JP2004317754A - 1,2-naphthoquinone-2-diazide sulfonate photosensitive agent and photoresist composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a 1,2-naphthoquinone-2-diazide sulfonate photosensitive agent which has high solubility, which can be manufactured at a low cost, which satisfies both of the sensitivity and the residual film rate and which is useful as a photosensitive agent of a photoresist for the manufacture of a semiconductor integrated circuit, a liquid crystal display, an EL (electroluminescence) display or the like, in particular, a liquid crystal display, and to provide a photoresist composition. <P>SOLUTION: The 1,2-naphthoquinone-2-diazide sulfonate photosensitive agent is expressed by general formula (I). In formula (I), each of R<SB>1</SB>, R<SB>2</SB>, R<SB>3</SB>and R<SB>4</SB>independently represents a 2-9C alkyl group, each of D<SB>1</SB>to D<SB>8</SB>is independent from others and at least two of them are 1,2-naphthoquinone-2-diazide sulfonyl groups, at least one of the rest is an aryl sulfonyl group and the rest represents a hydrogen atom. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【００１４】
但し、一般式（Ｉ）中、Ｒ_１、Ｒ_２、Ｒ_３及びＲ_４は互いに独立に、炭素数２から９までのアルキル基を表わし、Ｄ_１〜Ｄ_８は互いに独立で、少なくとも２個は１，２−ナフトキノン−２−ジアジドスルホニル基であると共に残りの少なくとも１個はアリールスルホニル基であり、他の残りは水素原子を表す。
【００１５】
本発明の第２の態様は、第１の態様の１，２−ナフトキノン−２−ジアジドスルホン酸エステル系感光剤と、アルカリ可溶性樹脂とを含有することを特徴とするホトレジスト組成物にある。
【００１６】
かかる本発明の一般式（Ｉ）で示される１，２−ナフトキノン−２−ジアジドスルホン酸エステル系感光剤は、製造が容易で、尚且つ安価で大量に製造が可能であると同時に、アリールスルホニル基を有しないものと比較して感度がさらに向上したものである。また、この感光剤を含有する本発明のホトレジスト組成物は、液晶ディスプレイの製造における微細加工に有用な、十分に満足しうる程度の感度を有し、アリールスルホニル基を有しないものと比較して感度及び残膜率がさらに向上したものであり、保存安定性にも優れた実用性の極めて高いものであり、特に、ｉ線露光用として有用である。
【００１７】
【発明の実施の形態】
以下、本発明をさらに詳細に説明する。
【００１８】
本発明の１，２−ナフトキノン−２−ジアジドスルホン酸エステル系感光剤は、レゾルシノールと炭素数３〜１０のアルデヒドから選択される少なくとも１種のアルデヒドとの縮合反応によって得られる下記一般式（ＩＩ）で示される化合物を主体とする多価フェノールに、１，２−ナフトキノン−２−ジアジドスルホニルハライド及びアリールスルホニルハライドを酸中和剤の存在下に反応させることにより製造することができる。ここで、本発明において、多価フェノールは、一般式（ＩＩ）示される化合物（異性体を含む場合がある）と、その他の化合物を含む混合物である。本発明では、ＧＰＣ測定における一般式（ＩＩ）で示される化合物より保持時間が短い成分の含有量が１０％以下である多価フェノールを用いるのが好ましい。高分子量成分が多いものを用いると、製造された感光剤の溶解性が低下するからである。
【００１９】
ここで、本発明の１，２−ナフトキノン−２−ジアジドスルホン酸エステル系感光剤を製造する際には、１，２−ナフトキノン−２−ジアジドスルホニルハライド及びアリールスルホニルハライドは同時に反応させてもよいが、２段階で反応させてもよいことはいうまでもない。
【００２０】
また、１，２−ナフトキノン−２−ジアジドスルホニルハライド及びアリールスルホニルハライドを反応させるに際して、両者のモル比は、３：１〜１：１、すなわち、アリールスルホニルハライドが、モル比率で１／４〜１／２であるのが好ましい。
【００２１】
【化３】

【００２２】
ただし、一般式（ＩＩ）でＲ_１、Ｒ_２、Ｒ_３及びＲ_４は互いに独立に炭素数２〜９のアルキル基を表わす。
【００２３】
一般式（ＩＩ）で表わされる化合物は４モルのレゾルシノールと４モルのアルデヒドが環状に縮合した化合物である。なお、この化合物の合成法についてはＡ． Ｇ． Ｓｖｅｒｋｅｒ Ｈｏｂｅｒｇの報告（Ｊ． Ｏｒｇ． Ｃｈｅｍ．， ｖｏｌ．４５， ４４９８（１９８０））やＹ． Ａｏｙａｍａ等の報告（Ｊ． Ａｍ． Ｃｈｅｍ． Ｓｏｃ．， ｖｏｌ．１１１， ５３９７（１９８９））などに詳しく記載されているので、容易に合成できるが、レゾルシノールとアルデヒドの反応後、更にフェノールの誘導体を作り精製してからフェノール化合物に戻すなどの工程を含み、非常に煩雑で実際的でない。
【００２４】
以下に好ましい合成例を示す。
【００２５】
レゾルシノールとアルデヒドを、水あるいはメタノールやエタノールのようなアルコール溶媒、好ましくはアルコール溶媒、特に好ましくはメタノール溶媒中で、酸触媒、好ましくは塩酸触媒を用いて反応させる。レゾルシノールとアルデヒドのモル比は通常１：０．６〜１．５が好ましい。反応後はゆっくり結晶を析出させる。例えば反応溶媒にメタノールを用いた場合は、反応後水を加え結晶を析出させるが、水を加えた後、加熱してから再びゆっくり冷却して高分子量成分を形成しないようにゆっくり結晶を成長させ、更に水を加えて結晶を析出させるようにすると、得られる結晶はＧＰＣで高分子量成分（一般式（ＩＩ）で示される化合物より保持時間が短い成分）が１０％以下の多価フェノールが容易に得られる。また、必要により再結晶する事もできる。
【００２６】
一般式（ＩＩ）で示される化合物を主体とする多価フェノールはＧＰＣ（ｇｅｌｐｅｒｍｅａｔｉｏｎ ｃｈｒｏｍａｔｏｇｒａｐｈｙ）で測定して一般式（ＩＩ）で示される化合物より保持時間が短い成分（高分子量成分）が１０％以下であり、低分子量成分は実質的に含まないのが好ましいので、一般式（Ｉ）で示される化合物を主体とする多価フェノールは、純度が９０％以上が好ましい。純度が９０％未満では、得られた１，２−ナフトキノン−２−ジアジドスルホン酸エステル系感光剤の有機溶媒に対する溶解度が低く、溶媒に溶けなかったり、溶けても経時的に析出して、ノボラック等のアルカリ可溶性樹脂と組み合わせるホトレジストの感光剤としては使用できない。反応後析出させた結晶の純度が９０％未満の場合は、再結晶などの手段により純度を９０％以上にする事ができる。
【００２７】
ここで、ＧＰＣの測定条件は以下の通りである。
カラム：Ｓｈｏｄｅｘ ＧＰＣ ＫＦ−８０２×１本＋ＫＦ−８０１×３本
