JP2004004745A - Microstructure forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a microstructure forming method for improving the controllability of etching in the case of fine-working using isotropic etching, and also, attaining uniform working even in a large-sized substrate. <P>SOLUTION: As for the microstructure forming method, a body to be etched on the surface of which a mask having prescribed openings is disposed, is etched through the openings by using etching liquid, so as to form recesses on the surface of the body to be etched, and insoluble matter is generated by the reaction of the material contained in the body to be etched and the etching liquid, and then, etching is stopped by the insoluble matter accumulated on the exposed surface of the body to be etched. <P>COPYRIGHT: (C)2004,JPO

Description

【０１２４】
表１に示す結果から、開口部直径の大きさが開口部のピッチの１／１０以上１／３以下の範囲において、本発明の目的が達成されることが明らかである。
【０１２５】
また、表１に示す○印で得られたマイクロレンズの直径は、隣接するレンズ同士が接する状態の大きさから、隣接するレンズのエッチング領域が重なるがエッチング用マスクの剥離が生じない状態までの大きさであり、表１に示した開口部ピッチの１．０〜１．４倍の大きさであった。この結果から、表１を用いることにより、作製するマイクロレンズの直径寸法から開口部のピッチと開口部の直径を決めることができる。例えば、レンズの直径が３０〜４０μｍのマイクロレンズアレイを作製するには、表１から、開口部のピッチを３０μｍにした場合、開口部の直径を３〜１０μｍにすればよいことがわかる。
【０１２６】
また、開口部の形状が円形の替わりに正方形である場合についても、数多くの実験を実施したので、その結果について説明する。
【０１２７】
表２は、正方形の一辺の長さである開口部辺長と開口部のピッチとを変えてエッチング後の状況をまとめたものである。なお、表２に示される各印の意味については上記表１と同様である。
【０１２８】
【表２】

【０１２９】
表２に示す結果から、開口部辺長が開口部のピッチの１／１０以上１／３以下の範囲において、本発明の目的が達成されることが明らかである。このように、本発明は開口部の形状には大きく依存しないことが判明した。そのため、上記エッチング用マスクの開口部３ａの形状は、本実施形態では円形としているが、方形、楕円形、その他の形状でもよい。
【０１３０】
次に、エッチャント濃度に対する依存性について検討するためにフッ酸水溶液の濃度を変えてエッチングを行ったので、その結果について説明する。
【０１３１】
表３は、開口部のピッチ３０μｍ、開口部直径３μｍのエッチング用マスクを設けた場合について、フッ酸水溶液の濃度を５％、１０％、２０％、３０％とした場合のエッチング時間をまとめたものである。なお、このエッチング時間は、エッチングの進行が不溶物５の影響により自動的に停止するまでの時間を意味する。
【０１３２】
【表３】

【０１３３】
表３に示す結果から、フッ酸濃度が高いほどエッチングの進行が停止するまでの時間が短くなっている。また、それぞれのエッチング条件により得られたレンズ形状について観察を行ったところ、どの条件でもほぼ同様の形状が得られていることが判明した。これは、本発明がエッチャント４の濃度には大きく依存しないことを示唆している。すなわち、エッチャント濃度が多少変化し、これによりエッチングが停止するまでの時間が変動しても、エッチングが不溶物５により自動的に停止するため、オーバーエッチングが発生することはない。また、予め所定のエッチング時間より長めの時間を設定しておくことで、エッチング不足を防止することも可能である。
【０１３４】
なお、基板１に含有される、エッチャント４に溶解しない物質である不純物の濃度に関しては、エッチャント濃度が同じでも、不純物濃度が高い場合にはエッチングの進行の停止が早くなり、不純物濃度が低い場合には不溶物の生成が不十分となるためエッチングの進行の停止が遅くなる傾向がある。そのため、形成されるレンズの直径は、基板１の不純物濃度による影響を受けることとなる。このことから、基板１に含有される酸化アルミニウム等の不純物の濃度は基板内および基板間で一定である方がよい。
【０１３５】
次に、エッチャント４の温度に対する依存性について検討するためにフッ酸水溶液の温度を変えてエッチングを行ったので、その結果について説明する。
【０１３６】
表４は、エッチャント中のフッ酸濃度を１０％に固定し、エッチャント温度を変えてエッチング時間を調べた結果をまとめたものである。なお、このエッチング時間は、上記表３と同様にエッチングの進行が停止するまでの時間を意味する。
【０１３７】
【表４】

【０１３８】
表４に示す結果から、エッチャントの温度が高いほどエッチングの進行が停止するまでの時間が短くなっている。また、それぞれのエッチング条件により得られたレンズ形状について観察を行ったところ、どの条件でも同様の形状が得られていることが判明した。これは、本発明がエッチャントの温度にも大きく依存せず、厳密な温度管理が不要であることを意味する。また、濃度を変えた場合と同様に、厳密な時間管理が不要で、エッチング不足およびオーバーエッチングを防止することも可能である。
【０１３９】
次に、エッチング用マスクについての検討結果を以下に説明する。
【０１４０】
エッチング用マスクの材質については、エッチャント４により変質が発生しにくいこと、および基板１との密着性が高いことが好ましい。密着性が低い場合には、基板１とエッチング用マスクとの界面からエッチングが進行し、エッチングムラの一因となるためである。本実施形態のようなクロム層などの金属膜２は、フッ酸系エッチング液に対して変質しにくく、基板１との密着性がよい。
【０１４１】
次に、エッチング用マスクの金属膜２に用いたクロム層の厚みについて検討した結果を以下に説明する。
【０１４２】
表５はクロム層の厚みを１０ｎｍから５００ｎｍの間で変化させた場合のエッチング結果をまとめたものである。
【０１４３】
【表５】

【０１４４】
表５に示すように、クロム層の厚みが１０ｎｍ以下の場合と５００ｎｍ以上の場合にクロム層がマスクとして使用できない状態になり、その理由は以下の通りである。
【０１４５】
クロム層の厚みが１０ｎｍ以下の場合にはクロム層にピンホールが発生し、エッチング用マスクとしての機能が十分に発揮できないため、エッチング用マスクの剥離が発生して、良好なエッチング状態を得ることができなかった。また、クロム層の厚みが５００ｎｍ以上の場合には多数のクラックが発生するとともに、エッチングの進行に伴ってクロム層の応力に起因すると考えられる剥離が発生して、良好なエッチング状態を得ることができなかった。このため、本発明におけるクロム層の厚みは２０ｎｍから３００ｎｍの範囲に設定されることが好ましい。また、クロムのかわりにシリコン、チタン、銀、白金、金などを使用することができるが、クロムの場合と同様な現象が発生するため、上記の厚みの範囲で使用することが好ましい。
【０１４６】
次に、エッチング用マスクのレジスト３の厚みについて検討した結果を以下に説明する。
【０１４７】
表６はレジスト３の厚みを１００ｎｍから６０００ｎｍの間で変化させた場合のエッチング結果をまとめたものである。
【０１４８】
【表６】

