JP2002031891A - Positive type radiation sensitive composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a positive type radiation sensitive composition having high sensitivity and such resolution as to enable sub-quarter micron patterning. SOLUTION: The positive type radiation sensitive composition contains a polymer containing structural units of formulae (1) and (2) and an acid generating agent which generates an acid when irradiated with radiation. In the formula (1), X is a 1-6C alkyl, halogen or cyano and A is an organic group bonding to oxygen through tertiary carbon and containing an aromatic ring. In the formula (2), Y is a 1-6C alkyl, H, halogen or cyano, when X in the formula (1) is a 1-6C alkyl, B is a 2-16C organic group containing a secondary or tertiary alcoholic hydroxyl group, and when X in the formula (1) is halogen or cyano, B is a 1-16C organic group containing a primary, secondary or tertiary alcoholic hydroxyl group.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positive radiation-sensitive composition used for producing semiconductor integrated circuits, lithography masks and the like.

[0002]

2. Description of the Related Art In recent years, in fields such as the manufacture of semiconductor circuits and lithography masks, patterns have been miniaturized with an increase in the degree of integration. In order to realize this, a higher resolution resist material has been required, and it has become necessary to process a sub-quarter micron pattern of 0.25 μm or less with high sensitivity. Furthermore, it is difficult to perform such fine processing with a conventional lithography using a light source having a relatively long wavelength, and lithography using a far ultraviolet ray, an excimer laser, an X-ray and an electron beam having a shorter wavelength. Are being studied, and a resist corresponding to such a light source is required.

Conventionally, a resist using an acrylic polymer has been known as a resist corresponding to such a light source, and the main chain of the polymer is cut by exposure to light, and the molecular weight of the resist is reduced. This is a resist utilizing a changing mechanism.

In recent years, as a known resist material having characteristics of high sensitivity and high resolution, a chemically amplified resist has been actively studied. A chemically amplified resist is a resist having a mechanism in which an acid is generated in an exposed portion by the action of a photoacid generator, and the solubility of the exposed portion is changed by the catalytic action of the acid. Conventionally, among such chemically amplified resists showing relatively good resist performance, t-butoxycarbonyl group or t-butoxycarbonyloxy group is used as a resin component to protect an alkali-affinity group in an alkali-soluble resin. A resist using a protected resin, a resin similarly protected with a silyl group, a resin similarly protected with a ketal group, a resin similarly protected with an acetal group, a resin containing a (meth) acrylic acid component, and the like are known. .

Japanese Patent Application Laid-Open No. Hei 7-234511 discloses a chemically amplified resist using a resin containing hydroxyethyl methacrylate.

[0006]

However, the resolution and sensitivity of both the conventional main chain cleavage type and the chemically amplified type resists are opposite to each other, and the resolution for processing a sub-quarter micron pattern is required. There were drawbacks such as insufficient sensitivity to obtain.

[0007]

That is, the present invention comprises a polymer containing structural units represented by the following general formulas (1) and (2), and an acid generator which generates an acid upon irradiation with radiation. It is a positive-type radiation-sensitive composition.

[0008]

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(Where X represents any one of an alkyl group having 1 to 6 carbon atoms, a halogen element, and a cyano group;
Represents an organic group bonded to oxygen through a tertiary carbon and containing an aromatic ring. )

[0010]

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(Where Y represents an alkyl group having 1 to 6 carbon atoms, a hydrogen atom, a halogen element or a cyano group, and when X in the general formula (1) is an alkyl group having 1 to 6 carbon atoms) , B represents an organic group having 2 to 16 carbon atoms containing a secondary or tertiary alcoholic hydroxy group, and when X in the general formula (1) is either a halogen element or a cyano group, B is a primary group. Represents an organic group having 1 to 16 carbon atoms containing a secondary or tertiary alcoholic hydroxy group.)

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below.

The inventors of the present invention have studied a polymer for a chemically amplified resist capable of obtaining high resolution and high sensitivity. As a result, a specific α-substituted acrylate monomer structural unit and α It has been found that high resolution and high sensitivity can be realized by using a polymer containing a substituted acrylate-based monomer structural unit. By using such a polymer, in addition to the chemical amplification mechanism, a pattern can be formed by efficient main chain cleavage, and a high-sensitivity, high-resolution pattern can be obtained. Further, the adhesion to the silicon wafer is improved.

