JP4182867B2 - Radiation sensitive resin composition - Google Patents

Description

The present invention relates to a radiation-sensitive resin composition, and in particular, for fine processing using various kinds of radiation such as deep ultraviolet rays such as KrF excimer laser or ArF excimer laser, X-rays such as synchrotron radiation, and charged particle beams such as electron beams. The present invention relates to a radiation sensitive resin composition that can be suitably used as a useful chemically amplified resist.
To do.

In the field of microfabrication represented by the manufacture of integrated circuit elements, in order to obtain a higher degree of integration, recently, an ArF excimer laser (wavelength 193 nm), an F ₂ excimer laser (wavelength 157 nm) or the like has been used. There is a need for a lithography technique capable of microfabrication at the same level. As a radiation-sensitive resin composition suitable for irradiation with such an excimer laser, a chemical utilizing the chemical amplification effect by the component having an acid-dissociable functional group and the acid generator which is a component generating an acid by irradiation with radiation. Many amplified radiation-sensitive compositions have been proposed. For example, as a resin component, a polymer compound for a photoresist having a specific structure including a monomer unit having a norbornane ring derivative as a resin component is known (Patent Documents 1 and 2).
JP 2002-201232 A JP 2002-145955 A

On the other hand, living radical polymerization in which radical polymerization is controlled using a special chain transfer agent is known, and the chain transfer agent has also been proposed (Patent Documents 3 to 6, Non-Patent Document 1).
International Publication WO98 / 01478 International Publication No. WO99 / 05099 US Pat. No. 6,395,850 US Patent Publication No. 6,380,335 Macromolecules 1999, 32, 6977-6980

However, when a higher degree of integration is required in the semiconductor field, a radiation-sensitive resin composition that is a resist is required to have better resolution. One of the reasons why the resolution cannot be obtained is a pattern profile defect in which the resist pattern after development becomes narrower at the top and becomes thicker as it goes down.
At the same time, as the miniaturization progresses, the demand for reducing the line edge roughness of the pattern has increased. As the semiconductor industry advances in miniaturization, there is an urgent need to develop a radiation-sensitive resin composition that excels in resolution and pattern profile and satisfies the conditions of small pattern line edge roughness.

  The problem to be solved is adaptable to short-wavelength radiation typified by far-ultraviolet rays that can cope with the progress of miniaturization in integrated circuit elements, has high transparency to radiation, and has sensitivity, resolution, pattern profile, pattern A radiation-sensitive resin composition that can be used for a chemically amplified resist having excellent basic physical properties as a resist such as line edge roughness (LER) is not obtained.

式（Ｘ−１）において、Ｒ^aは、置換または非置換の炭化水素基を表し、Ｚは置換または非置換のヘテロ原子を含む基を表す。
また、上記Ｚは式（Ｘ−２)で表される置換基であることを特徴とする。

式（Ｘ−２)中、Ｒ^b、Ｒ^cおよびＲ^dは、相互に独立に水素原子、置換または非置換の炭化水素基、置換または非置換のヘテロ原子を含む炭化水素基またはこれらの基の組み合わせで形成される基、または、Ｒ^b、Ｒ^cおよびＲ^dのいずれか二つが相互に結合して形成される３〜５０の非水素原子を含む環を表す。 The radiation-sensitive resin composition of the present invention comprises an acid-dissociable group-containing polymer (hereinafter abbreviated as polymer (A)) containing at least two types of repeating units having different acid-dissociable groups, and a radiation-sensitive acid. A radiation-sensitive resin composition containing a generator (hereinafter abbreviated as acid generator (B)), wherein the polymer (A) is a chain transfer agent represented by formula (X-1). It is polymerized by the living radical polymerization used.

In the formula (X-1), R ^a represents a substituted or unsubstituted hydrocarbon group, and Z represents a group containing a substituted or unsubstituted heteroatom.
Z is a substituent represented by the formula (X-2).

In the formula (X-2), R ^b , R ^c and R ^d are each independently a hydrogen atom, a substituted or unsubstituted hydrocarbon group, a hydrocarbon group containing a substituted or unsubstituted heteroatom, or these groups Or a ring containing 3 to 50 non-hydrogen atoms formed by combining any two of R ^b , R ^c and R ^d with each other.

式（１）、式（２）または式（３）において、Ｒは水素原子またはメチル基を表し、式（１）において、Ａは、置換または非置換された、シクロペンタン、シクロヘキサン、ビシクロ［２．２．１］ヘプタン、トリシクロ［５．２．１．０^2,6］デカン、またはトリシクロ［３．３．１．１^3,7］デカンより環を形成する炭素原子を除いた残基を表し、Ｂは、置換または非置換された、ビシクロ［２．２．１］ヘプタンまたはトリシクロ［３．３．１．１^3,7］デカンより水素原子を除いた残基を表し、Ｒ¹は相互に独立に炭素数１〜４の直鎖状または分岐状のアルキル基を表す。
また、重合体（Ａ）は分子鎖末端の全てまたはその一部に式（Ｘ−１）で表される連鎖移動剤由来の残基を有することを特徴とする。 The repeating unit having a different acid dissociable group in the polymer (A) is represented by the formula (1), the formula (2) or the formula (3).

In Formula (1), Formula (2), or Formula (3), R represents a hydrogen atom or a methyl group. In Formula (1), A represents a substituted or unsubstituted cyclopentane, cyclohexane, bicyclo [2 2.2.1] heptane, tricyclo [5.2.1.0 ^2,6 ] decane, or tricyclo [3.3.1.1 ^3,7 ] decane, a residue obtained by removing a ring carbon atom. B represents a substituted or unsubstituted residue obtained by removing a hydrogen atom from bicyclo [2.2.1] heptane or tricyclo [3.3.1.1 ^3,7 ] decane, and R ¹ represents Each independently represents a linear or branched alkyl group having 1 to 4 carbon atoms.
Further, the polymer (A) is characterized by having a residue derived from a chain transfer agent represented by the formula (X-1) at all or part of the molecular chain terminals.

  The radiation-sensitive composition of the present invention is a chemically amplified resist that is sensitive to actinic radiation, particularly far ultraviolet rays represented by ArF excimer laser (wavelength 193 nm), has high transparency to radiation, high resolution, and a pattern profile. Excellent basic physical properties as a resist including line edge roughness (LER) of the pattern.

In the present invention, a polymer (A) having a specific repeating unit structure is obtained using a special chain transfer agent. By using this polymer, the basic physical properties as a resist are excellent, the resolution performance is high, and the pattern This is based on the knowledge that a radiation sensitive resin composition having a low line edge roughness can be obtained.
The chain transfer agent of the present invention may be a reversible addition-cleavage chain transfer agent. The reversible addition chain transfer agent here refers to what is generally called RAFT (Reversible Addition-Fragmentation Chain Transfer) Agent in the literature (see Non-Patent Document 1). Z in the reversible addition-cleavage chain transfer agent is preferably bonded to the> C═S group in the molecule represented by the formula (X-1) via a nitrogen atom, a sulfur atom, or an oxygen atom. In the case of a nitrogen atom, dithiocarbamate is formed, and in the case of a sulfur atom, dithiocarbonate is formed.
R ^a is preferably an organic group that can be cleaved as an R ^a radical in the chain transfer agent represented by the formula (X-1). As R ^a , specifically, —CH ₂ Ph, —CH (CH ₃ ) CO ₂ CH ₂ CH ₃ , —CH (CO ₂ CH ₂ CH ₃ ) ₂ , —C (CH ₃ ) ₂ CN, —CH (Ph) CN, —C (CH ₃ ) ₂ CO ₂ R ′ (R ′ represents an alkyl, aryl group, etc.), —C (CH ₃ ) ₂ Ph.

式（Ｘ−３）において、Ｒ^ｅ、Ｒ^ｆとＲ^ｇはそれぞれ独立で水素原子、置換または非置換の炭化水素基、置換または非置換の炭化水素基から選ばれる基である。 In the formula (X-2), the substituted or unsubstituted hydrocarbon group represented by R ^b , R ^c and R ^d is a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or non-substituted group. Examples of the hydrocarbon group containing a substituted or unsubstituted hetero atom as the substituted alkenyl group include a substituted or unsubstituted acyl group, a substituted or unsubstituted aroyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted group And monovalent organic groups such as a heteroaryl group, a substituted or unsubstituted heterocyclo group, a substituted or unsubstituted alkylsulfonyl group, a substituted or unsubstituted alkylsulfinyl group, and a substituted or unsubstituted arylsulfinyl group.
Examples of the ring containing 3 to 50 non-hydrogen atoms formed by bonding any two of R ^b , R ^c and R ^d in formula (X-2) include substituted or unsubstituted pyrazole A ring structure is mentioned. As an example, an example of a pyrazole ring represented by the formula (X-3) is shown.

In Formula (X-3), R ^e , R ^f and R ^g are each independently a group selected from a hydrogen atom, a substituted or unsubstituted hydrocarbon group, and a substituted or unsubstituted hydrocarbon group.

Specific examples of the chain transfer agent that can be used in the present invention are represented by the following formulas (CTA-1) to (CTA-4).

The chain transfer agent used in the present invention can be used in combination with a radical polymerization initiator.
Examples of the radical polymerization initiator that can be used in the present invention include a thermal polymerization initiator, a redox polymerization initiator, and a photopolymerization initiator. Examples thereof include polymerization initiators such as peroxides and azo compounds. Although not particularly limited, specific radical polymerization initiators include t-butyl hydroperoxide, t-butyl perbenzoate, benzoyl peroxide, 2,2′-azobis (2,4-dimethylvaleronitrile), 2, Examples include 2′-azobisisobutyronitrile (AIBN), 1,1′-azobis (cyclohexanecarbonitrile), dimethyl-2,2′-azobisisobutyrate (MAIB), and the like.

The polymer (A) in the present invention is an alkali-insoluble or alkali-insoluble polymer which contains at least two types of repeating units having different acid-dissociable groups and becomes readily alkali-soluble by the action of an acid.
The term “alkali-insoluble or alkali-insoluble” as used herein refers to alkali development conditions (preferably used when forming a resist pattern from a resist film formed from a radiation-sensitive resin composition containing the polymer (A)). Under the condition of developing with an alkaline aqueous solution having a pH of 8 to 14, more preferably an alkaline aqueous solution having a pH of 9 to 14), when a film using only the polymer (A) is developed instead of the resist film. , Meaning that 50% or more of the initial film thickness of the film remains after development. “Alkali readily soluble” means the property that less than 50% of the initial film thickness is lost by dissolving the coating by the same treatment.

上式において、Ｒは水素原子またはメチル基を、Ｒ¹は相互に独立に炭素数１〜４の直鎖状または分岐状のアルキル基をそれぞれ表す。
また、上式において、シクロアルカン由来の脂環族環は、置換基を有していてもよく、例えば、メチル基、エチル基、ｎ−プロピル基、ｉ−プロピル基、ｎ−ブチル基、２−メチルプロピル基、１−メチルプロピル基、ｔ−ブチル基等の炭素数１〜４の直鎖状、分岐状または環状のアルキル基の１種以上あるいは１個以上で置換した骨格等が挙げられる。 The repeating unit having a different acid-dissociable group in the polymer (A) is represented by the formula (1), the formula (2) or the formula (3). As specific examples of the formula (1), the following formula (1- Specific examples of formula (1) to formula (1-4) and formula (2) include formula (2-1) and formula (2-2).

In the above formula, R represents a hydrogen atom or a methyl group, and R ¹ independently represents a linear or branched alkyl group having 1 to 4 carbon atoms.
In the above formula, the cycloalkane-derived alicyclic ring may have a substituent, for example, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, 2 And a skeleton substituted with one or more of linear, branched or cyclic alkyl groups having 1 to 4 carbon atoms such as -methylpropyl group, 1-methylpropyl group and t-butyl group. .

表１に示すように、Ｒ¹がメチル基、またはエチル基である繰り返し単位の組み合わせが好ましい。 In the present invention, the combination of the repeating units having different acid dissociable groups may be, for example, a combination of those in the formula (1-1) or, for example, the repeating unit in the formula (1-1) and the formula (1). -2) may be a combination of repeating units.
Table 1 shows preferable combinations of repeating units in the present invention, and particularly preferable combinations among them.

As shown in Table 1, a combination of repeating units in which R ¹ is a methyl group or an ethyl group is preferable.

上式において、Ｒ、Ｒ¹は、式（１−１）〜式（１−４）、式（２−１）、式（２−２）、式（３）におけるＲ、Ｒ¹と同一である。 The polymer (A) that can be used in the present invention is composed of a combination of the above repeating units. As monomers that generate these repeating units, the polymers represented by the formulas (1-1-m) to (1-4- m), an acrylic acid derivative ester represented by the formula (2-1-m), the formula (2-2m), and the formula (3-m).