【０１４９】
表６に示すように、レジスト３の厚みが１００ｎｍ以下の場合と６０００ｎｍ以上の場合にレジスト３がマスクとして使用できない状態になり、その理由は以下の通りである。
【０１５０】
レジスト３の厚みが１００ｎｍ以下の場合にはエッチングの進行とともにエッチング用マスクの剥離が発生して、良好なエッチング状態を得ることができなかった。また、レジスト３の厚みが６０００ｎｍ以上の場合にも、エッチングの進行とともにエッチング用マスクの剥離が発生して、良好なエッチング状態を得ることができなかった。このため、本発明におけるレジスト３の厚みは２００ｎｍから４０００ｎｍの範囲に設定されることが好ましい。
【０１５１】
なお、本実施形態は、マイクロレンズアレイのみならず、単体のマイクロレンズの形成にも同様に適用することが可能である。
【０１５２】
本実施形態では、上述したように、不溶物５が生成されることで基板１のエッチングが自動的に停止する効果により、エッチングが停止した後に基板１をエッチャント４に浸していてもエッチングが進行しない。そのため、エッチング停止後に基板１をエッチャント４から取り出す時間のマージンを大きく確保できる。
【０１５３】
また、複数枚の基板１を一度に加工する際にも、上記不溶物５の生成が基板間で均一なため、基板間で均一な加工が可能になる。また、一枚の基板１を複数回のエッチング処理で加工する場合にも、上記不溶物５の生成がエッチング処理間で均一なため、エッチング処理間で均一な加工が可能となる。そのため、基板１が大型化しエッチャント濃度やエッチング時間に面内分布が発生しても、基板面内のみならず基板間で均一なレンズパターンを作製することができ、基板面内および基板間における凹部形状の均一性により歩留りが向上し、ウェットエッチングにより低コスト化が可能となる。
【０１５４】
また、発生した不溶物５がエッチング用マスクの支えの役割を果たすため、金属膜２およびレジスト３から構成されるエッチング用マスクの剥離を防止することができ、より均一性の高い加工が可能になる。さらに、無アルカリガラス、低アルカリガラス、ホウ珪酸ガラス、鉛ガラスなどの液晶表示用ガラスは石英ガラス基板やシリコンウェハ基板と比較して安価であり、本実施形態では、これらの液晶表示素子用ガラスを使用することができるため、低コスト化も実現可能である。
【０１５５】
なお、本実施形態によるマイクロレンズアレイ基板１２を液晶表示素子に応用する場合について説明する。
【０１５６】
図２は液晶表示素子の外観を模式的に示す斜視図である。
【０１５７】
図に示すように、液晶表示素子は、マイクロレンズアレイ基板１２上に設けられた調整用ガラス板５１と公知の方法により作製されたＴＦＴ基板５０との間に液晶層５２が挟まれる構成である。
【０１５８】
上記構成の液晶表示素子では、図の下側から照射された光がマイクロレンズアレイ基板１２に設けられたマイクロレンズによりＴＦＴ基板５０の透過部で集光するように構成されているため、光を透過するように液晶分子が配列した部分の輝度が高くなる。また、本実施形態のマイクロレンズアレイ基板１２を用いることにより、表示面内の輝度が均一になる。
【０１５９】
上記液晶表示素子の作製方法について説明する。
【０１６０】
図３乃至図５は液晶表示素子の作製方法を製造工程順に示した断面図である。
【０１６１】
図３（Ａ）に示すように、無アルカリガラスの基板２０１上に金属膜２０２およびレジスト２０３を順に形成し、公知のリソグラフィ工程およびエッチング工程によりレジスト２０３と金属膜２０２に開口部２０３ａを形成する。開口部２０３ａを形成する際、以下に説明する露光位置調整マーカ２０３ｂを形成する。なお、図１では、露光位置調整マーカ２０３ｂを図に示すことを省略した。
【０１６２】
露光位置調整マーカ２０３ｂは基板２０１上の所定の場所に必要な数だけ設けられている。露光位置調整マーカ２０３ｂは、ステッパ露光機による、上記開口部２０３ａを形成するための第１の露光とそれ以降に行う露光の際、ステッパ露光機用マスクであるレチクルやＴＦＴ基板等との相対的な位置決めのために用いられる位置合わせ手段であり、一般的にその精度は１μｍ以下である。なお、工程数は増えるが露光位置調整マーカ２０３ｂを形成した後に、開口部２０３ａを形成してもよい。
【０１６３】
続いて、図３（Ｂ）に示すように、基板２０１をエッチャントに浸す前に、露光位置調整マーカ２０３ｂをエッチャントから保護するための保護材２５３を形成する。この保護材２５３はエッチャントに対する耐性を有するものであればよく、保護材２５３として、特に保護テープやエポキシ系樹脂材料等を好適に用いることが可能である。
【０１６４】
そして、図３（Ｃ）に示すように、基板２０１をエッチャントに浸して、基板２０１のエッチングを行う。このとき、保護材２５３が露光位置調整マーカ２０３ｂの形状変化や剥離を防止する。また、レンズとなる凹部の周囲に柱状パターン２０１ａを有するため、レジスト２０３と金属膜２０２の剥離を防止する。
【０１６５】
その後、図３（Ｄ）に示すように、保護材２５３を剥離し、レジスト２０３と、露光位置調整マーカ２０３ｂ以外の金属膜２０２を剥離する。ここでは、保護材２５３を剥離したが、この後のステッパ露光機によるステッパ露光の際、問題とならなければ特に剥離する必要はない。
【０１６６】
続いて、図３（Ｅ）に示すように、マイクロレンズアレイ基板２１２の凹部形成面に高屈折率接着剤２５４を塗布して透明な調整用ガラス板２５１を貼合する。このとき、マイクロレンズアレイのレンズの焦点距離を調整して、レンズとしての効果が最大となるように調整用ガラス板２５１の厚さを調整する。マイクロレンズアレイ基板２１２に調整用ガラス板２５１を貼り合わせた後に調整用ガラス２５１を薄くして厚さ調整してもよいが、予め厚さ調整した調整用ガラス板２５１をマイクロレンズアレイ基板２１２に貼合してもよい。貼合後に薄くする場合には、エッチング法や機械研磨法を好適に用いることが可能である。このように透明基板として調整用ガラス板２５１を凹部形成面側に貼合することで、凹部に埋め込まれた高屈折率接着剤２５４の形状を維持し、凹部で屈折した光が調整用ラス板２５１を透過可能となる。
【０１６７】
その後、調整用ガラス板２５１上にクロムやアルミニウム等の薄膜を成膜し、その上にレジストを塗布する。そして、重ね合わせ位置調整マーカ２５５および画素遮光部２５６のパターンを形成するためのレチクルに備えたマーカと、露光位置調整マーカ２０３ｂを使用して、レチクルとマイクロレンズアレイ基板２１２を位置決めして、ステッパ露光および現像を行う。続いて、エッチングによりレジストマスクの形状に合わせたパターンを形成するパターニングにより、重ね合わせ位置調整マーカ２５５と画素遮光部２５６を形成する（図３（Ｆ））。
【０１６８】
このように、ステッパ露光時のレチクルとマイクロレンズアレイ基板２１２の位置決めのために露光位置調整マーカ２０３ｂを使用している。そのため、重ね合わせ位置調整マーカ２５５と画素遮光部２５６をより正確に所望の位置に配置できる。この重ね合わせ位置調整マーカ２５５は、液晶表示素子を作製する際に使用するＴＦＴ基板と高精度に重ね合わせるために用いられる。ＴＦＴ基板との重ね合わせを高精度に行い得るため、画素遮光部２５６等の重ね合わせマージンをより小さくでき、開口率がより高くなり、より明るい表示が可能な液晶表示素子を作製可能となる。なお、画素遮光部２５６はＴＦＴ等に光が当たるのを防止するための遮光手段である。
【０１６９】
その後、公知の方法により、調整用ガラス板２５１上に、図に示さない透明電極および配向膜等を形成する。
【０１７０】
なお、上記高屈折率接着剤を用いて貼合する代わりに、形成された凹部に高屈折率材料を埋め込み、調整用ガラス板２５１とほぼ同一の屈折率の接着剤を用いてマイクロレンズアレイ基板２１２と調整用ガラス板２５１を接着してもよい。また、上記高屈折率接着剤および高屈折率材料の屈折率を調整することで、マイクロレンズアレイのレンズの焦点距離を調整することが可能である。
【０１７１】
次に、ＴＦＴ基板とマイクロレンズアレイ基板を重ね合わせる方法について説明する。重ね合わせ方法は大きく分けて二つある。一つめの方法は、ＴＦＴ基板とマイクロレンズアレイ基板を重ね合わせた後に個片に切断する方法であり、二つめの方法は、ＴＦＴ基板とマイクロレンズアレイ基板を個片に切断してから重ね合わせる方法である。
【０１７２】
はじめに、一つめの重ね合わせ方法について説明する。
【０１７３】
図４は一つめの重ね合わせ方法を示す断面模式図である。
【０１７４】
図３（Ｆ）に示したマイクロレンズアレイ基板２１２を用意する（図４（Ａ））。続いて、図４（Ｂ）に示すように、公知の方法により作製されたＴＦＴ基板２５０とマイクロレンズアレイ基板２１２を、重ね合わせ位置調整マーカ２５５とＴＦＴ基板側重ね合わせ位置調整マーカ２５７を使用して位置を合わせ、シール剤２５８で貼り合わせる。このとき、ＴＦＴ基板２５０とマイクロレンズアレイ基板２１２には、液晶を入れるための隙間を設けている。なお、露光位置調整マーカ２０３ｂを形成するときに、重ね合わせ位置調整マーカをマイクロレンズアレイ基板２１２の表面に形成し、この重ね合わせ位置調整マーカをＴＦＴ基板２５０との重ね合わせ時に使用してもよい。
【０１７５】
続いて、図４（Ｃ）に示すように、切断箇所に高圧の水をかける切断方法で、貼り合わせたＴＦＴ基板２５０とマイクロレンズアレイ基板２１２を個片に分離し、貼り合わせた２枚の板の間に液晶を封入して液晶層２５２を形成して液晶表示素子２６０を得る。この切断方法によれば、マイクロレンズアレイ基板２１２と調整用ガラス板２５１が高屈折率接着剤２５４で貼合されているような構造でも、効率よく切断できる。なお、液晶層２５２を、ＴＦＴ基板２５０とマイクロレンズ基板２１２を貼り合わせる際に封入してもよい。
【０１７６】
次に、二つめの重ね合わせ方法について説明する。
【０１７７】
図５は二つめの重ね合わせ方法を示す断面模式図である。
【０１７８】
図５（Ａ）に示すように、マイクロレンズアレイ基板２１２を個片に切断する。個片にしたマイクロレンズアレイ基板２１２ａにも、重ね合わせ位置調整マーカ２５５が形成されている。続いて、図５（Ｂ）に示すように、個片にしたＴＦＴ基板２５０ａと個片にしたマイクロレンズアレイ基板２１２ａを、重ね合わせ位置調整マーカ２５５とＴＦＴ基板側重ね合わせ位置調整マーカ２５７を使用して位置を合わせ、シール剤２５８で貼り合わせる。貼り合わせた２枚の板の間に液晶を封入して液晶層２５２を形成し、液晶表示素子２６０を得る。
【０１７９】
なお、図４および図５では、マイクロレンズアレイ基板２１２の凹部形成面側に調整用ガラス基板２５１を貼り合わせ、調整用ガラス基板２５１とＴＦＴ基板２５０の間に液晶層２５２を形成したが、以下に説明するように、マイクロレンズアレイ基板２１２とＴＦＴ基板２５０の間に液晶層２５２を形成するようにしてもよい。
【０１８０】
図６は液晶表示素子の別の構成例を示す断面図である。
【０１８１】
図５に示した個片にしたマイクロレンズアレイ基板２１２ａの上下方向を逆にし、図６に示すように、個片にしたマイクロレンズアレイ基板２１２ａのレンズが図の上向きで凸形状になるようにしている。図６に示す構造を形成する場合には、レンズの効果が最大となるように個片にしたマイクロレンズアレイ基板２１２ａの厚さを調整している。マイクロレンズアレイ基板２１２の凹部形成面に調整用ガラス２５１を貼り合わせた後にマイクロレンズアレイ基板２１２の厚さを調整してもよいが、予めマイクロレンズアレイ基板２１２の厚さを調整してから調整用ガラス板２５１を貼合してもよい。貼合後に薄くする場合には、エッチング法や機械研磨法を好適に用いることが可能である。
【０１８２】
液晶表示素子のＴＦＴ基板とマイクロレンズアレイ基板は、単位長さあたりの熱膨張係数である線熱膨張係数が比較的近いことが好ましい。これら２枚の基板に線熱膨張係数が大きく異なるものを使用すると、ヒートサイクルでの基板剥離等による信頼性低下と、熱膨張による位置目合わせずれが問題になる。ＴＦＴ基板には、無アルカリガラスまたは石英基板が多く使用される。このとき、ＴＦＴ基板の基板の種類に応じて、マイクロレンズアレイ基板に無アルカリガラスやβ―石英型透明結晶化ガラス等を使用することで、ＴＦＴ基板とマイクロレンズアレイ基板の線熱膨張係数が等しくなり、上記問題の発生が抑制され、信頼性がより向上する。
【０１８３】
次に、作製された液晶表示素子を液晶プロジェクタの液晶ライトバルブとして応用する場合について説明する。
【０１８４】
図７は液晶プロジェクタの一構成例を示す模式図である。
【０１８５】
図に示すように、液晶プロジェクタは、光源１３０と、光源１３０からの光の偏光方向を揃えるとともに光強度を均一にする偏光変換インテグレータ１３２と、光源１３０からの白色光をダイクロイックミラー１３３、１３４により赤色、緑色および青色の３色の光束に分離する色分離光学系と、分離された光束の進行方向を変えるための全反射ミラー１３５〜１３７と、上記３色の光束が色別に照射される３枚の液晶表示素子１３８〜１４０と、これら３枚の液晶表示素子１３８〜１４０によって表示される画像を合成するためのクロスダイクロイックプリズム１４１からなる色合成光学系と、合成された表示画像をスクリーン上に拡大投射するための投射レンズ１４２とを備える構成である。
【０１８６】
液晶表示素子１３８〜１４０は、薄膜トランジスタ（ＴＦＴ）を画素毎に配列して液晶を駆動させるアクティブマトリクス型である。また、各液晶表示素子１３８〜１４０のクロスダイクロイックプリズム１４１側の面に、偏光方向が偏光変換インテグレータ１３２の偏光方向と直交する偏光板（不図示）が設けられている。
【０１８７】
次に、上記構成の液晶プロジェクタの動作について説明する。
【０１８８】
液晶プロジェクタは、図に示すように、光源１３０から出射された光をリフレクタ１３１で集光した後、その光束からダイクロイックミラー１３３で赤色の光束を分離し、ダイクロイックミラー１３４で緑色の光束を分離して、赤色、緑色および青色の３色の光束に分離する。赤色の光束は、全反射ミラー１３５で反射した後、赤色用液晶表示素子１３８を照明する。また、緑色の光束は緑色用液晶表示素子１３９を照明し、青色の光束は全反射ミラー１３６、１３７で順次反射した後、青色用液晶表示素子１４０を照明する。赤色、緑色、および青色の液晶表示素子１３８〜１４０に表示される各画像は、クロスダイクロイックプリズム１４１によって合成された後、投射レンズ１４２によりスクリーン（不図示）に拡大投影される。
【０１８９】
上記構成による液晶プロジェクタは、マイクロレンズが入射される光を画素の開口部に集光するため、輝度が向上してスクリーン上の投影像がより明るくなり、本発明のマイクロレンズアレイ基板１２を用いることにより、投影像の全体の明るさが均一になる。
【０１９０】
次に、上記液晶表示素子を液晶表示装置に応用する場合について説明する。
【０１９１】
図８は半透過型の液晶表示装置の外観を模式的に示す斜視図である。
【０１９２】
図に示すように、液晶表示装置は、上記液晶表示素子１５１と、偏光板１５２、１５３と、光源となるバックライトユニット１５４と、画素毎に設けられたＴＦＴに信号を送るための信号供給回路１５５と、バックライトユニット１５４および信号供給回路１５５に電源を供給する電源供給部１５６とを備える構成である。
【０１９３】
バックライトユニット１５４に赤色、緑色および青色からなる３原色のランプを設けて、この３原色ランプの点灯を高速で切り換える制御を行うことにより液晶表示装置の画面をカラー表示にできるが、バックライトユニット１５４に３原色ランプを設ける代わりに液晶表示素子１５１にカラーフィルターを設けてもよい。
【０１９４】
上記構成による液晶表示装置は、マイクロレンズアレイがバックライトの光利用率を高めるため表示がより明るくなり、本発明のマイクロレンズアレイ基板１２を用いることにより、表示画面内における輝度が均一になる。
【０１９５】
本実施形態による液晶表示素子を、例えば、特開２０００−２９８２６７号公報に示される半透過型の液晶表示装置に用いることができる。
【０１９６】
なお、本実施形態により作製された液晶表示素子を、上記半透過型の液晶表示装置に限らず、半透過型より遮光率の大きい微透過型、および半透過型より遮光率の小さい微反射型の液晶表示装置にも適用できる。
【０１９７】
（第２の実施形態）
第２の実施形態では、上記第１の実施形態により作製されたマイクロレンズアレイ基板１２を、２Ｐ成型法によるマイクロレンズアレイ作製のための母型に用いたものである。
【０１９８】
図９は本発明の第２実施形態を製造工程順に示した断面図である。
【０１９９】
まず、図９（Ａ）に示すように、母型６の凹部形成面に離型剤７と、樹脂８として紫外線硬化樹脂とを順に塗布した後、樹脂８を塗布した面を下側に向ける。
【０２００】
次に、基板３０として無アルカリガラスを用いて基板３０の面と樹脂８の面とを合わせて、母型６を基板３０側に押し付ける（図９（Ｂ））。樹脂８に紫外線を照射して硬化させた後、母型６を剥離することで、凸型に成型された樹脂８を基板３０上に形成し、樹脂８と基板３０とからなるマイクロレンズアレイ３２が得られる（図９（Ｃ））。
【０２０１】
なお、図９（Ｃ）に示した工程の後、樹脂８の上から全面に異方性エッチングを行い、樹脂８の凸型形状を基板３０に転写してもよい。
【０２０２】
また、上記樹脂８は、光照射により硬化する光硬化樹脂、加熱により硬化する熱硬化樹脂、または２液性接着剤であっても好適である。上記母型６の材料としては、基板３０と同種のものか、基板３０と熱膨張係数の近いものを用いるとよい。
【０２０３】
本実施形態では、上記第１の実施形態のマイクロレンズアレイ基板１２には大面積に均一な凹部形状が形成されているため、マイクロレンズアレイ基板１２を母型６に用いることで、大型の母型を高い歩留まりで安価に作製することが可能となる。
【０２０４】
また、母型６と基板３０に同種の材料、または熱膨張係数の近い材料を用いることにより、母型６の材料として金属や石英ガラス基板など、基板３０と異なる材料を用いる場合と比較して、熱膨張係数の違いに起因する誤差を小さくでき、厳密な温度管理が不要となる。また、熱硬化樹脂を用いた際の、加熱工程で生じる誤差を小さくすることができる。
【０２０５】
さらに、母型６および基板３０の材料として、安価な無アルカリガラスなどを用いることができるため、低コスト化が可能となる。また、大型の母型６を使用してマイクロレンズアレイ３２を成型できるため、小型の母型を用いて多数回、高精度で型押しする必要はなく、コスト面で有利となる。
【０２０６】
なお、本実施形態により作製されたマイクロレンズアレイ３２を液晶プロジェクタのライトバルブ用マイクロレンズアレイとして使用する場合には、次のような工程を追加する。
【０２０７】
まず、マイクロレンズアレイ３２の凸型成型面に樹脂８または基板３０に比べて低屈折率な接着剤を塗布してガラスを貼合する。次に、マイクロレンズアレイ３２の凸部に形成されたレンズの焦点が公知の方法で作製されたＴＦＴ基板の透過部に合うように、ガラスの厚みを調整した後、上記ＴＦＴ基板をマイクロレンズアレイ１２に貼り合わせて、ライトバルブ用マイクロレンズアレイを得る。
【０２０８】
この後、ライトバルブ用マイクロレンズアレイに配線となる透明電極や位置合わせのためのマーカなどの形成を行い、公知のパネル作製工程を実施することで、液晶プロジェクタ用のマイクロレンズアレイ付ライトバルブを得る。
【０２０９】
また、本実施形態により作製されたマイクロレンズアレイ３２を、マイクロレンズアレイ付液晶表示素子に応用するためには、次のような工程を実施すればよい。なお、マイクロレンズアレイ付液晶表示素子の応用例としては、半透過型、微透過型、または微反射型の液晶表示素子である。
【０２１０】
まず、適当な厚みの基板を用いて公知の方法により作製した液晶表示素子の光入射側基板の表面に樹脂８を塗布して、この樹脂８に上記母型６を用いて型押しを行った後、樹脂８を硬化させてマイクロレンズアレイ３２を得る。次に、マイクロレンズアレイ３２のレンズを透過するバックライト光がＴＦＴ基板の画素電極の透過部に集光するように位置合わせを行って、光入射側基板をＴＦＴ基板に組み付けることで、マイクロレンズアレイ付液晶表示素子を得る。これにより、レンズパターンの均一なマイクロレンズアレイ付液晶表示素子をより低コストで作製できる。
【０２１１】
（第３の実施形態）
第３の実施形態は、本発明を等方性エッチング法による光導波路の作製に適用する形態である。
【０２１２】
図１０は本発明の第３の実施形態を製造工程順に示した断面図である。
【０２１３】
図１０（Ａ）に示すように、基板１として、第１の実施形態と同様に、酸化アルミニウム等を均一に含有する無アルカリガラスを用いて、この基板１上に金属膜２およびレジスト３からなるエッチング用マスクを形成する。
【０２１４】
なお、光導波路のパターンに倣った四角形の開口部３ｂをエッチング用マスクに形成するが、開口部３ｂの対向する二辺の幅については、第１の実施形態で示した表１のような、上記開口部３ｂの幅と形成される光導波路の幅との関係を示す表を予め作成し、作成した表に基づいて形成される光導波路の幅から決定する。
【０２１５】
次に、エッチャント４としてフッ酸系エッチング液を用いて基板１のエッチングを行う。図１０（Ｂ）はエッチングの初期段階の状態を示した断面図である。
【０２１６】
エッチングが始まると、上記開口部３ｂから基板１の等方性エッチングが進行し、微小な溝部が形成される。この微小な溝部中の基板表面に、エッチングにより生じた、エッチャントに対する不溶物５であるフッ化アルミニウム等が蓄積し、基板１のエッチングの進行を阻害し、最終的にはエッチングが停止して光導波路パターンが形成される（図１０（Ｃ））。
【０２１７】
金属膜２およびレジスト３とともに不溶物５を除去した後、基板１に比べて屈折率の高い高屈折率材料を、形成された溝部に埋め込み、光導波路１３を形成する（図１０（Ｄ））。
【０２１８】
本実施形態では、基板１にエッチャント４に対する不溶物５を生成する物質として酸化アルミニウム等が含まれ、エッチングによりエッチャント４に対する不溶物５が生成されるため、ある程度エッチングが進行した状態でエッチングが自動的に停止し、エッチングストッパ層などを設けることなく、大面積の基板でも均一な光導波路のパターンを安価に作製することができる。また、各エッチング処理におけるエッチング量のばらつきがなく、エッチング処理間における凹部形状が均一な光導波路用パターンを形成できる。
【０２１９】
また、第１の実施形態で述べたように、基板１がオキシハライドガラスであれば、フッ酸系エッチング液に溶解しない物質としてフッ化カルシウム等が含有されるため、フッ化カルシウム等が上記不溶物５と同様な作用および効果を生じさせる。
【０２２０】
なお、金属膜２およびレジスト３とともに不溶物５を除去した後、作製された光導波路状の窪みパターンを母型にして、２Ｐ成型法を用いて別の基板上に高屈折率材料を成型した光導波路を形成することにより、ストリップ導波路やリブ導波路を得ることも可能である。この場合にも、大型の母型を高い歩留まりで安価に作製することが可能であること、熱膨張係数の違いに起因する誤差を小さくでき厳密な温度管理が不要となること、熱硬化樹脂を用いた際の加熱工程における誤差を小さくできること、母型の材料として安価な無アルカリガラスなどを用いることができるため低コスト化が可能であること、などの効果を得ることができる。
【０２２１】
（第４の実施形態）
第４の実施形態は、本発明を等方性エッチング法による埋め込み配線の作製に適用する形態である。
【０２２２】
図１１は本発明の第４の実施形態を製造工程順に示した断面図である。
【０２２３】
図１１（Ａ）に示すように、基板１として、第１の実施形態と同様に、酸化アルミニウム等を均一に含有する無アルカリガラスを用いて、この基板１上に金属膜２およびレジスト３からなるエッチング用マスクを形成する。
【０２２４】
なお、埋め込み配線のパターンに倣った四角形の開口部３ｃをエッチング用マスクに形成するが、開口部３ｃの対向する二辺の幅については、第１の実施形態で示した表１のような、上記開口部３ｃの幅と形成される埋め込み配線の幅との関係を示す表を予め作成し、作成した表に基づいて形成される埋め込み配線の幅から決定する。
【０２２５】
次に、エッチャント４としてフッ酸系エッチング液を用いて基板１のエッチングを行う。図１１（Ｂ）はエッチングの初期段階の状態を示した断面図である。
【０２２６】
エッチングが始まると、上記開口部３ｃより基板１の等方性エッチングが進行し、微小な溝部が形成される。この微小な溝部中の基板表面に、エッチングにより生じた、エッチャントに対する不溶物５であるフッ化アルミニウム等が蓄積し、基板１のエッチングの進行を阻害し、最終的にはエッチングが停止して配線パターンが形成される（図１１（Ｃ））。
【０２２７】
金属膜２およびレジスト３とともに不溶物５を除去した後、スパッタ法などの公知の方法を用いて、配線用金属層９を成膜する（図１１（Ｄ））。次に、化学的または機械的な研磨法を用いて、形成された溝部中以外の配線用金属層９を除去して、埋め込み配線９ａを形成する（図１１（Ｅ））。
【０２２８】
本実施形態では、基板１にエッチャント４に対する不溶物５を生成する物質として酸化アルミニウム等が含まれ、エッチングによりエッチャント４に対する不溶物５が生成されるため、ある程度エッチングが進行した状態でエッチングが自動的に停止し、大面積の基板でも均一な埋め込み配線用のパターンを安価に作製することができる。また、各エッチング処理におけるエッチング量のばらつきがなく、エッチング処理間における凹部形状が均一な埋め込み配線用パターンを形成できる。
【０２２９】
また、第１の実施形態で述べたように、基板１がオキシハライドガラスであれば、フッ酸系エッチング液に溶解しない物質としてフッ化カルシウム等が含有されるため、フッ化カルシウム等が上記不溶物５と同様な作用および効果を生じさせる。
【０２３０】
（第５の実施形態）
第５の実施形態は、本発明を等方性エッチング法による回折格子の作製に適用する形態である。
【０２３１】
図１２は本発明の第５の実施形態を製造工程順に示した断面図である。
【０２３２】
図１２（Ａ）に示すように、酸化アルミニウム等を均一に含有する無アルカリガラスの基板１上にスピンコートなどの公知の手法を用いて、レジスト３を塗布し、乾燥させる。なお、レジスト３としては、次工程の露光で使用する光の波長に対応し、かつ回折格子を形成できるだけの解像度を有するものを使用する。一例として、エキシマレーザ用フォトレジストを好適に使用することができる。
【０２３３】
この後、エキシマレーザ光などを使用してレジスト３に干渉露光を行い、レジストの現像工程を経て、微細な開口部３ｄからなる回折格子パターンを有するエッチング用マスクを形成する（図１２（Ｂ））。
【０２３４】
なお、回折格子のパターンに倣った四角形の開口部３ｄをエッチング用マスクに形成するが、開口部３ｄの対向する二辺の幅および開口部３ｄの間隔については、第１の実施形態で示した表１のような、上記開口部３ｄの幅および間隔と形成される回折格子の凹部の幅との関係を示す表を予め作成し、作成した表に基づいて形成される回折格子の凹部の幅から決定する。
【０２３５】
次に、エッチャント４としてフッ酸系エッチング液を用いて基板１のエッチングを行う。図１２（Ｃ）はエッチングの初期段階の状態を示した断面図である。
【０２３６】
エッチングが始まると、開口部３ｄ部分より基板１の等方性エッチングが進行し、微小な溝部が形成される。この微小な溝部中の基板１の表面に、エッチングにより生じた、エッチャント４に対する不溶物５であるフッ化アルミニウム等が蓄積し、基板１のエッチングの進行を阻害し、最終的にはエッチングが停止する。
【０２３７】
この後、レジスト３の剥離を行って不溶物５を洗い流すと、図１２（Ｄ）に示すように、複数の溝部が設けられた回折格子３４が形成される。
【０２３８】
本実施形態では、基板１にエッチャント４に対する不溶物５を生成する物質として酸化アルミニウム等が含まれ、エッチングによりエッチャント４に対する不溶物５が生成されるため、ある程度エッチングが進行した状態でエッチングが自動的に停止し、大面積の基板でも均一な回折格子のパターンを安価に作製することができる。また、各エッチング処理におけるエッチング量のばらつきがなく、エッチング処理間におけるパターン形状が均一な回折格子を形成できる。
【０２３９】
なお、基板１は、第１の実施形態と同様に、上記無アルカリガラスの他に、低アルカリガラス、ホウ珪酸ガラス、鉛ガラスでもよい。基板１がオキシハライドガラスであれば、フッ酸系エッチング液に溶解しない物質としてフッ化カルシウム等が含有されるため、フッ化カルシウム等が上記不溶物５と同様な作用および効果を生じさせる。
【０２４０】
また、このようにして作製された回折格子３４は、大面積・安価な光学素子として使用することもできるが、例えば、有機エレクトロルミネッセンス素子の基板として使用することで、光取り出し効率を向上することもできる。この場合には、安価な無アルカリガラス基板を使用して、安価な手法で大面積の回折格子３４を作製できる利点を最大限に活用することができる。
【０２４１】
（第６の実施形態）
第６の実施形態は、本発明を等方性エッチング法による液晶配向膜の作製に適用する形態である。
【０２４２】
図１３は本発明の第６の実施形態を製造工程順に示した断面図である。
【０２４３】
図１３（Ａ）に示すように、基板１上に透明電極１０を形成し、透明電極１０の上に液晶分子の配列方向を決めるための配向膜１１を形成する。なお、この配向膜１１は、酸化アルミニウム等を均一に含有させた無機材料の膜である。
【０２４４】
次に、図１３（Ｂ）に示すように、第５の実施形態と同様な方法を用いてエッチング用マスクを形成するが、四角形の開口部３ｅの長手方向を注入する液晶分子の配列方向にほぼ一致させておく。エッチング用マスクの材質としては、レジスト３などを好適に用いることができる。
【０２４５】
なお、形成される液晶配向膜のパターンに倣った四角形の開口部３ｅをエッチング用マスクに形成するが、開口部３ｅの対向する二辺の幅および開口部３ｅの間隔については、第１の実施形態で示した表１のような、上記開口部３ｅの幅および間隔と形成される液晶配向膜の凹部の幅との関係を示す表を予め作成し、作成した表に基づいて形成される液晶配向膜の凹部の幅から決定する。
【０２４６】
この後、エッチャント４としてフッ酸系エッチング液を用いて配向膜１１のエッチングを行う。図１３（Ｃ）はエッチングの初期段階の状態を示した断面図である。
【０２４７】
エッチングが始まると、配向膜１１の等方性エッチングが進行し、微小な溝部が形成される。この微小な溝部中の配向膜表面に、エッチングにより生じた、エッチャント４に対する不溶物５であるフッ化アルミニウム等が蓄積し、配向膜１１のエッチングの進行を阻害し、最終的にはエッチングが停止する。
【０２４８】
次に、レジスト３の剥離を行って不溶物５を洗い流すと、図１３（Ｄ）に示すように、溝部と直線状突部とが交互に複数設けられた液晶配向膜１１ａが形成される。
【０２４９】
本実施形態では、配向膜１１にエッチャント４に対する不溶物５を生成する物質として酸化アルミニウム等が含まれ、エッチングによりエッチャント４に対する不溶物５が生成されるため、ある程度エッチングが進行した状態でエッチングが自動的に停止し、大面積の基板上に作製する場合でも均一な凹凸形状を有する液晶配向膜を安価に作製することができる。また、各エッチング処理におけるエッチング量のばらつきがなく、エッチング処理間におけるパターン形状が均一な液晶配向膜を形成できる。
【０２５０】
また、上記不溶物５を生成させる酸化アルミニウム等を含有させる代わりに、配向膜１１にエッチャント４に溶解しない物質として、第１実施形態で述べたフッ化カルシウム等の物質から少なくとも一つ含有させるようにしてもよい。配向膜１１にエッチャント４に溶解しない物質を含有させることにより、この物質が上記不溶物５と同様の作用および効果を生じさせる。
【０２５１】
さらに、上記液晶配向膜１１が形成された基板１を２枚用いて、そのうちの１枚にシール材を印刷した後２枚の基板１を貼り合せてパネル化し、パネル内に液晶を注入して液晶表示素子とした。これにより、信頼性、均一性の高い液晶配向膜を、大面積に渡って安価に作製することができる。
【０２５２】
特に、上記配向膜１１として無機材料を用いることにより、液晶が注入される空間を仕切るための隔壁構造と組み合わせて用いた場合に、隔壁作製プロセスによる配向膜のダメージをなくすことができ、配向膜のダメージを受けやすいスメクティック液晶を使用した場合でも均一な配向を得ることができる。
【０２５３】
（第７の実施形態）
第７の実施形態は、本発明をワイヤーグリッド型の偏光光学素子の作製に適用する形態である。
【０２５４】
図１４は本発明の第７の実施形態を製造工程順に示した断面図である。
【０２５５】
図１４（Ａ）に示すように、基板１上に金属膜２０を形成する。なお、金属膜２０の材質としては、例えば、ＴｉとＡｌの合金等が使用可能であり、公知のスパッタ法等を用いて成膜する。
【０２５６】
次に、図１４（Ｂ）に示すように、第５の実施形態と同様な方法を用いて、エッチング用マスクをレジスト３で形成するが、四角形の開口部３ｆの長手方向は透過させる偏光方向と直交させておく。
【０２５７】
なお、形成される偏光光学素子のパターンに倣った四角形の開口部３ｆをエッチング用マスクに形成するが、開口部３ｆの対向する二辺の幅および開口部３ｆの間隔については、第１の実施形態で示した表１のような、上記開口部３ｆの幅および間隔と形成される偏光光学素子の凹部の幅との関係を示す表を予め作成し、作成した表に基づいて形成される偏光光学素子の凹部の幅から決定する。
【０２５８】
この後、フッ酸を含有させた金属膜エッチャント４０を用いて金属膜２０のエッチングを行う。図１４（Ｃ）はエッチングの初期段階の状態を示した断面図である。
【０２５９】
エッチングが始まると、金属膜２０の等方性エッチングが進行し、微小な溝部が形成される。この微小な溝部中の金属膜表面に、エッチングにより生じたエッチャント４に対する不溶物５であるフッ化アルミニウムが蓄積し、金属膜２０のエッチングの進行を阻害し、最終的にはエッチングが停止する。
【０２６０】
その後、レジスト３の剥離を行って不溶物５を洗い流すと、図１４（Ｄ）に示すように、溝部と金属線とが交互に複数設けられた、ワイヤーグリッド型の偏光光学素子２０ａを得る。
【０２６１】
本実施形態では、金属膜２０にエッチャント４に対する不溶物５を生成する物質であるアルミニウムが含まれ、エッチングによりエッチャント４に対する不溶物５が生成されるため、ある程度エッチングが進行した状態でエッチングが自動的に停止し、大面積の基板上に作製する場合でも金属線パターンの均一なワイヤーグリッド型偏光光学素子を安価に作製することができる。また、各エッチング処理におけるエッチング量のばらつきがなく、エッチング処理間におけるパターン形状が均一な偏光光学素子を形成できる。
【０２６２】
また、開口部３ｆからのエッチングが基板１に達したときにレジスト３下における金属膜２０のサイドエッチングが停止する条件を用いることで、レジスト３下における金属膜２０のオーバーエッチングを防止することができる。
【０２６３】
なお、上記金属膜２０に、マグネシウム、カルシウム、カリウム、ストロンチウム、バリウム、リチウム、ナトリウム、セシウム、亜鉛、および鉛の物質のうち少なくとも一つを含有するようにしてもよい。これらの物質は、上記アルミニウムと同様に、フッ酸と反応して上記不溶物５を生成する。
【０２６４】
（第８の実施形態）
第８の実施形態は、本発明を等方性エッチング法による、マイクロ化学分析システムやＬＯＣに使用されるマイクロチップのパターン作製に適用する形態である。
【０２６５】
図１５は基板表面に作製された、マイクロチップの凹部パターンを示す上面図である。
【０２６６】
図１５に示すように、マイクロチップの基板１の表面には、薬品が注入される試薬槽１５と、各種薬品を混合させて反応をさせる反応槽１６と、試薬槽１５から反応槽１６に薬品が移動するためのマイクロチップ用液出路１４とが設けられている。
【０２６７】
上記マイクロチップ用液出路１４の作製方法について以下に説明する。
【０２６８】
図１６は本発明の第８の実施形態を製造工程順に示した断面図である。なお、図１６に示す部分は、図１５に示した破線部分ＹＹ’の断面である。
【０２６９】
図１６（Ａ）に示すように、基板１として、第１の実施形態と同様に、酸化アルミニウム等を均一に含有する無アルカリガラスを用いて、この基板１上に、マイクロチップ用液出路を形成するための、金属膜２およびレジスト３からなるエッチング用マスクを形成する。
【０２７０】
なお、マイクロチップ用液出路１４のパターンに倣った四角形の開口部３ｇをエッチング用マスクに形成するが、開口部３ｇの対向する二辺の幅については、第１の実施形態で示した表１のような、上記開口部３ｇの幅と形成されるマイクロチップ用液出路１４の幅との関係を示す表を予め作成し、作成した表に基づいて形成されるマイクロチップ用液出路１４のパターンの幅から決定する。
【０２７１】
次に、エッチャント４としてフッ酸系エッチング液を用いて基板１のエッチングを行う。図１６（Ｂ）はエッチングの初期段階の状態を示した断面図である。
【０２７２】
エッチングが始まると、上記開口部３ｇより基板１の等方性エッチングが進行し、微小な溝部が形成される。この微小な溝部中の基板表面に、エッチングにより生じた、エッチャントに対する不溶物５であるフッ化アルミニウム等が蓄積し、基板１のエッチングの進行を阻害し、最終的にはエッチングが停止して液出路パターンが形成される（図１６（Ｃ））。
【０２７３】
金属膜２およびレジスト３とともに不溶物５を除去した後、マイクロチップ用液出路１４を得る（図１６（Ｄ））。
【０２７４】
なお、上述した作製方法により、試薬槽１５および反応槽１６についても、上記マイクロチップ用液出路１４と同様に、不溶物５が蓄積されることでパターンが形成される。
【０２７５】
マイクロチップ用液出路１４のパターン間隔を狭くしてパターン集積度を大きくする場合には、開口部３ｇの対向する二辺の幅および開口部３ｇの間隔について、上記第１実施形態と同様に、開口部３ｇの対向する二辺の幅および開口部３ｇの間隔と、マイクロチップ用液出路１４の幅との関係を示す表を作成し、形成されるマイクロチップ用液出路１４の幅から決めればよい。
【０２７６】
また、本実施形態では、マイクロチップ用パターンの作製方法として、上記マイクロチップ用液出路１４のパターンについて説明したが、試薬槽１５および反応槽１６のパターンについても、本実施形態を適用することができる。その際、マイクロチップ用パターンが四角形に限らず八角形なども含む多角形であれば、上記開口部３ｇの対向する二辺の幅を開口部３ｇの最大幅に替えて、開口部３ｇの最大幅と形成されるマイクロチップ用パターンの幅との関係を示す表を予め作成し、作成した表に基づいて形成されるマイクロチップ用パターンの幅から開口部３ｇの最大幅を決定すればよい。
【０２７７】
本実施形態では、基板１にエッチャント４に対する不溶物５を生成する物質として酸化アルミニウム等が含まれ、エッチングによりエッチャント４に対する不溶物５が生成されるため、ある程度エッチングが進行した状態でエッチングが自動的に停止し、大面積の基板でも均一なマイクロチップ用パターンを安価に作製することができる。また、各エッチング処理におけるエッチング量のばらつきがなく、エッチング処理間における凹部形状が均一なマイクロチップ用パターンを形成できる。
【０２７８】
また、第１の実施形態で述べたように、基板１がオキシハライドガラスであれば、フッ酸系エッチング液に溶解しない物質としてフッ化カルシウム等が含有されるため、フッ化カルシウム等が上記不溶物５と同様な作用および効果を生じさせる。
【０２７９】
なお、本発明は、以上説明したような第１の実施形態から第８の実施形態における微細構造の形成用途に限定されるものではなく、大構造を形成する場合でも、エッチング量を制御し、形成されるパターン形状の均一性を向上する目的で使用することができる。大構造を形成する場合でも、エッチャントに対する不溶物が被エッチング体の表面に蓄積して、エッチングの進行を停止させることができるからである。
【０２８０】
また、等方性エッチングだけでなく、エッチングにある程度の異方性がある場合でも、上述したように、エッチング液に不溶な物質を生成させることでエッチングを停止させ、形成されるパターン形状の均一性を向上する目的で使用することができる。
【０２８１】
【発明の効果】
本発明は以上説明したように構成されているので、以下に記載する効果を奏する。
【０２８２】
本発明の等方性エッチング法を用いた微細構造形成方法を用いて得られる微細構造について、大型の基板について複数枚のエッチング処理に本発明を使用した場合でも、基板面内のみならず基板間でも均一性の高い微細構造を作製することができる。また、比較的安価な液晶表示素子用ガラスを使用できるため、低コスト化が可能になる。
【０２８３】
さらに、本発明を２Ｐ成型法における母型の作製に使用することで、大型の母型を高い歩留まりで安価に作製することが可能となるばかりでなく、母型と同種の基板を使用することで熱膨張係数の違いに起因する誤差を小さくすることができ、厳密な温度管理が不要になる。大型の母型が使用できるため、低コスト化が可能となる。
【図面の簡単な説明】
【図１】本発明の第１の実施形態を製造工程順に示した断面図である。
【図２】第１の実施形態により作製されたマイクロレンズアレイ基板１２を用いた液晶表示素子の外観を模式的に示す斜視図である。
【図３】第１の実施形態により作製されたマイクロレンズアレイ基板を用いた液晶表示素子の作製方法を製造工程順に示した断面図である。
【図４】第１の実施形態により作製されたマイクロレンズアレイ基板を用いた液晶表示素子の作製方法を製造工程順に示した断面図である。
【図５】第１の実施形態により作製されたマイクロレンズアレイ基板を用いた液晶表示素子の作製方法を製造工程順に示した断面図である。
【図６】第１の実施形態により作製されたマイクロレンズアレイ基板を用いた液晶表示素子について別の構成例を示す断面図である。
【図７】図２に示した液晶表示素子を用いた液晶プロジェクタの一構成例を示す模式図である。
【図８】図２に示した液晶表示素子を用いた半透過型の液晶表示装置の外観を模式的に示す斜視図である。
【図９】本発明の第２の実施形態を製造工程順に示した断面図である。
【図１０】本発明の第３の実施形態を製造工程順に示した断面図である。
【図１１】本発明の第４の実施形態を製造工程順に示した断面図である。
【図１２】本発明の第５の実施形態を製造工程順に示した断面図である。
【図１３】本発明の第６の実施形態を製造工程順に示した断面図である。
【図１４】本発明の第７の実施形態を製造工程順に示した断面図である。
【図１５】本発明の第８の実施形態により作製されるマイクロチップの凹部パターンを示す上面図である。
【図１６】本発明の第８の実施形態を製造工程順に示した断面図である。
【図１７】従来の２Ｐ成型法を用いたマイクロレンズアレイの製造工程を説明するための断面図である。
【図１８】従来の転写法を用いたマイクロレンズアレイの製造工程を説明するための断面図である。
【図１９】従来の等方性エッチング法を用いたマイクロレンズアレイの製造工程を説明するための断面図である。
【符号の説明】
１、３０、２０１　　基板
１ａ、２０１ａ　　柱状パターン
２、２０、２０２　　金属膜
３、２０３　　レジスト
３ａ、３ｂ、３ｃ、３ｄ、３ｅ、３ｆ、３ｇ、２０３ａ　　開口部
４　　エッチャント
５　　不溶物
６、１１４　　母型
７、１０７　　離型剤
８、１０８　　樹脂
９　　配線用金属層
９ａ　　埋め込み配線
１０　　透明電極
１１　　配向膜
１１ａ　　液晶配向膜
１２、２１２　　マイクロレンズアレイ基板
１３　　光導波路
１４　　マイクロチップ用液出路
１５　　試薬槽
１６　　反応槽
２０ａ　　偏光光学素子
３２、１１２、１２０、１２２　　マイクロレンズアレイ
３４　　回折格子
４０　　金属膜エッチャント
５０、２５０ａ　　ＴＦＴ基板
５１、２５１　　調整用ガラス板
５２、２５２　　液晶層
１００　　ガラス基板
１０４　　ウェットエッチング液
１１５　　熱変形性パターン
１１５ａ　　半球状パターン
１１６　　マスク層
１１７　　石英ガラス基板
１３０　　光源
１３１　　リフレクタ
１３２　　偏光変換インテグレータ
１３３、１３４　　ダイクロイックミラー
１３５、１３６、１３７　　全反射ミラー
１３８　　赤色用液晶表示素子
１３９　　緑色用液晶表示素子
１４０　　青色用液晶表示素子
１４１　　クロスダイクロイックプリズム
１４２　　投射レンズ
１５１、２６０　　液晶表示素子
１５２、１５３　　偏光板
１５４　　バックライトユニット
１５５　　信号供給回路
１５６　　電源供給部
２０３ｂ　　露光位置調整マーカ
２１２ａ　　個片にしたマイクロレンズアレイ基板
２５０ａ　　個片にしたＴＦＴ基板
２５３　　保護材
２５４　　高屈折率接着剤
２５５　　重ね合わせ位置調整マーカ
２５６　　画素遮光部
２５７　　ＴＦＴ基板側重ね合わせ位置調整マーカ
２５８　　シール剤[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for forming a fine structure using an isotropic etching method, a microlens array substrate, a matrix for a microlens array, a liquid crystal display device, a liquid crystal display device, and a liquid crystal projector.
[0002]
[Prior art]
With the recent development of fine structure forming technology, many attempts are being made to introduce a fine structure into an existing element to achieve higher functionality, higher performance, and higher added value. In particular, recently, it has become possible to process even a scale close to the wavelength of light, and thus these attempts are expected to be promising in the field of optical elements and display elements.
[0003]
As an example, in the field of liquid crystal display devices, a technique of providing a microlens array having a pixel size on a glass substrate has been studied. This is because the aperture ratio of the liquid crystal display element is necessarily limited by the presence of wirings and electrodes for driving display pixels. In particular, in an active matrix type liquid crystal display device using a thin film transistor (TFT), a typical aperture ratio is about 60% or less. Attempts have been made to provide a microlens array on the substrate on which light is incident and concentrate the incident light on the aperture to improve the effective aperture ratio, thereby realizing bright display and low power consumption. ing. Such attempts are particularly important in applications where there is a great demand for brightness and power consumption.
[0004]
For example, in a liquid crystal projector, improvement of brightness is very important in order to realize a clear display even in a bright environment, and mounting of a microlens array on a liquid crystal panel used as a light valve is being studied. . In such an application, it is necessary to manufacture a large number of microlenses of at least the number of pixels.
[0005]
As a method for manufacturing a microlens array, a method using a 2P molding method is disclosed (for example, see Patent Document 1). FIG. 17 is a sectional view illustrating this method for each process. A method for manufacturing a microlens array will be described with reference to FIG. First, a glass substrate 100, a matrix 114 having a large number of substantially hemispherical concave portions formed on a molding surface, a release agent 107, and an uncured resin 108 are prepared. As shown in FIG. A mold release agent 107 and an uncured resin 108 are applied to the molding surface side of the mother die 114. Next, the surface of the resin 8 and the surface of the glass substrate 100 are aligned, and the matrix 114 is pressed against the glass substrate 100, and the uncured resin 108 is press-molded on the molding surface of the matrix 114 (FIG. B)). After that, the resin 108 is cured by ultraviolet rays or the like, and a microlens array 112 including a resin lens layer is formed on a glass substrate (FIG. 17C).
[0006]
Another example of the 2P molding method discloses a method using a silicon substrate having excellent workability and flatness as a matrix (for example, see Patent Document 2).
[0007]
As another example of a method for manufacturing a microlens array, a transfer method using both heating and dry etching is disclosed (for example, see Patent Document 3). FIG. 18 is a sectional view illustrating this method for each process. A method for manufacturing a microlens array will be described with reference to FIG. As shown in FIG. 18A, after a heat-deformable pattern 115 made of a heat-deformable material is formed on a glass substrate 100, a substantially hemispherical hemispherical pattern 115a is formed by utilizing pattern deformation in a heating step. (FIG. 18B). Next, the glass substrate 100 is dry-etched using the hemispherical pattern 115a as a mask, so that a substantially hemispherical convex shape is transferred to the glass substrate 100, thereby manufacturing the microlens array 120 (FIG. 18C).
[0008]
Further, a method of forming a microlens array using an isotropic etching method is disclosed (for example, see Patent Document 4). FIG. 19 is a sectional view illustrating this method for each process. A method for forming a microlens array will be described with reference to FIG. First, an etching mask layer 116 made of silicon is formed on the surface of a quartz glass substrate 117 (FIG. 19A). Next, as shown in FIG. 19B, isotropic etching is performed on the quartz glass substrate 117 using the wet etching solution 104. After that, the mask layer 116 is separated to form the microlens array 122 (FIG. 19C).
[0009]
As described above, many studies have been made on microlens arrays for use in liquid crystal projectors.
[0010]
In addition to the projector application, attempts are being made to apply the microlens array to a transflective liquid crystal display device. A method is disclosed in which a microlens array for condensing backlight light is provided in a minute opening of a reflection plate to effectively utilize backlight light during transmission display and reduce power consumption (for example, Japanese Patent Application Laid-Open No. H11-157572). And Patent Document 5).
[0011]
As another example to which the fine structure forming technique is applied, an optical waveguide can be cited. An optical switch and an arrayed waveguide grating multiplexer / demultiplexer are realized by providing a large number of waveguides and 3 dB couplers on a quartz glass substrate (for example, see Non-Patent Document 1). These optical switches and demultiplexers are used for wavelength separation of multiplexed light and optical add / drop in a wavelength division multiplexing communication system, but there is a limit to miniaturization due to loss of a waveguide and characteristics of wavelength separation. In particular, the number of multiplexed wavelengths is expected to increase in the future, and as a result, the area tends to be inevitably increased.
[0012]
In addition, an attempt has been disclosed to bury the wiring of a liquid crystal display element in a substrate to reduce unevenness on the surface of the substrate to make the orientation of liquid crystal uniform, thereby improving the display performance of the liquid crystal display element. 6).
[0013]
Attempts have been made to form a diffraction grating having a periodic structure of about a wavelength on a substrate by a fine structure forming technique. In particular, a method is disclosed in which a diffraction grating is formed on a substrate of an organic electroluminescence element to improve light extraction efficiency from a light emitting layer (for example, see Patent Document 7).
[0014]
Further, formation of an alignment film of a liquid crystal display element using a microstructure forming technique is disclosed (for example, see Patent Document 8). At present, the most frequently used liquid crystal alignment method is a rubbing method in which an organic film such as polyimide is rubbed with a cloth such as cotton. However, in the rubbing method, there are problems such as deterioration of display quality because the organic film is easily damaged, contamination with dust generated from cotton cloth and the like, and low reliability. Therefore, attempts have been made to form a fine groove structure of about submicron in an inorganic film or the like and to orient the liquid crystal.
[0015]
Also, studies for forming a polarization-dependent optical element have been conducted. In order to give the optical element a polarization-dependent function, there are a method using an optical material having polarization anisotropy and a method using a structural birefringence by forming an ultrafine structure in an isotropic material. In particular, the latter has been receiving particular attention recently with the development of microfabrication technology at the wavelength level to be applied (for example, see Non-Patent Document 2).
[0016]
In addition, a microstructure having a size of about a micrometer to several tens of micromails is formed on a substrate by a microstructure formation technique, and the manufactured microstructure is subjected to a micro-total analysis system (μTAS) or LOC. (Laboratory on a Chip) is being studied. In particular, in recent years, it has been actively applied to the fields of DNA analysis, medical care, and the environment (for example, see Non-Patent Document 3).
[0017]
As described above, the range to which the microstructure forming technique can be applied is very wide, and various studies have been made.
[0018]
[Patent Document 1]
JP 2001-201609 A
[Patent Document 2]
JP 2001-246599 A
[Patent Document 3]
JP 2001-074913 A
[Patent Document 4]
JP 2001-147305 A
[Patent Document 5]
JP 2000-298267 A
[Non-patent document 1]
Kenichi Yukimatsu, "Optical Switching and Optical Interconnection", Kyoritsu Publishing Co., Ltd., p. 137-139
[Patent Document 6]
JP-A-6-82832
[Patent Document 7]
JP-A-11-283751
[Patent Document 8]
JP-A-2000-81625
[Non-patent document 2]
Applied Optics Vol. 39, No. 20, 2000
[Non-Patent Document 3]
"Polymer Nanotechnology and Polymers", edited by The Society of Polymer Science, p. 117-131
[0019]
[Problems to be solved by the invention]
However, in forming a fine structure, improving the shape uniformity is the biggest problem. In addition, in consideration of mass productivity, cost reduction, and high yield, it is essential to use a multi-panel method in which inexpensive materials are collectively manufactured on a large-sized substrate and cut into small pieces after completion. However, when a large substrate is used, it becomes more difficult to achieve uniformity.
[0020]
For example, for a microlens array in a liquid crystal projector, as described above, a 2P molding method, a transfer method using a dry etching method, and an isotropic etching method have been studied, and problems of these methods will be described below. .
[0021]
In terms of fabricating a microstructure on a large substrate, the 2P molding method requires that a large matrix having a microstructure be prepared, and if the materials of the matrix and the substrate are different, a difference in thermal expansion coefficient results. There are problems such as that strict temperature control is required to cause deformation, and that precise control in the height direction is required at the time of embossing. These problems can be solved by, for example, a method of preparing a small mother die and sequentially embossing the substrate a number of times, but it is necessary to precisely control the lateral position. And other new problems.
[0022]
In the dry etching method, although in-plane uniformity is excellent, it is necessary to prepare a large dry etching apparatus and a large vacuum tank in order to process a large substrate. Generally, a large-sized device is expensive, which is disadvantageous for cost reduction. In addition, the number of substrates that can be processed in one process is limited to one in principle, and the vacuum operation takes a long time because the processing is performed in a vacuum, and mass productivity is reduced.
[0023]
On the other hand, in the isotropic etching method described above, by preparing a large etching tank for wet etching, it is possible to relatively easily handle a large substrate. In addition, since a plurality of sheets can be processed at the same time, it is advantageous in terms of cost reduction. However, when a quartz glass substrate or a silicon substrate is used, it is difficult to control the amount of etching by wet etching, so that there is a problem that unevenness is likely to occur in a plane and variation occurs between lots. Further, when the support of the etching mask is lost as the etching progresses, peeling of the mask occurs during the etching, which causes etching unevenness. Further, there is a problem that it is difficult to reduce the cost because an expensive quartz glass substrate or silicon substrate is used.
[0024]
Such a problem occurs not only in the microlens array for a liquid crystal projector but also in the microlens array for a transflective liquid crystal display element when the above manufacturing method is adopted.
[0025]
The same problems as described above also occur in an optical waveguide, a buried wiring, a diffraction grating, a liquid crystal alignment film having a fine groove, a polarization dependent optical element, and a microchip that use a microstructure forming technique. As described above, in microfabrication using isotropic etching, there is a problem that it is difficult to control the etching, and it is difficult to secure in-plane uniformity especially when the size is increased, and the cost is increased. In addition, when dry etching is used, a large-sized apparatus is required, one substrate can be processed in one process, and a vacuum operation is required, so that the process is time-consuming and costly. There are points.
[0026]
The present invention has been made in order to solve the problems of the conventional technology as described above, and has improved the controllability of etching at the time of microfabrication using isotropic etching, and has been achieved even in a large substrate. And a micro-lens array substrate manufactured by the micro-structure forming method of the present invention, and a liquid crystal display device, a liquid crystal display device, and a liquid crystal projector using the micro lens array substrate. The purpose is to do. It is another object of the present invention to provide a method for forming a fine structure in which a large matrix using the same type of material as a substrate is manufactured at a high yield at low cost in the 2P molding method, and strict temperature control is not required.
[0027]
[Means for Solving the Problems]
In order to achieve the above object, the method for forming a microstructure according to the present invention is characterized in that a mask having a predetermined opening is etched from the opening by using an etching solution on the etching target provided on the surface of the etching target, A method for forming a fine structure for forming a concave portion on the surface of the body to be etched,
A reaction between the substance contained in the body to be etched and the etching solution to generate an insoluble material,
The etching is stopped by insoluble matter accumulated on the exposed surface of the object to be etched.
[0028]
In this case, the object to be etched may include at least one of aluminum oxide, magnesium oxide, calcium oxide, potassium oxide, strontium oxide, barium oxide, lithium oxide, sodium oxide, cesium oxide, zinc oxide, and lead oxide. Good.
[0029]
Further, in the method for forming a fine structure according to the present invention, the etching target is etched from the opening using an etchant on the etching target provided with a mask having a predetermined opening on the surface, and the surface of the etching target is etched. A method for forming a fine structure for forming a concave portion in the
Leaching the substance from the body to be etched containing a substance that does not dissolve in the etching solution,
The etching is stopped by a substance accumulated on the exposed surface of the object to be etched.
[0030]
In this case, the body to be etched may include at least one of calcium fluoride, sodium fluoride, barium fluoride, aluminum fluoride, strontium fluoride, and magnesium fluoride.
[0031]
In this case, the etchant may contain hydrofluoric acid.
[0032]
In any of the fine structure forming methods of the present invention, the fine structure may be a microlens.
[0033]
In this case, the opening provided in the mask is circular,
