JP2002341523A - Positive resist composition for electron beam or x-ray - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a positive resist composition for electron beams or X-rays having high sensitivity, high resolution and excellent edge roughness of a line pattern. SOLUTION: The positive photoresist composition contains (a) a specified compound which generates an acid when irradiated with electron beams or X-rays, (b) a resin having the residue of a compound having a lower 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 (c) a solvent.

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 electron beams or X-rays, and more particularly to a chemical amplification system for electron beams or X-rays having high sensitivity, high resolution and excellent edge roughness of a line pattern. The present invention relates to a positive resist composition.

[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 satisfy the necessity, the wavelength used in 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 regarded as a next-generation or next-next-generation pattern forming technology, and it is desired to develop positive and negative resist compositions having high sensitivity, high resolution, and excellent line pattern edge roughness. ing. Here, the edge roughness refers to when the pattern is viewed from directly above because the top and bottom edges of the resist line pattern fluctuate irregularly in the direction perpendicular to the line direction due to the characteristics of the resist. Means that the edge looks uneven.

Poly (p-hydroxystyrene) partially protected as a chemically amplified positive resist is disclosed in
-319092, but when applied to lithography using ultraviolet rays or far ultraviolet rays, sensitivity,
Although it is excellent in pattern shape, when it is applied to lithography using an electron beam or X-ray, it has a drawback that it has low sensitivity and particularly deteriorates the edge roughness of a line pattern.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a positive resist composition for electron beams or X-rays which has high sensitivity and high resolution and has excellent edge roughness of a line pattern.

[0006]

As a result of the study, the present inventors have found that (a) a specific acid-generating compound and (b) a group capable of leaving by an acid contain a p-hydroxystyrene unit (p-ethylphenol). ) (Ip: about 8.9)
It has been found that by using a polymer having a structure exhibiting an Ip value lower than eV), a resist having high sensitivity, high resolution, and excellent line pattern edge roughness can be obtained. 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.

(1) (a) a compound represented by any one of formulas (I) to (IV), which generates an acid upon irradiation with an electron beam or X-ray, and (b) desorbed by the action of an acid A resin having a residue of a compound having an ionization potential value (Ip value) smaller than the Ip value of p-ethylphenol in the group, a resin having increased solubility in an alkali developing solution by the action of an acid, and (c) A) positive resist composition for electron beam or X-ray, comprising a solvent.

[0008]

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In the formula (I), Ar ³ and Ar ⁴ each independently represent a substituted or unsubstituted alkyl group, aryl group, aralkyl group or camphor group. In the formula (II), R ²⁰⁶ represents a substituted or unsubstituted alkyl group, aryl group, aralkyl group or camphor group. A represents a substituted or unsubstituted alkylene group, alkenylene group or arylene group.

[0010]

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[0011]

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In the formulas (III) and (IV), R ^o , R
Each independently represents an alkyl group or an aryl group which may have a substituent.

(2) The positive resist composition for electron beam or X-ray according to (1), wherein the resin (b) contains a repeating unit represented by the formula (V).

[0014]

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In the formula (V), R ^1a represents a hydrogen atom or a methyl group. R ^2a and R ^3a each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. W represents a divalent organic group. X _a is an organic group, a group that satisfies the ionization potential value of H-O-X _a is smaller than the ionization potential value of p- ethylphenol. n is 0 to 4
Represents an integer. When n is 2 to 4, a plurality of W may be the same or different.

(3) The compound according to (1) or (2), wherein the compound (a) that generates an acid upon irradiation with an electron beam or X-ray generates an aromatic sulfonic acid. X-ray positive resist composition. (4) The electron beam according to any one of (1) to (3), wherein the compound that generates an acid upon irradiation with an electron beam or X-ray of (a) generates a sulfonic acid containing fluorine. Or a positive resist composition for X-rays. (5) In addition to the compound capable of generating an acid upon irradiation with an electron beam or X-ray of the above (a), the compounds of the formulas (VI) to (VIII)
(1) to (1) to containing a compound which generates an acid upon irradiation with an electron beam or X-ray represented by
The positive resist composition for electron beam or X-ray according to any one of (4).

[0017]

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In the general formulas (VI) to (VIII), R₁~
R₃₇Represents a hydrogen atom, an alkyl group, an alkoxyl group,
Roxyl group, halogen atom, or -SR₃₈Group that can be indicated by
Represents -SR₃₈R in₃₈Is an alkyl group or an aryl
Represents a hydroxyl group. R₁~ R₃₈May be the same or different
It may be. R₁~ R₁₅Is selected from
Two or more are linked directly to each other at the ends, or
Bonds through elements selected from oxygen, sulfur and nitrogen
And may form a ring structure. R₁₆~ R ₂₇in the case of
May also form a ring structure in the same manner. R₂₈~ R
₃₇In this case, a ring structure may be formed in the same manner.
X^-Is an anion of sulfonic acid.

