KR101414535B1 - Positive type photosensitive composition and pattern formation method using the same - Google Patents

Abstract

(Problem) A positive photosensitive composition which is excellent in resolving power even in formation of a fine pattern of 100 nm or less and improved in pattern collapse, exposure latitude and line edge roughness and excellent in controllability of a resist pattern in a thermal flow process and And provides a pattern forming method using the same.

(A) a compound which generates an acid upon irradiation with an actinic ray or radiation and (B) a repeating unit (1) having a specific structure having a tertiary alkyl ester group and a repeating unit A positive photosensitive composition containing a resin having a repeating unit (2) having an alkylene group of 4 to 30 which may be substituted with an ester group and having a dissolution rate increasing to an alkali developing solution by the action of an acid, and a pattern forming method using the positive photosensitive composition .

Positive type photosensitive composition, pattern forming method

Description

TECHNICAL FIELD [0001] The present invention relates to a positive photosensitive composition and a pattern forming method using the positive photosensitive composition.

The present invention relates to a positive photosensitive composition used in a semiconductor manufacturing process such as IC, a process for producing a circuit substrate such as a liquid crystal or a thermal head, and other photolithographic processes, and a pattern forming method using the positive photosensitive composition. More particularly, an exposure light source such as deep ultraviolet light of 250 nm or less, preferably 220 nm or less, and a positive light-sensitive composition which is preferable when it is an irradiation source by electron beam or the like, and a pattern forming method using the same.

The chemical amplification type photosensitive composition is characterized in that an acid is generated in an exposed portion by irradiation with an actinic ray or radiation such as an extraneous light and the solubility of the irradiated portion of the actinic ray or radiation and the non- To form a pattern on a substrate.

When a KrF excimer laser is used as an exposure light source, a resin having a basic skeleton of poly (hydroxystyrene) having a small absorption in the region of 248 nm is mainly used as a main component, so that a high sensitivity, a high resolution and a good pattern are formed, Naphthoquinonediazide / novolac resin of the present invention.

On the other hand, when a light source of a shorter wavelength, for example, ArF excimer laser (193 nm), is used as an exposure light source, the compound having an aromatic group essentially shows a large absorption in the region of 193 nm, I did.

For this reason, resists for ArF excimer lasers containing a resin having an alicyclic hydrocarbon structure have been developed. In the resist for ArF excimer laser, various improvements have been made. For example, in Patent Document 1, Patent Document 2, Patent Document 3, and the like, it is described that repeating units having a spacer portion between a main chain and an acid decomposing unit in an alicyclic acid- Various kinds of characteristics have been improved by introducing a unit.

However, when a fine pattern such as a line width of 100 nm or less is formed, the formed line pattern is collapsed even when the resolution performance is excellent, so that the problem of pattern collapse, which is a defect in manufacturing the device, and the performance stability (exposure latitude) , The above composition was still insufficient.

In addition, as a method for achieving a finer pattern formation in recent years, immersion lithography using a technique of improving resolution in an optical microscope is known. In immersion lithography, a high-refractive-index liquid (hereinafter also referred to as " immersion liquid ") is filled between the projection lens and the sample to expose it.

Recent progress of liquid immersion exposure technology is reported in Non-Patent Document 1, Non-Patent Document 2, Patent Document 4, and the like. When an ArF excimer laser is used as a light source, pure water (refractive index at 193 nm: 1.44) is most promising as an immersion liquid from the viewpoints of handling safety and transmittance and refractive index at 193 nm.

On the other hand, a thermal flow process is a method in which a resist pattern is formed by a conventional lithography technique, and then the resist pattern is heat-treated to miniaturize the pattern size. It is possible to reduce the size of the portion where the pattern is not formed (the hole diameter of the hole pattern, the space width of the line and space pattern, and the like) by softening the resist pattern by heating after the formation of the pattern and causing the resist pattern to flow in the gap direction of the pattern. However, in a conventional resist composition used for ArF excimer laser lithography and the like, since the base resin has a high glass transition temperature, the softening of the base resin due to the heating temperature in the thermal flow process is insufficient, There is a problem that it is difficult. Patent Literatures 5 and 6 attempt to control the pattern size by introducing a low Tg acid decomposable group into the resin. However, such a simple low Tg furnace is difficult to be compatible with the resolution.

From the viewpoint of recent resolution improvement, attempts have been made in Patent Documents 7 and 8 to use resins having acid-decomposable groups at various positions spaced from the polymer main chain through various spacer groups. However, the incorporation of the spacer group alone was insufficient to lower the Tg.

Patent Document 1: JP-A-2005-331918

Patent Document 2: Japanese Patent Application Laid-Open No. 2004-184637

Patent Document 3: Japanese Patent Application Laid-Open No. 2003-330192

Non-Patent Document 1: SPIE Proc 4688, 11 (2002)

Non-Patent Document 2: J. Vac. Sci. Tecnol. B 17 (1999)

Patent Document 4: JP-A-10-303114

Patent Document 5: Japanese Patent Application Laid-Open No. 2007-114412

Patent Document 6: JP-A-2007-114613

Patent Document 7: Japanese Patent Publication No. 2006-501495

Patent Document 8: JP-A-2005-331918

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a positive type resist pattern having excellent controllability of a resist pattern in a thermal flow process in which pattern collapse, exposure latitude and line edge roughness are improved even in the formation of fine patterns of 100 nm or less And a method for forming a pattern using the same.

The present invention is as follows.

(1) (A) of an actinic ray or compounds and (B) to which the repeating unit (1) and -LR ₃ group (formula represented by general formula (Ⅰ) which generates an acid by irradiation with radiation, L is a C4 represents a divalent linking group of the ~ 30, R ₃ has the repeating unit having a represents a hydrogen atom, a hydroxyl group or an organic) (2), by the action of an acid which contains a resin to increase the dissolution rate in an alkali developing solution Wherein the positive photosensitive composition is a positive photosensitive composition.

In the general formula (I)

Xa ₁ represents a hydrogen atom, an alkyl group, a cyano group or a halogen atom.

Ry ₁ , Ry ₂ and Rx each independently represents an alkyl group or a cycloalkyl group.

Za represents an alkylene group.

(2) The positive photosensitive composition as described in (1), wherein the repeating unit (2) is represented by the following general formula (II).

In the general formula (II)

X represents a hydrogen atom, an alkyl group, a cyano group or a halogen atom.

L represents a divalent linking group having 4 to 30 carbon atoms.

R ₃ represents a hydrogen atom, a hydroxyl group or an organic group.

(3) The positive photosensitive composition according to (1) or (2), wherein the resin of the component (B) has at least two kinds of the repeating units (1) represented by the general formula (I).

(4) The positive photosensitive composition as described in any one of (1) to (3), wherein the resin of the component (B) further comprises an acid-decomposable repeating unit (3) different from the repeating unit (1).

(5) The positive photosensitive composition as described in (4), wherein the acid-decomposable repeating unit (3) has a group which is eliminated by the action of an acid represented by the following general formulas (pI) to (pV).

In the general formulas (pI) to (pV)

R ₁₁ represents an alkyl group.

Z represents an atomic group necessary for forming a cycloalkyl group together with a carbon atom.

R ₁₂ to R ₁₄ each independently represent an alkyl group or a cycloalkyl group.

R ₁₅ and R ₁₆ each independently represent an alkyl group or a cycloalkyl group.

R ₁₇ to R ₂₁ each independently represent a hydrogen atom, an alkyl group or a cycloalkyl group, and any one of R ₁₉ and R ₂₁ represents an alkyl group or a cycloalkyl group.

R ₂₂ to R ₂₅ each independently represent a hydrogen atom, an alkyl group or a cycloalkyl group. R ₂₃ and R ₂₄ may be bonded to each other to form a ring.

(6) The positive photosensitive composition as described in (5), wherein the acid-decomposable repeating unit (3) is represented by the following general formula (III-1)

In the general formula (III-1)

R represents a hydrogen atom, a halogen atom or an alkyl group. The plural Rs may be the same or different.

A represents a single bond or a combination of two or more groups selected from the group consisting of a single bond, an alkylene group, an ether group, a thioether group, an amide group, a sulfonamide group, a urethane group or a urea group.

Rp ₁ represents any one of the groups represented by formulas (pI) to (pV).

(7) The positive photosensitive composition as described in (4), wherein the repeating unit (3) is represented by the following general formula (III-2).

In the general formula (III-2)

Xa ₁ represents a hydrogen atom, an alkyl group, a cyano group or a halogen atom.

Rya represents an alkyl group or a cycloalkyl group.

Z ₁ represents an atomic group necessary for forming a cycloalkyl group together with a carbon atom.

Zb represents a divalent linking group.

(8) The positive photosensitive composition as described in any one of (1) to (7), wherein the resin of the component (B) further has a repeating unit (4) represented by the following formula (IV)

In the general formula (IV)

R ₆ represents a hydrogen atom, a halogen atom or an alkyl group.

R ₇ represents a group having a lactone structure.

Ab represents a single bond, an alkylene group, a divalent linking group having a monocyclic or polycyclic alicyclic hydrocarbon structure, an ether group, an ester group, a carbonyl group, or a divalent group obtained by combining these groups.

(9) The positive photosensitive composition as described in any one of (1) to (8), wherein the resin of the component (B) further has a repeating unit (5) represented by the following formula (V)

In the general formula (V)

R ₈ represents a hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl group.

R ₉ represents a group having an alicyclic hydrocarbon structure substituted with a hydroxyl group or a cyano group.

(10) The positive photosensitive composition as described in (9), which has at least one or more kinds of repeating units (1) to (5)

(11) A method for forming a pattern, which comprises a step of forming a film using the positive photosensitive composition described in any one of (1) to (10), and exposing and developing the film.

(Effects of the Invention)

According to the present invention, there is provided a positive photosensitive composition which is improved in pattern collapse, exposure latitude and line edge roughness in formation of a fine pattern of 100 nm or less and has excellent controllability of a resist pattern in a thermal flow process, Can be provided.

Hereinafter, the best mode for carrying out the present invention will be described in detail.

In the description of the groups (atomic groups) in the present specification, the notation in which the substitution and the non-substitution are not limited include those having no substituent and also having a substituent. For example, the "alkyl group" includes not only an alkyl group having no substituent (an unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group).

(A) a compound which generates an acid upon irradiation with an actinic ray or radiation

The positive photosensitive composition of the present invention contains a compound (hereinafter also referred to as " acid generator ") that generates an acid upon irradiation with an actinic ray or radiation.

Examples of the acid generator include known compounds which generate an acid upon irradiation with an actinic ray or radiation used in photocatalytic polymerization of photocationic polymerization, photoinitiator of photo radical polymerization, photochromic agent of colorant, photochromic agent, Can be appropriately selected and used.

Examples thereof include diazonium salts, phosphonium salts, sulfonium salts, iodonium salts, imidosulfonate, oxime sulfonate, diazodisulfone, disulfone, o-nitrobenzylsulfonate and the like.

