KR101193890B1 - Positive type photosensitive composition and pattern formation method using the same - Google Patents

Abstract

[PROBLEMS] Positive photosensitive compositions used in the production of circuit boards such as semiconductor manufacturing processes such as ICs, liquid crystals, thermal heads, and other photofabrication processes, and pattern forming methods using the same, which form fine patterns of 100 nm or less. The present invention also provides a positive photosensitive composition having improved pattern collapse and exposure latitude performance, and a pattern forming method using the same.

As a positive photosensitive composition containing (A) a compound which generates an acid by irradiation of actinic light or radiation, and a resin whose dissolution rate in an alkali developer is increased by the action of (B) acid, the above-mentioned ( B) A component is a positive photosensitive composition which has a repeating unit represented by a specific structure and has an acid-decomposable group, and the pattern formation method using the same.

Positive photosensitive composition, pattern formation method

Description

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

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to positive type photosensitive compositions used in semiconductor manufacturing processes such as ICs, production of circuit boards such as liquid crystals, thermal heads, and other photofabrication processes, and pattern forming methods using the same. . More specifically, the present invention relates to a positive photosensitive composition and a pattern formation method using the same in the case of using 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.

The chemically amplified photosensitive composition generates an acid in the exposed portion by irradiation with radiation such as far ultraviolet light, and changes the solubility in the developing solution of the irradiated portion and the non-irradiated portion of the active radiation by reaction using the acid as a catalyst. It is a pattern formation material formed on a board | substrate.

In the case of using the KrF excimer laser as an exposure light source, mainly a resin having a low absorption in the 248 nm region and having a poly (hydroxystyrene) as a basic skeleton is used as a main component, thereby forming a high sensitivity, a 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 shorter wavelength light source, such as an ArF excimer laser (193 nm), is used as the exposure light source, the compound having an aromatic group shows a large absorption in the 193 nm region essentially, and thus it is not sufficient even in the chemical amplification system. .

For this reason, the resist for ArF excimer laser containing resin which has alicyclic hydrocarbon structure is developed. In the ArF excimer laser resist, various improvements have been made. For example, in Patent Document 1, Patent Document 2, and Patent Document 3, in the repeating unit having an alicyclic acid-decomposable group, a space portion between the main chain and the acid-decomposable group is used. Various characteristics are improved which introduce | transduce the repeating unit which has a.

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

[Patent Document 1] Japanese Patent Application Laid-Open No. 2005-331918

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

[Patent Document 3] Japanese Patent Publication No. 2003-330192

Accordingly, an object of the present invention is to provide a positive photosensitive composition having improved pattern collapse and exposure latitude performance even when forming a fine pattern of 100 nm or less, and a pattern forming method using the same.

The present invention is as follows.

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

As a positive photosensitive composition containing resin which the dissolution rate with respect to alkaline developing solution increases by the action of (B) acid,

Said (B) component is represented by the following general formula (I), and has a repeating unit which has an acid-decomposable group, The 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 and Ry ₂ each independently represent an alkyl group or a cycloalkyl group.

Rx represents an alkyl group having 2 or more carbon atoms or a cycloalkyl group.

Z represents an alkylene group.

(2) The positive photosensitive composition as described in (1) in which (B) component further has a repeating unit which has 1 or more types of groups chosen from lactone group, a hydroxyl group, a cyano group, and an alkali-soluble group.

(3) The positive photosensitive composition as described in the item (1), wherein the component (B) further has a repeating unit having a hydroxystyrene structure.

(4) Positive of any one of (1)-(3) characterized by (B) component further having a repeating unit represented by general formula (I) and having an acid-decomposable group other than the repeating unit which has an acid-decomposable group. Type photosensitive composition.

(5) Resin which has a repeating unit represented by following General formula (I), and a repeating unit which has at least 1 type or more group chosen from lactone group, a hydroxyl group, a cyano group, and alkali-soluble group.

In general formula (I),

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

Ry ₁ and Ry ₂ each independently represent an alkyl group or a cycloalkyl group.

Rx represents an alkyl group having 2 or more carbon atoms or a cycloalkyl group.

Z represents an alkylene group.

(6) Resin characterized by having a repeating unit represented by the following general formula (I-a).

In general formula (I-a),

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

Ry ₁ and Ry ₂ each independently represent an alkyl group or a cycloalkyl group.

Ry ₃ represents a hydrogen atom or an alkyl group.

Z represents an alkylene group.

m1 represents 1 or 2.

(7) The resin according to (5) or (6), wherein at least one of Ry ₁ and Ry ₂ is an alkyl group having 2 or more carbon atoms.

(8) A polymeric compound characterized by the following general formula (I ').

In general formula (I '),

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

Ry ₁ and Ry ₂ each independently represent an alkyl group or a cycloalkyl group.

Rx represents an alkyl group having 2 or more carbon atoms or a cycloalkyl group.

Z represents an alkylene group.

(9) A polymeric compound characterized by the following general formula (I-a1).

In general formula (I-a1),

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

Ry ₁ and Ry ₂ each independently represent an alkyl group or a cycloalkyl group.

Ry ₃ represents a hydrogen atom or an alkyl group.

Z represents an alkylene group.

m1 represents 1 or 2.

(10) The polymerizable compound according to (8) or (9), wherein at least one of Ry ₁ and Ry ₂ is an alkyl group having 2 or more carbon atoms.

(11) The pattern formation method characterized by including the process of forming a film by the positive photosensitive composition in any one of (1)-(4), and exposing and developing the said film.

According to the present invention, it is possible to provide a positive photosensitive composition having improved pattern collapse and exposure latitude performance even in the formation of a fine pattern of 100 nm or less, and a pattern forming method using the same.

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

In addition, in description of group (atom group) in this specification, the description which is not describing 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 a radiation

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

Such acid generators include known compounds that generate acids by irradiation with actinic rays or radiation used in photoinitiators of photocationic polymerization, photoinitiators of photoradical polymerization, photochromic agents of pigments, photochromic agents or microresists, and the like. Mixtures may be selected as appropriate.

For example, diazonium salt, phosphonium salt, sulfonium salt, iodonium salt, imidosulfonate, oxime sulfonate, diazo disulfone, disulfone, o-nitrobenzyl sulfonate can be mentioned.

Moreover, the compound which introduce | transduced the group which generate | occur | produces an acid by these actinic rays or radiation, or a compound in the main chain or side chain of a polymer, for example, US Patent No. 3,849,137, German Patent No. 3914407, Japanese Patent Publication The compounds described in 63-26653, SO 55-164824, SO 62-69263, SO 63-146038, SO 63-163452, SO 62-153853, SO 63-146029, and the like can be used.

In addition, a compound which generates an acid by light described in US Pat.

As a preferable compound among the compound which generate | occur | produces an acid by irradiation of actinic light or a radiation, the compound represented by the following general formula (ZI), (ZII), (ZIII) can be mentioned.

In general formula (ZI),

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

X ⁻ represents a non-nucleophilic anion, preferably sulfonic acid anion, carboxylic acid anion, bis (alkylsulfonyl) amide anion, tris (alkylsulfonyl) methed anion, BF ₄ ⁻ , PF ₆ ⁻ , SbF ₆ ⁻ And the like, and are preferably organic anions containing carbon atoms.

As a preferable organic anion, the organic anion shown by following General formula (AN1)-(AN4) is mentioned.

In general formula (AN1)-(AN2),

Rc ₁ represents an organic group.

Examples of the organic group in Rc ₁ include those having 1 to 30 carbon atoms, and preferably an alkyl group, an aryl group, or a plurality of them, which may be substituted, are a single bond, -O-, -CO _2- , -S-,- And groups linked with a linker such as SO _3- , -SO ₂ N (Rd ₁ )-. Rd ₁ may represent a hydrogen atom or an alkyl group, and may form a ring structure with the alkyl group and aryl group bonded thereto.