In the above formula, R, R ¹ has the formula (1-1) to Formula (1-4), the formula (2-1), the formula (2-2), R in the formula (3), the same as R ¹ is there.

The polymer (A) is a repeating unit other than the formula (1-1) to the formula (1-4), the formula (2-1), the formula (2-2), and the formula (3) (hereinafter referred to as “others”). "Repeating unit").
Examples of the polymerizable unsaturated monomer that gives other repeating units include:
Norbornyl (meth) acrylate, isobornyl (meth) acrylate, tricyclodecanyl (meth) acrylate, tetracyclodecanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, adamantyl (meth) acrylate, (Meth) acrylic acid-3-hydroxy-1-adamantyl, (meth) acrylic acid-3,5-dihydroxy-1-adamantyl, (meth) acrylic acid-3-oxo-1-adamantyl, (meth) acrylic acid adamantyl (Meth) acrylic acid esters having a bridged hydrocarbon skeleton such as methyl;

(Meth) acrylic acid carboxynorbornyl, (meth) acrylic acid carboxytricyclodecanyl, (meth) acrylic acid carboxytetracyclodecanyl and other unsaturated carboxylic acid methyl (meth) acrylate, (meth) acrylic acid Ethyl, n-propyl (meth) acrylate, n-butyl (meth) acrylate, 2-methylpropyl (meth) acrylate, 1-methylpropyl (meth) acrylate, t-butyl (meth) acrylate, ( 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, cyclopropyl (meth) acrylate, cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate , (Meth) acrylic acid 4-methoxycyclohexyl, (meth) acrylic It does not have a bridged hydrocarbon skeleton such as 2-cyclopentyloxycarbonylethyl acid, 2-cyclohexyloxycarbonylethyl (meth) acrylate, 2- (4-methoxycyclohexyl) oxycarbonylethyl (meth) acrylate, etc. ) Acrylic esters;

α-hydroxymethyl acrylates such as methyl α-hydroxymethyl acrylate, ethyl α-hydroxymethyl acrylate, α-hydroxymethyl acrylate n-propyl, α-hydroxymethyl acrylate n-butyl;
Unsaturated nitrile compounds such as (meth) acrylonitrile, α-chloroacrylonitrile, crotonnitrile, maleinonitrile, fumaronitrile, mesaconnitrile, citraconenitrile, itaconnitrile;
Unsaturated amide compounds such as (meth) acrylamide, N, N-dimethyl (meth) acrylamide, crotonamide, maleamide, fumaramide, mesaconamide, citraconamide, itaconamide;

Other nitrogen-containing vinyl compounds such as N- (meth) acryloylmorpholine, N-vinyl-ε-caprolactam, N-vinylpyrrolidone, vinylpyridine, vinylimidazole;
Unsaturated carboxylic acids (anhydrides) such as (meth) acrylic acid, crotonic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride, citraconic acid, citraconic anhydride, mesaconic acid;
(Meth) acrylic acid 2-carboxyethyl, (meth) acrylic acid 2-carboxypropyl, (meth) acrylic acid 3-carboxypropyl, (meth) acrylic acid 4-carboxybutyl, (meth) acrylic acid 4-carboxycyclohexyl, etc. Carboxyl group-containing esters having no bridged hydrocarbon skeleton of the unsaturated carboxylic acid of

α- (meth) acryloyloxy-β-methoxycarbonyl-γ-butyrolactone, α- (meth) acryloyloxy-β-ethoxycarbonyl-γ-butyrolactone, α- (meth) acryloyloxy-β-n-propoxycarbonyl-γ -Butyrolactone, α- (meth) acryloyloxy-β-i-propoxycarbonyl-γ-butyrolactone, α- (meth) acryloyloxy-β-n-butoxycarbonyl-γ-butyrolactone, α- (meth) acryloyloxy-β -(2-methylpropoxy) carbonyl-γ-butyrolactone, α- (meth) acryloyloxy-β- (1-methylpropoxy) carbonyl-γ-butyrolactone, α- (meth) acryloyloxy-β-t-butoxycarbonyl- γ-butyrolactone, α- (meth) acryloyl Oxy-β-cyclohexyloxycarbonyl-γ-butyrolactone, α- (meth) acryloyloxy-β- (4-t-butylcyclohexyloxy) carbonyl-γ-butyrolactone, α- (meth) acryloyloxy-β-phenoxycarbonyl- γ-butyrolactone, α- (meth) acryloyloxy-β- (1-ethoxyethoxy) carbonyl-γ-butyrolactone, α- (meth) acryloyloxy-β- (1-cyclohexyloxyethoxy) carbonyl-γ-butyrolactone, α -(Meth) acryloyloxy-β-t-butoxycarbonylmethoxycarbonyl-γ-butyrolactone, α- (meth) acryloyloxy-β-tetrahydrofuranyloxycarbonyl-γ-butyrolactone, α- (meth) acryloyloxy-β-tetrahi B pyranyl butyloxycarbonyl -γ- butyrolactone,

α-methoxycarbonyl-β- (meth) acryloyloxy-γ-butyrolactone, α-ethoxycarbonyl-β- (meth) acryloyloxy-γ-butyrolactone, α-n-propoxycarbonyl-β- (meth) acryloyloxy-γ -Butyrolactone, α-i-propoxycarbonyl-β- (meth) acryloyloxy-γ-butyrolactone, α-n-butoxycarbonyl-β- (meth) acryloyloxy-γ-butyrolactone, α- (2-methylpropoxy) carbonyl -Β- (meth) acryloyloxy-γ-butyrolactone, α- (1-methylpropoxy) carbonyl-β- (meth) acryloyloxy-γ-butyrolactone, α-t-butoxycarbonyl-β- (meth) acryloyloxy- γ-butyrolactone, α-cyclohexyloxy Carbonyl-β- (meth) acryloyloxy-γ-butyrolactone, α- (4-t-butylcyclohexyloxy) carbonyl-β- (meth) acryloyloxy-γ-butyrolactone, α-phenoxycarbonyl-β- (meth) acryloyl Oxy-γ-butyrolactone, α- (1-ethoxyethoxy) carbonyl-β- (meth) acryloyloxy-γ-butyrolactone, α- (1-cyclohexyloxyethoxy) carbonyl-β- (meth) acryloyloxy-γ-butyrolactone , Α-t-butoxycarbonylmethoxycarbonyl-β- (meth) acryloyloxy-γ-butyrolactone, α-tetrahydrofuranyloxycarbonyl-β- (meth) acryloyloxy-γ-butyrolactone, α-tetrahydropyranyloxycarbonyl-β (Meth) acryloyloxy -γ- butyrolactone, beta-(meth) acrylate having an acryloyloxy -β- methyl -δ- valeronitrile acid-dissociable group of the lactone, such as (meth) acryloyloxy lactone compounds;

α- (meth) acryloyloxy-γ-butyrolactone, β- (meth) acryloyloxy-γ-butyrolactone, α- (meth) acryloyloxy-β-fluoro-γ-butyrolactone, α- (meth) acryloyloxy-β- Hydroxy-γ-butyrolactone, α- (meth) acryloyloxy-β-methyl-γ-butyrolactone, α- (meth) acryloyloxy-β-ethyl-γ-butyrolactone, α- (meth) acryloyloxy-β, β- Dimethyl-γ-butyrolactone, α- (meth) acryloyloxy-β-methoxy-γ-butyrolactone, α-fluoro-β- (meth) acryloyloxy-γ-butyrolactone, α-hydroxy-β- (meth) acryloyloxy- γ-butyrolactone, α-methyl-β- (meth) acryloyloxy-γ-buty Lolactone, α-ethyl-β- (meth) acryloyloxy-γ-butyrolactone, α, α-dimethyl-β- (meth) acryloyloxy-γ-butyrolactone, α-methoxy-β- (meth) acryloyloxy-γ- Butyrolactone, α- (meth) acryloyloxy-δ-valerolactone, β- (meth) acryloyloxy-δ-valerolactone, δ- (meth) acryloyloxy-γ-valerolactone, δ- (meth) acryloyloxy-β -Methyl-γ-valerolactone, δ- (meth) acryloyloxy-β, β-dimethyl-γ-valerolactone, 2- (meth) acryloyloxy-5-oxo-4-oxatricyclo [4.2.1 .0 ^3,7] nonane, 2- (meth) acryloyloxy-9-methoxycarbonyl-5-oxo-4 Okisatorishiku [4.2.1.0 ^{3, 7]} nonane, 4- (meth) acryloyloxy-7-oxo-6-oxabicyclo [3.2.1] octane, 4- (meth) acryloyloxy-2-methoxy Carbonyl-7-oxo-6-oxabicyclo [3.2.1] octane, 8 (9)-(meth) acryloyloxy-3-oxo-4-oxatricyclo [5,2,1,0 ^2,6 ] Monofunctional monomers such as (meth) acryloyloxylactone compounds having no acid dissociable groups such as decane,

1,2-adamantanediol di (meth) acrylate, 1,3-adamantanediol di (meth) acrylate, 1,4-adamantanediol di (meth) acrylate, tricyclodecanyl dimethylol di (meth) acrylate, etc. A polyfunctional monomer having a bridged hydrocarbon skeleton;

Methylene glycol di (meth) acrylate, ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 2,5-dimethyl-2,5-hexanediol di ( (Meth) acrylate, 1,8-octanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, 1,4-bis (2-hydroxypropyl) benzenedi (meth) acrylate, 1,3-bis A polyfunctional monomer such as a polyfunctional monomer having no bridged hydrocarbon skeleton such as (2-hydroxypropyl) benzenedi (meth) acrylate can be exemplified.

Of these polymerizable unsaturated monomers giving other repeating units, (meth) acrylic acid esters having a bridged hydrocarbon skeleton are preferred.
More preferable polymerizable unsaturated monomers include (meth) acrylic acid-3-hydroxy-1-adamantyl, (meth) acrylic acid-3,5-dihydroxy-1-adamantyl, (meth) acrylic acid-3- Oxo-1-adamantyl, 2- (meth) acryloyloxy-5-oxo-4-oxatricyclo [4.2.1.0 ^3,7 ] nonane, 2- (meth) acryloyloxy-9-methoxycarbonyl- 5-oxo-4-oxatricyclo [4.2.1.0 ^3,7 ] nonane, 4- (meth) acryloyloxy-7-oxo-6-oxabicyclo [3.2.1] octane, 4- (Meth) acryloyloxy-2-methoxycarbonyl-7-oxo-6-oxabicyclo [3.2.1] octane, 8 (9)-(meth) acryloyloxy-3-oxo-4-o Kisatorishikuro [5,2,1,0 ^2,6] decane, and the like can be given.
In the polymer (A), other repeating units can be present alone or in combination of two or more.

In the polymer (A), the content of at least two or more kinds of repeating units selected from the group consisting of the repeating units (1) to (3) is relative to all the repeating units in the polymer constituting the resin. Each is 1 to 59 mol%, preferably 3 to 50 mol%, and the total thereof is preferably 5 to 80 mol%. In this case, if the total content of the repeating units selected from the repeating unit (1) to (3) group is less than 5 mol%, the contrast at the time of developing the resist cannot be obtained, the resolution is deteriorated, and development defects are caused. On the other hand, if it exceeds 80 mol%, the contrast to the developer is improved, but the decrease in developability tends to be remarkably deteriorated.
Furthermore, the content of other repeating units is usually 95 mol% or less, preferably 80 mol% or less, based on all repeating units.

The polymer (A) that can be used in the present invention is polymerized by living radical polymerization using a chain transfer agent represented by the formula (X-1) in addition to the radical polymerization initiator.
In order to achieve a sufficient polymerization rate, it is necessary to add a sufficiently high concentration of radical polymerization initiator. However, if the ratio between the amount of radical polymerization initiator and the amount of chain transfer agent is too high, radical-radical coupling reaction occurs and an undesirable non-living radical polymer is formed. Therefore, the obtained polymer has a molecular weight and molecular weight distribution. The part which has the characteristic which is not controlled in polymer characteristics, such as is included. The molar ratio between the radical polymerization initiator amount and the chain transfer agent amount is (1: 1) to (0.005: 1).

