KR20090019731A - Positive type photosensitive composition and pattern formation method using the same - Google Patents

Abstract

A positive photosensitive composition, and a method for forming a pattern by using the composition are provided to improve pattern collapse, exposure latitude and line edge roughness when a micropattern of 100 nm or less is formed. A positive photosensitive composition comprises a compound which generates an acid by the irradiation of an active ray or a radioactive ray; and a resin which comprises a repeating unit represented by the formula I and a repeating unit represented by -L-R3 and whose dissolution velocity in an alkali developer increases by the action of an acid, wherein X_a1 is H, an alkyl group, a cyano group, or a halogen atom; R_y1, R_y2 and R_x are independently an alkyl group, or a cycloalkyl group; Z_a is an alkylene group; L is a C4-C30 divalent connecting group; and R3 is H, a hydroxyl group, or an organic group.

Description

Positive type photosensitive composition and pattern formation method using same {POSITIVE TYPE PHOTOSENSITIVE COMPOSITION AND PATTERN FORMATION METHOD USING THE SAME}

TECHNICAL FIELD The present invention relates to a positive photosensitive composition used in the production of circuit boards such as semiconductors such as ICs, liquid crystals, thermal heads, and the like, and other photo publication processes, and a pattern forming method using the same. More specifically, the present invention relates to a positive photosensitive composition suitable for an exposure light source such as far ultraviolet rays of 250 nm or less, preferably 220 nm or less, an electron beam or the like, and a pattern forming method using the same.

The chemically amplified photosensitive composition generates acid in the exposed portion by irradiation with actinic light or radiation such as far ultraviolet light, and the solubility of the active light or radiation in the developer of the irradiated portion and the non-irradiated portion by reaction using the acid as a catalyst. It is a pattern forming material which changes and forms a pattern on a board | substrate.

When the KrF excimer laser is used as the exposure light source, a resin mainly composed of poly (hydroxystyrene) having a low absorption in the 248 nm region is used as a main component, thereby forming a high sensitivity, high resolution, and a good pattern. It is a good system compared with the naphthoquinone diazide / novolak resin system.

On the other hand, when a better short wavelength light source, such as an ArF excimer laser (193 nm), is used as the exposure light source, the chemical amplification system is not sufficient because the compound having an aromatic group exhibits a large absorption in the 193 nm region. Did.

For this reason, the resist for ArF excimer laser containing resin which has alicyclic hydrocarbon structure has been developed. Various improvements have been made in the ArF excimer laser resist. For example, Patent Document 1, Patent Document 2, Patent Document 3, and the like have repeats having a spacer portion between the main chain and the acid decomposer in an alicyclic acid decomposable repeating unit. Various characteristics are improved by introducing a unit.

However, when forming a fine pattern such as a line width of 100 nm or less, even if the resolution performance is excellent, the performance stability against the problem of pattern collapse or the change in exposure amount, which cause the formed line pattern to collapse and become a defect in device manufacturing (exposure latitude). In the present invention, the composition was still insufficient.

Moreover, in recent years, immersion lithography which applies the technique which improves the resolution in an optical microscope as a method for achieving finer pattern formation 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 and exposed.

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

On the other hand, a thermal flow process is a method of forming a resist pattern by a conventional lithography technique and then heat-treating the resist pattern to refine the pattern size. By heating after the pattern formation, the resist pattern is softened and flows in the gap direction of the pattern, whereby the size (hole diameter of the hole pattern, space width of the line and space pattern, etc.) where the pattern is not formed can be reduced. However, in the resist composition used in conventional ArF excimer laser lithography or the like, since the glass transition temperature of the base resin is high, the softening of the base resin due to the heating temperature in the thermal flow process is insufficient, and thus the miniaturization of the resist pattern by the thermal flow process is difficult. There is a problem that is difficult. In patent document 5 and patent document 6, control of the pattern size by introduction of the low Tg acid-decomposable group into resin is tried. However, such simple low Tg is difficult to be compatible with the resolution.

In view of recent resolution improvement, Patent Literature 7 and Patent Literature 8 have attempted to use a resin having an acid-decomposable group remote from the polymer main chain via various spacer groups. However, the introduction of the spacer group alone was insufficient for low Tg.

Patent Document 1: Japanese Patent Publication No. 2005-331918

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

Patent Document 3: Japanese Unexamined Patent Publication 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: Japanese Patent Application Laid-Open No. 10-303114

Patent Document 5: Japanese Unexamined Patent Publication No. 2007-114412

Patent Document 6: Japanese Patent Application Publication No. 2007-114613

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

Patent Document 8: Japanese Patent Application Laid-Open No. 2005-331918

The present invention has been made in view of the above circumstances, and in the formation of a fine pattern of 100 nm or less, pattern collapse, exposure latitude, and line edge roughness are improved, and a positive type having excellent controllability of a resist pattern in a thermal flow process is provided. It is providing the photosensitive composition and the pattern formation method 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 It has a repeating unit (2) which has a bivalent coupling group of -30, R <_3> represents a hydrogen atom, a hydroxyl group, or an organic group, and contains resin which the dissolution rate with respect to alkaline developing solution increases by the action of an acid. A positive photosensitive composition characterized by the above-mentioned.

In 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 represent an alkyl group or a cycloalkyl group.

Za represents an alkylene group.

(2) Positive type photosensitive composition as described in (1) characterized by repeating unit (2) represented by following General formula (II).

In general formula (II)

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

L represents a C4-C30 bivalent coupling group.

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

(3) The positive photosensitive composition as described in (1) or (2) characterized by the resin of (B) component having two or more types of repeating units (1) represented by general formula (I).

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

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

In general formula (pI)-(pV)

R ₁₁ represents an alkyl group.

Z represents an atomic group necessary for forming a cycloalkyl group in addition to 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. In addition, 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. In addition, R ₂₃ and R ₂₄ may be bonded to each other to form a ring.

(6) The positive photosensitive composition as described in (5) whose acid-decomposable repeating unit (3) is represented by following General formula (III-1).

In general formula (III-1)

R represents a hydrogen atom, a halogen atom or an alkyl group. Some R may be same or different, respectively.

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 of groups of general formulas (pI) to (pV).

(7) The positive photosensitive composition as described in (4) characterized by the repeating unit (3) shown by following General formula (III-2).

In 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 according to any one of (1) to (7), wherein the resin of the component (B) further has a repeating unit (4) represented by the following General Formula (IV).

In 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 divalent linking group, ether group, ester group, carbonyl group or a divalent group combining these having a single bond, an alkylene group, a monocyclic or polycyclic alicyclic hydrocarbon structure.

(9) The positive photosensitive composition according to any one of (1) to (8), wherein the resin of the component (B) further has a repeating unit (5) represented by the following General Formula (V).

In 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) characterized by having at least 1 type or more of repeating units (1)-(5), respectively.

(11) The pattern formation method characterized by including the process of forming a film | membrane by the positive photosensitive composition as described in (1)-(10), and exposing and developing the said film | membrane.

(Effects of the Invention)

According to the present invention, a positive photosensitive composition having excellent controllability of a resist pattern and a pattern using the same are improved in pattern collapse, exposure latitude, and line edge roughness in forming a fine pattern of 100 nm or less. Formation methods can be provided.

EMBODIMENT OF THE INVENTION Hereinafter, the best form for implementing this invention is demonstrated in detail.

In addition, in description of group (atom group) in this specification, the description which is not writing substitution and unsubstitution includes what has a substituent as well as not having a substituent. For example, an "alkyl group" includes not only the alkyl group (unsubstituted alkyl group) which does not have a substituent but the alkyl group (substituted alkyl group) which has a substituent.

(A) a compound which generates an acid by irradiation of actinic light or radiation

The positive photosensitive composition of this invention contains the compound (henceforth an "acid generator") which generate | occur | produces an acid by irradiation of actinic light or a radiation.

As the acid generator, known compounds which generate an acid by irradiation with active light or radiation used in photoinitiators of photocationic polymerization, photoinitiators of photoradical polymerization, photochromic agents of pigments, photochromic agents, or micro resists, and mixtures thereof Can be selected and used appropriately.

For example, a diazonium salt, a phosphonium salt, a sulfonium salt, an iodonium salt, an imide sulfonate, an oxime sulfonate, a diazo disulfone, a disulfone, o-nitrobenzyl sulfonate, etc. are mentioned.

Moreover, the compound which introduce | transduced the group which generate | occur | produces an acid by the irradiation of these actinic light or radiation, or the compound in the main chain or side chain of a polymer, for example US patent 3,849,137, German patent 3,914,407, Japanese patent publication 63-26653, Japanese Patent Laid-Open No. 55-164824, Japanese Patent Laid-Open No. 62-69263, Japanese Patent Laid-Open No. 63-146038, Japanese Patent Laid-Open No. 63-163452, Japanese Patent Laid-Open No. 62-153853, The compound described in Unexamined-Japanese-Patent No. 63-146029 etc. can be used.