As the organic group of Rc _1, is the more preferably one position is substituted with alkyl groups with a fluorine atom or a flow of an alkyl group, a fluorine atom or an alkyl group substituted with a phenyl flow. By having a fluorine atom or a fluoroalkyl group, the acidity of the acid generated by light irradiation is increased and the sensitivity is improved. In the case of having 5 or more carbon atoms in Rc ₁ , at least one carbon atom preferably contains all hydrogen atoms without being substituted with fluorine atoms, and more preferably has more hydrogen atoms than fluorine atoms. By not having a perfluoroalkyl group having 5 or more carbon atoms, ecological toxicity is reduced.

As a particularly preferable form of Rc ₁ , groups represented by the following general formulas can be listed.

In the above general formula,

Rc ₆ is substituted with up to 4 carbon atoms, more preferably 2 to 4, more preferably 2 to 3 perfluoroalkylene groups, 3 to 5 fluorine atoms and / or 1 to 3 floroalkyl groups A phenylene group is shown.

Ax represents a linking group (preferably single bond, -O-, -CO _2- , -S-, -SO _3- , -SO ₂ N (Rd ₁ )-). Rd ₁ may represent a hydrogen atom or an alkyl group, and may combine with Rc ₇ to form a ring structure.

Rc ₇ represents a hydrogen atom, a fluorine atom, a linear or branched alkyl group, a monocyclic or polycyclic cycloalkyl group or an aryl group. Although the alkyl group, cycloalkyl group, and aryl group may be substituted, it is preferable not to have a fluorine atom as a substituent.

In the general formulas (AN3) to (AN4),

Rc ₃ , Rc ₄ and Rc ₅ each independently represent an organic group.

Preferably as Rc _3, Rc ₄ and Rc ₅ of the organic can be exemplified the same preferred organic groups in Rc _1.

Rc ₃ and Rc ₄ may be bonded to each other to form a ring. Examples of the group formed by bonding of Rc ₃ and Rc ₄ include an alkylene group and an arylene group. Preferably it is a C2-C4 perfluoroalkylene group. By combining Rc ₃ and Rc ₄ to form a ring, the acidity of the acid generated by light irradiation increases and the sensitivity is improved, which is preferable.

In the general formula (ZI),

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

In addition, two of R ₂₀₁ to R _{203 may be} bonded to each other to form a ring structure, and the ring may include an oxygen atom, a sulfur atom, an ester bond, an amide bond, and a carbonyl group. Examples of the group formed by bonding of two of R ₂₀₁ to R ₂₀₃ include an alkylene group (for example, butylene group and pentylene group).

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

In addition, the compound which has two or more structures represented by general formula (ZI) may be sufficient. For example, it may be a compound having the general formula (ZI) of the compound of R ₂₀₁ ~ R, at least one of the ₂₀₃ structure in conjunction with the general formula (ZI) at least one of R ₂₀₁ ~ R ₂₀₃ of a compound represented by represented by the following.

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

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

Arylsulfonium compound is R ₂₀₁ ~ R ₂₀₃ all may be an aryl group, R is an aryl group, a part of R ₂₀₁ ~ _203, the rest may be an alkyl group, a cycloalkyl group.

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, heteroaryl groups, such as an aryl group, such as a phenyl group and a naphthyl group, an indole residue, and a pyrrole residue, are preferable, More preferably, they are a phenyl group and an indole residue. When an arylsulfonium compound has two or more aryl groups, two or more aryl groups may be same or different.

The alkyl group possessed by the arylsulfonium compound as necessary is preferably a linear or branched alkyl group having 1 to 15 carbon atoms, for example, a methyl group, an ethyl group, a propyl group, an n-butyl group, a sec-butyl group, a t-butyl group And the like.

The cycloalkyl group which an arylsulfonium compound has as needed has a C3-C15 cycloalkyl group, For example, a cyclopropyl group, a cyclobutyl group, a cyclohexyl group, etc. can be mentioned.

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), and an aryl group (for example, having 6 to 14 carbon atoms). Branch), an alkoxy group (for example, 1 to 15 carbon atoms), a halogen atom, a hydroxyl group, and a phenylthio group may be used as a substituent. Preferable substituents are a C1-C12 linear or branched alkyl group, a C3-C12 cycloalkyl group, a C1-C12 linear, branched or cyclic alkoxy group, Especially preferably, it is a C1-C4 alkyl group and C1-C1 ˜4 alkoxy groups. As the substituent, any one of three R ₂₀₁ to R ₂₀₃ may be substituted with one, or may be substituted with all three. In the case where R ₂₀₁ to R ₂₀₃ are an aryl group, the substituent is preferably substituted at the p-position of the aryl group.

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

Compound (ZI-2) is a compound in the case where R ₂₀₁ to R ₂₀₃ each independently represent an organic group containing no aromatic ring in formula (ZI). The aromatic ring herein includes an aromatic group 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, more preferably a straight chain, branched, cyclic 2-oxoalkyl group, alkoxycarbonylmethyl group, and particularly preferably straight chain or branched. 2-oxoalkyl group.

The alkyl group as R ₂₀₁ to R ₂₀₃ is preferably a linear or branched alkyl group having 1 to 10 carbon atoms (eg, methyl group, ethyl group, propyl group, butyl group, pentyl group). As for the alkyl group as R <_201> -R <_203> , it is more preferable that they are a linear, branched 2-oxoalkyl group, and the alkoxy methyl group.

The cycloalkyl group as R ₂₀₁ to R ₂₀₃ is preferably a C3-C10 cycloalkyl group (cyclopentyl group, cyclohexyl group, norbornyl group). It is more preferable that the cycloalkyl group as R ₂₀₁ to R ₂₀₃ is a cyclic 2-oxoalkyl group.

The linear, branched, cyclic 2-oxoalkyl group as R ₂₀₁ to R ₂₀₃ is preferably enumerated with a group having> C═O at the 2-position of the alkyl group and cycloalkyl group.

As an alkoxy group in the alkoxycarbonylmethyl group as R <_201> -R <_203> , Preferably, the C1-C5 alkoxy group (methoxy group, an ethoxy group, a propoxy group, butoxy group, pentoxy group) can be mentioned.

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

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 the general formula (ZI-3)

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

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

Rx and Ry each independently represent an alkyl group, a cycloalkyl group, an allyl group or a vinyl group.

At least two of R _1c to R _7c , and Rx and Ry may be bonded to each other to form a ring structure, and the ring structure may include an oxygen atom, a sulfur atom, an ester bond, and an amide bond. _Examples of the group formed by combining two or more of R _1c to R _7c and Rx and Ry to form a butylene group, a pentylene group, and the like.

X <^-> represents a non-nucleophilic anion and can mention the same thing as the non-nucleophilic anion of X <^-> in general formula (I).

The alkyl group as R _1c to R _7c is, for example, a straight or branched alkyl group having 1 to 20 carbon atoms, preferably a straight or branched alkyl group having 1 to 12 carbon atoms (for example, a methyl group, an ethyl group, a straight chain or a branched profile). Groups, straight or branched butyl groups, straight chain or branched pentyl groups).

The cycloalkyl group as R _1c to R _7c is preferably a C3-C8 cycloalkyl group (eg, cyclopentyl group, cyclohexyl group).

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 or branched alkoxy group having 1 to 5 carbon atoms (for example, a methoxy group). , Ethoxy group, straight or branched propoxy group, straight or branched butoxy group, straight or branched pentoxy group, C3-8 cyclic alkoxy group (for example, cyclopentyloxy group, cyclohexyloxy group) Can be.

Preferably, any of R _1c to R _5c is a linear or branched alkyl group, a cycloalkyl group or a linear, branched or cyclic alkoxy group, and more preferably, the sum of the carbon numbers of R _1c to R _5c is 2 to 15. Thereby, solvent solubility improves more and generation | occurrence | production of particle | grains is suppressed at the time of storage.

Alkyl groups as Rx and Ry may be the same as the alkyl groups as R _1c to R _7c . The alkyl group as Rx and Ry is more preferably a straight chain or branched 2-oxoalkyl group or an alkoxymethyl group.

Cycloalkyl groups as Rx and Ry may be the same as the cycloalkyl groups as R _1c to R _7c . It is more preferable that the cycloalkyl group as Rx and Ry is a cyclic 2-oxoalkyl group.