カラム温度：４０℃
検出波長：２５４ｎｍ
移動層：ＴＨＦ
移動層の流量：１．０ｍｌ／ｍｉｎ．
【００２８】
一般式（ＩＩ）で示される化合物を主体とする多価フェノールはｉ線（３６５ｎｍ）における吸収がほとんどなく、ｉ線露光用ホトレジストの感光剤の原料多価フェノールとして特に好適である。
【００２９】
ここで使用される１，２−ナフトキノン−２−ジアジドスルホニルハライドとしては、１，２−ナフトキノン−２−ジアジド−４−スルホニルクロリド、１，２−ナフトキノン−２−ジアジド−５−スルホニルクロリドおよび１，２−ナフトキノン−２−ジアジド−６−スルホニルクロリドから選択される少なくとも１種であるが、価格的な面で１，２−ナフトキノン−２−ジアジド−５−スルホニルクロリドが有利に用いられる。
【００３０】
また、アリールスルホニルハライドとしては、ベンゼンスルホニルクロリド、ベンゼンスルホニルブロミド、トルエンスルホニルクロリド、トルエンスルホニルブロミド、メシチレンスルホニルクロリドなどを挙げることができる。
【００３１】
一般式（ＩＩ）で示される化合物を主体とする多価フェノールと１，２−ナフトキノン−２−ジアジドスルホニルハライド及びアリールスルホニルハライドとの反応は、一般的に、例えば、アセトン、メチルエチルケトン、ジオキサン、テトラヒドロフラン、１，３−ジオキソラン、γ−ブチロラクトン、炭酸プロピレン、Ｎ−メチルピロリドン等から選択される少なくとも１種の有機溶媒中、酸中和剤の存在下で行われる。かかる酸中和剤としては、好ましくは有機アミン、例えばエチルアミン、ジエチルアミン、トリエチルアミン、ジイソプロピルアミン、トリプロピルアミン、トリイソブチルアミン、トリエタノールアミン、モノメチルジシクロヘキシルアミン、Ｎ−メチルピペリジン、Ｎ−メチルモルホリン、Ｎ−メチルピロリジン、１，４−ジメチルピペラジン、ピリジン、Ｎ，Ｎ−ジメチルアニリン、Ｎ，Ｎ−ジメチルアミノピリジン等を挙げることが出来る。
【００３２】
反応は通常、（１）多価フェノールと１，２−ナフトキノン−２−ジアジドスルホニルハライド及びアリールスルホニルハライドを有機溶媒に溶解後、これに有機アミンあるいは有機アミンを溶媒に溶解させた溶液を添加するか、（２）多価フェノールと１，２−ナフトキノン−２−ジアジドスルホニルハライドを有機溶媒に溶解後、これに使用ハライド相当の有機アミンあるいは有機アミンを溶媒に溶解させた溶液を添加し、次にアリールスルホニルハライドを添加し、更に相当する有機アミンを添加する。ここで、加えるハライドの順番は逆でも良い。或いは、（３）多価フェノールと有機アミンとを溶媒に溶解後、これに１，２−ナフトキノン−２−ジアジドスルホニルハライド及びアリールスルホニルハライド、或いはこれらのハライドを溶媒に溶解させたものを順次、或いは同時に添加するなどし、次いで１０分〜５時間程度攪拌し縮合反応を行なわせる。添加およびその後の縮合反応は、−１０℃〜５０℃、好ましくは１０℃〜４０℃の温度で、１０分〜３時間程度をかけて行なう。
【００３３】
多価フェノールに対する１，２−ナフトキノン−２−ジアジドスルホニルハライドの使用量は、多価フェノール１モルに対して２〜６モルが好ましく、さらに好ましくは２．５〜４モルである。２モル未満ではアルカリ可溶性樹脂と組み合わせたホトレジストの残膜率が低く、６モルより多いと低感度となり好ましくない。なお、アリールスルホニルハライドは、使用する１，２−ナフトキノン−２−ジアジドスルホニルハライドに対して必要量用いればよく、好ましくは、１，２−ナフトキノン−２−ジアジドスルホニルハライド及びアリールスルホニルハライドのモル比が３：１〜１：１であるのが望ましい。
【００３４】
また、酸中和剤の使用量は、（１，２−ナフトキノン−２−ジアジドスルホニル−ジアジドスルホニルハライド＋アリールスルホニルハライド）１モルに対し、通常、１．０〜１．５モル、好ましくは、１．０５〜１．２モルである。１．０モル未満では１，２−ナフトキノン−２−ジアジドスルホニル−ジアジドスルホニルハライド及び／或いはアリールハライドが残り易く、１．５モルより多いと過剰の酸中和剤により１，２−キノンジアジド基が分解し易い。使用溶媒量は（１，２−ナフトキノン−２−ジアジドスルホニルハライド＋アリールスルホニルハライド＋多価フェノール化合物）の重量にして２〜１０重量倍、好ましくは３〜５重量倍である。２重量倍未満では、反応成分が溶解しなかったり、本発明の目的である保存安定性が悪くなったりし、１０重量倍より多いと、再沈させるための水も多量に用いなければならなく、経済的でなくなる。
【００３５】
反応混合物を純水、メタノールのような生成した感光剤の貧溶媒の中に注ぐことにより１，２−ナフトキノン−２−ジアジドスルホン酸エステル系感光剤が析出する。析出した１，２−ナフトキノン−２−ジアジドスルホン酸エステル系感光剤は濾過し、純水または希薄な酸水溶液或いはこれにメタノール等を加えた溶媒で洗浄、乾燥することにより目的とする１，２−ナフトキノン−２−ジアジドスルホン酸エステル系感光剤を得る事が出来る。しかしながら、酸中和剤のハロゲン化水素塩などの不純物を取り除くためには、洗浄を繰り返さなければならないので、好ましくは、反応中析出した酸中和剤のハロゲン化水素塩を濾過した後、純水等に注ぐ。更に好ましくは、反応後、反応液に酸を加え酸性にした後、酸中和剤のハロゲン化水素塩を濾過した後、純水に注ぐ。反応後に加える酸は、（１，２−ナフトキノン−２−ジアジドスルホニルハライドの使用モル＋アリールスルホニルハライド＋加える酸のモル）／（使用した酸中和剤のモル）が１．０１〜１．３となるような量が好ましい。１．０１未満では効果が薄く、１．３より多いと析出させた感光剤中に不純物が多くなり、洗浄が大変となる。酸としては、無機酸、有機酸いずれも使用できる。濾過後、通常は純水に注ぎ、再沈後濾過するが、純水を用いた場合は、濾過が困難になる場合があるので、希酸性水に注ぐのが好ましい。これにより濾過が容易になる。希酸性にする酸としては揮発性の酸、好ましくは、ハロゲン化水素酸、酢酸等が好ましい。希酸性水の酸濃度は０．０２規定〜０．５規定程度である。再沈に用いる純水或いは希酸性水の量は用いた溶媒に対して２〜１０重量倍、好ましくは、３〜６重量倍である。
【００３６】
再沈された感光剤は濾過し、純水または希薄な酸水溶液で洗浄した後、乾燥させることにより目的とする１，２−ナフトキノン−２−ジアジドスルホン酸エステル系感光剤を得ることができる。
【００３７】
或いは、例えば、特開平９−７７７３６号公報や特開２００２−２０７２９１号公報等に開示されているように、水と分液する性質を有する有機溶媒中で反応させて、反応後水洗して１，２−ナフトキノン−２−ジアジドスルホン酸エステル系感光剤を有機溶媒に溶解した形で得ることも出来る。
【００３８】
本発明の１，２−ナフトキノン−２−ジアジドスルホン酸エステル系感光剤及びアルカリ可溶性樹脂を含有させると好適なホトレジスト組成物とすることができる。
【００３９】
この本発明のホトレジスト組成物には、上記本発明の１，２−ナフトキノン−２−ジアジドスルホン酸エステル系感光剤は単独で用いても良く、２種以上を組み合わせても良い。
【００４０】
更に、所望に応じ本発明の目的を損なわない範囲で、他の１，２−ナフトキノン−２−ジアジドスルホン酸エステル系感光剤を併用することができる。
【００４１】
本発明において用いられるアルカリ可溶性樹脂としては、例えばノボラック樹脂、ポリビニルフェノールまたはその誘導体、スチレン−無水マレイン酸共重合体、ポリビニルヒドロキシベンゾエート、カルボキシル基含有メタアクリル酸系樹脂等を挙げることができる。
【００４２】
好ましい樹脂（Ａ）としては、ノボラック樹脂を挙げることができる。このようなノボラック樹脂は、モノ−、ジ−或いはトリ−アルキルフェノール類とモノアルデヒド化合物やビスアルデヒド化合物で示されるアルデヒド類とを重縮合することによって得られる。
【００４３】
