JP2007086615A - Positive photosensitive composition, compound for use in the positive photosensitive composition, resin for use in the positive photosensitive composition and pattern forming method using the positive photosensitive composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a positive photosensitive composition which improves line edge roughness and pattern collapse even in formation of a fine pattern of ≤100 nm, a compound for use in the positive photosensitive composition, a resin for use in the positive photosensitive composition and a pattern forming method using the positive photosensitive composition. <P>SOLUTION: The positive photosensitive composition contains (A) a compound capable of generating an acid upon irradiation with an actinic ray or radiation and (B) a resin which is decomposed by the action of an acid to increase solubility in an alkali developer, wherein the resin (B) has a repeating unit having a cyclic hydrocarbon structure and a specific partial structure in the same repeating unit. There are also provided the compound for use in the positive photosensitive composition, the resin for use in the positive photosensitive composition and the pattern forming method using the positive photosensitive composition. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  INDUSTRIAL APPLICABILITY The present invention is used for a positive photosensitive composition used in a semiconductor manufacturing process such as an IC, a circuit board such as a liquid crystal or a thermal head, and other photofabrication processes, and the positive photosensitive composition. The present invention relates to a compound, a resin used in the positive photosensitive composition, and a pattern forming method using the positive photosensitive composition. More specifically, a positive photosensitive composition suitable for use as an exposure light source such as far ultraviolet rays of 250 nm or less, preferably 220 nm or less, and an irradiation source by an electron beam, etc., a compound used in the positive photosensitive composition, The present invention relates to a resin used for the positive photosensitive composition and a pattern forming method using the positive photosensitive composition.

  The chemically amplified photosensitive composition generates an acid in an exposed area by irradiation with actinic light or radiation such as far ultraviolet light, and a reaction using this acid as a catalyst to react an active light or radiation irradiated part with a non-irradiated part. It is a pattern forming material that changes the solubility in a developer and forms a pattern on a substrate.

  When a KrF excimer laser is used as an exposure light source, a resin having a basic skeleton of poly (hydroxystyrene) having a small absorption mainly in the 248 nm region is used as a main component. A pattern is formed, which is a better system than the conventional naphthoquinone diazide / novolak resin system.

On the other hand, when a further short wavelength light source, for example, an ArF excimer laser (193 nm) is used as an exposure light source, the compound having an aromatic group exhibits a large absorption in the 193 nm region. It wasn't.
For this reason, an ArF excimer laser resist containing a resin having an alicyclic hydrocarbon structure has been developed. JP-A-9-73173 (Patent Document 1) describes a resist composition containing an acid-decomposable resin having an adamantane structure. However, with the miniaturization of patterns, it is necessary to reduce the resist film thickness, and resist dry etching resistance is required. US Patent Application Publication No. 2005 / 0074690A (Patent Document 2) describes a resin having a repeating unit having a diamantane structure. However, the resistance to dry etching correlates with the carbon density of the resin and can be improved by increasing the carbon density. However, as the carbon density increases, it becomes hydrophobic and the development defect performance and pattern forming ability deteriorate. In fact, it is extremely difficult to achieve both of these overall performances. Furthermore, when forming a fine pattern such as a line width of 100 nm or less, even if the resolution performance is excellent, the formed line pattern collapses, resulting in a pattern collapse problem that becomes a defect during device manufacturing, Therefore, improvement of the line edge roughness performance of the line pattern has been demanded.
Here, the line edge roughness means that the resist line pattern and the edge of the substrate interface exhibit irregular shapes in a direction perpendicular to the line direction due to the characteristics of the resist. When this pattern is observed from directly above, the edges appear to be uneven (± several nm to several tens of nm). Since the unevenness is transferred to the substrate by an etching process, if the unevenness is large, an electrical characteristic defect is caused and the yield is lowered.

JP-A-9-73173 US Patent Application Publication No. 2005 / 0074690A

  Accordingly, an object of the present invention is to provide a positive photosensitive composition having improved line edge roughness and pattern collapse even in the formation of a fine pattern of 100 nm or less, a compound used in the positive photosensitive composition, the positive type The object is to provide a resin used in a photosensitive composition and a pattern forming method using the positive photosensitive composition.

  The present invention is as follows.

(1) (A) a compound that generates an acid upon irradiation with actinic rays or radiation,
(B) a positive photosensitive composition containing a resin that decomposes by the action of an acid and increases the solubility in an alkaline developer,
The positive photosensitive composition, wherein the resin of component (B) has a repeating unit having a cyclic hydrocarbon structure and a partial structure represented by the following general formula (I) in the same repeating unit.

  (2) The positive photosensitive resin as described in (1), wherein the resin of component (B) has a repeating unit having a group represented by the following general formula (I-1) or (I-2) Sex composition.

In general formulas (I-1) and (I-2),
Xb represents a linking group having a monocyclic or polycyclic hydrocarbon structure.
Ra ₁ represents an organic group.
Xb and Ra ₁ may combine to form a ring structure.

  (3) The positive photosensitive film as described in (1), wherein the resin as the component (B) has a repeating unit represented by any one of the following general formulas (I-1a) to (I-4a): Sex composition.

In the general formulas (I-1a) to (I-4a),
Rxa represents a hydrogen atom, an alkyl group or a cyano group.
Xc represents a group represented by the general formula (I-1) or (I-2).
Ra ₁ represents an organic group.
Ra _{2 to} Ra ₄ each independently represents a hydrogen atom or an organic group.
n represents 0 or 1.

  (4) The positive photosensitive resin as described in any one of (1) to (3), wherein the resin as the component (B) further has an acid-decomposable repeating unit having an alicyclic hydrocarbon structure. Composition.

  (5) The positive photosensitive composition as described in any one of (1) to (4), wherein the resin as the component (B) further has a repeating unit having a lactone structure.

  (6) A polymerizable compound having a group represented by the following general formula (I-1) or (I-2).

In general formulas (I-1) and (I-2),
Xb represents a linking group having a monocyclic or polycyclic hydrocarbon structure.
Ra ₁ represents an organic group.
Xb and Ra ₁ may combine to form a ring structure.

  (7) A polymerizable compound represented by any one of the following general formulas (I-1b) to (I-4b).

In the general formulas (I-1b) to (I-4b),
Rxa represents a hydrogen atom, an alkyl group or a cyano group.
Xc represents a group represented by the general formula (I-1) or (I-2).
Ra ₁ represents an organic group.
Ra _{2 to} Ra ₄ each independently represents a hydrogen atom or an organic group.
n represents 0 or 1.

  (8) A resin having a repeating unit having a group represented by the following general formula (I-1) or (I-2).

In general formulas (I-1) and (I-2),
Xb represents a linking group having a monocyclic or polycyclic hydrocarbon structure.
Ra ₁ represents an organic group.
Xb and Ra ₁ may combine to form a ring structure.

  (9) A resin having a repeating unit represented by any one of the following general formulas (I-1a) to (I-4a).

In the general formulas (I-1a) to (I-4a),
Rxa represents a hydrogen atom, an alkyl group or a cyano group.
Xc represents a group represented by the general formula (I-1) or (I-2).
Ra ₁ represents an organic group.
Ra _{2 to} Ra ₄ each independently represents a hydrogen atom or an organic group.
n represents 0 or 1.

  (10) A pattern formation comprising a step of forming a photosensitive film from the positive photosensitive composition according to any one of (1) to (5), and exposing and developing the photosensitive film. Method.

  According to the present invention, a positive photosensitive composition having improved line edge roughness and pattern collapse even in the formation of a fine pattern of 100 nm or less, a compound used for the positive photosensitive composition, and the positive photosensitive composition And a pattern forming method using the positive photosensitive composition.

Hereinafter, 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 does not have a substituent and what has 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).

[1] (A) Compound that generates acid upon irradiation with actinic ray or radiation The positive photosensitive composition of the present invention is a compound that generates acid upon irradiation with actinic ray or radiation (hereinafter referred to as “photoacid generator”). (Also called).
Examples of such a photoacid generator include a photoinitiator for photocationic polymerization, a photoinitiator for photoradical polymerization, a photodecolorant for dyes, a photochromic agent, or an actinic ray used in a microresist or the like. Known compounds that generate an acid upon irradiation with radiation 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.

  Among the compounds that generate an acid upon irradiation with actinic rays or radiation, compounds represented by the following general formulas (ZI), (ZII), and (ZIII) can be exemplified.

In general formula (ZI):
R ₂₀₁ , R ₂₀₂ and R ₂₀₃ each independently represents an organic group.
X ⁻ represents a non-nucleophilic anion, preferably sulfonate anion, carboxylate anion, bis (alkylsulfonyl) amide anion, tris (alkylsulfonyl) methide anion, BF ₄ ⁻ , PF ₆ ⁻ , SbF ₆ ^{− and the} like. An organic anion having a carbon atom is preferable.

