JP2004354610A - Chemically amplified positive photoresist composition and resist pattern forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a chemically amplified positive photoresist composition having good sensitivity and satisfying heat resistance, resolution, linearity and DOF (depth of focus) property required for a photoresist composition used for manufacture of a system LCD (liquid crystal display) in which an integrated circuit and a liquid crystal display section are formed on a single substrate. <P>SOLUTION: The chemically amplified positive photoresist composition for manufacture of a substrate on which an integrated circuit and a liquid crystal display section are formed on a single substrate contains (A) a resin component, (C) a compound which generates an acid component upon irradiation with a radiation, and an organic solvent, and has solubility in an alkaline aqueous solution increased by the action of an acid component generated from the component (C). The mass average molecular weight (Mw) (expressed in terms of polystyrene) of a solid component contained in the photoresist composition by gel permeation chromatography is in the range of 3,000 to 100,000. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【００２４】
【化７】

【００２５】
・（Ｃ）成分
（Ｃ）成分としては、特に限定はなく、従来から化学増幅型のポジ型ホトレジスト組成物の材料として知られている光酸発生剤、例えばスルホニルジアゾメタン系酸発生剤、オニウム塩系酸発生剤、オキシムスルホネート系酸発生剤などを用いることができる。
【００２６】
特にＬＣＤの製造では、ｇ線、ｈ線、ｉ線の共存する紫外線が用いられることがあり、（Ｃ）成分として、このような紫外線の照射を受けたときの酸発生効率の高い化合物が好ましい。また、解像度を向上させるためには、波長の短いｉ線が好ましく利用され、さらに、システムＬＣＤの製造においては、主にｉ線が用いられる傾向があるので、特に、ｉ線露光に対する酸発生効率の高い化合物が好ましい。
【００２７】
（Ｃ）成分として、例えば以下のような化合物が、ｉ線露光に対する酸発生効率が高いことから、好ましく用いられる。
下記一般式（Ｖ）、（ＶＩ）で表されるもの。
【００２８】
【化８】

【００２９】
【化９】

【００３０】
（式中、ｍ’は０又は１；Ｘは１又は２；Ｒ_１は、１又はそれ以上のＣ_１−Ｃ_１２アルキル基が置換していてもよいフェニル基、ヘテロアリール基等、又は、ｍ’が０の場合はさらにＣ_２−Ｃ_６アルコキシカルボニル基、フェノキシカルボニル基、ＣＮ等；Ｒ_１’はＣ_２−Ｃ_１２アルキレン基等；Ｒ_２はＲ_１と同義等；Ｒ_３はＣ_１−Ｃ_１８アルキル基等；Ｒ_３’は、Ｘ＝１のときＲ_３と同義等、Ｘ＝２のときＣ_２−Ｃ_１２アルキレン基、フェニレン基等；Ｒ_４、Ｒ_５は独立に水素原子、ハロゲン、Ｃ_１−Ｃ_６アルキル基等；ＡはＳ、Ｏ、ＮＲ_６等；Ｒ_６は水素原子、フェニル基等を示す。）で表される化合物（ＵＳＰ ６００４７２４）。具体的には、例えば下記式（ＶＩＩ）で表されるチオレン含有オキシムスルホネートなどが挙げられる。
【００３１】
【化１０】

【００３２】
また、下記式（ＶＩＩＩ）
【００３３】
【化１１】

【００３４】
（式中、Ｒ^６、Ｒ^７は、それぞれ炭素数１〜３のアルキル基を示す。）で表されるビス（トリクロロメチル）トリアジン化合物、又は、該化合物（ＶＩＩＩ）と下記式（ＩＸ）
【００３５】
【化１２】

【００３６】
（式中、Ｚは、４−アルコキシフェニル基等を示す。）で表されるビス（トリクロロメチル）トリアジン化合物とを組み合わせたもの（特開平６−２８９６１４号公報、特開平７−１３４４１２号公報）。
【００３７】
トリアジン化合物（ＶＩＩＩ）としては、具体的には、例えば２−［２−（３，４−ジメトキシフェニル）エテニル］−４，６−ビス（トリクロロメチル）−１，３，５−トリアジン、２−［２−（３−メトキシ−４−エトキシフェニル）エテニル］−４，６−ビス（トリクロロメチル）−１，３，５−トリアジン、２−［２−（３−メトキシ−４−プロポキシフェニル）エテニル］−４，６−ビス（トリクロロメチル）−１，３，５−トリアジン、２−［２−（３−エトキシ−４−メトキシフェニル）エテニル］−４，６−ビス（トリクロロメチル）−１，３，５−トリアジン、２−［２−（３，４−ジエトキシフェニル）エテニル］−４，６−ビス（トリクロロメチル）−１，３，５−トリアジン、２−［２−（３−エトキシ−４−プロポキシフェニル）エテニル］−４，６−ビス（トリクロロメチル）−１，３，５−トリアジン、２−［２−（３−プロポキシ−４−メトキシフェニル）エテニル］−４，６−ビス（トリクロロメチル）−１，３，５−トリアジン、２−［２−（３−プロポキシ−４−エトキシフェニル）エテニル］−４，６−ビス（トリクロロメチル）−１，３，５−トリアジン、２−［２−（３，４―ジプロポキシフェニル）エテニル］−４，６−ビス（トリクロロメチル）−，３，５−トリアジンなどを挙げることができる。これらのトリアジン化合物は単独で用いてもよいし、また２種以上を組み合わせて用いてもよい。
【００３８】
一方、上記トリアジン化合物（ＶＩＩＩ）と所望に応じて組み合わせて用いられる上記トリアジン化合物（ＩＸ）としては、例えば２−（４−メトキシフェニル）−４，６−ビス（トリクロロメチル）−１，３，５−トリアジン、２−（４−エトキシフェニル）−４，６−ビス（トリクロロメチル）−１，３，５−トリアジン、２−（４−プロポキシフェニル）−４，６−ビス（トリクロロメチル）−１，３，５−トリアジン、２−（４−ブトキシフェニル）−４，６−ビス（トリクロロメチル）−１，３，５−トリアジン、２−（４−メトキシナフチル）−４，６−ビス（トリクロロメチル）−１，３，５−トリアジン、２−（４−エトキシナフチル）−４，６−ビス（トリクロロメチル）−１，３，５−トリアジン、２−（４−プロポキシナフチル）−４，６−ビス（トリクロロメチル）−１，３，５−トリアジン、２−（４−ブトキシナフチル）−４，６−ビス（トリクロロメチル）−１，３，５−トリアジン、２−（４−メトキシ−６−カルボキシナフチル）−４，６−ビス（トリクロロメチル）−１，３，５−トリアジン、２−（４−メトキシ−６−ヒドロキシナフチル）−４，６−ビス（トリクロロメチル）−１，３，５−トリアジン、２−［２−（２−フリル）エテニル］−４，６−ビス（トリクロロメチル）−１，３，５−トリアジン、２−［２−（５−メチル−２−フリル）エテニル］−４，６−ビス（トリクロロメチル）−１，３，５−トリアジン、２−［２−（５−エチル−２−フリル）エテニル］−４，６−ビス（トリクロロメチル）−１，３，５−トリアジン、２−［２−（５−プロピル−２−フリル）エテニル］−４，６−ビス（トリクロロメチル）−１，３，５−トリアジン、２−［２−（３，５−ジメトキシフェニル）エテニル］−４，６−ビス（トリクロロメチル）−１，３，５−トリアジン、２−［２−（３−メトキシ−５−エトキシフェニル）エテニル］−４，６−ビス（トリクロロメチル）−１，３，５−トリアジン、２−［２−（３−メトキシ−５−プロポキシフェニル）エテニル］−４，６−ビス（トリクロロメチル）−１，３，５−トリアジン、２−［２−（３−エトキシ−５−メトキシフェニル）エテニル］−４，６−ビス（トリクロロメチル）−１，３，５−トリアジン、２−［２−（３，５−ジエトキシフェニル）エテニル］−４，６−ビス（トリクロロメチル）−１，３，５−トリアジン、２−［２−（３−エトキシ−５−プロポキシフェニル）エテニル］−４，６−ビス（トリクロロメチル）−１，３，５−トリアジン、２−［２−（３−プロポキシ−５−メトキシフェニル）エテニル］−４，６−ビス（トリクロロメチル）−１，３，５−トリアジン、２−［２−（３−プロポキシ−５−エトキシフェニル）エテニル］−４，６−ビス（トリクロロメチル）−１，３，５−トリアジン、２−２−（３，５−ジプロポキシフェニル）エテニル］−４，６−ビス（トリクロロメチル）−１，３，５−トリアジン、２−（３，４−メチレンジオキシフェニル）−４，６−ビス（トリクロロメチル）−１，３，５−トリアジン、２−［２−（３，４−メチレンジオキシフェニル）エテニル］−４，６−ビス（トリクロロメチル）−１，３，５−トリアジンなどが挙げられる。これらのトリアジン化合物は１種用いてもよいし、２種以上を組み合わせて用いてもよい。
【００３９】
また、下記式（Ｘ）
【００４０】
【化１３】

【００４１】
（式中、Ａｒは置換又は未置換のフェニル基、ナフチル基；ＲはＣ_１〜Ｃ_９のアルキル基；ｎは２又は３の整数を示す。）で表される化合物を挙げることができる。これらの化合物は単独で用いてもよいし、また２種以上を組み合わせて用いてもよい。以上例示した化合物の中でも、特に、上記式（ＶＩＩ）で表される化合物および下記式（ＸＩ）で表される化合物は、ｉ線に対する酸発生効率に優れるため、好ましく用いられる。
【００４２】
【化１４】

【００４３】
本実施形態において、（Ｃ）成分は１種または２種以上混合して用いることができる。
（Ｃ）成分の配合量は、（Ａ）成分１００質量部に対して、１〜３０質量部、好ましくは１〜２０質量部とされる。
【００４４】
・（Ｄ）成分
本発明の化学増幅型ポジ型ホトレジスト組成物においては、引置き安定性を高めるために、（Ｄ）成分として、塩基性化合物（好ましくはアミン類）を配合することが好ましい。
当該化合物としては、ホトレジスト組成物に対する相容性を有するものであれば良く、特に制限されるものではないが、例えば特開平９−６００１号公報に記載の化合物を挙げることができる。
【００４５】
特に、下記一般式（ＩＩＩ）で表される比較的嵩高い特定の塩基性化合物（ｄ１）を配合することにより、経時的にレジスト組成物中に副生成される酸成分の量を抑制する効果もあり、レジスト組成物の長期保存安定性を向上させることができる。
【００４６】
【化１５】

