JP2008291110A - Method for manufacturing resin, resin manufactured by the manufacturing method, resist composition containing the resin and pattern-forming method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a resin which can prepare a resist composition having improved line edge roughness even in the formation of a fine pattern (particularly a line width of 100 nm or less), is decomposed by the action of an acid, and increases the solubility in an alkali developer, a resin manufactured by the manufacturing method, a resist composition containing the resin, and a pattern-forming method using the same. <P>SOLUTION: In the method for manufacturing a resin (A) which is decomposed by the action of an acid and increases the solubility in an alkali developer by polymerization, a compound having a specific sulfone structure is used as a solvent. The resin is manufactured by the manufacturing method. The resist composition contains the resin and the pattern-forming method uses the same. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for producing a resin, a resin produced by the production method, a resin produced by the production method of a semiconductor substrate such as an IC, a circuit board such as a liquid crystal or a thermal head, and other photofabrication steps. And a pattern forming method using the same. More specifically, a resin production method suitable for use as an exposure light source such as far ultraviolet light of 250 nm or less, preferably 220 nm or less, and an irradiation source using an electron beam, the resin produced by the production method, and the resin are contained. The present invention relates to a resist composition and a pattern forming method using the same.

  The chemically amplified photosensitive composition generates an acid in the exposed area by irradiation with radiation such as far ultraviolet light, and the acid-catalyzed reaction causes the solubility of the active radiation irradiated area and non-irradiated area in the developer. This is a pattern forming material for changing the pattern to form a pattern on the substrate.

  When a KrF excimer laser is used as an exposure light source, a resin having a basic skeleton of poly (hydroxystyrene) having a small absorption mainly in the 248 nm region is used as a main component. A pattern is formed, which is a better system than the conventional naphthoquinone diazide / novolak resin system.

On the other hand, when a further short wavelength light source, for example, an ArF excimer laser (193 nm) is used as an exposure light source, the compound having an aromatic group exhibits a large absorption in the 193 nm region. It wasn't.
Therefore, an ArF excimer laser resist containing a highly transparent methacrylate resin in a wavelength region of 200 nm or less has been developed. For example, Patent Document 1 (Japanese Patent Laid-Open No. 4-226461) describes a resist composition containing an acid-decomposable resin having a methacrylate structure. However, with the miniaturization of patterns, it is necessary to reduce the resist film thickness, and resist dry etching resistance is required. Patent Document 2 (Japanese Patent Application Laid-Open No. 10-307400) describes a resin containing a repeating unit having a bridged alicyclic hydrocarbon such as an adamantane structure. However, the dry etching resistance can be improved by increasing the carbon density, but when forming a fine pattern having a line width of 100 nm or less, the line edge roughness performance of the line pattern tends to be reduced. Improvements were sought.
Here, the line edge roughness means that the resist line pattern and the edge of the substrate interface exhibit irregular shapes in a direction perpendicular to the line direction due to the characteristics of the resist. When this pattern is observed from directly above, the edges appear to be uneven (± several nm to several tens of nm). Since the unevenness is transferred to the substrate by an etching process, if the unevenness is large, an electrical characteristic defect is caused and the yield is lowered.
In order to improve dry etching resistance, it is necessary to increase the carbon density of the monomer. However, when polymerization is performed using a monomer having a high carbon density and a hydrophobic group such as an alicyclic group and a polar group such as a hydroxyl group. The problem that solvent solubility deteriorates has occurred. In Patent Document 2, tetrahydrofuran, 2-butanone, and the like are used as a polymerization solvent used for producing a resist resin. Further, Patent Document 3 (Japanese Patent Application Laid-Open No. 2004-175981) describes a cyclic ketone solvent as a polymerization solvent for improving the solvent solubility of the monomer. However, depending on the monomer type, the solvent solubility may be deteriorated. As a result, the line edge roughness performance of the line pattern was not sufficient.

JP-A-4-226461 Japanese Patent Laid-Open No. 10-307400 JP 2004-175981 A

  Accordingly, an object of the present invention is to prepare a resist composition with improved line edge roughness even in the formation of a fine pattern (particularly, a line width of 100 nm or less). It is in providing the manufacturing method of resin which increases the solubility in, the resin manufactured by this manufacturing method, the resist composition containing this resin, and the pattern formation method using the same.

  As a result of intensive studies, the present inventors have improved the line edge roughness of the resist composition using the obtained resin by using a specific solvent when the resin used in the resist composition is produced by polymerization. As a result, the present invention has been completed.

  The present invention is as follows.

  (1) Production of a resin that is decomposed by the action of an acid and has increased solubility in an alkaline developer by polymerizing the monomer in the presence of the compound represented by the following general formula (I) as a solvent. A method for producing a resin.

In general formula (I),
R ₁ and R ₂ each independently represents an alkyl group, an alkenyl group, a cycloalkyl group, a cycloalkenyl group, an aryl group, a heterocyclic group, or an amino group. R ₁ and R ₂ may be linked to form a ring.

(2) The method for producing a resin according to (1), wherein R ₁ and R ₂ in the general formula (I) are alkyl groups.

  (3) The method for producing a resin according to (1) or (2), wherein the resin has a repeating unit having an acid-decomposable group having an alicyclic hydrocarbon structure.

  (4) The method for producing a resin according to any one of (1) to (3), wherein the resin has a repeating unit having a lactone structure.

  (5) The method for producing a resin according to any one of (1) to (4), wherein the resin has a repeating unit having an alicyclic hydrocarbon structure substituted with a polar group.

  (6) A resin which is produced by the action of an acid, which is produced by the method according to any one of (1) to (5) and has increased solubility in an alkali developer.

  (7) A resin that decomposes by the action of an acid as described in (6) and increases the solubility in an alkaline developer, and a compound that generates an acid upon irradiation with actinic rays or radiation. Resist composition.

  (8) A pattern forming method comprising: forming a resist film using the resist composition according to (7); and exposing and developing the resist film.

  According to the present invention, a resist composition with improved line edge roughness can be prepared even in the formation of a fine pattern (particularly, a line width of 100 nm or less). The resist composition is decomposed by the action of an acid and has a solubility in an alkali developer. It is possible to provide an increasing resin production method, a resin produced by the production method, a resist composition containing the resin, and a pattern formation method using the same.

Hereinafter, the best mode for carrying out the present invention will be described.
In addition, in the description of the group (atomic group) in this specification, the description which does not describe substitution and non-substitution includes what does not have a substituent and what has a substituent. . For example, the “alkyl group” includes not only an alkyl group having no substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group).

Compound represented by general formula (I) In the present invention, a monomer is polymerized in the presence of a compound represented by the following general formula (I) as a solvent to decompose by the action of an acid, and in an alkaline developer. A resin with increased solubility of is produced.

In general formula (I),
R ₁ and R ₂ each independently represents an alkyl group, an alkenyl group, a cycloalkyl group, a cycloalkenyl group, an aryl group, a heterocyclic group, or an amino group. R ₁ and R ₂ may be linked to form a ring.

In general formula (I), R ₁ and R ₂ , the alkyl group is preferably an alkyl group having 1 to 30 carbon atoms, more preferably an alkyl group having 1 to 20 carbon atoms, and an alkyl group having 1 to 10 carbon atoms. The group is particularly preferred. Examples of the alkyl group include, for example, methyl group, ethyl group, n-propyl group, isopropyl group, t-butyl group, sec-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n- An octyl group etc. can be mentioned.

The alkenyl group in R ₁ and R ₂ is preferably an alkenyl group having 2 to 30 carbon atoms. Examples of the alkenyl group include an allyl group, a prenyl group, a geranyl group, and an oleyl group.

The cycloalkyl group in R ₁ and R ₂ is preferably a cycloalkyl group having 3 to 30 carbon atoms, and examples thereof include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and a cyclododecyl group.

The cycloalkenyl group in R ₁ and R ₂ is preferably a cycloalkenyl group having 3 to 30 carbon atoms, for example, a monocycloalkenyl such as a 2-cyclopenten-1-yl group and a 2-cyclohexen-1-yl group. In addition to the group, a polycycloalkenyl group such as a bicycloalkenyl group (preferably a substituted or unsubstituted bicycloalkenyl group having 5 to 30 carbon atoms such as bicyclo [2,2,1] hept-2-ene -1-yl group, bicyclo [2,2,2] oct-2-en-4-yl group) and tricycloalkenyl group.

The aryl group in R ₁ and R ₂ is preferably an aryl group having 6 to 30 carbon atoms, such as a phenyl group, p-tolyl group, naphthyl group, m-chlorophenyl group, o-hexadecanoylaminophenyl, etc. Is mentioned.

The heterocyclic group in R ₁ and R ₂ is preferably a heterocyclic group having 5 to 30 carbon atoms. For example, a 2-furyl group, a 2-thienyl group, a 2-pyridyl group, a 4-pyridyl group, 2- Examples include a pyrimidinyl group and a 2-benzothiazolyl group.

The amino group in R ₁ and R ₂ is preferably an amino group having 0 to 30 carbon atoms, such as an amino group, a methylamino group, a dimethylamino group, a diethylamino group, an anilino group, an N-methyl-anilino group, A diphenylamino group, N-1,3,5-triazin-2-ylamino and the like can be mentioned.

When R ₁ and R ₂ are connected to form a ring, examples of the group formed by connecting R ₁ and R ₂ include an alkylene group having 1 to 10 carbon atoms.

R ₁ and R ₂ are particularly preferably an alkyl group having 1 to 10 carbon atoms.
R ₁ and R ₂ are preferably connected to form a ring.

  As the compound represented by formula (I), any commercially available compound can be used. When the compound represented by the general formula (I) is solid at normal temperature (10 to 30 ° C.), it may be used by dissolving it by heating, or by dissolving it by mixing with another solvent. The compound represented by the general formula (I) is preferably a compound having a cyclic structure.

  Examples of the compound represented by the general formula (I) include, for example, dimethyl sulfone, diethyl sulfone, di-n-propyl sulfone, di-n-butyl sulfone, di-n-octyl sulfone, ethyl methyl sulfone, isopropyl methyl. Examples include sulfone and tetrahydrothiophene-1,1-dioxide (hereinafter, also referred to as “sulfolane”).

