JP2743697B2 - Positive resist composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positive resist composition, and more particularly to a positive resist composition for fine processing required for manufacturing semiconductor devices, magnetic bubble memory devices, integrated circuits and the like. .

[0002]

2. Description of the Related Art In the manufacture of semiconductors, a photosensitive film is formed by coating a resist on the surface of a silicon wafer, and a latent image is formed by irradiating light, and then developed to form a negative or positive image. 2. Description of the Related Art A semiconductor element is formed by a lithography technique. Conventionally, as a resist composition for forming a semiconductor device, a negative resist comprising a cyclized polyisoprene and a bisdiazide compound has been known. However, since this negative resist is developed with an organic solvent, the swelling is large and the resolution is limited,
It has a disadvantage that it cannot cope with the manufacture of a highly integrated semiconductor.

[0003] On the other hand, a positive resist comprising an alkali-soluble novolak resin and a quinonediazide compound, which undergoes alkali development, does not swell and is essentially excellent in resolution. It has come to be. Further, the resolution has been improved by improving the performance of the positive resist and the performance of the exposing machine, and it has become possible to form a fine pattern of 1 μm or less. By the way, 1
In the formation of a fine pattern of not more than μm, especially not more than 0.8 μm, it is necessary to control the size of the resist more strictly. However, conventional positive resist compositions have not always yielded satisfactory results, and a positive resist composition having good dimensional control has been strongly demanded.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a positive resist composition having a good balance of various properties such as sensitivity, residual film ratio, and resolution. Another object of the present invention is to provide a positive resist excellent in so-called exposure latitude, which has a small dimensional change with respect to an exposure amount, particularly in fine processing of 1 μm or less. The present inventors have conducted intensive studies to overcome the problems of the prior art, and as a result, in a positive resist composition containing an alkali-soluble resin and a quinonediazide sulfonic acid ester-based photosensitizer, a specific polyhydroxy By allowing at least a part of the hydroxyl groups of the compound to contain a compound modified by at least one conversion reaction selected from the group consisting of sulfonic acid esterification, carboxylic acid esterification, and etherification, the sensitivity, the residual film ratio and It has been found that the exposure latitude can be significantly improved without substantially lowering the resolution, and the present invention has been completed based on this finding. This compound (c) is a compound that does not cause a change in solubility in an alkaline aqueous solution when exposed to ultraviolet light of 300 to 500 nm. The present invention has been completed based on these findings.

[0005]

Thus, according to the present invention, (a) 100 parts by weight of an alkali-soluble phenolic resin, (b) 1 to 100 parts by weight of a quinonediazidesulfonic acid ester-based photosensitizer, and (c) the specifics described below. average 20-100% sulfonic acid esterification of the hydroxyl groups of the polyhydroxy compound _{(-OH) (-OSO 2 R)} , from the group consisting of carboxylic acid ester of (-OCOR), and etherification (-O-R) At least one selected conversion reaction (formula
Wherein R is an alkyl group, a substituted alkyl group, an alkenyl
Group, substituted alkenyl group, aryl group, substituted aryl group,
An arylalkyl group or a substituted arylalkyl group
is there. ) (However, this compound
Is one hydroxyl group at a specific position of each polyhydroxy compound
Only a compound having a structure modified only by the conversion reaction
Except when. ) Modified by compounds 1 to 10
There is provided a positive resist composition containing 0 parts by weight and (d) a solvent in an amount sufficient to dissolve the above components.
Hereinafter, the present invention will be described in detail.

Alkali-soluble phenol resin (a) Examples of the alkali-soluble phenol resin used in the present invention include a condensation reaction product of a phenol and an aldehyde, a condensation reaction product of a phenol and a ketone, and vinyl phenol. Polymers, isopropenylphenol polymers, and hydrogenation reaction products of these phenolic resins. Specific examples of the phenols used herein include phenol, cresol, xylenol, ethylphenol, propylphenol, butylphenol, monovalent phenols such as phenylphenol, resorcinol, pyrocatechol, hydroquinone, bisphenol A, phloroglucinol, pyrogallol And other polyhydric phenols. Specific examples of aldehydes include formaldehyde, acetaldehyde, benzaldehyde, terephthalaldehyde, and the like. Specific examples of ketones include acetone, methyl ethyl ketone, diethyl ketone, diphenyl ketone, and the like. These condensation reactions can be performed according to a conventional method.

The vinylphenol-based polymer is selected from a homopolymer of vinylphenol and a copolymer of vinylphenol with a component copolymerizable with vinylphenol. Specific examples of the copolymerizable component include acrylic acid, methacrylic acid, styrene, maleic anhydride, maleic imide, vinyl acetate, acrylonitrile, and derivatives thereof. The isopropenylphenol-based polymer is selected from a homopolymer of isopropenylphenol and a copolymer with a component copolymerizable with isopropenylphenol. Specific examples of the copolymerizable component include acrylic acid, methacrylic acid, styrene, maleic anhydride, maleic imide, vinyl acetate, acrylonitrile, and derivatives thereof.

[0008] When a hydrogenation reaction product of a phenol resin is used, the product can be produced by any known method. For example, it can be achieved by dissolving a phenol resin in an organic solvent and introducing hydrogen in the presence of a homogeneous or heterogeneous hydrogenation catalyst. These alkali-soluble phenol resins can be used as they are, but those separated by a known means and whose molecular weight and molecular weight distribution are controlled may be used. Further, these alkali-soluble phenol resins may be used alone or in combination of two or more.

