JP2003222999A - Resist composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a chemically amplified positive resist composition suitable for excimer laser lithography, having good resist performances such as sensitivity and resolution and excellent in dry etching resistance. <P>SOLUTION: The chemically amplified positive resist composition contains an acid generator and a resin which contains at least one polymerized unit selected from the group comprising polymerized units represented by formula (Ia) and polymerized units represented by formula (Ib) and a polymerized unit having an epoxy group selected from formula (II), is insoluble or slightly soluble in an aqueous alkali solution and is made soluble in the aqueous alkali solution by the action of an acid. In the formulae (Ia) and (Ib), R<SB>1</SB>-R<SB>4</SB>are independently H or methyl and n is an integer of 1-3. In the formula (II), R<SB>6</SB>and R<SB>7</SB>are independently H or alkyl and m is an integer of 1-8. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a chemically amplified positive resist composition used for fine processing of semiconductors.

[0002]

2. Description of the Related Art A lithography process using a resist composition is usually employed for fine processing of semiconductors. In lithography, Rayleigh is used.
As represented by the diffraction limit formula of gh), in principle, the shorter the exposure wavelength, the higher the resolution can be. The exposure light source for lithography used for manufacturing semiconductors is a g-line with a wavelength of 436 nm, an i-line with a wavelength of 365 nm, and a wavelength of 24
The wavelength of the KrF excimer laser of 8 nm is becoming shorter and shorter year by year, and the lithography technology using the ArF excimer laser of wavelength 193 nm, which has been further shortened, is about to be introduced. Further, as a next-generation light source, F ₂ excimer laser lithography technology with a wavelength of 157 nm is being studied, and electron beam lithography technology using an electron beam is also being actively studied.

Since the lens used in such a short wavelength exposure machine has a shorter life than that of a conventional exposure light source, it is desirable that the exposure time to the short wavelength excimer laser beam is as short as possible. For that purpose, since it is necessary to increase the sensitivity of the resist, a so-called “chemically amplified resist” containing a resin having a group that is cleaved by the acid is used by utilizing the catalytic action of an acid generated by exposure. ing.

In shortening the wavelength of such a light source, the resin used for the resist also varies depending on the light source used.
In rF excimer laser lithography, polyvinylphenol resin is mainly used, and in ArF excimer laser lithography, acrylic resin or cycloolefin resin is mainly used.

[0005]

However, even when these resins are used, the performance is still insufficient, and the present inventors have found that a resist composition having excellent dry etching resistance is required. I found it. An object of the present invention is a chemically amplified positive resist composition suitable for excimer laser lithography such as ArF and KrF, which has various resist performances such as sensitivity and resolution and excellent dry etching resistance. Another object is to provide a positive chemically amplified resist composition.

The inventors of the present invention have made extensive studies as to a chemically amplified positive resist composition so as to solve the above problems. As a result, a resin soluble in an alkaline aqueous solution by the action of an acid is used. The chemically amplified positive resist composition containing a polymer unit having an epoxy group such as formula (II) therein not only provides dry etching resistance,
The inventors have found that various resist performances are also good, and completed the present invention.

[0007]

That is, the present invention provides at least one polymerized unit selected from the group consisting of polymerized units represented by the following formula (Ia) and (Ib). A resin containing a polymerized unit having an epoxy group selected from the formula (II), which itself is insoluble or hardly soluble in an alkaline aqueous solution, but becomes soluble in the alkaline aqueous solution by the action of an acid, and an acid generator. The present invention relates to a chemically amplified positive resist composition containing the same. (Ia) (Ib) (In the formula, R ₁ , R ₂ , R ₃ , and R ₄ each independently represent a hydrogen atom or a methyl group, and n represents an integer of 1 to _3. R ₂
When there are a plurality of R's, they may be the same or different, and R
_{When 4} is plural, they may be the same or different from each other. ) (II) (In the formula, R _{6 and} R ₇ each independently represent a hydrogen atom or an alkyl group _. M represents an integer of 1 to 8.)

