JP2006113246A - Protective film forming composition for liquid immersion exposure and pattern forming method using same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a protective film forming composition which can be stripped by using developing liquid in liquid immersion exposure and is capable of suppressing adverse effect on a resist film and forming an excellent resist pattern, and to provide a pattern forming method using the protective film forming composition. <P>SOLUTION: The protective film forming composition for liquid immersion exposure comprises: a resin (a) which is insoluble to water and is soluble to alkali developing liquid; and an ester type solvent (b) of which a hydrogen bonding component of SP value δh [(cal/cm<SP>3</SP>)<SP>1/2</SP>] falls into the range of 0<δh<8.5. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

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

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

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

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

Examples of apparatuses in which this effect is applied to transfer of a fine pattern of a semiconductor element include Patent Document 1 (Japanese Patent Publication No. 57-153433) and Patent Document 2 (Japanese Patent Laid-Open No. 7-220990). There is no discussion of resists suitable for exposure techniques.
Patent Document 3 (Japanese Patent Laid-Open No. 10-303114) points out that the refractive index control of the immersion liquid is important because the change in the refractive index of the immersion liquid causes deterioration of the projected image due to the wavefront aberration of the exposure machine. Disclosed is a water to which the temperature coefficient of the refractive index of the immersion liquid is controlled within a certain range and, as a suitable immersion liquid, an additive that lowers the surface tension or increases the surface activity is added. Has been. 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)), and the like. 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 product has not yet been seen in terms of environmental safety and refractive index. It has not been issued. From the degree of immersion effect and the degree of completeness of the resist, the immersion exposure technique is considered to be installed in the ArF exposure machine earliest.

Since the resist for KrF excimer laser (248 nm), an image forming method called chemical amplification has been used as an image forming method for a resist in order to compensate for sensitivity reduction due to light absorption. Taking a positive chemical amplification image forming method as an example, the acid generator in the exposed area is decomposed by exposure to generate an acid during exposure, and the generated acid is used as a reaction catalyst in post-exposure baking (PEB). In this image forming method, the alkali-insoluble group is changed to an alkali-soluble group, and the exposed portion is removed by alkali development.
In the immersion exposure, the resist film and the optical lens are filled with an immersion liquid (also referred to as an immersion liquid), and then exposed through a photomask to transfer the photomask pattern to the resist film. At this time, the immersion liquid may permeate the resist film to cause no image formation (Non-patent Document 3 (Nikkei Microdevice, April 2004 issue)). Further, it is expected that the exposure of the resist is expected because organic substances and the like are eluted from the resist film into the immersion liquid, and impurities are mixed in the immersion liquid and contaminate the lens and the exposure apparatus.

As a solution to avoid such problems, a protective film (hereinafter also referred to as “topcoat” or “overcoat”) is provided between the resist film and the lens so that the resist and water do not come into direct contact with each other. Methods are known (for example, Non-Patent Document 3 and Non-Patent Document 4 (resist technology for immersion exposure issued by ED Research)).
However, it is not known that sufficient performance is obtained as a material used for the top coat.

Japanese Patent Publication No.57-153433 JP-A-7-220990 JP-A-10-303114 Proc. SPIE, 2002, Vol. 4688, p. 11 J.Vac.Sci.Tecnol.B, 17 (1999) Nikkei Microdevices, April 2004 issue Published by ED Research Inc. Resist technology for immersion exposure

  An object of the present invention is to provide a protective film capable of protecting a resist film from an immersion liquid in pattern formation by immersion exposure and preventing elution of a resist film component into the immersion liquid. Is to provide a protective film that can be formed without adversely affecting the film, and to provide a protective film that can be peeled off with an alkaline developer in the development process, thereby enabling good pattern formation. It becomes.

  The present invention is a protective film forming composition for immersion exposure having the following constitution and a pattern forming method using the same, whereby the above-mentioned problems of the present invention are solved.

(1) (a) A resin that is insoluble in water and soluble in an alkaline developer and (b) a hydrogen bonding component δh [(cal / cm ³ ) ^1/2 ] of SP value is in the following range. Ester solvent 0 <δh <8.5
A protective film-forming composition for immersion exposure, comprising:

  (2) including a step of forming a resist film from the resist composition, forming a protective film on the resist film with the protective film-forming composition described in (1), subjecting the resist film to immersion exposure, and developing. A pattern forming method characterized by the above.

The preferred embodiments of the present invention will be further described below.
(3) The protective film-forming composition for immersion exposure according to (1), wherein the solvent has a boiling point of 130 ° C. or higher and 200 ° C. or lower.

  (4) The protective film forming composition for immersion exposure according to (1) or (3), further comprising a surfactant.

  (5) The protective film forming composition for immersion exposure according to (1), (3) or (4), wherein the metal content of the resin (a) is 5% by mass or less.

  (6) (b) The protective film forming composition for immersion exposure according to (1), (3), (4) or (5), wherein the solvent is represented by the following general formula (I): object.

In general formula (I),
R ₁ represents an organic group having 1 to 5 carbon atoms.
R ₂ represents an organic group having 3 to 20 carbon atoms.

  The protective film forming composition for immersion exposure according to the present invention is a protective film capable of protecting the resist film from the immersion liquid in pattern formation by immersion exposure and preventing the dissolution of the resist film component into the immersion liquid. In addition, a protective film that can be peeled off with an alkaline developer in the development step can be formed without adversely affecting the resist film, thereby enabling good pattern formation.

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

[1] (a) Resin that is insoluble in water and soluble in alkaline developer The protective film-forming composition for immersion exposure of the present invention contains a resin that is insoluble in water and soluble in alkaline developer. To do.
The protective film forming composition for immersion exposure of the present invention has a repeating unit derived from a monomer having an acid dissociation index pKa of 8 or more as a resin that is insoluble in water and soluble in an alkaline developer. And a resin soluble in an alkali developer (hereinafter also referred to as “resin (X)”).

The repeating unit contained in the resin (X) is a repeating unit formed by polymerization of a monomer having an acid dissociation index pKa of 8 or more.
The acid dissociation constant pKa is described in Chemical Handbook (II) (Revised 4th edition, 1993, edited by the Chemical Society of Japan, Maruzen Co., Ltd.). It can be measured at 25 ° C.

The monomer having a pKa of 8 or more is not particularly limited, and examples thereof include monomers having an acid group (alkali-soluble group) such as a phenolic hydroxyl group, a sulfonamide group, —COCH ₂ CO—, and a fluoroalcohol group. In particular, a monomer containing a fluoroalcohol group is preferred. The fluoroalcohol group is a fluoroalkyl group substituted with at least one hydroxyl group, preferably having 1 to 10 carbon atoms, more preferably having 1 to 5 carbon atoms. Specific examples of the fluoroalcohol group include, for example, —CF ₂ OH, —CH ₂ CF ₂ OH, —CH ₂ CF ₂ CF ₂ OH, —C (CF ₃ ) ₂ OH, —CF ₂ CF (CF ₃ ) OH. , —CH ₂ C (CF ₃ ) ₂ OH, and the like. Particularly preferred as the fluoroalcohol group is a hexafluoroisopropanol group.

