JP2006023489A - Positive resist composition and pattern forming method using same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a positive resist composition which ensures few development defects and excels in the margin of pattern falling, and a pattern forming method using the same. <P>SOLUTION: The chemically amplified positive resist composition contains (A) a resin containing a carboxyl group in a backbone or a side chain thereof and having solubility in an alkali developer increased by the action of an acid and (B) an epoxy compound. The pattern forming method using the same is also provided. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a positive resist composition used in semiconductor manufacturing processes such as ICs, circuit boards such as liquid crystals and thermal heads, and other photofabrication processes. More specifically, the present invention relates to a positive resist composition suitable for use as an exposure light source such as far ultraviolet rays of 250 nm or less and an irradiation source using an electron beam.

  In recent years, the degree of integration of integrated circuits has been increasing, and in the manufacture of semiconductor substrates such as VLSI, processing of ultrafine patterns having a line width of less than half a micron has been required. In order to satisfy this need, the wavelength used by exposure apparatuses used in photolithography has become shorter, and now it is considered to use excimer laser light (XeCl, KrF, ArF, etc.) having a short wavelength among far ultraviolet rays. It is becoming. A chemical amplification type resist is used for lithography pattern formation in this wavelength region.

  In general, chemically amplified resists can be broadly classified into three types, commonly called two-component systems, 2.5-component systems, and three-component systems. 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 by the action of an acid and increases the solubility of the resin in an alkaline developer. The 2.5 component system further contains a low molecular weight compound having an acid-decomposable group in the two component system. A three-component system contains a photoacid generator, an alkali-soluble resin, and the low molecular weight compound.

  The chemical amplification resist is suitable as a photoresist for irradiation with ultraviolet rays or far ultraviolet rays, but among them, it is necessary to cope with the required characteristics in use. For example, when a 248 nm light of a KrF excimer laser is used, a resist composition using a polymer in which an acetal group or a ketal group is introduced as a protective group in a hydroxystyrene-based polymer that has little light absorption has been proposed. These are suitable when using 248 nm light of a KrF excimer laser, but when using an ArF excimer laser as a light source, the intrinsic sensitivity is still too high and the sensitivity is low. In addition, there are other disadvantages associated therewith, such as degradation of resolution, degradation of focus tolerance, degradation of pattern profile, and the like, and many improvements are still required.

  Therefore, as a photoresist composition for an ArF light source, a photoresist composition in which a (meth) acrylic resin that absorbs less light than a partially hydroxylated styrene resin is combined with a compound that generates an acid by light is proposed. Has been. Among them, Patent Document 1 (Japanese Patent Laid-Open No. 6-289615) discloses a resin in which a tertiary carbon organic group is ester-bonded to oxygen of a carboxyl group of acrylic acid.

  Furthermore, Patent Document 2 (Japanese Patent Laid-Open No. 7-234511) discloses an acid-decomposable resin having a repeating unit of acrylic acid ester or fumaric acid ester, but the pattern profile, substrate adhesion, etc. are insufficient. The fact is that satisfactory performance has not been obtained.

  Furthermore, a resin in which an alicyclic hydrocarbon moiety is introduced has been proposed for the purpose of imparting dry etching resistance. However, since the system becomes extremely hydrophobic as an adverse effect of the introduction of the alicyclic hydrocarbon moiety, Phenomena such as difficulty in development with an aqueous solution of tetramethylammonium hydroxide (hereinafter TMAH) that has been widely used as a resist developer, and the resist peeling off from the substrate during development are observed. In response to the hydrophobization of the resist, measures such as mixing an organic solvent such as isopropyl alcohol with the developer have been studied, and although some results are seen, the concern about the swelling of the resist film and the process become complicated. The problem is not necessarily solved. In the approach of improving the resist, many measures have been taken to supplement various hydrophobic alicyclic hydrocarbon sites by introducing hydrophilic groups.

  Patent Document 3 (JP-A-6-273933), Patent Document 4 (JP-A 2002-214765), Patent Document 5 (JP-A 2002-195506), Patent Document 6 (JP-2003-195505). Discloses a resist composition containing an epoxy compound. However, sufficient performance was not obtained for these.

  In general, we have taken measures to copolymerize a monomer having a carboxylic acid moiety such as acrylic acid or methacrylic acid with a monomer having an alicyclic hydrocarbon group. A problem has arisen that the line pattern collapses.

JP-A-6-289615 JP-A-7-234511 JP-A-6-273933 JP 2002-214765 A JP 2002-195506 A JP 2003-195505 A

  Accordingly, an object of the present invention is to solve the above-described problems of the performance improvement technology inherent in microphotofabrication using far ultraviolet light, particularly ArF excimer laser light. Specifically, there is no problem of development defects. Another object of the present invention is to provide an excellent positive resist composition in which a fine line pattern does not collapse.

  As a result of intensive studies on the constituent materials of the resist composition in the positive chemical amplification system, the present inventors have found that the object of the present invention can be achieved by using a specific acid-decomposable resin and a specific additive. As a result, the present invention has been achieved. That is, the above object is achieved by the following configuration.

(1) A chemically amplified positive resist composition comprising (A) a resin containing a carboxyl group and having increased solubility in an alkaline developer by the action of an acid, and (B) an epoxy compound.

(2) The chemically amplified positive resist composition as described in (1), wherein the resin (A) has a monocyclic or polycyclic alicyclic hydrocarbon structure.

(3) The chemically amplified positive resist composition according to (1) or (2), wherein the ratio of the carboxyl group of the resin (A) to the total polymerization units constituting the resin is 0.5 to 20 mol%. .

(4) The resin (A) contains at least one repeating unit derived from a polymerization component selected from acrylic acid, methacrylic acid, maleic acid, and maleic acid monoester. (1) to (3) The chemically amplified positive resist composition as described.

(5) The chemically amplified positive resist composition according to (1) to (4), wherein the epoxy compound (B) is a polyfunctional epoxy compound.

(6) The chemically amplified positive resist composition according to (5), wherein the polyfunctional epoxy compound is a bifunctional epoxy compound.

(7) The chemically amplified positive resist composition according to (6), wherein the bifunctional epoxy compound has a structure represented by the following formula (I):

In the formula, R _a101 , R _a102 , R _a103 and R _a104 each independently represent a hydrogen atom, a methyl group or an ethyl group, and A ₁ represents a divalent organic group.

(8) A pattern forming method comprising: forming a resist film from the resist composition according to any one of (1) to (7); and exposing and developing the resist film.

  Since the positive resist composition of the present invention has very few development defects and is excellent in a pattern collapse margin, it can be effectively used for forming a fine pattern necessary for manufacturing a semiconductor element.

Hereinafter, the present invention will be described in detail.
In addition, in the description of group (atomic group) in this specification, the description which is not describing substitution and non-substitution includes what has a substituent with what does not have a substituent. For example, the “alkyl group” includes not only an alkyl group having no substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group).

(A) Resin containing a carboxyl group in the main chain or side chain of the resin and having increased solubility in an alkaline developer by the action of an acid The resist composition of the present invention contains a carboxyl group in the main chain or side chain of the resin. And a resin (also referred to as “carboxylic acid group-containing acid-decomposable resin” or “resin (A)”) whose solubility in an alkaline developer is increased by the action of an acid.
The polymer unit containing a carboxyl group contained in the resin (A) is preferably a repeating unit having a partial structure containing an alicyclic hydrocarbon represented by the following general formula (II) to general formula (V). .

In the formula, R _b101 and R _b102 each independently represent a hydrogen atom, a halogen atom or an alkyl group (preferably having 1 to 4 carbon atoms).
B1 represents a linear, branched or cyclic n + 1 valent organic group (preferably having 1 to 20 carbon atoms) which may have a hetero atom.
n represents an integer of 1 or more. From the viewpoint of the solubility of the resin in the solvent, n is preferably 1 to 3.
R _b103 and R _b104 each independently represent a hydrogen atom, a halogen atom or an alkyl group (preferably having 1 to 10 carbon atoms). R _b103 and R _b104 may be bonded to each other to form a ring.
R _b105 is a monovalent organic group selected from at least one of a hydrogen atom, a linear alkyl group (preferably having 1 to 10 carbon atoms), an acid-decomposable group, a group having a lactone structure, or a hydroxyadamantyl group. Represents.

_As the acid-decomposable group for R _b105 , groups represented by general formulas (pI) to (pIV) shown below are preferable.

In the formula, R ₁₁ represents a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group or a sec-butyl group, and Z forms an alicyclic hydrocarbon group together with a carbon atom. Represents the atomic group necessary to do.
R _{12 to} R ₁₆ each independently represents an alkyl group (preferably having 1 to 4 carbon atoms) or an alicyclic hydrocarbon group, provided that at least one of R _{12 to} R ₁₄ , or R ₁₅ , Any of R ₁₆ represents an alicyclic hydrocarbon group.
R _{17 to} R ₂₁ each independently represents a hydrogen atom, an alkyl group (preferably having 1 to 4 carbon atoms) or an alicyclic hydrocarbon group, provided that at least one of R _{17 to} R ₂₁ is a fat Represents a cyclic hydrocarbon group. Further, either R ₁₉ or R ₂₁ represents an alkyl group or an alicyclic hydrocarbon group.

The group having a lactone structure of R _b105 is preferably a group represented by any one of the following general formula (Lc) or the following general formulas (V-1) to (V-5).

In the formula (Lc), Ra ₁ , Rb ₁ , Rc ₁ , Rd ₁ and Re ₁ each independently represent a hydrogen atom or an alkyl group which may have a substituent. m and n each independently represents an integer of 0 to 3, and m + n is 2 or more and 6 or less.
In formulas (V-1) to (V-5), R _{1b to} R _5b each independently represent a hydrogen atom or an optionally substituted alkyl group, cycloalkyl group, alkoxy group, alkoxycarbonyl. Represents a group, an alkylsulfonylimino group or an alkenyl group. Two of R _{1b to} R _5b may combine to form a ring.

