JP5285897B2 - Resist composition and resist pattern forming method - Google Patents

Description

  The present invention relates to a resist composition and a method for forming a resist pattern using the resist composition.

In lithography technology, for example, a resist film made of a resist material is formed on a substrate, and the resist film is selectively exposed to light such as light or an electron beam through a mask on which a predetermined pattern is formed. And a development process is performed to form a resist pattern having a predetermined shape on the resist film. A resist material in which the exposed portion changes to a property that dissolves in the developer is referred to as a positive type, and a resist material that changes to a property in which the exposed portion does not dissolve in the developer is referred to as a negative type.
In recent years, in the manufacture of semiconductor elements and liquid crystal display elements, pattern miniaturization has been rapidly progressing due to advances in lithography technology.
As a technique for miniaturization, the wavelength of an exposure light source is generally shortened. Specifically, conventionally, ultraviolet rays typified by g-line and i-line have been used, but at present, mass production of semiconductor elements using a KrF excimer laser or an ArF excimer laser has started. In addition, studies have been made on F ₂ excimer lasers, electron beams, EUV (extreme ultraviolet rays), X-rays, and the like having shorter wavelengths than these excimer lasers.

  Resist materials are required to have lithography characteristics such as sensitivity to these exposure light sources and resolution capable of reproducing a pattern with fine dimensions. As a resist material that satisfies such requirements, a chemically amplified resist containing a base resin whose solubility in an alkaline developer is changed by the action of an acid and an acid generator that generates an acid upon exposure is used. For example, a positive chemically amplified resist contains, as a base resin, a resin whose solubility in an alkaline developer is increased by the action of an acid and an acid generator, and from the acid generator by exposure during resist pattern formation. When the acid is generated, the exposed portion becomes alkali-soluble.

Up to now, as a base resin for chemically amplified resist, polyhydroxystyrene (PHS) having high transparency with respect to KrF excimer laser (248 nm) and a resin whose hydroxyl group is protected with an acid dissociable, dissolution inhibiting group (PHS resin) Has been used. However, since the PHS resin has an aromatic ring such as a benzene ring, the transparency to light having a wavelength shorter than 248 nm, for example, 193 nm, is not sufficient. For this reason, a chemically amplified resist having a PHS resin as a base resin component has drawbacks such as low resolution in a process using 193 nm light, for example.
Therefore, as a resist base resin currently used in ArF excimer laser lithography and the like, it has a structural unit generally derived from a (meth) acrylic acid ester in the main chain because it is excellent in transparency near 193 nm. Resin (acrylic resin) is used. In the case of the positive type, such a resin includes a structural unit derived from a (meth) acrylic acid ester containing a tertiary alkyl ester type acid dissociable, dissolution inhibiting group containing an aliphatic polycyclic group, for example, 2-alkyl. A resin having a structural unit derived from 2-adamantyl (meth) acrylate or the like is mainly used (for example, see Patent Document 1).

  The “(meth) acrylic acid ester” means one or both of an acrylic acid ester having a hydrogen atom bonded to the α-position and a methacrylic acid ester having a methyl group bonded to the α-position. “(Meth) acrylate” means one or both of an acrylate having a hydrogen atom bonded to the α-position and a methacrylate having a methyl group bonded to the α-position. “(Meth) acrylic acid” means one or both of acrylic acid having a hydrogen atom bonded to the α-position and methacrylic acid having a methyl group bonded to the α-position.

On the other hand, various acid generators used in chemically amplified resists have been proposed so far, such as onium salt acid generators such as iodonium salts and sulfonium salts, oxime sulfonate acid generators, Diazomethane acid generators, nitrobenzyl sulfonate acid generators, imino sulfonate acid generators, disulfone acid generators and the like are known. Currently, an acid generator containing a triphenylsulfonium skeleton, a dinaphthyl monophenylsulfonium skeleton, or the like is used as the acid generator (see Patent Document 2).
JP 2003-241385 A Japanese Patent Laid-Open No. 2005-37888

In recent years, as the resist pattern is further miniaturized, it is required to improve various lithography characteristics as well as high resolution. As one of them, improvement of the depth of focus (DOF) characteristic is required in order to improve a process margin and the like during pattern formation.
“DOF” refers to a range of depth of focus in which a resist pattern can be formed with a dimension within which a deviation from a target dimension is within a predetermined range when exposure is performed with the same exposure amount while shifting the focus up and down. This is a range in which a faithful resist pattern can be obtained, and a larger value is more preferable.
However, the conventional resist composition has a problem that the DOF characteristics are insufficient. And it is thought that the improvement of lithography properties such as DOF can be achieved by improving the acid generator.
This invention is made | formed in view of the said situation, Comprising: It aims at providing the resist composition excellent in lithography characteristics, such as a depth of focus (DOF), and a resist pattern formation method.

［式中、Ｒ^７”〜Ｒ^９”は、それぞれ独立に、アリール基またはアルキル基を表し；Ｒ^７”〜Ｒ^９”のうち、いずれか２つが相互に結合して式中のイオウ原子と共に環を形成してもよく（ただし、ジベンゾチオフェン骨格は除く）；Ｒ^７”〜Ｒ^９”のうち少なくとも１つは、水素原子の一部または全部が（ｂ’−１４−２）で表される基で置換された置換アリール基であり、Ｒ^５０は直鎖状もしくは分岐鎖状のアルキレン基であり、Ｒ^５１は脂肪族環式基を含むアセタール型酸解離性基又は脂肪族環式基を含む第３級アルキルエステル型酸解離性基である。］
The present inventors propose the following means in order to solve the above problems.
That is, the first aspect of the present invention is a resist composition comprising a base material component (A) whose solubility in an alkaline developer is changed by the action of an acid, and an acid generator component (B) that generates an acid upon exposure. The acid generator component (B) includes two different acid generators (B1) and (B2) having an acid dissociable group containing an aliphatic cyclic group in the cation part, The acid generator (B2) is a resist composition having a cation moiety represented by the following general formula (b′-14).

[Wherein, R ⁷ ″ to R ⁹ ″ each independently represents an aryl group or an alkyl group; any two of R ⁷ ″ to R ⁹ ″ are bonded to each other together with a sulfur atom in the formula A ring may be formed (excluding the dibenzothiophene skeleton); at least one of R ⁷ ″ to R ⁹ ″ represents a part or all of hydrogen atoms represented by (b′-14-2). R ⁵⁰ is a linear or branched alkylene group, and R ⁵¹ is an acetal-type acid dissociable group or aliphatic cyclic group containing an aliphatic cyclic group. a tertiary alkyl ester-type acid dissociable group containing a. ]

  The second aspect of the present invention includes a step of forming a resist film on a support using the resist composition of the first aspect of the present invention, a step of exposing the resist film, and the resist film. This is a resist pattern forming method including a step of forming a resist pattern by alkali development.

In the present specification and claims, the “structural unit” means a monomer unit (monomer unit) constituting a resin component (polymer).
“Exposure” is a concept that includes radiation exposure in general.
An “acid-dissociable group” is an organic group that can be dissociated by the action of an acid.
The “aliphatic cyclic group” is a monocyclic group or a polycyclic group having no aromaticity.
The “alkyl group” includes linear, branched and cyclic monovalent saturated hydrocarbon groups unless otherwise specified.
The “lower alkyl group” means an alkyl group having 1 to 5 carbon atoms.

  The present invention provides a resist composition and a resist pattern forming method that are excellent in lithography properties such as depth of focus (DOF).

≪Resist composition≫
The resist composition of the first aspect of the present invention generates a base component (A) (hereinafter referred to as component (A)) whose solubility in an alkaline developer is changed by the action of an acid, and an acid upon exposure. A resist composition containing an acid generator component (B) (hereinafter referred to as component (B)), wherein the component (B) comprises two different acids having an acid dissociable group in the cation moiety. It contains generators (B1) and (B2).

In the resist composition of the present invention, as the component (A), a polymer material whose solubility in an alkali developer is changed by the action of an acid can be used, and the solubility in an alkali developer is changed by the action of an acid. Low molecular weight materials can also be used.
The resist composition of the present invention may be a negative resist composition or a positive resist composition.
When the resist composition of the present invention is a negative resist composition, for example, the component (A) is an alkali-soluble resin, and a crosslinking agent (C) is further blended in the negative resist composition.
In such a negative resist composition, when an acid is generated from the component (B) by exposure at the time of resist pattern formation, the exposed portion acts to cause crosslinking between the alkali-soluble resin and the crosslinking agent. Change to insoluble.
As the alkali-soluble resin, a resin having a unit derived from at least one selected from α- (hydroxyalkyl) acrylic acid or a lower alkyl ester of α- (hydroxyalkyl) acrylic acid is a good resist with little swelling. A pattern can be formed, which is preferable. Α- (Hydroxyalkyl) acrylic acid includes acrylic acid in which a hydrogen atom is bonded to the α-position carbon atom to which the carboxy group is bonded, and a hydroxyalkyl group (preferably having 1 carbon atom) in the α-position carbon atom. One or both of [alpha] -hydroxyalkylacrylic acids to which (5) hydroxyalkyl groups) are attached.
As the crosslinking agent (C), for example, it is usually preferable to use an amino crosslinking agent such as glycoluril having a methylol group or an alkoxymethyl group because a good resist pattern with little swelling can be formed. It is preferable that the compounding quantity of a crosslinking agent (C) is 1-50 mass parts with respect to 100 mass parts of alkali-soluble resin.

  When the resist composition of the present invention is a positive resist composition, the solubility of the component (A) in an alkaline developer is increased by the action of an acid. That is, the component (A) is an alkali-insoluble one having a so-called acid dissociable, dissolution inhibiting group, and when acid is generated from the component (B) by exposure at the time of resist pattern formation, the acid is dissociated by an acid dissociable, dissolution inhibiting group. (A) component becomes alkali-soluble by dissociating. Therefore, in the formation of the resist pattern, when the resist film obtained by applying the positive resist composition on the support is selectively exposed, the exposed portion turns into alkali-soluble, while the unexposed portion becomes alkaline. Since it remains insoluble and does not change, alkali development can be performed.

  In the resist composition of the present invention, the component (A) is preferably a resin component (A1) (hereinafter referred to as the component (A1)) whose solubility in an alkaline developer is increased by the action of an acid. That is, the resist composition of the present invention is preferably a positive resist composition.

<(A1) component>
The component (A1) suitably used in such a positive resist composition preferably has a structural unit (a1) derived from an acrylate ester containing an acid dissociable, dissolution inhibiting group.
The component (A1) preferably further has a structural unit (a2) derived from an acrylate ester containing a lactone-containing cyclic group.
The component (A1) preferably further has a structural unit (a3) derived from an acrylate ester containing a polar group-containing aliphatic hydrocarbon group.

Here, in the present specification and claims, the “structural unit derived from an acrylate ester” means a structural unit formed by cleavage of an ethylenic double bond of an acrylate ester.
“Acrylic acid esters” include those in which a hydrogen atom is bonded to the carbon atom at the α-position, and those in which a substituent (atom or group other than a hydrogen atom) is bonded to the carbon atom in the α-position. Include concepts. Examples of the substituent include a lower alkyl group and a halogenated lower alkyl group.
Note that the α-position (α-position carbon atom) of a structural unit derived from an acrylate ester means a carbon atom to which a carbonyl group is bonded, unless otherwise specified.
In the acrylate ester, as the lower alkyl group as a substituent at the α-position, specifically, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, Examples include lower linear or branched alkyl groups such as isopentyl group and neopentyl group.
In the present invention, the α-position of the acrylate ester is preferably a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group, and is a hydrogen atom, a lower alkyl group or a fluorinated lower alkyl group. Of these, a hydrogen atom or a methyl group is particularly preferred from the viewpoint of industrial availability.

・ Structural unit (a1)
The structural unit (a1) is a structural unit derived from an acrylate ester containing an acid dissociable, dissolution inhibiting group.
The acid dissociable, dissolution inhibiting group in the structural unit (a1) has an alkali dissolution inhibiting property that makes the entire component (A1) difficult to dissolve in an alkali developer before dissociation, and dissociates with an acid. This increases the solubility of the entire component in an alkaline developer, and those that have been proposed as acid dissociable, dissolution inhibiting groups for base resins for chemically amplified resists can be used.
In general, a group that forms a cyclic or chain tertiary alkyl ester with a carboxy group in (meth) acrylic acid or the like; an acetal-type acid dissociable, dissolution inhibiting group such as an alkoxyalkyl group is widely known. . The “(meth) acrylic acid ester” means one or both of an acrylic acid ester having a hydrogen atom bonded to the α-position and a methacrylic acid ester having a methyl group bonded to the α-position.

Here, the “tertiary alkyl ester” is an ester formed by replacing a hydrogen atom of a carboxy group with a chain or cyclic alkyl group, and the carbonyloxy group (—C (O)). A structure in which the tertiary carbon atom of the chain or cyclic alkyl group is bonded to the terminal oxygen atom of -O-). In this tertiary alkyl ester, when an acid acts, a bond is cut between an oxygen atom and a tertiary carbon atom.
The chain or cyclic alkyl group may have a substituent.
Hereinafter, a group that is acid dissociable by constituting a carboxy group and a tertiary alkyl ester is referred to as a “tertiary alkyl ester type acid dissociable, dissolution inhibiting group” for convenience.
Examples of the tertiary alkyl ester type acid dissociable, dissolution inhibiting group include an aliphatic branched acid dissociable, dissolution inhibiting group and an acid dissociable, dissolution inhibiting group containing an aliphatic cyclic group.

Here, “aliphatic” in the claims and the specification is a relative concept with respect to aromatics, and is defined to mean a group, a compound, or the like that does not have aromaticity.
“Aliphatic branched” means having a branched structure having no aromaticity.
The structure of the “aliphatic branched acid dissociable, dissolution inhibiting group” is not limited to a group consisting of a carbon atom and a hydrogen atom (hydrocarbon group), but is preferably a hydrocarbon group.
The “hydrocarbon group” may be either saturated or unsaturated, but is usually preferably saturated.
As the aliphatic branched acid dissociable, dissolution inhibiting group, a tertiary alkyl group having 4 to 8 carbon atoms is preferable, and specific examples include a tert-butyl group, a tert-pentyl group, and a tert-heptyl group. .

The “aliphatic cyclic group” means a monocyclic group or a polycyclic group having no aromaticity.
The “aliphatic cyclic group” in the structural unit (a1) may or may not have a substituent. Examples of the substituent include a lower alkyl group having 1 to 5 carbon atoms, a lower alkoxy group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated lower alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, an oxygen atom (= O), and the like.
The basic ring structure excluding the substituent of the “aliphatic cyclic group” is not limited to a group consisting of carbon and hydrogen (hydrocarbon group), but is preferably a hydrocarbon group. The “hydrocarbon group” may be either saturated or unsaturated, but is usually preferably saturated. The “aliphatic cyclic group” is preferably a polycyclic group.
Examples of the aliphatic cyclic group include monocycloalkanes, bicycloalkanes, tricycloalkanes, tetracycloalkanes which may or may not be substituted with a lower alkyl group, a fluorine atom or a fluorinated alkyl group. And groups obtained by removing one or more hydrogen atoms from a polycycloalkane. More specifically, monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane are exemplified. .

  Examples of the acid dissociable, dissolution inhibiting group containing an aliphatic cyclic group include a group having a tertiary carbon atom on the ring skeleton of a cyclic alkyl group. Specifically, 2-methyl-2 -Adamantyl group, 2-ethyl-2-adamantyl group, etc. are mentioned. Alternatively, in the structural units represented by the following general formulas (a1 ″ -1) to (a1 ″ -6), an adamantyl group such as a group bonded to an oxygen atom of a carbonyloxy group (—C (O) —O—) An aliphatic cyclic group such as a cyclohexyl group, a cyclopentyl group, a norbornyl group, a tricyclodecanyl group, or a tetracyclododecanyl group, and a branched alkylene group having a tertiary carbon atom bonded thereto. Groups.