Create a table showing the relationship between the diameter of the opening and the diameter of the recess formed corresponding to the diameter of the opening,
The mask may be formed with a diameter of the opening corresponding to a desired concave diameter according to the table.
[0034]
Further, in any of the above-described fine structure forming methods of the present invention, the fine structure may be used in a microlens array in which concave portions are continuously formed.
[0035]
In this case, the opening provided in the mask is circular,
Create a table showing the relationship between the diameter and spacing of the opening, the diameter of the recess formed corresponding to the diameter and spacing of the opening,
According to the above table, the diameter and interval of the opening corresponding to the desired diameter of the concave portion may be formed on the mask.
[0036]
In this case, the diameter of the opening may be 1/3 or less of the distance between the openings, and the diameter of the opening may be 1/10 or more of the distance between the openings.
[0037]
Also, in this case, the opening provided in the mask is square,
Create a table showing the relationship between the width of the two sides facing the opening and the interval between the openings, and the width of the recess formed corresponding to the width and the interval of the opening,
According to the above table, the width and the interval of the opening corresponding to the desired recess width may be formed on the mask.
[0038]
Further, in this case, the width of two opposing sides of the opening may be equal to or less than 1/3 of the distance between the openings, and the width of two opposing sides of the opening may be 1/10 of the distance between the openings. It may be the above.
[0039]
When the microstructure according to any of the microstructure forming methods of the present invention is used in a microlens array in which concave portions are continuously formed, the object to be etched is a glass substrate,
The mask may be composed of a metal film and an organic film sequentially formed on the glass substrate surface.
[0040]
In this case, the thickness of the metal film may be from 20 nm to 300 nm, and the thickness of the organic film may be from 200 nm to 4000 nm.
[0041]
In any of the above-described methods for forming a microstructure according to the present invention, a positioning member may be provided on the surface of the object to be etched, and a protective material for protecting the positioning member from an etching solution may be formed. The aligning means may be manufactured in the same step as the mask having the opening.
[0042]
Further, in any of the above-described methods for forming a fine structure of the present invention, the fine structure may be an optical waveguide pattern, or the fine structure may be a buried wiring pattern.
[0043]
In this case, the opening provided in the mask is square,
Create a table showing the relationship between the width of two opposite sides of the opening and the width of the recess formed corresponding to the width of the opening,
The width of the opening corresponding to the desired width of the concave portion may be formed on the mask according to the table.
[0044]
Further, in any of the above-described methods for forming a fine structure of the present invention, the fine structure may be a diffraction grating, and the fine structure may be a liquid crystal alignment film.
[0045]
Further, in the fine structure forming method of the present invention, the fine structure may be a polarizing optical element.
[0046]
In this case, the object to be etched may include at least one of aluminum, magnesium, calcium, potassium, strontium, barium, lithium, sodium, cesium, zinc, and lead. In this case, the etchant may contain hydrofluoric acid.
[0047]
Further, in any of the above-described fine structure forming methods of the present invention, the fine structure may be a microchip pattern.
[0048]
In this case, the opening provided in the mask is polygonal,
Create a table showing the relationship between the maximum width of the opening and the width of the recess formed corresponding to the maximum width of the opening,
According to the above table, the maximum width of the opening corresponding to the desired width of the concave portion may be formed on the mask.
[0049]
Also, in this case, the opening provided in the mask is square,
Create a table showing the relationship between the width of the two sides facing the opening and the interval between the openings, and the width of the recess formed corresponding to the width and the interval of the opening,
According to the above table, the width and the interval of the opening corresponding to the desired recess width may be formed on the mask.
[0050]
Further, the microlens array substrate of the present invention has a concave portion formed by any of the above-described microstructure forming methods of the present invention when the microstructure is used in a microlens array.
[0051]
Further, the microlens array master according to the present invention has, when a microstructure is used in a microlens array, a concave portion formed by any of the microstructure forming methods of the present invention.
[0052]
Further, the microlens array substrate of the present invention is provided with a positioning means by the above-described microstructure forming method of the present invention, and has a light shielding means.
[0053]
The microlens array matrix of the present invention for achieving the above object is a microlens array matrix having a concave portion,
The structure includes at least one of aluminum oxide, magnesium oxide, calcium oxide, potassium oxide, strontium oxide, barium oxide, lithium oxide, sodium oxide, cesium oxide, zinc oxide, and lead oxide. In this case, a columnar pattern may be provided around the lens.
[0054]
Further, the microlens array substrate of the present invention for achieving the above object is a microlens array substrate having a concave portion serving as a lens,
The structure includes at least one of aluminum oxide, magnesium oxide, calcium oxide, potassium oxide, strontium oxide, barium oxide, lithium oxide, sodium oxide, cesium oxide, zinc oxide, and lead oxide. In this case, a columnar pattern may be provided around the lens.
[0055]
In the microlens array substrate of the present invention, a material having a higher refractive index than the microlens array substrate may be embedded in the concave portion, or a transparent substrate may be provided on the concave portion forming surface side.
[0056]
Further, the microlens array substrate of the present invention may have a positioning means or a light shielding means.
[0057]
Further, a liquid crystal display element of the present invention uses the microlens array substrate of the present invention.
[0058]
In the liquid crystal display element of the present invention, the microlens array substrate and the substrate sandwiching the liquid crystal between the microlens array substrate may be a non-alkali glass or quartz substrate.
[0059]
Further, a liquid crystal display device of the present invention uses the above-mentioned liquid crystal display element of the present invention, and a liquid crystal projector of the present invention uses the above-mentioned liquid crystal display element of the present invention.
[0060]
(Action)
In the present invention, since the insolubles generated by the reaction between the substance contained in the object to be etched and the etching solution accumulate on the exposed surface of the object to be etched and stop the etching, the object to be etched is stopped after the etching is stopped. Etching does not proceed even if immersed in water. Therefore, even when a plurality of microstructures are formed on a large-area object to be etched, the generation of the insolubles is uniform on the exposed surface of the object to be etched, so that uniform etching can be performed on the surface. In addition, even when a plurality of workpieces are processed at one time, the generation of the insoluble material is uniform between the workpieces, so that uniform processing can be performed between the workpieces. Further, even when a single piece of the object is processed by a plurality of etching processes, the generation of the insolubles is uniform between the etching processes, so that the uniform processing can be performed between the etching processes.
[0061]
Further, in the present invention, instead of the insoluble material, a substance contained in the object to be etched, which does not dissolve in the etching solution, accumulates on the exposed surface of the object to be etched and stops the etching. Cause.
[0062]
In the present invention, an object to be etched containing at least one of aluminum oxide, magnesium oxide, calcium oxide, potassium oxide, strontium oxide, barium oxide, lithium oxide, sodium oxide, cesium oxide, zinc oxide, and lead oxide is provided. When etching is performed using an etching solution containing hydrofluoric acid, aluminum fluoride, magnesium fluoride, calcium fluoride, potassium fluoride, strontium fluoride, barium fluoride, lithium fluoride, and fluorine fluoride insoluble in the etching solution containing hydrofluoric acid. Since any of sodium fluoride, cesium fluoride, zinc fluoride, and lead fluoride is generated as the insoluble matter, these cause the same action as the insoluble matter.
[0063]
When an object to be etched containing at least one of calcium fluoride, sodium fluoride, barium fluoride, aluminum fluoride, strontium fluoride, and magnesium fluoride is etched with an etchant containing hydrofluoric acid, Since these substances do not dissolve in the etching solution containing hydrofluoric acid, they have the same effect as the above-mentioned insolubles.
[0064]
Further, in the present invention, since the microstructure is a microlens, the shape of the formed lens does not change even if the object to be etched is further immersed in the etchant after the etching is stopped by the insoluble matter. Therefore, there is no variation in the etching amount in each etching process, and a microlens having a uniform lens shape between the etching processes can be manufactured. In addition, even when a plurality of lenses are formed on a large substrate as an object to be etched, since the generation of the insolubles is uniform on the exposed surface of the substrate, a microlens having a uniform lens shape within the substrate surface can be manufactured. .
[0065]
Also, in the present invention, the mask is provided corresponding to the desired concave diameter by using a table showing the relationship between the diameter of the circular opening and the diameter of the concave formed corresponding to the diameter of the opening. The diameter of the opening is determined, and a desired concave portion can be formed on the surface of the object to be etched.
[0066]
Further, in the present invention, since the microstructure is used in the microlens array in which the concave portions are continuously formed, after the etching is stopped by the insoluble matter, the object to be etched is further immersed in the etchant. Also, the shape of the formed lens does not change. Therefore, there is no variation in the etching amount in each etching process, and a microlens array having a uniform lens shape between the etching processes can be manufactured. In addition, even when a microlens array is formed on a large substrate as an object to be etched, since the generation of the insolubles is uniform on the exposed surface of the substrate, it is possible to produce a microlens array having a uniform lens shape within the substrate surface. Become.
[0067]
Furthermore, since the insoluble matter generated during the progress of the etching also serves as a support for the mask, the mask is prevented from peeling.
[0068]
Further, in the present invention, by using a table showing the relationship between the diameter and interval of the circular opening and the diameter of the recess formed corresponding to the diameter and interval of the opening, it is possible to correspond to the desired recess diameter. Then, the diameter of the opening provided in the mask is determined, and a lens having a desired concave shape can be continuously formed on the surface of the object to be etched.
[0069]
In the case where the opening is rectangular, a table showing the relationship between the width of two opposing sides of the opening and the interval between the openings and the width of the opening and the width of the recess formed corresponding to the interval is used. Thus, similarly to the case of the circular shape, a lens having a desired concave shape can be continuously formed on the surface of the object to be etched.
[0070]
Regarding the diameter of the mask opening, if the diameter of the opening is too small, the etching stops in a state where the progress of the etching does not proceed sufficiently. On the other hand, if the diameter of the opening is too large, the adjacent opening pattern overlaps with the etching region before the etching stops, and the mask is peeled off.
[0071]
Further, in the present invention, since the diameter of the opening is set to 1/3 or less of the distance between the openings, it is possible to prevent the etching regions of the opening from being overlapped with each other and the mask from peeling off when the opening is too large. .
[0072]
Further, in the present invention, since the diameter of the opening is set to 1/10 or more of the distance between the openings, the phenomenon that the etching does not proceed sufficiently and the etching stops when the opening is too small is prevented.
[0073]
Note that the width of two opposing sides of the opening when the opening of the mask is square is the same as the diameter when the opening is circular.
[0074]
As for the material of the mask, it is preferable that the quality of the material is not easily changed by the etching solution and that the adhesion to the glass substrate to be etched is high. This is because when the adhesion is low, the etching proceeds from the interface between the glass substrate and the mask, which causes uneven etching.
[0075]
In the present invention, since the metal film having good adhesion to the glass substrate is formed on the surface of the glass substrate, the progress of etching from the interface between the glass substrate and the metal film is prevented. Further, since the organic film is formed on the surface of the metal film, penetration of the etchant into the surface of the glass substrate is prevented when the surface is damaged after the formation of the metal film.
[0076]
Further, in the present invention, the thickness of the metal film as a mask is set to a value of 20 nm to 300 nm so that a pinhole generated when the metal film is too thin and a crack generated when the metal film is too thick are not generated. Therefore, the penetration of the etching solution from the pinholes and cracks into the glass substrate is prevented.
[0077]
Further, in the present invention, since the thickness of the organic film is in the range of 200 nm to 4000 nm, when a minute flaw occurs on the surface of the metal film after the formation of the metal film and before the application of the resist, the etching solution from the flaw is removed. The film thickness is sufficient to prevent permeation, and more effectively prevents the permeation of the etchant into the glass substrate.
[0078]
In addition, in the present invention, since the etching is performed after forming the positioning means on the body to be etched and forming the protective material for protecting the positioning means, the shape change and peeling of the positioning means at the time of etching are prevented. Can be prevented. Therefore, using the alignment means after etching, it is possible to more accurately align with the mask at the time of exposure, to perform patterning with less deviation from the underlying pattern, and to perform overlaying with another substrate with high accuracy. Can be done.
[0079]
Further, in the present invention, the number of steps can be reduced by manufacturing the alignment means and the mask having an opening in the same step.
[0080]
Further, in the present invention, since the fine structure is an optical waveguide pattern, the shape of the formed pattern does not change even if the object to be etched is further immersed in the etchant after the etching is stopped by the insoluble material. Therefore, there is no variation in the amount of etching in each etching process, and it is possible to form an optical waveguide pattern having a uniform concave shape between the etching processes. Further, even when the object to be etched is a large-area substrate, the generation of the insolubles is uniform on the surface of the substrate, so that it is possible to form an optical waveguide pattern having a uniform concave shape.
[0081]
Further, in the present invention, since the microstructure is a buried wiring pattern, the shape of the formed pattern does not change even if the object to be etched is further immersed in an etching solution after the etching is stopped by the insoluble material. Therefore, there is no variation in the amount of etching in each etching process, and it is possible to form a buried wiring pattern having a uniform concave shape between the etching processes. Further, even when the object to be etched is a substrate having a large area, the generation of the insolubles is uniform on the exposed surface of the substrate, so that it is possible to form a buried wiring pattern having a uniform concave shape in the substrate surface.
[0082]
Further, in the present invention, by using a table showing the relationship between the width of two opposing sides of the rectangular opening and the width of the concave formed corresponding to the width of the opening, it is possible to correspond to the desired concave width. Thus, the width of the opening provided in the mask is determined, and a desired concave shape can be formed on the surface of the object to be etched.
[0083]
In the present invention, since the fine structure is a diffraction grating, the shape of the formed diffraction grating does not change even if the object to be etched is further immersed in an etching solution after the etching is stopped by the insoluble matter. Therefore, there is no variation in the amount of etching in each etching process, and it is possible to form a diffraction grating having a uniform pattern shape between the etching processes. Further, even when the object to be etched is a substrate having a large area, the generation of the insolubles is uniform on the substrate surface, so that a diffraction grating having a uniform pattern shape in the substrate surface can be formed.
[0084]
Further, in the present invention, since the fine structure is a liquid crystal alignment film, after the etching is stopped by the insoluble matter, the shape of the formed liquid crystal alignment film does not change even if the object to be etched is further immersed in an etchant. . Therefore, there is no variation in the amount of etching in each etching process, and a liquid crystal alignment film having a uniform pattern shape between the etching processes can be formed. Further, even when the liquid crystal alignment film is formed on a large-area object to be etched, since the generation of the insolubles is uniform on the exposed surface of the object to be etched, it is possible to form a liquid crystal alignment film having a uniform in-plane pattern shape. Become.
[0085]
In the present invention, since the microstructure is a polarizing optical element, after the etching is stopped by the insoluble matter, the shape of the formed polarizing optical element does not change even if the object to be etched is further immersed in an etching solution. . Therefore, there is no variation in the amount of etching in each etching process, and it is possible to form a polarizing optical element having a uniform pattern shape between the etching processes. In addition, even when the polarizing optical element is formed with a large-area object to be etched, since the generation of the insolubles is uniform on the exposed surface of the object to be etched, it is possible to form a polarizing optical element with a uniform in-plane pattern shape. Become.
[0086]
Furthermore, since the insolubles hinder the progress of the etching of the portion not covered by the mask, side etching of the object to be etched under the mask is prevented.
[0087]
Further, in the present invention, when the object to be etched containing at least one of aluminum, magnesium, calcium, potassium, strontium, barium, lithium, sodium, cesium, zinc, and lead is etched with an etching solution containing hydrofluoric acid, Aluminum fluoride, magnesium fluoride, calcium fluoride, potassium fluoride, strontium fluoride, barium fluoride, lithium fluoride, sodium fluoride, cesium fluoride, zinc fluoride, which are insoluble in the etching solution containing hydrofluoric acid Since either one of lead and lead fluoride is produced as the above-mentioned insoluble matter, these cause the same action as the above-mentioned insoluble matter.
[0088]
Further, in the present invention, since the microstructure is a microchip pattern, the shape of the microchip pattern formed even after the etching is stopped by the insoluble material and the object to be etched is further immersed in an etching solution. It does not change. Therefore, there is no variation in the amount of etching in each etching process, and it is possible to form a microchip pattern having a uniform concave shape between the etching processes. Further, even when the object to be etched is a substrate having a large area, the generation of the insolubles is uniform on the exposed surface of the substrate, so that a microchip pattern having a uniform concave portion in the substrate surface can be formed.
[0089]
Further, in the present invention, by using a table showing the relationship between the maximum width of the polygonal opening and the width of the recess formed corresponding to the maximum width of the opening, it is possible to correspond to the desired recess width. Thus, the width of the opening provided in the mask is determined, and a desired concave shape can be formed on the surface of the object to be etched.
[0090]
Further, in the present invention, a table showing a relationship between the width of two opposing sides of the rectangular opening and the interval between the openings and the width of the concave portion formed corresponding to the width of the opening and the interval is used. Thereby, the width and the interval of the openings provided in the mask corresponding to the desired recess width are determined, and the desired recess shape can be continuously formed on the surface of the object to be etched.
[0091]
Further, in the microlens array substrate of the present invention, since the lens shape is uniform in the substrate plane, the distance from the substrate to the focal point of the microlens in the substrate plane becomes uniform.
[0092]
Further, since the concave shape of the microlens array matrix of the present invention is uniform in the substrate surface, the lens shape of the microlens array substrate manufactured by molding using this matrix is uniform in the substrate surface.
[0093]
In addition, the microlens array substrate of the present invention is exposed after being aligned with the mask with higher precision using the alignment means, and the light shielding means is formed by patterning, so that the overlapping margin of the light shielding means is reduced. It is possible to do. Therefore, if a liquid crystal display element is manufactured using this microlens array substrate, the aperture ratio can be increased and a brighter display can be realized.
[0094]
In addition, since the microlens array master of the present invention has a columnar pattern around the lens, when an etching mask is formed on the columnar pattern, the etching solution does not peel off the etching mask. The columnar pattern is prevented, and the lens shape becomes uniform in the plane of the substrate.
[0095]
In addition, since the microlens array substrate of the present invention has a columnar pattern around the lens, when an etching mask is formed on the columnar pattern, the etching liquid peels off the etching mask. Is prevented, and the lens shape becomes uniform in the substrate plane.
[0096]
In the microlens array substrate of the present invention, since a material having a higher refractive index than the microlens array substrate is embedded in the concave portion functioning as a lens, the focus of the microlens is adjusted by adjusting the refractive index of the refractive index material. The distance can be adjusted.
[0097]
In addition, the microlens array substrate of the present invention has a transparent substrate on the side of the concave portion forming a function as a microlens array, whereby the shape of the refractive index material embedded in the concave portion is maintained, and light refracted by the concave portion is transparent. It can pass through the substrate. Further, the focal length of the microlens can be adjusted by adjusting the thickness of the transparent substrate.
[0098]
Further, since the microlens array substrate of the present invention has a positioning means, it is possible to perform more precise positioning of a pattern formed on the microlens array substrate.
[0099]
In addition, since the microlens array substrate of the present invention has the light shielding means, when the TFT substrate is overlaid on the microlens array substrate, light hitting the TFT can be reduced.
[0100]
Further, since the liquid crystal display device of the present invention uses a microlens array substrate having a uniform lens shape in the substrate surface, the luminance in the device surface becomes uniform.
[0101]
Further, in the liquid crystal display element of the present invention, since the substrate sandwiching the liquid crystal between the microlens array substrate and the microlens array substrate is an alkali-free glass substrate or a quartz substrate, both have the same thermal expansion coefficient, Substrate peeling and misalignment caused when the linear thermal expansion coefficients of two substrates are significantly different are suppressed, and the reliability is further improved.
[0102]
Further, since the liquid crystal display device of the present invention includes a liquid crystal display element using a microlens array substrate having a uniform lens shape in the substrate plane, the luminance on the display screen becomes uniform.
[0103]
Further, since the liquid crystal projector of the present invention includes a liquid crystal display element using a microlens array substrate having a uniform lens shape in the plane of the substrate, the brightness of the entire projected image becomes uniform.
[0104]
BEST MODE FOR CARRYING OUT THE INVENTION
The present invention provides an etching solution that reacts with a substance contained in an object to be etched to generate an insoluble substance, or an etching solution that does not dissolve some substances contained in an object to be etched, thereby producing the insoluble substance. Or the above-mentioned part of the material is leached to stop the etching.
[0105]
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0106]
(1st Embodiment)
The first embodiment is a mode in which the present invention is applied to the production of a microlens array by isotropic etching.
[0107]
FIG. 1 is a sectional view showing a first embodiment of the present invention in the order of manufacturing steps.
[0108]
As the substrate 1, a 0.7 mm thick non-alkali glass substrate having a composition ratio of silicon oxide of 49%, aluminum oxide of 10%, boron oxide of 15%, and barium oxide of 25% is prepared. After cleaning the substrate 1, a metal film 2 made of a chromium layer having a thickness of 100 nm is formed on the substrate 1 by using a sputtering method. Next, a resist 3 having a thickness of 1000 nm is formed on the metal film 2 by using a spin coating method. As the resist 3, a positive resist was used. By exposing and developing the resist 3 using a stepper exposure machine, a plurality of circular openings 3a having a diameter of 3 μm are formed at a pitch of 30 μm.
[0109]
Next, the metal film 2 is etched using a known chromium etchant containing ceric ammonium nitrate as a main component, and the metal film 2 is processed into a shape similar to the shape of the opening 3 a of the resist 3. (FIG. 1A). Here, the resist 3 is left as an etching mask without being stripped. By leaving the resist 3, if a minute flaw occurs on the surface of the metal film after the formation of the metal film and before the application of the resist, the influence on the substrate 1 due to the penetration of the etching solution from the flaw can be reduced. is there.
[0110]
In addition, if the back surface and the end surface of the substrate 1 are protected by being covered with a protective material such as a protective tape or an epoxy resin material (not shown), the metal film 2 or the resist 3, the thickness and the size of the substrate 1 by etching can be reduced. Changes can be reduced.
[0111]
Next, the substrate 1 is immersed in a 10% hydrofluoric acid aqueous solution to be the etchant 4 for 20 minutes to etch the substrate 1.
[0112]
FIG. 1B is a cross-sectional view showing an initial stage of etching.
[0113]
When the etching is started, the isotropic etching of the substrate 1 proceeds from the opening 3a, and a small semi-spherical hollow centered on the opening 3a is generated. As a result of the etching, aluminum fluoride and barium fluoride, which are insolubles 5 with respect to the etchant 4, are mainly generated on the surface of the substrate in the minute recess. The insoluble matter 5 is generated by a reaction between aluminum oxide and barium oxide uniformly contained in the substrate 1 and hydrofluoric acid contained in the etchant 4.
[0114]
The insoluble matter 5 accumulates in the depression as the etching proceeds, covers the substrate surface in the depression, and inhibits the circulation of the etchant 4. For this reason, the progress of the etching of the substrate 1 was gradually hindered, the etching was stopped in about 15 minutes, and thereafter, the etching did not progress. FIG. 1C is a cross-sectional view showing this state.
[0115]
After that, the shape of the depression does not change regardless of the etching time. In the present embodiment, the etching is stopped when the etched region has advanced to a state where the etched region overlaps the adjacent lens. When focusing on one lens, the columnar patterns 1a are formed at four places around the lens.
[0116]
Thereafter, when the resist 3 is peeled off using acetone and the metal film 2 is peeled off using the chromium etching solution, the insoluble matter 5 containing aluminum fluoride as a main component is washed away from the depression. Further, when the protective material (not shown) is provided on the back surface and the end surface of the substrate 1, the protective material (not shown) is peeled off to form a plurality of hemispherical lenses having a diameter of about 40 μm at a pitch of 30 μm. The obtained microlens array substrate 12 is obtained (FIG. 1D).
[0117]
In the present embodiment, as described above, the substrate 1 is an object to be etched that uniformly contains aluminum oxide and barium oxide, which are substances that react with the etchant 4 and generate the insoluble matter 5 with respect to the etchant 4. The etchant 4 is an etchant that reacts with aluminum oxide and barium oxide contained in the substrate 1 to generate an insoluble matter 5 for the etchant 4. As a combination of the substrate 1 and the etchant 4, the substrate 1 includes alkali-free glass, low-alkali glass, borosilicate glass, lead glass, β-quartz transparent crystallized glass, and the like. Glass containing at least one of calcium oxide, potassium oxide, strontium oxide, barium oxide, lithium oxide, sodium oxide, cesium oxide, zinc oxide, and lead oxide can be used. The etchant 4 may be a hydrofluoric acid-based etchant such as hydrofluoric acid, buffered hydrofluoric acid obtained by adding ammonium fluoride to hydrofluoric acid, or hydrofluoric-nitric acid etchant obtained by adding nitric acid or the like to hydrofluoric acid.
[0118]
As the insoluble matter 5, magnesium oxide, calcium oxide, strontium oxide, lithium oxide, sodium oxide, cesium oxide, zinc oxide, and lead oxide react with hydrofluoric acid in addition to the aluminum fluoride and barium fluoride. , Magnesium fluoride, calcium fluoride, strontium fluoride, lithium fluoride, sodium fluoride, cesium fluoride, zinc fluoride, and lead fluoride.
[0119]
Further, the combination of the substrate 1 and the etchant 4 may be such that the etchant 4 does not dissolve some substances contained in the substrate 1. In such a combination, oxyhalide glass can be used as the substrate 1, and the above-mentioned hydrofluoric acid-based etching solution can be used as the etchant 4. Substances that do not dissolve in the hydrofluoric acid-based etchant include calcium fluoride, sodium fluoride, barium fluoride, aluminum fluoride, strontium fluoride, and magnesium fluoride. Since the substrate 1 contains at least one substance that does not dissolve in the etchant 4, the substance that does not dissolve in the etchant 4 covers the surface of the substrate 1 as the etching of the substrate 1 progresses, and The same operations and effects as those described above are produced.
[0120]
In practicing the present invention, the opening diameter of the etching mask is an important factor for the following reasons. If the diameter of the opening is too small, the etching stops because the circulation of the etchant 4 is hindered by the influence of the insoluble matter 5 in a state where the progress of the etching does not proceed sufficiently. If the diameter of the opening is too large, the circulation of the etchant 4 becomes difficult to be hindered. Therefore, the etching region overlaps with the adjacent microlens before the etching is stopped by the insoluble matter 5, and the etching mask is peeled off, so that the etching is stopped. Will not stop. Even when the pitch of the openings is too small, the adjacent microlens and the etching region overlap before the etching is stopped, and the etching mask is separated.
[0121]
From the above, a number of experiments were performed while changing the opening diameter and the opening pitch of the etching mask, and the results will be described.
[0122]
Table 1 summarizes the results of etching performed under the above manufacturing conditions while changing the diameter of the circular opening and the pitch of the opening. In addition, the mark ○ in Table 1 indicates that the progress of etching was stopped in a predetermined state. Further, the mark “x” indicates that the progress of the etching did not stop, and the mark “*” indicates that the etching was stopped in a state where the progress of the etching did not proceed sufficiently.
[0123]
[Table 1]

