JP2002333713A - Positive type resist composition for electron beam or x- ray - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an excellent positive type resist composition for electron beams or X-rays having high sensitivity and high resolution and giving a resist pattern whose profile is rectangular (free from a T-top shape peculiar to a resist for irradiation with electron beams). SOLUTION: The positive type resist composition contains a compound which generates an acid when irradiated with electron beams or X-rays, a resin having the residue of a compound having a smaller ionization potential than p- ethylphenol in a group which is released by the action of the acid and having solubility in an alkali developing solution increased by the action of the acid and at least one acetal compound having a specified structure.

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 for an electron beam or an X-ray, and more particularly to an electron beam having an excellent pattern profile obtained by irradiation with an electron beam or an X-ray, having high sensitivity and high resolution. Or, it relates to a chemically amplified positive resist composition for X-rays.

[0002]

2. Description of the Related Art The degree of integration of integrated circuits is increasing, and in the manufacture of semiconductor substrates such as VLSIs, the processing of ultrafine patterns having a line width of less than half a minute is required. It has become. In order to meet the need, the wavelength of an exposure apparatus used for photolithography is becoming shorter and shorter, and now far ultraviolet light and excimer laser light (XeCl, KrF, ArF, etc.) have been studied. . Furthermore, formation of finer patterns by electron beams or X-rays has been studied.

In particular, electron beams or X-rays are positioned as a next-generation or next-next-generation pattern forming technique, and it is desired to develop positive and negative resist compositions capable of achieving a high sensitivity, a high resolution and a rectangular profile. ing.

Further, in the case of a positive type electron beam or X-ray resist, the surface is easily affected by a basic contaminant in the air or an exposure (drying of a coating film) inside and outside the irradiation apparatus, and the surface becomes hardly soluble. In the case of a line pattern, there is a problem that the surface becomes a T-Top shape (the surface becomes a T-shaped eave), and in the case of a contact hole pattern, the surface becomes a capping shape (an eave is formed on the contact hole surface). .
On the other hand, when the binder is made hydrophilic in order to prevent the capping shape or the T-Top shape, there is a problem that the film is thinned.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a resist pattern profile having high sensitivity and high resolution and having a rectangular resist pattern (particularly a Tt unique to an electron beam resist).
An object of the present invention is to provide an excellent electron beam or X-ray positive resist composition which does not have an op shape.

[0006]

As a result of investigations for high performance, in a positive resist composition for electron beam or X-ray, p-hydroxystyrene unit (p-ethylphenol) Using a polymer having a structure showing an Ip value lower than the ionization potential (Ip: about 8.9 eV) and a specific low-molecular acetal compound, high performance, high resolution, and an excellent resist pattern profile can be obtained. Was found to be. That is, according to the present invention, the following positive resist composition for electron beam or X-ray is provided to achieve the above object.

(A) Compounds which generate an acid upon irradiation with an electron beam or X-ray, (b1) Among the groups which are eliminated by the action of an acid, exhibit an ionization potential value smaller than that of p-ethylphenol. (C) containing at least one of the acetal compounds represented by the general formula (A) or the general formula (B), which has a residue of the compound and whose solubility in an alkaline developer is increased by the action of an acid; A positive resist composition for electron beams or X-rays.

[0008]

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In the formula (A) or (B), R ₁ ′ and R ₂ ′ independently represent an organic group having 1 to 30 carbon atoms. (2) The resin (b1) is obtained by reacting an alkali-soluble polymer having a hydroxyl group with a vinyl ether compound represented by the following general formula (C) and an alcohol compound represented by the following general formula (D) under an acid catalyst. The positive resist composition for electron beam or X-ray according to the above (1), which is a resin obtained.

[0010]

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In the formula (C), R ₃ ′ represents an organic group having 1 to 30 carbon atoms. In the formula (D), W represents a divalent organic group. X
Is an organic group, and the ionization potential of HO-X (I
It is a group in which the value of p) is smaller than the Ip value of p-ethylphenol. n represents the integer of 0-4. n is 2-4
In this case, the plurality of W may be the same or different. (3) (a) a compound capable of generating an acid upon irradiation with an electron beam or X-ray, (b2) a resin having a repeating unit represented by the formula (I) and having increased solubility in an alkali developing solution by the action of an acid And (c) a positive resist composition for an electron beam or X-ray, comprising at least one of the acetal compounds represented by the general formula (A) or the general formula (B) according to claim 1. object.

[0012]

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In the formula (I), R ¹ represents a hydrogen atom or a methyl group. R ² and R ³ each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. W, X and n are as defined above. (4) The positive resist composition for an electron beam or X-ray according to the above (2) or (3), wherein X is represented by the formula (II). -LY (II) In the formula (II), L represents a single bond or an alkylene group. Y is

[0014]

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Represents a group selected from the group R ⁴ represents a linear or branched alkyl group having 1 to 6 carbon atoms independently. n1 represents an integer of 0 to 3, n2 represents an integer of 0 to 7, n3 represents an integer of 0 to 9, n4 represents an integer of 0 to 9, and n5 represents an integer of 0 to 9. (5) The above (1), wherein the total amount of the (c) acetal compound is 0.1 part by weight or more and less than 100 parts by weight based on the total weight of the polymer (b1) or (b2). The positive resist composition for electron beam or X-ray according to any one of (1) to (4). (6) that (a) the compound that generates an acid upon irradiation with an electron beam or X-ray contains at least one of the compounds represented by any of the general formulas (I ′) to (III ′); The positive resist composition for electron beam or X-ray according to any one of the above (1) to (5).

[0016]

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In the formula, R _{1 to} R ₃₇ are the same or different,
A hydrogen atom, a linear, represents branched or cyclic alkyl group, a linear, branched or cyclic alkoxy group, a hydroxyl group, a halogen atom, or an -S-R ₃₈ group. R ₃₈ is
Represents a linear, branched or cyclic alkyl or aryl group. Further, two or more of R _{1 to} R ₁₅ , R _{16 to} R ₂₇ , and R _{28 to} R ₃₇ are combined to form one or two kinds selected from a single bond, carbon, oxygen, sulfur, and nitrogen. A ring including the above may be formed. X ^- represents a sulfonic acid anion.

Hereinafter, preferred embodiments will be described. (7) X ^- is at least one fluorine atom, a linear, branched or cyclic alkyl group substituted with at least one fluorine atom, or a linear or branched alkyl group substituted with at least one fluorine atom. A cyclic or cyclic alkoxy group, an acyl group substituted with at least one fluorine atom, an acyloxy group substituted with at least one fluorine atom, a sulfonyl group substituted with at least one fluorine atom,
Sulfonyloxy group substituted with at least one fluorine atom, sulfonylamino group substituted with at least one fluorine atom, aryl group substituted with at least one fluorine atom, substituted with at least one fluorine atom An aralkyl group, and an anion of benzenesulfonic acid, naphthalenesulfonic acid, or anthracenesulfonic acid having at least one selected from an alkoxycarbonyl group substituted with at least one fluorine atom. (6) A positive resist composition for electron beam or X-ray.

(8) The positive resist composition for an electron beam or X-ray according to any one of the above (1) to (7), which mainly contains propylene glycol monomethyl ether acetate as a solvent.

(9) The positive resist composition for electron beam or X-ray according to any one of the above (1) to (8), further comprising (e) an organic basic compound.

(10) (f) The positive type for electron beam or X-ray according to any one of the above (1) to (9), further comprising a fluorine-based and / or silicon-based surfactant. Resist composition.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION The positive resist composition for electron beam or X-ray of the present invention (hereinafter also referred to as positive electron beam or X-ray resist composition) will be described.

[I] (a) Compound that generates an acid upon irradiation with an electron beam or X-ray (hereinafter also referred to as “component (a)”) Component (a) includes an acid upon irradiation with an electron beam or X-ray. Any compound can be used as long as it generates, but the compounds represented by formulas (I ') to (III') are preferred.

In the general formulas (I ′) to (III ′), R ₁ to
_Examples of the linear or branched alkyl group for R ₃₈ include a carbon atom such as a methyl group, an ethyl group, a propyl group, an n-butyl group, a sec-butyl group and a t-butyl group which may have a substituent. Examples of the number 1 to 4 are given. Examples of the cyclic alkyl group include those having 3 to 8 carbon atoms which may have a substituent, such as a cyclopropyl group, a cyclopentyl group and a cyclohexyl group. Examples of the linear or branched alkoxy group for R _{1 to} R ₃₇ include a methoxy group, an ethoxy group,
Those having 1 to 4 carbon atoms such as a hydroxyethoxy group, a propoxy group, an n-butoxy group, an isobutoxy group, a sec-butoxy group and a t-butoxy group are exemplified. Examples of the cyclic alkoxy group include a cyclopentyloxy group and a cyclohexyloxy group. R _{1 to} R ₃₇
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. Examples of the aryl group for R ₃₈ include those having 6 to 14 carbon atoms which may have a substituent such as a phenyl group, a tolyl group, a methoxyphenyl group, and a naphthyl group.

These substituents are preferably an alkoxy group having 1 to 4 carbon atoms, a halogen atom (a fluorine atom,
A chlorine atom, an iodine atom), an aryl group having 6 to 10 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, a cyano group, a hydroxy group, a carboxy group, an alkoxycarbonyl group, and a nitro group.