In the present invention, only one type of compound represented by the general formula (I) may be used as a solvent, or two or more types may be used in combination. In the present invention, only a compound represented by general formula (I) may be used as a solvent, or a compound represented by general formula (I) and represented by general formula (I). A compound different from the compound may be used in combination. When a compound different from the compound represented by formula (I) is used in combination, the proportion of the compound represented by formula (I) in the total solvent is preferably 10 to 100% by mass, more preferably 10%. It is -90 mass%, More preferably, it is 10-70 mass%. More preferably, it is 15-60 mass%, Most preferably, it is 20-50 mass%. By setting the ratio of the compound represented by the general formula (I) to 10% by mass or more, it is possible to prevent the solubility of the monomer from being lowered, resulting in heterogeneous polymerization, and the effect of improving the line edge roughness being reduced.
As the compound different from the compound represented by the general formula (I), any compound generally used as a solvent can be used.
Specifically, for example, ketone compounds such as 2-heptanone, methyl ethyl ketone, cyclohexanone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, etc. Alkylene glycol compounds, ester compounds such as ethyl acetate, methyl lactate, ethyl lactate, methyl methoxypropionate, ethyl ethoxypropionate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, 2-methoxyethyl acetate, γ-butyrolactone , Hydrocarbon compounds such as toluene, halogenated hydrocarbon compounds such as ethylene dichloride, N, N-dimethylformamide Nitrogen-based compounds, sulfur-based compounds such as dimethyl sulfoxide, ether compounds such as tetrahydrofuran. These compounds are preferably used because they are excellent in solubility of each monomer when mixed with the compound represented by formula (I).

The reason why a resist having a low line edge roughness can be obtained by the present invention is not necessarily clear, but the following reasons are conceivable.
Conventionally, tetrahydrofuran, methyl ethyl ketone, methyl isopropyl ketone, methyl isobutyl ketone, and the like have been used as a solvent for dissolving monomers during radical polymerization. Since these solvents are not compatible with various monomers having different polarities, when two or more types of monomers having different polarities are mixed and used, the distribution of each monomer in the solvent is different due to the difference in polarity. It is considered that a heterogeneous portion in which monomers having the same polarity are polymerized is formed in the obtained polymer without being uniform. When a resist pattern is formed using such a polymer as a resist resin, the alkali solubility varies depending on the polymer, so that the dissolution of the exposed portion in the developer becomes uneven and the line edge roughness of the resist pattern obtained after development is poor. It is considered to be.
In the present invention, the compound represented by the general formula (I) is excellent in compatibility with various monomers having different polarities, and as a result, the distribution of each monomer during polymerization is uniform, and heterogeneous polymerization is suppressed. It is considered that the line edge roughness of the resist pattern is improved.

Resin Production Method In the resin production method of the present invention, a mixture of various monomers is polymerized using a polymerization initiator in the presence of a compound represented by the following general formula (I) as a solvent, thereby producing an acid. A resin (hereinafter also referred to as “acid-decomposable resin”) that is decomposed by the action and has increased solubility in an alkaline developer is produced.
The acid-decomposable resin can be synthesized according to a conventional method (for example, radical polymerization). For example, as a general synthesis method, a monomer polymerization method and a polymerization initiator are dissolved in a solvent containing a compound represented by the general formula (I) as a solvent and heated to perform polymerization, and as a solvent, A solvent containing the compound represented by the general formula (I) is heated, and a dropping polymerization method and the like in which a solution of a monomer species and a polymerization initiator is added dropwise over 1 to 10 hours;
The dropping polymerization method is preferred.
The compound represented by the general formula (I) is excellent in compatibility with any of the monomer mixture, the polymerization initiator and the obtained copolymer, and suppresses the nonuniformity of distribution of various structural units in the obtained copolymer. Is done.

As a polymerization initiator, a commercially available radical initiator (azo initiator, peroxide, etc.) is used to initiate the polymerization. As the radical initiator, an azo initiator is preferable, and an azo initiator having an ester group, a cyano group, or a carboxyl group is preferable. Preferred polymerization initiators include azobisisobutyronitrile (AIBN), 2,2′-azobis (2,4-dimethylvaleronitrile, 2,2′-azobis (2-methylbutyronitrile), 1,1 '-Azobis (cyclohexane-1-carbonitrile), dimethyl 2,2'-azobis (2-methylpropionate), 4,4'-azobis (4-cyanovalerate), tert-butyl peroctoate, 1, Examples thereof include 1'-azobis- (cyclohexane-1-carbonitrile, 1-[(1-diazo-1-methylethyl) azo] formamide, etc. A particularly preferred polymerization initiator is azobisisobutyronitrile. , Dimethyl 2,2′-azobis (2-methylpropionate), etc. Each of them can be used alone or in combination.
A chain transfer agent such as a thiol compound may be used in combination with the polymerization initiator. If desired, an initiator may be added or added in portions.
The usage-amount of a polymerization initiator is not restrict | limited in particular, For example, it is 0.1-10 mass parts with respect to 100 mass parts of monomers, Preferably it is 1-5 mass parts.

The concentration of solutes such as monomers, polymerization initiators, chain transfer agents and the like in the reaction solution is preferably 5 to 50% by mass, more preferably 10 to 30 from the viewpoint that the mass average molecular weight of the obtained resin can be easily controlled. % By mass. The reaction temperature is usually 10 ° C to 150 ° C, preferably 30 ° C to 120 ° C, more preferably 60-100 ° C.
The polymerization reaction is preferably performed in an inert gas atmosphere such as nitrogen or argon.

  The reaction solution containing the resin thus obtained is dropped into a large amount of these solvents using a single or mixed solvent such as hexane, heptane, ethyl acetate, isopropanol, methanol, water, etc. to precipitate the resin. . Then, the acid-decomposable resin of the present invention can be obtained by filtering, washing and drying the obtained precipitate. Although this step may be unnecessary depending on circumstances, it is effective for removing unreacted monomers (monomers), polymerization initiators and the like remaining in the reaction solution. If these unreacted substances remain as they are, there is a possibility that the resist performance may be adversely affected.

The weight average molecular weight of the acid-decomposable resin according to the present invention is preferably 1,000 to 200,000, more preferably 3,000 to 20,000, most preferably 5, as a polystyrene conversion value by GPC method. 000 to 15,000. By setting the weight average molecular weight to 1,000 to 200,000, deterioration of heat resistance and dry etching resistance can be prevented, developability is deteriorated, and viscosity is increased, resulting in deterioration of film forming property. Can be prevented.
The molecular weight distribution (Mw / Mn) is usually 1 to 5, preferably 1 to 2, more preferably 1.3 to 2. The smaller the molecular weight distribution, the better the resolution and the resist shape, and the smoother the side wall of the resist pattern, the better the roughness.
The structure of the acid-decomposable resin is not particularly limited, and may be any of a random copolymer, a block copolymer, and an alternating copolymer.

Next, the acid-decomposable resin obtained by the production method of the present invention will be described.
The acid-decomposable resin has a group that is decomposed by the action of an acid to generate an alkali-soluble group (hereinafter also referred to as “acid-decomposable group”).
The acid-decomposable resin may have an acid-decomposable group in the main chain or side chain of the resin, or in both the main chain and the side chain, but preferably in the side chain.
A preferred group as the acid-decomposable group is a group in which a hydrogen atom of an alkali-soluble group such as a —COOH group or a —OH group is substituted with a group capable of leaving with an acid.
Examples of the group leaving with an acid include -C (R ₃₆ ) (R ₃₇ ) (R ₃₈ ), -C (R ₃₆ ) (R ₃₇ ) (OR ₃₉ ), -C (R ₀₁ ) (R ₀₂ ). ) (OR ₃₉ ) and the like.
In the formula, R _{36 to} R ₃₉ each independently represents an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or an alkenyl group. R ₃₆ and R ₃₇ , R ₃₆ and R ₃₉ may be bonded to each other to form a ring.
R _{01 and} R ₀₂ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group or an alkenyl group.
In the present invention, the acid-decomposable group is preferably an acetal group or a tertiary ester group.

When irradiating ArF excimer laser light to the resist composition of the present invention containing an acid-decomposable resin, the acid-decomposable resin has a monocyclic or polycyclic alicyclic hydrocarbon structure, and acts by the action of an acid. A resin that decomposes and increases the solubility in an alkaline developer is preferred.
Resins having a monocyclic or polycyclic alicyclic hydrocarbon structure, which are decomposed by the action of an acid and have increased solubility in an alkaline developer, are represented by the following general formulas (pI) to (pV). It is preferable that it is resin which has at least 1 sort (s) selected from the repeating unit which has the partial structure containing the alicyclic hydrocarbon and the repeating unit shown by following general formula (II-AB).

In the general formulas (pI) to (pV),
R ₁₁ represents an alkyl group.
Z represents an atomic group necessary for forming a cycloalkyl group together with a carbon atom.
R _{12 to} R ₁₄ each independently represents an alkyl group or a cycloalkyl group. However, at least one of R _{12 to} R ₁₄ is preferably a cycloalkyl group.
R ₁₅ and R ₁₆ each independently represents an alkyl group or a cycloalkyl group. However, either R ₁₅ or R ₁₆ is preferably a cycloalkyl group.
R _{17 to} R ₂₁ each independently represents a hydrogen atom, an alkyl group or a cycloalkyl group. However, at least one of R _{17 to} R ₂₁ is preferably a cycloalkyl group. Moreover, any of R ₁₉ and R ₂₁ represents an alkyl group or a cycloalkyl group.
R _{22 to} R ₂₅ each independently represents a hydrogen atom, an alkyl group or a cycloalkyl group. However, at least one of R _{22 to} R ₂₅ is preferably a cycloalkyl group. R ₂₃ and R ₂₄ may be bonded to each other to form a ring.

In general formula (II-AB):
R ₁₁ ′ and R ₁₂ ′ each independently represents a hydrogen atom, a cyano group, a halogen atom or an alkyl group.
Z ′ represents an atomic group for forming an alicyclic structure containing two bonded carbon atoms (C—C).

  The general formula (II-AB) is more preferably the following general formula (II-AB1) or general formula (II-AB2).