【００４７】
一般式（ＩＩＩ）においては、Ｘ、Ｙ、Ｚのうちのひとつ以上（好ましくは２以上、最も好ましくは３つ）が、下記（１）〜（４）
（１）炭素数４以上のアルキル基、
（２）炭素数３以上のシクロアルキル基、
（３）フェニル基、
（４）アラルアルキル基
から選ばれる基である。
また、当該Ｘ、Ｙ、Ｚのうち、前記（１）〜（４）ではないものは、
（１’）炭素数３以下のアルキル基、
（２’）水素原子、の中から選ばれる基または原子である。
Ｘ、Ｙ、Ｚは相互に同じでもよいし、異なっていてもよいが、Ｘ、Ｙ、Ｚのうち、２つ以上が前記（１）〜（４）から選ばれる基である場合には、これらに該当する基どうしは同じであることが、効果の安定性の点から、好ましい。
【００４８】
・・（１）炭素数４以上のアルキル基
前記（１）の場合、炭素数が４未満では、経時安定性を向上させることが難しい。炭素数はさらには５以上、特には８以上であることが好ましい。上限値は特に限定しないが、経時安定効果が認められ、また商業的に入手用であるの点から２０以下、特には１５以下とされる。なお、２０を超えると塩基性強度が弱くなり、保存安定性の効果が低下する。
アルキル基は直鎖状、分岐鎖状のいずれでもよい。
具体的には、例えばｎ−デシル基、ｎ−オクチル基、ｎ−ペンチル基等が好ましい。
【００４９】
・・（２）炭素数３以上のシクロアルキル基
当該シクロアルキル基において、特に炭素数４〜８のシクロアルキル基が商業的に入手可能であり、かつ経時安定性を向上させる効果に優れ好ましい。特に炭素数が６であるシクロヘキシル基が好ましい。
【００５０】
・・（４）アラルアルキル基
アラルアルキル基は、一般式、−Ｒ’−Ｐ（Ｒ’はアルキレン基、Ｐは芳香族炭化水素基）で表されるものである。
Ｐとしてはフェニル基、ナフチル基等が挙げられるが、フェニル基が好ましい。
Ｒ’の炭素数は１以上であればよく、好ましくは１〜３である。
アラルアルキル基としては、例えばベンジル基、フェニルエチル基等が好ましい。
【００５１】
なお、Ｘ、Ｙ、Ｚのうち、前記（１）〜（４）ではないものは、前記（１’）、（２’）の中から選ばれる基または原子である。
【００５２】
（１’）は、直鎖または分岐鎖のいずれでもよい。特にメチル基、エチル基が好ましい。
（ｄ１）成分としては、第３級アミンを構成するものが好ましく、Ｘ、Ｙ、Ｚのうち、前記（１）〜（４）でないものは、（１’）の中から選ばれることが好ましい。例えば、具体的には、トリ−ｎ−デシルアミン、メチル−ジ−ｎ−オクチルアミン、トリ−ｎ−ペンチルアミン、Ｎ，Ｎ−ジシクロヘキシルメチルアミン、トリベンジルアミン等が挙げられる。
中でも、トリ−ｎ−デシルアミン、メチル−ジ−ｎ−オクチルアミン、トリ−ｎ−ペンチルアミンから選ばれる１種以上が好ましく、特にトリ−ｎ−デシルアミンが好ましい。
【００５３】
本実施形態において、（Ｄ）成分は１種または２種以上の混合して用いることができる。
（Ｄ）成分は、樹脂固形分１００質量部に対して０．０１〜５．０質量部、特には０．１〜１．０質量部の範囲で配合することが、効果の点から好ましい。
【００５４】
・有機溶剤
本実施形態のホトレジ組成物における有機溶剤としては、化学増幅型のポジ型ホトレジスト組成物に用いられるものであれば、特に限定せずに用いることができる。
例えば、プロピレングリコールモノアルキルエーテルアセテート（例えばプロピレングリコールモノメチルエーテルアセテート（ＰＧＭＥＡ）等）、乳酸エステル（例えば乳酸エチル等）等のエステル系溶剤、アセトン、メチルエチルケトン、シクロヘキサノン、メチルイソアミルケトン、２−ヘプタノン等のケトン類；エチレングリコール、プロピレングリコール、ジエチレングリコール、あるいはこれらのモノメチルエーテル、モノエチルエーテル、モノプロピルエーテル、モノブチルエーテルまたはモノフェニルエーテル等の多価アルコール類およびその誘導体；ジオキサンのような環式エーテル類；等の非エステル系溶剤が挙げられる。なおエステル系溶剤は、有機カルボン酸とアルコールとの反応生成物であることから、遊離酸である有機カルボン酸を含有する。そのため、前記の（Ｄ）成分を配合しないレジスト組成物、または後述の保存安定剤を配合しないレジスト組成物においては、そのような遊離酸を含有しない非エステル系溶剤を選択することが好ましく、特にケトン類（ケトン系の溶剤）は好ましい。その中でも２−へプタノンは、塗膜性、（Ｃ）成分の溶解性の点からも好適である。
【００５５】
なお、エステル系溶剤も非エステル系溶剤も、ともに経時的に分解して酸を副生成する場合があるが、前記（Ｄ）成分の存在下、あるいは後述の保存安定剤の存在下においては、当該分解反応は抑制される。特にエステル系溶剤においてはその効果が顕著であり、当該（Ｄ）成分、保存安定剤の存在下においては、むしろエステル系溶剤が好ましく、特にＰＧＭＥＡは好適である。
なお、上記分解により副生成する酸成分としては、例えば２−ヘプタノンの場合、蟻酸、酢酸、プロピオン酸等を生じることが確認されている。
有機溶剤は１種または２種以上混合して用いることができる。
特に限定するものではないが、有機溶剤は、固形分の濃度が２０〜５０質量％、好ましくは２５〜４５質量％となる配合量で用いると、塗布性の点から好ましい。
【００５６】
本発明の化学増幅型ポジ型ホトレジスト組成物には、この他、必要に応じて以下の様な保存安定剤を配合すると好ましい。
当該保存安定剤としては、溶剤の分解反応を抑制する作用を有するものであれば特に限定されず、例えば、特開昭５８−１９４８３４号公報に記載されているような酸化防止剤を挙げることができる。酸化防止剤としてはフェノール系化合物とアミン系化合物が知られているが、特にフェノール系化合物が好ましく、中でも２，６−ジ（ｔｅｒｔ−ブチル）−ｐ−クレゾール及びその誘導体が、エステル系溶剤、ケトン系溶剤の劣化に対して有効であり、商業的に入手可能、かつ安価であって、さらに保存安定効果に優れる点で好ましい。特にプロピレングリコールモノアルキルエーテルアセテート、２−ヘプタノンに対する劣化防止効果に極めて優れる。
配合量は、樹脂固形分１００質量部に対して０．０１〜３質量部、特には０．１〜１．０質量部の範囲であることが好ましい。
【００５７】
また、本実施形態のホトレジスト組成物には、本発明の目的を損なわない範囲で、必要に応じて相容性のある添加物、例えばレジスト膜の性能などを改良するための付加的樹脂、可塑剤、安定剤、界面活性剤、現像した像をより一層可視的にするための着色料、より増感効果を向上させるための増感剤やハレーション防止用染料、密着性向上剤などの慣用の添加物を含有させることができる。
【００５８】
・ポジ型ホトレジスト組成物の製造方法
本実施形態のポジ型ホトレジスト組成物は、（Ａ）成分、（Ｃ）成分及び必要に応じてその他の成分を、当該ホトレジスト組成物に含まれる固形分の、ゲルパーミエーションクロマトグラフ法によるポリスチレン換算質量平均分子量（Ｍｗ）が３０００〜１０００００、好ましくは５０００〜５００００の範囲内となるように調製し、有機溶剤に溶解させることによって製造することができる。
有機溶剤の使用量は、好ましくは（Ａ）、（Ｃ）成分及び必要に応じて用いられるその他の成分を溶解したときに、均一なポジ型ホトレジスト組成物が得られるように適宜調整される。好ましくは固形分濃度が１０〜５０質量％、さらに好ましくは２０〜３５質量％となる様に用いられる。なお、ポジ型ホトレジスト組成物の固形分は、（Ａ）、（Ｃ）成分及び必要に応じて用いられるその他の成分の合計に相当する。
【００５９】
ポジ型ホトレジスト組成物のＭｗが好適範囲となるように調整する工程を実施する方法としては、例えば、（１）全成分を混合した後のＭｗが上記範囲となるように、混合前に（Ａ）成分に対して分別操作を行うなどして、（Ａ）成分のＭｗを予め適宜の範囲に調整しておく方法、（２）Ｍｗの異なる（Ａ）成分を複数用意し、これを適宜配合して該固形分のＭｗを上記の範囲に調整する方法などがある。
これらの調製方法の中でも、特に上記（２）による調製方法が、レジスト分子量の調整、および感度調整が容易である点でより好ましい。
【００６０】
本実施形態のポジ型ホトレジスト組成物は、該ホトレジスト組成物に含まれる固形分のＭｗが３０００〜１０００００の範囲内となるように調製されており、より好ましいＭｗは５０００〜５００００である。
本実施形態のポジ型ホトレジスト組成物は化学増幅型の機構を示すものであるので、未露光部分と露光部分との現像コントラストが強く、上記Ｍｗの好適な範囲内で良好な解像性およびＤＯＦ特性を得ることができる。
そして、本実施形態のポジ型ホトレジスト組成物の固形分のＭｗを上記の範囲とすることにより、高耐熱性、高解像性、優れたリニアリティおよびＤＯＦ特性を有するとともに、感度も良好なポジ型ホトレジスト組成物が得られる。
該ホトレジスト組成物の固形分のＭｗが上記範囲より小さいと耐熱性、解像性、リニアリティ、およびＤＯＦ特性が不十分となり、上記の範囲を超えると感度の低下が著しくなり、ホトレジスト組成物の塗布性が損なわれるおそれがある。
【００６１】
［第２の実施形態］
・（Ａ）成分
本発明の化学増幅型ポジ型ホトレジスト組成物の第２の実施形態は、（Ａ）成分が（ａ２）アルカリ可溶性樹脂と（Ｂ）下記一般式（Ｉ）で表される化合物との（ａ３）反応生成物を含む。
本実施形態における（ａ２）成分は、ホトレジスト組成物に用いられるアルカリ可溶性樹脂であれば特に制限せずに用いることができるが、フェノール性水酸基を有することが、（Ｂ）成分との反応性の点から好ましい。
（ａ２）成分としては、上記第１の実施形態において（ａ１）成分を構成するアルカリ可溶性樹脂成分として挙げたものを好適に用いることができる。
【００６２】
（ａ２）成分としてノボラック樹脂を用いる場合、そのＭｗは１０００〜５００００、好ましくは１０００〜２００００程度が感度特性の点から好ましい。より好ましいＭｗの範囲は２０００〜１５０００である。上記範囲より小さいと解像性が低下するおそれがあり、上記範囲を超えると塗布性が悪くなる。
なお、（ａ２）成分としてノボラック樹脂を用いる場合には、前述の（Ｄ）成分や保存安定剤を併用することが、レジスト組成物の長期保存安定性の観点から望ましい。
【００６３】
（ａ２）成分としてヒドロキシスチレン系樹脂を用いる場合、ヒドロキシスチレン単位は少なくとも５０〜９９モル％、好ましくは７０〜９０モル％含まれていることが（Ｂ）成分の反応性の点から好ましい。
特にヒドロキシスチレン系樹脂は、ノボラック樹脂に比べ、酸性度をほとんど帯びていない樹脂である。（Ａ）成分の酸性度の強弱は、レジスト組成物の保存安定性に影響を与えるため、保存安定性の良いレジスト組成物を調整する目的においては、ヒドロキシスチレン系の樹脂を選択することが望ましい。中でも、上述のスチレンおよびスチレン誘導体に起因するスチレン構成単位や、アルキル置換スチレン構成単位（以下、両者を併せて「スチレン系構成単位」という）を含有するヒドロキシスチレン系樹脂は、レジスト組成物の感度、耐熱性、およびレジストパターンの形状を改善する効果もある点で好ましい。 スチレン系構成単位の含有量は、（Ｂ）成分との反応性の確保の点、耐熱性向上、感度向上の点から、１〜３０モル％が好ましく、５〜１５モル％がより好ましい。
【００６４】
（ａ２）成分としてヒドロキシスチレン系樹脂を用いる場合、そのＭｗは１０００〜４００００、好ましくは１０００〜８０００、特には２０００〜６０００であることが、耐熱性、高感度化、架橋剤との反応の安定性の点で好ましい。
（ａ２）成分は、１種または２種以上の材料を用いることができる。
【００６５】
・Ｂ成分
（Ｂ）成分は下記一般式（Ｉ）で表される化合物であり、架橋剤として作用するものである。
【００６６】
【化１６】

【００６７】
［式中、Ｒ^１は、置換基を有していてもよい炭素原子数１〜１０のアルキレン基、または下記一般式（ＩＩ）
【００６８】
【化１７】

【００６９】
（式中、Ｒ^４は、置換基を有していてもよい炭素原子数１〜１０のアルキレン基を示し、ｍは０又は１を表す。）
で表される基のいずれかを示す。］
【００７０】
前記一般式（Ｉ）において、Ｒ^１は置換基を有していてもよい、炭素原子数１〜１０の分岐鎖状、直鎖状のアルキレン基、または前記一般式（ＩＩ）で表されるものである。なお、当該アルキレン基は主鎖に酸素結合（エーテル結合）を含んでいても良い。一般式（ＩＩ）中、Ｒ^４も、置換基を有していてもよい、炭素原子数１〜１０の分岐鎖状、直鎖状のアルキレン基であり、当該アルキレン基は、主鎖に酸素結合（エーテル結合）を含んでいても良い。Ｒ^１としては、−Ｃ_４Ｈ_８−、−Ｃ_２Ｈ_４ＯＣ_２Ｈ_４−、−Ｃ_２Ｈ_４ＯＣ_２Ｈ_４ＯＣ_２Ｈ_４−、及び一般式（ＩＩ）で表されるもの等が好ましく、中でも一般式（ＩＩ）で表されるものが好ましく、特にＲ^４の炭素数が１で、ｍが１のものが好ましい。
（Ｂ）成分は、１種または２種以上混合して用いることができる。
【００７１】
・（ａ３）成分
（ａ３）成分は（ａ２）成分と（Ｂ）成分とを反応させて得られる反応生成物であり、アルカリ水溶液に対して難溶性であって酸成分の作用により可溶性となる特性を有する。
（ａ２）成分と（Ｂ）成分とを反応させると、通常（Ｂ）成分の片方の末端のビニル基が（ａ２）成分の、例えば側鎖のフェノール性水酸基に結合した構成単位を備えた反応生成物が得られる。
かかる構成単位の具体例としては、下記一般式（１Ａ）で表される構成単位または下記一般式（２Ａ）で表される構成単位が挙げられる。
また、（ａ２）成分と（Ｂ）成分とを反応させると、（Ｂ）成分の両方の末端のビニル基が（ａ２）成分中の、例えば側鎖の２つのフェノール性水酸基にそれぞれ結合した部分が存在する反応生成物が得られる。かかる構成単位の具体例としては、下記一般式（１Ｂ）で表される分子間架橋部分、または下記一般式（２Ｂ）で表される分子間架橋部分が挙げられる。
なお、通常は（Ｂ）成分の片方の末端のみが結合した構成単位（例えば（１Ａ）（２Ａ））と、両方が結合した部分（例えば、（１Ｂ）（２Ｂ））の両方が存在する反応生成物（ａ３）が得られる。
【００７２】
【化１８】