Further, R _{1 to} R ₁₅ , R _{16 to} R ₂₇ , R _{28 to} R
Of _37, two or more of formed by combining a single bond, carbon, oxygen, one selected sulfur, and nitrogen or 2
Examples of the ring containing more than one kind include a furan ring, a dihydrofuran ring, a pyran ring, a trihydropyran ring, a thiophene ring, a pyrrole ring, and the like.

In the general formulas (I ′) to (III ′), X ⁻ is a sulfonic acid anion. As a further example, CF ₃
SO ₃ ^-, etc. perfluoroalkane sulfonate anion,
Examples thereof include, but are not limited to, condensed polynuclear aromatic sulfonic acid anions such as pentafluorobenzenesulfonic acid anion and naphthalene-1-sulfonic acid anion, anthraquinonesulfonic acid anion, and a sulfonic acid group-containing dye.

Among them, X ^- is more preferably an anion of benzenesulfonic acid, naphthalenesulfonic acid or anthracenesulfonic acid having at least one selected from the following groups. At least one fluorine atom, a linear, branched or cyclic alkyl group substituted with at least one fluorine atom; a linear, branched or cyclic alkoxy group substituted with at least one fluorine atom. Acyl group substituted with a fluorine atom acyloxy group substituted with at least one fluorine atom sulfonyl group substituted with at least one fluorine atom sulfonyloxy group substituted with at least one fluorine atom at least one fluorine Sulfonylamino group substituted with an atom Aryl group substituted with at least one fluorine atom Aralkyl group substituted with at least one fluorine atom and alkoxycarbonyl group substituted with at least one fluorine atom

The linear, branched or cyclic alkyl group preferably has 1 to 12 carbon atoms and is substituted with 1 to 25 fluorine atoms. Specifically, trifluoromethyl group, pentafluoroethyl group, 2,
Examples thereof include a 2,2-trifluoroethyl group, a heptafluoropropyl group, a heptafluoroisopropyl group, a perfluorobutyl group, a perfluorooctyl group, a perfluorododecyl group and a perfluorocyclohexyl group. Among them, a perfluoroalkyl group having 1 to 4 carbon atoms, all of which is substituted by fluorine, is preferable.

The linear, branched or cyclic alkoxy group preferably has 1 to 12 carbon atoms and is substituted with 1 to 25 fluorine atoms. Specifically, a trifluoromethoxy group, a pentafluoroethoxy group,
Examples include a heptafluoroisopropyloxy group, a perfluorobutoxy group, a perfluorooctyloxy group, a perfluorododecyloxy group, a perfluorocyclohexyloxy group, and the like. Among them, a perfluoroalkoxy group having 1 to 4 carbon atoms, all of which is substituted by fluorine, is preferable.

The acyl group has 2 to 12 carbon atoms.
Wherein those substituted with 1 to 23 fluorine atoms are preferred. Specific examples include a trifluoroacetyl group, a fluoroacetyl group, a pentafluoropropionyl group, and a pentafluorobenzoyl group.

The acyloxy group has 2 to 2 carbon atoms.
12 which is substituted with 1 to 23 fluorine atoms is preferred. Specific examples include a trifluoroacetoxy group, a fluoroacetoxy group, a pentafluoropropionyloxy group, and a pentafluorobenzoyloxy group.

The sulfonyl group has a carbon number of 1 to 1.
12 which is substituted with 1 to 25 fluorine atoms is preferred. Specific examples include a trifluoromethanesulfonyl group, a pentafluoroethanesulfonyl group, a perfluorobutanesulfonyl group, a perfluorooctanesulfonyl group, a pentafluorobenzenesulfonyl group, and a 4-trifluoromethylbenzenesulfonyl group.

The sulfonyloxy group preferably has 1 to 12 carbon atoms and is substituted with 1 to 25 fluorine atoms. Specific examples include a trifluoromethanesulfonyloxy group, a perfluorobutanesulfonyloxy group, and a 4-trifluoromethylbenzenesulfonyloxy group.

The sulfonylamino group preferably has 1 to 12 carbon atoms and is substituted with 1 to 25 fluorine atoms. Specific examples include a trifluoromethanesulfonylamino group, a perfluorobutanesulfonylamino group, a perfluorooctanesulfonylamino group, and a pentafluorobenzenesulfonylamino group.

The aryl group has 6 to 1 carbon atoms.
4, which is substituted with 1 to 9 fluorine atoms is preferable. Specifically, a pentafluorophenyl group, 4
-Trifluoromethylphenyl, heptafluoronaphthyl, nonafluoroanthranyl, 4-fluorophenyl, 2,4-difluorophenyl, and the like.

The aralkyl group has 7 to 7 carbon atoms.
It is preferably 10 and substituted by 1 to 15 fluorine atoms. Specific examples include a pentafluorophenylmethyl group, a pentafluorophenylethyl group, a perfluorobenzyl group, a perfluorophenethyl group, and the like.

The alkoxycarbonyl group preferably has 2 to 13 carbon atoms and is substituted by 1 to 25 fluorine atoms. Specific examples include a trifluoromethoxycarbonyl group, a pentafluoroethoxycarbonyl group, a pentafluorophenoxycarbonyl group, a perfluorobutoxycarbonyl group, and a perfluorooctyloxycarbonyl group.

[0039] The most preferred X ^- is a fluorine-substituted benzenesulfonic acid anion, among others pentafluorobenzenesulfonic acid anion is particularly preferred.

The benzenesulfonic acid, naphthalenesulfonic acid or anthracenesulfonic acid having a fluorine-containing substituent further includes a linear, branched or cyclic alkoxy group, an acyl group, an acyloxy group, a sulfonyl group,
It may be substituted with a sulfonyloxy group, a sulfonylamino group, an aryl group, an aralkyl group, an alkoxycarbonyl group (the number of carbon atoms is the same as described above), a halogen (excluding fluorine), a hydroxyl group, a nitro group and the like.

Specific examples of the compound represented by formula (I ') are shown below.

[0042]

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[0043]

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[0044]

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[0045]

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[0046]

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Specific examples of the compound represented by the general formula (II ') are shown below.

[0048]

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[0049]

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Specific examples of the compound represented by formula (III ') are shown below.

[0051]

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[0052]

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[0053]

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[0054]

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Examples of acid generators other than the compounds represented by formulas (I ') to (III') are shown below.

[0056]

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[0057]

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[0058]

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The compounds represented by formulas (I ′) to (III ′) may be used alone or in combination of two or more.

The compounds of the general formulas (I ') and (II') are prepared by reacting an aryl Grignard reagent such as arylmagnesium bromide with a substituted or unsubstituted phenylsulfoxide to give the resulting triarylsulfonium halide. A method of performing salt exchange with a sulfonic acid to be converted, a method of subjecting a substituted or unsubstituted phenyl sulfoxide and a corresponding aromatic compound to condensation and salt exchange using an acid catalyst such as methanesulfonic acid / diphosphorus pentoxide or aluminum chloride,
Alternatively, it can be synthesized by a method of condensation and salt exchange between a diaryliodonium salt and a diaryl sulfide using a catalyst such as copper acetate. The compound of the formula (III ′) can be synthesized by reacting an aromatic compound with periodate. The sulfonic acid or sulfonic acid salt used for the salt exchange is obtained by, for example, a method of hydrolyzing a commercially available sulfonic acid chloride, a method of reacting an aromatic compound with chlorosulfonic acid, or a method of reacting an aromatic compound with sulfamic acid. Can be obtained by

The specific formulas (I ′) to (III ′)
The method for synthesizing the specific compound is shown below. (Synthesis of Pentafluorobenzenesulfonic Acid Tetramethylammonium Salt) 25 g of pentafluorobenzenesulfonyl chloride was dissolved in 100 ml of methanol under ice cooling.
To this was slowly added 100 g of a 25% aqueous solution of tetramethylammonium hydroxide. After stirring at room temperature for 3 hours, a solution of pentafluorobenzenesulfonic acid tetramethylammonium salt was obtained. This solution was used for salt exchange with sulfonium salt and iodonium salt.

(Synthesis of Triphenylsulfonium pentafluorobenzenesulfonate: Synthesis of Specific Example (I-1)) Diphenylsulfoxide 509 was converted to benzene 800 m
1 and 200 g of aluminum chloride was added thereto and refluxed for 24 hours. The reaction solution was slowly poured into 2 L of water, and 400 ml of concentrated hydrochloric acid was added thereto, followed by heating at 70 ° C. for 10 minutes. This aqueous solution was washed with 500 ml of ethyl acetate,
After filtration, 200 g of ammonium iodide was added to 400 m of water.
The solution dissolved in 1 was added. The precipitated powder was collected by filtration, washed with water, washed with ethyl acetate and dried to obtain 70 g of triphenylsulfonium iodide. 30.5 g of triphenylsulfonium iodide was added to 1000 ml of methanol.
And 19.1 g of silver oxide was added to the solution, followed by stirring at room temperature for 4 hours. The solution was filtered, and an excess amount of the solution of tetramethylammonium pentafluorobenzenesulfonate synthesized above was added thereto. The reaction solution was concentrated, and this was dissolved in 500 ml of dichloromethane.
% Tetramethylammonium hydroxide aqueous solution and water. After drying the organic phase over anhydrous sodium sulfate,
Concentration provided triphenylsulfonium pentafluorobenzenesulfonate.

