JP3796555B2 - Chemically amplified positive resist material - Google Patents

Description

【０００９】
（但し、式中Ｒ¹、Ｒ²はそれぞれ水素原子又は炭素数１〜８の直鎖状又は分枝状のアルキル基又はアルケニル基であり、Ｒ³は水素原子又は炭素数１〜８の直鎖状又は分枝状のアルキル基又はアルケニル基、あるいは（Ｒ⁷）_s−ＣＯＯＨであり、Ｒ ⁷ は炭素数１〜１０の直鎖状又は分枝状のアルキレン基である。また、ｓは０又は１である。ｍ、ｎ、ｍ’、ｎ’はそれぞれｍ＋ｎ＝８、ｍ’＋ｎ’＝５を満足し、かつ各フェニル骨格中に少なくとも１つの水酸基を有するような数である。）
【００１０】
本発明のフェノール性水酸基を有する化合物の水酸基の水素原子を部分的に酸不安定基によって置換した溶解制御剤は、酸不安定基で保護されたアルカリ不溶性又はアルカリ難溶性の樹脂であって、該酸不安定基が解離したときにアルカリ可溶性となる樹脂、特に下記一般式（１０）で示されるポリヒドロキシスチレン、溶解阻止剤、酸発生剤とよく相溶し、酸発生剤や溶解阻止剤の分散性を増し、マトリクスを高密度化し、露光後に発生する酸の移動をミクロ的に均一化してコントロールすることによって、パターン形成後の解像性、短矩性を向上し、基盤面に残存するミクロスカムを減少させ、パターンのミクロ的な歪み（マイクロラフネス）を減少させるものであり、結果的に高解像性を有し、かつ凹凸のない（エッジラフネスの小さい）パターンを得ることができるという従来にない新しいコンセプトの化学増幅ポジ型レジスト材料の成分となることを知見し、本発明をなすに至ったものである。
【００１１】
【化６】

（式中、Ｒは酸不安定基であり、ｑ、ｒはそれぞれｑ／（ｑ＋ｒ）が０．０５〜０．８の範囲となる数である。）
【００１２】
従って、本発明は、
（Ａ）有機溶媒、
（Ｂ）酸不安定基で保護されたアルカリ不溶性又はアルカリ難溶性の樹脂であって、該酸不安定基が解離したときにアルカリ可溶性となる重量平均分子量が１，０００〜５０，０００である樹脂、
（Ｄ）酸発生剤、
（Ｅ）溶解制御剤として、重量平均分子量が１００〜１，０００で、かつ分子内にフェノール性水酸基を２つ以上有する化合物の該フェノール性水酸基の水素原子を酸不安定基により全体として平均１０〜８０％の割合で部分置換した化合物であって、上記一般式（１）又は（２）、あるいは下記式ｉ〜ｘｉｉで表わされる化合物から選ばれる１種又は２種以上を含有してなることを特徴とする化学増幅ポジ型レジスト材料
を提供する。
【化１７】

【化１８】

【００１３】
以下、本発明につき更に詳しく説明すると、本発明の化学増幅ポジ型レジスト材料は、溶解制御剤として、重量平均分子量が１００〜１，０００で、かつ分子内にフェノール性水酸基を２つ以上有する化合物の該フェノール性水酸基の水素原子を酸不安定基により全体として平均１０〜８０％の割合で部分置換した化合物を配合する。
【００１４】
上記化合物の重量平均分子量は１００〜１，０００、好ましくは１５０〜８００である。
【００１５】
また、フェノール性水酸基の水素原子の酸不安定基による部分置換率は、平均でフェノール性水酸基全体の１０〜８０％、好ましくは３０〜７５％であり、１０％に満たないと主にエッジラフネスが発生し、８０％を超えると主に解像性が低下する。
【００１６】
この場合、かかるフェノール性水酸基を有する化合物としては、下記一般式（１），（２）、あるいは下記式ｉ〜ｘｉｉで示されるものが用いられる。
【００１７】
【化７】

【００１８】
（但し、式中Ｒ¹、Ｒ²はそれぞれ水素原子又は炭素数１〜８の直鎖状又は分枝状のアルキル基又はアルケニル基であり、Ｒ³は水素原子又は炭素数１〜８の直鎖状又は分枝状のアルキル基又はアルケニル基、あるいは（Ｒ⁷）_s−ＣＯＯＨであり、Ｒ ⁷ は炭素数１〜１０の直鎖状又は分枝状のアルキレン基である。また、ｓは０又は１である。ｍ、ｎ、ｍ’、ｎ’はそれぞれｍ＋ｎ＝８、ｍ’＋ｎ’＝５を満足し、かつ各フェニル骨格中に少なくとも１つの水酸基を有するような数である。）
【化８】

