JPH09325473A - Radiation-sensitive resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the characteristic balance such as the pattern shape, sensitivity, resolution, developing property and focus tolerance by using a copolymer containing specific repeated units, having a specific light transmission factor, and containing an alkali-soluble resin and a radiation-sensitive acied generating agent. SOLUTION: This copolymer contains a cyclic unit expressed by the formula I and a cyclic unit expressed by a formula II, it has the light transmission factor of 50% or above for the film thickness of 1μm at the wavelength of 248nm, and it contains an alkali-soluble resin and a radiation-sensitive acid generating agent. In the formulas, R<1> and R<2> represent hydrogen atom or methyl group, R<3> represents hydrogen atom, chain alkyl group having 1-10 carbon atoms, cyclic alkyl group having 3-10 carbon atoms, aryl group having 6-10 carbon atoms, or aralkyl group having 7-11 carbon atoms, and R<4> and R<5> independently represent chain alkyl group having 1-10 carbon atoms, halogenated chain alkyl group having 1-10 carbon atoms, or cyclic alkyl group having 3-10 carbon atoms.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a radiation-sensitive resin composition, and more particularly to a radiation-sensitive resin composition useful as a resist suitable for fine processing using a KrF excimer laser.

[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 700-40
It is difficult to form such a fine pattern with high precision by the method using 0 nm) or near ultraviolet rays (wavelength 400 to 300 nm), and therefore, a wider focal depth can be achieved, which is effective for the miniaturization of design rules. A lithographic process using radiation with a short wavelength (wavelength of 300 nm or less) has been proposed. Examples of the lithography process using such short-wavelength radiation include deep ultraviolet rays such as KrF excimer laser (wavelength 248 nm) and ArF excimer laser (wavelength 193 nm), and charged particle beams such as X-rays such as synchrotron radiation and electron beams. A method of using is proposed. As a high-resolution resist for such short-wavelength radiation, "Chemically Amplified Resist" was proposed by International Business Machines (IBM), and currently, improvement and development of this chemically amplified resist are being proposed. It is being energetically advanced. The chemically amplified resist generates an acid by irradiation of a radiation-sensitive acid generator contained therein (hereinafter, referred to as “exposure”), and the acid acts as a catalyst.
A pattern is formed by utilizing a phenomenon that a chemical reaction (for example, change in polarity, cleavage of chemical bond, cross-linking reaction, etc.) occurs in the resist film and the solubility in a developing solution changes in an exposed portion. Conventionally, among such chemically amplified resists, those having relatively good resist performance are protected with a t-butyl ester group or a t-butoxycarbonyl group as an ingredient of an alkali-soluble resin in an alkali-soluble resin. A resist using a resin (see, for example, Japanese Patent Publication No. 27660/1990) 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. That is, t-butyl ester group and t-
When a resin having a butoxycarbonyl group is used, a chemical reaction due to the catalytic action of an acid generated by exposure causes
Since gas components such as isobutene gas and carbon dioxide gas are released, volume contraction occurs in the exposed portion, and as a result, the pattern shape is easily distorted and it is difficult to form a highly accurate resist pattern. Furthermore, in recent years, a chemically amplified resist using a resin component having a repeating unit composed of an acetal derivative or a ketal derivative of hydroxystyrene has been proposed (for example, JP-A-2-161436 and JP-A-3-282550, Kaihei 4-219
757, JP-A-5-249682, JP-A-5-281745, JP-A-7-140666, and JP-A-8-15864). However, each of these resists also has its own problems.
As a big problem, due to the influence of a standing wave due to the interference between the incident wave and the reflected wave when the resist film is exposed,
The pattern shape may be deteriorated, scum is likely to occur during development, and there is a problem in developability, and further improvement is required from the viewpoint of overall characteristics as a chemically amplified resist.

[0003]

SUMMARY OF THE INVENTION In view of such circumstances, the present invention has been found as a result of further detailed study of the resin component constituting the chemically amplified resist, and the problem is the KrF. Useful as a chemically amplified resist that is sensitive to excimer laser (wavelength 248 nm), has less influence of standing waves, has an excellent pattern shape, and has a good balance of characteristics including sensitivity, resolution, developability, focus tolerance, etc. It is to provide a radiation-sensitive resin composition.

[0004]

According to the present invention, the above-mentioned problems are (A) a copolymer containing a repeating unit represented by the following formula (1) and a repeating unit represented by the following formula (2). Coalescing,

[0005]

[Formula 1]

[In the formula (1), R ¹ represents a hydrogen atom or a methyl group. ],

[0007]

(Equation 2)

[In the formula (2), R ² represents a hydrogen atom or a methyl group, R ³ represents a hydrogen atom, a chain alkyl group having 1 to 10 carbon atoms, a cyclic alkyl group having 3 to 10 carbon atoms, or a carbon number 6-10 of an aryl group or an aralkyl group having 7 to 11 carbon atoms, R ⁴ and R ⁵ are each independently 1 to carbon atoms
Is a chain alkyl group having 10 carbon atoms, a halogenated chain alkyl group having 1 to 10 carbon atoms, a cyclic alkyl group having 3 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms or an aralkyl group having 7 to 11 carbon atoms? , Or any one of R ³ , R ⁴ and R ⁵
Two are bonded to each other to form a 5- to 7-membered ring. ],
(B) The light transmittance at a wavelength of 248 nm is 1 μm.
50% or more of the alkali-soluble resin, and (C) a radiation-sensitive acid generator characterized by containing a radiation-sensitive acid generator.

