WO2020241099A1

WO2020241099A1 - Actinic-ray-sensitive or radiation-sensitive resin composition, method for forming pattern, and method for producing electronic device

Info

Publication number: WO2020241099A1
Application number: PCT/JP2020/016565
Authority: WO
Inventors: 務吉村; 研由後藤; 金子　明弘; 宏哲岡
Original assignee: 富士フイルム株式会社
Priority date: 2019-05-29
Filing date: 2020-04-15
Publication date: 2020-12-03
Also published as: JP7254917B2; JPWO2020241099A1; TW202107201A

Abstract

Provided is an actinic-ray-sensitive or radiation-sensitive resin composition which, when used in pattern formation with EUV light, gives patterns having few defects and which, even after long-term storage, gives patterns having excellent LWR performance. Also provided are a method for forming a pattern and a method for producing an electronic device which relate to the actinic-ray-sensitive or radiation-sensitive resin composition. The actinic-ray-sensitive or radiation-sensitive resin composition comprises an acid-decomposable resin and a compound that generates an acid upon irradiation with actinic rays or radiation, wherein the acid-decomposable resin includes repeating unit a1, which is represented by general formula (A1).　In general formula (A1), R^Q represents a hydrogen atom or an organic group.

Description

Actinic light-sensitive or radiation-sensitive resin composition, pattern forming method, manufacturing method of electronic device

The present invention relates to a sensitive light-sensitive or radiation-sensitive resin composition, a pattern forming method, and a method for manufacturing an electronic device.

In the manufacturing process of semiconductor devices such as ICs (Integrated Circuits, integrated circuits) and LSIs (Large Scale Integrated Circuits, large-scale integrated circuits), micromachining by lithography using photosensitive compositions is performed.
Examples of the lithography method include a method of forming a resist film with a photosensitive composition, exposing the obtained film, and then developing the film. In particular, in recent years, studies have been made on the use of EUV (Extreme ultimate) light for exposure (Patent Document 1).

Japanese Unexamined Patent Publication No. 2016-85382

In recent years, it has been required to reduce the defects of patterns formed by using EUV light. Further, even when it is applied to pattern formation after being stored for a long period of time (for example, 180 days) after being manufactured, it is required that the LWR (line width roughness) performance of the obtained pattern is good.

Therefore, the present invention provides a sensitive light-sensitive or radiation-sensitive resin composition that suppresses the occurrence of defects in a pattern formed by using EUV light and can obtain a pattern having excellent LWR performance even when stored for a long period of time. The task is to do.
Another object of the present invention is to provide a pattern forming method and a method for manufacturing an electronic device regarding the above-mentioned sensitive light-sensitive or radiation-sensitive resin composition.

The present inventors have found that the above problems can be solved by the following configuration.

[1]
It contains an acid-degradable resin and a compound that generates an acid when irradiated with active light or radiation.
A photosensitive or radiation-sensitive resin composition in which the acid-decomposable resin has a repeating unit a1 represented by the general formula (A1).

In the general formula (A1), ^RQ represents a hydrogen atom or an organic group.
[2]
The actinic or radiation-sensitive resin composition according to [1], wherein the repeating unit a1 contains a repeating unit a2 having an acid-degradable group.
[3]
The actinic light-sensitive or radiation-sensitive resin composition according to [2], wherein the repeating unit a2 includes a repeating unit a3 represented by the general formula (A2).

In the general formula (A2), ^RQ1 to ^RQ3 each independently represent an alkyl group.
Two of ^RQ1 to ^RQ3 may be combined with each other to form a ring.
[4]
The repeating unit a1 is
^RQ is a hydrogen atom or
A group having one or more specific groups selected from the group consisting of a lactone group, a sulton group, a carbonate group, a hydroxyl group, a sulfonamide group, an amide group, a carboxylic acid group, and a photoacid generating group. The sensitive light-sensitive or radiation-sensitive resin composition according to any one of [1] to [3], which comprises a repeating unit a4 and represents no group X.
[5]
The actinic or radiation-sensitive resin composition according to [4], wherein the repeating unit a4 includes the repeating unit a5 having the group X further having a fluorine atom.
[6]
The actinic or radiation-sensitive resin composition according to [5], wherein the repeating unit a5 contains a repeating unit a6 having the group X having a hexafluoropropanol group.
[7]
The actinic light-sensitive or radiation-sensitive resin composition according to any one of [1] to [6], wherein the acid-decomposable resin has a repeating unit b5 represented by the general formula (B1).

In the general formula (B1), X represents a hydrogen atom, an alkyl group, or a halogen atom other than a fluorine atom.
L ^B represents a single bond or -COO-.
R ^B1 is a lactone group, a sultone group, a carbonate group, a hydroxyl group, a sulfonamido group, an amide group, a carboxylic acid group, and one or more specific groups selected from the group consisting of photoacid generator groups, as well as a fluorine atom Represents a group Z that has a group and is not a elimination group.
[8]
The actinic or radiation-sensitive resin composition according to [7], wherein the repeating unit b5 contains the repeating unit b6 having the group Z having a hexafluoropropanol group.
[9]
The actinic cheilitis or radiation according to any one of [1] to [8], wherein the compound that generates an acid by irradiation with active light or radiation contains a compound represented by the general formula (PA-1). Sex resin composition.

In formula ^{(PA-1), A} 1 and ^{A 2} are each independently, _-SO 2 -R ^P, or represents ^{-CO-R P.} R ^P represents an organic group.
M ⁺ represents a cation.
[10]
The actinic light-sensitive or radiation-sensitive resin according to any one of [1] to [9], wherein the compound that generates an acid by irradiation with active light or radiation contains a compound represented by the general formula (PB). Composition.
M ₁ ⁺ A ^{－－} LB ^－ M ₂ ⁺ (PB)
In formula _{(PB), M} ^{1 +} and _M ^{2 +} each independently represents an organic cation.
L represents a divalent organic group.
A ⁻ represents an acid anion group.
However, in the compound represented by HA-L-BH in which M ₁ ⁺ and M ₂ ^{+ of the} compound represented by the general formula (PB) are respectively substituted with hydrogen atoms, the pKa of the group represented by HA is It is lower than the pKa of the group represented by BH.
B ⁻ represents a group represented by any of the general formulas (B-1) to (B-4).

In the above general formulas (B-1) to (B-4), * represents a bonding position.
In the general formula (B-1) ~ (B -4), R B represents an organic group.
[11]
The actinic cheilitis or sensation according to any one of [1] to [10], wherein the content of the compound that generates an acid by irradiation with the active light or radiation is 15% by mass or more with respect to the total solid content. Radiation resin composition.
[12]
A step of forming a resist film on a substrate using the actinic or radiation-sensitive resin composition according to any one of [1] to [11].
The process of exposing the resist film and
A pattern forming method comprising a step of developing the exposed resist film using a developing solution to form a pattern.
[13]
A method for manufacturing an electronic device, which comprises the pattern forming method according to [12].

According to the present invention, an actinic light-sensitive or radiation-sensitive resin composition capable of suppressing the occurrence of defects in a pattern formed by using EUV light and obtaining a pattern having excellent LWR performance even when stored for a long period of time. Can be provided.
Further, according to the present invention, it is possible to provide a pattern forming method and a method for manufacturing an electronic device regarding the above-mentioned sensitive light-sensitive or radiation-sensitive resin composition.

Hereinafter, an example of a mode for carrying out the present invention will be described.
The numerical range represented by using "-" in the present specification means a range including the numerical values before and after "-" as the lower limit value and the upper limit value.
In the notation of a group (atomic group) in the present specification, the notation that does not describe substitution or non-substitution includes a group having a substituent as well as a group having no substituent. For example, the "alkyl group" includes not only an alkyl group having no substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group).
Unless otherwise specified, the substituent is preferably a monovalent substituent.
As used herein, the term "organic group" refers to a group containing at least one carbon atom.

In the present specification, examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

The bonding direction of the divalent group described in the present specification is not limited unless otherwise specified. For example, when Y is -COO- in the compound represented by the general formula "XYZ", Y may be -CO-O-, and is -O-CO-. You may. Moreover, the said compound may be "X-CO-O-Z" or "X-O-CO-Z".

In the present specification, "(meth) acrylic" is a general term including acrylic and methacrylic, and means "at least one of acrylic and methacrylic". Similarly, "(meth) acrylic acid" means "at least one of acrylic acid and methacrylic acid".

As used herein, the term "active ray" or "radiation" refers to, for example, the emission line spectrum of a mercury lamp, far ultraviolet rays represented by an excimer laser, extreme ultraviolet rays (EUV light: Extreme Ultraviolet), X rays, and electron beams (EB). : Electron Beam) and the like. As used herein, "light" means active light or radiation.
Unless otherwise specified, the term "exposure" as used herein refers to not only exposure to the emission line spectrum of a mercury lamp, far ultraviolet rays represented by excimer lasers, extreme ultraviolet rays, X-rays, EUV light, etc., but also electron beams and It also includes drawing with particle beams such as ion beams.

In the present specification, the weight average molecular weight (Mw), the number average molecular weight (Mn), and the degree of dispersion (also referred to as molecular weight distribution) (Mw / Mn) of the resin are GPC (Gel Permeation Chromatography) apparatus (HLC-manufactured by Toso Co., Ltd.). 8120 GPC) GPC measurement (solvent: tetrahydrofuran, flow rate (sample injection volume): 10 μL, column: TSK gel Multipore HXL-M manufactured by Toso Co., Ltd., column temperature: 40 ° C., flow velocity: 1.0 mL / min, detector: differential refractometer It is defined as a polystyrene conversion value by a rate detector (Refractive Index Detector).

1 Å is 1 x ^10-10 m.

In the present specification, the acid dissociation constant (pKa) represents pKa in an aqueous solution, and specifically, the following software package 1 is used to obtain a value based on a database of Hammett's substituent constants and known literature values. , It is a value obtained by calculation. All pKa values described herein indicate values calculated using this software package.

Software Package 1: Advanced Chemistry Development (ACD / Labs) Software V8.14 for Solaris (1994-2007 ACD / Labors).

On the other hand, pKa can also be obtained by the molecular orbital calculation method. As a specific method for this, there is a method of calculating H ⁺ dissociation free energy in a solvent based on a thermodynamic cycle. (In the present specification, water is usually used as the solvent, and DMSO (dimethyl sulfoxide) is used when pKa cannot be obtained with water.)
The calculation method of H ⁺ dissociation free energy can be calculated by, for example, DFT (density functional theory), but various other methods have been reported in the literature and are not limited to this. There are a plurality of software that can perform DFT, and examples thereof include Gaussian16.

As described above, pKa in the present specification refers to a value obtained by calculation based on a database of Hammett's substituent constants and publicly known literature values using software package 1, and pKa is calculated by this method. If it cannot be calculated, the value obtained by Gaussian 16 based on DFT (density functional theory) shall be adopted.

[Actinic cheilitis or radiation-sensitive resin composition]
The actinic or radiation-sensitive resin composition of the present invention (hereinafter, also referred to as “resist composition”) will be described.
The resist composition of the present invention may be a positive type resist composition or a negative type resist composition. Further, it may be a resist composition for alkaline development or a resist composition for organic solvent development.
The composition of the present invention is typically a chemically amplified resist composition.

The resist composition of the present invention contains an acid-degradable resin and a compound that generates an acid by irradiation with active light or radiation, and the acid-degradable resin is repeatedly represented by the general formula (A1) described later. It has a repeating unit a1 which is a unit.
The mechanism by which the problem of the present invention is solved by such a configuration is not always clear, but the present inventors consider it as follows.
EUV light has a wavelength of 13.5 nm, which is shorter than that of ArF (wavelength 193 nm) light and the like, so that the number of incident photons when exposed with the same sensitivity is small. Therefore, the influence of "photon shot noise" in which the number of photons varies stochastically is large, which causes an increase in defects in the obtained pattern and deterioration of LWR performance.
Therefore, in the present invention, the acid-decomposable resin contained in the resist composition contains a repeating unit a1 which is an acrylic repeating unit (α-fluoroacrylic repeating unit) having a fluorine atom at the α-position. The presence of fluorine atoms at the α-position of such repeating units adjusts the compatibility of the resin with the developer within an appropriate range while improving the absorption efficiency of EUV light, causing defects in the formed pattern and the occurrence of defects. It is considered that the deterioration of LWR performance is suppressed.
Further, it is considered that the fluorine atom at the α-position has a small adverse effect on the stability of the acid-degradable resin, and the deterioration of the LWR performance of the formed pattern is suppressed even when the resist composition is stored for a long period of time.
Hereinafter, in the present specification, the characteristics of the resist composition in which the occurrence of defects in the formed pattern is suppressed are also referred to as the resist composition having excellent defect suppressing properties. Further, it is also said that the excellent LWR performance of the pattern formed after the resist composition is stored for a long period of time is excellent in the LWR performance of the resist composition after aging.
It is also said that the effect of the present invention is excellent when at least one of the defect suppressing property and the LWR performance after aging is excellent in the resist composition.

[Components of resist composition]
Hereinafter, the components that the resist composition may contain will be described in detail.

<(A) Acid-degradable resin>
The resist composition contains an acid-decomposable resin (hereinafter, also referred to as “resin (A)”).
The resin (A) is typically a resin in which the polarity is increased by the action of an acid, the solubility in an alkaline developer is increased, and the solubility in an organic solvent is decreased.
The resin (A) has a group that decomposes by the action of an acid to generate a polar group (in other words, a structure in which the polar group is protected by a leaving group that is eliminated by the action of an acid). Such a group (structure) is also called an acid-degradable group. A resin having an acid-degradable group (that is, a resin having a repeating unit having an acid-degradable group) has an increased polarity due to the action of an acid, an increase in solubility in an alkaline developer, and a decrease in solubility in an organic solvent.
As will be described later, the resin (A) may have a repeating unit having a photoacid generating group.
Above all, the resin (A) preferably has an acid group having an acid dissociation constant (pKa) of 13 or less. As described above, the acid dissociation constant of the acid group is preferably 13 or less, more preferably 3 to 13, and even more preferably 5 to 10.
When it has the above-mentioned acid group of predetermined pKa, the storage stability of the resist composition is excellent, and the development proceeds more satisfactorily.
Examples of the acid group having an acid dissociation constant (pKa) of 13 or less include a carboxylic acid group, a phenolic hydroxyl group, a fluorinated alcohol group (preferably a hexafluoroisopropanol group), a sulfonic acid group, a sulfonic acid group, and the like. Be done.

(Repeating unit a1)
The resin (A) has a repeating unit a1.
The repeating unit a1 is a repeating unit represented by the general formula (A1).

In the general formula (A1), ^RQ represents a hydrogen atom or an organic group.
Limiting the organic group represented by R ^Q is not, for example, group (in this case R ^Q is a leaving group) to form an acid-decomposable group as a whole -COO-R ^Q may be a, so It does not have to be.
It part or whole of R ^Q may be a group which is an acid-decomposable group, or not.
^RQ may be a polar group or a non-polar group.
R ^Q is a lactone group, a sultone group, a carbonate group, a hydroxyl group (or aromatic hydroxyl groups in a non-aromatic hydroxyl groups), a sulfonamido group, an amide group, a carboxylic acid group, and, from the group consisting of photoacid generator groups It may or may not be a group having one or more specific groups to be selected.
R ^Q may have a fluorine atom, or may not have.

The content of the repeating unit represented by the general formula (A1) in the resin (A) is preferably 5 to 100 mol%, more preferably 10 to 100 mol%, based on all the repeating units of the resin (A). , 20-100 mol% is more preferred.
Two or more kinds of repeating units represented by the general formula (A1) may be used.

・ Repeat unit a2
It is also preferable that the repeating unit a1 includes the repeating unit a2 having an acid-degradable group.
That is, it is also preferable that the resin (A) has the repeating unit a2.
More specifically, the repeating unit a2 is a repeating unit represented by the general formula (A1), and the repeating unit having an acid-degradable group (the polar group is protected by a leaving group that is eliminated by the action of an acid). It is a repeating unit having a structure.
In other words, the repeating unit a2 is a form of the repeating unit a1.

The polar group in the repeating unit having a structure in which the polar group is protected by the desorbing group desorbed by the action of an acid (acid-degradable group) is preferably an alkali-soluble group, for example, a carboxylic acid group, a phenolic hydroxyl group, or fluorine. Alcohol chemical group, sulfonic acid group, sulfonamide group, sulfonylimide group, (alkylsulfonyl) (alkylcarbonyl) methylene group, (alkylsulfonyl) (alkylcarbonyl) imide group, bis (alkylcarbonyl) methylene group, bis (alkylcarbonyl) ) Methylene group, bis (alkylsulfonyl) methylene group, bis (alkylsulfonyl) imide group, tris (alkylcarbonyl) methylene group, acidic group such as tris (alkylsulfonyl) methylene group, alcoholic hydroxyl group and the like. Be done.
Among them, the polar group is preferably a carboxylic acid group, a phenolic hydroxyl group, a fluorinated alcohol group (preferably a hexafluoroisopropanol group), or a sulfonic acid group.
If the polar group is a carboxylic acid group, R ^Q may be a leaving group itself in the general formula (A1). That is, in this case, the leaving group (R ^Q) polar group (carboxylic acid group) is protected by the structure (acid-decomposable group) is formed, as a whole acidolysis -COO-R ^Q in the general formula (A1) is It constitutes a sex group.
Further, it may be contained partially in the acid-decomposable group of R ^Q in the general formula (A1), R ^Q may constitute the acid-decomposable group as a whole.

Examples of the leaving group that are eliminated by the action of an acid include groups represented by the formulas (Y1) to (Y4).
Equation (Y1): -C (Rx ₁ ) (Rx ₂ ) (Rx ₃ )
Equation (Y2): -C (= O) OC (Rx ₁ ) (Rx ₂ ) (Rx ₃ )
Equation (Y3): -C (R ₃₆ ) (R ₃₇ ) (OR ₃₈ )
Formula (Y4): -C (Rn) (H) (Ar)

In formulas (Y1) and (Y2), Rx ₁ to Rx ₃ are independently alkyl groups (linear or branched chain), cycloalkyl groups (monocyclic or polycyclic), and alkenyl groups (straight chain). (Orchid or branched chain) or aryl group (monocyclic or polycyclic). When all of Rx ₁ to Rx ₃ are alkyl groups (linear or branched chain), it is preferable that at least two of Rx ₁ to Rx ₃ are methyl groups.
Among them, it is preferable that Rx ₁ to Rx ₃ independently represent a linear or branched alkyl group.
Two of Rx ₁ to Rx ₃ may be combined to form a monocyclic or polycyclic ring.
The alkyl group of Rx ₁ to Rx ₃ is preferably an alkyl group having 1 to 5 carbon atoms such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a t-butyl group. .. The substituent that the alkyl group may have is preferably a hydroxyl group or a halogen atom. The alkyl group is preferably an unsubstituted alkyl group or an alkyl group having only one selected from the group consisting of a hydroxyl group and a halogen atom as the substituent.
The cycloalkyl groups of Rx ₁ to Rx ₃ include a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group, or a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, an adamantyl group, or the like. Polycyclic cycloalkyl groups are preferred.
The aryl group of Rx ₁ to Rx ₃ is preferably an aryl group having 6 to 10 carbon atoms, and examples thereof include a phenyl group, a naphthyl group, and an anthryl group.
The alkenyl group of Rx ₁ to Rx ₃ is preferably a vinyl group.
The ring formed by bonding two of Rx ₁ to Rx ₃ is preferably a cycloalkyl group. The cycloalkyl group formed by combining two of Rx ₁ to Rx ₃ is a cyclopentyl group, a monocyclic cycloalkyl group such as a cyclohexyl group, or a norbornyl group, a tetracyclodecanyl group, or a tetracyclododecanyl. A polycyclic cycloalkyl group such as a group or an adamantyl group is preferable.
The cycloalkyl group formed by combining two of Rx ₁ to Rx ₃ is, for example, a group in which one of the methylene groups constituting the ring has a hetero atom such as an oxygen atom, a hetero atom such as a carbonyl group, or vinylidene. It may be replaced by a group. Further, in these cycloalkyl groups, one or more of the ethylene groups constituting the cycloalkane ring may be replaced with a vinylene group.
The substituent that the ring formed by combining two of Rx ₁ to Rx ₃ may have is a perhalogenated alkyl group (either linear or branched chain, preferably a perfluoroalkyl group, preferably). The number of carbon atoms 1 to 3), a hydroxyl group, or a halogen atom is preferable. The ring is preferably an unsubstituted ring or a ring having only a substituent selected from the group consisting of a perhalogenated alkyl group, a hydroxyl group, and a halogen atom as a substituent.
The group represented by the formula (Y1) or the formula (Y2) is, for example, an embodiment in which Rx ₁ is a methyl group or an ethyl group, and Rx ₂ and Rx ₃ are bonded to form the above-mentioned cycloalkyl group. Is preferable.

