JP2002287363A - Chemically amplifying positive resist composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chemically amplifying positive resist composition excellent in sensitivity and resolution and improved in the problem of scum. SOLUTION: The chemically amplifying positive resist composition contains the following resin, a radiation-sensitive acid producing agent and polypropylene glycol. The resin has polymer units derived from hydroxylstyrene and polymer units derived from 2-ethyl-2-adamantyl (meth)acrylates and the resin itself is insoluble or hardly soluble with an alkali aqueous solution but becomes soluble with an alkali aqueous solution after groups unstable to acids are separated by the effect of acids.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resist composition suitable for lithography and the like, which is operated by high-energy radiation such as deep ultraviolet rays (including excimer lasers), electron beams, X-rays or radiation. is there.

[0002]

2. Description of the Related Art In recent years, with the increase in the degree of integration of integrated circuits, submicron pattern formation has been required. In particular, lithography using a radiation source such as krypton fluoride (KrF), argon fluoride (ArF), excimer laser light from fluorine (F ₂ ), electron beam, EUV light, or X-ray can form a fine pattern. Attention has been paid to Utilizing acid catalyst and chemical amplification effect as a resist suitable for lithography process,
A so-called chemically amplified resist is used. In the chemically amplified resist, the acid generated from the acid generator in the irradiated portion is subjected to a subsequent heat treatment (post exposure).
bake (hereinafter sometimes abbreviated as PEB), and changes the solubility of the irradiated portion in an alkali developing solution by a reaction using the acid as a catalyst, whereby a positive or negative pattern is formed. give.

In a chemically amplified positive resist, a resin in which an alkali-soluble group is protected by a group which is cleaved by the action of an acid is often used in combination with an acid generator. Such a group that is cleaved by the action of an acid is particularly S. Takechi
et al., J. Photopolym. Sci.Technol., Vol. 9, No. 3,
Use of a protecting group such as a 2-alkyl-2-adamantyl group or a 1-adamantyl-1-alkylalkyl group as described in 475-487 (1996) and JP-A-9-73173 provides high resolution and high resolution. It is reported that good dry etching resistance can be obtained. Nozaki et al., J. Ph
otopolym.Sci. Technol., Vol.13, No.3, 397-403 (20
In (00), an electron beam resist using 2-methyl-2-adamantyl methacrylate or a copolymer resin of 2-ethyl-2-adamantyl methacrylate and hydroxystyrene is shown, and in particular, 2-ethyl methacrylate is used.
Those using a copolymer resin of 2-adamantyl and hydroxystyrene have high sensitivity and excellent etching resistance.
It has been reported that high resolution can be obtained even with rF excimer laser exposure.

However, 2-ethyl methacrylate-
A chemically amplified positive resist using a copolymer resin of 2-adamantyl and hydroxystyrene has a problem that scum is generated after development.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a chemically amplified positive resist composition having excellent sensitivity and resolution and improved scum.

The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, by using a specific copolymer as a resin component of a chemically amplified positive resist and further containing polypropylene glycol, It has been found that excellent performance can be obtained without scum, and the present invention has been completed.

[0007]

That is, the present invention has a polymerized unit derived from hydroxystyrene and a polymerized unit derived from 2-ethyl-2-adamantyl (meth) acrylate, and is itself insoluble in an aqueous alkali solution. Or, it is hardly soluble, but is characterized by containing a resin, a radiation-sensitive acid generator, and polypropylene glycol which become soluble in an aqueous alkali solution after the acid-labile group is cleaved by the action of an acid. And a chemically amplified positive resist composition.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The resin component in the resist composition of the present invention is insoluble or poorly soluble in an aqueous alkali solution by itself, but undergoes a chemical change by the action of an acid to become alkali-soluble, and is derived from hydroxystyrene. It essentially has at least two kinds of polymerized units and polymerized units derived from 2-ethyl-2-adamantyl (meth) acrylate. These polymerized units are formed by opening the double bond of the styrene portion and the double bond of the (meth) acrylic acid portion, and are specifically formed by the following formulas (I) and (II), respectively. ).

[0009]

[0010] In the formula (II), R ¹ represents a hydrogen atom or a methyl group, and R ² represents an ethyl group.