R _{1 to} Re ₁ alkyl groups in general formula (Lc) and R _{1b to} R _5b alkyl groups, alkoxy groups, alkoxycarbonyl groups, alkyl groups in general formulas (V-1) to (V-5) Examples of the alkyl group in the sulfonylimino group include linear and branched alkyl groups, which may have a substituent.
In addition, as a substituent which each said group may have, for example, a C1-C4 alkoxy group, a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), C2-C5 Examples include an acyl group, an acyloxy group having 2 to 5 carbon atoms, a cyano group, a hydroxyl group, a carboxy group, an alkoxycarbonyl group having 2 to 5 carbon atoms, and a nitro group.

_As the hydroxyadamantyl group for R _b105 , a group represented by the following formula (VII) is preferable.

In formula (VII), R _{2c to} R _4c each independently represents a hydrogen atom or a hydroxyl group. However, at least one of R _{2c to} R _4c represents a hydroxyl group.

R _b106 and R _b107 each independently represent a hydrogen atom, a cyano group, a halogen atom, or an alkyl group which may have a substituent.
Za represents an atomic group for forming an alicyclic structure containing two bonded carbon atoms (C—C) and substituted with at least one carboxyl group including the substituent.

  The general formula (V) is more preferably the following general formula (VA) or general formula (V-B).

In the formulas (VA) and (VB):
R _{503 to} R ₅₀₆ are each independently a hydrogen atom, a halogen atom, a cyano group, —COOH, —COOR ₅ , a group that decomposes under the action of an acid, —C (═O) —XA′—R _{17 ′} Or an alkyl group or a cyclic hydrocarbon group. However, at least one of R _{503 to} R ₅₀₆ is a carboxyl group or a substituent substituted with a carboxyl group.
Here, R ₅ represents an alkyl group, a cyclic hydrocarbon group, or the following —Y group, which may have a substituent.
X 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.
Further, at least two of R _{503 to} R ₅₀₆ may be bonded to form a ring.
n represents 0 or 1.
R _{17 ′} represents —COOH, —COOR ₅ , —CN, a hydroxyl group, an alkoxy group, —CO—NH—R ₆ , —CO—NH—SO ₂ —R ₆ or the following —Y group.
R ₆ represents an alkyl group or a cyclic hydrocarbon group.
The -Y group;

In the —Y group, R ₂₁ ′ to R ₃₀ ′ each independently represents a hydrogen atom or an alkyl group which may have a substituent. a and b represent 1 or 2;

In the general formulas (pI) to (pIV), the alkyl group in R _{12 to} R ₂₁ represents an alkyl group (preferably having 1 to 4 carbon atoms). Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a t-butyl group.
Further, as the further substituent of the alkyl group, an alkoxy group (preferably having 1 to 4 carbon atoms), a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), acyl group, acyloxy group, cyano group , Hydroxyl group, carboxy group, alkoxycarbonyl group, nitro group and the like.

The alicyclic hydrocarbon group in R _{11 to} R _{21 or} the alicyclic hydrocarbon group formed by Z and a carbon atom may be monocyclic or polycyclic. Specific examples include groups having a monocyclo, bicyclo, tricyclo, tetracyclo structure or the like having 5 or more carbon atoms. The carbon number is preferably 6-30, and particularly preferably 7-25. These alicyclic hydrocarbon groups may have a substituent.
Preferred examples of the alicyclic hydrocarbon group include an adamantyl group, a noradamantyl group, a decalin residue, a tricyclodecanyl group, a tetracyclododecanyl group, a norbornyl group, a cedrol group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. Group, cyclodecanyl group, and cyclododecanyl group. More preferred are an adamantyl group, a decalin residue, a norbornyl group, a cedrol group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecanyl group, and a cyclododecanyl group.
Examples of the substituent that these alicyclic hydrocarbon groups may have include an alkyl group, a substituted alkyl group, a halogen atom, a hydroxyl group, an alkoxy group, a carboxyl group, and an alkoxycarbonyl group. The alkyl group is preferably a lower alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, or a butyl group, and more preferably a substituent selected from the group consisting of a methyl group, an ethyl group, a propyl group, and an isopropyl group. To express. Examples of the substituent of the substituted alkyl group include a hydroxyl group, a halogen atom, and an alkoxy group. Preferred 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.

The carboxyl group that is necessarily contained in the formulas (VA) and (VB) may be substituted at any position as long as it is contained in the substituents of R _{503 to} R ₅₀₆ .

The repeating unit represented by the general formula (II) is preferably acrylic acid or methacrylic acid.
The repeating unit represented by the general formula (III) is most preferably carboxymethyl (meth) acrylate, 4-carboxyl-1-cyclohexyl (meth) acrylate, or 3-carboxyl-1-adamantyl (meth) acrylate.

  Specific examples of the repeating unit represented by the general formula (III) are shown below. (Wherein Rx represents hydrogen, methyl group, trifluoromethyl group)

The repeating unit represented by the general formula (IV) is most preferably mono (2- _{alkyladamantyl} ) maleic acid ester or mono (dialkyl (1-adamantyl) methyl) when R _b105 is an acid-decomposable substituent. Maleate, 2-methyl-1- (2-alkyladamantyl) maleate, 2-methyl-1- (dialkyl (1-adamantyl) methyl) maleate, 3-methyl-1- (2-alkyladamantyl) ) Maleate, 3-methyl-1- (dialkyl (1-adamantyl) methyl) maleate, 2,3-dimethyl-1- (2-alkyladamantyl) maleate, 2,3-dimethyl-1- Dialkyl (1-adamantyl) methyl) maleic acid ester.

Hereinafter, specific examples in the case where R _b105 is an acid-decomposable substituent in the general formula (IV) will be shown. (Wherein Rxa and Rxb each independently represents hydrogen, a methyl group, or a trifluoromethyl group)

Moreover, although the specific example in case _Rb105 is a non-acid-decomposable substituent is shown below by general formula (IV), this invention is not limited to this. (Wherein Rxa and Rxb each independently represents hydrogen, a methyl group, or a trifluoromethyl group)

In the general formula (V), R _b106 and R _b107 each independently represent a hydrogen atom, a cyano group, a halogen atom, or an alkyl group which may have a substituent.
Za represents an atomic group for forming an alicyclic structure containing two bonded carbon atoms (C—C) and substituted with at least one carboxyl group.

Examples of the halogen atom in R _b106 and R _b107 include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom.
The alkyl group in R _b106 , R _b107 and R ₂₁ ′ to R ₃₀ ′ is preferably a linear or branched alkyl group having 1 to 10 carbon atoms, more preferably a linear chain having 1 to 6 carbon atoms. Or a branched alkyl group, 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, or a t-butyl group.
Examples of the further substituent in the above alkyl 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. The alkoxy group is preferably an alkoxy group having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, or a butoxy group. Examples of the acyl group include a formyl group and an acetyl group, and examples of the acyloxy group include an acetoxy group.

The atomic group for forming the alicyclic structure of Za is an atomic group that forms a repeating unit of an alicyclic hydrocarbon substituted with at least one carboxyl group in a resin. An atomic group for forming a bridged alicyclic structure forming a cyclic hydrocarbon repeating unit is preferred.
Examples of the skeleton of the alicyclic hydrocarbon formed include the same alicyclic hydrocarbon groups as R _{11 to} R _{20 in} the general formulas (pI) to (pIV).
The alicyclic hydrocarbon skeleton may have a substituent. Examples of such a substituent include the same groups as R _{503 to} R ₅₀₆ in the general formula (VA) or (VB).
Among the repeating units having the bridged alicyclic hydrocarbon, the repeating unit represented by the general formula (VA) or (VB) is more preferable.

If the repeating unit represented by the general formula (V) has an acid decomposable group, an acid-decomposable group, the -C (= O) -X-A' -R 17 may also be included in the ' , And may have a substituent for Za in the general formula (V).

The acid-decomposable group is a group having a structure represented by, for example, —C (═O) —X ₁ —R ₀ .
In the formula, R ₀ is a tertiary alkyl group such as t-butyl group or 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- An oxocyclohexyl ester group, a 2-methyl-2-adamantyl group, a mevalonic lactone residue and the like can be mentioned. X ₁ has the same meaning as X above.

Examples of the halogen atom in R _{503 to} R ₅₀₆ include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom.
The alkyl group in R ₅ , R ₆ and R _{503 to} R ₅₀₆ is preferably a linear or branched alkyl group having 1 to 10 carbon atoms, more preferably a linear or branched chain having 1 to 6 carbon atoms. A branched alkyl group, 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, or a t-butyl group.
Examples of the cyclic hydrocarbon group in R ₅ , R ₆ , R _{503 to} R ₅₀₆ include a cyclic alkyl group and a bridged hydrocarbon group, and include a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, an adamantyl group, 2-methyl- 2-adamantyl group, norbornyl group, boronyl group, isobornyl group, tricyclodecanyl group, dicyclopentenyl group, nobornane epoxy group, menthyl group, isomenthyl group, neomenthyl group, tetracyclododecanyl group, etc. .
Examples of the ring formed by combining at least two of R _{503 to} R ₅₀₆ include rings having 5 to 12 carbon atoms such as cyclopentene, cyclohexene, cycloheptane, and cyclooctane.
Preferred examples of the alkoxy group for R ₁₇ ′ 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 further substituents in the 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, an acyloxy group, an alkyl group, and a cyclic hydrocarbon group. Can do. 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.
Examples of the alkyl group and cyclic hydrocarbon group include those listed above.
The divalent linking group of A ′ is selected from the group consisting of an alkylene group, a substituted alkylene group, an ether group, a thioether group, a carbonyl group, an ester group, an amide group, a sulfonamide group, a urethane group, and a urea group. Single or a combination of two or more groups may be mentioned.

Various substituents of R ₁₃ ′ to R ₁₆ ′ in the general formula (VA) or the general formula (VB) are atomic groups or groups for forming the alicyclic structure in the general formula (V). It is also a substituent of the atomic group Z for forming a bridged alicyclic structure, and at least one carboxyl group is included in R ₁₃ ′ to R ₁₆ ′.
Specific examples of the repeating unit represented by the general formula (VA) or the general formula (VB) include the following, but the present invention is not limited to these specific examples.

