing power but also can efficiently remove a polymer and an organometallic polymer. Further, the base film exposed to the removing agent or the composition is not damaged.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. It should be noted that the present invention is not limited to the embodiments shown below, and can be embodied in various different forms. The present embodiments merely complete the disclosure of the present invention, and completely cover the scope of the invention to those having ordinary knowledge. Is to be provided to inform.
[0013]
(Resist remover)
The resist remover is a resist remover made of alkoxy N-hydroxyalkylalkanamide. The alkoxy N-hydroxyalkylalkanamide is represented by Formula 1.
[0014]
R _Four -O-R _Three -CO-N-R ₁ R ₂ OH (Chemical Formula 1)
In chemical formula 1, R ₁ Is an H atom, a hydrocarbon having 1 to 5 carbon atoms, or an aromatic hydrocarbon having 1 to 3 benzene rings, and R ₂ Is a hydrocarbon having 1 to 5 carbon atoms or an aromatic hydrocarbon having 1 to 3 benzene rings, and R _Three And R _Four Each represents a hydrocarbon having 1 to 5 carbon atoms.
The most desirable resist remover is R ₁ Is an H atom and R ₂ Is -CH ₂ -CH ₂ -And R _Three Is -CH ₂ -CH ₂ -And R _Four Is -CH _Three It is.
[0015]
The resist remover comprising an alkoxy N-hydroxyalkylalkanamide according to the present invention contains a hydroxyl group, an alkoxy group and a carbonyl group. Therefore, the resist remover according to the present invention is very effective for removing and dissolving the resist and polymer.
Moreover, it reacts with the organometallic polymer as shown in Reaction Formula 1, and the organometallic polymer and the like are easily removed from the substrate surface.
[0016]
[Chemical 1]

In the above chemical formula 1, Mp represents an organometallic polymer.
[0017]
(First Example of Composition for Removing Resist)
The first embodiment of the resist removal composition includes the above-described alkoxy N-hydroxyalkylalkanamide and one or both of a polar substance having a dipole moment of 3 or more and a damage preventing agent.
Alkoxy N-hydroxyalkylalkanamide is a compound represented by Chemical Formula 1 described above.
[0018]
Polar materials having a dipole moment of 3 or more exhibit high dissolution performance for cross-linked polymers and resists. That is, the polymer strongly bonded to the sidewall of the resist pattern and the exposed surface of the underlying film can be efficiently removed, and the resist can be easily removed. As a polar substance having a dipole moment of 3 or more, water, methanol, dimethyl sulfoxide, or the like can be used.
[0019]
The damage prevention agent prevents various exposed films, particularly metal films, from being damaged by the resist removing composition. The damage inhibitor is represented by the following chemical formula 2.
[0020]
R ₆ -(OH) _n (Chemical formula 2)
In chemical formula 2, R ₆ 1 represents a hydrocarbon having 1 to 5 carbon atoms, a hydrocarbon having 1 to 5 carbon atoms to which a carboxyl group is bonded, an aromatic hydrocarbon having 1 to 3 benzene rings, or a benzene ring to which a carboxyl group is bonded. Or any one of aromatic hydrocarbons, and n is an integer of 1 to 4.
Especially R ₆ Is a benzene ring and n is 2 as a damage inhibitor. Moreover, gallic acid which is a damage preventing agent widely known in the prior art can also be used.
[0021]
The mechanism by which the damage preventive agent prevents damage to the metal film will be described by the following reaction formula 2 using catechol as an example.
[0022]
[Chemical 2]

In the above reaction formula 2, M represents a metal.
[0023]
(First Example of Composition for Removing Resist)
A second embodiment of the resist removal composition includes an alkoxy N-hydroxyalkylalkanamide and an alkanolamine.
Alkanolamine is a compound represented by Formula 3.
[0024]
R ₁ -NH-R ₂ —OH (Formula 3)
In chemical formula 3, R ₁ Is an H atom, a hydrocarbon having 1 to 5 carbon atoms, or an aromatic hydrocarbon having 1 to 3 benzene rings, and R ₂ Represents an hydrocarbon having 1 to 5 carbon atoms or an aromatic hydrocarbon having 1 to 3 benzene rings.
Especially R ₁ Is a hydrogen atom, R ₂ Is -CH ₂ -CH ₂ -Ethanolamine is desirable as the alkanolamine of this example.
[0025]
Alkanolamines are also effective in removing organometallic polymers. The removal mechanism of the alkanolamine polymer is represented by the following reaction formula 3 using a monoalkanolamine as an example.
[0026]
[Chemical 3]

Mp in the above reaction formula 3 represents an organometallic polymer.
[0027]
Furthermore, the resist removing composition according to the second embodiment preferably includes one or both of a polar substance having a dipole moment of 3 or more and a damage preventing agent.
Table 1 below shows the resist removal composition as described above and the weight percent of each component.
[0028]
[Table 1]

[0029]
* () Indicates a more desirable range of content.
