JP2001264985A - Positive type resist composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chemical amplification type positive type photoresist composition which ensures improved edge roughness of a pattern, gives an excellent resist pattern profile and has high sensitivity. SOLUTION: The positive type resist composition contains (A) resin containing a specified cyclic structure in the principal chain, having <=5% content of a monomer corresponding to repeating structural units constituting the resin based on the total pattern area by GPC and having velocity of dissolution in an alkali developing solution increased by the action of an acid and (B) a compound which generates the acid when irradiated with active light or radiation.

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 used in an ultra microlithography process such as the production of an ultra LSI or a high-capacity micro chip, or other photofabrication processes. More specifically, the present invention relates to a positive resist composition which has excellent profile and high sensitivity, in which edge roughness is eliminated.

[0002]

2. Description of the Related Art In recent years, the degree of integration of integrated circuits has been increasing more and more, and in the manufacture of semiconductor substrates such as VLSIs, processing of ultrafine patterns having a line width of less than half a micron is required. It has become In order to satisfy the need, the wavelength used in an exposure apparatus used for photolithography is becoming shorter and shorter, and now it is considered to use excimer laser light (XeCl, KrF, ArF, etc.) having a short wavelength among far ultraviolet rays. Up to now.
A chemically amplified resist is used for forming a pattern in lithography in this wavelength region.

In general, chemically amplified resists can be broadly classified into three types: so-called two-component, 2.5-component and three-component resists. The two-component system combines a compound that generates an acid by photolysis (hereinafter referred to as a photoacid generator) and a binder resin. The binder resin is a resin having in its molecule a group (also referred to as an acid-decomposable group) that decomposes under the action of an acid to increase the solubility of the resin in an alkaline developer. The 2.5-component system further contains a low-molecular compound having an acid-decomposable group in such a two-component system. The three-component system contains a photoacid generator, an alkali-soluble resin, and the above low molecular compound.

The above-mentioned chemically amplified resist is suitable for a photoresist for irradiating ultraviolet rays or far ultraviolet rays, but among them, it is necessary to further meet the required characteristics in use. As a photoresist composition for an ArF light source, a resin having an alicyclic hydrocarbon moiety introduced therein for the purpose of imparting dry etching resistance has been proposed. However, such a phenomenon that the development with an aqueous solution of tetramethylammonium hydroxide (hereinafter referred to as TMAH), which has been widely used as a resist developing solution in the past, becomes difficult, and the resist is peeled off from the substrate during the development. Can be seen. In response to such a resist hydrophobization, measures such as mixing an organic solvent such as isopropyl alcohol with a developing solution have been studied, and although tentative results have been obtained, the swelling of the resist film and the process become complicated. This does not necessarily mean that the problem has been solved. In the approach of improving the resist, many measures have been taken to supplement various hydrophobic alicyclic hydrocarbon sites by introducing a hydrophilic group.

JP-A-10-10739 discloses an energy-sensitive resist containing a polymer obtained by polymerizing a monomer having an alicyclic structure such as a norbornene ring in its main chain, maleic anhydride, and a monomer having a carboxyl group. Materials are disclosed. JP-A-10-111569 discloses a radiation-sensitive resin composition containing a resin having an alicyclic skeleton in the main chain and a radiation-sensitive acid generator. JP-A-11-109632 describes that a resin containing a polar group-containing alicyclic functional group and an acid-decomposable group is used for a radiation-sensitive material.

As described above, a resin containing an acid-decomposable group used for a photoresist for exposure to far ultraviolet rays generally contains an aliphatic cyclic hydrocarbon group in the molecule at the same time. For this reason, the resin becomes hydrophobic, and there is a problem caused by the hydrophobicity. Various means for improving the above have been studied, but the above techniques still have many insufficient points, and improvements are desired.

In recent years, with the demand for miniaturization of semiconductor chips, the design pattern of the fine semiconductor is 0.13 to 0.13.
It reaches a fine area of 0.35 μm. However,
These compositions have a problem that the resolution of the pattern is hindered by factors such as the edge roughness of the line pattern. Here, the edge roughness refers to the top and bottom edges of a resist line pattern that fluctuate irregularly in a direction perpendicular to the line direction due to the characteristics of the resist. Means that the edge looks uneven.

[0008]

As described above, in the known technique of the conventional photoresist composition, roughness is observed at the edge of the pattern, and a stable pattern cannot be obtained. Therefore, further improvement is desired. Was. Accordingly, an object of the present invention is to provide a chemically amplified positive photoresist composition having improved pattern edge roughness and a high sensitivity which can provide an excellent resist pattern profile.

[0009]

Means for Solving the Problems As a result of intensive studies on the constituent materials of the positive type chemically amplified resist composition, the present inventors have achieved the object of the present invention by using a specific acid-decomposable resin. This led to the present invention. That is,
The above object is achieved by the following constitutions.

(1) (A) (i) At least one kind of repeating structural unit selected from the group of repeating structural units represented by the following general formulas (Ia) and (Ib) and the following general formula (II) Having a repeating structural unit represented by the formula: (ii)
An acid having a group that decomposes under the action of an acid, and (iii) the content of the monomer corresponding to the repeating structural unit constituting the resin is 5% or less of the entire pattern area of the gel permeation chromatography. A positive resist composition comprising a resin which increases the dissolution rate in an alkali developer by an action, and (B) a compound which generates an acid upon irradiation with actinic rays or radiation.

[0011]

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In the formula (Ia): R ₁ and R ₂ are each independently
Hydrogen atom, cyano group, hydroxyl group, -COOH, -COOR
₅ represents a _{-CO-NH-R 6, -CO} -NH-SO 2 -R 6, which may be substituted, an alkyl group, an alkoxy group or a cyclic hydrocarbon group, or the following -Y group. X represents an oxygen atom, a sulfur atom, -NH -, - NHSO ₂ - or -NH
Represents SO ₂ NH—. Here, R ₅ represents an optionally substituted alkyl group, cyclic hydrocarbon group or the following —Y group. R ₆ represents an alkyl group or a cyclic hydrocarbon group which may have a substituent. A represents a single bond or a divalent linking group. A —Y group;

[0013]

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(In the —Y group, R _{21 to} R ₃₀ are each independently
Represents a hydrogen atom or an alkyl group which may have a substituent. a and b represent 1 or 2. In formula (Ib): Z ₂ represents —O— or —N (R ₃ ) —. Here, R ₃ is a hydrogen atom, a hydroxyl group or —OSO ₂ —R
Represents ₄ . R ₄ represents an alkyl group, a haloalkyl group, a cycloalkyl group or a camphor residue. In the formula (II), R ₁₁ and R ₁₂ each independently represent a hydrogen atom, a cyano group, a halogen atom, or an alkyl group which may have a substituent. Z represents two bonded carbon atoms (C
-C) and represents an atomic group for forming an alicyclic structure which may have a substituent.

(2) In the general formula (II), Z is
The above-mentioned (1), which represents an atomic group for forming a bridged alicyclic structure which contains two bonded carbon atoms (C-C) and may have a substituent. A positive photoresist composition. (3) The above (1), wherein the general formula (II) is the following general formula (II-A) or general formula (II-B)
4. The positive photoresist composition according to item 1.

[0016]

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In the formulas (II-A) and (II-B): R _{13 to} R ₁₆
Is independently a hydrogen atom, a halogen atom, a cyano group,
—COOH, —COOR ₅ (R ₅ is as defined above), a group decomposed by the action of an acid, —C (＝ O) —X
-AR ₁₇ , or an alkyl group or a cyclic hydrocarbon group which may have a substituent. Further, at least two members out of R _{13 to} R ₁₆ may combine to form a ring. n represents 0 or 1. Here, X and A are as defined above. R ₁₇ represents —COOH, —COOR ₅ , —CN, a hydroxyl group, an optionally substituted alkoxy group, —CO
—NH—R ₆ , —CO—NH—SO ₂ —R ₆ (R ₅ , R
₆ each has the same meaning as described above) or the above-mentioned -Y group.

(4) The resin of the above (A) undergoes a polymerization reaction by heating a solution containing a monomer corresponding to a repeating structural unit constituting the resin and a radical initiator, and then further initiates a radical initiation. The positive resist composition according to the above (1), which is a polymer obtained by adding an agent, heating and performing a polymerization reaction again. (5) The resin of the above (A) is used to prepare a polymerization reaction solution after completion of the polymerization reaction by using water, alcohols, ethers, ketones, amides, esters and lactones, nitriles, hydrocarbons, and the like. The polymer according to the above (1), wherein the polymer is deposited in at least one kind of solvent selected from a solvent group consisting of a mixed solvent of the above to precipitate a polymer and then recovered as a powder. -Type resist composition.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, components used in the present invention will be described in detail. [1] (A) A resin whose dissolution rate in an alkali developer is increased by the action of an acid (also referred to as “acid-decomposable resin”).
Hereinafter, each component of the acid-decomposable resin of the present invention will be described.