  Preferable organic anions include organic anions represented by the following formula.

Where
Rc ₁ represents an organic group.
Examples of the organic group in Rc ₁ include those having 1 to 30 carbon atoms, and preferably an alkyl group, an aryl group, or a plurality thereof, which may be substituted, is a single bond, —O—, —CO ₂ —, — Examples include groups linked by a linking group such as S-, -SO _3- , -SO ₂ N (Rd ₁ )-. Rd ₁ represents a hydrogen atom or an alkyl group.
Rc ₃ , Rc ₄ and Rc ₅ represent an organic group. Preferred examples of the organic group for Rc ₃ , Rc ₄ , and Rc ₅ include the same organic groups as those for Rb 1, and a perfluoroalkyl group having 1 to 4 carbon atoms is most preferred.
Rc ₃ and Rc ₄ may combine to form a ring. Examples of the group formed by combining Rc ₃ and Rc ₄ include an alkylene group and an arylene group. Preferably, it is a C2-C4 perfluoroalkylene group.
The organic group of Rc ₁ and Rc _{3 to} Rc ₅ is particularly preferably an alkyl group substituted at the _1- position with a fluorine atom or a fluoroalkyl group, or a phenyl group substituted with a fluorine atom or a fluoroalkyl group. By having a fluorine atom or a fluoroalkyl group, the acidity of the acid generated by light irradiation is increased and the sensitivity is improved. Further, when Rc ₃ and Rc ₄ are combined to form a ring, the acidity of the acid generated by light irradiation is increased, and the sensitivity is improved.

In formula (ZI), the carbon number of the organic group as R _201, R ₂₀₂ and R ₂₀₃ is generally from 1 to 30, preferably 1 to 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 (ZI-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 preferred (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 an aryl group such as a phenyl group or a naphthyl group, or a heteroaryl group such as an indole residue or a pyrrole residue, and more preferably a phenyl group or an indole residue. 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 (for example, 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, or a phenylthio group may be substituted. Preferred substituents are straight chain, branched alkyl groups having 1 to 12 carbon atoms, cycloalkyl groups having 3 to 12 carbon atoms, and straight chain, branched or cyclic alkoxy groups having 1 to 12 carbon atoms, and particularly preferably. They are a C1-C4 alkyl group and a C1-C4 alkoxy group. 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.

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 containing 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, particularly preferably Is a linear, branched 2-oxoalkyl group.

The alkyl group as R ₂₀₁ to R ₂₀₃ may be linear, it may be either branched, preferably a straight-chain or branched alkyl group (e.g., methyl group having 1 to 10 carbon atoms, an ethyl group, a propyl Group, butyl group, pentyl group). The alkyl group as R ₂₀₁ to R ₂₀₃ is a straight-chain, branched 2-oxoalkyl group is preferably an alkoxycarbonyl methyl group.
The cycloalkyl group as R ₂₀₁ to R ₂₀₃ is preferably, and a cycloalkyl group having 3 to 10 carbon atoms (e.g., cyclopentyl, cyclohexyl, norbornyl). The cycloalkyl group as R ₂₀₁ to R ₂₀₃ is preferably a cyclic 2-oxoalkyl group.
As R ₂₀₁ to R _203, a linear, branched or cyclic 2-oxoalkyl group may preferably be a group having a 2-position> C = O in the above-described alkyl or cycloalkyl group.
The alkoxy group in the alkoxycarbonylmethyl group as R ₂₀₁ to R _203, preferably may be mentioned alkoxy groups having 1 to 5 carbon atoms (a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a 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.

In general formula (ZI-3),
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 each independently represents 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 , R _6c and R _7c , 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 and a sulfur atom. , An ester bond and an amide bond may be included. Examples of the group formed by combining any two or more of R _{1c to} R _5c , R _6c and R _7c , and R _x and R _y include a butylene group and a pentylene group.

The alkyl group as R _{1c to} R _7c may be either linear or branched, for example, a linear or branched alkyl group having 1 to 20 carbon atoms, preferably 1 to 12 carbon atoms (for example, Methyl group, ethyl group, linear or branched propyl group, linear or branched butyl group, linear or branched pentyl group).
The cycloalkyl group as R _{1c to} R _7c is preferably a cycloalkyl group having 3 to 8 carbon atoms (for example, a cyclopentyl group or 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, branched alkyl group, 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 are the same} as the alkyl group and cycloalkyl group as R _{1c to} R _7c , and are a 2-oxoalkyl group and an alkoxycarbonyl group. Is preferred.
Examples of the 2-oxoalkyl 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 .

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 optionally substituted aryl group, which may have a substituent alkyl or optionally substituted 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 may be linear, it may be either branched, preferably a straight-chain or branched alkyl group (e.g., methyl group having 1 to 10 carbon atoms, an ethyl group, a propyl Group, butyl group, pentyl group).
The cycloalkyl group as R ₂₀₄ to R ₂₀₇ is preferably, and a cycloalkyl group having 3 to 10 carbon atoms (e.g., cyclopentyl, cyclohexyl, norbornyl).
The R ₂₀₄ to R ₂₀₇ are substituents which may have, for example, an alkyl group (for example, 1 to 15 carbon atoms), an aryl group (e.g. having 6 to 15 carbon atoms), an alkoxy group (for example, 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).

  Among the compounds that generate an acid upon irradiation with actinic rays or radiation, compounds represented by the following general formulas (ZIV), (ZV), and (ZVI) can be further exemplified.

In general formulas (ZIV) to (ZVI),
Ar ₃ and Ar ₄ each independently represent a substituted or unsubstituted aryl group.
R ₂₀₆ represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, or a substituted or unsubstituted aryl group.
R _207a and R ₂₀₈ represent a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted aryl group, or an electron-withdrawing group. R _207a is preferably a substituted or unsubstituted aryl group. R ₂₀₈ is preferably an electron-withdrawing group, more preferably a cyano group or a fluoroalkyl group.
A represents a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkenylene group, or a substituted or unsubstituted arylene group.

  Of the compounds that generate an acid upon irradiation with actinic rays or radiation, compounds represented by general formulas (ZI) to (ZIII) are more preferable.

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

A photo-acid generator can be used individually by 1 type or in combination of 2 or more types. When two or more types are used in combination, it is preferable to combine two types of compounds that generate two types of organic acids that differ in the total number of atoms excluding hydrogen atoms by two or more.
The content of the photoacid generator in the composition is preferably 0.1 to 20% by mass, more preferably 0.5 to 10% by mass, and still more preferably, based on the total solid content of the positive photosensitive composition. 1 to 7% by mass.

[2] (B) A resin that decomposes by the action of an acid and increases the solubility in an alkaline developer, and includes a cyclic hydrocarbon structure and a partial structure represented by the general formula (I) in the same repeating unit; The positive photosensitive composition of the present invention is a resin that decomposes by the action of an acid and increases the solubility in an alkaline developer, and has a cyclic hydrocarbon structure in the same repeating unit. A resin having a repeating unit having a partial structure represented by the following general formula (I) (also referred to as “resin of component (B)”) is contained.

  Preferred examples of the repeating unit having a partial structure represented by the general formula (I) include a repeating unit having a group represented by the following general formula (I-1) or (I-2).

In general formulas (I-1) and (I-2),
Xb represents a linking group having a monocyclic or polycyclic hydrocarbon structure.
Ra ₁ represents an organic group.
Xb and Ra ₁ may combine to form a ring structure.

The monocyclic hydrocarbon linking group in Xb is preferably one having 4 to 10 carbon atoms, more preferably one obtained by removing two hydrogen atoms from cyclopentane or cyclohexane to form a linking group.
The polycyclic hydrocarbon linking group in Xb is preferably one having 7 to 20 carbon atoms, more preferably two hydrogen atoms are removed from the polycyclic hydrocarbon having 7 to 15 carbon atoms to form a linking group. Is. Preferred examples of the polycyclic hydrocarbon include norbornane, adamantane, diamantane, tricyclodecane, and tetracyclododecane.
Examples of the organic group in Ra ₁ include an alkyl group, a cycloalkyl group, an aryl group, and an aralkyl group.
As the alkyl group, a linear or branched alkyl group having 1 to 20 carbon atoms is preferable. Specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a t-butyl group, a hexyl group. Octyl group, dodecyl group and the like.
As the cycloalkyl group, a cycloalkyl group having 3 to 20 carbon atoms is preferable. Specifically, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a norbornyl group, an adamantyl group, a tetracyclododecyl group, A tricyclodecyl group etc. are mentioned.
Examples of the aryl group include a phenyl group, a naphthyl group, a thiophene group, a furan group, a pyrrole group, and an indole group.
Examples of the aralkyl group include groups in which the aryl group is linked with an alkyl group having 1 to 4 carbon atoms.
The organic group of Ra ₁ may be substituted with a halogen atom (preferably a fluorine atom), an alkyl group (preferably 1 to 5 carbon atoms), or the like.
The ring structure formed by combining Xb and Ra ₁ is preferably a 5- or 6-membered ring.