Hereinafter, the present invention will be described in detail. (A) Copolymer The component (A) in the present invention comprises the repeating unit represented by the above formula (1) (hereinafter referred to as “repeating unit (1)”) and the repeating unit represented by the above formula (2). A copolymer (hereinafter, referred to as a unit (hereinafter, referred to as "repeating unit (2)")
It is called "(A) copolymer". ). In the formula (2), the chain alkyl group having 1 to 10 carbon atoms of R ³ may be linear or branched, and examples thereof include a methyl group, an ethyl group, an n-propyl group, and i. -Propyl group, n-
Butyl group, i-butyl group, sec-butyl group, t-butyl group, n-pentyl group, neopentyl group, n-hexyl group, n-heptyl group, n-octyl group, 2-ethylhexyl group, n-nonyl group , N-decyl group and the like. Examples of the cyclic alkyl group having 3 to 10 carbon atoms of R ³ include cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, norbornyl group, isobornyl group and the like. . Further, the carbon number of R ³ is 6 to 10
Examples of the aryl group include a phenyl group, a tolyl group,
Examples thereof include a xylyl group, a cumenyl group and a 1-naphthyl group. Further, examples of the aralkyl group having 7 to 11 carbon atoms of R ³ include benzyl, α-methylbenzyl group, phenethyl group, naphthylmethyl group and the like. Further, R ⁴ and R ^{5 have} a chain alkyl group having 1 to 10 carbon atoms, a cyclic alkyl group having 3 to 10 carbon atoms, and have 6 to 1 carbon atoms.
Examples of the aryl group of 0 or the aralkyl group of 7 to 11 carbon atoms include the same groups as those exemplified for R ³ . Further, examples of the halogenated chain alkyl group having 1 to 10 carbon atoms of R ⁴ and R ⁵ include halogenated derivatives of the chain alkyl group having 1 to 10 carbon atoms exemplified for R ³ . Furthermore, any two of R ³ , R ⁴ and R ⁵ are bound to each other 5
Of 7-membered ring, the 5- to 7-membered ring and R ³ and R ⁴ are bonded, and examples thereof include a cyclopentyl group, a cyclohexyl group, a cycloheptyl group and the like. Further, examples of the 5- to 7-membered ring in which R ³ and R ⁵ or R ⁴ and R ⁵ are bonded to each other include a tetrahydrofuranyl group and a tetrahydropyranyl group.

The group --OC (R ³ ) (R ⁴ ) OR ⁵ in formula (2) is
It represents an acetal group or a ketal group. Specific examples of such acetal group include 1-methoxyethoxy group, 1-ethoxyethoxy group, 1-n-propoxyethoxy group, 1-i-propoxyethoxy group, 1-n-butoxyethoxy group, 1-i. -Butoxyethoxy group, 1-
sec-butoxyethoxy group, 1-t-butoxyethoxy group, 1-trifluoroethoxyethoxy group, 1-hexafluoropropoxyethoxy group, 1-cyclopentyloxyethoxy group, 1-cyclohexyloxyethoxy group, 1-norbornyloxy group Ethoxy group, 1-bornyloxyethoxy group, 1-phenyloxyethoxy group, 1
-(1-naphthyloxy) ethoxy group, 1-benzyloxyethoxy group, 1-phenethyloxyethoxy group,
(Cyclohexyl) (methoxy) methoxy group, (cyclohexyl) (ethoxy) methoxy group, (cyclohexyl) (n-propoxy) methoxy group, (cyclohexyl) (i-propoxy) methoxy group, (cyclohexyl) (trifluoroethoxy) methoxy group A (cyclohexyl) (hexafluoropropoxy) methoxy group,
(Cyclohexyl) (cyclohexyloxy) methoxy group, (cyclohexyl) (phenoxy) methoxy group,
(Cyclohexyl) (benzyloxy) methoxy group,
(Phenyl) (methoxy) methoxy group, (phenyl)
(Ethoxy) methoxy group, (phenyl) (n-propoxy) methoxy group, (phenyl) (i-propoxy) methoxy group, (phenyl) (trifluoroethoxy) methoxy group, (phenyl) (hexafluoropropoxy) methoxy group, (Phenyl) (cyclohexyloxy) methoxy group, (phenyl) (phenoxy) methoxy group, (phenyl) (benzyloxy) methoxy group, (benzyl)
(Methoxy) methoxy group, (benzyl) (ethoxy) methoxy group, (benzyl) (n-propoxy) methoxy group, (benzyl) (i-propoxy) methoxy group, (benzyl) (trifluoroethoxy) methoxy group, (benzyl ) (Hexafluoropropoxy) methoxy group, (benzyl) (cyclohexyloxy) methoxy group, (benzyl) (phenoxy) methoxy group, (benzyl) (benzyloxy) methoxy group, 2-tetrahydrofuranyloxy group, 2-tetrahydropyranyl An oxy group etc. can be mentioned.