The resin of the present invention is a resin (acid-decomposable resin) that decomposes by the action of an acid and increases its solubility in an alkali developer, and decomposes a group (acid-decomposable group) that decomposes by the action of an acid and becomes alkali-soluble. However, the acid-decomposable group may be contained in any repeating unit contained in the resin.
Examples of the acid-decomposable group include groups represented by -COOA ⁰ and -O-B ⁰ groups. Further Examples of the group containing these, include groups represented by -R ⁰ -COOA ^0, or -Ar-O-B ^0.
Here, A ⁰ is -C (R ⁰¹ ) (R ⁰² ) (R ⁰³ ), -Si (R ⁰¹ ) (R ⁰² ) (R ⁰³ ), -C (R ⁰⁴ ) (R ⁰⁵ ) -O-R ⁰⁶ groups are shown. B ⁰ represents a —A ⁰ or —CO—O—A ⁰ group.
^{R 01, R 02, R 03} , R 04 and R ⁰⁵ may also be different from, and each of the same, represent a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, an aralkyl group or an aryl group, R ⁰⁶ Represents an alkyl group, a cyclic alkyl group or an aryl group. However, at least two of R ^{01 to} R ⁰³ are groups other than hydrogen atoms, and two groups of R ^{01 to} R ⁰³ and R ^{04 to} R ⁰⁶ are bonded to form a ring. Also good. R ⁰ represents a single bond or a divalent or higher valent aliphatic or aromatic hydrocarbon group which may have a substituent, and —Ar— may have a monocyclic or polycyclic substituent. An aromatic group having a valence of 2 or more is shown.

  Here, 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 n-butyl group, a sec-butyl group, or a t-butyl group. Those having 3 to 30 carbon atoms such as propyl group, cyclobutyl group, cyclohexyl group and adamantyl group are preferred, and the alkenyl group has 2 to 4 carbon atoms such as vinyl group, propenyl group, allyl group and butenyl group. Those having 6 to 14 carbon atoms such as phenyl, xylyl, toluyl, cumenyl, naphthyl, and anthracenyl groups are preferable. Examples of the cyclic alkyl group include those having 3 to 30 carbon atoms, specifically, cyclopropyl group, cyclopentyl group, cyclohexyl group, adamantyl group, norbornyl group, boronyl group, tricyclodecanyl group, Examples include a cyclopentenyl group, a nobornane epoxy group, a menthyl group, an isomenthyl group, a neomenthyl group, a tetracyclododecanyl group, and a steroid residue. Examples of the aralkyl group include those having 7 to 20 carbon atoms, which may have a substituent. Examples include a benzyl group, a phenethyl group, and a cumyl group.

  Substituents include hydroxyl groups, halogen atoms (fluorine, chlorine, bromine, iodine), nitro groups, cyano groups, the above alkyl groups, methoxy groups, ethoxy groups, hydroxyethoxy groups, propoxy groups, hydroxypropoxy groups, n -Alkoxy groups such as butoxy group, isobutoxy group, sec-butoxy group, t-butoxy group, alkoxycarbonyl groups such as methoxycarbonyl group, ethoxycarbonyl group, aralkyl groups such as benzyl group, phenethyl group, cumyl group, and aralkyloxy groups Acyl group such as formyl group, acetyl group, butyryl group, benzoyl group, cyanamyl group, valeryl group, acyloxy group such as butyryloxy group, alkenyl group, alkenyl such as vinyloxy group, propenyloxy group, allyloxy group, butenyloxy group, etc. Oxy group, allee above It can be exemplified group, an aryloxy group such as phenoxy group, aryloxycarbonyl group such as benzoyloxy group.

When an ArF excimer laser is used as a light source for exposure, it is preferable to use a group represented by —C (═O) —X ¹ —R ⁰ as a group that is decomposed by the action of an acid. Here, as R ⁰ , tertiary alkyl groups such as t-butyl group and t-amyl group, isobornyl group, 1-ethoxyethyl group, 1-butoxyethyl group, 1-isobutoxyethyl group, 1-cyclohexyloxy Examples include 1-alkoxyethyl group such as ethyl group, alkoxymethyl group such as 1-methoxymethyl group and 1-ethoxymethyl group, tetrahydropyranyl group, tetrahydrofuranyl group, trialkylsilyl group, 3-oxocyclohexyl group and the like. Can do. X ¹ represents an oxygen atom or a sulfur atom, preferably an oxygen atom.

  Examples of the alkali-soluble group include a carboxyl group, a hydroxyl group, and a sulfonic acid group.

  Below, repeating units other than the repeating unit (polymerization unit) which contains the carboxyl group which the carboxylic acid group containing acid-decomposable resin may contain will be described.

  Among the other repeating units that can be contained in the carboxylic acid group-containing acid-decomposable resin according to the present invention, examples of the repeating unit containing an acid-decomposable group include fats represented by the following general formulas (pI) to (pVI). Of the repeating unit having a partial structure containing a cyclic hydrocarbon, the repeating unit represented by the general formula (II-AB), the repeating unit represented by the general formula (V), and the copolymerization component described later, acid decomposable It is preferable to contain at least one repeating unit among repeating units containing a group.

In the formula, R ₁₁ represents a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group or a sec-butyl group, and Z forms an alicyclic hydrocarbon group together with a carbon atom. Represents the atomic group necessary to do.
R _{12 to} R ₁₆ each independently represents a linear or branched alkyl group or alicyclic hydrocarbon group having 1 to 4 carbon atoms, provided that at least one of R _{12 to} R ₁₄ , or Either R ₁₅ or R ₁₆ represents an alicyclic hydrocarbon group.
R _{17 to} R ₂₁ each independently represents a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or an alicyclic hydrocarbon group, provided that at least one of R _{17 to} R ₂₁ Represents an alicyclic hydrocarbon group. Further, either R ₁₉ or R ₂₁ represents a linear or branched alkyl group or alicyclic hydrocarbon group having 1 to 4 carbon atoms.
R _{22 to} R ₂₅ each independently represents a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or an alicyclic hydrocarbon group, provided that at least one of R _{22 to} R ₂₅ Represents an alicyclic hydrocarbon group. R ₂₃ and R ₂₄ may be bonded to each other to form a ring.

In formula (II-AB):
R ₁₁ ′ and R ₁₂ ′ each independently represents a hydrogen atom, a cyano group, a halogen atom, or an alkyl group.
Z ′ represents an atomic group for forming an alicyclic structure which contains two bonded carbon atoms (C—C) and may have a substituent.
The general formula (II-AB) is more preferably the following general formula (II-A) or general formula (II-B).

In formulas (II-A) and (II-B):
R ₁₃ ′ to R ₁₆ ′ each independently represents a hydrogen atom, a halogen atom, a cyano group, —COOR ₅ , a group capable of decomposing by the action of an acid, —C (═O) —XA′—R ₁₇ ′, Or the alkyl group or cyclic hydrocarbon group which may have a substituent is represented.
Here, R ₅ represents an alkyl group, a cyclic hydrocarbon group, or the following —Y group, which may have a substituent.
X 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.
Further, at least two of R ₁₃ ′ to R ₁₆ ′ may be bonded to form a ring.
n represents 0 or 1.
R ₁₇ ′ is —COOR ₅ , —CN, a hydroxyl group, an optionally substituted alkoxy group, —CO—NH—R ₆ , —CO—NH—SO ₂ —R ₆ or the following —Y group Represents.
R ₆ represents an alkyl group or a cyclic hydrocarbon group which may have a substituent. The -Y group;

(In the —Y group, R ₂₁ ′ to R ₃₀ ′ each independently represents a hydrogen atom or an optionally substituted alkyl group. A and b represent 1 or 2.)

In the general formulas (pI) to (pVI), the alkyl group in R _{12 to} R ₂₅ may be substituted or unsubstituted, and is a linear or branched alkyl group having 1 to 4 carbon atoms. Represents. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a t-butyl group.
As further substituents for the above alkyl group, an alkoxy group having 1 to 4 carbon atoms, a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), acyl group, acyloxy group, cyano group, hydroxyl group, alkoxycarbonyl Group, nitro group and the like.
The alicyclic hydrocarbon group in R _{11 to} R _{25 or} the alicyclic hydrocarbon group formed by Z and a carbon atom may be monocyclic or polycyclic. Specific examples include groups having a monocyclo, bicyclo, tricyclo, tetracyclo structure or the like having 5 or more carbon atoms. The carbon number is preferably 6-30, and particularly preferably 7-25. These alicyclic hydrocarbon groups may have a substituent.

Preferred examples of the alicyclic hydrocarbon group include an adamantyl group, a noradamantyl group, a decalin residue, a tricyclodecanyl group, a tetracyclododecanyl group, a norbornyl group, a cedrol group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. Group, cyclodecanyl group, and cyclododecanyl group. More preferred are an adamantyl group, a decalin residue, a norbornyl group, a cedrol group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecanyl group, and a cyclododecanyl group.
Examples of the substituent for these alicyclic hydrocarbon groups include an alkyl group, a substituted alkyl group, a halogen atom, a hydroxyl group, an alkoxy group, a carboxyl group, and an alkoxycarbonyl group. The alkyl group is preferably a lower alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, or a butyl group, and more preferably a substituent selected from the group consisting of a methyl group, an ethyl group, a propyl group, and an isopropyl group. To express. Examples of the substituent of the substituted alkyl group 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.

The structures represented by the general formulas (pI) to (pVI) in the resin can be used for protecting alkali-soluble groups. Examples of the alkali-soluble group include various groups known in this technical field.
Specific examples include a carboxylic acid group, a sulfonic acid group, a phenol group, and a thiol group, and a carboxylic acid group and a sulfonic acid group are preferable.
As the alkali-soluble group protected by the structure represented by the general formulas (pI) to (pVI) in the above resin, the hydrogen atom of the carboxyl group is preferably substituted with the structure represented by the general formula (pI) to (PVI). Structure.

  As the repeating unit having an alkali-soluble group protected by the structure represented by the general formulas (pI) to (pVI), a repeating unit represented by the following general formula (pA) is preferable.

Here, R represents a hydrogen atom, a halogen atom, or a substituted or unsubstituted linear or branched alkyl group having 1 to 4 carbon atoms. A plurality of R may be the same or different.
A is a single bond, an alkylene group, a substituted alkylene group, an ether group, a thioether group, a carbonyl group, an ester group, an amide group, a sulfonamide group, a urethane group, or a urea group. Represents a combination of groups.
Ra represents any group of the above formulas (pI) to (pVI).