上記フェノール類としては、例えばｏ−クレゾール、ｍ−クレゾール、ｐ−クレゾール、２，３−キシレノール、２，５−キシレノール、３，４−キシレノール、３，５−キシレノール、２，３，５−トリメチルフェノール、３，４，５−トリメチルフェノール等を挙げることができる。特にｏ−クレゾール、ｍ−クレゾール、ｐ−クレゾール、２，３−キシレノール、２，５−キシレノール、３，４−キシレノール、３，５−キシレノールおよび２，３，５−トリメチルフェノールが好ましい。これらのフェノール類は、単独でまたは２種以上組み合わせて用いられる。
【００４４】
また、上記フェノール類と重縮合させるアルデヒド類としては、例えばホルムアルデヒド、トリオキサン、パラホルムアルデヒド、ベンズアルデヒド、アセトアルデヒド、プロピルアルデヒド、フェニルアセトアルデヒド、α−フェニルプロピルアルデヒド、β−フェニルプロピルアルデヒド、ｏ−ヒドロキシベンズアルデヒド、ｍ−ヒドロキシベンズアルデヒド、ｐ−ヒドロキシベンズアルデヒド、ｏ−メチルベンズアルデヒド、ｍ−メチルベンズアルデヒド、ｐ−メチルベンズアルデヒド、ｐ−エチルベンズアルデヒド、ｐ−ｎ−ブチルベンズアルデヒド、フルフラール等を挙げることができる。これらのうち、ホルムアルデヒドを特に好適に用いることができる。
【００４５】
フェノール類とアルデヒド類との重縮合反応には、通常、酸性触媒が使用される。この酸性触媒としては、例えば塩酸、硝酸、硫酸、ギ酸、シュウ酸、酢酸、トルエンスルホン酸等を挙げることができる。
【００４６】
本発明において、１，２−ナフトキノン−２−ジアジドスルホン酸エステル系感光剤の配合量は、アルカリ可溶性樹脂１００重量部に対し該感光剤５〜１００重量部、好ましくは２０〜７０重量部である。この使用比率が５重量部未満では残膜率が著しく低下し、また１００重量部を越えると感度が低下する。
【００４７】
本発明の組成物には、必要に応じ、増感剤、界面活性剤等の各種配合剤を配合することができる。
【００４８】
さらに本発明の組成物には、レジストの放射線照射部の潜像を可視化させ、放射線照射時のハレーションの影響を少なくするために、染料や顔料を配合することができ、また接着性を改善するために、接着助剤を配合することもできる。さらに必要に応じて保存安定剤、消泡剤等も配合することができる。
【００４９】
本発明の組成物は、前述した１，２−ナフトキノン−２−ジアジドスルホン酸エステル系感光剤およびアルカリ可溶性樹脂並びに必要に応じて用いられる前述した各種配合剤を、例えば固形分濃度が２０〜４０重量％となるように溶剤に溶解し、孔径０．２μｍ程度のフィルターで濾過することによって調製される。
【００５０】
この際に用いられる溶剤としては、例えばエチ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エチルエーテル、エチレングリコールモノメチルエーテルアセテート、エチレングリコールモノエチルエーテルアセテート、ジエチレングリコールモノメチルエーテル、ジ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メチルエーテルアセテート、プロピレングリコールプロピルエーテルアセテート、トルエン、キシレン、メチルエチルケトン、シクロヘキサノン、２−ヒドロキシプロピオン酸エチル、２−ヒドロキシ−２−メチルプロピオン酸エチル、エトキシ酢酸エチル、ヒドロキシ酢酸エチル、２−ヒドロキシ−３−メチルブタン酸メチル、３−メトキシプロピオン酸メチル、３−エトキシプロピオン酸エチル、３−メトキシプロピオン酸エチル、３−メトキシ−２−メチルプロピオン酸メチル、酢酸エチル、酢酸ブチル、乳酸エチル等を挙げることができる。さらに、Ｎ−メチルホルムアミド、Ｎ，Ｎ−ジメチルホルムアミド、Ｎ−メチルホルムアニリド、Ｎ−メチルアセトアミド、Ｎ，Ｎ−ジメチルアセトアミド、Ｎ−メチルピロリドン、ジメチルスルホキシド、ベンジルエチルエーテル、ジヘキシルエーテル、アセトニルアセトン、イソホロン、カプロン酸、カプリル酸、１−オクタノール、１−ノナノール、ベンジルアルコール、酢酸ベンジル、安息香酸エチル、シュウ酸ジエチル、マレイン酸ジエチル、γ−ブチロラクトン、炭酸エチレン、炭酸プロピレン、フェニルセロソルブアセテート等の高沸点溶剤を添加することもできる。これらの溶剤は、単独でまたは２種以上を組み合わせて使用される。
【００５１】
本発明の組成物からレジストパターンを形成する際には、前述したようにして調製された組成物溶液を、回転塗布、流延塗布、ロール塗布等の適宜の塗布手段によって、例えばシリコンウエハー、アルミニウムで被覆されたウエハー、ガラス、プラスチック等の基板上に塗布することにより、レジスト被膜を形成し、場合により予め加熱処理（プレベーク）を行ったのち、所定のマスクパターンを介して露光する。その際に使用される光としては、例えば紫外線、特にｉ線（波長：３６５ｎｍ）が好適に用いられる。露光されたレジスト被膜をアルカリ現像液でアルカリ現像することにより、所定のレジストパターンを形成する。
【００５２】
【実施例】
次に実施例により本発明を更に詳細に説明する。
【００５３】
（多価フェノールの合成例１）Ｒ_１＝Ｒ_２＝Ｒ_３＝Ｒ_４＝Ｃ_２Ｈ_５の一般式（ＩＩ）を主体とする多価フェノールａの合成
攪拌機、温度計、滴下ロート、逆流冷却管および窒素導入管をつけた五つ口フラスコに、１３２．１３グラムのレゾルシノールと５８．０８グラムのプロピオンアルデヒドおよび１９０ｍｌのメタノールを入れ、窒素を通じながら、攪拌下に、５２．０９グラムの濃塩酸を約１５分間で滴下した。その後、加熱して還流させ、還流状態で３時間攪拌し、９５ｍｌの純水を滴下し、３０℃以下まで冷却し、更に２８５ｍｌの純水を加えた。冷却後、析出した結晶を濾別し、純水で洗浄後、真空乾燥し、１０５．１２グラムの結晶を得た。ＧＰＣで純度を測定したところ、目的とする環状多価フェノール（一般式（ＩＩ）：Ｒ_１＝Ｒ_２＝Ｒ_３＝Ｒ_４＝Ｃ_２Ｈ_５）の純度９５．８％、高分子量物質（目的物質より保持時間が短い成分）：３．６％、低分子量物質（目的物質より保持時間が長い成分）：０．６％であった。
【００５４】
（多価フェノールの合成例２）Ｒ_１＝Ｒ_２＝Ｒ_３＝Ｒ_４＝ｎ−Ｃ_４Ｈ_９の一般式（ＩＩ）を主体とする多価フェノールｂの合成
合成例１と同様な装置に、１３２．１３グラムのレゾルシノールと８６．１３グラムのｎ−バレルアルデヒドおよび２５０ｍｌのメタノールを入れ、窒素を通じながら、攪拌下に、５２．０９グラムの濃塩酸を約１５分間で滴下した。その後、加熱して還流させ、還流状態で３時間攪拌し、２００ｍｌの純水を滴下し、３０℃以下まで冷却し、更に２８５ｍｌの純水を加えた。冷却後、析出した結晶を濾別し、純水で洗浄後、真空乾燥し、１４２．５８グラムの結晶を得た。ＧＰＣで純度を測定したところ、目的とする環状多価フェノール（一般式（ＩＩ）：Ｒ_１＝Ｒ_２＝Ｒ_３＝Ｒ_４＝ｎ−Ｃ_４Ｈ_９）の純度９６．１％、高分子量物質（目的物質より保持時間が短い物質）：２．９％、低分子量物質（目的物質より保持時間が長い物質）：１．０％であった。
【００５５】
（実施例１）感光剤Ａの合成例
多価フェノールａ１２．０１グラム（０．０２モル）、１，２−ナフトキノンジアジド−５−スルホニルクロリド１３．４３グラム（０．０５モル）、ｐ−トルエンスルホニルクロリド５．７２グラム（０．０３モル）及びアセトン１５０グラムを３つ口フラスコに仕込み均一に溶解した。次いでトリエチルアミン／アセトン＝８．９０グラム／８．９０グラムの混合物を３０〜３５℃、６０分間で滴下した。同温度で４０分間攪拌後、濃塩酸１．７グラムを加えて中和した。析出したトリエチルアミン塩酸塩を濾別し、この反応混合物を純水７１０グラムに注ぎ、生じた沈殿物を濾別、水洗、乾燥して、１，２−ナフトキノン−２−ジアジドスルホン酸エステル系感光剤Ａ２５．０グラムを得た。
【００５６】
（実施例２〜７）感光剤Ｂ〜Ｇの合成例
実施例１と全く同様にして、下記表１の１，２−ナフトキノン−２−ジアジドスルホン酸エステル系感光剤Ｂ〜Ｇを合成した。
【００５７】
【表１】