  The repeating unit having a cyclic hydrocarbon structure and a partial structure represented by the general formula (I) in the same repeating unit is more preferably represented by the following general formulas (I-1a) to (I-4a). Repeat units can be raised.

In the general formulas (I-1a) to (I-4a),
Rxa represents a hydrogen atom, an alkyl group or a cyano group.
Xc represents a group represented by the general formula (I-1) or (I-2).
Ra ₁ represents an organic group.
Ra _{2 to} Ra ₄ each independently represents a hydrogen atom or an organic group.
n represents 0 or 1.

The alkyl group of Rxa is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl. Group, pentyl group, isopentyl group, neopentyl group, t-pentyl group and the like. The alkyl group of Rxa may be substituted with a halogen atom (preferably a fluorine atom), a —ORa ₅ group or the like. In the formula, Ra ₅ represents a hydrogen atom, an alkyl group, an acyl group, or a lactone group.
Rxa is preferably a hydrogen atom, a methyl group, a cyano group, a trifluoromethyl group, or a —CH ₂ —ORa ₅ group.
Ra ₁ has the same meaning as Ra ₁ in formula (I-1) ~ (I -2).
Examples of the organic group represented by Ra _{2 to} Ra ₄ include an alkyl group, a carboxyl group, an alkoxycarbonyl group, and a cyano group. Examples of the alkyl group in Ra _{2 to} Ra ₄ include the same as the alkyl group of Rxa and may be substituted with a halogen atom (preferably a fluorine atom). The alkoxy group of the alkoxycarbonyl group in Ra _{2 to} Ra ₄ is preferably an alkoxy group having 1 to 5 carbon atoms, and examples thereof include a methoxy group, an ethoxy group, a propoxy group, and an n-butoxy group.

  Hereinafter, although the specific example of the repeating unit represented by general formula (I-1a)-(I-4a) is given, this invention is not limited to this.

  The repeating unit having a cyclic hydrocarbon structure and a partial structure represented by the general formula (I) in the same repeating unit is, for example, a group represented by the following general formula (I-1) or (I-2). It can be obtained by polymerizing the polymerizable compound.

In general formulas (I-1) and (I-2),
Xb represents a linking group having a monocyclic or polycyclic hydrocarbon structure.
Ra ₁ represents an organic group.
Xb and Ra ₁ may combine to form a ring structure.

  Examples of the polymerizable compound having a group represented by the general formula (I-1) or (I-2) include polymerizable compounds represented by the following general formulas (I-1b) to (I-2b). Can be mentioned.

  The repeating units represented by the general formulas (I-1a) to (I-4a) can be obtained by polymerizing polymerizable compounds represented by the following general formulas (I-1b) to (I-4b). it can.

In the general formulas (I-1b) to (I-4b),
Rxa represents a hydrogen atom, an alkyl group or a cyano group.
Xc represents a group represented by the general formula (I-1) or (I-2).
Ra ₁ represents an organic group.
Ra _{2 to} Ra ₄ each independently represents a hydrogen atom or an organic group.
n represents 0 or 1.

In the general formulas (I-1b) to (I-4b), Rxa, Xc, Ra ₁ , Ra _{2 to} Ra ₄ and n are the same as those in the general formulas (I-1a) to (I-4a). Rxa, Xc, is synonymous with _{Ra 1, Ra 2 ~Ra 4,} n.

  Hereinafter, although the specific example of the polymeric compound represented by general formula (I-1b)-(I-4b) is given, this invention is not limited to this.

The polymerizable compound is a novel compound.
The polymerizable compound may be prepared by, for example, reacting the corresponding carbonyl chloride and the corresponding sulfonamide under basic conditions or using the corresponding carboxylic acid and the corresponding sulfonamide using a condensing agent such as dicyclohexylcarbodiimide or carbonyldiimidazole. It can be obtained by reacting. The compound represented by the general formula (I-2b) can also be obtained by reacting the compound represented by the general formula (I-1b) obtained by the above method with dicyclopentadiene.

  When the positive photosensitive composition of the present invention is irradiated with ArF excimer laser light, the resin of component (B) is a cyclic structure and a partial structure represented by the general formula (I) in the same repeating unit. It is preferable to have a repeating unit having a monocyclic or polycyclic alicyclic hydrocarbon structure.

  As the repeating unit having a monocyclic or polycyclic alicyclic hydrocarbon structure, a repeating unit having a partial structure containing an alicyclic hydrocarbon represented by the following general formula (pI) to general formula (pV) and the following general formula The repeating unit shown by (II-AB) can be mentioned.

In general formulas (pI) to (pV),
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 is an atom necessary for forming a cycloalkyl group together with a carbon atom. Represents a group.
R _{12 to} R ₁₆ each independently represents a linear or branched alkyl group or cycloalkyl group having 1 to 4 carbon atoms. However, at least one of R _{12 to} R ₁₄ , or any of R ₁₅ and R ₁₆ represents a cycloalkyl 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 a cycloalkyl group. However, at least one of R _{17 to} R ₂₁ represents a cycloalkyl group. Further, either R ₁₉ or R ₂₁ represents a linear or branched alkyl group or cycloalkyl 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 a cycloalkyl group. However, at least one of R _{22 to} R ₂₅ represents a cycloalkyl group. R ₂₃ and R ₂₄ may be bonded to each other to form a ring.

In general formula (II-AB),
R ₁₁ ′ and R ₁₂ ′ each independently represents a hydrogen atom, a cyano group, a halogen atom or an alkyl group.
Z ′ represents an atomic group for forming an alicyclic structure containing two bonded carbon atoms (C—C).

  The general formula (II-AB) is more preferably the following general formula (II-AB1) or general formula (II-AB2).

In general formulas (II-AB1) and (II-AB2),
R ₁₃ ′ to R ₁₆ ′ each independently represents a hydrogen atom, a halogen atom, a cyano group, —COOH, —COOR ₅ , a group capable of decomposing by the action of an acid (acid-decomposable group), —C (═O) — XA′—R ₁₇ ′ represents an alkyl group or a cycloalkyl group. At least two of R ₁₃ ′ to R ₁₆ ′ may combine to form a ring.
Here, R ₅ represents an alkyl group, a cycloalkyl group, or a group having a lactone structure.
X represents an oxygen atom, a sulfur atom, -NH -, - NHSO ₂ - or an -NHSO ₂ NH-.
A ′ represents a single bond or a divalent linking group.
R ₁₇ ′ represents —COOH, —COOR ₅ , —CN, a hydroxyl group, an alkoxy group, —CO—NH—R ₆ , —CO—NH—SO ₂ —R ₆ or a group having a lactone structure.
R ₆ represents an alkyl group or a cycloalkyl group.
n represents 0 or 1.

Examples of the linear or branched alkyl group having 1 to 4 carbon atoms of R _{12 to} R _{25 in} the general formulas (pI) to (pV) include a methyl group, an ethyl group, and an n-propyl group. Isopropyl group, n-butyl group, isobutyl group, sec-butyl group and the like.

The cycloalkyl group in R _{11 to} R ₂₅ or the cycloalkyl group formed by Z and the 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 cycloalkyl groups may have a substituent.

  Preferred cycloalkyl groups include adamantyl group, noradamantyl group, decalin residue, tricyclodecanyl group, tetracyclododecanyl group, norbornyl group, cedrol group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, A cyclodecanyl group and a cyclododecanyl group can be mentioned. More preferable examples include an adamantyl group, norbornyl group, cyclohexyl group, cyclopentyl group, tetracyclododecanyl group, and tricyclodecanyl group.

  These alkyl groups and cycloalkyl groups may further have a substituent. Examples of further substituents include an alkyl group (1 to 4 carbon atoms), a halogen atom, a hydroxyl group, and an alkoxy group (1 to 4 carbon atoms). ), A carboxyl group, and an alkoxycarbonyl group (having 2 to 6 carbon atoms). Examples of the substituent that the alkyl group, alkoxy group, alkoxycarbonyl group and the like may further have include a hydroxyl group, a halogen atom, and an alkoxy group.

