JPH11143079A - Radiation-sensitive resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chemically amplified positive resist which is sensitive to various types of radiation, has excellent sensitivity and resolution, is less affected by standing waves, has excellent pattern shape, and has high heat resistance. As a radiation-sensitive resin composition. SOLUTION: The radiation-sensitive resin composition comprises (A) and (a).
The repeating unit (I) derived from a monomer having one polymerizable carbon-carbon double bond, and (b) two or more polymerizable carbon-carbon double bonds are decomposed by the action of an acid. At least one divalent ester group and / or carbonate group;
And a repeating unit (II) derived from a monomer having a structure in which each carbon-carbon double bond is connected via the divalent group. , And (B) a radiation-sensitive acid generator.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation-sensitive resin composition.
The present invention relates to a radiation-sensitive resin composition useful as a chemically amplified positive resist suitable for fine processing using various radiations such as a beam or a charged particle beam.

[0002]

2. Description of the Related Art In the field of microfabrication represented by the manufacture of integrated circuit elements, design rules in lithography have been rapidly miniaturized in order to obtain a higher degree of integration of integrated circuits. The development of a lithography process capable of stably performing high-precision fine processing with a line width of 0.5 μm or less has been strongly promoted. However, conventional visible light (wavelength 700 to 40)
However, it is difficult to form such a fine pattern with high precision by a method using near-ultraviolet (0 nm) or near-ultraviolet light (wavelength: 400 to 300 nm). Therefore, a wider depth of focus can be achieved, which is effective for miniaturization of design rules. A lithography process using radiation having a very short wavelength (wavelength of 300 nm or less) has been proposed. Lithography processes using such short wavelength radiation include, for example, Kr
Methods have been proposed that use far ultraviolet rays such as F excimer laser (wavelength 248 nm) and ArF excimer laser (wavelength 193 nm), or charged particle beams such as X-rays or electron beams such as synchrotron radiation. International Business Machines (IBM) has proposed a "chemically amplified resist" as a high-resolution resist for these short-wavelength radiations. Currently, the development and improvement of this chemically amplified resist is vigorous. It is being advanced. A chemically amplified resist generates an acid by irradiating a radiation-sensitive acid generator contained therein with a radiation, and a catalytic reaction of the acid causes a chemical reaction (for example, a change in polarity or a chemical bond) in the resist film. (A cleavage reaction, a cross-linking reaction, etc.), and a pattern is formed by using a phenomenon in which solubility in a developing solution changes in a radiation-irradiated portion. Among the conventional chemically amplified resists, those exhibiting relatively good resist performance include, as a resin component, a resin in which an alkali-affinity group in an alkali-soluble resin is protected with a t-butyl ester group or a t-butoxycarbonyl group. (See Japanese Patent Publication No. 2-27660), a resin in which an alkali-affinity group in an alkali-soluble resin is protected with a ketal group (see Japanese Patent Application Laid-Open No. Hei 7-140666), and an alkali-affinity group in an alkali-soluble resin is converted into an acetal group. (Japanese Patent Application Laid-Open Nos. 2-161436 and 5-24)
No. 9682) is known. However, it has been pointed out that each of these chemically amplified resists has its own problems and involves various difficulties in practical use. One of the major problems is the post-exposure time between irradiation and baking after irradiation (hereinafter referred to as “post-bake”).
me Delay, hereinafter referred to as “PED”. ), The line width of the resist pattern changes, or the resist pattern becomes T-shaped. In addition to these problems, the resolution fluctuation due to PED, the dependence on baking temperature, etc. are large, and the process stability is insufficient, and further improvement is required from the viewpoint of the overall characteristics as a chemically amplified resist. ing. By the way, among the above-mentioned chemically amplified resists, a positive resist (hereinafter referred to as “type”) containing a copolymer of hydroxystyrene and t-butyl acrylate as a resin component, and a phenolic property of poly (hydroxystyrene) It has been reported that a positive resist (hereinafter, referred to as “type”) using a resin component in which a hydroxyl group is protected by a ketal group or an acetal group is relatively resistant to the above-mentioned problems. However, since the type resist contains a large amount of an acrylic component having a small absorption coefficient at a wavelength of 248 nm, the effect of the standing wave increases, the pattern shape is damaged, and the resolution is inferior. Has the disadvantage of low heat resistance and the pattern shape is easily deformed by heat, and these resists can simultaneously satisfy various required characteristics including resolution, heat resistance, etc., as demand for miniaturization increases. Can not.

[0003]

SUMMARY OF THE INVENTION In view of such circumstances, the present invention has been found, in particular, as a result of a more detailed study of the resin component constituting a chemically amplified resist. Effectively responds to radiation, has excellent sensitivity and resolution, and is less affected by standing waves.
An object of the present invention is to provide a radiation-sensitive resin composition which is useful as a chemically amplified positive resist having excellent pattern shape and high heat resistance.

[0004]

According to the present invention, the above objects are attained by (A) (a) a monomer having one polymerizable carbon-carbon double bond in which the carbon-carbon double bond is cleaved. And a repeating unit (I) obtained by the following formula (1) or (b) having at least two polymerizable carbon-carbon double bonds and decomposing by the action of an acid: A monomer having at least one divalent group represented by the above formula, wherein each of the carbon-carbon double bonds has a structure linked via the divalent group. A copolymer containing a repeating unit (II) obtained by cleavage of a bond, and (B) a radiation-sensitive resin composition comprising a radiation-sensitive acid generator.

[0005]

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[0006]

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[In the structural formulas (1) and (2), R ¹ , R ² , R ³ and R ⁴ are each independently an alkyl group having 1 to 5 carbon atoms or an aryl group having 6 to 14 carbon atoms. Is shown. ] Is achieved.

Hereinafter, the present invention will be described in detail. (A) Copolymer The (A) copolymer used in the present invention comprises a copolymer containing the repeating unit (I) and the repeating unit (II). As the repeating unit (I), for example,
(A) a repeating unit (hereinafter referred to as “repeating unit (I-1)”) having an action of rendering the copolymer alkali-soluble;
A repeating unit which is decomposed by the action of an acid to render the copolymer (A) alkali-soluble (hereinafter referred to as “repeating unit (I-2)”), and reduces the alkali-solubility of the copolymer (A) And a recurring unit (hereinafter referred to as “repeating unit (I-3)”) showing the action to be performed.

The monomer that gives the repeating unit (I-1) (hereinafter referred to as "monomer (I-1)") includes, for example, a monomer having an acidic functional group such as a carboxyl group or a phenolic hydroxyl group. Mers. Specific examples of the monomer having a carboxyl group among such monomers (I-1) include (meth) acrylic acid, crotonic acid,
Cinnamic acid, maleic acid, fumaric acid, itaconic acid, 2-
Examples thereof include (meth) acryloyloxyethyl carboxylic acid and 4- (meth) acryloyloxycyclohexyl carboxylic acid. Specific examples of the monomer having a phenolic hydroxyl group include o-hydroxystyrene and m-hydroxystyrene. Hydroxystyrene, p-hydroxystyrene, o-isopropenylphenol, m-isopropenylphenol, p-isopropenylphenol and the like can be mentioned. These monomers (I-1) can be used alone or in combination of two or more.

