JP2002202603A - Radiation sensitive resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radiation sensitive resin composition having such high sensitivity to radiation typified by far UV or charged particle beams as to require a small quantity of energy for exposure, excellent in resolving power and suitable for use as a chemical amplification type resist having low nano- edge roughness. SOLUTION: The radiation sensitive resin composition contains (A) a radiation sensitive acid generating agent selected from the group comprising compounds of formulae (1) and (2) (where R1 and R2 are each alkyl, fluoroalkyl or aryl which may be substituted by fluorine) and (B) a copolymer of an acetal group-containing styrene derivative typified by p-(1-ethoxyethoxy)styrene and p-hydroxystyrene.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention is particularly useful for microfabrication using various radiations such as charged particles such as electron beams and X-rays, in addition to far ultraviolet rays typified by a KrF excimer laser or an ArF excimer laser. The present invention relates to a radiation-sensitive resin composition suitable as a chemically amplified resist.

[0002]

2. Description of the Related Art In the field of microfabrication represented by the manufacture of integrated circuit elements, the processing size in lithography has been reduced in order to obtain a higher degree of integration. There is a need for a technique capable of performing fine processing with good reproducibility. Therefore, even in resists used for fine processing, 0.5 μm
It is necessary to form the following patterns with high precision. However, in the conventional method using visible light (wavelength 800 to 400 nm) or near ultraviolet light (wavelength 400 to 300 nm), a fine pattern of 0.5 μm or less can be formed with high precision. It is extremely difficult to form. Therefore, a shorter wavelength (wavelength 3
The use of radiation (less than 00 nm) is being studied earnestly.
Examples of such short-wavelength radiation include charged particle beams such as far-infrared rays and electron beams typified by a bright line spectrum of a mercury lamp (wavelength: 254 nm), a KrF excimer laser (wavelength: 248 nm) or an ArF excimer laser (wavelength: 193 nm). And X-rays such as synchrotron radiation. Of these, lithography using an excimer laser has been particularly noted because of its high output and high efficiency characteristics. For this reason, resists used for lithography are required to be able to form fine patterns of 0.5 μm or less with high sensitivity, high resolution, and good reproducibility by excimer laser. As a resist suitable for deep ultraviolet rays such as excimer laser, a radiation-sensitive acid generator that generates an acid by irradiation with radiation (hereinafter referred to as “exposure”) is used, and the sensitivity of the resist is increased by the catalytic action of the acid. An improved “chemically amplified resist” has been proposed.

[0003] As such a chemically amplified resist,
For example, JP-A-59-45439 discloses a combination of a resin protected with a t-butyl group or a t-butoxycarbonyl group with a radiation-sensitive acid generator.
JP-A-5-2845 discloses a combination of a resin protected with a silyl group and a radiation-sensitive acid generator. In addition, there have been many reports on chemically amplified resists such as resists containing a resin protected with an acetal group or a ketal group and a radiation-sensitive acid generator (Japanese Patent Laid-Open No. 25850/1990). I have. Among these chemically amplified resists, in particular, chemically amplified resists using a resin having an acetal group or a ketal group have attracted attention because of their high resolution performance (for example, Proc. SPIE Vol. 3049, See p314). However, when the device design dimension becomes sub-half micron or less and line width control needs to be performed more precisely, resolution performance alone is not sufficient, and the smoothness of the film surface after resist pattern formation is insufficient. Being better is also important. When a chemically amplified resist having poor film surface smoothness is used, when a resist pattern is transferred to a substrate by a process such as etching, the unevenness of the film surface (so-called nano-edge roughness) is transferred to the substrate, and the dimensions are reduced. Accuracy will be reduced and ultimately the electrical properties of the device will be impaired (eg, J. Photopolym. Sci. Tech. P571,1998; P.
roc. SPIE Vol. 3333, p313; Proc. SPIE Vol. 3333, p6
34; see J. Vac. Sci. Technol. B16 (1), 1998, p69)
. Therefore, there has been a strong demand for the development of a chemically amplified resist having excellent resolution performance and small nano edge roughness.

[0004]

SUMMARY OF THE INVENTION In view of the situation in the prior art, it is an object of the present invention to provide various types of radiation, in particular, K radiation.
High sensitivity (low exposure energy), excellent resolution performance, and nano-edge against far ultraviolet rays represented by rF excimer laser, ArF excimer laser or F ₂ excimer laser, and charged particle beams such as electron beams An object of the present invention is to provide a radiation-sensitive resin composition that can be suitably used as a chemically amplified resist having a small roughness.

[0005]

According to the present invention, the above object is achieved by (A) at least one compound selected from the group consisting of a compound represented by the following formula (1) and a compound represented by the following formula (2): Radiation-sensitive acid generator consisting of

[0006]

Embedded image [In the formula (1), R ¹ is a linear group having 1 to 10 carbon atoms;
It represents a branched or cyclic alkyl group, a linear, branched or cyclic fluoroalkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 11 carbon atoms which may be substituted by fluorine. ]

[0007]

Embedded image [In the formula (2), R ² is a linear group having 1 to 10 carbon atoms;
It represents a branched or cyclic alkyl group, a linear, branched or cyclic fluoroalkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 11 carbon atoms which may be substituted by fluorine. ]

And (B) a resin having a repeating unit represented by the following formula (3) and a repeating unit represented by the following formula (4):

[0009]

Embedded image [In the formula (3), R ³ represents a methyl group or an ethyl group, and R ⁴ represents a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms. ]

[0010]

Embedded image Is achieved by a radiation-sensitive resin composition characterized by containing:

Hereinafter, the present invention will be described in detail. Acid generator (A) The component (A) in the present invention includes a compound represented by the formula (1) (hereinafter, referred to as “compound (1)”) and a compound represented by the formula (2) (hereinafter, referred to as “compound (1)”). , "Compound (2)") and at least one radiation-sensitive acid generator (hereinafter, referred to as "acid generator (A)").
It is.

In the formulas (1) and (2), examples of the linear, branched or cyclic alkyl group having 1 to 10 carbon atoms for R ¹ and R ² include a methyl group, an ethyl group and an n-type alkyl group. Propyl group, i-propyl group, n-butyl group,
i-butyl group, sec-butyl group, t-butyl group, n-
Pentyl group, neopentyl group, 2-methyl-1-butyl group, 2-methyl-2-butyl group, n-hexyl group, n-
Heptyl group, n-octyl group, 2-ethylhexyl group,
Examples thereof include an n-nonyl group, an n-decyl group, a cyclopentyl group, and a cyclohexyl group.

Examples of the linear, branched or cyclic fluoroalkyl group having 1 to 10 carbon atoms for R ¹ and R ² include, for example, fluoromethyl group, difluoromethyl group, trifluoromethyl group and pentafluoroethyl group. Group,
Heptafluoro-n-propyl group, heptafluoro-i
-Propyl group, nonafluoro-n-butyl group, nonafluoro-i-butyl group, nonafluoro-sec-butyl group, nonafluoro-t-butyl group, perfluoro-n-
Hexyl group, perfluoro-n-octyl group, perfluoro-n-decyl group, perfluorocyclopentyl group,
Perfluorocyclohexyl groups and the like can be mentioned.

Examples of the aryl group having 6 to 11 carbon atoms which may be substituted by fluorine for R ¹ and R ² include, for example, phenyl group, o-methylphenyl group, m-methylphenyl group, p-methylphenyl And unsubstituted aryl groups such as a group, p-ethylphenyl group, 1-naphthyl group and 2-naphthyl group, and fluorine-substituted products of these groups.

In the formulas (1) and (2), R ¹ and R ² are methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-
-Butyl group and the like are preferred, and particularly preferred are an n-propyl group and an i-propyl group.

In the present invention, the acid generator (A) can be used alone or in combination of two or more.
As one embodiment of the present invention, by using a mixture of the compound (1) and the compound (2), the footing of the resist pattern can be extremely suppressed even on a basic substrate such as silicon nitride or titanium nitride. It has been found that a resist pattern having a particularly excellent pattern shape can be formed.

Other Acid Generator In the present invention, a radiation-sensitive acid generator other than the acid generator (hereinafter referred to as "other acid generator") may be used together with the acid generator (A). Can be used together. Examples of other acid generators include onium salt compounds, sulfone compounds, sulfonic acid ester compounds, sulfonimide compounds, diazomethane compounds, and the like. Hereinafter, these other acid generators will be described.