In the above formula (Ia), R ₁ , R
₂ is each independently a hydrogen atom, a cyano group, a hydroxyl group, -C
_{OOH, -COOR 5, -CO-NH} -R 6, -CO-
NH-SO ₂ -R _6, which may be substituted, an alkyl group, an alkoxy group or a cyclic hydrocarbon group, or the -
Represents a Y group. Wherein, R ₅ may have a substituent, an alkyl group, cyclic hydrocarbon group or the -Y group. R ₆ represents an alkyl group or a cyclic hydrocarbon group which may have a substituent. In the above-mentioned -Y group, R ₂₁ to
R ₃₀ each independently represents a hydrogen atom or an alkyl group which may have a substituent, and a and b represent 1 or 2. X
It represents an oxygen atom, a sulfur atom, -NH -, - NHSO ₂ - or an -NHSO ₂ NH-. A represents a single bond or a divalent linking group.

In the formula (Ib), Z ₂ represents —O— or —N (R ₃ ) —. Here, R ₃ represents a hydrogen atom, a hydroxyl group, or —OSO ₂ —R ₄ . R ₄ represents an alkyl group, a haloalkyl group, a cycloalkyl group or a camphor residue.

The above R ₁ , R ₂ , R ₄ , R ₅ , R ₆ , R ₂₁
As the alkyl group for R _{30 to} R _{30, a} linear or branched alkyl group having 1 to 10 carbon atoms is preferable, and a linear or branched alkyl group having 1 to 6 carbon atoms is more preferable. Represents a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a t-butyl group. Examples of the cyclic hydrocarbon group for R ₁ , R ₂ , R ₅ , and R ₆ include a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, an adamantyl group, a 2-methyl-2-adamantyl group, a norbornyl group, a boronyl group, and an isobornyl group. ,
Examples include a tricyclodecanyl group, a dicyclopentenyl group, a nobornane epoxy group, a menthyl group, an isomenthyl group, a neomenthyl group, and a tetracyclododecanyl group. Examples of the alkoxy group in R ₁ and R ₂ include those having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group and a butoxy group. Examples of the haloalkyl group for R ₄ include a trifluoromethyl group, a nanofluorobutyl group, a pentadecafluorooctyl group, and a trichloromethyl group. Examples of the cycloalkyl group for R ₄ include a cyclopentyl group, a cyclohexyl group, and a cyclooctyl group.

Further substituents of the above alkyl group, cyclic hydrocarbon group and alkoxy group include a hydroxyl group, a halogen atom, a carboxyl group, an alkoxy group, an acyl group, a cyano group and an acyloxy group. Examples of the halogen atom include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom. 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. Examples of the acyl group include a formyl group and an acetyl group. Examples thereof include an acetoxy group.

The divalent linking group of A in the above formulas (Ia) and (Ib) includes an alkylene group, a substituted alkylene group, an ether group, a thioether group, a carbonyl group,
Examples thereof include a single group selected from the group consisting of an ester group, an amide group, a sulfonamide group, a urethane group, and a urea group, or a combination of two or more groups. Examples of the alkylene group and substituted alkylene group in A include groups represented by the following formula. -[C (R ₂ ) (R _b )] r- wherein R ₂ and R _b represent a hydrogen atom, an alkyl group, a substituted alkyl group, a halogen atom, a hydroxyl group, an alkoxy group,
Both may be the same or different. As the alkyl group, a lower alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, and a butyl group is preferable, and a methyl group, an ethyl group, a propyl group, and an isopropyl group are more preferable. As the substituent of the substituted alkyl group,
Examples include a hydroxyl group, a halogen atom and an alkoxy group. 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. Examples of the halogen atom include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom. r represents an integer of 1 to 10.

Specific examples of the repeating structural unit represented by the general formula (Ia) include the following [I-1] to [I-65], but the present invention is not limited to these specific examples. is not.

[0026]

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[0027]

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[0028]

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[0029]

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[0030]

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[0031]

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Specific examples of the repeating structural unit represented by the above general formula (Ib) include the following [I'-1] to [I'-7], but the present invention is limited to these specific examples. Not something.

[0033]

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[0034]

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In the above general formula (II), R ₁₁ , R
Each ₁₂ independently represents a hydrogen atom, a cyano group, a halogen atom, or an alkyl group which may have a substituent.
Z represents an atomic group containing two bonded carbon atoms (C-C) and forming an alicyclic structure which may have a substituent.

Examples of the halogen atom in R ₁₁ and R ₁₂ include a chlorine atom, a bromine atom, a fluorine atom and an iodine atom. The alkyl group for R ₁₁ and R ₁₂ is preferably a straight-chain or branched alkyl group having 1 to 10 carbon atoms, more preferably a straight-chain or branched alkyl group having 1 to 6 carbon atoms. More preferably methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group,
t-butyl group.

Further substituents on the alkyl groups of R ₁₁ and R ₁₂ include a hydroxyl group, a halogen atom, a carboxyl group, an alkoxy group, an acyl group, a cyano group and an acyloxy group. Examples of the halogen atom include a chlorine atom, a bromine atom, a fluorine atom and an iodine atom, and 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. And formyl group as acyl group,
An acetyl group and the like can be mentioned, and an acyloxy group can be an acetoxy group and the like.

The atomic group for forming the alicyclic structure of Z is an atomic group for forming a repeating structural unit of an alicyclic hydrocarbon which may have a substituent on the resin. An atomic group for forming a bridged alicyclic structure forming a repeating structural unit of an alicyclic hydrocarbon of the formula is preferred. Examples of the skeleton of the formed alicyclic hydrocarbon include those represented by the following structures.

[0039]

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[0040]

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Preferred bridged alicyclic hydrocarbon skeletons include (5), (6), (7),
(9), (10), (13), (14), (15),
(23), (28), (36), (37), (42),
(47).

The skeleton of the alicyclic hydrocarbon may have a substituent. Examples of such a substituent include R _{13 to} R ₁₆ in the general formula (II-A) or (II-B). Among the repeating structural units having a bridged alicyclic hydrocarbon, the repeating structural units represented by the general formula (II-A) or (II-B) are more preferable. In the general formula (II-A) or (II-B), R _{13 to} R ₁₆ each independently represent a hydrogen atom, a halogen atom, a cyano group, —COOH, or —COOR ₅ (R ₅ has a substituent. An alkyl group, a cyclic hydrocarbon group or a -Y group similar to that in the above general formula (I).
A group decomposed by the action of an acid, -C (= O) -XA-R
₁₇ or an alkyl group or a cyclic hydrocarbon group which may have a substituent. n represents 0 or 1. X represents an oxygen atom, a sulfur atom, -NH -, - NHSO ₂ - or -N
Represents HSO ₂ NH—. R ₁₇ is -COOH, -COO
R _5, -CN, hydroxyl, optionally substituted alkoxy _{group, -CO-NH-R 6,} -CO-NH-SO 2
—R ₆ (R ₅ and R ₆ have the same meanings as described above), or —Y in the above formula (Ia). A represents a single bond or a divalent linking group.

In the acid-decomposable resin used in the present invention, the acid-decomposable group includes the above-mentioned —C (＝ O) —X—A—R ₁ ,
It may be contained in —C (−O) —XA—R ₂ or as a substituent of Z in the general formula (II). The structure of the acid-decomposable group is represented by —C (＝ O) —X ₁ —R ₀ . In the formula, R ₀ represents a tertiary alkyl group such as t-butyl group, t-amyl group, isobornyl group, 1-ethoxyethyl group, 1-butoxyethyl group, 1-isobutoxyethyl group, 1-cyclohexyloxy 1-alkoxyethyl group such as ethyl group, 1-methoxymethyl group, alkoxymethyl group such as 1-ethoxymethyl group, 3-oxoalkyl group, tetrahydropyranyl group, tetrahydrofuranyl group, trialkylsilyl ester group, 3- Examples thereof include an oxocyclohexyl ester group, a 2-methyl-2-adamantyl group, a mevalonic lactone residue, and a 2- (γ-butyrolactonyloxycarbonyl) -2-propyl group. X ₁ has the same meaning as X described above.