[0019]

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) A compound capable of generating an acid upon irradiation with an electron beam or X-ray (hereinafter also referred to as an acid generator) The acid generator used in the present invention is represented by the general formula (I) Selected from the group consisting of a disulfone derivative represented by the general formula (II), an imidosulfonate derivative represented by the general formula (II), a diazodisulfone derivative represented by the general formula (III), and a diazoketosulfone derivative represented by the general formula (IV) At least one type.

In the formulas (I) and (II), Ar ³ and Ar ⁴ each independently represent a substituted or unsubstituted alkyl group, aryl group, aralkyl group or camphor group. R ²⁰⁶ represents a substituted or unsubstituted alkyl group, aryl group, aralkyl group or camphor group. A represents a substituted or unsubstituted alkylene group, alkenylene group, or arylene group. The alkyl group may be linear, branched, or cyclic. Examples of the linear or branched alkyl group include a methyl group, an ethyl group, a propyl group, an n-butyl group,
Examples thereof include an alkyl group having 1 to 4 carbon atoms, such as a -butyl group and a t-butyl group. Examples of the cyclic alkyl group include a cyclopropyl group, a cyclopentyl group,
Examples thereof include an alkyl group having 3 to 8 carbon atoms such as a cyclohexyl group. The aryl group has 6 to 6 carbon atoms, such as a phenyl group, a tolyl group, a methoxyphenyl group, and a naphthyl group.
There may be mentioned 14 aryl groups. Examples of the aralkyl group include a phenylmethyl group, a phenylethyl group, a naphthylmethyl group, a naphthylethyl group, and an anthrylmethyl group. Examples of the alkylene group and arylene group for A include divalent groups corresponding to the above-described alkyl groups and aryl groups. Examples of the alkenylene group include a vinylene group, a propenylene group, an allylene group, and a butenylene group.

The above-mentioned alkyl group, aryl group, alkylene group, alkenylene group, and arylene group may have a substituent further bonded to a part of the group to increase the number of carbon atoms. You may. The substituent which may be further bonded preferably includes an alkoxy group having 1 to 4 carbon atoms, an aryl group having 6 to 10 carbon atoms, and an alkenyl group having 2 to 6 carbon atoms, Examples include a cyano group, a hydroxy group, a carboxy group, an alkoxycarbonyl group, a nitro group, and the like. In addition, a halogen atom may be used. For example, fluorine atom, chlorine atom,
An iodine atom can be mentioned. The aralkyl group is
An alkyl group having 1 to 10 carbon atoms, an alkoxy group, or an alkoxycarbonyl group may be substituted at any position of the aryl group. Specific examples include the following compounds, but are not limited thereto.

[0023]

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[0024]

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[0029]

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[0030]

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In the general formula (III), R ^o and R are
Each independently represents an alkyl group or an aryl group which may have a substituent. Here, examples of the alkyl group include a linear or branched alkyl group and a cyclic alkyl group. As the linear or branched alkyl group, a linear or branched alkyl group having 1 to 20 carbon atoms is preferable, and a linear or branched alkyl group having 1 to 12 carbon atoms is more preferable. Is preferred. As the cyclic alkyl group, a cyclopentyl group or a cyclohexyl group is preferable. As the aryl group, an aryl group which may have a substituent having 6 to 10 carbon atoms is preferable. Examples of the substituent which the alkyl group or the aryl group represented by ^Ro or R may have include, for example, an alkoxy group (preferably having 1 to 4 carbon atoms, for example,
A methoxy group, an ethoxy group, a propoxy group, a butoxy group), an aryl group (preferably having 6 to 14 carbon atoms, for example, a phenyl group or a naphthyl group), an alkoxycarbonyl group (preferably having 1 to 5 carbon atoms), a halogen atom, and a nitro group , Acetyl group and the like. Further, with respect to the aryl group as R ^o or R, further as an example of a substituent,
An alkyl group (preferably having 1 to 12 carbon atoms, for example, a methyl group, an ethyl group, an n-propyl group, an i-propyl group,
n-butyl, i-butyl, s-butyl, t-butyl, n-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, nonyl, decyl, dodecyl) Can be mentioned.

