JP3760005B2 - Method for producing photosensitive resin composition - Google Patents

Description

【０００７】
（一般式（Ｉ）中、Ａは炭素数３〜８の直鎖状アルキレン基または炭素数４〜９のアルコキシメチレン基を表わし、Ｒ¹ は水酸基で置換されてもよい炭素数１〜４のアルキル基、Ｒ² 及びＲ³ は炭素数１〜４の炭化水素基、Ｘ^- はアンモニウム基に配位した対イオンを表し、また、ベンゼン環はアルキル基またはハロゲン原子で置換されていてもよい。）
【０００８】
【発明の実施の形態】
以下、本発明を更に詳細に説明する。
本発明における感光性化合物としては、通常、キノンジアジド系感光性化合物、アジド系化合物、光酸発生化合物等があげられ、本発明においては特にキノンジアジド系感光性化合物において効果が顕著に現れる。キノンジアジド系感光性化合物としては、通常、１，２−ベンゾキノンジアジド−４−スルホン酸エステル化合物又はアミド化合物、１，２−ナフトキノンジアジド−４−スルホン酸エステル化合物又はアミド化合物、１，２−ナフトキノンジアジド−５−スルホン酸エステル化合物又はアミド化合物等が挙げられる。
【０００９】
更に具体的には、メタノール、エチレングリコール等の脂肪族の水酸基を有する化合物；フェノール、クレゾール等のフェノール類：ビスフェノールＡ等のビスフェノール類：４，４’，４”−メチリジントリスフェノール、４，４’−〔１−〔４−〔１−（４−ヒドロキシフェニル）−１−メチルエチル〕フェニル〕エチリデン〕ビスフェノール等のトリスフェノール類：４，４’，４”，４”’−（１，４−フェニレンジメチリジン）テトラキスフェノール等のテトラキスフェノール類：ピロガロール、没食子酸エステル等のピロガロール誘導体：２，３，４−トリヒドロキシベンゾフェノン、２，３，４，４’−テトラヒドロキシベンゾフェノン等のポリヒドロキシベンゾフェノン類：後述するノボラック樹脂等のフェノール性の水酸基を有する化合物の、１，２−ベンゾキノンジアジド−４−スルホン酸エステル、１，２−ナフトキノンジアジド−４−スルホン酸エステル、１，２−ナフトキノンジアジド−５−スルホン酸エステル等が挙げられる。更に、エチルアミン、ブチルアミン等の脂肪族のアミノ基を有する化合物；及び／又はアニリン、パラフェニレンジアミン等の芳香族のアミノ基を有する化合物の、１，２−ベンゾキノンジアジド−４−スルホン酸アミド、１，２−ナフトキノンジアジド−４−スルホン酸アミド、１，２−ナフトキノンジアジド−５−スルホン酸アミド等が挙げられる。
【００１０】
本発明におけるアルカリ可溶性樹脂としては、一般的にはノボラック樹脂、ポリビニルフェノール樹脂が挙げられ、特にノボラック樹脂が好ましい。
ノボラック樹脂としては、▲１▼フェノール類；ｏ−クレゾール、ｍ−クレゾール、ｐ−クレゾール、３−エチルフェノール、２，５−キシレノール、３，４−キシレノール、３，５−キシレノール等のアルキルフェノール類；２−メトキシフェノール、４−メトキシフェノール、４−フェノキシフェノール等のアルコキシ又はアリールオキシフェノール類；α−ナフトール、β−ナフトール、３−メチル−α−ナフトール等のアルキル基で置換されていてもよいナフトール類；レゾルシノール、２−メチルレゾルシノール、ピロガロール、５−メチルピロガロール等のアルキル基で置換されていてもよいポリヒドロキシベンゼン類等のフェノール性の水酸基を有する化合物と、▲２▼ホルムアルデヒド、パラホルムアルデヒド、アセトアルデヒド、パラアルデヒド等の脂肪族アルデヒド類；ベンズアルデヒド等の芳香族アルデヒド類；アセトン等のアルキルケトン類等のカルボニル化合物とを、例えば塩酸、硫酸、蓚酸等の酸性触媒の存在下、加熱し、重縮合させることにより製造されたもの等が挙げられる。なお、この重縮合反応は、エタノール、エチルセロソルブアセテート、３−メトキシプロピオン酸メチル等の反応に不活性な溶媒中にて、又は無溶媒中にて行うことができる。
【００１１】
一方、ポリビニルフェノール樹脂としては、芳香環がアルキル基、ハロゲン原子等にて置換されていてもよい４−ヒドロキシスチレンを主成分として重合させた樹脂が挙げられる。このポリビニルフェノール樹脂は一部の水酸基がエステル基等にて置換されていてもよい。
本発明における有機溶媒としては、感光性化合物等を溶解させる高い溶解能力が必要であり、以下の極性有機溶媒が一般的に使用される。即ち、一般的に常圧にて１００〜２００℃の沸点を有し、しかもイオン交換樹脂を浸食しないものが好ましく、次の有機溶媒を主成分とする溶媒が特に好ましい。即ち、酢酸ブチル、酢酸アミル等の脂肪族カルボン酸エステル類；メチルイソブチルケトン、メチルアミルケトン、シクロペンタノン、シクロヘキサノン等の脂肪族又は脂環式ケトン類；ジエチレングリコールジメチルエーテル等の脂肪族エーテル類；メチルセロソルブアセテート、エチルセロソルブアセテート、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、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メチル、３−エトキシプロピオン酸エチル等の脂肪族エーテルエステル類；ピルビン酸エチル等の脂肪族ケトンエステル類；乳酸メチル、乳酸エチル等の脂肪族ヒドロキシカルボン酸エステル類；ジアセトンアルコール等の脂肪族ヒドロキシケトン類；ジアセトンアルコールモノメチルエーテル等の脂肪族エーテルケトン類；プロピレングリコールモノメチルエーテル、エチルセロソルブ等の脂肪族エーテルアルコール類等が挙げられる。これらの有機溶媒は酢酸エチル、キシレン、Ｎ，Ｎ−ジメチルホルムアミド、Ｎ−メチルピロリドン等の他の有機溶媒と混合して使用してもよいが、この場合上記有機溶媒を５０％以上含むものが好ましい。
