JP2006045136A - Pyrazole derivative, chain transfer agent, acid-dissociating group-containing polymer, and radiation-sensitive resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radiation-sensitive resin composition capable of being suitably used as a chemical amplification-type resist useful for fine processing, to provide an acid-dissociating group-containing polymer, and to provide a pyrazole derivative capable of being suitably used as a chain transfer agent for producing the copolymer. <P>SOLUTION: This pyrazole derivative is expressed by formula (1) (R, R<SP>2</SP>and R<SP>3</SP>are each an alkyl, an alicyclic, an alkenyl, an aryl or an heteroaryl, wherein R<SP>2</SP>and R<SP>3</SP>may combine with each other to form one or more rings; R<SP>1</SP>is H, a substituted or unsubstituted alkyl or a substituted or unsubstituted alicyclic; and n is an integer of 0 to 3). The acid-dissociating group-containing polymer is obtained by polymerization for which the derivative is used as the chain transfer agent. The radiation-sensitive resin composition contains the derivative. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a pyrazole derivative, a chain transfer agent, an acid-dissociable group-containing polymer, and a radiation-sensitive resin composition, and in particular, far ultraviolet rays such as KrF excimer laser or ArF excimer laser, X-rays such as synchrotron radiation, electron beams, etc. A radiation-sensitive resin composition that can be suitably used as a chemically amplified resist useful for microfabrication using various types of radiation such as charged particle beams, and an acid-dissociable group-containing polymer that can be used in the composition, and The present invention relates to a chain transfer agent that can be suitably used for the production of such a copolymer and a pyrazole derivative that can be used as a chain transfer agent.

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, there is known a photoresist polymer compound in which a polymer having a specific structure including a monomer unit having a norbornane ring derivative is used as a resin component (see Patent Documents 1 and 2). .

  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 (see Patent Documents 3 to 6, Non-Patent Document 1).

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. At the same time, as the miniaturization progresses, the demand for reducing the line edge roughness of the pattern has increased. Further, with the miniaturization, it is also required to reduce a margin for process conditions, for example, density / isobias dependency of a pattern. With the advancement of miniaturization in the semiconductor industry, there is an urgent need to develop a radiation-sensitive resin composition that satisfies such conditions as excellent resolution, low pattern line edge roughness, and low pattern density dependency. Yes.
JP 2002-201232 A JP 2002-145955 A International Publication No. WO 98/01478 International Publication No. WO99 / 05099 US Pat. No. 6,395,850 US Patent Publication 6,380,335 Macromolecules 1999, 32, 6777-6980.

  The present invention is highly transparent to radiation, and has excellent basic physical properties as a resist, such as sensitivity, resolution, dry etching resistance, pattern shape, etc., high resolution performance, low pattern line edge roughness, and pattern density. Radiation-sensitive resin composition having low dependency, acid-dissociable group-containing polymer that can be used in this radiation-sensitive resin composition, and chain transfer agent that can be suitably used for the production of such a copolymer And a pyrazole derivative that can be used as a chain transfer agent.

  The present invention provides a pyrazole derivative represented by the formula (1) and a chain transfer agent for living radical polymerization comprising the pyrazole derivative.

〔式（１）において、Ｒは相互に独立に、炭素数１〜２０の置換若しくは非置換のアルキル基、炭素数３〜２０の置換若しくは非置換の脂環族基、炭素数２〜２０の置換若しくは非置換のアルケニル基、置換若しくは非置換のアリール基、置換若しくは非置換のヘテロアリール基を示し、ｎは０〜３の整数である。Ｒ¹は、水素原子若しくは炭素数１〜２０の置換若しくは非置換のアルキル基、炭素数３〜２０の置換若しくは非置換の脂環族基を示す。Ｒ²、Ｒ³は炭素数１〜２０の置換若しくは非置換のアルキル基、炭素数３〜２０の置換若しくは非置換の脂環族基、炭素数２〜２０の置換または非置換のアルケニル基、置換若しくは非置換のアリール基、置換若しくは非置換のヘテロアリール基を示す。また、Ｒ²とＲ³はそれぞれ互いに結合して１つ以上の環を形成してもよい。〕

[In Formula (1), R is mutually independently a C1-C20 substituted or unsubstituted alkyl group, a C3-C20 substituted or unsubstituted alicyclic group, C2-C20. A substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group is shown, and n is an integer of 0 to 3. R ¹ represents a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted alicyclic group having 3 to 20 carbon atoms. R ² and R ³ are substituted or unsubstituted alkyl groups having 1 to 20 carbon atoms, substituted or unsubstituted alicyclic groups having 3 to 20 carbon atoms, substituted or unsubstituted alkenyl groups having 2 to 20 carbon atoms, A substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group is shown. R ² and R ³ may be bonded to each other to form one or more rings. ]

  The present invention also provides an acid-dissociable group-containing polymer containing the repeating unit represented by the formula (2) and a repeating unit having an acid-dissociable group, wherein the polymer uses the chain transfer agent. The present invention provides an acid-dissociable group-containing polymer that is polymerized by radical polymerization, and a radiation-sensitive resin composition containing the acid-dissociable group-containing polymer and a radiation-sensitive acid generator.

〔式（２）において、Ｒ⁴は水素原子、メチル基、またはトリフルオロメチル基を表し、Ｘは炭素数４〜２０の炭素原子および水素原子のみからなる多環型脂環式炭化水素基を表す。〕

[In the formula (2), R ⁴ represents a hydrogen atom, a methyl group, or a trifluoromethyl group, and X represents a polycyclic alicyclic hydrocarbon group having only 4 to 20 carbon atoms and hydrogen atoms. To express. ]

  In this invention, it is preferable that an acid dissociable group containing polymer further contains the repeating unit represented by Formula (3).

〔式（３）において、Ｒ⁵は水素原子、メチル基、またはトリフルオロメチル基を表し、Ｒ⁶は相互に独立に、水素原子、炭素数１〜４の直鎖状あるいは分岐状のアルキル基、炭素数１〜４の直鎖状あるいは分岐状のアルコキシ基、または、炭素数１〜４の直鎖状あるいは分岐状のフッ素化アルキル基を表す。ｎは０〜３の整数である。〕

In [Equation (3), R ⁵ is a hydrogen atom, a methyl group or a trifluoromethyl group,, R ⁶ independently of one another, a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms Represents a linear or branched alkoxy group having 1 to 4 carbon atoms, or a linear or branched fluorinated alkyl group having 1 to 4 carbon atoms. n is an integer of 0-3. ]

  Furthermore, it is preferable that the repeating unit having an acid dissociable group is at least one repeating unit selected from the repeating unit represented by the formula (4) and the repeating unit represented by the formula (5).

〔式（４）および式（５）において、Ｒ⁷およびＲ¹¹は水素原子、メチル基、またはトリフルオロメチル基をそれぞれ表し、Ｒ⁸およびＲ⁹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、Ｒ¹⁰は炭素数４〜２０の脂環式炭化水素基をそれぞれ表し、Ｒ¹²は炭素数１〜４の直鎖状または分岐状のアルキル基を、Ｒ¹³およびＲ¹⁴は相互に独立に水素原子、または炭素数１〜４の直鎖状または分岐状のアルキル基をそれぞれ表し、ｎは３〜７の整数を表す。〕

[In the formulas (4) and (5), R ⁷ and R ¹¹ each represent a hydrogen atom, a methyl group, or a trifluoromethyl group, and R ⁸ and R ⁹ are each independently a straight chain having 1 to 4 carbon atoms. A chain or branched alkyl group, R ¹⁰ represents an alicyclic hydrocarbon group having 4 to 20 carbon atoms, R ¹² represents a linear or branched alkyl group having 1 to 4 carbon atoms, R ¹³ and R ¹⁴ each independently represent a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms, and n represents an integer of 3 to 7. ]

  It is also preferred that the acid-dissociable group-containing polymer has a residue derived from the chain transfer agent at all or part of the molecular chain terminal.