【化１９】

【００１９】
上記式中Ｒ¹、Ｒ²としては、例えば水素原子、メチル基、エチル基、ブチル基、プロピル基、エチニル基、シクロヘキシル基、Ｒ³としては、例えばＲ¹、Ｒ²と同様なもの、あるいは−ＣＯＯＨ、−ＣＨ₂ＣＯＯＨ、−ＣＨ₂ＣＨ₂ＣＯＯＨが挙げられる。
【００２０】
ここで、フェノール性水酸基の水素原子と置換される酸不安定基としては、例えばメトキシエチル基、エトキシエチル基、ｎ−プロポキシエチル基、ｉｓｏ−プロポキシエチル基、ｎ−ブトキシエチル基、ｉｓｏ−ブトキシエチル基、ｔｅｒｔ−ブトキシエチル基、シクロヘキシロキシエチル基、メトキシプロピル基、エトキシプロピル基、エトキシイソプロピル基、エトキシイソブチル基、１−メトキシ−１−メチル−エチル基、１−エトキシ−１−メチル−エチル基等、下記一般式（１２）で表わされる基、ｔｅｒｔ−ブチル基等の炭素数１〜８の直鎖状又は分岐状のアルキル基、テトラヒドロピラニル基、テトラヒドロフラニル基、トリアルキルシリル基、β−ケトアルキル基等が挙げられる。
【００２１】
【化９】

（式中、Ｒ ¹¹ は炭素数１〜６の直鎖状又は分岐状のアルキル基であり、ｘは０又は１である。）
【００２２】
上記直鎖状、分岐状のアルキル基としては、メチル基、エチル基、プロピル基、イソプロピル基、ｎ−ブチル基、ｉｓｏ−ブチル基、ｔｅｒｔ−ブチル基等を例示でき、環状のアルキル基としては、シクロヘキシル基等を例示することができる。
【００２３】
ここで、上記式（１２）の酸不安定基として、例えばｔｅｒｔ−ブトキシカルボニル基、ｔｅｒｔ−ブトキシカルボニルメチル基等が挙げられる。また、上記トリアルキルシリル基としては、トリメチルシリル基、ｔｅｒｔ−ブチルジメチルシリル基などの各アルキル基の炭素数が１〜６のものが挙げられる。この場合、各アルキル基は互いに同一でも異なっていてもよい。更に、β−ケトアルキル基のアルキル基としては、炭素数１〜６のものが好ましい。
【００２４】
上記酸不安定基の中でも、特にエトキシエチル基、エトキシイソプロピル基、エトキシイソブチル基、ｎ−プロポキシエチル基、ｉｓｏ−プロポキシエチル基、ｎ−ブトキシエチル基、ｉｓｏ−ブトキシエチル基、ｔｅｒｔ−ブトキシエチル基、ｔｅｒｔ−ブトキシカルボニル基、ｔｅｒｔ−ブトキシカルボニルメチル基等が好ましい。
【００２５】
上記フェノール性水酸基を酸不安定基で部分置換した化合物（溶解制御剤）の配合量は、酸不安定基で保護されたアルカリ不溶性又はアルカリ難溶性の樹脂であって、該酸不安定基が解離したときにアルカリ可溶性となる樹脂１００重量部に対し０．１〜５０重量部、好ましくは１〜３０重量部であり、単独又は二種以上を混合して使用できる。配合量が０．１重量部に満たないと解像性の向上がない場合があり、５０重量部を超えるとパターンの膜減りが生じ、解像度が低下する場合がある。
【００２６】
本発明のレジスト材料は、公知の二成分系又は三成分系の化学増幅ポジ型レジスト材料として構成でき、上記溶解制御剤は、有機溶剤、ベースポリマーとしての酸不安定基で保護されたアルカリ不溶性又はアルカリ難溶性の樹脂であって、該酸不安定基が解離したときにアルカリ可溶性となる樹脂（以下、アルカリ可溶性となる樹脂という）、酸発生剤、場合によっては更に溶解阻止剤を主成分とするレジスト材料中に配合することができる。
【００２７】
ここで、有機溶剤としては、シクロヘキサノン、メチル−２−ｎ−アミルケトンなどのケトン類、３−メトキシブタノール、３−メチル−３−メトキシブタノール、１−メトキシ−２−プロパノール、１−エトキシ−２−プロパノールなどのアルコール類、プロピレングリコールモノメチルエーテル、エチレングリコールモノメチルエーテル、プロピレングリコールモノエチルエーテル、エチレングリコールモノエチルエーテル、プロピレングリコールジメチルエーテル、ジエチレングリコールジメチルエーテルなどのエーテル類、プロピレングリコールモノメチルエーテルアセテート、プロピレングリコールモノエチルエーテルアセテート、乳酸エチル、ピルビン酸エチル、酢酸ブチル、メチル−３−メトキシプロピオネート、エチル−３−エトキシプロピオネートなどのエステル類が挙げられ、これらの一種を単独で又は二種以上を混合して使用することができる。これらの中では、レジスト成分中の酸発生剤の溶解性が最も優れているジエチレングリコールジメチルエーテルや１−エトキシ−２−プロパノールが好ましく使用される。なお、有機溶剤の使用量は、アルカリ可溶性となる樹脂１００重量部に対し２００〜１，０００重量部、好ましくは４００〜８００重量部である。２００部より少ないと相溶性が低下し、成膜性に劣る場合が生じ、１，０００部を超えるとレジスト膜を形成した場合に薄膜になり、使用に供し得ない場合が生じる。
【００２８】
また、ベース樹脂であるアルカリ可溶性となる樹脂としては、下記一般式（１０）で示され、かつｑ／（ｑ＋ｒ）（保護置換率）が０．０５〜０．８となる範囲で分子中の水酸基が部分的に酸不安定基で保護された、分子量が１，０００〜５０，０００の範囲のポリヒドロキシスチレンが好適に使用される。
【００２９】
【化１０】

