JP2008046582A - Positive resist composition, resin used for the positive resist composition, compound used for synthesis of the resin, and pattern forming method using the positive resist composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a positive resist composition for use in the production process of a semiconductor such as IC, in the production of a circuit board of liquid crystal, thermal head and the like or in other photofabrication processes, and a pattern forming method using the same, and to provide a positive resist composition ensuring that the collapse of the resist pattern and deterioration of the profile due to time delay between exposure and PEB less occur not only at the normal exposure (dry exposure) but also at the immersion exposure and ensuring good followability for an immersion liquid at the liquid immersion exposure, and a pattern forming method using the same. <P>SOLUTION: The positive resist composition comprises: (A) a resin which has a monocyclic or polycyclic alicyclic hydrocarbon structure and of which solubility in an alkali developer increases under an action of an acid; (B) a compound capable of generating an acid upon irradiation with actinic rays or radiation; (C) a resin having at least one of a fluorine atom and a silicon atom; and (D) a solvent. The pattern forming method using the positive resist composition is also provided. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

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

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

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

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

Examples of apparatuses in which this effect is applied to the transfer of a fine image pattern of a semiconductor element are introduced in Patent Document 1 (Japanese Patent Laid-Open No. 57-153433), Patent Document 2 (Japanese Patent Laid-Open No. 7-220990), and the like. Yes.
Recent progress in immersion exposure technology is described in Non-Patent Document 1 (SPIE Proc 4688, 11 (2002)), Non-Patent Document 2 (J. Vac. Sci. Tecnol. B 17 (1999)), Non-Patent Document 3 (SPIE Proc 3999, 2 (2000)), Patent Document 3 (Japanese Patent Laid-Open No. 10-303114), and the like. In the case of using an ArF excimer laser as a light source, pure water (refractive index of 1.44 at 193 nm) is considered to be most promising as an immersion liquid in terms of handling safety, transmittance at 193 nm, and refractive index. When an F ₂ excimer laser is used as a light source, a solution containing fluorine has been studied from the balance between transmittance and refractive index at 157 nm. However, a sufficient product has not yet been seen in terms of environmental safety and refractive index. It has not been issued. From the degree of immersion effect and the degree of completeness of the resist, the immersion exposure technique is considered to be installed in the ArF exposure machine earliest.

Since the resist for KrF excimer laser (248 nm), an image forming method called chemical amplification has been used as an image forming method for a resist in order to compensate for sensitivity reduction due to light absorption. Explaining by taking a positive chemical amplification image forming method as an example, the acid generator in the exposed area is decomposed by exposure to generate an acid upon exposure, and the generated acid is reacted as a reaction catalyst by post exposure baking (PEB). Is used to change an alkali-insoluble group to an alkali-soluble group, and an exposed portion is removed by alkali development.
Although the resist for ArF excimer laser (wavelength: 193 nm) using this chemical amplification mechanism is becoming mainstream at present, the resist profile change due to the placement between exposure and PEB is not sufficiently suppressed, and improvement has been desired. .

In addition, when a chemically amplified resist is applied to immersion exposure, the resist layer comes into contact with the immersion liquid at the time of exposure, so that the resist layer is altered and components that adversely affect the immersion liquid are leached from the resist layer. Has been pointed out. Patent Document 4 (International Publication WO 2004-068242 Pamphlet) describes an example in which resist performance changes by immersing a resist for ArF exposure in water before and after exposure, and points to a problem in immersion exposure. .
In the immersion exposure process, when exposure is performed using a scanning immersion exposure machine, the exposure speed decreases unless the immersion liquid moves following the movement of the lens. Concerned about giving. In the case where the immersion liquid is water, it is desirable that the resist film be hydrophobic so that water followability is better.

JP-A-57-153433 JP-A-7-220990 JP-A-10-303114 International Publication WO 2004-068242 Pamphlet Proc. SPIE, 2002, Vol. 4688, p. 11 J.Vac.Sci.Tecnol.B 17 (1999) Proc. SPIE, 2000, Vol. 3999, p. 2

  An object of the present invention is that not only in normal exposure (dry exposure) but also in liquid immersion exposure, there is little resist pattern collapse and profile deterioration due to placement between exposure and PEB, and liquid immersion in liquid immersion exposure is also possible. To provide a positive resist composition having good followability to a liquid, a resin used in the positive resist composition, a compound used in the synthesis of the resin, and a pattern forming method using the positive resist composition It is.

  The present invention is a positive resist composition having the following constitution, a resin used in the positive resist composition, a compound used in the synthesis of the resin, and a pattern forming method using the positive resist composition. The above object of the present invention is achieved.

(1) (A) a resin having a monocyclic or polycyclic alicyclic hydrocarbon structure and having increased solubility in an alkali developer by the action of an acid;
(B) a compound that generates an acid upon irradiation with an actinic ray or radiation,
A positive resist composition comprising (C) a resin having at least one of a fluorine atom and a silicon atom, and (D) a solvent.

  (2) The positive resist composition as described in (1), wherein the resin (C) is solid at 25 ° C.

  (3) The positive resist composition as described in (1) or (2), wherein the glass transition temperature of the resin (C) is in the range of 50 to 200 ° C.

  (4) The positive resist composition as described in any one of (1) to (3), wherein the resin (C) has a group represented by the following general formula (F3a).

In general formula (F3a),
R _62a and R _63a each independently represents an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom. R _62a and R _63a may be connected to each other to form a ring.
R _64a represents a hydrogen atom, a fluorine atom or an alkyl group.

  (5) The positive type according to any one of (1) to (3), wherein the resin (C) has groups represented by the following general formulas (CS-1) to (CS-3): Resist composition.

In general formulas (CS-1) to (CS-3),
R _{12 to} R ₂₆ each independently represents a linear or branched alkyl group or a cycloalkyl group.
L < ₃ > -L < ₅ > represents a single bond or a bivalent coupling group.

(6) The positive electrode according to any one of (1) to (3), wherein the resin (C) is any resin selected from the following (C-1) to (C-6): Type resist composition.
(C-1) A resin having a repeating unit (a) having a fluoroalkyl group.
(C-2) A resin having a repeating unit (b) having a trialkylsilyl group or a cyclic siloxane structure.
(C-3) Resin having a repeating unit (a) having a fluoroalkyl group and a repeating unit (c) having a branched alkyl group, a cycloalkyl group, a branched alkenyl group, a cycloalkenyl group or an aryl group .
(C-4) a repeating unit (b) having a trialkylsilyl group or a cyclic siloxane structure and a repeating unit having a branched alkyl group, cycloalkyl group, branched alkenyl group, cycloalkenyl group or aryl group (c ).
(C-5) A resin having a repeating unit (a) having a fluoroalkyl group and a repeating unit (b) having a trialkylsilyl group or a cyclic siloxane structure.
(C-6) a repeating unit (a) having a fluoroalkyl group, a repeating unit (b) having a trialkylsilyl group or a cyclic siloxane structure, a branched alkyl group, a cycloalkyl group, a branched alkenyl group, A resin having a repeating unit (c) having a cycloalkenyl group or an aryl group.

  (7) The positive resist composition as described in any one of (1) to (3), wherein the resin (C) has a repeating unit represented by the following general formula (Ia).

In general formula (Ia):
Rf represents a fluorine atom or an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom.
R ₁ represents an alkyl group.
R ₂ represents a hydrogen atom or an alkyl group.

  (8) Any of (1) to (3), wherein the resin (C) has a repeating unit represented by the following general formula (II) and a repeating unit represented by the following general formula (III) A positive resist composition as described above.

In general formulas (II) and (III):
Rf represents a fluorine atom or an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom.
R ₃ represents an alkyl group, a cycloalkyl group, an alkenyl group or a cycloalkenyl group.
R ₄ represents an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, a trialkylsilyl group, or a group having a cyclic siloxane structure.
L ₆ represents a single bond or a divalent linking group.
0 <m <100.
0 <n <100.

  (9) A compound represented by the following general formula (I):

In general formula (I),
Rf represents a fluorine atom or an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom.
R ₁ represents an alkyl group.
R ₂ represents a hydrogen atom or an alkyl group.

  (10) A resin having a repeating unit represented by the following general formula (Ia).

In general formula (Ia):
Rf represents a fluorine atom or an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom.
R ₁ represents an alkyl group.
R ₂ represents a hydrogen atom or an alkyl group.

  (11) A resin having a repeating unit represented by the following general formula (II) and a repeating unit represented by the following general formula (III).

In general formulas (II) and (III):
Rf represents a fluorine atom or an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom.
R ₃ represents an alkyl group, a cycloalkyl group, an alkenyl group or a cycloalkenyl group.
R ₄ represents an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, a trialkylsilyl group, or a group having a cyclic siloxane structure.
L ₆ represents a single bond or a divalent linking group.
0 <m <100.
0 <n <100.

  (12) A pattern forming method comprising a step of forming a resist film with the positive resist composition according to any one of (1) to (8), exposing and developing the resist film.

  The preferred embodiments of the present invention will be further described below.

  (13) The positive resist composition as described in any one of (1) to (8), wherein the resin (C) is stable to an acid and insoluble in an alkaline developer.

  (14) The total amount of repeating units having an alkali-soluble group in the resin (C) or a group whose solubility in a developer is increased by the action of an acid or alkali is 20 with respect to all the repeating units constituting the resin (C). The positive resist composition as described in any one of (1) to (8), wherein the positive resist composition has a mol% or less.

  (15) The positive resist according to any one of (1) to (8), (13), and (14), wherein a receding contact angle with respect to a water film upon film formation is 70 ° or more. Composition.

  (16) The positive resist according to any one of (1) to (8) and (13) to (15), wherein the weight average molecular weight of the resin (C) is 1,000 to 50,000 Composition.

  (17) The addition amount of the resin (C) is 0.1 to 5% by mass with respect to the total solid content in the positive resist composition (1) to (8) and (13) )-(16).

  (18) The positive resist composition as described in any one of (1) to (8) and (13) to (17), further comprising (E) a basic compound.

  (19) The positive resist composition as described in any one of (1) to (8) and (13) to (18), further comprising (F) a fluorine-based and / or silicon-based surfactant. object.

  (20) The solvent (D) is a mixed solvent of two or more types containing propylene glycol monomethyl ether acetate, (1) to (8) and any one of (13) to (19) A positive resist composition.

  (21) Any of (1) to (8) and (13) to (20), wherein the resin (A) has a repeating unit having an alicyclic hydrocarbon group substituted with a hydroxyl group or a cyano group A positive resist composition as described above.

  (22) The resin (A) has at least a (meth) acrylate repeating unit having a lactone ring, a (meth) acrylate repeating unit having an organic group substituted with at least one of a hydroxyl group and a cyano group, and an acid. Any one of (1) to (8) and (13) to (21), which is a copolymer having three types of repeating units of a (meth) acrylate-based repeating unit having a degradable group A positive resist composition as described above.

  (23) The weight average molecular weight of the resin (A) is 5,000 to 15,000, and the degree of dispersion of the resin (A) is 1.2 to 3.0. (8) The positive resist composition according to any one of (13) to (22).

  (24) The compound (B) is a compound that generates an aliphatic sulfonic acid having a fluorine atom or a benzenesulfonic acid having a fluorine atom upon irradiation with an actinic ray or radiation (1) to (8) And the positive resist composition according to any one of (13) to (23).

  (25) The positive resist composition as described in any one of (1) to (8) and (13) to (24), wherein the compound (B) has a triphenylsulfonium structure.

  (26) The positive resist composition as described in (25), wherein the compound (B) is a triphenylsulfonium salt compound having an alkyl group or a cycloalkyl group not substituted with fluorine at the cation moiety.