The linear or branched alkyl group and the cyclic 2-oxoalkyl group can enumerate the group which has> C = O in the 2-position of the alkyl group as R < _1c -R < _7c >, and a cycloalkyl group.

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

Rx and Ry are preferably alkyl groups having 4 or more carbon atoms, more preferably 6 or more, still more preferably 8 or more alkyl groups.

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.

Alkyl groups as R ₂₀₄ to R ₂₀₇ are preferably a linear or branched alkyl group having 1 to 10 carbon atoms (eg, methyl group, ethyl group, propyl group, butyl group, pentyl group).

The cycloalkyl group as R ₂₀₄ to R ₂₀₇ is preferably a C3-C10 cycloalkyl group (cyclopentyl group, cyclohexyl group, norbornyl group).

R ₂₀₄ to R ₂₀₇ may have a substituent. R ₂₀₄ ~ R as ₂₀₇ which may have substituents, for example alkyl groups (e.g. having from 1 to 15), a cycloalkyl group (e.g. having 3 to 15), an aryl group (for example, a carbon number of 6 to 15 g. Branch), an alkoxy group (for example, 1 to 15 carbon atoms), a halogen atom, a hydroxyl group, a phenylthio group, and the like.

X <^-> represents a non-nucleophilic anion and can mention the same thing as the non-nucleophilic anion of X <^-> in general formula (I).

As a preferable compound among the compound which decomposes | dissolves by irradiation of actinic light or a radiation, and produces an acid, the compound represented by the following general formula (ZIV), (ZV), (ZVI) can be enumerated further.

In general formula (ZIV)-(ZVI),

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

R ₂₀₈ represents an alkyl group, a cycloalkyl group or an aryl group.

R ₂₀₉ and R ₂₁₀ each independently represent an alkyl group, a cycloalkyl group, an aryl group or an electron withdrawing group. R ₂₀₉ is preferably an aryl group. R ₂₁₀ is preferably an electron withdrawing group, more preferably a cyano group and a fluoroalkyl group.

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

Among the compounds which generate an acid by irradiation of actinic light or radiation, more preferably, they are compounds represented by general formulas (ZI) to (ZIII), still more preferably compounds represented by general formula (ZI), and particularly preferred. Preferably it is a compound represented by general formula (ZI-1)-(ZI-3).

Moreover, the compound which generate | occur | produces the acid represented by the following general formula (AC1)-(AC3) by irradiation of actinic light or a radiation is preferable.

In the formula (AC1) ~ (AC3), Rc 1, Rc 3 ~ Rc 5 is the same meaning as Rc _1, Rc ₃ ~ Rc ₅ in the formula (AN1) ~ (AN4).

As an especially preferable form of an acid generator, in the structure of general formula (ZI), X <^-> is a compound which is an anion selected from said (AN1), (AN3), (AN4).

Among the compounds which generate an acid by irradiation with actinic light or radiation, examples of particularly preferred are listed below.

An acid generator can be used individually by 1 type or in combination of 2 or more type. When using in combination of 2 or more types, it is preferable to combine the compound which produces the 2 types of organic acids from which two or more whole atomic numbers except a hydrogen atom generate | occur | produce.

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

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

Resin (also called "(B) component") which the dissolution rate with respect to alkaline developing solution increases by the action of the acid used for the positive photosensitive composition of this invention is represented with the following general formula (I), and has an acid-decomposable group It has a repeating unit.

In general formula (I),

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

Ry ₁ And Ry ₂ each independently represent an alkyl group or a cycloalkyl group.

Rx represents an alkyl group having 2 or more carbon atoms or a cycloalkyl group.

Z represents an alkylene group.

The -C (= O) -OC (Ry ₁ ) (Ry ₂ ) (Rx) group in the general formula (I) decomposes by the action of an acid to form a carboxyl group, and decomposes by the action of an acid to give an alkaline developer. It is a group (also called an "acid-decomposable group") which the dissolution rate with respect to increases.

Alkyl group of Xa ₁ in the formula (I) is a straight chain alkyl group having from 1 to 4 carbon atoms may be preferred and, for enumerated a methyl group, an ethyl group, etc., for example. The alkyl group of Xa ₁ may be substituted with a hydroxyl group, a halogen atom, or the like. Xa ₁ is preferably a hydrogen atom or a methyl group.

The alkyl group of Ry ₁ and Ry ₂ is preferably a linear or branched alkyl group having 1 to 8 carbon atoms, more preferably 1 to 4 carbon atoms, for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, and a butyl group. , Isobutyl group, t-butyl group, etc. can be mentioned, Preferably they are a methyl group and an ethyl group.

The alkyl group of 2 or more carbon atoms of Rx is preferably 2 to 12 carbon atoms, more preferably 2 to 6 carbon atoms, still more preferably 3 to 6 linear or branched alkyl groups, and an ethyl group, isopropyl group, t- Butyl groups are preferred.

Examples of the cycloalkyl group for Ry ₁ , Ry _2, and Rx include a C3-8 monocyclic cycloalkyl group and a C7-14 polycyclic cycloalkyl group. Preferred monocyclic cycloalkyl groups include cyclopentyl groups, cyclohexyl groups, cyclopropyl groups and the like. Preferred polycyclic cycloalkyl groups include adamantyl, norbornane, tetracyclododecanyl, tricyclodecanyl, diamantyl and the like.

When Rx is a C2 or more alkyl group or a cycloalkyl group, acid-decomposability improves compared with a methyl group, and sensitivity and post-heating temperature dependence after exposure improve.

The alkylene group of Z is preferably an alkylene group having 1 to 8 carbon atoms. You may have a coupling group which has hetero atoms, such as an oxygen atom, a sulfur atom, an ester group, a ketone group, in an alkylene chain. Preferably the number of carbon atoms and from 1 to 4 alkylene group, particularly preferably _{-CH 2 -, -CH 2 CH 2} -, -CH (CH 3) -, -C (CH 3) 2 - a. It is preferable that the alkylene group of Z does not have acid leaving property.

The polymeric compound for forming the repeating unit represented by General formula (I) can be synthesize | combined easily by a well-known method. For example, using the same method as the method described in JP 2005-331918 A, and as shown in the following formula, after reacting an alcohol, a carboxylic acid, and a halogenide compound under basic conditions, this is carried out with carbon. It can synthesize | combine by making an acidic compound react under basic conditions.

Although the preferable specific example of the repeating unit represented by general formula (I) is shown below, this invention is not limited to this. In the specific examples, Xa ₁ represents a hydrogen atom, an alkyl group, a cyano group or a halogen atom.

It is preferable that (B) component has a repeating unit represented by general formula (I) and has an acid-decomposable group other than the repeating unit which has an acid-decomposable group.

Examples of the acid-decomposable group include groups protected by a group in which hydrogen atoms of alkali-soluble groups such as carboxyl groups, phenolic hydroxyl groups, sulfonic acid groups and thiol groups are released by the action of an acid.

Examples of the group leaving by the action of an acid include -C (R ₃₆ ) (R ₃₇ ) (R ₃₈ ), -C (R ₃₆ ) (R ₃₇ ) (OR ₃₉ ), -C (R ₀₁ ) (R ₀₂ ) (OR ₃₉ ), and the like.

In the formula, each of R ₃₆ to R ₃₉ independently represents an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group or an alkenyl group. R ₃₆ and R ₃₇ may be bonded to each other to form a ring.

R ₀₁ to R ₀₂ each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group or an alkenyl group.

As a repeating unit which has an acid-decomposable group other than the repeating unit which has an acid-decomposable group represented by general formula (I), it is preferable that it is a repeating unit represented by the following general formula (II).

In general formula (II),

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

Rx ₁ to Rx ₃ each independently represent an alkyl group or a cycloalkyl group. At least two of Rx ₁ to Rx ₃ may be bonded to form a cycloalkyl group.

Xa ₁ in the formula (II) are the same and Xa ₁ in the formula (I).