The monomer that gives the repeating unit (I-2) (hereinafter, referred to as “monomer (I-2)”) is, for example, a carboxyl group, a phenolic hydroxyl group, or the like, which is decomposed by the action of an acid. And a monomer that forms an acidic functional group. Specific examples of such a monomer (I-2) which decomposes under the action of an acid to form a carboxyl group include t-butyl (meth) acrylate and tetrahydropyranyl (meth) acrylate. , 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2-t-butoxycarbonylethyl (meth) acrylate, 2-cyanoethyl (meth)
(Meth) acrylates protected with an acid-decomposable ester group such as acrylate; o- (t-butoxycarbonylmethoxy) styrene, m- (t-butoxycarbonylmethoxy) styrene, p- (t-butoxycarbonylmethoxy) styrene And hydroxy (α-methyl) styrene derivatives protected with acid-decomposable ester groups such as α-methyl substituents.

Specific examples of the monomer which is decomposed by the action of an acid to form a phenolic hydroxyl group include p- (1
-Methoxyethoxy) styrene, p- (1-ethoxyethoxy) styrene, p- (1-n-propoxyethoxy) styrene, p- (1-i-propoxyethoxy) styrene, p- (1-cyclohexyloxyethoxy) styrene , P- (1-isobornyloxyethoxy) styrene and hydroxy (α-methyl) styrenes protected with an acetal group such as α-methyl substituents thereof;
Acetoxystyrene, pt-butoxycarbonyloxystyrene, pt-butoxystyrene, and their α
-Methyl substituent and the like. These monomers (I-2) can be used alone or in combination of two or more.

Examples of the monomer that gives the repeating unit (I-3) (hereinafter, referred to as “monomer (I-3)”) include styrene, α-methylstyrene, p-methylstyrene, and p-methylstyrene. Aromatic vinyl compounds such as chlorostyrene and p-methoxystyrene; heteroatom-containing alicyclic vinyl compounds such as N-vinylpyrrolidone and N-vinylcaprolactam; vinyl compounds containing cyano groups such as (meth) acrylonitrile and vinylidene cyanide; (Meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N
-(Meth) acrylamide (derivatives) such as dimethylol (meth) acrylamide; methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, i-propyl (meth) acrylate, 2-hydroxyethyl ( Meth) acrylate, 2-
Hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, phenyl (meth)
Acrylate, cyclohexyl (meth) acrylate,
Benzyl (meth) acrylate, isobornyl (meth)
Acrylate and tricyclodecanyl (meth) acrylate can be exemplified. These monomers (I-3)
Can be used alone or in combination of two or more.

The repeating unit (I) in the present invention is preferably a repeating unit (I-2), and particularly, t-butyl (meth) acrylate, tetrahydropyranyl (meth) acrylate, p- (1-ethoxyethoxy) Styrene, pt-butoxycarbonyloxystyrene, p
-T-butoxystyrene and the like are preferred. The content of the repeating unit (I-2) in the repeating unit (I) is usually 2
0% by weight or more, preferably 20 to 60% by weight, more preferably 25 to 50% by weight. Repeating unit (I)
May be present alone or in combination of two or more in the copolymer (A). (A) The content of the repeating unit (I) in the copolymer is as follows:
Usually, it is 60 to 99% by weight, preferably 70 to 98% by weight, more preferably 75 to 97% by weight. In this case, when the content of the repeating unit (I) is less than 60% by weight,
The resolution as a resist tends to decrease, while 9
If it exceeds 9% by weight, the content of the repeating unit (II) becomes relatively small, and the sensitivity as a resist, the adhesiveness to a substrate, and the like tend to decrease.

Next, the repeating unit (II) reduces the motility of the polymer molecular chain by introducing an appropriate branched structure into the copolymer (A), thereby suppressing thermal deformation and improving heat resistance. Is a unit having an action of improving the above and an action of decomposing by the action of an acid to lower the molecular weight of the copolymer (A). At the same time, the branched structure is introduced into the copolymer (A) by the repeating unit (II), so that the viscosity of the polymer solution can be reduced as compared with the case of the linear polymer, and as a result, (A) The copolymer can have a higher molecular weight, the heat resistance as a resist can be further improved, and the resolution can be improved. Further, the repeating unit (II) has a specific group which is decomposed by the action of an acid, and the group is decomposed by the action of an acid, whereby the branched structure in the copolymer (A) is broken and the molecular weight is reduced. Therefore, the solubility of the copolymer (A) in the presence of an acid is further improved, and the resolution as a resist is dramatically improved.

A monomer which gives the repeating unit (II)
It is called "monomer (II)". ) Is a divalent ester group represented by the structural formula (1) (hereinafter referred to as “ester group (1)”).
That. Or a monomer having at least one divalent carbonate group represented by the structural formula (2) (hereinafter, referred to as “carbonate group (2)”). Among such monomers (II), the monomer (II) having an ester group (1) is, for example, a polyhydric alcohol having at least one tertiary hydroxyl group and a polymerizable carbon-carbon dimer. It can be synthesized by subjecting a monovalent carboxylic acid having one heavy bond to an esterification reaction. The esterification reaction includes, for example, an acid chloride method of reacting the acid chloride of the carboxylic acid compound with the polyhydric alcohol, and a method of reacting the polyhydric alcohol with the carboxylic acid compound using a condensing agent such as dicyclohexylcarbodiimide. A method of reacting the polyhydric alcohol with the carboxylic acid compound using a strong acid anhydride such as trifluoroacetic anhydride as a dehydrating agent; a transesterification method between the polyhydric alcohol and an ester of the carboxylic acid compound; Can be implemented.

The polyhydric alcohol having a tertiary hydroxyl group used in the synthesis of the monomer (II) having an ester group (1) includes, for example, compounds represented by the following general formulas (3) to (6): And the like.

[0017]

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[In the general formula (3), each R represents R ¹ , R ² , R ³ and R in the structural formulas (1) and (2).
Has the same meaning as ⁴ , a plurality of Rs may be the same or different from each other, and R ⁵ represents an i-valent organic group, or
= 2 indicates a single bond, and i is an integer of 2 to 4. ]

[0019]

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[In the general formula (4), each R represents R ¹ , R ² , R ³ and R in the structural formulas (1) and (2).
Has the same meaning as ⁴ , a plurality of R may be the same or different from each other, R ⁶ represents an alkyl group having 1 to 5 carbon atoms,
A plurality of R ⁶ may be the same or different from each other, and j
Is an integer of 2 to 4, m is an integer of 0 to 4, and j + m ≦ 6. ]

[0021]

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[In the general formula (5), each R represents R ¹ , R ² , R ³ and R in the structural formulas (1) and (2).
Synonymous with ⁴ , a plurality of R may be the same or different from each other, R ⁷ represents an alkyl group having 1 to 5 carbon atoms,
A plurality of R ⁷ may be the same or different from each other,
⁸ is a z-valent organic group, -O-, -S-, -CO- or-
Represents SO ₂ —, k is 1 or 2, n is an integer of 0 to 3,
z is an integer of 2 to 4. As the compound represented by the general formula (3), for example, 2,3-dimethyl-2,3-butanediol, 2,3-diethyl-2,3-butanediol, 2,3-di-n- Propyl-2,3-butanediol, 2,3-diphenyl-2,3-butanediol,
2,4-dimethyl-2,4-pentanediol, 2,4
-Diethyl-2,4-pentanediol, 2,4-di-
n-propyl-2,4-pentanediol, 2,4-diphenyl-2,4-pentanediol, 2,5-dimethyl-2,5-hexanediol, 2,5-diethyl-
2,5-hexanediol, 2,5-di-n-propyl-2,5-hexanediol, 2,5-diphenyl-
2,5-hexanediol, 2,6-dimethyl-2,6
Divalent such as -heptanediol, 2,6-diethyl-2,6-heptanediol, 2,6-di-n-propyl-2,6-heptanediol, and 2,6-diphenyl-2,6-heptanediol Tertiary alcohols; 2,4-dimethyl-2,4-dihydroxy-3- (2-hydroxypropyl) pentane, 2,4-diethyl-2,4-dihydroxy-3- (2-hydroxypropyl) pentane,
2,5-dimethyl-2,5-dihydroxy-3- (2-
Hydroxypropyl) hexane, 2,5-diethyl-
Trivalent tertiary alcohols such as 2,5-dihydroxy-3- (2-hydroxypropyl) hexane; 2,4-dimethyl-2,4-dihydroxy-3,3-di (2-hydroxypropyl) pentane; 2,4-diethyl-2,4
-Dihydroxy-3,3-di (2-hydroxypropyl) pentane, 2,5-dimethyl-2,5-dihydroxy-3,4-di (2-hydroxypropyl) hexane,
Examples include tetravalent tertiary alcohols such as 2,5-diethyl-2,4-dihydroxy-3,4-di (2-hydroxypropyl) hexane.

