JP4575651B2

JP4575651B2 - Manufacturing method of laminated structure and laminated structure

Info

Publication number: JP4575651B2
Application number: JP2003159534A
Authority: JP
Inventors: 睦也高橋; 高幸山田; 宏之堀田; 崇之後藤; 武志津野; 雅人木ノ内
Original assignee: Fuji Xerox Co Ltd; Mitsubishi Heavy Industries Ltd; Fujifilm Business Innovation Corp
Current assignee: Mitsubishi Heavy Industries Ltd; Fujifilm Business Innovation Corp
Priority date: 2003-06-04
Filing date: 2003-06-04
Publication date: 2010-11-04
Anticipated expiration: 2023-06-04
Also published as: JP2004358602A

Description

【０００１】
【発明の属する技術分野】
本発明は、積層造形方法によって製造される微小光学部品や微小機械部品、あるいは、これらを形成する金型などの微小構造体を製造する積層構造体の製造方法および積層構造体に関し、特に高さが数百ミクロン以上となる積層構造体の製造方法および積層構造体に関する。
【０００２】
【従来の技術】
積層造形方法は、コンピュータで設計された複雑な形状の３次元物体を短納期で形成する方法として近年急速に普及している。積層造形方法で作成された３次元物体は、種々の装置の部品モデル(プロトタイプ)として、部品の動作や形状の良否を調べるために利用される。この方法が適用される部品のサイズは、数ｃｍ以上の比較的大きな部品が多かったが、精密に加工して形成される微小光学部品や微小機械部品などの微小構造体の製造にも、この方法を適用したいという要求がある。
【０００３】
図９〜図１３を参照して、上記のような積層造形方法を適用した第１の従来例による積層構造体の製造方法を説明する。
【０００４】
図９（ａ）に示すように、シリコンウエハ基板１１を準備し、ポリイミドによる離型層１２を形成し、続いて積層構造体の構成材料であるＡｌ薄膜１３をスパッタ法、あるいは真空蒸着法などにより０．５μｍ着膜する。離型層１２はＡｌ薄膜１３との密着力を適正に保つ役割をする。
【０００５】
図９（ｂ）に示すように、フォトリソグラフィー法によりＡｌ薄膜１３を積層構造体の断面形状に一括してパターニングし、複数の断面パターン部材１３−１，１３−２を形成する。この断面パターン部材１３−１，１３−２が形成された基板全体をドナー基板１５と呼ぶ。
【０００６】
図１０に示すように、真空槽２１中のＸＹθステージ２２上にドナー基板１５を固定する。また、ＸＹθステージ２２上方のＺステージ２３に、断面パターン部材１３−１，１３−２を積層するターゲット基板２４を固定する。そして、真空槽２１内を真空に排気した後、ターゲット基板２４の表面２４ａおよび断面パターン部材１３−１の表面１３−１ａにＡｒ中性ビームからなるＦＡＢ(Fast Atom Beam)２６をＦＡＢ源２５から照射し、ターゲット基板２４および断面パターン部材１３−１の表面を清浄化する。
【０００７】
図１１に示すように、Ｚステージ２３を下降させ、ターゲット基板２４の表面２４ａと一方の断面パターン部材１３−１を当接させ、更に荷重として５０ｋｇｆ／ｃｍ²を掛け、５分間押し付けておくと、ターゲット基板２４と断面パターン部材１３−１が強固に接合する。なお、その接合強度は５０〜１００ＭＰａである。
【０００８】
図１２に示すように、Ｚステージ２３を上昇させると、断面パターン部材１３−１はドナー基板１５からターゲット基板２４に転写される。これは、ドナー基板１５上の断面パターン部材１３−１と、この下の離型層１２の密着力よりも、断面パターン部材１３−１とターゲット基板２４との接合力の方が大きいためである。
【０００９】
図１３に示すように、図１０〜図１２の工程を繰り返してターゲット基板２４に他の断面パターン部材１３−２を転写して積層構造体２７を形成し、最後に積層構造体２７をターゲット基板２４から取り外す（特許文献１参照。）。
【００１０】
図１４, 図１５を参照して、第２の従来例による積層構造体の製造方法を説明する。
【００１１】
図１４（ａ）に示すように、シリコンウエハ基板３１の上下面に熱酸化膜３２−１，３２−２が形成された支持基板３３を準備する。支持基板３３は、平面度に留意して平面度が数ミクロン程度のものを用いる。
【００１２】
図１４（ｂ）に示すように、支持基板３３の熱酸化膜３２−１の上面に密着力強化剤を塗布した後、フォトレジストをスピン塗布して接着層３４を形成する。
密着力強化剤を塗布することにより支持基板３３と接着層３４との間の密着力を、接着層３４と後述する図１４（ｃ）に示す板状部材３５との間の接着力よりも大きくなるようにしている。
【００１３】
図１４（ｃ）に示すように、両面が鏡面研磨され、平面度が数ミクロン程度で、厚さ５００ミクロンのシリコンウエハからなり、上面にだけ酸化膜３６が形成された板状部材３５を準備し、上記接着層３４が乾く前に板状部材３５を貼り付け、その後、１５０℃、３０分間ベイクして、２枚の支持基板３３と板状部材３５を接着する。
【００１４】
図１５（ａ）に示すように、通常のフォトリソグラフィー法にて板状部材３５の表面の酸化膜３６を、最終的に製造される構造体の各断面形状に一括してパターニングし、酸化膜パターン層３６−１，３６−２を得る。エッチングは図示しないレジストパターンをマスクとし、バッファードフッ酸により行う。
【００１５】
図１５（ｂ）に示すように、その基板全体を図示せぬ誘導結合型プラズマ（ＩＣＰ：Inductive coupled plasma）エッチング装置に導入し、酸化膜パターン層３６−１，３６−２をマスクとして、板状部材３５が支持基板３３の上面位置まで貫通するようにエッチングし、断面パターン部材３５−１，３５−２を得る。
【００１６】
図１５（ｃ）に示すように、酸化膜パターン層３６−１，３６−２をバッファードフッ酸によりエッチングすることによって、構造体の断面パターン部材３５−１，３５−２が形成されたドナー基板３７を得る。
【００１７】
次に、第１の従来例で説明した図１０〜図１３と同様に、ターゲット基板２４に複数の断面パターン部材３５−１，３５−２を転写して積層構造体を形成し、最後に積層構造体をターゲット基板２４から取り外す。この第２の従来例においては、第１の従来例のように断面パターン部材１３−１，１３−２となるＡｌ薄膜１３を着膜する代わりに、断面パターン部材３５−1、３５−２となる厚い板状部材３５を支持基板３３に貼り付けているため、短時間で厚い断面パターン部材３５−１，３５−２を形成することができる。また、断面パターン部材３５−１，３５−２も厚いので積層数も減らすことができる。従って、短時間で積層構造体を製造することができる（特許文献２参照。）。
【００１８】
【特許文献１】
特許第３１６１３６２号
【特許文献２】
特開２００２−１８７９８号公報
【００１９】
【発明が解決しようとする課題】
しかし、従来の特許文献１による積層構造体の製造方法においては、厚さ０．５μｍの薄膜である断面パターン部材１３−１，１３−２を積層して、高さ数１００μｍから数ｍｍの積層構造体２７を製造するため、積層数が非常に多くなり、製造時間が長くなる。積層数を減らすためには、薄膜の厚さを数１０μｍから数１００μｍと厚くすればよいが、スパッタ法や真空蒸着法の着膜速度は０．０５〜０．１μｍ／分程度と遅いため、薄膜の着膜に時間がかかる。このように、薄膜の着膜、あるいは積層に多大な時間がかかるという問題があった。
【００２０】
一方、特許文献２の積層構造体の製造方法においては、支持基板３３に板状部材３５を貼り付けるときの押し付け力を適切な大きさにする必要があり、押し付け力が大きいと硬化前の軟質の接着層３４が両者の間からはみ出して無くなってしまい、逆に押し付け力が小さいと板状部材３５が接着層３４に確実に密着せず接着力が低下する。接着層３４がない部分や密着力が低下した部分は、パターニング工程を経るうちに断面パターン部材３５−１，３５−２が支持基板３３から剥がれてしまう。断面パターン部材３５−１，３５−２が剥がれないようにするためには押し付け力を適切とすればよいが、そのマージンが小さいため適切な押し付け力とすることが難しい。従って、歩留まり良く、断面パターン部材３５−１，３５−２を形成することが難しいため、製造する積層構造体の歩留まりが低下するという問題があった。
【００２１】
本発明は、かかる点に鑑みてなされたものであり、高さが数１００μｍ以上となる積層構造体を、短時間で歩留まり良く製造することができる積層構造体の製造方法および積層構造体を提供することを目的とする。
【００２２】
【課題を解決するための手段】
本発明は、上記目的を達成するため、構造体の断面パターンに対応する複数の断面パターン部材が形成されたドナー基板を準備し、前記ドナー基板にターゲット基板を対向配置し、このターゲット基板を前記断面パターン部材に位置合わせして圧接したのち離間を行う処理を繰り返すことによって、前記断面パターン部材を積層して接合された積層構造体を前記ターゲット基板上に形成する積層構造体の製造方法において、前記ドナー基板の準備は、前記ドナー基板上に離型層および２層以上から構成される導電層を順次形成し、前記構造体の断面パターンを反転した反転パターン層を前記導電層上に形成する第１の工程と、前記反転パターン層の前記構造体の断面パターンに対応する空間部分にメッキにより前記複数の断面パターン部材を形成する第２の工程と、前記反転パターン層を除去する第３の工程を含み、前記断面パターン部材の接合は、接合面を清浄化し、清浄化した前記接合面を直接接触させて行うことを特徴とする積層構造体の製造方法を提供する。
【００２３】
この方法によれば、着膜速度が速いメッキによって断面パターン部材を形成するようにしたので、厚い断面パターン部材を短時間で形成することができる。
【００２４】
本発明は、上記目的を達成するため、構造体の断面パターンに対応する複数の断面パターン部材の各々の間に軟質金属からなる層を介して積層され、前記軟質金属からなる前記層の清浄化された接合面と前記断面パターン部材の清浄化された接合面とが直接接触して接合され、前記軟質金属からなる前記層が２層以上から構成されることを特徴とする積層構造体を提供する。
【００２５】
この構成によれば、軟質金属からなる層を電極として断面パターン部材をメッキによって形成することができる。軟質金属からなる層は、断面パターン部材同士を圧接したとき、塑性変形するため、断面パターン部材同士の密着性が向上し、接合力が高くなる。
【００２６】
【発明の実施の形態】
図１（ａ）〜（ｄ）に、本発明の第１の実施の形態に係る積層構造体の製造工程を示す。本実施の形態と従来技術との違いはドナー基板の製造方法である。
【００２７】
図１（ａ）に示すように、シリコンウエハ基板４１上に、後述する断面パターン部材との密着力を適切な範囲に制御することができる離型層４２を形成し、この上に後述するメッキ処理を行うための導電層４３を形成する。
【００２８】
図１（ｂ）に示すように、フォトリソグラフィー法により、数１０〜数１００ミクロンの膜厚を有する厚いレジストパターン層４４−１，４４−２，４４−３を形成する。なお、このレジストパターン層４４−１，４４−２，４４−３は、積層構造体の断面パターンを反転した形状になっている。
【００２９】
図１（ｃ）に示すように、導電層４３を電極として短時間で厚い膜を形成することができるメッキ処理により、レジストパターン層４４−１，４４−２，４４−３の間に構造体材料を埋め込んで断面パターン部材４５−１，４５−２を形成する。メッキ処理における着膜速度は、数μｍ／分とスパッタのそれに比べて数１０倍早い。
【００３０】
図１（ｄ）に示すように、レジストパターン層４４−１，４４−２，４４−３を除去し、積層構造体の断面パターン部材４５−１，４５−２をマスクにして導電層４３を、４３−１，４３−２で示すようにエッチングする。これによってドナー基板４６が完成する。
【００３１】
図２に示すように、真空槽２１中のＸＹθステージ２２上にドナー基板４６を固定すると共に、断面パターン部材４５−１，４５−２が積層されるターゲット基板２４をＺステージ２３上に固定し、ターゲット基板２４とドナー基板４６の表面２４ａ，４５−１ａにＦＡＢ源２５からＦＡＢ２６を照射し、両者の表面２４ａ，４５−１ａを清浄化する。
【００３２】
図３に示すように、Ｚステージ２３を下降させてターゲット基板２４とドナー基板４６を当接させ、荷重を印加した後、Ｚステージ２３を上昇させる。
【００３３】
図４に示すように、ターゲット基板２４に、断面パターン部材４５−１と共に導電層４３−１が転写される。これは、導電層４３−１が接しているのが離型層４２であり、離型層４２と導電層４３−１の密着力が、ターゲット基板２４と断面パターン部材４５−１との接合力、および断面パターン部材４５−１と導電層４３−１との密着力よりも弱いためである。
【００３４】
図５に示すように、ＸＹθステージ２２を動かして、ターゲット基板２４に転写済みの断面パターン部材４５−１に密着された導電層４３−１と、断面パターン部材４５−２との位置合わせを行った後、両者４３−１，４５−２の表面４３−１ａ，４５−２ａにＦＡＢ２６を照射して、その表面４３−１ａ，４５−２ａを清浄化する。この後、図３に示したように、Ｚステージ２３を下降させて両者４３−１，４５−２を当接させ、荷重を印加した後、Ｚステージ２３を上昇させる。
【００３５】
図６に示すように、導電層４３−１に、断面パターン部材４５−２と共に導電層４３−２が転写される。このように、断面パターン部材を繰り返し転写して積層することにより、積層構造体５１を製造する。
【００３６】
このように、第１の実施の形態によれば、着膜速度が速いメッキによって断面パターン部材４５−１，４５−２を形成するようにしたので、厚い断面パターン部材４５−１，４５−２を短時間で形成することができる。このため、断面パターン部材４５−１，４５−２の積層数も減らすことができ、高さが数１００μｍ以上となる積層構造体５１を短時間で製造することができる。
【００３７】
また、従来の図１４に示したように支持基板３３と板状部材３５とを貼り付けずに、離型層４２の上に断面パターン部材４５−１，４５−２を形成するようにしたので、離型層４２と断面パターン部材４５−１，４５−２との密着力を適正かつ確実に保持することができ、パターニング工程中に断面パターン部材４５−１，４５−２が基板から剥がれてしまうこともない。これによって、歩留まりを向上させることができる。従って、高さが数１００μｍ以上となる積層構造体５１を、短時間で歩留まり良く製造することができる。