  A monomer having a pKa of 8 or more may contain only one acid group or two or more acid groups. The repeating unit derived from the monomer preferably has two or more acid groups per repeating unit, more preferably 2 to 5 acid groups, and 2 to 3 acid groups. It is particularly preferred.

  The pKa of the monomer having a pKa of 8 or more is preferably 8 to 13. By containing the resin (X) containing a repeating unit derived from a monomer having a pKa of 8 or more, preferably 8 to 13, smooth solubility can be obtained even when a weakly basic alkaline developer is used.

  The resin (X) is preferably transparent in the exposure light source to be used because light reaches the resist film through the protective film during exposure. When used for ArF immersion exposure, the resin (X) preferably has no aromatic group from the viewpoint of transparency to ArF light.

  Although the preferable specific example of the repeating unit derived from the monomer whose pKa which resin (X) contains is 8 or more is shown below, it is not limited to these.

  Resin (X) can contain other repeating structural units in addition to the repeating structural unit derived from a monomer having a pKa of 8 or more. Examples of monomers that form other repeating structural units include addition polymerizable unsaturated bonds selected from, for example, acrylic esters, methacrylic esters, acrylamides, methacrylamides, allyl compounds, vinyl ethers, vinyl esters, and the like. And the like. In addition, any addition-polymerizable unsaturated compound that can be copolymerized with monomers corresponding to the above various repeating structural units may be copolymerized.

The resin (X) of the present invention includes a repeating unit derived from a monomer having a pKa of 8 or more, and thus is excellent in both insolubility in water and solubility in an alkali developer. In the resin (X), the content of repeating units derived from a monomer having a pKa of 8 or more is preferably 10 to 100 mol%, more preferably 20 to 100 mol%.

  Specific preferred examples of the resin (X) containing a repeating unit derived from a monomer having an acid dissociation index pKa of 8 or more are shown below, but are not limited thereto.

Since the resin (X) is insoluble in water, a protective film containing the resin (X) is interposed between the resist film and the immersion liquid, thereby preventing the immersion liquid from penetrating into the resist film. In addition, in order to prevent the resist component from eluting into the immersion liquid, an appropriate pattern can be obtained in pattern formation by immersion exposure.
In addition, since the resin (X) is soluble in the alkali developer, the protective film can be easily dissolved and removed by alkali development without providing a separate step for removing the protective film.

  Here, “insoluble in water” means that a solution obtained by dissolving a resin in a solvent is applied on a silicon wafer, dried, then immersed in pure water for 10 minutes at 23 ° C., and dried for film thickness measurement. The property that the film thickness does not decrease.

  In addition, “soluble in alkaline developer” means soluble in an alkaline developer used for development in resist pattern formation, and a solution in which a resin is dissolved in a solvent is applied onto a silicon wafer. After drying, a 2.38 mass% tetramethylammonium hydroxide aqueous solution was used for treatment at 23 ° C. for 30 seconds, rinsed with pure water for 30 seconds and dried, and then the film thickness was measured. The property which becomes.

Resin (X) 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 further dissolved in a solvent for dissolving the composition of the present invention such as propylene glycol monomethyl ether acetate described later, and then nitrogen, argon, etc. Polymerization is started using a commercially available radical initiator (such as an azo-based initiator or peroxide) under an inert gas atmosphere as necessary. 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.

Resin (X) is not limited to the radical polymerization, and can be synthesized by various methods. In addition to radical polymerization, it can also be synthesized by, for example, cationic polymerization, anionic polymerization, addition polymerization, cyclopolymerization, polyaddition, polycondensation, addition condensation and the like.
In addition, various commercially available resins can also be used.

  Each of 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 resin (X) is preferably 1,000 or more, more preferably 1,000 to 200,000, and even more preferably, as a polystyrene conversion value by a gas permeation chromatography (GPC) method. Is 3,000 to 20,000.
In the resin (X), the residual monomer is preferably 5% by mass or less from the viewpoint of preventing the eluate. More preferably, the residual monomer is 3% by mass or less.

  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.

  In the protective film-forming composition of the present invention, the blending amount of the resin (X) is preferably 60 to 100% by mass, more preferably 70 to 100% by mass, based on the total solid content of the protective film-forming composition. .

  The metal content of the resin (X) is preferably 5% by mass or less.

[2] (b) Ester solvent in which hydrogen bonding component δh [(cal / cm ³ ) ^1/2 ] of SP value is in the range of 0 <δh <8.5 The protective film for immersion exposure according to the present invention The forming composition is an ester solvent (hereinafter referred to as “solvent (b)”) in which the hydrogen bonding component δh [(cal / cm ³ ) ^1/2 ] of SP value is in the range of 0 <δh <8.5. Contain).
The SP value (solubility parameter) can be used to predict properties such as solvent solubility of the polymer compound, compatibility between the polymer compounds, and adhesion.
The hydrogen bonding component δh of SP value is a component that constitutes the SP value δ together with the dispersion force δd and the dipole-dipole interaction δp.
δ = δd + δp + δh
The hydrogen bonding component δh of the SP value is divided into a plurality of groups constituting the compound, and the following is obtained from the cohesive energy Eh [J / mol] and the molar volume Vi [cm ³ / mol] per mole of each group. (Dim-Krevelen method).
δh = √ (ΣEh / ΣVi)
For example, the Vi of CH ₃ is 21.55, the Vi of CH ₂ is 15.55, the Vi of C (═O) —O is 23.7, the Eh of C (═O) —O is 7000, and amyl acetate ( The hydrogen bonding component δh of CH ₃ —C (═O) —O—CH ₂ —CH ₂ —CH ₂ —CH ₂ —CH ₃ ) is calculated as follows.
δh = √ (7000 / (21.55 × 2 + 15.55 × 4 + 23.7 × 1) = 7.37
The values of Eh and Vi were obtained by measuring or calculating the latent heat of vaporization (the amount of heat absorbed by a substance when changing from a liquid state to a gaseous state at a constant temperature and pressure) and molecular volume (molar volume), respectively. Reference was made to a database, for example, the value of “Van Krevelen, D.W.,“ Properties of Polymers; Correlation with Chemical Structure, ”American Elsevier, NY (1972)”.

  The boiling point of the solvent (b) is 130 ° C. or higher and preferably 200 ° C. or lower.

  The solvent (b) is preferably represented by the following general formula (I).

In general formula (I),
R ₁ represents an organic group having 1 to 5 carbon atoms.
R ₂ represents an organic group having 3 to 20 carbon atoms.

The organic group having 1 to 5 carbon atoms of R ₁ is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, or an n-butyl group. , Isobutyl group, sec-butyl group, pentyl group, isopentyl group, neopentyl group, t-pentyl group and the like.