  (27) The total solid content in the positive resist composition is 1.0 to 6.0% by mass, and any one of (1) to (8) and (13) to (26) The positive resist composition as described.

  (28) The positive resist composition as described in any one of (1) to (8) and (13) to (27), wherein the resin (A) does not have a fluorine atom and a silicon atom.

  (29) The pattern forming method as described in (12), wherein the exposure is performed with light having a wavelength of 1 nm to 200 nm.

  (30) The pattern forming method as described in (12) or (29), which includes an immersion exposure step.

  According to the present invention, it is possible to provide a positive resist composition in which the resist pattern collapses due to the placement between exposure and PEB and the profile deterioration is improved. Also, a positive resist composition that has good followability to immersion liquid during immersion exposure and is suitable for immersion exposure, a resin used in the positive resist composition, and used for synthesis of the resin And a pattern forming method using the positive resist 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).

(A) Resin having a monocyclic or polycyclic alicyclic hydrocarbon structure and having increased solubility in an alkaline developer by the action of an acid The resin used in the positive resist composition of the present invention is monocyclic or polycyclic This resin has an alicyclic hydrocarbon structure and has increased solubility in an alkaline developer by the action of an acid, and decomposes into the main chain or side chain of the resin, or both the main chain and the side chain by the action of an acid. And a resin having a group that generates an alkali-soluble group (hereinafter also referred to as “acid-decomposable group”) (also referred to as “acid-decomposable resin”, “acid-decomposable resin (A)”, or “resin (A)”) It is.
Alkali-soluble groups include phenolic hydroxyl groups, carboxylic acid groups, fluorinated alcohol groups, sulfonic acid groups, sulfonamido groups, sulfonylimide groups, (alkylsulfonyl) (alkylcarbonyl) methylene groups, (alkylsulfonyl) (alkylcarbonyl) Imido group, bis (alkylcarbonyl) methylene group, bis (alkylcarbonyl) imide group, bis (alkylsulfonyl) methylene group, bis (alkylsulfonyl) imide group, tris (alkylcarbonyl) methylene group, tris (alkylsulfonyl) methylene group A group having
Preferred alkali-soluble groups include carboxylic acid groups, fluorinated alcohol groups (preferably hexafluoroisopropanol), and sulfonic acid groups.
A preferred group as an acid-decomposable group (acid-decomposable group) is a group obtained by substituting the hydrogen atom of these alkali-soluble groups with a group capable of leaving with an acid.
Examples of the group capable of leaving with an acid include -C (R ₃₆ ) (R ₃₇ ) (R ₃₈ ), -C (R ₃₆ ) (R
₃₇ ) (OR ₃₉ ), -C (R ₀₁ ) (R ₀₂ ) (OR ₃₉ ) and the like.
In the formula, R _{36 to} R ₃₉ each independently represents an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or an alkenyl group. R ₃₆ and R ₃₇ may be bonded to each other to form a ring.
R _{01 and} R ₀₂ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group or an alkenyl group.
The acid-decomposable group is preferably a cumyl ester group, an enol ester group, an acetal ester group, a tertiary alkyl ester group or the like. More preferably, it is a tertiary alkyl ester group.

  The positive resist composition of the present invention, which has a monocyclic or polycyclic alicyclic hydrocarbon structure and contains a resin whose solubility in an alkaline developer is increased by the action of an acid, can be obtained when irradiated with ArF excimer laser light. It can be preferably used.

  As a resin that has a monocyclic or polycyclic alicyclic hydrocarbon structure, decomposes by the action of an acid, and increases its solubility in an alkaline developer (hereinafter also referred to as “alicyclic hydrocarbon-based acid-decomposable resin”) , At least selected from the group consisting of repeating units having a partial structure containing an alicyclic hydrocarbon represented by the following general formula (pI) to general formula (pV) and repeating units represented by the following general formula (II-AB) It is preferable that it is resin containing 1 type.

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 the 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 that decomposes by the action of an acid, —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.

In the general formulas (pI) to (pV), the alkyl group in R _{12 to} R ₂₅ represents a linear or branched alkyl group having 1 to 4 carbon atoms.

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.

  As further substituents of these alkyl groups and cycloalkyl groups, alkyl groups (1 to 4 carbon atoms), halogen atoms, hydroxyl groups, alkoxy groups (1 to 4 carbon atoms), carboxyl groups, alkoxycarbonyl groups (carbon numbers) 2-6). 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, a hydrogen atom of a sulfonic acid group is substituted with a structure represented by general formulas (pI) to (pV).

  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.

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

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

  Hereinafter, although the specific example of the repeating unit shown by general formula (pA) is shown, this invention is not limited to this.

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 in R ₁₁ ′ and R ₁₂ ′ include a linear or branched alkyl group 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 skeleton of the alicyclic hydrocarbon formed include those similar to the alicyclic hydrocarbon groups of R _{12 to} R _{25 in} the general formulas (pI) to (pVI).

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 alicyclic hydrocarbon-based acid-decomposable resin according to the present invention, the group decomposed by the action of an acid has a partial structure containing the alicyclic hydrocarbon represented by the general formula (pI) to the general formula (pV). It can be contained in at least one kind of repeating unit among the repeating unit having, the repeating unit represented by formula (II-AB), and the repeating unit of the copolymerization component described later.

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 alicyclic hydrocarbon-based acid-decomposable resin of the present invention preferably has a lactone group. As the lactone group, any group can be used as long as it contains a lactone structure, but preferably a group containing a 5- to 7-membered ring lactone structure, and a bicyclo structure in the 5- to 7-membered ring lactone structure, Those in which other ring structures are condensed to form a spiro structure are preferred. It is more preferable to have a repeating unit having a group having a lactone structure represented by any of the following general formulas (LC1-1) to (LC1-16). Further, a group having a lactone structure may be directly bonded to the main chain. Preferred lactone structures are groups represented by general formulas (LC1-1), (LC1-4), (LC1-5), (LC1-6), (LC1-13), (LC1-14), By using a specific lactone structure, line 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 (LC1-16), 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 a single bond, an alkylene group, a divalent linking group having a monocyclic or polycyclic alicyclic hydrocarbon structure, an ether group, an ester group, a carbonyl group, a carboxyl group, or a divalent group obtained by combining these. Represents. A linking group represented by a single bond or —Ab ₁ —CO ₂ — is preferable. Ab ₁ is a linear, branched alkylene group, monocyclic or polycyclic cycloalkylene group, preferably a methylene group, an ethylene group, a cyclohexylene group, an adamantylene group or a norbornylene 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 alicyclic hydrocarbon-based acid-decomposable resin of the present invention has a repeating unit containing an organic group having a polar group, particularly a repeating unit having an alicyclic hydrocarbon structure substituted with a polar group. preferable. This improves the substrate adhesion and developer compatibility. The alicyclic hydrocarbon structure of the alicyclic hydrocarbon structure substituted with a polar group is preferably an adamantyl group, a diamantyl group, or a norbornane group. The polar group is preferably a hydroxyl group or a cyano group.
As the alicyclic hydrocarbon structure substituted with a polar group, partial structures represented by the following general formulas (VIIa) to (VIId) are preferable.

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 rest are hydrogen atoms.
In general formula (VIIa), it is more preferable that two members out 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 the above. has a group represented by the general formula (VII) (e.g., represents a group R ₅ in -COOR ₅ is a represented by the general formula (VIIa) ~ (VIId)) , or the following general formula (AIIa) ~ ( A repeating unit represented by AId) can be mentioned.

In general formulas (AIIa) to (AIId),
R _1c represents a hydrogen atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group.
R _2c to R _4c have the same meanings as R _2c to R _4c in formulas (VIIa) ~ (VIIc).

  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 alicyclic hydrocarbon-based acid-decomposable resin of the present invention may have a repeating unit represented by the following general formula (VIII).

In the above 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 alicyclic hydrocarbon-based acid-decomposable resin 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. Either a repeating unit that is bonded, or a polymerization initiator or chain transfer agent having an alkali-soluble group is introduced at the end of the polymer chain at the time of polymerization, and the linking group is a monocyclic or polycyclic hydrocarbon. You may have a structure. Particularly preferred are repeating units of acrylic acid or methacrylic acid.

  The alicyclic hydrocarbon-based acid-decomposable resin 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.
Rx represents a hydrogen atom or an organic group (preferably an acid-decomposable protecting 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 Rx include an acid-decomposable protective 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 a group represented by the general formula (F1) is preferably a repeating unit represented by the following general formula (F2).

In general formula (F2),
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 represents a 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 a group represented by the general formula (F1) are shown below, but the present invention is not limited thereto.

  The alicyclic hydrocarbon-based acid-decomposable resin of the present invention may further contain a repeating unit having an alicyclic hydrocarbon structure and not exhibiting 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, and cyclohexyl (meth) acrylate.

  In addition to the above repeating structural units, the alicyclic hydrocarbon-based acid-decomposable resin of the present invention has a dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and resolving power that is a general necessary characteristic of a resist. Various repeating structural units can be contained for the purpose of adjusting heat resistance, sensitivity, and the like.

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

Thereby, performance required for the alicyclic hydrocarbon-based acid-decomposable resin, in particular,
(1) Solubility in coating solvent,
(2) Film formability (glass transition temperature),
(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 alicyclic hydrocarbon-based acid-decomposable resins, the molar ratio of each repeating structural unit is the resist's dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and resolution that is a general required performance of resists. In order to adjust heat resistance, sensitivity, etc., it is set appropriately.

Preferred embodiments of the alicyclic hydrocarbon-based acid-decomposable resin of the present invention include the following.
(1) What contains the repeating unit which has a partial structure containing the alicyclic hydrocarbon represented by said general formula (pI)-(pV) (side chain type).
Preferably those containing (meth) acrylate repeating units having a structure of (pI) to (pV).
(2) One containing a repeating unit represented by the general formula (II-AB) (main chain type).
However, in (2), for example, the following can be further mentioned.
(3) A repeating unit represented by the general formula (II-AB), a maleic anhydride derivative and a (meth) acrylate structure (hybrid type).

  In the alicyclic hydrocarbon-based acid-decomposable resin, 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 in all repeating structural units. -40 mol%.

  In the acid-decomposable resin, 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. is there.

  In the alicyclic hydrocarbon-based acid-decomposable resin, 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 70 in all the repeating structural units. The mol% is preferable, more preferably 20 to 50 mol%, still more preferably 25 to 40 mol%.

  In the alicyclic hydrocarbon-based acid-decomposable resin, the content of the repeating unit represented by the general formula (II-AB) is preferably 10 to 60 mol%, more preferably 15 to 55 mol% in all repeating structural units. More preferably, it is 20-50 mol%.

In the acid-decomposable resin, the content of the repeating unit having a lactone ring is preferably 10 to 70 mol%, more preferably 20 to 60 mol%, still more preferably 25 to 40 mol% in all repeating structural units.
In the acid-decomposable resin, the content of the repeating unit having an organic group having a polar group is preferably 1 to 40 mol%, more preferably 5 to 30 mol%, still more preferably 5 to 20 mol in all repeating structural units. %.

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

  When the positive resist 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 alicyclic hydrocarbon-based acid-decomposable resin used in the present invention is preferably one in which all of the repeating units are composed of (meth) acrylate-based repeating units. In this case, all of the repeating units may be methacrylate repeating units, all of the repeating units may be acrylate repeating units, and all of the repeating units may be any mixture of methacrylate repeating units / acrylate repeating units, It is preferable that the acrylate repeating unit is 50 mol% or less of the entire repeating unit.