Specific examples of the ketal group include 1-
Methyl-1-methoxyethoxy group, 1-methyl-1-ethoxyethoxy group, 1-methyl-1-n-propoxyethoxy group, 1-methyl-1-i-propoxyethoxy group, 1-methyl-1-n- Butoxyethoxy group, 1-methyl-1-i-butoxyethoxy group, 1-methyl-1-
sec-butoxyethoxy group, 1-methyl-1-t-butoxyethoxy group, 1-methyl-1-trifluoroethoxyethoxy group, 1-methyl-1-hexafluoropropoxyethoxy group, 1-methyl-1-cyclopentyloxy group Ethoxy group, 1-methyl-1-cyclohexyloxyethoxy group, 1-methyl-1-norbornyloxyethoxy group, 1-methyl-1-bornyloxyethoxy group, 1-methyl-1-phenyloxyethoxy group, 1-
Methyl-1- (1-naphthyloxy) ethoxy group, 1-
Methyl-1-benzyloxyethoxy group, 1-methyl-
1-phenethyloxyethoxy group, 1-cyclohexyl-1-methoxyethoxy group, 1-cyclohexyl-1-
Ethoxyethoxy group, 1-cyclohexyl-1-n-propoxyethoxy group, 1-cyclohexyl-i-propoxyethoxy group, 1-cyclohexyl-1-trifluoroethoxyethoxy group, 1-cyclohexyl-1-hexafluoropropoxyethoxy group, 1-cyclohexyl-1-cyclohexyloxyethoxy group, 1-cyclohexyl-1-phenoxyethoxy group, 1-cyclohexyl-1-benzyloxyethoxy group, 1-phenyl-1
-Methoxyethoxy group, 1-phenyl-1-ethoxyethoxy group, 1-phenyl-1-n-propoxyethoxy group, 1-phenyl-1-i-propoxyethoxy group, 1
-Phenyl-1-trifluoroethoxyethoxy group, 1
-Phenyl-1-hexafluoropropoxyethoxy group, 1-phenyl-1-cyclohexyloxyethoxy group, 1-phenyl-1-phenyloxyethoxy group, 1
-Phenyl-1-benzyloxyethoxy group, 1-benzyl-1-methoxyethoxy group, 1-benzyl-1-ethoxyethoxy group, 1-benzyl-1-n-propoxyethoxy group, 1-benzyl-1-i- Propoxyethoxy group, 1-benzyl-1-trifluoroethoxyethoxy group, 1-benzyl-1-hexafluoropropoxyethoxy group, 1-benzyl-1-cyclohexyloxyethoxy group, 1-benzyl-1-phenyloxyethoxy group, 1-benzyl-1-benzyloxyethoxy group, 2
-(2-methyl-tetrahydrofuranyl) oxy group, 2
-(2-methyl-tetrahydropyranyl) oxy group, 1
-Methoxy-cyclopentyloxy group, 1-methoxy-
A cyclohexyloxy group etc. can be mentioned.

In the copolymer (A), the repeating unit (1) and the repeating unit (2) may be present alone or in combination of two or more. The content of each repeating unit in the (A) copolymer is such that the repeating unit (1) is
It is usually 40 to 90 mol%, preferably 50 to 80 mol%, more preferably 55 to 75 mol%, and therefore the repeating unit (2) is usually 10 to 60 mol%, preferably 20 to 50 mol%. And more preferably 25 to 4
It is 5 mol%. In this case, if the content of the repeating unit (2) is less than 10 mol%, the resolution as a resist tends to decrease, while if it exceeds 60 mol%, the sensitivity tends to decrease. The (A) copolymer is, for example, (a) poly (p-hydroxystyrene) and / or poly (p
A compound such as alkyl vinyl ether, 2,3-dihydro-4H-pyran, 4-methoxy-5,6-dihydro-2H-pyran, 2-methoxypropylene. (B) poly (p-
Hydroxystyrene) and / or sodium phenoxide derivative of poly (p-hydroxy-α-methylstyrene) and the formula Cl-C (R ³ ) (R ⁴ ) OR ⁵ (wherein R ^{3 to} R ⁵ are respectively represented by the formula ( A compound represented by R ^{3 to} R ⁵ in 2), which is etherified by a dechlorination reaction with a compound represented by the formula (3), and (c) a monomer corresponding to the repeating unit (1) and a repeating unit. It can be produced by a method such as direct copolymerization with the monomer corresponding to (2). The (A) copolymer is a gel permeation chromatography (GP
C) polystyrene equivalent weight average molecular weight (hereinafter,
It is called "Mw". ) Is usually 1,000 to 100,0
00, preferably 3,000 to 40,000, and more preferably 3,000 to 30,000. in this case,
If the Mw of the (A) copolymer is less than 1,000, the sensitivity and heat resistance of the resist tend to be lowered,
On the other hand, when it exceeds 100,000, the solubility in the developing solution tends to decrease. Further, GPC of the (A) copolymer
Mw and polystyrene equivalent number average molecular weight (hereinafter,
It is called "Mn". ) Ratio (Mw / Mn) is usually 1
To 3, preferably 1 to 2.5, more preferably 1 to
2.0, particularly preferably 1.01 to 1.7.
The (A) copolymer is usually insoluble in an alkali developing solution. In the present invention, the (A) copolymer may be used alone or in combination of two or more.