(Synthesis of Triarylsulfonium Pentafluorobensene Sulfonate: Specific Examples (I-9) and (II)
Synthesis of mixture with -1)) 50 g of triarylsulfonium chloride (50% aqueous solution of triphenylsulfonium chloride, manufactured by Fluka) is dissolved in 500 ml of water, and an excess amount of a solution of pentafluorobenzenesulfonic acid tetramethylammonium salt is added thereto. And an oily substance precipitated. The supernatant was removed by decantation, and the obtained oily substance was washed with water and dried to obtain triarylsulfonium pentafluorobenzensulfonate (specific examples (I-9) and (II-1)).
) As a main component.

(Synthesis of di (4-t-amylphenyl) iodonium pentafluorobensensulfonate: Synthesis of Specific Example (III-1)) 60 g of t-amylbenzene, 39.5 g of potassium iodate, 81 g of acetic anhydride, 170 ml of dichloromethane And 66.8 concentrated sulfuric acid under ice-cooling.
g was slowly added dropwise. After stirring for 2 hours under ice cooling, the mixture was stirred at room temperature for 10 hours. To the reaction mixture was added 500 ml of water under ice cooling, and the mixture was extracted with dichloromethane. The organic phase was washed with sodium bicarbonate and water, and concentrated to obtain di (4-t-amylphenyl) iodonium sulfate. This sulfate was added to a solution of an excess amount of tetramethylammonium pentafluorobenzenesulfonate. To this solution was added 500 ml of water, and the mixture was extracted with dichloromethane. The organic phase was washed with a 5% aqueous solution of tetramethylammonium hydroxide and water, and then concentrated to obtain di (4-t-amylphenyl) iodonium pentafluorobenzenesulfonate. Was done. Other compounds can be synthesized using the same method.

The component (a) used in the present invention comprises:
The compounds are not limited to compounds that generate an acid upon being decomposed by irradiation with the above-mentioned electron beam or X-ray, and include a photoinitiator for photocationic polymerization, a photoinitiator for photoradical polymerization, a photodecolorant for dyes, Known compounds that generate an acid upon irradiation with an electron beam or X-ray used for a color changing agent or a micro resist or the like, and a mixture thereof can be appropriately selected and used.

For example, SISchlesinger, Photogr.Sci.E
ng., 18,387 (1974), TSBal etal, Polymer, 21,423 (198
0) etc., U.S. Pat.No.4,069,055
No. 4,069,056, Re 27,992, Japanese Patent Application No. 3-140,140
Salt, DCNecker etal, Macrom
olecules, 17, 2468 (1984), CSwen et al, Teh, Proc. Con
f.Rad.Curing ASIA, p478 Tokyo, Oct (1988), U.S. Patent No.
Nos. 4,069,055 and 4,069,056, and phosphonium salts described in JVCrivello et al., Macromorecules, 10 (6), 1307 (19
77), Chem. & Eng. News, Nov. 28, p31 (1988), European Patent No. 10
No. 4,143, U.S. Pat.Nos. 339,049, 410,201, JP-A-2-150,848, iodonium salts described in JP-A-2-296,514, etc., JVCrivello et al., Polymer J. 17, 73 (1985),
JVCrivelloetal.J.Org.Chem., 43, 3055 (1978), WRWa
tt etal, J. Polymer Sci., Polymer Chem. Ed., 22, 1789 (19
84), JVCrivello etal, Polymer Bull., 14,279 (198
5), JVCrivello etal, Macromorecules, 14 (5), 1141 (19
81), JVCrivello etal, J. PolymerSci., Polymer Che
m.Ed., 17,2877 (1979), European Patent Nos. 370,693, 3,90
No. 2,114, No. 233,567, No. 297,443, No. 297,442, U.S. Pat.Nos. 4,933,377, 161,811, No. 410,201, No. 3
No. 39,049, No. 4,760,013, No. 4,734,444, No. 2,833,82
No. 7, Dokoku Patent Nos. 2,904,626, 3,604,580, 3,60
No. 4,581, etc., sulfonium salt, JVCrivello eta
l, Macromorecules, 10 (6), 1307 (1977), JVCrivello et
al, J. PolymerSci., Polymer Chem. Ed., 17,1047 (1979)
Selenonium salts, CSwen et al, Teh, Proc.Co
Onium salts such as arsonium salts described in nf.Rad.Curing ASIA, p478 Tokyo, Oct (1988), U.S. Pat.
No., JP-B-46-4605, JP-A-48-36281, JP-A-55-3
No. 2070, JP-A-60-239736, JP-A-61-169835, JP-A-61-169837, JP-A-62-58241, JP-A-62-212401
No., JP-A-63-70243, organic halogen compounds described in JP-A-63-298339, K. Meier et al., J. Rad.Curing, 13
(4), 26 (1986), TPGill et al., Inorg.Chem., 19, 3007 (1
980), D. Astruc, Acc. Chem. Res., 19 (12), 377 (1896), and organometallic / organic halides described in JP-A-2-14145, S. Hayase et al., J. Polymer Sci. ., 25,753 (1987), ER
eichmanis etal, J.Pholymer Sci., Polymer Chem.Ed., 2
3,1 (1985), QQ Zhuetal, J. Photochem., 36, 85, 39, 317 (19
87), B. Amit etal, Tetrahedron Lett., (24) 2205 (1973),
DHR Barton et al., J. Chem Soc., 3571 (1965), PMCol
lins et al., J. Chem.SoC., Perkin I, 1695 (1975), M. Rudins
tein etal, Tetrahedron Lett., (17), 1445 (1975), JWW
alker etal J. Am. Chem. Soc., 110, 7170 (1988), SCBusma
n etal, J. Imaging Technol., 11 (4), 191 (1985), HMHoul
ihan etal, Macormolecules, 21, 2001 (1988), PMCollins
etal, J. Chem. Soc., Chem. Commun., 532 (1972), S. Hayase
etal, Macromolecules, 18, 1799 (1985), E. Reichmanis eta
l, J.Electrochem.Soc., Solid State Sci.Technol., 130
(6), FM Houlihan et al, Macromolcules, 21, 2001 (198
8), European Patent Nos. 0290,750, 046,083, 156,535
No. 271,851, No. 0,388,343, U.S. Pat.No. 3,901,7
No. 10, 4,181,531, JP-A-60-198538, JP-A-53-1
Photoacid generator having an o-nitrobenzyl-type protecting group described in No. 33022, M. TUNOOKA et al., Polymer Preprints Ja
pan, 35 (8), G. Berner et al., J. Rad. Curing, 13 (4), WJMij
s etal, Coating Technol., 55 (697), 45 (1983), Akzo, H.Ad
achi etal, Polymer Preprints, Japan, 37 (3), European Patent Nos. 0199,672, 84515, 199,672, 044,115
Nos. 0101,122; U.S. Pat.Nos. 618,564; 4,371,605
No. 4,431,774, JP-A-64-18143, JP-A-2-24575
No. 6, iminosulfone described in Japanese Patent Application No. 3-140109, etc.
And disulfone compounds described in JP-A-61-166544 and the like.

Compounds in which an acid or a group capable of generating an acid upon irradiation with an electron beam or X-ray is introduced into a main chain or a side chain of a polymer, for example, ME Woodhouse e.
tal, J. Am. Chem. Soc., 104, 5586 (1982), SPPappas eta
l, J.Imaging Sci., 30 (5), 218 (1986), S.Kondo et al., Mak
romol.Chem., Rapid Commun., 9,625 (1988), Y.Yamadaeta
l, Makromol. Chem., 152, 153, 163 (1972), JVCrivello
etal, J. Polymer Sci., Polymer Chem. Ed., 17, 3845 (197
9), U.S. Patent No. 3,849,137, Dokoku Patent No. 3,914,407, JP-A-63-26653, JP-A-55-164824, JP-A-62-69263
Compounds described in JP-A-63-146038, JP-A-63-163452, JP-A-62-153853, JP-A-63-146029 and the like can be used.

Further, VNRPillai, Synthesis, (1), 1 (198
0), A. Abad etal, Tetrahedron Lett., (47) 4555 (1971),
Compounds that generate an acid by light described in DHR Barton et al., J. Chem. Soc., (C), 329 (1970), U.S. Pat. No. 3,779,778, and EP 126,712 can also be used.

Among the compounds which can be used together and decompose by irradiation with an electron beam or X-ray to generate an acid, those which are particularly effectively used are described below. (1) The following general formula (PAG) substituted with a trihalomethyl group
The oxazole derivative represented by 1) or the general formula (PAG)
An S-triazine derivative represented by 2).

[0070]

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In the formula, R ²⁰¹ is a substituted or unsubstituted aryl group or alkenyl group, and R ²⁰² is a substituted or unsubstituted aryl group, alkenyl group, alkyl group, —C (Y) ₃
Show Y represents a chlorine atom or a bromine atom. Specific examples include the following compounds, but the present invention is not limited thereto.

