JP4501292B2

JP4501292B2 - Coating substrate, coating material coating method, and element manufacturing method

Info

Publication number: JP4501292B2
Application number: JP2001060335A
Authority: JP
Inventors: 雅弘森川; 和三古田
Original assignee: Konica Minolta Inc
Current assignee: Konica Minolta Inc
Priority date: 2001-03-05
Filing date: 2001-03-05
Publication date: 2010-07-14
Anticipated expiration: 2021-03-05
Also published as: JP2002263553A

Description

【０００１】
【発明の属する技術分野】
本発明は、被塗布部材及び塗布材の塗布方法に関し、特に、曲面を有する基材にレジストを塗布して、均一な膜厚分布を得ることができるものに関する。
【０００２】
【従来の技術】
従来より、例えば光リソグラフ、ＥＢ（電子ビーム）リソグラフなどにおいて、基材上の平面に、レジスト等の塗布材を回転塗布するいわゆるスピンコートが知られている。
【０００３】
このスピンコートでは、平板状の基材の中央部付近にレジスト液滴を垂らすとともに、前記基材を回転させることで、当該回転による遠心力を受けて前記レジストが前記基材の表面上を塗り広がると同時に、余分なレジストを回転により振り切ることとなる。なお、基材上のレジストの膜厚分布は、レジストの物性（粘度、表面張力等）と基材を回転させる場合の回転数、周囲環境条件（温度等）により決まる。
【０００４】
【発明が解決しようとする課題】
ところで、上述のスピンコートにおいては、塗布対象の基材の一面が平面である場合には、ほぼ均一な膜厚分布を得ることができるものの、一面に曲面形状を有する基材に対して同様のスピンコートを行うと、均一な膜厚分布を得ることはできずにいた。
【０００５】
乃ち、例えば図１６に示すような曲面形状を有する基材２００に対してレジスト塗布を行うと、膜厚が不均一となる領域が生じていた。
【０００６】
本発明は、上記事情に鑑みてなされたものであり、その目的とするところは、曲面形状を有する基材において生じる膜厚の不均一を防止することのできる被塗布部材及び塗布材の塗布方法を提供することにある。
【０００７】
【課題を解決するための手段】
上記目的を達成するために、請求項１に記載の発明は、少なくとも一面に曲面部を有し、少なくとも該曲面部に対して塗布材が塗布される被塗布基材であって、当該被塗布基材自身の回転に伴い前記曲面部の頂部に滴下された前記塗布材が、ほぼ均一な膜厚を維持しつつ前記頂部より前記曲面部の周辺に向かうに従い滑らかに流下するように形成された周囲面部を設け、前記周囲面部は、前記曲面部の周囲に亘って形成された周囲平面部と、前記塗布材が滑らかに流下するように、前記周囲平面部と前記曲面部との境界領域に形成された周囲曲面部と、を含むことを特徴としている。
【０００９】
また、請求項１１に記載の発明は、塗布材が塗布される被塗布基材を回転させて、少なくとも一面に曲面部を有する前記被塗布基材に前記塗布材を塗布する塗布材の塗布方法であって、前記被塗布基材の前記曲面部の頂部に対して前記塗布材を滴下し、前記被塗布基材の回転に伴い前記頂部に滴下された前記塗布材が、ほぼ均一な膜厚を維持しつつ前記頂部より前記曲面部の周辺の周囲面部に向かうに従い滑らかに流下しながら前記塗布材が塗布される塗布材塗布工程を有し、前記周囲面部は、前記曲面部の周囲に亘って形成された周囲平面部と、前記塗布材がなだらかに流下するように、前記周囲平面部と前記曲面部との境界領域に形成された周囲曲面部と、を含み、前記塗布材塗布工程は、前記曲面部より前記周囲曲面部を介して前記周囲平面部に向けて前記塗布材が滑らかに流下しながら、前記塗布材が前記曲面部及び前記周囲曲面部並びに前記周囲平面部に塗布される工程を含むことを特徴としている。
【００１０】
また、請求項２１に記載の発明は、少なくとも一面に形成された曲面部と、前記曲面部の周囲に亘って形成された周囲平面部と、回転に伴い前記曲面部の頂部に滴下されたレジストが、ほぼ均一な膜厚を維持しつつ前記頂部より前記曲面部の周辺に向かうに従い滑らかに流下するように、前記周囲平面部と前記曲面部との境界領域に形成された周囲曲面部と、を含んでなる前記レジストが塗布される素子を、所定の加工を施すことにより製造する素子の製造方法であって、前記曲面部の頂部にて滴下された前記レジストが、当該曲面部の頂部より前記周囲曲面部を介して前記周囲平面部に向けて滑らかに流下しながら、前記レジストが前記曲面部及び前記周囲曲面部並びに前記周囲平面部に塗布される塗布工程と、前記レジストが塗布された前記周囲平面部及び前記周囲曲面部が切削される工程と、を含むことを特徴としている。
【００１１】
【発明の実施の形態】
以下、本発明の好適な実施の形態の一例について、図面を参照して具体的に説明する。
【００１２】
［第１の実施の形態］
（全体構成）
先ず、本発明の特徴的な構成である被塗布基材の説明に先立って、レジスト塗布装置の全体の概略構成について、図１を参照して説明する。図１は、本例のレジスト塗布装置の全体の概略構成を示す説明図である。
【００１３】
本例のレジスト塗布装置１（塗布材塗布装置）は、図１に示すように、塗布材例えばレジストが塗布される被塗布基材である被レジスト塗布基材１０を回転軸Ａを中心にして回転しつつ保持する保持部材であるスピンコータチャック２０と、このスピンコータチャック２０を回転、上下及び水平方向に駆動するための駆動手段３０と、この駆動手段３０において回転する場合のスピンコータチャック２０の回転数を制御する回転数制御手段３２と、塗布材であるレジスト（図１に示すＬ）を、被レジスト塗布基材１０に対して回転中心軸Ａの位置にて上方向から滴下することでレジストを塗布する塗布材塗布手段３４と、この塗布材塗布手段３４にて塗布されるレジストの量を調整制御する塗布量制御手段３６と、前記レジストの粘度を制御する粘度制御手段３７と、塗布されるレジストの膜厚がほぼ均一となるように例えば所定のレジスト量と回転数との相関関係を示した相関テーブルやさらには周囲環境条件例えば温度制御条件をも加味した条件情報などの各種制御条件情報を格納した記憶手段３８と、この記憶手段３８での各種制御条件情報に基づき、上述の各部乃ち塗布量制御手段３６並びに回転数制御手段３２などの全体の制御を司る制御手段４０と、を含んで構成されている。
【００１４】
なお、当然のことながら、このレジスト塗布装置１には、レジスト塗布時にレジスト塗布の制御条件の一つである周囲環境条件例えば温度条件を膜厚がほぼ均一となるように制御するために上述の制御手段４０とリンクする図示しない温度制御手段を備えることとなる。また、この温度制御条件としては、例えば２２〜２４℃等にて設定制御されることが好ましい。
【００１５】
被レジスト塗布基材１０は、レンズ等を形成するのに好ましい材質、例えば樹脂部材例えばポリオレフィン等にて形成され、断面略半円状に形成されて曲面を構成する曲面部１２と、この曲面部１２の周辺領域に亘って形成される周囲平面部１４と、前記曲面部１２とこの周囲平面部１４との間が滑らかな曲面となるように形成された周囲曲面部１６と、を含んで構成されている。なお、本例の周囲平面部１４と、周囲曲面部１６とで、本発明の「周囲面部」を構成している。
【００１６】
スピンコータチャック２０は、被レジスト塗布基材１０を回転保持するために、被レジスト塗布基材１０の周縁部を規定することで、回転する際の遠心力が生じる第１の方向Ｆでの移動を規制する第１の方向規制部、あるいは被レジスト塗布基材１０をチャックするためのチャック部である凹部側壁部２２と、被レジスト塗布基材１０の底面を自重により保持する凹部底壁部２４と、を有してなり、断面略凹状に形成されている。すなわち、スピンコータチャック２０は、凹部を形成している。
【００１７】
駆動手段３０は、スピンコータチャック２０を、回転中心軸Ａを中心としてθ方向に回転駆動する不図示のθ方向駆動手段と、スピンコータチャック２０を、上下のＺ軸方向に昇降駆動するＺ軸方向駆動手段（不図示）と、被レジスト塗布面を構成するＸＹ平面上をＸ軸及びＹ軸方向にそれぞれ、スピンコータチャック２０を移動させるように駆動するＸ軸方向駆動手段及びＹ軸方向駆動手段（不図示）と、被レジスト塗布基材１０を載置したスピンコータチャック２０を、所定の載置位置よりレジスト塗布位置まで搬送した後に、レジスト塗布位置でのスピンコータチャック２０のアライメント動作を行うための各方向（θ方向・Ｚ方向・Ｘ方向・Ｙ方向）の各調整機構（不図示）と、を含んで構成されている。
【００１８】
（本発明の特徴的構成）
ここで、本発明の特徴、すなわち、被レジスト塗布基材１０について図１〜図３を用いて説明する。
【００１９】
本例の被レジスト塗布基材１０は、レジストと親和性を持たせるための表面処理後、レジストがスピンコートされるものであり、上述のように曲面部１２、周囲平面部１４、周囲曲面部１６を構成している。
【００２０】
具体的には、図３に示すように、曲面例えば球面の頂部Ｘ１（被レジスト塗布基材１０の頂部）よりＸ２に至る領域を曲面部１２とし、一方、被レジスト塗布基材１０の周縁Ｘ４よりＸ３に至る球面である曲面部１２の周辺に亘って形成された周囲領域を周囲平面部１４とし、Ｘ２からＸ３の間までの周囲平面部１４と曲面部１２との境界領域を周囲曲面部１６としている。これにより、曲面部１２より周囲曲面部１６を介して周囲平面部１４に向けてレジストが滑らかに流下しながら、レジストが曲面部１２及び周囲曲面部１６並びに周囲平面部１４に塗布される。
【００２１】
曲面部１２は、図２（Ｂ）に示すように、滴下されたレジストが付着する頂部中心より、レジスト塗布後に膜厚分布がほぼ均一となることが必要とされる所定の有効径ｒ１（図２（Ｂ）においては、説明を簡単にするために片側の領域のみを図示しており、本例において「径」とは半径を意味する。しかし、球面の場合は、概念上は、半径を２倍とすれば直径となるので「径」を直径を意味するように用語を置き換えたとしても相違はない）までの有効曲面部１２ａを含む。なお、曲面部１２は、図２（Ｂ）に示すような球面に限らず、非球面である他のあらゆる曲面であってもよい。
【００２２】
周囲平面部１４は、図２（Ａ）に示すように、被レジスト塗布基材１０自身の位置を認識するための位置認識部１５を有する。
【００２３】
この位置認識部１５は、複数例えば３個形成されており、本例においては、図２（Ｂ）に示すように、断面凸状の凸部を構成している。これにより、周囲平面部１４の表面がレジストにより被覆されたとしても、凸状の位置認識部１５によって、次工程の例えば露光等の位置認識を行うことができる。
【００２４】
乃ち、より詳細には、周囲平面部１４の位置認識部１５にレジストが塗り広がらないようにしたことで、位置認識部１５の認識精度が向上し、次工程の露光装置、ＥＢ（電子ビーム）描画装置での位置決め精度を向上させることができる。
【００２５】
なお、位置認識部１５の配置位置は、有効曲面部１２ａの有効径ｒ１の少なくともほぼ３倍より離間した位置ｒ３にて形成することが好ましい。こうすると、周囲曲面部１６と干渉しないからである。
【００２６】
さらに、上述の例では、位置認識部１５を、凸状の凸部にて形成する例を挙げたが、これに限定されず、断面凹状の凹部であっても、さらには、位置認識マークにて形成する構成としてもよい。このような構成によっても上記同様の作用効果を奏することができる。
【００２７】
周囲曲面部１６は、図２（Ｂ）に示すように、曲面部１２の第１の半径Ｒ１が、周囲曲面部１６を構成する曲面の第２の半径Ｒ２のほぼ１倍〜ほぼ１０倍にて形成されるように、構成することが好ましい。さらには、第２の半径Ｒ２の接線の傾きがほぼゼロになる周囲平面部１４と周囲曲面部１６との境界領域位置Ｘ３を、有効曲面部１２ａの有効径ｒ１の少なくともほぼ２倍より離間した位置ｒ２に形成することが好ましい。こうすると、周囲曲面部１６によるレジストの滑らかな流下を促し、有効径ｒ１内の曲面部１２ａに均一な膜厚を得ることができるからである。
【００２８】
この点について詳述すると、例えば、図７に示すように、有効径（図２（Ｂ）におけるｒ１）と、接線の傾きがほぼ０になる点まででの距離（図２（Ｂ）におけるｒ２との関係は、第１の半径Ｒ１＝４ｍｍの曲面で、有効径をｒ１＝２ｍｍ得るにあたって、第２の半径Ｒ２の接線の傾きがほぼ０になる点を、基材１０の回転中心からｒ２＝４ｍｍとした場合、基材１０の回転中心からほぼ２ｍｍまで、ほぼ均一な膜厚を得ることができたことが判明した。これによって、周囲平面部１４と周囲曲面部１６との境界領域位置Ｘ３を、有効径ｒ１の少なくともほぼ２倍より離間した位置ｒ２に形成することが好ましい理由が得られる。
【００２９】
なお、本例においては、周囲曲面部１６を、球面に形成する例を示したがこれに限定されず、非球面であるあらゆる曲面にて形成してもよい。あるいは、レジスト膜の膜厚の均一化を得ることができのであれば、周囲曲面部１６を曲面と平面（テーパ）との組み合わせや平面にて形成してもよい。
【００３０】
ここで、本例においては、塗布材であるレジストを、所定のせん断応力がかかった際にのみ流動性を発揮する組成とするのが好ましい。この組成としては、例えば、粘度が少なくともほぼ１５（ｍＰａ・Ｓ）より大きい（高い）レジストを用い、スピンコートを行うことが好ましい。こうすると、回転停止時には、図１に示すように、レジストＬを滴下すると曲面部１２の頂部にレジストＬが粘性により保持され、回転を開始すると遠心力及びレジストＬの自重によって矢印Ｔ方向に沿ってレジストＬが膜厚が均一となるように周囲領域に広がるからである。
【００３１】
逆に言えば、スピンが開始する前に曲面部１２を液が垂れきることなくスピンコートを行うことができる。
【００３２】
因みに、レジストＬの異なる粘性における、レジストＬの膜厚とスピンコータチャック２０の回転数との関係は、図６に示すようになり、粘性がほぼ１５（ｍＰａ・Ｓ）以上であると回転数が１０００（ｒｐｍ）以上では、回転数の増加に関わらず膜厚はほぼ一定となる。これによって、細かい特別な回転数の制御を行わなくても膜厚の均一化が得られる。さらには、これらの粘性がほぼ１５（ｍＰａ・Ｓ）以上の各粘性における回転数と膜厚との関係を示した相関テーブルを図１の記憶手段３８などに格納することにより、粘度制御手段３７は、所望のレジストの粘度に応じた回転数の制御をも行うことができる構成とすればより好ましい。
【００３３】
さらに、周囲曲面部１６を構成したことにより、曲面部１２と周囲平面部１４との間のなだらかな曲面によってレジストＬが滑らかに流下しつつ広がることとなり、曲面部１２におけるレジスト塗布膜厚の均一化を図ることができる。
【００３４】
また、曲面部１２の周辺領域に周囲平面部１４を形成したことにより、図２（Ａ）に示すように、周囲平面部１４の外周、乃ち、曲面部の頂部Ｘ１から等高の位置からレジストＬが飛散することにより、レジスト膜に外周方向への均一な力（レジストの粘性、遠心力、並びに降下する際の重力等の組み合わせ）が加わり膜厚をコントロールできるようになった。
【００３５】
さらにまた、被レジスト塗布基材１０の材質を例えば樹脂部材にて形成することにより、被レジスト塗布基材１０を射出成型や切削成型等の加工が容易となり、供給しやすくすることができる。
【００３６】
すなわち、本発明者等が鋭意検討した結果、電子ビーム用レジスト、現像液に用いられる溶剤例えばエチルセロソルアセテート、ＰＧＭＥＡ、ＭＩＢＫ、酢酸エチル、酢酸イソアミル等に対して、被レジスト塗布基材１０を、樹脂例えばボリオレフィン等にて形成したときに、溶剤による変化が少ないことが判明した。なお、ＰＭＭＡやポリカーボネートなどは適さないことも判明した。
【００３７】
さらに、被レジスト塗布基材１０を、第１導電型の不純物部材例えば、ｎ型シリコン等にて形成することが好ましい。こうすると、レジスト塗布後の光学的な膜厚評価を適用しやすいからである。
【００３８】
この点について詳述すると、図８に示すように、ｎ型シリコンを用いた場合に、有効径（図２（Ｂ）におけるｒ１）と、接線の傾きがほぼ０になる点まででの距離（図２（Ｂ）におけるｒ２との関係は、第１の半径Ｒ１＝４ｍｍの曲面で、有効径をｒ１＝２ｍｍ得るにあたって、第２の半径Ｒ２の接線の傾きがほぼ０になる点を、基材１０の回転中心からｒ２＝４ｍｍとした場合、スピンコート後、２００℃、２０（ｍｉｎ）でベーキングしたところ、基材１０の回転中心からほぼ４ｍｍまで、ほぼ均一な膜厚を得ることができたことが判明した。
【００３９】
さらに、ｎ型シリコンの場合には、レジストのガラス転移温度以上に温度を上げることができ、レジストが溶け、表面張力でレベリングさせて、均一な膜厚を得られるという作用効果がある。また、レジスト層とシリコン層の屈折率界面がはっきりし、レジスト塗布後の光学的な膜厚評価を適用しやすい。なお、ポリオレフィンは、ガラス転移点Ｔｇが１３２℃で、電子ビーム用レジストの主成分ＰＭＭＡの場合のＴｇ＝１０５℃に対して余裕がなく、基材１０が熱変形することも判明した。このようにｎ型シリコンでは、高熱に耐えうるという作用効果がある。
【００４０】
さらに、位置認識部１５の形状を凹部とした場合には、図９に示すように、レジストが塗れ広がることを防止するための凹部の設置位置が、有効径ｒ１の２倍程度の位置の場合には、エッジ部の膜厚の乱れが、曲面部１２に伝わることが判明した。一方、図１０に示すように、凹部の設置位置を、有効径ｒ１のほぼ３倍以上の位置とした場合には、このような膜厚の乱れが曲面部１２に伝わらないことが判明した。従って、位置認識部１５として凹部を形成した場合には、有効曲面部１２ａの有効径ｒ１の少なくともほぼ３倍より離間した位置ｒ３にて形成することが好ましいことがわかる。
【００４１】
