JP2002311575A - Radiation sensitive resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radiation sensitive resin composition retaining good sensitivity, excellent in resolution and margin for exposure and suitable for use in a positive type resist giving a good pattern shape and having good balance of characteristics. SOLUTION: The radiation sensitive resin composition has (A) an alkali- soluble resin, (B) a quinonediazidosulfonic ester compound and (C) an ester compound of an aliphatic dibasic acid represented by formula (1) (where R1 and R2 are each a 1-6C alkyl and R3 is methylene or a 2-6C alkylene).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation-sensitive resin composition.
Radiation-sensitive resin composition suitable as a resist for fabricating highly integrated circuits that is sensitive to various types of radiation such as X-rays such as rF excimer lasers, X-rays such as synchrotron radiation, and charged particle beams such as electron beams, especially ultraviolet rays and far-ultraviolet rays About things.

[0002]

2. Description of the Related Art Positive resists have been widely used for producing integrated circuits. In recent years, however, with the increasing integration of integrated circuits, a positive resist capable of forming a high-resolution resist pattern with high sensitivity has been desired. ing. In general, in order to improve the resolution of a positive resist, there is a method of increasing the numerical aperture (NA) of a stepper during exposure. But,
In this case, a problem occurs in that the depth of focus (focus tolerance) is narrowed, and therefore, it is necessary to improve the resist material at the same time. For example, changing the type of the quinonediazide compound in order to improve the focus tolerance is one corresponding method. However, at that time, the pattern shape may be deteriorated. Increasing the amount of the quinonediazide compound is one of the measures. But,
When the amount of the quinonediazide compound is increased, the developability deteriorates. As described above, in the conventional positive resist, when any one of the resolution, the heat resistance, the focus tolerance, and the developability is improved, other performances are reduced. .

Attempts have been made to improve the performance of a positive resist by adding an additive in addition to a photosensitive agent. For example, JP-A-3-100551 discloses that dihydroapiethyl phthalate is added to increase the resolution. Further, Japanese Patent Application Laid-Open No.
No. 2960 discloses adding di (2-ethylhexyl) adipate or dioctyl adipate. However, although the resolution can be improved by these additives, there is a possibility that the sensitivity is remarkably reduced or the developability is deteriorated.

[0004]

The radiation-sensitive resin composition of the present invention maintains good sensitivity, has excellent resolution and exposure margin, has a good pattern shape, and has a well-balanced characteristic. An object is to provide a radiation-sensitive resin composition suitable as a resist.

[0005]

The radiation-sensitive resin composition of the present invention is represented by (A) an alkali-soluble resin, (B) a quinonediazidesulfonic acid ester compound, and (C) a compound represented by the following general formula (1). It is characterized by containing an aliphatic dibasic acid ester compound.

[0006]

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[In the formula (1), R ₁ and R ₂ are each independently an alkyl group having 1 to 6 carbon atoms, and R ₃ is a methylene group or 2 to 2 carbon atoms.
6 alkylene groups. ]

(A) Alkali-Soluble Resin The “(A) alkali-soluble resin” (hereinafter referred to as “resin (A)”) used in the present invention includes, for example, novolak resin, polyhydroxystyrene or a derivative thereof, Examples thereof include a styrene-hydroxystyrene copolymer or a derivative thereof, and a styrene-maleic anhydride copolymer. Of these, it is preferable to use a novolak resin.

This novolak resin is obtained by polycondensing phenols and aldehydes in the presence of an acid catalyst. Phenols used at this time include, for example, phenol, o-cresol, m-cresol, p-cresol, 2,3-xylenol, 2,4-xylenol,
2,5-xylenol, 3,4-xylenol, 3,5
-Xylenol, 2,3,5-trimethylphenol,
Examples thereof include 3,4,5-trimethylphenol, hydroquinone, catechol, resorcinol, 2-methylresorcinol, pyrogallol, α-naphthol, and β-naphthol. Of these, phenol,
o-cresol, m-cresol, p-cresol,
2,3-xylenol, 2,4-xylenol, 2,5
-Xylenol, 3,4-xylenol, 3,5-xylenol, and 2,3,5-trimethylphenol are preferred. These can be used alone or in combination of two or more.

Particularly, a preferable combination is m-
Cresol / p-cresol, m-cresol / 2,3
-Xylenol, m-cresol / 2,4-xylenol, m-cresol / 2,3,5-trimethylphenol, phenol / 2,3-xylenol / 3,4-xylenol, m-cresol / 2,3-xylenol /
3,4-xylenol and m-cresol / 2,3-
Xylenol / 2,3,5-trimethylphenol and the like can be mentioned. The m-cresol used in this preferred combination is usually at least 30% by weight, preferably at least 50% by weight, based on the total amount of phenols.