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. As a specific example of the onium salt compound, bis (pt
-Butylphenyl) iodonium trifluoromethanesulfonate, bis (pt-butylphenyl) iodonium nonafluoro-n-butanesulfonate, bis (p
-T-butylphenyl) iodonium o-trifluoromethylbenzenesulfonate, bis (pt-butylphenyl) iodonium p-trifluoromethylbenzenesulfonate, bis (pt-butylphenyl) iodonium 10-camphor-sulfonate, bis (Pt-
Butylphenyl) iodonium p-toluenesulfonate, bis (pt-butylphenyl) iodonium pyrene sulfonate, bis (pt-butylphenyl) iodonium n-dodecylbenzenesulfonate, bis (p
-T-butylphenyl) iodonium benzenesulfonate, bis (pt-butylphenyl) iodonium 2,4-difluorobenzenesulfonate, bis (p-
t-butylphenyl) iodonium n-octanesulfonate, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-n
-Butanesulfonate, diphenyliodonium o-trifluoromethylbenzenesulfonate, diphenyliodonium p-trifluoromethylbenzenesulfonate, diphenyliodonium 10-camphor-sulfonate, diphenyliodonium p-toluenesulfonate, diphenyliodonium pyrene sulfonate, diphenyliodonium n-dodecylbenzene Sulfonate, diphenyliodonium benzenesulfonate, diphenyliodonium 2,4-difluorobenzenesulfonate, diphenyliodonium n-octanesulfonate,

Triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium nonafluoro-n-butanesulfonate, triphenylsulfonium o-trifluoromethylbenzenesulfonate, triphenylsulfonium p-trifluoromethylbenzenesulfonate, triphenylsulfonium 10-camphor Sulfonate, triphenylsulfonium p-toluenesulfonate, triphenylsulfonium pyrene sulfonate, triphenylsulfonium n-dodecylbenzenesulfonate, triphenylsulfoniumbenzenesulfonate, triphenylsulfonium 2,4-
Difluorobenzenesulfonate, triphenylsulfonium n-octanesulfonate, pt-butylphenyldiphenylsulfonium trifluoromethanesulfonate, pt-butylphenyldiphenylsulfonium nonafluoro-n-butanesulfonate, pt-butylphenyldiphenylsulfonium o- Trifluoromethylbenzenesulfonate, pt-butylphenyldiphenylsulfonium p-trifluoromethylbenzenesulfonate, pt-butylphenyldiphenylsulfonium 10-camphor-sulfonate, pt-butylphenyldiphenylsulfonium p-toluenesulfonate, p -T-butylphenyldiphenylsulfonium pyrene sulfonate, pt-butylphenyldiphenylsulfonium n- dodecyl benzene sulfonate, p-t-butylphenyl diphenyl sulfonium benzenesulfonate, p-t-butylphenyl diphenyl sulfonium 2,4-difluoro benzenesulfonate, p-t-butylphenyl diphenyl sulfonium n
-Octane sulfonate,

Pt-butoxyphenyldiphenylsulfonium trifluoromethanesulfonate, pt-butoxyphenyldiphenylsulfonium nonafluoro-
n-butanesulfonate, pt-butoxyphenyldiphenylsulfonium o-trifluoromethylbenzenesulfonate, pt-butoxyphenylphenyldiphenylsulfonium p-trifluoromethylbenzenesulfonate, pt-butoxyphenyldiphenylsulfonium 10-camphor Sulfonate, pt-butoxyphenyldiphenylsulfonium p-toluenesulfonate, pt-butoxyphenyldiphenylsulfonium pyrene sulfonate, pt-butoxyphenyldiphenylsulfonium n-dodecylbenzenesulfonate, pt-butoxyphenyldiphenylsulfoniumbenzenesulfonate Pt-butoxyphenyldiphenylsulfonium 2,4-difluorobenzenesulfonate, pt Butoxyphenyl diphenylsulfonium n- octane sulfonate, and the like.

Sulfone compounds Examples of the sulfone compound include β-ketosulfone,
β-sulfonyl sulfone and the like can be mentioned. Specific examples of the sulfone compound include phenacylphenylsulfone, mesitylphenacylsulfone, bis (phenylsulfonyl) methane, 1,1-bis (phenylsulfonyl) cyclopentane, 1,1-bis (phenylsulfonyl) cyclohexane, -Trisphenacyl sulfone and the like. 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 n-octanesulfonate, α-methylol benzoin n-dodecane sulfonate, α-methylol benzoin trifluoromethane sulfonate and the like. Sulfonimide compound As the sulfonimide compound, for example, the following formula (5)
Can be mentioned.

[0022]

Embedded image [In the formula (5), X represents a divalent group such as an alkylene group, an arylene group, or an alkoxylene group, and R ⁵ represents a monovalent group such as an alkyl group, an aryl group, a halogen-substituted alkyl group, or a halogen-substituted aryl group. Represents a 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- (10-camphorsulfonyloxy) succinimide, N- (10
-Camphorsulfonyloxy) phthalimide, N-
(10-camphorsulfonyloxy) diphenylmaleimide, N- (10-camphorsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (10-camphorsulfonyloxy) -7-oxabicyclo [2.2.1] hept-5-
Ene-2,3-dicarboximide, N- (10-camphorsulfonyloxy) bicyclo [2.2.1] heptane-5,6-oxy-2,3-dicarboximide, N-
(10-camphorsulfonyloxy) naphthylimide,

N- (p-methylphenylsulfonyloxy) succinimide, N- (p-methylphenylsulfonyloxy) phthalimide, N- (p-methylphenylsulfonyloxy) diphenylmaleimide, N- (p-
Methylphenylsulfonyloxy) bicyclo [2.2.
1] Hept-5-ene-2,3-dicarboximide, N
-(P-methylphenylsulfonyloxy) -7-oxabicyclo [2.2.1] hept-5-ene-2,3-
Dicarboximide, N- (p-methylphenylsulfonyloxy) bicyclo [2.2.1] heptane-5,6-
Oxy-2,3-dicarboximide, N- (p-methylphenylsulfonyloxy) naphthylimide, N- (o
-Trifluoromethylphenylsulfonyloxy) succinimide, N- (o-trifluoromethylphenylsulfonyloxy) phthalimide, N- (o-trifluoromethylphenylsulfonyloxy) diphenylmaleimide, N- (o-trifluoromethylphenylsulfonyloxy) ) Bicyclo [2.2.1] hept-5-ene-
2,3-dicarboximide, N- (o-trifluoromethylphenylsulfonyloxy) -7-oxabicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (o -Trifluoromethylphenylsulfonyloxy) bicyclo [2.2.1] heptane-5,6
-Oxy-2,3-dicarboximide, N- (o-trifluoromethylphenylsulfonyloxy) naphthylimide,

N- (p-fluorophenylsulfonyloxy) succinimide, N- (p-fluorophenylsulfonyloxy) phthalimide, N- (p-fluorophenylsulfonyloxy) diphenylmaleimide, N- (p-fluorophenylsulfonyloxy) diphenylmaleimide
(P-fluorophenylsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (p-fluorophenylsulfonyloxy) -7-oxabicyclo [2.2. 1] Hept-5-
Ene-2,3-dicarboximide, N- (p-fluorophenylsulfonyloxy) bicyclo [2.2.1] heptane-5,6-oxy-2,3-dicarboximide,
N- (p-fluorophenylsulfonyloxy) naphthylimide and the like can be mentioned.

Diazomethane Compound Examples of the diazomethane compound include compounds represented by the following formula (6).