  The radiation-sensitive composition of the present invention is a chemically amplified resist that is sensitive to actinic radiation, particularly far ultraviolet rays typified by ArF excimer laser (wavelength 193 nm), and has high transparency to radiation, dry etching resistance, and pattern shape. Not only has the basic performance as a good resist, but first, it is possible to improve the resolution performance, and second, it can reduce the line edge roughness of the pattern after development. . The acid-dissociable group-containing polymer of the present invention can be suitably used for such a radiation-sensitive resin composition. The chain transfer agent of the present invention can be suitably used when such an acid dissociable group-containing polymer is produced by living radical polymerization. Furthermore, the pyrazole derivative of the present invention can be suitably used as such a chain transfer agent for living radical polymerization.

  Hereinafter, embodiments of the present invention will be specifically described, but the present invention is not limited to the following embodiments, and is based on ordinary knowledge of a person skilled in the art without departing from the spirit of the present invention. It should be understood that changes, improvements, etc. may be added as appropriate.

  The present invention provides an acid-dissociable group-containing polymer having a specific repeating unit structure using a special chain transfer agent. By using this polymer, the basic physical properties as a resist are excellent, and the resolution performance is high. This is based on the knowledge that a radiation-sensitive resin composition having a high pattern and a small line edge roughness can be obtained.

  This chain transfer agent consists of a novel pyrazole derivative represented by the formula (1).

〔式（１）において、Ｒは相互に独立に、炭素数１〜２０の置換若しくは非置換のアルキル基、炭素数３〜２０の置換若しくは非置換の脂環族基、炭素数２〜２０の置換若しくは非置換のアルケニル基、置換若しくは非置換のアリール基、置換若しくは非置換のヘテロアリール基を示し、ｎは０〜３の整数である。Ｒ¹は、水素原子若しくは炭素数１〜２０の置換若しくは非置換のアルキル基、炭素数３〜２０の置換若しくは非置換の脂環族基を示す。Ｒ²、Ｒ³は炭素数１〜２０の置換若しくは非置換のアルキル基、炭素数３〜２０の置換若しくは非置換の脂環族基、炭素数２〜２０の置換または非置換のアルケニル基、置換若しくは非置換のアリール基、置換若しくは非置換のヘテロアリール基を示す。また、Ｒ²とＲ³はそれぞれ互いに結合して１つ以上の環を形成してもよい。〕

[In Formula (1), R is mutually independently a C1-C20 substituted or unsubstituted alkyl group, a C3-C20 substituted or unsubstituted alicyclic group, C2-C20. A substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group is shown, and n is an integer of 0 to 3. R ¹ represents a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted alicyclic group having 3 to 20 carbon atoms. R ² and R ³ are substituted or unsubstituted alkyl groups having 1 to 20 carbon atoms, substituted or unsubstituted alicyclic groups having 3 to 20 carbon atoms, substituted or unsubstituted alkenyl groups having 2 to 20 carbon atoms, A substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group is shown. R ² and R ³ may be bonded to each other to form one or more rings. ]

By performing radical polymerization using this pyrazole derivative as a chain transfer agent, this polymerization exhibits a so-called living property in which the molecular weight increases with the polymerization time, and the molecular weight can be easily controlled. In formula (1), a pyrazole derivative in which R ³ is OR ′ (R ′ represents a hydrocarbon group), that is, a pyrazole derivative having an ester group is disclosed in Patent Document 6, for example. For example, when this derivative is used for radical polymerization of an acrylate monomer, the relationship between the polymerization time and the molecular weight is as shown in the conceptual diagram of FIG. High living property. However, for example, when used for radical polymerization of a methacrylic acid ester monomer, the relationship between the polymerization time and the molecular weight is as shown by the line B in FIG. 1, and the living property of the polymerization reaction is lowered.

  On the other hand, when the pyrazole derivative represented by the formula (1) is used, the relationship between the polymerization time and the molecular weight is shown in A of FIG. 1 regardless of whether the monomer is an acrylate ester or a methacrylate ester. It becomes a relationship as shown by a line and can be a polymerization reaction showing high living property. Further, a (meth) acrylic acid ester polymer obtained by radical polymerization using a pyrazole derivative represented by the formula (1) can exhibit good resist characteristics.

  The chain transfer agent of the present invention may be a reversible addition-cleavage chain transfer agent. The reversible addition-cleavage 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).

In the formula (1), specific examples of R, R ² and R ³ include the following groups. That is, examples of the substituted or unsubstituted alkyl group having 1 to 20 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, and an n-heptyl group. Group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group Group, n-octadecyl group, n-nonadecyl group, n-eicosyl group, i-propyl group, i-butyl group, sec-butyl group, t-butyl group, t-dodecyl group and the like.

  Examples of the substituted or unsubstituted alicyclic group having 3 to 20 carbon atoms include cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, and bridged alicyclic hydrocarbon group having 6 to 20 carbon atoms ( Norbornyl group, tricyclodecanyl group, tetracyclododecyl group, adamantyl group, methyladamantyl group, ethyladamantyl group, and butyladamantyl group). Furthermore, examples of the substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms include a vinyl group and a propenyl group.

  Examples of the substituted or unsubstituted aryl group include aryl groups having 6 to 20 carbon atoms such as a phenyl group, toluyl group, benzyl group, methylbenzyl group, xylyl group, mesityl group, naphthyl group, and anthryl group. It is done. On the other hand, examples of the substituted or unsubstituted heteroaryl group include groups containing one or more heteroatoms such as a sulfur atom, an oxygen atom, and a nitrogen atom in the substituted or unsubstituted aryl group. For example, a pyridyl group, Examples include imidazolyl group, morpholinyl group, piperidinyl group, and pyrrolidinyl group.

Also, the R, the hydrocarbon group of R ³ may be substituted by a substituent. Examples of such a substituent include a hydroxyl group, a carboxyl group, and a hydroxyalkyl group having 1 to 4 carbon atoms (hydroxymethyl group, 1-hydroxyethyl group, 2-hydroxyethyl group, 1-hydroxypropyl group, 2-hydroxypropyl group). Group, 3-hydroxypropyl group, 1-hydroxybutyl group, 2-hydroxybutyl group, 3-hydroxybutyl group, 4-hydroxybutyl group, etc.), an alkoxy group having 1 to 4 carbon atoms (methoxy group, ethoxy group, n -Propoxy group, i-propoxy group, n-butoxy group, 2-methylpropoxy group, 1-methylpropoxy group, t-butoxy group, etc.), cyano group, C2-C5 cyanoalkyl group (cyanomethyl group, 2 -Cyanoethyl group, 3-cyanopropyl group, 4-cyanobutyl group, etc.), alkoxycarbonyl group (methoxy) Carbonyl group, ethoxycarbonyl group, t-butoxycarbonyl group, etc.), alkoxycarbonylalkoxy group (methoxycarbonylmethoxy group, ethoxycarbonylmethoxy group, t-butoxycarbonylmethoxy group, etc.), halogen atom (fluorine, chlorine, etc.), and fluoro Examples thereof include alkyl groups (fluoromethyl group, trifluoromethyl group, pentafluoroethyl group, etc.).

Preferred examples of R, R ² and R ³ include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, t-butyl group, n-pentyl group and n-hexyl group. N-heptyl group, n-octyl group, n-dodecyl group, t-dodecyl group, n-hexadecyl group, cyclopentyl group, cyclohexyl group, camphoroyl group, norbornyl group, p-toluyl group, benzyl group, phenyl group, Examples include 1-naphthyl group, 2-naphthyl group, trifluoromethyl group, nonafluorobutyl group, perfluorooctyl group, and methoxycarbonyldifluoromethyl group. The number of R, that is, the value of n is 0 to 3, but is preferably 0 to 2.

Here, “R ² and R ³ may be bonded to each other to form one or more rings.” Means that each atom or group is dissociated from each of R ² and R ³ above. 2 residues such as methylene group, ethylene group, etc., which form a residue and the residues are bonded to each other, or the residue is exemplified by a hetero atom such as a sulfur atom, an oxygen atom and a nitrogen atom. It means that a cyclic structure may be formed by bonding through a divalent organic group exemplified by a valent alkyl group. As apparent from the above description, the cyclic structure may contain a hetero atom such as a sulfur atom, an oxygen atom, and a nitrogen atom.