[0030]
The range of the content of the composition shown in Table 1 can effectively remove the resist and the polymer, and the damage to the underlying film such as a metal film exposed by the resist remover or the resist removing composition is minimized. Shows the range.
Among the above-mentioned compositions, the compositions 3 and 7 are most excellent in resist and polymer removing power, and there is an advantage that the metal film is not damaged when there is a metal film as a resist underlayer.
[0031]
However, the compositions 1, 4 and 5 which are compositions containing no damage preventing agent also have the same effect as 3 and 7 when a portion such as a metal film damaged by the resist remover or the resist removing composition is not exposed. Can be shown. In addition, in the case of compositions 2, 4, and 6 that do not contain a polar substance having a dipole moment of 3 or more, it is necessary to further prevent damage to the metal film, and the amount of polymer that needs to be removed is small. Alternatively, when the pretreatment step for polymer removal is performed, it is possible to show the same effect as the compositions of 3 and 7.
[0032]
As described above, the resist remover or the resist removing composition according to the present invention is excellent not only in resist removing ability but also in removing ability of a polymer as an etching byproduct. Further, even if the base film such as a metal film is exposed to the resist remover or the resist removing composition, the base film is not damaged. Further, since the substance constituting the resist remover or the resist removing composition is less expensive than the substance constituting the conventional resist removing composition, the manufacturing cost can be reduced.
[0033]
(Method for producing resist remover)
The alkoxy N-hydroxyalkylalkanamide is produced by reacting the alkanolamine represented by the above chemical formula 3 with the alkylalkoxyalkanoate represented by the above chemical formula 4 as shown in the following reaction formula 4.
[0034]
[Formula 4]

In Reaction Scheme 4, R ₁ Is an H atom, a hydrocarbon having 1 to 5 carbon atoms, or an aromatic hydrocarbon having 1 to 3 benzene rings, and R ₂ Is a hydrocarbon having 1 to 5 carbon atoms or an aromatic hydrocarbon having 1 to 3 benzene rings, and R _Three And R _Four Each represents a hydrocarbon having 1 to 5 carbon atoms.
R as alkanolamine ₁ Is a hydrogen atom and R ₂ Is -CH ₂ -CH ₂ As monoethanolamine, alkylalkoxyalkanoate as R ₂ Is -CH ₂ -CH ₂ -With R _Five Is -CH _Three The methyl methoxypropanoate is preferred.
During the reaction, the reaction temperature is maintained at about 25 ° C. (normal temperature) to 120 ° C. so that a chemical reaction is sufficiently performed.
[0035]
As shown in the above reaction formula 4, amide (I) and alcohol (V) are produced by reacting amine (III) with ester (IV).
The alcohol (V) in the reaction formula 4 is a substance having 1 to 5 carbon atoms and a low boiling point (eg, the boiling point of methanol is about 60 ° C.), and the amide (I) is a substance having a high boiling point (eg: The boiling point of methoxy N-hydroxyethylpropanamide is about 200 ° C.). Accordingly, alcohol (V) can be removed by fractional distillation to obtain amide compound (I).
[0036]
During fractional distillation, it is desirable to promote fractional distillation by nitrogen bubbling in the reaction vessel, or to promote the vaporization of alcohol by lowering the pressure in the reaction vessel. Of course, the two methods can be used simultaneously.
[0037]
(Method for producing resist removal composition)
As described above, the resist removal composition described in Table 1 is prepared by first producing an alkoxy N-hydroxyalkylalkanamide as described above, and then applying one of a damage inhibitor, a substance having a dipole moment of 3 or more, or an alkanolamine. Both are prepared by mixing alkoxy N-hydroxyalkylalkanamides in the proportions shown in Table 1.
[0038]
Compositions 1-7 in Table 1 can be prepared as follows.
One or both of a damage inhibitor (0.01 wt% to 30 wt%) or a polar substance (0.01 wt% to 30 wt%) and an alkanolamine (10 wt% to 70 wt%: desirably 30 wt%) ˜40 wt%) and an alkylalkoxyalkanoate (10 wt% to 70 wt%: desirably 30 wt% to 40 wt%). When mixing, it is desirable to mix the alkanolamine and the alkylalkoxyalkanoate so that the total amount of the alkylalkoxyalkanoate reacts completely with the alkanolamine to give a complete amide. . The temperature of the mixture is maintained at about 25 ° C to 120 ° C. Desirably, heating is performed at 80 ° C to 90 ° C. The reaction time is 1 to 24 hours, preferably 1 to 12 hours. After the heating is completed, the mixture is left for about 1 to 7 hours and cooled.
[0039]
As a method for confirming the completion of the reaction, there are a method for confirming with the naked eye and a method using gas chromatography. The former method observes whether or not the layer separation between the components has been lost, and estimates that the reaction is completed when the components are completely mixed. In the latter method, the composition is analyzed by gas chromatography, and when the area ratio of alkoxy N-hydroxyalkylalkanamide is 80% or more, the reaction can be regarded as completed. The area ratio is a value in which the sum of the peak areas of all the components shown in the gas chromatography spectrum is 100, and the peak area of the corresponding component with respect to the total area of the peak is expressed in%.