The polymer used in the positive radiation-sensitive composition of the present invention contains a structural unit represented by the general formula (1). X in the general formula (1) represents any of an alkyl group having 1 to 6 carbon atoms, a halogen element, and a cyano group. Examples of the alkyl group represented by X in the general formula (1) include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and a trifluoromethyl group. Examples of the halogen element represented by X in the general formula (1) include iodine, bromine, chlorine, fluorine and the like.

A in the general formula (1) may be any monovalent organic group having a tertiary carbon bonded to oxygen and containing an aromatic ring. The group represented by (3) is preferably used.

[0016]

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(Here, R ₁ , R ₂ , and R ₃ may be the same or different from each other, and may be an optionally substituted alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted alkyl group having 6 to 15 carbon atoms. Represents an aryl group or an optionally substituted aralkyl group having 7 to 16 carbon atoms, provided that R ₁ , R ₂ ,
None of R ₃ is simultaneously an alkyl group. Specific examples of R ₁ , R ₂ , and R ₃ include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group,
t-butyl group, trifluoromethyl group, trichloromethyl group, 2,2,2-trifluoroethyl group, 2,2,2
-Trichloroethyl group, cyclohexyl group, phenyl group, o-tolyl group, m-tolyl group, p-tolyl group, 2,
4-xylyl group, 3,5-xylyl group, o-chlorophenyl group, m-chlorophenyl group, p-chlorophenyl group, o-hydroxyphenyl group, m-hydroxyphenyl group, p-hydroxyphenyl group, benzyl group, phenethyl group , A naphthyl group, a p-methoxyphenyl group, a t-butoxycarbonyloxyphenyl group, a tetrahydropyranyloxyphenyl group, and the like.

The copolymerization ratio in the polymer having the structure represented by the general formula (1) is not particularly limited.
0 mol% to 99 mol% is preferable, and 50 mol% is more preferable.
Mol% to 95 mol%.

The polymer used in the positive radiation-sensitive composition of the present invention contains a structural unit represented by the general formula (2) in addition to the structure represented by the general formula (1). Is the feature. Y in the general formula (2) represents any of an alkyl group having 1 to 6 carbon atoms, a hydrogen atom, a halogen element, and a cyano group. Examples of the alkyl group represented by Y in the general formula (2) include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and a trifluoromethyl group. Examples of the halogen element represented by Y in the general formula (2) include iodine, bromine, chlorine, fluorine and the like.

B in the general formula (2) represents a secondary or tertiary group when X in the general formula (1) is an alkyl group having 1 to 6 carbon atoms.
2 to 1 carbon atoms containing a lower alcoholic hydroxy group
An organic group having 1 to 16 carbon atoms containing a primary, secondary or tertiary alcoholic hydroxy group, wherein X in the general formula (1) represents either a halogen element or a cyano group; Is represented. Specific examples thereof include a hydroxymethyl group, a 1-hydroxyethyl group, a 2-hydroxyethyl group, a 1-hydroxypropyl group, a 2-hydroxypropyl group, a 3-hydroxypropyl group, a 1-hydroxy-1-methylethyl group, -Hydroxy-1-methylethyl group, 1-hydroxybutyl group, 2-hydroxybutyl group, 3-hydroxybutyl group, 4-hydroxybutyl group, 1-hydroxy-1-methylpropyl group, 2-
Hydroxy-1-methylpropyl group, 1-hydroxy-
2-methylpropyl group, 2-hydroxy-2-methylpropyl group, 2-hydroxy-1,1-dimethylethyl group, 1,2-dihydroxypropyl group, 2,3-dihydroxypropyl group, 2,3-dihydroxybutyl Groups, or the following:

[0021]

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The copolymerization ratio in the polymer having the structure represented by the general formula (2) is not particularly limited.
The molar ratio is preferably from 60 mol% to 60 mol%, more preferably from 5 mol% to 50 mol%.