Specific examples of the diazodisulfone derivative compound represented by the general formula (III) include the following compounds. Bis (methylsulfonyl) diazomethane, bis (ethylsulfonyl) diazomethane, bis (propylsulfonyl) diazomethane, bis (1-methylpropylsulfonyl) diazomethane, bis (butylsulfonyl)
Diazomethane, bis (1-methylbutylsulfonyl) diazomethane, bis (heptylsulfonyl) diazomethane, bis (octylsulfonyl) diazomethane, bis (nonylsulfonyl) diazomethane, bis (decylsulfonyl) diazomethane, bis (dodecylsulfonyl) diazomethane, bis (tri Fluoromethylsulfonyl) diazomethane, bis (cyclohexylsulfonyl) diazomethane, bis (benzylsulfonyl) diazomethane, bis (2-chlorobenzylsulfonyl) diazomethane, bis (4-chlorobenzylsulfonyl) diazomethane, bis (phenylsulfonyl) diazomethane, bis (4 -Methoxyphenylsulfonyl) diazomethane, bis (2-
Methylphenylsulfonyl) diazomethane, bis (3-
Methylphenylsulfonyl) diazomethane, bis (4-
Methylphenylsulfonyl) diazomethane, bis (2,
4-dimethylphenylsulfonyl) diazomethane, bis (2,5-dimethylphenylsulfonyl) diazomethane, bis (3,4-dimethylphenylsulfonyl) diazomethane, bis (2,4,6-trimethylphenylsulfonyl) diazomethane, bis (4- Fluorophenylsulfonyl) diazomethane, bis (2,4-difluorophenylsulfonyl) diazomethane, bis (2,4,6-
Trifluorophenylsulfonyl) diazomethane, bis (4-nitrophenylsulfonyl) diazomethane.

In the general formula (IV), R ^o and R have the same meanings as those in the general formula (III). Specific examples of the diazoketosulfone derivative compound include the following compounds.

Methylsulfonyl-benzoyldiazomethane, ethylsulfonyl-benzoyldiazomethane,
Methylsulfonyl-4-bromobenzoyldiazomethane, ethylsulfonyl-4-bromobenzoyldiazomethane, phenylsulfonyl-benzoyldiazomethane, phenylsulfonyl-2-methylbenzoyldiazomethane, phenylsulfonyl-3-methylbenzoyldiazomethane, phenylsulfonyl- 4-methylbenzoyldiazomethane, phenylsulfonyl-3-methoxybenzoyldiazomethane, phenylsulfonyl-4-methoxybenzoyldiazomethane, phenylsulfonyl-3-chlorobenzoyldiazomethane, phenylsulfonyl-4-chlorobenzoyldiazomethane,
Tolylsulfonyl-3-chlorobenzoyldiazomethane, tolylsulfonyl-4-chlorobenzoyldiazomethane, phenylsulfonyl-4-fluorobenzoyldiazomethane, tolylsulfonyl-4-fluorobenzoyldiazomethane.

The disulfone derivative represented by the general formula (I) is prepared by reacting a sulfonyl chloride compound with hydrazine in a suitable solvent such as pyridine or tetrahydrofuran under basic conditions to synthesize a symmetric or asymmetric bissulfonylhydrazine. This can be obtained by performing denitrification using concentrated nitric acid. The imide sulfonate derivative represented by the general formula (II) can be synthesized by reacting N-hydroxyimide and the corresponding sulfonic acid chloride in a suitable solvent under basic conditions.
The diazodisulfone derivative represented by the general formula (III) and the diazoketosulfone derivative represented by the general formula (IV) can be synthesized by a synthesis method disclosed in JP-A-5-249682.

In the present invention, the above general formulas (I) to (I)
The compounds represented by (IV) may be used alone or in combination of two or more. In the present invention, the above general formulas (I) to (I)
It is preferable to use the acid generators represented by the general formulas (VI) to (VIII) together with at least one of the compounds represented by (IV). Thereby, the effect of the present invention becomes more remarkable. R _{1 to} R ₃₇ in the general formulas (VI) to (VIII) represent a hydrogen atom, an alkyl group, an alkoxy group, a hydroxyl group, a halogen atom, or a group represented by —SR _38. . R ₁ ~
The alkyl group represented by R ₃₇ may be linear, branched, or cyclic. Examples of the linear or branched alkyl group include a methyl group, an ethyl group, a propyl group, and an n-
Examples thereof include an alkyl group having 1 to 4 carbon atoms, such as a butyl group, a sec-butyl group, and a t-butyl group.
Examples of the cyclic alkyl group include an alkyl group having 3 to 8 carbon atoms such as a cyclopropyl group, a cyclopentyl group, and a cyclohexyl group. The alkoxy group represented by R _{1 to} R ₃₇ may be linear, branched, or a cyclic alkoxy group. Examples of the linear or branched alkoxy group include those having 1 to 8 carbon atoms, such as methoxy, ethoxy, hydroxyethoxy, propoxy, n-butoxy, isobutoxy, sec-butoxy, and t-butoxy. And octyloxy groups. Examples of the cyclic alkoxy group include a cyclopentyloxy group and a cyclohexyloxy group.

