TWI383257B - Positive photoresist composition for liquid immersion exposure and pattern forming method using same - Google Patents

Description

Positive photoresist composition for liquid immersion exposure and pattern forming method using same

The present invention relates to a positive photoresist composition used in a semiconductor manufacturing process of an IC or the like, a circuit substrate for manufacturing a liquid crystal, a thermal needle, and the like, and a photolithography process for other photoresist applications, and a pattern forming method using the same . In particular, it is a positive-type photoresist composition suitable for exposure by a liquid immersion projection exposure apparatus having a 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 shortening of the wavelength of the exposure light source and the high number of apertures (high NA) of the projection mirror, an exposure machine of NA 0.84 using an ArF excimer laser having a wavelength of 193 nm as a light source has been developed. These can be expressed by the following general formula.

(resolution) = k ₁ . (λ/NA) (focus depth) = ± k ₂ . λ/AN ² where λ is the wavelength of the exposure source, NA is the number of apertures of the projection mirror, and k ₁ and k ₂ are the coefficients of the relevant process.

In addition, an exposure machine that uses a F ₂ excimer laser having a wavelength of 157 nm as a light source by high-resolution resolution by wavelength short-wavelength is reviewed, but the lens material and photoresist used in the exposure apparatus for short-wavelength are used. Since the raw material is very limited, it is extremely difficult to stabilize the manufacturing cost or quality of the device or the raw material, and there is no possibility of having an exposure device and a photoresist having sufficient performance and stability at the same time.

A technique for improving the resolution in an optical microscope has been conventionally known in which a high refractive index liquid (hereinafter referred to as "liquid immersion liquid") is filled between a projection mirror and a sample, and a so-called liquid immersion method is known.

The "liquid immersion effect" is λ ₀ is the wavelength of the exposure light source in the air, n is the refractive index of the liquid immersion liquid for air, θ is the convergence half angle of the light, and NA ₀ = sin θ, when the liquid immersion is the above The resolution and depth of focus are expressed by the following formula.

(resolution) = k ₁ . (λ ₀ /n) NA ₀ (focus depth) = ± k ₂ . (λ ₀ /n) / NA ₀ ² In other words, the liquid immersion effect is equal to the exposure wavelength using the wavelength of 1/n. That is, when the projection optical system of the same NA is used, the depth of focus can be made n times by liquid immersion. This is extremely effective for the pattern shape, and it is currently reviewed that a super-resolution technique such as a phase shift method or a deformed illumination method can be combined.

Examples of the apparatus for applying the fine pattern transfer of the semiconductor element are disclosed in Patent Document 1 (Japanese Patent Publication No. Sho 57-153433) and Patent Document 2 (Japanese Patent Laid-Open No. Hei 7-220990). Suitable for immersion exposure technology.

In the patent document 3 (JP-A No. 10-303114), it is indicated that the refractive index of the liquid immersion liquid is extremely important due to the change in the refractive index of the liquid immersion liquid, resulting in deterioration of the projection image. The temperature coefficient of the refractive index of the liquid immersion liquid is controlled to a certain range, or water having an additive which lowers the surface tension or increases the degree of interface activity is added as a suitable liquid immersion liquid. However, there has been no disclosure of additives or discussion of photoresist used in immersion exposure techniques.

Recently, Non-Patent Document 1 (SPIE Proc 4688, 11 (2002)), Non-Patent Document 2 (J. Vac. Sci. Tecnol. B 17 (1999)), etc. report on liquid immersion exposure technology and the like. When an ArF excimer laser is used as the light source, it is preferable to use pure water (refractive index of 193 nm of 1.44) as the liquid immersion liquid for the safety and the transmittance and refractive index of 193 nm. When a F ₂ excimer laser is used as a light source, a fluorine-containing solution is discussed from the balance between the transmittance at 157 nm and the refractive index, but sufficient environmental safety or refractive index has not been found. The immersion exposure technique in which the degree of the liquid immersion effect and the completion degree of the photoresist are first considered is mounted on the ArF exposure machine.

In the case where the KrF excimer laser (248 nm) is used for photoresist, in order to compensate for the decrease in sensitivity due to light absorption, a chemically enlarged image forming method is used as a method of forming a photoresist image. When the positive-type chemical amplification type image forming method is described as an example, the acid generator in the exposed portion is decomposed to generate acid by exposure, and the baked after exposure (PEB: post-exposure baking), and the generated acid is used as a reaction. The catalyst is a method in which an alkali-insoluble group is changed to an alkali-soluble group, and an exposed portion is removed by alkali development to form an image.

In the immersion exposure, the immersion liquid (also referred to as liquid immersion liquid) is filled between the photoresist film and the optical mirror, and the pattern of the reticle is transferred onto the photoresist film by exposure through the reticle. It is predicted that the impregnating solution is affected by a chemical reaction (acid catalyst type deprotection reaction, development reaction) caused by exposure inside or after exposure of the photoresist film due to penetration into the inside of the photoresist film. However, the extent or organization of the impact is still unclear.

When the chemical amplification type resist is used in the liquid immersion exposure technique, the acid on the resist surface generated during the exposure moves in the liquid immersion liquid to change the acid concentration on the surface of the exposed portion. This is the exposure of the largest problem in the development of chemically amplified positive photoresists - Post Exposure time Delay (PEB), the exposure surface caused by the extremely small amount of alkaline contamination of the ppb level in terms of the environment. The phenomenon of acid inactivation is very similar, but it is still unclear whether the immersion exposure is affected by the photoresist or the mechanism.

For example, when exposure is performed to expose a chemically amplified resist film which is not problematic in lithography, it is necessary to improve the deterioration of the exposure range and the development time correlation. The exposure range refers to the width at which the exposure amount can be allowed to change when a predetermined pattern is formed. The larger the exposure range, the less likely it is to be affected by changes in exposure, and the performance is good. The development time correlation refers to the degree of change in the pattern size by the development time. When the development time correlation is larger, the dimensional uniformity in the wafer surface is deteriorated, and the controllability of the process is difficult.

[Patent Document 1] Japanese Patent Publication No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. (Proc, SPIE), 2002, Vol. 4688, p. 11 [Non-Patent Document 2] J. Vac. Sci. Tecnol. B 17 (1999)

SUMMARY OF THE INVENTION The object of the present invention is to provide a positive-type photoresist composition suitable for liquid immersion exposure, which has a wide exposure range and a small development time correlation, in view of the above-mentioned problems of the prior art.

The present invention is a positive-type photoresist composition for liquid immersion exposure of the following constitution, whereby the above object of the invention can be achieved.

(1) A positive-type photoresist composition for liquid immersion exposure, which comprises (A) an alicyclic hydrocarbon structure having a monocyclic or polycyclic ring, and having an OH value of 0.0001 to 0.005 milliequivalent, which is increased by an acid action a resin which is soluble in an alkali developing solution, and (B) a compound which generates an acid by irradiation with active rays or radiation.

(2) A pattern forming method comprising forming a photoresist film by the positive-type photoresist composition according to (1) above, and subjecting the photoresist film to liquid immersion exposure and development.

[effect of the invention]

According to the present invention, it is possible to provide a positive-type photoresist composition suitable for liquid immersion exposure and a pattern forming method using the same, which is less susceptible to exposure and development processing conditions such as exposure amount and development time.

[In order to implement the best form of the invention]

The invention is described in detail below.

Further, in the description of the group (atomic group) of the present invention, it is not described that when substituted or unsubstituted, it contains an unsubstituted group and a substituent. For example, "alkyl" includes an unsubstituted alkyl group (unsubstituted alkyl group), a substituted alkyl group (substituted alkyl group).

[1] Resin which increases the solubility of alkali imaging solution by acid action

A resin (referred to as an acid-decomposable resin (A)) which increases the solubility in an alkali developing solution by an acid action contained in the positive-working composition for immersion exposure of the present invention, and has an OH value of 0.0001 to 0.005 equivalent, and has a single ring. Or a polycyclic alicyclic hydrocarbon structure.

[Acidolytic Group]

Further, the resin contained in the positive-type resist composition for liquid immersion exposure of the present invention is a resin (acid-decomposable resin) which increases the solubility of the alkali developing solution by an acid action, and contains a substance which is decomposed by an acid to generate a base. A repeating unit of a soluble group (acid-decomposable group).

An alkali-soluble group such as a hydroxyl group, a carboxyl group, a sulfonic acid group or the like.

The acid-decomposable group may be present in the main chain or side chain of the resin, or both the main chain and the side chain.

The most preferred group among the acid-decomposable groups is a group substituted with a group in which a hydrogen atom of the -COOH group is desorbed by an acid.

The acid-decomposable group is, for example, a cumyl group, an enol ester group, an acetal ester group, a tertiary alkyl ester group or the like. Preferred are a tertiary alkyl ester group and the like.

The acid-decomposable group which the acid-decomposable resin (A) may have, such as O-C(R _{3 6} )(R _{3 7} )(R _{3 8} ), -O-C(R _{3 6} )(R _{3 7} )( OR _{3 9} ), -O-C(=O)-O-C(R _{3 6} )(R _{3 7} )(R _{3 8} ), -O-C(R _{0 1} )(R _{0 2} )(OR _{3 9} ), -O-C(R _{0 1} )(R _{0 2} )-C(=O)-O-C(R _{3 6} )(R _{3 7} )(R _{3 8} ), and the like.

In the formula, each of R _{3 6} to R _{3 9} represents an independent alkyl group, a cycloalkyl group, an aryl group, an arylalkyl group or an alkenyl group. R _{3 6} and R _{3 7} , R _{3 6} and R _{3 9} may be bonded to each other to form a ring.

Each of R _{0 1} to R _{0 2} represents an independent hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an arylalkyl group or an alkenyl group.

Further, -C(R _{3 6} )(R _{3 7} )(R _{3 8} ) means a group in which each group represented by R _{3 6} to R _{3 9 is} bonded by a single bond at a carbon atom. The same is true in the following.

The content of the repeating unit having an acid-decomposable group in the acid-decomposable resin (A) is preferably from 10 to 70 mol% in all repeating units, more preferably from 20 to 65 mol%, and most preferably 25~50% by mole.

[OH price]

The acid-decomposable resin (A) contained in the positive-type resist composition of the present invention has an OH value of 0.0001 to 0.005 equivalent, preferably 0.0001 to 0.003 equivalent, more preferably 0.0001 to 0.002 equivalent.

In the present invention, the OH value means the molar equivalent of OH of 1 g of the acid-decomposable resin. In other words, the OH number can be determined by the number/molecular weight of the OH group.

For example, the vinyl alcohol unit (-CH ₂ -CH(OH)-) has a molecular weight of 44, and since it has one OH group, the OH value is 1/44 equivalent.

In order to obtain an acid-decomposable resin (A) having an OH value of 0.0001 to 0.005 milliequivalent, a repeating unit containing an OH group (hydroxyl group) can be introduced into the resin.

The repeating unit containing an OH group may be a repeating unit having one or more OH groups. Further, the acid-decomposable resin (A) may contain two or more kinds of repeating units having one or more OH groups.

The repeating unit containing an OH group is preferably a repeating unit having an OH group and having a monocyclic or polycyclic alicyclic hydrocarbon structure, and a repeating unit in which an OH group is directly bonded to an alicyclic hydrocarbon structure is more preferable.

When the OH value of the acid-decomposable resin (A) is 0.0001 to 0.005 milliequivalent, the molecular weight of the monomer, the number of OH in the repeating unit, and the ratio of the repeating unit having the OH group in all repeating units are 1~ 70% by mole.

Specific examples of the repeating unit containing an OH group are as follows, but are not limited to the specific examples.

[monocyclic or polycyclic alicyclic hydrocarbon structure]

Further, the acid-decomposable resin (A) has a monocyclic or polycyclic alicyclic hydrocarbon structure.

The acid-decomposable resin (A) contains at least one repeating unit selected from a moiety having an alicyclic hydrocarbon represented by the following formula (pI) to formula (pVI) and a formula (II-AB) The repeating unit shown is preferably a repeating unit having a monocyclic or polycyclic alicyclic hydrocarbon structure.

First, a partial structure containing an alicyclic hydrocarbon represented by the general formula (pI) to the general formula (pVI) will be described.

Wherein R _{1 1} represents methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl or 2-butyl, and Z represents a carbon atom and is necessary for forming an alicyclic hydrocarbon group Atomic group.

R _{1 2} to R _{1 6} each represents an independent carbon number of 1 to 4 linear or branched alkyl or alicyclic hydrocarbon groups, but at least one of R _{1 2} to R _{1 4} or R _{1 5} , R ₁ Any one of ₆ is an alicyclic hydrocarbon group.