【００１２】
本発明では上述のような感光性化合物及び／又はアルカリ可溶性樹脂を上記有機溶媒に溶解してなる溶液を陰イオン交換樹脂により処理するが、感光性化合物及び／又はアルカリ可溶性樹脂の濃度は通常、１〜５０重量％であり、又この溶液中に含まれる陰イオン不純物成分は原料やその製造法等にも依存するが、例えば、５０〜２０００ｐｐｍ程度である。
【００１３】
本発明における陰イオン交換樹脂としては、前記の一般式（Ｉ）で表される４級アンモニウム塩基を有する構造単位および不飽和炭化水素基含有架橋性モノマーから誘導される構造単位を含有する。
【００１４】
一般式（Ｉ）において、Ａは炭素数３〜８の直鎖状アルキレン基または炭素数４〜９のアルコキシメチレン基を表わすが、直鎖状アルキレン基としては、例えば、プロピレン基、ブチレン基、ペンチレン基、ヘキシレン基などが挙げられ、アルコキシメチレン基としては、ブトキシメチレン基、ペントキシメチレン基などが挙げられる。
【００１５】
一般式（Ｉ）において、Ｒ¹ は水酸基で置換されてもよい炭素数１〜４のアルキル基、Ｒ² 及びＲ³ は、炭素数１〜４のアルキル基を表すが、これらのアルキル基としては、メチル基、エチル基、プロピレン基、ブチレン基などが挙げられる。
【００１６】
一般式（Ｉ）において、Ｘ^- はアンモニウム基に配位した対イオンを表すが、その具体としては、Ｃｌ^- ，Ｂｒ^- ，Ｉ^- 等のハロゲンイオン、硫酸イオン、ＮＯ₃ ^- 、ＯＨ^- 、ｐ−トルエンスルホン酸イオン等の陰イオンが挙げられる。そして、陰イオンが硫酸イオンの様に２価である場合は、一般式（Ｉ）で表される構造単位２分子に対して陰イオン１分子が結合する。また、ベンゼン環は、さらにアルキル基またはハロゲン原子で置換されていてもよく、置換基のアルキル基としては、メチル基、エチル基などが挙げられ、ハロゲン原子としては、塩素、臭素、沃素などが挙げられる。
本発明においては、通常Ｘ^- の大部分を水酸化ナトリウム等にてＯＨ^- に変換し用いるのが好ましい。
【００１７】
一般式（Ｉ）において、Ｒ² 及びＲ³ はメチル基が好ましく、更にはＲ¹ がメチル基であるトリメチルアンモニウム塩基（Ｉ型強塩基性樹脂）、又はＲ¹ がヒドロキシエチル基であるジメチルヒドロキシエチルアンモニウム塩基（II型強塩基性樹脂) が好ましい。
【００１８】
不飽和炭化水素基含有架橋性モノマーとしては、ジビニルベンゼン、トリビニルベンゼン、ジビニルトルエン、ジビニルナフタレン、ジビニルキシレン、エチレングリコールジメタクリレート、ジエチレングリコールジメタクリレート、トリメチロールプロパントリメタクリレート等が挙げられる。これらの中ではジビニルベンゼンが好ましい。
【００１９】
本発明で使用する陰イオン交換樹脂においては、全陰イオン交換基に対する一般式（Ｉ）で表される４級アンモニウム基の割合は９０％以上がであることが好ましく、全陰イオン交換基の実質的全量が一般式（Ｉ）で表される４級アンモニウム基であることが特に好ましい。
【００２０】
本発明で使用する陰イオン交換樹脂は、例えば、特開平７−２８９９２１号公報に記載されて公知であり、その用途例の幾つかは、特開平５−４９９５０号公報、同５−４９９５１号公報、同５−４９９５２号公報、同５−５７２００号公報に記載されて公知である。しかしながら、これらの公報には、極性有機溶剤の精製のみならず、感光性樹脂組成物の精製に上記の陰イオン交換樹脂を使用することは記載されていない。
【００２１】
一方、特公平２−４２５４２号公報には、本発明で使用する陰イオン交換樹脂に類似した構造の樹脂が記載されている。この樹脂は、−Ｃn Ｈ₂n−Ｘで表されるハロアルキル基（式中、Ｘは塩素または臭素原子、ｎは１〜４の整数）を有する架橋共重合体に３級アミンを反応させて得られるが、上記の公報に具体的に開示されているのは、上記の整数ｎが１である樹脂のみである。
【００２２】
整数ｎが３又は４の樹脂は、開示された方法に準じて製造した場合、−（ＣＨ₂ ）₃ −Ｘまたは−（ＣＨ₂ ）₄ −Ｘで表されるハロアルキル基から誘導される陰イオン交換基の量が非常に少ない。そして、上記の整数ｎが１である強塩基性陰イオン交換樹脂は、極性有機溶剤による劣化が大きく、極性有機溶剤中での精製には使用するのは無理である。
【００２３】
本発明で共存させても良い陽イオン交換樹脂としては、例えばスチレン系、フェノール系の強酸性陽イオン交換樹脂が挙げられ、特にスチレン−ジビニルベンゼン系のスルホン酸型陽イオン交換樹脂が好ましい。具体的には、例えば、三菱化成（株）製のＳＫ１Ｂ、ＳＫ１０４、ＳＫ１１６のようなゲル型の強酸性陽イオン交換樹脂やＰＫ２１６、ＰＫ２０８、ＰＫ２２８、ＨＰＫ１６のようなポーラス型の強酸性陽イオン交換樹脂が挙げられる。本発明においては、特にゲル型の強酸性陽イオン交換樹脂が好ましい。
【００２４】
これら市販の陽イオン交換樹脂は通常Ｎａ型であるが、本発明ではこれをＨ型とした後、用いる必要がある。この処理方法としては、通常１〜１０重量％の塩酸水溶液をＮａ型樹脂に接触させＨ型とすることができる。この場合、通常０〜２０％程度のＮａ型樹脂が残存してもよい。