また、被レジスト塗布基材１０の回転中心とスピンコータチャック２０の回転中心が一致しない場合には、フラッターがおき、均一な膜厚分布を得られない。これに対し本例では、被レジスト塗布基材１０の回転中心と、スピンコータチャック２０の回転中心を、公差が例えばほぼ１ｍｍ以内となるように一致させてスピンコートした場合には、均一な膜厚分布を得ることができる。
【００４２】
さらには、被レジスト塗布基材１０の回転中心と、被レジスト塗布基材１０の外形中心との公差を、例えばほぼ０．５ｍｍ以内にした被レジスト塗布基材１０において、スピンコータチャック２０の回転中心と、被レジスト塗布基材１０とスピンコータチャック２０との機械的取り合い部との公差を、例えばほぼ０．５ｍｍ以内にした場合に、被レジスト塗布基材１０の回転中心とスピンコータチャック２０の回転中心とを一致させてスピンコートできるようにすると、均一な膜厚分布を得ることができる。
【００４３】
（動作について）
次に、上述のような構成を有する被レジスト塗布基材にレジストを塗布する場合の塗布工程を、被レジスト塗布基材の作用とともに図１〜図５を参照しつつ説明する。
【００４４】
不図示の搬送手段によって搬送された被レジスト塗布基材１０を、スピンコータチャック２０上に載置する。この際に、スピンコータチャック２０には、凹部が形成されているので、被レジスト塗布基材１０が当該凹部内に挿入されることで一義的に保持固定される。そして、所定のレジスト滴下位置にて駆動手段３０によりスピンコータチャック２０のアライメント動作が行われる。
【００４５】
そうすると、先ず、図１に示すように、塗布材塗布手段３４にて所定量のレジストＬを滴下しつつ、スピンコータチャック２０を駆動手段３０により、θ方向に回転することとなる。
【００４６】
この際に、膜厚が均一となるような、レジスト塗布量、スピンコータチャック２０の回転数、環境条件などの各種制御条件は、塗布量制御手段３６及び回転数制御手段３２並びに制御手段４０により制御される。
【００４７】
次に、レジストが滴下されつつ、所定の回転数にて回転されると、レジストＬは、図１に示す矢印Ｔに示すように、曲面部１２から周囲曲面部１６を経由して周囲平面部１４にまで広がることとなる。
【００４８】
この際に、図３に示すように、Ｘ１からＸ２までの曲面部１２にて広がる際には、曲面部１２の曲面に沿ってレジスト（図２に示すＬ）が広がり、次に周囲曲面部１６に至ると、前記曲面部１２にて広がるレジストの速度に対して、ほぼ同様かより早い速度となって広がることとなる。これにより、曲面部１２と周囲平面部１４とが不連続な面である場合に周囲平面部１４にレジストがぶつかる際に生じる衝撃に起因した減速により、膜厚が不均一となる場合に比して、周囲曲面部１６の連続面によって滑らかにレジストが広がる。
【００４９】
さらにこの場合に、曲面部１２及び周囲平面部１４において膜厚が均一となるが、この周囲曲面部１６においては、その境界領域において不均一となる領域が生じることが考えられる。
【００５０】
そのため、レジスト塗布後においては、周囲平面部１４を、図４に示すように、周囲曲面部１６を図５に示すように、各々切削加工することによって、曲面部１２のみのレジストを塗布した被レジスト塗布基材１０を構成することができる。
【００５１】
以上のように本実施の形態によれば、スピンコート時に生じる遠心力が、曲面部上のレジストに均一に伝わり、レジストが周辺に塗り広がってゆく際の障害がなくなり、曲面部上に均一な膜厚分布が得られる。また、基材からレジスト液滴が離れる際の応力による膜厚の不均一部は、周囲曲面部にのみ生じる。
【００５２】
また、被レジスト塗布基材の周囲平面部の位置認識部として凹部または凸部を形成することによって、位置認識部にレジストが塗り広がらないため、次工程の露光装置での位置認識部の認識精度が向上する。
【００５３】
さらに、曲面を有する被レジスト塗布基材の回転中心と、スピンコータチャックの回転中心とが一致したので、スピンコート時に生じる遠心力が、曲面部上のレジストに均一に伝わり、曲面部上に均一な膜厚分布を得ることができる。
【００５４】
［第２の実施の形態］
次に、本発明にかかる第２の実施の形態について、図１１に基づいて説明する。なお、以下には、前記第１の実施の形態の実質的に同様の構成に関しては説明を省略し、異なる部分についてのみ述べる。図１１は、本例の被レジスト塗布基材の構成を示す説明図である。
【００５５】
上述の第１の実施の形態では、被レジスト塗布基材の曲面部の突出高さを、曲面部が半球となる形状になるように形成したが、本例においては、その突出高さを低く形成することによって、被レジスト塗布基材の使用用途に応じて異なる形状とするものである。
【００５６】
具体的には、本例の被レジスト塗布基材６０は、図１１に示すように、曲面部６２と周囲曲面部６４とを形成し、頂部Ｘ１からＸ５までの曲面部６２とし、Ｘ５からＸ６までの周囲曲面部６４としている。なお、第１の実施の形態のように、本例においては、周囲平面部を構成することを省略している。
【００５７】
このような構成においても、レジスト塗布後においては、周囲曲面部６４上では膜厚不均一領域が生じるものの、Ｘ１を中心とした膜厚の均一性が必要とされる有効曲面部の有効径ｒ１２を含む曲面部６２では、膜厚の均一性が図られるので、最終加工工程において、周囲曲面部６４を切削することにより、Ｘ１を中心とした膜厚の均一性が必要とされる有効曲面部の有効径ｒ１２を確保することができる。
【００５８】
このために、例えば曲面部６２の領域を、有効径ｒ１２より大きい範囲であれば、図１１のＸ７までの径ｒ１３の領域にまで縮小して形成することもできる。
【００５９】
以上のように本実施の形態によれば、上述の第１の実施の形態と同様の作用効果を奏しながらも、曲面部の突出高さもしくは楕円における短径の長さを変更することによって、被レジスト塗布基材を用途に応じた様々な形状とすることができる。
【００６０】
［第３の実施の形態］
次に、本発明にかかる第３の実施の形態について、図１２に基づいて説明する。図１２は、本例の被レジスト塗布基材を示す説明図である。
【００６１】
上述の第１の実施の形態では、被レジスト塗布基材の曲面部の形状を半球形状としたが、本例では、曲面部の曲率半径を変える構成としている。
【００６２】
具体的には、本例の被レジスト塗布基材７０の曲面部７２は、図１２に示すように、球面Ｒ１よりやや凸状の形状を構成している。このような構成であっても、第１の実施の形態同様、周囲平面部７４及び周囲曲面部７６を形成していることから、スピンコート後には、曲面部７２においては、レジストの膜厚の均一化を図ることができる。
【００６３】
［第４の実施の形態］
次に、本発明にかかる第４の実施の形態について、図１３に基づいて説明する。図１３は、本例の被レジスト塗布基材を示す説明図である。
【００６４】
上述の第１の実施の形態では、被レジスト塗布基材の曲面部の構成を全てが曲面とする構成としたが、本例では、部分的に平面部と曲面部とを組み合わせた構成としている。
【００６５】
なお、この場合において、複数の各曲面部での各曲面の曲率半径は、各々異なるように形成してもよい。
【００６６】
具体的には、本例の被レジスト塗布基材８０は、図１３に示すように、曲面部８２、周囲曲面部８６、周囲平面部８４を有する。
【００６７】
曲面部８２は、平面部８２ａ、第１曲面部８２ｂ、第２平面部８２ｃを含んで構成される。このような構成であっても、上記第１の実施の形態とほぼ同様の作用効果を得ることができる。
【００６８】
なお、平面部８２ａ、第２の平面部８２ｃを異なる曲率半径の曲面部として構成してももちろん構わない。
【００６９】
［第５の実施の形態］
次に、本発明にかかる第５の実施の形態について、図１４（Ａ）〜（Ｃ）に基づいて説明する。図１４（Ａ）〜（Ｃ）は、本例の被レジスト塗布基材を示す説明図である。
【００７０】
上述の第１の実施の形態では、被レジスト塗布基材の周囲平面部の形状を（紙面の上からみて）ほぼ円形に形成したが、本例では、被レジスト塗布基材の周囲平面部の形状並びにスピンコータチャックの形状を、例えば図１４（Ｂ）や図１４（Ｃ）に示すような形状としている。
【００７１】
具体的には、本例の被レジスト塗布基材１００は、曲面部１０２と周囲平面部１１０並びに周囲曲面部１０４を有し、周囲平面部１１０は、図１４（Ｂ）に示すように、略八角形状に形成される。また、被レジスト塗布基材１００の形状に合わせてスピンコータチャックの形状をも略八角形状とする。これにより、スピンコート時においては、レジストＬの飛散分布を所定の方向に規定することができる。
【００７２】
同様にして、図１４（Ｃ）に示す被レジスト塗布基材１２０は、曲面部１２２と周囲平面部１２６並びに周囲曲面部１２４を有し、周囲平面部１２６は、図１４（Ｃ）に示すように、略方形状に形成される。また、被レジスト塗布基材１２０の形状に合わせてスピンコータチャックの形状をも略方形状とする。これにより、スピンコート時においては、レジストＬの飛散分布を所定の方向に規定することができる。特に、角数が少ないことにより、より集中的に飛散させる場合の集中量が増す。
【００７３】
なお、本発明にかかる装置と方法は、そのいくつかの特定の実施の形態に従って説明してきたが、当業者は本発明の主旨および範囲から逸脱することなく本発明の本文に記述した実施の形態に対して種々の変形が可能である。例えば、上述の各実施の形態では、周囲平面部を平面として形成したが、周囲外方に向かうに従い下方に傾斜するテーパに形成してもよいし、曲面部の膜厚均一化に支障をきたすことがない程度にやや曲がった曲面として形成しても、部分的に曲面や角部を有した構成であってもよい。
【００７４】
さらに、半径がＲ１、Ｒ２である各曲面の曲率半径は、上述の条件を満たせば、任意に設定できる。
【００７５】
また、位置認識部は、ある一点では凸部、他の一点では凹部を構成してもよく、さらには、各凹凸部は、異なる径の同心円上に離散して形成されても、一の同心円上において各凹凸が異なる間隔で形成されても、各凹凸が連続する溝として形成してもよい。
【００７６】
さらにまた、上述の実施の形態では、位置認識部として、凹凸又は位置認識マークを形成すする構成としたが、例えば図１５（Ａ）（Ｂ）に示すような被レジスト塗布基材１３０のように、凹部又は凸部と、位置認識マークとを各々構成してもよい。具体的には、被レジスト塗布基材１３０は、有効曲面部１３２ａを含む曲面部１３２、周囲平面部１３４，周囲曲面部１３６、周囲平面部１３４上に設けられたレジスト流出方向制御部材である凸部又は凹部１３５と、この凸部又は凹部１３５の外側であって周囲平面部１３４上に設けされた位置認識マーク１３６と、を含んで構成されている。これにより、凸部又は凹部１３５により、矢印Jのように、レジストが塗れ広がる方向を制御することができ、その外方に位置認識マーク１３６を形成することによって、この位置認識マーク１３６の周囲にレジストが塗り広がることはない。これにより、後工程での位置認識がより容易となる。なお、この位置認識マークは、周囲平面部と同一平面に構成することが好ましい。
【００７７】
さらに、上述の各実施の形態同士、あるいは各変形例との組み合わせによる例をも含むことは言うまでもない。
【００７８】
【発明の効果】
以上説明したように本発明によれば、被塗布基材に塗布材を回転塗布する時に生じる遠心力が、曲面部上の塗布材に均一に伝わり、塗布材が曲面部の周辺及び周囲面部に塗り広がってゆく際の障害がなくなり、曲面部上に均一な膜厚分布が得られる。また、被塗布基材から塗布材の液滴が離れる際の応力による膜厚の不均一部は、周囲曲面部にのみ生じる。この周囲曲面部は、膜厚の均一性に必要とされる有効曲面部の領域外であるので、後工程で切削等により処分され問題ない。
【００７９】
また、被塗布基材の周囲平面部の位置認識部として凹部または凸部を形成することによって、位置認識部にレジストが塗り広がらないため、次工程の露光装置での位置認識部の認識精度が向上する。
【００８０】
さらに、被塗布基材の回転中心と、保持部材の回転中心とを一致させる構成としているので、回転塗布時に生じる遠心力が、曲面部上の塗布材に均一に伝わり、曲面部上に均一な膜厚分布を得ることができる。
【図面の簡単な説明】
【図１】本発明のレジスト塗布装置の全体の概略を示す説明図である。
【図２】同図（Ａ）は、図１のレジスト塗布装置にて処理される被レジスト塗布基材を示す平面図であり、同図（Ｂ）は、当該被レジスト塗布基材の部分的な断面を示した概略説明図である。
【図３】図１のレジスト塗布装置にて処理される被レジスト塗布基材の加工工程の一例を示す説明図である。
【図４】図１のレジスト塗布装置にて処理される被レジスト塗布基材の加工工程の一例を示す説明図である。
【図５】図１のレジスト塗布装置にて処理される被レジスト塗布基材の加工工程の一例を示す説明図である。
【図６】レジストの粘性を変化させた場合のスピンコータチャックの回転数とレジストの膜厚との関係を示した特性図である。
【図７】有効曲面部の有効径と、周囲平面部と周囲曲面部との境界領域位置との位置関係において、基材の回転中心からの距離と膜厚との関係を示す説明図である。
【図８】被レジスト塗布基材にｎ型シリコンを用いた場合における被レジスト塗布基材の回転中心からの距離と膜厚との関係を示す説明図である。
【図９】位置認識部の配置位置を、有効径のほぼ２倍とした場合における、被レジスト塗布基材の回転中心からの距離と膜厚との関係を示す説明図である。
【図１０】位置認識部の配置位置を、有効径のほぼ３倍とした場合における、被レジスト塗布基材の回転中心からの距離と膜厚との関係を示す説明図である。
【図１１】本発明のレジスト塗布装置にて処理される被レジスト塗布基材の他の実施の形態の一例を示す説明図である。
【図１２】本発明のレジスト塗布装置にて処理される被レジスト塗布基材の他の実施の形態の一例を示す説明図である。
【図１３】本発明のレジスト塗布装置にて処理される被レジスト塗布基材の他の実施の形態の一例を示す説明図である。
【図１４】同図（Ａ）〜（Ｃ）は、本発明のレジスト塗布装置にて処理される被レジスト塗布基材並びにスピンコータチャックの他の実施の形態の一例を示す説明図である。
【図１５】同図（Ａ）（Ｂ）は、本発明のレジスト塗布装置にて処理される被レジスト塗布基材の他の実施の形態の一例を示す説明図である。
【図１６】従来のレジスト塗布装置における処理を示す説明図である。
【符号の説明】
１レジスト塗布装置１０被レジスト塗布基材（被塗布基材）
１２曲面部
１４周囲平面部
１６周囲曲面部
２０スピンコータチャック
３０駆動手段
３４塗布材塗布手段
３７粘度制御手段
４０制御手段[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method of applying the coating member及beauty coating cloth, in particular, a resist on a substrate having a curved surface by applying, to which it is possible to obtain a uniform film thickness distribution.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, so-called spin coating in which a coating material such as a resist is spin-coated on a plane on a base material is known in, for example, an optical lithography, an EB (electron beam) lithography, and the like.
[0003]
In this spin coating, a resist droplet is dropped near the center of a flat substrate, and the substrate is rotated, so that the resist is coated on the surface of the substrate by receiving centrifugal force due to the rotation. At the same time as it spreads, the extra resist is spun off by rotation. The resist film thickness distribution on the substrate is determined by the physical properties (viscosity, surface tension, etc.) of the resist, the number of rotations when the substrate is rotated, and the ambient environment conditions (temperature, etc.).
[0004]
[Problems to be solved by the invention]
By the way, in the above-mentioned spin coat, when one surface of the substrate to be coated is a flat surface, a substantially uniform film thickness distribution can be obtained, but the same applies to a substrate having a curved surface on one surface. When spin coating was performed, a uniform film thickness distribution could not be obtained.
[0005]
In other words, for example, when resist coating is performed on a substrate 200 having a curved surface shape as shown in FIG.
[0006]