R ¹ represents a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted alicyclic group having 3 to 20 carbon atoms.

Specific examples of R ¹ include the following groups. That is, examples of the substituted or unsubstituted alkyl group having 1 to 20 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, and an n-heptyl group. Group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group Group, n-octadecyl group, n-nonadecyl group, n-eicosyl group, i-propyl group, i-butyl group, sec-butyl group, t-butyl group, t-dodecyl group and the like.

  Examples of the substituted or unsubstituted alicyclic group having 3 to 20 carbon atoms include cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, and bridged alicyclic hydrocarbon group having 6 to 20 carbon atoms ( Norbornyl group, tricyclodecanyl group, tetracyclododecyl group, adamantyl group, methyladamantyl group, ethyladamantyl group, and butyladamantyl group).

  Specific examples of the pyrazole derivative represented by the formula (1), particularly specific examples that can be suitably used as a chain transfer agent, are represented below as formulas (CTA-1) to (CTA-7).

  The compound represented by the formula (1) is obtained by reacting, for example, a pyrazole derivative (precursor compound) represented by the formula (6) with carbon disulfide in the presence of an inorganic base, and dithioacetic acid intermediate represented by the formula (7). Can be obtained by reacting the dithioacetic acid intermediate with the compound represented by the formula (8).

〔上記反応式において、Ｄは脱離性の１価の基、Ｙは１価の無機カチオンとなる基を示し、Ｒ、Ｒ¹、Ｒ²およびＲ³は上記式（１）におけるＲ、Ｒ¹、Ｒ²およびＲ³と各々同じである。〕

[In the above reaction formula, D represents a detachable monovalent group, Y represents a group that becomes a monovalent inorganic cation, and R, R ¹ , R ^2, and R ³ represent R, R in the above formula (1), respectively. ^1, are each the same as R ² and R ^3. ]

  In the reaction of the precursor compound represented by formula (6) and carbon disulfide, the molar ratio of carbon disulfide to the precursor compound is usually 1 to 100, preferably 3 to 10.

  Examples of the inorganic base used in the reaction include potassium hydroxide, sodium hydroxide, lithium carbonate, sodium carbonate, potassium carbonate, lithium hydrogen carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, and preferably water. Sodium oxide, potassium hydroxide and the like.

  The molar ratio of the inorganic base to the precursor compound is usually 1.0 to 10.0, preferably 2.0 to 4.0.

  The reaction between the precursor compound and carbon disulfide is preferably performed in an organic solvent medium. As the organic solvent, for example, dimethylformamide (DMF), dimethylsulfoxide (DMSO), hexamethylphosphoric triamide (HMPA) is preferable, and DMF and the like are more preferable.

  The reaction temperature of the precursor compound and carbon disulfide is usually −40 to 50 ° C., preferably −20 to 10 ° C., and the reaction time is usually 0.1 to 72 hours, preferably 0.5 to 3 It's time. When the reaction temperature is higher than the boiling point of the organic solvent or water, a pressure vessel such as an autoclave is used.

  Examples of the group that becomes a monovalent inorganic cation of Y in the intermediate represented by the formula (7) include a potassium atom, a sodium atom, and a lithium atom, and a potassium atom and a sodium atom are preferable. .

  Examples of the detachable monovalent group of D in the intermediate represented by the formula (7) include halogen atoms such as fluorine atom, chlorine atom, bromine atom and iodine atom, methanesulfonate group, p- Examples thereof include a toluene sulfonate group, and an iodine atom, a chlorine atom and a bromine atom are preferable.

  Preferable specific examples of the compound represented by the formula (8) include compounds represented by the following formulas (8-1) to (8-8). Since such diketones represented by the formula (8) are relatively easily available, the pyrazole derivatives of the present invention can be synthesized relatively easily.

  Moreover, the molar ratio of the compound represented by the formula (8) to the precursor represented by the formula (7) is usually 1.0 to 20.0, preferably 1.5 to 10.0.

  The reaction temperature between the intermediate and the compound represented by formula (8) is usually −40 to 30 ° C., preferably −20 to 20 ° C., more preferably −5 to 0 ° C., and the reaction time is usually 0.1 to 72 hours, preferably 0.5 to 24 hours.

  Next, a preferred embodiment of the acid dissociable group-containing polymer will be described. The acid dissociable group-containing polymer of the present invention comprises a repeating unit represented by formula (2) (hereinafter also referred to as repeating unit [i-1]) and optionally a repeating unit represented by formula (3) (hereinafter referred to as “repeating unit”). Also referred to as repeating unit [i-2], repeating units [i-1] and [i-2] are collectively referred to as repeating unit [i]) and repeating units having an acid dissociable group (hereinafter referred to as repeating unit [i]). ii]).

〔式（２）において、Ｒ⁴は水素原子、メチル基、またはトリフルオロメチル基を表し、Ｘは炭素数４〜２０の極性基を含まない炭素原子および水素原子のみからなる多環型脂環式炭化水素基を表す。〕

[In the formula (2), R ⁴ represents a hydrogen atom, a methyl group, or a trifluoromethyl group, and X represents a polycyclic alicyclic ring composed of only a carbon atom and a hydrogen atom not containing a polar group having 4 to 20 carbon atoms. Represents a hydrocarbon group. ]

〔式（３）において、Ｒ⁵は水素原子、メチル基、またはトリフルオロメチル基を表し、Ｒ⁶は相互に独立に、水素原子、炭素数１〜４の直鎖状あるいは分岐状のアルキル基、炭素数１〜４の直鎖状あるいは分岐状のアルコキシ基、または、炭素数１〜４の直鎖状あるいは分岐状のフッ素化アルキル基を表す。ｎは０〜３の整数である。〕

In [Equation (3), R ⁵ is a hydrogen atom, a methyl group or a trifluoromethyl group,, R ⁶ independently of one another, a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms Represents a linear or branched alkoxy group having 1 to 4 carbon atoms, or a linear or branched fluorinated alkyl group having 1 to 4 carbon atoms. n is an integer of 0-3. ]

In the repeating unit represented by the formula (2), preferred X includes a polycyclic alicyclic hydrocarbon group composed of only carbon and hydrogen that do not contain a polar group having 7 to 20 carbon atoms. That is, an acid-dissociable group-containing polymer having such a polycyclic alicyclic hydrocarbon group as a part of the side chain is preferable. Examples of such polycyclic alicyclic hydrocarbon groups include bicyclo [2.2.1] heptane (2a) and bicyclo [2.2.2, as shown in the following formulas (2a) to (2e). 2] Octane (2b), tricyclo [5.2.1.0 ^2,6 ] decane (2c), tetracyclo [4.4.0.1 ^2,6 . 1 ^7,10 ] dodecane (2d), tetracyclo [6.2.1.1 ^3,6 . Hydrocarbon groups composed of alicyclic rings derived from cycloalkanes such as [0 ^2,7 ] decane (2e).

  These cycloalkane-derived alicyclic rings may have a substituent. Preferable substituents include, for example, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, t-butyl group and the like. 4 linear, branched or cyclic alkyl groups, and the like, and alicyclic rings having one or more of these as substituents are also preferred. For example, these are represented by the specific examples shown in the following formulas (2f) to (2l), but are not limited thereto. These may be used alone or in combination of two or more.

The acid dissociable group-containing polymer of the present invention may also contain a lactone unit-containing repeating unit represented by the formula (3). A preferred lactone skeleton is 5-oxo-4-oxatricyclo [4.2.1.0 ^3,7 ] nonane, and an acid having an alicyclic hydrocarbon group having this lactone skeleton as part of the side chain. A dissociable group-containing polymer is also preferred. The lactone skeleton may be substituted with a linear or branched alkyl group having 1 to 4 carbon atoms, an alkoxy group, or a fluorinated alkyl group. Examples of the linear or branched alkyl group having 1 to 4 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a 2-methylpropyl group, and a 1-methyl group. Examples thereof include a propyl group and a t-butyl group. Examples of the linear or branched alkoxy group having 1 to 4 carbon atoms include a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, and an n-butoxy group. , 2-methylpropoxy group, 1-methylpropoxy group, t-butoxy group and the like. Examples of the linear or branched fluorinated alkyl group having 1 to 4 carbon atoms include groups in which part or all of the hydrogen atoms in the alkyl group have been substituted with fluorine atoms. It is also preferred that the lactone skeleton has one or more or one or more of these as a substituent.