Each of R _{1 7} to R _{2 1} represents an independent hydrogen atom, a carbon number of 1 to 4 linear or branched alkyl groups or an alicyclic hydrocarbon group, and at least one of R _{1 7} to R _{2 1} is an alicyclic ring. a hydrocarbon group. Further, any of R _{1 9} and R _{2 1} is a linear or branched alkyl group having 1 to 4 carbon atoms or an alicyclic hydrocarbon group.

Each of R _{2 2} to R _{2 5} represents an independent hydrogen atom, a carbon number of 1 to 4 linear or branched alkyl groups or an alicyclic hydrocarbon group, and at least one of R _{2 2} to R _{2 5} represents a lipid. A cyclic hydrocarbon group. Moreover, R _{2 3} and R _{2 4} may be bonded to each other to form a ring.

The alicyclic hydrocarbon group of R _{1 1} to R _{2 5 or} the alicyclic hydrocarbon group formed by Z and a carbon atom may be monocyclic or polycyclic. Specifically, for example, it has a monocyclic, bicyclic, tricyclic or tetracyclic structure having a carbon number of 5 or more. The carbon number is preferably from 6 to 30, and more preferably from 7 to 25. These alicyclic hydrocarbon groups may have a substituent.

Preferred alicyclic hydrocarbon groups are adamantyl, norantantyl, decalin, tricyclodecyl, tetracyclododecyl, norbornyl, cedarol, cyclohexyl, cycloheptyl , cyclooctyl, cyclodecyl, cyclododecyl. More preferred are adamantyl, decalin, norbornyl, cedarol, cyclohexyl, cycloheptyl, cyclooctyl, cyclodecyl, cyclododecyl.

The substituent of the alicyclic hydrocarbon group is, for example, an alkyl group, a halogen atom, a hydroxyl group, an alkoxy group, a carboxyl group or an alkoxycarbonyl group. The alkyl group is preferably a lower alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group or a butyl group, and more preferably a methyl group, an ethyl group, a propyl group or an isopropyl group. The alkoxy group is, for example, a methoxy group, an ethoxy group, a propoxy group or a butoxy group having 1 to 4 carbon atoms. The above alkyl group, alkoxy group, alkoxycarbonyl group or the like may have a substituent such as a hydroxyl group, a halogen atom or an alkoxy group.

The structure represented by the above formula (pI) to (pVI) of the resin can be used to protect an alkali-soluble group. Alkali soluble groups are, for example, various groups well known in the art.

Specific examples thereof include a carboxylic acid group, a sulfonic acid group, a phenol group, a thiol, etc., and a carboxylic acid group or a sulfonic acid group is preferred.

The alkali-soluble group which is protected by the general formula (pI) to (pVI) of the above-mentioned resin is preferably a structure in which a hydrogen atom of a carboxyl group is substituted with a structure represented by the general formula (pI) to (pVI).

For example, a repeating unit represented by the following formula (pA) is preferred.

Wherein R represents a hydrogen atom, a halogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms (substituted alkyl group, particularly fluorine-substituted alkyl group). A number of Rs may be the same or different.

A represents a single bond, alone or in combination of two or more selected from alkyl, ether, thioether, carbonyl, ester, decyl, decyl, urethane, or ureido groups. The basis.

The Ra system represents any one of the above formulas (pI) to (pVI).

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

The following are specific examples of the repeating unit represented by the formula (pA).

(where Rx is H, CH ₃ or CF ₃ )

Further, the unit having an alicyclic hydrocarbon structure is, for example, the following repeating unit.

Next, the repeating unit having the alicyclic structure represented by the general formula (II-AB) will be explained.

In the formula (II-AB): R _{1 1} ' and R _{1 2} ' each represent an independent hydrogen atom, a cyano group, a halogen atom or an alkyl group.

Z' is a carbon atom (C-C) containing a bond, and is represented by an atomic group in the case of forming an alicyclic structure.

Further, the repeating unit represented by the above formula (II-AB) is preferably a repeating unit represented by the following formula (II-A) or formula (II-B).

In the formulae (II-A) and (II-B): R _{1 3} '~R _{1 6} ' each represents an independent hydrogen atom, a halogen atom, a hydroxyl group, a cyano group, -COOH, -COOR ₅ , and is acted upon by an acid. Decomposed group, -C(=O)-X-A'-R _{1 7} ', alkyl or cyclic hydrocarbon group.

Here, R ₅ means an alkyl group, a cyclic hydrocarbon group, or a -Y group described below.

X represents an oxygen atom-based, a sulfur atom, -NH -, - NHSO ₂ - or -NHSO ₂ NH-.

A' represents a single bond or a divalent bond group.

Further, at least two of R _{1 3} '~R _{1 6} ' may be bonded to form a ring. The n system represents 0 or 1.

R _{1 7} ' represents -COOH, -COOR ₅ , -CN, hydroxy, alkoxy, -CO-NH-R ₆ , -CO-NH-SO ₂ -R ₆ or the -Y group described below.

R ₆ represents an alkyl group or a cyclic hydrocarbon group.

-Y base: In the -Y group, R _{2 1} '~R _{3 0} ' each represents an independent hydrogen atom or an alkyl group. a and b represent 1 or 2.

In the formula (pI) to (pVI), the alkyl group of R _{1 2} to R _{2 5} represents a linear or branched alkyl group having 1 to 4 carbon atoms. The alkyl group may, for example, be a methyl group, an ethyl group, a n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a 2-butyl group or a 3-butyl group.

Further, the substituent which each of the above-mentioned alkyl groups may have is, for example, a C 1 to 4 alkoxy group, a halogen atom (a fluorine atom, a chlorine atom, a bromine atom or an iodine atom), a mercapto group, a decyloxy group, a cyano group, or the like. A hydroxyl group, a carboxyl group, an alkoxycarbonyl group, a nitro group or the like.

In the above formula (II-AB), R _{1 1} ' and R _{1 2} ' each independently represent a hydrogen atom, a cyano group, a halogen atom or an alkyl group.

Z' is a carbon atom (C-C) containing a bond, and is represented by an atomic group in the case of forming an alicyclic structure.

Examples of the halogen atom of R _{1 1} ' and R _{1 2} ' include a chlorine atom, a bromine atom, a fluorine atom, an iodine atom and the like.

The alkyl group of the above R _{1 1} ', R _{1 2} ', R _{2 1} '~R _{3 0} ' is preferably a linear or branched alkyl group having 1 to 10 carbon atoms, more preferably a carbon number of 1 ~6 linear or branched alkyl groups, most preferably methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, 2-butyl, 3-butyl.

Further substituents of the above alkyl group are, for example, a hydroxyl group, a halogen atom, a carboxyl group, an alkoxy group, a decyl group, a cyano group, a decyloxy group or the like. Examples of the halogen atom include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom. The alkoxy group has a carbon number of 1 to 4 such as a methoxy group, an ethoxy group, a propoxy group or a butoxy group. A mercapto group, an ethenyl group or the like, and a decyloxy group has, for example, an ethoxy group.

The atomic group of the alicyclic structure which forms the above Z, is an atomic group which forms a repeating unit of an alicyclic hydrocarbon which may have a substituent in the resin, wherein a repeating unit which forms a bridged alicyclic hydrocarbon is present The atomic group of the bridged alicyclic structure is preferred.

The structure of the alicyclic hydrocarbon formed is, for example, the same as the alicyclic hydrocarbon group of R _{1 1} to R _{2 5 in} the formula (pI) to (pVI).

The structure of the above alicyclic hydrocarbon may also have a substituent. The substituent is, for example, R _{1 3} '~R _{1 6} ' in the above formula (II-A) or (II-B).

In the above repeating unit having a bridged alicyclic hydrocarbon, the repeating unit represented by the above formula (II-A) or (II-B) is more preferable.

In the repeating unit represented by the formula (II-AB), the acid-decomposable group is also contained in the above -C(=O)-X-A'-R _{1 7} ', and includes an alicyclic structure forming Z'. Has a substituent.

The structure of the acid-decomposable group is represented by -C(=O)-X ₁ -R ₀ .

In the formula, R _{0 is,} for example, a 3-alkyl group such as a 3-butyl group or a 3-pentyl group, an isobornyl group, a 1-ethoxyethyl group, a 1-butoxyethyl group or a 1-isobutoxy group. Alkoxymethyl, 3-carbonylalkyl, etc. of 1-alkoxyethyl, 1-methoxymethyl, 1-ethoxymethyl, etc., such as ethyl or 1-cyclohexyloxyethyl And a tetrahydropyranyl group, a tetrahydrofuranyl group, a trialkylformamyl ester group, a 3-carbonylcyclohexyl ester group, a 2-methyl-2-adamantyl group, a mevalonate residue, and the like. The X ₁ system is synonymous with the above X.

The halogen atom of the above R _{1 3} '~R _{1 6} ' may, for example, be a chlorine atom, a bromine atom, a fluorine atom or an iodine atom.

The alkyl group of the above R ₅ , R ₆ and R _{1 3} '~R _{1 6} ' is preferably a linear or branched alkyl group having 1 to 10 carbon atoms, more preferably a carbon number of 1 to 6 straight. The chain or branched alkyl group is preferably a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a 2-butyl group or a 3-butyl group.

The cyclic hydrocarbon group of the above R ₅ , R ₆ and R _{1 3} '~R _{1 6} ' may, for example, be a cyclic alkyl group or a bridged hydrocarbon such as a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, an adamantyl group, or 2 -methyl-2-adamantyl, norbornyl, borneol, isobornyl, tricyclodecyl, dicyclopentyl, norbornyl epoxy, menthyl, isomenthyl, neomentyl, Tetracyclododecyl and the like.

At least two of the above R _{1 3} '~R _{1 6} ' are bonded to form a ring, for example, a ring having a carbon number of 5 to 12 such as cyclopentane, cyclohexane, cycloheptane or cyclooctane.

The alkoxy group of the above R _{1 7} ' has, for example, a methoxy group, an ethoxy group, a propoxy group, a butoxy group or the like having 1 to 4 carbon atoms.

Examples of the other substituents in the alkyl group, the cyclic hydrocarbon group and the alkoxy group include a hydroxyl group, a halogen atom, a carboxyl group, an alkoxy group, a decyl group, a cyano group, a decyloxy group, an alkyl group, and a cyclic hydrocarbon group. The halogen atom is, for example, a chlorine atom, a bromine atom, a fluorine atom, an iodine atom or the like. The alkoxy group has, for example, a methoxy group, an ethoxy group, a propoxy group, a butoxy group or the like having 1 to 4 carbon atoms. The mercapto group is, for example, a methyl group, an ethyl group or the like. The decyloxy group is, for example, an ethoxylated group or the like.

Further, the cyclic hydrocarbon group is exemplified as described above.

The above-mentioned A' divalent bond group, for example, alone or in combination of two or more, is selected from the group consisting of an alkylene group, an ether group, a thioether group, a carbonyl group, an ester group, a decylamino group, a decylamino group, and a urethane group. , the basis of the urea group.

The various substituents of R _{1 3} '~R _{1 6} ' in the above formula (II-A) or formula (II-B) are atomic groups in the formation of the alicyclic structure of the above formula (II-AB). Or a substituent forming a radical Z of a bridged alicyclic structure.

Specific examples of the repeating unit represented by the above formula (II-A) or formula (II-B) are as follows, but the present invention is not limited by these specific examples.

In the acid-decomposable resin (A) having a monocyclic or polycyclic alicyclic hydrocarbon structure, the acid-decomposable group may have an alicyclic hydrocarbon represented by the above formula (pI) to formula (pVI). A repeating unit of a partial structure, a repeating unit represented by the formula (II-AB), and a repeating unit of the other copolymerized components described below.

Further, the acid-decomposable resin (A) preferably has a lactone group, more preferably has the following formula (Lc) or has any one of the following formulae (III-1) to (III-5); The repeating unit of the group of the lactone structure, the group having the lactone structure can be directly bonded to the main chain.

In the general formula (Lc), R _{a 1} , R _{b 1} , R _{c 1} , R _{d 1} and R _{e 1} each independently represent a hydrogen atom or an alkyl group. The m and n systems each represent an independent integer of 0 to 3, and m+n is 2 to 6.

In the general formulae (III-1) to (III-5), R _{1 b} to R _{5 b} each represents an independent hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, an alkoxycarbonyl group or an alkylsulfonium group. Alkylene or alkenyl. Two of R _{1 b} to R _{5 b} may be bonded to form a ring.

