JP4832165B2 - Positive photosensitive composition and pattern forming method using the same - Google Patents

Description

  The present invention relates to a positive photosensitive composition used in a semiconductor manufacturing process such as an IC, a circuit board such as a liquid crystal or a thermal head, and other photofabrication processes, and a pattern forming method using the same. is there. More specifically, the present invention relates to a positive photosensitive composition suitable for use as an exposure light source such as far ultraviolet rays of 250 nm or less, preferably 220 nm or less, and an irradiation source using an electron beam, and a pattern forming method using the same.

  The chemically amplified photosensitive composition generates an acid in the exposed area by irradiation with radiation such as far ultraviolet light, and the acid-catalyzed reaction causes the solubility of the active radiation irradiated area and non-irradiated area in the developer. This is a pattern forming material for changing the pattern to form a pattern on the substrate.

  When a KrF excimer laser is used as an exposure light source, a resin having a basic skeleton of poly (hydroxystyrene) having a small absorption mainly in the 248 nm region is used as a main component. A pattern is formed, which is a better system than the conventional naphthoquinone diazide / novolak resin system.

On the other hand, when a further short wavelength light source, for example, ArF excimer laser (193 nm) is used as the exposure light source, the compound having an aromatic group essentially shows a large absorption in the 193 nm region. It wasn't.
Therefore, an ArF excimer laser resist containing a highly transparent methacrylate resin in a wavelength region of 200 nm or less has been developed. Japanese Patent Application Laid-Open No. 4-226461 describes a resist composition containing an acid-decomposable resin having a methacrylate structure. However, with the miniaturization of patterns, it is necessary to reduce the resist film thickness, and resist dry etching resistance is required. Patent Document 1 (Japanese Patent No. 297998) and Patent Document 2 (Japanese Patent Laid-Open No. 2001-188347) describe a resin containing a repeating unit having a bridged alicyclic hydrocarbon such as an amantane structure. However, although the DE resistance can be improved by increasing the carbon density, it is extremely difficult to achieve both the overall performance as a resist, such as the development defect performance and the pattern formation performance being deteriorated. Furthermore, when forming a fine pattern such as a line width of 100 nm or less, even if the resolution performance is excellent, the formed line pattern collapses, resulting in a pattern collapse problem that becomes a defect during device manufacturing, Therefore, improvement of the line edge roughness performance of the line pattern has been demanded.

Here, the line edge roughness means that the resist line pattern and the edge of the substrate interface exhibit irregular shapes in a direction perpendicular to the line direction due to the characteristics of the resist. When this pattern is observed from directly above, the edges appear to be uneven (± several nm to several tens of nm). Since the unevenness is transferred to the substrate by an etching process, if the unevenness is large, an electrical characteristic defect is caused and the yield is lowered.
Japanese Patent No. 2973998 JP 2001-188347 A

  Accordingly, an object of the present invention is to provide a positive photosensitive composition having improved line edge roughness and pattern collapse even in the formation of a fine pattern (particularly, a line width of 100 nm or less) and a pattern forming method using the same. It is in.

That is, the present invention is achieved by the following configuration.
[1]
(A) a resin containing a repeating unit represented by formula (I) and a repeating unit having a lactone structure, which decomposes by the action of an acid and increases the solubility in an alkali developer, and (B) A positive photosensitive composition containing a compound that generates an acid upon irradiation with actinic rays or radiation.

In general formula (I):
Rx represents a hydrogen atom, an alkyl group or a cyano group.
Ra ₁ and Ra ₂ each independently represent a hydrogen atom or an organic group.
Ra ₃ and Ra ₄ each independently represents an unsubstituted alkyl group, cycloalkyl group, aryl group or aralkyl group.
Ra ₃ and Ra ₄ may be bonded to each other to form a ring structure.
X represents a single bond or an alkylene group.
Y represents an atomic group necessary to form a monocyclic hydrocarbon group together with the carbon atom C _1.
n represents 1 or 2.
[2]
The positive photosensitive composition as described in [1] above, wherein the resin (A) further contains a repeating unit having an acid-decomposable group having an alicyclic hydrocarbon structure.
[3]
The positive photosensitive composition as described in [1] or [2] above, wherein the resin (A) contains a repeating unit having a partial structure represented by the following general formula (VIIa).

In General Formula (VIIa), R _{2c to} R _4c each independently represent a hydrogen atom, a hydroxyl group, or a cyano group. However, at least one of R _{2c to} R _4c represents a hydroxyl group or a cyano group.
[4]
A photosensitive film formed using the positive photosensitive composition according to any one of [1] to [3].
[5]
A pattern forming method comprising exposing and developing the photosensitive film according to the above [4].
[6]
The pattern forming method as described in [5] above, wherein the photosensitive film is exposed through an immersion medium.
The present invention is the invention according to the above [1] to [6], but is described below including other matters for reference.
<1>
(A) a resin containing a repeating unit represented by the general formula (I), which decomposes by the action of an acid and increases the solubility in an alkali developer, and (B) an acid by irradiation with actinic rays or radiation. A positive photosensitive composition containing a compound capable of generating.

In general formula (I):
Rx represents a hydrogen atom, an alkyl group or a cyano group.
Ra ₁ and Ra ₂ each independently represent a hydrogen atom or an organic group.
Ra ₃ and Ra ₄ each independently represents an organic group.
Ra ₃ and Ra ₄ may be bonded to each other to form a ring structure.
X represents a single bond or an alkylene group.
Y represents an atomic group necessary to form a monocyclic hydrocarbon group together with the carbon atom C _1.
n represents 1 or 2.
<2>
The positive photosensitive composition as described in <1>, wherein the resin (A) further contains a repeating unit having an acid-decomposable group having an alicyclic hydrocarbon structure.
<3>
The positive photosensitive composition as described in <1> or <2>, wherein the resin (A) further contains a repeating unit having a lactone structure.
<4>
<1>-<3> The pattern forming method characterized by forming a photosensitive film | membrane using the positive photosensitive composition in any one of <3>, and exposing and developing this photosensitive film | membrane.
<5>
A resin containing a repeating unit represented by formula (I).

In general formula (I):
Rx represents a hydrogen atom, an alkyl group or a cyano group.
Ra ₁ and Ra ₂ each independently represent a hydrogen atom or an organic group.
Ra ₃ and Ra ₄ each independently represents an organic group.
Ra ₃ and Ra ₄ may be bonded to each other to form a ring structure.
X represents a single bond or an alkylene group.
Y represents an atomic group necessary to form a monocyclic hydrocarbon group together with the carbon atom C _1.
n represents 1 or 2.
<6>
A polymerizable compound represented by the general formula (II).

In general formula (II):
Rx represents a hydrogen atom, an alkyl group or a cyano group.
Ra ₁ and Ra ₂ each independently represent a hydrogen atom or an organic group.
Ra ₃ and Ra ₄ each independently represents an organic group.
Ra ₃ and Ra ₄ may be bonded to each other to form a ring structure.
X represents a single bond or an alkylene group.
Y represents an atomic group necessary to form a monocyclic hydrocarbon group together with the carbon atom C _1.
n represents 1 or 2.

  Even in the formation of a fine pattern having a line width of 100 nm or less by the positive photosensitive composition using the compound of the present invention and a resin containing the compound and the pattern forming method using the same, the sensitivity, resolution, line edge roughness, Pattern collapse is significantly reduced, and a good pattern can be formed with high productivity.

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

[1] Resin that decomposes by the action of acid and increases its solubility in an alkaline developer (hereinafter also referred to as “resin (A))”
The positive photosensitive composition of the present invention contains a repeating unit having a structure represented by the general formula (I), which decomposes by the action of an acid and increases the solubility in an alkaline developer (acid decomposition). Resin).

In general formula (I):
n represents 1 or 2.
Rx represents a hydrogen atom, an alkyl group or a cyano group.
As the alkyl group in Rx, a linear or branched alkyl group having 1 to 4 carbon atoms is preferable, and a methyl group, CH ₂ OH (hydroxymethyl group), CF _{3 and the} like are preferable.

Ra ₁ and Ra ₂ each independently represent a hydrogen atom or an organic group.
Examples of the organic group in Ra ₁ and Ra ₂ include, independently, a cyano group, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, an alkoxyalkyl group, and the like.
As the alkyl group, a linear or branched alkyl group having 1 to 20 carbon atoms is preferable. Specifically, a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-isobutyl group, Examples thereof include chain alkyl groups such as t-butyl group, hexyl group, octyl group and dodecyl group.
The cycloalkyl group is preferably a cycloalkyl group having 20 or less carbon atoms, such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, norbornyl group, adamantyl group, tetracyclododecyl group, tricyclodecyl group, etc. Is mentioned.
Examples of the aryl group include a phenyl group, a naphthyl group, a thiophene group, a furan group, a pyrrole group, and an indole group.
Examples of the aralkyl group include a group in which the aryl group is linked with an alkyl group having 1 to 4 carbon atoms.
The alkoxyalkyl group is preferably a linear, branched or cyclic alkoxyalkyl group having 1 to 20 carbon atoms, specifically, a methoxymethyl group, an ethoxymethyl group, an n-propoxymethyl group, an i-propoxymethyl group, or an n-butoxy. Examples thereof include linear, branched or cyclic alkoxyalkyl groups such as methyl group, 2-methylpropoxyethyl group, 1-methylpropoxymethyl group, tetrahydrofuranyl group, tetrahydropyranyl group, and menthoxymethyl.
Ra ₁ and Ra ₂ are preferably each independently a hydrogen atom, an alkyl group, a cycloalkyl group, or an alkoxyalkyl group, and more preferably a hydrogen atom or an alkyl group. Still more preferably, they are a hydrogen atom, a methyl group, or an ethyl group. Most preferably, it is a hydrogen atom.