  The alicyclic hydrocarbon-based acid-decomposable resin includes at least a (meth) acrylate-based repeating unit having a lactone ring, a (meth) acrylate-based repeating unit having an organic group substituted with at least one of a hydroxyl group and a cyano group, and A copolymer having three types of repeating units of a (meth) acrylate-based repeating unit having an acid-decomposable group is preferable.

  Preferably, 20 to 50 mol% of repeating units having a partial structure containing an alicyclic hydrocarbon represented by general formulas (pI) to (pV), 20 to 50 mol% of repeating units having a lactone structure, substituted with a polar group It is a ternary copolymer containing 5 to 30% of repeating units having an alicyclic hydrocarbon structure, or a quaternary copolymer containing 0 to 20% of other repeating units.

  Particularly preferable resins include 20 to 50 mol% of repeating units having an acid-decomposable group represented by the following general formulas (ARA-1) to (ARA-5), and the following general formulas (ARL-1) to (ARL- 6) 50 to 50 mol% of a repeating unit having a lactone group represented by formula (6), and a repeating unit having an alicyclic hydrocarbon structure substituted with a polar group represented by the following general formulas (ARH-1) to (ARH-3) A ternary copolymer containing 5 to 30 mol% of units, or a carboxyl group, or a repeating unit having a structure represented by the general formula (F1), having an alicyclic hydrocarbon structure and not exhibiting acid decomposability It is a quaternary copolymer containing 5 to 20 mol% of repeating units.

(In the formula, Rxy ₁ represents a hydrogen atom or a methyl group, and Rxa ₁ and Rxb ₁ represent a methyl group or an ethyl group.)

  The alicyclic hydrocarbon-based acid-decomposable resin used in the present invention can be synthesized according to a conventional method (for example, radical polymerization). For example, as a general synthesis method, 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 that used in the resist composition of the present invention. Thereby, generation | occurrence | production of the particle at the time of a preservation | save 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.
For purification, the same method as that for the resin (C) described later can be used. The liquid-liquid extraction method for removing residual monomers and oligomer components by combining water washing and an appropriate solvent, only those having a specific molecular weight or less. A purification method in a solution state such as ultrafiltration to extract and remove the residual monomer by coagulating the resin in the poor solvent by dropping the resin solution into the poor solvent, A usual method such as a purification method in a solid state, such as washing the filtered resin slurry with a poor solvent, can be applied.

The weight average molecular weight of the resin according to the present invention is preferably 1,000 to 200,000, more preferably 3,000 to 20,000, and most preferably 5,000 to 15 in terms of polystyrene by GPC method. , 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 degree of dispersion (molecular weight distribution) is usually 1 to 5, preferably 1 to 3, more preferably 1.2 to 3.0, particularly preferably 1.2 to 2.0. . The smaller the degree of dispersion, the better the resolution and the resist shape, the smoother the side wall of the resist pattern, and the better the roughness.

In the positive resist composition of the present invention, the blending amount of all the resins according to the present invention in the entire composition is preferably 50 to 99.9% by mass, more preferably 60 to 99.0% by mass in the total solid content. %.
In the present invention, the resins may be used alone or in combination.

  The alicyclic hydrocarbon-based acid-decomposable resin of the present invention preferably contains no fluorine atom or silicon atom from the viewpoint of compatibility with the resin (C).

(B) Compound that generates acid upon irradiation with actinic ray or radiation The positive resist composition of the present invention is a compound that generates acid upon irradiation with actinic ray or radiation ("photoacid generator" or "component (B)") (Also called).
Examples of such photoacid generators include photoinitiators for photocationic polymerization, photoinitiators for photoradical polymerization, photodecolorants for dyes, photochromic agents, actinic rays used in microresists, etc. 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 decompose upon irradiation with actinic rays or radiation to generate an acid, compounds represented by the following general formulas (ZI), (ZII), and (ZIII) can be exemplified.

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

  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 each independently represents 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 Rc _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.

The carbon number of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ is generally 1-30, preferably 1-20.
Two of R _{201 to} R ₂₀₃ may be bonded to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond, or a carbonyl group. The two of the group formed by bonding of the R ₂₀₁ to R _203, there can be mentioned an alkylene group (e.g., butylene, pentylene).
Specific examples of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ include corresponding groups in the compounds (ZI-1), (ZI-2) and (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 preferable (ZI) components include compounds (ZI-1), (ZI-2), and (ZI-3) described below.

The compound (ZI-1) is at least one of the aryl groups R ₂₀₁ to R ₂₀₃ in formula (ZI), arylsulfonium compound, i.e., a compound having arylsulfonium as a cation.
In the arylsulfonium compound, all of R _{201 to} R ₂₀₃ may be an aryl group, or a part of R _{201 to} R ₂₀₃ may be an aryl group, and the rest may be an alkyl group or a cycloalkyl group.
Examples of the arylsulfonium compound include triarylsulfonium compounds, diarylalkylsulfonium compounds, aryldialkylsulfonium compounds, diarylcycloalkylsulfonium compounds, and aryldicycloalkylsulfonium compounds.
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, 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 linear or branched alkyl groups having 1 to 12 carbon atoms, cycloalkyl groups having 3 to 12 carbon atoms, and linear, branched or cyclic alkoxy groups having 1 to 12 carbon atoms, and particularly preferable. Is an alkyl group having 1 to 4 carbon atoms and an alkoxy group having 1 to 4 carbon atoms. The substituent may be substituted with any one of the three R _{201 to} R ₂₀₃ , or may be substituted with all three. When R _{201 to} R ₂₀₃ are an aryl group, the substituent is preferably substituted at the p-position of the aryl group.

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 or 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.
Linear as R ₂₀₁ to R _203, 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,
Preferable examples include an alkoxy group having 1 to 5 carbon atoms (methoxy group, ethoxy group, propoxy group, butoxy group, pentoxy group).
R _{201 to} R ₂₀₃ may be further substituted with a halogen atom, an alkoxy group (for example, 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 _7c, and R _x and R _y may be bonded to each other to form a ring structure, the ring structure may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond May be included. Examples of the group formed by combining any two or more of R _{1c to} R _7c and R _x and R _y include a butylene group and a pentylene group.
X ⁻ represents a non-nucleophilic anion, and examples thereof include the same non-nucleophilic anion as X ^{− in} formula (ZI).

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. Or a linear or branched alkyl group (for example, a methyl group, an ethyl group, a linear or branched propyl group, a linear or branched butyl group, or a 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 or branched alkyl group, a cycloalkyl group, or a linear, branched or cyclic alkoxy group, and more preferably the sum of the carbon number of R _{1c to} R _5c is 2 ~ 15. Thereby, solvent solubility improves more and generation | occurrence | production of a particle is suppressed at the time of a preservation | save.

_Examples of the alkyl group as R _x and R _y include the same alkyl groups as R _{1c to} R _7c . The alkyl group as R _x and R _y is preferably a linear or branched 2-oxoalkyl group or an alkoxycarbonylmethyl group.
The cycloalkyl group as R _x and R _y may be the same as the cycloalkyl group as R _1c to R _7c. The cycloalkyl group as R _x and R _y is preferably a cyclic 2-oxoalkyl group.
Examples of the linear, branched, or cyclic 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 aryl group, an alkyl group or a cycloalkyl group.
Phenyl group and a naphthyl group are preferred as the aryl group of R ₂₀₄ to R _207, more preferably a phenyl group.
The alkyl group as R ₂₀₄ to R ₂₀₇ 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).
R ₂₀₄ to R ₂₀₇ may have a substituent. The R ₂₀₄ to R ₂₀₇ are substituents which may have, for example, an alkyl group (for example, 1 to 15 carbon atoms), a cycloalkyl group (for example, 3 to 15 carbon atoms), an aryl group (e.g., 6 carbon atoms 15), alkoxy groups (for example, having 1 to 15 carbon atoms), halogen atoms, hydroxyl groups, phenylthio groups and the like.
X ⁻ represents a non-nucleophilic anion, and examples thereof include the same non-nucleophilic anion as X ^{− in} formula (ZI).

  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 represents an aryl group.
R ₂₀₆ represents an alkyl group or an aryl group.
_R207 and _R208 each independently represents an alkyl group, an aryl group, or an electron-withdrawing group. R ₂₀₇ is preferably an aryl group.
R ₂₀₈ is preferably an electron-withdrawing group, more preferably a cyano group or a fluoroalkyl group.
A represents an alkylene group, an alkenylene group or an arylene group.

As compounds that generate an acid upon irradiation with actinic rays or radiation, the compounds represented by the general formulas (ZI) to (ZI)
Compounds represented by II) are preferred.

  The compound (B) is preferably a compound that generates an aliphatic sulfonic acid having a fluorine atom or a benzenesulfonic acid having a fluorine atom upon irradiation with actinic rays or radiation.

  The compound (B) preferably has a triphenylsulfonium structure.

  The compound (B) is preferably a triphenylsulfonium salt compound having an alkyl group or a cycloalkyl group not substituted with fluorine in the cation moiety.

  Among the compounds that generate an acid upon irradiation with actinic rays or radiation, 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 is preferably 0.1 to 20% by mass, more preferably 0.5 to 10% by mass, still more preferably 1 to 7% by mass, based on the total solid content of the positive resist composition. It is.

(C) Resin having at least one of fluorine atom and silicon atom The positive resist composition of the present invention contains a resin (C) having at least one of fluorine atom and silicon atom.
The fluorine atom or silicon atom in the resin (C) may be contained in the main chain of the resin or may be substituted with a side chain.

The resin (C) is preferably a resin having an alkyl group having a fluorine atom, a cycloalkyl group having a fluorine atom, or an aryl group having a fluorine atom as a partial structure having a fluorine atom.
The alkyl group having a fluorine atom (preferably having 1 to 10 carbon atoms, more preferably 1 to 4 carbon atoms) is a linear or branched alkyl group in which at least one hydrogen atom is substituted with a fluorine atom, It may have a substituent.
The cycloalkyl group having a fluorine atom is a monocyclic or polycyclic cycloalkyl group in which at least one hydrogen atom is substituted with a fluorine atom, and may further have another substituent.
Examples of the aryl group having a fluorine atom include those in which at least one hydrogen atom of an aryl group such as a phenyl group or a naphthyl group is substituted with a fluorine atom, and may further have another substituent.

  Specific examples of the alkyl group having a fluorine atom, the cycloalkyl group having a fluorine atom, or the aryl group having a fluorine atom are shown below, but the present invention is not limited thereto.

In general formulas (F2) to (F4),
R _{57 to} R ₆₈ each independently represents a hydrogen atom, a fluorine atom or an alkyl group. However, at least one of R _{57 to} R ₆₁ , R _{62 to} R ₆₄ and R _{65 to} R ₆₈ is a fluorine atom or an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom (preferably having a carbon number of 1 ~ 4). R _{57 to} R ₆₁ and R _{65 to} R ₆₇ are preferably all fluorine atoms. R ₆₂ , R ₆₃ and R ₆₈ are preferably an alkyl group (preferably having 1 to 4 carbon atoms) in which at least one hydrogen atom is substituted with a fluorine atom, and preferably a perfluoroalkyl group having 1 to 4 carbon atoms. Further preferred. R ₆₂ and R ₆₃ may be connected to each other to form a ring.