［式中、Ｒは水素原子、低級アルキル基またはハロゲン化低級アルキル基を示し、Ｒ^１５、Ｒ^１６はアルキル基（直鎖状、分岐鎖状のいずれでもよく、好ましくは炭素数１〜５である。）を示す。］

[Wherein, R represents a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group, and R ¹⁵ and R ¹⁶ may be alkyl groups (both linear and branched, preferably having 1 to 5 carbon atoms). Yes.) ]

  In the general formulas (a1 ″ -1) to (a1 ″ -6), the lower alkyl group or halogenated lower alkyl group of R is a lower alkyl group or halogenated lower alkyl which may be bonded to the α-position of the acrylate ester. It is the same as the alkyl group.

The “acetal acid dissociable, dissolution inhibiting group” is generally bonded to an oxygen atom by substituting a hydrogen atom at the terminal of an alkali-soluble group such as a carboxy group or a hydroxyl group. When an acid is generated by exposure, the acid acts to break the bond between the acetal acid dissociable, dissolution inhibiting group and the oxygen atom to which the acetal acid dissociable, dissolution inhibiting group is bonded.
Examples of the acetal type acid dissociable, dissolution inhibiting group include a group represented by the following general formula (p1).

［式中、Ｒ^１’，Ｒ^２’はそれぞれ独立して水素原子または低級アルキル基を表し、ｎは０〜３の整数を表し、Ｙは低級アルキル基または脂肪族環式基を表す。］

[Wherein, R ¹ ′ and R ² ′ each independently represents a hydrogen atom or a lower alkyl group, n represents an integer of 0 to 3, and Y represents a lower alkyl group or an aliphatic cyclic group. ]

In the above formula, n is preferably an integer of 0 to 2, more preferably 0 or 1, and most preferably 0.
Examples of the lower alkyl group for R ¹ ′ and R ² ′ include the same lower alkyl groups as those described above for R. A methyl group or an ethyl group is preferable, and a methyl group is most preferable.
In the present invention, it is preferable that at least one of R ¹ ′ and R ² ′ is a hydrogen atom. That is, the acid dissociable, dissolution inhibiting group (p1) is preferably a group represented by the following general formula (p1-1).

［式中、Ｒ^１’、ｎ、Ｙは上記と同様である。］

[Wherein R ¹ ′, n and Y are the same as described above. ]

Examples of the lower alkyl group for Y include the same lower alkyl groups as those described above for R.
The aliphatic cyclic group for Y can be appropriately selected from monocyclic or polycyclic aliphatic cyclic groups that have been proposed in a number of conventional ArF resists. For example, the above “aliphatic ring” Examples thereof are the same as those in the formula group.

  Examples of the acetal type acid dissociable, dissolution inhibiting group also include a group represented by the following general formula (p2).

［式中、Ｒ^１７、Ｒ^１８はそれぞれ独立して直鎖状または分岐鎖状のアルキル基または水素原子であり、Ｒ^１９は直鎖状、分岐鎖状または環状のアルキル基である。または、Ｒ^１７およびＲ^１９がそれぞれ独立に直鎖状または分岐鎖状のアルキレン基であって、Ｒ^１７の末端とＲ^１９の末端とが結合して環を形成していてもよい。］

[Wherein, R ¹⁷ and R ¹⁸ each independently represent a linear or branched alkyl group or a hydrogen atom, and R ¹⁹ represents a linear, branched or cyclic alkyl group. Alternatively, R ¹⁷ and R ¹⁹ may be each independently a linear or branched alkylene group, and the end of R ^{17 and} the end of R ¹⁹ may be bonded to form a ring. ]

In R ¹⁷ and R ¹⁸ , the alkyl group preferably has 1 to 15 carbon atoms, may be linear or branched, and is preferably an ethyl group or a methyl group, and most preferably a methyl group.
In particular, it is preferable that one of R ¹⁷ and R ¹⁸ is a hydrogen atom and the other is a methyl group.
R ¹⁹ is a linear, branched or cyclic alkyl group, preferably having 1 to 15 carbon atoms, and may be any of linear, branched or cyclic.
When R ¹⁹ is linear or branched, it preferably has 1 to 5 carbon atoms, more preferably an ethyl group or a methyl group, and most preferably an ethyl group.
When R ¹⁹ is cyclic, it preferably has 4 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, one or more polycycloalkanes such as monocycloalkane, bicycloalkane, tricycloalkane, and tetracycloalkane, which may or may not be substituted with a fluorine atom or a fluorinated alkyl group, are included. Examples include a group excluding a hydrogen atom. Specific examples include monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among them, a group obtained by removing one or more hydrogen atoms from adamantane is preferable.
In the above formula, R ¹⁷ and R ¹⁹ are each independently a linear or branched alkylene group (preferably an alkylene group having 1 to 5 carbon atoms), and the end of R ^{19 and} the end of R ¹⁷ And may be combined.
In this case, a cyclic group is formed by R ¹⁷ , R ¹⁹ , the oxygen atom to which R ¹⁹ is bonded, and the carbon atom to which the oxygen atom and R ¹⁷ are bonded. The cyclic group is preferably a 4- to 7-membered ring, and more preferably a 4- to 6-membered ring. Specific examples of the cyclic group include a tetrahydropyranyl group and a tetrahydrofuranyl group.

  As the structural unit (a1), one or more selected from the group consisting of structural units represented by the following general formula (a1-0-1) and structural units represented by the following general formula (a1-0-2): Is preferably used.

［式中、Ｒは水素原子、低級アルキル基またはハロゲン化低級アルキル基を示し；Ｘ^１は酸解離性溶解抑制基を示す。］

[Wherein, R represents a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group; and X ¹ represents an acid dissociable, dissolution inhibiting group. ]

［式中、Ｒは水素原子、低級アルキル基またはハロゲン化低級アルキル基を示し；Ｘ^２は酸解離性溶解抑制基を示し；Ｙ^２はアルキレン基または脂肪族環式基を示す。］

[Wherein, R represents a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group; X ² represents an acid dissociable, dissolution inhibiting group; Y ² represents an alkylene group or an aliphatic cyclic group. ]

In general formula (a1-0-1), the lower alkyl group or halogenated lower alkyl group for R is the same as the lower alkyl group or halogenated lower alkyl group that may be bonded to the α-position of the acrylate ester. .
X ¹ is not particularly limited as long as it is an acid dissociable, dissolution inhibiting group, and examples thereof include the above-described tertiary alkyl ester type acid dissociable, dissolution inhibiting group and acetal type acid dissociable, dissolution inhibiting group. A tertiary alkyl ester type acid dissociable, dissolution inhibiting group is preferred.

In general formula (a1-0-2), R is the same as defined above.
X ² is the same as X ¹ in formula (a1-0-1).
Y ² is preferably an alkylene group having 1 to 10 carbon atoms or a divalent aliphatic cyclic group, and a group in which two or more hydrogen atoms are removed is used as the aliphatic cyclic group. Except for the above, the same “aliphatic cyclic group” as described above can be used.
When Y ² is an alkylene group having 1 to 10 carbon atoms, it is more preferably 1 to 6 carbon atoms, particularly preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. .
When Y ² is a divalent aliphatic cyclic group, a group in which two or more hydrogen atoms have been removed from cyclopentane, cyclohexane, norbornane, isobornane, adamantane, tricyclodecane, or tetracyclododecane is particularly preferable. .

  More specifically, examples of the structural unit (a1) include structural units represented by the following general formulas (a1-1) to (a1-4).

［上記式中、Ｘ’は第３級アルキルエステル型酸解離性溶解抑制基を表し、Ｙは炭素数１〜５の低級アルキル基、または脂肪族環式基を表し；ｎは０〜３の整数を表し；Ｙ^２はアルキレン基または脂肪族環式基を表し；Ｒは前記と同じであり、Ｒ^１’、Ｒ^２’はそれぞれ独立して水素原子または炭素数１〜５の低級アルキル基を表す。］

[In the above formula, X ′ represents a tertiary alkyl ester type acid dissociable, dissolution inhibiting group, Y represents a lower alkyl group having 1 to 5 carbon atoms, or an aliphatic cyclic group; Y ² represents an alkylene group or an aliphatic cyclic group; R is the same as defined above; R ¹ ′ and R ² ′ each independently represent a hydrogen atom or a lower alkyl group having 1 to 5 carbon atoms; Represents. ]

Wherein, X 'include those of the same tertiary alkyl ester-type acid dissociable, dissolution inhibiting groups as those described above for X ^{1.
R 1 ', R 2',} n, as the Y, respectively, ^{R 1} in the general formula listed in the description of "acetal-type acid dissociable, dissolution inhibiting group" described above ^{(p1) ', R 2'} , n, Y The same thing is mentioned.
The Y ^2, the same groups as those described above for ^{Y 2} in the general formula (a1-0-2).

  Specific examples of the structural units represented by the general formulas (a1-1) to (a1-4) are shown below.

As the structural unit (a1), one type may be used alone, or two or more types may be used in combination.
Among these, the structural unit represented by general formula (a1-1) is preferable, and specifically, (a1-1-1) to (a1-1-6) and (a1-1-35) to (a1- It is more preferable to use at least one selected from the group 1-41).
Furthermore, as the structural unit (a1), in particular, those represented by the following general formula (a1-1-01) including the structural units of the formulas (a1-1-1) to (a1-1-4) The following general formula (a1-1-02) including the structural units of formulas (a1-1-35) to (a1-1-41) is also preferable.

［式中、Ｒは水素原子、低級アルキル基またはハロゲン化低級アルキル基を示し、Ｒ^１１は低級アルキル基を示す。］

[Wherein, R represents a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group, and R ¹¹ represents a lower alkyl group. ]

［式中、Ｒは水素原子、低級アルキル基またはハロゲン化低級アルキル基を示し、Ｒ^１２は低級アルキル基を示す。ｈは１〜３の整数を表す。］

[Wherein, R represents a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group, and R ¹² represents a lower alkyl group. h represents an integer of 1 to 3. ]

In general formula (a1-1-01), R is the same as defined above. The lower alkyl group for R ^{11 is the same as} the lower alkyl group for R, and is preferably a methyl group or an ethyl group.

In general formula (a1-1-02), R is the same as defined above. The lower alkyl group for R ^{12 is the same as} the lower alkyl group for R, preferably a methyl group or an ethyl group, and most preferably an ethyl group. h is preferably 1 or 2, and most preferably 2.

  The proportion of the structural unit (a1) in the component (A1) is preferably 10 to 80 mol%, more preferably 20 to 70 mol%, more preferably 25 to 50 mol%, based on all structural units constituting the component (A1). Is more preferable. By setting it to the lower limit value or more, a pattern can be easily obtained when the resist composition is used, and by setting it to the upper limit value or less, it is possible to balance with other structural units.

・ Structural unit (a2)
The structural unit (a2) is a structural unit derived from an acrylate ester containing a lactone-containing cyclic group.
Here, the lactone-containing cyclic group refers to a cyclic group containing one ring (lactone ring) containing an —O—C (O) — structure. The lactone ring is counted as the first ring, and when it is only the lactone ring, it is called a monocyclic group, and when it has another ring structure, it is called a polycyclic group regardless of the structure.
When the component (A1) is used for forming a resist film, the lactone cyclic group of the structural unit (a2) increases the adhesion of the resist film to the substrate or has an affinity for a developer containing water. It is effective in raising.

As the structural unit (a2), any unit can be used without any particular limitation.
Specifically, examples of the lactone-containing monocyclic group include groups in which one hydrogen atom has been removed from γ-butyrolactone. Examples of the lactone-containing polycyclic group include groups in which one hydrogen atom has been removed from a bicycloalkane, tricycloalkane, or tetracycloalkane having a lactone ring.

  More specifically, examples of the structural unit (a2) include structural units represented by general formulas (a2-1) to (a2-5) shown below.

［式中、Ｒは水素原子、低級アルキル基またはハロゲン化低級アルキル基であり、Ｒ’は水素原子、低級アルキル基、炭素数１〜５のアルコキシ基または−ＣＯＯＲ”であり、前記Ｒ”は水素原子、または炭素数１〜１５の直鎖状、分岐鎖状もしくは環状のアルキルキル基であり、ｍは０または１の整数であり、Ａ”は酸素原子もしくは硫黄原子を含んでいてもよい炭素数１〜５のアルキレン基、酸素原子または硫黄原子である。］

[Wherein, R is a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group, R ′ is a hydrogen atom, a lower alkyl group, an alkoxy group having 1 to 5 carbon atoms, or —COOR ″, wherein R ″ is A hydrogen atom or a linear, branched or cyclic alkylalkyl group having 1 to 15 carbon atoms, m is an integer of 0 or 1, and A ″ is a carbon which may contain an oxygen atom or a sulfur atom. It is an alkylene group of formulas 1 to 5, an oxygen atom or a sulfur atom.]

R in the general formulas (a2-1) to (a2-5) is the same as R in the structural unit (a1).
The lower alkyl group for R ′ is the same as the lower alkyl group for R in the structural unit (a1).
When R ″ is a linear or branched alkyl group, it preferably has 1 to 10 carbon atoms, and more preferably 1 to 5 carbon atoms.
When R ″ is a cyclic alkyl group, it preferably has 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, a fluorine atom or fluorine atom A group in which one or more hydrogen atoms are removed from a polycycloalkane such as monocycloalkane, bicycloalkane, tricycloalkane, tetracycloalkane, etc., which may or may not be substituted with an alkyl group. Specific examples thereof include monocycloalkanes such as cyclopentane and cyclohexane, groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Can be mentioned.
In general formulas (a2-1) to (a2-5), R ′ is preferably a hydrogen atom in view of industrial availability.
Specific examples of the alkylene group having 1 to 5 carbon atoms that may contain an oxygen atom or sulfur atom of A ″ include a methylene group, an ethylene group, an n-propylene group, an isopropylene group, —O—CH ₂ —. _{, -CH 2 -O-CH 2 -} , - S-CH 2 -, - CH 2 -S-CH 2 - , and the like.
Below, the specific structural unit of the said general formula (a2-1)-(a2-5) is illustrated.

In the component (A1), as the structural unit (a2), one type may be used alone, or two or more types may be used in combination.
As the structural unit (a2), at least one selected from the group consisting of structural units represented by the general formulas (a2-1) to (a2-5) is preferable, and the general formulas (a2-1) to (a2) -3) At least 1 sort (s) selected from the group which consists of a structural unit represented by 3) is more preferable. Among them, chemical formulas (a2-1-1), (a2-1-2), (a2-2-1), (a2-2-2), (a2-2-9), (a2-2-10) ), (A2-3-1), (a2-3-2), (a2-3-9) and (a2-3-10) at least one selected from the group consisting of structural units It is preferable to use it.

  The proportion of the structural unit (a2) in the component (A1) is preferably 5 to 60 mol%, more preferably 10 to 50 mol%, based on the total of all structural units constituting the copolymer (A1). 20-50 mol% is more preferable. By making it the lower limit value or more, the effect of containing the structural unit (a2) can be sufficiently obtained, and by making it the upper limit value or less, it is possible to balance with other structural units.