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The composition of the present invention will be specifically described below. The resin constituting the resist composition of the present invention is at least 1 selected from the group consisting of the polymerized unit represented by (Ia) and the polymerized unit represented by (Ib).
It is a resin containing polymerized units of alicyclic lactone of a kind, which is insoluble or hardly soluble in an alkaline aqueous solution itself, but becomes soluble in the alkaline aqueous solution by the action of an acid. The polymer unit represented by (Ia) and the polymer unit represented by (Ib) have an acid labile group, specifically, a group capable of being cleaved by the action of an acid. The polymer units of the alicyclic lactone represented by the formulas (Ia) and (Ib) are 10 to 10 in the total resin.
The range of 90 mol% is preferred.

In addition to the above, the resin according to the present invention may contain a polymerized unit having an acid labile group. Specific examples of such an acid-labile group include various esters of carboxylic acids, for example, alkyl esters represented by methyl ester and tert-butyl ester; methoxymethyl ester, ethoxymethyl ester, 1-ethoxyethyl. Ester, 1-isobutoxyethyl ester, 1
-Isopropoxy ethyl ester, 1-ethoxypropyl ester, 1- (2-methoxyethoxy) ethyl ester, 1- (2-acetoxyethoxy) ethyl ester, 1- [2- (1-adamantyloxy) ethoxy]
Acetal-type esters such as ethyl ester, 1- [2- (1-adamantanecarbonylcarbonyl) ethoxy] ethyl ester, tetrahydro-2-furyl ester and tetrahydro-2-pyranyl ester; isobornyl ester, 2-alkyl- Examples thereof include alicyclic esters such as 2-adamantyl ester and 1- (1-adamantyl) -1-alkylalkyl ester. The monomer leading to the polymerized unit having such a carboxylic acid ester may be a (meth) acrylic type monomer such as a methacrylic acid ester or an acrylic acid ester, or a norbornene carboxylic acid ester, a tricyclodecene carboxylic acid ester, or a tetracyclo carboxylic acid ester. The carboxylic acid ester group may be bonded to an alicyclic monomer, such as decenecarboxylic acid ester.

Among such monomers, a bulk containing an alicyclic group such as 2-alkyl-2-adamantyl and 1- (1-adamantyl) -1-alkylalkyl as a group that is cleaved by the action of an acid. It is preferable to use the one having a high group because the resolution is excellent. Examples of the monomer containing such a bulky group include 2-alkyl-2-adamantyl (meth) acrylate and 1- (meth) acrylic acid.
(1-adamantyl) -1-alkylalkyl, 5-norbornene-2-carboxylic acid 2-alkyl-2-adamantyl, 5-norbornene-2-carboxylic acid 1- (1-
Adamantyl) -1-alkylalkyl and the like. In particular, it is preferable to use 2-alkyl-2-adamantyl (meth) acrylate as a monomer because the resolution is excellent. Such (meth) acrylic acid 2-
As a typical example of alkyl-2-adamantyl, for example, 2-methyl-2-adamantyl acrylate, 2-methyl-2-adamantyl methacrylate, 2-ethyl-2-adamantyl acrylate, 2-ethyl-2-methacrylate.
Examples include adamantyl and 2-n-butyl-2-adamantyl acrylate. Of these, 2-ethyl-2-adamantyl (meth) acrylate is particularly preferable because it has a good balance of sensitivity and heat resistance. If necessary, other monomers having a group capable of being cleaved by the action of an acid may be used in combination.

The 2-alkyl-2-adamantyl (meth) acrylate can be usually produced by reacting 2-alkyl-2-adamantanol or a metal salt thereof with an acrylic acid halide or a methacrylic acid halide.

The monomer for leading to the polymerized units of the alicyclic lactone represented by the formulas (Ia) and (Ib) is specifically, for example, the following alicyclic lactone having a hydroxyl group.
(Meth) acrylic acid ester, a mixture thereof and the like can be mentioned. These esters can be produced, for example, by reacting a corresponding alicyclic lactone having a hydroxyl group with (meth) acrylic acid (for example, JP 2000-26446 A).