(B) Alkali-Soluble Resin Next, the component (B) in the present invention is an alkali-soluble resin having a light transmittance at a wavelength of 248 nm (hereinafter referred to as “T ₂₄₈ ”) of 50% or more per 1 μm of film thickness. It is made of a resin (hereinafter referred to as “(B) alkali-soluble resin”) and is soluble in an alkali developing solution. Here, "T
₂₄₈ is 50% or more per 1 μm of film thickness ”means that a 1 μm-thick alkali-soluble resin film obtained by spin-coating a propylene glycol monomethyl ether acetate solution of an alkali-soluble resin and baking at 90 ° C. for 60 seconds, T ₂₄₈ measured using UV spectrum meter
Means 50% or more. Such (B)
Examples of the alkali-soluble resin include poly (o-hydroxystyrene), poly (m-hydroxystyrene), poly (p-hydroxystyrene); poly (o-hydroxy-α-methylstyrene), poly (m-hydroxy-α). −
Methylstyrene), poly (p-hydroxy-α-methylstyrene); o-hydroxystyrene, m-hydroxystyrene and p-hydroxystyrene (hereinafter, these are collectively referred to as “hydroxystyrenes”).
A copolymer of at least one of styrene and / or α-methylstyrene; o-hydroxy-α-methylstyrene, m-hydroxy-α-methylstyrene and p.
-Hydroxy-α-methylstyrene (hereinafter collectively referred to as “hydroxy-α-methylstyrenes”) and styrene and / or α
-Copolymer with methylstyrene; at least one of o-hydroxystyrene, m-hydroxystyrene and p-hydroxystyrene and o-hydroxy-α-methylstyrene, m-hydroxy-α-methylstyrene and p
-Copolymer with at least one of hydroxy-α-methylstyrene; at least one of o-hydroxystyrene, m-hydroxystyrene and p-hydroxystyrene
A copolymer of a seed and (meth) acrylic acid; at least one of o-hydroxy-α-methylstyrene, m-hydroxy-α-methylstyrene and p-hydroxy-α-methylstyrene, and (meth) acrylic acid. A copolymer of o;
Hydroxystyrene, m-hydroxystyrene and p
-At least one of hydroxystyrene and alkyl (meth) acrylate (the number of carbon atoms in the alkyl group is, for example, 1 to
4) Copolymer with at least one of o-hydroxy-α-methylstyrene, m-hydroxy-α-methylstyrene and p-hydroxy-α-methylstyrene and alkyl (meth) acrylate (carbon of alkyl group). The number is, for example, a copolymer with 1 to 4); polyvinyl alcohol, partially saponified polyvinyl alcohol; poly (meth) acrylic acid; (meth) acrylic acid and alkyl (meth) acrylate (the carbon number of the alkyl group is, for example, 1 to 4) and the like. Among these (B) alkali-soluble resins, poly (o-hydroxystyrene), p-
A copolymer of hydroxystyrene and styrene, a copolymer of p-hydroxystyrene and alkyl (meth) acrylate (the carbon number of the alkyl group is, for example, 1 to 4) and the like are preferable. In the case of a copolymer of p-hydroxystyrene and styrene and a copolymer of p-hydroxystyrene and alkyl (meth) acrylate (the carbon number of the alkyl group is, for example, 1 to 4), styrene in the copolymer is used. Or (meta)
Content of alkyl acrylate is preferably 30 mol%
Hereafter, it is more preferably 20 mol% or less. In this case, when the content of styrene or alkyl (meth) acrylate exceeds 30 mol%, the alkali solubility of the (B) alkali-soluble resin is lowered, scum is easily generated during development, and the pattern shape is deteriorated. Tend to do.
The Mw of the (B) alkali-soluble resin is usually 1,000.
~ 100,000, preferably 3,000 ~ 50,000
It is 0, more preferably 3,000 to 30,000. In this case, the Mw of the (B) alkali-soluble resin is 1,
If it is less than 000, the resolution tends to decrease, while if it exceeds 100,000, the viscosity of the resist solution becomes high, and when applied to a wafer, the film thickness in the applied region tends to become nonuniform. In the present invention, the alkali-soluble resin (B) may be used alone or in combination of two or more.

In the present invention, (A) copolymer and (B)
The ratio ((A) / (B)) to the alkali-soluble resin is usually 30 to 90/70 to 10, preferably 50 to 90 /.
50 to 10, more preferably 70 to 90/30 to 10
It is. In this case, if (A) / (B) is less than 30/70, the resolution as a resist tends to decrease, while if it exceeds 90/10, scum tends to occur during development.

(C) Radiation-sensitive acid generator Further, examples of the radiation-sensitive acid generator (hereinafter referred to as “(C) acid generator”) which is the component (C) in the present invention include the following onium. Examples thereof include salt compounds, sulfonimide compounds, halogen-containing compounds, sulfone compounds, sulfonic acid ester compounds, quinonediazide compounds and diazomethane compounds. Onium salt compounds Examples of onium salt compounds include sulfonium salts, iodonium salts, phosphonium salts, diazonium salts, pyridinium salts and the like. Specific examples of the onium salt compound include triphenylsulfonium triflate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium naphthalene sulfonate, (hydroxyphenyl) benzylmethylsulfonium toluenesulfonate, diphenyliodonium triflate, diphenyliodonium pyrenesulfonate, diphenyl. Examples thereof include iodonium dodecylbenzene sulfonate and diphenyliodonium hexafluoroantimonate. Sulfonimide Compound Examples of the sulfonimide compound include compounds represented by the following formula (3).

[0016]

Embedded image

[In the formula (3), Q is an alkylene group,
Represents a divalent group such as an arylene group or an alkoxylene group,
R ⁶ is an alkyl group, an aryl group, a halogenated alkyl group,
A monovalent group such as a halogenated aryl group is shown. 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- (camphanylsulfonyl) Oxy) succinimide, N- (camphanylsulfonyloxy) phthalimide, N- (camphanylsulfonyloxy) diphenylmaleimide, N- (camphanylsulfonyloxy) bicyclo [2.2.1] hept-
5-ene-2,3-dicarboximide, N- (camphanylsulfonyloxy) -7-oxabicyclo [2.
2.1] Hept-5-ene-2,3-dicarboximide, N- (camphanylsulfonyloxy) bicyclo [2.2.1] heptane-5,6-oxy-2,3-dicarboximide, N- (camphanylsulfonyloxy) naphthylimide, N- (campanylsulfonyloxy) naphthyldicarboximide, 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) 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-trifluoromethylphenylsulfonyloxy) naphthylimide, N- (4-fluorophenylsulfonyloxy)
Succinimide, N- (2-fluorophenylsulfonyloxy) phthalimide, N- (4-fluorophenylsulfonyloxy) diphenylmaleimide, N- (4-
Fluorophenylsulfonyloxy) bicyclo [2.
2.1] Hept-5-ene-2,3-dicarboximide, N- (trifluoromethylsulfonyloxy) -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) naphthyl dicarboximide and the like can be mentioned.

