JP2005316259A - Positive resist composition for dipping exposure, and pattern forming method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a positive resist composition suitable for a dipping exposure which is less in a PEB (Post Exposure Bake) temperature dependence and improved in deterioration of pattern collapse due to post exposure delay between the exposure and the PEB in the dipping exposure, and to provide a method for forming a pattern by using the composition. <P>SOLUTION: The positive resist composition for dipping exposure contains: (A) a resin which has the main chain comprising only a methacrylic repeating unit and has an alicyclic hydrocarbon structure, and the solubility of which with an alkali developing solution increases by the effect of an acid; and (B) a compound which generates an acid by irradiation of actinic rays or radiation. The method for forming a pattern is carried out by using the composition. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

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

With the miniaturization of semiconductor elements, the wavelength of the exposure light source has been shortened and the projection lens has a high numerical aperture (high NA). At present, an exposure machine with NA 0.84 using an ArF excimer laser having a wavelength of 193 nm as a light source has been developed. ing. The resolution and the depth of focus 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.

As for an apparatus that applies this effect to the transfer of a fine pattern of a semiconductor element (for example, see Patent Document 1) and a pattern formation method based on a process that uses a liquid immersion technique (for example, see Patent Document 2), the technology has already been disclosed. However, a resist suitable for the immersion exposure technique has not been discussed yet.
In Patent Document 3, it is pointed out that the refractive index control of the immersion liquid is important because the refractive index change of the immersion liquid causes deterioration of the projected image due to the wavefront aberration of the exposure machine. Water having a temperature coefficient controlled within a certain range, or water added with an additive that lowers the surface tension or increases the surface activity is disclosed as a suitable immersion liquid. However, the disclosure of additives and the resist suitable for the immersion exposure technique are not discussed.

Recent progress of immersion exposure technology is reported in Non-Patent Document 1 (SPIE Proc, 4688, 11 (2002)), Non-Patent Document 2 (J. Vac. Sci. Tecnol. B, 17 (1999)), etc. . In the case of using an ArF excimer laser as a light source, pure water (refractive index at 193 nm: 1.44) 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 solution from the viewpoint of environmental safety and refractive index has not yet been found. 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.
In immersion exposure, the resist film and the optical lens are filled with an immersion liquid (also referred to as an immersion liquid) and exposed through a photomask to transfer the photomask pattern to the resist film. By penetrating into the resist film, it is expected to influence a chemical reaction (acid-catalyzed deprotection reaction, development reaction) caused in the resist during or after exposure. However, the extent and mechanism of the effect is still unknown.

  When a chemically amplified resist is applied to the immersion exposure technique, the acid on the resist surface generated during exposure moves to the immersion liquid, and the acid concentration on the exposed portion surface changes. This is the surface of the exposed area caused by a very small amount of basic contamination of several ppb level from the environment during exposure-PEB placement (PED: Post Exposure time Delay), which was a major problem at the beginning of the development of chemically amplified positive resists. Although it is thought that it is very similar to acid deactivation, the influence and mechanism of immersion exposure on the resist have not been clarified yet.

  For example, when a chemically amplified resist that does not have a problem with lithography in normal exposure is subjected to immersion exposure, the profile is deteriorated due to placement between exposure and PEB, and improvement is necessary. In addition, it has been found that temperature variations in heating (PEB) by a hot plate after exposure affect the obtained pattern, and it has been desired to improve such PEB temperature dependency.

JP-A-6-124873 Japanese Examined Patent Publication No. 63-49893 JP-A-10-303114 Proc. SPIE, 2002, Vol. 4688, p. 11 J. Vac. Sci. Tecnol. B 17 (1999)

  The object of the present invention is to solve the above-mentioned problems of the prior art. The immersion exposure is less dependent on the PEB temperature, and the deterioration of the pattern collapse due to the placement between the exposure and the PEB during the immersion exposure is improved. And a pattern forming method using the positive resist composition.

The present invention is a positive resist composition for immersion exposure having the following constitution, whereby the above object of the present invention is achieved.
(1) (A) Resin whose main chain consists only of a methacrylic repeating unit and has an alicyclic hydrocarbon structure, whose solubility in an alkali developer increases by the action of an acid, and (B) irradiation with actinic rays or radiation A positive resist composition for immersion exposure, comprising a compound that generates an acid when heated.
(2) The positive for immersion exposure as described in (1) above, wherein the resin (A) has at least two different repeating units selected from the repeating units represented by the following general formula (I): Type resist composition.

In the general formula (Ia), Ra represents a group having at least one of an alicyclic hydrocarbon structure and a lactone structure.
(3) The positive resist composition for immersion exposure as described in (1) or (2) above, further comprising an additive compound represented by the following general formula (II).

In general formula (II),
X represents an alkylene group.
Q represents a single bond or a divalent linking group.
R ₁ and R ₂ are each independently a chlorine atom, bromine atom, iodine atom, hydroxyl group, alkoxy group, epoxy group, amino group, cyano group, acyl group, acyloxy group, lactone group, carboxylic acid group and aromatic group It represents a single group selected from the group consisting of or a combination of two or more groups.
n represents an integer of 1 to 5.
When a plurality of X and Q are present, they may be the same or different.
(4) A pattern forming method comprising: forming a resist film from the positive resist composition as described in (1) to (3) above; and exposing and developing the resist film by immersion exposure.

  INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a positive resist composition suitable for immersion exposure that is not easily affected by fluctuations in processing conditions such as a holding time after exposure and a post-heating temperature, and a pattern forming method using the same. .

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

[1] Resin whose solubility in an alkaline developer is increased by the action of an acid The resin contained in the positive resist composition for immersion exposure according to the present invention has an alicyclic hydrocarbon structure whose main chain consists only of methacrylic repeating units. A resin (also referred to as an acid-decomposable resin (A)) whose solubility in an alkali developer is increased by the action of an acid.

[Acid-decomposable group]
The resin contained in the positive resist composition for immersion exposure according to the present invention is a resin (acid-decomposable resin) whose solubility in an alkaline developer is increased by the action of an acid, and is decomposed by the action of an acid to form an alkali-soluble group. Contains a repeating unit having a resulting group (acid-decomposable group).
Examples of the alkali-soluble group include a phenolic hydroxyl group, a carboxy group, a sulfonic acid group, and a thiol group, and a carboxy group and a sulfonic acid group are preferable.
The acid-decomposable group may be present in the main chain or side chain of the resin, or in both the main chain and side chain.
A preferred group as the acid-decomposable group is a group in which the hydrogen atom of the —COOH group is substituted with a group capable of leaving with an acid.
Examples of the acid-decomposable group include a cumyl ester group, an enol ester group, an acetal ester group, and a tertiary alkyl ester group. More preferred examples include tertiary alkyl ester groups.

Examples of the acid-decomposable group that the acid-decomposable resin (A) may have include —O—C (R ₃₆ ) (R ₃₇ ) (R ₃₈ ), —O—C (R ₃₆ ) (R _{37) (OR 39), -} O-C (= O) -O-C (R 36) (R 37) (R 38), - O-C (R 01) (R 02) (OR 39), - OC (R ₀₁ ) (R ₀₂ ) —C (═O) —O—C (R ₃₆ ) (R ₃₇ ) (R ₃₈ ) and the like can be mentioned.
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 , R ₃₆ and R ₃₉ 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.
Note that —C (R ₃₆ ) (R ₃₇ ) (R ₃₈ ) means a group in which each group represented by R _{36 to} R ₃₈ is bonded to a carbon atom with a single bond. The same shall apply hereinafter.
Preferable acid-decomposable groups include acid-decomposable groups in which an alkali-soluble group is protected with a group having an alicyclic hydrocarbon group represented by formulas (pI) to (pV) described later.