Specific examples of the group represented by the general formula (F2) include a p-fluorophenyl group, a pentafluorophenyl group, and a 3,5-di (trifluoromethyl) phenyl group.
Specific examples of the group represented by the general formula (F3) include trifluoroethyl group, pentafluoropropyl group, pentafluoroethyl group, heptafluorobutyl group, hexafluoroisopropyl group, heptafluoroisopropyl group, hexafluoro (2 -Methyl) isopropyl group, nonafluorobutyl group, octafluoroisobutyl group, nonafluorohexyl group, nonafluoro-t-butyl group, perfluoroisopentyl group, perfluorooctyl group, perfluoro (trimethyl) hexyl group, 2,2 1,3,3-tetrafluorocyclobutyl group, perfluorocyclohexyl group and the like. Hexafluoroisopropyl group, heptafluoroisopropyl group, hexafluoro (2-methyl) isopropyl group, octafluoroisobutyl group, nonafluoro-t-butyl group and perfluoroisopentyl group are preferable, and hexafluoroisopropyl group and heptafluoroisopropyl group are preferable. Further preferred.
Specific examples of the group represented by the general formula (F4) include, for example, —C (CF ₃ ) ₂ OH, —C (C ₂ F ₅ ) ₂ OH, —C (CF ₃ ) (CH ₃ ) OH, -CH (CF ₃₎ OH and the like, -C (CF _{3) 2} OH is preferred.

The resin (C) is preferably a resin having an alkylsilyl structure (preferably a trialkylsilyl group) or a cyclic siloxane structure as a partial structure having a silicon atom.
Specific examples of the alkylsilyl structure or the cyclic siloxane structure include groups represented by the following general formulas (CS-1) to (CS-3).

In general formulas (CS-1) to (CS-3),
R _{12 to} R ₂₆ each independently represents a linear or branched alkyl group (preferably having 1 to 20 carbon atoms) or a cycloalkyl group (preferably having 3 to 20 carbon atoms).
L < ₃ > -L < ₅ > represents a single bond or a bivalent coupling group. As the divalent linking group, an alkylene group, a phenyl group, an ether group, a thioether group, a carbonyl group, an ester group, an amide group, a urethane group, or a urea group is used alone or in combination of two or more groups. A combination is mentioned.

  Examples of the resin (C) include resins having at least one selected from the group of repeating units represented by the following general formulas (CI) to (CV).

In the general formulas (CI) to (CV),
R _{1 to} R ₃ each independently represents a hydrogen atom, a fluorine atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or a linear or branched fluorinated alkyl group having 1 to 4 carbon atoms. Represents a group.
W _{1 to} W ₂ represent an organic group having at least one of a fluorine atom and a silicon atom.
R _{4 to} R ₇ are each independently a hydrogen atom, a fluorine atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or a linear or branched fluorinated alkyl group having 1 to 4 carbon atoms. Represents a group. However, at least one of R _{4 to} R ₇ represents a fluorine atom. R ₄ and R ₅ or R ₆ and R ₇ may form a ring.
R ₈ represents a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms.
R ₉ represents a linear or branched alkyl group having 1 to 4 carbon atoms, or a linear or branched fluorinated alkyl group having 1 to 4 carbon atoms.
L < ₁ > -L < ₂ > represents a single bond or a bivalent coupling group, and is the same as said L < ₃ > -L < ₅ >.
Q represents a monocyclic or polycyclic cyclic aliphatic group. That is, it represents an atomic group that contains two bonded carbon atoms (C—C) and forms an alicyclic structure.
R ₃₀ and R ₃₁ each independently represents a hydrogen atom or a fluorine atom.
R ₃₂ and R ₃₃ each independently represents an alkyl group, a cycloalkyl group, a fluorinated alkyl group or a fluorinated cycloalkyl group.
However, the repeating unit represented by formula (CV) has at least one fluorine atom in at least one of R ₃₀ , R ₃₁ , R ₃₂ and R ₃₃ .

  The resin (C) preferably has a repeating unit represented by the general formula (CI), and further has a repeating unit represented by the following general formulas (C-Ia) to (C-Id). preferable.

In the general formulas (C-Ia) to (C-Id),
R ₁₀ and R ₁₁ represent a hydrogen atom, a fluorine atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or a linear or branched fluorinated alkyl group having 1 to 4 carbon atoms.
W _{3 to} W ₆ represent an organic group having at least one of a fluorine atom and a silicon atom.

When W _{1 to} W ₆ are organic groups having a fluorine atom, they are fluorinated, straight chain, branched alkyl group or cycloalkyl group having 1 to 20 carbon atoms, or fluorinated having 1 to 20 carbon atoms. It is preferably a linear, branched, or cyclic alkyl ether group.

Examples of the fluorinated alkyl group for W _{1 to} W ₆ include trifluoroethyl group, pentafluoropropyl group, hexafluoroisopropyl group, hexafluoro (2-methyl) isopropyl group, heptafluorobutyl group, heptafluoroisopropyl group, octafluoro Examples thereof include an isobutyl group, a nonafluorohexyl group, a nonafluoro-t-butyl group, a perfluoroisopentyl group, a perfluorooctyl group, and a perfluoro (trimethyl) hexyl group.

When W _{1 to} W ₆ are an organic group having a silicon atom, an alkylsilyl structure or a cyclic siloxane structure is preferable. Specific examples include groups represented by the general formulas (CS-1) to (CS-3).

Specific examples of the repeating unit represented by the general formula (CI) are shown below. X represents a hydrogen atom, —CH ₃ , —F, or —CF ₃ .

The resin (C) is preferably any resin selected from the following (C-1) to (C-6).
(C-1) A resin having a repeating unit (a) having a fluoroalkyl group (preferably having 1 to 4 carbon atoms), more preferably a resin having only a repeating unit (a).
(C-2) A resin having a repeating unit (b) having a trialkylsilyl group or a cyclic siloxane structure, more preferably a resin having only a repeating unit (b).
(C-3) a repeating unit (a) having a fluoroalkyl group (preferably having 1 to 4 carbon atoms), a branched alkyl group (preferably having 4 to 20 carbon atoms), a cycloalkyl group (preferably having 4 carbon atoms) To 20), a repeating unit (c) having a branched alkenyl group (preferably having 4 to 20 carbon atoms), a cycloalkenyl group (preferably having 4 to 20 carbon atoms) or an aryl group (preferably having 4 to 20 carbon atoms). More preferably, a copolymer resin of the repeating unit (a) and the repeating unit (c).
(C-4) a repeating unit (b) having a trialkylsilyl group or a cyclic siloxane structure, a branched alkyl group (preferably having 4 to 20 carbon atoms), a cycloalkyl group (preferably having 4 to 20 carbon atoms), Resin having a repeating unit (c) having a branched alkenyl group (preferably having 4 to 20 carbon atoms), a cycloalkenyl group (preferably having 4 to 20 carbon atoms) or an aryl group (preferably having 4 to 20 carbon atoms) More preferably, a copolymer resin of the repeating unit (b) and the repeating unit (c).
(C-5) A resin having a repeating unit (a) having a fluoroalkyl group (preferably having 1 to 4 carbon atoms) and a repeating unit (b) having a trialkylsilyl group or a cyclic siloxane structure, more preferably a repeating unit Copolymer resin of unit (a) and repeating unit (b).
(C-6) a repeating unit (a) having a fluoroalkyl group (preferably having 1 to 4 carbon atoms), a repeating unit (b) having a trialkylsilyl group or a cyclic siloxane structure, and a branched alkyl group (preferably Is a C4-20), cycloalkyl group (preferably C4-20), branched alkenyl group (preferably C4-20), cycloalkenyl group (preferably C4-20) or aryl. A resin having a repeating unit (c) having a group (preferably having 4 to 20 carbon atoms), more preferably a repeating unit (a), a repeating unit (
a copolymer resin of b) and the repeating unit (c).
Repeating unit (c) having a branched alkyl group, cycloalkyl group, branched alkenyl group, cycloalkenyl group, or aryl group in resins (C-3), (C-4), and (C-6) In consideration of hydrophilicity / hydrophobicity, interaction, etc., appropriate functional groups can be introduced, but from the viewpoint of immersion liquid follow-up and receding contact angle, functional groups that do not have polar groups Is preferred.
In the resins (C-3), (C-4), and (C-6), the repeating unit (a) having a fluoroalkyl group and / or the repeating unit (b) having a trialkylsilyl group or a cyclic siloxane structure is It is preferable that it is 20-99 mol%.

  The resin (C) is preferably a resin having a repeating unit represented by the following general formula (Ia).

In general formula (Ia):
Rf represents a fluorine atom or an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom.
R ₁ represents an alkyl group.
R ₂ represents a hydrogen atom or an alkyl group.

In general formula (Ia), the alkyl group in which at least one hydrogen atom of Rf is substituted with a fluorine atom preferably has 1 to 3 carbon atoms, and more preferably a trifluoromethyl group.
The alkyl group represented by R ₁ is preferably a linear or branched alkyl group having 3 to 10 carbon atoms, and more preferably a branched alkyl group having 3 to 10 carbon atoms.
R ₂ is preferably a linear or branched alkyl group having 1 to 10 carbon atoms, and more preferably a linear or branched alkyl group having 3 to 10 carbon atoms.

  Hereinafter, although the specific example of the repeating unit represented by general formula (Ia) is given, this invention is not limited to this.

  The repeating unit represented by the general formula (Ia) can be formed by polymerizing a compound represented by the following general formula (I).

In general formula (I),
Rf represents a fluorine atom or an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom.
R ₁ represents an alkyl group.
R ₂ represents a hydrogen atom or an alkyl group.

In the general formula (I), Rf, R ₁ and R ₂ are in the general formula (Ia), Rf, R ₁ and R ₂ synonymous.
The compound represented by the general formula (I) is a novel compound.
As the compound represented by the general formula (I), a commercially available product may be used, or a synthesized product may be used. In the case of synthesis, 2-trifluoromethylmethacrylic acid can be obtained by acidification and then esterification.

The resin (C) having a repeating unit represented by the general formula (Ia) is further represented by the following general formula (I
It is preferable to have a repeating unit represented by II).

In general formula (III):
R ₄ represents an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, a trialkylsilyl group, or a group having a cyclic siloxane structure.
L ₆ represents a single bond or a divalent linking group.

In general formula (III), the alkyl group represented by R ₄ is preferably a linear or branched alkyl group having 3 to 20 carbon atoms.
The cycloalkyl group is preferably a cycloalkyl group having 3 to 20 carbon atoms.
The alkenyl group is preferably an alkenyl group having 3 to 20 carbon atoms.
The cycloalkenyl group is preferably a cycloalkenyl group having 3 to 20 carbon atoms.
The trialkylsilyl group is preferably a trialkylsilyl group having 3 to 20 carbon atoms.
The group having a cyclic siloxane structure is preferably a group having a cyclic siloxane structure having 3 to 20 carbon atoms.
The divalent linking group of L ₆ is preferably an alkylene group (preferably having 1 to 5 carbon atoms) or an oxy group.

  Hereinafter, although the specific example of resin (C) which has a repeating unit represented by general formula (Ia) is given, this invention is not limited to this.

  The resin (C) is preferably a resin having a repeating unit represented by the following general formula (II) and a repeating unit represented by the following general formula (III).

In general formulas (II) and (III):
Rf represents a fluorine atom or an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom.
R ₃ represents an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, or a group formed by combining two or more thereof.
R ₄ represents an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, a trialkylsilyl group, a group having a cyclic siloxane structure, or a group formed by combining two or more thereof.
The alkyl group, cycloalkyl group, alkenyl group, cycloalkenyl group, and trialkylsilyl group of R ₃ and R ₄ can introduce a functional group, but have a polar group from the viewpoint of immersion liquid followability. The functional group is preferably not substituted, and more preferably unsubstituted.
L ₆ represents a single bond or a divalent linking group.
0 <m <100.
0 <n <100.