An alkyl group of R _{a 1} to R _{e 1 in} the formula (Lc) and an alkyl group, alkoxy group or alkoxycarbonyl group of R _{1 b} to R _{5 b} of the formula (III-1) to (III-5) The alkyl group in the alkylsulfonyl imido group may have, for example, a linear or branched alkyl group, and may have a substituent.

Preferred substituents are, for example, an alkoxy group having 1 to 4 carbon atoms, a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom), a fluorenyl group having 2 to 5 carbon atoms, and a carbon number of 2 to 5. An oxy group, a cyano group, a hydroxyl group, a carboxyl group, an alkoxycarbonyl group having 2 to 5 carbon atoms, a nitro group or the like.

a repeating unit having a group having a lactone structure represented by the formula (Lc) or any one of the formulae (III-1) to (III-5), for example, the above formula (II-A) or (II) -B-yl person) in the _{R 1 3 '~ R 1 6} ' having at least one of the general formula (Lc) or the general formula (III-1) ~ (III -5) shown in the (R ₅ -COOR ₅ of e.g. The formula (Lc) or the group represented by the formula (III-1) to (III-5) or the repeating unit represented by the following formula (AI).

In the formula (AI), R _{b 0} represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms. Preferred substituents which may be contained in the alkyl group of R _{b 0} are, for example, those exemplified by preferred substituents of the alkyl group in R _{1 b} of the above formula (III-1) to (III-5).

The halogen atom of R _{b 0} includes, for example, a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R _{b 0} is preferably a hydrogen atom.

A represents a single bond, an ether group, an ester group, a carbonyl group, an alkylene group, or a combination of these two valent groups.

The B _{2 group} represents a group represented by the formula (Lc) or any one of the formulae (III-1) to (III-5).

The following are specific examples of repeating units having a group having a lactone structure, but the present invention is not limited thereto.

(wherein Rx represents H, CH ₃ or CF ₃ ) (where Rx is H, CH ₃ or CF ₃ ) (where Rx is H, CH ₃ or CF ₃ )

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

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

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

The repeating unit having a group represented by the formula (IV), for example, at least one of R _{1 3} ' to R _{1 6} ' in the above formula (II-A) or (II-B) has the above formula (IV) The group shown (for example, R ₅ of -COOR ₅ represents a group represented by the formula (IV)), or a repeating unit represented by the following formula (AII).

In the formula (AII), R _{1 c} represents a hydrogen atom or a methyl group.

Each of R _{2 c} to R _{4 c} represents an independent hydrogen atom or a hydroxyl group. However, at least one of R _{2 c} to R _{4 c} is a hydroxyl group. It is preferred that at least two of R _{2 c} to R _{4 c} are a hydroxyl group.

The following is a specific example of a repeating unit having a structure represented by the general formula (AII), but is not limited thereto.

The acid-decomposable resin (A) may further contain a repeating unit represented by the following formula (V).

In the above formula (V), Z ₂ represents -O- or -N(R _{4 1} ). R _{4 1} represents a hydrogen atom, a hydroxyl group, an alkyl group or -OSO ₂ -R _{4 2} . R _{4 2} represents an alkyl group, a cycloalkyl group or a camphor residue. The alkyl group of R _{4 1} or R _{4 2} , a cycloalkyl group, or a camphor residue may be substituted with a halogen atom (preferably a fluorine atom) or the like.

The repeating unit represented by the above formula (V) is, for example, the following specific examples, but is not limited thereto.

The acid-decomposable resin (A) is preferably made only of a (meth)acrylic repeating unit.

The acid-decomposable resin (A) may contain, in addition to the above-mentioned repeating structural unit, a resolution and heat resistance for adjusting dry etching resistance, standard developing solution suitability, substrate adhesion, photoresist appearance, and general characteristics of photoresist. Various repetitive structural units for the purpose of sensitivity and the like.

The repeating structural unit has, for example, a repeating structural unit of the following monomers, but is not limited thereto.

This allows fine-tuning of the properties required for acid-decomposable resins, in particular (1) solubility in coating solvents (2) film forming properties (glass transfer points) (3) alkali developability (4) film edge (closeness) (Aqueous, alkali-soluble base selection) (5) Adhesion of the unexposed part to the substrate (6) Dry etching resistance and the like.

The monomer has, for example, an addition polymerization property selected from the group consisting of acrylates, methacrylates, acrylamides, methacrylamides, allyl compounds, vinyl ethers, vinyl esters, and the like. A compound that saturates a bond, and the like.

Further, it may be an addition polymerizable unsaturated compound copolymerizable with the monomers of the above various repeating structural units, or may be copolymerized.

In the acid-decomposable resin (A), the molar ratio of each repeating structure unit is generally necessary for adjusting the dry etching resistance of the photoresist or the standard developing liquid suitability, the substrate adhesion, the photoresist profile, and the photoresist. The resolution, heat resistance, sensitivity, etc. of the performance are appropriately set.

A preferred embodiment of the acid-decomposable resin (A) of the present invention is as follows.

(1) A repeating unit containing a partial structure having an alicyclic hydrocarbon represented by the above formula (pI) to (pVI) (side chain type) (2) containing a repeating unit represented by the general formula (II-AB) (Main chain type) However, for example, (2) is as follows.

(3) The repeating unit represented by the formula (II-AB), the maleic anhydride derivative, and the (meth) acrylate structure (mixed type) acid-decomposable resin (A) have a formula (pI)~ The content of the repeating unit of the partial structure of the alicyclic hydrocarbon represented by (pVI) is preferably from 20 to 70 mol% in the total repeating structural unit, more preferably from 24 to 65 mol%, and most preferably 28 ~60% by mole.

In the acid-decomposable resin (A), the content of the repeating unit represented by the formula (II-AB) is preferably from 10 to 60 mol%, more preferably from 15 to 55 mol%, in all repeating structural units. The best is 20~50%.

Further, based on the monomer of the above other copolymerization component, generally, the content of the repeating structural unit in the resin is a structure having a partial structure containing an alicyclic hydrocarbon represented by the above formula (pI) to (pVI). The total number of moles of the repeating structural unit and the repeating unit represented by the above formula (II-AB) is preferably 99% by mole or less, more preferably 90% by mole or less, and most preferably 80% by mole. %the following.

Further, in particular, the content of the repeating unit having the lactone structure and the group having the formula (IV) (hydroxyadamantane structure) are as follows.

For the total number of moles of the repeating structural unit having a partial structure of the alicyclic hydrocarbon represented by the above formula (pI) to (pVI) and the repeating unit represented by the above formula (II-AB), The content of the repeating unit of the lactone structure is preferably from 1 to 70 mol%, more preferably from 10 to 70 mol%.

The content of the repeating unit having a group represented by the formula (IV) is preferably from 1 to 70 mol%, more preferably from 1 to 50 mol%.

When the composition of the present invention is used for ArF exposure, it is preferred that the resin has no aromatic group in terms of transparency to ArF light.

The acid-decomposable resin (A) can be synthesized by a usual method (for example, radical polymerization).

For example, in a general synthesis method, a monomer is added in one time or added to a reaction vessel during the reaction, and the substance is dissolved in a reaction solvent as needed (for example, tetrahydrofuran, 1,4-dioxane, diisopropyl ether, etc.) An ether or a ketone such as methyl ethyl ketone or methyl isobutyl ketone, an ester solvent such as ethyl acetate, and propylene glycol monomethyl ether acetate as described below, a solvent which dissolves the composition of the present invention, After forming a homogeneous phase, it is heated as required in an inert gas atmosphere such as nitrogen or argon, and polymerization is started using a commercially available radical polymerization initiator (azo initiator, peroxide, etc.). The initiator may be added in a batchwise manner, and the desired polymer may be recovered by a method such as powder or solid recovery after the completion of the reaction. The reaction concentration 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 ° C to 100 ° C.

The above repeating structural units may be used in combination of one kind or in combination of several kinds. Further, in the present invention, the resin may be used singly or in combination of several kinds.

The weight average molecular weight of the acid-decomposable resin (A) is preferably from 1,000 to 200,000, more preferably from 3,000 to 20,000, in terms of polystyrene by the GPC method. When the weight average molecular weight is 1,000 or more, heat resistance and dry etching resistance can be improved, and by setting the weight average molecular weight to 200,000 or less, development performance can be improved, viscosity can be lowered, and film formability can be improved.

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

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

[2] (B) Compound which generates an acid by irradiation with active light or radiation. The compound which produces an acid by active light or radiation irradiation using the positive-type photoresist composition for immersion exposure of this invention (hereinafter referred to as " The acid generator ") is as follows.

The acid generator used in the present invention may be selected from compounds generally used as an acid generator.

In other words, it can be suitably selected from a photo-cationic polymerization photoinitiator, a photo-radical polymerization photoinitiator, a pigment photodecolorizer, a photochromic agent, or a micro-resistance, etc., by active light or Radiation is a conventional compound which produces an acid and a mixture thereof.

For example, there are diazo sulfonium salts, sulfonium salts, strontium salts, iodonium salts, sulfhydrazine sulfonates, sulfonium sulfonates, diazobiszepines, diterpenes, and o-nitrobenzylsulfonates.

In addition, for the compound which generates an acid group by active light or radiation, or a compound which is introduced into a polymer main chain or a side chain, for example, U.S. Patent No. 3,849,137, German Patent No. 3914407, and Japanese Patent Laid-Open No. 63 -26653, JP-A-55-164824, JP-A-62-69263, JP-A-63-146038, JP-A-63-163452, JP-A-62-153853, JP-A-63-146029 The compound described in No. et al.

Further, a compound which generates an acid by light as described in U.S. Patent No. 3,779,778, European Patent No. 126,712, and the like.

Preferred examples of the acid generator include compounds represented by the following formulae (ZI), (ZII) and (ZIII).

In the above formula (ZI), R _{2 0 1} , R _{2 0 2} and R _{2 0 3} each represent an independent organic group.

The X system represents a non-nuclear anion.

In general, the organic groups of R _{2 0 1} , R _{2 0 2} and R _{2 0 3 have} a carbon number of from 1 to 30, preferably from 1 to 20.

Further, at least two of R _{2 0 1} to R _{2 0 3} may be bonded to form a ring structure, and may also contain an oxygen atom, a sulfur atom, an ester bond, a guanamine bond or a carbonyl group in the ring.

A group in which at least two of R _{2 0 1} to R _{2 0 3} are bonded, for example, an alkylene group (e.g., a butyl group, a pentyl group).

Specific examples of the organic group of R _{2 0 1} , R _{2 0 2} and R _{2 0 3} correspond to the groups of the following compounds (Z1-1), (Z1-2) and (Z1-3).

Further, it may be a compound having a structure represented by a plurality of formula (ZI). At least one configuration example having the general formula (ZI) of the compound represented by R _{2 0 1 ~ R 2 0 3} , with at least one of the general formula (ZI) compound shown in the other R _{2 0 1} ~ R _{2 0 3} bonded Compound.

More preferred (ZI) components are, for example, the compounds (Z1-1), (Z1-2), and (Z1-3) described below.

The compound (Z1-1) is an arylsulfonium salt compound in which at least one R _{2 0 1} to R _{2 0 3} of the above formula (ZI) is an aryl group, that is, a compound having an arylsulfonium salt as a cation.

The arylsulfonium salt compound may have all of R _{2 0 1} to R _{2 0 3} as an aryl group, or a part of R _{2 0 1} to R _{2 0 3 may} be an aryl group, and the rest may be an alkyl group or a cycloalkyl group.

The arylsulfonium salt compound is, for example, a triarylsulfonium salt compound, a diarylalkylsulfonium salt compound, an aryldialkylsulfonium salt compound, a diarylcycloalkylsulfonium salt compound, or an arylbicycloalkylsulfonium salt compound. Wait.

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

The arylsulfonium salt compound preferably has a linear or branched alkyl group having 1 to 15 carbon atoms, such as a methyl group, an ethyl group, a propyl group, a n-butyl group, and a 2-butyl group, depending on the desired alkyl group. Base, 3-butyl group, and the like.

The arylsulfonium salt compound is preferably a cycloalkyl group having 3 to 15 carbon atoms, such as a cyclopropyl group, a cyclobutyl group, a cyclohexyl group or the like, depending on the cycloalkyl group which it is required to have.