[0013]

In addition to the above alicyclic lactone polymer units, polymer units of 3-hydroxy-1-adamantyl (meth) acrylate, polymer units of 3,5-dihydroxy-1-adamantyl (meth) acrylate, and lactones. Ring-substituted (meth) acryloyloxy-γ
-The polymer units of butyrolactone are all highly polar,
The presence of at least one of them in the resin improves the adhesion of the resist containing the same to the substrate.
These polymerized units also contribute to improving the resolution of the resist.

(Meth) acrylic acid 3-hydroxy-1-
Although adamantyl and 3,5-dihydroxy-1-adamantyl (meth) acrylic acid are commercially available, they can also be produced, for example, by reacting the corresponding hydroxyadamantane with (meth) acrylic acid or a halide thereof. In addition, (meth) acryloyloxy-γ-butyrolactone is obtained by reacting α- or β-bromo-γ-butyrolactone whose lactone ring may be substituted with alkyl with acrylic acid or methacrylic acid, or when the lactone ring is alkyl. It can be produced by reacting an optionally substituted α- or β-hydroxy-γ-butyrolactone with an acrylic acid halide or a methacrylic acid halide.

Here, (meth) acryloyloxy-γ-
Examples of the monomer for introducing the polymerized units of butyrolactone include α-acryloyloxy-γ-butyrolactone, α-methacryloyloxy-γ-butyrolactone, α
-Acryloyloxy-β, β-dimethyl-γ-butyrolactone, α-methacryloyloxy-β, β-dimethyl-
γ-butyrolactone, α-acryloyloxy-α-methyl-γ-butyrolactone, α-methacryloyloxy-α
-Methyl-γ-butyrolactone, β-acryloyloxy-γ-butyrolactone, β-methacryloyloxy-γ-
Examples include butyrolactone and β-methacryloyloxy-α-methyl-γ-butyrolactone.

Further, 2-alkyl- (meth) acrylate-
As a polymer unit other than the polymer units of 2-adamantyl and 1- (1-adamantyl) -1-alkylalkyl (meth) acrylate, 3-hydroxy-1 (meth) acrylate is used.
-Polymerized units of adamantyl, (meth) acrylic acid 3,5
-Dihydroxy-1-adamantyl, polymerized units of α- (meth) acryloyloxy-γ-butyrolactone, β-
When polymerized units of (meth) acryloyloxy-γ-butyrolactone, hydroxystyrene, etc. are present, it is preferable that their total be in the range of 10 to 75 mol% of the entire resin.

Next, the polymerized unit having an epoxy group in the present invention will be described. The polymerized units can be used alone or in combination of two or more kinds. These polymerized units are insoluble in the alkaline aqueous solution themselves, but are preferably contained in the resin which becomes soluble in the alkaline aqueous solution by the action of an acid in an amount of 0.5 to 10 mol%, particularly 1 to 5 Mol% is preferred. When the content of the polymerized unit is high, the dry etching resistance is improved, but the sensitivity,
The resolution is reduced.

Examples of the polymer unit having an epoxy group include those represented by the following formula (III). (III) (In the formula, R ₈ represents a hydrogen atom or a methyl group, and R _9, R
Each ₁₀ independently represents a hydrogen atom or an alkyl group.
m represents an integer of 1 to 8. )

Specific examples of the monomer leading to the polymerized unit having the structure of formula (III) include glycidyl (meth).
Examples thereof include acrylate, methylglycidyl (meth) acrylate, propylglycidyl (meth) acrylate, isopropylglycidyl (meth) acrylate, butylglycidyl (meth) acrylate, isobutylglycidyl (meth) acrylate, and t-butylglycidyl (meth) acrylate. Among these, methyl glycidyl (meth) acrylate, which is a monomer of the polymerized unit of the above formula (IV), is particularly preferable because it has the smallest decrease in sensitivity and resolution.

The acid generator in the present invention can be various compounds that generate an acid by irradiating the substance itself or the resist composition containing the substance with radiation. Examples thereof include onium salts, halogenated alkyltriazine compounds, disulfone compounds, compounds having a diazomethanesulfonyl skeleton, and sulfonate compounds. Specific examples of such an acid generator are as follows.