The positive resist composition of the present invention may contain, for example, a copolymer of styrene with acrylic acid, methacrylic acid or maleic anhydride in order to improve developability, storage stability and heat resistance. Polymers, copolymers of alkenes and maleic anhydride, vinyl alcohol polymers, vinylpyrrolidone polymers, rosin, shellac and the like can be added. The addition amount is from 0 to 50 parts by weight, preferably from 5 to 20 parts by weight, based on 100 parts by weight of the alkali-soluble phenol resin.

[0010] Quinonediazide sulfonic acid ester type photosensitive
Agent (b) The photosensitive agent used in the present invention is not particularly limited as long as it is a quinonediazidesulfonic acid ester. Such a quinonediazidesulfonic acid ester can be obtained by converting quinonediazidesulfonic acid into sulphonyl chloride with chlorosulfonic acid and condensing the obtained quinonediazidosulphonylchloride with a hydroxy compound according to a conventional method. For example, a hydroxy compound and 1,2
A predetermined amount of -naphthoquinonediazide-5-sulfonyl chloride is dissolved in a solvent such as dioxane, acetone or tetrahydrofuran, and a basic catalyst such as triethylamine, pyridine, sodium carbonate, sodium hydrogencarbonate, sodium hydroxide or potassium hydroxide is added. After the reaction, the obtained product can be prepared by washing with water and drying.

The hydroxy compound used here is not particularly limited, and for example, a known compound having a phenolic hydroxyl group can be used. A typical example is
2,3,4-trihydroxybenzophenone, 2,4
4'-trihydroxybenzophenone, 2,3,4
4'-tetrahydroxybenzophenone, 2,4
2 ', 4'-tetrahydroxybenzophenone, 2,
Polyhydroxybenzophenones such as 3,4,2 ', 4'-pentahydroxybenzophenone; gallic esters such as methyl gallate, ethyl gallate and propyl gallate; 2,2-bis (4-hydroxyphenyl) propane Polyhydroxybisphenylalkanes such as 2,2-bis (2,4-dihydroxyphenyl) propane; tris (4-hydroxyphenyl) methane;
And polyhydroxytrisphenylalkanes such as 1,1-tris (4-hydroxyphenyl) ethane.

The quinonediazidesulfonic acid ester moiety of the photosensitizer used in the present invention is not particularly limited. For example, 1,2-benzoquinonediazide-4-
Sulfonate, 1,2-naphthoquinonediazide-
O-Quinone diazide sulfones such as 4-sulfonic acid ester, 1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,1-naphthoquinonediazide-4-sulfonic acid ester, and 2,1-naphthoquinonediazide-5-sulfonic acid ester Acid esters and other quinonediazidesulfonic acid esters. The photosensitive agents used in the present invention may be used alone or in combination of two or more. The amount of the photosensitive agent is usually 1 to 100 parts by weight of the alkali-soluble phenol resin.
To 100 parts by weight, preferably 3 to 40 parts by weight. If the amount is less than 1 part by weight, it becomes difficult to form a pattern. If the amount exceeds 100 parts by weight, the sensitivity is lowered and development residue tends to occur.

Compound (c) In the compound (c) used in the present invention, at least a part or all of the hydroxyl groups of the polyhydroxy compound are selected from the group consisting of sulfonic acid esterification, carboxylic acid esterification, and etherification. It is a compound modified by one kind of conversion reaction. The compound (c) has a structure in which a hydroxyl group is substituted with a sulfonic acid ester group, a carboxylic acid ester group, an ether group, or two or more of these groups. Since this compound is in a form in which a hydroxyl group is modified or protected, it may be hereinafter referred to as a capped compound. The compound having a structure in which at least a part of the hydroxyl group of the polyhydroxy compound is sulfonic acid esterified and / or carboxylic acid esterified is the same as the synthesis method of quinonediazide sulfonic acid ester, and the polyhydroxy compound and sulfonic acid halide and / or It can be synthesized by reacting a carboxylic acid halide in the presence of a basic catalyst. Carboxylic acid esterification can also be performed by reacting a polyhydroxy compound with an acid anhydride according to a known method.

The compound having a structure in which at least a part of the hydroxyl groups of the polyhydroxy compound is etherified can be prepared by reacting the hydroxy compound with a halogenated compound or dialkyl sulfate as an etherifying agent in the presence of a basic catalyst. Can be synthesized. The polyhydroxy compound used here is a polyhydroxy compound having two or more phenolic hydroxyl groups. Examples of such a polyhydroxy compound include the following general formulas [I] to
The polyhydroxy compound represented by [VI] can be mentioned. General formula [I]

[0015]

Embedded image (R ^{1 to} R ⁴ are independently selected from hydrogen, halogen, hydroxyl, C _{1 to} C ₄ alkyl and C _{2 to} C ₅ alkenyl. R ^{5 to} R ⁶ : hydrogen, halogen and C alkyl group ₁ -C _4, are each independently selected R ⁷ ~R ^10:.. selected from an alkyl group of hydrogen and C ₁ -C _4, independently) formula II