An aryl group, an alkyl group or a cycloalkyl group of R _{2 0 1} to R _{2 0 3} may have an alkyl group (for example, a carbon number of 1 to 15), a cycloalkyl group (for example, a carbon number of 3 to 15), and an aryl group (for example, carbon). A number 6 to 14), an alkoxy group (for example, a carbon number of 1 to 15), a halogen atom, a hydroxyl group, a phenylthio group or the like is used as a substituent. Preferred substituents are a linear or branched alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, and most preferably a carbon number of 1 to 4 The alkyl group and the alkoxy group having 1 to 4 carbon atoms. 3 may be substituted with a substituent R _{2 0 1} ~ R in any of the _203, all three can also be substituted. Further, when R _{2 0 1} to R _{2 0 3} is an aryl group, the substituent is preferably substituted at the p-position of the aryl group.

The non-nucleating anion of X includes, for example, a sulfonic acid anion, a carboxylic acid anion, a sulfonyl quinone imine anion, a bis(alkylsulfonyl) quinone imine anion, a sulfonium alkylsulfonyl methyl anion, and the like. .

The non-nuclear anion is an anion having an extremely low ability to cause a nuclear reaction, and an anion which is decomposed over time can be suppressed by an intramolecular nuclear reaction. Thereby, the stability of the photoresist over time can be improved.

Examples of the sulfonic acid anion include an aliphatic sulfonic acid anion, an aromatic sulfonic acid anion, a camphorsulfonic acid anion, and the like

The carboxylic acid anion is, for example, an aliphatic carboxylic acid anion, an aromatic carboxylic acid anion, an aralkylcarboxylic acid anion or the like.

The aliphatic group of the aliphatic sulfonic acid anion, for example, has an alkyl group having 1 to 30 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, a n-butyl group, an isobutyl group, and a 2-butyl group. , pentyl, neopentyl, hexyl, heptyl, octyl, decyl, decyl, undecyl, dodecyl, tetradecyl, pentadecyl, hexadecyl, heptadecane Base, octadecyl, nonadecyl, eicosyl, and cycloalkyl having 3 to 30 carbon atoms, and specific examples thereof include cyclopropyl, cyclopentyl, cyclohexyl, adamantyl, norbornyl , borneol base, etc.

The aromatic group of the aromatic sulfonic acid anion is preferably an aryl group having 6 to 14 carbon atoms, and examples thereof include a phenyl group, a tolyl group, and a naphthyl group.

The alkyl group, the cycloalkyl group and the aryl group of the aliphatic sulfonic acid anion and the aromatic sulfonic acid anion may have a substituent.

The substituent is, for example, a nitro group, a halogen atom (a fluorine atom, a chlorine atom, a bromine atom or an iodine atom), a carboxyl group, a hydroxyl group, an amine group, a cyano group, an alkoxy group (preferably having a carbon number of 1 to 5), and a cycloalkane. a base (preferably having a carbon number of 3 to 15), an aryl group (preferably having a carbon number of 6 to 14), an alkoxycarbonyl group (preferably having a carbon number of 2 to 7), and a mercapto group (preferably The carbon number is 2 to 12), the alkoxycarbonyloxy group (preferably, the carbon number is 2 to 7), the alkylthio group (preferably, the carbon number is 1 to 15), and the like. The aryl group and the ring structure which each group has may be, for example, an alkyl group (preferably having a carbon number of 1 to 15) as a substituent.

The aliphatic group of the aliphatic carboxylic acid anion may be, for example, the same as the aliphatic group of the aliphatic sulfonic acid anion.

The aromatic group of the aromatic carboxylic acid anion may be, for example, the same as the aromatic group of the aromatic sulfonic acid anion.

The aralkyl group of the aralkylcarboxylic acid anion is preferably an aralkyl group having 6 to 12 carbon atoms, and examples thereof include a benzyl group, a phenethyl group, a naphthylmethyl group, a naphthylethyl group and the like.

The aliphatic carboxylic acid anion, the aromatic carboxylic acid anion, and the aliphatic group, the aromatic group, and the aralkyl group of the aralkyl carboxylic acid anion may have a substituent, and the substituent may be, for example, the same halogen as the aliphatic sulfonate anion. Atom, alkyl, cycloalkyl, alkoxy, alkylthio, and the like.

A sulfonyl quinone imine anion such as a saccharin anion.

An alkyl group of a bis(alkylsulfonyl)indolide anion or a sulfonium (alkylsulfonyl)methyl anion, preferably an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, Isopropyl, n-butyl, isobutyl, 2-butyl, pentyl, neopentyl and the like. These alkyl groups may have a substituent, and a substituent such as a halogen atom, an alkyl group substituted with a halogen atom, an alkoxy group, an alkylthio group or the like is preferable, and an alkyl group substituted with a halogen atom is preferred.

Other non-nuclear anions such as phosphorus fluoride, boron fluoride, cesium fluoride, and the like.

The non-nucleating anion of X is an aliphatic sulfonate anion substituted with a fluorine atom at the α position of the sulfonic acid, an aromatic sulfonate anion substituted with a fluorine atom or a group having a fluorine atom, and a double substituted with a fluorine atom at the alkyl group. Alkylsulfonyl) anthracene anion, and an alkyl (alkylsulfonyl)methide anion having an alkyl group substituted with a fluorine atom is preferred. The non-nucleating anion is preferably a perfluorinated aliphatic sulfonic acid anion having 4 to 8 carbon atoms, an aromatic sulfonic acid anion having a fluorine atom, and an anion of hexafluorobutanesulfonate and perfluorooctane sulfonate. The anion, the pentafluorobenzenesulfonic acid anion, and the 3,5-bis(trifluoromethyl)benzenesulfonate anion are most preferred.

Next, the related compound (Z1-2) will be explained.

The compound (Z1-2) is a compound in the case where each of R _{2 0 1} to R _{2 0 3 in} the formula (ZI) represents an independent organic group containing no aromatic ring. Among them, the aromatic ring also contains an aromatic ring containing a hetero atom.

The organic group containing no aromatic ring of R _{2 0 1} to R _{2 0 3 has a} carbon number of usually 1 to 30, preferably 1 to 20.

R _{2 0 1} to R _{2 0 3} are each independently an alkyl group, a cycloalkyl group, an aryl group or a vinyl group, more preferably a linear, branched, cyclic 2-carbonylalkyl group or an alkoxy group. The carbonylcarbonyl group is preferably a linear, branched 2-carbonylalkyl group.

The alkyl group of R _{2 0 1} to R _{2 0 3} may be linear or branched, preferably a linear or branched alkyl group having 1 to 10 carbon atoms, such as methyl, ethyl, propyl or butyl. Base, amyl group, etc. The alkyl group is more preferably a 2-linear or branched carbonylalkyl group or an alkoxycarbonylmethyl group.

The cycloalkyl group of R _{2 0 1} to R _{2 0 3} is preferably a cycloalkyl group having 3 to 10 carbon atoms, such as a cyclopentyl group, a cyclohexyl group, a norbornyl group or the like. The cycloalkyl group is more preferably a 2-carbonylcycloalkyl group.

The 2-carbonylalkyl group may be a straight chain, a branched chain or a cyclic group, and preferably has a group of >C=O at the 2-position of the above-mentioned alkyl group or cycloalkyl group.

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

R _{2 0 1} to R _{2 0 3} may be substituted by a halogen atom, an alkoxy group (for example, a carbon number of 1 to 5), a hydroxyl group, a cyano group or a nitro group.

In R _{2 0 1} to R _{2 0 3} , two bonds may form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester bond, a guanamine bond, or a carbonyl group. The group in which two of R _{2 0 1} to R _{2 0 3} are bonded is, for example, an alkyl group (e.g., a butyl group, a pentyl group).

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

Each of R _{1 c} to R _{5 c} represents an independent hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, or a halogen atom.

R _{6 c} and R _{7 c} represent a hydrogen atom, an alkyl group or a cycloalkyl group.

R _x and R _y each represent an independent alkyl group, a cycloalkyl group, an aryl group or a vinyl group.

Any two or more of R _{1 c} to R _{5 c} and each of R _x and R _y bond to form a ring structure, and the ring structure may also contain an oxygen atom, a sulfur atom, an ester bond, or a guanamine bond.

The Zc system represents a non-nucleating anion, for example, the same as the non-nucleating anion of X- in the general formula (ZI).

The alkyl group of R _{1 c} to R _{7 c} is preferably a C 1 to 20 linear or branched alkyl group, such as a methyl group, an ethyl group, a linear or branched propyl group, a linear or branched butyl group. , linear or branched pentyl and the like.

The cycloalkyl group of R _{1 c} to R _{7 c} is preferably a C 3-8 cycloalkyl group such as a cyclopentyl group or a cyclohexyl group.

The alkoxy group of R _{1 c} to R _{5 c} 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. a group (for example, a methoxy group, an ethoxy group, a linear or branched propoxy group, a linear or branched butoxy group, a linear or branched pentyloxy group), and a cyclic alkoxy group having a carbon number of 3 to 8. (e.g., cyclopentyloxy, cyclohexyloxy).

Preferably, any one of R _{1 c} to R _{5 c} is a linear or branched alkyl group, a cycloalkyl group, or a linear, branched or cyclic alkoxy group, more preferably R _{1 c} ~R The carbon number of _{5 c} is 2 to 15. Thereby, the solvent solubility can be further improved, and the occurrence of particles during storage can be suppressed.

The alkyl group and the cycloalkyl group of R _x and R _{y are} , for example, the same as the alkyl group of R _{1 c} to R _{7 c and} the cycloalkyl group, and are a 2-carbonylalkyl group, a 2-carbonylcycloalkyl group or an alkoxycarbonyl group. The base is better.

The 2-carbonylalkyl group, the 2-carbonylcycloalkyl group, for example, the alkyl group of R _{1 c} to R _{7 c} , has a group of >C=O at the 2-position of the cycloalkyl group.

The alkoxy group of the alkoxycarbonylmethyl group is, for example, the same as the alkoxy group of R _{1 c} to R _{5 c} .

The group formed by the bonding of R _x and R _{y is} , for example, a butyl group, a pentyl group or the like.

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

In the general formulae (ZII) and (ZIII), each of R _{2 0 4} to R _{2 0 7} represents an independent aryl group, an alkyl group or a cycloalkyl group.

The aryl group of R _{2 0 4} to R _{2 0 7} is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group.

The alkyl group of R _{2 0 4} to R _{2 0 7} is preferably a linear or branched alkyl group having 1 to 10 carbon atoms, such as a methyl group, an ethyl group, a propyl group, a butyl group or a pentyl group.

The cycloalkyl group of R _{2 0 4} to R _{2 0 7} is preferably a cycloalkyl group having 3 to 10 carbon atoms, such as a cyclopentyl group, a cyclohexyl group, a norbornyl group or the like.

a substituent which R _{2 0 4} to R _{2 0 7} may have, such as an alkyl group (e.g., a carbon number of 1 to 15), a cycloalkyl group (e.g., a carbon number of 3 to 15), an aryl group (e.g., a carbon number of 6 to 15), Alkoxy groups (such as carbon number 1 to 15), halogen atoms, hydroxyl groups, phenethyl groups, and the like.

The X-system represents a non-nuclear anion and is the same as the non-nuclear anion of X- in the general formula (ZI).

Preferred examples of the acid generator include compounds represented by the following formulae (ZIV), (ZV) and (ZVI).

In the general formulae (ZIV) to (ZVI), each of Ar ₃ and Ar ₄ represents an independent aryl group.

R _{2 0 6} , R _{2 0 7} and R _{2 0 8} represent an alkyl group, a cycloalkyl group or an aryl group, which may be the same as the alkyl group, cycloalkyl group or aryl group of R _{2 0 4} to R _{2 0 7} Part A represents an alkylene group, an alkenylene group, and an arylene group.

More preferably, the acid generator is a compound represented by the formula (ZI) to (ZIII).

Among the compounds which generate an acid by active light or radiation, it is more preferably as described below.

The acid generators may be used alone or in combination of two or more.

The content of the acid generator in the positive resist composition for liquid immersion exposure is preferably 0.1 to 20% by mass, more preferably 0.5 to 10% by mass based on the total solid content of the photoresist composition, and most preferably 0.5 to 10% by mass. The amount is 1 to 7 mass%.

[3] (C) The solubility in the alkali developing solution is increased by the decomposition of the acid, and the dissolution preventing compound having a molecular weight of 3,000 or less is used as the positive resist composition for the immersion exposure of the present invention to be decomposed by the action of the acid. A dissolution preventing compound (hereinafter referred to as "dissolution preventing compound") having a solubility greater than that in the alkali developing solution and having a molecular weight of 3,000 or less is preferred.

When the dissolution preventing compound does not lower the permeability of 220 nm or less, the acid-decomposable group-containing alicyclic or fat of the acid-decomposable group-containing alkyd derivative described in Proceeding of SPIE, 2724, 355 (1996) Family compounds are preferred. The acid-decomposable group or the alicyclic structure is, for example, the same as those described above for the acid-decomposable resin (A).