  The repeating unit [ii] is preferably a repeating unit represented by the formula (4) and / or a repeating unit represented by the formula (5). That is, the acid dissociable group-containing polymer of the present invention contains a repeating unit represented by the formula (4), a repeating unit represented by the formula (5), or a repeating unit and a formula represented by the formula (4). It is preferable that both of the repeating units represented by (5) are included.

〔式（４）および式（５）において、Ｒ⁷およびＲ¹¹は水素原子、メチル基、またはトリフルオロメチル基をそれぞれ表し、Ｒ⁸およびＲ⁹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、Ｒ¹⁰は炭素数４〜２０の脂環式炭化水素基をそれぞれ表し、Ｒ¹²は炭素数１〜４の直鎖状または分岐状のアルキル基を、Ｒ¹³およびＲ¹⁴は相互に独立に水素原子、または炭素数１〜４の直鎖状または分岐状のアルキル基をそれぞれ表し、ｎは３〜７の整数を表す。〕

[In the formulas (4) and (5), R ⁷ and R ¹¹ each represent a hydrogen atom, a methyl group, or a trifluoromethyl group, and R ⁸ and R ⁹ are each independently a straight chain having 1 to 4 carbon atoms. A chain or branched alkyl group, R ¹⁰ represents an alicyclic hydrocarbon group having 4 to 20 carbon atoms, R ¹² represents a linear or branched alkyl group having 1 to 4 carbon atoms, R ¹³ and R ¹⁴ each independently represent a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms, and n represents an integer of 3 to 7. ]

R ⁸ and R ⁹ in the formula (4) are, for example, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, t- A butyl group etc. are mentioned. Examples of R ¹⁰ include cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, bicyclo [2.2.1] heptane, bicyclo [2.2.2] octane, and tricyclo [5.2.1.0 ² ]. ^{, 6} ] decane, tetracyclo [4.4.0.1 ^2,6 . 1 ^7,10 ] dodecane, tetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodecane, or hydrocarbon groups derived from these derivatives. Examples of R ⁷ include a hydrogen atom, a methyl group, and a trifluoromethyl group.

As R < ¹² > in Formula (5), a methyl group, an ethyl group, n-propyl group, i-propyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, t-butyl group etc. are mentioned, for example. Is mentioned. R ¹³ and R ¹⁴ are, for example, a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a 2-methylpropyl group, a 1-methylpropyl group, a t-butyl. Groups and the like. Examples of R ¹¹ include a hydrogen atom, a methyl group, and a trifluoromethyl group.

In the formula (5), it is particularly preferable that R ¹² is a methyl group or an ethyl group, R ¹³ and R ¹⁴ are hydrogen atoms, and n is 4 or 5. Examples of particularly preferred repeating unit [ii] are shown in formulas (5-1) to (5-4).

〔式（５−１）〜（５−４）において、Ｒは水素原子、メチル基、またはトリフルオロメチル基をそれぞれ表す。〕

[In Formula (5-1)-(5-4), R represents a hydrogen atom, a methyl group, or a trifluoromethyl group, respectively. ]

  Among the repeating units represented by the formulas (5-1) to (5-4), the repeating units represented by the formula (5-1) and the formula (5-2) are considered in consideration of the combination of the repeating units of the present invention. preferable.

  The acid-dissociable group-containing polymer of the present invention is preferably composed of the above repeating units [i] and [ii]. As monomers for generating the repeating units represented by the repeating units [i] and [ii], the formula (2-m), the formula (3-m), the formula (4-m), and the formula (5- and an acrylic acid derivative ester represented by m).

〔式（２−ｍ）〜（５−ｍ）において、Ｒ⁴〜Ｒ¹⁴、Ｘ、ｎは、各々式（２）〜（５）におけるＲ⁴〜Ｒ¹⁴、Ｘ、ｎと同一である。〕

In [Formula (2-m) ~ (5 -m), R 4 ~R 14, X, n are the same as R ⁴ ~R ^14, X, n in each formula (2) to (5). ]

The acid-dissociable group-containing polymer of the present invention can further copolymerize other monomers. Preferred monomers to be copolymerized include, for example, (meth) acrylic acid 2-methyladamantan-2-yl ester, (meth) acrylic acid 2-ethyladamantan-2-yl ester, (meth) acrylic acid 2-n-pro Biladamantan-2-yl ester, (meth) acrylic acid 2-isopropylpropyladamantan-2-yl ester, (meth) acrylic acid 1- (adamantan-1-yl) -1-methylethyl ester, (meth) acrylic acid 2-methylbicyclo [2.2.1] hept-2-yl ester, (meth) acrylic acid 2-ethylbicyclo [2.2.1] hept-2-yl ester, (meth) acrylic acid 8-methyltri Cyclo [5.2.1.0 ^2,6 ] dec-8-yl ester, 8-ethyltricyclo [5.2.1.0 ^2,6 ] deca (meth) acrylic acid -8-yl ester, (meth) acrylic acid 4-methyltetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodec-4-yl ester, (meth) acrylic acid 4-ethyltetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodec-4-yl ester, (meth) acrylic acid 1- (tetracyclo [6.2.1.1 ^3,6 .0 ^2,7 ] dodec-4-yl) -1-methylethyl ester And (meth) acrylic acid 1- (adamantan-1-yl) -1-methylethyl ester, (meth) acrylic acid 1,1-dicyclohexylethyl ester and other monomers having an acid-dissociable group.

  The acid-dissociable group-containing polymer of the present invention is preferably composed of the above repeating unit [i-1], repeating unit [i-2] and repeating unit [ii], and the blending ratio thereof is the repeating unit [i]. -1] is 1 to 40 mol%, preferably 3 to 20 mol%; repeating unit [i-2] is 15 to 80 mol%, preferably 20 to 60 mol%; repeating unit (ii) is 15 to 80 mol% %, Preferably 20 to 60 mol%. If the content of the repeating unit [i-2] is less than 15 mol%, the developability as a resist tends to be lowered, and if it exceeds 80 mol%, the resolution is deteriorated and the solubility in a resist solvent tends to be lowered. It is in. If the content of the repeating unit [i-1] is less than 1 mol%, the resolution tends to be lowered, and if it exceeds 40 mol%, the resolution tends to deteriorate. If the content of the repeating unit (ii) is less than 15 mol%, the resolution tends to deteriorate, and if it exceeds 80 mol%, the developability tends to decrease. When the repeating unit [i-1], the repeating unit [i-2], the repeating unit [ii], and other repeating units are used, the blending ratio is the sum of the repeating unit [ii] and the other repeating units. Is 20 to 80 mol%, and among them, the blending in which the repeating unit [ii] is 10 mol% or more is preferable.

  The acid-dissociable group-containing polymer of the present invention is polymerized by living radical polymerization using a chain transfer agent represented by the formula (1). In general, a radical polymerization initiator is used at this time. In order to realize a sufficient polymerization rate, it is preferable to add a radical polymerization initiator having a sufficiently high concentration. However, if the ratio of the amount of radical polymerization initiator to the amount of chain transfer agent is too high, a radical-radical coupling reaction will occur and an undesirable non-living radical polymer will be formed, so the resulting polymer will have a molecular weight and molecular weight distribution, etc. In other words, a portion having uncontrolled characteristics in the polymer characteristics is included. The molar ratio between the amount of radical polymerization initiator and the amount of chain transfer agent is preferably (1: 1) to (0.005: 1).