【００７３】
【化１９】

【００７４】
【化２０】

【００７５】
【化２１】

【００７６】
Ｒ^１は前記と同じであり、Ｒ^２、Ｒ^３は、前記ノボラック樹脂に関する記載の中で説明された、フェノール類、アルデヒド類、ケトン類等から由来される基である。
【００７７】
本発明における（ａ３）成分は、好ましくは酸触媒の実質的な不存在下で、上記（ａ２）成分と上記（Ｂ）成分とを反応させることにより得ることができる。
前記（Ｂ）成分が（ａ２）アルカリ可溶性樹脂の側鎖の水酸基と予め結合していることにより、レジスト塗布液（組成物）の経時変化が抑えられ、感度の経時変化の少ないレジスト材料となる。そして、当該レジスト材料を基板上に塗布し、加熱すると、（ａ２）成分の側鎖のフェノール性水酸基は、前記構成単位（１Ａ）または（２Ａ）の末端ビニル基と反応し、架橋構造が形成される。そして、これにより、レジスト被膜は、レジストパターン形成時に用いられるアルカリ現像液等のアルカリ性水溶液に対して難溶性となる。
そして、この架橋構造を有する（ａ３）成分に、露光によって（Ｃ）成分から発生した酸が作用すると、当該架橋構造が解裂し、（ａ３）成分のアルカリ性水溶液に対する溶解性が増大する。
【００７８】
なお、（ａ２）成分としてノボラック樹脂を選択する場合、（ａ２）成分と（Ｂ）成分との反応においては、酸触媒を用いなくても反応は進行するので、酸触媒を用いることは必須ではなく、むしろ酸成分が反応系中に存在するとレジスト調整後の保存安定性の点で好ましくない。また、（ａ２）成分としてヒドロキシスチレン系樹脂を選択する場合、（ａ２）成分と（Ｂ）成分とを反応させる際に、酸成分濃度を厳密にコントロールする必要があるため、酸成分が不純物として（ａ２）成分中に含まれているのは好ましくない。そのため（Ｂ）成分と反応させる前に、（ａ２）成分に含まれる酸成分を除く操作を厳しく行うことが好ましい。なお、酸成分は、例えばノボラック樹脂の合成時に用いる酸触媒、反応溶媒中に存在する遊離酸等の有機酸であり、ガスクロマトグラフィー等により分析することができる。
酸成分の除去方法としては、公知の方法を挙げることができ、例えばイオン交換樹脂の使用、純水洗い、アルカリによる中和などの方法を適用することができる。
そして、（Ｂ）成分との反応前の（ａ２）成分中の酸成分の濃度は０．１ｐｐｍ以下、特に０．０１ｐｐｍ以下にしておくことが好ましい。
【００７９】
（ａ２）と（Ｂ）成分とを反応させて得られる（ａ３）成分の質量平均分子量は、（ａ２）成分としてノボラック樹脂を選択した場合は、１００００〜７００００、特には２００００〜５００００、（ａ２）成分としてヒドロキシスチレン系樹脂を選択した場合は、３００００〜１５００００、特には４００００〜１０００００であることが耐熱性等の点から好ましい。
【００８０】
（Ｂ）成分は、（ａ２）成分としてノボラック樹脂を選択した場合は、（ａ２）成分に対して１〜１５質量％、好ましくは４〜８質量％の割合で用いられる。１質量％未満では、レジストパターン未露光部の膜減りが大きくなり、レジストパターンのコントラストが低下する傾向があり、１５質量％を超えると現像液（アルカリ水溶液）に対する溶解性が著しく劣る傾向があり、感度が劣る、パターンが解像しない等の問題を発生する恐れがある。なお、（ａ２）成分としてヒドロキシスチレン系樹脂を選択した場合は、（ａ２）成分に対して１〜１５質量％、好ましくは５〜１０質量％の割合で用いられる。
【００８１】
・（Ｃ）成分
本実施形態における（Ｃ）成分に関しては、上記第１の実施形態と同様である。
【００８２】
・（Ｄ）成分
本実施形態における（Ｄ）成分は、上記第１の実施形態における（Ｄ）成分と同様の構成とすることができる。特に、本実施形態においては、（Ｄ）成分として前記（ｄ１）を用いることが好ましい。
【００８３】
・有機溶媒
本実施形態における有機溶媒は、上記第１の実施形態における有機溶媒と同様のものを用いることができる。
【００８４】
有機溶剤は１種または２種以上混合して用いることができる。
特に限定するものではないが、有機溶剤は、固形分の濃度が２０〜５０質量％、好ましくは２５〜４５質量％となる配合量で用いると、塗布性の点から好ましい。
また、本実施形態においても、上記第１の実施形態と同様の保存安定性を必要に応じて用いることができる。
【００８５】
また、本実施形態のホトレジスト組成物にも、本発明の目的を損なわない範囲で、前記第１の実施形態と同様のその他の成分を含有させることができる。
【００８６】
・ポジ型ホトレジスト組成物の製造方法
本実施形態のホトレジスト組成物は、上記第１の実施形態と同様にして製造することができる。
【００８７】
本実施形態のポジ型ホトレジスト組成物は、該ホトレジスト組成物に含まれる固形分のＭｗが３０００〜１０００００の範囲内となるように調製されており、より好ましいＭｗは１００００〜８００００である。
本実施形態のホトレジスト組成物によれば、上記第１の実施形態と同様の作用効果が得られるほか、当該レジスト材料を基板上に塗布し、加熱すると、上述の通り架橋構造を形成するので、特に耐熱性に優れたレジストパターンを得ることができ、膜減りが防止される。
【００８８】
［第３の実施形態］
・（Ａ）（Ｂ）成分
本発明の化学増幅型ポジ型ホトレジスト組成物の第３の実施形態は、（Ａ）成分が（ａ２）アルカリ可溶性樹脂を含むとともに、さらに前記一般式（Ｉ）で表される（Ｂ）成分を含んでいる。
本実施形態における（ａ２）成分および（Ｂ）成分は、上記第２の実施形態と同様の構成とすることができ、本実施形態が第２の実施形態と大きく異なる点は（ａ２）成分と（Ｂ）成分とが反応していない状態で（Ａ）成分に含まれている点である。
本実施形態において、（Ｂ）成分は、（ａ２）成分としてノボラック樹脂を選択した場合は、（ａ２）成分に対して１〜５０質量％、好ましくは５〜３５質量％の割合で用いられる。１質量％未満では、レジストパターン未露光部の膜減りが大きくなり、レジストパターンのコントラストが低下する傾向があり、５０質量％を超えると現像液（アルカリ水溶液）に対する溶解性が著しく劣る傾向があり、感度が劣る、パターンが解像しない等の問題を発生する恐れがある。なお、（ａ２）成分としてヒドロキシスチレン系樹脂を選択した場合は、（ａ２）成分に対して１〜５０質量％、好ましくは５〜４０質量％の割合で用いられる。
【００８９】
・（Ｃ）成分
本実施形態における（Ｃ）成分に関しては、上記第１の実施形態と同様である。
・（Ｄ）成分
本実施形態における（Ｄ）成分は、上記第２の実施形態と同様である。
・有機溶媒
本実施形態における有機溶媒は、上記第１の実施形態と同様である。
【００９０】
また、本実施形態のホトレジスト組成物にも、本発明の目的を損なわない範囲で、前記第１の実施形態と同様のその他の成分を含有させることができる。
【００９１】
・ポジ型ホトレジスト組成物の製造方法
本実施形態のホトレジスト組成物は、上記第１の実施形態と同様にして製造することができる。
【００９２】
本実施形態のポジ型ホトレジスト組成物は、該ホトレジスト組成物に含まれる固形分のＭｗが３０００〜１０００００の範囲内となるように調製されており、より好ましいＭｗは４０００〜３００００である。
本実施形態のホトレジスト組成物によれば、上記第２の実施形態と同様の作用効果が得られる。
【００９３】
［レジストパターンの形成方法］
以下に、本発明のホトレジスト組成物を用いてシステムＬＣＤを製造する方法の好適な一例を示す。
まず、（Ａ）成分および（Ｃ）成分、並びに必要に応じて添加される各種成分を溶剤に溶解し、これをスピンナー等で基板に塗布して塗膜を形成する。基板としてはガラス基板が好ましい。このガラス基板としては、通常アモルファスシリカが用いられるが、システムＬＣＤの分野においては、低温ポリシリコン等が好ましいとされる。また、５００ｍｍ×６００ｍｍ以上、特には５５０ｍｍ×６５０ｍｍ以上の大型の基板を用いることができる。
【００９４】
次いで、この塗膜が形成されたガラス基板を例えば９０〜１４０℃で加熱処理（プリベーク）して残存溶媒を除去し、レジスト被膜を形成する。プリベーク方法としては、ホットプレートと基板の間に隙間を持たせるプロキシミティベークを行うことが好ましい。
次いで、上記レジスト被膜に対し、集積回路用のマスクパターンと液晶ディスプレイ部分用のマスクパターンの双方が描かれたマスクを用いて選択的露光を行う。
ここで用いる光源としては、微細なパターンを形成するためにｉ線（３６５ｎｍ）を用いることが好ましい。また、この露光で採用する露光プロセスは、ＮＡが０．３以下、好ましくは０．２以下、より好ましくは０．１５以下の低ＮＡ条件の露光プロセスであることが好ましい。低ＮＡ条件での露光プロセスを採用することにより、一回の露光面積を広くとることができ、スループットの向上が図れる。
【００９５】
次いで、選択的露光後のレジスト被膜に対し、加熱処理（ポストエクスポージャーベーク：ＰＥＢ）を施す。ＰＥＢ方法としては、ホットプレートと基板の間に隙間を持たせるプロキシミティベーク、隙間を持たせないダイレクトベークが挙げられ、基板の反りを生じさせることをなく、ＰＥＢによる拡散効果を得るために、プロキシミティベークを行った後、ダイレクトベークを行う方法が好ましい。なお、加熱温度は９０〜１５０℃、特には１００〜１４０℃が好ましい。
上記ＰＥＢ後のレジスト被膜に対し、現像液、例えば１〜１０質量％テトラメチルアンモニウムヒドロキシド水溶液のようなアルカリ水溶液を用いた現像処理を施すと、露光部分が溶解除去されて、基板上に集積回路用のレジストパターンと液晶ディスプレイ部分用のレジストパターンが同時に形成される。
次いで、レジストパターン表面に残った現像液を純水などのリンス液で洗い落とすことによりレジストパターンを形成できる。
【００９６】
上記選択的露光を行う工程において、上記マスクとして、２．０μｍ以下のレジストパターン形成用マスクパターンと、２．０μｍ超のレジストパターン形成用マスクパターンの双方が描かれたマスクを用いることが好ましい。
本発明の化学増幅型ポジ型ホトレジスト組成物は、リニアリティに優れているので、マスクパターンのラフなパターンと微細なパターンの両方を忠実に再現したレジストパターンが得られる。したがって、基板上に、パターン寸法２．０μｍ以下の集積回路用のレジストパターンと、２．０μｍ超の液晶ディスプレイ部分用のレジストパターンを同時に形成することができる。
【００９７】
【実施例】
以下本発明を、実施例を示して詳しく説明する。
次に実施例を示して本発明をさらに詳細に説明するが、本発明は以下の実施例に限定されるものではない。
【００９８】
［ポジ型ホトレジスト組成物の評価方法］
下記の実施例または比較例のポジ型ホトレジスト組成物について下記の諸物性（１）〜（５）の評価方法を以下に示す。
（１）感度評価：ポジ型ホトレジスト組成物を大型基板用レジスト塗布装置（装置名：ＴＲ３６０００東京応化工業（株）製）を用いてＴｉ膜が形成されたガラス基板（５５０ｍｍ×６５０ｍｍ）上に塗布したのち、１４０℃、９０秒間の加熱条件で、約１ｍｍの間隔をあけたプロキシミティベークによりプリベークを行って、膜厚１．５μｍのレジスト被膜を形成した。
次いで１．５μｍＬ＆Ｓのレジストパターンと３．０μｍＬ＆Ｓのレジストパターンを再現するためのマスクパターンが同時に描かれたテストチャートマスク（レチクル）を介して、ｉ線露光装置（装置名：ＦＸ−７０２Ｊ、ニコン社製；ＮＡ＝０．１４）を用いて、１．５μｍＬ＆Ｓを忠実に再現することのできる露光量（Ｅｏｐ露光量）にて選択的露光を行った。
次いで、１１０℃、９０秒間の条件で、０．５ｍｍの間隔をあけたプロキシミティベークにより、ＰＥＢを施した。
次いで、２３℃、２．３８質量％ＴＭＡＨ水溶液用いて６０秒間の現像処理を行った後、純水で３０秒間リンスし、スピン乾燥した。
感度評価の指標として、１．５μｍＬ＆Ｓのレジストパターンを忠実に再現できる露光量（Ｅｏｐ、単位：ｍＪ）を用いた。
【００９９】
（２）ＤＯＦ特性評価：上記Ｅｏｐ露光量において、焦点を適宜上下にずらし、１．５μｍＬ＆Ｓが±１０％の寸法変化率の範囲内で得られた焦点深度（ＤＯＦ）の幅をμｍ単位で求めた。
（３）耐熱性評価：上記Ｅｏｐ露光量において、１．５μｍＬ＆Ｓが描かれた基板を、１４０℃に設定されたホットプレート上に３００秒間静置した後、断面形状を観察した。その結果、１．５μｍＬ＆Ｓの寸法変化率が±３％以内であったものを○、３〜５％または−５〜−３％の範囲内であったものを△、±５％を超えたものを×として表した。
（４）解像性評価： 上記Ｅｏｐ露光量における限界解像度を求めた。
（５）リニアリティ評価：上記Ｅｏｐ露光量で得られる３．０μｍＬ＆Ｓのレジストパターンの断面形状をＳＥＭ（走査型電子顕微鏡）写真にて観察し、３．０μｍＬ＆Ｓのレジストパターンの再現性を評価した。３．０μｍＬ＆Ｓの寸法変化率が±１０％以内であったものを○、±１０％を超えたものを×として表した。
【０１００】
以下の実施例において、（Ａ）成分として下記のものを用いた。
・（ａ１）成分
質量平均分子量８０００のポリヒドロキシスチレンの１５重量％溶液［溶媒＝２−ヘプタノン］２６７ｇにトリエチルアミン１７．８ｇ、およびジ−ｔｅｒｔ−ブチル−ジ−カルボネート３８．２５ｇを添加し、２２℃で２時間反応を行った。次いで、反応液を１．５重量％酢酸水溶液５００ｍｌ中に注ぎ、静置し、有機溶媒層（上層）を、デカンテーションにより取り出した。その後、純水５００ｍｌを用いた洗浄操作を２回行った後、有機溶媒を減圧除去してフェノール性水酸基の３５％がｔ−ブトキシカルボニル基で保護されたポリヒドロキシスチレン３５ｇを得た。
【０１０１】
・（ａ２）成分
スチレン構成単位／ヒドロキシスチレン構成単位＝１５／８５、Ｍｗ５０００のポリヒドロキシスチレン系樹脂。
・（ａ３）成分
メチルイソブチルケトン（ＭＩＢＫ）溶剤に濃度３０質量％になるように上記（ａ２）成分（Ｍｗ：５０００）を攪拌溶解し、内温１００〜１１０℃にした後、下記［化２２］で表される化合物（（Ｂ）成分）を、樹脂固形分１００質量部に対して８質量部に相当する量だけ滴下した。２４時間反応後、１２時間以上室温にて後攪拌を行い、その後、ＭＩＢＫから２−ヘプタノンに溶剤置換を行った。
得られた（ａ３）成分のＭｗは５５０００であった。
【０１０２】
【化２２】

