JP2011186091A - Pattern forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pattern forming method excellent in exposure latitude (EL) and performance of preventing development defects. <P>SOLUTION: The pattern forming method includes: forming a film by using an active ray-sensitive or radiation-sensitive resin composition containing (A) a resin whose solubility with an alkali developing solution is increased by the action of an acid and (B) a compound that generates an acid having a moiety structure expressed by general formula (LD) by irradiation with active rays or radiation; exposing the film; and developing the exposed film by using an aqueous solution of tetramethylammonium hydroxide having a concentration of less than 2.38 mass%. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a pattern forming method. More specifically, the present invention relates to an ultra-microlithographic process applicable to a manufacturing process of a VLSI and a high-capacity microchip, a process for producing a mold for nanoimprinting, a manufacturing process of a high-density information recording medium, and other photofabrication. The present invention relates to a pattern forming method suitably used in a process. In particular, the present invention relates to a pattern forming method suitable for exposure using an immersion projection exposure apparatus that uses far ultraviolet light having a wavelength of 300 nm or less as a light source.

  Here, “active light” or “radiation” means, for example, an emission line spectrum of a mercury lamp, far ultraviolet rays represented by an excimer laser, extreme ultraviolet rays (EUV) rays, X rays or electron rays (EB). Yes. In the present invention, “light” means actinic rays or radiation.

  In addition, “exposure” means not only light irradiation with a mercury lamp, far ultraviolet rays, X-rays, EUV light, etc., but also drawing with particle beams such as electron beams and ion beams, unless otherwise specified. .

  Since the resist for KrF excimer laser (248 nm), a pattern formation method using chemical amplification has been used to compensate for the sensitivity reduction due to light absorption. In this method, typically, a photosensitive composition containing a resin whose solubility in an alkaline developer is increased by the action of an acid and an acid generator that generates an acid upon irradiation with light (for example, a patent) References 1 to 5 and Non-Patent Reference 1).

  In the positive chemical amplification method, first, a film is formed using a photosensitive composition. The film is then exposed. Thereby, at least a part of the photoacid generator contained in the exposed portion is decomposed to generate an acid. And, for example, an alkali-insoluble group contained in the resin is changed to an alkali-soluble group by the catalytic action of the acid. Subsequently, the exposed film is processed using an alkali developer. Thereby, only the exposed portion of the film is removed to obtain a desired pattern.

  As the alkaline developer, a strong basic alkaline aqueous solution is usually used. In manufacturing processes of semiconductors and the like, a TMAH (tetramethylammonium hydroxide) aqueous solution having a concentration of 2.38% by mass is widely used as the alkali developer (for example, Patent Documents 1 to 5 and Non-Patent Document 1). reference). This concentration is set to optimize the dissolution rate of the G-line or I-line resist, but it is a fact that other resists that are currently being studied use this concentration of TMAH aqueous solution. It is the above technical standard.

US Patent Application Publication No. 2009 / 0239179A1 JP 2009-223300 A JP 2009-235118 A JP 2008-292975 A JP 2008-111103 A

SPIE, 1998, Vol.920, 226-232

  An object of the present invention is to provide a pattern forming method excellent in exposure latitude (EL) and development defect performance.

  For example, the present invention is as follows.

[1] Resin (A) whose solubility in an alkaline developer is increased by the action of an acid, and a compound (B) that generates an acid having a partial structure represented by the following general formula (LD) by irradiation with actinic rays or radiation ) Containing the actinic ray-sensitive or radiation-sensitive resin composition, exposing the film, and exposing the exposed film to a concentration of less than 2.38% by mass. Developing with a certain aqueous solution of tetramethylammonium hydroxide.

Where
Xf each independently represents a fluorine atom or an alkyl group substituted with at least one fluorine atom.
R ₁ and R ₂ each independently represents a group selected from the group consisting of a hydrogen atom, a fluorine atom, an alkyl group, and an alkyl group substituted with at least one fluorine atom.
L each independently represents a single bond or a divalent linking group.
Cy each independently represents a group having a cyclic structure.
x represents the integer of 1-20 each independently.
y represents the integer of 0-10 each independently.
Each z independently represents an integer of 0 to 10.

[2] The pattern forming method according to [1], wherein the compound (B) generates an acid represented by the following general formula (LD1) or (LD2) by irradiation with an actinic ray or radiation.

Where
Xf each independently represents a fluorine atom or an alkyl group substituted with at least one fluorine atom.
R ₁ and R ₂ each independently represents a group selected from the group consisting of a hydrogen atom, a fluorine atom, an alkyl group, and an alkyl group substituted with at least one fluorine atom.
L each independently represents a single bond or a divalent linking group.
Cy each independently represents a group having a cyclic structure.
Rf represents a group containing a fluorine atom.
x represents the integer of 1-20 each independently.
y represents the integer of 0-10 each independently.
Each z independently represents an integer of 0 to 10.

  [3] The pattern forming method according to [2], wherein the compound (B) generates an acid represented by the general formula (LD1) by irradiation with an actinic ray or radiation.

  [4] The pattern forming method according to [2], wherein the compound (B) generates an acid represented by the general formula (LD2) upon irradiation with actinic rays or radiation.

[5] The pattern forming method according to [4], wherein the acid represented by the general formula (LD2) is represented by the following general formula (LD2I).

Where
Xf each independently represents a fluorine atom or an alkyl group substituted with at least one fluorine atom.
R ₁ and R ₂ each independently represents a group selected from the group consisting of a hydrogen atom, a fluorine atom, an alkyl group, and an alkyl group substituted with at least one fluorine atom.
L each independently represents a single bond or a divalent linking group.
Cy each independently represents a group having a cyclic structure.
x represents the integer of 1-20 each independently.
y represents the integer of 0-10 each independently.
Each z independently represents an integer of 0 to 10.

  [6] The pattern forming method according to any one of [1] to [5], wherein the resin (A) further includes a repeating unit having a lactone structure.

  [7] The pattern forming method according to any one of [1] to [6], wherein the resin (A) includes a repeating unit having a monocyclic or polycyclic acid-decomposable group.

  [8] The pattern forming method according to any one of [1] to [7], wherein the composition further contains a basic compound.

  [9] The pattern forming method according to any one of [1] to [8], wherein the composition further contains a surfactant.

  [10] The pattern forming method according to any one of [1] to [9], wherein the composition further contains a hydrophobic resin.

  [11] The pattern forming method according to any one of [1] to [10], wherein the exposure is immersion exposure.

  According to the present invention, it is possible to provide a pattern forming method excellent in exposure latitude (EL) and development defect performance.

Hereinafter, embodiments of the present invention will be described in detail.
Here, the groups and atomic groups that do not explicitly indicate substitution or non-substitution include both those that do not have a substituent and those that have a substituent. For example, an “alkyl group” that does not clearly indicate substitution or unsubstituted is not only an alkyl group that does not have a substituent (unsubstituted alkyl group) but also an alkyl group that has a substituent (substituted alkyl group) Is also included.

  The pattern forming method according to the present invention includes (1) forming a film using an actinic ray-sensitive or radiation-sensitive resin composition, (2) exposing the film, and (3) after exposure. And developing the film with an aqueous TMAH solution having a concentration of less than 2.38% by mass.

  First, the actinic ray-sensitive or radiation-sensitive resin composition that can be used in the pattern forming method according to the present invention will be described. This composition comprises (A) a resin whose solubility in an alkaline developer is increased by the action of an acid (hereinafter also referred to as an acid-decomposable resin or resin (A)), and (B) an acid upon irradiation with actinic rays or radiation. And a generated compound (hereinafter also referred to as an acid generator or a compound (B)). The compound (B) generates an acid having a specific partial structure by irradiation with actinic rays or radiation, as will be described in detail later.

(A) Acid-decomposable resin The composition that can be used in the pattern forming method according to the present invention contains an acid-decomposable resin. The acid-decomposable resin typically includes a group that decomposes by the action of an acid to generate an alkali-soluble group (hereinafter also referred to as an acid-decomposable group). This resin may have an acid-decomposable group in one of the main chain and the side chain, or in both of them. This resin is preferably insoluble or hardly soluble in an alkaline developer.

The acid-decomposable resin includes a repeating unit having an acid-decomposable group. The acid-decomposable group preferably has a structure in which an alkali-soluble group is protected with a group capable of decomposing and leaving by the action of an acid.
Alkali-soluble groups include phenolic hydroxyl groups, carboxy groups, fluorinated alcohol groups, sulfonic acid groups, sulfonamido groups, sulfonylimide groups, (alkylsulfonyl) (alkylcarbonyl) methylene groups, (alkylsulfonyl) (alkylcarbonyl) imides. Group, bis (alkylcarbonyl) methylene group, bis (alkylcarbonyl) imide group, bis (alkylsulfonyl) methylene group, bis (alkylsulfonyl) imide group, tris (alkylcarbonyl) methylene group, tris (alkylsulfonyl) methylene group, etc. Is mentioned.

  Preferred alkali-soluble groups include carboxy groups, fluorinated alcohol groups (preferably hexafluoroisopropanol), and sulfonic acid groups.

A preferable group as the acid-decomposable group is a group obtained by substituting the hydrogen atom of these alkali-soluble groups 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 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.

  The acid-decomposable group is preferably a cumyl ester group, an enol ester group, an acetal ester group, a tertiary alkyl ester group or the like. More preferably, it is a tertiary alkyl ester group.

The repeating unit having an acid-decomposable group that can be contained in the acid-decomposable resin is preferably a repeating unit represented by the following general formula (AI).

In general formula (AI),
Xa ₁ represents a hydrogen atom, a methyl group which may have a substituent, or a group represented by —CH ₂ —R ₉ . R ₉ represents a hydroxy group or a monovalent organic group, and examples thereof include an alkyl group having 5 or less carbon atoms and an acyl group, preferably an alkyl group having 3 or less carbon atoms, and more preferably a methyl group. . Xa ₁ preferably represents a hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl group.

T represents a single bond or a divalent linking group.
Rx _{1 to} Rx ₃ each independently represents an alkyl group (straight or branched) or a cycloalkyl group (monocyclic or polycyclic).
At least two of Rx _{1 to} Rx ₃ may combine to form a cycloalkyl group (monocyclic or polycyclic).

Examples of the divalent linking group for T include an alkylene group, —COO—Rt— group, —O—Rt— group, and the like. In the formula, Rt represents an alkylene group or a cycloalkylene group.
T is preferably a single bond or a —COO—Rt— group. Rt is preferably an alkylene group having 1 to 5 carbon atoms, more preferably a —CH ₂ — group or a — (CH ₂ ) ₃ — 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.

Examples of the cycloalkyl group represented by Rx _{1 to} Rx ₃ include monocyclic cycloalkyl groups such as cyclopentyl group and cyclohexyl group, polycyclic cycloalkyl groups such as norbornyl group, tetracyclodecanyl group, tetracyclododecanyl group, and adamantyl group. Groups are preferred.
Examples of the cycloalkyl group formed by combining at least two of Rx _{1 to} Rx ₃ include a monocyclic cycloalkyl group such as a cyclopentyl group and a cyclohexyl group, a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, A polycyclic cycloalkyl group such as an adamantyl group is preferred. A monocyclic cycloalkyl group having 5 to 6 carbon atoms is particularly preferable.
An embodiment in which Rx ₁ is a methyl group or an ethyl group, and Rx ₂ and Rx ₃ are combined to form the cycloalkyl group described above is preferred.

  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 carboxy group, An alkoxycarbonyl group (C2-C6) etc. are mentioned, C8 or less is preferable.

  The content of the repeating unit having an acid-decomposable group as a total is preferably 20 to 70 mol%, more preferably 30 to 50 mol%, based on all repeating units in the resin.

  Although the specific example of the repeating unit which has a preferable acid-decomposable group is shown below, this invention is not limited to this.

In specific examples, Rx and Xa ₁ represent a hydrogen atom, CH ₃ , CF ₃ , or CH ₂ OH. Rx
a and Rxb each represents an alkyl group having 1 to 4 carbon atoms. Z represents a substituent containing a polar group, and when there are a plurality of them, each is independent. p represents 0 or a positive integer.

