JP2002251014A - Chemical amplification type resist composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chemical amplification type resist composition excellent in transmittance to light of <=170 nm wavelength and suitable particularly for F2 excimer laser lithography. SOLUTION: The chemical amplification type resist composition contains a radiation sensitive acid generating agent which generates an acid when exposed with radiation of <=170 nm and a binder resin which is alkali-soluble or undergoes a chemical change by the action of the radiation sensitive acid generating agent after irradiation with radiation and becomes alkali-soluble and has a polymerization unit in which a linking group is an ether bond.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a chemically amplified 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 a semiconductor.
In lithography, as represented by the Rayleigh diffraction limit equation, in principle, the shorter the exposure wavelength, the higher the resolution can be increased. The exposure light source for lithography used in the manufacture of semiconductors has a wavelength of 436 nm.
Line, wavelength 365nm of i-line, KrF excimer laser having a wavelength of 248 nm, have become ArF excimer laser and yearly short wavelength of 193 nm, is further F ₂ excimer laser promising wavelengths 157nm as a next generation exposure light source I have. For KrF excimer laser exposure and ArF excimer laser exposure, a so-called chemically amplified resist utilizing the catalytic action of an acid generated by exposure is widely used because of its excellent sensitivity. Also, there is a high possibility that a chemically amplified resist is used for F ₂ excimer laser exposure in terms of sensitivity.

As a resist for KrF excimer laser exposure, a polyvinylphenol-based binder resin has been used. On the other hand, the binder resin used for the resist for ArF excimer laser exposure does not have an aromatic ring in order to secure the transmittance of the resist, and has an alicyclic ring instead of the aromatic ring in order to have dry etching resistance. It is known that what has is good. Such alicyclic resins include DC Hofer, Journal of Photopolym
er Science and Technology, Vol.9, No.3, 387-398 (1
996) are known.
Also, S. Takechi et al, Journal of Photopolymer Sc
ience and Technology, Vol.9, No.3, 475-487 (1996)
And Japanese Patent Application Laid-Open No. 9-73173 discloses that when a polymer or copolymer of 2-methyl-2-adamantyl methacrylate is used as a resin for a chemically amplified resist,
-It has been reported that adamantyl is cleaved by the action of an acid to act positively, and that high dry etching resistance, high resolution and good adhesion to a substrate are obtained.

[0004]

However, binder resins used in conventional resists for KrF excimer laser exposure and ArF excimer laser exposure are:
Light having a wavelength of 170 nm or less, for example, F _{2 having} a wavelength of 157 nm
It did not show sufficient transmittance for the excimer laser. If the transmittance is low, it adversely affects various resist properties such as profile, contrast, and sensitivity.

Accordingly, an object of the present invention is to provide a resist composition which has excellent transmittance for light having a wavelength of 170 nm or less and is particularly suitable for F ₂ excimer laser lithography. The present inventors have found that by using a resin having a specific polymerization unit as a binder resin constituting a resist composition, it is possible to improve the transmittance at a wavelength of, for example, an F ₂ excimer laser of 157 nm, and the present invention. completed.

[0006]

Means for Solving the Problems That is, according to the present invention, there are provided:
A radiation-sensitive acid generator that generates an acid by exposure to radiation of 0 nm or less and an alkali-soluble agent which is itself alkali-soluble or undergoes a chemical change due to the action of the radiation-sensitive acid generator after irradiation with an alkali-soluble acid And a binder resin having a polymerized unit in which a linking group is an ether bond. The present invention provides a chemically amplified resist composition characterized by comprising:

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The present invention is a binder resin which is alkali-soluble by itself or undergoes a chemical change by the action of a radiation-sensitive acid generator described below after irradiation, and becomes alkali-soluble, wherein the linking group is an ether bond. It is characterized by using a resin having a certain polymerization unit.

Here, typical examples of the polymerized unit in which the linking group is an ether bond include, for example, the following formulas (I), (II) and (III) (Wherein, R ₁ represents a hydroxyl group which may be protected by an acid leaving group, and R _{2 to} R ₄ each independently represent a hydroxyl group, a hydrogen atom and a halogen atom which may be substituted by an acid leaving group. , An alkyl group or a cycloalkyl group, and R ₅ represents a hydrogen atom or an alkyl group which may be substituted with a halogen.
r represents 0 or 1. A represents an alkylene group, an alkylidene group, an oxygen atom, a sulfur atom, or SO ₂ . ) And the like. Two or more of these may be present.