【０１０３】
（実施例１）
上記（ａ１）成分（Ｍｗ：８０００）：１００質量部
（Ｃ）成分［上記式（ＸＩ）の化合物］：３質量部
（Ｄ）成分［トリ−ｎ−デシルアミン］：０．２質量部
上記各種成分をＰＧＭＥＡに溶解し、さらに界面活性剤としてＸＲ−１０４（大日本インキ社製）を５００ｐｐｍ配合し、３５質量％濃度の溶液に調整した後、これを孔径０．２μｍのメンブランフィルターを用いてろ過し、ホトレジスト組成物を調製した。得られたホトレジスト組成物のＭｗは、７５００であった。
このホトレジスト組成物について前記（１）〜（５）の物性を評価した。その結果を下記表１に示す。
【０１０４】
（実施例２）
上記（ａ３）成分、（Ｍｗ：５５０００）：１００質量部
（Ｃ）成分［上記式（ＸＩ）の化合物］：３質量部
（Ｄ）成分［トリ−ｎ−デシルアミン］：０．２質量部
上記各種成分をＰＧＭＥＡに溶解し、さらに界面活性剤としてＸＲ−１０４（大日本インキ社製）を５００ｐｐｍ配合し、３５質量％濃度の溶液に調整した後、これを孔径０．２μｍのメンブランフィルターを用いてろ過し、ホトレジスト組成物を調製した。得られたホトレジスト組成物のＭｗは、５００００であった。
このホトレジスト組成物について前記（１）〜（５）の物性を評価した。その結果を下記表１に示す。
【０１０５】
（実施例３）
上記（ａ２）成分、（Ｍｗ：５０００）：１００質量部
（Ｂ）成分［上記式（［化２２］）の化合物］：７質量部
（Ｃ）成分［上記式（ＸＩ）の化合物］：３質量部
（Ｄ）成分［トリ−ｎ−デシルアミン］：０．２質量部
上記各種成分をＰＧＭＥＡに溶解し、さらに界面活性剤としてＸＲ−１０４（大日本インキ社製）を５００ｐｐｍ配合し、３５質量％濃度の溶液に調整した後、これを孔径０．２μｍのメンブランフィルターを用いてろ過し、ホトレジスト組成物を調製した。得られたホトレジスト組成物のＭｗは、４５００であった。
このホトレジスト組成物について前記（１）〜（５）の物性を評価した。その結果を下記表１に示す。
【０１０６】
（比較例１）
実施例１において、上記（ａ１）成分（Ｍｗ：８０００）の代わりに、フェノール性水酸基の３５％がｔ−ブトキシカルボニル基で保護されたポリヒドロキシスチレン（Ｍｗ：１５００）を用いた以外は実施例１と同様にしてホトレジスト組成物を調製した。得られたホトレジスト組成物のＭｗは、１０００であった。このホトレジスト組成物について前記（１）〜（５）の物性を評価した。その結果を下記表１に示す。
【０１０７】
（比較例２）
実施例２において、上記（ａ３）成分（Ｍｗ：５５０００）の代わりに、スチレン構成単位／ヒドロキシスチレン構成単位＝１５／８５、Ｍｗ１５００のポリヒドロキシスチレン系樹脂固形分１００質量部に対して、上記式［化２２］で表される化合物１質量部を配合して得られた樹脂（Ｍｗ＝２５００）を用いた以外は実施例１と同様にしてホトレジスト組成物を調製した。得られたホトレジスト組成物のＭｗは、２０００であった。
このホトレジスト組成物について前記（１）〜（５）の物性を評価した。その結果を下記表１に示す。
【０１０８】
（比較例３）
実施例３において、上記（ａ２）成分（Ｍｗ：５０００）の代わりに、スチレン構成単位／ヒドロキシスチレン構成単位＝１５／８５、Ｍｗ１５００のポリヒドロキシスチレン系樹脂を用いた以外は実施例３と同様にしてホトレジスト組成物を調製した。得られたホトレジスト組成物のＭｗは、１０００であった。
【０１０９】
（比較例４）
実施例３において、上記（ａ２）成分（Ｍｗ：５０００）の代わりに、スチレン構成単位／ヒドロキシスチレン構成単位＝１５／８５、Ｍｗ１５００００のポリヒドロキシスチレン系樹脂を用いた以外は実施例３と同様にしてホトレジスト組成物を調製した。得られたホトレジスト組成物のＭｗは、１４５０００であった。
【０１１０】
【表１】