  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. Specific examples include polymerization initiators such as peroxides and azo compounds. Although not particularly limited, more specific radical polymerization initiators include t-butyl hydroperoxide, t-butyl perbenzoate, benzoyl peroxide, 2,2′-azobis (2,4-dimethylvaleronitrile), 2 2,2′-azobisisobutyronitrile (AIBN), 1,1′-azobis (cyclohexanecarbonitrile), dimethyl-2,2′-azobisisobutyrate (MAIB), and the like.

  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 type and amount of monomer 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, radical polymerization initiator and chain transfer agent is generally 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 dimethylsulfoxide. 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 generally 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.

  The acid dissociable group-containing polymer obtained by the above living radical polymerization method has a residue derived from a chain transfer agent at the end of the molecular chain as shown in the following reaction formula (9). In the present invention, a polymer having a thiocarbonylthio derivative group as a residue can be used as the acid-dissociable group-containing polymer.

  Further, the thiocarbonylthio derivative group can be removed for use. The residue derived from the chain transfer agent can be removed using an excess radical polymerization initiator as shown in the following reaction formula (10), for example.

  The processing method will be described below. The terminal treatment is preferably performed in the state of a solution obtained by dissolving the polymer in a solvent. Preferable solvents that can be used include the same solvents as those described in the description of the polymerization operation. The radical polymerization initiator can be used as long as radicals can be generated under the conditions of the end group treatment of the polymer. 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 terminal treatment can be performed on the product after completion of the living radical polymerization reaction, or on the purified product after purification of the once produced polymer. 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 end group treatment reaction of the polymer is generally about 20 to 200 ° C, preferably 40 to 150 ° C, more preferably 50 to 100 ° C. The reaction atmosphere is preferably an inert atmosphere such as nitrogen or argon, or an air atmosphere. The reaction can be carried out under normal pressure or under pressure. The radical polymerization initiator is 1 to 800 mol%, preferably 50 to 400 mol%, more preferably the total amount of residues present in the polymer to be terminal-treated as the amount of radicals generated by the radical polymerization initiator. 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 terminal treatment is generally 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 generally preferably performed with a removal rate of at least 50%, preferably at least 75%, more preferably at least 85%, even more preferably at least 95%. The end-treated polymer is replaced at the end with new radical species, such as the radical initiator fragment used in the end-treatment reaction. The resulting polymer has a new group at the end and can be used depending on the application. A residue derived from a chain transfer agent can also be removed by the method described in International Publication WO02 / 090397.

  In the present invention, an acid-dissociable group-containing polymer having a residue derived from a chain transfer agent at the molecular chain end, an acid-dissociable group-containing polymer having no residue derived from a chain transfer agent at the molecular chain end, a molecule Any acid-dissociable group-containing polymer in which a part of the residue derived from the chain transfer agent remains at the chain end can be used.

  Naturally, the acid-dissociable group-containing polymer of the present invention has few impurities such as halogen and metal, and the residual monomer and oligomer components are not more than predetermined values, for example, 0.1% by weight or less by HPLC analysis. The radiation-sensitive composition that can be used as a resist not only can further improve the sensitivity, resolution, process stability, pattern shape, etc. as a resist, but also has little change over time such as foreign matter in liquid and sensitivity. Is obtained.

  Examples of the method for purifying the acid dissociable group-containing polymer include the following methods. As a method of 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 residual monomer by coagulating the polymer in the poor solvent by dropping the acid-dissociable group-containing polymer solution into the poor solvent There are a reprecipitation method for removing water 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 acid-dissociable group-containing polymer to be purified and cannot be generally exemplified. However, those skilled in the art can adjust the physical properties of the polymer. It can be selected as appropriate.

  The polystyrene-reduced weight average molecular weight (hereinafter abbreviated as “Mw”) of the acid-dissociable group-containing polymer by gel permeation chromatography (GPC) is usually 1,000 to 300,000, preferably 2,000 to 300. 2,000, more preferably 2,000 to 12,000. When the Mw of the acid dissociable group-containing polymer is less than 1,000, the heat resistance as a resist tends to be lowered, and when it exceeds 300,000, the developability as a resist tends to be lowered.

  The ratio (Mw / Mn) of Mw of the acid-dissociable group-containing polymer to polystyrene-reduced number average molecular weight (hereinafter abbreviated as “Mn”) by gel permeation chromatography (GPC) is usually 1-5. , Preferably 1 to 3, particularly preferably 1.6 or less.

  In this invention, an acid dissociable group containing polymer can be used individually or in mixture of 2 or more types. The acid-dissociable group-containing polymer is insoluble in alkali or hardly soluble in alkali, but becomes easily soluble in alkali by the action of an acid. Therefore, it is suitable as an acid-dissociable group-containing resin used for the radiation-sensitive resin composition.

  A radiation-sensitive resin composition is obtained by combining the acid-dissociable group-containing polymer and an acid generator that is a component that generates an acid upon irradiation with radiation. Examples of the acid generator include onium salts such as sulfonium salts and iodonium salts, organic halogen compounds, and sulfone compounds such as disulfones and diazomethane sulfones.

  Specific preferred examples of the acid generator include the following. Triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium nonafluoro-n-butanesulfonate, triphenylsulfonium perfluoro-n-octanesulfonate, triphenylsulfonium 2-bicyclo [2.2.1] hept-2-yl-1, Triphenylsulfonium salt compounds such as 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 -D Bicyclo [2.2.1] hept-5 such as -2,3-dicarboximide, N- (camphorsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide -Ene-2,3-dicarboximide compounds and the like.

  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 100 parts by weight of the acid-dissociable group-containing polymer from the viewpoint of ensuring the sensitivity and developability as a resist. ~ 20 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) Aminophenyl) 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-butoxycarbonylhexamethyl Range amine, N, N′-di-t-butoxycarbonyl-1,7-diaminoheptane, N, N′-di-t-butoxycarbonyl-1,8-diaminooctane, N, N′-di-t- Butoxycarbonyl-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-phenylbenz Imidazole, Nt-butoxycarbonyl-pyrrolidine, Nt-butoxycarbonyl-piperidine, Nt-buto In addition to Nt-butoxycarbonyl group-containing amino compounds such as cycarbonyl-4-hydroxy-piperidine, Nt-butoxycarbonyl-morpholine, formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N- Examples thereof include methylacetamide, N, N-dimethylacetamide, propionamide, benzamide, pyrrolidone, N-methylpyrrolidone and the like.

  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 acid dissociable group-containing polymer. 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, and 1,3-adamantane dicarboxylic acid. Di-t-butyl, 1-adamantane acetate t-butyl, 1-adamantane acetate t-butoxycarbonylmethyl, 1,3-adamantanediacetate di-t-butyl, 2,5-dimethyl-2,5-di (adamantyl) Adamantane derivatives such as carbonyloxy) hexane; deoxycholic acid t-butyl, deoxycholic acid t-butoxycarbonylmethyl, deoxycholic acid 2-ethoxyethyl, deoxycholic acid 2-cyclohexyloxyethyl, deoxycholic acid 3-oxocyclohexyl , Deoxyco Deoxycholic acid esters such as tetrahydropyranyl acid, deoxycholic acid mevalonolactone ester; t-butyl lithocholic acid, t-butoxycarbonylmethyl lithocholic acid, 2-ethoxyethyl lithocholic acid, 2-cyclohexyloxyethyl lithocholic acid, lithocol Lithocholic acid esters such as 3-oxocyclohexyl acid, tetrahydropyranyl lithocholic acid, mevalonolactone ester of lithocholic acid; dimethyl adipate, diethyl adipate, dipropyl adipate, di-n-butyl adipate, di-t-butyl adipate 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 acid dissociable group containing polymers, 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 acid-dissociable group-containing polymer.

  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. 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 acid-dissociable group-containing polymer.

  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 for 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 mono Chill 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, pyruvate Examples include ethyl, N-methylpyrrolidone, and γ-butyrolactone.

  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 radiation. 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.

  When forming a resist pattern, it is preferable to perform a heat treatment after exposure (hereinafter referred to as PEB) in order to stably form a high-precision fine pattern. By this PEB, the dissociation reaction of the acid dissociable organic group in the acid dissociable group-containing polymer 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.