In the hydroxystyrene unit represented by the formula (I), the positional relationship between the hydroxyl group and the vinyl group is not particularly limited, but is generally p-hydroxystyrene.

A resin having a polymerized unit derived from hydroxystyrene and a polymerized unit derived from 2-ethyl-2-adamantyl (meth) acrylate can be produced, for example, as follows. First, it can be produced by copolymerizing acetoxystyrene and 2-ethyl-2-adamantyl (meth) acrylate by a conventional method, and then appropriately hydrolyzing to change part or all of the acetoxy group to a hydroxyl group.

The copolymerization of hydroxystyrene or acetoxystyrene with 2-ethyl-2-adamantyl (meth) acrylate and, optionally, monomers having acid-labile groups and / or other monomers, It can be performed according to a conventional method. For example, a method in which a raw material monomer is dissolved in an appropriate solvent, a polymerization initiator is added thereto to initiate polymerization, and the reaction is continued under heating or heat removal can be adopted. Examples of the reaction solvent include alcohols such as methanol, ethanol, 2-propanol and tert-butanol, benzene, toluene, aromatic hydrocarbons such as xylene, tetrahydrofuran, and ethers such as 1,4-dioxane. Can be used. Examples of the polymerization initiator include azo compounds such as 2,2'-azobis (isobutyronitrile) and dimethyl 2,2'-azobis (2-methylpropionate), benzoyl peroxide, and tert-butyl peroxide. And redox initiators such as benzoyl peroxide / dimethylaniline, and metal alkylates such as butyllithium and triethylaluminum.

The resin component constituting the positive resist composition of the present invention comprises a polymer unit derived from hydroxystyrene and a polymer unit derived from 2-ethyl-2-adamantyl (meth) acrylate as described above. It is essential to have, but it may contain other polymerized units, for example, polymerized units derived from styrene, acrylonitrile, methyl methacrylate, methyl acrylate, and the like. Further, in order to improve the transparency, the phenol nucleus may be partially hydrogenated, or an alkyl group, an alkoxy group, or the like may be introduced into the phenol nucleus within a range that is soluble in an aqueous alkali solution. However, it is advantageous that the total of the polymer units derived from hydroxystyrene and the polymer units derived from 2-ethyl-2-adamantyl (meth) acrylate account for at least 50 mol% of the whole resin. . The ratio of both polymerization units is usually in the range of 99: 1 to 60:40, preferably in a molar ratio of polymerization units derived from hydroxystyrene: polymerization units derived from 2-ethyl-2-adamantyl (meth) acrylate. 9
The range is 5: 5 to 70:30. The amount of the polymerized unit having an acid-labile group is usually 50 mol% or less, preferably 10 mol% or more and 45 mol% or less.

Next, the acid generator, which is another component of the positive resist composition, is prepared by applying radiation such as light or electron beam to the substance itself or the resist composition containing the substance. The substance is decomposed to generate an acid. The acid generated from the acid generator acts on the resin to cleave the acid-labile groups present in the resin. Such acid generators include, for example, onium salt compounds, s-triazine-based organic halogen compounds, sulfone compounds, sulfonate compounds, and the like. Specifically, the following compounds can be mentioned.

Diphenyliodonium trifluoromethanesulfonate, 4-methoxyphenylphenyliodonium hexafluoroantimonate, 4-methoxyphenylphenyliodonium trifluoromethanesulfonate, bis (4-tert-butylphenyl) iodonium tetrafluoroborate, bis (4-tert-
Butylphenyl) iodonium hexafluorophosphate, bis (4-tert-butylphenyl) iodonium hexafluoroantimonate, bis (4-tert-
Butylphenyl) iodonium trifluoromethanesulfonate,

Triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium 2,4,6-triisopropylbenzenesulfonate 4-methylphenyldiphenylsulfonium perfluorobutanesulfonate, 4 -Methylphenyldiphenylsulfonium perfluorooctanesulfonate, 4-methoxyphenyldiphenylsulfonium
Hexafluoroantimonate, 4-methoxyphenyldiphenylsulfonium trifluoromethanesulfonate, p-tolyldiphenylsulfonium trifluoromethanesulfonate, 2,4,6-trimethylphenyldiphenylsulfonium trifluoromethanesulfonate, 4-tert-butylphenyldiphenylsulfonium trifluoromethanesulfonate, 4-phenylthiophenyldiphenylsulfonium hexafluorophosphate, 4-phenylthiophenyldiphenylsulfonium hexafluoroantimonate, 1- (2
-Naphthoylmethyl) thiolanium hexafluoroantimonate, 1- (2-naphthoylmethyl) thiolanium trifluoromethanesulfonate, 4-hydroxy-1-naphthyldimethylsulfonium hexafluoroantimonate, 4-hydroxy-1-naphthyldimethylsulfonium trifluoromethane Sulfonate,

2-methyl-4,6-bis (trichloromethyl) -1,3,5-triazine, 2,4,6-tris (trichloromethyl) -1,3,5-triazine, 2-
Phenyl-4,6-bis (trichloromethyl) -1,3,
5-triazine, 2- (4-chlorophenyl) -4,6
-Bis (trichloromethyl) -1,3,5-triazine, 2- (4-methoxyphenyl) -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- (4
-Methoxy-1-naphthyl) -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- (benzo [d] [1,3] dioxolan-5-yl) -4,6-
Bis (trichloromethyl) -1,3,5-triazine,
2- (4-methoxystyryl) -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- (3
4,5-trimethoxystyryl) -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- (3
4-dimethoxystyryl) -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- (2,4-dimethoxystyryl) -4,6-bis (trichloromethyl) -1,3,5 -Triazine, 2- (2-methoxystyryl) -4,6-bis (trichloromethyl) -1,3,
5-triazine, 2- (4-butoxystyryl) -4,
6-bis (trichloromethyl) -1,3,5-triazine, 2- (4-pentyloxystyryl) -4,6-bis (trichloromethyl) -1,3,5-triazine,

1-benzoyl-1-phenylmethyl p
-Toluenesulfonate (commonly called benzoin tosylate), 2-benzoyl-2-hydroxy-2-phenylethyl p-toluenesulfonate (commonly called α-methylol benzoin tosylate), 1,2,3-benzenetriyl trismethanesulfonate, , 6-Dinitrobenzyl p-toluenesulfonate, 2-nitrobenzyl p-toluenesulfonate, 4-nitrobenzyl
p-toluenesulfonate,

Diphenyl disulfone, di-p-tolyl disulfone, bis (phenylsulfonyl) diazomethane, bis (4-chlorophenylsulfonyl) diazomethane, bis (p-tolylsulfonyl) diazomethane, bis (4-tert-butylphenylsulfonyl) diazomethane, Bis (4-tert-butylsulfonyl) diazomethane, bis (2,4-xylylsulfonyl) diazomethane, bis (cyclohexylsulfonyl) diazomethane,
(Benzoyl) (phenylsulfonyl) diazomethane,

N- (phenylsulfonyloxy) succinimide, N- (trifluoromethylsulfonyloxy) succinimide, N- (trifluoromethylsulfonyloxy) phthalimide, N- (trifluoromethylsulfonyloxy) -5-norbornene-2, 3-dicarboximide, N- (trifluoromethylsulfonyloxy) naphthalimide, N- (10-camphorsulfonyloxy) naphthalimide,

(5-propylsulfonyloxyimino-
5H-thiophen-2-ylidene)-(2-methylphenyl) acetonitrile, (5-toluylsulfonyloxyimino-5H-thiophen-2-ylidene)-(2-
(Methylphenyl) acetonitrile, (5-n-butylsulfonyloxyimino-5H-thiophen-2-ylidene)-(2-methylphenyl) acetonitrile, (5-
n-octylsulfonyloxyimino-5H-thiophen-2-ylidene)-(2-methylphenyl) acetonitrile and the like.

Next, the polypropylene glycol, which is another component of the positive resist composition of the present invention, is present in the resin when an acid generated by light and heat from an acid generator acts on the resin. When cleaving an acid-labile group, it promotes the generation of acid and the cleavage of acid-labile group,
The occurrence of scum can be prevented. The content of the polypropylene glycol used here is appropriately selected according to the type of the photoresist composition, but is 0.1 to 5% by weight based on the solid content in the resist. Further, the molecular weight of the polypropylene glycol in the present invention is appropriately selected according to the type of the photoresist composition, and usually has a weight average molecular weight of 500 or more and 5000 or less.