In the general formulas (II-AB1) and (II-AB2),
R ₁₃ ′ to R ₁₆ ′ each independently represents a hydrogen atom, a halogen atom, a cyano group, —COOH, —COOR ₅ , an acid-decomposable group, —C (═O) —XA′—R ₁₇ ′, An alkyl group or a cycloalkyl group is represented. At least two _{members out of} R ₁₃ ′ to R ₁₆ ′ may combine to form a ring.
Here, R ₅ represents an alkyl group, a cycloalkyl group, or a group having a lactone structure.
X represents an oxygen atom, a sulfur atom, -NH -, - NHSO ₂ - or an -NHSO ₂ NH-.
A ′ represents a single bond or a divalent linking group.
R ₁₇ ′ represents —COOH, —COOR ₅ , —CN, a hydroxyl group, an alkoxy group, —CO—NH—R ₆ , —CO—NH—SO ₂ —R ₆ or a group having a lactone structure.
R ₆ represents an alkyl group or a cycloalkyl group.
n represents 0 or 1.

In the general formulas (pI) to (pV), the alkyl group in R _{11 to} R ₂₅ is preferably a linear or branched alkyl group having 1 to 4 carbon atoms, such as a methyl group, Examples thereof include an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a sec-butyl group.

The cycloalkyl group or the cycloalkyl group formed by Z and a carbon atom in R _{12 to} R ₂₅ may be monocyclic or polycyclic. Specific examples include groups having a monocyclo, bicyclo, tricyclo, tetracyclo structure or the like having 5 or more carbon atoms. The carbon number is preferably 6-30, and particularly preferably 7-25.

  Preferred cycloalkyl groups include adamantyl group, noradamantyl group, decalin residue, tricyclodecanyl group, tetracyclododecanyl group, norbornyl group, cedrol group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, A cyclodecanyl group, a cyclododecanyl group, etc. can be mentioned. More preferable examples include an adamantyl group, norbornyl group, cyclohexyl group, cyclopentyl group, tetracyclododecanyl group, and tricyclodecanyl group.

  These alkyl groups and cycloalkyl groups may have a substituent. As further substituents for alkyl groups and cycloalkyl groups, alkyl groups (1 to 4 carbon atoms), halogen atoms, hydroxyl groups, alkoxy groups (1 to 4 carbon atoms), carboxyl groups, alkoxycarbonyl groups (2 to 2 carbon atoms). 6). Examples of the substituent that the alkyl group, alkoxy group, alkoxycarbonyl group and the like may further have include a hydroxyl group, a halogen atom, and an alkoxy group.

  The structures represented by the general formulas (pI) to (pV) can be used as a protective group for an alkali-soluble group to form an acid-decomposable group. Examples of the alkali-soluble group include various groups known in this technical field.

Specific examples include a structure in which a hydrogen atom of a —COOH group, —OH group, —SO ₃ H group, or —SH group is substituted with a structure represented by the general formulas (pI) to (pV), A structure in which a hydrogen atom of a —COOH group or —OH group is substituted with a structure represented by general formulas (pI) to (pV) is preferable.

  As the repeating unit having an alkali-soluble group protected by a structure represented by the general formulas (pI) to (pV), a repeating unit represented by the following general formula (pA) is preferable.

In the general formula (pA),
R represents a hydrogen atom, a halogen atom, or a linear or branched alkyl group (preferably having 1 to 4 carbon atoms). A plurality of R may be the same or different.
A is selected from the group consisting of a single bond, an alkylene group, an ether group, a thioether group, a carbonyl group, an ester group, an amide group, a sulfonamide group, a urethane group or a urea group, or two or more of these Represents a combination of groups. Preferably, it is a single bond or —COO—CH ₂ —.
Rp ₁ represents any one of the general formulas (pI) to (pV).

  The repeating unit represented by the general formula (pA) is particularly preferably a repeating unit composed of 2-alkyl-2-adamantyl (meth) acrylate and dialkyl (1-adamantyl) methyl (meth) acrylate.

  Hereinafter, although the specific example of the repeating unit shown by general formula (pA) is shown, this invention is not limited to this.

In specific examples, Rx, H, represents a CH _3, CF ₃ or CH ₂ OH, Rxa and Rxb each independently represents an alkyl group (preferably having from 1 to 4 carbon atoms).

Examples of the halogen atom in the general formula (II-AB), R ₁₁ ′, and R ₁₂ ′ include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom.

As the alkyl group in R ₁₁ ′ and R ₁₂ ′, a linear or branched alkyl group having 1 to 10 carbon atoms is preferable.

  The atomic group for forming the alicyclic structure of Z ′ is an atomic group that forms a repeating unit of the alicyclic hydrocarbon in the resin, and in particular, forms a repeating unit of the bridged alicyclic hydrocarbon. An atomic group for forming a bridged alicyclic structure is preferred.

Examples of the skeleton of the alicyclic hydrocarbon formed include those similar to the cycloalkyl groups of R _{12 to} R _{25 in} the general formulas (pI) to (pV).

The alicyclic hydrocarbon skeleton may have a substituent. Examples of such a substituent include R ₁₃ ′ to R ₁₆ ′ in the general formula (II-AB1) or (II-AB2).

  Although the following specific examples are mentioned as a repeating unit represented by the said general formula (II-AB1) or general formula (II-AB2), This invention is not limited to these specific examples.

The acid-decomposable resin preferably has a lactone group. As the lactone group, any group having a lactone structure can be used, but a group having a 5- to 7-membered ring lactone structure is preferred, and a bicyclo structure or spiro is added to the 5- to 7-membered ring lactone structure. Those in which other ring structures are condensed to form a structure are preferred. The acid-decomposable resin more preferably has a repeating unit having a group having a lactone structure represented by any of the following general formulas (LC1-1) to (LC1-16). Further, a group having a lactone structure may be directly bonded to the main chain. Preferred lactone structures are (LC1-1), (LC1-4), (LC1-5), (LC1-6), (LC1-13), (LC1-14), and a specific lactone structure is used. As a result, line edge roughness and development defects are improved.

The lactone structure moiety may or may not have a substituent (Rb ₂ ). Preferred substituents (Rb ₂ ) include an alkyl group (preferably having 1 to 8 carbon atoms), a cycloalkyl group (preferably having 4 to 7 carbon atoms), an alkoxy group (preferably having 1 to 8 carbon atoms), and an alkoxycarbonyl group. (Preferably having 1 to 8 carbon atoms), carboxyl group, halogen atom, hydroxyl group, cyano group, acid-decomposable group and the like. n2 represents an integer of 0 to 4. When n2 is 2 or more, a plurality of substituents (Rb ₂ ) may be the same or different, and a plurality of substituents (Rb ₂ ) may be bonded to form a ring.

As the repeating unit having a group having a lactone structure represented by any of the general formulas (LC1-1) to (LC1-16), R _{13 in the} general formula (II-AB1) or (II-AB2) may be used. At least one of 'to R ₁₆ ' has a group represented by general formula (LC1-1) to (LC1-16) (for example, R _{5 of} -COOR ₅ is represented by general formula (LC1-1) to ( And a repeating unit represented by the following general formula (AI).

In general formula (AI),
Rb ₀ represents a hydrogen atom, a halogen atom or an alkyl group (preferably having 1 to 4 carbon atoms). Preferred substituents that the alkyl group represented by Rb ₀ may have include a hydroxyl group and a halogen atom.
Examples of the halogen atom for Rb ₀ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Rb ₀ is preferably a hydrogen atom or a methyl group.
Ab represents a single bond, an alkylene group, a divalent linking group having a monocyclic or polycyclic alicyclic hydrocarbon structure, an ether group, an ester group, a carbonyl group, a carboxyl group, or a divalent group obtained by combining these. . A linking group represented by a single bond or —Ab ₁ —CO ₂ — is preferable. Ab ₁ is a linear or branched alkylene group, a monocyclic or polycyclic cycloalkylene group, and preferably a methylene group, an ethylene group, a cyclohexyl group, an adamantyl group, or a norbornyl group.
V represents a group represented by any one of the general formulas (LC1-1) to (LC1-16).

  The repeating unit having a group having a lactone structure usually has an optical isomer, but any optical isomer may be used. One optical isomer may be used alone, or a plurality of optical isomers may be mixed and used. When one kind of optical isomer is mainly used, the optical purity (ee) thereof is preferably 90 or more, more preferably 95 or more.

  The content of the repeating unit having a group having a lactone structure is preferably from 15 to 60 mol%, more preferably from 20 to 50 mol%, still more preferably from 30 to 50 mol%, based on all repeating units in the polymer.

  Examples of the repeating unit having a group having a particularly preferred lactone structure include the following repeating units, but the present invention is not limited thereto. By selecting the optimum lactone structure, the pattern profile and the density dependence become good.

  The acid-decomposable resin preferably has a repeating unit having an alicyclic hydrocarbon structure substituted with a polar group. This improves the substrate adhesion and developer compatibility. The alicyclic hydrocarbon structure of the alicyclic hydrocarbon structure substituted with a polar group is preferably an adamantyl group, a diamantyl group, or a norbornane group. As the polar group, a hydroxyl group and a cyano group are preferable. As the alicyclic hydrocarbon structure substituted with a preferable polar group, groups represented by the following general formulas (VIIa) to (VIId) are preferable.

In general formulas (VIIa) to (VIIc),
R _{2c to} R _4c each independently represents a hydrogen atom, a hydroxyl group or a cyano group. However, at least one of R _{2c to} R _4c represents a hydroxyl group or a cyano group. Preferably, one or two of R _{2c to} R _4c are a hydroxyl group and the remainder is a hydrogen atom. In general formula (VIIa), more preferably, two of R _{2c to} R _4c are hydroxyl groups and the remaining are hydrogen atoms.

As the repeating unit having a group represented by the general formulas (VIIa) to (VIId), at least one of R ₁₃ ′ to R ₁₆ ′ in the general formula (II-AB1) or (II-AB2) is the above. Those having groups represented by general formulas (VIIa) to (VIId) (for example, R _{5 in} —COOR ₅ represents groups represented by general formulas (VIIa) to (VIId)) or the following general formula (AIIa) The repeating unit represented by-(AIId) can be mentioned.

In the general formulas (AIIa) to (AIId),
R _1c represents a hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl group.
R _2c to R _4c are in the general formula (VIIa) ~ (VIIc), same meanings as R _2c to R _4c.

  The content of the repeating unit having an alicyclic hydrocarbon structure substituted with a polar group is preferably 5 to 40 mol%, more preferably 5 to 30 mol%, still more preferably 10 to 25 mol based on all repeating units in the polymer. %.

  Specific examples of the repeating unit having an alicyclic hydrocarbon structure substituted with a polar group are given below, but the present invention is not limited thereto.