[0027]

Embedded image [In the formula (6), R ⁶ and R ⁷ are each independently a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, and an optionally substituted carbon atom having 6 carbon atoms. ~ 20 aryl groups, optionally substituted carbon atoms 7
And the other monovalent organic group having 1 to 20 carbon atoms and having an aralkyl group of 20 to 20 or a hetero atom. ]

Specific examples of the diazomethane compound include bis (trifluoromethylsulfonyl) diazomethane, bis (t-butylsulfonyl) diazomethane, bis (cyclohexylsulfonyl) diazomethane, bis (phenylsulfonyl) diazomethane, and bis (p-methylphenylsulfonyl) ) Diazomethane, bis (1,4-dioxaspiro [4.5] decane-7-sulfonyl) diazomethane, bis (1,5-dioxaspiro [5.5] undecane-8-sulfonyl) diazomethane, bis (3,3-dimethyl) -1,5-dioxaspiro [5.5] undecane-8-sulfonyl) diazomethane, methylsulfonyl.
Cyclohexylsulfonyldiazomethane, methylsulfonyl / phenylsulfonyldiazomethane, methylsulfonyl / p-methylphenylsulfonyldiazomethane, t
-Butylsulfonyl / cyclohexylsulfonyldiazomethane, t-butylsulfonyl / phenylsulfonyldiazomethane, t-butylsulfonyl / p-methylphenylsulfonyldiazomethane, cyclohexylsulfonyl / 1,4-dioxaspiro [4.5] decane-7-sulfonyldiazomethane, cyclohexyl Sulfonyl ・ 1,
5-dioxaspiro [5.5] undecane-8-sulfonyldiazomethane, cyclohexylsulfonyl-3,3
-Dimethyl-1,5-dioxaspiro [5.5] undecane-8-sulfonyldiazomethane. These other acid generators can be used alone or in combination of two or more.

Resin (B) The component (B) in the present invention is represented by the repeating unit represented by the above formula (3) (hereinafter referred to as “repeating unit (3)”) and the above formula (4). A resin having a repeating unit (hereinafter, referred to as “repeating unit (4)”) (hereinafter, referred to as “resin (B)”).

In the formula (3), examples of the linear, branched or cyclic alkyl group having 1 to 6 carbon atoms for R ⁴ include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group, n-pentyl group, neopentyl group,
Examples thereof include an n-hexyl group, a cyclopentyl group, and a cyclohexyl group. R ⁴ in the formula (3) is preferably a methyl group, an ethyl group, a cyclohexyl group, or the like. Further, as R ³ in the formula (3), both a methyl group and an ethyl group are preferable. Group in formula (3)
OCH (R ³ ) (OR ⁴ ) forms an acetal structure together with the benzene ring in the formula (3), and the acetal structure has an acid dissociating property that dissociates by the action of an acid. is there.

Specific examples of the repeating unit (3) include p-
(1-methoxyethoxy) styrene, p- (1-ethoxyethoxy) styrene, p- (1-n-propoxyethoxy) styrene, p- (1-i-propoxyethoxy)
Styrene, p- (1-n-butoxyethoxy) styrene, p- (1-t-butoxyethoxy) styrene, p-
(1-n-pentyloxyethoxy) styrene, p-
(1-neopentyloxyethoxy) styrene, p-
(1-n-hexyloxyethoxy) styrene, p-
(1-cyclopentyloxyethoxy) styrene, p-
(1-cyclohexyloxyethoxy) styrene, p-
(1-methoxypropoxy) styrene, p- (1-ethoxypropoxy) styrene, p- (1-n-propoxypropoxy) styrene, p- (1-i-propoxypropoxy) styrene, p- (1-n-butoxy) Propoxy) styrene, p- (1-tert-butoxypropoxy) styrene, p- (1-n-pentyloxypropoxy) styrene, p- (1-neopentyloxypropoxy) styrene, p- (1-n-hexyloxy) Propoxy) styrene, p- (1-cyclopentyloxypropoxy)
Examples thereof include units in which polymerizable unsaturated bonds such as styrene and p- (1-cyclohexyloxypropoxy) styrene have been cleaved.

Of these repeating units (3), p-
(1-methoxyethoxy) styrene, p- (1-ethoxyethoxy) styrene, p- (1-methoxypropoxy) styrene, p- (1-ethoxypropoxy) styrene, p- (1-cyclohexyloxyethoxy) styrene and the like A unit in which a polymerizable unsaturated bond is cleaved is preferable. In the resin (B), the repeating unit (3) may be present alone or in combination of two or more.

The resin (B) may further have another repeating unit, if necessary, or may have a structure partially crosslinked with a suitable crosslinking group (for example, a crosslinking group having a diethylene glycol skeleton). . Examples of the other repeating unit include styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, o-methoxystyrene, m-methoxystyrene, p-methoxystyrene, and pt. -Butoxystyrene, pt-butoxycarbonyloxystyrene, p
-T-butoxycarbonylmethyloxystyrene, p-
(2-t-butoxycarbonylethyloxy) styrene, o-hydroxystyrene, m-hydroxystyrene, 3,4-dihydroxystyrene, p-hydroxy-
vinyl aromatic compounds such as α-methylstyrene, p-acetoxystyrene, p-tetrahydrofuranyloxystyrene, p-tetrahydropyranyloxystyrene;

Methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, i-propyl (meth) acrylate, n- (meth) acrylate
Butyl, i-butyl (meth) acrylate, sec-butyl (meth) acrylate, t-butyl (meth) acrylate, n-pentyl (meth) acrylate, neopentyl (meth) acrylate, (meth) acrylic acid n-hexyl,
2-ethylhexyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2- (meth) acrylate
Hydroxypropyl, 3-hydroxypropyl (meth) acrylate, cyclopentyl (meth) acrylate, 1-methylcyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, 1-methylcyclohexyl (meth) acrylate, (meth) Norbornyl acrylate,
Isobornyl (meth) acrylate, tricyclodecanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, adamantyl (meth) acrylate, 2-adamantyl-2-methyl (meth) acrylate, (meth) acryl 2-adamantyl-2-ethyl acrylate, tetrahydrofuranyl (meth) acrylate, tetrahydropyranyl (meth) acrylate, phenyl (meth) acrylate, benzyl (meth) acrylate, phenethyl (meth) acrylate, (meth) (Dimethyl) acrylate (p-methylcyclohexyl) methyl, (meth) acrylic acid (dimethyl)
(Meth) acrylates such as (norbornyl) methyl and (dimethyl) (phenyl) methyl (meth) acrylate;

Unsaturated carboxylic acids such as (meth) acrylic acid, crotonic acid, maleic acid, maleic anhydride, fumaric acid, cinnamic acid and the like, and acid anhydrides; 2-carboxyethyl (meth) acrylate; ) Carboxyalkyl esters of unsaturated carboxylic acids such as 2-carboxypropyl acrylate and 3-carboxypropyl (meth) acrylate; unsaturated such as (meth) acrylonitrile, α-chloroacrylonitrile, crotonnitrile, maleinitrile, fumaronitrile, etc. Nitrile compounds; (meth) acrylamide, N, N-dimethyl (meth) acrylamide,
Unsaturated amide compounds such as crotonamide, maleamide, fumaramide and the like; unsaturated imide compounds such as maleimide, N-phenylmaleimide and N-cyclohexylmaleimide; N-vinyl-ε-caprolactam, N-vinylpyrrolidone, 2-vinylpyridine, 3-vinylpyridine,
Examples thereof include units in which a polymerizable unsaturated bond has been cleaved, such as other nitrogen-containing vinyl compounds such as 4-vinylpyridine, 2-vinylimidazole, and 4-vinylimidazole.

Of these other repeating units, styrene, α-methylstyrene, pt-butoxystyrene,
pt-butoxycarbonyloxystyrene, pt-
Butoxycarbonylmethyloxystyrene, p-acetoxystyrene, p- (2-t-butoxycarbonylethyloxy) styrene, t-butyl (meth) acrylate,
Polymerizable unsaturated bonds such as isobornyl (meth) acrylate, tricyclodecanyl (meth) acrylate, 2-adamantyl-2-methyl (meth) acrylate, and 2-adamantyl-2-ethyl (meth) acrylate Cleavage units are preferred. In the resin (B), other repeating units may be used alone or in combination of two or more.

In the resin (B), the repeating unit (3) with respect to the total number of the repeating unit (3) and the repeating unit (4)
Is the acetal structure in the repeating unit (3),
It varies depending on the type and content of other repeating units or cross-linking groups and cannot be specified unconditionally, but is preferably 5 to 9
0%, more preferably 10% to 80%. The content of other repeating units is usually 50 mol% or less, preferably 30 mol% or less, based on all repeating units. In addition, the content of the crosslinking group, with respect to all the repeating units,
Usually, it is at most 15 mol%, preferably at most 10 mol%. The weight average molecular weight in terms of polystyrene (hereinafter, referred to as “Mw”) of the resin (B) measured by gel permeation chromatography is preferably from 1,000 to 5,
00,000, more preferably 3,000-300,
000. The ratio (M) between the Mw of the resin (B) and the number average molecular weight in terms of polystyrene (hereinafter, referred to as “Mn”) measured by gel permeation chromatography.
w / Mn) is usually 1 to 5, preferably 1 to 3.