Ra ₃ and Ra ₄ each independently represents an organic group.
As the organic group in Ra ₃ and Ra ₄ , a cyano group, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, and the like can be given independently.
As the alkyl group, a linear or branched alkyl group having 1 to 20 carbon atoms is preferable. Specifically, a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-isobutyl group, Examples thereof include chain alkyl groups such as t-butyl group, hexyl group, octyl group and dodecyl group.
The cycloalkyl group is preferably a cycloalkyl group having 20 or less carbon atoms, such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, norbornyl group, adamantyl group, tetracyclododecyl group, tricyclodecyl group, etc. Is mentioned.
Examples of the aryl group include a phenyl group, a naphthyl group, a thiophene group, a furan group, a pyrrole group, and an indole group.
Examples of the aralkyl group include groups in which the aryl group is linked with an alkyl group having 1 to 4 carbon atoms.
Ra ₃ and Ra ₄ are each independently preferably an alkyl group or a cycloalkyl group, more preferably a linear or branched alkyl group having 1 to 10 carbon atoms, or a cycloalkyl group having 10 or less carbon atoms. . More preferably, a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-isobutyl group, a t-butyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, or a cyclohexyl group, Most preferred is a methyl group or an ethyl group.
Ra ₃ and Ra ₄ may be bonded to each other to form a ring structure.
The ring structure formed by combining Ra ₃ and Ra ₄ with each other may be monocyclic or polycyclic, and examples thereof include cycloalkyl having 3 to 20 carbon atoms. Preferably, it is a monocyclic or polycyclic cycloalkyl having 3 to 10 carbon atoms. More preferred examples include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl and the like. Most preferred are cyclopentyl and cyclohexyl.

  X represents a single bond or an alkylene group, and the alkylene group is preferably a linear or branched alkylene group having 1 to 10 carbon atoms, and examples thereof include the following general formula (I-1).

In general formula (I-1),
Rb ₁ and Rb ₂ each represent a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, and a cycloalkyl group having 1 to 6 carbon atoms. Examples of the alkyl group include chain alkyl groups such as a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-isobutyl group, a t-butyl group, and a hexyl group. Examples of the cycloalkyl group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group.
X is preferably a single bond or a chain alkylene group having 1 to 5 carbon atoms. More preferred are a single bond, a methylene group, an ethylene group, and a 1-methyl-1,1-ethylene group. Most preferred is a single bond.

Y represents an atomic group necessary for forming a monocyclic hydrocarbon group together with the carbon atom C ₁ , preferably a monocyclic hydrocarbon group having 1 to 10 carbon atoms, specifically, a cyclopropyl group, A cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclononyl group, and the like can be given. Preferred are a cyclopropyl group, a cyclobutyl group, a cyclopentyl group or a cyclohexyl group, and a cycloheptyl group, and most preferred is a cyclopentyl group or a cyclohexyl group.

The repeating unit represented by the general formula (I) may or may not have acid decomposability, but does not have acid decomposability, that is, Ra ₁ is a hydrogen atom. Is more preferable.

  Specific examples of the repeating unit represented by formula (I) are shown below, but are not limited thereto.

  In the resin (A), the content of the repeating unit represented by the general formula (I) is preferably 5 to 60 mol%, more preferably 5 to 50 mol%, still more preferably 10 to 40 in all repeating structural units. Mol%.

  The repeating unit can also be obtained by polymerizing the polymerizable compound of the present invention represented by the following general formula (II).

In the general formula (II), Rx, Ra ₁ , Ra ₂ , Ra ₃ , Ra ₄ , the ring structure formed by combining Ra ₃ and Ra ₄ , X, Y, and n are respectively represented by the general formula (I ) Is synonymous with that described above.

  Although the specific example of the polymeric compound of this invention represented by general formula (II) below is shown, it is not limited to these.

  The polymerizable compound can be obtained, for example, by reacting a corresponding carboxylic acid ester or ketone with a corresponding alkylating agent and then introducing a polymerizable group.

In the above formula, Rc ₁ , Rc ₂ and Rc ₃ have the same meanings as described for the polymerizable compound represented by the general formula (II).

Resin (A) is a resin (acid-decomposable resin) that is decomposed by the action of an acid and has increased solubility in an alkali developer, and is a group (acid-decomposable) that decomposes by the action of an acid to produce an alkali-soluble group. Group).
That is, the resin (A) may have an acid-decomposable group in the main chain or side chain of the resin, or in both the main chain and the side chain, but it is preferable to have the group in the side chain.
A preferred group as the acid-decomposable group is a group in which a hydrogen atom of an alkali-soluble group such as a —COOH group or a —OH group is substituted with a group capable of leaving with an acid.
Examples of the group leaving with 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, R _{36 to} R ₃₉ each independently represents an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or an alkenyl group. R ₃₆ and R ₃₇ , R ₃₆ and R ₃₉ may be bonded to each other to form a ring.
R _{01 and} R ₀₂ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group or an alkenyl group.
In the present invention, the acid-decomposable group is preferably an acetal group or a tertiary ester group.
Although resin (A) may have an acid-decomposable group in any repeating unit, it is preferable to have in the repeating unit which has an alicyclic hydrocarbon structure mentioned later.

When the positive photosensitive composition of the present invention is irradiated with ArF excimer laser light in particular, the resin (A) has a repeating unit represented by the general formula (I) and further has an alicyclic hydrocarbon structure. It is preferable to contain the repeating unit which has.
Further, when the general formula (I) does not have acid decomposability, that is, when Ra ₂ is hydrogen, in the repeating unit having an alicyclic hydrocarbon structure, the alicyclic hydrocarbon structure is decomposed by the action of an acid, It is preferably contained in the leaving group in the group that generates an alkali-soluble group in the resin together with the leaving group (acid-decomposable group).

  As the repeating unit having an alicyclic hydrocarbon structure, a repeating unit having a partial structure containing an alicyclic hydrocarbon represented by the following general formula (pI) to general formula (pV) and the following general formula (II-AB) At least one selected from the group of repeating units shown is preferred.

In general formulas (pI) to (pV),
R ₁₁ represents a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group or a sec-butyl group, and Z is an atom necessary for forming a cycloalkyl group together with a carbon atom. Represents a group.
R _{12 to} R ₁₆ each independently represents a linear or branched alkyl group or cycloalkyl group having 1 to 4 carbon atoms, provided that at least one of R _{12 to} R ₁₄ , or R ₁₅ , Any of R ₁₆ represents a cycloalkyl group.
R _{17 to} R ₂₁ each independently represents a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or a cycloalkyl group, provided that at least one of R _{17 to} R ₂₁ is cyclo Represents an alkyl group. Further, either R ₁₉ or R ₂₁ represents a linear or branched alkyl group or cycloalkyl group having 1 to 4 carbon atoms.
R _{22 to} R ₂₅ each independently represents a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or a cycloalkyl group, provided that at least one of R _{22 to} R ₂₅ is cyclo Represents an alkyl group. R ₂₃ and R ₂₄ may be bonded to each other to form a ring.

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

  The general formula (II-AB) is more preferably the following general formula (II-AB1) or general formula (II-AB2).

In the general formulas (II-AB1) and (II-AB2),
R ₁₃ ′ to R ₁₆ ′ each independently represents a hydrogen atom, a halogen atom, a cyano group, —COOH, —COOR ₅ , a group that decomposes by the action of an acid, —C (═O) —XA′—R. ₁₇ ′ represents an alkyl group or a cycloalkyl group.
Here, R ₅ represents an alkyl group, a cycloalkyl group, or a group having a lactone structure.
X represents an oxygen atom, a sulfur atom, -NH -, - NHSO ₂ - or an -NHSO ₂ NH-.
A ′ represents a single bond or a divalent linking group.
Further, at least two of R ₁₃ ′ to R ₁₆ ′ may be bonded to form a ring. n represents 0 or 1.
R ₁₇ ′ represents —COOH, —COOR ₅ , —CN, a hydroxyl group, an alkoxy group, —CO—NH—R ₆ , —CO—NH—SO ₂ —R ₆ or a group having a lactone structure.
R ₆ represents an alkyl group or a cycloalkyl group.