In addition, compounds that generate an acid by light described in US Pat. No. 3,779,778, EP 126,712, and the like can also be used.

Preferred compounds among the acid generators include compounds represented by the following general formulas (ZI), (ZII) and (ZIII).

In general formula (ZⅠ)

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

_{Carbon number} of the organic group as R <_201> , R <_202> and R <_203> is 1-30 normally, Preferably it is 1-20.

R ₂₀₁ to R ₂₀₃ medium Two may combine to form a ring structure and may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond, and a carbonyl group in a ring. R ₂₀₁ to R ₂₀₃ An alkylene group (for example, butylene group and pentylene group) is mentioned as group which two bond and form.

Z ⁻ represents a non-nucleophilic 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.

A non-nucleophilic anion is an anion which is remarkably low in the ability to generate a nucleophilic reaction, and is an anion capable of suppressing time-dependent decomposition by intramolecular nucleophilic reactions. This improves the stability over time of the resist.

As a sulfonic acid anion, an aliphatic sulfonic acid anion, aromatic sulfonic acid anion, camphor sulfonic acid anion, etc. are mentioned, for example.

As a carboxylic acid anion, an aliphatic carboxylic acid anion, an aromatic carboxylic acid anion, an aralkyl carboxylic acid anion, etc. are mentioned, for example.

The aliphatic moiety in the aliphatic sulfonic acid anion may be an alkyl group or a cycloalkyl group, preferably an alkyl group having 1 to 30 carbon atoms and a cycloalkyl group having 3 to 30 carbon atoms, for example, a methyl group, an ethyl group, a propyl group, isopropyl group, and n-. Butyl, isobutyl, sec-butyl, pentyl, neopentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadec A real group, a hexadecyl group, a heptadecyl group, an octadecyl group, a nonadecyl group, an eicosyl group, a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, an adamantyl group, a norbornyl group, a boronyl group, etc. are mentioned.

As an aromatic group in an aromatic sulfonic acid anion, Preferably, a C6-C14 aryl group, for example, a phenyl group, a tolyl group, a naphthyl group, etc. are mentioned.

The alkyl group, cycloalkyl group, and aryl group in the aliphatic sulfonic acid anion and aromatic sulfonic acid anion may have a substituent. As a substituent of the alkyl group, cycloalkyl group, and aryl group in aliphatic sulfonic acid anion and aromatic sulfonic acid anion, for example, nitro group, halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), carboxyl group, hydroxyl group, amino group, cyano group , Alkoxy group (preferably 1 to 15 carbon atoms), cycloalkyl group (preferably 3 to 15 carbon atoms), aryl group (preferably 6 to 14 carbon atoms), alkoxycarbonyl group (preferably 2 to 7 carbon atoms), Practical group (preferably 2 to 12 carbon atoms), alkoxycarbonyloxy group (preferably 2 to 7 carbon atoms), alkylthio group (preferably 1 to 15 carbon atoms), alkylsulfonyl group (preferably 1 to 15 carbon atoms) ), Alkyliminosulfonyl group (preferably having 2 to 15 carbon atoms), aryloxysulfonyl group (preferably having 6 to 20 carbon atoms), alkylaryloxysulfonyl group (preferably having 7 to 20 carbon atoms), cycloalkyl Aryloxysulfonyl group (preferably having 10 to 2 carbon atoms) 0), an alkyloxyalkyloxy group (preferably C5-20), a cycloalkylalkyloxyalkyloxy group (preferably C8-20), etc. are mentioned. About the aryl group and ring structure which each group has, an alkyl group (preferably C1-C15) is mentioned as a substituent.

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 groups as in the aromatic sulfonic acid anion.

Aralkyl groups in the aralkyl carboxylic acid anion are preferably aralkyl groups having 6 to 12 carbon atoms, such as benzyl, phenethyl, naphthylmethyl, naphthylethyl and naphthylmethyl.

The alkyl group, cycloalkyl group, aryl group and aralkyl group in the aliphatic carboxylic acid anion, the aromatic carboxylic acid anion and the aralkyl carboxylic acid anion may have a substituent. Substituents of the alkyl group, cycloalkyl group, aryl group and aralkyl group in the aliphatic carboxylic acid anion, the aromatic carboxylic acid anion and the aralkyl carboxylic acid anion are, for example, the same halogen atoms, alkyl groups as in the aromatic sulfonic acid anion, A cycloalkyl group, an alkoxy group, an alkylthio group, etc. are mentioned.

As a sulfonylimide anion, saccharin anion is mentioned, for example.

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, for example, methyl group, ethyl group, propyl group, isopropyl group, n-butyl Group, isobutyl group, sec-butyl group, pentyl group, neopentyl group and the like. Substituents for these alkyl groups include halogen atoms, alkyl groups substituted with halogen atoms, alkoxy groups, alkylthio groups, alkyloxysulfonyl groups, aryloxysulfonyl groups, cycloalkylaryloxysulfonyl groups, and the like. Alkyl groups are preferred.

As other non-nucleophilic anions, phosphorus fluoride, boron fluoride, antimony fluoride, etc. are mentioned, for example.

As the non-nucleophilic anion of Z ⁻ , an aliphatic sulfonic acid anion in which the α position of sulfonic acid is substituted with a fluorine atom, an aromatic sulfonic acid anion substituted with a group having a fluorine atom or a fluorine atom, and a bis (alkylsulfonyl) imide having an alkyl group substituted with a fluorine atom Preferred are tris (alkylsulfonyl) methed anions in which an anion and an alkyl group are substituted with fluorine atoms. As the non-nucleophilic anion, more preferably a perfluoro aliphatic sulfonic anion having 4 to 8 carbon atoms, a benzene sulfonic acid anion having a fluorine atom, and still more preferably a nonafluorobutane sulfonic acid anion, a perfluorooctane sulfonic acid anion, and pentafluoro Benzene sulfonic acid anion and 3,5-bis (trifluoromethyl) benzene sulfonic acid anion.

As an organic group as R <_201> , R <_202> and R <_203> , the corresponding group in compound (ZI-1), (ZI-2), (ZI-3) mentioned later is mentioned, for example.

Moreover, the compound which has two or more structures represented by general formula (ZI) may be sufficient. For example, at least 1 of R <_201> -R <_203> of the compound represented by general formula (ZI) is represented by general formula (ZI) The compound which has a structure couple | bonded with at least one of R <_201> -R <_203> of one compound may be sufficient.

As a more preferable (ZI) component, the compound (ZI-1), (ZI-2), and (ZI-3) demonstrated below are mentioned.

Compound (ZI-1) is an arylsulfonium compound in which at least one of R ₂₀₁ to R ₂₀₃ of General Formula (ZI) is an aryl group, that is, a compound having arylsulfonium as a 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.

As an aryl group of an arylsulfonium compound, a phenyl group and a naphthyl group are preferable, More preferably, it is 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 and the like. Examples of the aryl group having a heterocyclic structure include pyrrole residues (groups formed by the loss of one hydrogen atom from pyrrole), furan residues (groups formed by the loss of one hydrogen atom from furan), and thiophene residues (Groups formed by the loss of one hydrogen atom from thiophene), indole residues (groups formed by the loss of one hydrogen atom from indole), benzofuran residues (groups formed by the loss of one hydrogen atom from benzofuran), benzo And thiophene residues (groups formed by the loss of one hydrogen atom from benzothiophene). When an arylsulfonium compound has two or more aryl groups, two or more aryl groups may be same or different.

The alkyl group or cycloalkyl group which an arylsulfonium compound has as needed has a C1-C15 linear or branched alkyl group, and a C3-C15 cycloalkyl group is preferable, For example, a methyl group, an ethyl group, a propyl group, n-butyl group , sec-butyl group, t-butyl group, cyclopropyl group, cyclobutyl group, cyclohexyl group and the like.

The aryl group, alkyl group and cycloalkyl group of R ₂₀₁ to R ₂₀₃ are an alkyl group (for example, having 1 to 15 carbon atoms), a cycloalkyl group (for example, having 3 to 15 carbon atoms), an aryl group (for example, having 6 to 14 carbon atoms) and alkoxy You may have group (for example, C1-C15), a halogen atom, a hydroxyl group, and a phenylthio group as a substituent. As a preferable substituent, it is a C1-C12 linear or branched alkyl group, a C3-C12 cycloalkyl group, a C1-C12 linear, branched or cyclic alkoxy group, More preferably, it is a C1-C4 alkyl group and C1-C1-C It is an alkoxy group of 4. The substituent may be substituted on any one of three R ₂₀₁ to R ₂₀₃ , or may be substituted on all three. In addition, when R ₂₀₁ to R ₂₀₃ is an aryl group, the substituent is substituted at the p-position of the aryl group. It is desirable to have.

Next, a compound (ZI-2) is demonstrated.

Compound (ZI-2) is a compound in which R ₂₀₁ to R ₂₀₃ in General Formula (ZI) each independently represent an organic group having no aromatic ring. Here, the aromatic ring also includes an aromatic ring containing a hetero atom.