[0040]
Then, fractional distillation is performed in order to remove the low boiling alcohol produced as a reaction byproduct. As described above, fractional distillation is promoted by nitrogen bubbling in the reaction vessel to promote fractional distillation, or by reducing the pressure in the reaction vessel to promote alcohol vaporization, or by mixing both methods. Desirably, fractional distillation is performed on the prepared composition so that the remaining amount of alcohol is 7 wt% to 8 wt% or less.
[0041]
(Resist removal method)
A method for removing a resist using a resist remover and a resist removing composition will be described with reference to FIG.
Various processes for completing a semiconductor element, for example, an etching (dry or wet) process, an ion implantation process, and the like are performed using a resist pattern as a mask. Next, the resist pattern is removed from the substrate (step 110). The resist pattern removal step is O ₂ A dry strip method using a plasma treatment method or a wet strip method using a solution such as a sulfuric acid solution is used.
[0042]
Next, the substrate on which the resist pattern is formed is brought into contact with the resist remover or the resist removing composition to remove the resist and the polymer (step 120). As a method of bringing the substrate into contact with the resist remover or the resist removing composition, the resist remover or the resist removing composition is placed in a bath and then immersed in the bath to remove the resist remover or resist. The contact is made with the composition or by spraying a resist remover or a resist removing composition onto the substrate.
[0043]
When using a resist remover or a resist removal composition, the resist removal step can be performed at a low temperature of 70 ° C. or lower. In particular, it is carried out at about 25 ° C to 70 ° C, preferably 45 ° C to 70 ° C. The contact time is 10 minutes to 30 minutes.
The resist removed by the resist remover or the resist removing composition is not limited to the existing resist for i-line (365 nm) and the resist for KrF excimer laser (248 nm), but also the resist for ArF excimer laser (193 nm). The present invention can also be applied to such a short wavelength exposure source resist.
[0044]
When the resist removal is completed, a step of washing the resist removing agent or the resist removing composition remaining on the substrate surface and the dissolved resist with water is performed (step 140). Washing with water is carried out using deionized water and may be carried out in two stages as necessary. Finally, the substrate is dried by a spin dry method or a dry method using isopropyl alcohol to remove deionized water remaining on the substrate surface (step 150).
[0045]
The substrate finished up to the drying stage is transferred to the next process. In the case of using the resist again in the subsequent process, after the target process is completed, the resist used through the process of FIG. 1 is removed again. In this way, the semiconductor device is completed through the repetitive unit process and resist removal process.
[0046]
As shown in FIG. 1, the resist remover or the resist removal composition of the present invention is excellent not only in resist removal power but also in polymer removal power, so that the conventional resist removal pretreatment step (step 100) indicated by the dotted line is unnecessary. It is. Further, since damage to the resist underlayer is prevented, the post-resist removal processing step (step 130) indicated by the dotted line can be omitted. Therefore, the resist can be completely removed by a process that is greatly simplified as compared with the conventional removal process, and the productivity of the semiconductor device can be remarkably improved.
[0047]
(Resist removal device)
Since the process for removing the resist can be simplified as described above, the resist removing apparatus using the resist remover or the resist removing composition can be downsized.
[0048]
As shown in FIG. 2, the resist removal apparatus 200 includes only a resist removal unit 210, a water washing unit 220, and a drying unit 230. Therefore, the pre-processing unit and the post-processing unit that are necessary in the conventional resist removing apparatus are unnecessary. That is, the volume required for the resist removing apparatus 200 can be significantly reduced as compared with the conventional case.
[0049]
When the resist removing apparatus 200 uses an immersion method, each of the resist removing unit 210, the water washing unit 220, and the drying unit 230 is configured by one bath. Therefore, the conventional nitric acid treatment bath and isopropyl alcohol treatment bath are unnecessary. Therefore, the volume required for the resist removing apparatus 200 can be greatly reduced as compared with the conventional one.
As the spray resist removal apparatus, a horizontal apparatus and a vertical apparatus can be applied.
[0050]
As shown in FIG. 3, the horizontal apparatus includes a carrier 340 such as a conveyor system, a handler or an arm that transports horizontally, a resist removal unit 310, a water washing unit 320, and a drying unit 330. The source 360 in which the resist remover or the resist removing composition is stored supplies the resist remover or the resist removing composition to the resist removing unit 310 through the supply unit 370. The water detergent source 362 and the desiccant source 364 are also connected to the water washing unit 320 and the drying unit 330 through the supply unit 370, respectively. Each unit is provided with nozzles 312, 322, 332 for spraying a substance suitable for the function of the unit.