Rf in the general formula (II) is the same as Rf in the general formula (Ia).
The alkyl group represented by R ₃ is preferably a linear or branched alkyl group having 3 to 20 carbon atoms.
The cycloalkyl group is preferably a cycloalkyl group having 3 to 20 carbon atoms.
The alkenyl group is preferably an alkenyl group having 3 to 20 carbon atoms.
The cycloalkenyl group is preferably a cycloalkenyl group having 3 to 20 carbon atoms.
L ₆ is preferably a single bond, a methylene group, an ethylene group or an ether group.
m = 30 to 70 and n = 30 to 70 are preferable, and m = 40 to 60 and n = 40 to 60 are more preferable.

  Hereinafter, specific examples of the resin (C) having the repeating unit represented by the general formula (II) and the repeating unit represented by the general formula (III) will be described, but the present invention is not limited thereto. .

  Resin (C) 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, 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.

  The resin (C) is preferably solid at room temperature (25 ° C.). Furthermore, it is preferable that glass transition temperature (Tg) is 50-200 degreeC, and 80-160 degreeC is more preferable.

Being solid at 25 ° C. means that the melting point is 25 ° C. or higher.
Glass transition temperature (Tg) is determined by differential scanning calorimete.
For example, it can be measured by analyzing the value of the change in specific volume when the sample is once heated and cooled and then heated again at 5 ° C./min.

  The resin (C) is preferably stable to an acid and insoluble in an alkaline developer.

Resin (C) is decomposed by the action of (x) an alkali-soluble group, (y) an alkali (alkali developer), a group that increases the solubility in the alkali developer, and (z) an acid. From the viewpoint of the followability of the immersion liquid, it is preferable not to have a group that increases the solubility in the developer.
The total amount of repeating units having an alkali-soluble group in the resin (C) or a group whose solubility in a developer is increased by the action of an acid or an alkali is preferably 20 with respect to all repeating units constituting the resin (C). It is not more than mol%, more preferably 0 to 10 mol%, still more preferably 0 to 5 mol%.
Resin (C) does not have hydrophilic groups such as ionic bonds and (poly (oxyalkylene)) groups, unlike surfactants generally used in resists. When the resin (C) contains a hydrophilic polar group, the followability of immersion water tends to decrease, and therefore it is more preferable that the resin (C) does not have a polar group selected from a hydroxyl group, an alkylene glycol, and a sulfone group. . In addition, it is preferable not to have an ether group bonded to a carbon atom of the main chain through a linking group because hydrophilicity increases and immersion liquid followability deteriorates. On the other hand, an ether group directly bonded to a carbon atom of the main chain as shown in the general formula (III) is preferable because it may express a hydrophobic group.

  (X) Examples of alkali-soluble groups include phenolic hydroxyl groups, carboxylic acid groups, fluorinated alcohol groups, sulfonic acid groups, sulfonamido groups, sulfonylimide groups, (alkylsulfonyl) (alkylcarbonyl) methylene groups, and (alkylsulfonyl). ) (Alkylcarbonyl) imide group, bis (alkylcarbonyl) methylene group, bis (alkylcarbonyl) imide group, bis (alkylsulfonyl) methylene group, bis (alkylsulfonyl) imide group, tris (alkylcarbonyl) methylene group, tris ( And a group having an alkylsulfonyl) methylene group.

  (Y) Examples of the group that decomposes by the action of an alkali (alkaline developer) and increases the solubility in the alkali developer include a lactone group, an ester group, a sulfonamide group, an acid anhydride, and an acid imide group. Can be mentioned.

  (Z) Examples of the group that decomposes by the action of an acid and increases the solubility in a developer include the same groups as the acid-decomposable groups in the acid-decomposable resin (A).

  However, the repeating unit represented by the following general formula (pA-C) has no or very little decomposability due to the action of acid as compared with the acid-decomposable group of the resin (A), and is substantially non-acid-decomposable. Considered equivalent to gender.

In the general formula (pA-c),
Rp ₂ represents a hydrocarbon group having a tertiary carbon atom bonded to the oxygen atom in the formula.

  When the resin (C) has a silicon atom, the content of the silicon atom is preferably 2 to 50% by mass and more preferably 2 to 30% by mass with respect to the molecular weight of the resin (C). Moreover, it is preferable that the repeating unit containing a silicon atom is 10-100 mass% in resin (C), and it is more preferable that it is 20-100 mass%.

  When the resin (C) has a fluorine atom, the content of the fluorine atom is preferably 5 to 80% by mass and more preferably 10 to 80% by mass with respect to the molecular weight of the resin (C). Moreover, it is preferable that the repeating unit containing a fluorine atom is 10-100 mass% in resin (C), and it is more preferable that it is 30-100 mass%.

  The weight average molecular weight of the resin (C) in terms of standard polystyrene is preferably 1,000 to 100,000, more preferably 1,000 to 50,000, still more preferably 2,000 to 15,000, and particularly preferably. Is 3,000 to 15,000.

  The resin (C) preferably has a residual monomer amount of 0 to 10% by mass, more preferably 0 to 5% by mass, and still more preferably 0 to 1% by mass. The molecular weight distribution (Mw / Mn, also referred to as dispersity) is preferably 1 to 5, more preferably 1 to 3, and still more preferably 1 in terms of resolution, resist shape, resist pattern sidewall, roughness, and the like. It is in the range of ~ 1.5.

  The addition amount of the resin (C) in the positive resist composition is preferably 0.1 to 20% by mass, and preferably 0.1 to 10% by mass based on the total solid content of the resist composition. Is more preferable. Furthermore, it is preferable that it is 0.1-5 mass%, More preferably, it is 0.2-3.0 mass%, More preferably, it is 0.3-2.0 mass%.

  Resin (C), like acid-decomposable resin (A), naturally has few impurities such as metals, but residual monomers and oligomer components are not more than predetermined values, for example, 0.1% by mass by HPLC. It is preferable that not only the sensitivity, resolution, process stability, pattern shape and the like as a resist can be further improved, but also a resist having no change over time such as foreign matter in liquid or sensitivity can be obtained.

  As the resin (C), various commercially available products can be used, or they 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 that used in the resist composition of the present invention. Thereby, generation | occurrence | production of the particle at the time of a preservation | save 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 initiators include azobisisobutyronitrile, azobisdimethylvaleronitrile, dimethyl 2,2′-azobis (2-methylpropionate) and the like. A chain transfer agent can also be used as needed. The concentration of the reaction is usually 5 to 50% by mass, preferably 20 to 50% by mass, and more preferably 30 to 50% by mass. The reaction temperature is usually 10 ° C to 150 ° C, preferably 30 ° C to 120 ° C, more preferably 60-100 ° C.

  After completion of the reaction, the mixture is allowed to cool to room temperature and purified. Purification can be accomplished by a liquid-liquid extraction method that removes residual monomers and oligomer components by combining water and an appropriate solvent, and a purification method in a solution state such as ultrafiltration that extracts and removes only those having a specific molecular weight or less. , Reprecipitation method that removes residual monomer by coagulating resin in poor solvent by dripping resin solution into poor solvent and purification in solid state such as washing filtered resin slurry with poor solvent A normal method such as a method can be applied. For example, the resin is precipitated as a solid by contacting a solvent (poor solvent) in which the resin is hardly soluble or insoluble in a volume amount of 10 times or less, preferably 10 to 5 times that of the reaction solution.

The solvent (precipitation or reprecipitation solvent) used in the precipitation or reprecipitation operation from the polymer solution may be a poor solvent for the polymer. For example, hydrocarbon (pentane, hexane, Aliphatic hydrocarbons such as heptane and octane; Cycloaliphatic hydrocarbons such as cyclohexane and methylcyclohexane; Aromatic hydrocarbons such as benzene, toluene and xylene), halogenated hydrocarbons (methylene chloride, chloroform, carbon tetrachloride, etc.) Halogenated aliphatic hydrocarbons; halogenated aromatic hydrocarbons such as chlorobenzene and dichlorobenzene), nitro compounds (nitromethane, nitroethane, etc.), nitriles (acetonitrile, benzonitrile, etc.), ethers (diethyl ether, diisopropyl ether, dimethoxyethane) Chain A Cyclic ethers such as tetrahydrofuran and dioxane), ketones (acetone, methyl ethyl ketone, diisobutyl ketone, etc.), esters (ethyl acetate, butyl acetate, etc.), carbonates (dimethyl carbonate, diethyl carbonate, ethylene carbonate, propylene carbonate, etc.), alcohols ( (Methanol, ethanol, propanol, isopropyl alcohol, butanol, etc.), carboxylic acid (acetic acid, etc.), water, a mixed solvent containing these solvents, and the like. Among these, as a precipitation or reprecipitation solvent, a solvent containing at least an alcohol (particularly methanol or the like) or water is preferable. In such a solvent containing at least hydrocarbon, the ratio of alcohol (particularly methanol) and other solvent (for example, ester such as ethyl acetate, ethers such as tetrahydrofuran) is, for example, the former / the latter (volume ratio). ;
25 ° C.) = 10/90 to 99/1, preferably the former / the latter (volume ratio; 25 ° C.) = 30/70 to 98/2, more preferably the former / the latter (volume ratio; 25 ° C.) = 50/50 About 97/3.

  The amount of the precipitation or reprecipitation solvent used can be appropriately selected in consideration of efficiency, yield, and the like, but generally 100 to 10000 parts by mass, preferably 200 to 2000 parts by mass with respect to 100 parts by mass of the polymer solution, More preferably, it is 300-1000 mass parts.

  The nozzle diameter at the time of supplying the polymer solution to the precipitation or reprecipitation solvent (poor solvent) is preferably 4 mmφ or less (for example, 0.2 to 4 mmφ). Moreover, the supply speed (dropping speed) of the polymer solution into the poor solvent is, for example, about 0.1 to 10 m / second, preferably about 0.3 to 5 m / second, as the linear speed.

  The precipitation or reprecipitation operation is preferably performed with stirring. As a stirring blade used for stirring, for example, a desk turbine, a fan turbine (including a paddle), a curved blade turbine, an arrow blade turbine, a fiddler type, a bull margin type, an angled blade fan turbine, a propeller, a multistage type, an anchor type (or Horseshoe type), gate type, double ribbon, screw, etc. can be used. Stirring is preferably further performed for 10 minutes or more, particularly 20 minutes or more after the supply of the polymer solution. When the stirring time is short, the monomer content in the polymer particles may not be sufficiently reduced. Further, the polymer solution and the poor solvent can be mixed and stirred using a line mixer instead of the stirring blade.

  The temperature for precipitation or reprecipitation can be appropriately selected in consideration of efficiency and operability, but is usually about 0 to 50 ° C., preferably around room temperature (for example, about 20 to 35 ° C.). The precipitation or reprecipitation operation can be performed by a known method such as a batch method or a continuous method using a conventional mixing vessel such as a stirring tank.

  The precipitated or re-precipitated particulate polymer is usually subjected to conventional solid-liquid separation such as filtration and centrifugation, and dried before use. Filtration is performed using a solvent-resistant filter medium, preferably under pressure. Drying is performed at a temperature of about 30 to 100 ° C., preferably about 30 to 50 ° C. under normal pressure or reduced pressure (preferably under reduced pressure).

The resin may be once deposited and separated, and then dissolved again in a solvent, and the resin may be brought into contact with a hardly soluble or insoluble solvent.
That is, after completion of the radical polymerization reaction, a solvent in which the polymer is hardly soluble or insoluble is brought into contact, the resin is precipitated (step a), the resin is separated from the solution (step b), and dissolved again in the solvent. (Step c), and then contact the resin solution A with a solvent in which the resin is hardly soluble or insoluble in a volume amount less than 10 times that of the resin solution A (preferably 5 times or less volume). This may be a method including precipitating a resin solid (step d) and separating the precipitated resin (step e).
The solvent used in the preparation of the resin solution A can be the same solvent as the solvent that dissolves the monomer in the polymerization reaction, and may be the same as or different from the solvent used in the polymerization reaction.