Further, by adding a basic compound, particularly a basic nitrogen-containing organic compound such as an amine, to the resist composition of the present invention as a quencher, the acid can be deactivated due to withdrawal after irradiation. Performance degradation can be improved. In the present invention, specific examples of the basic compound used for the quencher include those represented by the following formulas.

[0025]

[0026]

Where R¹¹And R¹²Is independent of the water
Alkyl, cycloalkyl optionally substituted by hydroxyl,
Alkyl or aryl;¹³, R¹⁴And R¹⁵Are each other
Independently, an alkyl optionally substituted with hydrogen or a hydroxyl group
Represents cycloalkyl, aryl or alkoxy,
R¹⁶Is an alkyl or cycloalkyl which may be substituted with a hydroxyl group.
A represents alkyl, alkylene, carbo
Nil, imino, disulfide, sulfide or secondary amino
Represents R¹¹~ R¹⁶Alkyl and R represented by ¹³~ R
¹⁵The alkoxy represented by each has about 1 to 6 carbon atoms
And R¹¹~ R¹⁶Cycloalkyl represented by
Can have about 5 to 10 carbon atoms, and R
¹¹~ R¹⁵Is an aryl group having about 6 to 10 carbon atoms.
There can be. The alkylene represented by A is
It can have about 1 to 6 carbon atoms, and can be branched
It may be.

Furthermore, a hindered amine compound having a piperidine skeleton as disclosed in JP-A-11-52575 can be used as the quencher.

The resist composition of the present invention contains 80 to 99.8% by weight of a resin component and 0.1 to 20% by weight of an acid generator based on the total solid content therein. preferable. When a nitrogen-containing basic organic compound as a quencher is contained, it is preferably used in an amount of 10% by weight or less based on the total solid content in the resist composition. The composition may also contain small amounts of various additives such as sensitizers, dissolution inhibitors, other resins, surfactants, stabilizers, and dyes, if necessary.

This resist composition is usually used as a resist solution in a state where the above-mentioned components are dissolved in a solvent, and applied to a substrate such as a silicon wafer by a conventional method such as spin coating. The solvent used here may be any as long as it dissolves each component, has an appropriate drying rate, and gives a uniform and smooth coating film after evaporation of the solvent, and is commonly used in this field. be able to. For example, glycol ether esters such as ethyl cellosolve acetate, methyl cellosolve acetate and propylene glycol monomethyl ether acetate, esters such as ethyl lactate, butyl acetate, amyl acetate and ethyl pyruvate, acetone, methyl isobutyl ketone, 2-heptanone Ketones such as cyclohexanone, cyclic esters such as γ-butyrolactone,
Examples include alcohols such as 3-methoxy-1-butanol. These solvents can be used alone or in combination of two or more.

The resist film applied and dried on the substrate is subjected to an exposure treatment for patterning, and then to a heat treatment (PEB) for accelerating the deprotection reaction, and then to an alkali developing solution. Is developed. The alkaline developer used here can be various alkaline aqueous solutions used in this field, but generally, aqueous solutions of tetramethylammonium hydroxide and (2-hydroxyethyl) trimethylammonium hydroxide (commonly known as choline) are used. Often used.

[0032]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the present invention. In the examples, percentages and parts representing the content or the used amount are based on weight unless otherwise specified. Also,
Weight average molecular weight (Mw) and polydispersity (Mw / Mn)
Is a value measured by gel permeation chromatography using polystyrene as a standard.

(1a) 2-ethyl-2-adamantyl methacrylate and p-acetoxystyrene copolymer (20:
80) Synthesis In a flask, 39.7 g (0.16 mol) of 2-ethyl-2-adamantyl methacrylate, 103.8 g (0.64 mol) of p-acetoxystyrene and isopropanol 26 were added.
5 g was charged and replaced with nitrogen, and the temperature was raised to 75 ° C. To this solution, 11.05 g (0.048 mol) of dimethyl 2,2'-azobis (2-methylpropionate) was dissolved in 22.11 g of isopropanol, and then added dropwise. 75
After aging for about 0.3 hours at reflux and about 12 hours under reflux,
It was diluted with CT, charged into methanol, crystallized, and the crystals were taken out by filtration. The obtained methacrylic acid 2
Crude crystals of a copolymer of -ethyl-2-adamantyl and p-acetoxystyrene were 250 g.