The acid-decomposable resin is a resin having at least one of the repeating unit represented by the general formula (I) and the repeating unit represented by the general formula (II) as the repeating unit represented by the general formula (AI). More preferably.

In formulas (I) and (II)
R ₁ and R ₃ each independently represents a hydrogen atom, an optionally substituted methyl group or a group represented by —CH ₂ —R ₉ . R ₉ represents a monovalent organic group.
R ₂ , R ₄ , R ₅ and R ₆ each independently represents an alkyl group or a cycloalkyl group.
R represents an atomic group necessary for forming an alicyclic structure together with a carbon atom.

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

The alkyl group in R ₂ may be linear or branched, and may have a substituent.
The cycloalkyl group in R ₂ may be monocyclic or polycyclic and may have a substituent.
R ₂ is preferably an alkyl group, more preferably 1 to 10 carbon atoms, still more preferably 1 to 5 carbon atoms, and examples thereof include a methyl group and an ethyl group.

  R represents an atomic group necessary for forming an alicyclic structure together with a carbon atom. The alicyclic structure formed by R is preferably a monocyclic alicyclic structure, and the carbon number thereof is preferably 3 to 7, more preferably 5 or 6.

R ₃ is preferably a hydrogen atom or a methyl group, more preferably a methyl group.

The alkyl group in R ₄ , R ₅ and R ₆ may be linear or branched and may have a substituent. As the alkyl group, those having 1 to 4 carbon atoms such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group and t-butyl group are preferable.

The cycloalkyl group in R ₄ , R ₅ and R ₆ may be monocyclic or polycyclic and may have a substituent. The cycloalkyl group is preferably a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group, or a polycyclic cycloalkyl group such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group or an adamantyl group.

As a repeating unit represented by general formula (I), the repeating unit represented by the following general formula (1-a) is mentioned, for example.

In formula, R < ₁ > and R < ₂ > are synonymous with each in General formula (1).

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

In formula (II-1),
R < ₃ > -R < ₅ > is synonymous with the thing in general formula (II).

R ₁₀ represents a substituent containing a polar group. When a plurality of R ₁₀ are present, they may be the same as or different from each other. Examples of the substituent containing a polar group include a linear or branched alkyl group or cycloalkyl group having a hydroxyl group, a cyano group, an amino group, an alkylamide group or a sulfonamide group, and preferably a hydroxyl group. It is an alkyl group. As the branched alkyl group, an isopropyl group is particularly preferable.

  p represents an integer of 0 to 15. p is preferably 0 to 2, more preferably 0 or 1.

  The acid-decomposable resin is a resin containing at least one of the repeating unit represented by the general formula (I) and the repeating unit represented by the general formula (II) as the repeating unit represented by the general formula (AI). More preferably. In another embodiment, a resin containing at least two kinds of repeating units represented by the general formula (I) as the repeating unit represented by the general formula (AI) is more preferable.

In the case where the acid-decomposable resin contains a plurality of acid-decomposable repeating units, preferred combinations are as follows. In the following formula, each R independently represents a hydrogen atom or a methyl group.

The acid-decomposable resin preferably contains a repeating unit represented by the following general formula (1).

In general formula (1),
A represents an ester bond or an amide bond.
R ₀ independently represents an alkylene group, a cycloalkylene group, or a combination thereof when n _S ≧ 2.
Z is independently an ether bond, an ester bond, an amide bond, or a urethane bond when n _S ≧ 2.

Or urea bond

Represents. In the formula, R represents, for example, 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 _S represents an integer of 1 to 5. n _S is preferably 1.
R ₇ represents a hydrogen atom, an alkyl group or a halogen atom. This alkyl group may have a substituent. R ₇ preferably represents a hydrogen atom, a methyl group, a hydroxymethyl group or an acetoxymethyl group.

As described above, R ₀ represents an alkylene group, a cycloalkylene group, or a combination thereof.
The alkylene group as R ₀ may be linear or branched. The alkylene group preferably has 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms. Examples of such an alkylene group include a methylene group, an ethylene group, and a propylene group.

The cycloalkylene group as R ₀ preferably has 3 to 10 carbon atoms, and more preferably 5 to 7 carbon atoms. Examples of such a cycloalkylene group include a cyclopropylene group, a cyclobutylene group, a cyclopentylene group, and a cyclohexylene group.

  Each of these alkylene groups and cycloalkylene groups may have a substituent. Examples of the substituent include halogen atoms such as fluorine atom, chlorine atom and bromine atom; mercapto group; hydroxy group; alkoxy group of methoxy group, ethoxy group, isopropoxy group, t-butoxy group and benzyloxy group; Cycloalkyl groups such as propyl, cyclobutyl, cyclopentyl, cyclohexyl and cycloheptyl; cyano group; nitro group; sulfonyl group; silyl group; ester group; acyl group; vinyl group;

  Z represents an ether bond, an ester bond, an amide bond, a urethane bond or a urea bond as described above. Z is preferably an ether bond or an ester bond, and particularly preferably represents an ester bond.

R ₈ represents a monovalent organic group having a lactone structure as described above. This organic group has, for example, a lactone structure represented by any one of the following general formulas (LC1-1) to (LC1-17). Among these, the structure represented by general formula (LC1-4), (LC1-5) or (LC1-17) is more preferable, and the structure represented by general formula (LC1-4) is particularly preferable.

Wherein, Rb ₂ represents a substituent, _{n 2} represents an integer of 0-4. n ₂ is preferably an integer of 0 to 2.
Preferred examples of Rb ₂ include alkyl groups having 1 to 8 carbon atoms, cycloalkyl groups having 4 to 7 carbon atoms, alkoxy groups having 1 to 8 carbon atoms, alkoxycarbonyl groups having 1 to 8 carbon atoms, carboxy groups, and halogens. Examples thereof include an atom, a hydroxyl group, a cyano group, and an acid-decomposable group described later. Among these, an alkyl group having 1 to 4 carbon atoms, a cyano group, or an acid-decomposable group is particularly preferable. When n ₂ ≧ 2, the plurality of Rb ₂ may be the same as each other or different from each other. In addition, the plurality of Rb ₂ may be bonded to each other to form a ring.

R ₈ preferably has an unsubstituted lactone structure or a lactone structure having a methyl group, a cyano group, or an alkoxycarbonyl group as a substituent. In particular, R ₈ is preferably a monovalent organic group having a lactone structure having a cyano group as a substituent (that is, a cyanolactone structure).

Specific examples of the repeating unit represented by the general formula (1) are shown below. In the following specific examples, R represents a hydrogen atom, an alkyl group or a halogen atom. This alkyl group may have a substituent. R preferably represents a hydrogen atom, a methyl group, a hydroxymethyl group or an acetoxymethyl group.

The repeating unit represented by the general formula (1) is preferably a repeating unit represented by the following general formula (2).

In general formula (2),
R ₇ , A, R ₀ , Z and n _S have the same _meaning as in general formula (1).
Rb independently represents an alkyl group, a cycloalkyl group, an alkoxycarbonyl group, a cyano group, a hydroxyl group, or an alkoxy group when m ≧ 2. When m ≧ 2, two or more Rb may be bonded to each other to form a ring.
X represents an alkylene group, an oxygen atom, or a sulfur atom.
m 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 halogen atom such as a fluorine atom. Rb is more preferably a methyl group, a cyano group or an alkoxycarbonyl group, and even more preferably a cyano group.

  When m ≧ 1, it is preferable that at least one Rb is substituted at the α-position or β-position of the carbonyl group of the lactone. In particular, Rb is preferably substituted at the α-position of the lactone carbonyl 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.

Specific examples of the repeating unit represented by the general formula (2) are shown below. In the following specific examples, R represents a hydrogen atom, an alkyl group or a halogen atom. This alkyl group may have a substituent. R preferably represents a hydrogen atom, a methyl group, a hydroxymethyl group or an acetoxymethyl group.

  The repeating unit represented by the general formula (1) 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 is preferably 90% ee or more, and more preferably 95% ee or more.

In order to enhance the effect of the present invention, two or more lactone repeating units selected from general formula (1) can be used in combination. Of formulas (1) when used in combination, it is preferred that n _S to select a combination of two or more kinds of repeating units is 1.

  The content of the repeating unit represented by the general formula (1) is preferably 15 to 60 mol%, more preferably 20 to 50 mol%, based on all repeating units in the acid-decomposable resin, 30 More preferably, it is -50 mol%.

  The acid-decomposable resin may further contain another repeating unit having a lactone group in addition to the unit represented by the general formula (1) or (2).

  The other repeating unit having a lactone structure preferably has a 5- to 7-membered lactone structure, and forms another bicyclic structure or a spiro structure in the 5- to 7-membered lactone structure. More preferably, the ring is condensed.

  More specifically, a lactone structure represented by any one of the general formulas (LC1-1) to (LC1-17) can be given. Preferred lactone structures include (LC1-1), (LC1-4), (LC1-5), (LC1-6), (LC1-13), (LC1-14) and (LC1-17). . By using specific lactone structures, line edge roughness and development defects can be further reduced.

As another 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.

  V represents a group having a structure represented by any one of the general formulas (LC1-1) to (LC1-17).

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

Preferable examples of other repeating units having a lactone structure include the following repeating units. By selecting an optimal lactone group, for example, the pattern profile and / or density dependence can be optimized.

  The repeating unit having a lactone group usually has an optical isomer, but as described above, 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 is preferably 90% ee or more, and more preferably 95% ee or more.

  The content of the repeating unit having a lactone structure other than the repeating unit represented by the general formula (1) is preferably 15 to 60 mol%, more preferably 20 to 50 mol% with respect to all the repeating units in the resin. Preferably it is 30-50 mol%.

  The content of the repeating unit having a lactone structure other than the repeating unit represented by the general formula (1) is generally 50 mol% or less with respect to the repeating unit represented by the general formula (1), preferably 30 mol% or less.

The acid-decomposable resin preferably has a repeating unit having a hydroxyl group or a cyano group other than those represented by formulas (AI) and (1). 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 acid-decomposable resin.

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.

  The acid-decomposable resin may have a repeating unit having an alkali-soluble group. Examples of the alkali-soluble group include a carboxy 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, 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 an acid-decomposable resin, 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 acid-decomposable resin may further contain a repeating unit that has an alicyclic hydrocarbon structure having no polar group and does not exhibit acid-decomposability. Examples of such a repeating unit include a repeating unit represented by the general formula (IV).

In general formula (IV), 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. Ra is preferably a hydrogen atom, a methyl group, a hydroxymethyl group or a trifluoromethyl group, particularly preferably a hydrogen atom or a methyl 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. Preferable monocyclic hydrocarbon groups are monocyclic hydrocarbon groups having 3 to 7 carbon atoms, and more preferable examples include a cyclopentyl group and 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 that 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 having an alicyclic hydrocarbon structure having no polar group and not exhibiting acid decomposability is preferably 0 to 40 mol%, more preferably, based on all repeating units in the acid decomposable resin. 0 to 20 mol%.
Specific examples of the repeating unit having an alicyclic hydrocarbon structure having no polar group and not exhibiting acid decomposability are shown below, but the present invention is not limited thereto. In the formula, Ra represents H, CH ₃ , CH ₂ OH, or CF ₃ .

  In addition to the above repeating structural units, the acid-decomposable resin used in the composition of the present invention includes dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and resolution that is a general required characteristic of resist. It can have various repeating structural units for the purpose of adjusting heat resistance, sensitivity and the like.

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

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

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

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

  In the acid-decomposable resin used in the composition of the present invention, 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. It is appropriately set to adjust the resolving power, heat resistance, sensitivity and the like.

When the composition of the present invention is for ArF exposure, the acid-decomposable resin used in the composition of the present invention preferably has no aromatic group from the viewpoint of transparency to ArF light. The resin preferably has a monocyclic or polycyclic alicyclic hydrocarbon structure.
In addition, it is preferable that an acid-decomposable resin does not contain a fluorine atom and a silicon atom from a compatible viewpoint with the hydrophobic resin mentioned later.