Further, a group capable of generating an acid upon irradiation with actinic rays or radiation, or a compound in which a compound is introduced into the main chain or side chain of the polymer, such as those described in U.S. Patent No. 3,849,137, German Patent No. 3,914,407, 63-26653, 55-164824, 62-69263, 63-146038, 63-163452, 62-153853, The compounds described in JP-A-63-146029 and the like can be used.

Compounds which generate an acid by the light described in U.S. Patent No. 3,779,778 and European Patent No. 126,712 can also be used.

As preferred compounds in the acid generator, compounds represented by the following general formulas (ZI), (ZII) and (ZIII) can be given.

In the general formula (ZI)

R ₂₀₁ , R ₂₀₂ and R ₂₀₃ each independently represent an organic group.

The number of carbon atoms of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ is generally 1 to 30, preferably 1 to 20.

Further, R ₂₀₁ to R ₂₀₃ medium Two of them may combine to form a ring structure, or may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond and a carbonyl group in the ring. Among R ₂₀₁ to R ₂₀₃ Examples of the group formed by combining two groups include an alkylene group (e.g., a butylene group and a pentylene group).

Z ^- represents an unconjugated anion.

Examples of the non-nucleophilic anion as Z ^- include a sulfonic acid anion, a carboxylic acid anion, a sulfonylimide anion, a bis (alkylsulfonyl) imide anion, and a tris (alkylsulfonyl) methyl anion.

The non-nucleophilic anion is an anion having a remarkably low ability to cause a nucleophilic reaction, and is an anion capable of inhibiting the degradation due to nucleophilic reaction within the molecule. This improves the stability with time of the resist.

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

Examples of the carboxylic acid anion include an aliphatic carboxylic acid anion, an aromatic carboxylic acid anion, and an aralkylcarboxylic acid anion.

The aliphatic moiety in the aliphatic sulfonic acid anion is preferably an alkyl group having 1 to 30 carbon atoms and a cycloalkyl group having 3 to 30 carbon atoms such as a methyl group, an ethyl group, a propyl group, an isopropyl group, an n- Examples of the alkyl group having 1 to 10 carbon atoms include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, pentyl, neopentyl, hexyl, A cyclopentyl group, a cyclohexyl group, an adamantyl group, a norbornyl group, and a boronyl group can be given as examples of the cyclic group.

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

The alkyl group, cycloalkyl group and aryl group in the aliphatic sulfonic acid anion and the aromatic sulfonic acid anion may have a substituent. Examples of the substituent of the alkyl group, cycloalkyl group and aryl group in the aliphatic sulfonic acid anion and the aromatic sulfonic acid anion include nitro group, halogen atom (fluorine atom, chlorine atom, bromine atom and iodine atom), carboxyl group, hydroxyl group, amino group, , An alkoxy group (preferably having 1 to 15 carbon atoms), a cycloalkyl group (preferably having 3 to 15 carbon atoms), an aryl group (preferably having 6 to 14 carbon atoms), an alkoxycarbonyl group (preferably having 2 to 7 carbon atoms, (Preferably having 2 to 12 carbon atoms), an alkoxycarbonyloxy group (preferably having 2 to 7 carbon atoms), an alkylthio group (preferably having 1 to 15 carbon atoms), an alkylsulfonyl group (preferably having 1 to 15 carbon atoms ), An alkyliminosulfonyl group (preferably having 2 to 15 carbon atoms), an aryloxysulfonyl group (preferably having 6 to 20 carbon atoms), an alkylaryloxysulfonyl group (preferably having 7 to 20 carbon atoms) An aryloxysulfonyl group (preferably having from 10 to 2 carbon atoms 0), an alkyloxyalkyloxy group (preferably having 5 to 20 carbon atoms), and a cycloalkylalkyloxyalkyloxy group (preferably having 8 to 20 carbon atoms). As the aryl group and the ring structure of each group, an alkyl group (preferably having a carbon number of 1 to 15) as a substituent may be mentioned.

Examples of the aliphatic moiety in the aliphatic carboxylic acid anion include the same alkyl group and cycloalkyl group as in the aliphatic sulfonic acid anion.

Examples of the aromatic group in the aromatic carboxylic acid anion include the same aryl group as in the aromatic sulfonic acid anion.

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

The alkyl group, cycloalkyl group, aryl group and aralkyl group in the aliphatic carboxylic acid anion, aromatic carboxylic acid anion and aralkylcarboxylic acid anion may have a substituent. Examples of the substituent of the alkyl group, cycloalkyl group, aryl group and aralkyl group in the aliphatic carboxylic acid anion, aromatic carboxylic acid anion and aralkylcarboxylic acid anion include the same halogen atoms, alkyl groups, and alkyl groups as in the aromatic sulfonic acid anion, A cycloalkyl group, an alkoxy group, an alkylthio group and the like.

The sulfonylimide anion includes, for example, a saccharin anion.

The alkyl group in the bis (alkylsulfonyl) imide anion and tris (alkylsulfonyl) methyl anion is preferably an alkyl group having 1 to 5 carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group, An isobutyl group, a sec-butyl group, a pentyl group, and a neopentyl group. Examples of the substituent of these alkyl groups include a halogen atom, an alkyl group substituted with a halogen atom, an alkoxy group, an alkylthio group, an alkyloxysulfonyl group, an aryloxysulfonyl group, and a cycloalkyl aryloxysulfonyl group. Alkyl groups are preferred.

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

Examples of the non-nucleophilic anion of Z ^- include an aliphatic sulfonic acid anion in which the alpha position of the sulfonic acid is substituted with a fluorine atom, an aromatic sulfonic acid anion substituted with a fluorine atom or a group having a fluorine atom, a bis (alkylsulfonyl) imide in which the alkyl group is substituted with a fluorine atom An anion, and a tris (alkylsulfonyl) methide anion in which the alkyl group is substituted with a fluorine atom. The non-nucleophilic anion is more preferably a perfluoro aliphatic sulfonic acid anion having 4 to 8 carbon atoms, a benzenesulfonic acid anion having a fluorine atom, still more preferably a nonafluorobutanesulfonic acid anion, a perfluorooctanesulfonic acid anion, Benzenesulfonic acid anion, and 3,5-bis (trifluoromethyl) benzenesulfonic acid anion.

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

For example, at least one of R ₂₀₁ to R ₂₀₃ of the compound represented by the general formula (ZI) is a compound represented by the general formula (ZI), or a compound represented by the general formula May be a compound having a structure bonded to at least one of R ₂₀₁ to R ₂₀₃ of one compound.

(ZI-1), (ZI-2), and (ZI-3) described below as the more preferable component (ZI).

The compound (ZI-1) is an arylsulfonium compound in which at least one of R ₂₀₁ to R ₂₀₃ in the general formula (ZI) is an aryl group, that is, a compound having an arylsulfonium cation.

Arylsulfonium compound is R ₂₀₁ ~ R ₂₀₃ are both of good and aryl contribution, R ₂₀₁ ~ R ₂₀₃ is a part of the aryl group may have an alkyl group or a cycloalkyl remaining credit.

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

The aryl group of the arylsulfonium compound is preferably a phenyl group or a naphthyl group, more preferably a phenyl group. The aryl group may be an aryl group having a heterocyclic structure having an oxygen atom, a nitrogen atom, a sulfur atom, or the like. Examples of the aryl group having a heterocyclic structure include a pyrrole residue group (a group formed by eliminating one hydrogen atom from pyrrole), a furan residue (a group formed by eliminating one hydrogen atom from furan), a thiophene residue (A group formed by elimination of one hydrogen atom from thiophene), an indole moiety (a group formed by elimination of one hydrogen atom from indole), a benzofuran moiety (a group formed by elimination of one hydrogen atom from benzofuran), benzo Thiophene residue (a group formed by eliminating one hydrogen atom from benzothiophene), and the like. When the arylsulfonium compound has two or more aryl groups, the aryl group having two or more aryl groups may be the same or different.

The alkyl group or cycloalkyl group which the arylsulfonium compound optionally has is preferably a straight chain or branched alkyl group having 1 to 15 carbon atoms and a cycloalkyl group having 3 to 15 carbon atoms, and examples thereof include methyl, ethyl, propyl, n-butyl , a sec-butyl group, a t-butyl group, a cyclopropyl group, a cyclobutyl group, and a cyclohexyl group.

R ₂₀₁ ~ aryl group, an alkyl group, a cycloalkyl group of R ₂₀₃ include an alkyl group (e.g., having from 1 to 15 carbon atoms), cycloalkyl groups (e.g. having from 3 to 15 carbon atoms), an aryl group (e.g. having 6 to 14 carbon atoms), an alkoxy Group (for example, having 1 to 15 carbon atoms), a halogen atom, a hydroxyl group, or a phenylthio group. Preferred examples of the substituent include a linear or branched alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, a linear, branched or cyclic alkoxy group having 1 to 12 carbon atoms, more preferably an alkyl group having 1 to 4 carbon atoms, 4 < / RTI > Substituent may be substituted to any one of the three R ₂₀₁ ~ R _203, may be substituted on all of three. Further, the substituent in the case where R ₂₀₁ ~ R ₂₀₃ is an aryl group substituted in the p- position of the aryl group .

Next, the compound (ZI-2) will be described.

The compound (ZI-2) is a compound in which each of R ₂₀₁ to R ₂₀₃ in the general formula (ZI) independently represents an organic group having no aromatic ring. Here, the aromatic ring includes an aromatic ring containing a hetero atom.

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

R ₂₀₁ to R ₂₀₃ each independently preferably represents an alkyl group, a cycloalkyl group, an allyl group or a vinyl group, more preferably a straight or branched 2-oxoalkyl group, a 2-oxocycloalkyl group, an alkoxycarbonylmethyl group, Is a straight chain or branched 2-oxoalkyl group.

R ₂₀₁ ~ R ₂₀₃ alkyl group and cycloalkyl group include preferably a cycloalkyl group having 1 to 10 carbon atoms, straight-chain or branched alkyl group (e.g. methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group), having from 3 to 10 carbon atoms in the (cyclo A pentyl group, a cyclohexyl group, and a norbornyl group). The alkyl group is more preferably a 2-oxoalkyl group or an alkoxycarbonylmethyl group. The cycloalkyl group is more preferably a 2-oxocycloalkyl group.

The 2-oxoalkyl group may be either straight chain or branched, and preferably a group having > C = O at two positions of the above alkyl group.

The 2-oxocycloalkyl group is preferably a group having > C = O at the 2-position of the above-mentioned cycloalkyl group.

The alkoxy group in the alkoxycarbonylmethyl group is preferably an alkoxy group having 1 to 5 carbon atoms (methoxy group, ethoxy group, propoxy group, butoxy group, pentoxy group).

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

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

In the general formula (ZI-3)

R _1c to R _5c each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group or a halogen atom.

R _6c and R _7c each independently represent a hydrogen atom, an alkyl group or a cycloalkyl group.

R _x and R _y each independently represent an alkyl group, a cycloalkyl group, an allyl group or a vinyl group.