[0051]
First, when a substrate on which a resist is formed is loaded onto the resist removing unit 310, a resist remover or a resist removing composition is sprayed from the nozzle 312 to remove the resist. At this time, the substrate is continuously moved in the horizontal direction by the carrier 340 and moved to the water washing unit 320. In the water washing unit 320, water detergent is sprayed through the nozzle 322. Finally, the substrate moves to the drying unit 330 through the carrier 340 and the drying process is performed. Since the horizontal apparatus is also composed of only three units, the volume required by the apparatus can be greatly reduced.
[0052]
As shown in FIG. 4, the vertical apparatus 400 uses a substrate support base 440 that can move up and down. The vertical apparatus 400 also includes a source 460 of a resist remover or resist removing composition, and a supply unit 470 that supplies the resist remover or resist removing composition. Desirably, the substrate support 440 is formed in a structure capable of rotating. The inside of the apparatus is not an independent unit, but has a layered structure in which three regions, that is, a drying region 430, a water washing region 420, and a resist removal region 410 are sequentially laminated. A water detergent source 462 and a desiccant source 464 are also connected to the supply tube 450 through each supply unit 470. The supply tube 450 shown in this embodiment supplies three different sources in sequence.
[0053]
First, a substrate (not shown) on which a resist is formed is loaded onto the substrate support 440 and then moved to the resist removal region 410. As the substrate moves to the resist removal area 410, the resist remover or resist removal composition in the source 460 of resist remover or resist removal composition is supplied to the supply unit 470 and sprayed onto the substrate through the supply tube 450. . At this time, it is desirable that the resist remover or the resist removing composition is discharged to a discharge unit (not shown) outside the substrate by the rotational movement of the substrate support 440. When the resist removal process is completed, the substrate is moved to the washing region 420 by the downward movement of the substrate support 440. A water detergent is supplied to the substrate through the supply pipe 450 to perform a water washing process. Finally, the substrate is moved to the drying region 430 by the movement of the substrate support 440, and the drying process is performed.
[0054]
Although FIG. 4 shows a structure in which the drying region 430, the water washing region 420, and the resist removal region 410 are stacked in this order, the order may be reversed. Since this vertical apparatus 400 also requires only three regions, the apparatus can be reduced in size and weight.
[0055]
Next, experimental examples to which the present invention is applied will be described. However, this experimental example does not limit the present invention.
(Experimental example 1: Production of methoxy N hydroxyethylpropanamide)
200 ml of monoethanolamine (hereinafter referred to as “MEA”) as an alkanolamine and 200 ml of methylmethoxypropanoate (hereinafter referred to as “MMP”) as an ester were mixed. The mixture was then heated at 90 ° C. for 5 hours and left at about 25 ° C. for 5 hours after heating.
[0056]
The resulting product was purified by gas chromatography to obtain the desired product.
The NMR data of the target product are as follows. ¹ H-NMR: 6.8 ppm (1H), 3.7 to 3.8 ppm (4H), 3.4 to 3.5 ppm (3H), 2.8 to 2.9 ppm (1H)
[0057]
(Experimental example 2: Production of methoxy N-butylhydroxyethylpropanamide) 200 ml of N, Nt-butylethanolamine and 200 ml of MMP were mixed. The mixture was then heated at 90 ° C. for 5 hours and left at about 25 ° C. for 5 hours after heating.
The resulting product was purified by gas chromatography to obtain the desired product.
[0058]
(Experimental example 3: Evaluation of appropriate temperature for production of methoxy N hydroxyethylpropanamide)
200 ml of MEA as alkanolamine and 200 ml of MMP as ester were mixed. Next, in order to investigate the temperature suitable for the reaction between the amine and the ester, methoxy N hydroxyethylpropanamide was synthesized while changing the reaction temperature as shown in Table 2 below, and the time required for the synthesis was measured. Completion of the synthesis was determined by analyzing the components by gas chromatography and setting the area ratio of the amide to be 80% or more.
[0059]
[Table 2]

[0060]
From the results in Table 2, it was found that the reaction was possible even at about 25 ° C., and it was found that the reaction occurred more rapidly as the temperature became higher. However, when considering other conditions in the manufacturing process, it is desirable that the reaction temperature does not exceed 120 ° C. Therefore, the production temperature of the amide compound according to the present invention is preferably about 25 ° C to 120 ° C, more preferably 80 ° C to 90 ° C.
[0061]
(Experimental example 4: Production of resist removing composition and evaluation of resist removing power using the composition)
As shown in Table 3 below, seven different compositions were prepared by changing the contents of monoethanolamine, methylmethoxypropanoate, catechol and water. The composition was then heated at 80 ° C. for 5 hours. Next, the heated composition was allowed to stand at about 25 ° C. for 6 hours, and then methanol was removed by a fractional distillation method in which a nitrogen bubbling method and a decompression method were performed in parallel to complete the composition.