【００３８】
なお、この第１の実施の形態は、次のように様々に変形可能である。
【００３９】
例えば、上記の図１（ｄ）に示した工程では、露出している導電層４３を除去する形態を示したが、必ずしも除去しなくてもよい。しかし、除去した方が次の理由により好ましい。離型層４２と接しているのは導電層４３であるため、断面パターン部材４５−１，４５−２を転写するときに剥がれが生じるのは、導電層４３と離型層４２との界面である。
【００４０】
また、図４に示したように、その剥がれによって断面パターン部材４５−１と共に導電層４３−１も転写される。この際、導電層４３−１と離型層４２との密着力は、両者４３−１と４２が接している面積が小さいほうが低くなる。従って、密着力が低くなって転写しやすくなるように、図１（ｄ）に示すように余分な導電層４３をエッチングして除去することが好ましい。また、導電層４３−１、４３−２は断面パターン部材４５−１、４５−２をマスクにして選択的にエッチングして除去したが、必ずしも選択性がなく、断面パターン部材が同時にエッチングされてもよい。断面パターン部材がエッチングされる場合には、最終的に所定の厚さとなるよう、予め、断面パターン部材のエッチング量分だけ厚く断面パターン部材をメッキにより形成しておくことが好ましい。
【００４１】
また、導電層４３としては、導電性を有する材料であればよく、必要に応じて２層以上としてもよい。上層（断面パターン部材側）をＡｕとすることによりメッキ材料の選択性が広がり、また下層（離型層側）をアルミニウムあるいはアルミニウム合金として離型層をポリイミドとすることにより導電層と離型層の密着力が最も適切となる。また、純Ａｌ、Ａｌ−Ｃｕ合金、Ａｕなどの軟質な金属材料で構成することが好ましい。また、この理由を次に述べる。
【００４２】
図４に示したように、断面パターン部材４５−１と共に導電層４３−１が転写されるため、次の断面パターン部材４５−２とは導電層４３−１が接合することになる。断面パターン部材４５−２の接合面には、表面粗さに対応する凸凹が存在するが、導電層４３−１が軟質である方が接合する際に、導電層４３−１が塑性変形して、その接合面の凸凹が埋まって当接面積が広くなり接合強度が増すので断面パターン部材４５−２が転写しやすくなる。従って、導電層４３は軟質である方が好ましい。また、導電層の形成方法は、メッキやスパッタなどの薄膜形成方法ならば何でも良く、導電層の構成などにより適宜選択される。例えば、前述したような、導電層の上層をＡｕ、下層をアルミニウムの２層構造とする場合には、アルミニウムの上にＡｕをメッキで形成することは難しいので、Ａｕはスパッタにより形成することが好ましい。
【００４３】
また、純Ａｌ、Ａｌ−Ｃｕ合金、Ａｕなどの軟質な材料を接合面となる断面パターン部材４５−１，４５−２の上（表面）に形成しても、同様に接合強度が増すので好ましい。ただし、軟質な導電層４３が積層構造体５１に含まれて剛性が低下するため、高い剛性を必要とする積層構造体を製造する場合は好ましくない。
【００４４】
次に、このような高い剛性を必要とする積層構造体を製造する第２の実施の形態に係る積層構造体の製造方法を説明する。
【００４５】
図１（ａ）および（ｂ）に示した工程を経た後、図１（ｃ）に示したメッキ処理工程において、レジストパターン層４４−１，４４−２，４４−３の間に断面パターン部材４５−１，４５−２を形成した後、レジストパターン層４４−１，４４−２，４４−３および断面パターン部材４５−１，４５−２全ての上面を研磨することによって、断面パターン部材４５−１，４５−２の接合面の凹凸を無くし、平滑面とする。そして、図１（ｄ）に示したように、レジストパターン層４４−１，４４−２，４４−３を除去し、断面パターン部材４５−１，４５−２をマスクにして導電層４３を、４３−１，４３−２で示すようにエッチングし、ドナー基板４６を完成させる。
【００４６】
ただし、断面パターン部材４５−１，４５−２の接合面を平滑面とする処理は、図１（ｄ）に示したレジストパターン層４４−１，４４−２，４４−３の除去後に行っても良い。
【００４７】
図２に示したように、真空槽２１中のＸＹθステージ２２上にドナー基板４６を固定すると共に、ターゲット基板２４をＺステージ２３上に固定し、ＦＡＢ２６の照射によってターゲット基板２４とドナー基板４６の表面２４ａ，４５−１ａを清浄化する。
【００４８】
図３に示したように、Ｚステージ２３を下降させて両者２４，４６を当接させ、荷重を印加した後、Ｚステージ２３を上昇させ、図４に示したように、ターゲット基板２４に、断面パターン部材４５−１と共に導電層４３−１を転写する。
【００４９】
図７に示すように、ＸＹθステージ２２を動かして、ターゲット基板２４に転写済みの断面パターン部材４５−１に密着された導電層４３−１（図３参照）と、断面パターン部材４５−２との位置合わせを行った後、次の断面パターン部材４５−２を接合する前の表面清浄化を行う。この際、ＦＡＢ２６の照射により導電層４３−１をエッチングして導電層４３−１を除去する。この後、Ｚステージ２３を下降させて、ターゲット基板２４上の断面パターン部材４５−１とドナー基板４６上の断面パターン部材４５−２を当接させ、荷重を印加した後、Ｚステージ２３を上昇させる。
【００５０】
図８に示すように、断面パターン部材４５−１に他の断面パターン部材４５−２が転写される。
【００５１】
第２の実施の形態によれば、導電層４３が除去された断面パターン部材を繰り返し転写して積層することにより、導電層４３が間に介在しない高い剛性の積層構造体を製造することができる。断面パターン部材４５−１，４５−２の上面は、平滑面であるので、断面パターン部材同士の接合強度が大きくなる。
【００５２】
ただし、断面パターン部材４５−１と４５−２同士が確実に接合されるように、導電層４３−１，４３−２と離型層４２との密着力が最も適切となるように、導電層４３を純ＡｌあるいはＡｌ−Ｃｕ合金とし、離型層４２をポリイミドとすることが望ましい。
【００５３】
また、図１（ｂ）に示した反転パターンは、その形状精度が良好となるように、厚膜レジストをリソグラフィー法によりパターニングして形成することが好ましい。このようなパターニング方法としては光、あるいはＸ線に感光する厚膜レジストを用いてパターニングする方法があるが、より低コストとなる光に感光する厚膜レジストを用いてパターニングするのが更に好ましい。
【００５４】
【実施例】
以下、このような効果を奏する積層構造体の製造方法によって、実際に積層構造体５１を製造した工程を、上記の図１〜図６を参照して説明する。
【００５５】
図１（ａ）に示すように、シリコンウエハ基板４１を準備し、その基板４１の表面にポリイミドをスピンコート法により塗布し、最高温度３５０℃でベークし、離型層４２を形成した。続いて、厚さ０．５μｍのＡｕをスパッタ法により着膜して導電層４３を形成した。
【００５６】
図１（ｂ）に示すように、導電層４３の上に膜厚５０μｍの厚膜レジストを形成した後、露光・現像を行って、積層構造体の断面パターンを反転した形状のレジストパターン層４４−１，４４−２，４４−３を形成した。
【００５７】
図１（ｃ）に示すように、メッキを行って、レジストパターン層４４−１，４４−２，４４−３の間にＣｕを膜厚５０μｍとなるまで形成することによって、断面パターン部材４５−１，４５−２を形成した。なお、Ｃｕの着膜速度は２μｍ／分であった。なお、断面パターン部材４５−１，４５−２は、Ｎｉであってもよい。
【００５８】
図１（ｄ）に示すように、レジストパターン層４４−１，４４−２，４４−３をアッシングして除去した後、断面パターン部材４５−１，４５−２をマスクにして、導電層４３を選択的にエッチングし、ドナー基板４６を製造した。
【００５９】
図２に示すように、真空槽２１中のＸＹθステージ２２上にドナー基板４６を固定し、Ｚステージ２３上にターゲット基板２４を固定し、槽内を５×１０^-5Ｐａまで真空排気した。続いて、ターゲット基板２４と断面パターン部材４５−１の表面２４ａ，４５−１ａに、ＦＡＢ源２５からＦＡＢ２６照射し、表面活性化処理を施した。ＦＡＢ処理条件は、ＦＡＢ電圧１．５ｋＶ、ＦＡＢ電流１５ｍＡ、処理時間５分とした。
【００６０】
図３に示すように、Ｚステージ２３を下降させ、ターゲット基板２４と断面パターン部材４５−１とを当接させ、更に荷重として５０ｋｇｆ／ｃｍ²を掛け、５分間押し付けた。この結果、ターゲット基板２４と断面パターン部材４５−１とが強固に接合した。なお、その接合強度は５０〜１００ＭＰａである。
【００６１】
図４に示すように、Ｚステージ２３を上昇させると、断面パターン部材４５−１は、ドナー基板４６からターゲット基板２４に転写された。
【００６２】
図５に示すように、ＸＹθステージ２２を動かして、ターゲット基板２４に転写済みの断面パターン部材４５−１に密着された導電層４３−１と、断面パターン部材４５−２との位置合わせを行った後、両者４３−１，４５−２の表面４３−１ａ，４５−２ａにＦＡＢ２６を照射して、その表面４３−１ａ，４５−２ａを清浄化した。この後、図３に示したように、Ｚステージ２３を下降させて両者４３−１，４５−２を当接させ、荷重を印加した後、Ｚステージ２３を上昇させた。
【００６３】
図６に示すように、導電層４３−１に、断面パターン部材４５−２と共に導電層４３−２が転写される。このように、断面パターン部材を繰り返し転写して積層することにより、積層構造体５１を製造した。このように本実施例によれば、高さが数１００μｍ以上となる積層構造体５１を、短時間で歩留まり良く製造することができた。
【００６４】
【発明の効果】
以上説明したように、本発明の積層構造体の製造方法によれば、着膜速度が速いメッキによって断面パターン部材を形成するようにしたので、厚い断面パターン部材を短時間で形成することができる。このため、断面パターン部材の積層数も減らすことができ、高さが数１００μｍ以上となる積層構造体を短時間で製造することができる。また、従来のように支持基板と板状部材とを貼り付けずに、離型層の上に断面パターン部材を形成するようにしたので、離型層と断面パターン部材との密着力を適正かつ確実に保持することができ、パターニング工程中に断面パターン部材が基板から剥がれてしまうこともない。これによって、歩留まりを向上させることができる。
【００６５】
本発明の積層構造体によれば、軟質金属からなる層電極として複数断面パターン部材を、着膜速度の速いメッキによって形成できるので、高さが数１００μｍ以上となる積層構造体を、短時間で歩留まり良く製造することができる。
【図面の簡単な説明】
【図１】本発明の第１の実施の形態に係る積層構造体の製造工程を示し、（ａ）はシリコンウエハ基板上への離型層および導電層の形成工程、（ｂ）は積層構造体の断面の反転パターンであるレジストパターン層の形成工程、（ｃ）はレジストパターン層の間への断面パターン部材形成のためのメッキ処理工程、（ｄ）は断面パターン部材を形成したドナー基板形成のためのエッチング工程を示す図である。
【図２】真空槽中においてドナー基板とターゲット基板との表面を清浄化する工程を示す図である。
【図３】真空槽中においてドナー基板にターゲット基板による荷重を印加する工程を示す図である。
【図４】真空槽中においてターゲット基板に断面パターン部材と共に導電層を転写する工程を示す図である。
【図５】真空槽中においてＸＹθステージを動かして、ターゲット基板に転写済みの断面パターン部材に密着された導電層と、断面パターン部材との位置合わせを行い、両者の表面を清浄化する工程を示す図である。
【図６】真空槽中において断面パターン部材の導電層に、他の断面パターン部材と共に導電層を転写する工程を示す図である。
【図７】真空槽中においてターゲット基板に断面パターン部材と共に導電層を転写した後、その導電層を除去する工程を示す図である。
【図８】真空槽中においてターゲット基板の断面パターン部材に直接、他の断面パターン部材を転写する工程を示す図である。
【図９】第１の従来例における積層構造体の製造工程を示し、（ａ）はシリコンウエハ基板上への離型層およびＡｌ薄膜の形成工程、（ｂ）は断面パターン部材を形成したドナー基板形成のためのエッチング工程を示す図である。
【図１０】第１の従来例において真空槽中でドナー基板とターゲット基板との表面を清浄化する工程を示す図である。
【図１１】第１の従来例において真空槽中でドナー基板にターゲット基板による荷重を印加する工程を示す図である。
【図１２】第１の従来例において真空槽中でターゲット基板に断面パターン部材を転写する工程を示す図である。
【図１３】第１の従来例において真空槽中でターゲット基板の断面パターン部材に他の断面パターン部材を転写する工程を示す図である。
【図１４】第２の従来例における積層構造体の製造工程を示し、（ａ）はシリコンウエハ基板の上下面に熱酸化膜を形成した支持基板の形成工程、（ｂ）は支持基板の熱酸化膜上面への接着層の形成工程、（ｃ）は支持基板に接着層を介して表面に酸化膜が形成された板状部材を接着する工程を示す図である。
【図１５】第２の従来例における積層構造体の製造工程を示し、（ａ）は酸化膜パターン層の形成工程、（ｂ）は酸化膜パターン層をマスクとした断面パターン部材のエッチング工程、（ｃ）は断面パターン部材を形成したドナー基板の形成工程である。
【符号の説明】
１１，３１，４１シリコンウエハ基板
１２，４２離型層
１３Ａｌ薄膜
１３−１，１３−２断面パターン部材
１３−１ａ，４５−１ａ，４５−２ａ断面パターン部材の表面
１５，３７，４６ドナー基板
２１真空槽
２２ＸＹθステージ
２３Ｚステージ
２４ターゲット基板
２４ａターゲット基板の表面
２５ＦＡＢ源
２６ＦＡＢ
２７，５１，５２積層構造体
３２−１，３２−２熱酸化膜
３３支持基板
３４接着層
３５板状部材
３６酸化膜
３５−１，３５−２断面パターン部材
３６−１，３６−２酸化膜パターン層
４３，４３−１，４３−２導電層
４３−１ａ導電層の表面
４４−１，４４−２，４４−３レジストパターン層
４５−１，４５−２断面パターン部材[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a laminated structure and a laminated structure for producing a micro optical component, a micro mechanical component, or a micro structure such as a mold for forming the micro optical component or the micro mechanical component manufactured by the additive manufacturing method. The present invention relates to a method for manufacturing a laminated structure having a thickness of several hundred microns or more and a laminated structure.