As the halogen atom represented by R _{1 to} R ₃₇ ,
Examples include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. R ₃₈ in -S-R ₃₈ in which R ₁ to R ₃₇ represents the
It is an alkyl group or an aryl group. The scope of the alkyl group R ₃₈ is represented can also include any example in the alkyl groups already listed as an alkyl group represented by R ₁ to R _37. The aryl group represented by R ₃₈ is a phenyl group,
Examples thereof include aryl groups having 6 to 14 carbon atoms, such as a tolyl group, a methoxyphenyl group, and a naphthyl group. R ₁
To R ₃₈ is an alkyl group represented below, to aryl groups are both bonded to a substituent in a part of the groups may have to increase the number of carbon atoms, may not have a substituent. The substituent which may be further bonded preferably has 1 carbon atom.
Examples thereof include an alkoxy group having 4 to 4 carbon atoms, an aryl group having 6 to 10 carbon atoms, and an alkenyl group having 2 to 6 carbon atoms, and also include a cyano group, a hydroxy group, a carboxy group, an alkoxycarbonyl group, and a nitro group. be able to. In addition, a halogen atom may be used. For example, a fluorine atom,
A chlorine atom and an iodine atom can be exemplified.

Two or more of the groups represented by R _{1 to} R ₁₅ in formula (VI) may be bonded to form a ring. The ring may be formed by directly bonding the terminals of the groups represented by R _{1 to} R ₁₅ . They may be indirectly linked via one or more elements selected from carbon, oxygen, sulfur and nitrogen to form a ring. 2 of R _{1 to} R ₁₅
As a ring structure formed by bonding two or more, a furan ring,
The same structure as the ring structure found in a dihydrofuran ring, a pyran ring, a trihydropyran ring, a thiophene ring, a pyrrole ring, and the like can be given. R ₁₆ in the general formula (VII)
It is possible to say that the same applies to the ~R _27. Two or more may be directly or indirectly linked to form a ring. The same applies to R _{28 to} R ₃₇ in the general formula (VIII). General formulas (VI) to (VIII) have X ⁻ . X ⁻ in the general formulas (VI) to (VIII) is a sulfonic acid anion. The sulfonic acid forming the anion is preferably a sulfonic acid selected from benzenesulfonic acid, naphthalenesulfonic acid, and anthracenesulfonic acid. More preferably, the sulfonic acid is substituted with one or more fluorine atoms. Or the acid is, together with or in place of the fluorine atom, an alkyl group, an alkoxyl group, an acyl group, an acyloxyl group, a sulfonyl group, a sulfonyloxy group, a sulfonylamino group, an aryl group, an aralkyl group, and an alkoxycarbonyl group. It has at least one organic group selected from the group, and the organic group may further substitute at least one fluorine atom. Further, the above benzenesulfonic acid, naphthalenesulfonic acid, or anthracenesulfonic acid may be substituted with a halogen atom other than fluorine, a hydroxyl group, a nitro group, or the like.