The acid leaving group in the hydroxyl group which may be protected by an acid leaving group includes, for example, tert-butyl, tert-butyl,
Groups in which a quaternary carbon is bonded to an oxygen atom, such as -butoxycarbonyl and tert-butoxycarbonylmethyl; tetrahydro-2-pyranyl, tetrahydro-2-furyl, 1
-Ethoxyethyl, 1- (2-methylpropoxy) ethyl, 1- (2-methoxyethoxy) ethyl, 1- (2-
Acetoxyethoxy) ethyl, 1- [2- (1-adamantyloxy) ethoxy] ethyl and 1- [2- (1-
Acetal-type groups such as adamantanecarbonyloxy) ethoxy] ethyl and the like can be mentioned.

Examples of the halogen atom include fluorine, chlorine, bromine and the like, and examples of the alkyl group include methyl, ethyl, propyl and i-propyl. Examples of the cycloalkyl group include cyclopentyl, cyclohexyl and the like. The alkyl group which may be substituted by halogen, for example _{-CH 2 - (CF 2) 3} -CF 3, -
CH _2- (CF ₂ ) ₅ -CF ₃ , -CH _2- (CF ₂ ) ₇ -CF ₃ , -CH _2- (CF ₂ )
₉ -CF ₃ , -CH _2- (CF ₂ ) ₂ -CF (CF ₃ ) ₂ , -CH _2- (CF ₂ ) ₄ -CF
_{(CF 3) 2, -CH 2} - (CF 2) 6 -CF (CF 3) 2, -CH 2 -O-CH2-CF
_{2 -CF 2 H, -CH 2 -O} -CH2- (CF 2) 3 -CF 2 H, -CH 2 -O-CH
_{2- (CF 2) 5 -CF 2} H, -CH 2 -O-CH2- (CF 2) 7 -CF 2 H, and the like. Examples of the alkylene group include methylene and the like, and examples of the alkylidene group include propylidene and pentafluoropropylidene.

The binder resin in the present invention has the above-mentioned polymerized unit in which the linking group is an ether bond. The binder resin itself is alkali-soluble, or is exposed to the action of a radiation-sensitive acid generator after irradiation. The property of being alkali-soluble due to a chemical change is generally required for an alkali-developed type chemically amplified resist, and therefore, by applying a conventionally known technique for the chemically amplified resist, Such properties can be imparted.

The binder resin itself is alkali-soluble, or becomes alkali-soluble by the action of a radiation-sensitive acid generator after irradiation, and the irradiated portion of the resist film containing the binder resin is alkali-developed. In the case of being removed by, a positive resist is obtained.
That is, in a chemically amplified positive resist, an acid or a base generated from a radiation-sensitive acid generator in a radiation irradiation part is diffused by a subsequent heat treatment (post exposure bake),
The radiation-irradiated part is alkali-solubilized by cleaving the protective group of the resin or the like and regenerating the acid or base. The chemically amplified positive resist has a binder resin which is alkali-soluble and, in addition to the binder resin and the radiation-sensitive acid generator, has a protecting group which can be cleaved by the action of an acid or a base. It has a dissolution inhibiting ability for an alkali-soluble binder resin, but contains a dissolution inhibitor which becomes alkali-soluble after the protective group is cleaved by the action of an acid or a base, and the action of an acid or a base when the binder resin is an acid or a base. And a protecting group which is insoluble or poorly soluble in alkali, but becomes soluble in alkali after the protecting group is cleaved by the action of an acid or a base.

On the other hand, when the binder resin is alkali-soluble and the radiation-irradiated portion of the resist film containing the binder resin is hardened and the portion not irradiated with the radiation is removed by alkali development, a negative resist is obtained. . That is, a chemically amplified negative resist usually has a binder resin which is alkali-soluble, contains a crosslinking agent in addition to the binder resin and a radiation-sensitive component, and generates an acid generated from a radiation-sensitive acid generator in a radiation irradiation section. Alternatively, the base is diffused by a subsequent heat exposure (post exposure bake), and acts on the crosslinking agent to cure the binder resin in the radiation-irradiated portion and to render it insoluble in alkali.