The present invention has been made in view of the above circumstances, it is an object of the coated member及beauty coating fabric material capable of preventing the film uneven in thickness occurring in the substrate having a curved surface It is to provide a coating method.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 is a substrate to be coated having a curved surface portion on at least one surface, and an application material is coated on at least the curved surface portion. The coating material dropped onto the top of the curved surface portion with the rotation of the base material itself was formed so as to smoothly flow down from the top portion toward the periphery of the curved surface portion while maintaining a substantially uniform film thickness. A peripheral surface portion is provided , and the peripheral surface portion is formed in a boundary region between the peripheral flat surface portion and the curved surface portion so that the peripheral flat surface portion formed around the curved surface portion and the coating material smoothly flow down. And a surrounding curved surface portion formed .
[0009]
The invention of claim 1 1, by rotating the base material to be coated where the coating material is applied, the coating material for applying the coating material said to be coated substrate having a curved surface portion on at least one surface coating In the method, the coating material is dropped on the top of the curved surface portion of the substrate to be coated, and the coating material dropped on the top as the coating substrate rotates is a substantially uniform film. thickness have a smoothly flow down while the coating material coating step of the coating material is applied toward the periphery surface of the periphery of the curved portion from the top while maintaining the peripheral surface portion, the periphery of the curved portion The coating material applying step, and a peripheral curved surface portion formed in a boundary region between the peripheral flat surface portion and the curved surface portion so that the coating material flows down gently. Through the peripheral curved surface portion from the curved surface portion. The coating material is applied to the curved surface portion, the peripheral curved surface portion, and the peripheral flat surface portion while the coating material smoothly flows toward the surrounding flat surface portion .
[0010]
The invention according to claim 2 1, and a curved portion formed on at least one surface, and a peripheral flat portion formed around the circumference of the curved portion, which is dropped on top of the curved portion with the rotation A peripheral curved surface portion formed in a boundary region between the peripheral flat surface portion and the curved surface portion so that the resist flows smoothly from the top toward the periphery of the curved surface portion while maintaining a substantially uniform film thickness; , A device for manufacturing an element coated with the resist by performing predetermined processing, wherein the resist dripped at the top of the curved portion is the top of the curved portion. More preferably, the resist is applied to the curved surface portion, the peripheral curved surface portion, and the peripheral plane portion while flowing smoothly toward the peripheral flat surface portion through the peripheral curved surface portion, and the resist is applied. The And the step of cutting the peripheral plane portion and the peripheral curved surface portion.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an example of a preferred embodiment of the present invention will be specifically described with reference to the drawings.
[0012]
[First Embodiment]
(overall structure)
First, prior to the description of the substrate to be coated, which is a characteristic configuration of the present invention, an overall schematic configuration of the resist coating apparatus will be described with reference to FIG. FIG. 1 is an explanatory diagram showing the overall schematic configuration of the resist coating apparatus of this example.
[0013]
As shown in FIG. 1, the resist coating apparatus 1 (coating material coating apparatus) of this example has a coating substrate 10 to be coated on which a coating material, for example, a resist is coated, with a rotation axis A as the center. A spin coater chuck 20 that is a holding member that rotates and rotates, a drive unit 30 for driving the spin coater chuck 20 in a rotating, vertical and horizontal direction, and a rotation speed of the spin coater chuck 20 when the drive unit 30 rotates. The rotational speed control means 32 for controlling the resist and the resist (L shown in FIG. 1), which is a coating material, are dropped from above at the position of the rotation center axis A with respect to the resist coating base material 10. Application material application means 34 for application, application amount control means 36 for adjusting and controlling the amount of resist applied by the application material application means 34, and viscosity control of the resist The viscosity control means 37 and the correlation table showing the correlation between the predetermined resist amount and the number of rotations, for example, and the ambient environment conditions such as the temperature control conditions are set so that the film thickness of the resist to be applied is substantially uniform. Based on the various control condition information stored in the storage means 38 and various control condition information such as the condition information taken into account, the entire application amount control means 36 and the rotation speed control means 32 described above are included. And control means 40 for controlling the control.
[0014]
As a matter of course, the resist coating apparatus 1 includes the above-described environmental control conditions, for example, temperature conditions, which are one of the resist coating control conditions at the time of resist coating, in order to control the film thickness to be substantially uniform. A temperature control means (not shown) linked to the control means 40 is provided. In addition, the temperature control condition is preferably set and controlled at, for example, 22 to 24 ° C.
[0015]
The resist-coated substrate 10 is formed of a material preferable for forming a lens or the like, for example, a resin member such as polyolefin, and has a curved surface portion 12 formed in a substantially semicircular cross section to form a curved surface, and the curved surface portion. A peripheral plane portion 14 formed over 12 peripheral regions, and a peripheral curved surface portion 16 formed so as to form a smooth curved surface between the curved surface portion 12 and the peripheral plane portion 14. Has been. The peripheral plane portion 14 and the peripheral curved surface portion 16 of this example constitute the “peripheral surface portion” of the present invention.
[0016]
The spin coater chuck 20 defines the peripheral portion of the resist coating substrate 10 to rotate and hold the resist coating substrate 10, thereby moving in the first direction F in which centrifugal force is generated when rotating. The first direction restricting portion to be controlled, or the concave portion side wall portion 22 which is a chuck portion for chucking the resist coating substrate 10, and the concave bottom wall portion 24 which holds the bottom surface of the resist coating substrate 10 by its own weight. And has a substantially concave cross section. That is, the spin coater chuck 20 forms a recess.
[0017]