[0062]
On the other hand, a resist to be removed with the resist removing composition described above was prepared as follows. First, a BPSG film having a thickness of 5000 mm was formed on the substrate. Next, a titanium film and a titanium nitride film were each formed to a thickness of 200 mm and then annealed. Next, an aluminum film was deposited to a thickness of 6000 mm and then allowed to flow. After forming a titanium nitride film on the aluminum film as a capping layer, an interlayer insulating film was formed to a thickness of 10,000 mm. Next, after applying a resist on the interlayer insulating film, a photographic process was performed to form a resist pattern that limited via holes. After baking the resist pattern, using this as a mask, the interlayer insulating film was etched with a buffer oxide etching solution to form a via hole. After completing the via hole, the substrate was subjected to an ashing process and immersed in a bath containing compositions having different compositions. The bath temperature was maintained at 60 ° C. After soaking for 20 minutes, the substrate was washed with water for 5 minutes and dried, and then the substrate was observed with a scanning electron microscope. According to the observation results, the substrate was graded as good, middle and top, and this grade is symbolized in Table 3.
[0063]
[Table 3]

[0064]
The symbol of the observation result indicates a state where ◯ is good, ◎ is better, and ● is the best.
[0065]
The observation results were classified according to the relative amounts of residual polymer and resist. Good state ○ is a state similar to the result using EKC-245 which is a conventional resist removing composition, middle upper state ◎ is an improved state from the conventional result, and the best state ● is the conventional state It shows a marked improvement. EKC-245 is a conventional resist removing composition mainly composed of hydroxylamine, diglycolamine, catechol and water.
[0066]
(Experimental example 5: Analysis of composition component)
After mixing each component in the ratio shown in Table 3, the components of each composition were analyzed after a predetermined time. As a result, it was found that each composition was composed of components as shown in Table 4 below.
[0067]
[Table 4]

[0068]
(Experimental example 6: Evaluation of appropriate processing time)
In order to investigate an appropriate value for the processing time, the resist was removed using the composition No. 4 shown in Table 4 while changing the processing time as shown in Table 5 below. Other process conditions were the same as those in Experimental Example 4. The resist removal state and the presence or absence of damage to the aluminum film and the silicon film were observed with a scanning electron microscope.
[0069]
[Table 5]

[0070]
In the symbols shown in Table 5 for the resist removing power and the presence / absence of damage, “◎” indicates the middle, “●” indicates the uppermost state, and “×” indicates that the underlying film was not damaged.
From the results of Table 5, it was found that the optimum processing time for the resist removal composition according to the present invention was 10 minutes to 30 minutes. In addition, damage to the underlying film could be completely prevented.
[0071]
(Experimental example 7: Evaluation of appropriate temperature)
In order to examine the proper processing temperature, the resist was removed using the composition shown in No. 4 of Table 4 and changing the processing time as shown in Table 6 below. Other process conditions were the same as those in Experimental Example 4. The resist removal state and the presence or absence of damage to the aluminum film and the silicon film were observed with a scanning electron microscope.
[0072]
[Table 6]

[0073]
From the results in Table 6, it can be seen that the resist removal is performed smoothly even at a low temperature of 45 ° C to 70 ° C.
[0074]
(Experimental example 8: Comparison of resist removing power)
The formation of the via hole using the resist pattern was the same as in Experimental Example 4, the composition No. 4 in Table 4 was used as the composition, the treatment time was 20 minutes, the reaction temperature was 60 ° C., and the resist was removed. After removing the resist, it was observed with a scanning electron microscope. The results are shown in FIG.
FIG. 6 shows a comparative example, which is the same as the above except that EKC-245 was used as the resist removing composition.
[0075]
Comparing the scanning electron micrographs of FIGS. 5 and 6, the resist is completely removed when using the resist removing composition of the present invention. On the other hand, it was found that when EKC-245, which is a conventional resist removing composition, is used, a part of the resist remains. Further, when the resist removing composition of the present invention was used, the aluminum film was not damaged. In contrast, it was found that when EKC-245 was used, the aluminum film was partially damaged.
[0076]
(Measurement of copper film damage)
In order to investigate the influence on copper wiring, which is a powerful next-generation wiring material, experiments were conducted as follows. As shown in FIG. 7, after forming a BPSG film on the substrate 1100 with a thickness of 5000 mm, the BPSG film on the substrate was patterned in a photolithography process to form a plurality of contact holes. Next, after the titanium / titanium nitride films 1300 and 1350 were sequentially formed with a thickness of 200 mm on the surface of the contact hole as a barrier metal film, a copper film 1400 for filling each contact hole was formed with a thickness of 10,000 mm.
[0077]
Next, the prepared substrates were classified into three groups A, B, and C. Group A does not use a resist removing composition, Group B uses a resist removing composition shown in No. 4 in Table 4 and is immersed for 100 minutes at 65 ° C. Group C is a conventional resist removing composition EKC-245, which is a group immersed at 65 ° C. for 100 minutes.