The polymerization operation can be synthesized by a usual method such as batch polymerization or dropping polymerization. For example, an acid dissociable group-containing polymer can be obtained by dissolving a necessary monomer amount in an organic solvent and polymerizing in the presence of a radical polymerization initiator and a chain transfer agent.
As the polymerization solvent, an organic solvent capable of dissolving the monomer, the radical polymerization initiator, and the chain transfer agent is used. Examples of the organic solvent include ketone solvents, ether solvents, aprotic polar solvents, ester solvents, aromatic solvents, and linear or cyclic aliphatic solvents. Examples of the ketone solvent include methyl ethyl ketone and acetone. Examples of ether solvents include alkoxyalkyl ethers such as methoxymethyl ether, ethyl ether, tetrahydrofuran, and 1,4-dioxane. Examples of the aprotic polar solvent include dimethylformamide and dimethyl sulfoxide. Examples of ester solvents include alkyl acetates such as ethyl acetate and methyl acetate. Aromatic solvents include alkylaryl solvents such as toluene, xylene, and halogenated aromatic solvents such as chlorobenzene. Examples of the aliphatic solvent include hexane and cyclohexane.
The polymerization temperature is 20 to 120 ° C, preferably 50 to 110 ° C, more preferably 60 to 100 ° C. Although polymerization may be performed even in a normal air atmosphere, polymerization in an inert gas atmosphere such as nitrogen or argon is preferable. The molecular weight of the polymer can be adjusted by controlling the ratio between the monomer amount and the chain transfer agent amount.
The polymerization time is generally 0.5 to 144 hours, preferably 1 to 72 hours, more preferably 2 to 24 hours.

また、上記チオカルボニルチオ誘導体基を除去して使用することができる。連鎖移動剤由来の残基は、例えば下記（５）式で示すように、過剰なラジカル重合開始剤を利用して除去できる。

以下その処理方法について説明する。 The polymer (A) obtained by the above living radical polymerization method has a residue derived from a chain transfer agent at the molecular chain end, as shown by the following formula (4). In the present invention, a polymer having a thiocarbonylthio derivative group as a residue can be used as the polymer (A).

Further, it can be used after removing the thiocarbonylthio derivative group. The residue derived from the chain transfer agent can be removed by using an excess radical polymerization initiator, as shown, for example, by the following formula (5).

The processing method will be described below.

The end treatment is performed on a resin solution. As the solvent that can be used, those mentioned in the above polymerization operation can be used.
Usable radical polymerization initiators can be used as long as radicals can be generated under the conditions of polymer end group treatment. Radical generation conditions include high energy radiation such as heat, light, gamma rays or electron beams.
Specific examples of the radical polymerization initiator include initiators such as peroxides and azo compounds. Although not particularly limited, specific radical polymerization initiators include t-butyl hydroperoxide, t-butyl perbenzoate, benzoyl peroxide, 2,2′-azobis (2,4-dimethylvaleronitrile), 2, Examples include 2'-azobisisobutyronitrile (AIBN), 1,1'-azobis (cyclohexanecarbonitrile), dimethyl-2,2'-azobisisobutyrate (MAIB), benzoin ether, benzophenone, and the like.
The polymer end treatment can be performed on the end product of the polymerization reaction after completion of the living radical polymerization reaction, or the polymer end treatment can be performed after the once produced polymer is purified.
In the terminal treatment reaction, the radical polymerization initiator can be added to the reaction vessel all at once or gradually. When adding gradually, you may divide and add in multiple times, or may add continuously.

When a thermal radical polymerization initiator is used, the temperature of the resin end group treatment reaction is about 20 to 200 ° C, preferably 40 to 150 ° C, more preferably 50 to 100 ° C. The reaction atmosphere is an inert atmosphere such as nitrogen or argon, or an air atmosphere. The pressure of the reaction can be normal pressure or increased pressure. The amount of the radical polymerization initiator is 1 to 800% mol, preferably 50 to 400% mol of the total number of moles of residues present in the polymer to be end-treated as the amount of radical generated by the radical polymerization initiator. Preferably, it can introduce | transduce so that it may become 100-300% mol, More preferably, it is 200-300% mol. If a more complete removal of the residue from the chain transfer agent is desired, an excess amount of radical polymerization initiator is used.
The reaction time for the terminal treatment is 0.5 to 72 hours, preferably 1 to 24 hours, more preferably 2 to 12 hours. Removal of residues such as thiogroups from the polymer ends is at least 50%, preferably at least 75%, more preferably 85%, even more preferably 95%. The end-treated polymer is replaced at the end with new radical species, such as radical initiator fragments derived from the radical initiator used in the end-treatment reaction. The resulting polymer has a new group at the end and can be used according to the application.
In addition, the polymer terminal treatment can remove the residue derived from the chain transfer agent by the method described in International Publication WO02 / 090397.

  In the present invention, a polymer (A) having a chain transfer agent-derived residue at the molecular chain end, a polymer (A) having no chain transfer agent-derived residue at the molecular chain end, and a chain at the molecular chain end. Any polymer (A) in which a part of the residue derived from the transfer agent remains can be used.

The polymer (A) that can be used in the present invention is naturally low in impurities such as halogen and metal, but the residual monomer and oligomer components are not more than predetermined values, for example, 0.1% by weight or less by HPLC. It is preferable that there is a radiation-sensitive composition that can be used as a resist that not only can further improve sensitivity, resolution, process stability, pattern shape, etc. as a resist, but also does not change over time such as foreign matter in liquid or sensitivity. can get.
Examples of the method for purifying the polymer (A) include the following methods. As a method for removing impurities such as metals, the metal is chelated and removed by adsorbing the metal in the resin solution using a zeta potential filter or by washing the resin solution with an acidic aqueous solution such as oxalic acid or sulfonic acid. And the like. In addition, as a method of removing residual monomer and oligomer components below the specified value, liquid-liquid extraction method that removes residual monomer and oligomer components by combining water washing and an appropriate solvent, those with a specific molecular weight or less Refining method in the solution state such as ultrafiltration that extracts and removes only the polymer, and removing the residual monomer by coagulating the polymer in the poor solvent by dropping the polymer (A) solution into the poor solvent There are a reprecipitation method and a purification method in a solid state such as washing the filtered polymer slurry with a poor solvent. Moreover, these methods can also be combined. The poor solvent used in the reprecipitation method depends on the physical properties of the polymer (A) to be purified and cannot be generally exemplified. The poor solvent is appropriately selected.

The weight average molecular weight in terms of polystyrene (hereinafter referred to as “Mw”) by gel permeation chromatography (GPC) of the polymer (A) is usually 2,000 to 30,000, preferably 3,000 to 20,000. More preferably, it is 3,000 to 12,000. In this case, if the Mw of the polymer (A) is less than 2,000, the heat resistance when the resist is formed tends to decrease, whereas if it exceeds 30,000, the developability when the resist is formed tends to decrease. There is.
The ratio (Mw / Mn) of the polymer (A) Mw and the number average molecular weight in terms of polystyrene (hereinafter referred to as “Mn”) by gel permeation chromatography (GPC) is usually 1 to 2, preferably Is 1 to 1.6.
The polymer (A) is preferably as less as possible as impurities such as halogen and metal. Thereby, the sensitivity, resolution, process stability, pattern profile, etc. when used as a resist can be further improved. Examples of the purification method of the polymer (A) include chemical purification methods such as washing with water and liquid-liquid extraction, and combinations of these chemical purification methods and physical purification methods such as ultrafiltration and centrifugation. Can be mentioned.
In the present invention, the polymer (A) can be used alone or in combination of two or more.

A radiation-sensitive resin composition is obtained by using the polymer (A) as an acid-dissociable group-containing resin and combining with an acid generator (B) that is a component that generates an acid upon irradiation with radiation.
The acid generator (B) dissociates the acid dissociable groups present in the polymer (A) by the action of the acid generated by exposure, and as a result, the exposed portion of the resist film becomes readily soluble in an alkali developer, It has the effect of forming a positive resist pattern.
Examples of the acid generator (B) in the present invention include onium salts such as sulfonium salts and iodonium salts, organic halogen compounds, and sulfone compounds such as disulfones and diazomethane sulfones.
Preferred examples of the acid generator include triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium nonafluoro-n-butanesulfonate, triphenylsulfonium perfluoro-n-octanesulfonate, triphenylsulfonium 2-bicyclo [2.2.1]. ] Triphenylsulfonium salt compounds such as hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate and triphenylsulfonium camphorsulfonate;

  4-cyclohexylphenyldiphenylsulfonium trifluoromethanesulfonate, 4-cyclohexylphenyldiphenylsulfonium nonafluoro-n-butanesulfonate, 4-cyclohexylphenyldiphenylsulfonium perfluoro-n-octanesulfonate, 4-cyclohexylphenyldiphenylsulfonium 2-bicyclo [2. 2.1] 4-cyclohexylphenyldiphenylsulfonium salt compounds such as hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate and 4-cyclohexylphenyldiphenylsulfonium camphorsulfonate;

  4-methanesulfonylphenyldiphenylsulfonium trifluoromethanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium nonafluoro-n-butanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium perfluoro-n-octanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium 2- 4-cyclohexylphenyldiphenylsulfonium salt compounds such as bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium camphorsulfonate;

  Diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-n-butanesulfonate, diphenyliodonium perfluoro-n-octanesulfonate, diphenyliodonium 2-bicyclo [2.2.1] hept-2-yl-1,1,2, Diphenyliodonium salt compounds such as 2-tetrafluoroethanesulfonate and diphenyliodonium camphorsulfonate;

  Bis (4-t-butylphenyl) iodonium trifluoromethanesulfonate, bis (4-t-butylphenyl) iodonium nonafluoro-n-butanesulfonate, bis (4-t-butylphenyl) iodonium perfluoro-n-octanesulfonate, Bis (4-t-butylphenyl) iodonium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, bis (4-t-butylphenyl) iodonium camphor Bis (4-tert-butylphenyl) iodonium salt compounds such as sulfonate;

  1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium nonafluoro-n-butanesulfonate, (4-n-Butoxynaphthalen-1-yl) tetrahydrothiophenium perfluoro-n-octanesulfonate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium 2-bicyclo [2.2. 1] 1- (4-n-) such as hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium camphorsulfonate Butoxynaphthalen-1-yl) tetrahydrothiophenium salt compound;

  1- (6-n-butoxynaphthalen-2-yl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (6-n-butoxynaphthalen-2-yl) tetrahydrothiophenium nonafluoro-n-butanesulfonate, (6-n-Butoxynaphthalen-2-yl) tetrahydrothiophenium perfluoro-n-octanesulfonate, 1- (6-n-butoxynaphthalen-2-yl) tetrahydrothiophenium 2-bicyclo [2.2. 1] 1- (4-n-) such as hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 1- (6-n-butoxynaphthalen-2-yl) tetrahydrothiophenium camphorsulfonate Butoxynaphthalen-1-yl) tetrahydrothiophenium salt compound;

  1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium nonafluoro-n-butanesulfonate, (3,5-Dimethyl-4-hydroxyphenyl) tetrahydrothiophenium perfluoro-n-octanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium 2-bicyclo [2.2. 1] 1- (3,5- such as hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium camphorsulfonate Dimethyl-4-hydroxyphenyl) tetrahydrothiol Salt compound;

N- (trifluoromethanesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (nonafluoro-n-butanesulfonyloxy) bicyclo [2.2.1] hept -5-ene-2,3-dicarboximide, N- (perfluoro-n-octanesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- ( 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboxy imide, N- (2- (3- tetracyclo [4.4.0.1 ^2,5 .1 ^7,10] dodecanyl) -1,1-difluoroethane-sulfonyloxy) bicyclo [2.2.1] hept -5 -En Bicyclo [2.2.1] hept-5, such as 2,3-dicarboximide, N- (camphorsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide Examples include ene-2,3-dicarboximide compounds.

In this invention, an acid generator can be used individually or in mixture of 2 or more types.
The amount of the acid generator used is usually 0.1 to 30 parts by weight, preferably 0.1 to 20 parts per 100 parts by weight of the polymer (A), from the viewpoint of securing the sensitivity and developability as a resist. Parts by weight. In this case, if the amount of the acid generator used is less than 0.1 parts by weight, the sensitivity and developability tend to decrease. On the other hand, if it exceeds 30 parts by weight, the transparency to the radiation decreases, and a rectangular resist pattern. Tends to be difficult to obtain.