In formula (Y3), R ₃₆ to R ₃₈ each independently represent a hydrogen atom or a monovalent organic group. R ₃₇ and R ₃₈ may be combined with each other to form a ring. Examples of the monovalent organic group include an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, an alkenyl group and the like. It is also preferable that R ₃₆ is a hydrogen atom.
The alkyl group, cycloalkyl group, aryl group, and aralkyl group may contain a heteroatom such as an oxygen atom and / or a group having a heteroatom such as a carbonyl group. For example, in the above-mentioned alkyl group, cycloalkyl group, aryl group, and aralkyl group, for example, one or more methylene groups are replaced with a group having a hetero atom such as an oxygen atom and / or a hetero atom such as a carbonyl group. You may.

The formula (Y3) is preferably a group represented by the following formula (Y3-1).

Here, L ₁ and L ₂ independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a group in which these are combined (for example, a group in which an alkyl group and an aryl group are combined). ..
M represents a single bond or a divalent linking group.
Q is an alkyl group that may contain a hetero atom, a cycloalkyl group that may contain a hetero atom, an aryl group that may contain a hetero atom, an amino group, an ammonium group, a mercapto group, a cyano group, and an aldehyde. Represents a group or a group in which these are combined (for example, a group in which an alkyl group and a cycloalkyl group are combined).
As for the alkyl group and the cycloalkyl group, for example, one of the methylene groups may be replaced with a hetero atom such as an oxygen atom or a group having a hetero atom such as a carbonyl group.
As the alkyl group, for example, it is preferable that one or more hydrogen atoms are substituted with fluorine atoms to form a fluoroalkyl group (for example, a fluoroalkyl group having 1 to 5 carbon atoms).
It is preferable that _one of L ₁ and L ₂ is a hydrogen atom and the other is an alkyl group, a cycloalkyl group, an aryl group, or a group in which an alkylene group and an aryl group are combined.
Q, M, and, at least two members to the ring (preferably, 5-membered or 6-membered ring) L ₁ may be formed.
From the viewpoint of pattern miniaturization, L ₂ is preferably a secondary or tertiary alkyl group, and more preferably a tertiary alkyl group. Examples of the secondary alkyl group include an isopropyl group, a cyclohexyl group and a norbornyl group, and examples of the tertiary alkyl group include a tert-butyl group and an adamantyl group. In these aspects, since Tg (glass transition temperature) and activation energy are high, fog can be suppressed in addition to ensuring the film strength.

In the formula (Y4), Ar represents an aromatic ring group. Rn represents an alkyl group, a cycloalkyl group, or an aryl group. Rn and Ar may be combined with each other to form a non-aromatic ring. Ar is preferably an aryl group.

In the desorbing group that protects the polar group, when the non-aromatic ring is directly bonded to the polar group (or its residue), in the non-aromatic ring, from the viewpoint of excellent acid decomposition property of the repeating unit, It is also preferable that the ring member atom adjacent to the ring member atom directly bonded to the polar group (or its residue) does not have a halogen atom such as a fluorine atom as a substituent.

Other desorbing groups eliminated by the action of an acid include a 2-cyclopentenyl group having a substituent (alkyl group, etc.) such as a 3-methyl-2-cyclopentenyl group, and 1,1,4. , A cyclohexyl group having a substituent (alkyl group, etc.) such as 4-tetramethylcyclohexyl group may be used.

・・ Repeat unit a3
It is also preferable that the repeating unit a2 includes the repeating unit a3 represented by the general formula (A2).
That is, the resin (A) preferably has the repeating unit a3.
In other words, the repeating unit a3 is a repeating unit represented by the general formula (A2), and is a form of the repeating unit a2.

In the general formula (A2), ^RQ1 to ^RQ3 each independently represent an alkyl group (linear or branched chain).
The alkyl groups of ^RQ1 to ^RQ3 independently have 1 to 5 carbon atoms such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a t-butyl group. Alkyl groups are preferred. The substituent that the alkyl group may have is preferably a hydroxyl group or a halogen atom. The alkyl group is preferably an unsubstituted alkyl group or an alkyl group having only one selected from the group consisting of a hydroxyl group and a halogen atom as the substituent.

Two of ^RQ1 to ^RQ3 may be combined with each other to form a ring.
A cycloalkyl group is preferable for the ring formed by bonding two of ^RQ1 to ^RQ3 .
Two of the cycloalkyl group formed by binding of R ^{Q1 ~} R ^Q3 is cyclopentyl, or a monocyclic cycloalkyl group such as cyclohexyl group, or a norbornyl group, tetra tricyclodecanyl group, tetracyclo A polycyclic cycloalkyl group such as a dodecanyl group or an adamantyl group is preferable.
In the cycloalkyl group formed by bonding two of ^RQ1 to ^RQ3 , one of the methylene groups constituting the ring is a heteroatom such as an oxygen atom, a group having a heteroatom such as a carbonyl group, or vinylidene. It may be replaced by a group. Further, in these cycloalkyl groups, one or more of the ethylene groups constituting the cycloalkane ring may be replaced with a vinylene group.
The substituent that the ring formed by combining two of ^RQ1 to ^RQ3 may have is an alkyl perhalogenated group (either linear or branched chain, preferably a perfluoroalkyl group, It preferably has 1 to 3 carbon atoms, a hydroxyl group, or a halogen atom. The ring is preferably an unsubstituted ring or a ring having only a substituent selected from the group consisting of a perhalogenated alkyl group, a hydroxyl group, and a halogen atom as a substituent.

When the resin (A) has the repeating unit a2 (preferably the repeating unit a3), the content thereof is preferably 5 to 90 mol% and 10 to 85 mol% with respect to all the repeating units of the resin (A). More preferably, 20 to 70 mol% is further preferable.
As the repeating unit a2 (preferably the repeating unit a3), one type may be used alone, or two or more types may be used.

-Repeating unit a4 (repeating unit a5, repeating unit a6)
It is also preferable that the repeating unit a1 includes the repeating unit a4.
That is, the resin (A) preferably has the repeating unit a4.
Repeating units a4 is in the repeating unit represented by the general formula (A1) (repeating unit a1), ^{R Q} is a hydrogen atom, or a group X, a repeating unit.
Group X consists of a group consisting of a lactone group, a sulton group, a carbonate group, a hydroxyl group (which may be a non-aromatic hydroxyl group or an aromatic hydroxyl group), a sulfonamide group, an amide group, a carboxylic acid group, and a photoacid generating group. A group having one or more specific groups to be selected, not a leaving group.
The repeating unit a4 is a form of the repeating unit a1.

In the repeating unit a4, group X is a choice of R ^Q is a group having a specific group, and a group not leaving group.
The "group that is not a leaving group" means a group that is not the "leaving group that is eliminated by the action of an acid" described with respect to the repeating unit a2. Specifically, the "group that is not a leaving group" does not correspond to the group represented by the above formulas (Y1) to (Y4).
The repeating unit a4 is preferably different from the repeating unit a2 and / or the repeating unit a3.

R ^Q is is a group X, may be R ^Q is a specific group itself may contain certain groups in a part of R ^Q.

When the resin (A) has the repeating unit a4, the content thereof is preferably 1 to 70 mol%, more preferably 2 to 60 mol%, and 3 to 50 mol% with respect to all the repeating units of the resin (A). % Is more preferable.
The repeating unit a4 may be used alone or in combination of two or more.

It is also preferable that the repeating unit a4 includes a repeating unit a5 having a group X further having a fluorine atom.
That is, the resin (A) preferably has the repeating unit a5.
More specifically, the repeating unit a5 is a repeating unit represented by the general formula (A1), wherein the ^RQ is the above-mentioned group X and the above-mentioned group X is a group having a fluorine atom. It is a unit.
That is, the repeating unit a5 is a form of the repeating unit a4.

Among them, it is also preferable that the repeating unit a5 includes a repeating unit a6 having a group X having a hexafluoropropanol group (a group represented by "-C (CF ₃ ) ₂ OH").
That is, the resin (A) preferably has the repeating unit a6.
More specifically, the repeating unit 6, in the repeating unit represented by formula (A1), R ^Q is a foregoing group X, and is a group where the group X has a hexafluoroisopropanol group aspects It is a repeating unit of.
That is, the repeating unit a6 is also a form of the repeating unit a4 and the repeating unit a5.

・・ Repeat unit a4-0
If R ^Q of the repeating unit represented by formula (A1) is a hydrogen atom, such repeating units, also referred to as repeating units A4-0.
When the resin (A) has the repeating unit a4-0, the content thereof is preferably 1 to 30 mol%, more preferably 2 to 20 mol%, and 3 to 3 to all the repeating units of the resin (A). 15 mol% is more preferred.

・・ Repeat unit a4-1
In the repeating unit a4, R ^Q is, as a specific group, lactone group, sultone group, and, if a group X with at least one selected from the group consisting of carbonate group, such repeating units a4, repeated Also called the unit a4-1.

It is also preferable that the lactone group, the sultone group, and the carbonate group have a fluorine atom as a substituent. That is, it is also preferable that the repeating unit a4-1 is the repeating unit a5.

The lactone group or sultone group of the repeating unit a4-1 may have a lactone structure or a sultone structure. The lactone structure or sultone structure is preferably a 5- to 7-membered ring lactone structure or a 5- to 7-membered ring sultone structure. Among them, the lactone structure is preferably a structure in which another ring structure is condensed into a 5- to 7-membered ring lactone structure so as to form a bicyclo structure or a spiro structure. The sultone structure is more preferably a 5- to 7-membered ring sultone structure in which another ring structure is fused to form a bicyclo structure or a spiro structure.
The lactone group is preferably a lactone group obtained by extracting one or more hydrogen atoms from a ring member atom having a lactone structure represented by any of the following general formulas (LC1-1) to (LC1-22). The sultone group is preferably a sultone group obtained by extracting one or more hydrogen atoms from a ring member atom having a sultone structure represented by any of the following general formulas (SL1-1) to (SL1-3).

The lactone structure or sultone structure portion may have a substituent (Rb ₂ ). Preferred substituents (Rb ₂ ) include, for example, an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 4 to 7 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, and an alkoxycarbonyl group having 1 to 8 carbon atoms. Examples thereof include a carboxylic acid group, a halogen atom (preferably a fluorine atom), a hydroxyl group, and a cyano group. n2 represents an integer of 0 to 4. When n2 is 2 or more, Rb ₂ existing in plural numbers may be different or may be bonded to form a ring Rb ₂ between the plurality of.

A repeating unit a4-1 having a lactone group obtained by extracting one or more hydrogen atoms from a ring member atom having a lactone structure represented by any of the general formulas (LC1-1) to (LC1-22), and general The repeating unit a4-1 having a sultone group obtained by extracting one or more hydrogen atoms from a ring member atom having a sultone structure represented by any of the formulas (SL1-1) to (SL1-3) is a general formula (SL1-1). The repeating unit represented by A3) is preferable.

In the general formula (A3), Ab is a divalent linking group having a single bond, an alkylene group, a monocyclic or polycyclic alicyclic hydrocarbon structure, an ether group, an ester group, a carbonyl group, a carboxylic acid group, or It represents a divalent group that combines these.
Among them, a single bond, or a _-Ab 1 -COO- linking group represented by are preferred.
Ab ₁ is a monobonded or divalent linking group, a linear or branched alkylene group, or a monocyclic or polycyclic cycloalkylene group, which is a methylene group, an ethylene group, a cyclohexylene group, or an adaman. A tylene group or a norbornylene group is preferable.
V is a group formed by extracting one hydrogen atom from a ring member atom having a lactone structure represented by any of the general formulas (LC1-1) to (LC1-22), or general formulas (SL1-1) to (SL1-1). It represents a group formed by extracting one hydrogen atom from a ring member atom having a sultone structure represented by any of SL1-3).

If an optical isomer is present in the repeating unit a4-1 having a lactone group or a sultone group, any optical isomer may be used. Further, one kind of 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, its optical purity (ee) is preferably 90 or more, more preferably 95 or more.

The carbonate group in the repeating unit a4-1 having a carbonate group is preferably contained in the cyclic carbonate group.
The repeating unit a4-1 having a carbonate group is preferably a repeating unit represented by the general formula (A4).

In the general formula (A4), n represents an integer of 0 or more (preferably 0 to 3).
R _A ² represents a substituent. when n is 2 or more, R _A ² existing in plural, may each be the same or different.
A represents a single bond or a divalent linking group. The divalent linking group is an alkylene group (preferably having 1 to 4 carbon atoms), a divalent linking group having a monocyclic or polycyclic alicyclic hydrocarbon structure, an ether group, an ester group, a carbonyl group, and a carboxylic acid. A group or a divalent group in which these are combined is preferable.
Z represents an atomic group forming a monocyclic or polycyclic ring with a group represented by —O—CO—O— in the formula.
The monocyclic or polycyclic ring formed by Z together with the group represented by —O—CO—O— in the formula is preferably a 5-membered cyclic carbonate group, and is represented by the following general formula (CC1-1). A cyclic carbonate structure is more preferred.
That is, it is preferable that A in the general formula (A4) is bonded to a group formed by extracting one hydrogen atom from the ring member atom of the cyclic carbonate structure represented by the following general formula (CC1-1). ..

The cyclic carbonate structure portion in the general formula (CC1-1) may have a substituent (Rb ₂ ). Preferred substituents (Rb ₂ ) include, for example, an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 4 to 7 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, and an alkoxycarbonyl group having 1 to 8 carbon atoms. Examples thereof include a carboxylic acid group, a halogen atom (preferably a fluorine atom), a hydroxyl group, and a cyano group. n3 represents an integer of 0 or 1.

When the resin (A) has the repeating unit a4-1, the content thereof is preferably 3 to 60 mol%, more preferably 5 to 50 mol%, and 7 to 7 to all the repeating units of the resin (A). 45 mol% is more preferred.
The repeating unit a4-1 may be used alone or in combination of two or more.

・・ Repeat unit a4-2
In the repeating unit a4, R ^Q is a group X having a non-aromatic hydroxyl group as a specific group, if the non-aromatic hydroxyl groups, a hydroxyl group other than hydroxyl groups contained in a fluorinated alcohol group, like this The repeating unit a4 is also referred to as a repeating unit a4-2.
The non-aromatic hydroxyl group is a hydroxyl group other than the aromatic hydroxyl group, and is intended, for example, a hydroxyl group other than the hydroxyl group directly bonded to the aromatic ring. Examples of the non-aromatic hydroxyl group include an alcoholic hydroxyl group.
The hydroxyl groups other than the hydroxyl group contained in the fluorinated alcohol group include, for example, a hydroxyl group bonded to a carbon atom, and the carbon atom (α carbon) to which the hydroxyl group is bonded, a fluorine atom and −CFR ₂ (two Rs are Each of them independently represents a hydrogen atom or a substituent. -CFR ₂ includes -CF _{3 and the} like), and is the above-mentioned hydroxyl group when none of them is bonded.
The repeating unit a4-2 is preferably different from the repeating unit a4-1.
The repeating unit a4-2 preferably has no fluorinated alcohol group.

The repeating unit a4-2 is preferably a repeating unit represented by the general formula (A5).

In the general formula (A5), ^RQ5 represents an alkyl group (linear or branched chain, preferably 1 to 5 carbon atoms) or a non-aromatic ring group.

Examples of the non-aromatic ring group include a monocyclic hydrocarbon ring group and a polycyclic hydrocarbon ring group.
Examples of the monocyclic hydrocarbon ring group include a cycloalkane ring group having 3 to 12 carbon atoms (preferably 3 to 7 carbon atoms) and a cycloalkene ring group having 3 to 12 carbon atoms.
Examples of the polycyclic hydrocarbon ring group include a ring-assembled hydrocarbon ring group and a crosslinked ring-type hydrocarbon ring group.
Examples of the crosslinked ring-type hydrocarbon ring include a bicyclic hydrocarbon ring, a three-ring hydrocarbon ring, and a four-ring hydrocarbon ring. Further, the crosslinked cyclic hydrocarbon ring may be a condensed ring in which a plurality of 5- to 8-membered cycloalkane rings are condensed.
The crosslinked cyclic hydrocarbon ring group is preferably a norbornane ring group, an adamantane ring group, a bicyclooctane ring group, or a tricyclo [5, ^2, 1, 0 ^{2, 6} ] decane ring group.

It is also preferable that the alkyl group and the non-aromatic ring group do not have a substituent other than − (OH) _q5 .

In the general formula (A5), q5 represents an integer from 1 to 5.

When the resin (A) has the repeating unit a4-2, the content thereof is preferably 3 to 60 mol%, more preferably 5 to 50 mol%, and 10 to 10 to all the repeating units of the resin (A). 45 mol% is more preferred.
The repeating unit a4-2 may be used alone or in combination of two or more.

・・ Repeat unit a4-3
In the repeating unit a4, R ^Q is a group X having a non-aromatic hydroxyl group as a specific group, the non-aromatic hydroxyl groups, when a hydroxyl group contained in a fluorinated alcohol group, such repeating units a4 Is also referred to as a repeating unit a4-3.
The hydroxyl groups contained in the fluorinated alcohol group include, for example, a hydroxyl group bonded to a carbon atom, and the carbon atom (α carbon) to which the hydroxyl group is bonded, a fluorine atom and -CFR ₂ (two Rs are independent of each other). It represents a hydrogen atom or a substituent. -CFR ₂ includes -CF _{3 and the} like), and is the above-mentioned hydroxyl group when at least one is bonded.
That is, the repeating unit a4-3 corresponds to the repeating unit a5.
The repeating unit a4-3 is preferably different from the repeating unit a4-1 and / or the repeating unit a4-2.

The hydroxyl group contained in the fluorinated alcohol group is preferably a hydroxyl group contained in a hexafluoroisopropanol group (a group represented by "-C (CF ₃ ) ₂ OH").
That is, the repeating unit a4-3 preferably corresponds to the repeating unit a6.

The repeating unit a4-3 is preferably a repeating unit represented by the general formula (A6).

In the general formula (A6), ^RQ6 represents an alkyl group (linear or branched chain, preferably 1 to 5 carbon atoms), a non-aromatic ring group, or an aromatic ring group.

The aromatic ring group preferably has an aromatic ring group having 6 to 18 carbon atoms, and more preferably a benzene ring group, a naphthalene ring group, an anthracene ring group, or a biphenylene ring group.

It is also preferable that the alkyl group, the non-aromatic ring group, and the aromatic ring group do not have a substituent other than − (−C (CF ₃ ) ₂ OH) _q6 .

In the general formula (A6), q6 represents an integer from 1 to 5.

When the resin (A) has the repeating unit a4-3, the content thereof is preferably 3 to 50 mol%, more preferably 5 to 40 mol%, and 10 to 10 to all the repeating units of the resin (A). 35 mol% is more preferred.
The repeating unit a4-3 may be used alone or in combination of two or more.

・・ Repeat unit a4-4
In the repeating unit a4, R ^Q is is a group X having a photoacid generating group as a specific group, such a repeating unit a4, also referred to as repeating units A4-4.
In the repeating unit A4-4, also preferred ^{R Q} has a fluorine atom. That is, the repeating unit a4-4 preferably corresponds to the repeating unit a5.
The repeating unit a4-4 is preferably different from the repeating unit a4-1, the repeating unit a4-2, and / or the repeating unit a4-3.

The repeating unit a4-4 is preferably a repeating unit represented by the general formula (A7).

In the general formula (A7), the two Xfs independently represent an alkyl group (preferably CF ₃ ) substituted with a hydrogen atom, a fluorine atom, or at least one fluorine atom.
Of the two Xfs, at least one is preferably a non-hydrogen atom.
The alkyl group may be linear or branched. The alkyl group preferably has 1 to 10 carbon atoms. The alkyl group preferably has only a fluorine atom as a substituent.

In the general formula (A7), R ¹ and R ² independently represent a hydrogen atom, a fluorine atom, or an alkyl group, and when a plurality of them are present, R ¹ and R ² may be the same or different. Good.
The alkyl group may be linear or branched. The alkyl group preferably has 1 to 10 carbon atoms. The substituent of the alkyl group is preferably a fluorine atom. When the alkyl group has a substituent, it is preferable that the alkyl group has only a fluorine atom as the substituent.

In the general formula (A7), L represents a divalent linking group, and when a plurality of L are present, L may be the same or different.
The divalent linking group of L is -COO-, -CO-, -O-, -S-, -SO-, -SO _2- , alkylene group, cycloalkylene group, alkenylene group, and a plurality of these. Examples thereof include linked linking groups, and linking groups having a total carbon number of 12 or less are preferable.