Halogen-Containing Compound Examples of the halogen-containing compound include haloalkyl group-containing hydrocarbon compounds and haloalkyl group-containing heterocyclic compounds. Specific examples of the halogen-containing compound include phenyl-bis (trichloromethyl) -s-
(Poly) trichloromethyl-s-triazine derivatives such as triazine, methoxyphenyl-bis (trichloromethyl) -s-triazine, naphthyl-bis (trichloromethyl) -s-triazine, and 1,1-bis (4-chlorophenyl) -2,2,2-trichloroethane etc. can be mentioned. Sulfone compound Examples of the sulfone compound include β-ketosulfone and β
-Sulfonyl sulfone, these α-diazo compounds and the like can be mentioned. Specific examples of the sulfone compound include phenacylphenylsulfone, mesitylphenacylsulfone, bis (phenylsulfonyl) methane, 4-trisphenacylsulfone, and the like. Sulfonic acid ester compound Examples of the sulfonic acid ester compound include alkyl sulfonic acid ester, haloalkyl sulfonic acid ester,
Aryl sulfonate, imino sulfonate, etc. can be mentioned. Specific examples of the sulfonic acid ester compound include benzoin tosylate, pyrogallol tris triflate, pyrogallol methanesulfonic acid triester, and nitrobenzyl-9,10-diethoxyanthracene-2-sulfonate, and particularly pyrogallol methane. Sulfonic acid triesters are preferred.

Quinonediazide Compounds The quinonediazide compounds include 1,2-benzoquinonediazide-4-sulfonyl group, 1,2-naphthoquinonediazide-4-sulfonyl group, 1,2-naphthoquinonediazide-5-sulfonyl group, 1,2- Examples thereof include compounds having a 1,2-quinonediazidesulfonyl group such as naphthoquinonediazide-6-sulfonyl group, and compounds having a 1,2-naphthoquinonediazide-4-sulfonyl group are particularly preferable. Diazomethane Compound As the diazomethane compound, for example, a compound represented by the following formula (4) can be mentioned.

[0020]

Embedded image

[In the formula (4), R ⁷ and R ⁸ each independently represent a monovalent group such as an alkyl group, an aryl group, a halogen-substituted alkyl group or 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 (C) acid generators, onium salt compounds, sulfonimide compounds and diazomethane compounds are particularly preferable, and triphenylsulfonium triflate and N- (trifluoromethylsulfonyloxy) bicyclo [2.2.
1] Hept-5-ene-2,3-dicarboximide, N
-(Camphanylsulfonyloxy) bicyclo [2.
2.1] Hept-5-ene-2,3-dicarboximide, N- (camphanylsulfonyloxy) naphthyldicarboximide, bis (cyclohexylsulfonyl) diazomethane and the like are preferable. In the present invention, the (C) acid generator may be used alone or in admixture of two or more. The amount of the (C) acid generator used in the present invention is
The amount is appropriately selected depending on the kind, but is usually 0.1 to 20 parts by weight, preferably 0.5 to 1 per 100 parts by weight of the total of (A) copolymer and (B) alkali-soluble resin.
0 parts by weight. In this case, if the amount of the (C) acid generator used is less than 0.1 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 20 parts by weight may be added. If it exceeds the above range, uneven coating may occur during application of the composition, or scum may occur during development.

Acid Diffusion Control Agent In the present invention, the action of controlling the diffusion phenomenon of the acid (C) generated from the acid generator in the resist film by exposure to suppress an undesired chemical reaction in the unexposed region. It is preferable to add an acid diffusion control agent having, for example,
By using such an acid diffusion control agent, the storage stability of the composition is improved, the resolution as a resist is improved, and the post-exposure time delay (post-exposure time delay: PED) after exposure is improved. The change in the line width of the resist pattern due to the change can be suppressed, and the process stability becomes extremely excellent. The acid diffusion control agent is preferably a nitrogen-containing organic compound whose basicity does not change by exposure or baking, and specific examples thereof include the general formula
R ⁹ R ¹⁰ R ¹¹ N (provided that R ⁹ , R ¹⁰ and R ¹¹ are each independently a hydrogen atom, an alkyl group, an aryl group or an aralkyl group.) (Hereinafter, referred to as “nitrogen-containing compound ( I) "), a diamino compound having two nitrogen atoms in the same molecule (hereinafter referred to as" nitrogen-containing compound (II) "), a polymer having three or more nitrogen atoms (hereinafter
It is called "nitrogen-containing compound (III)". ), An amide group-containing compound, a urea compound, a nitrogen-containing heterocyclic compound, and the like.

As the nitrogen-containing compound (I), for example, n-
Monoalkylamines such as hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine; di-n-butylamine, di-n-pentylamine, di-n-hexylamine, di-n -Dialkylamines such as heptylamine, di-n-octylamine, di-n-nonylamine, di-n-decylamine;
Triethylamine, tri-n-propylamine, tri-
n-butylamine, tri-n-pentylamine, tri-
Trialkylamines such as n-hexylamine, tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine; aniline, N-methylaniline, N, N-dimethylaniline ,
Aromatic amines such as 2-methylaniline, 3-methylaniline, 4-methylaniline, 4-nitroaniline, diphenylamine, triphenylamine and naphthylamine can be mentioned.