[0039] X ^- alkyl group bonding such as benzenesulfonic acid to form the anion of, for example, a carbon number 1 to 1
2 alkyl groups. The alkyl group may be linear, branched, or cyclic. At least one fluorine atom, preferably 25 or less, is substituted. Specifically, a trifluoromethyl group, a pentafluoroethyl group, a 2,2,2-trifluoroethyl group, a heptafluoropropyl group, a heptafluoroisopropyl group, a perfluorobutyl group, a perfluorooctyl group, a perfluorododecyl group, Perfluorocyclohexyl group and the like can be mentioned. Among them, carbon atoms all substituted with fluorine 1
~ 4 perfluoroalkyl groups are preferred. The above-mentioned alkoxy group bonded to benzenesulfonic acid or the like together with the alkyl group or alone is an alkoxy group having 1 to 12 carbon atoms. The alkoxy group may be linear, branched, or cyclic. At least one fluorine atom, preferably 25 or less, is substituted. Specific examples include a trifluoromethoxy group, a pentafluoroethoxy group, a heptafluoroisopropyloxy group, a perfluorobutoxy group, a perfluorooctyloxy group, a perfluorododecyloxy group, and a perfluorocyclohexyloxy group. Among them, a perfluoroalkoxy group having 1 to 4 carbon atoms, all of which is substituted by fluorine, is preferable. The acyl group bonded to benzenesulfonic acid or the like together with the alkyl group or alone has 2 to 2 carbon atoms.
Those substituted with 12, 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 bonded to benzenesulfonic acid or the like together with the alkyl group or alone is preferably substituted with a fluorine atom having 2 to 12 or 1 to 23 carbon atoms. Specific examples include a trifluoroacetoxy group, a fluoroacetoxy group, a pentafluoropropionyloxy group, and a pentafluorobenzoyloxy group. As the sulfonyl group bonded to benzenesulfonic acid or the like together with the alkyl group or alone, a sulfonyl group having 1 to 12 carbon atoms and substituted with 1 to 25 fluorine atoms is preferable. Specific examples include a trifluoromethanesulfonyl group, a pentafluoroethanesulfonyl group, a perfluorobutanesulfonyl group, a perfluorooctanesulfonyl group, a pentafluorobenzenesulfonyl group, and a 4-trifluoromethylbenzenesulfonyl group. As the above-mentioned sulfonyloxy group bonded to the above-mentioned benzenesulfonic acid or the like together with an alkyl group or alone, a group substituted with a fluorine atom having 1 to 12 or 1 to 25 carbon atoms is preferable. Specific examples include a trifluoromethanesulfonyloxy group, a perfluorobutanesulfonyloxy group, and a 4-trifluoromethylbenzenesulfonyloxy group. The sulfonylamino group bonded to the above-mentioned benzenesulfonic acid or the like together with the alkyl group or alone has 1 to 12 carbon atoms.
Wherein those substituted with 1 to 25 fluorine atoms are preferred. Specific examples include a trifluoromethanesulfonylamino group, a perfluorobutanesulfonylamino group, a perfluorooctanesulfonylamino group, and a pentafluorobenzenesulfonylamino group.

The aryl group bonded to the above-mentioned benzenesulfonic acid or the like together with the alkyl group or alone is preferably one having 6 to 14 carbon atoms and 1 to 9 fluorine atoms. Specific examples include a pentafluorophenyl group, a 4-trifluoromethylphenyl group, a heptafluoronaphthyl group, a nonafluoroanthranyl group, a 4-fluorophenyl group, and a 2,4-difluorophenyl group. The aralkyl group bonded to the above-mentioned benzenesulfonic acid or the like together with the alkyl group or alone is preferably a group substituted by a fluorine atom having 7 to 10 or 1 to 15 carbon atoms. Specific examples include a pentafluorophenylmethyl group, a pentafluorophenylethyl group, a perfluorobenzyl group, a perfluorophenethyl group, and the like. The alkoxycarbonyl group bonded to the benzenesulfonic acid or the like alone or together with the alkyl group may have 2 to 13, 1 to 1 carbon atoms.
Those substituted with 25 fluorine atoms are preferred.
Specific examples include a trifluoromethoxycarbonyl group, a pentafluoroethoxycarbonyl group, a pentafluorophenoxycarbonyl group, a perfluorobutoxycarbonyl group, and a perfluorooctyloxycarbonyl group.

Among these anions, the most preferred X ^- is a fluorine-substituted benzenesulfonic acid anion,
Among them, pentafluorobenzenesulfonic acid anion is particularly preferred. Further, the benzene sulfonic acid, naphthalene sulfonic acid, or anthracene sulfonic acid having the fluorine-containing substituent further has 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. Hereinafter, specific examples of the compounds represented by the general formulas (VI) to (VIII) are shown, but the invention is not limited thereto.

[0043]

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[0048]

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[0049]

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[0055]

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The compounds of the general formulas (VI) and (VII) can be synthesized by the following method. For example, an aryl Grignard reagent such as aryl magnesium bromide is reacted with phenylsulfoxide, and the resulting triarylsulfonium halide is subjected to salt exchange with the corresponding sulfonic acid. There is another way. For example, condensation of phenylsulfoxide and the corresponding aromatic compound using an acid catalyst such as methanesulfonic acid / diphosphorus pentoxide or aluminum chloride,
There is a method of salt exchange. Further, the diaryl iodonium salt and the diaryl sulfide can be synthesized by a method of condensation or salt exchange using a catalyst such as copper acetate. In any of the above methods, the phenylsulfoxide may have a substituent substituted on the benzene ring, or may not have such a substituent. The compound of the general formula (VIII) can be synthesized by reacting an aromatic compound with periodate.

The total content of the compounds represented by the general formulas (I) to (IV) in the resist composition is suitably from 0.1 to 20% by weight based on the solid content of all the positive resist compositions. , Preferably 0.2 to 15% by weight, more preferably 0.5 to 12% by weight. When a compound represented by any of the general formulas (VI) to (VIII) is contained, the content thereof is based on the solid content of the entire positive resist composition.
0.1 to 10% by weight is suitable, preferably 0.2 to 10% by weight.
It is 8% by weight, more preferably 0.5 to 6% by weight.