  The repeating unit represented by the general formula (pA) is most preferably a repeating unit of 2-alkyl-2-adamantyl (meth) acrylate and dialkyl (1-adamantyl) methyl (meth) acrylate.

  Specific examples of the repeating unit represented by the general formula (pA) are shown below.

In the general formula (II-AB), 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 an atomic group for forming an alicyclic structure which contains two bonded carbon atoms (C—C) and 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 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, or a t-butyl group.
Examples of the further substituent in the above alkyl 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, and examples of the acyloxy group include an acetoxy group.

The atomic group for forming the alicyclic structure of Z ′ is an atomic group that forms a repeating unit of an alicyclic hydrocarbon which may have a substituent in a resin, and among them, a bridged type alicyclic group. An atomic group for forming a bridged alicyclic structure forming a cyclic hydrocarbon repeating unit is preferred.
Examples of the skeleton of the alicyclic hydrocarbon formed include the same alicyclic hydrocarbon groups as R _{11 to} R _{25 in} the general formulas (pI) to (pVI).
The alicyclic hydrocarbon skeleton may have a substituent. Examples of such a substituent include the same groups as R _{503 to} R ₅₀₆ in the general formula (VA) or (VB).
Among the repeating units having the bridged alicyclic hydrocarbon, the repeating unit represented by the general formula (VA) or (VB) is more preferable.

  In the carboxylic acid group-containing acid-decomposable resin according to the present invention, the group capable of decomposing by the action of an acid is the carboxyl group-containing repeating unit, the alicyclic carbonization represented by the general formula (pI) to the general formula (pVI). It can be contained in at least one repeating unit among the repeating unit having a partial structure containing hydrogen, the repeating unit represented by the general formula (II-AB), and the repeating unit of the copolymerization component described later.

The various substituents of R _{503 to} R ₅₀₆ in the general formula (VA) or the general formula (VB) are atomic groups or groups for forming an alicyclic structure in the general formula (II-AB). It is also a substituent of the atomic group Z for forming a bridge type alicyclic structure.
Specific examples of the repeating unit represented by the general formula (VA) or the general formula (VB) include the following, but the present invention is not limited to these specific examples.

It is also preferable to include a repeating unit having a lactone group. Examples of the lactone group include those described above, and a group having a lactone structure may be directly bonded to the main chain.
As the repeating unit having a group having a lactone structure represented by general formula (Lc) or any one of general formulas (V-1) to (V-5), the above general formula (VA) or (V— is R ₅ ones (e.g. -COOR ₅ having a group at least one represented by the general formula (Lc) (V-1) ~ (V -5) of the R ₅₀₃ to R ₅₀₆ in B) And a repeating unit represented by general formula (Lc) or general formulas (V-1) to (V-5)) or a general formula (AI) shown below.

In general formula (AI), R _b0 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms. As a preferable substituent that the alkyl group of R _b0 may have, as a preferable substituent that the alkyl group as R _1b in the general formulas (V-1) to (V-5) may have. What was illustrated previously is mentioned.

Examples of the halogen atom for R _b0 include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R _b0 is preferably a hydrogen atom.
A ′ represents a single bond, an ether group, an ester group, a carbonyl group, an alkylene group, or a divalent group obtained by combining these.
B ₂ represents a group represented by any one of general formula (Lc) and general formulas (V-1) to (V-5).

  Specific examples of the repeating unit having a group having a lactone structure are shown below, but the present invention is not limited thereto.

  The acid-decomposable resin of the present invention may contain a repeating unit having a group represented by the following general formula (VII).

In general formula (VII), R ₂ c to R ₄ c each independently represents a hydrogen atom or a hydroxyl group. However, at least one of R ₂ c to R ₄ c represents a hydroxyl group.
The group represented by the general formula (VII) is preferably a dihydroxy form or a monohydroxy form, and more preferably a dihydroxy form.
As the repeating unit having a group represented by the general formula (VII), at least one of R _{503 to} R _{506 in} the above general formula (VA) or (VB) is the above general formula (VII). Examples thereof include those having a group represented (for example, R _{5 in} —COOR ₅ represents a group represented by General Formula (VII)), or a repeating unit represented by the following General Formula (AII).

In general formula (AII), R ₁ c represents a hydrogen atom or a methyl group.
R ₂ c to R ₄ c each independently represents a hydrogen atom or a hydroxyl group. However, at least one of R ₂ c to R ₄ c represents a hydroxyl group. _{Two of} R ₂ c to R ₄ c are preferably hydroxyl groups.
Although the specific example of the repeating unit which has a structure represented by general formula (AII) below is given, it is not limited to these.

  The carboxylic acid group-containing acid-decomposable resin of the present invention may contain a repeating unit represented by the following general formula (VIII).

In the general formula (VIII), Z ₂ represents —O— or —N (R ₄₁ ) —. Here, R ₄₁ represents a hydrogen atom, a hydroxyl group, an alkyl group, or —OSO ₂ —R ₄₂ . R ₄₂ represents an alkyl group, a cycloalkyl group or a camphor residue.

  Specific examples of the repeating unit represented by the general formula (VIII) include the following [I′-1] to [I′-7], but the present invention is not limited to these specific examples. .

  In addition to the above repeating structural units, the carboxylic acid group-containing acid-decomposable resin of the present invention includes dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and resolving power, which is a general necessary characteristic of resist, Further, various other repeating structural units can be contained for the purpose of adjusting heat resistance, sensitivity, and the like.

Examples of such repeating structural units include, but are not limited to, repeating structural units corresponding to the following monomers.
Thereby, the performance required for the carboxylic acid group-containing acid-decomposable resin,
(1) Solubility in coating solvent,
(2) Film formability (glass transition point),
(3) Alkali developability,
(4) Membrane slip (hydrophobic, alkali-soluble group selection),
(5) Adhesion of unexposed part to substrate,
(6) Dry etching resistance,
Etc. can be finely adjusted.
As such a monomer, for example, a compound having one addition polymerizable unsaturated bond selected from acrylic acid esters, methacrylic acid esters, acrylamides, methacrylamides, allyl compounds, vinyl ethers, vinyl esters, etc. Etc.

  In addition, any addition-polymerizable unsaturated compound that can be copolymerized with monomers corresponding to the above various repeating structural units may be copolymerized.

  In the carboxylic acid group-containing acid-decomposable resin, the content molar ratio of each repeating structural unit is the resist dry etching resistance, the standard developer suitability, the substrate adhesion, the resist profile, and the resolving power, which is a general required performance of the resist, It is appropriately set for adjusting heat resistance, sensitivity, and the like.

Preferred embodiments of the carboxylic acid group-containing acid-decomposable resin of the present invention include the following.
(1) Containing a repeating unit having a partial structure containing an alicyclic hydrocarbon represented by the general formulas (pI) to (pVI) (side chain type)
(2) Containing repeating units represented by general formulas (V) and (II-AB) (main chain type)
However, in (2), for example, the following can be further mentioned.
(3) A repeating unit represented by the general formulas (V) and (II-AB), a maleic anhydride derivative and a (meth) acrylate structure (hybrid type)

  In the carboxylic acid group-containing acid-decomposable resin, the content of the repeating unit having an acid-decomposable group is preferably 10 to 70 mol%, more preferably 20 to 65 mol%, still more preferably 25 to 25 mol in all repeating structural units. 60 mol%.

In the carboxylic acid group-containing acid-decomposable resin, the content of the repeating unit having a partial structure containing an alicyclic hydrocarbon represented by general formulas (pI) to (pVI) is 20 to 70 mol in all repeating structural units. % Is preferable, more preferably 24 to 65 mol%, still more preferably 28 to 60 mol%.
In the carboxylic acid group-containing acid-decomposable resin, the content of the repeating unit represented by the general formula (II-AB) is preferably 10 to 60 mol%, more preferably 15 to 55 mol% in all repeating structural units. More preferably, it is 20-50 mol%.

  In the carboxylic acid group-containing acid-decomposable resin, the content of repeating units containing a carboxyl group that is necessarily contained is preferably 0.5 to 20 mol%, more preferably 1 to 18 mol% of all repeating units. More preferably, it is 1 to 15 mol%.

  In addition, the content of the repeating structural unit based on the monomer of the further copolymer component in the resin can also be appropriately set according to the performance of the desired resist. ) To (pVI) with respect to the total number of moles of the repeating structural unit having a partial structure containing an alicyclic hydrocarbon and the repeating units represented by the above general formulas (V) and (II-AB). 99 mol% or less is preferable, more preferably 90 mol% or less, still more preferably 80 mol% or less.

  When the composition of the present invention is for ArF exposure, the resin preferably has no aromatic group from the viewpoint of transparency to ArF light.

  The carboxylic acid group-containing acid-decomposable resin used in the present invention can be synthesized according to a conventional method (for example, radical polymerization). For example, as a general synthesis method, monomer species are charged into a reaction vessel in a batch or in the course of reaction, and this is added to a reaction solvent, for example, cyclic ethers such as tetrahydrofuran and 1,4-dioxane, methyl ethyl ketone, methyl isobutyl. Ketones, ketones such as cyclohexanone, and the composition of the present invention such as propylene glycol monomethyl ether acetate and propylene glycol monomethyl ether, which will be described later, are uniformly dissolved in a solvent, and then inert gas such as nitrogen or argon. Polymerization is started using a commercially available radical initiator (azo initiator, peroxide, etc.) as necessary under an atmosphere. If desired, an initiator is added or added in portions, and after completion of the reaction, it is put into a solvent and a desired polymer is recovered by a method such as powder or solid recovery. The concentration of the reaction is 10% by mass or more, preferably 15% by mass or more, and more preferably 20% by mass or more. The reaction temperature is 10 ° C to 150 ° C, preferably 30 ° C to 130 ° C, more preferably 50 ° C to 110 ° C.

The repeating structural units represented by the above specific examples may be used singly or in combination.
In the present invention, the resins may be used alone or in combination.

The weight average molecular weight of the resin according to the present invention is preferably 1,000 to 200,000, more preferably 3,000 to 20,000, as a polystyrene converted value by the GPC method. It is preferable that the weight average molecular weight is in the above range in order to achieve both heat resistance and dry etching resistance and developability and film forming property.
The molecular weight distribution is usually 1 to 5, preferably 1 to 4, more preferably 1 to 3. Setting the molecular weight distribution within the above range is preferable in terms of resolution, resist shape, roughness of the resist pattern side wall, and roughness.

  In the positive resist composition of the present invention, the blending amount of all the resins according to the present invention in the entire composition is preferably 40 to 99.99% by mass, more preferably 50 to 99.97, based on the total solid content of the resist. % By mass.

(B) Epoxy compound (component B)
The epoxy compound of the present invention is represented, for example, by the general formula (EP).

Wherein, R _ep1, R _ep2 each independently represent a hydrogen atom, a methyl group or an ethyl group, R _ep3, R _ep4 each independently represent a hydrogen atom, a halogen atom, a cyano group, a nitro group, a hydroxyl group, an alkyl group Represents a monovalent organic group such as an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyloxy group, an allyl group or an aromatic group. Also, may form a ring by bonding R _ep3 and R _ep4, R _ep1 or R _ep2 and R _ep3 or R _ep4 may combine with each other to form a ring.

  In order to maximize the effect of the present invention, a polyfunctional epoxy compound is preferable, and a bifunctional epoxy compound is more preferable. A polyfunctional epoxy compound is represented, for example by general formula (EP-I).

In the formula, Aep is an n-valent organic group, and n represents an integer of 2 or more. R _ep6 and R _ep7 each independently represent a hydrogen atom, a methyl group or an ethyl group, and R _ep5 represents a hydrogen atom, a halogen atom, a cyano group, a nitro group, a hydroxyl group, an alkyl group, an alkoxy group, an alkoxycarbonyl group, an alkyl group. Represents a monovalent organic group such as a carbonyloxy group, an allyl group or an aromatic group. Also, may form a ring by bonding R _EP6 and R _EP7, by bonding R _EP6 or R _EP7 and R _EP5 or Aep may form a ring.

  The bifunctional epoxy compound is represented by the general formula (EP-II).

In the formula, Aep ₁ is a single bond or a divalent organic group. R _ep8 , R _ep9 , R _ep11 , R _ep12 each independently represent a hydrogen atom, a methyl group or an ethyl group, and R _ep10 , R _ep13 represent a hydrogen atom, a halogen atom, a cyano group, a nitro group, a hydroxyl group, Represents a monovalent organic group such as an alkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyloxy group, an allyl group, an aromatic group. In addition, any of R _ep8 to R _ep13 and Aep ₁ may be bonded to form a ring.

  Of the bifunctional epoxy compounds, most preferred are those represented by the general formula (I).

In the formula, R _a101 , R _a102 , R _a103 and R _a104 each independently represent a hydrogen atom, a methyl group or an ethyl group, and A ₁ represents a single bond or a divalent organic group.

Examples of the divalent organic group in A ₁ and Aep ₁ include, for example, a saturated or unsaturated linear or branched alkylene group having 1 to 20 carbon atoms, and a divalent alicyclic organic group having 3 to 20 carbon atoms. And a divalent aromatic organic group having 6 to 20 carbon atoms. These divalent organic groups may have a hetero atom or a functional group in the chain, in the ring, or at the terminal, and examples of the hetero atom include an oxygen atom, a sulfur atom, and a nitrogen atom. Examples of the group include a carbonyl group. These organic groups may further have a substituent, and further substituents that may be included include a hydroxyl group, a halogen atom, a carboxyl group, an alkoxy group, an acyl group, a cyano group, an acyloxy group, and the like. I can give you. Examples of the halogen atom include a chlorine atom, a bromine atom, and an iodine atom. Examples of the alkoxy group include 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. As the acyloxy group, an acetoxy group and the like can be mentioned.

  Hereinafter, although the specific example of the epoxy compound in this invention is shown, it is not limited to this.

  These epoxy compounds can be synthesized by oxidizing unsaturated double bonds with an appropriate oxidizing agent. Specifically, for example, Experimental Chemistry Course Vol. 23, page 237 (4th edition, The Chemical Society of Japan). Ed.) Is exemplified in many. Various commercially available epoxy compounds can also be used.

These epoxy compounds can be used alone or in combination.
The epoxy compound used in the positive resist composition of the present invention preferably has a molecular weight of 100 to 1000.
In the positive resist composition of the present invention, the blending amount of all the epoxy compounds according to the present invention in the entire composition is preferably 0.01 to 10% by mass, more preferably 0.1 to 10% by mass in the total resist solid content. It is 8 mass%, More preferably, it is 0.1-5 mass%.

(3) Photoacid generator The positive resist composition of the present invention includes a compound that decomposes upon irradiation with actinic rays or radiation to generate an acid.
The acid generator used in the present invention can be selected from compounds generally used as an acid generator.
That is, it generates an acid upon irradiation with actinic rays or radiation used for photoinitiators of photocationic polymerization, photoinitiators of photoradical polymerization, photodecolorants of dyes, photochromic agents, or microresists. Known compounds and mixtures thereof can be appropriately selected and used.

  Examples thereof include diazonium salts, phosphonium salts, sulfonium salts, iodonium salts, imide sulfonates, oxime sulfonates, diazodisulfones, disulfones, and o-nitrobenzyl sulfonates.

  Further, a group that generates an acid upon irradiation with these actinic rays or radiation, or a compound in which a compound is introduced into the main chain or side chain of the polymer, for example, US Pat. No. 3,849,137, German Patent No. 3914407. JP, 63-26653, JP, 55-164824, JP, 62-69263, JP, 63-146038, JP, 63-163452, JP, 62-153853, The compounds described in JP-A 63-146029 can be used.

  Furthermore, compounds capable of generating an acid by light described in US Pat. No. 3,779,778, European Patent 126,712 and the like can also be used.

  Preferred compounds among the acid generators include compounds represented by the following general formulas (ZI), (ZII), and (ZIII).

In the above general formula (ZI), R ₂₀₁ , R ₂₀₂ and R ₂₀₃ each independently represents an organic group.
X ⁻ represents a non-nucleophilic anion.
The carbon number of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ is generally 1-30, preferably 1-20.
Two of R _{201 to} R ₂₀₃ may be bonded to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond, or a carbonyl group.

The two of the group formed by bonding of the R ₂₀₁ to R _203, there can be mentioned an alkylene group (e.g., butylene, pentylene).

Specific examples of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ include corresponding groups in the compounds (Z1-1), (Z1-2) and (Z1-3) described later.

In addition, the compound which has two or more structures represented by general formula (ZI) may be sufficient. For example, the general formula at least one of R ₂₀₁ to R ₂₀₃ of a compound represented by (ZI) is, at least one bond with structure of R ₂₀₁ to R ₂₀₃ of another compound represented by formula (ZI) It may be a compound.

  More preferable examples of the (ZI) component include compounds (Z1-1), (Z1-2), and (Z1-3) described below.

Compound (Z1-1) is at least one of the aryl groups R ₂₀₁ to R ₂₀₃ in formula (ZI), arylsulfonium compound, i.e., a compound having arylsulfonium as a cation.

In the arylsulfonium compound, all of R _{201 to} R ₂₀₃ may be an aryl group, or a part of R _{201 to} R ₂₀₃ may be an aryl group, and the rest may be an alkyl group or a cycloalkyl group.

  Examples of the arylsulfonium compound include triarylsulfonium compounds, diarylalkylsulfonium compounds, aryldialkylsulfonium compounds, diarylcycloalkylsulfonium compounds, aryldicycloalkylsulfonium compounds, and the like.

  The aryl group of the arylsulfonium compound is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group. When the arylsulfonium compound has two or more aryl groups, the two or more aryl groups may be the same or different.

  The alkyl group that the arylsulfonium compound has as necessary is preferably a linear or branched alkyl group having 1 to 15 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, sec- Examples thereof include a butyl group and a t-butyl group.

  The cycloalkyl group that the arylsulfonium compound has as necessary is preferably a cycloalkyl group having 3 to 15 carbon atoms, and examples thereof include a cyclopropyl group, a cyclobutyl group, and a cyclohexyl group.

The aryl group, alkyl group, and cycloalkyl group of R _{201 to} R ₂₀₃ are an alkyl group (for example, having 1 to 15 carbon atoms), a cycloalkyl group (for example, having 3 to 15 carbon atoms), an aryl group (for example, having 6 to 6 carbon atoms) 14), an alkoxy group (for example, having 1 to 15 carbon atoms), a halogen atom, a hydroxyl group, a phenylthio group or the like may be used as a substituent. Preferred substituents are linear or branched alkyl groups having 1 to 12 carbon atoms, cycloalkyl groups having 3 to 12 carbon atoms, and alkoxy groups having 1 to 12 carbon atoms, most preferably alkyl having 1 to 4 carbon atoms. Group, an alkoxy group having 1 to 4 carbon atoms. The substituent may be substituted with any one of the three R _{201 to} R ₂₀₃ , or may be substituted with all three. When R _{201 to} R ₂₀₃ are an aryl group, the substituent is preferably substituted at the p-position of the aryl group.

Examples of the non-nucleophilic anion as X ⁻ include a sulfonate anion, a carboxylate anion, a sulfonylimide anion, a bis (alkylsulfonyl) imide anion, and a tris (alkylsulfonyl) methyl anion.

  A non-nucleophilic anion is an anion that has an extremely low ability to cause a nucleophilic reaction, and is an anion that can suppress degradation over time due to an intramolecular nucleophilic reaction. This improves the temporal stability of the photoresist.

  Examples of the sulfonate anion include an aliphatic sulfonate anion, an aromatic sulfonate anion, and a camphor sulfonate anion.

  Examples of the carboxylate anion include an aliphatic carboxylate anion, an aromatic carboxylate anion, and an aralkylcarboxylate anion.

  Examples of the aliphatic group in the aliphatic sulfonate anion include, for example, an alkyl group having 1 to 30 carbon atoms, specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, sec- Butyl, pentyl, neopentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl And an eicosyl group and a cycloalkyl group having 3 to 30 carbon atoms, specifically, a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, an adamantyl group, a norbornyl group, a boronyl group, and the like.

  The aromatic group in the aromatic sulfonate anion is preferably an aryl group having 6 to 14 carbon atoms, such as a phenyl group, a tolyl group, and a naphthyl group.

  The alkyl group, cycloalkyl group, and aryl group in the aliphatic sulfonate anion and aromatic sulfonate anion may have a substituent.

  Examples of such substituents include nitro groups, halogen atoms (fluorine atoms, chlorine atoms, bromine atoms, iodine atoms), carboxyl groups, hydroxyl groups, amino groups, cyano groups, and alkoxy groups (preferably having 1 to 5 carbon atoms). ), A cycloalkyl group (preferably 3 to 15 carbon atoms), an aryl group (preferably 6 to 14 carbon atoms), an alkoxycarbonyl group (preferably 2 to 7 carbon atoms), an acyl group (preferably 2 to 12 carbon atoms). ), An alkoxycarbonyloxy group (preferably having 2 to 7 carbon atoms), an alkylthio group (preferably having 1 to 15 carbon atoms), and the like. About the aryl group and ring structure which each group has, an alkyl group (preferably C1-C15) can further be mentioned as a substituent.

  Examples of the aliphatic group in the aliphatic carboxylate anion include those similar to the aliphatic group in the aliphatic sulfonate anion.

  Examples of the aromatic group in the aromatic carboxylate anion include the same aromatic groups as in the aromatic sulfonate anion.

  The aralkyl group in the aralkyl carboxylate anion is preferably an aralkyl group having 6 to 12 carbon atoms, such as a benzyl group, a phenethyl group, a naphthylmethyl group, a naphthylethyl group, and a naphthylmethyl group.

  The aliphatic group, aromatic group and aralkyl group in the aliphatic carboxylate anion, aromatic carboxylate anion and aralkylcarboxylate anion may have a substituent. Examples of the substituent include aliphatic sulfonic acid The same halogen atom, alkyl group, cycloalkyl group, alkoxy group, alkylthio group and the like as in the anion can be exemplified.

  Examples of the sulfonylimide anion include saccharin anion.

  The alkyl group in the bis (alkylsulfonyl) imide anion and tris (alkylsulfonyl) methyl anion is preferably an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, An isobutyl group, a sec-butyl group, a pentyl group, a neopentyl group, and the like can be given. These alkyl groups may have a substituent, and examples of the substituent include a halogen atom, an alkyl group substituted with a halogen atom, an alkoxy group, an alkylthio group, and the like, which are substituted with a fluorine atom. Alkyl groups are preferred.

  Examples of other non-nucleophilic anions include fluorinated phosphorus, fluorinated boron, and fluorinated antimony.

Examples of the non-nucleophilic anion of X ⁻ include an aliphatic sulfonate anion in which the α-position of the sulfonic acid is substituted with a fluorine atom, an aromatic sulfonate anion substituted with a fluorine atom or a group having a fluorine atom, and an alkyl group. A bis (alkylsulfonyl) imide anion substituted with a fluorine atom and a tris (alkylsulfonyl) methide anion wherein an alkyl group is substituted with a fluorine atom are preferred. The non-nucleophilic anion is particularly preferably a perfluoroaliphatic sulfonic acid anion having 4 to 8 carbon atoms, an aromatic sulfonic acid anion having a fluorine atom, most preferably a nonafluorobutanesulfonic acid anion, a perfluorooctanesulfonic acid anion, It is a pentafluorobenzenesulfonic acid anion and 3,5-bis (trifluoromethyl) benzenesulfonic acid anion.

Next, the compound (Z1-2) will be described.
The compound (Z1-2) is a compound when R _{201 to} R ₂₀₃ in the general formula (ZI) each independently represents an organic group not containing an aromatic ring. Here, the aromatic ring includes an aromatic ring containing a hetero atom.

The organic group having no aromatic ring as R ₂₀₁ to R ₂₀₃ generally has 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms.

R _{201 to} R ₂₀₃ are each independently preferably an alkyl group, a cycloalkyl group, an allyl group, or a vinyl group, more preferably a linear, branched, cyclic 2-oxoalkyl group, or an alkoxycarbonylmethyl group, most preferably Is a linear, branched 2-oxoalkyl group.

The alkyl group as R _{201 to} R ₂₀₃ may be either linear or branched, and is preferably a linear or branched alkyl group having 1 to 10 carbon atoms, such as a methyl group, an ethyl group, or a propyl group. Butyl group, pentyl group and the like. More preferable examples of the alkyl group include a 2-linear or branched oxoalkyl group and an alkoxycarbonylmethyl group.

The cycloalkyl group as R ₂₀₁ to R ₂₀₃ is preferably a cycloalkyl group having 3 to 10 carbon atoms, e.g., cyclopentyl, cyclohexyl group and a norbornyl group. More preferred examples of the cycloalkyl group include a 2-oxocycloalkyl group.

  The 2-oxoalkyl group may be linear, branched or cyclic, and preferably includes a group having> C = O at the 2-position of the above alkyl group or cycloalkyl group.

  The alkoxy group in the alkoxycarbonylmethyl group is preferably an alkyl group having 1 to 5 carbon atoms (methyl group, ethyl group, propyl group, butyl group, pentyl group).

R _{201 to} R ₂₀₃ may be further substituted with a halogen atom, an alkoxy group (for example, having 1 to 5 carbon atoms), a hydroxyl group, a cyano group, or a nitro group.

Two members out of R _{201 to} R ₂₀₃ may combine to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond, or a carbonyl group. The two of the group formed by bonding of the R ₂₀₁ to R _203, there can be mentioned an alkylene group (e.g., butylene, pentylene).

  The compound (Z1-3) is a compound represented by the following general formula (Z1-3), and is a compound having a phenacylsulfonium salt structure.

R _{1c to} R _5c each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group or a halogen atom.
R _6c and R _7c represent a hydrogen atom, an alkyl group, or a cycloalkyl group.
Rx and Ry each independently represents an alkyl group, a cycloalkyl group, an allyl group or a vinyl group.

Any two or more of R _{1c to} R _5c , and R _x and R _y may be bonded to each other to form a ring structure, and this ring structure includes an oxygen atom, a sulfur atom, an ester bond, and an amide bond. May be included.

Zc ⁻ represents a non-nucleophilic anion, and examples thereof include the same as the non-nucleophilic anion of X ^{− in} formula (ZI).

The alkyl group as R _{1c to} R _7c is preferably a linear or branched alkyl group having 1 to 20 carbon atoms, such as a methyl group, an ethyl group, a linear or branched propyl group, a linear or branched butyl group, A linear or branched pentyl group can be exemplified.

The cycloalkyl group as R _{1c to} R _7c is preferably a cycloalkyl group having 3 to 8 carbon atoms, and examples thereof include a cyclopentyl group and a cyclohexyl group.

The alkoxy group as R _{1c to} R _{5c may} be linear, branched or cyclic, for example, an alkoxy group having 1 to 10 carbon atoms, preferably a linear or branched alkoxy group having 1 to 5 carbon atoms. (For example, methoxy group, ethoxy group, linear or branched propoxy group, linear or branched butoxy group, linear or branched pentoxy group), C3-C8 cyclic alkoxy group (for example, cyclopentyloxy group, cyclohexyloxy group) ).

Preferably, any one of R _{1c to} R _5c is a linear or branched alkyl group, a cycloalkyl group, or a linear, branched or cyclic alkoxy group, and more preferably the sum of the carbon number of R _{1c to} R _5c is 2 ~ 15. Thereby, solvent solubility improves more and generation | occurrence | production of a particle is suppressed at the time of a preservation | save.

_Examples of the alkyl group and cycloalkyl group as R _x and R _y include the same alkyl groups and cycloalkyl groups as R _{1c to} R _{7c, such} as a 2-oxoalkyl group and a 2-oxocycloalkyl group. An alkoxycarbonylmethyl group is more preferable.

Examples of the 2-oxoalkyl group and 2-oxocycloalkyl group include a group having> C═O at the 2-position of the alkyl group or cycloalkyl group as R _{1c to} R _7c .

Examples of the alkoxy group in the alkoxycarbonylmethyl group include the same alkoxy groups as R _{1c to} R _5c .

Examples of the group formed by combining R _x and R _y include a butylene group and a pentylene group.

R _x and R _y are preferably an alkyl group having 4 or more carbon atoms, more preferably 6 or more, and still more preferably 8 or more.

In formula (ZII), (ZIII), R 204 ~R 207 each independently represents an aryl group, an alkyl group or a cycloalkyl group.

Phenyl group and a naphthyl group are preferred as the aryl group of R ₂₀₄ to R _207, more preferably a phenyl group.

The alkyl group as R ₂₀₄ to R ₂₀₇ is preferably a linear or branched alkyl group having 1 to 10 carbon atoms, for example, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group).

The cycloalkyl group as R ₂₀₄ to R ₂₀₇ is preferably a cycloalkyl group having 3 to 10 carbons, e.g., cyclopentyl, cyclohexyl group and a norbornyl group.

The R ₂₀₄ to R ₂₀₇ are substituents which may have, for example, an alkyl group (for example, 1 to 15 carbon atoms), a cycloalkyl group (for example, 3 to 15 carbon atoms), an aryl group (e.g., 6 carbon atoms 15), alkoxy groups (for example, having 1 to 15 carbon atoms), halogen atoms, hydroxyl groups, phenylthio groups and the like.

X ⁻ represents a non-nucleophilic anion, and examples thereof include the same non-nucleophilic anion as X ^{− in} formula (ZI).

  Preferred examples of the acid generator include compounds represented by the following general formulas (ZIV), (ZV), and (ZVI).

In general formulas (ZIV) to (ZVI), Ar ₃ and Ar ₄ each independently represents an aryl group.

R ₂₀₆ , R ₂₀₇ and R ₂₀₈ are an alkyl group, a cycloalkyl group or an aryl group, and these are the same as the alkyl group, cycloalkyl group or aryl group as R _{204 to} R ₂₀₇ .
A represents an alkylene group, an alkenylene group or an arylene group.

  Among the acid generators, compounds represented by the general formulas (ZI) to (ZIII) are more preferable.

  Among the compounds that generate an acid upon irradiation with actinic rays or radiation, examples of particularly preferable compounds are listed below.

An acid generator can be used individually by 1 type or in combination of 2 or more types.
In the positive resist composition of the present invention, the blending amount of all the photoacid generators according to the present invention in the entire composition is preferably 0.1 to 20% by mass, more preferably 0, based on the total resist solid content. It is 5-15 mass%, More preferably, it is 1-15 mass%. Moreover, a photo-acid generator may be used independently and may use multiple types together.

(4) A dissolution inhibiting compound having a molecular weight of 3000 or less (hereinafter also referred to as a “dissolution inhibiting compound”) that decomposes by the action of an acid and increases the solubility in an alkaline developer.
As a dissolution inhibiting compound having a molecular weight of 3000 or less, which is decomposed by the action of an acid to increase the solubility in an alkaline developer, it does not decrease the permeability of 220 nm or less, and is described in Proceeding of SPIE, 2724, 355 (1996). An alicyclic or aliphatic compound containing an acid-decomposable group such as a cholic acid derivative containing an acid-decomposable group is preferred. Examples of the acid-decomposable group and alicyclic structure are the same as those described above for the carboxylic acid group-containing acid-decomposable resin.

The molecular weight of the dissolution inhibiting compound in the present invention is 3000 or less, preferably 300 to 3000, and more preferably 500 to 2500.
The addition amount of the dissolution inhibiting compound is preferably 1 to 30% by mass and more preferably 2 to 20% by mass with respect to the solid content of the positive resist composition.

  Specific examples of the dissolution inhibiting compound are shown below, but are not limited thereto.

(5) Basic compound The positive resist composition of the present invention is a base for reducing the change in performance over time from exposure to heating, or for controlling the diffusibility of an acid generated by exposure from a photoacid generator. It is preferable to contain a functional compound.
Preferable structures include structures represented by the following formulas (A) to (E).

Here, R ²⁵⁰ , R ²⁵¹ and R ²⁵² may be the same or different, and are a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 1 to 20 carbon atoms, or 6 to 20 carbon atoms. Wherein R ²⁵¹ and R ²⁵² may combine with each other to form a ring.
The alkyl group may be unsubstituted or may have a substituent. Examples of the alkyl group having a substituent include an aminoalkyl group having 1 to 6 carbon atoms and a hydroxyalkyl group having 1 to 6 carbon atoms. preferable.
R ²⁵³ , R ²⁵⁴ , R ²⁵⁵ and R ²⁵⁶ may be the same or different and each represents an alkyl group having 1 to 6 carbon atoms.

  Preferred compounds include substituted or unsubstituted guanidine, substituted or unsubstituted aminopyrrolidine, substituted or unsubstituted pyrazole, substituted or unsubstituted pyrazoline, substituted or unsubstituted piperazine, substituted or unsubstituted aminomorpholine, substituted or An unsubstituted aminoalkylmorpholine, a substituted or unsubstituted piperidine can be mentioned, and more preferable compounds are imidazole structure, diazabicyclo structure, onium hydroxide structure, onium carboxylate structure, trialkylamine structure, aniline structure or pyridine. Examples thereof include a compound having a structure, an alkylamine derivative having a hydroxyl group and / or an ether bond, and an aniline derivative having a hydroxyl group and / or an ether bond.

  Examples of the compound having an imidazole structure include imidazole, 2,4,5-triphenylimidazole, benzimidazole, and the like. The compound having a diazabicyclo structure is 1,4-diazabicyclo [2,2,2] octane, 1,5-diazabicyclo [4,3,0] noner-5-ene, 1,8-diazabicyclo [5,4,0]. Undecar 7-ene. Examples of the compound having an onium hydroxide structure include triarylsulfonium hydroxide, phenacylsulfonium hydroxide, sulfonium hydroxide having a 2-oxoalkyl group, specifically triphenylsulfonium hydroxide, tris (t-butylphenyl) sulfonium. Examples thereof include hydroxide, bis (t-butylphenyl) iodonium hydroxide, phenacylthiophenium hydroxide, and 2-oxopropylthiophenium hydroxide. The compound having an onium carboxylate structure is a compound having an onium hydroxide structure in which the anion moiety is converted to a carboxylate, and examples thereof include acetate, adamantane-1-carboxylate, and perfluoroalkylcarboxylate. Examples of the compound having a trialkylamine structure include tri (n-butyl) amine and tri (n-octyl) amine. Examples of aniline compounds include 2,6-diisopropylaniline and N, N-dimethylaniline. Examples of the alkylamine derivative having a hydroxyl group and / or an ether bond include ethanolamine, diethanolamine, triethanolamine, and tris (methoxyethoxyethyl) amine. Examples of aniline derivatives having a hydroxyl group and / or an ether bond include N, N-bis (hydroxyethyl) aniline.

  These basic compounds are used alone or in combination of two or more. The usage-amount of a basic compound is 0.001-10 mass% normally on the basis of solid content of a positive resist composition, Preferably it is 0.01-5 mass%. The above range is preferable in terms of sensitivity and developability of the non-exposed area.

(6) Fluorine-based and / or silicon-based surfactant The positive resist composition of the present invention preferably further contains (E) a surfactant, and is preferably a fluorine-based and / or silicon-based surfactant (fluorine-based surfactant). It is more preferable to contain any one of surfactants, silicon surfactants, surfactants having both fluorine atoms and silicon atoms, or two or more thereof.

When the photoresist composition used in the immersion exposure of the present invention contains the above-mentioned (E) surfactant, the adhesiveness and the resolution can be improved with good sensitivity and resolution when using an exposure light source of 250 nm or less, particularly 220 nm or less. A resist pattern with few development defects can be provided.
Examples of the fluorine-based and / or silicon-based surfactant include, for example, JP-A No. 62-36663, JP-A No. 61-226746, JP-A No. 61-226745, JP-A No. 62-170950, JP 63-34540 A, JP 7-230165 A, JP 8-62834 A, JP 9-54432 A, JP 9-5988 A, JP 2002-277862 A, US Patent Nos. 5,405,720, 5,360,692, 5,529,881, 5,296,330, 5,436,098, 5,576,143, 5,294,511, 5,824,451 Surfactant can be mentioned, The following commercially available surfactant can also be used as it is.
Examples of commercially available surfactants that can be used include F-top EF301, EF303 (manufactured by Shin-Akita Kasei Co., Ltd.), Florard FC430, 431 (manufactured by Sumitomo 3M Co., Ltd.), MegaFuck F171, F173, F176, F189, R08 (Dainippon Ink Chemical Co., Ltd.), Surflon S-382, SC101, 102, 103, 104, 105, 106 (Asahi Glass Co., Ltd.), Troisol S-366 (Troy Chemical Co., Ltd.), etc. Fluorine type surfactant or silicon type surfactant can be mentioned. Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) can also be used as a silicon-based surfactant.

In addition to the known surfactants described above, surfactants are derived from fluoroaliphatic compounds produced by the telomerization method (also referred to as the telomer method) or the oligomerization method (also referred to as the oligomer method). A surfactant using a polymer having a fluoroaliphatic group can be used. The fluoroaliphatic compound can be synthesized by the method described in JP-A-2002-90991.
As the polymer having a fluoroaliphatic group, a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate and / or (poly (oxyalkylene)) methacrylate is preferable and distributed irregularly. Or may be block copolymerized. Examples of the poly (oxyalkylene) group include a poly (oxyethylene) group, a poly (oxypropylene) group, a poly (oxybutylene) group, and the like, and a poly (oxyethylene, oxypropylene, and oxyethylene group). A unit having different chain lengths in the same chain length, such as a block link) or poly (block link of oxyethylene and oxypropylene) may be used. Furthermore, a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate (or methacrylate) is not only a binary copolymer but also a monomer having two or more different fluoroaliphatic groups, Further, it may be a ternary or higher copolymer obtained by simultaneously copolymerizing two or more different (poly (oxyalkylene)) acrylates (or methacrylates).

Examples of commercially available surfactants include Megafac F178, F-470, F-473, F-475, F-476, and F-472 (Dainippon Ink Chemical Co., Ltd.). Further, a copolymer of an acrylate (or methacrylate) having a C ₆ F ₁₃ group and (poly (oxyalkylene)) acrylate (or methacrylate), an acrylate (or methacrylate) having a C ₆ F ₁₃ group and (poly (oxy) (Ethylene)) acrylate (or methacrylate) and (poly (oxypropylene)) acrylate (or methacrylate) copolymer, acrylate (or methacrylate) and (poly (oxyalkylene)) acrylate having C ₈ F ₁₇ groups (or Copolymer of acrylate (or methacrylate), (poly (oxyethylene)) acrylate (or methacrylate), and (poly (oxypropylene)) acrylate (or methacrylate) having a C ₈ F ₁₇ group List union It can be.

  In the present invention, other surfactants other than fluorine-based and / or silicon-based surfactants can also be used. Specifically, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, polyoxyethylene alkyl ethers such as polyoxyethylene oleyl ether, polyoxyethylene octylphenol ether, polyoxyethylene nonylphenol ether, etc. Sorbitans 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 Te - DOO, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, may be mentioned polyoxyethylene sorbitan tristearate nonionic surfactants of polyoxyethylene sorbitan fatty acid esters such as such.

These surfactants may be used alone or in several combinations.
The amount of fluorine and / or silicon-based surfactant used is preferably 0.0001 to 2% by mass, more preferably 0.001 to 1% by mass, based on the positive resist composition (excluding the solvent). .

(7) Organic solvent The positive resist composition of the present invention is used by dissolving the above components in a predetermined organic solvent.
Examples of the organic solvent that can be used include 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 -Dimethylformamide, dimethylsulfoxide, N-methylpyrrolidone, methoxybutanol, tetrahydrofuran, etc. It can be mentioned.