The resin (B) can be obtained by, for example, (a) converting a part of the phenolic hydroxyl group in the (co) polymer of p-hydroxystyrene to ethyl vinyl ether, n-butyl vinyl ether, cyclo (B) a part of the phenolic hydroxyl group in p-hydroxystyrene is converted to ethyl vinyl ether and n under a weakly acidic condition.
A monomer corresponding to the repeating unit (3) is synthesized by an addition reaction with a vinyl ether compound such as -butyl vinyl ether or cyclohexyl vinyl ether, and the monomer is copolymerized with p-hydroxystyrene in a conventional manner. It can be manufactured by a method or the like. The structure of the resin (B) partially cross-linked by the cross-linking group having a diethylene glycol skeleton can be obtained, for example, by simultaneously reacting an appropriate amount of diethylene glycol divinyl ether during the addition reaction with the vinyl ether compound in the method (A). Can be introduced.

Other Acid-Dissociable Group-Containing Resins In the present invention, together with the resin (B), an acid-dissociable group-containing resin other than the resin (hereinafter referred to as “another acid-dissociable group-containing resin”)
That. ) Can also be used in combination. Hereinafter, another resin having an acid dissociable group will be described. The other acid-dissociable group-containing resin is an alkali-insoluble or alkali-insoluble resin protected by an acid-dissociable group, and is a resin which becomes alkali-soluble when the acid-dissociable group is dissociated. The term “alkali-insoluble or poorly alkali-soluble” used herein is employed when a resist pattern is formed from a resist film formed using a radiation-sensitive resin composition containing another acid-labile group-containing resin. When a film is developed using only the resin instead of the resist film under alkaline development conditions, 50% or more of the initial film thickness of the film remains after development.

As the other acid-dissociable group-containing resin, for example, an alkali-soluble resin having at least one kind of acidic functional group such as a phenolic hydroxyl group and a carboxyl group, such as those represented by the following formulas (7) to (9), Having a structure in which a hydrogen atom of an acidic functional group in an alkali-soluble resin having one or more kinds of repeating units to be substituted with one or more acid dissociable groups capable of dissociating in the presence of an acid, as such Represents a hydrogen atom of a phenolic hydroxyl group in an alkali-insoluble or alkali-insoluble resin (hereinafter referred to as “resin (b1)”), and an alkali-soluble resin having at least one kind of a repeating unit represented by the following formula (10). Having a structure substituted with one or more acid-dissociable groups capable of dissociating in the presence of an acid, which itself is an alkali-insoluble or alkali-insoluble resin (hereinafter referred to as (B2) "that.) Can be mentioned. Hereinafter, the resin (b1) and the resin (b
2) is also collectively referred to as “resin (b)”.

[0041]

Embedded image [In the formula (7), R ⁸ represents a hydrogen atom or a methyl group, R ⁹ represents a halogen atom or a monovalent organic group having 1 to 6 carbon atoms, and n is an integer of 0 to 3. ]

[0042]

Embedded image [In the formula (8), R ¹⁰ represents a hydrogen atom or a methyl group. ]

[0043]

Embedded image

[0044]

Embedded image [In the formula (10), R ¹¹ , R ¹² , R ¹³ , R ¹⁴ and R ¹⁵ each independently represent a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms. ]

The acid dissociable group in the resin (b) includes
Examples thereof include a substituted methyl group, a 1-substituted ethyl group, a 1-substituted propyl group, a 1-branched alkyl group, a silyl group, a germyl group, an alkoxycarbonyl group, an acyl group, and a cyclic acid dissociable group. Examples of the substituted methyl group include a methoxymethyl group, a methylthiomethyl group,
Ethoxymethyl, ethylthiomethyl, methoxyethoxymethyl, benzyloxymethyl, benzylthiomethyl, phenacyl, bromophenacyl, methoxyphenacyl, methylthiophenacyl, α-methylphenacyl, cyclopropylmethyl Group, benzyl group,
Diphenylmethyl group, triphenylmethyl group, bromobenzyl group, nitrobenzyl group, methoxybenzyl group, methylthiobenzyl group, ethoxybenzyl group, ethylthiobenzyl group, piperonyl group, methoxycarbonylmethyl group, ethoxycarbonylmethyl group, n-propoxy Carbonylmethyl group, isopropoxycarbonylmethyl group,
Examples thereof include an n-butoxycarbonylmethyl group and a t-butoxycarbonylmethyl group.

The 1-substituted ethyl group includes, for example, 1-methoxyethyl group, 1-methylthioethyl group, 1,1-dimethoxyethyl group, 1-ethoxyethyl group, 1-ethylthioethyl group, 1,1-diethoxyethyl group, 1-phenoxyethyl group, 1-phenylthioethyl group, 1,1-diphenoxyethyl group, 1-benzyloxyethyl group, 1-benzylthioethyl group, 1-cyclopropylethyl group A 1-phenylethyl group, a 1,1-diphenylethyl group, a 1-methoxycarbonylethyl group,
1-ethoxycarbonylethyl group, 1-n-propoxycarbonylethyl group, 1-isopropoxycarbonylethyl group, 1-n-butoxycarbonylethyl group, 1-t
-Butoxycarbonylethyl group and the like. Further, as the 1-branched alkyl group, for example,
i-propyl group, sec-butyl group, t-butyl group,
1,1-dimethylpropyl group, 1-methylbutyl group,
Examples thereof include a 1,1-dimethylbutyl group. Examples of the 1-substituted propyl group include a 1-methoxypropyl group and a 1-ethoxypropyl group.

Examples of the silyl group include, for example, trimethylsilyl, ethyldimethylsilyl, methyldiethylsilyl, triethylsilyl, i-propyldimethylsilyl, methyldi-i-propylsilyl, tri-i-propyl Examples thereof include a silyl group, a t-butyldimethylsilyl group, a methyldi-t-butylsilyl group, a tri-t-butylsilyl group, a phenyldimethylsilyl group, a methyldiphenylsilyl group, and a triphenylsilyl group. Examples of the germyl group include a trimethylgermyl group, an ethyldimethylgermyl group, a methyldiethylgermyl group, a triethylgermyl group, an i-propyldimethylgermyl group, a methyldi-i-propylgermyl group, and a trimethylgermyl group. -I-propylgermyl group, t-butyldimethylgermyl group, methyldi-t-butylgermyl group, tri-t-butylgermyl group, phenyldimethylgermyl group, methyldiphenylgermyl group, triphenylgermyl group and the like. be able to. Further, as the alkoxycarbonyl group, for example, a methoxycarbonyl group,
An ethoxycarbonyl group, an i-propoxycarbonyl group,
and a t-butoxycarbonyl group.

Examples of the acyl group include acetyl, propionyl, butyryl, heptanoyl, hexanoyl, valeryl, pivaloyl, isovaleryl, laurylyl, myristoyl, palmitoyl, stearoyl, oxalyl. Group, malonyl group, succinyl group, glutaryl group, adipoyl group, piperoyl group, suberoyl group, azelaoil group, sebacoil group, acryloyl group, propioloyl group, methacryloyl group, crotonoyl group, oleoyl group, maleoyl group,
Fumaroyl group, mesaconoyl group, camphoroyl group, benzoyl group, phthaloyl group, isophthaloyl group, terephthaloyl group, naphthoyl group, toluoyl group, hydroatropoyl group, atropoyl group, cinnamoyl group, furoyl group, tenoyl group, nicotinoyl group, isonicotinoyl group , P-toluenesulfonyl group, mesyl group and the like. Further, as the cyclic acid dissociable group, for example, cyclopropyl group, cyclopentyl group, cyclohexyl group, cyclohexenyl group, p-methoxycyclohexyl group, tetrahydropyranyl group, tetrahydrofuranyl group, tetrahydrothiopyranyl group, tetrahydro Thiofuranyl group, 3-bromotetrahydropyranyl group, 4
-Methoxytetrahydropyranyl group, 4-methoxytetrahydrothiopyranyl group, 3-tetrahydrothiophen-1,1-dioxide group and the like.