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, 4-methoxyphenyldiphenylsulfonium hexafluoroantimonate, 4-methoxyphenyldiphenylsulfonium trifluoromethanesulfonate, p-tolyldiphenyl Sulfonium trifluoromethanesulfonate, p-
Tolyldiphenylsulfonium perfluorobutanesulfonate, p-tolyldiphenylsulfonium perfluorooctanesulfonate, 2,4,6-trimethylphenyldiphenylsulfonium trifluoromethanesulfonate, 4-tert-butylphenyldiphenylsulfonium trifluoromethanesulfonate, 4-
Phenylthiophenyldiphenylsulfonium hexafluorophosphate, 4-phenylthiophenyldiphenylsulfonium hexafluoroantimonate,
1- (2-naphthoylmethyl) thioranium hexafluoroantimonate, 1- (2-naphthoylmethyl)
Thioranium trifluoromethanesulfonate, 4-
Hydroxy-1-naphthyldimethylsulfonium hexafluoroantimonate, 4-hydroxy-1-naphthyldimethylsulfonium trifluoromethanesulfonate, cyclohexylmethyl (2-oxocyclohexyl) sulfonium trifluoromethanesulfonate, cyclohexylmethyl (2-oxocyclohexyl) sulfonium perfluorobutane Sulfonate,
Cyclohexylmethyl (2-oxocyclohexyl) sulfonium perfluorooctane sulfonate, 2-
Oxo-3-phenylethyl thiacyclopentanium trifluoromethanesulfonate, 2-oxo-3-
Phenylethyl thiacyclopentanium perfluorobutane sulfonate, 2-oxo-3-phenylethyl thiacyclopentanium perfluorooctane 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,

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

1-benzoyl-1-phenylmethyl p
-Toluene sulfonate (common name benzoin tosylate), 2-benzoyl-2-hydroxy-2-phenylethyl p-toluene sulfonate (common name α-methylol benzoin tosylate), 1,2,3-benzenetriyl trismethane sulfonate, 2 , 6-dinitrobenzyl p-toluenesulfonate, 2-nitrobenzyl p-toluenesulfonate, 4-nitrobenzyl
p-toluenesulfonate,

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

Further, in the chemically amplified positive resist composition of the present invention, a basic compound, particularly a basic nitrogen-containing organic compound such as amines is added as a quencher so that it can be retained after exposure. Performance deterioration due to acid deactivation can be improved. Specific examples of the basic compound used for the quencher include those represented by the following formulas.

[0029]

[0030]

In the formula, R ²⁰ , R ²¹ and R ²⁶ each independently represent hydrogen, alkyl, cycloalkyl, aryl or alkoxy. The alkyl, cycloalkyl, aryl or alkoxy may be each independently substituted with a hydroxyl group, an amino group or an alkoxy group having 1 to 6 carbon atoms. The amino group may be substituted with an alkyl group having 1 to 4 carbon atoms. The alkyl preferably has about 1 to 6 carbon atoms, the cycloalkyl preferably has about 5 to 10 carbon atoms, and the aryl has 6 to 1 carbon atoms.
About 0 is preferable, and the alkoxy preferably has about 1 to 6 carbon atoms. R ²² , R ²³ and R ²⁴ are each independently
Represents hydrogen, alkyl, cycloalkyl, aryl or alkoxy. The alkyl, cycloalkyl, aryl,
Alternatively, the alkoxy may be independently substituted with a hydroxyl group, an amino group, or an alkoxy group having 1 to 6 carbon atoms. The amino group may be substituted with an alkyl group having 1 to 4 carbon atoms. The alkyl has 1 carbon atom.
Is preferably about 6 and the cycloalkyl has 5 to 5 carbon atoms.
The aryl preferably has about 6 to 10 carbon atoms, and the alkoxy preferably has about 1 to 6 carbon atoms. R ²⁵ represents alkyl or cycloalkyl.
The alkyl or cycloalkyl may be independently substituted with a hydroxyl group, an amino group or an alkoxy group having 1 to 6 carbon atoms. The amino group may be substituted with an alkyl group having 1 to 4 carbon atoms. Further, the alkyl is
It preferably has about 1 to 6 carbon atoms, and the cycloalkyl preferably has about 5 to 10 carbon atoms. A represents alkylene, carbonyl, imino, sulfide or disulfide.
The alkylene preferably has about 2 to 6 carbon atoms. Further, R ^{20 to} R ²⁶ may have either a linear structure or a branched structure, and any of them may be used.