The compound represented by the general formula (4) includes, for example, 1,4-di (2-hydroxypropyl)
Benzene, 1,3-di (2-hydroxypropyl) benzene, 1,3,5-tri (2-hydroxypropyl) benzene, 1,2,4,5-tetra (2-hydroxypropyl) benzene and the like are mentioned. Can be. Examples of the compound represented by the general formula (5) include, for example, 2,2-bis {4- (2-hydroxypropyl) phenyl} propane and 1,2,2-tris {4- (2-hydroxypropyl) ) Phenyl｝ propane, 1,2,3,4-tetra ｛4
-(2-hydroxypropyl) phenyl} butane, bis {4- (2-hydroxypropyl) phenyl} ether, bis {4- (2-hydroxypropyl) phenyl}
Examples thereof include sulfide, bis {4- (2-hydroxypropyl) phenyl} ketone, and bis {4- (2-hydroxypropyl) phenyl} sulfone.

Of the di- or tetravalent tertiary alcohols represented by the general formulas (3) to (5), particularly, 2,5-dimethyl-2,5-hexanediol and 1,4-di ( 2-Hydroxypropyl) benzene, 1,3-di (2-hydroxypropyl) benzene and the like are preferred. Examples of the monovalent carboxylic acid having one polymerizable carbon-carbon double bond used when synthesizing the monomer (II) having the ester group (1) include, for example, the monomer (I- The same compounds as the monomers having a carboxyl group exemplified in 1) can be exemplified.

The monomer (II) having a carbonate group (2) can be obtained, for example, by subjecting a polyhydric alcohol having at least one tertiary hydroxyl group to poly (chloroformation) with phosgene or the like. It can be synthesized by reacting with a monohydric alcohol having one polymerizable carbon-carbon double bond. Examples of the polyhydric alcohol having at least one tertiary hydroxyl group used in synthesizing the monomer (II) having a carbonate group (2) include:
The same divalent to tetravalent tertiary alcohol as used in the synthesis of the monomer (II) having the ester group (1) can be mentioned. Among such 2- to 4-valent tertiary alcohols, in particular, 2,5-dimethyl-2,5-hexanediol, 1,4-di (2-hydroxypropyl) benzene, 1,3-di (2- Hydroxypropyl) benzene and the like are preferred. Examples of the monohydric alcohol having one polymerizable carbon-carbon double bond used in synthesizing the monomer (II) having a carbonate group (2) include, for example, o-hydroxystyrene and m-hydroxystyrene. Hydroxystyrenes such as -hydroxystyrene, p-hydroxystyrene, o-isopropenylphenol, m-isopropenylphenol, p-isopropenylphenol; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth)
Examples thereof include hydroxyalkyl (meth) acrylates such as acrylate, 3-hydroxybutyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate. The repeating unit (II) may exist alone or in combination of two or more in the copolymer (A).

(A) Repeating unit (II) in copolymer
Is usually 1 to 40% by weight, preferably 2 to 3% by weight.
0% by weight, more preferably 3 to 25% by weight. In this case, if the content of the repeating unit (II) is less than 1% by weight, the sensitivity as a resist and the adhesion to a substrate tend to decrease, while if it exceeds 40% by weight, the resolution as a resist decreases. Tend.

(A) The copolymer is prepared by, for example, a method of (a) directly copolymerizing the monomer (I) and the monomer (II),
(B) p-acetoxystyrene and the monomer (II) are optionally copolymerized with a monomer (I) other than p-acetoxystyrene, and then subjected to a hydrolysis reaction under basic conditions, of p-hydroxystyrene and monomer (II)
In some cases, monomers (I) other than p-acetoxystyrene
(C) converting at least a part of the phenolic hydroxyl groups in the copolymer obtained by the method (b) to a 1-ethoxyethoxy group, a t-butoxycarbonyloxy group, or the like. It can be produced by a method of protecting with a group that is decomposed by the action of an acid. (A) ~
The polymerization in the method (c) can be carried out by a known method using a polymerization initiator, a molecular weight regulator and the like. Examples of the polymerization initiator include benzoyl peroxide, lauroyl peroxide, 2,2′-azobisisobutyronitrile, 4,4′-azobis (4-cyanovaleric acid), and 2,2′-azobis ( 4-methoxy-2,
4-dimethylvaleronitrile) and the like. These polymerization initiators can be used alone or in combination of two or more. Examples of the molecular weight regulator include halogenated hydrocarbons such as carbon tetrachloride, chloroform and carbon tetrabromide; n-hexylmercaptan, n-octylmercaptan, n-dodecylmercaptan, t-dodecylmercaptan, Examples thereof include mercaptans such as glycolic acid and thiopropionic acid; xanthogens such as dimethyl xanthogen disulfide and diisopropylxanthogen disulfide; terpinolene and α-methylstyrene dimer. These molecular weight regulators can be used alone or in combination of two or more.

(A) The weight average molecular weight (hereinafter referred to as “Mw”) of the copolymer in terms of polystyrene measured by gel permeation chromatography (GPC) is usually 1
000-500,000, preferably 15,000
~ 200,000, more preferably 20,000 ~ 1
50,000. In this case, (A) Mw of the copolymer
Is less than 10,000, the sensitivity as a resist,
Heat resistance and the like tend to decrease, while if it exceeds 500,000, solubility in a developer tends to decrease. Further, the ratio (M) of the Mw of the copolymer (A) to the number average molecular weight in terms of polystyrene (hereinafter referred to as “Mn”) determined by gel permeation chromatography (GPC).
(w / Mn) is usually 1.5 to 10.0, preferably 2.0 to 5.0. In the present invention, the copolymer (A) can be used alone or in combination of two or more.