[0016]

Embedded image (R ¹ to R ⁶ : hydrogen, halogen , C _{1 to} C ₄ alkyl group,
Each is independently selected from a C ₂ -C ₅ alkenyl group, a C ₁ -C ₆ alkoxy group and a substituted alkoxy group. R ⁷ : hydrogen, halogen, hydroxyl group, C ₁ -C ₄ alkyl
Group, alkenyl Le group C ₂ -C _5, alkoxy groups of C ₁ -C ₆
Or a substituted alkoxy group. R ^8: hydrogen or an alkyl group of C ₁ -C _4. ) General formula [III]

[0017]

Embedded image (R ^{1 to} R ⁶ : independently selected from hydrogen, halogen, a C _{1 to} C ₄ alkyl group and a C _{2 to} C ₅ alkenyl group. R ^{7 to} R ⁸ : hydrogen, halogen and C ₁ to alkyl group C _4, are each independently selected R ⁹ ~R ^11:.. is selected from an alkyl group of hydrogen and C ₁ -C _4, independently) general formula [IV]

[0018]

Embedded image (A: -S-, -O-, -CO-, -COO-, -SO
—, —SO ₂ — or —CR ⁷ R ⁸ —. However,
R ⁷ to R ⁸ represents hydrogen, an alkyl group having C ₁ -C _4, alkenyl group and phenyl group of C ₂ -C _5, are each independently selected. R ^{1 to} R ⁵ : hydrogen, halogen, hydroxyl group, C _{1 to} C ₄ alkyl group, C _{2 to} C ₅ alkenyl group, C _{1 to} C ₆ alkoxy group and group represented by formula (IV-1) And at least three of them are each independently a group represented by the general formula (IV-1). ) General formula (IV-1)

[0019]

Embedded image (R ^{6 is} hydrogen, halogen, a C ₁ -C ₄ alkyl group or a C ₂ -C ₅ alkenyl group, and n is 0, 1, or 2.) The general formula [V]

[0020]

Embedded image (A: an alkylene group, a substituted alkylene group, an alkenylene group or a substituted alkenylene group. R ^{1 to} R ⁶ : each independently from hydrogen, halogen , a C _{1 to} C ₄ alkyl group and a C _{1 to} C ₄ alkoxy group General formula [VI]

[0021]

Embedded image (R ^{1 to} R ⁶ : independently selected from hydrogen, halogen, a C _{1 to} C ₄ alkyl group and a C _{2 to} C ₅ alkenyl group. R ^{7 to} R ⁸ : hydrogen, halogen and C ₁ to Each independently selected from C ₄ alkyl groups, R ^{9 to} R ¹⁴ : each independently selected from hydrogen and C _{1 to} C ₆ alkyl groups.) Polyhydroxy represented by the general formula [I] Examples of the compound include compounds described in Japanese Patent Application No. 1-342194, and the following compounds are exemplified.

[0022]

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[0023]

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[0024]

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[0025]

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[0026]

Embedded image As an example of the polyhydroxy compound represented by the general formula [II], there is a compound described in Japanese Patent Application No. 1-342195, and the following compounds are exemplified.

[0027]

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[0028]

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[0029]

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[0030]

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[0031]

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[0032]

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[0033]

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[0034]

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[0035]

Embedded image As an example of the polyhydroxy compound represented by the general formula [III], there is a compound described in Japanese Patent Application No. 1-342193, and the following compounds are exemplified.

[0036]

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[0037]

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[0038]

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[0039]

Embedded image As an example of the polyhydroxy compound represented by the general formula [IV], there is a compound described in Japanese Patent Application No. 1-342195, and the following compounds are exemplified.

[0040]

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[0041]

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[0042]

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[0043]

Embedded image Examples of the polyhydroxy compound represented by the general formula [V] include a compound described in Japanese Patent Application No. 2-102315, and the following compounds are exemplified.

[0044]

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[0045]

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[0046]

Embedded image Examples of the polyhydroxy compound represented by the general formula [VI] include compounds described in Japanese Patent Application No. 1-342193, and the following compounds are exemplified.

[0047]

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[0048]

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[0049]

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These polyhydroxy compounds are:
They are used alone or in combination of two or more. In these polyhydroxy compounds, at least a part of the hydroxyl group is sulfonated, carboxylic esterified or etherified, and is represented by the following general formula [VI
As shown in I], [VIII], or [IX], a sulfonic ester group, a carboxylic ester group, or an ether group is introduced. Two or more of these groups may be introduced. -OSO ₂ R [VII] -OCOR [VIII] -OR [IX] In these formulas, R represents an alkyl group, a substituted alkyl group, an alkenyl group, a substituted alkenyl group, an aryl group, a substituted aryl group, an arylalkyl Represents a substituted arylalkyl group.

As the alkyl group, an alkyl group having 1 to 5 carbon atoms is preferable. As the substituted alkyl group, for example,
Halogen atoms such as chlorine and bromine are preferred. The alkenyl group is preferably an alkenyl group having 2 to 5 carbon atoms.
As the substituent of the substituted alkenyl group, an alkyl group having 1 to 5 carbon atoms and a halogen atom such as chlorine and bromine are preferable.
As the aryl group, a phenyl group and a naphthyl group are preferable. Examples of the substituent of the substituted aryl group include an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, an acetamido group, a nitro group, a halogen such as chlorine and bromine. Atom, phenyl group,
And the like. The number of substituents in the substituted aryl group is usually 1 to 3, and may be substituted with two or more substituents. As the arylalkyl group, a benzyl group and a naphthylmethyl group are preferable. Examples of the substituent of the substituted arylalkyl group include various substituents of the above-mentioned substituted aryl group.