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, 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,
Examples thereof include 1,4-bis [1- (4-aminophenyl) -1-methylethyl] benzene and 1,3-bis [1- (4-aminophenyl) -1-methylethyl] benzene.

Examples of the nitrogen-containing compound (III) include polyethyleneimine, polyallylamine, and polymers of dimethylaminoethylacrylamide.
Examples of the amide group-containing compound include formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N,
Examples thereof include N-dimethylacetamide, propionamide, benzamide, pyrrolidone and N-methylpyrrolidone. Examples of the urea compound include urea, methylurea, 1,1-dimethylurea and 1,3-
Examples thereof include dimethylurea, 1,1,3,3-tetramethylurea, 1,3-diphenylurea, and tributylthiourea.

Examples of the nitrogen-containing heterocyclic compound include imidazoles such as imidazole, benzimidazole, 4-methylimidazole and 4-methyl-2-phenylimidazole; pyridine, 2-methylpyridine, 4-methylpyridine, 2- Ethyl pyridine, 4-ethyl pyridine, 2-phenyl pyridine, 4-phenyl pyridine, N
Pyridines such as -methyl-4-phenylpyridine, nicotine, nicotinic acid, nicotinamide, quinoline, 8-oxyquinoline, and acridine; pyrazine, pyrazole, pyridazine, quinosaline, purine, pyrrolidine, piperidine, morpholine, Methyl morpholine,
Examples thereof include piperazine, 1,4-dimethylpiperazine and 1,4-diazabicyclo [2.2.2] octane.

Among these nitrogen-containing organic compounds, the nitrogen-containing compound (I) and the nitrogen-containing heterocyclic compound are preferable. Also,
Among the nitrogen-containing compounds (I), trialkylamines are particularly preferable, and among the nitrogen-containing heterocyclic compounds, pyridines are particularly preferable. In the present invention, the acid diffusion controller is
They can be used alone or in combination of two or more. The amount of the acid diffusion controller used in the present invention is usually 15 parts by weight or less, preferably 0.00 parts by weight, per 100 parts by weight of the total of the (A) copolymer and the (B) alkali-soluble resin.
It is 1 to 10 parts by weight, and more preferably 0.005 to 5 parts by weight. 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. If the amount of the acid diffusion control agent used is less than 0.001 part by weight, the pattern shape and dimensional fidelity may decrease depending on the process conditions.

Various Additives Further, the radiation-sensitive resin composition of the present invention may 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 a surfactant include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene octylphenyl ether,
In addition to polyoxyethylene nonyl phenyl ether, polyethylene glycol dilaurate, polyethylene glycol distearate, F top EF as a commercial product
301, EF303, EF352 (manufactured by Tochem Products), Megafac F171, F172, F173
(Manufactured by Dainippon Ink and Chemicals, Inc.), Florard FC4
30, FC431 (Sumitomo 3M Limited), Asahi Guard AG710, Surflon S-382, SC-10
1, SC-102, SC-103, SC-104, SC
-105, SC-106 (Asahi Glass Co., Ltd.), KP34
1 (manufactured by Shin-Etsu Chemical Co., Ltd.), Polyflow No. 75,
No. 95 (manufactured by Kyoeisha Yushi Kagaku Kogyo KK) and the like. The content of the surfactant is usually 2 parts by weight or less per 100 parts by weight of the total solid content of the radiation-sensitive resin composition. The sensitizer has the function of absorbing the energy of radiation and transmitting the energy to the (C) radiation-sensitive acid generator, thereby increasing the amount of acid produced by exposure, and is used as a resist. It has an effect of improving apparent sensitivity. Preferred sensitizers include, for example, ketones, benzenes, acetophenones, benzophenones, naphthalenes, biacetyls, eosin, rose bengal, pyrenes, anthracenes, phenothiazines and the like. The compounding amount of the sensitizer is usually 50 parts by weight or less, preferably 30 parts by weight or less, per 100 parts by weight of the total solid content of the radiation-sensitive resin composition. Further, 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 mitigated. By blending an adhesion aid,
The adhesion with the substrate can be improved. Furthermore, as other additives, an antihalation agent such as 4-hydroxy-4′-methylchalcone, a storage stabilizer, and a defoaming agent can be added.

Solvent When the radiation-sensitive resin composition of the present invention is used,
By uniformly dissolving in a solvent so that the concentration of the total solid content is, for example, usually 5 to 50% by weight, preferably 15 to 40% by weight, and then filtering with a filter having a pore size of about 0.2 μm. , A composition solution. The solvent used in the preparation of the composition solution,
For example, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate and other ethylene glycol monoalkyl ether acetates; propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene Propylene glycol monoalkyl ether acetates such as glycol monopropyl ether acetate and propylene glycol monobutyl ether acetate; Lactic acid esters such as methyl lactate, ethyl lactate, propyl lactate and butyl lactate; methyl acetate, ethyl acetate, propyl acetate, butyl acetate, Amyl acetate, hexyl acetate, propion Methyl, ethyl propionate,
Aliphatic carboxylic acid esters such as propyl propionate; methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate,
Other esters such as ethyl 3-ethoxypropionate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, methyl pyruvate and ethyl pyruvate; aromatic hydrocarbons such as toluene and xylene; 2
-Keptanes such as heptanone, 3-heptanone, 4-heptanone and cyclohexanone; amides such as N, N-dimethylformamide and N-methylpyrrolidone; and lactones such as γ-butyrolactone. These solvents are used alone or in admixture of two or more. The amount of the solvent used is usually 20 to 3,000 parts by weight, based on 100 parts by weight of the total solid content of the radiation-sensitive resin composition,
It is preferably 50 to 3,000 parts by weight, more preferably 100 to 2,000 parts by weight.