[0124]
From the results shown in Table 1, it is clear that the object of the present invention is achieved when the size of the opening diameter is in the range of 1/10 to 1/3 of the pitch of the opening.
[0125]
In addition, the diameter of the microlens obtained by the circles shown in Table 1 ranges from the size of the state where the adjacent lenses are in contact with each other to the state where the etching areas of the adjacent lenses overlap but the etching mask does not peel off. The size was 1.0 to 1.4 times the opening pitch shown in Table 1. From these results, by using Table 1, the pitch of the openings and the diameter of the openings can be determined from the diameter of the microlens to be manufactured. For example, in order to manufacture a microlens array having a lens diameter of 30 to 40 μm, it can be seen from Table 1 that if the pitch of the openings is 30 μm, the diameter of the openings should be 3 to 10 μm.
[0126]
Also, a number of experiments were carried out when the shape of the opening was a square instead of a circle, and the results will be described.
[0127]
Table 2 summarizes the state after etching by changing the side length of the opening, which is the length of one side of the square, and the pitch of the opening. The meaning of each mark shown in Table 2 is the same as in Table 1 above.
[0128]
[Table 2]

[0129]
From the results shown in Table 2, it is clear that the object of the present invention is achieved when the opening side length is in the range of 1/10 to 1/3 of the pitch of the opening. Thus, it has been found that the present invention does not largely depend on the shape of the opening. Therefore, the shape of the opening 3a of the etching mask is circular in this embodiment, but may be square, elliptical, or another shape.
[0130]
Next, in order to examine the dependence on the etchant concentration, etching was performed while changing the concentration of the hydrofluoric acid aqueous solution, and the results will be described.
[0131]
Table 3 summarizes the etching time when the concentration of the hydrofluoric acid aqueous solution was 5%, 10%, 20%, and 30% when an etching mask having an opening pitch of 30 μm and an opening diameter of 3 μm was provided. Things. The etching time means a time until the progress of the etching is automatically stopped by the influence of the insoluble matter 5.
[0132]
[Table 3]