The drive means 30 includes a θ direction drive means (not shown) that drives the spin coater chuck 20 to rotate in the θ direction around the rotation center axis A, and a Z axis direction drive that drives the spin coater chuck 20 to move up and down in the vertical Z axis direction. Means (not shown), an X-axis direction drive means and a Y-axis direction drive means (not shown) for driving the spin coater chuck 20 to move in the X-axis and Y-axis directions on the XY plane constituting the resist coating surface, respectively. And each direction for performing the alignment operation of the spin coater chuck 20 at the resist coating position after the spin coater chuck 20 on which the resist coating substrate 10 is mounted is transported from a predetermined mounting position to the resist coating position. And (θ direction, Z direction, X direction, Y direction) each adjustment mechanism (not shown).
[0018]
(Characteristic configuration of the present invention)
Here, the characteristics of the present invention, that is, the resist-coated substrate 10 will be described with reference to FIGS.
[0019]
The resist-coated substrate 10 of this example is one in which a resist is spin-coated after a surface treatment for giving affinity to the resist. As described above, the curved surface portion 12, the surrounding flat surface portion 14, and the surrounding curved surface portion. 16 is constituted.
[0020]
Specifically, as shown in FIG. 3, a curved surface, for example, a region from the top X1 of the spherical surface (the top of the resist-coated substrate 10) to X2 is defined as the curved surface 12, while the peripheral edge X4 of the resist-coated substrate 10 A peripheral region formed over the periphery of the curved surface portion 12 that is a spherical surface reaching X3 is a peripheral plane portion 14, and a boundary region between the peripheral plane portion 14 and the curved surface portion 12 between X2 and X3 is a peripheral curved surface portion. 16 is set. Thus, the resist is applied to the curved surface portion 12, the peripheral curved surface portion 16, and the peripheral flat surface portion 14 while the resist flows smoothly from the curved surface portion 12 through the peripheral curved surface portion 16 toward the peripheral flat surface portion 14.
[0021]
As shown in FIG. 2B, the curved surface portion 12 has a predetermined effective diameter r1 (see FIG. 2) that requires a substantially uniform film thickness distribution after resist coating from the center of the top where the dropped resist adheres. In FIG. 2 (B), only one region is shown for the sake of simplicity, and “diameter” means a radius in this example, but in the case of a spherical surface, the radius is conceptually defined. If the diameter is doubled, the effective curved surface portion 12a is included up to the diameter (there is no difference even if the term is replaced with “diameter” to mean the diameter). The curved surface portion 12 is not limited to a spherical surface as shown in FIG. 2B, but may be any other curved surface that is an aspherical surface.
[0022]
As shown in FIG. 2A, the peripheral plane portion 14 has a position recognition unit 15 for recognizing the position of the resist coating substrate 10 itself.
[0023]
A plurality of, for example, three position recognition portions 15 are formed, and in this example, as shown in FIG. 2B, a convex portion having a convex cross section is formed. Thereby, even if the surface of the surrounding plane part 14 is coat | covered with the resist, position recognition, such as exposure of the following process, can be performed by the convex position recognition part 15. FIG.
[0024]
More specifically, since the resist is not spread on the position recognition unit 15 of the peripheral plane part 14, the recognition accuracy of the position recognition unit 15 is improved, and an exposure apparatus, EB (electron beam) for the next process is improved. Positioning accuracy in the drawing apparatus can be improved.
[0025]
In addition, it is preferable that the arrangement position of the position recognition unit 15 is formed at a position r3 that is at least approximately three times the effective diameter r1 of the effective curved surface part 12a. This is because it does not interfere with the surrounding curved surface portion 16.
[0026]
Furthermore, although the example which forms the position recognition part 15 in a convex-shaped convex part was given in the above-mentioned example, it is not limited to this, Even if it is a concave part with a cross-sectional concave shape, It is good also as a structure formed by. Even with such a configuration, the same effects as described above can be achieved.
[0027]
As shown in FIG. 2B, the surrounding curved surface portion 16 has the first radius R1 of the curved surface portion 12 approximately 1 to 10 times the second radius R2 of the curved surface constituting the surrounding curved surface portion 16. It is preferable to constitute so as to be formed. Furthermore, the boundary region position X3 between the peripheral flat surface portion 14 and the peripheral curved surface portion 16 where the inclination of the tangent line of the second radius R2 is substantially zero is separated from at least approximately twice the effective diameter r1 of the effective curved surface portion 12a. It is preferable to form at position r2. This is because smooth flow of the resist through the peripheral curved surface portion 16 is promoted, and a uniform film thickness can be obtained on the curved surface portion 12a within the effective diameter r1.
[0028]
This point will be described in detail. For example, as shown in FIG. 7, the effective diameter (r1 in FIG. 2B) and the distance (r2 in FIG. Is a curved surface having a first radius R1 = 4 mm, and the point where the inclination of the tangent line of the second radius R2 becomes almost zero in obtaining the effective diameter r1 = 2 mm from the rotation center of the substrate 10 is r2 = 4 mm, it was found that a substantially uniform film thickness could be obtained from the rotation center of the substrate 10 to approximately 2 mm, whereby the boundary region position between the peripheral flat surface portion 14 and the peripheral curved surface portion 16 was obtained. The reason why it is preferable to form X3 at a position r2 separated from at least approximately twice the effective diameter r1 is obtained.
[0029]
In this example, the peripheral curved surface portion 16 is formed as a spherical surface. However, the present invention is not limited to this, and the peripheral curved surface portion 16 may be formed as any curved surface that is an aspherical surface. Alternatively, if it is possible to obtain a uniform film thickness of the resist film, the peripheral curved surface portion 16 may be formed of a combination of a curved surface and a flat surface (taper) or a flat surface.
[0030]
Here, in this example, it is preferable that the resist as the coating material has a composition that exhibits fluidity only when a predetermined shear stress is applied. As this composition, for example, it is preferable to perform spin coating using a resist having a viscosity of at least about 15 (mPa · S). Thus, when the rotation is stopped, as shown in FIG. 1, when the resist L is dropped, the resist L is held on the top of the curved surface portion 12 by viscosity. When the rotation is started, the centrifugal force and the weight of the resist L cause the resist L to follow the direction of the arrow T. This is because the resist L spreads in the surrounding area so that the film thickness becomes uniform.
[0031]
In other words, the spin coating can be performed without dripping the liquid on the curved surface portion 12 before the spin starts.
[0032]
Incidentally, the relationship between the film thickness of the resist L and the rotational speed of the spin coater chuck 20 at different viscosities of the resist L is as shown in FIG. 6, and the rotational speed is about 15 (mPa · S) or more. Above 1000 (rpm), the film thickness becomes almost constant regardless of the increase in the number of rotations. As a result, the film thickness can be made uniform without fine control of the special rotation speed. Furthermore, the viscosity control means 37 is stored by storing a correlation table showing the relationship between the rotational speed and the film thickness at each viscosity of about 15 (mPa · S) or more in the storage means 38 of FIG. Is more preferable if the rotation speed can be controlled in accordance with the desired resist viscosity.