The polymer used in the present invention has the general formula (1)
And a polymer containing only the structure represented by the general formula (2), but may contain other monomer units as long as the properties of the chemically amplified resist are not impaired.

Other monomer structures include acrylic acid, methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, t-butyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, and t-butyl methacrylate.
Butyl methacrylate, methyl α-chloroacrylate, ethyl α-chloroacrylate, n-butyl α-chloroacrylate, methyl α-cyanoacrylate, ethyl α-cyanoacrylate, isopropyl α-cyanoacrylate, n-butyl α-cyanoacrylate, styrene , P-hydroxystyrene, α-methylstyrene, α-methyl-p-hydroxystyrene, maleic acid, maleic anhydride, crotonic acid, fumaric acid, mesaconic acid, citraconic acid, itaconic acid, acrylonitrile, methacrylonitrile, crotonitrile , Maleinitrile, fumaronitrile, metaconitrile, citraconitrile, itaconitrile, vinylaniline, vinylpyrrolidone, vinylimidazole and the like.

The weight average molecular weight of the polymer used in the present invention is 4,000 to 4,000 in terms of polystyrene measured by GPC.
1500000, preferably 5000 to 100000,
More preferably, it is 5,000 to 50,000.

The positive radiation-sensitive composition of the present invention contains an acid generator that generates an acid upon irradiation with radiation.
Specific examples of the acid generator include an onium salt, a halogen-containing compound, a diazoketone compound, a diazomethane compound, a sulfone compound, a sulfonate compound, and a sulfonimide compound.

Specific examples of onium salts include diazonium salts, ammonium salts, iodonium salts, sulfonium salts, phosphonium salts, oxonium salts and the like. Preferred onium salts include diphenyliodonium triflate, diphenyliodonium pyrene sulfonate, diphenyliodonium dodecylbenzenesulfonate, triphenylsulfonium triflate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium naphthalenesulfonate, (hydroxyphenyl) benzylmethylsulfonium toluenesulfonate And the like.

Specific examples of the halogen-containing compound include a haloalkyl group-containing hydrocarbon compound and a haloalkyl group-containing heterocyclic compound. Preferred halogen-containing compounds include 1,1-bis (4-chlorophenyl) -2,2,2-trichloroethane, 2-phenyl-4,6-bis (trichloromethyl) -s-triazine, and 2-naphthyl-4,6. -Bis (trichloromethyl)
-S-triazine and the like.

Specific examples of the diazoketone compound include a 1,3-diketo-2-diazo compound, a diazobenzoquinone compound, and a diazonaphthoquinone compound. Preferred diazoketone compounds are 1,2-naphthoquinonediazido-4-sulfonic acid and 2,2,3,4,4 '
Esters with tetrahydroxybenzophenone, 1,
2-naphthoquinonediazide-4-sulfonic acid and 1,1,
Examples thereof include esters with 1-tris (4-hydroxyphenyl) ethane.

Specific examples of the diazomethane compound include bis (trifluoromethylsulfonyl) diazomethane, bis (cyclohexylsulfonyl) diazomethane,
Bis (phenylsulfonyl) diazomethane, bis (p-
Tolylsulfonyl) diazomethane, bis (2,4-xylylsulfonyl) diazomethane, bis (p-chlorophenylsulfonyl) diazomethane, methylsulfonyl-p
-Toluenesulfonyldiazomethane, cyclohexylsulfonyl (1,1-dimethylethylsulfonyl) diazomethane, bis (1,1-dimethylethylsulfonyl) diazomethane, phenylsulfonyl (benzoyl) diazomethane and the like.

Specific examples of the sulfone compound include β
-Ketosulfone compounds, β-sulfonylsulfone compounds and the like. Preferred compounds include 4-trisphenacylsulfone, mesitylphenacylsulfone,
Bis (phenylsulfonyl) methane and the like can be mentioned.

Examples of the sulfonic acid ester compound include:
Examples thereof include alkylsulfonic acid esters, haloalkylsulfonic acid esters, arylsulfonic acid esters, and iminosulfonates. Specific examples of the sulfonic acid compound include benzoin tosylate, pyrogallol trimesylate, and nitrobenzyl-9,10-diethoxyanthracene-2-sulfonate.