The sulfonic acid halide and / or carboxylic acid halide used for sulfonic acid esterification and / or carboxylic acid esterification is not particularly limited, but specific examples thereof include the following compounds. Examples of the sulfonic acid halide include methanesulfonic acid chloride, methanesulfonic acid chloride, ethanesulfonic acid chloride, n-propanesulfonic acid chloride, and n
-Alkanesulfonic acid halides such as butyric acid chloride and pentanesulfonic acid chloride; substituted alkanesulfonic acid halides such as chloromethylsulfonic acid chloride, dichloromethylsulfonic acid chloride, trichloromethylsulfonic acid chloride and 2-chloroethylsulfonic acid chloride. Alkenesulfonic acid halides such as ethenesulfonic acid chloride and propenesulfonic acid chloride; arylsulfonic acid halides such as benzenesulfonic acid chloride, benzenesulfonic acid chloride, 1-naphthalenesulfonic acid chloride and 2-naphthalenesulfonic acid chloride; p -Toluenesulfonic acid chloride, p-ethylbenzenesulfonic acid chloride, p-
Xylenesulfonic acid chloride, 2,4,6-triisopropylbenzenesulfonic acid chloride, p-styrenesulfonic acid chloride, p-methoxybenzenesulfonic acid chloride, p-dimethylaminobenzenesulfonic acid chloride, p-acetamidobenzenesulfonic acid chloride, Substituted arylsulfonic acid halides such as p-phenylazobenzenesulfonic acid chloride, m-nitrobenzenesulfonic acid chloride, p-nitrobenzenesulfonic acid chloride, p-chlorobenzenesulfonic acid chloride, and 2,4,5-trichlorobenzenesulfonic acid chloride. No.

Examples of the carboxylic acid halide include alkane carboxylic acid halides such as acetic acid chloride, acetic acid bromide, propionic acid chloride, propionic acid bromide, butyric acid chloride, isopropane carboxylic acid chloride, valeric acid chloride and pentane carboxylic acid chloride; Substituted alkane carboxylic acid halides such as chloroacetic acid chloride, dichloroacetic acid chloride and trichloroacetic acid chloride; alkene carboxylic acid halides such as acrylic acid chloride and crotonic acid chloride; substituted alkene carboxylic acids such as methacrylic acid chloride and α-ethylacrylic acid chloride Acid halides; benzoic acid chloride, benzoic acid bromide, 1-naphthoic acid chloride,
Aryl carboxylic acid halides such as 2-naphthoic acid chloride; substituted aryls such as 4-methylbenzoic acid chloride, 4-ethylbenzoic acid chloride, 2,4-dimethylbenzoic acid chloride and 3,4,5-trimethoxybenzoic acid chloride; Carboxylic acid halides; and the like.

Examples of the etherifying agent for etherifying at least a part of the hydroxyl groups of the polyhydroxy compound include:
Halogenated compounds and dialkyl sulfates are used. Examples of the halogenated compound include substituted aryl halides such as α-chloro-p-xylene and 1-chloromethylnaphthalene; arylalkyl halides such as α-benzyl chloride; p-methoxybenzyl chloride;
Substituted arylalkyl halides such as bromobenzyl bromide; and the like. Examples of the dialkyl sulfate include dimethyl sulfate and diethyl sulfate.

The ratio of the hydroxyl groups of the polyhydroxy compound modified by at least one conversion reaction selected from the group consisting of sulfonic acid esterification, carboxylic acid esterification, and etherification (hereinafter referred to as “capping ratio”). ) Average 20 to 100%. Compound (c) is
When all the hydroxyl groups of the polyhydroxy compound have been modified by the conversion reaction, the capping ratio is evaluated as 100%. In other cases, the degree of modification is usually different from that of the unmodified product. The capping ratio is defined as the average of the degree of modification of the hydroxyl group in these mixtures, since the mixture is obtained as a mixture with the capping compound.

When the reagent used for sulfonic acid esterification, carboxylic acid esterification, or etherification is referred to as a capping agent, the capping ratio in sulfonic acid esterification and / or carboxylic acid esterification is specifically as follows: It is calculated by the following formula from (mx) obtained by multiplying the number of moles (x) of the charged hydroxy compound by the number (m) of OH groups and the number of moles (y) of the charged capping agent. Capping ratio = (y / mx) × 100 (%) The capping ratio in etherification (also referred to as etherification ratio) is determined by ¹ H-NMR based on the proton signal of the hydroxyl group of the etherified hydroxy compound and the proton signal of the ether group. Can be determined by measuring the area ratio.

The compounding amount of the compound (c) used in the present invention is usually in the range of 1 to 100 parts by weight based on 100 parts by weight of the alkali-soluble phenol resin. The preferred range varies depending on the type of the cap compound, the type of the alkali-soluble phenol resin to be combined, and the type of the photosensitive agent, but is preferably about 2 to 60 parts by weight, more preferably 3 to 30 parts by weight. If this amount is too small,
If the effects of the present invention cannot be exhibited, and conversely, if it is too large, the resolution and heat resistance may decrease. Compound (c)
Are used alone or in combination of two or more.