In the general formula (A7), x represents an integer of 1 to 20, y represents an integer of 0 to 10, and z represents an integer of 0 to 10.

In the general formula (A7), M ⁺ represents a cation. For details of M ⁺ , for example, the same cation as M ⁺ in the general formula (PA-1) described later can be used.

When the resin (A) has the repeating unit a4-4, the content thereof is preferably 3 to 40 mol%, more preferably 5 to 25 mol%, and 7 to 7 to all the repeating units of the resin (A). 20 mol% is more preferred.
The repeating unit a4-4 may be used alone or in combination of two or more.

・ Repeat unit a1-2
The repeating unit a1 may include a repeating unit that does not correspond to any of the repeating unit a2, the repeating unit a3, and the repeating unit a4.
That is, the resin (A) may have a repeating unit a1 that does not correspond to any of the repeating unit a2, the repeating unit a3, and the repeating unit a4. Such a repeating unit a1 is also referred to as a repeating unit a1-2.

The repeating unit a1-2 is preferably a repeating unit represented by the general formula (A1-2).

In the general formula (A1-2), ^RQ12 represents an alkyl group (linear or branched chain, preferably 1 to 5 carbon atoms), a non-aromatic ring group, or an aromatic ring group.
However, ^RQ12 is not a leaving group.

The aromatic ring group preferably has an aromatic ring group having 6 to 18 carbon atoms, and preferably a benzene ring group, a naphthalene ring group, an anthracene ring group, and a biphenylene ring group.

The alkyl group, the non-aromatic ring group, and the aromatic ring group do not have, as substituents, the specific group described with respect to the repeating unit a4 and a group containing a specific group in a part thereof. The alkyl group, the non-aromatic ring group, and the aromatic ring group are preferably unsubstituted.

When the resin (A) has the repeating unit a1-2, the content thereof is preferably 1 to 30 mol%, more preferably 3 to 25 mol%, and 5 to 5 to all the repeating units of the resin (A). 20 mol% is more preferred.
The repeating unit a1-2 may be used alone or in combination of two or more.

(Repeating unit b1)
The resin (A) may have a repeating unit that does not correspond to the repeating unit a1 (that is, a repeating unit that does not correspond to the repeating unit represented by the general formula (A1)).
Such a repeating unit that does not correspond to the repeating unit a1 is also referred to as a repeating unit b1.
Examples of the repeating unit b1 include a repeating unit represented by the general formula (A1-b).

In the general formula (A1-b), X represents a hydrogen atom, an alkyl group, or a halogen atom other than a fluorine atom.
The alkyl group may be linear or branched. The alkyl group preferably has 1 to 10 carbon atoms. The substituent of the alkyl group is preferably a hydroxyl group or a halogen atom. When the alkyl group has a substituent, it is preferable that the alkyl group has only a hydroxyl group and / or a halogen atom as the substituent. The alkyl group is preferably -CH ₃ .
The halogen atom other than the fluorine atom is preferably a chlorine atom, a bromine atom, or an iodine atom.

In the general formula (A1-b), ^{L B} represents a single bond or -COO-. The carbonyl carbon in -COO- is preferably directly attached to the main chain of the repeating unit.

^{R Q} in formula (A1-b) in is the same as ^{R Q} in the general formula (A1).

The content of the repeating unit b1 (repeating unit represented by the general formula (A1-b), etc.) in the resin (A) is preferably 0 to 95 mol% with respect to all the repeating units of the resin (A). 9 to 90 mol% is more preferable, and 0 to 80 mol% is further preferable.
Two or more kinds of repeating units represented by the general formula (A1) may be used.

-Repeating unit b2
It is also preferable that the repeating unit b1 includes the repeating unit b2.
That is, the resin (A) preferably has the repeating unit b2.
The repeating unit b2 is a repeating unit other than the repeating unit a1 and is a repeating unit having an acid-degradable group (a repeating unit having a structure in which a polar group is protected by a leaving group that is eliminated by the action of an acid). ..
The description of the acid-degradable group, the leaving group, and the polar group is as described above.

.. Repeat unit b3
It is also preferable that the repeating unit b2 includes the repeating unit b3.
The resin (A) also preferably has the repeating unit b3.
The repeating unit b3 is a form of the repeating unit b2.
The repeating unit b3 is a repeating unit represented by the general formula (A2-b).

X in the general formula (A2-b) represents a hydrogen atom, an alkyl group, or a halogen atom other than a fluorine atom, and is the same as X in the general formula (A1-b).
^R Q1 ^{~ R Q3} in formula (A2-b) in is the same as ^R Q1 ^{~ R Q3} in the general formula (A2).

When the resin (A) has the repeating unit b2 (preferably the repeating unit b3), the content thereof is preferably 5 to 90 mol% and 10 to 85 mol% with respect to all the repeating units of the resin (A). More preferably, 20 to 70 mol% is further preferable.
As the repeating unit a2 (preferably the repeating unit a3), one type may be used alone, or two or more types may be used.
The total content of the repeating unit a2 (preferably the repeating unit a3) and the repeating unit b2 (preferably the repeating unit b3) in the resin (A) is 15 to 98 mol% with respect to all the repeating units of the resin (A). Is preferable, 25 to 85 mol% is more preferable, and 35 to 80 mol% is further preferable.

-Repeating unit b4 (repeating unit b5, repeating unit b6)
It is also preferable that the repeating unit b1 includes the repeating unit b4.
That is, the resin (A) preferably has the repeating unit b4.
The repeating unit b4 is a repeating unit other than the repeating unit a1, and is a lactone group, a sulton group, a carbonate group, a hydroxyl group (which may be a non-aromatic hydroxyl group or an aromatic hydroxyl group), a sulfonamide group, an amide group, and a carboxylic acid. A repeating unit having a group having one or more specific groups selected from the group consisting of a group and a photoacid generating group.
As for the group having the specific group, the "group having the specific group" may be the specific group itself, or the specific group may be contained in a part of the "group having the specific group".
The repeating unit b4 is preferably different from the repeating unit b2 and / or the repeating unit b3.

The repeating unit b4 is preferably a repeating unit represented by the general formula (B0).

In the general formula (B0), X represents a hydrogen atom, an alkyl group, or a halogen atom other than a fluorine atom.
The alkyl group may be linear or branched. The alkyl group preferably has 1 to 10 carbon atoms. The substituent of the alkyl group is preferably a hydroxyl group or a halogen atom. When the alkyl group has a substituent, it is preferable that the alkyl group has only a hydroxyl group and / or a halogen atom as the substituent. The alkyl group is preferably -CH ₃ .
In the general formula (B0), ^{L B} represents a single bond or -COO-. The carbonyl carbon in -COO- is preferably directly attached to the main chain of the repeating unit.
In the general formula (B0), ^RB0 represents a hydrogen atom or a group Y.
^{However, R B0,} when represents a hydrogen atom, ^{L B} represents ^-COO-, overall -L B ^{-R B0} represents -COOH.
Group Y consists of a group consisting of a lactone group, a sulton group, a carbonate group, a hydroxyl group (which may be a non-aromatic hydroxyl group or an aromatic hydroxyl group), a sulfonamide group, an amide group, a carboxylic acid group, and a photoacid generating group. A group having one or more specific groups to be selected, not a elimination group.
Moreover, "in not leaving" group Y is, specifically, when ^{L B} is -COO-, in ^{^{-COO-R B0,} R B0} (group Y) is a polar group (carboxylic acid It is intended to be a non-leaving group that protects the group.
The "group that is not a leaving group" means a group that is not the "leaving group that is eliminated by the action of an acid" described with respect to the repeating unit a2. Specifically, the "group that is not a leaving group" does not correspond to the group represented by the above formulas (Y1) to (Y4).
^{R B0} in the formula (B0) is, for example, the same as ^{R Q} in the repeating unit a4.

Above all, the repeating unit b4 preferably includes the repeating unit b5.
That is, the resin (A) preferably has the repeating unit b5.
The repeating unit b5 is a repeating unit represented by the general formula (B1).

X in the general formula (B1) represents a hydrogen atom, an alkyl group, or a halogen atom other than a fluorine atom, and is the same as X in the general formula (B0).
In the general formula (B1), ^{L B} represents a single bond or -COO-. The carbonyl carbon in -COO- is preferably directly attached to the main chain of the repeating unit.
In the general formula (B1), ^RB1 represents the group Z.
Group Z consists of a group consisting of a lactone group, a sulton group, a carbonate group, a hydroxyl group (which may be a non-aromatic hydroxyl group or an aromatic hydroxyl group), a sulfonamide group, an amide group, a carboxylic acid group, and a photoacid generating group. It is a group having one or more specific groups to be selected and a fluorine atom, and is not a elimination group.
Moreover, "in not leaving" group Z is, specifically, when ^{L B} is -COO-, in ^{^{-COO-R B1,} R B1} (group Z) is a polar group (carboxylic acid It is intended to be a non-leaving group that protects the group.
The "group that is not a leaving group" means a group that is not the "leaving group that is eliminated by the action of an acid" described with respect to the repeating unit a2. Specifically, the "group that is not a leaving group" does not correspond to the group represented by the above formulas (Y1) to (Y4).
^{R B1} in general formula (B1) (group Z) is, for example, the same as ^{R Q} in the repeating unit a5.

Among them, it is also preferable that the repeating unit b5 includes a repeating unit b6 having a group Z having a hexafluoropropanol group (a group represented by "-C (CF ₃ ) ₂ OH").
That is, the resin (A) preferably has the repeating unit b6.
More specifically, repeating units b6, in the repeating unit represented by formula (B1), a repeating unit R ^B1 is a group Z with a hexafluoropropanol group.
The repeating unit b6 is also a form of the repeating unit b4 and the repeating unit b5.

When the resin (A) has a repeating unit b4 (preferably a repeating unit b5, more preferably a repeating unit b6), the content thereof is preferably 1 to 80 mol% with respect to all the repeating units of the resin (A). 3 to 70 mol% is more preferable, and 5 to 65 mol% is further preferable.
The repeating unit a4 may be used alone or in combination of two or more.
The total content of the repeating unit a4 and the repeating unit b4 in the resin (A) is preferably 1 to 80 mol%, more preferably 3 to 70 mol%, based on all the repeating units of the resin (A). More preferably, it is 5 to 65 mol%.

・・ Repeat unit b4-0
The repeating unit b4 may be a repeating unit b4-0 having a carboxylic acid group as a specific group.
As one form of such a repeating unit b4-0, a repeating unit in which the fluorine atom directly bonded to the main chain of the repeating unit in the repeating unit a4-0 is replaced with X in the general formula (B0) can be mentioned.
The preferable content of the repeating unit b4-0 is the same as that of the repeating unit a4-0.
The total content of the repeating unit a4-0 and the repeating unit b4-0 in the resin (A) is preferably 1 to 30 mol%, preferably 2 to 20 mol%, based on all the repeating units of the resin (A). Is more preferable, and 3 to 15 mol% is further preferable.

・・ Repeat unit b4-1
A repeating unit having at least one selected from the group consisting of a lactone group, a sultone group, and a carbonate group as a specific group (preferably as a specific group of the above-mentioned group Y or group Z). In some cases, such a repeating unit b4 is also referred to as a repeating unit b4-1.
In the repeating unit b4-1 having a lactone group, the lactone group contains one hydrogen atom from the ring member atom of the lactone structure represented by any of the above general formulas (LC1-1) to (LC1-22). The lactone group extracted as described above is preferable. Further, one of the ring member atoms of the lactone structure may or may not be the main chain of the repeating unit. The two ring-membered atoms of the lactone structure may or may not be the main chain of the repeating unit.
In the repeating unit b4-1 having a sultone group, the sultone group contains one hydrogen atom from the ring-membered atom of the sultone structure represented by any of the above general formulas (SL1-1) to (SL1-3). The sultone group obtained by pulling out the above is preferable. Further, one ring member atom of the sultone structure may or may not be the main chain of the repeating unit. The two ring-membered atoms of the sultone structure may or may not be the main chain of the repeating unit.
In the repeating unit b4-1 having a carbonate group, the carbonate group is formed by extracting one or more hydrogen atoms from the ring-membered atom of the cyclic carbonate structure represented by any of the above general formula (CC-1). A sultone group is preferred. Further, one ring-membered atom of the cyclic carbonate structure may or may not be the main chain of the repeating unit. The two ring-membered atoms of the cyclic carbonate structure may or may not be the main chain of the repeating unit.

As a form of the repeating unit b4-1, the main chain of the repeating unit in the repeating unit a4-1 (the repeating unit represented by the general formula (A3), the repeating unit represented by the general formula (A4), etc.) Examples thereof include repeating units in which the directly bonded fluorine atom is replaced with X in the general formula (B0).
The repeating unit b4-1 is preferably different from the repeating unit b4-0.
The preferable content of the repeating unit b4-1 is the same as that of the repeating unit a4-1.
The total content of the repeating unit a4-1 and the repeating unit b4-1 in the resin (A) is preferably 3 to 60 mol%, preferably 5 to 50 mol%, based on all the repeating units of the resin (A). Is more preferable, and 7 to 45 mol% is further preferable.

・・ Repeat unit b4-2
The repeating unit b4 is a repeating unit having a non-aromatic hydroxyl group as a specific group (preferably as the specific group of the above-mentioned group Y or group Z), and the above-mentioned non-aromatic hydroxyl group is contained in the fluorinated alcohol group. When it is a hydroxyl group other than a hydroxyl group, such a repeating unit b4 is also referred to as a repeating unit b4-2.
The repeating unit b4-2 is preferably different from the repeating unit b4-0 and / or the repeating unit b4-1.
As one form of such a repeating unit b4-2, in the repeating unit a4-2 (repeating unit represented by the general formula (A5), etc.), the fluorine atom directly bonded to the main chain is contained in the general formula (B0). replaces the X, -COO- directly bonded to the main chain, the general formula (B0) repeating units replaced by ^{L B} in the like.
The preferable content of the repeating unit b4-2 is the same as that of the repeating unit a4-2.
The total content of the repeating unit a4-2 and the repeating unit b4-2 in the resin (A) is preferably 3 to 60 mol%, preferably 5 to 50 mol%, based on all the repeating units of the resin (A). Is more preferable, and 10 to 45 mol% is further preferable.

・・ Repeat unit b4-3
The repeating unit b4 is a repeating unit having a non-aromatic hydroxyl group as a specific group (preferably as the specific group of the above-mentioned group Y or group Z), and the above-mentioned non-aromatic hydroxyl group is contained in the fluorinated alcohol group. In the case of a hydroxyl group, such a repeating unit b4 is also referred to as a repeating unit b4-3.
The repeating unit b4-3 is preferably different from the repeating unit b4-0, the repeating unit b4-1, and / or the repeating unit b4-2.
The repeating unit b4-3 preferably corresponds to the repeating unit b6.
As one form of such a repeating unit b4-3, in the repeating unit a4-3 (repeating unit represented by the general formula (A6), etc.), the fluorine atom directly bonded to the main chain is contained in the general formula (B0). of replaces X, the main chain bonded directly to a -COO- are repeating units replaced by ^{L B} in the general formula (B0) and the like.
The preferable content of the repeating unit b4-3 is the same as that of the repeating unit a4-3.
The total content of the repeating unit a4-3 and the repeating unit b4-3 in the resin (A) is preferably 3 to 50 mol%, preferably 5 to 40 mol%, based on all the repeating units of the resin (A). Is more preferable, and 10 to 35 mol% is further preferable.

・・ Repeat unit b4-4
When the repeating unit b4 is a repeating unit having a photoacid generating group as a specific group (preferably as the specific group of the above-mentioned group Y or group Z), such a repeating unit b4 is also referred to as a repeating unit b4-4. ..
The repeating unit b4-4 preferably corresponds to the repeating unit b5.
The repeating unit b4-4 is preferably different from the repeating unit b4-0, the repeating unit b4-1, the repeating unit b4-2, and / or the repeating unit b4-3.
As one form of such a repeating unit b4-4, in the repeating unit a4-4 (repeating unit represented by the general formula (A7), etc.), the fluorine atom directly bonded to the main chain is contained in the general formula (B0). replaces the X, -COO- directly bonded to the main chain, the general formula (B0) repeating units replaced by ^{L B} in the like.
The preferable content of the repeating unit b4-4 is the same as that of the repeating unit a4-4.
The total content of the repeating unit a4-4 and the repeating unit b4-4 in the resin (A) is preferably 3 to 40 mol%, preferably 5 to 25 mol%, based on all the repeating units of the resin (A). Is more preferable, and 7 to 20 mol% is further preferable.

・・ Repeat unit b4-5
When the repeating unit b4 is a repeating unit having a group having an aromatic hydroxyl group as a specific group (preferably as the specific group of the above-mentioned group Y or group Z), such a repeating unit b4 is referred to as the repeating unit b4-. Also called 5.
The repeating unit b4-5 is preferably different from the repeating unit b4-0, the repeating unit b4-1, the repeating unit b4-2, the repeating unit b4-3, and / or the repeating unit b4-4.
The repeating unit b4-5 is preferably a turning unit represented by the general formula (B2).

In the general formula (B2), X represents a hydrogen atom, an alkyl group, or a halogen atom other than a fluorine atom, and is the same as X in the general formula (B0).

In the general formula (B2), X ₄ represents a single bond, -COO-, or -CONR _64- , and R ₆₄ is a hydrogen atom or an alkyl group (which may be linear or branched, preferably having a number of carbon atoms). Represents 1 to 5). The carbonyl carbon in -COO- is preferably directly attached to the main chain of the repeating unit.

In the general formula (B2), L ₄ represents a single bond or an alkylene group (either linear or branched chain, preferably 1 to 20 carbon atoms).

In the general formula (B2), Ar ₄ represents an (n + 1) -valent aromatic ring group.
The aromatic ring group is an arylene group having 6 to 18 carbon atoms such as a benzene ring group, a naphthalene ring group, and an anthracene ring group, or a thiophene ring group, a furan ring group, a pyrrole ring group, a benzothiophene ring group, and a benzofuran. Aromatic ring groups containing heterocycles such as a ring group, a benzopyrol ring group, a triazine ring group, an imidazole ring group, a benzoimidazole ring group, a triazole ring group, a thiadiazol ring group, and a thiazole ring group are preferable, and a benzene ring group is preferable. More preferred.

In the general formula (B2), n represents an integer of 1 to 5.
The (n + 1) -valent aromatic ring group may further have a substituent.

Examples of the substituent that the above-mentioned alkyl group of R ₆₄ , alkylene group of L ₄ and Ar ₄ (n + 1) -valent aromatic ring group can have include a halogen atom (preferably a fluorine atom) and a methoxy group. Examples thereof include an alkoxy group such as an ethoxy group, a hydroxyethoxy group, a propoxy group, a hydroxypropoxy group and a butoxy group; an aryl group such as a phenyl group; and the like. Further, examples of the substituent that the (n + 1) -valent aromatic ring group of Ar ₄ can have include an alkyl group (which may be linear or branched, preferably having 1 to 20 carbon atoms).

Hereinafter, specific examples of the repeating unit b4-5 will be shown, but the present invention is not limited thereto. In the formula, a represents 1 or 2.

Among the above repeating units, the repeating units specifically described below are preferable. In the formula, R represents a hydrogen atom or a methyl group, and a represents an integer of 1 to 3.

When the resin (A) has the repeating unit b4-5, the content thereof is preferably 3 to 70 mol%, more preferably 10 to 65 mol%, and 7 to 7 to all the repeating units of the resin (A). 60 mol% is more preferred.
The repeating unit b4-5 may be used alone or in combination of two or more.

The resin (A) can be synthesized according to a conventional method (for example, radical polymerization).
As a polystyrene conversion value by the GPC method, the weight average molecular weight of the resin (A) is preferably 1,000 to 200,000, more preferably 3,000 to 20,000, and even more preferably 4,500 to 15,000. When the weight average molecular weight of the resin (A) is set to 1,000 to 200,000, deterioration of heat resistance and dry etching resistance can be prevented, and further, deterioration of developability and high viscosity can be prevented. It is possible to prevent the film property from deteriorating.
The dispersity (molecular weight distribution) of the resin (A) is usually 1 to 5, preferably 1 to 3, more preferably 1.2 to 3.0, and even more preferably 1.2 to 2.0. The smaller the degree of dispersion, the better the resolution and the resist shape, the smoother the side wall of the resist pattern, and the better the roughness.