[0133]
From the results shown in Table 3, the higher the concentration of hydrofluoric acid, the shorter the time until the etching stops. When the lens shape obtained under each etching condition was observed, it was found that almost the same shape was obtained under any condition. This suggests that the present invention does not largely depend on the concentration of the etchant 4. That is, even if the etchant concentration slightly changes and the time until the etching stops varies due to the change, the etching is automatically stopped by the insoluble matter 5, so that over-etching does not occur. In addition, by setting a time longer than a predetermined etching time in advance, it is possible to prevent insufficient etching.
[0134]
Regarding the concentration of the impurity contained in the substrate 1 which is a substance that does not dissolve in the etchant 4, even if the etchant concentration is the same, if the impurity concentration is high, the etching stops quickly, and if the impurity concentration is low, , The generation of insolubles is insufficient, so that the stop of the progress of etching tends to be delayed. Therefore, the diameter of the formed lens is affected by the impurity concentration of the substrate 1. For this reason, it is preferable that the concentration of impurities such as aluminum oxide contained in the substrate 1 be constant within the substrate and between the substrates.
[0135]
Next, in order to examine the dependence of the etchant 4 on the temperature, etching was performed while changing the temperature of the hydrofluoric acid aqueous solution, and the results will be described.
[0136]
Table 4 summarizes the results of examining the etching time while changing the etchant temperature while fixing the hydrofluoric acid concentration in the etchant to 10%. In addition, this etching time means the time until the progress of the etching is stopped in the same manner as in Table 3 above.
[0137]
[Table 4]