Specific examples of the sulfonimide compound include N- (trifluoromethylsulfonyloxy) succinimide, N- (trifluoromethylsulfonyloxy) phthalimide, N- (trifluoromethylsulfonyloxy) diphenylmaleimide, and 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) naphthyldicarboximide, N- (campanylsulfonyloxy) succinimide, N- (campanylsulfonyloxy)
Phthalimide, N- (campanylsulfonyloxy)
Diphenylmaleimide, N- (campanylsulfonyloxy) bicyclo [2.2.1] hept-5-ene-
2,3-dicarboximide, N- (campanylsulfonyloxy) -7-oxabicyclo [2.2.1]
Hept-5-ene-2,3-dicarboximide, N
-(Campanylsulfonyloxy) bicyclo [2.
2.1] Heptane-5,6-oxy-2,3-dicarboximide, N- (campanylsulfonyloxy)
Naphthyl dicarboximide, 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) naphthyldicarboximide, 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)
Naphthyl dicarboximide, 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- (4-fluorophenylsulfonyloxy) -7-oxabicyclo [2.
2.1] Hept-5-ene-2,3-dicarboximide, N- (4-fluorophenylsulfonyloxy)
Bicyclo [2.2.1] heptane-5,6-oxy-
Examples thereof include 2,3-dicarboximide, N- (4-fluorophenylsulfonyloxy) naphthyldicarboximide and the like.

These acid generators can be used alone or in combination of two or more. The amount of the acid generator is usually 0.01 to 50% by weight, more preferably 0.1 to 15% by weight, based on the polymer. If the amount is less than 0.01% by weight, pattern formation becomes impossible. If the amount is more than 50% by weight, affinity with a developing solution is reduced, and poor development occurs.

The positive-working radiation-sensitive composition of the present invention may contain a dissolution inhibitor, a surfactant, a sensitizer, a stabilizer,
Additives such as an antifoaming agent and an acid diffusion inhibitor can also be added.

The positive radiation-sensitive composition of the present invention can be obtained by dissolving the above components in a solvent. The amount of the solvent used is not particularly limited, but is adjusted so that the solid content is 5 to 35% by weight. Preferred solvents used are ethyl acetate, butyl acetate, amyl acetate, ethyl propionate, methyl butyrate, methyl benzoate, methyl lactate, ethyl lactate, ethyl pyruvate, methyl β-isobutyrate, methyl 3-methoxypropionate, -Ethyl ethoxypropionate, esters such as γ-butyrolactone, cellosolves such as methyl cellosolve, ethyl cellosolve, butyl cellosolve, cellosolve esters such as methyl cellosolve acetate, ethyl cellosolve acetate, butyl cellosolve acetate, propylene glycol monomethyl ether acetate, propylene glycol Propylene glycol esters such as monoethyl ether acetate, 1,2-dimethoxyethane, 1,2
Ethers such as diethoxyethane, tetrahydrofuran, 1,4-dioxane and anisole, methyl ethyl ketone, methyl isobutyl ketone, 2-heptanone, 5
Ketones such as -methyl-3-heptanone, methyl-n-amylketone, cyclohexanone, isophorone, N
-Solvents selected from aprotic polar solvents such as -methylpyrrolidone, dimethylsulfoxide, and sulfolane, or a complex solvent thereof.

The positive-type radiation-sensitive composition of the present invention is applied on a substrate to be processed, dried, and usually used as a thin film having a thickness of 0.2 μm to 2 μm. A fine pattern can be obtained by subjecting this thin film to pattern exposure using radiation such as ultraviolet rays, far ultraviolet rays, excimer laser, electron beam, and X-rays, and then performing development. In particular, the effect is large in the case of pattern exposure using an electron beam or X-ray, and the effect is more remarkable in the case of using an electron beam.

The radiation-sensitive composition of the present invention can be developed using a known developer. Examples include inorganic alkalis such as hydroxides, carbonates, phosphates, silicates and borates of alkali metals, amines such as 2-diethylaminoethanol, monoethanolamine and diethanolamine, and tetramethylammonium hydroxide. And aqueous solutions containing one or more quaternary ammoniums such as choline and choline.

