JP2010102336A - Pattern forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an excellent pattern forming method employed to form a minute pattern in the manufacture of a semiconductor and suppress both of line width roughness and pattern collapse, and to provide a photosensitive composition used in this method. <P>SOLUTION: This pattern forming method includes a process for forming a resist film by using the photosensitive composition having a specific repeating unit having at least a polar group and containing a resin (A) for increasing solubility in an alkaline developer by action of acid, a process for exposing the resist film, a heating process (PEB process), a developing process, and a post-baking process. In the post-baking process, post-baking is performed by setting a heating temperature to a temperature not lower than [a glass-transition temperature (Tg) of the resin (A)-20°C]. The photosensitive composition used in this pattern forming method is also provided. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

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

  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, the main component is a resin having a basic skeleton of poly (hydroxystyrene) having a small absorption in the 248 nm region. 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, an ArF excimer laser (193 nm) is used as an exposure light source, the compound having an aromatic group exhibits a large absorption in the 193 nm region. It wasn't.
For this reason, an ArF excimer laser resist containing a resin having an alicyclic hydrocarbon structure has been developed. For example, Patent Documents 1 and 2 describe a composition containing a resin having a repeating unit having an acid-decomposable group having a polycyclic structure and a non-acid-decomposable repeating unit. Patent Document 3 discloses a resist composition containing a specific sulfonic acid generator.
These resins are chemically amplified resists having an acid-labile protecting group that is dissociated by an acid, but line width roughness (LWR) is required as the resist pattern needs to be further miniaturized. Improvement has become an urgent need. For example, in a line and space pattern with a pitch of 100 nm, when the line pattern is 50 nm, the LWR is required to be 5 nm or less. That is, as the miniaturization progresses, it is necessary to control the LWR to 10% or less with respect to the line width.

  However, the conventional resist composition still has insufficient points, and further improvement is desired from the viewpoint of achieving both trade-off relationship between LWR suppression and pattern collapse suppression.

JP 2003-167347 A Japanese Patent Laid-Open No. 2003-223001 JP 2005-173549 A

  The present invention has been made in view of the above-described background, and the object thereof is to form an excellent L pattern forming method that is used for forming a fine pattern in semiconductor manufacturing, and that achieves both LWR suppression and pattern collapse suppression, and a photosensitive material used therefor. It is to provide a sex composition.

As a result of intensive studies to solve the above problems, the present inventors have determined the heating temperature of the post-baking step when forming a pattern using a photosensitive composition containing a resin having a repeating unit having a specific structure [ It was found that LWR and pattern collapse were suppressed and an excellent pattern was obtained by heating at a temperature equal to or higher than the glass transition temperature (Tg) -20 ° C.] of the resin.
That is, the above object is achieved by the following configuration.

  (1) A resist film is formed using a photosensitive composition containing a resin (A) having at least a repeating unit represented by the following general formula (1) and having increased solubility in an alkali developer by the action of an acid. A step of forming, a step of exposing the resist film, a heating step (PEB step), a developing step, and a post-baking step, and the heating temperature in the post-baking step is [the glass transition temperature (Tg) of the resin (A) − A pattern forming method comprising a step of post-baking at a temperature of 20 ° C. or higher.

In general formula (1),
Xa ₁ represents a hydrogen atom, a methyl group or a group represented by —CH ₂ —R ₉ . R ₉ represents a hydroxyl group or a monovalent organic group.
Rx _{1 to} Rx ₃ each independently represents an alkyl group (straight or branched) or a cycloalkyl group (monocyclic or polycyclic). Two of Rx _{1 to} Rx ₃ may combine to form a cycloalkyl group (monocyclic or polycyclic).
Incidentally, the group represented by -C in the general formula _{(1) (Rx 1) (} Rx 2) (Rx 3) has at least one - as a substituent having an (L) group represented by _n1 -P.
L represents a divalent linking group. n ₁ is 0 or 1. P represents a polar group.

  (2) The pattern forming method as described in (1) above, wherein the resin (A) is a resin having a repeating unit represented by the following general formula (2).

In general formula (2),
A represents an ester bond or an amide bond.
R ₀ represents an alkylene group, a cycloalkylene group or a divalent linking group obtained by combining them, and when there are a plurality of R ₀ groups, they may be the same or different.
Z represents an ether bond, an ester bond, an amide bond, a urethane bond or a combination thereof, and when there are a plurality thereof, they may be the same or different.
R ₈ represents a monovalent organic group having a lactone structure.
n ₂ has the general formula is a repeating number of the structure represented by _-R 0 -Z- in the repeating a unit represented by (2), represents an integer of 1 to 5.
R ₇ represents a hydrogen atom, a halogen atom or an alkyl group.

  (3) The pattern forming method as described in (1) or (2) above, wherein the photosensitive composition further contains a compound capable of generating an acid upon irradiation with actinic rays or radiation.

(4) Resin (A) contains the repeating unit represented by General formula (1) whose P is a hydroxyl group, The photosensitive composition in any one of said (1)-(3) characterized by the above-mentioned. object.
(5) patterning according to any one of the resin (A), the characterized by containing repeating units n ₂ is represented by the general formula (2) is 1 (1) to (4) Method.
(6) The pattern forming method as described in any one of (1) to (5) above, wherein the resin (A) further contains a repeating unit represented by the general formula (3).

In general formula (3), R ₅ represents a hydrocarbon group having at least one cyclic structure and having neither a hydroxyl group nor a cyano group.
Ra represents a hydrogen atom, an alkyl group, or a —CH ₂ —O—Ra ₂ group. In the formula, Ra ₂ represents a hydrogen atom, an alkyl group or an acyl group.

  According to the present invention, there are provided a pattern forming method and a photosensitive composition used in the pattern forming method, which can achieve both LWR and suppression of pattern collapse.

The present invention will be described below.
In addition, in the description of a group (atomic group) in this specification, the description which does not describe substitution and unsubstituted includes what has a substituent with what does not have 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).

Resin (A) having at least a repeating unit represented by the general formula (1) and having increased solubility in an alkaline developer by the action of an acid
The photosensitive composition used in the method of the present invention contains a resin (A) having at least a repeating unit represented by the general formula (1) and increasing the solubility in an alkali developer by the action of an acid.

In general formula (1),
Xa ₁ represents a hydrogen atom, a methyl group or a group represented by —CH ₂ —R ₉ . R ₉ represents a hydroxyl group or a monovalent organic group. Rx _{1 to} Rx ₃ each independently represents an alkyl group (straight or branched) or a cycloalkyl group (monocyclic or polycyclic). Any two of Rx _{1 to} Rx ₃ may combine to form a cycloalkyl group (monocyclic or polycyclic).
Incidentally, the group represented by -C in the general formula _{(1) (Rx 1) (} Rx 2) (Rx 3) has at least one - as a substituent having an (L) group represented by _n1 -P.
L represents a divalent linking group. n ₁ is 0 or 1. P represents a polar group.

In general formula (1),
Xa ₁ represents a hydrogen atom, a methyl group or a group represented by —CH ₂ —R ₉ . R ₉ represents a hydroxyl group or a monovalent organic group (for example, an alkyl group having 5 or less carbon atoms or an acyl group, preferably an alkyl group having 3 or less carbon atoms, and more preferably a methyl group). And a hydroxyl group is preferred. Methyl group of xa ₁ is a halogen atom (preferably fluorine atom) may be substituted by like. Xa ₁ is preferably a hydrogen atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group.
The alkyl group of Rx _{1 to} Rx ₃ is preferably an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, or a t-butyl group.
As the cycloalkyl group represented by Rx _{1 to} Rx _3, a cycloalkyl group having ₃ to 15 carbon atoms is preferable. For example, a monocyclic cycloalkyl group such as a cyclopentyl group and a cyclohexyl group, a norbornyl group, a tetracyclodecanyl group, a tetra Examples thereof include polycyclic cycloalkyl groups such as a cyclododecanyl group and an adamantyl group.
As the cycloalkyl group formed by combining any two of Rx _{1 to} Rx ₃ , a cycloalkyl group having 3 to 15 carbon atoms is preferable, for example, a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group, Examples thereof include polycyclic cycloalkyl groups such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, and an adamantyl group. A state in which Rx ₁ is a methyl group or an ethyl group, Rx ₂ and Rx ₃ are bonded to form the above-described cycloalkyl group, and a-(L) _n1 -P group is bonded to the cycloalkyl group. preferable.
Examples of the polar group of P include an amide group such as a hydroxyl group, a cyano group, an amino group, an acid amide group (—CONH ₂ ) and an alkylamide group, and a sulfonamide group. Preferred polar groups include A hydroxyl group, a cyano group, and an amide group are preferable, and a hydroxyl group is more preferable.
Examples of the divalent linking group for L include a linear or branched alkylene group and a cycloalkylene group, and a branched alkylene group is preferred. Further, the number of atoms of the divalent linking group as L is preferably 20 or less, and more preferably 15 or less.
The group represented by — (L) _n1 —P is, for example, a linear or branched group having a hydroxyl group, a cyano group, an amino group, an alkylamide group, an acid amide group, or a sulfonamide group, when n1 = 1. Examples include an alkyl group (preferably having 1 to 10 carbon atoms) and a cycloalkyl group (preferably having 3 to 15 carbon atoms), preferably an alkyl group having a hydroxyl group or a cyano group (preferably having 1 to 5 carbon atoms), and more. Preferably, it is an alkyl group having a hydroxyl group (preferably having 1 to 5 carbon atoms).
Furthermore, an alkyl group (preferably having 3 to 5 carbon atoms) in which a tertiary carbon atom is substituted with a hydroxyl group or a cyano group is preferable, and —C (CH ₃ ) ₂ OH and —C (CH ₃ ) ₂ CN are more preferable.
Each of the above groups may have a substituent. Examples of the substituent include an alkyl group (1 to 4 carbon atoms), a halogen atom, a hydroxyl group, an alkoxy group (1 to 4 carbon atoms), a carboxyl group, An alkoxycarbonyl group (C2-C6) etc. are mentioned, C8 or less is preferable.
P is preferably a hydroxyl group, n1 is 1, and L is preferably a linear or branched alkylene group (preferably having 1 to 5 carbon atoms). L is preferably a branched alkylene group having a tertiary carbon atom substituted with a hydroxyl group (preferably having 3 to 5 carbon atoms), more preferably a branched alkylene group having 3 carbon atoms having a tertiary carbon atom substituted with a hydroxyl group. .
The group represented by —C (Rx ₁ ) (Rx ₂ ) (Rx ₃ ) in the general formula (1) preferably has 1 to 3 groups represented by — (L) _n1 —P. Or it is more preferable to have two, and it is most preferable to have one.
A monomer corresponding to the repeating unit of the general formula (1) can be synthesized by, for example, a method described in JP-A-2006-16379.

As for the content rate of the repeating unit represented by General formula (1), 5-50 mol% is preferable with respect to all the repeating units in resin (A), More preferably, it is 10-30 mol%.
Moreover, you may have 2 or more types of repeating units represented by General formula (1). “Two or more types” refers to one type of repeating unit represented by the general formula (1) and one or more types of repeating units represented by the general formula (1) that are not the same repeating unit as the repeating unit. It means to contain. The molar ratio of the repeating units represented by the two general formulas (1) at that time is preferably 90/10 to 10/90, more preferably 80/20 to 20/80.

Although the preferable specific example is shown below about the repeating unit represented by General formula (1), it is not limited to these.
In the following structural formulas, Q represents a group represented by-(L) _n1 -P. (L, P, and n ₁ are synonymous with those in the general formula (1).)
Rx represents a hydrogen atom, CH ₃ , CF ₃ , or CH ₂ OH.
Rxa and Rxb each independently represents an alkyl group having 1 to 4 carbon atoms.
When there are a plurality of each, they may be the same or different.
p represents an integer of 1 to 15.

  The repeating unit represented by the general formula (1) is preferably a repeating unit represented by the following general formula (1-1).

In general formula (1-1),
R ₃ is the same as X _a1 in the general formula (1).
R ₄ and R ₅ are the same as Rx ₁ and Rx _{2 in} the general formula (1).
- (L) group represented by _n1 -P has the general formula (1) for - (L) is the same as the group represented by _n1 -P.
p represents an integer of 1 to 15. p is preferably 1 or 2, more preferably 1.

Resin (A) is a resin (acid-decomposable resin) whose solubility in an alkaline developer is increased by the action of an acid, and is a group that decomposes to the side chain of the resin by the action of an acid to generate an alkali-soluble group (“ Also referred to as “acid-decomposable group”. A group preferable as a group capable of decomposing with an acid is a group in which a hydrogen atom of an alkali-soluble group such as a —COOH group or —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.

The repeating unit represented by the general formula (1) is a repeating unit having an acid-decomposable group.
The resin (A) may further have a repeating unit having an acid-decomposable group in addition to the repeating unit represented by the general formula (1).

  The resin (A) may further have a repeating unit having a structure selected from the following general formulas (pI) to (pV) as a repeating unit having an acid-decomposable group.

In the general formulas (pI) to (pV),
R ₁₁ represents an alkyl group or a cycloalkyl group.
Z represents an atomic group necessary for forming a cycloalkyl group together with a carbon atom.
R _{12 to} R ₁₄ each independently represents an alkyl group or a cycloalkyl group. However, at least one of R _{12 to} R ₁₄ represents a cycloalkyl group.
R ₁₅ and R ₁₆ each independently represents an alkyl group or a cycloalkyl group. However, either R ₁₅ or R ₁₆ represents a cycloalkyl group.
R _{17 to} R ₂₁ each independently represents a hydrogen atom, an alkyl group or a cycloalkyl group. However, at least one of R _{17 to} R ₂₁ represents a cycloalkyl group. Moreover, any of R ₁₉ and R ₂₁ represents an alkyl group or a cycloalkyl group.
R _{22 to} R ₂₅ each independently represents a hydrogen atom, an alkyl group or a cycloalkyl group. However, at least one of R _{22 to} R ₂₅ represents a cycloalkyl group. R ₂₃ and R ₂₄ may be bonded to each other to form a ring.

In the general formulas (pI) to (pV), the alkyl group in R _{11 to} R ₂₅ is preferably a linear or branched alkyl group having 1 to 8 carbon atoms, such as a methyl group, an ethyl group, or a propyl group. , N-butyl group, sec-butyl group, t-butyl group and the like.