  When forming a resist pattern, in order to maximize the potential of the radiation-sensitive resin composition, as disclosed in, for example, Japanese Patent Publication No. 6-12452, an organic system is used. Alternatively, an inorganic antireflection film can be formed, and in order to prevent the influence of basic impurities contained in the environmental atmosphere, for example, as disclosed in JP-A-5-188598 Further, a protective film can be provided on the resist film, 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.

  EXAMPLES Hereinafter, although this invention is demonstrated further in detail based on an Example, this invention is not limited to these Examples.

Using a “JMS-AX505W type mass spectrometer” manufactured by JEOL Ltd., mass spectrometry of the compound (α-1) obtained by the method shown below was performed. The analysis conditions are as follows.
Emitter current: 5 mA (used gas: Xe)
Acceleration voltage: 3.0 kV
10N MULTI: 1.3
Ionization method: Fast atom bombardment method (FAB)
Detection ion: Cation (+)
Measurement mass range: 20-1500 m / z
Scan: 30 sec
Resolution: 1500
Matrix: 3-nitrobenzyl alcohol

Further, using a JEOL Ltd. "JNM-EX270", using chloroform -d (CDCl ₃₎ as a measurement solvent was subjected to ¹ H-NMR analysis of the obtained compound (α-1). The ¹³ C-NMR analysis of the polymers (A-1) to (A-10) was performed using “JNM-EX270” manufactured by JEOL Ltd. and using CDCl ₃ as a measurement solvent. In addition, Mw was monodispersed under the analysis conditions of 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.

  The reaction shown in the following reaction formula (11) was carried out by the following method to synthesize (A) the compound (α-1) which is a charge chain transfer agent.

Synthesis of Compound (α-1) In a reaction flask, 20 g of pyrazole was dissolved in 100 ml of DMSO and purged with nitrogen. Then 25 g of sodium hydroxide was added and stirred until dissolved at 20 ° C. In a nitrogen atmosphere, the mixture was cooled to 0 ° C., 50 ml of carbon disulfide was slowly added dropwise, and the mixture was stirred for 1 hour. Thereafter, 58 g of 3-bromo-3-methyl-2,4-pentanedione was added dropwise at 0 ° C., followed by stirring for 6 hours. After the reaction, water was added to the reaction solution, and the reaction solution was transferred to a separatory funnel, added with dichloromethane, shaken and allowed to stand, and then the aqueous layer was removed. Further, 300 ml of distilled water was added and shaken, allowed to stand, and then the aqueous layer was removed. The remaining dichloromethane solution was dried over anhydrous magnesium sulfate and filtered. Thereafter, dichloromethane was distilled off from the dichloromethane solution after drying using an evaporator, the obtained liquid was dried under reduced pressure, and the residue was recrystallized with hexane to obtain a compound (α-1). (Yield 23.2 g, 30% yield). NMR and Mass data of the compound (α-1) are as follows.

¹ HNMR σ ppm (CD ₃ Cl): 1.86 (3H, s, CH ₃ ), 2.38 (6H, s, CH ₃ × 2), 6.47 to 6.49 (1H, m, CH), 7.79 (1H, s, CH), 8.56 (1H, d, J = 3.0 Hz, CH)
MS (FAB) m / z 256 (M +)

Example 1
Compound (12-1) 53.92 g (50 mol%), compound (12-2) 10.69 g (10 mol%), compound (12-3) 35.38 g (40 mol%) into 2-butanone 187 g A dissolved monomer solution (1) and a solution (2) in which 3.37 g of dimethyl 2,2′-azobis (2-methylpropionate) was dissolved in 64 g of 2-butanone were prepared, and the above-described (α- 1) 28.77 g of the monomer solution (1) prepared above and 4.23 g of the solution (2) were charged into a 1000 ml three-necked flask charged with 2.96 g of the compound represented by 1) and 15 g of 2-butanone. Nitrogen was purged by a vacuum replacement method. After purging with nitrogen, the inside of the three-necked flask was heated to 80 ° C. with stirring. After 15 minutes, 258.98 g of the monomer solution (1) and 24.64 g of the solution (2) were added over 3 hours using a liquid feed pump. And 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, 11.17 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 was allowed to cool, cooled to 30 ° C. or lower, poured into 4000 g of isopropyl alcohol, and the precipitated white powder was filtered off.

The filtered white powder was washed twice as a slurry with 2000 g of isopropyl alcohol, filtered, and dried at 60 ° C. for 17 hours to obtain a white powder polymer (85 g, 85% yield). ). This polymer has Mw of 7600, and as a result of ¹³ C-NMR analysis, the content of each repeating unit derived from the compound (12-1), the compound (12-2) and the compound (12-3) is 53. The copolymer was 1: 8.5: 38.4 (mol%). This polymer is referred to as “polymer (A-1)”.

Example 2
Compound (12-1) 54.99 g (50 mol%), compound (13-2) 8.92 g (10 mol%), compound (12-3) 36.08 g (40 mol%) into 2-butanone 187 g A dissolved monomer solution (1) and a solution (2) in which 3.37 g of dimethyl 2,2′-azobis (2-methylpropionate) was dissolved in 64 g of 2-butanone were prepared, and the above-described (α- 1) 28.77 g of the monomer solution (1) prepared previously and 4.23 g of the solution (2) were charged into a 1000 ml three-necked flask charged with 2.96 g of the compound represented by 1) and 15 g of 2-butanone, Thereafter, nitrogen purge was performed by a vacuum replacement method. After purging with nitrogen, the inside of the three-necked flask was heated to 80 ° C. with stirring. After 15 minutes, 258.98 g of the monomer solution (1) and 24.64 g of the solution (2) were added over 3 hours using a liquid feed pump. And 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, 11.39 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 was allowed to cool, cooled to 30 ° C. or lower, poured into 4000 g of isopropyl alcohol, and the precipitated white powder was filtered off.

The filtered white powder was washed twice as a slurry with 2000 g of isopropyl alcohol, filtered, and dried at 60 ° C. for 17 hours to obtain a white powder polymer (82 g, yield 82%). ). This polymer has Mw of 7500, and as a result of ¹³ C-NMR analysis, the content of each repeating unit derived from compound (12-1), compound (13-2), and compound (12-3) is 52. 5: 8.3: 39.2 (mol%) copolymer. This polymer is referred to as “polymer (A-2)”.

Example 3
Compound (12-1) 53.25 g (50 mol%), compound (14-2) 11.80 g (10 mol%), compound (12-3) 34.93 g (40 mol%) into 2-butanone 187 g A dissolved monomer solution (1) and a solution (2) in which 3.37 g of dimethyl 2,2′-azobis (2-methylpropionate) was dissolved in 64 g of 2-butanone were prepared, and the above-described (α- 1) 28.77 g of the monomer solution (1) prepared previously and 4.23 g of the solution (2) were charged into a 1000 ml three-necked flask charged with 2.96 g of the compound represented by 1) and 15 g of 2-butanone, Thereafter, nitrogen purge was performed by a vacuum replacement method. After purging with nitrogen, the inside of the three-necked flask was heated to 80 ° C. with stirring. After 15 minutes, 258.98 g of the monomer solution (1) and 24.64 g of the solution (2) were added over 3 hours using a liquid feed pump. And 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, 11.03 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 was allowed to cool, cooled to 30 ° C. or lower, poured into 4000 g of isopropyl alcohol, and the precipitated white powder was filtered off.

The filtered white powder was washed twice as a slurry with 2000 g of isopropyl alcohol, filtered, and dried at 60 ° C. for 17 hours to obtain a white powder polymer (84 g, yield 84%). ). This polymer has Mw of 7400, and as a result of ¹³ C-NMR analysis, the content of each repeating unit derived from the compound (12-1), the compound (14-2) and the compound (12-3) is 54. The copolymer was 1: 7.5: 38.4 (mol%). This polymer is referred to as “polymer (A-3)”.