In the radiation sensitive resin composition of the present invention, an acid diffusion controller, an alicyclic additive having an acid dissociable group, an alicyclic additive not having an acid dissociable group, and a surfactant are included as necessary. Various additives such as a sensitizer can be blended.
The acid diffusion controller is a component having an action of controlling a diffusion phenomenon of an acid generated from an acid generator upon irradiation in a resist film and suppressing an undesirable chemical reaction in a non-irradiated region.
By blending such an acid diffusion control agent, the storage stability of the resulting radiation-sensitive resin composition is improved, the resolution as a resist is further improved, and the holding time from irradiation to development processing ( The change in the line width of the resist pattern due to the variation in PED) can be suppressed, and a composition having excellent process stability can be obtained.
The acid diffusion controller is preferably a nitrogen-containing organic compound whose basicity does not change by irradiation or heat treatment during the resist pattern formation step.

Examples of such nitrogen-containing organic compounds include “tertiary amine compounds”, “amide group-containing compounds”, “quaternary ammonium hydroxide compounds”, “nitrogen-containing heterocyclic compounds”, and the like.
Examples of the “tertiary amine compound” include triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n. -Tri (cyclo) alkylamines such as octylamine, cyclohexyldimethylamine, tricyclohexylamine; alkanolamines such as triethanolamine, diethanolaniline; N, N, N ', N'-tetramethylethylenediamine, N, N , N ′, N′-tetrakis (2-hydroxypropyl) ethylenediamine, 1,3-bis [1- (4-aminophenyl) -1-methylethyl] benzenetetramethylenediamine, 2,2-bis (4-amino) Phenyl) propane, 2- (3-aminophenyl) -2- (4-amino) Nophenyl) propane, 2- (4-aminophenyl) -2- (3-hydroxyphenyl) propane, 2- (4-aminophenyl) -2- (4-hydroxyphenyl) propane, 1,4-bis [1- (4-aminophenyl) -1-methylethyl] benzene, 1,3-bis [1- (4-aminophenyl) -1-methylethyl] benzene, bis (2-dimethylaminoethyl) ether, bis (2- Diethylaminoethyl) ether and the like.

  Examples of the “amide group-containing compound” include Nt-butoxycarbonyldi-n-octylamine, Nt-butoxycarbonyldi-n-nonylamine, Nt-butoxycarbonyldi-n-decylamine, N- t-butoxycarbonyldicyclohexylamine, Nt-butoxycarbonyl-1-adamantylamine, Nt-butoxycarbonyl-N-methyl-1-adamantylamine, N, N-di-t-butoxycarbonyl-1-adamantylamine N, N-di-t-butoxycarbonyl-N-methyl-1-adamantylamine, Nt-butoxycarbonyl-4,4′-diaminodiphenylmethane, N, N′-di-t-butoxycarbonylhexamethylenediamine N, N, N ′, N′-tetra-t-butoxycarbonylhexamethylene Diamine, N, N′-di-t-butoxycarbonyl-1,7-diaminoheptane, N, N′-di-t-butoxycarbonyl-1,8-diaminooctane, N, N′-di-t-butoxy Carbonyl-1,9-diaminononane, N, N′-di-t-butoxycarbonyl-1,10-diaminodecane, N, N′-di-t-butoxycarbonyl-1,12-diaminododecane, N, N ′ -Di-t-butoxycarbonyl-4,4'-diaminodiphenylmethane, Nt-butoxycarbonylbenzimidazole, Nt-butoxycarbonyl-2-methylbenzimidazole, Nt-butoxycarbonyl-2-phenylbenzimidazole Nt-butoxycarbonyl-pyrrolidine, Nt-butoxycarbonyl-piperidine, Nt-butoxycarbonyl- In addition to Nt-butoxycarbonyl group-containing amino compounds such as 4-hydroxy-piperidine, Nt-butoxycarbonyl-morpholine, formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, propionamide, benzamide, pyrrolidone, N-methylpyrrolidone and the like can be mentioned.

Examples of the “quaternary ammonium hydroxide compound” include tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetra-n-propylammonium hydroxide, tetra-n-butylammonium hydroxide, and the like.
Examples of the “nitrogen-containing heterocyclic compound” include imidazoles such as imidazole, 4-methylimidazole, 1-benzyl-2-methylimidazole, 4-methyl-2-phenylimidazole, benzimidazole, 2-phenylbenzimidazole; In addition to piperazines such as piperazine and 1- (2-hydroxyethyl) piperazine, pyrazine, pyrazole, pyridazine, quinosaline, purine, pyrrolidine, piperidine, 3-piperidino-1,2-propanediol, morpholine, 4-methylmorpholine, Examples include 1,4-dimethylpiperazine, 1,4-diazabicyclo [2.2.2] octane.

  Of the above nitrogen-containing heterocyclic compounds, tertiary amine compounds, amide group-containing compounds, and nitrogen-containing heterocyclic compounds are preferable, and among the amide group-containing compounds, Nt-butoxycarbonyl group-containing amino compounds are preferable, including Among the nitrogen heterocyclic compounds, imidazoles are preferable.

  The acid diffusion control agents can be used alone or in admixture of two or more. The compounding amount of the acid diffusion controller is usually 15 parts by weight or less, preferably 10 parts by weight or less, and more preferably 5 parts by weight or less with respect to 100 parts by weight of the polymer (A). In this case, when the compounding amount of the acid diffusion controller exceeds 15 parts by weight, the sensitivity as a resist and the developability of the radiation irradiated part tend to be lowered. If the amount of the acid diffusion controller is less than 0.001 part by weight, the pattern shape and dimensional fidelity as a resist may be lowered depending on the process conditions.

In addition, an alicyclic additive having an acid dissociable group or an alicyclic additive having no acid dissociable group is a component that further improves dry etching resistance, pattern shape, adhesion to a substrate, and the like. It is.
Examples of such alicyclic additives include 1-adamantanecarboxylic acid t-butyl, 1-adamantanecarboxylic acid t-butoxycarbonylmethyl, 1-adamantanecarboxylic acid α-butyrolactone ester, 1,3-adamantane dicarboxylic acid diester. -T-butyl, 1-adamantane acetate t-butyl, 1-adamantane acetate t-butoxycarbonylmethyl, 1,3-adamantanediacetate di-t-butyl, 2,5-dimethyl-2,5-di (adamantylcarbonyl) Adamantane derivatives such as oxy) hexane; deoxycholate t-butyl, deoxycholate t-butoxycarbonylmethyl, deoxycholate 2-ethoxyethyl, deoxycholate 2-cyclohexyloxyethyl, deoxycholate 3-oxocyclohexyl, Deoxychol Deoxycholic acid esters such as tetrahydropyranyl and deoxycholic acid mevalonolactone ester; lithocholic acid t-butyl, lithocholic acid t-butoxycarbonylmethyl, lithocholic acid 2-ethoxyethyl, lithocholic acid 2-cyclohexyloxyethyl, lithocholic acid Lithocholic acid esters such as 3-oxocyclohexyl, lithocholic acid tetrahydropyranyl, lithocholic acid mevalonolactone ester; dimethyl adipate, diethyl adipate, dipropyl adipate, di-n-butyl adipate, di-t-butyl adipate, etc. And alkyl carboxylic acid esters.
These alicyclic additives can be used alone or in admixture of two or more. The compounding quantity of an alicyclic additive is 50 parts weight or less normally with respect to 100 weight part of polymers (A), Preferably it is 30 parts weight or less. In this case, when the blending amount of the alicyclic additive exceeds 50 parts by weight, the heat resistance as a resist tends to decrease.

Further, the surfactant as an additive is a component having an effect of improving coating property, striation, developability and the like.
Examples of such surfactants include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene n-octylphenyl ether, polyoxyethylene n-nonylphenyl ether, and polyethylene glycol dilaurate. In addition to nonionic surfactants such as polyethylene glycol distearate, KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.), Polyflow No. 75, no. 95 (manufactured by Kyoeisha Chemical Co., Ltd.), Ftop EF301, EF303, EF352 (manufactured by Tochem Products), Megafax F171, F173 (manufactured by Dainippon Ink and Chemicals), Fluorad FC430, FC431 (manufactured by Sumitomo 3M Limited), Asahi Guard AG710, Surflon S-382, SC-101, SC-102, SC-103, SC-104, SC-105, SC-106 ( Asahi Glass Co., Ltd.).
These surfactants can be used alone or in admixture of two or more. The compounding amount of the surfactant is usually 2 parts by weight or less with respect to 100 parts by weight of the polymer (A).

Further, the sensitizer as an additive has an action of absorbing radiation energy and transmitting the energy to the acid generator, thereby increasing the amount of acid generated. The radiation-sensitive resin composition It has the effect of improving the apparent sensitivity.
Examples of such sensitizers include carbazoles, benzophenones, rose bengals, anthracenes, phenols and the like.
These sensitizers can be used alone or in admixture of two or more. The blending amount of the sensitizer is preferably 50 parts by weight or less with respect to 100 parts by weight of the polymer (A).
Furthermore, examples of additives other than those mentioned above include antihalation agents, adhesion assistants, storage stabilizers, antifoaming agents, and the like.
The radiation-sensitive resin composition of the present invention is usually dissolved in a solvent so that the total solid content is usually 3 to 50% by weight, preferably 5 to 25% by weight. A composition solution is prepared by filtering through a filter having a pore size of about 0.2 μm.
Examples of the solvent used in the preparation of the composition solution include linear or branched ketones such as 2-pentanone, 2-hexanone, 2-heptanone, and 2-octanone; cyclopentanone, cyclohexanone, and the like. Cyclic ketones; propylene glycol monoalkyl ether acetates such as propylene glycol monomethyl ether acetate and propylene glycol monoethyl ether acetate; 2-hydroxypropionate alkyls such as methyl 2-hydroxypropionate and ethyl 2-hydroxypropionate; In addition to alkyl 3-alkoxypropionates such as methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate and ethyl 3-ethoxypropionate,
Ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether, propylene glycol monoethyl ether, n-butyl acetate, methyl pyruvate , Ethyl pyruvate, N-methylpyrrolidone, γ-butyrolactone and the like.

  These solvents may be used alone or in admixture of two or more, but propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, 2-heptanone, cyclohexanone, γ-butyrolactone, ethyl 2-hydroxypropionate, 3-ethoxy It is preferable to contain at least one selected from ethyl propionate. However, cyclohexanone is an effective solvent from the viewpoint of solubility, but its use is preferably avoided as much as possible because of its toxicity.

The radiation sensitive resin composition of the present invention is particularly useful as a chemically amplified resist. In particular, it is useful as a positive resist that can reduce the line edge roughness of a pattern after development.
In a chemically amplified resist, the acid-dissociable group in the resin is dissociated by the action of the acid generated from the acid generator by radiation irradiation to generate a carboxyl group. The solubility becomes high, and the irradiated portion is dissolved and removed by an alkali developer, and a positive resist pattern is obtained.
When forming a resist pattern from the radiation-sensitive resin composition of the present invention, the composition solution is coated with, for example, a silicon wafer or aluminum by an appropriate application means such as spin coating, cast coating or roll coating. A resist film is formed by coating on a substrate such as a wafer, and in some cases, a heat treatment (hereinafter referred to as “PB”) is performed in advance, and then a predetermined resist pattern is formed on the resist film. Irradiate. Examples of radiation used at this time include ultraviolet rays, KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), F ₂ excimer laser (wavelength 157 nm), EUV (extreme ultraviolet light, wavelength 13 nm, etc.), etc. Far ultraviolet rays, charged particle beams such as electron beams, and X-rays such as synchrotron radiation can be appropriately selected and used. Of these, far ultraviolet rays and electron beams are preferred. Moreover, irradiation conditions, such as irradiation amount, are suitably selected according to the compounding composition of a radiation sensitive resin composition, the kind of each additive, etc.
In the present invention, PEB is preferably performed in order to stably form a high-precision fine pattern. By this PEB, the dissociation reaction of the acid dissociable organic group in the polymer (A) proceeds smoothly. The heating condition of PEB varies depending on the composition of the radiation sensitive resin composition, but is usually 30 to 200 ° C, preferably 50 to 170 ° C.

In the present invention, in order to maximize the potential of the radiation-sensitive resin composition, for example, as disclosed in Japanese Patent Publication No. 6-12458, an organic or inorganic substrate is used. An antireflection film can also be formed, and in order to prevent the influence of basic impurities contained in the environmental atmosphere, as disclosed in, for example, JP-A-5-188598, A protective film can be provided on the substrate, or these techniques can be used in combination.
Next, the irradiated resist film is developed using an alkali developer to form a predetermined resist pattern.
As the alkaline developer, for example, an alkaline aqueous solution in which tetramethylammonium hydroxide is dissolved is preferable.
The concentration of the alkaline aqueous solution is usually 10% by weight or less. In this case, if the concentration of the alkaline aqueous solution exceeds 10% by weight, the non-irradiated part may be dissolved in the developer, which is not preferable.
In addition, an appropriate amount of a surfactant or the like can be added to the alkaline aqueous solution. In addition, after developing with an alkali developing solution, it is generally washed with water and dried.