Any two or more of R _1c to R _5c , R _6c and R _7c , and R _x and R _y may combine with each other to form a ring structure, and the ring structure may be an oxygen atom, a sulfur atom, an ester bond, May be included. _Examples of the group formed by combining any two or more of R _1c to R _5c , R _6c and R _7c , and R _x and R _y include a butylene group and a pentylene group.

Zc ^- represents an acetylenic anion and includes the same non-nucleophilic anion as Z ^- in formula (ZI).

The alkyl group as R _1c to R _7c may be either a straight chain or a branched chain, and includes, for example, an alkyl group having 1 to 20 carbon atoms, preferably a straight chain and branched alkyl group having 1 to 12 carbon atoms (for example, A propyl group, a straight chain or branched butyl group, a straight chain or branched pentyl group). Examples of the cycloalkyl group include a cycloalkyl group having 3 to 8 carbon atoms (e.g., a cyclopentyl group and a cyclohexyl group).

The alkoxy group as R _1c to R _5c may be any of linear, branched and cyclic, and includes, for example, an alkoxy group having 1 to 10 carbon atoms, preferably a straight chain and branched alkoxy group having 1 to 5 carbon atoms (for example, A straight chain or branched butoxy group, a straight chain or branched pentoxy group), and a cyclic alkoxy group having 3 to 8 carbon atoms (e.g., cyclopentyloxy group, cyclohexyloxy group).

Preferably, any one of R _1c to R _5c is a straight-chain or branched alkyl group, a cycloalkyl group or a straight-chain, branched or cyclic alkoxy group, more preferably the sum of the carbon numbers of R _1c to R _5c is 2 to 15. As a result, the solvent solubility is further improved, and the generation of particles during storage is suppressed.

The alkyl group and the cycloalkyl group as R _x and R _y include the same alkyl group and cycloalkyl group as those of R _1c to R _7c , and a 2-oxoalkyl group, a 2-oxocycloalkyl group and an alkoxycarbonylmethyl group are more preferable.

The 2-oxoalkyl group and the 2-oxocycloalkyl group include a group having > C = O at two positions of an alkyl group and a cycloalkyl group as R _1c to R _7c .

_Examples of the alkoxy group in the alkoxycarbonylmethyl group include the same alkoxy groups as those in R _1c to R _5c .

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

In the general formulas (ZII) and (ZIII)

Each of R ₂₀₄ to R ₂₀₇ independently represents an aryl group, an alkyl group or a cycloalkyl group.

The aryl group represented by R ₂₀₄ to R ₂₀₇ is preferably a phenyl group or a naphthyl group, more preferably a phenyl group. The aryl group of R ₂₀₄ to R _{207 may be} an aryl group having a heterocyclic structure having an oxygen atom, a nitrogen atom, a sulfur atom, or the like. Examples of the aryl group having a heterocyclic structure include a pyrrole residue (a group formed by eliminating one hydrogen atom from pyrrole), a furan residue (a group formed by eliminating one hydrogen atom from furan), a thiophen residue A group formed by elimination of one hydrogen atom from an indole), a benzofuran residue (a group formed by elimination of one hydrogen atom from a benzofuran), a benzothiophene residue (a benzothiophene residue) And a group formed by eliminating one hydrogen atom from benzothiophene).

The alkyl group and the cycloalkyl group for R ₂₀₄ to R ₂₀₇ are preferably a straight chain or branched alkyl group having 1 to 10 carbon atoms (for example, methyl group, ethyl group, propyl group, butyl group or pentyl group), a cycloalkyl group having from 3 to 10 carbon atoms (Cyclopentyl group, cyclohexyl group, norbornyl group).

The aryl group, alkyl group and cycloalkyl group represented by R ₂₀₄ to R ₂₀₇ may have a substituent. R ₂₀₄ ~ R ₂₀₇ may of having an aryl group, an alkyl group, a cycloalkyl group as the substituents, for example alkyl groups (e.g. having from 1 to 15 carbon atoms), cycloalkyl groups (e.g. having from 3 to 15 carbon atoms), an aryl group (e.g. An alkoxy group (for example, having from 1 to 15 carbon atoms), a halogen atom, a hydroxyl group, a phenylthio group, and the like.

Z ^- represents an acetylenic anion and includes the same as the non-nucleophilic anion of Z ^- in formula (ZI).

As the acid generator, compounds represented by the following general formulas (ZIV), (ZV) and (ZVI) can be further included.

In the general formulas (ZIV) to (ZVI)

Ar ₃ and Ar ₄ each independently represent an aryl group.

R ₂₀₈ , R ₂₀₉ and R ₂₁₀ independently represent an alkyl group, a cycloalkyl group or an aryl group.

A represents an alkylene group, an alkenylene group or an arylene group.

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

Further, as the acid generating agent, a compound which generates a sulfonic acid group or an acid having one imide group is preferable, more preferably a compound which generates a monovalent perfluoroalkanesulfonic acid, or a compound which generates a monovalent fluorine atom or a fluorine atom- Or an imidic acid substituted with a group containing a monovalent fluorine atom or a fluorine atom, and still more preferably a fluorine-substituted alkanesulfonic acid, a fluorine-substituted benzenesulfonic acid, a fluorine-substituted benzenesulfonic acid, Substituted imidic acid or a sulfonium salt of a fluorine-substituted methide acid. The acid generator which can be used is particularly preferably a fluorinated alkanesulfonic acid, a fluorinated substituted benzenesulfonic acid or a fluorinated substituted imide acid having a pKa of the generated acid of not more than -1, and the sensitivity is improved.

Among the acid generators, particularly preferred examples are shown below, but the present invention is not limited thereto.

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

The content of the acid generator in the positive photosensitive composition is preferably from 0.1 to 20 mass%, more preferably from 0.5 to 10 mass%, still more preferably from 1 to 7 mass%, based on the total solid content of the positive photosensitive composition, to be.

(B) a resin that increases the dissolution rate to an alkali developer by the action of an acid

The resin that increases the dissolution rate to an alkali developer by the action of an acid used in the positive photosensitive composition of the present invention is preferably a resin having a repeating unit (1) represented by the following general formula (I) and a -LR ₃ group (2) represents a divalent linking group having 4 to 30 carbon atoms, and R ₃ represents a hydrogen atom, a hydroxyl group or an organic group).

In the general formula (I)

Xa ₁ represents a hydrogen atom, an alkyl group, a cyano group or a halogen atom.

Ry ₁ , Ry ₂ and Rx each independently represents an alkyl group or a cycloalkyl group.

Za represents an alkylene group.

In the general formula (I), the alkyl group represented by Xa ₁ is preferably an alkyl group having 1 to 5 carbon atoms, and may be substituted with a hydroxyl group or a halogen atom.

Xa ₁ is preferably a hydrogen atom or a methyl group.

The alkyl group of Ry ₁ , Ry ₂ and Rx is preferably a linear or branched alkyl group having preferably 1 to 8 carbon atoms, more preferably 1 to 4 carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group, , A butyl group, an isobutyl group, and a t-butyl group.

The cycloalkyl group of Ry ₁ , Ry ₂ and Rx is preferably a monocyclic cycloalkyl group having 3 to 8 carbon atoms or a polycyclic cycloalkyl group having 7 to 14 carbon atoms. Examples of the preferable monocyclic cycloalkyl group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and a cyclopropyl group. Preferable examples of the polycyclic cycloalkyl group include an adamantyl group, a norbornane group, a tetracyclododecanyl group, a tricyclododecanyl group, and a diamantyl group.

Ry ₁ and Ry ₂ are preferably a methyl group or an ethyl group.

Rx is preferably an alkyl group having 2 or more carbon atoms, or a cycloalkyl group. An alkyl group having 2 or more carbon atoms, or a cycloalkyl group, the acid decomposability is improved as compared with the methyl group, and sensitivity and post-heating temperature dependency after exposure are improved.

The alkyl group and cycloalkyl group of Ry ₁ , Ry ₂ and Rx may have a substituent.

The alkylene group of Za is preferably an alkylene group having 1 to 8 carbon atoms. The alkylene group of Za may be substituted with a linking group in which a part of the methylene group has a hetero atom such as an oxygen atom, a sulfur atom, an ester group or a ketone group. Za is preferably a -CH ₂ is the alkylene group having a carbon number going from 1 to 4, particularly preferably _{-, -CH 2 CH 2 -,} -CH (CH 3) -, -C (CH 3) 2 - a. The alkylene group of Za is preferably free of acidity.

The repeating unit (1) represented by the general formula (I) may be contained in the resin of the component (B) in two or more kinds.

The polymerizable compound for forming the repeating unit (1) represented by the general formula (I) can be easily synthesized by a known method. For example, a method similar to the method described in Japanese Patent Laid-Open No. 2005-331918 is used to react an alcohol and a carboxylic acid halogenide compound under basic conditions as shown in the following formula. And then reacting this with a carboxylic acid compound under basic conditions.

Specific preferred examples of the repeating unit (1) represented by the general formula (I) are shown below, but the present invention is not limited thereto.

The repeating unit (1) is decomposed by the action of an acid to generate a carboxyl group, and the dissolution rate to the alkaline developer is increased.

The content of the repeating unit (1) is preferably 1 to 60 mol%, more preferably 1 to 50 mol%, and still more preferably 5 to 40 mol% based on the total repeating units in the polymer.

(B) has a repeating unit (2) having a -LR ₃ group (wherein L represents a divalent linking group having 4 to 30 carbon atoms, and R ₃ represents a hydrogen atom, a hydroxyl group or an organic group).

L is preferably a linear or branched alkylene group having 4 to 30 carbon atoms, more preferably a linear or branched alkylene group having 4 to 20 carbon atoms.

The alkylene group may have a structure in which an alkylene group is bonded through a structure having an oxygen atom, a sulfur atom, or an ester group in an alkylene chain, that is, an oxygen atom, a sulfur atom, or an ester group.

Examples of the divalent linking group having 4 to 30 carbon atoms for L include (-CH ₂ -) _n (wherein n represents an integer of 4 to 30), (-CH ₂ -CH (Ra) -O-) _m -La- (wherein m represents an integer of 1 to 15, Ra represents a hydrogen atom or an alkyl group (preferably a methyl group), La represents a single bond or an alkylene group (preferably 2 to 28 carbon atoms) ) And the like.

In the divalent linking group having 4 to 30 carbon atoms, the carbon atom of the ester bond is not included in the carbon number of 4 to 30.

The organic group for R ₃ may be, for example, a carboxyl group, a cycloalkyl group or the like, but a carboxyl group is particularly preferable.

The repeating unit (2) is preferably represented by the following general formula (II).

In the general formula (II)

X represents a hydrogen atom, an alkyl group, a cyano group or a halogen atom.

L represents a divalent linking group having 4 to 30 carbon atoms.

R ₃ represents a hydrogen atom, a hydroxyl group or an organic group.

The alkyl group of X is preferably an alkyl group having 1 to 5 carbon atoms, and may be substituted with a hydroxyl group or a halogen atom.

L is preferably a linear or branched alkylene group having 4 to 30 carbon atoms, more preferably a linear or branched alkylene group having 4 to 20 carbon atoms.

