JP2009031350A - Resist composition and resist pattern forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resist composition and a resist pattern forming method, reducing the quantity of coating liquid and improving uniformity of film thickness of a resist film in coating on a support. <P>SOLUTION: This resist composition contains a resin component A whose solubility to an alkali developing liquid is changed by action of acid and an acid generating agent component B generating acid by exposure. The resist composition further contains fluorine contained surfactant G1 having an alkylene oxide chain containing a group expressed by the general formula (G1-0). In the formula, R<SP>f</SP>is a 1-6C fluorination alkyl group, and R<SP>11</SP>is a 1-5C alkylene group or a single bond. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

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

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 radiation 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 rapidly progressed 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 that increases solubility in an alkaline developer by the action of an acid and an acid generator. When the acid is generated, the exposed portion becomes soluble in the alkaline developer.
Up to now, as the base resin for chemically amplified resist, polyhydroxystyrene (PHS), which is highly transparent to KrF excimer laser (248 nm), and a resin whose hydroxyl group is protected with an acid dissociable, dissolution inhibiting group (PHS resin) Is used.
Moreover, as a resist base resin used in ArF excimer laser lithography and the like, a resin having a structural unit derived from (meth) acrylic acid ester in its main chain (acrylic resin) because of its excellent transparency near 193 nm ) Is mainly used (for example, see Patent Document 1).

Further, in order to improve the coating property of the resist composition on the support, perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), or a derivative thereof (PFOAs or PFOSs) is used as a surfactant. However, in recent years, the demand for non-PFOA and non-PFOS has increased, and switching to non-PFOA and non-PFOS surfactants has been desired.
JP 2003-241385 A

In recent years, the miniaturization of resist patterns has further progressed, and resist materials are required to have improved resist pattern shapes and various lithography characteristics as the demand for high resolution further increases.
In order to perform fine patterning with high accuracy, it is one of important issues to make the resist film uniform in thickness.

However, in the conventional resist composition, when the resist composition is applied onto a support such as a substrate, streaks may be formed on the resist film surface. The formation of this striation has been confirmed by the present inventors to cause a non-uniform thickness of the resist film.
In addition, in order to suppress the amount of positive photoresist composition used (resist saving), a resist composition that can be uniformly coated on a support with a small amount of coating solution is desired.

 The present invention has been made in view of the above circumstances, and when applied on a support, the resist can reduce the amount of coating liquid and improve the uniformity of the thickness of the resist film. It is an object to provide a composition and a method for forming a resist pattern.

As a result of intensive studies, the present inventors have found that the above problems can be solved by using a chemically amplified resist composition containing a specific surfactant, and have completed the present invention.
That is, the first aspect of the present invention is a resist composition containing a resin 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 resist composition further comprises a fluorine-containing surfactant (G1) having an alkylene oxide chain containing a group represented by the following general formula (G1-0).

［式（Ｇ１−０）中、Ｒ^ｆは炭素原子数１〜６のフッ素化アルキル基であり、Ｒ^１１は炭素原子数１〜５のアルキレン基または単結合である。］

[In Formula (G1-0), R ^f represents a fluorinated alkyl group having 1 to 6 carbon atoms, and R ¹¹ represents an alkylene group having 1 to 5 carbon atoms or a single bond. ]

  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, a step of exposing the resist film, and an alkali development of the resist film. And a resist pattern forming method including a step of forming a resist pattern.

In the present specification and claims, the “alkyl group” includes linear, branched, and cyclic monovalent saturated hydrocarbon groups unless otherwise specified.
The “alkylene group” includes straight-chain, branched-chain, and cyclic divalent saturated hydrocarbon groups unless otherwise specified.
“Lower alkyl group” means an alkyl group having 1 to 5 carbon atoms.
The term “exposure” includes not only light irradiation but also general irradiation of radiation such as an electron beam.
The “application surface of the support” refers to a region of the support to which the resist composition is to be applied, and generally means the entire surface of the support.
“Structural unit” means a monomer unit (monomer unit) constituting a resin component (polymer, copolymer).

  According to the present invention, a resist composition and a resist that have good coatability when coated on a support, can reduce the amount of the coating solution, and can improve the uniformity of the film thickness of the resist film. A pattern forming method can be provided.

≪Resist composition≫
The resist composition of the present invention comprises a resin component (A) whose solubility in an alkaline developer is changed by the action of an acid (hereinafter referred to as (A) component), and an acid generator component (B) that generates an acid upon exposure. ) (Hereinafter referred to as component (B)) and further having a fluorine-containing surfactant (G1) having an alkylene oxide chain containing a group represented by the general formula (G1-0) (hereinafter referred to as (G1 ) Component)).
When a resist film formed using such a resist composition is selectively exposed at the time of resist pattern formation, an acid is generated from the component (B), and the acid has a solubility in the alkaline developer of the component (A). Change. As a result, while the solubility of the exposed portion of the resist film in the alkaline developer changes, the unexposed portion does not change the solubility in the alkaline developer. In the case of the negative type, the unexposed part is dissolved and removed, and a resist pattern is formed.
The resist composition of the present invention may be a negative resist composition or a positive resist composition.

<(A) component>
As the component (A), organic compounds that are usually used as base components for chemically amplified resists can be used alone or in combination of two or more.
Here, the “base material component” is an organic compound having a film forming ability, and an organic compound having a molecular weight of 500 or more is preferably used. When the molecular weight of the organic compound is 500 or more, the film-forming ability is improved and a nano-level resist pattern is easily formed.
The organic compound having a molecular weight of 500 or more is roughly classified into a low molecular weight organic compound having a molecular weight of 500 to less than 2000 (hereinafter referred to as a low molecular compound) and a high molecular weight resin having a molecular weight of 2000 or more (polymer). Is done. As the low molecular weight compound, a non-polymer is usually used. In the case of a resin (polymer), a polystyrene-reduced weight average molecular weight by GPC (gel permeation chromatography) is used as the “molecular weight”. Hereinafter, the term “resin” refers to a resin having a molecular weight of 2000 or more.
The component (A) may be a low-molecular compound whose solubility in an alkali developer is changed by the action of an acid, or may be a resin whose solubility in an alkali developer is changed by the action of an acid. It may be a mixture of

When the resist composition of the present invention is a negative resist composition, as the component (A), a base component soluble in an alkaline developer is used, and a crosslinking agent (C) is further added to the negative resist composition. Is done.
In such a negative resist composition, when an acid is generated from the component (B) by exposure, crosslinking occurs between the component (A) and the crosslinking agent by the action of the acid, and the component (A) is converted into an alkaline developer. On the other hand, it changes from soluble to insoluble. Therefore, in the formation of the resist pattern, when the resist film obtained by applying the negative resist composition on the support is selectively exposed, the exposed portion turns insoluble in the alkali developer, Since the unexposed portion remains soluble in the alkali developer and does not change, alkali development can be performed.
As the component (A) of the negative resist composition, a resin that is soluble in an alkali developer (hereinafter referred to as an alkali-soluble resin) is usually used.