(B) Radiation-Sensitive Acid Generator The (B) radiation-sensitive acid generator used in the present invention comprises a compound that generates an acid upon irradiation with radiation (hereinafter, referred to as “exposure”). (B) Examples of the radiation-sensitive acid generator include the following onium salt compounds, sulfone compounds, sulfonic ester compounds, sulfonimide compounds, diazomethane compounds, and the like. Onium salt compound As the onium salt compound, for example, iodonium salt,
Sulfonium salts, phosphonium salts, diazonium salts, ammonium salts, pyridinium salts and the like can be mentioned. Specific examples of the onium salt compound include diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluorobutanesulfonate, diphenyliodonium pyrene sulfonate, diphenyliodonium dodecylbenzenesulfonate, diphenyliodonium hexafluoroantimonate, bis (4
-T-butylphenyl) iodonium trifluoromethanesulfonate, bis (4-t-butylphenyl) iodonium nonafluorobutanesulfonate, bis (4-
t-butylphenyl) iodonium camphorsulfonate, bis (4-t-butylphenyl) iodonium p
-Toluenesulfonate, triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium nonafluorobutanesulfonate, triphenylsulfonium camphorsulfonate, triphenylsulfonium naphthalene sulfonate, 4-hydroxyphenylbenzylmethylsulfonium p-toluenesulfonate, etc. . Sulfone compound As the sulfone compound, for example, β-ketosulfone,
Examples thereof include β-sulfonyl sulfone, and α-diazo compounds thereof. Specific examples of the sulfone compound include phenacylphenylsulfone, mesitylphenacylsulfone, bis (phenylsulfonyl) methane,
Trisphenacyl sulfone and the like can be mentioned. Sulfonic acid ester compound Examples of the sulfonic acid ester compound include an alkylsulfonic acid ester, a haloalkylsulfonic acid ester, an arylsulfonic acid ester, and iminosulfonate. Specific examples of the sulfonic acid ester compound include benzoin tosylate, pyrogallol tristrifluoromethanesulfonate, pyrogallol methanesulfonic acid triester, nitrobenzyl-9,
10-diethoxyanthracene-2-sulfonate, α
-Methylol benzoin tosylate, α-methylol benzoin octane sulfonate, α-methylol benzoin trifluoromethanesulfonate, α-methylol benzoindodecyl sulfonate and the like. Sulfonimide compound As the sulfonimide compound, for example, the following formula (6)
Can be mentioned.

[0030]

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[In the formula (6), Q is an alkylene group,
Represents a divalent group such as an arylene group or an alkoxylene group,
R ⁹ represents a monovalent group such as an alkyl group, an aryl group, a halogen-substituted alkyl group and a halogen-substituted aryl group. Specific examples of the sulfonimide compound include N- (trifluoromethylsulfonyloxy) succinimide, N-
(Trifluoromethylsulfonyloxy) phthalimide, N- (trifluoromethylsulfonyloxy) diphenylmaleimide, N- (trifluoromethylsulfonyloxy) bicyclo [2.2.1] hept-5-ene-
2,3-dicarboximide, N- (trifluoromethylsulfonyloxy) -7-oxabicyclo [2.2.
1] Hept-5-ene-2,3-dicarboximide, N
-(Trifluoromethylsulfonyloxy) bicyclo [2.2.1] heptane-5,6-oxy-2,3-dicarboximide, N- (trifluoromethylsulfonyloxy) naphthylimide, N- (camphorsulfonyloxy) ) Succinimide, N- (camphorsulfonyloxy) phthalimide, N- (camphorsulfonyloxy) diphenylmaleimide, N- (camphorsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide N- (camphorsulfonyloxy) -7-oxabicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (camphorsulfonyloxy) bicyclo [2.2.1] heptane -5,6-oxy-2,3-dicarboximide, N
-(Camphorsulfonyloxy) naphthylimide, N
-(4-methylphenylsulfonyloxy) succinimide, N- (4-methylphenylsulfonyloxy) phthalimide, N- (4-methylphenylsulfonyloxy) diphenylmaleimide, N- (4-methylphenylsulfonyloxy) bicyclo [2. 2.1] Hept-5
-Ene-2,3-dicarboximide, N- (4-methylphenylsulfonyloxy) -7-oxabicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- ( 4-methylphenylsulfonyloxy)
Bicyclo [2.2.1] heptane-5,6-oxy-
2,3-dicarboximide, N- (4-methylphenylsulfonyloxy) naphthylimide, N- (2-trifluoromethylphenylsulfonyloxy) succinimide, N- (2-trifluoromethylphenylsulfonyloxy) phthalimide, N- (2-trifluoromethylphenylsulfonyloxy) phthalimide -(2-trifluoromethylphenylsulfonyloxy) diphenylmaleimide, N
-(2-trifluoromethylphenylsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3
-Dicarboximide, N- (2-trifluoromethylphenylsulfonyloxy) -7-oxabicyclo [2.
2.1] Hept-5-ene-2,3-dicarboximide, N- (2-trifluoromethylphenylsulfonyloxy) bicyclo [2.2.1] heptane-5,6-oxy-2,3- Dicarboximide, N- (2-trifluoromethylphenylsulfonyloxy) naphthylimide, N- (4-fluorophenylsulfonyloxy) succinimide, N- (4-fluorophenylsulfonyloxy) phthalimide, N- (4-fluorophenyl Sulfonyloxy) diphenylmaleimide, N- (4-fluorophenylsulfonyloxy) bicyclo [2.2.
1] Hept-5-ene-2,3-dicarboximide, N
-(4-Fluorophenylsulfonyloxy) -7-oxabicyclo [2.2.1] hept-5-ene-2,3
-Dicarboximide, N- (4-fluorophenylsulfonyloxy) bicyclo [2.2.1] heptane-5,
6-oxy-2,3-dicarboximide, N- (4-fluorophenylsulfonyloxy) naphthylimide and the like can be mentioned.

Diazomethane Compound Examples of the diazomethane compound include compounds represented by the following formula (7).

[0033]

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[In the formula (7), R ¹⁰ and R ¹¹ each independently represent a monovalent group such as an alkyl group, an aryl group, a halogen-substituted alkyl group and a halogen-substituted aryl group. Specific examples of the diazomethane compound include bis (trifluoromethylsulfonyl) diazomethane, bis (cyclohexylsulfonyl) diazomethane, bis (phenylsulfonyl) diazomethane, bis (p-toluenesulfonyl) diazomethane, methylsulfonyl-p-toluenesulfonyldiazomethane, Examples thereof include 1-cyclohexylsulfonyl-1- (1,1-dimethylethylsulfonyl) diazomethane and bis (1,1-dimethylethylsulfonyl) diazomethane. Of these (B) radiation-sensitive acid generators, onium salt compounds, sulfonic acid ester compounds, sulfonimide compounds and diazomethane compounds are preferred, and bis (4-t-
Butylphenyl) iodonium nonafluorobutanesulfonate, bis (4-t-butylphenyl) iodonium camphorsulfonate, bis (4-t-butylphenyl) iodonium p-toluenesulfonate, triphenylsulfonium trifluoromethanesulfonate,
Triphenylsulfonium nonafluorobutanesulfonate, α-methylolbenzoin tosylate, α-methylolbenzoinoctanesulfonate, α-methylolbenzointrifluoromethanesulfonate, α-methylolbenzoindodecylsulfonate, pyrogallol methanesulfonic acid triester, N- (trifluoromethyl Sulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (camphorsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3- Dicarboximide, N- (camphorsulfonyloxy) naphthylimide, bis (cyclohexylsulfonyl) diazomethane and the like are preferred. In the present invention, the radiation-sensitive acid generator (B) can be used alone or in combination of two or more.

(B) The amount of the radiation-sensitive acid generator used is:
It is usually 1 to 20 parts by weight, preferably 1 to 10 parts by weight, per 100 parts by weight of the copolymer (A). in this case,
(B) If the amount of the radiation-sensitive acid generator is less than 1 part by weight, it may be difficult to sufficiently cause a chemical change due to the catalytic action of the acid generated by exposure, and if it exceeds 20 parts by weight. When the composition is applied, there is a possibility that unevenness in application may occur or undeveloped portion (scum) may occur during development.