In this invention, you may use the mixed solvent which mixed the solvent which has a hydroxyl group in a structure, and the solvent which does not have a hydroxyl group as an organic solvent.
Examples of the solvent having a hydroxyl group include ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, ethyl lactate, and the like. Propylene glycol monomethyl ether and ethyl lactate are preferred.
Examples of the solvent having no hydroxyl group include propylene glycol monomethyl ether acetate, ethyl ethoxypropionate, 2-heptanone, γ-butyrolactone, cyclohexanone, butyl acetate, N-methylpyrrolidone, N, N-dimethylacetamide, dimethyl sulfoxide. Among these, propylene glycol monomethyl ether acetate, ethyl ethoxypropionate, 2-heptanone, γ-butyrolactone, cyclohexanone, and butyl acetate are preferable, propylene glycol monomethyl ether acetate, ethyl ethoxypropionate 2-heptanone is more preferable.
The mixing ratio (mass ratio) of the solvent having a hydroxyl group and the solvent having no hydroxyl group is preferably 1/99 to 99/1, more preferably 10/90 to 90/10, and even more preferably 20/80 to 60/40. A mixed solvent containing 50% by mass or more of a solvent having no hydroxyl group is particularly preferable from the viewpoint of coating uniformity.

<Other additives>
If necessary, the resist composition of the present invention may further contain a dye, a plasticizer, a photosensitizer, a compound that promotes solubility in a developer, and the like.
The dissolution accelerating compound for the developer that can be used in the present invention is a low molecular weight compound having a molecular weight of 1,000 or less and having two or more phenolic OH groups or one or more carboxy groups. When it has a carboxy group, an alicyclic or aliphatic compound is preferable.
A preferable addition amount of these dissolution promoting compounds is 2 to 50% by mass, and more preferably 5 to 30% by mass with respect to the resin of the component (A). The above range is preferable from the standpoint of development residue and pattern during development.
Such a phenol compound having a molecular weight of 1000 or less can be easily synthesized by those skilled in the art with reference to the methods described in, for example, JP-A-4-1222938, JP-A-2-28531, US Pat. No. 4,916,210, European Patent 219294, and the like. can do.
Specific examples of alicyclic or aliphatic compounds having a carboxyl group include carboxylic acid derivatives having a steroid structure such as cholic acid, deoxycholic acid, lithocholic acid, adamantane carboxylic acid derivatives, adamantane dicarboxylic acid, cyclohexane carboxylic acid, cyclohexane Examples thereof include, but are not limited to, dicarboxylic acids.

(how to use)
The resist composition of the present invention is used by dissolving the above components in a predetermined organic solvent, preferably the mixed solvent, and applying the solution on a predetermined support as follows.
For example, the resist composition is applied on a substrate (for example, silicon / silicon dioxide coating) used for manufacturing a precision integrated circuit device by an appropriate application method such as a spinner or a coater.
After the application, actinic rays and radiation are irradiated through a predetermined mask, followed by baking and development. In this way, a good pattern can be obtained. Examples of the actinic ray include infrared light, visible light, ultraviolet light, far ultraviolet light, X-ray, electron beam, etc., but preferably far ultraviolet light having a wavelength of 250 nm or less, more preferably 220 nm or less, specifically Specifically, KrF excimer laser (248 nm), ArF excimer laser (193 nm), F ₂ excimer laser (157 nm), X-ray, electron beam, etc., ArF excimer laser and F ₂ excimer laser are most preferable. In the present invention, X-rays and electron beams are also included in the actinic rays.
In the development step, an alkaline developer is used as follows. As an alkaline developer of the resist composition, inorganic hydroxides 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, alcohol amines such as dimethylethanolamine and triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide and the like Alkaline aqueous solutions such as quaternary ammonium salts, cyclic amines such as pyrrole and pihelidine can be used.
Furthermore, alcohols and surfactants can be added in appropriate amounts to the alkaline developer.
The alkali concentration of the alkali developer is usually from 0.1 to 20% by mass.
The pH of the alkali developer is usually from 10.0 to 15.0.

Synthesis example: Synthesis of resin (1)
2-Methyl-acrylic acid 2-oxo-tetrahydro-furan-3-yl ester Dissolved to prepare a 50% solids solution. This was charged into a three-necked flask and heated at 60 ° C. under a nitrogen stream. When the reaction temperature was stabilized, 5 mol% of radical initiator V-60 manufactured by Wako Pure Chemical Industries, Ltd. was added to initiate the reaction. After heating for 6 hours, the reaction mixture was diluted twice with tetrahydrofuran, and then poured into hexane in an amount 5 times that of the reaction solution to precipitate a white powder. This was dissolved again in THF, and the solution was added to 5 times the amount of hexane to precipitate a white powder. The precipitated powder was filtered out and dried to obtain the desired resin (1). When the molecular weight analysis (RI analysis) by GPC of the obtained resin (1) was tried, it was 8700 (weight average) in terms of polystyrene, and the dispersity Mw / Mn was 2.25.

  A resin (16) was synthesized from the resin (2) by the same method. The structure, molecular weight, and dispersity of the synthesized resin are shown below.

Examples 1-18 and Comparative Examples 1-3
<Resist preparation>
Components shown in Table 1 below were dissolved in a solvent to prepare a solution having a solid content concentration of 10% by mass, and this was filtered through a 0.1 μm polyethylene filter to prepare a positive resist solution. The prepared positive resist solution was evaluated by the following method, and the results are shown in Table 1.

<Resist evaluation>
An ARC29A manufactured by Brewer Science Co., Ltd. was uniformly applied as an antireflection film at 78 nm on a silicon wafer by a spin coater, and was heated and dried at 205 ° C. for 60 seconds to form an antireflection film. Thereafter, each positive resist composition immediately after preparation was applied with a spin coater and dried at 120 ° C. for 90 seconds (PB) to form a 300 nm resist film.
This resist film is exposed with an ArF excimer laser stepper (PAS5500 / 1100 NA = 0.75 (2/3 annular illumination) manufactured by ASML) through a mask, and immediately after exposure, heated on a hot plate at 120 ° C. for 90 seconds. (PEB). Further, the resist film was developed with an aqueous 2.38 mass% tetramethylammonium hydroxide solution at 23 ° C. for 60 seconds, rinsed with pure water for 30 seconds, and then dried to obtain a resist pattern.

(Pattern collapse evaluation)
The line width of a 110 nm trench repeat pattern (pitch 240 nm) was measured as a function of multiple exposure doses. Usually, as the exposure amount increases, the line width becomes narrower, and eventually pattern collapse occurs. In this evaluation method, the line width (CDmin) at the exposure amount immediately before the occurrence of pattern collapse due to the decrease in line width was used as an index of pattern collapse. That is, a smaller CDmin means that the pattern does not fall even if the line width becomes narrower, and the pattern is less likely to fall.

(Development defect evaluation)
The number of development defects was measured using a KLA2112 machine (manufactured by KLA Tencor) for the trench repeat pattern obtained by the pattern collapse evaluation (Threshold = 12, Pixel size = 0.39).

Hereinafter, abbreviations in each table are as follows.
EPO-1: cyclohexane-1,2-dicarboxylic acid di (1,2-epoxy-3-propyl) (manufactured by Tokyo Chemical Industry)
EPO-2: 1,7-n-octadiene diepoxide (manufactured by Tokyo Chemical Industry)
EPO-3: Celoxide 3000 (manufactured by Daicel Chemical Industries)
EPO-4: Ethyl glycidyl ether (manufactured by Tokyo Chemical Industry)

PAG-1: Triphenylsulfonium perfluorobutane sulfonate PAG-2: Triphenylsulfonium perfluorooctane sulfonate PAG-3: Diphenyl-p-tolylsulfonium perfluorobutane sulfonate PAG-4: p-t-butylphenyl diphenylsulfonium perfluoro Butanesulfonate PAG-5: pt-cyclohexylphenyldiphenylsulfonium perfluorobutanesulfonate PAG-6: 1- [2- (4-cyclohexylphenyl) -1,1-dimethyl-2-oxoethyl] tetrahydrothiophenium perfluoro Butanesulfonate

N-1: N, N-dibutylaniline N-2: N, N-dipropylaniline N-3: N, N-dihydroxyethylaniline N-4: 2,4,5-triphenylimidazole N-5: 2 , 6-Diisopropylaniline N-6: Hydroxyantipyrine
W-1: MegaFuck F176 (Dainippon Ink Chemical Co., Ltd.) (Fluorine)
W-2: Megafuck R08 (Dainippon Ink Chemical Co., Ltd.)
(Fluorine and silicon)
W-3: Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.)
(Silicon)
W-4: Troisol S-366 (manufactured by Troy Chemical Co., Ltd.)

SL-1: cyclopentanone SL-2: cyclohexanone SL-3: 2-methylcyclohexanone SL-4: propylene glycol monomethyl ether acetate SL-5: ethyl lactate SL-6: propylene glycol monomethyl ether SL-7: 2-heptanone SL-8: γ-butyrolactone SL-9: Propylene carbonate

  As is clear from the above results, the positive resist composition of the present invention has very few development defects and is excellent in a pattern collapse margin, and therefore can be effectively used for forming a fine pattern necessary for manufacturing a semiconductor element. .

Claims (8)

  (A) A chemically amplified positive resist composition containing a carboxyl group-containing resin that increases the solubility in an alkali developer by the action of an acid, and (B) an epoxy compound.   The chemically amplified positive resist composition according to claim 1, wherein the resin (A) has a monocyclic or polycyclic alicyclic hydrocarbon structure.   The chemically amplified positive resist composition according to claim 1 or 2, wherein the ratio of the carboxyl group of the resin (A) to the total polymerization units constituting the resin is 0.5 to 20 mol%.   4. The chemically amplified type according to claim 1, wherein the resin (A) contains at least one repeating unit derived from a polymerization component selected from acrylic acid, methacrylic acid, maleic acid, and maleic acid monoester. Positive resist composition.   The chemically amplified positive resist composition according to claim 1, wherein the epoxy compound (B) is a polyfunctional epoxy compound.   The chemically amplified positive resist composition according to claim 5, wherein the polyfunctional epoxy compound is a bifunctional epoxy compound. The chemically amplified positive resist composition according to claim 6, wherein the bifunctional epoxy compound is a compound represented by the following formula (I).

In the formula, R _a101 , R _a102 , R _a103 and R _a104 each independently represent a hydrogen atom, a methyl group or an ethyl group, and A ₁ represents a divalent organic group.   A pattern forming method comprising: forming a resist film from the resist composition according to claim 1; and exposing and developing the resist film.