In the general formulas (pI) to (pV), the alkyl group in R _{12 to} R ₂₅ represents a linear or branched alkyl group having 1 to 4 carbon atoms.

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

  Preferred cycloalkyl groups include adamantyl group, noradamantyl group, decalin residue, tricyclodecanyl group, tetracyclododecanyl group, norbornyl group, cedrol group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, A cyclodecanyl group and a cyclododecanyl group can be mentioned. More preferable examples include an adamantyl group, norbornyl group, cyclohexyl group, cyclopentyl group, tetracyclododecanyl group, and tricyclodecanyl group.

  As further substituents of these alkyl groups and cycloalkyl groups, alkyl groups (1 to 4 carbon atoms), halogen atoms, hydroxyl groups, alkoxy groups (1 to 4 carbon atoms), carboxyl groups, alkoxycarbonyl groups (carbon numbers) 2-6). Examples of the substituent that the alkyl group, alkoxy group, alkoxycarbonyl group and the like may further have include a hydroxyl group, a halogen atom, and an alkoxy group.

  The structure represented by the general formulas (pI) to (pV) can be used as a protective group for an alkali-soluble group to form an acid-decomposable group. Examples of the alkali-soluble group include various groups known in this technical field.

  Specific examples include a structure in which a hydrogen atom of a carboxylic acid group, a sulfonic acid group, a phenol group, or a thiol group is substituted with a structure represented by the general formulas (pI) to (pV), preferably a carboxylic acid Group, a hydrogen atom of a sulfonic acid group is substituted with a structure represented by general formulas (pI) to (pV).

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

Here, R represents a hydrogen atom, a halogen atom, or a linear or branched alkyl group having 1 to 4 carbon atoms. A plurality of R may be the same or different.
A represents a single bond, an alkylene group, an ether group, a thioether group, a carbonyl group, an ester group, an amide group, a sulfonamide group, a urethane group, or a urea group, or a combination of two or more groups. Represents. A single bond is preferable.
Rp1 represents any group of the above formulas (pI) to (pV).

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

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

Examples of the halogen atom in R ₁₁ ′ and R ₁₂ ′ include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom.

Examples of the alkyl group in R ₁₁ ′ and R ₁₂ ′ include a linear or branched alkyl group having 1 to 10 carbon atoms.

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

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

The alicyclic hydrocarbon skeleton may have a substituent. Examples of such a substituent include R ₁₃ ′ to R ₁₆ ′ in the general formula (II-AB1) or (II-AB2).

  In the acid-decomposable resin, the group capable of decomposing by the action of an acid is a repeating unit having a partial structure containing an alicyclic hydrocarbon represented by the general formula (pI) to general formula (pV), a general formula (II- It can be contained in at least one repeating unit among the repeating unit represented by AB) and the repeating unit of the copolymerization component described later.

Various substituents of R ₁₃ ′ to R ₁₆ ′ in the general formula (II-AB1) or the general formula (II-AB2) are atomic groups for forming an alicyclic structure in the general formula (II-AB). It can also be a substituent of the atomic group Z for forming a bridged alicyclic structure.

  Specific examples of the repeating unit represented by the general formula (II-AB1) or (II-AB2) include the following specific examples, but the present invention is not limited to these specific examples.

  The acid-decomposable resin preferably has a lactone group. As the lactone group, any group can be used as long as it contains a lactone structure, but it is preferably a group containing a 5- to 7-membered ring lactone structure. Those in which other ring structures are condensed to form a spiro structure are preferred. It is more preferable to have a repeating unit having a group having a lactone structure represented by any of the following general formulas (LC1-1) to (LC1-16). Further, a 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). By using a specific lactone structure, line edge roughness, Development defects are improved.

The lactone structure moiety 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, and a carboxyl group. , Halogen atom, hydroxyl group, cyano group, acid-decomposable group and the like. When n2 is 2 or more, a plurality of Rb ₂ may be the same or different, and a plurality of Rb ₂ may be bonded to form a ring.

As the repeating unit having a group having a lactone structure represented by any of the general formulas (LC1-1) to (LC1-16), R _{13 in the} above general formula (II-A) or (II-B) may be used. Wherein at least one of 'to R ₁₆ ' has a group represented by the general formulas (LC1-1) to (LC1-16) (for example, R _{5 of} -COOR ₅ is represented by the general formulas (LC1-1) to (LC1) -16) or a repeating unit represented by the following general formula (AI).

In General Formula (AI), Rb ₀ represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms. Preferred substituents that the alkyl group represented by Rb ₀ may have include a hydroxyl group and a halogen atom.

Examples of the halogen atom for Rb ₀ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R _b0 is preferably a hydrogen atom or a methyl group.

Ab is an alkylene group, a divalent linking group having a monocyclic or polycyclic alicyclic hydrocarbon structure, a single bond, an ether group, an ester group, a carbonyl group, a carboxyl group, or a divalent group obtained by combining these. To express. Preferably a single bond, -Ab ₁ -CO ₂ - is a linking group represented by.
Ab ₁ is a linear, branched alkylene group, monocyclic or polycyclic cycloalkylene group, preferably a methylene group, an ethylene group, a cyclohexyl group, an adamantyl group, or a norbornyl group.

  V represents a group represented by any one of the general 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. One optical isomer may be used alone, or a plurality of optical isomers may be mixed and used. When one kind of optical isomer is mainly used, the optical purity (ee) thereof is preferably 90 or more, more preferably 95 or more.
Specific examples of the repeating unit having a group having a lactone structure are given below, but the present invention is not limited thereto.

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

  The acid-decomposable resin preferably contains a repeating unit having an alicyclic hydrocarbon structure substituted with a polar group. This improves the substrate adhesion and developer compatibility. The alicyclic hydrocarbon structure of the alicyclic hydrocarbon structure substituted with a polar group is preferably an adamantyl group, a diamantyl group, or a norbornane group. The polar group is preferably a hydroxyl group or a cyano group. As the alicyclic hydrocarbon structure substituted with a preferable polar group, partial structures represented by (VIIa) to (VIId) are preferable.

In general formulas (VIIa) to (VIIc), R _{2c to} R _4c each independently represents a hydrogen atom, a hydroxyl group, or a cyano group. However, at least one of R _{2c to} R _4c represents a hydroxyl group or a cyano group. Preferably, one or two of R _{2c to} R _4c are a hydroxyl group and the rest are hydrogen atoms. In (VIIa), more preferably, two of R _{2c to} R _4c are a hydroxyl group and the remainder is a hydrogen atom.

As the repeating unit having a group represented by the general formulas (VIIa) to (VIId), at least one of R ₁₃ ′ to R ₁₆ ′ in the general formula (II-A) or (II-B) is the above. Those having a group represented by the general formula (VII) (for example, R _{5 of} —COOR ₅ represents a group represented by the general formula (VII)), or a repeating unit represented by the following general formula (AII) Can be mentioned.

In general formula (AIIa) or (AIIb), R _1c represents a hydrogen atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group.

  Specific examples of the repeating unit having a structure represented by the general formula (AIIa) or (AIIb) are shown below, but the present invention is not limited thereto.

The acid-decomposable resin may contain a repeating unit represented by the following general formula (VIII).

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

  Examples of the repeating unit represented by the general formula (VIII) include the following specific examples, but the present invention is not limited thereto.

  The acid-decomposable resin preferably has a repeating unit having an alkali-soluble group, and more preferably has a repeating unit having a carboxyl group. By containing this, the resolution in contact hole applications increases. The repeating unit having a carboxyl group includes a repeating unit in which a carboxyl group is directly bonded to the main chain of the resin, such as a repeating unit of acrylic acid or methacrylic acid, or a carboxyl group in the main chain of the resin through a linking group. Either a repeating unit that is bonded, or a polymerization initiator or chain transfer agent having an alkali-soluble group is introduced at the end of the polymer chain at the time of polymerization, and the linking group is a monocyclic or polycyclic hydrocarbon. You may have a structure. Most preferred are acrylic acid and methacrylic acid.

  The acid-decomposable resin may further have a repeating unit having 1 to 3 groups represented by the general formula (F1). This improves line edge roughness performance.

In general formula (F1), R _{50 to} R ₅₅ each independently represents a hydrogen atom, a fluorine atom or an alkyl group. However, at least one of R _{50 to} R ₅₅ represents a fluorine atom or an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom. Rx represents a hydrogen atom or an organic group (preferably an acid-decomposable protecting group, an alkyl group, a cycloalkyl group, an acyl group, or an alkoxycarbonyl group).

The alkyl group of R _{50 to} R ₅₅ may be substituted with a halogen atom such as a fluorine atom, a cyano group, etc., preferably an alkyl group having 1 to 3 carbon atoms, such as a methyl group or a trifluoromethyl group. be able to. R _{50 to} R ₅₅ are preferably all fluorine atoms.