The aldehydes to be polycondensed with the phenols include, for example, formaldehyde, trioxane, paraformaldehyde, acetaldehyde, propylaldehyde, phenylacetaldehyde, benzaldehyde, o-hydroxybenzaldehyde, m-hydroxybenzaldehyde, p-hydroxybenzaldehyde, Examples thereof include o-methylbenzaldehyde, m-methylbenzaldehyde, p-methylbenzaldehyde, furfural, 1-naphthaldehyde, 2-naphthaldehyde and 2-hydroxy-1-naphthaldehyde. Of these, especially formaldehyde,
o-Hydroxybenzaldehyde can be suitably used. These can be used alone or in combination of two or more.

The aldehyde is used in an amount of usually 0.5 to 3 mol, preferably 0.6 to 1.5 mol, based on the phenol.
Used in molar proportions. An acid catalyst is used for the polycondensation reaction between phenols and aldehydes. As the acid catalyst, for example, hydrochloric acid, nitric acid, sulfuric acid, acetic acid, oxalic acid and p-toluenesulfonic acid can be used.
The compounding amount is 1 × 10 ⁻⁴ per mol of phenols.
It is 5 × 10 ^-1 mol.

In the above polycondensation reaction, water is usually used as a reaction medium. However, when the phenol used in the reaction does not dissolve in an aqueous solution of aldehydes and becomes heterogeneous from the beginning of the reaction, the reaction medium is , Solvents of alcohols, ethers and ketones can also be used. Examples of alcohols include methanol, ethanol, butanol and propylene glycol monomethyl ether. Examples of the ethers include tetrahydrofuran and dioxane. Examples of ketones include methyl ethyl ketone, methyl isobutyl ketone, 2-heptanone, and the like. The amount of the reaction medium is usually 20 to 500 parts by weight per 100 parts by weight of the reaction raw material. Further, the temperature of the polycondensation reaction can be appropriately adjusted according to the reactivity of the reaction raw materials, but is usually from 10 to 200 ° C. As the reaction method, (1) a method of charging phenols and aldehydes, a catalyst and a solvent at once, and (2) a method of adding phenols and aldehydes as the reaction proceeds can be appropriately adopted.

After completion of the reaction, unreacted raw materials remaining in the system,
In order to remove the acid catalyst and the reaction medium and recover the novolak resin, the temperature of the system is generally set to 130 to 230.
C. and evaporate the volatiles under reduced pressure. Further, the novolak resin thus obtained is, for example, dissolved in a good solvent such as ethyl acetate, methanol and methyl isobutyl ketone, and water, a poor solvent such as n-hexane and n-heptane is added, and the precipitated resin is added. There is also a method of separating a solution layer and obtaining a resin having a relatively high molecular weight.

The polystyrene-equivalent weight average molecular weight (hereinafter, referred to as “Mw”) of the obtained novolak resin is as follows:
Usually, 2,000 to 20,000, and 3,000 to
Preferably, it is 15,000. If this Mw is too large, it may be difficult to uniformly apply the composition to the wafer, and furthermore, the developability and sensitivity may decrease. On the other hand, when Mw is too small, the heat resistance as a resist tends to decrease.

(B) Quinonediazidesulfonic acid ester compound The "(B) quinonediazidesulfonic acid ester compound" (hereinafter referred to as "quinonediazide compound (B)") used in the present invention is not particularly limited. For example, 1,2-benzoquinonediazide-4-sulfonic acid ester of polyhydroxy compound, 1,2-naphthoquinonediazide-4-sulfonic acid ester, 1,2-
Examples include naphthoquinonediazide-5-sulfonic acid ester and 1,2-naphthoquinonediazide-6-sulfonic acid ester. Of these, 1,2-naphthoquinonediazide-4-sulfonic acid ester and 1,2-
Naphthoquinonediazide-5-sulfonic acid ester is preferred.

The quinonediazide compound (B) can be obtained, for example, by reacting a polyhydroxy compound with quinonediazide sulfonyl chloride in the presence of a basic catalyst. In this reaction, the ratio (average esterification ratio) of the quinonediazidesulfonic acid ester to all the hydroxyl groups of the polyhydroxy compound is usually 20 to 100%, preferably 40 to 95%. If the average esterification rate is too low, it is difficult to form a pattern, and if it is too high, there is a possibility that developability will deteriorate and sensitivity will decrease. Here, the polyhydroxy compound used is not particularly limited, and examples thereof include compounds represented by the following general formula.