Examples of the halogen atom in R _{13 to} R ₁₆ include a chlorine atom, a bromine atom, a fluorine atom and an iodine atom.

The alkyl group for R _{13 to} R ₁₆ is preferably a linear or branched alkyl group having 1 to 10 carbon atoms, more preferably a linear or branched alkyl group having 1 to 6 carbon atoms. And more preferably a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group and a t-butyl group.

Examples of the cyclic hydrocarbon group represented by R _{13 to} R ₁₆ include a cyclic alkyl group and a bridged hydrocarbon group, such as a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, an adamantyl group, and a 2-methyl-2-adamantyl. Group, norbornyl group, boronyl group, isobornyl group,
Examples include a tricyclodecanyl group, a dicyclopentenyl group, a nobornane epoxy group, a menthyl group, an isomenthyl group, a neomenthyl group, and a tetracyclododecanyl group. The ring formed by combining at least two of the above R _{13 to} R ₁₆ includes cyclopentene, cyclohexene, cycloheptane, cyclooctane and the like having 5 to 1 carbon atoms.
And 2 rings.

As the alkoxy group for R ₁₇ ,
Examples thereof include those having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group and a butoxy group.

Further substituents in the above alkyl group, cyclic hydrocarbon group and alkoxy group include a hydroxyl group, a halogen atom, a carboxyl group, an alkoxy group, an acyl group, a cyano group and an acyloxy group. As the halogen atom, a chlorine atom, a bromine atom, a fluorine atom,
And iodine 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. Examples of the acyl group include a formyl group and an acetyl group. Examples thereof include an acetoxy group.

Examples of the divalent linking group of A include a single bond, an alkylene group, a substituted alkylene group, an ether group, a thioether group, and a carbonyl group, similarly to the divalent linking group of A in formula (Ia). , An ester group, an amide group,
A single one selected from the group consisting of a sulfonamide group, a urethane group, and a urea group, or a combination of two or more groups is exemplified. As the alkylene group and the substituted alkylene group in the above A, 2 of A in the general formula (Ia)
Examples are the same as those of the valent linking group.

In the acid-decomposable resin used in the present invention, the group decomposed by the action of an acid includes a repeating structural unit represented by the general formula (Ia), a repeating structural unit represented by the general formula (Ib), It can be contained in at least one of the repeating structural units represented by the general formula (II) and the repeating structural units of the copolymer component described below.

The above general formula (II-A) or general formula (II
The various substituents of R _{13 to} R ₁₆ in —B) may be an atomic group for forming an alicyclic structure in the above general formula (II) or an atomic group Z for forming a bridged alicyclic structure. It also serves as a substituent.

The formula (II-A) or the formula (II)
Specific examples of the repeating structural unit represented by -B) include the following [II-1] to [II-166], but the present invention is not limited to these specific examples.

[0053]

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[0054]

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[0055]

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[0056]

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[0057]

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[0058]

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[0059]

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[0060]

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[0061]

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[0062]

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[0063]

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[0064]

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[0065]

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[0066]

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[0067]

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[0068]

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[0069]

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The acid-decomposable resin used in the present invention comprises at least one of the repeating structural units represented by the general formulas (Ia) and (Ib);
(Including one or more types of repeating structural units represented by the general formulas (II-A) and (II-B)), dry etching resistance, suitability for a standard developer, and substrate adhesion For the purpose of adjusting the properties, the resist profile, and the resolution, heat resistance, sensitivity, and the like, which are general requirements of the resist, a copolymer containing repeating structural units of various monomers can be used. Preferred copolymerization components include repeating structural units represented by the following general formulas (IV ') and (V').

[0071]

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Where Z is an oxygen atom, -NH-,-
_{N (-R 50) -, -} N (-OSO 2 R 50) - represents, R
₅₀ also has the same meaning as the above (substituted) alkyl group and (substituted) cyclic hydrocarbon group. The above general formulas (IV ') and (V')
Specific examples of the repeating structural unit represented by the following [IV '
-9] to [IV'-16], [V'-9] to [V'-16]
However, the present invention is not limited to these specific examples.

[0073]

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[0074]

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The acid-decomposable resin used in the present invention is further copolymerized with the following monomer as long as it provides a repeating structural unit constituting the resin within a range where the effects of the present invention can be effectively obtained. Although it may be, it is not limited to the following monomers. Thereby, the performance required for the resin, in particular, (1) solubility in a coating solvent, (2)
Film-forming properties (glass transition point), (3) alkali developability,
(4) membrane loss (hydrophilic / hydrophobic, alkali-soluble group selection),
Fine adjustment of (5) adhesion of the unexposed portion to the substrate and (6) dry etching resistance can be performed. Examples of such a copolymerizable monomer include, for example, an acrylate, a methacrylate, an acrylamide, a methacrylamide, an allyl compound, a vinyl ether, and an addition-polymerizable unsaturated bond selected from vinyl esters. Compounds having one can be mentioned.

Specifically, for example, acrylates such as alkyl (the alkyl group has 1 to 1 carbon atoms)
Acrylates (for example, methyl acrylate, ethyl acrylate, propyl acrylate, amyl acrylate, cyclohexyl acrylate, ethylhexyl acrylate, octyl acrylate, acrylate-
t-octyl, chloroethyl acrylate, 2-hydroxyethyl acrylate 2,2-dimethylhydroxypropyl acrylate, 5-hydroxypentyl acrylate, trimethylolpropane monoacrylate, pentaerythritol monoacrylate, benzyl acrylate, methoxybenzyl acrylate, furfuryl acrylate, Tetrahydrofurfuryl acrylate, etc.);

Methacrylic esters, for example, alkyl (alkyl having preferably 1 to 10 carbon atoms) methacrylate (for example, 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, pentaerythritol monomethacrylate, furfuryl methacrylate, tetrahydrofurfuryl methacrylate, etc.);

Acrylamides, for example, acrylamide, N-alkylacrylamide, wherein the alkyl group has 1 to 10 carbon atoms, for example, methyl, ethyl, propyl, butyl, t-butyl, heptyl, octyl Group, cyclohexyl group, hydroxyethyl group, etc.), N, N-dialkylacrylamide (alkyl group having 1 to 10 carbon atoms, for example, methyl group, ethyl group, butyl group, isobutyl group, ethylhexyl group, Cyclohexyl group, etc.), N-
Hydroxyethyl-N-methylacrylamide, N-2
-Acetamidoethyl-N-acetylacrylamide and the like;

Methacrylamides, for example, methacrylamide, N-alkyl methacrylamide (an alkyl group having 1 to 10 carbon atoms, for example, methyl, ethyl, t-butyl, ethylhexyl, hydroxyethyl, cyclohexyl) Groups, etc.), N, N-dialkylmethacrylamide (an alkyl group includes an ethyl group, a propyl group, a butyl group, etc.), N-hydroxyethyl-N-methylmethacrylamide and the like;

Allyl compounds such as allyl esters (eg, allyl acetate, allyl caproate, allyl caprylate, allyl laurate, allyl palmitate, allyl stearate, allyl benzoate, allyl acetoacetate, allyl lactate), allyloxy Ethanol, etc .;

Vinyl ethers such as 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-ethyl Butyl vinyl ether, hydroxyethyl vinyl ether, diethylene glycol vinyl ether, dimethylaminoethyl vinyl ether, diethylaminoethyl vinyl ether, butylaminoethyl vinyl ether, benzyl vinyl ether, tetrahydrofurfuryl vinyl ether, etc.);

Vinyl esters such as vinyl butyrate, vinyl isobutyrate, vinyl trimethyl acetate, vinyl diethyl acetate, vinyl valate, vinyl caproate, vinyl chloroacetate, vinyl dichlor acetate, vinyl methoxy acetate, vinyl butoxy acetate, Vinyl acetoacetate, vinyl lactate, vinyl-β-phenylbutyrate, vinylcyclohexylcarboxylate and the like;

Dialkyl itaconates (eg, dimethyl itaconate, diethyl itaconate, dibutyl itaconate, etc.); acrylic acid, methacrylic acid, crotonic acid, itaconic acid, acrylonitrile, methacrylonitrile and the like.