  The acid-decomposable resin used in the composition of the present invention 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.

  In the case where the 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 acid-decomposable resin further has a hydroxystyrene-based repeating unit. It is preferable. 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.

  The acid-decomposable resin 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 carboxy group is preferable. Preferred initiators include azobisisobutyronitrile, azobisdimethylvaleronitrile, dimethyl 2,2′-azobis (2-methylpropionate) and the like. If desired, an initiator is added or added in portions, and after completion of the reaction, it is put into a solvent and a desired polymer is recovered by a method such as powder or solid recovery. The concentration of the reaction is 5 to 50% by mass, preferably 10 to 30% by mass. The reaction temperature is usually 10 ° C to 150 ° C, preferably 30 ° C to 120 ° C, more preferably 60-100 ° C.

  The weight average molecular weight of the acid-decomposable resin 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, developability is deteriorated, and viscosity is increased, resulting in deterioration of film forming property. Can be prevented.

  The dispersity (molecular weight distribution) is usually 1 to 3, preferably 1 to 2.6, more preferably 1 to 2, and 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 side wall of the resist pattern, the better the roughness.

In the present invention, the mixing ratio of the acid-decomposable resin in the entire composition is preferably 30 to 99% by mass, more preferably 60 to 95% by mass in the total solid content.
In addition, the resins of the present invention may be used alone or in combination. In addition, in the range which does not impair the effect of this invention, you may use together other resin other than the acid-decomposable resin mentioned above. Examples of the other resin include an acid-decomposable resin not containing the repeating unit represented by the general formula (1), or other known acid-decomposable resins.

(B) Acid generator The composition which can be used for the pattern formation method which concerns on this invention contains the acid generator. The acid generator generates an acid having a partial structure represented by the following general formula (LD) by irradiation with actinic rays or radiation. When such an acid generator is used, exposure latitude and development defect performance can be further improved. The reason for this is not always clear, but the present inventors speculate as follows. That is, the present inventors believe that an acid having a partial structure represented by the following general formula (LD) has a large molecular volume and a low diffusibility in the composition after exposure. .

Where
Xf each independently represents a fluorine atom or an alkyl group substituted with at least one fluorine atom.
R ₁ and R ₂ each independently represents a group selected from the group consisting of a hydrogen atom, a fluorine atom, an alkyl group, and an alkyl group substituted with at least one fluorine atom.
L each independently represents a single bond or a divalent linking group.
Cy each independently represents a group having a cyclic structure.
x represents the integer of 1-20 each independently.
y represents the integer of 0-10 each independently.
Each z independently represents an integer of 0 to 10.
Xf represents a fluorine atom or an alkyl group substituted with at least one fluorine atom. The alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 4 carbon atoms. The alkyl group substituted with at least one fluorine atom is preferably a perfluoroalkyl group.

Xf is preferably a fluorine atom or a perfluoroalkyl group having 1 to 4 carbon atoms. More specifically, Xf is a fluorine atom, CF ₃ , C ₂ F ₅ , C ₃ F ₇ , C ₄ F ₉ , C ₅ F ₁₁ , C ₆ F ₁₃ , C ₇ F ₁₅ , C ₈ F ₁₇ , _{CH 2 CF 3, CH 2 CH} 2 CF 3, CH 2 C 2 F 5, CH 2 CH 2 C 2 F 5, CH 2 C 3 F 7, CH 2 CH 2 C 3 F 7, CH 2 C 4 F 9 Or CH ₂ CH ₂ C ₄ F ₉ is preferred.

R ₁ and R ₂ are each independently a group selected from the group consisting of a hydrogen atom, a fluorine atom, an alkyl group, and an alkyl group substituted with at least one fluorine atom. The alkyl group and the alkyl group in the alkyl group substituted with at least one fluorine atom are preferably those having 1 to 4 carbon atoms. More preferably, it is a C1-C4 perfluoroalkyl group. Specifically, for example, CF ₃ , C ₂ F ₅ , C ₃ F ₇ , C ₄ F ₉ , C ₅ F ₁₁ , C ₆ F ₁₃ , C ₇ F ₁₅ , C ₈ F ₁₇ , CH ₂ CF ₃ , _{CH 2 CH 2 CF 3, CH} 2 C 2 F 5, CH 2 CH 2 C 2 F 5, CH 2 C 3 F 7, CH 2 CH 2 C 3 F 7, CH 2 C 4 F 9, and _CH 2 CH ₂ C ₄ F ₉ is mentioned, and CF ₃ is particularly preferable.

L represents a single bond or a divalent linking group. Examples of the divalent linking group include —COO—, —OCO—, —CO—, —O—, —S—, —SO—, —SO ₂ —, an alkylene group, a cycloalkylene group, and an alkenylene group. Is mentioned. Among these, —COO—, —OCO—, —CO—, —O—, or —SO ₂ — is preferable, and —COO—, —OCO—, or —SO ₂ — is more preferable.

  Cy represents a group having a cyclic structure. Examples of the group having a cyclic structure include an alicyclic group, an aryl group, and a group having a heterocyclic structure.

  The alicyclic group may be monocyclic or polycyclic. Examples of the monocyclic alicyclic group include monocyclic cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, and a cyclooctyl group. Examples of the polycyclic alicyclic group include polycyclic cycloalkyl groups such as a norbornyl group, a tricyclodecanyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, and an adamantyl group. Among them, an alicyclic group having a bulky structure having 7 or more carbon atoms, such as a norbornyl group, a tricyclodecanyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, and an adamantyl group, is a PEB (post-exposure heating) step. From the viewpoints of suppressing diffusibility in the film and improving MEEF (Mask Error Enhancement Factor).

  The aryl group may be monocyclic or polycyclic. Examples of the aryl group include a phenyl group, a naphthyl group, a phenanthryl group, and an anthryl group. Among these, a naphthyl group having a relatively low light absorbance at 193 nm is preferable.

  The group having a heterocyclic structure may be monocyclic or polycyclic, but the polycyclic can suppress acid diffusion more. Further, the group having a heterocyclic structure may have aromaticity or may not have aromaticity. Examples of the heterocyclic ring having aromaticity include a furan ring, a thiophene ring, a benzofuran ring, a benzothiophene ring, a dibenzofuran ring, a dibenzothiophene ring, and a pyridine ring. Examples of the heterocyclic ring not having aromaticity include a tetrahydropyran ring, a lactone ring, and a decahydroisoquinoline ring. As the heterocyclic ring in the group having a heterocyclic structure, a furan ring, a thiophene ring, a pyridine ring, or a decahydroisoquinoline ring is particularly preferable.

  The group having the cyclic structure may have a substituent. Examples of the substituent include an alkyl group, a cycloalkyl group, an aryl group, a hydroxy group, an alkoxy group, an ester group, an amide group, a urethane group, a ureido group, a thioether group, a sulfonamide group, and a sulfonic acid ester group. It is done. The alkyl group may be linear or branched. The alkyl group preferably has 1 to 12 carbon atoms. The cycloalkyl group may be monocyclic or polycyclic. The cycloalkyl group preferably has 3 to 12 carbon atoms. The aryl group preferably has 6 to 14 carbon atoms.

  x is preferably 1 to 8, more preferably 1 to 4, and particularly preferably 1. y is preferably 0 to 4, and more preferably 0. z is preferably 0 to 8, particularly preferably 0 to 4.

The acid having a partial structure represented by the general formula (LD) is preferably an acid represented by the following general formula (LD1). When an acid generator that generates an acid represented by the following general formula (LD1) by irradiation with actinic rays or radiation is used, the deprotection reaction is accelerated by increasing the acid strength, for example, improving the sensitivity. Is possible.

In general formula (LD1), Xf, R ₁ , R ₂ , L, Cy, x, y, and z have the same meanings as in general formula (LD).

The acid having a partial structure represented by the general formula (LD) is preferably an acid represented by the following general formula (LD2). When an acid generator that generates an acid represented by the following general formula (LD2) by irradiation with actinic rays or radiation is used, the acid strength is further increased to accelerate the deprotection reaction. Further improvement is possible.

In General Formula (LD2), Xf, R ₁ , R ₂ , L, Cy, x, y, and z have the same meanings as in General Formula (LD). Rf is a group containing a fluorine atom.

Examples of the group containing a fluorine atom represented by Rf include an alkyl group having at least one fluorine atom, a cycloalkyl group having at least one fluorine atom, and an aryl group having at least one fluorine atom. .
These alkyl group, cycloalkyl group and aryl group may be substituted with a fluorine atom, or may be substituted with another substituent containing a fluorine atom. When Rf is a cycloalkyl group having at least one fluorine atom or an aryl group having at least one fluorine atom, other substituents containing a fluorine atom include, for example, alkyl substituted with at least one fluorine atom. Groups.
Further, these alkyl group, cycloalkyl group and aryl group may be further substituted with a substituent not containing a fluorine atom. As this substituent, the thing which does not contain a fluorine atom among what was demonstrated about Cy previously can be mentioned, for example.

  Examples of the alkyl group having at least one fluorine atom represented by Rf include those described above as the alkyl group substituted with at least one fluorine atom represented by Xf. Examples of the cycloalkyl group having at least one fluorine atom represented by Rf include a perfluorocyclopentyl group and a perfluorocyclohexyl group. Examples of the aryl group having at least one fluorine atom represented by Rf include a perfluorophenyl group.

Rf is more preferably a corresponding group in the following general formula (LD2I). That is, the acid represented by the general formula (LD2) is more preferably represented by the following general formula (LD2I). When an acid generator that generates an acid represented by the following general formula (LD2I) by irradiation with actinic rays or radiation is used, the acid diffusibility is further reduced, and for example, the exposure latitude can be further improved. Become.

In general formula (LD2I), Xf, R ₁ , R ₂ , L, Cy, Rf, x, y, and z have the same meanings as in general formulas (LD) and (LD2).

Specific examples of the acid having a partial structure represented by the general formula (LD) are shown below.

  Examples of such an acid generator include diazonium salts, phosphonium salts, sulfonium salts, iodonium salts, imide sulfonates, oxime sulfonates, diazodisulfones, disulfones, and o-nitrobenzyl sulfonates.

  Moreover, the group which generate | occur | produces an acid by irradiation of these actinic rays or radiation, or the compound which introduce | transduced the compound into the principal chain or side chain of the polymer can be used.

The acid generator typically contains an anion having a partial structure represented by the general formula (LD).
An anion having a partial structure represented by the general formula (LD) is typically a non-nucleophilic 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. When an acid generator containing such an anion is used, the temporal stability of the resist is further improved.

  Examples of the anion having a partial structure represented by the general formula (LD) include a sulfonate anion, a carboxylate anion, a sulfonylimide anion, a bis (alkylsulfonyl) imide anion, and a tris (alkylsulfonyl) methyl anion. Can be mentioned.

  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), carboxy 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), aryl An oxysulfonyl group (preferably having 6 to 20 carbon atoms), an alkylaryloxysulfonyl group (preferably having 7 to 20 carbon atoms), a cycloalkylaryloxysulfonyl group (preferably having 10 to 20 carbon atoms), an alkyloxyalkyloxy group ( Preferable examples include 5 to 20 carbon atoms, a cycloalkylalkyloxyalkyloxy group (preferably 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 anion having a partial structure represented by the general formula (LD) include an aliphatic sulfonate anion in which the α-position of the sulfonic acid is substituted with a fluorine atom, a fragrance substituted with a fluorine atom or a group having a fluorine atom. Preferred are an aromatic sulfonate anion, a bis (alkylsulfonyl) imide anion in which an alkyl group is substituted with a fluorine atom, and a tris (alkylsulfonyl) methide anion in which an alkyl group is substituted with a fluorine atom. 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.

The acid generator preferably contains an anion formed by removing a hydrogen atom from the acid represented by the general formula (LD1), (LD2) or (LD2I). That is, the acid generator preferably contains an anion represented by the following general formula (LD1-A), (LD2-A) or (LD2I-A).