【００５８】
（比較例１）感光剤Ｈの合成例
多価フェノールａ１２．０１グラム（０．０２モル）、１，２−ナフトキノンジアジド−５−スルホニルクロリド２６．８７グラム（０．１０モル）、γ―ブチロラクトン４０グラム及びアセトン１５０グラムを３つ口フラスコに仕込み均一に溶解した。次いでトリエチルアミン／アセトン＝１１．４グラム／１１．４グラムの混合物を３０〜３５℃、６０分間で滴下した。同温度で４０分間攪拌後、濃塩酸２．１グラムを加えて中和した。析出したトリエチルアミン塩酸塩を濾別し、この反応混合物を純水７２０グラムに注ぎ、生じた沈殿物を濾別、水洗、乾燥して、１，２−ナフトキノン−２−ジアジドスルホン酸エステル系感光剤Ｈ３５．３グラムを得た。
【００５９】
（比較例２）感光剤Ｉの合成例
多価フェノールａ１モルに対して、１，２−ナフトキノン−２−ジアジドスルホニルクロリド３モルを用いた以外は比較例１と同様にして、１，２−ナフトキノン−２−ジアジドスルホン酸エステル系感光剤Ｉを得た。
【００６０】
（ノボラック樹脂の合成）
ｍ−クレゾール４５ｇ、ｐ−クレゾール３３ｇ、２，５−キシレノール２６ｇ、３７％ホルマリン水溶液５３ｇ及びシュウ酸０．１５ｇを３つ口フラスコに仕込み、攪拌しながら１００℃まで昇温し１４時間反応させた。その後温度を２００℃まで上げ、徐々に減圧して、水、未反応のモノマー、ホルムアルデヒド、シュウ酸等を留去した。次いでこのノボラック樹脂をメタノール／水から分別して、得られたノボラック樹脂を加熱し、減圧下で２４時間乾燥させてアルカリ可溶性ノボラック樹脂を得た。得られたノボラック樹脂は、重量平均分子量７８００（ポリスチレン換算）であった。
【００６１】
（実施例８〜１５及び比較例３，４）上記感光剤を使用したホトレジスト組成物の調製
表２に示す重量部の感光剤Ａ〜Ｉを、合成例で得たノボラック樹脂１００重量部に対して配合し、これを乳酸エチル５００重量部に溶解し、更に、界面活性剤としてフロラードＦＣ−４３０（３Ｍ社製）０．３５重量部を加え、０．２μｍのメンブレンフィルターで濾過し、実施例８〜１５及び比較例３，４のレジスト溶液とした。
【００６２】
上記レジスト溶液をヘキサメチルジシラザンで処理したシリコンウエハーにスピンコートで乾燥膜厚が１．０５μｍになるように塗布し、ホットプレートで１１０℃、９０秒乾燥した。このレジスト膜にｉ線露光し、２．３８％水酸化テトラメチルアンモニウム水溶液で現像し（温度：２３℃、時間：６０秒）、感度曲線を作成し、感度、残膜率を求めた。結果を表２に示す。
【００６３】
【表２】

【００６４】
表２の結果から、本発明の感光剤を使用したレジスト組成物は比較例と比較して高感度で残膜率も高いことが分かった。また、アリールスルホニルクロリドの使用量が少ない感光剤Ｆを用いた実施例１４では感度向上の効果が十分ではなかった。
【００６５】
【発明の効果】
以上説明したように、本発明によると、先に出願した１，２−ナフトキノン−２−ジアジドスルホン酸エステル系感光剤に関して、多価フェノールである環状ポリヒドロキシ化合物のヒドロキシ基の一部を１，２−ナフトキノン−２−ジアジドスルホニル基とすると同時に一部をアリールスルホニル基とすることにより、感度がさらに向上すると共に残膜率が良好になり、半導体集積回路や液晶ディスプレイ、ＥＬディスプレイ等の製造用ホトレジストの感光剤として有用で、感度及び残膜率が著しく向上した１，２−ナフトキノン−２−ジアジドスルホン酸エステル系感光剤及びホトレジスト組成物を提供することができる。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a 1,2-naphthoquinone-2-diazidosulfonic acid ester-based photosensitizer and a photoresist composition, and more specifically, a solvent useful as a photosensitizer for a photoresist used in the production of semiconductor integrated circuits, liquid crystal displays, and the like. A 1,2-naphthoquinone-2-diazidesulfonic acid ester-based photosensitizer and a photoresist composition having good solubility in water and excellent sensitivity and residual film ratio.
[0002]
[Prior art]
A 1,2-naphthoquinone-2-diazidosulfonic acid ester-based photosensitive agent is generally used as a photosensitive component of a positive photoresist in combination with an alkali-soluble resin binder such as a novolak resin. Since these positive photoresists have high resolution, they are used for manufacturing semiconductor integrated circuits, liquid crystal displays, EL displays, and the like.
[0003]
Such a 1,2-naphthoquinone-2-diazidosulfonic acid ester-based photosensitizer as a photosensitive component of a positive type photoresist usually comprises a polyhydric phenol compound and 1,2-naphthoquinone-2-diazidosulfonyl chloride in an acid. It is produced by reacting in the presence of a wetting agent. Examples of the polyhydric phenol compound used herein include polyhydroxybenzophenones (for example, see Non-patent Document 1 and Patent Document 1), polyhydroxytriphenylmethanes (for example, see Patent Document 2), and phenols 3, 4 Alternatively, polyhydric phenol compounds in which five molecules are bonded with methylene (for example, see Patent Documents 3, 4, and 5) are known. Polyhydroxybenzophenone, especially 1,2-naphthoquinone-2-diazidosulfonic acid ester from trihydroxybenzophenone and tetrahydroxybenzophenone, can be manufactured at low cost, and is used as a photosensitive component in photoresists for manufacturing semiconductor integrated circuits and liquid crystal displays. Have been.