(D) Solvent Examples of the solvent that can be used in preparing the positive resist composition by dissolving the above components include, for example, alkylene glycol monoalkyl ether carboxylate, alkylene glycol monoalkyl ether, alkyl lactate ester, Examples thereof include organic solvents such as alkyl alkoxypropionates, cyclic lactones having 4 to 10 carbon atoms, monoketone compounds having 4 to 10 carbon atoms, which may contain a ring, alkylene carbonate, alkyl alkoxyacetates, and alkyl pyruvates. .

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

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

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

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

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

In this invention, you may use the mixed solvent which mixed the solvent which contains a hydroxyl group in a structure, and the solvent which does not contain a hydroxyl group as an organic solvent.
Examples of the solvent containing a hydroxyl group include ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, ethyl lactate, and the like. Particularly preferred are propylene glycol monomethyl ether and ethyl lactate.
Examples of the solvent not containing a hydroxyl group include propylene glycol monomethyl ether acetate, ethyl ethoxypropionate, 2-heptanone, γ-butyrolactone, cyclohexanone, butyl acetate, N-methylpyrrolidone, N, N-dimethylacetamide, dimethyl sulfoxide and the like. Among these, propylene glycol monomethyl ether acetate, ethyl ethoxypropionate, 2-heptanone, γ-butyrolactone, cyclohexanone, and butyl acetate are particularly preferred, and propylene glycol monomethyl ether acetate, ethyl ethoxypropionate. 2-heptanone is most 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 solvent is preferably a mixed solvent of two or more containing propylene glycol monomethyl ether acetate.

(E) Basic compound The positive resist composition of the present invention preferably contains (E) a basic compound in order to reduce a change in performance over time from exposure to heating.
Preferred examples of the basic compound include compounds having structures represented by the following formulas (A) to (E).

In general formulas (A) to (E),
R ²⁰⁰ , R ²⁰¹ and R ²⁰² may be the same or different, and are a hydrogen atom, an alkyl group (preferably having 1 to 20 carbon atoms), a cycloalkyl group (preferably having 3 to 20 carbon atoms) or an aryl group (having a carbon number). 6-20), wherein R ²⁰¹ and R ²⁰² may combine with each other to form a ring.

About the said alkyl group, as an alkyl group which has a substituent, a C1-C20 aminoalkyl group, a C1-C20 hydroxyalkyl group, or a C1-C20 cyanoalkyl group is preferable.
R ²⁰³ , R ²⁰⁴ , R ²⁰⁵ and R ²⁰⁶ may be the same or different and each represents an alkyl group having 1 to 20 carbon atoms.
The alkyl groups in these general formulas (A) to (E) are more preferably unsubstituted.

  Preferred compounds include guanidine, aminopyrrolidine, pyrazole, pyrazoline, piperazine, aminomorpholine, aminoalkylmorpholine, piperidine and the like, and more preferred compounds include imidazole structure, diazabicyclo structure, onium hydroxide structure, onium carboxylate Examples thereof include a compound having a structure, a trialkylamine structure, an aniline structure or a pyridine structure, an alkylamine derivative having a hydroxyl group and / or an ether bond, and an aniline derivative having a hydroxyl group and / or an ether bond.

Examples of the compound having an imidazole structure include imidazole, 2,4,5-triphenylimidazole, and benzimidazole. 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. ] Undecar 7-ene etc. are mentioned. 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. As the compound having an onium carboxylate structure, an anion portion of the compound having an onium hydroxide structure 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 the aniline compound include 2,6-diisopropylaniline, N, N-dimethylaniline, N, N-dibutylaniline, N, N-dihexylaniline and the like. Examples of the alkylamine derivative having a hydroxyl group and / or an ether bond include ethanolamine, diethanolamine, triethanolamine, and tris (methoxyethoxyethyl) amine. Examples of aniline derivatives having a hydroxyl group and / or an ether bond include N, N-bis (hydroxyethyl) aniline.
These basic compounds are used alone or in combination of two or more.

  The usage-amount of a basic compound is 0.001-10 mass% normally on the basis of solid content of a positive resist composition, Preferably it is 0.01-5 mass%.

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

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

When the positive resist composition of the present invention contains the surfactant (F), a resist having good sensitivity and resolution and less adhesion and development defects when using an exposure light source of 250 nm or less, particularly 220 nm or less. A pattern can be given.
Examples of the fluorine-based and / or silicon-based surfactant include, for example, JP-A No. 62-36663, JP-A No. 61-226746, JP-A No. 61-226745, JP-A No. 62-170950, JP 63-34540 A, JP 7-230165 A, JP 8-62834 A, JP 9-54432 A, JP 9-5988 A, JP 2002-277862 A, US Patent Nos. 5,405,720, 5,360,692, 5,529,881, 5,296,330, 5,436,098, 5,576,143, 5,294,511, 5,824,451 Surfactant can be mentioned, The following commercially available surfactant can also be used as it is.
Examples of commercially available surfactants that can be used include EFTOP EF301 and EF303 (manufactured by Shin-Akita Kasei Co., Ltd.), Florard FC430, 431 and 4430 (manufactured by Sumitomo 3M Co., Ltd.), MegaFuck F171, F173, F176 and F189. , F113, F110, F177, F120, R08 (manufactured by Dainippon Ink & Chemicals, Inc.), Surflon S-382, SC101, 102, 103, 104, 105, 106 (manufactured by Asahi Glass Co., Ltd.), Troisol S-366 (Manufactured by Troy Chemical Co., Ltd.), GF-300, GF-150 (manufactured by Toa Gosei Chemical Co., Ltd.), Surflon S-393 (manufactured by Seimi Chemical Co., Ltd.), F-top EF121, EF122A, EF122B, RF122C, EF125M , EF135M, EF351, 352, EF801, EF802, EF 01 (manufactured by Gemco), PF636, PF656, PF6320, PF6520 (manufactured by OMNOVA), FTX-204D, 208G, 218G, 230G, 204D, 208D, 212D, 218, 222D (manufactured by Neos) 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. Or may be block copolymerized. Examples of the poly (oxyalkylene) group include a poly (oxyethylene) group, a poly (oxypropylene) group, a poly (oxybutylene) group, and the like, and a poly (oxyethylene, oxypropylene, and oxyethylene group). A unit having different chain lengths in the same chain length, such as a block link) or poly (block link of oxyethylene and oxypropylene) may be used. Furthermore, a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate (or methacrylate) is not only a binary copolymer but also a monomer having two or more different fluoroaliphatic groups, Further, it may be a ternary or higher copolymer obtained by simultaneously copolymerizing two or more different (poly (oxyalkylene)) acrylates (or methacrylates).

Examples of commercially available surfactants include Megafac F178, F-470, F-473, F-475, F-476, and F-472 (Dainippon Ink Chemical Co., Ltd.). Further, a copolymer of an acrylate (or methacrylate) having a C ₆ F ₁₃ group and (poly (oxyalkylene)) acrylate (or methacrylate), an acrylate (or methacrylate) having a C ₃ F ₇ group and (poly (oxy) And a copolymer of (ethylene)) acrylate (or methacrylate) and (poly (oxypropylene)) acrylate (or methacrylate).

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

  These surfactants may be used alone or in several combinations.

  (F) The usage-amount of surfactant becomes like this. Preferably it is 0.01-10 mass% with respect to positive resist composition whole quantity (except a solvent), More preferably, it is 0.1-5 mass%.

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

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

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

  The content of the carboxylic acid onium salt in the composition is generally 0.1 to 20% by mass, preferably 0.5 to 10% by mass, and more preferably 1%, based on the total solid content of the composition. -7% by mass.

(H) Other Additives The positive resist composition of the present invention further has solubility in dyes, plasticizers, photosensitizers, light absorbers, alkali-soluble resins, dissolution inhibitors and developers as necessary. (For example, a phenol compound having a molecular weight of 1000 or less, an alicyclic compound having a carboxyl group, or an aliphatic compound) and the like can be contained.

Such phenolic compounds having a molecular weight of 1000 or less can be obtained by referring to, for example, the methods described in JP-A-4-1222938, JP-A-2-28531, US Pat. No. 4,916,210, European Patent 219294, etc. It can be easily synthesized by those skilled in the art.
Specific examples of alicyclic or aliphatic compounds having a carboxyl group include carboxylic acid derivatives having a steroid structure such as cholic acid, deoxycholic acid, lithocholic acid, adamantane carboxylic acid derivatives, adamantane dicarboxylic acid, cyclohexane carboxylic acid, cyclohexane Examples thereof include, but are not limited to, dicarboxylic acids.

(I) Pattern Forming Method The positive resist composition of the present invention is preferably used at a film thickness of 30 to 500 nm, more preferably at a film thickness of 30 to 250 nm, from the viewpoint of improving resolution. Even more preferably, it is used in a thickness of 30 to 200 nm. Such a film thickness can be obtained by setting the solid content concentration in the positive resist composition to an appropriate range to give an appropriate viscosity and improving the coating property and film forming property.
The total solid content concentration in the positive resist composition is generally 1 to 10% by mass, more preferably 1 to 8.0% by mass, and still more preferably 1.0 to 6.0% by mass.

  The positive resist 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 then 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 resist 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 a coater, and dried to form a photosensitive film. Form. In addition, you may coat a well-known antireflection film beforehand.
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.

Examples of the actinic ray or radiation include infrared light, visible light, ultraviolet light, far ultraviolet light, X-ray, electron beam, etc., preferably 250 nm or less, more preferably 220 nm or less, particularly preferably 1 to 1. Far ultraviolet light having a wavelength of 200 nm, specifically, KrF excimer laser (248 nm), ArF excimer laser (193 nm), F ₂ excimer laser (157 nm), X-ray, electron beam, etc. ArF excimer laser, F ₂ Excimer laser, EUV (13 nm), and electron beam are preferable.

Before forming the resist film, an antireflection film may be coated on the substrate in advance.
As the antireflection film, any of an inorganic film type such as titanium, titanium dioxide, titanium nitride, chromium oxide, carbon, and amorphous silicon, and an organic film type made of a light absorber and a polymer material can be used. In addition, as the organic antireflection film, commercially available organic antireflection films such as DUV30 series, DUV-40 series manufactured by Brewer Science, AR-2, AR-3, AR-5 manufactured by Shipley, etc. may be used. it can.

In the development step, an alkaline developer is used as follows. As an alkaline developer of the resist composition, inorganic hydroxides such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia, primary amines such as ethylamine and n-propylamine, Secondary amines such as diethylamine and di-n-butylamine, tertiary amines such as triethylamine and methyldiethylamine, alcohol amines such as dimethylethanolamine and triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide and the like Alkaline aqueous solutions such as quaternary ammonium salts, cyclic amines such as pyrrole and pihelidine can be used.
Furthermore, alcohols and surfactants can be added in appropriate amounts to the alkaline developer.
The alkali concentration of the alkali developer is usually from 0.1 to 20% by mass.
The pH of the alkali developer is usually from 10.0 to 15.0.
Furthermore, alcohols and surfactants can be added in appropriate amounts to the alkaline aqueous solution.
As the rinsing liquid, pure water can be used, and an appropriate amount of a surfactant can be added.
Further, after the development process or the rinsing process, a process of removing the developer or the rinsing liquid adhering to the pattern with a supercritical fluid can be performed.
The development process or the rinsing process may be performed by forming a paddle or may be performed by a paddleless process.
In the case of immersion exposure, a rinsing step may be performed before and after exposure.

  Exposure (immersion exposure) may be performed by filling a liquid (immersion medium) having a higher refractive index than air between the resist 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.