The acid-decomposable group may be contained in any methacrylic repeating unit constituting the acid-decomposable resin (A).
In the acid-decomposable resin (A), the content of the repeating unit having an acid-decomposable group is preferably 10 to 70 mol%, more preferably 20 to 65 mol%, still more preferably in all repeating units. It is 25-50 mol%.

[Methacrylic repeating unit]
The acid-decomposable resin (A) has a main chain composed only of methacrylic repeating units. The methacrylic repeating unit is a repeating unit derived from methacrylic acid or a methacrylic ester.

[Alicyclic hydrocarbon structure]
The alicyclic hydrocarbon structure of the acid-decomposable resin (A) may be monocyclic or polycyclic. Specific examples include groups having a monocyclo, bicyclo, tricyclo, tetracyclo structure or the like having 5 or more carbon atoms. The carbon number is preferably 6-30, and particularly preferably 7-25. These alicyclic hydrocarbon structures may have a substituent.

Preferred examples of the alicyclic hydrocarbon structure include adamantyl group, decalin residue, tricyclodecanyl group, tetracyclododecanyl group, norbornyl group, cedrol group, cyclohexyl group, cycloheptyl when expressed as a monovalent group. Group, cyclooctyl group, cyclodecanyl group and cyclododecanyl group. More preferable examples include an adamantyl group, a decalin residue, a norbornyl group, a cedrol group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecanyl group, and a cyclododecanyl group.

  These alicyclic hydrocarbon structures may have a substituent, and examples of the substituent include an alkyl group, a halogen atom, a hydroxyl group, an alkoxy group, a carboxy group, and an alkoxycarbonyl group. The alkyl group is preferably a lower alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, or a butyl group, and more preferably selected from the group consisting of a methyl group, an ethyl group, a propyl group, and an isopropyl group. Examples of the alkoxy group include those having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, and a butoxy group. 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 (preferably having 1 to 4 carbon atoms).

  As the alicyclic hydrocarbon structure possessed by the acid-decomposable resin (A), partial structures containing alicyclic hydrocarbons represented by the following general formulas (pI) to (pV) are more preferred.

In the formula, R ₁₁ represents a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group or a sec-butyl group, and Z forms an alicyclic hydrocarbon group together with a carbon atom. Represents the atomic group necessary to do.
R _{12 to} R ₁₆ each independently represents a linear or branched alkyl group or alicyclic hydrocarbon group having 1 to 4 carbon atoms, provided that at least one of R _{12 to} R ₁₄ , or Either R ₁₅ or R ₁₆ represents an alicyclic hydrocarbon group.
R _{17 to} R ₂₀ each independently represents a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or an alicyclic hydrocarbon group, provided that at least one of R _{17 to} R ₂₀ Represents an alicyclic hydrocarbon group. R ₁₈ and R ₁₉ may be bonded to each other to form a ring.

The alicyclic hydrocarbon group in R _{11 to} R _{20 or} the alicyclic hydrocarbon group formed by Z and a carbon atom may be monocyclic or polycyclic. Specific examples include groups having a monocyclo, bicyclo, tricyclo, tetracyclo structure or the like having 5 or more carbon atoms. The carbon number is preferably 6-30, and particularly preferably 7-25. These alicyclic hydrocarbon groups may have a substituent.

  Preferred examples of the alicyclic hydrocarbon group include an adamantyl group, a noradamantyl group, a decalin residue, a tricyclodecanyl group, a tetracyclododecanyl group, a norbornyl group, a cedrol group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. Group, cyclodecanyl group, and cyclododecanyl group. More preferred are an adamantyl group, a decalin residue, a norbornyl group, a cedrol group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecanyl group, and a cyclododecanyl group.

  Examples of the substituent that these alicyclic hydrocarbon groups may have include an alkyl group, a halogen atom, a hydroxyl group, an alkoxy group, a carboxy group, and an alkoxycarbonyl group. The alkyl group is preferably a lower alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, or a butyl group, and more preferably selected from the group consisting of a methyl group, an ethyl group, a propyl group, and an isopropyl group. Examples of the alkoxy group include those having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, and a butoxy group. 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 (preferably having 1 to 4 carbon atoms).

  The structures represented by the general formulas (pI) to (pV) in the resin can be used for protecting an alkali-soluble group, and can constitute an acid-decomposable group as described above.

As the alkali-soluble group protected by the structure represented by the general formulas (pI) to (pV) in the resin, the hydrogen atom of the carboxy group is preferably substituted with the structure represented by the general formulas (pI) to (pV). Structure.
For example, a repeating unit represented by the following general formula (Ib) is preferable.

  Here, Rb represents a group represented by any of the above formulas (pI) to (pV).

  The repeating unit represented by the general formula (Ib) is most preferably a repeating unit of 2-alkyl-2-adamantyl methacrylate or dialkyl (1-adamantyl) methyl methacrylate.

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

  Examples of the repeating unit having an alicyclic hydrocarbon structure may further include the following repeating units.

  In the acid-decomposable resin (A), the content of the repeating unit having a partial structure containing an alicyclic hydrocarbon represented by any one of the general formulas (pI) to (pV) is the acid-decomposable resin (A). Is preferably 20 to 70 mol%, more preferably 24 to 65 mol%, and still more preferably 28 to 60 mol% in all repeating structural units constituting the.

  Moreover, it is preferable that acid-decomposable resin (A) has a lactone group, More preferably, it represents with either the following general formula (Lc) or the following general formula (III-1)-(III-5). It has a repeating unit having a group having a lactone structure, and the group having a lactone structure may be directly bonded to the main chain.

In general formula (Lc), Ra ₁ , Rb ₁ , Rc ₁ , Rd ₁ and Re ₁ each independently represents a hydrogen atom or an alkyl group. m and n each independently represent an integer of 0 to 3, and m + n is 2 or more and 6 or less.

In the general formulas (III-1) to (III-5), R _{1b to} R _5b each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylsulfonylimino group, or an alkenyl group. Represents. Two of R _{1b to} R _5b may combine to form a ring.

R _{1 to} Re ₁ alkyl groups in general formula (Lc) and R _{1b to} R _5b alkyl groups, alkoxy groups, alkoxycarbonyl groups, alkyls in general formulas (III-1) to (III-5) Examples of the alkyl group in the sulfonylimino group include linear and branched alkyl groups, which may have a substituent.

  Preferred substituents include an alkoxy group having 1 to 4 carbon atoms, a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), an acyl group having 2 to 5 carbon atoms, an acyloxy group having 2 to 5 carbon atoms, and cyano. A group, a hydroxyl group, a carboxy group, an alkoxycarbonyl group having 2 to 5 carbon atoms, a nitro group, and the like.

  Examples of the repeating unit having a group having a lactone structure include a repeating unit represented by the following general formula (Ic).

  In the general formula (Ic), Rc represents a group having a lactone structure, preferably a lactone structure represented by the above general formula (Lc) or any one of the general formulas (III-1) to (III-5). Represents a group having

Rc is preferably a group represented by -A-Rd.
A represents a single bond, an ether group, an ester group, a carbonyl group, an alkylene group, or a divalent group obtained by combining these, and preferably has 20 or less carbon atoms.
Rd represents a group represented by general formula (Lc) or any one of general formulas (III-1) to (III-5).

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

  The content of the repeating unit having a lactone structure such as the repeating unit represented by the formula (Ic) is preferably 1 to 70 mol%, more preferably, based on all repeating units constituting the acid-decomposable resin (A). Is from 10 to 70 mol%.