[0004]
Here, polyhydroxybenzophenone has absorption at the i-line (365 nm), and a resist using the same is used for exposure to the g-line (436 nm) because the pattern shape becomes poor in the i-line exposure. For i-line exposure, a resist using a polyhydric phenol compound in which 3, 4, or 5 molecules of polyhydroxytriphenylmethanes or phenols are bonded by methylene is used. However, the production of these polyhydric phenol compounds is complicated, and 1,2-naphthoquinone-2-diazidosulfonic acid ester of these polyhydric phenols is not sufficiently soluble in a resist solvent. The photoresist composition used has problems such as insufficient dissolution of the photosensitizer, deposition of foreign substances over time, and low sensitivity.
[0005]
Further, a 1,2-naphthoquinone-2-diazidosulfonic acid ester using a cyclic polyhydroxy compound as a polyphenol compound which does not absorb the i-line and can be easily produced is disclosed (for example, see Patent Document 6). ). However, 1,2-naphthoquinone-2-diazidosulfonic acid ester using a cyclic polyhydroxy compound also has insufficient solubility in a solvent, and a photoresist composition using the same does not sufficiently dissolve a photosensitive agent, Foreign substances are deposited over time. Alternatively, there is a problem that the sensitivity is slow. When the sensitivity is increased, the remaining film ratio decreases, and there is a problem that the sensitivity and the remaining film ratio are not compatible.
[0006]
[Patent Document 1] JP-A-62-153950 (lower right column of page 2 to upper right column of page 4)
[Patent Document 2] JP-A-1-189644 (page 5, upper right column to page 6, upper left column, etc.)
[Patent Document 3] Japanese Patent Publication No. 4-502519 (Page 5 etc.)
[Patent Document 4] JP-A-6-167805 (Pages 5 to 9 etc.)
[Patent Document 5] JP-A-7-120917 (page 7 etc.)
[Patent Document 6] JP-A-3-279957 (claims, etc.)
[Patent Document 7] Japanese Patent Application No. 2002-381849 (claims, etc.)
[Patent Document 8] Japanese Patent Application No. 2002-381850 (claims, etc.)
[Non-Patent Document 1] S. Deforest, "Photoresist", McGrow-Hill Book Company, 1975, p. 48-55.
[0007]
[Problems to be solved by the invention]
Many polyhydric phenol compounds and 1,2-naphthoquinone-2-diazidosulfonic acid ester-based photosensitizers as described above have been disclosed. However, polyhydric phenols which do not absorb i-ray and can be easily produced are used. There is no known 1,2-naphthoquinone-2-diazidesulfonic acid ester-based photosensitizer having good solubility in the resist solvent used. Further, there is no known photoresist composition having both sensitivity and residual film ratio.
[0008]
Recently, large-screen liquid crystal displays, development of liquid crystal displays with built-in drive circuits using low-temperature polycrystalline Si-TFTs on glass substrates, and system-on-panels with built-in CPU, memory, etc. on glass substrates Are being developed, and resists are required to have high sensitivity by i-line exposure, a high residual film ratio, and low cost.
[0009]
Therefore, the present inventors have found that 1,2-naphthoquinone-2-diazidesulfonic acid ester-based photosensitization using a cyclic polyhydroxy compound disclosed in Patent Document 6 which is a polyhydric phenol which does not absorb i-ray and is easy to produce. As a result of a detailed study of the agent, a polyhydric phenol obtained by condensation of resorcinol and at least one aldehyde selected from aldehydes having 3 to 10 carbon atoms and having a high molecular weight component of a certain amount or less is obtained. The specific 1,2-naphthoquinone-2-diazidosulfonic acid ester-based photosensitizer obtained from the above has good solubility in a resist solvent or the like, and a photoresist composition using the same as a photosensitizer can be sufficiently satisfied. It was found that it had high sensitivity and excellent storage stability and was extremely high in practicality, and was filed earlier (Patent Document 7, ). However, there still remains a problem that a sufficiently high sensitivity cannot be obtained in order to obtain a high residual film ratio.
[0010]
The present invention relates to an invention that improves the invention previously filed, and has good solubility, can be manufactured at a low cost, and has a balance between sensitivity and residual film ratio, such as a semiconductor integrated circuit, a liquid crystal display, and an EL display. In particular, an object of the present invention is to provide a 1,2-naphthoquinone-2-diazidesulfonic acid ester-based photosensitizer and a photoresist composition useful as a photosensitizer for a photoresist for producing a liquid crystal display.
[0011]
[Means for Solving the Problems]
As described above, as a result of further study on the 1,2-naphthoquinone-2-diazidosulfonic acid ester-based photosensitizer previously filed, a part of the hydroxy group of the cyclic polyhydroxy compound which is a polyhydric phenol was changed to 1,1. The inventors have found that the sensitivity is further improved and the residual film ratio is improved by using a 2-naphthoquinone-2-diazidosulfonyl group and a part thereof as an arylsulfonyl group, thereby completing the present invention. .
[0012]
A first aspect of the present invention is a 1,2-naphthoquinone-2-diazidesulfonic acid ester-based photosensitizer represented by the following general formula (I).
[0013]
Embedded image

[0014]
However, in the general formula (I), R ₁ , R ₂ , R ₃ And R ₄ Each independently represents an alkyl group having 2 to 9 carbon atoms; ₁ ~ D ₈ Are independent of each other, at least two are 1,2-naphthoquinone-2-diazidosulfonyl groups, the remaining at least one is an arylsulfonyl group, and the others represent hydrogen atoms.
[0015]
According to a second aspect of the present invention, there is provided a photoresist composition comprising the 1,2-naphthoquinone-2-diazidesulfonic acid ester-based photosensitizer of the first aspect and an alkali-soluble resin.
[0016]
The 1,2-naphthoquinone-2-diazidosulfonic acid ester-based photosensitizer represented by the general formula (I) of the present invention can be easily produced, is inexpensive, can be mass-produced, and is aryl. The sensitivity is further improved as compared with those having no sulfonyl group. In addition, the photoresist composition of the present invention containing this photosensitizer is useful for fine processing in the production of liquid crystal displays, has a sufficiently satisfactory sensitivity, and has no arylsulfonyl group. It has further improved sensitivity and residual film ratio, and has excellent storage stability and extremely high practicality, and is particularly useful for i-line exposure.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in more detail.
[0018]
The 1,2-naphthoquinone-2-diazidesulfonic acid ester-based photosensitizer of the present invention has the following general formula (I) obtained by a condensation reaction of resorcinol with at least one aldehyde selected from aldehydes having 3 to 10 carbon atoms. It can be produced by reacting a polyhydric phenol mainly composed of the compound represented by II) with 1,2-naphthoquinone-2-diazidosulfonyl halide and arylsulfonyl halide in the presence of an acid neutralizing agent. Here, in the present invention, the polyhydric phenol is a mixture containing a compound represented by the general formula (II) (which may include an isomer) and another compound. In the present invention, it is preferable to use a polyhydric phenol in which the content of a component having a shorter retention time than the compound represented by the general formula (II) in GPC measurement is 10% or less. This is because the use of a compound having a high molecular weight component lowers the solubility of the produced photosensitive agent.
[0019]
Here, when producing the 1,2-naphthoquinone-2-diazidosulfonic acid ester-based photosensitizer of the present invention, 1,2-naphthoquinone-2-diazidosulfonyl halide and arylsulfonyl halide are simultaneously reacted. However, it goes without saying that the reaction may be performed in two stages.
[0020]
When reacting 1,2-naphthoquinone-2-diazidosulfonyl halide and arylsulfonyl halide, the molar ratio of the two is 3: 1 to 1: 1, that is, the arylsulfonyl halide has a molar ratio of 1/4. It is preferably １ ／.
[0021]
Embedded image

[0022]
However, R in the general formula (II) ₁ , R ₂ , R ₃ And R ₄ Each independently represents an alkyl group having 2 to 9 carbon atoms.