[0018]

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[In the formula, X _{1 to} X _{15 each} independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, an aryl group having 6 to 10 carbon atoms, or a hydroxyl group.
However, at least one of the groups X _{1 to} X ₅ and X _{6 to} X ₁₀ is a hydroxyl group. Y ₁ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. ]

[0020]

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[In the formula, X _{16 to} X ₃₀ have the same definition as the above X _{1 to} X ₁₅ . Provided that at least one in each group of _{X 16 ~X 2 0, X 21} ~X 25 and X ₂₆ to X ₃₀ is a hydroxyl group. Y _{2 to} Y _{4 are} independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. ]

[0022]

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[In the formula, X _{31 to} X ₄₄ have the same definition as the above X _{1 to} X ₁₅ . Provided that at least one in X ₃₁ to X _{3 5} is a hydroxyl group. Y _{5 to} Y ₈ are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. ]

[0024]

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Wherein X _{45 to} X ₅₈ independently represent a hydrogen atom,
Halogen atom, alkyl group having 1 to 4 carbon atoms, 1 to 1 carbon atom
An alkoxy group of 4, a cycloalkyl group having 5 to 7 carbon atoms or a hydroxyl group. However, at least one of the groups X _{45 to} X ₄₈ and X _{49 to} X ₅₃ is a hydroxyl group. Also, Y ₉
And Y ₁₀ are independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or a cycloalkyl group having 5 to 7 carbon atoms. ]

[0026]

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[Wherein, X₅₉~ X₈₀Is the above X₄₅~ X₅₈When
It is the same definition. Where X₅₉~ X ₆₃, X₆₄~ X₆₇, X
₇₂~ X₇₅And X₇₆~ X₈₀At least one in each group of
Is a hydroxyl group. Also, Y₁₁~ Y₁₈Is independently a hydrogen atom or
Is an alkyl group having 1 to 4 carbon atoms. ]

[0028]

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[Wherein, X _{81 to} X ₁₀₂ are the same as X _{45 to} X ₅₈
Is the same definition as. However, X _{81 to} X ₈₅ , X _{86 to} X ₈₉ ,
At least 1 in each group of X ₉₀ to X ₉₃ and X ₉₄ to X ₉₈
One is a hydroxyl group. Y _{19 to} Y ₂₄ are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. ]

[0030]

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[Wherein, X _{103 to} X ₁₂₀ are the same as X _{45 to} X ₅₈
Is the same definition as. However, X _{103 to} X ₁₀₇ , X _{108 to} X
At least one at _111, each group of X ₁₁₂ to X ₁₁₅ and X ₁₁₆ to X ₁₂₀ is a hydroxyl group. Y _{19 to} Y ₂₄ are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. ]

[0032]

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[Wherein, X _{121 to} X _{123 each} independently have 1 to 1 carbon atoms.
X ₁₂₄ represents a hydrogen atom, an alkyl group, an alkoxyl group or a hydroxyl group, and a and b represent 0 to
An integer of 3 and a + b ≦ 4. ]

[0034]

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[Wherein, X ₁₂₅ and X ₁₂₆ independently represent a hydrogen atom, an alkyl group, an alkoxyl group or a hydroxyl group;
F is an integer of 0 to 3, and c + e ≦ 4 and d + f ≦ 4. ]

[0036]

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[Wherein, X _{127 to} X _{130 each} independently represent a hydrogen atom;
Represents an alkyl group, an alkoxyl group or a hydroxyl group, and g and h are integers of 0 to 2. ]

[0038]

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[Wherein, X _{131 to} X _{134 each} independently represent a hydrogen atom,
Represents an alkyl group, an alkoxyl group or a hydroxyl group, and i and j are integers of 0 to 2. ]

[0040]

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Wherein X _{135 to} X ₁₃₉ are each independently a hydrogen atom,
Represents an alkyl group, an alkoxyl group or a hydroxyl group, and k is 0
整数 2. ]

[0042]

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Wherein X _{140 to} X ₁₄₃ are independently a hydrogen atom,
Represents an alkyl group, an alkoxyl group or a hydroxyl group;
Is an integer of 0 to 2, Y is -CH ₂ -, -C (CH _3)
2- and a divalent organic group represented by the following formula. ]

[0044]

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[0045]

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[Wherein X ₁₄₄ and X _{145 each} independently represent a hydrogen atom, an alkyl group, an alkoxyl group or a hydroxyl group;
And q are integers of 0 to 2. ]

Further, specific compounds represented by the above general formula include the following compounds.

[0048]

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[0049]

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[0050]

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[0051]

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[0052]

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[0053]

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[0054]

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In the composition of the present invention, the amount of the quinonediazide compound (B) is preferably 5 to 60 parts by weight, more preferably 10 to 50 parts by weight, per 100 parts by weight of the resin (A). Also, a quinonediazide compound (B)
Can be used alone or in combination of two or more. It is preferable to use a combination of two or more types because sensitivity can be improved.

Further, 1,2- occupied in the composition of the present invention.
The total amount of quinonediazidosulfonyl residues is preferably from 5 to 50% by weight as a percentage of the total solids of the composition,
10 to 30% by weight is more preferred. If the amount of the quinonediazide compound is too small, there is almost no difference in solubility between the irradiated part and the unirradiated part in a developer (alkaline aqueous solution) when used as a resist, and patterning tends to be difficult. is there. On the other hand, if the compounding amount is too large, the compounded quinonediazide compound is hardly decomposed by short-time irradiation, and the development with a developer may be difficult.