The alkylene group may have a structure in which an alkylene group is bonded through a structure having an oxygen atom, a sulfur atom, or an ester group in an alkylene chain, that is, an oxygen atom, a sulfur atom, or an ester group.

Examples of the divalent linking group having 4 to 30 carbon atoms for L include (-CH ₂ -) _n (wherein n represents an integer of 4 to 30), (-CH ₂ -CH (Ra) -O-) _m -La- (wherein m represents an integer of 1 to 15, Ra represents a hydrogen atom or an alkyl group (preferably a methyl group), La represents a single bond or an alkylene group (preferably 2 to 28 carbon atoms) ) And the like.

In the divalent linking group having 4 to 30 carbon atoms, the carbon atom of the ester bond is not included in the carbon number of 4 to 30.

The organic group of R ₃ includes, for example, a carboxyl group, a cycloalkyl group and the like, with a carboxyl group being particularly preferable.

Specific examples of the repeating unit (2) represented by the general formula (II) are shown below, but the present invention is not limited thereto.

The content of the repeating unit (2) is preferably 1 to 40 mol%, more preferably 1 to 30 mol%, and still more preferably 5 to 20 mol% based on the total repeating units in the polymer.

The resin of the component (B) preferably has an acid-decomposable repeating unit (3) different from the repeating unit (1).

The acid-decomposable repeating unit (3) can be used without particular limitation, but a repeating unit having a group which is desorbed by the action of an acid represented by the following general formulas (pI) to (pV) is preferable.

In the general formulas (pI) to (pV)

R ₁₁ represents an alkyl group.

Z represents an atomic group necessary for forming a cycloalkyl group together with a carbon atom.

R ₁₂ to R ₁₄ each independently represent an alkyl group or a cycloalkyl group.

R ₁₅ and R ₁₆ each independently represent an alkyl group or a cycloalkyl group.

R ₁₇ to R ₂₁ each independently represent a hydrogen atom, an alkyl group or a cycloalkyl group, and any one of R ₁₉ and R ₂₁ represents an alkyl group or a cycloalkyl group.

R ₂₂ to R ₂₅ each independently represent a hydrogen atom, an alkyl group or a cycloalkyl group, and R ₂₃ and R ₂₄ may be bonded to each other to form a ring.

In formula (pII), it is preferable that at least one of R ₁₂ to R ₁₄ is a cycloalkyl group.

It is preferable that at least one of R ₁₅ and R _{16 in} the general formula (pIII) is a cycloalkyl group.

In formula (pIV), at least one of R ₁₇ to R ₂₁ is preferably a cycloalkyl group.

In formula (pV), at least one of R ₂₂ to R ₂₅ is preferably a cycloalkyl group.

The alkyl group in the general formulas (pI) to (pV) and R ₁₁ to R ₂₅ is preferably a linear or branched alkyl group having 1 to 4 carbon atoms, and examples thereof include a methyl group, ethyl group, n- An n-butyl group, an isobutyl group, and a sec-butyl group.

The cycloalkyl group in R ₁₂ to R ₂₅ or the cycloalkyl group formed by Z and the carbon atom may be monocyclic or polycyclic. Specifically, a group having a monocyclo, bicyclo, tricyclo, tetracyclo structure or the like having 5 or more carbon atoms may be mentioned. The number of carbon atoms is preferably 5 to 30, and particularly preferably 6 to 25 carbon atoms.

Preferable examples of the cycloalkyl group include an adamantyl group, a noradamantyl group, a decalin residue, a tricyclodecanyl group, a tetracyclododecanyl group, a norbornyl group, a siderol group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, A t-butyl group, a cyclodecanyl group, and a cyclododecanyl group. More preferably an adamantyl group, a norbornyl group, a cyclohexyl group, a cyclopentyl group, a tetracyclododecanyl group and a tricyclodecanyl group.

These alkyl group and cycloalkyl group may have a new substituent. (Preferably having from 1 to 4 carbon atoms), a halogen atom, a hydroxyl group, an alkoxy group (preferably having from 1 to 4 carbon atoms), a carboxyl group, an alkoxycarbonyl group (preferably having from 2 to 6 carbon atoms), and the like . Examples of the substituent which the alkyl group, alkoxy group, alkoxycarbonyl group and the like may further have include a hydroxyl group, a halogen atom and an alkoxy group.

The groups represented by formulas (pI) to (pV) can be used to protect alkali-soluble groups to form groups (acid-decomposable groups) capable of decomposing by the action of acids to generate alkali-soluble groups. Examples of the alkali-soluble group include various groups known in the art.

Specific examples include groups in which a hydrogen atom of a carboxylic acid group, a sulfonic acid group, a phenol group or a thiol group is substituted with a group represented by any one of formulas (pI) to (pV), and preferable examples thereof include a carboxylic acid group and a sulfonic acid group A hydrogen atom is a group substituted with a group represented by the general formulas (pI) to (pV).

The repeating unit having an alkali-soluble group protected by a group represented by the general formulas (pI) to (pV) is preferably a repeating unit represented by the following general formula (III-1).

In the general formula (III-1)

R represents a hydrogen atom, a halogen atom or an alkyl group. The plural Rs may be the same or different.

A represents a single bond or a combination of two or more groups selected from the group consisting of a single bond, an alkylene group, an ether group, a thioether group, an amide group, a sulfonamide group, a urethane group or a urea group.

Rp ₁ represents any one of the groups represented by formulas (pI) to (pV).

Specific examples of the repeating unit represented by formula (III-1) are shown below, but the present invention is not limited thereto.

The acid-decomposable repeating unit (3) can also be a repeating unit represented by the following general formula (III-2).

In the general formula (III-2)

Xa ₁ represents a hydrogen atom, an alkyl group, a cyano group or a halogen atom.

Rya represents an alkyl group or a cycloalkyl group.

Z ₁ represents an atomic group necessary for forming a cycloalkyl group together with a carbon atom.

Zb represents a divalent linking group.

Xa ₁ in the formula (Ⅲ-2) is the same as Xa ₁ in the general formula (I).

Examples of the alkyl group and cycloalkyl group of Rya include the same alkyl and cycloalkyl groups as Ry ₁ , Ry ₂ and Rx in the general formula (I).

Z ₁ is the same as Z in the general formula (pI).

The divalent linking group of Zb includes a linear or branched alkylene group (preferably having 1 to 5 carbon atoms), a cycloalkylene group (preferably having 7 to 15 carbon atoms), and a combination thereof.

Specific examples of the repeating unit represented by formula (III-2) are shown below, but the present invention is not limited thereto.

The content of the acid-decomposable repeating unit (3) is preferably 0 to 60 mol%, more preferably 1 to 50 mol%, and still more preferably 5 to 40 mol% based on the total repeating units in the polymer.

The resin of the component (B) preferably has a repeating unit having a group having a lactone structure.

As the group having a lactone structure, any group can be used as far as it has a lactone structure, but preferably a group having a 5- to 7-membered cyclic lactone structure and a bicyclo structure and a spiro structure in a 5- to 7-membered cyclic lactone structure It is preferable that other ring structures are ringed. It is more preferable to have a repeating unit having a group having a lactone structure represented by any one of the following general formulas (LC1-1) to (LC1-16). The group having a lactone structure may be bonded directly to the main chain. Preferred lactone structures are (LC1-1), (LC1-4), (LC1-5), (LC1-6), (LC1-13), (LC1-14), and by using a specific lactone structure, Varnish and development defects are improved.

The lactone structure moiety may or may not have a substituent (Rb ₂ ). Preferred examples of the substituent (Rb ₂ ) include an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 4 to 7 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkoxycarbonyl group having 1 to 8 carbon atoms, a carboxyl group, a halogen atom, a hydroxyl group, And more preferably an alkyl group having 1 to 4 carbon atoms, a cyano group, and an acid-decomposable group. n2 represents an integer of 0 to 4; substituents (Rb ₂₎ to n2 is 2 or more is good when there is a plurality or different may be the same, also in combination with each other a substituent (Rb ₂₎ may be present for a plurality to form a ring.

The repeating unit having a group having a lactone structure is preferably a repeating unit (4) represented by the following general formula (IV).

In the general formula (IV)

R ₆ represents a hydrogen atom, a halogen atom or an alkyl group.

R ₇ represents a group having a lactone structure.

Ab represents a single bond, an alkylene group, a divalent linking group having a monocyclic or polycyclic alicyclic hydrocarbon structure, an ether group, an ester group, a carbonyl group, or a divalent group obtained by combining these groups.

The alkyl group of R _{6 in} the general formula (IV) is preferably an alkyl group having 1 to 4 carbon atoms, and may have a substituent. The preferable substituent which the alkyl group for R ₆ may have include hydroxyl group and halogen atom.

Examples of the halogen atom of R ₆ include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

R ₆ is preferably a hydrogen atom or a methyl group.

Ab is preferably a single bond or a linking group represented by -Ab ₁ -CO ₂ -. Ab ₁ is a linear or branched alkylene group or a monocyclic or polycyclic cycloalkylene group, preferably a methylene group, an ethylene group, a cyclohexylene group, an adamantylene group or a norbornylene group.

R ₇ is preferably a group having a structure represented by any one of formulas (LC1-1) to (LC1-16).

The repeating unit having a lactone structure usually contains an optical isomer, but all of the optical isomers may be used. In addition, one kind of optical isomer may be used alone or a plurality of optical isomers may be used in combination. When one kind of optical isomer is mainly used, the optical purity (ee) thereof is preferably 90 or more, more preferably 95 or more.

Specific examples of the repeating unit (4) are shown below, but the present invention is not limited thereto.

Particularly preferred repeating units (4) include the following repeating units. By selecting the most preferred lactone structure, the pattern profile and density dependency are improved.

The content of the repeating unit (4) is preferably 0 to 60 mol%, more preferably 1 to 50 mol%, and still more preferably 5 to 40 mol% based on the total repeating units in the polymer.

The resin of the component (B) preferably has the repeating unit (5) represented by the following general formula (V).

In the general formula (V)

R ₈ represents a hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl group.

R ₉ represents a group having an alicyclic hydrocarbon structure substituted with a hydroxyl group or a cyano group.

As the group having an alicyclic hydrocarbon structure in the general formula (V) and R ₉ , an adamantyl group, a diamantyl group and a norbornane group are preferable.

Preferred groups having an alicyclic hydrocarbon structure substituted with a hydroxyl group or a cyano group are groups represented by the following general formulas (VIIa) to (VIId).

In the general formulas (VIIa) to (VIIc)

R _2C to R _4c each independently represent a hydrogen atom hydroxyl group or cyano group. Provided that at least one of R _2C to R _4c represents a hydroxyl group or a cyano group. Preferably, one or two of R _2C to R _4c are a hydroxyl group, and the remainder is a hydrogen atom. In formula (VIIa), two of R _2C to R _4c are more preferably a hydroxyl group and the remainder are hydrogen atoms.

The content of the repeating unit (5) is preferably 0 to 40 mol%, more preferably 1 to 30 mol%, and still more preferably 5 to 25 mol% with respect to all the repeating units in the polymer.