The immersion liquid used for the immersion exposure will be described below.
The immersion liquid is preferably a liquid that is transparent to the exposure wavelength and has a refractive index temperature coefficient as small as possible so as to minimize distortion of the optical image projected onto the resist. In the case of an ArF excimer laser (wavelength: 193 nm), it is preferable to use water from the viewpoints of availability and ease of handling in addition to the above-described viewpoints.
Further, a medium having a refractive index of 1.5 or more can be used in that the refractive index can be further improved. This medium may be an aqueous solution or an organic solvent.

  When water is used as the immersion liquid, the surface tension of the water is reduced and the surface activity is increased, so that the resist layer on the wafer is not dissolved and the influence on the optical coating on the lower surface of the lens element can be ignored. An additive (liquid) may be added in a small proportion. The additive is preferably an aliphatic alcohol having a refractive index substantially equal to that of water, and specifically includes methyl alcohol, ethyl alcohol, isopropyl alcohol and the like. By adding an alcohol having a refractive index substantially equal to that of water, even if the alcohol component in water evaporates and the content concentration changes, an advantage that the change in the refractive index of the entire liquid can be made extremely small can be obtained. On the other hand, when an opaque material or impurities whose refractive index is significantly different from that of water are mixed with 193 nm light, the optical image projected on the resist is distorted, so that distilled water is preferable as the water to be used. Further, pure water filtered through an ion exchange filter or the like may be used.

The electrical resistance of water is preferably 18.3 MQcm or more, and TOC (organic concentration)
Is desirably 20 ppb or less, and it is desirable to perform deaeration treatment.
Moreover, it is possible to improve lithography performance by increasing the refractive index of the immersion liquid. From such a viewpoint, an additive for increasing the refractive index may be added to water, or heavy water (D ₂ O) may be used instead of water.

  In the positive resist composition of the present invention, since the resin (C) contained in the resist is unevenly distributed on the surface, the contact angle (particularly the receding contact angle) of the film surface can be improved. When the resist film is formed, the receding contact angle of water with respect to the resist film is preferably 65 ° or more, and more preferably 70 ° or more. The receding contact angle of the film when only the resin (C) is dissolved and applied is preferably 70 ° to 110 °. By adjusting the addition amount of the resin (C), the receding contact angle of the resist film is adjusted to 60 ° to 80 ° for use. Here, the receding contact angle is at normal temperature and pressure. The receding contact angle is the receding contact angle when the droplet starts to drop when the resist film is tilted.

Since the resist film is not directly brought into contact with the immersion liquid between the resist film of the positive resist composition of the present invention and the immersion liquid, it is also referred to as an “immersion liquid hardly soluble film” (hereinafter referred to as “top coat”). ) May be provided. The necessary functions for the top coat are suitability for application to the upper layer of the resist, radiation, especially transparency to 193 nm, and poor immersion liquid solubility. It is preferable that the top coat is not mixed with the resist and can be uniformly applied to the resist upper layer.
From the viewpoint of 193 nm transparency, the topcoat is preferably a polymer that does not contain an aromatic, and specifically, a hydrocarbon polymer, an acrylate polymer, a polymethacrylic acid, a polyacrylic acid, a polyvinyl ether, a silicon-containing polymer, And fluorine-containing polymers. From the viewpoint of contaminating the optical lens when impurities are eluted from the top coat into the immersion liquid, it is preferable that the residual monomer component of the polymer contained in the top coat is small.

When peeling the top coat, a developer may be used, or a separate release agent may be used. As the release agent, a solvent having a small penetration into the resist is preferable. It is preferable that the peeling process can be performed with an alkali developer in that the peeling process can be performed simultaneously with the resist development process. The top coat is preferably acidic from the viewpoint of peeling with an alkali developer, but may be neutral or alkaline from the viewpoint of non-intermixability with the resist.
The resolution is improved when there is no difference in refractive index between the top coat and the immersion liquid. In the case of using water as the immersion liquid in an ArF excimer laser (wavelength: 193 nm), the top coat for ArF immersion exposure is preferably close to the refractive index of the immersion liquid. From the viewpoint of making the refractive index close to the immersion liquid, it is preferable to have fluorine atoms in the topcoat. A thin film is more preferable from the viewpoint of transparency and refractive index.

  It is preferable that the top coat is not mixed with the resist and further not mixed with the immersion liquid. From this viewpoint, when the immersion liquid is water, the topcoat solvent is preferably a resist solvent hardly soluble and water-insoluble medium. Furthermore, when the immersion liquid is an organic solvent, the topcoat may be water-soluble or water-insoluble.

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

Synthesis Example 1 (Synthesis of Resin (1))
Under a nitrogen stream, 8.6 g of cyclohexanone was placed in a three-necked flask and heated to 80 ° C. To this, 9.8 g of 2-adamantyl isopropyl methacrylate, 4.4 g of dihydroxyadamantyl methacrylate, 8.9 g of norbornane lactone methacrylate, and 8 mol% of a polymerization initiator V-601 (manufactured by Wako Pure Chemical Industries) were dissolved in 79 g of cyclohexanone. The solution was added dropwise over 6 hours. 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 added dropwise over 20 minutes to a mixture of 800 m of hexane / 200 ml of ethyl acetate, and the precipitated powder was collected by filtration and dried to obtain 19 g of Resin (1). The weight average molecular weight of the obtained resin was 8800 in terms of standard polystyrene, and the dispersity (Mw / Mn) was 1.9.

The structure of the acid-decomposable resin (A) used in the examples is shown below. Tables 1 to 4 below show the molar ratio of repeating units in each resin (in order from the left in the structural formula), weight average molecular weight, and degree of dispersion.
The resin (19) was synthesized according to Japanese Patent Application Laid-Open No. 2004-124082 and Example 2.
Resin (22) was synthesized in accordance with JP 2005-331918 A and Examples.
The resin (23) was synthesized according to Japanese Patent Application Laid-Open No. 2004-175981 and Example 1.
Resin (25) was synthesized according to Japanese Patent Application Laid-Open No. 2005-156726, Example 1.

Synthesis Example 2 (Synthesis of Compound (A))
In a 1 L three-necked flask, 23.2 g of 2,4-dimethyl-3-pentanol, 33.3 mL of triethylamine, and 400 mL of tetrahydrofuran were adjusted and ice-cooled. To this solution, a solution prepared by dissolving 38 g of 2-trifluoromethylacrylic acid chloride in 200 mL of tetrahydrofuran was added dropwise over 1 hour and stirred for 1 hour. After completion of the reaction, the reaction mixture was neutralized with 2 mol / L dilute hydrochloric acid and extracted twice with ethyl acetate. The oil layer was washed with a saturated aqueous solution of sodium bicarbonate and pure water. The oil layer was dried over sodium sulfate and concentrated, and then separated on a silica gel column (hexane: ethyl acetate = 9: 1) to obtain 30 g of the following compound (A) as the objective product.
¹ H-NMR (400 MHz, CDCl3) δ 0.91 (td, 12H), 1.98 (m, 2H), 4.76 (t, 1H), 6.41 (s, 1H), 6.73 (s, 1H)

Synthesis Example 3: Synthesis of Resin (C-1) Heptafluorobutyl methacrylate and t-butyl methacrylate were charged at a ratio (molar ratio) of 50/50, dissolved in cyclohexanone, and 450 g of a solution having a solid content concentration of 22% was added. Prepared. To this solution was added 5 mol% of a polymerization initiator V-601 manufactured by Wako Pure Chemical Industries, Ltd., and this was added dropwise to 50 mL of cyclohexanone heated to 80 ° C. over 2 hours in a nitrogen atmosphere. After completion of dropping, the reaction solution was stirred for 2 hours to obtain a reaction solution (C-1). After completion of the reaction, the reaction solution (C-1) was cooled to room temperature, crystallized in 10 volumes of methanol, and the precipitated white powder was collected by filtration to recover the target resin (C-1).
^The polymer composition ratio determined from ¹ H-NMR was 50/50 (molar ratio). Moreover, the weight average molecular weight of standard polystyrene conversion calculated | required by GPC measurement was 8800, and dispersion degree was 2.1.

Synthesis Example 4: Synthesis of Resin (C-2) A 1 L autoclave was charged with a solution of 25 g (0.20 mol) of trifluoroethyl vinyl ether in 150 ml of 1,1,2-trichloro-trifluoroethylene and added to 200 psi under a nitrogen atmosphere. Pressed. Further, 20 g (0.20 mol) of tetrafluoroethylene was injected and heated to 50 ° C. with stirring. To this reaction solution, a solution of 1.2 g of di (4-t-butylcyclohexyl) peroxydicarbonate in 15 ml of 1,1,2-trichloro-trifluoroethylene was poured over 20 minutes, and stirring was further continued for 20 hours. After completion of the reaction, the reaction solution was poured into 2 L of methanol with vigorous stirring to precipitate a colorless and transparent resin.
The obtained resin had a weight average molecular weight of 5,200 and a dispersity of 1.8 as determined by gel permeation chromatography (GPC). Moreover, the polymer composition ratio calculated | required from 19F-NMR was 50/50.

Synthesis Example 5: Synthesis of Resin (C-3) 0.05 mol of 2-trifluoromethyl methacrylate heptafluorobutyl and 0.05 mol of norbornene were mixed. When this mixture was stirred at 80 ° C. under a nitrogen atmosphere, 1.5 mol% of a polymerization initiator V-59 manufactured by Wako Pure Chemical Industries, Ltd. was added, and the mixture was stirred as it was for 3 hours. Then, it stirred for 12 hours, adding 1.5 mol% of polymerization initiator V-59 every 3 hours. After completion of the reaction, the reaction solution was dissolved in 20 mL of THF and cooled to room temperature. The white powder crystallized and precipitated in 800 mL of methanol was collected by filtration to recover the target resin (C-3).
^The polymer composition ratio determined from ¹ HNMR was 50/50 (in order from the left of the structural formula). Moreover, the weight average molecular weight of standard polystyrene conversion calculated | required by GPC measurement was 4800, and dispersion degree was 1.9.

Synthesis Example 6: Synthesis of Resin (C-6) 50 g of 4- (1,1,1,3,3,3-hexafluoro-2-hydroxypropan-2-yl) styrene was dissolved in 200 mL of cyclohexanone. When this was stirred at 80 ° C. in a nitrogen atmosphere, 5 mol% of a polymerization initiator V-601 manufactured by Wako Pure Chemical Industries, Ltd. was added and stirred for 5 hours. After completion of the reaction, the reaction solution was cooled to room temperature, crystallized in 5 times the amount of hexane, and the precipitated white powder was collected by filtration to recover the target resin (C-6).
The weight average molecular weight in terms of standard polystyrene determined by GPC measurement was 12000, and the degree of dispersion was 2.0.

Synthesis Example 7: Synthesis of Resin (C-7) An equimolar amount of allyltrimethylsilane and maleic anhydride were dissolved in tetrahydrofuran to prepare 450 g of a solution having a solid content concentration of 50% by mass. To this stirred mixture at 65 ° C. under a nitrogen atmosphere, 0.17 mol% of a polymerization initiator V-65 manufactured by Wako Pure Chemical Industries, Ltd. was added and stirred as it was for 5 hours. After completion of the reaction, 100 mL of tetrahydrofuran was added to the reaction solution and dissolved, and then cooled to room temperature. The white powder crystallized and precipitated in 800 mL of hexane was collected by filtration to recover the target resin (C-7).
^The polymer composition ratio determined from ¹ HNMR was 50/50 (in order from the left of the structural formula). Moreover, the weight average molecular weight of standard polystyrene conversion calculated | required by GPC measurement was 5800, and dispersion degree was 1.9.