[0072]

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[0073]

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[0074]

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(2) Disulfone derivatives represented by the following formula (PAG5) or iminosulfonate derivatives represented by the following formula (PAG6).

[0076]

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Where Ar^Three, Ar^FourAre each independently substituted
Or an unsubstituted aryl group. R ²⁰⁶ Is replaced or
It represents an unsubstituted alkyl group or aryl group. A is a substitution
Or unsubstituted alkylene, alkenylene, arylene
Shows a substituent group. Specific examples include the compounds shown below.
However, the present invention is not limited to these.

[0078]

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[0079]

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[0080]

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[0081]

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[0082]

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The component (a) may be used alone or as a mixture of two or more. The total content as the component (a) is usually 0.1 to 20% by weight, preferably 0.5 to 10% by weight, based on the solid content of the whole positive electron beam or X-ray resist composition of the present invention. %, More preferably 1 to 7% by weight
It is.

[II] Acid-Decomposable Resin The resin used in the present invention is an acid-decomposable resin having a leaving group containing a residue of a compound having an Ip value smaller than the ionization potential (Ip) value of p-ethylphenol. It is a resin whose solubility in an alkali developing solution increases due to its action. Here, the Ip value indicates a value calculated by molecular orbital calculation by MOPAC. The molecular orbital calculation by MOPAC is described in James JP. Stewart, Journal of Compute
r-Aided Molecular Design Vol.4, No.1 (1990), pp.1-
105. This molecular orbital calculation can be performed by using, for example, software CAChe of Oxford Molecular. Note that the PM3 parameter is preferable as a parameter used in this calculation. The Ip value is preferably less than 8.9, more preferably 8.6 or less, even more preferably 8.2 or less. The lower limit is not particularly limited, but is preferably 2 or more, more preferably 3 or more, and still more preferably 4 or more.

In the present invention, the residue of a compound having an Ip value smaller than p-ethylphenol means a group obtained by removing one hydrogen atom from a compound having the Ip value.

The resin of the present invention preferably has, as the repeating unit having a leaving group, a repeating unit represented by the above general formula (I). In the formula (I), R ¹
Is a hydrogen atom or a methyl group, R ² and R ³ are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, W is a divalent organic group, X is an organic group, and Ip of H—O—X The value is p-
It is smaller than the Ip value of ethylphenol. n is an integer of 0 to 4, preferably 1 or 2. n
Are plural, the plural W may be the same or different. The leaving group in the formula (I) corresponds to a group from a carbon atom to which R ² and R ³ are commonly bonded to X.

The divalent organic group represented by W is selected from the group consisting of alkylene, cycloalkylene, ether, thioether, carbonyl, ester, amide, sulfonamide, urethane, and urea groups. Represents a single or a combination of two or more groups. Examples of the alkylene group include groups represented by the following formula. -[C (Rf) (Rg)] r- In the above formula, Rf and Rg represent a hydrogen atom, an alkyl group, a substituted alkyl group, or an alkoxy group, and they may be the same or different. The alkyl group is preferably a lower alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group and a butyl group, and more preferably selected from a methyl group, an ethyl group, a propyl group and an isopropyl group. Examples of the substituent of the substituted alkyl group include an alkoxy group. As the alkoxy group, a methoxy group,
C1-C1 such as ethoxy, propoxy and butoxy groups
4 can be mentioned. r is an integer of 1 to 10. The cycloalkylene group has 3 to 10 carbon atoms.
And a cyclopentylene group, a cyclohexylene group, a cyclooctylene group and the like.

Examples of the alkyl group having 1 to 4 carbon atoms as R ² and R ³ include a methyl group, an ethyl group, a propyl group, an n-butyl group, an iso-butyl group, an s-butyl group and a t-butyl group. No.

It is preferable that X in the formula (I) is a structure represented by the formula (II). -LY (II) In the formula (II), L is a single bond or an alkylene group, and Y is

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Represents a group selected from Here, R ⁴ represents a linear or branched alkyl group having 1 to 6 carbon atoms. Examples of the alkylene group as L include a group represented by the following formula. -[C (Rf) (Rg)] r- In the above formula, Rf and Rg represent a hydrogen atom, an alkyl group, a substituted alkyl group, or an alkoxy group, and they may be the same or different. The alkyl group is preferably an alkyl group having 1 to 4 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, and a butyl group, and more preferably selected from a methyl group, an ethyl group, a propyl group, and an isopropyl group. . Examples of the substituent of the substituted alkyl group include an alkoxy group (preferably having 1 to 4 carbon atoms).
Examples of the alkoxy group include those having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group and a butoxy group. r is an integer of 1 to 10.

The linear or branched alkyl group having 1 to 6 carbon atoms as R ⁴ includes a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group and the like, and has a substituent. You may. Examples of the substituent include a halogen atom, an alkoxy group, an alkoxycarbonyl group, an acyl group, and an acyloxy group, and preferably have 10 or less carbon atoms.

Examples of the monomer of the repeating unit having a leaving group according to the present invention include substituted styrenes represented by p-hydroxystyrene, m-hydroxystyrene, vinylbenzoic acid, styrenesulfonic acid, etc., and (meth) acrylic. Acid esters,
Compounds having at least one addition-polymerizable unsaturated bond selected from (meth) acrylic amide, maleic anhydride, fumaric esters, maleimides, allyl compounds, vinyl ethers, vinyl esters, and the like are included.

(B1) or (b) used in the present invention
The polymer of 2) can be obtained by subjecting a part of the phenolic hydroxyl group of the trunk polymer having a phenolic hydroxyl group to an acetalization reaction using a corresponding vinyl ether compound and an acid catalyst. For example, Japanese Patent Application Laid-Open
249682, JP-A-8-123032, JP-A-10-
Acetal groups can be introduced by the method described in 221854. Further, the polymer (b1) or (b2) used in the present invention is a polymer described in J. Photopolym. Sci. Tech.,
It is possible to introduce a desired acetal group using the acetal exchange reaction of S. Malik described in 11 (3) 431 (1998). That is, the polymer (b1) or (b2) used in the present invention includes an alkali-soluble polymer having a hydroxyl group, a vinyl ether compound represented by the general formula (C), and an alcohol compound represented by the general formula (D). And a resin obtained by reacting the above with an acid catalyst. Here, as the alkali-soluble polymer having a hydroxyl group, a resin having a phenolic hydroxyl group is preferable, and polyhydroxystyrene or a polyhydroxystyrene copolymer is more preferable. Here, as the acid catalyst, p-toluenesulfonic acid, p-toluenesulfonic acid pyridinium salt or the like can be used. In this method, for example, as shown in the following reaction formula, a resin having a phenolic hydroxyl group, a vinyl ether compound represented by the general formula (C) and an alcohol compound represented by the general formula (D) are reacted in the presence of an acid catalyst. By reacting, only R ₃ and R ₄ or R ₄ can be introduced as an acetal group as shown in the following general formula (F).

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In the present invention, the acetalization method is preferably an acetal exchange reaction which can be carried out using an easily available alcohol without synthesizing a reaction precursor (vinyl ether). Hereinafter, specific examples of the repeating unit having a leaving group used in the present invention will be described, but the present invention is not limited thereto.

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The acid-decomposable resin of the present invention is a monomer of the repeating unit having a specific leaving group of the present invention, and if necessary, a monomer of a repeating unit having another leaving group (acid-decomposable group). It can be synthesized by polymerizing a monomer with a monomer having no acid-decomposable group.

That is, various repeating structural units are used for the purpose of adjusting dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and resolution, heat resistance, sensitivity, and the like, which are general necessary characteristics of a resist. Can be contained.

Examples of such a repeating structural unit include, but are not limited to, repeating structural units corresponding to the following monomers. Thereby, the performance required for the acid-decomposable resin, in particular, (1) solubility in a coating solvent, (2) film-forming property (glass transition point),
Fine adjustment of (3) alkali developability, (4) film loss (hydrophobicity, selection of alkali-soluble group), (5) adhesion of unexposed portion to substrate, (6) dry etching resistance, etc. becomes possible. .

As such a monomer, for example, an addition-polymerizable unsaturated bond selected from acrylates, methacrylates, acrylamides, methacrylamides, allyl compounds, vinyl ethers, vinyl esters and the like can be used. And the like.

The following monomers can be specifically mentioned. Acrylic esters (preferably alkyl acrylates having 1 to 10 carbon atoms in the alkyl group): methyl acrylate, ethyl acrylate, propyl acrylate,
Amyl acrylate, cyclohexyl acrylate, ethyl hexyl acrylate, octyl acrylate, tert-octyl acrylate, chloroethyl acrylate, 2-hydroxyethyl acrylate 2,2-dimethylhydroxypropyl acrylate, 5-hydroxypentyl acrylate, trimethylolpropane Monoacrylate, pentaerythritol monoacrylate, benzyl acrylate, methoxybenzyl acrylate, furfuryl acrylate, tetrahydrofurfuryl acrylate and the like.