In general formula (LD1-A), Xf, R ₁ , R ₂ , L, Cy, x, y, and z have the same meanings as in general formulas (LD) and (LD1).

In General Formula (LD2-A), Xf, R ₁ , R ₂ , L, Cy, Rf, x, y, and z have the same meanings as those in General Formula (LD2).

In General Formula (LD2I-A), Xf, R ₁ , R ₂ , L, Cy, x, y, and z have the same meanings as those in General Formula (LD2I).

The acid generator is preferably a compound represented by the following general formula (ZI) or (ZII).

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 an anion having a partial structure represented by the general formula (LD).

Examples of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ include a compound (ZI-1) described later.
), (ZI-2), (ZI-3) and (ZI-4).

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 preferred (ZI) components include compounds (ZI-1), (ZI-2), (ZI-3) and (ZI-4) 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 R ₂₀₁
Some of to R ₂₀₃ is an aryl group and the remainder may be 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 heterocyclic structure include pyrrole, furan, thiophene, indole, benzofuran, 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, a halogen atom or a phenylthio group.
R _6c and R _7c each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group or an aryl group.
R _x and R _y each independently represents an alkyl group, a cycloalkyl group, a 2-oxoalkyl group, a 2-oxocycloalkyl group, an alkoxycarbonylalkyl 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 ^- is in the general formula (ZI) Z ^- synonymous.

The alkyl group as R _{1c to} R _7c may be either linear or branched, for example, an alkyl group having 1 to 20 carbon atoms, preferably a linear or branched alkyl group having 1 to 12 carbon atoms ( 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.

The aryl group as R _6c and R _7c preferably has 5 to 15 carbon atoms, and examples thereof include a phenyl group and a naphthyl group.

When R _6c and R _7c are combined to form a ring, the group formed by combining R _6c and R _7c is preferably an alkylene group having 2 to 10 carbon atoms, such as ethylene group, propylene Group, butylene group, pentylene group, hexylene group and the like. The ring formed by combining R _6c and R _7c may have a hetero atom such as an oxygen atom in the ring.

_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 .

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 alkoxycarbonylalkyl group include the same alkoxy groups as in R _{1c to} R _5c , and examples of the alkyl group include an alkyl group having 1 to 12 carbon atoms, preferably 1 to 1 carbon atom. 5 straight chain (for example, methyl group and ethyl group).

  The allyl group is not particularly limited, but is preferably an allyl group which is unsubstituted or substituted with a monocyclic or polycyclic cycloalkyl group.

  Although there is no restriction | limiting in particular as a vinyl group, It is preferable that it is a vinyl group substituted by the unsubstituted or monocyclic or polycyclic cycloalkyl group.

As the ring structure that R _x and R _y may be bonded to each other, divalent R _x and R _y (for example, a methylene group, an ethylene group, a propylene group, and the like) are represented by the general formula (ZI-3). A 5-membered or 6-membered ring formed with a sulfur atom, particularly preferably a 5-membered ring (that is, a tetrahydrothiophene ring).

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.

Specific examples of the cation moiety of compound (ZI-3) are shown below.

The compound (ZI-4) is a compound represented by the following general formula (ZI-4).

In general formula (ZI-4),
R ₁₃ represents a hydrogen atom, a fluorine atom, a hydroxyl group, an alkyl group, a cycloalkyl group, an alkoxy group, an alkoxycarbonyl group, or a group having a monocyclic or polycyclic cycloalkyl skeleton. These groups may have a substituent.
When there are a plurality of R _{14 s,} each independently represents an alkyl group, a cycloalkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylsulfonyl group, a cycloalkylsulfonyl group, or a monocyclic or polycyclic cycloalkyl skeleton. Represents a group having These groups may have a substituent.
R ₁₅ each independently represents an alkyl group, a cycloalkyl group or a naphthyl group. Two R ₁₅ may be bonded to each other to form a ring. These groups may have a substituent.
l represents an integer of 0-2.
r represents an integer of 0 to 8.
Z ^- is, in the general formula (ZI) Z ^- synonymous.

In the general formula (ZI-4), the alkyl group of R ₁₃ , R ₁₄ and R ₁₅ is linear or branched and preferably has 1 to 10 carbon atoms, and is preferably a methyl group, an ethyl group, n -Propyl group, i-propyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, t-butyl group, n-pentyl group, neopentyl group, n-hexyl group, n-heptyl group, n -An octyl group, 2-ethylhexyl group, n-nonyl group, n-decyl group etc. can be mentioned. Of these alkyl groups, a methyl group, an ethyl group, an n-butyl group, a t-butyl group, and the like are preferable.

Examples of the cycloalkyl group represented by R ₁₃ , R ₁₄ and R ₁₅ include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclododecanyl, cyclopentenyl, cyclohexenyl, cyclooctadienyl, norbornyl, tricyclo Examples include decanyl, tetracyclodecanyl, adamantyl and the like, and cyclopropyl, cyclopentyl, cyclohexyl and cyclooctyl are particularly preferable.

The alkoxy group of R ₁₃ and R ₁₄ is linear or branched and preferably has 1 to 10 carbon atoms, such as methoxy group, ethoxy group, n-propoxy group, i-propoxy group, n -Butoxy group, 2-methylpropoxy group, 1-methylpropoxy group, t-butoxy group, n-pentyloxy group, neopentyloxy group, n-hexyloxy group, n-heptyloxy group, n-octyloxy group, 2-ethylhexyloxy group, n-nonyloxy group, n-decyloxy group and the like can be mentioned. Of these alkoxy groups, a methoxy group, an ethoxy group, an n-propoxy group, an n-butoxy group, and the like are preferable.

The alkoxycarbonyl group for R ₁₃ and R ₁₄ is linear or branched and preferably has 2 to 11 carbon atoms, such as a methoxycarbonyl group, an ethoxycarbonyl group, an n-propoxycarbonyl group, i- Propoxycarbonyl group, n-butoxycarbonyl group, 2-methylpropoxycarbonyl group, 1-methylpropoxycarbonyl group, t-butoxycarbonyl group, n-pentyloxycarbonyl group, neopentyloxycarbonyl group, n-hexyloxycarbonyl group, Examples include n-heptyloxycarbonyl group, n-octyloxycarbonyl group, 2-ethylhexyloxycarbonyl group, n-nonyloxycarbonyl group, n-decyloxycarbonyl group and the like. Of these alkoxycarbonyl groups, a methoxycarbonyl group, an ethoxycarbonyl group, an n-butoxycarbonyl group, and the like are preferable.

Examples of the group having a monocyclic or polycyclic cycloalkyl skeleton of R ₁₃ and R ₁₄ include a monocyclic or polycyclic cycloalkyloxy group and an alkoxy group having a monocyclic or polycyclic cycloalkyl group. Can be mentioned. These groups may further have a substituent.

The monocyclic or polycyclic cycloalkyloxy group for R ₁₃ and R ₁₄ preferably has a total carbon number of 7 or more, more preferably a total carbon number of 7 or more and 15 or less, It is preferable to have a cycloalkyl skeleton. The monocyclic cycloalkyloxy group having 7 or more carbon atoms is cyclopropyloxy group, cyclobutyloxy group, cyclopentyloxy group, cyclohexyloxy group, cycloptyloxy group, cyclooctyloxy group, cyclododecanyloxy group, etc. Optionally substituted with methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, dodecyl, 2-ethylhexyl, isopropyl, sec-butyl, t -Alkyl group such as butyl group, iso-amyl group, hydroxyl group, halogen atom (fluorine, chlorine, bromine, iodine), nitro group, cyano group, amide group, sulfonamido group, methoxy group, ethoxy group, hydroxyethoxy group, Alkoxy groups such as propoxy group, hydroxypropoxy group, butoxy group, methoxy group Monocyclic cycloalkyloxy groups having substituents such as alkoxycarbonyl groups such as rubonyl groups, ethoxycarbonyl groups, acyl groups such as formyl groups, acetyl groups and benzoyl groups, acyloxy groups such as acetoxy groups and butyryloxy groups, and carboxy groups And the total number of carbon atoms combined with an arbitrary substituent on the cycloalkyl group is 7 or more.

  Examples of the polycyclic cycloalkyloxy group having a total carbon number of 7 or more include a norbornyloxy group, a tricyclodecanyloxy group, a tetracyclodecanyloxy group, an adamantantyloxy group, and the like.

The alkoxy group having a monocyclic or polycyclic cycloalkyl skeleton of R ₁₃ and R ₁₄ preferably has a total carbon number of 7 or more, more preferably a total carbon number of 7 or more and 15 or less, An alkoxy group having a monocyclic cycloalkyl skeleton is preferable. The alkoxy group having a total of 7 or more carbon atoms and having a monocyclic cycloalkyl skeleton is methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, heptoxy, octyloxy, dodecyloxy, 2-ethylhexyloxy, isopropoxy, A monocyclic cycloalkyl group that may have the above-mentioned substituents is substituted on an alkoxy group such as sec-butoxy, t-butoxy, iso-amyloxy, etc., and the total carbon number including the substituents is 7 or more Represents things. Examples thereof include a cyclohexylmethoxy group, a cyclopentylethoxy group, a cyclohexylethoxy group, and the like, and a cyclohexylmethoxy group is preferable.

  Examples of the alkoxy group having a polycyclic cycloalkyl skeleton having 7 or more carbon atoms include norbornyl methoxy group, norbornyl ethoxy group, tricyclodecanyl methoxy group, tricyclodecanyl ethoxy group, tetracyclo A decanyl methoxy group, a tetracyclodecanyl ethoxy group, an adamantane methoxy group, an adamantane ethoxy group, etc. are mentioned, and a norbornyl methoxy group, a norbornyl ethoxy group, etc. are preferable.

The alkyl group of the alkyl group of R ^14, include the same specific examples as the alkyl group as R ₁₃ to R ₁₅ described above.

The alkylsulfonyl group and cycloalkylsulfonyl group of R ₁₄ are linear, branched, or cyclic, and preferably those having 1 to 10 carbon atoms, such as methanesulfonyl group, ethanesulfonyl group, n-propanesulfonyl. Group, n-butanesulfonyl group, tert-butanesulfonyl group, n-pentanesulfonyl group, neopentanesulfonyl group, n-hexanesulfonyl group, n-heptanesulfonyl group, n-octanesulfonyl group, 2-ethylhexanesulfonyl group n -Nonanesulfonyl group, n-decanesulfonyl group, cyclopentanesulfonyl group, cyclohexanesulfonyl group, etc. can be mentioned. Of these alkylsulfonyl groups and cycloalkylsulfonyl groups, a methanesulfonyl group, an ethanesulfonyl group, an n-propanesulfonyl group, an n-butanesulfonyl group, a cyclopentanesulfonyl group, a cyclohexanesulfonyl group, and the like are preferable.

  Examples of the substituent that each of the above groups may have include a halogen atom (for example, a fluorine atom), a hydroxyl group, a carboxy group, a cyano group, a nitro group, an alkoxy group, an alkoxyalkyl group, an alkoxycarbonyl group, and alkoxycarbonyloxy. Groups and the like.

  Examples of the alkoxy group include methoxy group, ethoxy group, n-propoxy group, i-propoxy group, n-butoxy group, 2-methylpropoxy group, 1-methylpropoxy group, t-butoxy group, cyclopentyloxy group, Examples thereof include a linear, branched or cyclic alkoxy group having 1 to 20 carbon atoms such as a cyclohexyloxy group.

  Examples of the alkoxyalkyl group include straight chain having 2 to 21 carbon atoms such as methoxymethyl group, ethoxymethyl group, 1-methoxyethyl group, 2-methoxyethyl group, 1-ethoxyethyl group, and 2-ethoxyethyl group. Examples thereof include a chain, branched or cyclic alkoxyalkyl group.