In the acid-decomposable resin used in the present invention, a repeating structural unit represented by the general formula (Ia) and / or the general formula (Ib) and a compound represented by the general formula (II) (general formula (II)
-A), the content of the repeating structural unit represented by the general formula (II-B) is as follows: the desired dry etching resistance of the resist, sensitivity, prevention of pattern cracking, substrate adhesion, resist profile, and It can be set as appropriate in consideration of the resolving power, heat resistance, and the like, which are necessary requirements of general resists. Generally, the acid-decomposable resin used in the present invention contains a repeating structural unit represented by the general formula (Ia) and / or (Ib) and a repeating structural unit represented by the general formula (II) The amount is
The amount is suitably at least 25 mol%, preferably at least 30 mol%, more preferably at least 35 mol%, in all the monomer repeating structural units of the resin.

Further, in the acid-decomposable resin used in the present invention, the content of the repeating structural unit (general formula (IV ′) or general formula (V ′)) derived from the above-mentioned preferable comonomer in the resin is preferable. The amount can also be appropriately set according to the desired performance of the resist, but is generally represented by the repeating structural unit represented by the general formula (Ia) and / or the general formula (Ib) and the general formula (II). It is preferably at most 99 mol%, more preferably at most 90 mol%, even more preferably at most 80 mol%, based on the total number of moles of the repeating structural units represented. Further, the content of the repeating structural unit based on the monomer of the further copolymerization component in the resin can be appropriately set according to the desired performance of the resist, but generally, the general formula (Ia) And / or a repeating structural unit represented by the general formula (Ib);
It is preferably 99 mol% or less, more preferably 90 mol%, based on the total number of moles of the repeating structural units represented by I).
Mol% or less, more preferably 80 mol% or less.
If the amount of the repeating structural unit based on the monomer of the further copolymer component exceeds 99 mol%, the effect of the present invention is not sufficiently exhibited, which is not preferable.

In the acid-decomposable resin used in the present invention, the group decomposed by the action of an acid is represented by the general formula (I)
a) and / or a repeating structural unit represented by the general formula (Ib), a repeating structural unit represented by the general formula (II), or a repeating structural unit based on a monomer of a copolymer component. The content of the repeating structural unit containing a group that is decomposed by the action of an acid is suitably 8 to 60 mol%, preferably 10 to 55 mol%, of all the repeating structural units in the resin. More preferably, 12
~ 50 mol%.

In the acid-decomposable resin used in the present invention, the content of the monomer corresponding to the repeating structural unit constituting the acid-decomposable resin is 5% of the total pattern area of gel permeation chromatography (GPC). Or less, preferably 0.01 to 4%, more preferably 0.1 to 3%.
%. Here, as an apparatus that can be used for performing the measurement by GPC, for example, Showa Denko KK
Shodex system-11. By setting the amount of the monomer contained in the acid-decomposable resin to the above amount, the photoresist composition becomes highly sensitive and a pattern profile with excellent edge roughness can be obtained.

The acid-decomposable resin used in the present invention comprises a monomer corresponding to the repeating structural unit represented by the general formula (II) and maleic anhydride, and in the case of using a copolymerization component, the copolymerization component. The monomers are copolymerized and copolymerized in the presence of a polymerization catalyst, and the repeating structural units derived from maleic anhydride in the obtained copolymer are subjected to ring-opening esterification with alcohols under basic or acidic conditions. Alternatively, it can be synthesized by a method of hydrolyzing and then converting the carboxylic acid moiety generated thereafter to a desired substituent.

The above-mentioned copolymerization (hereinafter, also simply referred to as “polymerization”) can be carried out according to a conventional method (for example, by radical polymerization). The following methods can be mentioned.

The monomer to be reacted is dissolved in a reaction solvent or made uniform without a solvent, heated and stirred under a nitrogen atmosphere to a desired temperature, and then a radical initiator is added all at once or dividedly. A solution in which a monomer to be reacted is dissolved in a reaction solvent together with an initiator, and this is heated to a desired temperature under a nitrogen atmosphere, or a part of the reaction solvent or the monomer is dissolved in the reaction solvent. For example, a dropping method in which the solution is gradually dropped may be used.

Preferably, the initiator is divided addition method or dropping method. By selecting this method, the resist performance, including the resolution and edge roughness, which are the effects of the present invention, although the details are completely unknown, are improved.

The reaction temperature can be appropriately set depending on the type of the initiator, but is generally from 30 ° C. to 180 ° C. Preferably 4
0 ° C to 160 ° C, more preferably 50 ° C to 14 ° C.
0 ° C.

In the case of the split addition method, the interval between additions of the initiator is 5 minutes to 6 hours, preferably 10 minutes to 5 hours.
More preferably, it is 15 minutes to 4 hours. The dropping time when the dropping method is employed can be variously set depending on the reaction temperature, the type of the initiator, and the monomer to be reacted.
Time. It is preferably 45 minutes to 6 hours, more preferably 1 hour to 5 hours.

In the case of the batch method or the split addition method, after completion of the addition of the initiator, the mixture is heated and stirred at a desired temperature under a nitrogen atmosphere for a certain period of time. Also in the case of the dropping method, after completion of the dropping, the mixture is heated and stirred at a desired temperature for a certain period of time in a nitrogen atmosphere. The heating time varies depending on the reaction temperature and the type of the initiator, but is generally within 24 hours. It is preferably within 20 hours, more preferably within 18 hours.

In any case, it is preferable to continue the heating and stirring for a predetermined time and then add the initiator again.
By adding an initiator, the details are unknown, but as a result, the sensitivity and the resolving power are improved. After the addition of the initiator, the mixture is heated and stirred for a certain period of time. After the addition of the initiator, the reaction temperature may be increased.

As the solvent used in the reaction, any solvent can be used as long as it does not dissolve the monomer species used and inhibits polymerization (inhibition of polymerization, for example, nitrobenzenes, chain transfer, for example, mercapto compounds). Examples thereof include alcohols, ethers, ketones, amides, esters and lactones, nitriles, hydrocarbons and mixtures thereof.

As alcohols, methanol, ethanol, propanol, isopropanol, butanol,
Ethylene glycol, propylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 1-methoxy-2-propanol,
Can be mentioned. As ethers, propyl ether, isopropyl ether, butyl methyl ether, tetrahydrofuran, 1,4-dioxane, 1,3
-Dioxolane and 1,3-dioxane. Examples of ketones include acetone, methyl ethyl ketone, diethyl ketone, methyl isopropyl ketone, and methyl isobutyl ketone.

Examples of the amides include N, N-dimethylformamide and N, N-dimethylacetamide. Examples of the esters and lactones include ethyl acetate, methyl acetate, isobutyl acetate, and γ-butyrolactone. Nitriles include acetonitrile, propionitrile, and butyronitrile. Examples of the hydrocarbons include linear or branched hydrocarbons such as pentane, hexane, heptane, and octane, cyclic hydrocarbons such as cyclopentane and cyclohexane, and aromatic hydrocarbons such as toluene and xylene. it can.

Preferred solvents are propyl ether,
Isopropyl ether, butyl methyl ether, tetrahydrofuran, 1,4-dioxane, 1,3-dioxolan, 1,3-dioxane, acetone, methyl ethyl ketone, diethyl ketone, methyl isopropyl ketone, methyl isobutyl ketone, ethyl acetate, and γ-butyrolactone are exemplified. be able to. Examples of the mixed solvent system include ethers, ethers and ketones, ethers and esters and lactones, ketones and esters and lactones.

Preferred mixed solvent systems are propyl ether and tetrahydrofuran, and propyl ether and 1,4
-Dioxane, propyl ether and 1,3-dioxolan, isopropyl ether and tetrahydrofuran, isopropyl ether and 1,4-dioxane, isopropyl ether and 1,3-dioxolan, tetrahydrofuran and 1,3-dioxolan, propyl ether and methyl ethyl ketone, propyl ether And methyl isopropyl ketone, isopropyl ether and methyl ethyl ketone, isopropyl ether and methyl isopropyl ketone, tetrahydrofuran and methyl ethyl ketone, tetrahydrofuran and methyl isopropyl ketone, 1,3-dioxolan and methyl ethyl ketone, 1,3-dioxolan and methyl isopropyl ketone, propyl ether and ethyl acetate , Propyl ether and γ-butyrolactone, isopropyl ether and acetic acid Chill, isopropyl ether and γ
-Butyrolactone, tetrahydrofuran and ethyl acetate,
Tetrahydrofuran and γ-butyrolactone, 1,3-dioxolane and ethyl acetate, 1,3-dioxolane and γ-
Butyrolactone, methyl ethyl ketone and ethyl acetate, methyl ethyl ketone and γ-butyrolactone, methyl isopropyl ketone and ethyl acetate, methyl isopropyl ketone and γ-butyrolactone.