Methacrylic esters (preferably alkyl methacrylate having an alkyl group having 1 to 10 carbon atoms): methyl methacrylate, ethyl methacrylate,
Propyl methacrylate, isopropyl methacrylate, amyl methacrylate, hexyl methacrylate,
Cyclohexyl methacrylate, benzyl methacrylate, chlorobenzyl methacrylate, octyl methacrylate, 2-hydroxyethyl methacrylate, 4-hydroxybutyl methacrylate, 5-hydroxypentyl methacrylate, 2,2-dimethyl-3-hydroxypropyl methacrylate, trimethylolpropane monomethacrylate, penta Erythritol monomethacrylate, furfuryl methacrylate, tetrahydrofurfuryl methacrylate and the like.

Acrylamides: acrylamide, N-
Alkyl acrylamide (the alkyl group has 1 carbon atom
And 10 such as methyl, ethyl, propyl, butyl, t-butyl, heptyl, octyl, cyclohexyl, and hydroxyethyl. ), N, N-dialkylacrylamide (alkyl group having 1 to 10 carbon atoms, for example, methyl group, ethyl group, butyl group, isobutyl group, ethylhexyl group,
A cyclohexyl group, etc.), N-hydroxyethyl-
N-methylacrylamide, N-2-acetamidoethyl-N-acetylacrylamide and the like.

Methacrylamides: methacrylamide,
N-alkyl methacrylamide (an alkyl group having 1 to 10 carbon atoms, such as a methyl group, an ethyl group,
Butyl group, ethylhexyl group, hydroxyethyl group, cyclohexyl group, etc.), N, N-dialkylmethacrylamide (alkyl group includes ethyl group, propyl group, butyl group, etc.), N-hydroxyethyl-N-
Methyl methacrylamide and the like.

Allyl compounds: allyl esters (eg, allyl acetate, allyl caproate, allyl caprylate, allyl laurate, allyl palmitate, allyl stearate, allyl benzoate, allyl acetoacetate, allyl lactate, etc.), allyloxyethanol etc.

Vinyl ethers: alkyl vinyl ethers (eg, hexyl vinyl ether, octyl vinyl ether, decyl vinyl ether, ethylhexyl vinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether, chloroethyl vinyl ether, 1
-Methyl-2,2-dimethylpropyl vinyl ether,
2-ethylbutyl vinyl ether, hydroxyethyl vinyl ether, diethylene glycol vinyl ether,
Dimethylaminoethyl vinyl ether, diethylaminoethyl vinyl ether, butylaminoethyl vinyl ether, benzyl vinyl ether, tetrahydrofurfuryl vinyl ether and the like.

Vinyl esters: vinyl butyrate, vinyl isobutyrate, vinyl trimethyl acetate, vinyl diethyl acetate, vinyl valate, vinyl caproate, vinyl chloroacetate, vinyl dichloroacetate, vinyl methoxy acetate, vinyl butoxy acetate, vinyl Acetoacetate, vinyl lactate, vinyl-β-phenylbutyrate, vinylcyclohexylcarboxylate and the like.

Dialkyl itaconates: dimethyl itaconate, diethyl itaconate, dibutyl itaconate and the like. Dialkyl esters or monoalkyl esters of fumaric acid; dibutyl fumarate;

Others crotonic acid, itaconic acid, acrylonitrile, methacrylonitrile, maleilenitrile and the like.

In addition, as long as it is an addition-polymerizable unsaturated compound copolymerizable with a monomer corresponding to the above-mentioned various repeating structural units, it may be copolymerized.

In the acid-decomposable resin, the molar ratio of each repeating structural unit depends on the dry etching resistance of the resist, the suitability for a standard developing solution, the substrate adhesion, the resist profile, and the resolution, which is a general required performance of the resist, heat resistance. It is set as appropriate to adjust properties, sensitivity, and the like.

The acid-decomposable resin in the present invention can be synthesized by a known method such as radical polymerization, cationic polymerization, anionic polymerization and the like. It is easiest to perform radical polymerization by combining corresponding monomers, but depending on the type of monomer, more preferable synthesis can be achieved by using cationic polymerization or anionic polymerization. Further, when the monomer causes a reaction other than polymerization depending on the type of the polymerization initiator, a desired polymer can be obtained by polymerizing a monomer having an appropriate protecting group introduced and deprotecting after polymerization. Regarding the polymerization method, Experimental Chemistry Course 28 Polymer Synthesis, New Experimental Chemistry Course 19
It is described in Polymer Chemistry [I] and the like.

The content of the monomer of the repeating unit having a leaving group of the present invention in the acid-decomposable resin is generally 5 to 40 mol%, preferably 10 to 10 mol%, based on all repeating units.
25 mol%.

The acid-decomposable resin of the present invention has a molecular weight of more than 3,000 and not more than 1,000,000. Preferably, the weight average molecular weight is more than 3,000 and 50
It is less than 000. More preferably, the weight average molecular weight is more than 3,000 and not more than 100,000.

The molecular weight distribution (Mw / Mn) of the acid-decomposable resin that can be synthesized by the above-mentioned synthesis method is preferably 1.0 to 1.5, whereby the sensitivity of the resist can be particularly increased. . The resin having such a molecular weight distribution can be synthesized by utilizing living anion polymerization in the above synthesis method.

(C) Acetal compounds. The component (c) in the present invention is a compound represented by the general formula (A) and / or the general formula (B). R ₁ 'and R ₂ '
Each independently represents an organic group having 1 to 30 carbon atoms. The organic group preferably has 2 to 20 carbon atoms.
And more preferably 4 to 16. Examples of the organic group having 1 to 30 carbon atoms for R ₁ ′ and R ₂ ′ include a linear, branched, or cyclic alkyl group which may have a substituent, and an aryl group which may have a substituent. Or an aralkyl group which may have a substituent.

Examples of the linear, branched or cyclic alkyl group include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, t-butyl, hexyl, 2- Ethylhexyl group, octyl group,
Examples thereof include an alkyl group having 1 to 12 carbon atoms such as a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, and a 1-adamantylethyl group. Further substituents of these alkyl groups include a hydroxyl group, a fluorine atom, a chlorine atom, a bromine atom, a halogen atom such as iodine, an amino group, a nitro group, a cyano group, a carbonyl group, an ester group, an alkoxy group, and a hetero atom. And a substituent having a cycloalkyl group, an aryloxy group, and a sulfonyl group. Here, the carbonyl group is preferably an alkyl-substituted carbonyl group or an aromatic-substituted carbonyl group, the ester group is preferably an alkyl-substituted ester group or an aromatic-substituted ester group, and the alkoxy group is preferably a methoxy group, an ethoxy group, or a propoxy group. And a t-butoxy group and the like.
Examples of the cycloalkyl group include a cyclohexyl group,
Examples thereof include an adamantyl group, a cyclopentyl group, and a cyclopropyl group. Examples of the group containing a hetero atom include an oxolanyl group. As the aryloxy group,
Examples include a phenoxy group, and the aryl group may have a substituent. Examples of the substituent having a sulfonyl group include an alkylsulfonyl group such as a methylsulfonyl group and an ethylsulfonyl group, and an arylsulfonyl group such as a phenylsulfonyl group.

Examples of the aryl group include benzene, naphthalene, phenanthrene, anthracene, and pyrene skeletons as the skeleton of the aromatic ring. Specifically, the aryl group has 6 to 3 carbon atoms.
There may be zero phenyl groups, naphthyl groups, phenanthrenyl groups, anthracenyl groups and the like. These aryl groups can have, as substituents, those described for further substituents of the alkyl group. Examples of the aralkyl group include benzene, naphthalene, phenanthrene, anthracene, and a pyrene skeleton as a skeleton of an aromatic ring. And a naphthylmethyl group. These aralkyl groups can have, as substituents, those described for further substituents of the alkyl group. The organic group having 1 to 30 carbon atoms of R ₁ ′ and R ₂ ′ is preferably a methyl group,
Ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, t-butyl group, n-pentyl group,
n-hexyl group, cyclohexyl group, cyclohexylethyl group, phenyl group, phenylmethyl group, phenylethyl group, 3,4-dimethoxyphenyl group, 3,4,5-trimethoxyphenyl group, 3,4-dimethoxyphenylmethyl group A 3,4,5-trimethoxyphenylmethyl group,
1-naphthyl group, 2-naphthyl group, 4-methoxy-1-
Naphthyl group, 2- (1-naphthyl) ethyl group, 9-anthrylmethyl group, 10-methoxy-1-anthryl group,
A 9-phenanthrene group and a 1-pyrenylmethyl group.

As a method for synthesizing the above acetal compound,
It can be synthesized by dissolving a vinyl ether compound and a corresponding alcohol compound in an appropriate solvent and reacting in the presence of an acid catalyst. Here, as the acid catalyst, p-
Toluenesulfonic acid, p-toluenesulfonic acid pyridinium salt and the like can be used. The reaction may involve an acetal exchange reaction and may be obtained as a mixture of a plurality of acetal compounds. However, a single substance or a mixture can be suitably used for the purpose of the present invention. The vinyl ether compound and the alcohol compound can be represented by the general formulas (C) and (D), respectively. In the general formula (C), examples of the organic group having 1 to 30 carbon atoms of R ₃ ′ include organic groups having 1 to 30 carbon atoms of R ₁ ′ and R ₂ ′ in the general formula (A) or (B). The same as the group can be mentioned. Further, W, X, and n in the general formula (D) have the same meanings as those described for the resin (b1) or (b2). Hereinafter, examples of the (c) acetal compound suitably used in the present invention will be described. In the following specific examples, Me is a methyl group, t-
Bu represents a t-butyl group, and iso-Bu represents an isobutyl group.