[0078]
And A group, B group, and C group were observed with the scanning electron microscope, respectively. The results are shown in FIGS. 7 to 9, where FIG. 7 shows the A group, FIG. 8 shows the B group, and FIG. 9 shows the C group. As shown in FIG. 8, in the case of Group B using the resist removal composition of the present invention shown in No. 4 of Table 4, the same results as those of Group A not using the resist removal composition as shown in FIG. became. That is, the resist removing composition of the present invention did not damage the copper film at all. On the other hand, in the case of group C subjected to the conventional EKC-245, the copper film was severely damaged and hardly remained as shown in FIG.
[0079]
When the etching rate of the copper film is calculated from the results shown in FIGS.
[0080]
[Table 7]

[0081]
Furthermore, in order to investigate the influence of the resist removing composition of the present invention on the surface of the copper film, the copper film of group A and the surface of the copper film of group B were analyzed with an Auger electron spectrometer. The results are shown in FIGS. 10 and 11, respectively.
Considering that the Auger electron spectroscopy spectra of FIGS. 10 and 11 are almost the same, it has been found that the resist removal composition of the present invention has no effect on the copper film.
[0082]
(Experimental Example 10: Measurement of change in constituent components of resist removing composition)
With respect to the composition shown in No. 4 in Table 3, the content of the constituent components of the resist composition was analyzed by gas chromatography every 8 hours. The analysis result is shown in FIG.
(2) indicates the area ratio (%) of the amide, Δ indicates the area ratio (%) of monoethanolamine, and × indicates the area ratio (%) of methylmethoxypropanoate.
[0083]
As shown in FIG. 12, even after 48 hours, the area ratio (%) of the amide is stable at 80%. The area ratio (%) of monoethanolamine is also almost constant at 3.4. The area percentage (%) of methylmethoxypropanoate decreased from 0.9 to 0.5 after 24 hours and became 0 after 40 hours.
[0084]
From the above, it can be seen that the amide, amine, catechol, and water are contained in the composition of the present invention after the reaction is completed and stabilized. And considering that the main active ingredient of this composition is amide, the content of amide did not change after 48 hours. It shows that it is possible. Compared to the fact that EKC-245, which is a conventional resist removal composition, needs to be replaced every 24 hours, it shows that productivity and manufacturing cost can be greatly reduced.
[0085]
【The invention's effect】
The resist remover or resist removing composition of the present invention not only has excellent resist removing power, but can efficiently remove polymers and organometallic polymers. Further, the exposed base film is not damaged by the resist remover or the resist removing composition of the present invention. Therefore, when the resist remover or the resist removing composition of the present invention is used, a resist removal pretreatment step for removing the polymer and a post-treatment step for preventing damage to the underlying film are unnecessary. Therefore, the resist removal process can be simplified and the processing time can be shortened. Moreover, the temperature at the time of resist removal can be set to a low temperature. Also, the resist removing apparatus can be simplified and reduced in weight.
[Brief description of the drawings]
FIG. 1 is a flowchart showing a resist removal method of the present invention.
FIG. 2 is a block diagram showing a resist removing apparatus for removing a resist using the resist remover or the resist removing composition of the present invention.
FIG. 3 is a schematic view showing a horizontal resist removing apparatus for removing a resist using the resist remover or the resist removing composition of the present invention.
FIG. 4 is a schematic view showing a vertical resist removing apparatus for removing a resist using the resist remover or the resist removing composition of the present invention.
FIG. 5 is a view showing a state where a resist is removed using the resist removing composition of the present invention.
FIG. 6 is a view showing a state where a resist is removed using a conventional resist removing composition.
FIG. 7 is a cross-sectional view showing a state before applying a resist removing composition to a substrate on which a copper film is formed.
FIG. 8 is a cross-sectional view showing a state after the resist removing composition of the present invention is applied to a substrate on which a copper film is formed.
FIG. 9 is a cross-sectional view showing a state after a conventional resist removing composition is applied to a substrate on which a copper film is formed.
FIG. 10 is a graph showing the surface of a copper film observed with an Auger electron spectrometer before applying the resist removing composition to the substrate on which the copper film is formed.
FIG. 11 is a diagram showing a graph obtained by observing the surface of a copper film with an Auger electron spectrometer after applying the resist removing composition of the present invention to the substrate on which the copper film is formed.
FIG. 12 is a diagram showing changes in the content of constituents of a resist composition.