（式中、Ｒは酸不安定基であり、ｑ、ｒはそれぞれｑ／（ｑ＋ｒ）が０．０５〜０．８の範囲となる数である。）
【００３０】
ここで、上記式（１）中のＲは酸不安定基であり、上で説明した式（１１），（１２）で示される基、ｔｅｒｔ−ブチル基等の炭素数１〜８の直鎖状又は分岐状のアルキル基、テトラヒドロピラニル基、テトラヒドロフラニル基、トリアルキルシリル基及びβ−ケトアルキル基から選ばれるものが好適である。
【００３１】
また、ｑ、ｒはそれぞれｑ／（ｑ＋ｒ）（保護置換率）が０．０５〜０．８、好ましくは０．１〜０．５となる数であり、この範囲で部分的に水酸基が酸不安定基で置換される。なお、酸不安定基の置換率は５〜８０モル％、特に１０〜５０モル％のものが好適に使用される。
【００３２】
このアルカリ可溶性となる樹脂は、重量平均分子量が１，０００〜５０，０００、好ましくは２，０００〜３０，０００である。重量平均分子量及び置換率が上記範囲外になるとパターンプロファイルの劣化や感度が悪くなる場合が生じる。
【００３３】
更に、酸発生剤としては、公知のものを使用し得、例えばオニウム塩、スルホン酸エステル、ジアゾスルホン等が挙げられるが、オニウム塩が好ましく、オニウム塩としては、トリフェニルスルホニウムトリフレート誘導体、トリフェニルスルホニウムトシレート誘導体等が挙げられる。酸発生剤の添加量は、アルカリ可溶性となる樹脂１００重量部に対し１〜２０重量部、好ましくは２〜１０重量部である。
【００３４】
本発明材料には、更に溶解阻止剤を添加することができる。溶解阻止剤としては、分子内に一つ以上の酸不安定基を有するものが好ましい。溶解阻止剤としては公知のものを使用でき、具体的にはビスフェノールＡ誘導体、フェノールフタレイン誘導体等が例示されるが、特に水酸基の水素原子をｔｅｒｔ−ブトキシカルボニル基で置換した化合物が好ましく使用される。溶解阻止剤の添加量は、アルカリ可溶性となる樹脂１００重量部に対し５〜５０重量部、好ましくは１０〜３０重量部である。
【００３５】
更に、本発明のレジスト材料には、環境安定剤として窒素含有化合物を配合し得、また塗布性を向上させるために界面活性剤、基板よりの乱反射の影響を少なくするために吸光性材料を通常量で配合することができる。
【００３６】
この場合、窒素含有化合物としては、沸点１５０℃以上のアミン化合物もしくはアミド化合物が挙げられる。具体的には、アニリン、Ｎ−メチルアニリン、Ｎ，Ｎ−ジメチルアニリン、ｏ−トルイジン、ｍ−トルイジン、ｐ−トルイジン、２，４−ルチジン、キノリン、イソキノリン、ホルムアミド、Ｎ−メチルホルムアミド、Ｎ，Ｎ−ジメチルホルムアミド、アセトアミド、Ｎ−メチルアセトアミド、Ｎ，Ｎ−ジメチルアセトアミド、２−ピロリドン、Ｎ−メチルピロリドン、イミダゾール、α−ピコリン、β−ピコリン、γ−ピコリン、ｏ−アミノ安息香酸、ｍ−アミノ安息香酸、ｐ−アミノ安息香酸、１，２−フェニレンジアミン、１，３−フェニレンジアミン、１，４−フェニレンジアミン、２−キノリンカルボン酸、２−アミノ−４−ニトロフェノール、２−（ｐ−クロロフェニル）−４，６−トリクロロメチル−ｓ−トリアジンなどのトリアジン化合物が挙げられる。これらの中では、特にピロリドン、Ｎ−メチルピロリドン、ｏ−アミノ安息香酸、ｍ−アミノ安息香酸、ｐ−アミノ安息香酸、１，２−フェニレンジアミン、１，３−フェニレンジアミン、１，４−フェニレンジアミンが好ましく用いられる。
【００３７】