The organic group which does not contain an aromatic ring as R ₂₀₁ to R ₂₀₃ is generally 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms.

R ₂₀₁ to R ₂₀₃ are each independently preferably an alkyl group, a cycloalkyl group, an allyl group, a vinyl group, and more preferably a linear or branched 2-oxoalkyl group, 2-oxocycloalkyl group, alkoxycarbonylmethyl group, and particularly preferably Preferably a straight or branched 2-oxoalkyl group.

As the alkyl group and the cycloalkyl group of R ₂₀₁ to R ₂₀₃ , a linear or branched alkyl group having 1 to 10 carbon atoms (for example, methyl group, ethyl group, propyl group, butyl group and pentyl group) and a cycloalkyl group having 3 to 10 carbon atoms (cyclo Pentyl group, cyclohexyl group, norbornyl group) is mentioned. More preferred examples of the alkyl group include 2-oxoalkyl group and alkoxycarbonylmethyl group. As a cycloalkyl group, More preferably, 2-oxocycloalkyl group is mentioned.

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

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

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

R ₂₀₁ to R ₂₀₃ may be further substituted with a halogen atom, an alkoxy group (for example, carbon number 1 to 5), a hydroxyl group, a cyano group, and a nitro group.

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

In 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.

At least two of R _1c to R _5c , R _6c and R _7c , and R _x and R _y may be bonded to each other to form a ring structure, and the ring structure may be an oxygen atom, a sulfur atom, an ester bond or an amide bond. You may include it. A butylene group, a pentylene group, etc. are mentioned as a group which two or more of R <_1c> -R <_5c> , R <_6c> and R <_7c> , and R <_x> and R <_y> combine and form.

Zc <^-> represents a non-nucleophilic anion and the non-nucleophilic anion similar to Z <^-> in general formula (ZI) is mentioned.

The alkyl group as R _1c to R _7c may be either straight or branched, for example, an alkyl group having 1 to 20 carbon atoms, preferably a straight and branched alkyl group having 1 to 12 carbon atoms (for example, a methyl group, an ethyl group, a straight chain or a branch). A propyl group, a linear or branched butyl group, a linear or branched pentyl group) is mentioned, As a cycloalkyl group, a C3-C8 cycloalkyl group (for example, a cyclopentyl group, a cyclohexyl group) is mentioned, for example.

The alkoxy group as R _1c to R _5c may be any of linear, branched or cyclic, for example, an alkoxy group having 1 to 10 carbon atoms, preferably a linear and branched alkoxy group having 1 to 5 carbon atoms (e.g., a methoxy group, Ethoxy group, a linear or branched propoxy group, a linear or branched butoxy group, a linear or branched pentoxy group, and a C3-C8 cyclic alkoxy group (for example, cyclopentyloxy group, cyclohexyloxy group) are mentioned.

Preferably, any 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, and more preferably the sum of the carbon numbers of R _1c to R _5c is 2 to 15. For this reason, solvent solubility improves and particle generation | occurrence | production is suppressed at the time of storage.

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

Examples of the 2-oxoalkyl group and the 2-oxocycloalkyl group include groups having> C═O at the 2-position of the alkyl group and the cycloalkyl group as R _1c to R _7c .

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

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

In the general formulas (ZII) and (ZIII)

R ₂₀₄ to R ₂₀₇ each independently represent an aryl group, an alkyl group or a cycloalkyl group.

R ₂₀₄ ~ R ₂₀₇ of the aryl group a phenyl group, a naphthyl group are preferred, and 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 and the like. Examples of the aryl group having a heterocyclic structure include pyrrole residues (groups formed by the loss of one hydrogen atom from pyrrole), furan residues (groups formed by the loss of one hydrogen atom from furan), and thiophene residues (from thiophene). Groups formed by the loss of one hydrogen atom), indole residues (groups formed by the loss of one hydrogen atom from indole), benzofuran residues (groups formed by the loss of one hydrogen atom from benzofuran), and benzothiophene residues ( And groups formed by one hydrogen atom disappearing from benzothiophene).

As the alkyl group and the cycloalkyl group in R ₂₀₄ to R ₂₀₇ , preferably a linear or branched alkyl group having 1 to 10 carbon atoms (for example, methyl group, ethyl group, propyl group, butyl group, pentyl group), and cycloalkyl group having 3 to 10 carbon atoms (Cyclopentyl group, cyclohexyl group, norbornyl group) is mentioned.

The aryl group, alkyl group and cycloalkyl group of 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. For example, C6-C15, an alkoxy group (for example, C1-C15), a halogen atom, a hydroxyl group, a phenylthio group, etc. are mentioned.

Z <^-> represents a non-nucleophilic anion and the thing similar to the non-nucleophilic anion of Z <^-> in General formula (ZI) is mentioned.

As an acid generator, the compound represented by the following general formula (ZIV), (ZV), (ZVI) is further mentioned.

In general formulas (ZIV) to (ZVI)

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

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

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

More preferably, it is a compound represented by general formula (ZI)-(ZIII) among acid generators.

Moreover, the compound which produces | generates the acid which has one sulfonic acid group or an imide group as an acid generator is preferable, More preferably, the compound which produces | generates monovalent perfluoro alkanesulfonic acid, or contains a monovalent fluorine atom or a fluorine atom A compound that generates an aromatic sulfonic acid substituted with a group or a compound that generates an imide acid substituted with a monovalent fluorine atom or a group containing a fluorine atom, and more preferably a fluorinated substituted alkanesulfonic acid, a fluorine-substituted benzenesulfonic acid, or fluorine Sulfonium salts of substituted imide acids or fluorine substituted metic acids. The acid generator which can be used is especially preferable that pKa of the acid which generate | occur | produced is fluorine substituted alkanesulfonic acid, fluorinated substituted benzenesulfonic acid, and fluorinated substituted imide acid with pKa = -1 or less, and a sensitivity improves.

Although an especially preferable example is given to the acid generator, this invention is not limited to this.

An acid generator can be used individually by 1 type or in combination of 2 or more types.

As for content in the positive photosensitive composition of an acid generator, 0.1-20 mass% is preferable based on the total solid of a positive photosensitive composition, More preferably, it is 0.5-10 mass%, More preferably, 1-7 mass% to be.

(B) A resin in which the dissolution rate in an alkaline developer increases due to the action of an acid

Resin to a dissolution rate in an alkaline developer increases by the action of an acid to be used in the positive photosensitive composition of the present invention to the general formula which is the repeating unit (1) and -LR ₃ groups (represented by the formula (I), L Represents a divalent linking group having 4 to 30 carbon atoms, and R ₃ has a repeating unit (2) having a hydrogen atom, a hydroxyl group or an organic group).

In 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 represent an alkyl group or a cycloalkyl group.

Za represents an alkylene group.

In General Formula (I), the alkyl group of 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 1 to 8 carbon atoms, more preferably 1 to 4 carbon atoms, and for example, a methyl group, an ethyl group, a propyl group, and an isopropyl group. , Butyl group, isobutyl group, t-butyl group and the like.

The cycloalkyl group of Ry ₁ , Ry ₂ and Rx is preferably a monocyclic cycloalkyl group having 3 to 8 carbon atoms and a polycyclic cycloalkyl group having 7 to 14 carbon atoms. As a preferable monocyclic cycloalkyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclopropyl group, etc. are mentioned, for example. As a preferable polycyclic cycloalkyl group, an adamantyl group, a norbornane group, a tetracyclo dodecanyl group, a tricyclo dodecanyl group, a diamantyl group, etc. are mentioned, for example.

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. By being an alkyl group having 2 or more carbon atoms or a cycloalkyl group, acid decomposability is improved as compared with the methyl group, and sensitivity and post-heating temperature dependence 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. In the alkylene group of Za, part of the methylene group may be substituted with a linking group having a hetero atom such as an oxygen atom, a sulfur atom, an ester group or a ketone group. Za is preferably an alkylene group having 1 to 4 carbon atoms, and particularly preferably -CH _2- , -CH ₂ CH _2- , -CH (CH ₃ )-, or -C (CH ₃ ) _2- . It is preferable that the alkylene group of Za does not have acid leaving property.

Two or more types of repeating unit (1) represented by General formula (I) may be contained in resin of (B) component.

The polymeric compound for forming the repeating unit (1) represented by general formula (I) can be synthesize | combined easily by a well-known method. For example, using the same method as the method of Unexamined-Japanese-Patent No. 2005-331918, after making alcohol and a carboxylic acid halogenide compound react under basic conditions, as shown in following formula. It can synthesize | combine by making this and a carboxylic acid compound react on basic condition.

Although the preferable specific example of the repeating unit (1) represented by General formula (I) is shown below, this invention is not limited to this.

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

As for content of a repeating unit (1), 1-60 mol% is preferable with respect to all the repeating units in a polymer, More preferably, it is 1-50 mol%, More preferably, it is 5-40 mol%.