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 excellent in that the swelling is small. A resist pattern can be formed, which is preferable. Note that 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, 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 less swelling can be formed.
It is preferable that the compounding quantity of a crosslinking agent 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, as the component (A), a base material component whose solubility in an alkaline developer is increased by the action of an acid is used.
Such a positive resist composition is insoluble in an alkali developer before exposure, and when an acid is generated from the component (B) by exposure at the time of forming a resist pattern, the whole of the component (A) is caused by the action of the acid. The solubility in an alkali developer increases, and the alkali-insoluble is changed to alkali-soluble. Therefore, in the formation of the resist pattern, when the resist film obtained by applying the positive resist composition on a support is selectively exposed, the exposed portion turns soluble in an alkali developer, Since the unexposed portion remains insoluble in the alkali developer and does not change, alkali development can be performed.

In the resist composition of the present invention, the component (A) is preferably a base material component 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.
The component (A) of the positive resist composition is preferably the following resin component (A1) and / or low molecular compound (A2), more preferably the resin component (A1).
Resin component (A1): a polymer compound (polymer material component) whose solubility in an alkaline developer is increased by the action of an acid.
Low molecular weight compound (A2): A low molecular weight compound whose solubility in an alkaline developer is increased by the action of an acid.

-(A1) component (A) component suitably used in the resist composition of the present invention is the resin component (A1) (hereinafter referred to as the (A1) component), wherein the (A1) component is: It has a structural unit (a0) derived from hydroxystyrene.
In addition to the structural unit (a0), the component (A1) further preferably has a structural unit (a1) derived from styrene.

[Structural unit (a0)]
The structural unit (a0) is a structural unit derived from hydroxystyrene.
In the present specification and claims, the term “hydroxystyrene” refers to hydroxystyrene, those obtained by substituting the hydrogen atom at the α-position of hydroxystyrene with another substituent such as an alkyl group, and derivatives thereof. Include concepts. Specifically, at least a benzene ring and a hydroxyl group bonded to the benzene ring are maintained. For example, the hydrogen atom bonded to the α-position of hydroxystyrene is a lower alkyl group having 1 to 5 carbon atoms. Those substituted with a substituent, those having a lower alkyl group having 1 to 5 carbon atoms bonded to a benzene ring to which a hydroxyl group of hydroxystyrene is bonded, and further having 1 to 2 to a benzene ring having a hydroxyl group bonded thereto In this case, the number of hydroxyl groups bonded (the total number of hydroxyl groups is 2 to 3 at this time) and the like are included.
The “α-position (α-position carbon atom)” is a carbon atom to which a benzene ring is bonded, unless otherwise specified.
“Structural unit derived from hydroxystyrene” means a structural unit formed by cleavage of an ethylenic double bond of hydroxystyrene.

  As a suitable thing contained in a structural unit (a0), the structural unit represented by the following general formula (a0-1) can be illustrated.

［式（ａ０−１）中、Ｒ’は水素原子または低級アルキル基であり；Ｒ^６は低級アルキル基であり；ｐは１〜３の整数であり；ｑは０〜２の整数である。］

[In formula (a0-1), R ′ represents a hydrogen atom or a lower alkyl group; R ⁶ represents a lower alkyl group; p represents an integer of 1 to 3; and q represents an integer of 0 to 2. ]

In the general formula (a0-1), the lower alkyl group for R ′ is an alkyl group having 1 to 5 carbon atoms, and specifically includes a methyl group, an ethyl group, a propyl group, an isopropyl group, and an n-butyl group. , A linear or branched alkyl group such as an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, or a neopentyl group.
R ′ is particularly preferably a hydrogen atom or a methyl group.

p is an integer of 1 to 3, preferably 1.
The bonding position of the hydroxyl group may be any of the o-position, m-position and p-position of the phenyl group. When p is 1, the p-position is preferred because it is readily available and inexpensive. When p is 2 or 3, arbitrary substitution positions can be combined.

q is an integer of 0-2. Among these, q is preferably 0 or 1, and is preferably 0 industrially.
As the lower alkyl group for R ^{6, the same as} the lower alkyl group for R ′ can be exemplified.
When q is 1, the substitution position of R ⁶ may be any of the o-position, m-position, and p-position. When q is 2, arbitrary substitution positions can be combined. The plurality of R ⁶ may be the same or different.

As the structural unit (a0), one type may be used alone, or two or more types may be used in combination.
The proportion of the structural unit (a0) in the component (A1) is preferably 50 to 90 mol%, preferably 55 to 85 mol%, based on the total of all structural units constituting the component (A1). More preferably, it is more preferably 60 to 80 mol%. Within this range, moderate alkali solubility can be obtained when the resist composition is prepared, and the balance with other structural units is good.

[Structural unit (a1)]
The structural unit (a1) is a structural unit derived from styrene. By having the structural unit (a1), the solubility in an alkali developer can be adjusted. Moreover, when it is set as a resist composition, heat resistance and dry etching resistance improve.
In the present specification and claims, “styrene” means styrene, and those obtained by substituting the hydrogen atom at the α-position of styrene with another substituent such as an alkyl group, and derivatives thereof (provided that The concept includes hydroxystyrene. Therefore, the hydrogen atom of a phenyl group shall include what was substituted by substituents, such as a C1-C5 alkyl group.
“Structural unit derived from styrene” means a structural unit formed by cleavage of an ethylenic double bond of styrene.

  As a suitable thing contained in a structural unit (a1), the structural unit represented by the following general formula (a1-1) can be illustrated.

［式（ａ１−１）中、Ｒ’は前記と同じであり；Ｒ^７は炭素数１〜５の低級アルキル基であり；ｒは０〜３の整数である。］

[In formula (a1-1), R ′ is as defined above; R ⁷ is a lower alkyl group having 1 to 5 carbon atoms; and r is an integer of 0 to 3. ]

In the general formula (a1-1), R ⁷ is the same as R ⁶ in the general formula (a0-1).
r is an integer of 0 to 3, preferably 0 or 1, and industrially particularly preferably 0.
When r is 1, the substitution position of R ⁷ may be any of the o-position, m-position and p-position of the phenyl group. When r is 2 or 3, any substitution position can be combined. The plurality of R ⁷ may be the same or different.

As the structural unit (a1), one type may be used alone, or two or more types may be used in combination.
The proportion of the structural unit (a1) in the component (A1) is preferably from 1 to 40 mol%, more preferably from 3 to 30 mol%, more preferably from 5 to 25 based on the total of all structural units constituting the component (A1). More preferred is mol%. The effect by having a structural unit (a1) as it is more than the lower limit of this range is high, and the balance with another structural unit is also favorable as it is below an upper limit.

[Structural unit (a2)]
In the present invention, the component (A1) is a structural unit containing an acid dissociable, dissolution inhibiting group, in addition to the structural unit (a0), or in addition to the structural unit (a0) and the structural unit (a1). It is preferable to have (a2).
Preferred examples of the structural unit (a2) include a structural unit (a21) represented by the following general formula (a2-1) and a structural unit (a22) represented by the following general formula (a2-2). It can be illustrated. Among these, the structural unit (a21) is preferable.