The amount of the reaction solvent used varies depending on the target molecular weight, the monomer used, the type of initiator used, and the like. When considering a solution of the monomer and the solvent, the concentration of the monomer is 20% by weight or more.
It is preferably at least 30% by weight, more preferably 4% by weight.
The polymerization solvent is used so as to be 0% by weight or more.

The following are examples of the radical initiator that can be used in the polymerization reaction in the present invention. As the radical initiator, those generally used such as a peroxide and an azo initiator can be used. Preferred are azo-based initiators.

As the azo initiator, 2,2-azobis (4-methoxy-2,4-dimethylvaleronitrile),
2,2′-azobis (2-cyclopropylpropionitrile), 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile,
2,2′-azobis (2-methylbutyronitrile),
1,1′-azobis (cyclohexane-1-carbonitrile), 2,2′-azobis (2-methyl-N-phenylpropionamidine) dihydrochloride, 2,2′-
Azobis (2-methyl-N-2-propenylpropionamidine) dihydrochloride, 2,2′-azobis [2
-(5-Methyl-2-imidazolin-2-yl) propane] dihydrochloride, 2,2'-azobis {2-methyl-N- [1,1-bis (hydroxymethyl) -2-hydroxyethyl] propionamide ｝, Dimethyl 2,
2′-azobis (2-methylpropionate), 4,
4'-azobis (4-cyanovaleric acid),
2,2′-azobis (2- (hydroxymethyl) propionitrile) can be mentioned.

Preferably, 2,2'-azobis (2,4-
Dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 2,2'-azobis (2-methylbutyronitrile), 1,1'-azobis (cyclohexane-1
-Carbonitrile), dimethyl 2,2'-azobis (2
-Methylpropionate), 4,4'-azobis (4-
Cyanovaleric acid), 2,2′-azobis (2
-(Hydroxymethyl) propionitrile).

In the present invention, after the polymerization reaction as described above, the obtained polymer (resin) is preferably recovered by a reprecipitation method. That is, after completion of the polymerization, the polymerization reaction liquid is charged into the reprecipitation liquid, and the target resin is recovered as a powder.

Examples of the reprecipitated solution include water, alcohols, ethers, ketones, amides, esters and lactones, nitriles, hydrocarbons and mixtures thereof.

The alcohols include methanol, ethanol, propanol, isopropanol, butanol,
Examples include ethylene glycol, propylene glycol, and 1-methoxy-2-propanol. As ethers, propyl ether, isopropyl ether,
Butyl methyl ether, tetrahydrofuran, 1,4-
Examples thereof include dioxane, 1,3-dioxolan, and 1,3-dioxane.

As ketones, acetone, methyl ethyl ketone, diethyl ketone, methyl isopropyl ketone,
Methyl isobutyl ketone can be mentioned.
As amides, N, N-dimethylformamide, N,
N-dimethylacetamide can be mentioned. Examples of the esters and lactones include ethyl acetate, methyl acetate, isobutyl acetate, and γ-butyrolactone. Nitriles include acetonitrile, propionitrile, and butyronitrile.

The hydrocarbons include pentane, hexane,
Examples thereof include straight-chain or branched hydrocarbons such as heptane and octane, cyclic hydrocarbons such as cyclopentane and cyclohexane, and aromatic hydrocarbons such as toluene and xylene. As the mixed liquid system, a mixed liquid system between alcohols, a mixed liquid system between hydrocarbons, a hydrocarbon / alcohol system, a hydrocarbon / ether system, a hydrocarbon / ketone system, a hydrocarbon / ester and Lactones can be mentioned.

Specific examples of the mixed liquid system between alcohols include methanol and ethanol, methanol and propanol, methanol and isopropanol, methanol and butanol, ethylene glycol and ethanol, ethylene glycol and propanol, ethylene glycol and isopropanol, and ethylene glycol. Butanol, 1-methoxy-2-propanol and ethanol, 1-methoxy-2-propanol and propanol, 1-methoxy-2
-Propanol and isopropanol, 1-methoxy-2
-Specific examples of a mixed liquid system between propanol and butanol and hydrocarbons include commercially available mixed solvents such as Isopar G, hexane and heptane, hexane and octane, hexane and cyclohexane, hexane and toluene, hexane and xylene, and cyclohexane. Toluene and the like can be mentioned.

Examples of different mixed solvent systems include hexane and propanol, hexane and isopropanol, hexane and butanol, hexane and tetrahydrofuran, hexane and acetone, hexane and methyl ethyl ketone, and hexane and γ-butyrolactone. The mixing ratio of the mixed liquid system is from 20/1 to 1/20.

Preferred reprecipitates include commercially available mixed solvents such as hexane and Isopar G, hexane and heptane, hexane and octane, hexane and cyclohexane, hexane and toluene, cyclohexane and toluene, hexane and propanol, hexane and isopropanol, and hexane. Butanol, hexane and tetrahydrofuran, hexane and acetone, hexane and methyl ethyl ketone, hexane and γ-butyrolactone.

JP-A-9-73173 and 10-2
The reprecipitation liquids described in JP-A-07069 and JP-A-10-274852 are extremely dangerous, for example, reprecipitation in a hydrocarbon solvent typified by hexane or heptane. Therefore, it is not preferable. Further, for example, the operation of repeating re-precipitation as described in Japanese Patent Application Laid-Open No. H10-301285 merely increases the amount of waste liquid unnecessarily, resulting in inefficient operation and deterioration of edge roughness. In the present invention, the number of times of reprecipitation may be one to three times, and is preferably one.

The amount of the reprecipitated solution is appropriately set depending on the amount and type of the solvent used during the polymerization and the type of the reprecipitated solution, but is 3 to 100 times the polymerization solution. Preferably 4 times to 5 times
It is 0 times, and more preferably 5 times to 30 times. If the amount is small, separation from the powder to be recovered becomes difficult, and the working efficiency is deteriorated. If the amount is large, the amount of waste liquid increases, which is not preferable in terms of cost.

The molecular weight of the acid-decomposable resin as described above is weight average (Mw: value in terms of polystyrene by GPC method).
And preferably 3,000 to 100,000, more preferably 4,000 to 70,000, and still more preferably 5,
The range is from 000 to 50,000. The higher the molecular weight, the higher the heat resistance and the like, but on the other hand, the lower the developability and the like. Therefore, the balance is adjusted to an appropriate range.

In the positive resist composition of the present invention,
The compounding amount of the acid-decomposable resin in the entire resist composition is preferably 40 to 99.99% by weight, more preferably 50 to 99.97% by weight, based on the total solid content.

Preferred specific examples of the combination of repeating structural units of the acid-decomposable resin (A) are shown below.

[0118]

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[0119]

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[0120]

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[2] (B) Compound that Generates Acid upon Irradiation with Actinic Ray or Radiation (Photoacid Generator) The photoacid generator used in the present invention is a compound that generates an acid upon irradiation with actinic ray or radiation. It is. As the photoacid generator used in the present invention, a photoinitiator for photocationic polymerization, a photoinitiator for photoradical polymerization, a photodecolorant for dyes, a photochromic agent, or a microresist is used. Publicly known light (ultraviolet light of 400 to 200 nm, far ultraviolet light, particularly preferably g-ray, h-ray, i-ray, KrF excimer laser light), ArF excimer laser light, electron beam, X-ray,
A compound that generates an acid by a molecular beam or an ion beam and a mixture thereof can be appropriately selected and used.

Examples of other photoacid generators used in the present invention include onium salts such as diazonium salts, ammonium salts, phosphonium salts, iodonium salts, sulfonium salts, selenonium salts, and arsonium salts.
Organic halogen compound, organic metal / organic halide, o
A photoacid generator having a nitrobenzyl-type protecting group; a compound represented by photolysis such as iminosulfonate that generates sulfonic acid; a disulfone compound; a diazoketosulfone; and a diazodisulfone compound.
Further, a group in which an acid is generated by such light or a compound in which a compound is introduced into a main chain or a side chain of a polymer 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 decompose upon irradiation with an electron beam 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).

[0125]

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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
Is shown. Y represents a chlorine atom or a bromine atom. Specific examples include the following compounds, but the present invention is not limited thereto.

[0127]

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(2) An iodonium salt represented by the following formula (PAG3) or a sulfonium salt represented by the following formula (PAG4).

[0129]

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Here, the formulas Ar ¹ and Ar ² each independently represent a substituted or unsubstituted aryl group. R ²⁰³ , R ²⁰⁴ ,
R ²⁰⁵ each independently represents a substituted or unsubstituted alkyl group or aryl group.