[0033]
Further, since the peripheral curved surface portion 16 is configured, the resist L smoothly flows and spreads by the gentle curved surface between the curved surface portion 12 and the peripheral flat surface portion 14, and the resist coating film thickness on the curved surface portion 12 is uniform. Can be achieved.
[0034]
Further, since the peripheral plane portion 14 is formed in the peripheral region of the curved surface portion 12, as shown in FIG. 2A, the outer periphery of the peripheral plane portion 14, that is, from the top of the curved surface portion X1 is located at the same height. By scattering L, a uniform force in the outer peripheral direction (combination of resist viscosity, centrifugal force, gravity when descending, etc.) is applied to the resist film, and the film thickness can be controlled.
[0035]
Furthermore, by forming the material of the resist-coated substrate 10 with, for example, a resin member, the resist-coated substrate 10 can be easily processed such as injection molding and cutting molding, and can be supplied easily.
[0036]
That is, as a result of intensive studies by the present inventors, the resist-coated substrate 10 was applied to a resist for an electron beam and a solvent used for a developer, such as ethyl cellosol acetate, PGMEA, MIBK, ethyl acetate, and isoamyl acetate. It has been found that there is little change due to the solvent when formed with a resin such as polyolefin. It has also been found that PMMA and polycarbonate are not suitable.
[0037]
Furthermore, it is preferable to form the resist-coated substrate 10 with a first conductivity type impurity member such as n-type silicon. This is because it is easy to apply optical film thickness evaluation after resist coating.
[0038]
This point will be described in detail. As shown in FIG. 8, when n-type silicon is used, the effective diameter (r1 in FIG. 2B) and the distance to the point where the slope of the tangential line becomes almost zero ( The relationship with r2 in FIG. 2B is based on the point that the slope of the tangent of the second radius R2 is almost zero when the effective radius is r1 = 2 mm with a curved surface having the first radius R1 = 4 mm. When r2 = 4 mm from the rotation center of the material 10, baking is performed at 200 ° C. and 20 (min) after spin coating, and a substantially uniform film thickness can be obtained from the rotation center of the substrate 10 to approximately 4 mm. Turned out to be.
[0039]
Further, in the case of n-type silicon, the temperature can be raised above the glass transition temperature of the resist, and there is an effect that the resist is melted and leveled by surface tension to obtain a uniform film thickness. In addition, the refractive index interface between the resist layer and the silicon layer is clear, and it is easy to apply an optical film thickness evaluation after resist coating. Polyolefin has a glass transition point Tg of 132 ° C. and has no room for Tg = 105 ° C. in the case of the main component PMMA of an electron beam resist, and it has also been found that the substrate 10 is thermally deformed. Thus, n-type silicon has the effect of being able to withstand high heat.
[0040]
Furthermore, when the shape of the position recognition unit 15 is a concave portion, as shown in FIG. 9, when the installation position of the concave portion for preventing the resist from spreading and spreading is a position about twice the effective diameter r1. It was found that the disturbance of the film thickness at the edge portion is transmitted to the curved surface portion 12. On the other hand, as shown in FIG. 10, it has been found that such a film thickness disturbance is not transmitted to the curved surface portion 12 when the recessed portion is set at a position that is approximately three times or more the effective diameter r1. Therefore, when the concave portion is formed as the position recognizing portion 15, it can be seen that it is preferable to form the concave portion at a position r3 that is at least approximately three times the effective diameter r1 of the effective curved surface portion 12a.
[0041]
In addition, when the rotation center of the resist coating substrate 10 and the rotation center of the spin coater chuck 20 do not coincide with each other, flutter occurs and a uniform film thickness distribution cannot be obtained. On the other hand, in this example, when spin coating is performed with the rotation center of the resist coated substrate 10 and the rotation center of the spin coater chuck 20 aligned so that the tolerance is within about 1 mm, for example, a uniform film thickness is obtained. Distribution can be obtained.
[0042]
Furthermore, the rotation center of the spin coater chuck 20 in the resist-coated substrate 10 in which the tolerance between the rotation center of the resist-coated substrate 10 and the outer shape center of the resist-coated substrate 10 is within about 0.5 mm, for example. And the center of rotation of the resist-coated substrate 10 and the center of rotation of the spin-coater chuck 20 when the tolerance between the mechanically coupled portion of the substrate to be coated 10 and the spin coater chuck 20 is, for example, within about 0.5 mm. Can be spin-coated so that a uniform film thickness distribution can be obtained.
[0043]
(About operation)
Next, the coating process in the case of applying a resist to the resist coating substrate having the above-described configuration will be described with reference to FIGS. 1 to 5 together with the operation of the resist coating substrate.
[0044]
The resist coating substrate 10 transported by a transport means (not shown) is placed on the spin coater chuck 20. At this time, since a recess is formed in the spin coater chuck 20, the resist-coated substrate 10 is uniquely held and fixed by being inserted into the recess. Then, the alignment operation of the spin coater chuck 20 is performed by the driving means 30 at a predetermined resist dropping position.
[0045]
Then, first, as shown in FIG. 1, the spin coater chuck 20 is rotated in the θ direction by the driving means 30 while a predetermined amount of resist L is dropped by the coating material application means 34.
[0046]
At this time, various control conditions such as the resist coating amount, the rotational speed of the spin coater chuck 20 and the environmental conditions so that the film thickness is uniform are controlled by the coating amount control means 36, the rotational speed control means 32, and the control means 40. Is done.
[0047]
Next, when the resist is dripped and rotated at a predetermined rotational speed, the resist L moves from the curved surface portion 12 through the peripheral curved surface portion 16 to the peripheral plane portion as shown by an arrow T shown in FIG. Will spread to 14.
[0048]
At this time, as shown in FIG. 3, when spreading on the curved surface portion 12 from X1 to X2, the resist (L shown in FIG. 2) spreads along the curved surface of the curved surface portion 12, and then the surrounding curved surface portion. When it reaches 16, the speed of the resist spreading at the curved surface portion 12 spreads at substantially the same speed or at a higher speed. As a result, when the curved surface portion 12 and the peripheral plane portion 14 are discontinuous surfaces, the film thickness becomes nonuniform due to the deceleration caused by the impact generated when the resist hits the peripheral plane portion 14. Thus, the resist spreads smoothly by the continuous surface of the peripheral curved surface portion 16.