[0138]
From the results shown in Table 4, the higher the temperature of the etchant, the shorter the time until the etching stops. In addition, when the lens shape obtained under each etching condition was observed, it was found that a similar shape was obtained under any condition. This means that the present invention does not largely depend on the temperature of the etchant, and strict temperature control is not required. Further, as in the case where the concentration is changed, strict time management is not required, and it is possible to prevent insufficient etching and over-etching.
[0139]
Next, the results of study on the etching mask will be described below.
[0140]
As for the material of the etching mask, it is preferable that the etching mask 4 hardly deteriorates and that the adhesion to the substrate 1 is high. This is because when the adhesion is low, the etching proceeds from the interface between the substrate 1 and the etching mask, which causes uneven etching. The metal film 2 such as the chromium layer as in the present embodiment is hardly deteriorated by the hydrofluoric acid-based etchant and has good adhesion to the substrate 1.
[0141]
Next, the result of study on the thickness of the chromium layer used for the metal film 2 of the etching mask will be described below.
[0142]
Table 5 summarizes the etching results when the thickness of the chromium layer was changed between 10 nm and 500 nm.
[0143]
[Table 5]

[0144]
As shown in Table 5, when the thickness of the chromium layer is 10 nm or less and 500 nm or more, the chromium layer cannot be used as a mask, for the following reasons.
[0145]
When the thickness of the chromium layer is 10 nm or less, pinholes are generated in the chromium layer, and the function as an etching mask cannot be sufficiently exhibited. Therefore, peeling of the etching mask occurs to obtain a good etching state. Could not. Further, when the thickness of the chromium layer is 500 nm or more, many cracks are generated, and peeling which is considered to be caused by the stress of the chromium layer occurs as the etching proceeds, so that a good etching state may be obtained. could not. For this reason, the thickness of the chromium layer in the present invention is preferably set in a range from 20 nm to 300 nm. In addition, silicon, titanium, silver, platinum, gold, or the like can be used instead of chromium. However, since the same phenomenon as in the case of chromium occurs, it is preferable to use chromium in the above range.
[0146]
Next, the result of studying the thickness of the resist 3 of the etching mask will be described below.
[0147]
Table 6 summarizes the etching results when the thickness of the resist 3 was changed between 100 nm and 6000 nm.
[0148]
[Table 6]