Z ^- represents a counter anion, for example, B
F ₄ ⁻ , AsF ₆ ⁻ , PF ₆ ⁻ , SbF ₆ ⁻ , SiF ₆ ²⁻ , Cl
Condensed polynuclear aromatic sulfonic acid anions such as perfluoroalkanesulfonic acid anions such as O ₄ ⁻ and CF ₃ SO ₃ ⁻ , pentafluorobenzenesulfonic acid anion, naphthalene-1-sulfonic acid anion, anthraquinonesulfonic acid anion and sulfonic acid group Dyes and the like may be included, but are not limited thereto.

Further, two of R ²⁰³ , R ²⁰⁴ and R ²⁰⁵ and Ar ¹ and Ar ² may be bonded through a single bond or a substituent.

Specific examples include the following compounds, but are not limited thereto.

[0134]

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[0135]

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[0136]

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[0137]

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[0138]

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[0139]

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[0140]

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The onium salts represented by the general formulas (PAG3) and (PAG4) are known and described, for example, in US Pat.
It can be synthesized by the methods described in 2,807,648 and 4,247,473, JP-A-53-101,331 and the like.

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

[0143]

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In the formula, Ar ³ and Ar ⁴ each independently represent a substituted or unsubstituted aryl group. R ²⁰⁶ represents a substituted or unsubstituted alkyl group or aryl group. A represents a substituted or unsubstituted alkylene group, alkenylene group, or arylene group. Specific examples include the following compounds, but are not limited thereto.

[0145]

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[0146]

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[0147]

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(4) A diazodisulfone derivative represented by the following general formula (PAG7).

[0149]

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Here, R represents a linear, branched or cyclic alkyl group or an optionally substituted aryl group. Specific examples include the following compounds, but are not limited thereto.

[0151]

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The amount of the photoacid generator to be added is usually in the range of 0.001 to 40% by weight, preferably 0.01 to 20% by weight, more preferably 0.01 to 20% by weight, based on the solid content in the composition. Is used in the range of 0.1 to 5% by weight. When the addition amount of the photoacid generator is less than 0.001% by weight, the sensitivity is lowered. When the addition amount is more than 40% by weight, the light absorption of the resist becomes too high, and the profile deteriorates,
The process (especially baking) margin is unfavorably reduced.

[3] Other Components The positive resist composition of the present invention may further contain an acid-decomposable dissolution inhibiting compound, a dye, a plasticizer, a surfactant, if necessary.
A photosensitizer, an organic basic compound, a compound that promotes solubility in a developer, and the like can be contained.

The positive resist composition of the present invention preferably contains a fluorine-based and / or silicon-based surfactant. In the positive resist composition of the present invention, any of a fluorine-containing surfactant, a silicon-containing surfactant and a surfactant containing both a fluorine atom and a silicon atom, or
It is preferable to contain two or more types. When the positive resist composition of the present invention contains the above-mentioned acid-decomposable resin and the above-mentioned surfactant, it is particularly effective when the line width of the pattern is thinner, the development defects are further improved, and the resolution of the contact hole is improved. The image quality becomes better.

As these surfactants, for example, those described in
No. 62-36663, JP-A-61-226746, JP-A-61-226745,
JP-A-62-170950, JP-A-63-34540, JP-A-7-23016
No. 5, JP-A-8-62834, JP-A-9-54432, JP-A-9-598
The surfactant described in No. 8 can be used, and the following commercially available surfactant can be used as it is. Commercially available surfactants that can be used, for example, F-top EF301, EF3
03, (Shin-Akita Chemical Co., Ltd.), Florado FC430, 431 (Sumitomo 3M), MegaFac F171, F173, F176, F
189, R08 (Dainippon Ink Co., Ltd.), Surflon S-38
2, SC101, 102, 103, 104, 105, 106 (Asahi Glass Co., Ltd.)
Fluorosurfactants or silicone surfactants such as Troysol S-366 (produced by Troy Chemical Co., Ltd.). In addition, polysiloxane polymer KP-341
(Shin-Etsu Chemical Co., Ltd.) can also be used as a silicon-based surfactant.

The amount of the surfactant is usually 0.001 to 2% by weight, preferably 0.01 to 1% by weight, based on the solid content in the composition of the present invention. These surfactants may be added alone or in some combination. Examples of the surfactant that can be used in addition to the above include, specifically, polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, and polyoxyethylene oleyl ether. , Polyoxyethylene alkyl allyl ethers such as polyoxyethylene octyl phenol ether, polyoxyethylene nonyl phenol ether, polyoxyethylene / polyoxypropylene block copolymers, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan Sorbitan fatty acid esters such as monooleate, sorbitan trioleate, sorbitan tristearate, polyoxyethylene sorbitan Nonionic surfactants such as polyoxyethylene sorbitan fatty acid esters such as laurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, polyoxyethylene sorbitan tristearate And the like. The amount of these other surfactants is usually 2 parts by weight or less, preferably 1 part by weight or less, per 100 parts by weight of the solids in the composition of the present invention.

Preferred organic basic compounds that can be used in the present invention are compounds that are more basic than phenol. Among them, a nitrogen-containing basic compound is preferable.

[0158]

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Here, R²⁵⁰, R²⁵¹And R²⁵²Are each
Independently, a hydrogen atom, an alkyl group having 1 to 6 carbon atoms,
1-6 aminoalkyl groups, hydroxy having 1-6 carbon atoms
Alkyl group or substituted or unsubstituted 6 to 20 carbon atoms
An aryl group, where R ²⁵¹And R²⁵²Are connected to each other
To form a ring.

[0160]

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(Wherein R ²⁵³ , R ²⁵⁴ , R ²⁵⁵ and R
²⁵⁶ independently represent an alkyl group having 1 to 6 carbon atoms.) Further preferred compounds are nitrogen-containing basic compounds having two or more nitrogen atoms having different chemical environments in one molecule,
Particularly preferred are compounds containing both a substituted or unsubstituted amino group and a ring structure containing a nitrogen atom, or compounds 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 amino And alkyl morpholine. 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.

Preferred specific examples of the nitrogen-containing basic compound include guanidine, 1,1-dimethylguanidine,
1,3,3, -tetramethylguanidine, 2-aminopyridine, 3-aminopyridine, 4-aminopyridine,
-Dimethylaminopyridine, 4-dimethylaminopyridine, 2-diethylaminopyridine, 2- (aminomethyl) pyridine, 2-amino-3-methylpyridine, 2-
Amino-4-methylpyridine, 2-amino-5-methylpyridine, 2-amino-6-methylpyridine, 3-aminoethylpyridine, 4-aminoethylpyridine, 3-aminopyrrolidine, piperazine, N- (2-amino Ethyl) piperazine, N- (2-aminoethyl) piperidine, 4-amino-2,2,6,6-tetramethylpiperidine, 4-piperidinopiperidine, 2-iminopiperidine, 1- (2-aminoethyl) 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, 1,5-diazabicyclo [4.3.0] nona-
5-ene, 1,8-diazabicyclo [5.4.0] undec-7-ene, 1,4-diazabicyclo [2.2.2]
Octane, 2,4,5-triphenylimidazole, N
-Methylmorpholine, N-ethylmorpholine, N-hydroxyethylmorpholine, N-benzylmorpholine, cyclohexylmorpholinoethylthiourea (CHMET
U) and other tertiary morpholine derivatives, JP-A-11-5257
No. 5 hindered amines (for example, those described in the gazette [0005]) and the like, but are not limited thereto.

Particularly preferred specific examples are 1,5-diazabicyclo [4.3.0] non-5-ene, 1,8-diazabicyclo [5.4.0] undec-7-ene, 1,4-diazabicyclo [2.2.2] Tertiary morpholines such as octane, 4-dimethylaminopyridine, hexamethylenetetramine, 4,4-dimethylimidazoline, pyrroles, pyrazoles, imidazoles, pyridazines, pyrimidines, CHMETU, etc., and bis Hindered amines such as (1,2,2,6,6-pentamethyl-4-piperidyl) sebagate and the like can be mentioned. Among them, 1,5-diazabicyclo [4.3.0] non-5-ene, 1,8-
Diazabicyclo [5.4.0] undec-7-ene,
1,4-diazabicyclo [2.2.2] octane, 4-
Dimethylaminopyridine, hexamethylenetetramine,
CHMETU, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebagate is preferred.