[0049]
Further, in this case, the film thickness is uniform in the curved surface portion 12 and the surrounding flat surface portion 14, but in the surrounding curved surface portion 16, it is considered that a non-uniform region occurs in the boundary region.
[0050]
Therefore, after the resist coating, the peripheral flat surface portion 14 is cut as shown in FIG. 4 and the peripheral curved surface portion 16 is cut as shown in FIG. The resist coating substrate 10 can be configured.
[0051]
As described above, according to the present embodiment, the centrifugal force generated at the time of spin coating is uniformly transmitted to the resist on the curved surface portion, and there is no obstacle when the resist spreads on the periphery, and the uniform on the curved surface portion. A film thickness distribution is obtained. Further, the non-uniform thickness portion due to the stress when the resist droplets are separated from the base material occurs only in the peripheral curved surface portion.
[0052]
In addition, since the resist is not spread on the position recognition part by forming a concave or convex part as the position recognition part of the peripheral plane part of the substrate to be resist coated, the recognition accuracy of the position recognition part in the next exposure apparatus Will improve.
[0053]
Furthermore, since the rotation center of the resist-coated substrate having a curved surface coincides with the rotation center of the spin coater chuck, the centrifugal force generated during spin coating is uniformly transmitted to the resist on the curved surface portion, and is uniform on the curved surface portion. A film thickness distribution can be obtained.
[0054]
[Second Embodiment]
Next, a second embodiment according to the present invention will be described with reference to FIG. In the following, description of the substantially similar configuration of the first embodiment will be omitted, and only different parts will be described. FIG. 11 is an explanatory diagram showing the configuration of the resist-coated substrate of this example.
[0055]
In the first embodiment described above, the protruding height of the curved surface portion of the resist-coated substrate is formed so that the curved surface portion has a hemispherical shape, but in this example, the protruding height is reduced. By forming, it becomes a different shape according to the intended use of the resist coated substrate.
[0056]
Specifically, as shown in FIG. 11, the resist-coated substrate 60 of the present example forms a curved surface portion 62 and a surrounding curved surface portion 64 to form a curved surface portion 62 from the top portion X1 to X5, and from X5 to X6. The surrounding curved surface portion 64 is used. As in the first embodiment, in this example, the configuration of the peripheral plane portion is omitted.
[0057]
Even in such a configuration, after application of the resist, an effective diameter r12 of the effective curved surface portion where uniformity of the film thickness around X1 is required, although a film thickness non-uniform region occurs on the peripheral curved surface portion 64. In the curved surface portion 62 including the film thickness, the uniformity of the film thickness is achieved. Therefore, in the final processing step, by cutting the peripheral curved surface portion 64, the effective curved surface portion that requires the film thickness uniformity around X1 is required. Effective diameter r12 can be secured.
[0058]
For this reason, for example, if the area of the curved surface portion 62 is larger than the effective diameter r12, the area can be reduced to the area of the diameter r13 up to X7 in FIG.
[0059]
As described above, according to the present embodiment, while exhibiting the same effects as the first embodiment described above, by changing the protruding height of the curved surface portion or the length of the minor axis in the ellipse, The resist-coated substrate can have various shapes depending on the application.
[0060]
[Third Embodiment]
Next, a third embodiment according to the present invention will be described with reference to FIG. FIG. 12 is an explanatory view showing a resist-coated substrate of this example.
[0061]
In the first embodiment described above, the shape of the curved surface portion of the resist-coated substrate is hemispherical, but in this example, the curvature radius of the curved surface portion is changed.
[0062]
Specifically, as shown in FIG. 12, the curved surface portion 72 of the resist-coated substrate 70 of this example has a slightly convex shape from the spherical surface R1. Even in such a configuration, since the peripheral flat surface portion 74 and the peripheral curved surface portion 76 are formed as in the first embodiment, after the spin coating, the curved surface portion 72 has the resist film thickness of the resist film thickness. Uniformity can be achieved.
[0063]
[Fourth Embodiment]
Next, a fourth embodiment according to the present invention will be described with reference to FIG. FIG. 13 is an explanatory view showing a resist-coated substrate of this example.
[0064]
In the first embodiment described above, the configuration of the curved surface portion of the resist-coated substrate is a curved surface. However, in this example, the planar portion and the curved surface portion are partially combined. .
[0065]
In this case, the curvature radii of the curved surfaces at the curved surface portions may be different from each other.
[0066]
Specifically, the resist-coated substrate 80 of this example includes a curved surface portion 82, a peripheral curved surface portion 86, and a peripheral flat surface portion 84, as shown in FIG.
[0067]
The curved surface portion 82 includes a flat surface portion 82a, a first curved surface portion 82b, and a second flat surface portion 82c. Even with such a configuration, it is possible to obtain substantially the same operational effects as those of the first embodiment.
[0068]
Of course, the plane portion 82a and the second plane portion 82c may be configured as curved portions having different radii of curvature.
[0069]
[Fifth Embodiment]
Next, a fifth embodiment according to the present invention will be described with reference to FIGS. FIGS. 14A to 14C are explanatory views showing the resist-coated substrate of this example.
[0070]
In the first embodiment described above, the shape of the peripheral plane portion of the resist-coated substrate is formed in a substantially circular shape (as viewed from the top of the paper). The shape and the shape of the spin coater chuck are, for example, the shapes shown in FIGS. 14B and 14C.
[0071]
Specifically, the resist-coated substrate 100 of this example includes a curved surface portion 102, a peripheral flat surface portion 110, and a peripheral curved surface portion 104, and the peripheral flat surface portion 110 is substantially as shown in FIG. It is formed in an octagon shape. Further, the shape of the spin coater chuck is made to be a substantially octagonal shape in accordance with the shape of the resist coating substrate 100. Thereby, at the time of spin coating, the scattering distribution of the resist L can be defined in a predetermined direction.
[0072]
Similarly, the resist-coated substrate 120 shown in FIG. 14C has a curved surface portion 122, a peripheral flat surface portion 126, and a peripheral curved surface portion 124. The peripheral flat surface portion 126 is as shown in FIG. In addition, it is formed in a substantially square shape. Further, the shape of the spin coater chuck is made to be a substantially square shape in accordance with the shape of the resist coating substrate 120. Thereby, at the time of spin coating, the scattering distribution of the resist L can be defined in a predetermined direction. In particular, since the number of corners is small, the amount of concentration when scattering more intensively increases.