  The structures represented by the general formulas (pI) to (pV) 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 structure in which a hydrogen atom of a carboxylic acid group, a sulfonic acid group, a phenol group, or a thiol group is substituted with a structure represented by the general formulas (pI) to (PV), preferably a carboxylic acid Group, the hydrogen atom of a sulfonic acid group is the structure substituted by the structure represented by general formula (pI)-(PV).
The structure in which the hydrogen atom of the alkali-soluble group is protected by the structure represented by the general formulas (pI) to (pV) is an acid-decomposable group, which is decomposed by the action of an acid to form an alkali-soluble group. Increase solubility in developer.

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

In 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 one of the general formulas (pI) to (pV).

  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.

Examples of the halogen atom in the general formula (II-AB), R ₁₁ ′, and R ₁₂ ′ include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom.

Examples of the alkyl group for R ₁₁ ′ and R ₁₂ ′ include linear or branched alkyl groups having 1 to 10 carbon atoms.

  The atomic group for forming the alicyclic structure of Z ′ is an atomic group that forms a repeating unit of an alicyclic hydrocarbon which may have a substituent in a resin, and among them, a bridged type alicyclic group. An atomic group for forming a bridged alicyclic structure forming a cyclic hydrocarbon repeating unit is preferred.

Examples of the alicyclic hydrocarbon skeleton to be formed include the same alicyclic hydrocarbon groups as R _{11 to} R _{25 in} the general formulas (pI) to (pV).

The alicyclic hydrocarbon skeleton may have a substituent. Examples of such a substituent include R ₁₃ ′ to R ₁₆ ′ in the general formula (II-AB1) or (II-AB2).

In the resin of component (B) according to the present invention, the group (acid-decomposable group) that is decomposed by the action of an acid includes the alicyclic hydrocarbon represented by the general formula (pI) to the general formula (pV). A repeating unit having a partial structure, a repeating unit represented by the general formula (II-AB), preferably a repeating unit represented by the general formula (II-AB1) or (II-AB2), and a repeating unit of the below-mentioned copolymerization component Can be contained in at least one repeating unit.
That is, in the repeating unit represented by the general formula (II-AB1) or (II-AB2), when R ₁₃ ′ to R ₁₄ ′ are acid-decomposable groups, the general formula (II-AB1) or The repeating unit represented by (II-AB2) is an acid-decomposable repeating unit having an alicyclic hydrocarbon structure.

Various substituents of R ₁₃ ′ to R ₁₆ ′ in the general formula (II-AB1) or the general formula (II-AB2) are atomic groups for forming an alicyclic structure in the general formula (II-AB). It can also be a substituent of the atomic group Z for forming a bridged alicyclic structure.

  Specific examples of the repeating unit represented by the general formula (II-AB1) or (II-AB2) include the following specific examples, but the present invention is not limited to these specific examples.

  The resin of the component (B) of the present invention preferably has a group having a lactone ring. As the group having a lactone ring, any group having a lactone ring can be used, but a group having a 5- to 7-membered ring lactone structure is preferred. A structure in which another ring structure is condensed to form a structure or a spiro structure is preferable. A group having a lactone structure represented by any of the following general formulas (LC1-1) to (LC1-16) is more preferable. Further, a group having a lactone structure may be directly bonded to the main chain. Preferred lactone structures are (LC1-1), (LC1-4), (LC1-5), (LC1-6), (LC1-13), and (LC1-14). Edge roughness and development defects are improved.

The lactone structure moiety may or may not have a substituent (Rb ₂ ). Preferred substituents (Rb ₂ ) 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, an alkoxycarbonyl group having 1 to 8 carbon atoms, and a carboxyl group. , Halogen atom, hydroxyl group, cyano group, acid-decomposable group and the like. n2 represents an integer of 0 to 4. When n2 is 2 or more, a plurality of Rb ₂ may be the same or different, and a plurality of Rb ₂ may be bonded to form a ring.

As the repeating unit having a group having a lactone structure represented by any of the general formulas (LC1-1) to (LC1-13), R _{13 in the} above general formula (II-AB1) or (II-AB2) may be used. Wherein at least one of 'to R ₁₆ ' has a group represented by the general formulas (LC1-1) to (LC1-16) (for example, R _{5 of} -COOR ₅ is represented by the general formulas (LC1-1) to (LC1) -16) or a repeating unit represented by the following general formula (AI).

In general formula (AI),
R _b0 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms. Preferable substituents that the alkyl group for R _b0 may have include a hydroxyl group and a halogen atom. 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 or a methyl group.
A _b is an alkylene group, a divalent linking group having a monocyclic or polycyclic alicyclic hydrocarbon structure, a single bond, an ether group, an ester group, a carbonyl group, a carboxyl group, or a divalent group obtained by combining these. Represents. Preferably a single bond, -Ab ₁ -CO ₂ - is a linking group represented by. Ab ₁ is a linear, branched alkylene group, monocyclic or polycyclic cycloalkylene group, preferably a methylene group, an ethylene group, a cyclohexyl group, an adamantyl group, or a norbornyl group.
V represents a group represented by any one of the general formulas (LC1-1) to (LC1-16).

The repeating unit having a lactone structure usually has an optical isomer, but any optical isomer may be used. One optical isomer may be used alone, or a plurality of optical isomers may be mixed and used. When one kind of optical isomer is mainly used, the optical purity (ee) thereof is preferably 90 or more, more preferably 95 or more.
Specific examples of the repeating unit having a group having a lactone structure are given below, but the present invention is not limited thereto.

  The resin of the component (B) of the present invention preferably contains a repeating unit having an alicyclic hydrocarbon structure substituted with a polar group. This improves the substrate adhesion and developer compatibility. The alicyclic hydrocarbon isostructure substituted with a polar group is preferably an adamantyl group, a diadamantyl group, or a norbornane group. The polar group is preferably a hydroxyl group or a cyano group.

  Preferred examples of the alicyclic hydrocarbon structure substituted with a polar group include structures represented by the following general formulas (VIIa) to (VIId).

In general formulas (VIIa) to (VIIc),
R _{2c to} R _4c each independently represents a hydrogen atom, a hydroxyl group or a cyano group. However, at least one of R _{2c to} R _4c represents a hydroxyl group or a cyano group. Preferably, one or two of R _{2c to} R _4c are a hydroxyl group and the remaining is a hydrogen atom, more preferably two of R _{2c to} R _4c are a hydroxyl group and the remaining is a hydrogen atom.

As the repeating unit having a group represented by the general formulas (VIIa) to (VIId), at least one of R ₁₃ ′ to R ₁₆ ′ in the general formula (II-AB1) or (II-AB2) is Having the groups represented by the above general formulas (VIIa) to (VIId) (for example, R _{5 of} —COOR ₅ represents a group represented by the general formulas (VIIa) to (VIId)), or the following general formula Examples include the repeating units represented by (AIIa) to (AIIb).

In general formulas (AIIa) to (AIId),
R _1c represents a hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl group.

  Although the specific example of the repeating unit which has a structure represented by general formula (AIIa)-(AIId) is given to the following, this invention is not limited to these.

  The resin of the component (B) of the present invention may have a repeating unit represented by the following general formula (VIII).

In general formula (VIII):
Z ₂ represents —O— or —N (R ₄₁ ) —. R ₄₁ represents a hydrogen atom, a hydroxyl group, an alkyl group, or —OSO ₂ —R ₄₂ . R ₄₂ represents an alkyl group, a cycloalkyl group or a camphor residue. The alkyl group of R ₄₁ and R ₄₂ may be substituted with a halogen atom (preferably a fluorine atom) or the like.

  Examples of the repeating unit represented by the general formula (VIII) include the following specific examples, but the present invention is not limited thereto.

  The resin of the component (B) of the present invention preferably has a repeating unit having an alkali-soluble group, and more preferably has a repeating unit having a carboxyl group. By containing this, the resolution in contact hole applications increases. The repeating unit having a carboxyl group includes a repeating unit in which a carboxyl group is directly bonded to the main chain of the resin, such as a repeating unit of acrylic acid or methacrylic acid, or a carboxyl group in the main chain of the resin through a linking group. Any of the bonded repeating units is preferable, and the linking group may have a monocyclic or polycyclic hydrocarbon structure. Most preferred are acrylic acid and methacrylic acid.

  The resin of the component (B) of the present invention may further have a repeating unit having 1 to 3 groups represented by the general formula (F1). This improves line edge roughness performance.

In general formula (F1),
R _{50 to} R ₅₅ each independently represents a hydrogen atom, a fluorine atom or an alkyl group. However,
At least one of R _{50 to} R ₅₅ represents a fluorine atom or an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom.
Rxa represents a hydrogen atom or an organic group (preferably an acid-decomposable protective group, an alkyl group, a cycloalkyl group, an acyl group, or an alkoxycarbonyl group).