Specific examples of the repeating unit (5) are set forth below, but the present invention is not limited thereto.

It is preferable that the resin of the component (B) has at least one kind of each of the repeating units (3) to (5) in addition to the repeating units (1) and (2).

The resin of the component (B) may have various repeating units for the purpose of controlling dry etching resistance, standard developer suitability, substrate adhesion, resist profile, resolution, heat resistance, .

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

As a result, the performance required for the resin of component (B)

(1) solubility in a coating solvent,

(2) Film formability (glass transition point),

(3) alkali developability,

(4) membrane reduction (selectable for hydrophilic, alkali soluble groups),

(5) adhesion of the unexposed portion to the substrate,

(6) Dry etching resistance

And the like can be fine-tuned.

Examples of such monomers include compounds having one addition polymerizable unsaturated bond selected from acrylic acid esters, methacrylic acid esters, acrylamides, methacrylamides, allyl compounds, vinyl ethers, vinyl esters and the like .

In addition, an addition-polymerizable unsaturated compound copolymerizable with the above-mentioned monomers corresponding to the various repeating units may be copolymerized.

The molar ratio of each repeating unit in the resin of the component (B) is suitably adjusted in order to control the dry etching resistance of the resist, the standard developer suitability, the substrate adhesion, the resist profile, and the general required performance of the resist such as resolving power, heat resistance, Respectively.

When the positive photosensitive composition of the present invention is used for ArF exposure, the resin of component (B) preferably has no aromatic group from the viewpoint of transparency to ArF light.

As the resin of component (B), preferably all of the repeating units are composed of (meth) acrylate-based repeating units. In this case, all of the repeating units may be any of methacrylate repeating units, repeating units, all of acrylate repeating units, and repeating units may be any of methacrylate repeating units / acrylate repeating units have.

The resin of the component (B) can be synthesized according to a conventional method (for example, radical polymerization). Examples of the general synthesis method include a batch polymerization method in which a monomer and a polymerization initiator are dissolved in a solvent and heated to effect polymerization, a dropwise polymerization method in which a solution of a monomer and a polymerization initiator is added dropwise to a heating solvent for 1 to 10 hours, And a dropwise polymerization method is preferable. Examples of the reaction solvent include ethers such as tetrahydrofuran, 1,4-dioxane and diisopropyl ether, ketones such as methyl ethyl ketone and methyl isobutyl ketone, esters such as ethyl acetate, dimethylformamide, dimethyl Amides such as acetamide, and solvents for dissolving the positive photosensitive composition of the present invention such as propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, and cyclohexanone described later. More preferably, the polymerization is carried out by using the same solvent as the solvent used in the positive photosensitive composition of the present invention. Thus, generation of particles during storage can be suppressed.

The polymerization reaction is preferably carried out in an inert gas atmosphere such as nitrogen or argon. As the polymerization initiator, polymerization is initiated using a commercially available radical initiator (azo initiator, peroxide, etc.). As the radical initiator, an azo-based initiator is preferable, and an azo-based initiator having an ester group, a cyano group, and a carboxyl group is preferable. Preferred initiators include azobisisobutyronitrile, azobisdimethylvaleronitrile, and dimethyl 2,2'-azobis (2-methylpropionate). A polymerization initiator is added by addition or by division as desired, and after completion of the reaction, the polymer is added to a solvent to recover a desired polymer by a method such as powder or solid recovery. The concentration of the reaction is 5 to 50 mass%, preferably 10 to 30 mass%. The reaction temperature is usually from 10 to 150 캜, preferably from 30 to 120 캜, more preferably from 60 to 100 캜.

The weight average molecular weight of the resin of component (B) is preferably 1,000 to 200,000, more preferably 3,000 to 20,000, and particularly preferably 5,000 to 15,000 in terms of polystyrene by GPC method. By setting the weight average molecular weight to 1,000 to 200,000, deterioration of heat resistance and dry etching resistance can be prevented, deterioration of developability and viscosity can be prevented, and film formability can be prevented from deteriorating.

The molecular weight distribution is usually 1 to 5, preferably 1 to 3, more preferably 1 to 2. The smaller the molecular weight distribution is, the better the resolution and the resist shape are, and the side walls of the resist pattern are smooth and the roughness is excellent.

In the positive photosensitive composition of the present invention, the amount of the resin of component (B) in the entire composition is preferably 50 to 99.99 mass%, more preferably 60 to 99.0 mass%, of the total solid content.

In the present invention, the resin of component (B) may be used singly or in combination.

(C) a dissolution control compound having a molecular weight of 3000 or less having at least one selected from an alkali-soluble group, a hydrophilic group and an acid-

A dissolution control compound having a molecular weight of 3,000 or less (hereinafter also referred to as a " dissolution control compound ") having at least one selected from an alkali-soluble group, a hydrophilic group and an acid-decomposable group may be added to the positive photosensitive composition of the present invention.

Examples of the dissolution controlling compound include compounds having an alkali-soluble group such as a carboxyl group, a sulfonylimide group, a hydroxyl group in which the α-position is substituted with a fluoroalkyl group, and the like, a compound having an alkali-soluble group such as a hydroxyl group, lactone group, cyano group, amide group, pyrrolidone group, A compound having a hydrophilic group and a compound having a group which is decomposed by the action of an acid to release an alkali-soluble group or a hydrophilic group are preferable. As the group decomposable by the action of an acid and releasing an alkali-soluble group or a hydrophilic group, a group in which a carboxyl group or a hydroxyl group is protected by a group eliminated by the action of an acid is preferable. As the dissolution control compound, it is preferable to use a compound which does not contain an aromatic ring in order not to lower the permeability of 220 nm or less, or to use a compound having an aromatic ring in an amount of 20 wt% or less based on the solid content of the composition.

Preferred dissolution control compounds include carboxylic acid compounds having an alicyclic hydrocarbon structure such as adamantane (di) carboxylic acid, norbornanecarboxylic acid, and cholic acid, compounds obtained by protecting the carboxylic acid with an acid-decomposable group, Or a compound in which the hydroxyl group is protected with an acid-decomposable group is preferable.

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

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

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

Basic compound

The positive photosensitive composition of the present invention preferably contains a basic compound in order to reduce the change in performance due to aging from exposure to heating.

The basic compound is preferably a compound having a structure represented by the following formulas (A) to (E).

In the general formulas (A) and (E)

R ²⁰⁰ , R ²⁰¹ and R ²⁰² may be the same or different and each represents a hydrogen atom, an alkyl group (preferably having 1 to 20 carbon atoms), a cycloalkyl group (preferably having 3 to 20 carbon atoms) or an aryl group (having 6 to 20 carbon atoms) Wherein R ²⁰¹ and R ²⁰² may be bonded to each other to form a ring. R ²⁰³ , R ²⁰⁴ , R ²⁰⁵ and R ²⁰⁶ may be the same or different and represent an alkyl group having 1 to 20 carbon atoms.

The alkyl group having a substituent for the alkyl group is preferably an aminoalkyl group having 1 to 20 carbon atoms, a hydroxyalkyl group having 1 to 20 carbon atoms, or a cyanoalkyl group having 1 to 20 carbon atoms.

The alkyl groups in the general formulas (A) and (E) are more preferably indeterminate.

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

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

Preferred examples of the basic compound include an amine compound having a phenoxy group, an ammonium salt compound having a phenoxy group, an amine compound having a sulfonic acid ester group, and an ammonium salt compound having a sulfonic acid ester group.

The amine compound may be a primary, secondary or tertiary amine compound, and is preferably an amine compound in which at least one alkyl group is bonded to a nitrogen atom. More preferably, the amine compound is a tertiary amine compound. When the at least one alkyl group (preferably 1 to 20 carbon atoms) is bonded to the nitrogen atom, the amine compound may contain a cycloalkyl group (preferably having 3 to 20 carbon atoms) or an aryl group (preferably 6 to 12 carbon atoms) Or may be bonded to a nitrogen atom. The amine compound preferably has an oxygen atom in the alkyl chain to form an oxyalkylene group. The number of oxyalkylene groups in the molecule is at least 1, preferably from 3 to 9, more preferably from 4 to 6. Of the oxyalkylene groups, an oxyethylene group (-CH ₂ CH ₂ O-) or an oxypropylene group (-CH (CH ₃ ) CH ₂ O- or -CH ₂ CH ₂ CH ₂ O-) is preferred, Oxyethylene group.

The ammonium salt compound may be a primary, secondary, tertiary or quaternary ammonium salt compound, and is preferably an ammonium salt compound in which at least one alkyl group is bonded to a nitrogen atom. When the at least one alkyl group (preferably having 1 to 20 carbon atoms) is bonded to the nitrogen atom, the ammonium salt compound may have a cycloalkyl group (preferably having 3 to 20 carbon atoms) or an aryl group (preferably 6 to 12 carbon atoms) Or may be bonded to an atom. The ammonium salt compound preferably has an oxygen atom in the alkyl chain and is formed with an oxyalkylene group. The number of oxyalkylene groups in the molecule is at least 1, preferably from 3 to 9, more preferably from 4 to 6. Among oxyalkylene groups, an oxyethylene group (-CH ₂ CH ₂ O-) or an oxypropylene group (-CH (CH ₃ ) CH ₂ O- or -CH ₂ CH ₂ CH ₂ O-) is preferable, Oxyethylene group.

Examples of the anion of the ammonium salt compound include a halogen atom, a sulfonate, a borate, and a phosphate. Among them, a halogen atom and a sulfonate are preferable. The halogen atom is particularly preferably chloride, bromide or iodide, and as the sulfonate, an organic sulfonate having 1 to 20 carbon atoms is particularly preferable. Examples of the organic sulfonate include an alkylsulfonate having 1 to 20 carbon atoms and an arylsulfonate. The alkyl group of the alkylsulfonate may have a substituent, and examples of the substituent include fluorine, chlorine, bromine, an alkoxy group, an acyl group, and an aryl group. Specific examples of the alkylsulfonate include methanesulfonate, ethanesulfonate, butanesulfonate, hexanesulfonate, octanesulfonate, benzylsulfonate, trifluorosulfonate, pentafluorosulfonate, nonafluorobutanesulfonate, etc. . The aryl group of the arylsulfonate includes a benzene ring, a naphthalene ring and an anthracene ring. The benzene ring, naphthalene ring and anthracene ring may have a substituent, and the substituent is preferably a straight chain or branched alkyl group having 1 to 6 carbon atoms or a cycloalkyl group having 3 to 6 carbon atoms. Specific examples of the linear or branched alkyl group and the cycloalkyl group include methyl, ethyl, n-propyl, isopropyl, n-butyl, i-butyl, t-butyl, n-hexyl and cyclohexyl. Examples of other substituents include an alkoxy group having 1 to 6 carbon atoms, a halogen atom, a cyano group, a nitro group, an acyl group, and an acyloxy group.