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 4 to 30, and particularly preferably 5 to 25. The cycloalkyl group may have an unsaturated double bond in the ring. The cycloalkyl group may have a substituent.
Further, the cycloalkyl group in R _{11 to} R ₂₅ or the cycloalkyl group formed by Z and the carbon atom is more preferably monocyclic, and the cycloalkyl group preferably has 4 to 10 carbon atoms, most preferably. Has 5 to 7 carbon atoms.

  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.

  These alkyl groups and cycloalkyl groups may further have a substituent. As further substituents for 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 (2 to 2 carbon atoms). 6). The above alkyl group, alkoxy group, alkoxycarbonyl group and the like may further have a substituent. 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 groups represented by the general formulas (pI) to (pV) can form an acid-decomposable group when used for protecting an alkali-soluble 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 group represented by the general formulas (pI) to (pV), preferably a carboxylic acid In this structure, hydrogen atoms of the sulfonic acid group are substituted with groups represented by general formulas (pI) to (pV).

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

In the general formula (pA), 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 is 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 group of two or more groups selected from the group consisting of a ureylene group. Represents. A single bond is preferable.
Rp ₁ represents any one of the general formulas (pI) to (pV).

  Hereinafter, although the specific example of the repeating unit which has an acid-decomposable group is shown, this invention is not limited to this.

In the above structural formulas, Rx represents H, CH ₃ , CF ₃ or CH ₂ OH, and Rxa and Rxb each independently represents an alkyl group having 1 to 4 carbon atoms.

The content of the repeating unit having an acid-decomposable group other than the repeating unit represented by the general formula (1), such as the repeating unit having an acid-decomposable group represented by the general formula (pA), is in the resin (A). The total repeating unit is preferably 20 to 70 mol%, more preferably 30 to 50 mol%.
Moreover, you may have 2 or more types of repeating units which have an acid-decomposable group represented by general formula (pA). The molar ratio of the repeating unit having an acid-decomposable group represented by the two general formulas (pA) at that time is preferably 90/10 to 10/90, more preferably 80/20 to 20/80. It is.

The resin (A) preferably contains a repeating unit having a lactone group.
Any lactone group can be used as long as it has a lactone structure, but it is preferably a 5- to 7-membered ring lactone structure, and forms a bicyclo structure or a spiro structure in the 5- to 7-membered ring lactone structure. The other ring structure is preferably condensed. It is more preferable to have a repeating unit having a lactone structure represented by any 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 a specific lactone structure is used. LWR and 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. More preferably, they are a C1-C4 alkyl group, a cyano group, and an acid-decomposable group. n ₂ represents an integer of 0-4. When n ₂ is 2 or more, a plurality of substituents (Rb ₂ ) may be the same or different, and a plurality of substituents (Rb ₂ ) may be bonded to form a ring. .

  As the repeating unit having a lactone structure, a repeating unit represented by the following general formula (AII) is also preferable.

In general formula (AII),
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. Preferred are a hydrogen atom, a methyl group, a hydroxymethyl group, and a trifluoromethyl group, and a hydrogen atom and a methyl group are particularly preferred.
Ab represents a single bond, an alkylene group, a divalent linking group having a monocyclic or polycyclic alicyclic hydrocarbon structure, an ether group, an ester group, a carbonyl group, or a divalent linking group obtained by combining these. Preferably a single bond, -Ab ₁ -CO ₂ - is a divalent 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 cyclohexylene group, an adamantylene group or a norbornylene group.
V represents a group having a structure represented by any one of the general formulas (LC1-1) to (LC1-16).

  Specific examples of the repeating unit having a lactone group are listed below, but the present invention is not limited thereto.

  Particularly preferred repeating units having a lactone group include the following repeating units. By selecting an optimal lactone group, the pattern profile and the density dependency are improved.

  The resin (A) preferably contains a repeating unit having a lactone structure represented by the following general formula (2) as a repeating unit having a lactone group.

又はウレア結合

を表す。ここで、Ｒは、水素原子、アルキル基、シクロアルキル基、アリール基を表す。
Ｒ₈は、ラクトン構造を有する１価の有機基を表す。
ｎ₂は、一般式（２）で表わされる繰り返し単位内における−Ｒ_０−Ｚ−で表わされる構造の繰り返し数であり、１〜５の整数を表し、１が好ましい。
Ｒ₇は、水素原子、ハロゲン原子又はアルキル基を表す。 In general formula (2),
A represents an ester bond (—COO—) or an amide bond (—CONH—).
R ₀ represents an alkylene group, a cycloalkylene group, or a combination thereof, and when there are a plurality of R _{0 s} , they may be the same or different.
When there are a plurality of Zs, each independently represents an ether bond, an ester bond, an amide bond, or a urethane bond.

Or urea bond

Represents. Here, R represents a hydrogen atom, an alkyl group, a cycloalkyl group, or an aryl group.
R ₈ represents a monovalent organic group having a lactone structure.
n ₂ has the general formula is a repeating number of the structure represented by _-R 0 -Z- in the repeating a unit represented by (2) represents an integer of 1 to 5, 1 is preferable.
R ₇ represents a hydrogen atom, a halogen atom or an alkyl group.

The alkylene group and cycloalkylene group represented by R ₀ may have a substituent.
Z is preferably an ether bond or an ester bond, and particularly preferably an ester bond.

The alkyl group for R ₇ is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and particularly preferably a methyl group. The alkyl group in R ₇ may be substituted. Examples of the substituent include halogen atoms such as fluorine atom, chlorine atom and bromine atom, mercapto group, hydroxy group, methoxy group, ethoxy group, isopropoxy group, t -Acetoxy groups such as alkoxy groups such as butoxy group and benzyloxy group, acetyloxy groups and propionyloxy groups. R ₇ is preferably a hydrogen atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group.
A preferable alkylene group in R ₀ is preferably a linear or branched alkylene having 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and examples thereof include a methylene group, an ethylene group, and a propylene group. . Preferable cycloalkylene is cycloalkylene having 1 to 20 carbon atoms, and examples thereof include cyclohexylene, cyclopentylene, norbornylene, adamantylene and the like. In order to exhibit the effects of the present invention, an alkylene group is more preferable, and a methylene group is particularly preferable.

The monovalent organic group having a lactone structure represented by R ₈ is not limited as long as it has a lactone structure. Specific examples thereof include those represented by the general formulas (LC1-1) to (LC1-16). The lactone structure represented is mentioned, Of these, the structure represented by (LC1-4) is particularly preferable. Further, n ₂ in (LC1-1) to (LC1-16) is more preferably 2 or less.
R ₈ has a monovalent organic group, or a monovalent organic group, more preferably a substituent a cyano group having a lactone structure having a methyl group, a cyano group or an alkoxycarbonyl group as a substituent an unsubstituted lactone structure A monovalent organic group having a lactone structure (cyanolactone) is more preferable.

Specific examples of the repeating unit having a group having a lactone structure represented by the general formula (2) are shown below, but the present invention is not limited thereto.
In the following specific examples, R represents a hydrogen atom, an alkyl group which may have a substituent, or a halogen atom, preferably a hydrogen atom, a methyl group, a hydroxymethyl group or an acetoxymethyl group.

  As the repeating unit having a lactone structure, a repeating unit represented by the following general formula (2-1) is more preferable.

In general formula (2-1),
_{R 7, A, R 0,} Z, and n ₂ are as defined in the general formula (2) in _{R 7, A, R 0,} Z, and the n _2.
Rb independently represents an alkyl group, a cycloalkyl group, an alkoxycarbonyl group, a cyano group, a hydroxyl group or an alkoxy group, and when there are a plurality of Rb, two Rb's are bonded to form a ring. You may do it.
X represents an alkylene group, an oxygen atom, or a sulfur atom.
m is the number of substituents and represents an integer of 0 to 5. m is preferably 0 or 1.

The alkyl group for Rb is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and particularly preferably a methyl group. Examples of the cycloalkyl group include cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl groups. Examples of the alkoxycarbonyl group include a methoxycarbonyl group, an ethoxycarbonyl group, an n-butoxycarbonyl group, and a t-butoxycarbonyl group. Examples of the alkoxy group include a methoxy group, an ethoxy group, an n-butoxy group, and a t-butoxy group. The alkyl group, cycloalkyl group, alkoxycarbonyl group, and alkoxy group of Rb may have a substituent. Examples of the substituent include an alkoxy group such as a hydroxy group, a methoxy group, and an ethoxy group, a cyano group, and a fluorine atom. Can be mentioned. Rb is more preferably a methyl group, a cyano group or an alkoxycarbonyl group, and even more preferably a cyano group.
Examples of the alkylene group for X include a methylene group and an ethylene group. X is preferably an oxygen atom or a methylene group, and more preferably a methylene group.
When m is 1 or more, at least one Rb is preferably substituted at the α-position or β-position of the carbonyl group of the lactone, particularly preferably at the α-position.

Specific examples of the repeating unit having a group having a lactone structure represented by General Formula (2-1) are shown below, but the present invention is not limited thereto.
In the following specific examples, R represents a hydrogen atom, an alkyl group which may have a substituent, or a halogen atom, preferably a hydrogen atom, a methyl group, a hydroxymethyl group or an acetoxymethyl group.

  The repeating unit having a lactone group 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.

As for the content rate of the repeating unit which has a lactone group, 15-60 mol% is preferable with respect to all the repeating units in resin (A), More preferably, it is 20-50 mol%, More preferably, it is 30-50 mol%.
In order to enhance the effect of the present invention, two or more lactone repeating units selected from the general formula (2) can be used in combination. Among the general formula (2) in the case of combination, n ₂ that is preferably used in combination selecting two or more from the lactone repeating units is 1. Further, among the general formula (2), and lactone repeating units n ₂ is 1, it is also preferable n ₂ is used in combination lactone repeating units is zero.

  The resin (A) preferably has a repeating unit having a hydroxyl group or a cyano group other than the general formulas (1) and (AII). This improves the substrate adhesion and developer compatibility. The repeating unit having a hydroxyl group or a cyano group is preferably a repeating unit having an alicyclic hydrocarbon structure substituted with a hydroxyl group or a cyano group, and preferably has no acid-decomposable group. The alicyclic hydrocarbon structure in the alicyclic hydrocarbon structure substituted with a hydroxyl group or a cyano group is preferably an adamantyl group, a diamantyl group, or a norbornane group. As the alicyclic hydrocarbon structure substituted with a preferred hydroxyl group or cyano group, partial structures represented by the following general formulas (VIIa) to (VIId) are preferred.

In general formulas (VIIa) to (VIIc),
R ₂ c to R ₄ c each independently represents a hydrogen atom, a hydroxyl group or a cyano group. However, at least one of R ₂ c to R ₄ c represents a hydroxyl group or a cyano group. Preferably, one or two of R ₂ c to R ₄ c are a hydroxyl group and the remaining is a hydrogen atom. In general formula (VIIa), more preferably, _two of R ₂ c to R ₄ c are hydroxyl groups and the remaining are hydrogen atoms.

  Examples of the repeating unit having a partial structure represented by the general formulas (VIIa) to (VIId) include the repeating units represented by the following general formulas (AIIa) to (AIId).

In the general formulas (AIIa) to (AIId),
R ₁ c represents a hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl group.
R ₂ c to R ₄ c are in the general formula (VIIa) ~ (VIIc), same meanings as R ₂ c~R ₄ c.

  The content of the repeating unit having a hydroxyl group or a cyano group is preferably from 5 to 40 mol%, more preferably from 5 to 30 mol%, still more preferably from 10 to 25 mol%, based on all repeating units in the resin (A).

  Specific examples of the repeating unit having a hydroxyl group or a cyano group are given below, but the present invention is not limited thereto.

  Resin (A) may have a repeating unit having an alkali-soluble group. Examples of the alkali-soluble group include a carboxyl group, a sulfonamide group, a sulfonylimide group, a bisulsulfonylimide group, and an aliphatic alcohol (for example, hexafluoroisopropanol group) substituted with an electron withdrawing group at the α-position. It is more preferable to have a repeating unit. By containing the repeating unit having an alkali-soluble group, the resolution in contact hole applications is increased. The repeating unit having an alkali-soluble group includes 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 an alkali in the main chain of the resin through a linking group. Either a repeating unit to which a soluble group is bonded, or a polymerization initiator or chain transfer agent having an alkali-soluble group is used at the time of polymerization and introduced at the end of the polymer chain. Both are preferable, and the linking group is monocyclic or polycyclic. It may have a cyclic hydrocarbon structure. Particularly preferred are repeating units of acrylic acid or methacrylic acid.

  As for the content rate of the repeating unit which has an alkali-soluble group, 0-20 mol% is preferable with respect to all the repeating units in resin (A), More preferably, it is 3-15 mol%, More preferably, it is 5-10 mol%.

Specific examples of the repeating unit having an alkali-soluble group are shown below, but the present invention is not limited thereto. In specific examples, Rx represents H, CH ₃ , CH ₂ OH, or CF ₃ .

  The resin (A) of the present invention preferably further has a repeating unit that has an alicyclic hydrocarbon structure having no polar group 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. An example of such a repeating unit is a repeating unit represented by the following general formula (3).

In general formula (3), R ₅ represents a hydrocarbon group having at least one cyclic structure and having neither a hydroxyl group nor a cyano group.
Ra represents a hydrogen atom, an alkyl group (which may be substituted with a fluorine atom) or a —CH ₂ —O—Ra ₂ group. In the formula, Ra ₂ represents a hydrogen atom, an alkyl group or an acyl group. Ra is preferably a hydrogen atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group.

The cyclic structure possessed by R ₅ includes a monocyclic hydrocarbon group and a polycyclic hydrocarbon group. Examples of the monocyclic hydrocarbon group include cycloalkenyl having 3 to 12 carbon atoms such as cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group and the like, and cycloalkyl groups having 3 to 12 carbon atoms and cyclohexenyl group. Groups. The preferred monocyclic hydrocarbon group is a monocyclic hydrocarbon group having 3 to 7 carbon atoms, more preferably a cyclopentyl group or a cyclohexyl group.

The polycyclic hydrocarbon group includes a ring assembly hydrocarbon group and a bridged cyclic hydrocarbon group, and examples of the ring assembly hydrocarbon group include a bicyclohexyl group and a perhydronaphthalenyl group. As the bridged cyclic hydrocarbon ring, for example, bicyclic such as pinane, bornane, norpinane, norbornane, bicyclooctane ring (bicyclo [2.2.2] octane ring, bicyclo [3.2.1] octane ring, etc.) Hydrocarbon rings and tricyclic hydrocarbon rings such as homobredan, adamantane, tricyclo [5.2.1.0 ^2,6 ] decane, tricyclo [4.3.1.1 ^2,5 ] undecane ring, tetracyclo [ 4.4.0.1 ^2,5 . 1 ^7,10 ] dodecane, and tetracyclic hydrocarbon rings such as perhydro-1,4-methano-5,8-methanonaphthalene ring. The bridged cyclic hydrocarbon ring includes a condensed cyclic hydrocarbon ring such as perhydronaphthalene (decalin), perhydroanthracene, perhydrophenanthrene, perhydroacenaphthene, perhydrofluorene, perhydroindene, perhydroindene. A condensed ring in which a plurality of 5- to 8-membered cycloalkane rings such as a phenalene ring are condensed is also included.

Preferred examples of the bridged cyclic hydrocarbon ring include a norbornyl group, an adamantyl group, a bicyclooctanyl group, a tricyclo [5,2,1,0 ^2,6 ] decanyl group, and the like. More preferable examples of the bridged cyclic hydrocarbon ring include a norbornyl group and an adamantyl group.

  These alicyclic hydrocarbon groups may have a substituent, and preferred substituents include a halogen atom, an alkyl group, a hydroxyl group protected with a protecting group, an amino group protected with a protecting group, and the like. It is done. Preferred halogen atoms include bromine, chlorine and fluorine atoms, and preferred alkyl groups include methyl, ethyl, butyl and t-butyl groups. The above alkyl group may further have a substituent, and the substituent which may further have a halogen atom, an alkyl group, a hydroxyl group protected with a protecting group, an amino protected with a protecting group The group can be mentioned.

  Examples of the protecting group include an alkyl group, a cycloalkyl group, an aralkyl group, a substituted methyl group, a substituted ethyl group, an alkoxycarbonyl group, and an aralkyloxycarbonyl group. Preferred alkyl groups include alkyl groups having 1 to 4 carbon atoms, preferred substituted methyl groups include methoxymethyl, methoxythiomethyl, benzyloxymethyl, t-butoxymethyl, 2-methoxyethoxymethyl groups, and preferred substituted ethyl groups. 1-ethoxyethyl, 1-methyl-1-methoxyethyl, preferred acyl groups include formyl, acetyl, propionyl, butyryl, isobutyryl, valeryl, pivaloyl groups, etc., aliphatic acyl groups having 1 to 6 carbon atoms, alkoxycarbonyl Examples of the group include an alkoxycarbonyl group having 1 to 4 carbon atoms.

The content of the repeating unit represented by the general formula (3) having neither a hydroxyl group nor a cyano group is preferably from 0 to 40 mol%, more preferably based on all repeating units in the resin (A). 0 to 20 mol%.
Specific examples of the repeating unit represented by the general formula (3) are listed below, but the present invention is not limited to these. In the formula, Ra represents H, CH ₃ , CH ₂ OH, or CF ₃ .

  Resin (A) adjusts dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and resolution, heat resistance, sensitivity, etc., which are general required characteristics of resist, in addition to the above repeating structural units. For this purpose, various repeating structural units can be included.

  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 resin (A), 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 resin (A), the molar ratio of each repeating structural unit is the resist dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and general resist performance required for resolving power, heat resistance, sensitivity. It is set appropriately in order to adjust etc.

When the photosensitive composition of the present invention is for ArF exposure, the resin (A) used in the photosensitive composition of the present invention preferably has no aromatic group from the viewpoint of transparency to ArF light. .
Moreover, it is preferable that resin (A) does not contain a fluorine atom and a silicon atom from a compatible viewpoint with hydrophobic resin (HR) mentioned later.

The resin (A) is preferably one in which all of the repeating units are composed of (meth) acrylate-based repeating units. In this case, all of the repeating units are methacrylate repeating units, all of the repeating units are acrylate repeating units, or all of the repeating units are methacrylate repeating units and acrylate repeating units. Although it can be used, the acrylate-based repeating unit is preferably 50 mol% or less of the total repeating units.
Moreover, the alicyclic hydrocarbon substituted by the (meth) acrylate type repeating unit 20-50 mol% which has an acid-decomposable group, the (meth) acrylate type repeating unit 20-50 mol% which has a lactone group, and a hydroxyl group or a cyano group. A copolymer containing 5 to 30 mol% of a (meth) acrylate-based repeating unit having a structure and further containing 0 to 20 mol% of another (meth) acrylate-based repeating unit is also preferred.

When the photosensitive composition of the present invention is irradiated with KrF excimer laser light, electron beam, X-ray, high energy light beam (EUV, etc.) having a wavelength of 50 nm or less, the resin (A) is further a hydroxystyrene-based repeating unit. It is preferable to have. More preferably, it has a hydroxystyrene-based repeating unit, a hydroxystyrene-based repeating unit protected with an acid-decomposable group, and an acid-decomposable repeating unit such as a (meth) acrylic acid tertiary alkyl ester.
Examples of the repeating unit having a preferred acid-decomposable group based on hydroxystyrene include, for example, t-butoxycarbonyloxystyrene, 1-alkoxyethoxystyrene, a repeating unit of (meth) acrylic acid tertiary alkyl ester, and the like. More preferred are repeating units of 2-alkyl-2-adamantyl (meth) acrylate and dialkyl (1-adamantyl) methyl (meth) acrylate.

110-200 degreeC is preferable and, as for the glass transition temperature (Tg) of resin (A) which the photosensitive composition used in the method of this invention contains, 130-170 degreeC is more preferable. For this purpose, the above-mentioned repeating unit can be used as appropriate. For example, by introducing the repeating unit represented by the general formula (2), the Tg of the resin (A) can be lowered, the ratio of the repeating unit represented by the general formula (1), and the resin (A) The Tg of the resin (A) can be adjusted by appropriately changing the molecular weight of the resin and the ratio of the repeating units that may be contained in the resin (A).
The glass transition point (Tg) is a phenomenon that changes from a glassy hard state to a rubbery state when a polymer substance is heated, and is called a glass transition, and a temperature at which the glass transition occurs is defined as a glass transition point. As a method for measuring Tg, a method based on differential scanning calorimetry (DSC method) can be used. In DSC method, the test piece is heated from room temperature at a rate of 20 ° C / min, the calorific value is measured with a differential scanning calorimeter, and two extension lines are added to the created endothermic curve (two-stage exothermic curve). Tg can be obtained from the intersection of the ½ straight line between the extension lines and the endothermic curve.

The resin (A) of 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 photosensitive 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 examples of the initiator 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 from 10 ° C to 150 ° C, preferably from 30 ° C to 120 ° C, more preferably from 60 ° C to 100 ° C.

The weight average molecular weight of the resin (A) of the present invention is preferably 1,000 to 200,000, more preferably 2,000 to 20,000, still more preferably 3, as a polystyrene conversion value by GPC method. 000 to 15,000, particularly preferably 3,000 to 10,000. By setting the weight average molecular weight to 1,000 to 200,000, deterioration of heat resistance and dry etching resistance can be prevented, and developability is deteriorated, and viscosity is increased, resulting in deterioration of film forming property. Can be prevented.
The degree of dispersion (molecular weight distribution) is usually 1 to 3, preferably 1 to 2.6, more preferably 1 to 2, particularly preferably 1.4 to 2.0. The smaller the molecular weight distribution, the better the resolution and the resist shape, and the smoother the sidewall of the resist pattern, the better the roughness.

The blending amount of the resin (A) in the entire photosensitive composition is preferably 50 to 99.9% by mass, more preferably 60 to 99.0% by mass in the total solid content.
Moreover, the resin (A) of the present invention may be used alone or in combination.
In addition, you may use together other resin other than resin (A) of this invention in the range which does not impair the effect of this invention. Examples of the resin other than the resin (A) of the present invention include an acid-decomposable resin that may contain a repeating unit that can be contained in the resin (A), and other known acid-decomposable resins. be able to.

(B) Compound that generates acid upon irradiation with actinic ray or radiation The photosensitive composition of the present invention contains a compound that generates acid upon irradiation with actinic ray or radiation (hereinafter also referred to as “acid generator”). It is preferable.
As an acid generator, photo-initiator of photocation polymerization, photo-initiator of photo-radical polymerization, photo-decoloring agent of dyes, photo-discoloring agent, or irradiation with actinic ray or radiation used for micro-resist etc. Known compounds that generate acids 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, such as US Pat. No. 3,849,137, German Patent No. No. 3914407, JP-A 63-26653, JP-A 55-164824, JP-A 62-69263, JP-A 63-146038, JP-A 63-163452, The compounds described in JP-A-62-153853 and 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, etc. can also be used.

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

In the general formula (ZI),
R ₂₀₁ , R ₂₀₂ and R ₂₀₃ each independently represents an organic group.
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).
Z ⁻ represents a non-nucleophilic anion.

Examples of the non-nucleophilic anion as Z ⁻ include a sulfonate anion, a carboxylate anion, a sulfonylimide anion, a bis (alkylsulfonyl) imide anion, and a tris (alkylsulfonyl) methyl anion.

  A non-nucleophilic anion is an anion that has an extremely low ability to cause a nucleophilic reaction, and is an anion that can suppress degradation over time due to an intramolecular nucleophilic reaction. This improves the temporal stability of the resist.

  Examples of the sulfonate anion include an aliphatic sulfonate anion, an aromatic sulfonate anion, and a camphor sulfonate anion.

  Examples of the carboxylate anion include an aliphatic carboxylate anion, an aromatic carboxylate anion, and an aralkylcarboxylate anion.

  The aliphatic moiety in the aliphatic sulfonate anion may be an alkyl group or a cycloalkyl group, preferably an alkyl group having 1 to 30 carbon atoms and a cycloalkyl group having 3 to 30 carbon atoms such as methyl. Group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, pentyl group, neopentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group , Tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, eicosyl group, cyclopropyl group, cyclopentyl group, cyclohexyl group, adamantyl group, norbornyl group, bornyl group and the like.

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

  The alkyl group, cycloalkyl group and aryl group in the aliphatic sulfonate anion and aromatic sulfonate anion may have a substituent. Examples of the substituent of the alkyl group, cycloalkyl group, and aryl group in the aliphatic sulfonate anion and aromatic sulfonate anion include, for example, a nitro group, a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), carboxyl group , Hydroxyl group, amino group, cyano group, alkoxy group (preferably having 1 to 15 carbon atoms), cycloalkyl group (preferably having 3 to 15 carbon atoms), aryl group (preferably having 6 to 14 carbon atoms), alkoxycarbonyl group ( Preferably 2 to 7 carbon atoms, acyl group (preferably 2 to 12 carbon atoms), alkoxycarbonyloxy group (preferably 2 to 7 carbon atoms), alkylthio group (preferably 1 to 15 carbon atoms), alkylsulfonyl group (Preferably 1 to 15 carbon atoms), alkyliminosulfonyl group (preferably 2 to 15 carbon atoms), ant Ruoxysulfonyl group (preferably having 6 to 20 carbon atoms), alkylaryloxysulfonyl group (preferably having 7 to 20 carbon atoms), cycloalkylaryloxysulfonyl group (preferably having 10 to 20 carbon atoms), alkyloxyalkyloxy group (Preferably having 5 to 20 carbon atoms), a cycloalkylalkyloxyalkyloxy group (preferably having 8 to 20 carbon atoms), and the like. About the aryl group and ring structure which each group has, an alkyl group (preferably C1-C15) can further be mentioned as a substituent.

  Examples of the aliphatic moiety in the aliphatic carboxylate anion include the same alkyl group and cycloalkyl group as in the aliphatic sulfonate anion.

  Examples of the aromatic group in the aromatic carboxylate anion include the same aryl group as in the aromatic sulfonate anion.

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

  The alkyl group, cycloalkyl group, aryl group and aralkyl group in the aliphatic carboxylate anion, aromatic carboxylate anion and aralkylcarboxylate anion may have a substituent. Examples of the substituent of the alkyl group, cycloalkyl group, aryl group and aralkyl group in the aliphatic carboxylate anion, aromatic carboxylate anion and aralkylcarboxylate anion include, for example, the same halogen atom and alkyl as in the aromatic sulfonate anion Group, cycloalkyl group, alkoxy group, alkylthio group and the like.

  Examples of the sulfonylimide anion include saccharin anion.

  The alkyl group in the bis (alkylsulfonyl) imide anion and tris (alkylsulfonyl) methyl anion is preferably an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, An isobutyl group, a sec-butyl group, a pentyl group, a neopentyl group, and the like can be given. Examples of substituents for these alkyl groups include halogen atoms, alkyl groups substituted with halogen atoms, alkoxy groups, alkylthio groups, alkyloxysulfonyl groups, aryloxysulfonyl groups, cycloalkylaryloxysulfonyl groups, and the like. Alkyl groups substituted with fluorine atoms are preferred.

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

Examples of the non-nucleophilic anion of Z ⁻ include an aliphatic sulfonate anion in which the α-position of the sulfonic acid is substituted with a fluorine atom, an aromatic sulfonate anion substituted with a fluorine atom or a group having a fluorine atom, and an alkyl group. A bis (alkylsulfonyl) imide anion substituted with a fluorine atom and a tris (alkylsulfonyl) methide anion wherein an alkyl group is substituted with a fluorine atom are preferred. The non-nucleophilic anion is more preferably a perfluoroaliphatic sulfonic acid anion having 4 to 8 carbon atoms, a benzenesulfonic acid anion having a fluorine atom, still more preferably a nonafluorobutanesulfonic acid anion, a perfluorooctanesulfonic acid anion, It is a pentafluorobenzenesulfonic acid anion and 3,5-bis (trifluoromethyl) benzenesulfonic acid anion.

Examples of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ include the 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), the structures attached to at least one 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 compounds, namely, compounds containing an arylsulfonium as a cation.

In the 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 or a cycloalkyl group.

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

  The aryl group of the arylsulfonium compound is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group. The aryl group may be an aryl group having a heterocyclic structure having an oxygen atom, a nitrogen atom, a sulfur atom or the like. Examples of the aryl group having a heterocyclic structure include a pyrrole residue (a group formed by losing one hydrogen atom from pyrrole) and a furan residue (a group formed by losing one hydrogen atom from furan). Groups), thiophene residues (groups formed by the loss of one hydrogen atom from thiophene), indole residues (groups formed by the loss of one hydrogen atom from indole), benzofuran residues ( A group formed by losing one hydrogen atom from benzofuran), a benzothiophene residue (a group formed by losing one hydrogen atom from benzothiophene), and the like. 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 or cycloalkyl group that the arylsulfonium compound has as necessary is preferably a linear or branched alkyl group having 1 to 15 carbon atoms and a cycloalkyl group having 3 to 15 carbon atoms, such as a methyl group, Examples thereof include an ethyl group, a propyl group, an n-butyl group, a sec-butyl group, a t-butyl group, a cyclopropyl group, a cyclobutyl group, and a cyclohexyl group.

Aryl group, alkyl group of R ₂₀₁ to R _203, cycloalkyl group, an alkyl group (for example, 1 to 15 carbon atoms), a cycloalkyl group (for example, 3 to 15 carbon atoms), an aryl group (for example, 6 to 14 carbon atoms) , An alkoxy group (for example, having 1 to 15 carbon atoms), a halogen atom, a hydroxyl group, or a phenylthio group may be substituted. Preferred substituents are linear or branched alkyl groups having 1 to 12 carbon atoms, cycloalkyl groups having 3 to 12 carbon atoms, and linear, branched or cyclic alkoxy groups having 1 to 12 carbon atoms, more preferably carbon. These are an alkyl group having 1 to 4 carbon atoms and an alkoxy group having 1 to 4 carbon atoms. 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 which R _{201 to} R ₂₀₃ in formula (ZI) each independently represents an organic group having 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 cycloalkyl group, an allyl group, or a vinyl group, more preferably a linear or branched 2-oxoalkyl group, 2-oxocycloalkyl group, alkoxy group. A carbonylmethyl group, particularly preferably a linear or branched 2-oxoalkyl group.

The alkyl group and cycloalkyl group of R ₂₀₁ to R _203, preferably a linear or branched alkyl group having 1 to 10 carbon atoms (e.g., methyl group, ethyl group, propyl group, butyl group, pentyl group), carbon Examples thereof include cycloalkyl groups of several 3 to 10 (cyclopentyl group, cyclohexyl group, norbornyl group). More preferred examples of the alkyl group include a 2-oxoalkyl group and an alkoxycarbonylmethyl group. More preferred examples of the cycloalkyl group include a 2-oxocycloalkyl group.

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

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

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

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

In general formula (ZI-3),
R _1c to R _5c each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group or a halogen atom.
R _6c and R _7c each independently represents a hydrogen atom, an alkyl group or a cycloalkyl group.
R _x and R _y independently represents an alkyl group, a cycloalkyl group, an allyl group or a vinyl group.

Any two or more of R _{1c to} R _5c , R _6c and R _7c , and R _x and R _y may be bonded to each other to form a ring structure, and this ring structure includes an oxygen atom and a sulfur atom. , An ester bond and an amide bond may be included. Examples of the group formed by combining any two or more of R _{1c to} R _5c , R _6c and R _7c , and R _x and R _y include a butylene group and a pentylene group.

Zc ⁻ represents a non-nucleophilic anion, and examples thereof include the same non-nucleophilic anion as Z ^{− in} formula (ZI).

The alkyl group as R _1c to R _7c may be linear or branched may be any of, for example, alkyl group having 1 to 20 carbon atoms, preferably 1 to 12 linear or branched alkyl group having a carbon number ( Examples thereof include a methyl group, an ethyl group, a linear or branched propyl group, a linear or branched butyl group, and a linear or branched pentyl group. Examples of the cycloalkyl group include cyclohexane having 3 to 8 carbon atoms. An alkyl group (for example, a cyclopentyl group, a cyclohexyl group) can be mentioned.

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, 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 number of R _{1c to} R _5c. Is 2-15. 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 and cycloalkyl group as R _x and R _y include the same alkyl group and cycloalkyl group as in R _{1c to} R _7c , such as a 2-oxoalkyl group, a 2-oxocycloalkyl group, an alkoxy group. A carbonylmethyl group is more preferred.

Examples of the 2-oxoalkyl group and 2-oxocycloalkyl group include a group having> C═O at the 2-position of the alkyl group or cycloalkyl group as R _{1c to} R _7c .

Examples of the alkoxy group in the alkoxycarbonylmethyl group include the same alkoxy groups as in R _{1c to} R _5c .

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

In general formulas (ZII) and (ZIII),
R ₂₀₄ to R ₂₀₇ each independently represents an aryl group, an alkyl group or a cycloalkyl group.

Phenyl group and a naphthyl group are preferred as the aryl group of R ₂₀₄ to R _207, more preferably a phenyl group. Aryl group R ₂₀₄ to R ₂₀₇ represents an oxygen atom, a nitrogen atom, may be an aryl group having a heterocyclic structure having a sulfur atom and the like. Examples of the aryl group having a heterocyclic structure include a pyrrole residue (a group formed by losing one hydrogen atom from pyrrole) and a furan residue (a group formed by losing one hydrogen atom from furan). Groups), thiophene residues (groups formed by the loss of one hydrogen atom from thiophene), indole residues (groups formed by the loss of one hydrogen atom from indole), benzofuran residues ( A group formed by losing one hydrogen atom from benzofuran), a benzothiophene residue (a group formed by losing one hydrogen atom from benzothiophene), and the like.

The alkyl group and cycloalkyl group in R ₂₀₄ to R _207, preferably a linear or branched alkyl group having 1 to 10 carbon atoms (e.g., methyl group, ethyl group, propyl group, butyl group, pentyl group), carbon Examples thereof include cycloalkyl groups of several 3 to 10 (cyclopentyl group, cyclohexyl group, norbornyl group).

Aryl group, alkyl group of R ₂₀₄ to R _207, cycloalkyl groups may have a substituent. Aryl group, alkyl group of R ₂₀₄ to R _207, the cycloalkyl group substituent which may be possessed by, for example, an alkyl group (for example, 1 to 15 carbon atoms), a cycloalkyl group (for example, 3 to 15 carbon atoms ), An aryl group (for example, having 6 to 15 carbon atoms), an alkoxy group (for example, having 1 to 15 carbon atoms), a halogen atom, a hydroxyl group, and a phenylthio group.

Z ⁻ represents a non-nucleophilic anion, and examples thereof include the same as the non-nucleophilic anion of Z ^{− in} formula (ZI).

  Examples of the acid generator further include compounds represented by the following general formulas (ZIV), (ZV), and (ZVI).

In general formulas (ZIV) to (ZVI),
Ar ₃ and Ar ₄ each independently represents an aryl group. R ₂₀₈ , R ₂₀₉ and R ₂₁₀ each independently represents an alkyl group, a cycloalkyl group or an aryl group.
A represents an alkylene group, an alkenylene group or an arylene group.

Among the acid generators, compounds represented by the general formulas (ZI) to (ZIII) are more preferable.
Further, the acid generator is preferably a compound that generates an acid having one sulfonic acid group or imide group, more preferably a compound that generates monovalent perfluoroalkanesulfonic acid, or a monovalent fluorine atom or fluorine atom. A compound that generates an aromatic sulfonic acid substituted with a group that contains a monovalent fluorine atom or an imido acid that is substituted with a group containing a fluorine atom, and even more preferably, a fluorinated compound It is a sulfonium salt of a substituted alkanesulfonic acid, a fluorine-substituted benzenesulfonic acid, a fluorine-substituted imide acid or a fluorine-substituted methide acid. The acid generator that can be used is particularly preferably a fluorinated substituted alkane sulfonic acid, a fluorinated substituted benzene sulfonic acid or a fluorinated substituted imido acid whose pKa of the generated acid is pKa = -1 or less, and the sensitivity is improved. .

  Among acid generators, particularly preferred examples are given below.

  The photosensitive composition of this invention can use the compound which generate | occur | produces the acid corresponding to the anion part in the following general formula (Y) as an acid generator.

Wherein, ^{X +} represents an organic counter ion. R represents a hydrogen atom or an organic group, preferably an organic group having 1 to 40 carbon atoms, more preferably an organic group having 3 to 20 carbon atoms, and represented by the following general formula (YI). Most preferably, it is an organic group.
The organic group for R may have one or more carbon atoms, and preferably, the atom bonded to the oxygen atom in the ester bond represented by the general formula (Y) is a carbon atom, such as an alkyl group, Examples include a cycloalkyl group, an aryl group, an aralkyl group, and a group having a lactone structure, and the chain may have a hetero atom such as an oxygen atom or a sulfur atom. These may have each other as a substituent, and may have a substituent such as a hydroxyl group, an acyl group, an acyloxy group, an oxy group (═O), or a halogen atom.

In formula (YI), Rc represents a monocyclic or polycyclic organic group having 3 to 30 carbon atoms which may contain a cyclic ether, a cyclic thioether, a cyclic ketone, a cyclic carbonate, a lactone, or a lactam structure. Y is a hydroxyl group, a halogen atom, a cyano group, a carboxyl group, a hydrocarbon group having 1 to 10 carbon atoms, a hydroxyalkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or an acyl having 1 to 10 carbon atoms. Group, an alkoxycarbonyl group having 2 to 10 carbon atoms, an acyloxy group having 2 to 10 carbon atoms, an alkoxyalkyl group having 2 to 10 carbon atoms, and a halogenated alkyl group having 1 to 8 carbon atoms. When m = 0 to 6 and there are a plurality of Y, they may be the same as or different from each other. n = 0 to 10.
The total number of carbon atoms constituting the R group represented by the formula (YI) is preferably 40 or less.
It is preferable that n = 0 to 3 and Rc is a monocyclic or polycyclic organic group having 7 to 16.
The molecular weight of the compound represented by the general formula (Y) is generally 300 to 1000, preferably 400 to 800, and more preferably 500 to 700.

Examples of the organic counter ion of X ⁺ include a sulfonium cation and an iodonium cation.
In the compounds of the general formula (Y), as a preferred form, the general formula (Z _SC1) or the general formula (Z _IC1) compound represented by it may be mentioned.

In the general formula (Z _SC1 ), the definition and preferred range of R are the same as those in the general formula (Y).
R ₂₀₁ , R ₂₀₂ and R ₂₀₃ each independently represents an organic group. 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).

Examples of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ include corresponding groups in the compounds (Z _SC1-1 ), (Z _SC1 -2) and (Z _SC1-3 ) which will be described later.

A compound having a plurality of structures represented by the general formula (Z _SC1 ) may also be used. For example, the general formula at least one of R ₂₀₁ to R ₂₀₃ of a compound represented by (Z _SC1), bound to at least one of R ₂₀₁ to R ₂₀₃ of another compound represented by the general formula (Z _SC1) It may be a compound having a structure.

More preferred (Z _SC1 ) components include the compounds (Z _SC1 -1), (Z _SC1 -2), and (Z _SC1 -3) described below.

The compound (Z _SC1-1 ) is an arylsulfonium compound in which at least one of R _{201 to} R _{203 in} the general formula (Z _SC1 ) is an aryl group, that is, a compound having arylsulfonium as a cation.
The definition and preferred range of R are the same as the definition in general formula (Y).

In the 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 or a cycloalkyl group.

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

  The aryl group of the arylsulfonium compound is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group. The aryl group may be an aryl group having a heterocyclic structure having an oxygen atom, a nitrogen atom, a sulfur atom or the like. Examples of the aryl group having a heterocyclic structure include a pyrrole residue (a group formed by losing one hydrogen atom from pyrrole) and a furan residue (a group formed by losing one hydrogen atom from furan). Groups), thiophene residues (groups formed by the loss of one hydrogen atom from thiophene), indole residues (groups formed by the loss of one hydrogen atom from indole), benzofuran residues ( A group formed by losing one hydrogen atom from benzofuran), a benzothiophene residue (a group formed by losing one hydrogen atom from benzothiophene), and the like. 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 or cycloalkyl group that the arylsulfonium compound has as necessary is preferably a linear or branched alkyl group having 1 to 15 carbon atoms and a cycloalkyl group having 3 to 15 carbon atoms, such as a methyl group, Examples thereof include an ethyl group, a propyl group, an n-butyl group, a sec-butyl group, a t-butyl group, a cyclopropyl group, a cyclobutyl group, and a cyclohexyl group.

Aryl group, alkyl group of R ₂₀₁ to R _203, cycloalkyl group, an alkyl group (for example, 1 to 15 carbon atoms), a cycloalkyl group (for example, 3 to 15 carbon atoms), an aryl group (for example, 6 to 14 carbon atoms) , An alkoxy group (for example, having 1 to 15 carbon atoms), a halogen atom, a hydroxyl group, or a phenylthio group may be substituted. Preferred substituents are linear or branched alkyl groups having 1 to 12 carbon atoms, cycloalkyl groups having 3 to 12 carbon atoms, and linear, branched or cyclic alkoxy groups having 1 to 12 carbon atoms, more preferably carbon. These are an alkyl group having 1 to 4 carbon atoms and an alkoxy group having 1 to 4 carbon atoms. 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 (Z _SC1-2 ) will be described.
The definition and preferred range of R are the same as the definition in general formula (Y).
The compound (Z _SC1 -2) is a compound in which R _{201 to} R ₂₀₃ in the formula (Z _SC1 ) each independently represents an organic group having 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 cycloalkyl group, an allyl group, or a vinyl group, more preferably a linear or branched 2-oxoalkyl group, 2-oxocycloalkyl group, alkoxy group. A carbonylmethyl group, particularly preferably a linear or branched 2-oxoalkyl group.

The alkyl group and cycloalkyl group of R ₂₀₁ to R _203, preferably a linear or branched alkyl group having 1 to 10 carbon atoms (e.g., methyl group, ethyl group, propyl group, butyl group, pentyl group), carbon Examples thereof include cycloalkyl groups of several 3 to 10 (cyclopentyl group, cyclohexyl group, norbornyl group). More preferred examples of the alkyl group include a 2-oxoalkyl group and an alkoxycarbonylmethyl group. More preferred examples of the cycloalkyl group include a 2-oxocycloalkyl group.

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

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

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

The compound (Z _SC1 -3) is a compound represented by the following general formula (Z _SC1 -3), and is a compound having a phenacylsulfonium salt structure.

In the general formula (Z _SC1 -3),
The definition and preferred range of R are the same as the definition in general formula (Y).
R _1c to R _5c each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group or a halogen atom.
R _6c and R _7c each independently represents a hydrogen atom, an alkyl group or a cycloalkyl group.
R _x and R _y independently represents an alkyl group, a cycloalkyl group, an allyl group or a vinyl group.

Any two or more of R _{1c to} R _5c , R _6c and R _7c , and R _x and R _y may be bonded to each other to form a ring structure, and this ring structure includes an oxygen atom and a sulfur atom. , An ester bond and an amide bond may be included. Examples of the group formed by combining any two or more of R _{1c to} R _5c , R _6c and R _7c , and R _x and R _y include a butylene group and a pentylene group.

The alkyl group as R _1c to R _7c may be linear or branched may be any of, for example, alkyl group having 1 to 20 carbon atoms, preferably 1 to 12 linear or branched alkyl group having a carbon number ( Examples thereof include a methyl group, an ethyl group, a linear or branched propyl group, a linear or branched butyl group, and a linear or branched pentyl group. Examples of the cycloalkyl group include cyclohexane having 3 to 8 carbon atoms. An alkyl group (for example, a cyclopentyl group, a cyclohexyl group) can be mentioned.

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, 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 number of R _{1c to} R _5c. Is 2-15. 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 and cycloalkyl group as R _x and R _y include the same alkyl group and cycloalkyl group as in R _{1c to} R _7c , such as a 2-oxoalkyl group, a 2-oxocycloalkyl group, an alkoxy group. A carbonylmethyl group is more preferred.

Examples of the 2-oxoalkyl group and 2-oxocycloalkyl group include a group having> C═O at the 2-position of the alkyl group or cycloalkyl group as R _{1c to} R _7c .

Examples of the alkoxy group in the alkoxycarbonylmethyl group include the same alkoxy groups as in R _{1c to} R _5c .

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

In the general formula (Z _IC1 )
The definition and preferred range of R are the same as the definition in general formula (Y).
R ₂₀₄ to R ₂₀₅ each independently represents an aryl group, an alkyl group or a cycloalkyl group.

Phenyl group and a naphthyl group are preferred as the aryl group of R ₂₀₄ to R _205, more preferably a phenyl group. Aryl group R ₂₀₄ to R ₂₀₅ represents an oxygen atom, a nitrogen atom, may be an aryl group having a heterocyclic structure having a sulfur atom and the like. Examples of the aryl group having a heterocyclic structure include a pyrrole residue (a group formed by losing one hydrogen atom from pyrrole) and a furan residue (a group formed by losing one hydrogen atom from furan). Groups), thiophene residues (groups formed by the loss of one hydrogen atom from thiophene), indole residues (groups formed by the loss of one hydrogen atom from indole), benzofuran residues ( A group formed by losing one hydrogen atom from benzofuran), a benzothiophene residue (a group formed by losing one hydrogen atom from benzothiophene), and the like.

The alkyl group and cycloalkyl group in R ₂₀₄ to R _205, preferably a linear or branched alkyl group having 1 to 10 carbon atoms (e.g., methyl group, ethyl group, propyl group, butyl group, pentyl group), carbon Examples thereof include cycloalkyl groups of several 3 to 10 (cyclopentyl group, cyclohexyl group, norbornyl group).

Aryl group, alkyl group of R ₂₀₄ to R _205, cycloalkyl groups may have a substituent. Aryl group, alkyl group of R ₂₀₄ to R _205, the cycloalkyl group substituent which may be possessed by, for example, an alkyl group (for example, 1 to 15 carbon atoms), a cycloalkyl group (for example, 3 to 15 carbon atoms ), An aryl group (for example, having 6 to 15 carbon atoms), an alkoxy group (for example, having 1 to 15 carbon atoms), a halogen atom, a hydroxyl group, and a phenylthio group.

  Specific examples of the compound represented by the general formula (Y) include the following compounds, but are not limited thereto.

The compound represented by the general formula (Y) can be synthesized by a known method, for example, according to the method described in JP-A No. 2007-161707.
The compound represented by general formula (Y) can be used 1 type or in combination of 2 or more types.
An acid generator can be used individually by 1 type or in combination of 2 or more types.
The content of the acid generator in the photosensitive composition is preferably 0.1 to 20% by mass, more preferably 0.5 to 10% by mass, and still more preferably based on the total solid content of the photosensitive composition. 1 to 7% by mass.

Solvents Solvents that can be used when preparing the photosensitive composition by dissolving the above components include, for example, alkylene glycol monoalkyl ether carboxylates, alkylene glycol monoalkyl ethers, lactate alkyl esters, and alkoxypropionate alkyls. And organic solvents such as cyclic lactones (preferably having 4 to 10 carbon atoms), monoketone compounds which may contain rings (preferably having 4 to 10 carbon atoms), alkylene carbonates, alkyl alkoxyacetates and alkyl pyruvates. it can.

Examples of the alkylene glycol monoalkyl ether carboxylate include propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, propylene glycol monomethyl ether propionate, propylene glycol monoethyl Preferred examples include ether propionate, ethylene glycol monomethyl ether acetate, and ethylene glycol monoethyl ether acetate.
Preferred examples of the alkylene glycol monoalkyl ether include propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, ethylene glycol monomethyl ether, and ethylene glycol monoethyl ether.

Preferred examples of the alkyl lactate include methyl lactate, ethyl lactate, propyl lactate and butyl lactate.
Preferable examples of the alkyl alkoxypropionate include ethyl 3-ethoxypropionate, methyl 3-methoxypropionate, methyl 3-ethoxypropionate, and ethyl 3-methoxypropionate.

  Examples of the cyclic lactone include β-propiolactone, β-butyrolactone, γ-butyrolactone, α-methyl-γ-butyrolactone, β-methyl-γ-butyrolactone, γ-valerolactone, γ-caprolactone, and γ-octano. Preferred are iclactone and α-hydroxy-γ-butyrolactone.

  Examples of the monoketone compound which may contain a ring include 2-butanone, 3-methylbutanone, pinacolone, 2-pentanone, 3-pentanone, 3-methyl-2-pentanone, 4-methyl-2-pentanone, 2 -Methyl-3-pentanone, 4,4-dimethyl-2-pentanone, 2,4-dimethyl-3-pentanone, 2,2,4,4-tetramethyl-3-pentanone, 2-hexanone, 3-hexanone, 5-methyl-3-hexanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-methyl-3-heptanone, 5-methyl-3-heptanone, 2,6-dimethyl-4-heptanone, 2-octanone, 3-octanone, 2-nonanone, 3-nonanone, 5-nonanone, 2-decanone, 3-decanone, 4-decanone, 5-hexen-2-one 3-penten-2-one, cyclopentanone, 2-methylcyclopentanone, 3-methylcyclopentanone, 2,2-dimethylcyclopentanone, 2,4,4-trimethylcyclopentanone, cyclohexanone, 3- Methylcyclohexanone, 4-methylcyclohexanone, 4-ethylcyclohexanone, 2,2-dimethylcyclohexanone, 2,6-dimethylcyclohexanone, 2,2,6-trimethylcyclohexanone, cycloheptanone, 2-methylcycloheptanone, 3-methyl Preferred is cycloheptanone.

Preferred examples of the alkylene carbonate include propylene carbonate, vinylene carbonate, ethylene carbonate, and butylene carbonate.
Examples of the alkyl alkoxyacetate include 2-methoxyethyl acetate, 2-ethoxyethyl acetate, 2- (2-ethoxyethoxy) ethyl acetate, 3-methoxy-3-methylbutyl acetate, and 1-methoxy-acetate. 2-propyl is preferred.
Preferred examples of the alkyl pyruvate include methyl pyruvate, ethyl pyruvate, and propyl pyruvate.

As a solvent which can be preferably used, a solvent having a boiling point of 130 ° C. or higher under normal temperature and normal pressure can be mentioned. Specifically, cyclopentanone, γ-butyrolactone, cyclohexanone, ethyl lactate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, ethyl 3-ethoxypropionate, ethyl pyruvate, 2-ethoxyethyl acetate, acetic acid -2- (2-ethoxyethoxy) ethyl and propylene carbonate are mentioned.
In the present invention, the above solvents may be used alone or in combination of two or more.

In this invention, you may use the mixed solvent which mixed the solvent which contains a hydroxyl group in a structure, and the solvent which does not contain a hydroxyl group as an organic solvent.
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 is most 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 solvent is preferably a mixed solvent of two or more containing propylene glycol monomethyl ether acetate.

Basic Compound The photosensitive composition of the present invention preferably contains a basic compound in order to reduce the change in performance over time from exposure to heating.
Preferred examples of the basic compound include compounds having structures represented by the following formulas (A) to (E).

In general formulas (A) and (E),
R ²⁰⁰ , R ²⁰¹ and R ²⁰² may be the same or different, and are a hydrogen atom, an alkyl group (preferably having 1 to 20 carbon atoms), a cycloalkyl group (preferably having 3 to 20 carbon atoms) or an aryl group (having a carbon number). 6-20), wherein R ²⁰¹ and R ²⁰² may combine with each other to form a ring. R ²⁰³ , R ²⁰⁴ , R ²⁰⁵ and R ²⁰⁶ may be the same or different and each represents an alkyl group having 1 to 20 carbon atoms.
About the said alkyl group, as an alkyl group which has a substituent, a C1-C20 aminoalkyl group, a C1-C20 hydroxyalkyl group, or a C1-C20 cyanoalkyl group is preferable.
The alkyl groups in the general formulas (A) and (E) are more preferably unsubstituted.

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

  Examples of the compound having an imidazole structure include imidazole, 2,4,5-triphenylimidazole, benzimidazole, and 2-phenylbenzimidazole. 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. ] Undecar 7-ene etc. are mentioned. Examples of the compound having an onium hydroxide structure include tetrabutylammonium hydroxide, triarylsulfonium hydroxide, phenacylsulfonium hydroxide, sulfonium hydroxide having a 2-oxoalkyl group, specifically, triphenylsulfonium hydroxide, tris ( and t-butylphenyl) sulfonium hydroxide, bis (t-butylphenyl) iodonium hydroxide, phenacylthiophenium hydroxide, 2-oxopropylthiophenium hydroxide, and the like. As the compound having an onium carboxylate structure, an anion portion of the compound having an onium hydroxide structure 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 the aniline compound include 2,6-diisopropylaniline, N, N-dimethylaniline, N, N-dibutylaniline, N, N-dihexylaniline and the like. Examples of the alkylamine derivative having a hydroxyl group and / or an ether bond include ethanolamine, diethanolamine, triethanolamine, N-phenyldiethanolamine, and tris (methoxyethoxyethyl) amine. Examples of aniline derivatives having a hydroxyl group and / or an ether bond include N, N-bis (hydroxyethyl) aniline.

Preferred examples of the basic compound further include an amine compound having a phenoxy group, an ammonium salt compound having a phenoxy group, an amine compound having a sulfonic acid ester group, and an ammonium salt compound having a sulfonic acid ester group.
As the amine compound, a primary, secondary or tertiary amine compound can be used, and an amine compound in which at least one alkyl group is bonded to a nitrogen atom is preferable. The amine compound is more preferably a tertiary amine compound. As long as at least one alkyl group (preferably having 1 to 20 carbon atoms) is bonded to a nitrogen atom, the amine compound has an cycloalkyl group (preferably having 3 to 20 carbon atoms) or an aryl group (preferably having 3 to 20 carbon atoms). Preferably C6-C12) may be bonded to a nitrogen atom. The amine compound preferably has an oxygen atom in the alkyl chain and an oxyalkylene group is formed. The number of oxyalkylene groups is 1 or more, preferably 3 to 9, more preferably 4 to 6 in the molecule. Oxyethylene group (-CH ₂ CH ₂ O-) or an oxypropylene group _{(-CH (CH 3) CH 2} O- or -CH ₂ CH ₂ CH ₂ O-) are preferred among the oxyalkylene groups, more preferably oxy Ethylene group.

As the ammonium salt compound, a primary, secondary, tertiary, or quaternary ammonium salt compound can be used, and an ammonium salt compound in which at least one alkyl group is bonded to a nitrogen atom is preferable. As long as at least one alkyl group (preferably having 1 to 20 carbon atoms) is bonded to a nitrogen atom, the ammonium salt compound has a cycloalkyl group (preferably having 3 to 20 carbon atoms) or an aryl group in addition to the alkyl group. (Preferably having 6 to 12 carbon atoms) may be bonded to a nitrogen atom. The ammonium salt compound preferably has an oxygen atom in the alkyl chain and an oxyalkylene group is formed. The number of oxyalkylene groups is 1 or more, preferably 3 to 9, more preferably 4 to 6 in the molecule. Among the oxyalkylene groups, an oxyethylene group (—CH ₂ CH ₂ O—) or an oxypropylene group (—CH (CH ₃ ) CH ₂ O— or —CH ₂ CH ₂ CH ₂ O—) is preferable, and more preferably oxy Ethylene group.
Examples of the anion of the ammonium salt compound include halogen atoms, sulfonates, borates, and phosphates. Among them, halogen atoms and sulfonates are preferable. As the halogen atom, chloride, bromide, and iodide are particularly preferable. As the sulfonate, an organic sulfonate having 1 to 20 carbon atoms is particularly preferable. Examples of the organic sulfonate include alkyl sulfonates having 1 to 20 carbon atoms and aryl sulfonates. The alkyl group of the alkyl sulfonate may have a substituent, and examples of the substituent include fluorine, chlorine, bromine, alkoxy groups, acyl groups, and aryl groups. Specific examples of the alkyl sulfonate include methane sulfonate, ethane sulfonate, butane sulfonate, hexane sulfonate, octane sulfonate, benzyl sulfonate, trifluoromethane sulfonate, pentafluoroethane sulfonate, and nonafluorobutane sulfonate. Examples of the aryl group of the aryl sulfonate include a benzene ring, a naphthalene ring, and an anthracene ring. The benzene ring, naphthalene ring and anthracene ring may have a substituent, and the substituent is preferably a linear or branched alkyl group having 1 to 6 carbon atoms or a cycloalkyl group having 3 to 6 carbon atoms. Specific examples of the linear or branched alkyl group and cycloalkyl group include methyl, ethyl, n-propyl, isopropyl, n-butyl, i-butyl, t-butyl, n-hexyl, cyclohexyl and the like. Examples of the other substituent include an alkoxy group having 1 to 6 carbon atoms, a halogen atom, cyano, nitro, an acyl group, and an acyloxy group.

The amine compound having a phenoxy group and the ammonium salt compound having a phenoxy group are those having a phenoxy group at the terminal opposite to the nitrogen atom of the alkyl group of the amine compound or ammonium salt compound. The phenoxy group may have a substituent. Examples of the substituent of the phenoxy group include an alkyl group, an alkoxy group, a halogen atom, a cyano group, a nitro group, a carboxyl group, a carboxylic acid ester group, a sulfonic acid ester group, an aryl group, an aralkyl group, an acyloxy group, and an aryloxy group. Etc. The substitution position of the substituent may be any of the 2-6 positions. The number of substituents may be any in the range of 1 to 5.
It is preferable to have at least one oxyalkylene group between the phenoxy group and the nitrogen atom. The number of oxyalkylene groups is 1 or more, preferably 3 to 9, more preferably 4 to 6 in the molecule. Among the oxyalkylene groups, an oxyethylene group (—CH ₂ CH ₂ O—) or an oxypropylene group (—CH (CH ₃ ) CH ₂ O— or —CH ₂ CH ₂ CH ₂ O—) is preferable, and more preferably oxy Ethylene group.

In the amine compound having a sulfonic acid ester group and the ammonium salt compound having a sulfonic acid ester group, the sulfonic acid ester group may be any of alkyl sulfonic acid ester, cycloalkyl group sulfonic acid ester, and aryl sulfonic acid ester. In the case of an alkyl sulfonate ester, the alkyl group has 1 to 20 carbon atoms. In the case of a cycloalkyl sulfonate ester, the cycloalkyl group has 3 to 20 carbon atoms. In the case of an aryl sulfonate ester, the aryl group has 6 carbon atoms. ~ 12 are preferred. Alkyl sulfonic acid ester, cycloalkyl sulfonic acid ester, and aryl sulfonic acid ester may have a substituent. Examples of the substituent include a halogen atom, a cyano group, a nitro group, a carboxyl group, a carboxylic acid ester group, and a sulfonic acid. An ester group is preferred.
It is preferable to have at least one oxyalkylene group between the sulfonate group and the nitrogen atom. The number of oxyalkylene groups is 1 or more, preferably 3 to 9, more preferably 4 to 6 in the molecule. Among the oxyalkylene groups, an oxyethylene group (—CH ₂ CH ₂ O—) or an oxypropylene group (—CH (CH ₃ ) CH ₂ O— or —CH ₂ CH ₂ CH ₂ O—) is preferable, and more preferably oxy Ethylene group.

  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 on the basis of solid content of a photosensitive composition, Preferably it is 0.01-5 mass%.

  The use ratio of the acid generator and the basic compound in the composition is preferably acid generator / basic compound (molar ratio) = 2.5 to 300. In other words, the molar ratio is preferably 2.5 or more from the viewpoint of sensitivity and resolution, and is preferably 300 or less from the viewpoint of suppressing the reduction in resolution due to the thickening of the resist pattern over time until post-exposure heat treatment. The acid generator / basic compound (molar ratio) is more preferably 5.0 to 200, still more preferably 7.0 to 150.

Surfactant The photosensitive composition of the present invention preferably further contains a surfactant, and is a fluorine-based and / or silicon-based surfactant (fluorine-based surfactant, silicon-based surfactant, fluorine atom and silicon). It is more preferable to contain any one or two or more of surfactants having both atoms.

When the photosensitive composition of the present invention contains the above-mentioned surfactant, it provides a resist pattern with less sensitivity and development defects with good sensitivity and resolution when using an exposure light source of 250 nm or less, particularly 220 nm or less. Is possible.
Examples of the fluorine-based and / or silicon-based surfactant 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 F-top EF301, EF303 (manufactured by Shin-Akita Kasei Co., Ltd.), Florard FC430, 431, 4430 (manufactured by Sumitomo 3M Co., Ltd.), MegaFuck F171, F173, F176, F189 , F113, F110, F177, F120, R08 (Dainippon Ink Chemical Co., Ltd.), Surflon S-382, SC101, 102, 103, 104, 105, 106 (Asahi Glass Co., Ltd.), Troisol S-366 (Manufactured by Troy Chemical Co., Ltd.), GF-300, GF-150 (manufactured by Toagosei Chemical Co., Ltd.), Surflon S-393 (manufactured by Seimi Chemical Co., Ltd.), F-top EF121, EF122A, EF122B, RF122C, EF125M , EF135M, EF351, 352, EF801, EF802, EF 01 (manufactured by Gemco), PF636, PF656, PF6320, PF6520 (manufactured by OMNOVA), FTX-204G, 208G, 218G, 230G, 204D, 208D, 212D, 218D, 222D (manufactured by Neos) 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. Or 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 ₃ F ₇ group and (poly (oxy And a copolymer of (ethylene)) acrylate (or methacrylate) and (poly (oxypropylene)) acrylate (or methacrylate).

  In the present invention, other surfactants other than fluorine-based and / or silicon-based surfactants can also be used. Specifically, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, polyoxyethylene alkyl ethers such as polyoxyethylene oleyl ether, polyoxyethylene octylphenol ether, polyoxyethylene nonylphenol ether, etc. Sorbitans such as polyoxyethylene alkyl aryl ethers, polyoxyethylene / polyoxypropylene block copolymers, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, sorbitan tristearate Fatty acid esters, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopa Mite - DOO, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, may be mentioned polyoxyethylene sorbitan tristearate nonionic surfactants of polyoxyethylene sorbitan fatty acid esters such as such.

  These surfactants may be used alone or in several combinations.

  The amount of the 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 photosensitive composition (excluding the solvent).

Carboxylic acid onium salt The photosensitive composition in this invention may contain carboxylic acid onium salt. Examples of the carboxylic acid onium salt include a carboxylic acid sulfonium salt, a carboxylic acid iodonium salt, and a carboxylic acid ammonium salt. In particular, as the carboxylic acid onium salt, an iodonium salt and a sulfonium salt are preferable. Furthermore, it is preferable that the carboxylate residue of the carboxylic acid onium salt of the present invention does not contain an aromatic group or a carbon-carbon double bond. As a particularly preferable anion moiety, a linear, branched, monocyclic or polycyclic alkylcarboxylic acid anion having 1 to 30 carbon atoms is preferable. More preferably, an anion of a carboxylic acid in which some or all of these alkyl groups are fluorine-substituted is preferable. The alkyl chain may contain an oxygen atom. This ensures transparency with respect to light of 220 nm or less, improves sensitivity and resolution, and improves density dependency and exposure margin.

  Fluoro-substituted carboxylic acid anions include fluoroacetic acid, difluoroacetic acid, trifluoroacetic acid, pentafluoropropionic acid, heptafluorobutyric acid, nonafluoropentanoic acid, perfluorododecanoic acid, perfluorotridecanoic acid, perfluorocyclohexanecarboxylic acid, 2 , 2-bistrifluoromethylpropionic acid anion and the like.

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

  The content of the carboxylic acid onium salt in the composition is generally 0.1 to 20% by mass, preferably 0.5 to 10% by mass, more preferably 1 to 7% by mass, based on the total solid content of the composition. %.

Dissolution-inhibiting compound having a molecular weight of 3000 or less that decomposes by the action of an acid to increase the solubility in an alkali developer. Dissolution-inhibiting compound having a molecular weight of 3000 or less that decomposes by the action of an acid to increase the solubility in an alkali developer. (Hereinafter also referred to as “dissolution-inhibiting compound”), since it does not lower the permeability of 220 nm or less, like cholic acid derivatives containing acid-decomposable groups described in Proceeding of SPIE, 2724,355 (1996). An alicyclic or aliphatic compound containing an acid-decomposable group is preferred. Examples of the acid-decomposable group and alicyclic structure are the same as those described for the resin (A).

  When exposing the photosensitive composition of this invention with a KrF excimer laser, or irradiating with an electron beam, what contains the structure which substituted the phenolic hydroxyl group of the phenol compound by the acid-decomposable group is preferable. The phenol compound preferably contains 1 to 9 phenol skeletons, more preferably 2 to 6 phenol skeletons.

  The molecular weight of the dissolution inhibiting 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 inhibiting compound is preferably 3 to 50% by mass, more preferably 5 to 40% by mass, based on the solid content of the photosensitive composition.

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

Other Additives In the photosensitive composition of the present invention, if necessary, a dye, a plasticizer, a photosensitizer, a light absorber, and a compound that promotes solubility in a developer (for example, a molecular weight of 1000 or less). A phenol compound, an alicyclic compound having a carboxyl group, or an aliphatic compound).

Such phenolic compounds having a molecular weight of 1000 or less can be obtained by referring to, for example, the methods described in JP-A-4-1222938, JP-A-2-28531, US Pat. No. 4,916,210, European Patent 219294, etc. It can be easily synthesized by those skilled in the art.
Specific examples of alicyclic or aliphatic compounds having a carboxyl group include carboxylic acid derivatives having a steroid structure such as cholic acid, deoxycholic acid, lithocholic acid, adamantane carboxylic acid derivatives, adamantane dicarboxylic acid, cyclohexane carboxylic acid, cyclohexane Examples thereof include, but are not limited to, dicarboxylic acids.

<Pattern formation method>
The pattern forming method of the present invention comprises a step of forming a resist film using a photosensitive composition containing a resin (A), a step of exposing the resist film, a heating step (PEB step), a development step, [resin ( A post-baking step of heating at a temperature equal to or higher than the glass transition temperature (Tg) -20 ° C. of A).

The photosensitive composition of the present invention is preferably used at a film thickness of 30 to 250 nm, more preferably at a film thickness of 30 to 200 nm, from the viewpoint of improving resolution. Such a film thickness can be obtained by setting the solid content concentration in the photosensitive composition to an appropriate range to give an appropriate viscosity and improving the coating property and film forming property.
The total solid content concentration in the photosensitive composition is generally 1 to 10% by mass, more preferably 1 to 8.0% by mass, and still more preferably 1.0 to 6.0% by mass.

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

For example, the photosensitive composition is applied onto a substrate (eg, silicon / silicon dioxide coating) used for the manufacture of precision integrated circuit elements by an appropriate coating method such as a spinner or coater, and dried to form a resist film. To do.
The resist film is usually exposed by exposure to actinic rays or radiation through a predetermined mask (pattern exposure), post-exposure heating (PEB), development, rinsing and post-baking as necessary. Thereby, a good pattern can be obtained.

Examples of the actinic ray or radiation include infrared light, visible light, ultraviolet light, far ultraviolet light, X-ray, electron beam, etc., preferably 250 nm or less, more preferably 220 nm or less, particularly preferably 1 to 1. Far-ultraviolet light having a wavelength of 200 nm, 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), and electron beam are preferable.

Before forming the resist film, an antireflection film may be coated on the substrate in advance.
As the antireflection film, any of an inorganic film type such as titanium, titanium dioxide, titanium nitride, chromium oxide, carbon, and amorphous silicon, and an organic film type made of a light absorber and a polymer material can be used. In addition, as the organic antireflection film, commercially available organic antireflection films such as DUV30 series, DUV-40 series manufactured by Brewer Science, AR-2, AR-3, AR-5 manufactured by Shipley, etc. may be used. it can.

Post-exposure heating (PEB) can be performed, for example, by heating on a hot plate.
The post-exposure heating temperature is preferably 80 to 130 ° C, more preferably 85 to 110 ° C.
The post-exposure heating time is preferably 30 seconds to 180 seconds, and more preferably 60 seconds to 90 seconds.

In the development step, an alkaline developer is used as follows. Examples of the alkali developer for the photosensitive composition include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia, and primary amines such as ethylamine and n-propylamine. Secondary amines such as diethylamine and di-n-butylamine, tertiary amines such as triethylamine and methyldiethylamine, alcohol amines such as dimethylethanolamine and triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, etc. Alkaline aqueous solutions of quaternary ammonium 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.
Furthermore, an appropriate amount of alcohol or surfactant may be added to the alkaline aqueous solution.
As the rinsing liquid, pure water can be used, and an appropriate amount of a surfactant can be added.
Further, after the development process or the rinsing process, a process of removing the developer or the rinsing liquid adhering to the pattern with a supercritical fluid can be performed.

Next, post-baking is performed at a temperature equal to or higher than [glass transition temperature of resin (A) (Tg) −20 ° C.].
The heating temperature during post-baking is preferably 90 to 170 ° C., more preferably 110 to 150 ° C. [glass transition temperature (Tg) −20 ° C. of resin (A)]. The heating time during post-baking is preferably 60 seconds to 180 seconds, and more preferably 90 seconds to 120 seconds.
Post-baking can be performed, for example, by heating on a hot plate.

  Exposure (immersion exposure) may be performed by filling a liquid (immersion medium) having a higher refractive index than air between the resist 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.

The immersion liquid used for the immersion exposure will be described below.
The immersion liquid is preferably a liquid that is transparent to the exposure wavelength and has a refractive index temperature coefficient as small as possible so as to minimize distortion of the optical image projected onto the resist film. Is an ArF excimer laser (wavelength; 193 nm), it is preferable to use water from the viewpoints of availability and ease of handling in addition to the above-mentioned viewpoints.
Further, a medium having a refractive index of 1.5 or more can be used in that the refractive index can be further improved. This medium may be an aqueous solution or an organic solvent.

When water is used as the immersion liquid, the resist film on the wafer is not dissolved and the influence on the optical coating on the lower surface of the lens element is negligible in order to reduce the surface tension of the water and increase the surface activity. An additive (liquid) may be added in a small proportion. The additive is preferably an aliphatic alcohol having a refractive index substantially equal to that of water, and specifically includes methyl alcohol, ethyl alcohol, isopropyl alcohol and the like. By adding an alcohol having a refractive index substantially equal to that of water, even if the alcohol component in water evaporates and the content concentration changes, an advantage that the change in the refractive index of the entire liquid can be made extremely small can be obtained. On the other hand, when an opaque material or impurities whose refractive index is significantly different from that of water are mixed with 193 nm light, the optical image projected on the resist film is distorted. . Further, pure water filtered through an ion exchange filter or the like may be used.

The electrical resistance of water is desirably 18.3 MQcm or more, the TOC (organic substance concentration) is desirably 20 ppb or less, and deaeration treatment is desirably performed.
Moreover, it is possible to improve lithography performance by increasing the refractive index of the immersion liquid. From such a viewpoint, an additive for increasing the refractive index may be added to water, or heavy water (D ₂ O) may be used instead of water.