  The acid-decomposable resin may have a repeating unit represented by the following general formula (VIII).

In general formula (VIII):
Z ₂ represents —O— or —N (R ₄₁ ) —. R ₄₁ represents a hydrogen atom, a hydroxyl group, an alkyl group, or —OSO ₂ —R ₄₂ . R ₄₂ represents an alkyl group, a cycloalkyl group or a camphor residue. The alkyl group of R ₄₁ and R ₄₂ may be substituted with a halogen atom (preferably a fluorine atom) or the like.

  Specific examples of the repeating unit represented by the general formula (VIII) include the following specific examples, but the present invention is not limited thereto.

  The acid-decomposable resin preferably has a repeating unit having an alkali-soluble group. Examples of the alkali-soluble group include a carboxyl group, a sulfonamide group, a sulfonylimide group, a bisulsulfonylimide group, and an aliphatic alcohol group in which the α-position is substituted with an electron-withdrawing group (preferably represented by the following general formula (F1) Group) and a repeating unit having a carboxyl group is more preferable.

In general formula (F1),
R _{50 to} R ₅₅ each independently represents a hydrogen atom, a fluorine atom or an alkyl group. However, at least one of R _{50 to} R ₅₅ represents a fluorine atom or an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom. All of R _{50 to} R ₅₅ are preferably fluorine atoms.

  By having a repeating unit having an alkali-soluble group, the resolution in contact hole applications is increased.

  The repeating unit having an alkali-soluble group includes a repeating unit in which an alkali-soluble group is directly bonded to the main chain of the resin, such as a repeating unit of acrylic acid or methacrylic acid, or an alkali in the main chain of the resin through a linking group. Either a repeating unit to which a soluble group is bonded, or a polymerization initiator or a chain transfer agent having an alkali-soluble group is introduced at the end of the polymer chain during polymerization, and the linking group is monocyclic or polycyclic. It may have a cyclic hydrocarbon structure. Particularly preferred are repeating units of acrylic acid or methacrylic acid.

  As for content of the repeating unit which has an alkali-soluble group, 1-20 mol% is preferable with respect to all the repeating units in a polymer, More preferably, it is 3-15 mol%, More preferably, it is 5-10 mol%.

  Specific examples of the repeating unit having an alkali-soluble group are shown below, but the present invention is not limited thereto.

  The acid-decomposable resin may further have a repeating unit that has an alicyclic hydrocarbon structure and does not exhibit acid-decomposability. This can reduce the elution of low molecular components from the resist film to the immersion liquid during immersion exposure. Examples of such a repeating unit include a repeating unit composed of 1-adamantyl (meth) acrylate, tricyclodecanyl (meth) acrylate, cyclohexyl (meth) acrylate, and the like.

  In addition to the above repeating structural units, acid-decomposable resins adjust dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and general required properties of resist, such as resolution, heat resistance, and sensitivity. For this purpose, various repeating structural units can be included.

  In addition, any addition-polymerizable unsaturated compound that can be copolymerized with monomers corresponding to the above various repeating structural units may be copolymerized.

  In acid-decomposable resins, the molar ratio of each repeating structural unit is the resist dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and general resist performance required for resolution and heat resistance. It is appropriately set to adjust the property, sensitivity, etc.

  In the acid-decomposable resin, the content of the repeating unit having an acid-decomposable group is preferably 10 to 60 mol%, more preferably 15 to 60 mol%, still more preferably 15 to 55 mol% in all repeating structural units. is there.

In the acid-decomposable resin, the acid-decomposable group is a repeating unit having a partial structure containing an alicyclic hydrocarbon represented by the general formula (pI) to general formula (pV), a general formula (II-AB). It can contain in at least 1 sort (s) of repeating unit among the repeating unit represented by these, and the repeating unit of a copolymerization component.
One type of repeating unit having an acid-decomposable group may be used, but it is preferable to use two or more types of repeating units having an acid-decomposable group having different acid leaving groups. Thereby, the balance between the resolution and the exposure latitude is improved.

In the acid-decomposable resin, the content of the repeating unit having an acid-decomposable group having an alicyclic hydrocarbon structure represented by the general formula (pA) is preferably from 10 to 60 mol%, more preferably from all repeating structural units. Is 15 to 55 mol%, more preferably 20 to 50 mol%.

  In the acid-decomposable resin, the content of the repeating unit having a partial structure containing the alicyclic hydrocarbon represented by the general formulas (pI) to (pV) is preferably 20 to 70 mol% in all repeating structural units, More preferably, it is 20-50 mol%, More preferably, it is 25-40 mol%.

  In the acid-decomposable resin, the content of the repeating unit represented by the general formula (II-AB) is preferably 10 to 60 mol%, more preferably 15 to 55 mol%, still more preferably 20 in all repeating structural units. ˜50 mol%.

  When the composition of the present invention is for ArF exposure, the resin preferably has no aromatic group from the viewpoint of transparency to ArF light.

  The acid-decomposable resin is preferably one in which all of the repeating units are composed of (meth) acrylate repeating units. In this case, all of the repeating units may be methacrylate repeating units, all of the repeating units may be acrylate repeating units, and all of the repeating units may be any of a mixture of methacrylate repeating units / acrylate repeating units. It is preferable that the system repeating unit is 50 mol% or less of all repeating units.

  More preferably, the acid-decomposable resin has a repeating unit of 20 to 50 mol% having a partial structure containing an alicyclic hydrocarbon represented by general formulas (pI) to (pV), and a repeating unit of 20 to 50 having a lactone structure. It is a copolymer having 5 to 30 mol% of a repeating unit having an alicyclic hydrocarbon structure substituted with a polar group, or a copolymer containing 0 to 20 mol% of another repeating unit.

Particularly preferable resins include 20 to 50 mol% of repeating units having an acid-decomposable group represented by the following general formulas (ARA-1) to (ARA-5), and general formulas (ARL-1) to (ARL-6). The repeating unit 5 having an alicyclic hydrocarbon structure substituted with a polar group represented by general formulas (ARH-1) to (ARH-3) 20 to 50 mol% having a lactone group represented by formula (ARH-1) A resin having ˜30 mol%, or a carboxyl group, a repeating unit having a structure represented by the general formula (F1) or an alicyclic hydrocarbon structure, and a repeating unit not showing acid decomposability It is a resin containing 20 mol%.
In the formula, Rxy ₁ represents a hydrogen atom or a methyl group, and Rxa ₁ and Rxb ₁ each independently represents a methyl group or an ethyl group.

In the resist composition of the present invention, the compounding amount of the acid-decomposable resin in the entire composition is preferably 60 to 99% by mass, more preferably 80 to 98% by mass in the total solid content.
In the present invention, the resins may be used alone or in combination.

Resist Composition The resist composition of the present invention contains the above-described acid-decomposable resin and a compound that generates an acid upon irradiation with actinic rays or radiation.

Compound that generates acid upon irradiation with actinic ray or radiation The resist composition of the present invention contains a compound that generates acid upon irradiation with actinic ray or radiation (also referred to as “acid generator”).
Examples of such an acid generator include a photoinitiator for photocationic polymerization, a photoinitiator for photoradical polymerization, a photodecolorant for dyes, a photochromic agent, or an actinic ray or radiation used for a microresist. A known compound that generates an acid by irradiation and a mixture thereof can be appropriately selected and used.

  Examples include diazonium salts, phosphonium salts, sulfonium salts, iodonium salts, imide sulfonates, oxime sulfonates, diazodisulfones, disulfones, o-nitrobenzyl sulfonates, and the like.

Further, a group that generates an acid upon irradiation with these actinic rays or radiation, or a compound in which a compound is introduced into the main chain or side chain of the polymer, for example, US Pat. No. 3,849,137, German Patent No. 3914407. JP, 63-26653, JP, 55-164824, JP, 62-69263, JP, 63-146038, JP, 63-163452.
, JP-A-62-153853, JP-A-63-146029, and the like can be used.

  Furthermore, compounds capable of generating an acid by light described in US Pat. No. 3,779,778, European Patent 126,712 and the like can also be used.

  Among the compounds that generate an acid upon irradiation with actinic rays or radiation, compounds represented by the following general formulas (ZI), (ZII), and (ZIII) can be exemplified.

In general formula (ZI):
R ₂₀₁ , R ₂₀₂ and R ₂₀₃ each independently represents an organic group.
X ⁻ represents a non-nucleophilic anion, preferably sulfonate anion, carboxylate anion, bis (alkylsulfonyl) amide anion, tris (alkylsulfonyl) methide anion, BF ₄ ⁻ , PF ₆ ⁻ , SbF ₆ ^{− and the} like. An organic anion having a carbon atom is preferable.

  Preferred organic anions include organic anions represented by the following general formulas (AN1) to (AN4).

In general formulas (AN1) to (AN2),
Rc ₁ represents an organic group.
Examples of the organic group for Rc ₁ include those having 1 to 30 carbon atoms, and preferably an alkyl group, a cycloalkyl group, an aryl group, or a plurality thereof, which may be substituted, is a single bond, —O—. , —CO ₂ —, —S—, —SO ₃ —, —SO ₂ N (Rd ₁ ) — and the like. Rd ₁ represents a hydrogen atom or an alkyl group, and may form a ring structure with a bonded alkyl group, cycloalkyl group, or aryl group.
The organic group of rc _1, more preferably substituted with at least 1-position fluorine atom or an alkyl group substituted with a fluoroalkyl group, a cycloalkyl group substituted with a fluorine atom or a fluoroalkyl group, a fluorine atom or a fluoroalkyl group Phenyl group. By having a fluorine atom or a fluoroalkyl group, the acidity of the acid generated by light irradiation is increased and the sensitivity is improved. When Rc ₁ has 5 or more carbon atoms, it is preferable that at least one carbon atom has a hydrogen atom, not all hydrogen atoms are substituted with fluorine atoms, and the number of hydrogen atoms is fluorine. More preferably than atoms. By not having a perfluoroalkyl group having 5 or more carbon atoms, ecotoxicity is reduced.

As a particularly preferred embodiment of Rc ₁ , groups represented by the following general formula can be exemplified.