  The acid-decomposable resin (A) may contain a repeating unit having a group represented by the following general formula (IV).

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

  The group represented by the general formula (IV) is preferably a dihydroxy body or a monohydroxy body, and more preferably a dihydroxy body.

  Examples of the repeating unit having a group represented by the general formula (IV) include a repeating unit represented by the following general formula (AII).

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

  Although the specific example of the repeating unit which has a structure represented by general formula (AII) below is given, it is not limited to these.

  The content of the repeating unit having a group represented by the general formula (IV) (hydroxyadamantane structure) is preferably from 1 to the total number of moles of the repeating structural unit having a partial structure containing an alicyclic hydrocarbon. It is 70 mol%, More preferably, it is 1-50 mol%.

The resin (A) particularly preferably contains two or more methacrylic repeating units containing a group having at least one of an alicyclic hydrocarbon structure and a lactone structure.
More specifically, it preferably contains at least two different repeating units selected from the repeating units represented by formula (Ia).

  In the general formula (Ia), Ra represents a group having at least one of an alicyclic hydrocarbon structure and a lactone structure.

The details of the repeating unit represented by the formula (Ia) when Ra is a group having an alicyclic hydrocarbon structure are the same as those in the repeating unit represented by the aforementioned formula (Ib), and Ra is a lactone. The details of the repeating unit represented by the formula (Ia) in the case of a group having a structure are the same as those in the repeating unit represented by the aforementioned formula (Ic).

The total content of two or more repeating units represented by formula (Ia) is preferably 50 to 100 mol%, more preferably 60, based on all repeating units constituting the acid-decomposable resin (A). It is -100 mol%, More preferably, it is 70-100 mol%.
Of the two or more repeating units represented by formula (Ia), the content of the repeating unit having the smallest content is 10 mol with respect to the total amount of the repeating units represented by two or more types (Ia). % Or more is preferable.

  In addition to the above repeating structural units, the acid-decomposable resin (A) has dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and general required properties of resist, resolving power, heat resistance, sensitivity. Other methacrylic repeating structural units can be contained for the purpose of adjusting the above.

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

  The acid-decomposable resin (A) can be synthesized according to a conventional method (for example, radical polymerization). For example, as a general synthesis method, monomer species are charged into a reaction vessel in a batch or in the course of reaction, and if necessary, a reaction solvent such as ethers such as tetrahydrofuran, 1,4-dioxane, diisopropyl ether, methyl ethyl ketone, A ketone such as methyl isobutyl ketone, an ester solvent such as ethyl acetate, and the composition of the present invention such as propylene glycol monomethyl ether acetate described below are dissolved in a solvent that dissolves uniformly and then nitrogen, argon, etc. Polymerization is started using a commercially available radical initiator (azo initiator, peroxide, etc.) as necessary under an inert gas atmosphere. If desired, an initiator is added or added in portions, and after completion of the reaction, it is put into a solvent and a desired polymer is recovered by a method such as powder or solid recovery. The concentration of the reaction is usually 20% by mass or more, preferably 30% by mass or more, and more preferably 40% by mass or more. The reaction temperature is usually from 10 ° C to 150 ° C, preferably from 30 ° C to 120 ° C, more preferably from 50 to 100 ° C.

  In the acid-decomposable resin (A), the above repeating structural units may be used alone or in combination. In the present invention, the resins may be used alone or in combination.

  The weight average molecular weight of the acid-decomposable resin (A) is preferably 1,000 to 200,000, more preferably 3000 to 20000 as a polystyrene-converted value by a gas permeation chromatography (GPC) method. By making the weight average molecular weight 1,000 or more, heat resistance and dry etching resistance can be improved, and by making the weight average molecular weight 200,000 or less, developability can be improved. In addition, the viscosity is lowered and the film forming property can be improved.

  The molecular weight distribution (Mw / Mn, also referred to as dispersity) is usually 1 to 5, preferably 1 to 4, more preferably 1 to 3. The molecular weight distribution is preferably 5 or less from the viewpoint of resolution, resist shape, resist pattern side wall, roughness, and the like.

In the positive resist composition of the present invention, the amount of the acid-decomposable resin (A) is preferably 40 to 99.99% by mass, more preferably 50 to 99.97% by mass, based on the total solid content of the resist.
It is.

[2] (B) Compound that generates acid upon irradiation with actinic ray or radiation Compound that generates acid upon irradiation with actinic ray or radiation for use in the positive resist composition for immersion exposure of the present invention (hereinafter, “ The "acid generator" may be referred to below.
The acid generator used in the present invention can be selected from compounds generally used as an acid generator.
That is, it generates an acid upon irradiation with actinic rays or radiation used for photoinitiators of photocationic polymerization, photoinitiators of photoradical polymerization, photodecolorants of dyes, photochromic agents, or microresists. Known compounds and mixtures thereof can be appropriately selected and used.

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

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

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

  Preferred examples of the acid generator include compounds represented by the following general formula (ZI), (ZII) or (ZIII).

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

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

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

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

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

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

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

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

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

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

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

Aryl group R ₂₀₁ to R _203, cycloalkyl group, an alkyl group (for example, 1 to 15 carbon atoms), a cycloalkyl group (e.g., 3 to 15 carbon atoms), an aryl group (e.g., having a carbon number of 6 to 14), You may have an alkoxy group (for example, C1-C15), a halogen atom, a hydroxyl group, a phenylthio group, etc. as a substituent. Preferred substituents are linear or branched alkyl groups having 1 to 12 carbon atoms, cycloalkyl groups having 3 to 12 carbon atoms, and alkoxy groups having 1 to 12 carbon atoms, most preferably alkyl having 1 to 4 carbon atoms. Group, an alkoxy group having 1 to 4 carbon atoms. Alkyl groups R ₂₀₁ to R ₂₀₃ is a cycloalkyl group (e.g., 3 to 15 carbon atoms), an aryl group (e.g., carbon number 6 to 14), an alkoxy group (for example, 1 to 15 carbon atoms), a halogen atom, a hydroxyl group, You may have a phenylthio group etc. as a substituent. The substituent may be substituted on any one of three R ₂₀₁ to R _203, or may be substituted on all three. When R _{201 to} R ₂₀₃ are an aryl group, the substituent is preferably substituted at the p-position of the aryl group.

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

  The non-nucleophilic anion is an anion having an extremely low ability to cause a nucleophilic reaction, and is an anion capable of suppressing degradation with time due to intramolecular nucleophilic reaction. This improves the temporal stability of the resist.

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

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

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

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

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

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

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

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

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

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

  Examples of the sulfonylimide anion include saccharin anion.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

An acid generator can be used individually by 1 type or in combination of 2 or more types.
The content of the acid generator in the positive resist composition for immersion exposure is preferably 0.1 to 20% by mass, more preferably 0.5 to 10% by mass, based on the total solid content of the resist composition. More preferably, it is 1-7 mass%.

[3] Compound Represented by Formula (II) The positive resist composition for immersion exposure of the present invention preferably further contains a compound represented by the following general formula (II).

In general formula (II),
X represents an alkylene group.
Q represents a single bond or a divalent linking group.
R ₁ and R ₂ are each independently a chlorine atom, bromine atom, iodine atom, hydroxyl group, alkoxy group, epoxy group, amino group, cyano group, acyl group, acyloxy group, lactone group, carboxylic acid group and aromatic group It represents a single group selected from the group consisting of or a combination of two or more groups. Here, the combination of two or more groups means that these specific groups may have these specific groups or atoms as a substituent. That is, the compound represented by the formula (II) is a compound having two or more polar groups as groups represented by R ₁ and R ₂ .
n represents an integer of 1 to 5.
When a plurality of X and Q are present, they may be the same or different.