[0002]
[Prior art]
The additive manufacturing method has been rapidly spreading in recent years as a method of forming a complicated-shaped three-dimensional object designed by a computer with a short delivery time. A three-dimensional object created by the additive manufacturing method is used as a part model (prototype) for various apparatuses to check the quality of the operation and shape of the part. The size of the parts to which this method is applied was many relatively large parts of several centimeters or more. However, this method is also used for the production of micro structures such as micro optical parts and micro machine parts formed by precision processing. There is a demand to apply the method.
[0003]
With reference to FIGS. 9-13, the manufacturing method of the laminated structure by the 1st prior art example to which the above additive manufacturing methods are applied is demonstrated.
[0004]
As shown in FIG. 9A, a silicon wafer substrate 11 is prepared, a release layer 12 made of polyimide is formed, and subsequently, an Al thin film 13 which is a constituent material of the laminated structure is sputtered or vacuum deposited. To form a 0.5 μm film. The release layer 12 serves to keep the adhesive force with the Al thin film 13 properly.
[0005]
As shown in FIG. 9B, the Al thin film 13 is collectively patterned into a cross-sectional shape of the laminated structure by photolithography to form a plurality of cross-sectional pattern members 13-1 and 13-2. The entire substrate on which the cross-sectional pattern members 13-1 and 13-2 are formed is referred to as a donor substrate 15.
[0006]
As shown in FIG. 10, the donor substrate 15 is fixed on the XYθ stage 22 in the vacuum chamber 21. A target substrate 24 on which the cross-sectional pattern members 13-1 and 13-2 are stacked is fixed to the Z stage 23 above the XYθ stage 22. Then, after evacuating the inside of the vacuum chamber 21, an FAB (Fast Atom Beam) 26 made of an Ar neutral beam is applied to the surface 24 a of the target substrate 24 and the surface 13-1 a of the cross-sectional pattern member 13-1 from the FAB source 25. Irradiate to clean the surface of the target substrate 24 and the cross-sectional pattern member 13-1.
[0007]
As shown in FIG. 11, the Z stage 23 is lowered, the surface 24a of the target substrate 24 is brought into contact with one of the cross-sectional pattern members 13-1, and the load is 50 kgf / cm. ² Is applied and pressed for 5 minutes, the target substrate 24 and the cross-sectional pattern member 13-1 are firmly bonded. In addition, the joining strength is 50-100 Mpa.
[0008]
As shown in FIG. 12, when the Z stage 23 is raised, the cross-sectional pattern member 13-1 is transferred from the donor substrate 15 to the target substrate 24. This is because the bonding force between the cross-sectional pattern member 13-1 and the target substrate 24 is greater than the adhesion between the cross-sectional pattern member 13-1 on the donor substrate 15 and the release layer 12 below. .
[0009]
As shown in FIG. 13, the steps of FIGS. 10 to 12 are repeated to transfer another cross-sectional pattern member 13-2 to the target substrate 24 to form a laminated structure 27. Finally, the laminated structure 27 is transferred to the target substrate. It removes from 24 (refer patent document 1).
[0010]
With reference to FIG. 14 and FIG. 15, the manufacturing method of the laminated structure by the 2nd prior art example is demonstrated.
[0011]
As shown in FIG. 14A, a support substrate 33 having thermal oxide films 32-1 and 32-2 formed on the upper and lower surfaces of a silicon wafer substrate 31 is prepared. As the support substrate 33, a substrate having a flatness of about several microns is used in consideration of the flatness.
[0012]
As shown in FIG. 14B, after an adhesion enhancing agent is applied to the upper surface of the thermal oxide film 32-1 of the support substrate 33, an adhesive layer 34 is formed by spin-coating a photoresist.
By applying the adhesion reinforcing agent, the adhesion between the support substrate 33 and the adhesive layer 34 is larger than the adhesion between the adhesive layer 34 and the plate-like member 35 shown in FIG. It is trying to become.
[0013]
As shown in FIG. 14 (c), a plate-like member 35 is prepared in which both surfaces are mirror-polished, are made of a silicon wafer having a flatness of about several microns and a thickness of 500 microns, and an oxide film 36 is formed only on the upper surface. Then, the plate-like member 35 is attached before the adhesive layer 34 dries, and then, the two support substrates 33 and the plate-like member 35 are bonded by baking at 150 ° C. for 30 minutes.
[0014]
As shown in FIG. 15A, the oxide film 36 on the surface of the plate-like member 35 is collectively patterned into each cross-sectional shape of the finally manufactured structure by a normal photolithography method, and the oxide film Pattern layers 36-1 and 36-2 are obtained. Etching is performed with buffered hydrofluoric acid using a resist pattern (not shown) as a mask.
[0015]
As shown in FIG. 15B, the entire substrate is introduced into an inductive coupled plasma (ICP) etching apparatus (not shown), and the oxide film pattern layers 36-1 and 36-2 are used as masks. Etching is performed so that the shaped member 35 penetrates to the upper surface position of the support substrate 33 to obtain cross-sectional pattern members 35-1 and 35-2.
[0016]
As shown in FIG. 15C, the oxide film pattern layers 36-1 and 36-2 are etched with buffered hydrofluoric acid to form the cross-sectional pattern members 35-1 and 35-2 of the structure. A substrate 37 is obtained.
[0017]
Next, similarly to FIGS. 10 to 13 described in the first conventional example, a plurality of cross-sectional pattern members 35-1 and 35-2 are transferred to the target substrate 24 to form a laminated structure, and finally laminated. The structure is removed from the target substrate 24. In the second conventional example, instead of depositing the Al thin film 13 to be the cross-sectional pattern members 13-1 and 13-2 as in the first conventional example, the cross-sectional pattern members 35-1 and 35-2 Since the thick plate-like member 35 is attached to the support substrate 33, the thick cross-sectional pattern members 35-1 and 35-2 can be formed in a short time. Further, since the cross-sectional pattern members 35-1 and 35-2 are also thick, the number of stacked layers can be reduced. Therefore, a laminated structure can be manufactured in a short time (see Patent Document 2).