The alkyl group of Rx ₁ to Rx ₃ is preferably a linear or branched alkyl group having 1 to 4 carbon atoms, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, t- Butyl group etc. can be mentioned.

Examples of the cycloalkyl group of Rx ₁ to Rx ₃ include monocyclic or polycyclic cycloalkyl groups, and monocyclic cycloalkyl groups such as cyclopentyl group and cyclohexyl group, norbornyl group, tetracyclodecanyl group, tetracyclododecanyl group, Polycyclic cycloalkyl groups, such as an adamantyl group, are preferable.

Examples of the cycloalkyl group formed by bonding at least two of Rx ₁ to Rx ₃ to each other include a monocyclic cycloalkyl group such as a cyclopentyl group and a cyclohexyl group, norbornyl group, tetracyclodecanyl group, tetracyclododecanyl group, and adamantyl group. The polycyclic cycloalkyl group of is preferable.

It is preferable that Rx ₁ is a methyl group or an ethyl group, and Rx ₂ and Rx ₃ are bonded to each other to bond a monocyclic or polycyclic cycloalkyl group.

Although the specific example of the repeating unit which has a preferable acid-decomposable group other than the repeating unit which has an acid-decomposable group represented by general formula (I) is shown below, this invention is not limited to this.

(Wherein Rx is H, CH ₃ , CF ₃ , CH ₂ OH, Rxa, Rxb are each an alkyl group having 1 to 4 carbon atoms)

The repeating unit represented by the general formula (II) is a repeating unit of 1, 2, 10, 11, 12, 13, 14 in the above specific examples.

When using together the repeating unit which has an acid-decomposable group represented by general formula (I), and the repeating unit which has another acid-decomposable group (preferably the repeating unit represented by general formula (II)), it is represented by general formula (I). The ratio of the repeating unit having an acid-decomposable group to be, and the repeating unit having another acid-decomposable group is 90:10 to 10:90, more preferably 80:20 to 20:80 in molar ratio.

As for content of the repeating unit which has all the acid-decomposable groups in (B) component, 20-50 mol% is preferable with respect to all the repeating units in a polymer, More preferably, it is 25-45 mol%.

(B) It is preferable that a component further has a repeating unit which has at least 1 sort (s) of group chosen from lactone group, a hydroxyl group, a cyano group, and alkali-soluble group.

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

As the lactone structure, any one can be used as long as it has a lactone structure. Preferably, the lactone structure is a 5- to 7-membered ring lactone structure, and the other ring structure is condensed in the form of forming a bicyclo structure and a spiro structure to the 5- to 7-membered ring lactone structure. It is preferable. It is more preferable to have a repeating unit having a lactone structure represented by any one of the following general formulas (LC1-1) to (LC1-16). The 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. Genitals and the like. More preferably, they are a C1-C4 alkyl group, cyano group, and an acid-decomposable group. n ₂ represents an integer of 0-4. In the case where n ₂ is 2 or more, a plurality of Rb _{2 's} may be the same or different, and a plurality of Rb _{2' s} may be bonded to each other to form a ring.

As a repeating unit which has a lactone structure represented by any of general formula (LC1-1)-(LC1-16), the repeating unit represented by the following general formula (AI) can be enumerated.

In general formula (AI),

Rb ₀ represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 4 carbon atoms. An alkyl group of Rb ₀ may have good as the preferred substituents are exemplified hydroxyl group, a halogen atom. Examples of the halogen atom for Rb ₀ include fluorine, chlorine, bromine and iodine atoms. Rb ₀ is preferably a hydrogen atom or a methyl group.

Ab represents a bivalent linking group, ether group, ester group, carbonyl group or a divalent linking group having a single bond, an alkylene group, a monocyclic or polycyclic alicyclic hydrocarbon structure. It is preferably a divalent linking group represented by a single bond, -Ab ₁ -CO _2- . Ab ₁ is a linear, branched alkylene group, monocyclic or polycyclic cycloalkylene group, and preferably methylene group, ethylene group, cyclohexylene group, adamantylene group, norbornylene group.

V represents a group having a structure represented by any one of formulas (LC1-1) to (LC1-16).

The repeating unit having a lactone structure usually has an optical isomer, but any optical isomer may be used. In addition, one type of optical isomer may be used alone, or a plurality of optical isomers may be mixed and used. When mainly using one type of optical isomer, it is preferable that the optical purity (ee) is 90 or more, More preferably, it is 95 or more.

As for content of the repeating unit which has a lactone structure, 15-60 mol% is preferable with respect to all the repeating units in a polymer, More preferably, it is 20-50 mol%, More preferably, it is 30-50 mol%.

Although the specific example of the repeating unit which has a lactone structure is listed below, this invention is not limited to these.

Wherein Rx is H, CH ₃ , CH ₂ OH or CF ₃

Wherein Rx is H, CH ₃ , CH ₂ OH or CF ₃

Wherein Rx is H, CH ₃ , CH ₂ OH or CF ₃

The following repeating unit is mentioned as a repeating unit which has especially preferable lactone structure. By selecting the optimal lactone structure, the pattern profile and the dense dependence become good.

Wherein Rx is H, CH ₃ , CH ₂ OH or CF ₃

(B) It is preferable that a component has a repeating unit which has a hydroxyl group or a cyano group. This improves substrate adhesion and developer affinity. The repeating unit having a hydroxyl group or cyano group is preferably a repeating unit having an alicyclic hydrocarbon structure substituted with a hydroxyl group or cyano group. In the alicyclic hydrocarbon structure substituted with a hydroxyl group or cyano group, as the alicyclic hydrocarbon structure, an adamantyl group, diamantyl group, and norbornane group are preferable. As an alicyclic hydrocarbon structure substituted by the preferable hydroxyl group or cyano group, the partial structure represented by the following general formula (VIIa)-(VIId) is preferable.

In general formula (VIIa)-(VIIc),

R ₂ c to R ₄ c each independently represent a hydrogen atom, a hydroxyl group or a cyano group. However, R ₂ at least one of c ~ R ₄ c represents a hydroxyl group or a cyano group. Preferably, one or two of R ₂ c to R ₄ c are hydroxyl groups, and the rest are hydrogen atoms. In general formula (VIIa), More preferably, _two of R <_2> c ~ R <_4> c are hydroxyl groups, and the other is a hydrogen atom.

As a repeating unit which has the partial structure represented by general formula (VIIa)-(VIId), the repeating unit represented by the following general formula (AIIa)-(AIId) can be enumerated.

In general formula (AIIa)-(AIIb),

R ₁ c represents a hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl group.

R ₂ c ~ R ₄ c is the same meaning as R ₂ c ~ c R ₄ in the general formula (VIIa) ~ (VIIc).

As for content of the repeating unit which has an alicyclic hydrocarbon structure substituted by the hydroxyl group or the cyano group, 5-40 mol% is preferable with respect to all the repeating units in a polymer, More preferably, it is 5-30 mol%, More preferably, it is 10-25 Molar%.

Although the specific example of the repeating unit which has a hydroxyl group or a cyano group is listed below, this invention is not limited to these.

It is preferable that (B) component has a repeating unit which has alkali-soluble group. Examples of the alkali-soluble group include a carboxyl group, a sulfonamido group, a sulfonylimido group, a bissulfonylimido group, and an aliphatic alcohol (for example, a hexafluoroisopropanol group) in which the α position is substituted with an electron withdrawing group, and a repeat having a carboxyl group. It is more preferable to have a unit. By containing repeating units having alkali-soluble groups, the resolution in contact hole applications is increased. Examples of the repeating unit having an alkali-soluble group include a repeating unit in which an alkali-soluble group is directly bonded to the main chain of the resin, such as a repeating unit of acrylic acid or methacrylic acid, or a repeating unit in which an alkali-soluble group is bonded to the main chain of the resin through a linking group, It is preferable that both the polymerization initiator and the chain transfer agent having an alkali-soluble group are further introduced into the polymer chain at the time of polymerization, and the linking group may have a monocyclic or polycyclic cyclic hydrocarbon structure. Especially preferably, it is a repeating unit by acrylic acid and methacrylic acid.