［式（ａ２−１）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^１は酸解離性溶解抑制基または酸解離性溶解抑制基を含む有機基を表す。］

[In formula (a2-1), R represents a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group; R ¹ represents an organic group containing an acid dissociable, dissolution inhibiting group or an acid dissociable, dissolution inhibiting group. ]

In the general formula (a2-1), R represents a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group.
Specific examples of the lower alkyl group for R include lower groups such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, and neopentyl. A chain or branched alkyl group is exemplified.
R is more preferably a hydrogen atom, a lower alkyl group or a fluorinated lower alkyl group, and particularly preferably a hydrogen atom or a methyl group from the viewpoint of industrial availability.

［式（ａ２−２）中、Ｒ’は水素原子または低級アルキル基であり；Ｒ^３は低級アルキル基であり；ｐは１〜３の整数であり；ｑは０〜２の整数である。Ｒ^２は酸解離性溶解抑制基または酸解離性溶解抑制基を含む有機基を表す。］

[In formula (a2-2), R ′ represents a hydrogen atom or a lower alkyl group; R ³ represents a lower alkyl group; p represents an integer of 1 to 3; and q represents an integer of 0 to 2. R ² represents an organic group containing an acid dissociable, dissolution inhibiting group or an acid dissociable, dissolution inhibiting group. ]

In the general formula (a2-2), R ′, R ³ , p and q are the same as R ′, R ⁶ , p and q in the general formula (a0-1), respectively.

In the general formulas (a2-1) and (a2-2), R ¹ and R ² each represents an organic group containing an acid dissociable, dissolution inhibiting group or an acid dissociable, dissolution inhibiting group.
Here, the “acid dissociable, dissolution inhibiting group” means a group that is dissociated by the acid when the acid is generated from the component (B) by exposure and is detached from the component (A1) after the exposure.
The acid dissociable, dissolution inhibiting group has an alkali dissolution inhibiting property that makes the entire component (A1) difficult to dissolve in an alkali developer before dissociation, and is dissociated by an acid to develop the entire alkali component (A1). It increases the solubility in the liquid.
In addition, “an organic group having an acid dissociable, dissolution inhibiting group” means an acid dissociable, dissolution inhibiting group, a group or an atom that is not dissociated by an acid (that is, an acid dissociable, dissolution inhibiting group that has not been dissociated by an acid, and has been dissociated). And (A) a group or atom which remains bonded to the component).
Hereinafter, the acid dissociable, dissolution inhibiting group and the organic group having an acid dissociable, dissolution inhibiting group may be collectively referred to as “acid dissociable, dissolution inhibiting group-containing group”.

The acid dissociable, dissolution inhibiting group is not particularly limited, and for example, a resin for resist compositions such as for KrF excimer laser and ArF excimer laser can be appropriately selected from those proposed. . Specifically, chain tertiary alkoxycarbonyl groups and chain tertiary alkoxy exemplified in the following acid dissociable, dissolution inhibiting groups (I) and (II), and acid dissociable, dissolution inhibiting group-containing group (IV) A carbonylalkyl group etc. are mentioned.
The organic group having an acid dissociable, dissolution inhibiting group is not particularly limited. For example, a resin for resist compositions such as for KrF excimer laser and ArF excimer laser is appropriately selected and used. be able to. Specific examples include organic groups having the acid dissociable, dissolution inhibiting groups listed above. Examples of organic groups having the acid dissociable, dissolution inhibiting group (II) include organic groups having the following acid dissociable, dissolution inhibiting groups. Group (III) etc. are mentioned.

Acid dissociable, dissolution inhibiting group (I)
The acid dissociable, dissolution inhibiting group (I) is a chain or cyclic tertiary alkyl group.
4-10 are preferable and, as for carbon number of a chain | strand-shaped tertiary alkyl group, 4-8 are more preferable. More specific examples of the chain-like tertiary alkyl group include a tert-butyl group and a tert-pentyl group.
The cyclic tertiary alkyl group is a monocyclic or polycyclic monovalent saturated hydrocarbon group containing a tertiary carbon atom on the ring. 4-12 are preferable and, as for carbon number of a cyclic | annular tertiary alkyl group, 5-10 are more preferable. More specifically, as the cyclic tertiary alkyl group, 1-methylcyclopentyl group, 1-ethylcyclopentyl group, 1-methylcyclohexyl group, 1-ethylcyclohexyl group, 2-methyl-2-adamantyl group, 2-ethyl -2-adamantyl group and the like.
As the acid dissociable, dissolution inhibiting group (I), a chain-like tertiary alkyl group is preferable and a tert-butyl group is particularly preferable from the viewpoint of excellent effects of the present invention (coating liquid amount, film thickness uniformity). .

Acid dissociable, dissolution inhibiting group (II)
The acid dissociable, dissolution inhibiting group (II) is a group represented by the following general formula (II).

［式（ＩＩ）中、Ｘは脂肪族環式基、芳香族環式炭化水素基または低級アルキル基を表し；Ｒ^４は水素原子または低級アルキル基を表し、もしくは、ＸおよびＲ^４がそれぞれ独立に炭素数１〜５のアルキレン基であって、Ｘの末端とＲ^４の末端とが結合していてもよく；Ｒ^５は低級アルキル基または水素原子を表す。］

[In the formula (II), X represents an aliphatic cyclic group, an aromatic cyclic hydrocarbon group or a lower alkyl group; R ⁴ represents a hydrogen atom or a lower alkyl group, or X and R ⁴ are independent of each other. And an alkylene group having 1 to 5 carbon atoms, the end of X and the end of R ⁴ may be bonded to each other; R ⁵ represents a lower alkyl group or a hydrogen atom. ]

In the general formula (II), X represents an aliphatic cyclic group, an aromatic cyclic hydrocarbon group, or a lower alkyl group.
Here, “aliphatic” in the present specification and claims is a relative concept with respect to aromatics, and is defined to mean groups, compounds, and the like that do not have aromaticity.
The “aliphatic cyclic group” means a monocyclic group or a polycyclic group having no aromaticity, and may be either saturated or unsaturated, but is usually preferably saturated.
The aliphatic cyclic group for X is a monovalent aliphatic cyclic group. The aliphatic cyclic group can be appropriately selected from, for example, those proposed in a number of conventional ArF resists. Specific examples of the aliphatic cyclic group include an aliphatic monocyclic group having 5 to 7 carbon atoms and an aliphatic polycyclic group having 10 to 16 carbon atoms. Examples of the aliphatic monocyclic group having 5 to 7 carbon atoms include groups in which one hydrogen atom has been removed from a monocycloalkane, specifically, one hydrogen atom has been removed from cyclopentane, cyclohexane and the like. Group. Examples of the aliphatic polycyclic group having 10 to 16 carbon atoms include groups in which one hydrogen atom has been removed from bicycloalkane, tricycloalkane, tetracycloalkane and the like. Specific examples include groups in which one hydrogen atom has been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among these, an adamantyl group, a norbornyl group, and a tetracyclododecanyl group are industrially preferable, and an adamantyl group is particularly preferable.
Examples of the aromatic cyclic hydrocarbon group for X include aromatic polycyclic groups having 10 to 16 carbon atoms. Specific examples include groups in which one hydrogen atom has been removed from naphthalene, anthracene, phenanthrene, pyrene, and the like. Specific examples include 1-naphthyl group, 2-naphthyl group, 1-anthryl group, 2-anthryl group, 1-phenanthryl group, 2-phenanthryl group, 3-phenanthryl group, 1-pyrenyl group, and the like. A naphthyl group is particularly preferred industrially.
As the lower alkyl group for X, the same as the lower alkyl group for R ′ in the above general formula (a0-1) can be mentioned, a methyl group or an ethyl group is more preferable, and an ethyl group is most preferable.