[0018]
[Patent Document 1]
Japanese Patent No. 3161362
[Patent Document 2]
Japanese Patent Laid-Open No. 2002-18798
[0019]
[Problems to be solved by the invention]
However, in the conventional manufacturing method of the laminated structure according to Patent Document 1, the cross-sectional pattern members 13-1 and 13-2, which are thin films having a thickness of 0.5 μm, are stacked, and the stacking height is several hundred μm to several mm. Since the structure 27 is manufactured, the number of stacked layers is extremely increased, and the manufacturing time is increased. In order to reduce the number of stacked layers, the thickness of the thin film may be increased from several tens of μm to several hundreds of μm. However, since the deposition rate of the sputtering method or vacuum deposition method is as slow as about 0.05 to 0.1 μm / min, It takes time to deposit a thin film. As described above, there is a problem that it takes a lot of time to deposit or laminate a thin film.
[0020]
On the other hand, in the manufacturing method of the laminated structure of Patent Document 2, it is necessary to set the pressing force when the plate-like member 35 is attached to the support substrate 33 to an appropriate level. The adhesive layer 34 protrudes from the gap between the two and disappears. On the other hand, if the pressing force is small, the plate-like member 35 is not securely adhered to the adhesive layer 34 and the adhesive force is reduced. The cross-sectional pattern members 35-1 and 35-2 are peeled off from the support substrate 33 during the patterning process at the portion where the adhesive layer 34 is not present or the portion where the adhesive force is reduced. In order to prevent the cross-sectional pattern members 35-1 and 35-2 from being peeled off, the pressing force may be appropriate. However, since the margin is small, it is difficult to obtain an appropriate pressing force. Therefore, it is difficult to form the cross-sectional pattern members 35-1 and 35-2 with a high yield, and there is a problem in that the yield of the laminated structure to be manufactured decreases.
[0021]
The present invention has been made in view of the above points, and provides a manufacturing method of a laminated structure and a laminated structure capable of producing a laminated structure having a height of several hundred μm or more with a high yield in a short time. The purpose is to do.
[0022]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a donor substrate on which a plurality of cross-sectional pattern members corresponding to the cross-sectional pattern of the structure is formed, and disposes the target substrate opposite to the donor substrate. In the method for manufacturing a laminated structure in which the laminated structure formed by laminating the cross-sectional pattern members and joining them is formed on the target substrate by repeating the process of aligning and pressing the cross-sectional pattern members and then separating them. Preparation of the donor substrate includes a release layer on the donor substrate and Consists of two or more layers A first step of sequentially forming a conductive layer and forming an inverted pattern layer on the conductive layer by inverting the cross-sectional pattern of the structure; and a space portion corresponding to the cross-sectional pattern of the structure of the inverted pattern layer. A second step of forming the plurality of cross-sectional pattern members by plating and a third step of removing the reversal pattern layer; Provided is a method for producing a laminated structure, which is performed by directly contacting the surfaces.
[0023]
According to this method, since the cross-sectional pattern member is formed by plating with a high deposition rate, a thick cross-sectional pattern member can be formed in a short time.
[0024]
In order to achieve the above object, the present invention provides a cleaning of the layer made of the soft metal, which is laminated via a layer made of a soft metal between each of the plurality of cross-sectional pattern members corresponding to the cross-sectional pattern of the structure. The bonded surface and the cleaned bonded surface of the cross-sectional pattern member are directly contacted and bonded. The layer made of the soft metal is composed of two or more layers. A laminated structure is provided.
[0025]
According to this configuration, the cross-sectional pattern member can be formed by plating using a layer made of a soft metal as an electrode. Since the layer made of a soft metal is plastically deformed when the cross-sectional pattern members are pressed together, the adhesion between the cross-sectional pattern members is improved and the bonding force is increased.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
1A to 1D show a manufacturing process of a laminated structure according to the first embodiment of the present invention. The difference between this embodiment and the prior art is a method for manufacturing a donor substrate.
[0027]
As shown in FIG. 1A, a release layer 42 capable of controlling the adhesion with a cross-sectional pattern member to be described later within an appropriate range is formed on a silicon wafer substrate 41, and plating to be described later is formed thereon. A conductive layer 43 for processing is formed.
[0028]
As shown in FIG. 1B, thick resist pattern layers 44-1, 44-2, and 44-3 having a film thickness of several tens to several hundreds of microns are formed by photolithography. The resist pattern layers 44-1, 44-2, and 44-3 have shapes obtained by inverting the cross-sectional pattern of the laminated structure.
[0029]
As shown in FIG. 1C, a structure is formed between the resist pattern layers 44-1, 44-2, and 44-3 by plating that can form a thick film in a short time using the conductive layer 43 as an electrode. The material is embedded to form cross-sectional pattern members 45-1 and 45-2. The deposition speed in the plating process is several μm / min, which is several tens of times faster than that of sputtering.
[0030]
As shown in FIG. 1D, the resist pattern layers 44-1, 44-2, 44-3 are removed, and the conductive layer 43 is formed using the cross-sectional pattern members 45-1, 45-2 of the laminated structure as a mask. , 43-1 and 43-2 are etched. Thereby, the donor substrate 46 is completed.
[0031]