  Examples of the alkoxycarbonyl group include methoxycarbonyl group, ethoxycarbonyl group, n-propoxycarbonyl group, i-propoxycarbonyl group, n-butoxycarbonyl group, 2-methylpropoxycarbonyl group, 1-methylpropoxycarbonyl group, t Examples thereof include linear, branched or cyclic alkoxycarbonyl groups having 2 to 21 carbon atoms such as butoxycarbonyl group, cyclopentyloxycarbonyl group, cyclohexyloxycarbonyl and the like.

  Examples of the alkoxycarbonyloxy group include a methoxycarbonyloxy group, an ethoxycarbonyloxy group, an n-propoxycarbonyloxy group, an i-propoxycarbonyloxy group, an n-butoxycarbonyloxy group, a t-butoxycarbonyloxy group, and a cyclopentyloxy group. Examples thereof include linear, branched or cyclic alkoxycarbonyloxy groups having 2 to 21 carbon atoms such as carbonyloxy group and cyclohexyloxycarbonyloxy.

The ring structure which two R ₁₅ may combine with each other is a 5-membered or 6-membered ring formed by two divalent R ₁₅ together with the sulfur atom in the general formula (ZI-4). Particularly preferred is a 5-membered ring (that is, a tetrahydrothiophene ring), which may be condensed with an aryl group or a cycloalkyl group. The divalent R ₁₅ may have a substituent. Examples of the substituent include a hydroxyl group, a carboxy group, a cyano group, a nitro group, an alkoxy group, an alkoxyalkyl group, an alkoxycarbonyl group, an alkoxycarbonyloxy group, and the like. Groups and the like. R ₁₅ in the general formula (ZI-4) is preferably a methyl group, an ethyl group, a naphthyl group, a divalent group in which two R ^15s are bonded to each other to form a tetrahydrothiophene ring structure together with a sulfur atom.

The substituent that R ₁₃ and R ₁₄ may have is preferably a hydroxyl group, an alkoxy group, an alkoxycarbonyl group, or a halogen atom (particularly a fluorine atom).

l is preferably 0 or 1, and more preferably 1.
As r, 0-2 are preferable.

Specific examples of the cation moiety of compound (ZI-4) are given below.

Next, the general formula (ZII) will be described.
In formula (ZII), R ₂₀₄ and R ₂₀₅ each independently represents an aryl group, an alkyl group or a cycloalkyl group.

The aryl group for R ₂₀₄ and R ₂₀₅ is preferably a phenyl group or a naphthyl group, 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 and 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 groups R ₂₀₄ and R _205, an alkyl group, a cycloalkyl group may have a substituent. Aryl groups R ₂₀₄ and R _205, an alkyl group, 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 ^- is, in the general formula (ZI) Z ^- synonymous.

The acid generator may be a compound represented by the following general formula (ZIII).

In General Formula (ZIII), R ₂₀₆ and R ₂₀₇ each independently represent an aryl group, an alkyl group, or a cycloalkyl group. At least one of R ₂₀₆ and R ₂₀₇ has a partial structure represented by the above general formula (LD).

The aryl group, alkyl group, and cycloalkyl group of R ₂₀₆ and R ₂₀₇ are the same as R ₂₀₄ in the general formula (ZII), except that the partial structure represented by the general formula (LD) is provided. And R ₂₀₅ are the same as those described above.

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

In general formula (ZIV), Ar ₃ and Ar ₄ each independently represents an aryl group. At least one of Ar ₃ and Ar ₄ has a partial structure represented by the general formula (LD).

In General Formula (ZV), R ₂₀₈ represents an alkyl group, a cycloalkyl group, or an aryl group, and has a partial structure represented by the above General Formula (LD). A represents an alkylene group, an alkenylene group or an arylene group.

In general formula (ZVI), R ₂₀₈ , R ₂₀₉ and R ₂₁₀ each independently represents an alkyl group, a cycloalkyl group or an aryl group. At least one of R ₂₀₈ , R ₂₀₉ and R ₂₁₀ has a partial structure represented by the general formula (LD).

  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 containing fluorinated acid, or a compound that generates a monovalent fluorine atom or imide acid substituted with a group containing a fluorine atom, and even more preferably, 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. When such a configuration is adopted, the sensitivity is further improved.

Among acid generators, particularly preferred examples are given below.

An acid generator can be used individually by 1 type or in combination of 2 or more types.
The content of the acid generator is preferably 0.1 to 30% by mass, more preferably 0.5 to 25% by mass, still more preferably 3 to 20% by mass, particularly preferably based on the total solid content of the composition. Is 3 to 15% by mass.

  When the acid generator is represented by the general formula (ZI-3) or (ZI-4), the content is preferably 5 to 20% by mass based on the total solid content of the composition. 8-20 mass% is more preferable, 10-20 mass% is still more preferable, and 10-15 mass% is especially preferable.

  The composition that can be used in the pattern forming method according to the present invention further includes a hydrophobic resin, a solvent, a basic compound, a surfactant, a carboxylic acid onium salt, a dissolution inhibiting compound, and / or other additives. May be.

(Hydrophobic resin)
The composition that can be used in the pattern forming method according to the present invention may further contain a hydrophobic resin. By including the hydrophobic resin, the hydrophobic resin is unevenly distributed on the surface layer of the actinic ray-sensitive or radiation-sensitive resin film, and the receding contact angle of the film with respect to the immersion liquid can be improved when water is used as the immersion medium. It becomes possible. Thereby, the immersion liquid followability of a film | membrane can be improved.

The receding contact angle of the film after baking and before exposure is preferably 60 ° to 90 ° at a temperature of 23 ± 3 ° C. and a humidity of 45 ± 5%, more preferably 65 ° or more, still more preferably 70 ° or more, and particularly preferably. It is 75 ° or more.
The hydrophobic resin is unevenly distributed at the interface as described above, but unlike the surfactant, it does not necessarily have a hydrophilic group in the molecule and contributes to uniform mixing of polar / nonpolar substances. It is not necessary.

  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. The contact angle of the immersion liquid with respect to the film in the film becomes important, and the actinic ray-sensitive or radiation-sensitive resin composition is required to follow the high-speed scanning of the exposure head without leaving droplets.

The hydrophobic resin (HR) is preferably a resin having at least one of a fluorine atom and a silicon atom. 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. When the hydrophobic resin has at least one of a fluorine atom and a silicon atom, the hydrophobicity (water followability) of the film surface is improved and the development residue (scum) is reduced.
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 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.

Suitable examples of the repeating unit having a fluorine atom include those shown below.

In the formula, R ₁₀ and R ₁₁ are each independently a hydrogen atom, a fluorine atom, or an alkyl group (preferably a linear or branched alkyl group having 1 to 4 carbon atoms, and particularly as an alkyl group having a substituent, Fluorinated alkyl group can be mentioned).
W _{3 to} W ₆ each independently represents an organic group containing at least one fluorine atom. Specific examples include groups represented by the general formulas (F2) to (F4).
Moreover, you may have a unit as shown below as a repeating unit which has a fluorine atom besides these.

In the formula, R _{4 to} R ₇ are each independently a hydrogen atom, a fluorine atom, or an alkyl group (preferably a linear or branched alkyl group having 1 to 4 carbon atoms, and the alkyl group having a substituent is In particular, a fluorinated alkyl group can be mentioned).

However, at least one of R _{4 to} R ₇ represents a fluorine atom. R ₄ and R ₅ or R ₆ and R ₇ may form a ring.
W ₂ represents an organic group containing at least one fluorine atom. Specific examples include the atomic groups (F2) to (F4).

  Q represents an alicyclic structure. The alicyclic structure may have a substituent and may be monocyclic or polycyclic. In the case of a polycyclic type, a bridge type may be used. As the monocyclic type, a cycloalkyl group having 3 to 8 carbon atoms is preferable, and examples thereof include a cyclopentyl group, a cyclohexyl group, a cyclobutyl group, and a cyclooctyl group. Examples of the polycyclic type include groups having a bicyclo, tricyclo or tetracyclo structure having 5 or more carbon atoms, and a cycloalkyl group having 6 to 20 carbon atoms is preferable, for example, an adamantyl group, norbornyl group, dicyclopentyl group. , Tricyclodecanyl group, tetracyclododecyl group and the like. A part of carbon atoms in the cycloalkyl group may be substituted with a hetero atom such as an oxygen atom.

L ₂ represents a single bond or a divalent linking group. Examples of the divalent linking group include a substituted or unsubstituted arylene group, a substituted or unsubstituted alkylene group, a substituted or unsubstituted cycloalkylene group, —O—, —SO ₂ —, —CO—, —N (R )-(Wherein R represents a hydrogen atom or an alkyl group), —NHSO ₂ — or a divalent linking group formed by combining a plurality of these.
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 urea group is used alone or in combination of 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.
Specific examples of the repeating unit containing a fluorine atom or a silicon atom are shown below. In specific examples, X ₁ represents a hydrogen atom, —CH ₃ , —F or —CF ₃ , and X ₂ represents —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 repeating units 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 used at the time of polymerization to be introduced at the end of the polymer chain. 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 hydrophobic resin. .

Specific examples of the repeating unit having an alkali-soluble group (x) are shown below. In specific examples, Rx represents H, CH ₃ , CH ₂ OH, or CF ₃ .

  (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) that increases the solubility in an alkali developer is preferably 1 to 40 mol%, more preferably 3 to 30 mol%, based on all repeating units in the hydrophobic resin. Preferably it is 5-15 mol%.

  Specific examples of the repeating unit having a group (y) that increases the solubility in an alkali developer are the same as the repeating unit having a lactone structure in the acid-decomposable resin (that is, the above-described general formula (1) Or those exemplified as specific examples of the general formula (AII ′)).

  This lactone structure is preferably substituted with an atomic group having an electron withdrawing group such as a fluorine atom. In this way, the solubility in an alkali developer can be further improved.

For example, when the lactone structure is represented by any of the above (LC1-1) to (LC1-17), it is preferable that n ₂ ≧ 1 and at least one of Rb ₂ includes a fluorine atom. In this case, Rb ₂ is an alkyl group having 1 to 8 carbon atoms substituted with at least one fluorine atom, a cycloalkyl group having 4 to 7 carbon atoms substituted with at least one fluorine atom, or at least one fluorine atom. It is preferably a substituted alkoxy group having 1 to 8 carbon atoms, or an alkoxycarbonyl group having 1 to 8 carbon atoms substituted with at least one fluorine atom, and has 1 to 1 carbon atoms substituted with at least one fluorine atom. More preferably, it is an alkoxycarbonyl group of 8.

  Examples of the repeating unit having a group (z) that is decomposed by the action of an acid in the hydrophobic resin (HR) are the same as the repeating unit having an acid-decomposable group in the acid-decomposable resin described above.

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 based on all repeating units in the hydrophobic resin. It is 10-80 mol%, More preferably, it is 20-60 mol%.
The hydrophobic resin (HR) may further have a repeating unit represented by the following general formula (VI).

In general formula (VI):
R _c31 represents a hydrogen atom, an alkyl group _optionally substituted with fluorine, a cyano group, or a —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, a cycloalkenyl group or an aryl 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 (VI), 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.
The aryl group is preferably a phenyl group or naphthyl group having 6 to 20 carbon atoms, and these may have a substituent.

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 alkylene group (preferably having 1 to 5 carbon atoms), an oxy group, a phenylene group, or an ester bond (a group represented by —COO—).
The hydrophobic resin (HR) may contain a repeating unit represented by the following general formula (VII) or (VIII) as the repeating unit represented by the general formula (VI).

In general formula (VII), R _c5 represents a hydrocarbon group having at least one cyclic structure and having neither a hydroxyl group nor a cyano group.
Rac represents a hydrogen atom, an alkyl group which may be substituted with a fluorine atom, a cyano group or a —CH ₂ —O—Rac ₂ group. Wherein, Rac ₂ represents a hydrogen atom, an alkyl group or an acyl group. Rac is preferably a hydrogen atom, a methyl group, a hydroxymethyl group or a trifluoromethyl group, particularly preferably a hydrogen atom or a methyl group.