また、界面活性剤としては、パーフルオロアルキルポリオキシエチレンエタノール、フッ素化アルキルエステル、パーフルオロアルキルアミンオキサイド、パーフルオロアルキルＥＯ付加物等が挙げられ、吸光性材料としては、ジアリールスルホオキシド、ジアリールスルホン、９，１０−ジメチルアントラセン、９−フルオレノン等が挙げられる。
【００３８】
本発明のポジ型レジスト材料を使用してパターンを形成するには、公知のリソグラフィー技術を採用して行うことができ、例えばシリコンウェハー上へスピンコーティングし、０．５〜２．０μｍに塗布して８０〜１２０℃で３０〜２００秒間ベーク（プリベーク）した後、遠赤外線、電子線、Ｘ線等の高エネルギー線を照射して露光後、７０〜１２０℃で３０〜２００秒間ベーク（ポストエクスポージャベーク、ＰＥＢ）し、次いでアルカリ水溶液で現像することにより行うことができる。なお、本発明材料は、特に高エネルギー線の中でも２５４〜１９３ｎｍの遠赤外線光及び電子線による微細パターニングに最適である。
【００３９】
【発明の効果】
本発明の化学増幅ポジ型レジスト材料は、例えば遠紫外線、電子線、Ｘ線等の高エネルギー線、特にＫｒＦエキシマレーザーに感応し、感度、解像性、プラズマエッチング耐性に優れ、しかもレジストパターンの耐熱性に優れた微細加工技術に適した高解像性を有するもので、実用性の高いものである。
【００４０】
【実施例】
以下、実施例と比較例を示して本発明を具体的に説明するが、本発明は下記実施例に限定されるものではない。なお、各例中の部はいずれも重量部である。
〔実施例１〜２０，比較例１〜３２〕
下記式（Ｐｏｌｙｍｅｒｌ〜４）で示される部分的に水酸基がそれぞれｔｅｒｔ−ブトキシカルボニル基、ｔｅｒｔ−ブトキシ基、テトラヒドロピラニル基で保護されたポリヒドロキシスチレンと、下記式（ＰＡＧ１〜４）で示される酸発生剤と、下記式（ｉ）〜（ｘｉｉｉ）で示される化合物のフェノール性水酸基の水素原子を酸不安定基により全体として表１〜３に示される平均置換率で置換した化合物よりなる溶解制御剤を表１〜３に示す組成でジエチレングリコールジメチルエーテルに溶解し、レジスト組成物を調合し、更に各組成物を０．２μｍのテフロン製フィルターで濾過することにより、レジスト液を調製した。
【００４１】
得られたレジスト液をシリコンウェハー上へスピンコーティングし、０．８μｍの厚さに塗布した。次いで、このシリコンウェハーをホットプレートを用いて１００℃で９０秒間ベークした。
【００４２】
これをエキシマレーザーステッパー（ニコン社、ＮＳＲ−２００５ＥＸ８Ａ，ＮＡ−０．５）を用いて露光し、９０℃で６０秒間ベークを施し、２．３８％のテトラメチルアンモニウムヒドロキシドの水溶液で現像を行うと、ポジ型のパターンを得ることができた。
【００４３】
得られたレジストパターンを次のように評価した。結果を表１〜３に示す。
評価方法：
まず、感度（Ｅｔｈ）を求めた。次に０．３５μｍのラインアンドスペースを１：１で解像する露光量を最適露光量（Ｅｏｐ）として、この露光量における分離しているラインアンドスペースの最小線幅を評価レジストの解像度とした。解像したレジストパターンの形状は、走査型電子顕微鏡を用いて観察した。
【００４４】
また、０．２５μｍラインアンドスペースの凹凸（エッジラフネス）を走査型電子顕微鏡にて測定した。
【００４５】
表１〜３の結果より、本発明の化学増幅ポジ型レジスト材料は、高い解像力と凹凸のない（エッジラフネスの小さい）パターンを得ることができることが確認された。
【００４６】
【化１１】