Of these acid dissociable groups, t-butyl, 1-methoxymethyl, 1-methoxyethyl, 1
-Ethoxyethyl, 1-ethoxypropyl, 1-propoxyethyl, trimethylsilyl, t-butoxycarbonyl, t-butoxycarbonylmethyl, tetrahydropyranyl, tetrahydrofuranyl and the like are preferred.

The rate of introduction of acid-dissociable groups in the resin (b) (the ratio of the number of acid-dissociable groups to the total number of acidic functional groups and acid-dissociable groups in the resin (b)) is Although it cannot be specified unconditionally depending on the type of the group or the alkali-soluble resin into which the group is introduced, it is preferably from 10 to 100%, more preferably from 15 to 100%.

The Mw of the resin (b) is preferably 1,00
0 to 150,000, more preferably 3,000 to 1
00,000. Further, Mw / Mn of the resin (b)
Is usually 1 to 5, preferably 1 to 3 . The resin (b) can be produced, for example, by introducing one or more acid-dissociable groups into a previously produced alkali-soluble resin, and the resin (b1) can be one or more kinds having an acid-dissociable group. Can be produced by (co) polymerizing the polymerizable unsaturated monomer of (a), and the resin (b2) further comprises (co) polycondensation of one or more polycondensation components having an acid dissociable group. Can be manufactured by In the present invention, other acid-dissociable group-containing resins can be used alone or in combination of two or more.

Other Additives The radiation-sensitive resin composition of the present invention contains an acid generator (A) and a resin (B) as essential components, and may optionally contain other acid generators and other acid dissociable compounds. Although it further contains a group-containing resin, it may further contain other additives such as a dissolution controlling agent, an acid diffusion controlling agent, a surfactant and a sensitizer, if necessary.

-Solubility controlling agent- As a solubility controlling agent, for example, a phenolic hydroxyl group,
A compound having an acidic functional group such as a carboxyl group, and at least one substituent capable of dissociating a hydrogen atom of the acidic functional group in the compound in the presence of an acid (hereinafter, referred to as an “acid dissociable substituent”). Substituted compounds and the like can be mentioned. Examples of the acid dissociable substituent include, for example, a substituted methyl group, a 1-substituted ethyl group, a 1-substituted n-propyl group, a 1-branched alkyl group exemplified for the acid dissociable group-containing resin,
Examples thereof include groups similar to acid dissociable groups such as a silyl group, a germyl group, an alkoxycarbonyl group, an acyl group, and a cyclic acid dissociable group. The solubility controlling agent may be a low molecular weight compound or a high molecular weight compound. Specific examples of the low molecular weight compound include compounds represented by the following formulas (11) to (15).

[0054]

Embedded image [In the formula (11), R ¹⁶ represents a hydrogen atom or an acid-dissociable substituent, and a plurality of R ¹⁶ may be the same or different from each other, and R ¹⁷ may be a straight or branched chain having 1 to 4 carbon atoms. A plurality of R ^{17 s} may be the same or different, p is an integer of 1 or more, q is an integer of 0 or more, and p + q ≦
Meet 6. ]

[0055]

Embedded image

[In the formula (12), R ¹⁶ and R ¹⁷ have the same meanings as in the formula (11), and A represents a single bond, -O-, -S
-, - CO -, - COO -, - SO -, - SO 2 -, -
C (R ¹⁸ ) (R ¹⁹ )-(where R ¹⁸ and R ¹⁹ are each independently a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms, Represents an acyl group, a phenyl group or a 1-naphthyl group) or a group represented by the following formula:

[0057]

Embedded image

(Where R ¹⁷ is the same as above, and x is 0)
-4. ), P, q, r and s are each an integer of 0 or more, and p + q ≦ 5, r + s ≦ 5, p +
Satisfies r ≧ 1. ]

[0059]

Embedded image [In the formula (13), R ¹⁶ and R ¹⁷ have the same meaning as in the formula (11), and R ²⁰ represents a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms or a phenyl group,
p, q, r, s, t and u are each an integer of 0 or more, and p + q ≦ 5, r + s ≦ 5, t + u ≦ 5, p + r + t
Satisfies ≧ 1. ]

[0060]

Embedded image [In the formula (14), R ¹⁶ and R ¹⁷ have the same meaning as the formula (11), A has the same meaning as the formula (12), R ²⁰ has the same meaning as the formula (13), and a plurality of R ²⁰ May be the same or different from each other, and p, q, r, s, t, u, v, and w are each an integer of 0 or more, and p + q ≦ 5, r + s ≦
5, t + u ≦ 5, v + w ≦ 5, and p + r + t + v ≧ 1. ]

[0061]

Embedded image [In the formula (15), R ¹⁶ and R ¹⁷ have the same meaning as in the formula (11), R ²⁰ has the same meaning as in the formula (13), and a plurality of R ²⁰ may be mutually the same or different; , Q,
r, s, t, u, v and w are each an integer of 0 or more, and p + q ≦ 5, r + s ≦ 5, t + u ≦ 5, v + w ≦
4. Satisfies p + r + t + v ≧ 1. These dissolution controlling agents can be used alone or in combination of two or more.

-Acid Diffusion Control Agent-The acid diffusion control agent controls the diffusion phenomenon of the acid generated from the acid generator (A) or the like by exposure in the resist film,
This has an effect of suppressing an undesired chemical reaction in the unexposed area, and the like. By using such an acid diffusion controller, the storage stability of the composition is improved, the resolution as a resist is further improved, and the fluctuation of the retention time (PED) from exposure to development is improved. The change in the line width of the resist pattern due to the above can be suppressed, and the process stability becomes extremely excellent.

As the acid diffusion controller, for example, a compound represented by the following formula (16) (hereinafter referred to as “nitrogen-containing compound (i)”):

[0064]

Embedded image [In the formula (16), each R ²¹ independently represents a hydrogen atom, an optionally substituted alkyl group, an optionally substituted aryl group, or an optionally substituted aralkyl group. ]

A diamino compound having two nitrogen atoms in the same molecule (hereinafter referred to as “nitrogen-containing compound (ii)”) and a polymer having three or more nitrogen atoms (hereinafter referred to as “nitrogen-containing compound (iii)”) "), A low molecular weight compound in which at least one of the hydrogen atoms of a compound having at least one amino group in which at least one hydrogen atom is bonded to a nitrogen atom is substituted with a t-butoxycarbonyl group (hereinafter, referred to as" Nitrogen-containing compound (iv) "), an amide group-containing compound, a urea compound, a nitrogen-containing heterocyclic compound, and the like.

Examples of the nitrogen-containing compound (i) include, for example, n
Linear, branched or cyclic monoalkylamines such as -hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine, n-dodecylamine and cyclhexylamine; di-n- Butylamine, di-n-pentylamine, di-n-hexylamine, di-n-heptylamine, di-n-octylamine, di-n-nonylamine, di-n-decylamine, methyl n-dodecylamine, -N-dodecylamine,
Linear, branched or cyclic dialkylamines such as methyl / cyclohexylamine and dicyclohexylamine; triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine , Tri-n-heptylamine,
Tri-n-octylamine, tri-n-nonylamine,
Linear, branched or cyclic trialkyl such as tri-n-decylamine, n-dodecyldimethylamine, methyldi-n-dodecylamine, tri-n-dodecylamine, cyclohexyldimethylamine, methyldicyclohexylamine, tricyclohexylamine Amines; alkanolamines such as ethanolamine, diethanolamine and triethanolamine; aniline, N-methylaniline, N, N-dimethylaniline, o-methylaniline, m-methylaniline, p-methylaniline, p
-Nitroaniline, methylphenylamine, diphenylamine, phenyldimethylamine, methyldiphenylamine, triphenylamine, 1-naphthylamine, 2
And aromatic amines such as naphthylamine.