The alkyl group, cycloalkyl group, alkoxy group, acyl group, acyloxy group and aromatic group as R ₁ and R ₂ preferably have 1 to 5 carbon atoms.

  The alkylene group as X is a linear or branched alkylene group, preferably having 4 to 25 carbon atoms, and more preferably 4 to 20 carbon atoms. The alkylene group as X may have a substituent, and examples of the substituent include an aromatic group and a cycloalkyl group (preferably having a carbon number of 5 to 15). Specific examples of the alkylene group as X include propylene group, butylene group, i-butylene group, pentylene group, i-pentylene group, hexylene group, heptylene group, octylene group, nonylene group, decanylene group, 2-ethyl- Examples include a hexylene group, a 3-cyclohexyl-pentylene group, a 4-benzyloctylene group, a 3,3-diphenylpentylene group, a 4,5-dinorbornyloctylene group, and the like.

The divalent linking group of Q includes a cycloalkyl group, an ether group, a thioether group, an acetal group, a carbonyl group, an ester group, an amide group, a sulfonamide group, a sulfonyl group, a sulfone group, a carboxy group, a urethane group, or a urea. A single group selected from the group consisting of groups or a combination of two or more groups can be exemplified, and preferably has 2 to 5 carbon atoms.
80-2000 are preferable and, as for the molecular weight of the compound represented by general formula (II), 80-1000 are more preferable.

  Specific examples of the compound represented by the general formula (II) include n-heptanol, dihexyl ether, 1,8-diethoxyoctane, octanediol, ethoxyethoxyethanol, 1,2-diethyl-1,2-ethanediol. 1,11-dodecanediol, 1,3,6-triphenylhexane, 1,8-octanoic acid dimethyl ester, tetradecanoic acid methyl ester, decanoic acid t-butyl ester, 3,3-diphenyl 1,5-pentanol 1-cyano-10-decanol, (6,6′-diol) -1,2-cyclohexylethane, 1,12-dicyanododecane, dodecylamine, didodecylamine, dicetylamine, tetradecanyldiamine, N, N— Dimethylmethylenediamine, N, N-dimethyltetraethylenepentamine, triisopropyl Pyramine, tripentylamine, trioctylamine, trinonylamine, benzylmethylamine, 1,11-diepoxydodecane, 1,14-di (ethoxyethoxy) tetradecane, dodecylsulfonic acid ethyl ester, N, N-dibutylnonanesulfone Examples include amides.

The compound represented by the general formula (II) can be synthesized by a known method, or a commercially available product may be used. Moreover, you may use individually or in mixture of 2 or more types.

  The addition amount of the compound represented by the general formula (II) is preferably 0.01 to 25% by mass, more preferably 0.01 to 20% by mass, and still more preferably 0.1 to 10% by mass. .

[4] (C) A dissolution inhibiting compound having a molecular weight of 3000 or less, which decomposes by the action of an acid and increases the solubility in an alkaline developer. The positive resist composition for immersion exposure of the present invention is decomposed by the action of an acid. Thus, a dissolution inhibiting compound having a molecular weight of 3000 or less (hereinafter, also referred to as “dissolution inhibiting compound”) that increases the solubility in an alkali developer may be contained.
The dissolution inhibiting compound contains an acid-decomposable group, such as a cholic acid derivative containing an acid-decomposable group described in Proceeding of SPIE, 2724,355 (1996), in order not to lower the permeability of 220 nm or less. Preferred are alicyclic or aliphatic compounds. Examples of the acid-decomposable group and alicyclic structure are the same as those described for the acid-decomposable resin (A).
The molecular weight of the dissolution inhibiting compound in the present invention is 3000 or less, preferably 300 to 3000, and more preferably 500 to 2500.

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

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

[5] (D) Basic compound The positive resist composition for immersion exposure of the present invention preferably further contains a basic compound. As the basic compound, for example, a nitrogen-containing basic compound, a basic ammonium salt, a basic sulfonium salt, a basic iodonium salt, or the like may be used as long as it does not deteriorate sublimation or resist performance.

  The basic compound is a component having an action of controlling a diffusion phenomenon in a resist film of an acid generated from an acid generator by exposure and suppressing an undesirable chemical reaction in a non-exposed region. By blending such a basic compound, the storage stability of the positive resist composition for immersion exposure, which can control the diffusion phenomenon of the acid generated from the acid generator upon exposure in the resist film, is improved. While further improving the resolution as a resist, it is possible to suppress changes in the line width of the resist pattern due to fluctuations in the holding time (PED) from exposure to development processing, and a composition having excellent process stability can be obtained.

  Examples of the nitrogen-containing basic compound include primary, secondary and tertiary aliphatic amines, aromatic amines, heterocyclic amines, nitrogen-containing compounds having a carboxy group, and compounds having a sulfonyl group. Examples thereof include nitrogen compounds, nitrogen-containing compounds having a hydroxyl group, nitrogen-containing compounds having a hydroxyphenyl group, alcoholic nitrogen-containing compounds, amide derivatives, imide derivatives, and nitrogen-containing compounds having a cyano group.

  As aliphatic amines, methylamine, ethylamine, n-propylamine, isopropylamine, n-butylamine, isobutylamine, sec-butylamine, tert-butylamine, pentylamine, tert-amylamine, cyclopentylamine, hexylamine, cyclohexylamine, Heptylamine, octylamine, nonylamine, decylamine, dodecylamine, cetylamine, methylenediamine, ethylenediamine, tetraethylenepentamine, dimethylamine, diethylamine, di-n-propylamine, diisopropylamine, di-n-butylamine, diisobutylamine, di -Sec-butylamine, dipentylamine, dicyclopentylamine, dihexylamine, dicyclohexylamine, diheptylamine , Dioctylamine, dinonylamine, didecylamine, didodecylamine, dicetylamine, N, N-dimethylmethylenediamine, N, N-dimethylethylenediamine, N, N-dimethyltetraethylenepentamine, trimethylamine, triethylamine, tri-n-propylamine , Triisopropylamine, tri-n-butylamine, triisobutylamine, tri-sec-butylamine, tripentylamine, tricyclopentylamine, trihexylamine, tricyclohexylamine, triheptylamine, trioctylamine, trinonylamine, tri Decylamine, tridodecylamine, tricetylamine, N, N, N ′, N′-tetramethylmethylenediamine, N, N, N ′, N′-tetramethylethylenediamine, , N, N ', N'- tetramethyl-tetraethylenepentamine, dimethylethylamine, methylethylpropylamine, benzylamine, phenethylamine, benzyldimethylamine, and the like.