陽イオン交換樹脂、陰イオン交換樹脂ともにゲル型のイオン交換樹脂が好ましいがこの架橋度は２〜２０％の範囲のものが好ましく、又、粒径は０．１〜２ｍｍ程度が好ましく、０．２〜１ｍｍ程度がさらに好ましい。これらイオン交換樹脂は通常、水湿潤状態にて入手でき、これをこのまま使用してもよいが、予め乾燥し、又は感光性樹脂組成物溶液等を調製する溶媒等にて溶媒置換して使用してもよい。
【００２５】
陰イオン交換樹脂を接触させる方法としては、（１）処理すべき有機溶媒溶液に陰イオン交換樹脂単独又は陽イオン交換樹脂を共存させ、懸濁、混合、攪拌する方法、又は、（２）陰イオン交換樹脂単独又は陽イオン交換樹脂を共存させ充填した層に処理すべき有機溶媒溶液を通過させる方法等により行うことができる。
【００２６】
陰イオン交換樹脂の使用量は通常前記溶液に対し、０．０１〜２０容量％、好ましくは０．０５〜１０容量％、更に好ましくは０．１〜５容量％である。又、陽イオン交換樹脂の使用量は特に制限はないが、あまり多くても効果は同じであり、又、逆に少なすぎると、保存安定性等が低下する等の悪影響がでることがあり、通常、陰イオン交換樹脂の使用量の０．０５〜５．０倍程度、好ましくは０．２〜２．０倍程度用いるのがよい。イオン交換樹脂との接触時間は上記（１）の方法においては通常０．１〜１００時間、好ましくは０．５〜５０時間、更に好ましくは１〜３０時間であり、上記（２）の方法においてはＳＶ（容量速度）にて１時間あたり通常０．１〜１００、好ましくは０．５〜５０、更に好ましくは１〜３０である。イオン交換樹脂を共存させる条件は特に限定はないが、常圧にて、０〜４０℃にて行うのがよい。
【００２７】
本発明は、感光性樹脂組成物溶液に陰イオン交換樹脂を接触させ陰イオン不純物を吸着除去させることを基本とするが、不純物の混入程度、陰イオン交換樹脂の吸着効率等を勘案し、感光性樹脂組成物の接触処理に限らず、感光性樹脂組成物の調製段階も含めて、感光性化合物を溶媒に溶解してなる溶液又はアルカリ可溶性樹脂を溶媒に溶解してなる溶液について、陰イオン交換樹脂を接触させ陰イオン不純物を吸着除去することを含む。
【００２８】
目標とする陰イオン不純物の濃度は必要に応じ異なるが、本方法においては通常１０ｐｐｍ以下に、更に、条件を選定すれば１ｐｐｍ以下の高純度も達成できる。このようにして得られる精製後の溶液は通常、最終的にイオン交換樹脂を濾過、除去し、必要に応じ、感光性化合物又はアルカリ可溶性樹脂等を溶解させ、フォトリソグラフィー工程に使用される。
【００２９】
【実施例】
以下、実施例により更に詳細に本発明の内容を説明するが、本発明はこれらの実施例に限定されないことはいうまでもない。
なお、以下の記載においてｍｅｑ／ｇは、乾燥樹脂重量当たりのミリ当量を表す。また、陰イオン交換樹脂の交換容量は、ダイヤイオンマニュアル（三菱化学社発行）に従って測定した。
【００３０】
製造例１
＜４−ブロモブチルスチレンの合成（１）＞
窒素ガス導入管、ジムロー冷却管、枝管付き等圧滴下ロート及び攪拌羽根を備えた１０００ｍｌの分液ロート型４ツ口フラスコに金属マグネシウム５２. ５ｇ（２. １６グラム原子）とテトラヒドロフラン（ＴＨＦ）３６０ｍｌを入れ、内温を３０℃に設定した。このフラスコにｐ−クロロスチレン（ＣＳ）２５１ｇ（１. ８１モル）のＴＨＦ溶液３５０ｍｌを内温が４０℃以上にならない様に２時間かけて滴下し、ＣＳのグリニャール試薬を得た。
【００３１】
上記のフラスコの下に、前記と同様の構造の２０００ｍｌの４ツ口フラスコを連結し、その中に１, ４−ジブロモブタン１０６０ｇ（４. ９１モル、２. ７１当量／ＣＳ）、ＴＨＦ６００ｍｌ、カップリング触媒Ｌｉ2 C ｕＣｌ4 7.５ｇ（０. ０３４モル、１. ９モル％／ＣＳ）を加えて溶液を調製した。次いで、このフラスコの溶液中に上記で調製したＣＳのグリニャール溶液を室温で１時間で滴下した。
【００３２】
得られた溶液を水に投入した後に分液し、水相を除去した。減圧下で有機相を留去し、大過剰に使用した１, ４−ジブロモブタン（ｂ. ｐ. ５２℃／０. ５ｍｍＨｇ）、未反応のＣＳを留去し、最後に目的物である４−ブロモブチルスチレン（淡黄色透明溶液、ｂｐ. １３０℃／０. ２ｍｍＨｇ）を得た。
【００３３】
＜４−ブロモブチルスチレン架橋共重合体の合成（２）＞
窒素ガス導入管と冷却管を備えた５００ｍｌの４ツ口フラスコに脱塩水２００ｍｌ、２％ポリビニルアルコール水溶液５０ｍｌを加え、窒素を導入して溶存酸素を除去した。一方、合成（１）で得られた４−ブロモブチルスチレン７８. ０ｇ（０. ３２６モル）、ジビニルベンゼン３. ２５ｇ（０. ０２００モル）（ジビニルベンゼン含有率８０％）及びベンゾイルパーオキシド（ＢＰＯ）（含有率７５％）０. ６７ｇを溶解してモノマー溶液を調製した。
【００３４】
得られたモノマー溶液を上記フラスコに入れ、１６０ｒｐｍで撹拌し、懸濁液を調製した。室温で３０分撹拌後、８０℃に昇温して１２時間撹拌して懸濁重合を行って淡黄色透明球状重合体を得た。次いで、得られた重合体を取り出して水洗した。重合収率は９５％であり、重合体の仕込み架橋度は６モル％であった。
【００３５】
＜４−ブロモブチルスチレン架橋共重合体のアミノ化＞
冷却管を備えた５００ｍｌの４ツ口フラスコに合成（２）で得た重合体 ｇを入れ、１, ４−ジオキサン２００ｍｌを加えて室温で撹拌した。次いで、３０％のトリメチルアミン水溶液１７７ｇ（０. ９０モル）を加えて５０℃で６時間反応を行って陰イオン交換樹脂Ａを得た。次いで、得られた陰イオン交換樹脂Ａを取り出して水洗した。陰イオン交換樹脂Ａの全陰イオン交換基の実質的全量は一般式（Ｉ）で表される４級アンモニウム基である。