【０１１１】
【発明の効果】
以上説明したように本発明の化学増幅型ポジ型ホトレジスト組成物は、感度が良好で、耐熱性に優れ、高解像度が得られるので、システムＬＣＤ製造用に好適であり、スループットを向上させることができる。
また、リニアリティに優れているので、１つの基板上に、ラフなパターンと微細なパターンとを同一露光条件で形成できる。したがって、システムＬＣＤのディスプレイ部分と、それよりも微細な集積回路部分のレジストパターンも、同時に高解像度で得ることができるので、システムＬＣＤの製造用として好適である。
また、システムＬＣＤ製造用のポジ型ホトレジスト組成物においては、焦点深度（ＤＯＦ）の幅がある程度大きいことが、製造効率、製造条件の制御の容易性等の点から重要であるが、本発明の化学増幅型ポジ型ホトレジスト組成物は、システムＬＣＤ用として実用可能な焦点深度の幅（例えば１５μｍ以上）を実現することができる。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a positive photoresist composition for manufacturing a substrate having an integrated circuit and a liquid crystal display portion formed on one substrate, and a method of forming a resist pattern using the same.
[0002]
[Prior art]
Until now, as a resist material in the field of liquid crystal display element manufacturing using a glass substrate, it is suitable for ghi-line exposure, it is relatively inexpensive, has good sensitivity, good resolution, and can form a resist pattern excellent in shape. A positive photoresist composition using a novolak resin as an alkali-soluble resin and a quinonediazide group-containing compound as a photosensitive component has been widely used and reported (Patent Documents 1 to 4 below).
[0003]
Patent Document 5 discloses a chemically amplified photoresist composition containing a linear polymer having an acid component and a hydroxyl group, a PAG, and a compound having at least two specific enol ether groups. And a specific compound having been crosslinked by heat.
Further, Patent Document 6 below discloses that a linear polymer having an acid group, a PAG, and a compound having at least two specific enol ether groups are contained, and the linear polymer and the specific compound are crosslinked by heat. Are described.
[0004]
[Patent Document 1]
JP 2000-131835 A
[Patent Document 2]
JP 2001-75272 A
[Patent Document 3]
JP-A-2000-181555
[Patent Document 4]
JP-A-2000-112120
[Patent Document 5]
JP-A-6-148889
[Patent Document 6]
JP-A-6-230574
[0005]
At present, as a next-generation LCD, a so-called "system" in which an integrated circuit portion such as a driver, a DAC (digital-to-analog converter), an image processor, a video controller, and a RAM is formed simultaneously with a display portion on a single glass substrate. Technology development for high-performance LCDs called "LCDs" has been actively conducted (Semiconductor FPD World 2001.1, pp.50-67).
Hereinafter, in this specification, such a substrate in which an integrated circuit and a liquid crystal display portion are formed on one substrate is referred to as a system LCD for convenience.
[0006]
In such a system LCD, low-temperature polysilicon formed by a low-temperature process at 600 ° C. or lower is particularly preferable in place of amorphous silicon because of its lower electric resistance and higher mobility than amorphous silicon. Have been.
Therefore, development of a photoresist composition suitable for manufacturing a system LCD using low-temperature polysilicon has been desired, but there has been no report on a resist material for a system LCD.
Patent Documents 5 and 6 relating to the chemically amplified photoresist composition also do not disclose a system LCD.
[0007]
In order to manufacture a TFT made of low-temperature polysilicon, a polysilicon film is formed on a glass substrate by a low-temperature process, and then P or B is implanted into the low-temperature polysilicon film. There is a need to implant high concentrations of impurities.
This implantation step is performed under a high vacuum condition in a state in which a resist pattern is formed on a low-temperature polysilicon glass substrate in which a low-temperature polysilicon film is formed on a glass substrate. When the resist pattern on the substrate is heated by the action, there is a problem that the shape of the resist pattern changes, or a certain component in the resist pattern is gasified to lower the degree of vacuum in the processing chamber.
[0008]
As a means to solve this problem, it is effective to perform a heat treatment step called “post bake” before the implantation step. However, this post bake is performed under a temperature condition close to the temperature heated at the time of implantation, for example. Since the heat treatment is performed at a high temperature of 200 ° C. or more, it is essential to form a highly heat-resistant resist pattern whose pattern shape does not change during the heat treatment.
Therefore, in order to realize the production of the system LCD, it is required that the photoresist composition used therein has good heat resistance.
[0009]
In the system LCD, for example, the pattern size of the display portion is about 2 to 10 μm, while the integrated circuit portion is formed with a fine size of about 0.5 to 2.0 μm. Therefore, a photoresist composition for manufacturing a system LCD is required to have a capability (linearity) capable of simultaneously forming a fine pattern and a rough pattern with good shape (linearity), and have a higher resolution than a conventional resist material for LCD manufacturing. It is strictly required that the fine pattern has a good depth of focus (DOF) characteristic.
[0010]
However, in the field of manufacturing liquid crystal devices, a decrease in the sensitivity of the resist material causes a serious decrease in throughput, and thus it is not preferable. It is desirable to improve the above-mentioned characteristics without causing a decrease in sensitivity.
[0011]
[Problems to be solved by the invention]
The present invention satisfies the heat resistance, resolution, linearity, and DOF characteristics required for manufacturing a system LCD in which an integrated circuit and a liquid crystal display portion are formed on one substrate, and has good sensitivity. It is an object to provide a photoresist composition and a method for forming a resist pattern using the same.
[0012]
[Means for Solving the Problems]
As a result of diligent studies, the present inventors have found that the above-mentioned problems can be solved by the following means, and have completed the present invention.
That is, the chemically amplified positive photoresist composition of the present invention is a chemically amplified positive photoresist composition for manufacturing a substrate in which an integrated circuit and a liquid crystal display portion are formed on one substrate, wherein the resin (A) A component that generates an acid component upon irradiation with radiation (C), and an organic solvent, and has a property of increasing solubility in an aqueous alkali solution by the action of the acid component generated from the component (C); The solid content contained in the photoresist composition has a mass average molecular weight (Mw) in terms of polystyrene determined by gel permeation chromatography within a range of 3,000 to 100,000.
[0013]
In addition, the present invention provides (1) a step of applying the above-mentioned positive photoresist composition on a substrate to form a coating film, and (2) heat-treating (pre-baking) the substrate on which the coating film has been formed to form a coating on the substrate. (3) using a mask on which both a mask pattern for forming a resist pattern of 2.0 μm or less and a mask pattern for forming a resist pattern of more than 2.0 μm are drawn on the resist film; (4) performing a heat treatment (post-exposure bake) on the resist film after the selective exposure, and (5) using an aqueous alkali solution on the resist film after the heat treatment. And a resist pattern for an integrated circuit having a pattern size of 2.0 μm or less and a resist pattern for a liquid crystal display portion having a pattern size of more than 2.0 μm. It provides a method of forming a resist pattern comprising the steps of forming a over down simultaneously.
[0014]
As the value of the mass average molecular weight (Mw) of the photoresist composition in this specification, a value measured using the following GPC system is used.
Apparatus name: SYSTEM 11 (product name, manufactured by Showa Denko KK)
Pre-column: KF-G (product name, manufactured by Shodex)
Column: KF-805, KF-803, KF-802 (product name, manufactured by Shodex)
Detector: UV41 (product name, manufactured by Shodex), measured at 280 nm.
Solvent, etc .: Measured at 35 ° C. by flowing tetrahydrofuran at a flow rate of 1.0 ml / min.
Measurement sample preparation method: A photoresist composition to be measured is adjusted so that the solid content concentration is 30% by mass, and this is diluted with tetrahydrofuran to prepare a measurement sample having a solid content concentration of 0.1% by mass. . Twenty microliters of the measurement sample are injected into the above device to perform measurement.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
[First Embodiment]
・ A component
In the first embodiment of the chemically amplified positive photoresist composition of the present invention, the component (A) is (a1) an alkali poorly soluble or partially alkaline phenolic hydroxyl group protected by an acid dissociable, dissolution inhibiting group. Contains an insoluble resin.
The hardly soluble or insoluble alkali resin component constituting the component (a1) can be generally synthesized by an addition reaction between an alkali-soluble resin and a compound corresponding to the acid dissociable, dissolution inhibiting group. It can also be obtained by a copolymerization reaction between a monomer having a hydrophilic hydroxyl group and a monomer having an acid dissociable, dissolution inhibiting group. The alkali-soluble resin is not particularly limited, and can be arbitrarily selected from those usually used as a film-forming substance in a positive photoresist composition, and is preferably an aromatic hydroxy compound and an aldehyde or Novolak resins, polyhydroxystyrenes and derivatives thereof obtained by a condensation reaction with ketones can be mentioned.
[0016]
Examples of the aromatic hydroxy compound include phenol; cresols such as m-cresol, p-cresol and o-cresol; 2,3-xylenol, 2,5-xylenol, 3,5-xylenol, 3,4-xylenol Xylenols such as m-ethylphenol, p-ethylphenol, o-ethylphenol, 2,3,5-trimethylphenol, 2,3,5-triethylphenol, 4-tert-butylphenol, 3-tert-butylphenol, Alkylphenols such as 2-tert-butylphenol, 2-tert-butyl-4-methylphenol, 2-tert-butyl-5-methylphenol; p-methoxyphenol, m-methoxyphenol, p-ethoxyphenol, m-ethoxy Phenol, p- Alkoxyphenols such as loxyphenol and m-propoxyphenol; isopropenylphenol such as o-isopropenylphenol, p-isopropenylphenol, 2-methyl-4-isopropenylphenol and 2-ethyl-4-isopropenylphenol And arylphenols such as phenylphenol; and polyhydroxyphenols such as 4,4'-dihydroxybiphenyl, bisphenol A, resorcinol, hydroquinone, and pyrogallol. These may be used alone or in combination of two or more.
[0017]
Examples of the aldehydes include formaldehyde, paraformaldehyde, trioxane, acetaldehyde, propionaldehyde, butyraldehyde, trimethylacetaldehyde, acrolein, crotonaldehyde, cyclohexanealdehyde, furfural, furylacrolein, benzaldehyde, terephthalaldehyde, phenylacetaldehyde, α-phenylpropyl Aldehyde, β-phenylpropyl aldehyde, o-hydroxybenzaldehyde, m-hydroxybenzaldehyde, p-hydroxybenzaldehyde, o-methylbenzaldehyde, m-methylbenzaldehyde, p-methylbenzaldehyde, o-chlorobenzaldehyde, m-chlorobenzaldehyde, p- Chlorobenzaldehyde, cinnamic acid Aldehyde and the like. These may be used alone or in combination of two or more.
Among these aldehydes, formaldehyde is preferable in terms of availability, but in particular, in order to improve heat resistance, it is preferable to use a combination of hydroxybenzaldehyde and formaldehyde.
[0018]
Examples of the ketones include acetone, methyl ethyl ketone, diethyl ketone, diphenyl ketone, and the like. These may be used alone or in combination of two or more. Furthermore, aldehydes and ketones may be used in an appropriate combination.
[0019]
The condensation reaction product of the aromatic hydroxy compound with aldehydes or ketones can be produced by a known method in the presence of an acidic catalyst. Hydrochloric acid, sulfuric acid, formic acid, oxalic acid, p-toluenesulfonic acid and the like can be used as the acidic catalyst at that time.
[0020]
Examples of the polyhydroxystyrene and its derivative include a homopolymer of vinylphenol and a copolymer of vinylphenol with a comonomer copolymerizable therewith. Examples of the comonomer include styrene derivatives such as acrylic acid derivatives, acrylonitrile, methacrylic acid derivatives, methacrylonitrile, styrene, α-methylstyrene, p-methylstyrene, o-methylstyrene, p-methoxystyrene, and p-chlorostyrene. Is mentioned.
[0021]
Among these, preferred resins as the component (a1) include novolak resins, polyhydroxystyrene, and hydroxystyrene-styrene copolymer.
The preferred range of the mass average molecular weight (Mw) of the alkali-soluble resin (a1) in the present embodiment before being protected by the acid dissociable, dissolution inhibiting group is 1,000 to 200,000, preferably 2,000 to 50,000, more preferably Is 3000 to 30000. If the Mw of the component (a1) is smaller than the above range, the resolution may be reduced.
[0022]
In the present embodiment, at least a part of all the phenolic hydroxyl groups in the component (a1) is protected by a group that is decomposed by an acid-catalyzed reaction to change into alkali-soluble, that is, a so-called acid dissociable, dissolution inhibiting group.
The acid dissociable, dissolution inhibiting group only needs to be one dissociated by an acid generated from the component (C) described later, and examples thereof include a 1-ethoxymethyl group, a 1-ethoxyethyl group, a 1-propoxymethyl group, -Alkoxyalkyl groups such as -propoxyethyl group, 1-n-butoxymethyl group, 1-iso-butoxymethyl group, 1-tert-butoxymethyl group; t-butoxycarbonyl group, t-butoxycarbonylmethyl group, t-butoxy Alkoxycarbonylalkyl groups such as carbonylethyl groups; tetrahydrofuranyl groups; tetrahydropyranyl groups; linear or branched acetal groups; cyclic acetal groups; trialkylsilyl groups such as trimethylsilyl, triethylsilyl, and triphenylsilyl groups Is mentioned.
Among them, an ethylvinyl group (ethoxyethyl group) represented by the following chemical formula (IV-1) and a t-butoxycarbonyl group represented by the following chemical formula (IV-2) provide a photoresist composition having excellent resolution. And an ethylvinyl group is particularly preferable.
[0023]
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[0024]
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[0025]
・ (C) component
The component (C) is not particularly limited, and a photoacid generator conventionally known as a material for a chemically amplified positive photoresist composition, for example, a sulfonyldiazomethane-based acid generator, an onium salt-based acid generator, An oxime sulfonate-based acid generator can be used.
[0026]
In particular, in the production of LCDs, ultraviolet rays in which g-rays, h-rays, and i-rays coexist may be used. As the component (C), compounds having high acid generation efficiency when irradiated with such ultraviolet rays are preferable. . Further, in order to improve the resolution, i-line having a short wavelength is preferably used. Further, in the production of a system LCD, the i-line tends to be mainly used. Are preferred.
[0027]
As the component (C), for example, the following compounds are preferably used because of high acid generation efficiency with respect to i-line exposure.
Those represented by the following general formulas (V) and (VI).
[0028]
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[0029]
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[0030]
(Wherein m ′ is 0 or 1; X is 1 or 2; R ₁ Is one or more C ₁ -C ₁₂ A phenyl group, a heteroaryl group or the like which may be substituted by an alkyl group; ₂ -C ₆ An alkoxycarbonyl group, a phenoxycarbonyl group, CN, etc .; ₁ 'Is C ₂ -C ₁₂ An alkylene group or the like; R ₂ Is R ₁ Synonymous with; R ₃ Is C ₁ -C ₁₈ Alkyl group, etc .; R ₃ 'Is R when X = 1 ₃ When X = 2, C is equivalent to ₂ -C ₁₂ Alkylene group, phenylene group, etc .; ₄ , R ₅ Is independently a hydrogen atom, halogen, C ₁ -C ₆ A is S, O, NR ₆ Etc .; R ₆ Represents a hydrogen atom, a phenyl group or the like. (USP 600004724). Specific examples include thiolen-containing oxime sulfonates represented by the following formula (VII).
[0031]
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[0032]
Further, the following formula (VIII)
[0033]
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[0034]
(Where R ⁶ , R ⁷ Represents an alkyl group having 1 to 3 carbon atoms. Or a bis (trichloromethyl) triazine compound represented by the formula (IX):
[0035]
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[0036]
(Wherein, Z represents a 4-alkoxyphenyl group or the like) (JP-A-6-289614 and JP-A-7-134412) in combination with a bis (trichloromethyl) triazine compound represented by the following formula: .
[0037]
Specific examples of the triazine compound (VIII) include, for example, 2- [2- (3,4-dimethoxyphenyl) ethenyl] -4,6-bis (trichloromethyl) -1,3,5-triazine, [2- (3-methoxy-4-ethoxyphenyl) ethenyl] -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- [2- (3-methoxy-4-propoxyphenyl) ethenyl ] -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- [2- (3-ethoxy-4-methoxyphenyl) ethenyl] -4,6-bis (trichloromethyl) -1, 3,5-triazine, 2- [2- (3,4-diethoxyphenyl) ethenyl] -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- [2- (3-ethoxy -4-Pro [Xyphenyl) ethenyl] -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- [2- (3-propoxy-4-methoxyphenyl) ethenyl] -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- [2- (3-propoxy-4-ethoxyphenyl) ethenyl] -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- [2- (3,4-dipropoxyphenyl) ethenyl] -4,6-bis (trichloromethyl)-, 3,5-triazine. These triazine compounds may be used alone or in combination of two or more.
[0038]
On the other hand, as the triazine compound (IX) used in combination with the triazine compound (VIII) as required, for example, 2- (4-methoxyphenyl) -4,6-bis (trichloromethyl) -1,3,3 5-triazine, 2- (4-ethoxyphenyl) -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- (4-propoxyphenyl) -4,6-bis (trichloromethyl)- 1,3,5-triazine, 2- (4-butoxyphenyl) -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- (4-methoxynaphthyl) -4,6-bis ( Trichloromethyl) -1,3,5-triazine, 2- (4-ethoxynaphthyl) -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- (4-propoxy Naphthyl) -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- (4-butoxynaphthyl) -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- (4-methoxy-6-carboxynaphthyl) -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- (4-methoxy-6-hydroxynaphthyl) -4,6-bis (trichloromethyl ) -1,3,5-Triazine, 2- [2- (2-furyl) ethenyl] -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- [2- (5-methyl -2-furyl) ethenyl] -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- [2- (5-ethyl-2-furyl) ethenyl] -4,6-bis (trichloromethyl Methyl) -1,3,5-tri Gin, 2- [2- (5-propyl-2-furyl) ethenyl] -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- [2- (3,5-dimethoxyphenyl) Ethenyl] -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- [2- (3-methoxy-5-ethoxyphenyl) ethenyl] -4,6-bis (trichloromethyl) -1 , 3,5-triazine, 2- [2- (3-methoxy-5-propoxyphenyl) ethenyl] -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- [2- (3 -Ethoxy-5-methoxyphenyl) ethenyl] -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- [2- (3,5-diethoxyphenyl) ethenyl] -4,6- Bis (trichloromethyl)- 1,3,5-triazine, 2- [2- (3-ethoxy-5-propoxyphenyl) ethenyl] -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- [2- ( 3-propoxy-5-methoxyphenyl) ethenyl] -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- [2- (3-propoxy-5-ethoxyphenyl) ethenyl] -4, 6-bis (trichloromethyl) -1,3,5-triazine, 2-2 (3,5-dipropoxyphenyl) ethenyl] -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- (3,4-methylenedioxyphenyl) -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- [2- (3,4-methylenedioxyphenyl) ethenyl] -4 , 6-bis ( Rikuroromechiru) -1,3,5-triazine. One of these triazine compounds may be used, or two or more thereof may be used in combination.
[0039]
Also, the following formula (X)
[0040]
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[0041]
(Wherein Ar is a substituted or unsubstituted phenyl group, naphthyl group; R is C ₁ ~ C ₉ And n represents an integer of 2 or 3. )). These compounds may be used alone or in combination of two or more. Among the compounds exemplified above, the compound represented by the above formula (VII) and the compound represented by the following formula (XI) are particularly preferably used because of their excellent acid generation efficiency with respect to i-line.
[0042]
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[0043]
In the present embodiment, the component (C) can be used alone or in combination of two or more.
The amount of the component (C) is 1 to 30 parts by mass, preferably 1 to 20 parts by mass, per 100 parts by mass of the component (A).
[0044]
・ (D) component
In the chemically amplified positive photoresist composition of the present invention, it is preferable that a basic compound (preferably an amine) is blended as the component (D) in order to enhance the storage stability.
The compound is not particularly limited as long as it has compatibility with the photoresist composition, and examples thereof include compounds described in JP-A-9-6001.
[0045]
In particular, by adding a relatively bulky specific basic compound (d1) represented by the following general formula (III), the effect of suppressing the amount of an acid component by-produced in a resist composition over time can be reduced. And the long-term storage stability of the resist composition can be improved.
[0046]
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[0047]
In the general formula (III), one or more (preferably two or more, most preferably three) of X, Y, and Z are represented by the following (1) to (4)
(1) an alkyl group having 4 or more carbon atoms,
(2) a cycloalkyl group having 3 or more carbon atoms,
(3) a phenyl group,
(4) aralkyl group
Is a group selected from
Further, among the X, Y, and Z, those other than the above (1) to (4) are:
(1 ′) an alkyl group having 3 or less carbon atoms,
(2 ′) a group or atom selected from hydrogen atoms.
X, Y and Z may be the same or different from each other, but when two or more of X, Y and Z are groups selected from the above (1) to (4), It is preferable that these groups are the same from the viewpoint of the stability of the effect.
[0048]
.. (1) alkyl group having 4 or more carbon atoms
In the case of (1), if the number of carbon atoms is less than 4, it is difficult to improve the stability over time. The number of carbon atoms is more preferably 5 or more, particularly preferably 8 or more. The upper limit is not particularly limited, but is set to 20 or less, particularly 15 or less from the viewpoint that the effect of stabilizing over time is recognized and that it is commercially available. In addition, when it exceeds 20, the basic strength becomes weak, and the effect of storage stability decreases.
The alkyl group may be linear or branched.
Specifically, for example, n-decyl group, n-octyl group, n-pentyl group and the like are preferable.
[0049]
.. (2) Cycloalkyl groups having 3 or more carbon atoms
Among the cycloalkyl groups, particularly, a cycloalkyl group having 4 to 8 carbon atoms is commercially available, and is excellent in the effect of improving the stability over time and is preferable. Particularly, a cyclohexyl group having 6 carbon atoms is preferable.
[0050]
.. (4) aralkyl group
The aralkyl group is represented by a general formula, -R'-P (R 'is an alkylene group, and P is an aromatic hydrocarbon group).
Examples of P include a phenyl group and a naphthyl group, and a phenyl group is preferable.
The number of carbon atoms in R 'may be 1 or more, and preferably 1 to 3.
As the aralkyl group, for example, a benzyl group, a phenylethyl group and the like are preferable.
[0051]
Among X, Y and Z, those other than (1) to (4) are groups or atoms selected from the above (1 ′) and (2 ′).
[0052]
(1 ′) may be linear or branched. Particularly, a methyl group and an ethyl group are preferable.
As the component (d1), those constituting a tertiary amine are preferable, and among X, Y and Z, those other than the above (1) to (4) are preferably selected from (1 ′). . For example, specific examples include tri-n-decylamine, methyl-di-n-octylamine, tri-n-pentylamine, N, N-dicyclohexylmethylamine, and tribenzylamine.
Among them, one or more selected from tri-n-decylamine, methyl-di-n-octylamine and tri-n-pentylamine are preferable, and tri-n-decylamine is particularly preferable.
[0053]
In the present embodiment, the component (D) can be used alone or in combination of two or more.
The component (D) is preferably added in an amount of 0.01 to 5.0 parts by mass, particularly 0.1 to 1.0 part by mass based on 100 parts by mass of the resin solid content, from the viewpoint of the effect.
[0054]
·Organic solvent
The organic solvent in the photoresist composition of the present embodiment can be used without any particular limitation as long as it is used in a chemically amplified positive photoresist composition.
For example, ester solvents such as propylene glycol monoalkyl ether acetate (eg, propylene glycol monomethyl ether acetate (PGMEA), etc.) and lactic acid esters (eg, ethyl lactate), acetone, methyl ethyl ketone, cyclohexanone, methyl isoamyl ketone, 2-heptanone, etc. Ketones; ethylene glycol, propylene glycol, diethylene glycol, or polyhydric alcohols such as monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether or monophenyl ether and derivatives thereof; cyclic ethers such as dioxane; And the like. Since the ester solvent is a reaction product of an organic carboxylic acid and an alcohol, it contains an organic carboxylic acid which is a free acid. Therefore, in a resist composition not containing the component (D) or a resist composition not containing a storage stabilizer described later, it is preferable to select such a non-ester solvent containing no free acid, particularly Ketones (ketone-based solvents) are preferred. Among them, 2-heptanone is preferred from the viewpoint of coating properties and solubility of the component (C).
[0055]
In addition, both the ester solvent and the non-ester solvent may decompose with time to produce an acid as a by-product, but in the presence of the component (D) or in the presence of a storage stabilizer described below, The decomposition reaction is suppressed. Particularly, the effect is remarkable in an ester solvent, and in the presence of the component (D) and the storage stabilizer, an ester solvent is preferable, and PGMEA is particularly preferable.