When the resist film made of the photosensitive composition of the present invention is exposed through an immersion medium, a hydrophobic resin (HR) can be further added as necessary. As a result, hydrophobic resin (HR) is unevenly distributed on the surface of the resist film, and when the immersion medium is water, the receding contact angle of the resist film surface with respect to the water when the resist film is formed is improved, and the immersion water tracking is improved. Can be made. As the hydrophobic resin (HR), any resin can be used as long as the receding contact angle of the surface can be improved by addition, but a resin having at least one of fluorine atom and silicon atom is preferable. The receding contact angle of the resist film is preferably 60 ° to 90 °, more preferably 70 ° or more. The addition amount can be adjusted as appropriate so that the receding contact angle of the resist film falls within the above range, but is preferably 0.1 to 10% by mass based on the total solid content of the photosensitive composition. Preferably it is 0.1-5 mass%. Hydrophobic resin (HR) is ubiquitous at the interface as described above, but unlike a surfactant, it does not necessarily have a hydrophilic group in the molecule, and polar / nonpolar substances are mixed uniformly. There is no need to contribute.
The receding contact angle is the contact angle measured when the contact line at the droplet-substrate interface recedes, and is useful for simulating the ease of droplet movement under dynamic conditions. It is generally known. In simple terms, it can be defined as the contact angle when the droplet interface recedes when the droplet discharged from the needle tip is deposited on the substrate and then sucked into the needle again. It can be measured by using a contact angle measuring method generally called an expansion / contraction method.
In the immersion exposure process, the immersion head needs to move on the wafer following the movement of the exposure head to scan the wafer at high speed to form the exposure pattern. In this case, the contact angle of the immersion liquid with respect to the resist film is important, and the resist is required to follow the high-speed scanning of the exposure head without remaining droplets.

  The fluorine atom or silicon atom in the hydrophobic resin (HR) may be contained in the main chain of the resin or may be substituted on the side chain.

The hydrophobic resin (HR) is preferably a resin having an alkyl group having a fluorine atom, a cycloalkyl group having a fluorine atom, or an aryl group having a fluorine atom as a partial structure having a fluorine atom.
The alkyl group having a fluorine atom (preferably having 1 to 10 carbon atoms, more preferably 1 to 4 carbon atoms) is a linear or branched alkyl group in which at least one hydrogen atom is substituted with a fluorine atom, It may have a substituent.
The cycloalkyl group having a fluorine atom is a monocyclic or polycyclic cycloalkyl group in which at least one hydrogen atom is substituted with a fluorine atom, and may further have another substituent.
Examples of the aryl group having a fluorine atom include those in which at least one hydrogen atom of an aryl group such as a phenyl group or a naphthyl group is substituted with a fluorine atom, and the aryl group may further have another substituent.

  Preferred examples of the alkyl group having a fluorine atom, the cycloalkyl group having a fluorine atom, or the aryl group having a fluorine atom include groups represented by the following general formulas (F2) to (F4). The present invention is not limited to this.

In general formulas (F2) to (F4),
R _{57 to} R ₆₈ each independently represents a hydrogen atom, a fluorine atom or an alkyl group. However, at least one of R _{57 to} R ₆₁ , R _{62 to} R ₆₄ and R _{65 to} R ₆₈ is a fluorine atom or an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom (preferably having a carbon number of 1 ~ 4). R _{57 to} R ₆₁ and R _{65 to} R ₆₇ are preferably all fluorine atoms. R ₆₂ , R ₆₃ and R ₆₈ are preferably an alkyl group (preferably having 1 to 4 carbon atoms) in which at least one hydrogen atom is substituted with a fluorine atom, and preferably a perfluoroalkyl group having 1 to 4 carbon atoms. Further preferred. R ₆₂ and R ₆₃ may be connected to each other to form a ring.

Specific examples of the group represented by the general formula (F2) include a p-fluorophenyl group, a pentafluorophenyl group, and a 3,5-di (trifluoromethyl) phenyl group.
Specific examples of the group represented by the general formula (F3) include trifluoromethyl group, pentafluoropropyl group, pentafluoroethyl group, heptafluorobutyl group, hexafluoroisopropyl group, heptafluoroisopropyl group, hexafluoro (2 -Methyl) isopropyl group, nonafluorobutyl group, octafluoroisobutyl group, nonafluorohexyl group, nonafluoro-t-butyl group, perfluoroisopentyl group, perfluorooctyl group, perfluoro (trimethyl) hexyl group, 2,2 1,3,3-tetrafluorocyclobutyl group, perfluorocyclohexyl group and the like. Hexafluoroisopropyl group, heptafluoroisopropyl group, hexafluoro (2-methyl) isopropyl group, octafluoroisobutyl group, nonafluoro-t-butyl group and perfluoroisopentyl group are preferable, and hexafluoroisopropyl group and heptafluoroisopropyl group are preferable. Further preferred.
Specific examples of the group represented by the general formula (F4) include, for example, —C (CF ₃ ) ₂ OH, —C (C ₂ F ₅ ) ₂ OH, —C (CF ₃ ) (CH ₃ ) OH, -CH (CF ₃₎ OH and the like, -C (CF _{3) 2} OH is preferred.

Hereinafter, although the specific example of the repeating unit which has a fluorine atom is shown, this invention is not limited to this.
In specific examples, X ₁ represents a hydrogen atom, —CH ₃ , —F or —CF ₃ . X ₂ represents —F or —CF ₃ .

The hydrophobic resin (HR) may contain a silicon atom. The partial structure having a silicon atom is preferably a resin having an alkylsilyl structure (preferably a trialkylsilyl group) or a cyclic siloxane structure.
Specific examples of the alkylsilyl structure or the cyclic siloxane structure include groups represented by the following general formulas (CS-1) to (CS-3).

In general formulas (CS-1) to (CS-3),
R _{12 to} R ₂₆ each independently represents a linear or branched alkyl group (preferably having 1 to 20 carbon atoms) or a cycloalkyl group (preferably having 3 to 20 carbon atoms).
L < ₃ > -L < ₅ > represents a single bond or a bivalent coupling group. As the divalent linking group, an alkylene group, a phenylene group, an ether group, a thioether group, a carbonyl group, an ester group, an amide group, a urethane group, or a group selected from the group consisting of a ureylene group or two or more groups. A combination is mentioned.
n represents an integer of 1 to 5. n is preferably an integer of 2 to 4.

Hereinafter, although the specific example of the repeating unit which has group represented by general formula (CS-1)-(CS-3) is given, this invention is not limited to this. In specific examples, X ₁ represents a hydrogen atom, —CH ₃ , —F or —CF ₃ .

Furthermore, the hydrophobic resin (HR) may have at least one group selected from the following groups (x) to (z).
(X) an alkali-soluble group,
(Y) a group that decomposes by the action of an alkali developer and increases the solubility in the alkali developer;
(Z) A group that decomposes by the action of an acid.

(X) Alkali-soluble groups include phenolic hydroxyl groups, carboxylic acid groups, fluorinated alcohol groups, sulfonic acid groups, sulfonamido groups, sulfonylimide groups, (alkylsulfonyl) (alkylcarbonyl) methylene groups, (alkylsulfonyl) ( Alkylcarbonyl) imide group, bis (alkylcarbonyl) methylene group, bis (alkylcarbonyl) imide group, bis (alkylsulfonyl) methylene group, bis (alkylsulfonyl) imide group, tris (alkylcarbonyl) methylene group, tris (alkylsulfonyl) ) And a methylene group.
Preferred alkali-soluble groups include fluorinated alcohol groups (preferably hexafluoroisopropanol), sulfonimide groups, and bis (carbonyl) methylene groups.

Examples of the repeating unit having an alkali-soluble group (x) 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 main group of the resin via a linking group. Examples include a repeating unit in which an alkali-soluble group is bonded to the chain. Furthermore, a polymerization initiator or a chain transfer agent having an alkali-soluble group can be introduced at the end of the polymer chain at the time of polymerization. Is also preferable.
The content of the repeating unit having an alkali-soluble group (x) is preferably from 1 to 50 mol%, more preferably from 3 to 35 mol%, still more preferably from 5 to 20 mol%, based on all repeating units in the polymer.

  Specific examples of the repeating unit having an alkali-soluble group (x) are shown below, but the present invention is not limited thereto.

(Y) Examples of the group that decomposes by the action of an alkali developer and increases the solubility in the alkali developer include a group having a lactone structure, an acid anhydride group, an acid imide group, and the like, and preferably a lactone A group having a structure.
As the repeating unit having a group (y) that is decomposed by the action of an alkali developer and increases the solubility in the alkali developer, an alkali is added to the main chain of the resin, such as a repeating unit of an acrylate ester or a methacrylate ester. A polymerization initiator having a repeating unit to which a group (y) that decomposes by the action of the developer and increases the solubility in an alkali developer is bonded, or a group (y) that increases the solubility in an alkali developer And a chain transfer agent used at the time of polymerization are preferably introduced at the end of the polymer chain.
The content of the repeating unit having a group (y) whose solubility in an alkali developer is increased is preferably 1 to 40 mol%, more preferably 3 to 30 mol%, still more preferably based on all repeating units in the polymer. 5 to 15 mol%.

  Specific examples of the repeating unit having a group (y) that increases the solubility in an alkali developer include the same repeating units as those having a lactone structure exemplified for the resin of the component (B).

  In the hydrophobic resin (HR), examples of the repeating unit having a group (z) that is decomposed by the action of an acid are the same as the repeating unit having an acid-decomposable group exemplified in the resin of the component (B). . In the hydrophobic resin (HR), the content of the repeating unit having a group (z) that is decomposed by the action of an acid is preferably 1 to 80 mol%, more preferably 10 to 10%, based on all repeating units in the polymer. 80 mol%, more preferably 20 to 60 mol%.

  The hydrophobic resin (HR) may further have a repeating unit represented by the following general formula (III).

In general formula (III):
R _{c 31} represents a hydrogen atom, an alkyl group, or an alkyl group which may be substituted by fluorine, a cyano group or -CH ₂ -O-Rac ₂ group. Wherein, Rac ₂ represents a hydrogen atom, an alkyl group or an acyl group. R _c31 is preferably a hydrogen atom, a methyl group, a hydroxymethyl group or a trifluoromethyl group, particularly preferably a hydrogen atom or a methyl group.
R _c32 represents a group having an alkyl group, a cycloalkyl group, an alkenyl group, or a cycloalkenyl group. These groups may be substituted with a fluorine atom or a silicon atom.
L _c3 represents a single bond or a divalent linking group.

In general formula (III), the alkyl group represented by R _c32 is preferably a linear or branched alkyl group having 3 to 20 carbon atoms.
The cycloalkyl group is preferably a cycloalkyl group having 3 to 20 carbon atoms.
The alkenyl group is preferably an alkenyl group having 3 to 20 carbon atoms.
The cycloalkenyl group is preferably a cycloalkenyl group having 3 to 20 carbon atoms.
R _c32 is preferably an unsubstituted alkyl group or an alkyl group substituted with a fluorine atom.
The divalent linking group of L _c3 is preferably an ester group, an alkylene group (preferably having a carbon number of 1 to 5), an oxy group, a phenylene group, or an ester bond (a group represented by —COO—).

It is also preferable that the hydrophobic resin (HR) further has a repeating unit represented by the following general formula (CII-AB).

In the formula (CII-AB),
R _c11 ′ and R _c12 ′ each independently represents a hydrogen atom, a cyano group, a halogen atom or an alkyl group.
Zc ′ represents an atomic group for forming an alicyclic structure containing two bonded carbon atoms (C—C).
Specific examples of the repeating unit represented by the general formulas (III) and (CII-AB) are shown below, but the present invention is not limited thereto. In the formula, Ra represents H, CH ₃ , CH ₂ OH, CF ₃ or CN.

When the hydrophobic resin (HR) has a fluorine atom, the fluorine atom content is preferably 5 to 80% by mass, and 10 to 80% by mass with respect to the molecular weight of the hydrophobic resin (HR). Is more preferable. Moreover, it is preferable that the repeating unit containing a fluorine atom is 10-100 mass% in hydrophobic resin (HR), and it is more preferable that it is 30-100 mass%.
When the hydrophobic resin (HR) has a silicon atom, the content of the silicon atom is preferably 2 to 50% by mass and preferably 2 to 30% by mass with respect to the molecular weight of the hydrophobic resin (HR). Is more preferable. Moreover, it is preferable that it is 10-100 mass% in hydrophobic resin (HR), and, as for the repeating unit containing a silicon atom, it is more preferable that it is 20-100 mass%.

  The weight average molecular weight of the hydrophobic resin (HR) in terms of standard polystyrene is preferably 1,000 to 100,000, more preferably 1,000 to 50,000, and even more preferably 2,000 to 15,000. is there.

  As for the hydrophobic resin (HR), it is preferable that the residual monomer and oligomer components are 0 to 10% by mass, more preferably, as in the resin of the component (B), there are few impurities such as metals. Is more preferably 0 to 5% by mass and 0 to 1% by mass. Thereby, a resist having no change over time such as foreign matter in liquid or sensitivity can be obtained. The molecular weight distribution (Mw / Mn, also referred to as dispersity) is preferably in the range of 1 to 5, more preferably 1 to 3, and still more preferably from the viewpoints of resolution, resist shape, resist pattern sidewall, roughness, and the like. It is the range of 1-2.

  As the hydrophobic resin (HR), various commercially available products can be used, or they 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 and 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 above-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 photosensitive 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 examples of the initiator include azobisisobutyronitrile, azobisdimethylvaleronitrile, dimethyl 2,2′-azobis (2-methylpropionate) and the like. The concentration of the reaction is 5 to 50% by mass, preferably 30 to 50% by mass. The reaction temperature is usually from 10 ° C to 150 ° C, preferably from 30 ° C to 120 ° C, more preferably from 60 ° C to 100 ° C.

  After completion of the reaction, the mixture is allowed to cool to room temperature and purified. Purification can be accomplished by a liquid-liquid extraction method that removes residual monomers and oligomer components by combining water and an appropriate solvent, and a purification method in a solution state such as ultrafiltration that extracts and removes only those having a specific molecular weight or less. , Reprecipitation method that removes residual monomer by coagulating resin in poor solvent by dripping resin solution into poor solvent and purification in solid state such as washing filtered resin slurry with poor solvent A normal method such as a method can be applied. For example, the resin is precipitated as a solid by contacting a solvent (poor solvent) in which the resin is hardly soluble or insoluble in a volume amount of 10 times or less, preferably 10 to 5 times that of the reaction solution.

  The solvent (precipitation or reprecipitation solvent) used in the precipitation or reprecipitation operation from the polymer solution may be a poor solvent for the polymer, and may be a hydrocarbon, halogenated hydrocarbon, nitro, depending on the type of polymer. A compound, ether, ketone, ester, carbonate, alcohol, carboxylic acid, water, a mixed solvent containing these solvents, and the like can be appropriately selected for use. Among these, as a precipitation or reprecipitation solvent, a solvent containing at least an alcohol (particularly methanol or the like) or water is preferable.