  Examples of the organic group represented by Rx include an acid-decomposable protective group and an optionally substituted alkyl group, cycloalkyl group, acyl group, alkylcarbonyl group, alkoxycarbonyl group, alkoxycarbonylmethyl group, alkoxymethyl group. , 1-alkoxyethyl group is preferable.

  The repeating unit having the general formula (F1) is preferably a repeating unit represented by the following general formula (F2).

In general formula (F2),
Fx represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms. Preferable substituents that the Fx alkyl group may have include a hydroxyl group and a halogen atom.
Fa represents a single bond or a linear or branched alkylene group (preferably a single bond).
Fb represents a monocyclic or polycyclic hydrocarbon group.
Fc represents a single bond or a linear or branched alkylene group (preferably a single bond or a methylene group).
F1 represents a group represented by the general formula (F1).
P1 represents 1-3.
The cyclic hydrocarbon group for Fb is preferably a cyclopentyl group, a cyclohexyl group, or a norbornyl group.

  Specific examples of the repeating unit having the structure of the general formula (F1) are shown.

  The acid-decomposable resin may further contain a repeating unit that has an alicyclic hydrocarbon structure and does not exhibit acid-decomposability. This can reduce the elution of low molecular components from the resist film to the immersion liquid during immersion exposure. Examples of such a repeating unit include 1-adamantyl (meth) acrylate, tricyclodecanyl (meth) acrylate, and cyclohexyl (meth) acrylate.

  In addition to the above repeating structural units, acid-decomposable resins adjust dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and general required properties of resist, such as resolution, heat resistance, and sensitivity. For this purpose, various repeating structural units can be contained.

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

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

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

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

  In the acid-decomposable resin, the content molar ratio of each repeating structural unit has a dry etching resistance, standard developer suitability, substrate adhesion, pattern profile, and general required performance such as resolution, heat resistance, and sensitivity. Appropriately set for adjustment.

Preferred embodiments of the acid-decomposable resin include the following.
(1) What contains the repeating unit which has a partial structure containing the alicyclic hydrocarbon represented by said general formula (pI)-(pV) (side chain type). Preferably those containing (meth) acrylate repeating units having a structure of (pI) to (pV).
(2) Containing repeating unit represented by general formula (II-AB) (main chain type) However, in (2), the following are further exemplified.
(3) A repeating unit represented by the general formula (II-AB), a maleic anhydride derivative and a (meth) acrylate structure (hybrid type)

  In the resin (A), the content of the repeating unit having a group represented by the general formula (I) is preferably 1 to 50 mol%, more preferably 5 to 40 mol% in all repeating structural units as a total amount. More preferably, it is 10-30 mol%.

  In the resin (A), the content of the repeating unit having an acid-decomposable group is preferably 10 to 60 mol%, more preferably 20 to 50 mol%, still more preferably 25 to 40 mol% in all repeating structural units. is there.

  In the resin (A), the content of the repeating unit having a partial structure containing an alicyclic hydrocarbon represented by the general formulas (pI) to (pV) is preferably 20 to 70 mol% in all repeating structural units, More preferably, it is 20-50 mol%, More preferably, it is 25-40 mol%.

  In the resin (A), the content of the repeating unit represented by the general formula (II-AB) is preferably 10 to 60 mol%, more preferably 15 to 55 mol%, still more preferably 20 in all repeating structural units. ˜50 mol%.

As for content of the repeating unit which has a lactone structure, 10-70 mol% is preferable in all the repeating structural units, More preferably, it is 15-60 mol%, More preferably, it is 20-50 mol%.
The content of the repeating unit having an alicyclic hydrocarbon structure substituted with a polar group is preferably 5 to 50 mol%, more preferably 10 to 40 mol%, still more preferably 15 to 30 mol% in all repeating structural units. It is.

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

When the composition of the present invention is for ArF exposure, the resin preferably has no aromatic group from the viewpoint of transparency to ArF light.
The resin (A) is preferably one in which all of the repeating units are composed of (meth) acrylate repeating units. In this case, all of the repeating units may be methacrylate, all of the repeating units may be acrylate, or a mixture of methacrylate / acrylate, but the acrylate repeating unit is preferably 50 mol% or less of the entire repeating unit.
More preferably, when the repeating unit represented by the general formula (I) does not exhibit acid decomposability, that is, when R _a2 is a hydrogen atom, the alicyclic hydrocarbon represented by the general formula (pI) to (pV) is A terpolymer having 20 to 50% of repeating units having a partial structure, 20 to 50% of repeating units having the lactone structure, and 5 to 30% of repeating units having a group represented by formula (I) Furthermore, it is a quaternary copolymer containing 0 to 30% of repeating units having an alicyclic hydrocarbon structure substituted with the polar group, or 0 to 20% of other repeating units. Alternatively, when the repeating unit represented by the general formula (I) has acid-decomposability, the repeating unit 0 to 40 having a partial structure containing an alicyclic hydrocarbon represented by the general formulas (pI) to (pV) %, A terpolymer containing 20 to 50% of the repeating unit containing the lactone structure, 5 to 30% of a repeating unit having a group represented by the general formula (I), and a fat substituted with the polar group It is a quaternary copolymer containing 0 to 30% of repeating units having a ring hydrocarbon structure or 0 to 20% of other repeating units.
As the most preferable resin, 20 to 50% of repeating units having an acid-decomposable group represented by ARA-1 to ARA-5, and 20 to 50 of repeating units having a lactone group represented by ARL-1 to ARL-6 %, The group represented by the general formula (I) does not exhibit acid-decomposability, that is, R _a2 is a hydrogen atom and contains 5 to 30% of repeating units having this group, or further carboxyl It is a quaternary copolymer containing 5 to 20% of a repeating unit containing a group or a structure represented by the general formula (F1) or an alicyclic hydrocarbon structure and not exhibiting acid decomposability.

(In the formula, Rxy ₁ represents a hydrogen atom or a methyl group, and Rxa ₁ and Rxb ₁ represent a methyl group or an ethyl group.)

  The resin (A) used in the present invention can be synthesized according to a conventional method (for example, radical polymerization). For example, as a general synthesis method, a monomer polymerization method in which a monomer species and an initiator are dissolved in a solvent and heating is performed, and a solution of the monomer species and the initiator is dropped into the heating solvent over 1 to 10 hours. The dropping polymerization method is added, and the dropping polymerization method is preferable. Examples of the reaction solvent include ethers such as tetrahydrofuran, 1,4-dioxane, diisopropyl ether, ketones such as methyl ethyl ketone and methyl isobutyl ketone, ester solvents such as ethyl acetate, amide solvents such as dimethylformamide and dimethylacetamide, Furthermore, the solvent which melt | dissolves the composition of this invention like the below-mentioned propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, and cyclohexanone is mentioned. More preferably, the polymerization is performed using the same solvent as the solvent used in the composition of the present invention. Thereby, generation | occurrence | production of the particle at the time of a preservation | save can be suppressed.

  The polymerization reaction is preferably performed in an inert gas atmosphere such as nitrogen or argon. As a polymerization initiator, a commercially available radical initiator (azo initiator, peroxide, etc.) is used to initiate the polymerization. As the radical initiator, an azo initiator is preferable, and an azo initiator having an ester group, a cyano group, or a carboxyl group is preferable. Preferred initiators include azobisisobutyronitrile, azobisdimethylvaleronitrile, dimethyl 2,2′-azobis (2-methylpropionate) and the like. If desired, an initiator is added or added in portions, and after completion of the reaction, it is put into a solvent and a desired polymer is recovered by a method such as powder or solid recovery. The concentration of the reaction is 5 to 50% by mass, preferably 10 to 30% by mass. The reaction temperature is usually 10 ° C to 150 ° C, preferably 30 ° C to 120 ° C, more preferably 60-100 ° C.

The weight average molecular weight of the resin (A) is preferably from 1,000 to 200,000, more preferably from 3,000 to 20,000, and most preferably from 5,000 to 15, as a polystyrene-converted value by the GPC method. 000. By setting the weight average molecular weight to 1,000 to 200,000, deterioration of heat resistance and dry etching resistance can be prevented, developability is deteriorated, and viscosity is increased, resulting in deterioration of film forming property. Can be prevented.
The molecular weight distribution is usually 1 to 5, preferably 1 to 3, more preferably 1 to 2. The smaller the molecular weight distribution, the better the resolution and pattern shape, the smoother the side walls of the pattern, and the better the roughness.

In the positive photosensitive composition of the present invention, the blending amount of all the resins according to the present invention in the whole composition is preferably 50 to 99.9% by mass, more preferably 60 to 99.0% in the total solid content. % By mass.
In the present invention, the resins may be used alone or in combination.

[2] A compound that generates an acid upon irradiation with actinic rays or radiation (hereinafter also referred to as “component (B)”).
The photosensitive composition of this invention contains the compound which generate | occur | produces an acid by irradiation of actinic light or a radiation. Examples of such photoacid generators include photoinitiators for photocationic polymerization, photoinitiators for photoradical polymerization, photodecolorants for dyes, photochromic agents, actinic rays used in microresists, etc. Known compounds that generate an acid upon irradiation with radiation and mixtures thereof can be appropriately selected and used.