The alkyl group of R _{50 to} R ₅₅ may be substituted with a halogen atom such as a fluorine atom, a cyano group, etc., preferably an alkyl group having 1 to 3 carbon atoms, such as a methyl group or a trifluoromethyl group. be able to. R _{50 to} R ₅₅ are preferably all fluorine atoms.

  Examples of the organic group represented by Rxa include an acid-decomposable protecting group and an optionally substituted alkyl group, cycloalkyl group, acyl group, alkylcarbonyl group, alkoxycarbonyl group, alkoxycarbonylmethyl group, alkoxymethyl group. , 1-alkoxyethyl group is preferable.

  The repeating unit having the general formula (F1) is preferably a repeating unit represented by the following general formula (F2).

In general formula,
Rx represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms. Preferable substituents that the alkyl group of Rx may have include a hydroxyl group and a halogen atom.
Fa represents a single bond or a linear or branched alkylene group, preferably a single bond.
Fb represents a monocyclic or polycyclic hydrocarbon group.
Fc represents a single bond or a linear or branched alkylene group (preferably a single bond or a methylene group).
F ₁ represents a group represented by the general formula (F1).
p ₁ is an integer of 1 to 3.
The cyclic hydrocarbon group for Fb is preferably a cyclopentyl group, a cyclohexyl group, or a norbornyl group.

  Specific examples of the repeating unit having the structure of the general formula (F1) are shown below.

  The resin of the component (B) of the present invention may further contain a repeating unit that has an alicyclic hydrocarbon structure and does not exhibit acid decomposability. This can reduce the elution of low molecular components from the resist film to the immersion liquid during immersion exposure. Examples of such a repeating unit include 1-adamantyl (meth) acrylate, tricyclodecanyl (meth) acrylate, cyclohexyl (meth) acrylate, and the like.

  In addition to the above repeating structural units, the resin of component (B) of the present invention includes dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and general required characteristics of resist, resolving power and heat resistance. In order to adjust sensitivity and the like, various repeating structural units can be included.

  Examples of such repeating structural units include, but are not limited to, repeating structural units corresponding to the following monomers.

Thereby, the performance required for the resin of the component (B), in particular,
(1) Solubility in coating solvent,
(2) Film formability (glass transition point),
(3) Alkali developability,
(4) Membrane slip (hydrophobic, alkali-soluble group selection),
(5) Adhesion of unexposed part to substrate,
(6) Dry etching resistance,
Etc. can be finely adjusted.

  As such a monomer, for example, a compound having one addition polymerizable unsaturated bond selected from acrylic acid esters, methacrylic acid esters, acrylamides, methacrylamides, allyl compounds, vinyl ethers, vinyl esters, etc. Etc.

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

  In the component (B) resin, the molar ratio of each repeating structural unit is the resist dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and general resist performance required for resolving power and heat resistance. In order to adjust the sensitivity and the like, it is set as appropriate.

The following are mentioned as a preferable aspect of resin of (B) component of this invention.
(1) Consists of (meth) acrylate repeating units only.
(2) Those having a repeating unit represented by formula (II-AB)) (main chain type). However, in (2), for example, the following can be further mentioned.
(3) Those having a repeating unit represented by the general formula (II-AB), a repeating unit by a maleic anhydride derivative and a repeating unit by (meth) acrylate (hybrid type).

  In the resin of the component (B), the content of the repeating unit having a cyclic hydrocarbon structure and the partial structure represented by the general formula (I) in the same repeating unit is 1 to 70 mol% in all repeating structural units. Preferably, it is 3-50 mol%, More preferably, it is 5-40 mol%.

  In the resin of component (B), the content of the repeating unit having an acid-decomposable group is preferably 10 to 60 mol%, more preferably 20 to 50 mol%, still more preferably 25 to 40 mol in all repeating structural units. %.

  In the resin of the component (B), the content of the repeating unit having a partial structure containing the alicyclic hydrocarbon represented by the general formulas (pI) to (pV) is 20 to 50 mol% in all the repeating structural units. More preferably, it is 25-45 mol%, More preferably, it is 30-40 mol%.

  In the resin of the component (B), the content of the repeating unit represented by the general formula (II-AB) is preferably 10 to 60 mol%, more preferably 15 to 55 mol%, still more preferably in all repeating structural units. Is 20 to 50 mol%.

When the composition of the present invention is for ArF exposure, the resin preferably has no aromatic group from the viewpoint of transparency to ArF light.
The resin of the component (B) used in the present invention is preferably one in which all of the repeating units are composed of (meth) acrylate repeating units. In this case, all of the repeating units may be methacrylate, all of the repeating units may be acrylate, or a mixture of methacrylate / acrylate, but the acrylate repeating unit is preferably 50 mol% or less of the entire repeating unit.
More preferably, 5 to 80 mol% of repeating units having a cyclic hydrocarbon structure and a partial structure represented by the general formula (I) in the same repeating unit, and fats represented by the general formulas (pI) to (pV) It is a resin containing 20 to 50 mol% of repeating units having a partial structure containing a cyclic hydrocarbon, and is substituted with 20 to 50 mol% of repeating units having the lactone structure as a further repeating unit, and / or substituted with the polar group It is a copolymer containing 5 to 30 mol% of repeating units having an alicyclic hydrocarbon structure, or a copolymer containing 0 to 20 mol% of other repeating units.
As a particularly preferred resin, a repeating unit having an acid-decomposable group represented by the following general formulas (ARA-1) to (ARA-5) represented by 5 to 80 mol% represented by the general formula (I-1a) A resin containing 20 to 50 mol% of units, and as further repeating units, 20 to 50 mol% of repeating units having a lactone group represented by the following general formulas (ARL-1) to (ARL-6), and / or Or a copolymer containing 5 to 30 mol% of a repeating unit having an alicyclic hydrocarbon structure substituted with a polar group represented by the following general formulas (ARH-1) to (ARH-3), or further a carboxyl group, Or it is a copolymer containing 5-20 mol% of the repeating unit which has a structure represented by general formula (F1), and an alicyclic hydrocarbon structure, and does not show acid decomposability.
(Wherein Rxy1 represents a hydrogen atom or a methyl group, and Rxa1 and Rxb1 represent a methyl group or an ethyl group.)

The resin having a repeating unit having a group represented by the general formula (I-1) or (I-2) of the present invention is a novel compound.
The resin having a repeating unit represented by any one of the general formulas (I-1a) to (I-4a) of the present invention is a novel compound.

The resin of component (B) used in the present invention can be synthesized according to a conventional method (for example, radical polymerization). For example, as a general synthesis method, a monomer polymerization method in which a monomer species and an initiator are dissolved in a solvent and the polymerization is performed by heating, and a solution of the monomer species and the initiator is dropped into the heating solvent over 1 to 10 hours. The dropping polymerization method is added, and the dropping polymerization method is preferable. Examples of the reaction solvent include ethers such as tetrahydrofuran, 1,4-dioxane, diisopropyl ether, ketones such as methyl ethyl ketone and methyl isobutyl ketone, ester solvents such as ethyl acetate, amide solvents such as dimethylformamide and dimethylacetamide, Furthermore, the solvent which melt | dissolves the composition of this invention like the below-mentioned propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, and cyclohexanone is mentioned. More preferably, the polymerization is performed using the same solvent as the solvent used in the positive photosensitive composition of the present invention. Thereby, the generation of particles during storage can be suppressed.
The polymerization reaction is preferably performed in an inert gas atmosphere such as nitrogen or argon. As a polymerization initiator, a commercially available radical initiator (azo initiator, peroxide, etc.) is used to initiate the polymerization. As the radical initiator, an azo initiator is preferable, and an azo initiator having an ester group, a cyano group, or a carboxyl group is preferable. Preferred examples of the initiator include azobisisobutyronitrile, azobisdimethylvaleronitrile, dimethyl 2,2′-azobis (2-methylpropionate) and the like. 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 5 to 50% by mass, preferably 10 to 30% by mass. The reaction temperature is usually 10 ° C to 150 ° C, preferably 30 ° C to 120 ° C, more preferably 60-100 ° C.
The weight average molecular weight of the resin of the component (B) according to the present invention is preferably 1,000 to 200,000 as a polystyrene conversion value by GPC method, and more preferably 3,000 to
20,000, most preferably 5,000 to 15,000. By setting the weight average molecular weight to 1,000 to 200,000, deterioration of heat resistance and dry etching resistance can be prevented, developability is deteriorated, and viscosity is increased, resulting in deterioration of film forming property. Can be prevented. The molecular weight distribution is usually 1 to 5, preferably 1 to 3, more preferably 1 to 2. The smaller the molecular weight distribution, the better the resolution and the resist shape, and the smoother the side wall of the resist pattern, the better the roughness.