As shown in FIG. 2, the donor substrate 46 is fixed on the XYθ stage 22 in the vacuum chamber 21, and the target substrate 24 on which the cross-sectional pattern members 45-1 and 45-2 are stacked is fixed on the Z stage 23. The surfaces 24a and 45-1a of the target substrate 24 and the donor substrate 46 are irradiated with the FAB 26 from the FAB source 25 to clean both surfaces 24a and 45-1a.
[0032]
As shown in FIG. 3, the Z stage 23 is lowered to bring the target substrate 24 and the donor substrate 46 into contact with each other, and after applying a load, the Z stage 23 is raised.
[0033]
As shown in FIG. 4, the conductive layer 43-1 is transferred to the target substrate 24 together with the cross-sectional pattern member 45-1. This is because the release layer 42 is in contact with the conductive layer 43-1, and the adhesion between the release layer 42 and the conductive layer 43-1 is the bonding force between the target substrate 24 and the cross-sectional pattern member 45-1. This is because the adhesive strength between the cross-sectional pattern member 45-1 and the conductive layer 43-1 is weaker.
[0034]
As shown in FIG. 5, the XYθ stage 22 is moved to align the cross-sectional pattern member 45-2 with the conductive layer 43-1 in close contact with the cross-sectional pattern member 45-1 transferred to the target substrate 24. After that, the surfaces 43-1a and 45-2a of both 43-1 and 45-2 are irradiated with the FAB 26 to clean the surfaces 43-1a and 45-2a. After that, as shown in FIG. 3, the Z stage 23 is lowered to bring the both 43-1 and 45-2 into contact, and after applying a load, the Z stage 23 is raised.
[0035]
As shown in FIG. 6, the conductive layer 43-2 is transferred to the conductive layer 43-1 along with the cross-sectional pattern member 45-2. Thus, the laminated structure 51 is manufactured by repeatedly transferring and laminating the cross-sectional pattern members.
[0036]
As described above, according to the first embodiment, since the cross-sectional pattern members 45-1 and 45-2 are formed by plating with a high deposition rate, the thick cross-sectional pattern members 45-1 and 45-2 are formed. Can be formed in a short time. For this reason, the lamination | stacking number of the cross-section pattern members 45-1 and 45-2 can also be reduced, and the lamination | stacking structure body 51 whose height is several hundred micrometers or more can be manufactured in a short time.
[0037]
Further, as shown in FIG. 14, the cross-sectional pattern members 45-1 and 45-2 are formed on the release layer 42 without attaching the support substrate 33 and the plate-like member 35. The adhesive force between the release layer 42 and the cross-sectional pattern members 45-1 and 45-2 can be appropriately and reliably maintained, and the cross-sectional pattern members 45-1 and 45-2 are peeled off from the substrate during the patterning process. There is no end to it. Thereby, the yield can be improved. Therefore, the laminated structure 51 having a height of several hundred μm or more can be manufactured in a short time and with a high yield.
[0038]
The first embodiment can be variously modified as follows.
[0039]
For example, in the process shown in FIG. 1D, the exposed conductive layer 43 is removed. However, the exposed conductive layer 43 is not necessarily removed. However, the removal is preferable for the following reason. Since the conductive layer 43 is in contact with the release layer 42, peeling occurs when transferring the cross-sectional pattern members 45-1 and 45-2 at the interface between the conductive layer 43 and the release layer 42. is there.
[0040]
Further, as shown in FIG. 4, the conductive layer 43-1 is also transferred together with the cross-sectional pattern member 45-1 by the peeling. At this time, the adhesive force between the conductive layer 43-1 and the release layer 42 becomes lower as the area where both 43-1 and 42 are in contact is smaller. Therefore, it is preferable to remove the excess conductive layer 43 by etching as shown in FIG. The conductive layers 43-1 and 43-2 are selectively removed by using the cross-sectional pattern members 45-1 and 45-2 as a mask, but they are not necessarily selective, and the cross-sectional pattern members are etched simultaneously. Also good. When the cross-sectional pattern member is etched, it is preferable that the cross-sectional pattern member is previously formed by plating so as to be thicker by the etching amount of the cross-sectional pattern member so as to finally have a predetermined thickness.
[0041]
Further, the conductive layer 43 may be any material having conductivity, and may have two or more layers as necessary. The selectivity of the plating material is expanded by making the upper layer (cross-sectional pattern member side) Au, and the conductive layer and the release layer are made by making the lower layer (release layer side) aluminum or aluminum alloy and the release layer polyimide. The most suitable adhesion is. Moreover, it is preferable to comprise with soft metal materials, such as pure Al, an Al-Cu alloy, and Au. The reason for this will be described next.
[0042]
As shown in FIG. 4, since the conductive layer 43-1 is transferred together with the cross-sectional pattern member 45-1, the conductive layer 43-1 is bonded to the next cross-sectional pattern member 45-2. The joint surface of the cross-sectional pattern member 45-2 has unevenness corresponding to the surface roughness, but when the conductive layer 43-1 is softer, the conductive layer 43-1 is plastically deformed. Since the unevenness of the joint surface is filled to increase the contact area and the joint strength is increased, the cross-sectional pattern member 45-2 is easily transferred. Accordingly, the conductive layer 43 is preferably soft. The method for forming the conductive layer may be any thin film forming method such as plating or sputtering, and is appropriately selected depending on the configuration of the conductive layer. For example, when the upper layer of the conductive layer is made of Au and the lower layer is made of aluminum as described above, it is difficult to form Au on the aluminum by plating, so that Au can be formed by sputtering. preferable.
[0043]
It is also preferable to form a soft material such as pure Al, Al—Cu alloy, Au, etc. on the cross-sectional pattern members 45-1 and 45-2 (surface) serving as bonding surfaces because the bonding strength is also increased. . However, since the soft conductive layer 43 is included in the laminated structure 51 and the rigidity is lowered, it is not preferable when a laminated structure that requires high rigidity is manufactured.