  Aromatic amines and heterocyclic amines include aniline derivatives such as aniline, N-methylaniline, N-ethylaniline, N-propylaniline, N, N-dimethylaniline, 2-methylaniline, 3-methylaniline, 4-methylaniline, ethylaniline, propylaniline, trimethylaniline, 2-nitroaniline, 3-nitroaniline, 4-nitroaniline, 2,4-dinitroaniline, 2,6-dinitroaniline, 3,5-dinitroaniline, N, N-dimethyltoluidine, etc.), diphenyl (p-tolyl) amine, methyldiphenylamine, triphenylamine, phenylenediamine, naphthylamine, diaminonaphthalene, pyrrole derivatives (eg pyrrole, 2H-pyrrole, 1-methylpyrrole, 2,4 -Dimethylpyro , 2,5-dimethylpyrrole, N-methylpyrrole, etc.), oxazole derivatives (eg oxazole, isoxazole etc.), thiazole derivatives (eg thiazole, isothiazole etc.), imidazole derivatives (eg imidazole, 4-methylimidazole, 4 -Methyl-2-phenylimidazole, etc.), pyrazole derivatives, furazane derivatives, pyrroline derivatives (eg pyrroline, 2-methyl-1-pyrroline etc.), pyrrolidine derivatives (eg pyrrolidine, N-methylpyrrolidine, pyrrolidinone, N-methylpyrrolidone etc.) ), Imidazoline derivatives, imidazolidine derivatives, pyridine derivatives (eg pyridine, methylpyridine, ethylpyridine, propylpyridine, butylpyridine, 4- (1-butylpentyl) pyridine, dimethylpyridine) Trimethylpyridine, triethylpyridine, phenylpyridine, 3-methyl-2-phenylpyridine, 4-tert-butylpyridine, diphenylpyridine, benzylpyridine, methoxypyridine, butoxypyridine, dimethoxypyridine, 1-methyl-2-pyridone, 4- Pyrrolidinopyridine, 1-methyl-4-phenylpyridine, 2- (1-ethylpropyl) pyridine, aminopyridine, dimethylaminopyridine, etc.), pyridazine derivatives, pyrimidine derivatives, pyrazine derivatives, pyrazoline derivatives, pyrazolidine derivatives, piperidine derivatives, Piperazine derivatives, morpholine derivatives, indole derivatives, isoindole derivatives, 1H-indazole derivatives, indoline derivatives, quinoline derivatives (eg quinoline, 3-quinolinecarbonitrile) Etc.), isoquinoline derivatives, cinnoline derivatives, quinazoline derivatives, quinoxaline derivatives, phthalazine derivatives, purine derivatives, pteridine derivatives, carbazole derivatives, phenanthridine derivatives, acridine derivatives, phenazine derivatives, 1,10-phenanthroline derivatives, adenine derivatives, adenosine derivatives Guanine derivatives, guanosine derivatives, uracil derivatives, uridine derivatives and the like.

  Examples of the nitrogen-containing compound having a carboxy group include aminobenzoic acid, indolecarboxylic acid, amino acid derivatives (for example, nicotinic acid, alanine, arginine, aspartic acid, glutamic acid, glycine, histidine, isoleucine, glycylleucine, leucine, methionine, phenylalanine. , Threonine, lysine, 3-aminopyrazine-2-carboxylic acid, methoxyalanine) and the like.

  Examples of the nitrogen-containing compound having a sulfonyl group include 3-pyridinesulfonic acid and pyridinium p-toluenesulfonate.

  Examples of the nitrogen-containing compound having a hydroxyl group include 2-hydroxypyridine, aminocresol, 2,4-quinolinediol, 3-indolemethanol hydrate, monoethanolamine, diethanolamine, triethanolamine, N-ethyldiethanolamine, N, N- Diethylethanolamine, triisopropanolamine, 2,2′-iminodiethanol, 2-aminoethanol, 3-amino-1-propanol, 4-amino-1-butanol, 4- (2-hydroxyethyl) morpholine, 2- ( 2-hydroxyethyl) pyridine, 1- (2-hydroxyethyl) piperazine, 1- [2- (2-hydroxyethoxy) ethyl] piperazine, piperidineethanol, 1- (2-hydroxyethyl) pyrrolidine, 1- (2- Hydroxyethyl ) -2-pyrrolidinone, 3-piperidino-1,2-propanediol, 3-pyrrolidino-1,2-propanediol, 8-hydroxyeurolidine, 3-quinuclidinol, 3-tropanol, 1-methyl-2 -Pyrrolidine ethanol, 1-aziridine ethanol, N- (2-hydroxyethyl) phthalimide, N- (2-hydroxyethyl) isonicotinamide and the like are exemplified.

  Examples of amide derivatives include formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, propionamide, benzamide and the like.

  Examples of the imide derivative include phthalimide, succinimide, maleimide and the like.

  Specific examples of the nitrogen-containing compound having a cyano group include 3- (diethylamino) propiononitrile, N, N-bis (2-hydroxyethyl) -3-aminopropiononitrile, N, N-bis (2- Acetoxyethyl) -3-aminopropiononitrile, N, N-bis (2-formyloxyethyl) -3-aminopropiononitrile, N, N-bis (2-methoxyethyl) -3-aminopropiononitrile, N, N-bis [2- (methoxymethoxy) ethyl] -3-aminopropiononitrile, methyl N- (2-cyanoethyl) -N- (2-methoxyethyl) -3-aminopropionate, N- (2 -Cyanoethyl) -N- (2-hydroxyethyl) -3-aminopropionic acid methyl, N- (2-acetoxyethyl) -N- (2-cyanoethyl) Methyl 3-aminopropionate, N- (2-cyanoethyl) -N-ethyl-3-aminopropiononitrile, N- (2-cyanoethyl) -N- (2-hydroxyethyl) -3-aminopropiononitrile, N- (2-acetoxyethyl) -N- (2-cyanoethyl) -3-aminopropiononitrile, N- (2-cyanoethyl) -N- (2-formyloxyethyl) -3-aminopropiononitrile, N -(2-cyanoethyl) -N- (2-methoxyethyl) -3-aminopropiononitrile, N (2-cyanoethyl) -N- [2- (methoxymethoxy) ethyl] -3-aminopropiononitrile, N -(2-cyanoethyl) -N- (3-hydroxy-1-propyl) -3-aminopropiononitrile, N- (3-acetoxy-1-propionitrile ) -N- (2-cyanoethyl) -3-aminopropiononitrile, N- (2-cyanoethyl) -N- (3-formyloxy-1-propyl) -3-aminopropiononitrile, N- (2- Cyanoethyl) -N-tetrahydrofurfuryl-3-aminopropiononitrile, N, N-bis (2-cyanoethyl) -3-aminopropiononitrile, diethylaminoacetonitrile, N, N-bis (2-hydroxyethyl) aminoacetonitrile N, N-bis (2-acetoxyethyl) aminoacetonitrile, N, N-bis (2-formyloxyethyl) aminoacetonitrile, N, N-bis (2-methoxyethyl) aminoacetonitrile, N, N-bis [ 2- (methoxymethoxy) ethyl] aminoacetonitrile, N-cyanomethyl-N- (2- Methoxyethyl) -3-aminopropionate methyl, N-cyanomethyl-N- (2-hydroxyethyl) -3-aminopropionate methyl, N- (2-acetoxyethyl) -N-cyanomethyl-3-aminopropionate methyl N-cyanomethyl-N- (2-hydroxyethyl) aminoacetonitrile, N- (2-acetoxyethyl) -N- (cyanomethyl) aminoacetonitrile, N-cyanomethyl-N- (2-formyloxyethyl) aminoacetonitrile, N -Cyanomethyl-N- (2-methoxyethyl) aminoacetonitrile, N-cyanomethyl-N- [2- (methoxymethoxy) ethyl] aminoacetonitrile, N- (cyanomethyl) -N- (3-hydroxy-1-propyl) amino Acetonitrile, N- (3-acetoxy-1- (Lopyl) -N- (cyanomethyl) aminoacetonitrile, N-cyanomethyl-N- (3-formyloxy-1-propyl) aminoacetonitrile, N, N-bis (cyanomethyl) aminoacetonitrile, 1-pyrrolidinepropiononitrile, 1- Piperidine propiononitrile, 4-morpholine propiononitrile, 1-pyrrolidine acetonitrile, 1-piperidine acetonitrile, 4-morpholine acetonitrile, cyanomethyl 3-diethylaminopropionate, N, N-bis (2-hydroxyethyl) -3-aminopropion Cyanomethyl acid, cyanomethyl N, N-bis (2-acetoxyethyl) -3-aminopropionate, cyanomethyl N, N-bis (2-formyloxyethyl) -3-aminopropionate, N, N-bis (2- Me Xylethyl) -3-aminopropionate cyanomethyl, N, N-bis [2- (methoxymethoxy) ethyl] -3-aminopropionate cyanomethyl, 3-diethylaminopropionic acid (2-cyanoethyl), N, N-bis (2 -Hydroxyethyl) -3-aminopropionic acid (2-cyanoethyl), N, N-bis (2-acetoxyethyl) -3-aminopropionic acid (2-cyanoethyl), N, N-bis (2-formyloxyethyl) ) -3-Aminopropionic acid (2-cyanoethyl), N, N-bis (2-methoxyethyl) -3-aminopropionic acid (2-cyanoethyl), N, N-bis [2- (methoxymethoxy) ethyl] -3-aminopropionic acid (2-cyanoethyl), cyanomethyl 1-pyrrolidinepropionate, 1-piperidine pro Examples include cyanomethyl pionate, cyanomethyl 4-morpholine propionate, 1-pyrrolidinepropionic acid (2-cyanoethyl), 1-piperidinepropionic acid (2-cyanoethyl), 4-morpholine propionic acid (2-cyanoethyl).