The cyclic structure possessed by R _c5 includes a monocyclic hydrocarbon group and a polycyclic hydrocarbon group. Examples of the monocyclic hydrocarbon group include a cycloalkyl group having 3 to 12 carbon atoms and a cycloalkenyl group having 3 to 12 carbon atoms. A preferable monocyclic hydrocarbon group is a monocyclic hydrocarbon group having 3 to 7 carbon atoms.

  The polycyclic hydrocarbon group includes a ring assembly hydrocarbon group and a bridged cyclic hydrocarbon group. Examples of the bridged cyclic hydrocarbon ring include a bicyclic hydrocarbon ring, a tricyclic hydrocarbon ring, and a tetracyclic hydrocarbon ring. The bridged cyclic hydrocarbon ring also includes a condensed cyclic hydrocarbon ring (for example, a condensed ring in which a plurality of 5- to 8-membered cycloalkane rings are condensed). Preferred 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 that 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.

In the general formula (VIII), R _c6 represents an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, an alkoxycarbonyl group, or an alkylcarbonyloxy group. These groups may be substituted with a fluorine atom or a silicon atom.
The alkyl group for R _c6 is preferably a linear or branched alkyl group having 1 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.
The alkoxycarbonyl group is preferably an alkoxycarbonyl group having 2 to 20 carbon atoms.

The alkylcarbonyloxy group is preferably an alkylcarbonyloxy group having 2 to 20 carbon atoms.
n represents an integer of 0 to 5. When n is 2 or more, the plurality of R _c6 may be the same or different.
R _c6 is preferably an unsubstituted alkyl group or an alkyl group substituted with a fluorine atom, particularly preferably a trifluoromethyl group or a t-butyl group.
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).
The general formula (CII-AB) is more preferably the following general formula (CII-AB1) or general formula (CII-AB2).

Wherein (CII-AB1) and _{(CII-AB2), Rc 13} '~Rc 16' each independently represent a hydrogen atom, a halogen atom, an alkyl group or a cycloalkyl group.
It is also possible to form at least two members to the ring of Rc _l3 '~Rc _16'.
n represents 0 or 1.
Specific examples of the repeating unit represented by the general formula (VI) or (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.

Specific examples of the hydrophobic resin (HR) are shown below. Table 1 below shows the molar ratio of the 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.

Other specific examples of the resin (HR) are shown below. The table below shows the molar ratio of repeating units in each resin (corresponding to each repeating unit in order from the left), weight average molecular weight (Mw), and dispersity (Mw / Mn).

Hydrophobic resins can be used alone or in combination of two or more.
When the hydrophobic resin has a fluorine atom, the fluorine atom content is preferably 5 to 80% by mass and more preferably 10 to 80% by mass with respect to the molecular weight of the resin (HR). Moreover, it is preferable that the repeating unit containing a fluorine atom is 10-100 mass% with respect to all the repeating units in resin (HR), and it is more preferable that it is 30-100 mass%.

When resin (HR) has a silicon atom, it is preferable that the content rate of a silicon atom is 2-50 mass% with respect to the molecular weight of resin (HR), and it is more preferable that it is 2-30 mass%. Moreover, it is preferable that the repeating unit containing a silicon atom is 10-90 mass% with respect to all the repeating units of resin (HR), and it is more preferable that it is 20-80 mass%.
The weight average molecular weight of the resin (HR) in terms of standard polystyrene is preferably 1,000 to 100,000, more preferably 1,000 to 50,000, and still more preferably 2,000 to 15,000.

  The dissolution rate of the hydrophobic resin in the alkaline developer is preferably 0.001 nm / sec or more, more preferably 0.01 nm / sec or more, still more preferably 0.1 nm / sec or more, and 1 nm. / Sec or more is most preferable.

  Here, the dissolution rate of the hydrophobic resin in the alkaline developer is such that the film thickness when the resin film is formed only with the hydrophobic resin with respect to the 23 ° C. TMAH aqueous solution (2.38 mass%). is there.

  The content of the resin (HR) in the actinic ray-sensitive or radiation-sensitive resin composition is preferably 0.01 to 10% by mass based on the total solid content of the actinic ray- or radiation-sensitive resin composition, More preferably, it is 0.1-9 mass%, More preferably, it is 0.5-8 mass%.

The film formed from the actinic ray-sensitive or radiation-sensitive resin composition of the present invention is filled with a liquid (immersion medium) having a higher refractive index than air between the film and the lens when irradiated with actinic rays or radiation. Exposure (immersion exposure) may be performed. 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 surface tension of the water is decreased and the surface activity is increased, so that the resist film on the wafer is not dissolved and the influence on the optical coating on the lower surface of the lens element can be ignored. 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.

  An immersion liquid poorly soluble film (hereinafter also referred to as “topcoat”) may be provided between the film of the composition of the present invention and the immersion liquid so that the film does not directly contact the immersion liquid. Good. The necessary functions for the top coat are suitability for application to the upper layer of the resist, radiation, especially transparency to 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 resist upper layer.

  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 above-mentioned hydrophobic resin (HR) (including hydrophobic resins (C) and (CP)) 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 low penetration into the film is preferable. In terms of being able to perform the peeling process simultaneously with the film development process, it is preferable that the peeling process can be performed with an alkaline developer. The top coat is preferably acidic from the viewpoint of peeling with an alkali developer, but may be neutral or alkaline from the viewpoint of non-intermixability with the 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 membrane and further not mixed with the immersion liquid. From this point of view, when the immersion liquid is water, the solvent used for the top coat is preferably a water-insoluble medium that is hardly soluble in the solvent used for the composition of the present invention. Furthermore, when the immersion liquid is an organic solvent, the topcoat may be water-soluble or water-insoluble.

(solvent)
The composition that can be used in the pattern forming method according to the present invention may further contain a solvent.
Examples of the solvent include alkylene glycol monoalkyl ether carboxylate, alkylene glycol monoalkyl ether, alkyl lactate ester, alkyl alkoxypropionate, cyclic lactone (preferably having 4 to 10 carbon atoms), and monoketone which may contain a ring. Examples thereof include organic solvents such as compounds (preferably having 4 to 10 carbon atoms), alkylene carbonate, alkyl alkoxyacetate, and alkyl pyruvate.

  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 Examples include ether propionate, ethylene glycol monomethyl ether acetate, and ethylene glycol monoethyl ether acetate.

  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.

  Examples of the alkyl lactate include methyl lactate, ethyl lactate, propyl lactate, and butyl lactate.

  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. And 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, and 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 and 3- And methylcycloheptanone.

  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.

  Examples of the alkyl pyruvate include methyl pyruvate, ethyl pyruvate, and propyl pyruvate.

  As the solvent, it is preferable to use a solvent having a boiling point of 130 ° C. or higher under normal temperature and pressure. Specifically, for example, cyclopentanone, γ-butyrolactone, cyclohexanone, ethyl lactate, ethylene glycol monoethyl ether acetate, PGMEA, ethyl 3-ethoxypropionate, ethyl pyruvate, 2-ethoxyethyl acetate, acetic acid-2 -(2-Ethoxyethoxy) ethyl and propylene carbonate are mentioned.

  These solvents may be used alone or in combination of two or more. In the latter case, it is preferable to use a mixed solvent of a solvent containing a hydroxyl group and a solvent not containing a hydroxyl group.

  Examples of the solvent containing a hydroxyl group include alkylene glycol monoalkyl ether and alkyl lactate. Of these, propylene glycol monomethyl ether or ethyl lactate is more preferable.

  As the solvent not containing a hydroxyl group, for example, alkylene glycol monoalkyl ether acetate, alkyl alkoxypropionate, a monoketone compound which may contain a ring, cyclic lactone and alkyl acetate are preferable. Of these, propylene glycol monomethyl ether acetate, ethyl ethoxypropionate, 2-heptanone, γ-butyrolactone, cyclohexanone or butyl acetate are more preferred, and propylene glycol monomethyl ether acetate, ethyl ethoxypropionate or 2-heptanone is particularly preferred. .

  When using a mixed solvent of a solvent containing a hydroxyl group and a solvent not containing a hydroxyl group, these mass ratios are preferably 1/99 to 99/1, more preferably 10/90 to 90/10, More preferably, it is set to 20/80 to 60/40.

  When a mixed solvent containing 50% by mass or more of a solvent not containing a hydroxyl group is used, particularly excellent coating uniformity can be achieved. The solvent is particularly preferably a mixed solvent of PGMEA and one or more other solvents.

  The solvent is preferably a mixed solvent of propylene glycol monomethyl ether acetate and at least one other solvent.

(Basic compound)
The composition that can be used in the pattern forming method according to the present invention may further contain a basic compound. 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 each independently represent a hydrogen atom, an alkyl group (preferably having 1 to 20 carbon atoms), a cycloalkyl group (preferably having 3 to 20 carbon atoms), or an aryl group (having 6 to 6 carbon atoms). 20). R ²⁰¹ and R ²⁰² may be bonded to each other to form a ring.
R ²⁰³ , R ²⁰⁴ , R ²⁰⁵ and R ²⁰⁶ each independently 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. These alkyl groups are more preferably unsubstituted.

  Preferred basic compounds include guanidine, aminopyrrolidine, pyrazole, pyrazoline, piperazine, aminomorpholine, aminoalkylmorpholine and piperidine. More preferable basic compounds include an imidazole structure, a diazabicyclo structure, an onium hydroxide structure, an onium carboxylate structure, a trialkylamine structure, an aniline structure or a pyridine structure, an alkylamine derivative having a hydroxyl group and / or an ether bond, And aniline derivatives 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.

  Examples of the compound having an onium hydroxide structure include tetrabutylammonium hydroxide, triarylsulfonium hydroxide, phenacylsulfonium hydroxide, and sulfonium hydroxide having a 2-oxoalkyl group. More specifically, triphenylsulfonium hydroxide, tris (t-butylphenyl) sulfonium hydroxide, bis (t-butylphenyl) iodonium hydroxide, phenacylthiophenium hydroxide and 2-oxopropylthiophenium hydroxy Do.

  Examples of the compound having an onium carboxylate structure include a compound having an onium hydroxide structure having a carboxylate as an anion. Examples of the carboxylate include acetate, adamantane-1-carboxylate, and perfluoroalkylcarboxylate.

  Examples of the compound having a trialkylamine structure include tri (n-butyl) amine and tri (n-octyl) amine.

  Examples of aniline compounds include 2,6-diisopropylaniline, N, N-dimethylaniline, N, N-dibutylaniline, and N, N-dihexylaniline.

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.

In these compounds, it is preferable that at least one alkyl group is bonded to a nitrogen atom. Further, it is more preferable that an oxygen atom is contained in the chain of the alkyl group to form an oxyalkylene group. The number of oxyalkylene groups is preferably one or more in the molecule, more preferably 3 to 9, and still more preferably 4 to 6. Of these oxyalkylene _{groups, -CH 2 CH 2 O -,} - CH (CH 3) CH 2 O- or _-CH 2 _CH 2 _CH 2 O- by a group represented are especially preferred.

  Specific examples of these compounds include compounds (C1-1) to (C3-3) exemplified in [0066] of US2007 / 0224539A.

  The total amount of the basic compound is preferably 0.001 to 10% by mass, more preferably 0.01 to 5% by mass, based on the total solid content of the composition.

  The molar ratio of the total amount of the acid generator to the total amount of the basic compound is preferably 2.5 to 300, more preferably 5.0 to 200, and still more preferably 7.0 to 150. If this molar ratio is too small, sensitivity and / or resolution may be reduced. If this molar ratio is excessively large, pattern thickening may occur between exposure and heating (post-bake).

(Surfactant)
The composition that can be used in the pattern forming method according to the present invention may further contain a surfactant. By containing a surfactant, when an exposure light source having a wavelength of 250 nm or less, particularly 220 nm or less, is used, it is possible to form a pattern with less adhesion and development defects with good sensitivity and resolution. Become.