In the positive photosensitive composition of the present invention, the blending amount of all the resins according to the present invention in the entire composition is preferably 50 to 99.99% by mass, more preferably 60 to 99.0% in the total solid content. % By mass.
In the present invention, the resins may be used alone or in combination.

(B2) Resin that does not have a group that decomposes by the action of an acid The positive photosensitive composition of the present invention has a resin that does not have a group that decomposes by the action of an acid (hereinafter referred to as “resin of component (B2)”. May be included).
“No acid-decomposable group” means that there is no or very little decomposability due to the action of an acid in an image forming process in which the positive photosensitive composition of the present invention is usually used. It has no group that contributes to image formation by decomposition. Examples of such a resin include a resin having an alkali-soluble group and a resin having a group that decomposes by the action of an alkali and improves the solubility in an alkali developer.

  As the resin of the component (B2), for example, a resin having at least one repeating unit derived from a (meth) acrylic acid derivative and / or an alicyclic olefin derivative is preferable.

Examples of the alkali-soluble group in the component (B2) resin include, for example, a carboxyl group, a phenolic hydroxyl group, an aliphatic hydroxyl group substituted at the 1- or 2-position with an electron-withdrawing group, and an electron-withdrawing group. An amino group (for example, a sulfonamide group, a sulfonimide group, a bissulfonylimide group), a methylene group substituted with an electron-withdrawing group, or a methine group (for example, a methylene group substituted with at least two selected from a ketone group and an ester group) Group, methine group).
The group that decomposes by the action of alkali in the resin of component (B2) and increases the solubility in an alkaline developer is preferably, for example, a lactone group or an acid anhydride group, more preferably a lactone group. .

The resin as the component (B2) may further have a repeating unit having a functional group other than those described above. As the repeating unit having another functional group, a repeating unit having an appropriate functional group can be selected in consideration of dry etching resistance, hydrophilicity / hydrophobicity, interaction property and the like.
Examples of the repeating unit having another functional group include a repeating unit having a polar functional group such as a hydroxyl group, a cyano group, a carbonyl group, and an ester group, a repeating unit having a monocyclic or polycyclic hydrocarbon structure, and a fluoroalkyl group. And a repeating unit having a plurality of these functional groups.

  The weight average molecular weight of the resin of component (B2) is preferably 3000 to 30000, more preferably 5000 to 15000, and still more preferably 6000 to 12000 as a polystyrene-converted value by the GPC method.

  Although the preferable specific example of resin of (B2) component is shown below, this invention is not limited to this.

  The amount of the component (B2) resin added is usually 0 to 50% by mass with respect to the component (B) resin, preferably 0 to 30% by mass, more preferably 0 to 20% with respect to the component (B) resin. % By mass.

[3] (C) A solubility control compound having a molecular weight of 3000 or less, having at least one selected from an alkali-soluble group, a hydrophilic group, and an acid-decomposable group. The positive photosensitive composition of the present invention comprises an alkali-soluble group, a hydrophilic group In addition, a dissolution control compound having a molecular weight of 3000 or less (hereinafter also referred to as “component (C)” or “solubility control compound”) having at least one selected from acid-decomposable groups may be contained.
Examples of the dissolution control compound include a carboxyl group, a sulfonylimide group, a compound having an alkali-soluble group such as a hydroxyl group substituted at the α-position with a fluoroalkyl group, a hydroxyl group, a lactone group, a cyano group, an amide group, a pyrrolidone group, a sulfone group. A compound having a hydrophilic group such as an amide group or a compound containing a group capable of decomposing by the action of an acid to release an alkali-soluble group or a hydrophilic group is preferable. The group capable of decomposing by the action of an acid to release an alkali-soluble group or a hydrophilic group is preferably a group in which a carboxyl group or a hydroxyl group is protected with an acid-decomposable group. In order not to lower the permeability of 220 nm or less as the dissolution control compound, it is preferable to use a compound that does not contain an aromatic ring, or to use a compound having an aromatic ring in an amount of 20 wt% or less based on the solid content of the composition.
Preferred dissolution control compounds include carboxylic acid compounds having an alicyclic hydrocarbon structure such as adamantane (di) carboxylic acid, norbornane carboxylic acid, and cholic acid, or compounds in which the carboxylic acid is protected with an acid-decomposable group, and polyols such as saccharides. Or a compound having its hydroxyl group protected with an acid-decomposable group is preferred.

  The molecular weight of the dissolution controlling compound in the present invention is 3000 or less, preferably 300 to 3000, and more preferably 500 to 2500.

  The addition amount of the dissolution control compound is preferably 3 to 40% by mass, more preferably 5 to 20% by mass, based on the solid content of the positive photosensitive composition.

  Specific examples of the dissolution control compound are shown below, but the present invention is not limited thereto.

[4] (D) Basic compound The positive photosensitive composition of the present invention can be used in order to reduce the change in performance over time from exposure to heating, or to control the diffusibility of acid generated by exposure in the film ( D) It is preferable to contain a basic compound.
Examples of basic compounds include nitrogen-containing basic compounds and onium salt compounds.
Preferable nitrogen-containing basic compound structures include compounds having partial structures represented by the following formulas (A) to (E).

Here, R ²⁵⁰ , R ²⁵¹ and R ²⁵² are each independently a hydrogen atom, an alkyl having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, And R ²⁵⁰ and R ²⁵¹ may combine with each other to form a ring. These may have a substituent. Examples of the alkyl group and cycloalkyl group having a substituent include an aminoalkyl group having 1 to 20 carbon atoms, an aminocycloalkyl group having 3 to 20 carbon atoms, and 1 to 1 carbon atoms. A 20 hydroxyalkyl group or a C 3-20 hydroxycycloalkyl group is preferred.
These may contain an oxygen atom, a sulfur atom, or a nitrogen atom in the alkyl chain.

R ²⁵³ , R ²⁵⁴ , R ²⁵⁵ and R ²⁵⁶ each independently represents an alkyl group having 1 to 20 carbon atoms or a cycloalkyl group having 3 to 20 carbon atoms.

  Preferable compounds include guanidine, aminopyrrolidine, pyrazole, pyrazoline, piperazine, aminomorpholine, aminoalkylmorpholine, and piperidine, and may have a substituent. More preferable compounds include compounds having an imidazole structure, a diazabicyclo structure, an onium hydroxide structure, an onium carboxylate structure, a trialkylamine structure, an aniline structure or a pyridine structure, an alkylamine derivative having a hydroxyl group and / or an ether bond, a hydroxyl group and / or Or the aniline derivative which has an ether bond etc. can be mentioned.

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

  These basic compounds are used alone or in combination of two or more. The usage-amount of a basic compound is 0.001-10 mass% normally based on solid content of a positive photosensitive composition, Preferably it is 0.01-5 mass%. In order to obtain a sufficient addition effect, 0.001% by mass or more is preferable, and 10% by mass or less is preferable in terms of sensitivity and developability of the non-exposed area.

[5] (E) Fluorine and / or silicon surfactant The positive photosensitive composition of the present invention further comprises a fluorine and / or silicon surfactant (a fluorine surfactant and a silicon surfactant). , A surfactant containing both a fluorine atom and a silicon atom), or preferably two or more thereof.

  When the positive photosensitive composition of the present invention contains fluorine and / or a silicon-based surfactant, adhesion and development with good sensitivity and resolution when using an exposure light source of 250 nm or less, particularly 220 nm or less. A resist pattern with few defects can be provided.

  Examples of these fluorine and / or silicon surfactants 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, the surfactant is derived from a fluoroaliphatic compound produced by a telomerization method (also called telomer method) or an oligomerization method (also called 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. It 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 Coalesce, etc. Can.

  The amount of fluorine and / or silicon-based surfactant used is preferably 0.0001 to 2% by mass, more preferably 0.001 to 1% by mass, based on the total amount of the positive photosensitive composition (excluding the solvent). %.

[6] (F) Organic Solvent The positive photosensitive composition of the present invention is used by dissolving the above components in a predetermined organic solvent.
Examples of the organic solvent that can be used include ethylene dichloride, cyclohexanone, cyclopentanone, 2-heptanone, γ-butyrolactone, methyl ethyl ketone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 2-methoxyethyl acetate, ethylene glycol monoethyl. Ether acetate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, toluene, ethyl acetate, methyl lactate, ethyl lactate, methyl methoxypropionate, ethyl ethoxypropionate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, N, N -Dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, tetrahydrofuran, etc.