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The acetal compound (c), which is an essential component of the present invention, has a solid content of 1 of the polymer (b1) or (b2).
It is preferable that the amount is 0.1 parts by weight or more and less than 100 parts by weight with respect to 00 parts by weight. More preferably, it is 1 part by weight or more and less than 50 parts by weight, and more preferably 2 parts by weight or more and 3 parts by weight or less.
Less than 0 parts by weight. If the amount exceeds 100 parts by weight, the heat resistance of the resist tends to decrease, which is not preferable. If the amount is less than 0.1 part by weight, the effect of the present invention may not be exhibited.

[III] Solvent The composition of the present invention contains a solvent in that the above components are dissolved in a solvent capable of dissolving the components and coated on a support. As the solvent used here, ethylene dichloride, cyclohexanone, cyclopentanone, 2-heptanone, γ-butyrolactone, methyl ethyl ketone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 2-methoxyethyl acetate, ethylene glycol monoethyl ether acetate , Propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether propionate, toluene, ethyl acetate, methyl lactate, ethyl lactate, methyl methoxypropionate, ethyl ethoxypropionate, methyl pyruvate, ethyl pyruvate, pyruvine Propyl acid, N, N-
Dimethylformamide, dimethylsulfoxide, N-methylpyrrolidone, tetrahydrofuran and the like are preferable, and these solvents can be used alone or in combination. In the present invention, as the solvent, propylene glycol monomethyl ether acetate is particularly preferable, and thereby, the in-plane uniformity is improved. The concentration of the solid content (including other additives described below) of the composition of the present invention is generally 0.5 to 20% by weight, preferably 3 to 15% by weight in the solvent. Allow to dissolve.

[IV] Organic Basic Compound The organic basic compound used in the present invention is a compound which is more basic than phenol. Among them, a nitrogen-containing basic compound is preferable. Among them, a nitrogen-containing basic compound having a structure represented by the following formulas (A) to (E) is preferable.

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Further preferred compounds are nitrogen-containing basic compounds having two or more nitrogen atoms having different chemical environments in one molecule, and particularly preferred is a ring structure containing a substituted or unsubstituted amino group and a nitrogen atom. Or a compound having an alkylamino group. Preferred specific examples include substituted or unsubstituted guanidine, substituted or unsubstituted aminopyridine, substituted or unsubstituted aminoalkylpyridine, substituted or unsubstituted aminopyrrolidine, substituted or unsubstituted indazol,
Substituted or unsubstituted pyrazole, substituted or unsubstituted pyrazine, substituted or unsubstituted pyrimidine, substituted or unsubstituted purine, substituted or unsubstituted imidazoline, substituted or unsubstituted pyrazoline, substituted or unsubstituted piperazine, substituted Or, unsubstituted aminomorpholine, substituted or unsubstituted aminoalkylmorpholine and the like can be mentioned. Preferred substituents are an amino group,
An aminoalkyl group, an alkylamino group, an aminoaryl group, an arylamino group, an alkyl group, an alkoxy group, an acyl group, an acyloxy group, an aryl group, an aryloxy group, a nitro group, a hydroxyl group, and a cyano group.

As particularly preferred compounds, guanidine and
1,1-dimethylguanidine, 1,1,3,3-tetramethylguanidine, imidazole, 2-methylimidazole, 4-methylimidazole, N-methylimidazole, 2-phenylimidazole, 4,5-diphenylimidazole, , 4,5-triphenylimidazole, 2-aminopyridine, 3-aminopyridine, 4-aminopyridine, 2-dimethylaminopyridine, 4-dimethylaminopyridine, 2-diethylaminopyridine,
-(Aminomethyl) pyridine, 2-amino-3-methylpyridine, 2-amino-4-methylpyridine, 2-amino-5-methylpyridine, 2-amino-6-methylpyridine, 3-aminoethylpyridine, -Aminoethylpyridine, 3-aminopyrrolidine, piperazine, N- (2
-Aminoethyl) piperazine, N- (2-aminoethyl) piperidine, 4-amino-2,2,6,6-tetramethylpiperidine, 4-piperidinopiperidine, 2-iminopiperidine, 1- (2-amino Ethyl) pyrrolidine, pyrazole, 3-amino-5-methylpyrazole,
5-amino-3-methyl-1-p-tolylpyrazole,
Pyrazine, 2- (aminomethyl) -5-methylpyrazine, pyrimidine, 2,4-diaminopyrimidine, 4,6
-Dihydroxypyrimidine, 2-pyrazoline, 3-pyrazoline, N-aminomorpholine, N- (2-aminoethyl) morpholine, diazabicyclononene, diazabicycloundecene, and the like, but are not limited thereto. is not.

These organic basic compounds can be used alone or in combination of two or more. The amount of the organic basic compound to be used is generally 0.04 to the compound (a) of the present invention which generates an acid upon irradiation with an electron beam or X-ray.
It is 1 to 10 mol%, preferably 0.1 to 5 mol%.
If it is less than 0.01 mol%, the effect of the addition cannot be obtained.
On the other hand, if it exceeds 10 mol%, the sensitivity tends to decrease and the developability of the unexposed portion tends to deteriorate.

[V] Fluorine and / or Silicon Surfactant The surfactant that can be used in the positive photoresist composition of the present invention is preferably a fluorine and / or silicon surfactant. Any of a surfactant, a silicon surfactant, and a surfactant containing both a fluorine atom and a silicon atom, or two or more thereof can be contained. As these surfactants, for example, JP-A-62-3
6663, 61-226746, 61-226745, 62-170950
No., 63-34540, JP-A-7-230165, 8-62834,
No. 9-54432, No. 9-5988, U.S. Pat.No. 5405720, No. 5360
692, 5529881, 5296330, 5436098, 55
The surfactants described in Nos. 76143, 5294511 and 5824451 can be used, and the following commercially available surfactants can be used as they are. Examples of commercially available surfactants that can be used include, for example, F-Top EF301, EF303, (manufactured by Shin-Akita Kasei Co., Ltd.), Florard FC430, 431 (manufactured by Sumitomo 3M Limited), Megafac F171, F173, F176, F189, R0.
8 (Dai Nippon Ink Co., Ltd.), Surflon S-382, SC10
1, 102, 103, 104, 105, and 106 (manufactured by Asahi Glass Co., Ltd.) and Troisol S-366 (manufactured by Troy Chemical Co., Ltd.). Also, polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) can be used as a silicon-based surfactant.

A surfactant other than the fluorine-based and / or silicon-based surfactant may be used in combination. Specifically, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, polyoxyethylene alkyl ethers such as polyoxyethylene oleyl ether, polyoxyethylene octyl phenol ether, polyoxyethylene nonyl phenol ether and the like Sorbitan such as polyoxyethylene alkyl allyl ethers, polyoxyethylene / polyoxypropylene block copolymers, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, sorbitan tristearate Fatty acid esters, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopal Nonionic surfactants such as polyoxyethylene sorbitan fatty acid esters such as polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, and polyoxyethylene sorbitan tristearate; acrylic or methacrylic acid (Co) polymerized polyflow no. 75, no. 9
5 (manufactured by Kyoeisha Yushi Kagaku Kogyo KK) and the like.

The amount of these surfactants is usually 2% by weight or less, preferably 1% by weight or less, based on the solid content of the whole composition in the composition of the present invention. These surfactants may be added alone or in combination of two or more.

In pursuit of further advances in semiconductors, in addition to the essential performance of the resist such as high resolution, sensitivity, applicability, minimum application amount, adhesion to the substrate, heat resistance, and preservation of the composition From various viewpoints such as stability, a high-performance composition is required. Recently, there has been a tendency to create devices using large diameter wafers in order to increase the absolute amount of chips that can be obtained. However, if the coating is applied to a large diameter, there is a concern that the coating properties, particularly the in-plane film thickness uniformity, may be reduced. Therefore, it is required to improve the film thickness in-plane uniformity for a large diameter wafer. As a method for confirming the uniformity, the film thickness is measured at many points in the wafer, the standard deviation of each measured value is obtained, and the uniformity can be confirmed by a value three times the standard deviation. It can be said that the smaller this value is, the higher the in-plane uniformity is. As the value, a value three times the standard deviation is preferably 100 or less, more preferably 50 or less.
CD linearity is regarded as the most important factor in the production of photolithography masks, and there is a demand for improved uniformity of the film thickness within a blank.