(Other Acid Generators) In the present invention, the compounds represented by the general formulas (I) to (IV),
In addition to the compounds represented by I) to general formula (VIII),
Other compounds that generate an acid can be used. When using another compound which decomposes upon irradiation with an electron beam or X-ray to generate an acid, the compound represented by the general formulas (I) to (IV) and preferably the general formulas (VI) to The molar ratio of the total of the compounds represented by the formula (VIII) to the other compound that generates an acid is 100/0 to 2
0/80, preferably 90/10 to 40/60, more preferably 80/20 to 50/50. Examples of such other acid generators include photoinitiators for photocationic polymerization, photoinitiators for photoradical polymerization, photodecolorants for dyes, photochromic agents,
Alternatively, a known compound that generates an acid by light and a mixture thereof, which is used for a micro resist or the like, can be appropriately selected and used. For example, diazonium salts, phosphonium salts, iodonium salts, sulfonium salts, selenonium salts, onium salts such as arsonium salts,
Organic halogen compound, organic metal / organic halide, o
-Photoacid generators having a nitrobenzyl-type protecting group, compounds that generate sulfonic acid upon photolysis, such as iminosulfonate, and disulfone compounds.

Further, a group that generates an acid by these lights,
Alternatively, a compound having a compound introduced into the main chain or side chain of a polymer, for example, JP-A-63-26653, JP-A-55-164824, JP-A-62-69263, JP-A-63-14638, 63-163452
JP-A-62-153853, JP-A-63-146
No. 029 and the like can be used. Further, US Pat. No. 3,779,778 and European Patent No. 12
No. 6,712, etc., compounds which generate an acid by light can also be used.

[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 formula (V). In the formula (V), R ^1a
Is a hydrogen atom or a methyl group, R ^2a and R ^3a are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, W is a divalent organic group, X _a is an organic group, and H—O—X _a Is smaller than the Ip value of p-ethylphenol.
n is an integer of 0 to 4, preferably 1 or 2. When n is plural, plural W may be the same or different. The leaving group in the formula (V) corresponds to a group from _a carbon atom to which R ^2a and R ^3a are commonly bonded to ^Xa .

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 ^2a and R ^3a 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 _a in the formula (V) has a structure represented by the formula (IX). -LY (IX) In the formula (IX), 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. 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.
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 and a hexyl group, 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 for providing 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.

The monomer of the repeating unit having a leaving group of the present invention can be obtained by, for example, adding a vinyl ether having a predetermined leaving group to the side chain of the monomer having an addition-polymerizable unsaturated bond. Can be synthesized. Hereinafter, specific examples of the monomer 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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[0072]

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[0075]

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The acid-decomposable resin in 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 adjustments such as (3) alkali developability, (4) film loss (hydrophobicity and alkali-soluble group selection), (5) adhesion of unirradiated portion to substrate, (6) dry etching resistance, etc. can be made. .

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.

Specifically, the following monomers can be 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,
-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 the 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 resolving power, heat resistance, which is a general required performance of the resist. 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, or anionic polymerization. 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 4
0 mol%, preferably 10 to 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 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.

[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 preferably 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, the following formula (A)
A nitrogen-containing basic compound having a structure represented by (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,
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 non-irradiated portion tends to deteriorate.

[V] Fluorine and / or Silicon Surfactant The surfactant which can be used in the positive resist composition of the present invention is preferably a fluorine and / or silicon surfactant. It is preferable to contain one or more of a surfactant, a silicon-based surfactant, and a surfactant containing both a fluorine atom and a silicon atom. As these surfactants, for example, JP-A-62-36663
No., No. 61-226746, No. 61-226745, No. 62-170950,
No. 63-34540, JP-A-7-230165, No. 8-62834, No. 9-5
No. 4432, No. 9-5988, U.S. Pat.No. 5,405,720, No. 5360692
Nos. 5528981, 5296330, 5436098, 55561
No. 43, No. 5294511, No. 5824451, and the following commercially available surfactants can be used as they are. As a commercially available surfactant that can be used,
For example, F-top EF301, EF303, (Shin-Akita Chemical Co., Ltd.)
Manufactured), Florado FC430, 431 (Sumitomo 3M Limited)
), Megafac F171, F173, F176, F189, R08 (Dai Nippon Ink Co., Ltd.), Surflon S-382, SC101, 10
2, 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 0.001 to 2% by weight, and more preferably 0% by weight, based on the solid content of the whole composition in the composition of the present invention. 0.01 to 1% by weight. These surfactants may be added alone or in combination of two or more.