【００４７】
【化１２】

【００４８】
【化１３】

【００４９】
【化１４】

【００５０】
【表１】

【００５１】
【表２】

【００５２】
【表３】

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a chemically amplified positive resist material suitable for microfabrication technology, which has high sensitivity to high energy rays such as deep ultraviolet rays, electron beams, and X-rays, and can be patterned by developing with an alkaline aqueous solution. .
[0002]
[Prior art and problems to be solved by the invention]
With the increasing integration and speed of LSIs, there is a need for finer pattern rules, and the light exposure currently used as a general-purpose technology approaches the intrinsic resolution limit derived from the wavelength of the light source. It's getting on. In light exposure using g-line (436 nm) or i-line (365 nm) as a light source, the pattern rule of about 0.5 μm is the limit, and the degree of integration of LSI manufactured using this rule is equivalent to 16 Mbit DRAM. It becomes. However, LSI prototypes have already reached this stage, and there is an urgent need to develop further miniaturization technology.
[0003]
Against this background, deep ultraviolet lithography is promising as a next-generation fine processing technology. Far-ultraviolet lithography can process 0.3 μm or less, and when a resist material with low light absorption is used, it is possible to form a pattern having sidewalls that are nearly perpendicular to the substrate.
[0004]
A recently developed acid-catalyzed chemical amplification positive resist material (JP-B-2-27660, JP-A-63-27829, etc.) uses a high-brightness KrF excimer laser as a deep ultraviolet light source, It is a resist material particularly promising for deep ultraviolet lithography, which has high sensitivity, resolution and dry etching resistance and has excellent characteristics.
[0005]
Such chemically amplified positive resist materials include two-component systems composed of alkali-soluble organic polymers and acid generators, and three-component systems composed of alkali-soluble polymers, dissolution inhibitors having acid labile groups, and acid generators. However, it is desired to further improve the sensitivity and resolution.
[0006]
Accordingly, an object of the present invention is to provide a chemically amplified positive resist material having high sensitivity and high resolution.
[0007]
Means for Solving the Problem and Embodiment of the Invention
The present inventor is a extensive result of extensive investigations, organic solvents, alkali insoluble or scarcely alkali-soluble resin protected with labile groups to achieve the above object, when dissociated in acid labile group In addition, a chemically amplified positive resist material containing an alkali-soluble resin, an acid generator, and optionally a dissolution inhibitor, further has a weight average molecular weight of 100 to 1,000 as a dissolution control agent, and an intramolecular A compound having two or more phenolic hydroxyl groups, particularly a hydrogen atom of the phenolic hydroxyl group of a compound having a phenolic hydroxyl group represented by the following general formulas (1) to (2) or formulas i to xii described below, When a compound partially substituted at a ratio of 10 to 80% on average as a whole by a stabilizing group is blended, the contrast of the dissolution rate of the resist film is enhanced, and the dissolution rate after exposure is particularly high. It has been found that a chemically amplified positive resist material having an increased degree of resolution and high resolution suitable for microfabrication technology and capable of exhibiting great power particularly in deep ultraviolet lithography can be obtained.
[0008]
[Formula 4]

[0009]
(In the formula, R ¹ and R ² are each a hydrogen atom or a linear or branched alkyl group or alkenyl group having 1 to 8 carbon atoms, and R ³ is a hydrogen atom or a straight chain having 1 to 8 carbon atoms. A linear or branched alkyl group or alkenyl group, or (R ⁷ ) _s —COOH, wherein R ⁷ is a linear or branched alkylene group having 1 to 10 carbon atoms, and s is 0 or 1. m, n, m ′, and n ′ are numbers that satisfy m + n = 8 and m ′ + n ′ = 5, respectively, and have at least one hydroxyl group in each phenyl skeleton .
[0010]
The dissolution control agent in which the hydrogen atom of the hydroxyl group of the compound having a phenolic hydroxyl group of the present invention is partially substituted with an acid labile group is an alkali-insoluble or hardly alkali-soluble resin protected with an acid labile group, Resins that become alkali-soluble when the acid labile group is dissociated, in particular, polyhydroxystyrene represented by the following general formula (10), a dissolution inhibitor, and an acid generator. By increasing the dispersibility of the substrate, increasing the density of the matrix, and controlling the movement of the acid generated after exposure to be microscopically uniform, the resolution and short rectangularity after pattern formation are improved and remain on the substrate surface. This reduces the amount of micro-cams that occur and reduces micro-roughness of the pattern. As a result, it has high resolution and no irregularities (small edge roughness). ) Pattern found that the components of the resist composition of the new concept unprecedented that can be obtained, in which the present invention has been accomplished.
[0011]
[Chemical 6]

(In the formula, R is an acid labile group, and q and r are numbers in which q / (q + r) is in the range of 0.05 to 0.8.)
[0012]
Therefore, the present invention
( A) an organic solvent,
(B) An alkali-insoluble or hardly alkali-soluble resin protected with an acid labile group, and having a weight average molecular weight of 1,000 to 50,000 that becomes alkali-soluble when the acid labile group dissociates. resin,
(D) an acid generator,
(E) As a dissolution control agent, a compound having a weight average molecular weight of 100 to 1,000 and having two or more phenolic hydroxyl groups in the molecule has an average of 10 hydrogen atoms of the phenolic hydroxyl groups as a whole due to acid labile groups. It is a compound partially substituted at a ratio of ˜80%, and contains one or more selected from compounds represented by the above general formula (1) or (2) or the following formulas i to xii A chemically amplified positive resist material is provided.
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[0013]
Hereinafter, the present invention will be described in more detail. The chemically amplified positive resist material of the present invention is a compound having a weight average molecular weight of 100 to 1,000 as a dissolution control agent and having two or more phenolic hydroxyl groups in the molecule. A compound in which the hydrogen atoms of the phenolic hydroxyl group are partially substituted with an acid labile group in an average of 10 to 80% as a whole is blended.
[0014]
The compound has a weight average molecular weight of 100 to 1,000, preferably 150 to 800.
[0015]
Moreover, the partial substitution rate of the hydrogen atom of the phenolic hydroxyl group with an acid labile group is 10 to 80%, preferably 30 to 75% of the entire phenolic hydroxyl group on average, and is mainly less than 10% when it is less than 10%. When it exceeds 80%, the resolution is mainly deteriorated.
[0016]
In this case, as the compound having a phenolic hydroxyl group, those represented by the following general formulas (1) and (2) or the following formulas i to xii are used.
[0017]
[Chemical 7]