The resin of the component (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).

The C4-C30 divalent linking group is preferably a linear or branched alkylene group having 4 to 30 carbon atoms, and more preferably a straight or branched alkylene group having 4 to 20 carbon atoms.

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

As a divalent linking group having 4 to 30 carbon atoms of L, for example, (-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), and La represents a single bond or an alkylene group (preferably having 2 to 28 carbon atoms). ), And the like.

In addition, the carbon atom of an ester bond shall not be included in C4-C30 in a C4-C30 bivalent coupling group.

Although the organic group of R <_3> can mention a carboxyl group, a cycloalkyl group, etc., a carboxyl group is especially preferable.

It is preferable that a repeating unit (2) is represented with the following general formula (II).

In general formula (II)

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

L represents a C4-C30 bivalent coupling group.

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.

The C4-C30 divalent linking group is preferably a linear or branched alkylene group having 4 to 30 carbon atoms, and more preferably a straight or branched alkylene group having 4 to 20 carbon atoms.

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

As a divalent linking group having 4 to 30 carbon atoms of L, for example, (-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), and La represents a single bond or an alkylene group (preferably having 2 to 28 carbon atoms). ), And the like.

In addition, the carbon atom of an ester bond shall not be included in C4-C30 in a C4-C30 bivalent coupling group.

Although the organic group of R <_3> can mention a carboxyl group, a cycloalkyl group, etc., a carboxyl group is especially preferable.

Although the specific example of the repeating unit (2) represented by general formula (II) below is shown, this invention is not limited to this.

As for content of a repeating unit (2), 1-40 mol% is preferable with respect to all the repeating units in a polymer, More preferably, it is 1-30 mol%, More preferably, it is 5-20 mol%.

It is preferable that resin of (B) component has acid-decomposable repeating unit (3) different from repeating unit (1).

Although it can use without a restriction | limiting in particular as acid-decomposable repeating unit (3), the repeating unit which has a group which detach | desorbs by the effect | action of the acid represented by the following general formula (pI)-(pV) is preferable.

In general formula (pI)-(pV)

R ₁₁ represents an alkyl group.

Z represents an atomic group necessary for forming a cycloalkyl group in addition to 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. Further, 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.

In General Formula (pII), at least one of R ₁₂ to R ₁₄ is preferably a cycloalkyl group.

In general formula (pIII), it is preferable that at least any one of R <_15> and R <_16> is a cycloalkyl group.

In general formula (pIV), it is preferable that at least 1 of R <_17> -R <_21> is a cycloalkyl group.

In general formula (pV), it is preferable that at least 1 of R <_22> -R <_25> is 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, for example, a methyl group, an ethyl group, an n-propyl group, and isopropyl Group, n-butyl group, isobutyl group, sec-butyl group, etc. are mentioned.

The cycloalkyl group in R ₁₂ to R ₂₅ or the cycloalkyl group formed by Z and a carbon atom may be monocyclic or polycyclic. Specifically, group which has a C5 or more monocyclo, bicyclo, tricyclo, tetracyclo structure, etc. are mentioned. 5-30 are preferable and, as for the carbon number, 6-25 are especially preferable.

Preferred cycloalkyl groups are adamantyl, noradamantyl, decalin residues, tricyclodecanyl, tetracyclododecanyl, norbornyl, cedrol, cyclopentyl, cyclohexyl, cycloheptyl, and cycloocta A methyl group, a cyclodecanyl group, a cyclododecanyl group, etc. are mentioned. More preferably, an adamantyl group, norbornyl group, a cyclohexyl group, a cyclopentyl group, a tetracyclo dodecanyl group, and a tricyclo decanyl group are mentioned.

These alkyl groups and cycloalkyl groups may have new substituents. As a new substituent of an alkyl group and a cycloalkyl group, an alkyl group (preferably C1-C4), a halogen atom, a hydroxyl group, an alkoxy group (preferably C1-C4), a carboxyl group, the alkoxycarbonyl group (preferably C2-C6), etc. Can be mentioned. 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 group represented by general formula (pI)-(pV) can form group (acid-decomposable group) which decomposes by the action of an acid and produces | generates an alkali-soluble group by using it for protection of alkali-soluble group. Examples of the alkali-soluble group include various groups known in the art.

Specific examples include groups in which hydrogen atoms of carboxylic acid groups, sulfonic acid groups, phenol groups and thiol groups are substituted with groups represented by general formulas (pI) to (pV). Hydrogen atom is group substituted by group represented by general formula (pI)-(pV).

As a repeating unit which has the alkali-soluble group protected by the group represented by general formula (pI)-(pV), the repeating unit represented by the following general formula (III-1) is preferable.

In general formula (III-1)

R represents a hydrogen atom, a halogen atom or an alkyl group. Some R may be same or different, respectively.

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 of groups of general formulas (pI) to (pV).

Although the specific example of the repeating unit represented by general formula (III-1) is shown below, this invention is not limited to this.

As an acid decomposable repeating unit (3), the repeating unit represented by the following general formula (III-2) is mentioned.

In 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 the cycloalkyl group of Rya include those similar to the alkyl group and the cycloalkyl group of Ry ₁ , Ry _2, and Rx in the general formula (I).

Z ₁ is the same as Z in General Formula (pI).

As a bivalent coupling group of Zb, a linear or branched alkylene group (preferably C1-C5), a cycloalkylene group (preferably C6-C15), and a combination thereof are mentioned.

Although the specific example of the repeating unit represented by general formula (III-2) is shown below, this invention is not limited to this.

As for content of an acid-decomposable repeating unit (3), 0-60 mol% is preferable with respect to all the repeating units in a polymer, More preferably, it is 1-50 mol%, More preferably, it is 5-40 mol%.

It is preferable that resin of (B) component has a repeating unit which has group which has a lactone structure.

As the group having a lactone structure, any group can be used as long as it has a lactone structure. Preferably, the group has a 5- to 7-membered ring lactone structure, and in the form of forming a bicyclo structure and a spiro structure on the 5- to 7-membered ring lactone structure. It is preferable that the other ring structure is condensed. 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). In addition, the group having a lactone structure may be directly bonded to the main chain. Preferred lactone structures are (LC1-1), (LC1-4), (LC1-5), (LC1-6), (LC1-13), (LC1-14), and the line edge roughness by using a specific lactone structure Varnish and development defects become good.

The lactone structure portion may or may not have a substituent (Rb ₂ ). Preferred substituents (Rb ₂ ) include an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 4 to 7 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkoxycarbonyl group having 1 to 8 carbon atoms, a carboxyl group, a halogen atom, a hydroxyl group, a cyano group, and an acid decomposition. And the like, and more preferably, an alkyl group having 1 to 4 carbon atoms, a cyano group, and an acid decomposable group. n2 represents the integer of 0-4. 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.

As for the repeating unit which has group which has a lactone structure, the repeating unit (4) represented by following General formula (IV) is preferable.

In 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 divalent linking group, ether group, ester group, carbonyl group having a single bond, an alkylene group, a monocyclic or polycyclic alicyclic hydrocarbon structure, or a divalent group combining these.

The alkyl group of R ₆ in General Formula (IV) is preferably an alkyl group having 1 to 4 carbon atoms, and may have a substituent. As a preferable substituent which the alkyl group of R <_6> may have, a hydroxyl group and a halogen atom are mentioned.

Examples of the halogen atom for 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, and preferably a methylene group, an ethylene group, a cyclohexylene group, an adamantylene group and a norbornylene group.

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

The repeating unit having a lactone structure usually has optical isomers, but all optical isomers may be used. Moreover, 1 type of optical isomers may be used independently, or several optical isomers may be mixed and used. When mainly using one optical isomer, it is preferable that the optical purity (ee) is 90 or more, More preferably, it is 95 or more.

Hereinafter, although the specific example of the repeating unit 4 is shown, this invention is not limited to this.

The following repeating unit is mentioned as a especially preferable repeating unit (4). By selecting the most preferable lactone structure, the pattern profile and the density dependence become good.

As for content of the repeating unit (4), 0-60 mol% is preferable with respect to all the repeating units in a polymer, More preferably, it is 1-50 mol%, More preferably, it is 5-40 mol%.

It is preferable that resin of (B) component has a repeating unit (5) represented by the following general formula (V).

In 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 a group which has alicyclic hydrocarbon structure in general formula (V) and R <_9> , an adamantyl group, diamantyl group, and norbornane group are preferable.

As group which has alicyclic hydrocarbon structure substituted by the preferable hydroxyl group or cyano group, group represented by the following general formula (VIIa)-(VIId) is preferable.

In general formula (VIIa)-(VIIc)

R _2C to R _4c each independently represent a hydrogen atom hydroxyl group or a 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 hydroxyl groups, and the rest are hydrogen atoms. In general formula (VIIa), More preferably, two of R <_2C> -R <_4c> are hydroxyl groups, and the remainder is a hydrogen atom.