・ Structural unit (a3)
The structural unit (a3) is a structural unit derived from an acrylate ester containing a polar group-containing aliphatic hydrocarbon group.
When the component (A1) has the structural unit (a3), the hydrophilicity of the component (A) is increased, the affinity with the developer is increased, the alkali solubility in the exposed area is improved, and the resolution is improved. Contributes to improvement.
Examples of the polar group include a hydroxyl group, a cyano group, a carboxy group, and a hydroxyalkyl group in which a part of hydrogen atoms of an alkyl group is substituted with a fluorine atom.
Examples of the aliphatic hydrocarbon group include a linear or branched hydrocarbon group having 1 to 10 carbon atoms (preferably an alkylene group) and a polycyclic aliphatic hydrocarbon group (polycyclic group). It is done. As the polycyclic group, for example, a resin for a resist composition for ArF excimer laser can be appropriately selected from among many proposed ones. The polycyclic group preferably has 7 to 30 carbon atoms.
Among them, a structural unit derived from an acrylate ester containing an aliphatic polycyclic group containing a hydroxyalkyl group in which a part of hydrogen atoms of a hydroxyl group, a cyano group, a carboxy group, or an alkyl group is substituted with a fluorine atom Is more preferable. Examples of the polycyclic group include groups in which two or more hydrogen atoms have been removed from bicycloalkane, tricycloalkane, tetracycloalkane and the like. Specific examples include groups in which two or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among these polycyclic groups, there are groups in which two or more hydrogen atoms have been removed from adamantane, groups in which two or more hydrogen atoms have been removed from norbornane, and groups in which two or more hydrogen atoms have been removed from tetracyclododecane. Industrially preferable.

  The structural unit (a3) is derived from a hydroxyethyl ester of acrylic acid when the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a linear or branched hydrocarbon group having 1 to 10 carbon atoms. When the hydrocarbon group is a polycyclic group, a structural unit represented by the following formula (a3-1), a structural unit represented by (a3-2), (a3-3) ) Is preferable.

［式中、Ｒは前記に同じであり、ｊは１〜３の整数であり、ｋは１〜３の整数であり、ｔ’は１〜３の整数であり、ｌは１〜５の整数であり、ｓは１〜３の整数である。］

[Wherein, R is as defined above, j is an integer of 1 to 3, k is an integer of 1 to 3, t ′ is an integer of 1 to 3, and l is an integer of 1 to 5] And s is an integer of 1 to 3. ]

In formula (a3-1), j is preferably 1 or 2, and more preferably 1. When j is 2, it is preferable that the hydroxyl group is bonded to the 3rd and 5th positions of the adamantyl group. When j is 1, it is preferable that the hydroxyl group is bonded to the 3-position of the adamantyl group.
j is preferably 1, and a hydroxyl group bonded to the 3rd position of the adamantyl group is particularly preferred.

  In formula (a3-2), k is preferably 1. The cyano group is preferably bonded to the 5th or 6th position of the norbornyl group.

  In formula (a3-3), t ′ is preferably 1. l is preferably 1. s is preferably 1. These preferably have a 2-norbornyl group or a 3-norbornyl group bonded to the terminal of the carboxy group of acrylic acid. The fluorinated alkyl alcohol is preferably bonded to the 5th or 6th position of the norbornyl group.

As the structural unit (a3), one type may be used alone, or two or more types may be used in combination.
In the component (A1), the proportion of the structural unit (a3) is preferably 5 to 50 mol%, more preferably 5 to 40 mol%, with respect to all the structural units constituting the copolymer (A1). 5 to 25 mol% is more preferable. By setting it to the lower limit value or more, the effect of containing the structural unit (a3) can be sufficiently obtained, and by setting it to the upper limit value or less, it is possible to balance with other structural units.

・ Structural unit (a4)
The component (A1) may contain other structural units (a4) other than the structural units (a1) to (a3) as long as the effects of the present invention are not impaired.
The structural unit (a4) is not particularly limited as long as it is another structural unit that is not classified into the structural units (a1) to (a3) described above, and is for ArF excimer laser and KrF excimer laser (preferably ArF excimer). A number of hitherto known materials can be used for resist resins such as lasers.
As the structural unit (a4), for example, a structural unit derived from an acrylate ester containing a non-acid-dissociable aliphatic polycyclic group is preferable. Examples of the polycyclic group include those exemplified in the case of the structural unit (a1), and for ArF excimer laser and KrF excimer laser (preferably for ArF excimer laser). A number of hitherto known materials can be used as the resin component of the resist composition.
In particular, at least one selected from a tricyclodecanyl group, an adamantyl group, a tetracyclododecanyl group, an isobornyl group, and a norbornyl group is preferable in terms of industrial availability. These polycyclic groups may have a linear or branched alkyl group having 1 to 5 carbon atoms as a substituent.
Specific examples of the structural unit (a4) include those represented by the following general formulas (a4-1) to (a4-5).

［式中、Ｒは前記と同じである。］

[Wherein, R is the same as defined above. ]

  When the structural unit (a4) is contained in the component (A1), the structural unit (a4) is preferably contained in an amount of 1 to 30 mol% based on the total of all the structural units constituting the component (A1). 10 to 20 mol% is more preferable.

  In the present invention, the component (A1) is a resin component (polymer) whose solubility in an alkaline developer is increased by the action of an acid. Examples of suitable resin components (polymers) include the above-described configuration. A copolymer having units (a1), (a2) and (a3). Examples of such a copolymer include a copolymer comprising the structural units (a1), (a2) and (a3), and a structural unit. Examples thereof include a copolymer comprising (a1), (a2), (a3) and (a4).

  In the present invention, the component (A1) is particularly preferably a copolymer (A1-1) containing a combination of structural units represented by the following general formula (A1-1).

［式中、Ｒは前記と同じであり、複数のＲはそれぞれ同じであっても異なっていてもよい。Ｒ^２０は低級アルキル基である。］

[Wherein, R is the same as defined above, and a plurality of R may be the same or different. R ²⁰ is a lower alkyl group. ]

In formula (A1-1), R is the same as defined above. Among them, a hydrogen atom or a methyl group is preferable, and a methyl group is most preferable.
R ²⁰ is a lower alkyl group, which is the same as the lower alkyl group for R, preferably a methyl group or an ethyl group, and most preferably a methyl group.

As the component (A1), one type may be used alone, or two or more types may be used in combination.
The content of the copolymer (A1-1) in the component (A1) is preferably 70% by mass or more, more preferably 80% by mass or more, and may be 100% by mass. Especially, it is most preferable that it is 100 mass%. By being above the lower limit of the range, the lithography properties are further improved when a positive resist composition is obtained.
As the component (A1), alkali-soluble resin components other than the copolymer (A1-1), for example, other polymer compounds used in conventional positive resist compositions can be used.

The component (A1) can be obtained by polymerizing a monomer for deriving each structural unit by a known radical polymerization using a radical polymerization initiator such as azobisisobutyronitrile (AIBN).
Further, for the component (A1), in the polymerization, a chain transfer agent such as HS—CH ₂ —CH ₂ —CH ₂ —C (CF ₃ ) ₂ —OH is used in combination, so that the terminal A —C (CF ₃ ) ₂ —OH group may be introduced into the. As described above, a copolymer introduced with a hydroxyalkyl group in which a part of hydrogen atoms of the alkyl group is substituted with a fluorine atom reduces development defects and LER (line edge roughness: uneven unevenness of line side walls). It is effective in reducing

The mass average molecular weight (Mw) of the component (A1) (polystyrene conversion standard by gel permeation chromatography) is not particularly limited, but is preferably 2000 to 50000, more preferably 3000 to 30000, and 5000 to 20000. Most preferred. If it is smaller than the upper limit of this range, there is sufficient solubility in a resist solvent to be used as a resist, and if it is larger than the lower limit of this range, dry etching resistance and resist pattern cross-sectional shape are good.
Further, the dispersity (Mw / Mn) is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.2 to 2.5. In addition, Mn shows a number average molecular weight.

  In the resist composition of the present invention, the content of the component (A1) may be adjusted according to the resist film thickness to be formed.

<(B) component>
In the resist composition of the present invention, the component (B) includes two different acid generators (B1) (hereinafter referred to as the component (B1)) having an acid dissociable group in the cation part and (B2) ( (Hereinafter referred to as component (B2)).
The acid dissociable group in the components (B1) and (B2) is an organic group that can be dissociated by the action of an acid, and is not particularly limited as long as it is such as, for example, for chemically amplified resists. And those proposed as acid dissociable, dissolution inhibiting groups for the base resin. Specific examples thereof include the same acid dissociable, dissolution inhibiting groups exemplified in the structural unit (a1).

[(B1) component]
The component (B1) is not particularly limited as long as it has an acid dissociable group. For example, an acid dissociable group-containing group has been proposed as an acid generator for a chemically amplified resist. The one introduced is mentioned. Here, the acid-dissociable group-containing group is a group containing an acid-dissociable group in the structure thereof, and may be an acid-dissociable group itself. (A group or atom that remains bonded to the acid generator even after the acid dissociable group is dissociated).
The method for introducing an acid dissociable group-containing group into the acid generator is not particularly limited, and a known method can be used. For example, an acid generator having a hydrophilic group such as a hydroxyl group or a carboxy group is prepared, and the hydrogen atom of the hydrophilic group is substituted with an acid-dissociable group-containing group.

As the component (B1), those having high transparency with respect to the exposure wavelength band (particularly the wavelength band of ArF excimer laser) are preferable. The component (B1) preferably has higher transparency to the exposure wavelength band than the component (B2) used in combination, and the absorbance at the wavelength 193 nm of the component (B1) is the same as that of the component (B2) under the same measurement conditions. Lower than that is preferable. When comparing the absorbance at the wavelength of 193 nm of the component (B1) and the component (B2) under the same measurement conditions, for example, a resist having the same composition except that either the component (B1) or the component (B2) is used. The composition may be applied and baked on a quartz substrate using a spinner or the like under the same conditions to form a resist film, and the absorbance at a wavelength of 193 nm may be measured and compared for the resist film. The temperature and time for baking are not particularly limited, but the temperature is preferably 80 to 150 ° C., and the time is preferably 40 to 120 seconds, more preferably 60 to 90 seconds.
The absorbance at 193 nm of the component (B1) is preferably less than 80% of the absorbance at 193 nm of the component (B2), more preferably less than 70%, and particularly preferably less than 65%. By setting the absorbance within such a range, the resist pattern has good lithography characteristics such as depth of focus (DOF).

Preferred component (B1) has a cation moiety containing a dibenzothiophene skeleton in addition to the acid-dissociable group-containing group introduced so far as an acid generator for a chemically amplified resist. Is mentioned. Such a component (B1) is usually more transparent to the exposure wavelength band than an acid generator having triphenylsulfonium (TPS) or the like in the cation portion.
Especially, as a cation part containing a dibenzothiophene frame | skeleton, what is represented by the following general formula (b'-8) is preferable.

［式中、Ｒ^４０１は酸解離性基であり、Ｒ^４１〜Ｒ^４３はそれぞれ独立してハロゲン原子、ハロゲン化アルキル基、アルキル基、アセチル基、アルコキシ基、カルボキシ基、またはヒドロキシアルキル基であり、Ｑは２価の連結基または単結合であり；ｎ_０は１〜３の整数であり、ｎ_１〜ｎ_３はそれぞれ独立して０〜３の整数であり、ただし、ｎ_０＋ｎ_１は５以下である。］

[Wherein, R ⁴⁰¹ is an acid dissociable group, and R ^{41 to} R ⁴³ are each independently a halogen atom, a halogenated alkyl group, an alkyl group, an acetyl group, an alkoxy group, a carboxy group, or a hydroxyalkyl group. , Q is a divalent linking group or a single bond; n ₀ is an integer of _{1 to 3} , n _{1 to} n ₃ are each independently an integer of 0 to 3, provided that n ₀ + n ₁ is 5 or less. ]

In the general formula (b′-8), R ⁴⁰¹ is an acid dissociable group, and R ⁴¹ , R ⁴² and R ⁴³ are each independently a halogen atom, a halogenated alkyl group, an alkyl group, an acetyl group, or an alkoxy group. , A carboxy group, or a hydroxyalkyl group.
The acid dissociable group of R ⁴⁰¹ is not particularly limited as long as it is an organic group that can be dissociated by the action of an acid, but is a cyclic or chain tertiary alkyl ester type acid dissociable group; an acetal type such as an alkoxyalkyl group Examples include acid dissociable groups, and among these, tertiary alkyl ester type acid dissociable groups are preferable.
R ⁴⁰¹ is preferably an acid dissociable group represented by the following general formula (b′-8-0).

［式中、複数のＲ^５０１はそれぞれ同じであっても異なっていても良く、少なくとも１つは炭素数１〜４の直鎖状もしくは分岐鎖状のアルキル基であり；残りの２つのＲ^５０１は、それぞれ独立して炭素数１〜４の直鎖状もしくは分岐鎖状のアルキル基、または炭素数４〜２０の１価の脂肪族環式基であるか、あるいは、前記残りの２つのＲ^５０１は相互に結合して、それぞれが結合している炭素原子と共に炭素数４〜２０の２価の脂肪族環式基を形成している。］

[Wherein, the plurality of R ⁵⁰¹ may be the same or different, and at least one is a linear or branched alkyl group having 1 to 4 carbon atoms; the remaining two R ⁵⁰¹ Are each independently a linear or branched alkyl group having 1 to 4 carbon atoms, or a monovalent aliphatic cyclic group having 4 to 20 carbon atoms, or the remaining two R ⁵⁰¹ are bonded to each other to form a divalent aliphatic cyclic group having 4 to 20 carbon atoms together with the carbon atoms to which they are bonded. ]

Examples of the aliphatic cyclic group include groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as monocycloalkane, bicycloalkane, tricycloalkane, and tetracycloalkane. Specific examples include monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. More specifically, a cyclopentyl group, a cyclohexyl group, a norbornyl group, an adamantyl group, and the like can be given.
Examples of the linear or branched alkyl group having 1 to 4 carbon atoms include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a tert-butyl group.

As the acid dissociable group represented by the general formula (b′-8-0), a plurality of R ⁵⁰¹ are each independently a linear or branched alkyl group having 1 to 4 carbon atoms. , Tert-butyl group, tert-pentyl group, tert-hexyl group and the like.

As the acid dissociable group represented by the general formula (b′-8-0), at least one of the plurality of R ^{501 is} a linear or branched alkyl group having 1 to 4 carbon atoms, and the remaining 2 R ⁵⁰¹ is independently a linear or branched alkyl group having 1 to 4 carbon atoms or a monovalent aliphatic cyclic group having 4 to 20 carbon atoms. 1-adamantyl) -1-methylethyl group, 1- (1-adamantyl) -1-methylpropyl group, 1- (1-adamantyl) -1-methylbutyl group, 1- (1-adamantyl) -1-methylpentyl Group: 1- (1-cyclopentyl) -1-methylethyl group, 1- (1-cyclopentyl) -1-methylpropyl group, 1- (1-cyclopentyl) -1-methylbutyl group, 1- (1-cyclopentyl) -1-methyl pliers Groups: 1- (1-cyclohexyl) -1-methylethyl group, 1- (1-cyclohexyl) -1-methylpropyl group, 1- (1-cyclohexyl) -1-methylbutyl group, 1- (1-cyclohexyl) -1-methylpentyl group, and the like.

As the acid dissociable group represented by general formula (b'-8-0), among the plurality of ^{R 501,} 1 single ^{R 501} is a straight-chain or branched alkyl group having 1 to 4 carbon atoms Two R ^501s bonded to each other to form a divalent aliphatic cyclic group having 4 to 20 carbon atoms together with the carbon atom to which each R ⁵⁰¹ is bonded include 2-methyl-2- 2-alkyl-2-adamantyl groups such as adamantyl group and 2-ethyl-2-adamantyl group, 1-methyl-1-cyclopentyl group, 1-ethyl-1-cyclopentyl group, 1-methyl-1-cyclohexyl group, Examples include 1-alkyl-1-cycloalkyl groups such as 1-ethyl-1-cyclohexyl group.

Among these, as the acid dissociable group represented by the general formula (b′-8-0), among the plurality of R ⁵⁰¹ , one R ⁵⁰¹ is linear or branched having 1 to 4 carbon atoms. In which two R ⁵⁰¹ 's are bonded to each other to form a divalent aliphatic cyclic group having 4 to 20 carbon atoms together with the carbon atoms to which they are bonded, A 2-methyl-2-adamantyl group is preferred.