[0149]
As shown in Table 6, when the thickness of the resist 3 is 100 nm or less and when it is 6000 nm or more, the resist 3 cannot be used as a mask, for the following reasons.
[0150]
When the thickness of the resist 3 was 100 nm or less, the etching mask was peeled off with the progress of etching, and a good etching state could not be obtained. In addition, even when the thickness of the resist 3 was 6000 nm or more, the etching mask was peeled off with the progress of etching, and a favorable etching state could not be obtained. For this reason, the thickness of the resist 3 in the present invention is preferably set in a range from 200 nm to 4000 nm.
[0151]
Note that the present embodiment can be similarly applied to formation of a single microlens as well as a microlens array.
[0152]
In the present embodiment, as described above, the etching of the substrate 1 is automatically stopped by the generation of the insoluble matter 5, so that the etching proceeds even if the substrate 1 is immersed in the etchant 4 after the etching is stopped. do not do. Therefore, it is possible to secure a large margin for removing the substrate 1 from the etchant 4 after the etching is stopped.
[0153]
Further, even when processing a plurality of substrates 1 at a time, the generation of the insoluble matter 5 is uniform between the substrates, so that uniform processing between the substrates is possible. Further, even when one substrate 1 is processed by a plurality of etching processes, since the generation of the insoluble matter 5 is uniform between the etching processes, the uniform processing can be performed between the etching processes. Therefore, even if the substrate 1 becomes large and an in-plane distribution occurs in the etchant concentration or the etching time, a uniform lens pattern can be formed not only in the substrate surface but also between the substrates, and the concave portion in the substrate surface and between the substrates can be formed. The yield is improved by the uniformity of the shape, and the cost can be reduced by wet etching.
[0154]
Further, since the generated insoluble matter 5 plays a role of supporting the etching mask, it is possible to prevent the etching mask composed of the metal film 2 and the resist 3 from being peeled off, and to perform processing with higher uniformity. Become. Furthermore, glass for liquid crystal display such as non-alkali glass, low alkali glass, borosilicate glass, and lead glass is inexpensive as compared with a quartz glass substrate or a silicon wafer substrate. Can be used, so that cost reduction can be realized.
[0155]
The case where the microlens array substrate 12 according to the present embodiment is applied to a liquid crystal display device will be described.
[0156]
FIG. 2 is a perspective view schematically showing the appearance of the liquid crystal display element.
[0157]
As shown in the figure, the liquid crystal display element has a configuration in which a liquid crystal layer 52 is sandwiched between an adjustment glass plate 51 provided on a microlens array substrate 12 and a TFT substrate 50 manufactured by a known method. .
[0158]
In the liquid crystal display device having the above configuration, light emitted from the lower side of the figure is configured to be condensed at the transmission part of the TFT substrate 50 by the microlens provided on the microlens array substrate 12, so that the light is The brightness of the portion where the liquid crystal molecules are arranged so as to be transmitted is increased. Further, by using the microlens array substrate 12 of the present embodiment, the luminance on the display surface becomes uniform.
[0159]
A method for manufacturing the above liquid crystal display element will be described.
[0160]
3 to 5 are cross-sectional views showing a method for manufacturing a liquid crystal display device in the order of manufacturing steps.
[0161]
As shown in FIG. 3A, a metal film 202 and a resist 203 are sequentially formed on a non-alkali glass substrate 201, and an opening 203a is formed in the resist 203 and the metal film 202 by a known lithography process and an etching process. . When forming the opening 203a, an exposure position adjustment marker 203b described below is formed. In FIG. 1, the illustration of the exposure position adjustment marker 203b is omitted.
[0162]
The required number of exposure position adjustment markers 203b are provided at predetermined locations on the substrate 201. At the time of the first exposure for forming the opening 203a by the stepper exposure machine and the subsequent exposure performed by the stepper exposure machine, the exposure position adjustment marker 203b is positioned relative to a reticle or a TFT substrate which is a mask for the stepper exposure machine. Positioning means used for accurate positioning, and generally has an accuracy of 1 μm or less. Although the number of steps increases, the opening 203a may be formed after the exposure position adjustment marker 203b is formed.
[0163]
Subsequently, as shown in FIG. 3B, before immersing the substrate 201 in the etchant, a protective material 253 for protecting the exposure position adjustment marker 203b from the etchant is formed. The protective material 253 only needs to have resistance to an etchant, and particularly, a protective tape, an epoxy resin material, or the like can be suitably used as the protective material 253.
[0164]
Then, as shown in FIG. 3C, the substrate 201 is immersed in an etchant and the substrate 201 is etched. At this time, the protective material 253 prevents the shape change and peeling of the exposure position adjustment marker 203b. In addition, since the columnar pattern 201a is provided around the concave portion serving as a lens, separation of the resist 203 and the metal film 202 is prevented.
[0165]
Thereafter, as shown in FIG. 3D, the protective material 253 is peeled off, and the resist 203 and the metal film 202 other than the exposure position adjustment marker 203b are peeled off. Here, the protective material 253 is peeled off, but it is not necessary to peel off the protective material 253 if there is no problem in the subsequent stepper exposure by the stepper exposure machine.
[0166]
Subsequently, as shown in FIG. 3E, a high refractive index adhesive 254 is applied to the concave portion forming surface of the microlens array substrate 212, and a transparent glass plate 251 for adjustment is bonded. At this time, the focal length of the lenses of the microlens array is adjusted, and the thickness of the adjusting glass plate 251 is adjusted so that the effect as a lens is maximized. After the glass plate 251 for adjustment is attached to the microlens array substrate 212, the glass plate 251 for adjustment may be thinned to adjust the thickness. You may paste. When thinning after bonding, an etching method or a mechanical polishing method can be suitably used. By bonding the glass plate 251 for adjustment as a transparent substrate to the surface on which the concave portions are formed, the shape of the high refractive index adhesive 254 embedded in the concave portions is maintained, and the light refracted by the concave portions is adjusted by the lath plate for adjustment. 251 can be transmitted.
[0167]
Thereafter, a thin film of chromium, aluminum, or the like is formed on the glass plate 251 for adjustment, and a resist is applied thereon. Then, the reticle and the microlens array substrate 212 are positioned using the marker provided on the reticle for forming the pattern of the superposition position adjustment marker 255 and the pixel light-shielding portion 256 and the exposure position adjustment marker 203b. Exposure and development are performed. Subsequently, an overlay position adjustment marker 255 and a pixel light shielding portion 256 are formed by patterning to form a pattern conforming to the shape of the resist mask by etching (FIG. 3F).
[0168]
As described above, the exposure position adjustment marker 203b is used for positioning the reticle and the microlens array substrate 212 during stepper exposure. Therefore, the superposition position adjustment marker 255 and the pixel light shielding portion 256 can be more accurately arranged at desired positions. The overlay position adjustment marker 255 is used to overlay the TFT substrate used for manufacturing a liquid crystal display element with high accuracy. Since the superposition with the TFT substrate can be performed with high accuracy, the superposition margin of the pixel light-shielding portion 256 and the like can be made smaller, the aperture ratio becomes higher, and a liquid crystal display element capable of brighter display can be manufactured. The pixel light-shielding portion 256 is light-shielding means for preventing light from shining on a TFT or the like.
[0169]
Thereafter, a transparent electrode, an alignment film, and the like, not shown, are formed on the glass plate 251 for adjustment by a known method.
[0170]
Instead of bonding using the above high refractive index adhesive, a high refractive index material is embedded in the formed concave portion, and the microlens array substrate is formed using an adhesive having substantially the same refractive index as the adjusting glass plate 251. 212 and the glass plate 251 for adjustment may be bonded. Further, by adjusting the refractive index of the high refractive index adhesive and the high refractive index material, it is possible to adjust the focal length of the lenses of the microlens array.
[0171]
Next, a method of superposing the TFT substrate and the microlens array substrate will be described. There are roughly two superposition methods. The first method is to cut the TFT substrate and the microlens array substrate into individual pieces after superimposing the TFT substrate and the microlens array substrate, and the second method is to cut the TFT substrate and the microlens array substrate into individual pieces and then superimpose them. Is the way.
[0172]
First, the first overlapping method will be described.
[0173]
FIG. 4 is a schematic cross-sectional view showing the first superposition method.
[0174]
The microlens array substrate 212 shown in FIG. 3F is prepared (FIG. 4A). Subsequently, as shown in FIG. 4 (B), the TFT substrate 250 and the microlens array substrate 212 manufactured by a known method are used, and a superposition position adjustment marker 255 and a TFT substrate side superposition position adjustment marker 257 are used. And stick them together with a sealant 258. At this time, a gap is provided between the TFT substrate 250 and the microlens array substrate 212 for receiving liquid crystal. When the exposure position adjustment marker 203b is formed, a superposition position adjustment marker may be formed on the surface of the microlens array substrate 212, and the superposition position adjustment marker may be used when superimposing the TFT substrate 250. .
[0175]
Subsequently, as shown in FIG. 4C, the bonded TFT substrate 250 and the microlens array substrate 212 are separated into individual pieces by a cutting method in which high-pressure water is applied to the cut portion, and the two bonded substrates are separated. Liquid crystal is sealed between the plates to form a liquid crystal layer 252, thereby obtaining a liquid crystal display element 260. According to this cutting method, it is possible to efficiently cut even a structure in which the microlens array substrate 212 and the adjustment glass plate 251 are bonded with the high refractive index adhesive 254. Note that the liquid crystal layer 252 may be sealed when the TFT substrate 250 and the microlens substrate 212 are bonded to each other.
[0176]
Next, a second overlapping method will be described.
[0177]
FIG. 5 is a schematic sectional view showing a second method of superimposing.
[0178]
As shown in FIG. 5A, the microlens array substrate 212 is cut into individual pieces. An overlapping position adjustment marker 255 is also formed on the individual microlens array substrate 212a. Subsequently, as shown in FIG. 5B, the individualized TFT substrate 250a and the individualized microlens array substrate 212a are used by using the superposition position adjustment marker 255 and the TFT substrate side superposition position adjustment marker 257. And align them with each other, and attach them with a sealant 258. Liquid crystal is sealed between the two bonded plates to form a liquid crystal layer 252, and a liquid crystal display element 260 is obtained.
[0179]
In FIGS. 4 and 5, an adjustment glass substrate 251 is attached to the concave lens formation surface side of the microlens array substrate 212, and a liquid crystal layer 252 is formed between the adjustment glass substrate 251 and the TFT substrate 250. As described above, a liquid crystal layer 252 may be formed between the microlens array substrate 212 and the TFT substrate 250.
[0180]
FIG. 6 is a sectional view showing another configuration example of the liquid crystal display element.
[0181]
The vertical direction of the individualized microlens array substrate 212a shown in FIG. 5 is reversed so that the lens of the individualized microlens array substrate 212a has an upwardly convex shape as shown in FIG. ing. In forming the structure shown in FIG. 6, the thickness of the individual microlens array substrate 212a is adjusted so that the effect of the lens is maximized. The thickness of the microlens array substrate 212 may be adjusted after the adjustment glass 251 is attached to the concave surface of the microlens array substrate 212, but the thickness of the microlens array substrate 212 is adjusted beforehand. The glass plate 251 for use may be bonded. When thinning after bonding, an etching method or a mechanical polishing method can be suitably used.
[0182]
It is preferable that the TFT substrate and the microlens array substrate of the liquid crystal display element have relatively close linear thermal expansion coefficients which are thermal expansion coefficients per unit length. If these two substrates have greatly different coefficients of linear thermal expansion, problems such as a decrease in reliability due to peeling of the substrate in a heat cycle and misalignment due to thermal expansion become problems. A non-alkali glass or quartz substrate is often used for the TFT substrate. At this time, the linear thermal expansion coefficient between the TFT substrate and the microlens array substrate is increased by using non-alkali glass or β-quartz transparent crystallized glass for the microlens array substrate according to the type of the TFT substrate. As a result, the occurrence of the above problem is suppressed, and the reliability is further improved.
[0183]
Next, a case where the produced liquid crystal display element is applied as a liquid crystal light valve of a liquid crystal projector will be described.
[0184]
FIG. 7 is a schematic diagram illustrating a configuration example of a liquid crystal projector.
[0185]
As shown in the figure, the liquid crystal projector includes a light source 130, a polarization conversion integrator 132 for aligning the polarization directions of the light from the light source 130 and making the light intensity uniform, and dichroic mirrors 133 and 134 for white light from the light source 130. A color separation optical system for separating light beams of three colors of red, green, and blue; total reflection mirrors 135 to 137 for changing the traveling direction of the separated light beams; A liquid crystal display element 138 to 140, a color synthesizing optical system including a cross dichroic prism 141 for synthesizing images displayed by the three liquid crystal display elements 138 to 140, and a synthesized display image on a screen. And a projection lens 142 for enlarged projection.
[0186]
The liquid crystal display elements 138 to 140 are of an active matrix type in which thin film transistors (TFTs) are arranged for each pixel to drive liquid crystal. A polarizing plate (not shown) whose polarization direction is orthogonal to the polarization direction of the polarization conversion integrator 132 is provided on the surface of the liquid crystal display elements 138 to 140 on the side of the cross dichroic prism 141.
[0187]
Next, the operation of the liquid crystal projector having the above configuration will be described.
[0188]
As shown in the figure, the liquid crystal projector collects light emitted from the light source 130 with a reflector 131, separates a red light beam from the light beam with a dichroic mirror 133, and separates a green light beam with a dichroic mirror 134. And separates the light into red, green and blue light beams. The red light flux is reflected by the total reflection mirror 135, and then illuminates the red liquid crystal display element 138. The green light flux illuminates the green liquid crystal display element 139, and the blue light flux is sequentially reflected by the total reflection mirrors 136 and 137, and then illuminates the blue liquid crystal display element 140. The images displayed on the red, green, and blue liquid crystal display elements 138 to 140 are synthesized by a cross dichroic prism 141, and then enlarged and projected on a screen (not shown) by a projection lens 142.
[0189]
In the liquid crystal projector having the above configuration, since the light incident on the microlens is focused on the opening of the pixel, the brightness is improved and the projected image on the screen becomes brighter, and the microlens array substrate 12 of the present invention is used. This makes the overall brightness of the projected image uniform.
[0190]
Next, a case where the liquid crystal display element is applied to a liquid crystal display device will be described.
[0191]
FIG. 8 is a perspective view schematically showing the appearance of a transflective liquid crystal display device.
[0192]
As shown in the figure, the liquid crystal display device includes the liquid crystal display element 151, polarizing plates 152 and 153, a backlight unit 154 serving as a light source, and a signal supply circuit for sending a signal to a TFT provided for each pixel. 155, and a power supply unit 156 that supplies power to the backlight unit 154 and the signal supply circuit 155.
[0193]
The backlight unit 154 is provided with lamps of three primary colors of red, green, and blue, and by controlling the lighting of the three primary color lamps at high speed, the screen of the liquid crystal display device can be displayed in color. Instead of providing the three primary color lamps in 154, a color filter may be provided in the liquid crystal display element 151.
[0194]
In the liquid crystal display device having the above-described configuration, the display becomes brighter because the microlens array increases the light utilization rate of the backlight, and the luminance in the display screen becomes uniform by using the microlens array substrate 12 of the present invention.
[0195]
The liquid crystal display device according to the present embodiment can be used in, for example, a transflective liquid crystal display device disclosed in JP-A-2000-298267.
[0196]
In addition, the liquid crystal display element manufactured according to the present embodiment is not limited to the above-mentioned transflective liquid crystal display device, but may be a fine transmissive type having a larger light blocking ratio than the transflective type, and a fine reflective type having a smaller light blocking ratio than the semi-transmissive type. The present invention can also be applied to a liquid crystal display device.
[0197]
(Second embodiment)
In the second embodiment, the microlens array substrate 12 manufactured according to the first embodiment is used as a matrix for manufacturing a microlens array by a 2P molding method.
[0198]
FIG. 9 is a cross-sectional view showing a second embodiment of the present invention in the order of manufacturing steps.
[0199]
First, as shown in FIG. 9A, a release agent 7 and an ultraviolet curable resin as the resin 8 are sequentially applied to the concave forming surface of the mother die 6, and the surface on which the resin 8 is applied faces downward. .
[0200]
Next, using non-alkali glass as the substrate 30, the surface of the substrate 30 and the surface of the resin 8 are aligned, and the matrix 6 is pressed against the substrate 30 (FIG. 9B). After the resin 8 is cured by irradiating ultraviolet rays, the mother die 6 is peeled off to form the resin 8 formed into a convex shape on the substrate 30, and the microlens array 32 composed of the resin 8 and the substrate 30 is formed. Is obtained (FIG. 9C).
[0201]
After the step illustrated in FIG. 9C, anisotropic etching may be performed on the entire surface of the resin 8 to transfer the convex shape of the resin 8 to the substrate 30.
[0202]
Further, the resin 8 is preferably a photocurable resin that cures by light irradiation, a thermosetting resin that cures by heating, or a two-component adhesive. As the material of the matrix 6, it is preferable to use the same material as the substrate 30 or a material having a thermal expansion coefficient close to that of the substrate 30.
[0203]
In this embodiment, since the microlens array substrate 12 of the first embodiment is formed with a uniform concave shape over a large area, the microlens array substrate 12 is used for The mold can be manufactured at a high yield at a low cost.
[0204]
In addition, by using the same type of material or a material having a similar thermal expansion coefficient for the matrix 6 and the substrate 30, a material different from the substrate 30 such as a metal or a quartz glass substrate is used as the material for the matrix 6. In addition, an error caused by a difference in thermal expansion coefficient can be reduced, and strict temperature control is not required. In addition, it is possible to reduce an error generated in the heating step when using a thermosetting resin.
[0205]
Furthermore, as a material for the matrix 6 and the substrate 30, inexpensive alkali-free glass or the like can be used, so that cost reduction can be achieved. In addition, since the microlens array 32 can be molded by using the large master block 6, it is not necessary to perform stamping with a small master block many times with high accuracy, which is advantageous in terms of cost.
[0206]
When the microlens array 32 manufactured according to the present embodiment is used as a microlens array for a light valve of a liquid crystal projector, the following steps are added.
[0207]
First, an adhesive having a lower refractive index than that of the resin 8 or the substrate 30 is applied to the convex molding surface of the microlens array 32, and glass is bonded. Next, after adjusting the thickness of the glass so that the focus of the lens formed on the convex portion of the microlens array 32 matches the transmission portion of the TFT substrate manufactured by a known method, the TFT substrate is moved to the microlens array. 12 to obtain a microlens array for a light valve.
[0208]
Thereafter, a transparent electrode serving as a wiring and a marker for alignment are formed on the microlens array for a light valve, and a known panel manufacturing process is performed, whereby a light valve with a microlens array for a liquid crystal projector is formed. obtain.
[0209]
Further, in order to apply the microlens array 32 manufactured according to the present embodiment to a liquid crystal display device with a microlens array, the following steps may be performed. In addition, as an application example of the liquid crystal display device with a microlens array, there is a liquid crystal display device of a semi-transmission type, a small transmission type, or a small reflection type.
[0210]
First, a resin 8 was applied to the surface of a light incident side substrate of a liquid crystal display element manufactured by a known method using a substrate having an appropriate thickness, and embossing was performed on the resin 8 using the matrix 6. After that, the resin 8 is cured to obtain the microlens array 32. Next, the backlight is transmitted through the lenses of the microlens array 32 so that the light is focused on the transmission portion of the pixel electrode of the TFT substrate, and the light incident side substrate is assembled to the TFT substrate. A liquid crystal display device with an array is obtained. Thereby, a liquid crystal display device with a microlens array having a uniform lens pattern can be manufactured at lower cost.
[0211]
(Third embodiment)
The third embodiment is a mode in which the present invention is applied to the production of an optical waveguide by an isotropic etching method.
[0212]
FIG. 10 is a cross-sectional view showing a third embodiment of the present invention in the order of manufacturing steps.
[0213]
As shown in FIG. 10 (A), as in the first embodiment, a non-alkali glass containing aluminum oxide or the like is used as a substrate 1 and a metal film 2 and a resist 3 are formed on the substrate 1. An etching mask is formed.
[0214]
A rectangular opening 3b following the pattern of the optical waveguide is formed in the etching mask, and the width of two opposing sides of the opening 3b is as shown in Table 1 shown in the first embodiment. A table showing the relationship between the width of the opening 3b and the width of the formed optical waveguide is created in advance, and the table is determined from the width of the formed optical waveguide based on the created table.
[0215]
Next, the substrate 1 is etched using a hydrofluoric acid-based etchant as the etchant 4. FIG. 10B is a cross-sectional view showing an initial stage of the etching.
[0216]
When the etching starts, the isotropic etching of the substrate 1 proceeds from the opening 3b, and a minute groove is formed. Aluminum fluoride or the like, which is an insoluble matter 5 with respect to the etchant, generated by the etching accumulates on the substrate surface in the fine groove, hinders the progress of the etching of the substrate 1, and eventually stops the etching, and the A wave pattern is formed (FIG. 10C).
[0219]
After removing the insoluble matter 5 together with the metal film 2 and the resist 3, a high refractive index material having a higher refractive index than that of the substrate 1 is buried in the formed groove to form an optical waveguide 13 (FIG. 10D). .
[0218]
In the present embodiment, the substrate 1 contains aluminum oxide or the like as a substance that generates the insoluble matter 5 for the etchant 4, and the insoluble matter 5 for the etchant 4 is generated by etching. Thus, a uniform optical waveguide pattern can be produced at low cost even on a large-area substrate without providing an etching stopper layer or the like. In addition, there is no variation in the amount of etching in each etching process, and it is possible to form an optical waveguide pattern having a uniform concave shape between the etching processes.
[0219]
Further, as described in the first embodiment, if the substrate 1 is oxyhalide glass, calcium fluoride or the like is contained as a substance that does not dissolve in the hydrofluoric acid-based etchant. The same actions and effects as those of the object 5 are produced.
[0220]
After removing the insoluble matter 5 together with the metal film 2 and the resist 3, a high-refractive-index material was molded on another substrate using a 2P molding method, using the produced optical waveguide-shaped depression pattern as a matrix. By forming an optical waveguide, a strip waveguide or a rib waveguide can be obtained. Also in this case, it is possible to manufacture a large matrix at a high yield and at a low cost, to reduce the error caused by the difference in thermal expansion coefficient, to eliminate strict temperature control, and to use a thermosetting resin. The following advantages can be obtained: errors in the heating step when used can be reduced; and cost reduction can be achieved because inexpensive alkali-free glass or the like can be used as a material for the matrix.
[0221]
(Fourth embodiment)
The fourth embodiment is a mode in which the present invention is applied to the production of a buried wiring by an isotropic etching method.
[0222]
FIG. 11 is a sectional view showing a fourth embodiment of the present invention in the order of manufacturing steps.
[0223]
As shown in FIG. 11A, as in the first embodiment, a non-alkali glass uniformly containing aluminum oxide or the like is used as a substrate 1 and a metal film 2 and a resist 3 are formed on the substrate 1. An etching mask is formed.
[0224]
A rectangular opening 3c following the pattern of the buried wiring is formed in the etching mask, and the width of two opposing sides of the opening 3c is as shown in Table 1 shown in the first embodiment. A table showing the relationship between the width of the opening 3c and the width of the buried wiring to be formed is created in advance, and the table is determined from the width of the buried wiring to be formed based on the created table.
[0225]
Next, the substrate 1 is etched using a hydrofluoric acid-based etchant as the etchant 4. FIG. 11B is a cross-sectional view showing a state in an initial stage of etching.
[0226]
When the etching starts, the isotropic etching of the substrate 1 proceeds from the opening 3c, and a minute groove is formed. Aluminum fluoride or the like, which is an insoluble matter 5 for the etchant, generated by etching accumulates on the surface of the substrate in the minute groove, hinders the progress of the etching of the substrate 1, and eventually stops the etching and the wiring A pattern is formed (FIG. 11C).
[0227]
After removing the insoluble matter 5 together with the metal film 2 and the resist 3, a wiring metal layer 9 is formed by a known method such as a sputtering method (FIG. 11D). Next, using a chemical or mechanical polishing method, the wiring metal layer 9 other than in the formed groove is removed to form a buried wiring 9a (FIG. 11E).
[0228]
In the present embodiment, the substrate 1 contains aluminum oxide or the like as a substance that generates the insoluble matter 5 for the etchant 4, and the insoluble matter 5 for the etchant 4 is generated by etching. It is possible to produce a uniform pattern for embedded wiring even at a low cost even on a large-area substrate. Also, there is no variation in the amount of etching in each etching process, and it is possible to form a buried wiring pattern having a uniform concave shape between the etching processes.
[0229]
Further, as described in the first embodiment, if the substrate 1 is oxyhalide glass, calcium fluoride or the like is contained as a substance that does not dissolve in the hydrofluoric acid-based etchant. The same actions and effects as those of the object 5 are produced.
[0230]
(Fifth embodiment)
The fifth embodiment is a mode in which the present invention is applied to the production of a diffraction grating by an isotropic etching method.
[0231]
FIG. 12 is a sectional view showing a fifth embodiment of the present invention in the order of manufacturing steps.
[0232]
As shown in FIG. 12A, a resist 3 is applied on a non-alkali glass substrate 1 containing aluminum oxide or the like uniformly by a known method such as spin coating and dried. The resist 3 has a resolution corresponding to the wavelength of light used in the next step of exposure and having a resolution enough to form a diffraction grating. As an example, a photoresist for excimer laser can be suitably used.
[0233]
Thereafter, the resist 3 is subjected to interference exposure using an excimer laser beam or the like, and a resist developing process is performed to form an etching mask having a diffraction grating pattern including fine openings 3d (FIG. 12B). ).
[0234]
A rectangular opening 3d following the pattern of the diffraction grating is formed in the etching mask. The width of two opposing sides of the opening 3d and the interval between the openings 3d are described in the first embodiment. A table as shown in Table 1, which shows the relationship between the width and interval of the opening 3d and the width of the concave portion of the formed diffraction grating in advance, and the width of the concave portion of the diffraction grating formed based on the prepared table To decide from.
[0235]
Next, the substrate 1 is etched using a hydrofluoric acid-based etchant as the etchant 4. FIG. 12C is a cross-sectional view showing a state in an initial stage of the etching.
[0236]
When the etching is started, the isotropic etching of the substrate 1 proceeds from the opening 3d, and a minute groove is formed. Aluminum fluoride or the like, which is an insoluble matter 5 with respect to the etchant 4, generated by the etching accumulates on the surface of the substrate 1 in the minute groove, hinders the progress of the etching of the substrate 1, and eventually stops the etching. I do.
[0237]
Thereafter, when the resist 3 is peeled off and the insoluble matter 5 is washed away, a diffraction grating 34 provided with a plurality of grooves is formed as shown in FIG.
[0238]
In the present embodiment, the substrate 1 contains aluminum oxide or the like as a substance that generates the insoluble matter 5 for the etchant 4, and the insoluble matter 5 for the etchant 4 is generated by etching. And a uniform diffraction grating pattern can be produced at low cost even with a large-area substrate. Further, there is no variation in the etching amount in each etching process, and a diffraction grating having a uniform pattern shape between the etching processes can be formed.
[0239]
The substrate 1 may be made of low alkali glass, borosilicate glass, or lead glass in addition to the alkali-free glass, as in the first embodiment. If the substrate 1 is oxyhalide glass, calcium fluoride or the like is contained as a substance that does not dissolve in the hydrofluoric acid-based etching solution, and thus calcium fluoride or the like produces the same function and effect as the insoluble matter 5.
[0240]
The diffraction grating 34 manufactured in this manner can be used as a large-area and inexpensive optical element. For example, the diffraction grating 34 can be used as a substrate of an organic electroluminescence element to improve light extraction efficiency. You can also. In this case, the advantage that a large-area diffraction grating 34 can be manufactured by an inexpensive method using an inexpensive alkali-free glass substrate can be utilized to the utmost.
[0241]
(Sixth embodiment)
The sixth embodiment is a mode in which the present invention is applied to the production of a liquid crystal alignment film by an isotropic etching method.
[0242]
FIG. 13 is a cross-sectional view showing a sixth embodiment of the present invention in the order of manufacturing steps.
[0243]
As shown in FIG. 13A, a transparent electrode 10 is formed on a substrate 1, and an alignment film 11 for determining an alignment direction of liquid crystal molecules is formed on the transparent electrode 10. The alignment film 11 is a film of an inorganic material containing aluminum oxide or the like uniformly.
[0244]
Next, as shown in FIG. 13B, an etching mask is formed using the same method as in the fifth embodiment, but the longitudinal direction of the rectangular opening 3e is aligned with the arrangement direction of the injected liquid crystal molecules. Almost match. As a material of the etching mask, a resist 3 or the like can be preferably used.
[0245]
A rectangular opening 3e following the pattern of the liquid crystal alignment film to be formed is formed as an etching mask. The width of two opposing sides of the opening 3e and the interval between the openings 3e are the same as those in the first embodiment. A table showing the relationship between the width and the interval of the opening 3e and the width of the concave portion of the liquid crystal alignment film to be formed as in Table 1 shown in the form is prepared in advance, and the liquid crystal formed based on the prepared table is prepared. It is determined from the width of the concave portion of the alignment film.
[0246]
Thereafter, the alignment film 11 is etched using a hydrofluoric acid-based etchant as the etchant 4. FIG. 13C is a cross-sectional view showing a state in an initial stage of etching.
[0247]
When the etching starts, the isotropic etching of the alignment film 11 proceeds, and a minute groove is formed. Aluminum fluoride or the like, which is an insoluble matter 5 with respect to the etchant 4, generated by the etching accumulates on the surface of the alignment film in the minute groove, hinders the progress of etching of the alignment film 11, and eventually stops the etching. I do.
[0248]
Next, when the resist 3 is peeled off and the insoluble matter 5 is washed away, a liquid crystal alignment film 11a in which a plurality of grooves and a plurality of linear protrusions are provided alternately is formed as shown in FIG.
[0249]
In the present embodiment, since the alignment film 11 contains aluminum oxide or the like as a substance that generates the insoluble matter 5 with respect to the etchant 4 and the insoluble matter 5 with respect to the etchant 4 is generated by the etching, the etching is performed in a state where the etching has progressed to some extent. A liquid crystal alignment film having a uniform uneven shape can be manufactured at low cost even when it is automatically stopped and manufactured on a large-area substrate. In addition, there is no variation in the amount of etching in each etching process, and a liquid crystal alignment film having a uniform pattern shape between the etching processes can be formed.
[0250]
In addition, instead of containing aluminum oxide or the like that forms the insoluble matter 5, at least one of the substances such as calcium fluoride described in the first embodiment is contained in the alignment film 11 as a substance that does not dissolve in the etchant 4. It may be. When the alignment film 11 contains a substance that does not dissolve in the etchant 4, this substance produces the same action and effect as the insoluble matter 5.
[0251]
Furthermore, using two substrates 1 on which the liquid crystal alignment film 11 is formed, a sealing material is printed on one of them, and then the two substrates 1 are bonded to form a panel, and liquid crystal is injected into the panel. A liquid crystal display device was used. As a result, a liquid crystal alignment film having high reliability and uniformity can be manufactured over a large area at low cost.
[0252]
In particular, by using an inorganic material as the alignment film 11, when used in combination with a partition structure for partitioning a space into which liquid crystal is injected, damage to the alignment film due to the partition formation process can be eliminated. Even when a smectic liquid crystal that is easily damaged is used, uniform alignment can be obtained.
[0253]
(Seventh embodiment)
The seventh embodiment is a mode in which the present invention is applied to the production of a wire grid type polarizing optical element.
[0254]
FIG. 14 is a sectional view showing the seventh embodiment of the present invention in the order of manufacturing steps.
[0255]
As shown in FIG. 14A, a metal film 20 is formed on a substrate 1. As the material of the metal film 20, for example, an alloy of Ti and Al can be used, and the metal film 20 is formed by using a known sputtering method or the like.
[0256]
Next, as shown in FIG. 14B, an etching mask is formed of the resist 3 by using the same method as in the fifth embodiment, but the longitudinal direction of the rectangular opening 3f is the polarization direction in which the light is transmitted. And orthogonal.
[0257]
A rectangular opening 3f following the pattern of the polarizing optical element to be formed is formed in the etching mask. The width of two opposing sides of the opening 3f and the distance between the openings 3f are the same as those in the first embodiment. As shown in Table 1 above, a table showing the relationship between the width and the interval of the opening 3f and the width of the concave portion of the polarizing optical element to be formed is created in advance, and the polarization formed based on the created table. It is determined from the width of the concave portion of the optical element.
[0258]
Thereafter, the metal film 20 is etched using the metal film etchant 40 containing hydrofluoric acid. FIG. 14C is a cross-sectional view showing a state in an initial stage of etching.
[0259]
When the etching starts, the isotropic etching of the metal film 20 proceeds, and a minute groove is formed. Aluminum fluoride, which is an insoluble matter 5 with respect to the etchant 4 generated by the etching, accumulates on the surface of the metal film in the minute groove, hinders the progress of the etching of the metal film 20, and finally stops the etching.
[0260]
Thereafter, when the resist 3 is peeled off and the insoluble matter 5 is washed away, a wire grid type polarizing optical element 20a in which a plurality of grooves and metal wires are alternately provided as shown in FIG. 14D is obtained.
[0261]
In the present embodiment, since the metal film 20 contains aluminum, which is a substance that generates the insoluble matter 5 for the etchant 4, and the insoluble matter 5 for the etchant 4 is generated by the etching, the etching is automatically performed in a state where the etching has progressed to some extent. Even if it is stopped on a large area, the wire grid type polarizing optical element having a uniform metal wire pattern can be manufactured at low cost. Further, there is no variation in the amount of etching in each etching process, and a polarizing optical element having a uniform pattern shape between the etching processes can be formed.
[0262]
Further, by using the condition that the side etching of the metal film 20 under the resist 3 stops when the etching from the opening 3f reaches the substrate 1, over-etching of the metal film 20 under the resist 3 can be prevented. it can.
[0263]
The metal film 20 may include at least one of magnesium, calcium, potassium, strontium, barium, lithium, sodium, cesium, zinc, and lead. These substances react with hydrofluoric acid to produce the insolubles 5 like the aluminum.
[0264]
(Eighth embodiment)
The eighth embodiment is a mode in which the present invention is applied to a microchemical analysis system or a microchip pattern used for LOC by an isotropic etching method.
[0265]
FIG. 15 is a top view showing a concave pattern of a microchip formed on the substrate surface.
[0266]
As shown in FIG. 15, on the surface of the substrate 1 of the microchip, a reagent tank 15 into which a chemical is injected, a reaction tank 16 in which various chemicals are mixed and reacted, and a chemical from the reagent tank 15 to the reaction tank 16. And a microchip liquid outlet 14 for moving the liquid.
[0267]
The method for manufacturing the microchip liquid outlet 14 will be described below.
[0268]
FIG. 16 is a sectional view showing an eighth embodiment of the present invention in the order of manufacturing steps. Note that the portion shown in FIG. 16 is a cross section of the broken line portion YY ′ shown in FIG.
[0269]
As shown in FIG. 16A, as in the first embodiment, a non-alkali glass containing aluminum oxide or the like is used as the substrate 1 and a liquid outlet for microchip is formed on the substrate 1. An etching mask composed of the metal film 2 and the resist 3 is formed.
[0270]
A rectangular opening 3g following the pattern of the microchip liquid outlet 14 is formed in the etching mask. The widths of two opposing sides of the opening 3g are shown in Table 1 shown in the first embodiment. A table showing the relationship between the width of the opening 3g and the width of the formed microchip liquid outlet 14 is prepared in advance, and the pattern of the microchip liquid outlet 14 formed based on the prepared table. Determined from the width of
[0271]
Next, the substrate 1 is etched using a hydrofluoric acid-based etchant as the etchant 4. FIG. 16B is a cross-sectional view showing a state in an initial stage of the etching.
[0272]
When the etching starts, the isotropic etching of the substrate 1 proceeds from the opening 3g to form a minute groove. Aluminum fluoride or the like, which is an insoluble matter 5 with respect to the etchant, generated by the etching accumulates on the substrate surface in the minute groove, hinders the progress of the etching of the substrate 1, and eventually stops the etching, An outgoing route pattern is formed (FIG. 16C).
[0273]
After removing the insoluble matter 5 together with the metal film 2 and the resist 3, the microchip liquid outlet 14 is obtained (FIG. 16D).
[0274]
According to the above-described manufacturing method, a pattern is formed in the reagent tank 15 and the reaction tank 16 by accumulating the insoluble matter 5 as in the case of the microchip liquid outlet 14.
[0275]
In the case where the pattern interval of the microchip liquid outlet path 14 is narrowed to increase the pattern integration degree, the width of two opposing sides of the opening 3g and the interval between the openings 3g are the same as in the first embodiment. A table showing the relationship between the width of the two opposite sides of the opening 3g and the interval between the openings 3g and the width of the microchip liquid outlet 14 is created, and is determined from the width of the microchip liquid outlet 14 to be formed. Good.
[0276]
Also, in the present embodiment, the pattern of the microchip liquid outlet 14 has been described as a method of manufacturing a microchip pattern. However, the present embodiment can be applied to the patterns of the reagent tank 15 and the reaction tank 16. it can. At this time, if the microchip pattern is not limited to a quadrangle but is a polygon including an octagon, the width of two opposing sides of the opening 3g is changed to the maximum width of the opening 3g, and the width of the opening 3g is changed to the maximum. A table showing the relationship between the size and the width of the formed microchip pattern may be created in advance, and the maximum width of the opening 3g may be determined from the width of the formed microchip pattern based on the created table.
[0277]
In this embodiment, the substrate 1 contains aluminum oxide or the like as a substance that generates the insoluble matter 5 with respect to the etchant 4, and the insoluble matter 5 with respect to the etchant 4 is generated by etching. It is possible to produce a uniform microchip pattern even at a low cost even on a large-area substrate. In addition, there is no variation in the amount of etching in each etching process, and a microchip pattern having a uniform concave shape between the etching processes can be formed.
[0278]
Further, as described in the first embodiment, if the substrate 1 is oxyhalide glass, calcium fluoride or the like is contained as a substance that does not dissolve in the hydrofluoric acid-based etchant. The same actions and effects as those of the object 5 are produced.
[0279]
Note that the present invention is not limited to the use of forming a fine structure in the first to eighth embodiments as described above. Even when a large structure is formed, the amount of etching is controlled. It can be used for the purpose of improving the uniformity of the formed pattern shape. This is because, even when a large structure is formed, insolubles with respect to the etchant accumulate on the surface of the object to be etched, and the progress of etching can be stopped.
[0280]
In addition to the isotropic etching, even when the etching has a certain degree of anisotropy, as described above, the etching is stopped by generating a substance insoluble in the etching solution, and the uniformity of the formed pattern shape is achieved. It can be used for the purpose of improving the performance.
[0281]
【The invention's effect】
Since the present invention is configured as described above, the following effects can be obtained.
[0282]
Regarding the fine structure obtained by using the method for forming a fine structure using the isotropic etching method of the present invention, even when the present invention is used for etching a plurality of substrates for a large substrate, not only in the substrate plane but also between the substrates. However, a fine structure with high uniformity can be manufactured. Further, since relatively inexpensive glass for a liquid crystal display element can be used, cost reduction can be achieved.
[0283]
Further, by using the present invention for the production of a matrix in the 2P molding method, not only can a large-sized matrix be produced at a high yield and at low cost, but also a substrate of the same type as the matrix can be used. Thus, an error caused by a difference in thermal expansion coefficient can be reduced, and strict temperature control becomes unnecessary. Since a large matrix can be used, the cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a first embodiment of the present invention in the order of manufacturing steps.
FIG. 2 is a perspective view schematically showing the appearance of a liquid crystal display device using the microlens array substrate 12 manufactured according to the first embodiment.
FIG. 3 is a cross-sectional view illustrating a method of manufacturing a liquid crystal display element using the microlens array substrate manufactured according to the first embodiment in the order of manufacturing steps.
FIG. 4 is a cross-sectional view illustrating a method of manufacturing a liquid crystal display element using the microlens array substrate manufactured according to the first embodiment in the order of manufacturing steps.
FIG. 5 is a cross-sectional view illustrating a method for manufacturing a liquid crystal display element using the microlens array substrate manufactured according to the first embodiment in the order of manufacturing steps.
FIG. 6 is a cross-sectional view showing another configuration example of the liquid crystal display device using the microlens array substrate manufactured according to the first embodiment.
FIG. 7 is a schematic diagram showing one configuration example of a liquid crystal projector using the liquid crystal display element shown in FIG.
8 is a perspective view schematically showing the appearance of a transflective liquid crystal display device using the liquid crystal display device shown in FIG.
FIG. 9 is a sectional view showing a second embodiment of the present invention in the order of manufacturing steps.
FIG. 10 is a cross-sectional view illustrating a third embodiment of the present invention in the order of manufacturing steps.
FIG. 11 is a cross-sectional view showing a fourth embodiment of the present invention in the order of manufacturing steps.
FIG. 12 is a cross-sectional view showing a fifth embodiment of the present invention in the order of manufacturing steps.
FIG. 13 is a cross-sectional view showing a sixth embodiment of the present invention in the order of manufacturing steps.
FIG. 14 is a cross-sectional view illustrating a seventh embodiment of the present invention in the order of manufacturing steps.
FIG. 15 is a top view showing a concave pattern of a microchip manufactured according to an eighth embodiment of the present invention.
FIG. 16 is a sectional view showing an eighth embodiment of the present invention in the order of manufacturing steps.
FIG. 17 is a cross-sectional view for explaining a manufacturing process of a microlens array using a conventional 2P molding method.
FIG. 18 is a cross-sectional view for explaining a manufacturing process of a microlens array using a conventional transfer method.
FIG. 19 is a cross-sectional view for explaining a manufacturing process of a microlens array using a conventional isotropic etching method.
[Explanation of symbols]
1, 30, 201 substrate
1a, 201a Columnar pattern
2,20,202 Metal film
3,203 resist
3a, 3b, 3c, 3d, 3e, 3f, 3g, 203a Opening
4 Etchant
5 Insoluble matter
6,114 matrix
7, 107 Release agent
8,108 resin
9 Metal layer for wiring
9a Embedded wiring
10 Transparent electrode
11 Alignment film
11a Liquid crystal alignment film
12,212 Micro lens array substrate
13 Optical waveguide
14 Liquid outlet for microchip
15 Reagent tank
16 Reaction tank
20a Polarizing optical element
32, 112, 120, 122 Micro lens array
34 diffraction grating
40 Metal film etchant
50, 250a TFT substrate
51,251 Adjustment glass plate
52, 252 liquid crystal layer
100 glass substrate
104 Wet etchant
115 Heat deformable pattern
115a hemispherical pattern
116 Mask layer
117 quartz glass substrate
130 light source
131 reflector
132 Polarization Conversion Integrator
133, 134 Dichroic mirror
135, 136, 137 Total reflection mirror
138 Liquid crystal display element for red
139 Green Liquid Crystal Display
140 blue liquid crystal display element
141 Cross dichroic prism
142 Projection lens
151, 260 Liquid crystal display element
152, 153 Polarizing plate
154 backlight unit
155 signal supply circuit
156 Power supply unit
203b Exposure position adjustment marker
212a Individual microlens array substrate
250a Individual TFT substrate
253 Protective material
254 High refractive index adhesive
255 Overlay position adjustment marker
256 pixel light shield
257 TFT substrate side superposition position adjustment marker
258 Sealant