As the further progress of the semiconductor is pursued, in addition to the essential performance such as high resolution of the resist, 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 filtered after being dissolved in a solvent. 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 used for manufacturing a precision integrated circuit device (eg, silicon / silicon dioxide coating) or a photolithography mask manufacturing substrate (eg, A good resist pattern can be obtained by applying an appropriate coating method such as a spinner or a coater on a glass / Cr coating), irradiating with an electron beam or X-ray, 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, 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.

[0108]

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 acid by electron beam or X-ray (1-1) Synthesis of disulfone derivative (I-2) 20 g of p-toluenesulfonyl hydrazide is converted to pyridine 1
Then, 20.5 g of p-toluenesulfonyl chloride was slowly added thereto under ice-cooling. After stirring for a while, powder precipitated. This was collected by filtration, washed with water, and dried to obtain 35 g of 1,2-bis (p-toluenesulfonyl) hydrazine. When this was slowly added to 150 ml of concentrated nitric acid heated to 40 ° C., the reaction proceeded while foaming. After the addition, the mixture was stirred at room temperature for 1 hour and poured into 600 ml of distilled water. The precipitated powder was collected by filtration and washed with distilled water until the washing liquid became neutral. This was recrystallized from toluene to obtain 8.7 g of a disulfone derivative (I-2). Other compounds can be synthesized using the same method.

(1-2) Imidosulfonate derivative (I
Synthesis of I-2) To a solution of 16.31 g of N-hydroxyphthalimide, 15.18 g of triethylamine and 350 ml of tetrahydrofuran, 19.07 g of p-toluenesulfonic acid chloride was added dropwise over 30 minutes, and after completion of the addition, the mixture was stirred at room temperature for 3 hours. . Thereafter, the reaction solution was filtered, and the filtrate was diluted with 400 ml of ethyl acetate.
The organic layer was separated by separating with 200 ml of 1 / water and the solvent was distilled off. The residue was purified by silica gel chromatography to obtain 28.7 g.
To obtain an imidosulfonate derivative (II-2).

(1-3) Synthesis of Tetramethylammonium Pentafluorobenzenesulfonate 25 g of pentafluorobenzenesulfonyl chloride was dissolved in 100 ml of methanol under ice cooling, and 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.

(1-4) 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 (VI-1).

(1-5) 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. 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 concentrated to obtain di (4-t-amylphenyl) iodonium pentafluorobenzenesulfonate (VIII). −
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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[0118]

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[0119]

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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 compound 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 was dried in a vacuum dryer at 70 ° C. for 12 hours to obtain Resin 1. The weight-average molecular weight of VP-8000 was 9 using GPC measurement polystyrene as a standard sample.
800.

(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 and the resins used in Comparative Examples are shown below.

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[0124]

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[0128] Ip value of HO-X _a corresponding portion in formula (V) in which the resin has is as follows.
Oxford Molecular, software-CAChe4.1.1
Calculated using MOPAC (PM3 parameter). (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: 8.577 Resin 11: 7.698 Resin 12: 8.029 Resin 13: 8.500 Resin 14: 8.109 Resin 15: 8.015 Comparative resin: 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.

[0130] 2. Examples [Examples 1 to 15 and Comparative Example 1
-2] (1) Application of resist Resin 1 (2 g), acid generator I-2 (0.1 g), acid generator VI-7 (0.02 g), nitrogen-containing basic compound B-1
(0.0065 g), surfactant W-1 (0.0022
g) was dissolved in 21.5 g of propylene glycol monomethyl ether acetate, and this was filtered through a 0.1 μm Teflon (registered trademark) filter to prepare a resist solution of Example 1. Similarly, the types of the components were changed as shown in Table 1, and Examples 2 to 15 and Comparative Examples 1 to
A resist solution of No. 2 was prepared. Each sample solution was applied on a silicon wafer by using a spin coater, and 120
℃, dried on a vacuum adsorption type hot plate for 90 seconds,
A resist film having a thickness of 0.5 μm was obtained.

(2) Preparation of resist pattern An electron beam lithography apparatus (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.

(3) Evaluation of Sensitivity, Resolution, and Edge Roughness The sensitivity, resolution, and edge roughness were evaluated as described below. Table 2 shows the evaluation results.

[Sensitivity and Resolution] Sensitivity was 0.20 μm
(Line: space = 1: 1) was used as the sensitivity, and the critical resolution (line and space separated and resolved) at that dose was used as the resolution. 0.
For those in which a 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.

[Edge Roughness] A length-measuring scanning electron microscope S-8840 ((trade name) ) Manufactured by Hitachi, Ltd.), the distance from the reference line where the edge should be located was measured at 50 points, the standard deviation was determined, and the variance (3σ) was used as an index of the edge roughness. The smaller this value is, the better.