As for content of the repeating unit which has alkali-soluble group, 1-20 mol% is preferable with respect to all the repeating units in a polymer, More preferably, it is 3-15 mol%, More preferably, it is 5-10 mol%.

Although the specific example of the repeating unit which has alkali-soluble group is shown below, this invention is not limited to this.

Wherein Rx is H, CH ₃ , CF ₃ , CH ₂ OH

It is a repeating unit which has at least 1 sort (s) of group chosen from lactone group, a hydroxyl group, a cyano group, and alkali-soluble group, More preferably, it is a repeating unit which has at least 2 selected from a lactone group, a hydroxyl group, a cyano group, and an alkali-soluble group And preferably a repeating unit having a cyano group and a lactone group.

(B) component may also contain the repeating unit which has an alicyclic hydrocarbon structure and does not show acid decomposability. This reduces the elution of low molecular weight components from the resist film to the immersion liquid during immersion exposure. As such a repeating unit, 1-adamantyl (meth) acrylate, diamantyl (meth) acrylate, tricyclo decanyl (meth) acrylate, cyclohexyl (meth) acrylate, etc. are mentioned, for example.

In addition to the above-mentioned repeating structural unit, the component (B) may have various repeating structural units for the purpose of adjusting dry etching resistance, standard developer aptitude, substrate adhesion, resist profile, and resolution, heat resistance, sensitivity, etc. which are general necessary characteristics of resist. have.

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

Thereby, the performance required for (B) component, especially,

(1) solubility in coating solvents,

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

(3) alkali developability,

(4) film loss (select hydrophilic, alkali-soluble group),

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

(6) dry etching resistance,

It is possible to fine tune the lights.

As such a monomer, for example, a compound having one addition polymerizable unsaturated bond selected from acrylic acid esters, methacrylic acid esters, acrylamides, methacrylamides, allyl compounds, vinyl ethers, vinyl esters, and the like. And so on.

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

In the component (B), the molar ratio of each repeating structural unit is appropriately set so as to control dry etching resistance, standard developer aptitude, substrate adhesion, resist profile, and resolution, heat resistance, sensitivity, and the like, which are generally necessary capabilities of the resist. do.

When the positive photosensitive composition of this invention is for ArF exposure, it is preferable that (B) component has an aromatic group from the point of transparency to ArF light.

As (B) component, Preferably, all the repeating units are comprised from the (meth) acrylate type repeating unit. In this case, any of the repeating units are all methacrylate-based repeating units, all of the repeating units are all acrylate-based repeating units, and all of the repeating units are either methacrylate-based repeating units or acrylate-based repeating units. Although it can be used, it is preferable that an acrylate type repeating unit is 50 mol% or less of all the repeating units. More preferably, 20-50 mol% of the (meth) acrylate type repeating unit which has an acid-decomposable group represented by general formula (I), 20-50 mol% of the (meth) acrylate type repeating unit which has a lactone structure, and a hydroxyl group Or 5-30 mol% of (meth) acrylate type repeating units which have an alicyclic hydrocarbon structure substituted by the cyano group, and 0-20 mol% of other (meth) acrylate type repeating units.

In the component (B), a resin having a repeating unit represented by the following general formula (I) and a repeating unit having at least one group selected from a lactone group, a hydroxyl group, a cyano group and an alkali-soluble group is a novel compound.

In general formula (I),

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

Ry ₁ and Ry ₂ each independently represent an alkyl group or a cycloalkyl group.

Rx represents an alkyl group having 2 or more carbon atoms or a cycloalkyl group.

Z represents an alkylene group.

In (B) component, resin which has a repeating unit represented with the following general formula (I-a) is a novel compound.

In general formula (I-a),

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

Ry ₁ and Ry ₂ each independently represent an alkyl group or a cycloalkyl group.

Ry ₃ represents a hydrogen atom or an alkyl group.

Z represents an alkylene group.

m1 represents 1 or 2.

In the repeating units (I) and (Ia), at least one of Ry ₁ and Ry ₂ is preferably an alkyl group having 2 or more carbon atoms.

The polymeric compound represented by the following general formula (I ') corresponding to repeating unit (I) is a novel compound.

In general formula (I '),

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

Ry ₁ and Ry ₂ each independently represent an alkyl group or a cycloalkyl group.

Rx represents an alkyl group having 2 or more carbon atoms or a cycloalkyl group.

Z represents an alkylene group.

The polymeric compound represented by the following general formula (I-a1) corresponding to a repeating unit (I-a) is a novel compound.

In general formula (I-a1),

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

Ry ₁ and Ry ₂ each independently represent an alkyl group or a cycloalkyl group.

Ry ₃ represents a hydrogen atom or an alkyl group.

Z represents an alkylene group.

m1 represents 1 or 2.

In the polymerizable compound (I ') and (I-a1), at least one of Ry ₁ and Ry ₂ is preferably an alkyl group having 2 or more carbon atoms.

(B) A component can be synthesize | combined according to a normal 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 species and an initiator in a solvent, and the dropping polymerization method which adds the solution of a monomer species and an initiator dropwise to a heating solvent over 1 to 10 hours, etc. These are listed, and 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, ester solvents such as ethyl acetate, dimethylformamide, The solvent which melt | dissolves the composition of this invention, such as amide solvents, such as dimethylacetamide, and propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, and cyclohexanone mentioned later is 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. This suppresses generation of particles during storage.

It is preferable to perform a polymerization reaction in inert gas atmosphere, such as nitrogen and argon. As a polymerization initiator, superposition | polymerization is started using a commercial radical initiator (azo initiator, a 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. An initiator is added or divided and added as desired, and after completion | finish of reaction, it puts into a solvent and collect | recovers a desired polymer by methods, such as powder or solid recovery. The reaction concentration is 5 to 50% by mass, preferably 10 to 30% by mass. Reaction temperature is 10-150 degreeC normally, Preferably it is 30-120 degreeC, More preferably, it is 60-100 degreeC.

The weight average molecular weight of the component (B) is preferably in the range of 1,000 to 200,000, more preferably 3,000 to 20,000, and most 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 developability deteriorates or the viscosity becomes high, thereby preventing the film forming property from deteriorating.

Dispersion degree (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 is, the better the resolution and the resist shape are, and the sidewalls of the resist pattern are smooth and the roughness is excellent.

When (B) component is used for the positive photosensitive composition which irradiates KrF excimer laser beam, an electron beam, X-rays, and high energy light rays (EUV etc.) with a wavelength of 50 nm or less, (B) component is repeating of general formula (I) It is preferable to further have a repeating unit which has a unit and a hydroxystyrene structure. As a repeating unit which has a hydroxy styrene structure, hydroxy styrene protected by o-, m-, p-hydroxy styrene, and / or an acid-decomposable group is mentioned. As the hydroxystyrene repeating unit protected with an acid-decomposable group, 1-alkoxyethoxystyrene and t-butylcarbonyloxystyrene are preferable. In addition to the repeating unit represented by general formula (I) and the repeating unit which has a hydroxystyrene structure, you may further have a repeating unit represented by general formula (II).

Although the specific example of resin which has a repeating unit represented by general formula (I) and the repeating unit which has a hydroxy styrene structure used for this invention is shown, this invention is not limited to this. In the specific examples, Xa ₁ represents a hydrogen atom, an alkyl group, a cyano group or a halogen atom.

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

In addition, in this invention, (B) component may be used by 1 type and may use multiple together.

A dissolution inhibiting compound having a molecular weight of 3000 or less having at least one selected from an alkali soluble group, a hydrophilic group and an acid decomposable group

To the positive photosensitive composition of the present invention, a dissolution inhibiting compound having a molecular weight of 3000 or less (hereinafter also referred to as a "dissolution inhibiting compound") having at least one selected from an alkali-soluble group, a hydrophilic group and an acid-decomposable group may be added.