Acid Diffusion Control Agent In the present invention, the diffusion phenomenon of the acid generated from the radiation-sensitive acid generator (B) in the resist film by exposure is controlled to prevent an undesired chemical reaction in the unexposed area. It is preferable to add an acid diffusion controller having an inhibitory action or the like. By using such an acid diffusion controller, the storage stability of the composition is improved, the resolution as a resist is improved, and the line width change of the resist pattern due to PED can be suppressed. Is extremely excellent. As the acid diffusion control agent is preferably a nitrogen-containing organic compounds of which the basicity does not change during exposure or baking, and specific examples thereof, wherein R ¹²
R ¹³ R ¹⁴ N (where R ¹² , R ¹³ and R ¹⁴ independently represent a hydrogen atom, an alkyl group, an aryl group or an aralkyl group) (hereinafter referred to as “nitrogen-containing compound (α ) "), A diamino compound having two nitrogen atoms in the same molecule (hereinafter, referred to as" nitrogen-containing compound (β) "), a polymer having three or more nitrogen atoms (hereinafter, referred to as" nitrogen-containing compound ( γ) ”)), an amide group-containing compound,
Examples include urea compounds and nitrogen-containing heterocyclic compounds.

As the nitrogen-containing compound (α), for example, n
Monoalkylamines such as hexylamine, n-heptylamine, n-octylamine, n-nonylamine and n-decylamine; di-n-butylamine, di-n-pentylamine, di-n-hexylamine, di- Dialkylamines such as n-heptylamine, di-n-octylamine, di-n-nonylamine, di-n-decylamine; triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine , Tri-n-hexylamine, tri-n-heptylamine,
Tri-n-octylamine, tri-n-nonylamine,
Tri-n-decylamine, tri-n-dodecylamine,
trialkylamines such as n-dodecyldimethylamine; aniline, N-methylaniline, N, N-dimethylaniline, 2-methylaniline, 3-methylaniline,
Examples thereof include aromatic amines such as 4-methylaniline, 4-nitroaniline, diphenylamine, triphenylamine, and naphthylamine.

Examples of the nitrogen-containing compound (β) include ethylenediamine, N, N, N ', N'-tetramethylethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4'-diaminodiphenylmethane,
4,4'-diaminodiphenyl ether, 4,4'-diaminobenzophenone, 4,4'-diaminodiphenylamine, 2,2-bis (4-aminophenyl) propane, 2- (3-aminophenyl) -2- (4 -Aminophenyl) propane, 2- (4-aminophenyl) -2-
(3-hydroxyphenyl) propane, 2- (4-aminophenyl) -2- (4-hydroxyphenyl) propane, 1,4-bis [1- (4-aminophenyl) -1-
Methylethyl] benzene, 1,3-bis [1- (4-aminophenyl) -1-methylethyl] benzene, and the like.

Examples of the nitrogen-containing compound (γ) include polymers of polyethyleneimine, polyallylamine, dimethylaminoethylacrylamide and the like. Examples of the amide group-containing compound include formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide,
N, N-dimethylacetamide, propionamide, benzamide, pyrrolidone, N-methylpyrrolidone and the like can be mentioned.

Examples of the urea compound include urea, methylurea, 1,1-dimethylurea, 1,3-
Examples thereof include dimethylurea, 1,1,3,3-tetramethylurea, 1,3-diphenylurea, and tributylthiourea. Examples of the nitrogen-containing heterocyclic compound include imidazole, benzimidazole,
Imidazoles such as -methylimidazole and 4-methyl-2-phenylimidazole; pyridine, 2-methylpyridine, 4-methylpyridine, 2-ethylpyridine, 4
-Ethylpyridine, 2-phenylpyridine, 4-phenylpyridine, N-methyl-4-phenylpyridine, nicotine, nicotinic acid, nicotinamide, quinoline, 8-
In addition to pyridines such as oxyquinoline and acridine, pyrazine, pyrazole, pyridazine, quinosaline, purine, pyrrolidine, piperidine, morpholine, 4-methylmorpholine, piperazine, 1,4-dimethylpiperazine, 1,4-diazabicyclo [2.2 .2] octane and the like.

Among these nitrogen-containing organic compounds, a nitrogen-containing compound (α) and a nitrogen-containing heterocyclic compound are preferable.
Among the nitrogen-containing compounds (α), trialkylamines are particularly preferred, and among the nitrogen-containing heterocyclic compounds, pyridines are particularly preferred. The acid diffusion controllers can be used alone or in combination of two or more. The amount of the acid diffusion controller to be used is generally 15 parts by weight or less, preferably 0.001 to 10 parts by weight, more preferably 0.005 to 5 parts by weight, per 100 parts by weight of the copolymer (A). In this case, when the use amount of the acid diffusion controller exceeds 15 parts by weight, the sensitivity as a resist and the developability of an exposed portion tend to decrease. The amount of the acid diffusion controller used was 0.001.
If the amount is less than part by weight, the pattern shape and dimensional fidelity as a resist may be reduced depending on the process conditions.

Alkali-soluble resin In the present invention, an alkali-soluble resin can be added, if necessary, in addition to the copolymer (A). The alkali-soluble resin is a resin which is soluble in an alkali developer and has at least one kind of a functional group having an affinity for an alkali developer such as a carboxyl group or a phenolic hydroxyl group. By using such an alkali-soluble resin, it becomes easy to control the dissolution rate of the resist film formed from the radiation-sensitive resin composition of the present invention in an alkali developer, thereby further improving developability. Can be. The alkali-soluble resin is not particularly limited as long as it is soluble in an alkali developer,
Examples include hydroxystyrenes, isopropenylphenols, vinylbenzoic acids, carboxymethylstyrenes, carboxymethoxystyrenes, (meth)
Polymerizable carbon-carbon double bonds of ethylenically unsaturated monomers having acidic functional groups such as acrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, mesaconic acid, and cinnamic acid are cleaved. And a polycondensation resin having at least one condensation type repeating unit having an acidic functional group represented by a novolak resin. The alkali-soluble resin composed of the addition polymerization resin may be composed of only a repeating unit in which a polymerizable carbon-carbon double bond of an ethylenically unsaturated monomer having an acidic functional group is cleaved. Thus, one or more other repeating units may be further contained. Examples of such other repeating units include, for example, styrene, α-methylstyrene, vinyltoluenes, maleic anhydride, (meth) acrylonitrile, crotononitrile, maleinitrile, fumaronitrile, mesaconnitrile, citraconitrile, itaconnitrile, Polymerization of (meth) acrylamide, crotonamide, maleamide, fumaramide, mesaconamide, citraconamide, itaconamide, vinylanilines, vinylpyridines, N-vinyl-ε-caprolactam, N-vinylpyrrolidone, N-vinylimidazole and the like And a repeating unit in which the carbon-carbon double bond is cleaved. Among the addition-polymer resins, poly (hydroxystyrene) s and isopropenylphenol copolymers are particularly preferable from the viewpoint of high radiation permeability when formed into a resist film and excellent dry etching resistance.

The alkali-soluble resin composed of the polycondensation resin may be composed of only a condensation type repeating unit having an acidic functional group. However, in some cases, one or more other condensation type repeating units may be used. Further, it can be contained. Such polycondensation resins include, for example, one or more phenols and one or more aldehydes, optionally together with a polycondensation component capable of forming another condensation-type repeating unit, of an acidic catalyst or a basic catalyst. It can be produced by (co) polycondensation in an aqueous medium or in a mixed medium of water and a hydrophilic solvent in the presence. Examples of the phenols include o-cresol, m-cresol, p-cresol
-Cresol, 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 3,4-xylenol, 3,5-xylenol, 2,3,5-trimethylphenol, 3,4,5-trimethylphenol And the aldehydes include, for example, formaldehyde, trioxane, paraformaldehyde, benzaldehyde, acetaldehyde, propylaldehyde, phenylacetaldehyde and the like.