In addition, it has been confirmed that, for example, in the case of 2-heptanone, formic acid, acetic acid, propionic acid, and the like are generated as an acid component by-produced by the decomposition.
The organic solvent can be used alone or in combination of two or more.
Although not particularly limited, the organic solvent is preferably used in an amount of from 20 to 50% by mass, and preferably from 25 to 45% by mass, from the viewpoint of applicability.
[0056]
The chemically amplified positive photoresist composition of the present invention preferably further contains the following storage stabilizers as necessary.
The storage stabilizer is not particularly limited as long as it has an action of suppressing the decomposition reaction of the solvent, and examples thereof include an antioxidant described in JP-A-58-194834. it can. Phenol compounds and amine compounds are known as antioxidants, and phenol compounds are particularly preferable. Among them, 2,6-di (tert-butyl) -p-cresol and its derivatives are ester solvents, It is preferable because it is effective against the deterioration of the ketone solvent, is commercially available, is inexpensive, and has an excellent storage stability effect. In particular, it is extremely excellent in the effect of preventing deterioration of propylene glycol monoalkyl ether acetate and 2-heptanone.
The compounding amount is preferably in the range of 0.01 to 3 parts by mass, particularly preferably 0.1 to 1.0 part by mass with respect to 100 parts by mass of the resin solid content.
[0057]
Further, the photoresist composition of the present embodiment may contain a compatible additive, for example, an additional resin for improving the performance of the resist film, if necessary, as long as the object of the present invention is not impaired. Agents, stabilizers, surfactants, coloring agents for making the developed image more visible, sensitizers for improving the sensitizing effect, dyes for preventing halation, and adhesion improving agents such as Additives can be included.
[0058]
・ Method of producing positive photoresist composition
The positive photoresist composition of the present embodiment is obtained by converting the component (A), the component (C), and other components, if necessary, from the solid content contained in the photoresist composition into a polystyrene equivalent by gel permeation chromatography. It can be produced by adjusting the mass average molecular weight (Mw) to be in the range of 3,000 to 100,000, preferably 5,000 to 50,000, and dissolving it in an organic solvent.
The amount of the organic solvent used is suitably adjusted so that a uniform positive photoresist composition is preferably obtained when the components (A) and (C) and other components used as necessary are dissolved. It is preferably used so that the solid content concentration is 10 to 50% by mass, more preferably 20 to 35% by mass. The solid content of the positive photoresist composition corresponds to the sum of the components (A) and (C) and other components used as needed.
[0059]
As a method of performing the step of adjusting the Mw of the positive photoresist composition to be in a suitable range, for example, (1) Before mixing, (A) before mixing so that Mw after mixing all the components is in the above range. ) A method of preliminarily adjusting the Mw of the component (A) to an appropriate range, for example, by performing a separation operation on the component, and (2) preparing a plurality of the components (A) having different Mw and appropriately mixing the components. Then, there is a method of adjusting the Mw of the solid content to the above range.
Among these preparation methods, the preparation method according to the above (2) is more preferable in that the adjustment of the resist molecular weight and the sensitivity adjustment are easy.
[0060]
The positive photoresist composition of the present embodiment is prepared so that the Mw of the solid content contained in the photoresist composition is in the range of 3,000 to 100,000, and the more preferred Mw is 5,000 to 50,000.
Since the positive photoresist composition of the present embodiment exhibits a chemical amplification type mechanism, the development contrast between the unexposed portion and the exposed portion is strong, and good resolution and DOF are obtained within the preferred range of Mw. Properties can be obtained.
By setting the Mw of the solid content of the positive photoresist composition of the present embodiment to the above range, the positive photoresist composition has high heat resistance, high resolution, excellent linearity and DOF characteristics, and has good sensitivity. A photoresist composition is obtained.
When the Mw of the solid content of the photoresist composition is smaller than the above range, heat resistance, resolution, linearity, and DOF characteristics become insufficient. When the Mw exceeds the above range, the sensitivity is significantly reduced, and the application of the photoresist composition is performed. May be impaired.
[0061]
[Second embodiment]
・ (A) component
In a second embodiment of the chemically amplified positive photoresist composition of the present invention, the component (A) comprises (a2) an alkali-soluble resin and (B) a compound represented by the following general formula (I): Contains reaction products.
The component (a2) in the present embodiment can be used without any particular limitation as long as it is an alkali-soluble resin used in a photoresist composition, but having a phenolic hydroxyl group means that it has a reactivity with the component (B). Preferred from the point.
As the component (a2), those exemplified as the alkali-soluble resin component constituting the component (a1) in the first embodiment can be suitably used.
[0062]
When a novolak resin is used as the component (a2), its Mw is preferably from 1,000 to 50,000, more preferably from about 1,000 to 20,000 from the viewpoint of sensitivity characteristics. The more preferable range of Mw is 2000-15000. If the ratio is smaller than the above range, the resolution may be lowered. If the ratio is beyond the above range, the coating property is deteriorated.
When a novolak resin is used as the component (a2), it is preferable to use the component (D) or a storage stabilizer in combination from the viewpoint of long-term storage stability of the resist composition.
[0063]
When a hydroxystyrene-based resin is used as the component (a2), it is preferable that the content of the hydroxystyrene unit is at least 50 to 99 mol%, preferably 70 to 90 mol%, from the viewpoint of the reactivity of the component (B).
In particular, hydroxystyrene-based resin is a resin having almost no acidity as compared with novolak resin. Since the strength of the acidity of the component (A) affects the storage stability of the resist composition, it is desirable to select a hydroxystyrene-based resin for the purpose of adjusting the resist composition having good storage stability. . Above all, the styrene and the hydroxystyrene resin containing the styrene structural unit derived from the styrene derivative and the alkyl-substituted styrene structural unit (hereinafter, both are referred to as “styrene-based structural unit”) are sensitive to the resist composition. , Heat resistance and the effect of improving the shape of the resist pattern. The content of the styrene-based structural unit is preferably from 1 to 30 mol%, more preferably from 5 to 15 mol%, from the viewpoints of ensuring reactivity with the component (B), improving heat resistance, and improving sensitivity.
[0064]
When a hydroxystyrene-based resin is used as the component (a2), its Mw is preferably from 1,000 to 40,000, more preferably from 1,000 to 8,000, and particularly preferably from 2,000 to 6,000, as to increase heat resistance, increase sensitivity, and stabilize the reaction with a crosslinking agent. It is preferable in terms of properties.
As the component (a2), one or more kinds of materials can be used.
[0065]
・ B component
The component (B) is a compound represented by the following general formula (I) and acts as a crosslinking agent.
[0066]
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[0067]
[Wherein, R ¹ Is an alkylene group having 1 to 10 carbon atoms which may have a substituent, or the following general formula (II)
[0068]
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[0069]
(Where R ⁴ Represents an alkylene group having 1 to 10 carbon atoms which may have a substituent, and m represents 0 or 1. )
Represents any of the groups represented by ]
[0070]
In the general formula (I), R ¹ Is a branched or linear alkylene group having 1 to 10 carbon atoms, which may have a substituent, or represented by the general formula (II). The alkylene group may contain an oxygen bond (ether bond) in the main chain. In the general formula (II), R ⁴ Is a branched or straight-chain alkylene group having 1 to 10 carbon atoms which may have a substituent, and the alkylene group contains an oxygen bond (ether bond) in the main chain. Is also good. R ¹ Is -C ₄ H ₈ -, -C ₂ H ₄ OC ₂ H ₄ -, -C ₂ H ₄ OC ₂ H ₄ OC ₂ H ₄ -, And those represented by the general formula (II) are preferred, and those represented by the general formula (II) are particularly preferred. ⁴ Is preferably one having 1 carbon atom and m being 1.
The component (B) can be used alone or in combination of two or more.
[0071]
・ (A3) component
The component (a3) is a reaction product obtained by reacting the component (a2) with the component (B), and has a property that it is hardly soluble in an aqueous alkali solution and becomes soluble by the action of an acid component.
When the component (a2) is allowed to react with the component (B), a reaction having a structural unit in which a vinyl group at one end of the component (B) is bonded to, for example, a phenolic hydroxyl group in a side chain of the component (a2) is performed. The product is obtained.
Specific examples of such a structural unit include a structural unit represented by the following general formula (1A) and a structural unit represented by the following general formula (2A).
When the component (a2) is reacted with the component (B), the vinyl groups at both ends of the component (B) are bonded to, for example, two phenolic hydroxyl groups in the side chain in the component (a2). Is obtained. Specific examples of such a structural unit include an intermolecular cross-linking moiety represented by the following general formula (1B) or an intermolecular cross-linking moiety represented by the following general formula (2B).
In general, a reaction in which both a structural unit (for example, (1A) and (2A)) in which only one end of the component (B) is bonded and a part in which both are bonded (for example, (1B) and (2B)) are present. The product (a3) is obtained.
[0072]
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[0073]
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[0074]
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[0075]
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[0076]
R ¹ Is the same as above, and R ² , R ³ Is a group derived from phenols, aldehydes, ketones and the like described in the description of the novolak resin.
[0077]
The component (a3) in the present invention can be obtained by reacting the component (a2) with the component (B), preferably in the substantial absence of an acid catalyst.
Since the component (B) is bonded to the hydroxyl group of the side chain of the alkali-soluble resin (a2) in advance, the resist coating solution (composition) can be prevented from changing over time, resulting in a resist material having less change over time in sensitivity. . Then, when the resist material is applied on a substrate and heated, the phenolic hydroxyl group in the side chain of the component (a2) reacts with the terminal vinyl group of the structural unit (1A) or (2A) to form a crosslinked structure. Is done. Thus, the resist coating becomes poorly soluble in an alkaline aqueous solution such as an alkaline developer used for forming a resist pattern.
Then, when an acid generated from the component (C) by exposure acts on the component (a3) having the crosslinked structure, the crosslinked structure is cleaved, and the solubility of the component (a3) in the alkaline aqueous solution increases.
[0078]
When a novolak resin is selected as the component (a2), the reaction between the component (a2) and the component (B) proceeds without using an acid catalyst. Therefore, it is essential to use an acid catalyst. On the contrary, if an acid component is present in the reaction system, it is not preferable in terms of storage stability after the preparation of the resist. When a hydroxystyrene resin is selected as the component (a2), the acid component concentration must be strictly controlled when the component (a2) is reacted with the component (B). It is not preferable that the component (a2) is contained in the component. Therefore, it is preferable to strictly remove the acid component contained in the component (a2) before reacting with the component (B). The acid component is, for example, an acid catalyst used in the synthesis of a novolak resin, an organic acid such as a free acid present in a reaction solvent, and can be analyzed by gas chromatography or the like.
As a method for removing the acid component, a known method can be used, and for example, a method such as use of an ion exchange resin, washing with pure water, and neutralization with an alkali can be applied.
The concentration of the acid component in the component (a2) before the reaction with the component (B) is preferably 0.1 ppm or less, particularly preferably 0.01 ppm or less.
[0079]
When the novolak resin is selected as the component (a2), the mass average molecular weight of the component (a3) obtained by reacting the component (a2) and the component (B) is 10,000 to 70000, particularly 20,000 to 50,000, and (a2) When a hydroxystyrene-based resin is selected as the component (3), it is preferably 30,000 to 150,000, particularly preferably 40,000 to 100,000 from the viewpoint of heat resistance and the like.
[0080]
When a novolak resin is selected as the component (a2), the component (B) is used in an amount of 1 to 15% by mass, preferably 4 to 8% by mass, based on the component (a2). If the amount is less than 1% by mass, the film loss of the unexposed portion of the resist pattern tends to be large, and the contrast of the resist pattern tends to decrease. , The sensitivity may be poor, and the pattern may not be resolved. When a hydroxystyrene resin is selected as the component (a2), it is used in a proportion of 1 to 15% by mass, preferably 5 to 10% by mass, based on the component (a2).
[0081]
・ (C) component
The component (C) in the present embodiment is the same as in the first embodiment.
[0082]
・ (D) component
The component (D) in the present embodiment can have the same configuration as the component (D) in the first embodiment. In particular, in the present embodiment, it is preferable to use the component (d1) as the component (D).
[0083]
・ Organic solvent
As the organic solvent in the present embodiment, the same organic solvent as in the first embodiment can be used.
[0084]
The organic solvent can be used alone or in combination of two or more.
Although not particularly limited, the organic solvent is preferably used in an amount of from 20 to 50% by mass, and preferably from 25 to 45% by mass, from the viewpoint of applicability.
Also, in the present embodiment, the same storage stability as in the first embodiment can be used if necessary.
[0085]
Further, the photoresist composition of the present embodiment may contain other components similar to those of the first embodiment as long as the object of the present invention is not impaired.
[0086]
・ Method of producing positive photoresist composition
The photoresist composition of the present embodiment can be manufactured in the same manner as in the first embodiment.
[0087]
The positive photoresist composition of the present embodiment is prepared such that Mw of the solid content contained in the photoresist composition is in the range of 3,000 to 100,000, and more preferably Mw is 10,000 to 80,000.
According to the photoresist composition of the present embodiment, in addition to the same operation and effect as those of the first embodiment, the crosslinked structure is formed as described above when the resist material is applied on a substrate and heated. In particular, a resist pattern having excellent heat resistance can be obtained, and film loss can be prevented.
[0088]
[Third Embodiment]
・ (A) (B) component
In the third embodiment of the chemically amplified positive photoresist composition of the present invention, the component (A) contains (a2) an alkali-soluble resin, and further comprises the component (B) represented by the general formula (I). Contains.
The component (a2) and the component (B) in the present embodiment can have the same configuration as that of the second embodiment, and the present embodiment is largely different from the second embodiment in that the component (a2) The point is that the component (A) is contained in the component (A) without reacting with the component (B).
In the present embodiment, when a novolak resin is selected as the component (a2), the component (B) is used in an amount of 1 to 50% by mass, preferably 5 to 35% by mass, based on the component (a2). If the amount is less than 1% by mass, the film loss of the unexposed portion of the resist pattern tends to increase, and the contrast of the resist pattern tends to decrease. , The sensitivity may be poor, and the pattern may not be resolved. When a hydroxystyrene resin is selected as the component (a2), it is used in a proportion of 1 to 50% by mass, preferably 5 to 40% by mass, based on the component (a2).
[0089]
・ (C) component
The component (C) in the present embodiment is the same as in the first embodiment.
・ (D) component
The component (D) in this embodiment is the same as that in the second embodiment.
・ Organic solvent
The organic solvent in the present embodiment is the same as in the first embodiment.
[0090]
Further, the photoresist composition of the present embodiment may contain other components similar to those of the first embodiment as long as the object of the present invention is not impaired.
[0091]
・ Method of producing positive photoresist composition
The photoresist composition of the present embodiment can be manufactured in the same manner as in the first embodiment.
[0092]
The positive photoresist composition of the present embodiment is prepared such that Mw of the solid content contained in the photoresist composition is in the range of 3,000 to 100,000, and more preferably Mw is 4,000 to 30,000.
According to the photoresist composition of the present embodiment, the same functions and effects as those of the second embodiment can be obtained.
[0093]
[Method of forming resist pattern]
Hereinafter, a preferred example of a method for producing a system LCD using the photoresist composition of the present invention will be described.
First, the components (A) and (C) and various components added as necessary are dissolved in a solvent, and the resulting solution is applied to a substrate with a spinner or the like to form a coating film. A glass substrate is preferred as the substrate. As this glass substrate, amorphous silica is usually used, but in the field of system LCD, low-temperature polysilicon or the like is preferable. In addition, a large substrate having a size of 500 mm x 600 mm or more, particularly 550 mm x 650 mm or more can be used.
[0094]
Next, the glass substrate on which the coating film is formed is subjected to a heat treatment (prebaking) at, for example, 90 to 140 ° C. to remove the residual solvent, thereby forming a resist coating film. As a pre-bake method, it is preferable to perform proximity bake for providing a gap between the hot plate and the substrate.
Next, the resist film is selectively exposed using a mask on which both a mask pattern for an integrated circuit and a mask pattern for a liquid crystal display are drawn.
As a light source used here, it is preferable to use i-line (365 nm) in order to form a fine pattern. The exposure process employed in this exposure is preferably an exposure process with a low NA of 0.3 or less, preferably 0.2 or less, more preferably 0.15 or less. By employing an exposure process under a low NA condition, a single exposure area can be widened, and the throughput can be improved.
[0095]
Next, a heat treatment (post-exposure bake: PEB) is performed on the resist film after the selective exposure. Examples of the PEB method include proximity baking for providing a gap between the hot plate and the substrate, and direct baking for providing no gap, without causing warpage of the substrate, and in order to obtain a diffusion effect by PEB, A method of performing direct baking after performing proximity baking is preferable. The heating temperature is preferably from 90 to 150 ° C, particularly preferably from 100 to 140 ° C.
When the resist film after the PEB is subjected to a developing treatment using a developing solution, for example, an alkaline aqueous solution such as a 1 to 10% by mass aqueous solution of tetramethylammonium hydroxide, the exposed portion is dissolved and removed, and the exposed portion is accumulated on the substrate. A resist pattern for a circuit and a resist pattern for a liquid crystal display portion are simultaneously formed.
Next, the resist pattern can be formed by washing away the developing solution remaining on the resist pattern surface with a rinse solution such as pure water.
[0096]
In the step of performing the selective exposure, it is preferable to use, as the mask, a mask on which both a resist pattern forming mask pattern of 2.0 μm or less and a resist pattern forming mask pattern of more than 2.0 μm are drawn.
Since the chemically amplified positive photoresist composition of the present invention is excellent in linearity, a resist pattern that faithfully reproduces both rough and fine mask patterns can be obtained. Therefore, a resist pattern for an integrated circuit having a pattern size of 2.0 μm or less and a resist pattern for a liquid crystal display portion having a pattern size of more than 2.0 μm can be simultaneously formed on the substrate.
[0097]
【Example】
Hereinafter, the present invention will be described in detail with reference to examples.
Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples.
[0098]
[Evaluation method of positive photoresist composition]
Evaluation methods for the following physical properties (1) to (5) for the positive photoresist compositions of the following examples or comparative examples are shown below.
(1) Sensitivity evaluation: Positive photoresist composition was applied on a glass substrate (550 mm × 650 mm) on which a Ti film was formed using a large substrate resist coating device (TR36000 manufactured by Tokyo Ohka Kogyo Co., Ltd.). After that, prebaking was performed by proximity baking with an interval of about 1 mm under a heating condition of 140 ° C. and 90 seconds to form a 1.5 μm-thick resist film.
Then, an i-line exposure apparatus (apparatus name: FX-702J, Nikon Corporation) is passed through a test chart mask (reticle) on which a 1.5 μmL & S resist pattern and a mask pattern for reproducing the 3.0 μmL & S resist pattern are simultaneously drawn. (NA = 0.14) by using an exposure amount (Eop exposure amount) capable of faithfully reproducing 1.5 μmL & S.
Next, PEB was applied by proximity baking with a 0.5 mm interval at 110 ° C. for 90 seconds.
Next, after performing a development process for 60 seconds using a 2.38 mass% TMAH aqueous solution at 23 ° C., the substrate was rinsed with pure water for 30 seconds and spin-dried.
As an index for sensitivity evaluation, an exposure amount (Eop, unit: mJ) capable of faithfully reproducing a 1.5 μmL & S resist pattern was used.
[0099]
(2) DOF characteristic evaluation: In the above Eop exposure amount, the focus is shifted up and down as appropriate, and the width of the depth of focus (DOF) obtained in a range of dimensional change of 1.5 μmL & S of ± 10% is obtained in μm unit. Was.
(3) Heat resistance evaluation: At the above Eop exposure amount, the substrate on which 1.5 μmL & S was drawn was allowed to stand on a hot plate set at 140 ° C. for 300 seconds, and the cross-sectional shape was observed. As a result, those in which the dimensional change rate of 1.5 μmL & S was within ± 3% were ○, those in the range of 3 to 5% or -5 to -3% were Δ, and those in which it exceeded ± 5% Is represented as x.
(4) Evaluation of resolution: The critical resolution at the above Eop exposure was determined.
(5) Linearity evaluation: The cross-sectional shape of the 3.0 μmL & S resist pattern obtained with the above Eop exposure amount was observed with an SEM (scanning electron microscope) photograph, and the reproducibility of the 3.0 μmL & S resist pattern was evaluated. When the dimensional change rate of 3.0 μmL & S was within ± 10%, it was represented by ○, and when it exceeded ± 10%, it was represented by ×.
[0100]
In the following examples, the following was used as the component (A).
・ (A1) component
To 267 g of a 15% by weight solution of polyhydroxystyrene having a weight average molecular weight of 8000 [solvent = 2-heptanone], 17.8 g of triethylamine and 38.25 g of di-tert-butyl-di-carbonate were added and reacted at 22 ° C. for 2 hours. Was done. Next, the reaction solution was poured into 500 ml of a 1.5% by weight aqueous acetic acid solution, allowed to stand, and the organic solvent layer (upper layer) was taken out by decantation. Thereafter, a washing operation was performed twice using 500 ml of pure water, and then the organic solvent was removed under reduced pressure to obtain 35 g of polyhydroxystyrene in which 35% of phenolic hydroxyl groups were protected by t-butoxycarbonyl group.
[0101]
・ (A2) component
Polyhydroxystyrene resin having a styrene constitutional unit / hydroxystyrene constitutional unit of 15/85 and Mw of 5000.
・ (A3) component
The above-mentioned component (a2) (Mw: 5000) is stirred and dissolved in a methyl isobutyl ketone (MIBK) solvent so as to have a concentration of 30% by mass, and the internal temperature is set to 100 to 110 ° C. The compound (component (B)) was added dropwise in an amount corresponding to 8 parts by mass with respect to 100 parts by mass of the resin solid content. After the reaction for 24 hours, post-stirring was performed at room temperature for 12 hours or more, and then, solvent replacement from MIBK to 2-heptanone was performed.
The Mw of the obtained component (a3) was 55,000.
[0102]
Embedded image