Hereinafter, the present invention will be described more specifically with reference to synthesis examples of the polymer (A) and examples of the radiation-sensitive resin composition. However, the present invention is not limited to these examples. Here, the part is based on weight unless otherwise specified.
Each measurement and evaluation in the synthesis examples and the examples was performed as follows.

The ¹³ C-NMR analysis of the polymers (A-1) to (A-14) was performed using “JNM-EX270” manufactured by JEOL Ltd. and using CDCL3 as a measurement solvent. In addition, Mw was monodispersed under the analysis conditions of a GPC column (2 G2000HXL, 1 G3000HXL, 1 G4000HXL) manufactured by Tosoh Corporation, with a flow rate of 1.0 ml / min, elution solvent tetrahydrofuran, and column temperature of 40 ° C. It was measured by gel permeation chromatography (GPC) using polystyrene as a standard.
Moreover, the absorption coefficient in 300 nm prepared polymer (A-1)-(A-14) so that it might become 0.50-1.00 g / L (chloroform solution), and the ultraviolet visible light photometer ((stock) ) Absorbance at 300 nm was measured by JASCO, and the Gram extinction coefficient was calculated.

化合物（６−１）４８．８４ｇ（５０モル％）、化合物（６−２）３８．２１ｇ（３５モル％）、化合物（６−３）１２．９４ｇ（１５モル％）を２−ブタノン１８７ｇに溶解した単量体溶液（１）、ジメチル２，２'−アゾビス（２−メチルプロピオネート）４．２２ｇを２−ブタノン８０ｇに溶解した溶液（２）を準備し、さらに前述したＣＴＡ−３で表される化合物を３．５２ｇ、２−ブタノンを１９ｇ投入した１０００ｍｌの三口フラスコに前に準備した単量体溶液（１）２８．７７ｇ、溶液（２）５．２９ｇを投入し、その後減圧置換法にて窒素パージする。窒素パージの後、反応釜を攪拌しながら８０℃に加熱し、１５分後、単量体溶液（１）２５８．９８ｇ、溶液（２）２４．６４ｇを送液ポンプを用いて３時間かけて滴下した。滴下終了後さらに４時間攪拌した。重合終了後、重合溶液は放冷することにより３０℃以下に冷却した。その後ジメチル２，２'−アゾビス（２−メチルプロピオネート）１０．１２ｇを重合溶液に加え、８０℃に加熱し３時間攪拌した。反応終了後、溶液は放冷し３０℃以下に冷却し、４０００ｇのイソプロピルアルコールへ投入し、析出した白色粉末をろ別する。ろ別された白色粉末を２度２０００ｇのイソプロピルアルコールにてスラリー上で洗浄した後、ろ別し、６０℃にて１７時間乾燥し、白色粉末の重合体を得た（８０ｇ、収率８０％）。この重合体はＭｗが７４００、¹³Ｃ-ＮＭＲ分析の結果、化合物（６−１）、化合物（６−２）、化合物（６−３）で表される繰り返し単位、各繰り返し単位の含有率が５４．１：３２．１：１３．８（モル％）の共重合体であった。また、３００ｎｍにおける吸光係数は０．０９（Ｌ／ｇ・ｃｍ）であった。この重合体を重合体（Ａ−１）とする。 Synthesis example 1

Compound (6-1) 48.84 g (50 mol%), compound (6-2) 38.21 g (35 mol%), compound (6-3) 12.94 g (15 mol%) into 2-butanone 187 g A dissolved monomer solution (1) and a solution (2) in which 4.22 g of dimethyl 2,2′-azobis (2-methylpropionate) was dissolved in 80 g of 2-butanone were prepared, and CTA-3 described above was further prepared. The monomer solution (1) (28.77 g) and the solution (2) (5.29 g) prepared previously were charged into a 1000 ml three-necked flask charged with 3.52 g of the compound represented by the formula (2) and 19 g of 2-butanone, and then reduced in pressure. Purge nitrogen with the replacement method. After purging with nitrogen, the reaction kettle was heated to 80 ° C. with stirring. After 15 minutes, 258.98 g of monomer solution (1) and 24.64 g of solution (2) were added over 3 hours using a liquid feed pump. It was dripped. After completion of the dropwise addition, the mixture was further stirred for 4 hours. After completion of the polymerization, the polymerization solution was allowed to cool and then cooled to 30 ° C. or lower. Thereafter, 10.12 g of dimethyl 2,2′-azobis (2-methylpropionate) was added to the polymerization solution, heated to 80 ° C. and stirred for 3 hours. After completion of the reaction, the solution is allowed to cool, cooled to 30 ° C. or lower, poured into 4000 g of isopropyl alcohol, and the precipitated white powder is filtered off. The filtered white powder was washed twice with 2000 g of isopropyl alcohol on the slurry, filtered, and dried at 60 ° C. for 17 hours to obtain a white powder polymer (80 g, yield 80%). ). This polymer has Mw of 7400, and as a result of ¹³ C-NMR analysis, the repeating unit represented by compound (6-1), compound (6-2) and compound (6-3), and the content of each repeating unit are It was a copolymer of 54.1: 32.1: 13.8 (mol%). The extinction coefficient at 300 nm was 0.09 (L / g · cm). This polymer is referred to as “polymer (A-1)”.

化合物（７−１）５５．６５ｇ（６０モル％）、化合物（７−２）１７．１７ｇ（１５モル％）、化合物（７−３）２７．１６ｇ（２５モル％）を２−ブタノン１８７ｇに溶解した単量体溶液（１）、ジメチル２，２'−アゾビス（２−メチルプロピオネート）４．４２ｇを２−ブタノン６４ｇに溶解した溶液（２）を準備し、さらに前述したＣＴＡ−３で表される化合物を３．５２ｇ、２−ブタノンを１９ｇ投入した１０００ｍｌの三口フラスコに前に準備した単量体溶液（１）２８．７７ｇ、溶液（２）５．２９ｇを投入し、その後減圧置換法にて窒素パージする。窒素パージの後、反応釜を攪拌しながら８０℃に加熱し、１５分後、単量体溶液（１）２５８．９８ｇ、溶液（２）３０．８０ｇを送液ポンプを用いて３時間かけて滴下した。滴下終了後さらに４時間攪拌した。重合終了後、重合溶液は放冷することにより３０℃以下に冷却した。その後ジメチル２，２'−アゾビス（２−メチルプロピオネート）９．６１ｇを重合溶液に加え、８０℃に加熱し３時間攪拌した。反応終了後、溶液は放冷し３０℃以下に冷却し、４０００ｇのイソプロピルアルコールへ投入し、析出した白色粉末をろ別する。ろ別された白色粉末を２度２０００ｇのイソプロピルアルコールにてスラリー上で洗浄した後、ろ別し、６０℃にて１７時間乾燥し、白色粉末の重合体を得た（７８ｇ、収率７８％）。この重合体はＭｗが５９００であり、¹³Ｃ-ＮＭＲ分析の結果、化合物（７−１）、化合物（７−２）、化合物（７−３）で表される繰り返し単位、各繰り返し単位の含有率が５８．９：１４．５：２６．６（モル％）の共重合体であった。また、３００ｎｍにおける吸光係数は０．１０（Ｌ／ｇ・ｃｍ）であった。この重合体を重合体（Ａ−２）とする。 Synthesis example 2

Compound (7-1) 55.65 g (60 mol%), compound (7-2) 17.17 g (15 mol%), compound (7-3) 27.16 g (25 mol%) into 2-butanone 187 g A dissolved monomer solution (1) and a solution (2) in which 4.42 g of dimethyl 2,2′-azobis (2-methylpropionate) was dissolved in 64 g of 2-butanone were prepared, and CTA-3 described above was further prepared. The monomer solution (1) (28.77 g) and the solution (2) (5.29 g) prepared previously were charged into a 1000 ml three-necked flask charged with 3.52 g of the compound represented by the formula (2) and 19 g of 2-butanone, and then reduced in pressure. Purge nitrogen with the replacement method. After purging with nitrogen, the reaction kettle was heated to 80 ° C. with stirring. After 15 minutes, 258.98 g of monomer solution (1) and 30.80 g of solution (2) were added over 3 hours using a feed pump. It was dripped. After completion of the dropwise addition, the mixture was further stirred for 4 hours. After completion of the polymerization, the polymerization solution was allowed to cool and then cooled to 30 ° C. or lower. Thereafter, 9.61 g of dimethyl 2,2′-azobis (2-methylpropionate) was added to the polymerization solution, heated to 80 ° C. and stirred for 3 hours. After completion of the reaction, the solution is allowed to cool, cooled to 30 ° C. or lower, poured into 4000 g of isopropyl alcohol, and the precipitated white powder is filtered off. The filtered white powder was washed twice with 2000 g of isopropyl alcohol on the slurry, filtered, and dried at 60 ° C. for 17 hours to obtain a white powder polymer (78 g, yield 78%). ). This polymer has Mw of 5900, and as a result of ¹³ C-NMR analysis, compound (7-1), compound (7-2), repeating unit represented by compound (7-3), inclusion of each repeating unit The ratio was 58.9: 14.5: 26.6 (mol%). The extinction coefficient at 300 nm was 0.10 (L / g · cm). This polymer is referred to as “polymer (A-2)”.

化合物（８−１）４０．００ｇ（４０モル％）、化合物（８−２）４８．５１ｇ（４６モル％）、化合物（８−３）１１．４８ｇ（１４モル％）を２−ブタノン１８７ｇに溶解した単量体溶液（１）、ジメチル２，２'−アゾビス（２−メチルプロピオネート）４．２２ｇを２−ブタノン８０ｇに溶解した溶液（２）を準備し、さらに前述したＣＴＡ−３で表される化合物を３．５２ｇ、２−ブタノンを１９ｇ投入した１０００ｍｌの三口フラスコに前に準備した単量体溶液（１）２８．７７ｇ、溶液（２）５．２９ｇを投入し、その後減圧置換法にて窒素パージする。窒素パージの後、反応釜を攪拌しながら８０℃に加熱し、１５分後、単量体溶液（１）２５８．９８ｇ、溶液（２）２４．６４ｇを送液ポンプを用いて３時間かけて滴下した。滴下終了後さらに４時間攪拌した。重合終了後、重合溶液は放冷することにより３０℃以下に冷却した。その後ジメチル２，２'−アゾビス（２−メチルプロピオネート）１０．３６ｇを重合溶液に加え、８０℃に加熱し３時間攪拌した。反応終了後、溶液は放冷し３０℃以下に冷却し、４０００ｇのイソプロピルアルコールへ投入し、析出した白色粉末をろ別する。ろ別された白色粉末を２度２０００ｇのイソプロピルアルコールにてスラリー上で洗浄した後、ろ別し、６０℃にて１７時間乾燥し、白色粉末の重合体を得た（８０ｇ、収率８０％）。この重合体はＭｗが６１００であり、¹³Ｃ-ＮＭＲ分析の結果、化合物（８−１）、化合物（８−２）、化合物（８−３）で表される繰り返し単位、各繰り返し単位の含有率が４５．９：３９．４：１４．７（モル％）の共重合体であった。また、３００ｎｍにおける吸光係数は０．１２（Ｌ／ｇ・ｃｍ）であった。この重合体を重合体（Ａ−３）とする。 Synthesis example 3

Compound (8-1) 40.00 g (40 mol%), compound (8-2) 48.51 g (46 mol%), compound (8-3) 11.48 g (14 mol%) to 2-butanone 187 g A dissolved monomer solution (1) and a solution (2) in which 4.22 g of dimethyl 2,2′-azobis (2-methylpropionate) was dissolved in 80 g of 2-butanone were prepared, and CTA-3 described above was further prepared. The monomer solution (1) (28.77 g) and the solution (2) (5.29 g) prepared previously were charged into a 1000 ml three-necked flask charged with 3.52 g of the compound represented by the formula (2) and 19 g of 2-butanone, and then reduced in pressure. Purge nitrogen with the replacement method. After purging with nitrogen, the reaction kettle was heated to 80 ° C. with stirring. After 15 minutes, 258.98 g of monomer solution (1) and 24.64 g of solution (2) were added over 3 hours using a liquid feed pump. It was dripped. After completion of the dropwise addition, the mixture was further stirred for 4 hours. After completion of the polymerization, the polymerization solution was allowed to cool and then cooled to 30 ° C. or lower. Thereafter, 10.36 g of dimethyl 2,2′-azobis (2-methylpropionate) was added to the polymerization solution, heated to 80 ° C. and stirred for 3 hours. After completion of the reaction, the solution is allowed to cool, cooled to 30 ° C. or lower, poured into 4000 g of isopropyl alcohol, and the precipitated white powder is filtered off. The filtered white powder was washed twice with 2000 g of isopropyl alcohol on the slurry, filtered, and dried at 60 ° C. for 17 hours to obtain a white powder polymer (80 g, yield 80%). ). This polymer has Mw of 6100, and as a result of ¹³ C-NMR analysis, the compound (8-1), the compound (8-2), the repeating unit represented by the compound (8-3), the content of each repeating unit It was a copolymer having a ratio of 45.9: 39.4: 14.7 (mol%). The extinction coefficient at 300 nm was 0.12 (L / g · cm). This polymer is referred to as “polymer (A-3)”.