(C) Aliphatic Dibasic Ester Compound The "(C) aliphatic dibasic acid ester compound" used in the present invention is not particularly limited as long as it is represented by the formula (1). Not something. R ₁ and R ₂ in the formula (1)
Examples of the alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, and an n-
Examples thereof include a butyl group, an isobutyl group, a t-butyl group, an n-pentyl group, an isopentyl group, an n-hexyl group and an isohexyl group. When the number of carbon atoms in the alkyl group is 7 or more, phenomena such as remarkable decrease in sensitivity or poor developability and undeveloped portions are observed. Further, an alkyl group having 3 to 4 carbon atoms is more preferable. Specific examples include an n-propyl group, an isopropyl group, an n-butyl group and an isobutyl group.

Examples of the alkylene group having 2 to 6 carbon atoms for R _{3 in} the formula (1) include an ethylene group, a trimethylene group, a tetramethylene group, a pentamethylene group and a hexamethylene group. Specific compounds include di-n-propyl succinate, di-n-butyl succinate, di-n-pentyl succinate, di-n-propyl glutarate, di-n-butyl glutarate, di-n-pentyl glutarate, adipic acid Dimethyl, diethyl adipate, di-n-adipate
Propyl, di-n-butyl adipate, diisobutyl adipate, di-n-pentyl adipate, diisopentyl adipate, di-n-hexyl adipate, diisohexyl adipate, di-n-propyl pimerate, di-n-butyl pimerate, pimerine Examples thereof include di-n-pentyl acid, di-n-propyl suberate, di-n-butyl suberate, and di-n-pentyl suberate. In particular, di-n-butyl succinate, di-n-butyl glutarate, di-n-propyl adipate, di-n-butyl adipate, diisobutyl adipate, di-n-pentyl adipate, diisopentyl adipate and di-n-pimelate Butyl is preferred.

In the composition of the present invention, the amount of the aliphatic dibasic acid ester compound is preferably 0.1 to 20 parts by weight, more preferably 100 parts by weight of the resin (A). Is 0.5 to 10 parts by weight, more preferably 0.5 to 5.0 parts by weight. If the amount of the aliphatic dibasic acid ester compound is too small, the effect of improving the resist performance is small, and if it is too large, the shape tends to deteriorate and scum tends to be generated. Further, the aliphatic dibasic acid ester compounds can be used alone or in combination of two or more.

The composition of the present invention may optionally contain a low molecular weight phenol compound (hereinafter referred to as "dissolution accelerator") for the purpose of promoting the alkali solubility of the resin (A). it can. As the dissolution accelerator, a phenol compound having 2 to 5 benzene rings is preferable, and examples thereof include compounds represented by the following formulas (2-1) to (2-9).

[0061]

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[0062]

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[0063]

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[Here, in the formulas (2-1) to (2-3), a and b are each independently an integer of 0 to 3, provided that a and b are not simultaneously 0. X and y are independently 0 to 3;
A + x ≦ 5, and b + y ≦ 5].

[0065]

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[0066]

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[0067]

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[0068]

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[0069]

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[Here, in the formulas (2-4) to (2-9), a, b and c are each independently an integer of 0 to 3. However, these are not simultaneously 0. X, y and z are each independently an integer of 0 to 3. Further, in the formulas (2-4) and (2-5), b + y ≦ 4. Then, in the expressions (2-6) to (2-9), a + x ≦ 5, b + y
≦ 4 and c + z ≦ 5. ]

The amount of the dissolution accelerator is usually 50 parts by weight or less based on 100 parts by weight of the resin (A).
Preferably it is 5 to 30 parts by weight.

In the composition of the present invention, if necessary, various compounding agents such as a surfactant, a solvent, a coloring agent (dye or pigment), an adhesion aid, a storage stabilizer, and an antifoaming agent are added. be able to. The above-mentioned surfactant is blended in order to improve the coatability and developability of the composition. Examples of the surfactant include polyoxyethylene lauryl ether, polyoxyethylene oleyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene nonyl phenyl ether, polyethylene glycol dilaurate, polyethylene glycol distearate, and the like. These commercial products include “Megafax F171, F172, F173, F47
1, R-07, R-08 "(trade name, manufactured by Dainippon Ink and Chemicals, Inc.)," Florade FC430, FC431 "
(Trade name, manufactured by Sumitomo 3M Limited), "Asahi Guard A
G710, Surflon S-382, SC-101, S
C-102, SC-103, SC-104, SC-10
5, SC-106 "(trade name, manufactured by Asahi Glass Co., Ltd.)," KP3
41 "(trade name, manufactured by Shin-Etsu Chemical Co., Ltd.)," Polyflow
No. 75, no. 95 "(trade name, manufactured by Kyoeisha Yushi Kagaku Kogyo KK) and" NBX-7, NBX-8, NBX-1 "
5 "(trade name, manufactured by Neos) and the like. The amount of the surfactant is usually 2 parts by weight or less based on 100 parts by weight of the solid content of the composition.