(Other Components) The positive resist composition of the present invention is usually used by dissolving it in a solvent in order to apply it to a substrate to form a resist film. Examples of the solvent include ketones such as acetone, methyl ethyl ketone, cyclohexanone, and cyclopentanone;
-Propyl alcohol, iso-propyl alcohol,
alcohols such as n-butyl alcohol and cyclohexanol; ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether and dioxane; alcohol ethers such as ethylene glycol monomethyl ether and ethylene glycol monoethyl ether; propyl formate, butyl formate and acetic acid Esters such as propyl, butyl acetate, methyl propionate, ethyl propionate, methyl acetate, ethyl acetate, methyl lactate, ethyl lactate; cellosolve esters such as cellosolve acetate, methyl cellosolve acetate, ethyl cellosolve acetate, propyl cellosolve acetate, and butyl cellosolve acetate Propylene glycol, propylene glycol monomethyl ether, prolene glycol monomer Ether acetate, propylene glycol monoethyl ether acetate, propylene glycol such as propylene glycol monomethyl ether; diethylene glycol monomethyl ether,
Diethylene glycols such as diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol getyl ether, diethylene glycol methyl ethyl ether; halogenated hydrocarbons such as trichloroethylene; aromatic hydrocarbons such as toluene and xylene; dimethylacetamide, dimethylformamide, N- And polar solvents such as methylacetamide. These may be used alone or in combination of two or more. In the positive resist composition of the present invention, if necessary, a dye, a surfactant, a storage stabilizer,
Compatible additives such as sensitizers, striation inhibitors, and plasticizers can be included.

As a developer for the positive resist composition of the present invention, an aqueous alkali solution is used. Specifically, sodium hydroxide, potassium hydroxide, sodium silicate,
Inorganic amines such as ammonia; primary amines such as ethylamine and propylamine; second amines such as diethylamine and dipropylamine; tertiary amines such as trimethylamine and triethylamine; dimethylmethanolamine and triethanolamine Alcohol amines; tetramethylammonium hydroxide,
Examples include quaternary ammonium salts such as tetraethylammonium hydroxide, trimethylhydroxymethylammonium hydroxide, triethylhydroxymethylammonium hydroxide, and trimethylhydroxyethylammonium hydroxide. Further, if necessary, methanol, ethanol,
An appropriate amount of a water-soluble organic solvent such as propanol or ethylene glycol, a surfactant, a storage stabilizer, or a dissolution inhibitor for a resin can be added.

[0060]

The present invention will be described more specifically below with reference to examples and comparative examples. In the examples, parts and%
Are by weight unless otherwise specified. In the following examples and comparative examples, methods for measuring physical properties are as follows. (1) Sensitivity: represents the exposure time during which a 1: 1 line & space pattern of 0.65 μm can be formed as designed. (2) Resolution: Represents the limit resolution under the above exposure conditions. (3) Residual film ratio: Indicates the ratio of the resist film thickness before and after development. (4) Exposure latitude: The relationship between the exposure time and the pattern dimension of 0.65 μm is graphed, the variation of the exposure time that can keep the variation of the pattern dimension within ± 5% of the design dimension is determined, and this variation is used as the sensitivity. Represents the value divided by.

Synthesis Example 1 (Synthesis Example 1 of Alkali-Soluble Phenolic Resin) A mixture of m-cresol / p-cresol (40/60), a 37% aqueous solution of formalin and oxalic acid were each added to 0.75 of the total amount of cresol. The mixture was placed in a flask equipped with a cooling tube and a stirrer in a molar amount and a molar ratio of 0.03, and reacted at 95 to 100 ° C. for 3 hours. Thereafter, the temperature was raised to 100 ° C. or higher, water was distilled off over 2 hours, and the temperature was further raised to 170 ° C. for 10 to 30 m.
After distillation under reduced pressure at mHg to remove unreacted monomers and water, the molten resin was returned to room temperature and collected. The polystyrene-equivalent weight average molecular weight of this novolak resin measured by gel permeation chromatography (GPC) was 8,800.

[Synthesis Example 2] (Synthesis Example 2 of Alkali-Soluble Phenolic Resin) A mixture of m-cresol / p-cresol (50/50), a 37% formalin aqueous solution and oxalic acid were each added to 0.75 of the total amount of cresol. The mixture was placed in a flask equipped with a cooling tube and a stirrer in a molar amount and a molar ratio of 0.03, and reacted at 95 to 100 ° C. for 3 hours. Thereafter, the temperature was raised to 100 ° C. or higher to distill off water, and further, the temperature was raised to 170 ° C., and vacuum distillation was performed at 10 to 30 mmHg to remove unreacted monomers and water. Collected. The weight average molecular weight of this novolak resin in terms of polystyrene determined by GPC was 9
It was 100.