[0044]
Next, the manufacturing method of the laminated structure which concerns on 2nd Embodiment which manufactures the laminated structure which requires such high rigidity is demonstrated.
[0045]
After the steps shown in FIGS. 1A and 1B, in the plating process shown in FIG. 1C, the cross-sectional pattern member is interposed between the resist pattern layers 44-1, 44-2, 44-3. After forming 45-1 and 45-2, the cross-sectional pattern member 45 is polished by polishing the upper surfaces of the resist pattern layers 44-1, 44-2 and 44-3 and the cross-sectional pattern members 45-1 and 45-2. The unevenness of the bonding surfaces of −1 and 45-2 is eliminated and a smooth surface is obtained. Then, as shown in FIG. 1D, the resist pattern layers 44-1, 44-2, 44-3 are removed, and the conductive layer 43 is formed using the cross-sectional pattern members 45-1, 45-2 as a mask. Etching is performed as indicated by 43-1 and 43-2 to complete the donor substrate 46.
[0046]
However, the process of making the joint surfaces of the cross-sectional pattern members 45-1 and 45-2 smooth is performed after removing the resist pattern layers 44-1, 44-2, and 44-3 shown in FIG. Also good.
[0047]
As shown in FIG. 2, the donor substrate 46 is fixed on the XYθ stage 22 in the vacuum chamber 21, and the target substrate 24 is fixed on the Z stage 23, and the target substrate 24 and the donor substrate 46 are irradiated by irradiation with the FAB 26. The surfaces 24a and 45-1a are cleaned.
[0048]
As shown in FIG. 3, the Z stage 23 is lowered to bring them into contact with each other 24 and 46, and after applying a load, the Z stage 23 is raised, and as shown in FIG. The conductive layer 43-1 is transferred together with the cross-sectional pattern member 45-1.
[0049]
As shown in FIG. 7, the XYθ stage 22 is moved so that the conductive layer 43-1 (see FIG. 3) in close contact with the cross-sectional pattern member 45-1 transferred to the target substrate 24, and the cross-sectional pattern member 45-2. After the alignment, the surface is cleaned before the next cross-sectional pattern member 45-2 is joined. At this time, the conductive layer 43-1 is etched by irradiation with the FAB 26 to remove the conductive layer 43-1. Thereafter, the Z stage 23 is lowered to bring the cross-sectional pattern member 45-1 on the target substrate 24 into contact with the cross-sectional pattern member 45-2 on the donor substrate 46, and after applying a load, the Z stage 23 is raised. Let
[0050]
As shown in FIG. 8, another cross-sectional pattern member 45-2 is transferred to the cross-sectional pattern member 45-1.
[0051]
According to the second embodiment, a cross-sectional pattern member from which the conductive layer 43 has been removed is repeatedly transferred and stacked, whereby a highly rigid stacked structure without the conductive layer 43 interposed therebetween can be manufactured. . Since the upper surfaces of the cross-sectional pattern members 45-1 and 45-2 are smooth surfaces, the bonding strength between the cross-sectional pattern members is increased.
[0052]
However, the conductive layer so that the adhesion between the conductive layers 43-1 and 43-2 and the release layer 42 is most appropriate so that the cross-sectional pattern members 45-1 and 45-2 are securely bonded to each other. Desirably, 43 is pure Al or an Al—Cu alloy, and the release layer 42 is polyimide.
[0053]
The reverse pattern shown in FIG. 1B is preferably formed by patterning a thick film resist by a lithography method so that the shape accuracy is good. As such a patterning method, there is a method of patterning using a thick film resist that is sensitive to light or X-rays, but it is more preferable to pattern using a thick film resist that is sensitive to light, which is lower in cost.
[0054]
【Example】
Hereinafter, the process of actually manufacturing the laminated structure 51 by the manufacturing method of the laminated structure having such effects will be described with reference to FIGS.
[0055]
As shown in FIG. 1A, a silicon wafer substrate 41 was prepared, polyimide was applied to the surface of the substrate 41 by spin coating, and baked at a maximum temperature of 350 ° C. to form a release layer 42. Subsequently, a conductive layer 43 was formed by depositing Au having a thickness of 0.5 μm by sputtering.
[0056]
As shown in FIG. 1B, after forming a thick film resist having a thickness of 50 μm on the conductive layer 43, exposure / development is performed to form a resist pattern layer 44 having a shape obtained by inverting the cross-sectional pattern of the laminated structure. -1, 44-2, 44-3 were formed.
[0057]
As shown in FIG. 1C, plating is performed to form Cu between the resist pattern layers 44-1, 44-2, 44-3 until the film thickness reaches 50 μm, thereby obtaining a cross-sectional pattern member 45-. 1,45-2 was formed. The deposition rate of Cu was 2 μm / min. The cross-sectional pattern members 45-1 and 45-2 may be Ni.
[0058]
As shown in FIG. 1D, after the resist pattern layers 44-1, 44-2, 44-3 are removed by ashing, the conductive layer 43 is formed using the cross-sectional pattern members 45-1, 45-2 as a mask. Was selectively etched to manufacture a donor substrate 46.
[0059]
As shown in FIG. 2, the donor substrate 46 is fixed on the XYθ stage 22 in the vacuum chamber 21, the target substrate 24 is fixed on the Z stage 23, and the interior of the chamber is 5 × 10. ^-Five It was evacuated to Pa. Subsequently, the surface 24a, 45-1a of the target substrate 24 and the cross-sectional pattern member 45-1 was irradiated with FAB 26 from the FAB source 25 to perform surface activation treatment. The FAB processing conditions were an FAB voltage of 1.5 kV, an FAB current of 15 mA, and a processing time of 5 minutes.
[0060]
As shown in FIG. 3, the Z stage 23 is lowered, the target substrate 24 and the cross-sectional pattern member 45-1 are brought into contact with each other, and the load is 50 kgf / cm. ² And pressed for 5 minutes. As a result, the target substrate 24 and the cross-sectional pattern member 45-1 were firmly bonded. In addition, the joining strength is 50-100 Mpa.
[0061]
As shown in FIG. 4, when the Z stage 23 is raised, the cross-sectional pattern member 45-1 is transferred from the donor substrate 46 to the target substrate 24.
[0062]