[0039]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

Example 1 1-methyl-1-phenylethyl methacrylate and 2-
Hydroxybutyl methacrylate was polymerized in a molar ratio of 1: 3 in 1,4-dioxane using dimethyl azobis (isobutyrate) as an initiator to obtain a copolymer. 1 g of the obtained copolymer, triphenylsulfonium triflate 10
0 mg is dissolved in 9 g of methyl cellosolve acetate,
The solution was filtered through a 0.1 μm filter to obtain a resist composition. The obtained resist composition was spin-coated on a silicon wafer and heated at 90 ° C. for 2 minutes to form a film having a thickness of 0.5 μm.
m was obtained. The resist film was irradiated with an electron beam in a pattern at an acceleration voltage of 20 kV using an electron beam exposure apparatus, heated at 100 ° C. for 3 minutes, and then developed with an aqueous solution of tetramethylammonium hydroxide. 1 μC /
At an exposure of cm ² , a rectangular pattern of 0.25 μm was obtained. No peeling was observed in the 0.2 μm pattern, and the adhesion to the silicon wafer was good.

Example 2 1,1-Diphenylethyl methacrylate and 2-hydroxy-2-methylpropyl methacrylate were polymerized at a molar ratio of 1: 3 in 1,4-dioxane using azobis (isobutyric acid) dimethyl as an initiator. To obtain a copolymer. 1 g of the obtained copolymer and 100 mg of N- (trifluoromethylsulfonyloxy) naphthyldicarboximide
-Methyl-3-heptanone was dissolved in 9 g, and filtered through a 0.1 μm filter to obtain a resist composition. Example 1
Exposure using a resist composition obtained in the same manner as, was developed with an exposure dose of 0.8 C / cm ^2, 0.25 micron
m rectangular pattern was obtained. No peeling was observed in the 0.2 μm pattern, and the adhesion to the silicon wafer was good.

Example 3 1-Methyl-1-phenylethyl-α-chloroacrylate and 2-hydroxyethyl methacrylate in a molar ratio of 1: 3 in 1,4-dioxane in azobis (isobutyric acid)
Polymerization was carried out using dimethyl as an initiator to obtain a copolymer. A resist composition was obtained from 1 g of the obtained copolymer in the same manner as in Example 1. Exposure and development were performed using the resist composition obtained in the same manner as in Example 1. As a result, a 0.25 μm rectangular pattern was obtained at an exposure dose of 1 μC / cm ² . Also,
No peeling was observed in the 0.2 μm pattern, and the adhesion to the silicon wafer was good.

Example 4 The 2-hydroxyethyl methacrylate of Example 3 was replaced with 2-
A resist composition was obtained in the same manner as in Example 3 except that the composition was changed to hydroxy-3-phenoxypropyl acrylate. Exposure and development were performed using the resist composition obtained in the same manner as in Example 1, and at an exposure of 1 μC / cm ² ,
A rectangular pattern of 0.2 μm was obtained. Also, 0.2μ
No peeling was observed in the pattern of m, and the adhesion to the silicon wafer was good.

Example 5 1-Methyl-1-phenylethyl-α-bromoacrylate and 1-hydroxy-1-methylethyl methacrylate in a molar ratio of 1: 3 in 1,4-dioxane in azobis (isobutyric acid) dimethyl ester Was used as an initiator to obtain a copolymer. A resist composition was obtained from 1 g of the obtained copolymer in the same manner as in Example 1. Exposure and development were performed using the resist composition obtained in the same manner as in Example 1, and 1 μC /
At an exposure of cm ² , a 0.2 μm rectangular pattern was obtained. Also, no peeling was observed in the 0.2 μm pattern,
The adhesion to the silicon wafer was good.

Example 6 1-Methyl-1-phenylethyl-α-cyanoacrylate and 2-hydroxyethyl methacrylate in a molar ratio of 1: 3 in 1,4-dioxane in azobis (isobutyric acid)
Polymerization was carried out using dimethyl as an initiator to obtain a copolymer. A resist composition was obtained from 1 g of the obtained copolymer in the same manner as in Example 1. Exposure and development were performed using the resist composition obtained in the same manner as in Example 1. As a result, a 0.25 μm rectangular pattern was obtained at an exposure dose of 1 μC / cm ² . Also,
No peeling was observed in the 0.2 μm pattern, and the adhesion to the silicon wafer was good.