As for content of the repeating unit (5), 0-40 mo1% is preferable with respect to all the repeating units in a polymer, More preferably, it is 1-30 mo1%, More preferably, it is 5-25 mo1%.

Although the specific example of the repeating unit 5 is given to the following, this invention is not limited to this.

It is preferable that resin of (B) component has one or more types of repeating units (3)-(5), respectively, in addition to a repeating unit (1) and (2).

In addition to the above repeating units, the resin of component (B) may have various repeating units for the purpose of controlling dry etching resistance, standard developer aptitude, substrate adhesion, resist profile, and resolution, heat resistance, sensitivity, etc. which are generally necessary properties of resist. .

Although the repeating unit corresponded to the following monomer as a repeating unit is mentioned, It is not limited to these.

This results in the performance required for the resin of component (B), in particular

(1) solubility in coating solvents,

(2) film forming property (glass transition point),

(3) alkali developability,

(4) membrane reduction (select hydrophilic, alkali soluble groups),

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

(6) dry etching resistance

Fine adjustment of the back and the like becomes possible.

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. Can be mentioned.

In addition, as long as it is an addition polymerizable unsaturated compound copolymerizable with the monomer corresponded to the said various repeating units, it may be copolymerized.

The molar ratio of each repeating unit in the resin of component (B) is suitably used to control dry etching resistance of resist, standard developer aptitude, substrate adhesion, resist profile, and resolution, heat resistance, sensitivity, etc. which are general necessary performances of resist. Is set.

When the positive photosensitive composition of this invention is for ArF exposure, it is preferable that resin of (B) component does not have an aromatic group from the point of transparency to ArF light.

As resin of (B) component, Preferably, all of a repeating unit is comprised by the (meth) acrylate type repeating unit. In this case, all of the repeating units may be either methacrylate-based repeating units, all of the repeating units may be acrylate-based repeating units, or all of the repeating units may be any of a mixture of methacrylate-based repeating units / acrylate-based repeating units. have.

Resin of (B) component can be synthesize | combined according to a conventional method (for example, radical polymerization). For example, as a general synthesis method, the batch polymerization method which superposes | polymerizes by melt | dissolving and heating a monomer and a polymerization initiator in a solvent, and the dropping polymerization method which adds the solution of a monomer and a polymerization initiator dropwise to a heating solvent for 1 to 10 hours, etc. are added. The dropping 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 and dimethyl Amides, such as acetamide, and the solvent which melt | dissolves the positive photosensitive composition of this invention, such as propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, and cyclohexanone mentioned later, are mentioned. More preferably, it is preferable to superpose | polymerize using the same solvent as the solvent used for the positive photosensitive composition of this invention. For this reason, generation | occurrence | production of the particle at the time of storage can be suppressed.

It is preferable that a polymerization reaction is performed in inert gas atmosphere, such as nitrogen and argon. As a polymerization initiator, superposition | polymerization is started using a commercial radical initiator (azo initiator, peroxide, etc.). As a radical initiator, an azo initiator is preferable, and the azo initiator which has an ester group, a cyano group, and a carboxyl group is preferable. Preferred initiators include azobisisobutyronitrile, azobisdimethylvaleronitrile, dimethyl 2,2'-azobis (2-methylpropionate) and the like. If desired, a polymerization initiator is added or added in portions, and after completion of the reaction, it 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% by mass, preferably 10 to 30% by mass. Reaction temperature is 10 degreeC-150 degreeC normally, Preferably it is 30 degreeC-120 degreeC, More preferably, it is 60-100 degreeC.

The weight average molecular weight of the resin of the component (B) is preferably 1,000 to 200,000, more preferably 3,000 to 20,000, particularly preferably 5,000 to 15,000, as a polystyrene conversion value by the 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, and deterioration in developability or viscosity can be prevented from deteriorating film forming property.

Molecular weight distribution is 1-5 normally, Preferably it is 1-3, More preferably, the thing of the range of 1-2 is used. The smaller the molecular weight distribution, the better the resolution and resist shape, the smoother the sidewall of the resist pattern, and the better the roughness.

In the positive photosensitive composition of the present invention, the blending amount in the whole composition of the resin of the component (B) is preferably from 50 to 99.9 mass% in the total solid, more preferably from 60 to 99.9 mass%.

In addition, in this invention, resin of (B) component may be used by 1 type, and may be used together plural.

(C) Dissolution control compound with a molecular weight of 3000 or less having at least one selected from alkali-soluble groups, hydrophilic groups, and acid-decomposable groups

To the positive photosensitive composition of the present invention, a dissolution control compound having a molecular weight of 3000 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.

As the dissolution control compound, a compound having an alkali-soluble group such as a carboxyl group, a sulfonyl imide group, a hydroxyl group in which the α position is substituted with a fluoroalkyl group, a hydroxyl group, a lactone group, a cyano group, an amide group, a pyrrolidone group, a sulfonamide group, etc. Preferred are compounds having a hydrophilic group and compounds having a group which is decomposed by the action of an acid to release an alkali soluble group or a hydrophilic group. As a group which decomposes by the action of an acid to release an alkali-soluble group or a hydrophilic group, a group in which a carboxyl group or a hydroxyl group is protected by a group which is released by the action of an acid is preferable. As a dissolution control compound, in order not to reduce permeability of 220 nm or less, it is preferable to use the compound which does not contain an aromatic ring, or to use the compound which has an aromatic ring in the addition amount of 20 wt% or less with respect to solid content of a composition.

As a preferable dissolution control compound, the carboxylic acid compound which has alicyclic hydrocarbon structure, such as adamantane (di) carboxylic acid, norbornane carboxylic acid, and a cholic acid, the compound which protected this carboxylic acid with an acid-decomposable group, saccharides, etc. The polyol or the compound which protected the hydroxyl group by the acid-decomposable group is preferable.

The molecular weight of a dissolution control compound is 3000 or less, Preferably it is 300-3000, More preferably, it is 500-2500.

The addition amount of a dissolution control compound becomes like this. Preferably it is 3-40 mass% with respect to solid content of a positive photosensitive composition, More preferably, it is 5-20 mass%.

Although the specific example of a dissolution control compound is shown below, this invention is not limited to these.

Basic compound

It is preferable that the positive photosensitive composition of this invention contains a basic compound in order to reduce the performance change by time-lapse from exposure to heating.

As a basic compound, Preferably, the compound which has a structure represented by following formula (A)-(E) is mentioned.

In formulas (A) and (E)

R ²⁰⁰ , R ²⁰¹ and R ²⁰² may be the same as or different from each other, and 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 (with 6 to 20 carbon atoms) In this case, 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 same or different, and represent a C1-C20 alkyl group.

As an alkyl group which has a substituent with respect to the said alkyl group, a C1-C20 aminoalkyl group, a C1-C20 hydroxyalkyl group, or a C1-C20 cyanoalkyl group is preferable.

As for the alkyl group in these general formula (A) and (E), it is more preferable that it is unsubstituted.

Preferred compounds include guanidine, aminopyrrolidine, pyrazole, pyrazoline, piperazine, aminomorpholine, aminoalkylmorpholine, piperidine and the like, and more preferred compounds include imidazole structure, diazabicyclo structure, Compounds 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 / or an ether bond, and the like. Can be mentioned.

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] nona-5-ene and 1,8-diazabi Cyclo [5,4,0] undec-7-ene and the like. Examples of the compound having an onium hydroxide structure include tetrabutylammonium hydroxide, triarylsulfonium hydroxide, phenacylsulfonium hydroxide, and sulfonium hydroxide having a 2-oxoalkyl group, specifically triphenylsulfonium Hydroxide, tris (t-butylphenyl) sulfonium hydroxide, bis (t-butylphenyl) iodine hydroxide, phenacylthiophenium hydroxide, 2-oxopropylthiophenium hydroxide and the like. Can be mentioned. As a compound which has an onium carboxylate structure, the anion part of the compound which has an onium hydroxide structure became a carboxylate, For example, acetate, adamantane-1-carboxylate, a perfluoroalkyl carboxylate, etc. Can be mentioned. 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-dibutylaniline, N, N-dihexylaniline, and the like. Examples of the alkylamine derivative having a hydroxyl group and / or an ether bond include ethanolamine, diethanolamine, triethanolamine, N-phenyl diethanolamine, tris (methoxyethoxyethyl) amine, and the like. As an aniline derivative which has a hydroxyl group and / or an ether bond, N, N-bis (hydroxyethyl) aniline etc. are mentioned.

Preferred basic compounds also include amine compounds having a phenoxy group, ammonium salt compounds having a phenoxy group, amine compounds having a sulfonic acid ester group and ammonium salt compounds having a sulfonic acid ester group.