Examples of the solvent include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether acetate and propylene glycol. Monopropyl ether acetate, toluene,
Xylene, methyl ethyl ketone, 2-heptanone, 3-
Heptanone, 4-heptanone, cyclohexanone, 2-
Ethyl hydroxypropionate, 2-hydroxy-2-
Ethyl methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutanoate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, ethyl acetate, butyl acetate, Examples thereof include methyl pyruvate and ethyl pyruvate. Furthermore, N-
Methylformamide, N, N-dimethylformamide,
N-methylformanilide, N-methylacetamide,
N, N-dimethylacetamide, N-methylpyrrolidone, dimethylsulfoxide, benzylethyl ether,
Dihexyl ether, acetonylacetone, isophorone, caproic acid, caprylic acid, 1-octanol, 1-
Nonanol, benzyl alcohol, benzyl acetate, ethyl benzoate, diethyl oxalate, diethyl maleate,
High boiling solvents such as γ-butyrolactone, ethylene carbonate, propylene carbonate and ethylene glycol monophenyl ether acetate can also be added. These solvents are used alone or in combination of two or more. The amount of the solvent is such that the resin (A) or the like has a solid content concentration of 5%.
５０50% by weight, preferably 1
5 to 40% by weight is more preferred.

Further, coloring agents such as dyes and pigments are blended in order to reduce the influence of halation upon irradiation.

The composition of the present invention is usually dissolved in the above-mentioned solvent and used in the form of a solution. The composition solution is prepared by dissolving in a solvent such that the concentration of the solid component constituting the composition is, for example, 20 to 40% by weight, and filtering the solution with a filter having a pore size of about 0.2 μm.

To form a resist film using this composition, for example, a composition of the present invention prepared as a solution is coated on a silicon wafer or aluminum or the like by spin coating, casting coating, roll coating or the like. Is applied to the wafer. Next, a resist film is formed by pre-baking the resist film, and the resist film is irradiated with radiation so as to form a desired resist pattern, and is developed with a developer to form a pattern.

The radiation used at this time is g-ray,
Ultraviolet rays such as i-rays are preferably used, but various radiations such as far ultraviolet rays such as excimer laser, X-rays such as synchrotron radiation, and charged particle beams such as electron beams can also be used.

The composition of the present invention may be used, if necessary, after forming a resist film and irradiating with a radiation.
The effect of the present invention can be further improved by performing an operation of heating at 40 ° C. (hereinafter, referred to as “post-bake”) and then performing development.

Examples of the developer used for the resist film include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate,
Ammonia water, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyldiethylamine, dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, choline, pyrrole, piperidine, , 8-Diazabicyclo- [5.4.0] -7-undecene and 1,5-
An alkaline aqueous solution obtained by dissolving an alkaline compound such as diazabicyclo- [4.3.0] -5-nonane in water so as to have a concentration of, for example, 1 to 10% by weight is used. In addition, an appropriate amount of a water-soluble organic solvent, for example, an alcohol such as methanol or ethanol or a surfactant may be added to the developer. When a developer composed of such an alkaline aqueous solution is used, it is generally washed with water after development.

The composition of the present invention has a sensitivity of 600 msec.
Or less (more preferably 500 msec or less, further preferably 450 msec or less), a resolution of 0.32 μm or less (more preferably 0.30 μm or less, and still more preferably 0.28 μm or less), and a focus tolerance of 0.90 μm.
As described above (more preferably 1.10 μm or more, further preferably 1.20 μm or more, particularly preferably 1.25 μm or more), the exposure margin is 1.30 or more (more preferably 1.35 or more, further preferably 1.40 or more). (Especially preferably 1.45 or more), or the cross-sectional shape of the pattern is preferably rectangular. However, each of these characteristics shall be based on the test method shown below. Furthermore, the composition of the present invention can be obtained by variously selecting the preferable ranges of the above-mentioned properties.