[0073]
Although the apparatus and method according to the present invention have been described in accordance with some specific embodiments thereof, those skilled in the art will recognize the embodiments described in the text of the present invention without departing from the spirit and scope of the present invention. Various modifications are possible. For example, in each of the embodiments described above, the peripheral plane portion is formed as a flat surface. However, the peripheral flat portion may be formed as a taper that is inclined downward as it goes outward from the periphery, and this may hinder the uniform thickness of the curved portion. It may be formed as a curved surface slightly curved to the extent that it does not occur, or may have a configuration partially having curved surfaces and corners.
[0074]
Further, the radius of curvature of each curved surface having radii R1 and R2 can be arbitrarily set as long as the above-described conditions are satisfied.
[0075]
Further, the position recognition unit may constitute a convex part at one point and a concave part at the other point. Further, even if each uneven part is formed discretely on concentric circles having different diameters, one concentric circle may be formed. Even if each unevenness | corrugation is formed at a different space | interval on the top, you may form as a groove | channel where each unevenness | corrugation continues.
[0076]
Further, in the above-described embodiment, the position recognition unit is configured to form unevenness or a position recognition mark. However, for example, a resist coated substrate 130 as shown in FIGS. Moreover, you may comprise a recessed part or a convex part, and a position recognition mark, respectively. Specifically, the resist coating base material 130 is a convex portion which is a curved surface portion 132 including an effective curved surface portion 132a, a peripheral flat surface portion 134, a peripheral curved surface portion 136, and a resist outflow direction control member provided on the peripheral flat surface portion 134. And a position recognition mark 136 provided on the peripheral plane part 134 outside the convex part or concave part 135. As a result, the direction in which the resist is spread and spread can be controlled by the convex portion or concave portion 135 as indicated by an arrow J. The resist will not spread. Thereby, position recognition in a later process becomes easier. The position recognition mark is preferably configured on the same plane as the surrounding plane portion.
[0077]
Furthermore, it goes without saying that examples including combinations of the above-described embodiments or combinations with the respective modifications are also included.
[0078]
【The invention's effect】
As described above, according to the present invention, the centrifugal force generated when the coating material is spin-coated on the substrate to be coated is uniformly transmitted to the coating material on the curved surface portion, and the coating material is applied to the periphery and the peripheral surface portion of the curved surface portion. There is no obstacle when spreading the coating, and a uniform film thickness distribution can be obtained on the curved surface. In addition, a non-uniform portion of the film thickness due to stress when the droplet of the coating material is separated from the substrate to be coated occurs only in the peripheral curved surface portion. Since the surrounding curved surface portion is outside the area of the effective curved surface portion required for the uniformity of the film thickness, there is no problem that it is disposed of by cutting or the like in a subsequent process.
[0079]
In addition, since the resist is not spread on the position recognition part by forming a concave part or a convex part as the position recognition part of the peripheral plane part of the substrate to be coated, the recognition accuracy of the position recognition part in the exposure apparatus in the next process is improved. improves.
[0080]
Further, since the rotation center of the substrate to be coated and the rotation center of the holding member are made to coincide with each other, the centrifugal force generated during the rotation application is uniformly transmitted to the coating material on the curved surface portion, and is uniform on the curved surface portion. A film thickness distribution can be obtained.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing an outline of the entire resist coating apparatus of the present invention.
2A is a plan view showing a resist-coated substrate processed by the resist coating apparatus of FIG. 1, and FIG. 2B is a partial view of the resist-coated substrate. It is the schematic explanatory drawing which showed the various cross sections.
FIG. 3 is an explanatory view showing an example of a processing step of a resist coating substrate processed by the resist coating apparatus of FIG. 1;
4 is an explanatory view showing an example of a processing step of a resist coating base material processed by the resist coating apparatus of FIG. 1; FIG.
5 is an explanatory view showing an example of a processing step of a resist coated substrate processed by the resist coating apparatus of FIG. 1; FIG.
FIG. 6 is a characteristic diagram showing the relationship between the rotational speed of the spin coater chuck and the resist film thickness when the resist viscosity is changed.
FIG. 7 is an explanatory diagram showing the relationship between the distance from the rotation center of the substrate and the film thickness in the positional relationship between the effective diameter of the effective curved surface portion and the boundary region position between the peripheral flat surface portion and the peripheral curved surface portion. .
FIG. 8 is an explanatory diagram showing the relationship between the distance from the rotation center of the resist-coated substrate and the film thickness when n-type silicon is used as the resist-coated substrate.
FIG. 9 is an explanatory diagram showing the relationship between the distance from the center of rotation of the resist-coated substrate and the film thickness when the position of the position recognition unit is about twice the effective diameter.
FIG. 10 is an explanatory diagram showing the relationship between the distance from the rotation center of the resist-coated substrate and the film thickness when the position of the position recognition unit is approximately three times the effective diameter.
FIG. 11 is an explanatory view showing an example of another embodiment of a resist coated substrate processed by the resist coating apparatus of the present invention.
FIG. 12 is an explanatory diagram showing an example of another embodiment of a resist-coated substrate processed by the resist coating apparatus of the present invention.
FIG. 13 is an explanatory view showing an example of another embodiment of a resist coated substrate processed by the resist coating apparatus of the present invention.
FIGS. 14A to 14C are explanatory views showing an example of another embodiment of a resist coating substrate and a spin coater chuck to be processed by the resist coating apparatus of the present invention.
FIGS. 15A and 15B are explanatory diagrams showing an example of another embodiment of a resist-coated substrate processed by the resist coating apparatus of the present invention.
FIG. 16 is an explanatory view showing processing in a conventional resist coating apparatus.
[Explanation of symbols]
1 resist coating apparatus 10 substrate to be coated with resist
12 curved surface portion 14 peripheral flat surface portion 16 peripheral curved surface portion 20 spin coater chuck 30 driving means 34 coating material applying means 37 viscosity control means 40 control means