【００３６】
上記の陰イオン交換樹脂Ａの対イオンを臭化物イオンから塩化物イオン（Ｃｌ型）に変換するため、樹脂量に対して１０倍量の４％塩化ナトリウム水溶液を通液した。得られたＣｌ型陰イオン交換樹脂Ａの中性塩分解容量は１．２４ｍｅｑ／ｍｌ（３．５７ｍｅｑ／ｇ）、含水率は４８．９％であった。
更に、このＣｌ型陰イオン交換樹脂Ａ５００ｍｌを秤量し、５０００ｍｌの２Ｎ−水酸化ナトリウム水溶液を通液してＯＨ型とした。
【００３７】
実施例１、比較例１、２
ピロガロールとアセトンを重縮合させて得られた樹脂と１，２−ナフトキノンジアジド−５−スルホン酸クロリドとから常法に従い合成したキノンジアジド系感光性化合物１１６ｇ、 ２，２’，３，４，４’−ペンタヒドロキシベンゾフェノンと１，２−ナフトキノンジアジド−５−スルホン酸クロリドとから常法に従い合成したキノンジアジド系感光性化合物１４０ｇ、ｍ−クレゾール、ｐ−クレゾール、２，５−キシレノール及びホリマリンより常法に従い合成したノボラック樹脂７２０ｇ、予め乳酸エチルにて溶媒置換した、上記製造例１のＯＨ型の陰イオン交換樹脂、１２０ｍｌ、及び三菱化学社製のＨ型の陽イオン交換樹脂、ＳＫ１Ｂ １２０ｍｌを乳酸エチルとプロピレングリコールメチルエーテルアセテートの混合溶媒（重量混合比７：３）２６２０ｇに加え、室温にて４８時間かけ攪拌、溶解し、０．１μｍのフィルターにて濾過し、感光性樹脂組成物（Ａ−１）を調製した。この感光性樹脂組成物（Ａ−１）中の塩化物のイオン（Ｃｌ- ）の濃度は１０ｐｐｍ以下であった。
【００３８】
イオン交換樹脂を共存させない他は全く同一の原料、装置にて感光性樹脂組成物（Ａ−２）を調製したが、この感光性樹脂組成物（Ａ−２）中の塩化物のイオン（Ｃｌ- ）の濃度は１２４ｐｐｍであった。
又、陰イオン交換樹脂として三菱化学社製の陰イオン交換樹脂 ＳＡ１０Ａ （請求項１の一般式においてＡが炭素数１のメチレン基の陰イオン交換樹脂）を用いた他は全く同一の原料、装置にて感光性樹脂組成物（Ａ−３）を調製した。この感光性樹脂組成物（Ａ−３）中の塩化物のイオン（Ｃｌ- ）の濃度は１０ｐｐｍ以下であった。
又、感光性樹脂組成物（Ａ−１）、（Ａ−２）、（Ａ−３）の感度を測定したが全ての感度は同じであった。
これらの組成物を２３℃のクリーンルームに放置し微粒子の発生を観察したところ、感光性樹脂組成物（Ａ−１）、（Ａ−２）では、６ケ月間感光剤の析出等の微粒子の発生は認められなかったが、（Ａ−３）では５ヶ月経過後に微粒子の発生が認められた。
【００３９】
【発明の効果】
本発明方法によれば、感光性樹脂組成物中の陰イオンを工業的に容易な設備、操作、費用で低濃度にまで除去することができる上、この方法によって感光性樹脂の感度や保存安定性にも影響がないため、得られる感光性樹脂組成物は、ＩＣ製造用フォトレジスト等として極めて有用である。[0001]
[Industrial application fields]
The present invention relates generally to a method for producing a photosensitive resin composition that is sensitive to light, and more particularly to a method for producing a high-purity photosensitive resin composition obtained by dissolving a photosensitive compound and an alkali-soluble resin in an organic solvent. Is.
[0002]
[Prior art]
The integrated circuit is highly integrated every year. Taking a dynamic random access memory (DRAM) as an example, full-scale production of a storage capacity of 16 Mbits has started. Accordingly, the demand for photolithography technology that is indispensable for the production of integrated circuits is becoming stricter year by year. For example, in a 16 Mbit DRAM, a photolithography technology of 0.5 μm level is required.
[0003]
As a result, the amount of impurities mixed in the photosensitive resin composition used for photolithography is required to be low, and low levels of anions such as chlorine ions have been required in addition to conventional metal impurities.
However, for the synthesis of the photosensitive compound, for example, an acid chloride such as 1,2-naphthoquinonediazide-5-sulfonic acid chloride is used as a raw material, while the raw material of the photosensitive resin composition is a production intermediate except for a solvent. Since many of them are solid at room temperature, it is generally difficult to carry out distillation purification that can easily remove nonvolatile impurities. For this reason, considering the impurities mixed in during the manufacturing operation of the photosensitive resin composition, it is technically difficult to achieve an anionic impurity mixing amount of, for example, 30 ppm or less, and further 10 ppm or less with the current method. It was.
These anionic impurities can be adsorbed and removed by an anion exchange resin. However, this method has a problem in long-term storage stability of the obtained photosensitive resin composition and cannot be an industrial method. In other words, storage stability does not cause problems at room temperature (20-25 ° C) for 1-2 months, but insoluble particles are generated in the liquid when stored for 6 months or longer. However, it has been found to be a problem when the photosensitive resin composition is used at an industrial level.
[0004]
[Problems to be solved by the invention]
The present invention has been made in view of the above circumstances, and its purpose is to provide industrially easy equipment, operation, and cost in a photosensitive resin composition obtained by dissolving a photosensitive compound and an alkali-soluble resin in an organic solvent. Provides a method for reducing the amount of mixed anionic impurities and providing a photosensitive resin composition having good storage stability over a long period of time.
[0005]
[Means for Solving the Problems]
As a result of various studies to achieve the above object, the present inventors have found that the application of an anion exchange resin having a specific structure meets the above object, and the present invention has been completed.
That is, the gist of the present invention is a method for producing a photosensitive resin composition in which a photosensitive compound and an alkali-soluble resin are dissolved in an organic solvent, and a solution in which the photosensitive compound and / or the alkali-soluble resin is dissolved in an organic solvent. Quaternary ammonium represented by the following general formula (I) as the anion exchange resin, wherein the anion exchange resin has a step of adsorbing impurities to the ion exchange resin to reduce the amount of impurities mixed The present invention resides in a method for producing a photosensitive resin composition, comprising using an anion exchange resin containing a structural unit having a base and a structural unit derived from an unsaturated hydrocarbon group-containing crosslinking monomer.
[0006]
[Chemical 2]

[0007]
(In general formula (I), A represents a linear alkylene group having 3 to 8 carbon atoms or an alkoxymethylene group having 4 to 9 carbon atoms, and R ¹ has 1 to 4 carbon atoms which may be substituted with a hydroxyl group. An alkyl group, R ² and R ³ are each a hydrocarbon group having 1 to 4 carbon atoms, X ⁻ represents a counter ion coordinated to an ammonium group, and the benzene ring may be substituted with an alkyl group or a halogen atom. .)
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in more detail.
Examples of the photosensitive compound in the present invention usually include a quinonediazide-based photosensitive compound, an azide-based compound, a photoacid-generating compound, and the like. In the present invention, the effect is particularly remarkable in a quinonediazide-based photosensitive compound. As the quinonediazide-based photosensitive compound, usually, 1,2-benzoquinonediazide-4-sulfonic acid ester compound or amide compound, 1,2-naphthoquinonediazide-4-sulfonic acid ester compound or amide compound, 1,2-naphthoquinonediazide Examples include -5-sulfonic acid ester compounds and amide compounds.
[0009]
More specifically, compounds having an aliphatic hydroxyl group such as methanol and ethylene glycol; phenols such as phenol and cresol; bisphenols such as bisphenol A: 4,4 ′, 4 ″ -methylidynetrisphenol, 4, Trisphenols such as 4 ′-[1- [4- [1- (4-hydroxyphenyl) -1-methylethyl] phenyl] ethylidene] bisphenol: 4,4 ′, 4 ″, 4 ″ ′-(1, Tetrakisphenols such as 4-phenylenedimethylidyne) tetrakisphenol: pyrogallol derivatives such as pyrogallol and gallic acid esters: polyhydroxy such as 2,3,4-trihydroxybenzophenone and 2,3,4,4′-tetrahydroxybenzophenone Benzophenones: have phenolic hydroxyl groups such as novolak resins described later 1,2-benzoquinonediazide-4-sulfonic acid ester, 1,2-naphthoquinonediazide-4-sulfonic acid ester, 1,2-naphthoquinonediazide-5-sulfonic acid ester, etc., and ethylamine. 1,2-benzoquinonediazide-4-sulfonic acid amide of a compound having an aliphatic amino group such as butylamine; and / or a compound having an aromatic amino group such as aniline or paraphenylenediamine, 1,2- Examples thereof include naphthoquinonediazide-4-sulfonic acid amide and 1,2-naphthoquinonediazide-5-sulfonic acid amide.
[0010]
Examples of the alkali-soluble resin in the present invention generally include novolak resins and polyvinylphenol resins, and novolak resins are particularly preferable.
As the novolak resin, (1) phenols; alkylphenols such as o-cresol, m-cresol, p-cresol, 3-ethylphenol, 2,5-xylenol, 3,4-xylenol, 3,5-xylenol; Alkoxy or aryloxyphenols such as 2-methoxyphenol, 4-methoxyphenol and 4-phenoxyphenol; naphthol optionally substituted with an alkyl group such as α-naphthol, β-naphthol and 3-methyl-α-naphthol A compound having a phenolic hydroxyl group such as polyhydroxybenzenes optionally substituted with an alkyl group such as resorcinol, 2-methylresorcinol, pyrogallol, 5-methylpyrogalol, and (2) formaldehyde, paraformaldehyde, acetaldehyde Aliphatic aldehydes such as aldehyde and paraaldehyde; aromatic aldehydes such as benzaldehyde; and carbonyl compounds such as alkyl ketones such as acetone in the presence of an acidic catalyst such as hydrochloric acid, sulfuric acid, and oxalic acid. Examples thereof include those produced by condensation. This polycondensation reaction can be carried out in a solvent inert to the reaction such as ethanol, ethyl cellosolve acetate, methyl 3-methoxypropionate, or in the absence of a solvent.
[0011]
On the other hand, examples of the polyvinylphenol resin include resins obtained by polymerizing, as a main component, 4-hydroxystyrene in which an aromatic ring may be substituted with an alkyl group, a halogen atom, or the like. In this polyvinyl phenol resin, some hydroxyl groups may be substituted with ester groups or the like.
As the organic solvent in the present invention, a high dissolving ability for dissolving a photosensitive compound or the like is necessary, and the following polar organic solvents are generally used. That is, those having a boiling point of 100 to 200 ° C. at normal pressure and not eroding the ion exchange resin are preferable, and solvents having the following organic solvent as a main component are particularly preferable. That is, aliphatic carboxylic acid esters such as butyl acetate and amyl acetate; aliphatic or alicyclic ketones such as methyl isobutyl ketone, methyl amyl ketone, cyclopentanone and cyclohexanone; aliphatic ethers such as diethylene glycol dimethyl ether; Aliphatic ether esters such as cellosolve acetate, ethyl cellosolve acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, methyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate; pyruvic acid Aliphatic ketone esters such as ethyl; aliphatic hydroxycarboxylic esters such as methyl lactate and ethyl lactate; aliphatic hydroxy ketones such as diacetone alcohol; Aliphatic ethers ketones such as seton alcohol monomethyl ether; propylene glycol monomethyl ether, aliphatic ether alcohols such as ethyl cellosolve, and the like. These organic solvents may be used by mixing with other organic solvents such as ethyl acetate, xylene, N, N-dimethylformamide, N-methylpyrrolidone, etc., but in this case, those containing 50% or more of the above organic solvent. preferable.
[0012]
In the present invention, a solution obtained by dissolving the above-described photosensitive compound and / or alkali-soluble resin in the organic solvent is treated with an anion exchange resin. The concentration of the photosensitive compound and / or alkali-soluble resin is usually The anionic impurity component contained in the solution is, for example, about 50 to 2000 ppm, although it depends on the raw material and the production method thereof.
[0013]
The anion exchange resin in the present invention contains a structural unit having a quaternary ammonium base represented by the general formula (I) and a structural unit derived from an unsaturated hydrocarbon group-containing crosslinking monomer.
[0014]
In general formula (I), A represents a linear alkylene group having 3 to 8 carbon atoms or an alkoxymethylene group having 4 to 9 carbon atoms. Examples of the linear alkylene group include a propylene group, a butylene group, A pentylene group, a hexylene group, etc. are mentioned, As an alkoxymethylene group, a butoxymethylene group, a pentoxymethylene group, etc. are mentioned.
[0015]
In the general formula (I), R ¹ represents an alkyl group having 1 to 4 carbon atoms which may be substituted with a hydroxyl group, and R ² and R ³ represent an alkyl group having 1 to 4 carbon atoms. Includes a methyl group, an ethyl group, a propylene group, a butylene group, and the like.
[0016]
In the general formula (I), X ⁻ represents a counter ion coordinated to an ammonium group. Specific examples thereof include halogen ions such as Cl ⁻ , Br ⁻ and I ⁻ , sulfate ions, NO ₃ ⁻ , OH ⁻ , Examples include anions such as p-toluenesulfonic acid ions. And when an anion is bivalent like a sulfate ion, one anion molecule | numerator couple | bonds with two structural units represented by general formula (I). Further, the benzene ring may be further substituted with an alkyl group or a halogen atom. Examples of the alkyl group of the substituent include a methyl group and an ethyl group. Examples of the halogen atom include chlorine, bromine and iodine. Can be mentioned.
In the present invention, it is usually preferable to convert most of X ⁻ to OH ⁻ with sodium hydroxide or the like.
[0017]
In general formula (I), R ² and R ³ are preferably methyl groups, and further, trimethylammonium base (type I strongly basic resin) in which R ¹ is a methyl group, or dimethylhydroxy group in which R ¹ is a hydroxyethyl group. Ethylammonium base (type II strongly basic resin) is preferred.
[0018]
Examples of the unsaturated hydrocarbon group-containing crosslinking monomer include divinylbenzene, trivinylbenzene, divinyltoluene, divinylnaphthalene, divinylxylene, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, and trimethylolpropane trimethacrylate. Of these, divinylbenzene is preferred.
[0019]
In the anion exchange resin used in the present invention, the ratio of the quaternary ammonium group represented by the general formula (I) to the total anion exchange group is preferably 90% or more. It is particularly preferable that the substantially total amount is a quaternary ammonium group represented by the general formula (I).
[0020]
The anion exchange resin used in the present invention is known, for example, described in JP-A-7-289921, and some examples of its use are described in JP-A-5-49950 and JP-A-5-49951. Are disclosed in JP-A-5-49952 and 5-57200. However, these publications do not describe the use of the above anion exchange resin not only for the purification of polar organic solvents but also for the purification of photosensitive resin compositions.
[0021]
On the other hand, JP-B-2-42542 discloses a resin having a structure similar to the anion exchange resin used in the present invention. The resin (wherein, X is chlorine or bromine atoms, n represents an integer of 1 to 4) haloalkyl group represented by -Cn H ₂ n-X is reacted with a tertiary amine crosslinked copolymer having Although obtained, only the resin whose integer n is 1 is specifically disclosed in the above publication.
[0022]
A resin having an integer n of 3 or 4 is an anion derived from a haloalkyl group represented by — (CH ₂ ) ₃ —X or — (CH ₂ ) ₄ —X when prepared according to the disclosed method. The amount of exchange groups is very small. The strongly basic anion exchange resin having the integer n of 1 is greatly deteriorated by the polar organic solvent, and cannot be used for purification in the polar organic solvent.
[0023]
Examples of the cation exchange resin that may coexist in the present invention include styrene-based and phenol-based strongly acidic cation exchange resins, and styrene-divinylbenzene-based sulfonic acid type cation exchange resins are particularly preferable. Specifically, for example, gel-type strongly acidic cation exchange resins such as SK1B, SK104, and SK116 manufactured by Mitsubishi Kasei Co., Ltd. and porous strong acid cation exchanges such as PK216, PK208, PK228, and HPK16 Resin. In the present invention, a gel-type strongly acidic cation exchange resin is particularly preferable.
[0024]
These commercially available cation exchange resins are usually Na-type, but in the present invention, they must be used after being made H-type. As this treatment method, an aqueous hydrochloric acid solution of 1 to 10% by weight is usually brought into contact with the Na-type resin to form an H-type. In this case, about 0 to 20% of Na-type resin may usually remain.
Both the cation exchange resin and the anion exchange resin are preferably gel-type ion exchange resins, but the degree of crosslinking is preferably in the range of 2 to 20%, and the particle size is preferably about 0.1 to 2 mm. About 2 to 1 mm is more preferable. These ion exchange resins are usually available in a wet state in water, and may be used as they are. However, they are used in advance, or are used after being dried in advance or with a solvent or the like for preparing a photosensitive resin composition solution. May be.
[0025]
Examples of the method of bringing the anion exchange resin into contact include (1) a method in which an anion exchange resin alone or a cation exchange resin is allowed to coexist in an organic solvent solution to be treated and suspended, mixed, or stirred, or (2) an anion. It can be carried out by a method of passing an organic solvent solution to be treated through a layer packed with ion exchange resin alone or cation exchange resin.
[0026]
The amount of the anion exchange resin used is usually 0.01 to 20% by volume, preferably 0.05 to 10% by volume, and more preferably 0.1 to 5% by volume with respect to the solution. The amount of the cation exchange resin is not particularly limited, but the effect is the same even if it is too much. On the other hand, if it is too little, there may be adverse effects such as a decrease in storage stability. Usually, the amount of anion exchange resin used is about 0.05 to 5.0 times, preferably about 0.2 to 2.0 times. The contact time with the ion exchange resin is usually 0.1 to 100 hours, preferably 0.5 to 50 hours, more preferably 1 to 30 hours in the method (1). In the method (2), Is usually from 0.1 to 100, preferably from 0.5 to 50, more preferably from 1 to 30 per hour in SV (capacity rate). The conditions for allowing the ion exchange resin to coexist are not particularly limited, but it is preferably performed at 0 to 40 ° C. at normal pressure.
[0027]
The present invention is based on contact of an anion exchange resin with a photosensitive resin composition solution to adsorb and remove anion impurities. However, in consideration of the degree of impurity contamination, anion exchange resin adsorption efficiency, etc. In addition to the contact treatment of the photosensitive resin composition, including the preparation step of the photosensitive resin composition, the anion is used for a solution obtained by dissolving a photosensitive compound in a solvent or a solution obtained by dissolving an alkali-soluble resin in a solvent. Contacting an exchange resin to adsorb and remove anionic impurities.
[0028]
Although the target concentration of anionic impurities varies depending on necessity, it is usually 10 ppm or less in this method, and further, high purity of 1 ppm or less can be achieved if conditions are selected. The purified solution thus obtained is usually finally filtered and removed from the ion exchange resin, and if necessary, the photosensitive compound or the alkali-soluble resin is dissolved and used in the photolithography process.
[0029]
【Example】
EXAMPLES Hereinafter, although the content of this invention is demonstrated in detail by an Example, it cannot be overemphasized that this invention is not limited to these Examples.
In the following description, meq / g represents milliequivalents per dry resin weight. The exchange capacity of the anion exchange resin was measured according to Diaion Manual (issued by Mitsubishi Chemical Corporation).
[0030]
Production Example 1
<Synthesis of 4-bromobutylstyrene (1)>
Into a 1000 ml separatory funnel type four-necked flask equipped with a nitrogen gas inlet tube, a Dimro condenser tube, an isobaric dropping funnel with a branch tube and a stirring blade, 52.5 g (2.16 gram atoms) of metal magnesium and tetrahydrofuran (THF) 360 ml was added and the internal temperature was set to 30 ° C. To this flask, 350 ml of a THF solution of 251 g (1.81 mol) of p-chlorostyrene (CS) was added dropwise over 2 hours so that the internal temperature did not rise to 40 ° C. or higher to obtain a CS Grignard reagent.
[0031]
A 2000 ml four-necked flask having the same structure as above was connected to the bottom of the flask, and 1060 g (4.91 mol, 2.71 equivalents / CS) of 1,4-dibromobutane, 600 ml of THF, a cup A solution was prepared by adding 7.5 g (0.034 mol, 1.9 mol% / CS) of the ring catalyst Li2CuCl4. Next, the above-prepared Grignard solution of CS was dropped into the flask solution at room temperature for 1 hour.
[0032]
The resulting solution was poured into water and separated to remove the aqueous phase. The organic phase was distilled off under reduced pressure, 1,4-dibromobutane (b.p. 52 ° C./0.5 mmHg) used in large excess and unreacted CS were distilled off, and finally the target product 4 -Bromobutylstyrene (light yellow transparent solution, bp. 130 ° C./0.2 mmHg) was obtained.
[0033]
<Synthesis of 4-Bromobutylstyrene Crosslinked Copolymer (2)>
200 ml of demineralized water and 50 ml of a 2% polyvinyl alcohol aqueous solution were added to a 500 ml four-necked flask equipped with a nitrogen gas introduction tube and a cooling tube, and nitrogen was introduced to remove dissolved oxygen. On the other hand, 78.0 g (0.326 mol) of 4-bromobutylstyrene obtained by synthesis (1), 3.25 g (0.0200 mol) of divinylbenzene (divinylbenzene content 80%) and benzoyl peroxide (BPO) ) (Content 75%) 0.67 g was dissolved to prepare a monomer solution.