In the formula (II), examples of the lower alkyl group for R ⁴ include the same as the lower alkyl group for R ′ in the general formula (a0-1). Industrially, a methyl group or an ethyl group is preferable, and a methyl group is particularly preferable.
R ⁵ represents a lower alkyl group or a hydrogen atom. As the lower alkyl group for R ^{5, the same as} the lower alkyl group for R ⁴ can be exemplified. R ⁵ is preferably industrially a hydrogen atom.

Further, the in general formula (II), X and R ⁴ are each independently an alkylene group having 1 to 5 carbon atoms, and the end of the X terminal and R ⁴ may be bonded.
In this case, in the general formula (II), a cyclic group is formed by R ⁴ , X, the oxygen atom to which X is bonded, and the carbon atom to which the oxygen atom and R ⁴ are bonded. The cyclic group is preferably a 4-7 membered ring, and more preferably a 4-6 membered ring. Specific examples of the cyclic group include a tetrahydropyranyl group and a tetrahydrofuranyl group.

As the acid dissociable, dissolution inhibiting group (II), R ⁵ is a hydrogen atom, and R ⁴ is a hydrogen atom or a lower alkyl, because of excellent effects of the present invention (coating liquid amount, film thickness uniformity). It is preferably a group.
Specific examples include a group in which X is a lower alkyl group, that is, a 1-alkoxyalkyl group, such as 1-methoxyethyl group, 1-ethoxyethyl group, 1-iso-propoxyethyl group, 1-n-butoxyethyl group. Group, 1-tert-butoxyethyl group, methoxymethyl group, ethoxymethyl group, iso-propoxymethyl group, n-butoxymethyl group, tert-butoxymethyl group and the like.
Examples of the group in which X is an aliphatic cyclic group include 1-cyclohexyloxyethyl group, 1- (2-adamantyl) oxymethyl group, and 1- (1-adamantyl) represented by the following formula (II-a). ) An oxyethyl group is exemplified.
Examples of the group in which X is an aromatic cyclic hydrocarbon group include a 1- (2-naphthyl) oxyethyl group represented by the following formula (II-b).
Of these, a 1-ethoxyethyl group is particularly preferable.

.Organic groups having acid dissociable, dissolution inhibiting groups (III)
The organic group (III) having an acid dissociable, dissolution inhibiting group is a group represented by the following general formula (III). In the organic group (III) having such a structure, when an acid is generated from the component (B) by exposure, an oxygen atom bonded to Y and a carbon atom bonded to R ⁴ ′ and R ⁵ ′ are generated by the acid. broken bond ^{between, -C (R 4 ') (} R 5') -OX ' is dissociated.

［式（ＩＩＩ）中、Ｘ’は脂肪族環式基、芳香族環式炭化水素基または低級アルキル基を表し；Ｒ^４’は水素原子または低級アルキル基を表し、もしくは、Ｘ’およびＲ^４’がそれぞれ独立に炭素数１〜５のアルキレン基であって、Ｘ’の末端とＲ^４’の末端とが結合していてもよく；Ｒ^５’は低級アルキル基または水素原子を表し；Ｙは脂肪族環式基を表す。］

[In the formula (III), X ′ represents an aliphatic cyclic group, an aromatic cyclic hydrocarbon group or a lower alkyl group; R ⁴ ′ represents a hydrogen atom or a lower alkyl group, or X ′ and R ⁴ Each independently represents an alkylene group having 1 to 5 carbon atoms, and the end of X ′ may be bonded to the end of R ⁴ ′; R ⁵ ′ represents a lower alkyl group or a hydrogen atom; Y Represents an aliphatic cyclic group. ]

In the general formula (III), examples of X ′, R ⁴ ′, and R ⁵ ′ include the same as X, R ⁴ , and R ^{5 in the} general formula (II).
Examples of the aliphatic cyclic group for Y include a group obtained by removing one hydrogen atom from the aliphatic cyclic group for X above.

Acid-dissociable, dissolution inhibiting group-containing group (IV)
The acid dissociable, dissolution inhibiting group-containing group (IV) includes the above acid dissociable, dissolution inhibiting groups (I) to (II) and the organic group (III) having an acid dissociable, dissolution inhibiting group (hereinafter referred to as “acid”). It is an acid dissociable, dissolution inhibiting group-containing group that is not classified as (I) to (III)).
As the acid dissociable, dissolution inhibiting group-containing group (IV), among the conventionally known acid dissociable, dissolution inhibiting group-containing groups, any acid dissociation not classified into the above-mentioned acid dissociable, dissolution inhibiting groups (I) to (III) Soluble dissolution inhibiting group-containing groups can be used.
Specifically, for example, acid dissociable, dissolution inhibiting groups that are not classified in (I) to (III) include a chain tertiary alkoxycarbonyl group, a chain tertiary alkoxycarbonylalkyl. Groups and the like.
4-10 are preferable and, as for carbon number of a chain | strand-shaped tertiary alkoxycarbonyl group, 4-8 are more preferable. Specific examples of the chain-like tertiary alkoxycarbonyl group include a tert-butoxycarbonyl group and a tert-pentyloxycarbonyl group.
4-10 are preferable and, as for carbon number of a chain | strand-shaped tertiary alkoxycarbonylalkyl group, 4-8 are more preferable. Specific examples of the chain-like tertiary alkoxycarbonylalkyl group include a tert-butoxycarbonylmethyl group, a tert-pentyloxycarbonylmethyl group, and the like.

  As the acid dissociable, dissolution inhibiting group-containing group in the structural unit (a2), the acid dissociable, dissolution inhibiting group, etc. (I) to (III) are excellent because of the effects of the present invention (coating liquid amount, film thickness uniformity). ) And an acid dissociable, dissolution inhibiting group-containing group (IV). It is particularly preferable that the acid dissociable, dissolution inhibiting group (I) is contained.

As the structural unit (a2), one type may be used alone, or two or more types may be used in combination.
The proportion of the structural unit (a2) in the component (A1) is preferably from 5 to 70 mol%, more preferably from 5 to 65 mol%, more preferably from 5 to 60, based on the total of all structural units constituting the component (A1). More preferably, it is more preferably 5 to 55 mol%. By setting it to the lower limit value or more of the range, a good resist pattern can be obtained when the resist composition is used, and by setting the upper limit value or less, the balance with other structural units is good.