As shown in FIG. 5, the XYθ stage 22 is moved to align the cross-sectional pattern member 45-2 with the conductive layer 43-1 in close contact with the cross-sectional pattern member 45-1 transferred to the target substrate 24. After that, the surfaces 43-1a and 45-2a of both 43-1 and 45-2 were irradiated with FAB26 to clean the surfaces 43-1a and 45-2a. Thereafter, as shown in FIG. 3, the Z stage 23 was lowered to bring both the 43-1 and 45-2 into contact, and after applying a load, the Z stage 23 was raised.
[0063]
As shown in FIG. 6, the conductive layer 43-2 is transferred to the conductive layer 43-1 along with the cross-sectional pattern member 45-2. Thus, the laminated structure 51 was manufactured by repeatedly transferring and laminating the cross-sectional pattern members. As described above, according to this example, the laminated structure 51 having a height of several hundred μm or more could be manufactured in a short time with a high yield.
[0064]
【The invention's effect】
As described above, according to the method for manufacturing a laminated structure of the present invention, since the cross-sectional pattern member is formed by plating with a high deposition rate, a thick cross-sectional pattern member can be formed in a short time. . For this reason, the number of laminated cross-sectional pattern members can be reduced, and a laminated structure having a height of several hundred μm or more can be manufactured in a short time. In addition, since the cross-sectional pattern member is formed on the release layer without attaching the support substrate and the plate-like member as in the prior art, the adhesive force between the release layer and the cross-sectional pattern member is appropriately and The cross-sectional pattern member is not peeled off from the substrate during the patterning process. Thereby, the yield can be improved.
[0065]
According to the laminated structure of the present invention, a multi-sectional pattern member can be formed by plating with a high deposition rate as a layer electrode made of a soft metal, so that a laminated structure having a height of several hundred μm or more can be formed in a short time. It can be manufactured with good yield.
[Brief description of the drawings]
FIGS. 1A and 1B show a manufacturing process of a multilayer structure according to a first embodiment of the present invention, in which FIG. 1A shows a process for forming a release layer and a conductive layer on a silicon wafer substrate, and FIG. (C) is a plating process for forming a cross-sectional pattern member between the resist pattern layers, and (d) is a donor substrate forming the cross-sectional pattern member. It is a figure which shows the etching process for.
FIG. 2 is a diagram illustrating a process of cleaning the surfaces of a donor substrate and a target substrate in a vacuum chamber.
FIG. 3 is a diagram showing a process of applying a load by a target substrate to a donor substrate in a vacuum chamber.
FIG. 4 is a diagram illustrating a process of transferring a conductive layer together with a cross-sectional pattern member to a target substrate in a vacuum chamber.
FIG. 5 shows a process of moving the XYθ stage in the vacuum chamber to align the cross-sectional pattern member with the conductive layer in close contact with the cross-sectional pattern member that has been transferred to the target substrate, and to clean the surfaces of the two. FIG.
FIG. 6 is a diagram showing a process of transferring a conductive layer together with other cross-sectional pattern members to a conductive layer of a cross-sectional pattern member in a vacuum chamber.
FIG. 7 is a diagram showing a process of removing the conductive layer after transferring the conductive layer together with the cross-sectional pattern member to the target substrate in the vacuum chamber.
FIG. 8 is a diagram showing a process of transferring another cross-sectional pattern member directly to the cross-sectional pattern member of the target substrate in the vacuum chamber.
FIGS. 9A and 9B show a manufacturing process of the laminated structure in the first conventional example, in which FIG. 9A shows a release layer and Al thin film forming process on a silicon wafer substrate, and FIG. 9B shows a donor on which a cross-sectional pattern member is formed. It is a figure which shows the etching process for board | substrate formation.
FIG. 10 is a diagram showing a process of cleaning the surfaces of a donor substrate and a target substrate in a vacuum chamber in the first conventional example.
FIG. 11 is a diagram showing a step of applying a load by a target substrate to a donor substrate in a vacuum chamber in the first conventional example.
FIG. 12 is a diagram showing a process of transferring a cross-sectional pattern member to a target substrate in a vacuum chamber in the first conventional example.
FIG. 13 is a diagram showing a process of transferring another cross-sectional pattern member to the cross-sectional pattern member of the target substrate in the vacuum chamber in the first conventional example.
14A and 14B show a manufacturing process of a laminated structure according to a second conventional example, in which FIG. 14A shows a support substrate forming process in which a thermal oxide film is formed on the upper and lower surfaces of a silicon wafer substrate, and FIG. (C) is a figure which shows the process of adhere | attaching the plate-shaped member in which the oxide film was formed in the surface through the contact bonding layer to the support substrate through the formation process of the contact bonding layer to an oxide film upper surface.
15A and 15B show a manufacturing process of a laminated structure according to a second conventional example, in which FIG. 15A shows an oxide film pattern layer forming process, and FIG. 15B shows a cross-sectional pattern member etching process using the oxide film pattern layer as a mask; (C) is a step of forming a donor substrate on which a cross-sectional pattern member is formed.
[Explanation of symbols]
11, 31, 41 Silicon wafer substrate
12, 42 release layer
13 Al thin film
13-1, 13-2 Cross-sectional pattern member
13-1a, 45-1a, 45-2a Surface of cross-sectional pattern member
15, 37, 46 Donor substrate
21 Vacuum chamber
22 XYθ stage
23 Z stage
24 Target substrate
24a Target substrate surface
25 FAB source
26 FAB
27, 51, 52 Laminated structure
32-1, 32-2 Thermal oxide film
33 Support substrate
34 Adhesive layer
35 Plate member
36 Oxide film
35-1, 35-2 Cross-sectional pattern members
36-1, 36-2 Oxide film pattern layer
43, 43-1, 43-2 conductive layer
43-1a Surface of conductive layer
44-1, 44-2, 44-3 resist pattern layer
45-1, 45-2 Cross-sectional pattern members