In the above general formula,
Rc ₆ is substituted with a perfluoroalkylene group having 4 or less carbon atoms, more preferably 2 to 4, more preferably 2 to 3, or 1 to 4 fluorine atoms and / or 1 to 3 fluoroalkyl groups. Represents a substituted phenylene group.
Ax represents a single bond or a divalent linking group (preferably —O—, —CO ₂ —, —S—, —SO ₃ —, —SO ₂ N (Rd ₁ ) —). Rd ₁ represents a hydrogen atom or an alkyl group, and may combine with Rc ₇ to form a ring structure.
Rc ₇ represents a hydrogen atom, a fluorine atom, a linear or branched alkyl group, a monocyclic or polycyclic cycloalkyl group or an aryl group. The alkyl group, cycloalkyl group and aryl group may be substituted, but preferably have no fluorine atom as a substituent.

In the general formulas (AN3) to (AN4),
Rc ₃ , Rc ₄ and Rc ₅ each independently represents an organic group.
Preferred examples of the organic group for Rc ₃ , Rc ₄ and Rc ₅ include the same organic groups as those for Rc ₁ .
Rc ₃ and Rc ₄ may combine to form a ring. Examples of the group formed by combining Rc ₃ and Rc ₄ include an alkylene group, a cycloalkylene group, and an arylene group. Preferably, it is a C2-C4 perfluoroalkylene group. By combining Rc ₃ and Rc ₄ to form a ring, the acidity of the acid generated by light irradiation is increased, and the sensitivity is improved, which is preferable.

In the general formula (ZI),
The carbon number of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ is generally 1-30, preferably 1-20.
Two of R _{201 to} R ₂₀₃ may be bonded to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond, or a carbonyl group. The two of the group formed by bonding of the R ₂₀₁ to R _203, there can be mentioned an alkylene group (e.g., butylene, pentylene).
Specific examples of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ include corresponding groups in the compounds (ZI-1), (ZI-2) and (ZI-3) described later.

In addition, the compound which has two or more structures represented by general formula (ZI) may be sufficient. For example, the general formula at least one of R ₂₀₁ to R ₂₀₃ of a compound represented by (ZI) is, at least one bond with structure of R ₂₀₁ to R ₂₀₃ of another compound represented by formula (ZI) It may be a compound.

As more preferred (ZI) components, compounds (ZI-1) and (ZI-2) described below
And (ZI-3).

The compound (ZI-1) is at least one of the aryl groups R ₂₀₁ to R ₂₀₃ in formula (ZI), arylsulfonium compound, i.e., a compound having arylsulfonium as a cation.
Arylsulfonium compound, all of R ₂₀₁ to R ₂₀₃ may be aryl groups, in some aryl groups R ₂₀₁ to R _203, the remainder is an alkyl group or a cycloalkyl group.
Examples of the arylsulfonium compound include triarylsulfonium compounds, diarylalkylsulfonium compounds, aryldialkylsulfonium compounds, diarylcycloalkylsulfonium compounds, aryldicycloalkylsulfonium compounds, and the like.
The aryl group of the arylsulfonium compound is preferably an aryl group such as a phenyl group or a naphthyl group, or a heteroaryl group such as an indole residue or a pyrrole residue, and more preferably a phenyl group or an indole residue. When the arylsulfonium compound has two or more aryl groups, the two or more aryl groups may be the same or different.
The alkyl group that the arylsulfonium compound has as necessary is preferably a linear or branched alkyl group having 1 to 15 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, sec- Examples thereof include a butyl group and a t-butyl group.
The cycloalkyl group that the arylsulfonium compound has as necessary is preferably a cycloalkyl group having 3 to 15 carbon atoms, and examples thereof include a cyclopropyl group, a cyclobutyl group, and a cyclohexyl group.
Aryl group, alkyl group of R ₂₀₁ to R _203, cycloalkyl group, an alkyl group (for example, 1 to 15 carbon atoms), a cycloalkyl group (for example, 3 to 15 carbon atoms), an aryl group (for example, 6 to 14 carbon atoms) , An alkoxy group (for example, having 1 to 15 carbon atoms), a halogen atom, a hydroxyl group, a phenylthio group and the like may be substituted. Preferred substituents are linear or branched alkyl groups having 1 to 12 carbon atoms, cycloalkyl groups having 3 to 12 carbon atoms, and linear, branched or cyclic alkoxy groups having 1 to 12 carbon atoms, and particularly preferable. Is an alkyl group having 1 to 4 carbon atoms and an alkoxy group having 1 to 4 carbon atoms. The substituent may be substituted with any one of the three R _{201 to} R ₂₀₃ , or may be substituted with all three. When R _{201 to} R ₂₀₃ are an aryl group, the substituent is preferably substituted at the p-position of the aryl group.

Next, the compound (ZI-2) will be described.
The compound (ZI-2) is, R ₂₀₁ to R ₂₀₃ in formula (ZI) each independently is a compound when it represents an organic group having no aromatic ring. Here, the aromatic ring includes an aromatic ring having a hetero atom.
The aromatic ring-free organic group as R ₂₀₁ to R ₂₀₃ generally has 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms.
R _{201 to} R ₂₀₃ are each independently preferably an alkyl group, a cycloalkyl group, an allyl group, or a vinyl group, more preferably a linear, branched, cyclic 2-oxoalkyl group, an alkoxycarbonylmethyl group, Particularly preferred is a linear or branched 2-oxoalkyl group.

The alkyl group as R ₂₀₁ to R ₂₀₃ is preferably include a linear or branched alkyl group having 1 to 10 carbon atoms (e.g., methyl group, ethyl group, propyl group, butyl group, pentyl group) . The alkyl group as R ₂₀₁ to R ₂₀₃ may be linear, branched 2-oxoalkyl group, more preferably an alkoxymethyl group.
The cycloalkyl group as R ₂₀₁ to R ₂₀₃ is preferably, and a cycloalkyl group having 3 to 10 carbon atoms (e.g., cyclopentyl, cyclohexyl, norbornyl). The cycloalkyl group as R ₂₀₁ to R ₂₀₃ is more preferably a cyclic 2-oxoalkyl group.
Linear as R ₂₀₁ to R _203, branched or cyclic 2-oxoalkyl group may preferably be a group having a 2-position> C = O in the above-described alkyl or cycloalkyl group.
The alkoxy group in the alkoxycarbonylmethyl group as R ₂₀₁ to R _203, preferably may be mentioned alkoxy groups having 1 to 5 carbon atoms (a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentoxy group).
R _{201 to} R ₂₀₃ may be further substituted with a halogen atom, an alkoxy group (eg, having 1 to 5 carbon atoms), a hydroxyl group, a cyano group, a nitro group, or the like.

  The compound (ZI-3) is a compound represented by the following general formula (ZI-3), and is a compound having a phenacylsulfonium salt structure.

In general formula (ZI-3),
R _{1c to} R _5c each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group or a halogen atom.
R _6c and R _7c each independently represents a hydrogen atom, an alkyl group or a cycloalkyl group.
Rx and Ry each independently represents an alkyl group, a cycloalkyl group, an allyl group or a vinyl group.
Any two or more of R _1c to R _7c, and R _x and R _y may be bonded to each other to form a ring structure, the ring structure may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond May be included. Examples of the group formed by combining any two or more of R _{1c to} R _7c and R _x and R _y include a butylene group and a pentylene group.
X ⁻ represents a non-nucleophilic anion, and examples thereof include the same non-nucleophilic anion as X ^{− in} the general formula (ZI).

The alkyl group as R _{1c to} R _7c is, for example, a linear or branched alkyl group having 1 to 20 carbon atoms, preferably a linear or branched alkyl group having 1 to 12 carbon atoms (for example, a methyl group). , Ethyl group, linear or branched propyl group, linear or branched butyl group, linear or branched pentyl group).
Preferable examples of the cycloalkyl group as R _{1c to} R _7c include a cycloalkyl group having 3 to 8 carbon atoms (for example, a cyclopentyl group and a cyclohexyl group).
The alkoxy group as R _{1c to} R _{5c may} be linear, branched or cyclic, for example, an alkoxy group having 1 to 10 carbon atoms, preferably a linear or branched alkoxy group having 1 to 5 carbon atoms. (For example, methoxy group, ethoxy group, linear or branched propoxy group, linear or branched butoxy group, linear or branched pentoxy group), C3-C8 cyclic alkoxy group (for example, cyclopentyloxy group, cyclohexyloxy group) ).
R _{1c to} R _7c may be further substituted with a halogen atom, an alkoxy group (for example, having 1 to 5 carbon atoms), a hydroxyl group, a cyano group, or a nitro group.
Preferably any one of R _{1c to} R _5c is a linear or branched alkyl group, a cycloalkyl group, or a linear, branched or cyclic alkoxy group, and more preferably the sum of the carbon number of R _{1c to} R _5c is 2-15. Thereby, solvent solubility improves more and generation | occurrence | production of a particle is suppressed at the time of a preservation | save.

_Examples of the alkyl group as R _x and R _y include the same alkyl groups as R _{1c to} R _7c . The alkyl group as R _x and R _y is more preferably a linear or branched 2-oxoalkyl group or an alkoxymethyl group.
The cycloalkyl group as R _x and R _y may be the same as the cycloalkyl group as R _1c to R _7c. The cycloalkyl group as R _x and R _y is more preferably a cyclic 2-oxoalkyl group.
Examples of the linear or branched alkyl group and the cyclic 2-oxoalkyl group include a group having> C═O at the 2-position of the alkyl group or cycloalkyl group as R _{1c to} R _7c .
Examples of the alkoxy group in the alkoxycarbonylmethyl group include the same alkoxy groups as R _{1c to} R _5c .
R _x and R _y may be further substituted with a halogen atom, an alkoxy group (for example, having 1 to 5 carbon atoms), a hydroxyl group, a cyano group, a nitro group, or the like.
R _x and R _y are preferably an alkyl group having 4 or more carbon atoms, more preferably 6 or more, and still more preferably 8 or more.

In the general formulas (ZII) and (ZIII),
R ₂₀₄ to R ₂₀₇ each independently represents an aryl group, an alkyl group or a cycloalkyl group.
The aryl group of R ₂₀₄ to R _207, a phenyl group, a naphthyl group, more preferably a phenyl group.
The alkyl group as R ₂₀₄ to R ₂₀₇ may preferably be mentioned a linear or branched alkyl group having 1 to 10 carbon atoms (e.g., methyl group, ethyl group, propyl group, butyl group, pentyl group).
The cycloalkyl group as R ₂₀₄ to R ₂₀₇ is preferably, and a cycloalkyl group having 3 to 10 carbon atoms (e.g., cyclopentyl, cyclohexyl, norbornyl).
R ₂₀₄ to R ₂₀₇ may have a substituent. The R ₂₀₄ to R ₂₀₇ are substituents which may have, for example, an alkyl group (for example, 1 to 15 carbon atoms), a cycloalkyl group (for example, 3 to 15 carbon atoms), an aryl group (e.g., 6 carbon atoms 15), alkoxy groups (for example, having 1 to 15 carbon atoms), halogen atoms, hydroxyl groups, phenylthio groups and the like.
X ⁻ represents a non-nucleophilic anion, and examples thereof include the same non-nucleophilic anion as X ^{− in} formula (ZI).