Claims (45)

A method for forming a fine structure, wherein an etching object is used to etch the object to be etched on an object to be etched having a mask having a predetermined opening provided on a surface thereof, and a concave portion is formed on the surface of the object to be etched. hand,
A reaction between the substance contained in the body to be etched and the etching solution to generate an insoluble material,
A method for forming a fine structure, characterized in that etching is stopped by an insoluble material accumulated on an exposed surface of the object to be etched. The method for forming a fine structure according to claim 1,
The object to be etched contains at least one of aluminum oxide, magnesium oxide, calcium oxide, potassium oxide, strontium oxide, barium oxide, lithium oxide, sodium oxide, cesium oxide, zinc oxide, and lead oxide. Structure formation method. A method for forming a fine structure, wherein an etching object is used to etch the object to be etched on an object to be etched having a mask having a predetermined opening provided on a surface thereof, and a concave portion is formed on the surface of the object to be etched. hand,
Leaching the substance from the body to be etched containing a substance that does not dissolve in the etching solution,
A method for forming a fine structure, characterized in that etching is stopped by a substance accumulated on an exposed surface of the object to be etched. The method for forming a fine structure according to claim 3,
A method for forming a fine structure, characterized in that an object to be etched contains at least one of calcium fluoride, sodium fluoride, barium fluoride, aluminum fluoride, strontium fluoride, and magnesium fluoride. The method for forming a microstructure according to claim 2 or 4,
A method for forming a fine structure, wherein the etching solution contains hydrofluoric acid. The method for forming a fine structure according to any one of claims 1 to 5,
A method for forming a fine structure, wherein the fine structure is a microlens. The method for forming a fine structure according to any one of claims 1 to 6,
The opening provided in the mask is circular,
Create a table showing the relationship between the diameter of the opening and the diameter of the recess formed corresponding to the diameter of the opening,
A method for forming a fine structure, comprising forming a diameter of the opening corresponding to a desired diameter of a concave portion as a mask according to the table. The method for forming a fine structure according to any one of claims 1 to 5,
A method for forming a fine structure, wherein the fine structure is used in a microlens array in which concave portions are continuously formed. The method for forming a fine structure according to claim 8,
The opening provided in the mask is circular,
Create a table showing the relationship between the diameter and spacing of the opening, the diameter of the recess formed corresponding to the diameter and spacing of the opening,
A method of forming a fine structure, comprising forming a mask with a diameter and an interval of the opening corresponding to a desired concave diameter according to the table. The method for forming a fine structure according to claim 9,
A method for forming a fine structure, wherein a diameter of an opening is not more than 1/3 of a distance between the openings. In the method for forming a fine structure according to claim 9 or 10,
A method for forming a fine structure, wherein a diameter of an opening is at least 1/10 of an interval between the openings. The method for forming a fine structure according to claim 8,
The opening provided in the mask is square,
Create a table showing the relationship between the width of the two sides facing the opening and the interval between the openings, and the width of the recess formed corresponding to the width and the interval of the opening,
A method for forming a fine structure, comprising: forming a mask with a width and an interval of the opening corresponding to a desired recess width according to the table. The method for forming a fine structure according to claim 12,
A method for forming a microstructure, wherein the width of two opposing sides of an opening is not more than 1/3 of the interval between the openings. In the method for forming a fine structure according to claim 12 or 13,
A method for forming a fine structure, wherein a width of two opposite sides of an opening is at least 1/10 of a distance between the openings. The method for forming a fine structure according to any one of claims 8 to 14,
The object to be etched is a glass substrate,
A method for forming a fine structure, wherein a mask comprises a metal film and an organic film sequentially formed on the surface of the glass substrate. The method for forming a fine structure according to claim 15,
A method for forming a fine structure, wherein the thickness of the metal film is from 20 nm to 300 nm. In the method for forming a fine structure according to claim 15 or 16,
A method for forming a fine structure, wherein the thickness of the organic film is from 200 nm to 4000 nm. The method for forming a fine structure according to any one of claims 8 to 17,
Providing positioning means on the surface of the object to be etched,
A method for forming a fine structure, comprising forming a protective material for protecting the positioning means from an etching solution. The method for forming a microstructure according to claim 18,
A method for forming a fine structure, wherein an alignment means is manufactured in the same step as a mask having an opening. The method for forming a fine structure according to any one of claims 1 to 5,
A fine structure forming method, wherein the fine structure is an optical waveguide pattern. The method for forming a fine structure according to any one of claims 1 to 5,
A method for forming a fine structure, wherein the fine structure is a buried wiring pattern. The method for forming a fine structure according to any one of claims 1 to 6, claim 20, and claim 21,
The opening provided in the mask is square,
Create a table showing the relationship between the width of two opposite sides of the opening and the width of the recess formed corresponding to the width of the opening,
A method for forming a fine structure, comprising forming a mask with a width of the opening corresponding to a desired width of a concave portion according to the table. The method for forming a fine structure according to any one of claims 1 to 5,
A method for forming a fine structure, wherein the fine structure is a diffraction grating. The method for forming a fine structure according to any one of claims 1 to 5,
A method for forming a fine structure, wherein the fine structure is a liquid crystal alignment film. The method for forming a fine structure according to claim 1,
A method for forming a fine structure, wherein the fine structure is a polarizing optical element. The method for forming a microstructure according to claim 25,
A method for forming a microstructure, characterized in that an object to be etched contains at least one of aluminum, magnesium, calcium, potassium, strontium, barium, lithium, sodium, cesium, zinc, and lead. The method for forming a microstructure according to claim 26,
A method for forming a fine structure, wherein the etching solution contains hydrofluoric acid. The method for forming a fine structure according to any one of claims 1 to 5,
A method for forming a fine structure, wherein the fine structure is a pattern for a microchip. The method for forming a fine structure according to claim 28,
The opening provided in the mask is polygonal,
Create a table showing the relationship between the maximum width of the opening and the width of the recess formed corresponding to the maximum width of the opening,
A method for forming a fine structure, comprising: forming a mask with a maximum width of the opening corresponding to a desired recess width according to the table. The method for forming a fine structure according to any one of claims 23 to 28,
The opening provided in the mask is square,
Create a table showing the relationship between the width of the two sides facing the opening and the interval between the openings, and the width of the recess formed corresponding to the width and the interval of the opening,
A method for forming a fine structure, comprising: forming a mask with a width and an interval of the opening corresponding to a desired recess width according to the table. 20. A microlens array substrate having a recess formed by the method for forming a microstructure according to claim 8. A microlens array matrix having a concave portion formed by the method for forming a microstructure according to claim 8. 20. A microlens array substrate formed by the microstructure forming method according to claim 18 or 19,
A microlens array substrate having light shielding means. A matrix for a microlens array having a concave portion,
A microlens array mother comprising at least one of aluminum oxide, magnesium oxide, calcium oxide, potassium oxide, strontium oxide, barium oxide, lithium oxide, sodium oxide, cesium oxide, zinc oxide, and lead oxide. Type. The matrix for a microlens array according to claim 34,
A microlens array matrix having a columnar pattern around a lens. A microlens array substrate having a concave portion serving as a lens,
A microlens array substrate comprising at least one of aluminum oxide, magnesium oxide, calcium oxide, potassium oxide, strontium oxide, barium oxide, lithium oxide, sodium oxide, cesium oxide, zinc oxide, and lead oxide. The microlens array substrate according to claim 36,
A microlens array substrate having a columnar pattern around a lens. The microlens array substrate according to claim 36 or claim 37,
A microlens array substrate, wherein a material having a higher refractive index than the microlens array substrate is embedded in the concave portion. The microlens array substrate according to any one of claims 36 to 38,
A microlens array substrate having a transparent substrate on the side of the concave portion. The microlens array substrate according to any one of claims 36 to 39,
A microlens array substrate having positioning means. The microlens array substrate according to any one of claims 36 to 40,
A microlens array substrate having light shielding means. A liquid crystal display device using the microlens array substrate according to any one of claims 31 and 36 to 41. The liquid crystal display device according to claim 42,
A liquid crystal display device comprising: a microlens array substrate; and a substrate sandwiching liquid crystal between the microlens array substrate and the substrate. A liquid crystal display device using the liquid crystal display device according to claim 42 or 43. A liquid crystal projector using the liquid crystal display device according to claim 42 or 43.

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