Example 4
Compound (12-1) 52.52 g (50 mol%), compound (12-2) 10.40 g (10 mol%), compound (15-3) 37.09 g (40 mol%) into 2-butanone 187 g A dissolved monomer solution (1) and a solution (2) in which 3.37 g of dimethyl 2,2′-azobis (2-methylpropionate) was dissolved in 64 g of 2-butanone were prepared, and the above-described (α- 1) 28.77 g of the monomer solution (1) prepared previously and 4.23 g of the solution (2) were charged into a 1000 ml three-necked flask charged with 2.96 g of the compound represented by 1) and 15 g of 2-butanone, Thereafter, nitrogen purge was performed by a vacuum replacement method. After purging with nitrogen, the inside of the three-necked flask was heated to 80 ° C. with stirring. After 15 minutes, 258.98 g of the monomer solution (1) and 24.64 g of the solution (2) were added over 3 hours using a liquid feed pump. And 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, 10.87 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 was allowed to cool, cooled to 30 ° C. or lower, poured into 4000 g of isopropyl alcohol, and the precipitated white powder was filtered off.

The filtered white powder was washed twice as a slurry with 2000 g of isopropyl alcohol, filtered, and dried at 60 ° C. for 17 hours to obtain a white powder polymer (85 g, 85% yield). ). This polymer has Mw of 7600, and as a result of ¹³ C-NMR analysis, the content of each repeating unit derived from the compound (12-1), the compound (12-2) and the compound (15-3) is 55. The copolymer was 2: 8.3: 36.5 (mol%). This polymer is referred to as “polymer (A-4)”.

Example 5
Compound (12-1) 55.44 g (50 mol%), compound (12-2) 10.98 g (10 mol%), compound (16-3) 33.57 g (40 mol%) into 2-butanone 187 g A dissolved monomer solution (1) and a solution (2) in which 3.37 g of dimethyl 2,2′-azobis (2-methylpropionate) was dissolved in 64 g of 2-butanone were prepared, and the above-described (α- 1) 28.77 g of the monomer solution (1) prepared previously and 4.23 g of the solution (2) were charged into a 1000 ml three-necked flask charged with 2.96 g of the compound represented by 1) and 15 g of 2-butanone, Thereafter, nitrogen purge was performed by a vacuum replacement method. After purging with nitrogen, the inside of the three-necked flask was heated to 80 ° C. with stirring. After 15 minutes, 258.98 g of the monomer solution (1) and 24.64 g of the solution (2) were added over 3 hours using a liquid feed pump. And 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, 11.48 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 as a slurry with 2000 g of isopropyl alcohol, filtered, and dried at 60 ° C. for 17 hours to obtain a white powder polymer (87 g, yield 87%). ). This polymer has Mw of 7300, and as a result of ¹³ C-NMR analysis, the content of each repeating unit derived from the compound (12-1), the compound (12-2) and the compound (16-3) is 55. The copolymer was 5: 8.5: 36.0 (mol%). This polymer is referred to as “polymer (A-5)”.

Example 6
Compound (12-1) 53.93 g (50 mol%), compound (12-2) 10.68 g (10 mol%), compound (17-3) 35.38 g (40 mol%) to 2-butanone 187 g A dissolved monomer solution (1) and a solution (2) in which 3.37 g of dimethyl 2,2′-azobis (2-methylpropionate) was dissolved in 64 g of 2-butanone were prepared, and the above-described (α- 1) 28.77 g of the monomer solution (1) prepared previously and 4.23 g of the solution (2) were charged into a 1000 ml three-necked flask charged with 2.96 g of the compound represented by 1) and 15 g of 2-butanone, Thereafter, nitrogen purge was performed by a vacuum replacement method. After purging with nitrogen, the inside of the three-necked flask was heated to 80 ° C. with stirring. After 15 minutes, 258.98 g of the monomer solution (1) and 24.64 g of the solution (2) were added over 3 hours using a liquid feed pump. And 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, 11.17 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 was allowed to cool, cooled to 30 ° C. or lower, poured into 4000 g of isopropyl alcohol, and the precipitated white powder was filtered off.

The filtered white powder was washed twice as a slurry with 2000 g of isopropyl alcohol, filtered, and dried at 60 ° C. for 17 hours to obtain a white powder polymer (82 g, yield 82%). ). This polymer has Mw of 7700, and as a result of ¹³ C-NMR analysis, the content of each repeating unit derived from the compound (12-1), the compound (12-2) and the compound (17-3) is 54. The copolymer was 2: 8.2: 37.6 (mol%). This polymer is referred to as “polymer (A-6)”.

Example 7
Compound (12-1) 47.79 g (50 mol%), compound (12-2) 9.47 g (10 mol%), compound (18-3) 42.73 g (40 mol%) into 2-butanone 187 g A dissolved monomer solution (1) and a solution (2) in which 3.37 g of dimethyl 2,2′-azobis (2-methylpropionate) was dissolved in 64 g of 2-butanone were prepared, and the above-described (α- 1) 28.77 g of the monomer solution (1) prepared previously and 4.23 g of the solution (2) were charged into a 1000 ml three-necked flask charged with 2.96 g of the compound represented by 1) and 15 g of 2-butanone, Thereafter, nitrogen purge was performed by a vacuum replacement method. After purging with nitrogen, the inside of the three-necked flask was heated to 80 ° C. with stirring. After 15 minutes, 258.98 g of the monomer solution (1) and 24.64 g of the solution (2) were added over 3 hours using a liquid feed pump. And 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 was allowed to cool, cooled to 30 ° C. or lower, poured into 4000 g of isopropyl alcohol, and the precipitated white powder was filtered off.

The filtered white powder was washed twice as a slurry with 2000 g of isopropyl alcohol, filtered, and dried at 60 ° C. for 17 hours to obtain a white powder polymer (83 g, 83% yield). ). This polymer has Mw of 7700, and as a result of ¹³ C-NMR analysis, the content of each repeating unit derived from the compound (12-1), the compound (12-2) and the compound (18-3) is 55. The copolymer was 1: 8.5: 36.4 (mol%). This polymer is referred to as “polymer (A-7)”.

Example 8
Compound (12-1) 53.92 g (50 mol%), compound (12-2) 10.69 g (10 mol%), compound (12-3) 35.38 g (40 mol%) into 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) was dissolved in 160 g of 2-butanone were prepared, and the above-described (CTA- 3) 28.77 g of the monomer solution (1) prepared previously and 10.58 g of the solution (2) were charged into a 1000 ml three-necked flask charged with 7.04 g of the compound represented by 3) and 38 g of 2-butanone, Thereafter, nitrogen purge was performed by a vacuum replacement method. After purging with nitrogen, the inside of the three-necked flask was heated to 80 ° C. with stirring. After 15 minutes, 258.98 g of the monomer solution (1) and 61.06 g of the solution (2) were added over 3 hours using a feed pump. And 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, 11.17 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 was allowed to cool, cooled to 30 ° C. or lower, poured into 4000 g of isopropyl alcohol, and the precipitated white powder was filtered off.

The filtered white powder was washed twice as a slurry with 2000 g of isopropyl alcohol, filtered, and dried at 60 ° C. for 17 hours to obtain a white powder polymer (70 g, yield 70%). ). This polymer has Mw of 4100, and as a result of ¹³ C-NMR analysis, the content of each repeating unit derived from the compound (12-1), the compound (12-2) and the compound (12-3) is 54. The copolymer was 1: 8.1: 37.8 (mol%). This polymer is referred to as “polymer (A-8)”.

Example 9
Compound (12-1) 53.92 g (50 mol%), compound (12-2) 10.69 g (10 mol%), compound (12-3) 35.38 g (40 mol%) into 2-butanone 187 g A dissolved monomer solution (1) and a solution (2) in which 3.37 g of dimethyl 2,2′-azobis (2-methylpropionate) was dissolved in 64 g of 2-butanone were prepared, and the above-described (α- 1) 28.77 g of the monomer solution (1) prepared previously and 4.23 g of the solution (2) were charged into a 1000 ml three-necked flask charged with 2.96 g of the compound represented by 1) and 15 g of 2-butanone, Thereafter, nitrogen purge was performed by a vacuum replacement method. After purging with nitrogen, the inside of the three-necked flask was heated to 80 ° C. with stirring. After 15 minutes, 258.98 g of the monomer solution (1) and 24.64 g of the solution (2) were added over 3 hours using a liquid feed pump. And dripped. After completion of the dropwise addition, the mixture was further stirred for 4 hours. After completion of the polymerization, the solution was allowed to cool, cooled to 30 ° C. or lower, poured into 4000 g of isopropyl alcohol, and the precipitated white powder was filtered off.