  Among the compounds that decompose upon irradiation with actinic rays or radiation to generate acids, compounds represented by the following general formulas (ZIV), (ZV), and (ZVI) can be further exemplified.

In the general formulas (ZIV) to (ZVI),
Ar ₃ and Ar ₄ each independently represents an aryl group.
R ₂₀₆ represents an alkyl group, a cycloalkyl group or an aryl group.
R ₂₀₇ and R ₂₀₈ each independently represents an alkyl group, a cycloalkyl group, an aryl group, or an electron-withdrawing group. R ₂₀₇ is preferably an aryl group. R ₂₀₈ is preferably an electron-withdrawing group, more preferably a cyano group or a fluoroalkyl group.
A represents an alkylene group, an alkenylene group or an arylene group.

Of the compounds that generate an acid upon irradiation with actinic rays or radiation, more preferred are compounds represented by general formulas (ZI) to (ZIII), and even more preferred are compounds represented by general formula (ZI). And particularly preferred are compounds represented by the general formulas (ZI-1) to (ZI-3).
Furthermore, the compound which generate | occur | produces the acid represented by the following general formula (AC1)-(AC3) by irradiation of actinic light or a radiation is preferable.

In formula (AC1) ~ (AC3), Rc 1, Rc 3 ~Rc 5 are in the general formula (AN1) ~ (AN4), and Rc _1, Rc ₃ ~Rc ₅ synonymous.

As a particularly preferred embodiment of the acid generator, in the compound represented by the general formula (ZI), X ⁻ is an anion selected from the above (AN1), (AN3), and (AN4). .

  Among the compounds that generate an acid upon irradiation with actinic rays or radiation, examples of particularly preferable compounds are listed below, but the present invention is not limited thereto.

An acid generator can be used individually by 1 type or in combination of 2 or more types. When two or more types are used in combination, it is preferable to combine two types of compounds that generate two types of organic acids that differ in the total number of atoms excluding hydrogen atoms by two or more.
The content of the acid generator in the composition is preferably 0.1 to 20% by mass, more preferably 0.5 to 10% by mass, and still more preferably 1 to 7% by mass, based on the total solid content of the resist composition. %.

A dissolution control compound having a molecular weight of 3000 or less, having at least one selected from an alkali-soluble group, a hydrophilic group, and an acid-decomposable group. The resist composition of the present invention is selected from an alkali-soluble group, a hydrophilic group, and an acid-decomposable group. A dissolution controlling compound having a molecular weight of 3000 or less (hereinafter also referred to as “solubility controlling compound”) having at least one may be added.
Examples of the dissolution control compound include a carboxyl group, a sulfonylimide group, a compound having an alkali-soluble group such as a hydroxyl group substituted at the α-position with a fluoroalkyl group, a hydroxyl group, a lactone group, a cyano group, an amide group, a pyrrolidone group, and a sulfonamide group. A compound having a hydrophilic group such as the above and a compound having an acid-decomposable group are preferred. The acid-decomposable group is preferably a group in which a carboxyl group or a hydroxyl group is protected with an acid-eliminable group. In order not to lower the permeability of 220 nm or less as a dissolution control compound, when a compound having no aromatic ring is used or a compound having an aromatic ring is used, the compound having an aromatic ring is added to the solid content of the resist composition. On the other hand, it is preferably used in an addition amount of 20 mass% or less.
Preferred dissolution control compounds include carboxylic acid compounds having an alicyclic hydrocarbon structure such as adamantane (di) carboxylic acid, norbornane carboxylic acid, and cholic acid, or compounds obtained by protecting the carboxylic acid with an acid-eliminable group, such as saccharides. A compound in which a polyol or a hydroxyl group thereof is protected with an acid leaving group is preferred.

  The molecular weight of the dissolution controlling compound is 3000 or less, preferably 300 to 3000, and more preferably 500 to 2500.

  The addition amount of the dissolution control compound is preferably 3 to 40% by mass, more preferably 5 to 20% by mass, based on the solid content of the resist composition.

  Specific examples of the dissolution control compound are shown below, but the present invention is not limited thereto.

Basic Compound The resist composition of the present invention preferably contains a basic compound in order to reduce the change in performance over time from exposure to heating or to control the diffusibility of the acid generated by exposure in the film.

  Examples of basic compounds include nitrogen-containing basic compounds and onium salt compounds. Preferable nitrogen-containing basic compound structures include compounds having partial structures represented by the following general formulas (A) to (E).

In general formula (A),
R ²⁵⁰ , R ²⁵¹ and R ²⁵² are each independently a hydrogen atom, an alkyl group (preferably having 1 to 20 carbon atoms), a cycloalkyl group (preferably having 3 to 20 carbon atoms) or an aryl group (preferably having 6 carbon atoms). ~ 20). R ²⁵⁰ and R ²⁵¹ may combine with each other to form a ring. These may have a substituent, and as the alkyl group and cycloalkyl group having a substituent, an aminoalkyl group (preferably having a carbon number of 1 to 20) or an aminocycloalkyl group (preferably having a carbon number of 3 to 3). 20), a hydroxyalkyl group (preferably having 1 to 20 carbon atoms) or a hydroxycycloalkyl group (preferably having 3 to 20 carbon atoms) is preferable.
These may contain an oxygen atom, a sulfur atom, or a nitrogen atom in the alkyl chain.
In general formula (E),
R ²⁵³ , R ²⁵⁴ , R ²⁵⁵ and R ²⁵⁶ each independently represents an alkyl group (preferably having 1 to 6 carbon atoms) or a cycloalkyl group (preferably having 3 to 6 carbon atoms).

  Preferable compounds include guanidine, aminopyrrolidine, pyrazole, pyrazoline, piperazine, aminomorpholine, aminoalkylmorpholine, and piperidine, and may have a substituent. More preferred compounds include compounds having an imidazole structure, diazabicyclo structure, onium hydroxide structure, onium carboxylate structure, trialkylamine structure, aniline structure or pyridine structure, alkylamine derivatives having a hydroxyl group and / or an ether bond, hydroxyl groups and / or Or the aniline derivative which has an ether bond etc. can be mentioned.

Examples of the compound having an imidazole structure include imidazole, 2,4,5-triphenylimidazole, and benzimidazole. Examples of the compound having a diazabicyclo structure include 1,4-diazabicyclo [2,2,2] octane, 1,5-diazabicyclo [4,3,0] non-5-ene, and 1,8-diazabicyclo [5,4. 0] undec-7-ene and the like. Examples of the compound having an onium hydroxide structure include triarylsulfonium hydroxide, phenacylsulfonium hydroxide, sulfonium hydroxide having a 2-oxoalkyl group, specifically, triphenylsulfonium hydroxide, tris (t-butylphenyl). ) Sulfonium hydroxide, bis (t-butylphenyl) iodonium hydroxide, phenacylthiophenium hydroxide, 2-oxopropylthiophenium hydroxide, and the like. As the compound having an onium carboxylate structure, the anion portion of the compound having an onium hydroxide structure is converted to a carboxylate, and examples thereof include acetate, adamantane-1-carboxylate, and perfluoroalkylcarboxylate. . Examples of the compound having a trialkylamine structure include tri (n-butyl) amine and tri (n-octyl) amine. Examples of aniline compounds include 2,6-diisopropylaniline and N, N-dimethylaniline. Examples of the alkylamine derivative having a hydroxyl group and / or an ether bond include ethanolamine, diethanolamine, triethanolamine, and tris (methoxyethoxyethyl) amine. Examples of aniline derivatives having a hydroxyl group and / or an ether bond include N, N-bis (hydroxyethyl) aniline.

  These basic compounds are used alone or in combination of two or more. The usage-amount of a basic compound is 0.001-10 mass% normally based on solid content of a resist composition, Preferably it is 0.01-5 mass%. In order to obtain a sufficient addition effect, 0.001% by mass or more is preferable, and 10% by mass or less is preferable in terms of sensitivity and developability of the non-exposed area.

Fluorine and / or silicon surfactant The resist composition of the present invention further comprises a fluorine and / or silicon surfactant (fluorine surfactant and silicon surfactant, both fluorine atom and silicon atom). It is preferable to contain any one or two or more surfactants.

  When the resist composition of the present invention contains fluorine and / or a silicon-based surfactant, when using an exposure light source of 250 nm or less, particularly 220 nm or less, good sensitivity and resolution, and less adhesion and development defects. A pattern can be given.

  Examples of these fluorine and / or silicon surfactants are, for example, JP-A-62-36663, JP-A-61-226746, JP-A-61-226745, JP-A-62-170950. JP-A-63-34540, JP-A-7-230165, JP-A-8-62834, JP-A-9-54432, JP-A-9-5988, JP-A-2002-277862, U.S. Pat. The following commercially available surfactants can also be used as they are.

  Examples of commercially available surfactants that can be used include F-top EF301 and EF303 (manufactured by Shin-Akita Kasei Co., Ltd.), Florard FC430 and 431 (manufactured by Sumitomo 3M Co., Ltd.), MegaFuck F171, F173, F176, F189, R08 (Dainippon Ink Chemical Co., Ltd.), Surflon S-382, SC101, 102, 103, 104, 105, 106 (Asahi Glass Co., Ltd.), Troisol S-366 (Troy Chemical Co., Ltd.), etc. Fluorine-based surfactant or silicon-based surfactant. Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) can also be used as a silicon-based surfactant.

  In addition to the known surfactants described above, surfactants are derived from fluoroaliphatic compounds produced by the telomerization method (also referred to as the telomer method) or the oligomerization method (also referred to as the oligomer method). A surfactant using a polymer having a fluoroaliphatic group can be used. The fluoroaliphatic compound can be synthesized by the method described in JP-A-2002-90991.