Method of forming 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 spin-coated, cast-coated, roll-coated, etc. To form a resist film by applying on a substrate such as a silicon wafer or a wafer covered with aluminum by an appropriate applying means, and optionally pre-baking it to form a predetermined resist pattern. Then, the resist film is exposed. The radiation used at that time is a KrF excimer laser (wavelength 248 n).
m) is used. Further, the exposure conditions such as the exposure amount are appropriately selected according to the composition of the composition and the like. In the present invention, in order to improve the apparent sensitivity of the resist film, it is preferable to perform a heat treatment after exposure (hereinafter referred to as “post-exposure bake”). The heating conditions vary depending on the composition of the composition, etc., but are usually 30 to 200 ° C.,
Preferably it is 40-150 degreeC. Further, when forming a resist pattern, a protective film may be provided on the resist film in order to prevent the influence of basic impurities contained in the environmental atmosphere. Then, the exposed resist film is developed with an alkali developing solution to form a predetermined resist pattern. Examples of the alkaline developer include alkali metal hydroxides; ammonia water; mono-, di- or tri-alkylamines; mono-, di- or tri-alkanolamines; heterocyclic amines; tetraalkylammonium. Hydroxide; choline; 1,8-diazabicyclo- [5,4,0] -7-undecene, 1,5-diazabicyclo- [4,3,0]-
At least one kind of alkaline compound such as 5-nonene,
Usually, an alkaline aqueous solution which is dissolved to have a concentration of 1 to 10% by weight, preferably 2 to 5% by weight is used.
In addition, a proper amount of a water-soluble organic solvent such as methanol or ethanol or a surfactant can be added to the developer containing the alkaline aqueous solution. When a developer composed of an alkaline aqueous solution is used, washing is generally performed after development.

[0031]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described with reference to Examples.
The embodiment will be described more specifically. However, the present invention
Are not limited to these examples in any way. This
Here, “part” is based on weight. Examples and comparative examples
Mw and Mn (Mw / Mn) and wavelength of 248 nm
Measurement of light transmittance and evaluation of each resist in
I went as follows.Mw and Mn (Mw / Mn) Tosoh GPC column (G2000H_XL Two,
G3000H_XL 1 piece, G4000H_XL For 1)
Flow rate 1.0 ml / min, elution solvent tetrahydride
Under the analysis conditions of lofran and column temperature of 40 ° C, monodisperse po
Gel permeation chromatography with styrene as standard
It was measured by graphography (GPC).T ₂₄₈  A 2-inch diameter quartz wafer is coated with an alkali-soluble resin
Ropylene glycol monomethyl ether acetate solution
Is spin coated and baked at 90 ° C for 60 seconds to give a film thickness of 1
An alkali-soluble resin film of μm was obtained, and this wafer was
UV spectrum meter U321 made by Hitachi, Ltd.
It was measured using 0.Developability A line width 0.26 μm line formed on a silicon wafer.
Square-shaped cut-and-space pattern (1L1S)
The surface is observed using a scanning electron microscope and evaluated according to the following criteria.
I paid. ◯: No development residual is observed between patterns; Δ: Partial development residual is observed between patterns; X: Development residual between patterns is remarkable.sensitivity Exposed to a resist film formed on a silicon wafer
After that, immediately post-exposure bake, then alkali development
Develop with liquid, wash with water, dry and shape resist pattern
When formed, 1L1S with a line width of 0.26 μm is a one-to-one line
The exposure amount to be formed in the width is 0.26Eop, and this value
The sensitivity was evaluated more. Also, at 25 ° C after the composition solution is prepared
After storing for 3 months, the sensitivity is evaluated again in the same manner as above.
I paid. resolution A resist pattern that is resolved when exposed at 0.26 Eop
The minimum dimension (μm) of the turn was the resolution.Pattern shape 1L with a line width of 0.26μm formed on a silicon wafer
The lower side dimension La and the upper side dimension Lb of the pattern cross section of 1S
Was measured by a scanning electron microscope, and 0.9 <Lb / L
When a <1.1, the pattern shape is good; 0.9 ≧ Lb
When / La, the pattern shape is round top; Lb /
When La ≧ 1.1, the pattern shape is T-top
evaluated.

(A) Synthesis of Copolymer Synthesis Example-1 500 g of p-t-butoxystyrene and 500 g of propylene glycol monomethyl ether were placed in a 2 liter separable flask, and 25 g of azobisisobutyronitrile and t-dodecyl were added. 2.5 g of mercaptan was added and polymerized at 75 ° C. for 8 hours. Then, the obtained polymerization solution was washed with a mixed solution of hexane, methanol and water,
Low molecular weight components were removed. Then, the solvent was replaced with propylene glycol, 10 wt% sulfuric acid was added, and the mixture was reacted at 90 ° C. for 6 hours to remove the t-butyl group in the polymer,
Poly (p-hydroxystyrene) was prepared, and this polymer solution was poured into a large amount of water for reprecipitation and then dried overnight in a vacuum dryer at 50 ° C. to obtain a polymer powder. When the molecular weight of the obtained polymer was measured by GPC,
Mw = 8,800 and Mw / Mn = 1.52. This polymer is referred to as a polymer (a-1).