As the amine compound, primary, secondary and tertiary amine compounds may be used, and an amine compound in which at least one alkyl group is bonded to a nitrogen atom is preferable. As for an amine compound, it is more preferable that it is a tertiary amine compound. If at least one alkyl group (preferably having 1 to 20 carbon atoms) is bonded to a nitrogen atom, the amine compound may have a cycloalkyl group (preferably having 3 to 20 carbon atoms) or an aryl group (preferably having 6 to 12 carbon atoms) in addition to the alkyl group. It may be bonded to a nitrogen atom. It is preferable that an amine compound has an oxygen atom in the alkyl chain, and the oxyalkylene group is formed. The number of oxyalkylene groups is 1 or more in a molecule | numerator, Preferably it is 3-9, More preferably, it is 4-6. Among 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 preferable, and more preferably It is an oxyethylene group.

As the ammonium salt compound, a primary, secondary, tertiary or quaternary ammonium salt compound can be used, and an ammonium salt compound in which at least one alkyl group is bonded to a nitrogen atom is preferable. An ammonium salt compound is a cycloalkyl group (preferably C3-20) or an aryl group (preferably C6-C12) in addition to the alkyl group if at least one alkyl group (preferably C1-C20) is bonded to the nitrogen atom. It may be bonded to an atom. The ammonium salt compound preferably has an oxygen atom in the alkyl chain and an oxyalkylene group is formed. The number of oxyalkylene groups is 1 or more in a molecule | numerator, Preferably it is 3-9, More preferably, it is 4-6. Among 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 preferable, and more preferably It is an oxyethylene group.

Examples of the anion of the ammonium salt compound include a halogen atom, sulfonate, borate, phosphate, and the like. Among them, halogen atoms and sulfonates are preferable. As the halogen atom, chloride, bromide and iodide are particularly preferable, and as sulfonate, organic sulfonate having 1 to 20 carbon atoms is particularly preferable. Examples of the organic sulfonate include alkyl sulfonates having 1 to 20 carbon atoms and arylsulfonates. The alkyl group of the alkylsulfonate may have a substituent, and examples of the substituent include fluorine, chlorine, bromine, alkoxy group, acyl group, and aryl group. Specific examples of the alkylsulfonate include methanesulfonate, ethanesulfonate, butanesulfonate, hexanesulfonate, octanesulfonate, benzylsulfonate, trifluorosulfonate, pentafluorosulfonate, and nonafluorobutanesulfonate. Can be mentioned. Examples of the aryl group of the arylsulfonate include a benzene ring, a naphthalene ring, and an anthracene ring. The benzene ring, naphthalene ring and anthracene ring may have a substituent, and as a substituent, a C1-C6 linear or branched alkyl group and a C3-C6 cycloalkyl group are preferable. 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. As another substituent, a C1-C6 alkoxy group, a halogen atom, cyano, nitro, an acyl group, an acyloxy group, etc. are mentioned.

The amine compound having a phenoxy group and the ammonium salt compound having a phenoxy group are those having a phenoxy group at a terminal opposite 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 phenoxy group substituent 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 acid ester group, an aryl group, an aralkyl group, an acyloxy group and an aryloxy group. Can be. The substitution position of the substituent may be any of 2 to 6 positions. The number of substituents may be either in the range of 1-5.

It is preferred to have at least one oxyalkylene group between the phenoxy group and the nitrogen atom. The number of oxyalkylene groups is 1 or more in a molecule | numerator, Preferably it is 3-9, More preferably, it is 4-6. Among 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 preferable, and more preferably It is an 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 aryl sulfonic acid ester. In the case of the cycloalkyl sulfonic acid ester, the cycloalkyl group is preferably 3 to 20 carbon atoms, and in the case of the aryl sulfonic acid ester, the aryl group is preferably 6 to 12 carbon atoms. The alkyl sulfonic acid ester, cycloalkyl sulfonic acid ester, and aryl sulfonic acid ester may have a substituent, and as a substituent, a halogen atom, a cyano group, a nitro group, a carboxyl group, a carboxylic acid ester group, and a sulfonic acid ester group are preferable.

It is preferred to have at least one oxyalkylene group between the sulfonic acid ester group and the nitrogen atom. The number of oxyalkylene groups is 1 or more in a molecule | numerator, Preferably it is 3-9, More preferably, it is 4-6. Among 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 preferable, and more preferably It is an oxyethylene group.

These basic compounds are used individually or in combination of 2 or more types.

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

The use ratio of the acid generator and the basic compound in the composition is preferably an acid generator / basic compound (molar ratio) = 2.5 to 300. That is, the molar ratio is preferably 2.5 or more from the point of sensitivity and resolution, and 300 or less is preferable from the point of suppressing the decrease in resolution due to the thickening of the resist pattern over time until the post-exposure 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) Fluorine and / or silicon based surfactants

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

The positive photosensitive composition of the present invention contains a fluorine and / or silicon-based surfactant to provide a resist pattern having good sensitivity and resolution when using an exposure light source of 250 nm or less, especially 220 nm or less, and having low adhesion and development defects. It becomes possible.

As a fluorine and / or silicon type surfactant, For example, Unexamined-Japanese-Patent No. 62-36663, Unexamined-Japanese-Patent No. 61-226746, Unexamined-Japanese-Patent No. 61-226745, Japanese Patent Laid-Open No. 62-170950 JP-A-63-34540, JP-A-7-230165, JP-A-8-62834, JP-A-9-54432, JP-A-9-5988 Japanese Patent Application Laid-Open No. 2002-277862, US Patent 5405720, 5360692, 5529881, 5296330, 5436098, 5576143, 5294511, and The surfactant described in the specification of 5824451 is mentioned, The following commercially available surfactant can also be used as it is.

As a commercially available surfactant which can be used, for example, F-top EF301, EF303, (made by Shin-Akita Kasei Co., Ltd.), fluoride FC430, 431 (made by Sumitomo 3M Co., Ltd.), megapack F176, F189, R08 ( Dainippon ink Kagaku Kogyo Co., Ltd., Suffron S-382, SC101, 102, 103, 104, 105, 106 (made by Asahi Glass Co., Ltd.), Troisol S-366 (Troy Chemical Co., Ltd.) Fluorine-based surfactant or silicon-based surfactants such as (i) and the like. In addition, polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) is also used as the silicon-based surfactant.

In addition, as the surfactant, fluorine derived from fluoroaliphatic compounds produced by the telomerization method (also called telomer method) or the oligomerization method (also called oligomer method) in addition to the known ones described above. As the surfactant, a surfactant using a polymer having an aliphatic group can be used. A fluoro aliphatic compound can be synthesize | combined by the method of Unexamined-Japanese-Patent No. 2002-90991.

As the polymer having a fluoroaliphatic group, a copolymer of a monomer having a fluoroaliphatic group with (poly (oxyalkylene)) acrylate and / or (poly (oxyalkylene)) methacrylate is preferable, even if it is distributed irregularly. It may be good and block copolymerized. Moreover, as a poly (oxyalkylene) group, a poly (oxyethylene) group, a poly (oxypropylene) group, a poly (oxybutylene) group, etc. are mentioned, Furthermore, the block of poly (oxyethylene, an oxypropylene, and an oxyethylene is mentioned. Or a unit having an alkylene having a different chain length in the same chain length, such as a linking body) or a poly (block linking body of oxyethylene and oxypropylene). In addition, the copolymer of the monomer which has a fluoro aliphatic group, and (poly (oxyalkylene)) acrylate (or methacrylate) is not only a binary copolymer but the monomer which has another 2 or more types of fluoro aliphatic groups, or another 2 types The ternary or higher copolymer which copolymerized the above (poly (oxyalkylene)) acrylate (or methacrylate) etc. simultaneously may be sufficient.

For example, Megapack F178, F-470, F-473, F-475, F-476, and F-472 (made by Dainippon Ink & Chemical Co., Ltd.) can be mentioned as a commercial surfactant. Further, copolymers of acrylate (or methacrylate) having a C ₆ F ₁₃ group and (poly (oxyalkylene)) acrylate (or methacrylate), acrylate (or methacrylate having a C ₆ F ₁₃ group) ) And a copolymer of (poly (oxyethylene)) acrylate (or methacrylate) and (poly (oxypropylene)) acrylate (or methacrylate), an acrylate (or methacrylate having a C ₈ F ₁₇ group) ) And (poly (oxyalkylene)) acrylates (or methacrylates), acrylates (or methacrylates) and (poly (oxyethylene)) acrylates (or methacrylates) having C ₈ F ₁₇ groups And copolymers of (poly (oxypropylene)) acrylate (or methacrylate).

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

Organic solvents

In the positive photosensitive composition of the present invention, each component is dissolved in a predetermined organic solvent and used.