As the polymer having a fluoroaliphatic group, a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate and / or (poly (oxyalkylene)) methacrylate is preferable and distributed irregularly. It may be block copolymerized. In addition, poly (oxyalkylene) groups include poly (oxyethylene) groups, poly (oxyethylene) groups,
Oxypropylene) group, poly (oxybutylene) group, etc., and the same such as poly (block connection body of oxyethylene, oxypropylene and oxyethylene) and poly (block connection body of oxyethylene and oxypropylene) It may be a unit having different chain length alkylenes in the chain length. Furthermore, the copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate (or methacrylate) is not only a binary copolymer but also a monomer having two or more different fluoroaliphatic groups. Alternatively, it may be a ternary or higher copolymer obtained by simultaneously copolymerizing two or more different (poly (oxyalkylene)) acrylates (or methacrylates).

Examples of commercially available surfactants include Megafac F178, F-470, F-473, F-475, F-476, and F-472 (Dainippon Ink Chemical Co., Ltd.). Further, a copolymer of an acrylate (or methacrylate) having a C ₆ F ₁₃ group and (poly (oxyalkylene)) acrylate (or methacrylate), an acrylate (or methacrylate) having a C ₆ F ₁₃ group and (poly (oxy) (Ethylene)) acrylate (or methacrylate) and (poly (oxypropylene)) acrylate (or methacrylate) copolymer, acrylate (or methacrylate) and (poly (oxyalkylene)) acrylate having C ₈ F ₁₇ groups (or Copolymer of acrylate (or methacrylate), (poly (oxyethylene)) acrylate (or methacrylate), and (poly (oxypropylene)) acrylate (or methacrylate) having a C ₈ F ₁₇ group Coalesce, etc. Can.

  The amount of fluorine and / or silicon-based surfactant used is preferably 0.0001 to 2% by mass, more preferably 0.001 to 1% by mass, based on the total amount of the resist composition (excluding the solvent). .

Surface Hydrophobic Resin When a resist film made of the resist composition of the present invention is exposed through immersion water, a surface hydrophobizing resin can be further added as necessary. Thereby, the receding contact angle on the resist film surface can be improved and the immersion water followability can be improved. As the surface hydrophobizing resin, any resin can be used as long as the receding contact angle of the surface can be improved by addition, but a resin having at least one of fluorine atom and silicon atom is preferable. The addition amount can be adjusted as appropriate so that the receding contact angle of the resist film is 60 ° to 80 °, but preferably 0.1 to 5% by mass.

Organic Solvent The resist composition of the present invention is used by dissolving each component in a predetermined organic solvent.
Examples of the organic solvent that can be used include ethylene dichloride, cyclohexanone, cyclopentanone, 2-heptanone, γ-butyrolactone, methyl ethyl ketone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 2-methoxyethyl acetate, ethylene glycol monoethyl. Ether acetate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, toluene, ethyl acetate, methyl lactate, ethyl lactate, methyl methoxypropionate, ethyl ethoxypropionate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, N, N -Dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, tetrahydrofuran, etc.

In the present invention, the organic solvent may be used alone or in combination, but it is preferable to use a mixed solvent containing two or more solvents having different functional groups. As a result, the solubility of the material is increased, and not only the generation of particles over time can be suppressed, but also a good pattern profile can be obtained. The mixed solvent containing two or more kinds of solvents having different functional groups is at least selected from a solvent having a hydroxyl group, a solvent having an ester structure, a solvent having a ketone structure, a solvent having a lactone structure, and a solvent having a carbonate structure. A mixed solvent containing two kinds is preferred.

As the mixed solvent having different functional groups, the following mixed solvents (S1) to (S6) are preferable.
(S1) a mixed solvent containing at least a solvent having a hydroxyl group and a solvent having no hydroxyl group,
(S2) a mixed solvent containing at least a solvent having an ester structure and a solvent having a ketone structure;
(S3) a mixed solvent containing at least a solvent having an ester structure and a solvent having a lactone structure;
(S4) a mixed solvent containing at least a solvent having an ester structure, a solvent having a lactone structure, and a solvent having a hydroxyl group,
(S5) Mixed solvent containing at least a solvent having an ester structure, a solvent having a carbonate structure, and a solvent having a hydroxyl group; and (S6) a solvent having an ester structure, a solvent having a ketone structure, and a lactone structure. A mixed solvent containing at least a solvent.
As a result, the generation of particles during storage of the resist solution can be reduced, and the generation of defects during application can be suppressed.

  Examples of the solvent having a hydroxyl group include ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, ethyl lactate, and the like. Propylene glycol monomethyl ether and ethyl lactate are preferred.

  Examples of the solvent having no hydroxyl group include propylene glycol monomethyl ether acetate, ethyl ethoxypropionate, 2-heptanone, γ-butyrolactone, cyclohexanone, butyl acetate, N-methylpyrrolidone, N, N-dimethylacetamide, dimethyl sulfoxide. Among these, propylene glycol monomethyl ether acetate, ethyl ethoxypropionate, 2-heptanone, γ-butyrolactone, cyclohexanone, and butyl acetate are preferable, propylene glycol monomethyl ether acetate, ethyl ethoxypropionate 2-heptanone and cyclohexanone are more preferred.

Examples of the solvent having a ketone structure include cyclohexanone and 2-heptanone, and 2-heptanone is preferable.
Examples of the solvent having an ester structure include propylene glycol monomethyl ether acetate, ethyl ethoxypropionate, and butyl acetate, and propylene glycol monomethyl ether acetate is preferable.
Examples of the solvent having a lactone structure include γ-butyrolactone.
Examples of the solvent having a carbonate structure include propylene carbonate and ethylene carbonate, and propylene carbonate is preferred.

The mixing ratio (mass) of the solvent having a hydroxyl group and the solvent not having a hydroxyl group in (S1) is usually 1/99 to 99/1, preferably 10/90 to 90/10, more preferably 20/80. ~ 60/40. A mixed solvent containing 50% by mass or more of a solvent having no hydroxyl group is preferable in terms of coating uniformity.
Mixing ratio of solvent having ester structure and solvent having ketone structure in (S2) (
(Mass) is usually 1/99 to 99/1, preferably 10/90 to 90/10, more preferably 40/60 to 80/20. A mixed solvent containing 50% by mass or more of a solvent having an ester structure is preferable in terms of coating uniformity.
The mixing ratio (mass) of the solvent having an ester structure and the solvent having a lactone structure in (S3) is usually 70/30 to 99/1, preferably 80/20 to 99/1, more preferably 90/10. ~ 99/1. A mixed solvent containing 70% by mass or more of a solvent having an ester structure is preferable in terms of stability over time.
When mixing the solvent having an ester structure in (S4), the solvent having a lactone structure, and the solvent containing a hydroxyl group, 30 to 80% by mass of the solvent having an ester structure and 1 to 20 solvents having a lactone structure are used. It is preferable to contain 10 to 60% by mass of a solvent having a mass% and a hydroxyl group.
When mixing the solvent having an ester structure, the solvent having a carbonate structure, and the solvent having a hydroxyl group in (S5), 30 to 80% by mass of the solvent having an ester structure and 1 to 20 masses of the solvent having a carbonate structure. % And a solvent having a hydroxyl group is preferably contained in an amount of 10 to 60% by mass.
In mixing the solvent having an ester structure, the solvent having a ketone structure, and the solvent having a lactone structure in (S6), the solvent having an ester structure is 30 to 80% by mass, and the solvent having a ketone structure is 10 to 60%. It is preferable to contain 1% by mass to 20% by mass of a solvent containing a lactone structure.

Other Additives The resist composition of the present invention may further contain a dye, a plasticizer, a surfactant other than fluorine and / or a silicon-based surfactant, a photosensitizer, and the like as necessary.

  In the present invention, other surfactants than fluorine and / or silicon surfactants can be added. Specifically, nonionic interfaces such as polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, polyoxyethylene / polyoxypropylene block copolymers, sorbitan aliphatic esters, polyoxyethylene sorbitan aliphatic esters, etc. Mention may be made of activators.

  These surfactants may be added alone or in some combination.

Pattern Forming Method The resist composition of the present invention is used by dissolving each component in a predetermined organic solvent, preferably the mixed solvent, filtering the solution, and then applying the solution on a predetermined support as follows. The filter used for filter filtration is preferably made of polytetrafluoroethylene, polyethylene, or nylon of 0.1 microns or less, more preferably 0.05 microns or less, and still more preferably 0.03 microns or less.

  For example, the resist composition may be applied to an arbitrary thickness (usually 50 to 500 nm) by a suitable application method such as a spinner or coater on a substrate (eg, silicon / silicon dioxide coating) used for manufacturing a precision integrated circuit device. Apply. After application, the resist film is formed by drying by spinning or baking. The bake temperature can be set as appropriate, but is usually 60 to 150 ° C, and preferably 90 to 130 ° C.

Next, exposure is performed through a mask or the like for pattern formation. Although an exposure amount can be set suitably, it is 1-100 mJ / cm < ² > normally. After exposure, preferably, spinning or / and baking is performed, development and rinsing are performed to obtain a pattern.

  Exposure (immersion exposure) may be performed by filling a liquid (immersion medium) having a higher refractive index than air between the resist film and the lens during irradiation with actinic rays or radiation. Thereby, resolution can be improved. As the immersion medium to be used, any liquid can be used as long as it has a higher refractive index than air, but pure water is preferred. Further, an overcoat layer may be further provided on the resist film so that the immersion medium and the resist film do not come into direct contact with each other during the immersion exposure. Thereby, the elution of the composition from the photosensitive film to the immersion medium is suppressed, and development defects are reduced.

Examples of the actinic ray or radiation include infrared light, visible light, ultraviolet light, far ultraviolet light, X-ray, electron beam, etc., but preferably far ultraviolet light having a wavelength of 250 nm or less, more preferably 220 nm or less. Specifically, KrF excimer laser (248 nm), ArF excimer laser (193 nm), F ₂ excimer laser (157 nm), EUV (13 nm), X-ray, electron beam, etc. ArF excimer laser, F ₂ excimer laser , EUV (13 nm) and electron beam are preferable.

Before forming the resist film, an antireflection film may be coated on the substrate in advance.
As the antireflection film, any of an inorganic film type such as titanium, titanium dioxide, titanium nitride, chromium oxide, carbon, and amorphous silicon, and an organic film type made of a light absorber and a polymer material can be used. In addition, as the organic antireflection film, commercially available organic antireflection films such as DUV30 series, DUV-40 series manufactured by Brewer Science, AR-2, AR-3, AR-5 manufactured by Shipley, etc. may be used. it can.