The Mw of the alkali-soluble resin is usually 1,
000-100,000, preferably 3,000-5
000, more preferably 3,000 to 30,000
0. In this case, Mw of the alkali-soluble resin is 1,
If it is less than 000, the resolution as a resist tends to decrease, while if it exceeds 100,000, the viscosity of the resist solution becomes high, and when applied to a substrate, the film thickness in the application area may become non-uniform. is there. The alkali-soluble resins can be used alone or in combination of two or more. The amount of the alkali-soluble resin used is usually 200 parts by weight or less per 100 parts by weight of the copolymer (A). In this case, the amount of the alkali-soluble resin used is 200
If the amount exceeds the weight part, the resolution as a resist tends to decrease.

Various additives The radiation-sensitive resin composition of the present invention may further contain various additives such as a surfactant and a sensitizer, if necessary. The surfactant has an effect of improving the coating property and striation of the composition, the developability as a resist, and the like. Examples of such surfactants include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene nonyl phenyl ether, polyethylene glycol dilaurate, and polyethylene glycol dilaurate. Stearate and the like can be mentioned. The amount of the surfactant is usually 2 parts by weight or less per 100 parts by weight of the copolymer (A). The sensitizer absorbs radiation energy and transmits the energy to the radiation-sensitive acid generator (B) to thereby increase the amount of acid generated by exposure to light. It has the effect of improving the apparent sensitivity. Examples of preferred sensitizers include benzophenones, rose bengals, anthracenes, acetophenones, pyrenes, phenothiazines and the like. The compounding amount of the sensitizer
(A) It is usually 50 parts by weight or less per 100 parts by weight of the copolymer. In addition, by blending a dye and / or a pigment, the latent image in the exposed area can be visualized and the effect of halation during exposure can be reduced, and the adhesion to the substrate can be further improved by blending an adhesion aid. can do. Further, as other additives, for example, an antihalation agent, a shape improving agent, a storage stabilizer, an antifoaming agent, and the like can be blended.

Solvent The radiation-sensitive resin composition of the present invention may be used,
After uniformly dissolving in a solvent so that the concentration of the total solid content is usually 3 to 50% by weight, preferably 5 to 40% by weight, the composition is filtered by a filter having a pore size of about 0.2 μm, for example. It is prepared as a product solution. As the solvent used for preparing the composition solution, for example, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol mono-n-propyl ether acetate, ethylene glycol mono-n-butyl ether acetate, etc. Glycol monoalkyl ether acetates; propylene glycol monoalkyl ethers such as propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-n-propyl ether, and propylene glycol mono-n-butyl ether; propylene glycol dimethyl ether, propylene glycol diethyl Ether, propylene glycol di-n-propyl ether,
Propylene glycol dialkyl ethers such as propylene glycol di-n-butyl ether; propylene glycol such as propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol mono-n-propyl ether acetate, propylene glycol mono-n-butyl ether acetate; Monoalkyl ether acetates; methyl lactate, ethyl lactate, n-propyl lactate;
Lactate esters such as i-propyl lactate; ethyl acetate, n-propyl acetate, i-propyl acetate, n-butyl acetate;
Aliphatic carboxylic acid esters such as i-butyl acetate, n-amyl acetate, i-amyl acetate, i-propyl propionate, n-butyl propionate and i-butyl propionate; methyl 3-methoxypropionate, Ethyl methoxypropionate, methyl 3-ethoxypropionate,
Ethyl 3-ethoxypropionate, methyl pyruvate,
Other esters such as ethyl pyruvate; aromatic hydrocarbons such as toluene and xylene; ketones such as 2-heptanone, 3-heptanone, 4-heptanone and cyclohexanone; N, N-dimethylformamide, N-methylacetamide Amides such as N, N-dimethylacetamide and N-methylpyrrolidone; lactones such as γ-butyrolactone; These solvents are used alone or in combination of two or more.

Formation of Resist Pattern When forming a resist pattern from the radiation-sensitive resin composition of the present invention, the composition solution prepared as described above is applied by spin coating, casting coating, roll coating, or the like. For example, a resist film is formed by applying a suitable coating means on a substrate such as a silicon wafer or a wafer coated with aluminum, and a heat treatment (hereinafter, referred to as “pre-bake”) is performed in advance in some cases. After that, exposure is performed through a predetermined mask pattern. The radiation used at this time is, for example, ultraviolet light represented by i-ray (wavelength 365 nm), an ArF excimer laser (wavelength 193 nm), or a KrF excimer laser depending on the type of the radiation-sensitive acid generator (B). (A wavelength of 248 nm), a charged particle beam represented by an X-ray represented by synchrotron radiation, or a charged particle beam represented by an electron beam. Exposure conditions such as the amount of exposure are appropriately selected according to the composition of the composition, types of additives, and the like. In the present invention, it is preferable to perform post-baking in order to improve the apparent sensitivity of the resist film. The heating conditions vary depending on the composition of the composition, types of additives, etc., but are usually 30 to 200 ° C., preferably 40 to 15 ° C.
0 ° C. Next, the exposed resist film is usually treated with an alkali developing solution at 10 to 50 ° C. for a developing time of 30 minutes.
By developing under conditions of up to 200 seconds, a predetermined resist pattern is formed. Examples of the alkali developer include mono-, di- or tri-alkylamines; mono-, di- or tri-alkanolamines; heterocyclic amines; tetraalkylammonium hydroxides; choline; -Diazabicyclo [5.
4.0] -7-undecene, 1,5-diazabicyclo [4.3.0] -5-nonene and at least one kind of alkaline compound, usually 1 to 10% by weight, preferably 1 to 10% by weight.
An alkaline aqueous solution dissolved to a concentration of about 5% by weight is used. Further, for example, an appropriate amount of a water-soluble organic solvent such as methanol or ethanol or a surfactant may be added to the developer comprising the alkaline aqueous solution.
When a developer composed of an alkaline aqueous solution is used as described above, the developer is generally washed with water after development. In forming the resist pattern, a protective film may be provided on the resist film in order to prevent the influence of basic impurities and the like contained in the environmental atmosphere.

[0048]

Embodiments of the present invention will be described below more specifically with reference to examples. However, the present invention is not limited to these embodiments. The measurement of Mw and Mn and the evaluation of each resist in Examples and Comparative Examples were performed as follows. Mw and Mn GPC columns manufactured by Tosoh Corporation (G2000H _XL two,
G3000H _XL 1 present, using G4000H _XL 1 present), Flow rate: 1.0 ml / minute, eluting solvent tetrahydrofuran, in the analysis conditions of column temperature 40 ° C, by gel permeation chromatography for the monodisperse polystyrene as a standard (GPC) It was measured. The exposure amount for forming a line-and-space pattern (1L1S) having a sensitivity line width of 0.25 μm with a line width of 1: 1 was defined as the optimum exposure amount, and the sensitivity was evaluated based on this value. Resolution The minimum dimension (μm) of the resist pattern that was resolved when exposed at the optimum exposure amount was defined as the resolution. In the case of 1L1S having a pattern line width of 0.25 μm, a pattern having a substantially rectangular cross section and negligible influence of a standing wave was regarded as having a good pattern shape. The heat resistance was evaluated based on the maximum temperature (° C.) at which the pattern shape did not change when the substrate on which a square pattern with a side of 20 μm was formed was heated after drying after heat development.