The amine compound having a phenoxy group and the ammonium salt compound having a phenoxy group are those having a phenoxy group at the terminal on the opposite side to the nitrogen atom of the alkyl group of the amine compound or the ammonium salt compound. The phenoxy group may have a substituent. Examples of the substituent of the phenoxy group include an alkyl group, an alkoxy group, a halogen atom, a cyano group, a nitro group, a carboxyl group, a carboxylic acid ester group, a sulfonic ester group, an aryl group, an aralkyl group, an acyloxy group, . The substitution position of the substituent may be any of 2-6 positions. The number of substituents may be in the range of 1 to 5.

It is preferable that at least one oxyalkylene group is present between the phenoxy group and the nitrogen atom. The number of oxyalkylene groups in the molecule is at least 1, preferably from 3 to 9, more preferably from 4 to 6. Among oxyalkylene groups, an oxyethylene group (-CH ₂ CH ₂ O-) or an oxypropylene group (-CH (CH ₃ ) CH ₂ O- or -CH ₂ CH ₂ CH ₂ O-) is preferable, Oxyethylene group.

The sulfonic acid ester group in the amine compound having a sulfonic acid ester group and the ammonium salt compound having a sulfonic acid ester group may be any of an alkylsulfonic acid ester, a cycloalkyl group sulfonic acid ester and an arylsulfonic acid ester. In the case of an alkylsulfonic acid ester, , The cycloalkyl group has 3 to 20 carbon atoms in the case of the cycloalkyl sulfonic acid ester and the aryl group has 6 to 12 carbon atoms in the case of the aryl sulfonic acid ester. The alkylsulfonic acid ester, the cycloalkylsulfonic acid ester and the arylsulfonic acid ester may have a substituent, and as the substituent, a halogen atom, cyano group, nitro group, carboxyl group, carboxylic acid ester group or sulfonic acid ester group is preferable.

And at least one oxyalkylene group is present between the sulfonate ester group and the nitrogen atom. The number of oxyalkylene groups in the molecule is at least 1, preferably from 3 to 9, more preferably from 4 to 6. Among oxyalkylene groups, an oxyethylene group (-CH ₂ CH ₂ O-) or an oxypropylene group (-CH (CH ₃ ) CH ₂ O- or -CH ₂ CH ₂ CH ₂ O-) is preferable, Oxyethylene group.

These basic compounds are used alone or in combination of two or more.

The amount of the basic compound to be used is usually 0.001 to 10 mass%, preferably 0.01 to 5 mass%, based on the solid content of the positive photosensitive composition.

The ratio of the acid generator to the basic compound in the composition is preferably from 2.5 to 300 as the acid generator / basic compound (molar ratio). That is, the molar ratio is preferably 2.5 or more from the viewpoints of sensitivity and resolution, and is preferably 300 or less from the viewpoint of suppressing reduction in resolution due to thickening of the resist pattern with time after exposure to heat treatment. The acid generator / basic compound (molar ratio) is more preferably 5.0 to 200, and still more preferably 7.0 to 150.

(E) a fluorine- and / or silicon-based surfactant

The positive photosensitive composition of the present invention may also contain one or more of fluorine and / or silicon surfactants (fluorine surfactants, silicon surfactants, and surfactants having both fluorine and silicon atoms) desirable.

When the positive photosensitive composition of the present invention contains a fluorine- and / or silicon-based surfactant, a resist pattern with good sensitivity and resolution and excellent adhesion and defects at the time of using an exposure light source of 250 nm or less, particularly 220 nm or less, Lt; / RTI >

As the fluorine- and / or silicon-based surfactants, there are, for example, JP-A-62-36663, JP-A-61-226746, JP-A-61-226745, JP-A-62-170950 Japanese Patent Application Laid-Open Nos. 63-34540, 7-230165, 8-62834, 9-54432, 9-5988 Japanese Patent Application Laid-Open No. 2002-277862, U.S. Patent No. 5,405,720, U.S. Patent No. 5360692, U.S. Patent No. 5529881, U.S. Patent No. 5296330, U.S. Patent No. 5436098, U.S. Patent No. 5576143, U.S. Patent No. 5294511 A surfactant described in JP 5824451 A may be mentioned, and the following surfactants commercially available may be used as they are.

Examples of commercially available surfactants that can be used include surfactants such as EFTOP EF301 and EF303 (manufactured by Shin-Akita Kasei Corporation), Fluorad FC430 and 431 (manufactured by Sumitomo 3M Ltd.), Megafac F176, F189 and R08 (Manufactured by Asahi Glass Co., Ltd.), Troisol S-366 (manufactured by Troy Chemical Co., Ltd.), Surfron S-382, SC101, 102, 103, Based surfactant or silicon-based surfactant. Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) is also used as a silicon-based surfactant.

In addition to the known surfactants described above, the surfactant may be a fluorine-containing compound derived from a fluoroaliphatic compound produced by a telomerization method (also referred to as a telomer method) or an oligomerization method (also referred to as an oligomer method) A surfactant using a polymer having an aliphatic group can be used. The fluoroaliphatic compound can be synthesized by the method described in JP-A-2002-90991.

As the polymer having a fluoroaliphatic group, a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate and / or (poly (oxyalkylene)) methacrylate is preferable and even if distributed irregularly It may be good and block copolymerized. Examples of the poly (oxyalkylene) group include a poly (oxyethylene) group, a poly (oxypropylene) group and a poly (oxybutylene) group. In addition, poly (oxyethylene, oxypropylene and oxyethylene blocks Or may be a unit having alkylene chains of different chain lengths in the same chain length, such as poly (block-linking structure of oxyethylene and oxypropylene). Further, a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate (or methacrylate) may be a monomer having two or more different fluoroaliphatic groups as well as a binary copolymer, (Poly (oxyalkylene)) acrylate (or methacrylate) copolymerized at the same time may be used.

Examples of commercially available surfactants include Megapac F178, F-470, F-473, F-475, F-476 and F-472 (manufactured by Dainippon Ink and Chemicals, Inc.). In addition, C ₆ F acrylate having ₁₃ groups (or methacrylate) with (poly (oxyalkylene)) acrylate (or methacrylate) copolymer, C ₆ acrylate having F ₁₃ an acrylate (or methacrylate of ) And copolymers of (poly (oxyethylene)) acrylate (or methacrylate) and (poly (oxypropylene)) acrylate (or methacrylate), acrylates having C ₈ F ₁₇ groups (or methacrylates ) and a (poly (oxyalkylene)) acrylate (or methacrylate acrylate having a copolymer, C ₈ F ₁₇ group of the acrylate) (or methacrylate) with (poly (oxyethylene)) acrylate (or methacrylate (Copolymer) of (poly (oxypropylene)) acrylate (or methacrylate) and the like.

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

Organic solvent

The positive photosensitive composition of the present invention is used by dissolving each component in a predetermined organic solvent.

Examples of the organic solvent that can be used include organic solvents such as ethylene dichloride, cyclohexanone, cyclopentanone, 2-heptanone,? -Butyrolactone, methyl ethyl ketone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 2- Propyleneglycol monomethyl ether acetate, toluene, ethyl acetate, methyl lactate, ethyl lactate, methyl methoxypropionate, ethyl ethoxypropionate, methyl pyruvate, methyl pyruvate, ethyl lactate, , Ethyl pyruvate, propyl pyruvate, N, N-dimethyl formamide, dimethyl sulfoxide, N-methyl pyrrolidone, tetrahydrofuran and the like.

In the present invention, the organic solvent may be used alone or in combination, but it is preferable to use a mixed solvent containing two or more kinds of solvents having different functional groups. As a result, the solubility of the material is improved, the generation of particles in a long time can be suppressed, the occurrence of defects at the time of coating can be suppressed, and a good pattern profile can be obtained. Preferable functional groups of the solvent include an ester group, a lactone group, a hydroxyl group, a ketone group, and a carbonate group. As the mixed solvent having another functional group, the following mixed solvents of (S1) to (S5) are preferable.

(S1) a mixed solvent obtained by mixing a solvent having a hydroxyl group and a solvent having no hydroxyl group,

(S2) a mixed solvent obtained by mixing a solvent having an ester structure and a solvent having a ketone structure,

(S3) a mixed solvent obtained by mixing a solvent having an ester structure and a solvent having a lactone structure,

(S4) a mixed solvent obtained by mixing a solvent having an ester structure, a solvent having a lactone structure, and a solvent having a hydroxyl group,

(S5) A mixed solvent obtained by mixing a solvent having an ester structure, a solvent having a carbonate structure, and a solvent having a hydroxyl group.

Examples of the solvent having a hydroxyl group include ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether and ethyl lactate. Among them, propylene glycol Monomethyl ether and ethyl lactate are particularly preferable.

Examples of the solvent having no hydroxyl group include propylene glycol monomethyl ether acetate, ethyl ethoxypropionate, 2-heptanone,? -Butyrolactone, cyclohexanone, butyl acetate, N-methylpyrrolidone, Propyleneglycol monomethyl ether acetate, ethyl ethoxypropionate, 2-heptanone,? -Butyrolactone, cyclohexanone, and butyl acetate are preferable And propylene glycol monomethyl ether acetate, ethyl ethoxypropionate, 2-heptanone, and cyclohexanone are more preferable.

Examples of the solvent having a ketone structure include cyclohexanone, 2-heptanone and the like, preferably cyclohexanone.

Examples of the solvent having an ester structure include propylene glycol monomethyl ether acetate, ethyl ethoxypropionate and butyl acetate, and propylene glycol monomethyl ether acetate is preferable.

The solvent having a lactone structure includes, for example,? -Butyrolactone.

As the solvent having a carbonate structure, for example, propylene carbonate, ethylene carbonate and the like can be given, and propylene carbonate is preferable.

The mixing ratio (mass) of the solvent having a hydroxyl group to the solvent having no hydroxyl group is usually from 1/99 to 99/1, preferably from 10/90 to 90/10, more preferably from 20/80 to 60/40. A mixed solvent containing 50 mass% or more of a solvent having no hydroxyl group is particularly preferable in view of coating uniformity.

The mixing ratio (mass) of the solvent having the ester structure to the solvent having the ketone structure is usually from 1/99 to 99/1, preferably from 10/90 to 90/10, more preferably from 40/60 to 80/20. A mixed solvent containing 50 mass% or more of a solvent having an ester structure is particularly preferable from the viewpoint of coating uniformity.

The mixing ratio (mass) of the solvent having an ester structure to the solvent having a lactone structure is usually 70/30 to 99/1, preferably 80/20 to 99/1, more preferably 90/10 to 99/1. A mixed solvent containing 70% by mass or more of a solvent having an ester structure is particularly preferable from the viewpoint of stability with time.

When mixing a solvent having an ester structure, a solvent having a lactone structure, and a solvent having a hydroxyl group, the solvent having an ester structure is contained in an amount of 30 to 80 mass%, the solvent having a lactone structure is contained in an amount of 1 to 20 mass% By mass to 10% by mass to 60% by mass.

When a solvent having an ester structure, a solvent having a carbonate structure and a solvent having a hydroxyl group are mixed, the solvent having an ester structure is contained in an amount of 30 to 80 mass%, the solvent having a carbonate structure is contained in an amount of 1 to 20 mass% By mass to 10% by mass to 60% by mass.