[0023]
The compound represented by the general formula (II) is a compound obtained by cyclically condensing 4 mol of resorcinol and 4 mol of aldehyde. The method for synthesizing this compound is described in A.S. G. FIG. Severker Hoberg (J. Org. Chem., Vol. 45, 4498 (1980)) and Y. It can be easily synthesized as described in detail by Aoyama et al. (J. Am. Chem. Soc., Vol. 111, 5397 (1989)). However, after the reaction of resorcinol and aldehyde, a phenol derivative is further added. It involves a process of making and refining and then returning to a phenol compound, and is very complicated and impractical.
[0024]
Preferred synthesis examples are shown below.
[0025]
The resorcinol and the aldehyde are reacted in water or an alcohol solvent such as methanol or ethanol, preferably an alcohol solvent, particularly preferably a methanol solvent, using an acid catalyst, preferably a hydrochloric acid catalyst. The molar ratio of resorcinol to aldehyde is usually preferably 1: 0.6 to 1.5. After the reaction, crystals are slowly precipitated. For example, when methanol is used as a reaction solvent, water is added after the reaction to precipitate crystals, but after adding water, the crystals are heated and then slowly cooled again to grow crystals slowly so as not to form a high molecular weight component. When water is further added to precipitate crystals, the resulting crystals are easily converted into polyhydric phenol having a high molecular weight component (a component having a shorter retention time than the compound represented by the general formula (II)) of 10% or less by GPC. Is obtained. In addition, recrystallization can be performed if necessary.
[0026]
The polyhydric phenol mainly composed of the compound represented by the general formula (II) has a component (high molecular weight component) having a shorter retention time than the compound represented by the general formula (II) by 10% or less as measured by GPC (gel permeation chromatography). It is preferable that the polyhydric phenol mainly composed of the compound represented by the general formula (I) has a purity of 90% or more. When the purity is less than 90%, the obtained 1,2-naphthoquinone-2-diazidesulfonic acid ester-based photosensitizer has low solubility in an organic solvent, does not dissolve in the solvent, or precipitates with time even if dissolved. It cannot be used as a photosensitive agent for a photoresist combined with an alkali-soluble resin such as novolak. If the purity of the crystals precipitated after the reaction is less than 90%, the purity can be increased to 90% or more by means such as recrystallization.
[0027]
Here, the measurement conditions of GPC are as follows.
Column: Shodex GPC KF-802 x 1 + KF-801 x 3
Column temperature: 40 ° C
Detection wavelength: 254 nm
Moving bed: THF
Flow rate of moving bed: 1.0 ml / min.
[0028]
Polyhydric phenols mainly composed of the compound represented by the general formula (II) hardly absorb at i-line (365 nm), and are particularly suitable as a raw material polyhydric phenol of a photosensitive agent for a photoresist for i-line exposure.
[0029]
The 1,2-naphthoquinone-2-diazidosulfonyl halide used herein includes 1,2-naphthoquinone-2-diazide-4-sulfonyl chloride, 1,2-naphthoquinone-2-diazide-5-sulfonyl chloride and At least one selected from 1,2-naphthoquinone-2-diazide-6-sulfonyl chloride, but 1,2-naphthoquinone-2-diazide-5-sulfonyl chloride is advantageously used in terms of cost.
[0030]
Examples of the arylsulfonyl halide include benzenesulfonyl chloride, benzenesulfonyl bromide, toluenesulfonyl chloride, toluenesulfonyl bromide, and mesitylenesulfonyl chloride.
[0031]
The reaction of a polyhydric phenol mainly composed of the compound represented by the general formula (II) with 1,2-naphthoquinone-2-diazidosulfonyl halide and arylsulfonyl halide is generally carried out by, for example, acetone, methyl ethyl ketone, dioxane, The reaction is performed in at least one organic solvent selected from tetrahydrofuran, 1,3-dioxolane, γ-butyrolactone, propylene carbonate, N-methylpyrrolidone and the like in the presence of an acid neutralizing agent. Such acid neutralizing agents are preferably organic amines such as ethylamine, diethylamine, triethylamine, diisopropylamine, tripropylamine, triisobutylamine, triethanolamine, monomethyldicyclohexylamine, N-methylpiperidine, N-methylmorpholine, -Methylpyrrolidine, 1,4-dimethylpiperazine, pyridine, N, N-dimethylaniline, N, N-dimethylaminopyridine and the like.
[0032]
The reaction is usually carried out by dissolving (1) polyhydric phenol, 1,2-naphthoquinone-2-diazidosulfonyl halide and arylsulfonyl halide in an organic solvent, and then adding an organic amine or a solution in which the organic amine is dissolved in the solvent. Alternatively, (2) a polyhydric phenol and 1,2-naphthoquinone-2-diazidosulfonyl halide are dissolved in an organic solvent, and an organic amine corresponding to the used halide or a solution obtained by dissolving the organic amine in the solvent is added thereto. The arylsulfonyl halide is then added, followed by the corresponding organic amine. Here, the order of the added halides may be reversed. Alternatively, (3) a polyhydric phenol and an organic amine are dissolved in a solvent, and 1,2-naphthoquinone-2-diazidosulfonyl halide and arylsulfonyl halide, or those obtained by dissolving these halides in a solvent are successively added. Or at the same time, followed by stirring for about 10 minutes to 5 hours to cause a condensation reaction. The addition and the subsequent condensation reaction are carried out at a temperature of -10C to 50C, preferably 10C to 40C, for about 10 minutes to 3 hours.
[0033]
The amount of 1,2-naphthoquinone-2-diazidosulfonyl halide used relative to the polyhydric phenol is preferably 2 to 6 mol, more preferably 2.5 to 4 mol, per mol of the polyhydric phenol. If the amount is less than 2 mol, the residual film ratio of the photoresist combined with the alkali-soluble resin is low, and if it is more than 6 mol, the sensitivity becomes low, which is not preferable. The arylsulfonyl halide may be used in a necessary amount based on the 1,2-naphthoquinone-2-diazidosulfonyl halide to be used, and preferably, 1,2-naphthoquinone-2-diazidosulfonyl halide and arylsulfonyl halide are used. Preferably, the molar ratio is between 3: 1 and 1: 1.
[0034]
The amount of the acid neutralizer used is usually 1.0 to 1.5 mol, preferably 1.0 mol to 1 mol of (1,2-naphthoquinone-2-diazidosulfonyl-diazidosulfonyl halide + arylsulfonyl halide). Is 1.05 to 1.2 mol. If the amount is less than 1.0 mol, 1,2-naphthoquinone-2-diazidosulfonyl-diazidosulfonyl halide and / or aryl halide tends to remain, and if it is more than 1.5 mol, 1,2-quinonediazide due to excess acid neutralizing agent. The group is easily decomposed. The amount of the solvent used is 2 to 10 times by weight, preferably 3 to 5 times by weight of (1,2-naphthoquinone-2-diazidosulfonyl halide + arylsulfonyl halide + polyhydric phenol compound). If the amount is less than 2 times by weight, the reaction components do not dissolve or the storage stability, which is the object of the present invention, becomes poor. If the amount is more than 10 times by weight, a large amount of water for reprecipitation must be used. Will not be economical.