[0034]
The obtained monomer solution was put into the flask and stirred at 160 rpm to prepare a suspension. After stirring at room temperature for 30 minutes, the temperature was raised to 80 ° C. and the mixture was stirred for 12 hours for suspension polymerization to obtain a pale yellow transparent spherical polymer. Subsequently, the obtained polymer was taken out and washed with water. The polymerization yield was 95%, and the charged crosslinking degree of the polymer was 6 mol%.
[0035]
<Amination of 4-bromobutylstyrene cross-linked copolymer>
The polymer g obtained in the synthesis (2) was placed in a 500 ml four-necked flask equipped with a condenser, and 200 ml of 1,4-dioxane was added and stirred at room temperature. Next, 177 g (0.90 mol) of a 30% aqueous trimethylamine solution was added, and the reaction was carried out at 50 ° C. for 6 hours to obtain an anion exchange resin A. Subsequently, the obtained anion exchange resin A was taken out and washed with water. The substantially total amount of all anion exchange groups of the anion exchange resin A is a quaternary ammonium group represented by the general formula (I).
[0036]
In order to convert the counter ion of the anion exchange resin A from bromide ion to chloride ion (Cl type), 10% amount of 4% sodium chloride aqueous solution was passed through the resin amount. The resulting Cl-type anion exchange resin A had a neutral salt decomposition capacity of 1.24 meq / ml (3.57 meq / g) and a water content of 48.9%.
Further, 500 ml of this Cl-type anion exchange resin A was weighed, and 5000 ml of 2N-sodium hydroxide aqueous solution was passed through to make OH-type.
[0037]
Example 1, Comparative Examples 1 and 2
116 g of a quinonediazide photosensitive compound synthesized from a resin obtained by polycondensation of pyrogallol and acetone and 1,2-naphthoquinonediazide-5-sulfonic acid chloride according to a conventional method, 2,2 ′, 3,4,4 ′ -140 g of a quinonediazide photosensitive compound synthesized according to a conventional method from pentahydroxybenzophenone and 1,2-naphthoquinonediazide-5-sulfonic acid chloride, according to a conventional method from m-cresol, p-cresol, 2,5-xylenol and hollimarin 120 ml of the synthesized novolak resin, 120 ml of the OH type anion exchange resin of Preparation Example 1 previously substituted with ethyl lactate, 120 ml of the cation exchange resin of Mitsubishi Chemical Corporation, and 120 ml of SK1B with ethyl lactate Propylene glycol methyl ether acetate mixed solvent (weight mixing Ratio 7: 3) In addition to 2620 g, the mixture was stirred and dissolved at room temperature for 48 hours, and filtered through a 0.1 μm filter to prepare a photosensitive resin composition (A-1). The concentration of chloride ions (Cl-) in the photosensitive resin composition (A-1) was 10 ppm or less.
[0038]
A photosensitive resin composition (A-2) was prepared using exactly the same raw materials and equipment except that no ion exchange resin was allowed to coexist. The chloride ions (Cl in this photosensitive resin composition (A-2)) were prepared. The concentration of-) was 124 ppm.
Also, the anion exchange resin SA10A manufactured by Mitsubishi Chemical Co., Ltd. (an anion exchange resin having a methylene group having 1 carbon atom in the general formula of claim 1) was used as the anion exchange resin. A photosensitive resin composition (A-3) was prepared. The concentration of chloride ions (Cl-) in the photosensitive resin composition (A-3) was 10 ppm or less.
Moreover, although the sensitivity of photosensitive resin composition (A-1), (A-2), (A-3) was measured, all the sensitivity was the same.
When these compositions were allowed to stand in a clean room at 23 ° C. and the generation of fine particles was observed, in the photosensitive resin compositions (A-1) and (A-2), the generation of fine particles such as the precipitation of a photosensitive agent for 6 months. However, in (A-3), generation of fine particles was observed after 5 months.
[0039]
【The invention's effect】
According to the method of the present invention, the anion in the photosensitive resin composition can be removed to a low concentration with industrially easy equipment, operation and cost, and the sensitivity and storage stability of the photosensitive resin can be obtained by this method. The resulting photosensitive resin composition is extremely useful as a photoresist for IC production and the like.

Claims (4)

In a method for producing a photosensitive resin composition obtained by dissolving a photosensitive compound and an alkali-soluble resin in an organic solvent, a solution obtained by dissolving the photosensitive compound and / or the alkali-soluble resin in an organic solvent is brought into contact with the anion exchange resin. A structural unit having a quaternary ammonium base represented by the following general formula (I) and an unsaturated group as the anion exchange resin: The manufacturing method of the photosensitive resin composition characterized by using the anion exchange resin containing the structural unit induced | guided | derived from a hydrocarbon group containing crosslinking | crosslinked monomer.

(In the general formula (I), A represents a linear alkylene group having 3 to 8 carbon atoms or an alkoxymethylene group having 4 to 9 carbon atoms, and R ¹ has 1 to 4 carbon atoms which may be substituted with a hydroxyl group. An alkyl group, R ² and R ³ are each a hydrocarbon group having 1 to 4 carbon atoms, X ⁻ represents a counter ion coordinated to an ammonium group, and the benzene ring may be substituted with an alkyl group or a halogen atom. .) The method for producing a photosensitive resin composition according to claim 1, wherein the cation exchange resin is allowed to coexist with the anion exchange resin. The method for producing a photosensitive resin composition according to claim 1 or 2, wherein the photosensitive compound is a quinonediazide-based photosensitive compound. The method for producing a photosensitive resin composition according to claim 1, wherein the ratio of the quaternary ammonium group represented by the general formula (I) to the total anion exchange groups is 90% or more.