In R ⁴¹ , R ⁴² and R ⁴³ , the alkyl group is preferably a lower alkyl group having 1 to 5 carbon atoms, more preferably a linear or branched alkyl group, and a methyl group, an ethyl group, or a propyl group. , An isopropyl group, an n-butyl group, a tert-butyl group, a tert-pentyl group, or an isopentyl group, more preferably a methyl group.
The alkoxy group is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a linear or branched alkoxy group, and particularly preferably a methoxy group or an ethoxy group.
The hydroxyalkyl group is preferably a group in which one or more hydrogen atoms of the above alkyl group are substituted with a hydroxy group, and examples thereof include a hydroxymethyl group, a hydroxyethyl group, a hydroxypropyl group, and the like.
Examples of the halogen atom include a fluorine atom, a chlorine atom, an iodine atom, and a bromine atom, and a fluorine atom is preferable.
The halogenated alkyl group is preferably a halogenated alkyl group having 1 to 5 carbon atoms, more preferably a halogenated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, a trifluoromethyl group, Most preferably, it is a pentafluoroethyl group.

n ₀ is an integer of 1 to 3, preferably 1 or 2, and more preferably 1.
n ₁ is an integer of 0 to 3, preferably 1 or 2, and more preferably 2.
n ₂ and n ₃ are each independently an integer of 0 to 3, preferably 0 or 1 each independently, more preferably 0.
However, n ₀ + n ₁ is 5 or less.

In the general formula (b′-8), Q is a divalent linking group or a single bond.
Examples of the divalent linking group include a methylene group, ethylene group, propylene group, isopropylene group, cyclopropylene group, n-butylene group, isobutylene group, cyclopentylene group, cyclohexylene group, cycloheptylene group, C1-C8 linear, branched or cyclic alkylene groups, such as a cyclooctylene group, are mentioned. Further, the divalent linking group in Q may contain an oxygen atom, and examples thereof include an ether group and an ester group. Among these, a linear alkylene group is preferable from the viewpoint of ease of synthesis, and a methylene group is particularly preferable.
In the general formula (b′-8), Q is preferably a divalent linking group.

The anion part of the component (B1) is not particularly limited, and those known as the anion part of the onium salt acid generator can be appropriately used. For example, an anion represented by the general formula “R ¹⁴ SO ₃ ^— (R ¹⁴ represents a linear, branched, or cyclic alkyl group or a halogenated alkyl group)” or a general formula “R ¹ — O—Y ¹ —SO ₃ ^— (R ¹ is a monovalent aliphatic hydrocarbon group, monovalent aromatic organic group, or hydroxyalkyl group; Y ¹ is an optionally substituted fluorine atom having 1 to 1 carbon atoms; An anion represented by 4) can be used.

In the general formula “R ¹⁴ SO ₃ ⁻ ”, R ¹⁴ represents a linear, branched or cyclic alkyl group, a halogenated alkyl group, an aryl group, or an alkenyl group.
The linear or branched alkyl group as R ¹⁴ preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and 1 to 4 carbon atoms. Most preferred.
The cyclic alkyl group as R ¹⁴ preferably has 4 to 15 carbon atoms, more preferably 4 to 10 carbon atoms, and most preferably 6 to 10 carbon atoms.
R ¹⁴ is preferably a halogenated alkyl group. That is, the anion part of the component (B1) is preferably a halogenated alkyl sulfonate ion. An alkyl halide is one in which part or all of the hydrogen atoms in the alkyl are substituted with halogen atoms. Here, examples of the halogenated alkyl include those in which a halogen atom is substituted for the same as the “alkyl group” in R ⁴¹ , R ⁴² and R ⁴³ . Examples of the halogen atom to be substituted include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. In the halogenated alkyl, it is desirable that 50 to 100% of the total number of hydrogen atoms is substituted with halogen atoms, and it is more preferable that all are substituted.
Here, the halogenated alkyl group is preferably a fluorinated alkyl group. The fluorinated alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 4 carbon atoms. The fluorination rate of the fluorinated alkyl group (ratio of the number of fluorine atoms substituted by fluorination to the total number of hydrogen atoms in the alkyl group before fluorination, the same shall apply hereinafter) is preferably 10 to 100%. More preferably, it is 50 to 100%, and in particular, those in which all hydrogen atoms are substituted with fluorine atoms are preferred because the strength of the acid becomes strong.
The aryl group as R ¹⁴ is preferably an aryl group having 6 to 20 carbon atoms which may have a substituent. Examples of the substituent that may have include a halogen atom, a hetero atom, and an alkyl group. You may have multiple substituents.
The alkenyl group as R ¹⁴ is preferably an alkenyl group having 2 to 10 carbon atoms which may have a substituent. Examples of the substituent that may have include a halogen atom, a hetero atom, and an alkyl group. You may have multiple substituents.

In the general formula “R ¹ —O—Y ¹ —SO ₃ ^— ”, R ¹ is a monovalent aliphatic hydrocarbon group, aromatic organic group, or hydroxyalkyl group; and Y ¹ is fluorine-substituted. Or an alkylene group having 1 to 4 carbon atoms.

Examples of the monovalent aliphatic hydrocarbon group for R ¹ include a linear, branched or cyclic monovalent saturated hydrocarbon group having 1 to 15 carbon atoms, or a linear chain having 2 to 5 carbon atoms. Or branched monovalent aliphatic unsaturated hydrocarbon group.

Examples of the linear monovalent saturated hydrocarbon group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, and a decanyl group.
Examples of the branched monovalent saturated hydrocarbon group include 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1 -Ethylbutyl group, 2-ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group and the like can be mentioned.
The cyclic monovalent saturated hydrocarbon group may be either a polycyclic group or a monocyclic group, for example, one from a polycycloalkane such as a monocycloalkane, a bicycloalkane, a tricycloalkane, or a tetracycloalkane. And a group in which a hydrogen atom is removed. More specifically, one hydrogen atom was removed from a monocycloalkane such as cyclopentane, cyclohexane, cycloheptane, and cyclooctane, and a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Group and the like.
Examples of the linear monovalent unsaturated hydrocarbon group include a propenyl group (allyl group) and a butynyl group.
Examples of the branched monovalent unsaturated hydrocarbon group include a 1-methylpropenyl group and a 2-methylpropenyl group.
The number of carbon atoms of the monovalent aliphatic hydrocarbon group R ¹ is 3-4 and most preferably 3.

Examples of the monovalent aromatic organic group for R ¹ include hydrogen from an aromatic hydrocarbon ring such as a phenyl group, a biphenyl group, a fluorenyl group, a naphthyl group, an anthryl group, and a phenanthryl group. An aryl group in which one atom is removed; a heteroaryl group in which a part of carbon atoms constituting the ring of these aryl groups is substituted with a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom. These aryl groups and heteroaryl groups may have a substituent such as an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group, an alkoxy group, a hydroxyl group, or a halogen atom. The alkyl group or halogenated alkyl group in the substituent preferably has 1 to 8 carbon atoms, and more preferably 1 to 4 carbon atoms. The halogenated alkyl group is preferably a fluorinated alkyl group. Examples of the halogen atom include a fluorine atom, a chlorine atom, an iodine atom, and a bromine atom, and a fluorine atom is preferable.

The hydroxyalkyl group for R ¹ is a group in which at least one hydrogen atom of a linear, branched or cyclic monovalent saturated hydrocarbon group is substituted with a hydroxyl group. Those in which one or two hydrogen atoms of a linear or branched monovalent saturated hydrocarbon group are substituted with a hydroxyl group are preferred. Specific examples include 1-hydroxypropyl group, 2-hydroxypropyl group, 3-hydroxypropyl group, 2,3-dihydroxypropyl group, and the like.
R The number of carbon atoms of the monovalent hydroxyalkyl group ¹ is preferably 3 to 10, more preferably from 3 to 8, 3 to 6 is particularly preferred.

Examples of the alkylene group having 1 to 4 carbon atoms which may be fluorine-substituted for Y ¹ include —CF ₂ —, —CF ₂ CF ₂ —, —CF ₂ CF ₂ CF ₂ —, and —CF (CF ₃ ) CF. _{2 -, - CF (CF 2} CF 3) -, - C (CF 3) 2 -, - CF 2 CF 2 CF 2 CF 2 -, - CF (CF 3) CF 2 CF 2 -, - CF 2 CF ( CF ₃ ) CF ₂ —, —CF (CF ₃ ) CF (CF ₃ ) —, —C (CF ₃ ) ₂ CF ₂ —, —CF (CF ₂ CF ₃ ) CF ₂ —, —CF (CF ₂ CF _{2 CF 3) -, - C (} CF 3) (CF 2 CF 3) -; - CHF -, - CH 2 CF 2 -, - CH 2 CH 2 CF 2 -, - CH 2 CF 2 CF 2 -, - CH (CF ₃ ) CH ₂ —, —CH (CF ₂ CF ₃ ) —, —C (CH ₃ ) (CF _{3 ) -, - CH 2 CH 2} CH 2 CF 2 -, - CH 2 CH 2 CF 2 CF 2 -, - CH (CF 3) CH 2 CH 2 -, - CH 2 CH (CF 3) CH 2 -, - CH (CF ₃ ) CH (CF ₃ ) —, —C (CF ₃ ) ₂ CH ₂ —; —CH ₂ —, —CH ₂ CH ₂ —, —CH ₂ CH ₂ CH ₂ —, —CH (CH ₃ ) _{CH 2 -, - CH (CH} 2 CH 3) -, - C (CH 3) 2 -, - CH 2 CH 2 CH 2 CH 2 -, - CH (CH 3) CH 2 CH 2 -, - CH 2 CH _{(CH 3) CH 2 -,} - CH (CH 3) CH (CH 3) -, - C (CH 3) 2 CH 2 -, - CH (CH 2 CH 3) CH 2 -, - CH (CH 2 CH _{2 CH 3) -, - C} (CH 3) (CH 2 CH 3) -; and the like.

Further, the Y ^1, the fluorine substituents on these alkylene group having 1 to 4 carbon atoms, it is preferred that the carbon atom bonded to S is fluorinated, as such a fluorinated alkylene group, - _{CF 2 -, - CF 2 CF} 2 -, - CF 2 CF 2 CF 2 -, - CF (CF 3) CF 2 -, - CF 2 CF 2 CF 2 CF 2 -, - CF (CF 3) CF 2 CF _{2 -, - CF 2 CF (} CF 3) CF 2 -, - CF (CF 3) CF (CF 3) -, - C (CF 3) 2 CF 2 -, - CF (CF 2 CF 3) CF 2 - _{; -CH 2 CF 2 -, -} CH 2 CH 2 CF 2 -, - CH 2 CF 2 CF 2 -; - CH 2 CH 2 CH 2 CF 2 -, - CH 2 CH 2 CF 2 CF 2 -, - CH _{2 CF 2 CF 2 CF 2 -} ; etc. Ageruko the Can.
Of _{these, -CF 2 CF 2 -, -} CF 2 CF 2 CF 2 -, or _CH 2 _CF 2 CF ₂ - is preferable, _-CF 2 CF ₂ - or _-CF 2 _CF 2 CF ₂ - is more preferable, -CF ₂ CF ₂ - is particularly preferred.

  As the anion part of the component (B1), an anion represented by the following general formula (b-3), an anion represented by the following general formula (b-4), or the like can be used.

[Wherein X ″ represents an alkylene group having 2 to 6 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom; Y ″ and Z ″ each independently represent at least one hydrogen atom as a fluorine atom; Represents an alkyl group having 1 to 10 carbon atoms and substituted with

X ″ is a linear or branched alkylene group in which at least one hydrogen atom is substituted with a fluorine atom, and the alkylene group preferably has 2 to 6 carbon atoms, more preferably 3 carbon atoms. ~ 5, most preferably 3 carbon atoms.
Y ″ and Z ″ are each independently a linear or branched alkyl group in which at least one hydrogen atom is substituted with a fluorine atom, and the alkyl group preferably has 1 to 10 carbon atoms. More preferably, it has 1 to 7 carbon atoms, and most preferably 1 to 3 carbon atoms.
The carbon number of the alkylene group of X ″ or the carbon number of the alkyl group of Y ″ and Z ″ is preferably as small as possible because the solubility in the resist solvent is good within the above carbon number range.
In addition, in the alkylene group of X ″ or the alkyl group of Y ″ and Z ″, as the number of hydrogen atoms substituted with fluorine atoms increases, the strength of the acid increases, and high-energy light or electron beam of 200 nm or less The ratio of fluorine atoms in the alkylene group or alkyl group, that is, the fluorination rate is preferably 70 to 100%, more preferably 90 to 100%, and most preferably all. Are a perfluoroalkylene group or a perfluoroalkyl group in which a hydrogen atom is substituted with a fluorine atom.

As the component (B1), a plurality of R ⁵⁰¹ are each independently a linear or branched alkyl group having 1 to 4 carbon atoms and Q is a single bond. The compounds represented by (b1-81) to formula (b1-89) are exemplified, and preferred specific examples of those in which Q is a divalent linking group include the following formulas (b1-121) to (b1- 129).

As the component (B1), at least one of the plurality of R ⁵⁰¹ is a linear or branched alkyl group having 1 to 4 carbon atoms, and the remaining two R ^501s are each independently selected from 1 to Preferred examples of the linear or branched alkyl group having 4 or a monovalent aliphatic cyclic group having 4 to 20 carbon atoms and Q being a single bond include the following formulas (b1- 91) to compounds represented by formula (b1-99), and preferred specific examples of those in which Q is a divalent linking group include the following formulas (b1-131) to (b1-139). And the compounds represented.

As the component (B1), at least one of the plurality of R ⁵⁰¹ is a linear or branched alkyl group having 1 to 4 carbon atoms, and the remaining two R ^501s are bonded to each other, and each is bonded Preferred examples of those in which a divalent aliphatic cyclic group having 4 to 20 carbon atoms is formed together with the carbon atom and Q is a single bond include the following formulas (b1-101) to (b1- 119), and preferred specific examples of those in which Q is a divalent linking group include compounds represented by the following formulas (b1-141) to (b1-159). .

  Among these, as the component (B1), a compound represented by the chemical formula (b1-141) is preferable.

<Method for producing component (B1)>
Among the components (B1) having a cation moiety represented by the general formula (b′-8), those in which Q is a single bond can be produced, for example, as follows.
In an organic solvent (for example, dichloromethane, tetrahydrofuran, etc.), a compound represented by the following general formula (b1-5) (hereinafter referred to as intermediate compound (b1-5)), the following general formula (b1-8-20) And an amine catalyst (for example, N, N-dimethylaminopyridine, triethylamine, etc.) are added and reacted at 5 to 50 ° C. for 10 minutes to 12 hours, more preferably 30 minutes to 3 hours, The reaction product is washed with dilute hydrochloric acid, water, etc., and obtained by, for example, dropping an organic solvent (eg, dichloromethane, tetrahydrofuran, etc.) solution of the reaction product into a poor solvent (eg, hexane, dibutyl ether, etc.). it can.

［式中、Ｒ^４１は、上記（ｂ’−８）式中のＲ^４１と同様であり；ｎ_０、ｎ_１は、上記（ｂ’−８）式中のｎ_０、ｎ_１と同様であり、Ｒ^４２およびＲ^４３は、上記（ｂ’−８）式中のＲ^４２およびＲ^４３と同様であり；ｎ_２およびｎ_３は上記（ｂ’−８）式中のｎ_２およびｎ_３と同様であり；Ｘ⁻は、前記（Ｂ１）成分のアニオン部である。］

^{Wherein, R 41} is the (b'-8) is the same as ^{R 41} in the _formula; n 0, _{n 1} is the same as _n 0, _{n 1} in the above (b'-8) expression ^{There, R 42} and ^{R 43} are the (b'-8) is the same as ^{R 42} and ^{R 43} in the formula; _{n 2} and _{n 3 n 2} and _{n 3} in the above (b'-8) expression X ⁻ represents the anion moiety of the component (B1). ]

［式中、Ｒ^４０１は、上記（ｂ’−８）式中のＲ^４０１と同様である。］

^{Wherein, R 401} is the same as ^{R 401} mentioned above (b'-8) in the expression. ]

Moreover, among (B1) component which has a cation part represented by the said general formula (b'-8), what Q is a bivalent coupling group can be manufactured as follows, for example.
An intermediate compound (b1-5) and a base (for example, sodium hydride) are added into an organic solvent (for example, dichloromethane, tetrahydrofuran, etc.), and then the general formula “Br—Q—C (═O) —O— R ⁴⁰¹ (wherein Q and R ⁴⁰¹ are as defined above) "and the like are added and reacted under reflux for 1 to 40 hours, more preferably 10 to 30 hours. The product is added to water and extracted with an organic solvent (for example, dichloromethane), and then the organic layer is concentrated, dissolved in an organic solvent such as dichloromethane, washed with dilute hydrochloric acid, water, and the like. It can be obtained by dropping into dibutyl ether or the like).