The resin (A) preferably has a high glass transition temperature (Tg) from the viewpoint of suppressing excessive diffusion of generated acid and / or pattern collapse during development. Tg is preferably over 90 ° C., more preferably over 100 ° C., even more preferably over 110 ° C., and particularly preferably over 125 ° C. In addition, since excessively high Tg causes a decrease in the dissolution rate in a developing solution, Tg is preferably 400 ° C. or lower, more preferably 350 ° C. or lower.
In the present specification, the glass transition temperature (Tg) of the polymer such as the resin (A) is calculated by the following method. First, the Tg of a homopolymer composed of only each repeating unit contained in the polymer is calculated by the Bicerano method. Hereinafter, the calculated Tg is referred to as "repeating unit Tg". Next, the mass ratio (%) of each repeating unit to all the repeating units in the polymer is calculated. Next, Tg at each mass ratio is calculated using the Fox formula (described in Materials Letters 62 (2008) 3152, etc.), and the sum of them is used as the Tg (° C.) of the polymer.
The Bicerano method is described in the Precision of developers, Marcel Dekker Inc, New York (1993) and the like. Further, the calculation of Tg by the Bicerano method can be performed using the polymer physical property estimation software MDL Polymer (MDL Information Systems, Inc.).

In order to increase the Tg of the resin (A) above 90 ° C., it is preferable to reduce the motility of the main chain of the resin (A). Examples of the method for reducing the motility of the main chain of the resin (A) include the following methods (a) to (e).
(A) Introduction of a bulky substituent into the main chain (b) Introduction of a plurality of substituents into the main chain (c) Introduction of a substituent that induces an interaction between the resins (A) in the vicinity of the main chain ( d) Main chain formation in a cyclic structure (e) Connection of a cyclic structure to the main chain The resin (A) preferably has a repeating unit in which the Tg of the homopolymer is 130 ° C. or higher.
The type of repeating unit having a homopolymer Tg of 130 ° C. or higher is not particularly limited, and any repeating unit having a homopolymer Tg of 130 ° C. or higher calculated by the Bicerano method may be used. Depending on the type of the functional group in the repeating unit represented by the formulas (A) to (E) described later, the homopolymer corresponds to the repeating unit having a Tg of 130 ° C. or higher.

As a specific means of achieving the above (a), for example, a method of introducing a repeating unit represented by the formula (A) into the resin (A) can be mentioned.

Formulas (A) and _RA represent groups having a polycyclic structure. R _x represents a hydrogen atom, a methyl group, or an ethyl group. The group having a polycyclic structure is a group having a plurality of ring structures, and the plurality of ring structures may or may not be condensed.
Examples of the repeating unit represented by the formula (A) include the following repeating units.

In the above formula, R represents a hydrogen atom, a methyl group, or an ethyl group.
Ra is a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, an alkenyl group, a hydroxyl group, an alkoxy group, an acyloxy group, a cyano group, a nitro group, an amino group, a halogen atom, and an ester group (-OCOR'''. Alternatively, -COOR "": R "" represents an alkyl group having 1 to 20 carbon atoms or a fluorinated alkyl group) or a carboxylic acid group. The alkyl group, the cycloalkyl group, the aryl group, the aralkyl group, and the alkenyl group may each have a substituent. Further, the hydrogen atom bonded to the carbon atom in the group represented by Ra may be replaced with a fluorine atom or an iodine atom.
In addition, R'and R'' are independently alkyl groups, cycloalkyl groups, aryl groups, aralkyl groups, alkenyl groups, hydroxyl groups, alkoxy groups, asyloxy groups, cyano groups, nitro groups, amino groups, halogen atoms, respectively. It represents an ester group (-OCOR ″ or −COOR ′ ″: R ″ is an alkyl group having 1 to 20 carbon atoms or a fluorinated alkyl group) or a carboxylic acid group. The alkyl group, the cycloalkyl group, the aryl group, the aralkyl group, and the alkenyl group may each have a substituent. Further, the hydrogen atom bonded to the carbon atom in the group represented by R'and R'may be replaced with a fluorine atom or an iodine atom.
L represents a single bond or a divalent linking group. Examples of the divalent linking group include -COO-, -CO-, -O-, -S-, -SO-, -SO _2- , an alkylene group, a cycloalkylene group, an alkenylene group, and a plurality of these. Examples thereof include a linking group in which is linked.
m and n each independently represent an integer of 0 or more. The upper limits of m and n are not particularly limited, but are often 2 or less and more often 1 or less.

As a specific means of achieving the above (b), for example, a method of introducing a repeating unit represented by the formula (B) into the resin (A) can be mentioned.

In the formula (B), R _b1 to R _b4 independently represent a hydrogen atom or an organic group, and at least two or more of R _b1 to R _b4 represent an organic group.
Further, when at least one of the organic groups is a group in which the ring structure is directly linked to the main chain in the repeating unit, the types of other organic groups are not particularly limited.
Further, when none of the organic groups is a group in which the ring structure is directly linked to the main chain in the repeating unit, at least two or more organic groups have three or more constituent atoms excluding hydrogen atoms. It is a substituent.

Examples of the repeating unit represented by the formula (B) include the following repeating units.

In the above formula, R independently represents a hydrogen atom or an organic group. Examples of the organic group include organic groups such as an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, and an alkenyl group, which may have a substituent.
R'is independently an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, an alkenyl group, a hydroxyl group, an alkoxy group, an acyloxy group, a cyano group, a nitro group, an amino group, a halogen atom, and an ester group (-OCOR'. 'Or-COOR'': R'' represents an alkyl group having 1 to 20 carbon atoms or a fluorinated alkyl group) or a carboxylic acid group. The alkyl group, the cycloalkyl group, the aryl group, the aralkyl group, and the alkenyl group may each have a substituent. Further, the hydrogen atom bonded to the carbon atom in the group represented by R'may be replaced with a fluorine atom or an iodine atom.
m represents an integer of 0 or more. The upper limit of m is not particularly limited, but it is often 2 or less, and more often 1 or less.

As a specific means of achieving the above (c), for example, a method of introducing a repeating unit represented by the formula (C) into the resin (A) can be mentioned.

In the formula (C), R _c1 to R _c4 each independently represent a hydrogen atom or an organic group, and at least one of R _c1 to R _c4 is a hydrogen-bonding hydrogen within 3 atoms from the main chain carbon. It is a group having an atom. Above all, in order to induce the interaction between the main chains of the resin (A), it is preferable to have hydrogen-bonding hydrogen atoms within 2 atoms (closer to the main chain).

Examples of the repeating unit represented by the formula (C) include the following repeating units.

In the above formula, R represents an organic group. Examples of the organic group include an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, an alkenyl group, and an ester group (-OCOR or -COOR: R has 1 to 20 carbon atoms, which may have a substituent). Alkyl group or fluorinated alkyl group) and the like.
R'represents a hydrogen atom or an organic group. Examples of the organic group include an organic group such as an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, and an alkenyl group. The hydrogen atom in the organic group may be replaced with a fluorine atom or an iodine atom.

As a specific means for achieving the above (d), for example, a method of introducing a repeating unit represented by the formula (D) into the resin (A) can be mentioned.
When the resin (A) contains a repeating unit represented by the formula (D), the content thereof is preferably 1 to 50 mol%, preferably 3 to 40 mol%, based on all the repeating units of the resin (A). More preferably, 5 to 30 mol% is further preferable.

In the formula (D), "cyclic" represents a group forming a main chain with a cyclic structure. The number of constituent atoms of the ring is not particularly limited.

Examples of the repeating unit represented by the formula (D) include the following repeating units.

In the above formula, R is independently a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, an alkenyl group, a hydroxyl group, an alkoxy group, an acyloxy group, a cyano group, a nitro group, an amino group, a halogen atom, respectively. An ester group (-OCOR "or -COOR": R "is an alkyl group having 1 to 20 carbon atoms or a fluorinated alkyl group) or a carboxylic acid group. The alkyl group, the cycloalkyl group, the aryl group, the aralkyl group, and the alkenyl group may each have a substituent. Further, the hydrogen atom bonded to the carbon atom in the group represented by R may be substituted with a fluorine atom or an iodine atom.
In the above formula, R'is independently an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, an alkenyl group, a hydroxyl group, an alkoxy group, an acyloxy group, a cyano group, a nitro group, an amino group, a halogen atom and an ester group. (-OCOR "or -COOR": R "is an alkyl group having 1 to 20 carbon atoms or a fluorinated alkyl group) or a carboxylic acid group. The alkyl group, the cycloalkyl group, the aryl group, the aralkyl group, and the alkenyl group may each have a substituent. Further, the hydrogen atom bonded to the carbon atom in the group represented by R'may be replaced with a fluorine atom or an iodine atom.
m represents an integer of 0 or more. The upper limit of m is not particularly limited, but it is often 2 or less, and more often 1 or less.

As a specific means for achieving the above (e), for example, a method of introducing a repeating unit represented by the formula (E) into the resin (A) can be mentioned.
When the resin (A) contains a repeating unit represented by the formula (E), the content thereof is preferably 1 to 50 mol%, preferably 3 to 40 mol%, based on all the repeating units of the resin (A). More preferably, 5 to 30 mol% is further preferable.

In formula (E), Re independently represents a hydrogen atom or an organic group. Examples of the organic group include an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, an alkenyl group and the like, which may have a substituent.
"Cyclic" is a cyclic group containing a carbon atom in the main chain. The number of atoms contained in the cyclic group is not particularly limited.

Examples of the repeating unit represented by the formula (E) include the following repeating units.

In the above formula, R is independently a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, and an alkenyl group, a hydroxyl group, an alkoxy group, an acyloxy group, a cyano group, a nitro group, an amino group, and a halogen. It represents an atom, an ester group (-OCOR "or -COOR": R "is an alkyl group having 1 to 20 carbon atoms or a fluorinated alkyl group), or a carboxylic acid group. The alkyl group, the cycloalkyl group, the aryl group, the aralkyl group, and the alkenyl group may each have a substituent. Further, the hydrogen atom bonded to the carbon atom in the group represented by R may be substituted with a fluorine atom or an iodine atom.
R'is independently a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, and an alkenyl group, a hydroxyl group, an alkoxy group, an acyloxy group, a cyano group, a nitro group, an amino group, a halogen atom, and an ester. A group (-OCOR "or -COOR": R "is an alkyl group having 1 to 20 carbon atoms or a fluorinated alkyl group) or a carboxylic acid group. The alkyl group, the cycloalkyl group, the aryl group, the aralkyl group, and the alkenyl group may each have a substituent. Further, the hydrogen atom bonded to the carbon atom in the group represented by R'may be replaced with a fluorine atom or an iodine atom.
m represents an integer of 0 or more. The upper limit of m is not particularly limited, but it is often 2 or less, and more often 1 or less.
Further, in the formula (E-2), the formula (E-4), the formula (E-6), and the formula (E-8), the two Rs may be bonded to each other to form a ring.

In the resist composition, the content of the resin (A) is preferably 50 to 99.9% by mass, more preferably 60 to 99.0% by mass, based on the total solid content.
Further, the resin (A) may be used alone or in combination of two or more.

<(B) Compound that generates acid by irradiation with active light or radiation>
The resist composition may contain a compound (photoacid generator) that generates an acid by irradiation with active light or radiation. The photoacid generator is a compound that generates an acid upon exposure (preferably exposure to EUV light).
The photoacid generator may be in the form of a low molecular weight compound or may be incorporated in a part of the polymer. Further, the form of the low molecular weight compound and the form incorporated in a part of the polymer may be used in combination.
When the photoacid generator is in the form of a low molecular weight compound, the molecular weight is preferably 3000 or less, more preferably 2000 or less, still more preferably 1000 or less.
When the photoacid generator is in the form of being incorporated in a part of the polymer, it may be incorporated in a part of the resin (A) or may be incorporated in a resin different from the resin (A).
In the present invention, the photoacid generator is preferably in the form of a low molecular weight compound.
The photoacid generator is not particularly limited, and among them, a compound that generates an organic acid by irradiation with EUV light is preferable, and a photoacid generator having a fluorine atom or an iodine atom in the molecule is more preferable.
Examples of the organic acid include sulfonic acid (aliphatic sulfonic acid, aromatic sulfonic acid, camphor sulfonic acid, etc.), carboxylic acid (aliphatic carboxylic acid, aromatic carboxylic acid, aralkylcarboxylic acid, etc.), carbonyl. Examples thereof include sulfonylimide acid, bis (alkylsulfonyl) imide acid, and tris (alkylsulfonyl) methidoic acid.

Although the volume of the acid generated from the photoacid generator is not particularly limited, and suppress the diffusion of the non-exposed portion of the acid generated by exposure, from the viewpoint of improving the resolution, 240 Å ³ or more are preferred, 305A ³ The above is more preferable, 350 Å ³ or more is further preferable, and 400 Å ³ or more is particularly preferable.
Incidentally, from the viewpoint of solubility in sensitivity or coating solvent, the volume of the acid generated by the photoacid generator is preferably 1500 Å ³ or less, more preferably 1000 Å ³ or less, 700 Å ³ or less is more preferable.
The value of the volume is obtained by using "WinMOPAC" manufactured by Fujitsu Limited. In calculating the volume value, first, the chemical structure of the acid according to each example is input, and then each acid is calculated by the molecular force field using the MM (Molecular Mechanics) 3 method with this structure as the initial structure. The most stable conformation of each acid can be determined, and then the molecular orbital calculation using the PM (Parameterized Model number) 3 method can be performed on these most stable conformations to calculate the "accessible volume" of each acid.

The structure of the acid generated by the photoacid generator is not particularly limited, but the acid generated by the photoacid generator and the resin (A) are in that the diffusion of the acid is suppressed and the resolution is improved. It is preferable that the interaction is strong. From this point, when the acid generated by the photoacid generator is an organic acid, for example, a sulfonic acid group, a carboxylic acid group, a carbonylsulfonylimide acid group, a bissulfonylimide acid group, a trissulfonylmethidoic acid group, etc. It is preferable to have a polar group in addition to the organic acid group of.
Examples of the polar group include an ether group, an ester group, an amide group, an acyl group, a sulfo group, a sulfonyloxy group, a sulfonamide group, a thioether group, a thioester group, a urea group, a carbonate group, a carbamate group, a hydroxyl group, and a mercapto. The group is mentioned.
The number of polar groups contained in the generated acid is not particularly limited, and is preferably 1 or more, and more preferably 2 or more. However, from the viewpoint of suppressing excessive development, the number of polar groups is preferably less than 6, and more preferably less than 4.

The photoacid generator is preferably a photoacid generator that generates the acids exemplified below. In addition, the calculated value of the volume is added to a part of the example (unit: Å ³ ).

The photoacid generator is preferably a photoacid generator having anions and cations because the effect of the present invention is more excellent.

(Compound represented by the general formula (PA-1))
The photoacid generator preferably contains a compound represented by the general formula (PA-1).

In formula ^{(PA-1), A} 1 and ^{A 2} are each independently, _-SO 2 -R ^P, or represents ^{-CO-R P.} R ^P represents an organic group.
R ^P present two in the general formula (PA-1) may be the same or different.
Formula number of carbon atoms in ^{R P} present two to (PA-1) in each independently, preferably 1 to 25, more preferably from 1 to 15.
The number of the general formula (PA-1) atoms excluding two hydrogen atoms of the present ^{R P} during each independently 2 to 30, and more preferably from 4 to 20.
R ^P is a group represented by the general formula (RF) is preferred.
-L ^RF- R ^RF (RF)

In the general formula (RF), ^LRF represents a single bond or a divalent linking group.
Examples of the divalent linking group include -COO-, -CONH-, -CO-, -O-, -S-, -SO-, -SO _2- , and an alkylene group (linear or branched chain). It may be preferably 1 to 6 carbon atoms), a cycloalkylene group (preferably 3 to 15 carbon atoms), an alkenylene group (may be linear or branched chain, preferably 2 to 6 carbon atoms), and these. A divalent linking group obtained by combining a plurality of the above can be mentioned.
Further, as the substituent that can be possessed when these divalent linking groups are possible, a halogen atom is preferable, and a fluorine atom is more preferable. For example, it is also preferable that the alkylene group (including an alkylene group that can be contained in a divalent linking group in which a plurality of them are combined) is a perfluoroalkylene group.
The divalent linking group is preferably -alkylene group-COO- or -alkylene group-SO _2- . -The alkylene group-COO- and the -alkylene group-SO _2- preferably have an alkylene group on the N ^- side.

In the general formula (RF), R ^RF represents a cycloalkyl group or an alkyl group.
When R ^RF is a cycloalkyl group, the cycloalkyl group may be monocyclic or polycyclic.
The cycloalkyl group preferably has 3 to 15 carbon atoms, and more preferably 5 to 10 carbon atoms.
Examples of the cycloalkyl group include a norbornyl group, a decalynyl group, and an adamantyl group.
The substituent that the cycloalkyl group may have is preferably an alkyl group (which may be linear or branched, preferably having 1 to 5 carbon atoms). It is also preferable that the cycloalkyl group has no other substituent.
One or more of the carbon atoms which are ring member atoms of the cycloalkyl group may be replaced with carbonyl carbon atoms and / or heteroatoms. For example, the carbon atom (-CH <) bonded to ^LRF in the cycloalkyl group may be replaced with the nitrogen atom (-N <).
When R ^RF is an alkyl group, the alkyl group may be linear or branched.
The alkyl group preferably has 1 to 10 carbon atoms, and more preferably 1 to 5 carbon atoms.
The substituent that the alkyl group may have is preferably a cycloalkyl group, a fluorine atom, or a cyano group. It is also preferable that the alkyl group does not have a substituent other than these.
Examples of the cycloalkyl group as the substituent include, for example, the cycloalkyl group described in the case where R ^RF is a cycloalkyl group.
When the alkyl group has a fluorine atom as the substituent, the alkyl group may or may not be a perfluoroalkyl group. When the alkyl group has a fluorine atom as the substituent, it is also preferable that a part or all of the alkyl group is a perfluoromethyl group.

In formula (PA-1), - two ^{R P} included in ^"A 1 ^-N -A ² 'are bonded to each other may form a ring.

In the general formula (PA-1), M ⁺ represents a cation.
The M ⁺ cation is preferably an organic cation.
The organic cations are preferably cations represented by the general formula (ZaI) (cations (ZaI)) or cations represented by the general formula (ZaII) (cations (ZaII)) independently of each other.

In the above general formula (ZaI)
R ²⁰¹ , R ²⁰² , and R ²⁰³ each independently represent an organic group.
The carbon number of the organic group as R ²⁰¹ , R ²⁰² , and R ²⁰³ is usually 1 to 30, preferably 1 to 20. Further, 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 group, an amide group, or a carbonyl group. The two of the group formed by bonding of the R ²⁰¹ ~ ^{R 203,} for example, an alkylene group (e.g., butylene, pentylene), _{_{_{and, -CH 2 -CH 2 -O-CH}}} 2 -CH 2 - Can be mentioned.

Examples of the cation in the general formula (ZaI) include a cation (ZaI-1), a cation (ZaI-2), and a cation represented by the general formula (ZaI-3b) (cation (ZaI-3b)), which will be described later. In addition, a cation (cation (ZaI-4b)) represented by the general formula (ZaI-4b) can be mentioned.

First, the cation (ZaI-1) will be described.
The cation (ZaI-1) is an aryl sulfonium cation in which at least one of R ²⁰¹ to R ²⁰³ of the above general formula (ZaI) is an aryl group.
As the aryl sulfonium cation, all of R ₂₀₁ to R ₂₀₃ may be an aryl group, or a part of R ₂₀₁ to R ₂₀₃ may be an aryl group and the rest may be an alkyl group or a cycloalkyl group.
Further, one of R ²⁰¹ to R ²⁰³ may be an aryl group, and the remaining two of R ²⁰¹ to R ²⁰³ may be bonded to form a ring structure, and an oxygen atom and a sulfur atom may be formed in the ring. It may contain an ester group, an amide group, or a carbonyl group. As a group formed by bonding two of R ²⁰¹ to R ²⁰³ , for example, one or more methylene groups are substituted with an oxygen atom, a sulfur atom, an ester group, an amide group, and / or a carbonyl group. also an alkylene group (e.g., butylene group, pentylene group, or _{_{_{-CH 2 -CH 2 -O-CH 2}}} -CH 2 -) and the like.
Examples of the aryl sulfonium cation include a triaryl sulfonium cation, a diarylalkyl sulfonium cation, an aryl dialkyl sulfonium cation, a diarylcycloalkyl sulfonium cation, and an aryl dicycloalkyl sulfonium cation.

The aryl group contained in the arylsulfonium cation 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 residues, furan residues, thiophene residues, indole residues, benzofuran residues, benzothiophene residues and the like. When the aryl sulfonium cation 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 cation has as needed is a linear alkyl group having 1 to 15 carbon atoms, a branched alkyl group having 3 to 15 carbon atoms, or a branched alkyl group having 3 to 15 carbon atoms. Fifteen cycloalkyl groups are preferred, and examples thereof include methyl group, ethyl group, propyl group, n-butyl group, sec-butyl group, t-butyl group, cyclopropyl group, cyclobutyl group, cyclohexyl group and the like.