(A) Synthesis of Copolymer Synthesis Example 1 23 g of t-butyl acrylate, 2.5-dimethyl-
4 g of 2.5-hexanediol diacrylate, 27 g of p-isopropenylphenol and 11 g of tricyclodecanyl acrylate were mixed with 78 g of propylene glycol monomethyl ether acetate to form a homogeneous solution. After bubbling the solution with nitrogen gas for 30 minutes, 3 g of 2,2'-azobisisobutyronitrile and t
-2 g of dodecyl mercaptan was added, and polymerization was carried out at 70 ° C for 24 hours while bubbling with nitrogen gas was continued.
After completion of the polymerization, the reaction solution was mixed with a large amount of hexane to coagulate the produced copolymer. Next, after redissolving the copolymer in dioxane, the operation of solidifying again with hexane is repeated several times to remove unreacted monomers,
Drying at 50 ° C. for 24 hours under reduced pressure gave a white copolymer. The obtained copolymer had Mw of 101,000 and Mw of
/ Mn is 4.7, ¹³ C-NMR and ¹ H-NM
As a result of the R measurement, the content ratio (weight ratio) of each monomer was
t-butyl acrylate: 2.5-dimethyl-2.5-
Hexanediol diacrylate: p-isopropenyl phenol: tricyclodecanyl acrylate = 35:
6:42:17. This copolymer is referred to as copolymer (A-1).

Synthesis Example 2 A monomer was prepared by adding 19 g of t-butyl acrylate and 2,5-dimethyl-2,5-hexanediol diacrylate 2
g, p-isopropenylphenol 19 g and isobornyl acrylate 10 g, except that a white copolymer was obtained in the same manner as in Synthesis Example 1. The obtained copolymer had Mw of 63,000 and Mw / Mn of 3.8,
^{As a result of 13} C-NMR and ¹ H-NMR measurements, the content ratio (weight ratio) of each monomer was determined as t-butyl acrylate: 2,5-dimethyl-2,5-hexanediol diacrylate: p- Isopropenylphenol: isobornyl acrylate (weight ratio) = 38: 4: 38: 20. This copolymer is referred to as copolymer (A-2).

Synthesis Example 3 10 g of t-butyl acrylate, 2.5-dimethyl-
2 g of 2.5-hexanediol diacrylate, 5 g of styrene, 46 g of p-acetoxystyrene and 1 g of t-dodecylmercaptan were mixed with 200 g of dioxane to form a homogeneous solution. After bubbling this solution with nitrogen gas for 30 minutes, 2 g of 2,2′-azobisisobutyronitrile was added, and polymerization was carried out at 70 ° C. for 7 hours while bubbling with nitrogen gas was continued. After completion of the polymerization, the reaction solution was mixed with a large amount of hexane to coagulate the produced copolymer. Next, after redissolving the copolymer in dioxane, the operation of coagulating again with hexane is repeated several times to remove unreacted monomers,
After drying for an hour, a white copolymer was obtained. Next, 24 g of this copolymer was mixed with 240 g of methanol, 15 g of triethylamine and 5 g of water, and a hydrolysis reaction was carried out for 8 hours while refluxing under heating. Thereafter, the reaction solution was put into a 1% by weight oxalic acid aqueous solution to coagulate the copolymer, washed with water, and then dried under reduced pressure at 50 ° C. for 24 hours.
A white copolymer was obtained. The obtained copolymer had Mw of 4
5,000, Mw / Mn is 4.2, ¹³ C-NMR
As a result of the measurement and ¹ H-NMR measurement, the ratio (weight ratio) of the content of each monomer was t-butyl acrylate: 2.5.
-Dimethyl-2.5-hexanediol diacrylate: styrene: p-hydroxystyrene = 21: 4: 1
0:65. This copolymer is referred to as copolymer (A-
3).

Synthesis Example 4 30 g of pt-butoxystyrene, 2.5-dimethyl-
4 g of 2.5-hexanediol diacrylate and p
-95 g of acetoxystyrene was mixed with 265 g of propylene glycol monomethyl ether to form a homogeneous solution. After bubbling this solution with nitrogen gas for 30 minutes, 9 g of 2,2′-azobisisobutyronitrile and 6 g of t-dodecylmercaptan were added, and polymerization was carried out at 70 ° C. for 24 hours while continuing bubbling with nitrogen gas. . After completion of the polymerization, the reaction solution was mixed with a large amount of hexane to coagulate the produced copolymer. Next, after redissolving the copolymer in acetone, the operation of coagulating again with hexane is repeated several times to remove unreacted monomers, and dried at 50 ° C. under reduced pressure for 24 hours to obtain a white copolymer. Obtained. Next, 50 g of this copolymer was added to methanol 5
The mixture was mixed with 00 g, 20 g of triethylamine and 10 g of water, and subjected to a hydrolysis reaction for 8 hours while refluxing under heating. Thereafter, the reaction solution was poured into a 1% by weight aqueous solution of oxalic acid to coagulate the copolymer, washed with water, and then reduced to 50 ° C. under reduced pressure.
For 24 hours to obtain a white copolymer. The obtained copolymer had Mw of 38,000 and Mw / Mn of 2.9.
As a result of ¹³ C-NMR measurement and ¹ H-NMR measurement, the content ratio (weight ratio) of each monomer was pt-butoxystyrene: 2.5-dimethyl-2.5-hexane. Diol diacrylate: p-hydroxystyrene = 3
1: 4: 65. This copolymer was designated as copolymer (A)
-4).

Synthesis Example 5 3 g of 2.5-dimethyl-2.5-hexanediol diacrylate and 97 g of p-acetoxystyrene were mixed with 100 g of propylene glycol monomethyl ether to form a homogeneous solution. After bubbling this solution with nitrogen gas for 30 minutes, 6 g of 2,2′-azobisisobutyronitrile and 4 g of t-dodecylmercaptan were added, and the mixture was heated at 70 ° C. while bubbling with nitrogen gas was continued.
For 24 hours. After completion of the polymerization, the reaction solution was mixed with a large amount of hexane to coagulate the produced copolymer. Then, after redissolving the copolymer in acetone, the operation of coagulating again with hexane is repeated several times to remove unreacted monomers, and dried under reduced pressure at 50 ° C. for 24 hours.
A white copolymer was obtained. Then, 60 g of this copolymer
Was mixed with 500 g of methanol, 20 g of triethylamine and 10 g of water, and a hydrolysis reaction was carried out for 8 hours while refluxing under heating. Thereafter, the reaction solution was poured into a 1% by weight aqueous solution of oxalic acid to coagulate the copolymer, washed with water, and then dried under reduced pressure at 50 ° C. for 24 hours to obtain a white copolymer. Next, 24 g of this copolymer was mixed with dioxane 1
After dissolving in 00 g, bubbling was performed with nitrogen gas for 30 minutes. 4.5 g of ethyl vinyl ether was added to this solution.
And 0.4 g of pyridinium p-toluenesulfonate as a catalyst were added, and an acetalization reaction was performed for 12 hours. Thereafter, the reaction solution is added dropwise to a 1% by weight aqueous ammonia solution to coagulate the product, washed with water, and then reduced under reduced pressure.
Drying at 24 ° C. for 24 hours gave a white copolymer. The obtained copolymer had Mw of 52,000 and Mw / Mn of 3.
As a result of ¹³ C-NMR and ¹ H-NMR measurements, the content ratio (weight ratio) of each monomer was 2.5-dimethyl-2.5-hexanediol diacrylate: p
-Hydroxystyrene: p- (1-ethoxyethoxy)
Styrene was 4:66:30. This copolymer is
Let it be a copolymer (A-5).