The resist composition of the present invention can be dissolved in a solvent and then filtered. The filter used for that purpose is selected from those used in the resist field, and specifically, the material of the filter is polyethylene,
Those containing nylon or polysulfone are used. More specifically, micro guard manufactured by Millipore,
Microguard Plus, Microguard Minichem-
D, Microgard Minichem-D PR, Millipore Obturizer DEV / DEV-C, Millipore Obturizer 16/14, Ultibore N66 manufactured by Pall, Posidyne, Nylon Falcon and the like. The pore diameter of the filter can be the one confirmed by the following method. In other words, PSL standard particles (polystyrene latex beads, particle size 0.100 μm) in ultrapure water
Is dispersed and continuously flowed at a constant flow rate to the primary side of the filter by a tube pump, and the challenge concentration is measured by a particle counter. Those that can capture 90% or more can be used as a 0.1 μm pore size filter.

The positive electron beam or X-ray resist composition of the present invention is applied to a substrate (for example, silicon / silicon dioxide coating) or a substrate for producing a mask for photolithography (for example: A good resist pattern can be obtained by applying a suitable coating method such as a spinner, a coater or the like onto a (glass / Cr coating), exposing through a predetermined mask, baking and developing.

Examples of the developing solution of the composition of the present invention include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia, and ethylamine and n-propylamine. Monoamines, secondary amines such as diethylamine and di-n-butylamine, tertiary amines such as triethylamine and methyldiethylamine, alcoholamines such as dimethylethanolamine and triethanolamine, tetramethylammonium hydroxide, tetraethylammonium An alkaline aqueous solution such as a quaternary ammonium salt such as hydroxide, or a cyclic amine such as pyrrole or piperidine can be used. Further, an appropriate amount of an alcohol or a surfactant may be added to the above alkaline aqueous solution.

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EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the contents of the present invention are not limited thereto.

1. Example of synthesis of constituent materials (1) Compound that generates an acid by electron beam or X-ray (1-1) Synthesis of tetramethylammonium pentafluorobenzenesulfonate Dissolve 25 g of pentafluorobenzenesulfonyl chloride in 100 ml of methanol under ice cooling. Then, 100 g of a 25% aqueous solution of tetramethylammonium hydroxide was slowly added thereto. After stirring at room temperature for 3 hours, a solution of tetramethylammonium pentafluorobenzenesulfonate was obtained. This solution was used for salt exchange with sulfonium salt and iodonium salt.

(1-2) Synthesis of triphenylsulfonium pentafluorobenzenesulfonate 50 g of diphenylsulfoxide was dissolved in 800 ml of benzene, and 200 g of aluminum chloride was added thereto.
Refluxed for 4 hours. The reaction solution was slowly poured into 2 L of ice, and 400 ml of concentrated hydrochloric acid was added thereto, followed by heating at 70 ° C. for 10 minutes. This aqueous solution was washed with 500 ml of ethyl acetate, filtered, and then a solution prepared by dissolving 200 g of ammonium iodide in 400 ml of water was added. The precipitated powder was collected by filtration, washed with water, washed with ethyl acetate and dried to obtain 70 g of triphenylsulfonium iodide. Triphenylsulfonium iodide (30.5 g) was dissolved in methanol (1000 ml), and silver oxide (19.1 g) was added to the solution.
Stirred for hours. The solution was filtered, and an excess amount of a solution of tetramethylammonium pentafluorobenzenesulfonate was added thereto. The reaction solution was concentrated, dissolved in 500 ml of dichloromethane, and the solution was washed with a 5% aqueous solution of tetramethylammonium hydroxide and water. The organic phase was dried over anhydrous sodium sulfate and concentrated to obtain triphenylsulfonium pentafluorobenzenesulfonate (I-1).

(1-3) di (4-t-amylphenyl)
Synthesis of iodonium pentafluorobenzenesulfonate 60 g t-amylbenzene, 39.5 potassium iodate
g, 81 g of acetic anhydride, and 170 ml of dichloromethane were mixed, and 66.8 g of concentrated sulfuric acid was slowly added dropwise thereto under ice cooling. After stirring for 2 hours under ice cooling, the mixture was stirred at room temperature for 10 hours. To the reaction mixture was added 500 ml of water under ice-cooling, and the mixture was extracted with dichloromethane. The organic phase was washed with sodium hydrogen carbonate and water, and concentrated to obtain di (4-t-amylphenyl) iodonium sulfate. This sulfate was added to a solution of an excess amount of tetramethylammonium pentafluorobenzenesulfonate. 500 ml of water was added to this solution, and this was extracted with dichloromethane. The organic phase was washed with a 5% aqueous solution of tetramethylammonium hydroxide and water, and concentrated to obtain di (4-t-amylphenyl) iodonium pentafluorobenzenesulfonate (III −
1) was obtained. Other acid generators can be synthesized using the same method as described above.

(2) Synthesis of Resin (Synthesis Example 1) Synthesis of Vinyl Ether 1 25 g of 4-methoxy-1-naphthol and 22.9 g of chloroethyl vinyl ether were dissolved in 140 ml of DMAc, and 6.90 g of NaOH was added. Stir for 2 hours. Thereafter, the NaCl salt was filtered, and ethyl acetate and water were added to carry out liquid separation. Thereafter, ethyl acetate was distilled off from the organic layer and recrystallized from methanol to obtain vinyl ether 1 in a yield of 84%.

(Synthesis Examples 2 to 14) Vinyl ethers 2-1
Synthesis of 4 Reaction was carried out in the same manner as in Synthesis Example 1 except that the alcohol to be added was changed, and vinyl ethers 2 to 14 were obtained by silica gel column chromatography or methanol recrystallization.

(Synthesis Example 15) Synthesis of vinyl ether 15 In a dried flask, 25 g of 9-hydroxymethylanthracene was dissolved in 100 ml of anhydrous THF, and cooled to 0 ° C under a nitrogen stream. 3.17 g of sodium hydride
Was added and stirred for a while. Thereafter, 19.2 g of chloroethyl vinyl ether was added dropwise at 0 ° C, and after completion of the addition, the mixture was stirred at room temperature for 2 hours. After adding a saturated aqueous solution of ammonium chloride, ethyl acetate and water were added to carry out liquid separation. Thereafter, the solvent was distilled off from the organic layer, and the residue was purified by silica gel column chromatography to obtain vinyl ether 15 in a yield of 88%.
I got it.

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(Synthesis Example 16) Synthesis of Resin 1 Poly (p-hydroxystyrene) manufactured by Nippon Soda Co., Ltd.
50 g of (VP-8000) was dissolved in 200 g of anhydrous THF, 15.25 g of vinyl ether 1 and 80 mg of p-toluenesulfonic acid were added, and the mixture was stirred at room temperature for 18 hours. The reaction solution was dripped into 5 L of ultrapure water with vigorous stirring to reprecipitate. The obtained resin is placed in a vacuum dryer at 70 ° C. for 12 hours.
After drying for an hour, Resin 1 was obtained. The weight average molecular weight of VP-8000 was 9,800 using GPC measurement polystyrene as a standard sample.

(Synthesis Examples 17 to 30) Resins 2 to 15 were obtained in the same manner as in Synthesis Example 16 except that vinyl ether was added.

The resins synthesized above are shown below.

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(Synthesis Example 31) Poly (p-hydroxystyrene) 70 g, manufactured by Nippon Soda Co., Ltd. (molecular weight: 8,000)
To propylene glycol methyl ether acetate (P
(GMEA), and 0.35 g of pyridinium p-toluenesulfonate was added thereto and dissolved by heating at 60 ° C. The mixture was reduced in pressure to 60 mm and 20 mmHg, and about 40 g of the solvent was distilled off together with the water remaining in the system. After cooling to 20 ° C, alcohol (alcho
l) (1) 44.1 g was added and dissolved. Then tert
17.5 g of butyl vinyl ether was added and
Stirring was continued at 0 ° C. 280 m of ethyl acetate was added to the reaction mixture.
l, and 140 ml of water and 12 ml of acetone were further added to perform an extraction operation. After repeating the water washing operation three times, distillation was carried out at 60 ° C. and 20 mmHg to remove water in the system. Further dilute the obtained resin solution with acetone,
A white resin was obtained by precipitation in a large amount of hexane.
This operation was repeated three times, and the obtained resin was dried by heating at 40 ° C. for 24 hours in a vacuum dryer to obtain [Resin 16] having the following structure. The weight average molecular weight was 8,400.

(Synthesis Example 32) to (Synthesis Example 39) The alcohols to be added were alcohols (2) to
The reaction was carried out in the same manner as in Synthesis Example 31 except for changing to (8), thereby obtaining Resins 17 to 23.

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The Ip value of the HO-X-corresponding portion in the formula (I) of the above resin is as follows. O
xford Molecular, software-CAChe4.1.1 M
Calculated using OPAC (PM3 parameters). (Unit: eV) Resin 1: 8.237 Resin 2: 8.717 Resin 3: 8.783 Resin 4: 8.505 Resin 5: 8.543 Resin 6: 8.469 Resin 7: 8.293 Resin 8: 8.722 Resin 9: 8.715 Resin 10: 8.477 Resin 11: 7.698 Resin 12: 8.029 Resin 13: 8.500 Resin 14: 8.109 Resin 15: 8.015 Resin 16: 8. 588 Resin 17: 8.608 Resin 18: 8.739 Resin 19: 8.413 Resin 20: 8.746 Resin 21: 8.109 Resin 22: 8.851 Resin 23: 8.182 Comparative resin 24:10. 890 (calculation target compound ethanol)

The ratio of the repeating unit having a leaving group and the weight average molecular weight of each resin are shown below.