Examples of the dissolution inhibiting compound include a compound having an alkali-soluble group such as a carboxyl group, a sulfonyl imido 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 amido group, a pyrrolidone group, and a sulfonamido group. The compound which has a hydrophilic group, or the compound which has an acid-decomposable group is preferable. As the acid-decomposable group, a group in which a carboxyl group or a hydroxyl group is protected with an acid-decomposable group protecting group is preferable. In order to prevent the permeability of 220 nm or less from decreasing as a dissolution inhibiting compound, 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 inhibiting compound, the carboxylic acid compound which has alicyclic hydrocarbon structure, such as adamantane (di) carboxylic acid, norbornanecarboxylic acid, and carboxylic acid, or the compound which protected this carboxylic acid with an acid-decomposable protecting group, saccharides, etc. The polyol or the compound which protected the hydroxyl group by the acid-decomposable protecting group is preferable.

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

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

Although the specific example of a dissolution inhibiting 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, or to suppress the diffusibility in the film | membrane of the acid generated by exposure.

As a basic compound, a nitrogen-containing basic compound and an onium salt compound can be mentioned.

As a structure of a preferable nitrogen-containing basic compound, the compound which has a partial structure represented by the following general formula (A)-(E) can be mentioned.

In general formula (A),

R ²⁵⁰ , R ²⁵¹ and R ²⁵² are each independently a hydrogen atom, an alkyl having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, and R ²⁵⁰ and R ²⁵¹ are bonded to each other to form a ring. You may form. These may have a substituent and as an alkyl group and cycloalkyl group which have a substituent, a C1-C20 aminoalkyl group or a C3-C20 aminocycloalkyl group, a C1-C20 hydroxyalkyl group, or a C3-C20 hydroxycycloalkyl group Is preferred.

In addition, these may contain an oxygen atom, a sulfur atom and a nitrogen atom in the alkyl chain.

In general formula (E),

R ²⁵³ , R ²⁵⁴ , R ²⁵⁵ and R ²⁵⁶ each independently represent a C 1-6 alkyl group or a C 3-6 cycloalkyl group.

Examples of preferred compounds include guanidine, aminopyrrolidine, pyrazole, pyrazoline, piperazine, aminomorpholine, aminoalkylmorpholine and piperidine, and may have a substituent. As more preferable compounds, compounds having imidazole structure, diazabicyclo structure, onium hydroxide structure, oniumcarboxylate structure, trialkylamine structure, aniline structure and pyridine structure, alkylamines having hydroxyl groups and / or ether bonds Derivatives, aniline derivatives having hydroxyl groups and / or ether bonds, and the like.

Examples of the compound having an imidazole structure include imidazole, 2,4,5-triphenylimidazole, benzimidazole, 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] undeca-7-ene and the like. Examples of the compound having an onium hydroxide structure include triarylsulfonium hydroxide, phenacylsulfonium hydroxide, and sulfonium hydroxide having a 2-oxoalkyl group, specifically triphenylsulfonium hydroxide and tris ( t-butylphenyl) sulfonium hydroxide, bis (t-butylphenyl) iodonium hydroxide, phenacylthiophenium hydroxide, 2-oxopropylthiophenium hydroxide, etc. can be mentioned. As a compound which has an onium carboxylate structure, the anion part of the compound which has an onium hydroxide structure consists of carboxylates, For example, acetate, adamantane-1-carboxylate, perfluoroalkyl carboxylate, etc. Can be enumerated. Examples of the compound having a trialkylamine structure include tri (n-butyl) amine, tri (n-octyl) amine, and the like. 2, 6- diisopropyl aniline, N, N- dimethylaniline, etc. can be mentioned as an aniline compound. Examples of the alkylamine derivative having a hydroxyl group and / or an ether bond include ethanol amine, diethanol amine, triethanol amine, tris (methoxyethoxyethyl) amine, and the like. Examples of aniline derivatives having a hydroxyl group and / or an ether bond include N, N-bis (hydroxyethyl) aniline and the like.

These basic compounds can be used individually or in 2 or more types. The usage-amount of a basic compound is 0.001-10 mass normally, Preferably it is 0.01-5 mass% based on solid content of a positive photosensitive composition. In order to acquire sufficient addition effect, 0.001 mass% or more is preferable, and 10 mass% or less is preferable at the point of a sensitivity or developability of a non-exposed part.

Fluorine and / or Silicone Surfactants

The positive photosensitive composition of the present invention preferably further contains any one or two or more kinds of fluorine and / or silicone-based surfactants (fluorine-based surfactants, silicone-based surfactants and surfactants containing both fluorine and silicon atoms). Do.

Since the positive photosensitive composition of the present invention contains a fluorine and / or silicone-based surfactant, it is possible to provide a resist pattern with low adhesion and development defects with good sensitivity and resolution when using an exposure light source of 250 nm or less, particularly 220 nm or less. Lose.

As these fluorine and / or silicone type surfactant, For example, Unexamined-Japanese-Patent No. 62-36663, Unexamined-Japanese-Patent No. 61-226746, Unexamined-Japanese-Patent No. 61-226745, Japan Patent Publication No. 62- Japanese Patent Application Laid-Open No. 170950, Japanese Patent Application Laid-Open No. 63-34540, Japanese Patent Application Laid-Open No. 7-230165, Japanese Patent Application Laid-Open No. 8-62834, Japanese Patent Application Laid-Open No. 9-54432, Japanese Patent Publication No. 9- Japanese Patent Application Laid-Open No. 5988, Japanese Patent Laid-Open No. 2002-277862, US Patent No. 557520, US Patent No. 5360692, US Patent No. 5529881, US Patent No. 5296330, US Patent No. 5436098, US Patent Surfactants described in Japanese Patent No. 5576143, US Pat. No. 5294511, US Pat. No. 5,824,451 can be enumerated, and commercially available surfactants described below may be used as they are.

As commercially available surfactants, for example, EFtop EF301, EF303, (manufactured by Shin-Akita Kasei KK), Florad FC430, 431 (manufactured by Sumitomo 3M Inc.), Megafac F171, F173, F176, F189, R08 (Dainippon Fluorine-based surfactants or silicones such as Ink Chemicals Inc.), Surflon S-382, SC101, 102, 103, 104, 105, 106 (manufactured by Asahi Glass Co., Ltd.), Troysol S-366 (manufactured by Troy Chemical) Surfactants may be enumerated. Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) can also be used as the silicone surfactant.

As the surfactant, in addition to the known ones described above, fluoro derivatives derived from fluoro aliphatic compounds produced by the telomerization method (also called telomer method) or the oligomerization method (also called oligomer method) Surfactants using polymers having aliphatic groups 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 and is irregularly distributed. Even if it exists, it may be block copolymerized. Examples of the poly (oxyalkylene) group include poly (oxyethylene) groups, poly (oxypropylene) groups, poly (oxybutylene) groups, and the like, and poly (oxyethylene, oxypropylene and oxyethylene). It may be a unit having an alkylene of a different chain length in a chain length such as a block linker) or a poly (block linker 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 above-mentioned (poly (oxyalkylene)) acrylate (or methacrylate) etc. may be a ternary or more copolymer which copolymerized simultaneously.

For example, commercially available surfactants include Megafac F178, F-470, F-473, F-475, F-476, and F-472 (manufactured by Dainippon Ink Chemicals Inc.). 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 (poly (oxyethylene) acrylate (or methacrylate) and (poly (oxypropylene) acrylate (or methacrylate) copolymer, acrylate (or methacrylate) having a C ₈ F ₁₇ group and Copolymers of (poly (oxyalkylene)) acrylates (or methacrylates), acrylates (or methacrylates) having C ₈ F ₁₇ groups, and (poly (oxyethylene) acrylates (or methacrylates) And copolymers of (poly (oxypropylene)) acrylate (or methacrylate).

The amount of fluorine and / or silicone-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).

solvent

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

As a solvent which can be used, for example, ethylene chloride, cyclohexanone, cyclopentanone, 2-heptanone, (gamma) -butyrolactone, methyl ethyl ketone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 2-meth Oxyethyl 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 And organic solvents such as propyl pyruvate, N, N-dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone and tetrahydrofuran.