  Examples thereof include diazonium salts, phosphonium salts, sulfonium salts, iodonium salts, imide sulfonates, oxime sulfonates, diazodisulfones, disulfones, and o-nitrobenzyl sulfonates.

  Further, a group that generates an acid upon irradiation with these actinic rays or radiation, or a compound in which a compound is introduced into the main chain or side chain of the polymer, for example, US Pat. No. 3,849,137, German Patent No. 3914407. JP, 63-26653, JP, 55-164824, JP, 62-69263, JP, 63-146038, JP, 63-163452, JP, 62-153853, The compounds described in JP-A 63-146029 can be used.

  Furthermore, compounds capable of generating an acid by light described in US Pat. No. 3,779,778, European Patent 126,712 and the like can also be used.

  Among the compounds that may be used in combination and decomposed by irradiation with actinic rays or radiation, preferred compounds include compounds represented by the following general formulas (ZI), (ZII), and (ZIII). it can.

In the above general formula (ZI), R ₂₀₁ , R ₂₀₂ and R ₂₀₃ each independently represents an organic group.
X ⁻ represents a non-nucleophilic anion, preferably sulfonate anion, carboxylate anion, bis (alkylsulfonyl) amide anion, tris (alkylsulfonyl) methide anion, BF ₄ ⁻ , PF ₆ ⁻ , SbF ₆ ^{− and the} like. Preferably, it is an organic anion containing a carbon atom.
Preferable organic anions include organic anions represented by the following formulas AN1 to AN4.

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 thereof, which may be substituted, is a single bond, —O—, —CO ₂ —, —S. _{-, - SO 3 -, -} SO 2 N (Rd 1) - could be mentioned linked group a linking group such as.

Rd ₁ represents a hydrogen atom or an alkyl group, and may form a ring structure with the bonded alkyl group or aryl group.
The organic group of Rc ₁ is more preferably an alkyl group substituted at the 1-position with a fluorine atom or a fluoroalkyl group, or a phenyl group substituted with a fluorine atom or a fluoroalkyl group. 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. When Rc ₁ has 5 or more carbon atoms, at least one carbon atom is preferably substituted with a hydrogen atom, and more preferably, the number of hydrogen atoms is larger than that of fluorine atoms. By not having a perfluoroalkyl group having 5 or more carbon atoms, ecotoxicity is reduced.
The most preferred embodiment of Rc ₁ is a group represented by the following general formula.

Rc ₆ is phenylene substituted with a perfluoroalkylene group having 4 or less carbon atoms, more preferably 2 to 4 carbon atoms, more preferably 2 to 3 carbon atoms, 3 to 5 fluorine atoms and / or 1 to 3 fluoroalkyl groups. It is a group.
Ax is a linking group (preferably a single bond, —O—, —CO ₂ —, —S—, —SO ₃ —, —SO ₂ N (Rd ₁ ) —). Rd ₁ represents a hydrogen atom or an alkyl group, and may combine with Rc ₇ to form a ring structure.
Rc ₇ : a hydrogen atom, a fluorine atom, an optionally substituted linear, branched, monocyclic or polycyclic alkyl group, or an optionally substituted aryl group. The optionally substituted alkyl group and aryl group preferably do not contain a fluorine atom as a substituent.
Rc ₃ , Rc ₄ and Rc ₅ represent an organic group.
Preferred examples of the organic group for Rc ₃ , Rc ₄ and Rc ₅ include the same organic groups as those for Rc ₁ .
Rc ₃ and Rc ₄ may be bonded to form a ring.
Examples of the group formed by combining 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 is increased, and the sensitivity is preferably improved.

The carbon number of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ is generally 1-30, preferably 1-20.
Two of R _{201 to} R ₂₀₃ may be bonded to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond, or a carbonyl group.
The two of the group formed by bonding of the R ₂₀₁ to R _203, there can be mentioned an alkylene group (e.g., butylene, pentylene).
Specific examples of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ include corresponding groups in the compounds (ZI-1), (ZI-2) and (ZI-3) described later.

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

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

The compound (ZI-1) is at least one of the aryl groups R ₂₀₁ to R ₂₀₃ in formula (ZI), arylsulfonium compound, i.e., a compound having arylsulfonium as a cation.
Arylsulfonium compound, all of R ₂₀₁ to R ₂₀₃ may be an aryl group or a part of R ₂₀₁ to R ₂₀₃ may be an aryl group with the remaining being an alkyl group.
Examples of the arylsulfonium compound include a triarylsulfonium compound, a diarylalkylsulfonium compound, and an aryldialkylsulfonium compound.
The aryl group of the arylsulfonium compound is preferably an aryl group such as a phenyl group or a naphthyl group, or a heteroaryl group such as an indole residue or a pyrrole residue, more preferably a phenyl group or an indole residue. When the arylsulfonium compound has two or more aryl groups, the two or more aryl groups may be the same or different.
The alkyl group that the arylsulfonium compound has as necessary is preferably a linear, branched or cyclic alkyl group having 1 to 15 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, sec. -Butyl group, t-butyl group, cyclopropyl group, cyclobutyl group, cyclohexyl group and the like can be mentioned.
Aryl group R ₂₀₁ to R _203, an alkyl group, an alkyl group (for example, 1 to 15 carbon atoms), an aryl group (e.g., carbon number 6 to 14), an alkoxy group (for example, 1 to 15 carbon atoms), a halogen atom, You may have a hydroxyl group and a phenylthio group as a substituent. Preferred substituents are linear, branched or cyclic alkyl groups having 1 to 12 carbon atoms, linear, branched or cyclic alkoxy groups having 1 to 12 carbon atoms, most preferably alkyl groups having 1 to 4 carbon atoms, It is a C1-C4 alkoxy group. The substituent may be substituted with any one of the three R _{201 to} R ₂₀₃ , or may be substituted with all three. When R _{201 to} R ₂₀₃ are an aryl group, the substituent is preferably substituted at the p-position of the aryl group.

Next, the compound (ZI-2) will be described.
Compound (ZI-2) is a compound in the case where R _{201 to} R ₂₀₃ in formula (ZI) each independently represents an organic group containing no aromatic ring. Here, the aromatic ring includes an aromatic ring containing a hetero atom.
The organic group having no aromatic ring as R ₂₀₁ to R ₂₀₃ generally has 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms.
R _{201 to} R ₂₀₃ are each independently preferably an alkyl group, a 2-oxoalkyl group, an alkoxycarbonylmethyl group, an allyl group, or a vinyl group, more preferably a linear, branched, or cyclic 2-oxoalkyl group, An alkoxycarbonylmethyl group, most preferably a linear, branched 2-oxoalkyl group.

The alkyl group as R ₂₀₁ to R ₂₀₃ may be linear, branched, or cyclic, preferably a linear or branched alkyl group (e.g., methyl group having 1 to 10 carbon atoms, an ethyl group, a propyl Group, butyl group, pentyl group) and cyclic alkyl groups having 3 to 10 carbon atoms (cyclopentyl group, cyclohexyl group, norbornyl group).
The 2-oxoalkyl group as R _{201 to} R ₂₀₃ may be linear, branched or cyclic, and preferably includes a group having> C═O at the 2-position of the above alkyl group. it can.
The alkoxy group in the alkoxycarbonylmethyl group as R ₂₀₁ to R _203, preferred examples include an alkyl group having 1 to 5 carbon atoms (methyl group, ethyl group, propyl group, butyl group, pentyl group).
R _{201 to} R ₂₀₃ may be further substituted with a halogen atom, an alkoxy group (for example, having 1 to 5 carbon atoms), a hydroxyl group, a cyano group, or a nitro group.
Two members out of R _{201 to} R ₂₀₃ may combine to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond, or a carbonyl group. The two of the group formed by bonding of the R ₂₀₁ to R _203, there can be mentioned an alkylene group (e.g., butylene, pentylene).

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

R _{1c to} R _5c each independently represents a hydrogen atom, an alkyl group, an alkoxy group, or a halogen atom.
R _6c and R _7c represent a hydrogen atom or an alkyl group.
Rx and Ry each independently represents an alkyl group, a 2-oxoalkyl group, an alkoxycarbonylmethyl group, an allyl group, or a vinyl group.
Any two or more of R _{1c to} R _5c , and R _x and R _y may be bonded to each other to form a ring structure, and this ring structure includes an oxygen atom, a sulfur atom, an ester bond, and an amide bond. May be included.