[0135]

[Table 1]

The abbreviations used in Table 1 indicate the following.

The acid generator is as follows. III-1: bis (trifluoromethylsulfonyl) diazomethane III-2: bis (phenylsulfonyl) diazomethane III-3: bis (4-fluorophenylsulfonyl)
Diazomethane III-4: Bis (2,4,6-trifluorophenylsulfonyl) diazomethane IV-1: Methylsulfonyl-benzoyl-diazomethane IV-2: Phenylsulfonyl-benzoyl-diazomethane IV-3: Phenylsulfonyl-4-fluorobenzoyl -Diazomethane

The organic basic compound is 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)

[0140]

[Table 2]

From the results shown in Table 2, it can be seen that the positive resist composition of the present invention has high sensitivity, high resolution, and excellent line pattern edge roughness.

In Examples 1 to 15, 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 X-ray Irradiation at 1: 1 Using each of the resist compositions of Examples 1 and 11 and Comparative Example 1, a film thickness of 0.40 μm was obtained in the same manner as in (1) above.
Was obtained. Next, patterning was performed in the same manner as in the above (2) except that a 1: 1 X-ray irradiator (gap value: 20 nm) was used, and the resist performance was evaluated in the same manner as in the above (3). Table 3 shows the evaluation results.

[0144]

[Table 3]

As is clear from Table 3, the resist composition of the present invention shows extremely excellent performance even under X-ray irradiation.

[0146]

The positive resist composition for electron beams or X-rays of the present invention has high sensitivity and high resolution and excellent edge roughness of a line pattern.

Continuation of the front page (72) Inventor Koji Shirakawa 4000 Kawajiri, Yoshida-cho, Haibara-gun, Shizuoka Prefecture F-term in Fujisha Shin Film Co., Ltd.

Claims (5)

[Claims] (A) a compound represented by any one of formulas (I) to (IV), which generates an acid upon irradiation with an electron beam or X-ray, and (b) a group which is eliminated by the action of an acid. (C) a resin having a residue of a compound having an ionization potential value (Ip value) smaller than the Ip value of p-ethylphenol, the solubility of which in an alkaline developer is increased by the action of an acid; A positive resist composition for electron beam or X-ray, comprising a solvent. Embedded image In the formula (I), Ar ³ and Ar ⁴ each independently represent a substituted or unsubstituted alkyl group, aryl group, aralkyl group or camphor group. In the formula (II), R ²⁰⁶ represents a substituted or unsubstituted alkyl group, aryl group, aralkyl group or camphor group. A represents a substituted or unsubstituted alkylene group, alkenylene group or arylene group. Embedded image Embedded image In formula (III) and (IV), R ^o, R each independently may have a substituent, an alkyl group or an aryl group. 2. The positive resist composition for electron beam or X-ray according to claim 1, wherein the resin (b) contains a repeating unit represented by the formula (V). Embedded image In the formula (V), R ^1a represents a hydrogen atom or a methyl group. R
^2a and R ^3a each independently represent a hydrogen atom or a group having 1 to 4 carbon atoms;
Represents an alkyl group. W represents a divalent organic group. X _a is an organic group, a H-O-X _a smaller group than the ionization potential value of an ionization potential value 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. The electron beam or X-ray for the electron beam or X-ray according to claim 1, wherein the compound (a) that generates an acid by irradiation with an electron beam or X-ray generates an aromatic sulfonic acid. Positive resist composition. 4. The electron beam according to claim 1, wherein the compound (a) that generates an acid by irradiation with an electron beam or X-ray generates a fluorine-containing sulfonic acid. Or a positive resist composition for X-rays. 5. The method according to claim 1, wherein the irradiation with the electron beam or the X-ray is performed.
In addition to the compounds that generate more acid, the compounds of formulas (VI) to (VI)
II) Irradiation of electron beam or X-ray represented by any of
An acid containing a compound that generates more acid
An electron beam or X-ray positive according to any one of claims 1 to 4,
-Type resist composition. Embedded imageIn the general formulas (VI) to (VIII), R₁~ R₃₇Is hydrogen
Atom, alkyl group, alkoxyl group, hydroxyl group,
Halogen atom or -SR₃₈Represents a group represented by -S
-R₃₈R in₃₈Represents an alkyl group or an aryl group.
R₁~ R₃₈May be the same or different
No. R₁~ R₁₅In case of, two or more selected from them
Are directly bonded to each other at the ends, or
And ring structure through elements selected from nitrogen and nitrogen
May be formed. R₁₆~ R ₂₇The same is true for
May form a ring structure. R₂₈~ R₃₇In the case of
Similarly, a ring structure may be formed. X^-Is a sulfo
Anion of acid.