[Synthesis Example 3] (Synthesis of photosensitizer) 2,3,4,4'-tetrahydroxybenzophenone and 1,2-naphthoquinonediazide-5-sulfonic acid in an amount corresponding to 85 mol% of the hydroxyl groups Chloride was dissolved in dioxane to give a 10% solution. 20-25 ° C
While controlling the temperature, triethylamine was converted to 1,2-naphthoquinonediazide-5-sulfonic acid chloride.
Two equivalents were added dropwise over 30 minutes, and the reaction was completed by holding for another 4 hours. The precipitated salt was separated by filtration and poured into a 0.2% aqueous solution of oxalic acid 10 times the amount of the reaction solution. The precipitated solid was filtered, washed with ion-exchanged water, and dried under vacuum to obtain a quinonediazidesulfonic acid ester-based photosensitizer.

[Synthesis Example 4] (Synthesis of Compound A) Compound (17) as a polyhydroxy compound and methanesulfonic acid chloride corresponding to 40 mol% of the hydroxyl groups of this compound as a capping agent were dissolved in dioxane to give 10%. % Solution. While controlling the temperature at 20 to 25 ° C., 1.2 equivalents of methanesulfonic acid chloride was added dropwise over 30 minutes while triethylamine was added, and the reaction was completed by further holding for 6 hours. The precipitated salt was separated by filtration and poured into a 0.2% aqueous solution of oxalic acid 10 times the amount of the reaction solution. The precipitated solid was filtered to obtain a 20% ethyl ether solution. After washing with an equivalent amount of ion-exchanged water, concentration by distillation removal and vacuum drying were performed to obtain Compound A.

Synthesis Example 5 (Synthesis of Compound B) Compound (17) as a polyhydroxy compound and p-toluenesulfonic acid chloride corresponding to 100 mol% of the hydroxyl groups of this compound as a capping agent were dissolved in dioxane. To give a 10% solution. While controlling the temperature at 20 to 25 ° C., triethylamine was added dropwise in an amount of 1.3 equivalents of p-toluenesulfonic acid chloride over 30 minutes,
The reaction was maintained for a further 6 hours to complete the reaction. The precipitated salt was separated by filtration and poured into a 0.2% aqueous solution of oxalic acid 10 times the amount of the reaction solution. The precipitated solid was filtered, washed with ion-exchanged water, and vacuum dried to obtain Compound B.

[Synthesis Example 6] (Synthesis of Compounds C to M) Compound C was synthesized in the same manner as Compound A except that the polyhydroxy compound and the capping agent shown in Table 1 were used.
~ M were synthesized.

[Synthesis Example 7] (Synthesis of etherified hydroxy compound a) Compound (17) as a polyhydroxy compound
0 g and 49.0 g of a 13% aqueous potassium hydroxide solution were placed in a flask, and 9.6 g of dimethyl sulfuric acid was added dropwise over 30 minutes while controlling the temperature at 20 to 40 ° C.
The reaction was carried out at 5 ° C. for 4 hours. After the reaction, 3
6% hydrochloric acid was added dropwise to adjust the pH of the system to 1-2, and then 1
0% aqueous sodium hydrogen carbonate solution is added dropwise to adjust the pH in the system.
Was 7-8. Add 120 g of diethyl ether,
Extracted and then washed 5 times with 50 g of ion exchanged water.
The solution was concentrated by distillation and removed, and further dried under vacuum to remove the etherified hydroxy compound (compound a).
2.7 g were obtained. Compound A is a solution of acetone -d _6, ¹
H-NMR measurement was performed. The ratio of etherification was calculated from the area ratio between the proton signal of the unreacted hydroxyl group and the methyl proton signal of the methyl ether group, and as a result, it was 65%.

[Synthesis Example 8] (Synthesis of Etherified Hydroxy Compounds b and c) Same as Compound a in Synthesis Example 7 except that a polyhydroxy compound and an etherifying agent shown in Table 3 were used and the charging ratio was changed. Compounds b and c were synthesized according to a simple synthesis method. Table 3 shows the results of measuring the etherification rate by ¹ H-NMR measurement.

[Synthesis Example 9] (Synthesis of etherified hydroxy compound d) Compound (17) as a polyhydroxy compound
0 g, 17.0 g of benzyl chloride, 22.4 g of anhydrous potassium carbonate, and 90 g of dimethylformamide were placed in a flask, dissolved, and kept at 60 ° C. for 4 hours to carry out a reaction. After completion of the reaction, 36% hydrochloric acid was added dropwise to adjust the pH in the system to 2-3, and then a 10% aqueous sodium hydrogen carbonate solution was added dropwise to adjust the pH in the system to 7-8. After the precipitate was filtered off, the precipitate was dissolved in 260 g of diethyl ether,
Washing was performed 5 times with 0 g of ion-exchanged water. The solution was concentrated by distilled off, further subjected to vacuum drying, ¹ H-N
An MR measurement was performed. The ratio of etherification was calculated from the area ratio between the proton signal of the unreacted hydroxyl group and the methylene proton signal of the benzyl ether group, and as a result, it was 78%.

[Synthesis Example 10] (Synthesis of etherified hydroxy compounds e to h) The same as compound d in Synthesis Example 9 except that a polyhydroxy compound and an etherifying agent shown in Table 3 were used and the charging ratio was changed. Compounds e to h according to various synthetic methods
Was synthesized. Table 3 shows the results of measuring the etherification rate by ¹ H-NMR measurement.