The aryl group, alkyl group, and substituent which the cycloalkyl group may have of R ²⁰¹ to R ²⁰³ are independently an alkyl group (for example, 1 to 15 carbon atoms) and a cycloalkyl group (for example, carbon number of carbon atoms). 3 to 15), aryl group (for example, 6 to 14 carbon atoms), alkoxy group (for example, 1 to 15 carbon atoms), cycloalkyl alkoxy group (for example, 1 to 15 carbon atoms), halogen atom, hydroxyl group, or phenylthio group. preferable.
If possible, the substituent may further have a substituent. For example, even if the alkyl group has a halogen atom as a substituent and is an alkyl halide group such as a trifluoromethyl group. Good.

Next, the cation (ZaI-2) will be described.
The cation (ZaI-2) is a cation in which R ²⁰¹ to R ²⁰³ in the formula (ZaI) independently represent an organic group having no aromatic ring. Here, the aromatic ring also includes an aromatic ring containing a hetero atom.
The organic group having no aromatic ring as R ²⁰¹ to R ²⁰³ generally has 1 to 30 carbon atoms, and 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, and are linear or branched 2-oxoalkyl groups, 2-oxocycloalkyl groups, or Alkoxycarbonylmethyl groups are more preferred, and linear or branched 2-oxoalkyl groups are even more preferred.

Examples of the alkyl group and cycloalkyl group of R ²⁰¹ to R ²⁰³ include a linear alkyl group having 1 to 10 carbon atoms or a branched chain alkyl group having 3 to 10 carbon atoms (for example, a methyl group, an ethyl group, and a propyl group). Groups, butyl groups, and pentyl groups), and cycloalkyl groups having 3 to 10 carbon atoms (for example, cyclopentyl groups, cyclohexyl groups, and norbornyl groups).
R ²⁰¹ to R ²⁰³ may be further substituted with a halogen atom, an alkoxy group (for example, 1 to 5 carbon atoms), a hydroxyl group, a cyano group, or a nitro group.

Next, the cation (ZaI-3b) will be described.
The cation (ZaI-3b) is a cation represented by the following general formula (ZaI-3b).

In the general formula (ZaI-3b),
R _1c to R _5c are independently hydrogen atom, alkyl group, cycloalkyl group, aryl group, alkoxy group, aryloxy group, alkoxycarbonyl group, alkylcarbonyloxy group, cycloalkylcarbonyloxy group, halogen atom, hydroxyl group. , Nitro group, alkylthio group, or arylthio group.
R _6c and R _7c independently represent a hydrogen atom, an alkyl group (t-butyl group, etc.), a cycloalkyl group, a halogen atom, a cyano group, or an aryl group.
R _x and R _y each independently represent 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 _5c and R _6c , R _6c and R _7c , R _5c and R _x , and R _x and R _y may be combined to form a ring, respectively. , This ring may independently contain an oxygen atom, a sulfur atom, a ketone group, an ester bond, or an amide bond.
Examples of the ring include an aromatic or non-aromatic hydrocarbon ring, an aromatic or non-aromatic heterocycle, and a polycyclic condensed ring formed by combining two or more of these rings. The ring includes a 3- to 10-membered ring, preferably a 4- to 8-membered ring, and more preferably a 5- or 6-membered ring.

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 an alkylene group such as a butylene group and a pentylene group. .. The methylene group in the alkylene group may be substituted with a hetero atom such as an oxygen atom.
The group formed by bonding R _5c and R _6c , and R _5c and R _x is preferably a single bond or an alkylene group. Examples of the alkylene group include a methylene group and an ethylene group.

Next, the cation (ZaI-4b) will be described.
The cation (ZaI-4b) is a cation represented by the following general formula (ZaI-4b).

In the general formula (ZaI-4b),
l represents an integer of 0 to 2.
r represents an integer from 0 to 8.
R ₁₃ is a group having a hydrogen atom, a fluorine atom, a hydroxyl group, an alkyl group, an alkoxy group, an alkoxycarbonyl group, or a cycloalkyl group (the cycloalkyl group itself may be used, and a group containing a cycloalkyl group as a part). May be). These groups may have substituents.
R ₁₄ is a hydroxyl group, an alkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylsulfonyl group, a cycloalkylsulfonyl group, or a group having a cycloalkyl group (the cycloalkyl group itself may be a cycloalkyl group). It may be a group containing a group as a part). These groups may have substituents. When a plurality of R ₁₄ are present, each independently represents the above group such as a hydroxyl group.
R ₁₅ independently represents an alkyl group, a cycloalkyl group, or a naphthyl group. These groups may have substituents. Bonded to two R ₁₅ each other may form a ring. When two R ₁₅ are combined to form a ring together, in the ring skeleton, an oxygen atom, or may contain a hetero atom such as nitrogen atom. In one embodiment, two R ₁₅ is an alkylene group, preferably bonded together to form a ring structure.

In the general formula (ZaI-4b), the alkyl groups of R ₁₃ , R ₁₄ and R ₁₅ are linear or branched chain. The alkyl group preferably has 1 to 10 carbon atoms. The alkyl group is more preferably a methyl group, an ethyl group, an n-butyl group, a t-butyl group or the like.

Next, the general formula (ZaII) will be described.
In the general formula (ZaII), R ²⁰⁴ and R ²⁰⁵ each independently represent an aryl group, an alkyl group, or a cycloalkyl group.
The aryl group of R ²⁰⁴ and R ²⁰⁵ is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group. The aryl group of R ²⁰⁴ and R ²⁰⁵ may be an aryl group having a heterocycle having an oxygen atom, a nitrogen atom, a sulfur atom or the like. Examples of the skeleton of the aryl group having a heterocycle include pyrrole, furan, thiophene, indole, benzofuran, and benzothiophene.
The alkyl group and cycloalkyl group of R ²⁰⁴ and R ²⁰⁵ are a linear alkyl group having 1 to 10 carbon atoms or a branched chain alkyl group having 3 to 10 carbon atoms (for example, methyl group, ethyl group, propyl group, butyl group). A group or a pentyl group), or a cycloalkyl group having 3 to 10 carbon atoms (for example, a cyclopentyl group, a cyclohexyl group, or a norbornyl group) is preferable.

The aryl group, alkyl group, and cycloalkyl group of R ²⁰⁴ and R ²⁰⁵ may each independently have a substituent. Examples of the substituents that the aryl group, alkyl group, and cycloalkyl group of R ²⁰⁴ and R ²⁰⁵ may have include an alkyl group (for example, 1 to 15 carbon atoms) and a cycloalkyl group (for example, 3 carbon atoms). -15), aryl groups (for example, 6 to 15 carbon atoms), alkoxy groups (for example, 1 to 15 carbon atoms), halogen atoms, hydroxyl groups, phenylthio groups and the like.

(Compound represented by the general formula (PB))
The photoacid generator also preferably contains a compound represented by the general formula (PB).
M ₁ ⁺ A ^{－－} LB ^－ M ₂ ⁺ (PB)

The compound represented by formula (PB), the structure having a function equivalent to an ordinary photoacid generator - and ( "M _{1 +} ^A ^-" portion corresponding to), a function corresponding to the acid diffusion controller structure with ^- to include both the (part corresponding to "-B M ₂ ^+") in the molecule, a resist film can be constant each occurrence ratio of the structure.
Therefore, the present inventors speculate that even when the resist film is exposed, the amount and diffusion of the acid generated in the resist film tends to be uniform, and the width of the pattern obtained after development is stable.

In formula _{(PB), M} ^{1 +} and _M ^{2 +} each independently represents an organic cation.
M ₁ ⁺ and _M ^{2 +} organic cation, each independently, an organic cation listed in the description of the ^{M +} of the general formula (PA-1) can be used as well.

In the general formula (PB), L represents a divalent organic group.
Examples of the divalent organic group include -COO-, -CONH-, -CO-, an alkylene group (preferably 1 to 6 carbon atoms, which may be linear or branched), and a cycloalkylene group (preferably. 3 to 15 carbon atoms), an alkenylene group (preferably 2 to 6 carbon atoms), and a divalent linking group in which a plurality of these are combined can be mentioned.
One or more of the methylene groups constituting the cycloalkane ring of the cycloalkylene group may be replaced with a carbonyl carbon and / or a hetero atom (oxygen atom or the like).
These divalent linking groups also preferably have a group selected from the group consisting of -O-, -S-, -SO-, and -SO _2- .

Above all, L is preferably a group represented by the following general formula (L).
* A-LA-LB-LC-LD-LE- * B (L)

In the general formula (L), * A represents the connection position with A ⁻ in the general formula (PB).
In the general formula (L), * B represents the connection position with B ⁻ in the general formula (PB).

In the general formula (L), LA represents − (C (R _LA1 ) (R _LA2 )) _XA −.
The XA represents an integer of 1 or more, preferably 1 to 10, and more preferably 1 to 3.
R _LA1 and R _LA2 each independently represent a hydrogen atom or a substituent.
The substituents of R _LA1 and R _LA2 are independently preferably a fluorine atom or a fluoroalkyl group, more preferably a fluorine atom or a perfluoroalkyl group, and further preferably a fluorine atom or a perfluoromethyl group.
When the number of XA is 2 or more, the R _{LA1 having} XA may be the same or different.
When the number of XA is 2 or more, the R _{LA2 having} XA may be the same or different.
-(C (R _LA1 ) (R _LA2 ))-is preferably -CH _2- , -CHF-, -CH (CF ₃ )-, or -CF _2- .
Among them,-(C (R _LA1 ) (R _LA2 )) ^- which directly binds to A-in the general formula (PB) is -CH _2- , -CHF-, -CH (CF ₃ )-, or-. CF ₂ -is preferable.
Formula (PB) in A ^- and a direct bond to _{_{- (C (R LA1) (}} R LA2)) - other than the _{_{- (C (R LA1) (}} R LA2)) - are each independently, -CH ₂ -, -CHF-, or -CF _2- is preferable.

In the general formula (L), LB represents a single bond, an ester group (-COO-), or a sulfonyl group (-SO _2- ).

In the general formula (L), LC represents a single bond, an alkylene group, a cycloalkylene group, or a group formed by combining these ("-alkylene group-cycloalkylene group-" or the like).
The alkylene group may be linear or branched.
The alkylene group preferably has 1 to 5 carbon atoms, more preferably 1 to 2 carbon atoms, and even more preferably 1.
The cycloalkylene group preferably has 3 to 15 carbon atoms, and more preferably 5 to 10 carbon atoms.
The cycloalkylene group may be monocyclic or polycyclic.
Examples of the cycloalkylene group include a norbornanediyl group and an adamantandiyl group.
The substituent that the cycloalkylene group may have is preferably an alkyl group (either linear or branched chain, preferably 1 to 5 carbon atoms).
One or more of the methylene groups constituting the cycloalkane ring of the cycloalkylene group may be replaced with a carbonyl carbon and / or a hetero atom (oxygen atom or the like).
When the LC is "-alkylene group-cycloalkylene group-", the alkylene group portion is preferably present on the LB side.
When the LB is a single bond, the LC is preferably a single bond or a cycloalkylene group.

In the general formula (L), LD represents a single bond, an ether group (-O-), a carbonyl group (-CO-), or an ester group (-COO-).

In the general formula (L), LE is a single bond or _{_{- (C (R LE1) (}} R LE2)) XE - represents a.
_XE in the above-(C (R _LE1 ) (R _LE2 )) _XE- represents an integer of 1 or more, preferably 1 to 10, and more preferably 1 to 3.
R _LE1 and R _LE2 each independently represent a hydrogen atom or a substituent.
When the number of XEs is 2 or more, the R _LE1s having _XEs may be the same or different.
When the number of XEs is 2 or more, the R _LE2s having _XEs may be the same or different.
Among them, -(C (R _LE1 ) (R _LE2 ))-is preferably -CH _2- .
In the general formula (L), when LB, LC, and LD are single bonds, it is preferable that LE is also a single bond.

In the general formula (PB), A ⁻ represents an acid anion group.
An acid anion group is a group having an anion atom.
Specifically, A- is preferably a group represented by any of the general formulas (A-1) to (A-2).

In the general formulas (A-1) to (A-2), * represents a bonding position.
In the general formula (A-2), ^RA represents an organic group.
The ^RA is preferably an alkyl group.
The alkyl group may be linear or branched.
The alkyl group preferably has 1 to 10 carbon atoms, and more preferably 1 to 5 carbon atoms.
The substituent that the alkyl group may have is preferably a fluorine atom.
The alkyl group having a fluorine atom as a substituent may or may not be a perfluoroalkyl group.

In the general formula (PB), B ⁻ represents a group represented by any of the general formulas (B-1) to (B-4).
B ⁻ is preferably a group represented by any of the general formulas (B-1) to (B-3), and a group represented by any of the general formulas (B-1) to (B-2) is preferable. More preferred.

In the general formulas (B-1) to (B-4), * represents a bonding position.
In the general formula (B-1) ~ (B -4), R B represents an organic group.
R ^B is a cycloalkyl group or an alkyl group.
If R ^B is a cycloalkyl group, the carbon number of the cycloalkyl group is preferably 3 to 15, and more preferably 5-10.
The cycloalkyl group may be monocyclic or polycyclic.
Examples of the cycloalkyl group include a norbornyl group and an adamantyl group.
The substituent that the cycloalkyl group may have is preferably an alkyl group (which may be linear or branched, preferably having 1 to 5 carbon atoms).
One or more of the carbon atoms which are ring member atoms of the cycloalkyl group may be replaced with carbonyl carbon atoms.
If R ^B is an alkyl group, the alkyl group may be either linear or branched.
The alkyl group preferably has 1 to 10 carbon atoms, and more preferably 1 to 5 carbon atoms.
The substituent that the alkyl group may have is preferably a cycloalkyl group, a fluorine atom, or a cyano group.
Examples of the cycloalkyl group as the substituent, R ^B is a cycloalkyl group as described in the case a cycloalkyl group as well.
When the alkyl group has a fluorine atom as the substituent, the alkyl group may or may not be a perfluoroalkyl group. When the alkyl group has a fluorine atom as the substituent, it is also preferable that a part or all of the alkyl group is a perfluoromethyl group.

In the compound represented by HA-L-BH in which M ₁ ⁺ and M ₂ ^{+ of the} compound represented by the general formula (PB) are respectively substituted with hydrogen atoms, the pKa of the group represented by HA is BH. It is lower than the pKa of the represented group.
More specifically, HA-L-BH when obtained an acid dissociation constant for the compound represented by the "HA-L-BH" is - a pKa at which the ^"A -L-BH""HA and in the pKa of a group represented by "further" ^a - a pKa of the group represented by "BH a pKa at which the '" ^- -L-BH "is" ^a - -L-B.
"PKa of the group represented by HA" and "pKa of the group represented by BH" are obtained by using "Software Package 1" or "Gaussian 16", respectively.
Among them, the pKa of the group represented by HA is preferably -12.00 to 1.00, more preferably -7.00 to 0.50, and even more preferably -5.00 to 0.00.
The pKa of the group represented by HB is preferably -4.00 to 14.00, more preferably -2.00 to 12.00, and even more preferably -1.00 to 5.00.
The difference between the pKa of the group represented by HB and the pKa of the group represented by HA (“pKa of the group represented by HB”-“pKa of the group represented by HA”) is 0.10 to 20. It is preferably .00, more preferably 0.50 to 17.00, and even more preferably 2.00 to 15.00.

(Other photoacid generators)
As the resist composition, other photoacid generators other than those described above may be used.
Other photoacid generators, for example, "M ^{⁺ Z} - ^(M ⁺ represents a cation and Z ^- represents an anion)" include compounds represented by (onium salt).

^"M + Z ^-" in a compound represented by, ^{M +} represents a cation, include the same cations as the cation in formula (PA-1).
In the compounds represented by, Z ^- "M ⁺ Z" ^- represents an anion, the ability of causing a nucleophilic reaction is extremely low anion preferred.
Examples of the anion include sulfonic acid anion (aliphatic sulfonic acid anion such as fluoroalkyl sulfonic acid anion, aromatic sulfonic acid anion, camphor sulfonic acid anion, etc.) and carboxylic acid anion (aliphatic carboxylic acid anion, aromatic). Group carboxylic acid anions, aralkyl carboxylic acid anions, etc.), and tris (alkylsulfonyl) methide anions.

The aliphatic moiety in the aliphatic sulfonic acid anion and the aliphatic carboxylic acid anion may be an alkyl group or a cycloalkyl group, and may be a linear or branched alkyl group having 1 to 30 carbon atoms. , A cycloalkyl group having 3 to 30 carbon atoms is preferable.

The aromatic ring group in the aromatic sulfonic acid anion and the aromatic carboxylic acid anion is preferably an aryl group having 6 to 14 carbon atoms, and examples thereof include a phenyl group, a tolyl group, and a naphthyl group.

Examples of the substituents that the alkyl group, cycloalkyl group, and aryl group mentioned above can have include halogen atoms such as nitro group and fluorine atom, carboxylic acid group, hydroxyl group, amino group, cyano group, and alkoxy group. (Preferably 1 to 15 carbon atoms), cycloalkyl group (preferably 3 to 15 carbon atoms), aryl group (preferably 6 to 14 carbon atoms), alkoxycarbonyl group (preferably 2 to 7 carbon atoms), 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), alkyl Iminosulfonyl group (preferably 1 to 15 carbon atoms), aryloxysulfonyl group (preferably 6 to 20 carbon atoms), alkylaryloxysulfonyl group (preferably 7 to 20 carbon atoms), cycloalkylaryloxysulfonyl group (preferably 7 to 20 carbon atoms) 10 to 20 carbon atoms), an alkyloxyalkyloxy group (preferably 5 to 20 carbon atoms), and a cycloalkylalkyloxyalkyloxy group (preferably 8 to 20 carbon atoms).

The aralkyl group in the aralkyl carboxylic acid anion is preferably an aralkyl group having 7 to 12 carbon atoms, and examples thereof include a benzyl group, a phenethyl group, a naphthylmethyl group, a naphthylethyl group, and a naphthylbutyl group.

The alkyl group in the tris (alkylsulfonyl) methideanion is preferably an alkyl group having 1 to 5 carbon atoms. Examples of the substituent of these alkyl groups include a halogen atom, an alkyl group substituted with a halogen atom, an alkoxy group, an alkylthio group, an alkyloxysulfonyl group, an aryloxysulfonyl group, and a cycloalkylaryloxysulfonyl group. The alkyl group is preferably a fluorine atom or an alkyl group substituted with a fluorine atom.

As other non-nucleophilic anions, e.g., fluorinated phosphorus (e.g., PF ₆ ^-), fluorinated boron (e.g., BF ₄ ^-), and fluorinated antimony (e.g., SbF ₆ ^-) and the like.

The non-nucleophilic anion is an aliphatic sulfonic acid anion in which at least the α position of the sulfonic acid is substituted with a fluorine atom, an aromatic sulfonic acid anion in which a fluorine atom or a group having a fluorine atom is substituted, or an alkyl group in which fluorine is used. Atomically substituted tris (alkylsulfonyl) methideanions are preferred. Among them, perfluoroaliphatic sulfonic acid anion (preferably 4 to 8 carbon atoms) or benzenesulfonic acid anion having a fluorine atom is more preferable, and nonafluorobutanesulfonic acid anion, perfluorooctanesulfonic acid anion, and pentafluorobenzenesulfone are preferable. An acid anion or a 3,5-bis (trifluoromethyl) benzenesulfonic acid anion is more preferred.

From the viewpoint of acid strength, it is preferable that the pKa of the generated acid is -1 or less in order to improve the sensitivity.

Further, as the non-nucleophilic anion, an anion represented by the following general formula (AN1) is also preferable.

During the ceremony
Xf independently represents a fluorine atom or an alkyl group substituted with at least one fluorine atom.
R ¹ and R ² independently represent a hydrogen atom, a fluorine atom, or an alkyl group, and when a plurality of them are present, R ¹ and R ² may be the same or different, respectively.
L represents a divalent linking group, and when there are a plurality of L, L may be the same or different.
A represents a cyclic organic group.
x represents an integer of 1 to 20, y represents an integer of 0 to 10, and z represents an integer of 0 to 10.

The general formula (AN1) will be described in more detail.
The number of carbon atoms of the alkyl group in the alkyl group substituted with the fluorine atom of Xf is preferably 1 to 10, and more preferably 1 to 4. The alkyl group substituted with the fluorine atom of Xf is preferably a perfluoroalkyl group.
Xf is preferably a fluorine atom or a perfluoroalkyl group having 1 to 4 carbon atoms. Xf is, for example, fluorine atom, CF ₃ , C ₂ F ₅ , C ₃ F ₇ , C ₄ F ₉ , 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 , among others, fluorine atom or CF. ₃ is preferable. In particular, it is preferable that both Xfs are fluorine atoms.