In the present invention, the 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. Thereby, the solubility of a raw material becomes high and generation | occurrence | production of the particle | grains with time can be suppressed, and a favorable pattern profile is obtained. As a preferable functional group which a solvent contains, an ester group, a lactone group, a hydroxyl group, a ketone group, and a carbonate group 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 containing a hydroxyl group, and the solvent containing no 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 a ester structure, the solvent which has a lactone structure, and the solvent containing a hydroxyl group,

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

Thereby, generation | occurrence | production of the particle | grains at the time of resist liquid storage can be reduced, and generation | occurrence | production of the defect at the time of application | coating can be suppressed.

Examples of the solvent containing 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. Of these, propylene glycol monomethyl ether and ethyl lactate are particularly preferred.

As a solvent which does not contain a hydroxyl group, For example, propylene glycol monomethyl ether acetate, ethylethoxy propionate, 2-heptanone, (gamma) -butyrolactone, cyclohexanone, butyl acetate, N-methylpyrrolidone, N, N-dimethylacetamide, dimethyl sulfoxide and the like can be enumerated, among which propylene glycol monomethyl ether acetate, ethylethoxy propionate, 2-heptanone, γ-butyrolactone, cyclohexanone, acetic acid Butyl is particularly preferred, with propylene glycol monomethyl ether acetate, ethylethoxy propionate, 2-heptanone, cyclohexanone being particularly preferred.

Cyclohexanone, 2-heptanone, etc. are mentioned as a solvent which has a ketone structure, 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.

(Gamma) -butyrolactone is mentioned as a solvent which has a lactone structure.

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

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

The mixing ratio (mass) of the solvent having an ester structure and the solvent having a ketone structure is 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 70/30 to 99/1, preferably 80/20 to 99/1, and more preferably 90/10 to 99/1. A mixed solvent containing 70% by mass or more of a solvent having an ester structure is particularly preferable in terms of stability over time.

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

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

As a preferable form of these solvents, they are a solvent containing alkylene glycol monoalkyl ether carboxylate (preferably propylene glycol monomethyl ether acetate), Preferably the alkylene glycol monoalkyl ether carboxylate and the other solvent It is a mixed solvent and another solvent is at least 1 sort (s) of solvent chosen from the solvent which has at least 1 functional group chosen from a hydroxyl group, a ketone group, a lactone group, ester group, an ether group, and a carbonate group. A particularly preferable mixed solvent is a mixed solvent of at least one selected from ethyl lactate, γ-butyrolactone, propylene glycol monomethyl ether, butyl acetate and cyclohexanone and propylene glycol monomethyl ether acetate.

The development defect performance can be improved by selecting an optimal solvent.

<Other additives>

The positive type photosensitive composition of this invention can contain a dye, a plasticizer, surfactant other than the said fluorine and / or silicone type surfactant, a photosensitizer, the compound which promotes the solubility to a developing solution, etc. as needed.

The dissolution accelerator for the developer which can be used in the present invention is a low molecular weight compound having a molecular weight of 1,000 or less having two or more phenolic OH groups or one or more carboxyl groups. When it has a carboxy group, an alicyclic or aliphatic compound is preferable.

The preferable addition amount of these dissolution promoting compounds is 2-50 mass% with respect to acid-decomposable resin, More preferably, it is 5-30 mass%. 50 mass% or less is preferable at the point of suppressing image development residue and preventing pattern distortion at the time of image development.

Such phenol compounds having a molecular weight of 1000 or less are described with reference to methods described in, for example, Japanese Patent Application Laid-Open No. Hei 4-122938, Japanese Patent Application Laid-Open No. 2-28531, US Patent No. 4916210, European Patent No. 219294, and the like. It can be easily synthesized by those skilled in the art.

Specific examples of the alicyclic or aliphatic compound having a carboxyl group include carboxylic acid derivatives having a steroid structure such as cholic acid, dioxycholic acid, and lithocholic acid, adamantanecarboxylic acid derivatives, adamantane dicarboxylic acid, and cyclohexane. Although carboxylic acid, cyclohexane dicarboxylic acid, etc. are mentioned, It is not limited to these.

In this invention, surfactant other than fluorine and / or silicone type surfactant can also be added. Specifically, nonionics such as polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, polyoxyethylene polyoxypropylene block copolymers, sorbitan aliphatic esters, and polyoxyethylene sorbitan aliphatic esters Enumerated surfactants.

These surfactants may be added alone, or may be added in some combination.

(Pattern Forming Method)

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

For example, the positive photosensitive composition is applied and dried by a suitable coating method such as a spinner, a coater, or the like on a substrate (for example, silicon / silicon dioxide coating) which is used for the manufacture of precision integrated circuit elements to form a photosensitive film. .

The photosensitive film is passed through a predetermined mask to irradiate actinic rays or radiation, and preferably baked (heated), developed and rinsed. Thus, a good pattern can be obtained.

At the time of irradiation of actinic light or a radiation, you may perform exposure (liquid immersion exposure) by filling the liquid (liquid immersion medium) with refractive index higher than air between a photosensitive film and a lens. Thereby, resolution can be improved. 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 the case of performing liquid immersion exposure, an overcoat layer may be further formed on the photosensitive film so as not to directly contact the liquid immersion medium and the photosensitive film. As a result, elution of the composition from the photosensitive film to the liquid immersion medium is suppressed, and development defects are reduced.

The anti-reflection film may be formed on the substrate in advance before the photosensitive film is formed.

As the antireflection film, any of inorganic film types such as titanium, titanium dioxide, titanium nitride, chromium nitride, carbon, and 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 from Brewer Science, DUV-40 series and Shipley Company, such as AR-2, AR-3, and AR-5 can also be used.

Examples of the active light or the radiation include infrared light, visible light, ultraviolet light, far-ultraviolet light, X-rays, and electron beams. Lasers (248 nm), ArF excimer lasers (193 nm), F ₂ excimer lasers (157 nm), X-rays, electron beams, and the like. ArF excimer lasers, F ₂ excimer lasers, EUV (13 nm), and electron beams are preferable.

In the development process, an alkaline developer is used as follows. Examples of the alkaline developer of the positive photosensitive composition 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. Agents such as second amines such as butylamine, third amines such as triethylamine and methyldiethylamine, alcohol amines such as dimethylethanol amine and triethanol amine, 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.

In addition, alcohols and surfactants may be added to the alkaline developer in an appropriate amount.

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.

Example

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

The following polymeric compound was synthesize | combined using the method similar to the method of Unexamined-Japanese-Patent No. 2005-331918.

Xa ₂ : hydrogen atom, methyl group

Synthesis Example 1 (Synthesis of Resin (RA-1))

Under a stream of nitrogen, 10.5 g of cyclohexanone was placed in a three-neck flask, which was heated to 80 ° C. 4.3 g of γ-butyrolactone methacrylate, 5.9 g of 3-hydroxyadamantyl-1-methacrylate, 16.0 g of the following monomer (A), and a polymerization initiator V-601 (manufactured by Wako Pure) The solution obtained by dissolving 4 mol% in 83 g of cyclohexanone was added dropwise over 6 hours. After completion of the dropwise addition, the mixture was further reacted at 80 ° C for 2 hours. After the reaction solution was allowed to cool, it was added dropwise to a mixed solution of 900 m / methanol over 20 minutes, and the precipitated powder was collected and dried to obtain 20 g of resin (RA-1). The weight average molecular weight of obtained resin was 14200 in terms of standard polystyrene, and dispersion degree (Mw / Mn) was 1.90.

Other resins were synthesized using the same method. The weight average molecular weight was adjusted by changing the amount of a polymerization initiator.

Hereinafter, the structure of manufactured resin is shown.

Examples 1-28 and Comparative Examples 1-2

<Resist Manufacturing>

The components shown in following Tables 1-2 were dissolved in a solvent, the solution of 8 mass% of solid content concentration was manufactured, and this was filtered through the 0.03 micrometer polyethylene filter, and the positive resist solution was produced. The produced positive resist solution was evaluated by the following method, and the result is shown to Tables 1-2.