In the resist composition of the present invention, although it is insoluble in an alkaline aqueous solution itself, 0.1 to 20 parts by weight of an acid generator is added to 100 parts by weight of a resin which is soluble in an alkaline aqueous solution by the action of an acid. It is preferably contained in the range of parts by weight. When a basic compound is used as a quencher, it is also in the range of 0.001 to 1 part by weight, more preferably 0.01 to 1 part by weight per 100 parts by weight of the resin of the resist composition.
It is preferably contained in a ratio of parts by weight. The composition of the present invention may also contain a small amount of various additives such as a sensitizer, a dissolution inhibitor, another resin, a surfactant, a stabilizer and a dye, if necessary.

The resist composition of the present invention usually becomes a liquid resist composition in a state in which each of the above components is dissolved in a solvent, and is applied onto a substrate such as a silicon wafer by a conventional method such as spin coating. . The solvent used here may be any solvent that dissolves each component, has an appropriate drying rate, and gives a uniform and smooth coating film after the solvent evaporates. Solvents generally used in this field are used. You can. 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. And ketones such as cyclohexanone; cyclic esters such as γ-butyrolactone. These solvents may be used alone or in combination of two or more.

The resist film coated and dried on the substrate is subjected to an exposure treatment for patterning, then a heat treatment for promoting a deprotecting group reaction, and then developed with an alkali developing solution. It The alkaline developer used here can be various alkaline aqueous solutions used in this field, but in general, an aqueous solution of tetramethylammonium hydroxide or (2-hydroxyethyl) trimethylammonium hydroxide (commonly called choline) is used. Often used.

[0035]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. In the example, the "part" that represents the amount used is
Unless otherwise specified, it is based on weight.

The physical properties of the resist resin and the evaluation of the resist composition were evaluated by the following methods. <Weight average molecular weight> Polystyrene was determined by gel permeation chromatography (GPC) as a standard product.

<Effective Sensitivity> After exposing a resist film formed on a silicon wafer coated with an organic antireflection film,
Immediately after exposure, baking was performed, and then development was performed with an alkali developing solution to form a resist pattern. The exposure amount at which the 0.18 μm line and space gives a line width of 1: 1 was measured as the effective sensitivity.

<Resolution> The minimum dimension of the line-and-space pattern separated by the exposure amount of the above-mentioned effective sensitivity is defined as the resolution.

<Measurement of dry etching resistance> A 0.5 μm resist film was formed on a silicon wafer, and DEM was used.
-451 (manufactured by Anelva Co., Ltd.), mixed gas
Oxygen 2.5 sccm, CHF ₃ 50 sccm, vacuum degree 1
Etching was performed for 4 minutes with INCIDENSE POWER 250W at 6 Pa, and the difference in film thickness before and after etching was expressed as a ratio to that of the novolac resin as an etching rate. The smaller the value, the higher the dry etching resistance. Further, the resist surface after etching was observed with a scanning electron microscope, and those that were improved and smoother than those of the comparative example were evaluated as ◯, and those that were rough and not improved were evaluated as x.

Resin Synthesis Example 1 (Synthesis of Resin A1) A 200 ml flask was charged with 16.00 g of 2-ethyl-2-adamantyl methacrylate, 19.12 g of norbornane lactone acrylate and 0.75 g of methyl glycidyl methacrylate (molar ratio 40:57). : 3), and 90.0 g of 1,4-dioxane as a solvent were further added to obtain a solution. After the temperature of the solution was raised to 85 ° C., 2,2′-azobisisobutyronitrile was added as a polymerization initiator to 0.2%.
79 g was added and reacted. After incubating at 85 ℃ for 5 hours,
The procedure of cooling and dropping the reaction solution into a large amount of methanol for purification was repeated 3 times to obtain a copolymer having the following structure with a molecular weight of 7,500 and a dispersity of 1.67. This is resin A
Set to 1.