In the present invention, the organic solvent may be used alone or in combination, but it is preferable to use a mixed solvent containing two or more solvents having different functional groups. As a result, the solubility of the material is increased, and not only the generation of particles over time can be suppressed, but also a good pattern profile can be obtained. Preferable functional groups contained in the solvent include ester groups, lactone groups, hydroxyl groups, ketone groups, and carbonate groups. As the mixed solvent having different functional groups, the following mixed solvents (S1) to (S5) are preferable.
(S1) A mixed solvent in which a solvent containing a hydroxyl group and a solvent not containing a hydroxyl group are mixed.
(S2) A mixed solvent in which a solvent having an ester structure and a solvent having a ketone structure are mixed.
(S3) A mixed solvent obtained by mixing a solvent having an ester structure and a solvent having a lactone structure.
(S4) A mixed solvent obtained by mixing a solvent having an ester structure, a solvent having a lactone structure, and a solvent containing a hydroxyl group.
(S5) A mixed solvent obtained by mixing a solvent having an ester structure, a solvent having a carbonate structure, and a solvent containing a hydroxyl group.
As a result, the generation of particles during storage of the resist solution can be reduced, and the generation of defects during application can be suppressed.

  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 and cyclohexanone are most preferred.

Examples of the solvent having a ketone structure include cyclohexanone and 2-heptanone, and cyclohexanone is preferable.
Examples of the solvent having an ester structure include propylene glycol monomethyl ether acetate, ethyl ethoxypropionate, and butyl acetate, and propylene glycol monomethyl ether acetate is preferable.
Examples of the solvent having a lactone structure include γ-butyrolactone.
Examples of the solvent having a carbonate structure include propylene carbonate and ethylene carbonate, with propylene carbonate being preferred.
The mixing ratio (mass) 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 mass or more of a solvent not containing a hydroxyl group is particularly preferred from the viewpoint of coating uniformity.
The mixing ratio (mass) of the solvent having an ester structure and the solvent having a ketone structure is 1/99 to 99/1, preferably 10/90 to 90/10, and more preferably 40/60 to 80/20. . A mixed solvent containing 50% by mass or more of a solvent having an ester structure is particularly preferable from the viewpoint of coating uniformity.
The mixing ratio (mass) of the solvent having an ester structure and the solvent having a lactone structure is 70/30 to 99/1, preferably 80/20 to 99/1, and more preferably 90/10 to 99/1. . A mixed solvent containing 70% by mass or more of a solvent having an ester structure is particularly preferable from the viewpoint of stability over time.
When mixing a solvent having an ester structure, a solvent having a lactone structure, and a solvent containing a hydroxyl group, the solvent having an ester structure is 30 to 80% by weight, the solvent having a lactone structure is 1 to 20% by weight, and the hydroxyl group is contained. It is preferable to contain 10 to 60% by weight of the solvent.
When mixing a solvent having an ester structure, a solvent having a carbonate structure and a solvent containing a hydroxyl group, the solvent having an ester structure is 30 to 80% by weight, the solvent having a carbonate structure is 1 to 20% by weight, and the hydroxyl group is contained. It is preferable to contain 10 to 60% by weight of the solvent.
A preferable embodiment of these solvents is a solvent containing an alkylene glycol monoalkyl ether carboxylate (preferably propylene glycol monomethyl ether acetate), more preferably a mixed solvent of an alkylene glycol monoalkyl ether carboxylate and another solvent, The other solvent is at least one selected from a functional group selected from a hydroxyl group, a ketone group, a lactone group, an ester group, an ether group and a carbonate group, or a solvent having a plurality of these functional groups. The most preferred mixed solvent is a mixed solvent of propylene glycol monomethyl ether acetate and at least one selected from ethyl lactate, γ-butyrolactone, propylene glycol monomethyl ether, butyl acetate, and cyclohexanone.
The development defect performance can be improved by selecting an optimum solvent.

<Other additives>
If necessary, the positive photosensitive composition of the present invention may further contain a dye, a plasticizer, a surfactant other than the component (E), a photosensitizer, and the like.

In the present invention, a surfactant other than the above (E) fluorine-based and / or silicon-based surfactant may be added. Specifically, nonionic interfaces such as polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, polyoxyethylene / polyoxypropylene block copolymers, sorbitan aliphatic esters, polyoxyethylene sorbitan aliphatic esters, etc. Mention may be made of activators.
These surfactants may be added alone or in some combination.

(Pattern formation method)
The positive photosensitive composition of the present invention is used by dissolving the above components in a predetermined organic solvent, preferably the mixed solvent, filtering the solution, and applying the solution on a predetermined support as follows. The filter used for filter filtration is preferably made of polytetrafluoroethylene, polyethylene, or nylon of 0.1 microns or less, more preferably 0.05 microns or less, and still more preferably 0.03 microns or less.

For example, a positive photosensitive composition is coated on a substrate (eg, silicon / silicon dioxide coating) used in the manufacture of precision integrated circuit elements by a suitable coating method such as a spinner or coater, dried, and photosensitive. A film is formed.
The photosensitive film is irradiated with actinic rays or radiation through a predetermined mask, preferably baked (heated), developed and rinsed. Thereby, a good pattern can be obtained.
Exposure (immersion exposure) may be performed by filling a liquid (immersion medium) having a higher refractive index than air between the photosensitive film and the lens during irradiation with actinic rays or radiation. Thereby, resolution can be improved. As the immersion medium to be used, any liquid can be used as long as it has a higher refractive index than air, but pure water is preferred. Further, an overcoat layer may be further provided on the photosensitive film so that the immersion medium and the photosensitive film do not come into direct contact with each other during the immersion exposure. Thereby, the elution of the composition from the photosensitive film to the immersion medium is suppressed, and development defects are reduced.

  Examples of the actinic ray or radiation include infrared light, visible light, ultraviolet light, far ultraviolet light, X-ray, electron beam, etc., but preferably far ultraviolet light having a wavelength of 250 nm or less, more preferably 220 nm or less. Specifically, KrF excimer laser (248 nm), ArF excimer laser (193 nm), F2 excimer laser (157 nm), X-ray, electron beam, etc., ArF excimer laser, F2 excimer laser, EUV (13 nm), electron A beam is preferred.

In the development step, an alkaline developer is used as follows. As an alkaline developer of the resist composition, inorganic hydroxides such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia, primary amines such as ethylamine and n-propylamine, Secondary amines such as diethylamine and di-n-butylamine, tertiary amines such as triethylamine and methyldiethylamine, alcohol amines such as dimethylethanolamine and triethanolamine, tetramethylammonium hydroxide,
Alkaline aqueous solutions such as quaternary ammonium salts such as tetraethylammonium hydroxide and cyclic amines such as pyrrole and pihelidine can be used.
Furthermore, alcohols and surfactants can be added in appropriate amounts to the alkaline developer.
The alkali concentration of the alkali developer is usually from 0.1 to 20% by mass.
The pH of the alkali developer is usually from 10.0 to 15.0.

  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 Compound (I-1b-1 (Rxa = Me)))
9 g of 3-carboxy-1-adamantane methacrylate was dissolved in 150 ml of tetrahydrofuran, and 5.4 g of carbonyldiimidazole was added thereto. The mixture was reacted under reflux for 1 hour, allowed to cool, and then 3.5 g of methanesulfonamide was added thereto. A solution prepared by dissolving 5.4 g of 1.8-diazabicycloundecene in 30 ml of tetrahydrofuran was added dropwise to the reaction solution over 30 minutes and reacted at room temperature for 24 hours. 500 ml of 1N hydrochloric acid aqueous solution was added to the reaction solution, and this was extracted three times with 300 ml of ethyl acetate. The organic phase was washed with distilled water, dried and concentrated to give a crude product. When this was washed with isopropanol, 7.5 g of compound (I-1b-1 (Rxa = Me)) was obtained.

Synthesis Example 2 (Synthesis of Compound (I-1b-2 (Rxa = Me)))
The synthesis was performed in the same manner as in Synthesis Example 1 except that methanesulfonamide was changed to camphorsulfonamide.

Synthesis Example 3 (Synthesis of resin (RA-1))
Under a nitrogen stream, 5.8 g of propylene glycol monomethyl ether acetate and 3.9 g of propylene glycol monomethyl ether were placed in a three-necked flask and heated to 80 ° C. To this, 6.8 g of compound (I-1b-1 (Rxa = Me)), 6.8 g of γ-butyrolactone methacrylate, 10.5 g of 2- (1-adamantyl) isopropyl-2-methacrylate, polymerization initiator V-601 ( Wako Pure Chemical Industries, Ltd.) was added dropwise over 6 hours with 8 mol% dissolved in 52 g of propylene glycol monomethyl ether acetate and 35 g of propylene glycol monomethyl ether. After completion of dropping, the reaction was further carried out at 80 ° C. for 2 hours. The reaction solution was allowed to cool and then poured into 700 ml of hexane / 300 ml of ethyl acetate, and the precipitated powder was collected by filtration and dried to obtain 20 g of Resin (RA-1). The weight average molecular weight of the obtained resin was 8600 in terms of standard polystyrene, and the dispersity (Mw / Mn) was 1.80.
Resins (RA-2) to (RA-15) and resins (PX) to (PZ) were synthesized in the same manner.