  When the structural unit (a2) includes the structural unit (a21), the proportion of the structural unit (a21) is preferably 5 to 70 mol% with respect to all the structural units constituting the component (A1). 5 to 50 mol% is more preferable, 10 to 45 mol% is further preferable, and 10 to 35 mol% is most preferable. By setting the lower limit value or more, a good resist pattern can be obtained when the resist composition is used, and by setting the upper limit value or less, the balance with other structural units is good.

  When the structural unit (a2) includes the structural unit (a22), the proportion of the structural unit (a22) is preferably 5 to 70 mol% with respect to all the structural units constituting the component (A1). 10 to 65 mol% is more preferable, 20 to 60 mol% is further preferable, and 30 to 55 mol% is most preferable. By setting the lower limit value or more, a good resist pattern can be obtained when the resist composition is used, and by setting the upper limit value or less, the balance with other structural units is good.

[Other structural units]
The component (A1) may contain a structural unit (a4) other than the structural unit (a0), the structural unit (a1), and the structural unit (a2) 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 not classified into the structural unit (a0), the structural unit (a1), and the structural unit (a2). For the ArF excimer laser, A number of hitherto known materials can be used as resist resins for KrF excimer laser (preferably for KrF excimer laser).
As the structural unit (a4), a structural unit derived from an acrylate ester containing a polar group-containing aliphatic hydrocarbon group (for example, a hydroxyl group-containing cyclic alkyl group, a hydroxyl group-containing chain alkyl group, etc.), a lactone-containing cyclic group And a structural unit derived from an acrylate ester containing a non-acid-dissociable aliphatic polycyclic group.
Here, the “lactone-containing cyclic group” refers to a cyclic group containing one ring (lactone ring) containing an —O—C (O) — structure.
The “structural unit derived from an acrylate ester” means a structural unit constituted by cleavage of an ethylenic double bond of an acrylate ester.
“Acrylic acid esters” include not only acrylic acid esters in which a hydrogen atom is bonded to the α-position carbon atom, but also those in which a substituent (an atom or group other than a hydrogen atom) is bonded to the α-position carbon atom. Include concepts. Examples of the substituent include a lower alkyl group and a halogenated lower alkyl group.
The α-position (α-position carbon atom) of a structural unit derived from an acrylate ester is a carbon atom to which a carbonyl group is bonded unless otherwise specified.
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. In view of industrial availability, a hydrogen atom or a methyl group is particularly preferable.

  In the present invention, preferred examples of the component (A1) include a polymer having the structural unit (a0) or a copolymer having the structural unit (a0) and the structural unit (a1). As the component (A1), for example, a copolymer composed of the structural unit (a0), the structural unit (a1) and the structural unit (a2) is preferable, and the structural unit (a0), the structural unit (a1) and the structural unit ( The copolymer consisting of a21) is most preferred.

  In the present invention, as the component (A1), those containing the following combinations of structural units are particularly preferable.

［式中、Ｒ’およびＲはそれぞれ上記と同じである。Ｒ^ａ〜Ｒ^ｃはそれぞれ独立して低級アルキル基である。］

[Wherein, R ′ and R are the same as defined above. R ^{a to} R ^c are each independently a lower alkyl group. ]

In the formula (A1-11), R ′ and R are the same as defined above, each independently preferably a hydrogen atom or a methyl group, and most preferably a hydrogen atom.
The lower alkyl group for R ^{a to} R ^{c is the same as} the lower alkyl group for R ′, and each of R ^{a to} R ^c is ^a linear alkyl group, and R ^{a to} R ^c have the same carbon number. Those that are alkyl groups are preferred, and those in which R ^{a to} R ^c are all linear and have the same carbon number are particularly preferred, and R ^{a to} R ^c are all methyl groups (tert-butyl). Most preferred is a group.

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) (polystyrene conversion standard by gel permeation chromatography) of the component (A1) is not particularly limited, but is preferably 2000 to 50000, more preferably 3000 to 30000, and 5000 to 20000. Most preferred. When it is smaller than the upper limit of this range, it has sufficient solubility in a resist solvent to be used as a resist. When 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 component (A), as the component (A1), one type may be used alone, or two or more types may be used in combination.

-(A2) component As a low molecular weight compound (A2) (henceforth (A2) component), molecular weight is 500 or more and less than 2000, Comprising: A hydrophilic group and an acid dissociable dissolution inhibiting group (for example, above-mentioned) (A1) A compound having an acid dissociable, dissolution inhibiting group R ¹ or R ² as exemplified in the description of the component is preferable.
Specific examples include those in which some of the hydrogen atoms of the hydroxyl group of the compound having a plurality of phenol skeletons are substituted with the acid dissociable, dissolution inhibiting group R ¹ or R ² .
As the component (A2), for example, a part of the hydrogen atom of the hydroxyl group of a low molecular weight phenol compound known as a sensitizer or heat resistance improver for non-chemically amplified g-line or i-line resists may be acid-dissociated. Those substituted with a soluble dissolution inhibiting group are preferred and can be arbitrarily used.

Examples of such low molecular weight phenol compounds include bis (4-hydroxyphenyl) methane, bis (2,3,4-trihydroxyphenyl) methane, 2- (4-hydroxyphenyl) -2- (4′-hydroxyphenyl). ) Propane, 2- (2,3,4-trihydroxyphenyl) -2- (2 ′, 3 ′, 4′-trihydroxyphenyl) propane, tris (4-hydroxyphenyl) methane, bis (4-hydroxy-) 3,5-dimethylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-3,5-dimethylphenyl) -3, 4-dihydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -3,4-dihydroxyph Phenylmethane, bis (4-hydroxy-3-methylphenyl) -3,4-dihydroxyphenylmethane, bis (3-cyclohexyl-4-hydroxy-6-methylphenyl) -4-hydroxyphenylmethane, bis (3-cyclohexyl- 4-hydroxy-6-methylphenyl) -3,4-dihydroxyphenylmethane, 1- [1- (4-hydroxyphenyl) isopropyl] -4- [1,1-bis (4-hydroxyphenyl) ethyl] benzene, Examples include 2, 3, 4 nuclei of formalin condensates of phenols such as phenol, m-cresol, p-cresol, and xylenol. Of course, it is not limited to these.
The acid dissociable, dissolution inhibiting group is not particularly limited, and examples thereof include those described above.
In the component (A), as the component (A2), one type may be used alone, or two or more types may be used in combination.

As the component (A), one type may be used alone, or two or more types may be used in combination.
In the resist composition of the present invention, the content of the component (A) may be adjusted according to the thickness of the resist film to be formed.

<(B) component>
In the resist composition of the present invention, the component (B) is not particularly limited, 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 but may form a ring with the sulfur atom bonded to each other; R 4 ^"represents a linear, branched or cyclic alkyl group or 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 substitute 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 ^{"~R 3"} is most preferably each a phenyl group or a naphthyl group.

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, 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.
"As ^{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 the 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 an anion moiety represented by the following general formula (b-3) or (b-4). Can also be used (the cation moiety is the same as (b-1) or (b-2)).