[0041]

Resin Synthesis Example 2 (Synthesis of Resin A2) A 200 ml flask was charged with 16.00 g of 2-ethyl-2-adamantyl methacrylate, 19.12 g of norbornane lactone acrylate and 0.68 g of glycidyl methacrylate (molar ratio 40:57: 3) and 90.0 g of 1,4-dioxane as a solvent were further added to obtain a solution. After raising the temperature of the solution to 85 ° C., 0.72 of 2,2′-azobisisobutyronitrile was used as a polymerization initiator.
g was added and reacted. After keeping the temperature at 85 ° C. for 5 hours, cooling, dropping the reaction solution into a large amount of methanol and purifying the mixture was repeated 3 times to obtain a copolymer having the following structure with a molecular weight of 8200 and a dispersity of 1.68. It was This is resin A2
And

[0043]

Comparative Resin Synthesis Example 1 (Synthesis of Resin A3) A 200 ml flask was charged with 16.00 g of 2-ethyl-2-adamantyl methacrylate and 20.12 g of norbornane lactone acrylate (molar ratio 40: 6).
0), and 105.0 g of 1,4-dioxane as a solvent.
Was added to form a solution. After heating the solution to 85 ° C., 0.79 g of 2,2′-azobisisobutyronitrile as a polymerization initiator was added and reacted. After incubating at 85 ° C for 5 hours, cooling, dropping the reaction solution into a large amount of methanol and refining it three times, the molecular weight was 7
A copolymer having the following structure with 500 and a dispersity of 1.68 was obtained.
This is designated as resin A3.

[0045]

Next, in addition to the resins (A1), (A2) and (A3) obtained in the above resin synthesis examples, resist compositions were prepared using the following raw materials and evaluated. <Acid generator> B1: p-tolyldiphenylsulfonium perfluorooctanesulfonate <quencher> C1: 2,6-diisopropylaniline <solvent> D1: Propylene glycol monomethyl ether acetate 57 parts γ-butyrolactone 3 parts

Examples 1 and 2 and Comparative Example 1 Each component shown above was made into a uniform solution, and then the pore size was 0.2.
A resist composition solution was prepared by filtering through a μm fluororesin filter. NISSAN CHEMICAL INDUSTRIES
"ARC-29" which is a composition for organic antireflection film manufactured by Co., Ltd.
A) is applied and baked at 215 ° C. for 60 seconds to form an organic antireflection film having a thickness of 780 Å, and then the above-mentioned resist solution is dried to a film thickness of 0.385 μm. After coating the resist solution, spin coat 1
Prebaked at 30 ° C. for 60 seconds. ArF excimer stepper [“NSR ArF” manufactured by Nikon Corporation, NA =
0.55, σ = 0.6], and the line and space pattern was exposed by changing the exposure amount stepwise. After exposure, post-exposure bake was performed on a hot plate at 110 ° C. for 60 seconds, and paddle development was further performed for 60 seconds with a 2.38 wt% tetramethylammonium hydroxide aqueous solution.

The bright field pattern after development on the organic antireflection film substrate was observed with a scanning electron microscope, and the results are shown in Table 2. The bright field pattern referred to here is that the outer frame is a chrome layer (light-shielding layer).
Then, it is obtained by exposure and development through a reticle in which a chrome layer (light-shielding layer) is linearly formed on the inside of the frame with the glass surface (light-transmitting portion) as a base. The resist layer around the pattern is removed, and the resist layer corresponding to the outer frame remains outside the pattern.

[0049]

[Table 1] ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Example No. Resin Acid generator Quencher Solvent ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Example 1 A1 / 10 part B1 / 0.2 part C1 / 0.015 part E1 Example 2 A2 / 10 part B1 / 0.2 part C1 / 0.015 part E1 ────────────────────────────── Comparative Example 1 A3 / 10 part B1 / 0.2 part C1 / 0.015 part E1 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

[0050]

[Table 2] ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Example No. Effective sensitivity Resolution Etching speed After etching ( mJ / cm ² ) (μm) (to i-line resist ratio) Surface roughness ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ━ Example 1 39 0.16 1.10 ○ Example 2 50 0.16 1.16 ○ ──────────────────────────── ─────── Comparative Example 1 18 0.16 1.37 × ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Thus, in the examples, the dry etching resistance was improved without significantly lowering the resolution.