The alkyl group as R _{1c to} R _{5c may} be linear, branched or cyclic, for example, an alkyl group having 1 to 20 carbon atoms, preferably a linear or branched alkyl group having 1 to 12 carbon atoms. Group (for example, methyl group, ethyl group, linear or branched propyl group, linear or branched butyl group, linear or branched pentyl group), C3-C8 cyclic alkyl group (for example, cyclopentyl group, cyclohexyl group) ).
The alkoxy group as R _{1c to} R _{5c may} be linear, branched or cyclic, for example, an alkoxy group having 1 to 10 carbon atoms, preferably a linear or branched alkoxy group having 1 to 5 carbon atoms. (For example, methoxy group, ethoxy group, linear or branched propoxy group, linear or branched butoxy group, linear or branched pentoxy group), C3-C8 cyclic alkoxy group (for example, cyclopentyloxy group, cyclohexyloxy group) ).
Preferably either a straight chain of R _1c to R _5c, branched, cyclic alkyl group, or a linear, branched or cyclic alkoxy group, more preferably the sum of the carbon atoms of R _5c from R _1c 2 to 15 It is. Thereby, solvent solubility improves more and generation | occurrence | production of a particle is suppressed at the time of a preservation | save.

_Examples of the alkyl group as R _x and R _y include the same alkyl groups as R _{1c to} R _5c .
Examples of the 2-oxoalkyl group include a group having> C═O at the 2-position of the alkyl group as R _{1c to} R _5c .
Examples of the alkoxy group in the alkoxycarbonylmethyl group include the same alkoxy groups as R _{1c to} R _5c .
Examples of the group formed by combining R _x and R _y include a butylene group and a pentylene group.

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

In formula (ZII), (ZIII), R 204 ~R 207 each independently represents an alkyl group which may have an optionally substituted aryl group or a substituent.
Phenyl group and a naphthyl group are preferred as the aryl group of R ₂₀₄ to R _207, more preferably a phenyl group.
The alkyl group as R _{204 to} R ₂₀₇ may be linear, branched or cyclic, and is preferably a linear or branched alkyl group having 1 to 10 carbon atoms (for example, methyl group, ethyl group, propyl group). Group, butyl group, pentyl group) and cyclic alkyl groups having 3 to 10 carbon atoms (cyclopentyl group, cyclohexyl group, norbornyl group).
The R ₂₀₄ to R ₂₀₇ are substituents which may have, for example, an alkyl group (for example, 1 to 15 carbon atoms), an aryl group (e.g. having 6 to 15 carbon atoms), an alkoxy group (for example, 1 to 15 carbon atoms ), Halogen atoms, hydroxyl groups, phenylthio groups, and the like.
X ⁻ represents a non-nucleophilic anion, and examples thereof include the same non-nucleophilic anion as X ^{− in} formula (ZI).

  Of the compounds that decompose upon irradiation with actinic rays or radiation that may be used in combination, preferred compounds further include compounds represented by the following general formulas (ZIV), (ZV), and (ZVI). be able to.

In general formulas (ZIV) to (ZVI), Ar ₃ and Ar ₄ each independently represent a substituted or unsubstituted aryl group.
R ₂₀₆ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group.
_R207 and _{R208 each represents a} substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or an electron-withdrawing group. R ₂₀₇ is preferably a substituted or unsubstituted aryl group.
R ₂₀₈ is preferably an electron-withdrawing group, more preferably a cyano group or a fluoroalkyl group.
A represents a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkenylene group, or a substituted or unsubstituted arylene group.

Of the compounds that decompose upon irradiation with actinic rays or radiation to generate an acid, more preferred are compounds represented by general formulas (ZI) to (ZIII), and even more preferred are compounds represented by (ZI). Most preferred are compounds represented by (ZI-1) to (ZI-3).
Furthermore, 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.

  That is, the most preferable embodiment of the component (B) is a compound in which X- is an anion selected from AN1, AN3 and AN4 in the structure of the general formula (ZI).

  Among the compounds that decompose upon irradiation with actinic rays or radiation to generate an acid, examples of particularly preferable compounds are listed below.

An acid generator can be used individually by 1 type or in combination of 2 or more types. When two or more types are used in combination, it is preferable to combine two types of compounds that generate two types of organic acids that differ in the total number of atoms excluding hydrogen atoms by two or more.
The content of the acid generator in the composition is preferably 0.1 to 20% by mass, more preferably 0.5 to 10% by mass, and still more preferably 1 to 7%, based on the total solid content of the photosensitive composition. % By mass.

[3] Dissolution Control Compound (C) A dissolution control compound having a molecular weight of 3000 or less (hereinafter referred to as “component (C)” or “dissolution control compound” having at least one selected from alkali-soluble groups, hydrophilic groups, and acid-decomposable groups. May also be added.

(C) The dissolution control compound includes a carboxyl group, a sulfonylimide group, a compound having an alkali-soluble group such as a hydroxyl group substituted at the α-position with a fluoroalkyl group, a hydroxyl group, a lactone group, a cyano group, an amide group, or a pyrrolidone. A compound having a hydrophilic group such as a group or a sulfonamide group, or a compound containing a group that decomposes by the action of an acid to release an alkali-soluble group or a hydrophilic group is preferable. The group capable of decomposing by the action of an acid to release an alkali-soluble group or a hydrophilic group is preferably a group in which a carboxyl group or a hydroxyl group is protected with an acid-decomposable group. In order not to lower the permeability of 220 nm or less as the dissolution control compound, it is preferable to use a compound that does not contain an aromatic ring or to use a compound having an aromatic ring in an amount of 20% by mass or less based on the solid content of the composition. .
Preferred dissolution control compounds include carboxylic acid compounds having an alicyclic hydrocarbon structure such as adamantane (di) carboxylic acid, norbornane carboxylic acid, and cholic acid, or compounds in which the carboxylic acid is protected with an acid-decomposable group, and polyols such as saccharides. Or a compound having its hydroxyl group protected with an acid-decomposable group is preferred.

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

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

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

[4] Basic compound (component D)
The positive photosensitive composition of the present invention contains (D) a basic compound in order to reduce the change in performance over time from exposure to heating or to control the diffusibility of the acid generated by exposure in the film. Is preferred.

  Examples of basic compounds include nitrogen-containing basic compounds and onium salt compounds. Preferable nitrogen-containing basic compound structures include compounds having partial structures represented by the following formulas (A) to (E).

Here, R ²⁵⁰ , R ²⁵¹ and R ²⁵² are each independently 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 (preferably carbon). Where R ²⁵⁰ and R ²⁵¹ may combine with each other to form a ring. These may have a substituent. Examples of the alkyl group and cycloalkyl group having a substituent include an aminoalkyl group having 1 to 20 carbon atoms, an aminocycloalkyl group having 3 to 20 carbon atoms, and 1 to 1 carbon atoms. A 20 hydroxyalkyl group or a C 3-20 hydroxycycloalkyl group is preferred.
These may contain an oxygen atom, a sulfur atom, or a nitrogen atom in the alkyl chain.

In the formula, R ²⁵³ , R ²⁵⁴ , R ²⁵⁵ and R ²⁵⁶ each independently represents an alkyl group (preferably having 1 to 6 carbon atoms) or a cycloalkyl group (preferably having 3 to 6 carbon atoms).

  Preferable compounds include guanidine, aminopyrrolidine, pyrazole, pyrazoline, piperazine, aminomorpholine, aminoalkylmorpholine, and piperidine, and may have a substituent. More preferable compounds include compounds having an imidazole structure, a diazabicyclo structure, 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, a hydroxyl group and / or Or the aniline derivative which has an ether bond etc. can be mentioned.

  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] non-5-ene, and 1,8-diazabicyclo [5,4,0. ] Undec-7-ene. Examples of the compound having an onium hydroxide structure include triarylsulfonium hydroxide, phenacylsulfonium hydroxide, sulfonium hydroxide having a 2-oxoalkyl group, specifically triphenylsulfonium hydroxide, tris (t-butylphenyl) sulfonium. Examples thereof include hydroxide, bis (t-butylphenyl) iodonium hydroxide, phenacylthiophenium hydroxide, and 2-oxopropylthiophenium hydroxide. The compound having an onium carboxylate structure is a compound having an onium hydroxide structure in which the anion moiety is converted to a carboxylate, and examples thereof include acetate, adamantane-1-carboxylate, and perfluoroalkylcarboxylate. Examples of the compound having a trialkylamine structure include tri (n-butyl) amine and tri (n-octyl) amine. Examples of aniline compounds include 2,6-diisopropylaniline and N, N-dimethylaniline. Examples of the alkylamine derivative having a hydroxyl group and / or an ether bond include ethanolamine, diethanolamine, triethanolamine, and tris (methoxyethoxyethyl) amine. Examples of aniline derivatives having a hydroxyl group and / or an ether bond include N, N-bis (hydroxyethyl) aniline.

  These basic compounds are used alone or in combination of two or more. 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%. In order to obtain a sufficient addition effect, 0.001% by mass or more is preferable, and 10% by mass or less is preferable in terms of sensitivity and developability of the non-exposed area.

[5] Fluorine and / or silicon surfactant (E component)
The positive photosensitive composition of the present invention further includes a fluorine-based and / or silicon-based surfactant (fluorine-based surfactant and silicon-based surfactant, a surfactant containing both fluorine and silicon atoms). It is preferable to contain any one of these or 2 or more types.