Examples of the organic solvent that can be used include ethylene dichloride, cyclohexanone, cyclopentanone, 2-heptanone, γ-butyrolactone, methyl ethyl ketone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 2- Methoxyethyl acetate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, toluene, ethyl acetate, methyl lactate, ethyl lactate, methyl methoxypropionate, ethyl ethoxypropionate, methyl pyruvate , Ethyl pyruvate, propyl pyruvate, N, N-dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, 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 solvents having different functional groups. For this reason, the solubility of a raw material improves and the generation | occurrence | production of the particle | grains in time can be suppressed, and the generation | occurrence | production of the defect at the time of application | coating can be suppressed, and a favorable pattern profile is obtained. As a preferable functional group which a solvent has, an ester group, a lactone group, a hydroxyl group, a ketone group, a carbonate group, etc. are mentioned. As a mixed solvent which has another functional group, the mixed solvent of the following (S1)-(S5) is preferable.

(S1) Mixed solvent which mixed the solvent which has a hydroxyl group, and the solvent which does not have a hydroxyl group,

(S2) Mixed solvent which mixed the solvent which has a ester structure, and the solvent which has a ketone structure,

(S3) Mixed solvent which mixed the solvent which has a ester structure, and the solvent which has a lactone structure,

(S4) Mixed solvent which mixed the solvent which has an ester structure, the solvent which has a lactone structure, and the solvent which has a hydroxyl group,

(S5) The mixed solvent which mixed the solvent which has an ester structure, the solvent which has a carbonate structure, and the solvent which has 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, ethyl lactate, and the like. Monomethyl ether and ethyl lactate are particularly preferred.

Examples of the solvent having no hydroxyl group include propylene glycol monomethyl ether acetate, ethyl ethoxy propionate, 2-heptanone, γ-butyrolactone, cyclohexanone, butyl acetate, N-methylpyrrolidone, N, N-dimethylacetamide, dimethyl sulfoxide, etc. are mentioned, Among these, a propylene glycol monomethyl ether acetate, ethyl ethoxy propionate, 2-heptanone, (gamma) -butyrolactone, cyclohexanone, and butyl acetate are preferable. More preferably, propylene glycol monomethyl ether acetate, ethyl ethoxy propionate, 2-heptanone, and cyclohexanone are more preferable.

As a solvent which has a ketone structure, cyclohexanone, 2-heptanone, etc. are mentioned, for example, Preferably, it is cyclohexanone.

Examples of the solvent having an ester structure include propylene glycol monomethyl ether acetate, ethyl ethoxy propionate, butyl acetate, and the like, and preferably propylene glycol monomethyl ether acetate.

As a solvent which has a lactone structure, (gamma) -butyrolactone is mentioned, for example.

As a solvent which has a carbonate structure, propylene carbonate, ethylene carbonate, etc. are mentioned, for example, Preferably it is propylene carbonate.

The mixing ratio (mass) of the solvent having a hydroxyl group and the solvent not having a hydroxyl group is usually 1/99 to 99/1, preferably 10/90 to 90/10, and more preferably 20/80 to 60/40. The mixed solvent which contains 50 mass% or more of solvents which does not have a hydroxyl group is especially preferable at the point of application | coating uniformity.

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

The mixing ratio (mass) of the solvent having an ester structure and the solvent having a lactone structure is usually 70/30 to 99/1, preferably 80/20 to 99/1, and more preferably 90/10 to 99/1. The mixed solvent which contains 70 mass% or more of solvents which have an ester structure is especially preferable at the point of stability with time.

When mixing the solvent which has an ester structure, the solvent which has a lactone structure, and the solvent which has a hydroxyl group, 30-20 mass% of the solvent which has an ester structure, 1-20 mass% of the solvent which has a lactone structure, and the solvent which has a hydroxyl group It is preferable to contain 10-60 mass%.

When mixing the solvent which has an ester structure, the solvent which has a carbonate structure, and the solvent which has a hydroxyl group, 30-20 mass% of the solvent which has an ester structure, the solvent which has 1-20 mass% of the solvent which has a carbonate structure, and a hydroxyl group It is preferable to contain 10-60 mass%.

(Pattern formation method)

In the positive photosensitive composition of the present invention, each component is dissolved in a predetermined organic solvent, preferably the mixed solvent, filtered and then applied on a predetermined support. The filter used for the filter filtration is preferably 0.1 micron or less, more preferably 0.05 micron or less, still more preferably 0.03 micron or less, made of polytetrafluoroethylene, polyethylene, or nylon.

A positive photosensitive composition is apply | coated to arbitrary thicknesses (typically 50-500 nm) by the appropriate application | coating methods, such as a spinner and a coater, on the board | substrate (for example, silicon / silicon dioxide coating | cover) used for manufacture of a precision integrated circuit element. After application, it is dried by spin or baking to form a resist film. Although baking temperature can be set suitably, it is 60-150 degreeC normally, Preferably it is 90-130 degreeC.

Subsequently, it exposes through a mask etc. for pattern formation.

Although exposure amount can be set suitably, it is 1-100mJ / cm <2> normally. After exposure, spin or / or baking is preferably performed, and development and rinsing are performed to obtain a pattern.

At the time of irradiation of actinic light or a radiation, you may perform exposure (liquid immersion exposure) between the photosensitive film | membrane and a lens by filling the liquid (liquid immersion medium) with higher refractive index than air. This can improve resolution. As the liquid immersion medium to be used, any liquid can be used as long as the liquid has a refractive index higher than that of air, but is preferably pure water. In addition, in order to prevent a liquid immersion medium from directly contacting a photosensitive film when performing immersion exposure, you may further form an overcoat layer on the photosensitive film. For this reason, elution of the composition from the photosensitive film | membrane to the immersion medium is suppressed, and a developing defect is reduced.

Examples of the active light or radiation include infrared light, visible light, ultraviolet light, far-ultraviolet light, X-rays, electron beams, and the like, but are preferably ultraviolet light having a wavelength of 250 nm or less, more preferably 220 nm or less, specifically KrF. An excimer laser (248 nm), an ArF excimer laser (193 nm), an F ₂ excimer laser (157 nm), an X-ray, an electron beam, and the like, and an ArF excimer laser, an F ₂ excimer laser, an EUV (13 nm), an electron beam is preferable. Do.

Before forming a photosensitive film, you may apply | coat and form an antireflection film on a board | substrate previously.

As the anti-reflection film, both inorganic film types such as titanium, titanium dioxide, titanium nitride, chromium oxide, carbon, amorphous silicon, and an organic film type made of a light absorber and a polymer material can be used. As the organic antireflection film, commercially available organic antireflection films such as DUV30 series, DUV-40 series manufactured by Brewer Science, and AR-2, AR-3, AR-5, manufactured by Seaplay, can also be used.

In the developing step, an alkaline developer is used. Examples of the alkaline developer include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate and aqueous ammonia, first amines such as ethylamine and n-propylamine, diethylamine and di-n-. Second amines such as butylamine, third amines such as triethylamine and methyldiethylamine, alcohol amines such as dimethylethanolamine and triethanolamine, fourth such as tetramethylammonium hydroxide and tetraethylammonium hydroxide Alkaline aqueous solutions, such as cyclic amines, such as a quaternary ammonium salt, a pyrrole, and piperidine, can be used.

Moreover, alcohol and surfactant can also be added and used for alkali developing solution.

The alkali concentration of alkaline developing solution is 0.1-20 mass% normally.

The pH of alkaline developing solution is 10.0-15.0 normally.

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

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

That is, the resist pattern after the development treatment is softened by heating at least once, preferably 2 to 3 times, and the resist is flowed to form the pattern size of the resist pattern (for example, the hole diameter of the hole pattern and the space width of the line and space). Is reduced (narrowed) than the size immediately after development.

Preferable heating temperature depends on the composition of a positive photosensitive composition, and if it is more than the softening point of a resist pattern, there will be no restriction | limiting in particular, Preferably it is 80-180 degreeC, More preferably, it is in the range of 110-170 degreeC, More preferably, Is 130-170 degreeC. By bringing heating temperature into this range, there exists an advantage that it is easy to suppress a pattern size, and it is easy to use for an existing apparatus.

In addition, a preferable heating time should just be in the range which does not interfere with throughput, and a desired pattern size is obtained, and there is no restriction | limiting in particular, Although it judges from the manufacturing line process of a normal semiconductor element, it is preferable that it is 10-10 for one heating. It is preferable to set it as about 300 second, More preferably, it is about 30 to 180 second.

You may apply the positive photosensitive composition of this invention to the upper resist layer of a multilayer resist process (especially a three-layer resist process). The multilayer resist method includes the following processes.

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

(b) The intermediate layer and the upper resist layer are sequentially laminated on the lower resist layer.

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

As the intermediate layer is typically an organopolysiloxane (silicone resin) or SiO ₂ coating solution (SOG) is used. As the lower layer resist, an appropriate organic polymer film is used, but various known photoresists may be used. For example, each series of the FH series, FHi series, or the PFI series by Sumitomo Kagaku Corporation can be illustrated.

It is preferable that the film thickness of an underlayer resist layer is 0.1-4.0 micrometers, More preferably, it is 0.2-2.0 micrometers, Especially preferably, it is 0.25-1.5 micrometers. It is preferable to set it as 0.1 micrometer or more from a viewpoint of reflection prevention and dry etching resistance, and to set it to 4.0 micrometer or less from a viewpoint of aspect ratio and the pattern collapse of the formed fine pattern.