The alkali-soluble site in the binder resin used in the present invention may be, for example, a unit having an aromatic ring or a unit having a bisphenol skeleton.
Specific examples include a phenol unit and a bisphenol unit. The presence of a relatively large number of such alkali-soluble units makes the resin itself alkali-soluble. Of course, together with these units, alkali-insoluble units may be present, for example, a resin having a mixed unit in which a part of the hydroxyl group of a phenol unit or a bisphenol unit is alkyl-etherified, phenol or bisphenol and another polymer. A resin having a mixed unit obtained by an addition reaction with a reactive ether can be a resin which is itself alkali-soluble as defined in the present invention as long as it is alkali-soluble as a whole.

On the other hand, when a resin which is insoluble or hardly soluble in alkali but becomes alkali-soluble by the action of a radiation-sensitive acid generator after irradiation is used as a binder, the site having such properties is For example, an alkali-soluble unit such as a unit having a phenol skeleton exemplified above, in which a protecting group which has a dissolution inhibiting ability in an alkali developing solution but can be cleaved by the action of an acid or a base is introduced. It is possible. The group which has the ability to inhibit dissolution in an alkali developer but is unstable to an acid or a base can be any of various known protecting groups.

Groups which have the ability to inhibit dissolution in an alkaline developer but are unstable to acids include, for example, tert-
Groups in which a quaternary carbon is bonded to an oxygen atom, such as butyl, tert-butoxycarbonyl and tert-butoxycarbonylmethyl; tetrahydro-2-pyranyl, tetrahydro-2
-Furyl, 1-ethoxyethyl, 1- (2-methylpropoxy) ethyl, 1- (2-methoxyethoxy) ethyl, 1- (2-acetoxyethoxy) ethyl, 1- [2
-(1-adamantyloxy) ethoxy] ethyl and 1
Acetal-type groups such as-[2- (1-adamantanecarbonyloxy) ethoxy] ethyl;
These groups will replace the hydrogens of the phenolic hydroxyl groups. These protecting groups can be obtained by subjecting an alkali-soluble resin having a phenolic hydroxyl group to a known protecting group introduction reaction, or by copolymerizing a compound having a phenol skeleton having such a group as one monomer. Can be introduced into the resin.

In the present invention, in the binder resin, the above formula
In the units represented by the formulas (I) to (III), except for those having a polymerizable unit having an alkali-soluble group in the units represented by (III) or a group which undergoes a chemical change by the action of a radiation-sensitive compound after irradiation to become alkali-soluble. ) To (III), in addition to the polymerized unit having an alkali-soluble group as described above or a polymerized unit having a group which undergoes a chemical change by the action of a radiation-sensitive compound after irradiation to become alkali-soluble. Will exist. In that case,
This resin has a compound represented by the formula (I) to (III) as one polymerization unit and has an alkali-soluble group, or a group which becomes alkali-soluble by a chemical change caused by the action of a radiation-sensitive compound after irradiation. Is produced by copolymerization using a compound having the following as another polymerization unit.
The copolymerization itself can be carried out according to a conventional method. For example, the monomers may be dissolved in an appropriate solvent, oxygen or air may act in the presence of a catalyst to initiate the polymerization, and the reaction may proceed.

By incorporating at least one polymerized unit selected from the formulas (I) to (III) into a binder resin, this resin can transmit light having a wavelength of 170 nm or less, for example, an F ₂ excimer laser having a wavelength of 157 nm. The rate is excellent. Accordingly, the polymerized units represented by the formulas (I) to (III) can achieve such a performance and the resin itself is alkali-soluble, or alkali-soluble by the action of the radiation-sensitive compound after irradiation. It only has to exist. In general, the ratio of the polymerization units of the formulas (I) to (III) may be appropriately selected from the range of about 10 to 100 mol% of the whole resin, though it depends on the type and type of the resist.

The presence of a relatively large number of alkali-soluble units makes the resin itself alkali-soluble. A binder resin that is itself alkali-soluble can be used as a positive resist in combination with a dissolution inhibitor and a radiation-sensitive compound, and can be a negative resist in combination with a crosslinking agent and a radiation-sensitive compound. .