[Explanation of symbols]
310 resist removal unit
312, 322, 332 nozzle
320 Flush unit
330 Drying unit
340 career
360 source
362 Water Detergent Sauce
364 Desiccant Sauce
370 Supply unit

Claims (37)

A resist remover comprising an alkoxy N-hydroxyalkylalkanamide. The alkoxy N-hydroxyalkylalkanamide is
R ₄ —O—R ₃ —CO—N—R ₁ R ₂ OH (Chemical Formula 1)
The resist remover according to claim 1, wherein
In the chemical formula 1, R ₁ is an H atom, a hydrocarbon having 1 to 5 carbon atoms, or an aromatic hydrocarbon having 1 to 3 benzene rings, and R ₂ is a hydrocarbon having 1 to 5 carbon atoms, or It is an aromatic hydrocarbon having 1 to 3 benzene rings, and R ₃ and R ₄ each represent a hydrocarbon having 1 to 5 carbon atoms. The R ₁ is an H atom, R ₂ is —CH ₂ —CH ₂ —, R ₃ is —CH ₂ —CH ₂ —, and R ₄ is —CH _3. 2. The resist remover according to 2. An alkoxy N-hydroxyalkylalkanamide;
A polar substance having a dipole moment of 3 or more, or one or both of damage prevention agents,
A resist removal composition comprising: The alkoxy N-hydroxyalkylalkanamide is
R ₄ —O—R ₃ —CO—N—R ₁ R ₂ OH (Chemical Formula 1)
The resist remover according to claim 1, wherein
In the chemical formula 1, R ₁ is an H atom, a hydrocarbon having 1 to 5 carbon atoms, or an aromatic hydrocarbon having 1 to 3 benzene rings, and R ₂ is a hydrocarbon having 1 to 5 carbon atoms, or It is an aromatic hydrocarbon having 1 to 3 benzene rings, and R ₃ and R ₄ each represent a hydrocarbon having 1 to 5 carbon atoms. The resist removing composition according to claim 4, wherein the polar substance is water, methanol, or dimethyl sulfoxide. The damage preventing agent is
R _6- (OH) _n (Chemical formula 2)
The resist removal composition according to claim 4, wherein the composition is a compound represented by the formula:
In the chemical formula 2, R ₆ is a hydrocarbon having 1 to 5 carbon atoms, a hydrocarbon having 1 to 5 carbon atoms to which a carboxyl group is bonded, an aromatic hydrocarbon having 1 to 3 benzene rings, or a carboxyl group. Any one of the aromatic hydrocarbons having 1 to 3 benzene rings, and n is an integer of 1 to 4. The resist removal composition according to claim 4, wherein the content of the alkoxy N-hydroxyalkylalkanamide is 30 wt% to 99.9 wt%. The resist removing composition according to claim 4, wherein the polar substance and the damage preventing agent each have a content of 0.01 wt% to 70 wt%. An alkoxy N-hydroxyalkylalkanamide;
Alkanolamine,
A resist removal composition comprising: The resist removing composition according to claim 10, further comprising one or both of a polar substance having a dipole moment of 3 or more and a damage preventing agent. The alkoxy N-hydroxyalkylalkanamide is
R ₄ —O—R ₃ —CO—N—R ₁ R ₂ OH (Chemical Formula 1)
The resist remover according to claim 10, which is represented by:
In the chemical formula 1, R ₁ is an H atom, a hydrocarbon having 1 to 5 carbon atoms, or an aromatic hydrocarbon having 1 to 3 benzene rings, and R ₂ is a hydrocarbon having 1 to 5 carbon atoms, or It is an aromatic hydrocarbon having 1 to 3 benzene rings, and R ₃ and R ₄ each represent a hydrocarbon having 1 to 5 carbon atoms. The alkanolamine is
R ₁ —NH—R ₂ —OH (Chemical Formula 3)
The composition for removing a resist according to claim 10, which is represented by:
In Formula 3, R ₁ is an H atom, a hydrocarbon having 1 to 5 carbon atoms, or an aromatic hydrocarbon having 1 to 3 benzene rings, and R ₂ is a hydrocarbon having 1 to 5 carbon atoms, or An aromatic hydrocarbon having 1 to 3 benzene rings is shown. 12. The resist removal composition according to claim 11, wherein the polar substance is water, methanol, or dimethyl sulfoxide. The damage preventing agent is
R _6- (OH) _n (Chemical formula 2)
The composition for removing a resist according to claim 11, which is a compound represented by the formula:
In the chemical formula 2, R ₆ is a hydrocarbon having 1 to 5 carbon atoms, a hydrocarbon having 1 to 5 carbon atoms to which a carboxyl group is bonded, an aromatic hydrocarbon having 1 to 3 benzene rings, or a carboxyl group. Any one of the aromatic hydrocarbons having 1 to 3 benzene rings, and n is an integer of 1 to 4. The resist removal composition according to claim 10, wherein the content of the alkoxy N-hydroxyalkylalkanamide is 30 wt% to 99.9 wt%. The resist removal composition according to claim 10, wherein the content of the alkanolamine is 0.1 wt% to 70 wt%. 12. The resist removing composition according to claim 11, wherein the polar substance and the damage preventing agent are each 0.01% to 30% by weight. 40% to 65% by weight of the alkoxy N-hydroxyalkylalkanamide, 5% to 30% by weight of alkanolamine, 5% to 20% by weight of polar substance, and 5% to The resist removing composition according to claim 11, comprising 20% by weight. Mixing stage for mixing alkanolamine and alkylalkoxyalkanoate;