  The intermediate compound (b1-5) is, for example, after adding a compound represented by the following general formula (b1-5-20) into a methanesulfonic acid solution of diphosphorus pentoxide and cooling to near room temperature. The compound represented by the following general formula (b1-5-21) is slowly added, and the mixture is allowed to react at room temperature for 2 to 40 hours, more preferably 5 to 20 hours. The reaction product is washed with a mixed solution of water and an organic solvent (for example, dichloromethane, chlorobenzene, iodobenzene, etc.), and the aqueous phase is taken out, for example, a potassium salt represented by the following general formula (b1-5-22) Can be obtained by reacting at room temperature for 0.5 to 8 hours, more preferably 1.0 to 4 hours.

［式中、Ｒ^４１は、上記（ｂ’−８）式中のＲ^４１と同様であり；ｎ_０、ｎ_１は、上記（ｂ’−８）式中のｎ_０、ｎ_１と同様である。］

^{Wherein, R 41} is the (b'-8) is the same as ^{R 41} in the _formula; n 0, _{n 1} is the same as _n 0, _{n 1} in the above (b'-8) expression is there. ]

［式中、Ｒ^４２およびＲ^４３は、上記（ｂ’−８）式中のＲ^４２およびＲ^４３と同様であり；ｎ_２およびｎ_３は上記（ｂ’−８）式中のｎ_２およびｎ_３と同様である。］

^{Wherein, R 42} and ^{R 43} are the (b'-8) is the same as ^{R 42} and ^{R 43} in the formula; _{n 2} and _{n 3} are the (b'-8) _{n 2} and in formula is the same as that of the n _3. ]

^{K + X - ··· (b1-5-22)} [X - are the same as described above. ]

[(B2) component]
The component (B2) is not particularly limited as long as it has an acid-dissociable group and is different from the component (B1). For example, as in the case of the component (B1), acid generation for chemically amplified resists has been performed so far. What has been proposed as an agent includes an acid-dissociable group-containing group.
And as for (B2) component, what differs in the structure of a cation part at least from (B1) component is preferable, and what a cation part does not contain a dibenzothiophene skeleton is more preferable.

  As the component (B2), those having high sensitivity to the exposure wavelength band (particularly the wavelength band of ArF excimer laser) are preferable, and those having higher sensitivity than the component (B1) to be used together are preferable.

  As a preferable component (B2), in addition to those in which an acid dissociable group-containing group has been introduced to those previously proposed as acid generators for chemically amplified resists, the following general formula (b′-14) is used. The thing which has the cation part represented is mentioned. Such a component (B2) usually enables high contrast in the exposed / non-exposed areas of the resist film.

［式中、Ｒ^７”〜Ｒ^９”は、それぞれ独立に、アリール基またはアルキル基を表し；Ｒ^７”〜Ｒ^９”のうち、いずれか２つが相互に結合して式中のイオウ原子と共に環を形成してもよく（ただし、ジベンゾチオフェン骨格は除く）；Ｒ^７”〜Ｒ^９”のうち少なくとも１つは、水素原子の一部または全部がアルコキシアルキルオキシ基またはアルコキシカルボニルアルキルオキシ基で置換された置換アリール基である。］

[Wherein, R ⁷ ″ to R ⁹ ″ each independently represents an aryl group or an alkyl group; any two of R ⁷ ″ to R ⁹ ″ are bonded to each other together with a sulfur atom in the formula A ring may be formed (excluding the dibenzothiophene skeleton); at least one of R ⁷ ″ to R ⁹ ″ is a part or all of hydrogen atoms being an alkoxyalkyloxy group or an alkoxycarbonylalkyloxy group. A substituted aryl group. ]

In the general formula (b′-14), R ⁷ ″ to R ⁹ ″ each independently represents an aryl group or an alkyl group. However, at least one of R ⁷ ″ to R ⁹ ″ is a substituted aryl group in which part or all of the hydrogen atoms are substituted with an alkoxyalkyloxy group or an alkoxycarbonylalkyloxy group.
The aryl group for R ⁷ ″ to R ⁹ ″ is not particularly limited, and is, for example, an aryl group having 6 to 20 carbon atoms. A substituent other than the group and the alkoxycarbonylalkyloxy group, for example, an alkyl group, an alkoxy group, a halogen atom, a hydroxyl group and the like may or may not be substituted. Such an aryl group is preferably an aryl group having 6 to 10 carbon atoms because it can be synthesized at a low cost. Specific examples include a phenyl group and a naphthyl group.
The alkyl group that may be substituted for the hydrogen atom of the aryl group is preferably an alkyl group having 1 to 5 carbon atoms, and is a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. Is more preferable, and a methyl group is most preferable.
As the alkoxy group that may be substituted for the hydrogen atom of the aryl group, an alkoxy group having 1 to 5 carbon atoms is preferable, and a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, Most preferred is a tert-butoxy group.
The halogen atom that may be substituted for the hydrogen atom of the aryl group is preferably a fluorine atom.
The alkyl group for R ⁷ ″ to R ⁹ ″ is not particularly limited, and examples thereof include a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms. It is preferable that it is C1-C5 from the point which is excellent in resolution. Specific examples include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an n-pentyl group, a cyclopentyl group, a hexyl group, a cyclohexyl group, a nonyl group, and a decanyl group. A methyl group is preferable because it is excellent in resolution and can be synthesized at low cost.

At least one of R ⁷ ″ to R ⁹ ″ is a substituted aryl group in which part or all of the hydrogen atoms of the aryl group are substituted with an alkoxyalkyloxy group or an alkoxycarbonylalkyloxy group. R 7 ^{"~R 9"} 2 or more of the may be the substituted aryl group, but is most preferably any one of R 7 ^{"~R 9"} is the substituted aryl group.

  Examples of the alkoxyalkyloxy group in which a hydrogen atom is substituted in the substituted aryl group include those represented by the following general formula (b′-14-1).

［式中、Ｒ^４７およびＲ^４８はそれぞれ独立して水素原子または直鎖状もしくは分岐鎖状のアルキル基であり、Ｒ^４９はアルキル基であり、Ｒ^４８およびＲ^４９は相互に結合して一つの環構造を形成していても良い。ただし、Ｒ^４７およびＲ^４８のうち少なくとも１つは水素原子である。］

[Wherein, R ⁴⁷ and R ⁴⁸ are each independently a hydrogen atom or a linear or branched alkyl group, R ⁴⁹ is an alkyl group, and R ⁴⁸ and R ⁴⁹ are bonded to each other. Two ring structures may be formed. However, at least one of R ⁴⁷ and R ⁴⁸ is a hydrogen atom. ]

In the formula, R ⁴⁷ and R ⁴⁸ are each independently a hydrogen atom or a linear or branched alkyl group, provided that at least one of R ⁴⁷ and R ⁴⁸ is a hydrogen atom.
In R ⁴⁷ and R ⁴⁸ , the alkyl group preferably has 1 to 5 carbon atoms, preferably an ethyl group or a methyl group, and most preferably a methyl group.
One of R ⁴⁷ and R ⁴⁸ is preferably a hydrogen atom, the other is preferably a hydrogen atom or a methyl group, and both R ⁴⁷ and R ⁴⁸ are particularly preferably hydrogen atoms.
The alkyl group for R ⁴⁹ preferably has 1 to 15 carbon atoms and may be linear, branched or cyclic.
The linear or branched alkyl group for R ⁴⁹ preferably has 1 to 5 carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group. Can be mentioned.
The cyclic alkyl group for R ⁴⁹ preferably has 4 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, a monocycloalkane, bicycloalkane, tricycloalkane, tetracycloalkane, etc., which may or may not be substituted with an alkyl group having 1 to 5 carbon atoms, a fluorine atom or a fluorinated alkyl group, etc. And a group obtained by removing one or more hydrogen atoms from the polycycloalkane. Examples of the monocycloalkane include cyclopentane and cyclohexane. Examples of the polycycloalkane include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among them, a group obtained by removing one or more hydrogen atoms from adamantane is preferable.

R ⁴⁸ and R ⁴⁹ may be bonded to each other to form one ring structure. In this case, a cyclic group is formed by R ⁴⁸ , R ⁴⁹ , the oxygen atom to which R ⁴⁹ is bonded, and the carbon atom to which the oxygen atom and R ⁴⁸ are bonded. The cyclic group is preferably a 4- to 7-membered ring, and more preferably a 4- to 6-membered ring.

  Examples of the alkoxycarbonylalkyloxy group in which a hydrogen atom is substituted in the substituted aryl group include those represented by the following general formula (b′-14-2).

［式中、Ｒ^５０は直鎖状もしくは分岐鎖状のアルキレン基であり、Ｒ^５１は酸解離性基である。］

[Wherein, R ⁵⁰ represents a linear or branched alkylene group, and R ⁵¹ represents an acid dissociable group. ]

The linear or branched alkylene group for R ⁵⁰ preferably has 1 to 5 carbon atoms, such as a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, or a 1,1-dimethylethylene group. Among them, a methylene group is particularly preferable.
The acid dissociable group in R ⁵¹ is not particularly limited as long as it is an organic group that can be dissociated by the action of an acid, and R is an acid dissociable group in the general formula (b′-8) in the component (B1). _{The same as 401} .

  In the substituted aryl group, the number of alkoxyalkyloxy groups or alkoxycarbonylalkyloxy groups substituted with hydrogen atoms is preferably 2 or less, and most preferably 1.

R ⁷ ″ to R ⁹ ″ other than the substituted aryl group are each preferably a phenyl group or a naphthyl group, and most preferably a phenyl group.

Any one of R ⁷ ″ to R ⁹ ″ may be bonded to each other to form a ring other than the dibenzothiophene skeleton together with the sulfur atom in the formula. In this case, it is preferable to form a 3- to 10-membered ring including a sulfur atom, and it is particularly preferable to form a 5- to 7-membered ring.

  The anion part of the component (B2) is not particularly limited, and may be the same as the component (B1).

  Specific examples preferable as the component (B2) are given below.

  Among these, as the component (B2), a compound represented by the chemical formula (b1-14-401) is preferable.

<Method for producing component (B2)>
The component (B2) having a cation moiety represented by the general formula (b′-14) (hereinafter referred to as compound (b1-14)) can be produced, for example, as follows. That is, the following general formulas (b1-14-01) and (b1-14) are contained in a solution of an organic acid H ⁺ B ⁻ (B ⁻ represents an anion part of an organic acid such as a methanesulfonate ion). −02) and the reaction is carried out, and then pure water and an organic solvent (for example, dichloromethane, tetrahydrofuran, etc.) are added to recover the organic layer. From the organic layer, the following general formula (b1- 14-03) is obtained.
Next, the compound represented by the general formula (b1-14-03) is dissolved in a mixed solvent of an organic solvent (for example, dichloromethane, tetrahydrofuran, etc.) and water, and an alkali metal salt of a desired anion X ⁻ is dissolved therein. L ⁺ X ⁻ (L ⁺ represents an alkali metal cation such as lithium ion, potassium ion, sodium ion, etc.) is added and reacted, followed by liquid separation and washing with water, and from the organic layer, the following general formula (b1 -14-04) is obtained.
Next, the compound represented by the general formula (b1-14-04) is dissolved in an organic solvent (for example, dichloromethane, tetrahydrofuran and the like), ice-cooled, a base (for example, sodium hydride and the like) is added, and the desired compound is added. Alkoxyalkyl group or halide of alkoxycarbonylalkyl group (for example, general formula “Cl—C (R ⁴⁷ ) (R ⁴⁸ ) —O—R ⁴⁹ ”, “Cl—R ⁵⁰ —C (═O) —O—R) ⁵¹ ”,“ Br—R ⁵⁰ —C (═O) —O—R ⁵¹ ”, etc., wherein R ^{47 to} R ⁵¹ are the same as described above), and —OH of —R ¹⁰ ″ —OH A compound (b1-14) is obtained by substituting the hydrogen atom of the group with the alkoxyalkyl group or alkoxycarbonylalkyl group.

［式中、Ｒ^８”およびＲ^９”は前記一般式（ｂ’−１４）中のＲ^８”およびＲ^９”と同様であり；Ｒ^１０”は前記一般式（ｂ’−１４）中のアリール基であるＲ^７”から１つの水素原子を除いたアリーレン基であり；Ｂ⁻は、有機酸のアニオン部であり；Ｌ^＋は、アルカリ金属カチオンであり；Ｘ⁻は、前記（Ｂ２）成分のアニオン部である。］

Wherein, ^{R 8} "and ^{R 9"} is the same as ^{R 8} "and ^{R 9"} in general formula ^{(b'-14); R 10} " is in the general formula (b'-14) An arylene group obtained by removing one hydrogen atom from R ⁷ ″ which is an aryl group; B ⁻ is an anion part of an organic acid; L ⁺ is an alkali metal cation; and X ⁻ is the above (B2). It is an anion part of a component. ]

In addition, regarding the anion exchange of the compound (b1-14-03), the hydrogen atom of the —OH group of —R ¹⁰ ″ —OH of the compound (b1-14-03) is replaced with the alkoxyalkyl before reacting with L ⁺ X ^—. The compound (b1-14) can also be obtained by performing anion exchange after substitution with a group or an alkoxycarbonylalkyl group.

In the component (B), each of the components (B1) and (B2) may be used alone or in combination of two or more.
The total content of the component (B1) and the component (B2) in the component (B) is preferably 70% by mass or more, more preferably 80% by mass or more, and may be 100% by mass. . Especially, it is most preferable that it is 100 mass%. By being above the lower limit of the range, the resist pattern has good lithography characteristics such as depth of focus (DOF) even when an inorganic or organic antireflection film is used.
Further, the ratio of the component (B2) to the total amount of the components (B1) and (B2) in the component (B) is not particularly limited, but is preferably 10 to 95% by mass, and 40 to 90% by mass. More preferably, it is most preferably 60 to 85% by mass. By adopting such a blending ratio, the resist pattern has good lithography characteristics such as depth of focus (DOF) even when an inorganic or organic antireflection film is used.
And in the resist composition of this invention, it is preferable that the total content of (B1) component and (B2) component is 1-30 mass parts with respect to 100 mass parts of said (A) component, The amount is particularly preferably 20 parts by mass, and most preferably 7 to 18 parts by mass. By being above the lower limit of the range, the resist pattern has good lithography characteristics such as depth of focus (DOF) even when an inorganic or organic antireflection film is used. On the other hand, storage stability will become favorable by being below an upper limit.

In the component (B), the acid generator (B3) (hereinafter referred to as the component (B3)) other than the component (B1) and the component (B2) is referred to as the component (B1) as long as the effects of the present invention are not impaired. ) Component and (B2) component may be used in combination.
The component (B3) is not particularly limited as long as it is other than the component (B1) and the component (B2), and those that have been proposed as acid generators for chemically amplified resists can be used.
Examples of such acid generators include onium salt acid generators such as iodonium salts and sulfonium salts, oxime sulfonate acid generators, bisalkyl or bisarylsulfonyldiazomethanes, poly (bissulfonyl) diazomethanes, and the like. There are various known diazomethane acid generators, nitrobenzyl sulfonate acid generators, imino sulfonate acid generators, disulfone acid generators, and the like.