［式中、Ｘ”は、少なくとも１つの水素原子がフッ素原子で置換された炭素数２〜６のアルキレン基を表し；Ｙ”、Ｚ”は、それぞれ独立に、少なくとも１つの水素原子がフッ素原子で置換された炭素数１〜１０のアルキル基を表す。］

[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 has 2 to 6 carbon atoms, preferably 3 to 5 carbon atoms, Most preferably, it has 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 has 1 to 10 carbon atoms, Has 1 to 7 carbon atoms, more 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 ″, the strength of the acid increases as the number of hydrogen atoms substituted with fluorine atoms 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.

  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^４１〜Ｒ^４６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_１１〜ｎ_１５はそれぞれ独立して０〜３の整数であり、ｎ_１６は０〜２の整数である。］

[Wherein R ^{41 to} R ⁴⁶ are each independently an alkyl group, acetyl group, alkoxy group, carboxy group, hydroxyl group or hydroxyalkyl group; n _{11 to} n ₁₅ are each independently an integer of 0 to 3; _{There, n 16} is an integer of 0-2. ]

In R ^{41 to} R ⁴⁶ , the alkyl group is preferably an alkyl group having 1 to 5 carbon atoms, more preferably a linear or branched alkyl group, and a methyl group, an ethyl group, a propyl group, an isopropyl group, n A butyl group or a tert-butyl group is particularly preferable.
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 _{11 to} n ₁₆ attached to R ^{41 to} R ⁴⁶ are integers of 2 or more, the plurality of R ^{41 to} R ⁴⁶ may be the same or different.
n ₁₁ is preferably 0 to 2, more preferably 0 or 1, more preferably from 0.
n ₁₂ and n ₁₃ are preferably each independently 0 or 1, and more preferably 0.
n ₁₄ is preferably 0 to 2, more preferably 0 or 1.
n ₁₅ is preferably 0 or 1, more preferably 0.
n ₁₆ 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 or a fluorinated alkyl group having 1 to 4 carbon atoms which has no substituent.

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 of 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 18] to [Chemical 19]), pamphlet of International Publication No. 04/074242, An oxime sulfonate-based acid generator disclosed in Examples 1 to 40) on pages 65 to 85 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.

(B) As a component, these acid generators may be used individually by 1 type, and may be used in combination of 2 or more type.
In the present invention, it is particularly preferable to use an onium salt having a fluorinated alkyl sulfonate ion as an anion as the component (B).
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 1-10 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.

<(G1) component>
In the present invention, the component (G1) is a fluorine-based surfactant having an alkylene oxide chain containing a group represented by the following general formula (G1-0).
By containing the component (G1), the coating property when the resist composition is coated on the support is good, the amount of coating solution can be reduced, and the film thickness uniformity of the resist film can be reduced. Can be improved. Furthermore, the component (G1) is a fluorine-based surfactant of non-PFOAs / non-PFOSs that has been increasingly demanded in recent years.
Conventionally, in a resist composition, when the content of the surfactant is large, there is a problem that defects (defects) are likely to occur on the surface of the formed resist pattern. When the component (G1) in the present invention is used, the above-described effects (coating property, reduction in coating liquid amount, film thickness uniformity) can be sufficiently obtained even if the content in the resist composition is small. The occurrence of (defects) can be suppressed.

［式（Ｇ１−０）中、Ｒ^ｆは炭素原子数１〜６のフッ素化アルキル基であり、Ｒ^１１は炭素原子数１〜５のアルキレン基または単結合である。］

[In Formula (G1-0), R ^f represents a fluorinated alkyl group having 1 to 6 carbon atoms, and R ¹¹ represents an alkylene group having 1 to 5 carbon atoms or a single bond. ]

In formula (G1-0), R ^f represents a fluorinated alkyl group having 1 to 6 carbon atoms. Since the number of carbon atoms is 6 or less, it does not correspond to so-called PFOAs or PFOSs.
The fluorinated alkyl group preferably has 1 to 3 carbon atoms, and particularly preferably has 1 or 2 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%, and fluorine in which all hydrogen atoms are substituted with fluorine atoms. An alkyl group (perfluoroalkyl group) is most preferred.
R ¹¹ is an alkylene group having 1 to 5 carbon atoms or a single bond, preferably a methylene group, an ethylene group or a propylene group, and most preferably a methylene group.

  As a suitable thing of (G1) component, the compound which has a structure represented by the following general formula (G1-1) is mentioned, for example.

［式（Ｇ１−１）中、Ｒ^ｆは炭素原子数１〜６のフッ素化アルキル基であり、Ｒ^１１およびＲ^１２はそれぞれ独立して炭素原子数１〜５のアルキレン基または単結合であり、Ｒ^１３は水素原子または炭素原子数１〜５のアルキル基であり、ｎ^１は１〜５０であり、ｎ^２は０または１である。］

[In Formula (G1-1), R ^f is a fluorinated alkyl group having 1 to 6 carbon atoms, and R ¹¹ and R ¹² are each independently an alkylene group having 1 to 5 carbon atoms or a single bond. , R ¹³ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, n ¹ is 1 to 50, and n ² is 0 or 1. ]

In the formula (G1-1), R ^f and R ¹¹ are the same as R ^f and R ¹¹ in the formula (G1-0), respectively.
R ¹² is an alkylene group having 1 to 5 carbon atoms or a single bond, preferably a methylene group or ethylene group, and most preferably a methylene group.
R ¹³ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, preferably a hydrogen atom, a methyl group or an ethyl group, and most preferably a methyl group.
n ¹ is 1 to 50, since the effect of the present invention is further improved, 1-40 preferably, 3 to 35 is more preferable.
n ² is 0 or 1, and 1 is preferable.

The molecular weight of the component (G1) is preferably 200 to 7000, more preferably 1200 to 6000, and further preferably 1200 to 4500.
When the molecular weight of the component (G1) is in the above range, the coating property when the resist composition is coated on the support is improved, and the coating liquid amount can be further reduced. Further, the uniformity of the resist film thickness is further improved.

  Preferred specific examples of the component (G1) are exemplified below.

In the present invention, the component (G1) preferably includes a compound having a structure represented by the general formula (G1-1).
Among the above, the component (G1) is preferably at least one fluorine-based surfactant selected from chemical formulas (G1-1-1) to (G1-1-4), and the effect of the present invention is particularly good. Therefore, the chemical formula (G1-1-2) or the chemical formula (G1-1-3) is particularly preferable.

  Preferable specific examples of the component (G1) include, for example, polyfox series PF-636, PF-6320, PF-656, and PF-6520 (all trade names, manufactured by Omninova). Among these, in particular, PF-656 and PF-6320 have good coatability when a resist composition is coated on a support, and can reduce the amount of the coating solution and the thickness of the resist film. This is preferable because the uniformity of the film can be improved.

(G1) A component may be used individually by 1 type, or may use 2 or more types together.
The content of the component (G1) in the resist composition of the present invention is preferably 0.001 to 7 parts by mass, and 0.001 to 3 parts by mass with respect to 100 parts by mass of the component (A). More preferably, it is 0.01-1 mass part.
When the content of the component (G1) is equal to or higher than the lower limit, the coating property when the resist composition is coated on the support is improved, and the coating liquid amount can be reduced. Further, the uniformity of the resist film thickness is improved. On the other hand, when the content of the component (G1) is not more than the upper limit value, compatibility with other components is improved.

<(D) component>
In the resist composition of the present invention, a nitrogen-containing organic compound (D) (hereinafter, referred to as “component (D)”) is further included as an optional component in order to improve the resist pattern shape, the stability over time, and the like. It is preferable to do.
Since a wide variety of components (D) have already been proposed, any known one may be used. Cyclic amines, aliphatic amines, particularly secondary aliphatic amines and tertiary fats may be used. Group amines are preferred. Here, the 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 amines (alkyl amines or alkyl alcohol amines) 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 thereof include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine; diethylamine, di-n-propylamine, di-n-heptylamine, Dialkylamines such as di-n-octylamine and dicyclohexylamine; trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptyl Trialkylamines such as amine, tri-n-octylamine, tri-n-nonylamine, tri-n-decanylamine, tri-n-dodecylamine; diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di-n -Ok Noruamin, alkyl alcohol amines such as tri -n- octanol amine.
Among these, alkyl alcohol amines and trialkyl amines are preferable, and alkyl alcohol amines are most preferable. Of the alkyl alcohol amines, triethanolamine and triisopropanolamine are most preferred.
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.
In the present invention, it is particularly preferable to use an alkyl alcohol amine as the component (D).
(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 resist composition of the present invention comprises, as optional components, an organic carboxylic acid, a phosphorus oxo acid, and derivatives thereof for the purpose of preventing sensitivity deterioration and improving the resist pattern shape, retention stability over time, and the like. At least one compound (E) selected from the group (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 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.

  The resist composition of the present invention may further contain, if desired, miscible additives such as an additional resin for improving the performance of the resist film, a surfactant, a dissolution inhibitor, and a plasticizer for improving coating properties. Stabilizers, colorants, antihalation agents, dyes, 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, and 2-heptanone; many such as ethylene glycol, diethylene glycol, propylene glycol, and dipropylene glycol Monohydric alcohols; compounds having an ester bond, such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, dipropylene glycol monoacetate, monomethyl ether, monoethyl of the polyhydric alcohols or compound having the ester bond Ethers such as ether, monopropyl ether, monobutyl ether and other monoalkyl ethers and monophenyl ether Derivatives of polyhydric alcohols such as compounds having a combination [in these, propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) are preferred]; cyclic ethers such as dioxane, methyl lactate Esters such as ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate; anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether , Dibenzyl ether, phenetole, butyl phenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, mesitylene, etc. Examples include organic solvents.
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 support such as a substrate and is appropriately set according to the coating film thickness. It is used so that the partial concentration is in the range of 2 to 25% by mass, preferably 5 to 20% by mass.

  As described above, according to the resist composition of the present invention, the coatability when coated on the support is good, the amount of the coating solution can be reduced, and the film thickness of the resist film is uniform. Can be improved.

≪Resist pattern formation method≫
The resist pattern forming method of the present invention includes a step of forming a resist film on a support using the resist composition, a step of exposing the resist film, and a step of developing the resist film to form a resist pattern. Including.
The resist pattern forming method of the present invention can be performed, for example, as follows.

First, an “application process” for applying the resist composition of the present invention to the entire application surface of the support is performed.
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).

  Application of the resist composition to the support is not particularly limited, and can be performed, for example, by a well-known application method in which spin is performed after central dropping (hereinafter referred to as central dropping spin method).

After coating the resist composition on the entire coated surface of the support, for example, the support coated with the resist composition is subjected to pre-baking (post-apply bake (PAB)) of 40 to 120 at a temperature of 80 to 150 ° C. For 2 seconds, preferably 60 to 90 seconds, to form a resist film. Thereafter, the resist film is selectively exposed through a desired mask pattern.
The wavelength at the time of 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, and particularly effective for KrF excimer laser.

Then, PEB (post-exposure heating) is applied to the resist film after being selectively exposed for 40 to 120 seconds, preferably 60 to 90 seconds under a temperature condition of 80 to 150 ° C. Subsequently, this is developed using an alkaline developer comprising an alkaline aqueous solution, for example, an aqueous solution of 1 to 10% by mass of tetramethylammonium hydroxide (TMAH).
As a method of bringing the alkali developer into contact with the resist film, for example, a method of spreading the alkali developer over the entire surface of the support from a nozzle below the alkali developer droplets installed near the center of the support can be used.
And after leaving still for about 50-60 seconds and carrying out alkali image development, a resist pattern is obtained by performing the rinse process which rinses off the alkali developing solution remaining on the resist pattern surface using rinse solutions, such as a pure water.

  According to the resist pattern forming method of the present invention described above, the coating property when applying the resist composition on the support is good, and the amount of the coating liquid of the resist composition can be reduced. The uniformity of the resist film thickness can be improved.

  Examples of the present invention will be described below, but the scope of the present invention is not limited to these examples.

(Examples 1-2, Comparative Examples 1-3)
The components shown in Table 1 below were mixed and dissolved to prepare a positive resist composition having a solid content concentration of 17.79% by mass (viscosity 9 mPa · s).
The viscosity of the positive resist composition was measured under a temperature condition of 25 ° C. using a Canon-Fenske viscometer VMC-252 (product name, manufactured by Koiso Co., Ltd.).

Each abbreviation in Table 1 has the following meaning. Moreover, the numerical value in [] is a compounding quantity (mass part).
(A) -1: a copolymer represented by the following formula (A) -1, l: m: n = 65: 20: 15 (molar ratio), Mw = 10000, Mw / Mn = 2.3.
In addition, Mw and Mw / Mn were calculated | required on the polystyrene conversion reference | standard by a gel permeation chromatography (GPC). Further, in the following formula (A) -1, the symbols l, m, and n attached to the lower right of the structural unit () indicate the proportion (mol%) of each structural unit in the copolymer. The proportion of each structural unit in the copolymer (composition ratio; mol%) was calculated by carbon NMR.

(B) -1: a compound represented by the following chemical formula (B) -1.

(G1) -1: a compound represented by the following chemical formula (G1-1-3) (trade name: Polyfox PF-656, manufactured by Omninova).

(G1) -2: a compound represented by the following chemical formula (G1-1-2) (trade name: Polyfox PF-6320, manufactured by Omninova).

(G2) -1: FC-171 (trade name: Fluorad FC-171, manufactured by 3M); a fluorosilicone surfactant.
(G2) -2: XR-104 (trade name, manufactured by Dainippon Ink and Chemicals); fluorinated surfactant.

(D) -1: Triethanolamine.
(E) -1: salicylic acid.
(S) -1: PGMEA.

The positive resist composition obtained above is filtered using a membrane filter having a pore size of 0.2 μm to form a “sample”, and a resist film is formed using the sample by the method described below to obtain coating characteristics. Evaluation of (uniformity of film thickness, amount of coating solution) and evaluation of lithography properties (dimensional change with respect to exposure amount, resolution, depth of focus (DOF)) were performed.
The evaluation results are shown in Tables 2 and 3.