The filtered white powder was washed twice as a slurry with 2000 g of isopropyl alcohol, filtered, and dried at 60 ° C. for 17 hours to obtain a white powder polymer (87 g, yield 87%). ). This polymer has Mw of 7300, and as a result of ¹³ C-NMR analysis, the content of each repeating unit derived from the compound (12-1), the compound (12-2) and the compound (12-3) is 54. 5: 8.3: 37.2 (mol%) copolymer. This polymer is referred to as “polymer (A-9)”.

Example 10
Compound (12-1) 52.52 g (50 mol%), compound (12-2) 10.40 g (10 mol%), compound (15-3) 37.09 g (40 mol%) into 2-butanone 187 g A dissolved monomer solution (1) and a solution (2) in which 3.37 g of dimethyl 2,2′-azobis (2-methylpropionate) was dissolved in 64 g of 2-butanone were prepared, and the above-described (α- 1) 28.77 g of the monomer solution (1) prepared previously and 4.23 g of the solution (2) were charged into a 1000 ml three-necked flask charged with 2.96 g of the compound represented by 1) and 15 g of 2-butanone, Thereafter, nitrogen purge was performed by a vacuum replacement method. After purging with nitrogen, the inside of the three-necked flask was heated to 80 ° C. with stirring. After 15 minutes, 258.98 g of the monomer solution (1) and 24.64 g of the solution (2) were added over 3 hours using a liquid feed pump. And 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 30 ° C. or lower, poured into 4000 g of isopropyl alcohol, and the precipitated white powder was filtered off.

The filtered white powder was washed twice as a slurry with 2000 g of isopropyl alcohol and then filtered and dried at 60 ° C. for 17 hours to obtain a white powder polymer (85 g, yield 85). %). This polymer has Mw of 7600, and as a result of ¹³ C-NMR analysis, the content of each repeating unit derived from the compound (12-1), the compound (12-2) and the compound (15-3) is 54. The copolymer was 3: 8.1: 37.6 (mol%). This polymer is referred to as “polymer (A-10)”.

Example 11 to Example 22
The respective polymers obtained in Examples 1 to 10, the acid generators shown below, and other components were blended in the proportions shown in Table 1 to obtain respective radiation-sensitive resin composition solutions. The obtained radiation-sensitive resin composition solution was exposed under the conditions shown in Table 2 and subjected to various evaluations. The evaluation results are shown in Table 3. Here, the part is based on weight unless otherwise specified.

Acid generator (B)
(B-1): Triphenylsulfonium nonafluoro-n-butanesulfonate Acid diffusion controller (C)
(C-1): 2-Phenylbenzimidazole Solvent (D)
(D-1): Propylene glycol methyl ether acetate (D-2): Cyclohexanone

Evaluation method (1) Sensitivity:
When exposure is performed with an ArF light source, a silicon wafer (ARC29) having an ARC29 film (made by Brewer Science) with a film thickness of 770 angstroms formed on the wafer surface is used, and each composition solution is applied onto the substrate by spin coating. A Nikon ArF excimer laser exposure apparatus (numerical aperture 0.75) is applied to a resist film having a film thickness of 0.25 μm formed by performing PB on the hot plate under the conditions shown in Table 2 through a mask pattern. And exposed. Thereafter, PEB was 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, an exposure amount for forming a line-and-space pattern (1L1S) having a line width of 0.11 μm in a one-to-one line width was defined as an optimum exposure amount, and this optimum exposure amount was defined as 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 lower side dimension L1 and the upper side dimension L2 of the rectangular cross section of the line-and-space pattern (1L1S) having a line width of 0.16 μm were measured with a scanning electron microscope, and 0.85 ≦ L2 / L1 ≦ 1 In addition, when the pattern profile has no bottom, the pattern profile is determined to be “good”.
(4) Line edge roughness (LER):
When observing the 110nm 1L / 1S pattern resolved at the optimum exposure dose, the line width is observed at an arbitrary point when the length is observed from the top of the pattern with Hitachi SEM: S9220, and the measurement variation is evaluated with 3 sigma. did.

  As shown in Table 3, a radiation-sensitive resin composition excellent in resolution, pattern profile, and line edge roughness (LER) characteristics as basic resist performances was obtained.

  Since the radiation-sensitive resin composition of the present invention is excellent in line edge roughness (LER) characteristics, it is extremely useful as a chemically amplified resist for semiconductor device production, which is expected to be further refined from now on. The acid-dissociable group-containing polymer of the present invention can be suitably used for such a resin composition and is useful. The chain transfer agent of the present invention can be suitably used for the production of such a resin composition and is useful. The pyrazole derivative of the present invention can be suitably used as such a chain transfer agent and is useful.

It is a conceptual diagram which shows the relationship between superposition | polymerization time and molecular weight.

Claims (7)

A pyrazole derivative represented by the formula (1).

[In Formula (1), R is mutually independently a C1-C20 substituted or unsubstituted alkyl group, a C3-C20 substituted or unsubstituted alicyclic group, C2-C20. A substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group is shown, and n is an integer of 0 to 3. R ¹ represents a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted alicyclic group having 3 to 20 carbon atoms. R ² and R ³ are substituted or unsubstituted alkyl groups having 1 to 20 carbon atoms, substituted or unsubstituted alicyclic groups having 3 to 20 carbon atoms, substituted or unsubstituted alkenyl groups having 2 to 20 carbon atoms, A substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group is shown. R ² and R ³ may be bonded to each other to form one or more rings. ]   A chain transfer agent for living radical polymerization comprising the pyrazole derivative according to claim 1. An acid-dissociable group-containing polymer comprising a repeating unit represented by the formula (2) and a repeating unit having an acid-dissociable group, wherein the polymer is a living radical using the chain transfer agent according to claim 2. An acid-dissociable group-containing polymer obtained by polymerization.

[In the formula (2), R ⁴ represents a hydrogen atom, a methyl group, or a trifluoromethyl group, and X represents a polycyclic alicyclic ring composed of only a carbon atom and a hydrogen atom not containing a polar group having 4 to 20 carbon atoms. Represents a hydrocarbon group. ] The acid dissociable group-containing polymer according to claim 3, wherein the acid dissociable group-containing polymer further comprises a repeating unit represented by the formula (3).

In [Equation (3), R ⁵ is a hydrogen atom, a methyl group or a trifluoromethyl group,, R ⁶ independently of one another, a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms Represents a linear or branched alkoxy group having 1 to 4 carbon atoms, or a linear or branched fluorinated alkyl group having 1 to 4 carbon atoms. n is an integer of 0-3. ] The repeating unit having the acid dissociable group is at least one repeating unit selected from the repeating unit represented by the formula (4) and the repeating unit represented by the formula (5). Acid dissociable group-containing polymer.

[In the formulas (4) and (5), R ⁷ and R ¹¹ each represent a hydrogen atom, a methyl group, or a trifluoromethyl group, and R ⁸ and R ⁹ are each independently a straight chain having 1 to 4 carbon atoms. A chain or branched alkyl group, R ¹⁰ represents an alicyclic hydrocarbon group having 4 to 20 carbon atoms, R ¹² represents a linear or branched alkyl group having 1 to 4 carbon atoms, R ¹³ and R ¹⁴ each independently represent a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms, and n represents an integer of 3 to 7. ]   The acid-dissociable group-containing polymer according to any one of claims 3 to 5, wherein the acid-dissociable group-containing polymer has residues derived from the chain transfer agent at all or part of molecular chain terminals.   The radiation sensitive resin composition containing the acid dissociable group containing polymer of any one of Claims 3-6, and a radiation sensitive acid generator.

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