[0081]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples. The measurement of the weight average molecular weight (Mw) and each evaluation of the resist in the examples were performed by the following methods. (Method for measuring Mw) GPC column (G200 manufactured by Tosoh Corporation)
0HXL: 2 pieces, G3000HXL: 1 piece, G4000
Gel permeation chromatography using monodispersed polystyrene as a standard (detector: differential refraction) using HXL: 1 tube) under the analysis conditions of flow rate: 1.0 ml / min, elution solvent: tetrahydrofuran, column temperature: 40 ° C. Total). (Method of Measuring Sensitivity) An exposure amount (appropriate exposure amount) when a 0.35 μm line-and-space pattern was resolved one-to-one was measured, and this value was defined as sensitivity. (Measurement Method of Resolution) A scanning electron microscope was used to measure the minimum dimension of a 0.35 μm line-and-space pattern, which was separated without reducing the film thickness when exposed at an appropriate exposure amount, as a resolution. (Measurement method of focus tolerance) Using a scanning electron microscope, the pattern size to be resolved
The deviation of the focus within ± 10% of the mask design dimension was defined as the focus range and used as an evaluation index.
A large focus range means that the lens has good focus tolerance. (Method of Measuring Exposure Margin) A value obtained by dividing an appropriate exposure amount (Eop) by an exposure amount (Ec) at which a 0.35 μm line and space pattern starts to be resolved is defined as an exposure margin (Eop / Ec). ). It should be noted that a large value means that a good exposure margin is provided. (Method of Measuring Pattern Cross Section Shape) A 0.35 μm cross section of the resist pattern was observed using a scanning electron microscope. It is normal if the cross-sectional shape is rectangular. The shape of (A) shown in FIG. 1 is “rectangular”, the shape of (B) is “round”, and the shape of (C) is “lower hem”.

(1) Synthesis of Resin (A) Synthesis Example 1 69.2 g (0.6 m-cresol) was added to an autoclave.
4 mol), 9.8 g (0.08 mol) of 2,3-xylenol, 9.8 g (0.08 mol) of 3,4-xylenol, 55.1 g of 37% by weight aqueous formaldehyde solution
(Formaldehyde: 0.68 mol), 5.0 g (0.04 mol) of oxalic acid dihydrate, 52.6 g of water and 182 g of dioxane were charged. Then, the autoclave was immersed in an oil bath, and the temperature of the reaction solution was reduced to 130 g. C. and polycondensed for 8 hours with stirring. Thereafter, the reaction solution was cooled to room temperature, the content was taken out into a beaker, and the lower layer (resin layer) was separated from the two layers separated in the beaker. Next, the resin layer was concentrated, dehydrated, and dried to obtain a resin (A1) having an Mw of 8,600.

Synthesis Example 2 In a 2 L separable flask equipped with a cooling tube and a stirrer, 48.8 g (0.4 mol) of 2,4-dimethylphenol, 172.8 g (1.6 mol) of m-cresol, 3
129.8 g of a 7% by weight aqueous solution of formaldehyde (formaldehyde: 1.6 mol), oxalic acid dihydrate 12.6
g (0.1 mol) and 554 g of methyl isobutyl ketone
, And the mixture was condensed for 8 hours while maintaining the internal temperature at 90 to 100 ° C. and stirring. This resin solution is deionized water 5
After washing twice with 00 g, 600 g of n-hexane was added, stirred for 30 minutes, and allowed to stand for 1 hour. The supernatant liquid of the precipitated resin layer was removed by decantation. Thereafter, the obtained resin layer is concentrated, dehydrated and dried,
Resin (A2) having a w of 8,300 was obtained.

(2) Synthesis of quinonediazide compound (B) Synthesis Example 3 29.2 g of a compound represented by the following formula (3) was placed in a flask equipped with a stirrer, a dropping funnel and a thermometer under light shielding.
(0.1 mol), 1,2-naphthoquinonediazide-5
67.1 g (0.25 mol) of sulfonic acid chloride and 481 g of dioxane were charged and dissolved with stirring.
Next, the flask was immersed in a water bath controlled at 30 ° C., and when the internal temperature became constant at 30 ° C., 28.3 g (0.28 mol) of triethylamine was added to this solution so that the internal temperature did not exceed 35 ° C. Was added using a dropping funnel and reacted at the same temperature for 2 hours. Thereafter, the precipitated triethylamine hydrochloride was removed by filtration, and the filtrate was poured into a large amount of dilute aqueous hydrochloric acid to precipitate a reaction product.Then, the precipitate was filtered, collected, and dried at 40 ° C. in a vacuum dryer overnight. As a result, a quinonediazide compound (B-1) was obtained.

[0085]

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Synthesis Example 4 In the charged materials, the compound [represented by the above formula (3)] used in the synthesis example 3 was converted to a compound 42.4 g (0.1 mol) represented by the following formula (4). Change, dioxane 54
A quinonediazide compound (B-2) was obtained in the same manner as in Synthesis Example 3 except that the amount was changed to 7 g.

[0087]

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Synthesis Example 5 In the charged materials, the compound [represented by the formula (3)] used in the synthesis example 3 was converted into a compound (37.8 g (0.1 mol) represented by the following formula (5)). Change, 1,2-naphthoquinonediazide-5-sulfonic acid chloride 40.2g
(0.15 mol), 300 g of dioxane, 90 g of N, N-dimethylformamide and 16.7 of triethylamine.
A quinonediazide compound (B-3) was obtained in the same manner as in Synthesis Example 3 except that the amount was changed to g (0.17 mol).