The molecular weight of the dissolution preventing compound of the present invention is 3,000 or less, preferably 300 to 3,000, and more preferably 500 to 2,500.

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

The following are specific examples of the dissolution preventing compound, but are not limited thereto.

[4] (D) Basic compound In the positive resist composition for liquid immersion exposure of the present invention, it is preferred to further contain a basic compound. As the basic compound, for example, a nitrogen-containing basic compound, a basic ammonium salt, a basic sulfonium salt, an alkaline iodonium salt or the like is used, and the sublimation or the photoresist performance is not lowered.

The basic compound is a component having a function of suppressing diffusion of an acid generated by an acid generator in the photoresist film by exposure, and suppressing an undesired chemical reaction in a non-exposure range. By blending the basic compound, the diffusion of the acid generated by the acid generator in the photoresist film can be suppressed, and the storage stability of the positive resist composition for liquid immersion exposure can be improved, and the light can be improved. The resolution of the resist suppresses the change in the line width of the resist pattern due to the change in the standing time (PED) from the exposure to the development process, and a composition excellent in process safety can be obtained.

The nitrogen-containing basic compound is, for example, a primary, secondary, tertiary aliphatic amine, an aromatic amine, a heterocyclic amine, a nitrogen-containing compound having a carboxyl group, a nitrogen-containing compound having a sulfonyl group, and a nitrogen-containing compound having a hydroxyl group. A compound, a nitrogen-containing compound having a hydroxyphenyl group, an alcoholic nitrogen-containing compound, a guanamine derivative, a quinone imine derivative, a nitrogen-containing compound having a cyano group, or the like.

Aliphatic amines such as methylamine, ethylamine, n-propylamine, isopropylamine, n-butylamine, isobutylamine, 2-butylamine, 3-butylamine, pentylamine, 3-pentylamine, cyclopentylamine , hexylamine, cyclohexylamine, heptylamine, octylamine, decylamine, decylamine, dodecylamine, hexadecylamine, methyldiamine, ethylenediamine, tetraethylamine, dimethylamine, Ethylamine, di-n-propylamine, diisopropylamine, di-n-butylamine, diisobutylamine, di-butylamine, diamylamine, dicyclopentylamine, dihexylamine, dicyclohexylamine, diheptylamine, Dioctylamine, diamine, diamine, di-dodecylamine, di-hexadecaneamine, N,N-dimethyldiamine, N,N-dimethylethylenediamine, N, N-Dimethyltetraethylamine, trimethylamine, triethylamine, tri-n-propylamine, triisopropylamine, tri-n-butylamine, triisobutylamine, tri-butylamine, triamylamine, three Cyclopentylamine, trihexylamine, tricyclohexylamine, triheptylamine, trioctylamine, tridecylamine, tridecylamine, tri-dodecylamine, tri-hexadecylamine, N,N,N', N'-tetramethylmethyldiamine, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-tetramethyltetraethylamine Dimethyl amine, methyl ethyl propyl amine, benzylamine, phenethylamine, benzyl dimethylamine and the like.

Aromatic amines and heterocyclic amines, such as aniline derivatives (such as aniline, N-methylaniline, N-ethylaniline, N-propylaniline, N,N-dimethylaniline, 2-methyl Aniline, 3-methylaniline, 4-methylaniline, ethylaniline, propylaniline, trimethylaniline, 2-nitroaniline, 3-nitroaniline, 4-nitroaniline, 2,4-di Nitroaniline, 2,6-dinitroaniline, 3,5-dinitroaniline, N,N-dimethyltoluidine, etc.), diphenyl (p-tolyl)amine, methyldiphenylamine, Triphenylamine, phenylenediamine, naphthylamine, diaminonaphthalene, pyrrole derivatives (such as pyrrole, 2H-pyrrole, 1-methylpyrrole, 2,4-dimethylpyrrole, 2,5-dimethylpyrrole, N-methylpyrrole, etc., oxazole derivatives (such as oxazole, isoxazole, etc.), thiazole derivatives (such as thiazole, isothiazole, etc.), imidazole derivatives (such as imidazole, 4-methylimidazole, 4- Methyl-2-phenylimidazole, etc.), pyrazole derivatives, Brazilian hydrocarbon derivatives, pyrroline derivatives (such as pyrroline, 2-methyl-1-pyrroline, etc.), pyrrolidine derivatives (such as pyrrolidine) N-methylpyrazine , Pyrroline, N- methylpyrrolidone, etc.), imidazoline derivatives, imidazole Derivative, pyridyl Derivative Methylpyridyl Propyl pyridyl Butylpyrryl 4-(1-butylpentyl)pyrene Dimethylpyrimidine Trimethylpyridinium Triethylpyr Phenylpyrrole 3-methyl-2-phenylpyrazine 4-Diethyl 3-pyridyl Diphenylpyridinium Benzylpyrrole Methoxypyridinium Butoxypyrrolidine Dimethoxypyridinium , 1-methyl-2-pyridone, 4-pyrrolidinopyridine, 1-methyl-4-phenylpyridine, 2-(1-ethylpropyl)pyridine, aminopyridine, dimethylamino Pyridine, etc.) Derivative, pyrimidine derivative, pyridyl Derivatives, pyrazoline derivatives, pyrazolidine derivatives, piperidine derivatives, piperidine Derivative, morpholine derivative, hydrazine Derivatives Derivative, 1H-吲 Derivative, 吲 Full derivatives, quinoline derivatives (such as quinoline, 3-quinoline carbonyl tolyl, etc.), isoquinoline derivatives, porphyrin derivatives, quinazoline derivatives, quinoxaline derivatives, hydrazine Derivatives, anthracene derivatives, pteridine derivatives, carbazole derivatives, phenanthridine derivatives, acridine derivatives, phenanthrene Derivatives, 1,10-phenanthroline derivatives, adenine derivatives, adenosine derivatives, guanine derivatives, guanosine derivatives, uracil derivatives, uridine derivatives, and the like.

a nitrogen-containing compound having a carboxyl group, for example, an aminobenzoic acid or an anthracene Carboxylic acid, amino acid derivatives (such as nicotinic acid, alanine, arginine, aspartic acid, glutamic acid, glycine, histidine, isoleucine, glycidyl leucine, Amino acid, methionine, phenylalanine, threonine, lysine, 3-aminopyran-2-carboxylic acid, methoxyalanine) and the like.

The nitrogen-containing compound having a sulfonyl group is, for example, 3-pyridinesulfonic acid, p-toluenesulfonic acid pyridinium or the like.

The nitrogen-containing compound having a hydroxyl group is, for example, 2-hydroxypyridine, aminocresol, 2,4-quinodiazole or 3-oxime. Hydride, 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-hydroxyl Ethyl) piperidine , 1-[2-(2-hydroxyethoxy)ethyl]piperidin Pyr Ethanol, 1-(2-hydroxyethyl)pyrrolidine, 1-(2-hydroxyethyl)-2-pyrrolidone, 3-piperider 1,2-propanediol, 3-pyrrolidone-1,2-propanediol, 8-hydroxyjulolidine, 3-fast ricinole, 3-terpineol, 1-methyl-2-pyrrolidine Ethanol, 1-azacyclopropaneethanol, N-(2-hydroxyethyl) quinone imine, N-(2-hydroxyethyl)isonicotinamine, and the like.

The indoleamine derivatives are, for example, formamide, N-methylformamide, N,N-dimethylformamide, acetamide, N-methylacetamide, N,N-dimethylacetamidine. Amine, acrylamide, benzoguanamine, and the like.

The quinone imine derivatives are, for example, quinone imine, squalene quinone imine, maleimide, and the like.

Specific examples of the nitrogen-containing compound having a cyano group are, for example, 3-(diethylamino)propionitrile, N,N-bis(2-hydroxyethyl)-3-aminopropionitrile, N,N-bis(2- Ethyloxyethyl)-3-aminopropionitrile, N,N-bis(2-methylmethoxyethyl)-3-aminopropionitrile, N,N-bis(2-methoxyB 3-Aminopropionitrile, N,N-bis[2-(methoxymethoxy)ethyl]-3-aminopropionitrile, N-(2-cyanoethyl)-N- Methyl (2-methoxyethyl)-3-aminopropionate, methyl N-(2-cyanoethyl)-N-(2-hydroxyethyl)-3-aminopropanoate, N -(2-Ethyloxyethyl)-N-(2-cyanoethyl)-3-aminopropionic acid methyl ester, N-(2-cyanoethyl)-N-ethyl-3- Aminopropionitrile, N-(2-cyanoethyl)-N-(2-hydroxyethyl)-3-aminopropionitrile, N-(2-acetoxyethyl)-N-(2 -Cyanoethyl)-3-aminopropionitrile, N-(2-cyanoethyl)-N-(2-methylmethoxyethyl)-3-aminopropionitrile, N-(2- Cyanoethyl)-N-(2-methoxyethyl)-3- Aminopropionitrile, N-(2-cyanoethyl)-N-[2-(methoxymethoxy)ethyl]-3-aminopropionitrile, N-(2-cyanoethyl) -N-(3-hydroxy-1-propyl)-3-aminopropionitrile, N-(3-acetoxy-1-propyl)-N-(2-cyanoethyl)-3- Aminopropionitrile, N-(2-cyanoethyl)-N-(3-methylmethoxy-1-propyl)-3-aminopropionitrile, N-(2-cyanoethyl)- N-tetrahydrofuranyl-3-aminopropionitrile, N,N-bis(2-cyanoethyl)-3-aminopropionitrile, diethylaminoacetonitrile, N,N-bis(2-hydroxyethyl) Aminoacetonitrile, N,N-bis(2-acetoxyethyl)aminoacetonitrile, N,N-bis(2-methylmethoxyethyl)aminoacetonitrile, N,N-bis ( 2-methoxyethyl)aminoacetonitrile, N,N-bis[2-(methoxymethoxy)ethyl]aminoacetonitrile, N-cyanomethyl-N-(2-methoxy Methyl ethyl-3-aminopropionate, methyl N-cyanomethyl-N-(2-hydroxyethyl)-3-aminopropanoate, N-(2-acetoxyethyl) )-N-cyanomethyl-3-aminopropionic acid , N-cyanomethyl-N-(2-hydroxyethyl)aminoacetonitrile, N-(2-acetoxyethyl)-N-(cyanomethyl)aminoacetonitrile, N-cyano Methyl-N-(2-methylmethoxyethyl)aminoacetonitrile, N-cyanomethyl-N-(2-methoxyethyl)aminoacetonitrile, N-cyanomethyl-N- [2-(Methoxymethoxy)ethyl]aminoacetonitrile, N-(cyanomethyl)-N-(3-hydroxy-1-propyl)aminoacetonitrile, N-(3-acetonitrile Oxy-1-propyl)-N-(cyanomethyl)aminoacetonitrile, N-cyanomethyl-N-(3-methylnonyloxy-1-propyl)aminoacetonitrile, N,N - bis(cyanomethyl)aminoacetonitrile, 1-pyrrolidinepropionitrile, 1-piper Propionitrile, 4-morpholinepropionitrile, 1-pyrrolidineacetonitrile, 1-piper Acetonitrile, 4-morpholineacetonitrile, cyanomethyl 3-diethylaminopropionate, cyanomethyl N,N-bis(2-hydroxyethyl)-3-aminopropionate, N,N- Cyanomethyl bis(2-acetoxyethyl)-3-aminopropanoate, cyanomethyl N,N-bis(2-methyloxyethyl)-3-aminopropanoate, N,N-bis(2-methoxyethyl)-3-aminopropionic acid cyanomethyl ester, N,N-bis[2-(methoxymethoxy)ethyl]-3-amino Cyanomethyl propionate, 3-diethylaminopropionic acid (2-cyanoethyl), N,N-bis(2-hydroxyethyl)-3-aminopropionic acid (2-cyanoethyl) Ester), N,N-bis(2-acetoxyethyl)-3-aminopropionic acid (2-cyanoethyl ester), N,N-bis(2-methylmethoxyethyl)- 3-Aminopropionic acid (2-cyanoethyl ester), NN-bis(2-methoxyethyl)-3-aminopropionic acid (2-cyanoethyl ester), N,N-double [2 -(methoxymethoxy)ethyl]-3-aminopropionic acid (2-cyanoethyl ester), 1-pyrrolidinepropionic acid cyanomethyl ester, 1-piper Cyanomethyl propionate, cyanomethyl 4-morpholinepropionate, 1-pyrrolidonic acid (2-cyanoethyl ester), 1-piper Propionic acid (2-cyanoethyl ester), 4-morpholinepropionic acid (2-cyanoethyl ester).