The alkyl groups of R ¹ and R ² may have a substituent (preferably a fluorine atom), and the number of carbon atoms in the substituent is preferably 1 to 4. The substituent is preferably a perfluoroalkyl group having 1 to 4 carbon atoms. Alkyl groups having substituents for R ¹ and R ² include, 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 and the} like can be mentioned, and among them, CF ₃ is preferable.
R ¹ and R ² are preferably a fluorine atom or CF ₃ .

x is preferably an integer of 1 to 10, and more preferably 1 to 5.
y is preferably an integer of 0 to 4, more preferably 0.
z is preferably an integer of 0 to 5, and more preferably an integer of 0 to 3.
Examples of the divalent linking group of L include -COO-, -CO-, -O-, -S-, -SO-, -SO _2- , alkylene group, cycloalkylene group, alkenylene group, and these. Examples thereof include a linking group in which a plurality of the groups are linked, and a linking group having a total carbon number of 12 or less is preferable. Among them, -COO-, -CO-, or -O- is preferable, and -COO- is more preferable.

The cyclic organic group of A is not particularly limited as long as it has a cyclic structure, and has an alicyclic group, an aromatic ring group, and a heterocyclic group (not only those having aromaticity but also aromaticity). (Including those that do not), etc.
The alicyclic group may be monocyclic or polycyclic, and a monocyclic cycloalkyl group such as a cyclopentyl group, a cyclohexyl group, and a cyclooctyl group is preferable, and in addition, a norbornyl group, a tricyclodecanyl group, and a tetracyclo Polycyclic cycloalkyl groups such as a decanyl group, a tetracyclododecanyl group, and an adamantyl group are preferable. Among them, alicyclic groups 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, are used in the post-exposure heating step. It is preferable from the viewpoint of suppressing the diffusivity in the membrane and improving the MEEF (Mask Error Enhancement Factor).
Examples of the aromatic ring group include a benzene ring, a naphthalene ring, a phenanthrene ring, an anthracene ring and the like.
Examples of the heterocyclic group include groups derived from a furan ring, a thiophene ring, a benzofuran ring, a benzothiophene ring, a dibenzofuran ring, a dibenzothiophene ring, a pyridine ring and the like. Of these, a group derived from a furan ring, a thiophene ring, or a pyridine ring is preferable.

Further, examples of the cyclic organic group include a lactone structure, and specific examples thereof include lactone structures represented by the above-mentioned general formulas (LC1-1) to (LC1-22).

The cyclic organic group may have a substituent. The substituent may be an alkyl group (linear or branched chain, may contain a cyclic structure, preferably 1 to 12 carbon atoms), a cycloalkyl group (monocyclic or polycyclic). It may be a spiro ring when it is a polycycle. It preferably has 3 to 20 carbon atoms, an aryl group (preferably 6 to 14 carbon atoms), a hydroxyl group, an alkoxy group, an ester group, and an amide. Examples thereof include a group, a urethane group, a ureido group, a thioether group, a sulfonamide group, and a sulfonic acid ester group. The carbon constituting the cyclic organic group (carbon that contributes to ring formation) may be carbonyl carbon.

Further, the photoacid generator may be a betaine compound having a cation portion and an anion portion and having a structure in which both are covalently linked.

Examples of the photoacid generator include paragraphs [0368] to [0377] of JP2014-413328A and paragraphs [0240] to [0262] of JP2013-228681A (corresponding US Patent Application Publication No. [0339]) of the specification of 2015/004533 can be incorporated, and these contents are incorporated in the specification of the present application.
Moreover, the following compound is mentioned as a preferable specific example. In the following compounds, anions and cations can be optionally exchanged, if possible.

The content of the photoacid generator in the resist composition is not particularly limited, but is preferably 5% by mass or more, preferably 9% by mass or more, based on the total solid content of the composition, in that the effect of the present invention is more excellent. More preferably, 15% by mass or more is further preferable. The content is preferably 40% by mass or less, more preferably 35% by mass or less, and further preferably 30% by mass or less.
The photoacid generator may be used alone or in combination of two or more.

<(C) Solvent>
The resist composition may contain a solvent.
The solvent is from (M1) propylene glycol monoalkyl ether carboxylate and (M2) propylene glycol monoalkyl ether, lactic acid ester, acetate ester, alkoxypropionic acid ester, chain ketone, cyclic ketone, lactone, and alkylene carbonate. It is preferable to include at least one selected from the group. The solvent may further contain components other than the components (M1) and (M2).

The present inventors have found that when such a solvent is used in combination with the above-mentioned resin, the coatability of the composition is improved and a pattern having a small number of development defects can be formed. The reason is not always clear, but since these solvents have a good balance of solubility, boiling point and viscosity of the above-mentioned resin, uneven film thickness of the composition film and generation of precipitates in spin coating can be suppressed. The present inventors believe that this is due to.

The component (M1) is preferably at least one selected from the group consisting of propylene glycol monomethyl ether acetate (PGMEA: propylene glycol monomethyl ether acetate), propylene glycol monomethyl ether propionate, and propylene glycol monoethyl ether acetate, preferably propylene glycol. Monomethyl ether acetate (PGMEA) is more preferred.

The following solvent is preferable as the component (M2).
As the propylene glycol monoalkyl ether, propylene glycol monomethyl ether (PGME) and propylene glycol monoethyl ether (PGEE) are preferable.
The lactate ester is preferably ethyl lactate, butyl lactate, or propyl lactate.
The acetic acid ester is preferably methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, propyl acetate, isoamyl acetate, methyl formate, ethyl acetate, butyl formate, propyl formate, or 3-methoxybutyl acetate.
Butyl butyrate is also preferred.
The alkoxypropionate ester is preferably methyl 3-methoxypropionate (MMP) or ethyl 3-ethoxypropionate (EEP).
Chain ketones are 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 2-heptanone, 4-heptanone, 1-hexanone, 2-hexanone, diisobutyl ketone, phenylacetone, methyl ethyl ketone, methyl isobutyl ketone. , Acetoneacetone, acetonylacetone, ionone, diacetonyl alcohol, acetylcarbinol, acetophenone, methylnaphthyl ketone, or methyl amyl ketone is preferred.
The cyclic ketone is preferably methylcyclohexanone, isophorone, cyclopentanone, or cyclohexanone.
The lactone is preferably γ-butyrolactone.
The alkylene carbonate is preferably propylene carbonate.

The component (M2) is more preferably propylene glycol monomethyl ether (PGME), ethyl lactate, ethyl 3-ethoxypropionate, methylamyl ketone, cyclohexanone, butyl acetate, pentyl acetate, γ-butyrolactone, or propylene carbonate.

In addition to the above components, it is preferable to use an ester solvent having 7 or more carbon atoms (preferably 7 to 14, more preferably 7 to 12 and even more preferably 7 to 10) and having a heteroatom number of 2 or less.

Examples of the ester solvent having 7 or more carbon atoms and 2 or less heteroatomic atoms include amyl acetate, 2-methylbutyl acetate, 1-methylbutyl acetate, hexyl acetate, pentyl propionate, hexyl propionate, butyl propionate, and iso. Examples thereof include isobutyl butyrate, heptyl propionate, butyl butanoate and the like, and isoamyl acetate is preferable.

The component (M2) is preferably a solvent having a flash point (hereinafter, also referred to as fp) of 37 ° C. or higher.
Such components (M2) include propylene glycol monomethyl ether (fp: 47 ° C.), ethyl lactate (fp: 53 ° C.), ethyl 3-ethoxypropionate (fp: 49 ° C.), and methylamyl ketone (fp: 42 ° C.). ), Cyclohexanone (fp: 44 ° C), pentyl acetate (fp: 45 ° C), methyl 2-hydroxyisobutyrate (fp: 45 ° C), γ-butyrolactone (fp: 101 ° C), or propylene carbonate (fp: 132 ° C). ℃) is preferable. Of these, propylene glycol monoethyl ether, ethyl lactate, pentyl acetate, or cyclohexanone is more preferable, and propylene glycol monoethyl ether or ethyl lactate is even more preferable.
Here, the "flash point" means a value described in the reagent catalog of Tokyo Chemical Industry Co., Ltd. or Sigma-Aldrich Co., Ltd.

The solvent preferably contains the component (M1). It is more preferable that the solvent is substantially composed of only the component (M1), or is a mixed solvent of the component (M1) and other components. In the latter case, the solvent more preferably contains both the component (M1) and the component (M2).

The mass ratio (M1 / M2) of the component (M1) to the component (M2) is preferably "100/0" to "0/10", more preferably "100/0" to "15/85", and " "100/0" to "40/60" are more preferable, and "100/0" to "60/40" are particularly preferable. That is, when the solvent contains both the component (M1) and the component (M2), the mass ratio of the component (M1) to the component (M2) is preferably 15/85 or more, more preferably 40/60 or more. 60/40 or more is more preferable. By adopting such a configuration, the number of development defects can be further reduced.

When the solvent contains both the component (M1) and the component (M2), the mass ratio of the component (M1) to the component (M2) is, for example, 99/1 or less.

As described above, the solvent may further contain components other than the components (M1) and (M2). In this case, the content of the components other than the components (M1) and (M2) is preferably 5 to 30% by mass with respect to the total amount of the solvent.

The content of the solvent in the resist composition is preferably set so that the solid content concentration is 0.5 to 30% by mass, and more preferably 1 to 20% by mass. By doing so, the coatability of the resist composition can be further improved.
The solid content means all components other than the solvent.

<(D) Acid diffusion control agent>
The resist composition may further contain an acid diffusion control agent. The acid diffusion control agent acts as a quencher for trapping the acid generated from the photoacid generator, and plays a role of controlling the acid diffusion phenomenon in the resist film.
The acid diffusion control agent may be, for example, a basic compound.
The basic compound is preferably a compound having a structure represented by the following general formulas (A) to (E).

In the general formula (A) and the general formula (E), R ²⁰⁰ , R ²⁰¹ and R ²⁰² may be the same or different, and may be the same or different, and may be a hydrogen atom, an alkyl group (preferably 1 to 20 carbon atoms), or a cycloalkyl group (preferably 1 to 20 carbon atoms). Represents an aryl group (preferably 6 to 20 carbon atoms), and R ²⁰¹ and R ²⁰² may be bonded to each other to form a ring.

Regarding the above alkyl group, the alkyl group having a substituent is preferably an aminoalkyl group having 1 to 20 carbon atoms, a hydroxyalkyl group having 1 to 20 carbon atoms, or a cyanoalkyl group having 1 to 20 carbon atoms.
R ²⁰³ , R ²⁰⁴ , R ²⁰⁵ and R ²⁰⁶ may be the same or different and represent an alkyl group having 1 to 20 carbon atoms.
It is more preferable that the alkyl groups in the general formula (A) and the general formula (E) are unsubstituted.

As basic compounds, guanidine, aminopyrrolidin, pyrazole, pyrazoline, piperazine, aminomorpholine, aminoalkylmorpholin (alkyl group portion may be linear or branched chain, partly replaced with ether group and / or ester group. The total number of all amino acids other than the hydrogen atom of the alkyl group portion is preferably 1 to 17), or piperidine or the like is preferred. Among them, a compound having an imidazole structure, a diazabicyclo structure, an onium hydroxide structure, an onium carboxylate structure, a trialkylamine structure, an aniline structure, or a pyridine structure, an alkylamine derivative having a hydroxyl group and / or an ether bond, or a hydroxyl group and / Or an aniline derivative having an ether bond or the like is more preferable.

Examples of the compound having an imidazole structure include imidazole, 2,4,5-triphenylimidazole, and benzimidazole. Compounds having a diazabicyclo structure include, for example, 1,4-diazabicyclo [2,2,2] octane, 1,5-diazabicyclo [4,3,0] nona-5-ene, and 1,8-diazabicyclo [ 5,4,0] Undeca-7-en and the like. Examples of the compound having an onium hydroxide structure include triarylsulfonium hydroxide, phenacylsulfonium hydroxide, and sulfonium hydroxide having a 2-oxoalkyl group. Specifically, triphenylsulfonium hydroxide, tris (t-butylphenyl) sulfonium hydroxide, bis (t-butylphenyl) iodonium hydroxide, phenacylthiophenium hydroxydo, and 2-oxopropylthiophenium hydroxydo. Do etc. can be mentioned. Examples of the compound having an onium carboxylate structure include those in which the anion portion of the compound having an onium hydroxide structure is carboxylated, and examples thereof include acetate, adamantane-1-carboxylate, and perfluoroalkyl carboxylate. Can be mentioned. Examples of the compound having a trialkylamine structure include tri (n-butyl) amine and tri (n-octyl) amine. Examples of the aniline compound include 2,6-diisopropylaniline, N, N-dimethylaniline, N, N-dibutylaniline, N, N-dihexylaniline and the like. Examples of the alkylamine derivative having a hydroxyl group and / or an ether bond, for example, ethanolamine, diethanolamine, triethanolamine, tris (methoxyethoxyethyl) amine, _{_{and, (HO-C 2 H 4}} -O-C2H4) 2 N ( -C ₃ H ₆ -O-CH ₃ ) and the like. Examples of the aniline derivative having a hydroxyl group and / or an ether bond include N, N-bis (hydroxyethyl) aniline and the like.

Preferred examples of the basic compound include an amine compound having a phenoxy group and an ammonium salt compound having a phenoxy group.

As the amine compound, for example, primary, secondary and tertiary amine compounds can be used, and an amine compound in which at least one alkyl group is bonded to a nitrogen atom is preferable. The amine compound is more preferably a tertiary amine compound. The amine compound has a cycloalkyl group (preferably 3 to 20 carbon atoms) or an aryl group (preferably 3 to 20 carbon atoms) in addition to the alkyl group as long as at least one alkyl group (preferably 1 to 20 carbon atoms) is bonded to the nitrogen atom. Preferably, 6 to 12) carbon atoms may be bonded to the nitrogen atom.
Further, the amine compound preferably has an oxyalkylene group. The number of oxyalkylene groups is preferably 1 or more in the molecule, more preferably 3 to 9, and even more preferably 4 to 6. Among the oxyalkylene groups, an oxyethylene group (-CH ₂ CH ₂ O-) or an oxypropylene group (-CH (CH ₃ ) CH ₂ O- or CH ₂ CH ₂ CH ₂ O-) is preferable, and an oxyethylene group. Is more preferable.

Examples of the ammonium salt compound include primary, secondary, tertiary and quaternary ammonium salt compounds, and an ammonium salt compound in which at least one alkyl group is bonded to a nitrogen atom is preferable. The ammonium salt compound has a cycloalkyl group (preferably 3 to 20 carbon atoms) or an aryl group in addition to the alkyl group as long as at least one alkyl group (preferably 1 to 20 carbon atoms) is bonded to the nitrogen atom. (Preferably 6 to 12 carbon atoms) may be bonded to the nitrogen atom.
The ammonium salt compound preferably has an oxyalkylene group. The number of oxyalkylene groups is preferably 1 or more in the molecule, more preferably 3 to 9, and even more preferably 4 to 6. Among the oxyalkylene groups, an oxyethylene group (-CH ₂ CH ₂ O-) or an oxypropylene group (-CH (CH ₃ ) CH ₂ O- or -CH ₂ CH ₂ CH ₂ O-) is preferable. Oxyethylene groups are more preferred.
Examples of the anion of the ammonium salt compound include a halogen atom, a sulfonate, a borate, and a phosphate, and among them, a halogen atom or a sulfonate is preferable. The halogen atom is preferably a chlorine atom, a bromine atom, or an iodine atom. The sulfonate is preferably an organic sulfonate having 1 to 20 carbon atoms. Examples of the organic sulfonate include an alkyl sulfonate having 1 to 20 carbon atoms and an aryl sulfonate. The alkyl group of the alkyl sulfonate may have a substituent, and examples of the substituent include a fluorine atom, a chlorine atom, a bromine atom, an alkoxy group, an acyl group, an aromatic ring group and the like. Examples of the alkyl sulphonate include methane sulphonate, ethane sulphonate, butane sulphonate, hexane sulphonate, octane sulphonate, benzyl sulphonate, trifluoromethane sulphonate, pentafluoroethane sulphonate, nonafluorobutane sulphonate and the like. Examples of the aryl group of the aryl sulfonate include a benzene ring group, a naphthalene ring group, and an anthracene ring group. The substituents that the benzene ring group, the naphthalene ring group, and the anthracene ring group can have are a linear or branched alkyl group having 1 to 6 carbon atoms or a cycloalkyl group having 3 to 6 carbon atoms. preferable. Examples of the linear or branched alkyl group and cycloalkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, i-butyl group and t-butyl group. Examples thereof include an n-hexyl group and a cyclohexyl group. Examples of other substituents include an alkoxy group having 1 to 6 carbon atoms, a halogen atom, a cyano group, a nitro group, an acyl group, an acyloxy group and the like.

The amine compound having a phenoxy group and the ammonium salt compound having a phenoxy group are those having a phenoxy group at the terminal opposite to the nitrogen atom of the alkyl group of the amine compound or the ammonium salt compound.
Examples of the substituent of the phenoxy group include an alkyl group, an alkoxy group, a halogen atom, a cyano group, a nitro group, a carboxylic acid group, a carboxylic acid ester group, a sulfonic acid ester group, an aryl group, an aralkyl group, an acyloxy group, and Examples thereof include an aryloxy group. The substituent of the substituent may be any of 2 to 6 positions. The number of substituents may be any of 1 to 5.

It is preferable to have at least one oxyalkylene group between the phenoxy group and the nitrogen atom. The number of oxyalkylene groups is preferably 1 or more in the molecule, more preferably 3 to 9, and even more preferably 4 to 6. Among the oxyalkylene groups, an oxyethylene group (-CH ₂ CH ₂ O-) or an oxypropylene group (-CH (CH ₃ ) CH ₂ O- or -CH ₂ CH ₂ CH ₂ O-) is preferable, and oxyethylene. Groups are more preferred.

For the amine compound having a phenoxy group, a primary or secondary amine having a phenoxy group and a haloalkyl ether are heated and reacted, and then a strong base (for example, sodium hydroxide, potassium hydroxide, and tetraalkylammonium hydroxide) is added to the reaction system. Etc.) is added, and the reaction product is further extracted with an organic solvent (for example, ethyl acetate, chloroform, etc.). Alternatively, it is obtained by heating and reacting a primary or secondary amine with a haloalkyl ether having a phenoxy group at the terminal, adding an aqueous solution of a strong base to the reaction system, and further extracting the reaction product with an organic solvent. ..

(A compound (PA) that has a proton-accepting functional group and decomposes by irradiation with active light or radiation to reduce or eliminate the proton-accepting property, or to generate a compound that has changed from proton-accepting property to acidic. )
The resist composition has a proton-accepting functional group as an acid diffusion control agent, and is decomposed by irradiation with active light or radiation to reduce or eliminate the proton-accepting property, or to change from the proton-accepting property to acidic. It may contain a compound that produces a modified compound (hereinafter, also referred to as compound (PA)).

The proton-accepting functional group is a group capable of electrostatically interacting with a proton or a functional group having an electron, for example, a functional group having a macrocyclic structure such as a cyclic polyether, or a functional group having a macrocyclic structure. It means a functional group having a nitrogen atom with an unshared electron pair that does not contribute to π-conjugation. The nitrogen atom having an unshared electron pair that does not contribute to π conjugation is, for example, a nitrogen atom having a partial structure shown in the following general formula.

Preferred partial structures of the proton acceptor functional group include, for example, a crown ether structure, an aza crown ether structure, a primary to tertiary amine structure, a pyridine structure, an imidazole structure, a pyrazine structure and the like.

Compound (PA) is decomposed by irradiation with active light or radiation to generate a compound whose proton acceptor property is reduced or eliminated, or whose proton acceptor property is changed to acidic. Here, the decrease or disappearance of the proton acceptor property or the change from the proton acceptor property to the acidity is a change in the proton acceptor property due to the addition of a proton to the proton acceptor property functional group. Specifically, it means that when a proton adduct is formed from a compound (PA) having a proton acceptor functional group and a proton, the equilibrium constant in its chemical equilibrium decreases.

As the compound (PA), for example, those described in paragraphs [0421] to [0428] of JP-A-2014-413328 and paragraphs [0108]-[0116] of JP-A-2014-134686 can be incorporated. , These contents are incorporated herein by reference.