These nitrogen-containing basic compounds are used alone or in combination of two or more. The amount of the nitrogen-containing basic compound to be used is generally 0.001 to 10% by weight, preferably 0.01 to 5% by weight, based on the solid content of the entire photosensitive resin composition. If the amount is less than 0.001% by weight, the effect of the addition of the nitrogen-containing basic compound cannot be obtained. On the other hand, if it exceeds 10% by weight, the sensitivity tends to decrease and the developability of the unexposed portion tends to deteriorate.

[4] Preparation and Use of Positive Resist Composition The positive resist composition of the present invention is dissolved in a solvent capable of dissolving each of the above components and applied 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, toluene, ethyl acetate, methyl lactate, ethyl lactate, methyl methoxypropionate, ethyl ethoxypropionate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, N, N-dimethyl Formamide, dimethyl sulfoxide, N-methylpyrrolidone, tetrahydrofuran and the like are preferable. Or mixed to use.

Among the above, preferred solvents are 2-
Heptanone, γ-butyrolactone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether, propylene glycol monoethyl ether, methyl lactate, ethyl lactate, methyl methoxypropionate, ethyl ethoxypropionate , N-methylpyrrolidone and tetrahydrofuran.

Such a positive resist composition of the present invention is applied on a substrate to form a thin film. The thickness of this coating film is preferably from 0.2 to 1.2 μm. In the present invention,
If necessary, a commercially available inorganic or organic antireflection film can be used.

As the antireflection film, an inorganic film type such as titanium, titanium dioxide, titanium nitride, chromium oxide, carbon, α-silicon, and an organic film type comprising a light absorbing agent and a polymer material can be used. The former requires equipment such as a vacuum deposition apparatus, a CVD apparatus, and a sputtering apparatus for film formation. As the organic antireflection film, for example, Japanese Patent Publication No. 7-69
No. 611, consisting of a condensate of a diphenylamine derivative and a formaldehyde-modified melamine resin, an alkali-soluble resin, and a light absorbing agent; a reaction product of a maleic anhydride copolymer and a diamine type light absorbing agent described in US Pat. No. 5,294,680; No. 6,118,631 containing a resin binder and a methylolmelamine-based thermal crosslinking agent; Japanese Patent Application Laid-Open No. 6-118656, an acrylic resin type antireflection film having a carboxylic acid group, an epoxy group and a light absorbing group in the same molecule; JP-A-8-87115, comprising a methylolmelamine and a benzophenone-based light-absorbing agent;
No. 79509 in which a low molecular weight light absorbing agent is added to a polyvinyl alcohol resin. As an organic anti-reflection film, DUV3 manufactured by Brewer Science Co., Ltd.
0 series, DUV-40 series, AC-2 and AC-3 manufactured by Shipley Co. can also be used.

The resist solution is applied onto a substrate (eg, a silicon / silicon dioxide coating) used for the production of precision integrated circuit devices (on a substrate provided with the antireflection film if necessary), a spinner, a coater, and the like. After coating by an appropriate coating method such as that described above, exposure through a predetermined mask, baking and development can provide a good resist pattern. Here, the exposure light is preferably 150
It is light having a wavelength of nm to 250 nm. Specifically, Kr
F excimer laser (248 nm), ArF excimer laser (193 nm), F ₂ excimer laser (157
nm), X-rays, electron beams and the like.

Examples of the developing solution include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia;
Primary amines such as ethylamine and n-propylamine;
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 hydroxide and the like An alkaline aqueous solution such as a quaternary ammonium salt, a cyclic amine such as pyrrole, or pyrhelidine can be used. Further, an appropriate amount of an alcohol or a surfactant may be added to the above alkaline aqueous solution.

[0171]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to the following examples.

(1) Synthesis of resin (1) -1 (divisional addition method, with addition of initiator) The following tetracarboxylic acid obtained by the reaction of acrylic acid ester of 3-oxo-1,1-dimethylbutanol with cyclopentadiene An equimolar mixture of the cyclododecene derivative (1-1) and maleic anhydride was charged into a separable flask and heated at 80 ° C under a nitrogen atmosphere. When the reaction temperature became stable, 1 radical initiator V-601 manufactured by Wako Pure Chemical Industries, Ltd. was added.
The reaction was started by adding mol%. After heating for 2 hours,
mol-% V-601 was added, and the mixture was further heated for 2 hours. Further, 1 mol% of V-601 was added, and the mixture was further heated for 12 hours.
Thereafter, 1 mol% of V-601 was added, and after heating for 3 hours, the reaction mixture was diluted twice with tetrahydrofuran and then poured into a mixed solution of hexane / isopropyl alcohol = 2/1 to precipitate a white powder. Was. The precipitated powder was taken out by filtration and dried to obtain the intended resin (1-1). When molecular weight analysis of the obtained resin (1-1) by GPC was attempted, it was 9600 (weight average) in terms of polystyrene. The remaining monomer area ratio is 1.8.
%Met. Further, the resin (1-
It was confirmed that the ratio of the repeating unit of tetracyclododecene and the repeating unit of maleic anhydride in 1) was 1/1.

[0173]

Embedded image

(2) Synthesis of resin (1) -2 (batch addition method, with addition of initiator) The above-mentioned tetra obtained by reaction of acrylic acid ester of 3-oxo-1,1-dimethylbutanol with cyclopentadiene. An equimolar mixture of the cyclododecene derivative (1-1) and maleic anhydride was charged into a separable flask and heated at 80 ° C under a nitrogen stream. When the reaction temperature was stabilized, 3 mol of radical initiator V-601 manufactured by Wako Pure Chemical Industries, Ltd. was added.
The reaction was started by adding 1% and heated for 12 hours. Then 1
After adding mol-% V-601 and heating for 3 hours, the reaction mixture was diluted twice with tetrahydrofuran and then poured into a mixed solution of hexane / isopropyl alcohol = 2/1 to precipitate white powder. The precipitated powder was taken out by filtration, and dried to obtain a target resin (1) -2.

The molecular weight of the obtained resin (1) -2 was analyzed by GPC.
(Weight average). The remaining monomer area ratio was 3.3%. From the NMR spectrum, it was confirmed that the ratio of the tetracyclododecene repeating unit to the maleic anhydride repeating unit of the resin (1) -2 was 1/1.

(3) Synthesis of Resin (1) -3 (drop polymerization,
With the addition of an initiator) An equimolar mixture of the above tetracyclododecene derivative (1-1) and maleic anhydride obtained by reacting an acrylic acid ester of 3-oxo-1,1-dimethylbutanol with cyclopentadiene is used. It was dissolved in a mixed solvent of tetrahydrofuran / methyl ethyl ketone = 1/1 to prepare a solution having a concentration of 60%. This 1/5 solution was charged into a separable flask, and 1.5 mol% of a radical initiator V-601 manufactured by Wako Pure Chemical Industries, Ltd. was added to the remaining solution. The reaction vessel was heated at 70 ° C. under a nitrogen stream, and when the reaction temperature was stabilized, 0.5 mol% of a radical initiator V-601 manufactured by Wako Pure Chemical Industries, Ltd. was added to start the reaction. Continue with the remaining monomer solution for 8
The mixture was added dropwise over a period of time, and heated for 4 hours after completion of the addition. Then, after adding 1 mol% of V-601 and heating for 3 hours,
Hexane / isopropyl alcohol = 5 /
The mixture was poured into the mixed solution of Example 1 to precipitate a white powder. The precipitated powder is filtered out, dried, and the target resin (1)
-3 was obtained.

An attempt was made to analyze the molecular weight of the obtained resin (1) -3 by GPC.
(Weight average). The remaining monomer area ratio was 2.3%. From the NMR spectrum, it was confirmed that the ratio of the repeating unit of tetracyclododecene to the repeating unit of maleic anhydride in the resin (1) -3 was 1/1.

Resins ((2) -1 to (12) -2) shown in Table 1 were synthesized by the same operation as in the above synthesis example (the number of the repeating unit is the same as that of the resins (2) to (12) described above). Represents the order from the left of the repeating unit in the structure of). Table 1 shows the molar ratio, weight average molecular weight, and residual monomer amount of each repeating unit of the resins (2) -1 to (12) -2.

[0179]

[Table 1]

Solvent a; isopropyl alcohol solvent b; isopropyl ether solvent c; tetrahydrofuran solvent d; acetone solvent e; methyl ethyl ketone solvent f; ethyl acetate solvent g; γ-butyrolactone solvent h; hexane solvent i; isoper G solvent j;

The initiator used was the above-mentioned radical initiator V-601 manufactured by Wako Pure Chemical Industries, Ltd.