The nitrogen-containing basic compound is 1,5-diazobicyclo[4.3.0]-5-nonene, 1,8-diazobicyclo[5.4.0]-7-undecene, 1,4-two Azobicyclo[2.2.2]octane, 4-dimethylaminopyridine, 1-naphthylamine, pyridyl , hexamethylenetetramine, imidazoles, hydroxypyridines, pyridines, anilines, hydroxyalkylanilines, 4,4'-diaminodiphenyl ether, pyridinium p-toluenesulfonate, 2 , 4,6-trimethylpyridinium p-toluenesulfonate, tetramethylammonium p-toluenesulfonate, tetrabutylammonium laurate, triethylamine, tributylamine, triamylamine, tri-n-octylamine , triisooctylamine, cis (ethylhexyl)amine, tridecylamine, tri-dodecylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, three-positive Octylamine, tri-n-decylamine, tri-n-decylamine, cyclohexyldimethylamine, methyldicyclohexylamine, ethylenediamine, N,N,N',N'-tetramethylethylenediamine, tetramethyl Amine, hexamethyldiamine, 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-amine Phenyl)-2-(3-hydroxyphenyl)propane, 2-(4-aminophenyl)-2-(4-hydroxyphenyl)propane, 1,4-bis[1-(4- Phenyl)-1-methylethyl]benzene, 1,3-bis[1-(4-aminophenyl)-1-methylethyl]benzene, bis(2-dimethylamino) Ethylene, bis(2-diethylaminoethyl)ether, N,N,N',N'-indole (2-hydroxypropyl)ethylenediamine, tricyclohexylamine, etc. Alkylamines, aniline, N-methylaniline, N,N-dimethylaniline, 2-methylaniline, 3-methylaniline, 4-methylaniline, 4-nitroaniline, diphenylamine, triphenylamine An aromatic amine such as naphthylamine or 2,6-diisopropylaniline, a polymer of polyethylenediamine, polyallylamine, 2-dimethylaminoethyl acrylamide, N-t-butyl Oxycarbonyldi-n-octylamine, N-t-butoxycarbonyldi-n-decylamine, N-t-butoxycarbonyldi-n-decylamine, N-t-butoxycarbonylcyclohexane Amine, N-t-butoxycarbonyl-1-adamantanamine, N-t-butoxycarbonyl-N-methyl-1-adamantanamine, N,N-di-t-butoxycarbonyl- 1-adamantanamine, N,N-di-t-butoxycarbonyl-N-methyl-1-adamantanamine, N-t-butoxycarbonyl-4,4'-diaminophenyl , N,N'-di-t-butoxycarbonylhexamethylenediamine, N,N,N',N'-tetra-t-butoxycarbonylhexamethylenediamine, N,N'-di-t-butyl Oxycarbonyl-1,7-diaminoheptane, N,N'-di-butoxycarbonyl-1,8-diaminooctane, N,N'-di-t-1,9-di Aminodecane, N,N'-di-t-butoxycarbonyl-1,10-diaminodecane, N,N'-di-t-butoxycarbonyl-1,12-diamino Dodecane, N,N'-di-t-butoxycarbonyl-4,4'-diaminodiphenylmethane, N-t-butoxycarbonylbenzimidazole, N-t-butoxy Carbonyl-2-methylbenzimidazole, N-t-butoxycarbonyl-2-phenylbenzimidazole, formamide, N-methylformamide, N,N-dimethylformamide, Acetamide, N-methylacetamide, N,N-dimethylacetamide, acetamide, benzoguanamine, pyrrolidone, N-methylpyrrolidone, urea, methylurea, 1,1- Dimethylurea, 1,3-dimethylurea, 1,1,3,3-tetramethylurea, 1,3-diphenylurea, tri-n-butylsulfuric acid, imidazole, 4-methyl Imidazole, 4-methyl-2-phenylimidazole, benzimidazole, 2-benzene Imidazoles such as benzimidazole, pyridine, 2-methylpyridine, 4-methylpyridine, 2-ethylpyridine, 4-ethylpyridine, 2-phenylpyridine, 4-phenylpyridine, 2-methyl Pyridine, piperazine, nicotine, nicotinic acid decylamine, quinoline, 4-hydroxyquinoline, 8-oxoquinoline, acridine, etc. 1-(2-hydroxyethyl)per Piper Class, pyr , pyrazole, hydrazine , quinoxaline, anthracene, pyrrolidine, pyridyl , 3-pyrrolidino-1,2-propanediol, morpholine, 4-methylmorpholine, 1,4-dimethylpyrrol And so on.

Among these, 1,5-diazobicyclo[4.3.0]-5-pinene, 1,8-diazobicyclo[5.4.0]-7-undecene, 1,4- Diazobicyclo[2.2.2]octane, 4-dimethylaminopyridine, 1-naphthylamine, pyridyl 4-hydroxypyridyl 2,2,6,6-tetramethyl-4-hydroxypyridyl , hexamethyltetramine, imidazoles, hydroxypyridines, pyridines, 4,4'-diaminodiphenyl ether, triethylamine, tributylamine, triamylamine, tri-n-octylamine, ginseng (ethyl A nitrogen-containing basic compound such as hexylamine, tri-tridecylamine, N,N-dihydroxyethylaniline or N-hydroxyethyl-N-ethylaniline is more preferred.

In the positive resist composition for liquid immersion exposure of the present invention, a basic ammonium salt can be used as the basic compound. Specific examples of the basic ammonium salt are, for example, the compounds shown below, but are not limited thereto.

Specifically, for example, ammonium hydroxide, ammonium trifluoride, ammonium pentafluoride, ammonium hexafluoride, ammonium hexafluoride, ammonium hexafluoride, ammonium trifluoroammonate, ammonium pentafluoride, ammonium methylcarboxylate , ammonium salt of ammonium carboxylate, ammonium salt of propyl carboxylate, ammonium salt of butyl carboxylate, ammonium salt of pentylcarboxylate, ammonium salt of hexylcarboxylate, ammonium salt of octylcarboxylate, ammonium salt of decylcarboxylate, hydrazine Ammonium carboxylate, ammonium undecylcarboxylate, ammonium laurylcarboxylate, ammonium tridecylcarboxylate, ammonium tetradecylcarboxylate, ammonium pentadecylcarboxylate And an ammonium salt of hexadecylcarboxylate, an ammonium salt of heptadecylcarboxylate, an ammonium octadecylcarboxylate or the like.

Specific examples of the above ammonium hydroxide include tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, tetrapentylammonium hydroxide, tetrahexylammonium hydroxide, tetraheptane Ammonium hydroxide, methyltrioctyl ammonium hydroxide, tetraoctyl ammonium hydroxide, dimercaptodimethylammonium hydroxide, mercapto ammonium hydroxide, dodecyl trimethyl ammonium hydroxide, ten Dialkylethyldimethylammonium hydroxide, di-dodecyldimethylammonium hydroxide, tri-dodecylmethylammonium hydroxide, myristylmethylammonium hydroxide, dimethyldi -tetradecyl ammonium hydroxide, cetyltrimethylammonium hydroxide, octadecyltrimethylammonium hydroxide, dimethyldi-octadecyl ammonium hydroxide, tetra-octadecyl Ammonium hydroxide, diallyldimethylammonium hydroxide, (2-ethyl chloride)-trimethylammonium hydroxide, (2-bromoethyl)trimethylammonium hydroxide, (3-bromo) Propyl)trimethylammonium hydroxide, (3-bromopropyl)triethylammonium hydroxide, epoxypropyltrimethylammonium hydroxide, choline hydroxide, (R)-(+)- (3-chlorinated- 2-hydroxypropyl)trimethylammonium hydroxide, (S)-(-)-(3-chloro-2-hydroxypropyl)-trimethylammonium hydroxide, (3-chlorinated-2-hydroxyl Propyl)-trimethylammonium hydroxide, (2-aminoethyl)-trimethylammonium hydroxide, hexamethylammonium hydroxide, decyl ammonium hydroxide, 1-azo hydrazine salt propane alkoxide Hydrochloric acid, 2-chloro-1,3-dimethyl-2-hydrazinium imidazolium salt, 3-ethyl-2-methyl-hydrazinium hydroxide salt, and the like.

The basic compounds may be used singly or in combination of two or more kinds, and it is preferably used in combination of two or more kinds.

The amount of the basic compound to be used is usually 0.001 to 10% by mass, preferably 0.01 to 5% by mass based on the solid content of the positive-type resist composition for liquid immersion exposure.

[5] (E) Surfactant The positive resist composition for liquid immersion exposure of the present invention preferably further contains (E) a surfactant, and contains a fluorine-based and/or a lanthanoid surfactant (fluorine). Any one or two or more kinds of a surfactant, a lanthanoid surfactant, and a surfactant having both a fluorine atom and a ruthenium atom are preferable.

When the positive-type photoresist composition for liquid immersion exposure of the present invention is used in an exposure light source of 250 nm or less, particularly 220 nm or less, by containing the above (E) surfactant, good sensitivity and resolution can be obtained, and adhesion can be obtained. A photoresist pattern with less defects in sexual and imaging conditions.

For example, Japanese Laid-Open Patent Publication No. SHO-62-36663, JP-A-61-226746, JP-A-61-226745, JP-A-62-170950 Japanese Laid-Open Patent Publication No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. 5360692, the same as No. 5,590, 692, the same as No. 5,296,330, the same as No. 5, 546, 998, the same as No. 5, 576, 143, No. 5,294, 211, and No. 5,842,451, the following surfactants can also be used directly. Surfactant sold.

Commercially available surfactants such as Yebronp EF301, EF303 (New Akita Chemicals Co., Ltd.), Broratton FC430, 431 (Sumitomo Silyem) )), Mekafak (transliteration) F171, F173, F176, F189, R08 (Daily Ink Chemical Industry Co., Ltd.), Sablon (transliteration) S-382, SC101, 102, 103, 104, 105 A fluorine-based surfactant or a quinone-based surfactant such as 106 (made by Asahi Glass Co., Ltd.) or a brocade (Symbol) S-366 (manufactured by Tatsuo Co., Ltd.). Further, a polyoxyalkylene polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) can also be used as the lanthanoid surfactant.

Further, in addition to the above-mentioned ones, a fluorine-based aliphatic compound obtained by adjusting a polymerization reaction method (also referred to as a telomerization method) or an oligomerization method (also referred to as an oligomerization method) can be used. A surfactant having a fluorine-based aliphatic group-based polymer acts as a surfactant. The fluorine-based aliphatic compound can be synthesized by the method described in JP-A-2002-90991.

A polymer having a fluorine-based aliphatic group is preferably a copolymer of a monomer having a fluorine-based aliphatic group and (polyalkylene oxide) acrylate and/or (polyalkylene oxide) methacrylate. It may be irregularly distributed or block copolymerized. Further, the poly(alkylene oxide) is, for example, a polyethylene oxide group, a polypropylene oxide group, a polybutylene oxide group, or the like, and a poly(ethylene oxide and propylene oxide and ethylene oxide embedded). A segment bond), or a unit of an alkylene oxide group having a different chain length within the same chain length, such as a poly(ethylene oxide and propylene oxide block bond). Further, the copolymer of a monomer having a fluorine-based aliphatic group and (poly(alkylene oxide)) acrylate (or methacrylate) may be a binary copolymer or have two or more different fluorines. A monomer of an aliphatic group or a copolymer of a ternary system or more in which two or more different (poly(alkylene oxide)) acrylates (or methacrylates) are copolymerized at the same time.

For example, commercially available surfactants are Meikafak F178, F-470, F-473, F-475, F-476, and F-472 (manufactured by Dainippon Ink Chemical Industry Co., Ltd.). Further, for example, a copolymer of an acrylate (or methacrylate) having a C ₆ F _{13 3} group and a (poly(alkylene oxide)) acrylate (or methacrylate) having a C ₆ F _{1 3} group a copolymer of acrylate (methacrylate) and (poly(ethylene oxide)) acrylate (or methacrylate) and (poly(propylene oxide) acrylate (or methacrylate)), having ₈ F _{1 7} (poly (alkylene oxide)) acrylate (or methacrylate) copolymer C group of the acrylate (methacrylate) with an acrylate having a C ₈ F _{1 7} group of ( a copolymer of (methacrylate) and (poly(ethylene oxide)) acrylate (or methacrylate) and (poly(propylene oxide) acrylate (or methacrylate)).