Claims

A substrate to be coated having a curved surface portion on at least one surface, and at least a coating material is applied to the curved surface portion;
As the substrate to be coated itself rotates, the coating material dripped onto the top of the curved portion flows smoothly from the top toward the periphery of the curved portion while maintaining a substantially uniform film thickness. Provide the formed peripheral surface part ,
The peripheral surface portion is
A peripheral plane portion formed around the curved surface portion;
A peripheral curved surface portion formed in a boundary region between the peripheral flat surface portion and the curved surface portion so that the coating material flows down smoothly;
The to- be-coated base material characterized by including .

The curved surface portion includes an effective curved surface portion from a top center to which the dropped coating material adheres to a predetermined effective diameter required to have a substantially uniform film thickness distribution after coating the coating material. The substrate to be coated according to claim 1.

The first radius of the curved surface portion is formed to be approximately 1 to 10 times the second radius of the curved surface constituting the surrounding curved surface portion,
Forming a boundary region position between the peripheral flat surface portion and the peripheral curved surface portion where the inclination of the tangent line of the second radius is substantially zero at a position separated from at least approximately twice the effective diameter of the effective curved surface portion; The coated substrate according to claim 2, wherein:

The substrate to be coated according to any one of claims 1 to 3, wherein the substrate to be coated is formed of a resin.

The said to-be-coated base material is formed with the impurity member of a 1st conductivity type, The to-be-coated substrate as described in any one of Claim 1 thru | or 3 characterized by the above-mentioned.

The coated substrate according to claim 4, wherein the resin is made of polyolefin.

The substrate to be coated according to any one of claims 1 to 6, wherein a position recognition unit for recognizing a position of the substrate to be coated is formed on the peripheral plane part.

The substrate to be coated according to claim 7, wherein the position recognition unit is formed by a position recognition mark.

The substrate to be coated according to claim 7, wherein the position recognition part is formed by a concave part or a convex part.

The arrangement position of the position recognition unit is formed at a position spaced apart from at least approximately three times the effective diameter of the effective curved surface part, according to any one of claims 7 to 9. Substrate to be coated.

A method of applying a coating material by rotating a substrate to be coated on which a coating material is coated, and coating the coating material on the substrate to be coated having a curved portion on at least one surface,
The coating material is dropped on the top of the curved surface portion of the substrate to be coated, and the coating material dropped on the top as the substrate is rotated maintains a substantially uniform film thickness. An application material application step in which the application material is applied while smoothly flowing down from the top portion toward the peripheral surface portion around the curved surface portion;
The peripheral surface portion is a peripheral curved surface formed in a boundary region between the peripheral flat surface portion and the curved surface portion so that the peripheral flat surface portion formed around the curved surface portion and the coating material flow down gently. And
In the coating material application step, the coating material flows smoothly from the curved surface portion to the peripheral flat surface portion via the peripheral curved surface portion, while the coating material is the curved surface portion, the peripheral curved surface portion, and the surroundings. A coating material coating method comprising a step of coating the flat surface portion.

The coating material coating step includes a step of spin coating using a coating material having a composition that exhibits fluidity only when a predetermined shear stress is applied to the substrate to be coated. The coating material coating method according to claim 11.

The said coating material application | coating process includes the process of spin-coating using the coating material with a viscosity higher than at least about 15 (mPa * S) with respect to the said to-be-coated base material. The coating material application method.

The said coating material application | coating process forms the said to-be-coated base material with resin, and the said coating material is apply | coated, The coating material application | coating as described in any one of Claim 11 thru | or 13 characterized by the above-mentioned. Method.

The said coating material application | coating process forms the said to-be-coated base material with polyolefin, and the said coating material is apply | coated, The coating material application | coating as described in any one of Claim 11 thru | or 13 characterized by the above-mentioned. Method.

14. The coating according to claim 11, wherein in the coating material coating step, the substrate to be coated is formed of n-type silicon, and the coating material is coated. Material application method.

In the coating material coating step, the coated substrate is formed of n-type silicon, and the coating material is coated,
Wherein after coating material coating step, the coating material applying method according to any one of claims 11 to 13, characterized in that it comprises the step of base Kingu glass transition point Tg + 10 ° C. of the coating material.

18. The method according to claim 11, further comprising a position recognition step in exposure using a position recognition unit for recognizing a position of the substrate to be coated itself formed on the peripheral plane part. The coating material coating method according to one item.

19. The coating material application process according to claim 18, wherein the coating material coating step includes a step of coating the coating material so that the coating material does not spread by the position recognition unit formed by a concave portion or a convex portion. Method.

The coating material coating step includes a step of rotating and coating the rotation center of the substrate to be coated and the rotation center of a holding member that rotates while holding the substrate to be coated. The coating material applying method according to any one of claims 11 to 19.

A curved surface portion formed on at least one surface, a peripheral flat surface portion formed around the curved surface portion, and a resist dripped onto the top of the curved surface portion with rotation maintain a substantially uniform film thickness. An element to which the resist comprising the peripheral curved surface portion formed in a boundary region between the peripheral flat surface portion and the curved surface portion is applied so as to smoothly flow down from the top toward the periphery of the curved surface portion Is a method of manufacturing an element manufactured by performing a predetermined processing,
While the resist dripped at the top of the curved surface portion smoothly flows from the top of the curved surface portion toward the peripheral flat surface portion via the peripheral curved surface portion, the resist is removed from the curved surface portion and the peripheral curved surface. Application step applied to the portion and the peripheral plane portion;
Cutting the peripheral flat surface portion and the peripheral curved surface portion coated with the resist;
A method for manufacturing an element comprising: