JP2006276458A - Positive photoresist composition and pattern forming method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a positive photoresist composition having an improved pattern profile, reduced development defects, and reduced collapse of a resist pattern, to provide a pattern forming method using the composition, and particularly, to provide a positive photoresist composition and a pattern forming method suitable for liquid immersion exposure. <P>SOLUTION: The positive photoresist composition contains: (A) a resin which has a repeating unit having an alicyclic hydrocarbon structure and a repeating unit having a naphthalene structure and the solubility of which to an alkali developing solution is increased by an action of an acid; and (B) a compound which generates an acid by irradiation with active rays or radiation. The pattern forming method is carried out by using the above composition. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a positive resist composition used in a semiconductor manufacturing process such as an IC, a circuit board such as a liquid crystal or a thermal head, and also in a lithography process for other photo applications, and a pattern forming method using the same. It is. In particular, the present invention relates to a positive resist composition suitable for exposure with an immersion projection exposure apparatus using far ultraviolet light having a wavelength of 300 nm or less as a light source, and a pattern forming method using the same.

With the miniaturization of semiconductor elements, the exposure light source has become shorter in wavelength and the projection lens has a higher numerical aperture (high NA). Currently, an exposure machine with NA 0.84 using an ArF excimer laser having a 193 nm wavelength as a light source has been developed. ing. These can be expressed by the following equations as is generally well known.
(Resolving power) = k ₁ · (λ / NA)
(Depth of focus) = ± k ₂ · λ / NA ²
Where λ is the wavelength of the exposure light source, NA is the numerical aperture of the projection lens, and k ₁ and k ₂ are coefficients related to the process.

An exposure machine using a F ₂ excimer laser having a wavelength of 157 nm as a light source has been studied for higher resolution by further shortening the wavelength. Lens materials and resists used in the exposure apparatus for shorter wavelength have been studied. Because the materials used in the process are very limited, it is very difficult to stabilize the manufacturing cost and quality of the apparatus and materials, and the exposure apparatus and resist that have sufficient performance and stability within the required period are not in time. The possibility is coming out.

As a technique for increasing the resolving power in an optical microscope, a so-called immersion method in which a high refractive index liquid (hereinafter also referred to as “immersion liquid”) is filled between a projection lens and a sample is known.
This “immersion effect” means that when λ ₀ is the wavelength of the exposure light in the air, n is the refractive index of the immersion liquid with respect to air, θ is the convergence angle of the light beam, and NA ₀ = sin θ. The above-described resolving power and depth of focus can be expressed by the following equations.
(Resolving power) = k ₁ · (λ ₀ / n) / NA ₀
(Depth of focus) = ± k ₂ · (λ ₀ / n) / NA ₀ ²
That is, the immersion effect is equivalent to using an exposure wavelength having a wavelength of 1 / n. In other words, in the case of a projection optical system with the same NA, the depth of focus can be increased n times by immersion. This is effective for all pattern shapes, and can be combined with a super-resolution technique such as a phase shift method and a modified illumination method which are currently being studied.

Examples of apparatuses in which this effect is applied to transfer of a fine image pattern of a semiconductor element include Patent Document 1 (Japanese Patent Laid-Open No. 57-153433) and Patent Document 2 (Japanese Patent Laid-Open No. 7-220990). There is no discussion of resists suitable for immersion exposure techniques.
Recent progress in immersion exposure technology is described in Non-Patent Document 1 (SPIE Proc 4688, 11 (2002)), Non-Patent Document 2 (J. Vac. Sci. Tecnol. B 17 (1999)), and Patent Document 3 (Japanese Patent Laid-Open No. Hei 10). No. -303114), Patent Document 4 (International Publication WO 2004-068242 pamphlet) and the like. In the case of using an ArF excimer laser as a light source, pure water (refractive index of 1.44 at 193 nm) is considered to be most promising as an immersion liquid in terms of handling safety, transmittance at 193 nm, and refractive index. When an F2 excimer laser is used as a light source, a solution containing fluorine has been studied from the balance between transmittance and refractive index at 157 nm, but a sufficient product has not yet been found in terms of environmental safety and refractive index. It has not been. From the degree of immersion effect and the degree of completeness of the resist, the immersion exposure technique is considered to be installed in the ArF exposure machine earliest.

  Since the resist for KrF excimer laser (248 nm), an image forming method called chemical amplification has been used as an image forming method for a resist in order to compensate for sensitivity reduction due to light absorption. Taking a positive chemical amplification image forming method as an example, the acid generator in the exposed area is decomposed by exposure to generate an acid during exposure, and the generated acid is used as a reaction catalyst in post-exposure baking (PEB). In this image forming method, the alkali-insoluble group is changed to an alkali-soluble group, and the exposed portion is removed by alkali development.

In immersion exposure, it has been pointed out that the resist layer comes into contact with the immersion liquid at the time of exposure, so that the resist layer is altered and components that adversely affect the immersion liquid are exuded from the resist layer. Patent Document 5 (International Publication WO 2004-074937 Pamphlet) describes that resist performance changes by immersing a resist for ArF exposure in water before and after exposure, and points out that this is a problem in immersion exposure. .
When a chemically amplified resist that does not cause lithography problems in normal exposure is exposed to immersion, the pattern profile, development defects, and resist pattern collapse are greatly degraded compared to those in normal dry exposure, and improvement is necessary. It was.

JP-A-57-153433 JP-A-7-220990 JP-A-10-303114 International Publication WO 2004-068242 Pamphlet International Publication WO2004-074937 Pamphlet Proc. SPIE, 2002, Vol. 4688, p. 11 J.Vac.Sci.Tecnol.B 17 (1999)

  An object of the present invention is to provide a positive resist composition having improved pattern profile, development defect, and resist pattern collapse, and a pattern forming method using the same, and is particularly suitable for immersion exposure. It is to provide a composition and a pattern forming method.

  The present invention is a positive resist composition having the following constitution and a pattern forming method using the same, whereby the above object of the present invention is achieved.

(1) (A) a resin having a repeating unit having an alicyclic hydrocarbon structure and a repeating unit having a naphthalene structure, which increases the solubility in an alkali developer by the action of an acid, and (B) irradiation with actinic rays or radiation A positive resist composition comprising a compound capable of generating an acid by.

  (2) The positive resist composition as described in (1), wherein the naphthalene structure is a naphthol structure, a naphthalenecarboxylic acid structure, or a structure that is decomposed by the action of an acid to produce a naphthol structure or a naphthalenecarboxylic acid structure .

  (3) The resin of component (A) has (i) a repeating unit having a lactone group and (ii) a repeating unit having a group having an alicyclic hydrocarbon structure that is eliminated by the action of an acid. The positive resist composition as described in (1) or (2).

(4) The positive resist composition as described in any one of (1) to (3), wherein the resin as the component (A) has a fluorine atom.

  (5) The positive resist composition as described in any one of (1) to (4), which is for immersion exposure.

  (6) A pattern forming method comprising the steps of: forming a resist film from the positive resist composition according to any one of (1) to (5); immersion exposing the resist film; and developing the resist film .

  INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a positive resist composition with improved pattern profile, development defect, and resist pattern collapse, and a pattern forming method using the same, and particularly suitable for immersion exposure. In addition, a pattern forming method can be provided.

Hereinafter, the compounds used in the present invention will be described in detail.
In addition, in the description of the group (atomic group) in this specification, the description which does not describe 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) A resin having a repeating unit having an alicyclic hydrocarbon structure and a repeating unit having a naphthalene structure, which increases the solubility in an alkali developer by the action of an acid
The positive resist composition of the present invention comprises a resin having a repeating unit having an alicyclic hydrocarbon structure and a repeating unit having a naphthalene structure, which increases the solubility in an alkaline developer by the action of an acid (hereinafter referred to as resin (A ))).
Here, a resin having increased solubility in an alkali developer means a group that decomposes with an acid to generate an alkali-soluble group in the main chain or side chain of the resin or both the main chain and side chain (hereinafter referred to as “acid-decomposable”). Resin). Among these, a resin having an acid-decomposable group in the side chain is more preferable. A preferable group as the acid-decomposable group is a group in which a hydrogen atom of —COOH group or —OH group is substituted with a group capable of leaving with an acid. In the present invention, the acid-decomposable group is preferably an acetal or a tertiary ester group.

  Examples of the alicyclic hydrocarbon structure in the present invention include structures having a monocyclo, bicyclo, tricyclo, or tetracyclo skeleton. The carbon number is preferably 6-30, and particularly preferably 7-25.

  As the alicyclic hydrocarbon structure in the present invention, 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, A cyclooctyl group, a cyclodecanyl group, and a cyclododecanyl group can be exemplified. More preferably, an adamantyl group, a decalin residue, a norbornyl group, a cedrol group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecanyl group, a cyclododecanyl group, or a tricyclodecanyl group is preferable.

Examples of the substituent of these alicyclic hydrocarbon structures include an alkyl group, a halogen atom, a hydroxyl group, an alkoxy group, a carboxyl group, or 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, more preferably a methyl group, an ethyl group, a propyl group or an isopropyl 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.
These may be further substituted with a hydroxyl group, a halogen atom or an alkoxy group.

The resin (A) preferably has a repeating unit having a group having an alicyclic hydrocarbon structure that is eliminated by the action of an acid.
The group having an alicyclic hydrocarbon structure that is eliminated by the action of an acid is preferably a group having an alicyclic hydrocarbon structure represented by the following general formula (pI) to general formula (pVI).

(Wherein 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 represents an alicyclic hydrocarbon group together with a carbon atom. Represents the atomic group necessary to form.
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 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.
Further, the further substituent of the alkyl group includes an alkoxy group having 1 to 4 carbon atoms, a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), an acyl group, an acyloxy group, a cyano group, a hydroxyl group, A carboxy group, an alkoxycarbonyl group, a nitro group, etc. can be mentioned.

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 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, more preferably a methyl group, an ethyl group, a propyl group or an isopropyl 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 alkyl group and alkoxy group may further have a substituent. Examples of further substituents on the alkyl group and alkoxy group include a hydroxyl group, a halogen atom, and an alkoxy 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.

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.

  In the resin (A), the group (acid-decomposable group) that is decomposed by the action of an acid is a repeating unit having a partial structure containing an alicyclic hydrocarbon represented by the general formula (pI) to the general formula (pVI). And it can contain in at least 1 sort (s) of repeating unit among the repeating units of other copolymerization components.

  As the repeating unit having a group having an alicyclic hydrocarbon structure that is eliminated by the action of an acid, a repeating unit represented by the following general formula (pA) is preferable.

In the general formula (pA), R represents a hydrogen atom, a halogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms. A plurality of R may be the same or different.
A represents a single bond, an 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, or a combination of two or more groups. Represents. A single bond is preferable.
Rp ₁ represents any group of the general 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 above structural formulas, Rx represents H, CH ₃ , CF ₃ or CH ₂ OH, and Rxa and Rxb each independently represents an alkyl group having 1 to 4 carbon atoms.

The resin (A) of the present invention has a repeating unit having a naphthalene structure. The naphthalene structure is preferably a naphthol structure, a naphthalenecarboxylic acid structure, or a structure that is decomposed by the action of an acid to produce a naphthol structure or a naphthalenecarboxylic acid structure.
Examples of the naphthol structure include a structure in which at least one hydroxyl group is substituted on the naphthalene skeleton.
Examples of the naphthalene carboxylic acid structure include a structure in which at least one carboxyl group is substituted on the naphthalene skeleton.
The naphthalene structure includes a structure in which at least one hydroxyl group is substituted on the naphthalene skeleton and at least one carboxyl group is substituted.
As a structure which decomposes | disassembles by the effect | action of an acid and produces a naphthol structure, in the naphthol structure, the hydrogen atom of the hydroxyl group substituted by the naphthalene skeleton was substituted by the structure shown by general formula (pI)-(pVI), for example. The structure can be mentioned.
As a structure which decomposes | disassembles by the effect | action of an acid and produces | generates a naphthalene carboxylic acid structure, the hydrogen atom of the carboxyl group substituted by the naphthalene skeleton in a naphthalene carboxylic acid structure is shown by general formula (pI)-(pVI), for example. The structure substituted by the structure can be mentioned.

  Specific examples of the naphthol structure and naphthalenecarboxylic acid structure are shown below.

  Specific examples of structures that decompose by the action of an acid to produce a naphthol structure or a naphthalenecarboxylic acid structure are shown below.

  As said X, the thing similar to the group which has an alicyclic hydrocarbon structure shown by general formula (pI)-general formula (pVI) is mentioned.

  Examples of the repeating unit having a naphthalene structure include a repeating unit represented by the following general formula.

Where
R _b0 represents a hydrogen atom, a halogen atom, or a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms. Preferred substituents that the alkyl group represented by R _b0 may have include an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 4 to 7 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, and 1 to 1 carbon atoms. 8 alkoxycarbonyl group, carboxyl group, cyano group and the like. 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.
Np represents a group having a naphthalene structure.

  Hereinafter, although the specific example of the repeating unit which has a naphthalene structure is shown, this invention is not limited to this.

  The resin (A) of the present invention preferably has a repeating unit having a group having a lactone structure (hereinafter also referred to as “repeating unit (a)”).

As the lactone structure, any structure having a lactone structure can be used, but a 5-membered ring or 6-membered ring lactone structure is preferable. The lactone structure portion may or may not have a substituent. Preferred substituents include alkyl groups having 1 to 8 carbon atoms, cycloalkyl groups having 4 to 7 carbon atoms, alkoxy groups having 1 to 8 carbon atoms, alkoxycarbonyl groups having 1 to 8 carbon atoms, carboxyl groups, cyano groups, and the like. Is mentioned.
Preferable lactone structures include lactone structures represented by (LC1-1) to (LC1-12) shown below. These may have the above-mentioned substituent.

  The structure having a lactone structure is preferably a structure represented by the following general formula (I). More preferably, the structure represented by general formula (I ') can be mentioned.

In general formulas (I) and (I ′),
X is, CH _2, oxygen atom, sulfur atom or -C (= O) - represents a.
Lc represents a group that forms a lactone.
Ra ₁ and Ra ₂ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an acyl group, or an acid-decomposable group.
Ra ₃ represents a group having a carboxyl group, an alkyl group, an alkoxy group, an acyloxy group, an alkoxycarbonyl group or an acid-decomposable group.
Any two of Ra _{1 to} Ra ₃ may be bonded to form a ring or an acid-decomposable group.
n represents an integer of 1 or 2.
n ₁ and n ₂ represents an integer of 0 to 3. However, n ₁ + n ₂ is an integer of from 1 to 6.
n ₃ represents an integer of 0 to 3.

The lactone in Lc is the same as the above lactone structure.
Examples of the acyl group in Ra ₁ and Ra ₂ include an acyl group having 2 to 20 carbon atoms, an acyl group having a chain hydrocarbon group such as an acetyl group and a propionyl group, a cyclohexanecarbonyl group, and an adamantanecarbonyl group. And an acyl group having a monocyclic or polycyclic hydrocarbon group. As an alkyl group, a C1-C20 alkyl group is mentioned, Linear or branched chain alkyl groups, such as a methyl group, an ethyl group, a propyl group, a butyl group, an octyl group, a dodecyl group, are mentioned. Examples of the cycloalkyl group include a cycloalkyl group having 3 to 20 carbon atoms, and a monocyclic cycloalkyl group such as a cyclopentyl group and a cyclohexyl group, a polycyclic cyclohexane such as an adamantyl group, a norbornyl group, and a tetracyclodecanyl group. An alkyl group is mentioned. Examples of the acid-decomposable group include groups having a structure in which a hydroxyl group is protected with an acid-decomposable protecting group, such as an acetal group, a ketal group, a silyl ether group, and a tertiary alkyloxycarbonyl group. The acid-decomposable group may substitute a hydrogen atom of the hydroxyl group through a group.
A preferred acid-decomposable group is a group in which hydrogen atoms of two adjacent hydroxyl groups are combined to form a cyclic acetal or cyclic ketal structure, more preferably a 5-membered ring ketal structure, and still more preferably adjacent. A hydrogen atom of two hydroxyl groups is bonded to form a 2,2-dialkyl 1,3-dioxolane structure. Dialkyl groups on oxolane may combine to form a monocyclic or polycyclic structure.
The alkyl group in Ra _{3 and} the alkyl group in Ra ₃ alkoxy group and alkoxycarbonyl group are the same as the above alkyl group.
The acyl group in the acyloxy group of Ra ₃ is the same as the above acyl group.
The any two of the group formed by bonding of ra ₁ to Ra _3, for example, can be mentioned hydrocarbon group having 3 to 20 carbon atoms, which may have an oxygen atom.

  Examples of the repeating unit having a group having a lactone structure represented by any one of the general formulas (LC1-1) to (LC1-12) include a repeating unit represented by the following general formula (AI). .

In general formula (AI), R _b0 represents a hydrogen atom, a halogen atom, or a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms. Preferred substituents that the alkyl group represented by R _b0 may have include an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 4 to 7 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, and 1 to 1 carbon atoms. 8 alkoxycarbonyl group, carboxyl group, cyano group and the like.
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 the general formulas (LC1-1) to (LC1-12).

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

  Examples of the repeating unit having the structure of the general formula (I) include (meth) acrylic acid ester derivatives, (meth) acrylamide derivatives, vinyl ether derivatives, olefin derivatives, and styrene derivatives having the structure of the general formula (I). Preferably it is a (meth) acrylic acid ester derivative, More preferably, it is a repeating unit represented by the following general formula (Ia), More preferably, it is a repeating unit represented by the following general (Ia-1).

In the general formulas (Ia) and (Ia-1),
Rb ₁ represents a hydrogen atom, an alkyl group, or —CH ₂ —O—Rb ₂ . In the formula, Rb ₂ represents a hydrogen atom, an alkyl group, a cycloalkyl group, an acyl group, or a group having a lactone structure.
Rc represents a single bond or a divalent linking group.
X is, CH _2, oxygen atom, sulfur atom or -C (= O) - represents a.
Lc represents a group that forms a lactone.
Ra ₁ and Ra ₂ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an acyl group, or an acid-decomposable group.
Ra ₃ represents a group having a carboxyl group, an alkyl group, an alkoxy group, an acyloxy group, an alkoxycarbonyl group or an acid-decomposable group.
Any two of Ra _{1 to} Ra ₃ may be bonded to form a ring or an acid-decomposable group.
n represents an integer of 1 or 2.
n ₁ and n ₂ represents an integer of 0 to 3. However, n ₁ + n ₂ is an integer of from 1 to 6.
n ₃ represents an integer of 0 to 3.

The alkyl group of Rb ₁ is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, a sec-butyl group, a t-butyl group, etc. Can be mentioned. The alkyl group of Rb ₁ may have a substituent. Examples of the substituent for the alkyl group of Rb ₁ include a fluorine atom, a chlorine atom, and a hydroxyl group.
Examples of the alkyl group in Rb ₂ include alkyl groups having 1 to 20 carbon atoms, and linear or branched chain alkyl such as methyl group, ethyl group, propyl group, butyl group, octyl group, and dodecyl group. Groups. Examples of the cycloalkyl group include a cycloalkyl group having 3 to 20 carbon atoms, and a monocyclic cycloalkyl group such as a cyclopentyl group and a cyclohexyl group, a polycyclic cyclohexane such as an adamantyl group, a norbornyl group, and a tetracyclodecanyl group. An alkyl group is mentioned. Examples of the acyl group include acyl groups having 2 to 20 carbon atoms, monocyclic or polycyclic cyclic groups such as an acyl group having a chain hydrocarbon group such as an acetyl group and a propionyl group, a cyclohexanecarbonyl group, and an adamantanecarbonyl group. The acyl group which has a hydrocarbon group is mentioned.
Examples of the lactone structure in the group having the lactone structure of Rb ₂ include those similar to the lactone structure described above.
Examples of the divalent linking group for Rc include an alkylene group, a cycloalkylene group, —CO ₂ —, or a group in which a plurality of these groups become a linking group.
Alkyl group Rb _2, a cycloalkyl group, an acyl group, a group having a lactone structure rb _2, 2 divalent linking group of Rc may have a substituent. Examples of the substituent for the Rb ₂ alkyl group, cycloalkyl group, acyl group, Rb ₂ lactone group, and Rc divalent linking group include a fluorine atom, a chlorine atom, and a hydroxyl group.
The divalent linking group for Rc is preferably an alkylcarboxyl linking group or a cycloalkylcarboxyl linking group in which an alkylene group or a cycloalkylene group and a —CO ₂ — group are linked, and more preferably a polycyclic cycloalkylcarboxyl linking group. It is. Specific examples include an adamantyl carboxyl linking group and a norbornane carboxyl linking group.
Rc is particularly preferably a single bond. By making Rc a single bond, the glass transition temperature of the resin can be adjusted to an appropriate temperature, and the exposure latitude is improved.

Preferred examples of the repeating unit (Ia) are shown below.
In the following specific examples, it is possible to have a plurality of optical isomers, and a single optical isomer may be used, or a mixture of a plurality of optical isomers may be used. It is preferable to use the optical isomer of

  As the monomer corresponding to the repeating unit (Ia), a monomer represented by the following general formula (Ib) is preferable, and a monomer represented by the following general formula (Ib ′) is more preferable.

In general formulas (Ib) and (Ib ′),
Rb ₁ represents a hydrogen atom, an alkyl group, or —CH ₂ —O—Rb ₂ . In the formula, Rb ₂ represents a hydrogen atom, an alkyl group, a cycloalkyl group, an acyl group, or a group having a lactone structure.
Rc represents a single bond or a divalent linking group.
X is, CH _2, oxygen atom, sulfur atom or -C (= O) - represents a.
Lc represents a group that forms a lactone.
Ra ₁ and Ra ₂ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an acyl group, or an acid-decomposable group.
Ra ₃ represents a group having a carboxyl group, an alkyl group, an alkoxy group, an acyloxy group, an alkoxycarbonyl group or an acid-decomposable group.
Any two of Ra _{1 to} Ra ₃ may be bonded to form a ring or an acid-decomposable group.
n represents an integer of 1 or 2.
n ₁ and n ₂ represents an integer of 0 to 3. However, n ₁ + n ₂ is an integer of from 1 to 6.
n ₃ represents an integer of 0 to 3.

  Specific preferred examples of the monomer corresponding to the repeating unit (Ia) are shown below.

  In the present invention, it is also preferable to have a repeating unit having a group having a lactone structure in which another 5- or 6-membered ring is condensed (hereinafter also referred to as “repeating unit (b)”). The 5- or 6-membered ring formed by condensed ring in the repeating unit (b) may contain a hetero atom such as an oxygen atom or a sulfur atom in the atom forming the ring, or a double bond. Specifically, cyclohexane ring, cyclopentane ring, tetrahydrofuran ring, tetrahydropyran ring, cyclohexene ring, cyclopentene ring, dihydrofuran ring, dihydropyran ring, tetrahydrothiophene ring, dihydrothiophene ring, etc. Is mentioned.

  Examples of the lactone structure in which a 5- or 6-membered ring is condensed include structures represented by the following general formula (II) or (III).

In general formulas (II) and (III),
Lc represents a group that forms a lactone.
Ra ₃ represents a group having a carboxyl group, an alkyl group, an alkoxy group, an acyloxy group, an alkoxycarbonyl group or an acid-decomposable group.
When Ra ₃ is in plurality, any two of the plurality of Ra ₃ may be bonded to each other to form a ring.
X _{1 is, -CH 2 -, - CH 2} CH 2 -, - CH 2 O -, - O -, - S- or represents the -CH ₂ S-.
n ₃ represents an integer of 0 to 3.

Formula (II), (III) in at Lc, Ra _3, n ₃ are the same as the general formula in the _{(I) Lc, Ra 3,} n 3.
As the lactone structure formed by Lc, a 5- or 6-membered ring lactone is preferable.

  Preferred examples of the repeating unit having the structure represented by the general formula (II) or (III) include the repeating units represented by the following general formula (IIa) or (IIIa). A repeating unit in which the α-position is bonded is more preferable.

In general formulas (IIa) and (IIIa),
Rb ₁ represents a hydrogen atom, an alkyl group, or —CH ₂ —O—Rb ₂ . In the formula, Rb ₂ represents a hydrogen atom, an alkyl group, a cycloalkyl group, an acyl group, or a group having a lactone structure.
Rc represents a single bond or a divalent linking group.
Lc represents a group that forms a lactone.
Ra ₃ represents a group having a carboxyl group, an alkyl group, an alkoxy group, an acyloxy group, an alkoxycarbonyl group or an acid-decomposable group.
When Ra ₃ is in plurality, any two of the plurality of Ra ₃ may be bonded to each other to form a ring.
X _{1 is, -CH 2 -, - CH 2} CH 2 -, - CH 2 O -, - O -, - S- or represents the -CH ₂ S-.
n ₃ represents an integer of 0 to 3.

Formula (IIa), in Lc, Ra _3, n ₃ in (IIIa) is the same as the general formula in the _{(I) Lc, Ra 3,} n 3.
Formula (IIa), in Rb _1, Rc in (IIIa) are those formula similar to the in Rb _1, Rc in (Ia).

  More preferred examples of the repeating unit having the structure represented by the general formula (II) or (III) include the repeating unit represented by the following general formula (IIa-1) or (IIIa-1).

In general formulas (IIa-1) and (IIIa-1),
Rb ₁ represents a hydrogen atom, an alkyl group, or —CH ₂ —O—Rb ₂ . In the formula, Rb ₂ represents a hydrogen atom, an alkyl group, a cycloalkyl group, an acyl group, or a group having a lactone structure.
Rc represents a single bond or a divalent linking group.
Ra ₃ represents a group having a carboxyl group, an alkyl group, an alkoxy group, an acyloxy group, an alkoxycarbonyl group or an acid-decomposable group.
When Ra ₃ is in plurality, any two of the plurality of Ra ₃ may be bonded to each other to form a ring.
X ₂ represents a single bond or —CH ₂ —.
X ₃ represents a single bond or —CH ₂ —.
X ₄ represents a single _{bond, -CH 2 -, - CH 2} CH 2 -, - CH 2 O -, - O -, - S- or represents the -CH ₂ S-.
X ₅ is a single _{bond, -CH 2 -, - CH 2} CH 2 -, - CH 2 O -, - O -, - S- or represents the -CH ₂ S-.
The sum of the number of atoms excluding the hydrogen atoms of X ₄ and X ₅ is 1 or 2.
n ₃ represents an integer of 0 to 3.
As a combination of X _{2 to} X ₅ , X _{2 to} X ₄ are single bonds, X ₅ is —CH ₂ —, and X _{2 to} X ₄ are single bonds, and X ₅ is —CH ₂ —CH _2. A combination that is-is preferred.

Formula (IIa-1), in the _{(IIIa-1), Ra 3} , n 3 are the same as the general formula in the _{(I) Ra 3, n 3} .
Formula (IIa-1), in the _{(IIIa-1), Rb 1} , Rc is the general formula similar to the in Rb _1, Rc in (Ia).

  Preferred examples of the repeating unit having a lactone structure represented by the general formula (II) are shown below.

  Preferred examples of the repeating unit having a lactone structure represented by the general formula (III) are shown below.

The monomer corresponding to the repeating unit (IIa) is preferably a monomer represented by the following general formula (IIb) or (IIIb), more preferably the following general formula (IIb ′) or (II
It is a monomer represented by Ib ′).

In the general formula (IIb), (IIIb) Rb 1, Rc, Lc, X 1, Ra 3, n 3 is the general formula (IIa), in Rb ₁ to (IIIa), Rc, Lc, X 1 , Ra ₃ and n ₃ are the same.

In the general formulas (IIb ′) and (IIIb ′), Rb ₁ , Rc, Ra ₃ , n ₃ , X ₂ , X ₃ , X ₄ and X ₅ represent the general formulas (IIa-1) and (IIIa-1) Rb ₁ , Rc, Ra ₃ , n ₃ , X ₂ , X ₃ , X ₄ , X ₅ are the same as those in FIG.

  Hereinafter, although the specific example of a monomer represented by general formula (IIb) is given, this invention is not limited to this.

  Hereinafter, although the specific example of a monomer represented by general formula (IIIb) is given, this invention is not limited to this.

Monomers corresponding to the repeating units (Ia) and (IIa) are obtained by reacting the corresponding hydroxylactone with, for example, (meth) acrylic anhydride, (meth) acrylic chloride, etc. under basic conditions. be able to. Hydroxylactone is described in, for example, the method described in Tetrahedron, (1987), p415; Chem. Soc. PERKIN Trans. 1. (1993), method described in p313, Tetrahedron, (1994), method described in p10265, Org. Chem, (1952), p600, and the like.

  The resin (A) can have a plurality of optical isomers in the repeating unit (Ia) or the repeating unit (IIa), and a single optical isomer may be used, or a plurality of optical isomers may be used. A mixture of isomers may be used, but a single optical isomer is preferably used.

  The resin (A) of the present invention may have 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.

  Examples of the repeating unit having a group represented by the general formula (VII) include 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 resin (A) preferably has a fluorine atom. The repeating unit having a fluorine atom preferably contains at least one of the following general formulas (I) to (II).

In the general formula (I),
R _k1 , R _k2 and R _k3 each independently represent a halogen atom, an alkyl group or an alkoxy group.
la represents an integer of 0 to 2, lb represents an integer of 0 to 6, and lc represents an integer of 0 to 7.
L ₁ represents a single bond or a divalent linking group.
n represents 0 or 1.
Y represents a hydrogen atom or an organic group.

In the general formula (II),
R _{x1 to} R _x3 each independently represent a hydrogen atom, a fluorine atom, a chlorine atom, a cyano group, an alkyl group, or —L ₃ —C (R _f1 ) (R _f2 ) Ra.
R _f1 and R _f2 each independently represent a hydrogen atom, a fluorine atom, or an alkyl group. However, at least one of R _f1 and R _f2 is a fluorine atom or a fluoroalkyl group.
Ra represents a hydrogen atom or a hydroxyl group.
L ₃ represents a single bond, an alkylene group, —CH ₂ —O—, —CH ₂ —COO—.
R ₁ and R _m each independently represents a hydrogen atom or an alkyl group.
Z ₁ represents a single bond, an alkylene group, a cycloalkylene group, or an arylene group.
L ₁ represents a single bond or a divalent linking group.
n and q each independently represents 0 or 1.
r represents an integer of 0-6.
Y represents a hydrogen atom or an organic group.

In the general formula (I),
Examples of the halogen atom for R _k1 , R _k2 and R _k3 include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom is preferred.
The alkyl group as R _k1 , R _k2 and R _k3 may have a substituent and is preferably an alkyl group having 1 to 8 carbon atoms, such as a methyl group, an ethyl group, a propyl group, or an n-butyl group. , Sec-butyl group, t-butyl group and the like. The alkyl group of R _k1 , R _k2 and R _k3 is preferably an alkyl group substituted with a fluorine atom, and the carbon number thereof is 1 to 8, preferably 1 or 2, more preferably 1 carbon. . A perfluoroalkyl group in which all hydrogen atoms of the alkyl group are substituted with fluorine atoms is preferred.
The alkoxy group of R _k1 , R _k2 and R _k3 may have a substituent, and is preferably an alkoxy group having 1 to 8 carbon atoms, such as methoxy group, ethoxy group, propoxy group, n-butoxy group, etc. Can be mentioned.
Examples of the substituent that the alkyl group and alkoxy group as R _k1 , R _k2 and R _k3 may have include an alkoxy group having 1 to 4 carbon atoms, a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, an iodine atom). ), Acyl group, acyloxy group, cyano group, hydroxyl group, carboxy group, alkoxycarbonyl group, nitro group and the like.

R _k1 , R _k2 and R _k3 are preferably a halogen atom or a fluorine-substituted alkyl group, particularly preferably a fluorine atom or a trifluoromethyl group.

  la represents an integer of 0 to 2, lb represents an integer of 0 to 6, and lc represents an integer of 0 to 7. Preferably, la is 0, lb is 0, and lc is an integer of 0 to 3.

Examples of the divalent linking group of L ₁ include an alkylene group, a cycloalkylene group, an alkenylene group, an arylene group, —O—, —S—, —O—R _22a —, —O—C (═O) —. R _22b —, —C (═O) —O—R _22c —, —C (═O) —N (R _22d ) —R _22e — and the like can be mentioned. R _22a , R _22b , R _22c and R _{22e each} may have a single bond or an ether group, an ester group, an amide group, a urethane group or a ureido group, a divalent alkylene group, a cycloalkylene group, an alkenylene. Represents a group or an arylene group. R _22d is a hydrogen atom or an alkyl group (preferably having 1 to 5 carbon atoms), a cycloalkyl group (preferably having 3 to 10 carbon atoms), an aralkyl group (preferably having 7 to 10 carbon atoms), or an aryl group (preferably carbon). Equations 6 to 10) are expressed.
The alkylene group is preferably a linear or branched alkylene group having 1 to 8 carbon atoms, and examples thereof include a methylene group, an ethylene group, a propylene group, a butylene group, a hexylene group, and an octylene group.
The cycloalkylene group is preferably a cycloalkylene group having 5 to 12 carbon atoms, and examples thereof include monocyclic residues such as cyclopentylene group and cyclohexylene group, and polycyclic residues such as normolnan skeleton and adamantane skeleton. be able to.
The alkenylene group is preferably an alkenylene group having 2 to 6 carbon atoms, and examples thereof include an ethenylene group, a propenylene group, and a butenylene group.
The arylene group is preferably an arylene group having 6 to 15 carbon atoms, and examples thereof include a phenylene group, a tolylene group, and a naphthylene group.

Examples of the substituent that the divalent linking group of L ₁ may have include a halogen atom such as a fluorine atom and a chlorine atom, a cyano group, and the like, and a fluorine atom is preferable.
L ₁ is preferably a single bond, a methylene group or an —O— group.

Examples of the alkylene group for X include those having 1 to 8 carbon atoms such as a methylene group, an ethylene group, a propylene group, a butylene group, a hexylene group, and an octylene group.
Examples of the alkenylene group of X include those having 2 to 6 carbon atoms such as ethenylene group, propenylene group and butenylene group.
Examples of the cycloalkylene group represented by X include those having 5 to 8 carbon atoms such as a cyclopentylene group and a cyclohexylene group.
Examples of the arylene group for X include those having 6 to 15 carbon atoms such as a phenylene group, a tolylene group, and a naphthylene group.

The organic group for Y includes both acid-decomposable and non-acid-decomposable ones, and preferably has 1 to 30 carbon atoms. Examples of the acid-decomposable organic group for Y include -C (R _11a ) (R _12a ) (R _13a ), -C (R _14a ) (R _15a ) (OR _16a ), -Xa-COO-C ( R _11a ) (R _12a ) (R _13a ) and the like.
R _{11a to} R _13a and R _16a each independently represents an alkyl group, a cycloalkyl group, an alkenyl group, an aralkyl group or an aryl group.
R _14a and R _15a each independently represents a hydrogen atom or an alkyl group.
Two of R _11a , R _12a , and R _13a and two of R _14a , R _15a , and R _16a may be bonded to form a ring.
Xa represents a single bond, an alkylene group, a cycloalkylene group, an alkenylene group or an arylene group.

As the alkyl group for R _{11a to} R _13a , R _14a , R _15a and R _16a , an alkyl group having 1 to 8 carbon atoms which may have a substituent is preferable, and examples thereof include a methyl group, an ethyl group, Propyl group, n-butyl group, sec-butyl group, hexyl group, 2-ethylhexyl group, octyl group, fluoroalkyl group (monofluoromethyl group, difluoromethyl group, trifluoromethyl group, pentafluoroethyl group, etc.) be able to. Of the fluoroalkyl groups, a trifluoromethyl group is most preferred.
The cycloalkyl group for R _{11a to} R _13a and R _16a may have a substituent, and may be monocyclic or polycyclic. The monocyclic type is preferably a cycloalkyl group having 3 to 8 carbon atoms, and examples thereof include a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, a cyclobutyl group, and a cyclooctyl group. As the polycyclic type, a cycloalkyl group having 6 to 20 carbon atoms is preferable. For example, an adamantyl group, norbornyl group, isobornyl group, camphanyl group, dicyclopentyl group, α-pinel group, tricyclodecanyl group, tetocyclo A dodecyl group, an androstanyl group, etc. can be mentioned. A part of carbon atoms in the cycloalkyl group may be substituted with a hetero atom such as an oxygen atom.

The aryl group of R _{11a to} R _13a and R _16a may have a substituent, and is preferably an aryl group having 6 to 10 carbon atoms. For example, a phenyl group, a tolyl group, a dimethylphenyl group, 2, A 4,6-trimethylphenyl group, a naphthyl group, an anthryl group, a 9,10-dimethoxyanthryl group, etc. can be mentioned.
The aralkyl group of R _{11a to} R _13a and R _16a may have a substituent and is preferably an aralkyl group having 7 to 12 carbon atoms, and examples thereof include a benzyl group, a phenethyl group, and a naphthylmethyl group. Can do.
The alkenyl group of R _{11a to} R _13a and R _16a may have a substituent, and is preferably an alkenyl group having 2 to 8 carbon atoms, such as a vinyl group, an allyl group, a butenyl group, or a cyclohexenyl group. Etc.
The substituents that R _{11a to} R _13a , R _14a , R _15a , and R _16a may have include an alkyl group, a cycloalkyl group, an aryl group, an amino group, an amide group, a ureido group, a urethane group, and a hydroxy group. Carboxy group, halogen atom, alkoxy group, thioether group, acyl group, acyloxy group, alkoxycarbonyl group, cyano group, nitro group and the like.

  Preferred examples of the acid-decomposable group for Y include a t-butyl group, a t-amyl group, a 1-alkyl-1-cyclohexyl group, a 2-alkyl-2-adamantyl group, a 2-adamantyl-2-propyl group, Tertiary alkyl groups such as 2- (4-methylcyclohexyl) -2-propyl group, acetal groups such as 1-alkoxy-1-ethoxy group, 1-alkoxy-1-methoxy group and tetrahydropyranyl group, t-alkyl Preferred examples include a carbonyl group and a t-alkylcarbonylmethyl group.

  The non-acid-decomposable organic group of Y is an organic group that is not decomposed by the action of an acid, for example, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group that is not decomposed by the action of an acid. , Alkoxy groups, alkoxycarbonyl groups, amide groups, cyano groups, and the like. The alkyl group is preferably a linear or branched alkyl group having 1 to 10 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, a sec-butyl group, a hexyl group, or a 2-ethylhexyl group. And octyl group. The cycloalkyl group preferably has 3 to 10 carbon atoms, and examples thereof include a cyclopropyl group, a cyclobutyl group, a cyclohexyl group, and an adamantyl group. The aryl group is preferably an aryl group having 6 to 14 carbon atoms, and examples thereof include a phenyl group, a naphthyl group, and an anthracenyl group. The aralkyl group is preferably an aralkyl group having 6 to 12 carbon atoms, and examples thereof include a benzyl group, a phenethyl group, and a cumyl group. The alkoxy group in the alkoxy group and the alkoxycarbonyl group is preferably an alkoxy group having 1 to 5 carbon atoms, and examples thereof include a methoxy group, an ethoxy group, a propoxy group, an n-butoxy group, and an isobutoxy group.

  Preferred specific examples of the repeating unit represented by the general formula (I) are shown below, but the present invention is not limited thereto.

In the general formula (II),
Examples of the alkyl group of R _{x1 to} R _x3 include the same alkyl groups as Rk _{1 to} Rk ₃ in the general formula (I).
In the case where R _{x1 to} R _x3 are groups represented by -L ₃ -C (R _f1 ) (R _f2 ) Ra;
Examples of the alkyl group for R _f1 and R _f2 include the same alkyl groups as Rk _{1 to} Rk ₃ in the general formula (I).
As the alkylene group for L _3, the same divalent alkylene groups as L ₁ in the above general formula (I) can be exemplified.
As the alkyl group for R ₁ and R _m , an alkyl group having 1 to 3 carbon atoms is preferable, and specific examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, and a fluoroalkyl group. Of the groups, a methyl group is most preferred. As the fluoroalkyl group, those having 1 to 4 carbon atoms are preferable. Specifically, a monofluoromethyl group, a difluoromethyl group, a trifluoromethyl group, a pentafluoroethyl group, a heptafluoropropyl group, a nonafluorobutyl group, etc. However, a trifluoromethyl group is most preferable.
Examples of the alkylene group for Z ₁ include the same as the divalent alkylene group as L ₁ in the general formula (I).
The cycloalkylene group for Z ₁ may have a substituent and may be monocyclic or polycyclic. Examples of the substituent include a hydroxyl group, an alkyl group, an alkoxy group, a halogen atom, and a cyano group. The monocyclic type preferably has 3 to 8 carbon atoms, and examples thereof include a cyclopropylene group, a cyclopentylene group, a cyclohexylene group, a cycloheptylene group, and a cyclooctylene group. The polycyclic type has 6 to 20 carbon atoms, such as adamantyl residue, norbornyl residue, isobornyl residue, camphanyl residue, dicyclopentyl residue, α-pinel residue, tricyclodecanyl residue. Preferred examples include a group, a tetocyclododecyl residue, an androstanyl residue, and the like. Moreover, the carbon atom in said monocyclic or polycyclic cycloalkyl group may be substituted by a hetero atom such as an oxygen atom. As the substituent of the cycloalkylene group, a fluorine atom is preferable. As the cycloalkylene group substituted with a fluorine atom (a cycloalkylene group in which at least one hydrogen atom is substituted with a fluorine atom), for example, a perfluorocyclopropylene group Perfluorocyclopentylene group, perfluorocyclohexylene group, perfluorocycloheptylene group, perfluorocyclooctylene group and the like.
As the arylene group for Z _1, an arylene group having 4 to 20 carbon atoms is preferable, and examples thereof include a phenylene group, a tolylene group, and a naphthylene group.
As the divalent linking group represented by L _1, can be the same as the divalent linking group as L ₁ in formula (I).
Examples of the organic group for Y include the same organic groups as Y in the general formula (I) described above.

  Hereinafter, although the specific example of the repeating unit represented by general formula (II) is given, it is not limited to these.

  The resin (A) of the present invention preferably contains fluorine-containing repeating units represented by the following general formulas (IV) to (IX).

X ₁ represents an oxygen atom or a sulfur atom.
X ₂ represents a methylene group, an oxygen atom or a sulfur atom.
Rx represents a hydrogen atom, a fluorine atom, a chlorine atom, a cyano group, an alkyl group, or a -L ₃ -CRa. L ₃ represents an alkylene _{group, -CH 2 O -, - CH} 2 O (C = O) - represents, Ra represents a hydroxyl group, a lactone group, a fluoroalkyl group.
Rf, Rf ₁ and Rf ₂ each independently represents a group having at least one fluorine atom. Rf ₁ and Rf ₂ may be connected to each other to form a ring having — (CF ₂ ) n ₁ —. n ₁ represents an integer of 1 or more.
j represents an integer of 1 to 3.

In the general formulas (IV) to (IX), examples of the alkyl group include the same alkyl groups as Rk _{1 to} Rk ₃ in the general formula (I), and examples of the alkylene group include the above general formula (I It includes the same ones as divalent alkylene group as L ₁ in).
The lactone group has a lactone structure represented by any one of (LC1-1) to (LC1-12).
As the fluoroalkyl group, those having 1 to 4 carbon atoms are preferable, and specifically, a monofluoromethyl group, a difluoromethyl group, a trifluoromethyl group, a pentafluoroethyl group, a heptafluoropropyl group, a nonafluorobutyl group, Hexafluoroisopropyl group, nonafluoro-t-butyl group, trifluoroisopropyl group and the like can be mentioned.
n1 is an integer greater than or equal to ₁ , Preferably it is 3-6.

  Specific examples of the repeating unit represented by formula (IV) are shown below, but the present invention is not limited to these.

  Specific examples of the repeating unit represented by the general formula (V) are shown below, but the present invention is not limited thereto.

  Specific examples of the repeating unit represented by the general formula (VI) are shown below, but the present invention is not limited thereto.

  Specific examples of the repeating unit represented by formula (VII) are shown below, but the present invention is not limited thereto.

  Specific examples of the repeating unit represented by formula (VIII) are shown below, but the present invention is not limited thereto.

  Specific examples of the repeating unit represented by the general formula (IX) are shown below, but the present invention is not limited thereto.

  The resin (A) of the present invention may contain fluorine-containing repeating units represented by the following general formulas (XI) to (XV).

In the general formulas (XI) to (XIII), R ₀ and R _{1 each} represents a hydrogen atom, a fluorine atom, or an alkyl group, cycloalkyl group, or aryl group which may have a substituent.
R _{2 to} R ₄ represent an alkyl group, a cycloalkyl group, or an aryl group, which may have a substituent. R ₀ and R ₁ , R ₀ and R ₂ , R ₃ and R ₄ may combine to form a ring.

Examples of the alkyl group represented by R _{0 to} R ₄ include the same groups as the fluoroalkyl groups represented by R _{x1 to} R _x3 in the general formula (II).
The cycloalkyl group represented by R _{0 to} R ₄ may have a substituent, and may be monocyclic or polycyclic. The monocyclic type is preferably a cycloalkyl group having 3 to 8 carbon atoms, and examples thereof include a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, a cyclobutyl group, and a cyclooctyl group. As the polycyclic type, a cycloalkyl group having 6 to 20 carbon atoms is preferable. For example, an adamantyl group, norbornyl group, isobornyl group, camphanyl group, dicyclopentyl group, α-pinel group, tricyclodecanyl group, tetocyclo A dodecyl group, an androstanyl group, etc. can be mentioned. A part of carbon atoms in the cycloalkyl group may be substituted with a hetero atom such as an oxygen atom.
The aryl group of R _{0 to} R ₄ may have a substituent, and is preferably an aryl group having 6 to 10 carbon atoms, such as a phenyl group, a tolyl group, a dimethylphenyl group, 2,4,6- Examples thereof include a trimethylphenyl group, a naphthyl group, an anthryl group, and a 9,10-dimethoxyanthryl group.

Hereinafter, although the specific example of the repeating unit represented by general formula (XI)-(XIII) is given, it is not limited to these.

In general formula (XIV), R ₂₃ and R ₂₄ may be the same or different and each represents a hydrogen atom, a halogen atom, a cyano group, an alkyl group, a fluoroalkyl group, or an alkoxy group.
Y represents a hydrogen atom or an organic group.

Examples of the alkyl group for R ₂₃ and R ₂₄ include the same alkyl groups as R _k1 in the above general formula (I).
Examples of the alkoxy group of R ₂₃ and R ₂₄ include the same alkoxy groups as R _k1 in the general formula (I) described above.
Examples of the organic group for Y include the same organic groups as Y in the general formula (I).

  Hereinafter, although the specific example of the repeating unit represented by general formula (XIV) is given, it is not limited to these.

In general formula (XV):
Rx represents a single bond or a divalent alkylene group.
Ry represents a hydrogen atom, a fluorine atom, or an alkyl group.
Y represents a hydrogen atom or an organic group.

In general formula (XV):
The divalent alkylene group represented by Rx is preferably one having 1 to 6 carbon atoms, and more preferably a methylene group, an ethylene group or a propylene group.
Examples of the alkyl group of Ry include the same alkyl groups as R _{x1 to} R _x3 in the general formula (II).
Examples of the organic group for Y include the same organic groups as Y in the general formula (I).

  Hereinafter, although the specific example of the repeating unit represented by general formula (XV) is given, it is not limited to these.

As the repeating unit containing these fluorine atoms, a commercially available one can be used, and it can also be synthesized by a usual method.
For example, the following monomer (IV-a) can be synthesized by esterifying the following compound (a). Compound (a) can also be synthesized from the following compound (b) obtained by Diels-Alder reaction of furan and trifluoromethylacrylic acid.

The resin (A) of the present invention has a dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and general necessary properties of resist, resolving power, heat resistance, sensitivity, in addition to the above-mentioned repeating structural unit. Various repeating structural units can be contained for the purpose of adjusting the above.

Examples of such repeating structural units include, but are not limited to, repeating structural units corresponding to the following monomers.
As a result, the performance required for the resin, in particular, (1) solubility in coating solvents, (2) film-forming properties (glass transition point), (3) alkali developability, (4) film slippage (hydrophobic, alkaline) Fine adjustments such as (selection of soluble group), (5) adhesion of the unexposed part to the substrate, and (6) dry etching resistance are possible.
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 resin (A) of the present invention, the 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 general required performance of the resist, resolving power and heat resistance. It is appropriately set to adjust the property, sensitivity, etc.

  The resin (A) of the present invention includes a repeating unit composed of a monomer containing a fluorine atom, a repeating unit composed of a monomer containing a lactone group, a repeating unit composed of a monomer containing a hydroxyl group, and a repeating unit composed of a monomer containing an acid-decomposable group It is preferable to have a repeating unit of a monomer containing a lactone group containing a fluorine atom, a repeating unit of a monomer containing a hydroxyl group, and a repeating unit of a monomer containing an acid-decomposable group.

In the resin (A) of the present invention, the content of the repeating unit having an alicyclic hydrocarbon structure is preferably 15 to 60 mol%, more preferably 15 to 50 mol%, still more preferably in all repeating structural units. It is 20-40 mol%.
In the resin (A) of the present invention, the content of the repeating unit having a naphthalene structure is preferably 3 to 40 mol%, more preferably 5 to 30 mol%, still more preferably 10 to 25 in all repeating structural units. Mol%.
In the resin (A) of the present invention, the content of the repeating unit having an acid-decomposable group is preferably 15 to 60 mol%, more preferably 15 to 50 mol%, still more preferably 20 to 40 in all repeating structural units. Mol%.
In the resin (A) of the present invention, the content of the repeating unit having a lactone structure is preferably 20 to 80 mol%, more preferably 40 to 70%.

  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), preferably 99 mol% or less, more preferably 90 mol% or less, still more preferably, based on the total number of moles of repeating structural units having a partial structure containing an alicyclic hydrocarbon represented by (pVI). 80 mol% or less.

The 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 this invention, resin (A) can be used individually or in mixture of 2 or more types.

The weight average molecular weight of the resin (A) according to the present invention is 7,000 to 50,000 as a polystyrene conversion value by GPC method, and the dispersity (weight average molecular weight / number average molecular weight, Mw / Mn) is 1. .5 or less is preferable.
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 of 1.5 or less is preferable from the viewpoints of resolution, resist shape and resist pattern side wall roughness, and roughness.

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

(B) Compound that generates an acid upon irradiation with actinic rays or radiation A compound that generates an acid upon irradiation with actinic rays or radiation (hereinafter referred to as “acid generator”) used in the positive resist composition of the present invention. Is described below.
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 (ZI-1), (ZI-2) and (Z 1-3) 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 (ZI) components include compounds (ZI-1), (ZI-2), and (ZI-3) described below.

The compound (ZI-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.

Aryl group, alkyl group of R ₂₀₁ to R _203, cycloalkyl group, an alkyl group (for example, 1 to 15 carbon atoms), a cycloalkyl group (e.g., having from 3 to 15 carbon atoms), an aryl group (for example, 6 to 14 carbon atoms ), An alkoxy group (for example, having 1 to 15 carbon atoms), a halogen atom, a hydroxyl group, a phenylthio group and 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 resist.

  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 (ZI-2) will be described.
Compound (ZI-2) is a compound in the case where R _{201 to} R ₂₀₃ in formula (ZI) each independently represents an organic group having no 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 alkoxy group having 1 to 5 carbon atoms (methoxy group, ethoxy group, propoxy group, butoxy group, pentoxy group).

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

  The compound (ZI-3) is a compound represented by the following general formula (ZI-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 general formulas (ZII) and (ZIII),
R ₂₀₄ to 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 carbon atoms, 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.

  As the acid generator in the present invention, particularly preferably, an anion structure containing an alkyl group having 4 or less carbon atoms substituted with a fluorine atom, a cycloalkyl group substituted with a fluorine atom, or an aromatic group substituted with a fluorine atom; An acid generator having a triarylsulfonium cation structure. Such acid generators are preferably those represented by the following general formulas (B1) to (B3).

In general formulas (B1) to (B3),
Each R ₁ independently represents an alkyl group, an alicyclic hydrocarbon group, a hydroxyl group, a carboxyl group, an alkoxy group or a halogen atom.
y represents 0 or an integer of 1 to 5 independently of each other. When y is an integer of 2 or more, two or more R1s may be the same or different.
Q _{1 to} Q ₄ are each independently substituted with an alkyl group having 4 or less carbon atoms substituted with a fluorine atom, a cycloalkyl group substituted with a fluorine atom, an aryl group substituted with a fluorine atom, or a fluorinated alkyl group. Represents an aryl group.

As the alkyl group for R ₁ , a linear or branched alkyl group having 1 to 15 carbon atoms is preferable, and examples thereof include a methyl group, an ethyl group, a propyl group, an n-butyl group, a sec-butyl group, and a t-butyl group. Can be mentioned.
Examples of the alicyclic hydrocarbon group for R ₁ include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a norbornyl group, an adamantyl group, and the like.
Examples of the alkyl group having 4 or less carbon atoms substituted by a fluorine atom of Q _{1 to} Q ₄ include —CF ₃ , —C ₂ F ₅ , —n—C ₃ F ₇ , —CF (CF ₃ ) ₂ , _{-CH (CF 3) 2, -} (CF 2) 2 OCF 2 CF 3, - (CF 2) 2 O (CH 2) 3 CH 3, - (CF 2) 2 O (CH 2) 13 CH 3, - _{(CF 2) 2 O (CF} 2) 2 (CH 2) 3 CH 3 and the like. The alkyl group having 4 or less carbon atoms substituted with a fluorine atom of Q _{1 to} Q ₄ may further have a substituent such as an alkoxy group or a fluoroalkoxy group.
Examples of the aryl group substituted with a fluorine atom of Q _{1 to} Q ₄ include 2,3,4,5,6-pentafluorophenyl group, 2,3,4-trifluorophenyl group, and 2,4-difluoro. A phenyl group, 4-fluorophenyl group, 4-undecanyloxy-2,3,5,6-tetrafluorophenyl group and the like can be mentioned.
Examples of the aryl group substituted with a fluorinated alkyl group of Q _{1 to} Q ₄ include a 3-trifluoromethylphenyl group, a 3,5-bis (trifluoromethyl) phenyl group, a 4-trifluoromethylphenyl group, And 4-n-nonafluorobutylphenyl group.

  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.
The content of the acid generator in the positive resist composition is preferably 0.1 to 20% by mass, more preferably 0.5 to 10% by mass, still more preferably, based on the total solid content of the positive resist composition. Is 1-7 mass%.

(C) A dissolution inhibiting compound having a molecular weight of 3000 or less (hereinafter also referred to as a “dissolution inhibiting compound”) that is decomposed by the action of an acid to increase the solubility in an alkaline developer.
The positive resist composition of the present invention contains a dissolution inhibiting compound having a molecular weight of 3000 or less (hereinafter also referred to as “dissolution inhibitor”) that decomposes by the action of an acid and increases the solubility in an alkaline developer. Is preferred.
As a dissolution inhibitor, a fat containing an acid-decomposable group such as a cholic acid derivative containing an acid-decomposable group described in Proceeding of SPIE, 2724, 355 (1996) is used in order not to lower the permeability of 220 nm or less. Cyclic or aliphatic compounds are preferred. Examples of the acid-decomposable group and alicyclic structure are the same as those described for the resin as the component (A).
The molecular weight of the dissolution inhibitor in the present invention is 3000 or less, preferably 300 to 3000, and more preferably 500 to 2500.

  The addition amount of the dissolution inhibitor is preferably 1 to 30% by mass, more preferably 2 to 20% by mass, based on the total solid content of the positive resist composition.

  Although the specific example of a dissolution inhibitor is shown below, it is not limited to these.

(D) Basic compound The positive resist composition of the present invention preferably contains (D) a basic compound in order to reduce a change in performance over time from exposure to heating.
The basic compound preferably has a structure represented by the following formulas (A) to (E).

Here, R ²⁰⁰ , R ^201, and R ²⁰² 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 ²⁰¹ and R ²⁰² may be bonded to 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 20 carbon atoms, a hydroxyalkyl group having 1 to 20 carbon atoms, Or a C1-C20 cyanoalkyl group is preferable.
R ²⁰³ , R ²⁰⁴ , R ²⁰⁵ and R ²⁰⁶ may be the same or different and each represents an alkyl group having 1 to 6 carbon atoms.
The alkyl groups in the general formulas (A) to (E) are more preferably unsubstituted.

  Examples of basic compounds include substituted or unsubstituted primary, secondary, and tertiary aliphatic amines, aromatic amines, heterocyclic amines, amide derivatives, imide derivatives, and cyano groups. Examples thereof include nitrogen-containing compounds. Of these, aliphatic amines, aromatic amines, and heterocyclic amines are preferable. Preferred substituents that may be present are an amino group, an alkyl group, an alkoxy group, an acyl group, an acyloxy group, an aryl group, an aryloxy group, a nitro group, a cyano group, an ester group, and a lactone group.

The basic compound can be used alone or in combination of two or more, and it is more preferable to use two or more.
The amount of the basic compound used is usually 0.0 based on the solid content of the positive resist composition.
It is 01-10 mass%, Preferably it is 0.01-5 mass%.

  The use ratio of the acid generator and the basic compound in the composition is preferably acid generator / basic compound (molar ratio) = 2.5 to 300. In other words, the molar ratio is preferably 2.5 or more from the viewpoint of sensitivity and resolution, and is preferably 300 or less from the viewpoint of suppressing the reduction in resolution due to the thickening of the resist pattern over time until post-exposure heat treatment. The acid generator / basic compound (molar ratio) is more preferably 5.0 to 200, still more preferably 7.0 to 150.

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

When the positive resist composition of the present invention contains the surfactant (E), a resist having good sensitivity and resolution and less adhesion and development defects when using an exposure light source of 250 nm or less, particularly 220 nm or less. A pattern can be given.
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.

  (E) The usage-amount of surfactant is 0.0001-2 mass% with respect to positive resist composition whole quantity (except a solvent), More preferably, it is 0.001-1 mass%.

(F) Organic solvent Solvents that can be used when preparing the positive resist composition by dissolving the above components include, for example, alkylene glycol monoalkyl ether carboxylate, alkylene glycol monoalkyl ether, and lactate alkyl ester. Alkoxypropionate alkyl, cyclic lactone having 4 to 10 carbon atoms, monoketone compound having 4 to 10 carbon atoms which may contain a ring, alkylene carbonate, alkyl alkoxyacetate, alkyl pyruvate and the like.

Examples of the alkylene glycol monoalkyl ether carboxylate include propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, propylene glycol monomethyl ether propionate, propylene glycol monoethyl Preferred examples include ether propionate, ethylene glycol monomethyl ether acetate, and ethylene glycol monoethyl ether acetate.
Preferred examples of the alkylene glycol monoalkyl ether include propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, ethylene glycol monomethyl ether, and ethylene glycol monoethyl ether.

Preferred examples of the alkyl lactate include methyl lactate, ethyl lactate, propyl lactate and butyl lactate.
Preferable examples of the alkyl alkoxypropionate include ethyl 3-ethoxypropionate, methyl 3-methoxypropionate, methyl 3-ethoxypropionate, and ethyl 3-methoxypropionate.

  Examples of the cyclic lactone having 4 to 10 carbon atoms include β-propiolactone, β-butyrolactone, γ-butyrolactone, α-methyl-γ-butyrolactone, β-methyl-γ-butyrolactone, γ-valerolactone, γ- Caprolactone, γ-octanoic lactone, and α-hydroxy-γ-butyrolactone are preferred.

  Examples of the monoketone compound having 4 to 10 carbon atoms which may contain a ring include 2-butanone, 3-methylbutanone, pinacolone, 2-pentanone, 3-pentanone, 3-methyl-2-pentanone, 4- Methyl-2-pentanone, 2-methyl-3-pentanone, 4,4-dimethyl-2-pentanone, 2,4-dimethyl-3-pentanone, 2,2,4,4-tetramethyl-3-pentanone, 2 -Hexanone, 3-hexanone, 5-methyl-3-hexanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-methyl-3-heptanone, 5-methyl-3-heptanone, 2,6-dimethyl-4 -Heptanone, 2-octanone, 3-octanone, 2-nonanone, 3-nonanone, 5-nonanone, 2-decanone, 3-decanone, 4-decanone, 5- Xen-2-one, 3-penten-2-one, cyclopentanone, 2-methylcyclopentanone, 3-methylcyclopentanone, 2,2-dimethylcyclopentanone, 2,4,4-trimethylcyclopenta Non, cyclohexanone, 3-methylcyclohexanone, 4-methylcyclohexanone, 4-ethylcyclohexanone, 2,2-dimethylcyclohexanone, 2,6-dimethylcyclohexanone, 2,2,6-trimethylcyclohexanone, cycloheptanone, 2-methylcyclo Preferred are heptanone and 3-methylcycloheptanone.

Preferred examples of the alkylene carbonate include propylene carbonate, vinylene carbonate, ethylene carbonate, and butylene carbonate.
Examples of the alkyl alkoxyacetate include 2-methoxyethyl acetate, 2-ethoxyethyl acetate, 2- (2-ethoxyethoxy) ethyl acetate, 3-methoxy-3-methylbutyl acetate, and 1-methoxy-acetate. 2-propyl is preferred.
Preferred examples of the alkyl pyruvate include methyl pyruvate, ethyl pyruvate, and propyl pyruvate.
As a solvent which can be preferably used, a solvent having a boiling point of 130 ° C. or higher under normal temperature and normal pressure can be mentioned. Specifically, cyclopentanone, γ-butyrolactone, cyclohexanone, ethyl lactate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, ethyl 3-ethoxypropionate, ethyl pyruvate, 2-ethoxyethyl acetate, acetic acid -2- (2-ethoxyethoxy) ethyl and propylene carbonate are mentioned.
In the present invention, the above solvents may be used alone or in combination of two or more.

In this invention, you may use the mixed solvent which mixed the solvent which contains a hydroxyl group in a structure, and the solvent which does not contain a hydroxyl group as an organic solvent.
Examples of the solvent containing 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. Particularly preferred are propylene glycol monomethyl ether and ethyl lactate.
Examples of the solvent not containing a hydroxyl group include propylene glycol monomethyl ether acetate, ethyl ethoxypropionate, 2-heptanone, γ-butyrolactone, cyclohexanone, butyl acetate, N-methylpyrrolidone, N, N-dimethylacetamide, dimethyl sulfoxide and the like. Among these, propylene glycol monomethyl ether acetate, ethyl ethoxypropionate, 2-heptanone, γ-butyrolactone, cyclohexanone, and butyl acetate are particularly preferable, and propylene glycol monomethyl ether acetate, ethyl ethoxypropionate. 2-heptanone is most preferred.
The mixing ratio (weight) of the solvent containing a hydroxyl group and the solvent not containing a hydroxyl group is 1/99 to 99/1, preferably 10/90 to 90/10, more preferably 20/80 to 60/40. . A mixed solvent containing 50% by weight or more of a solvent not containing a hydroxyl group is particularly preferred from the viewpoint of coating uniformity.

(G) Alkali-soluble resin The positive resist composition of the present invention may further contain an acid-decomposable group, (G) a resin that is insoluble in water and soluble in an alkaline developer, This improves the sensitivity.
In the present invention, a novolak resin having a molecular weight of about 1000 to 20000 and a polyhydroxystyrene derivative having a molecular weight of about 3000 to 50000 can be used as such a resin, since these have a large absorption with respect to light of 250 nm or less. It is preferable to use a partly hydrogenated amount or 30% by weight or less of the total resin amount.
A resin containing a carboxyl group as an alkali-soluble group can also be used. The resin containing a carboxyl group preferably has a monocyclic or polycyclic alicyclic hydrocarbon group for improving dry etching resistance. Specifically, a methacrylic acid ester and (meth) acrylic acid copolymer having an alicyclic hydrocarbon structure that does not exhibit acid decomposability, or a (meth) acrylic acid ester having an alicyclic hydrocarbon group having a carboxyl group at the terminal And the like.

(H) Carboxylic acid onium salt Examples of the (H) carboxylic acid onium salt in the present invention include a carboxylic acid sulfonium salt, a carboxylic acid iodonium salt, and a carboxylic acid ammonium salt. In particular, the (H) carboxylic acid onium salt is preferably an iodonium salt or a sulfonium salt. Furthermore, it is preferable that the carboxylate residue of the (H) carboxylic acid onium salt of the present invention does not contain an aromatic group or a carbon-carbon double bond. As a particularly preferable anion moiety, a linear, branched, monocyclic or polycyclic alkylcarboxylic acid anion having 1 to 30 carbon atoms is preferable. More preferably, an anion of a carboxylic acid in which some or all of these alkyl groups are fluorine-substituted is preferable. The alkyl chain may contain an oxygen atom. This ensures transparency with respect to light of 220 nm or less, improves sensitivity and resolution, and improves density dependency and exposure margin.

  Fluoro-substituted carboxylic acid anions include fluoroacetic acid, difluoroacetic acid, trifluoroacetic acid, pentafluoropropionic acid, heptafluorobutyric acid, nonafluoropentanoic acid, perfluorododecanoic acid, perfluorotridecanoic acid, perfluorocyclohexanecarboxylic acid, 2 , 2-bistrifluoromethylpropionic acid anion and the like.

These (H) carboxylic acid onium salts can be synthesized by reacting sulfonium hydroxide, iodonium hydroxide, ammonium hydroxide and carboxylic acid with silver oxide in a suitable solvent.

  The content of the (H) carboxylic acid onium salt in the positive resist composition is suitably 0.1 to 20% by weight, preferably 0.5 to 10% by weight, based on the total solid content of the positive resist composition. %, More preferably 1 to 7% by weight.

Other Additives In the positive resist composition of the present invention, a dye, a plasticizer, a photosensitizer, and a compound that promotes solubility in a developer (for example, a phenol compound having a molecular weight of 1000 or less, if necessary) An alicyclic or aliphatic compound having a carboxyl group) or the like can be contained.

Such phenol compounds having a molecular weight of 1000 or less can be obtained by referring to, for example, the methods described in JP-A-4-1222938, JP-A-2-28531, US Pat. No. 4,916,210, European Patent 219294, etc. It can be easily synthesized by those skilled in the art.
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.

(Usage / dry exposure)
The positive resist composition of the present invention is applied on a substrate to form a thin film. The thickness of this coating film is preferably 0.05 to 4.0 μm.

  In the present invention, a commercially available inorganic or organic antireflection film can be used if necessary. Further, an antireflection film can be applied to the upper layer of the resist.

  As the antireflection film used as the lower layer of the resist, either an inorganic film type such as titanium, titanium dioxide, titanium nitride, chromium oxide, carbon, amorphous silicon, or an organic film type made of a light absorber and a polymer material may be used. it can. The former requires equipment such as a vacuum deposition apparatus, a CVD apparatus, and a sputtering apparatus for film formation. Examples of the organic antireflection film include a condensate of a diphenylamine derivative and a formaldehyde-modified melamine resin described in JP-B-7-69611, an alkali-soluble resin, a light absorber, and maleic anhydride copolymer described in US Pat. No. 5,294,680. A reaction product of a coalescence and a diamine type light absorbing agent, a resin binder described in JP-A-6-186863 and a methylolmelamine thermal crosslinking agent, a carboxylic acid group, an epoxy group and a light-absorbing group described in JP-A-6-118656. An acrylic resin-type antireflection film in the same molecule, a composition comprising methylol melamine and a benzophenone-based light absorber described in JP-A-8-87115, and a low-molecular light absorber added to a polyvinyl alcohol resin described in JP-A-8-179509 And the like.

  In addition, as the organic antireflection film, commercially available organic antireflection films such as DUV30 series, DUV-40 series manufactured by Brewer Science, AR-2, AR-3, AR-5 manufactured by Shipley, etc. may be used. it can.

  In the manufacture of precision integrated circuit elements, the pattern formation process on the resist film is performed on a substrate (eg, a silicon / silicon dioxide coated substrate, a glass substrate, an ITO substrate, a quartz / chromium oxide coated substrate, etc.). By applying a type resist composition, and then irradiating with KrF excimer laser light, ArF excimer laser light, F2 excimer laser light, X-rays, electron beam, ion beam or EUV, heating, developing, rinsing and drying. A good resist pattern can be formed.

(How to use / Immersion exposure)
The positive resist composition of the present invention can be used for immersion exposure by dissolving the above components in a predetermined organic solvent and applying the solution on a predetermined support.
That is, a positive resist composition is formed on a substrate (eg, silicon / silicon dioxide coating) used for the manufacture of precision integrated circuit elements by an appropriate coating method such as a spinner or a coater, with an arbitrary thickness (usually 50 to 500 nm). After application, the resist film is washed with immersion water as necessary. The washing time is usually 5 seconds to 5 minutes.
The solid content concentration when the resist component is dissolved in a solvent is preferably 2.0 to 6.0 mass%, more preferably 2.0 to 5.5 mass%, and still more preferably 2.0 to 6.0 mass%. It is 4.0 mass%, Most preferably, it is 2.0-3.5 mass%.
Subsequently, the resist applied by spin or bake is dried to form a resist film, and then exposed through a mask or the like for pattern formation and exposed (immersion exposure) through immersion water. For example, the exposure is performed in a state where the space between the resist film and the optical lens is filled with the immersion liquid. The exposure amount can be set as appropriate, but is usually 1 to 100 mJ / cm ² . After exposure, the resist film is washed with immersion water as necessary. The time is usually 5 seconds to 5 minutes. Subsequently, spin or / and baking is preferably performed, and development and rinsing are performed to obtain a good pattern. The baking temperature is usually 30 to 300 ° C. From the above-mentioned PED point, it is better that the time from the exposure to the baking process is short.
Here, the exposure light is preferably far ultraviolet rays having a wavelength of 250 nm or less, more preferably 220 nm or less. Specific examples include KrF excimer laser (248 nm), ArF excimer laser (193 nm), F ₂ excimer laser (157 nm), X-rays, and the like.
Incidentally, it is considered that the change in performance observed when the resist is applied to immersion exposure is derived from the contact of the resist surface with the immersion liquid.

The immersion liquid used for the immersion exposure will be described below.
The immersion liquid is preferably a liquid that is transparent to the exposure wavelength and has a refractive index temperature coefficient as small as possible so as to minimize distortion of the optical image projected onto the resist. In the case of an ArF excimer laser (wavelength: 193 nm), it is preferable to use water from the viewpoints of availability and ease of handling in addition to the above-described viewpoints.
When water is used as the immersion liquid, the surface tension of the water is decreased and the surface activity is increased, so that the resist layer on the wafer is not dissolved and the influence on the optical coating on the lower surface of the lens element can be ignored. An additive (liquid) may be added in a small proportion. The additive is preferably an aliphatic alcohol having a refractive index substantially equal to that of water, and specifically includes methyl alcohol, ethyl alcohol, isopropyl alcohol and the like. By adding an alcohol having a refractive index substantially equal to that of water, even if the alcohol component in water evaporates and the content concentration changes, an advantage that the change in the refractive index of the entire liquid can be extremely small can be obtained. On the other hand, when an opaque substance or impurities whose refractive index is significantly different from that of water are mixed with respect to 193 nm light, the optical image projected on the resist is distorted. Therefore, distilled water is preferable as the water to be used. Further, pure water filtered through an ion exchange filter or the like may be used.

In order to prevent the resist film from coming into direct contact with the immersion liquid between the resist film formed by the immersion exposure resist of the present invention and the immersion liquid, it is also called an immersion liquid hardly soluble film (hereinafter also referred to as “top coat”). ) May be provided. The necessary functions for the top coat are suitability for application to the upper layer of the resist, radiation, especially transparency to 193 nm, and poor immersion liquid solubility. It is preferable that the top coat is not mixed with the resist and can be uniformly applied to the resist upper layer.
From the viewpoint of 193 nm transparency, the topcoat is preferably a polymer that does not contain an aromatic, and specifically, a hydrocarbon polymer, an acrylate polymer, a polymethacrylic acid, a polyacrylic acid, a polyvinyl ether, a silicon-containing polymer, And fluorine-containing polymers.
When peeling the top coat, a developer may be used, or a separate release agent may be used. As the release agent, a solvent having a small penetration into the resist is preferable. It is preferable that the peeling process can be performed with an alkali developer in that the peeling process can be performed simultaneously with the resist development process. From the viewpoint of peeling with an alkaline developer, the topcoat is preferably acidic, but may be neutral or alkaline from the viewpoint of non-intermixability with the resist.
The resolution is improved when there is no difference in refractive index between the topcoat and the immersion liquid. When the exposure light source is an ArF excimer laser (wavelength: 193 nm), it is preferable to use water as the immersion liquid, so that the top coat for ArF immersion exposure is close to the refractive index of water (1.44). Is preferred. A thin film is more preferable from the viewpoint of transparency and refractive index.

In the development process, a developer is used as follows. As a developing solution for a positive resist composition, inorganic hydroxides such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia, and primary amines such as ethylamine and n-propylamine are used. 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, etc. Alkaline aqueous solutions of 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 aqueous solution.
As the rinsing liquid, pure water can be used, and an appropriate amount of a surfactant can be added.
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.

  Further, after the development process or the rinsing process, a process of removing the developer or the rinsing liquid adhering to the pattern with a supercritical fluid can be performed.

  EXAMPLES Hereinafter, although an Example demonstrates this invention still in detail, the content of this invention is not limited by this.

Synthesis Example 1 (Synthesis of Resin (1))
2-Adamantyl-2-propyl methacrylate, hydroxyadaman methacrylate, norbornane lactone acrylate, 1-methacryloyloxy-7-hydroxynaphthalene in a ratio (molar ratio) of 33/22/32/13, propylene glycol monomethyl ether acetate / propylene glycol It melt | dissolved in the mixed solvent of monomethyl ether = 70/30, and 450 g of solutions with a solid content concentration of 22 mass% were prepared. To this solution, 3 mol% of a polymerization initiator V-601 manufactured by Wako Pure Chemical Industries, Ltd. was added, and this was heated to 80 ° C. over 6 hours in a nitrogen atmosphere, propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether = 70 / It was dripped at 50 g of 30 mixed solvents. After completion of dropping, the reaction solution was stirred for 2 hours to obtain a reaction solution (1). After completion of the reaction, the reaction solution (1) is cooled to room temperature, crystallized in a mixed solvent of 4.5 times the amount of hexane / ethyl acetate = 90/10, and the precipitated white powder is collected by filtration to obtain the desired product. Resin (1) was recovered.
^The polymer composition ratio determined from ¹³ CNMR and acid value titration was 30/20/35/15. Moreover, the standard polystyrene conversion weight average molecular weight calculated | required by GPC measurement was 12500, and dispersion degree was 1.9.

  Resins (2) to (16) were synthesized using the synthesis method used in the above synthesis example. The structure and composition, weight average molecular weight, and molecular weight dispersion of the synthesized resins (2) to (16) are shown below. The composition indicates the order from the left in each structural formula.

Synthesis Example 2 (Synthesis of Resin (17) of Comparative Example)
2-adamantyl-2-propyl methacrylate, hydroxyadaman methacrylate, and norbornane lactone acrylate were dissolved in a mixed solvent of propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether = 70/30 at a ratio (molar ratio) of 41/26/33. 450 g of a solution having a solid content concentration of 22% was prepared. To this solution, 3 mol% of a polymerization initiator V-601 manufactured by Wako Pure Chemical Industries, Ltd. was added, and this was heated to 80 ° C. over 6 hours in a nitrogen atmosphere, propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether = 70 / It was dripped at 50 g of 30 mixed solvents. After completion of dropping, the reaction solution was stirred for 2 hours to obtain a reaction solution (17). After completion of the reaction, the reaction liquid (17) is cooled to room temperature, crystallized in a mixed solvent of 4.5 times the amount of hexane / ethyl acetate = 90/10, and the precipitated white powder is collected by filtration to obtain the desired product. A resin (17) having the following structure was recovered.
^The polymer composition ratio determined from ¹³ CNMR and acid value titration was 40/25/35. Moreover, the standard polystyrene conversion weight average molecular weight calculated | required by GPC measurement was 11800, and dispersion degree was 2.0.

Examples 1 to 16 and Comparative Example 1
<Registration adjustment>
The components shown in Tables 2 to 3 below were dissolved in a solvent to prepare a solution having a solid concentration of 5% by mass, and this was filtered through a 0.1 μm polyethylene filter to prepare a positive resist solution. The prepared positive resist composition was evaluated by the following method, and the results are shown in Tables 2 to 3 below. In addition, about each component in a table | surface, ratio when using two or more is a mass ratio.

<Evaluation>
An organic antireflection film ARC29A (Nissan Chemical Co., Ltd.) was applied onto a silicon wafer and baked at 205 ° C. for 60 seconds to form a 78 nm antireflection film.
A positive resist composition (solid content concentration 5%) prepared thereon was applied, and baked at 115 ° C. for 60 seconds to form a resist film having a thickness of 150 nm. The obtained wafer was subjected to immersion exposure using an ArF excimer laser scanner (Nikon Corp.). As the immersion liquid, ultrapure water having impurities of 5 ppb or less was used. Thereafter, heating was performed at 120 ° C. for 60 seconds, followed by development with an aqueous tetramethylammonium hydroxide solution (2.38 mass%) for 60 seconds, rinsing with pure water, and spin drying to obtain a resist pattern.
For comparison, dry exposure was performed, and a resist pattern was obtained under the same conditions as described above.

-Pattern profile The profile of the obtained pattern was observed and evaluated with a scanning electron microscope (S-9260, manufactured by Hitachi, Ltd.).
Development defect The number of defects present on the wafer was counted using a defect inspection apparatus manufactured by KLA.
Pattern collapse The dimension (nm) at which pattern collapse starts to be observed when the mask line width of a 75 nm line and space pattern (1: 1) is exposed with an exposure amount that can be transferred as a resist pattern.

  Abbreviations in Tables 2 to 3 are as follows.

N-1: Dipropylaniline N-2: Triethanolamine N-3: Trioctylamine N-4: Tris-2- (2-methoxy (ethoxy)) ethylamine N-5: 2,6-diisopropylaniline N- 6: Triphenylimidazole

SL-2: cyclohexanone SL-4; propylene glycol monomethyl ether acetate SL-5: ethyl lactate SL-6: propylene glycol monomethyl ether

  From Tables 2 to 3, the positive resist composition of the present invention is excellent for pattern profiles, development defects, and resist pattern collapse, and good results can be obtained even when applied to immersion exposure. Is clear.

Claims (6)

(A) a resin having a repeating unit having an alicyclic hydrocarbon structure and a repeating unit having a naphthalene structure, which increases the solubility in an alkali developer by the action of an acid, and (B) an acid by irradiation with actinic rays or radiation. A positive resist composition comprising a generated compound.   2. The positive resist composition according to claim 1, wherein the naphthalene structure is a naphthol structure, a naphthalenecarboxylic acid structure, or a structure that is decomposed by the action of an acid to produce a naphthol structure or a naphthalenecarboxylic acid structure.   The resin of component (A) has (i) a repeating unit having a lactone group and (ii) a repeating unit having a group having an alicyclic hydrocarbon structure that is eliminated by the action of an acid. The positive resist composition according to claim 1 or 2.   The positive resist composition according to claim 1, wherein the resin (A) has a fluorine atom.   The positive resist composition according to claim 1, wherein the positive resist composition is used for immersion exposure.   A pattern forming method comprising the steps of: forming a resist film from the positive resist composition according to claim 1; and subjecting the resist film to immersion exposure and development.