Resin (C-4) was synthesized in the same manner as in Synthesis Example 4.
Resins (C-5) and (C-10) were synthesized in the same manner as in Synthesis Example 5.
Resins (C-8), (C-30), (C-36) to (C-38), (C-40), (C-
42) was synthesized in the same manner as in Synthesis Example 7 except that the crystallization was changed to a methanol solvent.
Resins (C-9) and (C-22) were synthesized in the same manner as in Synthesis Example 6 except that the crystallization was changed to a methanol solvent.
Resins (C-11) to (C-20), (C-23) to (C-29), (C-31) to (C
-35), (C-39), (C-41), (C-43), (C-44), and (C-45) were synthesized in the same manner as in Synthesis Example 3.
Resin (C-21) was synthesized in the same manner as in Synthesis Example 6.
Resin (C-46) was synthesized in the same manner as in Synthesis Example 7.

  The structures of the resins (C-1) to (C-46) are shown below. Tables 5 to 8 below show the molar ratio of repeating units in each resin (corresponding to each repeating unit in order from the left), weight average molecular weight, dispersity, shape, and glass transition temperature.

Examples 1 to 52 and Comparative Examples 1 to 8
<Resist preparation>
The components shown in Tables 9 to 12 below were dissolved in a solvent, and a solution with a solid content of 6% by mass was prepared for each, and this was filtered through a 0.1 μm polyethylene filter to prepare a positive resist solution. The prepared positive resist composition was evaluated by the following method, and the results are shown in Tables 9 to 12 below. In addition, about each component in Tables 9-12, ratio when using two or more is a mass ratio.

[Image performance test]
(Exposure condition (1))
An organic antireflection film ARC29A (Nissan Chemical Co., Ltd.) was applied on a silicon wafer and baked at 205 ° C. for 60 seconds to form a 78 nm antireflection film. The positive resist composition prepared thereon was applied and baked at 130 ° C. for 60 seconds to form a 250 nm resist film. The obtained wafer was subjected to pattern exposure using an ArF excimer laser scanner (PAS5500 / 1100, NA0.75, σo / σi = 0.85 / 0.55, manufactured by ASML). Thereafter, heating was performed at 130 ° C. for 60 seconds, followed by development with an aqueous tetramethylammonium hydroxide solution (2.38 mass%) for 30 seconds, rinsing with pure water, and spin drying to obtain a resist pattern.

(Exposure condition (2))
This condition is to form a resist pattern by an immersion exposure method using pure water.
An organic antireflection film ARC29A (Nissan Chemical Co., Ltd.) was applied on a silicon wafer and baked at 205 ° C. for 60 seconds to form a 78 nm antireflection film. The positive resist composition prepared thereon was applied and baked at 130 ° C. for 60 seconds to form a 250 nm resist film. The obtained wafer was subjected to pattern exposure using an ArF excimer laser immersion scanner (NA 0.85). Ultra pure water was used as the immersion liquid. Thereafter, heating was performed at 130 ° C. for 60 seconds, followed by development with an aqueous tetramethylammonium hydroxide solution (2.38 mass%) for 30 seconds, rinsing with pure water, and spin drying to obtain a resist pattern.

[PED evaluation]
In (Exposure Condition 1) and (Exposure Condition 2), a scanning electron microscope (S-4800 manufactured by Hitachi, Ltd.) was used for the obtained resist pattern and the resist pattern obtained by performing the same operation as described above after being left for 30 minutes after exposure. ) Was used to observe the pattern collapse performance and pattern profile.
Pattern collapse occurs when the exposure amount for reproducing a 90 nm line and space pattern is the optimum exposure amount, and the dense pattern of line and space 1: 1 and the isolated pattern of line and space 1:10 are exposed at the optimum exposure amount. The line width at which the pattern was resolved without falling down in a fine mask size was defined as the limit pattern falling line width. The smaller the value, the finer pattern is resolved without falling, and the pattern collapse is less likely to occur.

[Water followability]
The prepared positive resist composition was applied on a silicon wafer and baked at 130 ° C. for 60 seconds to form a 160 nm resist film. Next, as shown in FIG. 1, pure water 2 was filled between the wafer 1 coated with the obtained positive resist composition and the quartz glass substrate 3.
In this state, the quartz glass substrate 3 was moved (scanned) in parallel to the surface of the resist-coated substrate 1, and the state of the pure water 2 following it was visually observed. Gradually increase the scan speed of the quartz glass substrate 3 and evaluate the water followability by obtaining the limit scan speed at which the pure water 2 cannot follow the scan speed of the quartz glass substrate 3 and water droplets begin to remain on the receding side. went. As this limit scan speed is larger, water can follow a higher scan speed, and the water followability on the resist film is better.

The symbols in Tables 9 to 12 are as follows.
The acid generator corresponds to that exemplified above.

N-1: N, N-dibutylaniline N-2: N, N-dihexylaniline N-3: 2,6-diisopropylaniline N-4: tri-n-octylamine N-5: N, N-dihydroxyethyl Aniline N-6: 2,4,5-triphenylimidazole N-7: Tris (methoxyethoxyethyl) amine N-8: 2-phenylbenzimidazole

W-1: Megafuck F176 (manufactured by Dainippon Ink & Chemicals, Inc.)
(Fluorine)
W-2: Megafuck R08 (Dainippon Ink Chemical Co., Ltd.)
(Fluorine and silicon)
W-3: Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.)
(Silicon)
W-4: Troisol S-366 (manufactured by Troy Chemical Co., Ltd.)
W-5: PF656 (manufactured by OMNOVA, fluorine-based)
W-6: PF6320 (manufactured by OMNOVA, fluorine-based)
W-7: PF6520 (manufactured by OMNOVA, fluorine-based)

SL-1: Cyclohexanone SL-2: Propylene glycol monomethyl ether acetate SL-3: Ethyl lactate SL-4: Propylene glycol monomethyl ether SL-5: γ-butyrolactone SL-6: Propylene carbonate

  The additive (H-1) used in Comparative Example 7 and the additive (H-2) used in Comparative Example 8 are compounds used for comparison with the resin (C).

  From the results in Tables 9 to 12, the positive resist composition of the present invention has less resist pattern collapse and profile deterioration due to the placement between exposure and PEB, not only in normal exposure but also in immersion exposure, It can be seen that the followability to the immersion liquid is good in the immersion exposure.

Further, the positive resist compositions of Examples 1 to 52 were evaluated under the exposure conditions (1) and (2) even when the exposure conditions were changed to the following (3) to (6). A rectangular pattern was obtained as before.
(Exposure condition (3))
A resist pattern was obtained using the same method as the exposure condition (1) except that the baking temperature after applying the resist composition was 90 ° C. and the post-heating temperature after exposure was 110 ° C.
(Exposure condition (4))
A resist pattern was obtained using the same method as the exposure condition (2) except that the baking temperature after applying the resist composition was 90 ° C. and the post-heating temperature after exposure was 110 ° C.
(Exposure condition (5))
A resist pattern was formed using the same method as in exposure condition (1) except that the resist composition was applied to form a 150 nm film, the post-heating temperature after exposure was 90 ° C., and the development time was 90 seconds. Obtained.
(Exposure condition (6))
A resist pattern was formed using the same method as in the exposure condition (2) except that the resist composition was applied to form a 150 nm film, the post-heating temperature after exposure was 90 ° C., and the development time was 90 seconds. Obtained.

Schematic diagram of water followability evaluation method

Explanation of symbols

1 wafer 2 pure water 3 quartz glass substrate

Claims (12)

(A) a resin having a monocyclic or polycyclic alicyclic hydrocarbon structure and having increased solubility in an alkali developer by the action of an acid;
(B) a compound that generates an acid upon irradiation with an actinic ray or radiation,
A positive resist composition comprising (C) a resin having at least one of a fluorine atom and a silicon atom, and (D) a solvent.   The positive resist composition according to claim 1, wherein the resin (C) is solid at 25 ° C.   3. The positive resist composition according to claim 1, wherein the resin (C) has a glass transition temperature in the range of 50 to 200 ° C. 4. The positive resist composition according to claim 1, wherein the resin (C) has a group represented by the following general formula (F3a).

In general formula (F3a),
R _62a and R _63a each independently represents an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom. R _62a and R _63a may be connected to each other to form a ring.
R _64a represents a hydrogen atom, a fluorine atom or an alkyl group. The positive resist composition according to claim 1, wherein the resin (C) has groups represented by the following general formulas (CS-1) to (CS-3).

In general formulas (CS-1) to (CS-3),
R _{12 to} R ₂₆ each independently represents a linear or branched alkyl group or a cycloalkyl group.
L < ₃ > -L < ₅ > represents a single bond or a bivalent coupling group. The positive resist composition according to claim 1, wherein the resin (C) is any resin selected from the following (C-1) to (C-6).
(C-1) A resin having a repeating unit (a) having a fluoroalkyl group.
(C-2) A resin having a repeating unit (b) having a trialkylsilyl group or a cyclic siloxane structure.
(C-3) Resin having a repeating unit (a) having a fluoroalkyl group and a repeating unit (c) having a branched alkyl group, a cycloalkyl group, a branched alkenyl group, a cycloalkenyl group or an aryl group .
(C-4) a repeating unit (b) having a trialkylsilyl group or a cyclic siloxane structure and a repeating unit having a branched alkyl group, cycloalkyl group, branched alkenyl group, cycloalkenyl group or aryl group (c ).
(C-5) A resin having a repeating unit (a) having a fluoroalkyl group and a repeating unit (b) having a trialkylsilyl group or a cyclic siloxane structure.
(C-6) a repeating unit (a) having a fluoroalkyl group, a repeating unit (b) having a trialkylsilyl group or a cyclic siloxane structure, a branched alkyl group, a cycloalkyl group, a branched alkenyl group, A resin having a repeating unit (c) having a cycloalkenyl group or an aryl group. Resin (C) has a repeating unit represented by the following general formula (Ia), The positive resist composition in any one of Claims 1-3 characterized by the above-mentioned.

In general formula (Ia):
Rf represents a fluorine atom or an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom.
R ₁ represents an alkyl group.
R ₂ represents a hydrogen atom or an alkyl group. Resin (C) has the repeating unit represented by the following general formula (II), and the repeating unit represented by the following general formula (III), The positive in any one of Claims 1-3 characterized by the above-mentioned. Type resist composition.

In general formulas (II) and (III):
Rf represents a fluorine atom or an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom.
R ₃ represents an alkyl group, a cycloalkyl group, an alkenyl group or a cycloalkenyl group.
R ₄ represents an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, a trialkylsilyl group, or a group having a cyclic siloxane structure.
L ₆ represents a single bond or a divalent linking group.
0 <m <100.
0 <n <100. A compound represented by the following general formula (I):

In general formula (I),
Rf represents a fluorine atom or an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom.
R ₁ represents an alkyl group.
R ₂ represents a hydrogen atom or an alkyl group. A resin having a repeating unit represented by the following general formula (Ia):

In general formula (Ia):
Rf represents a fluorine atom or an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom.
R ₁ represents an alkyl group.
R ₂ represents a hydrogen atom or an alkyl group. A resin having a repeating unit represented by the following general formula (II) and a repeating unit represented by the following general formula (III).

In general formulas (II) and (III):
Rf represents a fluorine atom or an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom.
R ₃ represents an alkyl group, a cycloalkyl group, an alkenyl group or a cycloalkenyl group.
R ₄ represents an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, a trialkylsilyl group, or a group having a cyclic siloxane structure.
L ₆ represents a single bond or a divalent linking group.
0 <m <100.
0 <n <100.   A pattern forming method comprising: forming a resist film from the positive resist composition according to claim 1, exposing and developing the resist film.

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