(Pattern forming method)

The positive photosensitive composition of the present invention is prepared by dissolving each component in a predetermined organic solvent, preferably the above-mentioned mixed solvent, filtering the solution, and applying the solution on a predetermined support. The filter used for filter filtration is preferably made of polytetrafluoroethylene, polyethylene, or nylon, preferably 0.1 micron or less, more preferably 0.05 micron or less, and even more preferably 0.03 micron or less.

The positive photosensitive composition is applied on a substrate (for example, silicon / silicon dioxide coated) used for the production of precision integrated circuit elements at an arbitrary thickness (usually 50 to 500 nm) by a suitable coating method such as a spinner or a coater. After coating, the resist film is dried by spinning or baking to form a resist film. The baking temperature can be appropriately set, but is usually 60 to 150 ° C, preferably 90 to 130 ° C.

Subsequently, the resist is exposed through a mask or the like for pattern formation.

The exposure dose can be appropriately set, but is usually 1 to 100 mJ / cm 2. After exposure, it is preferable to perform spinning and / or baking as it is, and development and rinsing are carried out to obtain a pattern.

(Liquid immersion exposure) may be performed by filling a liquid (immersion medium) having a refractive index higher than that of air between the photosensitive film and the lens during the irradiation of the actinic ray or radiation. As a result, resolution can be improved. As the immersion medium to be used, any liquid can be used as long as it has a refractive index higher than that of air, but it is preferably pure water. In addition, an overcoat layer may be further formed on the photosensitive film so that the immersion medium and the photosensitive film are not in direct contact with each other when the immersion exposure is performed. As a result, the elution of the composition from the photosensitive film into the immersion medium is suppressed, and development defects are reduced.

Examples of the actinic ray or radiation include infrared light, visible light, ultraviolet light, extraneous light, X-ray, electron beam and the like, but preferably at least 250 nm, more preferably at most 220 nm, An ArF excimer laser, an F ₂ excimer laser, an EUV (13 nm), and an electron beam are preferably used as the excimer laser (248 nm), ArF excimer laser (193 nm), F ₂ excimer laser Do.

An antireflection film may be applied in advance on the substrate before forming the photosensitive film.

As the antireflection film, for example, an inorganic film type such as titanium, titanium dioxide, titanium nitride, chromium oxide, carbon, amorphous silicon and the like, and an organic film type comprising a light absorber and a polymer material can be used. As the organic antireflection film, a commercially available organic antireflection film such as DUV30 series manufactured by Brewers Science, DUV-40 series, and AR-2, AR-3, AR-5 manufactured by Shipley may be used.

In the development process, an alkaline developer is used. Examples of the alkali developing solution include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate and ammonia water, primary amines such as ethylamine and n-propylamine, Tertiary amines such as triethylamine, methyldiethylamine, etc .; alcohol amines such as dimethylethanolamine and triethanolamine; tertiary amines such as tetramethylammonium hydroxide and tetraethylammonium hydroxide; Cyclic amines such as acylammonium salts, pyrrole and piperidine, and the like can be used.

In addition, an appropriate amount of an alcohol or a surfactant may be added to the alkali developing solution.

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

The pH of the alkaline developer is usually 10.0 to 15.0.

In the resist pattern forming method of the present invention, a thermal flow process can be performed after forming a resist pattern.

The thermal flow process can be performed, for example, as follows.

That is, the pattern size of the resist pattern (for example, the hole diameter of the hole pattern or the space width of the line and space) can be increased by heating the resist pattern after development processing by heating at least once, preferably 2 to 3 times, (Narrower) than the size immediately after the development.

The preferred heating temperature depends on the composition of the positive photosensitive composition and is not particularly limited as long as it is not lower than the softening point of the resist pattern, but is preferably in the range of 80 to 180 占 폚, more preferably 110 to 170 占 폚, Is 130 to 170 ° C. When the heating temperature is within this range, it is advantageous to suppress the pattern size easily, and it is easy to use in existing devices.

The preferable heating time is not particularly limited as long as the throughput is not hindered and the desired pattern size can be obtained. Judging from the usual production line process of a semiconductor device, 300 seconds, and more preferably 30 to 180 seconds.

The positive photosensitive composition of the present invention may be applied to an upper-layer resist layer of a multilayer resist process (particularly, a three-layer resist process). The multilayer resist method includes the following processes.

(a) A lower layer resist layer made of an organic material is formed on a substrate to be processed.

(b) An intermediate layer and an upper-layer resist layer are sequentially laminated on the lower-layer resist layer.

(c) After forming a predetermined pattern on the upper resist layer, the intermediate layer, the lower layer and the substrate are sequentially etched.

As the intermediate layer, organopolysiloxane (silicone resin) or SiO ₂ coating liquid (SOG) is generally used. As the lower layer resist, a suitable organic polymer film is used, but various known photoresists may be used. For example, each series of FH series, FHi series manufactured by Fuji Film Arch Co., Ltd. or PFI series manufactured by Sumitomo Chemical Co., Ltd. can be exemplified.

The film thickness of the lower layer resist layer is preferably 0.1 to 4.0 탆, more preferably 0.2 to 2.0 탆, and particularly preferably 0.25 to 1.5 탆. The thickness of 0.1 mu m or more is preferable from the viewpoints of antireflection and dry etching resistance, and the thickness of 4.0 mu m or less is preferable from the viewpoint of the aspect ratio and the pattern collapse of the formed fine pattern.

[Example]

Hereinafter, the present invention will be described by way of examples, but the present invention is not limited thereto.

(Synthesis Example 1)

43 g of cyclohexanone in a nitrogen stream was charged into a three-necked flask, which was heated to 80 캜. 6.8 g of? -Butyrolactone methacrylate, 2.36 g of 3-hydroxyadamantyl-1-methacrylate, 12.8 g of the following monomer (A), 1.88 g of methoxyethoxyethyl methacrylate, -601 (manufactured by Wako Pure Chemical Industries, Ltd.) in an amount of 4.5 mol% based on the monomer and 82 g of cyclohexanone was added dropwise over 6 hours. After completion of the addition, the reaction was further carried out at 80 DEG C for 2 hours. The reaction solution was allowed to cool and then added dropwise to a mixed solution of 900 ml of methanol / 100 ml of water over 20 minutes. The precipitated powder was collected by filtration and dried to obtain 20 g of Resin (P-1). The obtained resin (P-1) had a weight average molecular weight of 11000 in terms of standard polystyrene and a degree of dispersion (Mw / Mn) of 1.65.

Other resins (P-2) to (P-16) were also synthesized by the same method. The weight average molecular weight was adjusted by changing the amount of the polymerization initiator.

The structures of the resins (P-1) to (P-16) are shown below.

(Examples 1 to 14 and Comparative Examples 1 and 2)

<Preparation of Resist>

The components shown in the following Table 1 were dissolved in a solvent to prepare a solution having a solid content concentration of 5% by mass. The solution was filtered with a polyethylene filter having a pore size of 0.03 탆 to prepare a positive resist solution. The prepared positive resist solution was evaluated by the following method, and the results are also shown in Table 1.

&Lt; Evaluation of resist &

An organic antireflection film ARC29A (manufactured by Nissan Kagaku) was applied onto a silicon wafer and baked at 205 deg. C for 60 seconds to form an antireflection film having a thickness of 78 nm. A positive resist composition prepared thereon was applied and baked at 110 DEG C for 60 seconds to form a resist film having a thickness of 160 nm. The obtained wafer was subjected to pattern exposure using an ArF excimer laser scanner (PAS 5500/1100 manufactured by ASML, NA 0.75, Annular (σo / σi = 0.89 / 0.65)). Thereafter, the resist film was heated at 110 DEG C for 60 seconds, developed with a tetramethylammonium hydroxide aqueous solution (2.38 mass%) for 30 seconds, rinsed with pure water and then spin-dried to obtain a resist pattern.

Pattern collapse evaluation method:

The linewidth was defined as the line width at which the pattern was not collapsed when the line width of the line pattern formed by further increasing the exposure amount from the optimum exposure amount was made the optimum exposure amount for reproducing the mask pattern of 85 nm line and space. A smaller value indicates that a finer pattern is resolved without collapsing, indicating that pattern collapse is unlikely to occur.

Evaluation of exposure latitude:

An exposure amount for reproducing a mask pattern of 85 nm line and space was regarded as an optimum exposure amount and an exposure amount width allowing a pattern size of 85 nm ± 10% when the exposure amount was changed was obtained and this value was divided by the optimum exposure amount to display a percentage . The larger the value, the smaller the performance change due to the change in exposure amount and the better the exposure latitude.

Line edge roughness evaluation method:

The line edge roughness was measured by observing an isolated pattern of 120 nm using a scanning electron microscope (SEM) and measuring the distance from the reference line where the edges in the longitudinal direction of the line pattern should be 5 占 퐉 Measurement was made at 50 points by a measurement SEM (S-9260 Hitachi Seisakusho Co., Ltd.), and the standard deviation was calculated to calculate 3σ. The smaller the value, the better the performance.

Evaluation method of thermal flow aptitude:

A pattern of 85 nm line and space was formed and baked at 150 ° C, 160 ° C, and 170 ° C for 90 seconds, respectively, and the shrinkage of the line width was measured by a measurement SEM (Hitachi Seisakusho S-9260). ◎ at 160 ° C, △ at 170 ° C, 10% or more shrinkage at 170 ° C than the original linewidth. And the case where it was not supported was called "×".

The abbreviations in the table are shown below.

[Acid generator]

[Basic compound]

TPSA: Triphenylsulfonium acetate

DIA: 2,6-diisopropylaniline

TEA: triethanolamine

DBA: N, N-dibutyl aniline

PBI: 2-phenylbenzimidazole

TMEA: Tris (methoxyethoxyethyl) amine

PEA: N-phenyldiethanolamine

PBMA: 2- [2- {2- (2,2-dimethoxy-phenoxyethoxy) ethyl} -bis- (2-methoxyethyl)

〔Surfactants〕

W-1: Megafac F176 (manufactured by Dainippon Ink and Chemicals, Incorporated) (fluorine-based)

W-2: Megapack R08 (manufactured by Dainippon Ink &amp; Chemicals, Inc.) (fluorine and silicon)

W-3: Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) (silicon-based)

W-4: Troizol S-366 (manufactured by Troy Chemical)

〔solvent〕

S1: Propylene glycol methyl ether acetate

S4:? -Butyrolactone

S5: Propylene glycol methyl ether

S6: Ethyl lactate

From Table 1, it can be seen that the positive photosensitive composition of the present invention is excellent in pattern collapse, exposure latitude, line edge roughness and thermal flow evaluation.

(Example 15)

<Preparation of Resist>

0.05 g of the following polymer (A) was further added to the component of Example 1 to prepare a solution having a solid content concentration of 5% by mass. The solution was filtered with a polyethylene filter having a pore size of 0.1 탆 to prepare a positive resist solution. The prepared positive resist solution was evaluated by the following method.