The dissolution inhibitor used when the alkali-soluble resin itself is used as a binder to form a positive resist is capable of inhibiting the phenolic hydroxyl group of a phenolic compound from dissolving in an alkali developing solution. It may be a compound protected by a group that is cleaved by the action of a base.
Examples of the group that is cleaved by the action of an acid include a tert-butoxycarbonyl group and tetrahydro-2-pyranyl, which are substituted with hydrogen of a phenolic hydroxyl group. Dissolution inhibitors having a group that is cleaved by the action of an acid include, for example, 2,2-bis (4-tert-butoxycarbonyloxyphenyl) propane, bis (4-tert-
Butoxycarbonyloxyphenyl) sulfone, 3,5
-Bis (4-tert-butoxycarbonyloxyphenyl) -1,1,3-trimethylindane and the like. On the other hand, examples of the group that is cleaved by the action of a base include an alkyl carbamate or a cycloalkyl carbamate group, and a compound in which a phenolic hydroxyl group is replaced with an alkylcarbamoyloxy group or a cycloalkylcarbamoyloxy group is a compound of the base. It can be a dissolution inhibitor having a group that is cleaved by action. When such a dissolution inhibitor is used, it is convenient to include it in the binder component together with the binder resin.

The crosslinking agent used when the alkali-soluble resin itself is used as a binder and a negative resist is used,
Any material can be used as long as the binder resin is crosslinked by the action of an acid or a base. In general, the crosslinking agent often causes a crosslinking reaction by the action of an acid. Usually, a compound having a methylol group or an alkyl ether thereof is used. Specific examples include hexamethylolmelamine,
Pentamethylolmelamine, tetramethylolmelamine, hexamethoxymethylmelamine, methylolated melamine such as pentamethoxymethylmelamine and tetramethoxymethylmelamine or an alkyl ether thereof,
Methylolated benzoguanamine such as tetramethylol benzoguanamine, tetramethoxymethyl benzoguanamine and trimethoxymethyl benzoguanamine or an alkyl ether thereof, 2,6-bis (hydroxymethyl) -4-methylphenol or an alkyl ether thereof, 4-tert-butyl -2,6-bis (hydroxymethyl) phenol or an alkyl ether thereof, 5-ethyl-1,3-bis (hydroxymethyl) perhydro-
1,3,5-triazin-2-one (commonly known as N-ethyldimethyloltriazone) or an alkyl ether thereof,
N, N-dimethylol urea or its dialkyl ether, 3,5-bis (hydroxymethyl) perhydro-
1,3,5-oxadiazin-4-one (commonly called dimethyloluron) or an alkyl ether thereof, tetramethylol glyoxal diurein or a tetramethyl ether thereof.

On the other hand, a unit that undergoes a chemical change by the action of the radiation-sensitive compound after irradiation and becomes alkali-soluble, and a binder resin having a polymerized unit selected from the formulas (I) to (III) are: In combination, a positive resist can be obtained.

Typical examples of the binder resin having a polymerized unit in which the linking group is an ether bond include, for example, the following formulas (Ia), (IIa) and (IIIa) (Wherein, R _{1 to} R ₅ , r and A represent the same meaning as described above). It may be a mixture of two or more of these.

Specific examples of such a high molecular compound include, for example, the following compounds.

[0025] In the above formula, R ₆ is a protecting group for a hydroxyl group, R ₇
Represents a methyl group or a trifluoromethyl group, and R ₈ represents a protecting group for hydrogen or a hydroxyl group. The hydroxyl-protecting group referred to herein may be the above-described alkyl, or any of the various groups exemplified as groups that are cleaved by the action of an acid or alkali. Such a polymer compound is, for example, Polym.Mater.Sci.
Eng. 81 , 35 (1999), PolymerPreprints 41 (1), 365 (200
0), and can be produced according to the method described in JP-A-2000-28979.

As described above, the chemically amplified resist using an alkali-soluble or alkali-soluble resin as a binder contains a radiation-sensitive compound which is decomposed by the action of radiation. When the binder resin is alkali-soluble, using a compound having a group that can be cleaved by the action of an acid as a dissolution inhibitor, in the case of acting positively, or having a group in which the binder resin is cleaved by the action of an acid, Although it is insoluble or hardly soluble in alkali, it becomes alkali-soluble after the group that is cleaved by the action of an acid is cleaved. An acid generator that generates an acid by the action of is used. Further, in the case of a negative resist containing a binder resin which is alkali-soluble and contains a cross-linking agent, the cross-linking agent often causes a cross-linking reaction by the action of an acid. An acid generator is used. On the other hand, when the binder resin is alkali-soluble, using a compound having a group that can be cleaved by the action of a base as a dissolution inhibitor,
When the binder resin has a group that is cleaved by the action of a base and acts positively, a base generator that generates a base by the action of radiation is used as the radiation-sensitive compound.

The acid generator as the radiation-sensitive compound can be any of various compounds that generate an acid by irradiating the substance itself or a resist composition containing the substance with radiation. For example, onium salts, halogenated alkyl triazine compounds, disulfone compounds,
Examples thereof include a compound having a diazomethanesulfonyl skeleton and a sulfonic acid ester-based compound. Specific examples of such an acid generator are shown below.

Onium salts: 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 trifluoromethanesulfo Over DOO, 4-methoxyphenyl diphenyl sulfonium hexafluoroantimonate, 4-methoxyphenyl diphenyl sulfonium trifluoromethanesulfonate, p- tolyl diphenyl sulfonium trifluoromethanesulfonate, 2,4,6-trimethylphenyl diphenylsulfonium trifluoromethanesulfonate, 4-
tert-butylphenyldiphenylsulfonium trifluoromethanesulfonate, 4-phenylthiophenyldiphenylsulfonium hexafluorophosphate, 4-phenylthiophenyldiphenylsulfonium hexafluoroantimonate, 1- (2-naphthoylmethyl) thiolanium hexafluoroantimonate, 1- (2-naphthoylmethyl) thiolanium trifluoromethanesulfonate, 4-hydroxy-1-
Naphthyldimethylsulfonium hexafluoroantimonate, 4-hydroxy-1-naphthyldimethylsulfonium trifluoromethanesulfonate and the like.

Halogenated alkyl triazine compound:
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 and the like.

Disulfone compounds: diphenyl disulfone, di-p-tolyl disulfone, phenyl p-tolyl disulfone, phenyl p-methoxyphenyl
Disulfone and the like.

Compounds having a diazomethanesulfonyl skeleton: bis (phenylsulfonyl) diazomethane, bis (4-chlorophenylsulfonyl) diazomethane, bis (p-tolylsulfonyl) diazomethane, bis (4-te
rt-butylphenylsulfonyl) diazomethane, bis (2,4-xylylsulfonyl) diazomethane, bis (cyclohexylsulfonyl) diazomethane, (benzoyl) (phenylsulfonyl) diazomethane and the like.

Sulfonate compounds: 1-benzoyl-1-phenylmethyl p-toluenesulfonate (commonly called benzoin tosylate), 2-benzoyl-2-
Hydroxy-2-phenylethyl p-toluenesulfonate (commonly called α-methylol benzoin tosylate),
1,2,3-benzenetriyl trismethanesulfonate, 2,6-dinitrobenzyl p-toluenesulfonate, 2-nitrobenzyl p-toluenesulfonate, 4-nitrobenzyl p-toluenesulfonate,
N- (phenylsulfonyloxy) succinimide, N
-(Trifluoromethylsulfonyloxy) succinimide, N- (butylsulfonyloxy) succinimide, N- (10-camphorsulfonyloxy) succinimide, N- (trifluoromethylsulfonyloxy) phthalimide, N- (trifluoromethylsulfonyloxy) -5-norbornene-2,3-dicarboximide, N- (trifluoromethylsulfonyloxy)
Naphthalimide, N- (10-camphorsulfonyloxy) naphthalimide, α- (4-tosyloxyimino)-
4-methoxybenzyl cyanide and the like.

The base generator as a radiation-sensitive compound may also be added to the substance itself or to a resist composition containing the substance.
Various compounds capable of generating a base upon irradiation with radiation can be used. As a specific example, 2-
Nitrobenzyl cyclohexyl carbamate, 2,6
-Dinitrobenzyl cyclohexyl carbamate, formanilide, triphenylsulfonium hydroxide and the like. These compounds decompose under the action of radiation to produce amines and hydroxyl anions.

In general, in a chemically amplified resist composition using an acid generator, a basic compound, particularly a basic nitrogen-containing organic compound, for example, an amine is added as a quencher to thereby provide a resist after irradiation. It is known that the performance deterioration due to the deactivation of the acid accompanying the storage can be improved. In the present invention, when an acid generator is used as the radiation-sensitive compound, it is preferable to mix such a basic compound. Specific examples of the basic compound used for the quencher include those represented by the following formulas.

[0035]

In the formula, R ¹¹ and R ¹² independently represent hydrogen, alkyl, cycloalkyl or aryl which may be substituted by a hydroxyl group; R ¹³ , R ¹⁴ and R ¹⁵ independently represent hydrogen, It represents alkyl, cycloalkyl, aryl or alkoxy optionally substituted with a hydroxyl group, and R ¹⁶ represents alkyl or cycloalkyl optionally substituted with a hydroxyl group. m represents 0 or 1, and A represents alkyl, alkylene, carbonyl, imino, disulfide, sulfide or a secondary amine. Alkoxy represented by alkyl and R ¹³ to R ¹⁵ represented by R ¹¹ to R ¹⁶ may be respectively of the order of 1 to 6 carbon atoms, R ¹¹
Cycloalkyl represented by to R ¹⁶ may be a number about 5 to 10 carbon atoms, and the aryl represented by R ¹¹ to R ¹⁵ may be a number of about 6 to 10 carbon atoms. Further, the alkylene represented by A can have about 1 to 6 carbon atoms, and may be linear or branched.

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

The resist composition of the present invention contains the binder component in the range of about 60 to 99.9% by weight and the radiation-sensitive compound in the range of about 0.1 to 20% by weight based on the total solid content. Is preferred. A positive resist,
When a dissolution inhibitor is used, the number of the binder components is 5 to 4 based on the total solid content of the resist composition.
It is appropriate to contain it in the range of about 0% by weight. In the case of a negative resist, it is appropriate to contain a crosslinking agent in the range of about 1 to 30% by weight based on the total solid content of the resist composition. When the binder resin is alkali-soluble by the action of the radiation-sensitive compound after irradiation, acts positively, and when the majority of the resist composition is occupied by the binder resin and the radiation-sensitive compound,
It is appropriate that the amount of the binder resin is about 80% by weight or more based on the total solid content in the composition.
When the radiation-sensitive compound is an acid generator and a basic compound is used as the quencher, it is contained in an amount of about 0.01 to 1% by weight based on the total solid weight of the resist composition. Is preferred. This composition also comprises
If necessary, various additives such as sensitizers, other resins, surfactants, stabilizers and dyes can be contained in small amounts.

The resist composition of the present invention usually becomes a resist solution in a state where each of the above components is dissolved in a solvent, and is applied to a substrate such as a silicon wafer by a conventional method such as spin coating. The solvent used here may be any as long as it dissolves each component, has an appropriate drying rate, and gives a uniform and smooth coating film after the solvent evaporates. A solvent generally used in this field is used. Can. For example,
Glycol ether esters such as ethyl cellosolve acetate, methyl cellosolve acetate and propylene glycol monomethyl ether acetate, ethers such as diethylene glycol dimethyl ether,
Esters such as ethyl lactate, butyl acetate, amyl acetate and ethyl pyruvate; ketones such as acetone, methyl isobutyl ketone, 2-heptanone and cyclohexanone; and cyclic esters such as γ-butyrolactone. . These solvents can be used alone or in combination of two or more.

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

[0041]

Next, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. Parts in the examples are by weight unless otherwise specified. The weight average molecular weight is a value determined by gel permeation chromatography using polystyrene as a standard.

Example of Monomer Synthesis (Synthesis of 2- (tetrahydropyran-2-yl) oxy-6-methylphenol) 13.91 g of 3-methylcatechol and 4.71 g of 3,4-dihydro-2H-pyran were charged, and 13 .91 g of ethyl acetate was added to form a solution. After cooling in an ice bath, 0.070 g of pyridinium p-toluenesulfonate was added and stirred for 1 hour. Thereafter, 9.34 g of 3,4-dihydro-
2H-pyran, 0.070 g of pyridinium p-toluenesulfonate, and 4.71 g of ethyl acetate were added, and the mixture was returned to room temperature and stirred for 3 hours. Further, 2.36 g of 3,4-dihydro-2H-pyran was added and stirred for 2 hours. After adding 49.17 g of ethyl acetate, the mixture was washed 5 times with water, and the organic phase was dried over magnesium sulfate (anhydrous) and concentrated. The obtained oily substance was purified by a silica gel column,
4.36 g of 2- (tetrahydropyran-2-yl) oxy-6-methylphenol were obtained.

[0043]

Resin Synthesis Example (A1) 0.21 g of cuprous chloride, 6.89 g of pyridine, and 35.26 g of toluene were added to a four-necked flask equipped with a magnetic stirrer, an air inlet tube, and a thermometer, and air was added. The mixture was vigorously stirred while being introduced. There, 4.37 g of 2- (tetrahydropyran-2-yl) oxy-6-methylphenol and 2,6
-2.57 g of dimethylphenol in 44.04 of toluene
The solution dissolved in g was added. Further, 5.97 g of sodium sulfate (anhydrous) was added, and the mixture was stirred at room temperature for 20 hours while introducing air. After the reaction, the mixture was poured into methanol, and the obtained crystals were filtered and dried to obtain 3.83 g of a resin. This resin was dissolved in 19.15 g of tetrahydrofuran, concentrated hydrochloric acid was added, and the mixture was stirred at room temperature for 20 hours. 1% after reaction
The resulting crystals were poured into hydrochloric acid, filtered and dried, and 2.3
0 g of the resin was obtained. Yield 44.6%. Weight average molecular weight 3
2551. This is called resin A1.

[0045]

Resin Synthesis Example (A2) 0.21 g of cuprous chloride, 6.89 g of pyridine and 35.51 g of toluene were added to a four-necked flask equipped with a magnetic stirrer, an air inlet tube, and a thermometer, and air was added. The mixture was vigorously stirred while being introduced. A solution of 8.81 g of 2- (tetrahydropyran-2-yl) oxy-6-methylphenol dissolved in 44.04 g of toluene was added thereto. Further, 6.01 g of sodium sulfate (anhydrous) was added, and the mixture was stirred at room temperature for 16 hours while introducing air. After the reaction, the resultant was poured into methanol, and the obtained crystals were filtered and dried to obtain 3.58 g of a resin. 17.60 g of this resin in tetrahydrofuran
, And concentrated hydrochloric acid was added. After stirring at room temperature for 20 hours, the temperature was raised to 60 ° C., and the mixture was stirred for 8 hours. After the reaction, the mixture was poured into 1% hydrochloric acid, and the obtained crystals were filtered, dried and 2.2 g.
Resin was obtained. Yield 41%. Weight average molecular weight 2070
4. This is called resin A2.

[0047]

Resin Synthesis Example (X1) 2-Methyl-2-adamantyl methacrylate and α-methacryloyloxy-γ-butyrolactone were charged at a molar ratio of 5: 5 (15.0 g: 11.7 g), and all monomers were mixed. A solution was added by adding 2 weight times methyl isobutyl ketone. Thereto, azobisisobutyronitrile as an initiator was added at 2 mol% based on the total amount of monomers, and the mixture was heated at 80 ° C. for about 8 hours. Thereafter, an operation of pouring the reaction solution into a large amount of heptane to precipitate was performed three times, and purification was performed. As a result, a copolymer having a weight average molecular weight of about 10,000 was obtained. This is resin X1
And

Resin X2: Poly (p-produced by Nippon Soda Co., Ltd.)
A resin in which the hydroxyl group of vinyl phenol) (product name "VP-2500") is protected with an isopropyl group with an average protection rate of 20%.

[0050]

Examples 1 to 3 and Comparative Example First, a solution obtained by dissolving a resin in a propylene glycol monomethyl ether acetate solvent was applied to a magnesium fluoride wafer so that the film thickness after drying was 0.1 μm, Prebake on a direct hot plate under the condition of 60 seconds,
A resist film was formed. The transmittance of the thus formed resist film at a wavelength of 157 nm was measured using the vacuum ultraviolet spectrometer (VUV-200 manufactured by JASCO) used above, and the results shown in Table 1 were obtained. A1 and A2 used were those synthesized above. For A3, BPX-55 (Adeka Polyether manufactured by Asahi Denka) was used. BPX-55 is a polymer as shown below.

[0052]

[0053]

Example 4 The following components were mixed and filtered through a fluororesin filter having a pore size of 0.2 μm to prepare a resist solution.

Resin (as solid content) 10 parts Crosslinking agent: hexamethoxymethylmelamine 0.5 parts Acid generator: N- (isopropylsulfonyloxy) succinimide 1.1 parts (Plus resin carry-in): 100 parts of propylene glycol monomethyl ether acetate

Silicone coated with "DUV-30J", an organic anti-reflective coating composition manufactured by Brewer, and baked at 215 ° C. for 60 seconds to form an organic anti-reflective coating having a thickness of 1600 ° The resist solution prepared above was applied to the wafer such that the film thickness after drying was 0.1 μm. Pre-bake is
The test was performed on a direct hot plate at 100 ° C. for 60 seconds. The wafer on which the resist film was formed was subjected to open frame exposure using a simple F ₂ excimer laser exposure machine [“VUVES-4500” obtained from Lithotec Japan Co., Ltd.] while changing the exposure amount stepwise.
After exposure, on a direct hot plate, 105 ° C
For 60 seconds, followed by paddle development with a 2.38% by weight aqueous solution of tetramethylammonium hydroxide for 60 seconds.
The wafer after development was visually observed to determine the minimum exposure amount at which the resist was removed (film removal sensitivity), and the results in Table 2 were obtained.

[0057]

[0058]

The resist composition of the present invention shows a high transmittance when exposed to light using a light source having a wavelength of 170 nm or less, for example, an F ₂ excimer laser having a wavelength of 157 nm.
Since it has sufficient patterning performance by exposure,
Excellent performance can be achieved as a chemically amplified resist using a light source with a wavelength of less than nm.

 ────────────────────────────────────────────────── ─── Continued from the front page (72) Yasunori Uetani 3-1-198 Kasuganaka, Konohana-ku, Osaka City F-term (reference) 2H025 AA01 AA03 AB16 AC04 AC08 AD01 AD03 BE00 BE10 BF29 CB21 CB41 CB45 CC17 FA17 4J002 CH011 CH061 CH081 EB106 EU036 EU186 EV226 EV236 EV246 EW046 EY016 EY026 GP03

Claims (6)

[Claims] 1. A radiation-sensitive acid generator that generates an acid upon exposure to radiation of 170 nm or less, and a chemical change caused by the action of the radiation-sensitive acid generator, which is itself alkali-soluble or after irradiation. And a binder resin having a polymerized unit in which a linking group is an ether bond. 2. The polymerization unit wherein the linking group is an ether bond,
The following formulas (I), (II) and (III) (Wherein, R ₁ represents a hydroxyl group which may be protected by an acid leaving group, and R _{2 to} R ₄ each independently represent a hydroxyl group, a hydrogen atom and a halogen atom which may be substituted by an acid leaving group. , An alkyl group or a cycloalkyl group, and R ₅ represents a hydrogen atom or an alkyl group which may be substituted with a halogen.
r represents 0 or 1. A represents an alkylene group, an alkylidene group, an oxygen atom, a sulfur atom, or SO ₂ . 2. The composition according to claim 1, which is at least one member selected from the group consisting of: 3. The composition according to claim 1, which acts positively. 4. The composition according to claim 3, wherein the binder resin has a group which is cleaved by the action of an acid, and is itself insoluble or hardly soluble in alkali, but becomes alkali-soluble by the action of acid. 5. The composition according to claim 1, wherein the binder resin itself is alkali-soluble, further contains a crosslinking agent, and acts negatively. 6. The composition according to claim 1, wherein the exposure wavelength is a wavelength of an F2 excimer laser having a wavelength of 157 nm.