A low molecular weight compound having a nitrogen atom and a group desorbed by the action of an acid can also be used as an acid diffusion control agent. The low molecular weight compound is preferably an amine derivative having a group eliminated by the action of an acid on a nitrogen atom.
The group eliminated by the action of the acid is preferably an acetal group, a carbonate group, a carbamate group, a tertiary ester group, a tertiary hydroxyl group, or a hemiaminol ether group, and a carbamate group or a hemiaminol ether group is more preferable. preferable.
The molecular weight of the low molecular weight compound is preferably 100 to 1000, more preferably 100 to 700, and even more preferably 100 to 500.
The low molecular weight compound may have a carbamate group having a protecting group on the nitrogen atom.

Specific examples of the acid diffusion control agent are shown below, but the present invention is not limited thereto.

When the resist composition contains an acid diffusion control agent, the content of the acid diffusion control agent is preferably 0.001 to 15% by mass, preferably 0.01 to 8% by mass, based on the total solid content of the resist composition. More preferred.
The acid diffusion control agent may be used alone or in combination of two or more.
When the resist composition contains a compound represented by the general formula (PB) as a photoacid generator, the compound represented by the general formula (PB) includes a structure having a function corresponding to an acid diffusion control agent. Therefore, it is also preferable that the resist composition does not substantially contain the acid diffusion control agent. Here, the fact that the acid diffusion control agent is not substantially contained means that the content of the acid diffusion control agent is 5% by mass or less with respect to the content of the compound represented by the general formula (PB). ..

The ratio of the photoacid generator and the acid diffusion control agent used in the resist composition is preferably photoacid generator / acid diffusion control agent (molar ratio) = 2.5 to 300. The molar ratio is preferably 2.5 or more from the viewpoint of sensitivity and resolution, and the molar ratio is preferably 300 or less from the viewpoint of suppressing a decrease in resolution due to the thickening of the resist pattern over time from exposure to heat treatment. The photoacid generator / acid diffusion control agent (molar ratio) is more preferably 5.0 to 200, and even more preferably 7.0 to 150.

Examples of the acid diffusion control agent include the compounds described in paragraphs [0140] to [0144] of JP2013-11833A (amine compounds, amide group-containing compounds, urea compounds, nitrogen-containing heterocyclic compounds, etc.). Can also be mentioned.

<(E) Hydrophobic resin>
In addition to the resin (A), the resist composition may contain a hydrophobic resin different from the resin (A).
Hydrophobic resins are preferably designed to be unevenly distributed on the surface of the resist membrane, but unlike surfactants, they do not necessarily have to have hydrophilic groups in the molecule and are a uniform mixture of polar and non-polar substances. It does not have to contribute to.
The effects of adding the hydrophobic resin include controlling the static and dynamic contact angles of the resist film surface with respect to water, and suppressing outgas.

Hydrophobic resin from the viewpoint of uneven distribution in the film surface layer, "fluorine atom", "silicon atom", and has any one or more "CH ₃ partial structure contained in the side chain portion of the resin" It is preferable to have two or more kinds. Further, the hydrophobic resin preferably has a hydrocarbon group having 5 or more carbon atoms. These groups may be contained in the main chain of the resin or may be substituted in the side chain.

When the hydrophobic resin contains fluorine atoms and / or silicon atoms, the fluorine atoms and / or silicon atoms in the hydrophobic resin may be contained in the main chain of the resin and may be contained in the side chains. You may.

When the hydrophobic resin contains a fluorine atom, the partial structure having a fluorine atom is preferably an alkyl group having a fluorine atom, a cycloalkyl group having a fluorine atom, or an aryl group having a fluorine atom.
The alkyl group having a fluorine atom (preferably 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. Further, it may have a substituent other than a fluorine atom.
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 a substituent other than the fluorine atom.
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 and a naphthyl group is substituted with a fluorine atom, and further have a substituent other than the fluorine atom. May be.
Examples of the repeating unit having a fluorine atom or a silicon atom include the repeating unit exemplified in paragraph [0519] of US2012 / 0251948A1.

Further, as described above, the hydrophobic resin may preferably contain a CH ₃ partial structure side chain moiety.
Here, CH ₃ partial structure contained in the side chain portion in the hydrophobic resin, an ethyl group, and is intended to include CH ₃ partial structure a propyl group has.
On the other hand, the methyl group directly bonded to the main chain of the hydrophobic resin (for example, the α-methyl group of the repeating unit having a methacrylic acid structure) contributes to the uneven distribution of the surface of the hydrophobic resin due to the influence of the main chain. small Therefore, not included in the CH ₃ partial structures in the present invention.

Regarding the hydrophobic resin, the description in paragraphs [0348] to [0415] of JP2014-010245A can be referred to, and these contents are incorporated in the present specification.

As the hydrophobic resin, the resins described in JP2011-24801A, JP2010-175859, and JP2012-032544 can also be preferably used.

When the resist composition contains a hydrophobic resin, the content of the hydrophobic resin is preferably 0.01 to 20% by mass, more preferably 0.1 to 15% by mass, based on the total solid content of the resist composition. ..

<(F) Surfactant>
The resist composition may contain a surfactant. When a surfactant is included, a pattern having better adhesion and fewer development defects can be formed.
The surfactant is preferably a fluorine-based and / or silicon-based surfactant.
Fluorine-based and / or silicon-based surfactants include, for example, the surfactants described in paragraph [0276] of US Patent Application Publication No. 2008/0248425. In addition, Ftop EF301 or EF303 (manufactured by Shin-Akita Kasei Co., Ltd.); Florard FC430, 431, and 4430 (manufactured by Sumitomo 3M Co., Ltd.); Megafuck F171, F173, F176, F189, F113, F110, F177, F120, and R08 (manufactured by DIC Co., Ltd.); Surflon S-382, SC101, 102, 103, 104, 105 or 106 (manufactured by Asahi Glass Co., Ltd.); Troysol S-366 (manufactured by Troy Chemical Co., Ltd.) ); GF-300 or GF-150 (manufactured by Toa Synthetic Chemical Co., Ltd.), Surflon S-393 (manufactured by Seimi Chemical Co., Ltd.); Ftop EF121, EF122A, EF122B, RF122C, EF125M, EF135M, EF351, EF352, EF801, EF802 or EF601 (manufactured by Gemco Co., Ltd.); PF636, PF656, PF6320, and PF6520 (manufactured by OMNOVA); KH-20 (manufactured by Asahi Kasei Co., Ltd.); FTX-204G, 208G, 218G, 230G, 204D , 208D, 212D, 218D, and 222D (manufactured by Neos Co., Ltd.) may be used. The polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) can also be used as a silicon-based surfactant.

Further, 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) in addition to the known surfactants as shown above. May be synthesized using. 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-2002-090991.
In addition, surfactants other than the fluorine-based and / or silicon-based surfactants described in paragraph [0280] of U.S. Patent Application Publication No. 2008/0248425 may be used.

As these surfactants, one type may be used alone, or two or more types may be used.

When the resist composition contains a surfactant, the content of the surfactant is preferably 0.0001 to 2% by mass, more preferably 0.0005 to 1% by mass, based on the total solid content of the composition.

<(G) Other additives>
The resist composition comprises a dissolution inhibitory compound, a dye, a plasticizer, a photosensitizer, a light absorber, and / or a compound that promotes solubility in a developing solution (for example, a phenol compound having a molecular weight of 1000 or less, or a carboxylic acid group. (Alicyclic or aliphatic compound) containing the above may be further contained.

The resist composition may further contain a dissolution inhibitory compound. Here, the "dissolution-inhibiting compound" is a compound having a molecular weight of 3000 or less, which is decomposed by the action of an acid to reduce its solubility in an organic developer.

[Pattern formation method]
The procedure of the pattern forming method using the resist composition is not particularly limited, but it is preferable to have the following steps.
Step 1: Forming a resist film on a substrate using a resist composition Step 2: Exposing the resist film (preferably with UV light) Step 3: Using a developing solution to expose the exposed resist film Steps of developing and forming a pattern The procedure of each of the above steps will be described in detail below.

<Step 1: Resist film forming step>
Step 1 is a step of forming a resist film on the substrate using the resist composition.
The definition of the resist composition is as described above.

Examples of the method of forming a resist film on a substrate using a resist composition include a method of applying a resist composition on a substrate.
It is preferable to filter the resist composition as necessary before coating. The pore size of the filter is preferably 0.1 μm or less, more preferably 0.05 μm or less, still more preferably 0.03 μm or less. The filter is preferably made of polytetrafluoroethylene, polyethylene, or nylon.

The resist composition can be applied onto a substrate (eg, silicon, silicon dioxide coating) such as that used in the manufacture of integrated circuit elements by an appropriate coating method such as a spinner or coater. The coating method is preferably spin coating using a spinner. The rotation speed at the time of spin coating using a spinner is preferably 1000 to 3000 rpm.
After applying the resist composition, the substrate may be dried to form a resist film. If necessary, various undercoat films (inorganic film, organic film, antireflection film) may be formed under the resist film.

Examples of the drying method include a method of heating and drying. The heating can be carried out by a means provided in a normal exposure machine and / or a developing machine, and may be carried out by using a hot plate or the like. The heating temperature is preferably 80 to 150 ° C, more preferably 80 to 140 ° C, and even more preferably 80 to 130 ° C. The heating time is preferably 30 to 1000 seconds, more preferably 60 to 800 seconds, still more preferably 60 to 600 seconds.

The film thickness of the resist film is not particularly limited, but 10 to 65 nm is preferable, and 15 to 50 nm is more preferable, from the viewpoint of forming a fine pattern with higher accuracy.

A top coat may be formed on the upper layer of the resist film by using the top coat composition.
It is preferable that the topcoat composition is not mixed with the resist film and can be uniformly applied to the upper layer of the resist film.
Further, it is preferable to dry the resist film before forming the top coat. Next, the topcoat composition can be applied onto the obtained resist film by the same means as in the method for forming the resist film, and further dried to form a topcoat.
The film thickness of the top coat is preferably 10 to 200 nm, more preferably 20 to 100 nm, and even more preferably 40 to 80 nm.
The top coat is not particularly limited, and a conventionally known top coat can be formed by a conventionally known method. For example, a top coat is based on the description in paragraphs [0072] to [0082] of JP-A-2014-059543. Can be formed.
For example, it is preferable to form a top coat containing a basic compound as described in JP-A-2013-61648 on the resist film. Specific examples of the basic compound that can be contained in the top coat include basic compounds that may be contained in the resist composition described later.
Further, the top coat preferably contains a compound containing at least one group or bond selected from the group consisting of an ether bond, a thioether bond, a hydroxyl group, a thiol group, a carbonyl bond, and an ester bond.

<Process 2: Exposure process>
Step 2 is a step of exposing the resist film (preferably with EUV light).
Examples of the exposure method include a method of irradiating the formed resist film with EUV light through a predetermined mask.

It is preferable to bake (heat) after exposure and before developing. Baking accelerates the reaction of the exposed area, resulting in better sensitivity and pattern shape.
The heating temperature is preferably 80 to 150 ° C, more preferably 80 to 140 ° C, and even more preferably 80 to 130 ° C.
The heating time is preferably 10 to 1000 seconds, more preferably 10 to 180 seconds, still more preferably 30 to 120 seconds.
The heating can be carried out by means provided in a normal exposure machine and / or a developing machine, and may be carried out by using a hot plate or the like.
This process is also called post-exposure baking.

<Process 3: Development process>
Step 3 is a step of developing the exposed resist film using a developing solution to form a pattern.
The developer may be an alkaline developer or a developer containing an organic solvent (hereinafter, also referred to as an organic developer).

Examples of the developing method include a method of immersing the substrate in a tank filled with a developing solution for a certain period of time (dip method), and a method of raising the developing solution on the surface of the substrate by surface tension and allowing it to stand for a certain period of time for development (paddle). Method), a method of spraying the developer on the surface of the substrate (spray method), and a method of continuing to discharge the developer while scanning the developer discharge nozzle at a constant speed on the substrate rotating at a constant speed (dynamic discharge). Law).
Further, after the step of performing the development, a step of stopping the development may be carried out while substituting with another solvent.
The development time is not particularly limited as long as the resin in the unexposed portion is sufficiently dissolved, and is preferably 10 to 300 seconds, more preferably 20 to 120 seconds.
The temperature of the developing solution is preferably 0 to 50 ° C, more preferably 15 to 35 ° C.

It is preferable to use an alkaline aqueous solution containing alkali as the alkaline developer. The type of alkaline aqueous solution is not particularly limited, and for example, a quaternary ammonium salt typified by tetramethylammonium hydroxide, an inorganic alkali, a primary amine, a secondary amine, a tertiary amine, an alcohol amine, a cyclic amine, or the like can be used. Examples include alkaline aqueous solutions containing. Above all, the alkaline developer is preferably an aqueous solution of a quaternary ammonium salt typified by tetramethylammonium hydroxide (TMAH). An appropriate amount of alcohols, surfactants and the like may be added to the alkaline developer. The alkali concentration of the alkaline developer is usually 0.1 to 20% by mass. The pH of the alkaline developer is usually 10.0 to 15.0.

The organic developer is a developer containing at least one organic solvent selected from the group consisting of a ketone solvent, an ester solvent, an alcohol solvent, an amide solvent, an ether solvent, and a hydrocarbon solvent. It is preferable to have it.

Examples of the ketone solvent include 1-octanone, 2-octanone, 1-nonanonone, 2-nonanonone, acetone, 2-heptanone (methylamylketone), 4-heptanone, 1-hexanone, 2-hexanone, and diisobutylketone. Examples thereof include cyclohexanone, methylcyclohexanone, phenylacetone, methylethylketone, methylisobutylketone, acetylacetone, acetonylacetone, ionone, diacetonyl alcohol, acetylcarbinol, acetophenone, methylnaphthylketone, isophorone, and propylene carbonate.

Examples of the ester solvent include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, pentyl acetate, isopentyl acetate, amyl acetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, and diethylene glycol monoethyl. Ether acetate, ethyl-3-ethoxypropionate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, butanoic acid Examples thereof include butyl, methyl 2-hydroxyisobutyrate, isoamyl acetate, isobutyl isobutyrate, butyl propionate and the like.

As the alcohol solvent, the amide solvent, the ether solvent, and the hydrocarbon solvent, for example, the solvents disclosed in paragraphs [0715] to [0718] of US Patent Application Publication No. 2016/0070167A1 can be used. ..

A plurality of the above solvents may be mixed, or may be mixed with a solvent other than the above or water. The water content of the developer as a whole is preferably less than 50% by mass, more preferably less than 20% by mass, further preferably less than 10% by mass, and particularly preferably substantially free of water.
The content of the organic solvent in the organic developer is preferably 50% by mass or more and 100% by mass or less, more preferably 80% by mass or more and 100% by mass or less, and 90% by mass or more and 100% by mass or less, based on the total amount of the developing solution. The following is more preferable, and 95% by mass or more and 100% by mass or less is particularly preferable.

<Other processes>
The pattern forming method preferably includes a step of washing with a rinsing solution after the step 3.

Examples of the rinsing solution used in the rinsing step after the step of developing with an alkaline developer include pure water. An appropriate amount of surfactant may be added to pure water.
An appropriate amount of surfactant may be added to the rinse solution.

The rinse solution used in the rinse step after the development step using the organic developer is not particularly limited as long as it does not dissolve the resist pattern, and a solution containing a general organic solvent can be used. As the rinsing solution, a rinsing solution containing at least one organic solvent selected from the group consisting of a hydrocarbon solvent, a ketone solvent, an ester solvent, an alcohol solvent, an amide solvent, and an ether solvent is used. Is preferable.
Examples of the hydrocarbon solvent, the ketone solvent, the ester solvent, the alcohol solvent, the amide solvent, and the ether solvent include those similar to those described in the developing solution containing an organic solvent.

The method of the rinsing process is not particularly limited, and for example, a method of continuously discharging the rinsing liquid onto the substrate rotating at a constant speed (rotary coating method), or immersing the substrate in a tank filled with the rinsing liquid for a certain period of time. Examples thereof include a method (dip method) and a method of spraying a rinse liquid on the substrate surface (spray method).
In addition, the pattern forming method of the present invention may include a heating step (Post Bake) after the rinsing step. In this step, the developer and rinse liquid remaining between the patterns and inside the patterns are removed by baking. In addition, this step has the effect of smoothing the resist pattern and improving the surface roughness of the pattern. The heating step after the rinsing step is usually performed at 40 to 250 ° C. (preferably 90 to 200 ° C.) for 10 seconds to 3 minutes (preferably 30 seconds to 120 seconds).

Further, the substrate may be etched using the formed pattern as a mask. That is, the pattern formed in step 3 may be used as a mask to process the substrate (or the underlayer film and the substrate) to form the pattern on the substrate.
The processing method of the substrate (or the underlayer film and the substrate) is not particularly limited, but the substrate (or the underlayer film and the substrate) is dry-etched using the pattern formed in step 3 as a mask to obtain the substrate. The method of forming the pattern is preferable.
The dry etching may be one-step etching or multi-step etching. When the etching is an etching consisting of a plurality of stages, the etching of each stage may be the same process or different processes.
Any known method can be used for etching, and various conditions and the like are appropriately determined according to the type and application of the substrate. For example, the Bulletin of the International Society of Optical Engineering (Proc. Of SPIE) Vol. Etching can be performed according to 6924, 692420 (2008), Japanese Patent Application Laid-Open No. 2009-267112, and the like. In addition, the method described in "Chapter 4 Etching" of "Semiconductor Process Textbook 4th Edition 2007 Published Publisher: SEMI Japan" can also be applied.
Of these, oxygen plasma etching is preferable for dry etching.

The resist composition and various materials used in the pattern forming method of the present invention (for example, solvent, developing solution, rinsing solution, antireflection film forming composition, top coat forming composition, etc.) are made of metal or the like. It is preferable that it does not contain impurities. The content of impurities contained in these materials is preferably 1 mass ppm or less, more preferably 10 mass ppb or less, further preferably 100 mass ppt or less, particularly preferably 10 mass ppt or less, and most preferably 1 mass ppt or less. Here, examples of the metal impurities include Na, K, Ca, Fe, Cu, Mg, Al, Li, Cr, Ni, Sn, Ag, As, Au, Ba, Cd, Co, Pb, Ti, V, etc. W, Zn and the like can be mentioned.

Examples of the method for removing impurities such as metals from various materials include filtration using a filter. The pore size of the filter is preferably less than 100 nm, more preferably 10 nm or less, and even more preferably 5 nm or less. The filter is preferably made of polytetrafluoroethylene, polyethylene, or nylon. The filter may be composed of a composite material in which the above filter material and an ion exchange medium are combined. As the filter, a filter that has been previously washed with an organic solvent may be used. In the filter filtration step, a plurality of types of filters may be connected in series or in parallel. When a plurality of types of filters are used, filters having different pore diameters and / or materials may be used in combination. Further, various materials may be filtered a plurality of times, and the step of filtering the various materials a plurality of times may be a circulation filtration step.
In the production of the resist composition, for example, it is preferable to dissolve each component such as a resin and a photoacid generator in a solvent, and then perform circulation filtration using a plurality of filters made of different materials. For example, it is preferable to connect a polyethylene filter having a pore diameter of 50 nm, a nylon filter having a pore diameter of 10 nm, and a polyethylene filter having a pore diameter of 3 nm in a permutation, and perform circulation filtration 10 times or more. The smaller the pressure difference between the filters, the more preferable it is. Generally, it is 0.1 MPa or less, preferably 0.05 MPa or less, and more preferably 0.01 MPa or less. The smaller the pressure difference between the filter and the filling nozzle, the more preferable, and generally 0.5 MPa or less, 0.2 MPa or less is preferable, and 0.1 MPa or less is more preferable.
It is preferable to replace the inside of the resist composition manufacturing apparatus with an inert gas such as nitrogen. This makes it possible to suppress the dissolution of an active gas such as oxygen in the resist composition.
The resist composition is filtered through a filter and then filled in a clean container. The resist composition filled in the container is preferably stored in a refrigerator. As a result, performance deterioration over time is suppressed. The shorter the time from the completion of filling the composition into the container to the start of refrigerated storage is preferably, generally within 24 hours, preferably within 16 hours, more preferably within 12 hours, and 10 Within hours is even more preferred. The storage temperature is preferably 0 to 15 ° C, more preferably 0 to 10 ° C, and even more preferably 0 to 5 ° C.

Further, as a method of reducing impurities such as metals contained in various materials, for example, a method of selecting a raw material having a low metal content as a raw material constituting various materials, and a filter filtration of the raw materials constituting various materials are performed. Examples thereof include a method of performing distillation under conditions in which contamination is suppressed as much as possible by lining the inside of the apparatus with Teflon (registered trademark).