<Evaluation of coating properties>
[Formation of resist film]
Each sample is coated on an 8-inch silicon substrate (disc shape) using a coating apparatus SK-W80A-AV (product name, manufactured by Dainippon Screen Co., Ltd.) using a central dropping spin coating method, and has a predetermined film thickness. A coating film (about 980 nm) was formed.
Specifically, as the coating method, while rotating the silicon substrate at 1800 rpm, a sample was dropped near the center on the silicon substrate, and then rotated at 2000 rpm to spread the entire surface of the silicon substrate. Next, the silicon substrate was rotated at 1500 rpm for edge rinsing, and then rotated at 2000 rpm for shaking to form a coating film on the entire surface of the silicon substrate.
Next, the coating film was dried at a hot plate temperature of 110 ° C. for 90 seconds by proximity baking with an interval of about 0.1 mm to form a resist film.

[Evaluation of formation of striations]
The surface of the formed resist film was observed under a sodium lamp, and the formation of striation was evaluated according to the following criteria. The results are shown in Table 2.
○: No formation of striation was observed.
X: A large striation was formed.

[Evaluation of film thickness uniformity]
Regarding the formed resist film, the film thickness (Å) of the resist film at 27 positions (equal intervals) between both ends of the diameter of the 8-inch silicon substrate was determined using Nanospec 7001-0066XPW (product name, manufactured by Nanometrics Japan Co., Ltd.). ) To obtain the average value of the film thickness at 27 locations and the standard deviation (σ) of the film thickness at 27 locations. The results are shown in Table 2.
Here, “standard deviation (σ)” means that the smaller the value, the smaller the in-plane variation of the film thickness, and the higher the uniformity of the film thickness.

[Evaluation of coating liquid volume]
In the above [Resist film formation], the minimum use amount (application liquid amount) of the positive resist composition necessary for forming a coating film of the positive resist composition on the entire coated surface of the silicon substrate Asked. The amount of the coating solution was calculated from the discharge amount per second and the minimum discharge number of seconds in the coating apparatus for each of Examples and Comparative Examples in which the formation of striation was not confirmed. The results are shown in Table 3.

From the result of Table 2, Examples 1-2 which contain a fluorine-type surfactant (G1) can improve the uniformity of the film thickness of a resist film to the same extent as Comparative Example 2. Was confirmed.
From the results of Table 3, it was confirmed that Examples 1-2 according to the present invention can reduce the amount of the coating solution compared to Comparative Example 2, Comparative Example 3, and Comparative Example 3-1.

Moreover, it has confirmed that Examples 1-2 which concern on this invention can reduce the usage-amount of surfactant compared with the comparative example 2, the comparative example 3, and the comparative example 3-1. When the amount of the surfactant used is large, particulates may be deposited in forming the resist film. Therefore, it is preferable that the amount of the surfactant used is particularly small in forming a fine resist pattern.
In Comparative Example 1, streak formation was observed on the resist film surface, and it was confirmed that the film thickness of the resist film was poor.

<Evaluation of lithography properties>
[Resist pattern formation]
The positive resist compositions of Examples and Comparative Examples shown in Table 1 were respectively applied on an 8-inch silicon substrate having a surface treated with hexamethylsilazane (HMDS) using a spinner to form a coating film.
Next, the coating film was subjected to a pre-baking (PAB) process for 90 seconds by proximity baking with a hot plate temperature of 130 ° C. and an interval of about 0.1 mm to form a resist film having a thickness of 7840 mm. Filmed.
A KrF excimer laser (248 nm) was applied to the obtained resist film with a mask pattern (6%) using a KrF exposure apparatus NSR-S205C (Nikon Corporation; NA (numerical aperture) = 0.75, σ = 0.85). Selectively irradiated via halftone).
Then, the temperature of the hot plate was set to 110 ° C., the silicon substrate and the hot plate were bonded, and the post-exposure heating (PEB) treatment for 90 seconds was performed. Next, a development process for 60 seconds is performed with a 2.38 mass% TMAH aqueous solution at 23 ° C., followed by rinsing with pure water for 30 seconds, followed by spin-drying to form the following resist pattern (1). Changes, depth of focus (DOF) were evaluated.

  Resist pattern (1): Line and space (1: 1) resist pattern (hereinafter referred to as L / S pattern) having a line width of 250 nm and a pitch of 500 nm.

[Evaluation of sensitivity]
The optimum exposure amount (unit: mJ / cm ² (energy amount per unit area)) when the resist pattern (1) was formed was determined, and the value was defined as Eop.
The results are shown in Table 4.

[Evaluation of dimensional change with respect to exposure dose]
L / S patterns having a line width of 250 nm and a pitch of 500 nm as target dimensions were formed in the same manner as in [Resist pattern formation] above, with different exposure amounts.
The exposure dose, 10.2~12.2mJ ^/ cm 2, was changed every 0.2 mJ / cm ^2.
A graph (straight line) in which the horizontal axis represents the logarithm of the exposure amount and the vertical axis represents the pattern dimension (nm) with respect to the dimensional change with respect to the exposure amount of the L / S pattern formed using the positive resist composition of each example. Draw and evaluated.

[Evaluation of resolution]
In the above Eop, L / S patterns having line widths of 0.30 μm, 0.28 μm, 0.26 μm, and 0.25 μm were formed in the same manner as in the above [Resist pattern formation], and the resolution was evaluated.

[Evaluation of depth of focus (DOF)]
In the above Eop, the L / S pattern is formed by shifting the focus up and down every 0.2 μm within the range of −0.4 μm to 0.2 μm, and the size of the formed L / S pattern (the change in the dimension of the line width) The depth of focus (DOF) was evaluated.

  As a result, it was confirmed that the lithography characteristics of the positive resist compositions of Examples 1 and 2 were all at the same level as that of the positive resist composition of Comparative Example 2.

Claims (6)

A resist composition containing a resin 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,
Furthermore, the resist composition characterized by including the fluorine-type surfactant (G1) which has the alkylene oxide chain containing group represented by the following general formula (G1-0).

[In Formula (G1-0), R ^f represents a fluorinated alkyl group having 1 to 6 carbon atoms, and R ¹¹ represents an alkylene group having 1 to 5 carbon atoms or a single bond. ] The resist composition according to claim 1, wherein the fluorine-based surfactant (G1) contains a compound having a structure represented by the following general formula (G1-1).

[In Formula (G1-1), R ^f is a fluorinated alkyl group having 1 to 6 carbon atoms, and R ¹¹ and R ¹² are each independently an alkylene group having 1 to 5 carbon atoms or a single bond. , R ¹³ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, n ¹ is 1 to 50, and n ² is 0 or 1. ]   The resist composition according to claim 1, wherein the resin component (A) has a structural unit (a0) derived from hydroxystyrene.   The resist composition according to claim 3, wherein the resin component (A) further has a structural unit (a1) derived from styrene.   Furthermore, the resist composition as described in any one of Claims 1-4 containing a nitrogen-containing organic compound (D).   A step of forming a resist film on a support using the resist composition according to any one of claims 1 to 5, 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.