Reacting the mixture to react;
A method for producing a composition for removing a resist, comprising: The alkanolamine is
R ₁ —NH—R ₂ OH (Chemical Formula 3)
Indicated by
The alkylalkoxyalkanoate is
_{R 4 -O-R 3 -COO-} R 5 ( Formula 4)
The method for producing a resist removing composition according to claim 20, wherein
In Chemical Formula 3 and Chemical Formula 4, R ₁ is an H atom, a hydrocarbon having 1 to 5 carbon atoms, or an aromatic hydrocarbon having 1 to 3 benzene rings, and R ₂ is a carbon atom having 1 to 5 carbon atoms. It is hydrogen or an aromatic hydrocarbon having 1 to 3 benzene rings, and R ₃ , R ₄ and R ₅ each represent a hydrocarbon having 1 to 5 carbon atoms. 21. The resist removal composition according to claim 20, wherein 10% by weight to 70% by weight of the alkanolamine and 10% by weight to 70% by weight of the alkylalkoxyalkanoate are mixed in the mixing step. Manufacturing method. 21. The method of manufacturing a resist removing composition according to claim 20, wherein in the mixing step, one or both of a polar substance having a dipole moment of 3 or more and a damage preventing agent are further mixed. 21. The method for producing a resist removal composition according to claim 20, wherein the polar substance and the damage inhibitor are each contained in an amount of 0.01 wt% to 30 wt%. 21. The method of manufacturing a resist removing composition according to claim 20, wherein the reaction step is performed at 25 to 120 [deg.] C. 21. The method of manufacturing a resist removing composition according to claim 20, further comprising the step of removing alcohol as a by-product of the reaction after the reaction step. A preparation stage for preparing a substrate;
A resist film forming step of forming a resist film on the substrate;
The substrate is selected from the group consisting of a resist removing agent comprising an alkoxy N-hydroxyalkylalkanamide, or the alkoxy N-hydroxyalkylalkanamide, a polar substance having a dipole moment of 3 or more, a damage inhibitor, and an alkanolamine. A contact step of removing the resist film from the substrate by contacting with a resist removal composition comprising one or more compounds;
A resist removal method comprising: The alkoxy N-hydroxyalkylalkanamide is
R ₄ —O—R ₃ —CO—N—R ₁ R ₂ OH (Chemical Formula 1)
28. The resist removal method according to claim 27, wherein:
In the chemical formula 1, R ₁ is an H atom, a hydrocarbon having 1 to 5 carbon atoms, or an aromatic hydrocarbon having 1 to 3 benzene rings, and R ₂ is a hydrocarbon having 1 to 5 carbon atoms, or It is an aromatic hydrocarbon having 1 to 3 benzene rings, and R ₃ and R ₄ each represent a hydrocarbon having 1 to 5 carbon atoms. 28. The resist removing method according to claim 27, wherein the polar substance is any one of water, methanol, and dimethyl sulfoxide. The damage preventing agent is
R _6- (OH) _n (Chemical formula 2)
28. The resist removal method according to claim 27, wherein the compound is represented by the formula:
In the chemical formula 2, R ₆ is a hydrocarbon having 1 to 5 carbon atoms, a hydrocarbon having 1 to 5 carbon atoms to which a carboxyl group is bonded, an aromatic hydrocarbon having 1 to 3 benzene rings, or a carboxyl group. Any one of the aromatic hydrocarbons having 1 to 3 benzene rings, and n is an integer of 1 to 4. The alkanolamine is
R ₁ —NH—R ₂ —OH (Chemical Formula 3)
28. The resist removal method according to claim 27, wherein:
In Formula 3, R ₁ is an H atom, a hydrocarbon having 1 to 5 carbon atoms, or an aromatic hydrocarbon having 1 to 3 benzene rings, and R ₂ is a hydrocarbon having 1 to 5 carbon atoms, or An aromatic hydrocarbon having 1 to 3 benzene rings is shown. 28. The resist removal method according to claim 27, wherein the content of the alkoxy N-hydroxyalkylalkanamide is 30% by weight to 99.9% by weight. 28. The resist removal method according to claim 27, wherein the polar substance and the damage preventing agent are each contained in an amount of 0.01 wt% to 30 wt%. 28. The resist removal method according to claim 27, wherein a content of the alkanolamine is 0.1 wt% to 70 wt%. The resist removal composition comprises 40% to 65% by weight of the alkoxy N-hydroxyalkylalkanamide, 5% to 30% by weight of the alkanolamine, 5% to 20% by weight of the polar substance, and 28. The resist removal method according to claim 27, comprising 5 to 20% by weight of the damage preventing agent. After the contacting step,
Cleaning the substrate;
28. The method of removing a resist according to claim 27, further comprising the step of drying the substrate. 28. The method of removing a resist according to claim 27, wherein the contacting step is performed at 45 [deg.] C. to 70 [deg.] C.

Images