  Hereinafter, structures of resins (RA-1) to (RA-15) and resins (PX) to (PZ) are shown.

Examples 1-20 and Comparative Examples 1-3
<Resist preparation>
The components shown in Table 1 below were dissolved in a solvent to prepare a solution having a solid content concentration of 8% by mass, and this was filtered through a 0.03 m polyethylene filter to prepare a positive resist solution. The prepared positive resist solution was evaluated by the following method, and the results are also shown in Table 1.

The abbreviations in Table 1 are shown below.
[Basic compounds]
TPI: 2,4,5-triphenylimidazole TPSA: triphenylsulfonium acetate DIA: 2,6-diisopropylaniline DCMA: dicyclohexylmethylamine TPA: tripentylamine HAP: hydroxyantipyrine TBAH: tetrabutylammonium hydroxide TMEA: Tris ( Methoxyethoxyethyl) amine PEA: N-phenyldiethanolamine [Surfactant]
W-1: MegaFuck F176 (Dainippon Ink Chemical Co., Ltd.) (Fluorine)
W-2: Megafuck R08 (Dainippon Ink Chemical Co., Ltd.) (fluorine and silicon)
W-3: Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) (silicon-based)
W-4: Troisol S-366 (manufactured by Troy Chemical Co., Ltd.)
〔solvent〕
S1: Propylene glycol methyl ether acetate S2: 2-heptanone S3: Cyclohexanone S4: γ-butyrolactone S5: Propylene glycol methyl ether S6: Ethyl lactate S7: Propylene carbonate

<Resist evaluation>
An antireflection film DUV-42 manufactured by Brewer Science Co., Ltd. was uniformly applied to 600 Å on a silicon substrate subjected to hexamethyldisilazane treatment with a spin coater, dried on a hot plate at 100 ° C. for 90 seconds, and then at 190 ° C. Heat drying was performed for 240 seconds. Thereafter, each positive resist solution was applied by a spin coater and dried at 110 ° C. for 90 seconds to form a 180 nm resist film.
This resist film was exposed with an ArF excimer laser stepper (SML NA = 0.75, 2/3 ring zone) through a mask, and heated on a hot plate at 120 ° C. for 90 seconds immediately after the exposure. Further, the resist film was developed with an aqueous 2.38 mass% tetramethylammonium hydroxide solution at 23 ° C. for 60 seconds, rinsed with pure water for 30 seconds, and then dried to obtain a line pattern.

Pattern collapse evaluation method:
When the line width of the line pattern formed by increasing the exposure amount from the optimal exposure amount is reduced to the optimal exposure amount, the exposure amount for reproducing the 80 nm line and space 1: 1 mask pattern Defined with line width that resolves without falling down. The smaller the value, the finer pattern is resolved without falling, and the pattern collapse is less likely to occur and the resolution is higher.
Line edge roughness evaluation method:
Using a length-measuring scanning electron microscope (SEM), observe a 80 nm line-and-space 1: 1 pattern and measure the distance from the reference line where the edge of the line pattern should be 5 μm long. 20 points were measured by SEM (Hitachi, Ltd. S-8840), the standard deviation was obtained, and 3σ was calculated. A smaller value indicates better performance.

  From the results in Table 1, it is clear that the positive photosensitive composition of the present invention is excellent in pattern collapse and line edge roughness.

(Immersion exposure)
<Resist preparation>
The components of Table 1, Examples 1 to 20 and Comparative Examples 1 to 3 were dissolved in a solvent to prepare a solution having a solid content concentration of 6% by mass, and this was filtered through a 0.03 μm polyethylene filter to obtain a positive resist solution. It was adjusted. The adjusted positive resist solution was evaluated by the following method.
<Resolution 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. The resist composition prepared thereon was applied and baked at 115 ° C. for 60 seconds to form a 150 nm resist film. The wafer thus obtained was subjected to two-beam interference exposure (wet exposure) using pure water as the immersion liquid. In the two-beam interference exposure (wet), as shown in FIG. 1, a laser 1, an aperture 2, a shutter 3, three reflecting mirrors 4, 5, 6 and a condenser lens 7 are used, and a prism 8, liquid The wafer 10 having an antireflection film and a resist film was exposed through an immersion liquid (pure water) 9. The wavelength of the laser 1 was 193 nm, and the prism 8 forming a 65 nm line and space pattern was used. Immediately after the exposure, the resist pattern obtained by heating at 115 ° C. for 90 seconds, developing with an aqueous tetramethylammonium hydroxide solution (2.38%) for 60 seconds, rinsing with pure water, and spin drying is then applied to a scanning electron microscope. (Hitachi S-9260) was used for observation. When the compositions of Examples 1 to 20 were used, a 65 nm line and space pattern was resolved without causing pattern collapse. When the compositions of Comparative Examples 1 to 3 were used, a 65 nm line and space pattern was resolved, but pattern collapse was observed in some patterns.
It is clear that the positive photosensitive composition of the present invention has a good image forming ability even in an exposure method using an immersion liquid.

It is the schematic of a two-beam interference exposure experiment apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Laser 2 Aperture 3 Shutter 4, 5, 6 Reflection mirror 7 Condensing lens 8 Prism 9 Immersion liquid 10 Wafer having antireflection film and resist film 11 Wafer stage

Claims (10)

(A) a compound that generates an acid upon irradiation with an actinic ray or radiation,
(B) a positive photosensitive composition containing a resin that decomposes by the action of an acid and increases the solubility in an alkaline developer,
The positive photosensitive composition, wherein the resin of component (B) has a repeating unit having a cyclic hydrocarbon structure and a partial structure represented by the following general formula (I) in the same repeating unit.

The positive photosensitive composition according to claim 1, wherein the resin of component (B) has a repeating unit having a group represented by the following general formula (I-1) or (I-2). .

In general formulas (I-1) and (I-2),
Xb represents a linking group having a monocyclic or polycyclic hydrocarbon structure.
Ra ₁ represents an organic group.
Xb and Ra ₁ may combine to form a ring structure. The positive photosensitive composition according to claim 1, wherein the resin of component (B) has a repeating unit represented by any one of the following general formulas (I-1a) to (I-4a). .

In the general formulas (I-1a) to (I-4a),
Rxa represents a hydrogen atom, an alkyl group or a cyano group.
Xc represents a group represented by the general formula (I-1) or (I-2).
Ra ₁ represents an organic group.
Ra _{2 to} Ra ₄ each independently represents a hydrogen atom or an organic group.
n represents 0 or 1.   The positive photosensitive composition according to any one of claims 1 to 3, wherein the resin as the component (B) further has an acid-decomposable repeating unit having an alicyclic hydrocarbon structure.   The positive photosensitive composition according to claim 1, wherein the resin as the component (B) further has a repeating unit having a lactone structure. A polymerizable compound having a group represented by the following general formula (I-1) or (I-2).

In general formulas (I-1) and (I-2),
Xb represents a linking group having a monocyclic or polycyclic hydrocarbon structure.
Ra ₁ represents an organic group.
Xb and Ra ₁ may combine to form a ring structure. A polymerizable compound represented by any one of the following general formulas (I-1b) to (I-4b).

In the general formulas (I-1b) to (I-4b),
Rxa represents a hydrogen atom, an alkyl group or a cyano group.
Xc represents a group represented by the general formula (I-1) or (I-2).
Ra ₁ represents an organic group.
Ra _{2 to} Ra ₄ each independently represents a hydrogen atom or an organic group.
n represents 0 or 1. A resin having a repeating unit having a group represented by the following general formula (I-1) or (I-2).

In general formulas (I-1) and (I-2),
Xb represents a linking group having a monocyclic or polycyclic hydrocarbon structure.
Ra ₁ represents an organic group.
Xb and Ra ₁ may combine to form a ring structure. A resin having a repeating unit represented by any one of the following general formulas (I-1a) to (I-4a).

In the general formulas (I-1a) to (I-4a),
Rxa represents a hydrogen atom, an alkyl group or a cyano group.
Xc represents a group represented by the general formula (I-1) or (I-2).
Ra ₁ represents an organic group.
Ra _{2 to} Ra ₄ each independently represents a hydrogen atom or an organic group.
n represents 0 or 1.   A pattern forming method comprising a step of forming a photosensitive film from the positive photosensitive composition according to claim 1, and exposing and developing the photosensitive film.

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