化合物（９−１）５２．５２ｇ（５５モル％）、化合物（９−２）１０．０７ｇ（１０モル％）、化合物（９−３）３７．３７ｇ（３５モル％）を２−ブタノン１８７ｇに溶解した単量体溶液（１）、ジメチル２，２'−アゾビス（２−メチルプロピオネート）４．２２ｇを２−ブタノン８０ｇに溶解した溶液（２）を準備し、さらに前述したＣＴＡ−３で表される化合物を３．５２ｇ、２−ブタノンを１９ｇ投入した１０００ｍｌの三口フラスコに前に準備した単量体溶液（１）２８．７７ｇ、溶液（２）５．２９ｇを投入し、その後減圧置換法にて窒素パージする。窒素パージの後、反応釜を攪拌しながら８０℃に加熱し、１５分後、単量体溶液（１）２５８．９８ｇ、溶液（２）３０．８０ｇを送液ポンプを用いて３時間かけて滴下した。滴下終了後さらに４時間攪拌した。重合終了後、重合溶液は放冷することにより３０℃以下に冷却した。その後ジメチル２，２'−アゾビス（２−メチルプロピオネート）９．９０ｇを重合溶液に加え、８０℃に加熱し３時間攪拌した。反応終了後、溶液は放冷し３０℃以下に冷却し、４０００ｇのイソプロピルアルコールへ投入し、析出した白色粉末をろ別する。ろ別された白色粉末を２度２０００ｇのイソプロピルアルコールにてスラリー上で洗浄した後、ろ別し、６０℃にて１７時間乾燥し、白色粉末の重合体を得た（７５ｇ、収率７５％）。この重合体はＭｗが５８００であり、¹³Ｃ-ＮＭＲ分析の結果、化合物（９−１）、化合物（９−２）、化合物（９−３）で表される繰り返し単位、各繰り返し単位の含有率が５５．５：８．５：３６．０（モル％）の共重合体であった。また、３００ｎｍにおける吸光係数は０．１１（Ｌ／ｇ・ｃｍ）であった。この重合体を重合体（Ａ−４）とする。 Synthesis example 4

Compound (9-1) 52.52 g (55 mol%), compound (9-2) 10.07 g (10 mol%), compound (9-3) 37.37 g (35 mol%) into 2-butanone 187 g A dissolved monomer solution (1) and a solution (2) in which 4.22 g of dimethyl 2,2′-azobis (2-methylpropionate) was dissolved in 80 g of 2-butanone were prepared, and CTA-3 described above was further prepared. The monomer solution (1) (28.77 g) and the solution (2) (5.29 g) prepared previously were charged into a 1000 ml three-necked flask charged with 3.52 g of the compound represented by the formula (2) and 19 g of 2-butanone, and then reduced in pressure. Purge nitrogen with the replacement method. After purging with nitrogen, the reaction kettle was heated to 80 ° C. with stirring. After 15 minutes, 258.98 g of monomer solution (1) and 30.80 g of solution (2) were added over 3 hours using a feed pump. It was dripped. After completion of the dropwise addition, the mixture was further stirred for 4 hours. After completion of the polymerization, the polymerization solution was allowed to cool and then cooled to 30 ° C. or lower. Thereafter, 9.90 g of dimethyl 2,2′-azobis (2-methylpropionate) was added to the polymerization solution, heated to 80 ° C. and stirred for 3 hours. After completion of the reaction, the solution is allowed to cool, cooled to 30 ° C. or lower, poured into 4000 g of isopropyl alcohol, and the precipitated white powder is filtered off. The filtered white powder was washed twice with 2000 g of isopropyl alcohol on the slurry, filtered, and dried at 60 ° C. for 17 hours to obtain a white powder polymer (75 g, yield 75%). ). This polymer has Mw of 5800, and as a result of ¹³ C-NMR analysis, the compound (9-1), the compound (9-2), the repeating unit represented by the compound (9-3), the content of each repeating unit It was a copolymer having a ratio of 55.5: 8.5: 36.0 (mol%). The extinction coefficient at 300 nm was 0.11 (L / g · cm). This polymer is referred to as “polymer (A-4)”.

Synthesis example 5
Compound (8-1) 50.16 g (50 mol%), compound (8-2) 39.14 g (37 mol%), compound (8-3) 10.69 g (13 mol%) to 2-butanone 187 g A dissolved monomer solution (1) and a solution (2) in which 4.22 g of dimethyl 2,2′-azobis (2-methylpropionate) was dissolved in 80 g of 2-butanone were prepared, and CTA-3 described above was further prepared. The monomer solution (1) (28.77 g) and the solution (2) (5.29 g) prepared previously were charged into a 1000 ml three-necked flask charged with 3.52 g of the compound represented by the formula (2) and 19 g of 2-butanone, and then reduced in pressure. Purge nitrogen with the replacement method. After purging with nitrogen, the reaction kettle was heated to 80 ° C. with stirring. After 15 minutes, 258.98 g of monomer solution (1) and 30.80 g of solution (2) were added over 3 hours using a feed pump. It was dripped. After completion of the dropwise addition, the mixture was further stirred for 4 hours. After completion of the polymerization, the polymerization solution was allowed to cool to cool to 30 ° C. or lower. Thereafter, 10.39 g of dimethyl 2,2′-azobis (2-methylpropionate) was added to the polymerization solution, heated to 80 ° C. and stirred for 3 hours. After completion of the reaction, the solution is allowed to cool, cooled to 30 ° C. or lower, poured into 4000 g of isopropyl alcohol, and the precipitated white powder is filtered off. The filtered white powder was washed twice with 2000 g of isopropyl alcohol on the slurry, filtered, and dried at 60 ° C. for 17 hours to obtain a white powder polymer (80 g, yield 80%). ). This polymer has Mw of 6200, and as a result of ¹³ C-NMR analysis, the compound (8-1), the compound (8-2), the repeating unit represented by the compound (8-3), and the content of each repeating unit It was a copolymer having a ratio of 54.1: 31.9: 13.9 (mol%). The extinction coefficient at 300 nm was 0.10 (L / g · cm). This polymer is referred to as “polymer (A-5)”.

化合物（１０−１）４４．８５ｇ（４７モル％）、化合物（１０−２）３８．３４ｇ（３８モル％）、化合物（１０−３）１６．９０ｇ（１５モル％）を２−ブタノン１８７ｇに溶解した単量体溶液（１）、ジメチル２，２'−アゾビス（２−メチルプロピオネート）４．２２ｇを２−ブタノン８０ｇに溶解した溶液（２）を準備し、さらに前述したＣＴＡ−３で表される化合物を３．５２ｇ、２−ブタノンを１９ｇ投入した１０００ｍｌの三口フラスコに前に準備した単量体溶液（１）２８．７７ｇ、溶液（２）５．２９ｇを投入し、その後減圧置換法にて窒素パージする。窒素パージの後、反応釜を攪拌しながら８０℃に加熱し、１５分後、単量体溶液（１）２５８．９８ｇ、溶液（２）３０．８０ｇを送液ポンプを用いて３時間かけて滴下した。滴下終了後さらに４時間攪拌した。重合終了後、重合溶液は放冷することにより３０℃以下に冷却した。その後ジメチル２，２'−アゾビス（２−メチルプロピオネート）９．８８ｇを重合溶液に加え、８０℃に加熱し３時間攪拌した。反応終了後、溶液は放冷し３０℃以下に冷却し、４０００ｇのイソプロピルアルコールへ投入し、析出した白色粉末をろ別する。ろ別された白色粉末を２度２０００ｇのイソプロピルアルコールにてスラリー上で洗浄した後、ろ別し、６０℃にて１７時間乾燥し、白色粉末の重合体を得た（７０ｇ、収率７０％）。この重合体はＭｗが６２００であり、¹³Ｃ-ＮＭＲ分析の結果、化合物（１０−１）、化合物（１０−２）、化合物（１０−３）で表される繰り返し単位、各繰り返し単位の含有率が４９．１：３７．６：１３．３（モル％）の共重合体であった。また、３００ｎｍにおける吸光係数は０．１０（Ｌ／ｇ・ｃｍ）であった。この重合体を重合体（Ａ−６）とする。 Synthesis Example 6

Compound (10-1) 44.85 g (47 mol%), compound (10-2) 38.34 g (38 mol%), compound (10-3) 16.90 g (15 mol%) into 2-butanone 187 g A dissolved monomer solution (1) and a solution (2) in which 4.22 g of dimethyl 2,2′-azobis (2-methylpropionate) was dissolved in 80 g of 2-butanone were prepared, and CTA-3 described above was further prepared. The monomer solution (1) (28.77 g) and the solution (2) (5.29 g) prepared previously were charged into a 1000 ml three-necked flask charged with 3.52 g of the compound represented by the formula (2) and 19 g of 2-butanone, and then reduced in pressure. Purge nitrogen with the replacement method. After purging with nitrogen, the reaction kettle was heated to 80 ° C. with stirring. After 15 minutes, 258.98 g of monomer solution (1) and 30.80 g of solution (2) were added over 3 hours using a feed pump. It was dripped. After completion of the dropwise addition, the mixture was further stirred for 4 hours. After completion of the polymerization, the polymerization solution was allowed to cool and then cooled to 30 ° C. or lower. Thereafter, 9.88 g of dimethyl 2,2′-azobis (2-methylpropionate) was added to the polymerization solution, heated to 80 ° C. and stirred for 3 hours. After completion of the reaction, the solution is allowed to cool, cooled to 30 ° C. or lower, poured into 4000 g of isopropyl alcohol, and the precipitated white powder is filtered off. The filtered white powder was washed twice with 2000 g of isopropyl alcohol on the slurry, filtered, and dried at 60 ° C. for 17 hours to obtain a white powder polymer (70 g, yield 70%). ). This polymer has Mw of 6200, and as a result of ¹³ C-NMR analysis, compound (10-1), compound (10-2), repeating unit represented by compound (10-3), inclusion of each repeating unit It was a copolymer having a ratio of 49.1: 37.6: 13.3 (mol%). The extinction coefficient at 300 nm was 0.10 (L / g · cm). This polymer is referred to as “polymer (A-6)”.