(1b) 2-ethyl-2-adamantyl methacrylate and p-hydroxystyrene copolymer (20:
Synthesis of 80) In a flask, 250 g of crude crystals of a copolymer (20:80) of 2-ethyl-2-adamantyl methacrylate and p-acetoxystyrene obtained in (1a) and 4-dimethylaminopyridine 10 0.3 g (0.084 mol) and 202 g of methanol were charged and aged for 20 hours under reflux. After cooling, the mixture was neutralized with 7.6 g (0.126 mol) of glacial acetic acid, charged into water, crystallized, and crystals were taken out by filtration. Thereafter, the crystals were dissolved in acetone, charged in water, crystallized, and the crystals were taken out by filtration. This operation was repeated three times in total, and the obtained crystals were dried. The obtained 2-ethyl-2-adamantyl methacrylate and p-
The weight of crystals of the copolymer with hydroxystyrene was 95.9 g. The weight average molecular weight was about 8,600, the degree of dispersion was 1.65 (GPC method: converted to polystyrene), and the copolymerization ratio was about 2 by a nuclear magnetic resonance ( ^13C -NMR) spectrometer.
0:80 was determined. This resin is referred to as resin A.

(2a) 2-ethyl-2-adamantyl methacrylate and p-acetoxystyrene copolymer (30:
70) Synthesis In a flask, 59.6 g (0.24 mol) of 2-ethyl-2-adamantyl methacrylate, 90.8 g (0.56 mol) of p-acetoxystyrene and 279 of isopropanol were added.
g was charged and replaced with nitrogen, and the temperature was raised to 75 ° C. To this solution, 11.05 g (0.048 mol) of dimethyl 2,2'2-azobis (2-methylpropionate) was dissolved in 22.11 g of isopropanol, and then added dropwise. 75
After aging for about 0.3 hours at reflux and about 12 hours under reflux.
It was diluted with CT, charged into methanol, crystallized, and the crystals were taken out by filtration. The obtained methacrylic acid 2
Crude crystals of a copolymer of -ethyl-2-adamantyl and p-acetoxystyrene were 250 g.

(2b) 2-ethyl-2-adamantyl methacrylate and p-hydroxystyrene copolymer (30:
Synthesis of 70) 250 g of crude crystals of a copolymer (30:70) of 2-ethyl-2-adamantyl methacrylate and p-acetoxystyrene obtained in (2a) and 4-dimethylaminopyridine 10 were added to a flask. 0.8 g (0.088 mol) and 239 g of methanol were charged and aged for 20 hours under reflux. After cooling, the mixture was neutralized with 8.0 g (0.133 mol) of glacial acetic acid, charged into water, crystallized, and crystals were taken out by filtration. Thereafter, the crystals were dissolved in acetone, charged with water, crystallized, and the crystals were taken out by filtration. This operation was repeated three times in total, and the obtained crystals were dried. The obtained 2-ethyl-2-adamantyl methacrylate and p-
102.8 g of crystals of the copolymer with hydroxystyrene
Met. The weight average molecular weight was about 8200, the degree of dispersion was 1.68 (GPC method: converted to polystyrene), and the copolymerization ratio was about 3 using a nuclear magnetic resonance ( ^13C -NMR) spectrometer.
0:70 was determined. This resin is referred to as resin B.

Examples and Comparative Examples Resins obtained by mixing Resin A and Resin B at a solid content ratio of 1: 1 were used.
The resist solution was prepared by mixing and dissolving with an acid generator, a quencher and a solvent represented by I) and (IV) and filtering through a fluororesin filter having a pore diameter of 0.2 μm.

[0038]

[0039]

Resin (solid content): 13.5 parts Acid generator: Acid generator (III) 0.45 parts Acid generator (IV) 0.45 parts Quencher: diisopropyl aniline 0.055 parts Solvent: propylene glycol monomethyl ether acetate 90 parts ^* (solvent The amount includes the amount brought in from the resin solution.)