Examples of the nitrogen-containing compound (ii) include ethylenediamine, N, N, N ', N'-tetramethylethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4'-diaminodiphenylmethane,
4,4′-diaminodiphenyl ether, 4,4′-diaminobenzophenone, 4,4′-diaminodiphenylamine, N, N, N ′, N′-tetrakis (2-hydroxyethyl) ethylenediamine, N, N, N ′, N′-tetrakis (2-hydroxypropyl) ethylenediamine,
2,2-bis (p-aminophenyl) propane, 2-
(M-aminophenyl) -2- (p-aminophenyl)
Propane, 2- (p-aminophenyl) -2- (m-hydroxyphenyl) propane, 2- (p-aminophenyl) -2- (p-hydroxyphenyl) propane, 1,
4-bis [1- (p-aminophenyl) -1-methylethyl] benzene, 1,3-bis [1- (p-aminophenyl) -1-methylethyl] benzene, bis (2-dimethylaminoethyl) Ether and bis (2-diethylaminoethyl) ether can be exemplified. Examples of the nitrogen-containing compound (iii) include polymers of polyethyleneimine, polyallylamine, and dimethylaminoethylacrylamide.

Examples of the nitrogen-containing compound (iv) include N
-T-butoxycarbonyldi-n-octylamine, N
Linear, branched or cyclic dialkylamine derivatives such as -t-butoxycarbonyldicyclohexylamine; Nt-butoxycarbonyl-1-adamantylamine, Nt-butoxycarbonyl-N-methyl-1-
Adamantylamine derivatives such as adamantylamine, N, N-di-t-butoxycarbonyl-1-adamantylamine; Nt-butoxycarbonyl-4,4′-diaminodiphenylmethane, N, N′-di-t-butoxy Carbonyl-4,4'-diaminodiphenylmethane,
N, N'-di-t-butoxycarbonylhexamethylenediamine, N, N, N'N'-tetra-tert-butoxycarbonylhexamethylenediamine, N, N'-di-t-
Butoxycarbonyl-1,7-diamino-n-heptane, N, N′-di-tert-butoxycarbonyl-1,8-
Diamino-n-octane, N, N′-di-tert-butoxycarbonyl-1,10-diamino-n-decane,
Other diamine derivatives such as N'-di-t-butoxycarbonyl-1,12-diamino-n-dodecane; Nt-
Butoxycarbonylbenzimidazole, Nt-butoxycarbonyl-2-methylbenzimidazole, N-
Examples thereof include imidazole derivatives such as t-butoxycarbonyl-2-phenylbenzimidazole.

Examples of the amide group-containing compound include formamide, N-methylformamide, N, N-
Examples thereof include dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, propionamide, benzamide, pyrrolidone, and N-methylpyrrolidone. Examples of the urea compound include urea, methylurea, 1,1-dimethylurea, 1,3-dimethylurea, 1,1,3,3-tetramethylurea, 1,3-diphenylurea, and tri-n
-Butylthiourea and the like. As the nitrogen-containing heterocyclic compound, for example, imidazole, 4-
Methylimidazole, 2-phenylimidazole, 4-
Imidazoles such as methyl-2-phenylimidazole, benzimidazole, 2-phenylbenzimidazole; pyridine, 2-methylpyridine, 4-methylpyridine, 2-ethylpyridine, 4-ethylpyridine, 2-phenylpyridine, 4-phenyl Pyridine, 2-methyl-
4-phenylpyridine, 2-benzylpyridine, 4-benzylpyridine, 2,6-dimethanolpyridine, nicotine, nicotinic acid, nicotinamide, quinoline, 8-
Oxyquinoline, pyridines such as acridine, pyrazine, pyrazole, pyridazine, quinosaline, purine, pyrrolidine, piperidine, 1-piperidineethanol, morpholine, 4-methylmorpholine, piperazine,
1,4-dimethylpiperazine, 1,4-diazabicyclo
[2.2.2] Octane and the like can be mentioned.

Among these nitrogen-containing organic compounds, a nitrogen-containing compound (i), a nitrogen-containing compound (iv), and a nitrogen-containing heterocyclic compound are preferable. Among the nitrogen-containing compounds (i), trialkylamines and Alkanolamines are particularly preferred, among the nitrogen-containing compounds (iv), dialkylamine derivatives and imidazole derivatives are particularly preferred, and among nitrogen-containing heterocyclic compounds, imidazoles and pyridines are particularly preferred. The acid diffusion controllers can be used alone or in combination of two or more.

-Surfactant- The surfactant has an effect of improving the coating property, striation, developability, etc. of the radiation-sensitive resin composition. As such a surfactant, any of anionic, cationic, nonionic and amphoteric surfactants can be used, but a preferred surfactant is a nonionic surfactant. Examples of the nonionic surfactant include polyoxyethylene higher alkyl ethers, polyoxyethylene higher alkyl phenyl ethers, higher fatty acid diesters of polyethylene glycol, and the like, and KP (Shin-Etsu Chemical Co., Ltd.) ), Polyflow (manufactured by Kyoeisha Yushi Kagaku Kogyo), F-Top (manufactured by Tochem Products), Megafac (manufactured by Dainippon Ink and Chemicals), Florard (manufactured by Sumitomo 3M), Asahi Guard, Surflon (manufactured by Asahi Glass), etc. Can be mentioned. These surfactants can be used alone or in combination of two or more.

-Sensitizers and the like- A sensitizer absorbs radiation energy and transmits the energy to a radiation-sensitive acid-forming agent to increase the amount of acid produced, thereby increasing the radiation-sensitive resin. It has the effect of improving the apparent sensitivity of the composition. Examples of such sensitizers include acetophenones, benzophenones, naphthalenes, biacetyl, eosin, rose bengal, pyrenes, anthracenes, phenothiazines, and the like. These sensitizers can be used alone or in combination of two or more. In addition, by blending a dye or a pigment, the latent image in the exposed area can be visualized, and the effect of halation at the time of exposure can be reduced.By blending an adhesion aid, the adhesion to the substrate can be improved. it can. Further, as additives other than the above, an antihalation agent, a storage stabilizer, an antifoaming agent,
Shape improvers and the like, specifically, 4-hydroxy-4'-methylchalcone and the like can be mentioned.

Radiation-Sensitive Resin Composition The radiation-sensitive resin composition of the present invention comprises an acid generator (A) and a resin (B) as essential components, and may optionally contain other acid generators and other acid dissociable compounds. Although it contains a group-containing resin and other additives, the amounts of the main components used are as follows. The amount of the acid generator (A) to be used is generally 0.01 to 30 parts by weight, preferably 0.1 to 20 parts by weight, particularly preferably 0.3 to 100 parts by weight, per 100 parts by weight of all resin components in the resin composition. １５15 parts by weight. In this case, the acid generator (A)
If the amount used is less than 0.01 part by weight, the sensitivity and resolution as a resist tend to decrease, and the effect of reducing nanoedge roughness tends to decrease. Heat resistance tends to decrease.

Compound (1) is used as acid generator (A).
When a mixture of the compound (2) and the compound (2) is used, the weight ratio of the compound (1) is P (g), the compound (2)
Is generally 0.05 <P / Q, where Q is the weight of
<20, preferably 0.1 ≦ P / Q ≦ 15, particularly preferably 0.5 ≦ P / Q ≦ 10. In this case, even if P / Q is 0.05 or less or 20 or more, the effect of improving the pattern shape particularly on a basic substrate tends to decrease.

The amount of the other acid generator to be used is preferably not more than 500% by weight, particularly preferably not more than 400% by weight, based on the acid generator (A). In this case, if the amount of the other acid generator used exceeds 500% by weight, the effect of reducing nanoedge roughness may be impaired. The amount of the acid diffusion controller used varies depending on the type thereof, the type of the acid generator (A) and the other acid generators, etc., and usually, per 100 parts by weight of all resin components in the resin composition, It is at most 10 parts by weight, preferably at most 5 parts by weight. In this case, if the amount of the acid diffusion controller exceeds 10 parts by weight, the sensitivity as a resist and the developability of the exposed portion tend to decrease. The amount of the surfactant used is usually 2 parts by weight or less as an active ingredient of the surfactant per 100 parts by weight of all the resin components in the resin composition. The amount of the sensitizer used is usually 50 parts by weight per 100 parts by weight of all resin components in the resin composition.
It is at most 30 parts by weight, preferably at most 30 parts by weight.