[Synthesis Example 11] (Synthesis of Etherified Hydroxy Compounds i to m) The compounds in Synthesis Example 7 were used except that the polyhydroxy compounds shown in Table 3 and dimethyl sulfate were used as etherification agents, and the charging ratios were changed. Compounds im were synthesized according to the same synthesis method as in a. Table 1 shows the results of measuring the etherification rate by ¹ H-NMR measurement.

Example 1 100 parts of the novolak resin obtained in Synthesis Example 1, 25 parts of the photosensitive agent obtained in Synthesis Example 3, and Compound A were mixed with ethyl lactate 350
The resulting solution was dissolved in the solution and filtered through a 0.1 μm Teflon filter (polytetrafluoroethylene filter) to prepare a resist solution. The resist solution was applied on a silicon wafer by a coater, and prebaked at 90 ° C. for 90 seconds to form a resist film having a film thickness of 1.17 μm. This wafer is used as a g-line stepper NSR1505G6E
(Nikon Corporation, NA = 0.54) and a test reticle while performing exposure while varying the exposure time.
Post exposure bake (Post Expos) at 10 ° C. for 60 seconds
ure Banking). Next, 2.38%
23 in aqueous tetramethylammonium hydroxide solution
Developing by paddle method at 1 ° C. for 1 minute to form a positive pattern. Take out this wafer, observe it with an electron microscope,
Pattern formation, pattern dimensions were measured, and resist evaluation was performed. Table 2 shows the results.

Examples 2 to 12 A resist solution was prepared in the same manner as in Example 1 except that Compounds C to M were used instead of Compound A, respectively.
An evaluation was performed. Table 2 shows the results.

Example 13 100 parts of the novolak resin obtained in Synthesis Example 1, 25 parts of the photosensitizer obtained in Synthesis Example 3, 1.25 parts of Compound B and 3.75 parts of the above polyhydroxy compound (17) were lactic acid. Ethyl 35
0 part, and filtered through a 0.1 μm Teflon filter to prepare a resist solution. This resist solution was evaluated in the same manner as in Example 1. Table 2 shows the results.

Comparative Example 1 Instead of the photosensitizer A, the polyhydroxy compound (1
A resist solution was prepared and evaluated in the same manner as in Example 1 except that 7) was used. Table 2 shows the results.

Comparative Example 2 A resist solution was prepared and evaluated in the same manner as in Example 1 except that Compound A was not used. Table 2 shows the results.

[0077]

[Table 1]

[0078]

[Table 2]

Example 14 100 parts of the novolak resin obtained in Synthesis Example 2, 25 parts of the photosensitizer obtained in Synthesis Example 3, and 5 parts of Compound a were obtained by mixing ethyl lactate 35
0 part, and filtered through a 0.1 μm polytetrafluoroethylene filter to prepare a resist solution. After applying the resist solution on a silicon wafer with a coater, pre-baking was performed at 90 ° C. for 90 seconds to obtain a film thickness of 1.
A 17 μm resist film was formed. This wafer was treated with a g-line stepper NSR1505G6E (manufactured by Nikon Corporation, NA =
0.54) and exposure using a test reticle while varying the exposure time, and then baking after exposure at 110 ° C. for 60 seconds (Post Exposure Bank).
g) was performed. Next, a positive pattern was formed by developing with a 2.38% aqueous solution of tetramethylammonium hydroxide by a paddle method at 23 ° C. for 1 minute. The wafer was taken out and observed with an electron microscope, pattern formation and pattern dimensions were measured, and the resist was evaluated. Table 4 shows the results.

Examples 15 to 25 A resist solution was prepared and evaluated in the same manner as in Example 14 except that compounds c to m were used instead of compound a. Table 4 shows the results.

Example 26 100 parts of the novolak resin obtained in Synthesis Example 2, 25 parts of the photosensitizer obtained in Synthesis Example 3, 3 parts of compound b, and 2 parts of the above polyhydroxy compound (17) were mixed with 350 parts of ethyl lactate. The solution was dissolved in the solution and filtered through a 0.1 μm polytetrafluoroethylene filter to prepare a resist solution. With respect to this resist solution, a resist evaluation was performed in the same manner as in Example 14. Table 4 shows the results.

Comparative Example 3 Instead of the photosensitizer a, the above-mentioned polyhydroxy compound (1
A resist solution was prepared and evaluated in the same manner as in Example 14 except that 7) was used. Table 4 shows the results.

Comparative Example 4 A resist solution was prepared and evaluated in the same manner as in Example 14 except that Compound a was not used. Table 4 shows the results.