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[Table 1]

(Synthesis Example 40) Benzyl alcohol 5
4.1 g and 0.4 g of p-toluenesulfonic acid were added to PG
It was dissolved in 230 g of MEA, and distilled under reduced pressure at 60 ° C. and 20 mmHg to remove water in the system. The fraction is about 18
g. After cooling to 20 ° C., 50.1 g of tert-butyl vinyl ether was added and stirred for 1 hour. After adding 0.4 g of triethylamine to the reaction mixture and stirring, 200 ml of ethyl acetate was added, and 100 ml of ethyl acetate was added.
And extracted with water. After repeating this washing step three times, the ethyl acetate was distilled off under reduced pressure, and the acetal compound A-
A mixture of 1 and A-2 was obtained. This mixture was isolated by silica gel column chromatography.

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(Synthesis Example 41) Acetal compounds A-3 to A-12 were obtained in the same manner as in Synthesis Example 40 using the following alcohol compounds instead of benzyl alcohol.

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[Table 2]

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2. Examples [Examples 1 to 23 and Comparative Examples 1 and 2] (1) Coating of resist Resin 1 (12 g), acid generator (I-1) (0.11
g), nitrogen-containing basic compound B-1 (0.0065 g),
Surfactant W-1 (0.0022 g) and acetal compound (A-9) (addition amounts described in Table 3) were dissolved in 19.5 g of propylene glycol monomethyl ether acetate, and 0.1 μm of Teflon (registered) (Trademark) filter to prepare a resist solution of Example 1. Similarly, the resist solutions of Examples 2 to 23 and Comparative Examples 1 and 2 were prepared by changing the type of each component as shown in Table 3. Each sample solution was applied on a silicon wafer using a spin coater and dried on a vacuum suction type hot plate at 120 ° C. for 90 seconds to obtain a 0.5 μm-thick resist film.

(2) Preparation of resist pattern An electron beam lithography system (pressing voltage 50 KV) is applied to this resist film.
Irradiation was performed using After the irradiation, each was heated on a vacuum adsorption type hot plate (at 110 ° C. for 60 seconds), and 2.
It was immersed in a 38% aqueous solution of tetramethylammonium hydroxide (TMAH) for 60 seconds, rinsed with water for 30 seconds, and dried. The cross-sectional shapes of the obtained contact hole pattern and line and space pattern were observed with a scanning electron microscope.

(3) Evaluation of sensitivity and resolution The sensitivity was 0.20 μm line (line: space = 1:
The minimum dose at the time of resolving 1) was defined as sensitivity, and the limit resolution at that dose (line and space were separated and resolved) was defined as resolution. For a line in which a 0.20 μm line (line: space = 1: 1) was not resolved, the limit resolution was defined as the resolution, and the dose at that time was defined as the sensitivity.

Evaluation of Line Width at Pattern Top and Bottom The line width of a 0.2 μm line (line: space = 1: 1) was observed at the top (top) and bottom (bottom) with a scanning electron microscope. Evaluation was made based on the difference in bottom line width. 0.2 μm line (line: space = 1:
For those which did not resolve 1), the line width at the limit resolution was evaluated. ◎: Difference in line width between top and bottom is less than 3% (% of line width in bottom) ○: Difference in line width between top and bottom is less than 5% (% relative to line width in bottom) ×: The difference between the line width of the top part and the bottom part is 5% or more (% of the line width of the bottom part).

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[Table 3]

The abbreviations used in Table 3 indicate the following.

The basic organic compounds are as follows. B-1: 2,4,5-triphenylimidazole B-2: 1,5-diazabicyclo [4.3.0] nona
5-ene B-3: 4-dimethylaminopyridine B-4: 1,8-diazabicyclo [5.4.0] undec-7-ene B-5: N-cyclohexyl-N'-morpholinoethylthiourea

The surfactant is as follows. W-1: Troysol S-366 (Troy Chemical Co., Ltd.)
W-2: Megafac F176 (Dainippon Ink Co., Ltd.)
W-3: Megafac R08 (Dai Nippon Ink Co., Ltd.) W-4: Polysiloxane polymer KP-341 (Shin-Etsu Chemical Co., Ltd.) W-5: Surflon S-382 (Asahi Glass Co., Ltd.) Made)

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[Table 4]

From the results shown in Table 4, it can be seen that the positive resist composition of the present invention has high sensitivity and high resolution and a good pattern profile.

In Examples 1 to 23, when the solvent was changed to propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether = 80/20 (weight ratio), the same effect was obtained.

(4) Patterning by 1-X-ray Exposure Using the respective resist compositions of Examples 1 and 20 and Comparative Examples 1 and 2, a film thickness of 0.4 was obtained in the same manner as in (1) above.
A 0 μm resist film was obtained. Next, patterning was performed in the same manner as in the above (2) except that a 1: 1 X-ray exposure apparatus (gap value: 20 nm) was used, and the resist performance was evaluated in the same manner as in the above (3). Table 5 shows the evaluation results.

Table 5 Resist Composition Sensitivity (mJ / cm ² ) Resolution (μm) Top / Photo Line Width Difference Example 1 40 0.09 Example 20 35 0.10 比較 Comparative Example 1 130 0.16 ○ Comparative Example 2 70 0.12 ×

As is evident from Table 5, the resist composition of the present invention shows extremely excellent performance even in X-ray exposure.

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The positive resist composition for electron beam or X-ray of the present invention has high sensitivity and high resolution, and the obtained resist pattern is good.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Koji Shirakawa 4000F, Kawajiri, Yoshida-machi, Haibara-gun, Shizuoka Prefecture F-term in Fujisha Shin Film Co., Ltd. (Reference) 2H025 AA01 AA02 AA03 AB16 AC05 AC06 AD03 BE00 BE07 BG00 CC20 FA03 FA12 FA17 4J100 AB07P BA03P HA43 HC09 HC13 JA38

Claims (6)

[Claims] (1) a compound capable of generating an acid upon irradiation with an electron beam or an X-ray; and (b1) a group capable of leaving by the action of an acid, the ionization potential value of which is smaller than that of p-ethylphenol. And (c) at least one of the acetal compounds represented by the general formula (A) or the general formula (B), which has a residue of a compound having the following formula: A positive resist composition for electron beam or X-ray, comprising: Embedded image In the formula (A) or (B), R ₁ ′ and R ₂ ′ each independently represent an organic group having 1 to 30 carbon atoms. 2. The (b1) resin is an acid-catalyzed reaction of an alkali-soluble polymer having a hydroxyl group with a vinyl ether compound represented by the following general formula (C) and an alcohol compound represented by the following general formula (D). The electron beam or X according to claim 1, wherein the resin is a resin obtained by performing
Positive resist composition for lines. Embedded image In the formula (C), R ₃ ′ represents an organic group having 1 to 30 carbon atoms.
In the formula (D), W represents a divalent organic group. X is an organic group, and the value of the ionization potential (Ip) of HO-X is p
-A group showing a value smaller than the Ip value of ethylphenol. n represents the integer of 0-4. When n is 2 to 4, a plurality of W may be the same or different. (3) a compound which generates an acid upon irradiation with an electron beam or X-ray; (b2) a compound having a repeating unit represented by the formula (I); And (c) an acetal compound represented by the general formula (A) or the general formula (B) according to claim 1. Resist composition. Embedded image In the formula (I), R ¹ represents a hydrogen atom or a methyl group. R ²
And R ³ each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. W, X and n are as defined above. 4. The positive resist composition for an electron beam or X-ray according to claim 2, wherein X is represented by the formula (II). -LY (II) In the formula (II), L represents a single bond or an alkylene group. Y is Represents a group selected from the group of R ⁴ represents a linear or branched alkyl group having 1 to 6 carbon atoms independently. n1 is 0
An integer of 3, n2 is an integer of 0 to 7, n3 is an integer of 0 to 9,
n4 represents an integer of 0 to 9, and n5 represents an integer of 0 to 9. 5. The total amount of the acetal compound (c) is:
The electron beam or X-ray according to any one of claims 1 to 4, wherein the amount of the electron beam or the X-ray is 0.1 to less than 100 parts by weight based on the total weight of the polymer (b1) or (b2). Positive resist composition. 6. The compound (a) which generates an acid upon irradiation with an electron beam or X-ray contains at least one of the compounds represented by any of formulas (I ′) to (III ′). The positive resist composition for electron beams or X-rays according to claim 1, wherein Embedded image In the formula, R _{1 to} R ₃₇ are the same or different and each represents a hydrogen atom, a linear, branched or cyclic alkyl group, a linear, branched or cyclic alkoxy group, a hydroxyl group, a halogen atom, or -S- Represents an _R38 group. R ₃₈ represents a linear, branched or cyclic alkyl group or aryl group. Further, two or more of R _{1 to} R ₁₅ , R _{16 to} R ₂₇ , and R _{28 to} R ₃₇ are combined to form one or two kinds selected from a single bond, carbon, oxygen, sulfur, and nitrogen. A ring including the above may be formed. X ^- represents a sulfonic acid anion.