Synthesis Example-2 500 g of pt-butoxystyrene and 500 g of tetrahydrofuran were placed in a 2 liter separable flask, cooled to -15 ° C., and polymerized with n-butyllithium as a polymerization initiator for 1 hour. The reaction was stopped by adding methanol. After that, the obtained polymerization solution was used in Synthesis Example-
The same procedure as in Example 1 was performed to remove the t-butyl group in the polymer to obtain poly (p-hydroxystyrene), and then the same operation as in Synthesis Example-1 was performed to obtain a polymer powder. The obtained polymer has Mw = 15,500 and Mw / Mn =
It was 1.08. This polymer is referred to as polymer (a-2)
And

Synthesis Example-3 450 g of pt-butoxystyrene, 30 g of styrene and 500 g of propylene glycol monomethyl ether.
Was placed in a 2 liter separable flask, 18 g of azobisisobutyronitrile was added, and polymerization was carried out at 70 ° C. for 8 hours. Then, the obtained polymerization solution was treated in the same manner as in Synthesis Example-1 to remove the t-butyl group in the polymer to give p-
After forming a hydroxystyrene-styrene copolymer, a polymer powder was obtained by the same operation as in Synthesis Example-1.
The obtained polymer has Mw = 13,500, Mw / Mn
= 1.44, and as a result of ¹³ C-NMR measurement, 4-
The copolymerization ratio of hydroxystyrene and styrene was 89:11. This polymer is referred to as a polymer (a-3).

Synthesis Example-4 24 g of the polymer (a-1) was dissolved in 100 ml of dioxane, and then nitrogen was bubbled for 30 minutes. To this solution, 5 g of ethyl vinyl ether and 1 g of p-toluenesulfonic acid pyridinium salt as a catalyst were added and reacted for 12 hours. After the reaction, 1% by weight aqueous ammonia was added dropwise to precipitate a polymer, which was dried overnight in a vacuum dryer at 50 ° C. The obtained polymer has Mw = 1.
0,300, Mw / Mn = 1.55, and ¹³ C-
As a result of NMR measurement, 3 of the hydrogen atoms of the phenolic hydroxyl group
It was a polymer having a structure in which 4 mol% was substituted with 1-ethoxyethyl groups. This polymer is a copolymer (A
-1).

Synthesis Examples-5 to 10 Using the raw material polymers shown in Table 1 and vinyl ether in the proportions shown in Table 1, the reaction was carried out in the same manner as in Synthesis Example-4,
Copolymers (A-2) to (A-7) were obtained.

[0037]

【Example】

Examples 1 to 9 and Comparative Example 1 The components shown in Table 2 were mixed to form a uniform solution, which was then filtered through a membrane filter having a pore size of 0.2 μm to prepare a composition solution. After that, each composition solution was spin-coated on a silicon wafer, and then prebaked at 90 ° C. for 120 seconds using a hot plate to obtain a film thickness of 1.
A 0 μm resist film was formed. Then, KrF excimer laser stepper (NSR-20 manufactured by Nikon Corporation)
05 EX8A), and then post-exposure bake was performed at 110 ° C. for 120 seconds using a hot plate. Then, using a 2.38 wt% tetramethylammonium hydroxide aqueous solution, development was performed by a dipping method at 23 ° C. for 1 minute, followed by washing with pure water and drying to form a resist pattern. Table 3 shows the evaluation results of the obtained resist patterns. Here, the (B) alkali-soluble resin, (C) acid generator, acid diffusion control agent and solvent in each example are as follows. (B) Alkali-soluble resin B-1: Polymer (a-1) obtained in Synthesis Example-1, T ₂₄₈ =
71% B-2: Polymer (a-3) obtained in Synthesis Example-3, T ₂₄₈ =
75% (C) Acid generator C-1: triphenylsulfonium triflate C-2: N- (camphanylsulfonyloxy) naphthyldicarboximide C-3: bis (cyclohexylsulfonyl) diazomethanoic acid diffusion controller a: nicotine Acid Amido: Trioctylamine Solvent PGMEA: Propylene glycol monomethyl ether acetate MMP: Methyl 3-methoxypropionate

[0038]

[Table 1]

[0039]

[Table 2]

[0040]

[Table 3]

[0041]

The radiation-sensitive resin composition of the present invention has a Kr
It is sensitive to F excimer laser (wavelength 248nm), has very little influence of standing waves, has an excellent pattern shape, and has an excellent balance of characteristics including sensitivity, resolution, developability, focus tolerance, etc. The fine resist pattern can be stably formed. Therefore, the radiation-sensitive resin composition of the present invention can be very suitably used as a chemically amplified resist for semiconductor device production, which is expected to be further miniaturized in the future.

Embedded image

Embedded image

Claims (1)

[Claims] 1. A copolymer containing (A) a repeating unit represented by the following formula (1) and a repeating unit represented by the following formula (2): [Formula 1] [in the formula (1), R ¹ represents a hydrogen atom or a methyl group. ] [In the formula (2), R ² represents a hydrogen atom or a methyl group, R ³ represents a hydrogen atom, a chain alkyl group having 1 to 10 carbon atoms, or a cyclic alkyl group having 3 to 10 carbon atoms. , Carbon number 6 ~
Represents an aryl group having 10 or an aralkyl group having 7 to 11 carbon atoms, and R ⁴ and R ⁵ each independently have 1 to 10 carbon atoms.
Chain alkyl group, halogenated chain alkyl group having 1 to 10 carbon atoms, cyclic alkyl group having 3 to 10 carbon atoms, and 6 carbon atoms
10 represents an aryl group or aralkyl group having 7 to 11 carbon atoms, or any two of R ³ , R ⁴ and R ⁵ are bonded to each other to form a 5 to 7 membered ring. ], (B)
The light transmittance at a wavelength of 248 nm is 5 per 1 μm of film thickness.
A radiation-sensitive resin composition comprising 0% or more of an alkali-soluble resin and (C) a radiation-sensitive acid generator.