As the surfactant, it is particularly preferable to use a fluorine-based and / or silicon-based surfactant.
Examples of the fluorine-based and / or silicon-based surfactant include surfactants described in [0276] of US Patent Application Publication No. 2008/0248425. Also, F-top EF301 or EF303 (manufactured by Shin-Akita Kasei Co., Ltd.); Florard FC430, 431 or 4430 (manufactured by Sumitomo 3M Co., Ltd.); Megafac F171, F173, F176, F189, F113, F110, F177, F120 or R08 (Dainippon Ink Chemical Co., Ltd.); Surflon S-382, SC101, 102, 103, 104, 105 or 106 (Asahi Glass Co., Ltd.); Troisol S-366 (Troy Chemical Co., Ltd.); GF-300 or GF-150 (manufactured by Toa Gosei Chemical Co., Ltd.), Surflon S-393 (manufactured by Seimi Chemical Co., Ltd.); F-top EF121, EF122A, EF122B, RF122C, EF125M, EF135M, EF351, EF352, EF801, EF802 or F601 (manufactured by Gemco); PF636, PF656, PF6320 or PF6520 (manufactured by OMNOVA); or FTX-204G, 208G, 218G, 230G, 204D, 208D, 212D, 218D or 222D (manufactured by Neos) May be used. Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) can also be used as a silicon-based surfactant.

  In addition to known surfactants as described above, the surfactant is a fluoroaliphatic compound produced by a telomerization method (also referred to as a telomer method) or an oligomerization method (also referred to as an oligomer method). You may synthesize. Specifically, a polymer having a fluoroaliphatic group derived from this fluoroaliphatic compound may be used as a surfactant. This fluoroaliphatic compound can be synthesized, for example, by the method described in JP-A-2002-90991.

  The polymer having a fluoroaliphatic group is preferably a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate or methacrylate and / or (poly (oxyalkylene)) methacrylate. Even if it distributes, block copolymerization may be sufficient.

  Examples of the poly (oxyalkylene) group include a poly (oxyethylene) group, a poly (oxypropylene) group, and a poly (oxybutylene) group. In addition, units having different chain length alkylene in the same chain, such as poly (block connection body of oxyethylene, oxypropylene, and oxyethylene) and poly (block connection body of oxyethylene and oxypropylene) Also good.

  Further, a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate or methacrylate has a monomer having two or more different fluoroaliphatic groups and two or more different (poly (oxyalkylene). )) It may be a ternary or higher copolymer obtained by copolymerizing acrylate or methacrylate simultaneously.

For example, Megafac F178, F-470, F-473, F-475, F-476 and F-472 (Dainippon Ink Chemical Co., Ltd.) are mentioned as commercially available surfactants. Further, a copolymer of an acrylate or methacrylate having a C ₆ F ₁₃ group and (poly (oxyalkylene)) acrylate or methacrylate, an acrylate or methacrylate having a C ₆ F ₁₃ group and (poly (oxyethylene)) acrylate or methacrylate And a copolymer of (poly (oxypropylene)) acrylate or methacrylate, a copolymer of an acrylate or methacrylate having a C ₈ F ₁₇ group and (poly (oxyalkylene)) acrylate or methacrylate, and C ₈ F ₁₇ And a copolymer of an acrylate or methacrylate having a group and (poly (oxyethylene)) acrylate or methacrylate and (poly (oxypropylene)) acrylate or methacrylate. That.

  Further, surfactants other than fluorine-based and / or silicon-based surfactants described in [0280] of US Patent Application Publication No. 2008/0248425 may be used.

One of these surfactants may be used alone, or two or more thereof may be used in combination.
When the composition usable for the pattern forming method according to the present invention contains a surfactant, the content thereof is preferably 0 to 2% by mass, more preferably 0, based on the total solid content of the composition. 0.0001 to 2% by mass, and more preferably 0.0005 to 1% by mass.

(Carboxylic acid onium salt)
The composition that can be used in the pattern forming method according to the present invention may further contain a carboxylic acid onium salt. When carboxylic acid onium salt is contained, transparency to light having a wavelength of 220 nm or less is ensured, sensitivity and resolution are further improved, and density dependency and exposure margin are further improved.

  As the carboxylic acid onium salt, an iodonium salt or a sulfonium salt is preferable. As the anion, for example, a linear or branched alkyl having 1 to 30 carbon atoms or a monocyclic or polycyclic cycloalkylcarboxylic acid anion is preferably used. In particular, a carboxylate anion in which some or all of the hydrogen atoms of these alkyl groups or cycloalkyl groups are substituted with fluorine atoms (hereinafter also referred to as fluorine-substituted carboxylate anions) is preferable. Note that an oxygen atom may be contained in the alkyl or cycloalkyl chain.

  Examples of the fluorine-substituted carboxylate anion include fluoroacetic acid, difluoroacetic acid, trifluoroacetic acid, pentafluoropropionic acid, heptafluorobutyric acid, nonafluoropentanoic acid, perfluorododecanoic acid, perfluorotridecanoic acid, perfluorocyclohexanecarboxylic acid, and 2 , 2-bistrifluoromethylpropionic acid anion.

  When the composition that can be used in the pattern forming method according to the present invention contains a carboxylic acid onium salt, the content is generally 0.1 to 20% by mass based on the total solid content of the composition. Preferably, it is 0.5-10 mass%, More preferably, it is 1-7 mass%.

(Dissolution inhibitor compound)
The composition that can be used in the pattern forming method according to the present invention may further contain a dissolution inhibiting compound. Here, the “dissolution inhibiting compound” is a compound having a molecular weight of 3000 or less, which decomposes by the action of an acid and increases the solubility in an alkaline developer.

  As this dissolution inhibiting compound, since it does not decrease the transmittance for light having a wavelength of 220 nm or less, acid decomposition such as a cholic acid derivative containing an acid-decomposable group described in Proceeding of SPIE, 2724, 355 (1996) An alicyclic or aliphatic compound containing a functional group is preferred. Examples of the acid-decomposable group and the alicyclic structure include the same ones as described above.

  When the composition that can be used in the pattern forming method according to the present invention is exposed with a KrF excimer laser or irradiated with an electron beam, as the dissolution inhibiting compound, the phenolic hydroxyl group of the phenol compound is an acid-decomposable group. Compounds containing a substituted structure are preferred. As a phenol compound, what contains 1-9 phenol frame | skeleton is preferable, and what contains 2-6 pieces is still more preferable.

  When the composition that can be used in the pattern forming method according to the present invention contains a dissolution inhibiting compound, the content thereof is preferably 3 to 50% by mass, more preferably, based on the total solid content of the composition. Is 5-40 mass%.

Specific examples of the dissolution inhibiting compound are given below.

(Other additives)
The composition that can be used in the pattern forming method according to the present invention includes, if necessary, a compound (for example, molecular weight) that promotes solubility in dyes, plasticizers, photosensitizers, light absorbers, and / or developers. 1000 or less phenol compounds, or alicyclic or aliphatic compounds containing a carboxy group) may further be included.

  For example, phenol compounds having a molecular weight of 1000 or less can be easily obtained with reference to the methods described in JP-A-4-1222938, JP-A-2-28531, US Pat. No. 4,916,210, European Patent 219294, and the like. Can be synthesized.

  Examples of alicyclic or aliphatic compounds containing a carboxy group include carboxylic acid derivatives containing steroid structures such as cholic acid, deoxycholic acid and lithocholic acid, adamantane carboxylic acid derivatives, adamantane dicarboxylic acid, cyclohexane carboxylic acid, And cyclohexanedicarboxylic acid.

Next, the pattern forming method according to the present invention will be described in detail.
In this pattern formation method, as described above, (1) a film is formed using an actinic ray-sensitive or radiation-sensitive resin composition, (2) the film is exposed, and (3) after exposure. And developing with a TMAH aqueous solution having a concentration of less than 2.38% by mass. Hereinafter, these steps will be described in order.

<Step (1): Formation of film>
When forming a film | membrane using said composition, it is preferable that the film thickness of this film | membrane is 30-250 nm, and it is more preferable that it is 30-200 nm. In this way, the resolution can be further improved. A film having such a film thickness can be formed by adjusting the viscosity by setting the solid content concentration in the composition to an appropriate range and improving the coating property and film forming property.

  The total solid content concentration in the composition is generally 1 to 10% by mass, preferably 1 to 8.0% by mass, and more preferably 1.0 to 6.0% by mass.

  The above composition is typically used as follows. That is, each of the above components is dissolved in a predetermined solvent (preferably the above mixed solvent), and the obtained solution is filtered and applied onto a predetermined support. The pore size of the filter used for filter filtration is 0.1 μm or less, more preferably 0.05 μm or less, and still more preferably 0.03 μm or less. This filter is preferably made of polytetrafluoroethylene, polyethylene or nylon.

  This composition is applied to a substrate (eg, silicon / silicon dioxide coating, silicon nitride and chromium-deposited quartz substrate, etc.) used for the manufacture of precision integrated circuit elements using a spinner and a coater. Is done. Thereafter, this is dried to form an actinic ray-sensitive or radiation-sensitive film (hereinafter also referred to as a photosensitive film). In addition, a known antireflection film can be applied 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.

<Step (2): Exposure>
Next, the photosensitive film is irradiated with actinic rays or radiation. Examples of the actinic ray or radiation include infrared light, visible light, ultraviolet light, far ultraviolet light, extreme ultraviolet (EUV) light, X-rays, and electron beams. Among these, far ultraviolet light having a wavelength of preferably 250 nm or less, more preferably 220 nm or less, particularly preferably 1 to 200 nm, specifically, KrF excimer laser (248 nm), ArF excimer laser (193 nm), F ₂ Excimer laser (157 nm), EUV light (13 nm), X-ray or electron beam is preferred. In particular, an ArF excimer laser, an F ₂ excimer laser, EUV light, or an electron beam is preferable.

  You may perform immersion exposure with respect to said photosensitive film | membrane. That is, irradiation with actinic rays or radiation may be performed in a state where a liquid having a higher refractive index than air is filled between the film and the lens. Thereby, it becomes possible to further improve the resolution.

<Step (3): Development>
Next, the exposed film is developed. Note that baking (heating) may be performed between exposure and development. By performing baking, a more favorable pattern can be obtained.

  An alkali developer is used for developing the film after exposure. In the pattern forming method according to the present invention, an aqueous tetramethylammonium hydroxide (TMAH) solution having a concentration of less than 2.38% by mass is used as the alkaline developer. This makes it possible to form a pattern having excellent exposure latitude and development defect performance as compared with the case where a TMAH aqueous solution having a concentration of 2.38% by mass or more is used as an alkaline developer.

  The reason why the exposure latitude and development defect performance can be improved by using a TMAH aqueous solution having a concentration of less than 2.38% by mass is not necessarily clear, but the present inventors presume as follows. In other words, the resin dissolution rate becomes too high in a normal concentration developer, and the resin dissolution becomes non-uniform, whereas the use of a diluted developer makes the resin dissolution rate appropriate. I believe.

  The concentration of the aqueous TMAH solution using an alkali developer is preferably in the range of 0.0238% by mass to 1.19% by mass, more preferably in the range of 0.0476% by mass to 0.476% by mass, and still more preferably. Is in the range of 0.0952 mass% to 0.238 mass%. If this concentration is too small, the exposed portion of the film cannot be removed sufficiently, and the pattern shape may deteriorate. If this density is excessively large, exposure latitude and development defect performance may be deteriorated.

An appropriate amount of a surfactant can be added to the developer as necessary.
The surfactant is not particularly limited, and for example, ionic or nonionic fluorine-based and / or silicon-based surfactants can be used. Examples of these fluorine and / or silicon surfactants include, for example, JP-A-62-36663, JP-A-61-226746, JP-A-61-226745, JP-A-62-170950. JP, 63-34540, JP 7-230165, JP 8-62834, JP 9-54432, JP 9-5988, U.S. Pat.No. 5,405,720, Mention may be made of the surfactants described in JP 5360692, JP 5529881, US Pat. Preferably, it is a nonionic surfactant. Although it does not specifically limit as a nonionic surfactant, It is still more preferable to use a fluorochemical surfactant or a silicon-type surfactant. The amount of the surfactant used is usually from 0.001 to 5 mass%, preferably from 0.005 to 2 mass%, more preferably from 0.01 to 0.5 mass%, based on the total amount of the developer.