[0103]
(Example 1)
The component (a1) (Mw: 8000): 100 parts by mass
Component (C) [compound of formula (XI)]: 3 parts by mass
(D) Component [tri-n-decylamine]: 0.2 part by mass
The above-mentioned various components were dissolved in PGMEA, and 500 ppm of XR-104 (manufactured by Dainippon Ink and Chemicals) was added as a surfactant to adjust the solution to a concentration of 35% by mass. And filtered to prepare a photoresist composition. Mw of the obtained photoresist composition was 7,500.
The physical properties (1) to (5) of the photoresist composition were evaluated. The results are shown in Table 1 below.
[0104]
(Example 2)
The component (a3), (Mw: 55000): 100 parts by mass
Component (C) [compound of formula (XI)]: 3 parts by mass
(D) Component [tri-n-decylamine]: 0.2 part by mass
The above-mentioned various components were dissolved in PGMEA, and 500 ppm of XR-104 (manufactured by Dainippon Ink and Chemicals) was added as a surfactant to adjust the solution to a concentration of 35% by mass. And filtered to prepare a photoresist composition. Mw of the obtained photoresist composition was 50,000.
The physical properties (1) to (5) of the photoresist composition were evaluated. The results are shown in Table 1 below.
[0105]
(Example 3)
The component (a2), (Mw: 5000): 100 parts by mass
Component (B) [compound of the above formula ([Chemical Formula 22]): 7 parts by mass
Component (C) [compound of formula (XI)]: 3 parts by mass
(D) Component [tri-n-decylamine]: 0.2 part by mass
The above-mentioned various components were dissolved in PGMEA, and 500 ppm of XR-104 (manufactured by Dainippon Ink and Chemicals) was added as a surfactant to adjust the solution to a concentration of 35% by mass. And filtered to prepare a photoresist composition. Mw of the obtained photoresist composition was 4,500.
The physical properties (1) to (5) of the photoresist composition were evaluated. The results are shown in Table 1 below.
[0106]
(Comparative Example 1)
Example 1 Example 1 was repeated except that in place of the component (a1) (Mw: 8000), polyhydroxystyrene (Mw: 1500) in which 35% of the phenolic hydroxyl groups were protected with a t-butoxycarbonyl group was used. In the same manner as in Example 1, a photoresist composition was prepared. Mw of the obtained photoresist composition was 1,000. The physical properties (1) to (5) of the photoresist composition were evaluated. The results are shown in Table 1 below.
[0107]
(Comparative Example 2)
In Example 2, instead of the component (a3) (Mw: 55000), the above-mentioned formula was used with respect to 100 parts by mass of a polyhydroxystyrene resin having a styrene constitutional unit / hydroxystyrene constitutional unit of 15/85 and Mw of 1500. A photoresist composition was prepared in the same manner as in Example 1 except that a resin (Mw = 2500) obtained by mixing 1 part by mass of the compound represented by Chemical Formula 22 was used. Mw of the obtained photoresist composition was 2,000.
The physical properties (1) to (5) of the photoresist composition were evaluated. The results are shown in Table 1 below.
[0108]
(Comparative Example 3)
Example 3 was repeated in the same manner as in Example 3 except that a polystyrene resin having a styrene constitutional unit / hydroxystyrene constitutional unit of 15/85 and Mw of 1500 was used instead of the component (a2) (Mw: 5000). Thus, a photoresist composition was prepared. Mw of the obtained photoresist composition was 1,000.
[0109]
(Comparative Example 4)
In the same manner as in Example 3 except that a polystyrene resin having a styrene constitutional unit / hydroxystyrene constitutional unit of 15/85 and Mw of 150,000 was used instead of the component (a2) (Mw: 5000) in Example 3, Thus, a photoresist composition was prepared. Mw of the obtained photoresist composition was 145000.
[0110]
[Table 1]