[0035]
The reaction mixture is poured into a poor solvent for the resulting photosensitizer, such as pure water or methanol, to precipitate a 1,2-naphthoquinone-2-diazidosulfonic acid ester-based photosensitizer. The precipitated 1,2-naphthoquinone-2-diazidosulfonic acid ester-based photosensitizer is filtered, washed with pure water or a dilute acid aqueous solution or a solvent obtained by adding methanol or the like thereto, and dried to obtain the target 1,1,2. A 2-naphthoquinone-2-diazidesulfonic acid ester-based photosensitizer can be obtained. However, in order to remove impurities such as a hydrogen halide salt of the acid neutralizing agent, washing must be repeated. Therefore, it is preferable that the hydrogen halide salt of the acid neutralizing agent precipitated during the reaction is filtered and then purified. Pour into water etc. More preferably, after the reaction, an acid is added to the reaction solution to make it acidic, and then a hydrogen halide salt of an acid neutralizing agent is filtered and then poured into pure water. The acid added after the reaction is (mol of 1,2-naphthoquinone-2-diazidosulfonyl halide + mol of arylsulfonyl halide + mol of acid to be added) / (mol of acid neutralizer used) of 1.01 to 1. An amount such as to be 3 is preferred. If it is less than 1.01, the effect is small, and if it is more than 1.3, impurities are increased in the deposited photosensitive agent, and cleaning becomes difficult. As the acid, either an inorganic acid or an organic acid can be used. After the filtration, the mixture is usually poured into pure water and filtered after reprecipitation. However, when pure water is used, it may be difficult to perform filtration. This facilitates filtration. The acid to be made dilute is preferably a volatile acid, preferably a hydrohalic acid, acetic acid or the like. The acid concentration of the dilute acidic water is about 0.02 to 0.5 normal. The amount of pure water or dilute acid water used for reprecipitation is 2 to 10 times by weight, preferably 3 to 6 times by weight of the solvent used.
[0036]
The reprecipitated photosensitizer is filtered, washed with pure water or a dilute aqueous acid solution, and then dried to obtain the desired 1,2-naphthoquinone-2-diazidesulfonic acid ester photosensitizer. .
[0037]
Alternatively, for example, as disclosed in JP-A-9-77736 and JP-A-2002-207291, the reaction is carried out in an organic solvent having a property of separating from water, and after the reaction, water washing is performed. , 2-Naphthoquinone-2-diazidesulfonic acid ester-based photosensitizers can be obtained by dissolving them in an organic solvent.
[0038]
When the 1,2-naphthoquinone-2-diazidosulfonic acid ester-based photosensitizer of the present invention and an alkali-soluble resin are contained, a suitable photoresist composition can be obtained.
[0039]
In the photoresist composition of the present invention, the 1,2-naphthoquinone-2-diazidesulfonic acid ester-based photosensitizer of the present invention may be used alone or in combination of two or more.
[0040]
Further, if desired, other 1,2-naphthoquinone-2-diazidosulfonic acid ester-based photosensitizers can be used in a range not to impair the object of the present invention.
[0041]
Examples of the alkali-soluble resin used in the present invention include a novolak resin, polyvinylphenol or a derivative thereof, a styrene-maleic anhydride copolymer, polyvinylhydroxybenzoate, and a carboxyl group-containing methacrylic acid-based resin.
[0042]
Preferred resins (A) include novolak resins. Such a novolak resin is obtained by polycondensing a mono-, di- or tri-alkylphenol with an aldehyde represented by a monoaldehyde compound or a bisaldehyde compound.
[0043]
Examples of the phenols include o-cresol, m-cresol, p-cresol, 2,3-xylenol, 2,5-xylenol, 3,4-xylenol, 3,5-xylenol, 2,3,5-trimethyl Phenol, 3,4,5-trimethylphenol and the like can be mentioned. Particularly preferred are o-cresol, m-cresol, p-cresol, 2,3-xylenol, 2,5-xylenol, 3,4-xylenol, 3,5-xylenol and 2,3,5-trimethylphenol. These phenols are used alone or in combination of two or more.
[0044]
Examples of the aldehyde to be polycondensed with the phenols include formaldehyde, trioxane, paraformaldehyde, benzaldehyde, acetaldehyde, propylaldehyde, phenylacetaldehyde, α-phenylpropylaldehyde, β-phenylpropylaldehyde, o-hydroxybenzaldehyde, -Hydroxybenzaldehyde, p-hydroxybenzaldehyde, o-methylbenzaldehyde, m-methylbenzaldehyde, p-methylbenzaldehyde, p-ethylbenzaldehyde, pn-butylbenzaldehyde, furfural and the like. Of these, formaldehyde can be particularly preferably used.
[0045]
An acidic catalyst is usually used for the polycondensation reaction between phenols and aldehydes. Examples of the acidic catalyst include hydrochloric acid, nitric acid, sulfuric acid, formic acid, oxalic acid, acetic acid, and toluenesulfonic acid.
[0046]
In the present invention, the compounding amount of the 1,2-naphthoquinone-2-diazidesulfonic acid ester-based photosensitizer is 5 to 100 parts by weight, preferably 20 to 70 parts by weight, based on 100 parts by weight of the alkali-soluble resin. is there. If the use ratio is less than 5 parts by weight, the residual film ratio is remarkably reduced, and if it exceeds 100 parts by weight, the sensitivity is reduced.
[0047]
Various additives such as a sensitizer and a surfactant can be added to the composition of the present invention, if necessary.
[0048]
Furthermore, in the composition of the present invention, a dye or a pigment can be blended in order to visualize the latent image of the radiation-irradiated portion of the resist and to reduce the influence of halation upon irradiation, and improve the adhesiveness. For this purpose, an adhesion aid can be blended. Further, if necessary, a storage stabilizer, an antifoaming agent and the like can be added.
[0049]
The composition of the present invention comprises the aforementioned 1,2-naphthoquinone-2-diazidesulfonic acid ester-based photosensitizer and alkali-soluble resin and the above-mentioned various compounding agents used as needed, for example, having a solid content of 20 to It is prepared by dissolving in a solvent so as to have a concentration of 40% by weight and filtering through a filter having a pore size of about 0.2 μm.
[0050]
As the solvent used at this time, for example, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol methyl ether acetate, propylene Glycol propyl ether acetate, toluene, xylene, methyl ethyl ketone, cyclohexanone, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutanoate, -Methyl methoxypropionate, ethyl 3-ethoxypropionate , 3-methoxypropionate, ethyl 3-methoxy-2-methylpropionic acid methyl, ethyl acetate, butyl acetate, and ethyl lactate. Furthermore, N-methylformamide, N, N-dimethylformamide, N-methylformanilide, N-methylacetamide, N, N-dimethylacetamide, N-methylpyrrolidone, dimethylsulfoxide, benzylethyl ether, dihexyl ether, acetonylacetone , Isophorone, caproic acid, caprylic acid, 1-octanol, 1-nonanol, benzyl alcohol, benzyl acetate, ethyl benzoate, diethyl oxalate, diethyl maleate, γ-butyrolactone, ethylene carbonate, propylene carbonate, phenyl cellosolve acetate, etc. High boiling solvents can also be added. These solvents are used alone or in combination of two or more.
[0051]
When forming a resist pattern from the composition of the present invention, the composition solution prepared as described above, by a suitable coating means such as spin coating, casting coating, roll coating, for example, silicon wafer, aluminum A resist film is formed by coating on a substrate such as a wafer, glass, plastic, or the like, which has been coated with, and if necessary, heat treatment (pre-bake) is performed, and then exposure is performed through a predetermined mask pattern. As the light used at that time, for example, ultraviolet light, particularly i-ray (wavelength: 365 nm) is suitably used. A predetermined resist pattern is formed by subjecting the exposed resist film to alkali development with an alkali developer.
[0052]
【Example】
Next, the present invention will be described in more detail with reference to examples.