  As a developing method, for example, a method in which a substrate is immersed in a container filled with a developer for a certain period of time (dip method), a method in which the developer is raised on the surface of the substrate by surface tension and is allowed to stand for a certain period of time (paddle) Method), a method of spraying the developer on the substrate surface (spray method), a method of continuously applying the developer while scanning the developer application nozzle at a constant speed on a substrate rotating at a constant speed (dynamic dispensing method) ) Etc. can be applied.

  The pattern forming method according to the present invention may further include a rinsing step after the developing step. As the rinsing liquid used in this rinsing step, pure water can be used, and an appropriate amount of a surfactant can be added and used. Moreover, you may perform the process which removes the developing solution or rinse liquid adhering on a pattern with a supercritical fluid after a development process or a rinse process.

  The embodiment of the present invention will be described more specifically with reference to examples. However, the scope of the present invention is not limited to the following examples.

<Acid-decomposable resin>
The monomers used for the synthesis of the acid-decomposable resin are listed below.

[Synthesis Example 1: 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 (LM-1), 2.2 g of (IM-1), 9.0 g of (PM-4), and 13 mol% of polymerization initiator V based on the total amount of monomers. A solution prepared by dissolving -60 (manufactured by Wako Pure Chemical Industries, Ltd.) in 79 g of cyclohexanone was dropped 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 mL of methanol and 100 mL of water over 20 minutes, and the precipitated powder was collected by filtration and dried to obtain 18 g of Resin (A-1). The composition ratio of the obtained resin was 39/10/51, the polystyrene equivalent value of the weight average molecular weight by GPC was 7500, and the dispersity (Mw / Mn) was 1.54.

[Synthesis Examples 2 to 20: Resins (A-2) to (A-20)]
Resins (A-2) to (A-20) were synthesized in the same manner as in Synthesis Example 1 except that the types and amounts of the monomers used were changed.

Table 3 below summarizes the monomers used for the synthesis, the composition ratio of each repeating unit, the weight average molecular weight, and the degree of dispersion of the resins (A-1) to (A-20). The composition ratio of repeating units is the molar ratio of repeating units corresponding to each monomer, and corresponds to the order of description of the monomers in the table.

<Acid generator>
As the acid generator, at least one of the following compounds (d1) to (d10), the compound (z66) and the compound (b1) was used. For reference, the following compound (z2) was used.

[Synthesis Example 21: Compound d1]
Compound d1 was synthesized according to the following route.

(Synthesis of Compound 1)
20 g bromomethylcyclohexane and 12.5 g 1-naphthol were dissolved in 300 g NMP in a three neck flask. Thereafter, 12 g of potassium carbonate and 14 g of potassium iodide were added to the obtained solution and heated at 120 ° C. for 8 hours. 300 g of water was added to the reaction solution, and extraction with 100 g of hexane was performed three times. The obtained organic layers were combined, washed once with 100 g of 1N aqueous sodium hydroxide, once with 100 g of water, and once with 100 g of Brine, and then concentrated. In this way, 13 g of Compound 1 was obtained.

(Synthesis of Compound 2)
Compound 2 was synthesized with reference to a method described in JP-A-2005-266799.

(Synthesis of Compound d1)
13.1 g of compound 1 was dissolved in 65 g of Eaton reagent in a three neck flask. Thereafter, 5.7 g of tetramethylene sulfoxide was added dropwise with stirring, and the mixture was further stirred for 3 hours. After pouring the reaction solution into 240 g of water, 25 g of Compound 2 and 50 g of chloroform were added.

  After separating the organic layer, the aqueous layer was extracted twice with 50 g of chloroform. The obtained organic layers were combined, washed twice with water, and concentrated. The resulting crude product was recrystallized using 20 g of ethyl acetate. In this way, 22 g of compound d1 was obtained.

[Synthesis Example 22: Compounds d2 to d10, z66 and b1]
Compounds d2 to d10, z66 and b1 were synthesized in the same manner as described for compound d1.

<Basic compound>
The basic compounds used are as follows.

N-1: N, N-dibutylaniline N-2: N, N-dihexylaniline N-3: 2,6-diisopropylaniline N-4: tri-n-octylamine N-5: N, N-dihydroxyethyl Aniline N-6: 2,4,5-triphenylimidazole N-7: Tris (methoxyethoxyethyl) amine N-8: 2- [2- {2- (2,2-dimethoxy-phenoxyethoxy) ethyl}- Bis- (2-methoxyethyl)]-amine.

<Hydrophobic resin>
The hydrophobic resin was appropriately selected from (HR-1) to (HR-65) and (K-1) to (K-15) listed above.

[Synthesis Example 23: Resin (K-4)]
Monomers corresponding to the following repeating units were charged at a ratio (molar ratio) of 90/10 and dissolved in PGMEA to prepare 450 g of a solution having a solid content concentration of 15% by mass. 1 mol% of Wako Pure Chemical polymerization initiator V-60 was added to this solution. This was dripped at 50g of PGMEA heated at 100 degreeC over 6 hours in nitrogen atmosphere. The reaction liquid was stirred for 2 hours after completion | finish of dripping. After completion of the reaction, the reaction solution was cooled to room temperature, and a solid was precipitated using 5 L of methanol. The obtained white powder was collected by filtration to recover the target resin (K-4).

The composition ratio of each repeating unit determined from NMR was 90/10. Moreover, the standard polystyrene conversion weight average molecular weight calculated | required by GPC measurement was 8000, and dispersion degree was 1.40.

  Resins (K-1) to (K-3) and (K-5) to (K-15) were synthesized in the same manner as in Synthesis Example 23. These resins had the composition ratio, weight average molecular weight and dispersity shown in Table 2 above.

<Surfactant and solvent>
As the surfactant, the following were used.
W-1: MegaFuck F176 (Dainippon Ink Chemical Co., Ltd .; fluorine-based)
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 .; fluorine-based)
W-5: PF656 (manufactured by OMNOVA; fluorine-based)
W-6: PF6320 (manufactured by OMNOVA; fluorine-based).

The following were used as the solvent.
SL-1: Cyclohexanone SL-2: Propylene glycol monomethyl ether acetate (PGMEA)
SL-3: Ethyl lactate SL-4: Propylene glycol monomethyl ether (PGME)
SL-5: γ-butyrolactone SL-6: propylene carbonate.

<Preparation of resist solution>
The components shown in Table 4 below were dissolved in the solvents shown in the same table to prepare a solution having a solid content concentration of 4.5% by mass. Thereafter, the obtained solution was filtered using a polyethylene filter having a pore size of 0.1 μm to prepare a positive resist solution.

<Pattern formation: immersion exposure>
A resist pattern was formed by an immersion exposure method.
Specifically, first, 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. On top of that, the above resist solution was applied and baked at 100 ° C. for 60 seconds. In this way, a resist film having a thickness of 30 nm was formed.

  Next, an ArF excimer laser immersion scanner (manufactured by ASML; XT1700i, NA1.20, C-Quad, outer sigma 0.981, inner sigma 0.895, XY is passed through this resist film through a 65 nm 1: 1 line and space mask. Exposure using deflection). At this time, ultrapure water was used as the immersion liquid.

  Immediately after the exposure, the film was heated on a hot plate at 100 ° C. for 60 seconds and then cooled to room temperature. Next, using a TMAH aqueous solution having a concentration shown in Table 4, the film was developed at 23 ° C. for 30 seconds, rinsed with pure water for 30 seconds, and then post-baked at 90 ° C. for 90 seconds to form a line pattern. Obtained.

<Evaluation of exposure latitude>
An exposure amount that reproduces a line and space mask pattern (line: space = 1: 1) having a line width of 65 nm is an optimum exposure amount, and an exposure amount that allows a pattern size of 65 nm ± 10% when the exposure amount is changed. The width was obtained, and this value was divided by the optimum exposure amount and displayed as a percentage. The larger this value, the smaller the performance change due to the exposure amount change, and the better the exposure latitude.

<Development defect evaluation>
The above composition was uniformly applied on an 8-inch silicon substrate subjected to hexamethyldisilazane treatment using a spin coater, and heated and dried on a hot plate at 120 ° C. for 60 seconds to obtain a film having a thickness of 100 nm. A resist film was formed. This resist film was heated on a hot plate at 110 ° C. for 90 seconds without exposure. Further, the film was developed with a tetramethylammonium hydroxide aqueous solution having a predetermined concentration at 23 ° C. for 60 seconds, rinsed with pure water for 30 seconds, and then dried. With respect to the sample wafer thus obtained, the number of development defects was measured with a KLA 2360 machine (manufactured by KLA Tencor). At this time, the number of defects in Example 1 was normalized to 1 and expressed. The smaller this value, the better.

These evaluation results are shown in Table 4 below.

  As shown in Table 4, in the method according to the example, a pattern having excellent exposure latitude and development defect performance could be formed as compared with the method according to the comparative example.

Claims (11)

Resin (A) whose solubility in an alkaline developer is increased by the action of an acid, and a compound (B) that generates an acid having a partial structure represented by the following general formula (LD) by irradiation with actinic rays or radiation Forming a film using the contained actinic ray-sensitive or radiation-sensitive resin composition;
Exposing the film;
Developing the exposed film with an aqueous tetramethylammonium hydroxide solution having a concentration of less than 2.38% by mass.

Where
Xf each independently represents a fluorine atom or an alkyl group substituted with at least one fluorine atom.
R ₁ and R ₂ each independently represents a group selected from the group consisting of a hydrogen atom, a fluorine atom, an alkyl group, and an alkyl group substituted with at least one fluorine atom.
L each independently represents a single bond or a divalent linking group.
Cy each independently represents a group having a cyclic structure.
x represents the integer of 1-20 each independently.
y represents the integer of 0-10 each independently.
Each z independently represents an integer of 0 to 10. The pattern formation method according to claim 1, wherein the compound (B) generates an acid represented by the following general formula (LD1) or (LD2) upon irradiation with actinic rays or radiation.

Where
Xf each independently represents a fluorine atom or an alkyl group substituted with at least one fluorine atom.
R ₁ and R ₂ each independently represents a group selected from the group consisting of a hydrogen atom, a fluorine atom, an alkyl group, and an alkyl group substituted with at least one fluorine atom.
L each independently represents a single bond or a divalent linking group.
Cy each independently represents a group having a cyclic structure.
Rf represents a group containing a fluorine atom.
x represents the integer of 1-20 each independently.
y represents the integer of 0-10 each independently.
Each z independently represents an integer of 0 to 10.   The said compound (B) is a pattern formation method of Claim 2 which generate | occur | produces the acid represented by the said general formula (LD1) by irradiation of actinic light or a radiation.   The said compound (B) is a pattern formation method of Claim 2 which generate | occur | produces the acid represented by the said general formula (LD2) by irradiation of actinic light or a radiation. The pattern formation method according to claim 4, wherein the acid represented by the general formula (LD2) is represented by the following general formula (LD2I).

Where
Xf each independently represents a fluorine atom or an alkyl group substituted with at least one fluorine atom.
R ₁ and R ₂ each independently represents a group selected from the group consisting of a hydrogen atom, a fluorine atom, an alkyl group, and an alkyl group substituted with at least one fluorine atom.
L each independently represents a single bond or a divalent linking group.
Cy each independently represents a group having a cyclic structure.
x represents the integer of 1-20 each independently.
y represents the integer of 0-10 each independently.
Each z independently represents an integer of 0 to 10.   The pattern forming method according to claim 1, wherein the resin (A) further includes a repeating unit having a lactone structure.   The pattern formation method according to claim 1, wherein the resin (A) includes a repeating unit having a monocyclic or polycyclic acid-decomposable group.   The pattern forming method according to claim 1, wherein the composition further contains a basic compound.   The pattern forming method according to claim 1, wherein the composition further contains a surfactant.   The pattern forming method according to claim 1, wherein the composition further contains a hydrophobic resin.   The pattern forming method according to claim 1, wherein the exposure is immersion exposure.