Further, in the present invention, a surfactant other than a fluorine-based and/or a lanthanoid surfactant may be used. Specifically, for example, polyethylene oxide alkyl ether such as polyethylene oxide lauryl ether, polyethylene oxide stearyl ether, polyethylene oxide hexadecane ether, polyethylene oxide oleyl ether, and the like Polyethylene oxide alkyl allyl ethers such as ethylene oxide octylphenol ether and polyethylene oxide nonylphenol ether, polyethylene oxide polypropylene oxide block copolymers, sorbitol Anhydride monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, sorbitan tristearyl Sorbitol fatty acid esters such as acid esters, polyethylene oxide sorbitan monolaurate, polyethylene oxide sorbitan monopalmitate, polyethylene oxide sorbitan Non-ethylene oxide sorbitan fatty acid esters such as stearate, polyethylene oxide sorbitan trioleate, polyethylene oxide sorbitan tristearate, etc. Ionic surfactants, etc.

These surfactants may be used singly or in combination of several.

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

[6] (F) Organic solvent The positive resist composition for liquid immersion exposure of the present invention can be used by dissolving the above components in a predetermined organic solvent.

The organic solvent to be used is, for example, ethylene dichloride, dicyclohexanone, 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, methoxy Methyl propionate, ethyl ethoxypropionate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, N,N-dimethylformamide, dimethyl hydrazine, N-methylpyrrolidone , methoxybutanol, tetrahydrofuran, and the like.

In the present invention, a mixed solvent in which a solvent having a hydroxyl group in the structure and a solvent having no hydroxyl group are mixed may be used as the organic solvent.

The solvent having a hydroxyl group is, for example, ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, ethyl lactate, etc., among which propylene glycol monomethyl ether, lactic acid Ethyl ester is preferred.

Examples of the solvent having no hydroxyl group are propylene glycol monomethyl ether acetate, ethyl ethoxy propionate, 2-heptanone, γ-butyrolactone, cyclohexanone, butyl acetate, N-methylpyrrolidone, N, N-dimethylvinyl decylamine, dimethyl hydrazine, etc., among which propylene glycol monomethyl ether acetate, ethyl ethoxy propionate, 2-heptanone, γ-butyrolactone, Preferably, cyclohexanone or butyl acetate is more preferably propylene glycol monomethyl ether acetate, ethyl ethoxy propionate or 2-heptanone.

The mixing ratio (mass) of the solvent having a hydroxyl group and the solvent having no hydroxyl group is preferably 1/99 to 99/1, more preferably 10/90 to 90/10, and most preferably 20/80 to 60/40. . In terms of coating uniformity, a mixed solvent containing 50% by mass or more of a solvent having no hydroxyl group is more preferable.

[7] (G) Alkali-soluble resin The positive-type resist composition for liquid immersion exposure of the present invention may further contain a resin soluble in an alkali developing solution, whereby the sensitivity can be improved.

In the present invention, a novolac resin having a molecular weight of about 1,000 to 20,000 and a polyhydroxystyrene derivative having a molecular weight of about 3,000 to 50,000 may be used as the resin, but since such absorption is large for light of 250 nm or less, It is preferably used in the form of partial hydrogenation or in an amount of 30% by mass or less based on the total amount of the resin.

Further, a resin having a carboxyl group as an alkali-soluble group can be used. In the resin having a carboxyl group, it is preferred to have a monocyclic or polycyclic alicyclic hydrocarbon group for improving the dry etching resistance. Specifically, for example, a copolymer of methacrylate and (meth)acrylic acid having an acid-decomposable alicyclic hydrocarbon structure or a (meth)acrylic acid ester having an alicyclic hydrocarbon group having a carboxyl group at the terminal may be used.

The amount of the alkali-soluble resin added is usually 30% by mass or less based on the total amount of the resin containing the acid-decomposable resin.

[8] (H) Cerium carboxylate salt The positive-type photoresist composition for liquid immersion exposure of the present invention may further contain a cerium carboxylate salt.

The cerium carboxylate salt of the present invention may, for example, be a cerium carboxylate salt, a carboxylic acid iodonium salt, a carboxylate ammonium salt or the like. In particular, the (H) cerium carboxylate salt is preferably an iodonium salt or a phosphonium salt. Further, the cerium carboxylate salt of the present invention preferably has a carboxylate residue as an aromatic group-free or carbon-carbon double bond. More preferably, the anion moiety is a linear, branched, monocyclic or polycyclic alkylcarboxylate anion having 1 to 30 carbon atoms. More preferably, some or all of these alkyl groups are anions of a fluorine-substituted carboxylic acid. The alkyl chain may also contain an oxygen atom. Thereby, transparency to light below 220 nm can be ensured, sensitivity and resolution can be improved, and density correlation and exposure range can be improved.

The anion of the fluorine-substituted carboxylic acid is, for example, fluorinated acetic acid, difluorinated acetic acid, acetic acid trifluoride, pentafluoric acid, heptafluorobutyric acid, pentane pentanoic acid, perfluorinated dodecanoic acid, Perfluorinated tridecanoic acid, perfluorinated cyclohexanecarboxylic acid, anion of 2,2-bis-trifluorinated methylpropionic acid, and the like.

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

The content of the cerium carboxylate salt in the composition is 0.1 to 20% by mass, preferably 0.5 to 10% by mass, and more preferably 1 to 7% by mass based on the total solid content of the composition.

[9] Other Additives In the positive resist composition for immersion exposure of the present invention, a dye, a plasticizer, a photosensitizer, and a compound which promotes solubility in a developing solution may be further contained as needed. (for example, a phenol compound having a molecular weight of 1,000 or less, an alicyclic group having a carboxyl group, or an aliphatic compound).

The phenol compound having a molecular weight of 1,000 or less can be easily synthesized by a method described in, for example, JP-A-4-122938, JP-A-2-28531, U.S. Patent No. 4,916,210, and European Patent No. 219,294.

Specific examples of the alicyclic group or the aliphatic compound having a carboxyl group, such as a carboxylic acid derivative having a steroid structure such as cholic acid, deoxycholic acid or lithocholic acid, an adamantanecarboxylic acid derivative, an adamantane dicarboxylic acid, Cyclohexanecarboxylic acid, cyclohexanedicarboxylic acid, etc., are not limited by these.

[10] Pattern forming method The positive resist composition for liquid immersion exposure of the present invention is obtained by dissolving the above components in a predetermined organic solvent, preferably in the above mixed solvent, and then applying them to a predetermined carrier. .

In other words, the positive resist composition for liquid immersion exposure is applied to a precise integrated circuit component by any appropriate thickness (usually 50 to 500 nm) by a suitable coating method such as a spinner or an applicator. The substrate (for example, ruthenium/cerium oxide coated).

After coating, the coated photoresist is dried by a spin or baking method to form a photoresist film, and then exposed to a liquid immersion liquid (liquid immersion exposure) through a photomask or the like which is patterned. For example, the photoresist film and the optical mirror are exposed in a state of being filled with a liquid immersion liquid. The exposure amount can be appropriately set, and is usually 1 to 100 mJ/cm ² . After the exposure, it is preferred to rotate or/and bake, develop and clean, and obtain a good pattern. The baking temperature is usually 30 to 300 °C. In the case of the PED described above, the shorter the time from the exposure to the baking process, the better.

Here, the exposure light source is preferably 250 nm or less, and more preferably 220 nm or less. Specifically, for example, KrF excimer laser (248 nm), ArF excimer laser (193 nm), F ₂ excimer laser (157 nm), X-ray, etc., are more preferably ArF excimer laser (193 nm).

Moreover, the change in performance seen when the photoresist is used for immersion exposure is the origin of the photoresist surface contact liquid immersion liquid.

The liquid immersion liquid used for immersion exposure is as follows.

The liquid immersion liquid is transparent to the exposure wavelength, and the optical image projected on the photoresist is deformed to the minimum limit, and the liquid having the refractive index of the refractive index is preferably as small as possible, in particular, the exposure light source is an ArF excimer mine. In the case of irradiation (wavelength; 193 nm), in addition to the above viewpoint, it is preferable to use water in view of ease of availability and ease of handling.

When water is used as the liquid immersion liquid, in order to reduce the surface tension of water and increase the interfacial activity, only the photoresist layer on the wafer can be dissolved, and the optical coating effect under the mirror element can be neglected. The additive (liquid) is added in proportion. The additive is preferably an aliphatic alcohol having a refractive index almost equal to that of water, and specifically, for example, methanol, ethanol, isopropanol or the like. By adding an alcohol having a refractive index equal to that of water, even if the concentration changes due to evaporation of the alcohol component in the water, there is an advantage that the refractive index change of the entire liquid is extremely small. Further, when a substance which is opaque to 193 nm light or an impurity having a refractive index different from that of water is mixed, the optical image projected on the photoresist is deformed, so that water to be used is preferably distilled water. Further, pure water filtered by an ion exchange filter or the like can be used.

The electric resistance of the water is preferably 18.3 Mcm or more, and the TOC (organic matter concentration) is preferably 20 ppb or less, preferably for degassing.

In addition, the lithography performance can be improved by increasing the refractive index of the liquid immersion liquid. In this regard, an additive for increasing the refractive index may be added to water, and water may be replaced with heavy water (D ₂ O).

In the case where the photoresist film does not directly contact the liquid immersion liquid between the photoresist film and the liquid immersion liquid for the immersion exposure of the present invention, the liquid immersion liquid poorly soluble film (hereinafter referred to as " Surface coating"). The necessary functions of the surface coating are the coating suitability to the upper layer of the photoresist, the transparency to radiation (especially 193 nm), and the poor solubility of the liquid immersion liquid. The surface layer is coated so as not to be mixed with the photoresist, and it is preferable to uniformly coat the upper layer of the photoresist.

In terms of 193 nm transparency, the surface layer is preferably coated with an aromatic-free polymer, such as a hydrocarbon polymer, an acrylate polymer, polymethacrylic acid, polyacrylic acid, polyvinyl ether, a ruthenium-containing polymer, Fluorine-containing polymers and the like.

When peeling the surface layer, a developing solution may be used, or an additional stripping agent may be used. The release agent is preferably a solvent which is less permeable to the photoresist. The stripping process can be simultaneously treated with the photoresist developing process, so that it can be preferably peeled off by the alkali developing solution. In the case of alkali-developing liquid peeling, the surface layer coating is preferably acidic, but may be neutral or alkaline in terms of non-internal mixing with the photoresist.

The difference between the refractive index difference between the surface coating and the liquid immersion liquid can improve the resolution. When the exposure light source is an ArF excimer laser (wavelength: 193 nm), it is preferable to use water as the liquid immersion liquid. Therefore, it is preferable to apply the ArF immersion exposure surface layer to a refractive index close to water (1.44). Moreover, it is transparent ^. It is preferable that the refractive index is thin.

The following developer solution was used in the development process. For the developing solution of the positive-type resist composition for liquid immersion exposure, an inorganic base such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium citrate, sodium methyl citrate or ammonium water, ethylamine or n-propylamine can be used. a secondary amine such as a monoamine, a diethylamine or a di-n-butylamine; a tertiary amine such as triethylamine or methyldiethylamine; an alcohol amine such as dimethylethanolamine or triethanolamine; a quaternary ammonium salt such as tetramethylammonium hydroxide or tetraethylammonium hydroxide, pyrrole or piperazine An alkaline aqueous solution such as a cyclic amine.

Further, an appropriate amount of an alcohol or a surfactant may be added to the above alkaline aqueous solution.

The cleaning solution can be used with pure water or with an appropriate amount of surfactant.

The alkali concentration of the alkali developing solution is usually 0.1 to 20% by mass.

The pH of the alkali imaging solution is usually from 10.0 to 15.0.

Further, after the development processing or the cleaning treatment, a treatment for removing the developing liquid or the cleaning liquid adhering to the pattern by the supercritical fluid can be performed.

[Examples]

In the following, the invention will be described in more detail by way of examples, but the contents of the invention are not limited thereto.

Synthesis Example 1 (Synthesis of Resin (24))

A mixture of 3-butyrolactonecarboxylic acid, 3-butyl ester, norbornanecarboxylic acid, 2-hydroxyethyl norbornanecarboxylic acid and maleic anhydride was dissolved in tetrahydrofuran to prepare a solution having a solid content of 50% by mass. This material was placed in a 3-necked flask and heated under a nitrogen gas stream at 60 °C. When the reaction temperature was stabilized, the reaction was started by adding 5 mol% of a free radical initiator V-60 manufactured by Wako Pure Chemical Industries Co., Ltd. After heating for 6 hours, the reaction mixture was diluted to 2 times with tetrahydrofuran, and then a 5-fold amount of hexane was added to the reaction liquid to precipitate a white powder. The product was redissolved in tetrahydrofuran, and a solution of 5 times the amount of hexane was added to precipitate a white powder. The precipitated powder was taken out by filtration and dried to obtain a resin (24) having the following repeating unit of the object.