The organic group having 3 to 20 carbon atoms of R ₂ is preferably a linear or branched alkyl group having 3 to 20 carbon atoms. For example, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec- Butyl, pentyl, isopentyl, neopentyl, t-pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, A heptadecyl group, an octadecyl group, a nonadecyl group, an eicosyl group, etc. can be mentioned.

  Specific examples of the solvent (b) include, for example, propyl acetate, butyl acetate, amyl acetate, hexyl acetate, ethyl propionate, propyl propionate, butyl propionate, amyl propionate, hexyl propionate, methyl butyrate, ethyl butyrate, Examples thereof include propyl butyrate, butyl butyrate, amyl butyrate, hexyl butyrate and the like.

In the present invention, the solvent (b) may be used in combination with another solvent.
In that case, it is preferable that the usage-amount of another solvent shall be 90 mass% with respect to a solvent (b).

Examples of other solvents that can be used in combination include the following.
Benzene, toluene, ethylbenzene, amylbenzene, isopropylbenzene, hexane, heptane, octane, nonane, decane, cyclohexane, methylcyclohexane, p-menthane, decalin, xylene, cyclohexylbenzene, cyclohexene, cyclopentane, dipentene, naphthalene, Hydrocarbon solvents such as dimethylnaphthalene, cymene, tetralin, biphenyl, mesitylene;
-Halogenated hydrocarbon solvents such as methylene chloride, hexyl chloride, chlorobenzene, bromobenzene;
Alcohols such as amyl alcohol, isoamyl alcohol, butanol, hexanol, 3-heptanol, i-butyl alcohol, 2-ethylbutanol, 2-ethylhexanol, octanol, nonanol, neopentyl alcohol, cyclohexanol, tetrahydrofurfuryl alcohol;
Nitrogen-containing solvents such as acetonitrile, isopropanolamine, ethylhexylamine, N-ethylmorpholine, diisopropylamine, cyclohexylamine, di-n-butylamine, tetramethylethylenediamine, tripropylamine;
-Carboxylic acid solvents such as formic acid, acetic acid, butyric acid, isobutyric acid, itaconic acid, propionic acid;
-Acid anhydride solvents such as acetic anhydride, propionic anhydride, itaconic anhydride;

1,4-difluorobenzene, 1,1,2,2-tetrachlorodifluoroethane, tetrafluoropropanol, ethyl trifluoroacetoacetate, perfluoroheptane, hexafluoroisopropanol, perfluorobutylethanol, pentafluoropropanol, hexafluorobenzene Fluorine-based solvents such as perfluorobutyltetrahydrofuran, perfluoropolyethers and fluorophenols;
Others, anisole, dioxane, dioxolane, dibutyl ether, diacetone alcohol, ethylene glycol, diglycidyl ether, ethylene dichloride, γ-butyrolactone, ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 2-methoxyethyl acetate, Ethylene glycol monoethyl ether acetate, propylene glycol, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, toluene, ethyl acetate, N, N-dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, methoxybutanol, tetrahydrofuran, ethyl ethoxypropio , N, N-dimethylacetamide, ethyl-n- Ethyl ketone, diisobutyl ketone, methyl isobutyl ketone, methyl -n- butyl ketone, cyclohexanone, cyclopentanone, 2-heptanone, .gamma.-butyrolactone, methyl ethyl ketone.

  The protective film forming composition for immersion exposure according to the present invention preferably has a solid content concentration of 1 to 15% by mass, more preferably 3 to 10% by mass.

[3] Surfactant The protective film-forming composition of the present invention can further contain a surfactant. As the surfactant, any one of fluorine-based and / or silicon-based surfactant (fluorine-based surfactant, silicon-based surfactant, surfactant having both fluorine atom and silicon atom), or two or more kinds thereof It is more preferable to contain. By containing the above-mentioned surfactant, when using an exposure light source of 250 nm or less, particularly 220 nm or less, it contributes to performance improvement such as sensitivity, resolution, adhesion, and development defect suppression, and particularly to coating uniformity.

Examples of the fluorine-based and / or silicon-based surfactant include, for example, JP-A No. 62-36663, JP-A No. 61-226746, JP-A No. 61-226745, JP-A No. 62-170950, JP 63-34540 A, JP 7-230165 A, JP 8-62834 A, JP 9-54432 A, JP 9-5988 A, JP 2002-277862 A, US Patent Nos. 5,405,720, 5,360,692, 5,529,881, 5,296,330, 5,436,098, 5,576,143, 5,294,511, 5,824,451 Surfactant can be mentioned, The following commercially available surfactant can also be used as it is.

  Examples of commercially available surfactants that can be used include F-top EF301, EF303 (manufactured by Shin-Akita Kasei Co., Ltd.), Florard FC430, 431 (manufactured by Sumitomo 3M Co., Ltd.), MegaFuck F171, F173, F176, F189, R08 (Dainippon Ink Chemical Co., Ltd.), Surflon S-382, SC101, 102, 103, 104, 105, 106 (Asahi Glass Co., Ltd.), Troisol S-366 (Troy Chemical Co., Ltd.), etc. Fluorine type surfactant or silicon type surfactant can be mentioned. Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) can also be used as a silicon-based surfactant.

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

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

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

  These surfactants may be used alone or in several combinations.

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

[4] Protective film The protective film-forming composition for immersion exposure according to the present invention forms a protective film by, for example, being applied onto a resist film, and the immersion liquid penetrates into the resist film. It prevents elution of components into the immersion liquid. The means for coating is appropriately set according to the process to be applied, and is not particularly limited, and means such as spin coating can be used.

The protective film is preferably a thin film from the viewpoint that it is preferably transparent to the exposure light source, and is usually formed with a thickness of 1 nm to 300 nm, preferably 10 nm to 150 nm. Specifically, the film thickness is such that the exposure light transmittance of the film is preferably 50% to 80%, more preferably 60% to 70%. The exposure light transmittance can be adjusted by adjusting the polymerization component of the resin. For example, the transmittance of ArF light can be increased by reducing the amount of aromatic rings contained in the resin.
In order to prevent the immersion liquid and the lens from being contaminated by the eluate from the protective film, it is preferable that there is no eluate from the protective film. The protective film preferably has a low content of low molecular weight compounds (for example, compounds having a molecular weight of 1000 or less) from the viewpoint of preventing eluate.

From the viewpoint of affinity with the immersion liquid, the protective film preferably has a contact angle (23 ° C.) of the immersion liquid to the protective film of 50 to 80 degrees, more preferably 60 to 80 degrees. preferable. The contact angle can be adjusted to the above range by adjusting the amount of acid groups or controlling the hydrophilicity / hydrophobicity of the copolymer component.
The refractive index of the protective film is preferably close to the refractive index of the resist film from the viewpoint of resolution. The refractive index can be adjusted by controlling the components of the protective film forming composition, particularly the resin composition and the ratio of repeating units.
The protective film-forming composition is preferably one that can be applied uniformly when forming the protective film. The applicability (coating uniformity) can be improved by appropriately selecting the type of solvent, surfactant, etc. and other additives and adjusting the amount of addition.

  Moreover, it is preferable that the formed resist pattern does not have electroconductivity, but similarly, it is preferable that the protective composition for immersion exposure does not contain a metal. The amount of metal contained in the protective film-forming composition is preferably 100 ppb or less, more preferably 50 ppb or less. The amount of metal can be suppressed by usual purification such as improvement of the purity of the material used or filtration.

The protective film forming composition for immersion exposure is preferably not mixed with the resist film because it is formed on the resist film by coating.

[5] Pattern Forming Method The protective film forming composition for immersion exposure of the present invention is usually used by dissolving the above components in a solvent and applying the solution on a resist film on a substrate.
That is, the resist composition for immersion exposure is applied to an arbitrary thickness (usually 50 to 500 nm) by a suitable application method such as a spinner or a coater on a substrate used for manufacturing a precision integrated circuit element. At this time, it is also preferable to form a resist film after appropriately providing an antireflection film on the substrate. After application, the resist film is formed by drying by spinning or baking.
Further, similarly to the resist composition, a protective film forming composition for immersion exposure is applied onto the resist film using a spinner, a coater or the like, and dried by spinning or baking to form a protective film.

Next, exposure (immersion exposure) is performed through an immersion liquid through a mask for pattern formation. The exposure amount can be set as appropriate, but is usually 1 to 100 mJ / cm ² . After exposure, preferably, spinning or / and baking is performed, development and rinsing are performed to obtain a pattern. In the present invention, the protective film dissolves and peels in the developing solution in the developing step, so that it is not necessary to provide a separate peeling step.
Baking is preferably performed after exposure, and the baking temperature is usually 30 to 300 ° C. From the viewpoint of the change in the line width of the resist pattern due to fluctuations in the holding time (PED) from exposure to development processing, the time from exposure to baking is better.
Here, the exposure light is preferably far ultraviolet rays having a wavelength of 250 nm or less, more preferably 220 nm or less. Specific examples include KrF excimer laser (248 nm), ArF excimer laser (193 nm), F ₂ excimer laser (157 nm), X-rays, and the like.

  Examples of the substrate that can be used include a normal BareSi substrate, an SOG substrate, and a substrate having an antireflection film.

As the antireflection film, an inorganic film type such as titanium, titanium dioxide, titanium nitride, chromium oxide, carbon, α-silicon, and an organic film type made of a light absorber and a polymer material can be used. The former requires equipment such as a vacuum deposition apparatus, a CVD apparatus, and a sputtering apparatus for film formation. Examples of the organic antireflection film include a condensate of a diphenylamine derivative and a formaldehyde-modified melamine resin described in JP-B-7-69611, an alkali-soluble resin, a light absorber, and maleic anhydride copolymer described in US Pat. No. 5,294,680. A reaction product of a coalescence and a diamine type light absorbing agent, a resin binder described in JP-A-6-186863 and a methylolmelamine thermal crosslinking agent, a carboxylic acid group, an epoxy group and a light-absorbing group described in JP-A-6-118656. An acrylic resin-type antireflection film in the same molecule, a composition comprising methylol melamine and a benzophenone-based light absorber described in JP-A-8-7115, and a low-molecular light absorber added to a polyvinyl alcohol resin described in JP-A-8-179509 And the like.
Further, as the organic antireflection film, DUV30 series, DUV-40 series, ARC25, AC-2, AC-3, AR19, AR20, etc., manufactured by Brewer Science can be used.

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

When water is used as the immersion liquid, the surface tension of the water is decreased and the surface activity is increased, so that the resist layer on the wafer is not dissolved and the influence on the optical coating on the lower surface of the lens element can be ignored. An additive (liquid) may be added in a small proportion. The additive is preferably an aliphatic alcohol having a refractive index substantially equal to that of water, and specifically includes methyl alcohol, ethyl alcohol, isopropyl alcohol and the like. By adding an alcohol having a refractive index substantially equal to that of water, even if the alcohol component in water evaporates and the content concentration changes, an advantage that the change in the refractive index of the entire liquid can be extremely small can be obtained. On the other hand, when an opaque substance or impurities whose refractive index is significantly different from that of water are mixed with respect to 193 nm light, the optical image projected on the resist is distorted. Therefore, distilled water is preferable as the water to be used. Further, pure water filtered through an ion exchange filter or the like may be used.
The electrical resistance of water is desirably 18.3 M ohm · cm or more, and the TOC (organic concentration) is desirably 20 ppb or less. Moreover, it is desirable to have deaerated.

Examples of the alkaline developer used in the development step include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia and other primary amines, ethylamine, n-propylamine and other 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, tetraethylammonium hydroxide and the like Alkaline aqueous solutions such as quaternary ammonium salts, cyclic amines such as pyrrole and pihelidine can be used.
Furthermore, alcohols and surfactants can be added in appropriate amounts to the alkaline aqueous solution.

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.
As the rinsing liquid, pure water or an appropriate amount of a surfactant added to pure water can be used.

  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.

  In immersion exposure using the protective film of the present invention, the resist is not particularly limited, and can be arbitrarily selected from those usually used, and may be either positive type or negative type.

  As the resist, positive type and negative type resists having sufficient characteristics that can be applied to recent ultra-fine processing can be suitably used. In the present invention, a chemically amplified resist, and further a positive type resist is preferably used. Can do.

  Typical examples of the chemically amplified resist include those using a so-called acid generator that generates an acid by active energy rays such as light. For example, as the negative chemically amplified resist, a three-component system of a base polymer, a photoacid generator, and a crosslinking agent is usually used. At the time of resist exposure, the acid generated by light irradiation causes a crosslinking reaction in the exposed portion, and acts to reduce the solubility in the developer. On the other hand, a positive chemically amplified resist is usually a two-component system including a base polymer having a site blocked with a protective group having a dissolution inhibiting function and a photoacid generator, a base polymer, an acid generator, There are some three-component dissolution inhibitors. Then, at the time of resist exposure, in the exposed portion, the acid generated by light irradiation acts to remove the protective group of the polymer and increase the solubility in the developer.

  When the exposure light source is an ArF excimer laser (wavelength: 193 nm), a two-component system containing a resin that is solubilized in an alkaline developer by the action of an acid and a photoacid generator is preferred. In particular, the resin that is solubilized in the alkaline developer by the action of an acid is preferably an acrylic or methacrylic resin having a monocyclic or polycyclic alicyclic hydrocarbon structure, and has a lactone residue or an adamantane residue. Is more preferable.

  In addition, since it is preferable that the formed resist pattern does not have electroconductivity, it is preferable that a resist does not contain a metal. The amount of metal contained is preferably 100 ppb or less, more preferably 50 ppb or less. The amount of metal can be suppressed by usual purification such as improvement of the purity of the material used or filtration.

  Hereinafter, the chemically amplified resist composition for immersion process that is preferably used in the present invention will be described.

(A) Resin that decomposes by the action of an acid and increases its solubility in an alkaline developer The resin used in the chemically amplified resist composition for the immersion process of the present invention is decomposed by the action of an acid and has a solubility in an alkaline developer. Is a resin (acid-decomposable resin) that increases in the main chain or side chain of the resin, or both of the main chain and side chain by the action of an acid to generate an alkali-soluble group (hereinafter referred to as “acid”). A resin having a degradable group).
Examples of the alkali-soluble group include a carboxyl group, a hydroxyl group, and a sulfonic acid group.
A preferred group that can be decomposed with an acid is a group in which the hydrogen atom of the —COOH group is substituted with a group capable of leaving with an acid.
The acid-decomposable group is preferably a cumyl ester group, an enol ester group, an acetal ester group, a tertiary alkyl ester group or the like. More preferably, it is a tertiary alkyl ester group.

  In addition, the resin that is decomposed by the action of an acid used in the chemically amplified resist composition for immersion process of the present invention and has increased solubility in an alkaline developer is a resin having a monocyclic or polycyclic alicyclic hydrocarbon structure. It is preferable that

  The monocyclic or polycyclic alicyclic hydrocarbon structure includes a repeating unit having a partial structure containing an alicyclic hydrocarbon represented by the following general formula (pI) to general formula (pVI) and a general formula (II-AB). In the repeating unit represented by

  Resin that has a monocyclic or polycyclic alicyclic hydrocarbon structure contained in the chemically amplified resist composition for immersion process of the present invention, decomposes by the action of an acid, and has increased solubility in an alkaline developer (hereinafter referred to as “resin”) The alicyclic hydrocarbon-based acid-decomposable resin) is a repeating unit having a partial structure containing an alicyclic hydrocarbon represented by the following general formula (pI) to general formula (pVI) and the following general formula: A resin having at least one selected from the group of repeating units represented by (II-AB) is 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 having 1 to 4 carbon atoms or an alicyclic hydrocarbon group. However, at least one of R _{12 to} R ₁₄ , or any of R ₁₅ and R ₁₆ represents an alicyclic hydrocarbon group.
R _{17 to} R ₂₁ each independently represents a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or an alicyclic hydrocarbon group. However, at least one of R _{17 to} R ₂₁ represents an alicyclic hydrocarbon group. Further, either R ₁₉ or R ₂₁ represents a linear or branched alkyl group or alicyclic hydrocarbon group having 1 to 4 carbon atoms.
R _{22 to} R ₂₅ each independently represents a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or an alicyclic hydrocarbon group. However, at least one of R _{22 to} R ₂₅ represents an alicyclic hydrocarbon group. R ₂₃ and R ₂₄ may be bonded to each other to form a ring.

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

  In addition, examples of the substituent that each alkyl group may have include an alkoxy group having 1 to 4 carbon atoms, a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), acyl group, acyloxy group, cyano. Group, hydroxyl group, carboxy group, alkoxycarbonyl group, nitro group and the like.

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

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

  Examples of the substituent for these alicyclic hydrocarbon groups include an alkyl group, a halogen atom, a hydroxyl group, an alkoxy group, a carboxyl group, and an alkoxycarbonyl group. The alkyl group is preferably a lower alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, or a butyl group, and more preferably 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.

  The structures represented by the general formulas (pI) to (pVI) in the resin can be used for protecting alkali-soluble groups. Examples of the alkali-soluble group include various groups known in this technical field.

  Specific examples include a carboxylic acid group, a sulfonic acid group, a phenol group, and a thiol group, and a carboxylic acid group and a sulfonic acid group are preferable.

  As the alkali-soluble group protected by the structure represented by the general formulas (pI) to (pVI) in the above resin, the hydrogen atom of the carboxyl group is preferably substituted with the structure represented by the general formula (pI) to (pVI). Structure.

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

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

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

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

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

Next, the repeating unit represented by formula (II-AB) will be described.
The repeating unit represented by formula (II-AB) is as follows.

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

  The general formula (II-AB) is more preferably the following general formula (II-A) or general formula (II-B).

In formulas (II-A) and (II-B):
R ₁₃ ′ to R ₁₆ ′ each independently represents a hydrogen atom, a halogen atom, a cyano group, —COOH, —COOR ₅ , a group that decomposes by the action of an acid, —C (═O) —XA′—R. ₁₇ ′ represents an alkyl group or a cyclic hydrocarbon group.
Wherein, R ₅ represents an alkyl group, cyclic hydrocarbon group, or -Y group shown below.
X represents an oxygen atom, a sulfur atom, -NH -, - NHSO ₂ - or an -NHSO ₂ NH-.
A ′ represents a single bond or a divalent linking group.
R ₁₇ ′ represents —COOH, —COOR ₅ , —CN, a hydroxyl group, an alkoxy group, —CO—NH—R ₆ , —CO—NH—SO ₂ —R ₆ or the following —Y group.
R ₆ represents an alkyl group or a cyclic hydrocarbon group.
Further, at least two of R ₁₃ ′ to R ₁₆ ′ may be bonded to form a ring.
n represents 0 or 1.

  The -Y group;

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

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

The alkyl group for R ₁₁ ′ and R ₁₂ ′ is preferably a linear or branched alkyl group having 1 to 10 carbon atoms, more preferably a linear or branched alkyl group having 1 to 6 carbon atoms. More preferred are methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group and t-butyl group.

  Examples of the further substituent in the alkyl group include a hydroxyl group, a halogen atom, a carboxyl group, an alkoxy group, an acyl group, a cyano group, and an acyloxy group. Examples of the halogen atom include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom. Examples of the alkoxy group include those having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, and a butoxy group. Examples of the acyl group include a formyl group and an acetyl group, and examples of the acyloxy group include an acetoxy group.

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

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

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

  Among the repeating units having the bridged alicyclic hydrocarbon, the repeating unit represented by the general formula (II-A) or (II-B) is more preferable.

In the alicyclic hydrocarbon-based acid-decomposable resin according to the present invention, the acid-decomposable group may be contained in the aforementioned —C (═O) —XA′—R ₁₇ ′, AB) may be included as a substituent for Z ′.

The structure of the acid-decomposable group is represented by —C (═O) —X ₁ —R ₀ .
In the formula, R ₀ is a tertiary alkyl group such as t-butyl group or t-amyl group, isobornyl group, 1-ethoxyethyl group, 1-butoxyethyl group, 1-isobutoxyethyl group, 1-cyclohexyloxy. 1-alkoxyethyl group such as ethyl group, 1-methoxymethyl group, alkoxymethyl group such as 1-ethoxymethyl group, 3-oxoalkyl group, tetrahydropyranyl group, tetrahydrofuranyl group, trialkylsilyl ester group, 3- An oxocyclohexyl ester group, a 2-methyl-2-adamantyl group, a mevalonic lactone residue and the like can be mentioned. X ₁ has the same meaning as X above.

Examples of the halogen atom in R ₁₃ ′ to R ₁₆ ′ include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom.

The alkyl group in R ₅ , R ₆ , R ₁₃ ′ to R ₁₆ ′, R ₂₁ ′ to R ₃₀ ′ is preferably a linear or branched alkyl group having 1 to 10 carbon atoms, more preferably carbon. A linear or branched alkyl group of several to six, more preferably a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, or a t-butyl group. is there.

Examples of the cyclic hydrocarbon group in R ₅ , R ₆ and R ₁₃ ′ to R ₁₆ ′ include a cyclic alkyl group and a bridged hydrocarbon group, such as a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, an adamantyl group, 2- List methyl-2-adamantyl group, norbornyl group, boronyl group, isobornyl group, tricyclodecanyl group, dicyclopentenyl group, nobornane epoxy group, menthyl group, isomenthyl group, neomenthyl group, tetracyclododecanyl group, etc. Can do.

Examples of the ring formed by combining at least two of R ₁₃ ′ to R ₁₆ ′ include rings having 5 to 12 carbon atoms such as cyclopentene, cyclohexene, cycloheptane, and cyclooctane.

Examples of the alkoxy group for R ₁₇ ′ include those having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, and a butoxy group.

  Examples of further substituents in the alkyl group, cyclic hydrocarbon group, and alkoxy group include a hydroxyl group, a halogen atom, a carboxyl group, an alkoxy group, an acyl group, a cyano group, an acyloxy group, an alkyl group, and a cyclic hydrocarbon group. Can do. Examples of the halogen atom include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom. Examples of the alkoxy group include those having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group and a butoxy group. Examples of the acyl group include a formyl group and an acetyl group. Examples thereof include an acetoxy group.

  Examples of the alkyl group and cyclic hydrocarbon group include those listed above.

The divalent linking group for A ′ is one or two selected from the group consisting of an alkylene group, an ether group, a thioether group, a carbonyl group, an ester group, an amide group, a sulfonamide group, a urethane group, and a urea group. Combinations of the above groups can be mentioned.

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

Various substituents of R ₁₃ ′ to R ₁₆ ′ in the general formula (II-A) or the general formula (II-B) are atomic groups for forming an alicyclic structure in the general formula (II-AB). Or it becomes a substituent of atomic group Z for forming a bridged alicyclic structure.

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

  The alicyclic hydrocarbon-based acid-decomposable resin of the present invention preferably has a lactone group, and more preferably any of the following general formulas (Lc) and general formulas (III-1) to (III-5) below. It has a repeating unit having a group having a lactone structure represented, 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 represent a hydrogen atom or an alkyl group. m and n each independently represents 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.

As the repeating unit having a group having a lactone structure represented by the general formula (Lc) or any one of the general formulas (III-1) to (III-5), the above general formula (II-A) or (II- B) wherein at least one of R ₁₃ ′ to R ₁₆ ′ has a group represented by general formula (Lc) or general formula (III-1) to (III-5) (for example, R in —COOR ₅ ) ₅ represents a group represented by the general formula (Lc) or the general formulas (III-1) to (III-5)), or a repeating unit represented by the following general formula (AI).

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

Examples of the halogen atom for R _b0 include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R _b0 is preferably a hydrogen atom.

  A ′ represents a single bond, an ether group, an ester group, a carbonyl group, an alkylene group, or a divalent group obtained by combining these.

B ₂ represents a group represented by 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 alicyclic hydrocarbon-based acid-decomposable resin of the present invention may have a repeating unit having a group represented by the following general formula (IV).

In the general formula _{(IV), R 2 c~R 4} c represents a hydrogen atom or a hydroxyl group independently. However, at least one of R ₂ c to R ₄ c 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.

As the repeating unit having a group represented by the general formula (IV), at least one of R ₁₃ ′ to R ₁₆ ′ in the general formula (II-A) or (II-B) is represented by the general formula (IV ) (For example, R _{5 in} —COOR ₅ represents a group represented by the general formula (IV)), or a repeating unit represented by the following general formula (AII). it can.

In general formula (AII), R ₁ c represents a hydrogen atom or a methyl group.
R ₂ c to R ₄ c each independently represents a hydrogen atom or a hydroxyl group. However, at least one of R ₂ c to R ₄ c represents a hydroxyl group. _{Two of} R ₂ c to R ₄ c are preferably hydroxyl groups.

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

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

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

  Examples of the repeating unit represented by the general formula (V) include, but are not limited to, the following specific examples.

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

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

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

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

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

  In alicyclic hydrocarbon-based acid-decomposable resins, the molar ratio of each repeating structural unit is the resist's dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and resolution that is a general required performance of resists. In order to adjust heat resistance, sensitivity, etc., it is set appropriately.

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

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

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

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

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

In particular, the content of the above-described repeating unit having a group having a lactone structure and the repeating unit having a group represented by the general formula (IV) (hydroxyadamantane structure) is as follows.
The total number of moles of the repeating structural unit having a partial structure containing an alicyclic hydrocarbon represented by the general formulas (pI) to (pVI) and the repeating unit represented by the general formula (II-AB) for,
The content of the repeating unit having a group having a lactone structure is preferably 1 to 70 mol%, more preferably 10 to 70 mol%,
Content of the repeating unit which has group represented by general formula (IV) becomes like this. Preferably it is 1-70 mol%, More preferably, it is 1-50 mol%.

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

  The alicyclic hydrocarbon-based acid-decomposable resin used in the present invention can be synthesized according to a conventional method (for example, radical polymerization). For example, as a general synthesis method, 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.

  Each of 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 alicyclic hydrocarbon-based acid-decomposable resin of the present invention is preferably 1,000 to 200,000, more preferably 3000 to 20000 as a polystyrene converted value by the 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 chemically amplified resist composition for immersion process according to the present invention, the blending amount of the alicyclic hydrocarbon-based acid-decomposable resin is preferably 40 to 99.99% by mass, more preferably 50 to 50%, based on the total solid content of the resist. It is 99.97 mass%.

(B) Compound that generates acid upon irradiation with actinic ray or radiation Compound that generates acid upon irradiation with actinic ray or radiation (hereinafter referred to as “acid generation”) used in the chemically amplified resist composition for immersion process of the present invention. The “agent” 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 compounds among the acid generators include compounds represented by the following general formulas (ZI), (ZII), and (ZIII).

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

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

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

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

  More preferable (ZI) components include compounds (ZI-1), (ZI-2), and (ZI-3) described below.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

  Examples of the sulfonylimide anion include saccharin anion.

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

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

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

Next, the compound (ZI-2) will be described.
Compound (ZI-2) is a compound in the case where R _{201 to} R ₂₀₃ in formula (ZI) each independently represents an organic group 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 alkoxy group having 1 to 5 carbon atoms (methoxy group, ethoxy group, propoxy group, butoxy group, pentoxy group).

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

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

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

Any two or more of R _{1c to} R _5c , R _6c and R _7c , and R _x and R _y may be bonded to each other to form a ring structure, and this ring structure includes an oxygen atom and a sulfur atom. , An ester bond and an amide bond may be included.

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 .

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.

Examples of the group formed by combining any two or more of R _{1c to} R _5c , R _6c and R _7c , and R _x and R _y include a butylene group and a pentylene group.

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

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

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

The cycloalkyl group as R ₂₀₄ to R ₂₀₇ is preferably a cycloalkyl group having 3 to 10 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).

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

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

R ₂₀₆ , R ₂₀₇ and R _{208 each} represents an alkyl group, a cycloalkyl group or an aryl group.
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 chemically amplified resist composition for immersion process 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%.

(C) Solvent The chemical amplification resist composition for immersion process of the present invention is used by dissolving each component in a predetermined solvent.
Examples of solvents 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- Examples include dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, methoxybutanol, and tetrahydrofuran. Rukoto can.

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 a 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 (weight) 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 still 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.

  In the chemically amplified resist composition for immersion process of the present invention, the content of the solvent is preferably 80 to 98% by mass, more preferably 85 to 95% by mass in the total composition. .

(D) Fluorine and / or silicon-based surfactant The chemically amplified resist composition for immersion process of the present invention has a concentration of 1000 ppm or more, preferably 2000 ppm or more, more preferably 3000 ppm, based on the total amount of the composition. Fluorine-based and / or silicon-based surfactants (fluorine-based surfactants, silicon-based surfactants, surfactants having both fluorine and silicon atoms) at the above concentrations, particularly preferably at a concentration of 3000 to 10,000 ppm. It is preferable to contain.

The surfactant is preferable from the viewpoint of good sensitivity, good resolution, improved adhesion, reduction of development defects, and the like when using an exposure light source of 193 nm.
Examples of the fluorine-based and / or silicon-based surfactant include, for example, JP-A No. 62-36663, JP-A No. 61-226746, JP-A No. 61-226745, JP-A No. 62-170950, JP 63-34540 A, JP 7-230165 A, JP 8-62834 A, JP 9-54432 A, JP 9-5988 A, JP 2002-277862 A, US Patent Nos. 5,405,720, 5,360,692, 5,529,881, 5,296,330, 5,436,098, 5,576,143, 5,294,511, 5,824,451 Surfactant can be mentioned, The following commercially available surfactant can also be used as it is.
Examples of commercially available surfactants that can be used include F-top EF301, EF303 (manufactured by Shin-Akita Kasei Co., Ltd.), Florard FC430, 431 (manufactured by Sumitomo 3M Co., Ltd.), MegaFuck F171, F173, F176, F189, R08 (Dainippon Ink Chemical Co., Ltd.), Surflon S-382, SC101, 102, 103, 104, 105, 106 (Asahi Glass Co., Ltd.), Troisol S-366 (Troy Chemical Co., Ltd.), etc. Fluorine type surfactant or silicon type surfactant can be mentioned. Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) can also be used as a silicon-based surfactant.

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

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

  These surfactants may be used alone or in several combinations.

In the present invention, other surfactants other than fluorine-based and / or silicon-based surfactants may be used in combination.
Examples of other surfactants other than fluorine and / or silicon surfactants include polyoxyethylene such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, polyoxyethylene oleyl ether, and the like. Alkyl ethers, polyoxyethylene alkyl allyl ethers such as polyoxyethylene octylphenol ether, polyoxyethylene nonylphenol ether, polyoxyethylene / polyoxypropylene block copolymers, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate Sorbitan fatty acid esters such as sorbitan monooleate, sorbitan trioleate, sorbitan tristearate, polyoxyethylene Nonionics such as polyoxyethylene sorbitan fatty acid esters such as sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, polyoxyethylene sorbitan tristearate Surfactant etc. can be mentioned.

(E) Basic compound It is preferable that the chemically amplified resist composition for immersion process of the present invention 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 chemically amplified resist composition for immersion process that can control the diffusion phenomenon in the resist film of the acid generated from the acid generator by exposure is improved, In addition, the resolution as a resist is further improved, and a change in the line width of the resist pattern due to fluctuations in the holding time (PED) from exposure to development processing can be suppressed, 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, phenylene Diamine, naphthylamine, diaminonaphthalene, pyrrole derivatives (eg, pyrrole, 2H-pyrrole, 1-methylpyrrole, 2,4-dimethylpyrrole, 2,5-dimethylpyrrole, N-methylpyrrole, etc.), oxazole derivatives (eg, oxazole, isopropanol) Oxazole etc.), thiazole derivatives (eg thiazole, isothiazole etc.), imidazole derivatives (eg imidazole, 4-methylimidazole, 4-methyl-2-phenylimidazole etc.), pyrazole derivatives, furazane derivatives, pyro 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, methyl) Pyridine, ethylpyridine, propylpyridine, butylpyridine, 4- (1-butylpentyl) pyridine, dimethylpyridine, trimethylpyridine, triethylpyridine, phenylpyridine, 3-methyl-2-phenylpyridine, 4-tert-butylpyridine, diphenyl Pyridine, benzylpyridine, methoxypyridine, butoxypyridine, dimethoxypyridine, 1-methyl-2-pyridone, 4-pyrrolidinopyridine, 1-methyl-4-phenylpyridine, 2- (1-ethyl) Ropyl) 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 derivative, adenine derivative, adenosine derivative, guanine derivative, guanosine derivative, uranium Examples include syl derivatives and uridine derivatives.

  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 imide derivatives include phthalimide, succinimide, maleimide and the like.

  Specific examples of nitrogen-containing compounds 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, Nt 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 , 4-phenylpyridine, 2-methyl-4-phenylpyridine, nicotine, nicotinic acid, nicotinamide, quinoline, 4-hydroxyquinoline, 8-oxyquinoline, acridine and other pyridines, 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 chemically amplified resist composition for immersion process 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, methyl trioctyl ammonium hydroxide, tetraoctyl ammonium hydroxide, didecyl dimethyl ammonium hydroxide, tetrakisdecyl ammonium hydroxide, dodecyl trimethyl ammonium hydroxide, dodecyl ethyl dimethyl ammonium hydroxide, didodecyl dimethyl ammonium 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-azoniapropellan hydroxide, petronium hydroxide, 2-chloro-1,3-dimethyl-2-imidazolinium hydroxy And 3-ethyl-2-methyl-2-thiazolinium hydroxide.

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 chemically amplified resist composition for immersion process, as a total amount.