  When the positive photosensitive composition of the present invention contains fluorine and / or a silicon-based surfactant, adhesion and development with good sensitivity and resolution when using an exposure light source of 250 nm or less, particularly 220 nm or less. A pattern with few defects can be provided.

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

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

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

  As the polymer having a fluoroaliphatic group, a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate and / or (poly (oxyalkylene)) methacrylate is preferable and distributed irregularly. It may be block copolymerized. Examples of the poly (oxyalkylene) group include a poly (oxyethylene) group, a poly (oxypropylene) group, a poly (oxybutylene) group, and the like, and a poly (oxyethylene, oxypropylene, and oxyethylene group). A unit having different chain lengths in the same chain length, such as a block link) or poly (block link of oxyethylene and oxypropylene) may be used. Furthermore, a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate (or methacrylate) is not only a binary copolymer but also a monomer having two or more different fluoroaliphatic groups, Further, it may be a ternary or higher copolymer obtained by simultaneously copolymerizing two or more different (poly (oxyalkylene)) acrylates (or methacrylates).

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

  The amount of 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). %.

[6] (F) Organic Solvent The positive photosensitive composition of the present invention is used by dissolving the above components in a predetermined organic solvent.

  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, etc.

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. As a result, the solubility of the material is increased, and not only the generation of particles over time can be suppressed, but also a good pattern profile can be obtained. Preferable functional groups contained in the solvent include ester groups, lactone groups, hydroxyl groups, ketone groups, and carbonate groups. As the mixed solvent having different functional groups, the following mixed solvents (S1) to (S5) are preferable (S1) a mixed solvent in which a solvent containing a hydroxyl group and a solvent not containing a hydroxyl group are mixed,
(S2) Mixed solvent in which a solvent having an ester structure and a solvent having a ketone structure are mixed (S3) A mixed solvent in which a solvent having an ester structure and a solvent having a lactone structure are mixed (S4) A solvent having an ester structure and a lactone Mixed solvent in which solvent having structure and solvent containing hydroxyl group are mixed (S5) Mixed solvent in which solvent having ester structure, solvent having carbonate structure and solvent containing hydroxyl group are mixed
Thereby, the generation of particles during storage of the photosensitive composition can be reduced, and the generation of defects during 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. Particularly preferred are propylene glycol monomethyl ether and ethyl lactate.

  Examples of the solvent not containing a hydroxyl group include propylene glycol monomethyl ether acetate, ethyl ethoxypropionate, 2-heptanone, γ-butyrolactone, cyclohexanone, butyl acetate, N-methylpyrrolidone, N, N-dimethylacetamide, dimethyl sulfoxide and the like. Among these, propylene glycol monomethyl ether acetate, ethyl ethoxypropionate, 2-heptanone, γ-butyrolactone, cyclohexanone, and butyl acetate are particularly preferred, and propylene glycol monomethyl ether acetate, ethyl ethoxypropionate. 2-heptanone and cyclohexanone are most preferred.

Examples of the solvent having a ketone structure include cyclohexanone and 2-heptanone, and cyclohexanone is preferable.
Examples of the solvent having an ester structure include propylene glycol monomethyl ether acetate, ethyl ethoxypropionate, and butyl acetate, and propylene glycol monomethyl ether acetate is preferable.
Examples of the solvent having a lactone structure include γ-butyrolactone.
Examples of the solvent having a carbonate structure include propylene carbonate and ethylene carbonate, with propylene carbonate being preferred.
The mixing ratio (mass) of the solvent containing a hydroxyl group and the solvent not containing a hydroxyl group is 1/99 to 99/1, preferably 10/90 to 90/10, more preferably 20/80 to 60/40. . A mixed solvent containing 50% by mass or more of a solvent not containing a hydroxyl group is particularly preferred from the viewpoint 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 from the viewpoint 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 from the viewpoint of stability over time.
When mixing a solvent having an ester structure, a solvent having a lactone structure, and a solvent containing a hydroxyl group, the solvent having an ester structure is 30 to 80% by mass, the solvent having a lactone structure is 1 to 20% by mass, and the hydroxyl group is contained. It is preferable to contain 10-60 mass% of solvent to do.
When mixing a solvent having an ester structure, a solvent having a carbonate structure, and a solvent containing a hydroxyl group, the solvent having an ester structure is 30 to 80% by mass, the solvent having a carbonate structure is 1 to 20% by mass, and the hydroxyl group is contained. It is preferable to contain 10-60 mass% of solvent to do.
A preferable embodiment of these solvents is a solvent containing an alkylene glycol monoalkyl ether carboxylate (preferably propylene glycol monomethyl ether acetate), more preferably a mixed solvent of an alkylene glycol monoalkyl ether carboxylate and another solvent, The other solvent is at least one selected from a functional group selected from a hydroxyl group, a ketone group, a lactone group, an ester group, an ether group and a carbonate group, or a solvent having a plurality of these functional groups. The most preferred mixed solvent is a mixed solvent of propylene glycol monomethyl ether acetate and at least one selected from ethyl lactate, γ-butyrolactone, propylene glycol monomethyl ether, butyl acetate, and cyclohexanone.
The development defect performance can be improved by selecting an optimum solvent.

[6] Other Additives The positive photosensitive composition of the present invention may further contain a dye, a plasticizer, a surfactant other than the above component (E), a photosensitizer and the like as necessary. it can.
In the present invention, a surfactant other than the above (E) fluorine-based and / or silicon-based surfactant may be added. Specifically, nonionic interfaces such as polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, polyoxyethylene / polyoxypropylene block copolymers, sorbitan aliphatic esters, polyoxyethylene sorbitan aliphatic esters, etc. Mention may be made of activators.

  These surfactants may be added alone or in some combination.

[7] Pattern formation method
The positive photosensitive composition of the present invention is used by dissolving the above components in a predetermined organic solvent, preferably the mixed solvent, filtering the solution, and applying the solution on a predetermined support as follows. The filter used for filter filtration is preferably made of polytetrafluoroethylene, polyethylene, or nylon of 0.1 microns or less, more preferably 0.05 microns or less, and still more preferably 0.03 microns or less.

For example, a positive photosensitive composition is coated on a substrate (eg, silicon / silicon dioxide coating) used in the manufacture of precision integrated circuit elements by a suitable coating method such as a spinner or coater, dried, and photosensitive. A film is formed. An antireflection film may be applied prior to the application of the photosensitive film.
The photosensitive film is irradiated with actinic rays or radiation through a predetermined mask, preferably baked (heated), developed and rinsed. Thereby, a good pattern can be obtained.
Exposure (immersion exposure) may be performed by filling a liquid (immersion medium) having a higher refractive index than air between the photosensitive film and the lens during irradiation with actinic rays or radiation. Thereby, resolution can be improved. As the immersion medium to be used, any liquid can be used as long as it has a higher refractive index than air, but pure water is preferred. Further, an overcoat layer may be further provided on the photosensitive film so that the immersion medium and the photosensitive film do not come into direct contact with each other during the immersion exposure. Thereby, elution of the composition from the photosensitive film to the immersion medium is suppressed, and development defects are reduced.

Examples of the actinic ray or radiation include infrared light, visible light, ultraviolet light, far ultraviolet light, X-ray, electron beam, etc., but preferably far ultraviolet light having a wavelength of 250 nm or less, more preferably 220 nm or less. Specifically, KrF excimer laser (248 nm), ArF excimer laser (193 nm), F ₂ excimer laser (157 nm), X-ray, electron beam, etc. ArF excimer laser, F ₂ excimer laser, EUV (13 nm) An electron beam is preferred.

In the development step, an alkaline developer is used as follows. Examples of the alkaline developer include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia, primary amines such as ethylamine and n-propylamine, diethylamine, di- Secondary amines such as n-butylamine, tertiary amines such as triethylamine and methyldiethylamine, alcohol amines such as dimethylethanolamine and triethanolamine, quaternary ammonium such as tetramethylammonium hydroxide and tetraethylammonium hydroxide Alkaline aqueous solutions such as salts, cyclic amines such as pyrrole and pihelidine can be used.
Furthermore, alcohols and surfactants can be added in appropriate amounts to the alkaline developer.
The alkali concentration of the alkali developer is usually from 0.1 to 20% by mass.
The pH of the alkali developer is usually from 10.0 to 15.0.

  The following examples illustrate the invention and are not intended to limit its scope.