Synthesis Example 6 5 g of 2.5-dimethyl-2.5-hexanediol diacrylate and 95 g of p-acetoxystyrene were mixed with 100 g of propylene glycol monomethyl ether to form a homogeneous solution. After bubbling this solution with nitrogen gas for 30 minutes, 6 g of 2,2′-azobisisobutyronitrile and 4 g of t-dodecylmercaptan were added, and the mixture was heated at 70 ° C. while bubbling with nitrogen gas was continued.
For 24 hours. After completion of the polymerization, the reaction solution was mixed with a large amount of hexane to coagulate the produced copolymer. Then, after redissolving the copolymer in acetone, the operation of coagulating again with hexane is repeated several times to remove unreacted monomers, and dried under reduced pressure at 50 ° C. for 24 hours.
A white copolymer was obtained. Then, 60 g of this copolymer
Was mixed with 500 g of methanol, 20 g of triethylamine and 10 g of water, and a hydrolysis reaction was carried out for 8 hours while refluxing under heating. Thereafter, the reaction solution was poured into a 1% by weight aqueous solution of oxalic acid to coagulate the copolymer, washed with water, and then dried under reduced pressure at 50 ° C. for 24 hours to obtain a white copolymer. Next, 24 g of this copolymer was mixed with dioxane 1
After dissolving in 00 g, bubbling was performed with nitrogen gas for 30 minutes. After adding 5 g of triethylamine to this solution, 10 g of di-tert-butyl dicarbonate was added at 45 ° C. with stirring, and the mixture was reacted for 6 hours. Thereafter, the reaction solution was poured into a 1% by weight aqueous solution of oxalic acid to coagulate the copolymer, washed with water, and then dried under reduced pressure at 50 ° C. overnight.
A white copolymer was obtained. The resulting copolymer had an Mw of 7
3,000, Mw / Mn is 4.3, ¹³ C-NMR
As a result of ¹ H-NMR measurement, the content ratio (weight ratio) of each monomer was 2.5-dimethyl-2.5-hexanediol diacrylate: p-hydroxystyrene: p
-T-butoxycarbonyloxystyrene = 6: 69:
25. This copolymer is referred to as a copolymer (A-6).

Synthesis Example 7 A monomer having 23 g of t-butyl acrylate and a monomer having a carbonate group (2) represented by the following formula (8) (hereinafter, referred to as “monomer (8)”): A white copolymer was obtained in the same manner as in Synthesis Example 1 except that 4 g, 27 g of p-isopropenylphenol and 11 g of tricyclodecanyl acrylate were used. The obtained copolymer is Mw
Is 85,000, Mw / Mn is 4.5, and ¹³ C—N
As a result of the MR and ¹ H-NMR measurements, the ratio (weight ratio) of the content of each monomer was as follows: t-butyl acrylate: monomer (8): p-isopropenylphenol: tricyclodecanyl acrylate = 35 : 6:42:17.
This copolymer is referred to as a copolymer (A-7).

[0056]

Embedded image

Comparative Synthesis Example 1 10 g of t-butyl acrylate, 5 g of styrene, 50 g of p-acetoxystyrene and 0.4 g of t-dodecyl mercaptan were mixed with 200 g of dioxane to form a homogeneous solution. After bubbling this solution with nitrogen gas for 30 minutes, 2,2′-azobisisobutyronitrile 2 g
And continue bubbling with nitrogen gas.
Polymerization was carried out at 0 ° C. for 7 hours. After completion of the polymerization, the reaction solution was mixed with a large amount of hexane to coagulate the produced copolymer.
Next, after re-dissolving the copolymer in dioxane, the operation of coagulating again with hexane is repeated several times to remove unreacted monomers, and dried at 50 ° C. under reduced pressure for 24 hours to obtain a white copolymer. Obtained. Next, the copolymer 24
g was mixed with 240 g of methanol, 15 g of triethylamine and 5 g of water, and the mixture was subjected to a hydrolysis reaction for 8 hours while refluxing under heating. Thereafter, the reaction solution was poured into a 1% by weight aqueous solution of oxalic acid to coagulate the copolymer, washed with water, and then dried under reduced pressure at 50 ° C. for 24 hours to obtain a white copolymer. The obtained copolymer had Mw of 12,000 and M
w / Mn is 1.6, ¹³ C-NMR measurement and ¹ H
As a result of the NMR measurement, the content ratio (weight ratio) of each monomer was t-butyl acrylate: styrene: p-hydroxystyrene = 21: 10: 69. This copolymer is referred to as a copolymer (a-1).

[0058]

EXAMPLES Examples 1 to 6 and Comparative Example 1 After mixing the components of the formulation shown in Table 1 (parts based on weight) to form a uniform solution, the mixture was filtered through a membrane filter having a pore size of 0.2 μm. The composition solution was prepared by filtration. Thereafter, each composition solution was spin-coated on a silicon wafer, and then pre-baked (PB) at each temperature shown in Table 2 for 90 seconds to form a 0.7 μm-thick resist film. Next, a KrF excimer laser stepper (Nikon Corporation stepper NSR-2005 EX)
8A), and exposed at each temperature shown in Table 2
Post bake (PEB) was performed for 0 seconds. Then, 2.
Using a 38% by weight aqueous solution of tetramethylammonium hydroxide, alkali development was performed by a paddle method at 23 ° C. for 1 minute, followed by washing with pure water and drying to form a resist pattern. Table 2 shows the evaluation results of the respective resists.
The components other than the copolymer in Table 1 are as follows. Acid generator B-1: triphenylsulfonium nonafluorobutanesulfonate B-2: bis (cyclohexylsulfonyl) diazomethane B-3: bis (4-t-butylphenyl) iodonium camphorsulfonate Acid diffusion controller C-1: tri- n-octylamine C-2: n-dodecyldimethylamine Solvent D-1: ethyl lactate D-2: propylene glycol monomethyl ether acetate

[0059]

[Table 1]

[0060]

[Table 2]

[0061]

The radiation-sensitive resin composition of the present invention has excellent sensitivity and resolution, and is less affected by standing waves.
It is excellent in pattern shape and has high heat resistance, and effectively responds to various radiations such as ultraviolet rays, far ultraviolet rays, X-rays and charged particle beams. Therefore,
The radiation-sensitive resin composition of the present invention can be extremely suitably used as a chemically amplified positive resist for manufacturing semiconductor devices, which is expected to be further miniaturized in the future.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kazuo Kawaguchi 2-11-24 Tsukiji, Chuo-ku, Tokyo Inside JSR Corporation

Claims (1)

[Claims] (A) (a) a repeating unit (I) obtained by cleaving a carbon-carbon double bond of a monomer having one polymerizable carbon-carbon double bond, and (b) ) Polymerizable carbon-
A compound represented by the following structural formula (1) or (2) having two or more carbon double bonds and decomposing by the action of an acid;
A monomer having at least one divalent group, wherein the carbon-carbon double bond of a monomer having a structure in which each carbon-carbon double bond is connected via the divalent group is cleaved. A radiation-sensitive resin composition comprising: a copolymer containing the repeating unit (II) obtained as described above; and (B) a radiation-sensitive acid generator. Embedded image Embedded image [In the structural formulas (1) and (2), R ¹ , R
² , R ³ and R ⁴ independently represent an alkyl group having 1 to 5 carbon atoms or an aryl group having 6 to 14 carbon atoms. ]