[0084]

[Table 3]

[0085]

[Table 4]

[0086]

According to the present invention, it is possible to provide a positive resist composition which is particularly excellent in exposure latitude and excellent in sensitivity, residual film ratio, resolution and dimensional control. The positive resist of the present invention is particularly suitable for fine processing of 1 μm or less.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor: Tetsuro Kusunoki 1-2-1 Yoko, Kawasaki-ku, Kawasaki-shi, Kanagawa Japan Zeon Corporation Research and Development Center (72) Inventor: Mikifumi Kashiwagi Kawasaki, Kanagawa Prefecture (2-1) Inventor Hiroshi Yagi 1-2-1, Yoko, Kawasaki-ku, Kawasaki-shi, Kanagawa Pref. Japan Research and Development Center (72) Invention Person Kazuko Koito Inside the Research and Development Center, 1-1-2 Yoko, Kawasaki-ku, Kawasaki-ku, Kanagawa Prefecture (72) Inventor Shinya Shinya Ikeda 2-1-1, Yaikou, Kawasaki-ku, Kawasaki-shi, Kanagawa Japan Research and Development Center (56) References JP-A-64-44439 (JP, A) JP-A 1-177032 (JP, A) JP-A-2-10350 (JP, A) JP-A-3-28849 (JP, A) JP-A-3-179353 (JP, A) JP-A-3-259149 (JP, A) JP-A-3-273251 (JP) JP-A-3-279958 (JP, A) JP-A-3-296757 (JP, A) JP-A-4-50851 (JP, A) JP-A-4-86665 (JP, A) JP-A-4-174438 (JP, A) JP-A-4-271349 (JP, A) JP-A-4-274242 (JP, A) JP-A-4-296755 (JP, A) JP-A-4-122938 (JP, A A)

Claims (2)

(57) [Claims] (A) an alkali-soluble phenolic resin 1
00 parts by weight, (b) quinonediazidesulfonic acid ester
1 to 100 parts by weight of a photosensitizer, (c) the following general formula [I] to
A small amount selected from the group consisting of compounds represented by [VI]
Hydroxyl group (-OH) of at least one polyhydroxy compound
Of the sulfonic acid esterification (-OS
O_TwoR), carboxylic esterification (-OCOR), and
And etherification (-OR).
At least one conversion reaction(Wherein R is an alkyl group, substituted
Alkyl, alkenyl, substituted alkenyl, aryl
Group, substituted aryl group, arylalkyl group, or
A substituted arylalkyl group. )Compounds modified by
Stuff(However, this compound is
Only one hydroxyl group at a specific position is modified by the above conversion reaction
Excluding the case of a compound having the specified structure alone. )1 to 10
0 parts by weight, and (d) an amount sufficient to dissolve the components
A positive resist composition containing a solvent. General formula [I](R¹~ R^Four: Hydrogen, halogen, hydroxyl group, C₁~ C_FourAl
Kill group and C_Two~ C_FiveFrom the alkenyl group of
Is selected. R^Five~ R⁶: Hydrogen, halogen and C₁~ C_FourAlkyl group
Are selected independently from each other. R⁷~ R^Ten: Hydrogen and C₁~ C_FourFrom the alkyl group of
Each is independently selected. ) General formula [II](R¹~R ⁶ : Hydrogen, halogen, C ₁ ~ C_FourAn alkyl group of
C_Two~ C_FiveAn alkenyl group of C₁~ C₆Alkoxy group and
And substituted alkoxy groups are each independently selected.R ⁷ : Hydrogen, halogen, hydroxyl group, C ₁ ~ C _Four The alkyl of
Group, C _Two ~ C _Five An alkenyl group of C ₁ ~ C ₆ An alkoxy group
Or a substituted alkoxy group.  R⁸: Hydrogen or C₁~ C_FourIs an alkyl group. ) General
Formula [III](R¹~ R⁶: Hydrogen, halogen, C₁~ C_FourAlkyl group
And C_Two~ C_FiveIndependently selected from the alkenyl groups of
Is done. R⁷~ R⁸: Hydrogen, halogen and C₁~ C_FourAlkyl group
Are selected independently from each other. R⁹~ R¹¹: Hydrogen and C₁~ C_FourFrom the alkyl group of
Each is independently selected. ) General formula [IV](A: -S-, -O-, -CO-, -COO-, -SO
-, -SO_Two-Or -CR⁷R⁸-. Where R⁷
~ R⁸Is hydrogen, C₁~ C_FourAn alkyl group of C_Two~ C_FiveNo
Independently selected from lucenyl and phenyl groups
Is done. R¹~ R^Five: Hydrogen, halogen, hydroxyl group, C₁~ C_FourArchi
Group, C_Two~ C_FiveAn alkenyl group of C₁~ C₆The alkoxy of
From the group represented by the general formula (IV-1)
Each independently selected and at least one of them3One
It is a group represented by the general formula (IV-1). ) General formula
(IV-1)(R⁶: Hydrogen, halogen, C₁~ C_FourAn alkyl group or
C_Two~ C_FiveAlkenyl group. n is 0, 1 or 2
is there. ) General formula [V](A: alkylene group, substituted alkylene group, alkenylene
Or a substituted alkenylene group. R¹~ R⁶: Hydrogen, halogen, C ₁ ~ C_FourThe alkyl ofGroupAnd
And C₁~ C_FourEach independently selected from
It is. ) General formula [VI](R¹~ R⁶: Hydrogen, halogen, C₁~ C_FourAlkyl group
And C_Two~ C_FiveIndependently selected from the alkenyl groups of
Is done. R⁷~ R⁸: Hydrogen, halogen and C₁~ C_FourAlkyl group
Are selected independently from each other. R⁹~ R¹⁴: Hydrogen and C₁~ C₆From the alkyl group of
Each is independently selected. ) 2. The compound (c) having a wavelength of 300 to 50.
2. The positive resist composition according to claim 1, wherein the composition does not cause a change in solubility in an aqueous alkaline solution upon exposure to ultraviolet light of 0 nm.