In the development step, an alkaline developer is used as follows. As an alkaline developer of the resist composition, inorganic hydroxides such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia, primary amines such as ethylamine and n-propylamine, Secondary amines such as diethylamine and di-n-butylamine, tertiary amines such as triethylamine and methyldiethylamine, alcohol amines such as dimethylethanolamine and triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide and the like Alkaline aqueous solutions such as quaternary ammonium salts, cyclic amines such as pyrrole and pihelidine can be used.
Furthermore, alcohols and surfactants can be added in appropriate amounts to the alkaline developer.
The alkali concentration of the alkali developer is usually from 0.1 to 20% by mass.
The pH of the alkaline developer is usually from 10.0 to 14.0.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to this.

Example 1
Under a nitrogen stream, 4.2 g of sulfolane and 4.2 g of propylene glycol monomethyl ether acetate were placed in a three-necked flask and heated to 80 ° C. To this, 7.4 g of 2-cyano-2,6-norbornylcarbolactone-5-methacrylate, 1.5 g of 3,5-dihydroxyadamantyl-1-methacrylate, 1.6 g of 2-adamantyl-2-propyl methacrylate, 2 -(4-Methylcyclohexyl) -2-propyl methacrylate 4.54 g, polymerization initiator V-60 (manufactured by Wako Pure Chemical Industries, Ltd.) 8 mol% with respect to the monomer were dissolved in 27.1 g sulfolane and 27.1 g propylene glycol methyl ether acetate. The solution was added dropwise over 6 hours. After completion of dropping, the reaction was further carried out at 80 ° C. for 2 hours. The reaction solution was allowed to cool and then added dropwise over 20 minutes to a mixed solution of 900 m of methanol / 100 ml of water, and the precipitated powder was collected by filtration and dried to obtain 14.1 g of Resin (RA-1). The weight average molecular weight of the obtained resin (RA-1) is 8500 in terms of standard polystyrene, and the dispersity (Mw / Mn) is 1.8.
0.

Example 2
Under a nitrogen stream, 7.5 g of sulfolane was placed in a three-necked flask and heated to 80 ° C. To this, 7.1 g of 2,6-norbornylcarbolactone-5-methacrylate, 3.7 g of 3-hydroxyadamantyl-1-methacrylate, 8.0 g of 2-methyl-2-adamantyl methacrylate, polymerization initiator V-60 A solution prepared by dissolving 8 mol% of (manufactured by Wako Pure Chemical Industries, Ltd.) in 68 g of sulfolane with respect to the monomer was dropped over 6 hours. After completion of dropping, the reaction was further carried out at 80 ° C. for 2 hours. The reaction solution was allowed to cool and then added dropwise over 20 minutes to a mixed solution of methanol 900 m / water 100 ml. The precipitated powder was collected by filtration and dried, yielding 14.9 g of resin (RA-2). The weight average molecular weight of the obtained resin (RA-2) was 8900 in terms of standard polystyrene, and the dispersity (Mw / Mn) was 1.61.

Example 3
Under a nitrogen stream, 2.1 g of isopropylmethylsulfone and 5.0 g of sulfolane were placed in a three-necked flask and heated to 80 ° C. To this, 7.1 g of 2,6-norbornylcarbolactone-5-methacrylate, 4.4 g of 3,5-dihydroxyadamantyl-1-methacrylate, 6.0 g of 2-adamantyl-2-propyl methacrylate, and 0.005 g of methacrylic acid. 69 g of a polymerization initiator V-60 (manufactured by Wako Pure Chemical Industries, Ltd.) in an amount of 8 mol% dissolved in 4.0 g of isopropylmethylsulfone and 60 g of sulfolane with respect to the monomer was added dropwise over 6 hours. After completion of dropping, the reaction was further carried out at 80 ° C. for 2 hours. The reaction solution was allowed to cool and then added dropwise over 20 minutes to a mixed solution of methanol 900 m / water 100 ml. The precipitated powder was collected by filtration and dried, yielding 15.2 g of resin (RA-3). The weight average molecular weight of the obtained resin (RA-3) was 10100 in terms of standard polystyrene, and the dispersity (Mw / Mn) was 1.80.

Example 4
Under a nitrogen stream, 4.0 g of sulfolane and 4.0 g of methyl ethyl ketone were placed in a three-necked flask and heated to 80 ° C. To this, 9.9 g of 2-cyano-2,6-norbornylcarbolactone-5-methacrylate, 4.0 g of 3,5-dihydroxyadamantyl-1-methacrylate, 6.0 g of 2-adamantyl-2-propyl methacrylate, A solution prepared by dissolving 12 mol% of a polymerization initiator V-60 (manufactured by Wako Pure Chemical Industries, Ltd.) in 36.0 g of sulfolane and 36.0 g of methyl ethyl ketone was added dropwise over 6 hours. After completion of dropping, the reaction was further carried out at 80 ° C. for 2 hours. The reaction solution was allowed to cool and then added dropwise over 20 minutes to a mixed solution of methanol 900 m / water 100 ml. The precipitated powder was collected by filtration and dried to obtain 15.1 g of Resin (RA-4). The weight average molecular weight of the obtained resin (RA-4) was 5800 in terms of standard polystyrene, and the dispersity (Mw / Mn) was 1.79.

  In Examples 1 to 4, various monomers were easily dissolved in the solvent.

  Hereinafter, the structures of the resins (RA-1) to (RA-4) are shown.

Comparative Example 1
When resin was manufactured on the conditions similar to Example 1 except having changed the solvent into 1, 4- dioxane, 11.5g of resin (RA-1 ') was obtained. The weight average molecular weight of the resin (RA-1 ′) was 7500 in terms of standard polystyrene, and the dispersity (Mw / Mn) was 1.65.

Comparative Example 2
When resin was manufactured on the conditions similar to Example 2 except having changed the solvent into 1, 4- dioxane, 13.8g of resin (RA-2 ') was obtained. The weight average molecular weight of the resin (RA-2 ′) was 8100 in terms of standard polystyrene, and the dispersity (Mw / Mn) was 1.89.

Comparative Example 3
Except for changing the solvent to propylene glycol monomethyl ether acetate, an attempt was made to produce a resin under the same conditions as in Example 3. However, the monomer was not sufficiently dissolved at room temperature, and the resin could not be produced.

Comparative Example 4
Except for changing the solvent to xylene (a mixture of o-, m-, and p-), an attempt was made to produce a resin under the same conditions as in Example 4. However, the monomer did not dissolve sufficiently at room temperature, and the resin was produced. I couldn't.

Examples 5-8 and Comparative Examples 5-6
<Resist preparation>
The components shown in Table 1 below were dissolved in a solvent to prepare a solution having a solid content concentration of 8% by mass, and this was filtered through a 0.03 micron polyethylene filter to prepare a positive resist solution. The prepared positive resist solution was evaluated by the following method, and the results are also shown in Table 1.

<Resist evaluation>
An anti-reflective coating DUV-42 manufactured by Brewer Science Co., Ltd. was uniformly applied to 600 angstroms on a silicon substrate subjected to hexamethyldisilazane treatment with a spin coater, dried on a hot plate at 100 ° C. for 90 seconds, and then at 190 ° C. Heat drying was performed for 240 seconds. Thereafter, each positive resist solution was applied by a spin coater and dried at 120 ° C. for 60 seconds to form a 160 nm resist film.
The resist film was exposed with an ArF excimer laser stepper (NA = 0.75, dipole manufactured by ASML) through a mask, and heated on a hot plate at 120 ° C. for 60 seconds immediately after the exposure. Further, the resist film was developed with an aqueous 2.38 mass% tetramethylammonium hydroxide solution at 23 ° C. for 60 seconds, rinsed with pure water for 30 seconds, and then dried to obtain a line pattern.
Line edge roughness evaluation method:
Using a length-measuring scanning electron microscope (SEM), observe a 80 nm line-and-space 1: 1 pattern and measure the distance from the reference line where the edge of the line pattern should be 5 μm long. 20 points were measured by SEM (Hitachi, Ltd. S-8840), the standard deviation was obtained, and 3σ was calculated. A smaller value indicates better performance.

Hereinafter, abbreviations in the table will be described.
[Basic compounds]
DIA: 2,6-diisopropylaniline TEA: triethanolamine PEA: N-phenyldiethanolamine [Surfactant]
W-1: MegaFuck F176 (Dainippon Ink Chemical Co., Ltd.) (Fluorine)
W-2: Megafuck R08 (Dainippon Ink Chemical Co., Ltd.) (fluorine and silicon)
W-3: Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) (silicon-based)
〔solvent〕
S1: Propylene glycol methyl ether acetate S2: Cyclohexanone S3: γ-butyrolactone S4: Propylene glycol methyl ether S5: Ethyl lactate

  From Table 1, it can be seen that a resist composition containing a resin produced by using the specific solvent of the present invention can form a resist pattern having a small line edge roughness.

Claims (8)

By polymerizing a monomer in the presence of a compound represented by the following general formula (I) as a solvent, a resin that is decomposed by the action of an acid and has increased solubility in an alkaline developer is produced. Manufacturing method of resin.

In general formula (I),
R ₁ and R ₂ each independently represents an alkyl group, an alkenyl group, a cycloalkyl group, a cycloalkenyl group, an aryl group, a heterocyclic group, or an amino group. R ₁ and R ₂ may be linked to form a ring. The method for producing a resin according to claim _1, wherein R ₁ and R ₂ in the general formula (I) are alkyl groups.   The resin production method according to claim 1, wherein the resin has a repeating unit having an acid-decomposable group having an alicyclic hydrocarbon structure.   The method for producing a resin according to claim 1, wherein the resin has a repeating unit having a lactone structure.   The resin production method according to claim 1, wherein the resin has a repeating unit having an alicyclic hydrocarbon structure substituted with a polar group.   A resin produced by the method according to claim 1 and decomposed by the action of an acid to increase the solubility in an alkaline developer.   A resist composition comprising: a resin that decomposes by the action of an acid according to claim 6 and that increases the solubility in an alkaline developer; and a compound that generates an acid upon irradiation with actinic rays or radiation. .   A pattern forming method comprising: forming a resist film using the resist composition according to claim 7; and exposing and developing the resist film.