[0053]
(Synthesis example 1 of polyhydric phenol) R ₁ = R ₂ = R ₃ = R ₄ = C ₂ H ₅ Of polyhydric phenol a based on the general formula (II)
132.13 g of resorcinol, 58.08 g of propionaldehyde and 190 ml of methanol were put into a five-necked flask equipped with a stirrer, a thermometer, a dropping funnel, a reflux condenser and a nitrogen inlet tube, and stirred while passing nitrogen. Below, 52.09 grams of concentrated hydrochloric acid were added dropwise over about 15 minutes. Thereafter, the mixture was heated to reflux, stirred under reflux for 3 hours, 95 ml of pure water was added dropwise, cooled to 30 ° C. or lower, and 285 ml of pure water was further added. After cooling, the precipitated crystals were separated by filtration, washed with pure water, and dried under vacuum to obtain 105.12 g of crystals. When the purity was measured by GPC, the target cyclic polyphenol (general formula (II): R ₁ = R ₂ = R ₃ = R ₄ = C ₂ H ₅ ), A high molecular weight substance (a component having a shorter retention time than the target substance): 3.6%, and a low molecular weight substance (a component having a longer retention time than the target substance): 0.6%.
[0054]
(Synthesis example 2 of polyhydric phenol) R ₁ = R ₂ = R ₃ = R ₄ = N-C ₄ H ₉ Of polyhydric phenol b based on general formula (II)
In a device similar to that of Synthesis Example 1, 132.13 g of resorcinol, 86.13 g of n-valeraldehyde and 250 ml of methanol were placed, and 52.09 g of concentrated hydrochloric acid was added to about 15 In minutes. Thereafter, the mixture was heated to reflux, stirred for 3 hours in a reflux state, 200 ml of pure water was added dropwise, cooled to 30 ° C. or lower, and 285 ml of pure water was further added. After cooling, the precipitated crystals were separated by filtration, washed with pure water, and dried under vacuum to obtain 142.58 g of crystals. When the purity was measured by GPC, the target cyclic polyphenol (general formula (II): R ₁ = R ₂ = R ₃ = R ₄ = N-C ₄ H ₉ ), The high molecular weight substance (substance having a shorter retention time than the target substance): 2.9%, and the low molecular weight substance (substance having a longer retention time than the target substance): 1.0%.
[0055]
(Example 1) Synthesis example of photosensitive agent A
12.01 g (0.02 mol) of polyhydric phenol a, 13.43 g (0.05 mol) of 1,2-naphthoquinonediazide-5-sulfonyl chloride, 5.72 g (0.03 mol) of p-toluenesulfonyl chloride ) And 150 g of acetone were charged into a three-necked flask and uniformly dissolved. Then, a mixture of triethylamine / acetone = 8.90 g / 8.90 g was dropped at 30 to 35 ° C. for 60 minutes. After stirring at the same temperature for 40 minutes, the mixture was neutralized by adding 1.7 g of concentrated hydrochloric acid. The precipitated triethylamine hydrochloride was separated by filtration, the reaction mixture was poured into 710 g of pure water, and the resulting precipitate was separated by filtration, washed with water and dried to obtain 1,2-naphthoquinone-2-diazidesulfonic acid ester-based photosensitive material. 25.0 grams of Agent A were obtained.
[0056]
(Examples 2 to 7) Synthesis Examples of Photosensitive Agents BG
In the same manner as in Example 1, 1,2-naphthoquinone-2-diazidosulfonic acid ester-based photosensitizers B to G shown in Table 1 below were synthesized.
[0057]
[Table 1]

[0058]
Comparative Example 1 Synthesis Example of Photosensitive Agent H
A three-neck flask containing 12.01 g (0.02 mol) of polyhydric phenol a, 26.87 g (0.10 mol) of 1,2-naphthoquinonediazide-5-sulfonyl chloride, 40 g of γ-butyrolactone and 150 g of acetone And uniformly dissolved. Then, a mixture of triethylamine / acetone = 11.4 g / 11.4 g was added dropwise at 30 to 35 ° C. for 60 minutes. After stirring at the same temperature for 40 minutes, 2.1 g of concentrated hydrochloric acid was added for neutralization. The precipitated triethylamine hydrochloride was separated by filtration, the reaction mixture was poured into 720 g of pure water, and the resulting precipitate was separated by filtration, washed with water and dried to obtain 1,2-naphthoquinone-2-diazidesulfonic acid ester-based photosensitive material. 35.3 grams of Agent H were obtained.
[0059]
Comparative Example 2 Synthesis Example of Photosensitive Agent I
1,2-Naphthoquinone-2-diazide sulfonic acid ester was prepared in the same manner as in Comparative Example 1 except that 3 mol of 1,2-naphthoquinone-2-diazidosulfonyl chloride was used for 1 mol of polyhydric phenol. Photosensitive agent I was obtained.
[0060]
(Synthesis of novolak resin)
45 g of m-cresol, 33 g of p-cresol, 26 g of 2,5-xylenol, 53 g of a 37% aqueous formalin solution and 0.15 g of oxalic acid were charged into a three-necked flask, heated to 100 ° C. with stirring, and reacted for 14 hours. . Thereafter, the temperature was raised to 200 ° C., and the pressure was gradually reduced to distill off water, unreacted monomers, formaldehyde, oxalic acid and the like. Next, the novolak resin was separated from methanol / water, and the obtained novolak resin was heated and dried under reduced pressure for 24 hours to obtain an alkali-soluble novolak resin. The obtained novolak resin had a weight average molecular weight of 7,800 (in terms of polystyrene).
[0061]
(Examples 8 to 15 and Comparative Examples 3 and 4) Preparation of photoresist composition using the above photosensitive agent
The photosensitive agents A to I in parts by weight shown in Table 2 were mixed with 100 parts by weight of the novolak resin obtained in the synthesis example, and this was dissolved in 500 parts by weight of ethyl lactate. 430 (manufactured by 3M) was added, and the solution was filtered through a 0.2 μm membrane filter to obtain resist solutions of Examples 8 to 15 and Comparative Examples 3 and 4.
[0062]
The resist solution was applied to a silicon wafer treated with hexamethyldisilazane by spin coating so that a dry film thickness became 1.05 μm, and dried on a hot plate at 110 ° C. for 90 seconds. The resist film was exposed to i-rays and developed with a 2.38% aqueous solution of tetramethylammonium hydroxide (temperature: 23 ° C., time: 60 seconds) to create a sensitivity curve, and the sensitivity and residual film ratio were determined. Table 2 shows the results.
[0063]
[Table 2]

[0064]
From the results in Table 2, it was found that the resist composition using the photosensitive agent of the present invention had higher sensitivity and a higher residual film ratio than the comparative example. Further, in Example 14 using the photosensitive agent F in which the amount of the arylsulfonyl chloride used was small, the effect of improving the sensitivity was not sufficient.
[0065]
【The invention's effect】
As described above, according to the present invention, in the 1,2-naphthoquinone-2-diazidesulfonic acid ester-based photosensitizer previously applied, a part of the hydroxy group of the cyclic polyhydroxy compound as a polyhydric phenol is changed to 1 , 2-naphthoquinone-2-diazidosulfonyl group and partly an arylsulfonyl group to further improve the sensitivity and the residual film ratio, thereby improving the performance of the semiconductor integrated circuit, liquid crystal display, EL display, etc. A 1,2-naphthoquinone-2-diazidosulfonic acid ester-based photosensitive agent which is useful as a photosensitive agent for a photoresist for production and has remarkably improved sensitivity and residual film ratio, and a photoresist composition can be provided.

Claims (2)

A 1,2-naphthoquinone-2-diazidesulfonic acid ester-based photosensitizer represented by the following general formula (I).

However, in the general formula (I), R ₁ , R ₂ , R ₃ and R ₄ each independently represent an alkyl group having 2 to 9 carbon atoms, and D _{1 to} D ₈ each independently represent at least 2 Is a 1,2-naphthoquinone-2-diazidosulfonyl group, at least one of which is an arylsulfonyl group, and the other represents a hydrogen atom. A photoresist composition comprising the 1,2-naphthoquinone-2-diazidosulfonic acid ester-based photosensitizer according to claim 1 and an alkali-soluble resin.