As the nitrogen-containing basic compound, 1,5-diazabicyclo [4.3.0] -5-nonene, 1,8-diazabicyclo [5.4.0] -7-undecene, 1,4-diazabicyclo [ 2.2.2] Octane, 4-dimethylaminopyridine, 1-naphthylamine, piperidines, hexamethylenetetramine, imidazoles, hydroxypyridines, pyridines, anilines, hydroxyalkylanilines, 4,4′-diaminodiphenyl ether , Pyridinium p-toluenesulfonate, 2,4,6-trimethylpyridinium p-toluenesulfonate, tetramethylammonium p-toluenesulfonate, tetrabutylammonium lactate, triethylamine, tributylamine, tripentylamine, tri-n-octylami , Tri-i-octylamine, tris (ethylhexyl) amine, tridecylamine, tridodecylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, Tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, cyclohexyldimethylamine, methyldicyclohexylamine, ethylenediamine, N, N, N ′, N′-tetramethylethylenediamine, Tetramethylenediamine, hexamethylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 4,4'-diaminobenzophenone, 4,4'-diaminodiphenylamine, 2,2-bis (4-aminophenyl) ) Propane, 2- (3- Aminophenyl) -2- (4-aminophenyl) propane, 2- (4-aminophenyl) -2- (3-hydroxyphenyl) propane, 2- (4-aminophenyl) -2- (4-hydroxyphenyl) Propane, 1,4-bis [1- (4-aminophenyl) -1-methylethyl] benzene, 1,3-bis [1- (4-aminophenyl) -1-methylethyl] benzene, bis (2- Tri (cyclo) alkylamines such as dimethylaminoethyl) ether, bis (2-diethylaminoethyl) ether, N, N, N ′, N′-tetrakis (2-hydroxypropyl) ethylenediamine, tricyclohexylamine, aniline, N -Methylaniline, N, N-dimethylaniline, 2-methylaniline, 3-methylaniline, 4-methylaniline, 4-ni Roaniline, diphenylamine, triphenylamine, naphthylamine, aromatic amines such as 2,6-diisopropylaniline, polyethyleneimine, polyallylamine, 2-dimethylaminoethylacrylamide polymer, Nt-butoxycarbonyldi-n-octyl Amine, Nt-butoxycarbonyldi-n-nonylamine, Nt-butoxycarbonyldi-n-decylamine, Nt-butoxycarbonyldicyclohexylamine, Nt-butoxycarbonyl-1-adamantylamine, Nt -Butoxycarbonyl-N-methyl-1-adamantylamine, N, N-di-t-butoxycarbonyl-1-adamantylamine, N, N-di-t-butoxycarbonyl-N-methyl-1-adamantylamine, N -T-Butoxyca Bonyl-4,4′-diaminodiphenylmethane, N, N′-di-t-butoxycarbonylhexamethylenediamine, N, N, N ′, N′-tetra-t-butoxycarbonylhexamethylenediamine, N, N′- Di-t-butoxycarbonyl-1,7-diaminoheptane, N, N′-di-t-butoxycarbonyl-1,8-diaminooctane, N, N′-di-t-butoxycarbonyl-1,9-diaminononane N, N′-di-t-butoxycarbonyl-1,10-diaminodecane, N, N′-di-t-butoxycarbonyl-1,12-diaminododecane, N, N′-di-t-butoxycarbonyl -4,4'-diaminodiphenylmethane, Nt-butoxycarbonylbenzimidazole, Nt-butoxycarbonyl-2-methylbenzimidazole, N- -Butoxycarbonyl-2-phenylbenzimidazole, formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, propionamide, benzamide, pyrrolidone, N-methylpyrrolidone, Urea, methylurea, 1,1-dimethylurea, 1,3-dimethylurea, 1,1,3,3-tetramethylurea, 1,3-diphenylurea, tri-n-butylthiourea, imidazole, 4-methylimidazole Imidazoles such as 4-methyl-2-phenylimidazole, benzimidazole, 2-phenylbenzimidazole, pyridine, 2-methylpyridine, 4-methylpyridine, 2-ethylpyridine, 4-ethylpyridine, 2-phenylpyridine Pyridines such as gin, 4-phenylpyridine, 2-methyl-4-phenylpyridine, nicotine, nicotinic acid, nicotinamide, quinoline, 4-hydroxyquinoline, 8-oxyquinoline, acridine, piperazine, 1- (2- Piperazines such as (hydroxyethyl) piperazine, pyrazine, pyrazole, pyridazine, quinosaline, purine, pyrrolidine, piperidine, 3-piperidino-1,2-propanediol, morpholine, 4-methylmorpholine, 1,4-dimethylpiperazine, etc. be able to.

  Among these, 1,5-diazabicyclo [4.3.0] -5-nonene, 1,8-diazabicyclo [5.4.0] -7-undecene, 1,4-diazabicyclo [2.2.2] Octane, 4-dimethylaminopyridine, 1-naphthylamine, piperidine, 4-hydroxypiperidine, 2,2,6,6-tetramethyl-4-hydroxypiperidine, hexamethylenetetramine, imidazoles, hydroxypyridines, pyridines, 4 , 4'-diaminodiphenyl ether, triethylamine, tributylamine, tripentylamine, tri-n-octylamine, tris (ethylhexyl) amine, tridodecylamine, N, N-di-hydroxyethylaniline, N-hydroxyethyl-N- Nitrogen-containing basic compounds such as ethylaniline are particularly preferred. Yes.

The positive resist composition for immersion exposure of the present invention can further use a basic ammonium salt as the basic compound. Specific examples of the basic ammonium salt include the following compounds, but are not limited thereto.
Specifically, ammonium hydroxide, ammonium triflate, ammonium pentaflate, ammonium heptaflate, ammonium nonaflate, ammonium undecaflate, ammonium tridecaflate, ammonium pentadecaflate, ammonium methylcarboxylate, ammonium ethylcarboxylate, Ammonium propyl carboxylate, ammonium butyl carboxylate, ammonium heptyl carboxylate, ammonium hexyl carboxylate, ammonium octyl carboxylate, ammonium nonyl carboxylate, ammonium decyl carboxylate, ammonium undecyl carboxylate, ammonium dodecadecyl carboxylate, ammonium salt Decyl carboxylate, ammonium tetradecyl carboxylate, ammonium pentadecyl carboxylate, ammonium hexadecyl carboxylate, ammonium heptadecyl carboxylate, ammonium octadecyl carboxylate and the like.