EXAMPLE

Hereinafter, although an Example demonstrates this invention, this invention is not limited to this.

Synthesis Example 1

43 g of cyclohexanone was put into a three neck flask under nitrogen stream, and this was heated to 80 ° C. To this, 6.8 g of γ-butyrolactone methacrylate, 2.36 g of 3-hydroxyadamantyl-1-methacrylate, 12.8 g of the following monomer (A), 1.88 g of methoxyethoxyethyl methacrylate, and a polymerization initiator V The solution which melt | dissolved 4.5 mol% in 82 g of cyclohexanone with respect to the monomer at -601 (made by Wako Pure Chemical) was dripped over 6 hours. After completion of dropping, this was further reacted at 80 ° C for 2 hours. After cooling the reaction solution, the mixture was added dropwise to a mixed solution of methanol 900m / water over 20 minutes, and the precipitated powder was collected by filtration and dried to obtain 20 g of resin (P-1). The weight average molecular weight of obtained resin (P-1) was 11000, and dispersion degree (Mw / Mn) was 1.65 in standard polystyrene conversion.

Other resin (P-2)-(P-16) was synthesize | combined using the same method. The weight average molecular weight was adjusted by changing the quantity of a polymerization initiator.

Hereinafter, the structure of resin (P-1)-(P-16) is shown.

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

<Resist preparation>

The component shown in following Table 1 was melt | dissolved in the solvent, the solution of 5 mass% of solid content concentration was prepared, This was filtered with the polyethylene filter which has a pore size of 0.03 micrometer, and the positive resist solution was prepared. The prepared positive resist solution was evaluated by the following method, and the result was also shown in Table 1.

Resist Evaluation

An organic antireflection film ARC29A (manufactured by Nissan Kagaku Co., Ltd.) was applied onto the silicon wafer and baked at 205 ° C. for 60 seconds to form an antireflection film having a film thickness of 78 nm. The positive resist composition prepared thereon was apply | coated, and it baked at 110 degreeC for 60 second, and formed the resist film with a film thickness of 160 nm. The obtained wafer was pattern-exposed using the ArF excimer laser scanner (PAS 5500/1100 by NAML, NA 0.75, Annular ((sigma) / (sigma) i = 0.89 / 0.65)). Then, after heating at 110 degreeC for 60 second, it developed for 30 second by the aqueous tetramethylammonium hydrooxide solution (2.38 mass%), rinsed with pure water, and spin-dried to obtain the resist pattern.

Pattern Collapse Assessment Method:

When the exposure amount which reproduces the mask pattern of an 85 nm line and space was made into the optimum exposure amount, when the line width of the line pattern formed by further increasing the exposure amount from the optimal exposure amount was narrowed, it defined as the line width which is resolved without collapsing a pattern. Smaller values indicate that finer patterns are resolved without collapse and that pattern collapse is less likely to occur.

Exposure Latitude Evaluation Method:

The exposure dose which reproduces the mask pattern of 85 nm line and space was made into the optimal exposure dose, and when the exposure dose was changed, the exposure dose width which allows a pattern size of 85 nm +/- 10% was calculated | required, and this value was divided by the optimal exposure dose and displayed as a percentage. . The larger the value, the smaller the change in performance due to the change in exposure amount, and the better the exposure latitude.

Line Edge Roughness Evaluation Method:

The measurement of line edge roughness was observed by using a scanning electron microscope (SEM) to observe an isolated pattern of 120 nm, and the distance from the reference line at which the edge in the longitudinal direction of the line pattern should be edged over a range of 5 μm. 50 points | pieces were measured by length measurement SEM (Hitachi Seisakusho S-9260), the standard deviation was calculated | required, and 3 (sigma) was computed. Smaller values indicate better performance.

Thermal Flow Aptitude Method:

After the pattern of 85 nm line and space was formed, it baked at 150 degreeC, 160 degreeC, and 170 degreeC for 90 second, respectively, and shrinkage of the line width was measured by length measurement SEM (Hitachi Seisakusho S-9260). Of the three measured temperatures, the lowest temperature that shrinks by more than 10% of the original line width is 150 ° C. ◎, 160 ° C ○, and 170 ° C. It was said that x was not lost.

Hereinafter, the symbol in a table | surface is shown.

[Acid generator]

[Basic Compound]

TPSA: Triphenylsulfonium Acetate

DIA: 2,6-diisopropylaniline

TEA: Triethanolamine

DBA: N, N-dibutylaniline

PBI: 2-phenylbenzimidazole

TMEA: tris (methoxyethoxyethyl) amine

PEA: N-phenyldiethanolamine

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

〔Surfactants〕

W-1: Megapack F176 (manufactured by Dainippon Ink & Chemical Co., Ltd.) (Fluorinometer)

W-2: Megapack R08 (manufactured by Dainippon Ink & Chemicals Co., Ltd.) (fluorine and silicon system)

W-3: Polysiloxane Polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) (silicone type)

W-4: Troisol S-366 (made by Troy Chemical Co., Ltd.)

〔solvent〕

S1: Propylene Glycol Methyl Ether Acetate

S4: γ-butyrolactone

S5: Propylene Glycol Methyl Ether

S6: ethyl lactate

It can be seen from Table 1 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)

<Resist preparation>

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

<Resolution evaluation>

An organic antireflection film ARC29A (manufactured by Nissan Kagaku Co., Ltd.) was applied onto the silicon wafer and baked at 205 ° C. for 60 seconds to form an antireflection film having a film thickness of 78 nm. The positive resist solution prepared thereon was apply | coated, and it baked at 110 degreeC and 60 second, and formed the resist film with 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). As the immersion liquid, ultrapure water having an impurity of 5 ppb or less was used. Immediately after exposure, the substrate was heated at 115 ° C. for 90 seconds, developed for 60 seconds with an aqueous tetramethylammonium hydroxide solution (2.38%), rinsed with pure water, and spin dried to obtain a resist pattern obtained by scanning electron microscope (Hitachi S-926.0). ) Was observed, and the 65 nm line and space pattern was resolved.

The positive photosensitive composition of this invention had favorable image forming ability also in the exposure method through the immersion liquid.

Claims (12)

(A) a compound which generates an acid by irradiation of actinic light or radiation; And (B) to that of the repeating unit (1) and -LR ₃ group (formula represented by general formula (Ⅰ), L represents a divalent linkage group having a carbon number of 4 ~ 30, R ₃ represents a hydrogen atom, a hydroxyl group or an organic Positive type photosensitive composition which has a repeating unit (2) which has (), and contains resin which the dissolution rate with respect to alkaline developing solution increases by the action of an acid.

In 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 represent an alkyl group or a cycloalkyl group. Za represents an alkylene group. The positive photosensitive composition as claimed in claim 1, wherein the repeating unit (2) is represented by the following general formula (II).

In general formula (II) X represents a hydrogen atom, an alkyl group, a cyano group or a halogen atom. L represents a C4-C30 bivalent coupling group. R ₃ represents a hydrogen atom, a hydroxyl group or an organic group. The positive photosensitive composition according to claim 1, wherein the resin of the component (B) has two or more types of repeating units (1) represented by the general formula (I). The positive photosensitive composition as claimed in claim 1, wherein the resin of the component (B) further has an acid decomposable repeating unit (3) different from the repeating unit (1). The positive photosensitive composition as claimed in claim 4, wherein the acid decomposable repeating unit (3) has a group which is released by the action of an acid represented by the following general formulas (pI) to (pV).

In general formula (pI)-(pV) R ₁₁ represents an alkyl group. Z represents an atomic group necessary for forming a cycloalkyl group in addition to 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. Further, 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. The positive photosensitive composition as claimed in claim 5, wherein the acid decomposable repeating unit (3) is represented by the following general formula (III-1).

In general formula (III-1) R represents a hydrogen atom, a halogen atom or an alkyl group. Some R may be same or different, respectively. 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 general formulas (pI) to (pV). The positive photosensitive composition as claimed in claim 4, wherein the repeating unit (3) is represented by the following general formula (III-2).

In 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. The positive photosensitive composition according to any one of claims 1 to 7, wherein the resin of the component (B) further has a repeating unit (4) represented by the following general formula (IV).

In 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 divalent linking group, ether group, ester group, carbonyl group having a single bond, an alkylene group, a monocyclic or polycyclic alicyclic hydrocarbon structure, or a divalent group combining these. The positive type photosensitive composition according to claim 1, wherein the resin of the component (B) further has a repeating unit (5) represented by the following general formula (V).

In 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 claim 8, wherein the resin of the component (B) further has a repeating unit (5) represented by the following general formula (V).

In 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 type photosensitive composition of Claim 10 which has 1 or more types of repeating units (1)-(5), respectively. A process of forming a film by the positive photosensitive composition as claimed in claim 1, and exposing and developing the film.