  The amount of the precipitation or reprecipitation solvent used can be appropriately selected in consideration of efficiency, yield, and the like, but generally 100 to 10000 parts by mass, preferably 200 to 2000 parts by mass with respect to 100 parts by mass of the polymer solution, More preferably, it is 300-1000 mass parts.

  The temperature for precipitation or reprecipitation can be appropriately selected in consideration of efficiency and operability, but is usually about 0 to 50 ° C., preferably around room temperature (for example, about 20 to 35 ° C.). The precipitation or reprecipitation operation can be performed by a known method such as a batch method or a continuous method using a conventional mixing vessel such as a stirring tank.

  The precipitated or re-precipitated polymer is usually subjected to conventional solid-liquid separation such as filtration and centrifugation, and dried before use. Filtration is performed using a solvent-resistant filter medium, preferably under pressure. Drying is performed at a temperature of about 30 to 100 ° C., preferably about 30 to 50 ° C. under normal pressure or reduced pressure (preferably under reduced pressure).

  In addition, once the resin is precipitated and separated, it may be dissolved again in a solvent, and the resin may be brought into contact with a hardly soluble or insoluble solvent. That is, after completion of the radical polymerization reaction, a solvent in which the polymer is hardly soluble or insoluble is brought into contact, the resin is precipitated (step a), the resin is separated from the solution (step b), and dissolved again in the solvent. (Step c), and then contact the resin solution A with a solvent in which the resin is hardly soluble or insoluble in a volume amount less than 10 times that of the resin solution A (preferably 5 times or less volume). This may be a method including precipitating a resin solid (step d) and separating the precipitated resin (step e).

  Specific examples of the hydrophobic resin (HR) are shown below. Table 1 below shows the molar ratio of repeating units in each resin (corresponding to each repeating unit in order from the left), the weight average molecular weight, and the degree of dispersion.

In order to prevent the resist film from coming into direct contact with the immersion liquid between the resist film of the photosensitive composition of the present invention and the immersion liquid, an immersion liquid hardly soluble film (hereinafter also referred to as “topcoat”). May be provided. The functions necessary for the top coat are suitability for application to the upper layer of the resist, transparency to radiation, particularly 193 nm, and poor immersion liquid solubility. It is preferable that the top coat is not mixed with the resist and can be uniformly applied to the upper layer of the resist.
From the viewpoint of 193 nm transparency, the top coat is preferably a polymer that does not contain abundant aromatics. Specifically, the polymer contains a hydrocarbon polymer, an acrylate polymer, polymethacrylic acid, polyacrylic acid, polyvinyl ether, and silicon. Examples thereof include a polymer and a fluorine-containing polymer. The aforementioned hydrophobic resin (HR) is also suitable as a top coat. From the viewpoint of contaminating the optical lens when impurities are eluted from the top coat into the immersion liquid, it is preferable that the residual monomer component of the polymer contained in the top coat is small.

When peeling the top coat, a developer may be used, or a separate release agent may be used. As the release agent, a solvent having a small penetration into the resist film is preferable. It is preferable that the peeling process can be performed with an alkali developer in that the peeling process can be performed simultaneously with the resist film development process. From the viewpoint of peeling with an alkaline developer, the topcoat is preferably acidic, but may be neutral or alkaline from the viewpoint of non-intermixability with the resist film.
The resolution is improved when there is no difference in refractive index between the top coat and the immersion liquid. In the case of using water as the immersion liquid in an ArF excimer laser (wavelength: 193 nm), the top coat for ArF immersion exposure is preferably close to the refractive index of the immersion liquid. From the viewpoint of making the refractive index close to the immersion liquid, it is preferable to have fluorine atoms in the topcoat. A thin film is more preferable from the viewpoint of transparency and refractive index.

  The top coat is preferably not mixed with the resist film and further not mixed with the immersion liquid. From this viewpoint, when the immersion liquid is water, the solvent used for the topcoat is preferably a non-water-soluble medium that is hardly soluble in the solvent used for the photosensitive composition. Further, when the immersion liquid is an organic solvent, the topcoat may be water-soluble or water-insoluble.

EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited to a following example.
Below, the monomer corresponding to each repeating unit used for the synthesis | combination of resin (A) used for the present Example is shown.

Synthesis Example 1 (Synthesis of Resin (A-1))
Under a nitrogen stream, 8.8 g of cyclohexanone was placed in a three-necked flask and heated to 80 ° C. To this, 8.5 g of monomer (LM-1), 8.8 g of monomer (IM-2), 4.7 g of monomer (PM-1), and 13 mol of polymerization initiator V-60 (manufactured by Wako Pure Chemical Industries) with respect to the monomer % In cyclohexanone 79 g was added dropwise over 6 hours. After completion of dropping, the reaction was further continued at 80 ° C. for 2 hours. The reaction solution was allowed to cool and then added dropwise to a mixed solution of 900 m of methanol / 100 ml of water over 20 minutes. The precipitated powder was collected by filtration and dried to obtain 18 g of Resin (A-1). The composition ratio (molar ratio of repeating units in the order from the left repeating unit) of the obtained resin (A-1) is 49/11/40, the weight average molecular weight is 8200 in terms of standard polystyrene, dispersity ( Mw / Mn) was 1.53.

Resins (A-2) to (A-16) were synthesized in the same manner as in Synthesis Example 1.
The structure is shown below.

  Table 2 below shows the monomers used for synthesis, the composition ratio (molar ratio of monomers), the weight average molecular weight, and the degree of dispersion of the resins (A-1) to (A-16). The molar ratio of the monomers corresponds in order from the left of each monomer.

Examples 1-13 and Comparative Examples 1-4
Components shown in Table 3 below were dissolved in a solvent to prepare a solution, which was filtered through a polyethylene filter having a pore size of 0.1 μm to prepare a positive resist solution. The prepared positive resist solution was evaluated by the following method.
In Comparative Example 4 in Table 4, a positive resist solution similar to the positive resist solution in Example 1 was used.
An anti-reflective film ARC29A manufactured by Nissan Chemical Co., Ltd. was uniformly applied with a film thickness of 78 nm on the silicon substrate with a spin coater, dried on a hot plate at 205 ° C. for 60 seconds, and then cooled to room temperature. Thereafter, each positive resist solution was applied by a spin coater and dried at 100 ° C. for 60 seconds to form a resist film having a thickness of 120 nm.
The resist film was exposed with an ArF excimer laser stepper (SM = NA = 0.75) through a 75 nm 1: 1 line and space mask while changing the exposure amount. After heating on a hot plate for 60 seconds at temperature, it was cooled to room temperature. Further, the film was developed with an aqueous 2.38 mass% tetramethylammonium hydroxide solution at 23 ° C. for 30 seconds, rinsed with pure water for 30 seconds, and then heated on a hot plate for 90 seconds at the post-bake temperature shown in Table 4 to obtain a line. Got a pattern.
LWR evaluation:
In the standard resist evaluation, the line pattern finished to 75 nm was observed with a scanning microscope (S9380 manufactured by Hitachi, Ltd.), and the line width was measured at 50 points in the range of 2 μm edge in the longitudinal direction of the line pattern. The standard deviation was calculated for 3 and 3σ was calculated. A smaller value indicates better performance.
Pattern collapse evaluation:
A line pattern of 75 nm (line / space = 1/1) was formed by the same method as the LWR evaluation method. When the exposure amount that reproduces the mask pattern of 75 nm line and space is the optimum exposure amount, and the line width of the line pattern formed by further increasing the exposure amount from the optimum exposure amount is reduced, the pattern does not collapse It was defined by the line width (nm) to be resolved. A smaller value indicates that a finer pattern is resolved without falling, and pattern falling is less likely to occur.
The results of the above evaluation are shown in Table 4.
Moreover, the glass transition temperature of resin (A) was calculated | required with the following method, and was shown in Table 4.
〔Glass-transition temperature〕
The Tg of the resin shown in Table 4 was determined by heating the resin sample at a rate of 20 ° C./min from room temperature by DSC method, measuring the calorific value with a differential scanning calorimeter, Two extension lines were drawn on the exothermic curve), and Tg was determined from the intersection of the 1/2 line between the extension lines and the endothermic curve.

  The compounds corresponding to the abbreviations in Table 3 are the compounds shown below.

N-1: N, N-dibutylaniline N-2: trioctylamine N-3: N, N-dihydroxyethylaniline N-4: 2,4,5-triphenylimidazole N-5: 2,6-diisopropyl Aniline N-6: Hydroxyantipyrine N-7: Trismethoxymethoxyethylamine N-8: Triethanolamine

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.)
W-5: KH-20 (Asahi Kasei Corporation)
W-6: PF6320 (made by OMNOVA)
W-7: PF6520 (made by OMNOVA)

SL-1: Propylene glycol monomethyl ether acetate (PGMEA)
SL-2: Propylene glycol monomethyl ether propionate SL-3: 2-heptanone SL-4: Ethyl lactate SL-5: Propylene glycol monomethyl ether (PGME)
SL-6: Cyclohexanone SL-7: γ-Butyrolactone SL-8: Propylene carbonate

  From Table 4, it is clear that the pattern forming method of the present invention is an excellent method that achieves both LWR suppression and pattern collapse suppression.

Examples 14-27 and Comparative Examples 5-8
The components shown in Table 5 below were dissolved in a solvent to prepare a solution, which was filtered through a polyethylene filter having a pore size of 0.1 μm to prepare a positive resist solution. The prepared positive resist solution was evaluated by the following method.
In Comparative Example 8, a positive resist solution similar to the positive resist solution in Example 14 was used.
Immersion exposure evaluation:
This condition is to form a resist pattern by an immersion exposure method using pure water.
An organic antireflection film ARC29A (Nissan Chemical Co., Ltd.) was applied on a silicon wafer and baked at 205 ° C. for 60 seconds to form an antireflection film having a thickness of 78 nm. A positive resist solution prepared thereon was applied and baked at 100 ° C. for 60 seconds to form a resist film having a thickness of 100 nm. The resist film was subjected to pattern exposure using an ArF excimer laser immersion scanner (NA 0.85, scan speed 500 mm / s) through a 65 nm 1: 1 line and space mask. Ultra pure water was used as the immersion liquid. Immediately after exposure, the plate was heated on a hot plate for 60 seconds at the PEB temperature shown in Table 6 below, and then cooled to room temperature. Further, the film was developed with an aqueous 2.38 mass% tetramethylammonium hydroxide solution at 23 ° C. for 30 seconds, rinsed with pure water for 30 seconds, and then heated on a hot plate for 90 seconds at the post-bake temperature shown in Table 6, Got a pattern.
LWR evaluation:
In the standard resist evaluation, the line pattern finished to 65 nm was observed with a scanning microscope (S9380 manufactured by Hitachi, Ltd.), and the line width was measured at 50 points in the range of 2 μm edge in the longitudinal direction of the line pattern. The standard deviation was calculated for 3 and 3σ was calculated. A smaller value indicates better performance.
Pattern collapse evaluation:
A line pattern of 65 nm (line / space = 1/1) was formed by the same method as the LWR evaluation method. The exposure amount that reproduces the 65nm line and space mask pattern is the optimum exposure amount, and when the line width of the line pattern formed by further increasing the exposure amount from the optimum exposure amount is reduced, the pattern does not collapse It was defined by the line width (nm) to be resolved. A smaller value indicates that a finer pattern is resolved without falling, and pattern falling is less likely to occur.
The results of the above evaluation are shown in Table 6. Table 6 shows the glass transition temperature of the resin (A) used.

  From the above, it was confirmed that the pattern forming method of the present invention is an excellent method that achieves both LWR suppression and pattern collapse suppression even in pattern formation by ArF immersion exposure.

Claims (6)

A step of forming a resist film using a photosensitive composition containing a resin (A) having at least a repeating unit represented by the following general formula (1) and increasing the solubility in an alkali developer by the action of an acid And a step of exposing the resist film, a heating step (PEB step), a development step, and a post-bake step, and the heating temperature in the post-bake step is [glass transition temperature (Tg) -20 ° C. of resin (A)] A pattern forming method comprising a step of post-baking at the above temperature.

In general formula (1),
Xa ₁ represents a hydrogen atom, a methyl group or a group represented by —CH ₂ —R ₉ . R ₉ represents a hydroxyl group or a monovalent organic group.
Rx _{1 to} Rx ₃ each independently represents an alkyl group or a cycloalkyl group. Two of Rx _{1 to} Rx ₃ may combine to form a cycloalkyl group.
Incidentally, the group represented by -C in the general formula _{(1) (Rx 1) (} Rx 2) (Rx 3) has at least one - as a substituent having an (L) group represented by _n1 -P.
L represents a divalent linking group.
n ₁ is 0 or 1.
P represents a polar group. The pattern forming method according to claim 1, wherein the resin (A) is a resin further having a repeating unit represented by the following general formula (2).

In general formula (2),
A represents an ester bond or an amide bond.
R ₀ represents an alkylene group, a cycloalkylene group or a divalent linking group obtained by combining them, and when there are a plurality of R ₀ groups, they may be the same or different.
Z represents an ether bond, an ester bond, an amide bond, a urethane bond, a urea bond or a combination thereof, and when there are a plurality thereof, they may be the same or different.
R ₈ represents a monovalent organic group having a lactone structure.
n ₂ has the general formula is a repeating number of the structure represented by _-R 0 -Z- in the repeating a unit represented by (2), represents an integer of 1 to 5.
R ₇ represents a hydrogen atom, a halogen atom or an alkyl group.   The pattern forming method according to claim 1, wherein the photosensitive composition further contains a compound that generates an acid upon irradiation with actinic rays or radiation. Resin (A) contains the repeating unit represented by General formula (1) whose P is a hydroxyl group, The photosensitive composition in any one of Claims 1-3 characterized by the above-mentioned. Resin (A) The pattern forming method according to claim 1, characterized in that it contains a repeating unit n ₂ is represented by the general formula (2) is 1. Resin (A) contains the repeating unit represented by General formula (3) further, The pattern formation method in any one of Claims 1-5 characterized by the above-mentioned.

In general formula (3), R ₅ represents a hydrocarbon group having at least one cyclic structure and having neither a hydroxyl group nor a cyano group.
Ra represents a hydrogen atom, an alkyl group, or a —CH ₂ —O—Ra ₂ group. In the formula, Ra ₂ represents a hydrogen atom, an alkyl group or an acyl group.