[0018]
(In the formula, R ¹ and R ² are each a hydrogen atom or a linear or branched alkyl group or alkenyl group having 1 to 8 carbon atoms, and R ³ is a hydrogen atom or a straight chain having 1 to 8 carbon atoms. A linear or branched alkyl group or alkenyl group, or (R ⁷ ) _s —COOH, wherein R ⁷ is a linear or branched alkylene group having 1 to 10 carbon atoms, and s is 0 or 1. m, n, m ′, and n ′ are numbers that satisfy m + n = 8 and m ′ + n ′ = 5, respectively, and have at least one hydroxyl group in each phenyl skeleton .
[Chemical 8]

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[0019]
In the above formula, R ¹ and R ² are, for example, a hydrogen atom, a methyl group, an ethyl group, a butyl group, a propyl group, an ethynyl group, a cyclohexyl group, and R ³ is, for example, the same as R ¹ and R ² , or -COOH, -CH ₂ COOH, include -CH ₂ CH ₂ COOH.
[0020]
Here, examples of the acid labile group substituted for the hydrogen atom of the phenolic hydroxyl group include a methoxyethyl group, an ethoxyethyl group, an n-propoxyethyl group, an iso-propoxyethyl group, an n-butoxyethyl group, and an iso-butoxy group. Ethyl group, tert-butoxyethyl group, cyclohexyloxyethyl group, methoxypropyl group, ethoxypropyl group, ethoxyisopropyl group, ethoxyisobutyl group, 1-methoxy-1-methyl-ethyl group, 1-ethoxy-1-methyl-ethyl group A group represented by the following general formula (12), a linear or branched alkyl group having 1 to 8 carbon atoms such as a tert-butyl group, a tetrahydropyranyl group, a tetrahydrofuranyl group, a trialkylsilyl group, A β-ketoalkyl group and the like can be mentioned.
[0021]
[Chemical 9]

(In the formula , R ¹¹ is a linear or branched alkyl group having 1 to 6 carbon atoms, and x is 0 or 1.)
[0022]
Examples of the linear or branched alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an iso-butyl group, and a tert-butyl group. As the cyclic alkyl group, And a cyclohexyl group.
[0023]
Here, as the acid labile groups of the above following formula (12), for example, tert- butoxycarbonyl group, etc. tert- butoxycarbonyl methyl group. Examples of the trialkylsilyl group include those having 1 to 6 carbon atoms in each alkyl group such as a trimethylsilyl group and a tert-butyldimethylsilyl group. In this case, each alkyl group may be the same as or different from each other. Further, the alkyl group of the β-ketoalkyl group is preferably one having 1 to 6 carbon atoms.
[0024]
Among the above acid labile groups, ethoxyethyl group, ethoxyisopropyl group, ethoxyisobutyl group, n-propoxyethyl group, iso-propoxyethyl group, n-butoxyethyl group, iso-butoxyethyl group, tert-butoxyethyl group , Tert-butoxycarbonyl group, tert-butoxycarbonylmethyl group and the like are preferable.
[0025]
The compounding amount of the compound in which the phenolic hydroxyl group is partially substituted with an acid labile group (dissolution control agent) is an alkali-insoluble or hardly alkali-soluble resin protected with an acid labile group, It is 0.1-50 weight part with respect to 100 weight part of resin which becomes alkali-soluble when dissociated, Preferably it is 1-30 weight part, and can be used individually or in mixture of 2 or more types. If the blending amount is less than 0.1 parts by weight, resolution may not be improved. If it exceeds 50 parts by weight, the film thickness of the pattern may be reduced and resolution may be lowered.
[0026]
The resist material of the present invention can be constructed as a known two-component or three-component chemically amplified positive resist material, and the above-mentioned dissolution control agent is an organic solvent, an alkali insoluble protected with an acid labile group as a base polymer. Or an alkali-poorly soluble resin that becomes alkali-soluble when the acid labile group is dissociated (hereinafter referred to as an alkali-soluble resin), an acid generator, and in some cases, a dissolution inhibitor. In the resist material.
[0027]
Here, examples of the organic solvent include ketones such as cyclohexanone and methyl-2-n-amyl ketone, 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, and 1-ethoxy-2- Alcohols such as propanol, propylene glycol monomethyl ether, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether, diethylene glycol dimethyl ether, and other ethers, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether Acetate, ethyl lactate, ethyl pyruvate, butyl acetate, methyl-3-methoxypropionate, ethyl-3 Include esters such as ethoxy propionate can be used these kind alone or as a mixture of two or more. Among these, diethylene glycol dimethyl ether and 1-ethoxy-2-propanol, which have the highest solubility of the acid generator in the resist component, are preferably used. In addition, the usage-amount of an organic solvent is 200-1,000 weight part with respect to 100 weight part of resin which becomes alkali-soluble, Preferably it is 400-800 weight part. When the amount is less than 200 parts, the compatibility is lowered and the film formability is inferior. When the amount exceeds 1,000 parts, the resist film is formed into a thin film and cannot be used.
[0028]
Moreover, as resin which becomes alkali-soluble which is a base resin, it is shown in the following general formula (10), and q / (q + r) (protective substitution rate) is in the range of 0.05 to 0.8 in the molecule. Polyhydroxystyrene having a molecular weight in the range of 1,000 to 50,000 in which the hydroxyl group is partially protected with an acid labile group is preferably used.
[0029]
[Chemical Formula 10]