[0111]
【The invention's effect】
As described above, the chemically amplified positive photoresist composition of the present invention has good sensitivity, excellent heat resistance, and high resolution, so that it is suitable for manufacturing system LCDs and can improve throughput. it can.
Further, because of its excellent linearity, a rough pattern and a fine pattern can be formed on one substrate under the same exposure conditions. Therefore, the resist pattern of the display portion of the system LCD and the finer integrated circuit portion can be obtained at a high resolution at the same time, which is suitable for manufacturing the system LCD.
Further, in a positive photoresist composition for manufacturing a system LCD, it is important that the width of the depth of focus (DOF) is large to some extent from the viewpoints of manufacturing efficiency, easy control of manufacturing conditions, and the like. The chemically amplified positive photoresist composition can realize a practical depth of focus (for example, 15 μm or more) for system LCD.

Claims (10)

A chemically amplified positive photoresist composition for manufacturing a substrate in which an integrated circuit and a liquid crystal display portion are formed on one substrate,
(A) a resin component, (C) a compound that generates an acid component upon irradiation with radiation, and an organic solvent,
Having the property of increasing solubility in an aqueous alkali solution by the action of an acid component generated from the component (C);
A chemically amplified positive photoresist composition, characterized in that the solid content contained in the photoresist composition has a mass average molecular weight (Mw) in terms of polystyrene by gel permeation chromatography in the range of 3,000 to 100,000. The component (A) contains (a1) a structural unit having a phenolic hydroxyl group, and a partially alkali-soluble or insoluble resin in which a part of all phenolic hydroxyl groups is protected by an acid dissociable, dissolution inhibiting group; 2. The chemically amplified positive photoresist composition according to claim 1, wherein Mw of the solid content contained in the photoresist composition is in the range of 5,000 to 50,000. The component (A) contains (a2) a reaction product of (a2) an alkali-soluble resin and (B) a compound represented by the following general formula (I), and Mw of solid content contained in the photoresist composition. 2. The chemically amplified positive photoresist composition according to claim 1, wherein is in the range of 10,000 to 80000.

[Wherein, R ¹ represents an alkylene group having 1 to 10 carbon atoms which may have a substituent, or a compound represented by the following general formula (II):

(In the formula, R ⁴ represents an alkylene group having 1 to 10 carbon atoms which may have a substituent, and m represents 0 or 1.)
Represents any of the groups represented by ] The component (A) contains (a2) an alkali-soluble resin,
Further, the photoresist composition contains (B) a compound represented by the following general formula (I), and Mw of a solid content contained in the photoresist composition is in a range of 4000 to 30,000. The chemically amplified positive photoresist composition according to claim 1.

[Wherein, R ¹ represents an alkylene group having 1 to 10 carbon atoms which may have a substituent, or a compound represented by the following general formula (II):

(In the formula, R ⁴ represents an alkylene group having 1 to 10 carbon atoms which may have a substituent, and m represents 0 or 1.)
Represents any of the groups represented by ] The chemically amplified positive photoresist composition according to any one of claims 1 to 4, further comprising (D) a basic compound. The chemically amplified positive photoresist composition according to claim 5, wherein the component (D) contains (d1) a compound represented by the following general formula (III).

[Wherein one or more of X, Y, and Z are the following (1) to (4)
(1) an alkyl group having 4 or more carbon atoms,
(2) a cycloalkyl group having 3 or more carbon atoms,
(3) a phenyl group,
(4) an aralkyl group,
Is a group selected from
Among the X, Y, and Z, those other than the above (1) to (4) are:
(1 ′) an alkyl group having 3 or less carbon atoms,
(2 ′) a group or atom selected from hydrogen atoms. ] 7. The chemically amplified positive photoresist composition according to claim 5, wherein the component (D) is added in an amount of 0.01 to 5 parts by mass with respect to 100 parts by mass of the component (A). The chemically amplified positive photoresist composition according to any one of claims 1 to 7, wherein the component (C) is a compound that generates an acid component upon irradiation with i-ray (365 nm). (1) a step of applying the positive photoresist composition according to any one of claims 1 to 8 on a substrate to form a coating, and (2) heating the substrate on which the coating is formed ( Pre-baking) to form a resist film on the substrate. (3) Both the mask pattern for forming a resist pattern of 2.0 μm or less and the mask pattern for forming a resist pattern of more than 2.0 μm are formed on the resist film. Performing a selective exposure using the drawn mask; (4) performing a heat treatment (post-exposure bake) on the resist film after the selective exposure; and (5) applying a resist film after the heat treatment. On the other hand, a resist pattern for an integrated circuit having a pattern size of 2.0 μm or less and a liquid crystal display portion having a pattern size of more than 2.0 μm are formed on the substrate by performing a development process using an alkaline aqueous solution. The method of forming a resist pattern, which comprises step a of the resist pattern at the same time the formation of. 10. The resist according to claim 9, wherein the step (3) of performing selective exposure is performed by an exposure process under a low NA condition of using an i-line as a light source and having an NA of 0.3 or less. The method of forming the pattern.