&Lt; Evaluation of resolution >

An organic antireflection film ARC29A (manufactured by Nissan Kagaku) was applied onto a silicon wafer and baked at 205 DEG C for 60 seconds to form an antireflection film having a thickness of 78 nm. A positive resist solution prepared thereon was applied and baked at 110 DEG C for 60 seconds to form a resist film having a film thickness of 160 nm.

The wafer thus obtained was subjected to pattern exposure using an ArF excimer laser immersion scanner (NA 0.75). Ultrapure water having an impurity of 5 ppb or less was used as the immersion liquid. Immediately after exposure, the resist pattern was heated at 115 占 폚 for 90 seconds, developed with tetramethylammonium hydroxide aqueous solution (2.38%) for 60 seconds, rinsed with pure water and then spin dried. The resist pattern was observed under a scanning electron microscope (S-926.0 ). As a result, a line and space pattern of 65 nm was resolved.

The positive photosensitive composition of the present invention had a good image forming ability even in the exposure method through an immersion liquid.

Claims (20)

(A) a compound which generates an acid upon irradiation with an actinic ray or radiation; And (B) a polymer having a repeating unit (1) represented by the following general formula (I) and a repeating unit (2) represented by the following general formula (II) different from the above-mentioned repeating unit (1) Wherein the positive photosensitive composition contains a resin that increases the dissolution rate with respect to the developer.

In the general formula (I) Xa ₁ represents a hydrogen atom, an alkyl group, a cyano group or a halogen atom. Ry ₁ , Ry ₂ and Rx each independently represents an alkyl group or a cycloalkyl group. Za represents an alkylene group.

L represents a linear or branched alkylene group having 4 to 30 carbon atoms, R ₃ represents a hydrogen atom, a hydroxyl group, a carboxyl group or a cycloalkyl group, and X represents a hydrogen atom, an alkyl group, a cyano group or a halogen atom. The positive photosensitive composition according to claim 1, wherein R _{3 in the} formula (II) is a carboxyl group or a cycloalkyl group. (A) a compound which generates an acid upon irradiation with an actinic ray or radiation; And (B) a repeating unit (1) represented by the following general formula (I ') and a -LR ₃ group (wherein L represents a divalent linking group having 4 to 30 carbon atoms, R ₃ represents a hydrogen atom, a hydroxyl group, A repeating unit (2) having a repeating unit represented by the following formula (1): wherein R 1 and R 2 each independently represent a hydrogen atom, a cycloalkyl group, and the like.

In the general formula (I '), Xa ₁ represents a hydrogen atom, an alkyl group, a cyano group or a halogen atom. Ry ₁ and Ry ₂ each independently represent an alkyl group or a cycloalkyl group. Rx 'represents an alkyl group having 2 or more carbon atoms or a cycloalkyl group. Provided that the alkyl group as Rx 'is unsubstituted alkyl. Za 'represents an unsubstituted alkylene group having 1 to 4 carbon atoms. (A) a compound which generates an acid upon irradiation with an actinic ray or radiation; And (B) a repeating unit (1) represented by the following general formula (I) and a -LR ₃ group (wherein L represents a divalent linking group having 4 to 30 carbon atoms, R ₃ represents a hydrogen atom, a hydroxyl group, a carboxyl group or a cyclo (2) having a repeating unit represented by the following formula (1) or (2), wherein the dissolution rate of the repeating unit (2) in an alkali developer is increased by the action of an acid. Wherein the resin further contains a resin having a repeating unit represented by the following formula (A) different from the resin of the component (B).

In the general formula (I) Xa ₁ represents a hydrogen atom, an alkyl group, a cyano group or a halogen atom. Ry ₁ , Ry ₂ and Rx each independently represents an alkyl group or a cycloalkyl group. Za represents an alkylene group. (A) a compound which generates an acid upon irradiation with an actinic ray or radiation; And (B) a repeating unit (1) represented by the following general formula (I) and a -LR ₃ group (wherein L represents a divalent linking group having 4 to 30 carbon atoms, R ₃ represents a hydrogen atom, a hydroxyl group, a carboxyl group or a cyclo (2) having a repeating unit represented by the following formula (1) or (2), wherein the dissolution rate of the repeating unit (2) in an alkali developer is increased by the action of an acid. Wherein the resin of the component (B) has at least two kinds of the repeating unit (1) represented by the general formula (I).

In the general formula (I) Xa ₁ represents a hydrogen atom, an alkyl group, a cyano group or a halogen atom. Ry ₁ , Ry ₂ and Rx each independently represents an alkyl group or a cycloalkyl group. Za represents an alkylene group. (A) a compound which generates an acid upon irradiation with an actinic ray or radiation; And (B) a repeating unit (1) represented by the following general formula (I) and a -LR ₃ group (wherein L represents a divalent linking group having 4 to 30 carbon atoms, R ₃ represents a hydrogen atom, a hydroxyl group, a carboxyl group or a cyclo (2) represented by the following general formula (III-2) and an acid-decomposable repeating unit (3) represented by the following general formula (III-2) and having a dissolution rate to an alkali developer By weight based on the total weight of the positive photosensitive composition.

In the general formula (I) Xa ₁ represents a hydrogen atom, an alkyl group, a cyano group or a halogen atom. Ry ₁ , Ry ₂ and Rx each independently represents an alkyl group or a cycloalkyl group. Za represents an alkylene group.

In the general formula (III-2) Xa ₁ represents a hydrogen atom, an alkyl group, a cyano group or a halogen atom. Rya represents an alkyl group or a cycloalkyl group. Z ₁ represents an atomic group necessary for forming a cycloalkyl group together with a carbon atom. Zb represents a divalent linking group. (A) a compound which generates an acid upon irradiation with an actinic ray or radiation; And (B) a repeating unit (1) represented by the following general formula (I) and a -LR ₃ group (wherein L represents a divalent linking group having 4 to 30 carbon atoms, R ₃ represents a hydrogen atom, a hydroxyl group, a carboxyl group or a cyclo A repeating unit (2) having an alkyl group, (4) represented by the following general formula (IV) and a repeating unit (5) represented by the following general formula (V), wherein the repeating unit (1) A positive photosensitive composition comprising a resin that increases the dissolution rate with respect to an alkali developer by the action of an acid, Wherein the resin of the component (B) has at least one or more kinds of each of the repeating units (1) to (5).

In the general formula (I) Xa ₁ represents a hydrogen atom, an alkyl group, a cyano group or a halogen atom. Ry ₁ , Ry ₂ and Rx each independently represents an alkyl group or a cycloalkyl group. Za represents an alkylene group.

In the general formula (IV) R ₆ represents a hydrogen atom, a halogen atom or an alkyl group. R ₇ represents a group having a lactone structure. Ab represents a single bond, an alkylene group, a divalent linking group having a monocyclic or polycyclic alicyclic hydrocarbon structure, an ether group, an ester group, a carbonyl group, or a divalent group obtained by combining these groups.

In the general formula (V) R ₈ represents a hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl group. R ₉ represents a group having an alicyclic hydrocarbon structure substituted with a hydroxyl group or a cyano group. The positive photosensitive composition according to any one of claims 1 to 5, wherein the resin of the component (B) further comprises an acid-decomposable repeating unit (3) different from the repeating unit (1). The positive photosensitive composition according to claim 8, wherein the acid-decomposable repeating unit (3) has any one of groups eliminated by the action of an acid represented by the following general formulas (pI) to (pV).

In the general formulas (pI) to (pV) R ₁₁ represents an alkyl group. Z represents an atomic group necessary for forming a cycloalkyl group together with a carbon atom. R ₁₂ to R ₁₄ each independently represent an alkyl group or a cycloalkyl group. R ₁₅ and R ₁₆ each independently represent an alkyl group or a cycloalkyl group. R ₁₇ to R ₂₁ each independently represent a hydrogen atom, an alkyl group or a cycloalkyl group, and any one of R ₁₉ and R ₂₁ represents an alkyl group or a cycloalkyl group. R ₂₂ to R ₂₅ each independently represent a hydrogen atom, an alkyl group or a cycloalkyl group, and R ₂₃ and R ₂₄ may be bonded to each other to form a ring. The positive photosensitive composition according to claim 9, wherein the acid-decomposable repeating unit (3) is represented by the following general formula (III-1).

In the general formula (III-1) R represents a hydrogen atom, a halogen atom or an alkyl group. The plural Rs may be the same or different. A represents a single bond or a combination of two or more groups selected from the group consisting of a single bond, an alkylene group, an ether group, a thioether group, an amide group, a sulfonamide group, a urethane group or a urea group. Rp ₁ represents any one of the groups represented by formulas (pI) to (pV). The positive photosensitive composition according to any one of claims 1 to 6, wherein the resin (B) further comprises a repeating unit (4) represented by the following general formula (IV).

In the general formula (IV) R ₆ represents a hydrogen atom, a halogen atom or an alkyl group. R ₇ represents a group having a lactone structure. Ab represents a single bond, an alkylene group, a divalent linking group having a monocyclic or polycyclic alicyclic hydrocarbon structure, an ether group, an ester group, a carbonyl group, or a divalent group obtained by combining these groups. The positive photosensitive composition according to any one of claims 1 to 6, wherein the resin of the component (B) further has a repeating unit (5) represented by the following general formula (V).

In the general formula (V) R ₈ represents a hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl group. R ₉ represents a group having an alicyclic hydrocarbon structure substituted with a hydroxyl group or a cyano group. The positive photosensitive resin composition according to any one of claims 1 to 7, wherein the content of the repeating unit (1) is 5 to 40 mol% based on the total repeating units in the resin of the component (B) Composition. The positive photosensitive resin composition according to any one of claims 1 to 7, wherein the content of the repeating unit (2) is 1 to 40 mol% based on the total repeating units in the resin of the component (B) Composition. The positive photosensitive composition according to any one of claims 1 to 7, further comprising a mixed solvent selected from the following (S1) to (S5). (S1) a mixed solvent obtained by mixing a solvent having a hydroxyl group and a solvent having no hydroxyl group, (S2) a mixed solvent obtained by mixing a solvent having an ester structure and a solvent having a ketone structure, (S3) a mixed solvent obtained by mixing a solvent having an ester structure and a solvent having a lactone structure, (S4) a mixed solvent obtained by mixing a solvent having an ester structure, a solvent having a lactone structure, and a solvent having a hydroxyl group, (S5) A mixed solvent obtained by mixing a solvent having an ester structure, a solvent having a carbonate structure, and a solvent having a hydroxyl group. The positive photosensitive composition according to any one of claims 1 to 7, wherein the amount of the resin of the component (B) in the total composition is 60 to 99.0 mass% of the total solid content. The positive photosensitive composition according to any one of claims 1 to 7, wherein the resin of component (B) has no aromatic group. A resist film formed by the positive photosensitive composition according to any one of claims 1 to 7. 18. A pattern forming method, comprising: forming a resist film according to claim 18; and exposing and developing the film. The pattern forming method according to claim 19, wherein the exposure is a liquid immersion exposure.