Resist Evaluation

On a silicon substrate subjected to hexamethyldisilazane treatment in a spin coater, an antireflection film DUV-42, manufactured by Brewer Science, was uniformly applied to 600 Å, dried on a hot plate at 100 ° C. for 90 seconds, and heated at 190 ° C. for 240 seconds. Done. Then, each positive resist solution was apply | coated with the spin coater, it dried for 60 second at 120 degreeC, and the resist film of 160 nm was formed.

This resist film was exposed with an ArF excimer laser stepper (NA = 0.75, 2/3 annular illumination) through a mask and heated on a hot plate at 120 ° C. for 60 seconds immediately after the exposure. Furthermore, it developed for 60 second at 23 degreeC with 2.38 mass% tetramethylammonium hydroxide aqueous solution, rinsed in pure water for 30 second, and dried, and obtained the line pattern.

Pattern collapse evaluation method:

When the line width of the line pattern formed by further increasing the exposure amount from the optimum exposure amount by making the exposure amount that reproduces the mask pattern of the 85 nm line and space as the optimum exposure amount, the line width was defined without resolving the pattern without collapse. The smaller the value, the more fine patterns are resolved without collapse, and the less the pattern collapse occurs.

Exposure Latitude Evaluation Method:

When the exposure amount was changed by setting the exposure amount that reproduces the mask pattern of the 85 nm line and space as the optimum exposure amount, the exposure dose width allowing the pattern size to be 85 nm +/- 10% was obtained, and this value was divided by the optimum exposure amount and expressed as a percentage. The larger the value, the smaller the change in performance due to the change in the exposure dose, and the better the exposure pattern.

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

[Acid generator]

[Basic compound]

TPSA: triphenylsulfonium acetate

DIA: 2,6-diisopropyl aniline

TEA: Triethanol Amine

DBA: N, N-dibutyl aniline

PBI: 2-phenylbenz imidazole

TMEA: tris (methoxyethoxyethyl) amine

PEA: N-phenyldiethanol amine

D-1: Triphenoxy ethoxyethylamine

D-2: N, N-diphenoxyethoxyethyl phenoxyethoxyethyl amine

D-3: 2-phenylbenz imidazole

D-4: dicyclohexyl methyl amine

[Surfactants]

W-1: Megafac F176 (manufactured by Dainippon Inc Chemicals Inc.) (fluorine-based)

W-2: Megafac R08 (manufactured by Dainippon Inc Chemicals Inc.) (fluorine and silicon based)

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

W-4: Troysol S-366 (Troy Chemical)

[solvent]

S1: Propylene Glycol Methyl Ether Acetate

S2: 2-heptanone

S3: cyclohexanone

S4: γ-butyrolactone

S5: Propylene Glycol Methyl Ether

S6: ethyl lactate

S7: Propylene Carbonate

From Tables 1-2, it is clear that the positive photosensitive composition of this invention is excellent in pattern collapse and exposure latitude.

(Immersion exposure)

<Resist Manufacturing>

The components of Table 1, Examples 1-28, and Comparative Examples 1 and 2 were melt | dissolved in the solvent, the solution of 6 mass% of solid content concentration was produced, and this was filtered with the 0.03 micrometer polyethylene filter, and the positive resist solution was produced. The prepared positive resist solution was evaluated by the following method.

<Resolution evaluation>

An organic antireflection film ARC29A (manufactured by Nissan Chemical Co., Ltd.) was applied onto the silicon wafer, and baked at 205 ° C. for 60 seconds to form an antireflection film of 78 nm. The positive resist solution prepared thereon was apply | coated, and it baked at 115 degreeC and 60 second, and formed the 140 nm resist film.

The wafer thus obtained was subjected to two-beam interference exposure using pure water as the immersion liquid (wet exposure). On the other hand, in two-beam interference exposure (wet exposure), as shown in FIG. 1, the laser 1, the diaphragm 2, the shutter 3, the three reflection mirrors 4, 5, 6, and the condenser lens 7 The wafer 10 was exposed to a wafer 10 having an antireflection film and a resist film through the prism 8 and the immersion liquid (pure water) 9. The wavelength of the laser 1 used 193 nm, and the prism 8 which forms the line and space of 65 nm was used. After heating at 115 ° C. for 90 seconds immediately after exposure, developing with tetramethyl ammonium hydroxide aqueous solution (2.38%) for 60 seconds, rinsing with pure water, and spin-drying in a resist pattern obtained by scanning electron microscope (Hitachi, Ltd. S-9260). When the compositions of Examples 1 to 28 were used, the line and space pattern was resolved at 65 nm without causing pattern collapse. Although the line and space were resolved at 65 nm using the compositions of Comparative Examples 1 and 2, pattern collapse was observed in some patterns.

It is clear that the positive photosensitive composition of the present invention has good image forming ability even in the exposure method through the immersion liquid.

1 is a schematic diagram of a two-beam interference exposure experimental apparatus.

***** Description of the symbols for the main parts of the drawings *****

1: laser 2: diaphragm 3: shutter

4, 5 and 6: Reflective mirror 7: Condensing lens

8: Prism 9: immersion liquid

10: wafer with antireflection film and resist film

11: wafer stage

Claims (12)

(A) a compound which generates an acid by irradiation of actinic light or radiation, and As a positive photosensitive composition containing resin which the dissolution rate with respect to alkaline developing solution increases by the action of (B) acid: Said (B) component is represented by the following general formula (I), and has a repeating unit which has an acid-decomposable group, The 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 and Ry ₂ each independently represent an alkyl group or a cycloalkyl group. Rx represents an alkyl group having 2 or more carbon atoms or a cycloalkyl group. Z represents an alkylene group.) The positive type photosensitive composition according to claim 1, wherein the component (B) further has a repeating unit having at least one group selected from a lactone group, a hydroxyl group, a cyano group and an alkali-soluble group. The positive photosensitive composition as claimed in claim 1, wherein the component (B) further has a repeating unit having a hydroxystyrene structure. The positive type photosensitive composition according to claim 1, wherein the component (B) further has a repeating unit represented by the general formula (I) and having an acid-decomposable group other than the repeating unit having an acid-decomposable group. A resin characterized by having a repeating unit represented by the following general formula (I) and a repeating unit having at least one group selected from a lactone group, a hydroxyl group, a cyano group and an alkali-soluble group.

(In general formula (I), Xa ₁ represents a hydrogen atom, an alkyl group, a cyano group or a halogen atom. Ry ₁ and Ry ₂ each independently represent an alkyl group or a cycloalkyl group. Rx represents an alkyl group having 2 or more carbon atoms or a cycloalkyl group. Z represents an alkylene group.) Resin characterized by having a repeating unit represented by the following general formula (I-a).

(In general formula (I-a), Xa ₁ represents a hydrogen atom, an alkyl group, a cyano group or a halogen atom. Ry ₁ and Ry ₂ each independently represent an alkyl group or a cycloalkyl group. Ry ₃ represents a hydrogen atom or an alkyl group. Z represents an alkylene group. m1 represents 1 or 2.) The resin according to claim 5 or 6, wherein at least one of Ry ₁ and Ry ₂ is an alkyl group having at least 2 carbon atoms. It is represented by the following general formula (I '), The polymeric compound 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 and Ry ₂ each independently represent an alkyl group or a cycloalkyl group. Rx represents an alkyl group having 2 or more carbon atoms or a cycloalkyl group. Z represents an alkylene group.) It is represented by the following general formula (I-a1), The polymeric compound characterized by the above-mentioned.

(In general formula (I-a1), Xa ₁ represents a hydrogen atom, an alkyl group, a cyano group or a halogen atom. Ry ₁ and Ry ₂ each independently represent an alkyl group or a cycloalkyl group. Ry ₃ represents a hydrogen atom or an alkyl group. Z represents an alkylene group. m1 represents 1 or 2.) The polymerizable compound according to claim 8 or 9, wherein at least one of Ry ₁ and Ry ₂ is an alkyl group having 2 or more carbon atoms. A process for forming a film from the positive photosensitive composition according to any one of claims 1 to 4, and exposing and developing the film. 12. The pattern forming method of claim 11, wherein the exposure is liquid immersion exposure.

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