化合物（１１−１）４６．０４ｇ（４７モル％）、化合物（１１−２）３９．２５ｇ（３８モル％）、化合物（１１−３）１４．７０ｇ（１５モル％）を２−ブタノン１８７ｇに溶解した単量体溶液（１）、ジメチル２，２'−アゾビス（２−メチルプロピオネート）４．２２ｇを２−ブタノン８０ｇに溶解した溶液（２）を準備し、さらに前述したＣＴＡ−３で表される化合物を３．５２ｇ、２−ブタノンを１９ｇ投入した１０００ｍｌの三口フラスコに前に準備した単量体溶液（１）２８．７７ｇ、溶液（２）５．２９ｇを投入し、その後減圧置換法にて窒素パージする。窒素パージの後、反応釜を攪拌しながら８０℃に加熱し、１５分後、単量体溶液（１）２５８．９８ｇ、溶液（２）３０．８０ｇを送液ポンプを用いて３時間かけて滴下した。滴下終了後さらに４時間攪拌した。重合終了後、重合溶液は放冷することにより３０℃以下に冷却した。その後ジメチル２，２'−アゾビス（２−メチルプロピオネート）１０．１５ｇを重合溶液に加え、８０℃に加熱し３時間攪拌した。反応終了後、溶液は放冷し３０℃以下に冷却し、４０００ｇのイソプロピルアルコールへ投入し、析出した白色粉末をろ別する。ろ別された白色粉末を２度２０００ｇのイソプロピルアルコールにてスラリー上で洗浄した後、ろ別し、６０℃にて１７時間乾燥し、白色粉末の重合体を得た（７１ｇ、収率７１％）。この重合体はＭｗが６１００であり、¹³Ｃ-ＮＭＲ分析の結果、化合物（１１−１）、化合物（１１−２）、化合物（１１−３）で表される繰り返し単位、各繰り返し単位の含有率が４８．２：３９．０：１２．８（モル％）の共重合体であった。また、３００ｎｍにおける吸光係数は０．１１（Ｌ／ｇ・ｃｍ）であった。この重合体を重合体（Ａ−７）とする。 Synthesis example 7

Compound (11-1) 46.04 g (47 mol%), compound (11-2) 39.25 g (38 mol%), compound (11-3) 14.70 g (15 mol%) into 2-butanone 187 g A dissolved monomer solution (1) and a solution (2) in which 4.22 g of dimethyl 2,2′-azobis (2-methylpropionate) was dissolved in 80 g of 2-butanone were prepared, and CTA-3 described above was further prepared. The monomer solution (1) (28.77 g) and the solution (2) (5.29 g) prepared previously were charged into a 1000 ml three-necked flask charged with 3.52 g of the compound represented by the formula (2) and 19 g of 2-butanone, and then reduced in pressure. Purge nitrogen with the replacement method. After purging with nitrogen, the reaction kettle was heated to 80 ° C. with stirring. After 15 minutes, 258.98 g of monomer solution (1) and 30.80 g of solution (2) were added over 3 hours using a feed pump. It was dripped. After completion of the dropwise addition, the mixture was further stirred for 4 hours. After completion of the polymerization, the polymerization solution was allowed to cool and then cooled to 30 ° C. or lower. Thereafter, 10.15 g of dimethyl 2,2′-azobis (2-methylpropionate) was added to the polymerization solution, heated to 80 ° C. and stirred for 3 hours. After completion of the reaction, the solution is allowed to cool, cooled to 30 ° C. or lower, poured into 4000 g of isopropyl alcohol, and the precipitated white powder is filtered off. The filtered white powder was washed twice with 2000 g of isopropyl alcohol on the slurry, filtered, and dried at 60 ° C. for 17 hours to obtain a white powder polymer (71 g, yield 71%). ). This polymer has Mw of 6100, and as a result of ¹³ C-NMR analysis, the compound (11-1), the compound (11-2), the repeating unit represented by the compound (11-3), and the content of each repeating unit It was a copolymer having a ratio of 48.2: 39.0: 12.8 (mol%). The extinction coefficient at 300 nm was 0.11 (L / g · cm). This polymer is referred to as “polymer (A-7)”.

化合物（１２−１）４５．０４ｇ（４７モル％）、化合物（１２−２）１４．２５ｇ（１５モル％）、化合物（１２−３）４０．７０ｇ（３８モル％）を２−ブタノン１８７ｇに溶解した単量体溶液（１）、ジメチル２，２'−アゾビス（２−メチルプロピオネート）４．２２ｇを２−ブタノン８０ｇに溶解した溶液（２）を準備し、さらに前述したＣＴＡ−３で表される化合物を３．５２ｇ、２−ブタノンを１９ｇ投入した１０００ｍｌの三口フラスコに前に準備した単量体溶液（１）２８．７７ｇ、溶液（２）５．２９ｇを投入し、その後減圧置換法にて窒素パージする。窒素パージの後、反応釜を攪拌しながら８０℃に加熱し、１５分後、単量体溶液（１）２５８．９８ｇ、溶液（２）３０．８０ｇを送液ポンプを用いて３時間かけて滴下した。滴下終了後さらに４時間攪拌した。重合終了後、重合溶液は放冷することにより３０℃以下に冷却した。その後ジメチル２，２'−アゾビス（２−メチルプロピオネート）９．９３ｇを重合溶液に加え、８０℃に加熱し３時間攪拌した。反応終了後、溶液は放冷し３０℃以下に冷却し、４０００ｇのイソプロピルアルコールへ投入し、析出した白色粉末をろ別する。ろ別された白色粉末を２度２０００ｇのイソプロピルアルコールにてスラリー上で洗浄した後、ろ別し、６０℃にて１７時間乾燥し、白色粉末の重合体を得た（６５ｇ、収率６５％）。この重合体はＭｗが５９００であり、¹³Ｃ-ＮＭＲ分析の結果、化合物（１２−１）、化合物（１２−２）、化合物（１２−３）で表される繰り返し単位、各繰り返し単位の含有率が４８．１：１４．３：３７．６（モル％）の共重合体であった。また、３００ｎｍにおける吸光係数は０．１２（Ｌ／ｇ・ｃｍ）であった。この重合体を重合体（Ａ−８）とする。 Synthesis example 8

Compound (12-1) 45.04 g (47 mol%), compound (12-2) 14.25 g (15 mol%), compound (12-3) 40.70 g (38 mol%) into 2-butanone 187 g A dissolved monomer solution (1) and a solution (2) in which 4.22 g of dimethyl 2,2′-azobis (2-methylpropionate) was dissolved in 80 g of 2-butanone were prepared, and CTA-3 described above was further prepared. The monomer solution (1) (28.77 g) and the solution (2) (5.29 g) prepared previously were charged into a 1000 ml three-necked flask charged with 3.52 g of the compound represented by the formula (2) and 19 g of 2-butanone, and then reduced in pressure. Purge nitrogen with the replacement method. After purging with nitrogen, the reaction kettle was heated to 80 ° C. with stirring. After 15 minutes, 258.98 g of monomer solution (1) and 30.80 g of solution (2) were added over 3 hours using a feed pump. It was dripped. After completion of the dropwise addition, the mixture was further stirred for 4 hours. After completion of the polymerization, the polymerization solution was allowed to cool and then cooled to 30 ° C. or lower. Thereafter, 9.93 g of dimethyl 2,2′-azobis (2-methylpropionate) was added to the polymerization solution, heated to 80 ° C. and stirred for 3 hours. After completion of the reaction, the solution is allowed to cool, cooled to 30 ° C. or lower, poured into 4000 g of isopropyl alcohol, and the precipitated white powder is filtered off. The filtered white powder was washed twice with 2000 g of isopropyl alcohol on the slurry, filtered, and dried at 60 ° C. for 17 hours to obtain a white powder polymer (65 g, yield 65%). ). This polymer has Mw of 5900, and as a result of ¹³ C-NMR analysis, the compound (12-1), the compound (12-2), the repeating unit represented by the compound (12-3), the content of each repeating unit It was a copolymer having a ratio of 48.1: 14.3: 37.6 (mol%). The extinction coefficient at 300 nm was 0.12 (L / g · cm). This polymer is referred to as “polymer (A-8)”.

化合物（１３−１）５８．０５ｇ（５５モル％）、化合物（１３−２）１３．９８ｇ（１５モル％）、化合物（１３−３）２７．９６ｇ（３５モル％）を２−ブタノン１８７ｇに溶解した単量体溶液（１）、ジメチル２，２'−アゾビス（２−メチルプロピオネート）４．４３ｇを２−ブタノン８４ｇに溶解した溶液（２）を準備し、さらに前述したＣＴＡ−３で表される化合物を３．６９ｇ、２−ブタノンを２０ｇ投入した１０００ｍｌの三口フラスコに前に準備した単量体溶液（１）２８．７７ｇ、溶液（２）５．５５ｇを投入し、その後減圧置換法にて窒素パージする。窒素パージの後、反応釜を攪拌しながら８０℃に加熱し、１５分後、単量体溶液（１）２５８．９８ｇ、溶液（２）３２．３４ｇを送液ポンプを用いて３時間かけて滴下した。滴下終了後さらに４時間攪拌した。重合終了後、溶液は放冷し３０℃以下に冷却し、４０００ｇのイソプロピルアルコールへ投入し、析出した白色粉末をろ別する。ろ別された白色粉末を２度２０００ｇのイソプロピルアルコールにてスラリー上で洗浄した後、ろ別し、６０℃にて１７時間乾燥し、白色粉末の重合体を得た（６９ｇ、収率６９％）。この重合体はＭｗが７３００であり、¹³Ｃ-ＮＭＲ分析の結果、化合物（１３−１）、化合物（１３−２）、化合物（１３−３）で表される繰り返し単位、各繰り返し単位の含有率が５６．５：８．５：３５．０（モル％）の共重合体であった。また、３００ｎｍにおける吸光係数は１．３５（Ｌ／ｇ・ｃｍ）であった。この重合体を重合体（Ａ−９）とする。 Synthesis Example 9

Compound (13-1) 58.05 g (55 mol%), compound (13-2) 13.98 g (15 mol%), compound (13-3) 27.96 g (35 mol%) into 2-butanone 187 g A dissolved monomer solution (1) and a solution (2) in which 4.43 g of dimethyl 2,2′-azobis (2-methylpropionate) was dissolved in 84 g of 2-butanone were prepared, and the CTA-3 described above was further prepared. The monomer solution (1) (28.77 g) and the solution (2) (5.55 g) prepared above were added to a 1000 ml three-necked flask containing 3.69 g of the compound represented by (2) and 20 g of 2-butanone. Purge nitrogen with the replacement method. After purging with nitrogen, the reaction kettle was heated to 80 ° C. with stirring. After 15 minutes, 258.98 g of monomer solution (1) and 32.34 g of solution (2) were added over 3 hours using a feed pump. It was dripped. After completion of the dropwise addition, the mixture was further stirred for 4 hours. After completion of the polymerization, the solution is allowed to cool, cooled to 30 ° C. or lower, poured into 4000 g of isopropyl alcohol, and the precipitated white powder is filtered off. The filtered white powder was washed twice with 2000 g of isopropyl alcohol on the slurry, filtered, and dried at 60 ° C. for 17 hours to obtain a white powder polymer (69 g, yield 69%). ). This polymer has Mw of 7300, and as a result of ¹³ C-NMR analysis, the compound (13-1), the compound (13-2), the repeating unit represented by the compound (13-3), and the content of each repeating unit It was a copolymer having a ratio of 56.5: 8.5: 35.0 (mol%). The extinction coefficient at 300 nm was 1.35 (L / g · cm). This polymer is referred to as “polymer (A-9)”.

Synthesis Example 10
Compound (8-1) 50.16 g (50 mol%), compound (8-2) 39.14 g (37 mol%), compound (8-3) 10.69 g (13 mol%) to 2-butanone 187 g A dissolved monomer solution (1) and a solution (2) in which 4.22 g of dimethyl 2,2′-azobis (2-methylpropionate) was dissolved in 80 g of 2-butanone were prepared. The monomer solution (1) (28.77 g) and the solution (2) (5.29 g) prepared above were charged into a 1000 ml three-necked flask charged with 4.30 g of the compound represented by 1 and 19 g of 2-butanone. Purge with nitrogen by vacuum replacement. After purging with nitrogen, the reaction kettle was heated to 80 ° C. with stirring. After 15 minutes, 258.98 g of monomer solution (1) and 30.80 g of solution (2) were added over 3 hours using a feed pump. It was dripped. After completion of the dropwise addition, the mixture was further stirred for 4 hours. After completion of the polymerization, the polymerization solution was allowed to cool and then cooled to 30 ° C. or lower. Thereafter, 10.39 g of dimethyl 2,2′-azobis (2-methylpropionate) was added to the polymerization solution, heated to 80 ° C. and stirred for 3 hours. After completion of the reaction, the solution is allowed to cool, cooled to 30 ° C. or lower, poured into 4000 g of isopropyl alcohol, and the precipitated white powder is filtered off. The filtered white powder was washed twice with 2000 g of isopropyl alcohol on the slurry, filtered, and dried at 60 ° C. for 17 hours to obtain a white powder polymer (73 g, yield 73%). ). This polymer has Mw of 6200, and as a result of ¹³ C-NMR analysis, the compound (8-1), the compound (8-2), the repeating unit represented by the compound (8-3), and the content of each repeating unit The ratio of the copolymer was 52.1: 34.0: 13.9 (mol%). The extinction coefficient at 300 nm was 0.08 (L / g · cm). This polymer is referred to as “polymer (A-10)”.