(In the formula, R is an acid labile group, and q and r are numbers in which q / (q + r) is in the range of 0.05 to 0.8.)
[0030]
Here, R in the above formula (1) is an acid labile group, and is a straight chain having 1 to 8 carbon atoms such as the groups represented by formulas (11) and (12) described above and a tert-butyl group. Preferred are those selected from a linear or branched alkyl group, a tetrahydropyranyl group, a tetrahydrofuranyl group, a trialkylsilyl group, and a β-ketoalkyl group.
[0031]
In addition, q and r are numbers in which q / (q + r) (protective substitution rate) is 0.05 to 0.8, preferably 0.1 to 0.5. Substituted with labile groups. The acid labile group having a substitution rate of 5 to 80 mol%, particularly 10 to 50 mol% is preferably used.
[0032]
The resin that becomes alkali-soluble has a weight average molecular weight of 1,000 to 50,000, preferably 2,000 to 30,000. If the weight average molecular weight and the substitution rate are out of the above ranges, the pattern profile may deteriorate and the sensitivity may deteriorate.
[0033]
Further, as the acid generator, known ones can be used, and examples thereof include onium salts, sulfonic acid esters, diazo sulfones, etc., and onium salts are preferable, and examples of onium salts include triphenylsulfonium triflate derivatives, And phenylsulfonium tosylate derivatives. The addition amount of the acid generator is 1 to 20 parts by weight, preferably 2 to 10 parts by weight with respect to 100 parts by weight of the resin that becomes alkali-soluble.
[0034]
A dissolution inhibitor can be further added to the material of the present invention. As the dissolution inhibitor, those having one or more acid labile groups in the molecule are preferable. Known dissolution inhibitors can be used, and specific examples include bisphenol A derivatives and phenolphthalein derivatives. Particularly, compounds in which the hydrogen atom of the hydroxyl group is substituted with a tert-butoxycarbonyl group are preferably used. The The addition amount of the dissolution inhibitor is 5 to 50 parts by weight, preferably 10 to 30 parts by weight, based on 100 parts by weight of the alkali-soluble resin.
[0035]
Furthermore, the resist material of the present invention can be blended with a nitrogen-containing compound as an environmental stabilizer, and a surfactant or a light-absorbing material is usually used to reduce the influence of irregular reflection from the substrate in order to improve coating properties. It can mix | blend in quantity.
[0036]
In this case, examples of the nitrogen-containing compound include amine compounds or amide compounds having a boiling point of 150 ° C. or higher. Specifically, aniline, N-methylaniline, N, N-dimethylaniline, o-toluidine, m-toluidine, p-toluidine, 2,4-lutidine, quinoline, isoquinoline, formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, 2-pyrrolidone, N-methylpyrrolidone, imidazole, α-picoline, β-picoline, γ-picoline, o-aminobenzoic acid, m- Aminobenzoic acid, p-aminobenzoic acid, 1,2-phenylenediamine, 1,3-phenylenediamine, 1,4-phenylenediamine, 2-quinolinecarboxylic acid, 2-amino-4-nitrophenol, 2- (p -Chlorophenyl) -4,6-trichloromethyl-s-triazine and the like Jin compounds. Among these, pyrrolidone, N-methylpyrrolidone, o-aminobenzoic acid, m-aminobenzoic acid, p-aminobenzoic acid, 1,2-phenylenediamine, 1,3-phenylenediamine, 1,4-phenylene Diamine is preferably used.
[0037]
Examples of the surfactant include perfluoroalkyl polyoxyethylene ethanol, fluorinated alkyl ester, perfluoroalkylamine oxide, perfluoroalkyl EO adduct, etc., and light-absorbing materials include diaryl sulfoxide, diaryl sulfone. 9,10-dimethylanthracene, 9-fluorenone and the like.
[0038]
In order to form a pattern using the positive resist material of the present invention, a known lithography technique can be employed, for example, spin coating onto a silicon wafer and application to 0.5 to 2.0 μm. Bake (pre-bake) at 80 to 120 ° C. for 30 to 200 seconds, then irradiate with high energy rays such as far-infrared rays, electron beams and X-rays, and after exposure, bake at 70 to 120 ° C. for 30 to 200 seconds (post-exposure) Jabake, PEB) followed by development with an aqueous alkaline solution. The material of the present invention is particularly suitable for fine patterning using far-infrared rays of 254 to 193 nm and electron beams among high energy rays.
[0039]
【The invention's effect】
The chemically amplified positive resist material of the present invention is sensitive to high energy rays such as deep ultraviolet rays, electron beams, and X-rays, particularly KrF excimer lasers, and is excellent in sensitivity, resolution, and plasma etching resistance. It has high resolution suitable for microfabrication technology with excellent heat resistance, and is highly practical.
[0040]
【Example】
EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated concretely, this invention is not limited to the following Example. In addition, all the parts in each example are parts by weight.
[Examples 1-20, Comparative Examples 1-32]
A polyhydroxystyrene partially protected by a tert-butoxycarbonyl group, a tert-butoxy group, and a tetrahydropyranyl group represented by the following formulas (Polymerl to 4 ) and the following formulas (PAG1 to 4 ): Dissolution comprising an acid generator and a compound in which the hydrogen atoms of the phenolic hydroxyl groups of the compounds represented by the following formulas (i) to (xiii) are substituted by the acid labile groups as a whole at the average substitution rates shown in Tables 1 to 3 A resist solution was prepared by dissolving the control agent in diethylene glycol dimethyl ether with the composition shown in Tables 1 to 3, preparing a resist composition, and further filtering each composition through a 0.2 μm Teflon filter.
[0041]
The obtained resist solution was spin-coated on a silicon wafer and applied to a thickness of 0.8 μm. Next, this silicon wafer was baked at 100 ° C. for 90 seconds using a hot plate.
[0042]
This is exposed using an excimer laser stepper (Nikon Corporation, NSR-2005EX8A, NA-0.5), baked at 90 ° C. for 60 seconds, and developed with an aqueous solution of 2.38% tetramethylammonium hydroxide. A positive pattern was obtained.
[0043]
The obtained resist pattern was evaluated as follows. The results are shown in Tables 1-3.
Evaluation methods:
First, sensitivity (Eth) was determined. Next, the exposure amount for resolving 0.35 μm line and space at 1: 1 is the optimum exposure amount (Eop), and the minimum line width of the separated line and space at this exposure amount is the resolution of the evaluation resist. . The shape of the resolved resist pattern was observed using a scanning electron microscope.
[0044]
Moreover, the unevenness (edge roughness) of a 0.25 micrometer line and space was measured with the scanning electron microscope.
[0045]
From the results of Tables 1 to 3, it was confirmed that the chemically amplified positive resist material of the present invention can obtain a pattern having high resolution and no irregularities (small edge roughness).
[0046]
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[0047]
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[0048]
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[0049]
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[0050]
[Table 1]