Claims

After preparing a donor substrate on which a plurality of cross-sectional pattern members corresponding to the cross-sectional pattern of the structure are formed, disposing a target substrate opposite to the donor substrate, aligning the target substrate with the cross-sectional pattern member, and pressing the target substrate In the method for manufacturing a laminated structure in which the laminated structure formed by laminating the cross-sectional pattern members and bonded thereto is formed on the target substrate by repeating the separation process.
Preparation of the donor substrate is:
A first step of sequentially forming a release layer and a conductive layer composed of two or more layers on the donor substrate, and forming an inverted pattern layer on the conductive layer by inverting the cross-sectional pattern of the structure;
A second step of forming the plurality of cross-sectional pattern members by plating in a space portion corresponding to the cross-sectional pattern of the structure of the reverse pattern layer;
A third step of removing the reverse pattern layer;
The cross-sectional pattern member is joined by cleaning the joint surface and bringing the cleaned joint surface into direct contact with each other.

2. The method for manufacturing a laminated structure according to claim 1, wherein in the first step, the reverse pattern layer is formed by patterning a thick film resist by a photolithography method.

2. The method for manufacturing a laminated structure according to claim 1, wherein in the third step, the exposed conductive layer is removed using the cross-sectional pattern member as a mask. 3.

The method for manufacturing a laminated structure according to claim 1, wherein the cross-sectional pattern member is bonded to the conductive layer together with the cross-sectional pattern member on the target substrate.

The method for producing a laminated structure according to claim 1, wherein the release layer is made of polyimide, and the conductive layer in contact with the release layer is made of aluminum or an aluminum alloy.

The method for manufacturing a laminated structure according to claim 1, wherein the conductive layer is made of a soft metal.

The method for producing a laminated structure according to claim 6, wherein the soft metal is any one of aluminum, an aluminum alloy, and gold.

2. The method for manufacturing a microstructure according to claim 1 , wherein an upper layer of the conductive layer is made of gold and a lower layer is made of aluminum or an aluminum alloy.

After preparing a donor substrate on which a plurality of cross-sectional pattern members corresponding to the cross-sectional pattern of the structure are formed, disposing a target substrate opposite to the donor substrate, aligning the target substrate with the cross-sectional pattern member, and pressing the target substrate In the method for manufacturing a laminated structure in which the laminated structure formed by laminating the cross-sectional pattern members and bonded thereto is formed on the target substrate by repeating the separation process.
Preparation of the donor substrate is:
A first step of sequentially forming a release layer and a conductive layer on the donor substrate, and forming an inverted pattern layer on the conductive layer by reversing a cross-sectional pattern of the structure;
A second step of forming the plurality of cross-sectional pattern members by plating in a space portion corresponding to the cross-sectional pattern of the structure of the reverse pattern layer;
A third step of removing the reverse pattern layer;
The second or third step includes a fourth step of polishing the surface of the cross-sectional pattern member to form a smooth surface,
The cross-sectional pattern member is joined by cleaning the joint surface, bringing the cleaned joint surface into direct contact, and the cross-sectional pattern member joined on the target substrate being the smooth surface. If it is, the conductive layer joined together with the cross-sectional pattern member having the smooth surface is removed, and the process of joining the conductive layer together with the next cross-sectional pattern member to the cross-sectional pattern member from which the conductive layer has been removed is repeated. A method for producing a laminated structure, comprising producing a laminated structure.

The plurality of cross-sectional pattern members corresponding to the cross-sectional pattern of the structure are laminated via a layer made of a soft metal between each of the cross-sectional pattern members, and the cleaned joint surface of the layer made of the soft metal and the cleaning of the cross-sectional pattern member A laminated structure characterized in that the layer made of the soft metal is composed of two or more layers, which are joined in direct contact with the joined surface.

The laminated structure according to claim 10 , wherein the soft metal is any one of aluminum, an aluminum alloy, and gold.