Example 7 1-Methyl-1-phenylethyl-α-cyanoacrylate and 2-hydroxypropyl methacrylate were mixed at a ratio of 1: 3
Was polymerized in 1,4-dioxane using dimethyl azobis (isobutyrate) as an initiator to obtain a copolymer.
1 g of the obtained copolymer, 100 m of N- (trifluoromethylsulfonyloxy) naphthyldicarboximide
g was dissolved in 9 g of cyclohexanone, and filtered through a 0.1 μm filter to obtain a resist composition. Exposure and development were performed using the resist composition obtained in the same manner as in Example 1. As a result, a 0.2 μm rectangular pattern was obtained at an exposure dose of 1 μC / cm ² . No peeling was observed in the 0.2 μm pattern, and the adhesion to the silicon wafer was good.

Example 8 1,1-Diphenylethyl-α-cyanoacrylate and p- (1-hydroxy-1-methylethyl) phenyl methacrylate were mixed with 1,3-dioxane in 1,4-dioxane at a molar ratio of 1: 3. Polymerization was performed using dimethyl (butyrate) as an initiator to obtain a copolymer. A resist composition was obtained from 1 g of the obtained copolymer in the same manner as in Example 7. Exposure and development were performed using the resist composition obtained in the same manner as in Example 1. As a result, a 0.2 μm rectangular pattern was obtained with an exposure amount of 0.7 μC / cm ² . No peeling was observed in the 0.2 μm pattern, and the adhesion to the silicon wafer was good.

Example 9 The resist composition obtained in Example 1 was spin-coated on a silicon wafer and heated at 90 ° C. for 2 minutes to obtain a resist film having a thickness of 0.3 μm. Kr is applied to this resist film.
Exposure is performed using an F excimer laser stepper.
After heating at 00 ° C. for 3 minutes, development was performed with an aqueous solution of tetramethylammonium hydroxide. At an exposure of 25 mJ / cm ² , a rectangular pattern of 0.25 μm was obtained. No peeling was observed in the 0.2 μm pattern, and the adhesion to the silicon wafer was good.

Comparative Example 1 Only 1-methyl-1-phenylethyl methacrylate was polymerized in 1,4-dioxane using dimethyl azobis (isobutyrate) as an initiator to obtain a polymer. 1 g of the obtained polymer, 100 m of triphenylsulfonium triflate
g was dissolved in 9 g of methyl cellosolve acetate, and 0.1 g
The mixture was filtered through a μm filter to obtain a resist composition. Exposure using the resist composition obtained in the same manner as in Example 1,
It was developing, with an exposure amount of 1.5μC / cm ^2, 0.
Only a 5 μm rectangular pattern was obtained. Further, the pattern of 0.5 μm or less was peeled off, and the adhesion to the silicon wafer was poor.

Comparative Example 2 1-methyl-1-phenylethyl methacrylate and 2-methyl-1-phenylethyl methacrylate
A resist composition was obtained in the same manner as in Comparative Example 1 using hydroxyethyl methacrylate. Exposure and development were performed using the resist composition obtained in the same manner as in Example 1.
At an exposure of 1.2 μC / cm ² , only a 0.45 μm rectangular pattern was obtained. On the other hand, no peeling was observed in the 0.2 μm pattern, and the adhesion to the silicon wafer was good.

Comparative Example 3 When the resist composition obtained in Comparative Example 1 was exposed and developed in the same manner as in Example 9, the resist composition was exposed at an exposure amount of 40 mJ / cm ² .
Only a 0.5 μm rectangular pattern was obtained.
Further, the pattern of 0.5 μm or less was peeled off, and the adhesion to the silicon wafer was poor.

[0052]

As described above, the positive-type radiation-sensitive composition of the present invention comprises an α-substituted acrylate structural unit having a specific structure and an acrylate-based monomer structural unit having an alcoholic hydroxy group in a side chain. A polymer containing
And by using a positive-type radiation-sensitive composition containing an acid generator that generates an acid upon irradiation with radiation,
It has become possible to obtain a composition with high resolution and high sensitivity. Further, the adhesion to the silicon wafer was improved.