[0051]
[Table 2]

[0052]
[Table 3]

Claims (4)

(A) an organic solvent,
(B) An alkali-insoluble or hardly alkali-soluble resin protected with an acid labile group, and having a weight average molecular weight of 1,000 to 50,000 that becomes alkali-soluble when the acid labile group dissociates. resin,
(D) an acid generator,
(E) As a dissolution control agent, a compound having a weight average molecular weight of 100 to 1,000 and having two or more phenolic hydroxyl groups in the molecule has an average of 10 hydrogen atoms of the phenolic hydroxyl groups as a whole due to acid labile groups. a compound partially substituted in a ratio of 80%, chemically amplified positive resist material characterized by comprising a containing one or more kinds selected from compounds represented by the following formula.

(In the formula, R ¹ and R ² are each a hydrogen atom or a linear or branched alkyl group or alkenyl group having 1 to 8 carbon atoms, and R ³ is a hydrogen atom or a straight chain having 1 to 8 carbon atoms. A linear or branched alkyl group or alkenyl group, or (R ⁷ ) _s —COOH, wherein R ⁷ is a linear or branched alkylene group having 1 to 10 carbon atoms, and s is 0 or 1. m, n, m ′, and n ′ are numbers that satisfy m + n = 8 and m ′ + n ′ = 5, respectively, and have at least one hydroxyl group in each phenyl skeleton . (A) an organic solvent,
(B) An alkali-insoluble or hardly alkali-soluble resin protected with an acid labile group, and having a weight average molecular weight of 1,000 to 50,000 that becomes alkali-soluble when the acid labile group dissociates. resin,
(D) an acid generator,
(E) As a dissolution control agent, a compound having a weight average molecular weight of 100 to 1,000 and having two or more phenolic hydroxyl groups in the molecule has an average of 10 hydrogen atoms of the phenolic hydroxyl groups as a whole due to acid labile groups. a compound partially substituted in a ratio of 80%, chemically amplified positive resist material characterized by comprising a containing one or more kinds selected from compounds represented by the following formula.

Furthermore, (C) the following formula as a dissolution inhibitor

The chemically amplified positive resist material according to claim 1 or 2, wherein a bisphenol A derivative represented by the formula: As the above resin, the hydrogen atom of the hydroxyl group in the molecule is partially acid-free within the range represented by the following general formula (10) and q / (q + r) (protective substitution rate) being 0.05 to 0.8. The chemically amplified positive resist material according to claim 1, 2 or 3, wherein polyhydroxystyrene having a weight average molecular weight of 1,000 to 50,000, which is protected by a stable group, is used.

(In the formula, R is an acid labile group, and q and r are numbers in which q / (q + r) is in the range of 0.05 to 0.8.)