When the obtained resin (24) was subjected to molecular weight analysis (RI analysis) by GPC, it was 7900 (weight average) in terms of polystyrene.

Similarly, the following resins (1) to (23), (25), and (26) were obtained.

Mw=9900

Mw/Mn=1.99

1.5 × 10 ^-3 equivalents

Mw=10200

Mw/Mn=1.98

1.2 × 10 ^-3 equivalents

Mw=8900

Mw/Mn=2.10

9.6 × 10 ^-4 equivalents

Mw=8300

Mw/Mn=1.97

1.1 × 10 ^-3 equivalents

Mw=9700

Mw/Mn=1.98

8.9 × 10 ^-4 equivalents

Mw=9700

Mw/Mn=2.01

1.5 × 10 ^-3 equivalents

Mw=8200

Mw/Mn=1.91

1.0×10 ^-3 equivalent

Mw=9500

Mw/Mn=2.07

19 × 10 ^-3 equivalent

Mw=10300

Mw/Mn=2.16

8.3 × 10 ^-4 equivalents

Mw=8700

Mw/Mn=2.21

1.4 × 10 ^-3 equivalents

Mw=8700

Mw/Mn=2.21

2.0×10 ^-3 equivalents

Mw=10200

Mw/Mn=2.31

2.3 × 10 ^-4 equivalents

Mw=8700

Mw/Mn=2.05

3.7 × 10 ^-3 equivalent

Mw=8900

Mw/Mn=2.19

8.2×10 ^-4 equivalents

Mw=10400

Mw/Mn=2.51

6.4 × 10 ^-4 equivalents

Mw=8100

Mw/Mn=2.50

9.6 × 10 ^-4 equivalents

Mw=7900

Mw/Mn=2.33

8.0 × 10 ^-4 equivalent

Mw=9200

Mw/Mn=2.49

8.0 × 10 ^-4 equivalent

Mw=12100

Mw/Mn=2.32

2.0×10 ^-3 equivalents

Mw=9700

Mw/Mn=1.97

0 equivalent

Mw=11500

Mw/Mn=2.00

0 equivalent

Mw=8400

Mw/Mn=2.12

0 equivalent

Mw=9900

Mw/Mn=1.77

0 equivalent

Mw=7900

1.4 × 10 ^-3 equivalents

Mw=9900

Mw/Mn=1.99

5.1 × 10 ^-3 equivalents

Mw=10200

Mw/Mn=1.98

5.8 × 10 ^-3 equivalent

[Examples 1 to 20 and Comparative Examples 1 to 4] <Photoresist adjustment>

The components shown in the following Table 1 were dissolved in a solvent, adjusted to a solution having a solid concentration of 10% by mass, and the material was filtered through a 0.1 μm polyethylene filter to adjust the positive resist solution. The prepared positive resist solution was evaluated in the following manner, and the results are shown in Table 1. Moreover, regarding the components of Table 1, the ratio when several kinds are used is the mass ratio.

In the following, the code of Table 1 is as follows.

The acid generator is corresponding to the above exemplified.

N-1: N,N-dibutylaniline N-2: N,N-dipropylaniline N-3: N,N-dihydroxyethylaniline N-4: 2,4,5-triphenyl Imidazole N-5: Hydroxyhydrogenated Antipyrine W-1: Mecamak F176 (Daily Ink Chemicals Co., Ltd.) (Fluorine) W-2: Mekafak R08 (Daily Ink Chemistry) Industrial (stock) system (fluorine and lanthanide) W-3: polyoxyalkylene polymer KP-341 (Shin-Etsu Chemical Co., Ltd.) (矽) W-4: Dunlong Jeolla S- 366 (Dong Luoyi Kemikaru Co., Ltd.) SL-1: cyclopentanone SL-2: cyclohexanone SL-3: 2-methylcyclohexanone SL-4: propylene glycol monomethyl ether acetate SL-5: propylene glycol monomethyl ether SL-6: 2-heptanone SL-7: γ-butyrolactone SL-8: propylene carbonate I-1: dimethyl cholate 3-butyl ester I-2: King Kong 3-butyl ester of alkanoic acid

[Exposure range]

An organic anti-reflection film ARC29A (manufactured by Nissan Chemical Co., Ltd.) was coated on the tantalum wafer, and baked at 205 ° C for 60 seconds to form a 78 nm anti-reflection film. The prepared photoresist composition was coated thereon and baked at 115 ° C for 60 seconds to form a 250 nm photoresist film. After forming a clay on the obtained wafer and treating it with pure water for 60 seconds, pattern exposure was performed using an ArF excimer laser scanner (PAS5500/1100, NA0.75 manufactured by ASLM Corporation). Further, after the exposure, pure water treatment was performed for 60 seconds (wet exposure). Then, after heating at 150 ° C for 90 seconds, it was developed with a tetramethylammonium hydroxide aqueous solution (2.38 mass%) for 60 seconds, and washed with pure water, followed by spin drying to obtain a photoresist pattern.

For comparison, exposure (dry exposure) was carried out before the exposure and after the exposure without pure water treatment, and a photoresist pattern was obtained under the same conditions as above.

The exposure amount of the mask pattern of the line width of 110 nm and the gap is used as the optimum exposure amount, and the exposure amount width of the allowable pattern size of 110 nm±10% when the exposure amount is changed is obtained, and the value is divided by the optimum exposure amount. Expressed as a percentage. The larger the value, the smaller the performance by the change in the amount of exposure, and the exposure range is good.

[Development time correlation]

An organic anti-reflection film ARC29A (manufactured by Nissan Chemical Co., Ltd.) was coated on the tantalum wafer, and baked at 205 ° C for 60 seconds to form a 78 nm antireflection film. The prepared photoresist composition was coated thereon and baked at 115 ° C for 60 seconds to form a 150 nm photoresist film.

The obtained wafer was made to use water as an immersion liquid, and the apparatus of Fig. 1 was subjected to 2-beam interference exposure (wet exposure) using a prism 8 which forms a mask pattern of a line of 110 nm and a gap. The laser wavelength is 193 nm. After heating at 120 ° C for 60 seconds, it was developed with a tetramethylammonium hydroxide aqueous solution (2.38 mass%) for 60 seconds, washed with pure water, and then rotationally dried to obtain a photoresist pattern.

In the exposure amount of the 110 nm line and the gap reticle pattern size when the development time is 30 seconds, when the development time is 90 seconds, the formation size of the same pattern is the side length, and the size difference (nm) from 110 nm is as shown in the table. 1 is shown. The smaller the difference in size, the smaller and better the development time correlation.

Further, as a comparison, the same evaluation as described above was carried out without exposure by liquid immersion (dry exposure).

Further, in the apparatus shown in Fig. 1, 1 is a laser, 2 is a torsion, 3 is a shutter, 4, 5, and 6 are mirrors, 7 is a collecting mirror, and 8 is a diamond. In the mirror, 9 is a liquid immersion liquid, 10 is a wafer provided with an antireflection film and a photoresist film, and 11 is a wafer stage.

From the above results, it is understood that the positive resist composition for liquid immersion exposure of the present invention has a wide exposure range and a small correlation between development time and good performance when patterned by liquid immersion exposure.

1. . . Laser

2. . . Reverse

3. . . shutter

4,5,6. . . Reflector

7. . . Light collecting mirror

8. . .稜鏡

9. . . Liquid immersion liquid

10. . . Wafer

11. . . Wafer table

Figure 1 is a simplified diagram of a 2-beam interference exposure experimental setup.

Claims (7)

A positive photoresist composition for liquid immersion exposure, which comprises (A) OH having a valence of 0.0001 to 0.005 equivalent and containing a 2-hydroxy-2,2-bis(trifluoromethyl)ethyl group substituted The following three repeating units of the decane structure and the repeating unit represented by the formula (pA), a resin which increases the solubility to the alkali developing solution by an acid action, and (B) by the action of active light or radiation Acid compound; Wherein R is 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; and A means a single bond, alone or in combination of two or more. a group selected from the group consisting of an alkyl group, an ether group, a thioether group, a carbonyl group, an ester group, a decylamino group, a decylamino group, a urethane group, or a urea group; the Ra system represents the formula (pI)~ Any of the bases in (pVI); Wherein R ₁₁ represents a methyl group, an ethyl group, a n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group or a 2-butyl group, and the Z series represents a carbon atom and an atomic group necessary for forming an alicyclic hydrocarbon group. ; R ₁₂ ~ R ₁₆ each represents an independent carbon number of 1 to 4 linear or branched alkyl or alicyclic hydrocarbon groups, but at least one of R ₁₂ to R ₁₄ or any of R ₁₅ and R ₁₆ is An alicyclic hydrocarbon group; each of R ₁₇ to R ₂₁ represents an independent hydrogen atom, a carbon number of 1 to 4 linear or branched alkyl groups or an alicyclic hydrocarbon group, and at least one of R ₁₇ to R ₂₁ is a lipid. a cyclic hydrocarbon group; in addition, any one of R ₁₉ and R ₂₁ is a linear or branched alkyl group or an alicyclic hydrocarbon group having 1 to 4 carbon atoms; and R ₂₂ to R ₂₅ each represents an independent hydrogen atom and carbon. a number of 1 to 4 linear or branched alkyl or alicyclic hydrocarbon groups, wherein at least one of R ₂₂ to R ₂₅ represents an alicyclic hydrocarbon group; moreover, R ₂₃ and R ₂₄ may be bonded to each other to form a ring; The alicyclic hydrocarbon group of R ₁₁ to R _{25 or} the alicyclic hydrocarbon group formed by Z and a carbon atom may be monocyclic or polycyclic; these alicyclic hydrocarbon groups may have a substituent, and the substituent is an alkyl group. , halogen atom, hydroxyl group, alkoxy group, carboxy group , Alkoxycarbonyl. The positive resist composition for liquid immersion exposure according to the first aspect of the invention, wherein the acid-decomposable resin (A) contains a repeating unit having a lactone group represented by the general formula (AI); In the general formula (AI), R _b0 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms; A' represents a single bond, an ether group, an ester group, a carbonyl group, an alkylene group, or a combination thereof. a divalent group; the B ₂ group represents a group represented by any one of the formula (Lc) or the formula (III-1) to (III-5); In the general formula (Lc), R _a1 , R _b1 , R _c1 , R _d1 and R _e1 each represent an independent hydrogen atom or an alkyl group; m and n each represent an independent integer of 0 to 3, and m+n is 2 to 6; in the general formulae (III-1) to (III-5), R _1b to R _5b each represent an independent hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, an alkoxycarbonyl group, or an alkyl group. a sulfonyl imido group or an alkenyl group; two of R _1b to R _5b may be bonded to form a ring; an alkyl group of R _a1 to R _{e1 in} the formula (Lc) and a formula (III-1) to (III) -5) The alkyl group of the alkyl group, the alkoxy group, the alkoxycarbonyl group or the alkylsulfonyl imido group of R _1b to R _5b may be a linear or branched alkyl group, and may have a substitution. The substituent is an alkoxy group having 1 to 4 carbon atoms, a halogen atom, a fluorenyl group having 2 to 5 carbon atoms, a decyloxy group having 2 to 5 carbon atoms, a cyano group, a hydroxyl group, a carboxyl group, and a carbon number 2~ 5 alkoxycarbonyl, nitro. The positive resist composition for liquid immersion exposure according to claim 1, wherein the acid-decomposable resin (A) contains a repeating unit represented by the formula (V); In the 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 ; and R ₄₂ represents an alkyl group or a cycloalkane. a base or a camphor residue; an alkyl group of R ₄₁ and R ₄₂ , a cycloalkyl group, or a camphor residue may be substituted with a halogen atom. A positive resist composition for liquid immersion exposure according to the first aspect of the invention, wherein the photoresist composition comprises (D) a nitrogen-containing basic compound. A positive resist composition for immersion exposure according to the first aspect of the invention, wherein the photoresist composition comprises (E) a fluorine-based and/or a lanthanide-based surfactant. A positive resist composition for immersion exposure according to the first aspect of the invention, wherein the photoresist composition comprises a mixed solvent of a solvent having a hydroxyl group in the structure and a solvent having no hydroxyl group. A pattern forming method is a method of forming a photoresist film by a positive-type photoresist composition according to claim 1 of the patent application, and subjecting the photoresist film to liquid immersion exposure and development.