Specific examples of ammonium hydroxide include tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, tetrapentylammonium hydroxide, tetrahexylammonium hydroxide, and tetraheptyl. Ammonium hydroxide, methyltrioctylammonium hydroxide, tetraoctylammonium hydroxide, didecyldimethylammonium hydroxide, tetrakisdecylammonium hydroxide, dodecyltrimethylammonium hydroxide, dodecylethyldimethylammonium hydroxide, didodecyldimethylammonium hydroxide, Tridodecylmethylammonium hydro Side, myristylmethylammonium hydroxide, dimethylditetradecylammonium hydroxide, hexadecyltrimethylammonium hydroxide, octadecyltrimethylammonium hydroxide, dimethyldioctadecylammonium hydroxide, tetraoctadecylammonium hydroxide, diallyldimethylammonium hydroxide, (2 -Chloroethyl) -trimethylammonium hydroxide, (2-bromoethyl) trimethylammonium hydroxide, (3-bromopropyl) -trimethylammonium hydroxide, (3-bromopropyl) triethylammonium hydroxide, glycidyltrimethylammonium hydroxide, choline hydroxy (R)-(+)-(3-chloro-2-hydro Cypropyl) trimethylammonium hydroxide, (S)-(−)-(3-chloro-2-hydroxypropyl) -trimethylammonium hydroxide, (3-chloro-2-hydroxypropyl) -trimethylammonium hydroxide, (2- Aminoethyl) -trimethylammonium hydroxide, hexamethonium hydroxide, decamethonium hydroxide, 1-azoniaproperan hydroxide, petronium hydroxide, 2-chloro-1,3-dimethyl-2
-Imidazolinium hydroxide, 3-ethyl-2-methyl-2-thiazolinium hydroxide, etc. can be mentioned.

The basic compound can be used alone or in combination of two or more, and it is more preferable to use two or more.
The amount of the basic compound used is generally 0.001 to 10% by mass, preferably 0.01 to 5% by mass, based on the solid content of the positive resist composition for immersion exposure, as a total amount.

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

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

In addition to the known surfactants described above, 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 ₆ F ₁₃ group and (poly (oxy) (Ethylene)) acrylate (or methacrylate) and (poly (oxypropylene)) acrylate (or methacrylate) copolymer, acrylate (or methacrylate) and (poly (oxyalkylene)) acrylate having C ₈ F ₁₇ groups (or Copolymer of acrylate (or methacrylate), (poly (oxyethylene)) acrylate (or methacrylate), and (poly (oxypropylene)) acrylate (or methacrylate) having a C ₈ F ₁₇ group List union It can be.

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

  These surfactants may be used alone or in several combinations.

  (E) The amount of the surfactant used is preferably 0.0001 to 2% by mass, more preferably 0.001 to 1% by mass, based on the total amount of the positive resist composition for immersion exposure (excluding the solvent). It is.

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

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

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

[9] (H) Carboxylic acid onium salt The positive resist composition for immersion exposure of the present invention may contain a carboxylic acid onium salt.
Examples of carboxylic acid onium salts in the present invention include carboxylic acid sulfonium salts, carboxylic acid iodonium salts, and carboxylic acid ammonium salts. In particular, the (H) carboxylic acid onium salt is preferably an iodonium salt or a sulfonium salt. Furthermore, in the carboxylic acid onium salt of the present invention, it is preferable that the carboxylate residue 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 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 suitably from 0.1 to 20% by weight, preferably from 0.5 to 10% by weight, more preferably from 1 to 7% by weight, based on the total solid content of the composition. %.

  In the positive resist composition for immersion exposure according to the present invention, if necessary, a dye, a plasticizer, a photosensitizer, and a compound that promotes solubility in a developer (for example, a phenol compound having a molecular weight of 1000 or less, An alicyclic or aliphatic compound having a carboxy group) or 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 carboxy 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.

[10] Pattern Forming Method The positive resist composition for immersion exposure according to the present invention is prepared by dissolving the above components in a predetermined organic solvent, preferably the mixed solvent, and applying the solution on a predetermined support as follows. Use.
That is, a positive resist composition for immersion exposure is formed on a substrate (eg, silicon / silicon dioxide coating) used for the manufacture of precision integrated circuit elements by an appropriate coating method such as a spinner or a coater. (Normally 50 to 500 nm).

After the coating, the resist applied by spin or baking is dried to form a resist film, and then exposed through a mask or the like for pattern formation, and exposed (immersion exposure) with actinic rays or radiation through an immersion liquid. For example, the exposure is performed in a state where the space between the resist film and the optical lens is filled with the immersion liquid. Although an exposure amount can be set suitably, it is 1-100 mJ / cm < ² > normally. After exposure, preferably spin or / and bake, develop and rinse to obtain a good pattern. The baking temperature is usually 30 to 300 ° C. From the above-mentioned PED point, it is better that the time from the exposure to the baking process is short.
Here, the actinic ray or radiation as exposure light is preferably far ultraviolet rays having a wavelength of 250 nm or less, more preferably 220 nm or less. Specific examples include KrF excimer laser (248 nm), ArF excimer laser (193 nm), F ₂ excimer laser (157 nm), and X-rays, and ArF excimer laser (193 nm) is particularly preferable.
The change in performance observed when the resist is applied to immersion exposure is considered to be derived from the fact that the resist surface is in contact with the immersion liquid.

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

The electrical resistance of water is desirably 18.3 MQcm or more, the TOC (organic substance concentration) is desirably 20 ppb or less, and deaeration treatment is desirably performed.
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 order to prevent the resist film from coming into direct contact with the immersion liquid between the resist film formed by the positive resist for immersion exposure of the present invention and the immersion liquid, an immersion liquid hardly soluble film (hereinafter referred to as “top coat”). May also be provided. The necessary functions for the top coat are suitability for application to the upper layer of the resist, radiation, especially transparency to 193 nm, and poor immersion liquid solubility. It is preferable that the top coat is not mixed with the resist and can be uniformly applied to the resist upper layer.
From the viewpoint of 193 nm transparency, the topcoat is preferably a polymer that does not contain an aromatic, and specifically, a hydrocarbon polymer, an acrylate polymer, a polymethacrylic acid, a polyacrylic acid, a polyvinyl ether, a silicon-containing polymer, And fluorine-containing polymers.
When peeling the top coat, a developer may be used, or a separate release agent may be used. As the release agent, a solvent having a small penetration into the resist is preferable. It is preferable that the peeling process can be performed with an alkali developer in that the peeling process can be performed simultaneously with the resist development process. From the viewpoint of peeling with an alkaline developer, the topcoat is preferably acidic, but may be neutral or alkaline from the viewpoint of non-intermixability with the resist.
The resolution is improved when there is no difference in refractive index between the topcoat and the immersion liquid. When the exposure light source is an ArF excimer laser (wavelength: 193 nm), it is preferable to use water as the immersion liquid, so that the top coat for ArF immersion exposure is close to the refractive index of water (1.44). Is preferred. A thin film is more preferable from the viewpoint of transparency and refractive index.

In the development process, a developer is used as follows. As a developer of a positive resist composition for immersion exposure, inorganic hydroxides such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, etc. Primary amines, 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, tetraethyl Alkaline aqueous solutions such as quaternary ammonium salts such as ammonium hydroxide and cyclic amines such as pyrrole and pihelidine can be used.
Furthermore, alcohols and surfactants can be added in appropriate amounts to the alkaline aqueous solution.
As the rinsing liquid, pure water can be used, and an appropriate amount of a surfactant can be added.
The alkali concentration of the alkali developer is usually from 0.1 to 20% by mass.
The pH of the alkali developer is usually from 10.0 to 15.0.