<Synthesis Example 1>
Synthesis of Compound II-8 (Rx = Me);
To methylmagnesium bromide (184 ml, 33% diethyl ether solution) was added dropwise 100 ml of a tetrahydrofuran solution containing 25.0 g of methyl 4-hydroxycyclohexanecarboxylate. After reacting at room temperature for 2 hours and at 50 ° C. for 2 hours, 500 ml of 1M aqueous hydrochloric acid solution was added to the reaction solution. This was extracted with 500 ml of ethyl acetate. The organic phase was washed with saturated sodium bicarbonate water and distilled water, dried and concentrated to obtain a crude product. This was purified by silica gel column chromatography to obtain 22.7 g of 4- (2-hydroxy-2-propyl) cyclohexanol.
The obtained 4- (2-hydroxy-2-propyl) cyclohexanol (22.7 g) and triethylamine (17.4 g) were dissolved in 150 ml of tetrahydrofuran, and 21.1 g of methacryloyl chloride was slowly added under ice cooling. The mixture was warmed to room temperature and reacted for 4 hours. 500 ml of 1M aqueous hydrochloric acid solution was added to the reaction solution, and this was extracted with 500 ml of ethyl acetate. The organic phase was washed with saturated sodium bicarbonate water and distilled water, dried and concentrated to obtain a crude product. This was purified by silica gel column chromatography to obtain 15.4 g of Compound II-8 (Rx = Me).
1H-NMR: 1.19 (s, 3H × 2), 1.34 (m, 2H), 1.52 (m, 2H) 1.69 (m, 2H), 1.95 (m, 3H), 2.02 (m, 2H), 5.10 (m, 1H), 5.54 (m, 1H), 6.11 (m, 1H)

<Synthesis Example 2>
Synthesis of Compound II-39 (Rx = Me);
Compound II-39 was synthesized in the same manner as in Example 1, except that methylmagnesium bromide was replaced with ethylmagnesium bromide.

<Synthesis Example 3>
Synthesis of Compound II-16 (Rx = Me) Methyl 1,4-cyclohexyldicarboxylate was reacted with methylmagnesium bromide to obtain 1,4-bis (2-hydroxy-2-propyl) cyclohexane. Methacrylate formation was performed in the same manner as in Example 1 to synthesize Compound II-16 (Rx = Me).

<Synthesis Example 4>
Synthesis of Resin (RA-8) In a nitrogen stream, 5.8 g of propylene glycol monomethyl ether acetate and 3.9 g of propylene glycol monomethyl ether were placed in a three-necked flask and heated to 80 ° C. 5.4 g of compound I I- 8 (Rx = Me), 4.1 g of γ-butyrolactone methacrylate, 8.4 g of 2- (1-adamantyl) isopropyl-2-methacrylate, initiator V-601 (manufactured by Wako Pure Chemical Industries, Ltd.) ) Was added dropwise over 6 hours to 8 mol% of the monomer dissolved in 36 g of propylene glycol monomethyl ether acetate and 24 g of propylene glycol monomethyl ether. After completion of dropping, the reaction was further carried out at 80 ° C. for 2 hours. The reaction solution was allowed to cool and then poured into 700 ml of hexane / 300 ml of ethyl acetate, and the precipitated powder was collected by filtration and dried to obtain 12 g of Resin (RA-8). The weight average molecular weight of the obtained resin was 8800 in terms of standard polystyrene, and the dispersity (Mw / Mn) was 1.68.

<Preparation of photosensitive composition>
The components shown in Table 1 below were dissolved in a solvent to prepare a solution having a solid content concentration of 8% by mass, and this was filtered through a 0.03 μm polyethylene filter to prepare a positive photosensitive composition. Evaluation was performed by the following method, and the results are also shown in Table 1.
Examples Ar7, Ar14, and Ar19 should be read as “reference examples”.

<Evaluation>
An anti-reflective coating DUV-42 manufactured by Brewer Science Co., Ltd. was uniformly applied to 600 angstroms on a silicon substrate subjected to hexamethyldisilazane treatment with a spin coater, dried on a hot plate at 100 ° C. for 90 seconds, and then at 190 ° C. Heat drying was performed for 240 seconds. Thereafter, each positive photosensitive composition was applied by a spin coater and dried at 110 ° C. for 90 seconds to form a 180 nm photosensitive film. The photosensitive film was exposed with an ArF excimer laser stepper (SML NA = 0.75, 2/3 ring zone) through a mask, and heated on a hot plate at 120 ° C. for 90 seconds immediately after the exposure. Further, the resist film was developed with an aqueous 2.38 mass% tetramethylammonium hydroxide solution at 23 ° C. for 60 seconds, rinsed with pure water for 30 seconds, and then dried to obtain a line pattern.

Pattern collapse evaluation method:
When the line width of the line pattern formed by increasing the exposure amount from the optimal exposure amount is reduced to the optimal exposure amount, the exposure amount for reproducing the 80 nm line and space 1: 1 mask pattern Defined with line width that resolves without falling down. The smaller the value, the finer pattern is resolved without falling, and the pattern collapse is less likely to occur and the resolution is higher.

Line edge roughness evaluation method:
Using a length-measuring scanning electron microscope (SEM), observe a 80 nm line-and-space 1: 1 pattern and measure the distance from the reference line where the edge of the line pattern should be 5 μm long. 20 points were measured by SEM (Hitachi, Ltd. S-8840), the standard deviation was obtained, and 3σ was calculated. A smaller value indicates better performance.

[Basic compounds]
TPSA: Triphenylsulfonium acetate
DIA: 2,6-diisopropylaniline
DCMA: Dicyclohexylmethylamine
TPA: Tripentylamine
HAP: Hydroxyantipyrine
TBAH: Tetrabutylammonium hydroxide
TMEA: Tris (methoxyethoxyethyl) amine
PEA: N-phenyldiethanolamine HEP: N-hydroxyethylpiperidine

[Surfactant]
W-1: MegaFuck F176 (Dainippon Ink Chemical Co., Ltd.) (Fluorine)
W-2: Megafuck R08 (Dainippon Ink Chemical Co., Ltd.) (fluorine and silicon)
W-3: Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) (silicon-based)
W-4: Troisol S-366 (manufactured by Troy Chemical Co., Ltd.)

〔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

Immersion exposure <Preparation of photosensitive composition>
The components Ar1 to Ar17 in Table 1 and the components of Comparative 1 were dissolved in a solvent to prepare a solution having a solid content concentration of 6% by mass, and this was filtered through a 0.03 μm polyethylene filter to prepare a positive photosensitive composition. The following method was used for evaluation.

<Resolution evaluation>
An organic antireflection film ARC29A (Nissan Chemical Co., Ltd.) was applied onto a silicon wafer and baked at 205 ° C. for 60 seconds to form a 78 nm antireflection film. The photosensitive composition prepared thereon was applied and baked at 115 ° C. for 60 seconds to form a 150 nm photosensitive film.
The wafer thus obtained was subjected to two-beam interference exposure (wet exposure) using pure water as the immersion liquid. In the two-beam interference exposure (wet), a laser, a diaphragm, a shutter, three reflecting mirrors, and a condenser lens were used, and the wafer was exposed through a prism and an immersion liquid. The laser wavelength was 193 nm, and a prism that formed a 65 nm line and space pattern was used. Immediately after the exposure, the film was heated at 115 ° C. for 90 seconds, developed with an aqueous tetramethylammonium hydroxide solution (2.38 mass%) for 60 seconds, rinsed with pure water, and then spin-dried to obtain a pattern obtained by scanning electron microscopy. (Hitachi S-9260) was used for observation. When the compositions of Examples Ar1 to Ar19 were used, a 65 nm line and space pattern was resolved without causing pattern collapse. When the compositions of Comparative Examples 1 and 2 were used, a 65 nm line and space pattern was resolved, but pattern collapse was observed in some patterns.
It is clear that the composition of the present application has a good image forming ability even in an exposure method through an immersion liquid.

Claims (6)

(A) a resin containing a repeating unit represented by formula (I) and a repeating unit having a lactone structure, which decomposes by the action of an acid and increases the solubility in an alkali developer, and (B) A positive photosensitive composition containing a compound that generates an acid upon irradiation with actinic rays or radiation.

In general formula (I):
Rx represents a hydrogen atom, an alkyl group or a cyano group.
Ra ₁ and Ra ₂ each independently represent a hydrogen atom or an organic group.
Ra ₃ and Ra ₄ each independently represents an unsubstituted alkyl group, cycloalkyl group, aryl group or aralkyl group .
Ra ₃ and Ra ₄ may be bonded to each other to form a ring structure.
X represents a single bond or an alkylene group.
Y represents an atomic group necessary to form a monocyclic hydrocarbon group together with the carbon atom C _1.
n represents 1 or 2.   The positive photosensitive composition according to claim 1, wherein the resin (A) further contains a repeating unit having an acid-decomposable group having an alicyclic hydrocarbon structure.   The positive photosensitive composition according to claim 1, wherein the resin (A) contains a repeating unit having a partial structure represented by the following general formula (VIIa).

  In general formula (VIIa), R _2c ~ R _4c Each independently represents a hydrogen atom, a hydroxyl group or a cyano group. However, R _2c ~ R _4c At least one of these represents a hydroxyl group or a cyano group. A photosensitive film formed using the positive photosensitive composition according to claim 1. A pattern forming method comprising exposing and developing the photosensitive film according to claim 4 . The pattern forming method according to claim 5, wherein the photosensitive film is exposed through an immersion medium.