Composition Solution The radiation-sensitive resin composition of the present invention may be used,
Usually, the composition is prepared as a composition solution by dissolving in a solvent so that the solid content concentration becomes, for example, 1 to 50% by weight, and then filtering through, for example, a filter having a pore size of about 0.2 μm. Examples of the solvent include ethers, esters, ether esters, ketones, ketone esters, amides, amide esters, lactams, lactones, (halogenated) hydrocarbons, and the like. Are ethylene glycol monoalkyl ethers, diethylene glycol dialkyl ethers, propylene glycol monoalkyl ethers, propylene glycol dialkyl ethers, ethylene glycol monoalkyl ether acetates, propylene glycol monoalkyl ether acetates, acetates, hydroxyacetate , Lactate esters, alkoxyacetate esters, acetoacetate esters, pyruvate esters, propionate esters, butyrate esters, 2
-Hydroxy-2-methylpropionates, 3
-Alkoxypropionic esters, 2-hydroxy-3-methylbutyric esters, acyclic or cyclic ketones, N, N-dialkylformamides, N, N-
Examples thereof include dialkylacetamides, N-alkylpyrrolidones, γ-lactones, (halogenated) aliphatic hydrocarbons, and (halogenated) aromatic hydrocarbons.

Specific examples of such a solvent include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol mono-n-butyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, and diethylene glycol diethyl ether. -N-propyl ether, diethylene glycol di-n-butyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol mono-n
-Propyl ether acetate, isopropenyl propionate, ethyl acetate, n-propyl acetate, i-propenyl acetate, n-butyl acetate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, ethyl hydroxyacetate, lactic acid Ethyl, ethyl ethoxyacetate, methyl acetoacetate, ethyl acetoacetate, 3-methyl-3-methoxybutylpropionate, 3-methyl-3
-Methoxybutyl butyrate, ethyl 2-hydroxy-2-methylpropionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, 2-hydroxy-3 -Methyl methylbutyrate, methyl ethyl ketone, cyclohexanone, 2-heptanone, 3-
Heptanone, 4-heptanone, N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, toluene, xylene and the like can be mentioned. Among these solvents, propylene glycol monoalkyl ether acetates, lactate esters, 3-alkoxypropionate esters, 2-heptanone, cycloheptanone and the like are preferable. The solvents may be used alone or in combination of two or more.

The solvent may further include benzyl ethyl ether, di-n-hexyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, acetonylacetone, isophorone, caproic acid, caprylic acid, 1-octanol, if necessary.
1-nonanol, benzyl alcohol, benzyl acetate,
One or more high-boiling solvents such as ethyl benzoate, diethyl oxalate, diethyl maleate, γ-butyrolactone, ethylene carbonate, propylene carbonate, and ethylene glycol monophenyl ether acetate can also be added.

Formation of Resist Pattern The radiation-sensitive resin composition of the present invention contains a resin (B) having an acid-dissociable acetal structure, and is exposed to the action of an acid generated from an acid generator (A) upon exposure. The acetal group is dissociated to form a phenolic hydroxyl group, whereby the resin becomes easily alkali-soluble or alkali-soluble, thereby forming a positive 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 onto a substrate by means such as spin coating, casting coating, roll coating, or the like. By doing so, a resist film is formed. As the substrate, for example, a silicon substrate, a substrate coated with aluminum, a basic substrate such as silicon nitride or titanium nitride, a substrate coated with an inorganic nitride film or an organic antireflection film, or the like can be used. Next, after performing a heat treatment (hereinafter, referred to as “PB”), the resist film is exposed to light through a predetermined mask pattern. The radiation used at this time is the emission line spectrum of a mercury lamp (wavelength 2
54 nm), KrF excimer laser (wavelength 248 n)
m), ArF excimer laser (wavelength 193 nm), F
₂ Far-ultraviolet rays such as excimer laser (wavelength 157 nm) and charged particle beams such as electron beams are preferable, but depending on the type of other acid generator, X-rays such as synchrotron radiation and i-rays (wavelength 365 nm) Ordinary ultraviolet rays such as the above can also be used. Exposure conditions such as radiation dose are appropriately selected according to the composition of the resin composition, the type of additive, and the like.

After the exposure, in order to improve the apparent sensitivity of the resist, it is preferable to perform a heat treatment (hereinafter, referred to as “PEB”). The heating conditions vary depending on the composition of the resin composition, types of additives, and the like.
The temperature is 200 ° C, preferably 50 to 150 ° C. afterwards,
A predetermined resist pattern is formed by developing with an alkali developing solution. Examples of the alkali developer include alkali metal hydroxide, aqueous ammonia, alkylamines, alkanolamines, heterocyclic amines, tetraalkylammonium hydroxides, choline,
One or more kinds of alkaline compounds such as 1,8-diazabicyclo [5.4.0] -7-undecene and 1,5-diazabicyclo [4.3.0] -5-nonene are usually used in an amount of 5 to 10%.
An alkaline aqueous solution dissolved to a concentration of 2% by weight, preferably 2 to 5% by weight is used. Particularly preferred alkaline developers are aqueous solutions of tetraalkylammonium hydroxides. Further, for example, an appropriate amount of a water-soluble organic solvent such as methanol or ethanol, a surfactant, or the like can be added to the developer composed of the alkaline aqueous solution. When a developer composed of an alkaline aqueous solution is used, washing is generally performed after development.

[0081]

Embodiments of the present invention will now be described more specifically with reference to the following examples. However, the present invention is not limited to these embodiments.

EXAMPLES Examples 1 to 35 and Comparative Examples 1 to 3 The components shown in Table 1, Table 2-1 and Table 2-2 (parts are based on weight) are mixed to form a uniform solution. The solution was filtered through a membrane filter made of Teflon (registered trademark) having a pore size of 0.2 μm to prepare a composition solution. Next, each composition solution was spin-coated on a silicon wafer, and then subjected to PB at the temperature and time shown in Table 3, Table 4-1 and Table 4-2 to obtain a 0.5 μm-thick resist film or A resist film having a thickness of 0.1 μm (however, when exposed with an F ₂ excimer laser) was formed. A KrF excimer laser irradiation device (trade name: NSR-
2005 EX8A, manufactured by Nikon Corporation)
An excimer laser (wavelength: 248 nm) was exposed through a mask pattern while changing the exposure amount. In some embodiments, a KrF excimer laser was replaced with a simple electron beam direct writing apparatus (50 KeV) (trade name: HL700DM (current density: 4.5 A), manufactured by Hitachi, Ltd.) Either exposing the electron beam through the mask pattern with different exposure amount,
Alternatively, a simple F ₂ excimer laser irradiation device (Ex
It was exposed using an F ₂ excimer laser with a different exposure amount through a mask pattern. After exposure, PE was exposed at the temperature and time shown in Table 3, Table 4-1 and Table 4-2.
B was performed. Next, a 2.38% by weight aqueous solution of tetramethylammonium hydroxide was used as a developer,
After developing at 60 ° C. for 60 seconds, the film was washed with water for 30 seconds and dried to form a resist pattern. The evaluation results of each example and comparative example are shown in Table 5, Table 6-1 and Table 6-2. However, when exposed with an F ₂ excimer laser, only the sensitivity and resolution were shown because the thickness of the resist film was extremely small.

Here, each resist was evaluated in the following manner. After exposure by changing the exposure amount in the resist film formed on a sensitivity silicon wafer is performed immediately post-exposure bake, and then After alkali development, washing with water and drying, when forming a resist pattern line width 0. 25 μm line
The exposure amount that forms the AND space pattern (1L1S) with a line width of 1: 1 was defined as the optimal exposure amount, and the optimal exposure amount was defined as the sensitivity. Resolution The minimum dimension (μm) of the resist pattern that was resolved when exposed at the optimum exposure amount was defined as the resolution. Pattern Size The lower side dimension La and the upper side dimension Lb of a rectangular cross section of a line and space pattern (1L1S) having a line width of 0.25 μm formed on a silicon wafer are measured using a scanning electron microscope. , 0.85 ≦ Lb / La ≦ 1, the pattern shape is “good”,
If the condition is not satisfied, the pattern shape is “impossible”
It was assumed to be.