Synthesis Example 11
Compound (8-1) 50.16 g (50 mol%), compound (8-2) 39.14 g (37 mol%), compound (8-3) 10.69 g (13 mol%) to 2-butanone 187 g A dissolved monomer solution (1) and a solution (2) in which 4.22 g of dimethyl 2,2′-azobis (2-methylpropionate) was dissolved in 80 g of 2-butanone were prepared. The monomer solution (1) (28.77 g) and the solution (2) (5.29 g) prepared previously were charged into a 1000 ml three-necked flask charged with 4.53 g of the compound represented by the formula (2) and 19 g of 2-butanone, and then reduced in pressure. Purge nitrogen with the replacement method. After purging with nitrogen, the reaction kettle was heated to 80 ° C. with stirring. After 15 minutes, 258.98 g of monomer solution (1) and 30.80 g of solution (2) were added over 3 hours using a feed pump. It was dripped. After completion of the dropwise addition, the mixture was further stirred for 4 hours. After completion of the polymerization, the polymerization solution was allowed to cool and then cooled to 30 ° C. or lower. Thereafter, 10.39 g of dimethyl 2,2′-azobis (2-methylpropionate) was added to the polymerization solution, heated to 80 ° C. and stirred for 3 hours. After completion of the reaction, the solution is allowed to cool, cooled to 30 ° C. or lower, poured into 4000 g of isopropyl alcohol, and the precipitated white powder is filtered off. The filtered white powder was washed twice with 2000 g of isopropyl alcohol on the slurry, filtered, and dried at 60 ° C. for 17 hours to obtain a white powder polymer (73 g, yield 73%). ). This polymer has Mw of 6100, and as a result of ¹³ C-NMR analysis, the compound (8-1), the compound (8-2), the repeating unit represented by the compound (8-3), the content of each repeating unit It was a copolymer having a ratio of 55.1: 30.1: 14.8 (mol%). The extinction coefficient at 300 nm was 0.10 (L / g · cm). This polymer is referred to as “polymer (A-11)”.

Synthesis Example 12
Compound (8-1) 50.16 g (50 mol%), compound (8-2) 39.14 g (37 mol%), compound (8-3) 10.69 g (13 mol%) to 2-butanone 187 g A dissolved monomer solution (1) and a solution (2) in which 4.22 g of dimethyl 2,2′-azobis (2-methylpropionate) was dissolved in 80 g of 2-butanone were prepared, and CTA-4 described above was further prepared. The monomer solution (1) (28.77 g) and the solution (2) (5.29 g) prepared above were charged into a 1000 ml three-necked flask charged with 4.07 g of the compound represented by (19) and 19 g of 2-butanone, and then the pressure was reduced. Purge nitrogen with the replacement method. After purging with nitrogen, the reaction kettle was heated to 80 ° C. with stirring. After 15 minutes, 258.98 g of monomer solution (1) and 30.80 g of solution (2) were added over 3 hours using a feed pump. It was dripped. After completion of the dropwise addition, the mixture was further stirred for 4 hours. After completion of the polymerization, the polymerization solution was allowed to cool and then cooled to 30 ° C. or lower. Thereafter, 10.39 g of dimethyl 2,2′-azobis (2-methylpropionate) was added to the polymerization solution, heated to 80 ° C. and stirred for 3 hours. After completion of the reaction, the solution is allowed to cool, cooled to 30 ° C. or lower, poured into 4000 g of isopropyl alcohol, and the precipitated white powder is filtered off. The filtered white powder was washed twice with 2000 g of isopropyl alcohol on the slurry, filtered, and dried at 60 ° C. for 17 hours to obtain a white powder polymer (72 g, yield 72%). ). This polymer has Mw of 6200, and as a result of ¹³ C-NMR analysis, the compound (8-1), the compound (8-2), the repeating unit represented by the compound (8-3), and the content of each repeating unit The ratio was 52.5: 30.9: 16.6 (mol%). The extinction coefficient at 300 nm was 0.08 (L / g · cm). This polymer is referred to as “polymer (A-12)”.

Synthesis Example 13
Compound (8-1) 50.16 g (50 mol%), compound (8-2) 39.14 g (37 mol%), compound (8-3) 10.69 g (13 mol%) to 2-butanone 187 g A dissolved monomer solution (1) and a solution (2) in which 8.44 g of dimethyl 2,2′-azobis (2-methylpropionate) were dissolved in 80 g of 2-butanone were prepared, and the CTA-3 described above was further prepared. The monomer solution (1) (28.77 g) and the solution (2) (10.58 g) prepared above were added to a 1000 ml three-neck flask charged with 7.04 g of the compound represented by Purge nitrogen with the replacement method. After purging with nitrogen, the reaction kettle was heated to 80 ° C. with stirring. After 15 minutes, 258.98 g of monomer solution (1) and 61.60 g of solution (2) were added over 3 hours using a liquid feed pump. It was dripped. After completion of the dropwise addition, the mixture was further stirred for 4 hours. After completion of the polymerization, the polymerization solution was allowed to cool and then cooled to 30 ° C. or lower. Thereafter, 10.39 g of dimethyl 2,2′-azobis (2-methylpropionate) was added to the polymerization solution, heated to 80 ° C. and stirred for 3 hours. After completion of the reaction, the solution is allowed to cool, cooled to 30 ° C. or lower, poured into 4000 g of isopropyl alcohol, and the precipitated white powder is filtered off. The filtered white powder was washed twice with 2000 g of isopropyl alcohol on the slurry, filtered, and dried at 60 ° C. for 17 hours to obtain a white powder polymer (73 g, yield 73%). ). This polymer has Mw of 4100, and as a result of ¹³ C-NMR analysis, the compound (8-1), the compound (8-2), the repeating unit represented by the compound (8-3), the content of each repeating unit The ratio was 52.1: 30.1: 17.8 (mol%). The extinction coefficient at 300 nm was 0.14 (L / g · cm). This polymer is referred to as “polymer (A-13)”.

Synthesis Example 14
Compound (8-1) 50.16 g (50 mol%), compound (8-2) 39.14 g (37 mol%), compound (8-3) 10.69 g (13 mol%) to 2-butanone 187 g A dissolved monomer solution (1) and a solution (2) in which 4.22 g of dimethyl 2,2′-azobis (2-methylpropionate) were dissolved in 80 g of 2-butanone were prepared, and further pyrazole-1-di The monomer solution (1) (28.77 g) and the solution (2) (5.29 g) prepared previously were charged into a 1000 ml three-necked flask charged with 3.52 g of thiocarboxylic acid cyanodimethylmethyl ester and 19 g of 2-butanone. Purge with nitrogen by vacuum replacement. After purging with nitrogen, the reaction kettle was heated to 80 ° C. with stirring. After 15 minutes, 258.98 g of monomer solution (1) and 30.80 g of solution (2) were added over 3 hours using a feed pump. It was dripped. After completion of the dropwise addition, the mixture was further stirred for 4 hours. After completion of the polymerization, the polymerization solution is allowed to cool to cool to 30 ° C. or less, charged into 4000 g of isopropyl alcohol, and the precipitated white powder is filtered off. The filtered white powder was washed twice with 2000 g of isopropyl alcohol on the slurry, filtered, and dried at 60 ° C. for 17 hours to obtain a white powder polymer (82 g, yield 82%). ). This polymer has Mw of 6200, and as a result of ¹³ C-NMR analysis, the compound (8-1), the compound (8-2), the repeating unit represented by the compound (8-3), and the content of each repeating unit It was a copolymer having a ratio of 51.1: 32.1: 16.8 (mol%). The extinction coefficient at 300 nm was 1.25 (L / g · cm). This polymer is referred to as “polymer (A-14)”.

The radiation transmittance of the obtained polymers (A-1) to (A-14) was measured by the following method. The results are shown in Table 1.
Measuring method of radiation transmittance:
A 10% by weight propylene glycol methyl ether acetate resin solution of the polymers (A-1) to (A-14) was applied onto quartz glass by spin coating, and was heated for 90 seconds on a hot plate maintained at 110 ° C. With respect to the resist film having a film thickness of 265 nm formed by performing the intermediate PB, the radiation transmittance was calculated from the absorbance at a wavelength of 193 nm and used as a measure of transparency in the far ultraviolet region.

Examples 1 to 16
Each polymer obtained in Synthesis Example 1 to Synthesis Example 14, the acid generator shown below, and other components were blended in the proportions shown in Table 3 to obtain each radiation-sensitive resin composition solution. The obtained radiation-sensitive resin composition solution was exposed under the conditions shown in Table 4 and subjected to various evaluations. The evaluation results are shown in Table 4. Here, the part is based on weight unless otherwise specified.
Acid generator (B)
(B-1): Triphenylsulfonium nonafluoro-n-butanesulfonate (B-2): 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium nonafluoro-n-butanesulfonate diffusion control Agent (C)
(C-1): Nt-butoxycarbonyl-4-hydroxy-piperidine alicyclic additive (D)
(D-1): 2-bicyclo [2.2.1] hept-2-ylmethyl-1,1,1,3,3,3-hexafluoropropan-2-ol solvent (E)
(E-1): Propylene glycol methyl ether acetate (E-2): Cyclohexanone

Evaluation method (1) Sensitivity:
When performing exposure with an ArF light source, a silicon wafer (AR) having an ARC29 (made by Brewer Science) film with a film thickness of 77 nm formed on the wafer surface
C29), each composition solution was applied onto a substrate by spin coating, and PB was performed on a hot plate under the conditions shown in Table 3 to form a resist film having a thickness of 200 nm on a Nikon ArF excimer. It exposed through the mask pattern using the laser exposure apparatus (numerical aperture 0.75). Thereafter, PEB is performed under the conditions shown in Table 2, and then developed with a 2.38 wt% tetramethylammonium hydroxide aqueous solution at 25 ° C. for 60 seconds, washed with water, and dried to form a positive resist pattern. did. At this time, the exposure amount for forming a line-and-space pattern (1L1S) having a line width of 85 nm in a one-to-one line width was defined as the optimum exposure amount, and this optimum exposure amount was defined as the sensitivity.
(2) Resolution:
The dimension of the smallest line and space pattern that can be resolved at the optimum exposure dose was taken as the resolution.
(3) Pattern profile:
The bottom side dimension L1 and the top and bottom side dimension L2 of the rectangular cross section of the line and space pattern (1L1S) having a line width of 160 nm are measured with a scanning electron microscope, and 0.85 ≦ L2 / L1 ≦ 1 is satisfied, and The case where the pattern profile did not have a tail was determined to be “good”.
(4) Line edge roughness (LER):
When observing the 110 nm 1L / 1S pattern resolved at the optimum exposure dose, the line width is observed at an arbitrary point when observing from the top of the pattern with Hitachi SEM: S9220, and the measurement variation is evaluated with 3 sigma. did.

  As shown in Table 4, a radiation-sensitive resin composition excellent in not only sensitivity, resolution, and pattern file, which are basic resist performances, but also line edge roughness (LER) characteristics can be obtained.

  Since the radiation-sensitive resin composition of the present invention is highly transparent to radiation, has high resolution, and has excellent basic physical properties as a resist including a pattern profile, pattern line edge roughness (LER), and the like. Further, it is extremely useful as a chemically amplified resist for manufacturing semiconductor devices, which is expected to be further miniaturized.

Claims (4)

A radiation-sensitive resin composition comprising an acid-dissociable group-containing polymer containing at least two types of repeating units having different acid-dissociable groups, and a radiation-sensitive acid generator,
A radiation-sensitive resin composition, wherein the acid-dissociable group-containing polymer is polymerized by living radical polymerization using a chain transfer agent represented by the formula (X-1).

(In formula (X-1), R ^a represents a substituted or unsubstituted hydrocarbon group, and Z represents a group containing a substituted or unsubstituted heteroatom.) The radiation-sensitive resin composition according to claim 1, wherein Z is a substituent represented by the formula (X-2).

(In the formula (X-2), R ^b , R ^c and R ^d are each independently a hydrogen atom, a substituted or unsubstituted hydrocarbon group, a hydrocarbon group containing a substituted or unsubstituted heteroatom, or these A group formed by a combination of groups, or a ring containing 3 to 50 non-hydrogen atoms formed by bonding any two of R ^b , R ^c and R ^d to each other. The radiation-sensitive resin composition according to claim 1 or 2, wherein the repeating units having different acid dissociable groups are represented by the formula (1), the formula (2), or the formula (3).

(In the formula (1), the formula (2) or the formula (3), R represents a hydrogen atom or a methyl group, and in the formula (1), A represents a substituted or unsubstituted cyclopentane, cyclohexane, bicyclo [ 2.2.1] Heptane, tricyclo [5.2.1.0 ^2,6 ] decane, or residue obtained by removing carbon atoms forming a ring from tricyclo [3.3.1.1 ^3,7 ] decane B represents a substituted or unsubstituted residue obtained by removing a hydrogen atom from bicyclo [2.2.1] heptane or tricyclo [3.3.1.1 ^3,7 ] decane, and R ¹ Are each independently a linear or branched alkyl group having 1 to 4 carbon atoms.) The radiation sensitive group according to claim 1, 2 or 3, wherein the acid-dissociable group-containing polymer has residues derived from the chain transfer agent at all or a part of molecular chain terminals. Resin composition.