(F) 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 chemically amplified resist composition for immersion process of the present invention is decomposed by the action of an acid. It is preferable to contain 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.
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 resin as the component (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 solid content of the chemically amplified resist composition for immersion process.

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

(G) Alkali-soluble resin The chemically amplified resist composition for an immersion process 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 carboxyl group as an alkali-soluble group can also be used. The resin having a carboxyl group preferably has a monocyclic or polycyclic alicyclic hydrocarbon group in order to improve dry etching resistance. Specifically, a methacrylic acid ester and (meth) acrylic acid copolymer having an alicyclic hydrocarbon structure that does not exhibit acid decomposability, or a (meth) acrylic acid ester having an alicyclic hydrocarbon group having a carboxyl group at the terminal And the like.
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.

(H) Carboxylic acid onium salt The chemical amplification resist composition for immersion process 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, as the carboxylic acid onium salt, an iodonium salt and a sulfonium salt are preferable. 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. %.

Other Additives The chemical amplification resist composition for immersion process according to the present invention may further include a dye, a plasticizer, a photosensitizer, and a compound that promotes solubility in a developer (for example, a molecular weight of 1000). The following phenol compounds, alicyclic or aliphatic compounds having a carboxyl group, and the like can be contained.

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

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

Synthesis Example 1 (Synthesis of Resin (A-15))
43.6 g (0.1 mol) of 4- [bis (trifluoromethyl) -hydroxymethyl] styrene is dissolved in 250 ml of propylene glycol monomethyl ether, and 2,2′-azobis (2,4-dimethylvalero) is used as a polymerization initiator. Nitrile) (Wako Pure Chemical Industries, Ltd .; trade name V-65) 0.25 g was added. This solution was stirred at 70 under nitrogen flow for 4 hours.
Thereafter, the reaction solution was charged into 1 L of hexane with vigorous stirring. The precipitated resin was washed with ion exchange water, filtered, and dried under vacuum to obtain 40 g of a white resin. It was confirmed by GPC measurement that the weight average molecular weight (polystyrene standard) was 7,000.
Similarly, the resin (A-29) used in Examples and Comparative Examples was synthesized.
The weight average molecular weight of the resin (A-29) is 18000, and the repeating unit molar ratio is 95/5 in order from the left.
Table 1 below shows the metal impurity content (unit: ppb) in the resins (A-15) and (A-29). In addition, content of the metal impurity was measured about seven elements, Na, K, Ca, Fe, Cu, Mg, and Mn, using the polarization | polarized-light Zeeman atomic absorption spectrophotometer (the Hitachi make, Z-9000).

Examples 1-6 and Comparative Examples 1-3
<Solubility test of resist film>
A resist composition described in Table 2 below was applied on a silicon wafer and baked at 115 ° C. for 60 seconds to form a resist film having a thickness of 200 nm. The obtained resist film was immersed in a coating solvent for the protective film forming composition for immersion exposure described in Table 2 for 60 seconds, and the dissolution rate in the coating solvent was calculated from the change in film thickness. A sample having a dissolution rate of less than 10 A / second was evaluated as ◯, and a sample having a dissolution rate of 10 A / second or more was evaluated as ×. The results are shown in Table 2.

  The resist composition described in Table 2 is as follows.

  PR1: Resist composition described in Example 1 of JP-A-2000-275845, that is, the following resin P-1 (weight average molecular weight of about 10,000), acid generator (triphenylsulfonium perfluorobutanesulfonate (Midori Chemical) “TPS-109”))) 0.2 parts, 0.015 parts of a basic compound (2,6-diisopropylaniline), and a solvent (47.5 parts of propylene glycol monomethyl ether acetate and 2.5 parts of γ-butyrolactone).

PR2: Resist composition described in Example 1 of JP-A No. 2003-167347, that is, 100 parts by mass of the following resin P-2 (weight average molecular weight 10,000), acid generator component (triphenylsulfonimnonafluorobutanesulfonate) ) A resist composition containing 2 parts by mass, 0.2 parts by mass of a basic compound (triethanolamine), and an organic solvent (750 parts by mass of propylene glycol monomethyl ether acetate / 30 parts by mass of γ-butyrolactone).

  PR3: Resist composition described in Example 1 of JP 2002-12622 A, that is, 80 parts by weight of the following resin P-3, 1 part by weight of an acid generator (PAG1), 0.078 of a basic compound (TBA: tributylamine) A resist composition containing 480 parts by weight of a solvent (PGMEA: propylene glycol methyl ether acetate).

  From Table 2, it is clear that the resist film is hardly dissolved in the solvent of the present invention, and that the protective film can be formed without adversely affecting the resist film by the protective film forming composition containing the solvent of the present invention.

<Image formation evaluation>
The components shown in Table 3 below are dissolved in a solvent to prepare a solution having a solid content of 10% by mass, which is filtered through a 0.1 μm polyethylene filter, and the protective film forming composition for immersion exposure shown in Table 3 Was prepared.
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. A resist composition (PR-1) was applied thereon, and baked at 115 ° C. for 60 seconds to form a resist film having a thickness of 200 nm. Furthermore, the protective film formation composition for immersion exposure shown in Table 3 was applied thereon, and baked at 60 ° C. for 60 seconds to form a protective film having a thickness of 40 nm.

The wafer thus obtained was subjected to two-beam interference exposure with the apparatus of FIG. 1 using water as the immersion liquid. The laser wavelength was 193 nm. After heating at 115 ° C. for 60 seconds, development was performed with a tetramethylammonium hydroxide aqueous solution (2.38 mass%) for 60 seconds, rinsing with pure water, and spin drying to obtain a resist pattern.
The obtained pattern was observed with a scanning electron microscope (S-9260, manufactured by Hitachi). A pattern in which a 65 nm line and space pattern was formed was marked with ◯, and a pattern with no pattern was marked with x. The results are shown in Table 3.
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, a resist film and a protective film, and 11 denotes a wafer stage.

Abbreviations in Table 3 are as follows.
W-1: MegaFuck F176 (Fluorine surfactant manufactured by Dainippon Ink and Chemicals, Inc.)
W-2: Megafuck R08 (Dainippon Ink Chemical Co., Ltd.) (fluorine and silicon)

  From Table 3, it is clear that a good resist pattern can be formed in immersion exposure by forming a protective film using the protective film-forming composition for immersion exposure of the present invention.

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, resist film, protective film 11 Wafer stage

Claims (2)

(A) a resin that is insoluble in water and soluble in an alkaline developer, and (b) an ester solvent in which the hydrogen bonding component δh [(cal / cm ³ ) ^1/2 ] of SP value is in the following range: 0 <δh <8.5
A protective film-forming composition for immersion exposure, comprising:   A step of forming a resist film from the resist composition, forming a protective film on the resist film from the protective film-forming composition according to claim 1, immersion exposing the resist film, and developing. Pattern forming method.

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