  As the onium salt acid generator, for example, a compound represented by the following general formula (b-1) or (b-2) can be used.

［式中、Ｒ^１”〜Ｒ^３”，Ｒ^５”〜Ｒ^６”は、それぞれ独立に、アリール基またはアルキル基を表し；式（ｂ−１）におけるＲ^１”〜Ｒ^３”のうち、いずれか２つが相互に結合して式中のイオウ原子と共に環を形成してもよく；Ｒ^４”は、直鎖状、分岐鎖状または環状のアルキル基またはフッ素化アルキル基を表し；Ｒ^１”〜Ｒ^３”のうち少なくとも１つはアリール基を表し、Ｒ^５”〜Ｒ^６”のうち少なくとも１つはアリール基を表す。］

[Wherein, R ¹ ″ to R ³ ″ and R ⁵ ″ to R ⁶ ″ each independently represents an aryl group or an alkyl group; among R ¹ ″ to R ³ ″ in formula (b-1), Any two may be bonded together to form a ring with the sulfur atom in the formula; R ⁴ ″ represents a linear, branched or cyclic alkyl group or a fluorinated alkyl group; R ¹ At least one of “˜R ³ ” represents an aryl group, and at least one of R ⁵ ”to R ⁶ ” represents an aryl group.]

In formula (b-1), R ¹ ″ to R ³ ″ each independently represents an aryl group or an alkyl group. In addition, any two of R ¹ ″ to R ³ ″ in formula (b-1) may be bonded to each other to form a ring together with the sulfur atom in the formula.
Further, at least one of R ¹ ″ to R ³ ″ represents an aryl group. Of R ¹ ″ to R ³ ″, two or more are preferably aryl groups, and most preferably all R ¹ ″ to R ³ ″ are aryl groups.
The aryl group for R ¹ ″ to R ³ ″ is not particularly limited, and is, for example, an aryl group having 6 to 20 carbon atoms, in which part or all of the hydrogen atoms are alkyl groups, alkoxy groups It may or may not be substituted with a group, a halogen atom, a hydroxyl group or the like. The aryl group is preferably an aryl group having 6 to 10 carbon atoms because it can be synthesized at a low cost. Specific examples include a phenyl group and a naphthyl group.
The alkyl group that may be substituted for the hydrogen atom of the aryl group is preferably an alkyl group having 1 to 5 carbon atoms, and is a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. Is most preferred.
As the alkoxy group that may be substituted for the hydrogen atom of the aryl group, an alkoxy group having 1 to 5 carbon atoms is preferable, and a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, Most preferred is a tert-butoxy group.
The alkoxy group that may be substituted for the hydrogen atom of the aryl group is preferably an alkoxy group having 1 to 5 carbon atoms, and most preferably a methoxy group or an ethoxy group.
The halogen atom that may be substituted for the hydrogen atom of the aryl group is preferably a fluorine atom.
The alkyl group for R 1 ^{"~R 3",} is not particularly limited, for example, linear C1-10, branched or cyclic alkyl group, and the like. It is preferable that it is C1-C5 from the point which is excellent in resolution. Specific examples include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an n-pentyl group, a cyclopentyl group, a hexyl group, a cyclohexyl group, a nonyl group, and a decanyl group. A methyl group is preferable because it is excellent in resolution and can be synthesized at low cost.
Among these, R ¹ ″ to R ³ ″ are most preferably a phenyl group or a naphthyl group, respectively.

When any two of R ¹ ″ to R ³ ″ in the formula (b-1) are bonded to each other to form a ring together with the sulfur atom in the formula, a 3 to 10 membered ring including the sulfur atom is formed. It is preferable that a 5- to 7-membered ring is formed.
When any two of R ¹ ″ to R ³ ″ in formula (b-1) are bonded to each other to form a ring together with the sulfur atom in the formula, the remaining one may be an aryl group preferable. Examples of the aryl group include the same aryl groups as those described above for R ¹ ″ to R ³ ″.

R ⁴ ″ represents a linear, branched or cyclic alkyl group or a fluorinated alkyl group.
The linear or branched alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 4 carbon atoms.
The cyclic alkyl group is a cyclic group as indicated by R ¹ ″ and preferably has 4 to 15 carbon atoms, more preferably 4 to 10 carbon atoms, and more preferably 6 carbon atoms. Most preferably, it is -10.
The fluorinated alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 4 carbon atoms. The fluorination rate of the fluorinated alkyl group (ratio of fluorine atoms in the alkyl group) is preferably 10 to 100%, more preferably 50 to 100%. Particularly, all the hydrogen atoms are substituted with fluorine atoms. A fluorinated alkyl group (perfluoroalkyl group) is preferable because the strength of the acid is increased.
R ⁴ ″ is most preferably a linear or cyclic alkyl group or a fluorinated alkyl group.

In formula (b-2), R ⁵ ″ to R ⁶ ″ each independently represents an aryl group or an alkyl group. At least one of R ⁵ ″ to R ⁶ ″ represents an aryl group. It is preferable that all of R ⁵ ″ to R ⁶ ″ are aryl groups.
As the aryl group for R ⁵ ″ to R ⁶ ″, the same as the aryl groups for R ¹ ″ to R ³ ″ can be used.
Examples of the alkyl group for R ⁵ ″ to R ⁶ ″ include the same as the alkyl group for R ¹ ″ to R ³ ″.
Among these, it is most preferable that all of R ⁵ ″ to R ⁶ ″ are phenyl groups.
"The, ^{R 4} in the formula (b-1)" ^{R 4} in the In the formula (b-2) include the same as.

Specific examples of the onium salt acid generators represented by formulas (b-1) and (b-2) include diphenyliodonium trifluoromethanesulfonate or nonafluorobutanesulfonate, bis (4-tert-butylphenyl) iodonium. Trifluoromethane sulfonate or nonafluorobutane sulfonate, triphenylsulfonium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate, tri (4-methylphenyl) sulfonium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its Nonafluorobutanesulfonate, dimethyl (4-hydroxynaphthyl) sulfonium trifluoromethanesulfonate, its heptaful Lopropanesulfonate or its nonafluorobutanesulfonate, trifluoromethanesulfonate of monophenyldimethylsulfonium, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate; trifluoromethanesulfonate of diphenylmonomethylsulfonium, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate (4-methylphenyl) diphenylsulfonium trifluoromethanesulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate, (4-methoxyphenyl) diphenylsulfonium trifluoromethanesulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate , Trifluoromethanesulfonate of tri (4-tert-butyl) phenylsulfonium, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate, trifluoromethanesulfonate of diphenyl (1- (4-methoxy) naphthyl) sulfonium, its heptafluoropropane Sulfonate or its nonafluorobutane sulfonate, di (1-naphthyl) phenyl sulphonium trifluoromethane sulphonate, its heptafluoropropane sulphonate or its nonafluorobutane sulphonate; 1-phenyltetrahydrothiophenium trifluoromethane sulphonate, its heptafluoropropane sulphonate Or nonafluorobutanesulfonate thereof; 1- (4-methylphenyl) ) Tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropane sulfonate 1- (4-methoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate; 1- (4-ethoxynaphthalene-1- Yl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropanesulfonate or its nonaflu 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate; 1-phenyltetrahydrothiopyranium trifluoromethanesulfonate , Its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1- (4-hydroxyphenyl) tetrahydrothiopyranium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1- (3,5-dimethyl -4-Hydroxyphenyl) tetrahydrothiopyranium trifluoromethanesulfonate, its heptafluoropropanes Honeto or nonafluorobutanesulfonate; 1- (4-methylphenyl) trifluoromethanesulfonate tetrahydrothiophenium Pila chloride, heptafluoropropane sulfonate or its nonafluorobutane sulfonate, and the like.
In addition, onium salts in which the anion portion of these onium salts is replaced with methanesulfonate, n-propanesulfonate, n-butanesulfonate, or n-octanesulfonate can also be used.

  In addition, in the general formula (b-1) or (b-2), an onium salt-based acid generator in which the anion moiety is replaced with the anion moiety represented by the general formula (b-3) or (b-4). Can also be used (the cation moiety is the same as (b-1) or (b-2)).

  Moreover, the sulfonium salt which has a cation part represented by the following general formula (b-5) or (b-6) can also be used as an onium salt type | system | group acid generator.

［式中、Ｒ^５４〜Ｒ^５９はそれぞれ独立してアルキル基、アセチル基、アルコキシ基、カルボキシ基、水酸基またはヒドロキシアルキル基であり；ｎ_４〜ｎ_８はそれぞれ独立して０〜３の整数であり、ｎ_９は０〜２の整数である。］

[Wherein, R ^{54 to} R ⁵⁹ are each independently an alkyl group, acetyl group, alkoxy group, carboxy group, hydroxyl group or hydroxyalkyl group; n _{4 to} n ₈ are each independently an integer of 0 to 3; Yes, n ₉ is an integer of 0-2. ]

In R ⁵⁴ to R ^59, the alkyl group is preferably an alkyl group of 1 to 5 carbon atoms, more preferably an linear or branched alkyl group, a methyl group, an ethyl group, a propyl group, an isopropyl group, Particularly preferred is an n-butyl group or a tert-butyl group.
The alkoxy group is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a linear or branched alkoxy group, and particularly preferably a methoxy group or an ethoxy group.
The hydroxyalkyl group is preferably a group in which one or more hydrogen atoms in the alkyl group are substituted with a hydroxy group, and examples thereof include a hydroxymethyl group, a hydroxyethyl group, and a hydroxypropyl group.
When the symbols n _{4 to} n ₉ attached to R ^{54 to} R ⁵⁹ are integers of 2 or more, the plurality of R ^{54 to} R ⁵⁹ may be the same or different.
n ₄ is preferably 0 to 2, more preferably 0 or 1, and still more preferably 0.
n ₅ and n ₆ are preferably each independently 0 or 1, and more preferably 0.
n ₇ is preferably 0 to 2, and more preferably 0 or 1.
n ₈ is preferably 0 or 1, more preferably 0.
n ₉ is preferably 0 or 1, more preferably 1.

The anion part of the sulfonium salt having a cation part represented by the formula (b-5) or (b-6) is not particularly limited, and is the same as the anion part of the onium salt acid generators proposed so far. It may be a thing. Examples of the anion moiety include fluorinated alkyl sulfonate ions such as the anion moiety (R ^{4 ″} SO ₃ ⁻ ) of the onium salt acid generator represented by the general formula (b-1) or (b-2). An anion moiety represented by the general formula (b-3) or (b-4), etc. Among them, a fluorinated alkyl sulfonate ion is preferable, and a fluorinated alkyl sulfonic acid having 1 to 4 carbon atoms. Ion is more preferable, and linear perfluoroalkylsulfonic acid ions having 1 to 4 carbon atoms are particularly preferable, and specific examples thereof include trifluoromethylsulfonic acid ions, heptafluoro-n-propylsulfonic acid ions, and nonafluoro-n. -Butyl sulfonate ion etc. are mentioned.

  In this specification, the oxime sulfonate acid generator is a compound having at least one group represented by the following general formula (B-1), and has a property of generating an acid upon irradiation with radiation. is there. Such oxime sulfonate-based acid generators are frequently used for chemically amplified resist compositions, and can be arbitrarily selected and used.

［式（Ｂ−１）中、Ｒ^３１、Ｒ^３２はそれぞれ独立に有機基を表す。］

[In formula (B-1), R ³¹ and R ³² each independently represents an organic group. ]

The organic groups of R ³¹ and R ³² are groups containing carbon atoms, and atoms other than carbon atoms (for example, hydrogen atoms, oxygen atoms, nitrogen atoms, sulfur atoms, halogen atoms (fluorine atoms, chlorine atoms, etc.), etc.) You may have.
As the organic group for R ^31, a linear, branched, or cyclic alkyl group or aryl group is preferable. These alkyl groups and aryl groups may have a substituent. There is no restriction | limiting in particular as this substituent, For example, a fluorine atom, a C1-C6 linear, branched or cyclic alkyl group etc. are mentioned. Here, “having a substituent” means that part or all of the hydrogen atoms of the alkyl group or aryl group are substituted with a substituent.
As an alkyl group, C1-C20 is preferable, C1-C10 is more preferable, C1-C8 is more preferable, C1-C6 is especially preferable, and C1-C4 is the most preferable. As the alkyl group, a partially or completely halogenated alkyl group (hereinafter sometimes referred to as a halogenated alkyl group) is particularly preferable. The partially halogenated alkyl group means an alkyl group in which a part of hydrogen atoms is substituted with a halogen atom, and the fully halogenated alkyl group means that all of the hydrogen atoms are halogen atoms. Means an alkyl group substituted with Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable. That is, the halogenated alkyl group is preferably a fluorinated alkyl group.
The aryl group preferably has 4 to 20 carbon atoms, more preferably 4 to 10 carbon atoms, and most preferably 6 to 10 carbon atoms. As the aryl group, a partially or completely halogenated aryl group is particularly preferable. The partially halogenated aryl group means an aryl group in which a part of hydrogen atoms is substituted with a halogen atom, and the fully halogenated aryl group means that all of the hydrogen atoms are halogen atoms. Means an aryl group substituted with.
R ³¹ is particularly preferably an alkyl group having 1 to 4 carbon atoms having no substituent or a fluorinated alkyl group having 1 to 4 carbon atoms.

As the organic group for R ^32, a linear, branched, or cyclic alkyl group, aryl group, or cyano group is preferable. As the alkyl group and aryl group for R ^32, the same alkyl groups and aryl groups as those described above for R ³¹ can be used.
R ³² is particularly preferably a cyano group, an alkyl group having 1 to 8 carbon atoms having no substituent, or a fluorinated alkyl group having 1 to 8 carbon atoms.

  More preferable examples of the oxime sulfonate-based acid generator include compounds represented by the following general formula (B-2) or (B-3).

［式（Ｂ−２）中、Ｒ^３３は、シアノ基、置換基を有さないアルキル基またはハロゲン化アルキル基である。Ｒ^３４はアリール基である。Ｒ^３５は置換基を有さないアルキル基またはハロゲン化アルキル基である。］

[In Formula (B-2), R ³³ represents a cyano group, an alkyl group having no substituent, or a halogenated alkyl group. R ³⁴ is an aryl group. R ³⁵ represents an alkyl group having no substituent or a halogenated alkyl group. ]

［式（Ｂ−３）中、Ｒ^３６はシアノ基、置換基を有さないアルキル基またはハロゲン化アルキル基である。Ｒ^３７は２または３価の芳香族炭化水素基である。Ｒ^３８は置換基を有さないアルキル基またはハロゲン化アルキル基である。ｐ”は２または３である。］

[In Formula (B-3), R ³⁶ represents a cyano group, an alkyl group having no substituent, or a halogenated alkyl group. R ³⁷ is a divalent or trivalent aromatic hydrocarbon group. ^R38 is an alkyl group having no substituent or a halogenated alkyl group. p ″ is 2 or 3.]

In the general formula (B-2), the alkyl group or halogenated alkyl group having no substituent of R ³³ preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and carbon atoms. Numbers 1 to 6 are most preferable.
R ³³ is preferably a halogenated alkyl group, more preferably a fluorinated alkyl group.
The fluorinated alkyl group for R ³³ is preferably such that the hydrogen atom of the alkyl group is 50% or more fluorinated, more preferably 70% or more fluorinated, and 90% or more fluorinated. Particularly preferred.

As the aryl group of R ³⁴ , one hydrogen atom is removed from an aromatic hydrocarbon ring such as a phenyl group, a biphenyl group, a fluorenyl group, a naphthyl group, an anthryl group, or a phenanthryl group. And a heteroaryl group in which a part of carbon atoms constituting the ring of these groups is substituted with a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom. Among these, a fluorenyl group is preferable.
The aryl group of R ³⁴ may have a substituent such as an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group, or an alkoxy group. The alkyl group or halogenated alkyl group in the substituent preferably has 1 to 8 carbon atoms, and more preferably 1 to 4 carbon atoms. The halogenated alkyl group is preferably a fluorinated alkyl group.