Examples 1 to 3 were obtained by adding 10% of a polypropylene glycol having a molecular weight shown in Table 1 to the solid content of the resin to this resist solution.

[0042]

[Table 1] 例 Example No. Molecular weight of polypropylene (weight average molecular weight) ━━━━━━━ ━━━━━━━━━━━━━━━━━━━━━ Example 1 1000 Example 2 2000 Example 3 3000 ─────────────────比較 Comparative Example 1 No addition ━━━━━━━━━━━━━━━━━━━━━━━━━━━━

An antireflection film (“DUV-42” manufactured by Nissan Chemical Industries, Ltd.) was applied to a silicon wafer to a thickness of 0.06 μm under a pre-bake condition at 215 ° C. for 60 seconds. Coat, then 110 ° C, 60
Prebaking was performed on a proximity hot plate under the condition of seconds to form a resist film having a thickness of 0.42 μm. The wafer on which the resist film was formed in this way,
KrF excimer stepper [“NSR” manufactured by Nikon Corporation
S203B ″, NA = 0.68, σ = 0.85, 2 /
Exposure through masks of various shapes and dimensions. Next, on a hot plate, 13
PEB is performed under the conditions of 0 ° C. and 60 seconds, and 2.38
60% aqueous solution of tetramethylammonium hydroxide
Paddle development was performed for 2 seconds. Observe the pattern after development with a scanning electron microscope, and determine the sensitivity, resolution,
The presence or absence of scum was examined, and the results are shown in Table 2.

Film drop sensitivity: The exposure was represented by the minimum exposure necessary for a 2 mm square open field to pass through the film. This is Eth.

Effective sensitivity: The exposure was such that a 0.13 μm line and space pattern was 1: 1. This is Eo.

Presence / absence of scum: The pattern-formed wafer was observed from above using a scanning electron microscope.
Exposed portions were examined for scum (residue) at an exposure amount at which the line and space pattern of 1 μm was 1: 1. When at least one scum was observed, it was evaluated as x, and when no scum was observed, it was evaluated as ○.

Resolution: The minimum size of the line and space pattern separated by the exposure amount of the effective sensitivity was displayed.

[0048]

TABLE 2 whether ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Example No. Molecular weight sensitivity resolution scum (mJ / cm ² ) (μm) Eth Eo 実 施 Example 1 1000 11 32 0.13 ○ Example 2 2000 11 32 0.13 ○ Example 3 3000 11 32 0.13 ○ ───────────────────────────────── ── Comparative Example 1 11 32 0.13 × ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

[0049]

The resist composition of the present invention has good sensitivity and resolution and does not generate scum. Therefore, by using this composition, a fine resist pattern can be accurately formed.

Continued on the front page (72) Inventor Yasunori Uetani 3-1-1, Kasuganaka, Konohana-ku, Osaka Sumitomo Chemical Co., Ltd. F-term (reference) 2H025 AA01 AA02 AB16 AC04 AC05 AC06 AC08 AD03 BE00 BE07 BE08 BG00 CC20 FA03 FA12 4J100 AB07P AL08Q BA03P BC09Q CA04 JA38

Claims (4)

[Claims] (1) It has a polymerized unit derived from hydroxystyrene and a polymerized unit derived from 2-ethyl-2-adamantyl (meth) acrylate, and is itself insoluble or hardly soluble in an aqueous alkali solution. Chemically-amplified positive resist composition comprising a resin which becomes soluble in an aqueous alkali solution after a group unstable to an acid is cleaved by the action of an acid, a radiation-sensitive acid generator, and polypropylene glycol . 2. The composition according to claim 1, wherein the content of the polypropylene glycol is 0.1 to 5% by weight based on the solid content in the resist composition. 3. The composition according to claim 2, wherein the weight average molecular weight of the polypropylene glycol is 500 or more and 5000 or less. 4. An onium salt compound, wherein the radiation-sensitive acid generator is an onium salt compound,
The composition according to any one of claims 1 to 3, comprising at least one compound selected from the group consisting of s-triazine-based organic halogen compounds, sulfone compounds and sulfonate compounds.