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

  Since the formed resist pattern preferably has no electrical conductivity, the metal content is preferably small, and the metal content is preferably 100 ppb or less, and more preferably 50 ppb or less.

  EXAMPLES Hereinafter, although an Example demonstrates this invention still in detail, it is not limited to this.

[Synthesis of Resin (1)]
2-adamantyl-2-propyl methacrylate, 3,5-dihydroxy-1-adamantyl methacrylate and norbornane lactone methacrylate were charged at a ratio of 40/20/40 (molar ratio), and propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether = 60. / 40 (mass ratio) was dissolved, and 450 g of a solution having a solid content concentration of 22 mass% was prepared. 1 mol% of a polymerization initiator V-601 (dimethyl 2,2′-azobis (2-methylpropionate) manufactured by Wako Pure Chemical Industries, Ltd. was added to this solution, and this was added at 100 ° C. over 6 hours in a nitrogen atmosphere. The solution was added dropwise to 50 g of a mixed solution of propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether = 60/40 (mass ratio), and the reaction solution was stirred for 2 hours after completion of the addition. cooled, hexane / crystallizer to a mixed medium 5L of ethyl acetate = 9/1 (mass ratio), collected by filtration white powder that precipitated was recovered resin (1) the desired product. ¹³ CNMR and polymeric acids Valence measurement to polymer composition ratio (2-adamantyl-2-propyl methacrylate / 3,5-dihydroxy-1-adamantyl methacrylate / norbornane Kuton methacrylate: a / b / c) was determined as 39/21/40 (molar ratio), and the weight average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement was 9700, and the degree of dispersion (Mw / Mn) Was 2.01.

  Similarly, the following resins (1) to (23) were obtained.

[Examples 1 to 20 and Comparative Examples 1 to 3]
<Resist preparation>
The components shown in Table 1 below were dissolved in a solvent to prepare a solution having a solid content of 10% by mass, and this was filtered through a polyethylene filter having a pore size of 0.1 μm to prepare a positive resist solution. The prepared positive resist solution was evaluated by the following method, and the results are shown in Table 1. In addition, about each component in Table 1, the ratio at the time of using multiple is a mass ratio.

  Hereinafter, symbols in Table 1 are as follows.

  The acid generator corresponds to that exemplified above.

N-1: N, N-dibutylaniline N-2: N, N-dipropylaniline N-3: N, N-dihydroxyethylaniline N-4: 2,4,5-triphenylimidazole N-5: tri Octylamine

W-1: Megafuck F176 (Dainippon Ink Chemical Co., Ltd.)
(Fluorine)
W-2: Megafuck R08 (Dainippon Ink Chemical Co., Ltd.)
(Fluorine and silicon)
W-3: Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.)
(Silicon)
W-4: Troisol S-366 (manufactured by Troy Chemical Co., Ltd.)

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

I-1: Lithocholic acid t-butyl I-2: Adamantanecarboxylic acid t-butyl P-1: Octanediol P-2: 1,8-octanoic acid dimethyl ester

[PEB temperature dependency evaluation]
An antireflection film (ARC25, manufactured by Brewer Science Co., Ltd.) was uniformly applied on the silicon substrate by a spin coater at 600 angstroms and dried at 190 ° C. for 240 seconds. Next, each positive resist solution was applied by a spin coater, and the wafer was heated and dried at 115 ° C. for 60 seconds to form a 0.25 μm resist film. The obtained resist film was exposed (dry exposure) using a 193 nm laser exposure / dissolution behavior analyzer VUVES-4500 (manufactured by RISOTEC Japan), and immediately after the exposure, it was heated on a hot plate at 120 ° C. for 60 seconds. The sample was developed with a 2.38 mass% tetramethylammonium hydroxide aqueous solution for 60 seconds and rinsed with pure water to obtain a sample wafer. About these, the exposure amount (sensitivity) D1 which a large pattern (pattern of 1.5 cm x 1.5 cm) resolves was calculated | required. Further, an exposure amount (sensitivity) D2 at which a large pattern is resolved was determined by performing the same operation except that the film was heated at 125 ° C. for 60 seconds immediately after exposure. The sensitivity fluctuation rate due to the change in post-heating temperature (PEB temperature) was determined by the following equation. The smaller the absolute value, the smaller the performance change due to post-heating temperature change.

  Sensitivity fluctuation rate (PEB temperature dependency) = {(D1-D2) / D1} × 100

  After a resist film is formed on a silicon substrate by the same method, exposure is performed using a liquid immersion exposure / dissolution behavior analyzer IMES-5500 (manufactured by RISOTEC Japan) (wet exposure), and the sensitivity fluctuation rate due to 193 nm exposure Asked.

[PED evaluation]
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 prepared positive resist composition for immersion exposure was applied thereon and baked at 120 ° C. for 60 seconds to form a 150 nm resist film. The wafer thus obtained was subjected to two-beam interference exposure (wet exposure) using the apparatus shown in FIG. 1 using pure water as the immersion liquid. The laser wavelength was 193 nm, and a prism that formed a 90 nm line and space pattern was used. Immediately after exposure, the resist pattern obtained by heating at 115 ° C. for 90 seconds, developing with an aqueous tetramethylammonium hydroxide solution (2.38 mass%) for 60 seconds, rinsing with pure water, and spin drying, and exposure Thereafter, the resist pattern obtained by standing for 30 minutes and then performing the same operation as described above was observed for pattern collapse performance and pattern profile using a scanning electron microscope (S-9260 manufactured by Hitachi).
Moreover, the same evaluation was performed also about the resist pattern obtained by exposing without passing through immersion liquid (normal exposure (dry exposure)), and performing the same operation as the above after that.
Pattern collapses are 90nm line and space patterns that are formed without falling, ◎ if they are partially collapsed, △ if they are more than half collapsed, △ if all are collapsed × It was.
In the apparatus shown in FIG. 1, 1 is a laser, 2 is an aperture, 3 is a shutter, 4, 5 and 6 are reflection mirrors, 7 is a condenser lens, 8 is a prism, 9 is an immersion liquid, 10 Denotes a wafer provided with an antireflection film and a resist film, and 11 denotes a wafer stage.

  From the above results, the positive resist composition for immersion exposure according to the present invention has a small PEB temperature dependency and little deterioration of pattern collapse due to the placement between exposure and PEB during immersion exposure, and good performance. It can be seen that

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

Explanation of symbols

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

Claims (4)

(A) a resin whose main chain is composed of only methacrylic repeating units and has an alicyclic hydrocarbon structure, whose solubility in an alkali developer is increased by the action of an acid, and
(B) A positive resist composition for immersion exposure, comprising a compound that generates an acid upon irradiation with actinic rays or radiation. The positive resist composition for immersion exposure according to claim 1, wherein the resin (A) has at least two different repeating units selected from repeating units represented by the following general formula (Ia): .
In the general formula (Ia), Ra represents a group having at least one of an alicyclic hydrocarbon structure and a lactone structure. The positive resist composition for immersion exposure according to claim 1, further comprising a compound represented by the following general formula (II):
In general formula (II),
X represents an alkylene group.
Q represents a single bond or a divalent linking group.
R ₁ and R ₂ are each independently a chlorine atom, bromine atom, iodine atom, hydroxyl group, alkoxy group, epoxy group, amino group, cyano group, acyl group, acyloxy group, lactone group, carboxylic acid group and aromatic group It represents a single group selected from the group consisting of or a combination of two or more groups.
n represents an integer of 1 to 5.
When a plurality of X and Q are present, they may be the same or different.   A pattern forming method comprising: forming a resist film from the positive resist composition according to claim 1; and subjecting the resist film to immersion exposure and development.