[0083] The composition pattern is "good" in the footing optimum exposure line of a line width 0.25μm formed on a silicon wafer was exposed with and-space pattern (1L1S), the silicon nitride substrate A resist pattern was formed in the same manner as above, and the resulting line having a line width of 0.25 μm was used.
Observing the rectangular cross section of the and space pattern (1L1S) using a scanning electron microscope, measuring Lc and Ld shown in FIG. 2, and determining that Lc / Ld <0.05 was satisfied, "Good" and those which did not satisfy this condition were judged as "impossible" for tailing. The line pattern of the line and space pattern (1L1S) having a line width of 0.25 μm was observed with a scanning electron microscope. As shown in FIG. 1, the line edge was formed along the lateral side of the line pattern. The difference ΔCD between the line width and the design line width of 0.25 μm at the portion where the unevenness was most remarkable was measured and evaluated according to the following criteria. In FIG. 1, (a) is a plan view of the resist pattern, (b) is a side view of the resist pattern, and the irregularities are exaggerated more than actual. ΔCD is less than 0.01 μm: good ΔCD is 0.01 μm or more: bad

Each component used in each Example and Comparative Example was
It is as follows. Acid generator A-1: (5-n-propylsulfonyloxyimino-5
H-thiophen-2-indene) (2-methylpheninone) acetonitrile (compound (1) in which R ¹ is an n-propyl group) A-2: 2,2,2-trifluoro-1- {4- ( 3-
[4- {2,2,2-trifluoro-1- (1-n-propanesulfonyloxyimino) ethyl} phenoxy]
n-propoxy) phenyl} ethaneoxime 1-n-
Propane sulfonate (compound (2) in which ^two R ² are n-propyl groups)

A-1: 1,1-bis (phenylsulfonyl) cyclohexane a-2: triphenylsulfonium nonafluoro-n-butanesulfonate a-3: bis (4-t-butylphenyl) iodonium 1
0-Camphorsulfonate a-4: bis (cyclohexylsulfonyl) diazomethane a-5: bis (1,4-dioxaspiro [4.5] decane-7-sulfonyl) diazomethane a-6: bis (t-butylsulfonyl) diazomethane

Resin (B) B-1: A resin in which 34 mol% of hydrogen atoms of phenolic hydroxyl groups in poly (p-hydroxystyrene) are substituted by 1-ethoxyethyl groups (Mw = 9,000, Mw / Mn =
1.9) B-2: 15 mol% of hydrogen atoms of phenolic hydroxyl groups in poly (p-hydroxystyrene) were substituted with 1-ethoxyethyl groups, and 18 mol% were substituted with 1-ethoxypropyl groups. Resin (Mw = 10,000, Mw / Mn =
1.2) B-3: 25 mol% of hydrogen atoms of phenolic hydroxyl groups in poly (p-hydroxystyrene) were substituted with 1-ethoxyethyl groups, and 8 mol% were substituted with t-butoxycarbonyl groups. Resin (Mw = 10,000, Mw / Mn =
1.1) B-4: A resin in which 23 mol% of hydrogen atoms of phenolic hydroxyl groups in poly (p-hydroxystyrene) are substituted with 1-ethoxyethyl groups and 10 mol% are substituted with t-butyl groups. (Mw = 12,000, Mw / Mn = 1.2) B-5: 25 mol% of hydrogen atoms of phenolic hydroxyl groups in p-hydroxystyrene / styrene copolymer (copolymerization molar ratio = 90/10) Is substituted with a 1-cyclohexyloxyethyl group (Mw = 18,000, Mw / Mn
= 1.9) B-6: 25 mol% of the hydrogen atoms of the phenolic hydroxyl group in the p-hydroxystyrene / t-butyl acrylate copolymer (copolymerization molar ratio = 90:10) is 1-ethoxyethyl group. (Mw = 18,000, Mw / Mn)
= 1.8) B-7: poly (p-hydroxystyrene) (Mw = 5,0)
(Mw / Mn = 1.8), a partially crosslinked resin in which 24 mol% of the hydrogen atoms of the phenolic hydroxyl group is substituted with a 1-ethoxyethyl group and has an average hexamer with a crosslinking group having a diethylene glycol skeleton ( Mw = 30,000, M
w / Mn = 5.0). This resin was obtained by reacting poly (p-hydroxystyrene) (Mw = 5,000) with ethyl vinyl ether and diethylene glycol divinyl ether in the presence of pyridinium p-toluenesulfonate.

Resin (b) b-1: a resin in which 26 mol% of hydrogen atoms of phenolic hydroxyl groups in poly (p-hydroxystyrene) are substituted with t-butoxycarbonyl groups (Mw = 9,000, Mw / M
b-2: a resin in which 25 mol% of hydrogen atoms of phenolic hydroxyl groups in poly (p-hydroxystyrene) are substituted with t-butoxycarbonylmethyl groups (Mw = 25,000,
(Mw / Mn = 1.2) b-3: a resin in which 32 mol% of hydrogen atoms of phenolic hydroxyl groups in poly (p-hydroxystyrene) are substituted with t-butyl groups (Mw = 15,000, Mw / Mn = 1.
1) b-4: p-hydroxystyrene / styrene / t-butyl acrylate copolymer (copolymer molar ratio = 60: 20: 2)
0, Mw = 12,500, Mw / Mn = 1.8)

Dissolution control agent C-1: diphenolic acid C-2: 2-hydroxybenzophenonic acid diffusion control agent D-1: n-dodecyldimethylamine D-2: tri-n-hexylamine D-3: benzimidazole D-4: 2-benzylpyridine D-5: 2-phenylbenzimidazole D-6: triethanolamine D-7: tri-n-octylamine solvent E-1: ethyl lactate E-2: propylene glycol monomethyl ether acetate E-3: 2-heptanone

[0089]

[Table 1]

[0090]

[Table 2]

[0091]

[Table 3]

[0092]

[Table 4]

[0093]

[Table 5]

[0094]

[Table 6]

[0095]

[Table 7]

[0096]

[Table 8]

[0097]

[Table 9]

[0098]

The radiation-sensitive resin composition of the present invention has particularly high sensitivity (low exposure energy), excellent resolution performance, and can suppress nanoedge roughness. Further, the radiation-sensitive resin composition of the present invention using the acid generator (A) composed of a mixture of the compound (1) and the compound (2) has a very small footing of the resist pattern even on a basic substrate. That is, the pattern shape is further improved. Therefore, the radiation-sensitive resin composition of the present invention is extremely useful as a chemically amplified resist for manufacturing semiconductor devices, which is expected to be further miniaturized in the future.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining a procedure for evaluating nanoedge roughness.

FIG. 2 is a diagram for explaining a tailing evaluation procedure.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 21/027 H01L 21/30 502R (72) Inventor Kenichi Yokoyama 2-11-24 Tsukiji, Chuo-ku, Tokyo Within JSR Co., Ltd. (72) Eiichi Kobayashi Inventor Eiichi Kobayashi 2-11-24 Tsukiji, Chuo-ku, Tokyo JSR Co., Ltd. F-term (reference) 2H025 AA03 AB16 AD03 BE00 BE07 BE10 BF15 BG00 CB45 FA17 4J002 BC121 EB106 EV236 EV296 EV306 FD146

Claims (2)

[Claims] (A) a radiation-sensitive acid generator comprising at least one selected from the group consisting of a compound represented by the following formula (1) and a compound represented by the following formula (2): [In the formula (1), R ¹ is a linear group having 1 to 10 carbon atoms;
It represents a branched or cyclic alkyl group, a linear, branched or cyclic fluoroalkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 11 carbon atoms which may be substituted by fluorine. [Chemical formula 2] [In the formula (2), each R ² independently has 1 to 1 carbon atoms.
10 linear, branched or cyclic alkyl groups, 1 to 10 linear, branched or cyclic fluoroalkyl groups or 6 to 6 carbon atoms which may be substituted by fluorine
And 11 represents an aryl group. And (B) the following formula (3)
A resin having a repeating unit represented by the following formula and a repeating unit represented by the following formula (4): [In the formula (3), R ³ represents a methyl group or an ethyl group, and R ⁴ represents a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms. [Formula 4] A radiation-sensitive resin composition comprising: 2. The composition according to claim 1, wherein the radiation-sensitive acid generator as the component (A) comprises a mixture of a compound represented by the formula (1) and a compound represented by the formula (2). Radiation-sensitive resin composition.