In addition to filter filtration, impurities may be removed by an adsorbent, or filter filtration and an adsorbent may be used in combination. As the adsorbent, a known adsorbent can be used, and for example, an inorganic adsorbent such as silica gel and zeolite, and an organic adsorbent such as activated carbon can be used. In order to reduce impurities such as metals contained in the various materials, it is necessary to prevent the mixing of metal impurities in the manufacturing process. Whether or not the metal impurities are sufficiently removed from the manufacturing apparatus can be confirmed by measuring the content of the metal component contained in the cleaning liquid used for cleaning the manufacturing apparatus. The content of the metal component contained in the cleaning liquid after use is preferably 100 mass ppt (parts per trillion) or less, more preferably 10 mass ppt or less, and further preferably 1 mass ppt or less.

Conductive compounds are added to organic treatment liquids such as rinse liquids to prevent damage to chemical liquid piping and various parts (filters, O-rings, tubes, etc.) due to static electricity charging and subsequent electrostatic discharge. You may. The conductive compound is not particularly limited, and examples thereof include methanol. The amount to be added is not particularly limited, but is preferably 10% by mass or less, more preferably 5% by mass or less, in terms of maintaining preferable development characteristics or rinsing characteristics.
As the chemical solution piping, for example, various piping coated with SUS (stainless steel), antistatic treated polyethylene, polypropylene, or fluororesin (polytetrafluoroethylene, perfluoroalkoxy resin, etc.). Can be used. Similarly, for the filter and the O-ring, antistatic treated polyethylene, polypropylene, or fluororesin (polytetrafluoroethylene, perfluoroalkoxy resin, etc.) can be used.

A method for improving the surface roughness of the pattern may be applied to the pattern formed by the method of the present invention. Examples of the method for improving the surface roughness of the pattern include a method of treating the pattern with a plasma of a hydrogen-containing gas disclosed in International Publication No. 2014/002808. In addition, JP-A-2004-235468, US Patent Application Publication No. 2010/0020297, JP-A-2008-83384, and Proc. Of SPIE Vol. 8328 83280N-1 "EUV Resist Curing Technology for LWR Reduction and Etch Sensitivity Enhancement" can be mentioned.

When the pattern to be formed is line-shaped, the aspect ratio obtained by dividing the pattern height by the line width is preferably 2.5 or less, more preferably 2.1 or less, still more preferably 1.7 or less. ..
When the pattern to be formed is a trench pattern or a contact hole pattern, the aspect ratio obtained by dividing the pattern height by the trench width or the hole diameter is preferably 4.0 or less, preferably 3.5. The following is more preferable, and 3.0 or less is further preferable.

The pattern forming method of the present invention can also be used for guide pattern forming in DSA (Directed Self-Assembly) (see, for example, ACS Nano Vol. 4 No. 8 Page 4815-4823).

Further, the pattern formed by the above method can be used as, for example, the core material (core) of the spacer process disclosed in JP-A-3-270227 and JP2013-164509.

The present invention also relates to a method for manufacturing an electronic device including the above-mentioned pattern forming method, and an electronic device manufactured by this manufacturing method.
The electronic device of the present invention is suitably mounted on an electrical and electronic device (home appliance, OA (Office Automation), media-related device, optical device, communication device, etc.).

The present invention will be described in more detail below based on examples. The materials, amounts used, proportions, treatment contents, treatment procedures, etc. shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the invention should not be construed as limiting by the examples shown below.

[Components of resist composition (actinic cheilitis or radiation-sensitive resin composition)]
〔resin〕
The repeating units of each of the resins (A-1 to A-26, A'-1 to A'-6) used in the production of the resist composition are shown below.
The resins A-1 to A-26, A'-1 to A'-2, and A'-4 to A'-6 are acid-degradable resins, and the resin A'-3 is an acid-decomposable resin. It is a resin other than.

The table below shows the content, weight average molecular weight (Mw), and dispersity (Mw / Mn) occupied by each repeating unit in each resin.
The repeating molar ratios in the table are the contents (molar ratios) occupied by each repeating unit constituting each resin shown in the upper row in order from the left.
The content occupied by each repeating unit was measured by ¹³ C-NMR (nuclear magnetic resonance).
The weight average molecular weight and the degree of dispersion are values based on the polystyrene-equivalent amount measured by GPC (carrier: tetrahydrofuran (THF)).

<Synthesis Example 1: Synthesis of Resin A-1>
Cyclohexanone (226 g) was heated to 80 ° C. under a nitrogen stream. Monomer represented by the following formula M-1 (21.5 g), monomer represented by the following formula M-2 (21.6 g), monomer represented by the following formula M-3 (58.3 g), cyclohexanone ( A mixed solution of 420 g) and dimethyl 2,2'-azobisisobutyrate (V-601, manufactured by Wako Pure Chemical Industries, Ltd.) (12.42 g) was added dropwise to the cyclohexanone over 6 hours with stirring. A reaction solution was obtained. After completion of the dropping, the reaction solution was stirred at 80 ° C. for another 2 hours. The obtained reaction solution was allowed to cool, reprecipitated with a large amount of methanol / water (mass ratio 9: 1), filtered, and the obtained solid was vacuum dried to obtain resin A-1 (89 g). It was.

The weight average molecular weight (Mw: polystyrene equivalent) determined from the GPC (carrier: tetrahydrofuran (THF)) of the obtained resin A-1 was 6500, and the dispersity (Mw / Mn) was 1.52. ^{13 The} composition ratio measured by C-NMR (nuclear magnetic resonance) was a unit based on M-1 / a unit based on M-2 / a unit based on M-3 = 20/30/50 (molar ratio).

Other resins were also synthesized in the same manner.

[Photoacid generator]
The following photoacid generators were used.
The photoacid generators B-1 to B-3 are compounds represented by the general formula (PB), and the photoacid generators C-1 to C-12 are compounds other than the compounds represented by the general formula (PB). It is a photoacid generator.
The photoacid generators C-9 to C-12 are compounds represented by the general formula (PA-1).

[Acid diffusion control agent]
The acid diffusion control agents shown below were used.

[Surfactant]
The surfactants shown below were used.
H-1: Megafuck F176 (manufactured by DIC Corporation, fluorine-based surfactant)
H-2: Megafuck R08 (manufactured by DIC Corporation, fluorine and silicon-based surfactant)
H-3: PF656 (manufactured by OMNOVA, fluorine-based surfactant)

〔solvent〕
The following solvents were used.
F-1: Propylene glycol monomethyl ether acetate (PGMEA)
F-2: Propylene glycol monomethyl ether (PGME)
F-3: Propylene glycol monoethyl ether (PGEE)
F-4: Cyclohexanone F-5: Cyclopentanone F-6: 2-Heptanone F-7: Ethyl lactate F-8: γ-Butyrolactone F-9: Propylene carbonate

[Preparation of resist composition]
Each component shown in Table 2 was mixed so that the solid content concentration was 2.0% by mass. Next, the obtained mixed solution is first passed through a polyethylene filter having a pore diameter of 50 nm, then a nylon filter having a pore diameter of 10 nm, and finally a polyethylene filter having a pore diameter of 5 nm, and filtered to form a resist composition ( Re-1 to Re-50 and Re'-1 to Re'-6) were prepared.
The solid content means all components other than the solvent. The obtained resist composition was used in Examples and Comparative Examples.
Further, in the "Amount" column in the table, the content (mass%) of each component with respect to the total solid content in the resist composition is shown.

[Pattern formation]
[EUV exposure, organic solvent development]
The underlayer film forming composition AL412 (manufactured by Brewer Science) was applied onto a silicon wafer having a diameter of 12 inches and baked at 205 ° C. for 60 seconds to form a base film having a film thickness of 20 nm. The resist composition shown in Table 3 was applied onto the resist composition and baked at 100 ° C. for 60 seconds to form a resist film having a film thickness of 30 nm.
A pattern obtained for a silicon wafer having a obtained resist film using an EUV exposure apparatus (Micro Exposure Tool, NA0.3, Quadrupole, outer sigma 0.68, inner sigma 0.36, manufactured by Exitech). Pattern irradiation was performed so that the average line width of the above was 20 nm. As the reticle, a mask having a line size of 20 nm and a line: space = 1: 1 was used.
The resist film after exposure was baked at 90 ° C. for 60 seconds, developed with n-butyl acetate for 30 seconds, and spin-dried to obtain a negative pattern.

[Evaluation]
<Defect evaluation (defect suppression)>
The pattern obtained by the above method was evaluated using UV Vision 5 (manufactured by AMAT) and SEMVision G4 (manufactured by AMAT) by counting the number of defects per silicon wafer and according to the following evaluation criteria. The smaller the number of defects, the better the defect suppression property.
In the evaluation of defect inhibitory property, a pattern was formed using the resist composition immediately after preparation and used for the evaluation.
"A": Number of defects is 50 or less "B": Number of defects is more than 50 and 100 or less "C": Number of defects is more than 100 and 200 or less "D": Number of defects is more than 200 and 300 or less ""E": Number of defects is more than 300 and 400 or less "F": Number of defects is more than 400 and less than 500 "G": Number of defects is more than 500

<Line with slagness after aging (LWR performance after aging, nm)>
The pattern obtained by the above method was observed from above the pattern using a length-measuring scanning electron microscope (SEM (Hitachi, Ltd. S-9380II)). The line width of the pattern was observed at 100 points, and the measurement variation was evaluated by 3σ and used as LWR (nm). The smaller the LWR value, the better the LWR performance after aging.
In the evaluation of the LWR performance after aging, a pattern was formed using the resist composition after preparation and then stored in a dark room at room temperature (25 ° C.) for 180 days for evaluation.
The LWR (nm) after aging is preferably 4.7 nm or less, 4.4 nm or less, 4.1 nm or less, 3.8 nm or less, 3.5 nm or 3.2 nm or less in this order.

The characteristics of the resist composition used and the evaluation results are shown in Table 3 below.
The "content" column in the table indicates whether or not the content of the photoacid generator with respect to the total solid content in the resist composition of the example is 15% by mass. If this requirement is satisfied, it is described as "A", and if it is not satisfied, it is described as "B".
The "Formula PA1" column indicates whether or not the resist composition of the example contains a compound represented by the general formula (PA-1) as a photoacid generator. If this requirement is satisfied, it is described as "A", and if it is not satisfied, it is described as "B".
The "Formula PB" column indicates whether or not the resist composition of the example contains a compound represented by the general formula (PB) as a photoacid generator. If this requirement is satisfied, it is described as "A", and if it is not satisfied, it is described as "B".
In the "a2", "a3", "a4", "a5", "a6", "b5", and "b6" columns, the resin (acid-degradable resin) contained in the resist composition of the examples is the repeating unit a2 and the repeating unit, respectively. It indicates whether or not it has a3, a repeating unit a4, a repeating unit a5, a repeating unit a6, a repeating unit b5, and a repeating unit b6. If this requirement is satisfied, it is described as "A", and if it is not satisfied, it is described as "B".

As shown in the above table, it was confirmed that the resist composition of the present invention is excellent in defect suppression property and LWR performance after aging when a pattern is formed by organic solvent development.
On the other hand, in the resist composition of the comparative example, at least one of the defect suppressing property and the LWR performance after aging was insufficient.
In the resist composition of Comparative Example 1-1, in the acid-degradable resin, only the repeating unit having no F atom at the α-position is used without using the repeating unit having the F atom at the α-position (repeating unit a1). It is considered that it is used and the shot noise of EUV light is large.
In the resist composition of Comparative Example 1-2, the acid-degradable resin uses a resin having ₃ CF groups at the α-position without using a repeating unit having an F atom at the α-position, and is developed by an organic solvent. This is probably because the solubility in the solution was too high.
In the resist composition of Comparative Example 1-3, only the non-acid-degradable resin was used without using the acid-degradable resin, and the pattern could not be formed under this condition.
In the resist composition of Comparative Example 1-4, the acid-decomposable resin uses a resin having an I atom at the α-position instead of using a repeating unit having an F atom at the α-position, and is stable over time. It is considered that the LWR performance became insufficient after a lapse of time.
In the resist composition of Comparative Example 1-5, in the acid-degradable resin, only the resin having no F atom at the α-position is used without using the repeating unit having the F atom at the α-position, and EUV is used. This is probably because the shot noise of light is large.
In the resist composition of Comparative Example 1-6, in the acid-degradable resin, only the resin having no F atom at the α-position is used without using the repeating unit having the F atom at the α-position, and EUV is used. This is probably because the shot noise of light is large.

Further, from the viewpoint that the effect of the present invention is more excellent, the resin contained in the resist composition preferably has the repeating unit a2, more preferably the repeating unit a3, and further preferably the repeating unit a4. It was confirmed that it is particularly preferable to have the repeating unit a5 or b5, and it is most preferable to have the repeating unit a6 or b6 (see the results of Examples 1-1 to 1-26, etc.).

It was confirmed that the resist composition preferably contains a compound represented by the general formula (PA-1) from the viewpoint of more excellent effect of the present invention (comparison between Examples 1-1 and 1-27). , Comparison of Examples 1-5 and 1-28, Comparison of Examples 1-9 and 1-29, Comparison of Examples 1-11 and 1-30, Examples 1-19 and 1-31 Comparison, etc.).

From the viewpoint that the effect of the present invention is more excellent, it was confirmed that the resist composition preferably contains a compound represented by the general formula (PB) (comparison and implementation of Examples 1-1 and 1-33). Comparison of Examples 1-5 and 1-34, Comparison of Examples 1-9 and 1-35, Comparison of Examples 1-11 and 1-36, Examples 1-19, 1-37 and 1- Comparison with 50, Comparison with Examples 1-20, 1-38 and 1-48, Comparison with Examples 1-21, 1-39 and 1-47, Examples 1-22, 1-40 and 1 See comparison between -41 and 1-49, etc.).

From the viewpoint of more excellent effect of the present invention, it was confirmed that the resist composition preferably contains a photoacid generator in an amount of 15% by mass or more based on the total solid content (Examples 1-1 and 1-42). Comparison, comparison between Examples 1-5 and 1-43, comparison between Examples 1-9 and 1-44, comparison between Examples 1-11 and 1-45, Examples 1-19 and 1- Comparison with 46, comparison with Examples 1-39 and 1-47, comparison with Examples 1-41 and 1-49, etc.).

[EUV exposure, alkaline aqueous solution development]
The underlayer film forming composition AL412 (manufactured by Brewer Science) was applied onto a silicon wafer having a diameter of 12 inches and baked at 205 ° C. for 60 seconds to form a base film having a film thickness of 20 nm. The resist composition shown in Table 4 was applied onto the resist composition and baked at 100 ° C. for 60 seconds to form a resist film having a film thickness of 30 nm.
A pattern obtained for a silicon wafer having a obtained resist film using an EUV exposure apparatus (Micro Exposure Tool, NA0.3, Quadrupole, outer sigma 0.68, inner sigma 0.36, manufactured by Exitech). Pattern irradiation was performed so that the average line width of the above was 20 nm. As the reticle, a mask having a line size of 20 nm and a line: space = 1: 1 was used.
The resist film after exposure was baked at 90 ° C. for 60 seconds, developed with an aqueous solution of tetramethylammonium hydroxide (2.38% by mass) for 30 seconds, and then rinsed with pure water for 30 seconds. Then, this was spin-dried to obtain a positive pattern.
Using the obtained positive pattern, the defect suppression property and the LWR performance after aging were evaluated in the same manner as described above.

The evaluation results are shown in the table below.
The significance of the description in each column in Table 4 is the same as the description in the corresponding column in Table 3.

As shown in the above table, it was confirmed that the resist composition of the present invention is excellent in defect suppression property and LWR performance after aging even when a pattern is formed by alkaline development.
On the other hand, in the resist composition of the comparative example, at least one of the defect suppressing property and the LWR performance after aging was insufficient.
In the resist composition of Comparative Example 2-1 in the acid-degradable resin, only the repeating unit having no F atom at the α-position is used without using the repeating unit having the F atom at the α-position (repeating unit a1). It is considered that it is used and the shot noise of EUV light is large.
In the resist composition of Comparative Example 2-2, in the acid-degradable resin, a resin having ₃ CF groups at the α-position is used instead of using a repeating unit having an F atom at the α-position, and an alkaline developer is used. It is thought that this is because the solubility in the water was too low.
In the resist composition of Comparative Example 2-3, only the non-acid-degradable resin was used without using the acid-degradable resin, and the pattern could not be formed under this condition.
In the resist composition of Comparative Example 2-4, in the acid-degradable resin, a resin having an I atom at the α-position is used instead of using a repeating unit having an F atom at the α-position, and the stability over time is improved. It is considered that the LWR performance became insufficient after a lapse of time.
In the resist composition of Comparative Example 2-5, in the acid-degradable resin, only the resin having no F atom at the α-position is used without using the repeating unit having the F atom at the α-position, and EUV is used. This is probably because the shot noise of light is large.
In the resist composition of Comparative Example 2-6, in the acid-degradable resin, only the resin having no F atom at the α-position is used without using the repeating unit having the F atom at the α-position, and EUV is used. This is probably because the shot noise of light is large.

Also, in the comparison between the examples, the same tendency as when the pattern was formed by organic solvent development was confirmed.

Claims

Acid-degradable resin and
Compounds that generate acid by irradiation with active light or radiation,
Including
A photosensitive or radiation-sensitive resin composition in which the acid-decomposable resin has a repeating unit a1 represented by the general formula (A1).

In the general formula (A1), RQ represents a hydrogen atom or an organic group.
The actinic or radiation-sensitive resin composition according to claim 1, wherein the repeating unit a1 contains a repeating unit a2 having an acid-degradable group.
The actinic or radiation-sensitive resin composition according to claim 2, wherein the repeating unit a2 includes a repeating unit a3 represented by the general formula (A2).

In the general formula (A2), RQ1 to RQ3 each independently represent an alkyl group.
Two of RQ1 to RQ3 may be combined with each other to form a ring.
The repeating unit a1 is, R Q is,
Hydrogen atom or
A group having one or more specific groups selected from the group consisting of a lactone group, a sultone group, a carbonate group, a hydroxyl group, a sulfonamide group, an amide group, a carboxylic acid group, and a photoacid generating group. Represents no group X,
The actinic or radiation-sensitive resin composition according to any one of claims 1 to 3, which comprises the repeating unit a4.
The actinic or radiation-sensitive resin composition according to claim 4, wherein the repeating unit a4 includes the repeating unit a5 having the group X having a fluorine atom.
The actinic or radiation-sensitive resin composition according to claim 5, wherein the repeating unit a5 includes a repeating unit a6 having the group X having a hexafluoropropanol group.
The actinic or radiation-sensitive resin composition according to any one of claims 1 to 6, wherein the acid-degradable resin has a repeating unit b5 represented by the general formula (B1).

In the general formula (B1), X represents a hydrogen atom, an alkyl group, or a halogen atom other than a fluorine atom.
L B represents a single bond or -COO-.
R B1 is a lactone group, a sultone group, a carbonate group, a hydroxyl group, a sulfonamido group, an amide group, a carboxylic acid group, and one or more specific groups selected from the group consisting of photoacid generator groups, as well as a fluorine atom Represents a group Z that has a group and is not a elimination group.
The actinic light-sensitive or radiation-sensitive resin composition according to claim 7, wherein the repeating unit b5 contains the repeating unit b6 having the group Z having a hexafluoropropanol group.
The actinic cheilitis or radiation-sensitive compound according to any one of claims 1 to 8, wherein the compound that generates an acid by irradiation with active light or radiation includes a compound represented by the general formula (PA-1). Sex resin composition.

In formula (PA-1), A 1 and A 2 are each independently, -SO 2 -R P, or represents -CO-R P. R P represents an organic group.
M + represents a cation.
The actinic light-sensitive or radiation-sensitive resin according to any one of claims 1 to 9, wherein the compound that generates an acid by irradiation with active light or radiation contains a compound represented by the general formula (PB). Composition.
M 1 + A －－ LB － M 2 + (PB)
In formula (PB), M 1 + and M 2 + each independently represents an organic cation.
L represents a divalent organic group.
A − represents an acid anion group.
However, in the general formula (PB) M 1 + and M 2 + a compound represented by the HA-L-BH, which are each substituted by a hydrogen atom of the compound represented by, pKa of the group represented by the HA, It is lower than the pKa of the group represented by BH.
B − represents a group represented by any of the general formulas (B-1) to (B-4).

In the general formulas (B-1) to (B-4), * represents a bonding position.
In the general formula (B-1) ~ (B -4), R B represents an organic group.
The actinic cheilitis or sensation according to any one of claims 1 to 10, wherein the content of the compound that generates an acid by irradiation with the active light or radiation is 15% by mass or more with respect to the total solid content. Radiation resin composition.
A step of forming a resist film on a substrate by using the actinic or radiation-sensitive resin composition according to any one of claims 1 to 11.
The step of exposing the resist film and
A step of developing the exposed resist film using a developing solution to form a pattern, and
A pattern forming method having.
A method for manufacturing an electronic device, including the pattern forming method according to claim 12.