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[Procedure amendment]

[Submission date] July 18, 2001 (2001.7.1)
8)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0033

[Correction method] Change

[Correction contents]

Specific examples of the sulfonimide compound include N- (trifluoromethylsulfonyloxy) succinimide, N- (trifluoromethylsulfonyloxy) phthalimide, N- (trifluoromethylsulfonyloxy) diphenylmaleimide, and 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-dicarboxylic imide, N- (trifluoromethylsulfonyloxy) naphthyl dicarboxyl imide, N- (Kanfu § over sulfonyloxy) succinimide, N- (Kanfu § over sulfonyloxy) phthalimide, N- ( Kanfu § over sulfonyloxy) diphenyl maleimide, N- (Kanfu § over sulfonyloxy)
Bicyclo [2.2.1] hept-5-ene-2,3-dicarboxylic imide, N- (Kanfu § over sulfonyloxy) -7-oxabicyclo [2.2.1] hept-5
Ene-2,3-dicarboxylic imide, N- (Kanfu §
Over sulfonyloxy) bicyclo [2.2.1] heptane-5,6-oxy-2,3-dicarboxylic imide, N
- (Kanfu § over sulfonyloxy) naphthyl dicarboxyl imides, N-(4-methylphenyl sulfonyloxy) succinimide, N-(4-methylphenyl sulfonyloxy) phthalimide, N-(4-methylphenyl-sulfonyloxy) diphenyl maleimide, 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) naphthyldicarboximide, 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) naphthyldicarboxyl Imide, 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- (4-fluorophenylsulfonyloxy) -7-oxabicyclo [2.2. 1] Hept-5
-Ene-2,3-dicarboximide, N- (4-fluorophenylsulfonyloxy) bicyclo [2.2.
1] Heptane-5,6-oxy-2,3-dicarboximide, N- (4-fluorophenylsulfonyloxy) naphthyldicarboximide and the like.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 33/22 C08L 33/22 H01L 21/027 H01L 21/30 502R F-term (Reference) 2H025 AA01 AA02 AB16 AB20 AC05 AC06 AD03 BE00 BE10 BF08 BG00 CB14 CB41 CB45 4J002 BG071 EB006 EN136 EQ016 EV296 GP03 4J100 AL08P AL08Q AL09P AL09Q AM05P BA02Q BB01P BC43P BC43Q CA04 JA38

Claims (3)

[Claims] 1. A positive-working impression comprising a polymer containing structural units represented by the following general formulas (1) and (2) and an acid generator that generates an acid upon irradiation with radiation. Radioactive composition. Embedded image (Here, X represents an alkyl group having 1 to 6 carbon atoms, a halogen element, or a cyano group, and A represents an organic group which is bonded to oxygen by tertiary carbon and contains an aromatic ring.) Formula 2 (Where Y is an alkyl group having 1 to 6 carbon atoms, a hydrogen atom,
Represents either a halogen element or a cyano group, and when X in the general formula (1) is an alkyl group having 1 to 6 carbon atoms,
B represents an organic group having 2 to 16 carbon atoms containing a secondary or tertiary alcoholic hydroxy group, and X in the general formula (1)
Is a halogen element or a cyano group,
B represents an organic group having 1 to 16 carbon atoms containing a primary, secondary or tertiary alcoholic hydroxy group. ) 2. The positive radiation-sensitive composition according to claim 1, wherein A in the general formula (1) is represented by the following general formula (3). Embedded image (Here, R ₁ , R ₂ , and R ₃ may be the same or different from each other, and may be an optionally substituted alkyl group having 1 to 6 carbon atoms, or an optionally substituted aryl group having 6 to 15 carbon atoms. Represents an optionally substituted aralkyl group having 7 to 16 carbon atoms, provided that none of R ₁ , R ₂ , and R ₃ simultaneously become an alkyl group.) 3. The positive radiation-sensitive composition according to claim 1, wherein the radiation for irradiation is an electron beam or an X-ray.