The alkyl group or halogenated alkyl group having no substituent for R ³⁵ preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 6 carbon atoms.
R ³⁵ is preferably a halogenated alkyl group, more preferably a fluorinated alkyl group.
The fluorinated alkyl group for R ³⁵ is preferably such that the hydrogen atom of the alkyl group is 50% or more fluorinated, more preferably 70% or more fluorinated, and 90% or more fluorinated. Particularly preferred is the strength of the acid generated. Most preferably, it is a fully fluorinated alkyl group in which a hydrogen atom is 100% fluorine-substituted.

In the general formula (B-3), the alkyl group or halogenated alkyl group having no substituent for R ³⁶ is the same as the alkyl group or halogenated alkyl group having no substituent for R ^33. Is mentioned.
Examples of the divalent or trivalent aromatic hydrocarbon group for R ³⁷ include groups obtained by further removing one or two hydrogen atoms from the aryl group for R ³⁴ .
Examples of the alkyl group or halogenated alkyl group having no substituent of R ³⁸ include the same alkyl groups or halogenated alkyl groups as those having no substituent of R ³⁵ .
p ″ is preferably 2.

Specific examples of the oxime sulfonate acid generator include α- (p-toluenesulfonyloxyimino) -benzyl cyanide, α- (p-chlorobenzenesulfonyloxyimino) -benzyl cyanide, α- (4-nitrobenzenesulfonyloxy). Imino) -benzylcyanide, α- (4-nitro-2-trifluoromethylbenzenesulfonyloxyimino) -benzylcyanide, α- (benzenesulfonyloxyimino) -4-chlorobenzylcyanide, α- (benzenesulfonyl) Oxyimino) -2,4-dichlorobenzyl cyanide, α- (benzenesulfonyloxyimino) -2,6-dichlorobenzyl cyanide, α- (benzenesulfonyloxyimino) -4-methoxybenzyl cyanide, α- ( 2-Chlorobenzenesulfonyloxyimino) 4-methoxybenzylcyanide, α- (benzenesulfonyloxyimino) -thien-2-ylacetonitrile, α- (4-dodecylbenzenesulfonyloxyimino) -benzylcyanide, α-[(p-toluenesulfonyloxyimino) -4-methoxyphenyl] acetonitrile, α-[(dodecylbenzenesulfonyloxyimino) -4-methoxyphenyl] acetonitrile, α- (tosyloxyimino) -4-thienyl cyanide, α- (methylsulfonyloxyimino) -1-cyclo Pentenyl acetonitrile, α- (methylsulfonyloxyimino) -1-cyclohexenylacetonitrile, α- (methylsulfonyloxyimino) -1-cycloheptenylacetonitrile, α- (methylsulfonyloxyimino) -1-cyclooctene Acetonitrile, α- (trifluoromethylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- (trifluoromethylsulfonyloxyimino) -cyclohexylacetonitrile, α- (ethylsulfonyloxyimino) -ethylacetonitrile, α- (propyl Sulfonyloxyimino) -propylacetonitrile, α- (cyclohexylsulfonyloxyimino) -cyclopentylacetonitrile, α- (cyclohexylsulfonyloxyimino) -cyclohexylacetonitrile, α- (cyclohexylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- ( Ethylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- (isopropylsulfonyloxyimino) -1-cyclope N-tenyl acetonitrile, α- (n-butylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- (ethylsulfonyloxyimino) -1-cyclohexenylacetonitrile, α- (isopropylsulfonyloxyimino) -1-cyclohexenylacetonitrile , Α- (n-butylsulfonyloxyimino) -1-cyclohexenylacetonitrile, α- (methylsulfonyloxyimino) -phenylacetonitrile, α- (methylsulfonyloxyimino) -p-methoxyphenylacetonitrile, α- (trifluoro Methylsulfonyloxyimino) -phenylacetonitrile, α- (trifluoromethylsulfonyloxyimino) -p-methoxyphenylacetonitrile, α- (ethylsulfonyloxyimino) -p- Butoxy phenylacetonitrile, alpha-(propylsulfonyl oxyimino)-p-methylphenyl acetonitrile, alpha-like (methylsulfonyloxyimino)-p-bromophenyl acetonitrile.
Further, an oxime sulfonate-based acid generator disclosed in JP-A-9-208554 (paragraphs [0012] to [0014] [chemical formula 18] to [chemical formula 19]), WO2004 / 074242A2 (pages 65 to 85). The oxime sulfonate acid generators disclosed in Examples 1 to 40) of No. 1 can also be suitably used.
Moreover, the following can be illustrated as a suitable thing.

Among diazomethane acid generators, specific examples of bisalkyl or bisarylsulfonyldiazomethanes include bis (isopropylsulfonyl) diazomethane, bis (p-toluenesulfonyl) diazomethane, bis (1,1-dimethylethylsulfonyl) diazomethane, Examples include bis (cyclohexylsulfonyl) diazomethane, bis (2,4-dimethylphenylsulfonyl) diazomethane, and the like.
Further, diazomethane acid generators disclosed in JP-A-11-035551, JP-A-11-035552, and JP-A-11-035573 can also be suitably used.
Examples of poly (bissulfonyl) diazomethanes include 1,3-bis (phenylsulfonyldiazomethylsulfonyl) propane and 1,4-bis (phenylsulfonyldiazo) disclosed in JP-A-11-322707. Methylsulfonyl) butane, 1,6-bis (phenylsulfonyldiazomethylsulfonyl) hexane, 1,10-bis (phenylsulfonyldiazomethylsulfonyl) decane, 1,2-bis (cyclohexylsulfonyldiazomethylsulfonyl) ethane, 1,3 -Bis (cyclohexylsulfonyldiazomethylsulfonyl) propane, 1,6-bis (cyclohexylsulfonyldiazomethylsulfonyl) hexane, 1,10-bis (cyclohexylsulfonyldiazomethylsulfonyl) decane, etc. Door can be.

  As the component (B3), these acid generators may be used alone or in combination of two or more. Among them, it is preferable to use an onium salt having a fluorinated alkyl sulfonate ion as an anion.

  Content of (B) component in the resist composition of this invention is 0.5-30 mass parts with respect to 100 mass parts of (A) component, Preferably it is 1-15 mass parts. By setting it within the above range, pattern formation is sufficiently performed. Moreover, since a uniform solution is obtained and storage stability becomes favorable, it is preferable.

<(D) component>
In the resist composition of the present invention, a nitrogen-containing organic compound (D) (hereinafter referred to as “component (D)”) is further blended as an optional component in order to improve the resist pattern shape, stability over time, etc. be able to.
Since a wide variety of components (D) have already been proposed, any known one may be used. Among them, aliphatic amines, particularly secondary aliphatic amines and tertiary aliphatic amines are used. preferable. An aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic groups preferably have 1 to 12 carbon atoms.
Examples of the aliphatic amine include an amine (alkyl amine or alkyl alcohol amine) or a cyclic amine in which at least one hydrogen atom of ammonia NH ₃ is substituted with an alkyl group or hydroxyalkyl group having 12 or less carbon atoms.
Specific examples of alkylamines and alkyl alcohol amines include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine; diethylamine, di-n-propylamine, di- -Dialkylamines such as n-heptylamine, di-n-octylamine, dicyclohexylamine; trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-hexylamine, tri-n-pentylamine , Tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decanylamine, tri-n-dodecylamine, etc .; diethanolamine, triethanolamine, diisopropanolamine Triisopropanolamine, di -n- octanol amines, alkyl alcohol amines tri -n- octanol amine. Among these, a trialkylamine having 5 to 10 carbon atoms is more preferable, and tri-n-pentylamine is most preferable.
Examples of the cyclic amine include heterocyclic compounds containing a nitrogen atom as a hetero atom. The heterocyclic compound may be monocyclic (aliphatic monocyclic amine) or polycyclic (aliphatic polycyclic amine).
Specific examples of the aliphatic monocyclic amine include piperidine and piperazine.
As the aliphatic polycyclic amine, those having 6 to 10 carbon atoms are preferable. Specifically, 1,5-diazabicyclo [4.3.0] -5-nonene, 1,8-diazabicyclo [5. 4.0] -7-undecene, hexamethylenetetramine, 1,4-diazabicyclo [2.2.2] octane, and the like.
These may be used alone or in combination of two or more.
(D) component is normally used in 0.01-5.0 mass parts with respect to 100 mass parts of (A) component.

<Optional component>
[(E) component]
The positive resist composition of the present invention includes, as optional components, organic carboxylic acids, phosphorus oxoacids and derivatives thereof for the purpose of preventing sensitivity deterioration, improving the resist pattern shape, retention stability over time, etc. At least one compound (E) selected from the group consisting of (hereinafter referred to as component (E)) can be contained.
As the organic carboxylic acid, for example, acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, salicylic acid and the like are suitable.
Examples of phosphorus oxo acids and derivatives thereof include phosphoric acid, phosphonic acid, phosphinic acid and the like, and among these, phosphonic acid is particularly preferable.
Examples of the oxo acid derivative of phosphorus include esters in which the hydrogen atom of the oxo acid is substituted with a hydrocarbon group, and the hydrocarbon group includes an alkyl group having 1 to 5 carbon atoms and 6 to 6 carbon atoms. 15 aryl groups and the like.
Examples of phosphoric acid derivatives include phosphoric acid esters such as di-n-butyl phosphate and diphenyl phosphate.
Examples of phosphonic acid derivatives include phosphonic acid esters such as phosphonic acid dimethyl ester, phosphonic acid-di-n-butyl ester, phenylphosphonic acid, phosphonic acid diphenyl ester, and phosphonic acid dibenzyl ester.
Examples of the phosphinic acid derivatives include phosphinic acid esters such as phenylphosphinic acid.
(E) A component may be used individually by 1 type and may use 2 or more types together.
As the component (E), an organic carboxylic acid is preferable, and salicylic acid is particularly preferable.
(E) A component is used in the ratio of 0.01-5.0 mass parts per 100 mass parts of (A) component.

  If desired, the resist composition of the present invention may further contain miscible additives such as an additional resin for improving the performance of the resist film, a surfactant for improving coatability, a dissolution inhibitor, a plasticizer. An agent, a stabilizer, a colorant, an antihalation agent, a dye, and the like can be appropriately added and contained.

[(S) component]
The resist composition of the present invention can be produced by dissolving the material in an organic solvent (hereinafter sometimes referred to as (S) component).
As the component (S), any component can be used as long as it can dissolve each component to be used to form a uniform solution. Conventionally, any one of known solvents for chemically amplified resists can be used. Two or more types can be appropriately selected and used.
For example, lactones such as γ-butyrolactone;
Ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, 2-heptanone;
Polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol;
Compounds having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, dipropylene glycol monoacetate, monomethyl ether, monoethyl ether, monopropyl of the polyhydric alcohols or the compound having an ester bond Derivatives of polyhydric alcohols such as ethers, monoalkyl ethers such as monobutyl ether or compounds having an ether bond such as monophenyl ether [in these, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME) Is preferred];
Cyclic ethers such as dioxane and esters such as methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate;
Aromatic organic solvents such as anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenetol, butyl phenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, mesitylene, etc. be able to.
These organic solvents may be used independently and may be used as 2 or more types of mixed solvents.
Among these, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), and EL are preferable.
Moreover, the mixed solvent which mixed PGMEA and the polar solvent is also preferable. The blending ratio (mass ratio) may be appropriately determined in consideration of the compatibility between PGMEA and the polar solvent, preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. It is preferable to be within the range.
More specifically, when EL is blended as a polar solvent, the mass ratio of PGMEA: EL is preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. Moreover, when mix | blending PGME as a polar solvent, the mass ratio of PGMEA: PGME becomes like this. Preferably it is 1: 9-9: 1, More preferably, it is 2: 8-8: 2, More preferably, it is 3: 7-7: 3.
In addition, as the component (S), a mixed solvent of at least one selected from PGMEA and EL and γ-butyrolactone is also preferable. In this case, the mixing ratio of the former and the latter is preferably 70:30 to 95: 5.
The amount of the component (S) used is not particularly limited, but is a concentration that can be applied to a substrate or the like, and is appropriately set according to the coating film thickness. In general, the solid content concentration of the resist composition is 2 -20% by mass, preferably 5-15% by mass.

  The resist composition of the present invention is a novel resist composition that has not been conventionally known. The resist composition of the present invention can form a resist pattern having good lithography properties such as depth of focus (DOF) regardless of whether it is on an inorganic antireflection film (inorganic BARC) or an organic antireflection film (organic BARC).

In the present invention, the components (B1) and (B2) have a cation portion having an acid-dissociable group, and the structure is not changed in the non-exposed portion. Therefore, in the non-exposed portion of the resist film, it is considered that the component (A1) exhibits a dissolution inhibiting effect on the alkaline developer. When the resist composition of the present invention is a positive resist composition, the component (B1) and the component (B2) exhibit a dissolution accelerating effect in the exposed portion, and a dissolution inhibiting effect in the non-exposed portion. It is considered that
Further, as the component (B1), triphenylsulfonium (TPS) or the like is preferably converted into a cation by using an acid generator having higher transparency with respect to the exposure wavelength band (particularly the wavelength band of ArF excimer laser) than the component (B2). It can be blended more in the resist composition than the acid generator as in the part. In particular, the component (B1) having a cation portion containing a dibenzothiophene skeleton is excellent in solubility in an organic solvent (resist solvent) used for dissolving various components of the resist. Thereby, the density of the acid generator in the resist film can be increased, and it is estimated that the acid generation efficiency is further increased.
As the component (B2), an acid generator different from the component (B1), preferably an acid generator having high sensitivity to the exposure wavelength band (particularly the wavelength band of ArF excimer laser), more preferably the general formula (b The depth of focus (DOF) regardless of whether it is on an inorganic antireflection film (inorganic BARC) or an organic antireflection film (organic BARC) by using an acid generator having a cation moiety represented by '-14) It is considered that a resist pattern having good lithography characteristics such as can be formed.
Further, the use of the resist composition of the present invention is expected to improve the exposure margin (EL margin). The EL margin is an exposure amount range in which a resist pattern can be formed with a dimension in which a deviation from a target dimension is within a predetermined range when exposure is performed with a different exposure amount, that is, a resist pattern faithful to a mask pattern is obtained. It is the range of exposure amount.
Furthermore, the resist composition of the present invention can be suitably used as a resist composition for immersion exposure in a resist pattern forming method including an immersion exposure step, and can provide good lithography characteristics. In a resist pattern forming method including a step of forming a laminate, it can be suitably used as a positive resist composition for forming an upper resist film, and it is considered that good lithography characteristics can be obtained.

≪Resist pattern formation method≫
Next, the resist pattern forming method of the second aspect of the present invention will be described.
The resist pattern forming method of the present invention includes a step of forming a resist film on a support using the resist composition of the present invention, a step of exposing the resist film, and an alkali development of the resist film to form a resist pattern. Forming.

The resist pattern forming method of the present invention can be performed, for example, as follows.
That is, first, the resist composition of the present invention is applied onto a support with a spinner or the like, and prebaked (post-apply bake (PAB)) for 40 to 120 seconds, preferably 60 to 150 ° C. under a temperature condition of 80 to 150 ° C. After 90 seconds of exposure, ArF excimer laser light is selectively exposed through a desired mask pattern using, for example, an ArF exposure apparatus, and then post-exposure baking (post-exposure baking (PEB) at a temperature of 80 to 150 ° C. ) Treatment) for 40 to 120 seconds, preferably 60 to 90 seconds. Subsequently, this is developed using an alkali developer, for example, an aqueous solution of 0.1 to 10% by mass of tetramethylammonium hydroxide (TMAH), preferably rinsed with pure water and dried. In some cases, a baking process (post-bake) may be performed after the development process. In this way, a resist pattern faithful to the mask pattern can be obtained.

The support is not particularly limited, and a conventionally known one can be used, and examples thereof include a substrate for electronic components and a substrate on which a predetermined wiring pattern is formed. More specifically, a silicon substrate, a metal substrate such as copper, chromium, iron, and aluminum, a glass substrate, and the like can be given. As a material for the wiring pattern, for example, copper, aluminum, nickel, gold or the like can be used.
Further, the support may be a substrate in which an inorganic and / or organic film is provided on the above-described substrate. An inorganic antireflection film (inorganic BARC) is an example of the inorganic film. Examples of the organic film include an organic antireflection film (organic BARC).

The wavelength used for the exposure is not particularly limited, and ArF excimer laser, KrF excimer laser, F ₂ excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-ray, soft X-ray, etc. Can be done using radiation. The resist composition is effective for KrF excimer laser, ArF excimer laser, EB or EUV, particularly ArF excimer laser. It is also effective for immersion exposure.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples.

(Synthesis Example 1) <Synthesis of Compound (b1-14-401)>
[Synthesis of Intermediate Compound (1)]

Phosphorus oxide (8.53 g), 2,6-dimethylphenol (8.81 g) and diphenyl sulfoxide (12.2 g) were added in small portions to methanesulfonic acid (60.75 g) controlled at 20 ° C. or lower. After aging for 30 minutes while controlling the temperature at 15 to 20 ° C., the temperature was raised to 40 ° C. and aging was performed for 2 hours. Then, the reaction liquid was dripped at the pure water (109.35g) cooled to 15 degrees C or less. After completion of the dropwise addition, dichloromethane (54.68 g) was added, and after stirring, the dichloromethane layer was recovered. In a separate container, hexane (386.86 g) at 20 to 25 ° C. was charged, and the dichloromethane layer was added dropwise. After completion of the dropping, the mixture was aged at 20 to 25 ° C. for 30 minutes, and then filtered to obtain the target compound (yield 70.9%).
The obtained compound was analyzed by ¹ H-NMR.
¹ H-NMR (DMSO-d6, 600 MHz): δ (ppm) = 7.61-7.72 (m, 10H, phenyl), 7.14 (S, 2H, H ^c ), 3.12 (S, 3H, H ^b ), 2.22 (s, 6H, H ^a ).
From the above results, it was confirmed that the obtained compound had the structure shown below.

[Synthesis of Intermediate Compounds (b1-14-501) to (b1-14-503)]

Compound (1) (4 g) was dissolved in dichloromethane (79.8 g). After confirmation of dissolution, potassium carbonate (6.87 g) was added, and 2-methyl-2-adamantane bromoacetate (3.42 g) was added. After reaction for 24 hours under reflux, filtration, washing with water were performed, and crystallization was performed with hexane. The obtained powder was dried under reduced pressure to obtain 3.98 g of the target compound (yield 66%).
The compound was analyzed by ¹ H-NMR. The results are shown below.
¹ H-NMR (CDCl ₃ , 600 MHz): δ (ppm) = 7.83-7.86 (m, 4H, phenyl), 7.69-7.78 (m, 6H, phenyl), 7.51 ( s, 2H, Hd), 4.46 (s, 2H, Hc), 2.39 (s, 6H, Ha), 2.33 (s, 2H, Adamantane), 2.17 (s, 2H, Adamantane) , 1.71-1.976 (m, 11H, Adamantane), 1.68 (s, 3H, Hb), 1.57-1.61 (m, 2H, Adamantane).
From the results described above, it was confirmed that the obtained compound contained a compound (b1-14-501) having the structure shown below. Furthermore, it was confirmed from the measurement results of ion chromatography that the obtained compound contains compounds (b1-14-502) and (b1-14-503) having the same NMR data of the cation moiety as described above. It was done. The ratio of these compounds was 21.4 mol% of the compound (b1-14-501), 11.4 mol% of the compound (b1-14-502), and 67.2 mol% of (b1-14-503).

[Synthesis of Compound (b1-14-401)]

25.5 g of a mixture of 21.4 mol% of the compound (b1-14-501), 11.4 mol% of the compound (b1-14-502) and 67.2 mol% of (b1-14-503) was dissolved in 200 g of pure water. Thereto were added dichloromethane (127.4 g) and potassium nonafluoro-n-butanesulfonate (16.0 g), and the mixture was stirred at room temperature for 14 hours. Thereafter, the dichloromethane layer was separated, washed with dilute hydrochloric acid, washed with ammonia, and washed with water, and the dichloromethane layer was concentrated and dried to obtain the desired product (32.9 g) as a white solid.
The obtained compound was analyzed by ¹ H-NMR and ¹⁹ F-NMR.
¹ H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 7.75-7.86 (m, 10H, ArH), 7.61 (s, 2H, ArH), 4.62 (s, 2H) _{, CH 2), 2.31 (s} , 6H, CH 3), 1.49-1.97 (m, 17H, Adamantane).
¹⁹ F-NMR (DMSO-d6, 376 MHz): δ (ppm) = − 77.8, −112.2, −118.7, −123.0.
From the above results, it was confirmed that the compound had the above structure.

(Synthesis Example 2) <Synthesis of Compound (b1-141)>
[Synthesis of Intermediate Compound (b1-51)]

  1.99 g of diphosphorus pentoxide was added to 120.2 g of methanesulfonic acid, and 5.86 g of 2,6-dimethylphenol was added to the solution. After cooling the solution to 20 ° C. or lower in a water bath, 8.01 g of dibenzothiophene oxide was slowly added, and then the water bath was removed and the reaction was performed at room temperature for 14 hours. Thereafter, a mixed solution of 180.3 g of water and 180.3 g of dichloromethane was cooled to 10 ° C. or lower, and the reaction solution was slowly added dropwise thereto while maintaining the reaction solution at 25 ° C. or lower. The reaction solution was separated and the aqueous phase was taken out. 13.54 g of potassium nonafluorobutanesulfonate was added thereto, and the mixture was stirred at room temperature for 1.5 hours, and then 314.3 g of dichloromethane was added and stirred, and the organic phase was separated and taken out. Further, the organic phase was washed with 118.2 g of pure water until neutral, and then separated to take out the organic phase. Hexane (360.6 g) was added as a poor solvent to the extracted organic phase to obtain crystals. The crystals were dried under reduced pressure at 40 ° C. to obtain 12.0 g of an intermediate compound (yield 40%).

This intermediate compound was analyzed by ¹ H-NMR.
¹ H-NMR (DMSO-d6, 600 MHz): δ (ppm) = 9.59 (brs, 1H, Hg), 8.49 (d, 2H, H ^a ), 8.25 (d, 2H, H ^{d), 7.95 (t, 2H} , H c), 7.74 (t, 2H, H b), 7.20 (s, 2H, H e), 2.14 (s, 6H, H f) .
¹⁹ F-NMR (Acetone-d6, 376 MHz): δ (ppm) = − 81.2, −114.6, −121.5, −126.0.
From the above results, it was confirmed that this intermediate compound had the structure shown below.

<Synthesis of Compound (b1-141)>

After 6.05 g of the intermediate compound (b1-51) was dissolved in 60.5 g of dehydrated tetrahydrofuran and ice-cooled, 0.48 g of sodium hydride (purity 60%) was slowly added thereto. Thereafter, 3.45 g of 2-methyl-2-adamantane bromoacetate was added. After reaction for 21 hours under reflux, the reaction solution was added dropwise to 81.8 g of pure water that had been ice-cooled in advance, and extracted three times with 108.8 g of dichloromethane. The organic layer was concentrated, the obtained solid was redissolved with 40.55 g of dichloromethane, and the organic layer was washed with dilute hydrochloric acid and water. The dichloromethane solution was added dropwise to 608.25 g of n-hexane to obtain 6.95 g of the desired product (yield: 85.7%).
The obtained compound was analyzed by NMR.
¹ H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 8.49 (d, 2H, ArH), 8.30 (d, 2H, ArH), 7.93 (t, 2H, ArH), _{7.73 (t, 2H, ArH)} , 7.30 (s, 2H, ArH), 4.52 (s, CH 2), 2.16-2.24 (br s, 8H, Ar-CH 3 + Adamantane ), 1.45-1.92 (m, 15H, Adamantane + CH ₃ ).
¹⁹ F-NMR (DMSO-d6, 376 MHz): δ (ppm) = − 77.7, −112.0, −118.6, −122.9.
From the above results, it was confirmed that the compound had the above structure.

(Reference Examples 1-2, Examples 1-3, Comparative Example 1)
Each component was mixed and dissolved with the composition and blending amount shown in Table 1 to prepare a positive resist composition solution.

Each abbreviation in Table 1 has the following meaning. Moreover, the numerical value in [] is a compounding quantity (mass part). In addition, the compounding quantity of the (B) component of Reference Examples 1-2 is an equimolar quantity. Moreover, the total compounding amount of (B) -1 and (B) -2 in Example 1 is an equimolar amount with the compounding amount of (B) -1 in Comparative Example 1. "-" In Table 1 represents that it is not blended.
(A) -1: A polymer represented by the following chemical formula (A) -1 and having Mw = 7000 and Mw / Mn = 1.8.
(B) -1: An acid generator represented by the chemical formula (b1-14-401).
(B) -2: An acid generator represented by the chemical formula (b1-141).
(S) -1: PGMEA / PGME = 6: 4 (mass ratio)

The (A) -1 was obtained by copolymerization by a known dropping polymerization method using a monomer for deriving each structural unit. In chemical formula (A) -1, the number attached to the lower right of () indicates the proportion (mol%) of each structural unit. This composition ratio was calculated by ¹³ C-NMR. Moreover, Mw and Mw / Mn were calculated | required on the polystyrene conversion reference | standard by a gel permeation chromatography (GPC).

[Evaluation of optical properties (absorbance)]
Each of the resist compositions of Reference Examples 1 and 2 was applied onto a 1-inch quartz substrate using a spinner and baked at 110 ° C. for 60 seconds to form a resist film having a thickness of 150 nm. And the light absorbency per film thickness 1000nm of the said resist film (film thickness 150nm) in the wavelength range of 177nm -800nm was measured using the spectroscopic ellipsometry made from Woollam. When the absorbance per 1000 nm of film thickness at such a wavelength of 193 nm was determined, the absorbance when the acid generator represented by the chemical formula (b1-14-401) of Reference Example 1 was used was 1.233. When the acid generator represented by the chemical formula (b1-141) was used, the absorbance was 0.767.

<Evaluation of lithography properties>
A resist pattern was formed using the obtained positive resist composition solution, and the following lithography characteristics were evaluated.

[Sensitivity / Resolution]
An organic antireflection film composition “ARC29” (trade name, manufactured by Brewer Science Co., Ltd.) is applied onto an 8-inch silicon wafer using a spinner, and baked on a hot plate at 205 ° C. for 60 seconds to be dried. Thereby, an organic antireflection film having a film thickness of 75 nm was formed. Then, the positive resist composition solution obtained above is applied onto the antireflection film using a spinner, and prebaked (PAB) is performed on a hot plate at 110 ° C. for 60 seconds, By drying, a resist film having a thickness of 120 nm was formed.
Next, ArF immersion exposure apparatus NSR-S609B (manufactured by Nikon Corporation; NA (numerical aperture) = 1.07, illumination condition = X-pole. (0.78 / 0.97), polarization condition = w / P) , ArF excimer laser (193 nm) was selectively irradiated through a mask pattern (6% halftone). Then, a post-exposure heating (PEB) treatment was performed at 110 ° C. for 60 seconds, and a 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution “NMD-3” (Tokyo Ohka Kogyo Co., Ltd.) at 23 ° C. The film was developed for 40 seconds, rinsed with pure water for 40 seconds, and then shaken and dried to form a line-and-space (1: 1) resist pattern (L / S pattern).
As a result, an L / S pattern having a line width of 65 nm and a pitch of 130 nm was formed.
Moreover, the optimal exposure amount (sensitivity: Eop, mJ / cm ² ) at this time was determined. The results are shown in Table 2.

[Evaluation of depth of focus (DOF)]
In the Eop, the focal point is appropriately shifted up and down, and the L / S pattern can be formed within the range of the dimensional change rate of the target dimension of 65 nm ± 10% (that is, 58.5 to 71.5 nm) (DOF, Unit: nm). The results are shown in Table 2.

In the resist patterns of Examples 1 to 3 according to the present invention, an improvement in DOF was confirmed as compared with that of Comparative Example 1.
From the above result, it has confirmed that the resist composition of Examples 1-3 which concerns on this invention was able to acquire a favorable lithography characteristic.

Claims (11)

A resist composition containing a base material component (A) whose solubility in an alkaline developer is changed by the action of an acid, and an acid generator component (B) that generates an acid upon exposure,
The acid generator component (B) includes two different acid generators (B1) and (B2) having an acid dissociable group containing an aliphatic cyclic group in the cation part,
The said acid generator (B2) has a cation part represented by the following general formula (b'-14), The resist composition characterized by the above-mentioned.

[Wherein, R ⁷ ″ to R ⁹ ″ each independently represents an aryl group or an alkyl group; any two of R ⁷ ″ to R ⁹ ″ are bonded to each other together with a sulfur atom in the formula A ring may be formed (excluding the dibenzothiophene skeleton); at least one of R ⁷ ″ to R ⁹ ″ represents a part or all of hydrogen atoms represented by (b′-14-2). R ⁵⁰ is a linear or branched alkylene group, and R ⁵¹ is an acetal-type acid dissociable group or aliphatic cyclic group containing an aliphatic cyclic group. a tertiary alkyl ester-type acid dissociable group containing a. ] A resist composition containing a base material component (A) whose solubility in an alkaline developer is changed by the action of an acid, and an acid generator component (B) that generates an acid upon exposure,
The acid generator component (B) includes two different acid generators (B1) and (B2) having an acid dissociable group in the cation portion,
The acid generator (B1) is, Relais resist composition having a cationic portion comprising a dibenzothiophene skeleton. The resist composition according to claim 2, wherein the acid generator (B2) has a cation moiety represented by the following general formula (b′-14).

[Wherein, R ⁷ ″ to R ⁹ ″ each independently represents an aryl group or an alkyl group; any two of R ⁷ ″ to R ⁹ ″ are bonded to each other together with a sulfur atom in the formula A ring may be formed (excluding the dibenzothiophene skeleton); at least one of R ⁷ ″ to R ⁹ ″ is a part or all of hydrogen atoms being an alkoxyalkyloxy group or an alkoxycarbonylalkyloxy group. A substituted aryl group. ] The resist composition according to any one of claims 1 to 3, wherein the acid generator (B1) has an absorbance at 193 nm of less than 80% of the absorbance at 193 nm of the acid generator (B2).   The resist composition according to any one of claims 1 to 4, wherein the acid generator (B1) and / or the acid generator (B2) has a halogenated alkyl sulfonate ion as an anion moiety.   The resist composition according to claim 1, wherein the base material component (A) is a base material component whose solubility in an alkaline developer is increased by the action of an acid.   The resist composition according to claim 6, wherein the substrate component (A) is a resin component (A1) and has a structural unit (a1) derived from an acrylate ester containing an acid dissociable, dissolution inhibiting group.   The resist composition according to claim 7, wherein the base component (A) further has a structural unit (a2) derived from an acrylate ester containing a lactone-containing cyclic group.   The resist composition according to claim 7 or 8, wherein the substrate component (A) further comprises a structural unit (a3) derived from an acrylate ester containing a polar group-containing aliphatic hydrocarbon group.   The resist composition as described in any one of Claims 1-9 containing a nitrogen-containing organic compound (D).   A step of forming a resist film on a support using the resist composition according to claim 1, a step of exposing the resist film, and an alkali development of the resist film to form a resist pattern A resist pattern forming method including a forming step.