[0089]

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Synthesis Example 6 In the charged materials, the compound [represented by the above formula (3)] used in the synthesis example 3 was converted to a compound 36.4 g (0.1 mol) represented by the following formula (6). 80.5 g of 1,2-naphthoquinonediazide-5-sulfonic acid chloride
(0.3 mol), 585 g of dioxane and 33.4 g (0.33 mol) of triethylamine in the same manner as in Synthesis Example 3 except that the quinonediazide compound (B-4) was used.
I got

[0091]

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Synthesis Example 7 In the charged materials, the compound [represented by the above formula (3)] used in the synthesis example 3 was converted into a compound (64.6 g (0.1 mol) represented by the following formula (7)). Change, 1,2-naphthoquinonediazide-5-sulfonic acid chloride 40.2g
(0.15 mol), 390 g of dioxane, 130 g of N, N-dimethylformamide and 167 g of triethylamine
(0.17 mol), and a quinonediazide compound (B-5) was obtained in the same manner as in Synthesis Example 3.

[0093]

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Synthesis Example 8 In the charged materials, the compound [represented by the above formula (3)] used in the synthesis example 3 was replaced by a compound 39.2 g (0.05 mol) represented by the following formula (8). Change, 1,2-naphthoquinonediazide-5-sulfonic acid chloride 40.2g
(0.125 mol), 476 g of dioxane, and 17.2 g (0.17 mol) of triethylamine in the same manner as in Synthesis Example 3 except that the quinonediazide compound (B-
6) was obtained.

[0095]

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Synthesis Example 9 In the charged materials, the compound [represented by the above formula (3)] used in the synthesis example 3 was converted into a compound (24.8 g (0.05 mol) represented by the following formula (9)). 3,3.5 g of 1,2-naphthoquinonediazide-5-sulfonic acid chloride
(0.125 mol), 350 g of dioxane and 14.1 g (0.14 mol) of triethylamine in the same manner as in Synthesis Example 3 except that the quinonediazide compound (B-
7) was obtained.

[0097]

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Synthesis Example 10 In the charged materials, the compound [represented by the above formula (3)] used in the synthesis example 3 was converted into a compound (24.8 g (0.05 mol) represented by the following formula (10)). 1,3-naphthoquinonediazide-5-sulfonic acid chloride 33.5
g (0.125 mol), 350 g of dioxane and 14.1 g (0.14 mol) of triethylamine.
By the same operation as in Synthesis Example 3, the quinonediazide compound (B
-8) was obtained.

[0099]

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(3) Synthesis of Aliphatic Dibasic Ester Compound (C) Synthesis Example 11 28.6 g (0.1 mol) of adipic acid, n-pentanol were placed in a flask equipped with a stirrer, a dropping funnel and a thermometer. 44.1 g (0.5 mol) and 130 g of dioxane were charged, 3 ml of sulfuric acid was added with stirring, and the mixture was refluxed for 6 hours to be reacted. After allowing the flask to cool, the reaction solution was diluted with distilled water, and the organic layer was separated with a separating funnel, and washed with a 10% by weight aqueous sodium hydrogen carbonate solution. After the solvent was distilled off, the fraction was purified by distillation to obtain di-n-pentyl adipate ((C-3) below).

Synthesis Example 12 In the charged materials, the adipic acid used in Synthesis Example 11 was changed to 24.4 g (0.1 mol) of glutaric acid, and n-
Except that pentanol was changed to 37.1 g (0.5 mol) of n-butanol, n-butyl glutarate ((C-4) below) was obtained in the same manner as in Synthesis Example 11.

Synthesis Example 13 In the charge materials, adipic acid used in Synthesis Example 11 was changed to 27.2 g (0.1 mol) of pimelic acid, and n-
Except that pentanol was changed to 37.1 g (0.5 mol) of n-butanol, n-butyl pimerate ((C-5) shown below) was obtained in the same manner as in Synthesis Example 11.

(3) Formation of resist pattern Examples 1 to 11 Resins (A), quinonediazide compounds (B), and the composition ratios shown in Table 1 (where "parts" indicate "parts by weight")
The aliphatic dibasic acid ester compound, the dissolution promoter and the solvent 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 solution-type radiation-sensitive resin composition. In addition, the amount of the resin (A) shown in Table 1 is an amount in terms of solid content. The following aliphatic dibasic acid ester compounds, dissolution promoters and solvents were used (the same applies to Comparative Examples). In Table 1,
"*" Indicates that it is not included in the scope of the present invention. Also,
The numerical value in parentheses next to the numerical value in the column indicating the amount (parts) of the quinonediazide compound (B), the aliphatic dibasic acid ester compound and the dissolution promoter was 100 parts by weight of the resin (A). The amount (parts) of the case.