Although the embodiments of the present invention have been described above, the embodiments of the present invention disclosed above are merely examples, and the scope of the present invention is limited to these embodiments. Not done. The scope of the present invention is defined by the claims, and includes the meaning equivalent to the description of the claims and all modifications within the scope.

[0052]

The chemically amplified positive resist composition of the present invention has improved dry etching resistance and various resist performances such as sensitivity and resolution. Therefore,
This composition can be suitably used for lithography using a KrF excimer laser, an ArF excimer laser, or the like.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yasunori Uetani             3-1,98-1 Kasugade, Konohana-ku, Osaka             Tomo Chemical Co., Ltd. F term (reference) 2H025 AA09 AB16 AC04 AC08 AD03                       BE00 BE10 BG00 CB14 CB41                       CC20 FA17                 4J100 AL08P AL08Q AL08S AL10Q                       BA03S BA11P BA11S BC09R                       BC09S BC53P BC53S BC54Q                       CA04 CA05 CA06 DA01 DA04                       DA28 DA38 JA38

Claims (10)

[Claims] 1. A polymerized unit represented by the following formula (Ia) and (I
containing at least one type of polymerized unit selected from the group consisting of polymerized units represented by b) and a polymerized unit having an epoxy group selected from the following formula (II), which itself is insoluble or sparingly soluble in an alkaline aqueous solution. However, a chemically amplified positive resist composition comprising a resin that is soluble in an aqueous alkaline solution under the action of an acid and an acid generator. (Ia) (Ib) (In the formula, R ₁ , R ₂ , R ₃ , and R ₄ each independently represent a hydrogen atom or a methyl group, and n represents an integer of 1 to _3. R ₂
When there are a plurality of R's, they may be the same or different, and R
_{When 4} is plural, they may be the same or different from each other. ) (II) (In the formula, R _{6 and} R ₇ each independently represent a hydrogen atom or an alkyl group _. M represents an integer of 1 to 8.) 2. A polymerized unit having an epoxy group selected from formula (II) is at least one selected from polymerized units represented by the following formula (III).
The chemically amplified positive resist composition as described above. ··· (III) (In the formula, R ₈ represents a hydrogen atom or a methyl group, and R _9, R
Each ₁₀ independently represents a hydrogen atom or an alkyl group.
m is the same as defined above. ) 3. The chemically amplified positive resist composition according to claim 1, wherein the polymerized unit having an epoxy group selected from the formula (II) is a polymerized unit represented by the following formula (IV). . (IV) (In the formula, R ₁₁ represents a hydrogen atom or a methyl group.) 4. A resin which is insoluble in an alkaline aqueous solution by itself but is soluble in the alkaline aqueous solution under the action of an acid, contains 0.5 to 10 mol of a polymer unit having an epoxy group selected from the formula (II). % Is included, Claims 1-3 characterized by the above-mentioned.
The chemically amplified positive resist composition as described in any one of 1. 5. The composition according to claim 1, wherein the resin has a polymerized unit having an acid labile group. 6. The composition according to claim 5, wherein the content of the polymerized units having an acid labile group in the resin is 10 to 80 mol%. 7. The composition according to claim 1, wherein the resin further contains polymerized units derived from 2-alkyl-2-adamantyl (meth) acrylate. 8. The composition according to claim 7, wherein the polymerized units derived from 2-alkyl-2-adamantyl (meth) acrylate are polymerized units derived from 2-ethyl-2-adamantyl (meth) acrylate. . 9. The polymer further comprises polymerized units derived from 3-hydroxy-1-adamantyl (meth) acrylate,
Polymerized units derived from 3,5-dihydroxy-1-adamantyl (meth) acrylic acid and the lactone ring may be substituted with alkyl (meth) acryloyloxy-γ.
-Containing at least one polymerized unit selected from the group consisting of polymerized units derived from butyrolactone.
9. The composition according to any one of to 8. 10. The composition according to claim 1, further comprising a basic compound as a quencher.