Examples 1 to 25 and Comparative Examples 1 and 2 (Preparation and Evaluation of Positive Resist Composition) 1.4 g of each of the resins shown in Tables 2 and 3 synthesized in the above synthesis examples were prepared.
0.2 g of the photoacid generator shown in Tables 2 and 3, 10 mg of the organic basic compound (amine), and if necessary, a surfactant (0.15
g), and each was dissolved in propylene glycol monomethyl ether acetate at a solid content of 14% by weight, and then filtered through a 0.1 μm microfilter to obtain positive resists of Examples 1 to 25 and Comparative Examples 1 and 2. A composition was prepared. Tables 2 and 3 show the details of the composition of the prepared positive resist composition. WO9 is used as a resin for the comparative example.
The resin described in Synthesis Example 24 described in 7/33198 was used as the resin R1 (the residual monomer area ratio was 5.4%), and the resin described in Synthesis Example 7 described in JP-A-10-111569 was used. The resin was used as resin R2 (residual monomer area ratio is 6.3%). Further, the positive resist composition prepared by the method described below was evaluated, and the results are shown in Table 2.

In Tables 2 and 3 below, the photoacid generators are indicated by the numbers of the specific examples described above. As the amine, 1 represents 1,5-diazabicyclo [4.3.0] -5-nonene (DBN) and 2 represents bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebagate. .

As the surfactant, W1: Megafac F176 (manufactured by Dainippon Ink and Chemicals, Inc.)
(Fluorine) W2: Megafac R08 (Dai Nippon Ink Co., Ltd.)
(Fluorine and silicone type) W3: Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) W4: Polyoxyethylene nonylphenyl ether W5: Troysol S-366 (Troy Chemical Co., Ltd.)
).

(Evaluation Test) The obtained positive resist solution was applied on a silicon wafer using a spin coater.
After drying at 150 ° C. for 90 seconds, a positive photoresist film having a thickness of about 0.4 μm was formed and exposed to an ArF excimer laser (exposed with an ISI ArF stepper having a wavelength of 193 nm and NA = 0.6). The heat treatment after exposure was performed at 150 ° C. for 90 seconds, developed with a 2.38% aqueous solution of tetramethylammonium hydroxide, and rinsed with distilled water to obtain a resist pattern profile. For these, sensitivity, profile, and edge roughness were evaluated as follows. Tables 2 and 3 show the evaluation results.

[Sensitivity]: The relative light exposure was defined assuming that the light exposure for reproducing the line width of 0.15 μm was 1 in Example 1.

[Profile]: 1/1 of 0.15 μm
Observe the line-and-space line profile with a scanning electron microscope.O for a rectangular profile, △ for a slightly tapered or slightly hemmed profile,
A profile having a completely tapered shape or a slightly hemmed shape was evaluated as x.

[Edge Roughness]: The edge roughness was measured with an edge roughness of an isolated pattern (0.15 μm) using a length-measuring scanning electron microscope (SEM).
Within the measurement monitor, the line pattern edge is detected at a plurality of positions, and the variance (3σ) of the variation in the detected position is used as an index of the edge roughness. The smaller the value, the better.

[0189]

[Table 2]

[0190]

[Table 3]

As is clear from the results shown in Tables 2 and 3, the positive resist composition of the present invention has a sufficient sensitivity, a good profile and an excellent edge roughness.

[0192]

The positive resist composition of the present invention is suitable for far ultraviolet light, particularly ArF excimer laser light having a wavelength of 193 nm, has high sensitivity, and has excellent performance in edge roughness. The profile is excellent. Therefore, it is suitably used for lithography using far ultraviolet rays such as ArF excimer laser exposure.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) C08F 222/40 C08F 222/40 232/00 232/00 C08K 5/3492 C08K 5/3492 5/353 5/353 5 / 41 5/41 5/42 5/42 C08L 35/00 C08L 35/00 45/00 45/00 H01L 21/027 H01L 21/30 502R F-term (reference) 2H025 AA02 AA03 AB16 AC04 AC08 AD03 BE00 BE07 BE10 BJ05 BJ10 CB10 CB14 CB43 CB45 CB52 CB56 FA17 4J002 BH021 BK001 EU186 EU216 EV216 EV236 FD206 GP03 4J100 AK32P AM43P AM45P AM47P AR09Q AR11Q BA02H BA02P BA02Q BA03H BA03P BA03Q BA05H BA06Q BA11H BA06H BA06H BA06H BA06H BA06H BA59H BB01Q BB17P BC04H BC04Q BC07H BC07P BC07Q BC09H BC09Q BC12H BC12Q BC53H BC53Q CA04 CA05 CA31 GC07 HA08 HA11 JA38

Claims (5)

[Claims] (A) (i) at least one repeating structural unit selected from the group consisting of repeating structural units represented by the following general formulas (Ia) and (Ib), and (Ii) having a group decomposable by the action of an acid, and (iii) having a monomer content corresponding to the repeating structural unit constituting the resin in gel permeation chromatography. It is characterized by containing a resin which is not more than 5% of the total pattern area of the lithography and which increases the dissolution rate in an alkali developer by the action of an acid, and (B) a compound which generates an acid by irradiation with actinic rays or radiation. Positive resist composition. Embedded image In the formula (Ia): R ₁ and R ₂ each independently represent a hydrogen atom, a cyano group, a hydroxyl group, —COOH, —COOR ₅ , or —CO—
_{NH-R 6, -CO-NH} -SO 2 -R 6, which may be substituted, an alkyl group, an alkoxy group or a cyclic hydrocarbon group, or the following -Y group. X represents an oxygen atom, a sulfur atom, -NH -, - NHSO ₂ - or -NHSO ₂ NH-
Represents Here, R ₅ may have a substituent,
Represents an alkyl group, a cyclic hydrocarbon group or the following -Y group. R
₆ represents an alkyl group or a cyclic hydrocarbon group which may have a substituent. A represents a single bond or a divalent linking group. —Y group; (In the —Y group, R _{21 to} R ₃₀ each independently represent a hydrogen atom or an alkyl group which may have a substituent. A and b represent 1 or 2.) In the formula (Ib) : Z ₂ is, -O- or -N (R ₃₎ - represents a. Here, R ₃ is a hydrogen atom, a hydroxyl group or —OSO ₂ —R
Represents ₄ . R ₄ represents an alkyl group, a haloalkyl group, a cycloalkyl group or a camphor residue. In the formula (II), R ₁₁ and R ₁₂ each independently represent a hydrogen atom, a cyano group, a halogen atom, or an alkyl group which may have a substituent. Z represents two bonded carbon atoms (C
-C) and represents an atomic group for forming an alicyclic structure which may have a substituent. 2. The compound according to claim 1, wherein Z in the general formula (II) contains two bonded carbon atoms (CC) and forms a bridged alicyclic structure which may have a substituent. The positive photoresist composition according to claim 1, which represents an atomic group. 3. The compound represented by the general formula (II)
The positive photoresist composition according to claim 1, wherein the composition is A) or the general formula (II-B). Embedded image In the formulas (II-A) and (II-B), R _{13 to} R ₁₆ each independently represent a hydrogen atom, a halogen atom, a cyano group, —COOH,
—COOR ₅ (R ₅ is as defined above), a group decomposed by the action of an acid, —C (＝ O) —XA—R ₁₇ ,
Or an alkyl group or a cyclic hydrocarbon group which may have a substituent. Further, at least two members out of R _{13 to} R ₁₆ may combine to form a ring. n represents 0 or 1. Here, X and A are as defined above. R
_17, -COOH, -COOR _5, -CN, a hydroxyl group, an alkoxy group which may have a substituent, -CO-NH-
R ₆ , —CO—NH—SO ₂ —R ₆ (R ₅ and R ₆ each have the same meaning as described above), or the above-mentioned —Y group. 4. The resin of (A) above, after a solution containing a monomer corresponding to a repeating structural unit constituting the resin and a radical initiator is heated to carry out a polymerization reaction, and then a radical initiator is further added. And a polymer obtained by heating and performing a polymerization reaction again.
4. The positive resist composition according to item 1. 5. The polymerization reaction solution after completion of the polymerization reaction, wherein the resin (A) is water, alcohols, ethers, ketones, amides, esters and lactones, nitriles, hydrocarbons, The polymer according to claim 1, wherein the polymer is collected as a powder after being added to at least one solvent selected from a solvent group consisting of a mixed solvent thereof to precipitate the polymer. Positive resist composition.