In Table 1, the types of the dissolution promoter and the solvent used in each Example and each Comparative Example are shown below. Among the aliphatic dibasic acid ester compounds, C-1, C-2, C-2
Commercial products were used for both -6 and C-7. (Aliphatic dibasic acid ester compound) C-1: di-n-butyl adipate C-2: di-isobutyl adipate C-3: di-n-pentyl adipate C-4: di-n-butyl glutarate C-5: Di-n-butyl pimerate C-6: di (2-ethylhexyl) adipate C-7: di-n-octyl adipate (dissolution promoter) α: 1,1-bis (4-hydroxyphenyl) -1- [ 4- {1- (4-hydroxyphenyl)
-1-methylethyl @ phenyl] ethane β: 1,1-bis (4-hydroxyphenyl) -1-phenylethane γ: 1,1-bis (2,5-dimethyl-4-hydroxyphenyl) acetone (solvent) a-1: 2-heptanone a-2: 3-heptanone b-1: methyl 3-methoxypropionate b-2: ethyl 3-ethoxypropionate b-3: ethyl 3-methoxypropionate c-1: ethyl lactate c-2: γ-butyrolactone

Each solution obtained above was applied on a 6-inch silicon wafer having a silicon oxide film on its surface using a spinner (spin coater), and then prebaked on a hot plate at 90 ° C. for 120 seconds. Thus, a resist film having a thickness of 0.86 μm was formed. Then, through a reticle, “NSR-2205i12D” manufactured by Nikon Corporation
After exposing to ultraviolet light with a wavelength of 365 nm (i-line) from a “reduction projection exposure machine” (lens numerical aperture: 0.57), the film was post-baked on a hot plate at 110 ° C. for 60 seconds, and then 2.3.
By developing with an 8% by weight aqueous solution of tetramethylammonium hydroxide, washing with ultrapure water and drying,
Pattern formation was performed. Table 2 shows the obtained results.

Comparative Examples 1 to 4 In the same manner as in Examples 1 to 11, except that the aliphatic dibasic acid ester compound was not blended according to the composition ratios shown in Table 1 (Comparative Examples 1 and 2). A pattern was formed, and the characteristics of the obtained resist pattern were examined in the same manner as in the example. The results are also shown in Table 2.

[0107]

[Table 1]

[0108]

[Table 2]

According to Table 2, in Comparative Examples 1 and 2 which did not contain the aliphatic dibasic acid ester compound, the sensitivity was good, but the resolution was poor at 0.34 μm.
The exposure margin was as low as 1.27 and 1.28, respectively. Furthermore, the focus tolerance is 0.8 μm for both.
m and a low value. In Comparative Example 2, the pattern cross-sectional shape was “round”. In Comparative Examples 3 and 4 using an aliphatic dibasic acid ester compound not included in the scope of the present invention, the sensitivity was 650, respectively.
630 msec, which was bad, and the pattern cross-sections were “round” and “lower hem”, respectively. As described above, Comparative Examples 1 to 4 did not have a sufficient balance of characteristics.

On the other hand, in Examples 1 to 11, in all Examples, the sensitivity was as good as 410 to 550 msec, and the resolution was 0.26 to 0.28 μm.
And an excellent value, and the pattern cross-sectional shape was also “rectangular”. Further, in all the examples, the focus tolerance was as good as 1.20 to 1.30 μm, and the exposure margin was as excellent as 1.40 to 1.46. From these, it was found that the examples of the present invention were good in all of the above-mentioned respective characteristics and were excellent in the balance performance.

[0111]

As described above, the radiation-sensitive resin composition of the present invention can be applied as a positive resist in a uniform amount with a small coating amount, and is less likely to cause pattern defects, and has a high resolution having an excellent pattern shape. A resist pattern can be formed with high sensitivity. Accordingly, the composition of the present invention can be suitably used particularly for producing a semiconductor integrated circuit.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically illustrating a cross-sectional shape in a depth direction of a resist pattern.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Atsushi Nakamura, 2-11-24 Tsukiji, Chuo-ku, Tokyo Inside JSR Co., Ltd. (72) Inventor Hiroaki Nemoto 2-11-24 Tsukiji, Chuo-ku, Tokyo JSR In the company (72) Inventor Koji Yukimoto 2-11-24 Tsukiji, Chuo-ku, Tokyo FJ-term in the reference company 2R025 AA02 AA03 AA10 AA18 AB16 AC01 AC08 AD03 BE01 CB42 CC20

Claims (1)

[Claims] 1. A composition comprising (A) an alkali-soluble resin, (B) a quinonediazidesulfonic acid ester compound, and (C) an aliphatic dibasic acid ester compound represented by the following general formula (1). Radiation-sensitive resin composition. Embedded image [In the formula (1), R ₁ and R ₂ are each independently an alkyl group having 1 to 6 carbon atoms, and R ₃ is a methylene group or an alkylene group having 2 to 6 carbon atoms. ]